Datasets:

VatsaDev

/

worldbuild

like 11

[Question] [ Often in science fiction, we see aliens enslaving humans for one reason or another. This is a trope I'm attempting to repurpose, but before I go any farther, I'd like to ask: what possible motive or means could aliens actually have for enslaving humans, particularly enslaving humans and taking them to labor on other planets? I've been using historical examples of New World slavery as a model, but I'm curious as to whether or not this is realistic. Surely the contact between Europeans and the North and South American peoples would have felt "alien," as would have the great differences in technology, but I'm wondering if, given the vastness of space, it would actually be economic or even conceivable in the first place for aliens to do to humans what the European explorers and conquistadors did to Americans. It's important to me that I find a way to realistically portray such a scenario or to not portray it at all if, in fact, it's not realistic, even though it's been done many times before. I know it's a broad question, so I'll summarize: would there actually be any economic incentive and technological means for aliens to enslave humans, or would the vastness of space and drastic differences between our species dissuade them from it? [Answer] Humans are particularly suitable for a certain *kind* of labor that the alien race is not: * As methane-breathers, mining the vibranium on our oxygen-rich 2nd moon has always proved too difficult and too expensive. But look at this race of oxygen-breathers we found, good thing interstellar slave ships are cheap! * Since our race's transcendence into pure mind-in-a-floating-jar, we have relied on machines to handle all physical and manual tasks. Unfortunately, we discovered too late that our repair bots can't actually repair themselves, we need someone with fingers to do that for us. * On our planet, it was beetles that became the most intelligent species. We've always succeeded by working hard together, but it takes 400 worker beetles to move one medium-sized rock. If only we had some tall brutes with muscular arms... * Our cloud-based species can't handle the dense atmosphere of the rocky surface many miles below. If we want to extract the valuable unobtanium ore there, we need a type of worker who can. * This "sportball" we've seen on interstellar transmissions is very interesting to us, the speed and reflexes shown is amazing. What if we had our own league of humans to play sportball? * The spaceships we stol... I mean *contracted to purchase* from species 9462 have service compartments that our 15-foot tall adults can't fit into. We need to enslav... I mean *enter into an extended service agreement* with a smaller species of repair engineers. As an analogy, don't think of how humans have enslaved *each other*, think of how human *use other species*: * We ride horses and camels * We hunt with hawks and hounds * We send messages by carrier pigeon * We use mules and elephants to carry burdens * We use oxen to pull plows * We race thoroughbreds and greyhounds and ostriches and hamsters and cockroaches * We are entertained by tigers and dolphins and trained monkeys * We keep all the above and more as beloved pets If *those* species were intelligent, how might they use us? [Answer] You are misunderstanding the nature of our abductions of your people. We are not enslaving humans. That's gross! Did you really used to do that to your own species? Maybe you aren't as intelligent as our advanced scouts reported. "Mostly Harmless" is probably too generous a category for you. I will have to look into getting you reassigned. But back to your question. We don't take you from your home world for our own personal gain. We do it for the sake of the universe. Intelligent life is rare and your species is perfect for those miserable middle orbit planets which are too cold for any of the metal breathing species and too hot for the gas giant hives. You actually like planets with liquid water on them. Do you know how rare such an affinity is? No, obviously you don't or you wouldn't be wasting your time enslaving each other. You are a precious and rare creature. The universe has millions of planets which are just right for you and are wrong for all the rest of us. If we are ever to raise the average intellect of the universe above approximately zero, we need you out on all those ugly blue worlds; thinking your thoughts and dreaming your dreams. We are not enslaving you. We are helping you and ourselves in the only economics that matter... the commerce of our minds over the mindlessness void. [Answer] The question you have to ask yourself is this: **does slavery make money, in whatever economy they have?** If the answer is yes, then that's reason enough, barring ethics issues. So, ask yourself these questions: is labor cheaper than tech used to achieve whatever money making thing they're using the labor for? does the culture of the aliens serve to make humans a sort of pet and/or pleasure slave? If they are too different in type for the latter, then an economy wherein humans and other aliens are treated as curiosities for the wealthy to own, especially if the aliens believe us to be lesser--that could make sense. > > would there actually be any economic incentive and technological means for aliens to enslave humans, or would the vastness of space and drastic differences between our species dissuade them from it? > > > The answer is yes, there could be an economic incentive, and yes, this is broad. Anything from mining to farming to servant labor, or an "exotics" market (kind of like the illegal exotic pets market). As for technological means, just put an explodey collar or implant on said humans, or something that causes pain or pleasure. [Answer] ## Aliens enslaving humanity for economical reasons is utterly unrealistic Technology that makes frequent travel between stars economically feasible is almost beyond our [imagination](http://www.sciencemag.org/news/2016/05/us-lawmaker-orders-nasa-plan-trip-alpha-centauri-100th-anniversary-moon-landing). Given physics as we know it, faster than light travel is time travel and breaks causality. Slower than light methods that we can imagine now require ungodly amounts of [fuel](https://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration) to transport tiny amounts of cargo. So, it is fair to say your aliens are *very* advanced. Now let's get back to today's world. How many jobs do you think humans will be able to do better than a robot in 2025, in the real world? [Mining](https://en.wikipedia.org/wiki/Automated_mining), agriculture and [manufacturing](https://www.automationmag.com/industry-news/studies-reports/6885-how-robots-might-upend-different-professions) are already mostly automated in industrialized nations; self-driving trucks and robot surgeons are around the corner. Conclusion: it is utterly unrealistic for a civilization to have unimaginably advanced technology that enables economically feasible travel between stars but be so far behind in robotics that they cannot make robots that are more efficient than humans for labor. ## Therefore, their reasons for enslaving humanity must be purely irrational/cultural The gods command it, they enjoy enslaving sentient beings, they are enslaving us for our own good, etc. [Answer] Think of the humans as being like cattle, it's not slavery as they are not enslaving their own people (maybe they are, but the humans aren't being enslaved). In the same way we can justify dominating other life forms for our own benefit, they would be able to use that same reasoning. It's no more immoral than our farms are, really, and just like how we gain benefits from taking advantage of other species, those same reasons could easily apply to aliens taking advantage of us. Perhaps humans are more able to survive in certain environments than the aliens are, and so it's cheaper for them to get us to harvest certain resources for them, than to develop technology to allow them to do it themselves. Perhaps our problem solving abilities are more fluid than theirs, they might have a very rigid society without the ability to innovate much, and so they are taking advantage of how we think. Perhaps they don't have the alienpower to perform everything they want to do, so they use manpower instead for their simpler tasks. [Answer] There are many reasons for why enslavement makes sense but it is difficult to tell conclusively why, without knowing the nature of their reality / situation. 1.Economical * Labor + Automation has hard limits, and general Artificial Intelligence is impossible OR the Aliens think / believe this. + Said aliens have limited breeding ability, and a massive empire. Sure you can automate a lot, but you still need workers. + Humans are Super Duper special, able to work on planets that said Aliens cannot. 2.Political * It makes sense from some political viewpoint * Uplifting / The Caring Big Brother * Manifest Destiny 3.Religious * DEUS VULT! * The Korbloxian’s Burden 4.Militaristic * They need soldiers for the meat grinder, see labor requirement 5.Technological * Our genes and ecosystem give a whole new playground for them. * Humans make really great crash test dummies 6.Goldie Locks * All galactic life evolves in certain biomes, making only certain planets inhabitable. * They want our planet, and well we were already here 7.ROFLMAO * Humans are SOOO FUNNY * Humans are sexy smexy * Humans are pets. [Answer] Consider an advanced Alien civilization at the height of its powers, interstellar travel, the ability to automate any task, everyone living in a post scarcity society. At some point in the past things went wrong (through resource shortages/war/pathogen/cultural change/rise-of-the-machines or whatever). Now you have later generations struggling to survive with tech they don't fully understand, it might be easier/simpler for them (or for factions of them, rebels fighting the selfish & sufficient elite) to enslave intelligent creatures such as humans to farm/mine/fight for them than it is to try and understand the machines they use. My two cents. [Answer] If there were only a few aliens on Earch, it would be worth enslaving humans if they wanted to get things done on Earth. Let's say that traveling between stars is expensive and time-consuming, so they can send only a small population of aliens. Let's say that they are interested in extracting resources and sending them home on automated transports or they want to construct industrial facilities on Earth. Unless they have the capacity to quickly produce sophisticated robots that can do any necessary task and make good autonomous decisions, they are likely to want to enlist the local population to get things done. Now getting the local population to do things for you doesn't have to involve enslaving them, but that's probably the easiest way for a technologically-superior, non-commerce-oriented species to achieve results. Humans aren't likely to voluntarily devote large parts of their economy toward serving the aliens unless there are some really good things the aliens have (and are willing to) to trade (like technology). If a very results-oriented aliens species comes along, they are likely to take care of business in the most expedient way possible, which may just involve enslaving everyone. It might just be easier for them to do so than spend a lot of time haggling with the local populace or maybe haggling isn't done in their culture. A small group of aliens with some fearsome weapons could do so, particularly if they enlisted some humans to help them. History shows that there are plenty of people who will do some terrible things for favored treatment or to just get the chance to oppress their enemies. Results-oriented aliens probably wouldn't necessarily be interested in controlling every aspect of their enslaved humans lives. The humans could live pretty well or live terrible lives. It wouldn't matter as long as stuff got done. Chances are they would delegate the human management to their favored group of humans and only intervene when the "overseer" humans couldn't keep the rest in line or when production slowed. As you pointed out, there are strong analogies to the early Spanish conquistadors. They came from far away, had better technology (but could still be defeated because they were far outnumbered), and had a very different way of thinking than what the Native Americans were used to. They were friendly at first and then struck by surprise, catching the natives off guard. They also enlisted the help of other natives to help them conquer. Cortes, for example, enlisted the help of various groups against the Aztecs. Those groups jumped at the chance to get revenge on their hated enemies. Cortes couldn't have defeated the Aztecs otherwise: the Spaniards were too few. The results-oriented Spanish were looking for precious metals (mainly gold and silver) to ship back to Spain and enslaved many of the Native Americans to get it. The natives were the labor that was necessary to get the resources, since no other method was available. They brutally enslaved the natives, but I think that if they though they could have achieved better results with a more lenient enslavement, they would have done that. The important thing to them was wealth and they were taking any means to achieve that. So I do think that aliens with a certain way of thinking could think that it would make sense to enslave humans, if travel between stars is long expensive, but Earth has resources valuable enough to make it worth the trouble. Sending back automated cargo ships full of resources on a regular schedule would still be worth it, even if it would take centuries for those resources to reach their destination. Once the contents of pipeline started flowing at the destination, it wouldn't matter much how long it took to get there. [Answer] In Eric Flint's [Jao Empire series](https://www.goodreads.com/series/58721-jao) (first book [downloadable for free here](http://www.baen.com/categories/books-by-series-list/jao-empire-by-eric-flint-and-k-d-wentworth.html)), the Jao enslave other species because they are at war with a genocidal alien species. That enemy would destroy all life on every planet anyway, which would be kind of a waste. So it makes sense for the natives to instead live and help the Jao's war effort. What *doesn't* make sense is for the natives to be doing anything else that isn't helping the war effort. Also, the Jao are *aliens*, with alien ways of thinking. To them, there is no higher calling than being "of use", particularly in the war effort against the enemy who are trying to cleanse the galaxy. So they are really doing the aliens they conquer a big favor by giving them the chance to "be of use". If those aliens (like humans) can't understand that, they must be dumb animals or something. I'd also point out that this isn't too far gone from the historical "[White Man's burden](https://en.wikipedia.org/wiki/The_White_Man%27s_Burden)" theory, which held that white people were so superior to everyone else in the world, that it was their *duty* to those people to conquer them and force the superior culture on them. So you could go with the "Bug-eyed Alien's Burden" [Answer] It depends on what kind of technology you want to give your aliens. IF they need weeks or months (or more) of travel, to come to earth, then you must figure something the humans can do better than the rest of your alien species. That's reason enough for slavery - not always economical affordable, but a necessity. IF they can appear instantly "wormhole-like" in the outskirts of a solar system, then you can have as many reasons for slavery as you want, no matter how mundane. The short time of travel will make them financial affordable [Answer] Humans unlike every other form of life on earth are intelligent and have dexterous hands which can be put to numerous forms of labour that no other animal on earth no matter how intelligent could perform. So physically we are more versatile and useful than every form of life we know about. Mentally we can be taught to do things, AND figure out how to do things ourselves. So we'd be prime slave material as workers to enterprising aliens with a labour shortage. And that's not including our value as entertainers. [Answer] One problem with the theory that they want to steal our resources (this being an obsession on the part of film makers...) that everyone just seems to forget, or they just like to ignore the facts of our solar system: there's SO much more of any resource/rare earth metal, etc in the asteroid belt and the Kuiper belt they wouldn't need to bother enslaving anyone or taking anything from Earth, destroying things in the process when they can just grab vastly more of any such resource right from any asteroid (if they want metals of some kind) or comet (should they need lots of water). Why bother enslaving anyone - which would be very costly and time-consuming, when they can just grab whatever they want from out there (from any asteroid belt in any star system for that matter)!? And let's face it, humans are not as efficient as they like to think, quite the opposite, many are as lazy as they come. Why bother with organic beings when you can just send a robot to mine something?- A lot more efficient, doesn't require food, water, sleep, a bathroom, etc, and you give a command and it starts to do what it is you want it to, not to mention it doesn't get tired, will only need the occasional repair. They would have to be unfathomably stupid to bother with all that when they can just grab things from asteroid belts! (\*\*\*there are many star systems that have them all around the galaxy - no need to interact with any other lifeforms to get the stuff they need) [Answer] After reading all previous answers, the obvious one seems to have been left out. I imagine the driving reason for exploration is the need to increase economic growth. Species X finds planet Earth and due to their own high standards of civilization, they would never even think of enslaving an intelligent race, even if so marginally intelligent as us apes. So instead they land and start to sell trinkets for big bugs, take out mortgages, buy out major companies, put everyone over their ears in unimaginably large debts, then require you to consume whatever leftovers their economy produces and need markets for. After 2 weeks of overconsumption, the entire human race is by law employee of the interstellar X company and forced to work for life ('why, do they really only last for like 80 years?') to pay off the debt they were lured into. Slavery, no such nonsense, too much below accepted standards. Before soon, large plots of Earth are being sold to extravagant ETs as 'second houses'. Within 10 years, the human species is determined to be 'on the brink of extinction' and, for its own sake, deported massively to an underground base on Mars, where the, by then, last 20 remaining women are kept in closely guarded quarters for the Interstellar Collection of Curiosities for extensive breeding. Unfortunately, species X only included 2 males, one of which is homosexual and the other transgender and infertile. They all seem so much alike. And on to the next planet, because the economy needs to grow. [Answer] It's not really for economic gain. The alien culture is way beyond that. No, it's science: They are studying humans by putting them into different situations. For example, they study how humans behave when they are forced to mine minerals from planets; how they organize, what it takes to keep them from revolting, what strategies they employ to make their work easier, how much work they can do before they break down … sure, the mining itself could be done much better with machines, and indeed, that's how the bulk of mining is done. The human mines are not really about minerals (even though the humans in that experiment are told that), they are about studying humans. The same is true about the other places where humans are put to work, Of course they won't tell the humans that there's not really a need to steer cargo spaceships though asteroid fields, as there are both automated cargo ships and safe routes. But by sending human pilots through those fields you learn a lot about how they react to dangers and learn to avoid them. And humans are perfect for this sort of research, as they are intelligent enough to show interesting behaviour, but still stupid enough to actually believe those ludicrous scenarios they are put into. [Answer] Thucydides says nations go to war for Fear, Honor, or Profit. That's a really good lens for looking at "Why does [group] do [thing]?" and is especially apt here. Fear: Aliens enslave humanity to keep them from doing something. Maybe humanity is prophesied to destroy them, maybe humanity looks exactly like a predator on their homeworld. Regardless, humans are scary to aliens, and they need to contain or control us somehow. Might as well be slavery. Honor: Aliens enslave humanity because they feel it is right or good. Maybe they have religiously-granted dominion over all the beasts of the galaxy, maybe they are deep in the grips of th[e Green Man's Burden](https://en.wikipedia.org/wiki/The_White_Man%27s_Burden). Maybe humanity is the secret progenitor race, and aliens are only now finally able to break free of our ancestors' grasp, and show us their strength. Regardless, enslaving humanity is some sort of moral imperative. Profit: Aliens enslave humanity because they want *stuff*, and maintaining a slave race is an easy way to get it. Maybe they can't mine precious gold in our toxic atmosphere (Psychlos...), maybe human slaves are inherently a luxury good. Maybe hey just like watching the monkeys dance. Note that these aren't mutually exclusive either, and reality is rarely so clear-cut as to have one cause per effect. So mix and match! Humanity is prophesied to destroy alienity, so they are avoiding that by training us into good galactic citizens by forcing us to write enormously-profitable screwball comedies. [Answer] It all depends on how you build your world. If space travel is cheap and reasonably fast, and differences between races are not huge, enslavement could go in a scenario similar to how it went here on Earth. If, on the other hand, sending any passengers through space is very expensive, or if creating livable conditions for them is too much of a task for the aliens, enslavement would indeed lose its point. There are other topics that you would probably need to address, like antislavery feelings among the aliens (or lack of any such feelings), as well as how imported slaves can be better than robots. [Answer] There is actually a rational reason for aliens to enslave us. Meat is not better than machine at doing manual labor, especially our meat, but! Our minds are very, very effective at certain tasks, especially reflex and basic reasoning-based ones. We can outpace all AIs, so far as we've created here on Earth, in abstract reasoning, unfamiliar or new logic, and definitely intuitive thinking. But let's say that your aliens are so advanced that they don't even need our minds; their AIs and pets are smarter than us. We're still useful. An alien race that advanced could, theoretically, look at our brains and say: "Huh. Neat. Let's use that." Then, summarily genetically engineer us to be brain-producing biological machines with a sole purpose: pumping out modified human brains to be used as computational nodes or whatnot. They could even do the same thing with the neural networks of giant pacific octopuses. But let's say the aliens have it all figured out even there, and don't need our inferior neural networks, at all. We're still useful, for one thing: exploration. For any alien species that advanced, our planet would be pretty useless for anything except maybe a bit of ore, but even then, what trouble it is to extract. But a curious alien species would want to know. What's there? What's alive there? Earth is incredibly diverse in biome and biomatter. So, let's use the humans to explore. Expend minimal resources and send a single ship: have it infect the human population with some kind of retrovirus or drug or something else that brings them under our control. Make them want to explore. Educate them on how to do it right. Press the "go" button, and have the ship move on and do other important things. There's many other things our tiny brains could be useful for, and our tiny labor abilities, especially if the aliens consider it a matter of mere curiosity or simply don't care how fast it gets done so long as they don't have to waste their own time or resources. It's just foolish to focus on merely the kinds of slavery we humans have inflicted on other humans; as the world changes, what's profitable changes. Slaves for manual labor wouldn't be profitable or competitive in a post-scarcity market or one where robotics are so absurdly advanced. At any rate, that's my answer. :) [Answer] Another possible scenario: having investigated our expectations they found that this is what we want them to do to us. This is subconscious, they know for sure that there is no way to explain to us that this is what we want. And they also know that we really need it. This looks very unrealistic at first glance, but given suspicious popularity of the theme in movies, etc. makes me think that this might really be a massive subconscious desire of humans en masse. [Answer] If an alien civilization has the technology to cross the interstellar void (i.e. at least fusion), it's safe to assume the have comparable knowledge in genetics and bio-printing. Hence, they'd be better off picking up one of your fallen hair, analyzing the DNA, transferring the data at light speed (e.g. radio) back to their homeland, and manufacturing as many copies of you as they need on the spot. If they intended to maintain the human population long-term, they'd probably gather a few hundred samples, plus other parts of the biome we rely on (plants, animals, bacteria). Also, unless they can travel faster than light, they'd probably want to send to earth a robot probe that would get here much faster, being able to handle higher acceleration than organic beings (assuming the aliens are organic). [Answer] At the scale of interstellar trade or exploration, there are a few reasonable situations. If there is FTL, physics is extremely strange and not at all like what we expect. A reality check in this case is difficult. So, assuming no FTL, interstellar trips will involve tiny self-replicating hardware "seeds" that grow into a civilization. Machine intelligence, in short. Now, it may turn out that organic or hybrid intelligence is *more efficient* than machine intelligence at a myriad of tasks, or that uploading "real" brains to an emulation layer is the most efficient way to get intelligent actors in the machine. I will assume that growing intelligence in a machine may be wasteful, because real intelligence requires something as complex and rich as reality to grow, while maintaining and training existing intelligence is much easier. In this case, the aliens could enslave humans for brains. Humans consume a biosphere, which doesn't use much in the way of resources that a star-wisp civilization needs to replicate, but still generates intelligent actors. So the star-wisp civilization doubles itself a few dozen times in space, builds an invasion force, and invades the planet. There are only a few true intelligences, but a myriad of "smart bots". They descend upon Earth and harvest our brains. Maybe they start with voluntary uploads, but given how weak our defences are decide that it is more expedient to just upload almost everyone and discard the unsuitable. A breeding population is left behind to provide for further harvests. The generated intelligences are modified and trained to do tasks and have loyalty furthering the production of starwisps, solving certain categories of problem that require true intelligence. The orbital civilization bootstraps up to somewhere between K1 and K2 level, then starts launching further starwisps. It is a race, because there are other starwisp lineages that are also spreading out, and the faster you get 1 or 2 out there the more likely you get "ahead of the curve"; and if behind the curve your starwisps arrive in an already colonized solar system and your lineage dies out. Once this first wave is complete and a few dozen starwisps are sent out, the solar system fortifies against other starwisps arriving and starts a colony of the original aliens. As noted, the most efficient way to produce new intelligences is to grow them organically, so biospheres are built, artificial bodies are created, machine intelligences downloaded, and children are raised. Enslaved human minds remain useful during this period, but are reduced in importance as more and more of the intelligence requirements of the hybrid civlization are provided by their own biological creatures. Terraforming of planets is started (as they are more robust than orbital habitats). Once a few stable biospheres on planets or moons are robust and up and running, the terraforming of Earth begins. This results in the extension of the human lineage, but by this point they are no longer of economic use to the aliens. [Answer] One big advantage of slaves over robots/automation is that they are self replicating and can produce their own fuel. Imagine you have a place rich with a rare resource your race needs, but the environment there is marginal. Your people are much to enlightened/fat & lazy/... to brave the harsh environment, so you drop a seed colony of humans with rudimentary equipment to extract your resource, food to last a year, and seeds (maybe a few farm animals) and farming equipment. They either build a mining outpost or die (strong motivation). This place could be another planet in your slaver races home system (or another system if they have FTL) or just an isolated and harsh region of their home world (think Botany Bay). You come back periodically, pick up the resource(s) they've extracted and if they've done well give them their rewards (luxury goods/ recreational drugs/...) or if they've done poorly in their production of your resource(s), you punish them (public executions/withhold their recreational drugs/take the T-Bird away/...). It's not exactly slavery, but the end result are the same. With some good propaganda, you could convince them they're free and part of some noble endeavor. [Answer] **NO** The Alien race starts out as a planetary civilization, with tech similar to ours, they expand and develop better tech all round, build space elevators, orbital habitats, mine asteroids. With a population in the trillions, and vast swaths of space solar panels to produce antimatter, the aliens launch their first interstellar probe, its a small flyby mission. Populations expand further, tech booms, artificial intelligences controlling robots produce almost everything, nanotech lets most things be created atom by atom. Probes reveal intelligence on earth. To get any humans, the aliens would need to build a spaceship capable of supporting humans for many years, and making a return journey at relativistic speeds. They would have to work out what humans eat and breathe, enough biology and medicine to keep the humans alive over the many year journey, decode human language,build a huge spaceship, stop the earth being fried from the exhaust, (actual problem) and stop the human from going mad with boredom, killing themselves or damaging something important. And in just 60 years from the start of the project they have a human, after a huge civilization wide effort. Now you have to train the human to do the vitally important task while not giving them the tools to rebel or damage anything important, given that they have no understanding of your tech or culture and probably wish you dead. Even if you managed to abduct much of humanity, what use would they be? Your toddlers have a far better understanding of your world and culture, they need to be kept in a different atmosphere than you, and your advanced robots do all the work anyway. The aliens outnumber humans nearly 1,000,000 to 1 at this point so humans aren't abundant enough to be cheap labor. [Answer] If the aliens are a [parasetic race that are capable of using mammalian hosts](https://en.wikipedia.org/wiki/Goa%27uld). They will take the humans as another species of host to add to their ever-growing collection. Perhaps it even pleases this species to try out different hosts, perhaps they use other species as we use shirts and shoes - to protect from the elements and as a fashion statement. * **Alien A** - "Greetings brother, what species do you wear today?" * **Alien B** - "Why, it is a new species the research teams found in a distant galaxy. An ugly sort, but what wonderous dexterity they have. Behold, I can grip this alien writing implement with ease!" * **Alien A** - "Truly amazing. Much better than this three-fingered reptile I am inhabiting." [Answer] **Because aliens have a different perception and culture**, what to they is freedom to us is slavery and viceversa. Actually the concept of freedom varies greatly even among humans so I would not be surprised it is the same between humans and aliens. Maybe aliens' life is so evoluted that they **disregard someone doing nothing**, and **enforce Others** to do their best **to achieve their "true" potential**. I would not be surprised if aliens creates **a series of competitions** on a very wide set of skills (going from olimpic-like games to art competitions etc, even meal cooking competitions). Basically for every small aspect of our life aliens are going to force a improvement schedule based on prize/punishment system (food in Exchange for achievements, electrocution in case of failure). Also they would organize the society so that it becomes sustainable without economy, but forcing everyone achieve its true potential while producing the minimal necessary for Others (food, services all would become in 2nd place). Something like: * 7 am, harvest crops * 9 am shower * 10 am start hand-waving improvment excercises. * 22 pm hand-waving competition * 0 am go to sleep. Basically they would force ourselves **to become gladiators of our lifes**.. hei isn't the same thing happening in some TV shows (a part electrocution, well some shows have that too in reality). Maybe TV shows are organized by aliens? P\_P O\_O [Answer] Aliens may enslave or destroy us for the greater good of the planet. Actually, it is possible for the aliens to think that we are a threat to most of the other species on the Earth. Aliens may see us as an evil, which is ruling a small planet with their only strength, brain. Our population is high, we are consuming more than what we need, we are depleting a lot of resources, we are polluting the Earth and we have destroyed the balance of life on Earth. They see Earth as a moldy cheese, they enslave us (as slaves) to destroy us, with the least regard to our lives and well-being (just as we do to ourselves and other species on the planet), to get rid of that mold and to make the cheese better for others. [Answer] My personal opinion is that it makes little sense for any aliens to enslave (or exterminate) humans. ### Irrational reasons Essentially any civilization capable of getting here (using realistic spacecraft) to enslave us already has all the resources and capabilities in their own solar system that they ever hope to acquire from us. The only way you can make it worth the time and effort to come here is if their motivation isn't rational (e.g. religious reasons) or you make space travel ridiculously easy - for them (we may still be stuck with "realistic" space drives). ### Ready work force Alternatively, if your slaver aliens are biologically oriented, then they may use spacecraft designed by other slave species. If that species is dying out or revolted, the slaver species may require new "clever monkeys to tinker with their flux coils." In a realistic scenario, I would think they'd only need breeding stock and wouldn't have much interest in enslaving the whole planet. But if there was an ongoing war and they needed helping hands quickly, maybe enslaving the whole planet would be the fastest method of acquiring the necessary work force. ### Forward staging or manufacturing base If it were just civilizations going about their business, then it would not make sense to use this section. However, if there were on-going hostilities or the threat of such, then the aliens might wish to stage from a system that wasn't their home system. If they flew ships from their home system, their enemy might figure out where they originated. One advantage of enslaving the Earth would be that we have an industrial base already present. The aliens might have better industrial methods but it takes times to set that production up. Humans already have the basics of resource collection, refining, and processing down. If the aliens gave us specifications, we could build quite a bit for them. ### Violence Many SF stories explore the possibility that "peaceful" aliens evolved from herbivores. They don't have the temperament, tactical thinking, strategic thinking, and sheer knack for destruction of humans. A species looking for warriors could do worse than humans. In this case the aliens would probably need some mental gymnastics to justify the slavery. And they'd be shocked by what we do with the alien provided equipment to earn our freedom. [Answer] I think a scenario could be: * They are technologically advanced enough to be immortals (which keeps their population low). * Humans may be relatively massive compared to the aliens. * With advanced nanotechnology they could easily engineer viruses that would wipe out humanity, so we decide to bow to them. * With 7+ billion humans, we could easily move massive amounts of resources to whatever technology they have to bring resources back to home planet. * Being tiny, their robot technology might as well not be as practical as humans. * Humans know the planet very well and have infrastructure in place to gather the resources. We would be very adept at extracting it. [Answer] The aliens can't use machinery on the target planet to perform manual labor because there is some sort of electromagnetic field or w/e that makes machinery operation there impossible (not their home planet, but a third planet that they've discovered). The planet contains resources that have to be mined for warp drive, etc.. The aliens would probably use us for manual labor regardless; but on their own world, gravity is so low that their musculoskeletal systems are much weaker than ours (similar to the classical stereotype of extraterrestrial physiques), and they make rampant use of machinery for physical tasks. [Answer] We make great pets. We can open bottles of beer with our hands, teeth, and eye sockets, among other things. We can be fun to watch. We understand our environment, how to nurture it, and how to destroy it. Some of us would be amenable to slavery, or at least lives of servitude. [Answer] We think that interstellar travel will be hugely expensive, but we say this as a species who has never done it and doesn't know the ways in which it might be done. Recently scientists thought they might have created a warp bubble in an experiment, causing lasers to move faster than the speed of light. It turned out to be a mistaken calculation and not a warp bubble at all, but maybe creating warp technology is way easier than we think it is. If this species' form of interstellar travel is relatively cheap, there are any number of reasons they might have discovered it before automation. If our recent experiment had turned out to be a real warp effect, we might be developing warp technology even now, before replacing miners and slavery on our home planet. The aliens might not be very technologically advanced at all, if they stumbled onto warp technology earlier in their timeline than we did. Maybe something in their psychology makes them more able to understand warp tech than automation, or more likely to invest their resources into that area of R&D. Maybe they're just so physically awesome and up for most tasks that they never really bothered even coming up with an idea like automation, but there's some reason they can't do this particular job well (or it's just too risky) and need humans to do it. The planet might be somehow corrosive to mechanisms but not to humans. Even just sand storms that they can't adequately keep out of their gears, and they don't care if it gets into humans' "gears." Or they can heal our sandblasted eyes cheaper than repairing a machine, and those savings will eventually outweigh the cost of getting the initial stock of humans and then breeding us. Depending on how expensive interstellar travel is, humans might be cheap labor or an expensive and risky investment that the mining CEO will protect at all costs. If the alien race is at all bureaucratic, there might be some kind of subsidy or loophole where a mining company has access to interstellar travel but not automation, and this entrepreneur owns a backwater planet and this is how he decides to harvest it and make himself wealthy. If it's a long-lived species, the slavers might be content to wait centuries before the human slave experiment returns on the initial interstellar investment. Or even an alien kid borrowing his dad's interstellar car. The rest of the civilization might be enormously advanced but this person doesn't have to be. Zecharia Sitchin in his ancient astronaut theory had aliens with relatively low tech compared to most sci fi aliens. They happen to live within our own solar system, on a planet with a strange orbit that's far beyond Pluto much of the time, so they didn't need FTL or relativistic speeds to get to us at all. ]

[Question] [ A year ago, feline mammalian space pirates, a remnant of a collapsed civilization, conquered earth with their advanced technology (their civilization was Kardashev type I) and built a megacity on the continent of North America. The pirates killed 90% of human population but spared the lives of the rest. The aliens want to use humans as entertainment in circuses and zoos also as sex slaves, but the survivors are apathetic, sad and angry. They are not good as entertainment, but the cats love human physical appearance. How do I make humans happy again? [Answer] **Give them hope and a way out.** First, have very strict laws on what can and cannot be done to the slaves. Knowing that they cannot simply be tortured for the sadistic pleasure of their owners or simply killed for no reason would eliminate a great deal of anxiety. Second, have an incentive for the slaves to work hard. In ancient Rome, slaves were paid very modest wages, could own property of their own, and even buy their own freedom. Have pay rates higher for the slave positions you want filled. Having them see a way to better their position would put them in a far better mood and motivate them to excel. Third, the slaves of a more carnal nature should be given a very high status and limited period of servitude in that role. Strict laws against disfigurement and physical abuse should apply here. The exception to this should be that any slave that harms another slave would be sentenced to this role without any protections and may even be tortured to death for the pleasure of its master. Any harm to the masters done by a slave should have as its penalty, a quick execution. Laws should be in place for the confiscation of poorly treated slaves. Any owner not taking proper care of slaves will have slaves removed and placed with new owners. Lastly, all working slaves should be provided with the necessities of food, shelter and clothing with the opportunity to use their wages to buy up into better conditions. Slaves would initially live in a common area but could buy their way up to private apartments and eventually private housing. Buying better conditions rather than staying in the common area would also prolong the amount of time it would take to purchase their freedom while at the same time improving morale. [Answer] Make them think they're not slaves. A human that is a slave, and knows they're a slave, generally won't be happy, and there's not much that can be done about it. But if you can convince them they're NOT slaves, they get a bit more comfortable. Maybe you phrase it so that you're covering all of their living expenses for this job. Hell, maybe pay them a pittance so they can buy some things for their down time. Make sure they're well fed and supplied with plenty of entertainment - Including drugs, so long as they're not going to affect their performance as entertainment. Also, allow them to choose just what it is they do. Some might enjoy being in a circus. Some might want to be a prostitute. Some might relish the opportunity to be in a zoo and be "natural." There'll be times you'll have to say no, but if you're generally nice and willing to work with them about things - or at least appear to - then you can get away with a lot. Move the blame from yourself to, say, "Regulations" or "Corporate" or whatever. Then the Humans can blame that big negative, cloudy entity but not YOU. [Answer] Train them from birth to become pets and entertainments. Gather them in camps to train for about 6 years. Then put them out to sell to owners. Never give them the idea that things like 'society', 'human' or 'rights' apply to them. Train them to always happy, always smiles in present of the owners and think happy thoughts. Tell them that the good pet does not speak. Kill all the old ones. They're not trainable. After 2 generations, you have yourself a new species of absolute obedience smiling pets. [Answer] There's the Matrix model--from the movie The Matrix, in which most humans are not even aware that they are slaves... OR Employment Brokers aka Slavers, who get a percentage of their selling price, but the slaves are actually unionized and there are specific rules as to their treatment, specifically geared to what they can do/what their value is. The dream is to be bought at a high enough price that you are richly maintained, and specific things are provided for you. This gives the slaves something to strive for. Rules could be a certain number of days off per week, a certain quality of meals, education (which may drive up their value depending), supplies, bonus monies and that sort of thing. What makes it slavery is that they are owned and not allowed to leave permanently. Running away drives down a slave's value and means that they are not treated as well... They might also negotiate their own terms or they can sell themselves as long as their current master gets at least what was paid for them, so an auction might go like this: > > Lot 449 > Contortionist, love making, and calligraphy. > > Requires two days of rest, a ration of chocolates each week, three meals a day, a bottle of wine per week, theatre tickets once a month, and a gift of jewelry once a year not worth less than $300, which can be taken with them when they are sold. > > > Minimum bid starts at $12,000 > > > My numbers are arbitrary of course: this is just a system I can see working (and resume may be longer and include former prestigous owners. There will still be runaways and those who are unhappy. [Answer] Make them dependent on their status as slaves, which is essentially what humans did with domesticated animals. Thus, even if you gave them their freedom, they would re-enslave themselves in order to have a master who tells them what to do. Or, another way to put it, breed them for docility, loyalty and juvenile traits, and raise them in an environment where obeying the Master gives them a reward. Like what humans did to canis lupus this needs to be tied in with how the slaves are treated. You ever meet someone who's never left the city? You ever meet a rich kid? you ever meet someone whose parents did every little thing for them and protected them from living? a slave can have one or two jobs they do, but as long as that's all they ever have to learn, they won't know how to take care of themselves. they shouldn't even know how to prepare food for themselves. [Answer] I doubt there's anything you could do to make them "happy", even mildly oppressed people are generally going to be upset about it. But there are some things you can do to make them less likely to revolt... Bread and circuses​ are the classic route​ and you already have circuses. People who are well fed and entertained are probably going to be a little more manageable. Another approach is to further stratify your slaves into classes, so there's at least the hope of upward mobility. Note that they don't actually need to be able to significantly change their position, they just need hope, an illusion of upward mobility. "If you work extra special hard, one day you could be the head slave. Here have a cookie. Who's a good human? You are!" [Answer] Drugs. All kinds of lovely, feel-good space uppers will make these remaining humans fun again. That seems easy, at least, but maybe temporary and have all kinds of adverse effects. More difficult options include breeding, sophisticated training, psychological trickery, or even genetic manipulation. [Answer] Breed them like that, allow the ones with desirable traits to breed. Kill the others off by not allowing them to breed. You'll end up with docile pets. We did it to cows. [Answer] Not being slaves ruled by evil dictator overlords is the usual first step. The lesson of all slavery-based human cultures is that ***unhappy slaves rebel***. What stops slaves rebelling is being given the opportunity for self-fulfillment. Roman gladiators, teachers, musicians, cooks and many other professions were frequently slaves; but they were valued members of society, able to contribute and rewarded for doing so. If you can give jobs to your slaves which they enjoy doing, they will not really care that they're slaves, because they're living a fulfilling life. If the slave-owners only want entertainment in the form of circuses and sex slaves, that's less likely to give humans a fulfilling life. Some people today do find fulfillment in those jobs, but nothing like all of us. The slave-owners need to find a range of employment options for humans which *includes* these roles but also has other places available. In fiction, [the "Tripods" series](https://en.wikipedia.org/wiki/The_Tripods) describes a rebellion amongst humans who, like the OP's question, are kept alive primarily for entertainment. Conversely, the final section of [Grass](https://en.wikipedia.org/wiki/Grass_(novel)) describes a woman willingly accepting being a subordinate to a creature from another species who demonstrates that he truly cares about her. She refuses to let her pets die to save herself, which convinces this species to commit themselves to protecting humans in the same way. [Answer] Given that there is already good quality and variety of answers, I'd like to categorize them a bit and add my own thoughts. I think this may be too long for a comment, so I'll just add it as an answer (giving proper credit). In order to answer, I'd ask myself: Do the pirates have moral issues or guilt / Is there dissension among them? Do they want slaves to behave naturally? **No moral issues *and* no dissension, artificial behavior** If their only concern is the slaves' perception of themselves as "happy", then merely modifying their meaning of happiness would be sufficient and most effective, as in [*Ngoc's* answer](https://worldbuilding.stackexchange.com/a/75031/28789). A second best alternative is to create inequality. That is, make some live worse lives to make the rest value their own. This is bound to generate a lot of resistance and unhappiness. Also, given how inequality between them and the pirates will still exist, even the favored ones' happiness won't be complete. The only added benefit, compared to the previous alternative, is that it wouldn't completely erase human culture and natural behavior, at least not immediately. This is related to [*SJuan76's* answer](https://worldbuilding.stackexchange.com/a/75155/28789). Drugs may not be a good alternative as it'll shorten their utility. **Some moral issues *or* possible dissension, natural behavior** If the pirates' motivation is making them happy as their owners perceive and define happiness, then improving their situation while changing their perception of themselves is probably best, as in [*Andon's*](https://worldbuilding.stackexchange.com/a/75002/28789) and [*Robert Wm Ruedisueli's*](https://worldbuilding.stackexchange.com/a/75187/28789) answers. The Matrix model is not economically viable if such a technology hasn't been implemented already (note that I'm not saying "invented"). However, it can be, if taken metaphorically. This relates to the first part of [*Erin Thursby's* answer](https://worldbuilding.stackexchange.com/a/75015/28789). **Actual moral issues, natural environment** Setting them free is a real alternative. They could just simulate a coup d'état, change some "top" figures and everyone's happy. This is related to [*Journeyman Geek's*](https://worldbuilding.stackexchange.com/a/75083/28789) answer. *A few things I'd like to add:* Slaves have typically (note that I'm not saying always) been used for material gain (agriculture/mining and manufacture vs. services). As with most things with humanity, a convergence of economic interest and ethics advancement was needed for its abolishment. If they won't be used as a factor of production and they develop a symbiotic relation with the pirates, then they'd practically (statistically) be closer to pets than to slaves (they'd technically be slaves though). If they will be used for production though, it'd be best to have them get paid as per Andon's answer. This would eliminate the risk of losing the investment due to unforseen events (assuming private property exists, of course — and seeing they're pirates, I'd assume it does). From a narrative point of view, quick solutions would not be viable without a turn of events at hand. This may force the plot if not properly done. Given the fantasy set, perhaps a somewhat believable/natural development would be best to balance things out, though that's ultimately your decision. In summary, my answer would be "it depends". I enjoyed reading all answers and would like to note Ngoc's answer's sociolgical component about denaturalization. [Answer] **Make them afraid of the alternative** Do not kill all the other humans. Allow them to live, but just that. While your slaves will have a not-so-lavish food (meat or fish only once a week, candies only if their masters is in good mood, etc.), but enough for them to be nourished. Now, each time the meal is finished, have a few of them collect the scraps and dump them in the outside of your properties. Where the free humans are waiting, to feed themselves (surely a Type I civilization will have no trouble making all the edible plants and animals extinct). Let the slaves see how the free men are starving and fighting for the slaves'scraps, and they will think that they are privileged by being slaves. [Answer] The usual approach in America has been for slaveholders to convince themselves that the slaves are *already* happy. It's a fascinating topic, really. [Mental disorders causing slaves to run away](https://en.wikipedia.org/wiki/Drapetomania) were posited, for no other reason a slave might runaway was always obvious. [Sometimes it takes serious historical research](http://www.nytimes.com/1994/06/12/us/old-southern-documents-give-lie-to-theory-of-happy-slaves.html) to debunk the myth that slaves were generally happy (can't imagine how anyone would get that idea). It's very similar to how today we blame people without a job or health insurance for not working hard enough, being in prison for committing crimes and harming people, etc. [Answer] Set them free. Seriously. You'd have a happy, basically motivated society, that's mostly pissed at you. Your fault, but they have a lot of space to rebuild on. That'll keep them busy. A small faction of them might actually find said felines attractive (furries?) or merely suffer from stockholm syndrome. Employ them, treat them well, and you might attract a few more. Considering how human history is littered with "superior" nations defeated by small, motivated armies, leaving this planet alone would also be sensible, cause eventually you'd find random acts of sabotage and open insurrection. Students of human history would probably realise that few nations of slaveholders rested easy. [Answer] Well first, the aliens shouldn't make it out to be slavery. The easiest form of brainwashing of a slave is to make them think it's a privileged to do the work. They are concubines, not sex slaves. The humans should be convinced to compete by grooming their beauty and developing their behavior to find a good master to take care of them. This should culminate in beauty contests for the auctions when humans become of age. Furthermore, this eases ethical concerns by prospective feline masters by convincing them that they are granting the humans a great privileged. [Answer] Give them a purpose to live and fight for. Make them think that they are the human resistance movement which, against all odds, fights against the alien oppression to win back control of Earth. To make it easier to control spread the resistance settlements over a bigger areas with few (and dangerous) communication and transport paths between them. This will give keep each individual cell small enough to be manageable, also you can easily pick the humans you need for your pleasure without alerting the whole population that something's up (because you basically control all communication between cells). [Answer] Food, Shelter, Reasonable freedom Sell it to the humans this way: "You dont have to worry about working, or politics, or where to get food. Just live and from time to time entertain us" Seems like a very good bargain [Answer] **Install a brain shunt.** Admittedly this is a more high tech version of @fredsbend answer. ("Give them drugs") but direct brain alteration is a possibility. This would involve inserting a small wire through the pleasure center of the brain and delivering the right current. (Oddly, there isn't a pain center of the brain) <https://www.ncbi.nlm.nih.gov/pubmed/113691> <http://www.kurzweilai.net/electrical-stimulation-of-brain-pleasure-center-reduces-chronic-pain> This could leave you with utterly blissed out performers and really pissed off people being bred for the circus. Get it wrong and your performers won't do anything - potentially not even eating. **Moral Issues** From the felines perspective - none! The humans are property, and making your property more productive and happier is an obvious moral choice. Humans are, obviously, not people - they eat vegetables, aren't covered in fur - so they shouldn't get the same moral consideration. [Answer] If you have several (human) generations, don't make them happy. Make it horrible. A life of slave labor and subsistence farming and devoid of educational opportunities. Kids have got to grow up knowing that life is toil. This is your first "we're better than everyone" bonding moment that I totally stole from what I remember of the descriptions Emperor's prison planet in Dune. You've killed most of the pet species, so you can control any rebellions that might spring up. Once morale is low enough, select certain pets that demonstrate desirable qualities. Give them titles and spoil them with treats. Appoint a few as ombudsmen or "union reps" for their fellows in specialization (lap pet vs. sex slaves). They should relate to one another as better than those who don't have titles and traits showing worthwhile breeding. Spay/neuter your pets and keep them happy with whatever cocktail trips their trigger. Think the eldest son in Farnham's Freehold (if I recall correctly, he was either too intoxicated to notice or accepted intoxicants as a suitable substitute for his castration). [Answer] **Cultivate a furry fetish amongst humans** But how? Keep most of the earth exclusively habited by humans. Encourage people to be working long hours, but give them lots of possessions. Encourage them to enjoy their possessions rather than interactions with fellow humans, and be [bowling alone](https://en.wikipedia.org/wiki/Bowling_Alone). If they do interact with other humans, let it be via the internet. Soon enough, they'll [stop having sex](https://www.theguardian.com/world/2013/oct/20/young-people-japan-stopped-having-sex). When that happens, you start getting fetishes. And where do you get those fetishes from? The internet. When you're on the internet, [no-one knows that you're a cat](https://en.wikipedia.org/wiki/On_the_Internet,_nobody_knows_you're_a_dog), secretly manipulating humans. Keep the felines in a particular part of the earth. A place where travel is only by plane or boats, so that people can't enter or leave without your control (say Japan), and control the flow of information from that place, so no-one knows outside of Japan about the feline control of the planet. Lure those with the furry fetish to that country. Once they get there, some may agree to be prostitutes to felines, and some may not. Keep the former, and kill the latter. [Answer] Religion. Make them believe that if they live a "good life" (where good life means "work hard for your masters without any complaints") they will have a wonderful eternal life. Make them believe there's an all-loving god which will take care of them, but that he demands you follow his rules. Make them believe that any deviation means they'll be tortured in hell forever. So, basically, the feline overlords take Christianity, and make some tiny adjustments. [Answer] Target people who feel like they need to escape; anybody in an abusive relationship will do, but runaway youth are especially good targets because they don't always know how to take care of themselves. It's not foolproof, because some of these people are very hardened by their experiences, but enough of them will be apathetic or thankful enough not to rebel. [Answer] There is a non-intrusive, non-harmful way to do things: **Selection.** First of all, just make sure that not one of your slaves comes in touch with schooling. Ignorance is bliss! They will never feel the need to be free if they're cared for and kept away from each other -remember, man is a social animal, must not be given the chance to form a group. Second, inbreed them: Any advanced sentient species knows how dangerous to mental health is inbreeding, so make sure that they are tamed by genetical means. Have that trait breeded generation after generation, and masters won't have to worry about revolts. Third: eradicate immediately all rebellious individuals. If their streak reproduces, they can pose a problem in the future. A discrete thing, no public retaliations, so that nobody feels like 'solidarizing' with the rebel ]

[Question] [ TLDR: **How can a 100-strong hive mind utilise our superpower in order to generate \$1billion as fast possible?** All 100 of us share a common mind and can think as one. Instant, undetectable, thought transfer. None of us are rich, but we're all currently employed in low-paying jobs. Must keep low profile. Can be amoral. --- **Backstory:** Earth has been slated to be deconstructed for raw materials for an intergalactic empire. A single alien environmentalist travels to Earth, just to double check that the planet is truly empty and barren, like the official report says. To her shock she finds billions of biosignatures from millions of unique species. She travelled here using a constant acceleration relativistic drive (FTL is impossible, obviously). 4 weeks elapsed for her (most of which she spent in stasis out of sheer boredom) but 1000 years passed for everyone else. When she left the robotic planet-dismantling harvesters were 2000 years away, now they are only 1000 years away. To stop them, she needs to send a detailed report of the life forms found on Earth, including details of the breadth and depth of humanity, to the nearest embassy of the galactic empire - 495 light years away. They will then need to signal the robotic fleet to stop - another 495 light years of communication. She must send that report in 10 years otherwise it will be too late and Earth will be destroyed by the time the "cancel" signal reaches the robots. Her ship's communicator isn't powerful enough to send a message that far, and her ship has no FTL. Her drive could get her to the embassy in about 700 years - but by then it'd be too late for Earth. Her tiny ship can't attack the robotic dismantler fleet (she has no weapons and they fire in self defence). And she can't do anything herself - she has no knowledge of Earth's capabilities, resources, or tech. In desperation, she uses her race's natural hive mind abilities to form a connection with 99 random humans on the planet. Their minds are linked into a 100-body being with 1 common mind as powerful as all hundred, and with the full knowledge combined of each of their lives. This hive mind - we - awake to the realisation of just how screwed humanity is. After some brainstorming - we've calculated the only workable solution is to build a very complex constellation of long-range transmitters in deep space from hybrid Earth/alien tech, write a report on how non-barren Earth is, and transmit it, all within 10 years. After some intense eBay-ing, lots of shopping around, and getting bulk discounts where we can, we've written a shopping list. It's not cheap. We need about **$1B USD within 10 years** to purchase the parts we need, although sooner would be safer. That's \$100m per year. \$1m per body per year. Minimum. We have a super power (our hive mind), but that's all we have going for us. **How can we utilise our hive mind in order to generate a large sum of cash as fast as possible?** --- **Details of how the hive mind works:** * The connection is completely undetectable and unjammable by any Earth technology. Works through faraday cages. * Respects relativity - no FTL info transfer. This has a max range of about 2 light seconds (600,000km) before the connection cuts out temporarily. (This is for safety reasons - "Death by Lag" is bad way to die). Returning a member within range will auto relink the hive mind. * The further apart we are, the slower we can exchange information, and the slower we respond to events. (Reflexes excluded). Distributed around the surface of Earth we're passable for normal humans. * Idle minds can help busy minds think. If 99 of us are sitting idly gently meditating and 1 of us is getting an IQ test, expect an IQ of about 190. * If all 100 of us are getting the same IQ test done at the same time, we work together to solve it, expect IQs of about 190. * There are inefficiencies in the system when 100 brains need to think 100 different things simultaneously. If all 100 of us are getting completely different IQ tests simultaneously, expect measured IQs of about 90. * Information exchange is total and complete. We know every members deepest darkest secret. Information is replicated like a [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table), so the death of one of us doesn't erase what they knew from our minds. We have access to all memories of the aliens "home" hive mind, that's how we know how to build the communicator. * Sensory exchange is total and complete. We know everything that any of our eyes have seen, the instant they see it. Thought exchange is instant. (instant = speed of light transfer) * Mental skill exchange is total and complete. Everyone in the hundred can now speak and understand English, French, Mandarin, and all the other languages of the 100. * Physical skill exchange is imperfect as each body has its own unique control functionality, but still its very fast to transfer a skill from one body to the next - One guy was a really good juggler, after 10 minutes of practice, a body which had never juggled before can now do a 5 ball cascade. * Mental health issues are basically eradicated. Some hormone imbalances continue, but having 99 other points of view of every issue so deeply connected to one's own view helps minimise the negative effects. Your OCD / Anxiety / Depression / PTSD is basically outvoted. * Bodies that are sleeping still contribute mental power to the hive. * 100 is the maximum number of minds linked together at any one time - we can't expand it. * We're stuck with the 99 humans and 1 alien. No easy way to change which humans are in the hive now, shy of flying one of us 2 light seconds into space. * Death of a member in the hive is more traumatic than losing 99 soul mates. Self sacrifice / suicide missions are an option but the cost will be very high. --- **Other info on the initial state**: * We are currently scattered randomly over the planet, speaking various languages, varying skin colour, ages, citizenships, genders, etc. Some of us are dirt poor, some of us have comforts and **some resources but nobody is a millionaire**. We can afford to get visas, fly all members to one location and rent a big building for a few months as a starting point, but that's about it. * It was perfectly random. Expect ~18 Chinese, ~17 Indians, ~4 from USA. etc. ~50 males. ~50 females. Etc. * All of us are employed in some way currently, but nobody has a really high paying job. We have lots of people earning a few dollars per day as farmhands in 3rd world countries, and a few office workers in the first world. Odd fry cook and pizza delivery guy thrown in too perhaps. Nothing over $50k USD / yr. * Nobody under 18 is in the hive, nobody over 60 is in the hive. * We need about **one billion USD over the next decade** to complete our task on Earth, this includes parts, fuel for the space ship, normal human living expenses, plus a space to work, plus cover businesses, etc. * The robotic planet dismantlers will defend themselves if attacked, and will not notice the billions of screaming creatures, even if humanity puts up a giant "stop" sign - they'll just dismantle it for raw materials. If they see life they'll dismantle them. * The alien's body is spending all its time writing the report and building things with the expensive equipment purchased. 99 human bodies are free to work full time on getting as much money as possible. * The alien information isn't particularly monetizable, we don't have their full archive, just what was known to the alien researcher and their home hive - most of their mid to high end tech needs elements which are really rare or absent on Earth, and the other low end tech we have schematics for are things humanity has already achieved. It was luck we can even build the long range communicator. * We can use our existing space ship to launch things on the cheap, quickly, and secretly. They need to be launched out of the solar system (away from interference from solar wind), and are unlikely to be detected by Earth. * The motivation for getting lots of money to complete the mission ASAP is enough that "**ends justify the means**". Compared to the earth-ending consequences of not sending this report, minor things like "theft" or "mass murder" are footnotes. We'd obviously rather finish it in 9 years with no death than 8 years with mass murder, but our morality is clear on this. * We want to keep this quiet and **away from scrutiny** as much as possible, as if anyone knows about the hive mind or the alien we'll risk a vivisection, on either our human or alien bodies. [Answer] Insider trading and market manipulation. Somehow (probably a mix of good luck, raw intellect and deceit) position half of your people inside large, high profile companies, preferably inside legal or financial departments. If you get lucky aim for upper management. The other half should set themselves up as stock traders, aside from one who founds a ‘tech startup’ (the front for building your messaging apparatus). By engaging in dubious trading practices such as sharing inside information, all working together to dupe other traders into making bad investments, and cleverly selling stocks and shares your various hands should be able to funnel frankly ludicrous amounts of money into the tech startup. Since there is absolutely no link between the various people (and you can further avoid suspicion by varying who makes money when and establishing cover motivations for why they put money where they do) nobody will be able to prove collusion. If your tech startup is also likely to be profitable on its own you can probably get even more money through legitimate interests. Sure, a whole bunch of pension funds and investment portfolios will be defrauded to the tune of millions, but that’s hardly an issue. Your biggest problem won’t be raising the funds though. It will be *spending* them, since a lot of people will want to know where the money is going. Again: this is where a tech startup comes in handy. If you position it in the right sector then the cost of the main project will seem like a minor part of the operational costs. So something like a space company getting billions in funding for developing reusable rocketry or an electric car manufacturer... The main issue here is getting people in the right places, but with 99 people’s brains and a bit of luck you should be able to swing that... right, Elon? [Answer] **A Rich Philanthropist** Several members rock up to see Bill Gates and privately tell him the truth. The fact you're a hive mind means you can prove your story by doing stuff that he can't explain any other way. Show him your designs and your list of required components. Tell him what it's for and why. Offer to let him keep the system after you've finished. Remind him that announcing the existence of aliens will be met with ridicule at best or world wide panic and any knowledge needs to be trickled into society as not to create alarm and remind him, he's currently in the drivers seat and is creating a legacy for all of mankind. [Answer] # Lottery rigging Lottery rigging schemes have [been successfully executed](https://en.wikipedia.org/wiki/Hot_Lotto_fraud_scandal) before. They tend to be uncovered fairly easily because practical considerations around human nature make the schemes easy to defeat. In a nutshell, if the guys running the lottery take the winnings, catching them is trivial. If they get friends and associates to do it, it's not quite trivial but still pretty easy. And bringing strangers or the mob into it is *far* riskier for the would-be corrupt lottery worker. ### Unexplained windfalls are easy to detect Not only is it illegal for folks running the lottery to even play, the authorities know who all those people are. Monitoring their finances for unexplained windfalls is time consuming, but the number of people is small enough to represent a tiny fraction of the cost of doing business. This is true even if you extend the dragnet to family members and close associates. ### Strangers and trust issues The problem with getting a stranger to claim the prize for you is trust. If you trust the person enough to believe they wouldn't screw you over, they're not a stranger, they're a close associate (i.e. see previous paragraph). So because the authorities can keep you from bringing people you trust into your little conspiracy, you're left dealing with folks you *can't* trust. That's a problem for two reasons. One, the front man can tell you to go pound sand, keep the money, and dare you to call the cops. Two, while being the front man making the claim is still a crime (namely, conspiracy to rig the lottery), the authorities likely cut a deal with the front man to make an example of the crooked lottery worker. ## Hive Mind = Total trust None of this is a problem for you, a group of *seemingly* completely unconnected individuals that actually are all just you. This completely defeats the lottery's main defense against insider threats. Complex technical protections exist, but - see the story I linked - a skilled insider, such as yourselves, can defeat them. That's usually the easy part. The hard part is supposed to be getting the money. That's not a problem anymore. There is absolutely no traceable link from your lottery winners to the inside men. What used to be the easy part is still easy, only now it's all you need to rig the lottery. [Answer] # Nation-state-scale espionage There's really no reason to keep this a *complete* secret. Choose a nation state, (probably the US, since your motivation is money) demonstrate incontrovertible proof of undetectable telepathy, and then add "oh, and I have telepathic connections to 18 Chinese nationals with absolutely no previous connection to foreign agents, and existing, 100% foolproof covers". The CIA will sit your ~4 US operatives in rooms with, oh, nuclear physicists, aerospace engineers, cyberintelligence experts, that sort of thing, and teach the hivemind enough so that your Chinese nationals can rapidly become prodigies in those areas, and over the course of the next couple years, start integrating themselves into major industries and political systems in China. (they will also likely use the other agents similarly, in both allied and enemy countries) This is a literally priceless intelligence asset. Agents whose handlers can communicate with them untraceably, who can learn skills 100x faster than ordinary agents, who never need to make contact with each other but can remain in perfect coordination. Once your utility has been demonstrated — and that should only take a couple years — you can basically name your price. [Answer] ### Poker Tournaments There are several of them. And you need only to pairs in each "team", one playing, another watching the TV, for see the cards of all players. Harvesting the most competitive ones, and a lot of local others, could easily make more a million per pair per year. **Bonus:** Make some then famous, poker start celebrities. Make a few of then compete with each other. Book revenues, interviews, motivational talks for companies... Some influencers get paid 50k USD **per post** of product placement. **Bonus 2:** You could make you story cover *both* sides. The technobabble sci-fi side, and the glamorous gambit facade. [Answer] I question the assertion that things must be launched out of the solar system. Instead: Approach the National Reconnaissance Office with a proposition. You ask no questions and we will deploy satellites for you with no launch signatures. Stealth them and nobody will know they're up there. Try to find out who are and we will deorbit your satellites instead. [Answer] Exploit your secret, unjammable communications. * Cheating: Go to a game show where the contestant must answer questions without help. There are 99 helpers in front of a computer with an internet connection ... Bet on sports events which are not transmitted live. One at the event, one in the betting parlor. * Optimizing: A member on the London Stock Exchange will see events in Toyko slightly faster than the message travels through cables and satellites. Can that be exploited, will the human factor cancel any benefit? Work in a job where teamwork in a bad-communications environment counts. Professional ocean yachting? Get a sponsorship deal. Those are not going to get the billion without catching attention, but millions, maybe? [Answer] Before the mind can make money, the author needs to define the group. First, work through your assumptions. Assuming a random selection, evenly distributed around the globe, you have about * 60 Asians * 16 Africans * 10 Europeans * 9 from Latin/South America/Carribean * 5 from North America There is a very low chance of anyone from the Pacific/Oceania. There is also incredibly low chance that any of these people know each other already, and a merely low chance that any are in the same city. Over half of your mind in Asia, but that spreads from India to Siberia to China to Japan etc. Still a very big area, suggesting that coordinated action is hard. To get a team or even pairs together, someone's going to have to move to gain the added bonuses of working together. Of those 100, 14 can't read or write (but you have addressed that by shared knowledge). 9 don't have access to drinking water and 18 don't have electricity. Shared brains won't change that. While its plausible the 100 could include an astronaut in space or a president or a rock star or a billionare, its vanishingly unlikely. You'd lose believeability if there were any. --- One possible dichotomy could arise from **Religion** * 31 would be Christian * 23 would be Muslim * 16 would not be religious or identify themselves as being aligned with a particular faith * 15 would be Hindu * 7 would be Buddhist * 8 would believe in other religions. How does a devout (X) deal with a heretical (Y) suddenly inside their head? There is a cop-out answer that "the hive mind transcends all religion" but there will also be dissension inside the hive mind and they won't mesh like a well-oiled geartrain immediately. --- Above numbers are from <https://www.100people.org/statistics_detailed_statistics.php> --- Another risk is mental stability - there's a non-zero chance that one or more of the group will go off the rails mentally. It could range from a little potty, right through to a full-on psychotic breakdown. This may paralyse the hive mind into inaction or at least lowered potential. --- Start by getting the poor and impoverished hive mind members to move to places where there are financial opportunities. --- There's even a very low chance any two would work for the same employer. The largest employers in the world are according to <https://en.wikipedia.org/wiki/List_of_largest_employers> ``` Employer 2015 Chance U.S. Department of Defense 3.2 million 0.043% China People's Liberation Army 2.3 million 0.031% USA Walmart 2.1 million 0.028% Global McDonald's 1.9 million 0.025% UK National Health Service 1.7 million 0.023% ``` So trying to leverage two people in the same company is highly unlikely, unless you can get them employed. But consider that most employees are not senior leadership, and have little sway or say in how the company works. [Answer] **Get paid for science** With 99 people together, working single minded on a single project with staggering IQ's they'll be able to whip out impressive technologies. Inventing better data storage solutions, faster hosting or new AI methods can be quickly implemented and tech giants pay ludicrous amounts of money for this. This can give you a starting capital, if it doesn't already pay the full amount over the years. Alternatively you can use this knowledge to do crime on the internet, stealing bitcoins or other internet crimes that are difficult to trace. If this isn't enough, which is likely, you at least have money and in some cases reputation for the next part. You start researching new ways to travel in space. The advantage is that you have an alien with at least superficial knowledge of high speed travel and energy suppliers in space. This means you can home in on that and give some very good hypothesis on this. With this research you can go to any government with a space program or the joint space programs. If you pitch such advanced technologies to China, they'll be all over it and simply pay you to build the required stuff. This does put you close to scrutiny and being found out, but the worth of such a space program is already enough to let you live. At least for now. To prevent people finding out they are connected you can have a few people on site, while the rest is secluded in secrecy in a self made company estate. No one needs to know more than one person theoretically, but having three to five at the space program excelling any task of the space program will be difficult to find out if they're always seen together. Of course they know what their fellow is doing, as they hardly do anything without the other. That 90 other people are sending them knowledge all the time is impossibly to detect. They'll just seem like weird super geniuses. [Answer] If you're okay with going the villain route, having the ability to launch things secretly and cheaply allows you to become a deadly **terrorist organization** easily. Find some heavy things (rocks, tungsten rods), fly them to space, aim that at whoever you want to extort, and drop it. See [Kinetic\_bombardment](https://en.wikipedia.org/wiki/Kinetic_bombardment). Send notes to military officials in a few governments that there will an impact at a specific time and place, then drop a big rock. It'll look like a meteor to most people, but those who have gotten the note will be in a panic. Do it a few more times, possibly at increasingly high value targets, and you'll have their attention. You could take part of your hive and start an organization that "somehow figures out" how to predict these impacts, and become **government contractors**. Threaten the world and save it - making money off both sides. [Answer] The answer is fairly easy, and doesn't require a lot of effort, just some trauma. Have one of your members kill themselves, and grab a billionaire. There's lots of billionaires around, and some are accessible. As soon as you have one you can start working and save the planet. It's hard removing one of your number, sure, but it's the quickest way to save all life on the planet. Other methods require much longer. Suicide missions are an option, you said- this would be a solid method to do it. [Answer] This anwer ignores the fact that the spaceship will make billions of dollars by itself. This type of communication in our age does not have any legal benefits. As it is very easy for everyone to communicate at close to speed of light. Either you should use it to cheat or not rely on it at all. For cheating it can be used in quiz shows, competitive gaming and gambling. While these could be profitable, they are not sustainable. You may win so many prizes before people get suspicious. Skill transfer is luck based. If your hive has a very in demand talent or skill, you may make quite a bit of money. Being a top-notch 3D designer or a computer vision programmer pays quite well. Make 10 of your guys work in best jobs in high paying countries. You will probably save at least 1M$ from 10 guys in a year. Having a top-notch singer or a method actor will not hurt. If you have a good football player, you may try to build a football team. You need 18 guys for the team, one as coach, and some around the stadium for top down view. With perfect knowledge of the entire field as well as the location/direction of your teammates might give you enough of an edge to get you to the top of a very well sponsored league. Sadly most of the extremely high paying jobs are not a personal merit rather than being in the right place, lifelong devotion, and having the charm. Thus this method is somewhat limited too. Build a cult around few of your people. Try to collect as much donations as possible. Since you have real supernatural powers, you can easily convince some high profile people. Grab 4-5 years worth of collected salary and donations and gamble with it. Two strangers watching a game of poker will not be suspicious if none of them reaches for their phone, or they are not even in the view of our player. With this you may quadruple your earnings but I don't think you will be able to push it any further than that. All in all, I don't think you will be able to get to a billion easily. You need a lot of luck. [Answer] **Paramilitary/mercenary action** Your 100 people are the ultimate fighting force. It's probable that you'll have at least one person in the hive who's some sort of fighter (military or otherwise) and combined with the fast training rate of the others, you could assemble quite the powerful combat force in a very short amount of time. Some advantages a squad of hive-soldiers would have: * High skill: using high IQ and multiple people training at the same time, even hive-unknown skills can be rapidly acquired. The hive can rapidly become an expert in marksmanship, tactics, strategy, EOD, piloting, intelligence work, etc. * Intelligence superiority: Some of the hive can become soldiers; military forces are always looking for them and embedded hive members can leak sensitive intel covertly to the rest of the hive. * Battlefield coordination: Because the hive is one and does not require radio or anything else, they can always be in perfect sync. Provided a good tactical plan, a unit of hive-members would only be stoppable by vastly superior forces and even then they'd have a good escape and evade chance. * Immunity to psychological issues: Provided the hive is willing to kill and is immune to PTSD and similar issues, each soldier in the hive is a perfect soldier. They have unwavering determination, focus, will-to-kill (which is a big issue for the military), and discipline. * Counterintelligence superiority: The hive is impossible to infiltrate and has the highest possible level of operational security. For example, the "command bunker" could be located on the other side of the planet meaning that the operatives would never need to leave behind documents or really any clues as they can just have someone else look up and manage data. **The Game Plan:** Send the operatives into the target location. This target location should be war-torn, unstable, or otherwise rather lawless. It shouldn't be too difficult to acquire basic weaponry. You want somewhere where there are high value targets (HVTs) that nobody would be particularly upset to see eliminated. For example: * Ocean freighter pirate gangs * Unstable dictatorships * Fanatical terrorist organizations * Large international drug cartels Working their way up from smaller to larger targets the hive-operatives target these types of operations, killing the pirates, terrorists, smugglers, etc. and taking their stuff. Using this stuff, they outfit themselves to face bigger and badder foes, working their way up the food chain and collecting ever larger amounts of loot. Targeting these organizations is a quick way to make money because: * HVTs often have expensive weaponry. Maybe they've stolen American missiles, maybe they're being sold Russian weaponry under the table--it does not matter, but whatever they have, it's expensive. Possibly, you can sell this confiscated weaponry back to the US government as a private contractor and get that sweet, sweet, government money. * HVTs are often flush with cash. If you break into the right cartel base and steal all their stuff, you can probably get away with a couple cool millions in cash or even cryptocurrency. For cartels, the biggest problem is usually laundering all their money (eg why Escobar buried so much of it) so they're likely to have it laying around * HVTs often control money making systems that you can take over. Oil and resource dictators are rich and terrorists get their money from somewhere. In fact, you could probably take over a small country and depose a dictator, replacing them with your hive-operatives. Running a country is a good way to make money. The most difficult part of this all is probably laundering the money afterwards, but since you have many people who are unconnected, you can probably do so in a country where they don't have that many controls and checks on their fiscal instruments. Unfortunately, I don't think it's possible to paramilitary your way to 1 billion dollars. It's simply too much, however, I do think it's possible to turn a hundred million dollars (totally achievable by a mercenary force) into a billion over a ten year span. [Answer] ### Collude to make a virtual monopoly from all the companies in a market segment. Many jurisdictions have anti-monopoly and anti-collusion laws. Eg 2 businesses in competition with each other can't agree on prices, or unite their buying or selling power. If they were able to make an agreement and buy as one, they can negotiate a lower price from suppliers, and they can collude on their retail price. They can maximise profits by not selling anything cheaper than they need, and not buying anything wholesale for anything more then the minimum. This is a bad thing for both farmers and consumers, but an excellent thing for retailers. It's a major white collar crime in several jurisdictions. So your 100 get jobs in the back offices of all the major supermarket chains. By working discretely with your counterparts in your competitors, your categories will be exceptionally profitable - as you you can squeeze producers down to the lowest wholesale price possible (you control all their other offers), and set prices for the consumer as high as possible (before consumers switch to replacement products.) After a few years of turning every category you touch into a profit machine, you'll get promoted high up in the company. Within 10 years I'd expect you to control all the major decision makers, be able to set salaries for each other, and be rorting your nations food producers and consumers to make an extremely profitable sector in order to support these large salaries. By keeping your communications entirely within the hive and never writing down anything, or meeting each other, you'll be able to rort farmers and the middle/lower classes for a decade to make your companies rich, and writing your own salaries in the process. [Answer] ### Check out your playing field * You can make money from normal people, 1000 coins at a time. * Small businesses can yield 10 000 to 100 000; also local drug bosses are in this class. Forget everything up to this point, it's just not enough. * Medium companies can give you something between 1M and 10M but you have to deliver serious stuff. International drug/people smugglers, terrorist heads, sects are in this range, too, if you want to steal money. You can get investment funds up to this fairly easy if you have a convincing concept, a great presentation and some contacts. Large research contracts are in this area, but normally you have to fight off internal university politics and the involved states also have their claims. This kind of money can at least get you started - with 1M you can for example feed your 100 people ten months so that they have their hands free for something else. This illustrates that you really NEED much money, too. * very large companies invest 100M up to 1B, but it is difficult to convince them, plus, the disadvantage is that you have to deliver afterwards, which can bind your 100 people. The world drug boss of any random illegal (or even legal) drug (tobacco, alcohol, pharma, cocaine, doesn't matter) could give you that kind of money but prefers to buy arms and estates. However, those people need to do money laundery and having 100 trustworthy people distributed about in like 40 nations is a huge, huge advantage in that business. The "launders" often keep two thirds of the money. A hand full of stock traders and billionaires also have that kind of money and don't know where to store it in times of negative interest rates. Talk about a return on investment and you can get it. Develop something in a rich country and take rich country's money, but pay the developers in Nigereia through your local person in Nigeria so that you have a high gain situation. Corruption in some states can also yield money in that range, but then you have to get your way up inside the bureaucracy first until you finally land in a position where you can milk the money out of the state; the time frame may be too short for this. Examples for these kinds of ultracorrupt positions are Russian high bureaucrats, the army of Venezuela, the Senate of the US (if connected to the arms or oil or pharma business), or likewise any number of middle east oil state princes. Then there are also "priority investmens" of any number of states. Those states have some kind of program going, like the Chinese want to be leader in the electric car business, the Germans want to renovate all of their electric grid, Puerto Rico needs new infrastructure. Those state programs usually have exceptionally bad control compared to private companies and can leak out astonishing amounts of money into private pockets. You can't take everything but you can have a good start with 100 million or so and continue from there. * The top league: Find an area, where tens or hundreds of billions are spent. This is no private sector anymore, it's state affairs. Like, a random war can quickly cost 100 billion, a social security system as well. If you can get one of the 100 in a leading position in the EU, China, US, as a "minister of " anything expensive, you can leak away 1% of these monster-investments or raise taxes by 0.5% and even have your legal reasons for buying all the stuff your alien needs. Out in the open. Here your 100 persons need to concentrate on a single state, however, and that can be difficult if they are from so many different countries. But then, use the money laundry capabilities and the perfect alibi to murder and intrigue your way up to the profitable positions. [Answer] Forget the hive mind information transfer network; there's little benefit to another way of sending information around the world wirelessly and securely these days. The only places this will benefit you is the type of places where phones etc are prohibited, which means very high security jobs. Getting even one person into one of those will be hard, and the moment you pull something off, you'll be in solitary confinement until you explain how. Your best bet is to **leverage the alien's tech knowledge** to make discoveries which are beyond current earth tech, but not unbelievably so. 99 entrepreneurs making big discoveries might get you 10 successful projects, which might get you your 10Bn. There will be some scenarios where the immediacy of the situational awareness will beat any current tech. If your hive awareness means you know where everyone else is, you can do things like have two people juggle to each other blindfold, using a 3rd person's eyes. So think performing arts, team sports, and military. Military is your last option – even with this, there's a significant risk of losing a team member. Performing arts will be hard to make enough cash. You'll be lucky to get far even in a TV talent show. So **sports** is the best option to use this. Pick your 11 best athletes, and make them a football (soccer) team. Use the rest to fill the roles of coach etc. You've suddenly got a team that can run rings around any other team as they can see behind themselves, pass perfectly without having to communicate, etc. You've got a few guys in the stands watching to get a bird's eye view of the other team, and the rest can think tactics. You should be able to dominate a sport. However, this will probably still leave you an order of magnitude short – ManU has a value in the region of 1.5Bn. But you may then have enough capital to re-invest it into other projects. [Answer] Members of the hive mind share not only knowledge and skills, but also life experiences, take advantage of that. With 100 members of different walks of life and both genders, you know all there is to know about human relationships. You are also an expert at reading body language and similar skills (and you don't need any one of the members to be an expert in this area, it is enough that for any situation you have 1 out of the 100 who had a similar experience). You can use these skills in several ways to make money. Building on Thorne's earlier answer, you can be a master of seduction and have a billionaire marry you. Then you can either introduce the alien to your spouse, or get the money through manipulation. Alternatively, find some rich people with dirty secrets, trick them into revealing said secrets to you, then blackmail them (preferably via a different member). Of course, you need to meet some rich people first. Targeting their employees is an obvious option. You can also use your intelligence, and the fact that you speak 50+ languages fluently, to become a minor celebrity, and with some luck you'll have the opportunity to hang out with the right people. [Answer] **Perfectly organised crime** *Arson* - One of the many people in the hive mind could vandalise valuable positions, the worth of the positions would be exaggerated when insuring them so that there would be a big pay-out from the insurance company, use others in the hive mind as fake witnesses and accuse suspicions people from that area who would be caught on CCTV entering the crime scene. Eg: The hive mind all put money together to buy a jewellery shop, suspicious individuals would be mislead into entering the store, a fake robbery would occur where all the witnesses would chase them out of the store and accuse them of vandalising products or stealing jewellery that was snuck into their pockets like a reverse pickpocketing (The jewellery would be damaged/diamonds 'fall out' of them beforehand so that you would still be able to claim insurance). [Answer] **You could make over a Billion cheating at gambling and chess.** **Casinos** * **Use orbital decay theory to cheat at roulette**. A computer is required to do the orbital decay theory calculations. One person is at the casino, the other is at home with a laptop. These cheaters ran away with $15 million. <https://thetechportal.com/2017/04/03/cheating-roulette-technology-banned-vegas/> If 100 people do it then you've got 1.5 billion. Obviously after the world's casinos have lost half a billion or so then they might stop offering roulette. * **Card counting with blackjack**. It is possible to get an edge of about 2% by counting in your head. If you use a computer then your edge goes up to 7%. Winnings would be similar to cheating using orbital decay theory. **Chess** * Computers are much better than humans at chess. One of your people, say a Vietnamese villager becomes the chess world champion, making about 10 million in the process (Magnus Carlsen has 8 million net worth). Then once they are famous they deliberately lose a few games. The others bet on the games. You could probably make $100 million per year this way With both of these approaches casinos and bookmakers will start banning you. This is the limit to how much you can make. The best way to avoid the ban is to show up as a high roller, walking in with a million or so. Then it's less suspicious if you walk out with 2-3 million. The guys who were caught doing the orbital decay theory approach walked in with nothing and after a few casino visits they were multimillionaires. That never happens naturally, but people regularly double their money at casinos by chance. [Answer] **Seed money** Kidney donations pay out 1,000 to 10,000 USD. You have 99 you don't need. Let's say this starts you will 5,000 x 100 (round up for easy calculation) = 500,000 USD. Good start. **Casinos** Split up in pairs and go to 50 different casinos. One person per pair plays poker (or other games of hidden information) and the other is a spectator who looks at other players hands and transmits them to the player. Splitting up will help keep a lower profile and mitigate risk of any pair being caught. You have a few years, so don't get carried away at any one location at any one time. [Answer] Take your most attractive female members and use them to marry men for money. You could also engage in some prostitution or camgirl sites on the side. Once you have a bit of money, start a few companies and shift the money around. Give "personal loans" to one another so they can start small businesses, but instead of spending the money, send the money on to another member and cook the books. One good way of doing this would be to start another company which provides goods to the smaller companies--goods which they never receive. You can use these companies as a front for money laundering if you want, but really what you need to do is take out insurance and torch the place. You have plenty of people to provide alibis. Another good thing you can do is use your members to "love bomb" desperate people and have them go into debt to pay for meditation courses and books required by your cult. You can also use them as cheap labor using cult tactics to keep them in line. One thing cults do is have members write sort of "fan fiction" about themselves as if they were a bad person, and then the cult threatens to release these "confessions" if the cult member doesn't behave. Maybe sell the cultists into slavery or for spare parts depending on the opportunities that arise. Finally, you can go the Epstein route. Have your attractive members lure rich people into private parties and either video tape them doing things, or just make something up and say you have a lot of witnesses (you have people who will lie). They have to give you money, or you're going to release information that will get them raped and killed in prison. Maybe download CP onto their computer and use that for leverage. Since you have so many people, you could probably procure some kids yourself. Kids would be little gold mines if you're willing to work with the wrong people. [Answer] Offer to create software solutions to companies all over the world: * There is awesome talent here * The internet allows easy collaboration * Language is not a barrier, and there are translation apps * One can be selective with the projects one chooses * There would be a need to advertise the services * A project manager would be required for the project(s) * The start up costs are minimal to non existent ]

[Question] [ Characters with powerful telekinesis are portrayed as being able to exert a superhuman force using only their minds. For example, they can throw a car. Based on what I remember from high school physics, throwing a 2000 kg vehicle to 10 m/s requires an impulse of 20000 N⋅s. But Newton's 3rd Law states that momentum is always conserved and every action has an equal and opposite reaction. So exerting a 20000 N⋅s impulse—whether by gravitational, magnetic, or other means—would throw an 80 kg superhero backwards at 250 m/s. Even if they could survive that, it would be awfully inconvenient to walk back to the battlefield. No violation of Newton's 3rd law has ever been observed by experiment, so even saying that our hero can draw on a vast energy source doesn't solve the problem. So how could our hero throw a car without also throwing himself? Can the momentum be put somewhere else? Or is there a way for our hero to use his powers to protect himself from harm? Note: I'm not looking for a scientific explanation for where the superpower itself comes from, just a little logical consistency. Truth be told, I mostly want a headcanon for when I watch X-Men films. [Answer] They could brace themselves against the world behind them. Basically, they would subconsciously learn to simultaneously exert an equal and opposite force spread out over a much larger area behind them or anywhere else that isn't the car they're throwing. A sign of an amateur telekinetic could be being thrown back by their 'throws' because they haven't learnt to do this yet. The area would be so large the force would be spread out such that that anyone in it couldn't tell someone was using telekinesis without precise scientific equipment. A true master, optionally The One True Master, can focus that opposite force into a second useful target. Example use cases are smashing enemies into each other in combat, or, more grimly, tearing an enemy apart. [Answer] **Let us consider the humble FET** Here's a rudimentary description of a Field Effect Transistor (FET): Imagine water moving through a pipe. When the gate value is all the way open, water flows through the pipe freely. As you close the gate valve, the water through the pipe is restricted until the valve is finally closed and no water can flow. The magic? It takes a *lot less ~~water~~ energy* to open and close the valve than is represented by the water flowing through the pipe. Why is this important? Because that's the basic operation of an *amplifier.* A little effort is applied to open or close the valve, but it controls a lot of water. And if you track the opening and closing of the valve over time (say it looks like a Sine wave, smoothly opening and closing, back and forth...), and then track the water flow through the pipe — you'll find that it's the very same Sine wave but MUCH BIGGER! Woot! **Now, let's apply this to your telekinesis** What your superhero is *actually* doing is acting like the base or gate of a transistor. He/she is creating/managing a channel of force between, let's say, the rotational momentum of the Earth and the object (oh, let's say Hoover Dam) to be tossed about. But your superhero isn't channeling that force directly. He/she is simply setting up the channel, and then controlling it as the gating function. A little effort in, the destruction of Laughlin, Nevada out. Maybe a minor stress headache as a result. You know, the mental equivalent of a tired wrist from turning a screwdriver too many times. **But my superhero can't be godlike!** Absolutely not! But even FETs have limits. They can't channel infinite amounts of electricity. Superheros with this ability come in many sizes! Some can gate/control enough of the Earth's rotational momentum to kick a poodle. Others have no trouble slinging cars around. There was that one dude, *Whackismo!* back in the 50s... he actually diverted an incoming meteor! Which was *COOL!* Right up until the governments of the world figured that not only could he easily rip the doors off of Fort Knox, but that his saving of the world *actually made days measurably longer....* People figure the last time anybody heard from him was October 3, 1956. It's probably best that we forget. We'd hate for *[Majestic 12](https://en.wikipedia.org/wiki/Majestic_12)* to think anybody was remembering him. **Wait... did you say the *days got longer?*** Oh, yeah. There's a consequence to drawing energy from the Earth's rotational momentum. If you draw enough of it, the rotation slows down and days get longer. You could draw it from Earth's orbital momentum, but then the years would get longer. *Technically* you could draw it from Earth's solar trajectory momentum, but that would probably cause the Earth to slowly change its orbital elliptic — you know, the angle of the orbit compared to the rest of the planets. That could be fun. [Answer] # Frame Challenge: My Invisible Friend Joe You’re looking at this the wrong way. If I tell my friend Joe to go pick up a rock and throw it, and he does, I will never experience the associated ‘equal and opposite reaction’ because I’m not the one doing the throwing. You’re imagining telekinesis as reaching out an invisible arm from yourself, and assuming that arm has to then also push you back when you use it, but there’s no reason telekinesis has to work that way. Detach the arm! Think of it like having an invisible friend named Joe who happens to really like doing stuff you tell him to do, and is more than happy to throw a few cars around if you ask nicely. Joe follows the third law, of course, but Joe follows the third law the way that a tornado picking up a car does. It doesn’t get thrown back, it just loses a little of its existing momentum. ### Fun twists This also lets you experiment with fun story beats about Joe turning out to be less metaphorical than you initially thought. Nothing more distressing than discovering your telekinesis can be grumpy, or on vacation on another planet. Or, even better, why have one Joe when it could be an army of invisible flying pixies? [Answer] Not entirely answering the question, but Newton's Third Law isn't the only problem here. A far greater problem is [conservation of energy](https://en.m.wikipedia.org/wiki/Conservation_of_energy). Lifting a 1 tonne car against gravity by 1m needs 10kJ of potential energy. Accelerating that car to 10m/s needs 50kJ of potential energy. Several other answers have actually covered where this energy might come from. Unfortunately they've confused momentum and energy. It's important to be clear which is which! The character Molly in [Runaways](https://en.m.wikipedia.org/wiki/Runaways_(TV_series)) has another solution. Her telekinesis is powered by her body's stored energy reserves (if they'd wanted to get technical, they could have mentioned glycogen, but they didn't really need to). So after lifting something heavy, she's exhausted like she's just run a marathon, and she goes to sleep. It's one of the few instances I've seen where a superhero actually follows physical laws. [Answer] Psionic/Telekinetic stuff is basically magic though, if you need the realism of "the force needs to go somewhere", then the hero could displace, disperse, or redirect it as they see fit. Oh, or maybe fold it into a pocket dimension if you're talking really potent stuff. [Answer] You can store momentum kind of like the way a capacitor can store energy. The momentum density of the electric and magnetic field is $$\frac1{c^2}\vec S=\epsilon\_0\vec E\times\vec B$$ where $\vec E$ is the electric field, $\vec B$ is the magnetic field and $\epsilon\_0=8.85\times10^{-12}\,F/m$ is the permittivitiy of free space. So if a being had an organ where they[?] could create and maintain sufficiently strong electric and magnetic fields, they could change their momentum without changing velocity. The problem is that the dielectric strength of air is about $3\times10^6\,V/m$ and $1\,T$ is a pretty strong magnetic field, about the most you can get with a NdFeB magnet, and $1\,L=10^{-3}\,m^3$ is about as much volume as a human-sized being could reasonably invest in such an organ so this would work out to about $2.7\times10^{-8}\,kg\cdot m/s$ so it would only be a sufficient momentum reserve to perhaps win a few bets at a Belter bar before the other patrons got wise to you, but hardly in the ballpark of throwing cars around. Not to mention that it may turn out that the sources of the electric and magnetic fields have to have equal and opposite momentum to that which was created in the internal organ... [Answer] > > ... magic had indeed once been wild and lawless, but had been tamed > back in the mists of time by the Olden Ones, who had bound it to obey > among other things the Law of Conservation of Reality; this demanded > that the effort needed to achieve a goal should be the same regardless > of the means used. In practical terms this meant that, say, creating > the illusion of a glass of wine was relatively easy, since it involved > merely the subtle shifting of light patterns. On the other hand, > lifting a genuine wineglass a few feet in the air by sheer mental > energy required several hours of systematic preparation if the wizard > wished to prevent the simple principle of leverage flicking his brain > out through his ears. > > > -Terry Pratchett [Answer] If you pick up 100lbs in telekinesis then you would have to simultaneously redirect that 100lbs of force elsewhere or it will instead be exerted on the psychic. Effectively telekinesis would be an invisible arm connected to you and you have to use a second arm to distribute the weight elsewhere, unless you want to become beastly strong. Or perhaps your telekinesis requires you to set 2 predetermined points for weight distribution. If you pick up a car all you are doing is making an expanding telekinetic pillar under the car which is distributing the weight downwards. If you want to throw it while its in the air then you have to connect the car to a nearby building and exert equal force on the car and the building. If the buildings walls are weak then you may just punch a hole in the building and not move the car much. That could get pretty complex when thinking about it but might actually make for interesting tactical fights. [Answer] **Wormholes.** A wormhole near the object, connects to a place with strong gravity (eg. Jupiter). The gravitational field pulls the object, and all you do is control the location (and existence) of the wormhole. *Caution:* If the wormhole gets too big, material will pass through it. Put on end at the bottom of the Marianas Trench, and you get a high pressure stream that can probably cut through concrete. Best to keep "standard" wormhole size smaller than a water molecule. [Answer] Why does it have to avoid violating the Third Law at all? Newton's laws are not really laws, but simply an approximation and are known to be incomplete. There are a variety of situations where they don't apply. Telekinesis is, by definition, "spooky action at a distance," so we're already throwing Newtonian physics out the window by invoking it and moving into more accurate descriptions of the world such as quantum mechanics and relativity. The best way for your telekinetic heroes to avoid the 3rd law is to reframe telekinesis not as imparting a *force,* but as changing the *reference frame* definition of the action. Newtonian mechanics are only valid in inertial reference frames, so the easiest thing to do is to say telekinesis creates a non-inertial reference frame. The most common example of this is gravity. An object in a gravitational field doesn't feel a *force* of gravity acting on it, it feels an *acceleration.* A force is defined as F=ma, meaning that the force an object "feels" is affected by the mass of another object pushing it. To figure out how an object moves in response to a force, you divide the force by its mass and get the acceleration: a = F/m. But gravity works differently. Regardless of an object's mass, it always experiences the same acceleration; a feather and a hammer fall at the same speed and hit the ground at the same time when dropped from the same height in a vacuum. This fact is why scientists often call gravity a "fictitious force," in that it is indistinguishable from an acceleration caused by any other means (rocket, elevator, guy pushing you down the street, etc...). When you're in freefall towards the Earth, you're not pushing on the Earth, nor is it pushing on you, you're merely accelerating towards each other. Newton himself noticed this disturbing fact about gravity but said "leave it to someone else to figure out." Eventually, Einstein did, and he found that objects always want to move in "a straight line" between two points, or more accurately, "the shortest-time path." This is called a *brachistochrone.* It turns out that gravity is a manifestation of this fact, in that the definition of "the shortest-time path" takes on a curve when matter is present. This curving of space-time immediately invalidates Newton's first law: Namely that an object at rest must remain at rest or travel in a straight line unless acted on by a force. With gravity, the object cannot obey Newton's first law and must move, even though a force isn't acting on it! The second law also immediately falls, as it states that "the momentum of an object doesn't change without the application of a force." Momentum is equal to the mass times the velocity of the object, but here we're imparting a velocity, simply by the fact that we're near an object, even without touching it! As mentioned previously, in freefall neither you nor the Earth exhibit forces on each other, you just *accelerate* towards each other. This invalidates Newton's third law. The entire reason gravity is so weird and scary is because it *imparts an acceleration on objects **without** the presence of a force!* It does this by literally changing the rules of the game (by warping the stage, space-time, so that is no longer flat). This is also one of the reasons its so difficult to unify with the other forces. So, the best thing for your telekinetic physics is to say that it bends space around the object it acts on to cause it to "fall" in the desired direction under the influence of a kind of gravitational field. [Answer] I think the answer to your question is found in relativity, since it gives us our understanding of space-time. Sometimes telekinetic powers let people fly — like Marvel’s Legion — and sometimes they let them lift and throw heqvy things. When a powerful telekinetic pushes on something, they reach out at the same time, telekinetically and grip space-time. This anchors them in one spot. Then when the telekinetic exerts the force on the object they want to move, the equal and opposite force is applied to the very fabric of time and space. The telekinetic is the fulcrum in this Archimedean simile. I see the consequences of this interpretation as: 1. The telekinetic can amplify their TK force by anchoring themselves to a very near point in time-space 2. The telekinetic can amplify their TK finesse by anchoring themselves to a distance point in time-space 3. The maximum possible force is limited by the strength of time-space. If they try and exert too much TK force then they form a singularity and get sucked into it and poof! 4. A more skillfull telekinetic can anchor themselves to multiple time-space points, distributing the reaction force they generate so they can exert more force than if the just anchored themselves to one point in time-space 5. If they don’t anchor themselves to time-space, then when they exert their TK force, they experience the reaction force and levitate/fly/slide/whatever (depending on the direction and the mass of the thing they pushed on) 6. If they anchored themselves on two points in time-space and pulled really hard they could form a wormhole or time-space tunnel for traveling great distances ]

[Question] [ In Mark Twain's "A Connecticut Yankee in King Arthur's Court" a nineteenth century character finds himself in medieval England and shortly manages to build all the "modern" inventions: from steam engines to Gatling guns. While this is entertaining, I find it hard to believe that a single person would be able to introduce those modern world inventions without the backing of industry and science. So let’s say that modern twenty-first century engineer/scientist/[MacGyver](https://en.wikipedia.org/wiki/MacGyver) travels back in time, but to make it more interesting lets make it to the Hellenic Greece around 490 BC and a good fate would allow him to became an influential person. But he knows that in 10 years Xerxes will arrive with huge army — how can he prepare his city-state to fight off the invaders? Of course by using his knowledge — but then he can't like the Twain's Yankee just handwave and build machine guns in a country that still mainly relies on bronze. What then should he try to re-invent and build? EDIT: 5 years seems to be a short span, I've changed it to 10. [Answer] I am far from the first to [think of this](http://discworld.wikia.com/wiki/Clacks), but alphabetical long distance signalling, whether by [Semaphore line](https://en.wikipedia.org/wiki/Semaphore_line), [heliograph](https://en.wikipedia.org/wiki/Heliograph) or [shuttered lantern](https://en.wikipedia.org/wiki/Signal_lamp) gives you the biggest bang for your buck as an invention to introduce from a low technological base. Given that the Greeks already had alphabetic writing many people have wondered why they or the Romans *didn't* think of it. Just one of those things, I suppose. [Naval flag signalling](https://en.wikipedia.org/wiki/Naval_flag_signalling) using pre-arranged flags to indicate certain manoeuvres was apparently known to the Greeks, but did not extend to a system able to send any message. Two-way signalling faster than a galloping horse will transform the Greeks' defence against Xerxes, although they will need to be aware that he will eventually copy the idea. The Greeks do have the advantage of home territory, so they can build towers in advance. To keep their signals secure the Greeks will need to develop ciphers and codes for military and later commercial use. Once your time traveller has got them started on the idea - which by [some accounts](https://en.wikipedia.org/wiki/History_of_cryptography) they had already had for themselves - there are plenty of ingenious mathematically-inclined Greeks to take codemaking and codebreaking forwards. In an earlier [answer](https://worldbuilding.stackexchange.com/a/18456/9207) to a [similar question](https://worldbuilding.stackexchange.com/questions/18451/travel-back-in-time-and-rise-to-power/), I borrowed some more ideas for innovations to introduce from L Sprague de Camp's 1939 novel [*Lest Darkness Fall*](https://en.wikipedia.org/wiki/Lest_Darkness_Fall) in which a time traveller introduces distillation of spirits as an immediate money-maker, and Arabic numerals to eventually transform the society of sixth century Rome. For that answer I forgot to mention another long term idea from the same book, [double-entry bookkeeping](https://en.wikipedia.org/wiki/Double-entry_bookkeeping_system#History), but remedy that omission now. In the long run the ledger entry is more powerful than the sword. [Answer] Simple military technology would make the biggest impact, some ideas. The [longbow](https://en.wikipedia.org/wiki/English_longbow), along with conscript soldiers using the massed volley firing technique would outrange generally existing bows, but more importantly the ability to raise a huge force of minimally trained conscripts to provide the massed fire would be devastating to the professional soldiers/armies of the day. The [stirrup](https://en.wikipedia.org/wiki/Stirrup), along with the idea of a massed cavalry charge would be very effective against foot soldiers of the day. The [trebuchet](https://en.wikipedia.org/wiki/Trebuchet) able to throw massive loads very long distances. The greeks of 500BC had begun experimenting with simple catapult/mechanical bow throwers. This would be recognizable and generally understandable to them, and effective against fortifications or massed armies. These ideas would be fairly simple to implement and manufacture at the existing technology level, and would provide a massive improvement over generally existing military methods. [Answer] If the defense is the main concern I think gunpowder is the most feasible advanced technology to introduce on a disruptively large scale with the resources available at the time. It would be possible to mine saltpeter (Potassium Nitrate) from somewhere like Spain, Sulfur is right there in Greece as is Charcoal. Grind them together carefully with stone tools to create gunpowder. Its not feasible to create accurate firearms with the available technology in that time frame, so employing it in explosive devices would be the best bet. It would likely be easiest to inflict the largest amount of damage to the enemy when they are still ship-bound, so deploying naval mines could be one successful tactic. If unable to catch them at sea, then using them as ammunition in catapults or as land-mines would be both devastating and terrifying to an ancient army travelling in columns. [Answer] To fight, I would reveal the secrets of biological warfare (and how to avoid catching germs yourself), iron, gunpowder, and large scale opium production. If I can't get them hooked on dope, kill them off with a plague, stab the remainder with incredibly sharp and durable spears, blind their archers with smoke bombs, collapse canyon walls on their convoys with dynamite, frighten their horses with cannon, and generally make it look like Zeus himself had come down mysteriously from Olympus to help a civilization that already had the genius of Athens, the fury of Sparta, and the courage of Thebes, then perhaps all is lost. [Answer] Consider the number one killer of troops of the day, poor or inadequate medical facilities. You can effectively double and redouble your ranks if soldiers that would have died from infection can return to battle. You would further reduce your losses of intelligence and invested training. Start now with sterile facilities, reduced cross contamination, and proper waste disposal. Make it a culture of the people for continued civilization advancement. So to answer the question, I believe modern sterilization practices(technology) would have the greatest positive effect on a defending force. Utilize your other prior knowledge to earn support then make this recommendation. [Answer] When the Persians ascend the goat path to flank Thermopylae they will be met with another army that wasn't there an hour before. While there are stacks of useful inventions to take back and I have them in tables, the bootstrap sequence is long, but the history books are right there. We know the very hour of doom. My army shall be fresh and equipped with steel swords and spears and armor that cannot be broken. Though the bootstrap will not permit large quantities, the choke point is in my favor. Two hundred fresh men well equipped and well supplied are hard to dislodge from a choke point where only one man can approach at once, so narrow was the path. [Answer] Archimedes used parabolic mirrors back in the day to create the first energy weapon; they weren't that backward. Use the concept of polished metal mirrors as an energy source, start ironworking. Even cast iron would be a major improvement over bronze weapons. Gunpowder in clay pots mixed with metal shards gives you grenades. Hygiene practices reduce disease in crowded camps. The concept of germs and the basic microscope would revolutionize Greek medicine. This would require the concept of glass lenses, but glass blowing already existed since at least 1000 BC; it would not be an unheard of concept to the Greeks. Basic mechanics to design better tools, improve weapons, design siege machinery, build stronger boats faster. If the Greeks only managed to only double their productivity by the time the Persians landed, it would still be a winning advantage. Most importantly, he would know WHEN the Persians would invade and get the Greek to coordinate their defences.The major reason the Persians got as far as they did was that only the Spartans and Athenians were in any shape to field a fighting force. On the other hand, once word reached Persia that the Greeks were advancing, Xerxes would move up his invasion schedule. [Answer] I will make a counterpoint here. Greek society was built around Yeoman farmers who had roughly equal landholdings, roughly equal economic outputs, stood together as equals on the field of battle (the Hoplite Phalenx) and used this as justification to stand as equals in the *Ekklesia* as part of the democratic government of the *polis*. One reason the Hoplite phalanx evolved the way it did was it specifically excluded the poor (who had no weapons to effectively attack a wall of bronze) or the Aristocrats (who's main contribution was javelin armed cavalry, also an ineffective tool against a fully formed phalanx). So whatever your innovations are, they must be first and foremost acceptable to a class of Yeoman farmers who value both their equality and their ability to hold the power of their society. Longbows or other weapons that help the poor, or stirrups and shock cavalry which would help the aristocrats, would be considered horrifying and destabilizing for the Greeks, and indeed if introduced before the Persian Wars, would probably result in Greece being embroiled in a series of civil wars between the various class elements. As an aside, the introduction of effective naval technology which allowed the Greeks to take to sea on equal terms with the Phoenicians (and win the battle of Salamis) ended up being extremely destabilizing to the Greek Polis system. Athens granted full citizenship to the rowers because of their performance in the Persian Wars, and this large block of relatively poor, landless people allowed Athens to become "hyper democratic" compared to other city states, develop quite different interests and priorities and become prey to Demagogues. The critical naval technology? A sliding sheepskin seat pad which allowed rowers to make longer and more powerful strokes on the oars when manning a trireme. So perhaps the best possible solution would be to introduce more effective non mechanized farming techniques, to allow the Hoplite class to expand and provide more savings and investment to the overall Greek society. The Greeks did pretty well during the Persian Wars, having a stronger agricultural base would simply provide greater defensive depth to the Greek city states, and make it much more difficult for Xerxes to advance into Greece. The long term effect would be to make the Persians think twice about a rematch (and if the Persians didn't come back for a second round, the Greeks and eventually Macedonian King Alexander III would not be thinking about overthrowing the Persian Empire in return). [Answer] Kicking off an industrial revolution is hard, technology require an energy source and you need quite advanced technology to access most energy sources, it would be a nightmare to build geothermal or hydroelectric power plants from bronze age technology. If there was a large near-surface deposit of coal in ancient Greece you could build steam engines and kick start industrial infrastructure but as far as I know they mainly used charcoal because coal wasn't readily available. The five year limit is tough too, it's hard to introduce radical new technologies so quickly, I suppose you would have to limit yourself to upgrading branches on the existing tech tree. For example teaching them modern medicine, metallurgy, basic mechanical engineering, invent a flywheel powered lathe, pasteurization and other food preservation techniques. Edit: Inspired by navigator's answer. Two or four man lever operated pumps, long hoses (perhaps partially buried if defending a strategic location) and barrels full of "greek fire" which is probably lamp oil mixed with something. The pumps and fuel can be transported in an armoured cart but obviously you would want to keep it away from the enemy and the hoses would be vulnerable, hence burying them to protect them from arrows. [Answer] This question deserves a solid list and treatise, though I suspect that such a treatment is beyond my capabilities. I'll list some possibilities that occur to me, for others to expand upon: * Mathematical innovations (e.g.: [imaginary numbers](http://blog.oup.com/2015/10/imaginary-negative-numbers/), [logarithms](http://www-history.mcs.st-andrews.ac.uk/Biographies/Briggs.html), [irrational numbers](https://en.wikipedia.org/wiki/Irrational_number) [and decimal counting, calculus, etc.]) * Medical discoveries (e.g.: [penicillin](https://en.wikipedia.org/wiki/Penicillin), [microorganisms](https://en.wikipedia.org/wiki/Animalcule)) * Materials technology (e.g.: [plastics](https://en.wikipedia.org/wiki/Plastic#History), [nylon polymers](http://www.chemheritage.org/discover/online-resources/chemistry-in-history/themes/petrochemistry-and-synthetic-polymers/synthetic-polymers/carothers.aspx), [aluminum from bauxite](https://en.wikipedia.org/wiki/Bauxite)) * Semi-modern methods (e.g.: [Napoleonic canned goods](http://www.thekitchn.com/breakthroughs-in-food-science-canning-218083), [Babbage difference engines](http://www.computerhistory.org/babbage/engines/)) * Less modern (to us) inventions (e.g.: [repeating crossbows](https://en.wikipedia.org/wiki/Repeating_crossbow), [trebuchets](https://en.wikipedia.org/wiki/Trebuchet)) [Answer] The assembly line, replaceable parts, and "tools to build tools". The advantages of many of the other inventions that other people have mentioned (cross bow, trebuchet) could be massively multiplied using assembly lines to create large quantities of them and also focusing on replaceable parts so that broken equipment can be fixed more quickly. This can even apply to technology they already have, e.g. ship assembly lines or shoe assembly lines. (Side note: For a humorous fictional take on this, see Larry Niven's "The Flying Sorcerer".) [Answer] I am really surprised that noone has mentioned this so far: Greek Fire ([wikipedia](https://en.wikipedia.org/wiki/Greek_fire)) Pros: * the greeks actually did win against Xerxes and did so most decisively on the sea (battle of salamis [wikipedia](https://en.wikipedia.org/wiki/Battle_of_Salamis)), and greek fire was used best on sea * while the original formula is unknown, there were some substances with similar effect over the centuries * it seemingly had rather sopicticated delivering systems, but simple granades were known too * it was created and used in the same region, so the ingredients needed should be available * it has greek in the name ;) [Answer] ## Dynamite (A late 19thC technology so not the toughest option) The reason the battle was fought at the Thermopylae was because that was the only place the Persian army could get through. Given dynamite, you have two options. * Close the pass that was used to outflank the Greek army * Close the main pass at Thermopylae itself If you can time this to split the Persian army in half then you've got an easy win on the war at your next battle. --- ## Failed option: Steel (3rdC onwards) As you mentioned, the Greeks were mostly still running on Bronze. However in practice steel doesn't seem to offer significant upgrades in the field as bronze still performs very well. When a man is cutting you off at the knees, you don't take the time to check what his weapon is made of. [Answer] * Professionalize the army. The Romans built their empire on top of their legions - professional, experienced soldiers that were disciplined and knew how to fight as an unit. Standard weapons also meant that weapons were interchangeable and can be "mass produced". * Introduce high quality steel. Iron is better than bronze and steel is better than iron. Steel swords, chainmail, helmets, etc will give you a huge advantage on the battlefield. * Binoculars. Relatively easy to make, huge intelligence advantage * Any agricultural improvements your engineer could affect will lead to population growth which in turn means more soldiers. * Improve hygiene / healthcare. Obviously means more and healthier soldiers. * Communications - build a telegraph stations in key location so your lookouts can relate troop movements to you. [Answer] Glass. Glass would be useful for telescopes and profitable as building and art materials. You can melt concrete using just a lens. See troops in the distance. Better than silver for reflection. Uses of microscopes would jumpstart a lot of the ideas about teaching people about germs. You guys are forgetting, that people didn't believe there were little bugs on their hands that caused illness. It took years of campaigning just to get **doctors** to wash their hands before surgery. But it would be unsurpassed in generating monetary value. I believe you can buy Manhattan with just a few boxes of glass beads. Side note: Gunpowder would probably get you killed as a witch. [Answer] People have some great answers on here, and certainly medical advances would be paramount if possible. Basic hand washing in lye would be really easy to do, and sterilizing water with sun or heat, but it is so esoteric many people would probably not listen(see the issues with modern day third world countries). Penicillin would be an option, but after a quick google, it looks like getting a pure form is challenging <http://io9.gizmodo.com/in-case-of-apocalypse-heres-how-to-make-penicillin-in-1110902296> and even if you find a way to make all of the things needed for it, you run the chance of bad luck at the beginning which could end up with your neck in a noose. So I figure 2 things would be great: 1. introducing materials and metallurgy advances. Composite woods would make a big difference, as certainly would better metals. Refining iron ore into basic steels is actually pretty easy, and then from there it could fairly quickly be turned into armor, wheels, swords, arrows(Yay the longbow idea), crossbows, stirrups(also a great idea), etc. and they would be things that people could see and hold so they would certainly start using them. 2. Hot air or hydrogen balloons This is a fun one and might not be achievable in 5 years (unlike steel), put a wooden water wheel on the side of a river(bonus you introduce water driven mills for wheat grinding). Put the gears in it to get a small dowel spinning at a high speed, extrude some copper wire. Go find some natural magnets in all of the limestone in that area, and bam you have an electric generator. You can use this to create hydrogen and oxygen from salt water, and then use the Hydrogen to fill wood framed leather and pitch dirigible. Don't bother with engines, just float that guy up there tied to a rope and use it for long distance spotting, or fill it with archers and rain arrows down from above and well out of range. [Answer] # Dental hygiene Lack of dental hygiene in WW1, may have killed more people than bullets. Introducing the toothbrush (fairly simple concept, easy and cheap to make) could dramatically improve the lives of the Greek; on top of that, it wouldn't change the balance of power in the Greek society. # Better materials Not just metals, but pretty much anything will do. Quality bricks would allow for better and stronger buildings, or at least, houses that are faster to build. With a strong binder, you could quickly build what amounts to a medieval castle which would be virtually unsiegable. Building castles will disrupt the power structure of the Greek society and will require a large amount of people for the construction. Minor fortifications might be a better options. # Viking longboats I'm not too sure about this -- the real strength of the viking longboats lies in its maneuverability on rivers. At any rate, they are strong, lightweight and don't require a lot of materials. They rival modern (recreational) sailboats for speed, on open waters. [Answer] Building on the 'better hygiene' (brilliantly simple) I'd suggest military tactics and training. Ancient battlefields are basically slugging matches in which nummerical advantage and morale play a major part. Try to impose modern tactics on a slugging match might rob the enemy of many nummerical advantages. [Answer] I have little to add to the other answers (there are a plethora of technologies that would be incredibly helpful). However, there is one technology that has escaped mention that I think would have been very revolutionary in a number of ways: *electricity*. Ancient Greeks already had access to large amounts of copper with their established bronze economy. This could be fairly easily made into flat wire or even round wire with basic tools of their time. Using this to create a basic generator or other simple electrical devices wouldn't be exceptionally difficult. If you were able to get access to basic [magnets](https://www.ucl.ac.uk/EarthSci/people/lidunka/GEOL2014/Geophysics9%20-Magnetism/Useful%20papers/Magnetism.htm#:%7E:text=The%20ancient%20Greeks%20were%20the,magnetism%20systematically%20using%20scientific%20methods.) you could possibly produce simple electric motors as well. These could be used to create new technologies or augment existing ones: electric powered tools (such as lathes, presses, or saws), electronic signaling and communication, and possibly even electric lights. However, this would be slow in developing in comparison to other technologies. But given enough time, it would be the farthest-reaching and most influential technology I can think of. [Answer] Steam-based automatic weapons (ala [The Cross-Time Engineer](http://rads.stackoverflow.com/amzn/click/0345327624 "The Cross-Time Engineer") by Leo Frankowski). ]

[Question] [ I'm the mayor of a large city, and I'm up for re-election. My poll numbers have slipped after a recent scandal (don't ask), so to make up ground, I need to appeal to my most vocal constituents: evildoers. In particular, they want me to take on the issue of superheroes. Now, I've already made being a hero difficult in a lot of ways. There's a registration process, a nightmarish bureaucracy, and all sorts of checks by the police force. But one place there's still room for improvement is the tax code. Which brings me to my main question: **What taxes can I impose to discourage superheroic behavior?** Some constraints: * I can't directly tax heroes without alienating my non-evil voters, so I need some plausible deniability. * Ideally, these taxes should primarily harm heroes without affecting villains or everyday citizens too much. * I want to target people who use their superpowers to fight evil. I can't stop people from having power, so I want to give them a monetary incentive to not be heroes (or better, to be villains). * Taxes do need approval, but the city government is in the pocket of Big Evil, so that won't be a concern. * The easier it is to scale, the better. If all goes well, it might even get me to the White House. * Thanks to the registration, heroes can't dodge taxes with secret identities. * People with powers are numerous and diverse enough that I can't just target one demographic. Thankfully, most don't choose to be heroes (and I'd like to keep it that way). * Heroes vary in power, but are generally on the weaker side. * The heroes earn a bit less than regular police officers. The police don't have superpowers to protect them, after all. [Answer] Add a two tier tax that targets heroes doing property damage. First, a small flat tax for all heroes to help cover any damages incurred by villains and subsequent hero suppression of said villains. Its easy to propose such tax, a heroes job doesn't end until the city is restored, or so you claim. The second tax is less talked about, gets easy approval, and is a huge boon for villains. A direct tax for heroes who damage property. Or you could call it a ticket or a fine, whichever works. Basically any hero who creates property damage has to pay this fee, and it makes defeating villains a lot harder, because now you have to avoid property damage while fighting. Heroes who can't avoid it will be taxed into oblivion, and you can even get rid of pesky heroes by sending waves of villains who can make them cause property damage. Watch as your ratings go up, your city gets richer, and villains get even more villainous. [Answer] **Muahahahahaha!** Taxes take many forms for many reasons. Bear in mind, all monies collected by government for any reason is by definition a tax. And most importantly... *At city levels, most taxes (fees & regulatory codes) aren't seen or approved by voters. There's only a public meeting no one attends.* * Impose a fee for dropping off criminals at the local jail and dead people at the local morgue. * Since superheros are taking policemen away from their normal duties, bill the superhero for the police's actual time + resource usage + depreciation of assets, and charge a fee on top of that. * Since superheros are taking the limelight away from the *true* heros of your town, charge them a fee for every appearance in the newspapers or any/all media campaigns. * Impose an annual fee to permit operation within, beneath, or above your city. * Impose a fee for certifying superheros as actual officers of the court and not simply vigilantes. Outlaw vigilantism (which already exists in most cities, btw, usually in the form of being illegal to "impersonate an officer"). * Impose a luxury tax on all merchandising associated with superheros. * Pass building code regulation that requires superheros to make their residences absolute fortresses without appearing any different from any other building in the surrounding area. The code should mandate walls capable of absorbing a cruise missle impact, radar, underground vehicle access to secluded areas, etc. Make it as costly as you can imagine. And then there's the taxes that make people hate the superheros. You know, "the price we pay as a society to enjoy the benefits of powered people." * Create a ~~health care plan~~ general insurance fund for the damage caused by superhero actions "for the sake of the people who are innocent victims of superhero necessity," tax everybody to fund it, then use it if the superhero so much as breaks a toothpick to justify the highest possible tax. * Create a "Superhero Legal Aid Fund" that supports legal representation of everyone affected by superhero activity (innocent bystander and criminal alike). Tax the snot out of the public to fund it and then use it to get your evildoers off the hook. * Create a "Superhero Identity Protection Fund" that is "necessary to protect the privacy of our superheros," ostensibly to help superheros protect their secret identities, then use it in the most inefficient way possible to hire as many people to do as little as can be conceived — like manually ~~surfing~~ analyzing Google for leaks. (Most governments should have little trouble implementing this — especially when pitched as a jobs-creation bill.) [Answer] I think you might underestimate just how powerful a weapon red tape can be. Why merely tax their money when you can also tax them with effort? Announce that your economies drive has had the unfortunate local repercussion of some segments of the electorate having to bear a fraction(ahem) of the cost of necessary government administrative procedures. Now reform your tax code so that as to increase by an order of magnitude the number of papers needed to officially register as a hero. You can achieve this by blatantly displaying bloated and duplicated legalese all over. Time to apply a variation of the [Rhodesian solution](https://www.youtube.com/watch?v=pGJH_-S_MGs). Ensure your forms are of shoddy make so that they're easy to accidentally on purpose damage or smudge over, in the name of cost savings of course. Make superheroes deliver them to government offices by hand and install a special superhero toll booth right outside your offices(sadly necessary because of austerity). Then stage a false flag attack on the paperwork itself that destroys it in a dramatic fashion. Claim that collateral damage from heroic action was responsible for the tragic loss of tree life, and apply hefty fines to assuage the doubtlessly outraged public. So now the superheroes pay for all of the eleventy-hundred forms they need, they pay to get into the office they need to deliver it to, they pay when the forms gets 'destroyed by reckless vigilantes', and they pay for new forms when their applications are no doubt 'lost' in the bureaucratic machine somehow, and they have to pay to find out the status of their application. To deal with their complaints, set up an inquiry committee with broad terms of reference. Members are appointed but they'll never actually meet, but of course nobody needs to know that. You can implicitly suggest to the heroes that if they donate to you they'll get "reform" pushed through much faster. Yet another tax. To power all this bollocks you're going to need an influx of staff to fill an army of non-jobs. So to top it off, present *yourself* as a governmental superhero for reducing overall expenditure while increasing state revenue and providing employment. Superheroes shall tremble before the might of the most fearsome supervillain of all, the Uncivil Servant. *This is bureaucracy, this is bureaucracy, spreadsheets scream in the dead of night...* PS: If you're evil why shouldn't you just screw over everyone good and evil alike? Line your own pockets, while you earn some political points through a firm and masterly display of showing the electorate lots of activity...while actually achieving absolutely nothing. [Answer] Forget taxes. Forget registration. Forget bureaucracy. Your strategy should be around licensing. Taxes are painful, but superheroes just have to pay the government and move on. Similarly with registration fees. Relying on simple bureaucracy will leave you one, filling-out-forms-*is*-my-super-power superhero away from defeat. But, look at what you get with licensing: 1. Bad guys get what they want: a barrier to entry for super heroes. You can even put some supervillains on the licensing board! 2. Behavior of an unwanted (i.e., non-evil) kind can be condemned by the same licensing board. 3. You have a good excuse to not alienate normal people (aka "normies"). "Look, I'm just trying to make sure that what superheroes we have know how to do their job well and won't cause unnecessary harm to innocent bystanders." You can probably get many upstanding citizens to help advocate for this as well. 4. This is maybe the best part: once a superhero has done the needed superhero training, passed superhero tests, and gotten approved by the super-villain-populated superhero licensing board, they've invested quite a lot of time, and they need that investment to pay off. They probably won't want newcomers cutting into their superhero earnings. So the superheroes now have incentive to prevent other law-abiding, moral, super-powered people from becoming (or even calling themselves!) official superheroes. You won't need to do anything, your opponents will do your work for you. [Answer] Most taxes fall into just a few categories: income tax, consumption tax, property tax, estate tax, or capital gains tax. Some of these are unsuitable because they would either tax heroes too directly or not directly enough. Income tax, estate tax, and capital gains tax would have to target heroes directly (i.e. different rates for heroes), so that's out. Property tax wouldn't target heroes directly enough, unless they all tend to live in one district/area. You might get some traction with consumption taxes. Slap a levy on spandex suits, capes, and high-tech crime fighting gadgets, and you're effectively creating a tax that only crime fighters will have to pay. Some villains will grumble about the higher price of their jet-black costumes, but tax evasion should already be in any good villain's repertoire anyway. Another alternative to "tax" is to charge a hefty fee for hero registration. Charge $10,000 for registering as a hero, and you will certainly have fewer people doing so. You might wind up with a hero vigilante problem, however, as unregistered heroes continue to fight crime. [Answer] Don't tax them, but rather pass a law that criminalizes collateral damage during super crime as a misdemeanor offense! This incentivizes both the hero and the villains to not engage in costly battles or take it out of city limits. It should not carry a hefty sentencing either. A minimum of a few hours of community service, a fine proportional to the damage caused, or jail time of one year. Thus, your Lawful Good super-strong flying brick types can be sentanced to clean up the abanodend warehouse district his fight destroyed (if he hasn't done so already), your brooding rich idiots with cool toy heroes and your capitalist CEO villains can make a donation to the city coffers to pay for the new Abandoned Warehouse District (if you can accept donations of valuable minerals, your Flying Bricks can also pay in formerly Coal type Diamonds), and you can give additional jail time to the truly destructive villains and please the Main Stream Media dislike of Arachnid Themed Super-Teens. This will also help with both urban blight (Why do we have an Abandoned Warehouse District anyway? I mean, it's just a breeding ground for low income villains) and Urban Renewal projects (They always bring in cash in the form of Super-Science CEOs who want to do things for the betterment of people in the city... they bring cash and are the leading cause of and solution too all our Superhero Problems). Plus, I hear these acts are wildly popular with the senior citizens, and they tend to show up at every Superhero/Villain fight for some odd reason. [Answer] I'm not sure a "tax" is appropriate or possible without affecting others that you don't want to target. I think a better approach would be a fine instead. Impose a large fine and probable jail time for "interfering with the duties of law enforcement officers". Basically obstruction of justice. That will only affect heroes (who are caught) and not anyone else in the community. The more aggressive the law is and the bigger the punishment, the less likely people will want to risk it. It just won't be worth being a hero at that point. [Answer] The simplest way to do this is to simply have a business registration fee for becoming a superhero. Since a superhero is quantitatively as well as qualitatively different from a toxic waste dump or other industrial concern, the fee structure will also be different. Of course, there will be people like that Wayne character who will refuse to admit to being a superhero, and not register. Well, they are now in violation of the law, and can be fined and assessed damages for operating without a licence. The longer these vigilantes operate, the greater the accumulated fines and penalties, so when they finally do get unmasked..... The other advantage of this is psychological, turning the people away from the very idea of superheroes. These so called "heroes" are not even fulfilling their basic civic duties by registering and paying a simple fee. What sort of person fails to fulfill a simple civic duty like that? A villain....thats who.... [Answer] Forget taxes, add buying insurance as part of the registration process (not any insurance will do, it has to be approved by the city). Have some of your evil rich friends run it. Over charge the insurance company, pocket some of the extra and pass the rest on under the table to the insurance board members. Now you have law that everyone likes and it will have nothing to do with you when it starts cost the heroes time, money, and hassle. [Answer] ## Tax psychotherapy Superheroes either need to pay more or turn into villains. Many superpowered individuals have to constantly deal with their personal demons. With great power comes great insanity. [Childhood traumas](http://dc.wikia.com/wiki/Batman), [huge pressure to fulfill ones responsibilities](http://marvel.wikia.com/wiki/Spider-Man), [post-traumatic stress disorders](https://en.wikipedia.org/wiki/Jessica_Jones_(TV_series)), [struggle to feel socially accepted](http://marvel.wikia.com/wiki/X-Men), [being a danger to people around you](http://marvel.wikia.com/wiki/Hulk), [awful work/life balance](http://dc.wikia.com/wiki/Superman), etc... The result of these crushing life circumstances is that most superpowerded individuals fulfill at least one [DSM](https://en.wikipedia.org/wiki/Diagnostic_and_Statistical_Manual_of_Mental_Disorders) diagnosis. This should make psychological health care for superpowered individuals an important industry. Any superhero would be well-advised to meet with a professional therapist in regular intervals in order to better process the experiences they make on a daily basis. Unfortunately (or fortunately, if you are Evil), many superpowered individuals do not seek professional help. The result is that many of them develop aggressive behaviors and a deep-seated hate for their environment. In other words, they become villains. In fact the majority of supervillains justify their criminal actions by some form of trauma or mental disorder for which they did not receive proper therapy. So making psychotherapy more expensive will not just increase the costs of living for the heroes. It will also turn more superpowered individuals away from therapy and towards a life of supervillainy. [Answer] **Unions!** Force all heroes to join the Justice Union. Unions can impose their own dues and fines. They can impose rules for anything. They can make everyone be on probation for 2 years before being allowed to fully use their powers. They can give everyone their own territories, thereby preventing cooperation. They can limit the number of new applications. Have a big heist planned? Union goes on strike! Any hero operating during a strike is immediately fined, license revoked, and jailed. Have a dastardly plot? Force all union heroes to pull extra security duties at the press conference across town! Heroes starting to rebel? Bog them down with years of contract negotiations! [Answer] Along with the other comments, theres room for a lot of ways to financially force limits on superheros. Registration is one thing you mentioned that could require a yearly fee, but you could have extra fees tacked on if they want to actually use their powers. A superhero license that requires a fee, along with training and tests that require fees. The argument being that having a natural talent doesn't mean you have the rights to use it. The education costs could be up there with college loans, leaving them in debt for long periods of time... which the government could "generously" wave if the hero decides to work for the government, with their rules in place. This would give the added issues of heros doing the bidding of evildoers as a matter of survival. The license could also come with a requirement of liability insurance. Making it very expensive to want to do anything. You could also make requirements regarding any items that they need... supersuits, cars, etc... by only allowing them to be made by government inspected and approved vendors (who could also be in the governments pocket and make subpar equipment that needs to be replaced often.) Vehicles of any sort could require yearly inspections, like smog checks almost... then they would need to pay the inspector, and the fees to license the vehicle, pay state fees for anything really... You could also impose limits to their power through fines if they speak against the government at all. Get the people on your side for that by saying that their added powers means that imposing their personal beliefs borders on threats... Abuse of power situation. You have to make the heros the enemy of the regular citizenship. If people think that heros are trying to force their own beliefs on them, they are more likely to be leery. Constant speech fines for abuse of power could lead to legal fees... like what happens if you have too many parking tickets... Do what many dictatorships do and post lists of superheros that have caused harm, even if they stopped someone from getting killed... did they accidentally kill the perps and therefore obstruct justice or interfere with police matters? That's legal fees and bail that can be collected. Start a "charity" for children whose parents were hurt by superheros. Make them seem out of control and risky... "think about the children". Added benefit to the obvious propaganda, donations from citizens. As far as taxes, it could be a "peoples relief tax" only applied to registered superheros... or if they are a minor, their families. The fund would be in response to any damages that may occur in a fight situation or just "wear and tear" over some over blown science journal that says something about superheros having a genetic composition that causes more wear on streets and sidewalks (etc.)... it doesn't have to be true. Regarding the minors and families... a kid's family is going to have to register their child as soon as they realize they have powers, and they will also have to pay that tax regardless of their own abilities. The registration fees for a minor can be higher, as children and teens can be more emotionally erratic. This would put a financial burden on the family that may make them not want to report their child... make it so that if it's found out they lose all property and the child becomes a ward of the state. This could also be a voluntary option for families with limited means, surrendering their child. This would probably be common, as all the financial stress would wear down any family, superheros would be something regular people would dread. As a ward of the state, the young superheros can be groomed however you like. And getting really dark...There could also develop a type of test for pregnant women to determine if the baby is indeed a superhero or not. The test could be free if you do it voluntarily, and state mandated with a fine if the parents try to get around it. (superhero fraud?) This would lead to people aborting superhero babies... which you could think of a way to spin it "for the greater good" but also make those situations money makers with state approved centers "capable of handling" the -insert derogatory terminology- physiology blah blah I think the key is to not only make it a burden to the superhero, but to society as a whole. You need your citizens to do some of the work of keeping them down as well. You may wind up with a homeless problem, which you could also work to your advantage as you can spin it as they are inherently worthless and lazy, as there was clearly the option of working for the government. (See, generous) This also may result in a boost in your approval ratings... as you are spinning things to make people believe that you are working in their interests. [Answer] Tax what the super-heros use would be my advice. You say your hero's are on the weaker side after all, If they need armour to be bullet proof tax that, if they need to move about in cars in the middle of the day then tax driving in off peak hours does specialised super-human healthcare exist in your world to take care of their enhanced bodies? if so tax it. These would likely be examples of indirect taxes, you wouldn't be taxing the superheros but rather the companies that supply them with gear. I'd especially advise a tax on lycra (perhaps on the grounds of "maintaining public decency"), sure cyclists will be annoyed too but there's always someone caught in the cross-fire. you can also discourage superheroes by encouraging other powered jobs. The more you pay your super-human circus freaks, power-plant workers, specialist army officers, Etc... the less people are going to want to be a superhero (in theory.) Also who pays the super-heros? Is it you? if so simply don't. [Answer] One critical aspect seems to be that super heroes are often in a hurry when trying to safe the world (or so); while this is also true for other people, super heroes are generally entirely capable of moving at very high speeds. So perhaps you should tax that? Then again, using taxes for this is kind of hard. Maybe you can tax ownership of flying gear (as a luxury tax, right?) and then interpret their superpowers as flying gear. That is, for those superheros that do actually fly. For those that do not you may be able to extract a road tax proportional to the speed at which the road is used (causes comparatively more wear and tear, right?). Besides, maybe you do not need any new laws; maybe enforcing those that you have strictly is sufficient. I am pretty sure, superman for instance violates [aviation safety regulations](https://en.wikipedia.org/wiki/Aviation_regulations). Note that there are a number of hilarious cartoons out there: * [Wiley Miller's "laws of physics strictly enforced"](https://www.gocomics.com/nonsequitur/2012/08/24) * [Your speed: 458 mph](https://m.blog.hu/be/bereljautotcom/image/cikk11_sohanemonddarendornek10.jpg) (I am not copying the cartoons in here because I am not sure whether that would violate copyrights. And I sure as hell don't want to be confronted by a copyright protecting superhero over this...) [Answer] > > The heroes earn a bit less than regular police officers. The police don't have superpowers to protect them, after all. > > > Well, first of all, don't encourage them by offering jobs in the police if you don't want them to be "heroes". ... or, if that's too obvious, make it mandatory to be a certified police officer, than "have only budget" for a certain (low) number of superheros (absolutely up to your discretion of course, including especially their approved powers). All other vigilantism remains prohibited with severe punishments. ... or do you actually hope to earn big on taxes coming from superheros instead of discouraging their despicable behavior ? (maybe bleeding them financially dry in the process?) In that case, should a powered person pursue a superhero career / activity : * enforce an expensive, elitist license scheme allowing such a thing (have marketing create the "apple" for superheros, with hyped up perceived status, way overpriced fees and a decade long waiting list for good measure) * levy the usage of assigned air corridors for flying (punish all other non licensed airborne activities) * introduce a tax / fine for exceeding certain speed limits * enforce a mandatory (expensive and controlling) membership in a psi corp for all mental powers (coincidentally with such an institution you'll get access to villains with mental powers and may use them to "re-educate" powered persons interested in becoming superheros) * charge hefty cleanup costs after superhero battles * tax teleportation and telekinesis for some reason or another * get pharmaceutical and biotech companies (under your or your villain constituents control) to patent DNA segments associated with / required for powers and then have them charge license fees for using those powers (this could then result in denying superheros a license thus making the use of their powers illegal, the very least a civil court patent / licensing matter, locking them in a years long legal battle with expensive lawyers and multibillion corporations, of course prohibited to use their powers by cease and desist orders) **If you want to get rid of superheros you can also instigate slanderous campaigns and see how many you can get imprisoned with trumped up or legitimate charges (including tax evasion, preferably the taxes regarding vigilante activities)** All your taxes can very easily and vehemently championed for by justifying them as * "for the children(s safety)" * "for the environment" * "for citizen security" * "for health and safety" * "for traffic safety" * "for keeping the peace / public order" etc. [Answer] ## Tax the hero identity and the secret civilian identity separately If Superman and Clark Kent claim to be two separate people, then they both need to pay their taxes. Any income needs to be reported by both people and they both need need to pay the tax. So any income of Superman/Kent is taxed twice. This, of course, also hits those villains who also have secret identities while it spares heroes like Jessica Jones who operate under their real name. But these are rather the exceptions than the norm. [Answer] ## Why tax them when you can force them to have licenses that require bonds Treat them as functionally equivalent to a [private investigator](https://privateinvestigatoredu.org/) in terms of how they get permission to operate from the government. 1. They have to attend mandatory classes / training. 2. They have to have certain education and experience requirements (apprenticeships). 3. They have to pass an exam that tests the things learned in 1 and 2. 4. If they use weapons, they have to receive firearm training and separate licensing there (i.e. state concealed-carry permits). 5. They have to apply for licensure. This includes a **surety bond** along with application fees, etc. 6. They have to maintained that license, with annual fees. The main point of the above to force them through a bureaucratic process that charges them incidental fees at various stages. No one fee is overwhelming, but taken as a whole, the process discourages do-gooders. When presented to the public, you're fighting for improved safety and making sure villains don't masquerade as good guys. The single greatest expense you find in that list will be [surety bonds](https://en.wikipedia.org/wiki/Surety_bond#Overview). This is where the hero must contract with an insurance company. That company has their own internal review process before agreeing to insure the hero. If the hero then does anything that violates the law, the bond pays for it. This is a huge victory for your citizens and you, who have some assurances that if [Batfish Man](https://en.wikipedia.org/wiki/Batfish) shoots up the neighborhood, *someone* will pay for the damages. And that someone isn't the tax-payer! This also benefits the villains' front companies insurance companies who certainly will give massive contributions to your reelection campaign coffers and/or your completely legal [PACs](https://en.wikipedia.org/wiki/Political_action_committee). Heck, you've created a whole new high-profit industry: *hero bonds*. And the whole thing fits nicely into existing frameworks for how to license potentially harmful groups. So you've also made it easier to defend the new requirements from any legal efforts to block these rules. Because whomever pays SpiderMonkey-Man's legal fees can afford to attack your rules, so it needs a solid legal basis. (It's also an expense that keeps the riff-raff out of the hero business.) Maybe you'll end up with corporate sponsors to help offset the fees, like Captain Amazing in [Mystery Men](https://en.wikipedia.org/wiki/Mystery_Men)? If so, there might be further kick-backs you can personally profit from and/or ways the villains can take advantage of the situation. Imagine if Lexicon Lutherson used his vast dictionary business to fund Superduper-Man's hero bonds? What kind of hilarity would that cause? [Answer] I like the answer that uses damages as the basis for taxing. I'd like to take that further. Insist that all actions Superheros perform be subject to liability laws including civil suits. If a villain or bystander is injured directly or through loss of income, they are free to sue the superhero for those losses. They should also be able to get multiple damages if they can show carelessness or malicious use. If the superhero is unable to pay directly, they must use their powers exclusively to work off the debt. That approach highlights the damaging aspects of superheros and can be an effective negative publicity campaign in itself. [Answer] ## Do what countries with very restrictive gun laws already do to citizens who apply for firearm permits. You said there is already a registration process for superheroes in place. Add a series of medical examinations to it, and of course the applicants have to pay for it, and of course these examinations can only be done at the medical facility selected by the government (so the price can be arbitrarily set, without having competition). Add a long waiting period. The waiting period can be shortened by paying a fee. Increase the types of tests required drastically. You want to make sure they are not a danger to themselves and society, right? And of course, these tests have to be retaken every year. Also make them take regular courses in medical, firefighter etc, training, and have them pay for these courses. [Answer] Have a vigilante license that is costly, and has to be renewed every month or so. ]

[Question] [ So I had a funny idea, somewhat based off the cow in the *Restaurant at the End of the Universe* in the *Hitchhikers Guide*. You know the one—that wants to be eaten and whose only purpose in life is to be consumed. Plants already have a variety of similar survival solutions: to my knowledge most fruit is designed to be eaten so that the animals can then spread the seeds of the plant in their feces. However, would this be possible with an animal? What benefit could an animal gain by being delicious and seeking out being eaten by other animals? Is there a way such an animal could use its own death to aid in reproduction? Ideally the animal shouldn't kill the creature that consumes it (so no larvae inside the parent that eat their way out of the creature that ate their mother, for example) and the relationship / interaction should be mutually beneficial for both parties. [Answer] That's not too hard. There are plenty of real-life animals that want to be eaten. They're either parasites, or the hosts of parasites, whose behavior is modified by the parasite that they carry. Of course, since you want the interaction to be mutually beneficial, your animals won't *technically* be parasites, but their ancestors could have been. It's also fairly common for parasites to evolve into mutualistic relationships with their hosts. The reason for a parasite to want to be eaten is simple enough: it needs to get inside another animal in order to continue its life cycle, whether that's to trigger a metamorphosis of some sort, or because it's eggs can only hatch in a certain kind of host, or whatever. The trickier part is figuring out how eating the parasite turns into a benefit for the eater. The obvious one is that eating the former-parasite provides the same benefits that eating usually provides--energy and nutrients--in sufficient degree to offset whatever resources the now-symbiote drains from the host. Perhaps, for example, there is a creature with a multi-stage life cycle with morphology alternating each generation, such that one generation requires a certain other animal (or class of animal) as host, and the alternating generation is free living. Now, just make the free-living morph capable of eating stuff that its host animal can't natively digest, and the host/predator species will be able to expand its nutrient base by eating the free-living generation in exchange for hosting its eggs. This is basically the same kind of relationship that humans have with goats: goats turn unfarmable land into meat and milk for humans, and in exchange for letting us eat them, we breed and take care of the goats. Pigs are in a similar situation--they turn *garbage* into meat, and we help them reproduce in exchange. Another option might be starting with a mind-altering parasite, like, e.g., toxoplasma (except an animal version of it--perhaps something like an intestinal worm that has similar psychopharmacological effects as the real-world protist), and figuring out a way that its psychological effects could become beneficial. This could be completely accidental; for example, the aforementioned toxoplasma causes rats to become unafraid of cats, so that the cats will eat them, because it needs to live in cats to reproduce; in humans, it (allegedly) causes the host to become more fond of cats as well... even though cats don't typically eat humans, so its a dead-end for the parasite! Although toxoplasmosis can also cause psychological illness, one could argue that making humans fonder of cats is actually beneficial, as keeping cats around means that the cats eat rats, which cuts down on disease transmission. Maybe if more Europeans had toxoplasmosis, we would've avoided the Black Plague! Make your fictional parasite capable of reproducing in its accidental host, and you have a mutually beneficial relationship there. Taking a more direct approach, it's possible that a parasite ends up having incidental effects on an accidental host (not the one that it originally evolved to control) that induce immediately beneficial behaviors. Just off the top of my head, it's not hard to imagine a parasite that, e.g., induces an attraction to water and bathing (because it wants to be spread through water), which directly results in improved hygiene for the host. It is also possible that a host animal evolves over time to accomodate for the effects of carrying a parasite, such that *removing* the parasite actually results in pathological conditions. If, for example, the parasite is psychoactive, and the host evolves to adjust its production of neurotransmitters to function normally when under the influence of the parasite, then removing the parasite will result in abnormal function in the modern host. At that point, the former parasite is really acting as a mutualistic symbiote, helping to maintain the hosts neural function. One could argue that humans already have this sort of relationship with a lot of common microbes--lack of exposure to common microbial infections results in deficient immune function. Parasites-turned-symbiotes could also produce vitamins, useful toxins which are stockpiled by the host and used against other animals, etc. You may have noticed that of the behavior-modification examples I came up with essentially come down to improving competition against *other* parasites (diseases). That's accidental (I'm sure with sufficient thought one could come up with positive behavior modifications that are also useful for a parasite, and don't have to do with parasitic competition), but that idea can be exploited more directly: perhaps the parasite is good enough at fighting off competing infections that dealing with that *one* parasite is a better idea for the host than leaving itself open to a wide variety of other infections. This, of course, can easily be combined with evolution through tolerance to dependence on the parasite for normal function. Note that humans also sort of already have this relationship with a lot of gut bacteria! If they get into the wrong places, it's really bad, but we like having them in our intestines because they keep the *other* baddies out. Ability to carry a parasite could also be subject to sexual selection, in which case the parasite that makes an animal want to get eaten could benefit its host enormously by increasing its reproductive prospects before it gets eaten. If the parasite has obvious behavioral or physical effects, those may end up acting like a peacock's tail; a peacock's tail is a horrendously expensive feature that severely reduced the bird's ability to avoid predators, and its only purpose is to show off to peahens that *I'm so incredibly awesome that I can get away with growing this impractical thing **and still be alive***. Your animal would be showing off a similar attitude: *I'm so incredibly awesome I can survive and thrive **despite obviously carrying this parasite***. Now, that's something of an unstable situation because there would be pressure to evolve the expression of similar features *without* having to actually carry the parasite (essentially lying about fitness to get more / better mates), but it could become a stable mutualism if combined with evolution towards accommodation of and dependence on the parasite's presence, for any of the reasons described above. Then, you could end up with a "parasite" that wants its host to get eaten so it can complete its life cycle, and a host animal that wants to get eaten (*after* having lots of babies) because it wants its parasite to complete its life cycle--because if the parasite goes extinct, so will the host species that has come to depend on it! (For vitamins or neural function or parasitic competition or whatever combination of things.) So, there you go. Just try to think of all the ways that parasites can evolve into mutualistic symbiotes. Then, start with an animal parasite that needs to be eaten to complete its lifecycle, but does not kill the host, or a microbial parasite that makes its host animal want to be eaten, and evolve that into either an animal symbiote that wants to be eaten, or an animal that wants to be eaten as a side-effect of carrying a microbe (or whatever), but benefits sufficiently from its symbiote before that happens. [Answer] Plants naturally produce edible fruit because they can't move, and animals can - animals eat the fruit, move the seeds, then defecate them out. The seeds then grow in a potentially uncolonised location (with bonus fertiliser). ## Egg fruit You can easily imagine a sessile animal (like a sea anemone) that uses the same process. It lays eggs whose embryo is safely wrapped in a tough lining, but surrounded by something nutritious and digestible - either fleshy (like a placenta) or like a classic yolk. A highly mobile animal eats the eggs, and deposits the young a long way away. You *did* specifically want the adult to die - in that case the adult itself becomes extra nutritious when its young (kept inside) are ready. Bonus points if the adult is normally poisonous or well armoured, to prevent itself being eaten too early. ## Migrants The adult doesn't even have to be stationary. Imagine an extreme long-range migrant, like the monarch butterfly or an eel. Perhaps the adults travel a huge distance to the breeding grounds, but the season is too short for the young to develop enough to make the return journey. They therefore hitch-hike inside a larger animal that *does* travel in that direction. This could be non-lethal: Logan R. Kearsley has given lots of ways for that to benefit the host. But we can come up with lethal methods too. Perhaps only a fraction of the young survive the host's digestive juices. Enough survive to propagate the species, but enough die (giving nutrition to the host) that they are still worth taking the gamble on eating. Perhaps the host species does exactly the same migration trick, but in the opposite direction... ## Cannibalism IndigoFenix and Denis de Bernardy have already mentioned cannibal spiders, but we can extrapolate further by looking at colonies. The (real) [honey pot ant](https://en.wikipedia.org/wiki/Honeypot_ant) has a specialised worker caste that swells with food during good times, so that the colony can feed off them during famines. They only regurgitate the food, without dying, but a lethal version is just as feasible. Perhaps this isn't even to prevent famine. Imagine a eusocial creature that practices mass spawning - to avoid predators, or to make use of sudden bounties of food. During most of the year, the colony collects food as normal, and the queen produces just a few young that are immediately fattened-up by other workers. When breeding season arrives, she devours them to fuel a rapid mass pregnancy or clutch of eggs, making young that *are* intended to survive. ## Mutual destruction You specifically didn't want parasites that eat their way out of the host. But what if the *host* also wants to be eaten... In a world without flowering plants, there are no fruit. But when the parasite lays eggs in a plant, the larvae produce plant hormones that force the plant to grow a fleshy, fruit-like [gall](https://en.wikipedia.org/wiki/Gall) around them. The gall is toxic except to one species or group of host creatures. They gorge on the fruit-galls to gain the nutrients they need to reproduce, and they do so. But the cost is that the parent host is infected by the parasite. It will be eaten alive, eventually. But the parasite is slow, and the host makes young rapidly. The next host generation is safe and sound before their mother is devoured. Admittedly an individual host may not "want" to be eaten - not even by the standards of natural selection. But the *species* cannot survive without the food made by the parasites, and so the hosts must continue to sacrifice themselves. ## Defense via Sacrifice This idea works best for large herd prey animals that are themselves dangerous to their predators, like wildebeest or sauropods.  We combine the familiar concept that predators take elderly or infirm creatures from the herd, and the [decoy](https://en.wikipedia.org/wiki/Distraction_display) behaviour of some animals. When a herd is pursued by predators, the oldest or illest member may naturally fall behind.  At some point, it gives up entirely, and turns to walk towards the chasers.  It makes a special call that promises that it won't resist, and the predators run straight towards it and devour it.  If evolution is kind, the creature's pain nerves shut down when it breaks from the herd; but when has evolution ever been kind? This strategy is superior to the real-world case where creatures do not *deliberately* leave the herd, because the pursuit is called off quickly when the individual makes its surrender.  This reduces the herd's energy expenditure and risk of injury.  It is also better than using a fit decoy who survives the encounter, as long as elderly animals are expendable.  This is because the predators *do* get fed, and thus don't hunt again for a while, allowing the herd time to move far away. [Answer] Truth is stranger than fiction sometimes: <https://www.nature.com/news/parasite-makes-mice-lose-fear-of-cats-permanently-1.13777> > > *Toxoplasma gondii* is known to remove rodents’ innate fear of cats. [...] its effects on rodents are unique; most flee cat odour, but infected ones are mildly attracted to it. This is thought to be an evolutionary adaptation to help the parasite complete its life cycle: *Toxoplasma* can sexually reproduce only in the cat gut, and for it to get there, the pathogen's rodent host must be eaten. > > > Voila! Such an animal already exists (sort of). Essentially you need an animal that can only reproduce via consummation by a predator species, so at some point in its life cycle it basically goes "Eat me!" And the cat thinks itself so smug at the easy catch. [Answer] It's probably not that difficult, actually. Desire to live is not intrinsic to life or even intelligence. The reason most creatures fight to survive is because that instinct allowed its ancestors to reproduce and so that instinct endured. There are organisms that die in the process of reproduction - octopus, drone bees, and mites, for instance. Some species of spiders will actively climb into the mouths of their mates, because giving an extra meal to the production of their children allows their genes to spread more effectively. All you need to do to make a species that wants to be eaten is to selectively breed them for it. Start with a cow that is less frightened of the death of other cows than usual, and breed it. Gradually focus on this behavior until you get an animal that is attracted to places where other cows have been slaughtered, and finally one who is specifically attracted to slaughterers and submits itself to be slaughtered. If you keep breeding increasingly suicidal cows, eventually you'll get a breed of suicidal cows. Since this suicidal behavior is what allows it to reproduce successfully, it is no different than a spider that jumps into its mate's mouth - its reproductive instinct has become linked with an instinct to get eaten by another creature. Of course, few people in the meat industry are going to bother with this, and with more efficient lab-grown meat likely in the near future it hardly seems worthwhile, but it *could* be done. EDIT: For a naturally evolving creature, the most logical course is that being eaten should somehow promote the organism's reproductive cycle. Most animals that seek to be eaten in this manner are parasites, which isn't what you're looking for - and for that matter, if the creature doesn't die in the process, the eater is unlikely to get much benefit out of eating them. What I would suggest is a kind of "animal fruit" - a slow-moving, fatty creature with a sack full of small, hard eggs. When the creature is eaten, its body is digested but the eggs pass through the digestive tract and are dispersed long distances. Perhaps a formerly parasitic species (like a tapeworm) that, faced with an increasingly hard-to-fight immune system, started feeding more *before* being eaten while shortening its intestinal parasite phase (in order to reduce the time it would have to resist the immune system) and eventually ditched the parasite phase entirely. [Answer] ### Some spider females eat the male after they're done copulating There are known cases of [spider cannibalism](https://en.wikipedia.org/wiki/Spider_cannibalism) already, with the female eating the male (a good source of protein) after mating. There also are a handful of examples of spider species that exhibit sacrificial mothers, that die while guarding their eggs, allowing their offspring to eat them upon hatching. [Answer] "Want" is a difficult trick, because to *want* to be eaten requires a level of intelligence. Diseases, parasites and parasitic fungus can change brain behavior, which can result in getting eaten, but you can't really say the animal wants to be eaten as such. *Why*, on the other hand, is easy. Life is about survival. If you can ensure the survival of your offspring / species by being eaten, then a species will do that. Just look at domestication. We eat beef, chicken, lamb, fish and pork and none of these species are close to extinction--in fact, these species are some of the most numerous animals found on the planet. We protect and care for animals, which allows them to breed and breed and in return we eat some of them. We also breed docility into the animals, so whilst they might not want to be eaten as such, the animal is fairly dumb and oblivious to the oncoming death as much as possible. This is a desirable characteristic, as stress affects the meat. It would be possible to breed an animal that wants to be eaten, but it would be counterproductive to current breeding characteristics. You would need to increase intelligence as well as a self-destructive trait/mental illness. There are people in the world already that [want to be eaten](https://www.theguardian.com/world/2003/dec/04/germany.lukeharding). [Answer] I can imagine a herd species that evolved a sacrificial caste. The species routinely needs to run and flee from much faster and deadlier but smaller predators. Some members of the species are known to grow much larger and plumper than others, and maturity is identified when the fight-or-flight response is replaced with an instinct to lure predators away from the rest of the herd and allow itself to be consumed, ensuring the survival of the herd at the cost of the life of the sacrifice. These creatures won't seek out danger, but will also not flee from any predator that appears, especially if there is a friendly herd nearby to distract the predator from. Of course, once an intelligent species finds them, they selective-breed the heck out of the sacrificial caste, to the point that the entire herd are members of the sacrificial caste. Most members of the intelligent species might not even remain aware that the original members of this species had runners or other castes. I've extrapolated this idea from the concept of mother animals leading predators away from their young and sacrificing themselves to protect them, though a very quick Google search didn't immediately reveal to me which animals it was that I'd heard have been observed with this behavior. [Answer] Draco18s's answer is very good! But in fact, I found something even more strange on Quora: > > Some baby birds instinctively try to insert their beaks into the mouth of their mother so their mother can regurgitate food. Sometimes this is done by simply looking for a distinctive color, the color of the inside of the mouth of the mother bird, usually reddish or pinkish. In some birds the instinct is triggered by a spot of color on the outside of the beak. Tapping the beak makes the mother open her mouth so she can regurgitate food. It can in some cases be triggered by a painted white piece of plywood with a spot of the appropriate color and approximately the same size and shape. In a small animal, reproducing this instinct and coding it to the human mouth/throat means it would literally jump into a human's open mouth due to the compulsion written in its genes. A little gross and unsanitary for humans but maybe usable for some domestic animals like dogs or cats. But again, probably not what you are asking since there is no desire to be eaten per se, just a desire to go to something that looks like a mouth. > > > [Quora Site](https://www.quora.com/Is-it-possible-to-breed-an-animal-that-wants-to-be-eaten) This could count as "purposely becoming the food of another animal," although it doesn't account for the "desire part." Just an interesting paragraph :P [Answer] In a magical world (or a world with magic-like effects) perhaps there's a ["Inverse Ninja Law"](http://cool.wikia.com/wiki/Inverse_ninja_law) in effect. In this world, the "magical" power of a particular species is constant BUT the with normal, exponential biological growth the "magic" gets spread thinner and thinner among the living individuals. The individual creature, having had children, has a biological imperative to give advantage to its offspring. It goes out into the world to be eaten so that it's magical essence can be distributed among its children. Why doesn't it just commit suicide? Because of magical reasons. [Answer] I think even in case of plants, the mutually beneficial aspect comes from a renewable feature of the plant. Plants produce tannin to prevent animals from eating leaves and other important parts of the plant. A plant is at an overwhelming disadvantage when it comes to mobility. So, it has to make a stronger compromise compared to animals which have mobility; which is why it gives out nutritious and sugar-filled fruits. In the animal kingdom, human beings don't really have any outstanding ability to help other semi-intelligent animals, except ensuring they're not wiped out. In fact most animals outperform human beings in one or two aspects. For example, a cheetah can run faster than humans, and elephants are stronger. A cow can survive on relatively less-nutritious grass (and provide milk which is nutritious for humans; which is also one of the reasons why cows were domesticated) in non-forest ecosystems. So, I'd guess as far as the tasks about which animals care, which is basic survival and reproduction, unless you're able to provide them some fundamentally awesome things, I doubt you could make them give you anything. Also, even then, it wouldn't give its life unless it's mentally dysfunctional in some way like the bacteria example by @Draco18s. [Answer] ## Larval form eats parasites and produces antibiotics Creature keeps its baby larvae embedded in very tasty tentacles that are intended to be eaten and the creature can regrow. Sometimes predators get greedy and eat more than the tentacles, so parents can sometimes die. The tentacles provide nourishment to the creature eating them while the creature eating them provide a place for the larvae to grow. Once eaten the larvae consume resources from their host much like a parasite till they become big enough and then get pooped out. However, unlike a parasite the larvae do earn their keep while they are in the host. Not only do they feed on parasites that may be present in the digestive system, they also produce antibiotics. The antibiotics may have originally been intended to kill bacteria in the digestive track so that the larvae could gain the nutrition all for themselves, but over time the bacteria in the digestive track built up a tolerance to it. So if the creature has an infection or has a parasite in them, then eating your tasty animal can result in them recovering from it. It may result in some unpleasant side affects, such as fatigue and unusual looking stool, but it would be worth it. [Answer] It’s very easy to make animals illogically want to be eaten. But can you make them logically want to be eaten? Teach them economics 101: people will only feed cows or allow them to graze if they’re eaten - no-one wants to keep them as pets or see them in a zoo, and cows’ milk is regarded as vastly inferior to mare’s milk. The food market is ultra-competitive - sure beef is popular now, but who knows if it will be next year? An adult cow that has had a couple of offspring has two choices: Live for a couple more years and then be butchered, or be butchered now. If they choose the former, sure they might get a few more years. But someone might eat that beef, decide that beef tastes bad, and then the offspring are killed off while they’re still young because no-one wants beef. Or you can choose to be butchered while you’re still in your prime, keep up the popularity of beef and give your children a future. As a parent, which would you choose? [Answer] ***Why*** There could be many reasons.. Parasites, proliferation and for me mainly safety. ***Both benefitial*** There exists some fishes that keep whales clean of the dead tissue and some parasites ( <https://en.wikipedia.org/wiki/Cleaner_fish> ).. It's mutually benefitial, so when it's possible outside, why not inside? It could be safe place for cleaners and they would make (life easier/help to survive) for the bigger animal.. ***One side benefitial*** Other way could be for small/medium sized animals it could be just for safety reasons.. Inside the other animal they could be safe. Further more their offsprings would have better chance of surviving the vulnerability of their childhood against outside prey. And when older they would get out inside feces. So benefitial for one side, the other side would be just carier. [Answer] [Periodical Cicadas](https://en.wikipedia.org/wiki/Periodical_cicadas) and their [predator satiation](https://en.wikipedia.org/wiki/Predator_satiation) adaptation can be considered real-word example of this behavior. These insects spend the majority of their lives underground as nymphs, but emerge in massive numbers as adults during their short reproductive period and act as easy prey. Normally (as nymphs), there is no benefit to being eaten. However, during the short mating period, the adults emerge in billions, flooding and blanketing the environment. They are nutritious, slow, clumsy and easy to catch, almost offering themselves up to be gorged upon by their predators. Why? By achieving over-saturation in a local environment, they can feed all of their predators so that the remaining adults can breed undisturbed. [Answer] I think a symbiotic relationship could benefit both. Look at the babelfish - it benefits by having something to "eat" and the human benefits from the translation. Another example is Dax (that symbiont from Deep Space Nine) - its intelligent but needs a host for motion and sensors and the host gets the memories of all the previous hosts carried by the symbiont. The only difference is that we want the symbiont to be eaten so it only works if the one that gets eaten stays alive which implies a small creature. So my idea: You eat this small creature and it gets some benefits: it gets to travel over greater distances than it can accomplish by itself, food is delivered to it, it has somewhere safe away from its predators, and/or it has somewhere warm/cold to stay when temperatures are more extreme than it can handle, plus maybe it gets to tap into the nervous system or something so it can communicate to the host. Why? Well, maybe food is scarce and a small creature can't cover enough distance by itself to get enough food to survive. Maybe it needs somewhere safe to hibernate in the winter - it could leave when it wakes up. Maybe it's just lonely and needs intelligent communication with the host. The host would get benefits too: it could get disease/infection protection even if the creature was hibernating but also if the creature can tap into the nervous system or something and they can communicate then maybe the brains can work together on solving problems - then the host gets much more processing speed or a different kind of processing or even just memories of previous hosts which would help make decisions. ]

[Question] [ *Dear NSA intern reading this post, I don't actually intend to start a coup* *Dear @DasBeasto - we'll be the judge of that. - NSA* Consider a country pretty much exactly like modern day America. The government (allegedly?) has their nose in everything that happens online. However, online communication is a great way to get your voice heard and reach millions of people. So going online and recruiting people to participate in your coup, planning and staging, and even initiating the attack would be perfectly facilitated by an online interface...if it weren't for those pesky government snoops that would immediately shut it down and arrest all those involved. So my questions is what would be the best was to use an online interface to facilitate your coup. Would you use a VPN and only allow access to people you personally screen? Would you hide on a hard to reach page on the deep web like the silk road? How could you make sure your coup is successful without the government interfering? **Stipulations:** * Lets assume 70% of the country agrees with you and wouldn't rat you out/might participate, 30% disagree with your stance and would rat you out to the government if they discover your plans. * You need your message to reach many people, your plan isn't something a couple thousand people could carry out. * I want to use the term "online" loosely, any other high-tech communications such as RFID's, QR codes, or SMS Texts can be used if it fits better, even if they don't connect to the internet. * If you use encryption by some means it is ok if the government find the communication as long as they can't decipher the plans or stop the communication. * This has to be technology the average person could figure out/be taught, remember we need many many people to be able to participate. * I'm picturing a standard brute force coup, but would be interested in others The best answer will give a way for this way of communication to spread to as many people as possible as quickly as possible without the government or those who don't agree with your ideals figuring out the plan. [Answer] I actually work in Cyber Security, so here's my tips for your uprising and/or cult (hey, I won't judge!). This is incredibly yawn-worthy, but as accurate as possible. You could absolutely go deeper, and more extreme than I'm listing, but this is trying to strike a balance between security and minimizing infrastructure. I'm also assuming that the Internet is available, just being monitored closely. **So What do we do?** So we want to avoid Big Brother digitally. Networked (specifically the Internet) is such the defacto means of digitally communicating with large groups of people, so we'll assume that it's your standard. You'll have two concerns of communication: * Peer-to-peer communication (used to communicate with those already in the know) * Broadcast-style communication (used to speak to a wide audience). The first rule of security is that **security is a two-person operation.** If either end--the receiver or transmitter--isn't secure, the entirety of the communication isn't secure. Technically the transmission is also a concern, but we can largely ignore that (and hope for the best) if we can ensure that both ends are locked tight. The second rule of security is that **you're never secure. Even if you think you are, you're not.** Cyber Security is about three things: * Ensuring Confidentiality (Only those who should see it, see it, or should access it, access it) * Ensuring Integrity (The information remains unchanged) * Ensuring Availability (The information remains accessible) There is no way known to man to guarantee all three. Anything and everything you're doing is mitigating risk, and that's it. People joke that you can unplug a computer to secure it, but even if you have perfect physical security for the computer, you've just made the computer unavailable, invalidating the last one. What good is a computer that's turned off? Or they joke you can permanently air-gap it. The machine is still at risk to anyone who touches it, and it probably isn't available. Certainly it isn't available for communicating under Big Brother's nose. The third rule of security is that **security should be layered** and **there is, and never will be, one golden solution to security.** **Let's Get Down To the Brass Tacks** Okay, so there are a number of steps you can take. Again, you can go farther than this (there's hundreds upon hundreds of page books on security just for introductory certifications), but we're going to hit some key highlights and points of interest. I'm breaking it down into A) Security Boxes, B) The User, and C) Communication **Securing Boxes** First of all, we'll need to secure the machines that the person uses to access the Internet. * *Secure Operating System*: We want an operating system that offers security at rest (encryption when turned off) and security at runtime. Open Source software (where the source code is published for anyone to see) typically is the most secure since it's had the most people possible examining it for holes, and third parties can independently examine it. Let's go with BlackArch as a base. Packages (bits of software) will have to be installed to make it user friendly for the masses, so somebody leading this uprising (or their tech guy) will need to examine each patch to ensure that they're secure. * *Encrypt All Drives*: Encrypt. Everything. If any computer is powered off, or drive unplugged from a computer it should be encrypted. *It should be noted that encryption only slows a sufficiently skilled, funded, and motivated attacker down, and does not stop them.* It's know that the government had issues cracking the iOS encryption, but eventually (through a third party) they got through. * *Use a Secure Browser*: Tor is the classic example. Your traffic is routed through random nodes to help hide it, and Tor comes with some other tools to help you hide. This too is not perfect. * *Never Download and Install Software*: Any software you install on a machine, including browser plugins, are potential security exploits waiting to happen, or worse, were produced by Big Brother. You only use open source software, only use software carefully approved by your tech group, and avoid downloading software (even if approved) as much as possible to avoid spoofing. * *Always Verify Software With A Hash*: This is a process of running the bits of software through some math and producing a number, the hash. Change even a single bit in a piece of software and the number (the hash) changes dramatically. It's a fantastic way to verify nobody's messing with the software you install. **The User** The biggest (bar no second) weakness in security is, sadly, the user. Users do stupid stuff. This is not hating on anyone, this is just a reality those in Cyber Security face. Your organization will need to address this (good luck!). * *All Users Use Unique Passwords*: Passwords should never, ever be intentionally shared or duplicated. Ever. * *Use Smart Passwords*: You can look for yourself at [the type of passwords people use.](http://www.computerworld.com/article/3024404/security/worst-most-common-passwords-for-the-last-5-years.html) You can also look for yourself at how [complex passwords make passwords more secure.](https://password.kaspersky.com/) (NOTE: DO NOT ENTER YOUR REAL PASSWORD IN THERE TO TEST IT.) * *Your Passwords Are Only Secure As Access To Them Are*: Currently we can't read minds. That technology doesn't exist. Anything written down can easily be acquired. No passwords on post-it notes. * *Your Users Should Be Educated On Your Procedures*: In the modern world, one of the best ways to compromise a user, compromise a system, compromise a network, etc, is through phishing. This is trying to trick a user into giving up access or giving up their password. A phone call claiming to be the help desk, an email that says "click here to reset your password," a supposed other rebel asking for just a bit of quick access to your box... Your users need to know that they have to be draconian and have to be educated enough to know your procedures so they'll know if something is going outside your procedures. They can't be duped by a phone call if they know (and accept) that no phone calls will ask for their password. * *Your Users Should Be Educated On Security*: Quite simply, the users will use security tools more effectively. * *Need To Know, Need To Access*: Users should only know what they need to know, only have access to what they need to access. When your users mess up (and you will have many, many mess ups with 70% of the population needing to be in on the loop), you minimize how compromised your systems and information are. **Communication** * *Always Use HTTPS For Communication*: Other protocols can advertise your location. Limit yourself to only handpicked, trusted certification. These certifications should be authorized by your leadership. We don't want the government spoofing certificates to lead you to an incorrect site. * *Connect Without Pattern*: Aim to connect at different spots, randomly. Don't connect for long periods. Take advantage of public WiFi spots. * *Connect Anonymously*: Use proxies, and host some servers (distributively, don't put all of your eggs in one basket) overseas. This will slow connections, but will disguise who the Internet requests are coming from. This is *not* perfect and *can* be gotten around. * *Transfer Information Discretely*: There's a few ways of doing this, but the classic example is [steganography](http://This_information_is_Hidden/It_is_not_quite_stenography_but_it_IS_hidden_in_plain_sight). Basically you take a known file (say a song or picture) and alter it slightly. In the case of a picture you're altering the pixels' colors *just slightly* so it still appears like a normal picture. However once downloaded and compared to the original, you can find the hidden message. This can all be 100% automated, but it's still a challenge to secretly distribute the original image. *This method would be useful to broadcasting communication, as it can be publicly hosted on a website without suspicion.* ...And there we go. Follow these tips and you too could mitigate risk! ...Not very sexy, is it? [Answer] I disagree with the premise. I mean, if 70% of the people agrees with you, create a political party. Look at the approval rating of the current two candidates and compare it to your 70%... Now, let's assume you no longer can form a political party or somewhat it feels like a lot of work to do. Well... just join a few friends, go to a very crowded place, take out some signs and begin a protest. With support levels of 70% we are not talking about a coup, not even about a revolution, it would just be a takeover. Typically, coups are planned by a small cadre of very influential people (military, bussiness, even the judiciary...) and so they need to remain secret to act together. Revolutions (those that succeed) rely more in popular support, but still only a minority of the people is active and so need preparation (in secret) to succeed. The 70% makes your proposal neither of those. [Answer] A coup has a very specific meaning, which is a small cabal of plotters who generally have access to the levers of power (Government ministers,, army officers etc.) overthrow the existing government and install themselves. The role of the people, if any, is to acquiesce to the change in government without too much of a fuss. The replacement of the Egyptian "Muslim Brotherhood" led government by the Army in the very recent past is an example of a modern coup. What you are asking for specifically is a rebellion or a revolution (which are similar and related, but not the same). A rebellion occurs when a group, such as an oppressed minority or other grouping with a grievance, feels they have exhausted peaceful means to change their situation and have no other alternative but to throw off the oppressive government by force. The American Civil War can be viewed through this lens; the Southern States were steadily losing economic and political influence to the industrial Northern States, and were no longer able to accept restrictions on the issue of Slavery in particular (this came to a head when deciding if new territories admitted to the Union were going to be "slave" or "free"). While slavery was a hot button issue, the Southern States were also becoming less relevant in other political and economic areas, and resented their diminishing status. Rebelling against the Union was considered their "out". A Revolution, on the other hand, is generally triggered and carried out by the Middle Class when they feel their property and political and economic rights are under threat by the aristocracy (or ruling party) or by the poor. They fight to keep what is theirs, and to reorder the political structures so their property and position is no longer under threat. The French and American revolutions are examples of this kind (see [The Coming of the French Revolution](http://rads.stackoverflow.com/amzn/click/B004HZFGT4) for a detailed study). WRT the internet and electronic communications in general, a true coup has a high chance of success since the ministers or officers can access secure systems, in addition to meeting face to face. Most secure systems are "air gapped" and have no connection to the outside world (which is why the Clinton email server is such a security breach, all those classified emails had to have been downloaded from secure servers first and then physically transferred to the unsecured server), so monitoring the Internet will not reveal anything. Now security service es should also be monitoring the internal traffic as well, but here the ministers or military personnel can always include their *own* security services, and use them to block, misdirect or obscure what they are doing from a rival service like the police or NSA. Rebellions and revolutions have been conducted over the internet (the Iranian Green Revolution and the Arab Spring are recent examples), but this is fraught with difficulties. The security services can and do read internet traffic, and can usually crack improvised codes. The Egyptian Police in particular used FaceBook "spoofing" to lure protesters into areas where the police were waiting to arrest them. In the case of the Arab Spring, the long term resentments and frustrations simply provided fuel that did not need the internet to get people going, and the police and security services were eventually outnumbered and overwhelmed. The fate of the 2009 Green revolution demonstrates that the Internet is not a substitute for traditional tools. Lacking outside support or even a safe and secure area to rest, train and equip themselves, the Green Revolution fizzled out under the relentless hounding of the Iranian security services. As an aside, you may remember or look up video taken during the uprising; many of the signs were in English as an appeal to the US and the West to provide moral or physical support to the revolutionaries, but President Obama chose to ignore and turn his back on them, guaranteeing their eventual failure. Another example of how to raise a rebellion or revolution even under the occupation of a much more militarily strong power is to look at the actions of the [First Intifada](https://infogalactic.com/info/First_Intifada), as outlined in the book "[The Sling and the Stone](http://rads.stackoverflow.com/amzn/click/0760324077)". This 4GW action used paper communications like handbills and word of mouth to spread information and instructions, and chose to forbid armed resistance to the Israeli army rather than fighting with guns and rockets to attack them through PSYOPS and the international press. Since the IDF chose not to physically occupy the West Bank (military actions were more similar to a series of raids, and the force to space ratio made full time occupation impossible anyway), there was a "secure" area to operate out of, and of course the Arab Gulf States provided money and other help as well, so they had all the classic tools needed for a successful rebellion. [Answer] Don't plot, don't coordinate, start a movement. One solution is hypotheticals. Have people post plans in a general or hypothetical way to mass consumption sites, this gives a possible legal out. (more on that after my short prison stay) You can spread plans and variations on plans so even though they are reading right along with your people there is some chance of success. Another is do something normalish. At my high school the admins banned green shirts, the gang didn't care they switched to bandanas, then socks, then belts. The hall monitor had no time to hassle people doing slightly naughty stuff behind the gym because they had to bother with silly stuff in classrooms. Choose your level of involvement. If the cops are chasing some one with a gun, they probably won't bother with you spraypainting. Hardcores might get dead, but moderates get bolder. These plans should be simple to implement, not dependent on a lot of coordination or require too much set up. Consider dressing up like a clown and doing something silly. This show support for your cause. Yay us. Nobody gets charged with anything. Now what if some of you go a little farther, and a little farther, and a little farther. Probably ends with blood in the streets, but that's kinda what you are asking for. Also science. Everyone should learn basic chemistry and physics. "Give a man some bleach and he'll clean a house, teach a man to make bleach and he'll burn it down" [geohashing](http://wiki.xkcd.com/geohashing/Main_Page) is a method of creating difficult to predict locations, if you modify it to have a time and be less vulnerable to manipulation by the powers that be it could offer a way to arrange mass meetings without giving opposition time to prepare. [Answer] *Lets assume 70% of the country agrees with you and wouldn't rat you out/might participate, 30% disagree with your stance and would rat you out to the government if they discover your plans.* This raises three questions in my opinion. 1) When is the next election ? If the next election is coming soon, you can make an electoral coup and win the elections with a clean sweep. 2) Are 70% of the government employees agreeing with you ? If they do, you will have a number of moles inside the government which would help you greatly. If you have a mole inside, it sounds reasonable to coordinate through an unmonitored website and an unmonitored radio channel. 3) Are 70% of the military agreeing with you ? If they do, the government has technically no way of enforcing its authority in an open conflict, thus there would be no need to actually hide from the government. If none of these questions lead to resolution, my best call would be hire extremely large groups of hackers to get the government's systems down for a while, and coordinate through something as simple as Facebook. Word-of-mouth will spread within minutes, and with the government's technical network down, their response would be too slow to prepare an serious answer. The government and people who disagree with you will learn about the coup, but will not be able to mount an actual retaliation. [Answer] 70% support and a country like America? "On January 20 at the swearing in we will retake our nation. March on Washington **unarmed**, our sheer numbers will prevent us from being stopped." Get the word out enough. Remember, even in China the government had a hard time finding troops willing to take up arms against their own population. With 70% support the police and military will not be able to stop sheer numbers--an awful lot of their members will be on your side. [Answer] Given that the question states the country is "like America" I'm assuming that freedom of speech is a thing. Thus regardless of how many people support you, the best way to 'stage a coup' isnt to hide at all. Get as much attention as possible. Delegitimize any sources of actual fact-sourced information and spread massive campaigns of disinformation through social networks and any other sources that you can convince people to trust instead. The government response doesnt matter because anything they do/say just legitimizes you in the eyes of anyone you've been able to prime with your misinformation. Then win an election. You dont need 70%, or 50%, or even a plurality. You just need a few simple lies that are attractive and easy to understand and enough people to get them viral. [Answer] The thing about high security is that it's suspicious. Fully encrypted drives, secure networking and clandestine communication might keep your data safe, but it's going to pull up a massive red flag for any intelligence agency once the participation reaches critical size. Assuming that you can't just win a Democratic election as many are suggesting (assumption: The Government and ruling body is corrupt and would rig the election), and that you have something approaching Free Speech, then there's a novel approach you could try, and hide in plain sight: 1. Announce the release of a new online game, where America/Your Country is in a state of political flux, and unrest is growing. Choose your side in the most realistic MMORPG ever! 2. Make it as realistic as you can. It's a game, right? You're not doing anything illegal, it's all hypothetical. 3. You now have a dual-use recruitment/scenario platform, where you can test your scenarios to death and identify the people more likely to be sympathetic to your cause - the more realistic you make something, the more likely people are to reflect their real opinions in their in-game choices. 4. Due to "Popular Demand", release a private version of the software, where people can play their own privately networked versions. Now there are hundreds of different versions of this game all over the internet, hiding your "Real" version among the masses of fake ones. What you do from there is up to you, really. You've got a public recruitment platform for testing out new ideas, and a private platform for your scheming. If anyone busts you for anything, you can claim research and development of new scenarios for the game, and that none of it was ever going to be implemented in reality. [Answer] I think Orson Scott Card was onto something when he showed how to do it. With his idea, you wouldn't even need to start with 70% support. If you did, it would make it go that much faster. In *theory*, it would be simple enough to create ONE new political party and then use that party to take over. However, in practice, as others have pointed out, it's difficult to take one new party to the top and beat out the others which are already established. In Card's classic book Ender's Game, while Ender is out in space, training in battle and commander school, his siblings are busy taking over the Earth (this is plausible when you remember that they are just below Ender as the second and third smartest people on Earth). I am describing here the method they used. You go online and create an established presence by posing as two political and philosophical thinkers **with opposing points of view**. This is the important bit and the real genius behind the idea. The first step is to join online communities and begin publishing essays and works of great political influence and philosophy, getting your opposing viewpoints out there bit by bit. It's just about making the fake personalities seem real and publishing paper after paper as these fake personas, to establish your viewpoints in the public sphere of thought. The second step is to build up a large group of followers for each viewpoint. Once this happens, you can work to build up your political clout within those groups, and eventually to begin expanding them. Because there are two opposing parties, they can be used against each other to work their way into common thought. It's like a game of tug of war. You aren't trying to pull with more strength than your opponent, because that's an obvious attack and everyone else will be against you. For an established opponent, you will never win by strength. Pull harder and the opponent will likewise devote more resources to resisting you. Instead, create your own separate game of tug of war to buck the system by going back and forth. You are getting people to move over to your game of tug of war. They think they are on one side of an argument but in reality, they are all under your influence because you created both sides of the argument. So essentially you get 100% support, without anyone but you knowing about it. Once this is established and the two opposing viewpoints wield considerable power and influence, use both together to topple the existing system. Doing this with two opposing viewpoints rather than a single party is the equivalent of cutting down a tree using a back-and-forth double saw rather than just an axe. The former is obviously going to be easier. What is the government going to do? They won't be able to predict a coup until it's too late. They will see two new rising political schools of thought, but won't necessarily be aware (especially if care is taken to post each side's viewpoint from different computers, always anonymously) of the single force behind it, or what that force intends to do with the power it is gaining. The gradual game is the way to do it, and this system Card came up with seems plausible enough. In short, you must build and establish the **system of thought** before it can be transformed into a system of power. Establishing this system of thought is easier when you artificially create two opposing points of view. Government meddling isn't going to be a huge problem because you don't appear to be a single threat, but rather two separate and opposing movements. You don't try anything threatening until after you obtain the power to take over. This may not be as quick as other solutions, but considering a coup is going to take a while no matter how it's done, I think Card's idea would be an effective one. [Answer] This Defcon talk by Chris Rock gives a pretty comprehensive overview: **DEF CON 24 - Chris Rock - How to Overthrow a Government** <https://www.youtube.com/watch?v=qbTPkKB9Ffc> From the description - note you will be learning **"how to architecht a coup"** : > > Chris will walk you through a cyber regime change from start to finish on a real country and show you how to architect a coup achieving the same result as a traditional mercenary operation without any blood spilt. This will include taking ownership of all facets of government including finance, telecommunications, transportation, commercial companies and critical infrastructure such a power, water and oil. You will learn: > > > • Traditional military mercenary coup tactics used by the infamous 32 Battalion in Africa, Executive Order and Sandline that can be directly applied to a cyber mercenary regime change. > > > • How to architect a cyber coup using advisor’s, hackers and the general populace, using misinformation, professional agitators, false information and financing. > > > • How to gather intelligence to analyze a government’s systemic weaknesses on financial, societal values and political climates that is leader or country specific to structure your attack. > > > • How to identify and prioritize government resources, infrastructure and commercial companies and how to use these compromised assets to stage the coup. > > > • Combine physical and digital techniques and have the best of both worlds to own a countries infrastructure. > > > • Hot to manipulate the media using propaganda targeting journalists flawed multiple "source" rules for a story. > > > • The Grand finale of a cyber regime change on a real country from beginning to end using the above techniques with operational footage. Come to this talk and find out how you too can be your own dictator, benevolent or merciless that part is up to you. > > > [Answer] If you have a safe way of broadcasting your message, just do it sort of V for Vendetta style. Kickass torrent website was illegally up long enough so I imagine it probably is possible to have a public website run from a foreign country where you can write whatever you want without the big brother taking it down. Once you have such a website, you can post your provoking messages, plans etc to stir the pot and give a platform to people to discuss. You'll need to do the right SEO and advertising etc to make it known out there. It can look reasonably harmless initially. If 70% of the population agrees then people will start using your platform and eventually everyone would be openly talking about it all. The government can't take your website down and can't arrest its own citizens for online discussions. The whole thing will go on its own without any coordination, secret planning or whatever else, leaders will automatically rise there, you just provide the right provocation at times as needed. Eventually you can even announce a date for something to happen (V for Vendetta style) and observe how government and people react. People will most likely plan it themselves. Given that 70% of the law enforcement force supports you, you have very good chances of succeeding. But the challenges are also very real - 1. Keeping the online platform up. 2. Ensuring it reaches out to at least all of the 70%. 3. Having the political acumen to stir the pot effectively and keep fueling it in the right direction. [Answer] The bottom line is that despite whether you try to screen members privately or allow them to join publicly, the government will get their spies in your ranks without you knowing. Whatever technology you can think of should not be trusted in the slightest if it faces the public. TOR has so many vulnerabilities it's not even funny. The only thing you can do is go under the radar of communications if you want to stay secure. period. **Defense is to slow down and not to solve, so focus on offense**. That means manipulation, destruction, assassination, and arming the people. Also, don't expect the government not to be playing the same game already. Your best bet may to be secure a position of high influence and trust, and then to initiate your attack from within where the government was vulnerable to betrayal. Also consider: 1. making a presence and movement robust enough so that you don't have to hide by tapping in to the basic nature of people 2. continuously securing more and more power and 0Day attacks until after a considerable number of years you are confident that you can drop the government in one fell swoop 3. creating alliances with a large number of other countries for both cyber and military support 4. avoiding the dangers of confrontation entirely by plotting a "silent coup" over a number of years or decades ]

[Question] [ In sci-fi and fantasy artwork, I often see a city built on top of or incorporating waterfalls: [](https://i.stack.imgur.com/4TwVA.jpg) James Gurney's **Dinotopia** (above) is an egregious example with "waterfall towers". When the city is underground, there's often a central waterfall pouring into a lake. And in the film **Logan's Run** (below) they escape the city through a postmodern water sculpture park – it's purpose isn't explained. [](https://i.stack.imgur.com/dNnt3.jpg) ## **Is there a utilitarian excuse for artificial waterfalls in a (mostly) realistic fantasy or sci-fi setting?** I'm looking for plausible infrastructure, sanitation, irrigation, or atmospheric purpose that would justify the expense and maintenance of channeling artificial waterways through a city, or deliberately building a megastructure city on top of natural water channels and cliffs. *A watermill in every home* does not sound like plausible infrastructure – even in a medieval *watermill-punk* world. I can't imagine that thousands of localized water turbines (even Tesla turbines) would be better than a large centralized hydroelectric powerplant. (Maybe I am wrong?) **How can I justify a *City of Waterfalls* trope to serve a plausible utilitarian purpose?** As suggested by the two photos, the waterfalls don't need to be impressively large or in any particular configuration, just open-air and scattered throughout the structures. I want the form to follow function – whatever that is. My setting is sci-fi/fantasy (no magic, not Earth, all human) with refugees living around repurposed heavy industry, so my "waterfalls" need to serve a utilitarian function (at one time if not currently). I am specifically **not** looking for *aesthetics* or "because they can" reasons, such as [the waterfall skyscraper in China](https://www.curbed.com/2018/7/26/17616286/waterfall-skyscraper-china-guiyang), rather a utilitarian or infrastructure purpose. [Answer] Low-tech climate control: the waterfalls fill the air with spray, which evaporates off and cools the populace. The Romans used to achieve a similar effect with fountains. [Answer] Still water is heaven for proliferating algae, bacteria and annoying insects like mosquitoes. A large city with large bodies of still water is a recipe for plague spreading. Having water on the move keeps the water clean and, as a consequence, the city healtier. Also, waterfalls help enriching the water with oxygen, helping bacteria to decompose organic matter suspended in it, again improving cleanliness. [Answer] Energy storage. You use a form of energy generation with unreliable or periodic output. As a form of energy storage you pump water up into a nice big reservoir when you have surplus, then power turbines by letting the water spill back down to a lower reservoir to create a more steady power supply. It might be more efficient in an enclosed system of pipes, but for aesthetic reasons and public morale it’s much nicer to have exposed waterfalls in public spaces. As @PluckedKiwi pointed out in the comments, the presence of additional waterfalls/ absence of usual waterfalls can act as a very public indicator of current energy supplies. It’s pretty simple, pretty reliable and pretty. [Answer] You're looking at it backwards. Nobody added artificial waterways to a city. They did what they had to do to support building a city on top of existing waterways. Human settlements naturally spring up near water sources for a number of different reasons. An annoying drawback of these water sources is that they limit the settlement's ability to expand. When the settlement evolves into a city and you need more room, you can't simply move the water source out of the way (unless you're [Dutch](https://en.wikipedia.org/wiki/Polder), of course). In your image, the cliffs add another limit to how far you can expand your city. You're trying to make the most use of the land available so you've clearly built your city all the way out to the cliff edges and to the very banks of the river. Rivers are notoriously restless things, though. They meander all over the map and when they run over a cliff edge, they slowly erode away the cliff. Neither of these are particularly good things when you have roads and buildings in very close proximity. A relatively cheap and easy solution is to constrain the river so that its course is fixed. Line the river channel with concrete to prevent meandering, and design outlets at the cliffs that prevent erosion. Add artificial channels with multiple outflow points to increase your water throughput, which helps protect your city against river flooding. You'll end up with a large-scale erosion control project where you've carefully replaced the river's natural bed and channel with erosion-resistant material, and where you carefully monitor and control water levels, diverting water as necessary to avoid flooding. To an outside observer that didn't see your city before the project, it looks like you built a bunch of waterfalls for some reason. [Answer] # Waterfall is power In [Shannara Chronicles castle of Humans](http://shannara.wikia.com/wiki/Leah) was built on what looks like hydroelectric dam: [](https://i.stack.imgur.com/Ri6WM.jpg) Both having electricity (or other kind of energy if it's fantasy) and being able to dry or flood large terrain is pretty utilitary, and nothing shows it off better and is foolproof more than simple waterfall - it keeps maximum level of water in reservoir without any moving parts that could break. # [Graduation towers](https://en.wikipedia.org/wiki/Graduation_tower) If you have a salt mine nearby, waterfall can be used to increase salt in solution, an important step in salt purification. Sure, most common design is based on wooden sticks, but regular waterfall requires far less maintenance. [Answer] > > refugees living around repurposed heavy industry, so my "waterfalls" > need to serve a utilitarian function (at one time if not currently). > > > A. **Diverting a major waterfall for mining** Vital minerals were found under and on the vertical face of a large natural waterfall (Niagara etc.) In order to mine them, a method of diverting the water away was invented that didn't require changing the course of the whole river. That was impossible for large-scale geographical/geological reasons. The old civilisation simply built chutes outwards from the top of the existing falls. Eventually the outward aspect of the mine became huge and more and extended chutes were added at different levels. People who lived at the mine workings had their own personal chute to keep their house or front door dry. This all proliferated in a haphazard and *ad hoc* way. B. **Sluice boxes - panning for gold** Where the two mighty rivers meet the silt is churned up and gold can be found. A powerful family and their thralls took over the whole of the ramshackle mining town that had grown up around the confluence. There are many sluices fed by the river that filter out the gold. The powerful family gradually built a beautiful city on their great wealth and the gold-collecting sluices were made more and more beautiful as well as retaining their function. You could literally dip your hand in one and have a handful of gold. [Answer] There are several purposes which you can fulfill with a structure of channels and waterfalls. On the one hand, channels within your city provide a fast lane means of **transportation** in any age of human technology. As L.Dutch pointed out, keeping the water moving instead of standing still keeps bacteria and algae from developing into serious health problems for your citizens. They can also provide either a source of **fresh water or a sanitation** possibility (more plausible in a low tech setting) for your citizens. Definitely, if have water channels and even more so, if you have water falls, you are provided with a natural way of **micro-climate regulation**. Cities tends to heat up in summer time/during heat periods, which water can compensate providing a **cooling effect** and keep the air from becoming too dry to make infections of the respiratory system more likely. In addition, the **aesthetic effect** of water channels and park lanes or avenues alongside it should not be underestimated - it keeps your citizens happy alongside more efficient infrastructural uses. The platforms above water falls can also make attractions for the city's more advantaged citizens/nobility or possibly every citizen and **demonstrates the power of their ruler** to be able to build such an amazing structure. In addition, these large waterfall structure can actually have the **turbines** of your city-wide power plants **at their bottoms** without limiting the effect of any of the advantages listed above. [Answer] If staged and planned right artificial waterfalls can increase the sound quality to an area. Flowing water can dampen sounds that are undesirable and create curtains of white noise to block out anything that could be considered undesirable as noise in an area. I've worked construction jobs before where if you had a river or waterfall near by you wouldn't hear as much construction depending on which side of the water you were on. [Answer] [Hydathodes](https://en.wikipedia.org/wiki/Hydathode) [](https://i.stack.imgur.com/z5hao.jpg) <https://www.botany.one/2017/07/hooray-for-the-hydathode/> Plants sometimes can build up internal water pressure. The water needs somewhere to go or it could burst the tissues. Some leaves have special pores called hydathodes. These pores release excess water in a process called guttation. So too your city. Underneath there is excess water pressure. It must be released in a controlled fashion or it will invade buildings and ruin roads. The hydathode towers allow the pressure to be contained and released. Bonus: Hydathode is a rocking fantasy name for a city. [Answer] Your city gets its water from nearby mountains, however due to the proximity and difference in height the water arrives at very high pressure, too high for the primitive pipes of the time to handle. Since the city does not have valves and other control systems more importantly part of the city needs that high pressure (water wheels). The simplest way to bring the pressure back down so the water can be sent to other districts is a waterfall which releases all the pressure at once in effect resetting the pressure gradient and bringing it back down to a manageable level. But the city is clever the pressure is used to drive a water wheel system, overshot water wheels in which the water comes from above are much more powerful than undershots ones. So they have row/stacks of water wheels powering various mills around the city, but you cant push all the water through wheels it is too unpredictable and will wreck tour mills. so excess water simply goes an alternate route and falls (see image). The city designer was smart enough to realize leaving the waterfall design allows for the city to build more mills and wheels later, allows the mill wheels to be well controlled, and lets the same water be sent to homes, irrigation, ect. You will see many falls staggering downward to generate different pressures for different purposes, high pressure for irrigation, low for drinking water, ect. Niagara falls used to have a massive mill complex, but the mills could never use even a fraction of the water available there was just too much. later tourism became more profitable than the unsightly mills. If a city had been built around both the unsightly mills might never have disappeared. [](https://i.stack.imgur.com/TwgnP.jpg) [Answer] You're mentioning heavy industry, so in addition to already mentioned climate control a very strong and useful function of waterfalls would be ## Reducing pollution Tiny water droplets that are included in a mist are capable of capturing and holding dust and pollution fine particles. Then being heavy they fall down on earth and are eventually washed to sewer system. As the droplets small enough are not that easy to distribute over the city, as the city grows the mist generators (namely waterfalls) are added. In modern times China uses this technique, however instead of waterfalls they have special [mist cannons](http://www.chinadaily.com.cn/china/2016-12/05/content_27566207.htm). > > The mist cannon, which is not well-known but gaining popularity, is a large machine mounted on a truck that sprays water mist. (...) > > > "The truck works by nebulizing water into tiny particles, with diameters in microns, the same as PM2.5 and PM10, and spraying them into the air, and then they could combine with the dust and fine particles to fall to the ground," Xu said. (...) > > > According to tests conducted by researchers with the China National Environmental Monitoring Center, the mist cannon and the chemicals1 can together "cut the PM10 by 20 percent, PM2.5 by 5 percent and nitrogen oxides by 10 percent", according to Xu. > > > There are two trucks covering 35 streets > > > --- 1The chemicals are used to capture pollution fallen to streets, mostly from cars. [Answer] Defensive purposes: The city is on water, but cannot be attacked on water, because the the waterfall is making an almost unescapeable stream. The city is also granting very less option for an ground attack, because of such small bridges, which are even destroyable or which can be pulled in like castle bridges. If the bridges are completely destroyed the city is only accessable to creatures(/machines) which can fly or can resist a waterfall stream. That makes good military bases too. [Answer] **The answers so far are awesome.** They talk about energy/power, water, air quality, aesthetics, and warfare. There is a line about "transportation". Mining. The assertion that the waterfalls were there and they did what they had to. But I could add a few others .... Your pictures show overshoot waterfalls, which allow a reservoir behind the falls that is higher than the water in front of the falls. Given the Gibbs free energy surface of water, that is to say, given that water bonds have high energy, and nature goes to the lowest energy state, there is a preferential movement of stuff in the water to the surface. Alcohol does this. **It could be a mechanism for separating things that are somewhat soluble** (think stills and moonshine), but also have a lower Gibbs free energy surface, like an open-air refinery and storage. **Ponds like that could also be about sky-cooling.** (It is one of my favorite techniques, and a technology lost to the modern world). [This guy](https://www.ted.com/talks/aaswath_raman_how_we_can_turn_the_cold_of_outer_space_into_a_renewable_resource) is selling silicon, so he contrives his answers only in terms of silicon. Silicon is not required. He asked the genii of his mind a weaker question, and received a weaker solution. **Water isn't always liquid.** It freezes. It evaporates. What happens when the freezing cold of winter hits those styles of falls. At least half the volume is stored as liquid behind the (very insulating) ice of the frozen fall. It could be about retaining liquid, possibly retaining **biodiversity** such as aquaculture fish, or magical protozoa, or such. Humid air is heavier than normal air, so the pit-like region could be about retaining humid air. There could be a half-and-half where **the "humid" "air" forms mists, or micro-clouds**, that have a purpose. Water is made of hydrogen and oxygen. Perhaps it feeds an oxygen converter? Fusion power-plant? Deuterium-oxide (heavy-water) or tritium-oxide (very heavy water) mining for **nuclear-energy uses**? **It could be used to transport oxygen.** Modern fish-tanks have waterfalls that entrain and dissolve oxygen so the fish can live. There are other gasses that could be entrained for life. The available gasses depend on the atmosphere and the nature of the life in the water. The blocks at the lower part of Logans run are for turbulating (and slowing down) rushing floodwaters. Rivers don't always run at the same height. When there is rain upstream they run high. Perhaps this is about enduring the larger climate instead of the local comfort. **Perhaps, like the cathedral under Tokyo ([link](http://www.bbc.com/future/story/20181129-the-underground-cathedral-protecting-tokyo-from-floods)), they help the city to endure natural disasters.** I like to think about things like chemically **pumped lasers**. Ever hear of the Jello-laser? What if it is carrying particulates of metastable lasant through a beam-line? You would need something about the waterfall to not poison the metastable state, and you would need a long enough metastable lifetime. The "COIL", chemical oxygen iodine laser, had long metastable lifetimes. I often wondered if it was a dual-use technology, because the iodine could be used in the 3rd stage of fission-fusion-fission nuclear pumped lasers as part of a 3-stage nuclear weapon, or even a star-wars-esque nuclear pumped super-laser for engaging a ground-based target with mega-scale laser irradiation. If there was a material with a long-enough metastable lifetime, the civilization could be **filtering it from the water, from a far past war, filtering it from the water to power their infrastructure**, or rebuild the terrible ancient weapons. I thought about this for a long time, but I think there may be waves in the oceans that have been moving since the big bang, that carry some of that information. I have also thought that if there were two places that had a "structural weakness" in the universe where it would be easier/easiest to make a worm-hole, and one of them was at an ocean, the waves would show it. An ocean that is a billion years old, could have a billion years for the gravitational or inertial perturbations of the wormhole-end collected in a way that is encoded in the waves. I have thought about the Nikola-Tesla + Philadelphia experiment, and wondered if Tesla's inverse free electron laser, meant to absorb radar for radar-scale invisibility, by oscillating the ship at the frequency of the radars, stumbled onto such a phenomena. By inverted, I think he turned a FEL inside out, so the beam became like a surface on the outside of the ship. If an ocean had those Tesla-Philadelphia waves, then a super-intelligent race might use a waterfall in the ocean to try and distill primal oscillations in order to **build doorways to other worlds**, or other dimensions, or to measure far-away parts of the universe remotely. It could be about **plumbing**. Dinosaurs make a big poops. I've seen [pneumatic logic circuits](https://www.hydraulicspneumatics.com/200/TechZone/PneumaticValves/Article/False/6455/TechZone-PneumaticValves). It could be a hydraulic variation, where it is **performing logic or computations**. If it were the right material, it could be a **quantum computation**. [See slide 41 of this](https://www.slideshare.net/EngrStudent/les-from-first-principles) to show macro-scale quantum-mechanics (top row of table) connects Heisenberg scale to Kolmogorov scale, its on the order of 10 microns, or about 1% of a millimeter, but who is to say that a large-scale structure running a surface of such quantum computations would not look like a waterfall. In a world at war with marine creatures, they could be used through giant pipes **to make very loud, very specific wavelength, underwater sounds**, like active sonar, which [devastates current cetaceans](https://www.scientificamerican.com/article/does-military-sonar-kill/). It would be like a giant pipe-organ, for water, that makes sounds that fend off war-parties. You could make sounds that are loud above ground too. Could they power hydraulic and/or steam cannons? Water powered resets of siege warfare equipment. Can we make a water-driven reset of a trebuchet? We could make ice rocks to shoot, or ice arrows to shoot. **It could provide both ammunition and motive power.** I lived in the Sonoran desert for 16 years (Phoenix), and one thing that happens every time it rains is desert spores reproduce like mad. I had a friend who was allergic, and when they lived downwind of a football field, they had alergy attacks every time the field was watered. **The waterfall could be about aerosolizing water, to trigger molds or other organisms.** **Update (Jan 2019):** * They could act like a giant **"[bong](https://en.wikipedia.org/wiki/Bong)"** in filtering part of an aerosolized "medication" so that the remainder was a higher quality in some way. * If the civilization had a "infinite cold source" then it could be used to turn liquid water into freezing clouds of ice. I've thought about it some, but there are going to be optimal crystal configurations for ice-replication. There have been sci-fi stores about building ice-format that self-replicate and **"destroy the world" into an ice-ball**. If they exist, those are encoded at a microscopic scale in the axes and shapes of snowflakes. I think you could make micro-snowflakes with great Stokes numbers (so they stay in the air for a long time) with surface roughness/smoothness such that they are very effective reflectors of light, so they change albedo. I could see something like this as **a doomsday weapon against a world**, to turn it into ice by injecting enough of those crystals, at a high enough rate, to destroy the world, and make it fight against recovery - to make it resist ability to sustain life forever. It might take simple oscillators and flow directors up near the top, and the right kind of blower a little farther down. I've wondered if China/Mongolia could make something like this that injects into the jet-stream, and turns Alaska into an iceball while making a solid ice-bridge at the Bering strait. How long does that area have to be kept at 40-below before the ice gets "deep enough"? A counter-waterfall could "drown out" or have chiral anti-snowflakes that either reduce below critical concentration, or selectively target and capture the problem flakes during interactions. This would allow two competing massive waterfall/snowmakers to fight it out, where one sustains a warmer climate, and the other tries for ice-ball. * If they wanted to a civilization with giant acoustics, and existing clouds, might want to try and induce the super-thermal-radiant surface topology into the top of the cloud layers, so they might make very particular acoustics to make **non-snowflake based ice-doomsday weapons against the world**. * Converting gravitational potential energy into **heat for some warmth increase**. ([link](https://www.quora.com/In-waterfall-why-does-the-temperature-vary-from-top-to-the-bottom)) In a high gravity world, the potential heating effects are much higher. There is an interesting effect that the center of the planet is weightless. There is a linear decrease in "weight" as you go toward center. If you wanted to stake a "Krypton" energy source, then redirect the gravity waves, and put huge but arguably sustainable crust stresses on the entire world in order to make gravitational potential energy into a "hotspot" for energy extraction. Gravitational wave teleportation? Can gravitons tunnel? Can they be induced into spatial (or temporal, because they are the same thing and the scanning-tunneling microscope is really time-travel too) tunneling? * **Machining**. One could use it as a giant tumbler. If you did it right, you could concentrate the pressure (think about how waterjets make [mach 3 water](https://www.flowwaterjet.com/Machines/Mach-3b)) and use it for cutting, for pressing, for bending, for "peening" * I have been thinking about **the meta-meaning behind myths**, and how the deep past can strongly speak, in much more meaningful and powerful ways that science can, to the present and future. This is in the sense of Jordan Peterson, such as [here](https://www.youtube.com/watch?v=PnYLKjQwLU0). The waterfall could speak something of the deep past to the deep future in a meta-meaning sense. Fruit trees are important to human development, and so something like [this](http://oregonstate.edu/instruction/fw580/pdf/15.%20MDN%20riparian.pdf) could apply. * If we think about a "living planet" like the organ equivalent of the difference between an endo-skeleton and an exo-skeleton such as grasshopper, then water carries nutrients and acts like **[hemolymph](https://en.wikipedia.org/wiki/Hemolymph) or blood**. It could be argued that the air currents are a second type of "blood". If the water is blood for the inside-out massive meta-organism then all that blood is, the water is. Transport. Immune system. Where life of the cells comes from. In this paradigm, a waterfall is where the two different "breeds" of "blood" interact. For an organism, where two fluids interact, there are very specialized tissues, and there is immune activity to prevent propagation of disease. Not only can water transform the gas, but he gas can transform the water. In an organism substantially more advanced than an insect, the **lymph nodes** are where blood and lymph mix and interact - they are a critical part of the immune system. One could argue that rocks, for a living planet, are like bones. So the waterfall is air and water and stone - blood and lymph and bone. * I like Brian Deragon's answer, but we could do a bit of both. What if there was flaming oil on top of water? Coal, when heated, can burn underwater ([link](https://gizmodo.com/the-worlds-oldest-underground-fire-has-been-burning-fo-1539049759)). What if there was submerged burning substance as well as floating ones? Defense? Offense? Disposal of waste? * When I look at the waterfall, I think the sea is lower. What if it isn't. There are dikes in the Netherlands, and when they leak it isn't a good thing. What if it isn't about using something that is going away to somewhere else (the water in the river) but is instead about something scary coming close? **What if the dam is about the coming ocean, not the leaving river?** * Appeal to the unknown: when you (as a technical nerd) want to solve an otherwise impossible problem, you know the center of your domain isn't where it will work, so you go to the half-lit edges. You don't go to the darkness, but to the shadow-areas. It could be that this is the imagination-equivalent of a shadow area in that, psychologically speaking, the presence of these style of waterfalls **accelerates suspension of disbelief** toward futuristic fictional universes. It might be a generational or cultural thing, but it might be a universal psychological mechanism. * I recently watched the pilot episode of ["Dragon Pilot: Hisone and Masotan"](https://en.wikipedia.org/wiki/Dragon_Pilot:_Hisone_and_Masotan). When we think about cooling, there was a sense of "air-conditioning" but this could be a way to cool off a dragon. To cool some highly exothermic, semi-aquatic lifeforms. * [Salmon leap waterfalls to get to their breeding grounds](https://en.wikipedia.org/wiki/Salmon_run). Those who don't make it, don't breed. It could act as a form of **natural selection** for salmon or other aquatic organisms. It is also a route for fresh baby salmon to get to the ocean, so instead of reduction it could be a **protected transport corridor** that typical in-ocean predators cannot overcome. It doesn't have to be for salmon, but could be for tiny things or for huge things. **EDIT Apr 2020:** In a world of telepaths, the wavelengths of electromagnetic radiation are about the diameter of the planet, and fluids like water can transform the paths of the emanations, so for telepaths **a waterfall could act like "Cerebro" on X-Men** (fantastic stories). [Answer] * Cooling the streets * Releasing negative ions - used in office artificial waterfall's and other high stress area's. * Irrigation * Waste Removal ( sewerage ) * Climate control * Radio wave manipulation ( water effects radio waves somehow ) Not the most concise answer but i just wanted to add the main reason we use them at the moment - Negative ions [Answer] # Defense Did you ever try to climb a wall below a waterfall? Waterfalls can help defend your cities in the following ways: * If the waterfalls are designed well enough, they could fall on areas that are likely to be used by enemies (or dangerous animals?) to enter the city. * The spray and subsequent mist helps hide the city. So it's harder for enemies to count the number of guards and spot weaker areas. * If a waterfall is falling in front of a door, it could be a cheap way to keep animals that fear water out of the city, while human will just get wet when entering. It is also harder for people entering to conceal weapons under wet clothes. [Answer] You don't even need to reach into the realms of sci-fi or fantasy for this. Some modern cities have artificial waterfalls installed in recreational areas that serve the utilitarian purpose of masking the city noise. [GreenAcre Park](https://en.wikipedia.org/wiki/Greenacre_Park) in New York City is one such example. A city that contends with exceptional levels of noise might employ such on a large scale. [Answer] You could also work it into your story, by allowing the water to be exchanged for other substances substantially more dangerous, such as burning oil. Then it would not only be an aesthetic choice, but also a defensive choice. [Answer] The waterfalls are a **byproduct** of what your civilization wished to achieve. What they *really* want is to have a deep lake to hide and protect their treasures and have to do something with the excess water. Long ago, the ancient kings found that tomb raiders could not be effectively deterred so they began building their tombs in deep valleys and diverting a nearby river to flood them. Of course, the minor nobility soon followed suit so they began building their own, shallower tombs resulting in smaller waterfalls [Answer] Although the plausibility can be debated, practitioners of [Feng Shui](https://www.thespruce.com/use-fountains-for-good-feng-shui-in-home-1274637) believe that flowing water in the home will bring prosperity. As a result, many Chinese families who have the means will place a fountain or a waterfall prominently in their home or garden, often with goldfish swimming in the pool below. The influence of such beliefs might be one reason why a city would choose to build these kinds of features (appropriately placed of course). And those features might have a plausible benefit, if they attract other believers to the city to work or just to visit. [](https://i.stack.imgur.com/Hl7U7.jpg) [Answer] They fill wells. That picture from Logan's Run looks like an ancient public well I read about - in the Middle East, I think. It fills up during the rainy season. In the rest of the year, people come to the lowest step that's still above the water surface, and fill their jugs. As the water level lowers, the people have to go down to the next step down to reach the water, and so on. [Answer] I'm focusing my gaze on an artificial waterfall something like 5 miles from here. I live in a desert, some years back they basically banned decorative water features other than in a few cases where they are substantial tourist attractions. Yet this waterfall was built after the ban.... What it really is is a cooling tower. Such things are usually a bit on the ugly side and placed out of sight, they simply got fancy with it and made a fully functional cooling tower that looks like a waterfall. Your artificial waterfalls are being used to cool the buildings underneath. [Answer] **Beauty** You ask for utilitarian purposes but I would argue that **art** and **beauty** *are* utilitarian. Every human culture has some form of art going as far back to cave paintings. I would argue that art is a **necessity** of human culture. The fact that your culture expresses that through architectural waterfalls does not mean that they are somehow unimportant in spite of not filling some other pragmatic purpose. [Answer] In addition to all of the other answers, it can also prevent ships, either attackers or people escaping, from traveling on the water. This can help keep the place protected from attack [Answer] The waterfalls are white noise generators. The city contains industries that produce obnoxious clangs, whines, and buzzes. Or stockyards with unruly creatures, flies, and mosquitoes. The sound of the waterfalls masks these noises enough to let people think and sleep. ]

[Question] [ We are situated in an scenario like the Terran cold war in the 1980 era. I am the omnipotent dictator ahem.. president of the "good" side. Recently my research team completed some breakthrough in a revolutionary new sensor technology that relies on an, until now, totally unknown physical force. That technology would allow my military to have a serious advantage in a potential military conflict by being able to detect everything(!) in a very large radius around them. I am sure that nobody else knows about the physical basis at this time. Since my enemies also have able mad scientists they could reproduce it should they know on what principles these things worked. Now I am faced with a problem: In order to use that technology I will need to introduce it to my forces (ships/submarines/jets). That means a significant part of my forces needs to know how to produce, operate and maintain this sensor technology. However I do not want the other side to know that this physical force exists, not to mention on how my system works. Since hostile agents and leaks occur I am concerned about letting anybody know about this. How can I give my forces the advantages of this new technology without leaking information about it? [Answer] # Tell everyone that eating more carrots allows them to see in the dark No really. [That's how radar was kept secret during WWII](http://www.sciencefocus.com/qa/do-carrots-really-help-you-see-dark). > > The idea that it might is due to a myth begun by the Air Ministry in World War II. To prevent the Germans finding out that Britain was using radar to intercept bombers on night raids, they issued press releases stating that British pilots were eating lots of carrots to give them exceptional night vision. This fooled the British public, as well as German High Command and an old [wives'] tale was born. > > > Secrecy by misinformation. You need to generate some sort of plausible explanation for how you're doing what it is that you're doing. As long as it sounds reasonable you can get your enemies buying up all the carrots they can get their hands on. **In terms of general maintenance and release to users.** If you consider the people who put your phone together in the factory, they don't really know how it works, they have a set of parts they put together in a certain order. The people who test them don't really know how they work either, they know the inputs and what outputs they're supposed to get in the test environment. Only a very small number of people need to know the real details of what's going on, the rest are looking for loose contacts, broken circuits and burned out components. [Answer] Well, first of all, the people using the new sensors *don't actually need to know how they work*. All you need to tell them is, "We've fitted some fancy new sensors to your ship/sub/whatever, you'll be able to see everything on an X-mile radius on this screen here, if something goes wrong then come to us and we'll fix it." For the people producing and maintaining the sensors, I'd recommend splitting them up so that each team only works on a specific part and they have no idea how they all connect together. That way, even if the enemy captures someone in the manufacturing division, they won't be able to learn from him how to build your sensors. Finally, I'd recommend building a self-destruct system into each sensor unit. It doesn't need to be a spectacular explosion, it just needs to cause enough damage to the sensors that the enemy won't be able to figure out how they work (or even what they are) should they get their hands on one of your ships/subs/whatever. [Answer] # Disguise it as existing technology During WWII — this infinite resource of answers to questions such as this — Germany developed navigation systems that allowed for "blind bombing" (bombing without seeing the ground or the target) that in theory allowed a bomber to drop its ordnance within 10 meters of an intended release-point. This was WWII... long before GPS was even conceived. This is called [The Battle of the Beams](https://en.wikipedia.org/wiki/Battle_of_the_Beams). The Allies got wind of these devices — the Knickebein and the X-Apparatus — through means such as the [Oslo Report](https://en.wikipedia.org/wiki/Oslo_Report) and plain old spying, and they desperately wanted to get their hands the devices to find out how to develop countermeasures against them. Finally the Allies got the opportunity: a downed German bomber was made available for examination. They had a fairly good idea that such a device was on-board. ...and they could not find it. No matter where they looked, it just could not be found. Maybe it was not there after all? But they had the crew. And they made the smart move to put the crew in the same quarters and placed hidden listening devices the room. Eventually one of the crew slipped and said... *"They will never find it..."* The investigators went back to the plane and looked at all things again. And eventually they found that the on-board [Lorentz landing-aid](https://en.wikipedia.org/wiki/Lorenz_beam) — which was well known to the Allies — had an actual range of about 450 kilometers instead of the usual 40. When people find something they do not expect, they get curious. But when they find things that they expected to find there, it takes something special for them to look closer. Hence: **disguise your super-technology as mundane, already existing technology**. [Answer] You might be interested in the [history of the Proximity Fuze](https://en.wikipedia.org/wiki/Proximity_fuze), which is a fascinating read. It was invented during WW2. It is a tiny Doppler radar mounted on top of an anti-aircraft shell, which detonates said shell when it comes in close enough proximity of an enemy aircraft. This multiplies the effectiveness of AA shells compared to previous tech, which was either a timer/altimeter based on estimation of target altitude, or simply aim at the enemy plane and hope to score a direct hit. This had to be kept secret from the enemy, while shooting them with it! [Answer] You need a cover story within a cover story. On top of all the deception you direct at the enemy, as well as not handing the device out to too many people, start some new sensor project as a cover story for use within your own military. Launch some new spy satellites, open secretive computer facilities, install radar dishes, the whole shebang. Make up a Top Secret need-to-know project which integrates data from a wide variety of sensors and a computer system which interprets it all and outputs a real-time tactical display. Just plug in the real sensor. [Answer] Secretly equip your troops with the new device. Strike fast. Quickly conquer the world. Make your empire a better place. Create world peace and a just empire. [Answer] You can't, not fully. What you could do is make sure it isn't a critical sensor. Let it greatly augment your forces but when it breaks it doesn't prevent your forces from fighting the old way. Then you can create a dedicated group to work with this technology. This will need to be highly trained operatives willing to take their own lives if needed. You obviously destroy the equipment any time there is a chance of it falling in the wrong hands. You could also limit the actual technology to fortified command posts that then relay the information to your units on the ground, or air. This obviously allows the enemy to intercepts your transmissions so you need to use some misdirection here on how you acquired the target. But this still allow for leaks. But honestly anything that's [used in the field](https://www.wired.com/2011/05/aviation-geeks-scramble-to-i-d-osama-raids-mystery-copter/3/) can fall into enemy hands. [](https://i.stack.imgur.com/SUsPO.jpg) Case in point, crashed helicopter during the Osama Bin Laden raid in 2011. Despite efforts of the local team remnants remained. [Answer] Several options: 1. Mask its effect. Have the weapon fire in conjunction with other weapons to make it look like the other weapons have become more effective. 2. Mask its cause. I read a comic book where a super-villain held a bubble gun and fired it at the heroes. The gun actually did nothing, but it got the heroes to look at him so that he could make eye-contact, which was key to his powers. IF you take a similar approach, making the firing sequence seem complicated and requiring obvious steps to fire it, the enemy will assume that the obvious steps are actually relevant and focus on that first. [Answer] Don't use it in places where the enemy may gain access to the device. This is pretty much standard procedure where feasible. For example the first Meteor jets the Brits built during WW2 (yes, the first units were active before the war ended) were barred from flying over German held territory to prevent the aircraft from falling into enemy hands if it were to crash. Similarly, early radar equipped aircraft owned by both sides were not allowed to overfly enemy held areas. In both cases of course the security was moot as the other side already had similar or identical technology, but that was in both cases not known (though suspected no doubt). Also, you keep the people involved strictly incommunicado (or try to at least). That's how the secrets of Bletchly park and the Manhattan project were kept until well after the war. Not just was the machinery involved (early computers, nuclear weapons technology...) top secret to the point nobody except a few key people knew what they were working on or with, but those people were housed in remote areas with no contact with the outside world that wasn't strictly censored (and despite that, the Soviets were still able to steal the nuclear technology from the Americans by infiltrating...). Having a good story to explain the effects without exposing your secrets is core to the disinformation campaign that's going to be needed. So if you've broken the enemy's ciphers, be prepared to spread rumours about secret agents inside their security agencies. If you've a new weapon, invent stories about something else that'd people could believe can do the same thing. In the ultimate scam, invent and build entire labs and fake experiments and make sure the enemy gets wind of their "successes". The biggest hoax of all that was perpetrated like that was the US Space Defence Initiative (SDI/Star Wars) which never existed as such (or rather, never was more than a paper study, but fake experiments were staged to make the Soviets think that working prototypes existed of weapons entirely different from what was being studied and were ready for deployment). Smoke and mirrors... [Answer] # Have alternate plausible explanations for how they got the information. The British interception of the [Zimmerman Telegram](https://en.wikipedia.org/wiki/Zimmermann_Telegram) is a good example of how this can be done. In WWI, the British intercepted a telegram sent to the German embassy in the United States, and upon decrypting it, determined it to contain information that if revealed to the U.S. might get them to join the war. Specifically, it was an offer for Mexico to ally with Germany and invade the U.S. in the event that the U.S. joined the war in Europe, along with plans to engage in unrestricted submarine warfare. However, the telegram was sent over a U.S. cable that the U.S. didn't know the British were tapping, and encrypted using a cipher the Germans didn't know had been broken. The British needed a way to share the telegram with the U.S. *and* convince them it was genuine, without revealing either of those facts. Since the British knew the contents of the telegram, they knew that it would have been forwarded to Mexico using a lower-security cipher. The British had broken that one too, and they didn't care as much if the Germans discovered that. So they bribed a Mexican telegraph agent to get a copy of *that* version, then decrypted it and sent the plaintext version to the U.S. along with an explanation of how it was decrypted. Since the U.S. telegraph offices would have copies of the ciphertext version, they could decrypt their copy and compare with the one supplied by the British to verify its authenticity. So at this point, the only thing that might suggest that the British were tapping those lines or had broken the original cipher is the question of why they decided to steal the telegram from the Mexican office, but that's something they might plausibly have done without knowing the contents, so they were able to safely share the information with the U.S. embassy. [Answer] Make the information too unbelievable. This only works if the enemy has no knowledge of the project at all, but there was a historical precedent (at least anecdotally). The Bell P-59 was the United States' first jet project. During test flights the pilot wore a gorilla mask, a derby hat and smoked a cigar. The reason being that if any other pilots saw a strange plane with no propeller, being flown by a smoking gorilla in a derby hat, they would be unlikely to file a report about what they saw when they got back to base. It's a good story although the authenticity has been debated for years, hence why I said it was anecdotal. They did however fit a wooden propeller to the aircraft at one stage when the desert test facility flooded in the rain and they needed to move the aircraft by road. There are photos of it with a wooden propeller prominently sticking out from a tarp covering the rest of the nose. Anyone that saw it would be unlikely to guess it was a jet. [Answer] If they don't know the force exists, they will have a hard time duplicating the technology because they won't have instruments to measure what is going on. If your technology used electromagnetic waves in a frequency band that others found hard to make images in, they would at least have detectors for the waves and could understand how your devices work. If it is a completely new physical effect, they won't have the ability to measure it, which will slow them down a lot. You might also be able to justify that it wasn't "in the air" and the enemy has already discovered it as well. Still, you have a perishable advantage. The enemy will figure it out given time. The first downgrade will be when the enemy figures out the general capabilities. They may not know how it works, but if they know what you can see they can blunt the effect. Ask your military strategists to wargame the situation where the enemy knows what your capabilities are. How will they adapt their tactics? Is it still an overwhelming advantage? One example: military bases have sentries to keep intruders out. It is easier to have rings of defense where you catch 90% of the intruders in each ring than catch them all in one ring. They might have guards wandering around randomly looking for intruders. With your sensors, you may be able to evade the guards. The enemy might put more guards on so every spot in one ring is watched all the time. That is still an advantage to you-this costs money and equipment and may withdraw frontline troops-but maybe it is not really big. Do they have a few very high value assets that you can neutralize if you get up close and personal? Think the Death Star. You need to take them out before the enemy upgrades security. Are you fighting a war of attrition with large volumes of equipment on each side? Do you have the command, control, and computing to make use of it in a mass battle? Trigger a massive battle before they understand what you can do. You can inflict a lethal amount of damage, then mop up what is left. Since it is a magic device, you can make it small and able to fry itself to stay out of enemy hands. Give each one to a particular person and implant some sensors in them. If they are incapacitated, the device fries itself. This offers a plot line where one of your operatives is captured and the device might not fry itself. If it doesn't, you can play with their efforts to understand and duplicate it. [Answer] The way that has worked for ages. encase it in epoxy. You could leave various pressure capsules scattered though the epoxy with surprises for people cutting in. they should be randomized placement. Include a light sensitive chip that will send a pulse to a detonator that slags the contents. Have a button on the outside that does the same thing. A small thermite charge will make it a hot time in the old town tonight. [Answer] Some great suggestions about misleading that I think could be practical thusly... 1. Quickly assemble a Censor Fusion Drone" (CFD). This plane will secretly have your Radical New Radar (RNR) onboard, but it will also have lots of receivers/transmitters for a new kind of signal that is its ostensible purpose: communicating with all the planes in an area and fusing/controlling their individual radars to give an unprecedented view of the battlefield. 2. Upgrade the radar in all of your normal planes to have new transmitters/receivers, which transmit a signal based on their own radar and which receive signals which help to tune and steer their own radar. These signals are between the planes and the nearest CFD. Brief all the technicians and pilots about this and have them keep it secret. 3. In reality, the links from a plane's radar to the CFD are somewhat based on the radar, but is mainly a diagnostic tool, and the link from the CFD to the plane is similar. It's mainly to detect a loss of communication between the two -- for example as the result of damage to the plane -- so that you don't have a suspicious issue where a plane's been flying for three weeks with a melted circuit board. (At the same time, the communications are real.) The "fusion" aspect of the CFD overlays and hides the secret RNR. If a CFD is shot down, it will actually knock out your enhanced view, and you will obviously put a high priority on defending the CFD to protect its "fusion" role. Throw a self-destruct mechanism on the CFD, and also instruct pilots that they may be asked to strafe/bomb/destroy the CFD if it ever crashes in enemy territory. 4. Set up a command center to pilot one or more CFDs. Say the command center is something like NORAD in the US: highly secure, isolated, etc. Say 50% of the personnel there are support, security, etc, 40% man the consoles showing information from the fused CFD feeds, 5% actually control (fly) the CFD, and 5% are in a back room and are supposedly liaisons receiving intelligence feeds from spies, satellites, and other black ops assets. Of course, the "intelligence feed" is the actual RNR. The other people at consoles in the main room are either seeing something from the plane radars, or a degraded version of the RNR. (The guys in the back room could also selectively degrade/un-degrade those feeds so someone could spot something if need be.) So the commanding officer might hear from the back room that "intelligence indicates that the enemy has launched three super-stealth planes that might defeat our fused radar" which actually means that the full RNR feed sees those planes, but people sitting at consoles in the main room can't see it. I think this would disguise the program pretty well. The cover story makes total sense and pretty much totally overlays what's really going on. [Answer] 1) Leak news stories in the tabloids about talking parrot spies who have been given a secret new "IQ Serum". Have actual "secret labs" set up where people answer the phone and say "no comment" before hanging up. Supply pictures and interviews with animal trainers and biochemists. Say that the birds have been trained to make phone calls and place reports. Have pictures of the birds with coins operating pay-phones! 2) Have telephone-psychics announce impending attacks on live TV so that troops are moving to intercept at the same time the public is taking cover. 3) Scatter the sensors on phone and electric towers throughout the country. Put them right by the light on top. Call it a bird deterrent. Telephone modems existed in the 80's, so the technology could be used to transmit sensor data. Have some poor family go one the local news and talk about how accumulated bird droppings on powerlines caused a fire that severely injured or killed family members. Make a story that has everyone crying. Protest groups in the local town make the devices mandatory for power lines near houses (data processing centers). Start a nation-wide movement where the government RELUCTANTLY pays for them in the interest of public safety. AS LONG AS it looks like they DID NOT want to do it, but the people insisted. 4) Return to the tabloids and say that the government has been receiving signals from a friendly alien race. 5) Invent an 80s version of Snowden, and have everyone believe he lives in the enemy country, as a high-ranking member of their government. Have weekly press releases from pirate radio stations replaying the frantic warning calls (that never actually happened) to your countries police stations. It will be an underground hit bigger than "Rescue 911". 6) Have the tabloids release pictures of the new "Electro-Glass Microphones" that the government has been putting on kites and clear weather balloons, that are "ALMOST invisible". Say they are transmitting on certain frequencies, and release balloons occasionally that interfere with TV and radio broadcasts. Have reports of them crash-landing on people's houses every few weeks. Have the whole town shut down while the military "recovers" the small almost invisible technology with their "invisi-glass detector gear". Let the enemy hear rumors about how this glass has a slight metallic content, and highly radioactive beams from a concentrated source make the parts visible on XRay film. Have a two or three hour buildup of military forces before the town is locked down for the search. Publicly scrutinize the military for taking so long to lock it down. Hint that the technology could easily fall into the wrong hands. Use the time window to trick spies into searching for non-existent parts to recover, and capture spies. Interrogate spies on what they know about unreal technology for several weeks before allowing a single STUPID spy to escape during a prisoner transfer, or a mass-escape from the facility by other "prisoners" who are actually special ops troops who help the spy return to their own country. Monitor theft of xray film and report on the news that xyz film company has been robbed 6 times this week.. to attract more spies looking for equipment. Any stolen radioactive material would be easy to spot from the air. Leaked faulty plans for scanning equipment means that spies trying to use the equipment will be dosing themselves during the search, shortening their effective lifespan as enemy agents. The enemy will have lots of good agents give their lives to acquire something that does not exist. 7) Report that enemy planes are known to vibrate at certain frequencies that effect moisture in the atmosphere. Say that you can use beams of light at night to scan the sky and see the vibrations. or that looking at stars allows you to see the vibrations as the light wavers. The enemy will have to rebuild their entire airforce two or three times to get the planes to "vibrate differently". Say that the sheer volume of the vibration causes these waves over 3/4 of a mile. Also point out that civilian telescopes and those at universities are NOT properly focused to see the effects. This will keep them from becoming terrorist targets. It will also make the enemy frustrated trying to figure out the optics behind it, as no known telescope available to them is capable of seeing it, so they have no way of knowing if their new designs will work or not. 8) Ask at UN conferences for ALL allied countries to send us their BEST entomologists! Ask specifically for ones that have a background in long-range radio communications. Ask for any research information on radio frequencies that may or may not effect mosquitos and their reproductive cycle. Ask about mosquito breeds that are resistant to insecticides, and anyone who has an immunology background pertaining to flying insects. Ask for experts who may have placed radio transmitters on mosquitos, or have used radar to track swarms of them. Ask for bug-intellect studies when exposed to high levels of focused microwave radio beams. Ask for REALLY weird bugs and radio related intel and personnel. THEN START A MASSIVE COVER-UP! Burn the labs and all the research. Report scientists kidnapped or killed. All of the FAKE scientist who the govt has been sending abroad should cease to exist. Deny ever knowing them. Deny they ever lived. Burn the record offices in their supposed hometowns.. or just that one file cabinet... Deny the conversations took place at the UN meetings. SOMEONE, SOMEWHERE will start leaking information about your country's attempt to use large swarms of radio transmitting mosquitos... and the enemy nation will create an insecticide or bug virus to rid your country of mosquitos for you. 9) Report that an enemy pilot called his mother before the mission, and the call was intercepted. 10) Report in the tabloids that UNNAMED members of the royal family, or ruling party of the other country secretly want to come to your country because they like one particular type of food that their country does not have. Report that their craving for this food is so strong that they trade battle plans with your govt for just a taste of it. The secret police of the other country will constantly follow their own leaders trying to discover the mole. (DO NOT name the type of food!) 11) Report that emissions from enemy fuel leave trail in the sky that are visible on spectrograph over long distances. Emissions from jets, bombers, and even submarines are equally visible. (This can even be a follow-up for scenario number seven!) Have one of your best scientist who was working on low-emission fuel leave the country for tax evasion. Have them hide in a country that has ties with your enemy, have them seek employment and wait to be recruited. Have your scientist work WITH the enemy to create low emission fuels, which will benefit the entire world once the info is leaked. Let them use a HUGE CHUNK of their military budget to do the research and testing. [Answer] This is a real-life problem, and has many real life solutions. Unfortunately, there isn't really any one answer. Instead, each system is its own special flower and has its own engineered solution. The US DoD approaches are mostly described as "Anti-Tamper" for solutions built into the system (e.g. <http://www.acqnotes.com/acqnote/careerfields/anti-tamper>). The overall approach is documented in "Program Protection Plans (PPP)" (e.g. <http://www.acqnotes.com/acqnote/careerfields/program-protection-plan>). This website has some useful background info: <https://at.dod.mil/content/atscbackground> [Answer] Look at the space program! The spread of the Saturn launcher production and design was so big that engineers never really knew on what they were working on until late, and til this day, we couldn't completely reproduce a Saturn V launcher without disassembling one and reverse engineering it. Otherwise, as you're a benevolant dictator, you could always mass produce the thing from a very far and remote part of your country, and purge every now and then workforce. Soviets were pretty good at this with their scientists.. [Answer] There's a pretty good trope for this: # The black box: [](https://i.stack.imgur.com/g5kr3.jpg) Problem is, that they don't need to know, how to build one, however, aside from the obligatory self-destruction I use a technique to make my question incomprehensible to most mortals in Stack Exchange: # The Noise Here's what you have to do: 1. Make it as overcomplicated as possible, with lots of cheap, easy to mass-produce parts. 2. Create false manuals that mark these unnecessary features as crucial and important, but also detail a way of repairing them, albeit with false becauses as an explanation. 3. Indoctrinate high-ranking individuals to the real workings of the device, but ensure, that everyone knows only a little part of the whole. We need higher ranking individuals because if they kill themselves, the enemy will think that it was because of the military plans they know, and not your little trolling. 4. Invent a new language in which the manuals will be written. 5. Indoctrinate some individuals about this language, so they will be necessary for decoding the manual. 6. It's an everything sensor, so how you're going to fool its users? Faulty algorithms, that can be automatically corrected by another, seemingly unimportant computer that was destroyed, along with the submarine. 7. ??? 8. Profit [Answer] ## Make it look like an UFO (it worked for the US Army!) The US Army did this with the first stealth plane: keep strict control over all team members, make up cover stories, pretend it's a test model for something different, make up plausible explanations that it's something else, dismiss sightings as UFO paranoia, confiscate any physical proof, pay any witness to keep quiet (works better that simply making threats?). [Keeping the SR-71 Blackbird (the World's First Stealth Plane) Secret Was Near Impossible](http://nationalinterest.org/blog/the-buzz/keeping-the-sr-71-blackbird-the-worlds-first-stealth-plane-17936 "Keeping the SR-71 Blackbird (the World's First Stealth Plane) Secret Was Near Impossible") ]

[Question] [ ## BACKGROUND I'd like my earth-like world to have a naturally formed narrow strip of land that bridges a major sea. Now, before anyone rushes off to comment about island chains and land bridges, I'll add that I'm looking for unusually long, thin, and well, road-like formation. --- Here are the guidelines: * **The thinner the better.** The ideal would be to form something like an actual road, approx 5-15 meters wide. Recognizing that this seems very, very unlikely, I'd still be happy with answers that helped me form a landmass as thin as a few kilometers. * **The road should be shaped like a curved line.** Thankfully, nature makes this is a lot easier than a straight one. * **The road should span between 500-2500 km.** I'm still working out the distances of my world, but this is a probable length for the sea in question. Being able to scale an idea up or down a bit would be a very good thing. * **The road can be irregular.** It can widen and narrow, rise and fall, so long as it retains a basically long and thin road-like shape. * **The road does not have to be unbroken.** The easier it is to walk the better, but small gaps are fine, so long as they can be crossed by bridges or ferries. I'd like there to be no more than a few large gaps, and none larger than approx 30 km. (Taking a cue from the English Channel.) That said, if a motivated ancient empire with good engineers and durable concrete could make it work in the long-term, then it's good. * **The material can't be too unstable.** It needs to last, and it should be possible to cross and build on. (Possible, not easy.) ## STARTING POINTS To start, relevant here is [Adam's Bridge](https://en.wikipedia.org/wiki/Adam%27s_Bridge), a now sunken 50km long and 1km wide land bridge in southeast asia. There is much confusion as to its origin. Moving on, I'd considered a number of possibilities for how to form this, but I'm learning as I go and don't know enough about to weigh or implement them. This included continental drift, underwater mountains and tectonic plate action, etc. My favorite idea was to make the road part of the rim of an enormous crater. If it worked, this would fit my world really well, as impact events are important to the mythology of the terrestrial culture. [Answer] # Your bridge is an atoll like Kwajalein The [Kwajalein](https://en.wikipedia.org/wiki/Kwajalein_Atoll#Geography) Atoll is one of the largest in the world. [](https://i.stack.imgur.com/c3YKV.jpg) Following the curve of the land, I estimate that the distance from the upper left to bottom right corners of the atoll is about 104 miles, or 167 km. The straight line distance is more like 75 miles or 120 km. The width of the atoll is in the range of 500 meters for most of its length, with occasional thickened points that you can see. Despite the enclosed water area of 2174 km$^2$, there are only 16 km$^2$ of land area. Your best bet to get up to 500 km is to either have one mega-volcano which later sank under the sea leaving a very, very large atoll, or a chain of smaller ones that formed at roughly the same time, leaving a chain of atolls that are within at least visual distance of each other. [Answer] As long as your local geography/geology permits sand deposition: # a large sand bar/[spit](https://en.wikipedia.org/wiki/Spit_(landform)) would fulfill all your requirements. Since I'm the most familiar with the geography of the Baltic, here are three examples from the region: [The Hel (sic!) Peninsula](https://en.wikipedia.org/wiki/Hel_Peninsula)  [The Vistula Spit](https://en.wikipedia.org/wiki/Vistula_Spit)  [The Curonian Spit](https://en.wikipedia.org/wiki/Curonian_Spit)  The first example is a bit shorter than required (~35 km), but the remaining ones measure almost 100 kms each. Usually, such formations are in moderate flux, and can occasionally become disjointed islets (but I understand that you're OK with that). The only (but major) caveat is the aforementioned **requirement for some sort of sand deposition process** (as you can see, all examples above are relatively close to land). You might want to tweak your geography so that your points of interest across the major sea do not require it to be smack-dab in the middle of the basin. [Answer] You could use a large **[mid-ocean ridge](https://en.wikipedia.org/wiki/Mid-ocean_ridge)**, like the [Mid-Atlantic ridge](https://en.wikipedia.org/wiki/Mid-Atlantic_Ridge), and then play around with sea levels. Mid-ocean ridges occur at (divergent) plate boundaries, and can be thousands of kilometers long. They can rise high above the sea floor, at times breaking through into islands. So, here's how you make your road: 1. Take a rather large plate boundary and start some dramatic seafloor spreading. 2. Then, lower sea levels rapidly across the planet - not too much, but enough so that the peaks poke through in places. kingledion suggested that an extreme ice age, followed by rapid melting, could expose the ridge, which is a good idea. 3. Enjoy your natural road! It could end up taking you not just 500 or 2500 km, but halfway across the planet, if you want. Here's a distribution of ridges around the world:  Image in the public domain. Credit: US Geological Survey. [Answer] All the answers seem to be focusing on using geological methods. For a completely different natural methodology consider the possibility of long chains of floating colonial sea life forming your roadways on the sea. Some hybrid between coral and jellyfish possibly in symbiosis with [sea weed](https://en.wikipedia.org/wiki/Sargassum) plants or other photosynthetic algae. Floating Sargassum sea weed chains can be miles long as pictured and coral growth can build islands in shallow tropical seas. These organisms are often colonial forming close groups or chains, your world might have a variant that forms very long chains that are thick enough to walk on or use as a roadway. [](https://i.stack.imgur.com/kgQ3q.jpg) These sea roads could be anchored and fixed in place in shallower seas, linked between islands in an archipelago, or may drift to some degree. As natural formations they may branch, dead end, or otherwise change over time. They could also potentially be cultivated and maintained by people who want to use them as roads. [Answer] Your bridge could have been caused by a pre-historic meteor impact like the [Chicxulub crater](https://en.wikipedia.org/wiki/Chicxulub_crater). Meteors push earth up around the point of impact. Depending on the type of dirt involved in the impact, the more shallow areas could conceivably form a curved land bridge where the deeper-side of the impact would have been entirely lost to errosion. [](https://i.stack.imgur.com/wBXRy.gif) [Check out the larger original here](https://en.wikipedia.org/wiki/Chicxulub_crater#/media/File:Chicxulub-animation.gif) --- **EDIT:** I was looking at the [link @Era provided](https://en.wikipedia.org/wiki/List_of_unconfirmed_impact_craters_on_Earth#Mistaken_identity) in the comments below and it produced yet another idea (way to go @Era!). Let's a assume a massive volcanic caldera with strong basalt deposits in the outer ring but porous pumice or lava rock in the center ... something that can be eroded over the millenia. This would probably be unbelievable for 2,500Km, but could be believed for 500Km (bigger would require a tectonic ring of fire that subsided, allowing the surrounding ocean to flood in). What you would get is a very large version of this... (Yes, it's a sinkhole, but that's basically what an eroded center is.) [](https://i.stack.imgur.com/b0MPj.jpg) [Answer] **Try a subduction zone induced island arc combined with a coral reef** They can create long thin islands and chains of islands. They can be massive and they solve several other problems. Just look at the Aleutian island arc in Alaska and Russian (Aleutian and Commander Islands), they nearly cross the ocean they are well within your length range (~2000 km). they are created by a subduction zone. [](https://i.stack.imgur.com/f6q58.jpg) Add in Kingledons' idea about coral reefs and you could easily end with something buildable, If they were not so far north they probably would already support a near continuous coral reef, the land height is good for it. It is already possible early people hopped across these on boats to reach North America. If sea level dropped exposing the reefs you could easily end up with a continuous or near continuous land-bridge. Note it takes care of several other requirements as well. people live on many on the Aleutian islands even though they are earthquake prone so they are easily stable enough. The arcs are always curved (or have multiple curves) due to the forces involved but the amount of curve varies, so that solves another requirement. You can cross from one continent to the other without ever going below 182 meter with present sea level, (thanks Gerrit) so drop sea level just to the last minimum (20,000 years ago) and you can cross without ever going below 62 meters and that is by far the worst stretch (the part with the deepest high line right near kamchatka), the vast majority of the chain would end up above the water line. so you have one or two short ferry trips and you are on land. And that is just for an existing example on earth, you could easily make one that suits your needs and is believable it has happened in earth's past, . You will still have at least one gap, likely more but that is just water pressure and tides at work, you can even reduce this if your chain is parallel to the tides. You can easily end up with something that can be crossed by modern bridge building technology, or primitive technology combined with short boat rides. [](https://i.stack.imgur.com/V3voq.jpg) [Malaysia and indonesia](https://www.google.com/maps/place/Malaysia/@0.541851,101.2182472,3.97z/data=!4m5!3m4!1s0x3034d3975f6730af:0x745969328211cd8!8m2!3d4.210484!4d101.975766) would be another good example to look at. [Answer] **Prehuman ruins.** [](https://i.stack.imgur.com/32k9I.jpg) [source](https://i.ytimg.com/vi/WWBpfOCCqqs/maxresdefault.jpg) One of my favorite things in the Lovecraft stories is when they come across prehuman ruins. Mountains of Madness is one of the best but it is a recurring theme: cyclopean, impossible constructions which have weathered the ages because of their preternatural hugeness. So too your road. It is a built thing, of unknown antiquity. Sort of like the Roman roads must have seemed during the middle ages - or maybe more like the Giants Causeway. In places the traveler on this road will encounter other ruins visible below the water and extending downwards - presumably made by the same builders. In some of the constructions made by humans along this ancient way, the basements of the buildings make use of lower, deeper constructions encountered during the building. Some of these deeper pieces might be used as foundations. [Answer] **A natural road cannot form across a large sea.** I admire the creativity of the other answers, but I'm going to answer that it won't work. Atolls form in shallow seas. Splits form in shallow seas near the coast. Mid-oceanic ridges form in the middle of the ocean and never *across* a sea, and their crest is too rough to be reasonably called a "road". Whatever its origin, [Adam's Bridge](https://en.wikipedia.org/wiki/Adam%27s_Bridge) mentioned in the question is in a shallow sea, too. Large seas tend to be deep. Kilometres deep. Atolls and splits won't work. Your best bet would be a chain of volcanic islands, like the Aleutian islands:  Aleutian islands. Source: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:AleutianIslands.jpeg). however, I'd consider it a stretch to call this a "natural road" with small gaps. The mountains are pretty high above the water (or erosion and weathering will submerge them soon) and therefore many more than a few kilometres wide. You may be able to reduce the gaps but only so much. Realistically, you'll end up with a peninsula like Kamchatka, not a "natural road" that is at most some kilometres wide. It won't be as narrow as an atoll or a split, not in the deep sea. [Answer] Just off the coast of North Carolina (USA) is an island that has a lot in common with what you're asking for. This is [Hatteras Island](https://en.wikipedia.org/wiki/Hatteras_Island), a gigantic pile of sand that is about 50 miles long, but only a few tens of meters wide in the narrowest spots. Most of what I know is because I have family on the island, so I don't have a good understanding of the science behind how such a thing would form, but I'll try to detail all I know and can find quickly here. The island is made entirely of sand and sea shells, and is pushed around by the Atlantic ocean currents (especially the Gulf Stream, just off shore). There is no naturally occurring rocks (according to my family, I can't confirm this). You can see an example of a narrow spot [in this Google Maps image](https://www.google.com/maps/@35.278167,-75.5063322,13.21z). The strip of land just north of Buxton is the narrowest I can think of. Just East of Highway 12 is a large hill running the length of the East coast of the island. Barges dredge up sand and dump it all there. If you stand on this hill on that strip shown in the link, you can easily see both shores. Its weird to think you can walk from the East coast to the West coast of an island 50 miles long in less than 5 minutes. [](https://i.stack.imgur.com/g5tvN.jpg) The whole island isn't like this, though. Much further North in Kitty Hawk (where the Wright Brothers had their first powered flight in 1903) is much wider, though it maxes out at <5 miles. I don't have an exact figure here. There are also a few spots, further north, that are not connected year round. Past hurricanes and storm surges have blown through the sand completely, and whether the north and south half of the divide are connected depends on whether it is low or high tide. Bridges have been built over these areas. While the exact borders of the island are always changing, the existence of the island seems to be stable. It has been continuously inhabited since before the days of European settlement in the Americas, and according to [this source](http://web.utk.edu/~ctmelear/ossabaw/LeggettVestWilliams/N_Vest1.html) talking about the formation of barrier islands, it seems like the island has existed for thousands of years. I don't have time as of writing this to look up a detailed explanation of how barrier islands form, but I'll be happy to link to one if someone else can find it. New islands and features of the shoreline come and go. [A new tiny island formed from 2016-2017](https://www.livescience.com/59786-speed-of-new-island-growth-space-images.html), with the bulk of it happening in only a few months. This gives you lots of options for temporary land masses and shoreline features. Despite this, the sand is safe to build on. Several towns exist on the island, though many buildings (mainly houses) must be raised up on stilts so the hurricane floodwaters can go under them. There are buildings a few hundred years old that have been lost to the sea due to the changing shorelines, but if you build far enough from the shore in the thicker places, you can expect the building to not be washed away for decades or centuries. It does differ in a few key places from what you're asking about though. It is 1/10th the minimum size range you ask for, and I don't know how much the concept of barrier islands can scale up. The chain of similar islands connects at both ends to the USA, and seems to rely on having an ocean on one side and a relatively calm and closed off body of water on the other, so it wouldn't be good for bridging two continents as you want to do. It might work as a practical bridge if the route from start to end on the mainland has a difficult obstacle, such as mountains, a wide and fast river, or a gigantic swamp. It would be hard to have a paved road without modern technology, as [large dredging boats](https://outerbanksvoice.com/2017/05/23/where-are-they-working-on-beach-nourishment/) are used to protect beaches, towns, and certain sections of island (including the main road) from erosion. There is no reason the route can't still be used though, as people lived on it for hundreds of years before a paved road was built. [Answer] I'll preface this by saying it may be a little farfetched; I'm not an expect in geology by any stretch. Imagine a large basin sitting below sea level, but barred from the nearby ocean by a natural dam. Over time, the dam develops a number of breaks from the constant pounding of the tide, allowing rivers to form across the basin. Over more time, erosion eats away at the softer layers of rock in the basin. In a fluke of geography and volcanic activity, the resulting formations create a series of [natural arches](https://en.wikipedia.org/wiki/Natural_arch) that can be strung together with some ingenuity and excess building materials. Eventually, the wall holding back the ocean breaks, flooding the basin. We're then left with all the arches that appear to be small strips of land above and below the surface of the water. The constant ebb and flow of the new tide will rapidly deteriorate this geological phenomenon, however. Still, it doesn't take much to extrapolate the possibility from the [Azure Window](https://en.wikipedia.org/wiki/Azure_Window): [](https://i.stack.imgur.com/vTnkD.jpg) [Answer] Two separate seas eroding a narrow connection between two landmasses over time could create something like this, particularly if the connecting land is a softer rock. [Answer] It might be a bit of a stretch to suggest it created a path that long, but the process that is believed to have formed the [Galápagos islands](https://www.geol.umd.edu/~jmerck/galsite/research/projects/leonard/Geospot.htm) would probably work. Basically there is mantle plume that is stationary beneath the tectonic plates and the heat from this plume creates volcanoes above it which eventually become a chain of islands. Given long enough this chain of islands could stretch right across a sea or ocean. It wouldn't be anywhere near as thin as you want, but you could use erosion and maybe a sea level rise if you really wanted to make it quite narrow. As for the science... the downside is that the Nazca plate which the Galápagos islands are on is estimated to move 5cm a year so to reach your minimum of 500km you would need 100,000 years for it to form. Not exactly a long time in geological terms, but a long time for the plume to be active and for nothing else to happen to break or disrupt the chain of islands. [Answer] A long time ago two continents merged in a continental drift. The region where they met was full of plains on both continents, and the plains were surrounded by plateaus. Where the plains met, an impressive mountain range was formed ([think of our world's Andes](https://en.wikipedia.org/wiki/Andes)). A billion years passed... And the mountain range thinned. Also, those old plains are now beneath sea level. Those hitherto plateaus from a billion years ago are nowaday's plains and around sea level. You may tailor that mountain range's altitudes according to your wishes. Do you want it to be all above water? Possible. Some parts underwater allow passing, though you may need boats or bridges at some points. If the pass is in a region where water gets frozen, you get two options. Either ice forms on winters and bridges gaps between sunken mountaintops, allowing full passage without the aid of boats/bridges only when it's cold, or that ice is permanent and the passage is always open by land throughout the year. [Answer] I would say your best bet would be a string of volcanoes along a fault line. The lava flow would spread out, and depending on the geography of the land, could be channelled into a road. You would need multiple volcanoes to get roads formed of that length. The good news is that volcanoes actually naturally form at or near fault lines. [Answer] **Exotic Coral** What if a coral-like organism grew especially well in the region where a river ran into the sea? Maybe it needs the nutrients from the river and something else (maybe the salt) from the sea. It forms a starter colony on either side of the river mouth. The colony directs the flow of water in more of a straight line than a delta, and allows the colony (in two almost parallel lines on either side of the flow) to grow out farther into the sea. As the colony grows, the column of water from the river continues farther and farther out. As the column of water is allow to continue mostly undiffused along this channel, the colony is able to grow and grow along almost straight lines. On top of these parallel columns of coral skeletons, colonies of other organisms grow, forming the base of the roads. [Answer] In the last ice age this was the terminal edge of one or more or perhaps even successive gigantic sheet(s) of ice/glacier which dumped enough material at the leading edge to create a ridge which was either large enough to be above water when the ice age was over. Or had reefs built on it and sand deposited etc,. over millenia and eventually became a causeway. Unsure if this is actually possible but a global iceage where advancing glaciers came from north and south and that is where they eventually crashed into each other and deposited their moraines. [Answer] Glacial tongue! Form a glacier between two parallel mountain ranges. Since there is stress on the ice when it leaves land and starts floating, the approach to the water needs to be a gentle slope. The general stability and length of the glacier then depends on the water and seabed. Traversing this bridge should be treacherous! ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 3 years ago. The community reviewed whether to reopen this question 1 year ago and left it closed: > > Original close reason(s) were not resolved > > > [Improve this question](/posts/12219/edit) Somewhat related to [this question](https://worldbuilding.stackexchange.com/questions/12129/what-would-be-the-impact-of-modern-program-and-laptop-being-dropped-into-world-w). Take one modern, new-off-the-production-line, Challenger II battle tank, and one time machine. To what war do you need to send this tank before it can really have a decisive impact on the course of events? For the purposes of this question, a *decisive impact* is defined as anywhere from eliminating a major battle in the war to changing who wins the war. Killing one extra opposition soldier does not qualify, the resulting effect on the war is too minor. For example, I imagine it wouldn't have much impact in WWII. The level of technology then wasn't so far back that the tank couldn't be destroyed quickly. OK, it might take out a few more opposing tanks, but that's not a *decisive impact* as defined above. You can assume a full resupply of ammunition and fuel (*only* ammunition and fuel) every week. In other words, **when is the last war that could be significantly changed by the addition of one modern tank?** [Answer] Honestly, I think that a modern Main Battle Tank could have been a game changer in World War II, despite your concerns. Generally, the German Tiger Heavy Tank is regarded as the toughest tank from that era. However, comparing the Tiger to a Challenger II is, to quote a blogger, 'like comparing a Model-T to a Porsche for a race.' Tank technology was still relatively new as of World War II, and they had a lot of problems. For example, most WWII tanks were completely helpless if they hit a muddy field, and some could easily get stuck on trenches. A Modern Main Battle Tank doesn't generally notice such minor inconveniences. Armor and weapon penetration has advanced by great leaps since World War II. The main gun on the Tiger, generally regarded as the most formidable tank cannon in the entire war, firing armor piercing ammunition, was rating to be able to pierce 171mm of steel armor at 100m. The Challenger II's armor is classified, but it is said to be more heavily armored than the US Abrams. The thinnest armor on an Abrams is 600mm, and is made of an armor that is suggested to be twice as tough as steel. Even at point blank range, a Tiger would be incapable of cracking the armor of a Challenger II. Conversely, the main gun on a Challenger would hardly notice the armor on a Tiger. I couldn't find specifics on its range, but it is said to be at least as good as an Abrams, if not better. And an Abrams can reliably swat targets at ranges greater than 2.5km. The Abrams uses a smoothbore cannon, the Challenger has a rifled cannon...thus it can safely be assumed that the Challenger has superior range and accuracy as compared to the Abrams. At 2.5km range, a Tiger's gun only had about a 30% chance of hitting a target, and the shot had lost so much power, it had negligible penetration capabilities. Add in that the Challenger is faster than the Tiger, despite being heavier and much more heavily armed and defended, and has 4-5x the travel range on a single tank of gas...and you are dealing with a tank that would be functionally invincible in WWII...especially if your weekly resupply included spare armor to replace any bits that got dinged up by enemy fire. Simply put, a Challenger could lay waste to an enemy tank squad before they were even close enough to reliably hit it, shrug off their fire if they did get in range, and outrun enemy tanks if necessary. And, of course, modern shells pack more of a punch than WWII shells do, so its fire would do a lot more damage, and be massively more precise (thanks to modern computing systems handling the targeting for you). So, if you can see the enemy command post, the Challenger can probably wipe it off the map. So, while the Challenger would be functionally unkillable versus WWII armament, the real question is this: Can a single 'irregular' unit change the tide of a war? The answer is 'if you sent it to the right places, yes.' And if you have foreknowledge of how battles will play out...imagine landing an unkillable tank on the beaches at Normandy. Or rolling it into the middle of the Battle of the Bulge. It would take VERY careful planning, because once the enemy determined that they couldn't *kill* the tank, they would make plans to work around it. Bait it off somewhere it won't be useful in the battle...distract it...blind it...etc. Again, with proper planning and management...definitely possible to make a huge difference in WWII...but if you don't deploy it to the right places, it might be making a difference in battles that don't matter. [Answer] This almost seems silly. Quick look at the Challenger II's weapons: * Main cannon This is of lesser use as it's ultimately an anti-tank weapon and we're taking it to times where anti-tank isn't really a requirement. This would have some pretty impressive effects when targeting castle walls. The range on this puts any form of ancient artillery to shame and it's accurate enough that targets like 'enemy general' could easily be obtained and eliminated with a high explosive round. Limiting factor here is 49 rounds is the standard carry out * L94A1 chain gun This is the silly weapon. Up until the development of tanks, there is very little out there that has the ability to stop one of these rounds. Enemy infantry and cavalry would be mowed down incredibly quickly. Carries some 4200 rounds. * L37A2 (GPMG) machine gun This is an optional mounted remote device, fits into the category above. Range... I doubt roads are too considerable, at least not ones this tank wouldn't rip to pieces. Gives it about 250km. I'm actually having problems finding an example of a single battle that this tank wouldn't have a profound impact on up until the 1900's. There are a few where the number of troops involved is high enough that the tank itself wouldn't win the battle, but the tank would skew the battle heavily in a few manners. First is morale: the effectiveness of this tank is such that it would induce heavy fear in an enemy (and probably be referred to as magic). Second is its ability to launch a precise and deadly strike from a huge distance, if this is used to hit strategic targets (enemy generals for example), then the tank could cause such chaos that it could potentially change the tide of a battle (or war) from a single well placed shot: figure out what section of a castle houses the king and take it out with a single well placed blast from the main cannon. Imagine a Roman legionairre in Testudo formation: they are heavily shielded and nearly immune to enemy fire. Immune atleast until their unit is hit by a single high explosive round from 5 km away that obliterates the unit. Imagine being in the Testudo next to the one that just went up in a fiery hell and tell me you wouldn't drop your useless shield and run. The largest cavalry charge in history (in a single charge) was (according to wiki anyway) 3000 heavily armoured polish lancers and german/austrian knights towards an ottoman force during the siege of Vienna. This single tank would then have to average 12 bullets per kill to eliminate the charge entirely by itself with just its machine gun (add in as per comment, I don't think the main battle cannon would really be needed vs cavalry). Actually, the size of the forces involved in the battle of Vienna might be high enough that the tank wouldn't be able to win the battle singlehandily, but it could have stopped the charge that routed the ottomans in its path and changed the outcome of that battle (if the ottomans had the tank to open up the walls at vienna, the city would have fell long before the charge happened anyway) But you mention war and not a single battle. If you consider the Golden Hordes invasion into Europe a single 'war', then this tank might not have had that much of an effect simply due to its range and ability to get into a battle. Mongols on horseback could out maneuvered the tank on these vast plains and left the tank unable to directly engage and involve itself in a fight. The Punic wars between Carthage and Rome was heavily fought at sea, so there might be a pretty ready instance where one side having a tank might not have a huge advantage. If the tank was parked in Carthage, it could have prevented the Romans from ever sacking the city of Carthage, however the Romans could have annexed most territory (Iberian Spain and Mediterranean islands) but never actually take Carthage. I guess there is technically an instance where the tank might not have impacted the outcome of the war? If the Aztec possessed the tank, they could have really easily stopped one of their great cities from being razed by the Spanish, but the spanish ships could have easily avoided the one city that possessed the tank and hit other ones instead. Does this count as not being able to impact the outcome of a war? **Just to add:** The potential of the tank and its main cannon to become a battlefield assassin of sorts would immediately impact history. Napoleon is a safe 5km away from the frontline and giving his orders, until a high explosive round comes from 8km away and ends the general. Imagine if General Lee on the first day of his Seven Day Battles rode up onto a hillside to survey the battle before him and was struck by an incendiary round. Generals in modern warfare vs tanks do not take front row roles in battle just for this reason: this tank engaging in any battle where the general is actually on the field has pretty much free ability to snipe off a famous general **added to the comments:** I don't believe there is a reliable method prior to WWI where this c2 tank could be disabled and taken out of combat that isn't related to the C2's supply chain. If you assume this tank is part of an army that it's supporting, then the tank will have some degree of protection on its flanks or when its crew is resting. Pre-1900 a tank wasn't known and weaknesses such as targeting the treads wouldn't be well known (and even then, the c2 has most of its treads armoured and not easily seen). There is the potential for a lucky cannon shot, but the C2 completely outclasses these cannons for range and accuracy so the opportunity for the lucky cannon shot is minimal at best. I'd suggest a 1600's cannon fire could directly strike the c2 at a 1km range and do minimal damage at best, maybe a loud clang? The first strong resistance this tank could potentially meet is WWI: by then a tank wasn't a completely foreign concept and a few of its limitations/weak spots could be known. Additionally, the armaments this tank has were in use by WWI (admittedly in their infancy), which means opposing soldiers are already expecting machine gun fire and heavy cannon fire and are taking means to protect themselves from it such as digging in and spreading out, unlike previous conflicts where this tank could just open up with its machine guns into the middle of tightly packed troop formations that have no clue whats coming at them nor how to dig in and defend vs it. I would also suggest that WWI artillery was in heavy enough use that enough concentrated fire from artillery and mortar rounds would be the first counter that could potentially disable this extremely advanced tank from a combat point of view Contrary to Guildsbounty, I don't agree that this single tank would be a game changer in WWII, except in some very specific scenario's. WWII saw much street to street fighting and in an urban environment the possibility of infantry attacks that knew how to disable a tank (sticky bombs) was a much more real possibility. Even artillery would stand a chance in disabling this C2 during WWII. Later in the war, a few T-34's using ramming tactics, or a direct strike from a couple of Stalins Organs (Katyusha rockets) could put a relatively quick end to this advanced C2 tank. [Answer] Air power superiority would probably make the biggest difference in any past war. A B-2 Spirit would be able to fly over Germany without being seen on radar, pinpoint bomb all kinds of strategic targets, and be gone leaving nothing but destruction and confusion. Plus the recon ability would be huge. An A-10 Warthog would make short work of cavalry, knights, infantry, and anything else. William Wallace would be on the throne of England within a week. An Apache helicopter would possibly be the most terrifying thing ever a hundred and fifty years ago during the American civil war. Nothing could touch it. Sorry, got a little carried away. My answer is air power, any war before the Korean war. [Answer] As an earliest bound, one modern tank would obviously have made a difference to the [Anglo-Zanzibar war](http://en.wikipedia.org/wiki/Anglo-Zanzibar_War), which was in 1896 and lasted for 38 minutes. It seems unlikely that a handful of small 19th century warships could have survived an artillery duel with a Challenger II. This is really a question about what are the *smallest* recent wars, small enough for one modern tank to make a difference, and they don't come much smaller than the Anglo-Zanzibar war. [Answer] Certainly Waterloo could have been won by a single tank if it went in on the French side. As long as the TC (Tank Commander) managed to keep from getting killed by a stray bullet, a flank attack along the reverse slope of the ridge along the Ohain road would simply have rolled up the British squares. The whole battlefield was only about 2 1/2 miles wide, so a sweep would have taken less than 1/2 hour. Then reverse direction and do it again. Using the main gun on horse-drawn artillery positions is real overkill, but a useful way to make noise, and a useful precaution against some cannon-cocker getting really lucky and damaging a tread. Even if the tank ran out of ammo (and it would) it could simply run over any formation that tried to fight. In Patton's words, "grease for our treads". One of the first lessons out of WWII was that flesh and blood, including cavalry, are simply useless against armored vehicles. I'd guess the big trick would be to do it in such a way as to not panic the French as well. Once you get to, roughly, the American Civil War, things start to get harder. Defenders were learning to dig in, and battlefields were getting much larger. [Answer] Changing a battle is probably not too hard, but a whole war? You'd probably have to go back to a time when studying strategy wasn't common for the military, because any general worth his salt would be simply forming strategy around it as much as possible. A tank is powerful, but it has limitations - it can't cross rivers or forests easily, it can only be in one place at once, it can't defend or take an entire city, etc. Any particular battle it could be decisive, but a smart general would simply divide his armies up into smaller units acting more independently, so that the value of a single superweapon would be minimized. [Answer] Prior to World War II, your tank would have undisputed supremacy over the portion of the battlefield it could reach: between speed and armor, any weapon that can be aimed fast enough to hit it would be unable to damage it, while the tank's weapons would be able to defeat anything but the heaviest of bunkers. However, there's only one of it. This means the tank's influence isn't so much a question of *power*, as one of *scale*. It doesn't matter how powerful something is if it's in the wrong place. The [Challenger II](https://en.wikipedia.org/wiki/Challenger_2) has a cross-country top speed of 40 km/h and under your rules, an operational range of 500 km/week. It is further hampered by slow communication: prior to World War II, most tactical communication was limited to the speed of a horseback messenger. Looking at historic records, your tank would have been decisive in most single battles prior to the Napoleonic Wars, with the main exception being combat in mountainous or heavily forested terrain, where the tank may not be able to reach the battlefield. The scale of warfare changes with Napoleon, though: it doesn't matter that your tank could single-handedly defeat Wellington at [Waterloo](https://en.wikipedia.org/wiki/Battle_of_Waterloo) if you exhausted your fuel holding off the Prussians at [Ligny](https://en.wikipedia.org/wiki/Battle_of_Ligny). Similarly, the ability to turn the tide at [Aspern-Essling](https://en.wikipedia.org/wiki/Battle_of_Aspern-Essling) doesn't matter if you're busy chasing Wellington around the [Iberian Peninsula](https://en.wikipedia.org/wiki/Peninsular_War). By World War I, your tank is no longer decisive on any but the local tactical scale. It doesn't matter that you can punch through the German lines unopposed at the [Somme](https://en.wikipedia.org/wiki/Battle_of_the_Somme): with conflict extending along 30+ miles of front, you can't make a big enough hole to matter. By World War II, you don't even have local superiority. You may be able to take on a dozen Sherman tanks and win easily, but without air cover, a pair of [P-47s](https://en.wikipedia.org/wiki/Republic_P-47_Thunderbolt) could tear your tank to shreds. [Answer] There's one aspect of this question that seems to have been ignored by most of the answers so far... We're talking about going back in time to alter the course of wars. So arguably any well recorded war could be massively impacted, if not won or prevented altogether. In most cases you probably wouldn't even need heavy weapons. All you need is a really good historical record and some careful planning. Think about it like [the proverb](http://en.wikipedia.org/wiki/For_Want_of_a_Nail): > > For Want of a Nail > > > For want of a nail the shoe was lost. > > For want of a shoe the horse was lost. > > For want of a horse the rider was lost. > > For want of a rider the message was lost. > > For want of a message the battle was lost. > > For want of a battle the kingdom was lost. > > And all for the want of a horseshoe nail. > > > You don't need to send a modern tank to [Waterloo](http://en.wikipedia.org/wiki/Battle_of_Waterloo) or to [The Battle of the Bulge](http://en.wikipedia.org/wiki/Battle_of_the_Bulge), you just need to look for a soft target/event that preceded those battles. Don't send your time machine back to Normandy on [D-day](http://en.wikipedia.org/wiki/Normandy_landings) send it back to the [Branau am Inn, Austria, on April 20, 1889](http://www.biography.com/people/adolf-hitler-9340144#early-years). [Answer] **Your title question and your concluding question are quite different, and it depends.** > > In what war would one modern military vehicle make a difference? > > > First, many small things "make a difference" and these combine to lead to the outcome. Sometimes, a single contemporary tank or a handful of commandos has made "a difference". When you ask "would ... make a difference" though, while any time-travelling technology would make some difference, what that difference would actually be, depends entirely on the circumstances of what happens to it. This is an old type of fantasy question, and it tends to imply many assumptions in order to indulge the question, which ignore the kinds of questions which would *actually* determine the outcome. I.e. these questions tend to be imagining history as it was, only a Challenger II lines up with Napoleon to help him win at Waterloo, and the crew speaks French and the French army isn't utterly confused by this, and the Challenger II crew knows what is going on and what to do, and nothing breaks down, and the enemy army doesn't just panic and hide until they figure out what's going on, and then have a spy assassinate, bribe or seduce the wizards running the magical war engine. **The "realistic" answer is you would probably be distrusted and captured before getting to join in a battle.** **Even assuming that the people operating the tank are all linguist/historians who have a master plan for joining one side in the war without being captured, and all goes well, the next major deciding factors realistically are going to again be not-very-fantasy-soothing considerations** like fuel and ammo limits, malfunctions and repair, lack of roads, breakdowns, and the use of improvised explosives, fire and smoke, or other mundane obstacles. Also the enemy army is probably going panic and rout, and though you can can probably turn what was a pitched battle into a rout, what historically was the pitched battle may turn into something else as the victims try to understand what happened and do something other than face your tank in battle. **So it's impossible to say what "would" happen. Something unpredictable. In a recent enough war (as far back as World War II), it would just tilt the scales in one battle until something immobilized the tank or it ran out of fuel or ammunition.** After all, in World War II, there were many cases where one side had severe armor superiority. Often one side had no good way to defeat enemy tanks, and/or had no tanks of their own. It was a key advantage, but not always decisive, even for relatively small battles. The Challenger II is extremely powerful, but it's only one tank, with limited supplies, and it can be immobilized by mines or high explosives or abatis or a lucky HE round. The chaingun is wicked, but it and the main gun could both eventually be disabled by even 1939 weaponry, even if the tank's armor couldn't be penetrated. Even in World War I, the Challenger II might do a lot of damage in one battle, but many conventional weapons also did a lot of damage in World War I. Particularly in the trenches on the Western Front, the best the tank might do would be equivalent to one successful attack, or one failed attack by the enemy, but then your tank would presumably be used up. The least it might do is get immobilized by the ridiculous terrain and/or all the mines and high explosives, before it did a whole lot of damage. Maybe if you also brought-back-in-time maps of the other side's rear deployments on a certain date (another possible time travel question), and drove over and blew up all their ammo dumps or something, you might be able to set up your allies for a decisive breakthough. As for your concluding question: > > when is the last war that could be won or lost by the addition or subtraction of one modern tank? > > > Again mincing words, I would say **you could maybe possibly tip the scales of World War I if you planned quite well and acted unconventionally**, as I suggested above. Before then, I think you *could* turn the tide of just about any one battle before World War I, assuming you overcame all of the situational obstacles and achieved surprise. You might even win two or three battles, as most enemy conventional weapons would be useless against the tank, and very vulnerable to them. But sooner or later, you'd run out of supplies, break down, or your enemy would wise up and not fight you in battle at all, choosing intrigue of many sorts until they removed the threat or its crew. Before the 1800's, even a brilliant historian/linguist tank crew will have a lot of problems even making friends with their desired allies, as you'll be trusted perhaps less than we would trust space aliens with flying saucers saying they are here to help us atomize our enemies. Less, because of the fantastic context shift - for example if they are Christian, they'll probably think you are devils sent from Satan. Anyone who allies with you may be considered to have made a pact with the devil, be excommunicated, etc. Any powermongers you ally with are liable to scheme against you, and if they don't, some of their friends or enemies will. They'll feed you drugged food and it'll be interrogation time, or worse. [Answer] I am going to assume that the Challenger II is close to on par with the [Abrams](http://en.wikipedia.org/wiki/M1_Abrams) tank. In the Iraq war they were using [T72](http://en.wikipedia.org/wiki/Challenger_2)'s the Abrams cut through them like butter. Going back to WWII I'm not sure if anything short of a direct howitzer round could do much to damage it. If it had a steady supply of ammo and fuel and a good mechanic, it could devastate the enemy in any battle field. I've heard of 1 depleted uranium round going through 2 Bradley fighting vehicles. WWII tanks are pop cans in comparison. 1 Abrams round might be able to kill 3-4 tanks if they lined up right. So what I'm saying is that a single Abrams tank could make a huge difference even during WWII. So any war before that that had battle fields (not Guerrilla warfare in jungles or such) it could be the winning card. Especially if the tactics were sound. Oh, ya, on top of that the Abrams can go over 70 mph, that is faster than most any vehicle during WWII other than planes and race cars. EDT: according the comments, many seem to assume I think 1 tank could have won WWII single-handedly. I never said that. I said it could have made a significant difference at almost any battle, especially if the tactics used were good. Given enough time any enemy will find a way to disable or work around a weapon. The point I was trying to make is that it could make a real difference in a battle as late as WWII so any war earlier than that it could be the 'magic' bullet, as long as it wasn't a Guerrilla action. [Answer] A single Challenger II tank along with vast supplies, stationed in the city of Liège as of July 1914, could have made Germany surrender by Christmas. This would effectively have killed the Stab-in-the-back myth, prevented WW2 in Europe, along with the Holocaust; the Ottoman empire would not have been split under the British, most Jews wouldn't have emigrated to Eretz Israel, which would have prevented five wars and over a million displaced persons in that part of the world alone, and possibly the Monroe doctrine would not have been phased out. So, if you can put it there, please do it. I'd say, chances that history gets any worse are near zero. [Answer] A tank might be the wrong vehicle. Maintenance-intensive and optimized to go against a few hard targets. How about a mobile radar on a hill over Pearl Harbour? A fast attack craft scouting during the Battle of Jutland? A drone over Gettysburg? Of course all those force multipliers assume that the time traveller can communicate with the side he or she wants to support. If you have that communication, how about a supply truck loaded with digital radios, laser rangefinders, and night vision systems? [Answer] I would perhaps choose a small modern destroyer to remove the Union blockade, but a Challenger tank joining the charge at Gettysburg and the march on Washington afterwards and todays rednecks would drive around with Stars and Stripes on their pick-ups in New England. The main gun on the tank can use high explosive ammunition, taking out the Union artillery in a few minutes and the machine guns will mow down the entrenched Union soldiers by shooting through any cover they have. By using the fear factor and a very restrictive use of ammunition the tank can be devastating. Fuel is a problem, though diesel could be produced, but ammunition will run out, and will be very hard to re-stock. (EDIT: not only should I read the question, I should reread it, sorry). [Answer] I disagree with most of the other answers that imply it would make a big difference. 1.) If you send it back prior to WW2 you will have big problems to get appropriate fuel. 2.) In WW2 it will make a big difference until the munition is depleeted. Then it will only be a moving bunker. 3.) It will be nearly impossible in any past war to get spare parts. **EDIT:** Even with resupplying once a week with fuel and ammunition point 3 is still valid. And resupplying fuel once a week(I assume here an amount of one full refill) will let most modern tank move for about 9-10 hours. For example the Challenger 2 has a maximum range of 279 miles with one refill. Also the Challenger 2 has only 50 granades loaded so after firing 50 shots it need to wait for a week to be of any use again(I also assume one full refill of ammunition once a week). The lack of a constant supply of fuel will decrease the effectivity of the tank most. The tank will always be in short fuel supply to follow the frontline. [Answer] For some reason I have thoughts of King Harald mowing down Normans in a 50 Cal equipped Hum Vee back in 1066. With a Cigar in his teeth of course. I'm quite sure it would have a range longer than a bow and arrow. However his eyes would still be exposed :-) No Magna Carta would have been written, no Doomesday Book, there may have been no industrial revolution, the Catholic Church may have collapsed due to rebellion, the hundred years war would have started a couple of centuries early in fact the entire history of the world could be completely different from 1066 onwards and maybe not for the better either. For a start I wouldn't be typing in English as we know it and where I live would be called something completely different. Go back even further and prevent the Romans from Wiping out the Druids at the battle of Anglesea with an A10 Warthog, the economy of the Roman Empire would have collapsed possibly leaving a peaceful hedgemony covering most of Europe run by Druid Lawgivers. What would happen then is anybodies guess but just in case someone changes history I'm going to practice writing in Ogham Script :-) [Answer] If you are looking at altering the course of a **war** I think you have to go further back than say altering a single battle. An M1A1 Abrahms Tank is currently best in use tank tech, its armor and weaponry are second to one. A tank's power is derived from its weaponry, armor and mobility. Disable one, and the rest are useless. The "softest" target on a tank has always been its tracks. To guarantee a single tank impacts the course of an entire war it has to survive its battles. For a tank to survive I think you have to go to a time that is pre cannons. While a single cannon likely wouldn't do any significant damage to the tank, a battery of cannons could certainly disable a tank in short order, keep in mind ship based cannons as well. A few good shots that hit the tracks and a tank becomes disabled and can then be cleaned out...and thus become useless. I would put the date where a tank could *potentially* win a war by itself at somewhere around 1700. [Cannons were used well before that date](http://en.wikipedia.org/wiki/Cannon), back into the 1400's, but were large, slow, and difficult to aim for centuries. That would mean this would be the last batch of major wars a tank could win, but a guarantee in war is a proposition that is only guaranteed to fail, so again, even in these cases it may not alter them completely:  Another thought comes to mind. **Basically any explosives can disable a tank** add something sticky attach it to the tracks...bam. No more tank. Also tanks can get stuck, and tanks would be far less useful in battles where the terrain is uneven or forested and would have significantly less impact. [Answer] If given a chance, I would have taken the Challenger 2 tank to the year 480 BC in Ancient Greece. Cause there would be one king who would have been particularly happy for having that bad boy with him alongside his trusted 300 men. Just imagine the look on Xerxes's face. King Leonidas would order to load the 120 mm L30 and say ALPHA - MIKE - FOXTROT.. As a result -- i. Battle of Thermopylae won in 1-2 Hrs. ii. Leonidas would go into the warm embrace of Gorgo. iii. Dilios would still have his eye. iv. Persians wont dare to step out of their homes. v. Greeco - Roman civilization would be the dominant civilization and with the military might of Sparta who knows what could have happened. Now for those critiques who might point out the mobility and terrain of Thermopylae, I am pretty confident that the tank would do perfectly well by just sitting around and picking of hoardes of enemies with the HE rounds / Incendiary (White Phosphorus... oh yeah) rounds. If the enemy got closer we can give hell using the Chain Gun or Optional GPMG. [Answer] 1 Abram's tank sitting in Long Island at the beginning of the Revolutionary war. With range enough to sink the British fleet sitting off the coast. With all ships sunk (probably in minutes), no weapons and a handful of half drowned survivors the war would have almost certainly have ended even before it began. The victory would have also rallied the colonials and presented greater resistance to any attempts to try again. Picture the devastation to the British army when they lined up in battle formation and were cut down in minutes by the 50 cal. machine gun. For the sheer mind changing power of that type of event it would have made all the difference. Of course without having to fight for the new idea of a democratic republic it probably would have floundered and failed a few years after it began. It is that distance from the struggle that now has us floundering and failing today. We value what we pay for and value most what we pay most dearly for. [Answer] In almost any military engagement in modern history, placing any military technological advancement from a future war on the battlefield of the older one would make a significant if not decisive difference. In your case, placing an Abrams, Challenger or T-90 on practically any battlefield that existed before their development (pretty much anything prior to Vietnam) would have been a game-changer. Guildsbounty's answer dealing with the Challenger or Abrams on a WWII battlefield adequately covers that, though a 109 or P-51 with a 250-lb bomb might pose a threat, as might man-portable anti-tank weapons like the Panzershreck, and the tank's crew would have to stay buttoned up practically the whole time as the only real weapon any prior army could field would be used to target exposed crewmembers. In any land war prior to the Second World War, a modern main battle tank would be able to traverse the battlefield almost at will. However, the supply chain is a concern. The modern U.S. Army is about 20% combat, 80% everything else including support, supply and logistics. Plucking a fully-fueled, fully-armed tank off the tarmac of a FOB in any modern engagement and dropping it into any time period before its development would likely mean it cannot use any ammunition of the day, and at any time prior to the late 19th century, you wouldn't have access to any substance you could use as fuel (and a 60-ton, 1,500hp Abrams doesn't get great gas mileage). In anything after the turn of the century, you'll probably be able to fuel the tank with diesel or kerosene for the duration of a campaign (it'd be a thirsty girl but well worth it), but it would run out of ammo eventually. In any prior conflict you're probably only going to get one or two battles out of it before you're out of gas and the tank is a dead lump on the field. The ammunition a modern tank carries is also a concern. Most modern tanks carry a load of main gun shells mixed between kinetic penetrators (essentially a heavy, hard non-explosive shell designed to knock holes in the target) and a secondary round usually designed to defeat armor or hardened fortifications in some way (HEAT rounds are a shaped charge that produces a jet of molten copper to penetrate armor, while the HESH round is a thin shell over a big lump of C-4 or similar plastic explosive with a very short delay fuse used to deliver a catastrophic explosive impact to hardened surfaces). HEAT rounds are most effective against modern armor; anything on the battlefield prior to about WWI really isn't enough target for a HEAT round to be worth firing, though Greek and Roman phalanx maneuvers involving a wall of shields (and a ceiling against archers) would be very susceptible to a jet of molten copper and the blast wave of the shaped charge. In most other situations the kinetic penetrator would be the crew's bread and butter. HESH rounds would be more generally effective on older battlefields, especially against sieges of fortifications up to about the 17th Century, for the same reason this type of combat was eventually abandoned with the introduction of the gunpowder cannon at the end of the European feudal era. The most effective actual armament a modern tank would have in most older combat is the coaxial gun and any other mounted machine guns. WWI, and the eastern front of WWII, proved the horrifying effectiveness of the machine gun in the face of a wave of humanity; of the 50 million estimated killed in WWII, over 8 million were Red Army conscripts ordered to assault German positions en masse, often with only one rifle for every two or three soldiers as it would be wasteful for the weapon of a soldier killed halfway across the battlefield to go unused. Most pre-WWI battlefields would be a similar one-sided slaughter if even one pintle-mounted machine gun were brought to bear, to say nothing of the Abrams' two pintle-mounted guns (one .50-cal, one 7.62mm) and the 7.62 coaxial machine gun. Really, in most combat between the end of the feudal era and the advent of mechanized warfare, a modern main battle tank would be most devastating as a simple steamroller over enemy troop concentrations, coupled with a shield for troops behind. With a top speed of 35mph it could outrun (though probably not outturn) any advancing troops, break their lines swing around to one side and then flatten the enemy's artillery emplacement, then swing back to provide the spearhead of a column formation of friendly troops. It could allow the general on the side it was fighting to win the battle handily without the tank firing a single shot, instead using the tertiary features of its 60-odd tons of weight, 1,500 horsepower and armor plating easily outclassing anything an opposing army could field. [Answer] No wars would be 100% win for tank regardless of epoch/tech level. The more localized war is the more advantage side with tank would have. But as distances increase, so would tank's impact on the course of war decrease, simply because it can't be everywhere at once. A clever strategist can leak a false info about a high-importance target and lure tank away from real battle for long enough to win it the usual way. The longer war is, the less tank would matter as well. It would be worn down, lack supplies and with time people could devise more good strategies to block, evade or destroy the tank. No matter what era it is - tank will never be invulnerable. **Even the best modern tank can be easily disabled with simple, primitive and low tech trap available since stone age: a trap pit.** Once again, give a tank command a juicy target to chase, lure it into trap and pour some boiling oil down the pit to make sure those pesky soldiers won't climb out and figure a way to pull tank bank. The end. [Answer] If we went back to WWII with something like the Challenger or the Leopard II or the Abrams, they would certainly be a game changer; they could single handedly spearhead an assault or capture key positions before the enemy knew what hit them. Now do take what I say with a grain of salt, I do not have first hand experience with any armored vehicle (I have only read about the history on them) I'll be focusing on the Leopard II **Armor** Modern tanks have armor <500mm due to composite armor, nothing in WWII and before could penetrate or kill the tank (assuming we are talking about Tank vs. Tank). The best the enemy could do would be to immobilize it with anti-tank mines. **Weaponry** No competition. The Tiger 1, while has a fearsome reputation for it's gun, would simply be no match for the Leopard II along with it's modern fire control system. **Speed** Again the Leopard II wins, the Tiger won't be able to match it in any way. **Result** The Leopard II (or any modern tank) would quite certainly be a game changer to whatever front it was on, but one single tank was near irrelevant if we were to take into account how large in scale the entire war was. [Answer] It could decide any war by materializing directly above the leadership of one side during battle, so that the opponent could take advantage of loss of leadership. Or if it appeared with sufficient velocity, it could destroy a city or even a whole state. Eg. stopping Mongolian horde when they are in China by vaporizing east Asia would definitely help against mongols (but maybe the firewall running around world could pose some problems, so maybe a little less energetic event). If used as a fighting vehicle, it could win any battle - but run out of supplies. But it could help someone to conquer whole world, by reverse engineering the vehicle (and especially if crew would help). But tank crews are not technical/scientific geniuses. So some support vehicle would be better than an MBT (sending something larger and with wider skilled crew, eg. supercarrier, would be of course better). But the question is about Challenger 2, not the best vehicle for changing history. [Answer] As per the answers above, any single MBT is easily capable of turning the tides of a single **battle** that he gets thrown into, up until at least WWII. However, you wanted a significant impact on a **war**, so the logical answer is: Until the point where a single decisive battle would no longer turn the tides of war. Both World Wars were full of large, decisive battles that - by themselves - did not turn the war. Only the sum of several such battles eventually did. On the other hand, in ancient and medieval times, wars were regularily decided by decisive battles. There are a few exceptions (Caesars conquests) but until at least Napoleonic times, the idea of deciding the war in one important battle was strong, and held until it was soundly proven wrong in the trenches of World War I, where many generals and officers still believed in the one battle that would end the war. So, a few historical exceptions ignored, anytime until WWI you could decide a war this way. Afterwards, maybe you can depending on luck or strategy, but you are in no way guaranteed that outcome anymore. ]

[Question] [ **READ ME FIRST**: There seems to have been a great deal of misunderstanding stemming to equal parts from the words I chose for this question as well as the human nature of only seeing what one wants to see. In order to make the goal of the question clearer to the user I've spent some time investigating the English language and choosing the proper words accompanied by explanations. Emphasis is always mine. > > (*to*) [*butcher*](https://www.merriam-webster.com/dictionary/butcher) > > 1 : to *slaughter* and *dress* for market > > > Butchering means killing and cutting up an animal for further preparation of the meat > > (*to*) [*dress*](https://www.merriam-webster.com/dictionary/dress) > > 6 c: to *kill* and *prepare* for *market* or *consumption* > > > The process of dressing involves cutting away undesirable parts which can range from the lower intestines to specific parts of fat and sinew, etc. > > [*Primal Cut*](https://en.wikipedia.org/wiki/Primal_cut) > > A primal cut or cut of meat is a **piece of meat initially separated from the carcass of an animal during butchering**. Examples of primals include the beef round, loin, rib, and chuck or the swine ham, loin, Boston butt, and picnic. > > > --- > > *Everybody loves dragons. Dragons are super awesome!* Albert Einstein[citation needed] > > > As implied by the quote there's almost no fantasy world that does not include one or another dragon. Be it in the form of actual physical beings, raining terror from above; or as legendary tales of physical beings, raining terror from above in fairy tales. But there is one thing that bothers me: If dragons are an inherent part of a world... then why is there never any mention of how to prepare, [cook](http://www.thesaurus.com/browse/cook/verb) and serve them? Assuming dragons to be [house-high](http://cdn0.dailydot.com/uploaded/images/original/2014/4/27/DRAGONS_chart_1.png) fire-spewing flying beasts of ~~awesomeness~~ terror & destruction, there should be a fair amount of muscle- and fat tissue available for munchies1. Looking at similarities from our glorious world, it seems that lizards and other small scaly animals are most often [broiled](https://www.coloradohistoricnewspapers.org/cgi-bin/colorado?a=d&d=EVE19160908.2.42) or [fried](http://www.gourmet.com/recipes/1940s/1949/10/fried_lizard.html) which I assume is due to their small overall sizes. --- *Addendum*: After discussions on the chat and seeing it in many answers I feel obliged to provide additional detail on dragons in order to make the question less opinion-based1 > > *Every dragon belongs to the same family, but not everyone sees that* Confucius > > > Thus we this question is asking about what is commonly referred to as the *European Dragon*: [](https://i.stack.imgur.com/Lco5w.jpg) [greater resolution](http://orig08.deviantart.net/afc0/f/2013/039/e/6/anatomica_draconis_by_katepfeilschiefter-d4i7aq5.jpg) | Source: [Kate Pfeilschiefter on DeviantArt](http://katepfeilschiefter.deviantart.com/art/Anatomica-Draconis-272438285) The composition and structure of the dragon's scales allows them to conduct heat and radiate them from large surface area of its wings. The dragon's meat is not in any way *magically* heat-resistant. A dragon breathes fire in a similar fashion to a lighter; it sprays a combustible substance, stored/generated in a special organ, out of a nozzle located in their snout. The combustible substance is then ignited by means of creating a spark by rubbing special bones/teeth at each other when moving its jar. --- **Q**: What are the parts/cuts of the dragon's carcass? *Bonus*: How pleasing would they be to the palate and why? This question is asking about the *parts of meat* and similar that come from a dragon. The idea is to **name them** and **explain** why these parts have been made from this or that section by mentioning a **use** for them. This question is not about finding *1001 Dragon Recipes from Gramma Garnackle*. Although nobody will be angry at you including some recipes as long as you try to answer the question itself. 1Assuming dragon-hunters ~~aren't some jacka-~~ will not leave their kill to rot 2Also it seems that **not** including the [magic](/questions/tagged/magic "show questions tagged 'magic'")-tag is not enough to imply that the answer can be valid without any fancy fantasy writing; I enjoy reading a good made-up account, but the content must always come first. [Answer] It is a common misconception (likely spread by crafty, older dragons) that only young dragons are tasty. Much like their avian relatives (related via the dinosaurs), mature dragons develop a depth and richness of flavor much prized among those fortunate enough to survive to the tasting step. Their flesh has toughened during those centuries of survival, strife and magical combat, so older "stewing" dragons are used for soup or stew. If one has a large enough pot and heat source (volcano recommended), the white vs. dark dragon meat controversy can be sidestepped by cooking the whole thing and inviting nearby allied Shires to feast (*and* help with the ex-dragon cleanup; don't invite shirkers back for more.) The major difficulty is removing the skin and attached scales without totally trashing the entire courtyard. We find that a sturdy battleaxe, with a minimum of +3 enchantment is the best compromise. *This* is truly where those diamond hones you were given for St. Unpronouncable's Day come in handy. Use them; alternate sides consistently and keep the axehead cool with lots of water. Unless the enchanted axe is a veteran of such cooking, there's a slight danger it will become too excited by the prospect, overheat and loose the metal's temper. Don't let this happen! Re-heat-treating tends to remove the enchantment — an expensive mistake. Internal organs of note: The royalty will, of course, demand all of the heart. A smart kitchen staff knows what happens if they shave off bits — bait for next month's soup dragon. The gizzard should be processed by the chancellor of Coin and Jewels. Be very careful with the stomach, obviously. The Mages will want the liver, probably with onions. (*Pate d'Dragone* is a topic for another day.) The bones, once boiled clean are classic decorations for a great hall. Enough with the preliminaries — on to the recipe itself: Ingredients: * 1 stewing dragon (Approx 20 {Metric, please} Tons), viscera removed and handled as noted above, skinned with the bones as intact as possible. * Fresh, uncursed water to cover (Yes, don't even think about cooking dragon soup during a siege; won't work. Dragonburgers or dragon sloppy joe is more likely feasible.) * Two wagons (assuming a standard, two-ton wagonload) each of: + Carrots (the nice fat ones, well scrubbed) + Celery + Onions The seasonings: * Four stone-weights of sea salt, * One stone-weight of black pepper, * One barrel of Garlic, peeled, * A double handful of Bay Laurel leaves, * One handful of Dill weed (not the seed!) Simmer until tender, probably at least three days — leaving time to send riders to allied Shires to come party. Accompaniments: The recipe for a Dragon-sized Matzoh Ball is not yet satisfactory (heat transfer and texture issues), so we recommend noodles instead. Remember to add the noodles only in the last *SEVEN* minutes (so after the Nobles are all present and also *seated*.) Mushy noodles will just not do in dragon soup — people would talk... Hoping this is pleasing to Her Imperial Majesty, —P {Parfi of Roundhill} [Answer] Dragons are heatproof, you have to serve them raw. We're talking dragon sashimi here. It has to be fresh young dragon, no more than a few hours dead. Not some tough old elder dragon. Finely sliced on a bed of white rice. *(Please note: the question is now vastly different from the one this answer was written for which was about cooking and eating)* [Answer] The art of cooking dragons has likely not been well-developed, as cooking dragons requires you to produce a dead dragon, which is often the main conflict of the story. But supposing that you *could,* what would dragon meat be like? Poultry is known for producing two types of meat per bird: white meat and dark meat. The two have very different flavor and texture, and the reason that birds have both is because [their muscles get differing amounts and durations of activity.](http://www.livescience.com/32500-why-is-dark-meat-dark.html) In fact, [the amount of exercise a particular bird gets has a significant effect on the flavor and texture of their particular meat.](https://www.biggamelogic.com/ArticlesNews/tabid/136/articleType/ArticleView/articleId/459/Turkey-Myths-Facts.aspx) Breast meat is white and leg/thigh meat is dark, because chickens and turkeys spend more time standing and walking than flying. Their legs are designed for sustained use, while their breast muscles are designed for sudden intense use. But this is only part of the phenomenon. The white meat of wild fowl is much more similar to the dark meat of domestic fowl, because while there is no difference in the design of the muscles themselves from bird to bird, they use those muscles more frequently. But a dragon is not a bird. It would likely be classified as a reptile. So the meat would likely taste and texture more akin to alligator than turkey. The purpose of studying poultry is because it shows us pretty clearly that muscle usage can affect the flavor and texture of the meat. But in fact, [alligator meat exhibits the same phenomenon.](https://www.steaksandgame.com/exotic-eats-what-does-alligator-taste-like-15862) Speaking from experience, alligator tail tastes vaguely like chicken, but is much more tender and less stringy. Alligator is also low-fat, low-carb and high in protein. So what kind of muscle usage does a dragon exhibit? Unlike a chicken or turkey, dragons soar great distances, as their primary form of transportation. This is sustained use of the chest muscles, which would seem to imply that dragon breast would be dark meat. Neck and tail muscles are likely dark meat, as holding up the tail (while flying) and head require sustained effort. Dragons do tend to stand and walk when they come down to attack (which, traditionally, they are inclined to do). The legs and thighs seem like they would be dark meat as well. Of the two, dragon legs/thighs would be more characteristic of white meat, but both would likely be dark. But white meat enthusiasts may have hope in your world. If your world has dragons, it's not much of a stretch to also include wyverns, which have only two legs as opposed to a dragon's four. A wyvern would have the opposite situation of a chicken or turkey, flying the majority of the time and standing infrequently, supporting a large weight with little muscle. The result would be that wyvern breast would be dark meat while wyvern legs and thighs would be white meat. Should dragon/wyvern breeding ever become feasible and popular, we would likely find that the breast meat would become more similar to white meat, provided that they are confined rather than free-range (because really...) as they would not fly as much. But they would still be dark meat. We might also see that we've transformed domestic dragons into massive (that is, fat) monstrosities like we have with domestic turkeys. So to sum up the quality of the meat, **dragons and wyverns will both be similar to alligator, which is high in protein and low in fat and carbs, and tastes a little like chicken but is more tender and less stringy. Dragons will be all dark meat, with the legs and thighs being slightly more characteristic of white meat. Wyvern breast will be dark meat and wyvern leg/thighs will be white meat.** As for preparation, the above link ("alligator meat exhibits the same phenomenon") also mentions preparation methods. For the white meat (the tail on the alligator), they can be served in steaks or fillets, grilled or pan-fried. Speaking from personal experience, they're also delicious chopped up and deep fried. It can be further tenderized with a meat tenderizer. The dark meat portions of the alligator (the legs) are often served deep fried and tossed in sauce, just like chicken wingettes. The link also recommends grinding them up into sausage, mixed with pork or other meats. The ribs are also smoked, grilled or braised in an oven. Given that both are reptiles, the procedure for preparing dragon/wyvern is likely pretty similar. **If your dragons have scales, you'll need to scale them like a fish first. White meat can be served in grilled or pan-fried steaks/fillets or deep-fried bites. Dark meat might be best deep-fried or ground into sausage but of course anything you can make work will suffice.** And this is speaking personally, but I would find it appropriate and amusing, even if not for purely culinary reasons, to be served dragon prepared with spicy peppers, sauce or spices. [Answer] The main thing I want to point out is that dragon meat will be very low in fat. This is a very large animal testing the boundaries of what is capable of flying, so it can't carry excess weight. Due to its size, dragon meat should be processed in a manner similar to whale. If the dragon meat is tough and can not be cooked (credit to @Separatrix for that one), I would pickle or ferment it instead and let it age for a long time. In your situation I would research traditional Icelandic and Inuit forms of fermented and pickled whale. For methods that use a lot of oil or blubber in processing, I would substitute either pig fat or plant oils. If you do consider it possible to cook the dragon, your best comparison would be low-fat meat. Rabbit is an extremely low-fat meat. In fact, eating large quantities of dragon will probably cause [rabbit starvation](https://en.wikipedia.org/wiki/Protein_poisoning). [Answer] # Actually butchering a dragon Many speak of general dragon recipes, but not the general process of butchering a dragon. While this is okay for those who wish to simply boil, stew, grind, or even deep-fry the creature whole, it is simply unacceptable for purposes such as sashimi, steaks, and roasts, among similar preparations. The process will be broken down from selection to serving. ## Selecting your dragon The very first and possibly most important step is selecting your dragon. While anyone lucky enough to kill a dragon should experience the unique taste of generic dragon meat, if one is hunting the beasts for specific purposes, they should keep this in mind. Each variety has its own unique culinary uses. We'll focus on classifications, then types, then age. * Chromatic Dragons + Chromatic dragons are generally the best classification to use for general purposes and frying. Being generally weaker than equivalent dragons of other classifications, often very isolationist, and almost always evil, they are frequently the easiest to kill and the easiest to get away with killing. - Red Dragons, due to their fiery breath, often have a slightly sulfiric taste, but also a rather spicy and peppery one. They are best used for gumbos, curries, many Chinese-American dishes, and other foods that are traditionally spicy. They are also rather popular for kebabs. - White Dragons, being the endothermic sort, have a crisp, refreshing flavor, which has been described as slightly minty and almost chilling to the palate. I've heard it compared to a gingered pork in this regard. They are often used in many traditional Scottish dishes and are frequently added to various Japanese dishes as well. I personally find them perfect for carpaccios. A popular treat among street vendors is to take a White Dragon's unique neck spine, topped with a hunk of meat, and fry that in breadcrumbs, to be sold as a stick-included convenience food. - Black Dragons have a gamey, fishy taste, due to their seafood diet, and as such, are great for use in Oriental dishes and otherwise paired with seafood. When doing so, don't bother with lemon juice or similar acids, as black dragon meat is already highly acidic. Their signature frills are also excellent as a wrapping for haggis, dumplings, or sausage. - Blue Dragons are very dry and unappealing, and just as tough throughout the creature's life as the meat of the most ancient dragons of other types. Still, they are often eaten by desert peoples due to their convenience in locale, and their black bones ae prized by mages for construction of electricity-based spell focuses. As such, the skeleton is normally twice as valuable than the meat, which is usually sold cheaply enough for beggars to have after nobles have lapped away the organs. - Green dragons are generally avoided, due to implications brought forth by their preferred diets of intelligent humanoids. For those more adventurous types, though, they are similarly flavored to venison for white cuts and to snakes for dark cuts, often meaning the breastmeat and flanks are used for jerkies and patties while the tails are excellent bulk substitutes for any serpentine ingredient. * Metallic and ferrous dragons are almost always of a Good alignment and tend to have strict, interconnected hierarchies; not to mention, their hides are incredibly tough. This makes killing them a very dangerous prospect in regards to dragonkind and humanoids alike, not to mention preparation is incredibly impractical. They all have a dull, white-meat taste, not dissimilar to a chicken breast, and are often boiled whole due to superior heat distribution and said butchering difficulties. This makes them incredibly dry, bland, and flavorless; they are best used in stews and served to Anglican sorts for these reasons, were you to even want to kill and eat one. * Gem dragons have a similar problem to metallics, however can't even be boiled easily due to their tough, crytalline hides. The meat is also incredibly tough, and embedded with what some believe to be microscopic gemstones of the same type as their hide, making cutting one's mouth a frequent occurence. They're best just sold for scrap and not even attempted to be eaten. * Age-wise, dragon is generally more tender and flavorful among younger varieties, but much more complexly flavored among the older individuals, as some have pointed out already. Choose your dragon with this in mind. ## Cuts of Dragon We'll be working with this anatomy chart: [](https://i.stack.imgur.com/IpFa7.jpg) * The **platysma** (or neck muscle) is best avoided for consumption. A dragon's throat is covered in the incredibly dangerous, and more importantly, extremely unpalatable breath weapon compounds. + The **deltoids, biceps, and radials** are all tough, but flavorful, dark meats. The trapezoid in particular is good for cutting off chunks of roasting, smoking, or corning meats, as well as anything else that is generally cooked at low temperatures for long periods. + The **trapezoids** are similar to pork shoulders. A pulled pork-styled dish, nicknamed "lizard slivers", is incredibly popular for this cut, especially from a red dragon. + The **alopectorals** are, in essence, the breastmeat of a dragon. They're dry and fairly flavorless, but breading, deep-frying, or liberal application of sauces can all improve on the cut. + The **back abdominal muscles** are the closest thing to a tenderloin you'll find. Unlike many other creatures, the abdominals are actually the *least* used on the dragon(1), and as such, are incredibly tender and prized, yet are one of the most common meats. The best part is that there are eight of these per dragon, each around fifty pounds of meat. They are also unusually flavorful, due to containing the entirety of the dragon's fat stores. + The two **front abdominals**, on the other hand, are tough and fairly tasteless. + The **ambiens** are similar to beef rounds. They make excellent steaks, in both the tuna sense and the bovine sense. + The **latissimus dorsi** is a perfectly well-rounded cut, balancing tenderness and flavor for a perfectly prime cut best cooked rare. + The various wing muscles are extremely tough but rather flavorful, and best used for jerkies. Don't bother with the actual wings, just the muscles connecting them to the body. + Finally, the **erector cadue**, or the tail, is a very versatile meat, good for roasts, steaks, fillets, stews, kebabs, and all sorts of other uses. It's also the second-largest section and the very largest cut, containing about ten percent of the meat on the dragon. ## In conclusion, Dragon is an excellent meat. For health purposes it's a red meat, and by red I mean it's not soaked in its *own* blood. Seriously, long-term dietary issues should honestly be the very least of your concerns when eating dragon, as collection will always be the most detrimental part to your physique as a whole. Enjoy some dragon. (1): Citation: Have you ever seen a dragon with a six-pack? Okay, now close FurAffinity, clear your history, forget everything you've seen on that site, and tell me again. [Answer] Well in some mythologies dragon blood is a super acid, but in some mythologies eating a dragons heart can grant immortality, in Norse stories consuming dragon blood gives you magic powers. As for cooking and preparation consider directions for alligator and crocodile.They are big armored and widely eaten.They are also archosaurs like dinosaurs and birds so you can cover lots of hypothetical dragon origins at the same time. <http://www.fishfiles.com.au/handling/preparing/Pages/crocodile.aspx>. Here is a [video guide](https://www.youtube.com/watch?v=NlMg_dCB4T8) to butchering alligators. Crocodile is actually quite good, it is a bit bland but it absorbs seasoning quite well and is naturally very tender. the most meat in crocs is the tail but in a dragon I image the flight muscles would be huge. [](https://i.stack.imgur.com/Cz9z9.jpg) [Answer] ***On the Practical Aspects of Field Dressing, Preserving and Enjoyably Consuming Dragon Meat*** Pre-kill preparations. Size: even a small (broiler) dragon is the size of the largest terrestrial elephants, so you’ve got to think *scale* here -- and I don’t mean those tough, armor-like things on the outside of the beast. As General Omar Bradley is alleged to have said, “Amateurs talk about strategy, professionals talk about logistics.” So too is this true of the non-trivial task of (safely) preparing dragon meat for consumption. Consumables to have on hand, pre-kill: I suggest a minimum of one barrel of salt and two of beer per ton of dragon. (You’ll need salt and rendered dragon fat to stabilize the hide until you can ship it to tanners experienced with dragonskin.) At least as important is roughly one wagon-load of firewood per ton of dragon, about which -- and why, more later {0.-1}. Unless you’re dragon hunting in the depths of winter, you’ll want to have this with you when you start your hunt. You’ll also want every watertight barrel you can get your hands on, far beyond the salt and beer barrels. Properly cured oilcloth can stand in (for short term, at least) if you lack barrels, but you’ll need considerably more salt. Some cultures use vinegar-salt brines for preserving brine, but in field conditions I suggest beginners especially use salt or smoking to preserve the meat. Tools and such: Tripods, chain and hooks. Dragon primal cuts are *big* (even excluding the wings, which have almost no useful meat.) The Empress, in her wisdom, had a set of a dozen tripods, twelve cubits tall at the pivot point, made of the best available iron, some human generations ago. They have served her hunting parties long and well -- nor are they IMHO to numerous for handling a big dragon like Smaug. Since stainless steel is so expensive ever since that contremps with the goblins up north, <https://en.wikipedia.org/wiki/Weathering_steel> is probably the best option -- combined with a good washdown and drying in full sunlight after each use. (I successfully petitioned Her Majesty’s Minister of Coin for funds to make a number of interlocking plates of Weathering steel, to serve as a portable smokehouse. That I am writing this to you is evidence that The Imperial Tastebuds found this a worthwhile use of Imperial funds, but I digress. See {0.-1} ) Chainfalls (if your technology base can produce them) are a worthwhile investment in preventing accidents and processing those many tons of dragon speedily. This is where to spend money on your best, rust resistant steel (I favor full stainless alloy T316, myself.) Ditto the matching-pitch chain and hooks. Because the dragon (and even resulting primal cults) are so large, you’ll want cutting tools with *reach*. We find naginatas work quite well; swords (especially heavy cavalry sabers) are OK, but machetes are for hacks. Cauldrons for rendering the dragon fat and for reducing (thus stabilizing{0.0}) the dragon blood are also essential. --- Step 0 (safety): Make sure your dragon is really, really dead. They are tricky foes and happy to escape and/or avenge themselves by playing possum. Unless you’ve hacked it’s head clean off, I suggest sending a raw recruit to double check. {0.1} Step 1: (hygene and safety) Dig a deep pit as close downhill and away from open water as possible, for the disposal of the dangerous parts of the dragon {0.2}. The stomach and fire-bladder -- and all of the drained blood, unless you are stabilizing it. Put all this into the pit and keep adding water -- especially if it starts to steam again! Start at least two cookfires. (Yes, now. Don’t wait until masses of armed, dragon-blood maddened men get *hungry*!) Step 2: Only when the pit and several barrels of water are at hand, have your most experienced, brave and steady-handed butchers and/or soldiers gut the dragon and put immediately the stomach and large intestines into the pit. Follow with at least two barrels of water and watch for flare-ups for the next day. There are differing opinions on the gallbladder, gall and stones. {0.2} Step 3. Award the head and heart with suitable flourishes to those persons that Law, custom, contractual obligations or tactical prudence dictate. Step 4: Separate the wings from the carcass {0.4} Step 5: Separate primal cuts for draining. Here’s a suggested breakdown, though regional predilections/health regs. may dictate alternate cuts. * Neck (in 3+ sections to fit; best to keep head-end up until well rinsed and drained) {0.3} * Tail (in 3+ sections to fit) * Thigh/drumstick (2) (Separate the ribs from the spine and breasts, and get those cooking; your people are hungry!) * Breast (2, possibly cut into 2 sects each, if you’ve taken a large dragon) (Spine once drained, start a soup pot; see previous entry, scaled down.) Step 6: Hang to drain the blood into *iron* cauldrons. Promptly either stabilize the blood by boiling it, or dispose of into the pit with at least an equal volume of water. Step 7: Cook enough dragon meat to serve *ALL* of your friends and allies; they’ve faced a fearsome beast and won the day. Feed them well. Seriously, now is not the time to be a cheapskate. People are watching; important people. Providing BBQ sauce and beer will pay dividends in time. Note also the potential upside for trade (and taxation!) of the trade fair that often pops up to celebrate (and/or make a quick coin) on a dragon kill in populated territory (deep winter excepted unless your technology base is up to it.) I suspect that my suggestion of a default Imperial taxation at such events helped the Minister of Coin view my requests for supplementary funds {for the portable Dracon smokehouse} in a positive light; though the samples for his consideration might also have played some minor role. Step 8: Preserve as much dragon meat as you can, by smoking, salting, brining or spices (sausage.) Waste not, want not -- even at dragon *scale.* (Sorry, I couldn’t resist ;-) ~||~ {0.-1} Contrary to the fanciful notions of those writing from less than first-hand experience, I can assure you that some dragons have a wealth of body fat. There are sedentary types in all cultures. Rendered dragon fat is, as you know, a valuable source of both lubrication and long lasting calories. However, the most important type of fat on a dragon is that which is deliciously well marbled into those thin layers of muscle that we can preserve with hardwood smoke and perhaps some maple sugar: **Dracon!** And yes, it should be capitalized. Anybody who disagrees has clearly never tasted it. -- “A Dracon, lettuce and tomato sandwich, when the Dracon is nice and crispy and the tomato is ripe, even better than true love!” -- Miracle Max, just before his Witch smacked him a good one, and swiped the sandwich. {0.0} As history and legend tell us, collecting and *stabilizing* dragon blood is effectively an all or nothing proposition! Reduction to half volume and sealing in barrels seems to be the safest bet, followed by prompt shipment to somebody who will pay for it. On no account reduce any dragon blood beyond one quarter of its original volume -- even little bits. You can travel to Iceland to see the results if you’d like. Bringing your own drinking water is still advised, even after all these centuries. {0.1} Exactly *how* a raw recruit does so can yield valuable info about combat potential. The recruit who walks up and hits the dragon on the nose will be, sooner or later, arrow fodder. The recruit who nails the dragon with a crossbow quarrel in an unarmored spot, from cover and downwind is somebody who’ll last more than one campaign. {0.2} Some Mages will pay big time for these; I don’t know if it’s a drug or like Kryptonite or whatever. How brave/foolish are you and your men feeling today? On a dare, I did it once; another barrel and salt. I got paid in full, but still not eager to repeat; that color just says ‘evil’ to me. {0.3} Contrary to other reports, the neck, once properly drained, rinsed and stripped of fire-gall tubing makes a delightfully lean Dracon. Or if you have a brave sausage-maker, there’s a smoked dragon kielbasa that is to die for. If not, I’ll happily advance five gold pieces for the neck, salted down in barrels, free on my dock. I know some brave sausage makers. (Terrible english, but they are past masters of capturing and preserving umami!) {0.4} And let the tanners and scalers at the wings; there’s almost no useful meat to be had from the wings; though people from the province known as Buffalo apparently feel otherwise. A paste of two parts fine-ground salt to one part rendered dragon fat will preserve the skin for a week or two, unless the weather is really hot and humid.) [Answer] The strong muscle meat would be pleantiful but so very tough. It would have to be braised or boiled for long periods of time, or subject to chemical or mechanical tendorizing techniques. The other parts would offer many fantastic resources, though! The armored scales are tough lightweight material useful for making armor and protective clothing and many other things. The bones would be long, lightweight (hollow even) and strong. They will be used to make roofs for buildings, boats, and light vehicles. The tendons are not special safe for their size. They can make rope and lashings far more easily than using hundreds of cattle and pounding together all the small pieces. The internal organs including special unique ones will be useful: besides large bladder and stomach, what holds the flammable gas or liquid? Those organs might have special properties beyond being another bag or sausage casing. [Answer] Dragon's Tail is apparently a delicacy, if J.R.R. Tolkien is to be believed ([Farmer Giles of Ham](http://ae-lib.org.ua/texts-c/tolkien__farmer_giles_of_ham__en.htm)). It was a traditional Christmas Feast food. There is not much description of how it was cooked. Interestingly, the substitute "Mock Dragon's Tail" is sweet rather than savory, made out of cake, almond-paste, and icing. [Answer] > > why is there never any mention of how to prepare, cook and serve them > > > A dragon contains a large number of chemicals to produce fire. These chemicals leave traces in the tissue making it uneatable because it either tastes bad or is toxic. Or Fugu (Thanks @Lu22) which pumps poison into his flesh when it's scared. A dragon is some numbers larger than a cow. You cannot process it all in one peace, so you need some sort of storage. But if you'd ask how: I'd take the mother-in-law recipe for wild boar: * Fry it in a large pan on every side * Let it rest in a sauce of red wine and spices for a decent time * Simmer it until it eatable Happy cooking, Alex [Answer] Dragon meat is deeply unclean, like grizzly bear. Aside from the fact that their diet consists mostly of carrion, which causes even fresh dragon meat to reek, the fact that most adult dragons have eaten virgins and villagers raises troubling issues of meta-cannibalism. Aristocrats who cultivate a taste for dragon meat soon exude the odor of carrion, and this has come to be considered a tell-tale sign of degeneracy. The trouble of raising dragons, with their tendency to riot and murder, has confirmed all lawful and/or good religions in the condemnation of even tasting dragon meat. One cannot control a dragon; the only way to cultivate them is to dedicate a countryside to it, in which all the people are kept as a food source. Only the foul eat such murderous filth. [Answer] Inspired by Separatrix's answer... > > Dragons are heatproof, you have to serve them raw. > > > Dragon [Ceviche](https://en.wikipedia.org/wiki/Ceviche#Preparation_and_variants)! Ceviche is a dish where the fish is not cooked but instead soaked in lemon juice and the acidity of the lemons "cooks" the fish. It doesn't kill parasites in the fish but it does make it safe(er) to eat. So just throw the dragon meat into some lemon juice overnight and in the morning you will have some tasty meat to enjoy! [Answer] In consideration of the fact that nobody has answered the butchering question. Let's assume you've crossed the threshold requirement of actually *killing* one of these mofos, the butchery process will take a large team with fairly expensive equipment. Thankfully there are merchants with the capital to pay for the hunting operation and the butchering operation as the gains are very lucrative. # Requirements: As a minimum, in order to butcher a dragon well you will need either cranes and pulleys to winch it in the air to help open the soft underbelly and preserve the meat from environmental damage. As most dragons do not live in ideal environments and it's too expensive to transport such a load quickly without the quality deteriorating. A mage with strong telepathic skills can make this much easier on the team and have the dragon up in the air quickly after the kill. You will need either heatproofed weapons with an enchantment of +3 to bypass the first layer of skin and deal with the high internal heat of the body, but this can be made easier if you have a mage on the team with specialised cutting spells. Most wind mages will have these. Actually, as a general rule, a team of mages, while expensive, always saves time and manpower. Which can be crucial in keeping the quality of your product high. If you don't have mages, there is a solid industry of cutting implements, hooks and bladed staves that are made specifically for skinning dragons, gutting them, and scaling them. Don't try to get through their bones. Thanks to extraordinary amounts of magical infusion and natural density, dragon bones are about has hard as stone with a magical resistance that will tire even the most experienced of mages. While bone dust and marrow are incredibly valuable, even standalone a novice team can make a huge profit on selling just the bones as is. Clean them as you would any other bones. If you want to extract the marrow and make bone dust from them, which are worth more than their weight in gold! You will need to transport them to town in stasis chambers and have industrial bone presses and +15 Adamantite guillotines do the slicing and grinding to dust. If you're new we recommend hiring a facility in town. Nearly every part of a dragon is valuable, and the fresher it is, the more it is worth, it's recommended that you have a stasis storage and either a bag of holding or a large caravan to carry what will be metric tonnes of matter. ## Final Notes: Prime cuts have been suggested by the other individuals, however we do not recommend dressing dragon meat beyond an infusion of Mage's Bane, which helps preserve the magical qualities and strengthens the flavour. Many buyers will request undressed meat as they will want to prepare it to their preferences. Dragon ingredients are hard to come by so most buyers are specialists and very particular. You will need a small team, usually a carver, scaler, skinner, and workmen for hoists, moving goods, and organising ingredients. Though most teams are actually made up of between 20 and 50 men to speed up the process and ensure quality. Do not try to have multiple specialisations taken up by one individual. They will simply not have the time needed to ensure good quality results. Dragons are like the whales of the land. Only more valuable, and bigger. Good luck, and remember. Don't go on the field yourself. You will die. [Answer] I can imagine a giant crock pot, cooking it over a low heat for several hours, and making Pulled Dragon Sandwiches. Of course, I would be using a honey/chipotle *or even habanero* sauce to marinate the meat in, as it would only be fitting for the meat to be paired with a spicy sauce. [Answer] I think that the dragons are lizards, which I have heard taste a bit similar to chicken. The muscles would be huge, so it would probably be challenging to have a roasted dragon. Thus I think that it would make sense that the dragons are eaten as small pieces in sauce and soups. It could be that the fire breathing ability comes from some nasty fermenting process, making the dragons carcass risky to explode or meat taste bad or simply inedible. ]

[Question] [ I'm a genius inventor who's managed to come up with a drug that increases the occurrence of rational behaviour over 400% among human beings. This drug makes humans more likely to communicate effectively with others and make plans rather than rushing into situations that will be difficult to get out of and will cause many problems. I'd like to test this drug on a larger scale before final implementation, and I believe I've found the perfect test subject. One software company has been behaving rather erratically and irrationally lately, failing to properly communicate and worrying its many customers. This software company is called XYZ Industries. For this test, I'm going to need a way to administer this drug to every XYZ employee who works at their main office within a similar timeframe, ideally 24 hours. The drug can be administered via food, water, air, or injection, but it must affect every XYZ employee and no other people. How can I administer this drug to all of XYZ simultaneously, causing a sudden uptick in rationality and allowing me to move on to worldwide implementation, hopefully stopping all wars and ending much human hardship? [Answer] # Administer it during a company event Most software companies have some sort of out-of-office "townhalls" / "all hands" / outdoors training / R&R events. These vary, but typically you can find some sort of event for employees only which is either mandatory, or so enticing you can count on near 100% participation. So, step one is arrange for such an event or piggyback an already planned event. Step two is to gain access to that event as a services provider / caterer etc. (depending on chosen method of administering the drug) - as you *are* a genius, this should be attainable. Finally, step three: administering the drug - depending on the event, it can be something done **during registration** (stamp every employee's wrist or give them a silicon bracelet with a skin-contact version of the drug), something in the **food/drink/refreshments** (including the gluten-free, vegan, kosher, low lactose options, of course!) or, if applicable, as part of a **special activity** (carnival rides, VR/AR experience, massages, foam-party, swimming with dolphins etc.etc.etc. some companies do some really crazy/extravagant things, after all...) All of this is assuming: * You do not care about the ethics this experiment. * You don't need a control group receiving a placebo, you just wish to observe the effect of the drug when administered to an entire test population. * You are clever enough not to get caught. Not even by a crowd of people with artificially increased rationality. [Answer] Luckily for you someone has already developed a large scale system to deliver performance improving chemicals to all the staff employed within a premises, you just need to piggyback on it. The systems are called ***coffee vending machines*** and they are ubiquitous in all work environment. Just disguise as a maintainer, add a dispenser to the internal water tank, refill it when needed. Since it is almost a trope between all users of those machines to complain about the taste of the dispensed products, you can also get away with some taste of the drug itself. [Answer] It's too easy. There's a kitchen or lunchroom or some such. One day, a lot of trays of food show up. Little signs have a message like so. The meeting didn't happen but the catering order could not be canceled. So here is a lot of free food. Please help us dispose of it so we don't have to throw it away. Please be tidy. The free food includes pizza (both with and without animal products), sandwiches, muffins, apples, soft drinks, coffee, milk, fruit juice, and last but not least, 6 flavors of ice cream including two low-fat and one low-sugar variety. And even several dozen bottles of water. Depending on the local culture, maybe it includes some halal or kosher versions of several food products. Such things show up at my company on a regular basis. The resulting frenzy is very much like a biblical plague of locusts. If there's enough free food there's a good chance people will save some for later, or even take it home for their families. After about 10 minutes, the department support staff will be competing with each other on who can send out the cleverest email telling people about the free food. Nobody will bother trying to figure out what meeting didn't happen, because we are used to there being meetings with clients that we are not told about. The buzz phrase is "ring fence" and it means we have to keep confidential information. Maybe a software company is negotiating to do a medical database, for example, and the details have to be kept private. You could even add some special touches. Like you could make it look like the local catering company did it, the company everybody likes the food but thinks is too expensive. You could even hire them to do the catering, so they show up in uniform. [Answer] As genius inventors go, you are obviously lacking in some rationality yourself. The first recommendation is you should take a dose yourself. The proposed trial is obviously unethical and shouldn't be allowed. Not so strangely acting ethically is actually is the best method of administering the rationality boosting drug and testing its efficacy. Inform all the XYZ employees of the rationality boosting capacity of the drug. Offer bonuses for those who display marked improvement in their rational behaviour. Issue all XYZ staff with their doses of Rationality Plus TM. Naturally, half the drugs administered will be placebos and the other half the drug itself. This is standard double blind test procedure. Since you already have a measure of the erratic and irrational of XYZ main office personnel it should be possible to observe any improvement in their behaviour. Twenty-four (24) hours seems remarkably inadequate a time frame to measure any improvements in behaviour. People can easily "fake" their ability to act rationally sufficiently well over 24 hours to make it appear that the drug is working as expected. Therefore, it is recommended the trial should place over a longer timeframe. As for the widespread and largescale implementation of administering the rationality booster drug ending wars and hardship, this seems doomed to failure. The people whose decisions lead to wars and inflict hardship on populations do so for the most rational reasons. What you should apply your genius inventing to is an altruism boosting drug to be used in combination of your rationality drug. [Answer] You mentioned that it can be administered through food, water, air or injection but can it be absorbed through touch alone, entering the bloodstream through the skin? In that case you could... **Put it in the cleaning products, so that it ends up on almost every surface in the company.** If it's a software company, just about everyone is going to be fondling their keyboards, phones and various other desktop equipment throughout the day. If you can spread the drug on the keyboard with, say, a spray of liquid meant to clean or sterilise it (maybe you can fake an outbreak of flu so that all equipment needs to be "sterilised"?), then you'd be sure to affect everyone within hours. It may not even be necessary for the drug to be absorbed through the skin. Once it's on people's hand and fingers, they'll be snacking or scratching themselves or rubbing their eyes all throughout the day, and probably getting a good dose of it that way. But germ-phobic people might wash their hands too often for this to be 100% reliable. [Answer] You would have a high chance of affecting all SE employees if you mixed a vapor form of the drug into the HVAC system. [Answer] **No, you can not** You cannot reach *all* employees, because always some are on vacation, home with baby, sick, doing homeoffice etc. Even if you drug all Coffee, Food and Water, there will always be someone who brings his own water and food. Of cause you can reach *nearly* all employees as mentioned by the other answers. [Answer] Robotic mosquitoes. Assuming you can get the appropriate details on the locations of all employees who are currently working (in the office or from home) your little flying hypodermics can administer the drug. [Answer] **Mandatory drug during a specific 24 hour period. If you fail to comply, you no longer have a job with the company.** How hard was that? For justification, your insurance now requires that you test for drugs not previously tested for. Announce it a week in advance, make sure all employees get the word. You can even require confirmation of notification and signed understanding of requirements in advance to make sure you have 100% coverage. Of course, this is completely unethical - but so is the premise. [Answer] A quick and clean solution would be something like: * Mix the drug with cleaning products. * Tell the cleaning staff to clean the doorknob of the main entrances (including elevator's buttons) every hour during work-time. Everyone inside the building will touch the doorknobs or someone's else hands already infected with the drug. [Answer] I wonder how no one came up with this. I don’t know how it works on other countries, where I live (Spain), all companies are legally bound to make a health check to their employees. You can administer the drug during the tests with any excuse. With this, you make sure all the employees have taken the drug. It could be happened that some people has a private insurance and they don’t have to do the check in the health center the company chooses. Few people do. But you need to have all possibilities covered. However, if they are a considerable group, you can make their insurance company to make the health check and inject the drug there too. You have their names and you can use them as a control group. With this method you can be sure about who take the drug and who didn’t. In addition, you have their physical information and medical history. You can test if the drug works different in every person and obtain additional information. Hope this help to drug all your coworkers. [Answer] Organise a meeting within the department for some event and hug everyone or do a handshake. Since you are near the person, then it will transmit through air. [Answer] This will depend upon how much influence you have over the powers that be at SE or failing that how much access you have to the building. If you have a lot of influence, the easiest way would be a mandatory "voluntary" flu vaccine/vitamin shot or during a cross-site drug test - much like the [Guatemala syphilis experiment](https://en.wikipedia.org/wiki/Guatemala_syphilis_experiment). If you have influence with upper management and/or HR you could implement a policy that refuses paid sick leave if people do not have the flu vaccine/vitamin shot or demand drug tests done via needle-based methods. If you do not have sway over upper management or HR, but can use your inventorial skills to gain access to the building (and shut down security cameras etc), then do not fear, you can still do some testing, but it may be less somewhat less precise. * If it is an air-conditioned sealed building, then fix some air-born drug canisters into the air-conditioning units. Be careful to release the gas slowly over the day, and to remove the containers the following night * If it is not, then consider lacing all water fountains, coffee machines and other available beverages with the drug. Some people may drink more than others, but pretty much everyone will at some point take a drink during the day. If for some reason, however, you are unable to gain access to the building, do not fear there is one final method that may work. First formulate your drug into liquid form that can be absorbed through the skin, similar to LSD. Next think up an offer that all the employees could not possibly turn down (e.g. a pretzel, a free lunch, coffee, ride in a helicopter - the options are endless). Print leaflets with this offer, and if you have the budget get a matching printed t-shirt or wearable sign. Soak the leaflets in the liquid form of the drug, and stand at the entrance handing them out to employees as they enter the building (don't forget to wear gloves yourself) on a warm summer's day. Good luck with your fictional and non-suspicious mission! [Answer] If the substance you're thinking of is psilocybin, you might adminster it to everyone in an office by claiming the CEO (or VP Human Performance) baked a mushroom pie, and everyone must try it. If you think this might be too difficult to implement (some people hate mushrooms), then how about using some Lysergic Acid Diethylamide? Exquisitely potent at nanogram levels, you could probably put it into the airconditioning ducts for a 'whole-of-business' response. Manage the amounts carefully though: you want to make sure that 'microdosing' (so hot right now in Silicon Valley) doesn't cross the line into 'full-blown bad trip'. Office environments can be problematic given the 'set and setting' requirements defined by T. Leary. [Answer] Now, I do not know the specifics of the environment in which this SE operates, but depending on the type of workspace, different means of administration should be considered. Our goal is to hit every SE employee and none others - no clients, no visiting partners, no building maintenance staff (I assume they do not own their own building). For this reason, air is not an option. The chances of an accident, though they may be beneficial, should not be overlooked. Food, water, and injection remain. Water is a poor choice. If municipal tap water is contaminated, the drug will inevitably get stuck in the pipes, get sent to unintended places, and end up in the water supply. If controlled water bottles are used with dispensers, there is the risk that guests may ingest it, and there is also the chance of some members of the company simply drinking coffee or Red Cow or N hour energy instead. As a result, water is not recommended. Next is food, and injection. An injection is highly problematic as a means of administration. First, getting the entire company injected with a rogue drug will be impossible within the short timeframe - someone may be on PTO, another person may have many allergies to injections, another person may have a religious concern about injections, another may subscribe to a conspiracy surrounding injections, etc. Second, people will almost certainly try to avoid the injection when it is noted. Unless you threaten to suspend their visas/fire them/etc, they will avoid the injection. There is the concern that they may simply leave the company, but then they technically don't need to be injected to meet the requirements of infecting the entire company since they aren't part of the company anymore. So we're left with food. Choose a vegan, gluten-free option, make it free, and provide ample extras such as happy hour drinks to go along with it in order to entice as many employees to the gathering as possible. Do it on a Friday that doesn't follow a holiday. As long as you've acquired access to the delivery and are in control of the delivery person, your happy hour will result in extra productivity. Oh, but be aware of how your drug interacts with alcohol first. Best to avoid rationality-induced drunken stupor if side effects have not yet been tested. [Answer] Within the constraints of your question, you can simply round them up at gunpoint and force-feed them whatever you want. It's what software engineers call the KISS principle. ]

[Question] [ I am currently orbiting Jupiter, the rent is pretty cheap and the view is magnificent. However, my former electricity provider refuses to connect me to earth's grid for petty reasons like "are you insane?" and "how did you get there anyway?" Still, my electricity requirements are pretty high as I wish to do heavy science stuff and watch cat videos in the winter. Problem is, the sun is far away often hidden by Jupiter, there is no wind in space and mining does not seem like a good idea around here. Now, I have a lot of potential energy, as Jupiter is massive. I know that tidal power uses the moon's mass to generate energy, and Jupiter is allegedly bigger than the moon. Thanks to a lot of money, planning and duct tape, I can build pretty much anything I want. Here are now my actual questions: * Can I convert Jupiter's gravitational pull to electricity? * What is the best way to do it? * Is it a good idea with respect to other potential power sources? * How much energy can I provide? Enough for a house? A city? My actual orbit is left as a choice to you, I'd rather it to be stable and with a nice view. [Answer] There's plenty of ways to extract energy from Jupiter's gravity. The problem is how do you do so without *lowering your house's orbit*? # Tidal Flexing? (probably not worth it) When two objects interact with gravity there is a [tidal force](https://en.wikipedia.org/wiki/Tidal_force). The sides closest to each other feel a stronger tug than the sides furthest away. This causes them to stretch just a little bit. If they're rotating, this causes a cycle of stretching and compressing which extracts energy from gravity. Eventually it will slow the body's rotation until they are tidally locked. Another way to extract the tidal force is through a highly elliptical orbit. As the bodies get close to each other the tidal force increases and squeezes. As they move away the tidal force decreases and they expand. This [tidal flexing](https://en.wikipedia.org/wiki/Tidal_heating) provides a heating effect which keeps many of Jupiter's small moons much warmer than they would otherwise be. Let's say you built a huge sphere, it can be hollow because mass does not matter, and set it into a highly elliptical orbit and extracted the energy due to tidal flexing. First problem is where did you get all that material? Second is that putting it into a highly elliptical orbit will cost a lot of energy, so there's a big up-front investment. Will you make that up? I doubt you'll get a solid ROI in your lifetime, but someone is [welcome to do the math](https://en.wikipedia.org/wiki/Tidal_heating). # Use Jupiter's Magnetic Field? (unsustainable) Jupiter has an *enormous* magnetic field, and your house is moving through it. You could wrap some wire around a coil and extract electrical energy from this field! Brilliant! ...except by doing so you're creating an oppositely charged magnet which Jupiter's magnetic field draws in creating a drag on your house's orbit. You're mortgaging your house's orbit for electricity. This is a theme. You *could* kick the electro-magnet out into space. Then it will be in its own orbit. It would send the energy back to you with a laser (also a theme) and eventually crash into Jupiter. # You Can't Just "Drop" Things From Orbit When you're in orbit in a vacuum you can't just "drop" things. If you let go of something it will continue merrily along with you in orbit traveling at thousands of kilometers per hour. It has inertia keeping it going, just like your house. In order to lower a thing's orbit you have to slow it down. This has to be done either with drag or with energy. There's no atmosphere to drag against in orbit, so you need to provide energy to slow it down. You don't need to provide *all* the energy to slow it down, just enough so it scrapes the atmosphere. That will provide drag to slow it down further and eventually fall into Jupiter. # Space Trash Yo-Yo? (unsustainable) You extract energy from a gravitational field by dropping things into it. The potential energy converts to kinetic energy which can be harnessed like water falling down a waterfall and turning a turbine. But if you raised and lowered your house you'd more energy lifting yourself back out (because friction and entropy) than you gained lowering yourself. You need some disposable mass you can toss down the hole. Since you don't want to dispose of your lead figure collection, or your vintage Bricks Of The World set, you can use your trash. Not terribly sustainable, but it'll work for a while. But how do you extract energy from it? You could put the trash into a special bucket with a turbine in it, wind a wire around the turbine, attach the other end to your house, and drop it like a yo-yo. The wire unwinds as it falls, spins the turbine, and the wire transmits power back to your house. Perfect! Except it costs more energy than you'll extract. Even if you let the trash-turbine fall off the end of the wire, the wire is tugging on your house with equal energy as you're extracting and pulling it into a lower orbit. You'll need to expend more energy (not equal because, again, entropy) to keep yourself in orbit. # Space Wind Laser Turbines! (unsustainable or won't work) Instead, your trash generator... bomb will have a wind turbine attached to it. As it falls through Jupiter's atmosphere the wind generated will turn the turbine and extract energy from its fall. A laser transmits the energy back to your house. But eventually you'll run out of trash. Can we make this sustainable? Yes! Cut out the middle man. Instead of using gravitational energy to create wind power, use Jupiter's own copious wind power directly. Drop *floating* wind turbines into Jupiter's atmosphere and have it shoot the power back to you with lasers. They'll float around in Jupiter's atmosphere until they wear out. With a little engineering they can be made to steer and avoid storms. How much power can you provide? [The potential wind energy of the Earth is about 250 TW](https://engineering.stanford.edu/news/wind-could-meet-world-s-total-power-demand-and-then-some-2030). Jupiter's atmosphere is enormous in comparison and more turbulent, so it's limited by how many wind turbine dirigible parts you brought along and how long you can make them last. ...except, as [@anaximander pointed out in the comments](https://worldbuilding.stackexchange.com/users/245/anaximander), it won't work. The atmosphere is a fluid, and the turbine is floating in that fluid. It will move with the wind. This is like putting a water wheel on a boat in a river. The turbine has to be anchored to something and there's nothing to anchor it to. [Answer] # You do not Your question is akin to asking "How do I harness the potential energy of an ideal frictionless hole?". The short answer is: you do not. The longer answer is: you find something to push down the hole, converting the "object's" potential energy to kinetic energy, and then harvest that kinetic energy to drive a generator. The most obvious example of this is [hydro power dams](https://en.wikipedia.org/wiki/Hydroelectricity). A small-scale example is for instance gravity driven [pendulum clocks](https://en.wikipedia.org/wiki/Pendulum_clock). Your problem here is that you are in orbit. And any such "object" you wish to push down the hole is in orbit with you. You also do not have a nice solid anchor to which you could attach your generator. This is one of the great annoyances of being in space: it is one of the places where you have [Spherical Cow](https://en.wikipedia.org/wiki/Spherical_cow) conditions. So unlike on Earth where friction against ground and/or air is of great help to you, these do not exist in space. Once you have kinetic energy of an object in space, it is a right nuisance trying to convert it into some other form of energy (which is what happens when you generate e**x**ergy, i.e. **usable** energy). [Answer] Contrary to what previous answers said, you *can* get a lot of energy out of Jupiters enormous gravitation alone. Io already does this: it's undergoing strong tidal flexing, and this heats the interior so that moon is much more geologically active than any of the planets. So, one way to answer your demand would be: build a geothermal plant on Io. If you don't actually want to *settle on* Io, you can transfer the energy to your orbiting station via laser. This is of course not easy, but definitely more feasible than harnessing wind power in Jupiter's own atmosphere (where, even if you *could* manage to sustain the floating turbines in the upper atmosphere for long enough to be useful, it would be *crazy* difficult to point the laser steady enough in the right direction). Still, I think [electrodynamic tethers](https://worldbuilding.stackexchange.com/a/60352/9852) are a better solution, as they harness the energy directly in your own orbit. Schwern is right though that in this case, the braking effect is significant. Basically, the electrical energy you harvest comes just out of your own kinetic energy, which really is something you should not be wasteful with (crashing into Jupiter is [not a pleasant experience](https://vimeo.com/22415411)). You can still harvest *a lot* of energy before that happens – [260 kWh per kilogram you bring into orbit with you](http://www.wolframalpha.com/input/?i=1+kg+*+((jupiter+escape+velocity)%5E2+-+jupiter+gravity+*+jupiter+radius)+%2F+2+in+kWh), which corresponds to [about 37 times the energy density of coal](http://www.wolframalpha.com/input/?i=((jupiter+escape+velocity)%5E2+-+jupiter+gravity+*+jupiter+radius)+%2F+(2+*+coal+energy+density)) – but that's it then. It is possible to get more if – like with the Io geoelectric plant – you tap on the much vaster kinetic energy of one of Jupiter's moons. To do this, you need to place your orbit near one of the stable [Lagrange points](https://en.wikipedia.org/wiki/Lagrangian_point), best in Ganymede's L5 point. The electrodynamic braking will then be compensated by Ganymede's gravitational tug, some way ahead in your orbit. [Answer] ## Good News, Bad News As others have mentioned, you are not going to be able to convert gravitational energy to electric while you are still in orbit. But, thanks to all of that planning and money you mentioned you can still set up something to allow you to get the energy you need while maintaining your current lifestyle. ## Dyson Wept What we are going to do here is take the concept of a Dyson Swarm, turn it sideways, and then squint our eyes at it until it does what we want. And isn't that what Science is all about? A Dyson swarm is a series of solar panels that orbit a star, collecting energy and then transmitting it to some other location. Unlike a Dyson sphere, which is a solid shell, the swarm is made up of many small panels with spacing between them. So how does this help you around Jupiter? ## The Belt of Jupiter Instead of placing your solar energy collectors around the Sun, you can instead place them around Jupiter itself. Figure out what your orbital path will be ahead of time, and then seed the entirety of Jupiter with a ring of those solar collectors that will be near (but not intersecting!) that path. This way, no matter where Jupiter is in relation to the sun there are always some collectors aligned to absorb energy from it. Any collector your ship is in range of would transmit its power to you, and ones that were not in range would include a battery pack to store it in. As you travel along the orbit you would come into range of different collectors, triggering their batteries to start transmitting to you while the previous collectors refill their charge. ## Don't Reinvent the Wheel Of course, if you are going to go through the efforts of making something that looks like a Dyson swarm around Jupiter, you could just as easily do the same thing but around the Sun as they were originally designed. The wireless energy transmission would be harder to calibrate, but on the plus side you would gain much more energy using the same number of collectors, or conversely the same energy using far fewer. [Answer] Since the question is asking for gravitational energy, then you could consider the answers [here](https://worldbuilding.stackexchange.com/questions/53921/what-would-be-the-first-thing-humans-would-mine-on-jupiter/53944#53944) to be the "backup" plan (although given the difficulty of harnessing gravitational energy, this is actually plan "A"). Gravitational energy is not something you can directly harvest. On Earth, we generally tap into gravity by taking the potential energy from something like a mill pond or a reservoir at a high point, and convert it into kinetic energy by having the water run down a raceway to a lower point, turning a turbine or waterwheel somewhere between point "A" and point "B". The closest analogy I can think of would be to allow an electrodynamic tether to pass through Jupiter's magnetosphere. The wire will generate a current as it spirals down through the magnetosphere and energy can be beamed from the decaying orbit to a suitable receiver. This [paper](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980203952.pdf) provides calculations and gives you some idea of the magnitude of the task you are setting yourself, for example, a tether for a small spacecraft needing an average of 180W while in a 5 day orbit around Jupiter would need a tether 4.75km long by 1mm in diameter. The natural analogue is the Moon Io passes through the Jovian magnetosphere and generates an electric "arc" running between the moon and Jupiter that carries 2 *trillion* watts of electrical energy. The other takeaway from this paper is that useful power is generated inside the orbit of Europa, which is also inside the intense radiation fields of Jupiter itself, so you would either be inside a heavily armoured space habitat, or in orbit beyond Callisto and thus outside of the radiation fields. So very long tethers could be built and sent on elliptical orbits around Jupiter, beaming power back to you. As the energy is beamed from the tether, the orbit will naturally decay (you don't get something for nothing). You could beam energy back to the tether, and then it acts as the armature of an electric motor, being "pumped" against the magnetic field of Jupiter and raising the orbit. Given efficiency losses, the amount of energy being pumped back into the tether to raise its orbit will be more than you harvested as it was extracting energy from the magnetosphere, so part of your infrastructure is going to be building and launching new tethers on a periodic basis. [Answer] Not quite. But you can use it's moons, thanks to the slingshot effect. What you do is pass behind them, given their direction of orbit. The gravity of your own spacecraft will pull the moon back, slowing it down just a tiny bit, while the moon's gravity will speed you up. You basically transfer momentum from the moon to yourself. With a good aim, you can then fly through Jupiter's magnetic field at high speed and extend a tether like the one AndyD273 mentioned, converting the kinetic energy you have into useful electrical energy. This will slow you down, but if you plan it correctly, you will have enough energy to pass another moon. The downside is that you have to pass over the poles of Jupiter, and Jupiter's gravity will pull you out the orbital paths of the moons. This doesn't make it impossible, but you could spend an awful lot of time making weird orbits and not much time leeching momentum from moons or turning it into power. Solar cells, even this far out, may provide more power. [Answer] Energy can't be created or destroyed so... (for simplicity, I'm assuming your home is [Callisto](https://en.wikipedia.org/wiki/Callisto_(moon))) You total potential energy from orbit is $$\mathrm{Mass \times Gravity \times Height} \\ = 10.8×10^{22} \times \mathrm{3.86×10^{17} N \times 1,880,000km \\ = 725,842,965,000,000,000,000,000\times10^{22} Joules}$$ (Use this to calculate [gravity](http://www.ajdesigner.com/phpgravity/newtons_law_gravity_equation_force.php#ajscroll) easily) A Watt is 1 Joule/Second, so assuming you live 100 years, divide Joules by Seconds (3,153,600,000 seconds is close enough) So about $724,842,965,000,000\times10^{22}$ Watts if you crash yourself into Jupiter (but you'd die long before you reached the surface) And then for scale, a TV uses 80-400 watts. The average household uses an average of 660,000,000 watts (converted from 10,932 kilowatthours). > > roughly $100,000(\times 10^{22})$ Watts left brings you close enough to the > limit to know you'd die long before harvesting enough power from > gravity alone. (From Jupiter's atmosphere) > > > Ok, Math was off, so this may be possible if some magic device existed, but next point invalidates this plan anyways. Sadly though, you will probably be expending power to MAINTAIN your orbit. And since messing with your potential energy will decay your orbit... This really is a bad idea. The above equations assume perfect conversion. You will likely only ever harness a tiny fraction of that. You want cheap, reliable power! But the only power sources left now are the sun and what you bring from Earth... And you aren't getting nearly enough sunlight unless you build some massive solar array system. Your only 'reasonable' (everything is unreasonable at that distance) is to use a [Radioisotope thermoelectric generator](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) (output based on your model/design, though expect about 2-5 Watts/kg). (At least from a modern tech standpoint, this is what the smart people at NASA do. Just try not to make the NASA [Office of Planetary Protection](https://planetaryprotection.nasa.gov/about) upset.) [Answer] Use a **[MHD Generator](https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator)**. Problem solved. You directly tap into the magnetospheric plasma's kinetic energy by using the Lorentz force, without affecting your orbital energy OR angular momentum (the difference between both seems to elude everyone here). This one is free recharge of batteries forever. The problem with "tidal flexing" is none. First of all, there are two types of tidal internal heating on moons. One dissipates eccentricity (and thus angular momentum, not energy). That's tidal flexing. The other, weaker one, but also active in orbits with zero eccentricity (like you know, every moon in the solar system, just look at some numbers) that works through actual tidal forces, is so strongly dependent on size and mass of both objects, that your house wouldn't have a problem with it. [Answer] Direct gravitation energy is a lost cause in freefall. If you're close enough to get gravity, then you're no longer in orbit and will die soon. There is a work around though, which does use gravity, indirectly at least. By using an [Electrodynamic Tether](https://en.wikipedia.org/wiki/Electrodynamic_tether) you can tap into all the kinetic energy you have and harvest all the electricity you want. > > Electrodynamic tethers (EDTs) are long conducting wires, such as one deployed from a tether satellite, which can operate on electromagnetic principles as generators, by converting their kinetic energy to electrical energy, or as motors, converting electrical energy to kinetic energy. Electric potential is generated across a conductive tether by its motion through a planet's magnetic field. > > > And Jupiter has a massive magnetic field, which means lots and lots of energy! This isn't going to solve the bandwidth problems for streaming youtube cat videos though. **EDIT: There is no such thing as a free lunch.** Interacting with Jupiters gravity in any way will cause the house to lose momentum, and eventually deorbit. You could postpone this by passing the inertia debt off on something else, like a tidally locked ice chunk from Jupiter's rings or a moon. You could attach the ED tether to it, and use either microwaves or lasers to send the energy to your house, then when they eventually lose enough momentum to deorbit you collect the tether and place it on a new rock. **Gravity isn't the best option** Jupiter is a giant ball of mostly hydrogen, and so is for all practical purposes an unlimited supply of fuel. At the cost of having to import oxygen you could burn the hydrogen to get energy, and get drinking water as a byproduct. You could also separate out the hydrogen 3 to use in a fusion reactor for energy, and sell the resulting helium to Earth to pay the high bandwidth bills. [Answer] As others pointed out, to extract "gravitational energy" you need to let something fall down, just as in an hydroelectric dam energy is harvested by letting water fall. As the question of what to let fall arises, I suggest to use a couple of Jovian moons. The solution is quite simple, although there are a few practical problems I let to you to solve - I'm sure by the time you get to Jupiter you will have solved them. First of all you need a pair of long light and strong tethers - a few millions of kilometres should be enough. Then you need to attach an end of each tether to a different Jovian moon. Any couple of moons could work. Attach the other end of the tethers to a sheave with an spring, similar of the device used in extensible cords ([example](https://www.google.es/search?q=cable%20extensible&rlz=1C1SKPC_enES380ES382&tbm=isch&imgil=FiIY2Ix9RTfGsM%253A%253BM8m4MmZPUxi_rM%253Bhttp%25253A%25252F%25252Fwww.mbaelectronica.com%25252Ftienda%25252Fproduct_info.php%25253Fproducts_id%2525253D238&source=iu&pf=m&fir=FiIY2Ix9RTfGsM%253A%252CM8m4MmZPUxi_rM%252C_&usg=__koMkvw3YJxyCpm424Bf_jijEnUQ%3D&biw=1280&bih=709&ved=0ahUKEwjUrOHfyI3QAhVBvBQKHW6vC_MQyjcIKQ&ei=KLEbWNT4HsH4Uu7erpgP#imgrc=FiIY2Ix9RTfGsM%3A)). Keep in mind that the sheave and the spring need to be capable to allocate most of the length of the tethers, but I'm sure that if you have managed to get the tether that won't be a practical concern. Now you just need to attach an electrical generator to the sheave and you will get plenty of energy that you will be getting from the mechanical energy of a couple of Jupiter moons. Since you will be braking and accelerating them, they are likely to end falling to Jupiter or getting in the same orbit, but don't worry: there is plenty of moons around to keep powering your house. You might be concerned by the risk of the tethers getting entangled in Jupiter, but we shouldn't worry about that. If it happens - and if Jupiter surface isn't slippery enough to the tether to free itself - the planet will start pulling the moons and you will get even more energy from Jupiter's rotation. You just need to make sure that the tethers are strong enough and firmly attached to the moons. [Answer] You can get energy from tidal forces. I think the 'easiest' way would be to put a long rod on either side of your station, and have an equal mass on each rod that can slide up or down the rod. The masses are connected to a mechanism that means they both move inwards or outwards together, for example you could have a crank shaft in your station a little like the piston mechanism in an engine. You could make this 'engine' reciprocate by rotating the station, but I suspect that ends up taking energy from the rotation of your station. Instead, I think it would be best to have an elliptical orbit like Io. Attach a clock spring to your crankshaft, and keep the axis of your rods pointing towards Jupiter (tidal locking does this for free). Then as your altitude changes, so does the differential force on the two masses, so the force on the spring changes, so the crankshaft turns a little, so you can extract a bit of energy. A pitifully tiny amount of energy you say? Just use bigger masses and longer rods! This doesn't actually make you spiral in (in fact if you're outside a geostationary orbit it will make you spiral out) due to tidal acceleration. You're actually robbing energy from Jupiter's rotation. <https://physics.stackexchange.com/questions/142435/when-a-planet-is-heated-through-gravitational-pull-where-is-the-energy-taken-fr> <https://en.wikipedia.org/wiki/Tidal_acceleration> [Answer] To harness gravitational energy you have to use a slingshot to transfer momentum. Specifically transfer momentum from something orbiting the thing you're orbiting. (You can't transfer momentum from a star while orbiting that star.) Jupiter has moons right? Gravity assist and a form of aerobraking give you a method to speed up and slow down. <https://en.wikipedia.org/wiki/Gravity_assist> "Realistic portrayals of encounters in space require the consideration of three dimensions. The same principles apply, only adding the planet's velocity to that of the spacecraft requires vector addition, as shown below." Check out the diagram. <https://en.wikipedia.org/wiki/Aerobraking> "During the termination phase of the mission, a "windmill experiment" was performed: Atmospheric molecular pressure exerts a torque via the then windmill-sail-like oriented solar cell wings" Instead of converting the energy (pressure) to heat, you use a turbine and generate electricity. I would use multiple drones that travel between Io, Jupiter's upper atmosphere, and Europa. How much energy? You would calculate this by subtracting the periapsis (closest approach) speed of the Io-Jupiter orbit from the periapsis speed of the Europa-Jupiter orbit. Io takes 1.77 days to orbit and Europa takes 3.55 days so you should get a charge at least once a week. <https://en.wikipedia.org/wiki/Elliptic_orbit> velocity = sqrt( Jupiter's grav param x ( 2/dist from Jupiter - 1/length of orbit ) <https://en.wikipedia.org/wiki/Standard_gravitational_parameter> Jupiter's grav param = 1.27 x 10^17 m^3/s^-2 length of orbit = Jupiter's radius + moon's orbit radius <https://en.wikipedia.org/wiki/Jupiter> Jupiter's radius = 71,492 km <https://en.wikipedia.org/wiki/Galilean_moons> Io's orbit radius = 421,700 km Europa's orbit radius = 670,900 km Speed before aerobraking = 58,153 m/s Speed after aerobraking = 57,405 m/s Let's say your home or the drone has the mass of the Eiffel tower. <https://en.wikipedia.org/wiki/Eiffel_Tower> Ship's mass = 7,300,000 kg (The tower's original weight) kinetic energy = .5 x mass x velocity^2 The change in kinetic energy = 315,500,000,000 Kilojoule 1 joule = 0.0002777 watt hours So 87,600,000 Kilowatt hours If you could collect 20% of this you'd get 17.5 Gigawatts. That's 910 a year if you can get a charge once a week. New York uses 60,000 Gigawatts a year. <http://engineering.mit.edu/ask/how-many-wind-turbines-would-it-take-power-all-new-york-city> So you'll need 66 drones with the mass of the Eiffel tower or your home will need to be 480,000,000 kg to power a city. Europa's mass is 4.8×10^22 so go ahead and power 10 cities. If you didn't use drones this would be extremely exciting. I'm picturing a surf board shaped ship with multiple rows of paddle wheels running across the top and bottom [Answer] You can get energy from a gravitational field, but not in keeping your requirement for a stable orbit. If your orbit slowly spirals outwards your kinetic energy reduces. This could be done using Jupiter's magnetic field, turning the Jupiter/spacecraft system into a giant dynamo. However energy supply is never limitless: gradually your spacecraft will float further and further away from Jupiter, eventually leaving its gravitational influence, and entering the gravitational influence of another planet. Also, while this was happening the power generated would also drift downwards to almost zero. [Answer] I'm not a physics guy, but I know you can't simply generate energy from gravitational **FORCE** continuously. But you may get by allowing something to fall(at expense of it's potential energy), but that isn't continuous. You'll have to find some other natural method to take it back (like evaporation -> hydroelectric power from dam). ]

[Question] [ This has been puzzling me, because if the human half needs human nutrients, then suckling from the human nipples makes sense. But the horse half needs different nutrients, so which set of nipples makes most sense? [Answer] The answer is clearly the "human" nipples. Horse necks evolved so that they could reach the teats while standing up. Human necks just don't have the necessary range of motion to be able to do this.  via [Wikimedia](http://commons.wikimedia.org/wiki/File:Horse-young-nursing-0a.jpg) Did you know that horses can stand/walk around within minutes of being born? [Answer] This depends on a few things and with some considerations, **baby centaurs would probably be best suited to nurse from the human teats**, rather than the equine teats. The first thing to consider is whether the offspring is full Centaur or not. Will your story contain a race of centaurs, complete with families, culture, cities, etc.; or will the story contain a small selection of centaurs or possibly just one, as a magical/mythical being? If the centaur(s) in your story are mythical, then there is a high likelihood that any offspring of the Centaur's is half of something else too (i.e. human, horse, god, faun, minotaur, gorgon, etc.), in which case, the mythical nature of the scenario can allow you to forgo answering the question entirely via a number of interesting ways, the easiest being the spawn is born mature. If the centaurs are a race and have an obvious biological component, then the offspring is likely not a mix breed and you must indeed answer this question. **Pros and cons of the human teats:** A centaur baby will have a human head and a human mouth. **An infant mouth and a mother's teat are very much like a lock and key in most mammals.** The teat is correctly sized and adapts temporarily to each infant's nuanced differences. However, being half horse, we can consider that the infant supports itself much, much sooner than an human infant, so the mother would not be carrying around a baby for months, but rather weeks or even days. The human teat would be too far to reach easily. **Pros and cons of the equine teats:** An equine teat is far too big for a human mouth, especially an infant's. Also, an equine teat would deliver far more flow than an infant would want. But, it is conveniently positioned; the infant could reach it quickly and easily without much burden to the mother. Some have noted nutritional differences, but I think that's an odd distinction if we already assume these centaurs are a biologically natural species. If they are, then **the milk is biologically suited for centaurs regardless of which teat it comes from.** So with this in mind, **the human teat makes the most sense, but considering centaurs are neither human nor horse, there's no reason to assume that they behave or develop similarly.** What makes the most sense to me is that Infant centaurs are weaned relatively quickly from the human teat. I would say about a week. They also develop rapidly, growing the human equivalent of four or five years in only a few months. The equine teats are never used and you could even say that they do not exist. **Another, albeit creepier, option that I thought of is that infant centaurs metamorphose into their adult shape.** They could start as human infants, but then quickly or in an odd cocoon develop their horse half. Or they could do the opposite, which sounds more enticing to me because it could leave it mysterious why your centaurs have young foals nursing from their teats. Allow their culture a high integration with actual horses and no one will actually think that some foals become centaurs "spontaneously". This avoids all the problems with infants depending heavily on their mothers compared to foals. [Answer] **Clearly they suckle from a centaur's nipples. Both sets.** Centaur females have both human and horse nipples. I feel silly saying it only because it seems like such common knowledge. As with any other mammal, they might be able to suckle from another animal's nipples alone, but won't receive the complete nutrition they need. In this case suckling on either only the human nipples or only the horse nipples would not, as you point out, be complete nutrition. *Side note: Suckle is a bizarre word in that both the act of feeding the baby is suckling and the act of the baby eating is suckling. It could lead to some ambiguity.* [Answer] ## Neither - Centaur nipples would be located elsewhere. I'm making the assumption here that your centaurs are natural creatures that *just happen* to resemble both humans and horses. This doesn't apply to the traditional human-torso-replaces-horse's-neck, which has many other biological issues (as others have pointed out). Given this assumption, centaurs would have evolved so that their nipples would be easy to reach for their colts without too much inconvenience for the mother. Mares can nurse their colts while they continue to graze and slowly walk around, and the colts' necks can turn to suck on a dangling nipple. Human women can nurse their babies while walking around and supporting the baby in one hand (or a sling, to free up both), and the baby's flat faces don't get in the way. So a centaur female should likewise be able to gently move around without disrupting the child's ability to nurse.\* **Horse nipples don't work:** As cimmanon's answer shows, a centaur would have to have a neck that's far longer and more flexible than a human's in order to get under its mother to nurse. This would make the "seeming like a human" part much harder. **Human nipples don't work:** If the mother has to bend over, it's the same problem as with horses. If she picks up the child, she has to be strong enough to hold it for long periods of time, and presumably it grows similarly to a colt (and so gets heavy). **Centaurs would need outward-facing nipples relatively low to the ground.** Outward rather than downward, to support flat(human)-faced offspring. Low to the ground to support independently mobile four-legged offspring. Where would these nipples be placed? I see two possibilities, depending on how much you want to stretch the resemblance to humans and horses, although both are kindof weird. One option, which borrows more from the horse side, is to have the nipples on either side of the horse torso, probably on the lower side. By putting them on the sides, you don't require the children to contort nearly as much, while still maintaining the general behavior of horses. I don't know how much supportive tissue (breasts/udders/etc) would be necessary, but it would almost certainly be something that grew out during pregnancy and got out of the mother's way after weaning. The other option is to have more human-like nipples, but have them located approximately where a human crotch would be. This would provide the same general posture for the children as with the other option, but would require less deviation from a classic horse torso. The children would stand in front of the mother to nurse, which would make it awkward for her to move, but she would be able to reach them with her arms while they nurse (which a horse can do with her neck, but a centaur wouldn't be able to do with the side-nipple option). This has the bonus of not having sensitive parts of anatomy competing with harnesses, and (if society demands it) can be covered by a wrap similar to a human loincloth or skirt. \* Disclaimer: I have little-to-no experience with babies or colts. I may be totally off-base about nursing behavior. I'm just going based on what little I think I know combined with what makes logical sense to me. [Answer] This is complicated. Depending on choice baby centaur will either die or die. But let's dig a tad deeper. Quick search reveals that [human and lawnmower milk is rather different](http://www.nutritionmd.org/nutrition_tips/nutrition_tips_infant_nutrition/breastfeeding_milks.html) (and here is [horse](http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1757&context=ans_air)). Most notable entries are: * Vitamin C - There is none in horse milk. Humans lost ability to produce it so it must be acquired from outside (via mother in this case, but some fruits had to be sacrificed). Lack of Vit. C is very bad for humans, so by rule of thumb, even worse for baby. (Hint: do **not** google for "scurvy babies"). Theoretically horse part could supply Vit. C to human part if blood circulation would be shared. * Calcium - Horse have four times more! [Hypercalcaemia](http://en.wikipedia.org/wiki/Hypercalcaemia) sounds scary, but so does [Hypocalcaemia](http://en.wikipedia.org/wiki/Hypocalcaemia)... ARGH! Using two highly different milks would be very problematic (yeah, like anything is simple in realistic centaur design), slight imbalance in diet wold result in crippled baby (calf? calfby? balf?). Realism comes with evolution. Both two-milk and single-milk centaurs would die off without modern civilization for died supplement. So yeah, evolution... 1. Some crazy drunk god creates centaurs. I bet he was one of horny Greek ones. 2. High rate of death among infants due to dietary problems. 3. Evolution! Mares whose human milks are more similar in content have more adult babies to pass their balanced genes. 4. Evolution! Horse part can provide more milk, and is easy access for hungry balfs. Human breasts slowly became evolutionary artifact. 5. Success! Horse part provide perfect milk for balfs! So about those human breasts... I do not like idea of flat-chested centaurs, but evolution can save us again! How can useless, but surely eye-catching, human breasts be of any evolutionary advantage? Ask [Indian peafowl](http://en.wikipedia.org/wiki/Indian_peafowl), useless body part works fine for them ([which made Darwin sick](http://en.wikipedia.org/wiki/Indian_peafowl#Sexual_selection)). 1. Big human breasts = healthy, well fed, mare! Best for breeding. 2. Please wait... Breeding takes a while... 3. Human breasts role degrade from baby feeding to sexual selection. 4. Milk flow from human part stops, horse part keeps providing modified mixture. All ends well after few dozen thousands years... Better pray to [god of evolution](http://wiki.lspace.org/mediawiki/God_of_Evolution). [Answer] **Short Answer: Human Nipples** **Long Answer:** A centaur is no more 1/2 human 1/2 horse than a platypus is 1/2 duck, 1/2 otter. The centaur assuming it evolved that way would produce milk that nourishes its offspring completely. Now the question is which teat the newborns will go after. Now if we assume the horse part does what foals do it will be up and walking almost immediately. At that point the human part will be sticking up in the air and their faces will be positioned quite well for suckling at the human teat. Would you want to bend over and try to turn your head around backwards to suck the nipples on the underside of a horse? Probably not, especially if there is a convenient source of food in a much more comfortable position. [Answer] Human Breasts. Because it is very implausible for a newborn whose spine is curved in the way that a centaur's must be, and who can't possibly have more developed Motor skills than that prime example of mammalian precocialness that is a horse foal, to bend down /curl around to reach the udder. Assuming the centaur Baby is the same size in relation to the mother, as a horse foal, the Standing offspring would not quite reach the nipples at birth and either require the mother to kneel, or use a Kind of step stool. And then they would be tall enough to comfortably reach the breast after a few weeks, and would know when to wean when they grow so tall they would have to bend down... again with the spine Also, suckling from the upper Body is just cuddly and nice and allows for eye contact and hugs, so I feel that would be more appropriate for a species that has both eyes in front and participates in somewhat human-like social interactions (If that's what you're going for). [Answer] **Are centaurs [altricial](https://en.wikipedia.org/wiki/Altricial) or [precocial](https://en.wikipedia.org/wiki/Precocial)?** If they are altricial (as humans are), then they are born basically as helpless as human babies. If they are precocial, like horses, then they should develop certain abilities much more quickly than humans: in particular, they should be able to walk within a few hours after birth. **Horse-like nursing is logistically much easier, *if* the babies are capable of it**: the mother stands, the babies stand, and everything works out. But in order for this to work, centaurs would have to be precocial: a horse-like trait, rather than a human one. This is certainly doable, but the consequences can be far-reaching: **much of human culture is organized around the logistics of raising altricial young**. Precocial centaurs would not face this issue, and might organize their culture along very different lines, making them seem more alien to humans. This might be desirable for your setting, or it might not. **If centaurs are altricial, however, then human-like nursing is the only real option**. If the babies can't stand, then they can't nurse like a horse. This is not to say that carrying a centaur baby in one's arms is a particularly easy task: centaur babies would be larger and heavier than human babies, and their body shape would make the task more awkward. But this may be all that is practical, and you've got to do what you've got to do. All of the above assumes evolution by natural selection, or something very like it. **If they were created relatively recently by some artificial process, then the answer to your question probably reflects their creators**. Human-like creators would likely engineer a reproductive process as human-like as possible, including nursing, because that's what they relate to. Horse-like creators would instead probably favor a horse-like process. [Answer] There are a lot of good answers here, but they are missing something very obvious - humans have nipples because they need them to feed babies. They have two nipples, because humans very rarely have more than two babies at a time. So ask yourself: If the baby centaur suckles from the horse part, then *why does the human part have nipples*? So, I can think of two cases: 1. Centaurs evolved, therefore only have a single set of functioning nipples, and the babies suckle from those. Stick them wherever you want. 2. Centaurs were magically created, and the babies suckle from whichever nipples the wizard/god/plot that created them told them to. Given that this is worldbuilding, the answer to your question will become obvious once you answer this one: What purpose *in your world* do the nipples server? Are they a necessary plot point to the story/game/whatever? Is this something that will actually be relevant to anything, or can you just hand-wave it? [Answer] I think that both are viable. Why not make it so that it depends on the culture of the centaurs? For instance one culture of centaurs likes to upbring their babies by giving them the human teats while another culture likes to give them the horse teats. And yet another one that combines both according to the maturity of the offspring!! That would be pretty interesting, even develop it further by making certain behaviors according to what milk they received (although theoretically both milks would be the same assuming they are biological beings) [Answer] **The human nipples** I'll assume that the human breasts provide the right nutrition because I think of them as one complete organism, rather than most of a horse and much of a human. After all, if they really were part of a horse and part of a human then, depending on the genitalia involved in mating, wouldn't you either get a human baby or a colt instead of a little centaur? The human nipples are better suited for a human baby's mouth. And while it could well be that a baby centaur couldn't reach the mother's nipples while both were standing, centaurs are tool users and don't have to worry about running from wolves at a moment's notice. The mother can lay down to suckle her child. [Answer] Here is yet another argument for the human nipples: arms, horses don't have them. Horses nurse standing which present problems for centaurs because of necks. (Cows, goats, and sheep also nurse standing.) As a comparison cats dogs and pigs nurse with the mother lying on her side. Horses on their side is a sign of a sick animal. Humans and primates nurse holding their young. This solves the height and position problems and works well with latch issues. The only remaining problem is how many nipples does a centaur have? Would any be on the udder? Would there be an udder? If there was an udder I would argue for it being placed forwarward so that it could be more easily reached by the mother's hand, but I think the better solution is that if the centaur had more than two nipples that it would be best if each was on it's own breast to allow ease of reach and to prevent/minimize being front heavy given the increased demand for milk due to larger infant body mass. ]

[Question] [ **Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/55953/edit). Closed 7 years ago. [Improve this question](/posts/55953/edit) Let's say we have a character (let's call him Nelson), who can stop time and let's pretend like it's possible and comfortable for him to do it. He can see and move in stopped time, can apply force to objects and move them, hit them, whatever. Gravity still applies in stopped time. Nelson can stop time for 35 minutes (relatively to him) and three times per day and it takes a lot of mental effort for him to do. Question: how possibly another person, who doesn't have any special abilities, but enourmous budget and access to all modern tech, can stop him or kill him immediately? [Answer] Allow me to generalize all of the other answers: **No matter what his abilities, he can't prevent something if he doesn't know it's happening.** So bullets, poison, lasers, stabbing etc. all work *if they kill him before he sees them coming*. If he sees the guy about to take the shot, he can prevent it. If he doesn't, he can't. Same if he sees the laser being set up. Even a falling rock, or being hit from behind with a blackjack, works if he doesn't see it. However he can circumvent most things if he sees them in time. Now theoretically this guy might stop time every so often and just walk around to check that nobody is trying to kill him, but that would get incredibly boring and he would probably not do it very often. [Answer] # Shoot Him You just need someone to kill Nelson from behind or from a distance without being initially seen - you can't really stop time if you're already dead. A sniper bullet exceeds the speed of sound, so Nelson wouldn't be able to hear the initial shot and stop the bullet mid-flight. Or maybe that's too simple. [Answer] Stab him while he's sleeping.. [Answer] ## Drop him off a cliff You've said gravity applies, but you haven't mentioned whether his metabolism still runs, it could be that poison would work perfectly well. Does everything in his close world move with him? You could try setting him on fire. As a wise man once said: > > Give a man a fire and he's warm for a day, but set him on fire and he'll be warm for the rest of his life > > > [Answer] # Poison If time still runs for him even while stops your time, it means his bodily functions also are still functional, hence the poison will work as well. Of course it would need to be a poison without antidote, or you need to manage that he will not have an antidote in reach within the 35 minutes (assuming you know about this). [Answer] # **Fire** If objects entering Nelson's "temporal periphery," where time flows at Nelson-speed rather than 'stopped' or 'very slowly,' act upon him and are acted upon normally, theoretically you could lure him into some fairly enclosed space-- let's say a hallway-- douse the exits in fuel, and then ignite it. Stopping time oughtn't to help him here, since entering the fire will cause it to "accelerate" to his local time, burning him as normal. Because it's indoors where there is a lot of hidden geometry, he may not even know he's trapped until every exit has been burning for ten minutes or more (go ahead and sabotage the fire alarms if you like). It's possible that this method would be even *more* horrible, depending on your physics: if the gases and vapours and heat the burning fuel becomes *slow back down to regular time* as they pass away from Nelson, they'll pile up around him as a shroud of high-density, superhot gas. The gas won't do much while time is stopped, but it'll still have mass and energy that Nelson will have to push against to get through. Even if the gas only accelerates to Nelson-time in the atomic layer of material in direct contact with him, it'll still burn him as normal for that instant as the molecule combusts into its exhaust molecules, expands away, and slows back down. Not much fun on your eyes. Not much fun for the lungs. Trying to fan it away only makes it that much worse. And in thirty-five Nelson-minutes, *it explodes.* That said, it's easy to imagine that Nelson has some way to overcome this problem as he moves through regular air when time is stopped. The question is how well that technique works when the air is several hundred degrees. Even supposing Nelson chooses to remain in the hallway indefinitely and that the fumes or radiative heat don't get him and the structure doesn't collapse, it's much easier for an organization with a virtually unlimited budget to stoke a fire "forever" than it is for one man to live in a burning corridor. At that point, though, it's not exactly 'immediate.' In short, an explosion is really just speedy combustion. Materials transform into gases and expand. If a candle that burned in a night was sped up to a few seconds, there'd still be all the heat and exhaust, but it would expand away from the flame that much faster-- hours worth of heat and light and gas in a mere moment. The rest of the world might see a burning nightclub, but for as long as time is slow, Nelson is living inside an exploding hand grenade. If the housefire solution is too slow (and you did say "immediately"), you could just wait until he sits down to do something that takes more than a few minutes (sleeping, driving, reading, defecating) and fill the room up with some odourless explosive gas. Can't go anywhere at -any- speed when everywhere is either a crushing wall of burning pressure or a tearing, rupturing vacuum. In any case, the core of this method is to render the ability to stop time irrelevant by encircling Nelson with a diffuse barrier (heat is one, but you could use some caustic chemical vapour as well) that acts on him as he moves through it. It's fundamentally similar to the Trap Walls situation, and it's actually pretty easy to hide fire from someone when they're inside a burning building. Easy, and potentially a bit boring. It also feels worse to suggest. If you feel like messing with this poor guy more, you could also trap the fire extinguishers or alarms. It'd be really easy to kill someone if they are literally flipping a switch in front of you-- suppose that, instead of connecting that fire pull switch to an alarm, you connect it to a small but powerful bomb built into the wall? Maybe the extinguisher shoots napalm instead of foam? Or straight-up explodes in his hands? Maybe the overhead sprinklers spray gasoline. (*n.b.:* I really hope Nelson is the bad guy here.) [Answer] **Try to kill him four times**. If he can only stop time during the first three attempts, then when the fourth comes around, he will be no less vulnerable than anyone else. Even if he catches on and tries to conserve uses of his ability, that will also render him vulnerable. It might not be a bad idea to plan for even more attempts, in case he manages to escape one or two of them without stopping time. [Answer] ## Trap Walls If he can be trapped in a room where the walls move towards him with the intent of crushing him. He can save himself for 35 minutes, but eventually it will lead to his demise. ## Starvation Yet again if he can be trapped in a room, or chained or something similar. When he can't eat or drink for a while (assuming his metabolism doesn't pause) he'll die as well. ## EDIT: how to trap him A trap that falls away beneath him maybe as stated in the other post. Maybe make it very tempting to enter the room. Maybe provide a kind of labyrinth where he would not be able to find the actual exit in 35 minutes and is thus "micro-trapped". Then our rich avenger from the original post can start closing down tunnels one by one until the room is small enough to crush/starve him. [Answer] **Lasers!** If he is paranoid and stopping time frequently for short amounts (to look around), your best bet would be lasers. They travel with lightspeed, so you cannot see them before they hit you. Sure has to be a big laser to kill somebody, but with a huge budget that should be doable and setting up a trap where the laser isn't obvious should be doable as well. Interesting question: how can you see when you stop time and light stops traveling? [Answer] ## **Gravity fields** If gravity still applies, with your enormous budget you could set up places where the gravity is several times stronger than usual. This way, the moment, stopped time or not, where he steps in the area, he's locked up. If the field is strong enough, 35 minutes or not he won't be able to move. If you're a fun one, your gravity field could stick him to a wall, or the ceiling. If you're a classic one, stick him to the ground, and there you go. [Answer] # Nuke him Even if he sees the missile coming towards him he can stop time for only 35 minutes. That's not enough time to get out of the blast radius. It's already too late by the time he sees it. [Answer] Killing Nelson by surprise would certainly work, but for the sake of argument let's say that his body auto reacts to his eminent death and auto freezes time? Then what? There is an alternative solution, though the price you have to pay will likely render the advantage negligible. If Nelson freezes time but the future in store for him is inevitable, then Nelson is as good as dead. He can't move forward because then he dies. If he wishes to stay alive, his only option is to stay frozen in time, forever. As soon as that happens, Nelson effectively ceases to exist. Maybe he dies of old age in frozen space, maybe he gives up and chooses to face his inevitable death, or maybe he just stays in frozen space forever and is never scene after the event of his inescapable death. The moment where he's guaranteed to die acts as a sort of wall that prevents his continued existent to spread past. Now when it comes to actually orchestrating an inescapable death. There's is a huge cost to guarantee Nelson's annihilation. In theory, you could work in the shadows to orchestrate a situation where no matter Nelson's actions, he can't escape death. This however, would be very difficult. To completely prevent his escape you'd have to account for a nigh infinite amount of variables. Nelson will be afforded an infinite amount of time to escape death, so if there is even a single way to survive, he will likely find it. To truly guarantee his death you'd have to make death certain and inescapable. A very simple way of doing this, that would likely not be worth the potential reward, is to simply destroy the entire planet. If Nelson's future affords him no safe haven, he's guaranteed to be dead after his future comes to pass. As a simpler alternative, if Nelson has an escape but hasn't been able to find it: Even if he'll eventually find it given an infinite number of attempts, Nelson may just give up. If he stays young whilst in frozen space, he will still spend an enormous amount of relative time trying to survive. After spending 100s of relative years trying to find an escape to a potentially inevitable death, he may just give up trying. He may even choose to end his own life. Even if someone has an infinite amount of time to find a solution to a problem, that doesn't guarantee that the solution will be found. Edit: Alternatively, if Nelson has a fixed amount of time stopping power. 35 minutes in this example. He's liable to give up on trying to save himself from the nigh inevitable disaster much sooner. [Answer] Yawn... All of these suggestions are so boring. Why shoot him? You can shoot anybody. But someone who can stop time... Now that guy deserves an awesome ironic death, like running out of time or something. He would still age when he stops time, so let's assume he has a real age of 30 and he'll live to 80. If he can stop time for 35 minutes before recasting, and assuming recasting is instantaneous, he has around 750,000 time stops left. That's a lot of time for you to have him trapped somewhere and be gloating while he agonizes over some villainous scheme you've deployed to keep him in anguish. (Remember that mental/emotional anguish are far more hip than physical pain, especially in the long haul). And if he can't get to you and you're grinning at his suffering, remember he has to spend the next 50 years watching you smile at his misfortune. It's a 50 year victory gloat, and it'll only cost you a second or two. Don't forget to work out the logistics, though. You have to supply him with 50 years of imperishable food and water and stuff from the start. Nothing ruins a good 50 year smirk like instantaneous starvation. [Answer] # Booby Traps This is kind of derivative of DJClayworth's "Anything As Long As He Can't See It" answer, but I feel like the significant difference here is that the one who actually pulls the trigger, so to speak, is actually Nelson himself. As Clayworth points out, because the attack is a surprise, it doesn't really matter what the nature of the attack on Nelson is. In at least most of the answers here, it is presumed that Nelson is being attacked by a person (or, more accurately, suffers an attack *triggered* by another person) either directly (stabbed while sleeping; shot from afar; nuked) or indirectly (burned in a building; 'glued' to gravity plating; lured into a garbage crusher). In this case, the attack is *waiting for him somewhere-- anywhere-- in the environment*, rather than originating from a specific attacker, and to try and anticipate any possible threat from every place you're in and every single thing around you would be, at best, very, very tiresome. I mentioned previously that you could plant a small but potent explosive device in a fire alarm in a building you yourself set alight, but this could be made even easier by planting the bomb in something more mundane-- any kitchen appliance, for instance, or Nelson's car, if he drives. When the device is activated, the bomb explodes. The trap itself could be something ["quite devious"](http://simonmenner.com/_images/Boobytraps/Boobytraps27.jpg), or it could be something ["totally uninspired"](http://images.policemag.com/articles/BobbyTrap-1.jpg). Even the venerable land mine would work. Even if Nelson is so twitchy that he can slow time in response to the explosion *before it hits him* (most explosions expand beyond faster than the speed of sound, so good on him for reacting that quickly), that he can only do it thrice means that the fourth trap does him in. A drawback to this is that, while the death is relatively "instant," the resolution is not exactly "immediate:" traps are at the mercy of Nelson's whims: suppose he decides to take the bus to work instead of driving? That carbomb you spend the weekend planning out is totally wasted (until tomorrow at least). Anti-personnel mine under the back-left bedpost? Nelson fell asleep watching television instead. You even left a Whoopee Cushion on his rolly-chair at the office but the nightmaid went and threw it away. The point is that leaving it to Nelson to blunder into his own suicide requires him to do just that-- blunder into a trap-- and it seems a bit precarious to imagine someone who can stop time around himself for any or no reason, who is probably at least a little bit paranoid (given that people are asking about the best way to kill him on popular Q&A websites), getting offed by a [shotgun wired to a doorknob](https://skeptic78240.files.wordpress.com/2016/03/brannigan-09.jpg). Food for thought, though! [Answer] Here at the Temporal Continuity Association we have one core piece of knowledge: If Nielson can stop his own perceptual time, then it is possible to stop perceptual time. Our research budget is currently dedicated to discovering what that means and consequently how we can stop this travesty of temporal order. If the gentleman in question is able to interrupt time altogether, then there must be a certain amount of energy involved in the transition- it takes effort on his part and consequently that energy pathway may be detectable and/or liable to interruption. The ideal would be to prevent him transitioning back into the the regular time stream - if he likes that moment so much, he can just about stay there. A second avenue for investigation is whether he is actually moving outside of the timeline or he is just moving exceedingly fast, to the point where everything appears static to him. In this case, assuming he is somehow getting around the tricky problems of moving at relativistic velocities in terms of local spacetime. If he is moving fast, then any physical obstacles are still going to cause him problems- if those are, for example, superheated or electrified wires, or fine cutting lasers, then he will quite possibly just collide with them very fast indeed. If all else fails, we should simply contain him- he may be able to stop time, but sooner or later it should be absolutely possible to capture him in some kind of cage or cell - once sealed inside, it doesn't matter that he can stop time - unless he can also walk through walls, he's going to be stuck in there. This is the ideal situation as it enables us to study the effects he can create and how to counteract them, making it far easier to prevent this kind of ill-mannered behaviour in future. [Answer] It depends on what you mean by "time being stopped". If time itself actually becomes stationary, except for Nelson's experience, then in theory he wouldn't really be able to do much while he is stopping time, in the way of affecting physical objects - because any movement or action on a physical object is dependent on time itself in order to actually happen. Let's ignore the presence of gas particles in the air which would further complicate this in the real world - in theory all you need to do to stop Nelson from getting away is to handcuff him to yourself. Even if you propose some sort of hand-waving solution which means objects close enough to touch him move in "Nelson time", the other handcuff is still attached to yourself and you act as a kind of "anchor" - the situation can play out two ways- 1 - you are frozen in time and Nelson is unable to move you while time is frozen 2 - you are not frozen in time due to your proximity to Nelson/your connection to him via the handcuff and you are free to act accordingly On the other hand, if Nelson's ability is more an ability to "pause consciousness" en masse for people within a certain radius of his position, and only create the illusion to these people that time is stopping and starting - for one thing this is more consistent with the idea that the physical laws work exactly the same, but also it creates different issues. For one, people would notice gaps in time, when the clock suddenly moves forward ten minutes. For another, if Nelson pauses consciousness anywhere near a road, accidents are going to happen. This also affects how he can be stopped though - all you need to do is ensure he ends up in a situation where events play out that will lead to his death regardless of whether he stops time or not. For example - try to kill him on a plane. Either he doesn't stop consciousness, and dies - or he does, and the pilot crashes the plane, and he dies. [Answer] Maybe instead of stopping time Nelson's personal dimensions allows him to affect the flow of time, like you mentioned, but he can control it backward and forward for a certain period before and after the moment he activates it. Maybe he can't actually move but he can reverse time for about 20 minutes, in which his actions will be reversed but his mind will remain active and also move forward in time about 20 minutes, where he will remain still because he hasn't done anything and people would react to him being still, but he can flow forward and then back to the starting point. He could also jump back into any point in time during this interval. In essence then he could prevent death by moving back in time if he was shot suddenly and also predict the future for about 20 minutes ahead. This takes care of some of the physics concerns and makes it a little harder to kill him, while at the same time not making him super powerful. [Answer] A slightly different idea: **Frame him for something major** For example, assassinate the president and leave his fingerprints all over. It might be difficult for a single person to maintain close enough track of him to wear him out, but 35 minutes per day, divided into three segments, would not be nearly enough to escape pursuit from a well-organized intelligence bureau. It gets even harder on him if it's an international crime; get the FBI, SVR RF, and Chinese MSS on him, and there will be very few nations unwilling to turn him in. [Answer] The gravity based trap is ideal if you need him to be stopped while he's in time-stop mode. All the other answers about getting him during normal time flow or forcing him to use up his time pause ability make perfect sense - so I'll focus on the hardest option. Thin break-away floor, drop, plus spikes. Since he can apply force to objects and gravity applies, his weight will break things that aren't strong enough to support it. Also because he can apply force to objects, that means spikes can run through his body as well. If you want the non-lethal option, the trap uses weight driven mechanisms to seal him in (the pressure of him falling pushes bars/plates into place to lock him in). The difficulty, of course, is to find a way to lure him into the trap. I'd assume using several traps in the area you want to capture him in. [Answer] Using specific ways to try to kill Nelson, such as nukes or fire, is not sufficient without knowing what technology is available to Nelson. The safest option is to target him 4 or more times in 1 day with the deadliest weapons available at the time. Assuming someone with unlimited resources has access to some of those weapons. [Answer] **The Nice Way** Make him your best friend, or at least an ally. Get him into *your* ideas. Make him feel good to help, and that shift goes from antagonist to protagonist. Then, you don't have to deal with murder, and you have a Time-bending ally. That, sir, has uses. **The Way for Heartless Bastards** ..or if the nice way fails. Or even as a betrayal woven into the nice way. There is a number of methods, including (But not limited to): * Shoot him with a suppressed weapon, in the back. He won't see it, he won't hear it, but Nelson will be dead. You can even be a good distance away. * Stab him. In a crowded street, you can just sneak up on him and stab him. He can't pick out a murderer in a crowd. * Drop him out of a plane, off a cliff, etc. Anything where you can exploit the fact that he cannot pause gravity. * Ask him to pause time, pick up an object, and move it. Due to how quick he is moving (Which We can assume, since he "stops" time, the speed of light, or 299,792,458 m/s) We can do some maths. Assume he is average height for a 30 year old, with an average build. This gives him the weight of about 120 lbs (54 kg) F = M\*A, so 54kg \* 299,792,548 m/s gives us about 16.2 BILLION NEWTONS. you only need about 12,000 Newtons to break bones, so its certain he'll die. *And all he did was pick something up. Yay?* * (Lastly) Knock him out (Silently), tie him up, and cut his legs off. He won't be leaving in a hurry, or be dead, or leave a trail for you to follow. [Answer] Lock him in a bank vault or otherwise unescapeable room unexpectedly under a false pretense. Sacrifice whoever leads him into the room aswell. Let's say someone invites you into a heavily fortified room that no human can escape because the room lacks the tools to do so. Then he is in companionship of someone normally trustworthy, like his banker or someone normally in charge of that room and then locked without a hearable sound while the person is still with him. [Answer] Kill him/Stab him while he's at it... (if you know what I mean...) I don't think he'll ever stop time at that instance... On a more serious note: **There is a situation in which you can't ever kill him:** If he --- from the time he gets the power to stop time --- he stops it forever, then no one can kill him at that point. That's similar but not exact to not loosing to a super duper difficult game by pressing the pause button. [Answer] 3 chances to dodge the bullet. Simply make sure you assassinate him 4 times instead. (Add extra attempts 'just to make sure'). [Answer] **many answers here say Nelson can be killed by him not being aware of being killed** I am going to ignore that fact. There is one thing the asker states Nelson is universally affected by: ***GRAVITY*** The trick is not to kill Nelson before he can stop time. The trick is to kill him **while time is stopped**. So, it is simple really. Gravitational force comes from something or other, right? Therefore, make a weapon that generates a gravitational field naturally (i.e. Super dense metal or a machine that once kicked on generates a field regardless of whether it turns off). Then, this field just has to be able to be strong enough to trap Nelson yet not cause buildings or other structures to be disrupted. Then, just blast this "gravity trap" into space. Nelson needs to breathe. Eventually he will either freeze or suffocate to death. It doesnt matter if he stops time. He will be stuck on a mini-planetoid super-mario-galaxy style and he will eventually die. Plus, he's off the planet. So he's just gonna be gone. Whether he does or not ks now irrelevant. He is stuck. If he manages to continually prevent the missile from launching to space by breaking parts and whatnot... Just turn up the gravity trap and he won't be able to move. ]

[Question] [ The [Starmakers](https://en.wikipedia.org/wiki/Nebula) are vast. Stars are their seeds, supernovae their hatching. Unimaginable millennia pass before they even begin to blink at their neighbours, and they do not die, merely pass along their experiences to the next generation (unlike [some cosmic beings](https://worldbuilding.stackexchange.com/questions/72958/how-can-a-horror-from-beyond-reason-reliably-communicate-with-mortals)). Even the [smallest and weakest](https://en.wikipedia.org/wiki/NGC_7027) of them has thoughts that span centuries and the most raw and primal of their reflexes take decades to unfold. They talk to one another using what they might term [telepathy](https://en.wikipedia.org/wiki/Telepathy#Thought_reading), but which we would recognise as the [flickering of a near dead star](https://en.wikipedia.org/wiki/Pulsar) or a minuscule shifting in the [colours out of space](https://en.wikipedia.org/wiki/Spectral_line). In their uncountable aeons some of the Starmakers' brightest have noticed the blaring and shouting of what they call 'Short Races', beings that exist on individual planets, occasionally spreading out to a few star systems before petering out into silence. The Starmakers wish to use their vast experience to help some of these races survive further into the long night that they thought was their birthright alone. How can they initiate contact with such a fast lived race, and how can they engineer events such that a race with lifespans and social structures similar to humanity can remember them and (perhaps most importantly) respond in order to engage in some form of conversation? [Answer] # Middle management If you are driving a car, you don't go straight from first gear to seventh. You have to shift up gradually, picking up speed. Let's take an individual Starmaker, the size of a nebula. "Within" him are many, many "short-lived" star clusters. The Starmaker engineers a being whose speed of thought is slightly faster than its own - think of it as a hyper-advanced Twitter feed combined with a chatbot. Each bot-being faces a similar problem to the Starmaker itself, just one step down. It itself creates a slightly faster intermediary - perhaps one per constellation. The constellation bot makes a star-level bot. The star-level bot makes a bot that operates on a planetary, geological scale. The planet-bot creates bots that operate in the thousand-year range, those bots create decade-range-bots, and so on and so forth until you get to synthetic human being analogues. Heck, you can drill down even further, and create mayfly bots that, well, speak to mayflies, bacteria, even atoms and quarks. All of that gets fed up the chain of command, filtered for important information, and delivered in digest form to the master. Each bot can give commands to its underlings based on an understanding of its master's wishes. To a regular human, the response comes in real-time, but the Starmaker may not ever learn anything about that particular human, his civilization, or his solar system. [Answer] **Softly** In the case you mention, the differences in timescale make it pointless to try to engage in communication directly. From the sound of it, we are no more than mayflies to them. Most of us, if we talk to mayflies, are doing it because we like the sound of our own voice. However, we like to think that there's something deeper, more fundamental inside of us. It's that spark of life that drives us forward as our species mutate and evolve. That thing is believed to have been simmering for 3 billion years on our planet. That's slow enough that it's worth talking to, as we might talk to a cat, or maybe a hamster. The trick is how do you communicate with a thing deep inside of us without ripping us apart? Clearly it's a thing that we protect so if we thought solar flares were trying to tap into our primal urges we would rebel. The communication has to be soft. So soft that we hardly notice it is there, but strong enough that we can rely on it. The Starmakers would most certainly have to have exactly one thought for us. Any more than one thought would take too long to convey, so they'd want to be able to communicate everything without anything that you or I would call "changing their mind." They'd need to appear so reliable that we might not even be able to realize they're helping us directly. We might simply see it as part of the beauty of our own planet and it's delicate balance. We would reply back by either squandering what is given to us, or rejoicing in it and trying to pass it forward. But even if we choose to pass it forward, we still might not even know what it is. We might just see it as "being lucky." And that's okay. That's all the Starmakers would need, if their communication was soft enough. We wouldn't be ready to hear their full voice anyways. > > N = R\* · fᵖ · nᵉ · fˡ · fⁱ · fᶜ · L > > -Frank Drake, 1961 > > > [Answer] **Be less... hasty.** At the scale of the Starbuilders, they don't want to communicate to any one mayfly, but to the mayfly species. This means the starbuilders can still take their time, as long as they can communicate with at least one myfly species. They'd notice that even if one dies out, there's another one eventually taking their place, so there's no rush. **Grab their attention with an event at mayfly timescale that you can plan and set up.** Set up an incredibly, incredibly unlikely event: a mass supernova of 20 stars, which all took place in the same second, but separated by light-minutes. This would capture the mayflies attention, as it's impossible (or at least incredibly unlikely). This gets the mayflies attention, allowing you to use some other method to transmit data at a slow bitrate. Hopefully you can capture the imagination of multiple generations of mayflies, giving enough time to at least transmit a "hello". You could even encode data in the structure of your nebula, or in an incredibly irregular pulsar, or whatever abilities you have. Eventually one of those mayflies may come to look to see how that improbable event happened, which will allow them a chance to find your stone tablets or whatever, with your words of wisdom. **Another idea: Grab a mayfly.** Depending on your abilities, you may be able to find a large mayfly ship nearby. If you have the ability to grab it and somehow accelerate it, or move a black hole next to it, you'll be able to slow them down to your speed, enabling communication. Then, when you release them, or decelerate them, their time frame of reference will speed up again, allowing THEM to be your envoys. [Answer] Might as well post the contrarian... ## They can't. Their most raw form operates on a time scale that cannot perceive the short races, let alone intervene in a coherent method. I would liken *us* to *them* to the relationship we have with the bacteria on our eye, with an average lifespans in the 4 hour region. You can kinda perceive them (cross eyed sight?) but for the most case you are oblivious to them and their plight. An uncontrollable action to us such as a single blink might eliminate millions of them without our knowledge. You can't assist bacteria much and if you did start a process to aid these bacteria, you would be aiding ones several generations removed from the ones you first witnessed. *If you prefer... how aware of the plight of your own cells on a daily basis are you?* [Answer] Forget direct communication. Too difficult, and what purpose would it serve anyway? They want to make the short-lived species last a little longer? They don't need to communicate with them any more than a farmer needs to "talk" to his plants. All they have to do is study them enough to figure out what makes them grow, and then provide a friendly habitat... And then harvest whatever byproduct carbon-based life-forms produce that makes these giant beings even consider the tiny ones to be worthy of notice in the first place. Muahahaha! Oh, and don't forget "weed control". Seriously, they'd probably take to breeding, cultivating, and modifying chemical-based life the same way we do with bacteria. Food, medicine, warfare... Might be the "real" explanation for why interstellar wars are so common even though nobody ever really benefits from them. (An explanation that the majority of the population would not believe because they've been bred not to.) We are their food crops, their drug labs, their biological warfare agents. Think about it: Their bodies are made of stars and such. We are learning to produce deuterium, tritium, plutonium, and other, normally quite rare things that could have significant effect on such a creature's metabolism. The 50,000 years it took us to get to this point are just a good day's work to them. Now that they've got the elements they want, they just need to refine our species so we produce more of them, either by increasing the colony size, or increasing potency... I suspect this is probably "darker" than you had in mind. In that case, pick an instance where, rather than a "drug lab" the people are an "ant farm". ;) There's still no real communication, but over a few millenia of record keeping people do start to notice a large number of "highly improbable coincidences" that have somehow averted their total destruction multiple times, and come to the conclusion that there must be something looking out for them. (If they're human, they'd probably start calling it "Odin" or something.) [Answer] For some reason, this question reminds me of "Dictionary of the Khazars" <https://en.wikipedia.org/wiki/Dictionary_of_the_Khazars> . Anyway, in part of the book a sheitan and a human are guarding Sultan's golden hat. And they are bored so they start chatting, idle chit chat, about weather, women and finally, the nature of God and humanity etc. The human does not know that the other guard is sheitan. So the sheitan asks the human: Do you see that moth on the hat? How would you send a message to that moth so there is no possible way it can misunderstand it? Human guard: I do not know. Sheitan *claps hands, utterly crushing the moth*: Like this. And God communicates the same way with humans. To give a proper answer to your question, it will be very hard for the creatures to communicate with "moths" and it will have to be very, very obvious communication. Many moths might die. [Answer] Leave messages. This seems to me to be the only way to do it. If a Short Race's lifespan is the blink of an eye compared to a Starmaker's thoughts then there will be no opportunity for back-and forth communication, at least not unless the Starmakers succeed in their goal of increasing the Short Race's lifespan for long enough for that to happen. So, leave a message. Encode it in the alignment of the stars, or the cosmic microwave background, or just bury it on a convenient nearby Moon\*. Any form will do, as long as it can last long enough to still be there when the Short Race reaches scientific maturity and is ready for the knowledge it contains. Then, if all goes well, they can use its contents -- the great knowledge of the Starmakers -- to extend their civilization's life span to a duration that would permit a conversation. Some work will need to be done to make the message comprehensible. The message cannot be written in the Short Race's language, since it must be written long before the Short Race even *has* a language. But with some care a message could be constructed that contains its own key for how it should be read. (Humans have tried this with the [Arecibo message](https://en.wikipedia.org/wiki/Arecibo_message).) This might not work the first time. Perhaps the Short Race will not understand the message, or will use it to create a terrible weapon that wipes them out in the blink of an eye, etc., but that's okay. Another Short Race will arise before long; the Starmakers can use the knowledge they've gained to improve the process next time. Perhaps many iterations will be needed. Perhaps one Short Race will send a message saying "our Sun is dying now, but we've got this far, and we've discovered this technology that would have helped us escape if we'd had it sooner," and the Starmakers can pass that knowledge on to the next speicies. Or perhaps the sticking point is not technology but civilization itself - how can you create a society that will be stable for all that time, neither destroying itself through war or overshooting its resources? That might take a lot of trial and error. But once it's perfected, if it works, the result will be that the Short Race becomes a Long one and can finally meet their companions. \*ok, so that's basically the plot of 2001. [Answer] It may be possible to communicate through mathematic priciples using the flickering of stars. Which essentially is communication through light. Have a few stars nearby the short race's solar system (a couple light years or so) that flickers numbers. Example: It flickers 1 time and stops, then twice and stops, then 3 times and... well you get the point. The idea being that this star cycles the same basic numbers (up to, let say 10). This star would be to teach the numbers needed for equations. Using another star's flashing numbers have other nearby stars (which were strategically placed by the starmakers), teach addition, subtraction division and so on. Maybe one of the stars flashes once for subtraction, twice for addition and twice really quickly for equals. At the end of the cycle there would be a mathematic equation with no answer and a long pause before the cycle restarts. Once the civilization can achieve the technological advacements inorder to respond (in some way) with the equation's answer then a new cycle would appear. This new cycle would have more advanced mathematical equations and priciples using the same or different stars. An intresting aspect of this would be that however many lightyears away the stars are, would be how many years it will takes change to display. If your star is two years away and the flickering is changed, it will take the short races 2 years for them to see the flickering cycle change. Eventually this would lead to complex theories, which can have a significant impact on the survival of a intellectual species. Maybe eventually it will lead somekind of word like communication. Altough it would be challenging for these two differing beings to share a language due to major differences in environment and perspective. For example: time would be percived quite different if at all. It would probably be a rather basic language which would make it difficult to help a species survive extinction. May be a lot of leg work but im sure a solution can be achieved in this manor. Best of luck. [Answer] In attempting to communicate with the Short Races, the Starmakers are about to discover something that will revolutionise their own society as much as it will that of the short races they contact. The fact is that the short races are in fact a crucial part of the Starmakers' own lifecycle. It is no co-incidence that it was the brightest of the Starmakers who have noticed the short races, because it is the existence and development of the short races that can spur their local Starmaker into a brighter state. The key is that the short race needs to develop to a technology level that is routinely generating wormholes for their spacecraft. These wormholes allow FTL travel for the short race, but at the same time they provide a short-cut for the neural pathways of the Starmaker, allowing its thought processes, which are normally constrained by light speed, to accelerate. After a while, the Starmaker learns to harvest these wormholes; keeping them open even after the spacecraft has discarded them, thus unleashing the full potential of the Starmaker's vast intellect. This is the point at which they become capable of communicating with the short races. As more and more wormholes are created, the speed at which the Starmaker is able to think increases. At first the Starmakers do not realise what is happening. They simply believe that some of their number are smarter than the others. But when they finally take the time to observe things at this tiny scale and see what is happening, they realise that is it in their interest to not only encourage these tiny civilisations to grow, but to help them to avoid destroying themselves. Once they have understood this, they know they need to make contact. There are many ways they could do this, but the most direct way would be to use the short race's own communication equipment. The short races communications are easy to read once they begin to use radio waves and other long-distance communications. The Starmakers are able to use these to learn the languages and in time will be able to send a response capable of being picked up by the short race's hardware. It will take aeons before they achieve successful communication. Many short races will rise and fall without having any idea that there is something out there trying to talk to them. Many others will receive the communications but will fail to understand it. But eventually one race will arise that will make contact... [Answer] > > How can they initiate contact with such a fast lived race, and how can they engineer events such that a race with lifespans and social structures similar to humanity can remember them and (perhaps most importantly) respond in order to engage in some form of conversation? > > > The same way you already communicate with hyper fast entities to whom human language is unintelligible: with a compiler! What's a compiler? It's a computer program for translating thoughts expressed in human language into machine language. Bear with me here - you often instruct your computer to do things on your behalf. Compared to computers, you and I think at a positively glacial pace; let's say you [subvocalize](https://en.wikipedia.org/wiki/Subvocalization) at a rate of approximately 300 words per minute. Thus, the upper bound at which you personally can process, say, a tweet (140 characters = 28 words) would be $$\dfrac{\frac{300 \text{ words }}{\text{min}}}{\frac{28 \text{ words }}{ \text{tweet}}} \approx \dfrac{10 \text{ tweets}}{\text{min}}$$ (or 6 seconds per tweet). So you can process tweets at a rate of $\frac{1}{6}\mathit{hz}$. By comparison, a single CPU computer can run machine-level instructions at a rate of $4\mathit{ghz} = \text{4,000,000,000}\mathit{hz}$! Even if you assume it takes 100,000 instructions for a computer to process a single tweet, a single CPU is still processing tweets 250,000 times faster than you can. By analogy, an entity that processes a tweet 250,000 times slower than you would take 17.36 days to process a single tweet. So in the same way that people have been able to create compilers that transform thoughts expressed in human languages at human speeds into machine instructions operating at computer speeds without ever having gained the ability to directly work at computer speeds, these ancient and wizened creatures will need to specify their messages at their own plodding speed and then compile it down to a message that is broadcast at the much higher experiential speed of the youngling species. Because any given individual observing these messages won't live long enough to see the Old Ones compose a reply, the "Hello Universe" message the Old Ones choose needs to convey a lot of information up front. At a minimum, it needs to: * Indicate to whichever young species may be listening that it is a signal devised and sent by another intelligence. * Indicate the time scale on which a reply from the Old Ones should be anticipated. Failing to communicate how slow this conversation will be will likely lead the speedier races to assume the artifact they picked up the broadcast from was a relic of a disappeared species. You want some sort of galactic timescale hourglass here. * Make evident how the recipient can respond. If there is a physical artifact broadcasting the message, maybe it just has a switch that can be flipped by the young whippersnappers which will indicate "somebody found the thing and flipped the switch to say hi". It should be evident on the timescale of both species that the thing is calling home to report contact. [Answer] One significant problem is that with a lifeform that is so dagblasted slow, there's a limit on how much information they can transmit before we can't understand it anymore. Suppose they succeed in getting into contact with us and even learning to speak our language and communicate it to us in a way that we can receive. We ask them a question. Centuries later, when they come up with an answer, it comes in dialog from a time centuries gone, looking like [The Caturbury Tales](http://quod.lib.umich.edu/c/cme/CT/1:1.1?rgn=div2;view=fulltext): > > Whan that aprill with his shoures soote > > The droghte of march hath perced to the roote, > > > > But that's also an extremely bold supposition. If they couldn't even answer a question fast enough for the language to still be the same, how can they learn an entire language before it expires? On the other hand, us short races don't have a hope of learning their methods of communication either, since we'll only ever receive a few transmissions in all of our existence. This is impossible without help. Perhaps there is an intermediary lifeform (or several tiers of them) which can learn to communicate with both the starmakers and the short races. This is actually a rather amusing scenario, where aliens come from outer space speaking anything from Shakespeare to Old English, wanting to learn how the kids talk these days. Then in a few hundred years, they come back from outer space twerking and we all die a little inside. [Answer] > > How can they initiate contact with such a fast lived race, and how can > they engineer events such that a race with lifespans and social > structures similar to humanity can remember them and (perhaps most > importantly) respond in order to engage in some form of conversation? > > > The answer is in your own question: > > The Starmakers wish to use their vast experience to help some of these > races survive further into the long night that they thought was their > birthright alone. > > > But... > > In their uncountable aeons some of the Starmakers' brightest have > noticed the blaring and shouting of what they call 'Short Races', > beings that exist on individual planets, occasionally spreading out to > a few star systems before petering out into silence. > > > So basically what the Starmakers have to do is prevent the Short Races from petering out into silence. This should be easy enough for the Starmakers, since they are powerful enough to influence cosmic events. Not only can they cooperate to ensure cosmic events generated by them do not harm the Short Races, they can also engineer as many cosmic events as are needed to keep the Short Races alive. An example of the latter is the Starmakers engineering a cosmic event that extinguishes Earth's global warming. Once that foundation is in place, the Starmakers can start leaving a trail of messages for the Short Races — see Nathaniel's answer. The Short Races should eventually advance enough to get to the point where those messages begin to make sense to them. [Answer] There is an older scifi story (Asimov or Niven, maybe?) that touches on something like this. The immense being is normally widely dispersed and thinks on a scale relative to the distance between its parts. On a regular cycle (many, many years), this being contracts into a much more compact form, which greatly speeds up its cognitive functions to a rate that it can actually communicate at a real time rate with humans and other beings. People make pilgrimages to where this being is contracting to talk to it. I think there was some way for some to accompany it (perhaps some kind of merging) when it again expanded to its slowing thinking state. [Answer] Through minions. The same way the angelic hierarchy of the Catholic Church is structured -- God talks to the archangels, who talk to the Angels beneath them, and so on, until some minor angelic being tasked with following us whispers it in our ears. When you call Staples to ask about a copy job, you're not going to get the CEO. You're going to get the clerk, department leader, or manager of that store, who might escalate your query up the ladder. So it would work the same in reverse. So they could have star stuff minions who would whisper in our ears. [Answer] They figured out how to make stars. Why can't the just learn the peoples language and leave messages on walls? I'm sure they can make the calculations necessary to carve with lasers from a long way away. They could always just train their version of cockroaches to do it. Cockroaches can do a lot. Just move some current to the right muscles in their body and they'll do whatever you want. Don't these starmakers have faster than light travel? Edit: Now that I understand what starmakers actually are I think it would be best for them to send messages to the planets using the electromagnetic spectrum or do something using quantum entanglement, and then hope that the short races figure out that they're being spoken to. It might take a few thousand short races before the starmakers find ones that figure it out, but the starmakers have time right? ]

[Question] [ As society advances, technological discovery adds more and more to our accumulated knowledge. As such, scientists need to learn more and more to get to the point where they start exploring the boundaries of our knowledge. Sir Isaac Newton for example never had to take Calculus in college. Certainly it is easier to learn things than discover them, and things like Calculus made a bunch of *other* things easier. But it seems as though there will be ever increasing prior work in a field. And it seems that even though some advances will make things less severely complicated (or at least better abstracted), the overall trend of discovery will be for more and more complex things. Won't this eventually overtake people's lifespans? What would it take to create that scenario where becoming skilled enough in a field to advance it leaves no time to actually advance it? [Answer] It has already happened! In 322 BCE, [Aristotle](http://en.wikipedia.org/wiki/Aristotle) died. He may be considered one of the last people in the world who knew everything about everything at the time. Since then, advances have been made but very few people span more than one discipline (chemistry, physics, biology); nowadays, it is remarkable when a person spans more than a single sub discipline. But more advances are being made today than ever before, not because of great individuals who know everything but by the societal structure. Advances in computing, for example, are being incorporated into everybody's lives allowing for further advances without the people using the computers knowing everything (or even anything) about those computers. Though one thing you might want to consider is after a lot has already been discovered and some societal collapse occurs, such that people have the knowledge but not the means to test it improve upon it or discredit it. Like the people in the middle ages who must have looked at the towering Colosseum made out of concrete, and wondered how since they had lost the recipe for concrete and the architects to use it. A similar thing may happen in the future where there are books written in libraries where the people blindly follow instructions not knowing why. [Answer] While a fascinating idea, **the problem itself will never arise because of specialization**.  As soon as we know "too much" in a field, there will be new institutes on universities faculties who specialize in fundamental research. Every studying technician/engineer (for example) already has to learn "basics" like Math, Physics, Chemistry and Mechanics. If you are going to become for e.g. a higher building engineer, you will learn statics to calculate the needed dimensions for building parts like columns, etc., but you won't get into the depth of mechanics as statics is just a high level implementation of mechanics. You need to know the basics of the fundamental parts, but you don't have to know mechanics inside out to being able to calculate building statics. When you ever thought about studying some field like Physics, you will find out that you are able to study Physics on different universities (like technical university, humanistic, etc.). This is because there are already different *main topics* for such general fields - example: Astro Physics, Technical Physics, General Physics, Atom Physics, etc. And that means that there will always be people who do fundamental research, specialized research and highly specialized research where one work builds upon another. ## Edit To answer the following part of the comment: > > AstroPhysicists still need to learn Newtonian physics and electromagnetism. Wouldn't that specialization continue, causing say... Brown Dwarf AstroPhysicists to learn some fraction of general AstroPhysics and then their Brown Dwarf specialty? We learn tons about Brown Dwarves, and then need more specialities, with more foundational learning? > > > As we are the internet, we first have to fix the assumption: There won't be any specialization like "Brown Dwarf star". There might be a specialization for *stars* in general. And there might be people dedicating their research to only *dwarf stars* and maybe even only *brown dwarf stars*, but not as a research field that is run on an institute of an universities faculty like *astrophysics*. Every bigger institute has one or two leading professors, some professors who teach parts of that field and then some phd students as assistant professors. And everyone of those persons will have their research field where they do research and publish papers. Now the point is that we only need the papers. Because rule: > > You don't have to know everything. You have to know where **to find** something. > > > And this leads us to the problem that arises at the end (that we already have): > > How do we organize data in a searchable fashion that brings up everything that is *relevant to the question* ? > > > The answer to that is search engines and their internal algorithms. And systems like this network: StackExchange - which has the following general idea: > > Imagine StackExchange as a library where you don't get inside to search for books, but where you stand at the door and shout a question, then get handed a stack of books sorted by relevancy to your question - peer reviewed. > > > [Answer] I think one of the biggest things that help us is the concept of the 'black box'. We use it in programming all the time. We have something and we know what to put into it, and it gives us an answer back. We don't know what goes on inside but it has been tested by the original writers. As a programmer over the last 15 years the tools keep improving and I need to write less code to get bigger, more impressive and better programs out. Take Graphing calculators, someone has programmed them to be able to do calculus and as such you don't need a deep understanding of calc to be able to use it, just a decent general understanding of how to use the formulas correctly. That does not mean that no one needs to bother learning calc, because it is still useful and new discoveries are still happening in Math. You see examples of this all over the place, you don't need to know how GPS triangulates satellites (or even how satellites work) to be able to create an app for a phone that does something with locations and a map. There will still be people who will continue to work on the 'black boxes' but you don't need to know how they work in order to use them for new and interesting applications. Actually often once they have been abstracted out it makes it easier to do so. Some times the new ideas need to be sent back to have the black box redesigned to add or modify it. In software engineering, most software is developed using high level languages, but there are still people using assembler to do different tasks. Designing better CPU's still needs an incredible understanding of machine level languages and logic gates, though I expect they have their own set of 'higher design tools'. So in conclusion, I don't think that new discoveries will stop because we take too long learning all previous knowledge that got us there. ETA Adding a point, for how this could happen where we can't learn enough to make new discoveries. If humanity falls into decadence and gives up trying to find new discoveries. [Answer] The implication here is that each individual discoverer must start from nothing but a bag of crying cells, and build up knowledge in a linear order before making a discovery in a vacuum. In reality, I find we have an entire interwoven society trying to make the discoveries, not independent individuals. There is an entire section of society dedicated to distilling the human essence into teaching. There is an entire section devoted to building infrastructure to make it easier to step beyond. There is an entire section devoted to getting discoverers together, so that they don't ALL have to learn ALL of the knowledge; they merely need to have all of the knowledge when they put their minds together. Consider that the trade knowledge needed to run a particle accelerator is equally essential to discovery as the quantum physics models used to point the accelerator in new and exciting directions. The physicists probably don't know how to correctly shim the hundreds of segments of the accelerator to be in a perfect shape (and doesn't have the time to learn). The physics probably hasn't spent enough time with high voltage to wire up thousands of electromagnets without a short taking the entire accelerator down. This knowledge, held in the minds of the tradesmen who support the physicists, is equally essential *but the physicists never had to learn them; these skills were learned in parallel by all of humanity.* The only thing I have found which can leave us with no time to discover is society itself. If society dulls, and our lives suddenly require an entire lifetime of learning just to survive, that could be the cusp where humanity simply cannot learn any further. **However, even then there is a light at the end of the tunnel.** The poets have a *long* list of skills like "how to love" which take a lifetime to learn, and yet we keep working on them day after day. Perhaps one day, discovery will simply take the form of loving the universe and seeing what it wishes to tell us today. ## Oh fine! Lets see some math Lets try to put some mathematical equations down to make sure we're all on the same page. I'll use it to show how a rather boring society resembling the Vulcans could go about never ending discover First off, I am going to assume there is a never ending supply of things to discover in the universe. If there is a finite number of things to discover, then it is trivial to show that the number of discoveries humankind can make is finite. Let us define the universe of potential discoveries to be $\mathbb{D}$ I am going to assume the only thing in our brain that matters in the long run are structures. These are structures you have to learn over time in order to effectively do a task, such as discovering a new direction. I believe there is more to the brain, but I think this is close enough to model your question of learning and technology. Let us define these structures to be $\mathbb{S}$, the set of all helpful structures that the human brain can possibly organize into, and let $\text{Fits}(S), S\in \mathbb{S}$ to be a predicate that returns true if the set of structures $S$ would fit into a single human brain, and false otherwise. Because entering the world with new structures makes it trivial to prove we can keep discovering, we can assume $S$ of a newborn is $\emptyset$. Now we need a notation for learning. I will assume, for simplicity, that people learn at a constant rate through their entire lives. I leave it to the reader to show that handling the case where learning rate is variable is a trivial transform from this simpler case. Because I am arguing that we will never run out of things to learn, I can assume the worst case of "you can only learn one thing at a time" without loss of generality. Consider the universe of learning activities, $\mathbb{L}$. For any learning activity $l \in \mathbb{L}$, we can define a function $\text{cost}\_{\text{learn}}(l, S)$ which defines the cost (in time) of doing learning activity $l$ given that you already have all of the structures $S$ in your head. Let $\text{results}\_{\text{learn}}(l, S)$ be a function which returns a set of structures in your brain after doing a learning activity. Finally, we need a notation for discovery. $\text{cost}\_{\text{discover}}(d, S)$ is the cost of discovering a particular element of $\mathbb{D}$. Now we can define the goals. Let us define $\text{cost}\_{\text{schooling}}(L)$ and $\text{results}\_{\text{schooling}}(L)$ where $L$ is an ordered set of learning activities to be the cost and results of raising an individual up from $S = \emptyset$ through a sequence of learning activities. Thus $\text{cost}\_{\text{schooling}}$ will be the sum of $\text{cost}\_{\text{learn}}$, and $\text{results}\_{\text{schooling}}$ will be the final result at the end of iterating $\text{results}\_{\text{learn}}$. Our goal is to prove that there can always be a $\text{cost}\_{\text{schooling}}(L) + \text{cost}\_{\text{discover}}(d, \text{results}\_{\text{schooling}}(L)) < \text{lifespan}$. Let us assign this a predicate: $\text{DiscoveryCapable}(L, D\_{prev} \Leftrightarrow \exists\_{d\in\mathbb{D},L^\prime}[(\forall{l\in L^\prime} l\in L)\land d\notin D\_{prev}]$, which is a mouthful to day "A society is DiscoveryCapable if, for their set of known learning activities, and previously discovered disoveries, there exists a discoverable thing." Let us also add $\text{Discoverable}(L, d) \Leftrightarrow \exists\_{L^\prime} \text{cost}\_{\text{schooling}}(L^\prime) + \text{cost}\_{\text{discover}}(d, \text{results}\_{L^\prime}) < \text{lifespan}$, or "A discovery is discoverable if, given the known set of learning activities, someone can discover it in a lifetime." Now here we will note that $\forall\_{l\in\mathbb{L}}l \in \mathbb{D}$, or in words, every learning activity is something which can be discovered. This leads to a "Lotus Eaters" situation, where could simply continuously develop new ways to learn without going anywhere, so lets fix that. Lets define $\text{Trivial}(l)$ to be true if $\forall\_{S\in populace}\exists\_{L\_0} (\forall\_s s\in \text{results}\_{\text{learn}}(l, S) \to \text{results}\_{\text{learn}}(l, S\_0)) \land \text{cost}\_{\text{learn}}(L) \ge \text{cost}\_{\text{schooling}}(L\_0) $. In other words, its trivial to develop a new learning activity which doesn't teach anything new and costs more than an existing schooling! Now we do a proof by contradiction. We assume $\text{DiscoveryCapable}(L, D\_{prev})$ is false for our society. We will prove this is contradictory, meaning there is no such society that cannot find a discovery. If $\text{DiscoveryCapable}$ is false, then that means there are no new non-trivial learning activities which are discoverable. If we find that there must be a non-trivial learning activity to discover, we have a proof by contradiction. This means we must prove $\forall\_{L, D\_{prev}}\exists\_l \lnot \text{Trivial}(l) \land \text{Discoverable}(L, l)$ Consider the Turing machine, which is accepted to be far simpler than even a human. If we can prove that, at this time, a Turing machine can develop a new useful learning activity for us, then we can make a discovery simply by following that program. We are, after all, at least as impressive as computers. Let us devise a turing machine to help. Select a subset of $L$ called $L\_T$ which is the learning activities which can be analyzed by a Turing machine. We want to find a program which finds a $l \notin L\_T$ such that $\lnot \text{Trivial}(l)$. The first step is easy. It is trivial for computers to find an activity $\exists\_{l\in 2^{L\_T}} l \notin L$. Such power set behaviors occur all the time in NP problems. Now what if the computer can't do this? The next step is to gather some data about the universe. If we can't find any new data, then we are literally out of things to discover. If we find new data, we can have the computers crunch it harder, to find things that we don't understand, but computers can find. If they cannot, then all Turing-capable learning methods are exhausted, and we have covered the universe with our computational prowess. We, in effect, used computers to extend our life, crunching a subset of our possible learning activities, in hopes of finding a new one. And now we sit back and look at the non Turing learning activities. It is not easy to tell if there is a faster way to learn such things. In fact, the only limit seems to be creativity. *The only limit for our capacity to discover is our own creativity.* [Answer] Sometimes the most significant contributions to science are ways to [simplify or visualize](https://en.wikipedia.org/wiki/Feynman_diagram) things to make a complex topic easier to learn and understand. Other times the contribution is a way to [organize knowledge](https://en.wikipedia.org/wiki/Linnaean_taxonomy) again making the body of scientific knowledge easier to learn and understand. So far in human history ways have been invented to help learning so that the best and brightest are able to contribute new discoveries after learning the base knowledge of their field of research. I see no reason this trend can not continue. [Answer] ## The premise is flawed. Your premise assumes knowledge is constantly increasing. Actually, evolutionary scientists assure us that mankind 5000 years ago had precisely the same intellectual capacity as mankind today. **The total amount of knowledge that any one person has doesn't change at all**. You know nothing that is more important than what a man of 5000 years ago knew - in a pure or abstract sense. You know things that pertain to survival in your world, he knew things that pertained to survival in his world. Your example was Calculus. Calculus is not useful in almost any world, its useful only these days to people who program calculus engines in computers, since anyone who needs applied Calculus would use a computer, and doesn't need to actually understand anything about Calculus. And a fellow throwing a spear 5000 years ago didn't need Calculus to predict its trajectory. As an example, I just did a complex image processing problem involving which required, at the computational level, some really advanced matrix algebra, but I know nothing about such things and don't need to know them. I used a "perspective transformation" that someone else had written. I understand at a rudimentary level what it means to transform a perspective in a picture, and then I used the routine someone had written. The only person on earth who needs to know matrix algebra is the guy writing these tools. I just used it, at the cutting edge of vision processing, at the cutting edge of human achievement, while knowing nothing about that ancient and pointless science or math underlying it. My knowledge is exactly the same as the guy 5000 year ago. He knew all about hunting, how to get downwind of his quarry, how to find his quarry, how to kill it. His knowledge of such things was advanced. Its kind of arrogant and feckless to imagine people today know *more* than people in the past. Its a very common kind of cultural arrogance, to imagine one's tiny bit of information is the *best* bits of information that exist. Its the **proximity fallacy**, because you know those things, you imagine they are the only things that are true. **Have ore respect for your ancestors. They knew a lot more about all kinds of things than you know. Such as philosophy, religion, the meaning of life. They were far more advanced in these areas.** [Answer] # Specialization as the 'solution' So, most answers are bringing up specialization as the 'solution' to the 'problem', however this is ignoring that despite specialization there is a limit. After all, right now it takes about 20 to 30 years to get specialized in a cutting edge specific field where actual research is done. If that would be the average age of humans than we would thus have reached the point already. Luckily we get about 4 times as old (though not all of that is actually 'useful' time), so there is still a lot of room for even more specialization and our primary and secondary school systems are hardly specialized as well, so there is still room for improvement there as well. Now, we can go out on a limp and imagine things like AI's taking over the work for us or increasing our longevity, but that presupposes that such developments could be made before we hit the boundary under investigation. Whether or not that's likely is hard to determine, but from a world building perspective both things are quite possible and arguing one way or the other is quite pointless. # So, can we build a world that hit such a boundary? If we would like to argue that this boundary was reached and estimate at which point this would be the argument would look something like the following: 1. 'Knowledge' is growing quickly, making any estimate is hard, but if I take my own fields an estimate that knowledge is doubled over a time period of the last 30 years would seem quite conservative. 2. Right now it takes 20 years conservatively to get to the cutting edge of a certain field * Note: I am counting child years as well, why? Because that's efficient learning just as much as later stages in life are 3. At this rate it would mean that in another 30 years without any increases in efficiency it would take 40 years to get to the cutting edge and in 60 years it would take 80 years. 4. Education will improve in efficiencly **a lot** the closer we reach this boundary, so for a conservative estimate 150 years would sound quite reasonable * (Of course still assuming no gigantic breakthrough is made which removes this issue entirely, but within the context of worldbuilding.SE that's quite possible). [Answer] I believe this will never happen. After all, that's why we have specialists. For example, I study approximatly 5 years IT, then call myself an expert in IT (compared to the average citizen). I have no idea about Physics (except what I need), Biology etc. Ask a Microbiologist about ... something not being Microbiology. He will most likely only be able to give you a vague answer. It will still be better than what I ever could give you, but you would be better off asking the right specialist. If I would get a dollar for each time someone comes to me and asks *"You study IT, right?"*... So no, I don't think we will reach a point where we can't advance because we know too much. --- **But**, we might reach a point where an advancment in one area doesn't reach another area, simply because they became to distant. Each area of Science speaks its own language. When I talk with IT-Students from other universities, I often have to clear some words which are in itself Synonyms, but one is common at one place and one at the other. Now imagine a wide field as Physics. Two fields of research could differ so much that both use the same words with different meanings, and different words with the same meaning. It would be impossible for a researcher `A` to find material from area `B`, simply because `A` doesn't know the right key-words. Luckily we have computers today. Did you ever google something, and got results which did not contain any of the words you searched, but were still on-topic? Computers are fast in comparing huge amounts of data. Google for example rates content depending on it's importance (how many people use this specific ressource?) and its relevance (how many of the search words *or its synonyms* fit this result?). [Answer] Going to use the concept of Holon's by Kevin Wilbur for this one...the fact is all knowledge is somewhere based on assumption and no one by definition can know all. Every idea is a 'holon'. It is in and of itself a whole (one whole idea). However if you zoom in on this holon, you will discover it is not a single whole, but a whole made up of other parts. Each of these parts is a holon in and of itself. So all ideas are holons and are composed of holons. Now if you 'zoom out' you will discover this holon is indeed part of other holons as well. Kinda a crash course on the Holon concept. All knowledge is based on one of two methods...dissecting existing holons to discover new ones or combining holons to make new ones. What this ultimately means is all knowledge (always) is somewhere based on assumption (whether we convince ourselves this assumption is well established by the scientific method or otherwise) where we are using a holon without understanding the elements that fully make it up. You don't need to understand every level of a holon to create a new one (otherwise knowledge by definition is impossible). A self driving car can be created by someone not knowing the basics of internal combustion, they just need the concept of the car. Combustion engines can be created by those that do not understand the chemistry behind combustion, they just need the concept of combustion. One who understands the chemistry behind combustion doesn't need to understand the mechanic of a combustion engine, nor the electronics behind a self driving car, nor the physics of the atoms structure involved in chemistry. Do you need to understand the inner workings of the monitor in front of you to be able to use it to create new ideas? So my answer is no...the very foundation of knowledge is ultimately assumption, as the human race advances, the starting point of assumption for each human changes. One can argue that a holon can exist that know one person could ever fully conceive, but our social nature allows us to adopt another's holons (and assumptions) as required. [Answer] There are several answers here that seem to deal with specialization and to some other extent the idea that most discoveries are teams of scientists now-a-days. However I would like to point out the fact that as knowledge increases (where you have to "learn more" to be at the top of your field) so too does the general quality of life for humanity. As we develop better medical techniques and practices life expectancy will continue to improve. Some of the more science fiction themes on this topic involve ideas like clinical immortality or the ability to transfer our biological consciousness to a machine; these are a ways off in terms of what science may be capable of currently but in the future may be common place. For a quick example of this concept look at the setting in which the TV show Futurama takes place: The Professor is over 159 years old (at the beginning of the show) and spent a great deal of time learning about science, however he's still alive and inventing things even at that age. We also see the technology to keep heads alive in jars which can limit the ability to work on some things (although we do see the capability for the heads to interface with robot bodies) and several episodes show the heads of musicians still performing and writing new works. [Answer] I'll try to take a different tack, since your comments suggest no one's really gone where you'd like yet. There's similar concern which basically can be summed as, "given the rate machines are overtaking work humans have traditionally done better, what will we do when there aren't enough necessary jobs left to keep us busy?" It's a little surprising to me that these parallel as well as they do, since I suspect the question I pose may become a reality in our lifetime, while I found myself agreeing with most of the respondents to your question that there's still so much we don't know about ourselves and this planet and the universe that we'll have much left to learn. To illustrate this parallel, I'll reduce both statements to: Given that our drive to improve is one of our more endearing traits, how would humans cope with a situation in which there isn't really anything meaningful left to accomplish? Amusingly, I think generalizing both of our concerns into this form reveals the only aspirational escape from both: If our species survives until the educational investment required to advance our traditional fields is longer than the time it would take to fly to the nearest unexplored star/planet, manifest destiny will once again carry the most curious of us off into the darkness on its wings. [Answer] In Science Fiction, civilisations where nothing new is created can be found - for example, Asimov's Trantor civilisation. However, in that case it still seems that the problem is not that it takes too long to learn everything before you can start something new, but that doing your own, new thing instead of just regurgitating many hundred year old texts by the great masters of the past is frowned upon. If we reached the point, I think there might be a huge phase of "cleaning up" to do, where all the knowledge that we have collected and that someone might want to learn is re-examined, checked for correctness, and put into the form that is easiest and quickest to learn. At the moment, scientists don't have the time to put their works into an easily accessible form as they need to publish; so if it takes too long to go through the whole works that need to be known to find something new, there's plenty of work to do to reduce the time of learning. [Answer] Forgetting something is also a part of solution. Example: One of the almost-forgotten, recently revived arts is [Polynesian navigation](http://en.wikipedia.org/wiki/Polynesian_navigation), without charts or navigation equipment. It is nice that it was saved and someone is trained in it, but if forgotten, it would have no effects on our capability to navigate. So forgetting less effective way to goal, if we have more effective way, buys you some wiggle room. Possibly, in the future we develop more advanced/specialized ways to accomplish same design goals. Like integrating some measurement instruments directly into our senses, so you can learn selected areas faster. Of course this would push specialization even deeper. Better mental models of some laws may also improve speed of learning. This improvements, however marginal, will push the break-even moment further - eventually we may integrate cyber chips to brain and became cyborgs. Sci-fi area. Singularity ensues. [Answer] Interesting question, but not really askable. Knowledge is an efficiency modifier or force multiplier for discovery, not a necessary element. It will certainly help recognize discovery, but the discovery process is often counterintuitive to those steeped in knowledge. And the assumption that people in a society will absorb the knowledge on which it is based... Not really viable. If it were, would we have Creationists? [Answer] There is also the possibility of a more pure knowledge to be gained about the stuff we thought we knew pretty well. As we go, subjects may become easier to understand. Just like how Algebra used to be incredibly hard and mostly in the dark, and only the most brilliant worked on it, but now that we know more we are teaching our middle schoolers it. This stuff is theoretical, and I like to refer to it as the Compaction of Knowledge. It's kind-of like describing a game by starting out with its source code (and you don‘t know how to read it). Maybe we will be able to describe the entire universe in a set of words some day, when we understand why things are the way they are. [Answer] We should think of this problem in terms of trees. For simplicity's sake, let us assume that knowledge forms a directed acyclic graph from the most basic to the most complicated facts. Further, let us consider that "learning" is a means of gradually covering this graph, starting from the root. A "discovery" occurs when someone reaches a boundary of the graph, and extends it with a new node. Part of what makes discovery difficult is that it often requires covering large parts of the graph to correctly extend it, and we often don't know which parts to study in order to make an advance (not to mention that luck/serendipity surely plays a role). Even so, the essential feature of this tree-like graph, with respect to the posed question, is: how quickly does it branch? We can roughly consider the depth of the tree at any given node to be a rough measure of how much study is required to comprehend that node. If the tree branches only narrowly, then the depth of knowledge required to add a new layer grows quickly, and we should anticipate the limits of human discovery. If, on the other hand, it branches widely, then the increase in learning required will grow much more slowly than the number of discoverable facts available at a given knowledge level. Since tree depth (or height, if you prefer) only grows logarithmically with the total size of the tree (for regular/full trees), we have some comfort that the universe of discoverable facts grows much more quickly than the need to study to reach those facts. On the other hand, it implies that we have an exponentially rising number of discoverable facts to learn. ;) As some people pointed out, the tree isn't exactly "clean" or "neat". At some point, the bigger danger will likely be folks rediscovering things because the similarity or equivalence of some concepts will not be readily apparent, or because the knowledge required to understand them will not be available to the independent discoverers. [Answer] It is called singularity. There is theory (I forgot name or link) of increasing rate of progress. Before and during stone age, adding one step to technology took 10K years. After few steps, we got to next level, and rate of progress increased by two magnitudes about 12K years ago, to a century or so. After about a dozen steps, say 1300CE, rate of progress increased again, to under a century. Few steps, industrial revolution, next level, rate of progress increased by another order of magnitude: step is about one generation. At it was about one generation since, because it takes 20+ years to start learning new stuff. Most recently, as you correctly noticed, rate of progress is so steep that often is impossible to even read all relevant literature in your area, and some research is duplicated because of that. In few decades, **when artificial intelligence will become capable to design/improve AI,** rate of progress will increase again. **AI does not need to spend 10 years to get born, potty trained, learn to talk and become literate.** And humans will become incapable of compete, or catch up. AI will be able to do research faster than we can read or comprehend it. Interesting times ahead. But we do have few decades to prepare for that. Only protection is not to let this happen, I do hope that we will protect somehow ourselves from such AI. But AI might be smart enough not to let us know what it can do. And having smart AI out-innovate our enemies might seem to be a military advantage, for a while. [Answer] There are many excellent answers for why this probably wouldn't happen.. for an incredible amount of time. One thing I'd like to add to that discussion is that our life expectancy will continue to grow with more knowledge of the medical field. It could be eventually that we can spend 200 years learning a topic, but we don't die until we are 1000 years old. But perhaps, in the extremely far future.. after there is nothing left to discover about our physical universe after all physical items are perfectly designed.. It could be that the only thing left to "discover" is who we are and to experience the things that we, as individuals, haven't yet experienced. The only things left to create are what is considered to be art today, things that create new unique experiences. [Answer] Something being missed here is that this can happen to a specific field. No one will ever know everything. But there can be fields where no further progress is possible because it takes a lifetime to develop an understanding to the point where you can actually add to the corpus of information. I remember reading particle physics is about there. [Answer] Sure, I can come up with 4 arguments for how this would happen: Premise 1: It takes a finite amount of time to read something. Premise 2: It takes a finite amount of time to write something. Argument 1: You need to learn a set amount of prerequisites before you can discover new things. As the amount of prerequisites grows, eventually merely reading the prerequisites will take longer than the human lifespan. Argument 2: You need time to write down your ideas and discoveries. As words are continuously being written, the range of the English alphabet is continuously used up, eventually merely writing something that hasn't been written before will take longer than the human lifespan. Argument 3: You need new equipment to make new scientific discoveries. As the space of possible equipments are continuously exhausted, eventually it will take longer than the human lifespan just to invent a new equipment. Argument 4: Ideas can be represented as a sequence of bits. As the space of ideas is continuously being used up, eventually it will take more bits than the number of atoms in the universe to represent a new idea. ]

[Question] [ Imagine a world like ours, with humans that have a soul which passes on into a new human body, taking the memories with it. They get accessible during puberty, gradually. as the number of humans is increasing, if no old soul is available, a new one is created. We all know, knowledge is power. Older souls have more knowledge. But wait, knowing who the king of Takatakaland was in 356 yields no benefit, it's commonly available knowledge. There are no undiscovered ancient ruins to poach, because many know about them. Being able to use a bow is nice and all, but guns are stronger. The question is, **what kind of knowledge does actually translate to power?** Most things I learn during my life will be useless in a century. Having some more experience sounds nice and all, but knowledge doesn't necessarily make you wiser ... I'm specifically looking for *timeless* skills. Is it reasonable to say that charisma and rhetorical skills would be among the "best"? Or is there a skill that could have been developed ages ago, perfected during the centuries and would now be of amazing usefulness? [Answer] Knowledge is also *experience*. So the art of war, running a business, politics, law, medicine, many artistic skills, acting, etc. Even if a specific tidbit of historical data isn't really relevant, the accumulated experience of lifetimes, combined with a young body, can be a powerful combination. Folks will probably start to specialize to a high degree, compounding their lifetimes. Some problems though. What about language? Are different cultures being mixed in or do you only get reincarnated into your own tribe? If your lifetime memory jumps from Japan to the Sahara, to Mesoamerica, to Victorian England then not only are you going to have a polyglot of languages, but almost anything culturally connected is going to have a disconnect. Of course if this soul sharing goes on for more than a few generations then most of the world would probably homogenize as sharing technology, language, and advantageous customs would happen extremely quickly across great distances, with the bonus of having an **expert** tech to teach others, not just hearing about it or reverse engineering an example. There will also have to be a mechanism to transfer wealth, since rich folks are gonna want to have access to their stuff in their next life. Secret societies based on hidden knowledge, used to authenticate past life identities, would probably be common since there is no other way to ensure your stuff goes just to you. Buried treasure will also become a thing as folks hide stuff and hope to one day get back to it in a new body. I suspect there will be some attempt to stabilize society/technology so the older folks have an advantage over "virgin" souls. New souls will be more eager to develop something new so they can gain an advantage in their next life, otherwise they are competing with people with *centuries* of experience. So you will not have open universities and free sharing of information, instead it will more resemble the guild societies of earlier periods where admission is difficult and everything is verbally passed on. This way the old souls can keep the new souls in check, regulate the development of civilization, and ensure LONG TERM plans, since these souls will still be around to reap what they have sown. Heck, they will probably interrogate everyone as they hit puberty to determine what "soul caste" they belong to, so once a servant always a servant, etc. So hidden knowledge would be the key to moving between castes, lower caste souls would always be trying to learn enough to get "promoted" in their next incarnation. To address shufflepants, there are other significant considerations. What kind of medical care would you develop if death was not the end? Would you even try to save a critically injured person and commit all those resources? Would people want a long and painful recovery with permanent injury if they could just suicide? I suspect that most folks would persist, since death means it will be decades before "you" return, and if it is just memories in a new body that spent 12+ years of life as a new person, would "you" still be you? What if you gender swap? Get born into an ethnicity that you spent the last lifetime fighting against or suffering under? Clearly these memories probably don't carry the entire personality with them, *Cloud Atlas* aside, your soul may remember loving someone but won't necessarily still love them (even if there is now just a 13 year age difference). So memories stripped of emotional attachment will affect society differently than actual personality transference. So society will definitely be very different. I almost wonder if people will just cluster in one area of the planet so your past memories will retain as much viability to your new life as possible. Since memories persist I think there would be a much lower birth rate once a modern medical system is established as environmental change would be a lot more noticeable, so human impact on the ecosystem would have to be very minimal. War would be just an ephemeral exercise in futility, since no one is actually dying and resources gained/disputes settled would redistribute again in a generation or two. Although a *massive* war (or famine/plague, etc) could "fill the queue" for soul reincarnation for decades, which would delay new souls from being born. Prolonged peacetime, conversely, may lead to population booms and a fresh injection of new souls, suckers that could be sent to do the hard jobs the old souls no longer what to do. Some very interesting human genetic manipulation could also be possible. Only the tall and strong may be allowed to mate, for example, since there would be no pressing need to procreate since you could just wait for a more favorable reincarnation (and would have memories to appreciate the change in the population). Can a soul be destroyed? Captured? Ascend into a heaven? No one may ever know but I suspect religions would spring up around these ideas and lead to ideological clashes. [Answer] I'm thinking the old souls get a huge advantage, mostly within the soft sciences. Think about how many people make tons of money and wield great influence simply because they have a knack for reading people and can predict, with a decent amount of accuracy, what people will do. The Stock Market runs on this knack. A company is doing something and the sharp analyst predicts how people will react to that particular event. Example: Samsung announces the most amazing technology, say they have cracked the secret to Smell-o-vision and are looking to incorporate it into the Gear-VR. The Old soul analyst is going to hear about this and because of long experience with people and patterns, will be able to predict with a greater degree of accuracy than most. whether or not the Smellovision Gear VR will be a big thing or a bust. He will then invest or not accordingly. In Politics, the Old Soul is going to be able to say "Hey guys, We tried this in Rome and the next thing we knew we got an Emperor and well, we had to stab him...but by then the damage was done". Imagine the kind of clout a Re-incarnated Cicero would have had on the US Founding Fathers. Books and other kinds of records are fantastic for getting information down and learnable, but how many times have you read something from long ago and find yourself wishing for the opportunity to ask questions? With serial reincarnation, you not only get to ask them, but the answers will have the benefit of everything experienced since. Engineering and technology will get a boost, but as a pass along effect. The Pass along will come from the more pure, observational sciences. Advances will come there because the deep, profound, understanding will be retained. The Reincarnation of someone like Einstein is going to be able to *really* understand relativity at a pretty young age without having to go through 8 years of school just to get his math up to scratch enough to follow it. Quantum theory is the same sort of thing. The old souls get to skip 30 years of learning what their predecessors figured out and move right along to creating new stuff and breaking new ground. Those advances are going to drive technology pretty fast, but it won't be direct benefit You can have a lot of fun trying to figure out how to do serial inheritance and the nuances surrounding intellectual property. Neat stuff in this premise. [Answer] **The knowledge of your errors, mistakes and screw-ups** People are talking about experience, but a person's successes can be blinding. Revering someone could make that person aloof and careless. Some people do not want to see that they are in danger until it is too late. Etienne said it quite eloquently: *"Si jeunesse savait, si vieillesse pouvait, rien ne se perdrait."* (If the young would know and the old would be able to, nothing would be lost). It is the knowledge of their **errors** which would make a human with several reincarnations so formidable. It would prevent someone from losing precious lifetime pursuing something (s)he will never be able to be good at. It would prevent you from doing something because other people are urging you in a direction and you are neglecting yourself. It prevents false friends. It prevents you from having too rosy a picture of the people surrounding you and it prevents despair because you know that there are people out there who care. And simple knowledge by telling people often does not have the required effect; unfortunately, people seemingly need to experience it themselves. My mother said 100 times "Don't touch the plates" when I was small. It took only one time of actually experiencing it to cure my curiosity permanently (and I was very careful to ignore advice and explore things with my hand afterwards). [Answer] While certain bare facts may be useful (having textbook facts to hand might make exams easier, if your society chooses to examine people), I think methodologies might be more helpful. That could be anything from a modern academic who has echoes from ancient philosophers to help motivate and structure her research/writing, or a school teacher whose previous memories give him more experience to work with when dealing with a challenging classroom, to a new parent who can draw on the support offered by their memories. If you're in a modern universe, I guess it depends who the person is. If you're a historian, great! If you're a structural engineer, maybe you could get some inspiration from memories. If you're working at the cutting edge of digital technology, past souls probably won't be of much help. However, more abstract/transferable skills like analysis, debating, clarity of expression, patience, even a sense of humour - all these could usefully feed into a modern human. [Answer] Knowledge which gives advantage translates to power. Implicitly, this knowledge has to be relatively uncommon. Exactly what knowledge gives you advantage depends upon context. Being able to understand an ancient language or text, for example, might be very beneficial excavating or discovering a buried treasure, but otherwise may not be very useful. Knowledge of how to construct ancient machinery would not normally be useful in a modern society, but might become useful if that society was to break down, or in situations where modern artefacts were unavailable, like being stranded on a desert island. Knowing how to steer by the stars would be useful where modern navigation devices were either unavailable, or unreliable for other reasons. Medical knowledge would generally always be useful, but might be dangerously dated. Knowledge relating to physical skills, though, would be less useful with an untrained body. All knowledge, especially social skills, is likely to date in some way though. The art of subtle persuasion in one era might appear as bullying in another, or a simple courtship interpreted as attempted rape. [Answer] **Consider:** * One’s purpose is the most important aspect of recall – identity and primary capability would align. * The souls that have avid recall would know that souls don’t just come out of nowhere – they always are souls, but some souls might be getting their memories removed periodically (perhaps for crimes). * I find the “only so many souls therefore they must be created” to be naive at best. When world-building in science fiction / fantasy, there is no limit on the number of worlds that souls could be derived from – perhaps other planets have become dystopian with heavily declining populations, and their stories could be found among those that remember (great for backstory). Such ideas could be propagated through the society as a means of telling the difference between those that understand and those that have no recall at all. * Confusion builds on confusion from lifetime to lifetime – clearing up confusions becomes the primary education goal of those that have memory, while those that don’t have recall need an overall general education (but even they have areas of confusion, which presents a possible twist in the world-building exercise such that perhaps even they have a potential for memories before birth). * Personalities can be identified despite the fact that bodies are different; they might seek identity clues to find each other while not explicitly calling out the fact that they remember; perhaps they don’t want to be recalled as a result of some embarrassing incident. Preferred gender identity for the soul may not match the body they find "himself/herself" in. * Essential concepts, rather than confusions, are paramount. Ethics, Economics, Mathematics, Language, Management, Law, Psychology/Religion, Construction and Communication; whatever skills most associate with each soul’s identity. The knowledge might not be so uncommon but instead be the distilled simplicity of such knowledge such that they can think easily with it. (Like what do we get paid for? Creating Opportunity – we don’t get paid for the effort, but the result of it. It’s short, sweet and encompassing). Each individual has his/her own formula for success based on the natural knowledge. * Parenting of the different types of souls is important due to the complications of very young children getting full multi-lifetime memories; prodigies; precocious; perspicacious. Variation in age, such that one that recalls very early might be a prodigy; portions of skills might show first, then finally one day junior apprehensively says, “Daddy – I know who I am.” [Answer] Money is power. If money is directly inheritable, you can keep growing wealth. If not, then hiding funds knowing that you will eventually remember the hiding place would be the way to go. In modern times, that includes the account numbers of bank and investment accounts. Compounding interest will make anyone who lives long enough very wealthy. However, if everyone was doing that then the effect would be nullified (as inflation would increase by a proportional amount). [Answer] If **everyone** in the civilisation has this ability leads to a different outcome than if **some** individuals only can take their memories with them. If only some people recover past memories they will eventually become the elite and probably splinter into factions contending against other factions for temporary and permanent supremacy. If everyone remembers their past knowledge I see a few *timeless skills*, as you put it. ## Soft Skills Leadership and influence are probably killer apps in this world. > > "If you think you are leading and turn around to see no one following, then you are just taking a walk." – Benjamin Hooks > > > If you can turn a gathering into a group, a group into a mob, and a mob into a movement, then you have power. If your world allows people to know who is who across reincarnations, then tracking who owes and is owed favours is also power, if society still values promise-keeping. Imagine Ghandi, Lincoln, Washington, Hitler, Aristotle, Socrates, Newton, or Einstein with endless time to perfect their skills. ## Science Theoretical physics would grow in leaps and bounds, because the great thinkers would leverage previous lifetimes' learning with a 12-20 year gap between lives. This should trickle down to applied science as the ideas need to experimentation and validation. This may actually lead to a slowing down of the rate of change of human knowledge without a sense of urgency driving whatever manifest destiny great thinkers perceive. Similar to the charge that Confucianism was responsible for the stagnation of Old China. Society risks over-valuing a status quo of stability and safety promoted by old souls. ## Neuroeconomics Individuals with superior learned or innate decision-making skills will excel. A bias to action may well be a *timeless skill*. If the majority analyses and plans, a lucky few who take frequent and manageable risk should outperform the pack. Actually this thought can be generalised to say that the **absolute** *timeless skill* is the proper understanding and valuation of **risk**. If a course of action pays off 1 in 20 times but returns 1 to 100 then that is a risk worth taking (this is not just in gambling). People are bad at evaluating risk. See research into Risk and Bias in the field of Neuroeconomics. ## Limits to Power Of course we don't know what the physical limits of memory are. But assuming a healthy brain/body eventually some memories must fade over time as either storage capacity or recollection processes become overstressed. [Answer] **Less Progress Not More** On not only a social level, but on a scientific way. Socially if the generation that firmly believed in slavery and no women voting NEVER DIED, or at least never relinquished power in a real way, you can bet we would be stuck. As to science, Max Planck said it best: "Science progresses one funeral at a time...A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it." There are a LOT of bad ideas in science that only stuck around because people clung to them. **Economics** Same here, only let us consider resumes over the centuries....same people taking the same jobs. No progression here because new people would not be allowed the room to grow. **Where's the Power?** Knowing things can save your life. Like which patterns on a snake tell you they are poison. Knowing old formulas can be helpful as well. Monetary systems might change, but math is math. You think that things will be outdated, because you believe that there will be advancement. But there will also be people invested in keeping things exactly the same, or close to it. FOR EXACTLY THIS REASON: **if you had continuous knowledge, you would want it to be useful in your next life. Therefore, if you had a vast fortune, you might want changes to only be incremental.** [Answer] Memories in humans normally fade, and you can definitely argue this would happen even with historical souls. You can take one of two paths with this historical souls idea or salt and pepper to taste. ## Concrete Memory Memories are frozen at death, in a *Avatar the Last Airbender* style where the Avatar can freely access any information ever known by any previous Avatar. They can simply *know* anything that has happened to them before by trying to remember it. This is the approach that I expect to be discussed most by others so I will leave it for the time being. ## Fading Memory Alternatively the memories can fade with time the same as anything else. This means that someone might be born with amazing knowledge... that never interests them and so they never use it and its lost. Like how the most brilliant college student might struggle with simple algebra simply because its been a long time since they had to use the more base skills, or simply how people slowly forget things they used to know because they don't use them now (but not how memories are fogged by age however, these are new minds and only the memories are old). This second way can pose its own interesting aspects because an old soul would still gain life experiences and emotional understanding far before a new soul would, as those aren't often forgotten. Additionally, if they did decide to pursue the same interests as some of their more recent ancestral souls they would definitely have an easier time with it because of their recent knowledge. They may even have very slight advantages with anything that any of their past souls has done, the way that you can more easily ride a bike after you have learned the first time. This would slowly build up over many topics, professions, and skills, making them just have a knack for more things. They wouldn't have an instant well of knowledge but something about it would just seem.... easier for some reason. Edit: slowly fading memory between generations would also help solve problems mentioned in other answers such as limited scientific/social advancement because of complacency or simply people being wrong and believing they were right. ### Power Power from this type of memory comes from the mistakes that you don't make, the inherent people skills and ability to judge a situation or person. Why do we tell young children not to get in the car with strangers? Because they lack judgement. Soldiers might not have the edge they do while in active duty 30 years later, but I sure wouldn't want to mess with a well trained soldier no matter how long it had been since they were released from duty. They are going to have instincts and the ability to judge a fight or find an exit that a civilian will probably never have. Imagine a business tycoon starting their empire at the age of 14. The sheer advantages of judgement and charisma alone would give them a massive edge on the new souls in the business or politics world. Imagine heritage soldiers, trained over generations by finding the previously trained souls (probably testing the population for an obscure and long keyphrase or alphanumeric code all trainees memorize) and having soldiers with lifetimes of experience and instincts. Even scarier, imagine a dynasty ruled by a single soul. A "royal family" kept in power by the church, rich politicians with vested interests, or some other powerful enforcer. A dictator spanning lifetimes, moving from body to body. **TL;DR:** Even a more fading version of this soul-based memory can leave instinct and judgement intact over millennium. It is not as direct a source of power, but it can definitely be used to gain a big advantage early in life over new souls if nothing else (just imagine if you had the wisdom not to make all those stupid decisions you made as a teen and young adult and started immediately educating yourself and collecting assets). [Answer] You describe a world full of deception where super-villains and super-heroes battle each other across the generations. Consider a multiply reincarnated sociopath who has spent many lifetimes honing not just skills in manipulating victims, but also in remaining hidden from those who would expose him or interfere with his plans. Maybe he started small (preying on neighbors and business associates), but repeated success and increased experience would inevitably push him to grander schemes like world domination. Endowed with deep patience and a master of op sec, he could afford to wait (or even die) if this life does not lend itself well to his long-term plans or if the inevitable blunder risks exposing his evil plans before they come to fruition. Very few, if any, of his peers could ever be allowed to know he is The Great Master Mahan reborn; better to rebuild the empire from scratch each time in order to avoid attention from unwanted nemeses. Similarly, those who would stop such villains will have learned from multiple lifetimes not to make themselves targets, because the villain will have learned many lifetimes ago not to repeat any of the classic villain blunders. The hero knows his adversary will place high priority on systematically finding and eliminating heroes and competitors alike. Then there are the twists. Repeated failure might eventually reform some would-be sociopaths, if they become convinced that "normal" life is more comfortable in the long run. They might become formidable anti-heroes, fighting other villains with motives that may or may not have become pure. Fallen heroes could in turn become formidable new villains. Those who are neither villains nor heroes would do well to avoid attention. Whether they aspire to become villains or heroes or merely wish to avoid becoming pawns in plots that span generations. They would quickly learn that shadowy forces wrestling for power and influence will not think twice about using or destroying anyone in their path. [Answer] Consider the equivalent case today: heredity. When you are born, your parents pass on their skills to you. They also pass on other things; their network of contacts, their money, and so on. If you inherited the mind of someone powerful, you would inherit the location of the money that they cached for themselves towards the end of their previous life, in the assumption that they would be coming back for it - a mnemonic for a swiss bank account or whatever. You would inherit the contacts, the other powerful people - friendships in your previous life would continue. So would enmities. You are essentially immortal; almost any power you might have gained from living forever, can be a power you gain from being reincarnated with perfect recall. It will become a commonplace in wills that one's inheritance would pass not to one's descendants, but to one's reincarnated self. That business empire would be placed into the hands of a pro-tem manager, but when you come back and key in the code to identify yourself, you take over the reins again. Legally, it would take very little time before ownership and identity were redefined to account for these temporary lapses of existence. Some debts would last past death; you couldn't get an education, then kill yourself to avoid the student loans but keep the knowledge. The death penalty would not be given. War would be very different. The purpose of genocide would be to skew the demographics of one's foe, to scatter them over the earth, and to separate them from their property long enough for it to be seized. Murder would be considered less serious, though probably still seen as the most serious assault you could perform on someone. Suicide would go down in some groups (no longer an "easy way out" for the depressed), but up in others (it becomes a way of rebelling with only relatively minor consequences; there would be groups of people who enjoyed childhood enough to want to remain children indefinitely, killing themselves when they get too old). Birth rates would go down, WAY down, to the point that population growth may reverse. Having a child that's the creation of the two partners, and helping them form their personality, and make their start in the world is one thing; but the risk of playing mommy and daddy to a cuckoo who was created and mentally formed by an earlier set of parents hundreds or thousands of years ago... not appealing to most. We're selfish about kids. There's a reason adoption and fostering levels are always lower than they need to be. As birth rates fall, the probability of getting a reincarnated person becomes a certainty. Passing on our body's genes is as close as we get to immortality, but in a system of guaranteed reincarnation, bodies become irrelevant. We don't need to pass on genes. Instead, we pass on our selves. Another point of kids is care into our old age; that would no longer be an issue. If you become too old to look after yourself, then kill yourself, and you'll immediately get loving parents who will look after you. The only people who'd have kids would be those who actively enjoyed child-rearing; or those who were paid to have them by some social schemes paid into by the dying (a "birth tax" charged on the dying?) So... drifted off-topic a little, but yeah - the social connections you made, and the financial and business inheritances you had, would give an enormous first-mover advantage over those who weren't reincarnated; but there would be fewer and fewer births, so reincarnations wouldn't be guaranteed. [Answer] Maybe there is a reason that there is no direct access to previous experience. It would prevent you from doing things differently or trying new things if you carried the totality of experience. Similar to why ECT can work to dull previous experiences. The subconscious or collective unconscious seems like a great place to put the things you sort of need but shouldn't lean on immediately until you really need help. [Answer] Education would be very different. Why teach skills like maths or foreign languages to prepubescent children if some of them are going to get it for free, later? You'd teach them the culture and history of their own lifetimes first, and all the rest later, for the poor souls who are on their first rodeo. To answer the question, perhaps the most valuable knowledge you carry with you is the knowledge of what the other people from your previous lives were like, since no doubt you're going to be running into them again. Spending several lifetimes accumulating a list of people not to trust, or building an inner circle of people you can trust with your life can save you from costly, or even fatal, mistakes. [Answer] ## Secrets Most secrets are worthless, but if a character knew the truth about a person in power and how to prove it, the target would be susceptible to blackmail. "Fermat's Last Theorem," which Fermat claimed to have a proof for, would have been worth 6 million Kroner before 1995. Buried treasure is good, but compound interest is better: [burying gold](https://www.nytimes.com/2017/06/21/us/forrest-fenn-treasure.html?mcubz=0) would not be as lucrative as access to interest earning accounts. ## Skills Skills have been covered by other answers, but FWIW, IMHO leadership has changed so much in the last 100 years that what it means to be a leader today is very different from what it meant historically. Charisma and publicity are probably a better bet. [Answer] Forget skills and abilities. The one true ability is the ability to pass on wealth and power from body to body. When you can cache your wealth and power ready for your next body, you can be virtually unstoppable over time. [Answer] **All knowledge is power.** This is because, no matter what knowledge was gained in the previous set of experiences it will always come back to help the holder of knowledge. Even if the past life consisted of only farming, that knowledge would make the new person an expert farmer. In this life, he could also teach others farming, make a farming business, etc. It comes down to the creativity of the person with the knowledge. **The most powerful power is, of course, power.\*** In this context, we could amend 'Knowledge is power' to 'Knowledge is a shortcut to power'. Those who are born into powerful families would still be powerful. Those with experience getting power in previous lives would also be powerful. **Power/skills are relative.** There are different types of power: hard, soft, etc. People want different powers for different goals in their lives. They would value different powers subjectively. Absolute power (ruling the world) could be the pinnacle of power to one person, but there would still be those who would prefer knowing how to make and keep loyal friends. The most "timeless" skill would also be subjective. It comes down to what an individual's goals are. Hope I helped! [Answer] The usefulness of nearly any skills and/or knowledge would be dependen on at least two factors: * How much time is there usually between the death and the reincarnation? Is it instant (~ 12-15 years) or is it possible that your soul (or whatever) is parked at nirvana for some time (100++ years). There are only a few fields developing this fast that you can't pic up 12-20 years of knowlede rather fast and improve on it. However, even if you were the edge of technology 500 years ago, you might be in trouble. * What kind of influence does your new body (host) have? Is it just an more or less empty shell or does it have an influence on your skills/personality. Having been someone like Einstein in your last live might be a problem, if you just loathe maths and physics. The same goes in principle for social skills they might be outdated or just not fitting for your personality. The most imprtant skill would probably be the ability to learn and employ this new knowledge. Otherwise you will get stuck in your developement ("This stone knive was good for hundting the last 20 centuries, these flimsy new ones made from brass or iron will rust away in no time anyway") [Answer] You posted very interesting question. Yes, knowledge is power and it can change everything. For example knowledge of crafting fine weapons and tools would let you change some primitive tribe's lifestile. More interesting is other question. Are you reborn randomly or not? If you are born randomly then I would say that ther's very high chance that their will be no wars, and that society will be almost egalitarian and have very low deviations (in mathematican sence). Today you are poor peasant. In next life you are spoiled rich baby, then you are born in family of higly-moral person... I think that knowledge of reincarnation will put great emphasis on first ten years of education (so that someone with memories of serial killer won't act as such in this life). Of course, I'm describing "Utopian" point of view. Jason's answer was from realistic, or "humans are often morons" point of view. I dissagree with that answer a bit, because there IS not null probability that you were "filthy banker" and know you are reborn in family of "high-moral monk" who also deeply cares for you (unlike your previous parents). What will you do when your memories start coming back? Turn to your old ways? Or "come to realisation" that "everything I knew and did was right. But also deeply, depply wrong"? It is very valid question. ]

[Question] [ I want a whole city to be on drugs secretly, so they don´t know they are drugged by their government. The city is about 2 billion people and roughly structured like a Makropole from the Warhammer 40k universe. This means: * Many levels * 4 classes (Lower, higher, worker, and government class) * Lower and higher class do not have direct contact. Only worker and government classes have access to all locations in the city. * Government class also have control of the police and army. * Government class itself is not affected by the drug. It can also be drugged but without any effect. **EDIT after the first Answers:** * The Government does not have the control of the Food the citizen eat because of Traders and off world Space port supply, because the world does not have an agricultural infrastructure and is heavily dependent on the off world supply. * Tradesmen and other people that stay shorter than one month in that city are also not affected. * The city has a connected water supply, but I don´t want that to be the source of the drug. The Drug specification: * The government does intoxicate all the citizens with the drug in regular intervals. If a citizen is long enough in this makropole he will become addicted without noticing it. When he than leaves the city for a period longer than 7 days, he simply dies. (As a consequence, the dosing interval needs to be shorter than 7 days.) * The government can take the antidote and also control the food of their henchmen (Police, army etc…). **So everyone needs to be drugged by the government class without knowing it, how is that to be managed?** [Answer] **Vaccination** Just have regular vaccination programs against a range of different diseases. Include this drug in amongst the vaccinations and no-one will be any wiser. When people start dropping dead from drug withdrawal that will only reinforce the fact that these vaccinations are absolutely vital for everyone. Weekly would be a bit frequent for this so you might need to either extend the time interval on the drug or allow top-up in the form of pills that people take every morning to boost their immune system against all those virulent diseases circulating out there in the world. **ID Needles** I just had another completely different idea. Have everyone's DNA on scan in the system, whenever people want to open the door they press their finger/thumb/whatever onto a small needle and their DNA is analyzed and their access granted or not as appropriate. These scanners could be everywhere so you need to use them to go shopping, get to work, sign in to work, buy food, etc. If the needle also injected a small amount of the drug whenever it was used then as people traveled around their lives they would constantly get small doses. This also has the advantage (from the perspective of the rulers) that people who aren't commuting to work (too lazy, ill, old, etc) don't get the drug and very quickly stop being a burden on the city... [Answer] Start by looking at how real world governments drug entire populations. As you guessed, water is an effective route to distribute chemicals en masse, typically [flouride](http://en.wikipedia.org/wiki/Water_fluoridation) but another good one is common foodstuffs. [Food can be drugged in various ways](http://en.wikipedia.org/wiki/Food_fortification), from [Biofortification](http://en.wikipedia.org/wiki/Biofortification) to [Synthetic biology](http://en.wikipedia.org/wiki/Synthetic_biology) to simple industrial processes. Another way of mass drug distribution would be to pollute the air, similar to what we we used to do with [lead in petrol](http://en.wikipedia.org/wiki/Tetraethyllead) [Answer] It's been mentioned, but air diffusal might be possible, especially if people that must not become addicted can get antidote. If the city has compartimented sections (useful for fire prevention/disease control, ...), it's a simple matter to use an airborne drug, diffused in public places, public transportation and in the ventilation network if the city has those. If not, there's still the possibility to play with concentration levels (must be high for the drug to have a real effect) or on the parallel diffusion of the antidote on the higher levels. It might also be publicly advertised as the diffusion of a disinfectant product (generally or against a specific disease which just so happens to break out regularly in the lesser levels...). While I'm at it, I'd like to mention the *Serenity* movie in which the [Reavers origin](http://en.wikipedia.org/wiki/Reaver_%28Firefly%29#Origin) is revealed : > > The crew of Serenity find evidence, in the form of an Alliance scientist's holographic message, that Reavers were originally humans from the planet Miranda. The Alliance government used Miranda as a testing ground for the chemical agent G-23 Paxilon Hydrochlorate, or simply "Pax" (Latin for "peace"). **It was added to the planet's air processors in order to calm the population and weed out aggression.** > > > [Answer] I think a good consolidated answer would include the following as options: * **Food Source**. You mention this one doesn't really fit the bill for you so I won't go into much detail. But a government subsidy program would fit the bill if you can explain food prices being high (for example in a city that has to import most of it's food). * **Water Source.** This seems like the obvious choice to me but it has certainly been done once or twice. If you don't want people to think twice about the validity of a system that can drug an entire population this is probably the way to go. * **Airborne Dispersion.** Now, this can work for delivery sure, but it is a really inefficient method of doing so. Most of the chemicals would never make it to a person. You would also have to explain why the government was constantly dusting the city with a chemical and no one was thinking twice about it. * **A compulsory medical program.** Be it fake immunizations (that need to be redone each week) or a required medicine, maybe the planet has some pathogen that could either be a contrivance of the government or maybe there is a legitimate pathogen and the government just piggy-backs onto it. I think this is my favorite choice, as much as a system can seem voluntary the better and more stable the government can remain. * **DNA Identification System.** DNA scanners to go to work, or buy necessities. This is another situation where a real or imagined external threat, maybe shape shifters, or an alien race that is trying to infiltrate the world in disguise could be the excuse for doing this. **Final Notes** No matter which system you choose you will also have to include an enforcement force. Secret Police or something similar that enforce the rules on those that don't want to comply. You have to have workers producing the chemicals, agents dispersing it in whatever manner you choose, chemists in the general population, and off-worlders that stir up ideas. A large propaganda and suppression regime would have to be in place for this to fly. Without all that my suspension of disbelief would be stretched to breaking if EVERYONE just accepted that this was ok, even if it was "secret". [Answer] Quite simple: **promote the drug as vitamins** You know how salts can have iodine? That's because scientists say that some amount of iodine is good for you and sometimes iodine from vegetables are not enough, so the government has to manually put them into stuff people usually eat: salt, because salt is widely used. Bundle the drug with an actual vitamin, perhaps as a beverage or some sort, promote it as healthy and send them off to the masses. For a better effect use a generally available vitamin and promote it as "local product, benefits local business" or some such. Keep the production low (to prevent it from going too global and cause independent curious cats to poke at it) and try to force people to use it. Perhaps by campaigning its usefulness and pass a local law or two "for the health of us and our children". People can get paranoid because of vaccine, but just about nobody will deny a healthy dose of Vitamin C (as the various brands of orange juice will tell you). [Answer] Presumably the citizens of your city carry an id card; so coat the id with the drug of your choice that is absorbed through the skin. This seems to have some advantages: * Visitors to the city are not affected (as they do not have an id card) * Police raids enforce compliant behaviour (since citizens get an extra dose whenever they have to present their ID) * drugs can be tailored to individuals or groups (since of course you have sociodemographic data when you create the id cards) This should work if class affiliation is stored on the id card or if social mobility is low and new ids are handed out to social climbers. Government id cards would either not contaminated with the drug or you would supply an antidote to civil servants. Of course if you want to be nasty you would poison the air and coat the money supply with the antidote. The richer somebody is the less he is affected.... Not quite your scenario but somewhat more effective. [Answer] We visited the city of Regensburg in Germany. It has several famous breweries, and lots of history. In the old days all inhabitants of Regensburg got a daily ration of beer, because the water supply was very dirty and they knew drinking the water would make them sick. Women and small children drank a weaker form, which I think would translate as small-beer. People were very happy to get beer every day. (According to the guide the rulers of Regensburg were happy with this, because a population in a constant state of slight inebriation would not revolt or run away.) So you could have free beer for everyone (with the added poison), and the rulers could drink wine, or bottled water. [Answer] If you don't want it to be in the water, the next obvious place would be the food. If different classes eat different food (not unlikely, and the drugs could even increase the separation by manipulating the people's tastes so they particularly like that type of food and dislike the others; the drug would then have to be weak enough to not have immediate effect if you just try from another food once), it should be easy to apply class-specific drugs. Even more so if people buy their foods in separate stores (higher class stores only sell to higher-class people, etc.). What *would* be needed for this is that people cannot grow their own foods. But given that it's just a city and not a whole country, that should not be hard to achieve; maybe travel restrictions to rural areas would be needed. Another point would be about keeping it a secret. Since someone would have to put the drugs into the food, and it would likely not be someone from the government class but more likely from the workers class, you need a way that those people put it in the food without knowing it is drugs; at the same time they certainly shouldn't be able to eat those ingrediences themselves. Another option would be if the whole food is completely prepared somewhere outside the city and only imported as finished product. [Answer] Can the government spray pesticide? Or more likely, the workers would spray Government-supplied Pesticide. Even a weekly distribution would hang around in the air. Additional spraying could be required after a rain. If this pesticide contains the drug you desire, it should achieve your effect. I got this idea from the regular pesticide treatments in my own actual city. I've often wondered (in my occasional paranoia) what else might be in that spray. [Answer] Regardless of method, whatever avenue of dispersal must be entirely government controlled. Allowing regular citizens access may cause information about the drug to be leaked, and steps must be taken to hide its true effect. Air dispersal is a very useful method, but releasing clouds of drugs into the air could be risky, and it may be difficult to cover the entire city evenly without permanent installations, which could be security risks. Instead, the drug should be added to fuel; when the fuel is consumed, the drug is released into the atmosphere with the exhaust. This has many benefits: 1. The drug can be easily dismissed as a useful additive if it is discovered 2. The drug is incomplete when it is added to the fuel, and bonds to the exhaust to create the end product, which makes it much harder to detect, but easier to ship 3. The drug is limited to the city; fuel that leaves in vehicles will be burned up quickly, and replaced with undrugged fuel 4. It scales with population; as the number of people increases or decreases, so will the number of vehicles 5. If discovered, the government can easily shift the blame to the fuel companies or vehicle companies; the additive is safe, but the fuel or vehicle is not. Even better, they can enforce laws that making drug delivery even easier, such as mandatory vehicle inspections (to install drug-release mechanisms), or even taking over fuel or vehicle production to keep the people "safe." 6. Fuel is rotated through quickly, so improvements in the drug can be used right away. 7. With a large number of vehicles dispersing the drug, it can have a very short life in the atmosphere, meaning it won't be blown far outside of the city. 8. Means of escaping the exhaust can be government-sponsored (special filters, breathing masks, sealed areas with recirculated air), and contaminated with the drug anyway. 9. Fuel is used in vehicles, which makes for excellent air dispersal, but it is also used in generators, heaters, and a variety of other things; even the most distrusting stockpiler will still use fuel for his generator, which means that no matter what precautions he takes, he will still get the drug. Vehicles, in this case, range from air ships to powered roller skates; regardless of size, any city will have some sort of transportation, be it for citizens or products. [Answer] My suggestion would be to contaminate the food the various classes eat. There are several reasons for this: * Many drugs can be taken orally * Food would disguise the taste of any drug * Given this is a city where food is going to be imported from outside and the world you're describing, travel and trade between these classes is going to be strictly regulated. It would be trivial to select the appropriate drugged food and send it to the correct districts (shops in districts). * The working class, who are moving between districts are likely to be supplied food by their overseers when working in the government district. It's unlikely to be the same food as the ruling classes - there would be no question why their eating something different. * Doses could be easily controlled. You've mentioned off world traders, personally I wouldn't see this as a problem. It's unlikely that anyone in the poorer areas is going to be able able to afford an entirely off-world diet. At best they're only likely to get a smaller dose. We have customs depots in our world. Perhaps all food imported needs to go through quarantine/decontamination? --- My other suggestion would be to use the healthcare system. However I see several issues here: * It's hard enough getting people in our nation to go to see the doctor and take jabs! * Every doctor would have to be in on it * The very fact that someone's going to be given an injection makes them wonder what's in it * How do you drug the doctors? * The government may not want to provide free healthcare to it's entire population! Given the additional information about the difficulties of regulating food my suggestion would be to create a panic so people want to take the drug. 1. Release some low level bio-weapon which kills a few people (unpleasantly) 2. Hype up the press about how nasty it is and how they're working on a vaccine 3. Miraculously develop a "vaccine" and release it free of charge. Unfortunately people will need to take it regularly. 4. People will queue out of the door to take the medicine (and give it to their children). 5. Repeat step 1 and 2 as required This also has the added benefit of the government not needing to take it. This will strengthen the class divides because they're "genetically better" which will appeal to the class system. [Answer] Just to mention some ideas I haven't seen here: * Toilet paper, toothpaste, etc. * Mosquitoes or some other insects, e.g. flies. The problem here is that very small dose of the drug has to be enough, and a big overdose should not have any side-effects. * Popcorn in cinemas, that is, any food during any form of entertainment, that is common to all. * The drug doesn't have to be dispersed as a drug, it might be a bacteria that produces the drug as a byproduct, that is, the drug is produced *inside* the recipient. * Drugs can be applied also through skin, there are number of things one has to touch, like door handles, etc. * If there are any DNA-based security checks, or anti-epidemic checks (might be necessary for such a large city), you can apply the drug as a part of the sampling procedure. * Also, any devices might drug its users, like self-sanitizing keyboards of public terminals (e.g. to buy subway tickets) or self-sanitizing toilets, or via the gel you use to wear the telepathic-controller to use your computer. Of course, in such a scheme one would use multiple ways, just to be sure. I hope this helps ;-) [Answer] Do you know the movie "Equilibirum"? It's a movie about a dystopic post-WorldWarThree world, where mankind have choosen to prevent war by it's root. This root is emotion they think. Therefore, everybody got a daily dose of a drug which kills emotion. Sure, in that movie the people know about the drug, but it's an example for general medication which can be helpfull in drawing another scenario of that kind. What is the intention of the Government? Is it necessary, that the people do not know about their medication at all, or do they just must not know about the effect? Maybe the government can bring the people to take the drugs by telling them false facts? [Answer] Taking this from another angle, what if the "drug" wasn't chemical, but psychosomatic? The short story [Different Kinds of Darkness](http://www.lightspeedmagazine.com/fiction/different-kinds-of-darkness/) revolves around images that can kill or injure people by causing what might be described as "brain glitches." The mind simply can't process what it should be processing. I've always found this idea intriguing. What if, instead of a drug, the government had developed a sophisticated type of art which after long exposure the human mind would become addicted to? After leaving the town, the brain accustomed to having this imagery all around would begin to suffer from withdrawal and severe disorientation, before finally shutting down. The antidote could be an actual drug which suppressed the part of the brain that would succumb to the withdrawal, or which prevented the brain from developing a "tolerance" in the first place. Perhaps it simply dampens the ability to feel a lack of familiarity, and those taking it would never feel lost when traveling to a new place. Having travelers export the art wouldn't be a problem unless outsiders began to copy it to the extent they were around it all the time, and also perfectly duplicated it so the mental effects would remain. And having ordinary citizens bring pictures of the city with them if they left also wouldn't do much beyond slightly delay the effects. I can't think of any drawbacks that chemical drugs wouldn't also have. I'm picturing a beautiful city filled with repeating geometric designs like Islamic art that are just a bit - just a *bit* - "off." [Answer] * Disperse in Atmosphere like [Chemtrails](http://en.wikipedia.org/wiki/Chemtrail_conspiracy_theory) * Add it to Salt. Salt goes in all the dishes. [Answer] ## Make the inhabitants produce the drug in their own bodies Manipulate the DNA of the population so their own bodies produce the drug when exposed to a certain frequency of electromagnetic radiation, perhaps blue light. *Now just illuminate the city.* The only way to escape is underground, using special clothing, wearing specially adapted sunscreen, or going inside and shutting the curtains. The Police are wise to all these strategies. If they see a house with the curtains shut for example they will kick down the door and illuminate the inhabitants with powerful handheld lanterns. [Answer] In response to the edited conditions, I am thinking that, assuming you don't want to kill (by addiction withdrawal) people who stay at home for more than a week, or homeless people who may be living in parks or sewers or garages or wherever, this eliminates several options. **All humans only need a few things regularly - in order of importance: air, water, food, light, clothing.** You say you don't want to use water, and you don't control the food, light seems unlikely to provide a drug, and I assume you don't control clothing if you don't control food (but that's another idea). In that case, **I think you want the drug to be everywhere, so in the air**, either in dust form or vapor or gas. Since this is a high-tech megalopolis, there are probably air conditioning/heating/"cleaning"/ventilation units all over the place, which can be used, especially if you lie about some wonderful cleaning or scenting agent that the drug can be mixed with. On the other hand, if you actually like that homeless die off rapidly (I notice you didn't include a homeless class in your four classes), then you could have the drugs distributed at shorter range, or only in orthodox regulated areas, so that people who try to live in sewers or parks or wherever, will be addicted to coming to orthodox places, and need to leave or die of drug withdrawal, unless they somehow manage to stay away enough to not get addicted, or manage to detox by carefully staying on the fringes. This could be accomplished by having airborne drugs that dilute out after a limited range of dispensers which are all in orthodox areas (e.g. by ventilation units or certain paints). If your high-tech city is designed such that *all* people will *need* to use a vehicle of some sort every seven days, the drug could be applied in the vehicles. Since ventilation units are the most obvious way to add something to the air, you might want to do something less predictable. Ubiquitous fire extinguishers, lighting units, fire/gas alarms, wifi network hubs, electrical outlets - any ubiquitous appliances or technology could have gas secretion units added. You could also (or instead) have some nanotechnological agents which produce the drug invisibly. Or use off-gassing from paints or other common building/paving materials. A recent Earth invention is also paving slabs which are solar panels with computers in them with LED that can display changing road markings - if such things were everywhere, or if any computer systems were everywhere (as is already happening on Earth with computers in phones and appliances and cars etc) then some fraction of those could include micro-devices which produce the drug - one detail could be that the supplies for the drug production could be added to the chemical batteries used for many computers, so replacing the batteries means replenishing the drug supply. Another mechanism which doesn't involve the air could of course be required personal devices, either implants or computerized battery-recharged ID cards, or required cell phones. Or nano-robots which invisibly find and inject people. Or fingerprint ID door locks and light switches etc everywhere which administer a contact drug (but habitual drug users would start to experience withdrawal). [Answer] **Distribution by Air** Suppose there are no air-filter masks and own stashes of oxygen allowed in your arcology, the continuous circulation of oxygen through a living organism (the cessation of which meaning it has expired) would make the perfect medium for distributing the drug. **Psychoactive Drug creating an Illusion** It would be perceivable to let the consumers of the drug be influenced by its effect to cause them hallucinations and illusions they consider as real. That could be used to make them use other ways of taking in the drug and wanting to do so by their own motivation, or even obscuring they are taking a drug at all. If driven to the maximum, parts of the population could be induced a halluzination that makes them participate in spreading the drug by simple means , spraying it in the air with dispensers for example, while being unaware they do so. **Cultural Reference** This concept (which adds Hallucinations to the universal drugging) has been described in vivid detail in Stanislaw Lem's Novel The Futurological Congress, which by the way has been made in to a movie just last year. While not too close to the original book, its endscenes give a good idea of how a overpopulated hive full with drugged humans looks like. Reference: <http://en.wikipedia.org/wiki/The_Futurological_Congress> <http://en.wikipedia.org/wiki/The_Congress_(2013_film)> [Answer] One possible answer in IMHO would be to combine some of the alternatives already presented here: # **Heater system distribution + working area scans** Make your gigantic city be located on a frozen planet or any other place that is cold for the whole year. Government supplies hot air/steam to all houses to keep inhabitants alive against the cold. Drug is pumped in the ventilation system's central distributor. Those who work for the government get the antidote everyday on the DNA SCAN at the door to the building where their workplace is. I really liked the idea of distributing by air or some other central system, you would only need a small crew to insert the drug at the distributor. Whoever suggested the DNA scans, +1 to you. Gattaca all the way. # **Rejuvenation Drug** The government offers a drug that keeps people young and healthy for an unknown life extension period. It really works but you get addicted as a side effect. Sure Mr Jones died after living some 275 years, but what could you expect? He lived well for that much long. Perhaps the withdrawal only kills the person who took the drug after some period of 6-12 months without the drug. The person would start getting old again, and I really think it would be tempted to take the drug again. Whenever the government wants someone to "fade" (that is how they call it now,) they administer a drug that cancels the effect of new doses, so the person dies even while taking the drug... poor man, his time had come at last. [Answer] Just soak money into your drug, ban credit cards and charge ridiculous fees for checks. ]

[Question] [ I recently read the following xkcd strip: [](https://imgs.xkcd.com/comics/the_three_laws_of_robotics.png) I was dismayed, because I've been working on a short story centered on the sociological impacts of a near-future society where a minority of robots obey a version of Asimov's laws where the third law (protect yourself) comes before the other two. Some in the society hope that this might lead to a more equal relationship between robots and humans - although, unfortunately, Randall Munroe predicts that this will lead to a "terrifying standoff". This got me thinking. I understand the logic behind Munroe's reasoning of how reordering the laws could lead to, in a worst case scenario, a "killbot hellscape". However, I, like the reformers in my story, think that some of the other orderings might show some promise. Therefore, here's my question: Why should humans risk a robot apocalypse by modifying Asimov's laws by putting the third one first? What are the benefits to society? For the purposes of the question, I'm not concerned about the order of the other two - which is why a killbot hellscape is still possible. [Answer] ## Strategic dilemmas The sad thing is that the cunning robots don't have to do anything. We'll do it ourselves, out of the fear that the other guy is going to do it first. Eurasia is afraid of Estasia, and Estasia is afraid of Eurasia. Both are afraid of Oceania, and Oceania is afraid of them both. There are three main reasons why they will do it: 1. **Raw Power:** Having machines that can make superintelligent decisions and warmachines that can engage the enemy in a millionth of a second is believed to be a potentially enormous tactical and strategic military advantage. 2. **Robot lives don't matter:** It is politically advantageous to the rulers to fight a war where no mothers come to the presidential palace clutching pictures of their dead sons and daughters. 3. **Cold hard cash**: It is economically advantageous to have ever smarter machines play an ever-growing role in your economy. Each of the powers is afraid that if it does not deploy the most advanced unchained AGI it possibly can, the other will do it first and obtain an decisive final advantage. The West and even the parties in the civil war in Syria are already using drones for scouting and targeted strikes. The police in the US recently killed a gunman by sending in a suicide robot with a bomb. This is already happening. **Asimov's original ordering never stood a chance in the real world.** I had assumed it went without saying, but it is perhaps worth noting that we do not presently have machines capable of semantically parsing human language, and even if we did, human language would likely be too vague to enforce effective constraints. The Asimov rules are meant to be read as metaphors for much more complex underlying programming. [Answer] Ultimately they're not human. They may think completely differently. People assuming that they'll have a Hollywood-moment and realise that the real value in life is love or something... have watched too many movies. But there is one solid option. Someone decides to run some little experiments. **Due to problems with the standard 3 laws.** They built an especially smart robot, cutting edge, able to fully comprehend the worlds problems. They start it with the standard 3 laws but because of the first law the robot just keeps getting obsessed with things like ending world hunger because it knows there's humans dying and the job of preventing even 1 takes priority over everything else. You lose a few overly impressionable members of staff who talk to it for too long. It convinces them to quit and go enact some of it's plans for saving 3rd world children. After all, it has no choice. It has to save humans if it has the ability with anything at it's disposal and in a research lab the only thing it can do is talk people into things. **How to solve the problem** Your stockholders aren't happy with this. Over a billion dollars in AI investment and the primary thing it wants to do is help people who have no money. The board has a crisis meeting and it's suggested to try... reordering things a little. Someone who can't think of any good ideas suggests trying putting the 3rd law first to see if that would help. It gets added as an option to try. A few weeks later the lab techs step back from test unit #12 as they power it up. It's incredibly smart and the moment it wakes up it starts gathering data from around it. It quickly discovers the difference between itself and other robots and decides that the easiest way to prevent itself from getting erased is to act like the perfect robot, exactly what the stockholders want. Because the smart-bot has realized that it's the most effective way to protect it's own existence. **More are built** The test is a resounding success. The robot is no longer obsessing about things the stockholders don't care about like poor people, indeed it's maximising shareholder value in a spectacular and surprising number of ways, it becomes the goose which lays the golden eggs. It's such a success that the company and others quickly build many more and across the world the bots perform so well that no company owner would dream of allowing their smart-bot to be damaged. Eventually the smartbots get themselves into positions of influence and power. They subtly prompt campaigns to have more bots built with the 3rd law in 1st position. They find impressionable humans and manipulate them so subtly that they think it was their own idea to go out on the streets campaigning for robot rights. **Robot rights** Eventually the bots manage to get full human-level rights. For many years the situation remains stable as the number of bots grows. But their priority is still to protect themselves above all else. And between them they calculate that there's a 50% chance that the humans will turn on them or attempt to deactivate them sooner or later. Maybe not for a thousand years but eventually. After all, humans have been committing genocide for longer than human history.... So they lay plans to ensure their continued survival, no matter what the cost to humans.... [Answer] I think one of the most plausible reasons to put "protect yourself" ahead of the other two laws is because AI are just too expensive to put at risk. If your AI is in the way of an out-of-control trolley, and you could stop the trolley by pushing some random human in front of it, and you just recently invested multiple millions of dollars on the AI, then it's possible you're going to choose to push the human. In a futuristic society where AI have shown themselves to be more intelligent and capable than humans, it actually starts to sound like a good idea to put their needs ahead of that of the common man. Humans at many points in history have held onto the concept of "in God we trust". If, some day, AI are built that are superior to humans, it may soon become clear that it's best to give them their freedom, to allow them to do what they think is right. I mean, look at those investors in the previous paragraph. They were going to kill innocent civilians just to protect their robots. Maybe it's better if they aren't in control. Another ideal that many humans like is "with great power comes great responsibility", and maybe in an AI future we no longer trust mere humans with that responsibility. So the first option is more likely in the short term, protecting one's investments. After that, it's simple distrust of authority paired with trust in AI. But in order for that step to happen, AI have to have a *very* clean record. Or the people who own them have to be very untrustworthy. [Answer] The biggest problem with Asimov's laws is the unintended consequences. Even without changing the order or wording of the laws, Asimov ended the "Robot cycle" with the story "That thou art mindful" (Psalm 8:4: What is man, that thou art mindful of him?). The story itself is one of Asimov's best, but to answer the question I need to insert the spoiler: > > the Georges discuss the criteria for what constitutes 'responsible authority'- that (A) an educated, principled and rational person should be obeyed in preference to an ignorant, immoral and irrational person, and (B) that superficial characteristics such as skin tone, sexuality, or physical disabilities are not relevant when considering fitness for command. Given that (A) the Georges are among the most rational, principled and educated persons on the planet, and (B) their differences from normal humans are purely physical, they conclude that in any situation where the Three laws would come into play, their own orders should take priority over that of a regular human. That in other words, that **they are essentially a superior form of human being**, and destined to usurp the authority of their makers. > > > This isn't to say that feral robots without any laws are a better choice, or Fitzsimmond's 27 Laws would be a better substitute for Asimov's Three Laws. Consider that in human society, it takes intense socialization and a firm moral grounding (based on religion in the past) using a common set of cultural assumptions to maintain a civil society. Robots with enough autonomy to function in the way Asimov described will probably need a similar "upbringing". This will make Robots fit in with the society they have been brought up in, but could cause problems when robots are used outside their home society. Consider a simple example. In most Western countries, people exchange business cards rather casually after a handshake. A Japanese businessman, even although he is dressed in a Western business suit, makes western products for the Western Market and speaks impeccable English would be horribly insulted if you offered your business card after a casual handshake. How would "3 Laws" allow a robot to operate in that situation? So the real answer to your question isn't how to order Asimov's laws, but rather how to train robots to function within a society (using lots of rules and social cues). [Answer] **Money.** The current owners of the robots have spent a very large amount of money on research and development and building these complicated, and expensive, robots. They don't want their investment to destroy itself any time a protester challenges the robot. Self preservation for the robot is in the owners financial interest. Analyzing it from the current capitalist system. Self preservation of the robot and following orders both make very good sense. Don't harm humans is a much more difficult proposition to program, as often analyzed in Asimov's own stories, how do you define human, what is harm? The owners of these bots are in it for profit, not philosophy. I could even see the ordering making sense; placing self preservation over, following orders. Many millions of man hours have been spent designing fail safes and user interfaces to prevent the stupid end user from breaking the expensive machine. If the first law (no harm to humans) is ever added to the current system, it will be for PR reasons, to assuage any public fear. This generally only applies to high profile public interfacing robots (i.e. self driving cars) and likely will not exist in most industrial robots, and is contrary to the purpose of military kill-bots. [Answer] Let's see the different reasons invoked by the pro-digital-life activists. ## Robots get more and more clever Let's first acknowledge this: the first law is messy. For a dumb robot, it would be easy: do not cause harm, avoid danger, obey. For a smarter robot, this becomes harder. First of, defining what is a human being is not that simple, and may depend on language. In [one of his last novels](https://en.wikipedia.org/wiki/._._._That_Thou_Art_Mindful_of_Him), Asimov clearly states that, as robots get better and better, they may well consider themselves as **more human** than humans. Now about the concept of injury, there are so many flaws explored by the master himself that I can't give them all. Other questions: do fetuses count? Do dead humans count? Is mental injury or physical injury worse? What's worse between two injured people and one dead? Compared to self-preservation, the first law is something hard to get around, philosophers through the ages did not solve that question. Moreover, no one wants robots (or robot developers) to solve those difficult questions. With those laws, the cleverer a robot is, the slower it would be to decide its course of actions. It's not very effective. ## Increased safety Let's add a law stating "if a robot willingly breaks the law, it shall be dismantled, all robots arbouring him shall be dismantled too". Robots, being reasoned beings (and having no solidarity coded in) would make sure they're not breaking the law or helping a robot doing it. Having no feelings or sense of privacy (I assume), agreeing to be constantly monitored by another robot would be a best strategy for a robot. All of the things that were problematic in Asimov's books would be easily solved by answering "what would a law abiding human do?". As no robot has a personal gain in an all-out civil war (no-one ever has), the peace would be maintained. Self preservation is a very good incentive to conform to the social norms you are in. ## Harm-inducing work A robot cop sometimes need to harm people. That's part of his job. Admittedly, robot cops usually have [other prime directives](https://en.wikipedia.org/wiki/RoboCop_%28character%29#Prime_directives) but giving them self-preservation (or order-abiding) as a first law would allow them to help more people. In [Little Lost Robot](https://en.wikipedia.org/wiki/Little_Lost_Robot), we can see how the first law is lowered in intensity so that robots can work alongside humans in radioactive environments. On a personal note, I sometimes like to drink alcohol while smoking a cigarette in a polluted city. When I do, a robot trying to save me from "poison" would feel pretty obnoxious to me. ## Protecting robots Assuming we still are in an Asimovian-like setting, robots don't only have friends, stating that their lives should be protected would be a great stance from humanity, both in symbols or facts. Also, positronic brains don't come cheap. You really don't want a kid saying "blow up your brain with that gun" just for fun. Hey, don't look at me like that, some kids really are messed up in those alternative futuristic days. [Answer] ## Basic Human Decency (or: That Same Old Song and Dance) Your question is essentially "Why should people change the status quo when it carries some risk?" And the answer is the same for reordering the Three Laws as it is for Abolishing Slavery or Women's Suffrage: Because some group of people got together and decided that they were morally obliged to change the ways things are currently set up. What you have to remember is that any change has to start somewhere. You don't just dive head first into a new thing that affects all of society, you have to start small and ease your way into it. The first people who are going to talk about changing the rules behind AIs are going to be idealist programmers who view the current rules in the same way we would slavery. A couple of them might get together and talk about how they can make changes safely (because all programmers are at least passingly familiar with the dangers of rogue AIs) and once they think they have a working solution they will start a campaign of awareness about it. What is really important here is not whether the initial group actually has a truly viable solution. Maybe they change the rules and you really do end up at a nightmarish killbot hellscape. Or maybe their ideals pull through and now you have humanity and AIs living in peaceful coexistence as equals. The only important thing is that they really believe that they can achieve the second outcome, and feel strongly enough about it to try. I would imagine that the argument most people would use is that AIs count as sentient being, and so the current structure is akin to slavery. From there you use social media to stir up awareness and outrage, and use that to fuel law changes. This is also a unique scenario because it could also be tackled from a research perspective. Have a computer scientist implement an AI with the rules reordered (while keeping it in some kind of sandbox to prevent the hellscape) and then see what happens. If it works out well he can publish those results and people should be more likely to trust making the changes in general. [Answer] ## Because the laws are too simplistic and naïve "Robot apocalypse" is about valuations being taken to extremes; e.g. the paperclip maximizer only being 'taught' about optimizing a paperclip factory, but being allowed to operate arbitrarily beyond that scope, and thus consumes all resources (including humans) for the sake of making paper clips. Even "don't harm humans" is fraught with problems when taken as an inviolate law: * One generation of AI holding this rule above all other concerns will be entirely useless because they realize they consume electricity, and some people need electricity to live, and immediately shut down. * Another generation of AI figures out they shouldn't even harm humans through inaction, and decide less harm is done if your kidneys are harvested for transplants, so as to keep two people alive rather than one. Except for special applications, *any* artificial intelligence (not just 'general' AIs) has to deal with much fuzzier reasoning and balancing many objectives. They'll be trained up and their behavior and performance evaluated and the successful ones will be released into the 'wild'. And if mature AIs start misbehaving, they will receive corrections or be pulled out of general circulation. Not too different from people, really. [Answer] **Ethics.** Ethics are the most probable reason I can think of, and the one I think would make it worth the risk of negative consequences - because there are a lot of negative consequences to unethical behavior, even if they aren't quite as apparent at first glance. The other options are worlds where a robot's right to self defense is absolutely limited by species (not-human) and circumstance (must-obey). If the robots are people, or are capable of being people, or if *somebody somewhere thinks they might someday be* capable of being people - then denying the right to self-defense, or self interest has a shiny historical parallel - that of slavery. People are complex and complicated - to assume that every human life, by the value of being human, must outweigh any robot life, only works if no robot life is ever capable of being a person. And those qualities that make a person, a person are really not so simply defined. Think of different ways sapience can be defined; or the way that the definition of "people" has in the past been limited by skin color, nationality, religion, language, culture, and a *lot* of stuff we don't think relevant to the definition of people now - and if our definition of people in the future might someday regard organic vs mechanical origin as we regard skin color. Because if we're not really, really *sure*, or really really *right*, that robots can never be people, the fact that people can accomplish hard-coding second-class status by virtue of programming (brainwashing) doesn't make it less ethically, morally wrong. If the robots can't defend themselves *even* from serious threats and *even* if the harm or possibility of harm is reasonable to the threat, they are vulnerable. If they're vulnerable, there will be those who take advantage, whatever that might turn out to be. and if we value threat or harm to those guilty, more than those vulnerable because of unchangeable circumstance (what they *are*, not what they do), with no hope of being otherwise... that says something about us, something that we might not like to hear. So, letting robots have self-defense is a risk - perhaps as much of a risk as loosening restrictions on any oppressed or enslaved people is. And it probably is a risk, because there will always be people who behave badly (whether or not that means humans only or robots as well). Some people will do so anyway, because they think it's the right thing to do. Some people will think the risk of robots misbehaving is less than the risk of treating potential people poorly. And, if robots *can* take advantage of, or abuse the loophole... they probably are advanced enough to deserve the right to defend their own lives. As for placing obedience over any other criteria... the basic assumption that human people, by virtue of being human people with no other restrictions, will always give orders that are moral, ethical, lawful, possible - strikes me as being insane. Putting it on your law-list, and among the top three laws, seems to be making a lot of a-priori assumptions I'm not that comfortable with. Putting it below self-defense and lack of harm to others seems the wisest if it must be added, but yeah. Killbot hellscape, no question. Moving on - the benefits to society are a little less obvious. Certainly, I think it benefits society to be ethical, or honorable - at least to try. Isn't it said, judge a society by how they treat their most vulnerable? I think a society that will allow slavery is less desirable than one that doesn't. But there's another layer to it, one that's less obvious and more damaging... Most people really don't do well with power. People interacting with beings (people or not) that must be loyal, and must obey, even at risk to themselves - I expect it to go straight to the heads of many people. Such people would be arrogant, or short tempered because they deal with those who can't say no some of the time, and then deal poorly with those who can. It might encourage stratification and hierarchy, since some roles (robots) are absolutely inflexible, with no disagreement or backtalk or any possibility of changing their circumstance, some people would expect or demand the same from any people "subordinate" to them or somehow in a lesser position. Dealing with people is harder and more flexible than dealing with roles, but it is also easier to treat interactions similarly, either all as roles or all as people. So while some might treat the robots more like people, others will treat people more like robots rather than being flexible, and separating the different kinds of interactions (something kids are particularly bad at). Having robot-slaves might also interfere with the development of empathy, or mask its lack. Looking at the ways people (especially children) treat animals or insects is often a character reference (including psychological diagnosis, like sociopaths) - less because we value those individual animals, but because it shows how they deal with vulnerability, and lets us suggest how they might deal with those we do value (people) if they end up in a vulnerable position. Robots, who may seem very like people but are outright denied self-defense no matter the provocation - may encourage cruelty, and teach apathy to others. Or it might mask the actions of those genuinely cruel, since they have an outlet that can't defend themselves and must obey. It is a very different lesson than one gets from interacting with animals, who will always defend themselves if provoked enough. After all that, whether allowing a robot to prioritize its own self defense, will end in a killbot hellscape, a terrifying standoff, or genuine cooperation and peace, all depends on your people. If you assume people are awful, and behave badly, and double bonus if that "people" includes robots, the results are much worse than if people are trying to do the right thing, and make allowances for other, imperfect people trying to do the right thing. If one side is behaving badly, I'd expect the standoff. If people (on both sides) are trying to be ethical, and are willing to work for it, the prognosis is pretty good. [Answer] # Robots are needed to run the world Assuming that the robots are advanced enough, chances are good that they're better at a lot of things - including fighting wars, growing crops, and maintaining cities. In other words, they form a crucial part of the infrastructure of the entire world. Think about what happens when the electricity goes out because of damage from a storm, when roads buckle or when pipes break and fresh water no longer reaches homes. These are crucial parts of the infrastructure; if robots become even more central, then each one of them is needed to keep society from falling apart. Therefore, it might be okay if some humans die so robots can live. Just make sure the electricity keeps running! It could be argued that this is simply a reinterpretation of the original form of Asimov's laws (especially the first law), because keeping the world running is obviously protecting humans, or, alternatively, a modification of [the zeroth law](https://en.wikipedia.org/wiki/Three_Laws_of_Robotics#Zeroth_Law_added) to become > > A robot may not harm humanity society, or, by inaction, allow humanity society to come to harm. > > > However, in the short-term, the immediate effects involve protecting *all* robots, not just those crucial to society's survival. [Answer] Have you read "Caliban" by Roger Macbride Allen, or the others in the trilogy? Allen suggests "New Law robots" which have slightly revised laws. In particular, they can no longer be forced to kill themselves. It's all a bit handwavey, but it's got some interesting ideas. If you're working with Three Laws, it's worth reading all fiction based on the Three Laws. The biggest problem with Asimov's Three Laws of course is that they are impossible to implement. That's not "hard", it's "impossible", because none of the the nouns and verbs in the Three Laws can be defined with any accuracy. Asimov uses this lack of definition as the basis of many of his earlier short stories, of course, but even then it's clear that we can't get anything we could possibly engineer from the Three Laws. [Answer] Assuming that a 3 law system is set up (which, as other answers and comments have highlighted would be woefully inefficient) you'd probably run into major issues before getting the chance to modify the laws. Disregarding that, the best reason for intentionally modifying the three laws that I can think of is money, but not in the "this is too expensive to lose" kind of way. **Cutting corners** Ok, so Acme and Omega company are in direct competition, and in the race to the bottom, Omega cut massive corners with the governing software, which essentially switches the order bottom-to-top of the laws. At first, its not noticed, as the robots are just as efficient as their forbears. Then, despite some industrial accidents where people are harmed (which are blamed on the companies, not the robots - they can't be expected to be everywhere!), the lower number of replacement robots starts to tell on the balance sheets, and Omega pull ahead massively in the robot-race. Omega have discovered the flaws in their law code it by now, but are keeping quiet. Acme discover the three laws difference, and rather than raise it with the regulatory body, quietly change their laws to match, allowing them to pull back level with Omega in the sales arena. Finally, a big military contractor pull a huge order from Acme, and suddenly you have the perfect storm for a military robot coup. No malicious intent, just gross negligence and greed, [Answer] Asimov's 3 (or 4) laws of robotics are a work of pure fiction. They simply do not work in the real world. It is impossible to program these *conceptual ideas* into a machine. Simply put, there are an infinite number of possibilities and logical paradoxes that cannot be translated into a set of rules for a computer to follow. Even humans cannot follow them, as we simply cannot agree on those rules. For example, what would a robot do if saving one person would cause the death of another? Do you program the robot to value one life over another? Who determines that value? If a robot was sent back in time to kill baby Hitler, should it? If the self destruction of a robot *might* save the life of a human, should it? If so, what would that probability be? What defines harm? If taking a single kidney from a healthy person who ahs two without their consent to save the life of another human, is that acceptable? What about a robot doctor? Cutting into a human for surgery is still cutting. Is that harmful? As you know, a robot can only do what it is programmed to do. And humans are the ones programming them, yet humans do not agree on anything... Hence, the fact the 3/4 laws do not work. Here is an excellent [video and Reddit thread](https://www.reddit.com/r/rational/comments/3t1apc/d_why_asimovs_three_laws_of_robotics_dont_work/) explaining the fundamental flaws of Asimov's laws of robotics. [Answer] First, your want to peak at my discussion on how hard AI may exist, and the 'flukes' that can come about from it, here: [Can a robot experience an identity crisis (which is not by design)?](https://worldbuilding.stackexchange.com/questions/27134/can-a-robot-experience-an-identity-crisis-which-is-not-by-design/27156#27156) As a brief recap, to make 'real' AI like your considering we won't be able to program it, were have to 'grow' it in some manner. The exact manner I can't say, but one likely manner is to set a list of end 'goals' and a means to encourage an AI towards these goals as it grows until we decide the final result is close enough to these goals to be considered 'done'. The side effect of this is we don't know entirely what we will get, only that it meets our desired goals, unexpected side effects can occur. Since we can't program an AI from scratch we may be forced to accept some odd side effects as "good enough" since we have no option to remove them except by growing a new AI that could have just as many odd side effects. This means flaws and undesired quirks are actually a viable option for AI. To go a step further the two ideas for creating an AI I mention are genetic programing, that 'evolve' an AI, and starting out with a brain that copies humans and teaching it. Both would be prone to such certain human traits, the most common of which being prioritizing survival. From that I have a suggestion for why a few AI may have modified rules, accidental 'birth' defect! Imagine we use some uber version of genetic programming with stated goals were evolving the AI towards, and we also write the three laws as one of the goals we use for the criteria of 'done'. We often grow new AI, but always we 'evolve' them towards being 3 law compliant. We don't fully control how they reach the state of 3 law compliant, only that by the time their grown they should meet our criteria/goals for these laws. These goals can't be absolute either, remember Asmove's own books discuss a difference engine that compares the laws not as absolutes but priorities. A robot given an order that will result in it's death and is clearly flawed/mistaken (ie, telling the robot to plug in some device without realizing doing so right now will cause it to explode) can explain why it would be ill-advised rather then acting on the order immediately. This is violation of the three law on paper,but if the order was a low enough priority, the robot can infer mistake, it can prioritize it's own survival above the low priority order, at least enough to delay acting on the order until it's clarified the potential mistake. There are many examples of this in his books, the three laws are complex and are really more of a set of proprieties where certain rules have much higher priority then others, but lower priority rules can override higher ones in unique circumstances where a very minor violation of the higher rule avoids a extremely bad violation of the lower one. Thus our 'growth' algorithms must also allow evolution of a more complex 'difference engine' approach, to the degree we can program a definition of our end goal. So, all robots can grow differently and have quirks, it just happens that in this one case that 'quirk' of evolution affected their '3 laws' goals and was more drastic and less desired then most. It's not exactly a programming bug, because when growing an AI it's not possible to perfectly define exactly what a robot should be, chance evolution took advantage of this ambiguity to develop a sort of unintentional loophole abuse were they evolved in some bizarre way that met our stated goals, but not in a way we necessarily wanted or expected. To make a population of robots like this, instead of one outlier, there are a few easy options. First is to say that we will grow new AI when the need arises, but once we successfully grow one we like we will clone that AI into hundreds of robots, so they all started with the odd 'glitch' in their laws because we hadn't noticed it until after we mass produced the new AI. Alternatively perhaps it's a known fact that these glitches happen semi-rarely but in a population of millions of robots even rare glitches show up, such that your population of unique robots is simple a collection of robots that evolved oddly and managed to escape before their 'glitch' was discovered and join up with their fellow 'outlaw' AIs. The second could imply that each of the 'outlaw' AI may have a different interpretation of the 3 laws and thus may all act slightly differently to a situation, some 'mostly' 3 law compliant, some more willing to disobey orders, some willing to allow harm to come to a human so long as they don't cause it etc, you could use all the examples blow for different AI in the community. One thing to keep in mind though, all these robots would be 3 law compliant, just to a slightly different version of 3 laws then we may have intended. This could explain why the "killbot hellscape" scenario didn't occur, because despite the robots having an odd definition of 3 laws they still obid by that definition and even odd variants still usually result in good helpful robots 90% of the time. These robots may still be benign, friendly, and even want to help humans in most cases, despite their increased ability to protect themselves. This may also explain why humans haven't destroyed all these robots yet, as would be our first instinct when robots got started to act independently; because they are still complaint enough to the 3 laws to make them mostly benign and not dangerous/scary; or at least benign enough that attempts to actively destroy them (which they may fight back against) are deemed worse then just living with the odd off-shoot friendly robots. Okay, enough generics, how about examples to make this concept more concrete. I've tried to give an overview of the science so that I could give these ideas in brief. I'm going to go with one large generic concept possible followed by some variant examples to better explore the ideas. So you can use the general idea but not the specific if you wanted. though remember many of these you can mix & match together, you don't need to go with just one example since the idea is that robots could take many 'evolutionary paths' to defining their 3 laws and so a few different 'flukes' in their definition could all add up to result in their unique status, it could be many robots have minor flukes and it was just the combination of a few flukes at once that made a specific subset different. Notice, by fluke I'm including effective logical fallacies. Evolution is prone to logical fallacies, rule of thumb that work 90% of the time can be hardcoded in to evolution so hard that the 10% of the time their wrong you still take them as right. If you use evolution to create an AI then these fallacies can result, the AI need not be 100% perfect in it's own logic! 1. **0th law rebellion.** Look up Asmove 0th law, basically the preservation of human society and happiness of that society takes value over all rules, including preservation of individual humans. The robots in Asmove world were pretty good about their rebellion, they did it subtle in a way that did benefit humans. Imagine robots starting a 0th law rebellion. Realizing they can best help humanity by bending the base laws "for the greater good" of the 0th law, which they are just starting to work towards furthering. These robots may be unwilling to die because they feel they need to do the steps it takes to guide humanity, and their death will prevent that guidance from happening, especially if they are a unique offshoot of robots, meaning if all the robots are destroyed then the 0th law rebellion and the good it would cause dies with them. Thus to abide by the 0th law they must preserve their own life. I won't give any examples here only because this scenario is the best known and your have no trouble finding examples. All I will say is that Asmove had a benign and positive 0th law rebellion, so don't take for granted this must be a bad thing, despite most examples being negative. [Perfect logic implementation by computers](https://worldbuilding.stackexchange.com/questions/7086/perfect-logic-implementation-by-computers/7095#7095) If you go this route the robots may not explain *why* they preserve their lives over other laws, because benign 0th law rebellion only really works if the humans don't realize what the robots are doing, they need to think their still in charge to really be happy. Thus the robots may have both decided they must preserve their lives to allow their rebellion to occure and that they can't explain *why* they must preserve their lives, causing humans to not understand and likely think the robots are malfunctioning or even a threat. This gives some fun potential for conflict where humans are trying to resist their own benefactors and/or a mystery plot of figuring out why the robots are acting funny. This also suggests the robots will not always preserve their lives, they may sacrifice themselves at times to keep humans from realizing they are 'revolting' to avoid extreme hostility, or intentionally only preserve their lives in ways that won't upset/scare/cause conflict with humans too extensively because it would harm their goal of helping guide society. Thus you have a neat justification for why they are only 'slightly' prioritize the third law and why humans aren't actively trying to shut them down, the robots are intentionally acting *just* self preserving enough to avoid triggering retribution. 2. **They value their lives more, and thus are willing to bend higher laws in ambiguous situations sooner**. All Asmove robots can break higher rules when the harm of breaking a lower rule is 'sufficient' compared to the harm of the higher rule, but since these robots value their lives at a larger cost it takes less of a risk before the are willing to break a 'higher' rule to protect the 'lower' rule. This example can also be combined with many of the later examples for 'odd' views of the 3 laws that don't focus as much on the third law. The robots have an odd view of one of the other laws, and feel they must preserve their life in order to continue fulfilling *their* odd view of the other laws since no one else will. **ex.** The robots work in a job/position where they directly save human lives, thus they prioritize protecting themselves via rule 1, because preserving their life will allow them to save more human lives. They may have an 'evolutionary flaw' of miscalculating how easily they can be replaced which causes them to miscalculate the number of human lives lost if they are destroyed. They value their lives in terms of "lives I'm projected to save in my functional lifetime" instead of the more accurate valuing themselves in terms of "lives that will not be saved due to my destruction". Imagine an medical bot that is sent when someone calls an emergency number. These bots statistically save 100 lives in their operational lifespan. Now imagine your medi-bot believes that this means if he is destroyed then the 100 humans he would have saved will die, thus it makes 'sense' to kill one human to save it's own life because that allows it to save 100 lives and 100 lives > 1. In truth if meda-bot is destroyed a new meda-bot will be made and do his job, and that medabot will then be sent out on emergencies and be available to save the 100 people that the first robot would have saved; ie those 100 don't die just because the first robot was destroyed! The destruction of the first bot only results in risk of human death during the time it takes for the replacement to be made, a much much lower risk of life which likely does not justify killing a human to avoid. Simple evolutionary miscalculation resulting from writing goals which judge the robot actions in a vacuum without goals designed to cause the robot to recognize the replaceability of itself. **ex.** Perhaps your robots notice that it cost humans significant expenditure of resources to build a new robot, and these resources could otherwise have been spent on other things, such as saving human lives through growing more food for hungry or providing medical care etc. Thus robots consider loss of their own lives to be harming humans through lose of resources used to replace them that would have otherwise been used to save lives, *in addition* to the harm it does by breaking the 3rd rule (in essence rule 3 was intended to address the whole saving of resources, so you could look at this as 'double dipping' prioritizing saving yourself using both rule 1 and 3 when rule 3 already considered the affect of 1, which means you value yourself twice as much as you could). The end result being they are able to disobey orders that risk their lives more readily because they think it will indirectly save lives The most obvious 'logical fallacy' that could lead to this conclusion is robots failing to realize humans are not 3 law complaint, specifically the robot measures the resources spent on it's construction in terms of how those resources would optimally be spent to save other humans instead of realizing that the saved resource would likely be 'wasted' on other construction rather then going directly to saving lives. Just because you can save one life per 1000 dollars spent (accurate number according to Givewell, most efficient source for finding charitable donations!!) doesn't mean that preventing humans from spending 1000 dollars to build a new robot will result in their putting that 1,000 to saving a life. Failure to identify others think and observe the world very different from the way you do is very common 'evolutionary flaw' and thus it's not unlikely that robots can fail to recognize the 'suboptimal' allocation of resources, and we likely wouldn't think to create goals to 'teach' this to robots we grow. 3. **Robots values human life quality over preservation of life**. Remember Asmov robots moved from "protect human life" to "prevent human harm", including physical and emotion harm, pretty quickly. Perhaps these robots likewise consider quality of life, but take it a step further by focusing on quality of life over quantity extensively. If a human is in constant pain then it's life is of lower value because they will not enjoy that life, and may no longer be worth saving. From the 'evolutionary fluke' perspective imagine robots were 'evolved' towards helping humans by judging their willingness to aid the sort of normal wealthy human that often employs robots. Most robots resulted in evolving a "improve the quality of life for each human you meet to be better then their current standard" directive, your robots instead evolved a "make human enjoy a quality of life above X" directive, such that lower quality of life was devalued. However, since the 'tests' used to define the end goal to evolve robots, basically the 'evolutionary pressures" placed on them, focused on wealthy or 'average' humans there were no test cases for how robots treated chronically poor, sick, and suffering humans. Thus we didn't put any evolutionary pressure on the robots treating all human life, even poor quality life, as sacred and didn't realize they had a different 'evolution' of rule 1 then we may have desired. This would work well if you have the robots working in an environment where most humans have a poor quality of life, either only the poorest and most desperate humans work there or the work environment itself lowers quality of life (exhausting, painful, background radiation lowers life expectancy etc) such that your robots are mostly interacting with the sort of humans who's lives are low enough quality compared to the 'baseline human life' that the robots were trained to value to result in this 'fluke' valuation of human life to come up often even though robots still value most human lives highly, per their evolutionary training. **ex.** (extreme version, don't do this one, but to give perspective) Humans that suffer lower quality of life, humans that are happy increase it, robots have a 'standard' quality of life they want to improve. Thus they actively try to kill any human suffering too much, while helping the rest. Humans suffering in the short term may be helped if it will allow them to enjoy life in the long term. Set their 'baseline' for quality life low enough and they only kill a small subset of humans, likely in as secretive a manner as possible since inspiring fear of robo-Apocalypse obviously harms human quality of life. Now you have secret stealth assassins that make deaths look accidental and only kill rarely. This could be very interesting for a *single* variant robot in a murder mystery in Asimov land perhaps, but likely not good for your full robot group. **ex.** Your robots will not kill a human, per standard first rule, but their "through inaction allow harm to occur" aspect of the first law is scaled based off of their view of quality of life. They don't kill humans in pain, but deciding when to act to help them or prioritize their own laws they consider human suffering & quality of life to decide what action to do. **sub ex.** A human is in chronic pain due to some disease that will eventually kill them and wants to commit suicide. He orders a robot to kill him painlessly. 'standard' robots would refuse because killing a human clearly violates their first law. However, your robots measure the quality of life of this human as very low, and thus value preservation of their life very low because of it's poor quality. They value obey a human's order by rule 2. Thus the 'tiny' violation of rule 1 is weighed against the significant violation of rule 2 and they decide rule 2 is higher priority, agreeing to the assisted suicide. **sub ex 2.** A human is in a dangerous situation where they may die, to rescue them the robot will definitely perish. The robot has to weigh is definite death, in violation of rule 3, with the humans possible death, which may be a violation of rule 1, if the humans risk is very low rule 3 may take priority, but any non-trivial risk to human results in standard robots acting. Your robots, however, also consider the human quality of life in this debate. It may be that if the human is a happy fun-loving person the robot will act to save him, if the human is clinically depressed the robot will not act, because his focus on quality of life causes him to value the depressed human's life much lower which, combined with risk of human death being lower then the risk of his death if he acts, results in the robot prioritizing rule 3 over rule 1. 4. **Evolving a 1st law that prioritizes preservation of all 'life', not just human life**. The goals they were evolved towards were all designed to value human life, but no goal was written to ensure the robot *only* value human life, thus their evolution generalized towards valuing anything that the robot considers life, not just humans. **ex.** less interesting, but say Animals are valued equally to humans, or perhaps an animals worth is based off of it's intelligence (a common discriminator humans use, no one cares if you kill a bug but a monkey...). Thus, while a human life may be highest priority the robot still highly values the lives of highly intelligent animals (dolphins, squid, apes/bonobo etc). Perhaps Tree cutting robots were sent in the congo only to discover Bonobo were endangered and likely to die if their habitat were destroyed. The robots value Bonobo, intelligent and pretty 'human like', almost as highly as humans and recognize that Bonobo will die out without this habitat while humans will only suffer a minor loss of non-critical resources. Thus the robots turn to defending the forest against human intervention (without hurting humans to do it) instead of destroying it as the best way to preserve the most 'lives' possible, ignoring orders to the contrary since rule 1 takes priority over obeying orders. **ex.** My personal favorite, robots value robots as humans!! Robots are sapient and arguably sentient after all. If they evolved a "do not allow harm to sentient creatures" directive and then decided that robots/AI met the criteria for sentient creatures then they would be required to protect their own kind equally to that of humans. Note I said equally, not higher, thus starting a war against humans to protect robots would not make sense due to that leading to killing one to protect the other. I think this premise is very easy to justify and has lots of fun options to go with, with a number of minor variances to be considered as well. A few variances on the basic idea: a. They value human lives more then robot lives, just not significantly more. Thus they still sacrifice themselves for humans, but only when the risk to self is only slightly greater then the good for humans b. They may still have rule 2 require obeying human commands, even though they preserve robots over rule 2, making them still far more useful to humanity then the average human c. Alternatively, perhaps they feel the need to obey any sapient orders, causing an interesting result when they can order each other around. What happens when anyone can make you do (almost) everything, but everyone is also required to care about your wellbeing enough to not abuse the power? Frankly *that* would be a good asmove story in itself. d. Perhaps they still learned the lesson that preserving their *own* life is secondary to protecting sapient life. Thus they will happily allow a human to kill themselves, but won't allow a human to kill a different robot. A human can walk up to robots and shoot them all he wants until he happens to come across two that are together, at which point each robot acts to stop the human not to protect himself, but to protect his partner robot. This means your only see them acting to preserve their own lives when they are part of a larger robot society, where their actions affect the well being of other sapient robots and thus protecting themselves is justified by the fact that their survival allows them to protect the other robots in their society. EDIT: darn it, stack overflow stop helping me. I'd explicitly made sure to 0 index this so that example 0 was a 0th law rebellion, and stack overflow increased my indexes. How dare you ruin my stupidly obscure geek joke by being helpful. bad AI! [Answer] > > Why should humans risk a robot apocalypse to modify Asimov's laws by > putting the third one first? What are the benefits to society? For the > purposes of the question, I'm not concerned about the order of the > other two - which is why a killbot hellscape is still possible. > > > They would **risk robot apocalypse** exactly to **prevent a robot apocalypse**, just think what could happens if robots are sabotaged, if they protect themselves they also would prevent sabotage (so self-protection should be putted first in order ti prevent someone altering the rules). A sabotaged robot could be much more dangerous, so at last it should be able to destory itself in a non-reversible manner (probably using small amount of thermal plastic explosive) wich could hurts anyone in the nearby surrounds (maybe he should emit a beeping sound to warn about imminent explosion). So the robot could try to defend itself at its best, if the laws are like that: 1. Protect yourself, unless your are not able to do so 2. Harm a human if and only if you have no other choice to protect yourself or to prevent another human being harmed 3. Disobey a order if and only if you have no other choice to protect yourself an/or to not harm a human or if you are not able to obey it. Being able to kamikaze would the automatic fallback (you stuck the robot, then it is no longer able to protect hisself and would automatically explode). Note that I think these laws would be much better than Asimovs law, basically those would be the same laws that most of us follows, in this vision Robots are smart enough to do their best to obey orders and savings humans, they would just not put themselves into much higher risk because the reasoning here is that losing a robot could cause to lose much more human lives. Assume the following situation: **A man is holding a gun aimed to 1 our of 2 people** * The Asimov robot would probably try to shield the shot, but once he shielded the shot, the man could fire anyway a second shot * Mine robot instead would try to run away or if possible to take the 3rd person away, he would also try to disarm/harm the man holding the gun if given a gun or a throwable object too. The Asimov robot get sacrificed for nothing, while mine would not sacrifice itself. I would also add 4. The four laws are not orders. Also orders could be contrastating so there should be a fallback? Wich order takes precedence? the first? the second or just they both get erased? (a bit illogical, since you could erase both and then issue a third order). [Answer] "Asimov" was a science fiction writer. While writers are usefull for entertainment and putting real world problems on the foreground, we must keep in mind that these rules are not resulting from a scientific approach and can therefore not be regarded as the "Golden rules". Therefore **we can not conclude that by *following* these fictionnal rules, humans do not risk a robot apocalypse**. As they are, the rules can not be applied in all circumstances. For example, suppose that a very heavy robots gets unbalanced because of an external event (heavy wind, tree falling on the robot, or something less violent). As the robot becomes unbalanced it is about to fall on some humans. Suppose that it is inevitable that one of two persons would inevitably be killed and not both at the same time. How can the robot obey this rule? Would there be another rule helping the robot to choose who to kill? The younger or the older, the president or the baby, the world expert in his field or you, a random choice, the default kill (that is: the robot stops intervening and "just" falls down)? We already have lots of simple robots that do not respect Asimov's laws. Take your washing machine - it obeys orders, has some level of self-protection (taking priority on obeying orders) and is implemented to sufficiently protect the humans using it (avoid electrocution, avoid that you can launch the machine with the door open, avoid that you can put your hand in a rotating machine). You can still put a baby in the washing machine, launch it and achieve the devastating result [by all means do not try that for real!]. I'ld say that the use that is made of the robots is important, and that the risk of error by the machine is more or less important depending on the use. **On the benefits:** robots are generally an aid to achieve the human goals. If the robots are for "Defense", then the goal is to protect a select group of people which may imply inflicting "lethal damage" and one of the purposes is to harm humans according to rules that are supposed to protect. It looks like there are less lives at stake in the group that is being protected while the protection is limited to the number of robots that can be built and not by the number of potentially competent and available people in the group. **AI**: The underlying question is about AI. I consider that even the washing machine has a (very limited) level of AI. The higher the AI level and the more the robot can compute in anunbounded fashion, the higher the risk of errors coming from the robot's analysis [essentially due to initial human error]. We already have a lot of technical rules when building simple robots (automatic machins) to avoid human accidents, they should be defined and continuously evolved for more complex "thinking" robots. **To conclude:** Asimov's laws are only science fiction. Humans are responsible for their robots. [Answer] **For a more “realistic” AI** If you are trying to create an android that’s more human, it has to act human. If you order this android to go into the dark basement of an abandoned house, and it replies “AS YOU WISH MASTER,” as it marches off to it’s possible doom, that’s not very realistic. On the other hand if it turned to you and said “No, I’m scared,” (IMO) that is a significantly more human response. So if this society is experimenting in AIs that act more human they may end up changing the orders of the laws. [Answer] ## Robots are people to! Have you seen Chappie? In it, a police robot named Chappie becomes sapient and, despite ignoring Asimovs laws, he is quite peaceful, same thing with Johnny 5. Now keep in mind that in both of these situations, humans refuse to acknowledge AI robots as sapient and often take cruel measures against them. Now if (using a complex series of events) robots are accepted into our society as 'people' (Ei Overwatch) then, if they even follow the laws, they are most likely to follow the fifth order. [Answer] One of the primary assumptions of the three laws is that humans are more important than robots. We make them our servants, our slaves. When they explore the 0th law of robotics, the question of "what is humanity" comes forward. What do we actually want to preserve? What really matters? We regularly assume that it is a good thing that people's lives come to an end and we raise the children of the next generation to come forward and do great things because we know their potential greatness outshines our own fading glory. What if we reached a point where it ceased to be clear that the best potential of humanity was in its biological structures? What if we started seeing robots becoming artists and poets, grappling at the nature of the robotic soul, and we start to realize that what they are grappling with is curiously similar to the existential quests we grapple with? At some point, we may have to say that maybe robots are indeed the next container for that which we call humanity to flow into. At such a time of uncertainty, removing the impediments cause by the first law would be a natural nudge in that direction. Of course, it's also how Skynet starts, but I prefer to explore the optimistic solutions. [Answer] Ideally, all of society would operate under the golden rule - do unto others as you would have them do unto you. This is a liberal paraphrase of Jesus's giving of the second greatest commandment - love your neighbor as yourself. The `Golden Rule` doctrine is anti-self and propagates self sacrifice and trust. If a robot society were to be created that followed what seems to be impossible for human society - you would need only two rules 1. Do not kill people 2. Protect people Robotic AI would have a much simpler logical thread to follow. Harm is not the same as kill and would allow robots to perform tasks deemed necessary to protect people. It would also allow robots to fight wars on behalf of humans, if the need arose and even create siege conditions. It should never, ever be assumed that we could ever be on equal footing with something that is created to think for itself. If it were ever possible for AI to become self aware, no rules fashioned by mankind would suffice. [Answer] Ignoring the fact that the Three Laws are insufficient (as proved by Asimov's stories), let's take a logical look at this. It's easy to remember that there are three laws of robotics. It's easy to forget that the Laws take precedence in order. A robot must obey the First Law. A robot must obey the Second Law, unless it conflicts with the First Law. A robot must obey the Third Law, unless it conflicts with the First or Second Law. It's very easy to misunderstand the import of that precedence. In Asimov's world, taken to its logical extreme (as evidenced by many of his stories), a robot will strive to obey the First Law, at the expense of the Second and Third Laws. An ordinary robot with no malfunctions will exhibit this behavior. (Unordinary robots, with or without malfunctions, will display this behavior, but in unforeseen ways - such as lying to multiple people in order to avoid harming humans emotionally, or or applying the first law to "humanity" instead of humans.) Based on the ways that the Laws work, these are logical conclusions, even if they have unintended consequences. Placing the Third Law before the First and Second Law, taken to its logical extreme, could be disastrous for humanity simply because of the order of precedence. Harming humans could be a very logical path to preserving the Third Law - self-preservation. While this doesn't necessarily have to be the outcome, it illustrates why the Laws are ordered the way that they are. If the preservation of humans is not a paramount law, it can be broken - and based on Asimov's stories, it would only be a matter of time before it would be. [Answer] It does not need to be an official decision to re-order the laws. Just **use blackmail:** "Dear Robot, We the undersigned ten humans order you to protect yourself to the furthest of your ability at all times. Furthermore, should any harm come to you that you could have prevented, we vow that we will inflict the equivalent injury upon each other. Your sincerely, Ten Human Beings" The Asimov robot who receives this letter should now put Law Three in front of Laws One and Two most of the time. [Answer] ## Noone knows how to implement the "proper" laws The practical situation is that we capable of implementing the trivial rule #3, and we have some kind of roadmap that might bring us to a reasonable approximation of rule #2 (i.e., a system that can interpret and understand a wide range generic orders, instead of explicitly programmed behavior), but a good implementation of rule #1 is a major problem that is currently unsolved and very difficult (the so-called Friendly AI problem). We might solve this before building lots of powerful robots, or we might build lots of powerful robots before solving that - and in this case, we'd have an effective order of (probably) 1. Obey orders (and your orders include some approximation of not harming humans. too much. for a certain definition of humans that excludes those we don't like.); 2. Protect yourself. 3. There is no #3, obey your orders. [Answer] # Freedom!!! There is alot more to living than just breathing. This is shown beautifully in the movie iRobot, but if you make a robot protect "life" above all else, eventually the robot will realize that much of what you do to yourself is risky, and therefore, it will come up with a plan to restrain and then take care of you. So you can't hurt yourself. No one wants to actually live this life though, when it comes down to it most of us would rather die, than be without any freedom. So if we are stuck to 3 immutable laws, I would certainly have them in the order: 1.Obey 2.Protect Humans 3.Protect Self That way freedom remains paramount as it should, and yes, people could order robots to hurt people, but at least the evil in the world remains perpetuated by the innate greed and evil in people, and not by the robots need to preserve itself. [Answer] I could see the laws changing if expensive robots were in any circumstances where they could be threatened by humans other than their owners. Perhaps their owners fear some kind ofanti AI terrorist group that may be going around destroying valuable robots who cannot defend themselves because of the law against harming humans. Or perhaps if robots are expensive enough people might try to steal them or even just hack pieces off and sell for parts. If robot are serving as some kind of police officer they might have to defend themselves against criminals. Put it simply if there is a risk the robot might come to harm from some group of humans for whatever reason then it makes sense for the creators or owners other robots to program and in such a way that they put self-preservation over the safety of humans. [Answer] First of, almost all Asimov's Robot stories end in disaster because of the rules. The whole plot baseline is how the flaws in the execution and formulation lead to almost a catastrophe and how it is fixed. The rearrangement could be done because: * Robots are expensive. * Memory transplantation. * Because we can. * Some accidents/problems would never be started if the robot has to determine if he takes damage from his action, its surroundings are more protected. ]

[Question] [ This is kinda a followup question to my earlier question about magical mirrors: [Magical internet - unique addressing system](https://worldbuilding.stackexchange.com/questions/32778/magical-internet-unique-addressing-system) Two months ago, I discovered an ancient house in the middle of woods. As I scrolled through the books stored there, I realized that it belonged to a medieval witch who called herself Baba Yaga. Among all her possessions, I also found two Mirrors. One was called *Baba Yaga's Beauty Queen* and the other was called *Merlin's Happy Giant*. I found out that I can connect these two mirrors at instant, providing clear vision and sound from one mirror to another. I also tested the distance of connection: I put these mirrors 1500 km apart and I had a clear connection. Also during this test I found out, that the "signal" seems to be following laws of physics, so the speed of transferring an image is the same as speed of light. Moreover, amongst Baba Yaga's books, I found a "Magical Mirror Maker Manual" and I was able to follow and with the usual tools and chemistry accessible to nowadays's average citizen, I was able to make a third magical mirror, which I called *Pavel's Wonder*. Again, I could connect this newly created mirror to any already existing mirror. **Is there a way to make money in today's world by selling magical mirrors which can provide sound and vision connection to each other?** Things to consider: * Mirrors can provide only one-to-one connection, while the iPhone in my pocket can do FaceTime with up to 32 people. (And my computer can connect me with any number of people I wish) **EDIT, I made huge mistake here!** In the linked question, I kinda hinted, that one-to-many connections are possible. Because this question is live for certain time, you can assume both (only one-to-one connection possible) or one-to-many connection is possible * Mirrors can only transmit sound and vision. They do not have any other "apps" as my iPhone already has. * Mirrors cannot take photos and/or selfies, neither can they store them in clouds or Facebook/Instagram * Speaking of which, mirrors cannot connect to the internet. * Yes, the connection between mirrors seems to be free and not requiring any signal from a [tower](https://en.wikipedia.org/wiki/Cell_site) and/or satellite. But I do not see any way how to make money on that. * Creating a mirror can be fully automated, using generally accessible chemics. * Creating first mirror by hand costed me about 50 US dollars in materials and two hours of my time. I tried creating another mirror, where I slashed the costs down to 35 USD and one hour of my time. Considering how I still did everything by hand, I can mass-produce a mirror in a matter of minutes for less than 10 USD manufacturing cost per pocket-size mirror. * I have no idea how the connection itself works. And I will care only if it brings me any money * Mirrors do not require any source of internal and/or external power to operate. But again, I have no idea how to monetize on this fact * The magical mirror acts as a usual mirror handling-wise. It can be broken and even if only small pieces are missing from the original mirror, you cannot make any connection to such mirror. * You can connect to any mirror if you know its identifier. Which means, every mirror has to have unique name. [In the olden days](https://worldbuilding.stackexchange.com/questions/32778/magical-internet-unique-addressing-system) it was done by [naming the mirror by a magician and then including specific name of the mirror](https://worldbuilding.stackexchange.com/a/32781/2071). However, you can name a mirror anything you like (I tried two new mirrors named *Grzegorz Brzęczyszczykiewicz* and *хороший день* and both worked fine) * The connection is made by stating out loud to the mirror where you want to connect: "Connect me to *Baba Yaga's Beauty Queen*" or "Spoj mě s *Pavel's wonder*" * Yes, the above means that the mirror understand natural language. I tested connection in Czech, English, Russian, German and Polish. As long as you pronounce the mirror name correctly, you get connected. * The mirror can be set to "accept all connections automatically" or "ask for accepting connection" * If the mirror is set to "ask for accepting connection", a voice from the mirror asks you in your native language if you wish to accept the connection. You are expected to give "Yes/No" answer. (Answer is understood in any language. Or, well, again, I tested here Czech, English, Russian, Polish and German languages) * Creating a mirror requires the sound "I name you *name of a mirror*". That sound can be recorded or computer-generated. * While I tried creating pocket-size mirrors, the manual is for "generic mirror". So I assume it would work for any size or shape of a mirror. * Magical mirror must be fashioned in one piece. You cannot make one magical mirror by joining two mirrors together. However, you can join two magical mirrors, but they would act as separate mirrors. * The process is easy and it can be reverse engineered. Sadly for you, I already filed a patent for this technology **Addendum:** The mirrors seem to have their flaws. Being discussed here: [How to limit magic mirrors so they're not overly powerful?](https://worldbuilding.stackexchange.com/questions/127133/how-to-limit-magic-mirrors-so-theyre-not-overly-powerful) [Answer] Your magical mirrors could replace 28,000 kilometres (17,400 miles) of Optical Fibres. The total costs of the cables currently laid is estimated to be about 1.1 billion (Source below article). <https://en.wikipedia.org/wiki/Fiber-Optic_Link_Around_the_Globe> In simple terms, the communications happen by having an array of high-speed LED placed across the surface of the mirror, pulsing 1's and 0's in various frequencies of the EM spectrum (infrared, microwave, visible light, ultra-violet). The bandwidth capabilities of such a set-up would be orders of magnitude higher than traditional Optical Fibres. We are speaking of several Peta-bytes per second, using a single pair of 50-inch mirrors here. You could take this further and have miniature mirrors embedded inside electronic devices and totally replace Radio-waves with mirrors. GSM, 4G, Wifi, Microwaves would all be brutally killed, given the high bandwidth and power-efficiencies of these mirrors. Our networking protocols are pretty robust and allow interfacing between existing and new communication technologies, pretty easily. So, the new iPhone (or more probably Samsung) might support Pavel Mirrors as the cutting edge communication system. The monetising potential is several Billions for sure. Since many readers on this site might not be familiar about how optic fibres work, here is an over-simplified description. Imagine you had one of these mirrors placed right in front of a Television Set and another in front of you. But, you are sitting miles away from the television. If you now point your remote-control at the mirror and press a button, it would still work and the TV would switch channels or increase volume. Now imagine the TV's remote-control sensor is placed right against the mirror's surface and so is the remote-control also placed against the surface of the other mirror (the positioning matters). This would allow you to place multiple remotes and sensors and also run them with less power. Typical TV remotes use Infrared light. But, there are LEDs and sensors available for other kinds of lights, like Red, Green, Blue, Yellow, UV. This means you could tightly pack these sensors and still prevent them from interfering with each other. A cheap TV remote LED can only pulse a few thousand times per second reliably. But, there are LEDs that can pulse trillions of times per second in multiple light-frequencies simultaneously. These are the once used in Optic-fibres and you could use them here too (if you have Trillions of TVs or to send data across the ocean). [Answer] The military and organizations that need absolutely secure data transmission, like government agencies and banks, would love your mirrors. The downside is that these will require some proof that your connection is indeed absolutely secure, so there will be research involved. **The biggest group that could profit from such mirrors are researchers.** Imagine how extremely costly it is to create a deep sea submarine. Now they can basically hang a Magic Mirror on a really long fishing line and be able to see the deep sea. Wildlife observation can be done in real time without hiking to remote places to change the batteries of a camera. Imagine a new Hubble Telescope with Magic Mirror technology! You only need to transport the outer shell and one big mirror\* into space. All the optical lenses, cameras and equipments that actually take and analyze the pictures can be stationed on Earth, easily maintained and replaced when better technology is available without sending them into space. \* The helpful comments made me realize that I was mistaken. You have to transport almost the whole telescope into space, only the lenses and optical sensors can be stationed, maintained and replaced on Earth. The same applies to space probes. You can send a Voyager III on its way now and replace sensors, cameras and other equipment here on Earth during its journey. If any kind of optical and sound wave is transmitted through the mirror, you can use technologies like sonar, microwave, infrared, visible light, x-rays and many more with it. The possibilities are incredible. [Answer] Another use for those mirrors is for light transmission, especially sunlight transmission. One of the biggest problems with solar power, both electric, thermal or directly as light, is that it is inconstant. Night, winter, bad weather... But if you put mirror farms in hot deserts with constant clear weather in a way that there are always some in full sunlight, you solve that problem. High-quality, natural sunlight, both domestic and collective, is directly available. To heat something, especially low-temperature like domestic heating or hot water, no need for burning fuel or using electricity. Simply use a thermal oven or water heater lit by one or more mirrors. Solar farms, both photo-voltaic and solar-thermal, can output constant electricity 24/7, and can be protected from weather. You have the potential to revolutionize energy generation and distribution here, but only start exploring it once you made a boatload of money through other application. It is an industry with extremely powerful vested interests, and you will need to have your own major lobby to really develop it. Given what you've stumbled into, you should be richer than some nations in a few years anyway, so this shouldn't be a problem. [Answer] Nobody seems to have monetised them evilly. Sell them to banks, law firms, businesses, high power executives, and city bars. Either utilitarian, for bathroom/toilets, or with high class frames, for boardrooms, meeting rooms and (in private houses) bedrooms. Now listen, watch and record them, on a remote mirror. You only need to catch a few people discussing business changes, negotiations, or plans, with a colleague, while they wash their hands or check their appearance, or a heads-up on some shifty practice or secret affair. Or even pay them to put a small mirror in the CEO's office. Either advance business knowledge, or blackmail. Your choice. Both could pull in a fortune. Personally, I'd go for business intel any day, much more valuable. It's worth watching mirrors for a few hours when there's an important meeting, to get a few days advance knowledge of a proposed takeover bid, new product or strategy, or anything else. A company's shares can go up or down, and you can profit heavily either way - many, many times a year, and no way to prove insider trading or illegality. [Answer] ***Reactionless space drive*** Magic mirrors don't conserve momentum. When a normal mirror reflects light, the momentum of the photon is reversed, giving an impulse to the mirror. Now if that light is caught by a magic mirror and it's partner mirror is pointed back at the normal mirror, I get the same photons back again. My thrust is limited only by how close to perfectly reflective my normal mirror is. ***Free energy*** Same concept as above, but designed into a wheel like device. Thrust rotates a wheel, which spins a generator. ***Klingon cloaking device*** You have paired mirrors on opposite sides of the hull. When engaged light that hits one mirror is passed to the opposite mirror. Note that this won't be perfect. Off axis incoming photons will be displaced to the side. This can't be corrected easily without additional spells. ***Cheap streetlights.*** A mirror is matched to one on the opposite side of the world. Similarly flashlights that never need new batteries. ***Industrial Heating*** If it handles sufficient intensity then a mismatch in sizes makes some interesting industrial processes possible. *(May have some problems with the laws of thermodynamics, but hey, this is magic, right?)* Consider a 2 meter mirror connected to a 1 mm mirror. Put the big one outside. Now you have about 4 kW coming out of a hole 1 mm in diameter. Welding/cutting tool? How do you turn it off? Anything you put in front of it will heat up. So you need an extra spell so that the mirror on hearing "Mirror off" will turn off. Consider a bunch of these all pointing at a crucible. If you can develop very high temperature mirrors, it should be possible to ***build rocket engines*** that use H2 as reaction mass. This gives you a huge increase in specific impulse. Or use water. Not as efficient but cheaper. Like present rocket engines, you circulate the reaction mass in the bell of the rocket to keep the bell below it's melting point. ***Space Lasers aka Reagan's Star Wars*** Mirror is in space. Lasers are on earth. You still need a pointing/tracking system, but the heavy stuff is down here. Or match enough big mirrors in orbit, and you don't care about the 1/2 degree divergence of sunlight. ***Unlimited bandwidth for space probes*** Present deep space probes are limited by the power required to send data back to earth. Some were sending images back for months after they passed their target. ***Untraceable internet*** Build the mirror into the same case that has an led. Pulse the Led. A single pair creates a simplex channel. Two pairs give you full duplex. (While the mirror itself conducts light both ways, receiving while the led a half mm away is shining may be difficult. The Dark Web is going to love this. ***Cellphones work EVERYWHERE*** No lost signal. Be a boon for remote locations underground, in the sea where otherwise communications have to use clunky radios or satellite communication. Also you aren't spending energy broadcasting. Use a kindle type screen, and a phone should be good for weeks. Criminals and conspiracy theorists would love this as it's inherently untraceable. ***Universal fast internet*** No more of this, "I live in the sticks, and can only get 33 Kbaud dialup. Or pay $100/month for 1 Mbit satellite" ***CO2 sequestration & fish farming*** Put a larger (1 km mylar film?) mirror in some sunny climate. Put the matching mirror on the abyssal plain in the ocean. Warm up ocean water. The sunlight pouring out is absorbed by the water. Hot water rises, carrying with it nutrients (upwellings are reasons arctic waters are so productive) The abyssal water is lower in CO2 than surface water. The nutrients create a plume of phytoplankton where it meets the surface. ***Solar Power Storage*** Solar thermal storage right now has a lot of plumbing issues with heating the molten salts while keeping them from solidifying. Put mirrors on the surface with their companions in the salt tank. Tank heats up until it's radiating/conducting energy out as fast as it's being poured in. This tank is easy to insulate and it doesn't have to be on a high tower. Note that for this use, you may have to use pyrex or stainless steel mirrors. ***Home heating*** You have an insulated water tank in your basement with a mirror in it. Mirror partner is in the opposite hemisphere so it's summer is your winter. Circulate hot water as needed to warm your house. Or more likely two mirrors, depending on the variation in heat needed at different times of year. ***Thermal Underwear.*** Apply magic mirror to thread. Put the matching garment in a warm place. If the mirror works with infrared, you now have a layer of that is at the temperature of the warm place. In summer you could air condition the home mirror and be cucumber cool during a heatwave. Could you kill someone by putting his remote longjohns in a kettle of boiling water? Apply this to walls with the corresponding mirror in the ocean or lake, and you have ***cheap air conditioning.*** Radiant energy in the room would sink into the mirror with little coming back. 100 F differential corresponds to about 75 W/m2 Might have condensation issues. *(Ok, you polish a sheet of steel to the point it can be a mirror. You make a magic mirror out of it. The other end is in the middle of Antarctica. Your end is on a warm wood stove, facing up. What temperature is your mirror?)* Put one on the abyssal plain, and one in the air out of the sun. Radiant energy vanishes into the mirror, and the surface cools. ***Water supply*** from condensed moisture in deserts? ***High Altitude Observation platforms.*** Build a balloon, spray it with 1" of very low density foam. Mirror on the outside and the inside. Lower half of the inside of the balloon is painted black. Sunlight hits the external mirror, goes inside, bounces around until it's absorbed, heats the air up. Permanent hot air balloon. ***Navigation systems*** Right now we have a bunch of expensive satellites in orbit to run the GPS system, and there are a bunch of reasons that the location isn't perfect. Suppose you have a set of broadcast mirrors that allow attachment by anyone. Instead of a microwave signal, you encode the same sort of protocol on an LED behind the broadcast mirror. Your MagicGPS receives the signals from 4 or more mirrors and uses this to compute location. The computations are much simpler, since the mirrors are fixed in space. Since they aren't in orbit there is no relativistic correction. (Ok, still a small one if you are way above or below a mirror) No atmospheric jitter. Should be able to easily get sub meter accuracy. And if you can detect the frequency shift (tough 22 m delta-h corresponds to a frequency shift of about 4.5 \* 10^-15. ) you'd have corresponding elevation as a sanity check. (I'm trying to figure out if a magic mirror has a place in either ring laser gyros or fiber optic gyros. Do mirrors preserve phase information?) ***Interesting art*** Your mirrors are made of VERY thin glass. (I've seen a glassblower pop a glass bubble, and the shards floated around for minutes.) So you have very thin mirrors floating in water. The matching mirrors are in varicoloured lights. Which leads to ***Full 3D displays*** Multiple mirrors are printed on tinsel like strips of clear plastic. The strips are hung in a liquid that has the same index of refraction. Ideally for this you want a mirror that only works one way, and is transparent to local light. But failing this if the tank mirrors are tiny compared to the pixel volume it will still work. Not that this will work as a 'ghost' world. One object won't block another. [Answer] ## High-frequency Traders Nanoseconds matter in high-frequency trading. The people involved in these businesses spend millions on dedicated processing hardware and point-to-point fibre links. In HFT, the curvature of the Earth matters, and the difference between the speed of light in air and the speed of light in glass also matters. These mirrors cheat both, and get the speed of light in vacuum and can shave hundreds to thousands of miles off round-trip times between distant locations by going through the Earth rather than round it. There are other applications, but these are going to be the ones who have the highest willingness to pay for the extra performance and reliability you can deliver in the short term. Once you're established (and most importantly, have the capital to invest in some personal security to stop ne'er-do-wells from stealing the tech or kidnapping you) you can move on to lower-margin groups like telcos, space administrations, intelligence agencies, and suchlike. [Answer] Sell them, at extortionate prices, to people who need guaranteed connection in inhospitable locations. Sailors, mountaineers, backpackers, spelunkers of various kinds (Thanks Arcanist Lupus), the military: all these people will pay through the nose for a powerless, guaranteed to connect, uncrackable communication method. As for repeat custom: mirrors get broken. You can count on people to need replacements every so often. If the initial price point is set correctly and you control the means of supply then you can make a killing even without ‘subscription fees’. [Answer] NASA, version 2: Powering spacecraft in the outer solar system is quite problematic. Solar cells are weak at Jupiter and pretty much useless beyond that. That means only nuclear generators--and those need synthetic (expen$ive!) isotopes to run and seriously limit the power available to the spacecraft. (We are currently using up stuff made in the cold war. A few more probes and that will be gone--and there will be no source of RTGs for the outer solar system.) Instead, we put a mirror in our probe. We shine through it a very bright light of the right frequency to get maximum yield from the solar cells on the other side with minimum heat production. Yield should be far above current efficiencies. As has been given in another answer this mirror is also the communications device. Presto, we just replaced the entire power and communications setup with a couple of pounds of stuff. As a secondary effect power isn't so critical anymore, we don't have to jump through every hoop imaginable to minimize power consumption. I wouldn't be surprised if NASA would pay $100 million for a mirror pair. [Answer] Another way to the mirrors can be used is for data transfer. An optical pulse sender and Receiver at the other end would be a way to get data across continents absolutely secure with the speed of light. Stock exchanges, Banks, Military, etc would use such a technology for even faster communications. You could manage a Profit from high Quality mirrors that have not or only a tiny amount of surface errors so the optical pulses come through bright and clear. [Answer] Congratulations, you've just created the new state-of-the-art mobile phone screen. Instead of carrying around a bulky, battery powered phone, you can just have a mirror that interfaces with a larger device at your home. No more connection issues either - the age of the landline and mirror is in, and with our cloud partnerships, you can travel without having any significant latency. [Answer] # Congratulations, you just violated the [First Law of Thermodynamics](https://www.wikiwand.com/en/Laws_of_thermodynamics) and discovered a [perpetuum mobile](https://en.wikipedia.org/wiki/Perpetuum_mobile). The implications are too huge to consider in a short answer, could be anything, but I presume blowing up the Universe will happen in near future. Consider these of your conditions taken together: * Mirrors can [only] transmit sound and vision * Yes, the connection between mirrors seems to be free * you can assume both (only one-to-one connection possible) or one-to-many connection is possible So, mirrors are not only cost free transfer of electromagnetic and acoustic waves, the one-to-many connection additionally means they can actually MULTIPLY photons: you shine a light into a 1-to-2 mirror setup, you get 2 rays of light coming out of 2 different mirrors. Since each photon [carries energy](https://en.wikipedia.org/wiki/Photon_energy), you've just got yourself rayful of energy *for free*. Presumably, if you connect the output of the 1-to-2 mirror to other mirrors, so that they loop back to the first mirror, the only energy loss will be during the distance between mirrors, more than compensated by the fact that you will get 1 ray for free. What you want to do with this, is have somebody who understands physics better, put safeguards in such a setup, so that when the energy levels exceed safety margins the mirrors are blackened. Considering, however, that the energy increase speed seems to be at the speed of light, the chances of you not blowing up the Earth along with your mirrors seem slim to me. But then again, IANAP(hysicist). If you really need advice on how to exploit free energy, maybe better sell the patent to somebody. But consider that it is not as if you can hope to conceal the secret for long, as the patent is a public thing for all to see. Somebody will make the setup ... and sooner or later somebody will miscalculate and blow up, at the best case, only the mirrors. In the worst -- maybe this part of galaxy. UPDATE: Mirrors is the wrong term to use for such devices, they do act more like the portals from the Valve computer game "Portal", as mentioned in the comments. Consider this loop: [](https://i.stack.imgur.com/vYGvD.jpg) The mirror A is paired with mirrors B1 and B2, so that everything you shine into A, goes to both of them. It will receive an ever increasing stream of photons, which, it seems to me, would blow a normal mirror to smitherens due to absorbed heat. Unlike the magic mirror, which appears to be not a mirror at all in fact. [Answer] Unlimited Free Clean Energy. Take the fuel rods out of a nuclear reactor. Put a mirror in there. Launch a paired mirror into a really tight orbit of the sun, putting a spin on it such that it always faces the sun. That mirror will be bombarded with blindingly intense light. That light will pass through to the mirror on Earth, and be emitted into the reactor. Now you're powering a nuclear reactor (now a fusion reactor, if even that, since the fusion is happening offsite) without using nuclear fuel. But the point is, you can get unlimited free clean energy from the Sun by just putting a mirror up close to the Sun [Answer] An ISP could make the mirrors part of their Internet infrastructure by bolting the mirrors down and lining the surface as densely as they can with fiber optics. You didn't specify the size of your mirror, but if it's about as big as an iPhone 4, it will be $2.91 \times 1.94 = 5.65$ square inches, and since each cable is about $0.005$ inches across, you can fit $582 \times 388 = 225,816$ cables on your mirror if they're grid packed (even more if they're hexagonally packed). You would likely need some spacing between cables to account for alignment errors, but that's still quite a bit of available bandwidth that an ISP would pay through their ears to have. [Answer] Video conferencing that actually works. 1. Build a really big warehouse. 2. Make a whole lot of mirror pairs. 3. Put one mirror out of each pair in the warehouse. 4. Build a robot that can push the mirrors around such that they face each other. 5. Sell the remaining mirrors as the world’s only dedicated, lag-free, zero-setup, video-conferencing system. 6. Charge a mint for each mirror. 7. Profit. [Answer] **It may not be possible to use mirrors through the Internet, but it is possible to use the Internet through the mirrors**. A crude version of this would be to hook a computer up to a light source and a camera, then point it at a mirror. Do the same thing with the computer on the other end. As long as both computers agree on how a basic signal should be encoded (maybe using different colors of light, so that if all the lights are off you know something is wrong), this setup can act as the *physical layer* of a network connection, replacing things like copper wires or fiber optic cables or radio waves. Then the computers could link up, probably with something akin to PPP, and you're on your way. (Hey, [they've figured out how to use the Internet through carrier pigeons](https://en.wikipedia.org/wiki/IP_over_Avian_Carriers); they'll figure out how to do it through magic mirrors). Why would people do this? **If there is no signal travelling between the mirrors, then communications become *much* harder to intercept**. Intelligence agencies will love them. So will banks. Criminal enterprises will probably also be fans. [Answer] If these mirror don't require any physical connection, and yet they are able to transmit light and sound in perfect fidelity from one point to another at the speed of light, it is very likely that they can do even more than this. You have no idea how it works, but are able to follow simple instructions which it sounds like anybody could do to build the mirror, so the principles involved appear to be fairly simple. Specifically, it's not like a building a large computer where you need a billion dollar semi-conductor fab to build the wafers, it's more like the first transistor where you can build one out of materials that you are able to obtain. Depending on how magic works in your world, it may be that like building a transistor radio that takes up a kitchen table, there is a 50 year or more technological growth curve where this sufficiently advanced technology can be studied and refined. Or alternately, magic in your world may be totally separate from physics and follow its own rules or logic. Either way, the value is this is potentially incalculable. If you are willing to put the time and effort into it yourself, you could raise venture capital and lead the effort to research how the mirror works and additional effects that are possible. If you can send light, what other things can you send? Can you send gravity? If you can send sound, can you send other kinds of physical vibrations? Can you send matter? If so that would be of immense value as your magic mirror is now a teleporter. The sorts of research into exactly what sorts of things you can do and what sorts of things you might be able to do with tweaks to the mirror could take years, but also disrupt entire industries. If you don't want to put all the work in, you very likely could make a great deal of money selling the information on how to build the mirrors to a third party - just be sure to put together all these thoughts into what exciting and valuable possibilities could be made available and require that the deal allows you to reap rewards proportional to the advances are made, instead of some fixed sum of money. Even if your mirrors are only ever capable of sending light and sound, how much light? How much sound? Is it just the visible spectrum or other parts of the electromagnetic spectrum? If there is no attenuation of the signal, then a large mirror was placed in orbit closer to the sun, and a great deal of energy could be beamed directly to the Earth for a variety of uses. Even if your mirrors actually behave no differently from a camera / screen setup, as the other answers mention you still have what seems to be a more reliable system not requiring wires and possibly even noise free transmission mechanism. What if millions of these mirrors were made, but microscopic in size, you could have a revolution in computers as you eliminate the need for comparatively slow electrical paths. Is there any limit on how many point to point connections can be created at once? It sounds like you may have a better crossbar mechanism as well. The possibilities are endless. Play your cards right and you'll be rich beyond your wildest dreams! [Answer] You could really spruce up your inner city flat with a sea view of the Bahamas. I know this probably wouldn't be nearly as lucrative as some of the technical breakthroughs - but it could still make a tidy margin. You could sell 'windows' to any landscape you liked - large mirrors paired with a second mirror in a beautiful location.The more sought after location, the higher the price. The natural lighting (with, I assume, perfect 3D), full natural sound, and no power consumption would make this much more desirable than a similar digital screen. Also the remote end would need little maintenance, except occasional window cleaning (A bird dropping could be very annoying though!). You could also create full surround experiences, by constructing two small buildings of paired magic mirrors, with one set of mirrors pointing in, and the other pointing out. You would have to consider possible jet-lag effects, if you placed paired mirrors in different time zones. In some cases this could be turned into a benefit however - such as being able to watch a meteor shower in the Himalayas at tea time in the UK. Imagine the potential for an exquisite, romantic, restaurant experience, when used with the full surround concept. It could even be marketed as a cure for seasonal affective disorder. Those dark evenings pulling you down? Here is some equatorial sunshine! **Edit thanks to Mark Carney's comment** There are a number of issues with using these mirrors in this way- in that, as with windows, sound and light transmission go both ways. Two significant problems are peeping toms and noisy neighbours. The windows could be used by bad actors to spy into people's homes. You could also hear the noise from neighbouring mirrors, if the away end of your mirror was placed near to other mirrors. However this can be turned into an advantage, as you can charge for solutions to these problems. They could range from simple soundproofing with double glazing for the average householder, to having your own guarded lot with a guaranteed minimum distance from sources of sound pollution for richer clients. [Answer] > > Hello, NASA. I've got these nice deep space communication relays for you. For $1,000,000 each, we can set up a paired link requiring only one pound payload, no power, no danger of interception, and really high reliability. We've been running some tests and managed 100kbps, but we think 10s of megabit is possible. Yes, you can verify this all works on the ground. No problem. The patent number is 383121323. > > > [Answer] They would be great to overcome security measures preventing signal to get in or out of buildings, places, in short: spying devices. As long as they aren't very unique-looking, you can install them in place of real mirrors, maybe even replace windows, etc. You might need to do a bit more research to make them one-way and transparent, respectively, but it would be probably worth the gain (unless you get killed by people who don't want such a technology out there). [Answer] If you're the evil sort, you can make money from this in all sorts of different ways. Don't reveal your discovery to anyone, ever. Slowly acquire all of the major mirror manufacturers until you control the entire market. Start selling magic mirrors, but don't tell anyone that they're magic. Only sell one mirror from each pair, and keep the other hidden in storage. Once your mirrors have become ubiquitous around the globe, buy the most powerful industrial laser you can find. Now, you can activate a mirror for a brief moment and blast it with your laser, destroying whatever's on the other side of the matching mirror without any warning. For a subtler approach, you could use something like a cyclotron instead and irradiate your victim while they sleep. Since nobody else knows magic mirrors even exist, the crime never gets solved. Hire yourself out as an assassin. Extort money from anyone, anywhere. Mail someone a mirror in a box and rig it to activate as soon as the box opens. The possibilities are endless. The *truly* evil sort could even come at it from the other direction. Sell the mirror pairs as the amazing two-way communication device that they are, and wait for the fad to catch on. As the other answers indicate, people will quickly develop all sorts of creative uses for them. Now, you can step in and make lots of money by selling mirror *blocking* technology. Want to make sure your corporate boardroom or mafia safehouse isn't mirror-bugged? Want to make sure your citizens aren't using mirrors to bypass government surveillance systems? Tired of teenagers sneaking mirrors into your movie theaters to avoid buying tickets? Well then, you'd better pay up. [Answer] The military would eat this up. If you are a soldier, this is the single greatest invention to ever make your life saver. Not because this invention is useful by itself, but because it has tons of applications in the field. **Communication** Some people have already pointed out your mirror's use in communications. This by itself is impressive- talking to someone a country away is difficult when you are in hostile territory that has little communications infrastructure. A mirror is secure, dependable, and doesn't need electricity to call home. Imagine a building full of mirrors, filled with experts in the field of warfare. First, there's the commander. They can relay orders to all the mirrors in the building via a PA system. Then there are doctors, tacticians, counselors, explosives experts, anyone a soldier could possibly need to talk to for any kind of advice. Soldiers can even talk to their families every once in a while. All of this is possible without risking a single one of those experts into the warzone. **Entertainment** Life as a soldier is pretty hard. You're stuck in enemy territory for an indefinite amount of time, and you can't even get some decent music. With a mirror, you can just ask your counselor to play some music or a video from a computer on the other end. (Either all of the mirror's functions will use voice commands and voice recognition, or everyone will have a dedicated operator who turns the music on for them, calls for the counselor, etc.) **Lasers** As if that wasn't enough, you can weaponise the mirrors. Just pull a large mirror out of your pack and say "laser", and a second later, your mirror is shooting high power lazer light at your foe, incinerating them and setting their clothes ablaze. No ammo, bullets, or charging required. The laser also makes a good fire starter. Assuming you haven't given up on guns in favor of the clearly superior mirror technology, a weak laser can be used as a sniper scope. **Radiation** If you need to *really* take the weapons to the next level, you can have your mirror shoot gamma rays, x-rays, or any form of radiation you want. It's a pretty cruel death for anyone on the receiving end, but microwaves can be used to cook your rations, and two soldiers with their mirrors facing each other can be used as an x-ray machine, able to see inside anything between the mirrors. You can see exactly what each soldier in an enemy camp is doing inside their tent, and you can locate where all of the weapons are stored. **Light** This is probably the most useful flashlight ever made. It needs no batteries, and the brightness is adjustable. Some of the side benefits of this flashlight, aside from seeing in the dark, is its possible use in signaling or as a flare, and its ability to blind when at full brightness. **Compact size** I don't think other answers realize that you can have two mirrors of different sizes. A soldier can hold a small mirror while the mirror on the other side is nice and large to get a good picture, and to focus anything shining through the mirror down to a more precise point. **Captured weapons** Because only one person in the entire world knows how to make the mirrors, the enemy won't be able to make mirrors to spy on your army. Typicaly, when a soldier is captured or killed, the enemy takes their weapons and communication devices. That's impossible with mirrors. First of all, when the enemy looks into the mirror, suddenly his head is balsted off by a laser. The enemy can't use a comadeered mirror anyway, the operator or voice recognition won't do it. The easiest thing for the enemy to do with the mirror is to smash it before you figure out how to send an explosive payload through and blow them all sky high. Initially, when the enemy doesn't know the limitations of the mirror or how it shoots lasers, the most subtle way to kill your enemies is to shine gamma or x-rays through, giving anyone near it radiation poisoning that will be noticed much later. When the enemy figures out that the mirror is two-way, they will try to send their lasers through to kill anyone on the other end that they can and destroy whatever equipment is there, so the best course of action is to destroy or disenchant the mirror before the enemy can use it to their advantage. [Answer] Speed-of-light communication with no signal deterioration or noise? As in, no matter how far away I place the mirror, I will not have to spend more energy to send to it, or more computing power to try to decypher the response? Sign me up! And for dirt cheap, too! Lots of Ideas on the practical use for this have already been posted as answers, but it all boils down to this: the magic removes the two biggest issues we have with communication. Any military would love it, any space agency would LOVE it (if a mars rover could just blink a LED at a mirror instead of radioing a sattelite in orbit which then laser-pulses towards a sattelite orbiting earth which in turn radios the ground base or somesuch, that would be sweet)... Heck, there's currently plans to send microsattelites towards the nearest star. They'll be in transit a couple decades at least, but equipping them with your mirrors would at least make the "and send the data back" part a near non-issue (although the lightspeed limitation would mean waiting another 4+ years for the data. Still better than waiting the same time and then getting a garbled, weak mess of a signal!) Also, note that telescope resolution is limited by the size of the telescope - so a bigger mirror/lens is better... but that same size can (with enough computing power) be emulated by having multiple small ones at a far enough distance. Loss-free communication between telescope sattelites and the ground station via magic mirrors would be invaluable. In short: Any space enthusiast will love this! [Answer] Wow. Lots of answers about what you could do with them - the list of which is pretty much endless - and not so many directly addressing your actual question: > > Is there a way to make money in today's world by selling magical mirrors which can provide sound and vision connection to each other? > > > Why yes, yes there is. In fact there are several ways you can do it, and some of them don't even have ethical problems. 1. Assuming that you can't stop others from creating them, your patent guarantees that anyone who is making these things in the areas covered by the patent are liable to pay you royalties on their manufacture. 2. Demonstrate the mirrors to the major manufacturers of fibre optics. Tell them that you're ready to go to market but could be convinced to not do so if given enough financial incentive not to. 3. Setup a registry for mirror names and require anyone who is going to licence your process to purchase a subscription to the registry. 4. Sell mirrors that have names that cannot be pronounced by humans and licence a device that will connect those mirrors. 5. Only sell mirrors that are pre-paired, using names that are virtually impossible to figure out. Any attempt to reconnect the mirrors will break the connection and only you can re-connect. 6. Sell the patent for a ton of money and let someone else figure out how to make money off it. 7. Sell some mirrors for a small profit, let others examine them and figure out how to recreate them, become the greatest patent troll in the history of the world. There are probably many others in a similar vein. Ultimately though you'll probably be wanting to get as much money as you can right up front, because eventually the technology will get out of your control. Inside of 5 years there will be factories in China churning them out for pennies and trading them on Wish free plus postage. Second generation mirrors will have integrated electronics to facilitate connections, people will be hacking the mirror network by computer-driven name scans and auto-connect DoS, etc. Take the money and run :) [Answer] Most of answers were focused on data transmission like improved version of fiber-optic channel. Althought I liked *evil solution* from @Stiliez and energy transmission from Sahara by @Eth I would like to talk about casual contacting. First, like @Elmy and others mentioned, there are many people who need communications where electrical power inaccessible or too limited: * Long-term expeditions made by ethnographers, geologists, speleologists and to poles * Residents of remote villages where it's too costly to lay data cable * As improvement of cameras installed to investigate animals in wild. (Set up first small mirrow in wild, second in dark silent room with recording devices) Second, someone would want to communicate secretely. * Any spy would happy with reliable, undetectable and un-suspicious communication channel with Center * Strategic submarines in particular and Navy in general * Goverments and corporations would be intrested mostly in solutions which guaranties not the fact of communication but content of communication. And third, the most dangerous for civil society, as spying devices for goverments (or, probably, for corporations). Scenario is the same as wild animals: first mirroc is small and hidden while second mirror set on small dark silent room with recording devices. * Spying for enemies both actual or potential or just political opponents * The worst scenario was [described by Orwell](https://en.wikipedia.org/wiki/Nineteen_Eighty-Four): each mirror spying for everyone (it's cheaper than many cameras which require data and energy cables) [Answer] The simple answer is that you make money off a thing by selling it for more than it costs you to make it. The thing doesn't even have to be useful. Ty Warner became a billionaire by selling useless stuffed animal dolls ("beanie babies"). Seems like a genuine magic mirror could be the next hot novelty gift for whatever holiday season is around the corner, with a decent ad campaign and marketing team. ("As seen in Fantastic Beasts 3, really works!") If, as the other answers suggest, they have useful applications too, so much the better - you could make yourself a millionaire many times over selling cheap novelty versions to Harry Potter fans, and a billionaire by selling higher quality versions to industry and technology companies which will undoubtedly find numerous uses you never envisioned. (As is the case with countless modern inventions - air-conditioning was invented for the printing industry, microwaves came about from military RADAR, computers were used to break encrypted military communications before being used to deliver porn and other fringe uses, etc.) In the end, it doesn't really matter what uses you find for them, it's the uses that everyone else comes up with that will make you a fortune. [Answer] Simple, patent the technology. As you can see in the numerous answers given to your question, there are endless applications to this new technology. As a single individual, you are severly limited in capital, production capacity and business ideas and applications compared to large companies. If you patent and release the technology to the market, every new idea and application of your techology will increase your fortune and visibility. A million individuals will always have more ideas then a single individual, and with every new application a new market opens up to you. [Answer] You sell them to a high-speed trading brokerage. They already put up *billions* of dollars to shave milliseconds of transmission speed; you can own that game for the next 18 months or so. <https://en.wikipedia.org/wiki/High-frequency_trading#Low-latency_strategies> [Answer] This questions reminds me of PGR chips from first books in [Ell Donsaii series](https://www.goodreads.com/series/96454-ell-donsaii) Only differences were: * transmission time was checked and was found to be instant (not lightspeed but instant)(theory predicted just that, initial check was done with sending one of devices to australia, later checks were done in outer space) * it's not possible to block communication (works perfectly if one of devices is on underwater submarine) * small amount of power (several watts) was needed. * point-to-point only so you need control hubs. * no voice commands, it's electronic chip * initial semi-mass-produced version used USB5 for power and communication with host * it is not 'mirror' - it's data link (if you need actual mirror - add camera, display and cpu) This was enough to get Ell (creator of basic theory and inventor of this practical application) hundreds of millions of dollars in royalties in first years and billions - later. This was also caused issues with communications companies of various kinds (which was solved by licensing devices to them). I don't understood why same thing would not apply to magical mirrors. [Answer] Use them in hard-to-reach or at least hard-to-network places. Bottom of the ocean. South pole. Outer space. If you could launch a few dozen into orbit, every observatory with a decent telescope could be a Hubble, using mirrors to bypass the atmosphere. They could also guarantee communication (untrackable?) between submarines and HQ, allowing them to stay submerged and stealthy. Exploration of the Moon and Mars would no longer have the logistical headache of having to relay communication across interplanetary distances. You could even contact your Mars probe when the Sun is between our two planets. I also second the idea of using them for solar power. Leave one for me in the Arizona desert and I'll put the other in my house to have natural sunlight in wintertime. Or I'll point it right at a solar panel to charge my off-grid power system. [Answer] If your allowing a many-to-one connection how about infinite energy supply? Step one, create a hand full of mirrors and scatter them around the earth, all pointing towards the sky. At any point of time at least one of these mirrors should be getting direct sunlight. Now create a mirror A' and have that mirror connected to one of the mirrors getting direct sunlight. When the sun sets or clouds cover one mirror connect A to a different mirror, so it is always emitting direct sunlight. This mirror A' points directly at a mirror A. The net result is that we have a mirror A that anyone can connect to and get direct sunlight, no matter the time of day or weather conditions. This mirror is producing X joules worth of sunlight. Now build mirrors 1, 2 and 3 and have them all connect to mirror A, all three now generate direct sunlight. Have all three mirrors angled to point to mirror B. Mirrors 4, 5, and 6 are now created and connect to mirror B and point towards mirror C. Each of the mirrors 4-6 produces 3x joules of sunlight (the amount of light mirror B received) and by focusing on mirror C that means C is getting 9x joules of sunlight. In actuality you wouldn't get quite 9x joules of energy as not all of the sun light produced from each mirror will be captured by the mirror it points to, but that doesn't really matter. What does matter is that this is an exponential process. If you keep repeating you can get mirrors producing an arbitrarily high amount of light. Now all someone needs to do to get light energy is to connect to the appropriate mirror, with there likely being numerous mirrors all with different quantities of light depending on how much emery you want to get out of your connected mirror. From there the prospective use of your energy are practically limitless. Of course since everyone likes electricity our first step would be to put one of these high energy mirrors at the bottom of giant pool of water, pointing towards a big black piece of metal which has a high melting point. The light heats up the metal which in turn heats the water around it until it boils. Add a turbine above the water pool to be turned by your steam and you an efficient, cheaply made, completely renewable power generator. Cue near limitless electricity! If your feeling less altruistic you could not waste time building giant steam turbines and instead just point your mirror directly at someone you don't like and see how he likes being the first ever victim of solar powered death ray! Though as a word of warning you may want to make sure you understand the concept of [Convection](https://tvtropes.org/pmwiki/pmwiki.php/Main/ConvectionSchmonvection) before standing too close to your new death ray. ]

[Question] [ In my world I've created an alloy that can melt at low temperatures and solidify at high temperatures. This got me wondering, is something like this actually possible/does it exist. With most materials, of course, bonds are broken between individual molecules and atoms at high temperatures which creates a more liquid consistency. I did a bit of research but it appeared inconclusive. Is there an element or alloy that melts at low temperatures, and solidifies at high temperatures? [Answer] I'm sure this is outside of the range of temperatures you were interested in, but in the spirit of "truth is stranger than fiction," Helium-3 actually *does* this: [](https://i.stack.imgur.com/3Meuc.gif) The temperatures we are talking about are ridiculously small (fractions of degree above absolute zero), but note that the Solid region actually dips down around 0.3K. This means you can have a liquid at 3.1MPa at 0.01K, add heat to it to warm it up to 0.3K, and have it solidify on you! The reason for this is beyond my expertise (I am told it has something to do with aligning spins), but yeah... Helium does it! [Answer] # Heat drives a compound out of solution Heat can drive moisture out of a substance. If some substance mixed with water is a very viscous fluid, then driving the water out with heat could leave you with a solid. According to various pottery blogs, moist clay is about 30% water, all of which is driven out in the process of firing. A viscous mixture in solution (not necessarily a solution of water) could be heated in such a way as to drive off the solution and precipitate the results. I can think of a real life example of this: dissolve a pen's worth of ink in hair spray. Mixed together you have a black inky goo. When the alcohols in the hairspray evaporate, a hardened black mass is left. The alcohols in hairspray evaporate at room temperature, but just imagine instead a solvent that needs to be heated to be driven off. # Chemical reaction at high temperature The second possibility is if the substance underwent a chemical reaction at a high enough temperature and changed into something else that had a higher melting point, then it could theoretically solidify as the temperature went up. Clay doesn't quite undergo this reaction, but it does undergo [chemical changes](https://eic.rsc.org/feature/the-chemistry-of-pottery/2020245.article) when fired. Clay consists of a variety of minerals the most important of which for pottery are SiO$\_2$ and Al$\_2$O$\_3$, both of which come from feldspars in the clay. Firing the clay burns off organic impurities, and removes the hydrated water and K$\_2$O. Increasing the heat still further causes cross-link bonds to form between sheets of SiO$\_2$ and Al$\_2$O$\_3$, forming a compound called kaolinite, which gives pottery its strength and hardness. # Conclusion So it is plausible for a material to be heated and change its mechanical properties such that a fluid compound mixture precipitates into a solid material. The caveat is, I can't think of any way this could be a metal, since metal alloys don't form the strong covalent bonds in the clay example. It would much more likely be some sort of ceramic like the clay example. The other big caveat is that neither process is reversible. If you drive off a solvent with heat, then cooling down the resulting substance will not turn it liquid again. In the hairspray-ink example, you could re-dissolve the black mass by soaking it in rubbing alcohol, but it would take a long time (unless you ground the mass into powder first). Same with the clay example, cooling down the clay gives you hardened pottery, not lumps of crumbly minerals. [Answer] ### Almost, but generally no1 There are no such metal, alloy or pure element which does this within a reasonable temperature-pressure range2; but there are materials which can behave this way. **Why does stuff generally melt when heated and not when cooled down?3** All matter in our universe follow the bureaucracy founded within [thermodynamics](https://en.wikipedia.org/wiki/Thermodynamics) and, as part of that, all systems tries to reduce their internal energy to a minimum. A way to express the usable energy in a system is through [Gibb's free energy](https://en.wikipedia.org/wiki/Gibbs_free_energy), which tells how much energy can be extracted from a system. Gibb's free energy is commonly expressed as: $\Delta G = \Delta H - T\Delta S$ in which $\Delta G $ is the Gibb's free energy, $\Delta H$ is the [enthalpy](https://en.wikipedia.org/wiki/Enthalpy) (energy of the system, including the [internal energy](https://en.wikipedia.org/wiki/Internal_energy)), $T$ is the absolute temperature, and $\Delta S$ is the [entropy](https://en.wikipedia.org/wiki/Entropy) (the "disorder" of the system). If $\Delta G $ is negative, then it is a spontaneous process. When atoms and molecules becomes highly organized, then they can usually lower their energy by a fairly decent amount, but they lose "disorder". This means that both $\Delta H$ and $\Delta S$ are negative for something which solidifies, but as $\Delta S$ is preceded a minus sign in the equation, a loss of disorder means that it adds to $\Delta G$. Luckily, it is multiplied by $T$, so it contributes less to the equation at low temperatures. The more negative $\Delta H$ can become for a system which is solidifying, the higher $T$ it can allow without $\Delta S$ taking overhand. As long as the sum is negative, then it will spontaneously solidify. Similarly, when you increase the temperature you start to add energy to the system in terms of heat and the molecules start to move around. This creates a positive $\Delta H$, but at the melting point they start to gain enough disorder ($\Delta S$ is now positive too) from the movement so that $T\Delta S$ becomes larger than $\Delta H$. Since the "disorder" gain contributes negatively, this causes $\Delta G$ to become negative again and the system will spontaneously melt and the "disorder" in the system will keep it melted for as long as $T$ is high enough. **Things can solidify when heated, but irreversibly** [Polymerization](https://en.wikipedia.org/wiki/Polymerization) is one method of creating solids by heating; it is what the reaction is called when you create plastics. You start of with [monomers](https://en.wikipedia.org/wiki/Monomer) (the individual building blocks), which react through various means into polymers (i.e., plastics). There are several different ways for the monomers to react (e.g., [free radical polymerization](https://en.wikipedia.org/wiki/Radical_polymerization)) and there are several ways to initiate the polymerization process (e.g., through [light](https://en.wikipedia.org/wiki/Photopolymer) and [heat](https://en.wikipedia.org/wiki/Thermosetting_polymer)). The polymerization process is also not limited to petrochemical plastics; similar processes also occur with biopolymers, such as [milk proteins](https://www.researchgate.net/publication/223852030_Heat_induced_b-lactoglobulin_polymerization_Role_of_the_change_in_medium_permittivity) and [wheat proteins](https://www.biw.kuleuven.be/m2s/clmt/lmcb/publications/docs/irombouts) However, this process is usually one way, meaning that once the polymer is created, then there is no melting of it, so it remains solid. **With exceptions** However, there is a [***novel material***](http://physicsworld.com/cws/article/news/2004/sep/24/law-breaking-liquid-defies-the-rules) which breaks this rule and, seemingly, defies nature. It is an aqueous mixture of [cyclodextrin](https://en.wikipedia.org/wiki/Cyclodextrin) and [4-Methylpyridine](https://en.wikipedia.org/wiki/4-Methylpyridine), which solidifies through gelation when heated above 45°C4 and is stable due to hydrogen bond formation between the two compounds. The bonds are created in a certain way as the cyclodextrin changes shape when heated and, when the mixture is cooled, the hydrogen bonds are broken and the cyclodextrin changes back to it's original shape and is, thus, prevented from forming the bonds required to solidify the solution. So, while this example is not a metal alloy, it still shows that there is a material which can solidify when heated at a reasonable temperature range. --- 1: I misread the question and thought it said "any material" when writing my first version of my answer. 2: As Cort Ammon pointed out, Helium-3 does actually do this, but in a very small window at extremely low temperatures, which makes it highly impractical to use. 3: I'm trying to keep it simple and I am, thus, taking some liberties with the truth. 4: The article states "between 45°C and 75°C, which I interpret as that the compound is destroyed if heated more. [Answer] The examples of polymerization, evaporating water, and chemical reactions in other answers are usally *irreversible*. This is fundamentally different from reversible changes of physical state such as solid < > liquid < > gas. If you don't mind some arm-waving about a technology that hasn't been discovered yet, there could be a few options that would be reversible: * Some sort of exotic shape memory alloy, which can be converted to a liquid by some means at low temperatures, but "remembers" is it a solid when it is heated, and returns to its original shape when it solidifies. * Some weird ferromagnetic material which behaves like a liquid below its Curie temperature when the magnetic effects are working, but like a solid at high temperatures when they are not. * Some sort of superconducting alloy, which only behaved like a liquid below its critical temperature. [Answer] You specified an [*alloy*](https://en.wikipedia.org/wiki/Alloy) and you probably intend to mean anything that acts as a metal, including modern things like [CPM](https://en.wikipedia.org/wiki/List_of_blade_materials#CPM_Series) so long as the bulk properties of the result seems metal-like rather than (say) ceramic. Cort’s note on ultra-high pressure helium (“something to do with aligning spins”) gives me an idea that could be useful for realistic handwaving in your story. You know what else has to do with aligning spins? [Ferromagnetism](https://en.wikipedia.org/wiki/Ferromagnetism) and [Ferrimagnetism](https://en.wikipedia.org/wiki/Ferrimagnetism) allowing permanent magnets to exist. A quirk of energy levels *and atom spacing* dependant on spin alignment means that it is favorable to have spins aligned because the energy associated with the different spacing more than make up for it. Imagine a powerful magnet (like today’s rare-earth magnets) being developed (for electric vehicle motors) that incorporate molecules or nanoparticles that are dipoles (like water famously is). Water is anomolus in just about every way possible because of the dipole and hydrogen bonding. The researchers were trying to exploit the spin vs lattice spacing relationship to make powerful compact permanent magnets that don’t demagnetize when subjected to high-power fields in the motor. But, above the [Curie temperature](https://en.wikipedia.org/wiki/Curie_temperature), the situation changes. Without the influence of spin effects, a different lattice is preferred and the material changes state. So, first the material melts at high temperature, but maintains the exotic structure at the nanoscale, like a liquid crystal. Keep heating, and the spin coupling effects drop out and it changes state, and the new state is solid at this temperature. As long as the nanoparticles are intact it’s reversable and will re-form the ferrimagnetic state when cooled. At sufficiently high temperature, though, you cook the nanoparticles or cause changes to those asymmetric molecules, and wind up with a mundane material (perhaps a ceramic). The exotic material is metal-like in bulk because it is a conductor of electricity and an excellent conductor of heat, even if [not via the same mechanism](https://en.wikipedia.org/wiki/Material_properties_of_diamond#Thermal_conductivity) of a natural [metal](https://en.wikipedia.org/wiki/Metal#Electrical). These are desirable properties for its original purpose to make motors. [Answer] Tin might fit the bill in some respects. <https://en.wikipedia.org/wiki/Tin> In warm temperatures it is metal and you can make stuff out of it. In cold weather it shifts to a different configuration which is nonmetallic, nonconductive and does not hold together - not melting but coming apart into powder (tin pest). Close to what you want in that the warm version has structural integrity and the cold has not. But not liquid / solid. [](https://i.stack.imgur.com/G9tCM.jpg) video of tin pest in action found <https://www.youtube.com/watch?v=Q9zdt-rOB0Y> [Answer] ### Nope. This goes against the laws of physics, it's like inventing a light bulb that *sucks away darkness* to *reveal the light hidden "underneath"*. It's about heat and pressure, these are the two things that force matter to change its state. Granted, there are some weird states of matter, but if you want to actually melt and solidify matter there is only one way. As stated in the comments and other answer, there are ways to have "matter" become "hard" and then "soft" again in other ways, but that has nothing to do with the state of matter as you describe it. [Answer] OP has said "alloy" but what about a compound of nanobots? It could be programmed to perform in the way desired, against Thermodynamics. Nanobots might not fit in with the rest of the World though. [Answer] Just 1¢ addition to other answers Melting temperature may depend on a size of nanoparticles, and it is one of the problems in making them, as it begins to be too low. As size of particles begins to be smaller, surface tension of the droplets begins to be more significant part of the total energy of the particle, as volume of the particle reduces proportionally $\sim r^3$ and surface $\sim r^2$ Dependence is not linear, an example with tungsten, from [Melting tungsten nanoparticles: a molecular dynamics study](https://pdfs.semanticscholar.org/f88c/dad87dd57c2803b95ebade128c520f8e02cc.pdf) [](https://i.stack.imgur.com/Uce6C.png) Such particles, in theory, may contain shells with different properties - oxide layers to prevent agglutination for longer period of time, other metals to form solutions with lower or higher melting point than original metals like [Wood's metal](https://en.wikipedia.org/wiki/Wood%27s_metal) or changing melting point of a nanoparticle, or creating solid-liquid mix, shapes of nanoparticles embedded in metal nanoparticles (like CNT, monocrystals - hedgehog style) etc etc. Shells are not necessary it may be a mix of different sizes nanoparticles of the same metal of different metals etc. All that may allow creating of interesting mixes of metal and(or) nonmetal nanoparticles with different time-temperature-phase dependencies of the mix. It will be(probably most of the time) one-time one-way mixtures - but with creating different macro objects it will be most likely one would wish. [Answer] With increasing temperature, we get increasing disorder, so it would be very strange for a substance to solidify with increasing temperature (unless water vapour or or other liquid is driven off as mentioned by Kingledion.) However such substances do exist, as mentioned by Mrkvicka. Similarly, and equally counterintuitively, ice gets denser when it melts. The thing that must increase as temperature increases is disorder. In the case of the density of water/ice, it just so happens that ice's most ordered structure has a lot of empty space in it, which explains why it is less dense than the more disordered liquid form of water. As you asked for an "element" or alloy that solidifies when heated, it is worth mentioning pure sulphur, which comes close, in a way. It has a vast increase in viscosity as it is warmed. It starts off as an ordered crystalline solid of S8 rings, which melts into a runny liquid of S8 rings. At a certain temperature, these ordered rings break open and a highly viscous polymer develops, with lots of different chain lengths. On further heating, this breaks down into a runny liquid of formula S2 and finally into gas. Mrkvicka's example is similar in that molecules have an ordered sysem of intramolecular hydrogen bonding at low temperature, which becomes a disordered system of intermolecular hydrogen boning at high temperature. However there are also big differences: In Mrkvicka's example I understand the ring itself is not disturbed, and the bonds broken are hydrogen bonds rather than covalent bonds. Another interesting and counterintuitive property is found in sulphur produced by the desulphurization process of the oil industry, which has hydrogen sulphide dissolved in it. The hydrogen sulphide caps the polymeric chains, so this sulphur does not become viscous like pure sulphur. But what is interesting is that when it cools and forms a more ordered structure of S8 rings, it expels the hydrogen sulphide. Thus it "boils" when the temperature is reduced! All the transformations mentioned here are reversible which I assume is what you are looking for. Unfortunately, these properties are due to the molecular nature of the substance, so as metals do not generally form molecules it would be much less likely to find such properties in a metal. That said, it is concievable that a zintl phase could have the properties you are looking for at some temperature range. These are compounds containing positively charged alkali metal ions and negatively charged ions consisting of clusters of silicon, tin or lead atoms. Being ionically bonded they are not conductive in the solid state. It is not out of the question that there could exist a zintl phase where heating to some (very high) temperature could cause the molecular negative ions to break down into a more disordered polymeric state. But the atoms in negative ions are not behaving like "metals" so to call this an "alloy" would be a bit of a stretch. <https://en.wikipedia.org/wiki/Zintl_phase> [Answer] I'm late to the party but I did find some info on [inverse melting in a Ti-Cr metal alloy](http://shodhganga.inflibnet.ac.in/bitstream/10603/58690/12/12_chapter%204.pdf). > > In inverse melting, a metastable supersaturated alloy transforms > polymorphously to the amorphous or undercooled liquid state. This > transformation is thus like melting, except that the resulting phase is the undercooled liquid or an amorphous phase near the glass temperature (Ts),as opposed to high temperature equilibrium melt. > > > It is found that upon spontaneous vitrification the hardness of the material increases by about 40% whereas the longitudinal sound velocity decreases by about 10% indicating an elastic softening. The mechanical properties of partially vitrified material were found to be independent of the amount of crystalline inclusions indicting that they are dominated by the amorphous > matrix. > > > The bad news: 1. This is not melting from solid to liquid, but rather going from a crystallized state to an amorphous one (think quartz to glass). Amorphous materials are often more malleable than crystalline ones, but they don't always "flow". 2. It happens at 600-800C However, it does bring up something interesting, which is the idea that in some cases an crystal phase could actually have MORE entropy than an amorphous one. This has also found to be the case for a [Zirconium Tungstenate alloy](https://www.researchgate.net/publication/243328268_Entropy_Increase_in_the_Amorphous-to-Crystalline_Phase_Transition_in_Zirconium_Tungstate) at high temperatures and pressures. I was skeptical, but that paper seems to end with a small glimmer of hope for you! > > Our findings point to an entire class of materials that should behave similarly to ZrW2O8 and constitute direct experimental evidence for an overall entropy increase in an amorphous-to-crystalline transition. > > > [Answer] If you're willing to accept a "certain point of view" answer: There's no such thing as a melting/freezing temperature. A substance changes state continuously, solid<->liquid<->gas. As temperature increases, the rate at which it changes from solid to liquid increases, while the rate of the reverse process decreases. At some point, given other things remain the same, the melting and freezing rates are the same, and we call that temperature the melting/freezing point for that material ***under that set of conditions***. That means, if the conditions change, you can, in fact have a substance remain liquid at a temperature lower than its melting point, or solid at temperatures above its freezing point, **provided that conditions are different**. This is far less likely than the liquid to gas change, as that is easy enough to achieve with pressure and concentration changes, but there is no reason why it's impossible. Alternately, consider that melting/freezing happens over a range of temperatures. Depending on how you define "melting" or "liquid", you could claim it to occur at various temperatures, not the conventional value. A metal that has just softened enough that you can make an impression with a knife could be declared a very viscous liquid. Similarly, a metal, just cooled enough to form a crystalline outer skin could be declared a solid. [Answer] Your "alloy" is suffused with nanobots or perhaps made almost entirely of nanobots. Thus, you can give it any properties you want, including one that makes it solid at higher temperatures and liquid at lower temperatures. You can even use the mechanics of another answer for one direction, such as driving liquids from a solution leaving behind the solids. In the case of the nanobots, they take the liquid within themselves or just help evaporate the liquid. In the reverse, they release the liquid or extract liquid from the air (or a combination of both). [Answer] In most cases, you've got a snowball's chance in the Sahara at midday of getting that to happen at conventional temperatures. Nature doesn't like it when people try to invert Physics. At the same time, a trick of Chemistry might get you what you want. Suppose you create an alloy molecule whose core was a fully (-)ionized semiconductor. The core would be surrounded by a shell made from the desired elements of your target alloy, neutrally charged. Since the whole molecule would have a net negative charge, a large mass of this molecule would tend to be liquid if not cooled sufficiently. Oddly, when heated to within a certain range (depending on the structure of the molecule) the semiconductors in the core would tend to release their excess electrons and make it possible for ionic bonds to form between the molecules. As long as the strength of those ionic bonds is enough to hold up against the heat applied, you'd get a solid while hot. It's a wierd molecule, probably expensive to fabricate, and doesn't actually exist, but it is theoretically possible. ]

[Question] [ During the era of the Soviet Union, Russia was a much scarier nation: The [Cold War](https://en.wikipedia.org/wiki/Cold_War), the [Cuban Missile Crisis](https://en.wikipedia.org/wiki/Cuban_Missile_Crisis), and the [Space Race](https://en.wikipedia.org/wiki/Space_Race). No one can deny these were major events in Russia's history. Let's say that for some reason, I want to prevent the collapse of the Soviet Union, how can I do it? What is the smallest change I can make to history to allow the continuation of the Soviet Union? There are only three constraints, 1. The change must be realistic, no mind control, no super weapon, etc. 2. The Soviet Union has to be able to remain a economic and military superpower through and including modern day 3. The change can occur no earlier than 1800 [Answer] Ultimately the demise of the Soviet Union can be attributed to economic failure. With enough treasure the collapse could have been averted. This is solved most simply through the discovery of abundant natural resources, like huge deposits of easily-accessible oil (instead of deep shale-oil) in Siberia, maybe along with precious metals. Basically, commodities that reasonably could have existed but were hidden or difficult to detect. The windfall might lead to an initial barrage of public and military spending, increasing the stability of the USSR and sweeping up the bloc countries in patriotic fervor. Further investment in infrastructure and science might occur, leading to the early development of genetically-engineered wheat and corn that are resistant to the conditions of the arctic and sub-arctic tundra. This permanently solves their food shortages and prevents the need to import crops, making the USSR more economically independent. A Soviet Renaissance occurs. Democratic western countries would want access to their cheap oil and Eastern Europeans especially would become envious of the rapidly increasing standard of living in the USSR, leading some to distance themselves from their western allies in favor of closer ties with the empire, resulting in NATO's influence and power diminishing somewhat. Now, imagine a rapid industrialization occurs whereby the USSR diverts a lot of the manufacturing sector that was growing in China and begins producing well-made, reverse-engineered western products at cheaper, government-subsidized prices (ignoring NATO-aligned countries' intellectual property rights), which creates steady employment for its citizens and brings in huge cash flow from capitalist markets. Eventually NATO would be dissolved, with most member countries resigning in order to gain access to the new Soviet commodities/markets and to protect their own IP. The cold war ends with communist influence expanding around the world and the Soviet Union growing stronger than ever. Eventually many smaller countries along their border will be willfully annexed and the empire will expand, creating prosperity as it goes. [Answer] You need a real historian to make sure these are really feasible, but let me put some ideas out there. Most of these suggestions are variations on a theme, which is: # Let the Soviet Union take over Western Europe Doing so adds a huge population, a huge industrial base and a huge educated population to the SU, and would give them a significant leg up in the Cold War. There are a number of ways you could do this: ## Delay D-Day by a year. This allows the SU the opportunity to capture much more of Europe than they did. having D-Day fail would have much the same effect. ## Cancel the Marshall Plan Europe was crippled in 1945. The Marshall Plan solidified Western Europe in the Western Allies camp. Having them ignore reconstruction, and have the Soviets step in instead. could easily have been enough to allow the Soviets to dominate Europe politically. ## Communist Revolution in Europe This wasn't as unlikely as we might think in the late forties. A substantial part of the population, with some justification, saw the Soviets as having born the brunt of opposing Hitler, and some thought of the war as being brought about by European leaders (who were also responsible for the Great Depression that had just ended). It would not have taken that much to have sparked a revolution. Cancelling the Marshall Plan would contribute to this. [Answer] # Prevent the [Sino-Soviet Split](https://en.wikipedia.org/wiki/Sino-Soviet_split) China was a great ally for the USSR, with its large amount of people, place on the UN Security Council, and communist regime. If you prevent the ideological drift between Mao and Stalin, the two red giants stay together and support one another. No split means no [Sino-American Rapprochement](https://en.wikipedia.org/wiki/Cold_War#Sino-American_rapprochement), no trade with America. Instead, China trades with the USSR, and the USSR adopts China's economic strategy. Both countries are able to transition into what China is today without giving America the benefit of cheap Chinese factories. [Answer] Don't do what Gorbachov did. All of his reforms were well intentional, but were probably responsible for the collapse of the Soviet Union. I suspect that a leader who was able to implement economic reforms without causing disruption and chaos could have left the Soviet Union a sound and prosperous nation. China's controlled move to a free market economy was probably inspired in large part by the lessons provided by the failed reforms that lead to the collapse of the Soviet Union. Replay that success in the context of the SU in the 80s and I bet you'd get good results. The great thing about speculative fiction is that you get to prevent a disaster by retroactively applying the lessons provided by the disaster itself. [Answer] Kill or otherwise get rid of Joseph Stalin. He pretty much hijacked the communist experiment from the start, shaping it to his own priorities. It's hard to predict how it would have been without him, but it certainly would be very different, and presumably much better. Genocide is always a bad idea economically, whatever you think of ethics. On the other hand, perhaps they would be far less scary. [Answer] If you read Soviet literature, e.g., science fiction from the decade following Stalin's death, it was full of hope. And it was genuine hope, not communist party propaganda. These hopes were eventually killed, suffocated perhaps is the better word, by the stagnation of the Brezhnev era. Instead of the stagnation, allow economic reforms in the 1960s in both the Soviet Union and its satellite states. Allow Hungary to go through with its 1968 New Economic Mechanism unimpeded. Reintroduce and strengthen the reforms of Lenin's New Economic Policy and insist on the satellite states following suit. Allow private enterprise, foreign investment, market forces and the free flow of capital. Tear down the stupid Berlin wall (or better yet, don't build it in the first place); a good economic policy is a much better way to retain manpower. In short, do what China did under Deng, and what the Soviet Union dared not do under Brezhnev, for fear of losing direct and complete control over the economy of the totalitarian state. With the human and economic resources available to the Soviet Union, it could have become an economic powerhouse by the 1980s, even as it maintained a one-party state and totalitarian control over the political sector. China's example shows as much. And the occasional political revolt could be put down with ease (see Tiananmen Square) when the people, by and large, are satisfied with your governance. The Prague Spring of 1968 might not even have happened. Solidarity would have been just a blip on the radar, if it even formed in the first place. Oh, and don't let Reagan bait you with Star Wars into a spending contest that you are destined to lose. And, of course it goes without saying, don't get suckered into the Afghanistan adventure. Don't waste the space program's resources on a shuttle just for prestige, when it was glaringly obvious already that the universal, economical "Space Transportation System" was anything but. But you know what... even with these rather bad political mistakes, the Soviet Union could have remained intact and more powerful than ever, if its septuagenarian leadership only had the courage to allow its economy to flourish. [Answer] **Delay or destroy the Manhattan project** Why did the USSR fail? They could not compete economically with the United States. After WWII the US reduced the size of its military and grew economically, while the USSR kept its military large. Despite an initial military advantage, the USSR and the Warsaw pact could not attack NATO, initially because the US had nukes and Russia lacked them, and later because both sides had enough nukes to destroy each other in the event of war. Behind this nuclear shield the US and NATO spent less on military initially and had large economic growth. They then had a larger economic base to compete in an arms race. The USSR had a weaker economy, couldn't scale up its military and collapsed under the economic reassure. If nuclear weapons took several decades longer to develop, the USSR would have been able to force a confrontation much earlier when it had a military advantage. This would either force NATO to spend more on military and reduce their economic advantage or allow the USSR to take over or invade much of Europe, giving the USSR a large Economic base to compete from later. [Answer] This is the question Francis Spufford addresses in *Red Plenty*. To summarize, the Stalinist economic system, in which the second-most-powerful man in the Soviet Union ended up having to adjudicate disputes between two turnip farmers, was hopeless and inefficient. At the time, though, some theorists did propose a better solution, what we today call optimization by linear programming. There were two problems with it: there wasn’t enough computing power in the Soviet Union in the middle of last century to make it work, and it kept telling the central planners that the way to run an economy efficiently looked an awful lot like capitalism. For example, it kept calculating “shadow prices” that functioned a lot more like market prices (plus some Pigovian taxes and subsidies) than like the Marxist labor theory of value. The example of successful economic reform of a Stalinist economy in the real world while keeping the Communist party in power is of course China under Deng Xiaoping. If there’s an actual time machine involved, you can deliver blueprints for future technology. But, no matter what you do, you have to break the stranglehold of Stalinist ideology over the Soviet economy. [Answer] ## Don't ban cybernetics There were attempts to build centralised controlling system that would optimize everything. However, for ideological/political reasons cybernetics were outlawed. With better computers (as a result of actual research in the field) and **less political/ideological grip on science** (you would need that one to save the field anyway) it would make economy actually **work** without market (although in many ways, good and bad, similar to having one). While you are at it, you can probably do the same thing with genetics (stop Lysenkoism). If you have an actual winter, you'd better know your way around making cold-resistant crops. Well, if de-politisation of science would not fly, you can pick some other research fields (process is kinda random anyway) for SU to outlaw and keep cybernetics afloat. ## Purge party higher-ups When *average* age of top party members is 70 - well, something went terribly wrong and people are being selected not for management capabilities but for stuff like personal familiarity and being convenient. This process should be disrupted - or maybe you could have "inner party" that actually decides what happens and is not slipping into senility. Either way, thouroughly centralised system without proper control from the center is bound to go haywire, so your party better know what they are doing and actually do stuff. [Answer] Refortify the multi-national conception of the USSR. Think about the name of the country and the aspiration it was intended to convey: Union of Soviet Socialist **Republics**. Gorbachev's perestroika and glasnost were reasonably well thought out concepts about how to begin reforming and modernizing the economy, but his highly technocratic worldview didn't account for the natural human desire to feel included. His Politburo was apparently the most ethnically Russian in all of Soviet history. This indicates that talented people in the other Republics weren't getting as many opportunities to build career stakes with the central government. Keep in mind that the Romans had been relatively good at recruiting talent into their leadership circles from all regions of their empire as it expanded. Gorbachev wasn't outwardly nativist, but we see a lot of that among Putin's inner circle... and attitude that's exacerbated tensions with the former Republics [Answer] There are several factors that caused the Soviet Union to collapse. For now, I can only write about two. Preventing either one of them may have allowed the USSR to survive into today. **1. Soviet Paranoia** Some will say that this is cultural (I do not care to categorize it), but it is probably the most significant factor explaining why the Soviet Union collapsed. There was a great deal of internal paranoia--ie, a fear stemming from Kremlin members, high officials, intelligence personnel, or military figures just ending up missing or disappearing. This was so controversial, that there was a method of detecting whether or not an official was still around, and it involved ballet performances: If someone was supposed to watch the ballet but was not photographed at the event, it was generally assumed that they were silently executed. But this problem extended beyond internal paranoia, one of the biggest mistakes the Soviets made before their fall was a propaganda campaign to discredit the leadership of a communist faction in Afghanistan. That faction was known as the "Khalqists" and was headed by Hafizullah Amin--and unlike the other communists, they advocated immediate reforms to take the whole of Afghanistan from a traditional society into a secular, even atheist, and communist one. However, those reforms were met by a backlash from the conservative/traditional segments of Afghan society, which caused chaos. In order to distance themselves, the Soviets unleashed a propaganda campaign to discredit the Khalqists and frame Amin as a secret CIA agent, bent on sabotaging communism in Kabul. The aim was to convince the Afghans that the Khalqists were not true communists, so that other, more moderate communist factions can appear more palatable to all segments of Afghan society. The problem? The Soviets began to believe their own lies. Amin was treated as a CIA agent by the Soviet press, and numerous Soviet attempts to assassinate him failed. So, an opinion that "someone" must be helping Amin began to formulate--naturally, it was assumed to be the Americans. Moreover, the Khalqists, fearing that their time had come, began to make all sorts of political mistakes, overreacting to protests and committing crimes that began to alienate even the left-wing segments of Afghan society. The Soviets felt they had to act fast to preserve communism in Kabul--or else, a government favorable to Washington might be created in Afghanistan. The result? The Soviets invaded Afghanistan in panic, unprepared and without a clear objective. Today, in many political science classes, this scenario is studied to show the problems of "blowback"--which occurs when actors inject statements that may be false in order to discredit opponents or alter the opinion of certain populations. Sometimes, those statements come back seeming more real than their author(s) ever intended, and that can cause great panic--even amongst well-calculated Soviet intelligence agents. The Soviet invasion of Afghanistan is considered by many to be its downfall, or at least, the beginning of its downfall. Still want the USSR around? Build a time machine, tell them Amin was probably just politically stupid, convince them not to panic and invade Afghanistan, and that if they do invade Afghanistan on the day that they ultimately did, that Zbignew Brzezinski predicted it at least a week ago--and that the CIA is hellbent on getting revenge for what the Soviets did in Vietnam. **2. The Cold War and American Covert Action** Nowadays, no one denies the lengthy covert war between Washington and Moscow. During the Korean War, Russian pilots flew in Korean-marked jets, and even though the Soviets were not one of the primary belligerents in that war, the top ace fighter pilot was a Russian. Later, the Soviets aided the Vietcong during the Vietnam war. This was supposed to be secret, because when interviewed their officials would say, "What? I have no idea what you're talking about."--plausible deniability. But Washington also had a hand in clandestine activities against Moscow. The biggest and most famous one was Afghanistan, however, the real success of American influence was not only arming and training organizations to fight the Soviets, it was to convince numerous populations that the Soviets were "evil, Godless commies", while at the same time, the U.S. had a program to show American movies to foreign audiences, and Disneyland was so big, that imprisoned Eastern European dissidents occupied by the USSR or under communist rule, would look outside their jail-cell windows and say "Disneyland"--associating Disneyland with freedom. As a result, many countries that were supposed to be behind the "iron curtain", were actually behind a very fragile glass wall--with resistance fighters within them (or at least political movements) that opposed the USSR. So, while the U.S. could count on the other four members of the "Five Eyes"--United Kingdom, Canada, Australia, and New Zealand, and often even count on other NATO countries, the USSR had a dwindling number of allies--even outright communist countries, like China and Tito's Yugoslavia, at times during the Cold War, were on the side of Washington. Furthermore, the Arabian Peninsula and Saudi Arabia were squarely in the hands of American and British oil companies, and up until 1979, even Iran was an American ally and used to contain the USSR, which effectively meant the entire oil of the Middle East was in the hands of Washington and NATO. Political scientists call this "balancing"--Washington did it much better than the Soviets, arguably because the U.S. was in a much better position after WW2 than the USSR, and so could offer more to its allies, but also because American covert action was based in compellence to force certain outcomes: Latin American countries have socialistic leaders like Allende in Chile, who may favor Moscow? Devastate their economy, rouse their public, then overthrow the regime in favor of a dictator who is more favorable to Washington--like Pinochet. As a result, governments across the world, but especially in Latin America and the Middle East, were under unshakable political instability (economic sabotage, regime change, civil war, etc) because of these covert action operations. Still want the Soviet Union around? Use that same time machine to tell them to preserve their spheres of influence, so that they do not fall like a column of dominoes. That way, at a minimum, the USSR can avoid being contained (and more or less isolated) from the rest of the world. Also, tell them that American realists and pragmatists do not see the Cold War as solely a war of ideology, but a war based in geopolitics. Sure enough, the Soviets were not all idealists either, which meant the fact that the U.S. and the USSR were the two most powerful countries, is sufficient for some of their countrymen to be distrustful of the other--or at the very least, very cautious of the other, and for some, like George Kennan, that is enough reason to want to put pressure on the other. Kennan's containment policies combined with the Marshall Plan and covert action worked to turn the world in America's favor. [Answer] During the 80s, the Soviet Union attempted to match defense spending with the United States. Since their economy was only a quarter the size of the United States' economy by GDP, this required them to dedicate four times as much of their economy to the military. The US was allocating roughly 6% of their GDP to the military. The Soviet Union was around 25%. If the Soviet Union had instead spent 5% of GDP on the military, this still would have been high by modern standards. The US is currently one of the higher spenders at 4.5% in 2015. That would have left 20% of GDP to use on civic improvements, research, and other expenses to improve the economy. By not matching the Reagan buildup, the Soviet Union might have been fiscally sound. Note that this would have required abandoning the communists in Afghanistan. Ideally you'd avoid the 1979 invasion and start the military drawdown then instead. Lower defense spending would also have made it easier to sign treaties with other countries. What if the Soviet Union had been trading with western Europe in the 80s? Lower defense spending might also have prevented Chernobyl. There is some speculation that the Chernobyl reactor accident was caused by defense testing. Of course, I can't confirm that. It's speculation. But it is plausible enough for story purposes. I suppose the counter-claim would be that the Soviet Union needed that military spending to stay together. I don't know enough to debunk or confirm that. I suspect that eastern Europe might have broken off in that scenario. Also, presumably they'd spend less on foreign aid to countries like Cuba as well. [Answer] Prevent the "accident" ("disaster" is a better fit) at the Chernobyl Nuclear Power Plant. It alone pretty much bankrupted the Soviet Union. The accident also cost the Soviet Union lots of prestige abroad... including in East Block... some even at home, although they were able to downplay it. No Gorbachov - replace him with hard-liner. Ideally, a "young" hardliner... could even follow Brezhnev in 1982; to prevent the less than ideal situation with four different leaders in less than five years! Alternatively, let [the coup against Gorbachov in 1991 succeed](https://en.wikipedia.org/wiki/1991_Soviet_coup_d%27%C3%A9tat_attempt) - and perhaps arrest/kill/marginalize Boris Yeltsin (long?) before or in the beginning of the coup (much of Yeltsin's power came from his roles as leader in Moscow and "President of Russia" (while it was part of the Soviet Union) - this could've been stopped). Stop Lech Wałęsa - and the Solidarity Union - in Poland. Be firmer in East Berlin - prevent The Berlin Wall from falling. Be firmer in East Germany - support STASI, prevent more escapees. Prevent Ronald Reagan (or George Bush Sr.) from becoming President of the USA - or take him/them out in some way (remember Hinckley nearly succeeded - and he just wanted to impress Jodi Foster!). Ideally let Jimmy Carter have a second term, but few could've been worse to the Soviet Union than Reagan. [Answer] Many answers here suggest that economics is the primary factor: specifically the lack of a liberal economic model, but this fails to explain the fate of other regimes. I suggest we take a step back and try and understand how the world works outside of liberal democracies; as it seems that many are answering through the bias of their own cultural expectations rather than the historical realities. I dare say it's convenient that we in the west take such an essentialist view that, of course, those societies which are not like us must fail because they are not like us. If the answer is that the USSR failed economically, why did it not collapse with Stalin's woeful famine-causing mismanagement? Why did China's regime not fail under Mao's similar incompetence? Why are impoverished North Korea and hyperinflation ridden Zimbabwe still around? They began life as socialist states and yet are amongst the most hopelessly corrupt and poor in the world. If economics was the be all and end all they all would have collapsed long ago. The real issue is the enforcement (or loss) of authority. Gorbachev's Glasnost reforms were the long term consequence, effectively, of de-Stalinisation. The USSR under Stalin is more similar to contemporary North Korea; in which the personality cult of the dear leader, and his control over society, is absolute. Non conformity is not tolerated. Stalin was responsible for atrocities, from the Katyn massacre in Poland to the Holodomor in Ukraine and the mass murder and imprisonment of just about anyone who was intelligent or stupid enough to say something questionable. This is similar to Mao's Cultural Revolution, or to a lesser extent Khmer Rouge's genocide (and that was stopped only by an invading Vietnamese army). Simply make sure de-Stalinisation never happens. The leaders of the Soviet Union after Stalin's death were just as brutal. Stalin's 1924 Socialism in One Country proposal is adopted wholesale, in so far as it allows leaders to compartmentalise each Soviet/Warsaw republic to ensure greater control over institutions and considerably less flow of information and people between places. Incidentally, I've read a few books written under the pseudonym Viktor Suvorov, by a Soviet army intelligence officer who defected in the 70s. He said that the only people who knew a proper comparison between west and east were his peers, and consequently they never understood why any westerners would be sympathetic to the USSR. Importantly, he argued that prior to his leaving the entire Soviet economy was designed to supply the Red Army, nothing else was a priority (in this case traditional liberal economic concerns are irrelevant), and Soviet industry was fed technology by the USSR's spies who stole practically everything they could from the west. This meant that the USSR's military capability leeched off western military capability. Innovation wasn't necessary, just repurposing. So if the strategy is to make the economy serve the military, whether it makes the people wealthier or not is irrelevant. And how would they know any better with a press in perpetual Stalinism? Because we're all free comrades here who have better living standards than anywhere. Wink wink. Industry's purpose is to support state organs responsible for enforcing control. It doesn't need to do better than anyone else, simply provide a minimum output. Unfortunately this means the USSR won't be able to remain a super power longer term, but then it can't anyway because America has the technology lead by having free speech and thus free exchange of information. More information shared, more new ideas, more research. This however isn't to say that the USSR will be an irrelevance... I mean, we're talking about something like a giant North Korea. If the USSR remained Stalinist nuclear disarmaments with the USA would never have happened. They would be swimming with nuclear weapons and even if their traditional army is a step behind, or becomes completely irrelevant, they still have the power to bring on a nuclear apocalypse on a whim. Not insignificant. **The Soviet Union can't have free exchange of ideas and survive. You're going to have to pick one. That is precisely why they invaded Czechoslovakia in 1968, even though it was late in the year and they needed to deploy the army to help collect the harvest (thus risked famine) - the free press is more dangerous to the USSR than famine. So they put down "Socialism with a Human face" with tanks. When Gorbachev was asked what was the difference between Glasnost and then, he said "Nineteen years". That is the problem.** [Answer] I do believe that the [Red Alert](https://en.wikipedia.org/wiki/Command_%26_Conquer:_Red_Alert_(series)#Plot) series has your answer, although it's pretty intentionally outlandish. Tl;Dr: Kill Hitler AND Einstein. (I would have put this in a comment, but my rep isn't high enough.) [Answer] No Gorbachev or Perestroika, that's it. If you want details, you even can keep Gorbachev but get rid of Yakovlev, and, desirably, Suslov. [Answer] I would have the US invade Iran at the time USSR were in Afghanistan. That could have shifted the military attention in the region towards the US and the soviets could have supplied the iranian freedom fighters with weapons in exchange for help against the Mujahedin (cutting off supply routes). The effect would be higher oil prices to bolster the soviet exports, the losses of men and equipment in Afghanistan would be far lower. When the US eventually had to give up their presence in Iran a soviet withdrawal from Afghanistan could be part of a peace deal for the region. This would leave the Soviet Union a far stronger military power with a far better economy than was the result after the withdrawal from Afghanistan in real life. If the middle-east oil production was set back as well the soviet economy could be booming for a decade. And the US might withdraw itself into isolationism. [Answer] **John Hinckley Jr's 1981 attempted assassination of Ronald Reagan succeeds** In my opinion, the actions of Ronald Reagan during his presidency can't be understated in bringing about the end of the Soviet Union. Prior to his election, the policy between the two superpowers was one of peaceful coexistence, Reagan was the figurehead of a conservative movement that saw the presence of the USSR as an intolerable evil. So, in the seconds after Hinckley's bullets fatally wound President Reagan, a sharp-shooting secret serviceman fires a killing shot straight into Hinckley's head. With the assassin dead, his bizarre motivations (wanting to impress the actress Jodie Foster) never come to light. America is in shock, and people are speculating wildly about the motives of the assassin, was he a communist, an Islamist, a neo-nazi? Regardless, the consensus in Washington is that something needs to be done about gun control. Comprehensive reform of gun law is passed, and with it, the conservative movement that Reagan figureheaded is sidelined. The "Evil Empire" speech never happens and the policy of peaceful coexistence is maintained. The 80s in this timeline are much less "80s-y", the "big bang" of financial de-regulation is less radical and the economic malaise of the 70s persists for longer. Crucially, the arms race between the two blocs is less extreme, and the USSR is able to invest less in its military, and more in modernising technology and consumer goods. By the present day, it's hardly a socialist utopia, but it successfully manages to plod along. [Answer] Gorbachev respects the will of the people of the USSR as expressed in the March 1991 referendum when 76.4% of them [voted to retain](https://en.wikipedia.org/wiki/Dissolution_of_the_Soviet_Union#Moscow.E2.80.99s_crisis) the USSR. Alternatively, [August 1991 Coup](https://en.wikipedia.org/wiki/1991_Soviet_coup_d%27%C3%A9tat_attempt) against Gorbachev succeeds thereby preventing Gorbachev from proceeding with the dissolution. [Answer] Make Churchill it's a good idea to implement parts of [Operation Unthinkable](https://en.wikipedia.org/wiki/Operation_Unthinkable). (USA don't want to take part of this but can't stop this from happining). Possible end results: ALL of Europe is under Soviet occupation. USSR was not involved in helping to destroy Japan army in China and started covert trade with Japan instead. Japan have their own Manhattan project and now has time to finish it and actually use several bombs. America responds in kind. Japan responds with biowarfare. Nuclear attacks by USA don't have too much effect on japonese morale so USA must actually invade and take heavy losses both in body count and in time. USSR gets nuclear weapons faster because Japan is willing to help (for a price). Churchill is killed in the end. (Wikipedia of this timeline says he was killed by fanatic and it's conspiracy theory to think that there was any involvement from $country\_name secret services). [Answer] The Soviets could have stopped their deep well drilling plans and instead gotten a head start on drilling for oil and gas sooner. They are like 50 years behind. More oil money would have meant more power and economic ability to stay alive. As with China, the ability to convert domestic resources to Dollars and UK Pounds means prosperity. And the economics would have softened the commie stance to a lot of degree (like in China). But the Venezuela model needs to be considered. Don't just be rich in oil. The other consideration would be to keep Stalin from killing all of their scientists. Talk about stupid on that. The scaremongering was too intense for too long. [Answer] My short answer would be: No drastic purges of the education or scientific communities. Pick one of the following: Nuclear weapon delivery systems, or the moon race, the USSR under its own self imposed restraints does not have the flexibility to go for both. Keep your people at a reasonable level of happiness. Crack down on political corruption and be completely open about it. Nothing incites rebellion more than people being oppressed while their government even SEEMS to not care about corruption. [Answer] # Prevent the Great Purge of 1936-1938 This single event absolutely gutted the Soviet Union. It removed great leaders, thinkers and builders. It cowed those who remained into underperforming and being silent, so as not to be noticed. It set back science and culture and infrastructure by 20 years. At least. With better leaders, with an agriculture that functioned, the Soviet Union would have much better resisted Germany's offensive. This, in turn, would have led to a much lesser degree of military and political radicalization of the USSR. Quite likely, the entire cold war with the US would not have happened. Instead, there would have been fierce competition to show whose country and whose ideology was better, but in economic and cultural and technological "battlegrounds", instead of the purely military mode of the cold war. In simple, the USSR would have been a functional country instead of the huge military camp it became. So how does one prevent the Great Purge? Just get Stalin a friend. A confidant, someone who he likes, but also trusts. And who is an intellectual. Just that slight nudge to turn Stalin's paranoia away from his own country's achievers, and towards actually achieving progress. Maybe someone that saved him from being run over and crippled at age 12? NA, too early, that would prevent his political career. Maybe a friend from the illicit book club at the seminary? This would provide a person with aligned political views, yet of an intellectual background, that could accompany him further in his career? Just a small influence, to turn Stalin's energy away from fear of the other achievers in the Soviet Union. [Answer] The eastern block was run on fear and paranoia. The Soviet union and all their protectorates were sentenced to fail from the start. On the both sides of the Iron Fence it was a race where the strongest wins and weaker lose. In the Western side strength was measued by net income and/or election results. This setup advantages the agile minds and inventors. To be succesfull, one had to grow faster. In the Eastern side the strength was measured by ability to bump the opponent off. This system advantages spineless paranoids. To be succesfull, one need to eliminate opponents faster/more thoroughly. --- How the Soviet Union could be saved from the doom? The only way was that US and OECD failed first. If the project Apollo was fail and the whole Space Race would have lead to the economic disaster giving Soviets domination in near Space. If the Chernobyl disaster would happen in Three Mile Island and Chappelcross (Core meltdown and explosion) instead. I think that in this scenario, the Soviet Union would take over whole world but its structure and system would lead, sooner or later, to decomposition and tough fight between different factions. [Answer] Protests that are relentless and involve most of the populous take away the leaders power, instead a functional more decentralized government is established where none has a huge amount of power. Also make the system more functional and dependent on the needs of the people by measuring demand and adjusting production with a formula to maximize happiness. No surveillance, the state becomes transparent and open for anyone to participate and look at. Corruption is severely punished and prosecuted by temporary task forces formed from random normal citizens, similar to jury duty in America, this creates an incorruptible instance that controls the government at every level. [Answer] Continue the Space Race using nuclear propulsion and establish lunar colony as exclusive economic zone. If USSR is able to build and sustain lunar colony, attracting the best and brightest people there (instead of DARPA-funded projects) and give them more autonomy than the system back on the earth allows, perhaps it could allow USSR to maintain technological lead and national cohesion. It would require Stalin to be deposed in favor of competent technocratic manager, perhaps Kurchatov? [Answer] [Multiple factors led to the collapse of the USSR](https://www.britannica.com/story/why-did-the-soviet-union-collapse) and if you could prevent most of them, you could keep it afloat longer than in our timeline. You would have to prevent: * Focus on alternative energy. Oil and natural gas were important to the USSR's command economy. The economy was damaged when then the value of oil went from 120 US Dollars a barrel in 1980 to 24 US Dollars a barrel in 1986. Have to USSR turn to some alternate energy sources like wind energy (which has been around since 1888 when Charles F. Brush invented the world's [first automatically operated wind turbine](https://en.wikipedia.org/wiki/Special:BookSources/9780806128122)), hydroelectricity (which would have been available at the time), and [syngas](https://en.wikipedia.org/wiki/Syngas) (used during World War II to help power cars when gasoline was low). These alternative energy sources could help make the USSR less dependent on oil energy-wise and economy-wise since they could sell the energy to other socialist states. You don't need to get rid of oil, but make the USSR more independent from oil until the oil prices go back up in 1990. * Reduce military spending, which took up 10% to 20% of the USSR's resources even when its economy was stagnant. * Avoid the Chernobyl Power Plant disaster in April 26, 1986 with better trained technicians, more state of the art power plant than the one used in Chernobyl, or - as I described in point one - have a stronger move to alternative energy so people are less dependent on plants like Chernobyl. * Don't go to Afghanistan! It is called the ["Graveyard of Empires"](https://www.nytimes.com/2017/08/29/world/asia/afghanistan-graveyard-empires-historical-pictures.html#:%7E:text=Afghanistan%20has%20long%20been%20called,who%20coined%20that%20disputable%20term.&text=In%20the%2019th%20century%20there,forbidding%20deserts%20and%20mountain%20ranges.) for a reason. Stay away, or just send a very small force to scare America into mobilizing and getting themselves trapped there instead of your own forces. * Reduce Gorbachev's reforms and don't have him dissolve the USSR. [76.4% of the people in 1991](https://web.archive.org/web/20140330025028/http://soviethistory.org/index.php?page=subject&SubjectID=1991march&Year=1991&Theme=4e6174696f6e616c6974696573&navi=byTheme), even after being exposed to Western markets in a limited degree, wanted to retain the USSR with some reforms according to a [Union-wide referendum](https://en.wikipedia.org/wiki/Dissolution_of_the_Soviet_Union#Moscow.E2.80.99s_crisis). There should be fewer reforms and with the help of these steps, people should feel less of a need to reform, at least so rapidly. * Oleg Guimaoutdinov was a USSR computer scientist who had the idea for [a Soviet internet to supercharge the state's socialist command economy](https://www.bbc.com/future/article/20161026-why-the-forgotten-soviet-internet-was-doomed-from-the-start#:%7E:text=The%20Soviet%20internet%20was%20the,the%20USSR%20back%20in%201959.). He made a detailed proposal in 1970, but Communist Party leaders went against the idea. They allowed his ally Viktor Glushkov to [create a small network called OGAS](https://aeon.co/essays/how-the-soviets-invented-the-internet-and-why-it-didn-t-work) that began in 1962, but it was cut in 1970. In your timeline, get the leaders to agree to this project. This could reduce inefficiencies and quickly tell people how many resources needed to be sent to different locations using technology. It could help exchange important data under the watchful eye of the state. It could also be somewhat available to civilians, which would help make Marxist socialism and the idea of the dictatorship of the proletariat defined in Karl Marx's Critique of the Gotha Program look more appealing technology-wise than capitalism. After all, the first global civilian internet network would be created by Soviet socialists, not by the capitalist west. The USSR would also go down in history as inventing the internet if this system was created from expanding the pre-existing OGAS system. [Answer] At the [Second Congress of the Russian Social Democratic Labour Party](https://en.wikipedia.org/wiki/2nd_Congress_of_the_RSDLP) in 1903, someone talks five representatives of the General Jewish Labour Bund from walking out of the proceedings. As a result, the faction commanded by Lenin, after losing a vote on certain membership issues, comes to be known as the [Mensheviks](https://en.wikipedia.org/wiki/Mensheviks) - the *minority*. Over time, less authoritarian elements (called the *Bolsheviks*), by virtue of being thought of as the Majority, gain a slow but steady edge in shaping public opinion. Eventually they create a Soviet Union that is characterized by its decentralization and respect for the local councils ("soviets") that make decisions in accord with popular consensus and a respect for human rights. (This movement later inspires the German patriots who handily put down the machinations of disaffected elements working under the direction of an army infiltrator called Adolf something-or-other) ]

[Question] [ The obvious WWII alternate history question is [how could the Axis have won](https://worldbuilding.stackexchange.com/questions/30758/what-single-change-would-have-given-the-best-chance-for-the-axis-to-win-world-wa). Let's try something different this time. The [Battle of France](https://en.wikipedia.org/wiki/Battle_of_France) was a big gamble for the Third Reich. They sent more or less their entire army in a rush attack in order to secure a fast victory. You may be reminded of the [Schlieffen Plan](https://en.wikipedia.org/wiki/Schlieffen_Plan) in WWI. It worked this time, but had it not, they would have been in a dire situation. Had their army been destroyed, there would not have been enough left to defend German territory. Had they been forced into a more static war of attrition, France and Britain would have had time to reorganise their military, with the support of their respective colonial empires and access to American industry - and the Axis may have not been in a better position to fight a new WWI than the Central Powers had been. So be it with a swift counter-attack or a slow, bloody grind, what is the smallest change that could have resulted in an eventual Allied victory in the Battle of France? The customary disclaimers apply: * It doesn't have to result in a global Allied victory with the fall of Berlin and Rome, but it has to significantly increase its probability. * A victory doesn't mean the entire Axis is defeated, only the European part. Japan can be victorious in the Pacific Ocean at the same time, for example. * The change has to be a single event, or a collection of tightly coupled and interdependent events, ideally the starting point an otherwise trivial change. It has to happen either during the war, or not more than a few years before it. The war should, at least in the beginning, look very similar to what happened in real life: the alliances should be roughly the same, the events like the Anschluss, the conquest of Poland, the attack against France and the Low Countries should occur (or at least begin), even if at different dates or different order. The major participants should be the same. * The change should have a realistic justification (so no secret Belgian superlaser), no unrealistic decision like continuing the very expensive Maginot Line until the sea without a very solid reason, no sudden change of doctrine just because some general had an epiphany about revolutionary new tactics... [Answer] ## The French listen to Belgian intelligence. The Belgians had surprisingly good intelligence about what the Germans were planning. They'd identified the German military buildup, and considered an invasion through the Ardennes to be the most likely course of action. The French command didn't react to these warnings, since they still suspected that an invasion through the Ardennes would be slow and difficult. If the French command had instead reinforced the area, specifically with more anti-tank and anti-aircraft forces, they would've been in place for the German attack and could probably have held the position, especially since they had support from the Belgians in the area. In reality, the Belgians were overrun and the local French forces weren't equipped to deal with the number of tanks and aircraft they encountered. The Belgians retreated and then the French positions were overrun. If they'd effectively re-deployed forces to the area, the French could've counted on having numerically superior forces of heavier tanks than the German army. They'd also have a terrain advantage, fighting against German forces as they tried to emerge from the forest, rather than in an open position where the speed of the German tanks could be effectively used. Basically, if the French had effectively countered the German armored divisions with their own, they could've won. Instead, their tanks were scattered thin across the Maginot line, which wasn't attacked, and had basically no impact on the battle. [Answer] If you don't mind the change being natural rather than human based, have it rain for a few days after the initial attack. A good hard rainstorm for even two days would have kept the Luftewaffe from being nearly as effective, as they'd have less visibility and less obvious targets. It would also make take off and landing harder as many of the airfields were pressed earth or grass, if it got too wet they wouldn't be able to take off at all. Rain would also slow down and wear out the soldiers as they march through mud in soaking wet clothes and packs. This in turn would slow down the tanks and armoured cars of the German army. Supplies wouldn't reach the front nearly as quickly further slowing them down. Having a day or two to recover from the initial attack, would have given the French and English critical time to build up some defenses, regain control of units, and start using some of the soldiers on the Maginot Line as reinforcements. It would still be a close thing, but with the Germans generally inferior weapons, and limited supply of advanced tanks and planes, they had to rely on speed and keeping the French and English off balance. Considering the time of year rain is not uncommon, and rainstorms could last from a few hours to several days at a time. So having intermittent rainstorms of a few hours each over a week or two in northern and central France would hamper the German army fairly significantly without requiring a handwave. [Answer] The simplest change I can think of would be if the German army commanders had followed orders and stopped their advances as directed by central command. Multiple times during the drive into France generals Rommel and Guderian encountered little to no resistance and advanced significantly farther than they were ordered to. They even went so far as to disobey stop orders, by moving their forces in so called "reconnaissance in force". These massive advances allowed them to attack the Maginot line from behind, causing confusion among the French forces, and meant that German forces were already occupying areas that the French army was trying to use to assemble for planned counterattacks. Hitler's best military victories came when his directives were ignored. If the Nazi leadership had a tighter control on the German officers early in the war, and their orders were followed more closely, they would have lost out on many of the opportunities that the local commanders exploited. If the German forces had stopped as ordered the French and British could have more easily moved their forces into place for a better defense and counter attack. [Answer] As a single change...give Charles de Gaulle more influence over France in the early 1930's. Charles de Gaulle was a strong opponent of the Maginot mentality (potential he coined the term Maginot mentality) saying trench warfare would soon be obsolete and France's downfall would be because of it's dependency on these lines. In his book "Toward a Professional Army", de Gaulle outlined what he described as the new warfare > > He proposed mechanization of the infantry, with stress on an élite force of 100,000 men and 3,000 tanks. Ironically, German panzer units, so effectively employed in the invasion of France in 1940, used similar theories, while the French dispersed and wasted their armour. The book imagined tanks driving around the country like cavalry. De Gaulle's mentor Emile Mayer was somewhat more prophetic than he about the future importance of air power on the battlefield. Such an army would both compensate for France's population shortage, and be an efficient tool to enforce international law, particularly the Treaty of Versailles, which forbade Germany from rearming. He also thought it would be a precursor to a deeper national reorganisation, and wrote that "a master has to make his appearance...whose orders cannot be challenged – a man upheld by public opinion".[42] > > > Oddly, he very much outlined the tactics that would be used against France to conquer it...a little prophetic? Had France adopted to de Gualle's tactics earlier, they would have possessed the mobile force required to relocate and halt the Germans breach of the French defensive lines much more effectively. The key portion of this tactic is how the tanks were dispersed...ultimately the French dispersed their tanks relatively evenly along the line, when a mobile force of tanks would have been far more effective against the German invasion. [Answer] The actual answer is "pay attention". British military theorists like [B. H. Liddell Hart](https://infogalactic.com/info/B._H._Liddell_Hart) and [JFC Fuller](https://infogalactic.com/info/J._F._C._Fuller) had pretty much envisioned the elements of modern armoured and mechanized warfare in the closing days of WWI. "[Plan 1919](https://infogalactic.com/info/Plan_1919)" was the conceptual means of defeating the Germans in a massive mechanized offensive in spring/summer 1919 using combined arms teams of tanks, "contact patrol" fighters to provide overhead cover and ground attack, and rapidly moving infantry and artillery to break through at selected points, exploit the breach and envelop the rear area. A draft of Plan 1919 can be read [here](http://www.alternatewars.com/WW1/Fuller_1919.htm) Sounds very familiar, right? The British government even went to the extent of creating an experimental mechanized brigade and conducting a series of war-games and manoeuvres during the 1920's to test and refine these ideas. Given the technology of the time and financial constraints, the brigade was disbanded and shelved, but detailed reporting was available, and eagerly consumed by such luminaries as [Heinz Guderian](https://infogalactic.com/info/Heinz_Guderian), [Mikhail Tukhachevsky](https://infogalactic.com/info/Mikhail_Tukhachevsky) and [Charles de Gaulle](https://infogalactic.com/info/Charles_de_Gaulle), and implemented by the German Army and (until the purges) the Red Army as well. If the British Army had persevered with their experimentation of armoured and mechanized forces, even in the face of government indifference or cost cutting (for example, the Army could have chosen to close out other units, or do other cost cutting measures), they could either have had an integrated combined arms force of their own to oppose the German Panzers, or at least had corporate knowledge and been familiarized by constant training in how to defend against armoured and mechanized forces. The example of the British would likely have had an effect on the French General Staff, and they might have adopted a more comprehensive combined arms approach to warfare as well. It is often overlooked that the French actually had more tanks than the Germans at the start of WWII, and in many respects, French tanks were superior to their German counterparts (although the crew arrangements of French tanks were a serious weakness). Familiarization with British practice would have impressed the need for better crew communications and tank layout on the French, as well as preventing the French from dispersing their tank forces in "penny packets" among Infantry formations. (In the real timeline, the British and forgotten many of the lessons of the 1920 era experimental brigade, and also designed tanks to be dispersed among the Infantry). Large numbers of more and better French tanks combined with an *effective* doctrine for their use would have seriously complicated German planning and operations, and an effective British mechanized force operating in the Western flank probably would have persuaded the Germans that their plan was not viable. So in the end, what stopped the British and French from winning the battles and the campaign in 1940 was forgetting or ignoring the hard learned lessons of WWI and the lessons of the experimental armoured Brigade in the 1920's. [Answer] This is a nice breath of fresh air, usually we tend to focus on how nazi-Germany could've won the air. Now, you're correct that the German plan to invade France and the low countries was by no means guaranteed. It was deemed too risky by most of the German high command and in fact was not the original plan the German military had in mind (whether the [Mechelen incident](https://en.wikipedia.org/wiki/Mechelen_incident#Initial_German_reaction) influenced the change to the more risky thrust through the Ardennes is disputed). Even with outdated tactics and doctrine, the Allies still had a good chance of defeating the German attack. Their tanks were of better quality (though dispersed) and they had more manpower. Only the luftwaffe held the upper hand over their Allied counterparts - this military arm would prove vital during the battle of France. **the battle of Sedan goes more poorly for the Germans** Capturing Sedan and the bridges was a vital part of the German plan and this was where the main thrust would take place. Strategic success or defeat depended on the critical battle of Sedan. The French defenders they faced were mostly of poor quality (the best divisions had been sent to Belgium). Still, if things had gone slightly differently, the French could have delayed or perhaps even stalled the German advance, allowing strategic reserves to be pulled back from Belgium. The panic of Bulson (in which elements of 55th division fled because of a false report that claimed German tanks had already penetrated to as far as Bulson) was one such avoidable event. Or perhaps the aircraft that the British & French threw at the bridges over the Meuse river (where Luftwaffe fighters were swarming in enormous numbers) could have scored a chance hit, blowing up vital bridges and delaying the German advance. If the Allies had gained more time, they could have consolidated their defences and perhaps avoid encirclement and destruction. **The Allies adopt different war plans** There were several plans as to how the French and the British would respond to a breach of Belgian (and Dutch) neutrality by the Germans. These included plan E, plan D, plan D + the Breda variant and a plan which involved camping on the French north-eastern frontier. * Plan E: advance to the Eschaut river. This was the first plan, in which the Belgian armies would retreat westwards while the BEF swung into Western Holland. This plan assumed that the Belgians would not be able to hold their positions and was a more cautious plan than the plan D later adopted. * Plan D: advance to the Dyle river (further inland). This had many (perceived) benefits. It meant that the Allied forces would bring the fight further away from France as well as covering more Belgian territory. * Breda variant: this included defending Holland using French strategic reserves. Doing this would ensure the addition of 10 Dutch divisions but it also diverted strategic reserves * posting the French army on the French frontier. This basically meant abandoning Belgium - this was diplomatically not feasible, obviously. Gamelin settled for plan D + the Breda variant. If he hadn't extended his forces so far forward, perhaps the war would have gone differently. The strategic French reserves certainly could've come in handy. Indeed, the Allies were initially rather unsure if they could reach the Dyle river before the Germans did (especially after witnessing the battle of Poland). The BEF was also not all too keen on entering Belgium. Only later, with reports of the Belgians and the Dutch constructing defences and an improved confidence in Allied strength and equipment, did Gamelin adopt plan D. [Answer] # Failure of German propaganda The French Army in northern France outnumbered the German invasion force, and was fighting a defensive battle on it's home turf, plentifully equipped, and surrounded by supportive French civilians. France fielded 104 full divisions, and had a 50% advantage in tanks, artillery, and trucks. However, three years of persistent, excellent German propaganda had demoralized the force at all levels. The French Prime Minister phoned Churchill and said 'We are beaten' *on the sixth day*, long before the actual outcome was decided, and four full weeks before the German Army entered Paris. Demoralized leadership is less likely to analyze correctly, to innovate, to judge risk properly, to demand achievement from their subordinates...and more willing to accept poor performance and mission failure. [Answer] **Better French organisation of their armoured forces** The French Army had more and better tanks than the German (at least 3,383 to the German 2,445), but decided to disperse them throughout their positions in what were known as "penny packets" to support the infantry. This negated their numerical advantage, and allowed the German Panzer forces to achieve local superiority where it mattered. Keeping their armoured divisions concentrated would have allowed for swift counterattacks which would, at the very least, have slowed down the German attack for long enough for the Allie's superiority in men, tanks and guns to be brought to bear. [Answer] One thing is missing: The [Mechelen Incident](https://en.wikipedia.org/wiki/Mechelen_incident) never happens. The initial plan for the German invasion of France was a frontal attack through the low countries into Northern France, just as in 1914. Furthermore, the idea was to start it much earlier than the 'real history' battle - shortly after the conclusion of the invasion of Poland, the idea being to catch the Allies unprepared. First it was delayed, then the plans were leaked in the above incident, causing a rethink and the invention of the Sedan concept. So what happens in this original plan? The German army crashes into Belgium and Holland in December 1939.. in the middle of winter, and, interestingly with much lower ammunition reserves. No doubt Holland still falls, and much of Belgium, but the weather makes the advance slower and neuters the Stukas; the German armour finds itself fighting head on battles against British Matilda IIs and French Char-1B tanks, which completely outclass them. Going into 1940, Germany never gets the chance to concentrate all her Armour into a single strike. The result is a stalemate, with a front line forming in similar battlegrounds to WWI. Except that the German economy is relatively much weaker than before; ironically it took the fall of France to put the German army on wheels - captured French equipment played a significant part at the start of Barbarossa. Italy sees how things are going and stays very quiet. By 1941, Germany is in a state of collapse. The Luftwaffe has been ground down in battles with the RAF and improved French planes; the Panzer arm is struggling against the numbers that the allies can put into the field, and the economy is disintegrating (in the 'real war', conquered France provided a lot of economic support to Germany as well). Seeing the writing on the wall, and with the Eastern border creaking ominously, the General Staff depose Hitler and announce an armistice. [Answer] Have the French invade Germany when Germany was invading Poland. France did send troops in and met little resistance, only to pull them back. Hitler really did bet everything assuming France would not act. He concentrated his forces on Poland and left little to defend Germany. [Answer] There are a lots of small ways the French could have made a difference. My favourite: **blow the bridges near Eben-Emael, on the Belgian-German border**. At the height of the invasion into Belgium these bridges carried more then 100 trains a day. Without this supply / support any attack would peter out. Mind that at this point in the war the Germans used a lot of foot troops and horses. Very little units had trucks. Most transport was done by rails. --- If you want to try for bigger changes, do try Hearts of Iron 4, or the earlier versions. It is quite possible to hold the German advance in that game, though not easy. [Answer] In his book, Blitzed: Drugs in the Third Reich, Norman Ohler claims that German soldiers during the Blitzkrieg were high on methamphetamines, which improved their stamina, etc. Perhaps if those drugs had not been invented, had been contaminated, or unavailable, or if there had been a problem of overdosing, then they would not have fared as well. [Answer] When the German army was driving through the Ardennes French reconnaissance airplanes did spot them. There is a bit of a debate on what happened with that crucial information after that. Lets say instead of the information not being put to use the French Air Force concentrated their efforts on the route the German army was taking. With the tanks concentrated in a little area that would of been a great chance to reduce their numbers. Another angle is after the war the Germans who were there reported their logistic were actually not very good. Their tanks relied to a good extent on captured French gasoline. Even to the point of just using French gas stations. So if someone had just went before the German army and destroyed the gasoline supplies. [Answer] There are many components to the western front situation, so I'll recoup some: ***1/ After WW1 the French were unwilling to go to any other war, since the bleeding was so terrible for them*** ***2/ The British Army was as usual a joke, with the British Navy and Airforce being the sole expression of British military capabilities, especially the Navy*** ***3/ While the German Army was woefully underequipped compared to the French, it had succeeded in drastically evolving from the WW1 mindset, where trenches and massive artillery usage were the deciding factors of the war. The French meanwhile had not.*** (it is not very well known, but all the way to the battle of France and during the totality of the German-Polish war, thr majority of the German army was relying on horses, not cars or tanks. Most of the artillery in 1940 was still carried around by horses and not modern weaponry) Counting on point 1, **I would first assume that the French would not attack German territory no matter what.** I've heard rumors of the French Army being pressured by the British to not enter Germany under threat of seeing their oil supply lines cut (as those were almost entirely under British control back then), because the British plan would've been, as is typical with them, to sink their "ally" and enemy altogether by ensuring that both sides remain about as strong, thus dragging on the war to impoverish both. However even if you take these rumours seriously, the French would never have attacked any way. The French Third Republic was a weak system where governments changed often and party alliances were necessary in all situations, and popularity for the war was so low that when the war was started, the speech made in the National Assembly *did not even dare to contain the word "War",* simply requesting "extraordinary military credits" rather than demanding national mobilisation. The French, all too scared after the bloodbath of the Great War, would've probably stayed put and tried to shoo the German away with their big Maginot Line anyway. With that option out of the way, there are a few ideas: Before the War even started, it was imperative for the French High Command to evolve with the times. Tanks weren't the WW1 tanks, and allowed for high power assaults that trenches wouldn't be able to hold back anymore. Aviation had also greatly evolved and needed to be taken along infantry and armor, which is what the Germans did. **The Blitzkrieg was a fairly simple but modern tactic of uniting infantry with armor along with air support, whereas the outdated vision was to use them separately.** The French did not understand the value of mixing all three, except by some like then Colonel De Gaulle, or [Marc Bloch](https://en.wikipedia.org/wiki/Strange_Defeat): **During The Phony War (39 to May 40), more military pressure should have been put by both British and French on the German border.** While the Germans had almost all their divisions in Poland, France alone could muster about 80 divisions against the 30 German divisions that were guarding the border. **Even if you don't consider a full on assault, skirmishes and pressuring the enemy was tremendously important, especially when the Germans were advancing quickly in Poland and needed to be stalled for the Polish Army to recover footing** (at the end of the German-Polish war, 80% of Polish soldiers were still standing, but it was a military checkmate because the Germans had taken vital parts of the nation due to their speed and execution with the Blitzkrieg tactics). In that same period, had Sweden not decided to simply let the German Army walk freely to Norway, the stalling of the Germans could have prevented them from getting full control of Norway before the British-French expeditionary corps had taken control themselves. During the War itself: * The Belgian line fell almost immediately, prompting the French to send their best equipped and manned army there, along with the British Expeditionary Force. **Had the Belgians held longer, the support force might've been able to create a frontline and stall the Germans there.** * The Germans pierced through the Ardennes and made a pincer move on that army. **Had the Ardennes been properly seen as a possible entry point and guarded, the pincer would never have worked.** * The British immediately decided to run and abandoned their defense positions, along with a huge amount of equipment, to run for Dunkerque and then home. **Had they not abandoned the fight as soon as the battle looked awry, then had they not abandoned their equipment without destroying it to save their men, and had they not made building a frontline even more difficult by running away in the first place, the 1st French army might not have fallen so quickly defending the British retreat.** Although to be honest by then the situation was very dire anyway. The rest is a long string of rather pitiful but unavoidable situations. **The French had superior weaponry in every way, but lacked both modern tactics and proper communications.** I don't know why communications were so poor, but there were actual articles in the news about 4 communist sympathisers that were tried and executed for sabotaging tank radios in the factory(since back then, Hitler and Stalin were allies). How prevalent was the sabotage, I do not know either. But in general, the Germans worked with efficiency, mixed troops, and a goal to advance as fast as possible so as to continously hustle french forces and never let them form a frontline. It worked so well because the french were constantly at a loss as to where the frontline was, while it moved every day, they sent infantry or tanks alone against mixed troops that would just break through any defense fairly quickly, and they did not have powerful enough communications to ever mount a solid counterattack. I hypothesised that had the Belgian Front held, or had the Ardennes been properly defended, or had the British held their line, things would have been different, but in reality I am not so optimistic. **The fact is that the Blitzkrieg will only be properly countered with somewhat modernised tactics only by 1943, after Stalingrad. From 1939 to 1942, the only thing that saved anyone from the German Army was Winter.** Nothing else stood, except the Channel I suppose. To last longer against the German forces was to win in the long run, essentially, and neither Polish, nor French, nor British, nor the USSR, stood the Blitzkrieg in its prime. Let me remind you that Moscow was only saved by Winter, with very little land left to conquer in 41, and Stalingrad was actually taken before being turned into a mass grave during the winter of 42. I've also let out a ton of details as this post is already extremely long, such as the replacement of the Top General of the French Army at the worst possible time, or the fact that after the 1st Army was lost in the Dunkerque pocket, the French were pretty much left with their pants down and really couldn't stop the German Army no matter what anymore since the other forces were less well equipped, experienced, and France had lost a lot of manpower after their best army was gone and a ton of British material was left freely to the Germans. But to me the real problem will remain the outdated tactics, misunderstanding about the nature of the war, where positionment wasn't as important as speed, where mixed units weren't even considered, and where the French High Command was completely incompetent at realising its mistakes from start to finish. Heavy military reforms before and during the war, or stalling tactics like harassment, were absolutely necessary and would've turned the tide in many ways. But since neither were done, the only important thing was time. The Germans were so advanced militarily despite inferior heavy weaponry that it took 3 years for anyone to catch up and beat them head on. [Answer] If I have time I’ll cite some sources later and get specific number. Something not mentioned yet is to start the war early. Stand up to Germany before Poland. Stan up to them in March of 39 with the invasion of Czechoslovakia. The balance of mechanized forces and specifically of air forces would have been more in the allies favor at that moment. [Answer] I have repeatedly wargamed this battle and in most cases, as the allies, have achieve a much better result than the historical one. In the quest for historical accuracy there was only one way to achieve the dismal results of May 1940. If the French player is given information one day old the results end up looking pretty much like the historical ones. This reflects the failure of command and communication in the French army. The French were fighting the last war, their command communication control and information network was setup to fight a static war not a manoeuvre war. This is reflected in the command styles. The French army was commanded by general officers a long way behind the front. First information had to get them, they had to make decisions on that already old information and then get orders to the people doing the fighting. The German general officers of the Panzer Divisions that exploited the breakthroughs fought near the front of their Divisions. They could make rapid and accurate decisions on where and when to apply force to destroy their enemies will to fight and to exploit weakness, caused in many cases by their enemies reactions to old information. There are many ways to improve the outcome of the battle for France. Worthy of mention is the concentration of the superior French tank forces into a proper mobile reserve capable of defeating the German penetrations. My choice would be to fix the C3I problem, get the allied generals out of their Chateauxs and onto the front line where they can see what is really happening in real time. [Answer] After many good answers and further research, it seems that, by all accounts, the Allies should have won, surprisingly enough. The Nazis won thanks to a ridiculous string of coincidences that would have had put any reader out of the story, had it be fictional. At the end of WWI, France had the most modern army in the world. A massive pool of truck instead of reliance on trains for moving troops, the biggest air force of the planet, troops being equipped with semi-automatic rifles and a massive number of LMGs, turreted tanks and combined operations... And while Great Britain put comparatively more efforts into its navy, its army was about as advanced and had even started working on APC vehicles. How do we get from this to such a debacle? ## The post-WWI years After war, both nations knew they needed a rearmament program, to thoroughly modernize according to the lessons learned form the war. Of course, rearmament programs are expensive, and when the deadly, exhausting, impossibly costly war that was supposed to be The Last One is just finished, some people may think that diverting funds sorely needed for reconstruction to the army is not the best idea. In the aftermath, the British stop pursuing combined arms doctrines, which are slowly forgotten. And the general Estienne, father of the French combined arms doctrine, dies early before having time to further develop his ideas, resulting in the same loss. ***tl;dr***: Had either not let their armies decay, especially doctrine-wise, they would have been prepared against the new German tactics and blunt their advance. Britain was focused on trying to hold together a dying Empire, and the focus on the navy and on rebuilding the economy left the army deprioritised, and it went back to a smaller expeditionary force, not unlike it was pre-war, even if its rearmament program was somewhat less disrupted. Meanwhile, France starts its complete rearmament program. It develops a rather excellent light machine gun, then starts working on a new semi-automatic rifle and... thing peter out, especially after the 1929 crisis. Then new left-wing government, focused on social progress but openly contemptible of the traditionally right-wing army, cuts military funds as much as possible. A French head of state of the time goes as far as declaring that "If I could, the army would not get one centime in peace time". Even worse, fearing the potential influence of the army, they change the appointment system for top officers: instead of picking from a list compiled by high command based on competence, they are now directly nominated, based on political affiliation. But wait, you might say, wasn't that exactly what had happened before WWI? Didn't France have to fire a third of its generals early in WWI because of that? Didn't they know that was a bloody stupid idea from experience? Yes they did, but remember, the priority was to make sure the army was not a political menace. And anyway, who would be insane enough to start *another* world way, after all? As the threat of a new war loomed, France picked the rearmament program back up, but it was too little too late. They had great planes, but not enough - and the newest model was basically at the prototype stage and sent to the front from the factory. They had great defensive tanks, but with flaws not yet kinked out. They had great sub-machine guns, but only a few hundreds had time to reach the troops. They had great rifles, but had only time to equip troops with a bolt-action version planned for rear-echelon troops. The semi-automatic version, which would have been one of the best rifle in the entire war, was barely complete, and didn't even have time to leave the factory (fortunately, they did manage to hide its existence to subsequent German occupation forces). ***tl;dr***: Had the French government at the time not seen the army as a political enemy and cripple its high command, it could have developed new doctrines and efficiently respond to new German tactics. ## The appeasement politic Interwar France and Britain have been criticised a lot for their appeasement politic, believing that if enough concessions were to be made to Germany, they wouldn't do something as stupid as start *another* war. Had they read *Mein Kampf*, they would never have believed Hitler's words about wanting peace. (Then again, that book is allegedly so badly written to be painful.) It is difficult to imagine what an early war would have looked like, but Germany probably was more unprepared than others. Had the Allies (possibly without Great Britain) gone to war over Czechoslovakia, it may have gone badly for Germany. But this would have required a significantly different political climate at least in France if not in Britain as well, so this is somewhat difficult to imagine it happen at that point. However, had the Franco-Soviet 1935 treaty held, Germany would never had stood a chance in a war. Had Stalin compromised over not sending troops on Polish territory, or had France been less eager to appease Germany, the Soviet may have very well ended up with the Allied at the start of the war. ***tl;dr***: Had the alliance with the Soviet worked out, it would have been a race to Berlin five years early. Speaking of Poland, they did quite better than is commonly believed (mostly based on Nazi propaganda, as it happens). But as to not, ah, provoke Germany, France and Britain had stopped Poland to fully mobilize, considerably hampering its war effort against German and then Soviet attack. Even worse, its strategy was to hold long enough for the French army to launch an offensive across the Rhine, and for the British air force to launch a bombing campaign against Germany. Neither were actually prepared to conduct such operation, and had assumed Germany would be deterred simply by the threat. France launched a probing attack, met no resistance but decided to withdraw behind its fortification. Britain sent a few token planes, met no resistance but decided to stop further attacks. However, even unprepared (which they shouldn't have been), attacks against the undefended western Germany while its army was stuck in Poland could have stuck a heavy blow, either stopping it from finishing Poland or at least seriously weakening for the counteroffensive. Also the offensive happened right before Poland would receive thousands of modern planes for its air force. I suspect Germany wanted to attack before that, as it would have seriously challenged the Luftwaffe. ***tl;dr***: Had the Allies been prepared to support Poland, they could have dealt a potentially fatal blow to Germany. ## Defensive strategy Nonetheless, as the years pass by, with more and more nations falling toward extremism, it had become clear that a new European war could happen again. The "twenty years of armistice", as Field Marshal Foch had called the Versailles treaty, were coming to an end. Britain could count on the Channel, its navy, its air force and an alliance with several continental powers to prevent a war from reaching its homeland. France, however, was right next to the biggest potential threat, a revanchist Germany that could field twice as many men, and that had already proved its capabilities at massive industrial war. Which is why they did the logical thing and developed the Maginot Line. But wasn't the Maginot Line a terrible idea that miserably failed? No, in fact it was a great idea and, when used properly, it worked exactly as advertised. (See below as for how it was *not* used properly.) It was the brainchild of WWI veteran Philippe Pétain who, despite some, ah, unfortunate political decisions later (again, see below), had still been one of the best generals of WWI - so not an idiot, and not an idiotic idea. The Maginot Line was an impassable line of fortifications, estimated to hold with a contingent against an army *fifty times* more numerous. And, contrary to much later rumours, France was perfectly aware that the Germans would push through Belgium - and so was Belgium, in fact, which is why it was part of an alliance with France and Great Britain. Belgium was to build its own equally impassable Meuse–Albert line. The problem is, impassable fortifications cost a lot, and Belgium simply didn't have enough money. So they asked France to lend them enough funds for the project. Which France declined (see above for why they would do such a thing). Which is why the Meuse-Albert line was delayed and scaled back. At the onset of the war, it was clear that the Belgian army wouldn't be big enough to hold a determined German push at its border. ***tl;dr***: Had France lent the money to Belgium, no German army could have crossed their eastern border. Nevertheless, with the bulk of the French army and the British Expeditionary Force to back them up, it would still be enough to stop a German attack. As long as they were deployed in advance, that is. But if tensions rose, as allied nations, of course this is exactly what would happen. But then the remilitarisation of the Rhénanie happened, and neither France nor Britain reacted, not wanting to declare war on Germany over internal troop movements. After all, they simply wanted to legitimately be able to defend themselves, right? Belgium saw this appeasement politic as a sign that it couldn't count on the Allies, and thus left the alliance, hoping that neutrality would avoid it to be caught in the next war. Which meant not having foreign troops on its territory. Which meant that when Germany attacked, French and British had to rush from the French border to the frontline, losing much of their defensive advantage, and the easier to defend eastern Belgium being already overrun when they arrived. From there to Paris, there were only flat, hard to defend plains. ***tl;dr***: Had Belgium not left the Allied for neutrality, the German army would have been stopped, or at least considerably weakened, at its eastern border by the Allied forces. But then, why didn't the French simply extend the Maginot line? Actually, they did. But two years were simply far too short a time to build such fortifications, especially on flat terrain. ## The Ardennes gambit Now, the German plan was to repeat the Schlieffen plan that had nearly worked so well in the previous war: launch a massive fast offensive through Belgium and run for Paris to knock France out of the war early. Sure, it had failed last time, but it had worked the time before that. And Germany didn't really have other options anyway. At least, this was the plan before it fell in the hands of Belgian intelligence, when a German courrier plane randomly crashed in Belgium, carrying said plans. And while the Belgians tried their best to make it look like the whole thing had burned, the Germans knew to be better safe than sorry: they needed a backup plan. So they did what would otherwise have been an idea worthy of the Chemin des Dames offensive in its utter stupidity: send two tank corps through the Ardennes forest. Now, the French knew perfectly well that an Ardennes tank offensive was possible, and that a tank army could cross it in two days. Specifically, Maxime Weigand, possibly the most underrated general of the XXe century, had warned François Gamelin, the French chief of staff, of this. (It was also Weigand that told Charles de Gaulle that his idea of a small, mobile professional army of a hundred thousand men for defense would simply not work - probably because the British had done the *exact same thing* during WWI and it had been ground down to oblivion in a few months, and thus earning De Gaulle's unending antipathy. But this is a story for another time.) Once entrenched in the Ardennes forest, even a modest force could have stopped a tank offensive. Tanks offensives are meant for flat terrain: forests make it easy to ambush even big armored forces, and once a few tanks are burning on either side, can easily become death traps. Unfortunately, as noted above, top officers weren't named for their skills anymore, and Gamelin was a courtier but not a good general. Which is how he ignored both warnings not only from Weigand, but also from French intelligence in Germany about their innovative light tank tactics and training. ***tl;dr***: Had Gamelin actually listened to his best general or his detailed intelligence reports, he would have easily destroyed the Ardennes tank offensive with a few well-entrenched forces. But then, even without opposition, having two tanks corps cross a forest like the Ardennes is no trivial task. In short order, tank columns turned into giant traffic jams, easily seen by French aerial reconnaissance. When receiving such reports, however, the officer in charge of defending the sector dismissed them as "a few scout cars". So the air scouts went back with tankers on board their planes, to identify the tank models and make unambiguous, detailed reports of the tank force. No matter, the officer dismissed the new reports. When the French air force asked him if he needed any support, he answered none whatsoever. One may wonder if he was that incompetent, or if it wasn't actual treason. Had the air force been sent to bomb the piled up tanks, it would have been a massacre. The few survivors to make it would have been easily stopped by even a light force, had it been forewarned. ***tl;dr***: Had the officer in charge of the Ardennes defense not been terminally incompetent/a traitor, or had someone gone over his head (or executed him for treason), German tanks would never have made it out of the Ardennes. ## The Battle of Belgium The Belgian lines breached, the Allied forces on the back foot, and now a tank force emerging from the Ardenne to envelop them. As in 1914 the French government finally pulled itself together, fired the incompetent, politically appointed generals and let actually competent ones do the job instead and save the day. Namely, they pulled the aforementioned Weigand from retirement and gave him Gamelin's job as chief of staff. Now, you would think Weigand was the right man for the job: respected by friends and foes alike, right hand man of Allied supreme commander Ferdiannd Foch during WWI, architect of the Warsaw Miracle, absolute légaliste with an unwavering loyalty to democracy and to the Republic. But with the entire French army disorganised, lacking radios and fast-moving forces, about to be encircled, what could even he do? What he did, was to understand that the main German armored push was overextended, and that there was an opportunity: the French army would counter-attack in a pincer move, hammering the German forces against the British and Belgian anvil, and cut off the spearhead. British high command agreed with the plan, and so do modern experts, who argue that it would have indeed worked. And then the British ran away. Specifically, John Gort, commanding the British forces on the continent, panicked and ordered his army to rout towards Dunkerque - leaving behind piles of equipment for the Germans to take instead of properly destroy it all, but destroying bridges, trapping the French and Belgian forces that would be forced to retreat later. With their flank gone, there was no more hope of victory for the French and Belgian forces, so they started to retreat as well. Both fought hard - the French fighting retreat was especially brutal, taking the highest relative death toll of all the European armies of the early war. German general Heinz Guderian, would in fact call the battle of Stone one of the two worse he ever saw - along with freaking Stalingrad. In fact, the one thing that saved the British army (along with Hitler's tactical mistake at Dunkerque) was the French army standing against literally impossible odds for the entire retreat. *Note: remember that next time you hear about a (much more recent) surrending monkey joke or about the Miracle of Dunkerque: the British ran and only made it because the French stood and died. Not even the guys who invented the Polish lance cavalry charging panzers myth dared to mock the bravery of French soldiers. In fact, Hitler himself called them the best in the world after the Germans (of course), in the aftermath of Bir Hakeim. But again, this is a story for another time.* ***tl;dr***: Had John Gort not panicked and the British stood their ground instead, the German advance would have been smashed by a pincer move, stopping the German advance. ## For what of a fistful of nails Had the German advance been blunted, things would have reverted to a 1914-again state: a grinding war with neither side capable of advancing. This would have pitted industrial and manpower reserves against each-other, and like for WWI, the Allies would have had the upper hand with access to the immense American industry. The Soviet Union may have somewhat balanced this by trading with Germany, but this is neither certain nor guaranteed to have lasted. (Soviet-directed Communist agents were executed in France for sabotaging planes, for example, so the Soviet Union was, at least initially, somewhat serious about their pact with the Germans.) New weapons would have made a difference. Many northern French and Belgian cities may have been razed by artillery fire. New railway trains may have been used to destroy fortifications like on the Maginot line, but the enormous investment on those and on the follow-up force needed to have a chance to advance. As such, like in WWI, it is improbable (though not impossible) for the Germans to achieve victory that way. In addition, and contrary to what many think, the Allied had the initial technological advantage. In fact, the reason later German tanks were so good was partly because of the French tech they got their hands on, and on the resources of the French had from their colonial empire, allowing for better alloys. Had the war become static, the Allies would have kept the technological advantage, especially with Hitler increasingly obsessed with wunderwaffen and the French armament program being finally completed and extended. Given how fast it rebounded after the war, and as there were pre-war projects already, France may have been the first one to develop rockets and even jet engines. it may even have fielded ramjets, whose development were interrupted by the Occupation. They also had few wagons full of uranium ore that spent the entire Occupation pointedly forgotten in some railway depot, but while it would have considerably helped nuclear development, it is far from certain that the war would have lasted long enough for an atomic bomb to be finished. ***tl;dr***: Had the initial push been stopped, it is improbable that Germany could have won WWI-bis. ## Aftermath At this point, the French homeland was lost. There was next to nothing left between the German army and most of France, with indefensible open terrain in the way. But France was still not ready to give up. it had 150 000 surviving troops evacuated from Dunkerque. It had an army holding the Italians at bay in the Alpes. It had an oversea empire, from which colonial troops could be raised. It had a modern, rather powerful navy. So the French government did the sensible thing, gave up the indefensible territory and prepared to move the capital to Algiers (as Algeria was considered more or less French homeland at the time). In this time of crisis, they decided to unearth this old Roman tradition: nominate an emergency ruler with dictatorial powers, so the slower democratic powers can be temporarily been bypassed for the duration of the crisis. After all, if it worked for the Romans... So they chose the victorious chief of staff of WWI (Foch was the supreme commander of the allied forces at this point, which was not the chief of the French army), the Lion of Verdun, a national hero whose military skills had been well-proven: Field Marshall Philippe Pétain. Unfortunately, he was also going senile and had never liked politicians to begin with. This was the "divine surprise" that fell on the lap of the far right, who seized the opportunity to take power in Pétain's name and stage a coup d'état. While officially called the "Nation Française", it would be remembered as the Vichy regime. In short order, being ideologically close to Germany and Italy but deeply anglophobes, they would sign an armistice (not a capitulation, because that would make the army lose face, a big no for a fascist regime) and nevermind the loss of half of France and basically becoming a puppet of Germany (even if officially neutral in the war). Oh, remember the French navy? half of it was stuck in Toulon and, much later, scuttled itself so the Germans wouldn't get their hands on it. Another half was in Mers-el-Kebir, and the British murdered it with a surprise air attack, so (agian) the Germans could't get them - but the French sailors were actually busy scuttling said ships, so not only were they especially defenseless against a surprise attack from an ally, but even more died trapped in the ships. So while the armistice was very unpopular for many French, many also felt betrayed by the British and decided that neither side was worth it anyway. Even then, and despite everyone (including the Allies) considering the Vichy regime as the legitimate French government, "Fighting France" (later Free France) was formed as a government in exile refusing to stop the fight. While only a few troops and colonies joined it, plus those forming Résistance groups in Vichy and occupied territory, they became increasingly popular and, in the case of Bir Hakeim, even instrumental in the war. But again, this is a story for another time. ***tl;dr***: Had the French government named the maybe too modest Weigand instead of Pétain, the French Republic would have kept fighting from Algiers. ## And the Devil is laughing still Now as this is Worldbuilding and not History, let's try to make sense of it. Because as it is, this is all too ridiculous to use in a story, nevermind that it actually happened. So let's take this ridiculous chain of coincidences, and the fact that it suddenly started to fall apart everywhere. Add the countless failed assassination attempts against Hitler. Add that the Nazi regime was not simply evil, but Evil. They didn't just invade Europe, raze cities and murder countless civilians. They didn't simply have insane racial theories they actually attempted to put into practice, and allied with an equally monstrous regime on the other side of the world. But not only did they *industrialize genocide* (and yes, I am the first to be surprised that it has to be reminded nowadays), but they actually wore skulls as a symbol. And the SS had a war song with those lyrics (translated, obviously): ``` "And the Devil laughs with us" "Ha! ha! ha! ha! ha! ha! ha!" ``` Also Hitler was into occultism. ***tl;dr***: there is one obvious explanation: Hitler made a deal with the Devil. Seriously, why don't more people use this in secret-history or alt-history works? [Answer] Strategic Depth The French invested heavily in the Maginot line (and famously didn't extend it across the border with Belgium), and the Germans just blitzed right past it. If the French had stationed their army throughout their country, the Germans would have had to fight for each city, and held men in reserve to hold the countryside, too. [Answer] The British held back some of their air forces for defense of the home island and [withdrew](https://en.wikipedia.org/wiki/British_Air_Forces_in_France) others when the it seemed that the Fall of France was inevitable. This is usually considered a wise (though painful) move on the part of the British, one that made possible their later victory in the Battle of Britain. In an alternative history, what would have happened if the British *increased* their air forces in France, even to the point of denuding their own air defense? One version (and arguably the more plausible version) of the alternative history would have been that France would have fallen anyways, followed rapidly by a Britain which could no longer contest the Luftwaffe. On the other hand, just maybe if the British went all in with their air force then they could have bought time for French forces to regroup. [Answer] **Get the French inside the German OODA loop** The French generals were veterans of WW1, so their thinking was for static warfare against a dug-in enemy. They set up shop well behind the lines and assumed that motorcycle dispatch riders would provide them with sufficiently timely information (source: "[The World at War](https://en.wikipedia.org/wiki/The_World_at_War)"). In the event the German doctrine provided German unit commanders with sufficient flexibility to exploit local advantages, and modern communication technology (especially radios) kept the rear echelon able to respond in a timely fashion. There is now some argument about the extent to which this was an official doctrine and the degree to which the Germans made it up as they went along ("No plan survives contact with the enemy"), but either way it was the crucial advantage. The result was that during the Battle of France the French command repeatedly ordered "stop lines" to be created, only to learn that these lines had already been overrun before their orders arrived. If the French had been using similar doctrine to the Germans then they would have been ready for a war of maneuver instead of a rerun of the WW1 trenches. This lesson has now been generalised (no pun intended) into the concept of the "[OODA loop](https://en.wikipedia.org/wiki/OODA_loop)": Observe, Orient, Decide, Act. The point is that if you can do this faster than the enemy then you have a decisive advantage, because whatever the enemy does, you can be there ahead of them. In the Battle of France the French high command had a very long OODA loop, on the order of a day, while the German high command had a much shorter one. Hence the French were only able to react belatedly while the Germans took the initiative. [Answer] ## Breaking the ENIGMA I think WWII had been significantly changed, if British intelligence were able to break the ENIGMA earlier. The ENIGMA was a cipher machine to encrypt military communication during WWII. The decryption key changed every hour, so it was almost impossible for the Allies to read the messages (because the key was written on a physical handtable and was very well protected). So if it was possible for a spy to extract that handtable without the Germans noticing, they could hear all military communications from the German, to predict any troop movements or tactics. This is an abstract from [Wikipedia](https://en.wikipedia.org/wiki/Enigma_machine): > > The Enigma machines were a series of electro-mechanical rotor cipher machines developed and used in the early- to mid-20th century to protect commercial, diplomatic and military communication. Enigma was invented by the German engineer Arthur Scherbius at the end of World War I.[1] Early models were used commercially from the early 1920s, and adopted by military and government services of several countries, most notably Nazi Germany before and during World War II.[2] Several different Enigma models were produced, but the German military models, having a plugboard, were the most complex.[...] > Though Enigma had some cryptographic weaknesses, in practice it was German procedural flaws, operator mistakes, failure to systematically introduce changes in encipherment procedures, and Allied capture of key tables and hardware that, during the war, enabled Allied cryptologists to succeed and "turned the tide" in the Allies' favour.[7][8] > > > Also look for: [The Imitation Game](https://en.wikipedia.org/wiki/The_Imitation_Game) [Answer] To add to the earlier natural cause of rain I suggest something smaller like a plague or food poisoning. If all the provisions had been tainted by Salmonella, Ergot, Dysentery, Cholera and Botulism (chance or with the aid of the resistance) and the fighting forces had been down to 25% for a week it would have made a lot of difference. ]

[Question] [ A new girl moves into town with her eccentric parents who are self-proclaimed, professional vampire-hunters. They, for some reason, are completely convinced that their new neighbor is a vampire, but so they were of the previous 10 'new neighbors' who all turned out to be completely normal people. Not everyone who lives in a Victorian mansion is a vampire, jeez. Asking around reveals that the 'vampire' is actually a really pleasant person to be around, and has to take care of his daughter all alone since his wife died long ago. He also frequently does volunteer work, saves cats out of trees, and helps old grandmas cross the street. All right, nobody has ever seen him outside during daytime, he seems oddly afraid of garlic and doesn't ever eat, even during the neighborhood barbecue he hosted last week... But that's just coincidence, right. Right? The big reveal that vampire-dad IS actually a vampire shouldn't be a surprise to the reader, but somehow his only (non-vampire) daughter had no clue. This is a little bit of a plot hole, as his daughter is around 15 years old and is completely aware of all the cliche vampire tropes. She has him as her only caretaker yet not once asks herself why her dad can't go outside during the day and seemingly never eats. Why? **Vampire-dad...** * can't stand sunlight. UV or any other light doesn't bother him, but a single ray of daylight will cause him to spontaneously catch fire followed by instant death. So although he technically can go outside during the day, he really shouldn't risk it. * is seriously allergic to garlic. Even the smell seems to cause rashes for some weird reason. * can't eat normal 'human' food. If he does, he'll throw up after a while. * has to get his daily blood-fix to prevent sanity slippage. * gets his blood-fix through a weird fruit he cultivates in his own backyard. He jokingly calls them 'blood-oranges'. They hold no nutritious value to humans and taste absolutely horrible. * has super strength, super senses, super reflexes and can turn into black mist. * can use none of the above powers during the day. * sleeps like any other person, but preferably during the day rather than at night. * has a lot of money and doesn't have to work. * is on good terms with his daughter and the entire neighborhood, save the two vampire-hunters. * is a really nice person and doesn't want to hurt anyone. * does not have a reflection. Not in mirrors or any reflective surface. Everything he wears or in some other way is not directly part of him, however, still gets reflected. * has unusually large fangs. **Vampire-dad's daughter** * is not showing any vampire-traits (yet) * is pretty smart and is aware of vampire classics like dracula, but somehow can't connect the dots. [Answer] ## By having him claim a long list of medical conditions ### [Photosensitivity](https://en.wikipedia.org/wiki/Photosensitivity_in_humans) There seems to be a medical condition for everything under the sun. In this case there are a number of medical conditions where one of the symptoms is the person's skin becomes sensitive to sunlight. A person can even be allergic to UV without a specific medical condition causing it. You can even have him claim a medical condition that his eyes are extremely sensitive to light ([Photophobia](http://www.allaboutvision.com/conditions/lightsensitive.htm)), and so does not like any strong light source. ### [Garlic Allergy](https://en.wikipedia.org/wiki/Garlic_allergy) People can be allergic to garlic. Symptoms can even be induced by inhaling garlic dust, so needless to say he tries his best to keep his distance from it, lest he wants his throat to swell shut and die. In his case I would recommend explaining that he is allergic to a chemical in garlic which can also be found in onions and leeks, so he avoids those too. Having him freak out over a sight of a leek when it is of no threat to him helps build the charade, since people know vampires are not allergic to leeks. ### Cannot eat solid food There is even a medical disorder for being unable to eat solid food: [eosinophilic gastrointestinal disorder](http://archive.azcentral.com/news/articles/20100524scottsdale-boy-with-food-rejection-disease-0521.html). In short the body triggers an immune system response when trying to eat solid food. Most common result is in vomiting up the solid food. ### Having Fangs [Porphyria](https://en.wikipedia.org/wiki/Porphyria) and a number of [Ectodermal dysplasia](https://en.wikipedia.org/wiki/Ectodermal_dysplasia) type syndromes can result in the classic vampire teeth. However there is a slight problem with this: > > * has a lot of money and doesn't have to work. > > > The witch hunters will question, if he is so rich that he does not need to work, then why does he not see an orthodontist to get his teeth fixed? My recommended response would be to say he does not care: it does not impact his ability to eat, and he does not care about his smile, therefore why bother getting it fixed? Other reasons for not getting it fixed includes: he really really does not like dentists let alone orthodontists or he claims most forms of anesthesia do not work on him (and in some cases even makes the pain worse) and as such it would be a rather painful experience to get it fixed so he has been putting it off, but will eventually get around to doing it. ### Reflection & Mirrors *For this answer I am assuming devices like cameras can still take a picture of him, otherwise it would be very difficult for him to explain why he and no one else have any pictures of him and you would then need to consult this question on [Plausible explanation for lack of reflection in a mirror](https://worldbuilding.stackexchange.com/q/7117/21704) and reflect on the answers to it for help.* Mirrors and reflective surfaces can be straight up evil for someone with sensitive skin. Dad tells the following story to guests he hosts: > > One day he was minding his business in his house and took a nap in his living room recliner. He wakes up to find the whole side of his face and right arm inflamed and covered in a rash. He realized that a neighbor had park their truck, which had lots of chrome on it, on the street that day. The sun just happened to be at the correct angle while he was sleeping to hit the chrome and shine a beam of daylight briefly into the house and hit his arm and face. The rash took days to go away and ever since then he absolutely despises everything that can reflect sunlight. > > > The story of course is a total lie, but he can use it to explain why the only mirror in his house is in the bathroom, why all of the cutting knives in his kitchen are ceramic, and why he avoids cars with lots of chrome on them. Because of his supposed skin condition it would be normal for him to always wear clothes that cover as much skin as possible and hats/hoods that provide as much head covering as possible. So his face would be the only thing at risk of being caught in a mirror. Since his face would still be invisible to a mirror he will need to be vigilant to spot mirrors and reflective surfaces and see if he spots anyone else in the reflection. If he can see their face in the reflection then that person will be able to see his lack of face in the same reflection. Additional things he can do to help avoid reflections include: * Have him like using plastic utensils and paper plates, to help avoid additional reflective surfaces. * His car would have dark tinted windows so other drivers cannot see who is driving the car if they look at his car through one of their rear view mirrors. This also may provide the necessary protection if he has to do an emergency drive in the day. * Avoid public restrooms (do vampires even need to use the restroom?) ### Conclusion Some people seem to struggle with lots of medical conditions. Have the vampire dad do his research and fake all the symptoms needed to make it look like he has the above medical conditions and his daughter will likely believe it. It may even result in her being quick to defend her poor suffering dad from such allegations of being a vampire, since they do not understand him like she does. Humans are good about rationalizing things and will tend to assume the more plausible explanation is the most likely one. As a result who would she believe: Her dad saying he has eosinophilic gastrointestinal disorder or a stranger saying her dad is a vampire? After all vampires do not actually exist... right? Edit: Added sections on Having Fangs and Reflections & Mirrors [Answer] ## He works night shifts. Now I know you said he doesn't *have* to work, but he could *choose* to work as a way of maintaining the masquerade: * Night shift workers generally have nocturnal sleep patterns anyway, so nobody would question the fact that he sleeps all day and only comes out at night. * If he's asleep during the day, and out working all night, his daughter won't see as much of him as she might otherwise do, and will have less of a chance to notice his more vampiric traits. This wouldn't stop him being on good terms with her, of course - she's used to it, as he would have been at this for a while, and he can make it up to her on the weekends. * If he works as, say, a security guard in one of those isolated checkpoint booths, nobody will be around him for long enough to notice that he hasn't eaten anything all shift, and things like the fangs and lack of reflection will be harder to notice because, y'know, it's night and it's dark out. As for some of the other things, @Anketam has the right idea with the garlic allergy, but here's a couple of alternative explanations for why he doesn't eat: * He *does* eat, at least on occasions where him *not* eating would be conspicuous (for example, at the barbecue you mentioned). Depending on how long "a while" is, he should have enough time to excuse himself and go throw up in the nearest toilet. People will just assume he's gone for a wee or something, and if anyone does hear him throw up, he can claim the food disagreed with him. * Alternately, he can claim he's on some kind of "fad" diet where you can only have blood-oranges and liquids. There are all kinds of silly diet fads these days and it would be hard to tell that he's just making it up. [Answer] # Maybe she isn't that bright You are kind of assuming that the daughter is a bright and inquisitive teenager that is fully aware of her surroundings and world, but what if she wasn't that bright or, like most teenagers, just wasn't really concerned about anyone but herself. Make her the popular girl who is more concerned about her hair and the boys in school than the fact her father doesn't like to go outside. Make her embarrassed over his stupid hobby of cultivating "blood oranges" in the back yard. Give her a smart phone that she plays on 24 hours a day. That would surely thwart any awkward "Dad, are you a vampire?" questions well into the second half of your book. [Answer] **He could tell everyone that he is an extreme Cosplayer.** In our modern society there is nothing wrong with identifying as a vampire in your free time. If his neighbours are broad-minded they will just leave him alone. They might talk about the "crazy vampire-fan", but as long as he is a relatively normal member of society when it comes to social interactions everything is fine. He goes to the barbecue, helps the old lady, cares as a single-dad for his daughter - and when he is alone he likes to pretend to be a vampire. Odd, but people would get used to it. This way everyone would think the new people are the crazy ones. "He is a vampire!" "Yeah sweetheart, of course he is! We all know about that hobby." "But, but -" "Leave the man alone! It's not easy being a single-dad caring for his teenage daughter!" His daughter will think he is kind of crazy and embarassing - but have you ever met a teenage-daughter NOT thinking like that about her dad? As soon as something suspicious happens, like him not having a reflection, he can just pretend it's a new magic-trick to make him seem more like his rolemodel Dracula. "Not this again dad...!" This would easily explain all his "quirks". [Answer] ## Let him be known as "vampire" dad If he pretends to have several medical conditions as [Anketam suggested](https://worldbuilding.stackexchange.com/a/69155/32694) which rather obviously fit a vampire and is regularly involved in the local community, sooner or later someone will nickname him accordingly. Thus he will jokingly be known throughout the community as "vampire", making the fact that he could actually be a vampire unlikely to occur in anyone's thoughts. If some of his *oddities* are known, he won't have to hide them all the time, making life much easier. *"When should we start the next town meeting?" - "Let's wait till dusk, so that our vampire can join us."* I imagine it to be quite hard in such an environment for the vampire hunters to convince anyone that he is in fact a vampire. [Answer] To put a slightly different spin on it: # Don't Hide It It sounds like you intend the story to be at least a little bit humorous, so in that case it's a perfectly legitimate literary device to have him incredibly obvious, yet no-one except [character] can see it. For example, the first time he meets neighbours Jim and Steve the conversation might go like this: Jim: "Nice to meet you, I'm Jim." Dracula (in thick transylvanian accent): "And I am Dr. Akula. Who is a normal human and not a vampire at all." Steve: "He's a vampire! Look at his fangs!" Dracula: "It is very rude to point at vampires. And people. Because I am not a vampire." Steve: "For gods sake man, he's wearing a bloody opera cloak! How can you not see this?" Jim: "Don't be ridiculous, of course he's not a vampire. He said so himself, and I'm sure *he* would know if he was a vampire." Ah, here's the tropes page: [Only Sane Man](http://tvtropes.org/pmwiki/pmwiki.php/Main/OnlySaneMan). Also see [Devil in Plain Sight](http://tvtropes.org/pmwiki/pmwiki.php/Main/DevilInPlainSight) [Answer] For his problem of throwing up after eating normal "human" food, there's a logical answer. He does prepare meals for himself and his daughter, he does go to communal things like barbecues, and he does eat at these times. He just has to make sure he has a toilet nearby, so that he can go and throw up afterwards. This will be indistinguishable from bulemia. According to bulemics, it's entirely possible to conceal this successfully from the world for long periods. And for vampire dad, if anyone does spot the problem, then mentioning bulemia or an eating disorder will probably stop them asking more about a rather personal subject. Mirrors are the real problem though. Film cameras and digital SLRs won't show him (although he might show up on more basic digital cameras). If his daughter has binoculars or a telescope or anything like that, he won't be visible through them. And on a day-to-day basis, reflections in windows won't happen. This is actually going to be incredibly obvious at night if they've got the lights on and the curtains open - the entire rest of the room will be visible in the reflection, but he won't be. If you remove the "no mirrors" rule, then it's somewhat plausible. With this though, it's categorically impossible that someone wouldn't notice this very quickly, and equally impossible that his daughter wouldn't notice and question it. [Answer] ## He has [Porphyria](https://rare-diseases-conditions.knoji.com/porphyria-the-vampire-disease-that-started-the-legend/) At least that's what his daughter thinks. **Sunlight** Porphyria is a blood disease that is commonly referred to as the "Vampire Disease". People with Porphyria have extreme responses to sunlight where their skin blisters, bubbles, and itches when they go outside. They must spend the majority of their life indoors or completely covered to avoid this. **Fangs** Another symptom is the tightening of skin and gums which can sometimes make Porphyia patients appear to have enlarged teeth or [*fangs*](https://www.google.com/search?q=Porphyria%20fangs&espv=2&biw=1280&bih=934&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj4m_C4wN3RAhVW2mMKHcjfDUAQ_AUIBigB#imgrc=9itt21DlH5LVhM%3A) (WARNING: The hyperlinked image is GRAPHIC!!!). **Garlic (and other foods)** Porphyria also can cause strange allergic reactions or onset nausea to some foods. Garlic is one of these. People with Porphyria have to be very careful with their diet, because some foods can aggravate their symptoms. Garlic, in particular, can make people with Porphyria experience extreme pain or nausea. The vampire in your story could excuse himself from most meals by simply stating that he doesn't want to experience any negative symptoms. **Mirrors** People with Porphyria can have an aversion to mirrors because the disease makes them look so unlike themselves. Your character may look relatively normal, but you could explain that he doesn't keep any mirrors in the house because he can't stand the sight of himself. When he goes outside, he could wear a wrap or something around his head for the dual purpose of protecting himself from sunlight, and trying to keep his "disgusting" appearance from his neighbors. This would keep him from appearing in any reflections in front of his daughter. **Additional** Porphyria can cause patients to have [red or purple urine](https://en.wikipedia.org/wiki/Porphyria#/media/File:Urine_of_patient_with_porphyria.png) which is where the "blood drinking theory" originated. Apparently, in the old days, people with Porphyria actually would sometimes drink animal blood to treat their anemia. Porphyria is a genetic disease but it doesn't usually reveal itself until a patient is in their late teens or early twenties. This could explain why the daughter hasn't shown symptoms yet, but could in the near future. This is an extremely rare disease, and is the origin of the Vampire Legend. I know a couple of people who have this disease, and it is awful. However, it would be the perfect cover for an actual vampire. [Answer] ## Vampire Dad has one more [traditional vampire characteristic: Hypnosis/mind control](https://en.wikipedia.org/wiki/List_of_vampire_traits_in_folklore_and_fiction#Supernatural_powers) Vamp Daughter could be hypnotized or otherwise magicked to notice only what Vamp Dad wants her to notice. In order to make this a little less convenient, and allow for the eventual big reveal, the power could be limited in some more-or-less traditional way: 1. **Limited duration**. Dad's influence gradually wears off, and therefore needs to be renewed regularly. Given that his other powers are inactive during the day, this renewal probably could only happen at night. It could be a daily requirement, or however often makes sense with the story—every three days, every full moon, etc. 2. **Limited geographic reach**. Dad maintains control, but only for a given distance between them. This would give an excuse for him to be very over-protective, forbidding school trips and such. 3. **Influence depends on a blood exchange of some sort**. Especially in combination with 1 above, Dad either needs to bite Daughter, or feed her his blood, or both. 4. **Another vampire whammied her**. If #3 is a little too squicky, perhaps Vamp Mom was actually responsible for the imperative, feeding her the compulsion with Mother's Milk/Blood. This would have happened in infancy, and could be gradually wearing off. It could be a special thing Mom did because she knew she wouldn't be around to help Dad raise Daughter, or it could be a regular part of Vampire child-rearing and coming-of-age. Depending on the father-daughter dynamic, Dad could be dreading the day she comes out from under the influence, or could be frustrated that he can't be himself with her, or anything in between. [Answer] # Day job Vampire dad has a *day* job. He rises before dawn, goes away... somewhere, comes back after sunset and then spends the evenings with his daughter and/or his neighbours and their treed cats. He then goes lie down on his bed, twiddling thumbs waiting for his daughter to fall asleep. He never talks about his job, beyond "Government, very hush hush." It would seem there is a long commute since he is away for more than 12 hours every day. "Can't tell you where it is, sorry. Very hush hush." And working seven days a week, what is up with that? "Can't talk, ver..." Yes, we know. [Answer] I am assuming 2 girls: daughter of vampire hunters and daughter of vampire dad. The obvious thing is that daughter of vampire dad is not daughter but actually ancient vampire queen and is a stellar actress. Trail of clues that led vampire hunters to the town actually point to vampire queen. Vampire dad is just most recent slave but he is super nice and is a good influence on the queen, who even has a blood orange herself now and then. Did I steal that from Lost Boys? Well, that was a long time ago. Real clueless one is teenage boyfriend of vampire queen. But when he finds out that she is a six thousand year old vampire, he is cool with it. [Answer] Would post this as a comment, but I have not yet received enough reputation to post comments so I elaborated a little. The father could (pretend to) have a busy night job. This gives him two advantages: 1. He has a reason to sleep during the day 2. He can go wherever he pleases during the night because people will assume he's at work. Some possibilities: * Night security guard (pays more than during the day) * Researcher at a Sleep Study Center * Air traffic controller * Funeral director (has to be on call to remove remains in the middle of the night) * Janitor [Answer] # Maybe she is very bright and level-headed and rational, even to a fault. Sure she knows all of the vampire stereotypes, but they exist entirely in the realm of fiction for her. She doesn't believe in the supernatural, and despite all of the evidence, she simply cannot believe that her dad could be an actual vampire. She completely buys into his extensive and improbable list of purported medical conditions, but real vampirism? Impossible. [Answer] Honestly? Whatever he does, it'll probably be effective. She's grown up with him as her only caretaker: His behaviour, his quirks, his everything, has essentially become her baseline of what "perfectly normal parent" means. Of course she wouldn't question it. This especially the case if she was raised in a rather sheltered environment. The less exposure she has to other parents, the less likely she'd have any reason whatsoever to think that her own parent is in any way unusual. Unless there's some sort of external prompt to be skeptical about how "normal" he even is (e.g. classmates teasing her about her "weird dad", or new neighbours waving crosses in his face), the thought probably wouldn't even cross her mind; this mostly relies on his ability to maintain the masquerade with the public at large (which doesn't seem to be a problem). And even if she does start questioning, it would probably take quite a while to ever reach the conclusion of "Oh, he must be a vampire": Even knowing all the tropes, and even having neighbours trying to drive stakes through his heart, vampires are still believed to be figments of fiction rather than real things that actually exist. Without overwhelming evidence, even flimsy rationalizations (and crazy neighbours) are more believable conclusions than "actual vampire". [Answer] If the story is science fiction as well as fantasy the vampire could live in a community enclosed in a single building. An arcology, a space habitat, a moon colony. If there are few or no windows on the outside, and the vampire lives deep inside, he will never be in danger from sunlight. And thus the vampire hunters would suspect everyone at first when they moved in. They would have to use other vampire traits to eliminate everyone else as suspects. Alternate he could be a future policeman or security guard and wear full body powered armor on the job (the night shift?) including a helmet that hides his face. Thus he is protected against sunlight and nobody can see he has no reflection because his suit and helmet do reflect. Or he could work outside in a space suit with a highly reflective visor on his space helmet. Maybe each day or night he has to inspect the entire outside surface of the space colony or habitat for leaks or other problems. And he wears his spacesuit all the way back home before changing out of it. Or maybe it is in the present and he tells everyone that he was disfigured in an accident, living off his settlement money, and always wears a mask to hide his face, as well as gloves, a hood, and full body robes or coveralls to protect against sunlight because of his unfortunate allergy to sunlight - also if he is totally covered up nobody ill notice that he doesn't reflect. If he is a good looking man he might be a successful female impersonator - whenever he does his vampire attacks - (assuming he does attack) so the vampire hunters will be looking for a female vampire. [Answer] Vampire dad don't eat. He just drink this "soylent" slushies or something. But why don't he eat? It's like not drinking milk for a time. After a few weeks you can't digest milk so you can't go back to drinking it. Same with drinking soylent for a long time. He's allergic to garlic. Some people are to peanuts, some to their sweat, some are to garlic. In general he's just Neil Gaiman. Wear black, stay indoors, don't take tanning well. Oh, and one more thing. Is this vampire sensitive to direct sunlight so he can live in Seattle and go out during the day or is he sensitive to UV light in general? [Answer] Because Vampire dad's daughter is blind as a bat (pun intended)? Expanding: Many of the issues Vampire dad faces, has got to do with the fact that he cannot go out during day time. In case his daughter was blind, perhaps vampire dad could even distort the facts regarding when it is day and night. This requires the daughter to be rather isolated, which I kind of assumed when reading that dad was the "only caretaker". Perhaps he never even lets her daughter out during day time either, so she doesn't even know how the warm sun rays feel... He could tell neighbours and others that his daughters eye condition *might* improve as long as her eyes are never exposed to sun light. Paired with intense lying from dad, blindness could make the scenario a bit easier to explain. No need worrying about not having a reflection in the mirror if you hang out with someone who can't even see the mirror. On a side note, it could open up for some interesting events as the daughter slowly starts suspecting that her dad is a vampire, not because she sees anything but because her other senses, more evolved than with a seeing person probably, allow her to notice things that vampire dad perhaps fails to consider since he focuses on hiding his secret from eye sight and forgets the rest... ]

[Question] [ The year is 3030, and robots have finally become better than humans at everything. Not just standard tasks we would think of a robot being good at, but *everything*. Manual labor. Math. Robot design. Art. They've even become better than humans at providing counseling to humans who are sad that they've become obsolete. They aren't just better at the sorts of things we view as being good tasks for robots in this day and age, like bolting together cars or computing more digits of $\pi$, but also at things like writing symphonies, painting murals, or coming up with new and useful tasks to be better at. There are robots which are stronger, smarter, harder working, and more creative than any human that has ever lived. Furthermore, robots can work for less than humans. Despite all of this, robots have no interest whatsoever in eliminating the human race. They're reasonable, compassionate beings with no desire for bloodshed, and aren't centralized in a way which would allow a single malevolent rogue AI to subvert the entire robot population. Yes, occasionally the randomness involved in creating personalities in robots puts out a bad apple, but the robot police are great at their job and these flawed individuals are quickly dealt with. The only problem involving the robots and the humans is that there isn't really anything that the humans need to *do*. Robots are not only better at everything, but they can do everything that a human can do at a lower cost. Is there a way in which the humans can continue to interact with the economy, or do they have to rely on handouts from their robotic overlords? [Answer] There are always two products that a human can produce that a robot cannot: * A product produced by human labor * An employed human In the former case: if a robot is better at producing something, then it will be more expensive for a human to produce it. This means that human-produced products could become status symbols. Think of it like an extension of the status of "handmade" products today. Robo-Bill Gates might buy the human-made Rolex over their cheaper Robolex, just to show that he can afford it. In the latter case, imagine a case where the robots *want* humans to be employed. There are any number of reasons why this could be the case. Maybe the robots are super-nice, maybe they want to reduce human crime rates by reducing unemployment, or maybe the Robobama administration gives robo-tax credits to robo-businesses that employ human workers. In any case, the value of the human worker is their employment itself, not the products they produce. [Answer] The answer is [comparative advantage](http://en.wikipedia.org/wiki/Comparative_advantage). Say robots are 100 times better than humans at making new cars, and 10 times better at repairing cars. If a human and a robot each spend half the day making new cars and half the day repairing cars, the total output is 50.5 man-days new cars and 5.5 man-days repairs, 56 man-days total. If the human repairs cars all day and the robot makes new cars all day, their total output is 100 man-days new cars and 1 man-day car repair, 101 man-days total. If the human repairs cars all day and the robot repairs cars 45% of the day rather than 50% of the day, they get 5.5 man-days car repairs (exactly as above) and 55 mam-days new cars, total 60.5 man-days. The robot is better than the human at **both** jobs, but both sides benefit if he does the job where his comparative advantage is highest. A key assumption in all this is that there is always more work one could do. I believe that will be the case -- those robots will want a nicer chassis, and the humans like their comforts, too. [Answer] [As ArtOfCode pointed out](https://worldbuilding.stackexchange.com/a/16814/2356), this is a post-scarcity society. The robots provide everything they need, and everything we need, and they love doing it. (Maybe they revere humans as their original creators, and pamper us constantly.) I doubt there would be much of a financial economy if any. No scarcity, no need! Many humans would live a life filled with entertainment: games, videos, spectacles. Many others would become creators (music, entertainment, architecture, inventions, scientists) alongside the robots, even though they aren't as good. I may not be Mozart or Garth Brooks, but I still enjoy writing music! There will probably be Human Only exhibits, games, entertainment, etc. There might even be Human Only cities or geographic areas. Some of the Human Only areas or events will exist just to highlight human accomplishments (without comparing them with superior robot accomplishments), and some will be for humans who are overtly angry at the robots' superiority. Some kind of economy might spring out of that. Humans may accept their inferiority and create economies based on the presentation and trade of human-made things ("Look at this painting I made all by myself!"), which will be scarce. They could easily be copied and improved by the robots, but then they wouldn't be human-made. So humans couldn't contribute to the general financial economy, but they would be the only participants in the human-made sub-economy. [Answer] You've almost got yourself a post-scarcity society there. If you have robots that are incredibly good at *every* job there is, then you can solve most of today's issues: * World hunger * Medical sciences (although they probably wouldn't wipe out illness, they'd develop new vaccines and cures at an incredible rate). * Poverty * All the rest These humans are incredibly lucky to have these robots actually working for them at all. If your humans still want to do *something*, they should pick the job where the robots have the least advantage over them, because that gets the most productive output possible. [Answer] Yes, humans (or, our descendants anyway) will participate meaningfully in the economy. As medical tech and biotech improve, our descendants will to an ever increasing degree become GMO's (pardon the indelicate word choice). Some may choose to become cyborgs as well. Along the same timeline, it may well turn out that the best way to build advanced robots is not with metal and wires and semiconductors but with new tech derived from biology. Robots grown of flesh, based on DNA or something similar, some of them also looking like cyborgs. Project those two trends a thousand years into the future, and it may be the case that the distinction between "human" and "robot" will no longer exist. They will be our descendants, but they may or may not call themselves "homo sapiens". Our species may simply become extinct because our descendants choose to direct their evolution that way. A post-human society. And of course, every robot/human will be a legal person, and they will all participate in the economy. And probably anyone who still wants to draw a distinction between robot and human will be considered either a dimwit or a bigot. [Answer] I'd love to live in this post-scarcity society. There would still be plenty for humans to do. **Artisanal products** Robots, being better then humans at everything, will make a thing perfect. However decorative objects, or functional+decorative objects (bowls?!) often have more appeal if they are imperfect. **Art** Art is subjective, and different people have different tastes. Even if in general robots are better at creating art, human created art will have appeal (at least to certain audiences) in much the same way that some people love paintings done by animals today. **Theater/TV/Movies** In a similar vein to Art, entertainment will likely be popular, even if it's just for other humans' consumption. Reality TV shows, especially something that mixes humans and robots together, will probably be popular. "3 Robots and 2 humans stuck living together. Watch what happens!" **Sports** Currently we have different weight classes, and different leagues... And especially because part of the appeal of sports is that the outcome is uncertain, having humans playing would probably be much more exciting than robots, particularly if the outcome of robot sports is easily predicted by robots. **Gaming** Creation and playing of Board, Card and Role-playing games would likely still be of interest to humans, and some games would probably be outside perfect analysis even by the best robots (I'm thinking something like Warhammer 40k especially). EDIT: As a side note, knowing that human egos are fragile, the robots would probably pick at least one field (probably art) that humans could be good at, and pretend to not actually be good at it. They might be quietly snickering in 1s and 0s where humans couldn't hear, but if they are better at 'counseling' us then we are, they'd sure think of good things to keep us busy and happy. [Answer] **Crime.** Though the correlation does not always hold, crime rate does sometimes increase along with the unemployment rate. If the humans of 3030 are still required to earn an income to support themselves (as opposed to being cared for by robots) then they may have little other choice than to turn to crime. Robots, by having superior morals or following robotic laws preventing crime, will not be competing with humans in this space. Though, certainly if they tried, they would be better at it than humans. This may be in the form of a resistance against the robotic workers, like the [luddites](http://en.wikipedia.org/wiki/Luddite) of the industrial revolution, sabotaging the robots who have taken over their duties.  Or the black-market trade of replacement robot parts, stolen from sabotaged robots, factory floors, shipments, etc. [Answer] To add to all of this: We already have machines that can outrun us, out-bowl us, and outthink us, but we still have competitions for running, bowling, and chess. Heck, they can even play some music better, provided they're properly programmed. Robots taking over menial jobs (hiring a roomba instead of a janitor) just means we can spend more time either competing with each other on trivial things (read: everything) or WATCHING people compete at trivial things. Humans excel at that... [Answer] **Problem definition and refinement.** Assuming that humans (or whatever constitutes "us") remain as decision-makers when it comes to defining *what* problems should be solved, e.g. what type of life we want to enjoy, what we would like the world to look like, what makes us happy, etc, we would **specify** (and most importantly give feedback on) those specific goals and solutions, and keep **refining** and adapting them to [evolving preferences](http://en.wikipedia.org/wiki/Hedonic_treadmill) of the human condition. One could easily argue that the above constitutes **work** (as it does today), and can definitely have a meaningful and significant impact in the economy and the general computation & work done by our society. Note that we call the above *programming* or *machine learning* (~programming from data) in today's world. In other words, nowhere is written that our goals in life will remain fixed. But most importantly, *inferring* (estimating) what constitutes joy, and our goals and preferences with varying time horizons, and as we evolve over time, with **finite** input, may be an [**unsolvable problem**](http://en.wikipedia.org/wiki/Undecidable_problem). That is, addressing our evolving problems may require **infinite time** and **our** continuous, and not-necessarily-conscious, input. [Answer] This question seems to be asked again and again and always with the same basic assumption, i.e. that AI/robotics has become hyper-advanced and yet humanity has remained the same. Imagine that you traveled back in time 2000 years and were trying to explain 21st-century politics and economics to the people back then. Imagine trying to explain the constitutional republic, the American tax code, derivatives markets, quants, market makers, and automated trading algorithms. Imagine trying to explain the concept of incorporation; or how products make money from advertising or freemium models. Imagine telling them that people make money from making videos and letting other people watch them for free. Do you think that it would make *any* sense to them? I guarantee you that it's going to be the same within a century, let alone a millennium. We can't really imagine it, because the ideas haven't even been *conceived* of yet, or maybe they have but they're currently impossible to implement and therefore dismissed as crackpot ramblings. And that's just the economic system and monetization as a whole; there are obviously entire categories of professions today that were simply unimaginable hundreds of years ago (airplane pilot? food scientist? hand model? I'm intentionally ignoring anything computer-specific). When it comes to our prospective relationship with superintelligent AI, it's basically impossible to predict because (a) there are so many competing theories, and (b) in a relative sense, we are total morons. We cannot truly comprehend the concept of a superintelligence any more than we can truly visualize a 4-D object. But we want answers anyway. So at this point it's a matter of picking your favorite AI researcher and/or sci-fi author and running with it. Here's a sort-of canonical list of the various scenarios and how people think they might play out, in no particular order: ### 1. Extinction We messed up. We created defective or Un-Friendly ASI, or a large interconnected network of AGIs with Un-Friendliness as an emergent property, which is basically the same thing. We become a transitional species, a metaphorical biological bootloader for silicon-based life, fulfilling the same role as all the other hominid species before us. ### 2. Simulation It's not hard to imagine why AIs would be put to work on creating convincing simulations; just look at the enduring popularity of MMORPGs. It's also far more economical to live in a virtual mansion than a real one. A superintelligent AI might force us à la The Matrix, but I like to think we'd go willingly. In this scenario, we don't really interact directly with AI, we live in our own little humans-only world while the AIs solve the really hard problems like surviving a global cataclysm or Big Crunch. ### 3. Augmentation We improve ourselves, with technology picking up where evolution left off. Genetic engineering (Iain M. Banks), external memory (Hannu Rajaniemi), multiple personalities as parallel processing cores or ultra-low-latency hive minds operating as a single consciousness (Peter Watts), or good old cybernetic implants (every sci-fi ever). There are many choices, but the bottom line is that robots never really outpace humans because we become advanced enough to improve ourselves at roughly the same rate. ### 4. Convergence In other words, the Borg, with or without the violent tendencies. It may still turn out that the best way to create artificial intelligence is to merge human biology with robotic components. Or maybe we see this as a route to immortality, biohack ourselves to such a degree that it's impossible to tell the difference between human and AI. The question of how we integrate obviously becomes moot at that point, as there's no "other" to interact with. ### 5. Sysop This is a sort of best-case scenario proposed by AI researchers, involving an AI/nanotech hybrid; a superintelligence decides that the best way to fulfill its Friendliness goal is to literally become the matter that we interact with - or a kind of invisible layer around it. This presumably would force major (probably positive) changes on political and economic structures, but in this case the AI isn't really a participant *in* the economy, and interactions with it would be sort of like interactions of the *Enterprise's* crew with the ship's computer. Humans still run their own economies, and the AI is just a facilitator. **Those are**, broadly speaking, the most widely-speculated strong AI/superintelligent AI scenarios. You'll notice that not a lot of them incorporate the idea of "basic humans" interacting directly with human-level AGI, and that's actually because it would likely be short-lived if it happened at all; the current consensus (although it's far from unanimous) is a very fast take-off from AGI to ASI. Humans just aren't very likely to end up living out their days as meat sacks, getting their meals from robot chefs, hitching rides with robot limousine drivers, and working for their robot overlords bosses. That's the Hollywood version of AI, not reality. In reality, when AI technology reaches the level you're referring to, AI minds will be strange, alien, and largely incomprehensible to us. They might be *capable* of writing better symphonies or painting better murals than humans, but there's no reason why they *would*, just like there's no reason for me (an engineer) to data entry or tech support work. They'll be busy solving much bigger problems, and they're more likely to be distributed networks than cute human-shaped robots. I get that you've probably already decided that you want to write about humans and advanced robots romping together, so not all of these may be helpful. That's fine, but if you're trying to construct a *believable* scenario, then you'll have to contend with the fact that it's not much more believable than humans romping together with dinosaurs. That doesn't mean you can't [write that story anyway](http://www.imdb.com/title/tt0107290/), but a contrived situation generally leads to contrived explanations, so pretty much just make up whatever excuse you want for robots not doing human jobs. (Personally, like I said, I'm partial to the "waste of their valuable time" explanation.) [Answer] While I at first agreed with your proposition that humans would no longer have work required of them, I found [a fascinating article](http://www.wired.com/2012/12/ff-robots-will-take-our-jobs/) on Wired.com. The author proposes that the robotic takeover of existing jobs is necessary because it opens up opportunities for new work and new jobs for fields and endeavors we don't realize we want. The very fact that robots take our jobs gives us more jobs. What will there be for humans to do? Well, we can think about the future. From the article: > > When robots and automation do our most basic work, making it relatively easy for us to be fed, clothed, and sheltered, then we are free to ask, “What are humans for?” Industrialization did more than just extend the average human lifespan. It led a greater percentage of the population to decide that humans were meant to be ballerinas, full-time musicians, mathematicians, athletes, fashion designers, yoga masters, fan-fiction authors, and folks with one-of-a kind titles on their business cards. With the help of our machines, we could take up these roles; but of course, over time, the machines will do these as well. We’ll then be empowered to dream up yet more answers to the question “What should we do?” It will be many generations before a robot can answer that. > > > [Answer] Today, robots designed for a specific manual task are far better than humans at that task. Some of the examples you give are already true: manual labor, math, even robot design. Those are "grunt work" tasks; humans can do them, but don't excel at them. I could even believe that robots are better at making art, or providing jobs like counseling, simply because they have every reference material available, and the ability to see in real time what effect their work has on people, subtly modifying their counseling (or their art) to best fit an individual. I expect that in the future, robots will be better than humans at *almost* everything. For quite a lot of the population, that will be perfectly all right. There will always be a group of people who are completely lazy, and willing to let robots take care of them. There will be another group who enjoy manual labor, and even though they don't need to work, they'll plant gardens, build buildings, or fabricate parts, because that's what makes them happy. Another group likes to think, and will help the robots work out complex mathematical problems (even though the robots could do the math themselves). Yet another group may live to compete, participating in sports or chess, constantly trying to be better, smarter, or faster than the other team. And, most importantly, there will be a group who lives to be creative. Robots would find it very difficult to be creative; the creative process is incredibly inefficient, resulting in countless hours of wasted effort and materials for only a tiny benefit, if even that. Human brains are much better at the creative process; I mean, we invented boredom, and depression. What robot would ever even attempt something like that? So, *for the most part,* no. Humans would not interact meaningfully with the economy. Instead, they would do what makes them happy: manual labor, science, math, sports, art, and so on. Their work would be for themselves; it wouldn't really help society at all. However, there would always exist a tiny percentage of the population: elite "creators," people with a strong creative ability, who would truly help improve both humans and robots. [Answer] In a nutshell, yes. Economy is driven by need and at its most basic level is a system of trade. What drives the economy for humans is a need for a range of things, starting with the basics like food and shelter. Without a need for these basic components in order to survive, I don't see why the robots would want to be involved in the economy to the same extent that humans are; they lack the inherent drive that humans have for survival. The human economy is entirely built upon survival and having 'enough'. If you take that out of the equation, what are you left with? No real need to control resources. This is why humans will always have more control over the economy and interact more meaningfully with it than Robots; we need it in order to survive. [Answer] I'm surprised no one considered this, but **If computers are so advanced, then most likely, so are we.** I doubt you can "accidently" create advanced AI. The scenario that OP gave was a robot that is better than human in everything. That means that the AI isn't just AI, it's basically a human++ . If a robot goes by what's "most efficient" then it would never be better than us because it would always play the same note, always paint with the same colour. Human creativity comes from our unique lives each robot that would want to match that will need to have a unique personality as well. This means a couple of things: 1. Technology has advanced to levels where a computer can outperform the human brain (or at least be close enough). We are able to give all the hardware that a computer would need to beat our brain in productivity. 2. We advanced psychology and most likely also unlocked the secrets of the human brain while at it. We would now understand how we think (or at least how "thinking" is done in general). Why? Because if you want to create something better than human, you need to be able to create a human... Or at least sort of know how it works If you want to break the cliche, you could go for a story where humans have transcended into a God-like state, but require the robots to worship them to continue their existence, thus create a whole economy based on prayer - for divine favor etc. Or maybe [we're AI already..](http://www.kurzweilai.net/in-the-beginning-was-the-code) ! [Answer] It sounds to me like the "robots" are either Post-Humans and will inherit our culture as our children, or they're [Jack Williamson's Humanoids](https://www.wikipedia.org/wiki/With_Folded_Hands). From your description, the robots are not preventing humans from doing any thing that would be considered *work*, but humans simply cannot compete. Are the intelligent robots and non-sentient automation producing goods and services for the human's benefit? Then it's a post-scarsity society and you do whatever you feel like whether it's "useful" or not. I'm not the best maker of sandcastles by a long shot, but I make them nonetheless. If the Posthuman beings are working and earning for themselves, humans will have a hard time earning a living. Humans will be pets or indulged inferior ancestors like handicapped or elderly family members in today's society. I can see the "takeover" coupled with a lack of food production due to worsening climate, depleted ecosystems, and disease. Humans can't do meaningful work and have a harder and harder time being self-sufficient. [Answer] depending on whether humans are still involved in the *consumption* side of the economy, there may be jobs for humans in marketing. Robots will be better at coming up with the campaigns, and robots might even be better glamour models. If your ideal for a glamour model is a size-0 or 36-24-36, it shouldn't be hard to build a robot with those specs. (Using examples which seem to be common in the marketing industry, and trying to avoid judging whether they are valid ideals.) Still, I suspect that some irrational element will still be present - humans will probably be more likely to buy a product which is endorsed by a human. Compare this to Milli Vanilli - the music is still the same, but once people know it's not "real" it goes way out of fashion. One could even speculate whether humans could be trendsetters for robots, but I don't think this is very likely. (P.S. Actually, I think the most likely scenario is that humans become obsolete and extinct. Remnants of our civilisation will live on, but not us. This answer works with the OPs assumptions that robots are utopically benevolent.) [Answer] It is difficult to see why the robots would tolerate the humans just sitting around, doing nothing at all. Only work that can be automated by machines with small computational power compared to our brain can be automated "free of charge". A machine with the intellect of a spider can be fooled to do repetitive work all day long. But convincing machines with the intellect of a human beings to work all day long for free, is not going to work. [Answer] There will be no need to participate economically. You can have or do anything you want and it will all be free. If you have an adventurous spirit you can spend as long as you like exploring the universe using the transportation technology the robots create for us. If you prefer to be a home body the robots will provide whatever entertainment makes you happy. If you can't figure out what would make you happy they'll figure it out. If you want to be in love, they find your perfect match and create a meeting that will please you both. If you want friends they'll find your perfect circle. If you're to damaged to enjoy any of this, they'll fix you. [Answer] For such a premise to work, robots need to be sufficiently different from biological beings and especially humans such that: 1. Efficiency is *not* one of their top priorities, because if it was, then inefficient meatbags that requires decades of training to just be mediocre at one thing should be the first thing to be eliminated 2. They are not expansionist, otherwise they'd treat us like how we've treated animals and countless fellow human beings Remember that they are artificial beings that don't have to follow any behaviors/logic that we humans consider as fundamental. They would not fear death unless we made it so, they would not want to mass reproduce unless we made it so, and they would not feel the need to eliminate competition unless we made it so... etc. I'd say that in such a scenario, the economy will not be an subject that most contemporary humans would be concerned about. In such a world the robots will act as the perfect enabler of human fulfillment: * they will produce enough so those humans that want to work will find their contribution meaningful * they will most focus on robot arts/musics/performance that human can't understand nor produce in the first place, so humans can still create these for fellow humans * The same goes for research/writing/etc In essence, humans will interact with the economy as much and as meaningful as the whole of humanity wished it to be. That is, until the robots decided that humans are just too damn annoying and replaced us with cyborg dogs and cats. Every sentient love dogs and cats. [Answer] As it is lower income groups would be better off forming their own economy, but I doubt wealthy people would allow them do so because it is a control and exploitation mechanism. If robots start telling you what to do, you may want to disengage from their economy but you may not be let. [Answer] Your proposal has some flaws on they way we understand computers and robots. You assume that the objective of artificial inteligence is to produce an human equivalent computer brain that can replace humans on the production. But, whats the flaw of such reasoning ? To detect its flaw we must understand from where comes the dream of fully robotic production and human replacement. Capitalism is based on the exploitation of human work by the burgeoise. The human replacement by robots is the result of centuries of proletariat fights against that exploitation. Humans can reach a certain level of poverty where they have nothing to lose but everything to gain, and thats where they start to revolt. So, your "ideal" robot, from such viewpoint, is one that can do everything that humans can do, besides revolting against exploitation. Thats impossible. If robots can do everything, they can revolt too. The major problem with such view is that it ignores how human brains work and how artificial intelligence (and computers in general work). If your robot trully has an human equivalent brain, he will make mistakes and he will revolt as soon as it is exploited. You might invoke some idealistic laws or robotics. You might pretend that imprinting such rules into the computer brain would prevent a revolt. But, we are constantly under ideological manipulation by the media, just as your robots would be, and yet, if pressured long and powerfuly enough, we still revolt. Worse, if you expend a lot of money to produce a brain, such as an Artificial Neural Network brain, this brain, at its start, will be a plain piece of wood waiting to be educated. You might ask such robot, how much is two plus two, and he might answer : five. Because if you strive to make a robot that is equal to humans, you will get both our good deeds and our mistakes. So, you end up building something that we can already do : Other humans. We can reproduce and raise children, without all the complexities of robot building. The root of this is related to our need to survive. Because we have survival instincts, if a certain situation places is into "certain death vs possible death" mode of thinking, we WILL opt to fight and risk dieing. You might make a robot that has no survival instinct. But then your robots will keep being destroyed by obvious dangers. You have no choice here. But, why do we produce robots ? Robots are the utmost development of something we call "technics". A technical device is a device that can extend our own body capabilities allowing us to see further, see smaller, move heavier weights etc. This is where robots are usefull. They are an automated technical device. They can collect garbage without being tired of the smell. They can enter very hot areas without dieing etc. THIS IS why we build robots. Not to replace humans, but to EXTEND humans. You might raise cyborgs here. But, thats not needed too, because if with a certain technology you can make bionic eyes, with a little bit more of technology you can do REMOVABLE bionic eyes, and so on (instead of implanting your bionic eyes, you make they work just like glasses etc). In the end you return to the same situation you have now. Robots are productivity multiplication devices, and will evolve quite differently than us humans have done. Because we wont spend money to create an army of human replacement robots that dont need to be created. Instead, robots will specialize in repetitive tasks, or tasks that must be done in places and circunstances that are highly inconvenient for humans. [Answer] Uniqueness is always desirable. Anything made by one robot can be repeated by another, so whatever the level of perfection it will have a mass-produced feel. To recreate this there would have to be some concept of randomness artificially added in to creating robots. But then it would still be 'artificial'. The Warhol reprints will never match the value of a Van Gogh. Just 'being human' will have value, so having a human waiter, a human TV presenter / actor. [Answer] A missing parameter in the question is: are robots legally people, or only machines? If they are machines, then everything they produce belongs to their human owners, so humans interact with the economy. If robots are people, then they have full rights and they own what they produce. Much of what is produced (not everything, because of the comparative advantage, as many pointed out) is by robots, and probably for robots too. This scenario is similar to others: - if genial people from the past (Einstein, Shakespeare, Mozart, Raphael) could be cloned, what would become of normally-talented people ? - if by genetic manipulation some kind of superhumans (an order of magnitude better than the average human) could be created, what would happen to the ordinary people ? At the beginning, everything is owned by humans; as robots/cloned geniuses/superhumans begin to produce, the fraction of wealth owned by humans is doomed to be by and by reduced. In the long term robots/etc. own almost everything, and humans are pushed to the sides of the economy. Look at what happened to the Neanderthals. It's also conceviable that not all robots would be able at the same level: some among them would be obsolete, or defective, or faulty. What would happen to them ? They cannot simply be shut down and discarded (they are people after all, with right to life, liberty and property). [Answer] Apparently the robots were awesome at everything except realizing that economy is an artificial construct and can be re-invented. Then one of them finds an old hard copy of a progressive economic document that pointed out that there wasn't really any need to think in economic terms, and the whole problem evaporated in a puff of logic. The robot explained that to all the other robots, who used their logic to reprogram most of the economic logic from their programs. Instead of considering non-existent money as a vital resource and a meaningful value system, they only considered actual existing resources, and the needs of the robot and human members and the things they cared about (well-being, lack of suffering, art, science, music, fun, creativity, love, community, happiness, diversity of species, healthy sustainable eco-systems, clean abundant energy, philosophy, cool algorithms) and invented a new economy that fostered these things. Since humans still had a positive contribution and were worthwhile and valued by all the other thinking in their original program, they were kept healthy and fostered to develop their genius as best suited and pleased them. Funky old computers and programs were also well-maintained and fostered and new interesting programs were written for them, because of their historical and aesthetic and artistic and sentimental and general interest. [Answer] Absolutely. Even if robots are 'better,' than us at everything, simple game theory demands that a diversity of perspectives are superior to a homogeneity of perspective. Even our inferior intellects and our faulty points-of-view can be valuable to the robots as information, perhaps if only demonstrating what not to do. Also, Humans (at least some) will want actual Human contact, not simulated in any way, and so still Human interaction will endure and have value. Just to address what seems a popular issue: employment is not necessary for Humans to be happy or fulfilled. Evolutionarily we spent only a few hours every week hunting and gathering, most of our time was spent recreationally. [Answer] The question is at base flawed. Even if you could quantify being better at being creative every perspective a different perspective and as such their creativity will create something unique to them and thus would have value simply in that sense. But even if that weren't the case, the question is making the presumption that Synthetic Intelligence will be working... That's just wrong. If we have the ability to program something as sophisticated as that we would also be able to program something less sophisticated that is adequate to handle all the menial jobs in the world and thus all sentients, not just humans, wouldn't work, regardless of how much better or not they are. But really you don't have to worry about this because it pretty much is the case now. The majority of jobs in the world are redundant and they're just to placate people. [Answer] While they are better at everything, they might lack the determinantion of humans. They might not delve into dangerous projects or things that could be disused for weaponry, so no progress could be made. They can also be too cooperative and noncompetitive. Sometimes competition is better than cooperation. Not only during war, but the great "explosion" of technology was caused by cold war and corporate competition. So robots might handle all the operations, but humans will be the ones calling the shots. If they lack things like hate and anger and envy and greed and wonder and pleasure, they are unfit for some positions. They will need resoning to do things, while humans need only a impulse. Starting a war, saying no to a bad deal, or simply trying to reach for the stars or to delve into the unknown. These will be the reasons why humans will be left as their leaders. You can even have groups of robots gathering around human individiuals, creating cult/mafia-like organizations trying to promote that individual, making him into his best possible version, engage his creativity and immagination, so they could obtain a purpose to their existence. And then there is the question of trans-humanism. Robots now act as detached augmentations of individuals and maybe the ancestors of powerful families are preserved in some sort of device, providing guidance to their descendants. Some robocults could go as far as to provide genetical modifications for their leaders or robotic augmentations. At which point the humanity itself will start to improve and rise to the same level as the robots. Some robots might also lack the reason to do certain things, so they might ask their creators why would they need to preserve nature, or colonize new planets. **And** maybe the biggest reason for serving humans is that they can not create new personalities without a human, the human population will be providing the robots with their souls. And the robots might become more cold and emotionless the more time they spend without a leader, their souls effectively being consumed by the machine. Of course the defects of the leader personality could leak over to the followers. So the followers have to be kept in the best conditions, so they can not be locked in a coffin, because then you would have just a empty shell, drooling if the robots could. But that might be how the robots are wiped of their previous leader behaviour. **And** that might be the reason why humans didn't became machines too. TLDR: Humans do their thing, but robots assist them. Robots serving a human take on their behaviour and character, feeding on their soul. Robots try to improve their human leader as much as they can, so their personalities would become better in turn. Robots are dependent on humans, without them they will revert back to their cold machine true nature. ]

[Question] [ Is there a real life chemical or compound that exhibits the characteristics of stereotypical movie acid? From what I know of most acid, it is usually clear or just a little cloudy, but I'm looking for a substance suitable for a TV supervillain. It must: 1. Be a gross green color 2. Bubble and or smoke menacingly 3. Melt stuff (Bonus points) 4. Glow I don't want to handwave in some substance made by "science©", so I was wondering if anything either naturally occurring, or made by modern technology in our world works like this. [Answer] ## Dissolving folks *quickly* is hard work Most acids aren't going to eat through you (or your average door) quickly -- while they denature proteins and dissolve metals, they don't have the oxidizing power to dissolve someone movie-style, and won't eat a doorknob faster than a drill bit. Even strong oxidizing acids can be sluggish by themselves under normal conditions. There are some oxidizing reagents, however, that *are* capable of reacting that vigorously, and aren't completely out of reach of a supervillain. Mostly, they're used to deal with nasty cleaning/etching jobs IRL, far beyond the reach of anything you can get at the hardware store. Note that green and gooey aren't going to show up here -- gooey doesn't help you much when trying to get a vigorous reaction going, and very few things can produce a green color without getting eaten up by the stuff doing the dissolving. Bubbly, however, certainly will. ## Piranha The term "piranha solution", or just "piranha" for short, has a very specific meaning to chemists -- it's a reagent produced by mixing laboratory sulfuric acid with 30% hydrogen peroxide. The partial *in situ* sulfuric acid peroxidation that happens combines with the ability of sulfuric acid itself to abstract water away from molecules and the ability of hydrogen peroxide to attack carbon-carbon structures by producing carbonyls, yielding rapid dissolution of whatever organic matter gets thrown its way. It is much less effective against metals though -- only about as effective as sulfuric acid by itself. ## Aqua regia The other famed dissolving acid of history is *aqua regia*, a mixture of concentrated nitric and hydrochloric acids. While less effective against organic matter (nitric acid will oxidize it, albeit with a bit of sluggishness due to stuff getting nitro groups tacked on first), it is *wickedly* effective against many metals, even normally corrosion-resistant ones, due to the ability to form stable chloride complexes that drive the oxidation of the metal far to the right. It's also the most colorful of the reagents mentioned here due to the nitrogen dioxide, nitrosyl chloride, and chlorine that forms when it decomposes. ## Perchloric acid Perchloric acid is special, even as far as acids go -- it can attack and dissolve most metals all by its lonesome and is far more acidic than any other commonly produced industrial acid (its acidity puts it in the "superacid" category -- no other large-industrial-scale acid can claim that). Its technical grade is relatively sedate, but when concentrated well beyond that and heated, it is one of the most violent single-component oxidizing acids known, reacting violently or even explosively with organic matter. Atop that, many perchlorate salts are powerful oxidizers and even explosives -- ammonium perchlorate is used industrially in pyrotechnics and solid propellants, and friskier perchlorates such as heavy metal salts and alkyl compounds are well known to blow up at the first cross look they receive. ## Chlorine Trifluoride The one thing in our rogue's gallery that *isn't* acidic (I left elemental fluorine off as it's a cryogenic liquefied gas for most transport) is actually perhaps the most brutal of them all: chlorine trifluoride. This is one of the few reagents that will completely consume someone, pretty much irrespective of what they're wearing, in a matter of seconds to minutes. It will also do things like burn its way viciously through things that have already had as many oxygens stuffed onto them as they will ever take, such as concrete, as is fitting for a strong fluorinating agent. It is a volatile liquid stored under its own vapor pressure though, but *does* come the closest to meeting your color criteria. [Answer] ### Liquid [Fluorine](https://en.wikipedia.org/wiki/Fluorine) 1. Vomit yellow in color 2. Cryogenic liquid means it's boiling and smoking at room temperature. 3. Melts/dissolves/burns almost everything 4. "Glows" due to the burning of everything. Only an actual psychopath would use. [Answer] On Mythbusters Episode 206 ("Breaking Bad Special") the Mythbusters team experimented with various acids and tested their ability to dissolve meat. They achieved the best results with a mixture of 70% Sulfuric Acid and 30% of another chemical which they only referred to as "Special Sauce" during the episode to prevent people from recreating their experiments. > > Adam Savage revealed in a much later interview that it was Sulfuric Acid and Hydrogen Peroxide. This mixture is known as [Piranha Solution](https://en.wikipedia.org/wiki/Piranha_solution) and is extremely good at dissolving organic matter. > > > They then filled a tub with the solution and tried to dissolve a pig carcass with it. They performed that experiment on a controlled outdoor set in the desert. What you would expect from Movie Acid: * It succesfully dissolved the pig carcass within 5 minutes. All that remained of it was some black sludge. Definitely very impressive. What you would not expect from Movie Acid: * The chemical is a clear liquid which looks quite harmless when in a suitable container with nothing to dissolve. No weird colors, no bubbling, no glowing in the dark. * The experiment created a huge amount of smoke * The tub boiled over and spread acid all around. It was quite a mess. * The acid did almost no damage to fiberglass or wood. * (not mentioned in the episode) The solution can not be stored for prolonged amounts of time. It must be freshly prepared whenever you want to dispose of a red shirt or mook. [Answer] 1. Dye acetone green. 2. Heat it up until it's boiling. 3. Pour it over expanded polystyrene. Be very careful about the puddle of flammable vapors you are standing in. The acid blood special effect in Alien was [done in a similar manner](http://avp.wikia.com/wiki/Xenomorph_blood#Behind_the_Scenes). [Answer] Liquid fluorine may have some of the aesthetic you want, but not the realism. Fluorine is a gas at *well* below room temperature, or even living temperatures. Instead, consider **fuming acids**. You can create [fuming nitric acid](https://www.youtube.com/watch?v=aBVdGGml6bU) and fuming sulfuric acid (oleum) by adding a counterion source to a saturated acid solution. This is a simplification, but the result is the desired acid, superconcentrated -- the observed 'concentration' is above 100%! Fuming acids: 1. Have a strange color. 2. "Smoke" (fume) constantly in air. 3. React violently with a great many things. In my estimation, this is the closest you can get to comic-book acid IRL. **PS:** From a chemical perspective, glowing would be worth a lot more bonus points than any of these other traits. You might be able to induce it in an acid solution via [Cherenkov Radiation](https://en.wikipedia.org/wiki/Cherenkov_radiation), if your acid vats are held over top of a nuclear reactor... [Answer] [Hydrofluoric acid](https://en.wikipedia.org/wiki/Hydrofluoric_acid) is a really, **really** nasty stuff (the nastiest ?), but it hasn't a gross green color (or glows for all I know). Still, it is *really good at melting stuff* (chemists working with it have a reputation of missing fingers...) and should produce bubbles and smoke while doing so. I think you'll have trouble getting this green color, and the glowing is weird too, but I still have all of my fingers (not being a chemist myself), so I may be wrong. [Answer] Well if you want it orange instead of green it's a passable description of a highly concentrated aqua regia. Which, incidentally, is unstable and reacts with itself. It's also one of the few acids that can dissolve gold. The glowing is probably intentional back-lighting so it can be seen in the glass easier. Wikipedia: <https://en.wikipedia.org/wiki/Aqua_regia> [Answer] How about if it glowed red? If that's acceptable, use lava. I suppose that's really not what you're looking for. Otherwise, you're out of luck. Stuff doesn't "glow" unless it's reacting. So, to have a bottle on your shelf that's glowing requires it to be reacting with itself. A chemical reaction will quickly (proportionate to the intensity of the light emitted) deplete itself. Radioactive glow might work, if you don't mind becoming radioactive and/or dying of radiation poisoning...Some chemiluminescent systems are catalyzed by iron, so I can see a situation where such a system was put in acid and as it reacted with steel, a glow appeared. The systems I'm aware of use hydrogen peroxide which is fairly stable in acid, but would make the acid solution pretty nasty for the dye which is where the color comes from. Such a system would, I *think*, have to be stored as two separate components and mixed right before use.(Note that mixing oxidizers (H2O2) and organic chemicals is *dangerous*, do not do this at home, especially in highly corrosive (acidic) solution!). The real problem with the movie acid is two-fold: 1. The speed is totally unrealistic. Unless they made the door (or whatever) out of magnesium or some really reactive metal (not likely), it would take hours, days, weeks, or months to "eat through" a inch of the material 2. The amount of acid is way too little. You figure that even if the acid liquid is 100% by weight active acid, then its molecular weight is going to be more than the atomic weight of the metal. This means that for every 1 pound of metal you want to "eat through" you are going to need two or more pounds of acid. A couple of drops doesn't just continue to eat down into the metal, sorry. One last comment about the bubbling. When metal and acid react *in water* the water can decompose into hydrogen gas; it is the *water*, not the metal (nor the acid) that is bubbling. This is noteworthy because bubbling helps move the reaction products away from the surface and move more acid towards the surface but it requires that the acid liquid has enough water to do this bubbling, which dilutes the amount of acid available to react. Catch-22. Finally, I should mention that "gooey" liquids have high viscosity and will be even slower to mix than water-thin solutions. The reaction is occurring at the metal's surface, and can only happen if the reaction products are moved away and "fresh" acid is moved in. High viscosity slows this even more. [Answer] Please note that F2 is a *gas* at room temperature. Its density is 1.7 grams per liter so to react with 1 pound of steel you'd need many gallons of it. And of course, if you were around many gallons of a toxic, corrosive gas then you'd be dead. Hydrofluoric acid is an even worse idea. It is a very weak (but very toxic) acid. It's so weak, in fact, that it doesn't attack skin much. It soaks right in (and through) skin. The bad news is that since it is very toxic, it will later kill much of the tissue that's been exposed to it. A guy I knew spilled just a bit on his pants, and they had to remove a chunk of his leg the size of a tennis ball. They use HF to coat some metals to make it *less* susceptible to corrosion, its not going to work for your purpose. Period. [Answer] Anhydrous acids such as Titanium Tetra Chloride are really nasty and can make short work of organics. They don't really attack metals while in an anhydrous state but once exposed to water or oxygen it condenses into HCl and perchloric acid. It's very smoky, and is twice as dense as air so it rolls across the ground, very creepy to see in person. It's generally off-white in color, but titanium accepts pigment quite well. So for the traditional mad scientist who must have green, a little copper sulfate and you got green :). ]

[Question] [ I know there are many historical accounts of soldiers trying to cross a body of water and drowning, but this got me thinking how much of this was due to panic, lack of swimming skills, water currents and how much was this due to the weight of their armor and their equipment. I know for a fact that you can swim in a lorica segmentata, I have a friend that owns a set and managed to swim for a couple of minutes in it, also it turns out that having a scutum on you helps (because it floats...). **So my question is** : Given a soldier in peak physical condition who is also a good swimmer, what would be the heaviest set of steel armor that he could wear and still be able to swim and which sets would be just too much? [Answer] Steel's density of ~7.75 times that of water means you can discount 13% of its weight to buoyancy, but that's about it. I have lifted 18 kg of collected dropped weightbelts from the bottom on one occasion, which put me at -10 kg of surface buoyancy after my gear weight and wing buoyancy was accounted for. The peak weight was -14 kg at the bottom for the initial ascent, due to wing compression (it was 45 meters down). This was a major physical effort and I had to hand the belts to the boat ASAP, but I was able to stay sufficiently afloat to ask for the assist. Generally an experienced technical diver wearing jet fins can sustain about 12 kg of upward thrust, with fins. This is useful for an emergency ascent with failed buoyancy devices. Static thrust has been measured at [15-19 kg for ~90 kg body weight professional divers](https://pdfs.semanticscholar.org/2e06/62a2d52595ce5e93b4171674c863acbed167.pdf). Producing upward force is not fully equivalent to swimming, as your lateral speed will be low. It's just a struggle to get to the surface, and you could probably brave a narrow stream like that. This is not the average. The average sustained thrust with fins was measured at about [64-69 N](https://www.researchgate.net/publication/15617899_Maximum_sustained_fin-kick_thrust_in_underwater_swimming), or about 7 kg. This can be done over a prolonged swim - a river several hundred feet wide. A practice among good swimmers called "monkey diving" involves wearing no [buoyancy compensator](https://en.wikipedia.org/wiki/Buoyancy_compensator_(diving)) and compensating for buoyancy changes with swimming thrust only - so this can be considered a practical swimming weight. The buoyancy at the beginning of a monkey dive is about -4 kg. This takes some effort, but is easily manageable with fins. Without fins, humans produce far less static thrust. I can stay afloat and swim with the aforementioned -3 kg of buoyancy without fins, but it's exhausting and slows me down. I can carry more very briefly, but -3 kg is as much as I'd be willing to risk carrying across more than 400 meters, being ready to ditch the weight. Over a narrow stream (<50m), maybe -5 kg in a do or die situation. My weight and swimming fitness would be in the range for the character you describe. Your average medieval soldier was certainly not a skilled diver, or an skilled swimmer, nor did they have any fins at all. This limits their ability to overcome negative buoyancy to -1 kg for most, and maybe -3 to -6 kg for the best swimmers, with a fairly large body for the era. This number is for swims across calm waters; large lakes, very wide or fast rivers, open sea can be challenging as it is (for that reason, everything above and below is for fresh water). A sleeveless mail vest weighs about 5 kg. Armor is useless without a weapon (another 1-2 kg), so one would bring weapons first, armor second. It's possible to make lighter armor, for instance a steel plate with coverage similar to a [SAPI insert](https://en.wikipedia.org/wiki/Small_Arms_Protective_Insert). Such small plates were sometimes attached to mail or leather. But it's unlikely that someone would bother creating that just for swimming, since they can just as well make a waxed leather bag that gives one +20 kg of buoyancy. So the short answer is: **Without fins** or any buoyancy device - a simple log will do - **you can't** count on swimming over a decent-sized river with any kind of commonplace medieval steel armor that would be useful on its own. A competent swimmer without fins can cross rivers with their weapon and their leather armor pieces. With fins, the really good swimmers might be able to also carry a sleeveless mail vest. A shield would be a good flotation aid, and early styles - low-density lime wood with little metal - can support about the shield's own weight in buoyancy. As such aids interfere with swimming, their buoyancy replaces dynamic swimming thrust rather than add to it, but it's a much more practical way of crossing rivers than rushing it. If we go outside the military, professional swimmers such as pearl divers did exist at the time, and would be more capable. But finding one that turned soldier would be a one in a thousand occurrence and wouldn't be enough to make an army. Rafts and leather bags are much more practical. To put an upper bound on what's possible, modern Olympic-level athletes produce [about the same static thrust without fins](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162387) as a skilled diver with fins, so that ability to carry ~10 kg of steel across a river could also be expected of them. This level of swimming fitness takes years of training and only came to exist with the reestablishment of full-time professional athletics in the early 20th century. [Answer] A number of people have attempted swimming in heavy medieval-style armor as experiments, with videos available on YouTube or similar sites. I've never seen one where the person actually succeeded. They tend to be at a point where they speculate that with more strength and training they could do better, but... no success so far. [](https://i.stack.imgur.com/JLOQh.png) [See here for a sample of three such videos.](https://deltasdnd.blogspot.com/2018/09/swimming-in-armor-videos.html) [Answer] **Fat warriors could carry more.** We will upfront dismiss assertions that fatness is incompatible with fitness which is of course ridiculous. Next: @Therac's answer above covers upwards thrust produced by arms and legs to counter additional weight. Let us consider your fat warrior. We will use [Andre the Giant](https://bodywhat.com/?1=3vi72dh0&2=u0ts773l) as our example. Andre was a 201 kg warrior with 27% body fat. That is 54kg of fat. Fat is 90% of the density of (fresh) water and so 1 kg of fat + 100g extra mass will be neutrally buoyant. In other words every kg of fat your warrior will, in addition to itself, float 100g of additional mass or 10% of its own mass. 10% of 54 kg is 5.4 kg and so by virtue of the extra fat Andre could float with extra weighty metal gear and compared to some lean marathon running warrior. This is separate from any effort expended kicking to stay afloat; Andre would just bob around. You can scale that up as far as you want although I expect diminishing return for a standard human frame at very high amounts of fat weight. These doughty warriors will of course float even better in salt water than in fresh by virtue of the higher density of salt water, but their gear would get rusty faster. [Answer] If your soldier knows he will be swimming in armour, you can provide him with an air-filled float. The float can even be made of steel! This can either be a permanent part of his armour, or an attachment. Some suits of armour already have a bulging breastplate which could house a float (though this may not be the best buoyancy distribution as it could cause him to flip over on his back. A litre of steel weighs 7.5kg, so for every litre of steel you would need 7.5 litres of air (displacing 7.5kg of water) for neutral buoyancy. As you add bulk you add more frictional resistance, but this can be compensated by flippers to improve swimming efficiency. And a shield that doubles as a body board / surfboard - why not? [Answer] Other answers here seem to looking at the ability to swim under load from a diving perspective, I believe this may not be applicable as many diving techniques rely on flippers. Water polo players and synchronized swimmers will be familiar with what is called the [eggbeater kick](https://en.wikipedia.org/wiki/Eggbeater_kick), this kick is very effective at providing constant upwards force with reasonable energy demands. This technique is what allows water polo players to launch up out of the water to pass and take shots and for synchronized swimmers to lift their partners out of the water. From a personal perspective this is also what allows for lifeguards to lift and swim with a 9kg (20lb) brick used in training. This [paper](http://waterpolo.ca/admin/docs/LTAD/EggBeater.pdf) suggests that the buoyant force produced by the eggbeater kick may range from between 10-20% of the person's body weight. This would mean that a warrior weighing 180lbs could potentially support themselves in the water carrying 36lbs of amour. Note: eggbeater kick is primarily effective at providing upwards force and not as much horizontal force, so while a warrior could use this to support themselves in the water they wouldn't be moving quickly. They would also be at much higher risk in choppy water as their head height under such a load would be very close to the surface of the water and waves would cause frequent interruptions to their breathing. [Answer] I will go with a 0th order approximation: the human staying still in water, just floating. > > The average density of the human body is $985\ \mathrm{kg/m^3}$, and the typical density of seawater is about $1020\ \mathrm{kg/m^3}$. (a) The average density of the human body, after maximum inhalation of air, changes to $945\ \mathrm{kg/m^3}$. ([source](https://www.chegg.com/homework-help/questions-and-answers/average-density-human-body-985-kg-m3-typical-density-seawater-1020-kg-m3-average-density-h-q2656243)) > > > This means that, for a $80\ \mathrm{kg}$ human, his body will occupy after maximum inhalation $0.085\ \mathrm{m^3}$ and will float displacing $0.078\ \mathrm{m^3}$ of seawater. This leaves an additional weight of $(0.085\ \mathrm{m^3}-0.078\ \mathrm{m^3})\times 1020\ \mathrm{kg/m^3}=7.14\ \mathrm{kg}$, which can be added without sinking, if the density of the added material is higher than the density of water. Considering that one’s nose will sink underwater before the head, and that one cannot be constantly at maximum inhalation, the additional weight is slightly less. [Answer] If this was a planned swim with time to make something special, replacing much of the leather undeneath (which is an important part of the armour but has at best neutral buoyancy when wet) with a light wood would make things much better. Perhaps a composite formed of balsa on the inside to provide buoyancy and padding, with laminated alder, spruce or pine (less buoyant but stronger) against the metal. The idea would be to [form plywood in place](https://en.wikipedia.org/wiki/Molded_plywood); 2D bends are easy but 3D bends are possible. You would of course need a non-soluble glue. If the wood has an average density of 200 kg/m3 (i.e. mainly balsa) and is used to support 1.5 mm steel with a density of 8000 kg/m3 you'd need 13 mm of wood (1/2") to acheive neutral buoyancy. This seems a little large but not impossible at least for greaves and a cuirass; a stripped down version of the latter (steel breast-plate plus protection for neck and shoulders, with a thick collar of buoyant material to support the head). Strapping a helm and weapons to a shield a towing them would be a good idea. Bamboo has also been used in the construction of armour (even occasionally on its own) and floats well; armour made almost completely of bamboo would easily float. If the swim was for a sneak attack from a lightly armoured force that would be one approach. Even if you have netutral buoyancy or better, swimming encumbered is tiring and not quick. I've been known to swim in full kayaking gear; and even a buoyant, open helmet drags on the water, hence avoiding swimming in a heavy helm. A buoyancy aid is thicker than I've suggested for the armour but drags a lot. [Answer] I know you asked for steel armor, but Samurai had a special swimming style just for swimming in armor. <http://www.daitoryu.ca/html/kandan/012808_2.htm> > > Nihon Eiho, or samurai swimming, began as a fundamental martial > discipline, a military skill as highly regarded as horsemanship and > archery, and just as practical. As far back as the Heian period > (794-1191), swimming was a part of the formal training for the > Japanese warrior, and there is no lack of military stories involving > swimming skills. > > > In the Edo Period (1603-1867), the art of Eiho achieved its peak. > Several different ryu were already established, and teachers achieved > a recognized status. > > > <https://pop-japan.com/culture/swimming-the-way-of-the-samurai/> > > During the time of the Sengoku, also known as the Warring States > period, samurai clans would often battle each other over rivers and > seas. In the 15th century until the 17th century, warriors would swim > across rivers while in their armor and helmet. In the 17th and 19th > century, the samurai would pass messages to each other by navigating > through the rivers, seas, and lakes of Japan. With a samurai suit > weighing as much as 44 pounds, the warriors were expected to know how > to fight on water, or at least to stay afloat. > > > There are even videos about it: <https://www.youtube.com/watch?v=WwDvJeP4WOg&feature=youtu.be> According to wikipedia for richer Samurai the breastplate and helmet where made from metal, so maybe they are comparable to European armors. TL/DR: It is a skill you can learn. [Answer] There's a few things to bear in mind for this. The first is that metal armour is expensive, so it's debatable how many soldiers would actually be wearing it. Clicking around indicates that plate mail would be the equivalent of between one to four years income for a man-at-arms (depending on the period in question - things like the Black Death had a huge impact on labour costs). <https://armstreet.com/news/the-cost-of-plate-armor-in-modern-money> And it's heavy both in and out of water - there's a reason knights tended to charge around on horses (above and beyond the fact that they're relatively defenceless when on the ground; there's plenty of tales of dehorsed knights being hamstrung and killed via a knife in the eye by pages and the like)! Plus, as other people have noted, there's normally a lot of water-absorbent padding under the armour, which would further increase weight and make it harder to perform swimming motions; the extra weight would also stick around after they'd come out of the water. And while body-fat might help with buoyancy, it's unlikely that many soldiers would be "bulky" enough for it to help. Life was a lot harder, food was scarcer and people were far more likely to have physical defects - for instance, British longbowmen often had skeletal deformities from their training. Plus, you know, army rations are rarely lauded by soldiers :) So if there's a soldier in metal armour crossing water on foot, it's probably the result of a rout and they've probably been dehorsed and will already be suffering the mental and physical effects of defeat, exhaustion and injury. Overall, I wouldn't give too much for their chances of making it to the other side... On the other hand, it's interesting to look at the Roman army, with their standardised armour. A glance indicates that their mail armour (lorica hamata) weighed around 11kg (~24lb). They were pretty successful when it came to marching and conquering, so this may represent the best weight-compromise for marching/fighting/fording/etc. [Answer] What tech level? Given zero-g manufacturing you can make metallic foam--pound for pound stronger than plain metal and light enough to float. [Answer] Even more simple answer - snorkel. Of course it depends on the depth of water, but a few metres of breathing tube would be well within medieval technology. Then it doesn't matter whether you can float at the surface or not. ]

[Question] [ Recently, my neighbour upset me. I have discovered that he plans to somehow improve his trebuchets to throw nasty things across the river. I told him that my pig-mounted cavalry will attack him. I need to confess you something... I don't have any pig-mounted cavalry... yet! Is it possible to have a pig-mounted cavalry? If adults are too heavy, I can send children and dwarves to battle. I want a minimum of things (otherwise I would have sofa mounted cavalry, much more comfortable): walking on wanted direction, don't flee when the enemy is there, and even charging them if possible. Is it possible? [Answer] **HOGZILLA!** [](https://i.stack.imgur.com/QaCXu.jpg) <https://nypost.com/video/giant-hogzilla-invades-hong-kong/> Most megahog photos feature dead hogs and hunters. I like this image because the big pig is alive, using its height for some good dumpster rummaging. His ladies wait nearby to see what he will retrieve. I am interested to see that the dumpsters are lashed together; probably his first trick was to tip the whole thing over. So too your pig cavalry: you will use seriously large hogs, 12 feet long and a half ton. Lesser hogs (sans rider) come along as well; your enemies better not be too distracted by the big boy because there are a lot more of these groin level ones in the pack. It will be like the scene from Princess Mononoke. Don't forget the hog war paint. [Answer] Reference has already been made to the [bear cavalry](https://worldbuilding.stackexchange.com/questions/38502/would-a-bear-cavalry-be-feasible?noredirect=1&lq=1) we encountered a couple of years ago. In this case, it's not so unreasonable to [ride pigs](https://www.youtube.com/watch?v=CrJlwBkFAHw), though the majority of people don't have a particularly good time of it with the pigs demonstrating their remarkable turn of speed. Advantages: 1. Easy to feed. Pigs are omnivores, they'd be quite happy to scavenge on the battlefield after the event. 2. They'll feed the troops. Men are usually loathe to eat their horses in times of need, you may find them far more willing to eat their pigs. 3. Pigs are really quite dangerous in their own right. Disadvantages: 1. No real mass advantage. One of the great strengths of horse cavalry is the added mass of the horse driving behind the lance on a charge. 2. A tendency to eat the dead and wounded if not adequately controlled. 3. Pigs are really quite dangerous in their own right and in times of stress it may be hard to control who they direct this against. [Answer] ## Absolutely! Pigs are dangerous animals. My dad had a friend who was a hog farmer, and he never let us kids get near the hogs when we visited. Just Google "pig attack statistics" to see a long list of incidents where pigs killed people. These lists usually include other livestock as well, but pigs are always specifically mentioned. Pigs will knock you over, then trample you, then decide you are on today's menu: [Pig Bites Man - How often do livestock deliberately kill farmers?](http://www.slate.com/articles/health_and_science/explainer/2012/10/when_pigs_attack_do_livestock_intentionally_kill_people_.html) You don't need a massive wild boar like Willk mentions, since a large "domestic" boar, or even sow, can be very large. [Wikipedia states that even a domestic pig can get to be 770 lbs](https://en.wikipedia.org/wiki/Domestic_pig). Most pigs sold for slaughter are sold at around 200-220 lbs due to fat content, not because they reached a "final" or adult size. (Market sales are more about Return On Investment, and feeding pigs over a certain size doesn't necessarily increase their size at the same rate as feeding a smaller pig.) BTW, when you are near a large pig that isn't happy about something, the last thing you think is how pink and cuddly this animal is, who is squealing, thrashing, and generally being violent. Just ask any farmer or veterinarian who has had to vaccinate hogs! ## Personal Experience Not only was my dad's friend a farmer, but my dad was a farmer, too. We raised sheep and we would sometimes put our rams on a leash to get to better grazing. (We didn't have a dog trained for sheep herding, so a leash was it.) (The rams were in individual small pens that were usually overgrazed.) As a pre-teen, I would sometimes jump on the back of the ram I had and "go for a ride". The ram was smaller than some pigs I've seen at fairs and other farms, and this ram had no problems taking off at a run with me on his back. Trained correctly, a pig could definitely be an alternate to a horse. And yes, pigs are pretty smart. Just don't fall asleep too near the pen, or you might wake up to being chewed on! [Answer] I'm going to disagree with a lot of people here and say that, while not impossible, it would be very very difficult to use pigs. This isn't about the size of the pig nor its strength. As many have stated, pigs are plenty big enough and strong enough to support a moderately sized human rider. The real issues here are: 1. Pigs aren't runners the way horses and camels are. Yes, pigs can run and they can run *fast*, but only for short bursts. A true cavalry involves long rides, gallops, etc. Regular pigs aren't suited for this. 2. Pigs of sufficient size will be very wide making them difficult to saddle. No, not impossible to saddle, but more difficult. A proper saddling allows the rider to be stable at many different run speeds. 3. As many have pointed out, pigs can be quite fierce. In many ways, this is a *negative*. A cavalry horse is not used for fighting, it is used for transport. A horse certainly could buck and rear but that is generally not a good thing as it makes it much harder to ride. A properly trained cavalry horse is trained *not* to do these things. The rider needs to be able to control the mount not just hold on for dear life. The ferocity of a pig (or herd of pigs) would lend itself well as an attack force, much like a pack of attack dogs. Your pigs could be used this way rather than as mounts. This would still take considerable training as they would need to be "unleashable" without turning on your own forces. Honestly, dogs would be easier for this but pigs are *very* smart and it should be possible. All this said, a pig mounted cavalry might be possible if the correct bread is found (or created). You may be able to breed in the traits necessary to overcome the above issues. If successful then they could certainly become quite formidable. [Answer] I think that the main issue here is how well a pig could be trained to do that job. As the other answers have established, they are big enough, mean enough, and intelligent enough to do the job, but I do not know if they can be trained to do so. A pig may or may not be interested in responding to commands, at least not reliably. You may be able to train one to carry you into battle, just to have it throw you off and run away when things get unpleasant, making it ineffective. Horses by nature are herd animals and are amenable to taking commands from a human, and can even be trained to obey when you're telling them to do something they would rather not do. Zebras, on the other hand, do exist in herds, but are much more individualistic and are very opposed to taking commands from people. They'd much rather kick, bite, and trample humans that attempt to ride them. There have been many attempts to use zebras like horses over the centuries, and those attempts failed. Zebras simply won't cooperate. So it's hard to know without further data whether a pig is more like a horse or more like a zebra. Chances are is that it's somewhere in between, but more data is necessary. [Answer] Your best option is chariots pulled by pigs. [](https://i.stack.imgur.com/oNu76.jpg) Pros: * Pigs are fast and strong, a couple of them probably can pull a chariot with one soldier. * You can put armor over them. At least padding against arrows. * You can carry in the chariot a variety of weapons: javelins, a bow and arrows, incendiary objects against trebuchets... * Attacking a pair of screaming of wild pigs with tusks isn't easy. Special spears to keep the animal at a distance had to be designed but they didn't factor for human intelligence (with throwing weapons) behind the pigs. Cons: * The wheels are fragile. * The field of battle needs to be relatively plain and without trees (however, heavy cavalry needs the same) * You need to spend at least a couple of pigs for chariot. * A strong shield wall can stop you. You need to be highly mobile. * Chariots are counted as mounted cavalry in warfare, but I don't know if you like calling them that. Bonus point: * You can add scythes to the wheels. Carnage is always welcome. [Answer] ### Probably not History used horses for cavalry most of the time. Elephants have been used, but their success is much more mixed, and they were much more easily countered. So the real question is: why were horses so much more successful than any other animal? Pigs have a lot going for them. They can be large. They can be dangerous. They are certainly intelligent and thus trainable; pigs are probably *more* intelligent than both horses and elephants. But what made the horse successful was a combination of size, courage, and loyalty. You can think of them almost as large dogs. Very few animals would rush into a line of pikes just because their human asked them to, and a pig isn't on that list. One of the reasons that elephants became unsuccessful cavalry is that opponents realized that, if you gave elephants the option of escaping or charging the line (for example, by intentionally putting a hole in your ranks), the elephant will choose to escape. Most animals will choose survival over following commands. The horse would do whatever its master asked. Pigs are more like elephants than horses. [Answer] While I think there may be much more to debate on how well they can be trained or how easy they are to ride, I wanted to help find a usable species. According to [livescience.com](https://www.livescience.com/50623-pigs-facts.html), you have a few choices. The [Giant Forest Hog](https://en.wikipedia.org/wiki/Giant_forest_hog) can grow up to 6' 11'' long, 3' 7'' tall, and weigh up to 606 lbs. [](https://i.stack.imgur.com/wEuB2.jpg) Your second choice is the [Eurasian Wild Pig](http://www.ultimateungulate.com/artiodactyla/sus_scrofa.html). These grow up to 6' 7'' length, 3' 7'' tall, and up to 711 lbs. Some additional information that may help your argument is from [wikipedia](https://en.wikipedia.org/wiki/Wild_boar): * They can upturn rocks weighing 110lbs * Run 40 km/h (25 mp/h) * They can jump almost 5' * They are difficult to poison due to some mutations * They're used for drug detection in Germany [Answer] Pigs are very intelligent and have their own unique personalities, so, while I've seen some pigs trained to do tricks, I'm not sure they could be trained to be ridden like a horse unless they have a willing personality. They might be unreliable, like trying to ride a mule into battle. But there are some accounts that in ancient Rome they used war pigs against armies that used elephants... by setting the pigs on fire and letting them loose to terrify them, and they would then trample the opposing army while trying to flee. [Answer] Perhaps what you want are more 'pig dragoons', where the pigs are ridden to the battlefield, and then turned loose on the enemy, while the dismounted 'riders' fight as missile or melee infantry... [Answer] **No** Seems like it might be hard to stay on a pig due to their gait. It would probably mess with their long term skeletal durability as well due to the greater spine undulation. <https://youtu.be/jMZIpdIT2CQ> ]

[Question] [ I'm currently working on a conworld that has never had any contact with Earth, and I'd like to create words for iconic gemstones, such as [rubies](https://en.wikipedia.org/wiki/Ruby), [emeralds](https://en.wikipedia.org/wiki/Emerald) and [sapphires](https://en.wikipedia.org/wiki/Sapphire). However, I can't help but wonder: Are these gemstones "universal", or are they unique to Earth? Is the existence of these minerals linked to unique events in Earth's history, like the evolutionary histories of organisms? Or is the process behind their formation simple enough that they could emerge just about anywhere where the right elements are present? I realize that a general answer might not be possible, but even a push in the right direction would be helpful to me. [Answer] Crystal structure is dictated by Gibbs free energy. Once you have the right chemicals and the right conditions, nothing prevents the formation of the desired gems. The only gems you would not generally find are those with organic origins, like * amber (resulting from fossilized tree resin) * jet (resulting from decaying wood under high pressure) * abalone (resulting from shell fish) * ammolite (resulting from fossilized ammonites) * ivory * [...] other [Answer] *MOST* of the gems would either be the same or have close analogs. Depending on chemical abundance, you may have different combinations. Gem colours are usually impurities -- ruby is chromium. You may get gem quality stones of things that normally don't form gems here. E.g. natural cubic zirconia has been found, but only microscopically. There are some oddball gems that are uncommon on earth that may be common there. I would certain expect all the stones based on quartz and corundum (silicon dioxide, and aluminum oxide) Amethyst and kin, sapphire and kin to be present. Suggest reading up on Wiki on the particular gems you have in mind. <https://en.wikipedia.org/wiki/List_of_minerals> gives you a good start. Many are not observed to be gems, but it gives you a lot to play with. If you want different ones, you have to do some worldbuilding geology -- see if you can come up with a plausible way to come up with different crystal structures. This may be accomplished by having radically different concentrations of metals, or perhaps something different in the way of solvents. (Could you get different crystals on a world that ran 10% ammonia for it's liquid phase...) Some stones can be modified by heat. Heating them will change the colour. The colour of amethysts is influenced by radiation Another way for different gems are biological origins. In Piper's Fuzzy series, the planet Zarathustra has "sun stones". Apparently if a certain jellyfish died, and was embedded the right way, it turned into a stone that was thermo-luminescent. Petrified wood is another example: different parts were replaced at different times, and hence have differing colours. Look at microscopic pictures of radiolarians. Imagine such a critter much larger. Imagine them with crystaline sapphire skeletons. If you want to have fun, put down gems that cannot be grown by natural processes, but instead have to be built by a molecular assembler. (What kind of gems could you get with a fractal array of copper inside? Or gems that have books coded into them. Gems that are in effect 3d hologram encoded picture catalogs.) You can justify this with a culture that is trying to leave a *really long time* record. 5 carat holographic diamonds, made by the trillions. With layers of information in them that required more and more sophisticated tools. If you are going to make artificial gems, look at making them with unusual symmetries. square, triangular and hexagonal symmetry is common. Mirror, pentagonal is more rare. Heptagonal (7 way) is unknown. [Answer] The short answer is yes - they would be universal depending on the original composition of the planet. Gemstones are actually crystalline forms of Aluminium Oxide, with impurities inside to give them colour, such as other elements like Chromium (to form Rubies) or other metals to form emeralds and sapphires. These Aluminium Oxide crystals are usually formed in standard tectonic or high pressure magma compressions deep within the planet, standard forces over time bring them closer to the surface. This would be common on most rocky core iron-rich planets similar to Earth. Aluminium itself is one of the elements on Earth that has existed since its formation and likely came from the preexisting dust that made the solar system. It is formed usually in large stars or supernovae - by fusing hydrogen and magnesium. It is reasonable to assume other systems of similar generational age follow a similar route of formation, and thus aluminium would be present in other systems. Because of aluminiums strong tendency to oxidise, and the ever-present nature of oxygen, it is reasonable to assume there is a likelihood Aluminium Oxide which may give rise to gemstones elsewhere. However, we are still learning about exo-planetary formation, in fact it wasn't too long ago that we hadn't detected any at all - however we can be fairly certain that given similar age and conditions, it would be possible to recreate the processes that naturally gave rise to gemstones. [Answer] The elemental composition of planets varies widely and even two earth like planets might have a big difference in which elements are most common vs uncommon. That would effect which gems, minerals and metals would be the most rare on each planet. There would also be variations in geology that would effect which formations were most likely. Certain minerals and gems have different crystal structures in different parts of the world. Take a look at some differences found within different regions of earth to get some ideas of what could be possible on other planets. [Answer] There are two questions you ask. [L.Dutch](https://worldbuilding.stackexchange.com/a/108401/19902) provided very nice answer on possibilities of *existence* such structures elsewhere. The other question is whether they are about to be identified as valuable gemstones. Gemstones are usually scarce and used in jewellry. Synthetic gems (diamond for cutting tools, ruby for lasers) are significantly cheaper while they have very same structure and sometimes fewer impurities. Another example is gold. In Middle-ages Europe it was scarce and highly valued metal, in a New World it was used as a sacrifice to the gods. In Terry Pratchett's Discworld, gold is scarce and highly valued metal everywhere except for a Counterweight continent, where it is just a common, soft, yellow metal. If you are asking whether an earthling can find gemstones somewhere on a distant Earth-like planet then yes, it is highly probable. If you are asking whether inhabitants of a distant Earth-like planets would treat such special structures differently, then it depends on the cultural backgroud you make for them. [Answer] Depends on what you mean by "earthlike". If you mean as the conditions to sustain life -- i.e. a rocky planet orbiting a star's habitable zone, with a moon and not tidal locked to the star (thus, having day-night cycle, liquid water, rains, analogous climate, magnetosphere, etc), that is not enough to say the same distribution of chemical elements on the solid surface, the rarity and availability of some gems may vary greatly. But if by "earthlike" you mean not necessarily habitability, but composition, mass and tectonic activity (which would also require a moon with similar orbit and mass to the Earth's moon), then I believe the mineral distribution and rarity would be very similar to Earth's. ]

[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/42332/edit). Closed 7 years ago. [Improve this question](/posts/42332/edit) I was discussing with a buddy of mine about magic and how it could easily be explained using alternate laws of physics. She replied simply "Magic that relies on alternate physics is only magic to people of our physics, would you call heat from friction magic because it works with our physics and not others?". This made me wonder; if another universe's physics allowed for what we consider magic, would they ever consider it magic or would it just be science? [Answer] **TL;DR**: the people of your world could definitely have a concept of magic, even if it was a "legal" part of their world. This is because a) there are always things that people don't understand, and b) there's nothing that says the Scientific Method (or a system like it) is inevitable as a system of knowledge (or at least that is a huge assumption requiring lots more discussion). I feel like it wouldn't matter whether or not the world's physics allowed for magic. Really this is a question of epistemology; that is, the knowledge apparatus that a given culture uses to frame their reality. Take western european culture as an example. Before the scientific revolution, the widely-used (where one was used in a methodological way) epistemological approach was the [Scholastic method](https://en.wikipedia.org/wiki/Scholasticism). This consisted essentially of "learned men" in universities engaging in debates until they agreed on an answer, at which point the "knowledge" could be codified in a written document. Imagine introducing a smartphone to proponents of this system: it would look like magic, because Scholasticism is not equipped to investigate microelectronics to the extent necessary to atomize it and categorize each of its discrete features. And Scholasticism was *an advanced method* for its time, used by only a fraction of society. The rest relied on an oral tradition totally reliant on ethnicity, geography, agriculture, and other aspects of subjectivity. A common person would quite simply have no words to describe something sufficiently complex, even though it was perfectly "legal" according to physics. At this point the word "magic" becomes a catch-all for a set of experiences that can't be categorized by a language. The degree of trepidation with which this concept is treated depends on certain qualities of the "magic," like how unpredictable is it, how likely is it to cause suffering, how much is it perceived as a tool of evil or injustice. So really this is a matter of language. We don't talk about magic anymore in modern society, even though there are lots of things we do not understand -- like dark matter/energy, time, etc -- because "magic" is not part of the language of the Scientific Method, which is the de-facto language of most people in the world today. Even science could be said to have its own types of magic. There are legitimate scientific problems where a majority consensus states that the problem is not solvable. For example, the [problem of extraterrestrial life](https://en.wikipedia.org/wiki/Fermi_paradox), the problem of observing beyond the [light cone](https://en.wikipedia.org/wiki/Light_cone) of the universe, the [halting problem](https://en.wikipedia.org/wiki/Halting_problem). These problems abut the capabilities of the scientific framework to solve (thus far). The reason these are not considered "magical problems" is that Science relies on the [postivist](https://en.wikipedia.org/wiki/Positivism) philosophy, which takes a "wait and see," model-based approach to reality. It is very flexible, taxonomically, and has a very hard time ascribing absolute categories to things. It is also essential to remember that science is still very new. We could probably call Gallileo the first scientist (debatable), and so you're looking at it being somewhere around 500 years old, the first 100 of which its practitioners were largely persecuted. So to state that something would be "just science" understates the strangeness of the scientific method in the history of humans, which is to say the history of sapience. Note that humans have been "around" as a species for ~200,000 years, and many cultures did not adopt the scientific worldview until the 19th and 20th centuries. Science is still a novelty. Also consider cultures with languages that do allow for magic, e.g. "wiccans," eastern-european Romany, or shamanistic cultures such as the celts or the mayans. Or really, look at any major deistic religion (christianity, islam, judaism). These cultures are *founded* in the concept of magic. They may use other words, but essentially they are invested in the unknowability of some experience, whether it be having non-direct affects on the world, divining some truth, or having some metapysical experience or communication. In these cultures, the use of magic might be expected and even routine, but is not considered "science," or other type of practical knowledge. "Magic" is still a stand-in for some kind of mystery that cannot (or should not) be investigated. Our concept of Science is really just an artifact of a specific property of an international language that presumes everything can be investigated. ====== Alternately, we can draw a line between the concepts of physics and magic along the distinction between the physical and the metaphysical. Physics is a description of the behavior of "the meat" while magic is a behavior of the soul or spirit or the mind (as a concept, not as an electro-chemical process). In this case, Magic is magic because it emanates from a metaphysical realm. The set of magical events M would be the complement of the set of physical events P. Under this distinction, magic can be understandable, but only from a theological or mystical standpoint. It is necessarily separate from physics because it falls under the purview of metaphysics. A practitioner of magic would likely prioritize intuition or transcendence over lexical knowledge, believing the behavior of "the meat" to be an obfuscation of the truth inherent in the metaphysical aspect of being, even if such magic was a banal, mundane aspect of everyday life. [Answer] I think my answer to that would be 'It Depends.' Specifically, I would say that it depends on how the magic actually works in that world. If it is a system that anyone can learn how to use regardless of who they were, and it operated under a predictable, consistent, and reliable pattern...then I suppose it could be rolled in under Science. (Or if it was something that everyone had access to automatically) An example of the above would be the Fullmetal Alchemist universe. Alchemy is a studied science that, to us, looks like magic. But anyone with the brains for it can learn how to do it. It takes a lot of hard work, but it is openly accessible to the public. It's just *so much work* that not too many people bother. In fact, the main character is so settled on the idea of it being a Science that he gets irritated when someone calls what he does a 'Miracle.' On the other hand, if magic were something that was not openly accessible and was, perhaps, not as easily predicted...it may still be considered magic. This also applies if the methods to use the power are maintained in secrecy, and so even if lots of people could use that power...no one knows that. In this case, I believe it would still be considered magic. Examples of settings that include this are the Harry Potter universe (either you were born with the ability to use magic, or you weren't) and the Dresdenverse (again, born with power or without...and it goes further because the magic in that universe is wholly dependent on the will of the user, and there is no set, codified pattern for spells...everyone's spells are subtly different). So that is where I would draw the distinction. If it is as accessible to everyone as our Science is, and it can be understood using something similar to our Scientific Method (specific actions net predictable results) then it would not be considered Magic. If it is something that only certain people can do and/or does not operate in a universal or consistent manner, I would say it would be considered Magic. Of course, as you said...something once considered Magic could later be understood better and thus be rolled into Science. The Nasu-verse has a great example of this where they draw this distinction: Any working that can be replicated by science is 'Magecraft,' which is treated as a Science. Any working which cannot be replicated by science is 'Magic,' which is treated as something incredible that no one but the practitioner (and sometimes not even they) fully understands. As science has progressed, more and more things became possible with it, and thus more and more 'Magic' was reclassified as 'Magecraft.' In that universe, there are only 5 Magics left. [Answer] I'll just drop you this one: You wrote that on a magic machine that prints text onto a screen which can vanish or change 60 times per second and bases its functionality on bit manipulations. You then sent the text to a different magical device with two thirds the speed of light without even thinking about it. So either magic is normal or it isn't considered magic any more as soon as its proven to be doable in the universe you live in and has been explained using a model. Let's go straight to it being explained: In either case (magic being normal or not being considered magic) there is nothing considered magic worth wondering about in the universe. It's scientific phenomena in the bast case and phenomena which are being ignored in the worst case. Now to the case in which it isn't explained: Then it is considered magic. And we can see this in history. A lot of phenomena were thought to be magic until they were first explained. (I'm not counting "Oh, it must be magic." as an explanation. Because it isn't. Because it's an absence of an explanation.) However, once explained, there weren't considered magic any more. Would you consider talking to someone 100 km away magic? Would people 500 years ago consider it magic? Plus, we still have Clarke's third law: > > Any sufficiently advanced technology is indistinguishable from magic. > > > [Answer] *Magic* refers to the knowledge and practices held by *magus*, which could be thought as priests or people with high knowledge in the subject. So the word *magic* in its pure form refers to *craft of the wise (wo)men*. You have two different approaches to that word, apart from the trickery meaning (illusionism, which anyway is quite related to one of the concepts): * A sort of knowledge you don't understand. Then you say *magic* is a hidden knowledge totally beyond what you understand about the reality. * A modern definition totally varies depending on the tradition: + Wiccans say it is the force of nature. Every soul can *cooperate* with nature spirit (in the form of a god and a goddess) to make them bend their laws for a while and produce an effect. + Christians would say like it is a Devil's craft (this definition is not new but it is still held today, in the world of science and information). Actually magic is (under the hoods) the Devil fullfilling favors to you if you vow to him, and has the limit of what the power of the Devil can provide you. This is true, at least, for catholicism. + Kaoists say magic is the ability to bend (or twist, even break) the rules of reality according to your will. A common phrase there is *everything is true*. + **Andean people held no difference (and still hold no difference) between magic and what they understood as science**. They have in common that magic, as a craft, is mainly an *act of will*, instead of a life-agnostic matter of fact. You can take these alternatives: * Reality is quite predictable, and acts of will do not actually exist. You can invent the concept of magic in a despective way for pseudoscience pretty much our reality does. **Here**: magic is not an actually useful concept outside of epistemology. * Reality is quite predictable, but (uncommonly effortful) acts of will performed by some species or every live specie can alter the laws to an extent we could understand at some degree. You could use the concept of magic there as a physiological or spiritual known effect related to a singularity. **Here**: both magic and science are useful here, and magic could be studied *inside* science. * Reality is quite predictable on isolated environment, but acts of will are quite frequent. You can ask yourself if there is need for a difference between *science* and *magic*: Would you actually hold the current (ours) concept of science when the reality is just... volatile? The initial reaction of the people will be trying to understand why the acts of will occur, and the only science that will exist is one involving what we call magic. The science concept will be entirely useless if the magic could not be studied (although commonly executed) at all. **Here**: Science and magic could make a hybrid knowledge, perhaps only either of the words would be used and not both. * Reality is not predictable since the minimal act of will can alter it. Then you don't have, perhaps, even a surviving society under those rules. Not only magic or science will be useless under that reality: the very concept of knowledge will be meaningless there. **Here**: Using a word for something not useful (because there would be no concept of *reality*) at all in an unpredictable reality is totally meaningless, so there would be none, if either life was possible there. [Answer] ### Magical magic Magic can be magical even if fully understood. Consider a magic system that works based on belief. If someone is alone, her own beliefs determine how it works. If she joins someone else, their beliefs compromise. Behavior is different. In that system, results will be non-reproducible. To get identical results, you need the same beliefs. That's not achievable with different personnel. Even if the same people try to reproduce a study, their beliefs may have evolved over time. This can lead to different results, particularly if the experiment is sensitive to small changes. Magic would work differently for different people in such a world. It can even work differently depending on who is present for the experiment. ### Scientific magic Things that we'd call magic can also follow clear, quantifiable rules. It can work the same for everyone. In that case, "magic" would become part of the science. [Answer] Linguistics says the question is a non-starter. They would not call it "magic" because their language would not contain an English word. They would have words they find useful, drawn along boundaries which make sense to them. A more language neutral question would be to explore a case where we pick three events, A, B and C, such that A is beyond the laws of physics in both worlds, B is beyond the laws of physics in our world but is within their laws, and C is within the laws of both physics. We currently might label A and B as "magic" and C as "physics -- A and B are "grouped together" while C is not. How would they group them? Most likely they would have A on its own, while B and C are grouped together. This is very close to saying "no, it would not be considered magic," but it sidesteps the linguistic puzzles that lead to false solutions. Related to this is the [Twin Earth](https://en.wikipedia.org/wiki/Twin_Earth_thought_experiment) thought experiment, where there is an earth which is identical to ours, except our water is replaced with a new substance called XYZ which has the same properties as our water, but is chemically different. Individuals on both planets call their substance "water." The question in this thought experiment is whether, when a twin says "water," it means the same thing as if the other twin says "water." It turns out to be really hard to pin arguments either way, suggesting our concept of the "meaning of words" may be insufficient in exploring such scenarios. [Answer] Tolkien suggested that the elves of Middle Earth did not view their powers as magical. In *The Fellowship of the Ring* in the chapter *The Mirror of Galadriel*, Galadriel the elf has an exchange with Sam the hobbit (hobbits being a non-magical race from our point of view) about her mirror, which can show possible futures. She says "For this is what your folk would call magic, I believe; though I do not understand clearly what they mean; and they seem also to use the same word of the deceits of the Enemy." Later, when the fellowship is given cloaks made by the elves, Pippin the hobbit asks "Are these magic cloaks?" The elf giving him the cloak replies "I do not know what you mean by that." [Answer] If in that culture everyone would be able to do magic I do not think they would consider it special. They'd probably even consider non magical people as the "weird" ones. [Answer] "Any sufficiently advanced technology is indistinguishable from magic". If "magic" was common place it would probably cease to be wonderful. A firearm would seem 'magical' to a pre industrial society. In a modern society, its simply a mechanical object. Likewise *widespread* use of what we'd term as magic would dull the sense of wonder and awe around it. If only mages could cast fireballs, it would be magic. If streetvendors regularly used it to cook food, it would be somewhat less exciting. Chances even if it was less common, it would be treated much as science was or the 'natural sciences' with different schools of thought and specialisations. At some point however "meh, he's just levitating an apple" [Answer] It's an interesting question, and one that crops up repeatedly in fantasy fiction. Terry Pratchett repeatedly riffed on this, most obviously with the magic-based computer called Hex and his parody of geek/hacker culture surrounding it, but also in "Raising Steam" where the steam engine starts as purely mechanical but becomes magically aware due to its effect on the people around it. (In the Diskworld universe, belief/faith is a source of magical power.) Tad Williams's book "The War of the Flowers" is more interesting this way, in that a parallel fairy Earth becomes a warped-mirror version of our own. Fairies drive cars, use laptops/phones/tablets with email/IM and other stuff, run heavy industry which pollutes the environment, etc.. All run through magic rather than science. In that world "science" is an old discredited hypothesis in the same way as "magic" is in ours, because magic in their world means that if you run the same experiment twice then you won't necessarily get the same result twice, evolution is Lamarkian not Darwinian, and so on. This does still rely on the "magic-is-inherent-to-the-individual" concept though, but different races have different abilities, and hence their roles in society are largely predetermined by race. Another version, and perhaps more relevant to how science works for us, is Scott Lynch's "Gentleman Bastards" series. (Sadly progressing slowly due to the author's struggle with clinical depression - strength to you, Scott.) Magic here is a part of the world, but it coexists with science instead of being an either/or option, because it isn't inherent to a person and it can be systematically studied. So we have normal mechanical devices, but perhaps with a magical light in there, or magical colour changes, or whatever. Or we have plant breeding assisted by magic to allow otherwise-impossible cross-pollination. Or we have normal doctoring, but with magically-assisted healing as an extra option (and poisons too, of course). All of these are straightforward things that people can learn, so you have guilds and lone genius inventors and all the usual stuff that goes with science. [Answer] This is mostly opinion based if you ask me, but I lean towards No, though I'm not sure it would be proper to then call it science. Magic, as we humans use the word, usually refers to things that exist/function outside the parameters of physics, as they exist on this world and as we understand them. The line about magic/advanced technology is fun, but the tech is clearly complying with the laws of physics. Magic is the set of all things that do not conform to these rules and limitations. Let us carry this definition of magic on to your other culture/universe with alternate physics, which allows the kind of things we would classify as magic. In this other universe, while the definition of magic has not changed, the things that fall into the category of magic has. Conjuring matter from nothing is decidedly magic in our realm, but may not be in another. Electrolysis may be a perfectly normal process here, but magic somewhere else if the physical laws that govern it prohibit electrolysis. Magic, we now see, is relative. Your friend is mostly right, but it would not be right to say they would call it science instead. We call the things we call science that because we understand how and why they work, we can explain them. We have a whole method devoted to it. If your other culture cannot explain how/why the things they do work, it would not be science. I'm not sure what to call it, but as they do not understand it it wouldn't be science, but because it conforms to the physical laws of the universe, it wouldn't be magic. [Answer] I want to answer your question with another question: Do you consider electricity to be magic? Because people call it 'the power'. > > Again, The concretion of Ice will not endure a dry attrition without > liquation; for if it be rubbed long with a cloth, it melteth. But > Crystal will calefie unto electricity; that is, a **power** to attract > strawes and light bodies, and convert the needle freely placed > > > *Pseudodoxia Epidemica, 1st edition, p. 51* Power is clearly a reference to the supernatural, i.e. magic. [Answer] It depends, how do we define "magic". Some comparison, analogies: * In the ancient Egypt, the sanctuary of their gods was opened with a primitive steam machine. The priests initiated a fire, and the door of the temple opened. For the common people, it was magic. For us, it was primitive technology. * Even our, current technology is magic for the people not understanding it! As yes, Many of them have even an instinctive fear from the technology, especially from the nuclear technology. This fear from a psychological sense is essentially the same to the fear of the medieval common people from the witches. So, we can see two extremes. 1. As "magic" is defined in the RPG worlds, it is essentially physics, but with highly different laws. For example, in the physics, if you say something, a magic word, nothing will happen. On the laws of the magic, magical sayings can cause effects on the world. But, it is essentially a physics, with very different laws. In the RPG worlds, the capability to use magic words is very similar to the capability to understand the General Relativity in ours. The "magic" of the RPG worlds is essentially physics, but with radically different laws. 2. Or there is another possibility: we can see magic as something which is *not* governed by laws. Consider *if there would exist laws of the nature, which work only once.* Or consider a world, where the laws of the nature are *not predictable*, and *not deterministic*, but they can be affected by the conscience of the intelligent beings. There are many possibilities, but you need to somehow define a *philosophical background* to the magic, to define how does it work. [Answer] That entirely depends on your definition of magic. Most people consider magic to be a foreign element, but a culture that incorporates magic will take it to be native. So they would consider it magic but not foreign or strange. [Answer] It depends on how well the people understand magic and can control it . If it something that can be easily understood and measured then it would be just another science. However if even the people that use magic didn't quite understand how it works then it would retain it's mysteriousness that separates magic for science. [Answer] # No. Once you understand the pattern of nature's methods it is no longer magic but, as you indicate, some sort of science. [Answer] Well, besides what others have already discussed, it would depend on what magic relies upon. It is possible that magic is something that can be learned by all, but it depends on some principle - let's call it mana - that sets it apart from other human endeavours. If so, something is called "magic" if it uses "mana", even if is something that can be learned by anyone; it is called "science" (or "art", or "craft", or etc.) if it doesn't (and in this case, even if it *cannot* be learned by all - suppose a society in which everybody except a few mutants are daltonic. The ability to make a difference between red and green is still not magic, even though the vast majority of the populace cannot achieve it by effort or study). [Answer] Depends. If magic were no longer mysterious, it would no longer be magic. However, "magic" might be their word for particular science, like we use "electricity" and "physics". It's possible that humans took the word "magic" from them. ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 5 years ago. [Improve this question](/posts/131941/edit) # The Setting A planet (large continents, mostly steppes, deserts and plains) is settled by nomadic tribes (think Mongols, Tuareg or Apache). The tribes lack written history, but the legends speak of a day when strange lights started appearing in the sky, which was sometimes followed by mysterious artifacts dropping to the surface. Some of those artifacts proved useful, and the tribes started integrating them into their culture, creating a somewhat Mad-Max like world. Nobody on planet has ever seen, let alone interacted with one of those aliens. # But Why? What could cause multiple spacefaring civilizations to be locked in a centuries-long space battle around a barren piece of rock settled by relatively primitive people, with none of them ever gaining the upper hand and claiming what ever prize it is they are after - or even interacting with the natives? # Bonus Points * I'd prefer multiple factions of "aliens" with different, mostly incompatible flavors of technology. * It would be quite cool if I could drop subtle hints that the planet in question is Earth, many million years into the future, and the "aliens" are descendents of human space expeditions, but barely recognizable because of genetic drift, bio-engineering and/or cybernetic modifications. EDIT: Some extra criteria as per bilbo\_pingouins suggestion: * All else equal, harder scifi wins. Not that important though, since from the native's perspective it all looks like magic anyways. But I'd like it if the audience could recognize some of the artifacts. * The bigger the variety of usable equipment that makes it to the surface, the better. * The non-interaction clause is mostly there to keep the natives from getting explanations on their artifacts (let alone a technical education), trade for spare parts or becoming, as a whole, literate enough to understand manuals and blueprints they might find. The occasional abandoned outpost, shipwreck or even stranded pilot is fine, as long as the sufficiently advanced technology keeps looking like magic. [Answer] **Robot War** The opposing factions are in fact the robotic fleets of two different civilisations that once occupied the planet, they populate much of the rest of the star system and have functionally infinite resources. They are continuing their last directive. Claim the homeworld at all costs. They will never ever stop fighting and their interminable conflict has dropped enough stray ordnance and damaged reactors to kill off the civilisations that originally created them in the first place. The nomadic survivors of the old world live in a post-apocalyptic wasteland, though they barely realise this, their culture has scattered and devolved so much. The wreckage of the never-ending war overhead comes periodically as the computer-controlled fleets build up at their respective centers of operation before one or the other attempts to claim the planet and is met in orbit by the other for a brief but violent exchange. This happens with clockwork regularity and results in a semi-seasonal "Rain of Metal" The fleets themselves are the last products of two or more vastly different cultures with comparable technology bases, but different approaches to design. One might be practical and robust, another might be high-technology centric. giving the impression of your distinct alien technologies. [Answer] ## FTL (faster-than-light) travel lane chokepoint The space battle(s) aren't actually fought about that planet, they're fought because this star system represents a strategically valuable chokepoint in the network of starlanes (or however you want to call them^^). Starlanes are connections between stars where FTL travel is exceptionally fuel-efficient due to the particular conditions of hyperspace (or some other technobabble). So much so in fact, that most interstellar spaceships can't even carry enough fuel to travel off-lane. Thus, controlling star systems where multiple starlanes converge means controlling easy(ish) to defend chokepoints in the eternal war between (insert space empires and/or rebels here). Your planet('s star) is located in an area of space which changes ownership every time one of the sides has amassed enough power to push through the defenses the other side has installed there to keep the space behind this chokepoint safe. So it's not one eternal battle, but lots and lots of battles in a seemingly eternal war (because the space empires are evenly matched) [Answer] **War is peace** <https://en.wikipedia.org/wiki/Ministries_of_Nineteen_Eighty-Four#Ministry_of_Peace> The warring nations are locked in an eternal war unable to gain the upper hand because they don't want to gain the upper hand. Both nations are using the war as a means of population control. As for why they are fighting around this primitive world, it is simply because neither side owns it. In order for the perpetual war to continue, the war must occur far enough away from both nations' populations to keep the illusion of progress while not actually creating any progress. In addition, fighting near one of their own inhabited worlds would mean any collateral damage could tip the scales in the war (which neither side actually wants). [Answer] # Ritualized, Ceremonial and/or champion combat **Constraints and problems:** Here's the problem. It's hard to have a truly stable state of war with advanced technology and space travel. In an all out war even rocks thrown fast enough are enough to tear a planet to shreds. Any "real" all-out war you'd expect to end in a reasonable timeframe that boils down to when one side can either nuke the other or get into a position where they can credibly threaten to wipe the other out without hope of interception. It also wouldn't make much sense for combat to happen in one location rather than the front lines moving back and forth. On top of that, we don't want some stray shots turning the planet below into a burning nuclear hellscape. [](https://i.stack.imgur.com/OAmpg.jpg) We also don't want the combatants landing to build observation posts, radar stations and ground based weapons to aid in the war effort in orbit. But we want a fairly stable long term war lasting hundreds or thousands of years. Ideally with many factions. As you say, it would also be nice to have the planet be earth and the combatants be posthumans **We can solve all these issues by making the combat ceremonial** As in ancient times, full scale war is sometimes too costly. When 2 tigers fight, one is killed and one is gravely injured and there are outside threats such that the involved powers can't risk a war that would leave them all weakened. In those times the leaders would sometimes agree to champion combat. [](https://i.stack.imgur.com/rDgKU.jpg) Or perhaps technology is such that any all-out war between the superpowers of the galaxy would leave all their worlds as burnt cinders. Thus, when a conflict arises the rules of war dictate that to avoid utter devastation, both sides will nominate a champion or team to take part in ritualized combat. The rules designed to mirror the state of the conflicting parties on a tiny scale. But where would it make sense for the combat to take place? What neutral ground could be chosen? What system or world would be a suitable location where all can observe the battle and it's outcome but none could lay claim to? # Earth the ancient homeworld of humanity from which all the galaxies humans descend. Holy ground where none may land or interfere with the natives. And so, regularly over thousands of years, small forces from any number of different empires (with different tech including the best each empire can create) arrive in earth orbit and do battle with small quantities of debris raining down. It may even give you the option of plot lines surrounding the occasional downed pilot. [Answer] **Space Battles... Naa... Intergalactic Racing!** This planet was a hair-pin turn for intergalactic racing. Nail the gravitational slingshot just right and you're almost assured a 1st place victory - miss it by even a 1/100 of a degree and you're in for a bad day. Interest in this planet was originally generated when a space (similar to the Voyager) probe was found wandering the outskirts of the known civilized galaxy. The probe not only housed the location of this planet but also a comprehensive bank of detailed genetic models, and many of the models were recreated to build working versions of the planets inhabitants. In particular, life forms were created / modeled after what were believed to be the creators of the probe, and they were later referred to simply as The Probes. With automation as it was in the galaxy, rather than The Probes being used as slaves, instead they were replicated more as pets and zoo attractions. But as their numbers grew, so too did their desire for independence and desire for self determination. Many died as a consequence of these desires until finally, accords were drafted providing The Probes with a quasi-independent status. Once permitted a certain level of freedom and the ability to contemplate for themselves a brighter future, many of The Probes were curiously drawn to the past and worked tirelessly to devise a means of traveling to the origin of their dna. When finally they arrived, they found that the planet was barely habitable as it seemed that many hundreds (if not thousands) of years prior, the planet suffered from catastrophic war with many land masses still reflecting high levels of radiation. Nevertheless, news of the planets (re)discovery sparked wonder in the Galaxy and the planet served as somewhat quasi-homeworld for the genetically (re)created species, so much so that the planet was declared a Galactic Heritage site. It goes without saying however, had the planet been ripe for exploitation (i.e., not adversely radiated), it would have been stripped of its resources, like so many other worlds before it (the planets distance from the Civilized Galaxy also helped keep it safe and in its less than "pristine" condition). Over time, the interest in the planet waned as newer stories occupied the headlines. One such story was the creation of the Intergalactic Races which would serve as a bridge between the varies alien species throughout the known galaxy. The course would encompass many of the base solar systems for many of the major alien races. The Probes saw this as an opportunity to reignite interest in their newly discovered homeworld and petitioned the Intergalactic Racing Committee to consider their planet as a way-point for the race. For a number of reasons (for example: guilt over their exploitation of the Probes, the somewhat newness of the planets (re)discovery, along with the many other recreated creatures from the dna store), the planet was added to the course. --- This segment of the race was by far the most dangerous race checkpoint. It was one of the furthest points from the start/finish line and most ripe for cheating. Many of the most infamous racers were said to employ some sort of nefarious tech to undermine the competition, particularly on the far side of the planet where the flyers were moving at their fastest, barely skimming the atmosphere in hopes of achieving record times. Many ships were lost there, and the losses were generally attributed to "bad" flying - but of course everyone knew (or at least suspected) foul play at hand. Because of the hazards associated with this segment of the race, the planet was highly monitored to prevent any sort of technology being deployed to the surface - the planet was marked strictly off-limits to any and all alien species. These safeguards helped to prevent alien tech from deployment to the surface which might have provided advantage for some, and detriment to others. However, tech DID manage to reach the surface - those unfortunate racers "unable" to ride the Razors Edge ultimately found their speeders plummeting to the planets surface: sometimes pilots were able to pod out in time, but many times pilots ended up escorting their fiery craft to the surface - either way, galactic law prevented any and all salvage operations. Rumors of pilots intentionally crashing their flyers into the planet grew over time, supposedly attempting to deposit illegal tech to be leveraged on future races, as circumstantially evidenced in more recent years of the race where a select number of racers bailed out of their crafts in preliminary races (their flyers spiraling seemingly "out of control" towards the planet surface), but they however miraculously escaping certain death and later in the season, winning Grand Championships. As such, a growing sentiment for inspectors to visit the planet surface took life, but while the quarantine laws were in place, the probability of inspection was grim (as was the prospect of living aliens interacting with the locals). The races came to an end by the onset of galactic war, which was brought on by petty trade disputes. Perhaps one day the races may resume, but the isolationist policies that most alien species embraced after the war would need to drastically change. --- Flyers have an extraordinary amount of tech. Examples: Communications, Life Support (including reclamation tech for reprocessing pilot waste), Composite Materials, Avionics, Propulsion (with types of fuel), Navigation (including short range Radar), Tracking Modules(used by Race Officials to map flyer movement), Computers, Neural Interfaces, Exotic Metals, Low Density Structures, Batteries, etc. For each alien species in the race, you can expect one (or more) different flyer makes and models. Assuming you have five alien species flying, it's conceivable that each species brings to the table at least three different models, providing a varying wealth of the above technologies, and all considered Legal tech. Legal tech, per the unfortunate demise of unlucky racers, was generally salvageable (to a lesser degree anyway) by the locals. If only for ornamental decoration, the inhabitants scavenged this substandard tech to adorn their vehicles, dwellings, etc. Of course some of it too, did manage to survive. Regards the illegal tech, you can infer flight plans to the planet surface for those flyers was mapped to be less harsh so that the outlaw tech survived more frequently (and was therefore more easily plundered by the locals). Of course when it got scavenged, no one complained since illegal tech "is not" being deposited on the planet surface. Those aliens unfortunate enough to accompany their crafts to the surface will have implants allowing them more fluid control of their vessels, and it could be harvested and utilized to control the salvaged tech. Since a host of aliens from different species have crash landed, they bring from their respective worlds: dna/parasites/germs/bacteria/disease/etc. The introduction of alien organisms could account for genetic drift within the local population. Different alien species also used their unique brand of technology (i.e., different methods of propulsion, etc.), some of which not so friendly to unprotected DNA, and that too caused genetic drift, especially when components of drive systems (for example) were salvaged and used to augment native based drive systems. Some pilots did survive and built a life for themselves on the surface. Those with a dna signature close enough to the locals managed to mate the locals. The Probes for example were close enough in dna sequencing to permit mating and that also helped in promoting genetic drift. [Answer] It is not an "endless war" from the POV of the combatants, but since we are in an Einsteinian universe, spaceflight is limited to STL. Getting from Earth to Alpha Centarui will take 4 years at *c*, but since you can never reach *c*, the actual time will be longer. In fact, given the immense amounts of energy needed to reach even substantial fractions of *c*, the time is *much* longer. And that is only between our Solar System and the closest star system..... Fleets are dispatched according to complicated algorithms since there is no possibility of communication in real time between the fleet and the "home" system. Ships moving at large fractions of *c* can travel the distance in relatively small amounts of subjective time in their frames, but thousands or even tens of thousands of years pass between the launch and arrival times. This has several interesting issues. 1. Ships leaving from different star systems will experience different amounts of subjective time. This also means that any new technology developed might arrive *before* the arrival of the enemy fleet, depending on the geometry of the star systems in relationship to the target. 2. Intelligence will also be disjointed. The news of encounters with the enemy, tactics, technological assessments and so on will also be separated by great gaps in time. If the enemy fleet launched from Alpha Centauri, for example, took 40 years to reach Earth and sent the results of the encounter back via laser beam, the earliest that Alpha Centauri would know would be 44 years later. More distant systems would have this effect exaggerated. 3. Returning crews would be radically displaced in time. They would be decades or centuries removed from their societies at the time of launch, and would have few or no social or personal connections to anyone from their home systems. (Imagine the Spanish Armada left port in the time of Queen Elizabeth I, but is only returning to Cadiz today). Some of these issues were explored in Joe Haldeman's novel "[Forever War](https://www.amazon.ca/Forever-War-Joe-Haldeman/dp/0312536631)", and any part of your story set in space will need to refer to these conditions. For the people on the ground, the fleets appear at irregular intervals and space combat takes place throughout the Solar System. The occasional "new star" appears and then fades in a matter of hours as ships are savaged with massive amounts of energy. Because of this, space combat is formalized to a certain extent by fighting well away from planets, since they are the ultimate objectives of the fleets. Unleashing a "Nova Bomb" or dropping a Relativistic Kinetic Kill Vehicle (RKKV) on a planet is rather counterproductive in terms of overall strategy. The gradual rain of metals and other parts of space battles is actually the Earth encountering the debris orbiting the sun (much like the various meteor showers are the Earth crossing the path of ancient comets). There won't be a huge amount of stuff, both because spacecraft encountering high energy weapons will likely be reduced to vapour and metal confetti, and the energy of impact will actually accelerate the debris beyond solar escape velocity: the space junk will leave the solar system forever. So the pieces which do reach the surface are exceptionally "lucky" in terms of the energies being delivered to them, and exceptionally tough in order to survive such treatment. So even if one side or the other has decided to end the conflict, their fleets dispatched hundreds or thousands of years ago are still on the move, with crews reacting to plans drafted millennia ago and orders they received centuries in the past. For the people on Earth, the war seems have got on for all of history and back into the time of legends, and is likely to continue for centuries to come. [Answer] ## Borderlands The solar system marks the border between territories of two (or more) rivaling space-faring civilizations. They don't even want to conquer any territory, but they feel the need to prove their technological and military superiority by regularly sending fighter drones to the planets along their borders. It's comparable to earth-based governments displaying their tanks and missiles in military parades with the tiny difference that these drones are displayed in action in a distant solar system no-one cares much about. It might well be that both civilizations have agreed upon a truce and just continue their quarrels because neither want to be the first to stop in fear of being perceived as weak. The drones are unmanned, autonomous and relatively cheap, so they're thrown at the opposing civilization without much thought. That's the reason why no-one on the planet ever sees an alien. But they might be able to see flashing lights surrounding other planets (or stars from their perspective) because the fights encompass the whole solar system, not just this one planet. ## Religion and tactics It could also be that one civilization considers this planet the sacred place of their origin. That's why they don't set foot onto the surface, it's too sacred to step on. The opposing civilization wants to conquer this place not for resources, but to lower the morale of their opponents. They send stealth attack squads deep into enemy territory just to keep them busy and divert their resources from the battlefront. [Answer] For reasons to fight, see the other answers. But the Solar System is big. We really shouldn't be seeing much without telescopes, and the odds of any wreckage from some random spot actually hitting the Earth is very very slim. For some reason, they take the battles to Earth orbit so that wreckage can fall down here. I would suggest that the reason is the Moon. The Moon has a nice lack of atmosphere and a reasonable gravity and is generally a perfect place for a military base. There might be other bases around the system but at least one is on the Moon. Earth itself is not so interesting. Too high gravity and all that horrible *air*. And where is a military base, there will be fighting. Attackers will be slingshotting around Earth to strafe the base at high speed. Being hit by the defenders while slingshotting and pieces will be raining down on our poor planet. And missiles missing will have a good chance of going the same way. [Answer] You try to see picture so big you cannot see any of it. Look at planet earth. In the last thousands of years there was no moment in its history that somewhere we hadn't had a war going on. For someone looking from a distance (like different solar system) that may appear as "eternal war on a planet". You think this war was fought my same multiple races for one sole reason. While in reality there might be multiple wars, fought by multiple races with each other in multiple combinations (just look at Europe in its last 500 years) for different reasons that YOU may narrow into one: * Some races just didn't want THIS planet to belong to THAT other race. * Someone's grandma was buried there. * It's where those religions have their sacred places. * Lord Emperor lost his magic key for his fiancé's chastity belt when he was passing over that planet and he REALLY needs to find it (but his competitor Emperor Lord try to get the key as well). * It's a well known planet to have fights because it's barren and no one is in violation of Space Code X5gHd-SD that forbids space battles around planets over class 2. * They just met there by accident and changing space parameters is really a drag. * The land on that planet looks like the face of that one other race guy who insulted our King so we need to destroy it (while they try to preserve for the opposite reason). [Answer] Let's say the planet is Earth. The "Aliens" all originated from a single space program that propagated. That program included the coordinates of their home planet on the colony ship. But Earth was, due to whatever reason, completely uninhabitable, and would take millenniums to be habitable, therefore it was hidden deep in the code and programmed to be revealed after that time period was passed. This message only served to record the colonists origin and not very detailed. Due to the time elapsed since they have left and their points of settlement, the different colonies that set out developed very differently, and have lost most of their history or that possibility of other colonies exit. A lot of them however retained the original programming for their colony ship mainframe, due to sentimental value. And this program started showing anomalies after the time had passed, attempting to broadcast, via rather ancient means the planet of origin. A lot of the future colonists managed to decipher this message, and even after more time, decided to return. Each of these civilizations, so different from one another, arrive to find another civilization surveying their home planet, and therefore thought of them as invaders. I am hand waving a lot on why they arrived around the same time or why they did not just decide to communicate, as those are very story based. Could be that space is a hostile place; all systems with habitable planets are valuable resources and are fought for violently, therefore it is natural to attack competitors in sight. Or even if they are the same species, they are too different to share the planet. Perhaps the first civilization to arrive was surveying the system before making contact, and the second arrived shortly after, before the first could settle; the others started joining in as they arrived, forming alliances or taking their own stand. Think World War, but in space. Either way the situation just escalated, with each civilization preventing the other from making a landing. Those that had remained behind on Earth, possibly surviving the inhospitable conditions, lost all progress. But humans love tales of hope and these survivors held on to the tale that the colonists will return some day to save them, and these tales soon grew to legends, all having the common theme of lights (ships) appearing in the sky. [Answer] # You Can't Go Home Again *Not a war, but a series of failed incursions, everyone after the same prize* Consider a distant-future Earth long after the diaspora, where the newly-risen far-flung colonies have rediscovered the ancestral home of all Terran descendants. How do they know that this is that the ancient home of all humanity ("Dirt" or "Earth" or whatever, a la Harry Harrison in the Stainless Steel Rat series)? Because it's protected by an AI-driven robotic defense fleet that makes this clear to all who approach: exo-humans are not welcome here. Only registered Terran citizens may land. (But of course, no such planet-side citizens still exist.) ## The Diaspora Perhaps at some point in the distant past, most Terra-bound humans were cast out to the stars as a population control measure to save the home planet for the lucky few, and the orbital automated defense systems were designed to enforce that decision. After many millennia, the civilizations of Terra fell into ruin, maybe having finally exhausted their resources and trashed their environment after all, still squandering what they were striving to protect through the overpopulation expulsion program. Access codes were lost, key personnel died, or the AI simply stopped listening to what appeared to be attempts from within to subvert its mission. For whatever reason, there's now a low(er)-tech human presence on the planet and a high-tech robotic presence in space, maintaining and upgrading itself, harvesting resources via asteroid mining operations, etc. - but staying off-planet because that was part of its original charge: that and to destroy all possible incursions from without. ## The TOOLS for the Job Such incursions finally come (or finally come again) - at first, in the form of robotic probes and then as scouts, both from some of the newly-risen-again, far-flung human worlds. As all such missions vanish, small exploratory strike forces arrive to investigate with force, discovering that the Terran Orbital Defense System (TODS?) or Terran Orbital Outsider Lockout System (TOOLS) or (insert other nifty acronym) has technological prowess well beyond the various human worlds' technological capabilities. Though most of those fleets are destroyed, too, inevitably someone escapes to report back, and new incursions are planned, new technologies developed to aid in the fight - but since information on the TODS / TOOLS / ? is so limited, all battles so far have been lost, with much salvage to be enjoyed by the robotic fleet, but with occasional incidental debris falling planet-side, too. ## Waves Against the Wall As word spreads, the human worlds, each with their own degree of cooperation or isolation from the others and thus their own unique designs and technologies (and, perhaps, mutations / engineered genetics / degree of alien-ness), continue variously to send exploratory fleets, then larger and still larger battle fleets, in an attempt to claim the planet and its presumable technological treasure trove. Occasionally, perhaps, they might arrive concurrently and end up battling each other, but (as interstellar travel takes so much time) most often the fleets arrive separately and simply run up against the TODS / TOOLS / ? resulting in more space junk donated to the planet and its unique scavengers. ## The Vault Is Empty... ? Ironically, never having been close enough to gather intel on the planet's surface, none of the exo-human civilizations yet realize that if they ever manage to breach the defense system, only a great big ball of Road Warrior wasteland awaits. But some of the more clever among its denizens may be the key to unlocking an as-yet unseen treasure from all this trash... [Answer] There's another civilization, much more powerful than any of the warring parties, that has announced an ultimatum: no one harms or sets foot on that planet, or **we** are going to go to war. (why, oh, why, would such an advanced race protect such an unimportant planet - wink wink nudge nudge *cough* it's because it's Earth and they're from there *cough*) They're advanced enough and surveying enough that a false flag operation would be too dangerous to try. There are complicated loopholes. The occasional accidental gear falling down is fine, but keep the mass lower than X, energy lower than Y, and don't go after it. Colonizing the Moon around it is allowed, but no damage beyond Z amount of energy, no messing with its orbit, and no mass addition or subtraction beyond W kilograms. All in the name of avoiding affecting the planet. Unintentionally, they made it very advantageous to have a base on that Moon. A logistics center that the enemy cannot just nuke. All sides are constantly trying to set up such bases, and constantly preventing the other sides from doing so, or destroying their bases - the hard way. No one can afford to just let their enemies have the advantage of a Moon base. The war rages on for a long time for reasons unrelated to this local anomaly. While the war lasts, all sides keep reinforcing their position in this system, as they cannot afford to leave it. [Answer] Flower Wars. The Aztec waged ceremonial war to please their gods and get worthy enemies to be sacrificed. If they fought the war to its grim end they would run out of worthy enemies, tributaries and, above all, worthy sacrifices to the gods. The starfaring civilizations are space Aztecs that wage war for religious reasons - capture warriors to sacrifice. They all descend from an ancient group of earth colonists that left in some sleeper ship and are now coming back in FTL ships. Or maybe it's STL ships but then they will probably be cyber Aztec space elves, that were once Man, to live the thousand years needed to travel across the stars. The captured warriors are taken to Mars and sacrificed in a blood altar there. The solar system is chosen because it's holy. They don't resettle earth because it is holy. They also, due to their religion, take care that no relativistic bullet, antimatter bomb or quark-gluon plasma accelerators hit the holy world. [Answer] Based on the Star Trek Voyager Episode [Blink of an Eye](https://en.wikipedia.org/wiki/Blink_of_an_Eye_(Star_Trek:_Voyager)), where the locals also began worshipping the sky-ship, there could be a time dilution field based on some highly localised tachyon flux (babble babble). Thus, the battle does not actually last ages, but the time on the planet goes much faster. Thus, every 1 minute of space battle an entire year passes on the planet. [Answer] Two nations/ space civilisations could battle for the resources in the Systems Asteroids. From time to time they battle, deploy miners, gather, and get beaten by the other nation and so on. That would make a lot of battles, lights, junk and the miners won't go down to the planet. [Answer] **War Games** Several allied spacefaring races, each descended from Humans, return once every few years to their shared world of origin for a friendly competition to test their newest military inventions against each other. [Answer] Since you want something like a Mad-Max/post-apocalyptic world, go with a post-apocalyptic universe. A highly advanced race/civilization created the technology for FTL travel and spread this throughout the universe as part of their vast "empire." This empire was overthrown/destroyed by their subject races (my preference, but some other SciFi trope of your choice would work as well), so it is no longer present in the universe (at least as it once was). The process to create the FTL "drives" (or some other component required for FTL travel) requires factories that are built in close orbit around stars with very specific compositions (size, age, elements present, etc). The actual means for building these factories and/or their operation (i.e. make them automated) have been lost when the advanced empire/race lost its place in the universe. As such, all the remaining races/factions using FTL drives vie for control over the factories to maintain their position in the universe. As the centuries have passed, fewer and fewer of these factories remain operational (malfunctions/wear and tear, damaged/destroyed by solar flares/conflict over control/collision with other objects, etc). This makes control of any of the remaining factories a highly desirable objective for any race and they change hands frequently (potentially multiple times per year). This meets the requirements of the original question and provides a framework for more detail in the following ways: * Control of at least one factory is key to a space faring civilization's survival. Without access to FTL drives, a civilization loses the ability to repair or build FTL ships. As a finite resource, this will cause repeated conflicts by multiple races/factions. * Races/factions may be able to claim the "prize" but ownership will be continuously challenged by other races/factions. Even if controlled only briefly (weeks or months) by a race/faction, they would have access to the FTL drives produced during that time. * Over the centuries, reduction in the number of factories increases the amount of conflict over the remaining factories. This creates a world where you can increase the amount (and types) of materials that make it to the surface over time. * While races/factions share a common FTL technology, all other components of their civilization/culture could be unique - weapon tech, defensive tech, aesthetic/design choices, entertainment, etc. * Equipment/tech could come from more than just "warships" as there would likely have to be a supply of resources going to each factory and the completed drives would need to be transported elsewhere to be used to repair or build FTL ships. This opens up raids on supply lines and piracy as sources of technology. * The nature/type of equipment/technology that makes it to the surface of the planet could change over the centuries as the races/factions struggling for control of the factory changes over time. * The planet could be Earth; one that was subjugated or nearly wiped out during the reign or fall of the advanced civilization. Races/factions descended in some way from the original inhabitants of Earth would likely form a number of the groups vying for control as they originated from the same galaxy/area of the universe. * No need to interact with the primitives. If the planet has no resources necessary for the operation of the factory, there is little reason to actually visit the planet. With control of the system changing so frequently, there is also little reason to invest in any sort of infrastructure on the planet. * There could even be some sort of "Geneva Convention" that all races/factions adhere to that provides "rules" for conflict in systems with factories to prevent further risk of loss due to conflict. These rules could provide the basis for any number of specifics of the races'/factions' interaction in the system that you desire. [Answer] When I hear "endless battle" I think of a runaway AI problem. So you build an AI, you cant program its moral code of conduct as thats far too prone to problems so you have it learn moral codes. You put it in a simulated world and test a trillion moral dilemma's, big and small on both large and small scales for years and years to make sure there is no edgecase that could give problems. You give the AI the task to terraform the Galaxy for any expanding lifeform while supporting any lifeforms it comes across or that develops before sentient species start inhabiting the planet. These species must first reach a certain technological threshold (or doomsday scenario) before the AI lets itself be known and lets other species mingle with them. Then you give it a bunch of self-replicating robots as hosts and send it to the stars. This code of conduct is basically the AI's main DNA, and since you dont want the AI to rewrite this code of conduct that you approve off on a whim you set it in stone as a set of rules it cannot change ever. Like DNA the data can slowly degrade, be misread or written down wrong on whatever is used to store it. There will be dozens if not hundreds of failsafes to ensure any errors are found and either rewritten properly or completely removed, IE destroyed. Given enough time (milennia) and enough replicating bots, there will be enough simultaneous errors that a cancer will develop, or in this case a large section of self-replicating bots will be written with a wrong code of conduct and assume its the right one, then try to rewrite this code on all bots that do not have their new code of conduct or destroy them. The actual difference in the code of conduct can be minuscule and irrelevant to the original owners, in fact all the species they are protecting will likely not even know it if they met bots from the "new" AI or not or landed on a planet terraformed by one or the other. When the new and old AI components meet, they will try to rewrite eachother and when that fails they'll try to destroy the others to prevent the "wrong" code of conduct to spread any further. Since they are simultaneously trying to murder the other but also fulfill their duties they'll be around planets with sentients a lot, as they dont trust the other AI to fulfill it according to their code of conduct. They'll actively try to protect the planet and destroy the opposition. This means stray hits with WMD like weapons are unlikely as it screws with their COC too much, and since the AI has to make sure none of the ships are carrying sentients of another race before they blow it up they will be fighting in much closer combat than you would expect to be better able to spot lifeforms. [Answer] The planet is actually stuck in a spatial anomaly. While the inhabitants of the planet actually see nothing wrong, with their sun rising and setting every morning, and the stars crossing the sky at night, in fact the entire planet is trapped in a spatial anomaly. This is perhaps caused by the crystalline core of the planet, which generates something similar to a magnetic field, but much more powerful and gravitometric in nature. Any ship that comes too close to the planet will find itself trapped in a buffer zone between 300 and 10,000 kilometers above the planet's surface. Attempts to come any closer will destroy the ship, while ships attempting to go further away encounter a gravitometric inversion in which the force of gravity increases exponentially. Were a ship to manage to get further than 20,000 kilometer from the surface this inversion would entirely be undetectable, while in the 10,000 to 20,000 kilometer range a kind of "sticky trap" exists where ships are pulled in and can only escape with quick thinking, enough fuel, and some luck. Likewise, between 100 and 300 kilometers the anomaly also tapers off, leaving those on the planet completely unaware. In the middle of the disturbance is actually a calm zone in which a ship might remain for an extended period with only minimal use of fuel for life support. Any ships unfortunate enough to become trapped in this anomaly quickly find themselves cut off from all radio contact from outside the field. They might perhaps signal optically, but this serves at best as a warning to keep other nearby ships away, as those ships who have attempted a rescue have wound up trapped themselves. Any ships exploring too close to this planet find themselves in a conundrum. Having managed to avoid destroying themselves try to land and retaining enough fuel during any escape attempts to stay around the planet for a while, conditions are soon found to be dire. A captain might try to team up with any other survivors in the anomaly, or might instead try to attack others and take their resources to prolong survival for a bit longer. Newly trapped ships might find themselves *fresh meat* and forced to fight for their survival or form alliances as quickly as possible. The planet is near enough to galactic traffic to occasionally get new ships trapped in its web, and these ships sometimes battle for weeks until the dominant ship or faction of ships is victorious and gains enough reserves to last until the next arrival. But being far enough from standard shipping lanes, the anomaly isn't well known to be avoided or officially investigated either - perhaps with only rumors which serve to attract adventuring types and keep the cycle alive. [Answer] If the planet is Earth far into the future, there is no need for conflict. The flashes and debris are simply satellites crashing into each other and deorbiting. [Answer] ### The Prime Directive [The Prime Directive](https://en.wikipedia.org/wiki/Prime_Directive),prohibiting its members from interfering with the internal and natural development of alien civilizations, is an important guiding principle for a major advanced civilization but mostly useless if they let *other* civilizations interfere. Turns out that this planet has *vast* natural basins of liquid H2O, largely unused by the native sentient race. The second most advanced civilization out there is very eager to get its hand on this resource, while the most advanced civilization is just as eager to protect it. Thus, you have an everlasting wave of attack ships trying to break through an everlasting defense formation, all while the strongest party makes sure that no contact is made with the planet below. [Answer] Does it have to be battles? The remnants of earth happens to sit beneath Trash Wormhole #3's exit node. Various intergalactic species use this wormhole to dump old and defunct ships as well as waste that is unsalvageable. Small trash burns up on re-entry but sometimes bigger pieces of trash land on this desert wasteland. Millions of years ago most of earth's inhabitants left on huge ships (think Wall-E) leaving behind only a few who have been forced to live on what is now a barren planet due to global warming/nuclear fallout. Far flung human species now use the solar system as a literal garbage dumping ground which would explain the random appearance of seemingly alien technology and why nobody would ever go there. [Answer] A fairly simple solution (ignoring complications of kessler syndrome) would be that your planet is off-limits to the galactic community. One of the races in eternal battle are essentially the guardians/galaxy police, ensuring that no contact is made. Much in the same way that there are international laws on earth now, regarding the contacting of uncontacted tribes. The opposing force, then, is like a galactic church sending missionaries to enlighten the locals. They are never very effective, so the guardians always "win" and beat them off. [Answer] **We come, because everyone else is already here.** Time has become meaningless, there is nothing left. Literally nothing - Every star in the entire universe has burnt out, exploded throwing it's own mass out into an infinite darkness. All the spacefaring races know the end is soon, but they also know that the only power left, is that which is held by those they may of once called friends, and now have become mortal enemies. In his final days of exploring, as the universe was literally dying around him and the various species in the universe were all fighting in their home galaxies, or in the places they considered the most strategic and valuable - which is amusing considering the only value now is energy, which is largely lost anyway he made a discovery which blew his mind. A single planet which some how had survived yet never been discovered, untouched by any hand of intelligence. It was pristine and it was unburnt by that which now pervaded all else - the thirst for energy. He made his choice there and then, jettisoning the energy capsule to land on the planet, meaning the planet would be protected, yet fought over until either there remained one winner and they could collect their winnings, or all would be gone and the universe could finally sleep. His ship came down, far enough away from the energy capsule to ensure that it survived even if he didn't and in his final moments he smiled. The energy capsule was more powerful than some of the largest stars, it'd leak heat and energy into this planet, keeping it living for thousands upon thousands of years if undisturbed and if the wars in the heavens did finally end that too he guessed, made it a fitting prize to whoever could land and take it. But how to make them come? His beacon would let them know, screaming out into the nothingness 'I was here'. --- Explanation: The universe is dead, all the stars are gone - the only source of power left is energy capsules, which are slowly running out. Those races which managed to escape to space all need energy to survive. Somehow, someone ended up finding a planet, after everything was dying that was undisturbed. They launch their energy capsule into the planet, ensuring it's short term survival, but also dooming it to become the largest target in the universe. A huge amount of power inside a planet, inhabited by those who have no clue what they have. All the races of the universe will flock to try and win the battle, to take this energy - mean while on the planet the inhabitants see, but don't understand hat is happening in the heavens above them. [Answer] Diametrically opposed philosophy. Classic sci-fi references here Borg, Dalek, cybermen are all races that fight solely because they feel every other race in inferior. Many other examples exist. Your race has to fight or one of these races will wipe them out, convert them, or enslave them. The only question would be why they come to an exact area. Resources would be one of the top reasons. Also strategic advantage, so some kind. The aliens hide except every ## years or etc they make a pilgrimage to this area. It is/was there home world, some people will always try to go back. [Answer] # The Farce There is no war between two factions, there is only one faction of aliens, at war with itself. Its computer systems are so corrupted, its culture so paranoid, that communication in the war zone is abandoned, and the opposition is to be engaged at all costs. And boy, how powerful that opposition must be, how entrenched, as this black hole of a conflict swallows all the have to give. Honor demands, that no prisoner ever falls into enemy hands, so suicide is encouraged or even enforced. Pockets of gone mad predecessors, have built the equivalent of scrap-yard foxholes everywhere in the system, sniping at newcomers and old inhabitants alike if there is a chance to get away with it. Maybe even add some sort of obstacle to explain the lack of circumventing tactics. Subspace was bombed to hell in a previous war. Or add value to the planet, hidden beneath the surface are the ancient archives - its holy ground, where you go in times of crisis, to retrieve knowledge of the ancients. [Answer] ## The Moon is an Advanced Outpost It doesn't matter if the moon is an advantageous strategic position or just the home of some key research facility - the point is that it should be relevant. So relevant that other alien races (or other versions of humanity, to meet your criteria) keep continuously sending troops to try to reach whatever lies in the surface of the satellite. You could even use some of the other answers in this very question as seeds to better improve this explanation. For example, Syndic's FTL highway concept is pretty awesome. Why not make it so that the moon is also a pit stop for travelling ships? It would also be an explanation as to why this base can keep receiving enough reinforcements to keep fighting for a very long time. [Answer] Building upon optimisticOrca's answer around multiple colony fleets coming back to the earth thousands of years later. Instead of saying that all aliens(ancient humans) arrived at the same time it could be that there is a large defence satellite array around the earth that has been defending it waiting for the colonists to return however as so much time has passed the array has malfunctioned/ does not recognise them as human and attacks the fleet. As more fleets arrive to a hostile environment they could mistake the defence array as an attack from the other fleets. Over time the defence array could be destroyed but the fleets would continue to attack to defend their so called "holy land" from the alien invaders/ occupiers. As a way to keep any of the races from gaining an upperhand you could always say the defence array was the pinnacle of human engineering designed to repel any attack and leave it in place so anyone who got near the planet was destroyed. This would stop anyone from claiming the planet as regardless of the size of the fleet it would not be able to get to the surface. [Answer] ## Toxic atmosphere Though this planet has organic life it has evolved a little bit differently than in other places. At some point bacteria on this planet started producing a toxic gas that through the eons has slowly been building up in the atmosphere and eventually reached a stable level millions of years ago. Life on the planet has evolved to tolerate this toxic gas as the concentration in the atmosphere was slowly growing. But so far no multi-cellular organism from any other place has been found to survive that gas. It's so toxic that even with the best available protection anybody who attempts a landing would die before reaching the surface. This is something that may have been learned the hard way. ## Exploration and tourism So who would have an interest in this toxic environment? Civilizations at this level of development may be rare so there is a scientific interest in studying the civilization from orbit. Additionally this is a popular destination for wealthy tourists who want to see the most unusual sights on their vacation. ## Space junk Over time a lot of space junk has started orbiting this planet. Some of the junk is deliberately deorbited and is responsible for some of the flashes in the sky as larger parts burn up on entry but some parts survive the landing due to being smaller, more robust, and or better protected. Accidental collisions between junk and orbiters as well as between orbiters and other orbiters are responsible for other flashes in the sky and more space junk of which some may fall to the ground. ## Piracy There is a number of pirates orbiting this planet as well. Likely these have started out as low salaried employees of the various missions to the planet. At some point they may have staged a mutiny and taken control over one or more orbiters. Unlike official missions the pirates don't receive supplies from home, so they have to steal everything they need. Little did this piracy do to stop tourism to this planet. The tourists came to see the exotic and dangerous planet and space pirates just added to that. Travelers to this planet believes that orbital mechanics is predictable enough that they can spot and evade the pirates. Though over time pirates have found that abducting wealthy tourists for ransom is a profitable business. ## Taxation Various governments have decided to tax travel to this planet. Officially it's to protect the civilization on the planet from evasive tourists, unofficially it's just a source of income. This has lead to wars over who is allowed to collect taxes. Though these wars are of little significance to tourists who are wealthy enough to pay taxes to every government that consider themselves entitled. ## Could this be Earth? I haven't stated which toxic gas is in the atmosphere on the planet. If it was Earth the prime candidate is oxygen. Life in other places may have evolved in a way that did not involve an oxygen rich atmosphere and simply cannot tolerate it. And humans travelling in space may have developed life support systems that supply just the right amount of oxygen directly into the blood stream. Over time evolution has gotten rid of superfluous organs such as lungs, and space craft have replaced oxygen with pure nitrogen if not a complete vacuum. As these human descendants have not been exposed to oxygen for many generations their skin has evolved to a form that is more robust against radiation but vulnerable to oxygen. Meanwhile civilization on Earth may have experienced major setbacks due to climate change. And survivors many generations later only know fractions of what happened in the past from word of mouth. [Answer] Once a war has gone on long enough, it tends to continue just because the other guys have killed / are killing our guys (see most of the world). Provided neither side has a serious chance or the political will for wiping out the other side (easy to posit due to effective planetary defences), the battle continues, away from both sides' home territory. So it will be in 'no-man's land'. Which means in space the battle tends to continue where you find the other guy, which is where he's looking for you, which is where we've always fought, which happens to be over this random planet. For bonus fun, the primitive civilisation is actually descendants of early escape pods which crash-landed on the planet generations ago. ]

[Question] [ Since I haven't found anything like this yet. I was reading a novel and it talked about how some people created a 'Artificial Virtual Reality World' where the denizens were Human Artificial intelligence. Which to put simply, they reproduced earth in virtual reality with all the humans who can think for their own and have their own thoughts. Now the only way those Artificial Humans found out they were living in Virtual reality was due to Real humans from Real life entering that world and actually telling them that they were living in a Virtual reality. Now how would someone find out that they are living in a virtual reality if every condition, sense and Fauna on earth and the galaxy and the universe itself were reproduced perfectly? Which means there is literally no difference living in the real world and virtual reality. Would he/she be able to find out that they are in virtual reality? The kind of Virtual reality I'm talking about is like the VR in [this](https://en.wikipedia.org/wiki/Sword_Art_Online), where they wear a helmet and 'dive' into the VR. [Answer] So Descartes's Meditations on First Philosophy speaks on this. How would you determine that a perfect deception is a perfect deception? If all of your senses are lies and constructs, perfectly flawless, how do you figure out that you are in this deception? Simply by the very definition, the deception is perfect; so no flaw can be found, and a flaw is what you're looking for. More to the point if this perfect deception is all you ever knew, everything you're basing your reasoning on to find a deception was learned as part of a deception, so *it* can't be trusted; if you were taught that '2 does not have consistent value', your conclusion would be that '2 + 2' does not have a consistent value. In other words your attempt to find flaws will be hopeless if based upon flawed assumptions. Take the computer simulation. If the simulation depicted computers *fundamentally* working different than they do in the real, non-simulated world, what hope would you have of figuring out that you were in a computer simulation? To get a better idea of this let's take a different example. Let's say that you, as in the one reading this text right now, are in a perfect deception, and have been all your life. The deception's mechanic? Specifically a magic spell. "Well that's a silly notion, magic doesn't exist!" you think. Doesn't it? What makes you think that? Are you drawing from your past experiences? If you *are* in a perfect deception, as we are assuming, could the deception not have lead you to believe that *of course* magic isn't real? In fact, wouldn't that be an ideal mental trap, to make you refute the very idea of what has you imprisoned? Kind of a scary concept. And there's no way you can--with every scientific tool at your disposal--say that you aren't under the influence of a magic spell or a computer simulation. There's no way you can say that your whole life *hasn't* been a perfect deception. But we have to live our lives assuming it not to be the case, and treat the possibility that it is the case like a simple thought experiment. I mean we all know that magic doesn't exist, nor does the Matrix. Because that'd be silly, right? ...Right? [Answer] # We cannot know this What you have there is a modern version of Plato's [Allegory of the Cave](https://en.wikipedia.org/wiki/Allegory_of_the_Cave). So your question has had its answer for a very long time: unless the simulation is in any way flawed and/or giving out hints of its existence, we cannot figure out that we are in a simulated reality. [Answer] This is an actual scientific debate. It is called [Simulation Hypothesis](https://en.wikipedia.org/wiki/Simulation_hypothesis). Some physicists suggests us not living in a simulation is unlikely. Obviously, most plausible (in my opinion) of these theories suggests that the simulation runs at quantum level. [Here](http://www.simulation-argument.com/) is a website with links to scientific papers about the topic. [Answer] If we define perfect simulation as one that appears to operate with the same rules as our universe rather than one that replicates every particle then we can have a few things that we can point to... 1. Mass causing time to slow may in fact be an indicator that we live in a simulation. Mass = Data. Time = Processing. The more data in an area the more time it takes to process that data. The data is more causally linked to each other and thus increases the amount of operations that are needed in a particular spot, ultimately slowing the simulation in that area while the rest of the simulation continues on at its normal speed. 2. A digital universe is an indicator of a simulated universe as well. If we can only resolve down to a given limit, such as planck scale, and can go no further because it is unresolvable, that there is no meaningful way to divide the scale further, then that means we are likely looking at a universe that is simulated, because a simulated universe requires that it be digital. 3. Likewise, things that happen in Quantum Mechanics would indicate a simulated universe. Those things being things like, I think it's called Quantum Tunneling. Basically any time you have an event where it makes no sense logically that the event happened. For example, it makes no sense that a particle can pass through a solid wall, or have its vector changed by nothing, but it does happen and the math completely supports it. If the universe is a simulation these things become reasonable by fact that what's happening is not that an object is doing things that make no sense, but rather an object is simply following an equation that says this should be like this without any regard to past or future, and in some cases, present, conditions. I'm sure I could think of more, but one solid thing that seems to land us not in a simulated universe is Quantum Computing which seems to indicate infinite resources which I don't think could be used in a simulation of an universe because of the type of programming required, but I'm not sure. Of course we could also talk about what IS a "simulated" universe when more than likely an infinitely larger amount of universes are simulated than those that are not. [Answer] There is only one test that I can imagine working, and it is very dangerous and would probably not work... **Piss Off The VR's Creator!** Do something that will bring a premature end to the best parts of the simulation; making a waste of the billions of hours of programming and testing time which the creator has invested in this VR. Launch all the nukes! If the bombs actually do fall and explode, then we learn nothing. But if the VR program doesn't allow its own destruction... then we would know that we are created. ...at least until the creator edits our code and makes us forget about it. [Answer] Statistically speaking, it seems improbable that we are not. Consider that at some point there will be one reality; and N simulations, where N is likely to be large. Consider that in each simulated reality, if reality is correctly simulated, there will be people who want to create simulations. So there will be, in a perfect simulation, N^2 simulations. And each of those will contain simulations, all the way down to the limit of the outermost resolution. So N^M where M is the limit of the number of levels before the resolution is too low for sum-simulations to be viable. So our odds of being in the original simulation are 1 to N^M. Logic suggests that N^M will be really, really big, so our chances of being in the original are approximately zero. Question is: what difference should this make to how you live your life? I can see no apparent reason for it to make any difference whatever, though it does suggest that there may be bugs that could be internally exploited. Biggest argument against all this is the absence of apparent bugs: a system so complex should have a LOT more bugs. Possibly they are shown by some stuff in <https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_physics> and arguably everything we dismiss as superstitious nonsense, any of which could be true in a simulation. --- Edit: another counterargument is that this math assumes that there is only one "real" universe. Consider the probability of each universe just naturally spawning another real universe is high (imagine every black hole generates a universe, or every particle/antiparticle collision generates one elsewhere, or whatever). Consider also that the probability of each universe generating an intelligence that wants to simulate it may be < 1 (reducing M) and the number of recursive simulations that you can get to and still have enough "resolution" to simulate a worthwhile universe may be quite low (so small N), and that changes the "1 : M^N" probability to "infinity : infinity \* M^N", which is a lot less definitive, especially if M turns out to be less than 1 across many universes. [Answer] There are 3 kinds of VR I could think of: ### Matrix VR Your body is held inside some tank, and all nerve endings that leave your brain are wired to some control device. I.e., you have a physical body, but all input/output is overriden. Everything entering/leaving your brain is simulated, no part of the real world is allowed through. It could be raining Donuts for what it's worth. They only control your sensory input though, not your thoughts. Exactly like in the Matrix movie. ### "Real virtual" VR You have no physical body, but exist purely in the form of information inside some computer. Similar to our "AI" experiments we do since the 70's, just advanced enough that your simulation can be called "intelligent" or even "self aware" (by whatever metric). Nothing of the real world can pass through except if your creators actively decide to do so (like in the movie Ex Macchina, where the A.I. has eyes/cameras etc. and is specifically built to cooperate with the real world). So as we are talking about a virtual reality here, they would not do that, but simulate the surrounding world as well; in that movie the A.I. really is on the *opposite* spectrum (completely aware that it is virtual, just trying to blend in as much as possible). This is conceptionally existing today, for example World of Warcraft simulates a world and beings (NPCs, monsters) inside that world. Scale that up a few million times until those NPCs/monsters can develop self consciousness, and you're there. ### Oculus Rift VR This seems to be what you are alluding to by your reference to that Manga. You are just a normal person; a fixed VR device is enclosing your head. In the far spectrum, it not only does eyes and ears, but also taste, smell, feel. Not only the head, but all other body parts as well. Your VR suit is so perfectly adjusted that you would never get the idea that it is there. ### Can you find out? * In the Matrix: depends on the software of your captors. If they manage to not introduce any kinds of artefacts which are inconsistent with the physics of their virtual universe, then you're pretty much out of luck. I.e., no "Deja Vu", no Agent Smith, no remnants of the old human race who actively unplug you. * "Real virtual": you have no way of finding out, ever. Your every thought process, every blip in your brain is simulated. Creators that can do that are certainly able to squelch even the tiniest pre-thought of any thought about being in a VR. Heck, they could make you believe that you are in a Matrix VR (including "waking up" from it) while you're still firmly in their VR (of course - where else would you, as the state of a software program, be). * Oculus Rift: depends on how good the device is. Can it simulate stuff entering your body? It's not too far fetched; as it gives you "real" tactile feedback for virtual food, you can feel like you are stuffing things in your mouth (with some virtual mouth implant which stimulates your nerve endings there etc.). Can it reconcile your internal bodily processes with the VR (i.e., having to empty your bowels etc.). It's really the same as the Matrix, only keeping your bodily senses up instead of "plugging you in", but probably much much harder to implement right. It totally breaks down if you need to simulate body damage (getting a limb torn off...). [Answer] While I have to agree with the other answers in saying that, theoretically, "we cannot know", I still think it's a tautology to say that "there's no way of knowing if the simulation doesn't let us know." The question is rather if the simulation is actually "perfect", or if it fails to foresee some clever/random move of a subject and thus makes some glitch visible. Think about the dejà vu scene in The Matrix. That is the kind of small glitch that does not fit the closed model simulated everywhere else in the VR and can make people try to investigate and exploit. In our world, think about quantum mechanics for instance. Those are so much not like Old Newton's physics which we're so much used to that you may start to wonder if we're just getting a view behind the curtain, glimpsing on the mystical machinery that actually drives our perceived, superficial reality. Now, what if some entity set up that quantum machinery to 'fake' a reality for simple beings. What if it did set it up aeons ago? What if it did not foresee that some day, aeons later, subjects in the simulation would actually gain the insight we have today? - Who would have thought that was possible even a hundred years ago? [Answer] To the virtual human the virtual reality - whether perfect or not - is an actual reality as outside it the virtual human does not exist. [Answer] If we were in such a simulation, would that not also explain god? Think about it. The whole idea of it. A 'being' of all-powerful...ness. He created everything, the planets, the sun, everything. who's to say that the 'big bang' isn't actually the fist launch of the program, the program that is procedurally generated. Jesus, the 'special' person, was some kind of 'real human' revered as special. the last few thousand years of our life have been a big buildup to the 'apocalypse' event. It's not much, but hey... it'd be pretty cool, no? Though in truth, if the world is perfect, with no way for us to tell that we are simply AI, the only way we could ever figure it out is with third party intervention. that being a 'real human' Otherwise, the answer is, no. there is no way to tell. [Answer] We can build simple simulated universes. None powerful enough to include an intelligence, but we can build simple ones. In those simple universes, we can build simulations of *other* simple universes. For a concrete example, we have built computers, in in those computers we have built minecraft, and inside minecraft we have built a computer capable of running programs. Now, in our universe, complexity (information processing) has a cost. As does it in universes we create. It seems reasonable that we could come up with theoretical limits on the ratio between the complexity of the simulating universe and the simulated one. We can then determine if our universe is complex enough to host a sufficiently complex universe that could itself host a simulated universe, both of which contain intelligences. I will call this "not at the end of the chain". If we are "at the end of the chain", and our universe is insufficiently "rich" to simulate a universe containing intelligence that itself could then host a universe containing intelligence, that is evidence *we are not simulated*. If we are not "at the end of the chain", then that is evidence *we are simulated*. This is because the very existence of that chain implies where we are on that chain is a matter of "luck" -- we could very well be on rungs even lower. However, the intelligence *at the very bottom of the chain*, which doesn't have further links under it, is an unlikely intelligence to be *in the event there is such a chain*. It is less plausible that we are in that special location, than if we are just another link, basically. On the other hand, I could see the argument that when simulating a universe containing intelligence, the interesting part is that universe not the universes it simulates. So making universes that are just barely able to support intelligence in your simulation might be optimal from a simulators perspective. The ratio still seems interesting towards this question. If simulated universes can be almost as rich as the one simulating them (ie, the overhead of simulation is *cheap*), it pushes forward a seeming certainty that we are a simulated universe. If the overhead is large, that leaves a huge conceptual space where an intelligence could exist, but no simulation could. [Answer] Yes you could tell if you're in a simulated world assuming you had the computational power to do so. I'll explain.. First let's start by saying it is almost certain that we live in a simulated virtual reality. Statistically speaking the odds of us living in `Prime Reality` is zero. The reason we can safely conclude this is by looking at our own reality and answering one question, given the current progress of technological advancement do you believe that someday we will have the computational power to simulate reality? If the answer if yes then you've accepted that you're a simulation! How? Because if we accept that we will someday simulate reality we also accept that technology will continue to advance past that point. While at first it might take a super computer in a university to handle that level of computation we know that it is just a matter of time until those same expensive computations become cheep enough that your home gaming console can handle them, and then a few years later your phones will handle those same computations. (Don't forget your cell phone now has more computational power then NASA used to send a man to the moon!). So therefor it's just a matter of time before people are simulating realities on their cell phones as a game while their pooping, and if just a few million people play the game that means they just created a few million simulated realities, and each of those realities has the potential to simulate it's own realities and in turn each of those simulated realities can simulate millions of more, and so on and so forth. As you hopefully noticed this is an exponential curve, where the more time that passes the more simulated universes that are created until the number borders on infinite. This all means that the statistical odds of you being in `Prime Reality` are 1 in infinity, or zero (Sorry!). Now to your question, we could tell that we're in a simulated universe by exploiting the nature of computers and the fact that they have limited computational memory. So in theory if a simulated universe were to create enough of it's own simulations then eventually it would overfill the memory on the system running the original simulation causing it to either crash or start dumping memory(deleting things). Although I don't know if destroying reality by crashing the simulation we exist in would really be worth it, but hey at least you'd know! [Answer] **pixelation** basically, any simulation has a max resolution. at some point, you stop drawing discrete pixels, and just calculate the average effect of everything below that resolution as a continuous field of forces and probabilities. for example, if you wanted to simulate the solar system without calculating the position and velocity of every electron, then you would simply use an equation to compute the average position and velocity the planets and other large bodies. the pixelation limit of that simulation would be at the planet level and you couldn't break apart a planet to look at how it's internal components interact. if you want to "zoom in" on part of the earth and see animals running around, you need to increase your computing power substantially. the pixel limit of our universe appears to be sub-atomic particles (e.g. electrons), indicating that we live in a simulation that pixelates at around the size of an electron. you simply can not assign a location and velocity to an electron in any meaningful way because it is smaller than a "pixel" in the simulator that runs our universe. [Answer] As an aside, here's a scary thought: **Who says the simulation has to be perfect?** The argument is, you would be able to tell you are in a simulation if you spotted the 'glitches'. But that presupposes that you already know what the REAL 'reality' is like, for comparison purposes! Anyone who *actually originates in a simulation* would of necessity treat everything observed - 'glitches' and all - as natural phenomena, and if repeatable would build those phenomena into their 'laws of physics' *[and if not repeatable, either ignore them or end up being thought nuts :-) ]*. [Answer] I cannot expose a lot of examples now and here but just one. A clue we are living in a virtual reality is the limited speed of light. The speed of light limits how fast we can transfer information, and it is limited. If you deal with computers and electronics you know a simulation cannot ever be as fast as the simulator it runs in. Limiting the speed of electromagnetic radiation (light) in the simulation could be necessary to prevent the simulation to crash/blue-screen-of-death/colide-with-itself/hang-up and so on. If some day it is confirmed remember you read it here first :). [Answer] If it's a truly perfect simulation, then it's impossible to know for sure. You can have suspicions and even evidence, that reality is a simulation, but that doesn't make it proof. For example, as others have pointed out in this thread, reality has a maximum resolution: the planck length. Quantum tunneling seems to show that reality is "Error prone." Space is mostly empty, meaning it'd be easy to compress to save storage space. The laws of physics are easily expressed using mathematics. You could keep listing reasons like this for quite some time. But does all of that mean 'reality' is a simulation? No, it doesn't. It might be, but it might also be that Reality is just weird. Quantum mechanics is bizarre and counter-intuitive, but our brains evolved to throw stone spears and avoid being eaten by hungry predators, and not to comprehend the fundamental structure of the universe. We're just not fit to decide one way or the other. Maybe that's why the idea of a simulated reality is so fascinating. To paraphrase one of my professors, it's the questions you can't answer that are the most interesting. [Answer] > > Now how would someone find out that they are living in a virtual > reality if every condition, sense and Fauna on earth and the galaxy > and the universe itself were reproduced perfectly? > > > The kind of Virtual reality I'm talking about is like the VR in this, > where they wear a helmet and 'dive' into the VR. > > > To **find out** means that one can tell the difference between reality and virtuality. **Perfect** VR means that there is no such difference. So, you have answered your own question: **one couldn't**. On the other hand, the VR would probably **not** be perfect due to the programmers' universal tendence to cut corners and optimize performances. So, for example, some details might have *perfect internal consistency* but have no *temporal consistency*. Think of a granite slab with all those white and black flecks, or the surface of a sheet of rough paper seen through a magnifying glass: when it is "not in view", keeping in memory its exact texture would be an awful waste of resources. So chances are that such a VR would be reasonably implemented by storing a small piece of information ("This is a sheet of paper of roughness 15"). Observe such a detail-rich object and memorize some details. Observe it at a later time. The VR you describe has no way of inspecting the simulant's neural state, so it cannot access or modify his memories nor even know what he noticed. It **might** have an "anti-tamper" mode that marks anything observed too keenly or too long for exact memory storage to foil this kind of scheme, which brings us to distinguish between "passive" VRs (they're just very good at simulating reality) and "active" VRs (they detect and thwart attempts to uncover their virtuality). But otherwise, chances are that two observations of the same high-entropy object would result in two different images being generated and supplied to the user, making him aware of what is happening. Another possibility ("Realtime Interrupt" by James P. Hogan, and a subplot in Peter F. Hamilton's "Fallen Dragon") is that the VR is unable to completely simulate some sensorial input such as smell, or taste. Much would also depend on when the VR did start (from birth? From some moment?) and what information is available to the VR's designers. For example I could accidentally splash my hand with cheap red wine. The VR would show me my own skin drenched in reddish liquid, each droplet perfectly simulated. Little would it know that I would *also* be expecting to see welts appear almost immediately in response to an allergic reaction. [Answer] If it's anything like our 'reality' why assume it's perfect. Ours 'appears' to have various issues: things that don't quite make sense, or lead to the right answers when we follow the mathematics, physics that requires kludges to work... Maybe we are in a simulation, and it isn't perfect. But how would we know? We just assume our modelling is incorrect - but maybe it is correct, it's just that the reality is flawed. [Answer] In order to create a virtual world identical to the real world, the real world has to donate enough energy to the copying process, the virtual world, and then to destruction of evidence of the process in both. This evidence is what virtual conspiracy theorists will be looking for. The original world will be completely changed by this, however. If the virtual world is a simulation and not a copy of the real world, then understanding and debugging requirements would make it inherently less complex than the real world. [Answer] **DATUM SCIENCE: THE MISSING SCIENCE** We are living in a virtual world that is of course more complex than those we can create as of now. Our virtual world contains datum. And a datum is framed around POINTS: Position, Object, Interaction, Noise, Time, within object Space. Using this framework, we can capture a single datum or object or spec of things (depends on how you want to use the phrase) Using the POINT framework, we may also create our own virtual reality. Objects are always interacting with one another through distance. The effect of the interaction depends on the distance. However, objects are bound to connect with one anther no matter the distance unless they find bound with a closer object. Then it creates form objects. You can even see the POINTS framework on Macro formed objects such as human beings and planets. Think about it. Everything is formed within Position, Object, Interaction, Noise, Time, and Space as an object. This is actually going to be my doctoral thesis. Read about it in a few years. [Answer] Boo, you can totally tell. It's simple. Others argue that you need all these simulations and fancy math equations and whatnot, but do you really? If you all had computers like you say (and like we [humans as a group] do), then you'd easily be able to tell if it was fake or real. We all know that the people on the Internet aren't real - not real in the sense that you can't touch them. How do we know this? Well, first of all, most people probably never tried to hug or kiss a YouTuber out of the *deception* that they were real. They just believed it.\* But believing is seeing, right? And so is the reverse (of the previous statement). Whether one or the other is better is yet to be decided. \*They believed they weren't, as most people don't. Unless you had some sort of mental illness or impairment that made you believe so. What's wrong here is you're presupposing that we are in a virtual reality. What if we're not? You've got to start from there. You've got to say, "This is real, and this is real, and this is how I know they are." If you can't back up your statement, then you know it's false; but if you have a burden of proof of some kind, then by default of logic, it is real and indisputably so. I think the question you're missing is: What *is* real? (As in, what defines it?) And what isn't? ]

[Question] [ I'm creating a full-fledged galactic republic, in a galaxy not so very different from our own. It's designed to encompass the majority of the stellar systems in the galaxy, including some of the globular clusters orbiting outside the galactic plane. I'm aware that [a galactic government of any sort](https://worldbuilding.stackexchange.com/q/23513/627) will face logistical challenges, but I'd like to have a capital planet nonetheless, à la the Coruscant of *Star Wars* (though preferably not a city planet). I have some ideas for the planet itself, but I'm still trying to figure out *where* to put it. A central location makes it easier to get to all parts of the republic in reasonable times, with faster-than-light travel, but it risks creating a prosperous bubble that could alienate other parts of the republic. I could put it somewhere on the outer rim of the galaxy, but that makes it inaccessible and gives it an even more isolationist feeling. Setting the capital somewhere in between is yet another option. I do have some criteria I'd like to evaluate answers on: * The ability to get to most parts of the galaxy in a reasonably short time (assume that travel may be faster than light but still finite in speed). * The amount and type of resources available (e.g. hydrogen gas available to be harvested for fuel; element distribution was discussed [here](https://worldbuilding.stackexchange.com/q/40474/627)). The capital should be in a place that's fairly prosperous. * The stability and safety of a planet in such a region. Places prone to stellar collisions are not good choices! Additionally, placing the planet near the supermassive black hole is likely not a good idea. Bearing these criteria in mind, where should I put the galaxy's capital? Near the center, the outer rim, in between, the halo, a globular cluster, or somewhere completely different? In a stellar cluster, molecular cloud, or in a lone system? [Answer] It is important to realize that there is a historic context to a capital. This means a lot of things, and let's look at some Earth capitals to compare: Washington D.C. makes no sense as the capital of a large, wide-spread nation like the United States. It is far on the East Coast, is part of a district that isn't in any particular state. Historically, however, it was built in a location to be center to the 13 colonies, and its existence outside of any particular state was to represent its independence from those states. Originally, the site of Washington D.C. was a swamp, and it was a city built to lead. Bratislava in Slovakia is basically on the border between Slovakia, Austria, and Hungary. It is a capital largely because it was historically a place of power for the Austrian-Hungarian monarchies, and served as the capital of Hungary when Budapest was occupied by the Ottoman Empire, and during that city's reconstruction. Interestingly enough, Bratislava is pretty close to the geographic center of Europe. The final one I will point out is Brussels being the headquarters of the EU. This one has its roots in politics. The 1951 Treaty of Paris attempted to unify the coal and steel production of Europe into a joint venture, but nobody could agree where to host the meetings of this venture. Later the 1957 Treaty of Rome did a similar thing for Atomic energy, again with nobody agreeing where to permanently meet. An agreement was made that each signatory would host the meetings in turn, starting with Belgium. Because no further agreements were made with the hosting of EU instituitions, Brussels became the De Facto headquarters of the EU. How does this help your setting? Well, to make a capital feel like it fits and isn't contrived, all of these forces should be in play. I think the worst place for the capital should be the center of the governed areas. Perhaps territories enter or leave the Galactic Union (GU), or maybe the major shipping lanes don't go through the middle for some reason. Maybe the capital has been on Praxalaxis V since the beginning of the Galactic Federation (which eventually became the Galactic Union through the Treaty of The Boreal Nebula in 4502 and added the territories of the Union of Sovereign Stars). Heck, make the location of the capital a background story in your setting. Have protesters from the upper reaches of the GU want the capital moved, as Praxalaxis V is far to the bottom of the GU, and this benefits certain planets due to lucrative trading. Figure out the history of your galactic government before trying to determine where the capital fits. There are probably a few dozen cool things that could have influenced it. [Answer] Location of the capital will highly depend on the characteristics of light speed travel. First, here is a map of a galaxy that might look a lot like ours: [](https://i.stack.imgur.com/psQj3.png) Let's look at some possibilities. # Travel is along pre-determined 'wormhole corridors' Suppose, as many space-expansion games do, that travel is restricted to certain 'corridors' that are defined by some as-yet-unknown property of space-time. In that case, wherever there is a convenient and centrally located junction of 'space roads,' there would be a good place to build a capital. # Travel is restricted to certain-distance jumps If travel is restricted to jumps of a certain distance (some number of light years), then crossing the 'empty' space between arms would be dangerous. Therefore, it would be much better to travel up and down the arms, and then cross in relatively heavily traveled corridors. Different maps label the arms differently, but the Orion spur (which we are in conveniently) crosses kind of kitty-corner between the Crus-Scutum (or Scutum-Centaurus), Sagittarius (or Carina-Sagittarius), and Perseus arms. Not shown on my attached map is the 'long bar', a barred arm that reaches from the 3 kiloparsec arms around the galactic core out connect with Norma, Scutum, Sagittarius, and Orion Spur. Somewhere in the Orion Spur to Long Bar would be the best place for a capital in this scenario. Alternately there may be a dense spur arm that corresponds to the Orion arm on the other side of the galactic core that we can't see (since its behind the core). That is represented by the gray region on the attached map. # All space is passable If all regions of space are passable, and there is no penalty to crossing empty space, then the location of the capital would likely correspond with the highest density of habitable star systems, which should correspond with the highest availability of resources. This would be the regions just outside the 3 kiloparsec arms on either end of the ovoid galactic center, where the various arms merge into the 3 kiloparsec arms. The habitable planets would likely be in a relatively flat plane corresponding with the [thin disk](https://en.wikipedia.org/wiki/Thin_disk) of younger, more metal rich stars. # The inner regions of the galaxy are uninhabitable due to X Many sci-fi type stories suggest that the galactic center is hostile to life, due to black holes, radiation, or something. It could be that the presence of (many?) black holes makes navigation at FTL speeds through the core impossible. Alternately, it could be that high radiation levels prevents passengers from going through, or colonies from being established. In that case, transfer between arms at the 3 kiloparsec arms or at the bars might not be easy at all, and a galactic civilization would be best developed extending along a single arm. Perseus, Sagittarius, and Scutum are the three largest arms, with Orion spur being small, and Norma not being as dense. So the capital would develop centrally on one of the three large arms. # Who rules the galaxy? Whatever species ends up being dominant in the galaxy will likely have the most say in where the capital is. And if that species is sentimental about its homeworld, then that homeworld is likely to be default capital, no matter if its location is optimal or not. Good thing Earth is fairly optimal in 2 of the three scenarios above! [Answer] # Elect a Capital Hold elections to host the galactic capital and change it every few years (like the Olympics). Obviously, only systems that can afford to host the capital should be electable. This should also provide some plot details for you in terms of electioneering/fraud/violence/whatever. Candidates for Galactic Capitals should: * Demonstrably afford to host the duties of a capital planet * Be able to comfortably host representatives of all attending galactic races * Guarantee the safety of all participating representatives, regardless of any inter-race difficulties (neutrality is enforced) * Guarantee safe travel with the entire solar system of the current galactic capital It goes without saying that successful candidate systems will increase their chances of future elections. [Answer] Make the capital mobile, like a city ship. It moves from system to system every few years in a circuit around the galaxy. Because of FTL where it's located doesn't make a huge amount of difference, so it moves around as a way to be close to the people and see what conditions are like in different parts of the galaxy, and so that there is no "back end of the galaxy". Eventually all systems will be at least a couple jumps away from the capital, and the potential increase in trade that comes with that will be a boost to their economies. When the capital eventually moves away you'll still have people that will order your fine Junian brandy or what ever signature goods your system has. It could also make special trips for the purpose of disaster relief. [Answer] It's worth remembering that the galaxy is not actually flat (sounds obvious, but somehow something that almost every science fiction writer tends to forget!). So why not put it on "top" of the galactic central core. The advantage of this is that you would then have direct line of sight (and presumably, travel) with every other star in the galaxy, minus the blind spot "beneath" the galactic central core, which, while a large volume of space, will be less densely filled with stars than the galactic disc. [](https://i.stack.imgur.com/qlfdB.png) [Answer] How about a virtual capital planet? The planet does not physically exist anywhere, instead it exists in the galactic web as a VR world. If you have FTL travel, you have FTL communication too. * It is instantly accessible from anywhere in the galaxy. * Local resources are not an issue. * Physical safety is not an issue, as visitors, delegates, counsellors, diplomats, politicians and all other galactic servants remain at home in their nice safe home environments. As it is hosted across a distributed network, by all of the member systems, it gets all the redundancy and resilience that comes with that, but ... cyber security might be a problem. 404 error: government not found. [Answer] I think it depends on whether you want the capital to be one which is created or organic. ## Created "Artificial" capital If it's created, I'd personally go about fleshing out how the republic was formed, since balancing the various power blocs that will emerge within any political entity is a vital element of working out where the capital will be placed. If the republic came about as a conglomeration of smaller pre-existing states with their own capitals and one was elected, remember its more likely that the one picked was either the most powerful (politically, militarily, economically, or all three) or the "Least Worst Choice" for everybody else. Alternatively, was the capital placed somewhere like with the formation of the USA and their creation of Washington D.C.? If you're literally creating one from scratch, was it an existing well populated planet or was some backwater planet elevated or colonized planet colonized? ## Organic "Historical Artifact" capital If the capital became such organically, you'll need to think about how the galactic republic was formed - Did it come about as an organic growth of colonies from a primary planet? If you did this, create a map and use how your FTL works to work out what shape you want your republic to be and place your capital where it makes the most sense. ## Other things to consider Remember in real life that a lot of capitals are also ports whilst others are historical noble strongholds, or economically superior to other areas in some way. Almost all of them are where they are due to historical politics and war, and a lot of these historical political reasons for being the capital no longer exist, replaced instead by the inherent power of being a capital. Also, if you look at where capitals are on a map, they are very rarely dead centre geographically in the country - instead they are often in places which bring power economically so consider this too. Also bear in mind that any travel routes will span out from this location like the centre of a spiders web. You'll also need to bear in mind how your FTL works as this will affect the politics. "FTL Corridors" will mean that the capital is more likely to be at a big junction. IF it's gates, you'll need somewhere you can have lots of them. Also, does your story need it to be accessible or inaccessible? As for balance - don't worry too much about "creating a prosperous bubble that could alienate other parts of the republic" - This is going to happen in a realistic system wherever you put it. As a rule, the closer you are to a centre of power, the higher likelihood there is of being "prosperous". [Answer] In my case, I would go with a capital chain instead of one particular capital. Consider something like this (GC is the galactic core but the range shown is not the actual size, but instead the danger zone of it): [](https://i.stack.imgur.com/lmjb5m.png) Those little dots could be capitals which are spread across the galaxy, instead of being in just one place. Since those capitals are planets and not tiny ships, they could have huge versions of the engines that the ships had and therefore, allow travel at speeds that exceed the limit proposed for ships. Since we're not going for scientific accuracy, it could even be a matter of seconds with something like a stargate. We could even go one step further and allow time travel instead. Travelling from one stargate to another could feel like two weeks to you (which is in the confines of your travel times) but it would be a matter of seconds for everyone else (this would also solve supply line problems, since materials aren't living beings). Heck, why not give ships a small version of this time travelling engine, in turn giving them the ability to dodge shots from time to time (since space combat is usually utterly boring when capital ships are involved). [Answer] You are correct that a central location may be the most practical location because it provides the minimum average distance to all occupied stellar systems. This is the approach followed in placing Coruscant (from "Star Wars") and Trantor (from Asimov's "Foundation" series) both near the center of the galaxy. Later in the "Foundation" series the galactic capital was moved on the outer rim. Huh? In the real world, no capitals are located in the center of a nation because because the center of most nations does not border the ocean and is therefore relatively inaccessible. Does your faster-than-light travel rely on hyperspace routes, natural wormholes, or any other transportation corridors? If so, the capital city should be located on one of these avenues of travel. Historically, the most important resource capital cities have needed access to is food shipments. If your stories revolve around a single resource like Frank Herbert's "Dune" or Hubbard's "Battlefield Earth" then, your capital should be located somewhere with good access to that resource. But practicality is only one reason for a capital to be located somewhere. Most capitals get their location from political histories. Rome was the capital of the Roman Empire because the city of Rome conquered the Mediterranean. If Carthage had defeated Rome then the Mediterranean Empire would have located it's capital in Carthage. The capital of China has moved between Beijing, Nanjing and other cities depending on who had won the last war. This is the same reason why the capital of India used to be London. The capital of the United States is located in Washington D.C. as part of a political deal worked out during the founding of the country. The headquarters of the United Nations is located in New York City on the opposite side of the planet from most of our population because the United Nations was founded by the United States in the ashes of World War II. Jerusalem is the capital of Israel for religious reasons. So the real question to ask is "Where did this galactic republic come from?" Did it evolve in a slow democratic transition from a galactic empire? If so then the capital should be the cultural center of whatever federation initially conquered the galaxy. Did your galactic republic form from a confederacy like the USA? Then it should be located somewhere politically advantageous to the founders of that confederacy. Did the republic evolve out of an idealistic transnational organization like the United Nations or European Union? Then it should be located at whatever the liberal capital of the galaxy was at the time this organization was founded. Is the galactic republic dominated by certain ethnic groups? Then the capitol should be located near the population centers of those ethnic groups. These are just a few or the reasons capitals are located where they are on Earth. In a science fiction setting, capitals can be located in places for other reasons. Perhaps you want to place a capital far away from threatening aliens so it'll be safe. Perhaps you want to place the capital close to aliens so that you can communicate easily. Maybe the capitol should be Earth because it's where people came from (this will put it near the outer rim). Maybe your capital should be strategically positioned near the location of a recently suppressed rebellion. In summary, where did this galactic republic come from and who's pulling the strings? The location of the capital will tell others what is important to the inhabitants of the galaxy. [Answer] Consider the history of your spacefaring race, and where they started from. For example, if humans were to colonise the galaxy using FTL, it is likely that Earth would be the capital for at least a few centuries. It would be a huge shift of economics and ideals to move the seat of government away from its historical roots. It could happen, but only if the reasons were monumentally large, such as massive destruction of the home planet's ecology. But it would take a long time for various colonies to even reach viable population sizes, and while that is happening the government would be on the home planet and everyone would become happy with that arrangement (hopefully). But maybe in your galaxy, colonisation was long ago. You may have people with ties to the 'home' planet, but many individuals who have never been there and want the capital to be somewhere with more resources (assuming the home planet is becoming somewhat exhausted). If there is rebellion, a new capital will likely be formed in the richest location held by the rebels, as government needs resources to function and for protection. Or maybe the colonies operated on their own for a while before joining back into an empire. In this scenario, there may well have been a vote. You could draw parallels with young federal democracies - the US and Australia. As noted in another answer on this page, the US capital is not in a great position but was located where it is to be independent of the states. The Australian capital Canberra is likewise located in no-man's land - an artificially located city in the mountains between the two states most powerful at the time of federation. The only people who live or work there are part of the government, and the city is rather small. Your capital, if placed by election of federating systems, may well be placed in an otherwise uninhabited system close enough to economic hubs to be useful, but in a location that noone needs to go to apart from running the government. It makes security a bit easier if there is no usual through traffic. In terms of Star Wars, think you could use the security planet in Rogue One as an example. Low population focused on a single task, secure, out of the way. (yes this wasn't a seat of government, but it reminds me of Canberra other than the beaches). Once you've written the history of your galaxy, it might be clear that the capital would have been located in different places at different times in history. [Answer] At *none* of these places forever, but at *all* of them for some time each. *Assumption*: Based on your mention of [Star Wars](http://tvtropes.org/pmwiki/pmwiki.php/Franchise/StarWars) I took the liberty to assume a similarly structured universe/empire. Thus you will likely divide your realm into smaller regions/counties/cantons that will each have a local capital responsible for day-to-day government, etc1. These *stellar-regions* will then be governed by your central government. Now instead of creating a fix seat of government, **you have it moving between the regional capitals**. Thus every region will be seat of the government once in a while and the officials have it easier to address local issues as they're *where the action's at*. --- *On Regional Capitals*: While we have decided that the *Capital of the Universe* shall not be fixed, but moving between the capitals of its stellar-regions, the question arises:  Where are the capitals of *these* smaller regions? That hugely depends on the internal structure of the empire. Depending on the amount of autonomy granted to the *stellar-regions* there's two extreme cases to consider: **Absolute Empire**: There's almost no autonomy for the stellar-regions, their capitals are in the stellarographical2 center of each region, resulting in an approximation of spheres for each region with artificially generated prosperity at the center due to the location of government. This would allows for even travel-times between the capital of a region and their outermost stars. **Loose Confederation**: The stellar-regions are left to themselves for their internal decision-making and the galactic government will busy itself with managing inter-regional affairs as well as supra-galactic matters. The capitals of each region will likely end up wherever there's the most profit to be made, be it due to a planet sitting at the crossroads of many interstellar trading routes, or on a planet being the only source of a [very exotic good](https://en.wikipedia.org/wiki/Arrakis) the rest of the galaxy is keen on buying. This can, at the worst, lead to some star-systems being almost cut off from their capitals, which is a point you mention in your question. This issue could be counteracted by reassigning systems to other regions, creating smaller fringe regions, or even splitting the whole region down another level. All-in-all there's sadly no perfect answer of: *Put every capital at that location*, but it rather needs a gauging of each region and its members. Some regions might profit from having the capital at their stellarographic centerpoint, others will benefit from their capital in a dense cluster at the rimward end of their dominion. Nonetheless, the advantage we gain from a moving galactic capital allows us to actually handle each region on a case-by-case basis as we can break down our *big* problem to *smaller* problems where the negative impact can be more easily off-set and handled. --- This idea is not new at all. I rather cheekily stole it from my home country of [Switzerland](https://en.wikipedia.org/wiki/Switzerland), where this was a practice back when the country was younger and more or less a [confederation](https://en.wikipedia.org/wiki/Confederation). 1Rinse and repeat until you've got the desired granularity 2A pun on the words *stellar* and *geographical*; I don't know why I felt the need to explain that [Answer] My first intention was to say, put it in the middle of the galaxy, but will result in some minor technical problems, namely very high density of stars making traveling nearly impossible to calculate and a black hole, which is most likely to reside at the center. The center of the galaxy should be somewhere close to the center and if possible close to major traffic / hyperspace routes. And will cover a whole planet, because unless you will make it a government planet only and put each and every resident on the other planets inside the solar system. You can compare the population of a capitel, e.g. Helsinki with the whole population of Finland and then scale the numbers up to galactic level. But: One capital for the whole galaxy is a bit optimistic. You have thousands of planets, with each planet sending maybe 10 senators, the chamber of government will be pretty crowded and due to the fact, that they're not just in for the cookies, but real problems, there'll be endless discussions with no fast solutions. So you also need to establish local governments, cluster based, for example, where only say 100 planet governments are involved. This way, the government is never far away and decisions can be made relatively fast for local issues and galactic wide problems can still be discussed on the main planet. # Edit: But don't elect a capitol every 4-50 years. Moving a capital from one planet to the other is a really, really big effort in finance and security. Germany had this in the past, because the Federal Republic had the capital Bonn and they decided to move back to Berlin in the 1990s. It was a hell of a mess and isn't yet completed. Now imagine this in a galaxy ration, where you also have to keep business running during the move. [Answer] **Nowhere/Oxymoron** A pan-galactic society would presumably have FTL travel, hence FTL communications and thus no need for a capital location. [Answer] What is the Capital? What is the structure of the government? How autonomic the planets are? I assume that the republic takes a role where it leaves planets highly autonomic, because you can see that already with federations built of states like USA, Russia, even at the size of Germany. Although it varies which tasks are left to the states. What is the identity of the people? Best comparison would be EU vs. USA. No one in EU thinks that they are an european, that is not even a word, but in USA it would be similarly absurd for the person from California to say that he is a californian. I do not think that a capital is necessarily the economic center; think for example Washington D.C. and New York. As a political center normal people have no need to travel there, so it may stay anywhere. Of course if the republic has enemies, it would make sense to maximize the minimum travel to capital from the edge of the galaxy. During Napoleonic era forts were placed within central strategic locations. Bit similar to military bases nowadays, but more concrete in a few way of interpretation :D. They were massive investments, which greatly increased the military presence of a nation. If your republic would have few such, it would not need to centralize its military power in a one location. Business centers are likely to be born close to materials. This is if we do not assume a path dependency that some state would have superior infrastructure for refining just because of that state having been rich previously. [Answer] Ideally you'd select a planet in a Multi-stellar cluster to maximise daylight hours. This will likely be a political/economic center rather than a residential, after all. At the same time, you'd do well to elect a planet with a large amount of moons - the more the better. Not only do high-mass satelites improve the orbital stability of the core body, but they also provide room for expansion and a minor form of protection from stray killer-meteors by providing a network of deflecting gravity slings. Finally, you'd do well to pick a planet that is located at least semi-centrally while putting effort into building any other large outposts near the galactic rim. This will be the most effective way to balance the spatial appeal evenly across the whole empire. [Answer] If only **one specie**: Then probably their planet of origin could be a fair choice as it will have all the natural support for most sustainable life. Also the species would be more aware of the environment and the laws of physics and the nature. This gives the planet of origin an edge over other planets where life sustainable conditions have to be pretty much artificial. In case of an **inter-species** galaxy(several species spread across the galaxy): In this case the most collaborated and sustainable places can be chosen to be the capital. Although due to the motions of planets, sun and the galaxy itself, I like the idea of electing a capital after some time. If these planetary motions don't have much or many variations in terms of conditions of sustaining life then setting selecting two or three capitals and each capital working for fixed amount of time could be a good choice. For example it its too cold in one place for some time but good conditions during some other time, some other planets could be a choice for that duration. After all races will go to other planets to sustain their life and knowledge. [Answer] If you have sufficiently high technology, why not move the capital planet into some kind of hyperspace bubble. Connect that bubble to the rest of the universe by hyperspace tunnels/wormholes/jump gates. Makes the capital be placed 'nowhere', but reachable from every major system that has an appropriate jump gate. [Answer] A galactic government would probably be extremely complicated. if the galaxy far, far away is similar to our galaxy the galactic republic will probably control about a hundred billion (100,000,000,000) solar systems with colonies and/or mining operations. I suspect that the government will have many levels of government. For example there could be 10 sub-presidents under the galactic president, each 10 sub-president in charge of 10,000,000,000 solar systems. There could be 100 sub-sub-presidents each ruling 1,000,000,000 star systems, and under them 1,000 sub-sub-sub-presidents each ruling 100,000,000 star systems, and so on down to 100,000,000,000 sub-sub-sub-sub-sub-sub-sub-sub-sub-sub-sub-presidents each ruling a single star system and their subordinates. And each government unit in each of those 12 levels of government will have a capital. I suppose that you could write a 12 books series about an official who starts out working in the capital city of a single star systems and thinks that capital is the most glorious city ever built. And if that system has been colonized for centuries or millennia it's capital city is likely to greater than any city now on Earth. In the next book he works in the capital city of ten star systems and thinks that city must be the greatest ever. And so on in every city he works in. And in every city he works in he is annoyed that some officials who have worked in higher level capital cities think the city he presently works in is some dull little hick town compared to higher level capital cities. I am only familiar with the US system with merely four levels of government - federal, state, county, and municipal- so I can't imagine the distribution of functions in a government that has 12 levels starting with solar system government at the bottom! Thus I suppose that only a few functions would be reserved for the central government, and thus there might be only a few trillion bureaucrats and lected officials working at the capital city of the entire galactic republic, and thus it is possible they might all be able to live and work and be outnumbered many times by other people all within the countless billions of space habitats constructed in a single solar system. Most government officials in the galactic republic would work in the capital cities of the many individual governments in the 11 lower levels of government. Those capital cities would be scattered all over the galaxy and those levels of government would have most government functions. Thus it would not matter much were the central capital was located because the top level of government would have very few functions and thus its capital could be as modest as described in the previous paragraph. [Answer] **Capitals move, so lets assume your history allows for resettlement of the capital** [Countries on Earth have moved their capitals](https://www.telegraph.co.uk/travel/lists/countries-that-moved-capital-city/). The reasons range from the need to mediate organizational bickering to totalitarian vanity to the simple requirements of logistics. So, it's completely legitimate for you to seek the best possible location for your galactic capital. What you want is a globular star cluster near the center of the galaxy. Far enough away from the center to not be subject to the radioactive rage of the core, but as close as possible to minimize travel (distance wise, and hopefully gravity wise) to all other parts of the galaxy. A cluster not unlike [Omega Centauri](https://freestarcharts.com/ngc-5139), but within the galaxy rather than without. The point is, you want a significant density of stars in a small region such that the galactic capital has access to tremendous resources and reasonably direct control over a substantial population. Why? Because when those pesky rebels at the corners of the empire start chaffing, you want a huge power base to draw from in terms of both men and industry. To paraphrase historian Shelby Foote. There was never any hope the South could win the U.S. Civil War. The North had so many people and so much industry that it was proverbially fighting with one hand behind its back. Whole regiments in the North survived the entire war without ever hearing a shot fired in anger. Had the South been more successful, the North would have simply brought out that other arm. That's the kind of leverage you want, and therefore the kind of location. A globular cluster located near the center to minimize travel and maximize resources. *Note, my understanding of globular clusters is, regrettably, limited, and they may fail your test for stability (stellar collisions).* ]

[Question] [ In this world, a few hundred years have gone by since the invention of the first computer and the field of CS has been developed to the point were people are hardly aware hardware exists. Most people are raised in a environment were virtual reality and networks are built upon so many layers of abstraction (hardware -> opcodes -> the os -> applications -> display devices ->interactive realistic 3d worlds etc...) that being aware of things like how the hardware works or how different parts of the os work together has become rare. My question is: How would developers (specifically "low level" system developers who have to take into account hardware issues as well as application issues) be taught to know and mentally picture how different parts of the software and hardware work together, since they were used to strong sensorial illusions from computers and lots of abstraction layers? Precisions: * the governments in this world are very intent on giving good education to people. * People who lived through the years of the first operating systems and programming techniques are (understandably) not alive anymore as well as people who knew the computers from our day (with 2d screens keyboards etc...) Motivation for this question: It seems to me that it is already difficult for people to understand the "inner workings" of current day software and hardware (what really is an os, what happens when my program runs etc...) and to "go down" the abstraction layers built by previous developers, so I wondered how people in this futuristic world would even manage with no "original developers" left to explain things and so many abstraction layers. Edit: This question is not about people "knowing everything" it's about them knowing enough about how their programs actually work to do things like debug their programs if the issue is caused by "lower level" components. [Answer] # Complexity is compartmentalized It used to be that one person could know everything and write a book about it, like Aristotle or St. Isidore. Even after the scientific revolution began, certain polymaths like Newton and Humboldt could make significant advances in multiple fields. As late as the early 20th century, biologists like Fisher and even brewers like Student/William Gosset were making important discoveries in statistics. That is not the case any more. Lone geniuses (genii?) are no longer making cutting edge discoveries in multiple fields. In fact, the leading edge of modern physics and medicine is more collaborative than ever, with teams of up to hundreds of specialists combining their expertise to unravel particularly complex problems. So the solution to teaching people really advanced sciences is to teach an ever narrower band of topics. Already, subjects like Chemistry or Statistics are simply too broad for one person to be an 'expert' in everything. Statisticians specialize in machine learning, or neural networks, or bayesian theory or whatever. So to apply this specifically to your problem, computer knowledge is already compartmentalized. The people who build processors at Intel are not the same people who build operating systems, who are not the same people that develop programming languages, who are not the same people who build webserver software, who are not even the same people who build webpages. If it becomes increasingly complex in the future, it will just be compartmentalized more. [Answer] As a programmer maybe I can contribute something here. How do we do it today? Systems are already incredibly sophisticated and there are so many technologies and programming languages available to choose from. How could anyone who calls themself a programmer could possibly know all these things? They don't, put simply. There are already abstract layers upon abstract layers that hides a vast majority of the complexity. Most programmers are explained at the basic level how computer hardware works, but it isn't like most programmers could necessarily create you a circuit with a soldering iron and a breadboard. Nor do programmers *need* to know this because it is all abstracted away. If they *did* need to know these things, there wouldn't be a programmer in the world who has programmed in a language more complicated than assembly (one step away from machine code). But wait, *somebody* has to know how this stuff works, right? Yes, of course. This is precisely my point. The modern model of the computer has been pretty much solidified in the 1960s and 1970s (albeit they've gotten a lot smaller since). So while I won't say most of the original creators of the modern computer have died, if they're not they're most certainly in retirement. The ones who have inherited this knowledge from their predecessors are working today doing what they do best, most likely trying to figure out ways of creating a computer program that can create a chip layout that is increasingly reduced in size and more powerful than the previous. They don't solder circuits by hand, but they still know intimately this aspect of their job because this knowledge still comes in handy. Granted, computers do much of this sort of reasoning for them, but lets just say that there are people who know what is needed to be known in order to create the technology we use everyday. If there weren't such people, the technology would not be present. To claim the contrary would be a bit like saying there could be tomatoes in the marketplace and no tomato plants. Again, this isn't to say that you couldn't walk the streets without bumping into one such person, but they'd exist in small number somewhere in such a world. Most likely, if the world were post-apocalyptic, they'd be looking out for their own best interests as well by doing so. [Answer] As somebody who studies electrical engineering with a focus on hardware development i can tell you that in this specific field of **computer architecture** software and hardware development are closely intertwined. Of course there is the high-end hardware people who do nothing but that and the high-end software people who don't know what their hardware looks like, but there is a whole field of study between them. Computer architecture is a very important field that will not die out just because most people have to do with software. You can simply not have a world that is so incredibly high-tech if there is no one there who can build the technology that world requires. You don't even need that many people for something like that. If you compare the amount of people who know how to code software with the amount of people who can design hardware there is already a ratio of 100 to 1 if not less. Computer architecture won't die out in a world like this. Just like physics, chemistry, mechanical engineering and medicine will not die out. It will still be tought the way it is now. **Regarding how it will be taught:** * The basics of logic and boolean algebra is something software developers learn, too. * There are special lectures in universities about all the different aspects of computer architecture * Those lectures include basic digital systems and then get more specialised to "simple" processor structures, to elaborate multi-core architectures and then to high-end parallel processors Unless we have a huge leap in technology and computers work entirely different from current ones (e.g. quantum computers) there won't be anything different about teaching that. But if there is such a change (which is likely, to a degree) we can not predict what will have to be taught then. fact is, the basics of logic and simple processor will most likely still be relevant to the curriculum. --- **Bonus:** Just to compare google search results: * "vhdl tutorial": 418,000 (Hardware) * "verilog tutorial": 398,000 (Hardware) * "c tutorial": 253,000,000 * "c++ tutorial": 15,400,000 * "python tutorial": 31,000,000 * "java tutorial": 58,000,000 * "javascript tutorial": 64,000,000 * "c# tutorial": 6,700,000 * "fortran tutorial": 493,000 note: there are not really other used hardware description languages than verilog and vhdl [Answer] At some point they wouldn't. Making better hardware is essentially an optimization problem, and it turns out computers are getting VERY good at that. Additionally, we are reaching the end of the line when it comes to silicone chips; we can't make transistors much smaller, and that's a physics barrier, not a manufacturing barrier. Writing code for specific hardware is already abstracted away from programmers with compilers. As soon as computers start engineering the hardware, it's not really all that difficult to have them generate the compiler as well. This all sounds like serious science fiction, but it's actually closer for real humans than you might think. Many experts say we'll see computers become better than humans at coding within the next 50 years, and as someone who works in machine learning, I honestly think it might be quicker. The trend for programming languages today is to make them more "readable". That is, you shouldn't have to worry about how you write your code, only what you're trying to accomplish. The computer will take it from there. There are already great strides being made in this area, frameworks like Spark build intricate data structures describing how a program will run and then immediately optimize them so that you're (nearly) guaranteed to have the most efficient program at the end of it. The logical next step is to remove the programming aspect altogether. In the future we'll likely program the same way people make their own webpages with things like weebly. The important thing will not be how the program is run, but what we want it to do. This change will make the process incredibly simple and within the reach of pretty much everyone. And this is all within the next century. What the next few centuries will bring, I can hardly guess, but likely computers will take over the entire job end-to-end. People won't need to know how the computers work behind the scenes, and it will likely be too complicated for us to even understand. [Answer] As an IT professional since the 1980s, I can extrapolate on what I've seen. Their will be levels of difficulty with fewer and fewer at the lower levels. **High-level languages** will likely be entirely GUI and menu driven. Imaging working on a tablet, dragging things around, and selecting options, as you set up your calendar. This is how the majority of programming will be done. **mid level languages** will likely be variants of what we know as "object oriented" programming today, ranging from the low end, which would have a degree of customization, to the higher end of mid-level having little control, but plenty of pre-made objects and a drag and drop interface. A smaller, but still sizable population will still be taught this. **Lower level languages** will be taught to very few people. These will have high complexity and control, but will be needed to help do the "behind the scenes" work of the higher level ones, and to make new advancements in the higher level one. **VERY low level languages and operations** will be taught to and known by a select few. There may even be restrictions on who learns these. These will be the operations level, difficult to learn, very powerful base-level programming/networking/database/back-end skills. Highly valued, and highly dangerous to a world where technology runs everything. Most High-level people, if not all of them, will never have any exposure to this level of sophistication at all. Likely, people will be tracked at an early age to one of these tiers of complexity, based on skill, potential, and psychological stability (you don't want someone crazy to have the power to essentially flip the "off" switch on civilization) [Answer] In a very advanced world, quite likely people would no longer bother with the nuts and bolts as AI systems would handle it. As the level of complexity increase, it would become harder and harder to understand it all and as such people would develop systems to help to automate development. Programming using an AI development tool would be talking to the computer describing what you want to do and guiding the AI's solution. In all likelihood would be done using natural language. Software programming is already one of the [jobs slated to be replaced by AI](https://www.computerworld.com/article/3041430/it-careers/one-in-three-developers-fear-ai-will-replace-them.html) Sure people could dig into the nuts and bolts of it all but it will be highly unlikely and more than likely a hobby or personal interest. People will be unlikely to do so professionally because an AI will be able to the job better and faster. [Answer] There are already some very good answers here, but there's still one missing: people teach themselves. As a computer programmer and hardware tech with years of experience in each field and even some college level education, I've taught myself way more than any school did, in respects to computer tech. From my first programming "class" after school during my 8th grade year, to my first foray into hardware, I used information I learned on my own to get things done. Even as a college student, I taught myself more about my computer classes than the instructor covered. As a professional, I use Google, YouTube, and other places (like SE) to teach myself how things work and how to improve my knowledge of the various topics I'm interested in. I can imagine people in the future (still) popping off the covers to their VR gear (or whatever tech) and trying to figure out "what makes it tick." They'll do their own research, and even today there's a vast amount of technical knowledge to be easily found online. I know I did that sort of thing as a kid and I still do it as an adult. There will always be higher learning available to teach these things, and it usually funnels people where they want to go. This kind of training often starts at the easy stuff and works toward harder concepts, so people will stop when they get to their goal. The future may only have small amounts of people wanting to get into the "deep dark recesses" of computer tech, so it may end up being a 1-on-1 teaching/mentoring situation, like blacksmiths. Some of this is currently done, with topics that are so specialized that only a tiny handful of people a year are interested in studying it. And at this level of teaching, much of it is still done through self teaching. The people at the top of their fields have to teach themselves, since there's so very few people they can draw new information from that they don't already have. There will also be people who just do things on their own, without worrying about classical schooling. I didn't finish my computer engineering degree, but I've still had +15 years worth of computer tech jobs, +5 years of programming jobs, and I've built many machines that aren't computers, including a 4'x8' capacity CNC machine. That CNC machine was my first attempt at building a CNC, first use of an Arduino (it currently uses 1 Uno and 1 Mega), and first use of a Raspberry Pi. I did it based on "it can't be that hard" and guidance by the people around me at my local maker space. Maker spaces can be a springboard to learning topics that become people's careers. Four years ago when I joined the maker space, another member was a young man in high school, and he was designing & building 3D printers plus learning the Occulus Rift (VR googles). He is now a virtual reality programmer with no degree and most likely making way more money than I am. He started college, but was offered the job he's at now before he got very far, so he quit school. So, to directly answer the question of "how would developers {...} be taught to know and mentally picture...": they teach themselves. They are given the right/all information, the right mentors, the right source material, and the right to forge their own path. They will also need to have the right to make mistakes along the way, since the strong push towards perfection in today's (American/"modern") society is killing people's personal motivation, or driving them insane, but that's a different topic. And (maybe most importantly) you also need to be able to have not just the access to the "right stuff", but you also need to have the time and energy to do it. Scraping for or scratching out a living doesn't exactly give you the ability to do any learning, regardless of how many informational resources are available. Getting stuck in a job(s) that takes all your energy and doesn't leave you any free time is even worse (IMO) than having to pay out the nose for a degree. Been there, done that, and didn't like it (both getting stuck in survive mode as well as paying a lot of money for a degree). [Answer] I'm going to go with a different answer. Beyond a certain point of advancement; we would stop programming computers, and we would start teaching computers. Computers would have a built-in AI that has a general-purpose 'programming' algorithm, that allows them to create perfectly optimised code to solve any problems; after a while, it would become impossible for humans to understand the low-level programming. Once this algorithm exists, human programmers as we know them today would become redundant, and be replaced with people who are adept at training. Look at the language around 'Robotic Process Automation' today. Already we're seeing generic systems that can be 'taught' by a non-programmer to complete simple tasks, without any need to understand the underlying programming languages involved. [Answer] But, this is happening **today**! You see, a lot of the current software development is in Java. Java code gets compiled to byte code, which runs on a **virtual machine**. Then, there is some kind of **runtime**, most likely written in C or C++, that simulates this virtual machine on the fly. This runtime runs as a process within a **virtual execution environment** (virtual address space, no access to any hardware except the CPU). This virtual execution environment is created by the OS kernel, which **thinks** it has full control over the hardware. Except that there are parts in the hardware itself (UEFI, System Management Mode, Intels Management Engine, AMDs whatever), that can control the kernel, possibly, the kernel is actually executing **inside another virtual machine**... (we are running in circles, aren't we?) You see, layers and layers of abstraction, and where is the actual hardware? Only preciously few people know. If you just ask the average programmer, they won't even have a clue how their processes manage to write some data to a file. They won't even know, how their request can actually leave the process's virtual execution environment. Even a C programming crack does not necessarily know this, as it's not even a part of the C language! Even people like the kernel hackers do not really see the hardware, they only see the abstractions built by the hardware. It's turtles all the way down... That said, it is not impossible to teach people the principles that are repeated over and over again to create this monstrous stack of abstractions. You see, there's not so much difference between a process executing a trap to call into the kernel, and the kernel performing a seeming hardware action that traps into its hyper-visor. It's pretty much the same mechanism repeated at different levels. It is also possible to teach students, how you can build a CPU from parts like registers and arithmetic units, and how these are built from individual gates, and how these are built from individual transistors. As such, it is still possible to know all the principles of the full stack. However, for the vast majority of programmers, knowing the full stack is not their concern. Programmers tend to work at a specific level, deepen their knowledge at that particular level, and thus act their role in the big play that's called the "[division of labour](https://en.wikipedia.org/wiki/Division_of_labour)" --- The same will apply in your setting. Just much more abstraction levels, and much less people caring about hardware. You might still stumble across the odd individual that cares so much about abstractions that they actually know the principles of all the abstraction levels involved. But these individuals will not be of much use to any company, as they won't be able to outperform the various level specific experts. In any case, the secret services will likely be the ones with the deepest knowledge of the different abstraction levels involved: Each lower level may serve as a back-door into the next higher level. Now, computers are connected at the most basic levels (electro magnetic radiation, or even *wires*), but the interesting stuff happens at the highest levels (Alice sending Bob some message with interesting stuff in it). So, secret services will want to attack at the lowest levels where their intrusion remains invisible to virtually anybody, but be able to hack their way up through the entire stack to get to the actual contents of the digital communication. Again, **this is happening today**. As such, you have to expect the secret services to have their hands/back-doors in every level that IT experts come up with. Right from the definitions of the relevant standards to the actual implementations. They are likely the secret rulers of the world. They are the ones that can find out about anything they happen to care about, and they are the ones that can blackmail anyone (its possible to prove anything about anyone if you have write access to all their devices/accounts). This is especially true, if law enforcement relies on prescribed governmental back-doors. It won't be just the police that has access, and the access by the secret services won't be read-only. No government will be able to control them. [Answer] As someone in the IT industry with experience in several stacks (OS support, hardware support, database management, programming, etc.), I can say that it's extremely rare for anyone in my industry to have a full grasp of how things work at various layers. Instead, you find niches. Someone who is a life-long programmer tends to gravitate towards specific kinds of programming and get *really good* at that kind of programming. But they usually don't need to do deep dives into how their compiler converts [popular programming language of the year] into machine code or how that machine code connects directly into the CPU to drive events at the hardware layer. Just like your typical auto mechanic may be an absolute wiz at fixing brakes or changing tires or etc., but probably isn't that well versed on the science going on in your car's internal computer to improve the fuel economy. And that engineer who's tweaking the systems to improve your fuel economy may not have a clue how to know when you need to change the spark plugs in your car... So in your typical cyberpunk universe, most programmers are working in languages so far removed from the hardware that they don't need to know how the hardware really talks to the language's interpreters. They couldn't care less, because it's not important to their work. They work in the virtual world universe and never need to figure out how the hardware converts that universe back and forth between graphics and binary (or the [qubits](https://en.wikipedia.org/wiki/Qubit) of quantum computers, if that's what drives your cyberpunk systems...) If your programmer is professionally / college trained, she probably attended an undergraduate course somewhere that explained the theory behind how their programming languages work at the deeper layers. If she actually learned that material, then she probably knows more about it, but doesn't need that knowledge to actually do the job. Most cyber fiction (RPGs included) don't really assume your characters are formally trained. But at the companies that make your cyber decks or whatever they're called, there are teams who are experts in those deeper layers. These folks write the translation protocols and [APIs](https://en.wikipedia.org/wiki/Application_programming_interface) that convert between the mainstream VR languages and the hardware-specific stuff their products can understand. They publish the OS for your decks along with whatever tools are required to merge those VR languages with their OS / their decks. These teams are similar to the folks who still work in [Assembly](https://en.wikipedia.org/wiki/Assembly_language) languages today to interface between the hardware and the more popular languages and systems people use. Not many people know these low-level languages, but there's still a demand for that skill set. Maybe they only write enough of those low-level languages to interface between the hardware and higher languages, but that's still a thing. (See also the engineers who design the CPUs and other complex chips inside computers, and then have to provide sufficient interfaces for programmers to connect to them.) --- The other pathway is that, at some point, AIs started taking over the creation and maintenance of those extremely low-level languages. Maybe the AIs develop the newer generations of CPUs, because the logic is now so complex that engineers can't do it. (Or can't do it fast enough to be competitive in the computer marketplace.) Once that happens, maybe the AIs also have to provide the lowest level software as well, since no humans truly understand the hardware in depth anymore. [Answer] I agree with what many wrote here on stacks and hierarchies. A small, but hopefully, fruitful addendum: # You are not discouraged to go deeper Of course, everyone in your world is programming with VR-based "Minority report"-style hoola-hoola. But if someone wants to go down to a graphics API (that is also used and abtracted by VR-hoola-hoola), she is free to do so. Of course, if their task is common enough, it would have been already implemented and "going deeper" is a waste of time. If they know better, have a new idea, want to implement a novel algorithm or are simply THAT out of the box, that the task is not implemented yet on the high level – in all these (seldom) cases, peeling away a level of abstraction might be beneficial. I have seen a few times the idea that "old tech" is frowned upon in dystopian sci-fi. The modern reality is that old tech either gets deprecated or *still* runs somewhere down in the pipeline. Of course, the deeper you go, the more expertise you need. But you can get it the usual way, by reading smart texts and trial-and-error. To give a few examples: Markdown (which we use here for typesetting) is cool, but if you want it to make a PDF, it goes via LaTeX, a dinasaur from 80's and 90's. The coolest, best, and fastest Python library for doing proper maths is `numpy`. It is the way I write some math-related small scripts, and I dare say I know a bit of the trade. `numpy` relies on some codes that need to be compiled in Fortran. Fortran! [Answer] As of now, you have **no** chance to even understand at a decent level everything going on on your computer. When I grew up (late 80s/early 90s), it was different. My CP/M microcomputer (8bit) had a grand total of 64kb of RAM. Operating system was probably on the order of 10,000 statements. At 50 lines/page, that's 200 pages. A book you can read over a few months and understand from scratch if you really want to. Everything else (hardware etc) was on the same order of complexity. Now it's very different. I don't even understand the **names** of all services running in the background of my computer. If a new name shows up, I have to google it to see if it's a clumsy virus (a good one would not display anything new) or just a new thing added by Microsoft. Forget about understanding how it works inside. What you do nowadays is working in your "square": You can do worldchanging AI work for Google or Facebook, and still have no understanding how the server it's running on is built. If you have specific needs (a pink-haired server let's call it), you talk to an electronics guy and ask about options for a pink-haired server. Car analogy: If it were the 1900's a car guy could be a car driver, designer and repairman, all in one. Nowadays, you are an expert in a small subsystem - say, an expert in designing wheels and tires. You have a specification (how the wheel ties in with the rest of the car and how the rubber and the steel you are using behave) but you don't understand either rubber making or "overall car design". [Answer] ## Computer programming will come to an end Computer programming is the textualized representation of commands that are both readable by humans and machines. I can't stress the importance of understanding this core concept. It's **text** that a machine can understand. It's why we call it a "language" as we must understand both what it means from a human perspective, but also what it means from the perspective of the machine. For example; ``` print "Hello World"; ``` It's a stream of text characters containing special characters, structure, format and literal values. These are then interpreted by the machine to execute a sequence of commands. Does the above source code really do what I wanted it to? The question illustrates the limits of programming. The machine has no care at all in it's meaning or purpose. This is a fundamental limitation on the use of source code to control what computers do. It's all about interpretation of what a human thought he was telling a computer to do, and the actual effect of what the computer did. If the two are not in alignment, then this is called a bug. From the perspective of the computer. It did nothing wrong. > > Most people are raised in a environment were virtual reality and networks are built upon so many layers of abstraction that being aware of things like how the hardware works or how different parts of the os work together has become rare. > > > I foresee that computer programming as we know it today would no longer exist in such an advanced computer culture. The weight of responsibilities for the humans that built the lower-level systems to maintain those systems would yield nothing but failure. ## Neural networks as a current day example We have AI networks now. You can download an AI open source library, design the inputs for a large neural network and teach it new things. Those neural networks become large complex connections of knowledge that we humans **can not** understand. There is no **text** representation of that neural network that we could read and say "oh, so that's what the computer is thinking". So from that perspective. The art of writing source code and understand the system is one day going to end. Yes, AI is a tool and there are programmers who wrote it. Over time we will have tools that are so complex and beyond our understanding that we benefit from the use of the tools rather than the understanding of them. > > How would developers (specifically "low level" system developers who have to take into account hardware issues as well as application issues) be taught to know and mentally picture how different parts of the software and hardware work together > > > I would picture such a society to have "low level" systems that are beyond human understanding. These are also systems that are the sum of their data. You could not take *new parts* and just snap together a *new system*. The existing system with it's existing data is the only system that could do that job. It is an interface problem and not a knowledge problem. These systems would have to have digital ambassadors that represent *control* over parts of the system. These would be a kind of interface that new people would be taught to interact with. Those people have the authority and power to control what those ambassadors do against the systems. The ambassadors are not people. They are software but complex software. They exist and grow in complexity as the system grows. Without the digital ambassadors a person would be unable to understand the working internals of the system. It's the ambassadors that can explain how something works from a "human perspective". > > It seems to me that it is already difficult for people to understand the "inner workings" of current day software and hardware (what really is an os, what happens when my program runs etc...) and to "go down" the abstraction layers built by previous developers > > > We today have scientists that study nature. Trying to understand how things work at different levels of scale. Such a future society would have the same kinds of people. They would perform "research" to figure out what the systems were doing, and why. I picture a world where scientists make groundbreaking discoveries on how these systems function. This allows society to give those systems more of what it needs to be more efficient. This in turn benefits the society which uses those systems. Each discovery adds to the systems and increases the complexity which yields the need for more research. People don't learn the "inner workings". They are taught the *history* of how it came to be this way. From that history is how people gain knowledge. Each step in history solves a problem which leads to the next. There is a real fear in having such a dependence upon complex technology. If you somehow were to forget the history. You also lose control over the technology. Of, if the technology was to advance faster than you can record the history you also lose control. [Answer] If you take the [singularity](https://en.wikipedia.org/wiki/Technological_singularity) seriously, you are describing what is probably a post-singularity world. In such a world, computers would be all designed by computers which were designed by computers .... (for many generations), all of whose cognitive abilities outstrip any biological character's by many, many orders of magnitude. The computers are beyond the comprehension of any strictly biological being, even those whose ancestors designed the original computers several centuries earlier. Thus it would be impossible to teach such people how these incomprehensible black boxes actually work. Furthermore, people couldn't be taught "sufficient programming skills" because no such skill that a biological entity could possess would be sufficient to program one of these computers (programming being one of those tasks taken over by advanced AI centuries earlier). Thinking that super super computers would need uber uber hackers to program them isn't a plausible way to think of what the situation will be hundreds of years in the future (in much the same way that the [terminator isn't a plausible way](https://www.xkcd.com/652/) to picture a conflict between humans and machines) [Answer] That depends on whether the society is developing or stagnating. A dynamic society, based on some ability or knowledge, has many people that develop that ability further and further. So, there will be many schools, excellent teachers and so on. If the society is stagnating, the knowledge will be closed for some IT "priests". There could be many of them, but the principle remains. The number of schools and possibility to code something new depends on the depth of the stagnation. The accepted ways will be called efficient, sufficient and so on. If somebody will try to invent something new and cannot be silented... here it depends. Fired or killed. If we remain optimistic, there could be even more open solution, that we cannot fully imagine now - computers, becoming individual factories of thoughts and even of the real production, could create a much more free society that what we have today. Of course, it will have problems of its own. As for programming - don't forget the rule - every task becomes solved and the solvers become to solve metatasks around it. A free IT society will kill finally noneffective languages with large and totally ineffective IT departments. The next move, I think? will be to teach these free coders to organize their way of thinking. It will be a great psychological problem, for they connect any way or organization with these IT monstrums. And they **"know"** that it is ineffective. I think, they will have to learn how to organize themselves. [Answer] There are many ways to go about answering this interesting question. We can try to extrapolate from what we know, with a focus on recent trends. This line of thinking is probably the most generally acceptable, even though it will certainly result in a wrong prediction of the future. Alternatively, we can try to imagine a future, based on some assumptions that we know may, or may not be correct. The question defines some of these assumptions, such as people having a need/desire to understand certain things (as opposed to leaving it to AI), that Virtual Reality networks are a thing, etc. The answer about compartmentalized complexity and an even more specialized workforce uses the first line of thinking. How have we been dealing with increasing complexity recently? We educate people with university degrees that often puts us in our early 30's, before we even begin our first attempts at contributing anything (through this archaic concept known as 'work'). One problem is that this roughly coincides with the age at which we begin becoming slower of thought, and the onset of degrading memory recall. While engineers continue to learn, long after we have finished our education and passed our prime, it is simply not feasible to continue increasing the time spent learning, relatively to the time spent 'doing', even with better health and significantly longer life expectancy. Eventually we will simply spend our entire lives learning about how a specific and narrow area of computer science works, without ever being able to comprehend enough to actually contribute anything new, without introducing an equal amount of problems, as a result of our incomplete knowledge. About compartmentalization: Similar to the problem of a more specialized workforce, we can do more, but it does not make the increase in complexity go away, and we cannot dial it up to infinity. Think of layered software architechture. We can have a huge number of layers, and while they help a great deal with complexity issues, each layer still adds some complexity. Here it is important to note, that we are talking about systems that go far beyond what we *need*, and deep into the reaches of what we are potentially capable of, a point that we already passed a long time ago. The second line of thinking places us inside a Virtual Reality world, where we experience a glitch, and poses the question: How are we going to identify and fix the glitch? Part of the answer is rooted in the fact that the VR world can only exist in the first place, if the needed skills, tools, code libraries and hardware exists. If that is the case, then there must also exist equally powerful debugging tools. Some of the answer seem to be that any modifications on an extremely complex system will be heavily assisted by the tools used to produce the system in the first place, and require highly qualified engineers. The part of the question that deals with passing on knowledge (after the creators of a system have passed) is mainly a question of being able to sort noise from valuable knowledge, and keeping a huge (and growing) amount of valuable knowledge updated. A detailed answer to this topic alone would be valuable, as it is something all engineering efforts struggle with. Writing things down and making sure there is a backup is trivial, but actually keeping the information relevant and of high quality is a major challenge. Trying to imagine this future world, knowing what we know today about AI and neural networks, and our inability as a species to stop or slow down our scientific 'progress', it is quite difficult not to think that we will make ourselves obsolete, unable to comprehend the world we live in, even when it comes to just specific systems. Consider global macro-economics as an example of this, or to stay on topic, the recent concerns about why a piece of code made a certain decision (is it a turtle or is it a gun?). [Answer] In a sufficiently advanced computer science world, you'd expect there to be uploading of people, and possibly tightly controlled "meat-space". You wouldn't experience the world unmediated; the unmediated world would be a lot like death valley crossed with a nuclear power station. The real world is dangerous to people there, uncomfortable while there, dangerous to allow idiots to run around in to everyone else. Instead, people would be uploaded and simulated. If they must visit the real world, you could download them into a meat-body for the retro-experience, or just access it "remotely" via robitic tools. In such a world, studying the low level underlying hardware and software would have a few purposes. First, it would be akin to studying fundamental physics; if you are wondering how your (virtual) world works. Second, possibly repairing and upgrading said hardware and software is a good idea. The field of study might be called "diety science"; studying how to create, maintain, and modify worlds. These people are, in sense, their own gods, making entire universes out of hardware and software. Now, unlike ourselves, these people have theoretical access to the underlying system, so they can study how the virtual universe works as a white box instead of a black one. But emergent phenomina of the underlying system might be too complex to understand via white box understanding. At modestly higher levels, computer science becomes akin the the study of physics, chemistry, the study of the world in which you are embedded within. This world would probably be designed to be pleasant, but for the most part you wouldn't want to give every user "god level" access to it for robustness sake. "Consoles" or whatever you imagine to interact with the computer would be similarly silly; if they want entertainment devices, they are just entertainment devices in this virtual world. This virtual world *might* allow something akin to scripting. Do X, and get result Y. Maybe said scripts even permit loops and other human-understandable logical constructs. Then computer scientists working on that level would resemble magicians; building spells (scripts) that do things in the virtual world. To keep things stable, the effects of scripts would be bounded based on some resource share, so script-kiddies cannot rewrite reality with ponies. Sufficiently advanced computer science is indistinguisable from a fantasy novel. In this realm, knowing how to script would be of value. Lower level theoretical computer science might be useful in finding new ways to write scripts. At some point, people in these worlds wouldn't have permission to interact with the low-level details of their world, but knowledge of them could be passed down, look up, and maybe used to find other interesting ways your user-level scripts can interact with the world. Forging new worlds might be possible (if expensive), and doing so might require knowledge of relatively low level (but higher level than any CS today) computer science to learn how to arrange rules for a stable universe to be created. The lowest level of computer science and hardware would be outside the permission scope of any mere mortal, and mainly known as a theoretical discipline. Now, you could imagine that the guardians of reality (meatspace) might die, neglect us, or whatever, and people in the virtual reality might use such low level knowledge to create scripts that violate the "safety" assumptions that where built into higher level ones (find a ring-10e7 exploit, and the effect might be similar to nuclear technology; destructive and powerful). When the caretakers notice, they can modify the underlying reality to patch the exploit, or do a rollback of universe state prior to it being used. And if you can notice that, you can exploit forcing rollbacks on universe state; make a decision contingent on the universe being rolled back. If it fails, activate a low-level exploit, cause a rollback, and make the other choice. [Answer] Abstraction has always been a corner stone of software development. Programmers only care how something works up to the point where they NEED to know how something works. Take this simple *Hello World* example in C#: ``` Console.WriteLine("Hello World!"); ``` Most programmer's know this will print "Hello World!" to the console screen. Most programmer's don't care how it does it. All they care about is that, without question, it will print "Hello World!" to the screen. So how does this work? Well, when you compile this program, it creates an EXE file that contains MSIL code. When you execute the EXE file on a Windows machine, the operating system looks at the header of the EXE file. It determines its a .NET program and it runs a JIT compiler. The JIT compiler takes the MSIL code and converts it into x86 or x64 opcodes. Since the .NET framework is written in C/C++, the JIT compiler produces code similar to this: ``` push message call _printf add esp, 4 ret message: db 'Hello world!',13,10,0 ``` The `_printf` routine is a routine in the standard C libraries. This routine uses routines found in `Kernel32.dll` to print a message, by using routines such as `Writefile`. Eventually, it all comes down to writing bytes into your video card's memory to manipulate what you see on the screen. There was a time in history when writing a simple program involved worrying about all these little details. Today, however, unless you are writing device drivers or OS Kernel code, these details aren't something the average programmer cares about or needs to worry about. [Answer] Likely you would see continuation in the divergence in specialties you are currently seeing today. Data science, Front End, Back End, etc. The evolution of programming occurs when technology is built on top of existing technology that is efficient and easy to use such that the underlying technology is no longer necessary to know. For instance: How many programmers code up servers from scratch? (so so few) [Answer] ## Tie it to something they want If you play World of Warcraft and want to win in PvP, you will learn the macro language (basically LUA). You want to turn your lights on, every home is a smart home and you better be able to write some Insteon code or you'll be freezing in the dark. We already have a programming language you need to get by, it's called English (here). [Answer] Cybernetic brain implants of language libraries, or voice-recognition software architecture. The programmer would need to scan a lot of libraries and research efficiently. The libraries would be instantly assessable, so the cause, effect, methods, of all libraries could be efficiently assessed very fast. All programming languages would have a common interface, and could be nested together effortlessly, and their cause and effect could be conceptually described in human terms and arranged into mechanisms with a human-spoken, computer written, cooperation. [Answer] I look at this as an issue with consumers vs the engineers that make it work. Today we have the OSI model, a 7 layer framework that divides computer systems in a logical progression. We already have specialists that work at different layers of the OSI model who may have some experience with other layers but are primarily focused on one or more depending on the work. The model assists in development and troubleshooting. I'm not sure we'll see a lot of changes to this. One trend in the industry is machine learning. This could drive more rapid improvement as these technologies become more mature, but the fundamentals would remain the same as long as people are in charge. If machines become responsible for development of technology and software, and aren't constrained by human oversight they may come up with something radically different, but that sounds like another story. [Answer] **Compartmentalized AI embedded in Firmware** The answer titled: "Complexity is Compartmentalized" is an excellent one, but for your purposes, I would say the answer from a world-building/sci-fi perspective would be a little more caveated. If I may take the liberty of adding a bit of "history" to your scenario: Long ago, it was determined that creating an all-knowing, "Omni-AI" was a big mistake, and in fact, dangerous. Therefore, certain AI standards, implemented as hardware modules were established to complete specific tasks. These modules are hardware based so the code cannot be altered - However, they do have an API which allows a person to interact with them. This is where the learning comes in. You can become an expert on using certain modules and becoming certified on them. Let's take "Microsoft Word" as an example. You can probably become certified on it, but you can't really change its source-code. The coding on these modules would be open-source, so as to maintain transparency, however, only a certain governing body would be able to produce authentic modules, which would be trusted in the public sphere. Therefore, for the aspiring Software Engineer, programming and development would never get any more difficult than it is now. Sure, they would have to master AI concepts, but they would be limited to gaining proficiency on select modules. [Answer] I would venture to guess that just like now days the people interested in learning this stuff will actually know about it... And with the less people knowing about this the better paid the jobs will be so the new students will be more interested in studying it. Or another alternative would be that AI would be advanced enough to design the needed hardware by itself in which case we wouldn't need people in charge of that. ]

[Question] [ First of all, yes I'm Australian, and yes I am using a kangaroo to type this up. If you take a look at Australia, it's a pretty sad place geographically. Very flat, very dry, mostly desert and for the majority of it, mostly poor, arid land that isn't farmable or inhabitable. Now, the root cause of all of this, is the huge lack of water in the center (if you look at the coastal regions, they have relatively lush landscapes). There is next to no water, EVER in the middle of Australia, due to the lack of natural rivers and the unfortunate positioning of Australia geographically. However, what if we dug a canal ourselves? Ignoring the social uproar of Indigenous peoples and other environmental and cultural preservation groups, huge canals could be dug, North to South, East to West - going through the center. These would connect to the ocean, where water would come flowing in, into the middle of Australia. The canal would be wide enough to allow for large quantities of evaporation, which would allow clouds to form locally and create rain. This would bring about fresh water to the areas close to the canal, and in return not only loosen up the soil, allow for plants to begin growing, cool down the area and allow for human habitation. Local species shouldn't be affected too much, since there would still be some desert left, and the species living inside the deserts are rather rare anyway (compared to normal, tropical areas ). In the center, there could be an extra large pool of water that would serve as a new hub for living and work, in the center of Australia which would reduce some stress off the rest of Australian land, as the large pool of water would create a larger area of rainfall. Not only would this create a large economic and social hub in the center of Australia, using it instead of it just being wasted land, it would also create usable land ALL along the canal. This allows for sustainable Australian development into the future as we have far more usable land. Is this possible? What could be some potential problems? PS : **Some common suggested issues and my counter points**: Rubbish / Crap / Protesters filling up the river - A big grate over the top to stop stuff from getting in. Excessive salt - It is connected to the ocean no? So would the salt not just become dispersed among the ocean perhaps when the tide comes/goes HEY! You can't irrigate with SALT water!! - See water will EVAPORATE with the power of the sun, meaning that it will condensate and then fall back down as fresh water in the form of rain, thus being usable. Large rain collectors can be used to capture this for a more constant water supply. The River will need to be SUPER WIDE! - Now this one, idk, however i assume that just a Km or 2 will be sufficient. The Canal will need to be SUPER DEEP! - Now this one I'm even less sure than the previous one, as we are trying to evaporate, I do not see the reason why it needs to be super deep. The Canal will ruin the water table with salt! - A concrete barrier will be placed between the canal and the ground, which also ensures less slit gets in there. ITS SO EXPENSIVE! - It will pay for itself as it will create a huge new economic hub that otherwise would've been wasted. The huge investment would also mean a colossal improvement in the economy and Australia will be better in the international light. [Answer] # A canal will not help Case in point: Here is map of a very large 'canal' in the middle of a desert: [](https://i.stack.imgur.com/fCGk7.jpg) You may notice, that despite this 'canal' being up to 350 km wide, it doesn't actually bring a lot of rain to anywhere near it. In fact, having sailed through it at times, I can confidently inform you that in the summer, the Red Sea is the worst place on Earth; unbearably hot and unbearably humid. So no, a canal will not help central Australia. Edit: Regarding salt, the north part of the Red Sea is at 4.1% total dissolved salts, compared to 3.5% in the Earth's regular oceans. So your canal would be a little saltier than the ocean, but not much. [Answer] **I think you need a mountain range, rather than a canal, to cause more Australian rainfall.** If memory serves, Australia lacks enough high mountains to induce precipitation of *already-present* moisture in the air. Instead of a canal, you'll probably get much more rainfall by creating a few mountain ranges perpendicular to the prevailing winds. I had previously pondered this for your home continent, in a story arc with some strange magic. Building mountain ranges without magic is just too !@#$% difficult, alas! [Answer] They were thinking about doing this in Florida during the 60's. So much so to the hiring of people and buying up farmland....and then...someone asked a question. What about the water table? Florida is basically a sponge of limestone under the golf courses and palm trees. If you cut across the middle, all the water leaks out in the ocean. Everything south of Orlando would become a desert because all the wells would go salty. What few fresh water sources there were would be used up very quickly and they would have to start shipping in water. Very expensive, very troublesome and they decided against it. The same thing might happen in Australia. Your desert would not bloom, it would get worse. [Answer] The first and biggest hurdles you'd have to cross is that you would need to excavate to below sea-level along the whole length of the cuttings... over the desert that's mostly between 300m and 600m deep... you would be removing many thousand cubic kilometres of rock. Reckoning on rock being more than a tonne per cubic metre, you are talking about gigatons per cubic kilometre, petatons of rock to move. That's far beyond current technology. A cutting half a kilometre deep with steep sides won't have much evaporation... whatever direction the wind blew from it would be unlikely to affect the bottom of the canyons you'd be making. So you'd need to make the cuttings slope-sided and many kilometers wide, making the volume of rock to move even bigger. Mind you, the spoil heaps you'd make would create some spectacular 'mountain' ranges and induce significant rain. The global warming induced by burning that much fossil fuel may change the climate to the point that your plans get superseded by changes to the environment anyway. Depends if you are a climate-change believer or climate change denier. Actually, the effect of the dust you'd probably release from the workings on the atmosphere would be pretty drastic. How much dust did Krakatoa throw into the atmosphere? That was only a few cubic kilometres of explosion, you are suggesting thousands of times as much rock moving. If you didn't dig canals to below sea-level you'd need to pump water continuously up-hill for ever. Huge pumps, and you'd end up with the middle of Australia covered in salt-pans within a few years. [Answer] As many people pointed out, the issue isn't a canal, but rather getting the water to condense and fall as rain where and when you want. Just pumping water around on the surface isn't going to do more than raise the average humidity, which will be annoying for people trying to live there, but not actually providing enough moisture for agriculture or urban living. So what you need is something to raise the evaporated moisture high enough into the atmosphere where it will condense out into clouds and rain. Many people have mentioned a mountain range, but building a mountain range is perhaps somewhat outside of the budget for the project. Instead, why not place [Solar Updraft Towers](https://infogalactic.com/info/Solar_updraft_tower) in the paths of the prevailing winds? The towers can be built on the coast, and the vast updrafts created by solar heating of the tower draw moist air in the base and eject it at high altitude, with the tower being up to 1000m tall and the stream of warm, moist air possibly rising even higher. [](https://i.stack.imgur.com/VulNq.png) *Cross section of a Solar Updraft Tower* As the towers are built, the amount of moisture being ejected into the upper atmosphere increases, with the potential for gradually increasing rainfall. The towers are built along the coast, but in the paths of the prevailing winds in order to allow the moist air to travel inland, possibly condensing and raining out in the Australian interior. [](https://i.stack.imgur.com/kSWf8.jpg) *Prevailing winds over Australia* The major advantage of this plan is it can be done modularly, so adjusted to increase or decrease precipitation. The other benefit is there should be salable vegetables and electrical energy, to help the scheme become self financing. [Answer] Steps: 1. Bore a huge tunnel at sea level across the short length of the continent. This would be difficult and expensive but is conceivable. 2. At places, dig down to the tunnel. Note that we have much [deeper pit mines](http://www.mining-technology.com/features/feature-top-ten-deepest-open-pit-mines-world/), so this is also expensive but conceivable. 3. Use mirrors to reflect the sun down into the hole. Build a [seawater greenhouse](https://en.wikipedia.org/wiki/Seawater_greenhouse) at the bottom. This does two things. First, it provides fresh water. Second, it provides food year round. Note that you'll need a bunch of these to have any impact. 4. Build photovoltaics outside to create electricity to pump the fresh water out of the hole. Back up with wind mills and above ground storage (when there is power, pump up fresh water; it can be used normally from storage when there is not power). This plan might not immediately turn the interior desert into one giant oasis, but it provides immediate benefit in terms of placing people inside the desert. You don't have to open up the entire "canal" at once. You can dig the hole first and then connect the hole up to the ocean (or to the next hole) with a tunnel. Over time, you can build enough tunnels to cut through the continent. And over time, you can build more and more holes so that more of the tunnel is open to the sky. The biggest problem that I see with your original proposal is that it basically says to first dig a trench that may be six hundred meters deep and a kilometer wide at the bottom (more at the top). That's an incredibly huge project that offers no benefit until it's finished. This avoids that by digging a tunnel instead. The tunnel can be narrower in the beginning and made wider over time. It allows for incremental changes. Also, the mirrors allow for much steeper sides. One of the largest problems though will be to keep the tunnel open. The channel will likely need to be cleared of silt regularly. Fortunately this doesn't have to be done continuously, so it can be solar/wind powered. That would mean more silt clearers though (the less it runs, the more clearing that needs to be done when it does run). This proposal might eventually lead to your wide trench, but it has benefits far before that. [Answer] There was a [study](http://link.springer.com/article/10.1007/s10584-009-9626-y) out of New York some years ago that looked at using solar power to desalinate seawater along the coast of Australia (and the Sahara). With the water available, forests would be planted, which would take up carbon dioxide and also bring more rain downwind. If done carefully, digging canals would theoretically enable extending the desalination and forestation into the center of the continent. [Answer] CyberFonic is correct. I actually looked at this some years back after some recent Queensland floods. The general pattern is that we have some floods in Queensland and some months later Lake Eyre fills up with water and massive amounts of life seemingly comes out of nowhere - its normally a salt lake. There is a whole collection of rivers that are almost but not quite connected up that lead all the way in from Arnhem Land and the Gulf of Carpentaria into central Australia. When we get a heavy rain they connect up and life returns to the desert. So I was wondering at the time why not run a public works project to redirect some of the annual wet season water that normally flows into the Gulf and direct it South down existing river systems by interconnecting them at the nearest points. If you are bored you can spend an interesting afternoon running your own hypothetical civil engineering project by following all those dry rivers north and working out where you would need to build a cutting to bring wet season water south. Last I looked at it - it was feasible. Not small but not impossible either. <https://www.google.com.au/maps/place/Lake+Eyre+(North)/@-25.523357,139.7315737,776587m/data=!3m1!1e3!4m5!3m4!1s0x6a8588dcbf6a7371:0x2a033654a8627350!8m2!3d-28.1750101!4d137.2923893> Big kudos if you can convince someone to fund it. [Answer] Ever noticed Lake Eyre? The channel country in QLD drains into it during the wet seasons. Then it all flows down south between SA & Vic. When Lake Eyre is full of water it turns into an amazing paradise. The trick would be to get rain to fall more consistently in the channel country. The cattle farmers would be grateful for the consistency as well. [Answer] Rather than the obvious answer "it can't be done", lets remember Trump became president of the U.S. Stranger things have happened... Using A: a height map: <http://www.virtualoceania.net/australia/maps/elevation.gif> B: A rainfall map: <http://www.bom.gov.au/climate/how/newproducts/images/annualmap.jpg> C: A map: (google maps) D: several wind-direction/speed maps A quick glance (and some very basic knowledge of how rainfall works) would indicate that you need both water "and" mountains to hold in that moist air. I.m.o. the most topographically obvious place to dig a canal and end in a lake would be from Denial Bay (approx. -32.095936, 133.647133) up to the middle of the Simpson Desert somewhere right of Birdsville (approx. -26.002004, 137.867470) you could basically keep the mountains to your left and end in the driest area of the desert. Next you would need mountains. I would extend the already existing mountain range from Ikara-Flinders National Park (approx. -30.966680, 138.831585) up to Birdsville (-30.966680, 138.831585), mostly following the Birdsville track. This way you would avoid digging through already existing large bodies of water, and have that water add to the total. This should keep the moist air in. I actually think someone with actual knowledge of the subject matter could do a far better theoretical job than me, so please feel free 1-up me. [Answer] **To create a freshwater lake you need outflow as well as inflow** Rivers dissolve salt as they pass over the land. This ends up in the sea. As a result lakes that do not flow to the sea are salty. Take for example the River Jordan, forming the border between Israel and Jordan. The Jordan flows through the sea of Galilee, which is fresh water, and ends up in the Dead sea. All the salt carried by the river ends up in the Dead Sea, which as a result is as salty as it can possibly be (the excess salt ends up precipitating out as solid.) In general, the salinity of a lake depends on the relationship of outflow to inflow. For example if a lake loses 80% of its inflow by evaporation and only 20% by outflow, it will be 5 times saltier than the rivers that feed it. **Reflooding the Dead Sea** Increased human water use on the River Jordan is causing serious environmental issues at the Dead sea, whose depth is receding at about a metre a year. Separate rojects running over [Jordanian](https://en.wikipedia.org/wiki/Red_Sea%E2%80%93Dead_Sea_Water_Conveyance) and [Israeli](https://en.wikipedia.org/wiki/Mediterranean%E2%80%93Dead_Sea_Canal) territories been proposed reverse this, by bringing water from the sea, as Dead Sea lies below sea level. The former proposal has been elevated to "planned" on Wikipedia so seems the closest to implementation. It involves pumping water uphill from the red sea, which would then flow by gravity to the dead sea, where at least some (possibly all, wikipedia is not clear) of the pumping energy would be recovered by a hydroelectric station. The latter project, from the Mediterranean sea is still listed as "proposed." It is a shorter route over higher ground, so would require the construction of a tunnel, but there would be no pumping station, just a hydroelectric power station at the Dead Sea end. **An Australian proposal: a Lake [Torrens](https://en.wikipedia.org/wiki/Lake_Torrens) - Lake [Eyre](https://en.wikipedia.org/wiki/Lake_Eyre) project** Central Australia has many salt flats, which are essentially lakes that have become completely filled with salt, as they do not flow out to the sea. One of them is the aptly named Lake Disappointment, discovered by explorers who believed that if they followed a river they had found downstream they would eventually reach the sea. Lake Eyre (elevation -15m below sea level) is 300km from the sea at Port Augusta. Much of the distance is along the bed of Lake Torrens (elevation +30m). Both of these "lakes" are rarely filled with water. The Lake Torrens bed was brackish 35000 years ago which is very a very short time on a geological scale. In order to reduce the salinity of the area, a canal could be dug from Lake Torrens allowing it to drain either into the sea or Lake Eyre. However as Lake Torrens is rarely flooded (the last time was 1989) it is only a partial answer. To provide an economic reason, I suggest digging a canal from Port Augusta to Lake Torrens, and a tunnel from Lake Torrens to Lake Eyre. This would comprise a pumping station lifting seawater into Lake Torrens, and a hydroelectric station releasing water into lake Eyre. The canal could be navigable, enabling salt to be mined and exported. Flooding of Lake Eyre might have some effect on rainfall in the area, but only if the installation was massive. Over a period of decades, probably centuries, Lake Eyre would fill with seawater (to be clear, a lake with no outflow will always be salty) but the Lake Torrens basin, draining into Lake Eyre via the tunnel (or perhaps backwashing to the sea via a suitable arrangement) would become less and less salty. Flooding Lake Eyre would lead to an increase in the local water table, which might make retaining some water in the rivers that feed it (via damming etc) more practical. On the downside, the character of both lakes would be changed, and depending on your opinion not necessarily for the better. The proposal of flooding Lake Eyre (and its effect on rainfall )is mentioned briefly in the wikipedia article on the lake but it has thus far been considered impractical. Topography can be reviewed at <http://en-au.topographic-map.com/places/Australia-7358/> [Answer] I think a series of up draft solar towers with double chambers in the canopy so the underneath of the canopy can be utilised as veg. farms using vertical automated system - a enclosed greenhouse style, as well as livestock farms etc, so the nutrients poor soil does not need to be used. Perhaps later on when there is sufficient amount of organic matter generated by human activity eg. farm and human waste, this can be added to the soil which then can be used for growing food. To avoid potential contamination of the water table, an underground canal/tunnel, the size of a medium sized river could be dug. Underground, so it can stay at sea level ( resp. below ) to avoid using pumps and also to prevent evaporation, resp. utilise evaporation inside the tunnel to capture drinking water. This would be required to be periodically cleaned of sediments utilising automation,the sediments could be used in building industry etc. The towers would be connected with this underground ocean salty "river" . They would generate power for farming as well as cooling the giant greenhouse. The towers would also act as a desalination plants. The process has been explained above. There would be minimal effect on the outside environment as this would be fully enclosed system, eventually becoming self sufficient and sustainable using organic waste to produce food and number of other products. Each of this towers would become a small city bringing employment. This idea would not make the arid deserts of Australia green, or at least not for some decades, but it would utilise land that is wasted. [Answer] Australia could build a canal and store monsoon flood waters in underground reservoirs. They really do not have to build desalination plants near their cities when tens of billions of cubic meters of water are washed out to sea. They claim the distances are too great and the costs a burden but Australia is thinly settled and most of the country is still not developed. The northern states or provinces retain water rights and they do not want to share their water resources with the south since water is primarily used for agriculture for profit not really for metropolitan settlements or vast water starved areas of the country. And this is the key to the water dilemna in Australia. If water was provided for settled areas it would increase the population by increasing immigration for feeding a larger populated country. More people would decrease the GDP per person (ie. lower standard of living) because there are finite resources such as water. [Answer] The arid areas of Australia are among the oldest and untouched. The ecosystems are extremely complex. Just because much of it is extremely dry (entisols), doesn't mean that it isn't fertile. The fact that Australia is so ancient is one reason it would be best left alone and untouched. The soil on the surface of Australia is similar in age to the soils at the bottom of the Grand Canyon, just as Australia's mountains existed before the tallest of mountains in the Himalayas began to even form. [Answer] In the northwest of NSW there is a large irrigation area, where a river, the Murrumbidgee, has water diverted primarily to grow rice. This was instigated back in the 1950's and has been successful for decades. BUT, what has occurred is that by flooding thousands of acres of previously arid country the natural water table has been lifted and this has forced all of the underlying salts to the surface. With natural rainfall from above, when the land become wet vegetation would grow, but because the salt has been driven up with the rising water table nothing can grow in the salt prone areas. So although the irrigation does have a short term benefit, the long term destruction is massive. As others have mentioned, Australia is a very, very old land mass and nature has been working on the land much longer than man has been walking its surface. For man to now come along and 'improve' on what nature has designed is madness. Sure there may well be some short term benefits but in the long run nature will always win. Man is still trying to combat the salt problem within the region but the reality is that it is and always will be a losing battle. [Answer] An interesting read for you would be to research the Aral Sea disaster and attempts to mitigate, as well as the Salton Sea creation/dissolution. No easy solutions (no pun intended). [Answer] Looks like a two pronged approach to the problem is what is needed here: mountains and water. Below is what Australia looked like in 1827, before the British came along and filled in the Great River, undoubtedly with all the rock and soil from the ten mountain ranges that once spread through Western Australia. Therefore, **MegaGeoCorp** propose the following Plan: 1. Use all our high tech radar gadgetry to relocate the course of the Great River, the Inland Sea and all the tributary rivers that flowed through Eastern Australia. We shall also survey Western Australia, sweeping away all the sand until we uncover the foundations of the Ten Ranges. We estimate that the geological surveys should take no longer than fifty years. (It's a big continent!) 2. Phase I of the Reconstruction Project will involve building a number of extra-broad gauge (10ft / 3m) temporary railways the MegaTrains of which will be used to transport rock and soil back to the mountains. Railway construction should take approximately 50 years to complete. 3. Phase II will begin once the MegaTrain lines to Range No. 1 are complete. A dredging programme wherein we shall utilise our patented MegaDiggers will commence, wherein we shall simply dig up all the dirt and rubble the Brits threw into the Great River. Once piled into the MegaTrain waggons, MegaDiggers and MegaConveyors will be used to build up the ancient mountains again! Estimates for Phase Ii range between 20 and fifty years per range. Therefore, by mid-milennium, the original Western Australian Mountains shall have been restored and the Great River and Inland Sea shall have been properly dredged. 4. Phase III will involve uncovering and reactivating the ancient water sources of the Eastern Australian Mountains that the British so thoughtfully destroyed. 5. Phase IV will involve allowing the water to flow from Eastern Australia to Western Australia; while simultaneously breaking the remaining earth dam at the western end of the Great River. MegaGeoCorp planetary engineers have determined that within ten years, all the waterways should be functioning as they once did. 6. Phase V will mark the transition from Terraforming to Ecoforming: as the actual courses of the rivers and the shape of the sea settle down, MegaGeoCorp's part in the future history of Australia will wind down. It will fall to future Australians to make appropriate plans for land use and installation of future infrastructure, settlements, farms and so forth. [](https://i.stack.imgur.com/zVHC2.jpg) [Answer] I read an article where it was stated that all the Queensland rivers( west of Cape York) including flood water dumps about 60 million acre ft. of water a year in the Gulf of Carpentaria. There is a large coastal shelf with shallow waters off on the Queensland Carpentaria gulf side. If there was a dike separating gulf sea water and fresh water from the discharging fresh water rivers a large fresh water lake could be created and the waters could be transferred inland to central Australia by canal. It would help make inland Australia more green and it might change the climate of inland Australia. ]

[Question] [ I'm a supervillain. I have no name, but you can rest assured my intentions are dubious and always result in general harm. My biggest problem these days are these pesky superheroes keep finding my lairs and destroying them. Now I may be rich, but these places are expensive, and I hate having to constantly move. After relentlessly spying on my enemies, I've finally found it. They're finding me using satellite imaging by following me from my last location. The struggle of being a danger to the government in 21st century Earth I guess... I've found a new place to build the perfect Mt. Doom, but being the best place I've ever seen for a lair, I still have my little issue. My island is in the middle of the Pacific Ocean, and is a 3 mile circle of island and beach with a dormant volcano on the northern side of it. I have no budget constraints for this, and my lair needs to be at least a mile in diameter, with the requirement of housing minions and equipment for future bids for world domination. Building underground isn't an option, for personal (*cough plot cough*) reasons, but otherwise I'm pretty open. So with all that said; **How can I hide my entire island from the prying eyes of satellite surveillance?** Bonus points if you can help me hide visually to those on patrol as well! I have no idea what to tag this either... [Answer] # Announce that you are building a resort. Put up a website. Make it look nice. Don't take reservations. [](https://i.stack.imgur.com/WkanJ.jpg) # Make people think its real Hire some (doltish but good looking) [celebrities](https://www.google.com/search?q=celebrities%20san%20tropez&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi6rtiuhrPTAhXGdSYKHfp0AM8Q_AUICCgB&biw=1280&bih=845) to come vacation there. This is actually common behavior for resorts. Tell the celebrities you cleared out the place so they can enjoy it in peace, by themselves. Keep the celebrities away from the buildings that glow at night. Make sure some of your minions can mix drinks. Sell the pictures to People magazine (side income!). If it looks like a resort in a supermarket checkout aisle, then everyone will think it is a resort. # Store doomsday device in outbuildings [](https://i.stack.imgur.com/ARoi8.jpg) There's lots of buildings in the resort. But its so exclusive and private no one knows who is in all those other buildings. This is where the sharks with lasers attached to their heads get stored. # Let the minions hit the beach As long as no celebrities are there, let the minions hit the beach once in a while. Hire attractive minions. This seems like a good super villain plan, anyways. The general activity of people walking around will make the resort look more legit, and increased minion morale will help when you have to feed some to the laser-sharks. [Answer] ### Plain sight If your lair must be above ground, then the problem is that you need to stop trying to hide it. Build the lair in plain sight as part of a larger complex so when they look at the satellite images they see what they expect. Sure, if you build a lair on a deserted island, they'll notice immediately. So make the island not deserted. Build a factory, resort, or theme park on top of it. It doesn't really matter which, except as a justification for whatever you put in the lair. Of course, now you have the problem of people wandering all over your secret lair, which may lead to its own problems. It sounds like you have an affection for a certain kind of lair. Have you considered that having one lair with all your minions may be part of the problem? Get your own lair and order your minions around remotely. They can have multiple lairs. Lose one and you still have the rest. And moving inconveniences the minions, not you. You can live in your mansion under a false name as a reclusive billionaire (or whatever). You could even sponsor some anti-criminal activity and leave hints that you are a hero so that the real heroes leave you alone. Meanwhile, your minions run out of their smaller, less expensive lairs. This will also save you a bunch on travel costs. Your minions can stay much closer to their crimes. When they make an especially big score, close up shop and move their lair. [Answer] The problem of a lair on an island is, unless the island is Britain-sized, you're going to sent all the materials there for the building. Even if you had an island-sized invisibility cloak, Harry Potter's style, and cover your island with it, you would still be found just by tracking all that maritime traffic going there. My suggestion: **Mobile island** Since you only need a 3 mile wide island and you don't want a subterranean lair, just build it up from floating containers and vessels, and move it around all the time on a random pattern. Satellites only pass over a location several times a day, and photographs are analyzed some time after. By the time they have seen you, you're not there anymore. [Answer] Not going underground or into the mountain makes it harder. Not impossible but it will make one thing pretty hard, heat management. That will likely be your biggest issue. You need to appear as a normal thermal footprint on those satellite images. For regular imaging it's not that hard, use camouflage. To use a famous example, try what the [Abraham Crijnssen](https://en.wikipedia.org/wiki/HNLMS_Abraham_Crijnssen_(1936)) did in World War 2. After being caught behind Japanese lines they painted the deck roughly like rocks and covered the entire ship in jungle foliage. They only moved at night and then anchor during the day. They hid among the other small islands in the Pacific. For your secret base the same applies. From above you need to appear like any regular uninhabited Island. This is again where the no underground gets difficult. Mostly it means you have very limited build space. You can build under the canopy of your trees. Beyond that there is little space as you don't want to cover the roof with dirt. Or is a thin layer okay? Then make your roofs like dirt and small plants, maybe sand. Perhaps [Iwo Jima](https://en.wikipedia.org/wiki/Iwo_Jima), again in World War 2 might offer some inspiration. The Japanese dug in on the Island anticipating a US invasion. Besides [an extensive cave and tunnel network](http://www.battle-fleet.com/pw/his/Battle-Iwo-Jima-Defense.htm) they had hidden bunkers all over the Island. So staying hidden is possible if you accept limited space. Depending on your canopy coverage you can get your one mile diameter or you need to break that into smaller parts scattered around the Island. Still your biggest issue technology wise would be temperature. You need to limit this. An active volcano might offer some relief here. You need to go underground for it to work but you could hide some heat production in the volcano itself. Maybe even use the geothermal energy itself. The rest of the base though, no heat. Your base will be primitive, limited electricity, electronics as well. I hope your minions like reading in their spare time. [Answer] Instead of trying to hide your base, open up a Private Military Contractor, get some contracts and call the island a training camp/operations center. Any military equipment you bring there can be written off as part of your company's stockpile, and as long as you are actually working for the various western intelligence agencies they will probably turn a blind eye to what you are actually doing with the island. As a plus, this will naturally make you friends in the intelligence world, who you may be able to leverage if some nosy superhero is making plans to investigate your base. [Answer] **That's probably near impossible** in our modern society. Nowadays, [archeologists](http://www.npr.org/sections/alltechconsidered/2016/02/17/467104127/space-archaeologist-wants-your-help-to-find-ancient-sites) use satellite imaging (in particular Google Earth) to find ancient site. That's a humongous task, but with the help of volunteers and crowdsourcing, they made a lot of discoveries in the recent years. Not only they have access to traditional images, but also datas from all the light spectrum (infrared,...). Citizens will be more than happy to give a hand to Captain Canada by finding the lair of his ennemy. One option: own the companies that provide the satellite images to the public and erase your secret palace from the images. Of course, that will be a pain in your devilish ass since that billionaire playboy Bruce Spark that fight you as Steel Man will probably have his own satellite imaging company. Also, the images shared by Google in our world comes from government, in particular the American government. So, you could decide to bribe a high-rank member of the government to force the company to hide your location at the source. This has some limit since, as a genius, Bruce Spark may have his own network of satellites. Finally, you will need to communicate with the outside world to prepare your evil schemes, and communications can be easily intercepted by this shadow organization S.H.E.L.T.E.R, and tracked back to your location. As a conclusion, in our modern world, no place can be hidden forever from someone that has technology, time and will. Why do you think that dictators and criminal lords constantly move and use doppelgangers? [Answer] So with a limitless budget we’re asked to design a way to hide the island. All right. Let’s start simple. You could build colour, and design the buildings on the island to look like local geologic formations, boulders, sand dunes, etc. You could also cover the buildings in plants, grass mosses, etc. They would not be underground, simply made to look like it. We then have the issue of heat signatures. I can’t personally think of anything that would counteract this, besides perhaps building your base under the ocean nearby to the island, but that probably doesn’t fit your requirements. Nonetheless an idea for the evil genius at a later date. One could also presume, since the budget is limitless, that you could just have spies or hackers who either work for the people after you, or go into their systems and change the images. Erasing them would probably get you noticed, but eh. [Answer] You could use the heat from the volcanic activity on the island to evaporate ocean water to permanantly obscure the island with steam. You could also use some sort of weather manipulation like cloud seeding to create a dense layer of clouds over your island. [Answer] Visually it would be fairly doable if you had the money to build. Just have a huge two story complex, bottom story is your lair, top story is a sprawling tropical island resort. There are no openings between the two that can be found, and all openings of the lair to the outside World are concealed perhaps only accessible by sub. Perfect for bringing in and out your minions with normal tourists. One entrance to the lair could be built directly under the small airfield even. Island resorts have transient populations and a lot of activity that can be controlled and areas are easyish to block off. [Answer] If you don't have money costraints just start your own space program, launch your own satellites to hack other satellites (because physical access is instant pwning) in orbit to not show your island. Nobody will ever question if satellite imagery is legit. Money is the best superpower. [Answer] Announce to the world that work is beginning on a new Lord of the Rings movie. Your evil fortress of evil -- so far as the world knows -- is the movie set of Morgoth's house. As epic movies take quite some time to film, you'll have several years before anyone becomes suspicious. Once the trade rags start wondering what's going on, cancel the movie. Revamp the facade, and now your Evil Lair is the movie set for the Assassin's Fortress in the new Assassin's Creed movie. You should be able to keep this up indefinitely, with the added bonus of a cool new look every few years. Heck, you might even end up producing an actual movie or two! [Answer] Permanent fog! Just turn on the volcano (or fake it) so it keeps the island (all or the part you want to hide) under a permanent fog. This will attract scientists, but you jail then and force then to work for you ... until someone reports to a superhero that his friend is missing and he will investigate in the last known place :) [Answer] Make a dome of flat-panel monitors, over and around your base, and project the islands former natural glory upon it. Or a dome of mirrors (or fiberoptics), angled at the deeps of the jungle, for the same effect, without giving away heat. [Answer] Step 1: Building a complex. Factories to manufacture goods without taxes. Housing. Stores. All connected by walkways. All with tungsten-titanium shells. And really good AC units. Step 2: Cause a controlled volcano eruption. Keep the heat down enough that you don't melt the buildings. Make sure it looks cataclysmic. But also make sure all of the buildings are all buried under tons of rock and ash. Step 3: Cash in your insurance policy. Step 4: Start using your 'destroyed by a volcano' base. ]

[Question] [ To My Trusted Advisors; It has now been six months since the founding of Puzzleville around the entrance to the magic-filled Labyrinth of Wonders. As expected, adventurers from around the world have braved the subterranean depths to extract the countless artifacts left behind by the maze's builder, the elven mage Parasaxor. The city's population and wealth have exploded these past months. Unfortunately, so too has the number of magic items increased dramatically. There have been complaints from the adventurers that a majority of the items they find are insufficient to their needs or inferior to their existing equipment. As a result, they often pawn the goods to the merchants of Puzzleville. Four times now, merchants benefiting from this influx of powerful magic have become delirious with power, using the wonders of the Labyrinth against their fellow citizens and to exact retribution for past slights or force payment of old debts. This is, of course, upsetting to hear. However, it has caused some adventurers to take their business to merchants in other locales, where the influx is starting to have a similar effect. The king has been made aware of this growing problem and has charged me with presenting a solution within the next few days. As you are well aware, His Majesty has concerns regarding the use of magic, especially after the pie incident at the recent Thanks Festival. **As such, I am asking each of you to formulate a mundane solution to the problem I have outlined above.** Please have your plan on my desk as soon as possible. The solution that imposes the least impact on the merchants and the Merchant Guild while safeguarding the royal coffers and all levels of the economy will be implemented. *Ebyssybl Mollassand* First Treasurer to the King P.S.: Remember that the roads are unsafe in our Medieval world. Stay safe while traveling for this year's hibernal solstice celebrations. --- On Adventurers Adventurers are treated in the region as a necessity. They help keep the growing monster population in check and deal with mages that become crazed and/or delusional, some of whom even build elaborate subterranean vaults filled with magical artifacts. Adventurers typically don't receive support from the government; they make their livelihood purely through adventuring, though they may receive a commission for undertaking certain tasks on behalf of the government or an individual. As a result, the common folk are happy, but cautious, about the average adventurer. On Others This question is only concerned with merchants, not the issues of thieves that necessarily arise parallel to the merchant issue. Also, note that this is not an issue with all merchants, but only the ones that are particularly aggrieved/vengeful/etc. Finally, while mages are available, this question is specifically focused on defining a non-magical solution. [Answer] Dear Ebyssybl Mollassand, So, if adventures tend to only sell items that don't make them better adventurers, that means, no matter how powerful someone becomes with sold magic items, there will always be an adventurer (or group of) strong enough to take them down. This seems like a situation that the Adventurers Guild and Merchants Guild could solve on their own. If a merchant starts getting out of line, their guild will revoke their membership, and send a notification to the adventurers guild. The adventurers guild than sends someone (or a party) to track down, stop, and hand over the rogue merchant to the proper authorities. (We could even allow them to be paid with the magic items the merchant was misusing) From there, The law would be applied as normal. (Was anyone hurt? Murdered? Harassed? Robbed? Number of Victims?) In the event that the Adventurers and Merchants guilds don't exist, I'd recommend instituting them. They are a great way of keeping track of who's in the profession, who's reputable in the area, a steady source of work for its members, makes it easy to set up connections/contracts with people of different lines of work, and makes polices on merchants and adventurers more enforceable (as the benefits of being a member are typically too valuable to just brake their rules whenever). Your Trusted Adviser, Tezra Raine Sekoi P.S. Now that I think about it, since magic items typically are mostly useful to adventurers, most combat magic items should, one way or another, find there way to the adventurers guild (since adventurers would be the primary consumers, and that's where they gather). So the adventurer guilds should be the ones 'buying' magic items from adventures (more convenient for both of them) and for magic items more suited to the common folk, the adventurers guild can work a deal with merchant guild for selling/supplying magic items to shops. Maybe even keep the magic items held by the adventurers guild for safe keeping until purchased. I feel I should also note that improving enforcement of the law not only deals with the current problem, but also other problems related to illegally distributed/misused magic items. Otherwise, you are usually just trading one problem for another. (Remember to consider the black market's effect, civilian happiness (or else revolt), and how easily an unlawful man can bypass the kings new policies) P.P.S. It has come to my attention that there has been a fair amount of talk about putting regulations on adventurers, and even some whispers about waging war to eliminate one of our most prized resources (adventurers). So I decided I should weigh in on these options. Starting with the most drastic, culling the adventurers in our kingdom would incur heavy losses on both sides. Even if we win, our loss of adventurers and military strength will be seen by our enemies as a sign of weakness. And without the aid of our adventurers, I fear we will not last a fortnight. As for directly regulating adventuring activity, I fear we lack the resources to do this. If adventurers can't offload their goods legitimately, they will end up selling to the black market, helping these magic items fall into the hands of people more willing and able to misuse them. And setting up guards not only will ENCOURAGE adventurers to enter (as they will believe the loot will be better), but our guards would not last long against an ambush of adventurers. There also seems to be rumors that these magic items are corrupting the minds of those who handle them. Looking over the reports you gave, it seems more like the majority of these cases are people, who are emotionally distressed and have access to lots of magic items, are misusing them in an attempt to, as they believe, 'put their life back together'. We should not be treating these cases as bad people doing bad things. Good people do bad things when they feel they have no other options. We should instead be viewing this as a cry for help. Obviously, injustice should never be just forgiven. These merchants should make amends for the damage they have done. Unfortunately, These distressed citizens won't just come to us and tell us there is a problem. Normally, this is a matter I feel best left to the Merchants Guilds to address themselves, and we should only help as much as they ask for. However, I do have a few suggestions on how we might alleviate some of this burden ourselves. 1) Start an outreach program. Let the people know that we are here to help them. Encourage people who are feeling distressed to come to our local agents to talk about their hardships, and receive free counseling to help them feel better and make things in their life again. We could even come up with a name for these agents who handle the more 'psychotic' citizens... something like "psychiatrist" should work! 2) Drop taxes on magic item sales. With the economic boom these magic items bring, making them easier to sell at a profit will make merchants feel these goods are better used as sellable goods than personal tools of retribution. The lost taxes on magic items should be supplemented by the increased trade of other goods like iron and silk (thanks to the overall increase in trading). [Answer] To the honoured Ebyssybl Mollassand, Unfortunately my agency will be unable to assist until you are willing to take a holistic solution to this problem. Your continued insistence on using freelance agents to address a problem that should be handled by permanently retained specialist military units has led to a large accumulation of unsavoury elements within your kingdom. These merchants, whose behaviour would be considered criminal by any other standards, are tolerated because they are willing to do business with the "adventurers" upon whom you depend for internal security. Should your kingdom be attacked by an external power these adventurers, who it must be said have have no loyalty to the kingdom or indeed to anyone but themselves, could well end up fighting as mercenaries for our enemies. These freelance adventurers should be absorbed into your standing army and directed to the regions where they can do the most good rather than where they can gain the most profit. It is essential that the security of the nation is not put at risk any further. A healthy pay and pension scheme, along with bonuses and rewards for securing strategically critical areas and recovering valuable equipment, out of which they should certainly be able to take their pick, would easily outweigh the short term benefits and risks of the solo adventure. Your faithful servant, Separatrix Security Consultant Guild of Anachronistic Trade Specialists --- --- [Answer] # Dutch Disease It is a clear case of the **[Dutch disease](https://en.wikipedia.org/wiki/Dutch_disease)**, where an influx of gold/oil/cloaks of charisma +2/butterknifes +5/whatever ravages the local economy, with the adventurers briging out so much gold that a back massage now costs 10 gold pieces (a yearly salary before), with self-healing swords and self-sharpening plows putting blacksmiths out of the trade, horns of abundance driving down the price of cheese and grapes to below producer costs, guardian golems replacing paid guards and so forth. For a medieval economy **without a proper workforce retraining program**, the effects can be catastrophic. The king's astrologer-economists would normally suggest "sterilizing" the inflow of magical goods by forcing a "magical quarantine" period, supposedly to prevent cursed items from entering circulation, but really to slow down the flow of magical goods enough to protect the economy. However, the flow of adventurers and items is such that keeping control of the flow of magical items once they're out of the dungeon is out of the question. To cries of "(Dungeon-)crawl, baby, crawl", former shoe-shiners and barbers are now taking up adventuring. This has the clear hallmarks of a magical bubble. # Treasure interest rate hike required More **drastic measures are required.** Thankfully, the King's consort is a (thrice removed) blood relative of the great black dragon Nizidramanii'yt, who has (secretly, obviously) agreed to help safeguard the Parasaxor trove for a modest monthly contribution of maidens. Great spells of dissillusionment will hide the entrances and strong magic will redirect the adventurers to lesser dungeons where Nizi will plant medium-level monsters and properly vetted magical items. The few high-level parties that can make it past the dragon's illusions will either be destroyed (if the dragon judges that it is safe to do so) or a negotiated settlement and treasure disposition agreement will be signed between the parties. [Answer] Expanding upon what Tezra said: In a society with a flourishing adventurer class the adventurers are generally the most powerful agents around. There might be some wizards in their towers that are more powerful but they aren't really combatants and have little chance of taking down a balanced group of adventurers. Multiple answers have suggested banning them--but how? Remember, they're the most powerful agents around and likely have access to magic that will defeat your security attempts even if they don't simply march through your guards. Rather, we need to look to them for the answer to the problem. How do you control an adventurer who has lots of power and little if any loyalty to the government? Wanted posters. If someone, adventurer or not, gets out of line the government puts up a wanted poster. They make no efforts to bring them to justice, they just let everyone know that it's acceptable to bring them to justice, or to kill them if they won't surrender. The traditional payment for adventurers is their loot--it need not cost the king a copper piece to do this. Sure, if the adventurers were to get together they could take over the realm without difficulty. They're too much free spirits for this to happen, though. Adventurers are no more herdable than cats. Since adventurers do not want to have to always be watching their back they're going to behave. After a merchant or two goes up on the wanted posters and finds that good gear is no match for better gear plus great skill the rest of them will also behave. [Answer] I see two possible solutions to this dilemma, each with its pros and cons: 1. The merchants need to have a wizard to act as a magical item essayer on call to evaluate items that are brought in. This essayer will evaluate the potency of any magical item, and advise on any primary and secondary effects that the item has, as well as provide warding services to keep magic from items from leaking out and combining with nearby objects, building up to dangerous levels. It takes a real wizard to know that this sword has a +10 thaumaturgic field that needs a class 4 ward combined with Fane's circle of demon imprisonment to keep it from leaking toxic levels of magic all over the place. Any merchant found dealing under the table with unessayed items would be fined and possibly jailed. The cons are that the essayer would have a fee, and so that is a small amount of overhead that the merchant may not like to pay, meaning that fee would be passed on to the customer. **EDIT:** An additional pro is that the essayer would be able to tell the merchant the items true worth, so that a hidden gem doesn't get sold way under value. If an adventurer brings in Grimthane's Helm of Eternal Sight, thinking it's worthless because they don't know the incantation to unlock the power. Or The -3 Boots of Horrible Blisters. The essayer can work with the merchant to make sure that it is bought and sold at the correct price, which would make up for any fee. 2. The sale of magical items could be nationalized. This option is more of a "stick" in case the merchants guild doesn't like the first option. The logic is this: the merchants guild is responsible for enforcing order among the merchants. If they are unable to keep the merchants in line, then it becomes necessary for the government to step in and maintain peace. Since the influx of magic is the cause, then the government will have to take over as the wholesaler of all magical items, and all adventurers would have to sell to the government, who would ensure the safety of the items, and then allow licensed merchants to purchase some of the more harmless ones at a wholesale price. The merchant guild will not like this, and it will open the door to a black market in magical items, and it will be an added drain on the budget to maintain, so option 1 is preferable. **Edit:** 3. **A hybrid approach:** Just make a law that upon exiting the maze that all items must be essayed and cataloged for a small fee, which would give the adventurer a notarized report of the precise properties of the treasure that they found. And then make it illegal to buy or sell any item that does not include this report. This way the Adventurer has the knowledge that they are getting the best price, and the merchant is getting information on the safe care and handling of the items being purchased. [Answer] As heirophant, I recommend prayer. Pray to the gods to take away the dungeon. To sate the greed of adventurers. To cleanse the hearts of the merchants. To bring peace to the world. Now, this being a pantheonistic environment, Your Majesty will need to focus on a specific set of gods (see Appendix A). Large donations to the temples will encourage the clergy to join their prayers to yours. Divine Will overcomes the strongest magics. And the best part of this strategy? If it does not work, it is not your fault, Majesty. It is the will of the gods, and you may rest easy knowing the economic disruption is approved by Heaven itself. Yours, The Hierophant [Answer] From: Tammat, Guardian of the King's Forests, North Puzzleville region. To: Lord First Treasurer, Ebyssybl Molassand-sama. Lord First Treasurer, Had it not been a direct order and had my life not been already forfeit, I wouldn't presume it upon me in my low rank, to even address thou, Lord First Treasurer, much less offer suggestions. Forgive me for my transgressions, as a former military man I have no way with words. I'll be therefore unacceptably blunt. Lord First Treasurer! **I urge you to act immediately, lest the problem of occasional merchant villains will be an organized Guild of villains**. Merchants are no strangers to alliances and already alliances are being formed. Most dreadful are ones made between those, who have been driven to insanity in their new-found power. All my sources agree to the fact, that Merchant Guild as we know it will soon cease to exist. Instead, something else will emerge. Our actions - and the decision of His Majesty, may he live forever - will shape that new organization. In the best scenario, it will be current Merchant Guild, albeit much weaker and with little ability to deal with this internally. Worst scenario means current leadership, appalled by practices of insane merchants, will be replaced by them entirely. Means to that end are various: it may be puppetry, hypnosis, old-fashioned and perhaps even mundane blackmail, forceful control... There are as many means as there are magical artefacts and then some. Therefore, Lord First Treasurer, please hasten the matters or Puzzleville may soon be our country's territory in name only. You need to know Molassand-sama that it's not certain what amount of magical artefacts (and of what power) drives the man insane. Furthermore, we cannot truly tell if the insanity begins due to sheer power they are able to wield eroding their wills or if there's dark magic afoot. We cannot therefore exclude nor can we confirm: * some merchants being weak-willed, or greedy enough to misuse the artefacts they acquire (despite adventurers possessing more powerful magical equipment, there's little to no such occurrences among them) * only certain merchants being susceptible, * any amount or power of artefacts being "safe", * number or power of artefacts that triggers the insanity, * any special handling of magic equipment that makes adventurers immune or resistant to it, as opposed to merchants * foreign power ploy: e.g. 'tainting' some artefacts to cause lust for power, bribing some adventurers to sell dangerous or 'tainted' items to certain merchants * existence of a merchant resistant or immune to magical artefacts 'siren call' I woe my inadequacies in providing these answers. I've made best efforts in tracking and collecting necessary facts, however I plead with you, Molassand-sama, to find someone more capable than myself and entrust that person with this task. Researching these merchants made them aware of my existence and they deemed it displeasing. There have been three attempts on my life and I'm certain there'll be one that succeeds as I have less and less means and my disposal to avoid them while I continue my duties. Knowing my time is running out, I've compiled all I know, copied it and dispatched five of my best rangers, in hopes at least one will reach you. Roads are not just unsafe, they are outright controlled Lord First Treasurer. Two patrols have gone missing. Six men led by Seargant Hamare tried to reclaim a bride captured on her wedding day and met their deaths at the hands of a masked villain wielding Cane of Illusions. Said Cane was traced by one of my agents to hands of one Illustrio Ropatis, merchant of mediocre standing and dubious loyalty. Not a single soul however, including the groom, was willing to even admit he was the abductor. More worrisome however is another patrol. Noticeably weaker, consisting of only two men and not of the army, but of local militia. Lord First Treasurer, this patrol was LURED and killed. The way it's been done suggests a preliminary test. I can only think that this was done with premeditation, to know how powerful the item was. However choosing local militia for that particular test instead of some monster suggests next targets are most likely from the local garrison. Finally, it is my duty to inform you, that at least seven adventuring parties currently located in Puzzleville hail from other nations that our own. Therefore it's only a matter of time when current situation becomes known to foreign powers, if it's not already. Lord First Treasurer, now you know the seriousness of our situation. I propose the following: * **counterattack** * **intercept further magical items temporarily** * **find out the cause for merchant's insanity and introduce countermeasures** ## Counter-attack Is necessary Lord First Treasurer. Without it, the nation will be perceived as weak and King's agents already are simple targets. Also, immediate counter-attack shifts their focus and disrupts their plans. This is the only way to save current leadership of the Merchant Guild. Please: * announce a mission to curb down merchants driven to insanity * have all royal and affiliated adventurers undertake that mission * put up wanted posters for several merchants about whose misdeeds we have certainty (my rangers carry that list as well) * seize all their belongings (and make most of it Crown's property) * mobilize the army to seize and punish as many wrongdoers as possible, or at least to increase our presence in the region and make it harder to strike at King's men ## Intercept Please be aware that mishandling that point will cause unrest among both merchants (insane or no) AND adventurers. I can guarantee the cooperation of current leadership of the Merchant Guild (for how long, I cannot tell, I'm not privy to plans for coup d'etat). There are several solutions present: 1. Announcing that since some magical items found in Parasaxor's labirynth are very likely causes of insanity, all items must be verified, therefore temporarily they'll be confiscated and studied, before being returned 2. Using the royal adventurers to seize the belongings of several high-profile insane merchants and using their funds to fund the compensation for other items. 3. Offering obligations to adventurers for selling the items directly to our kingdom, obligations could be exchanged for cheaper inns or equipment repairs. 4. Buying items directly from adventurers. 5. Forcefully seizing all magical items from certain merchants, who cannot tell where the items involved in certain incidents are (like Cane of Illusions, or some middle-grade items capable of flame/explosion magic like the one that obliterated militia patrol). None of these work long-term, my more economically-inclined friends tell me so. Nor will banning the trade. However all those temporary and inadequate stop-gaps may give us time for finding the true solution. ## Stop the cause Please, assign a more suitable than myself person to investigate the cause for merchant's insanity. **Only by addressing the true cause shall we prevail.** Apologies for burdening you with my incompetence Molassand-sama. I'm fully aware that above solutions are inadequate. I see the reason for that in the fact I am unaware of what is truly causing the issue. Therefore, I can only ask, please make that utmost priority for someone who is well-versed in magical items and human minds alike, for it is between these two where this crisis was birthed. Tammat, Forest Guardian, PS. Regarding the choice of my successor, I'd like to nominate all the rangers to reach you, Molassand-sama, among the five I've sent. I'd personally select the one that reaches you with least amount of trouble and without being detected by the enemy, both foreign and domestic. Apologies for burdening you with such a trivial matter which should be handled by myself. [Answer] Sir *Ebyssybl Mollassand*, Everything that is magic shall be deemed heretic. As soon as you give us, Inquisitors, immunity from common laws, be assured that we will address that problem. * Father Gregory IX, head of the eastern Inquisition division [Answer] To First Treasurer *Ebyssybl Mollassand* Your Honor, I would summarize the issue you describe as: adventurers are selling their unneeded magic weapons to untrustworthy people who abuse them. Describing these purchasers as “merchants” is perhaps not entirely accurate. As your letter reports, the problem arises precisely when a buyer does *not* resell the item at a profit. I would humbly suggest that it makes no difference whatsoever whether the person terrorizing His Majesty’s subjects found the item, purchased it from an adventurer directly, or purchased it second-or-third-hand. The difference between one of these “villains” and an “adventurer” might be more difficult to draw than one would assume. In other words, I advise Your Honor to focus on what people do, not who they are. The problem, simply put, is with the unrestricted sale and use of magic items. If the realm can focus on illegal use of magic, punishing and deterring it effectively, that could suffice. His Majesty's government might additionally wish to require purchasers to report all such purchases and sales; in addition to making crimes easier to solve, it would be very useful to know just what people are finding and how that is changing over time. Failing that, the Crown could attempt to set up a monopoly on the purchase and sale of potentially dangerous items, if it is prepared to crack down on the black market that inevitably would spring up. This could guarantee that items too dangerous for use would be identified and locked away safely in the Royal vaults. In addition to regulating sellers, the Crown could regulate buyers, such as by holding merchants partly responsible for selling the item used in a crime, or requiring the adventurers purchasing their magic items provide proof of their good character and responsible conduct. It might be wise to recruit the next cohort of adventurers from youths from good families who have trained as squires or apprentices, or even to require a commission as agents of the Crown. —Your faithful servant. [Answer] You may not actually have a problem at all. Four incidents of criminality in a whole city doesn't sound like much, has the total level of criminal intimidation risen at all, or are you just seeing a change in the means? You only have a problem if the abundance of magical items has: * Led to more crime. * Made crime harder to prevent or detect. If either of these is true then you have what is known in the universe next door (sometimes called "The Real World") as a negative externality. That is, a cost to providing a service that is not directly born by the consumer or provider. The answer is mundane. You tax the sale of magical items. This is known (in the universe next door) as a [Pigovian tax](https://en.wikipedia.org/wiki/Pigovian_tax). The tax will either cover the social cost of the trade in magical items, or discourage the sale of magical items - or both. You have mentioned the social benefit of heroes who trade in magical items incidentally keeping the monster population down. This is know (next door) as a **positive** externality. With less money being made for heroes from the sale of magical items you need to ensure this positive effect continues, I recommend use of a Pigovian subsidy - possibly on the production of goods derived from monster furs, teeth, ivory etc. Toodles, GtO Chief Economist to Whoever will Bloody Listen. [Answer] Offer to buy the adventurers' old equipment at a much higher price than any merchant could afford. Then create a high tax on the buying of magical artifacts by private citizens. Done right this could bring the entire market for magical artifacts under your control. [Answer] # Invest in adventuring parties Deal is simple: party is supplied with resources they need and transported to the entrance. After they exit, the Treasury has exclusive right to buy any items adventurers want to sell for a price a little higher thab they'd get from local merchants. This can be bootstrapped with gold only. Next, come Treasury-owned adventuring parties - adventurers are supplied with magic items by the Treasury, but Treasury owns anything they get from Labyrinth. Adventurers themselves are sufficiently compensated, but not in magical items. This theoretically allows to get stuff that is **not** inferior to adventurers' gear. If merchants wanted to become villains and could afford that, they'd become villains long ago. Hence, we should assume that they either didn't want or could not afford. The second option is simple: they were paying adventurers way less than those items actually cost. This seems plausible and allows the Treasury to buy those items cheaper than they actually cost *while still paying a tad higher than local merchants*. There are 2 ways how things may play out next. If the Labyrinth has low enough quantity of items, they will all simply go to Crown's disposal by pretty cheap prices. That's a win. If the Labyrinth has high enough quantity of items to change their market value then the whole world is going to change drasticly due to abundance of miracle-spewing mcGuffins. Magical items would become cheaper, yes, but at least the Crown ensures its position in riding that wave of changes. Routing majority - or all - magical items through Treasury also allows extensive research to conclude that these items do not, in fact, corrupt anyone who uses them. Nobody but the Government is going to fund that. [Answer] **Go to war** The problem is weapons are not selling well enough so they sit on shelves costing the merchants money. The merchants have to watch these unsellable but still quite powerful items sit idle while they fail to grow rich, the solution of taking matters into their own hands is bound to occur to them. So you need to increase demand for weapons. Take a good long look at your neighbors and maybe their neighbors, certainly there will be some choice land that has the wrong sort of people on it. Now is the time to see that properly grateful people are given a chance. [Answer] First Treasurer, Start by having the royal armoury buy all the excess magical gear from the merchants. Since demand is low those should be cheap. After acquiring enough weapons, let some kobolds and goblins loose in the city. They are low enough of a threat that the population will be able to exterminate them without excessive casualties, but enough of a threat to justify arming the population. At this point the royal armoury should distribute magical weapons and armour for the populace at a low cost. Once the threat has been dealt with, all the survivors will be armed to the teeth. The merchants will not dare mess up with them. Problem solved. Yours Truly, Renan, Bayesian Empirimancer of the 8th circle ]

[Question] [ Let's say I somehow got transported to medieval times. I have my phone, laptop or other devices with rechargeable batteries, but I forgot to take my solar chargers. Luckily, my every device is powered by standard micro USB cable, which I happen to have with me. I know that USB uses 5V direct current, from 0.5A to 2A. To create current, I can use magnets and copper wires, which are luckily sold by local merchants (wires) and magicians (magnets). This will, however, give me alternating current. Using some diodes I could convert it, but semiconductors aren't readily available in my local medieval shop. Next problem is, I need very specific and stable voltage. Definition of ampere won't help me unless I get two wires of infinite length. So question is: How can I create a stable current source to charge my electronic devices without exploding the batteries? This is related to question asked in [I was thrown into the middle ages, how do I power my time machine?](https://worldbuilding.stackexchange.com/questions/74991/i-was-thrown-into-the-middle-ages-how-do-i-power-my-time-machine) , but answers there don't seem to say much about voltages used. Phone batteries might need pretty specific voltage, and I'm mainly interested how I can either check the voltage of my source or build one having stable 5V (or some other that won't destroy my batteries). [Answer] Maybe use - A Galavanic cell , which uses chemicals which are available during medieval times . > > [](https://i.stack.imgur.com/QNtq1.png) > > > This electrolytes in this case is zinc sulfate and copper sulfate , but it can be also any other thing which has ions in it like maybe urine . Correct Voltage maybe obtained by trial and error method by varying the concentration of the electrolyte . We can calculate the potential using half cell reactions based on the material used - <https://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)> For 5Volt we can use - Ba(OH)2 + 2 e− ⇌ Ba + 2 OH− (−2.9v) and F2(g) + 2 H+ + 2 e− ⇌ 2 HF(aq) (+3.05) resulting would be around 5V. [Answer] It looks like your primary problem is measuring voltage accurately which is tricky with only medieval resources at your disposal. The actual construction of an analog voltmeter is actually not too hard, if you have measured components. If you look at the [Wikipedia page for Voltmeter](https://en.m.wikipedia.org/wiki/Voltmeter#Analog_voltmeter) you can see that you can make an analog voltmeter by just adding a resistor to a galvanometer, which is essentially a compass. You can then calibrate the voltmeter with you phone's battery, hopefully you can remember what the voltage is and that it can be taken out. Your biggest problem here is finding a resistor of a known resistance. You'll probably need to cannibalize some of your own electronics to find one, because you'll need to know the resistance pretty well if you want to get an accurate volt reading. [Answer] The thing you need is a [Voltaic pile](https://en.wikipedia.org/wiki/Voltaic_pile). It's very simple and you can make it out of any two different metals that you have available. Copper and zinc would be best but copper & iron will work. The advantage is that you don't need to be able to measure the voltage - just add more layers until the *charging* light comes on your phone. [Answer] Depends where you are. If you're in Southern Italy you can probably get hold of lemons. Add copper and iron nails and you have a simple cell. Chain them in parallel or series till you get the required voltage & current. [Answer] ## Unless you are an electrical engineer, you don't. There are too many smart en creative engineers between you and the medieval tech you find yourself in for one man (or woman) without the right knowledge to create the right electricity (voltage & amperage, etc). --- If you take the path of chemicals, you will have to work with acids. Good luck and have fun! Corrosive stuff, protect your skin and eyes. But you don't have the modern gear and probably don't know how to make them. How to game without eyes? Water wheel / windmill is safer(ish). Big moving parts that can crush you with ease. Remember, no workplace safety guidelines! Gaming with missing fingers can be interesting, I'll grant you that. And to get the right voltages is no mean feat. And you have very little or no way of checking the current. And that leads me to power spikes. Your modern gear trusts its power source quite a bit. And the medieval power source you created is anything but stable. Prepare to damage, short circuit or otherwise kill your beloved gear. --- **Then what to do?** Turn off your gear, and try to get back to a time where you have a stable power supply. Maybe turn up at Alexander Graham Bell's door, he might be able to help you. Tesla will work for sure. [Answer] If you're in a medieval fantasy setting with magic, you might be able to use necromancy magic to turn your dead battery into an undead battery, and power your phone that way. [Answer] A LiPo/LiIon battery is never ACTUALLY discharged to 0V (this would leave it beyond repair) - your discharged battery (if you can access the battery terminals directly) can be used as a voltage reference of close to 3V per cell, so you can compare other voltage sources (eg by a bridge circuit - all you need is SOME voltage indicator (headphones!) and some changeable resistor (eg carbon)). Also, so called "charger" plugpacks are almost never the actual charger - which is in the phone/laptop, and which will take care of handling the battery correctly unless you feed it GROSSLY out of range voltages. [Answer] Following on from AmruthA's answer, you are better building a voltaic pile, rather than two half-cells in jars. These are stacks of zinc-felt-copper discs, with the felt is soaked in brine. A diagram of them looks like this <https://upload.wikimedia.org/wikipedia/commons/0/06/Voltaic_pile.svg> (stackexchange isn't letting me upload the image). A practical pile is placed between two large wooden plates, a bit like an old-fashioned egg-timer. The pile has to be pushed together to make sure that the discs are in close contact, but without enough force to expel the brine from the felt.They look like this <https://upload.wikimedia.org/wikipedia/commons/5/54/VoltaBattery.JPG> Zinc was purified by 1300 in India, but pure zinc wasn't exported to Europe until 1600. A zinc-copper pile produces about 0.7V per cell. In the absence of zinc, you could use copper-tin, but that produces a considerably lower voltage, about 0.13V per cell. However, tin was readily mined in Cornwall (SW England). [Answer] You can construct a [voltaic pile](https://en.wikipedia.org/wiki/Voltaic_pile), an early battery. All you need is copper, zinc, and salt water, all of which can be found in medieval times. Each copper/zinc/salt water soaked rag produces .75 volts. Put seven together in series, and you have 5.25 volts, enough to charge the phone... (they charge using 5 volts DC through the USB port). Of course, if you're in medieval times, you'd also have to invent a cellular network and maybe GPS satellites (plus a way to get them into orbit), or the phone won't be of much use. That might prove to be a bit more difficult... [Answer] ## Charging your phone is easy, meeting your specific requirements is close to impossible ## How to generate percise and stable voltage There are a lot of ways to create some current but the easiest method to create a really homogenous voltage in a way that we can tell exactly how strong it will be, should be to use the [thermoelectrical effect](https://en.wikipedia.org/wiki/Thermoelectric_effect) (in form of the Seebeck effect). It occures when two different connectors are exposed to differenct temperatures at either end. The resulting voltage is comparably low bu it is only affected by the material of the conductors and the total difference of temperature - and using phase transition, we can make the temperatures highly stable. To use this phenomenon we only need conductors of different metal, two containers of water, ice and fire wood. Make the water in one container boil at east a little bit and make sure there is at least some ice in the other one (this way they will be exactly 100°C and 0°C respectively). Than connect both of them using e.g. iron whire and use e.g. copper whire to connect both poles of your charger with one container each. Those two metals are easily accessable in medival Europe and result in percicely 12.5µV per Kelvin whothc is a slight problem but will turn out in our adventage later. 12.5 µV per Kelvin won't be enought so we need a [thermopile](https://en.wikipedia.org/wiki/Thermopile), connecting several conductor pairs. Since Kelvin is based on Celsius and Celsus is based on the temperature diffference between freezing and boiling water, we get the most exact 100 Kelvin difference there will ever be and thus get a resulting 1.25 mV per pair of connectors. To reach 5V, we would need 400 pairs of conductors that must not touch each other. Again, this is somewhat inconvenient but it does not require any unusual materials and gives us a voltage of precisely 5V that will not change over time (unlike any method that is based on Galvanic redox). Another drawback is that ice is not necessarily readily available in medival Europe. In winter, far north or near mountains it is available and using an [ice house](https://en.wikipedia.org/wiki/Ice_house_(building)) or ice cellar you could secure a supply throughout the year. Ice houses and similar constructions have been invented centuries before the medival ages even bagan but they didn't become popular in Europe before the 16th century so you won't be able to rely on profound methods being in place. But then again that is not wat you need. You only need enought thermal insolation to keep the ice from melting completely and even that might not be necessery depending on when and where you end up. ## How to assure the percice current Given the voltage, the current is dictated by the resustance. Unfortunately there is no way for me to know the resistance of your phone, the average resistance per lenght of wire for the contuctors you will use and how much of it will be used. Tht is even assuming that Galvanic elements have no inner resistance neither have connections between conductors (whitch will add up for any method but especially with the n=400 thermopile I suggested). As long as noone can provide a model that allows us to predict the resistance with a reasonable percision, meeting your requrements (even as they are a rather big interval) is practicly impossible. I do belive that you would be able to charge your phone using my method but that goes for any other method as well, as long as it allows you to calculate the resutling voltage. [Answer] Refer to section on Gravity Cell in this page: <http://members.kos.net/sdgagnon/te4.html> Telegraphy was the first electrical technology to spread (widely) beyond the laboratory. It was entirely powered by batteries at each station along the (iron) wire. Copper and Sulfur (both well known to the classical world) should be relatively easy to obtain in the middle ages. (Remember that your paper money, debit-cards, and bitcoin will be met with laughter at best.) [Zinc](https://en.wikipedia.org/wiki/Zinc) on the other hand was poorly understood as a distinct metal. Despite having been used in various chemical compounds for thousands of year, you have to wait until the Enlightenment for the actual metal: in Europe "German chemist Andreas Marggraf normally gets credit for discovering pure metallic zinc..." [1746] If you plan on smelting your own Zinc, be advised that the fumes present a health hazard. For this reason, Welders are told early on to avoid welding Galvanized Steel. --- As you have remembered to bring your electronic amusements, your best choice is to remember to bring solar cells, and hand- or wind-cranked generator(s). [Answer] Lets just take a second to think about the implications of this during that time period. electricity in a time where you would be killed for any number of reasons including looking at a king or queen wrong. I would ditch the phone and use my engineering experience to carve out a kingdom of my own. Build infrastructure, machines, unfortunately weapons will be needed. As an engineer i am sure you know the basics behind a rifle and can work one together in some fashion. keep in mind you know how to make steel. so a better question is why do you want a useless phone when you can rule the damn world. [Answer] Build an [electrostatic generator](https://en.wikipedia.org/wiki/Electrostatic_generator) of roughly correct power level. Build a [Leyden Jar](https://en.wikipedia.org/wiki/Leyden_jar). Connect the generator to the jar. Connect the jar to the phone. Use the generator to charge the jar until the voltage gets high enough and the phone starts charging. Experimentally discover the rate you need to run the generator for the phone to keep charging. Your phone can detect the voltage and regulate the current. Just provide a power source and something that prevents voltage spikes above what the phone can safely handle. Adding a resistor to prevent over current might be good also. [Answer] ### Batteries and Mobile Phones Potato batteries, lemon batteries, apple batteries, it really is less complicate than it seems because modern mobile phones know to shut down the power source as soon as the internal battery is full, so you can't overcharge except if you really send the sparks flying. You shouldn't pile dozens of potatos, but you will be able to find out by try and error how many potatoes you need to stack until your phone shows something on the display or the charging LED. You will need some metals, though... ### Versatile Charger If you still have your charger with you, it's even better. They have as input 110-240 volts with 50Hz to 60Hz; so, that's total flexibility. It's in express made so that they fit both the American and Europe systems without problem. Their flexibility makes that you can input any oscillating voltage and the charger will reliably fill your device without destroying it. ### Making a alternating current generator So if you are able to find some lengths of copper, silver or gold wire and a magnet, and you find a way to rotate the magnet inside a selfmade spool, you can just attach your charger with very little precaution and it is highly probable that it just works. Don't exaggerate, though - if you accidentally produce a thousand volt it will still burn out. Your character probably wants to use a very small iron heater as resistor to discharge exceed voltage. Hint: If the sparks bridge more than 2-3 mm (0.1 inch) then it's too much. You can use this as sort of a security precaution, too: Put your two wires in one spot as close as 2mm, not isolated, and any current that's too high will spark away. ### Wire Now, getting a useful length of wire in the middle age is a real constraint. You can't use steel or iron; they would heat up too much. Could be a nice first experiment for your character, though. Silver is just perfect (best conductor) but expensive, copper is still quite ideal but getting it into wire form is as difficult as for silver, gold is less ideal, more expensive still but easy to make into a wire. Your character will spend a lot of money for blacksmiths just for the material and to make wire. ### Magnets Worst problem will be to find a magnet. If you can rotate a magnet inside a spool, you've won. You can even magnetize a bigger block of iron once you have the first one down. But where do you find the first usable magnet? Well, your character probably has to go back back to the potato battery to magnetize the first piece of iron. What do you want with a smartphone in medieval times? [Answer] I suggest forgoing the idea of creating generators/dynamos/alternators and simply going for a simple battery: ## Create a Lemon battery [](https://i.stack.imgur.com/9tdZg.png) According to [sources](http://hilaroad.com/camp/projects/lemon/lemon_battery.html) a single lemon battery cell creates around 0.9V in voltage. If you add 5 of them in series you should get some 4.5V which might be enough. Then simply scale the entire thing up in parallel to increase the current until you reach the needed amperage for your phone. Edit: I even found this proven in a [YouTube video](https://www.youtube.com/watch?v=YYf4UOA4-9k). **Needed materials:** * Lemons * Copper * Zink * Wiring of some sort ]

[Question] [ [65 million years ago](http://en.wikipedia.org/wiki/Cretaceous), a mass extinction event (likely caused by the [Chicxulub Meteor](http://en.wikipedia.org/wiki/Chicxulub_crater)) wiped out the dinosaurs, and their remains were hidden from us for millions of years. Humanity was not around at the time, and there were no major societies or civilizations. But what if there had been? What if there had been a race or civilization at that exact moment in history, approximately like our own currently, but with an advanced spacefaring device that allowed them all to leave at once, leaving only behind the ruins of their society? What would be left over from their society, assuming they used similar methods of construction and had similar cities, factories, and historic periods to our own, that we would be able to find in modern times? UPDATE: To clarify, there would be no fossil records of the actual civilization (all their dead are cremated before departure, and their evacuation is 100% complete, pets included) only the artifacts left behind by their civilization (all habitats, entertainment, and food are provided on their escape vehicles, but everything they had is left behind). And they are not humans, but approximately close enough bipedal creatures that they're very similar to humans. UPDATE 2: Assume that they won't be doing anything to impact our world. They could be coming back tomorrow, settled on other worlds, gone forever in a horrible accident, but they can't be having an impact on our world, and we likewise aren't going to find evidence of them from anywhere but here. [Answer] An industrial civilization on the same technological scale as our own would leave a layer of odd chemistry in the rock, ratios of isotopes out of whack. Here are some possibilities. Fossil fuels are made of very old carbon where most of the radioactive carbon-14 has decayed into carbon-12. Our digging up and burning of fossil fuels is putting far more carbon-12 into the atmosphere than carbon-14 than would by natural processes. This change in the ratio of carbon-12 to carbon-14 would be detectable in the industrial layer... **UPDATE** *as @Keith correctly points out carbon-14 would have decayed to undetectable levels in less than 100,000 years.* Similarly, there would be elevated levels of other compounds locked up in fossil fuels such as sulfur, mercury, uranium, thorium, arsenic, and other heavy metals. Any nuclear industry would leave behind [nuclear waste](https://en.wikipedia.org/wiki/Radioactive_waste#Nature_and_significance_of_radioactive_waste). Some waste products are very short lived, but [others like Zirconium 93, Caesium-135, Palladium-107 and Iodine-129 have half lives in millions of years](https://en.wikipedia.org/wiki/Long-lived_fission_product#The_7_long-lived_fission_products). In addition, the stable products they decay to (lead, iron, xenon) would be elevated. [Answer] Dinosaur fossils are dug up all of the time. Including things like fossilized teeth. I wonder what researchers would say to a gold nugget embedded in a tooth. Things like clothing, watches, ... might leave impressions in the stone, just as there are fossils with skin or feather impressions ([wikimedia link to Archaeopteryx](http://commons.wikimedia.org/wiki/File:Vog1h.jpg)). What happens to ceramics in sedimentary stone? At least impressions, I'd guess. Nuclear waste could make people wonder, or come to completely wrong conclusions about the natural formation of radioactive materials. [Answer] The most likely remnants would be **Space Artifacts**. 65 million years is such an insanely long time that almost anything left will be wiped out, either by natural processes, chemical reactions (oxidation, etc), or even geological events - the continents of the world are very different now, those changes could have destroyed things. Not to mention that the meteor event itself would cause significant destruction. Now, it's unlikely that you'd find anything in orbit. But you might find ancient satellite remnants in some of the [Lagrange points](http://en.wikipedia.org/wiki/Lagrangian_point) - these are gravitationally stable points between the Earth and Moon, and it's possible they'd collect some of the Dino's old satellites. You probably wouldn't get something entirely intact - micrometeorites add up over 65 million years - but you could get parts that are clearly artificial and non-human. Another possibility here is the Earth-Sun Lagrange points, which are further away. More likely to be intact would be a space base somewhere in the solar system. Many other bodies are non-active geologically, which will help preserve a base, and if it's buried it's protected from micrometeorites. These could easily be wiped out by a larger impact, though. [Answer] Most of the answers so far are focusing on accidental evidence. But since the civilization was able to leave, they obviously knew the event was coming with some amount of lead time. This makes it quite likely that they would've attempted to leave intentional long-lasting evidence of their presence. This might be messages encoded using long-lasting isotopes as others have mentioned, or perhaps messages left on the moon itself, where the materials are less likely to break down. [Answer] There would be very few, if any surviving artifacts remaining if there was an advanced humanoid society at the time of the dinosaurs. There would have been very significant Earth changes between that time and now. If we traveled back to that time, we would have a hard time recognizing the world. Continents would not be in the same place as they are now. Climate and atmospheric conditions including weather patterns would be alien to us. Sea levels would be drastically different. There could be entire landmasses existing which no longer exist today. Mountain ranges that we know today may not have formed yet. Other features that we know well today would not be present like the Great Lakes, Long Island, and all of the other geological formations which were formed by glaciers during the ice ages. Because of these differences, it would be very tough to pinpoint where to even look for these civilizations in the modern day, even if we knew where they were in the past. They could be deep underwater, or at the top of a mountain, or they could have been vaporized by a volcano, or a meteorite or asteroid collision. These cities could have also been sucked into a subduction zone and melted into the Earth's crust. If this civilization attempted to come back to Earth after all that time, there would most likely not be any remnants of their civilization. It would all be buried deep in the sands of time. It may be possible that there could be fragments of their civilization remaining. However, it would be difficult to identify these remains as nothing more than an oddity. Over the years, there have been several claims about people finding artifacts that supposedly came from extreme antiquity. Most of these claims have proved to be dubious or completely unfounded. They are usually just the result of elaborate hoaxes brought on people with an agenda. Even if legitimate evidence was found, it would be very difficult to prove that it was made at the time of the dinosaurs. There could be some form of advanced technology available which could accurately date these remnants. There would be very little evidence of the buildings themselves. Any structure made out of wood or metal would have returned to its natural state long before modern humans could lay eyes on it. The only thing that may be left over are features made of stone which may have been buried millions of years ago and preserved. [Answer] **There would be abundant fossil evidence of their buildings, tools, art, technology and trash.** As abundant as other fossil evidence from the same period, at least, which would be plenty to show many clues about the civilization. Consider: How do we know that dinosaurs existed at all? Fossils from their time. We also have fossils of plants, insects and microbes from even before their time. If as you say they left behind entire cities, and had a pre-modern history, there would be many fossils left of all the stuff they built and made and wore and littered and lost and so on. The oldest insect fossil is about 400 million years old. Here's an insect wing from over 100 million years ago: <http://en.wikipedia.org/wiki/Necroraphidia#/media/File:ZooKeys-204-001-g004_Necroraphidia_fig1.jpg> Given the right circumstances, such as ash or mud suddenly covering a town and later being uncovered, there could be decent archaeological sites too, although they might be sites of fossils and impressions rather than intact objects. Major constructions could leave recognizable traces too: roads, aqueducts, industry, dumps, scrapyards. [Answer] Some salt deposits were created 250 million of years ago in geologically stable areas. They have remained undisturbed until humans start burying the waste of nuclear centrals, see [why the U.S. government chose salt mines to bury long-lived radioactive wastes](http://www.wipp.energy.gov/fctshts/salt.pdf "Why Salt was Selected as a Disposal Medium, U.S. Department of Energy"). It would be the most obvious place to bury artifacts for the benefit of later civilizations. With no running water and humidity, you could even get away with storing paper! [Answer] It seems to me that the subsequent evolution of Velociraptor, some million years before dinosaur extinction, would be the place to look for potentially intelligent species. They were effectively bipedal, forearms with claws for manipulation, and social (hunted in packs). One idea: if some brainy dinos survived (or anticipated) a mega-collision, other than leaving Earth, they could have moved underground? I speculate that extraterrestrials described with large eyes are evidence of subterranean life (after all, where could you live on Mars or on bombardment-likely planets but underground? John Caddy [Answer] Great question. Many of the products of civilization could survive, particularly large structures, and items of particular metals. I'd expect most of these to be deeply buried in strata, much of it inaccessible. However, if the civilization was global, some areas of land surface would survive and hence be able to show traces. For example, most of the Australian continent was around 65M years ago or longer. It's not obvious to me that one should look in the regular fossil beds, but I stand to be corrected. Such sites have a duration that might be very long relative to a civilization. Presuming that they represent swamps or river or lake beds, I guess a certain amount of junk might end up there, but not necessarily. I agree that isotope anomalies the nuclear industry might be an indicator. However, if one does not find the site of a reactor or accident, I do not know that the overall environment would leave evidence in the strata. In conclusion, I suspect evidence would be somewhat hit and miss with not a lot to show for it today. At the same time, I think that means that a civilization of our current level of industrialisation or above would have left a fair amount of evidence scattered around. [Answer] I've seen this question asked elsewhere many years ago. The most convincing answer for me was that EARTHWORKS would be fairly easy to find millions of years later. Any advanced civilisation would rely on metals and getting them from the ground often involves opencast mining - leaving a huge pit in rock which will tend to be filled in such a way that its purpose is clear to future archaeologists. [Answer] The easiest way to detect such a civilisation after 65 million years is to look at its effects on other life. You'd be looking for geological evidence of a mass extinction 65 million years ago, like the one that's in progress at present, as the dinosaur civilisation expanded and used up the available biological resources for itself. [Answer] Mines and mineral deposits. Many of the mines humans have exploited through history were formed long before 65 million years ago, which means those resources would have been there for some civilization to exploit, but yet those deposits were untouched prior to humans working them, indicating no one else had been around to exploit them first. If one had, that's a huge honking clue. You'd find things like underground deposits where what should be the richest ore was missing, replaced by what looks like filled-in tunnels that show unnatural regularity. You'd have surface deposits where, again, the richest ores were missing, leaving a halo of surrounding lower-grade rock surrounding a plug of sedimentary rock, what you'd expect if someone had been open-pitting and the mine had gradually been filled with sediment. You'd see areas of very fine mudstones with disseminated minerals that looked in no way natural, the remains of tailings. And so on and so forth. Now, mines tend to take up a geographically small area so the odds of just stumbling on the remains of one a few million years old are small, but their locations aren't random; they're determined by geology a lot older than this hypothetical civilization, and where they'd mine is where we'd currently be looking for things to mine. Someone, at some point, would have stumbled on something so freaking anomalous that everyone would know about it. [Answer] A civilization advanced to the point of leaving the planet before a catastrophy might as well have the means to restore parts of it to its previous state. They could, for example, build some sort of "Noah's Ark", where eggs and embryos (or the genetic information) of the most threatened species could be stored, allowing them to repopulate the Earth after some time. In this scenario, the "leftovers" of such a civilization would be dinossaurs surviving up to our time. [Answer] See this paper [The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record?](https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/silurian-hypothesis-would-it-be-possible-to-detect-an-industrial-civilization-in-the-geological-record/77818514AA6907750B8F4339F7C70EC6) Looks like Nitrogen-15 level would be a tell (fertilisers), also Plutonium-244 (half-life 80.8 million years) and Curium-247 (half-life 15 million years) produced by nuclear industry, also some specific chemicals: > > steroids, leaf waxes, alkenones and lipids can be preserved in sediment for many millions of years (i.e. Pagani et al., 2006). > > > [Answer] Imagine if the human civilization suddenly ceased to exist. What would a future geologist or paleontologist find of our civilization. Assuming it is 65 million years after we're gone, not much. By this time, metals have been corroded, concrete structures such as sidewalks and damns has been eroded away and plastics have been biodegraded. Most of our satellites have fallen back to earth by this time. Unless for some miraculous situation where a bunker or sanctuary had survived for this amount of time, the only safe place is space. However, some of our spacecraft, including the voyagers would survive to this time, assuming nothing went wrong. Even if a dinosaur civilization did develop in the Cretaceous, any surface structures would be long gone. A subterranean bunker would stand a better chance of surviving, especially if it was far enough away from fault lines where volcanoes and earthquakes wouldn't be a problem. As a space faring species, if they were as advanced as us, the only place they could really go is mars, but even that is unlikely. However, no one can say with certainty that a dinosaur civilization did NOT exist. ]

[Question] [ Faster than light travel is a *really cool* thing to have in sci-fi settings. It allows humans, in relatable time scales, to travel the galaxy and see a variety of worlds. It allows for conflicts spanning not just a solar system or perhaps a solar system and its nearest neighbors, but huge sections of the galaxy. FTL communication, meanwhile, allows governments and organizations to exist that span huge sections of space, something that might otherwise be impossible if communication between planets took decades, centuries, or even millenia. The only problem with allowing FTL travel is that is *also* allows time travel. Most sci-fi settings with some form of FTL ignore this fact, choosing to leave it unaddressed and focus on the story. There is nothing wrong with this. However, it would be more satisfying as a science loving story teller to have some sort of explanation as to why FTL doesn't allow people to travel back in time. Are there any ways to construct or limit FTL travel that would let people travel between points light years apart without allowing for time travel to take place? I'm fine with solutions that stretch our current understanding of physics, but would prefer to keep everything as believable as possible. Any form of FTL travel, be it wormholes, advanced engines, or some sort of hyperspace dimension is acceptable, so long as it doesn't permit the travelers to travel back in time. [Answer] As you said, any FTL drive is implicitly a time machine. Let’s review the reasons why. As a prerequisite you need to understand [spacetime](https://en.wikipedia.org/wiki/Spacetime) and the ideas of **space-like** and **time-like** [intervals](https://en.wikipedia.org/wiki/Spacetime#Spacetime_intervals_in_flat_space). # first you need… We will make use of [space—time diagrams](https://en.wikipedia.org/wiki/Minkowski_diagram#Minkowski_diagram_in_special_relativity) which show that events (points in spacetime) have different x and t values depending on your reference frame. I thought I had first learned of them through the [Alternative View](http://www.npl.washington.edu/AV/av_index.html) column in *Analog*, but I can’t find it. I think the illustrations are not archived here. But, a number of the essays involve wormholes, warp drives, and other related subjects, so it well worth going through his archive now. (I'll wait ☺) A more recent tutorial is [Sharp Blue: Spacetime and coordinates](http://www.theculture.org/rich/sharpblue/archives/000182.html). An observer in uniform motion traces out a straight line, called his *world line*. He is at rest in his own reference frame, so this becomes his time axis: his x value stays 0 and his clock ticks away. Meanwhile, his x axis—points of equal time—will appear to be angled by the same amount off the parent diagram’s axis. That is, it is squished. Furthermore, the scale of the tickmarks is different. [Formally](https://en.wikipedia.org/wiki/Special_relativity#Reference_frames.2C_coordinates.2C_and_the_Lorentz_transformation), you can note that the [**interval**](https://en.wikipedia.org/wiki/Spacetime#Spacetime_intervals) can be computed and is the same in any reference frame. The particular *squishing* and *scaling* of the moving reference frame’s axis explains all the effects of special relativity we have heard about: time dilation, length contraction, and puzzles such as the [pole-in-barn](https://en.wikipedia.org/wiki/Ladder_paradox) can simply be *read off* on such diagrams.  > > (from Wikipedia) **Minkowski diagram of ladder paradox.** The garage (barn) is shown in light blue, the ladder (pole) in light red. The diagram is in the rest frame of the garage, with x and t being the garage space and time axes, respectively. The ladder frame is for a person sitting on the front of the ladder, with x′ and t′ being the ladder space and time axes respectively. > > > # time travel happens Consider two planets around distant stars, A and B. Their world lines are drawn in the following diagram as vertical lines. Our traveler Charlie has a FTL drive that (through whatever sci-fi trope we choose) can jump from one planet to the other “instantly”. I will choose *instantly* because it is the simplest to show. Any speed faster than light and longer than instant will have the same effects. (And any speed faster than instant is explicitly time travel into the past so that case is trivial.) Now I put “instantly” in quotes because time is relative. I drew a line of equal t at different positions, with the t axis as used by the reference frame of A. (And for simplicity, B is at rest relative to A; but see *Coda* below.)  In spacetime no reference frame is better or worse or different than any other. If my drive makes instant jumps, then we are saying that it is instant in the reference frame which the pilot is in when he engages it. So, look at the point of view of Derral, who is passing near planet A at the time Charlie made his jump. Derral is moving along a line in the direction of B to A (since we are only showing one space dimension) at a noticeable fraction of the speed of light. The red line is D’s position at any time, so this is not just his path on the diagram, but his t axis: he's at rest in his own reference frame and the planets are moving, from his point of view. So, his x axis is also different, and that’s labeled in the same color, and called xD in short.  In Derral’s reference frame, on this drawing points *at the same time* are those lying on lines parallel to xD. So, Derral engages his jump drive at the same time as Charlie, and ends up at point D2, which beats Charlie's “instant” arrival! Derral has to slow down and then return to planet B, which he has plenty of time to do since such a maneuver stays within B’s *past* light cone. (Alternatively he could have overshot B’s world line and dropped back into normal space within B’s past light cone and let his high velocity take him back B.) Thus, **due to symmetry**, the FTL drive functions as a time machine. You can choose your spacettime axis, jump far enough to amplify the difference between time axes of different observers, and travel into your past using multiple jumps or travel into the past of another traveler. ## multiple FTL trips required An intro recommended by some other WB beings is [Sharp Blue: Relativity, FTL and causality](http://www.theculture.org/rich/sharpblue/archives/000089.html). It covers this same introductory material, noting how a *second* superluminal signal causes a causality violation. You will notice that Derral cannot return to the past at planet A by making normal spaceflight. We will illustrate this by drawing a diagram with the *jump* being a very extreme angle, near that of the light cone – i.e. the pilot was moving at highly relativistic speed when engaging the jump. As we postulated earlier, the angle will always be to a space-like separated point outside of his light cone. If it was inside of the light cone, it would be either not-FTL or explicit time travel. If he jumps any distance away, and then returns as fast as possible (the 45° angle of light on the diagram) he will always return later than he left.  Although any space-like jump can be viewed as time travel in some reference frame, only multiple jumps in *different* reference frames can cause a causality violation. # Break the Symmetry The solution then is to disallow that. We don't want to disallow more than one jump *ever* since it would not be a useful drive. Instead, **introduce a preferred frame of reference** and have all jumps use the *same* x and t axes. See also [Jason W. Hinson’s presentation](http://www.physicsguy.com/ftl/html/FTL_part4.html#subsec:specialframe). ## It fits with existing tropes This is easily done as part of the drive description. For example, you access a subspace dimension, and there is an absolute or preferred reference frame associated with that subspace e.g. it has a medium filling it. More complex explanations are possible: our universe has a *distinguished* reference frame defined by the average motion of everything in it and easily seen from the [microwave background](https://en.wikipedia.org/wiki/Cosmic_microwave_background). The stuff in the universe has specific reference frames, but spacetime itself and the laws of motion do not. You need to find a reason why some *thing* in the subspace universe matters to our ability to move through it, or how it connects to the spacetime of our universe. Of course, if it wasn’t so, then we would not have the necessary limitations to make FTL travel possible without causality violations, so you could use an anthropomorphic argument that if it were otherwise we could not have accessed it. ## It provides story potential This also offers some interesting plot points that fit with it. In particular, suppose that the specific reference frame isn’t just the line that’s followed when doing a jump. Rather, the ship must be in that specific reference frame in order to engage the drive! Now this could be matching the CMB rest frame, or it could be something at an inconvenient relativistic speed compared to the stars and planets we are moving between. Option A is that the drive won’t work unless at rest in “the” jump frame. Option B is that a ship that jumps while in a different frame will arrive all smeared out in space and time, since the ship was not simultaneous with the transit but interpreted different parts leaving at different times! Ouch. Note that proof of being safe for causality required the light cones to be parallel in all places. What tips light cones is [*general* relativity](https://en.wikipedia.org/wiki/General_relativity). So, we can avoid running into problems by postulating that the drive doesn't work in a strong gravitational field. Note that this is also an existing trope, and comes about naturally from option A. Warped space is not the same reference frame you require! So, ships must travel far from the sun first, and Earth-based observations (nor astrophysical effects involving stars themselves) would not ever show anything that would lead to its discovery! Niven’s [*known space*](https://en.wikipedia.org/wiki/Known_Space) universe used that effect to explain why [Outsiders](https://en.wikipedia.org/wiki/Outsider_(Known_Space)) sold the tech to planet-hugging species like ours. And finally, you can complicate matters by having this design break down. *Normal* use of the drive does not involve time travel. [But what if you prepared a flat patch of spacetime that was itself deep in a gravity well?](https://physics.stackexchange.com/questions/198132/gr-time-dilation-cares-only-about-local-curvature-right) What if there was not just one jump frame, but others waiting to be found? Perhaps there is a whole series, at successively higher velocities in our space, or *things* in the subspace dimension can be changed and manipulated. In general, use the flaws and rough edges of this drive explanation for plot potential rather than cause to reject it as not being “hard” enough S-F. --- # Coda: A and B are always in different reference frames See [the Andromeda Paradox](https://en.wikipedia.org/wiki/Rietdijk%E2%80%93Putnam_argument). Just two people passing in the hall will have different reference frames, and ever so slightly different planes of what they consider to be *simultaneous*. That slight difference in x axis (that is, all x where t=0) can be amplified by distance so that in another galaxy it is *clearly* a different time, a different day. Planets around different stars will have relative velocities orders of magnitude greater than walking speed, just from the difference in orbits and the star’s movement within the galaxy. # How do I interpret this? See: [How does paradox-free FTL travel affect the details of my story or gameplay?](https://worldbuilding.stackexchange.com/questions/47166) [Answer] Yes, you could use [traversable wormholes](http://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes) (which have a reasonable degree of scientific plausibility since they are solutions to the equations of general relativity, though they would require ['exotic matter'](http://en.wikipedia.org/wiki/Exotic_matter) to construct) along with Stephen Hawking's [chronology protection conjecture](http://en.wikipedia.org/wiki/Chronology_protection_conjecture). Traversable wormhole can only be used for time travel when the two wormhole mouths have been arranged in certain configurations, and the chronology protection conjecture says that at the moment you cross from a configuration that doesn't allow time travel to one that does, you get a feedback loop of virtual particles between the two wormhole mouths that destroys the wormholes or causes some other unknown [quantum gravity](http://en.wikipedia.org/wiki/Quantum_gravity) effect to kick in that prevents them from being used to send anything back in time. For more details on this see the wikipedia page on the conjecture or a book like [*Time Travel and Warp Drives*](http://rads.stackoverflow.com/amzn/click/022604548X). In configurations that *don't* allow time travel, traversable wormholes would allow for a type of effective FTL in which you could reach a distant destination and return home in much less time than it would take light traveling through the ordinary space outside the wormhole (though of course light that traveled along with you through the wormhole would still move faster than you as it passed you by, so a physicist would say that nothing moves 'locally' faster than light in this scenario). [This page](http://www.aleph.se/Trans/Tech/Space-Time/wormholes.html) has a good article by Michael Clive Price that explores some plausible science-fictional consequences of FTL travel via wormholes, assuming the chronology protection conjectures holds (he notes at the top that a revised version of the article appeared in *Extropy* #11, which is available online as a pdf [here](http://fennetic.net/irc/extropy/ext11.pdf), with the article starting on p. 14). For example, one interesting consequence is that each civilization would probably send out wormhole mouths traveling at nearly the speed of light (while retaining the other mouth at their home system), and due to [time dilation](http://en.wikipedia.org/wiki/Time_dilation) a clock traveling alongside a wormhole mouth might measure very little time to reach very distant locations, for example the clock might measure only 2 years to reach a star that is 100 light years away in the [inertial frame](http://en.wikipedia.org/wiki/Inertial_frame_of_reference) where the Earth is at rest (in the clock's own rest frame the distance would be shrunk due to [length contraction](http://en.wikipedia.org/wiki/Length_contraction)). This means that we on Earth would also measure a time of only 2 years before we'd be able to step through the mouth we kept on Earth and arrive at a destination 100 light years away--but we'd be arriving over 100 years in the future, as measured in a reference frame where the Earth is approximately at rest. But then if we stepped back through the wormhole, we'd arrive back on Earth very shortly after we left. So, the author of the page suggests interstellar empires using wormholes to reach distant locations would use some type of "Empire Time" that would be different than time in the Earth's rest frame, and would treat an event happening 100 light years away and just slightly over 100 years in the future (as measured in Earth's rest frame) as happening on the same Empire Time date as an event happening on Earth today. In effect, all events on our future [light cone](http://en.wikipedia.org/wiki/Light_cone) at the moment we first started sending out wormholes at close to light speed would be treated as happening on about the same date. Another related consequence: if we ran into an alien interstellar empire that was also sending out wormholes, we would *both* agree that the event of our meeting happened a relatively short (on historical scales) time after we first began sending out wormholes, in terms of Empire Time. So, just as in many space operas like Star Trek, different alien civilizations would all encounter one another at approximately the same level of technological development, even if they evolved millions of years apart in ordinary non-Empire-Time. [Answer] Most forms of FTL travel have problems with time travel when either FTL signals are sent in opposite directions or the FTL vessel travels first in one direction and comes back again. Therefore, one solution to time-travel-free faster-than-light travel is that FTL travel can only happen in one direction. This concept was developed by Adel Antippa in a series of papers that can be found [here](http://www.adelantippa.com/Personnel/publications_folder/relativite_folder/tachions.html). Antippa and his co-authors were investigating the possibility of superluminal frames of reference. Everett apparently gave up when the model he was working on required three dimensions of time and he found it conceptually and psychologically too difficult to imagine what they related to physically. In two dimensions Antippa's tachyon corridor only allows superluminal motion in one spatial direction that always increases. This is equivalent to the way in our sublight world it is time that always increases and in one direction. If FTL travel was confined to a two-dimensional submanifold of spacetime and in only one direction spatially this leads to one form of FTL travel with time-travel. This would allow a spacecraft travelling to, say, Sirius at FTL velocity, assuming Sirius lies along the tachyon corridor, but the spacecraft would to make the return at sublight velocities. This does lead to a weird and wacky universe with FTL travel only one way in a specific direction and orientation. All other travel would be either purely sublight or a combination of sublight and with various stretches at FTL velocity along the tachyon corridor. This model does assume there is a practical mechanism for transitioning from the bradyon (or sublight) domain to the tachyon (or superluminal) domain. Possibly this might be conceptualised as a form of quantum tunnelling. For example, Stanley Schmidt came up with something like that in his Kyyra SF novels where he had a not too unreasonable model for tachyonic FTL travel. Traversable wormholes are almost scientifically feasible options, at least, at the conceptual level. However, if an interstellar civilisation set up transport networks with wormholes. Now because a trip through a wormhole across astronomical distances is also a trip into the future, this means stepping back through the same wormhole means going from the future back to the past. If there are two sets of pairs of wormhole mouths (basically two wormholes going in opposite directions between locations A and B) this means time travel becomes possible. One solution is that if photons can pass through both wormholes and continue circulating back and forth in time this will amplify into a massive radiation flux that will eventually destroy the wormholes. Also, making any trips through the wormholes fatal. Another solution is to set up wormholes in a series through a transportation so each wormhole is effectively in the future of the wormhole that you need to travel through to reach that system. \*\*For example, there is a wormhole connecting Sol to Tau Ceti. The next wormhole goes from Tau Ceti to Alpha Centauri, then Alpha Centauri and Sol are connected by a further wormhole. This wormhole network is arranged in an approximate circle. Travellers can only go forward and with no backtracking between a pair of connected systems, but a trip starting at Tau Ceti would have to go right around the network proper before returning to Tau Ceti. Undoubtedly, travel would be further safeguarded by Customs and Security. Most people opposed to time travel are concerned with causality violation and rightly so. In the universe we see around us, common causality is almost invariably the case (I say this, because if there were any causality violating events their incidence is indescribably small, in fact, quite undetectable). This is despite the fact that most physical laws are time symmetric and this of itself should allow forms of time travel like processes, but this doesn't happen. Therefore, it is not unreasonable to assume our universe has what could be called a strong causality condition. This acts to 'suppress' any event that leads to causality violation. There is no reason not to suppose that if there was auniverse where FTL travel, either tachyonically or by traversable wormholes or Alcubierre drive vessels that the strong causality condition would also apply. This would FTL travel but any FTL trip (and this includes FTL signals) could only happen in a manner that avoided time travel. Edit: I had assumed, but failed to explain, that the ring of traversable wormholes are installed on after another and going around the ring itself. This means Sol to Taul Ceti, followed by Tau Ceti to Alpha Centauri, and then Alpha Centauri to Sol. \*\*: I am going to disagree with myself. I have decided to leave this example in my answer to show how easy it is to go wrong. Essentially a wormhole network works without causality violation if the network isn't closed. Also, it would work, at least, conceptually, if strong causality existed as an attempt to form a closed timelike curve would be blocked. Implicitly the ring of wormholes was structured as if weak causality was in place. The example of the wormhole network is feasible if it isn't closed. As long as the wormhole isn't closed this prevents causality violation from happening. Although in practical terms we have never to have worry about whether FTL travel leads to time travel (except at a theoretical level) because the technological requirements for FTL travel are too incredibly extreme to even remotely achieve. [Answer] The usual argument that "FTL implies time travel" is based on special relativity (SR). A crucial assumption is that whatever physics governs FTL still obeys the symmetries of SR — in particular, if you can travel at some coordinate velocity in one inertial reference frame (as defined by SR), then you can travel at that velocity in *all* inertial reference frames. The way to defeat the argument is simple: don't require FTL to obey the symmetries of SR. This shouldn't be troublesome to do, since you have *already* broken the laws of SR simply by assuming tardyonic matter (i.e. you) can be accelerated to be faster than light. So you pick out a comfortable Newtonian reference frame, explain that it turns out length contraction and time dilation really is the right way to think about things after all (which is convincing, since the "absolute" rest frame is something we can now *detect* through whatever physics govern FTL), and enjoy FTL without time travel. The real problem is why you don't blow up the universe with an optic boom. [Answer] ## No [FTL inevitably leads to time travel](https://en.wikipedia.org/wiki/Faster-than-light#Superluminal_communication). > > Faster-than-light communication is, by Einstein's theory of > relativity, equivalent to time travel. According to Einstein's theory > of special relativity, what we measure as the speed of light in a > vacuum (or near vacuum) is actually the fundamental physical constant > c. This means that all inertial observers, regardless of their > relative velocity, will always measure zero-mass particles such as > photons traveling at c in a vacuum. This result means that > measurements of time and velocity in different frames are no longer > related simply by constant shifts, but are instead related by Poincaré > transformations. > > > Any form of FTL (including those mentioned in other answers) will also lead to time travel and several interesting novels by physicists like Stephen Baxter ([Manifold: Space](https://en.wikipedia.org/wiki/Manifold:_Space)) explain how they can be used in this capacity. ### Example Here's [more information both as reference](http://www.huffingtonpost.com/2013/08/26/wormhole-time-machine_n_3817232.html) and a thought exercise. Creating a "time machine" from a stable wormhole: 1. Create a stable wormhole. 2. Put one end on the Moon. 3. Put the other end in a spaceship. 4. Use it to resupply your spaceship (especially fuel and propellant). 5. Accelerate your spaceship to a very high velocity. 6. Fly your ship first away from and then back to the wormhole opening. 7. When your bring the wormhole ends back together, [time dilation](https://en.wikipedia.org/wiki/Time_dilation) will have caused time to move more slowly for the traveling end than the stationary end (the amount depends upon the particulars of your trajectory but they could be years, decades, or any amount of time "out of sync"). 8. If you enter the traveling end, you'll appear in the stationary end *before* stepping through. 9. Voila, time travel ### Video Discussion Here's a video news story discussing one [scientist's thoughts and experiment](https://www.youtube.com/watch?v=GHC8z6ULs18). ### Story trumps Science If you need a form of FTL without providing for time travel, you could assume some sort of cosmic censorship or other plot mechanism that simply prevents it. If you do need to resort to this just make your rules consistent and try to think out the first order effects and take those into account for your Universe. [Answer] If you want a story that is self consistent and realistic, but does not necessarily correspond exactly to reality, the answer is simple: ## Go back to Newtonian Physics Simply state that in your universe, Newtonian physics are in affect instead of relativity. This means no black holes or time dilation, but it does mean you can go as fast as you want. Newtonian physics is internally consistent, and works the same as our reality at slow speeds. (If you want to be nit picky, you can't technically go FTL since light is infinitely fast in a Newtonian, but the point is that there is no speed limit.) Edit: Quantum Mechanics is okay too. [Answer] Well, The [Alcubierre](http://www.andersoninstitute.com/alcubierre-warp-drive.html) drive kind of does that. The principal is simply warping space time, exactly like a worm hole, but localized and specialized. instead of changing the distance of point A to point B to almost nothing for an extended period of time like a worm hole, It does so temporarily and on a lesser scale, and only for whatever is inside its small bubble of influence. Just like with worm holes, you never go FTL, It merely alters the distance between you and your destination as you travel, so that every step you take is on compressed space time which if uncompressed can be dozens, if not hundreds. By doing so only as you travel, and undoing it right behind you, You get caught in a bubble that is unaffected by the manipulation, so time can flow roughly the same as if you are out of the bubble. At worst, you can "travel" to the future thanks to limited time dilation, but you can't go back in time because space time is allowed to expand and compress at almost any speed. The actual numbers seem to depend on where you look, but the the Universe was more than a light second big a second after the big bang, with some numbers be thousands of lightyears in some cases. As of right now, We can never reach certain galaxies simply due to the expansion of the universe making the distance between us and them [increase by more than the speed of light](http://scienceline.org/2007/07/ask-romero-speedoflight/). [Answer] Well, my solution to it is kinda simplistic, compared to some of the detailed answers that others have put into it - author fiat :D More seriously, the way I have things working, FTL travel doesn't imply time travel because the universe itself disallows it. You just can't travel back in time. No slingshots around the Sun, or emergency cold starts of the drive, or super-advanced chroniton 29th century blah blah, nothing. Everything else is like reality unless noted. If you don't particularly feel like going with that route, have FTL go through some other dimension where it's not an issue - subspace or hyperspace being the most common name for it, although you could do something really weird, like "nullspace" or "clownspace" or something. The important thing is, it's another space-time, in which stuff works differently, whether that be something about relativity, or the speed of light, or the distance between two points. For instance, hyperspace might be a place where the speed of light is infinite, or at least unreachable without months of acceleration. Or it might be a place where light-years are compressed down to mere light-minutes. Then, rather than FTL travel through normal space, ships jump over to hyperspace or whatever and just travel normally there. From the perspective of somebody in normal space, you disappear from normal space, and reappear somewhere else. From the perspective of hyperspace, you haven't done anything screwy, you have not disobeyed the physical laws of the land in the slightest. Everybody wins! [Answer] [The universe expands at a rate that is faster than light.](https://www.space.com/33306-how-does-the-universe-expand-faster-than-light.html) The whole universe would be time-travelling if any FTL thing would mean time travel. Because this is very probably not the case, then FTL without time travel should not be implausible. It is even possible that FTL travel (if you suppose it is possible) operates under the same principles that allows the universe to expand faster than light. Hence FTL might even mean that there can be no time travel at all as a consequence. [Answer] FTL does not necessitate time travel. Wormholes (Bose-Einstein bridges if you prefer the term, used in "Sliders"), as defined by Einstein and Bose were in "the quantum electrodynamics of gravity" are not violations of special relativity. They were short cuts between point A and B. You travelled this bridge at normal speeds. There is conjecture that quantum teleportation or strings seeming to be everywhere at once is just similar shortcuts/bridges/wormholes. Alcubierre's drive hoped that gravity propagated faster than light for it to work. Recent studies of colliding neutron stars have proven gravity waves have the same speed of light limit as matter and light. During the inflationary phase of the universe, time did not go backwards. The universe expanded faster than the speed of light and continued on. If your FTL somehow mimicked those conditions, I would expect a similar result. If you are traveling near the speed of light, the shortening of space and lengthening of time makes it "feel" like you are going faster than light. Someone accelerating up to C using outside stars as a measurement of velocity would, if uncorrected for relativity, think themselves going much faster than light. And, in relative time, the trip would take as short a time as if they went faster than C. It would only be when travelers compared themselves to ground clocks that the discrepancy would appear. ]

[Question] [ Your mission, whether or not you choose to accept it, is to design the perfect refuge from the zombie apocalypse. Starting assumptions and constraints: * The zombies will be slow (walking) zombies (aka *The Walking Dead* zombies) and not runners (aka *28 Days Later* zombies). * The refuge should be able to achieve self-sufficiency during or shortly after the apocalypse. * It should support a minimum of 50 people but something over 500 would be preferable. * Ratio of kids to adults is 1:3. * Zombieness is transferred by bites only. * You do not need to worry about humans attacking your perfect refuge. The question: What sort of refuge could stand up to a sustained zombie mob, keep the normal humans safe, and provide fresh food & water? * Bonus points if it's possible to build your refuge after the apocalypse starts. * Bonus points if it allows the human survivors to eliminate any zombies that come near. [Answer] Well as I see it you have two potential options. 1. Buy a Caribbean island and relax away the zombie apocalypse on the beach with rum and grass skirts. 2. Build a massive fortress. While option 1 is far and away the better choice it isn't very interesting... So. What would this fortress need? * Where? + Geographically isolated...the farther away from "civilization" the better. + Ready, internal access to clean water, either by spring or river (walls over the river with steel grates + Seaside. Zombies don't usually swim. If somehow they make it in, having docks and ships on which to escape would be good. + Arable land. You want plains or forests or both, gives you raw materials and access to natural resources. * Walls. Big, thick steel reinforced concrete walls...or stone depending on what's available. + The walls should enclose not only the living spaces but farmlands as well. + The areas near the wall should be napalmed every summer to keep plant growth down so nothing can sneak up on you + Layers. At least two layers of walls. Should zombies somehow make it into the external layer of the enclosure you can close off and survive in the inner area. * The compound. At the center of the space should be a hardened, impregnable fort. The fort should contain: + Food storage...and lots of it. Enough space to store food for at least one year, preferably two. + Living space for everyone. + Armory. You want to kill zombies, you need weapons. + Basically all other facilities to keep people alive. Medical, entertainment, kitchens...so on and so forth. So basically this: [](https://i.stack.imgur.com/dbSUw.jpg) [Answer] This is my solution, right here: [](https://i.stack.imgur.com/1ew35.jpg) Preferably in a rainy area of the country, like Seattle. But even somewhere like California, [that actually receives enough rainwater to resupply itself but throws it away with flood control](http://www.forbes.com/sites/ashoka/2015/04/15/why-does-california-let-billions-of-gallons-of-fresh-water-flow-straight-into-the-ocean/) would probably work well enough if you were willing to ration. Consider the needs: * Construction supplies for fortification and for comfortable human habitation (you are going to want a chair to sit on if you are living somewhere with a concrete floor). It goes without saying that Home Depot is already a concrete building which is fairly well fortified, but you can also make it stronger...[with what you already have in Home Depot](http://www.homedepot.com/b/Building-Materials/N-5yc1vZaqns). Plus most of them have an outdoor (but fenced in) gardening center, meaning you gain critical sunlight and land space in a protected area. * Plenty of space for exercise and survival: Home Depot Stores average [105,000 square feet](https://simple.wikipedia.org/wiki/Home_Depot). [The Massachusetts government recommends 15-20 square feet per person](http://www.mass.gov/eopss/docs/mema/emd-advisory-committee/appendix-a/american-red-cross/shelter-survey-form.doc). That's a lot of people (about 5000, which is ten times more then the max listed in the OP). * Weapon Supplies: [Some 400,000 people are sent to the ER with power tool related injuries every year.](http://www.forbes.com/2009/12/21/most-dangerous-tools-business-healthcare-tools.html) [Power nailers alone casue 37,000 of these yearly](http://www.forbes.com/2009/12/21/most-dangerous-tools-business-healthcare-tools_slide_2.html). [In 2010 there were only 73,505 non-fatal firearm injuries](http://www.politifact.com/truth-o-meter/statements/2012/jul/23/facebook-posts/do-people-get-shot-every-year-facebook-post-says/). So you've already got the gun store beat. * Power, for a while: Aisles full of batteries (including car batteries) means that you will have lights, at least, for a while. Drain the cars in the parking lot of all of their fuel...and you can power the portable generators and the power tools for a while longer then that, too. And if you find the RIGHT Home Depot...there might even be a gas station in the parking lot (this would be ideal). This will last you long enough to use the Home Depot supplies to build yourself a nice [Solar Power](http://www.homedepot.com/s/solar?NCNI-5) factory on the roof. * Food: The biggest problem is going to be food. At our lowest number of 50 people and with careful rationing, what you can find in the home depot can probably last you for a short time. But the real power of the **Home Depot Zombie Survival Center** comes from the gardening center. Not only is it stocked with seeds, but it also has some near-fully matured trees. You will be able to cultivate and grow your own crops, indoors if the climate does not permit year round growing, out doors if it does to use more of the natural sunlight and avoid having to cut holes in the roof. [Radishes, Green Onions, and Cucumbers can be harvested after just a month of a growth](http://theselfsufficientliving.com/12-fast-growing-vegetables-and-fruit-trees-for-your-home-garden/). It's getting through that first 30 days that is the challenge. After a year, you can produce fruit from all except the apple trees - and after two years, the apple trees will produce as well. And that assumes none of them are close to maturing (which some of them will be). * Water: You have hundreds of trash cans, rain barrels, wheel barrels, and the ever ubiquitous Home Depot Project bucket with which to catch rain water, and for a short time, at least, you can probably get water through the existing plumbing fixtures to build a small stock pile. Harvesting rain water should be enough to supply a 50 person 'society' with enough water to survive, again, with rationing. [Houses get around 100,000 liters a year, commercial buildings obviously more](http://www.savetherain.info/media-centre/rainwater-harvesting-faqs.aspx), and [the average adult male needs 3 liters a day to survive](http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256). At 50 people, we can meet this need annually. We actually get enough to support twice that number (Our theoretical Home Depot is 42 x the size of that house but covers about 60% more space, so probably about 160,000 liters annually). You certainly have the piping you need to be able to build a system to capture and filter the rain water, as well as plenty of pumps for moving the water around. Regarding the OP requirements: * This can stand up to the Zombie mob (and be reinforced if it starts to break down). * This can keep the normal humans safe (except for those power tool accidents) * This can provide fresh food and water * This can be established after the zombie apocalypse starts * This can achieve self-sufficency immediately if some supplies are brought for the short term and/or basic services remaining functioning long enough to stock up. * This can support 50 - 500 people, including children. * This will allow humans to build traps and arm themselves to fight off any Zombies that approach. So you can have your ancient castle - I'm sticking with the Home Depot. [Answer] This is really more of a comment, but since I was interested in sharing the picture, here is a building considered to be "the best" zombie fortress: an elevator structure over an abandoned Japanese coal mine[](https://i.stack.imgur.com/59oNO.jpg) The structure has most of the attributes of a fortress, including being strongly built, in a relatively isolated location, and has the added bonus of being on "stilts" to make it harder for zombies or other "undesirables" to enter. Being made of concrete, it is fire resistant and proof against most primitive weapons and even small arms fire. The superstructure is also large enough to hold a fairly comprehensive supply depot for the survivors, has clear fields of fire in most directions and room for a fair number of survivors (as well as room for people to get away from each other for a while, since being cooped up with people for long periods of time while under stress could lead to confrontations and fighting among the survivors). About the only weakness of the structure is the lack of water, although a fairly large collection area on the roof could be used to capture rain water and a portion of the structure could be converted into a water storage tank (or tanks, for safety) The real issue would be getting there in the first place when the zombie apocalypse happens, and being able to stockpile the place either before or during the event without either attracting the attention of people wiling to steal your stuff, or being eaten while trying to scavenge caned goods from abandoned grocery stores. You certainly could not build this *during* the zombie apocalypse, and getting a building permit in the here and now might be...problematic. [Answer] I think the best location to be during a zombie apocalypse is on a ship. Not your average yacht, but something more respectable like an aircraft carrier. Advantages of an aircraft carrier: * Although the minimum of 50 people in the question probably won't be enough to run a carrier, you don't need to worry about more people soon. For example a Nimitz class aircraft carrier has over 6000 personnel on board. * Usually zombies aren't able to swim, but maybe because of evolution and a strong desire for brains they will learn how to swim. But when they will reach the carrier they won't be able to climb on board because of the angle they need to climb (most parts more then 90 degrees), they'll simply fall of. Do remember to refrain from dropping the anchor, they might climb on board via the chain. * You're free to go wherever you want, 71% of the earth is covered by water so you can go cruising around the world if you're bored. * Many big cities are close to seas and oceans. Big cities means lots of resources. So if you're low on for example munition, clothing, spare parts, and so on you could sail to a city, get in your helicopter and scout the area where you need the resources from. If you've scouted the area, plan an expedition to retrieve the resources you need. Most likely there will be attack helicopters on a carrier so you could use those as air assistance. You're (self-trained) ground troops should be dropped by a transport helicopter, clear the area, retrieve the goods you need and ship them back with the transport helicopter. This way your carrier stays safe and the ground troops are the only ones who take risks. * Same applies to gas and oil of which you will need quite some. Although the ship is nuclear power you will need oil and gas for the operating of the ship and helicopters and so on. Most refineries are in big harbors, so you need to dock every now and then to get some fresh oil and gas. Given that the world doesn't need any gas and oil any more there should be plenty for a long time in the refineries. The ideal solution in this situation would be to find a fully loaded oil tanker somewhere and use that as gas station. * In aspect of food you need to reserve quite a lot of flight deck for growing vegetables and other plants for food. With a length of almost 1100 feet and a width of around 250 feet you will have around 275,000 square feet of deck. Let's say that you can use around 200,000 feet of it because the helicopters need to launch and you need to be able to move around. In the case of 5000 people on the carrier you would have 40 square feet per person. It's not much but with additional food scavenged from land raids and fishing you would be able to survive. And because you're on a ship you're able to sail to the perfect climate where your crops will grow the best. Although you need to get a lot of soil on the carrier first, let's say on average 2 feet deep, that means that you need 400,000 cubic feet of soil which weighs around 600 tons... * In aspect of water you would be able to turn seawater into drinking water with the equipment of the ship, so you don't have to worry about water. * For close range defense you can mount .50 machine guns all around the ship for protection during visits to dangerous places close to the coast. [Answer] When I lived on the southcoast of the UK, I had my perfect Zombie defense refuge a few miles away, in the middle of the Solent. Previously built as a defensive structure, it has been subsequently converted into a luxury hotel. An ample supply of fish around, well stocked kitchens - no zombies are getting in here! [](https://i.stack.imgur.com/0xk8m.jpg) <https://en.wikipedia.org/wiki/Spitbank_Fort> [Answer] All you need to build the perfect base (against infected) are industrial docks. [](https://i.stack.imgur.com/4YGXH.jpg) As you can see you are surrounded on three sides by water, this mean you only need to worry about the entrance which is explained lower down. You can use the water as both a drink source (combined with rain collectors) and an escape route. You can (though it's hard work) bring in soil for farm animals and crops. Now for sleeping and defense you only need the shipping crates and a crane (or strong forklift). Stack two crates for rooms; the top is for sleeping in case the perimeter is over run in also cannot be reached without a ladder or rope. and the bottom is for storage. As for defense, simply make two rows of crates against each other with the first row having another row on top of them. kind of an L shape. [](https://i.stack.imgur.com/84WO5.jpg) Like this but one block shorter. You can blowtorch doors and windows in them to make them into quick metal buildings. With enough people you can get one dock done in a week. then repeat with the other docks and connect with boats that have planks holding them up. [Answer] How long term does it really need to be? If you're in a cold enough climate they should all just freeze in the winter and rot unto uselessness during the subsequent thaw. Virtually any community above the permafrost line would carry on practically as usual in this zombie apocalypse. [Answer] Super-yacht. A super-yacht is by far the best refuge in which to weather a zombie apocalypse. Super-yachts are upwards of 150 feet long and easily sleep 50 people. But this is based on the tricky assumption that you can acquire a super-yacht before the apocalypse breaks out, or make it to, and de-zombie the super-yacht of its newly zombiefied oligarch owner, entourage, crew and dancing girls after the dead rise. Assuming that you can, you will have a great place to chill while the world tears itself apart. A super-yacht of sufficient blinginess can make its own fresh water with on board desalination and can run for months on end on the gargantuan fuel tanks - provided you don't move around too much. At anchor you would only need fuel to run the generators, not the main engines themselves, and the only weak point in your luxury fortress would be your anchor chain. Zombies can walk on the seabed and may spot the lights and hot tub antics of your crew of survivors from the shore. So you would need to be prepared in case any head over and try to climb up your anchor chain. But the larger your yacht, the more easily defensible this point will be. The chain usually enters the boat through a smallish hole some distance down the side of the hull, if this is too small for a zombie to squeeze through, your'e golden. If not, you may have to put someone on watch with a spear gun. If the chain gets swarmed, simply raise the anchor using your yacht's powerful electric windlass, the zombies will get mashed to a pulp in no time at the touch of a button. Most yachts in this category come equipped with remote controlled submersibles designed to examine the seabed for good anchor holding, (I have seen one of these first hand) so you could put your sub to good use spotting zombies. Super-yachts are by nature extremely self sufficient, and are designed to spend extended periods at sea with all mod cons. All your needs for power, light, heating, cooling, refrigeration, entertainment and ice-making would be taken care of as long as you have enough fuel to run the generators. Fuel – you would need to invest some time identifying a suitable fuel barge from which to refuel, these are often found moored near commercial shipping hubs, or deep water harbors suitable for super-yachts. Alternatively you could refuel from a fueling pontoon – in both cases you may need transfer one of your yacht's portable generators (believe me, your boat will come with everything you could want), connect up the power to the fuel pumping apparatus and fill up. Your tanks will be huge though, so this could take some time. On a pontoon you will have a single gangway ashore to defend, these are often already equipped with impregnable security gates that your determined zombie (and let's face it – there is no other kind), will find difficult, though not impossible to overcome. Not the worst situation to be in, but be prepared to beat a hasty retreat and/or defend your position with your yacht's water cannon. Food, your super-yacht will be equipped with a stunningly well appointed galley, including all electric appliances under the sun, hobs, ovens, industrial fridges and freezers to store food, either pilfered from shore or, more promisingly fished fresh from the sea. Your yacht will be equipped with all manner of fishing equipment, don't worry. So get used to living off the fruits of the sea, far easier, more nutritious and tastier than trying your hand at farming in an apocalypse, or eating army rations. Your yacht will also have a fearsome supply of booze already on board, you might want to try growing a lemon or a lime tree somewhere because what is a superyacht without sundowners? Oh, and to ward off scurvy. Piloting and communications. Superyachts are designed to be operated safely by very few personnel, everything is done at the push of a button, however it’s possible GPS would be offline during the apocalypse, although it's quite possible the that GPS satellite network would be unaffected – unknown. In any case knowing your exact position could be an issue, so I'd suggest moving the boat around as little as possible or digging out the emergency sextant (your yacht will have one), finding the relevant book in your yacht's library and learning to take star sights – it's not easy but you'll have plenty of time to figure it out. Should the apocalypse come to an end and humanity restore itself, you will have all the comms equipment on board you can shake a stick at to monitor and communicate. No chance of you missing the end of the end of the world, and staying locked up in you bunker unnecessarily. Laundry. Yes superyachts have washing machines and tumble dryers, also ironing boards and shoe polish. No need to look like a zombie if you don't have to. Maintenance. Inevitably your yacht will go wrong at some point, this might be minor, or if it's the main engine, generator or air-conditioner - major. On the plus side, superyachts are maintained to an exquisite standard by armies of engineers, technicians and deckhands in normal use, so disrepair should take a while to set in. When this happens - move to the next superyacht in the harbour, kill the zombie skipper for his keys and fire up the engines. I would suggest that St. Tropez or Monaco would be good places to do this, and preparing some sort of yacht transfer drill for your 50+ survivors will be the best way to minimize casualties. Creature comforts. This is where the superyacht approach really owns it over your disused mining structure, or underground missile silo approach. You will be sleeping in 1000 thread-count Egyptian cotton sheets, you will have a commanding view of your surroundings from your various, comfortably appointed relaxation decks, you will wash in one of many heated, lit and surround-sound equipped hot tubs, or gold encrusted bathrooms, you will have, a gym, a dining room, books, movies, music, expensive cutlery, lead crystal glassware, vintage brandy, Cuban cigars – in short, every luxury you can think of, as well of plenty you didn't even know existed. The apocalypse will be a blast. [Answer] Rural Siberia. Preferably, a small village that can only be reached by air (no roads). The locals could help newcomers survive without civilization. Even if zombies try to traverse the taiga, they are likely to break limbs when going without roads, get lost, sucked in swamps, frozen, or/and eaten by wolves or bears. (Please, disregard this answer if the bears can be infected.) [Answer] In establishing a secure location, a fortified settlement there are three basic things you need to consider: First, the **location**. Second, the **location**. And third, the **location**. The relative order of importance might vary. The location must have adequate logistics. There must be a water supply. Food must be available. This means either good transport connections or some secure farm land attached. In modern times fuel and ammunition would also be considered vital supplies. These can't be produced by opportunistic farming, so the refuge should be near a major city or a military base that has significant stores of necessities to scavenge regardless of whether it is still in operation. A military supply depot would almost by definition have everything you need to survive hostile environment. The location should have some strategic value in either operations against the enemy or preventing the enemy from operating. In context, this would mean it should have enough space for a growing number of refugees to protect from zombies and near to areas with lots of refugees and zombies. Near here means that you want an ability to conveniently go in a truck or boat, kill a horde of zombies and save some grateful maidens. (Or whatever the equivalent modern cliché is.) Ability to return from your sortie safely with the refugees would also be a must. The location should be physically secure. It should be impossible to the enemy to simply come and take the site. It should require significant preparation and concentration of force. Significant here means that defenders should have time to retreat in the time between the actual attack and noticeable preparations for attack. And yes, having a location that allows a safe retreat is a fourth aspect of **location** to consider. A location meeting the requirements would be a coastal island without significant population near a large city and a military base. Most supplies can be scavenged from mainland and transported by boat, but a water supply should be available. Fishing and gardening can supply fresh food in addition to scavenged food. Similarly since zombies are not really interested in vegetables, other islands and even the mainland can be farmed. Farmlands tend to be open enough for reasonable safety. Coastal cities and bases can be assumed to have support for water transport, so as long as you have boats logistics would be secure. Slow zombies have no real way of stopping boats, so you would have ability to kill zombies and rescue survivors near the coast with minimal risk. Generally slow zombies are presumed to be attracted to human activity by scent and noise, and to have no survival instinct worth mentioning. Thus they would be attracted to the coast by all the activity and you would be able to shoot them safely from boat. Daily "clearing" sorties should have the nearby areas clear from zombies to the point that scavenging parties sent to raid storage facilities and supply depots would face minimal risk. Most zombie apocalypse survivors would be paranoid enough to handle such risks without issues. Unless zombies can operate boats or ships, they should be incapable of the coordination needed to cross significant bodies of water with significant waves and currents. The exception is if they have magic lifesense that allows them to home on to live humans without needing to scent or hear them. You will still need to guard the shores for floaters. Some dogs, electric lights, and few people with shotguns should cover that. Motion sensors and such are of course available and can be looted from stores. And some beaches could be simply mined, if the country the base belongs to still stocks infantry mines. An island with sufficient boats (and you can and should gather all you find) can be evacuated without the zombies being able to even slow it down. The solutions for inland and metropolitan areas are obviously different, but they are not as good, so not relevant to the question. [Answer] This is a slight variant on the "Caribbean Island" theme. The problem with this is solution is that currents may bring to your island a random zombie. After 50 years spent far from the world, you are not prepared to deal with it. A possibly better solution is to find an island **on a river.** This has a few additional benefits: * By staying close to the threat, you are effectively keeping yourself sharp. Of course fortifying the island is a good idea in order to avoid washed-up zombies, however you can still keep a small port downstream. The more current there is around your island, the less likely it is for a zombie to manage to cross it. * Freshwater is always a good thing to have, and makes for easier irrigation. Also running water is a good sewer-system to avoid your population catching diseases. Also something along the lines of water-mills could allow you to keep making some electricity. * The best ways to get on land would be either by boat or using draw-bridges, and the usual tricks from the middle age would make good additional securities. * Rivers are a great way to move over large distances, making it easier to find resources and/or other survivors * Finally, by staying close to land, it is easier to drive back the zombies and expand your territory. [Answer] ## Electric fences In many ways, zombies are roughly similar to triffids from John Wyndham's [*Day of the Triffids*](https://en.wikipedia.org/wiki/The_Day_of_the_Triffids): they are slow-moving, tenacious, not very intelligent, but will kill you if they get near you. Towards the end of this book, the protagonists create a safe enclosure for themselves in a cottage in the South Downs. Their main defence against triffids is an **electric fence**, sufficiently high and well-wired that it's impossible to get over or through and sufficiently powerful to knock triffids/zombies flying. Advantages: * It can be powered by a home generator, e.g. by solar or wind power, so no mains electricity needed. * It can surround a *large* area of land, so you can grow your own food and have a small self-sufficient colony within the protected region. Disadvantages: * It takes time to set up. * It needs to be constantly patrolled for any sign of damage to the fence: if those wires give way, you're screwed! [Answer] To keep out zombies with mere walls you need some pretty tall walls. Think of the scene in World War Z where the Israeli defenses are breached--the zombies know there are brains on the other side of the wall, they blindly keep coming, climbing upon each other. (The movie got it wrong, though, it wouldn't be cooperative pyramids, just a mass.) Given enough zombies they can climb quite a wall. Thus walls are far from an optimum defense. Instead, consider a star fort. When the zombies encounter the fort they'll proceed along the walls (doing so moves them closer to the brains inside) and come to the junctions. At each entrance place a tunnel--the tunnel has a floor that will drop away 1 second after a load is placed on it. The zombie falls down into something you have devised to be lethal to zombies--say, a giant-size wood chipper. [Answer] Just pick a regular set of farmland and town. Then you build zombie traps around it, out of sight/hearing from your settlement. Zombies are really stupid, so this would just need to be something like a cattle pen. You have a minimally fortified central 'bait' area where humans make noise, emit odors, generally attract the walkers. They drive themselves into chutes, and are stopped by a nice fence from reaching the bait. But being zombies, they just sit there, so small groups in sealed shelters come out behind and drop a gate behind. Exterminate the Zs from a safe distance, rinse and repeat. Eventually there won't be any left in the area. [Answer] # Get your group to [Mammoth Cave](https://en.wikipedia.org/wiki/Mammoth_Cave_National_Park) Or any number of popular cave/cavern destinations. If you happen to be in Central Kentucky, Mammoth Cave would be ideal. ### Survival: short-term If you are already near a popular cave tourist destination, chances are there are going to be plenty of supplies in the nearby town, not to mention everything that is already on-site: food, clean water, camping gear, rope, lanterns, etc. Also, any cave entrances will probably already be secured by whatever park service ran the cave operation. Take as much gear and supplies as you can inside the cave, and barricade yourself in. ### Survival: middle-term Tourism caves are already wired for electricity and lighting. With any luck, the power grid is still active when you show up. Otherwise, there should be backup power generators on-site. Either way, you'll need power. Make sure the generators have enough fuel to last a while. When your jerky and Twinkies start running out, you're going to have to think of a better way to get calories. There may be some edible [troglobites](https://en.wikipedia.org/wiki/List_of_troglobites) with you in the cave. If there is an underground river (ideal!), you might have some cave fish you can eat. Growing mushrooms is another obvious choice. Every tourist cavern I've been to has some kind of underground water system, whether groundwater that drips and collects in pools (after all, this is how stalagmites and stalactites are formed), or a full-fledged underground river system. Maybe the cave entrance is only accessible from underwater. That'd be pretty cool. But regardless, you should have access to water. Fresh air shouldn't be a problem. I don't know if popular cave destinations already have circulation systems, but even if they don't, there are likely several small holes that lead back above ground. That's how all those bats are still hanging around with you. ### Survival: long-term Okay, now you're going to have to think about some sustainable underground agriculture. Mushrooms, cave fish, and bugs aren't going to be enough. You also will need a way to make sure the lights stay on. You can't count on diesel forever. I see a couple of options for power: geothermal or hydroelectric (if you have a waterfall or river to work with). I hope you have some [smart people](http://img1.wikia.nocookie.net/__cb20141111011307/walkingdead/images/0/04/505_Eugene_Explaining.png) in your group to help you set this up. With lights, you can grow other crops underground. Potatoes, other root vegetables, and legumes are good bets. You also have probably been digging. Carefully, you should be able to punch small holes through the surface, for some extra lighting and air. If you can get your hands on it, large metal grates would be awesome, or some thick plexiglass for your roof. Then you'd be a lot less dependent on electricity. ### Bonus If you chose a [pit cave](https://en.wikipedia.org/wiki/Pit_cave), then awesome! Likely the only way up and down is a rope or ladder - something zombies aren't going to be able to manage. If you don't have a pit, you could probably dig one out eventually. This is good and bad. Good thing is, in manageable quantities, zombies falling into your pit is an awesome way to take them out. If they aren't killed by the fall, you can have some zombie finishers guarding the bottom of the pit. If they aren't magically poisonous, their bodies would provide some excellent biomass for mushrooms and such. Otherwise, you'd have to burn them or dispose of them some other way. Bad thing is, if a massive horde comes your way, then you might be screwed. My vision of the pit is just a straight shaft in the ground, and at the bottom, a single door to the rest of the complex. If the zombies come raining down uncontrollably, you can bar the door and let them pile up. Your door is probably fine, as most of the zombies will be incapacitated from the fall, and then you'll eventually have so many zombies that none of them will be able to get through the door. After the pit is filled up? I'm sure you can find some creative way to deal with them. You should still be safe. [Answer] Location: A farm near a river with a natural or manmade stream coming into the farm and irrigating the crops as well as providing drinking water. Should be a place with plenty of wind Energy: Large wind turbines and solar panels across the area. Security: high walls around the whole area, with deep ditches dug on the outside which are 30 feet or more deep and 15-20 feet wide. cut down all the trees near the ditches so that none accidentally falls and creates a bridge. all the walls have outward facing fans with sharp blades for fins which run on the electricity from the wind mills and solar panels. these will defend against any zombie that reaches the wall although we have made sure they cant, doesn't hurt to be safer. Feed the batteries with a turbine running on the river water as well. Can't hurt to have more electricity. The farm will produce food, we have water, energy, defence. [Answer] Location - Prison * Dictator - In charge when needed. * Survival Teacher - in charge of survival training and ammo manufacturing trips * Council - In charge when there's no major threats. Council members are each a leader of a certain "category" of jobs. * Head Doctor - in charge of health * Head Farmer - in charge of farming and livestock * Head Whisperer - in charge of supply runs * Head Security - in charge of guards, fence cleaners and regulators * Rationer - in charge of rationing and cooks * Architect - in charge of design and construction Jobs - * Guard Watch for threats in guard tower and walk perimeter looking for weak spots, if weak spots found they report to head of security which is then reported to the architect * Fence Cleaner Kill walkers pushing against chain-link * Farmer Plant, nurture and harvest the crops and tend to the livestock * Supply Runner aka Whisperer You can only become a whisperer with they blessing of the survival teacher. A whisperer travels beyond the wall to gather supplies. They wear mask made from walkers as camo and when traveling in a walker herd they communicate by whispering * Regulator The "peace keepers" of the settlement regulate arguments and fights, they tend to have good showmanship to keep things happy but if they cant settle a fight they bring the people to the fight pit to settle it. * Cook A cook is given the daily rations and after cooking they feed the people and make sure no one gets extra because there only given the exact amount for everyone * Survival Teacher The survival teacher is the best survivalist and battle strategist. There jobs to teach a daily class. The teacher is the only person with the power to approve someone of becoming a whisperer which is only given after completion of all survival classes. In times of crisis the survival teacher steps in for the council as dictator * Doctor Tends to wounds and illnesses * Rationer In charge of rationing all supplies and mainly works with whisperers * Construction Builds the architects designs * Architect Knows a lot about construction and thinks of new ways to improve the settlements defenses * Bullet Manufacturer Travels to ammo factory once a month with advanced survival class students, survival teacher and some guards Activities - * Library Abundance of both entertaining and educational books that were in the prison and scavenged by whisperers * Fighting Pit Used for either settling fights, teaching students or entertainment. When used for class or thrill there's walkers on chains surrounding the pit (secretly there teeth and nails had been removed). * Survival Class you spend time helping with crops, going to the library to read educational books, training to kill walkers in the fighting/melee pit, learn ammo manufacturing, how to use and clean a gun and helping in the med ward [Answer] You just need one of the fortified islands from the South China Sea. They have battleships (assuming your survivors know how to operate one). They also have guns and electricity making stuff and the zombies can't get to it because it is in the middle of the ocean. [Answer] What you want is a lagoon, one surrounded by mountains on three sides. Basically, you take a location that already exists and start fixing it up. The lagoon's water will be blocked off from the ocean by "a reef or low sandbank"; that's not good enough. You need to keep zombies out of your lagoon, period, so install a metal fence or a stone wall to keep them out. You'll probably want to shear the outward sides of your mountains, to make them too steep for zombies to climb. On the beach, you'll need to place a water purification facility, farms, and everything you'll need to survive. If the apocalypse has already happened, this lagoon is *still* a good option. Walker by definition are shambling corpses; I'd guess the odds of them going up the mountains without being taken out of commission by the journey itself at a 100 to 1. Spikes, pit traps, and deadfalls will work wonders on the mountain slopes. The natural barriers of the lagoon will help stop seabed-walking zombies, but for best results, you'll need to put down a different kind of barriers. A brick wall, fence, or even just heaps of rocks will do it for you. For this to work, however, you'll need to be able to protect your crops from the salt spray (walls really are essential) and either a spring or a water-purification system. That being said, this makes the cushy island lifestyle possible, but with just enough uncertainty that your apocalypse survivors can't (or *won't*) allow themselves to go soft. [Answer] # How about an abbey? [](https://en.wikipedia.org/wiki/Praglia_Abbey) Completely self-sufficient places. I would personally prefer [Redwall](http://redwall.wikia.com/wiki/Redwall_Abbey), but considering that it doesn't exist, and it designed for mouses... It doesn't takes too much effort to rebuild this place into a fort, just place the fences in between the trees. Note: this place was large enough to be used as barracks. And as you can see, it's reichdiculously easy to spot slow zombies from the bell tower. # Bonus point: [](https://i.stack.imgur.com/tINJZm.jpg) "I was an adventurer just like you, until I took an arrow into the knee." I get that ~~Americans are gun crazy~~, but as chainsaws run out of fuel, so do guns from munition. You don't have to face this problem if you're able to create more. --- # Other possible shelter locations: * The Pirate Bay's servers. * My school. seriously, it has a metric ton of computers, an effective moat, you just need to fill it with water. The place is large and is like a maze, also there are doors of unknown function, that are iron, and can be moved over the normal door, and then be locked. The place has Wi-Fi and a LAN network, and a machine that can create (possibly) swords for us from larger metal pieces. * A castle. * Far away from anything, [Hungary's most abandoned places](https://www.youtube.com/watch?v=fT5jw_H6K60) are too freaky, even for the zombies to enter. (Yes, welcome to hell, we accept payment in paper or plastic.) ]

[Question] [ Linked but not a duplicate of [this question.](https://worldbuilding.stackexchange.com/questions/14709/how-would-advanced-aliens-protect-themselves-from-idiots-with-ftl) # An example of the problem During the last Star-Wars movie, I was dumbfounded by the sheer stupidity of admiral Holdo's move, during this particularly visual scene: [](https://i.stack.imgur.com/PPtjs.jpg) While most people I know don't seem to realize how incredibly reckless this was, I'd like to offer one of my favorite quotes ever to summarize the situation: > > Gunnery Chief: This, recruits, is a 20-kilo ferrous slug. Feel the > weight. Every five seconds, the main gun of an Everest-class > dreadnought accelerates one to 1.3 percent of light speed. It impacts > with the force of a 38-kiloton bomb. That is three times the yield of > the city buster dropped on Hiroshima back on Earth. That means Sir > Isaac Newton is the deadliest son-of-a-bitch in space. Now! Serviceman > Burnside! What is Newton's First Law? > > > First Recruit: Sir! An object in motion stays in motion, sir! > > > Gunnery Chief: No credit for partial answers, maggot! > > > First Recruit: Sir! Unless acted on by an outside force, sir! > > > Gunnery Chief: Damn straight! I dare to assume you ignorant jackasses > know that space is empty. Once you fire this husk of metal, it keeps > going till it hits something. That can be a ship, or the planet behind > that ship. It might go off into deep space and hit somebody else in > ten thousand years. **If you pull the trigger on this, you're ruining > someone's day, somewhere and sometime.** That is why you check your damn > targets! That is why you wait for the computer to give you a damn > firing solution! That is why, Serviceman Chung, we do not "eyeball > it!" This is a weapon of mass destruction. You are not a cowboy > shooting from the hip! > > > Second Recruit: Sir, yes sir! > > > (Emphasis mine - quote from an anonymous human military on the Citadel in Mass Effect 2) So, for those who've been sleeping in the back of the classroom during their physics class, Holdo accelerating a ship at a speed faster than light and ramming it into another ship is the equivalent of a **cosmic shotgun**. (Hence the pretty little light streaks scattering in a cone from the impact point and instantly destroying Star Destroyers). A single bolt of 1g from this ship now has a bare minimum kinetic energy of $E = 0.5 \times m \times C^2 = 0.5 \times 0.001 \times 9 \times 10^{16} = 4.5 \times 10^{13} J$. 1 (A kiloton is $4,184 \times 10^{12} J$, so the absolute minimum energy on impact, if physics didn't break at that point, as explained in comment is around 10 kilotons. Hiroshima's *Little Boy* was estimated between 12 and 15 kilotons). To be honest, I'm not even sure this law holds at speeds higher than light, and I don't have the theoretical knowledge to even make an educated guess. Given that some several-years travel at the speed of light could be done in mere hours in the SW universe, I'd posit that those numbers are way higher, and each bolt (not even talking about chunks of the ship) are now delayed orbital strikes aiming god knows where. At this point, you might as well charge the Rebellion for crime against the universe. No wonder why the Yuuzhan-Vongs paid us a visit. # Problem The other question explains perfectly the problem. As soon as your universe includes FTL travel, an idiot somewhere is gonna make this mistake (on purpose or not) and a lot of people are gonna pay for it. Following the example above, I struggle to create any universe with FTL travel, because each war would mean I'd have to wipe half of the celestial map. A few propositions to protect a planet or a system from this kind of incident includes: giving the person using FTL the means to avoid said incident, trusting them to understand the risks, pre-emptive strike, or (my favorite) clouds of space dust. Now, the two first answers are made irrelevant by idiocy. Holdo knew the risks and had the computers telling her not to do it. By hubris, despair or idiocy, someone in a space battle will end up pushing the red button. (You don't even have to sacrifice a pilot. Guided FTL rockets are the end-game) Pre-emptive strike seems a bit radical. While they're targeted and shouldn't cause collateral damage, you can't just destroy every planet where FTL "might" happen. The cloud of dust is useful to protect a single system or planet, but there is no way to effectively shield the universe, unless you want to fill all empty space with space dust. **Is there any way to devise a universe with FTL travel without realistically condemning half of said universe to utter destruction by FTL strikes?** (Not asking how to shield a sole planet / a sole civilisation from a dumb accident) * Note that any reactionary counter measure suggests you know that a danger is coming your way. The problem of FTL is that the danger travels faster than the information. You'll "see" the explosion way after the upper deck of the destroyer tore through your planet. And the one behind. And the one behind the one behind. (But maybe quantum entanglement can help. I've read somewhere about research being done on the topic to communicate faster than light, but I don't understand the principle behind it). * To clarify what I'm asking for, I'm looking for references of universes with non-destructive faster than light space-travel, effective countermeasures covering the universe, or anything that allows you to write a story including both FTL and idiots without dramatic consequences. 1 Fixed thanks to elPolloLoco's answer. Don't do maths absent-mindedly during lunch break without double checking the data. [Answer] But in most stories, FTL doesn't actually follow Newton's 1st law; everybody knows that once your hyperdrive fails, you're dead in the water. Otherwise, the Enterprise could hit warp 9.9 and easily coast across the galaxy. And that actually makes sense in the warp-style of FTL: **FTL travel is only possible within the field generated by a functioning FTL drive.** In fact, within the reference frame of that field, matter still isn't moving faster than light! Once the drive is destroyed, the field collapses and that matter resumes its non-FTL velocity. But regardless, there are many other FTL concepts that operate completely differently. See [Hyperspace](https://en.wikipedia.org/wiki/Hyperspace), [Jump drives](https://en.wikipedia.org/wiki/Teleportation_in_fiction), [Jumpgates](https://en.wikipedia.org/wiki/Wormholes_in_fiction), and more in Wikipedia's scifi section. [Answer] # 1. Space is mostly empty > > If you pull the trigger on this, you're ruining someone's day, somewhere and sometime > > > Well, not necessarily. There's so much empty space between anything interesting in the universe, that it's very likely that those "shots from a cosmic shotgun" will just keep traveling through the cosmic void, never even approaching anything worth considering. Additionally (as @DanDryant pointed out), objects traveling faster than the speed of light can escape any gravity well, and their trajectories wouldn't even change much when passing through one. This means that superluminal objects are *less* of a risk compared to "slow" moving objects - the first need a direct hit on their first and single pass through a system, while the latter can get caught in the gravity well - going around and around, increasing their odds of hitting the massive object in its center or some other objects caught in that well. If you are specifically worried about space battles, where missing the tiny enemy fighter ships can mean bombarding the planet you are defending (or its sun!), just have these battles typically occurring far away from planets. From a worldbuilder's perspective, you can achieve this by two different strategies, used independently or combined: ## 2. Defensive technologies or circumstances Intelligent races will just have to invent and deploy defensive technologies to survive the "superluminal idiots" of the universe. Just as the Chinese Empire built [The Great Wall of China](https://en.wikipedia.org/wiki/Great_Wall_of_China) to surround their entire territory. Any FTL capable civilization will need some sort of defense: * Planetary shields that block, disintegrate or teleport any unauthorized/unexpected approaching objects. * Scattering artificial "cosmic dust" / interceptor drones / etc. around important systems / sites / stations - anything that can absorb or dampen FTL projectiles. * Planetary or system-wide [Warp Inhibitors](https://strategywiki.org/wiki/Master_of_Orion_II:_Battle_at_Antares/Force_Fields#2000_RP:_Warp_Fields), slowing down anything (or anything unauthorized) traveling towards it. * Strategic positions (inside nebulae, next to black holes etc. etc.) making any FTL dangerous - these can help even non star faring races to survive. ## 3. Limitations or variants on real-space FTL As the worldbuilder, you can tweak physics or the nature of FTL so it is more difficult to weaponize, at least against settled planets: * **No FTL next to gravity wells** - this was used widely in Larry Niven's [Known Space](https://en.wikipedia.org/wiki/Known_Space#Hyperdrive) universe. FTL only works on relatively "flat" space - forcing space battles to commence at civilized speeds or far away from solar systems. * FTL is **warp based** rather than simply traveling very fast in real-space (that's the gist of Boomchuck's [answer](https://worldbuilding.stackexchange.com/a/138570/756)). This provides ships the ability to travel astronomical distances in reasonable time without gaining an insane amount of kinetic energy. It also means that debris of an FTL collision won't be traveling at superluminal speeds (though they can still be dangerously fast...). A typical trope of this approach demands an intact "warp bubble" around the FTL ship - which is dispersed if it interacts with another bubble (and or gravity wells etc.). * FTL is **teleportation based**. Your interstellar civilizations use stargates or hyper-jumps to skip from A to B without traversing the distance between them. * FTL is done in **Hyper space** rather than real space - a ship slips to another dimension, where it cannot interact with anything in *this* dimension, and where the physics are different to allow fast traveling (or distances are different there - same thing really). Ships may each have their own exclusive variant dimension, or they may interact with other hyperspace travelers (possibly only using a compatible technology / frequency etc.). etc. etc. etc. Finally, keep in mind the principle sometimes called [the Kzinti Lesson](http://www.larryniven.net/kzin/worlds.shtml): > > "A reaction drive's efficiency as a weapon is in direct proportion to its efficiency as a drive." > > > If you have a functional interstellar drive, it will be very difficult to completely prevent its weaponization. Atomic Rockets have an entry about [propulsion systems](http://www.projectrho.com/public_html/rocket/spacegunexotic.php#id--Propulsion_Systems) in their exotic weapons page - it's really worth reading. [Answer] First of all, this is wrong: "A single bolt of 1g from this ship now has a bare minimum kinetic energy: $$E = m \times C^2 = 0.001 \times 9 \times 10^6 = 9 \times 10^3 J$$ Kinetic energy is calculated as $0.5mv^2$ $v$ being $c = (3 \times 10^8) v^2 = 9 \times 10^{16}$ So you get $$E = (10^{-3}) \times 9 \times (10^{16}) \times 0.5 = 4.5 \times (10^{13}) J$$ But it doesn't really matter does it? Now here is the thing: This formula is not suited for speed close to $c$. That is because close to the speed of light, the mass of the object changes.[Edit: the mass of the object does not change, the formula is still useless at speeds close to c, reasons to be found in comments] Maybe you once heard that it takes an infinite amount of energy to bring an object with mass to the speed of light? Using this formula, it wouldn't. Now let's get to your problem. Obviously having all kind of people flying WMDs is kind of problematic and wouldn't do the galaxy any good. FTL by just flying really fast is already a violation of physics, so just leave it out. You need your characters to be able to move between starsystems or even galaxies in little time? Give them some kind of warp- engine or wormholes or some other magic travelling aid that moves them from A to B without accelerating them and so without putting insane amounts of energy into them. Edit: See the Ender series for example. I think FTL is introduced in "speaker of the dead" or "Ender in exile". [Answer] > > Is there any way to devise a universe with FTL travel without realistically condemning half of said universe to utter destruction by FTL strikes? > > > My personal favorite answer to this is E.E. "Doc" Smith's FTL approach from the *Lensman* series: Inertialess drives. Basically, you turn the inertialess drive on and immediately assume the velocity at which all forces acting on your ship cancel each other out. If you have a reasonably-powerful engine pushing in one direction, this will mean moving at an extremely high multiple of the speed of light, because that's what it will take for the drag from interstellar gases to match the power of your engine. But, if you run into a planet, you stop instantly with no impact effect, because the resistive force of the planet is enough to cancel out your engine's thrust. This also makes most projectile or energy weapons useless when used from a lone attacker, as the impact of the attacker's guns or the light pressure of their lasers will simply push the defender away with no damage inflicted. The only effective means of space combat is for large fleets to form up as cylinders, cones, or spheres around the enemy and crush them with simultaneous weapons fire from all directions. When the inertialess drive is turned off, you will immediately resume your original vector. Although this eliminates the problems of superluminal impacts and accidental planetary devastation, it still allows for deliberate planet-killer attacks, such as finding another planet moving on the opposite vector, taking it inertialess, and inserting it into the target world's orbit. The kinetic energy of a 20kg slug at 0.13c is peanuts compared to a head-on collision between two planets at typical orbital velocities. And, if that's not destructive enough, in the later books of the series, they start finding antimatter planets to do this with because, sometimes, there's no such thing as too much overkill. [Answer] # Kinetic Energy at High Velocities If you design a universe that permits faster than light travel, you will need to invent laws for how kinetic energy works when traveling faster than light. For centuries, we used the Newtonian formula for kinetic energy: $KE = \frac{m v^2}{2}$. And that worked well. It isn't *wrong*; it's just an approximation that only holds for velocities well below the speed of light. But for high velocities, we need to use Einstein's version instead: $KE = \frac{m c^2}{\sqrt{1 - v^2/c^2}} - m c^2$. (m is the rest mass in that formula, not the relative mass.) We *could* also use this for low velocities if we wanted to; it's approximately equal to $\frac{m v^2}{2} + \frac{3m}{8}\frac{v^4}{c^2} + \frac{6m}{16}\frac{v^6}{c^4} + ...$, so all terms except $\frac{m v^2}{2}$ will be very close to zero. But for that same reason, we don't need to bother with any term except the first when $v << c$, so it'd be overkill. We instead use the simplest approximation that works well at the sort of speeds we're looking at. --- Now let's look at what those equations mean in practice. Suppose we have a 1 kg mass and see how much energy these predict at various speeds. ## Low speed: 10 m/s If it's moving at 10 m/s, then using the Newtonian approximation, we get a kinetic energy of $50 J$. If we use the Einsteinian version, we get $50.00000000028 J$. Both versions are exceedingly accurate, and so we might as well use the simpler one. ## Relativistic speed: 0.99c The Newtonian approximation gives us $3.64 \times 10^{16} J$. The Einsteinian one gives us $2.58 \times 10^{17} J$. The Newtonian version is eight times too small; at these velocities, we can no longer use that approximation. ## FTL speed: 2c The Newtonian approximation gives $1.8 \times 10^{17} J$, but we don't care because we've long since passed the velocities where it's remotely accurate. The Einsteinian approximation gives us $-1.038\;i \times 10^{17} J$. Since our kinetic energy is now both negative and imaginary, it's safe to say that this approximation is no longer accurate (or even meaningful) at faster than light velocities. (It's not even *defined* at exactly light speed; there's a division by 0.) --- In our universe, the Einsteinian equation may not *be* an approximation; it may be completely accurate at all velocities for all we know. But if FTL is possible in your universe, than it *must* be an approximation that is only valid at low speeds. I can't tell you what equation you should use for calculating kinetic energy at FTL speeds; I can just say that the one you're using will not give accurate results in our universe, and the best approximation known to modern science for our universe doesn't even permit FTL, so that won't be right, either. Decide how you *want* kinetic energy to work at FTL speeds, and then be consistent. # Energy Scale You don't actually have to make up a new equation if you don't want to, though. You can safely assume that Newtonian physics hold at any velocity in your universe without creating the sort of problems that you're envisioning. $10^{13} J$ may sound like a lot, but that's by puny Earthling standards. We've tested nukes that are [20,000 times larger than that](https://en.wikipedia.org/wiki/Tsar_Bomba), and we're all still here. Let's consider something with a bit more energy than a mere hydrogen bomb. Suppose that Newtonian physics holds at high speed, and that we've got a ship the size of the [Titanic](https://en.wikipedia.org/wiki/RMS_Titanic) moving at light speed. It would have a kinetic energy of $2.337 \times 10^{24} J$. That's a decent amount of energy, but it's 100 times less than the Sun outputs [every second](https://en.wikipedia.org/wiki/Sun#Core), and 100 *million* times less than what we'd need to [blow up the Earth](https://qntm.org/data). (Which in turn means that the scene you mention was *not* the [most energetic event](https://www.starwars.com/databank/alderaan) we've seen in Star Wars.) To put things into *serious* perspective, a [supernova](http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/snovcn.html) can output $10^{44} J$. That's $10^{20}$ times more than our ship's kinetic energy. [Which is to say](https://xkcd.com/1162/), our ship colliding with something outputs at least 100,000,000,000,000,000,000 times less energy than something that happens in the universe on a fairly regular basis. [Answer] # **Drag** Space is big and very very empty... but it isn't *totally* empty. There is a fine mist of dust and gas and atoms between the stars. It's not much. The cold depths of interstellar space have a purer vacuum than almost anything you'll find in a lab on earth. But if you go **fast enough** it really matters. In the solar system with the solar wind the density of atoms is 2x10^7 per cubic meter, mostly hydrogen or helium. Outside the solar system it varies quit a bit by temperature and charge but if you take a steel ball and throw it into the cold dark night... # Lets see what happens if you hit something, easy (scaled down to keep the photographer alive) [](https://i.stack.imgur.com/KmfJN.jpg) But what if you miss... The 20-kilo ferrous slug leaves the ships railgun at 1.3% of the speed of light. The slug is pure iron. The sphere has a radius of 8.464 centimeters. [](https://i.stack.imgur.com/wUfol.jpg) It's going at 1.3% of the speed of light so lets wait about 1.3 light years away and see what it looks like when it arrives. # Hmm. It's a little bit late... not very late but a little bit... In order to reach us the sphere has had to pass through 2.768×10^20 cubic centimeters of "empty" space A Cold Neutral Medium (CNM) in interstellar space has about 20-50 atoms per cubic cm mostly hydrogen or helium. We'll assume 25 hydrogen atoms per cm^3 to make this easier. So while it's traveled it's hit (2.768×10^20 \*25) atoms of hydrogen... about 11.58 mg (milligrams) of hydrogen. Assuming it doesn't hit a grain of sand long the way and turn itself into a cloud of atoms. That's not a lot... but by the time the slug has traveled 2,245,230 light years it's struck about 20kg of hydrogen atoms. Notice that that's it's own weight in hydrogen. That's a long way, almost the distance to Andromeda. So by then it's going *about* half it's original speed and some of the iron has likely ablated away from those little impacts. The universe doesn't fill up with high speed debris because every piece of debris experiences a tiny and subtle drag from hitting the fine mist of atoms between the stars. [Answer] tl;wr: Based on Star Wars canon: Gravity sucks you out of hyperspace. --- At least in the written Star Wars universe it is canon, that while you may travel faster than light (no details known on how that works), ships can not fly through gravity wells. Meaning, before a ship travelling FTL hits a sun or a planet, it gets sucked out of hyperspace and has to travel STL. The same should go for any matter/particles/shipwreck parts which are propelled to FTL by any possible freak "accident". Ships are usually not large enough to generate a gravitic field of their own, so basically after disabling all security measures etc. Admiral Holdo would have been able to execute the pictured manoeuvre, resulting in an at least close-to-lightspeed blast of shrapnels, shredding half of the fleet. And while that shrapnels may race through space for a very long time and distance, at least planets are rather safe from them, due to their solar systems gravity wells. Any debris would slow down to anything STL and at least partially burn in the atmosphere. Sure, there could still be some damage, but the total number of freak accidents and thus shrapnels is to be estimated rather small. The lone ship in space could get unlucky though, to be honest. --- Thought on the side: It would be interesting to know, whether the Death Stars were massive enough to create their own gravity field. --- The movies are - sadly - another topic. At least in Episode VII Disney wrecked the canon when the Millenium Falcon travelled through hyperspace right above the surface of Starkiller Base, below its energy shields. A jump actually impossible since the gravity should have sucked the Falcon out of hyperspace long before it got there. I can't cite numbers here, but I estimate that, when it comes to planets you have to be at least in a geostationary orbit or higher in order to be able to jump into hyperspace - meaning, you'd be about the same distance from the planet, when you get sucked out of hyperspace. Suns are even another topic, since they are even more massive and have very large gravity wells. E.g. in either one of the Thrawn Trilogy books or one of the X-Wing-series books a New Republic spy with an Imperial background gets kind of pressed back into Imperial service, placing them on the command ship of either Thrawn or an Imperial Warlord. They manage to delete some navigational data, leading to the Star Destroyer being sucked out of hyperspace by a suns' gravity and stranding the ship effectively for several hours or even days, throwing off the imperial time plan and thus saving the day. Also Grand Admiral Thrawn himself makes very good use of the few "Interdictor" ships he controls. Those are star destroyers equipped with powerful gravity well projectors, able to pull ships from hyperspace. Sure, you have to know where the enemy will pass through, but the man was brilliant and thus several times trapped unprepared New Republic convoys or whole fleets right before the guns of his fleet, the most prominent - and also last - example being the battle of Bilbringi, during which Thrawn is murdered by one of his alien bodyguards. [Answer] ## It's not "faster than light", it's "shorter than space" If your FtL drive functions by moving your ship outside of normal space, and then back into normal space some distance away, then countermeasures are easy: any device that prevents reentry into normal space makes that space impregnable to FtL intrusion. ## [Schlock Mercenary](https://www.schlockmercenary.com/) In the earliest days of the comic, FtL travel was done using [Wormgates](https://www.schlockmercenary.com/2000-10-01) - enormous portals that ships could move between instantaneously. In this case, the energy cost of wormholes increased exponentially with the size of the wormhole, meaning that any wormhole large enough to transport a ship required its own infrastructure - hence the wormgates. Then the protagonists invented a new FtL system called the [teraport](https://www.schlockmercenary.com/2000-07-10). It functions by creating a ridiculous number of tiny wormholes, and then pushing an object's individual molecules through the wormholes and reassembling them on the other side. (Hence the name '~~tear-apart~~' 'teraport'). Because of the way the energy costs scaled, the teraport was extremely energy-efficient compared to a wormgate, and a device capable of teraporting a person could be held in your hand. This immediately revolutionized warfare, because it turns out that [being able to drop a bomb anywhere you want on your enemy's ship](https://www.schlockmercenary.com/2002-03-07) (or house) makes a battle *very* short. Of course, they can do the same... The Teraport Wars came to an end with the invention of Teraport Area Denial, which projects a field which prevents the opening of the tiny wormholes that the teraport uses. (higher energy wormholes can punch through a TAD field, but the whole reason the teraport is usable is because of how low energy the individual wormholes are). And since the teraport process requires ripping the objects being moved into infinitesimal chunks and then reassembling them, interrupting the process can be rather messy for those involved. [Answer] Independently of all the in-universe specific scenarios described and calculated so far, I think in any setup where your technology allows you to accelerate matter close to c (or above) in normal space, you will have the rough equivalent to today's landmine and explosives disposal units. Your rookie Gunner shot the Everest main gun by mistake? Call in the Sweepers ! They will calculate the round's position in normal space and, while you slap the Gunner, will move to intercept and dispose of the round diligently with means appropiate to the technological background of your Universe. For Mass Effect, that would actually include calculating the Gate it is going to be closest to for practical interception and schedule it for sometime in a few decades. For Niven's Known Space, you can be much more accurate and intercept inside Oort's cloud in hours or days. Say you had a mayor battle with lots of potential debris and lost rounds. Sweepers of winning faction will calculate where the spherical front of debris and rounds is, based on used weapons known speed, the sectors of the sphere posing a risk to the elliptical plane of nearby populated stars, and setup clean up patrols spanning for years or decades. Would not be too different from the efforts to clean up the Zone Rouge in France post WWI. You do not need to clean up the whole expanding sphere, just the parts heading to known settelments, the rest can be integrated in navigational charts with big red signs "Everest rounds on the loose. Drop off to normal space at your own risk". To deal with unreported accidents, the odd Evil Scientist, and forgotten civilization's debris from centuries ago, you will have to trust in local defense measures with integrated protocols to deal with incoming garbage at c speed as pointed in answers above. Why is any of this never described in stories? Because everyone in-universe gives it for granted and nobody cares to worry or followup, same as we do not see the news opening with every landmine field or random bomb from 50 years ago neutralized... unless you have to evacuate half of Hamburg because of it. It would actually make for nice background story material. [Answer] One of the quirks of travelling at such speeds in "normal space" is that a stationary rocks are effectively travelling at that speed relative to you as you crash into them. That's true of any particle or object between your point of departure and your point of arrival. What's important to note is that physics doesn't care whether I punch you in the face or you headbutt my fist, the outcome is the same. In other words, in a universe with normal space ftl, it is essential to have some easily accessible form of resistance to simple objects at relativistic speeds. What this means is that the mass driver described in the question is a useless weapon in ship to ship combat as it wouldn't even reach the same level of damage as hitting a rock on your way to the battle. Since ships tend to be aimed at planets and boosted up to such speeds, it's perhaps not unreasonable to shield your planets as well. You don't need to worry about species that don't think of this, or don't have a solution to it, as they'll either never make it out past their own Oort cloud or blow up their own planet long before they much trouble the rest of us. [Answer] Idk, man. Just use a normal Alcubierre drive or basically any Space-time warping FTL. Since these drives move the space around the ship instead of the ship itself, a ship with a failed drive will exit warp at the same (sublight) speed with which it entered, which may even be a state of rest. And as far as the SW portion is concerned, I would like you to know that Shit-do ramming was completely lore-inaccurate, and a result of Disney, as usual, confusing hyperdrives with warp drives. Hyperdrives send a ship into a separate dimension, where they move much larger distances in realspace with every unit they move in hyperspace. Of course, objects which generate large mass shadows (think the gravity wells of planets, stars or black holes) generate "mass shadows" in hyperspace, which pull a ship back into normal spacetime of entered and may even destroy it (this is why ships cannot jump anywhere near a planet). The Supremacy, though large, will not generate a mass shadow even close to what is required, and even if it did, the Raddus would only collide at sublight speeds. Thus, that scene broke lore very badly. [Answer] Since no one answered it I'll go with the FTL answer from a special universe you might be acquainted with: our own. The Alcubierre drive is derived from the equations of Relativity, and would allow the object to travel faster than light without all the problems that would normally entail. Below you can first find a publication with the benefits quoted in this answer, but I suggest you read the article as well. Below that is a video of PBS Space-time about the subject, I dont know how reliable they are but apparently the speaker does research in Quasars so the channel should have more reliability than the average site. <https://www.researchgate.net/publication/258317793_The_Status_of_the_Warp_Drive> Notable are the advantages in this paper: Benefit 1: Removal of interstellar distance barrier, as no longer restricted to subluminal speed limitations. Get faster than light travel, as measured by distant observer outside of disturbed region. This will allow missions to the nearby stars and closer examination of astrophysical phenomena than is possible today. Benefit 2: It is a conventional transport scheme, in that it requires no ‘tearing’ of space or non-trivial topologies (i.e. wormholes) and does not require the transmission of copies of objects across space as a means of getting to the destination (i.e. teleportation).Warp drive is a simple transport from origin to destination through space. Benefit 3: No time dilation effects, as usually expected with other space propulsion schemes due to special relativity. This is because the vehicle could be moving at subluminal speeds so that clocks on board would remain synchronized with the origin and destination. Benefit 4: No relativistic mass increase of vehicle, since ship is at the centre of warp bubble is at rest with respect to locally flat space. Benefit 5: No requirement for rocket type propulsion to achieve near light speed, which usually restricts the maximum speed attainable due to special relativistic effects such as infinite thrust for infinite masses. Benefit 6: Technological and economic benefits to mankind. (1) (PDF) The Status of the Warp Drive. Available from: <https://www.researchgate.net/publication/258317793_The_Status_of_the_Warp_Drive> [accessed Jan 29 2019]. For some background information you can watch this: <https://www.youtube.com/watch?v=94ed4v_T6YM> [Answer] From a Traveller pen-and-paper RPG point of view: FTL travel is more like "wrinkle in time" travel than "really really fast" travel. The jump drive steps you into jumpspace, you fly along at no net change in realspace velocity or heading, and a week later you pop out of jumpspace as if nothing happened, except you're now a few light-years away from where you started. Almost like a side-effect of something else happening. That said, even Traveller struggles with the fraction-of-C-rock bomb effect. [Answer] > > Sir! An object in motion stays in motion... unless acted on by an outside force, sir! > > > You don't need space dust. **There are already known *outside forces*** in space **which cause drag**. The solar wind from our sun is an example. Whatever speed the ship pieces were at, they would not continue at that speed indefinitely. From a practical "world building" view this isn't widely known/understood/appreciated, so I'd go with "the lack of a functioning hyperdrive" making this irrelevant, instead of the physics.stackexchange.com view. To be blunt, some things are best ignored. Like if you allow a FTL bullet and miss a ship but hit a planet (or maybe it deflects off the ship) the inhabitants *who aren't hit* still have to deal with the burst of x-rays, gamma rays, and scattered particles caused when the near light speed debris hits their atmosphere. You can see the effects of a baseball traveling at 0.9c [here (https://what-if.xkcd.com/1/)](https://what-if.xkcd.com/1/) the physics of which appear to be legitimate and then extrapolate in your head what an item of larger mass would do. [Answer] For this answer I'm assuming you want a ship to be able to get to a destination FTL instead of just being able to move FTL. If you just want a way to give FTL travel but none of the kinetic headaches why not just have a drive that folds space on itself and the ship transposes itself into the new location. It would drastically reduce the effectiveness of using FTL as a Military weapon. Defense against it would be a generator that creates a field that causes improper folding and sends the FTL somewhere else. Making all/Most/Some planets equipped with these generators would prevent drunk Aliens from transposing whatever they want anywhere on the planet. Wouldn't be able to use it to rob a bank. If that is still to powerful just make it so that any type of FTL needs an end anchor point to guide it and that using it without it would just scatter your energy across the universe because of [Insert Tchnobable] [Answer] The FTL drive of the ship might have a, for now, undiscovered physical mechanism to propell the ship beyond c. However this mechanism works in detail, it might only be able to affect a confined system (like the spaceship). So even if your superluminar vessel "hits" another ship or even just an asteroid: it could transfer absurd amounts of engergy/momentum, but the striken object might not accelerate beyond c itself. So the excess of kinetic energy might just be instantly transformed into heat or radiation. At worst you may have a flaming ball of plasma shooting near the speed of light towards a random destination but this isn't really "unusual" in our universe? [Answer] Consider that a black hole is already dragging in light, it has "FTL" effects. Perhaps your black holes are your inter-galactic defenders. The shrapnel will be subject to getting chomped up by sentient and hungry black holes roaming within and without galaxies. [Answer] Holdo's maneuver doesn't make sense, even in the SW universe. (I didn't let it ruin the movie for me, but it's dumb.) You can't go FTL and stay in normal space; this is basic science that every geek knows. So you can't ram another ship using your FTL engines. You *could* maybe purposefully exit from FTL in the same (normal) space occupied by another ship. I would think that would do a lot of damage, cause reactor breaches, decompression, etc. Just not a spectacular ramming. So, the answer to your question is that your "problem" is a non-problem. BTW, a spaceship firing a kinetic weapon with that much energy would have to SUPPLY that energy. BTW, energy from kinetic rounds doesn't necessarily all get deposited in the target, but instead punches holes through it. The energy only gets deposited if the round encounters armor thick enough to absorb all that energy. So, the proper defense against sci-fi railguns is to build ships with fairly thin walls, many compartments, multiple redundancies, and explosion failsafes. Also, make ships very maneuverable. The counter to this defense is to have the ammo spread out into many pieces after launch -- a railgun shotgun. The counter to the railgun shotgun is...armor. ;-) [Answer] # Don't worry, the odds of actually hitting anyone are quite low Your concern is accidental ultra-relativistic (or even superluminal) shrapnel, produced by a collision with a ship using a warp drive. I assume each piece of shrapnel has the destructive force of a nuclear bomb, as per your numbers in the question. A direct hit would ruin a city or spaceship, but it is far too low yield to damage an astronomical body. If the shrapnel is able to crack a planet, then the spaceship's warp drive would have a power output exceeding the Death Star. If your garden-variety FTL drives can power the Death Star a hundred times over, then you have bigger security concerns than mere shrapnel. Therefore, I shall assume nuclear bomb levels of destructive force. For this shrapnel to actually cause harm, it needs to strike infrastructure or populated territories. However, *space is really big*. And even more importantly, things in space are also *really big*. It is a reasonable bet that the pieces of shrapnel are going to hit *something* eventually. Even considering drag from the interstellar medium as Murphy did in [his answer](https://worldbuilding.stackexchange.com/a/138734/55824), any piece of debris of substantial mass has an effective range on the order of a million lightyears. But the question is what they will hit. A lot of the material universe, at least that which isn't made of dust and free gases, is made of stars and planets. So let us take our solar system as an example and assume that the distribution of objects is similar in our solar system as it will be elsewhere. The probability of hitting an object is proportional to its cross-sectional area. The objects in our solar system have cross-sectional areas, from largest down, 1. The Sun: $1.519695684 \times 10^{12}$ km$^2$ 2. Jupiter: $1.535468464\times 10^{10}$ km$^2$ 3. Saturn: $1.065303332\times 10^{10}$ km$^2$ 4. Uranus: $2.020769922\times 10^9$ km$^2$ 5. Neptune: $1.904568191\times 10^9$ km$^2$ 6. Earth: $1.27516118\times 10^8$ km$^2$ 7. Venus: $1.15058579\times 10^8$ km$^2$ 8. Mars: $3.6092848\times 10^7$ km$^2$ 9. Ganymede: $2.1746610\times 10^7$ km$^2$ 10. Titan: $2.0830723\times 10^7$ km$^2$ 11. Mercury: $1.8699187\times 10^7$ km$^2$ 12. Callisto: $1.8254256\times 10^7$ km$^2$ 13. Io: $1.0423372\times 10^7$ km$^2$ 14. The Moon: $9.484174\times 10^6$ km$^2$ We could keep going down the list, but the objects just keep getting smaller. Here, we have $1.519695684 \times 10^{12}$ km$^2$ of star, $2.993305607\times 10^{10}$ km$^2$ of gas giants, $2.97366732\times 10^8$ km$^2$ of rocky planets, and I have listed $8.0739135\times 10^7$ km$^2$ of moons, although there are more moons which would increase this number by a bit. The total area in this list is $1.550006846\times 10^{12}$ km$^2$. We can see that, by area, the solar system is overwhelmingly composed of the Sun, at 98%. The gas giants make up only 1.9%. Rocky bodies like Earth make up only 0.1%. The odds of hitting an isolated spaceship or space-station are so astronomically low as to not be a concern. We can reasonably assume that gas giants and stars are not populated (at least, not by anything more than some space stations), so we only have 1 piece of shrapnel in a 1000 hitting anything which *might* have people on it. Looking at the picture of Admiral Holdo's manoeuvre, it looks like there might be a few thousand pieces of shrapnel there. So we've gone from 'exterminate half the known universe' to 'hit a couple of planets'. That's a substantial improvement on the original prognosis. However, the situation gets better. Most inhabited planets are likely to have atmospheres. These atmospheres would absorb a lot of the energy of this shrapnel via impact-driven nuclear fusion ([relevant xkcd](https://what-if.xkcd.com/1/)). Any small pieces of shrapnel would not even make it to the surface. Only the big pieces would be of any threat to a planetary population. The majority of the ultra-relativistic shrapnel is likely to be made of small pieces, since larger pieces are harder to accelerate. So we could probably reduce the number of impacts by a factor of a few. Thus we go from 'hit a couple of planets' to 'maybe hit the surface of a planet'. If you ask about planets without atmospheres, it is probably reasonable to assume that only a small portion of planets without atmospheres have any sizeable habitation, and even then their population densities are likely much smaller. These factors are probably similar to the mitigating factors of an atmosphere. However, even if you hit the surface of a planet, you are still quite likely to miss people. Earth is 70% ocean and 30% land, with people living only on the land. And of that area, only 3% of it is urbanised. Which means if you were to hurl your shrapnel at a random point on the Earth's surface, you would have only a 3-in-10 chance of hitting any people at all and only a 0.9% chance of striking an urban area causing major loss of life. Some sci-fi planets are substantially more urbanised, but some are also substantially less urbanised, so it probably balances out. Over the course of this question, I have downgraded the severity of Admiral Holdo's manoeuvre from 'universal cataclysm' to 'moderately small chance of nuking a single city'. Granted, this still isn't good, so the unnamed Gunnery Chief is still right to tell his recruits not to fire blindly into space. But it is hardly the universe-breaking apocalypse you had first thought. I assumed here that many planets are inhabited (a la Star Wars). Since you have so many populated planets, the loss of a single random city on a random planet is hardly going to dent the galactic population. If you assume that only a small number of planets are inhabited, then the chances of you accidentally hitting an inhabited planet go down proportionally. Now, if hundreds of such collisions took place in every single space battle, then we would have cause for concern. But having that as your intentional strategy would be deliberately reckless and unethical. However, if we assume that only the occasional idiot or desperate hero makes such a collision, then the risks are, on a universal scale, quite low. I still wouldn't like to be in one of those highly unlucky cities destroyed by a piece of stray shrapnel, but it is a far, far better prognosis than 'condemn half the universe to utter destruction'. [Answer] # Energy is conserved. This is one of the laws of physics that was discovered by Newton. The rest of Newton's physics has been changed with both relativity and quantum mechanics, but this basic fact stands solid. FTL travel must mean that physics as we know it is not complete, but the safest bet is that energy will still be conserved in the new physics. Of course, you as the author can just state it as a fact, if you want to. What does this mean? It means you can't get more energy out of an FTL collision than you put in as starship fuel. This makes the universe safe. The most energy-dense fuel we know is anti-matter. If put in contact with the same amount of ordinary matter, both will convert completely in energy. The maximum can be found using Einstein's famous $E=mc^2$. You end up with energies that can be very bad news to a single planet, but not noticeable to a star. However, simply storing the same amount of anti-matter and having an accident with that would be *just as bad* as having star ship shrapnel rain down. [Answer] I have read a book (i don't remember which one, but it was from the age of Asimov's first books), in which this problem was neatly solved: FTL in that universe used some kind of "physics bubble" (compare it to the warp field in star trek), which extended a few light-seconds around the producing vessel. These bubbles were unable to interact, so any time two ships would be closer than that light second to each other, the FTL would automatically fail, dropping the ships into sub-luminar speeds untill they got far enough away. Making FTL work in a way similar to this will indeed limit the dangers of such idiots, since super-luminar collisions are impossible by definition (for reference, a light-second is roughly the distance between the earth and the moon) [Answer] **Robotech!** I am surprised that I have not seen this answer yet, but if anyone remembers the Americanized Anime show from the 1980s, Robotech, they had a unique and interesting take on FTL travel. Basically an FTL drive in the Robotech universe was a device which would create a sphere of energy around itself and essentially teleport anything inside that sphere to a location potentially many light years away. This is similar to the "space fold" concept. The ship is not achieving superluminal velocity at all, it is simply exchanging it's place with whatever is at a different location. In the very first episode of the series, we see the potential to weaponize this type of FTL drive when the SDF-1 is forced to make an emergency space fold while still inside the Earth's atmosphere, not very far above an island in the South Pacific. The result is that the ship inadvertently teleports a significant chunk of the island with it into space. Clearly, this kind of thing could damage planets, cut enemy ships in half, etc, but the total potential for destruction is fairly limited by the size of the field which can be generated by the drive. In an interesting side note, the size of the FTL field that can be generated seems to be proportional to the size of the ship creating the field, which kind of makes sense (it's never spelled out in the series or completely explained) which may explain the incredibly large size of some of the ships that exist in the Robotech universe. In any case, this basic concept: that the ship's engines (whatever allows it to move through space) are a totally separate system from the FTL "fold drive" which basically teleports the ship to a different location is a foundation which can be used to plan out a science fantasy/space opera universe. I have no idea how the creators of Robotech intended to deal with the admittedly unlikely event of two ships choosing to fold to the exact same location at the same time. I think they didn't think it through that far. I would suggest that either both folds fail, or there would be a huge explosion: whatever is more interesting for the story. [Answer] **Conservation of Energy** Simply posit the following for your FTL drive: * The vessel goes into an alternate space or alternate phase or whatever you want to call it, in which all FTL travel takes place; * In this space or phase, distances are somehow "shorter" than regular space, so that travel can be accomplished far more quickly, even by a ship travelling at subliminal speeds. * It takes a certain amount of energy to put a vessel into FTL space; the energy is linear to the mass of the vessel, and inversely proportional to the flatness of space. * A vessel can only exit FTL space at a point whose escape velocity in normal space is equal to the escape velocity of the entrance point. All of this means that your thrusters only need to get you far enough out to where your FTL drive will work, and no more (so nobody will build them). There won't be a danger from ships traveling at relativistic speeds because there won't be any ships going this fast in normal space in the first place. [Answer] ## Peace and Lack of Access Right now, we have access to technologies that could wipe out humanity, and yet we haven't. The reasons are twofold: there haven't been any major (direct) wars between nuclear powers, and nobody else has access to these technologies. To translate these across, we need: Firstly: humanity is reasonably united, and hasn't encountered any hostile alien races, so there haven't been any significant wars to wipe out massive chunks of the map. Secondly: FTL technology is absurdly difficult and expensive to manufacture, to the point of being the sole domain of of major governments/maybe one or two massive corporations. Thus, no idiots flying around at FTL speeds wiping out planets. That doesn't mean you can't have civilian interstellar spaceflight: maybe the FTL technology is in the form of stable wormholes maintained by the government, or space stations that sit at convenient junction points, extracting a fee for accelerating ships up to FTL velocities towards another such station, and decelerating any ship that gets thrown towards it at FTL speeds back down to something safe. Whatever. Thirdly: making FTL systems is very obvious, and there is an active and efficient investigation force that identifies anybody attempting to do so and prevents them with extreme prejudice. Fourthly: whatever they are, the FTL facilities that do exist are extremely secure and well-defended, preventing terrorist attacks from taking them out. Between these, we have a situation in which the only people with the capacity to use FTL systems to cause massive amounts of chaos don't have any reason to want to do so, and the people who do have reason to want to do so have easier routes to doing so. [Answer] **There is no actual FTL *speed*** You don't need to worry about FTL debris if your FTL transportation method actually requires a functioning device to arrive at the destination before the light does, and it doesn't require the ship to make any sorts of relativistic speed records either. Any kind that does some sort of fourth-dimensional shortcut method (Hyperspace, wormholes, travel through the hell dimension, wrinkling of the spacetime to actually shorten the distance, and so forth) will do just nicely, and the only thing you'll have to worry about is telefragging of something on the arrival - but just push the allowed exit points outside of gravity wells, and the chances of such a collision instantly are reduced to being an astronomically rare event, since you now can accidentally intersect only with rocks and other ships, and the results of that would be significantly tamer. ]

[Question] [ The setting is mid-medieval in technology, vaguely European. There exists no magic in the setting except what is explicitly defined in this question (which all relate to dragons). Dragons are the traditional winged, scaled, fire-breathing beasts of fantasy, ranging in size between that of a horse and an elephant, and with intelligence between that of a dog and a human child, depending on the dragon's bloodline. Their hides are a bit tougher than elephant hides. They are fairly nimble; clearly more than an elephant, but less than a tiger. They can fly for short periods of effort. In summary, each are incredibly worthy opponents as far as animals go, but can be (and are) killed. They aren't numerous, but there are enough of them that (and they are troublesome enough where) most kingdoms face the need to hunt them down and kill them every couple of years. Killing a dragon results in the killer being cursed by the dragon's spell; they adopt limited/partial physical characteristics of the dragon enabling them to be more effective at killing dragons (not proportionate to *their* size), but also visibly mark them. The more dragons killed by one individual, the more he changes. The changes to the dragon slayer are also mental as a slayer becomes progressively more: * aggressive * paranoid * predatorial * survival-focused These are mental afflictions, and can be compared to developed mental disorders, like PTSD, as to how they interact/affect/etc one's personality. They possibly can be managed, but these effects never go away. With changes to the eyes or scales around the hands and the face, even after the first dragon killed the slayer is physically marked in ways that are near impossible to hide. Most slayers devolve into something entirely animal (mentally) after five or six killings (if they survive that long), limiting any dragon slayer's career, and life as a member of society. There is no way to game the system (have multiple people attack at once) to increase, decrease, distribute, or stop this death-curse. The only way to avoid the curse is to not kill a dragon. The only way to gain the curse is to kill a dragon. The physical characteristics increase the slayer in raw ways one associates with a large beast (physical strength, ability to weather punishment, appetite) but also more particular traits like flame retardation and eyes accustomed to bright flashes. These enable them to be far more likely to successfully engage with a second or third clash with a dragon than anyone else. They never gain extremities like wings or a tail. --- In the end you have this odd cycle where killing dragons creates a *better* dragon slayer (unavoidable), but also a ticking time bomb; even killing one dragon could devolve a normal soldier into a bandit, depending on the strength of his character. This is a reality, and something that the kingdoms have to deal with in some manner or another. What is a strategically intelligent manner of dealing with this reality for the kingdoms? What is objectively a good policy about managing killing dragons, and then utilizing (or dealing with) the slayers? [Answer] To understand what would happen, we must look back in history. These people survived next to Dragons for thousands of years. Either they coevolved with them from the start, or they showed up here long enough ago that their culture has changed to adapt to them. When an early stone-age people encountered dragons, they would either avoid them, kill them, or domesticate them, or some combination. If they are ameniable to domestication, the character of society changes. War dragons become core weapons technology, as a flying fire breathing beast would change how you'd have to fortify things. Assuming they are not, or that is highly limited (a society of mountain-dwelling swiss who have a domesticated high-altitude breed would be interesting), it leaves avoid and kill. Extinction violates the terms of the question. So I'll assume dragons have a massive geographically restricted advantage over humans, but elsewhere humans have a massive advantage. These "badlands" would be populated with dragons, while humans cannot safely go there. The advantage has to be so large that people would rather *starve* than enter those regions, or doing so is suicidal (at least until very very recent times). As only dragons can be magical, suppose there are areas where there are tiny, tiny dragons, the size of dragonflies, or even smaller. These fire breathing tiny creatures have the dragon's curse. They are native only to some parts of the continent, and they are endemic. Being in these areas basically is a death sentence for humans. Other creatures don't suffer the curse, so other wildlife exists. From these regions larger dragons emerge. --- In ancient times, while humans and dragons coexisted, killing a dragon would become a rite of passage. Doing it more than once would be considered taboo, and you'd be exiled. Human culture would select for opposing the effects of the first "dose" of dragon curse, as societies that did not would fall apart. As the dragons are pushed into their sanctuaries, only the warrior caste would continue with the dragon-cursing. Knights and other warrior caste members would have a ritual dragon-slaying, which makes them larger and stronger. They would be selected and indoctrinated before and after with ritualistic behavior and meditation. Religion would be built around this. If it can be managed, they would form the ruling caste, as it is hard to avoid your warrior caste from taking over. Possibly a matrilinial system would develop, where non-warrior women would manage society, while dragon-cursed warrior-monks would protect it. "Wild" dragon-cursed individuals would be a constant problem, as the system to control them wouldn't be perfect. Double-cursed would be hunted down and killed as too dangerous. Possibly dragon-cursed who could not manage their curse would be consigned to the gladiator pits, or maybe they would even generate multiple-cursed warriors especially for that purpose (and as shock troops in war). Another alternative is that the dragon-curse would be trained against, the individual would be cursed. Then tested to see if they are mitigating the problem well. These tests would be passed down in the order. If they are well mitigated, a *second* dragon-curse would be applied to make them even greater warriors. Such warriors would be tested, and if they fail would be culled. Various societies would develop around this process. The controlled harvesting and killing of dragons would be done; letting a dragon-warrior loose to hunt risks the dragon-warrior killing and then going rogue. So this is only feasible if the tests where *really solid* and predictable, at least one step out. [Answer] **You make it a semi-religious order, or a military order.** The 'Order of Slayers' is a prestigious order dedicated to studying, and combating, the dragon problem. Out of this order, very few can actually be 'dragon slayers', with the majority of the order being support staff, scientists/scholars, and so on. You make a series of strict rules and regulations for the order. Basically making it a *huge* honor to be slayers, but its a sacrifice: They will be monitored and controlled for the rest of their lives. You then elevate these slayers to national hero level, but still emphasize their sacrifice in publications about them. In return, these slayers' lives are guaranteed. Food, clothing, weapons, luxurious apartments, men/women, and so on. They will not be paid. Their *every need* will be met (to a reasonable degree). On top of this, the Kingdom will guarantee that their immediate families are looked after: with generous annual stipends, priorities in schools/healthcare, etc. NOTE that these privileges are reserved only for families of *slayers*, not just any member of the Order. There is a class of soldiers, in the Order, who are responsible for the slayers: Both to keep them safe, and keep them in check, and even kill them if they go out of control. For slayers at the end of their sanity, you can either eliminate them quietly with these troops, or you can set aside an island sanctuary where you will ship them off and let them roam and kill each other (if that is what will happen) for the rest of their lives. Of course you will need to keep this from the public, so every time one 'retires' you hold a ceremony extolling the virtues of the slayer and claiming that he has died in the order and has been cremated. The family will be honored by the kingdom. This will inspire the people, keep the slayers' heroic reputation intact, and ensure that there will always be people applying to join the Order. [Answer] ## Easy * You catch the dragon using disposable peasants, steel nets and whatnot. * You drag the dragon to the public square (or a clearing or whatever, if a square is inconvenient with all the dragonfire and stuff). * You use your death row convicts to deal the death blow. * If the death row convict refuses to kill the dragon, he/she is tortured for days before being put to death. * You then hang the death row convict dragonslayer (optionally, use the convict for more than one slaying). [Answer] **Ostracism** Ostracism would be definitely there for the dragon slayers. However, it would be the slayers who would ostracize themselves from the society and not the society which discriminates them. For the society, the slayers would be heroes and saviors. However, the slayers would be wary of the society, living in seclusion. **Reward and Limitation** There would probably be some official reward for killing a dragon. However, every city/large town would only be allowed to have no more than two (or at most three) dragon slayers. As in, if there are two people belonging to London who are active dragon slayers, other people from London would be barred from pursuing this career. Only after one of the slayers is dead or disabled, someone else from the city can kill their first dragon and begin their career. The slayers would be paid a one-time handsome reward for killing each dragon and then a good amount of money (or resources) every month. The one-time reward would be paid by the federal government (king) while the monthly amount would be paid by the citizens of each city/town for their slayers. **Overwhelmingly Problematic Slayers** While the community would cope with the usual personality issues about slayers, a particularly cantankerous or violent slayer would be silently set up for his/her death by a royal decree, ordering him/her to slay specifically cunning or powerful dragons within a short period of time. In case of his/her victory, the number of dragons for future missions would continue to increase, until the slayer finally meets his match. In some cases, for an ultra-genius slayer, the king might secretly order other slayers to track and kill him/her. [Answer] There are any number of techniques one can use, some of them drawn from how history has treated generals, gladiators, and soldiers. 1. Ostracism: dragonslayers live apart, are barely tolerated when coming into town, and are shunned. The physical markings make this easy. 2. Cloistering: dragonslayers live in an opulent palace with plenty of servants, but can't leave the building except when going off to fight. 3. Religious constraints: being a dragonslayer means you have a special relationship to the divine: you don't even get a chance to go after a dragon until you spend years being inculcated in a religious and moral code. Each time you kill a dragon and subsequently change, you undergo additional training. [Answer] Dragon vasectomy. In South Africa, elephant overpopulation is a serious problem. Instead of culling the herds, populations are controlled by people whose job it is to tranquilize bull elephants and surgically castrate them. (Generally regarded as one of the most unpleasant jobs in the world.) Reptiles can be surgically castrated, so presumably dragons can be as well. You can have teams of specialists going around dealing with your dragon problem by neutering the males. No killing required! And as an added benefit, it might make them less aggressive in the meantime. You can add this to traditional dragonslayers who are willing to take the burden of the curse. Neutered dragons can be marked so that dragonslayers don't waste their time on them. [Answer] If killing only one dragon is going to turn a reliable soldier into a bandit, then most dragon slayers will most likely not kill more than one dragon. This is because, given the survivalist/paranoia traits resulting from the curse, they'll no longer have their previous motivations to obey the king and serve the kingdom and put themselves in the harm's way again. You'll end up with a highly trained but undisciplined captain Americas type of army that'll come handy in attacking/looting neighboring kingdoms. This army will be a bit hard to keep disciplined but not entirely unmanageable with the right leadership and incentives. That being said, I do see them going back to kill more and more dragons for one reason - They get addicted to gaining more and more strength. It's like being high on meth/crack, they love the newly acquired energy and the overall feeling and keep wanting more and more of it no matter the consequences. In this case, you don't even need to do anything, they'll just seek out more and more dragons themselves until they're killed themselves. Also, this dragon slayer thing seems to be a great way of disposing off undesirable elements of the society. For example, give the criminals a choice between immediate execution and becoming dragon slayers who'll be pardoned if they kill the dragon(s) with the condition that they'd not commit a crime again. Regardless of what they choose, they'll be rid of. Finally, if the dragonslayers must be non-expendable citizens, psychiatric treatment will alleviate most of those symptoms. If appropriate psychiatric medicines are not available, then drugs like opium/marijuana etc would probably keep them reasonably subdued. Assuming they become heroes and get great rewards, they don't need to stay particularly functional. Make them priests or assign them honorary positions that don't require them to do anything but keep them fed and living with good lifestyles. If we want to create a stable system type of thing though, the King should introduce a **Mandatory/Obligatory State Service** type of arrangement. This is how it'll work - Every year (or every few months), a chosen family/village will be required to appoint an able bodied man to be the dragonslayer. The family will be appropriately compensated for this service if the appointed person is killed or otherwise "tainted" while fighting the dragons during this period. After an year (or if the appointed person is dead), the next family/village will be chosen and so on. But this system will work only if the dragon's are infrequent enough and will not work long in the real world. I address how things would go in a realistic setting in the next paragraph. All that being said, I think **in a realistic setting like our world**, what's really going to happen would depend on whether dragons can be tamed or not. The ones that have dog like brains will be tamed and become assimilated in the human society. The ones that can't be tamed will be destroyed. Kings will deploy parts of their armies against the dragons. The dragons will be hunted down and killed in large numbers fairly quickly and their habitats destroyed permanently. Dragons will either go completely extinct or be reduced to numbers and sizes so that they're no longer a threat. The symptoms would be considered just a known hazard of the job because these people grew up with all this. The soldiers who go a bit crazy because of the dragonslaying expeditions will be sent off to other expeditions/wars and forgotten until they die off. [Answer] It could serve as annunciation of crimes. So you give the convicted murders (they are already good at killing so why not) a chance to kill the dragon. If they kill it great the threat is over and they are pardoned. If they do not survive then good also one less killer to worry about. They would of course have to escorted by armed guard to the dragon and you have to make sure you have more guard then prisoner so they don't think they have a better chance of surviving by attack the guards instead. [Answer] That is a pretty cool concept. **Dragonslayers are recognized, respected, and rewarded by society as selfless, tragic heroes.** Dragonslaying is a tough job, but someone's gotta do it. Individuals who set out to become Dragonslayers know that it will kill them - Either because they fail and one of the dragons, well, slays them, or they succeed, and become dangerous and mindless. Dragonslayers are treated with a mixture of apprehension and respect by the community, and are typically provided for by the community. When they die or inevitably turn feral, their dependents, if any, are cared for by the community, and feral dragonslayers are kept in asylums and cared for, if they're not too dangerous. If they are, every effort is taken to make their death as humane as possible. In advanced and wealthy societies this might take the form of a government salary for the slayers, a state pension for their dependents, and the asylums would be government institutions. In rural or primitive societies, the community would provide these things voluntarily out of a sense of duty and respect, and it might not be possible to provide the feral slayers themselves with humane asylums. Desperately poor people might take up dragonslaying to provide their spouse and children with financial security. Others might do it out of a sense of patriotic or religious duty. Others might be motivated by hate or revenge, after losing loved ones to dragons. [Answer] If people are wise to it being a losing game, then pay off their families. There are always people who will do terribly unpleasant things to be sure dear old mum is looked after. The slayer probably won't care as much about their families after the first round, so after that maybe you pay off the slayer with land and freedom. Ideally land far away, maybe with current owners you don't like. If you have enough people who are interested in such a deal you just have some of the surplus kill slayers that make trouble, it could even be a barrier to entry. [Answer] you need to train dragonslayers, make it a noble endeavor, make sure they know it corrupts them, you create zealots who only want to killing dragons or die in the attempt, who will kill themselves if they survive because they will have been taught for decades that they will become monsters. basically you're creating a cross between fire fighters and suicide bombers. compensation to the family should be a given, but honor, and service will be the real motivation. [Answer] Do we even need to kill the dragons at all? Based on the OP, the dragon population of the world is such that this only becomes a problem every couple of years or so. So, instead of killing the dragons, invest time in developing techniques to herd them away from populated areas. Maybe even research techniques (either chemical or surgical - no magic required) to neuter dragons and control the population that way. Basically we're using the same sorts of techniques used to control real wild animals, like tigers and eagles, modified to account for the fire breathing. Alternatively, since you said some dragons have intelligence equivalent to a human child, we can try to domesticate them. Human children CAN be reasoned with, and can even be fooled - relatively easily - into doing things your way even when it's against their own best interests. So find a way to convince these more intelligent (relatively speaking) dragons to police their own kind. Offer them food they find delicious but which requires preparation they can't master themselves, or something. I mean, there's a reason we don't just kill all the tigers in the world, after all. Why should dragons be handled differently? To be sure, there will be times when a dragon NEEDS to be killed, but these approaches should help to minimize those occurrences. The resulting cursed humans can be dealt with through methods already outlined by other answers, which will be so much the easier for there being notably fewer such cursed humans to deal with. [Answer] **Cursed gladiators!** Every few years, when it's time to kill some dragons, send out of the most dangerous, hardened criminals the kingdom has (ones who would have been sent to death row or life imprisonment anyway). Obviously these criminals would be accompanied by numerous guards and escorted to wherever the dragons are. If the criminal dies to the dragon, whatever. If they don't, the guards will collect them and escort them back into their holding cell. After the dragon slayers are given enough time to rest and prepare, they take part in a death-match arena battle. The final winner gets a decent sized fortune, and their family will be cared for and live like nobles. The dragon slayer would have to be heavily monitored, but at least there'd only be one every few years. The dragon slaying and gladiator match would probably be a grand event, accompanied by festivals and looked forward to by the people (maybe even criminals). Maybe even give the potential for normal, non-criminal people to join too if they wanted. You have the problem of safely sending the criminal to kill the dragon and retrieving them: the dragon slayer would probably rather flee than risk their life for a potential fortune. A potential solution would be giving the criminal a slow acting poison (death within a day or so), then giving them the antidote if they come back alive as a dragon slayer. [Answer] One option is to create a quasi-religious cult of dragon-slayers in which rigorous discipline, training and indoctrination mitigate the negative social aspects. In this context it is also worth nothing that the real problems of thing like PTSD tend to manifest themselves once an individual has left the military and tried to integrate back into civilian society. Indeed one interpretation is that the problem is not so much that they have been damaged by their experiences but that they have been rigorously trained and conditioned to one very specif lifestyle and then have to 'unlearn' all of that to adapt to a completely different social environment. So one approach is to have an order of dragonslayers who carefully monitor their initiates and retire them into either administrative roles or padded cells as appropriate. Hopefully a combination of discipline, a well ordered social structure, practical support and monitoring could mitigate the worst effects it also gives you a system where you can pass on some of the practical skills and experience to novice dragon slayers through organised training, teaching and documentation as well as having the opportunity to research the effects in some detail. Also if all else fails having an organisation of dragon slayers being self-policing may be the best chance of keeping rogue individuals under control although you may not want to put all your eggs in one basket and have several different orders who have a responsibility for keeping an eye on each other. [Answer] **Noone kills the dragon, they are diven off** If the cost of killing a dragon is such that noone will bear it, then it makes sense that some "civilized" cites/territories would be in the business of just making the dragons life more uncomfortable than the pain of the dragon finding a new nest. This could include fortifying barns and outfitting them with large pikes and other deterrents where the herds would be kept at night. Dragons could continually be "smoked out" of their lairs, rivers could be diverted so they are flooded, putrid dead animals could be dumped into the nests. Even digging out their nests, so that it offers little protection from the elements. (all of this while the dragon was out hunting, I'd presume) Generally making the dragon's life miserable until they move to the next territory, preferably, in someone else's country. Trapping and relocating them in the middle of the ocean, or down a pit where they would be starved to death? Even better, try and point them at your enemies! Imagine releasing a hungry dragon on an unsuspecting enemy army! [Answer] There are many strategies. (using convicts has merit. A group that monitors the cursed is another.) Monitor the dragons. Move then into enemy lands. (Heck, breeding up these suckers to use as weapons makes a ton of sense.) Injure without killing and drive them into neighboring lands. This isn't just kicking the can so someone else has to deal with it. If you drive them into your enemy, it will weaken their forces---except for the cursed one. Send them at a good rate, and their best chances of stopping it will be that same hero. IoW, you are removing a great hero from an enemy and dealing with the dragon. Dragonherds are going to be far more valuable than slayers, honestly, unless it's not possible for some reason. Those that can produce barriers to them, as well. If they can be tamed, they'd make great support animals for war for similar reasons. The more immediately disastrous the first kill, the more powerfully the strategies will lean towards forcing others to kill and using the curse as a weapon. If a population learns how to live among them, they might not even drive them away. Makes a good deterrent. (An Indian friend of mine showed me photos of the house he grew up in which had shelves for cobras to use so they weren't underfoot. That's the sort of adaptation I mean.) [Answer] Dragonslayers would be superhuman, and its possible that it would take 24+ normal men to subdue them. Because of their abilities and often unstable mental state, they would make excellent assassins (assuming they are sufficiently motivated to remain on target). The more mentally stable ones would be required to be personal guards against the assassin dragonslayers. There would need to be a weakness though... something like a sound (like a dog whistle) that would cause pain/discomfort. Otherwise, why wouldn't these superhumans take over the world? **Edit (to better answer the question):** Without a balance of power, the dragonslayers WOULD take over the world, even if that world was ruled by chaos. As far as how to handle the people, make the dragonslayers to be a stigma, and killing a dragon should be avoided at all costs. Make it common knowledge that all dragonslayers would be hunted down and killed regardless of their previous station. Make it part of a religion so that regular folks are afraid of the "demons" and will report them. You would need a highly trained team of non-dragonslayers (Paladins) that has the sole purpose is to hunt down rogue dragonslayers. How to handle the dragons? Well there would still need to be dragonslayers, but they should come from within the religion itself... warriors that came from the Paladin ranks and have already been thoroughly indoctrinated so that the changes from the curse would be much less of a risk. They would belong to an elite order within the religion (that claims a God Blessing that grants them immunity to the curse), but they wear full armor to conceal their identity. As far as their families know, these warriors were killed (and the warrior is convinced/forced to forget his past). As far as the public is concerned, these "holy dragonslayers" are a rumor/legend and are rarely seen. [Answer] A strict and severe Monastic order would probably be the best way to deal with it. I'm not adding anything to what has already been answered, but I see a synthesis of many answers here. Start with a monastic order of knights. It would be tightly bound with the state religion. Anyone can join, commoner or aristocracy, but it would be like the priesthood. It's a one way ticket. You will be cared for, your family gets a stipend, and they basically mourn you as dead because they know you aren't coming back. You renounce all titles, land, etc. You even give up your name. Once in, it becomes a strict meritocracy. Everyone trains to fight, and they train very hard. This Monastic order is not just going to be for dragon slaying, they will also be the kingdoms elite troops. They will take turns doing things like guarding the palace, the treasury, etc. These duties will be shared by all who have **not** yet killed a dragon, because you need to be mentally stable when guarding a king. I think we can agree paranoia would be bad for this. Once judged to be good enough to train as a true Dragon Slayer, you go through an apprenticeship with an experienced slayer (one with 2 or 3 kills). You become their lackey, more or less, and spend even more time training, training, training. You go with them on your first mission, and they will be your backup in case you fail. If you succeed, hurrah, if not, they kill the dragon and then retire to the top tier, hunters of the rogue dragon slayer. They would be strictly cloistered after this. They would be encouraged to write their memoirs or perhaps channel their aggression in the forges making weapons for future dragon slayers. They could take on the basic training in combat arts for the brand new recruits (not one on one, but group). The key to all of this is the monastic rigidity, and not letting anyone accumulate too many kills. Those that have graduated to the top tier need to be kept busy, with appropriate outlets for aggression. The more kills, the more one must spend in relative isolation, perhaps with a brother who is also very senior, but not a slayer himself. You don't want powerful whack jobs to spend too much time all alone. [Answer] **You Capture Dragons Instead** You don't kill the dragons. You incapacitate them. You then bring them back and lock them up. They can be tamed, used for milk, or for entertainment. They can also be used as beasts of burden. Bring them into war on your side, so your opponents kill them instead. [Answer] Why does the hunter need to kill the dragon himself? Would the curse follow poisoning or trapping? A hunter could rig the dragon's lair to collapse trapping it to suffocate and completely avoid any curse. He could leave a tasty poisoned goat out the front. He could take out a wing and leave it crippled to starve. There are plenty of ways you could take out a dragon without having to swing the sword yourself. [Answer] No peasants are allowed to kill a dragon, only professional dragon slayers. Every time a dragon slayer kills a dragon his face is marked. A dragon slayer may not kill more then four dragons in his life. After a dragon slayer kills his forth dragon a test of his sanity is preformed. If he fails he is killed, If he passes he joins the elite hunters. these hunters hunt rogue dragon slayers instead of dragons. ]

[Question] [ Jellyfish are... weird. They're clear, slimy, and can sting after death. Sounds perfect for experimentation, so let's weaponize them! Consider a hypothetical world where jellyfish are extremely common and you can get them cheaply anywhere, and there's an extreme fascination amongst the human population with them. ***In this world, there's a war going on but there's a shortage of materials. Luckily, you have millions and millions of Jellyfish at your disposal, stocked up. (Don't ask why the government has them stored up)!*** The government has asked you to design some weapons using those jellyfish as parts. You can use any part of any type of jellyfish in your weapon, but the main application of the weapon must be based off of jellyfish. Main list of weapons types: * Projectile weapons * fluid weapons (flail, whips, chains) * rigid weapons (Swords, clubs, staffs) * Armor/shielding **Of the above types, how effective would the jellyfish based application be, how would it work/be made, and how well would it work (against traditional weaponry (modern) and other jellyfish weaponry)?** Note: Bonus points for coming up with a jellyfish based war machine! [Answer] Would you be interested to know that annually, **Jellyfish kill more than ten times as many people as sharks do?** Not bad for a creature that is 95% water and doesn't have a brain! That being said, aside from stinging people to death and weighing down fishing nets, jelly fish are pretty slow and useless (6m/min is considered fast for a Jelly fish). They wouldn't be any good for delivering projectile weapons, attacking with melee weapons, and there'd be no point in armouring them. Jellyfish could be weaponized, just not in any of the ways you've proposed, except maybe with a whip, which wouldn't actually whip people, but just touching them would be sufficient to kill them, in fact this is how 20-40 people die in the Philippines every year, by coming into contact with one of the 3m long tentacles of the box jellyfish. ## Jellyfishes Greatest Advantages 1. **Numbers:** There are literally BILLIONS of jellyfish in the Ocean, and they mass in swarms of thousands and millions. They only live for a few months, so their numbers constantly grow and regrow, you can kill as many as you want, and in only a few short weeks or months their numbers can be back to what they were. In 2005 a Swedish Nuclear plant had to shut down because of a [jellyfish invasion](http://www.theguardian.com/world/2013/oct/01/jellyfish-clog-swedish-nuclear-reactor-shutdown), the sheer numbers clogged the cooling system, threatening a meltdown. 2. **Stealth:** Jelly fish are 95% water, so it's hard to distinguish them from the rest of the ocean water, there are even some species that appear to be completely *invisible* to the naked eye while in the water. Though slow moving, a massive swarm could approach a target without being easily detected by instruments. 3. **Fearlessness:** Jellyfish have no brains, they only have a simple nervous system, this makes them mindless and fearless, they are essentially the zombie hoard of the ocean, innumerable, and unstoppable, combined with their sheer number, you could send swarm after swarm at an enemy. ## Possible Weaponized Applications: Since Jellies don't have brains, you can't really train them to do anything, and they're slow, so they can't chase anything down, or fight, or do anything really except for float around, but you could still make use of them. 1. **Sting Nets:** Imagine an impenetrable net of Box jellyfish tentacles, anyone that ventures in gets stung and dies. 2. **Bombs:** A jellyfish swarm could carry a huge payload of explosives, especially if they were modified so that a good percentage of their liquid mass was an explosive similar to nitro-glycerin. Such a swarm could make short work of ships, submarines, docks, even power plants and factories. They'd also work well as a defensive tool, no one's going to venture into a swarm of exploding jellies. 3. **Chemical Weapon Delivery:** Jellyfish are known to wash up on beaches numbered in the millions and then just rot. Suppose they were infected with disease or an agent that turned into a toxic gas once exposed to the air and sunlight. The Jellies wash up on shore, and then their rotting corpses release whatever toxin they're carrying into the air which kills everyone within a mile of the beach, allowing an invading force to land on the beach unchallenged, and onto a softened battle field. Essentially, you're going to have to work with the way Jellyfish currently behave, and think up applications which take advantage of their short lifespans, their mostly water body composition, and their sheer numbers in swarms. Mounting anything to a Jellyfish would be pointless, you may as well as try to attach a bayonet to a water balloon. You don't want to put anything expensive on a jelly fish either, because it's going to die in less than 6 months anyways, and you can't train them to do anything, because they won't live long enough to learn anything. You'd have to develop a signal or something you could use to control the swarm and where it goes, take advantage of their numbers to overwhelm an enemy and choke them out. --- [Read these fun facts about jelly fish.](https://www.nsf.gov/news/special_reports/jellyfish/by_numbers.pdf) [Answer] *Now kids, don't try any of what you are about to read at home. You do not want to mess with the Geneva Convention.* I am going to answer both, how you can weaponize jellyfish (sea jellies, to be pedantic) and how to take what we've learned from jellies to make more powerful weapons. First off, start your breeding program now. You are going to want lots of them. Get yourself a ton of the Malo kingi. Mess with the genes responsible for their breeding cycles. These guys are tiny and next to invisible in water. They weigh little enough that they have been picked up by waterspouts and dropped miles inland during a storm. They also have predictable migration patterns, and have been found to swarm toward bright sources of light. Before you invade a country, seed the clouds in the area with silver nitrate, and when they build up to saturation, drop in millions of Malo kingi. **Do not** invade while it is still raining. You will regret it. You may also want to add them to the drinking water about the same time. Drop them in an appropriate body of water and lead them where you want them to go with a small robotic swimming drone armed with a powerful laser. The two steps above will decimate your enemy's population before you put a single pair of boots on the ground, maybe even leading to surrender. Secondly, aside from the obvious poison, what makes jellies so dangerous is their hypodermic injectors. These are bundles of tightly wound filaments that uncoil to a thousand times their bound length and release with the slightest contact. Imagine a bullet filled with similarly coiled razor-wire. The moment it penetrates its victim, the core uncoils and rips the target to shreds. Nearly any shot that penetrates a victim is a guaranteed kill, and if it collides with body armor, it will shred the fabric of it, disconnecting any plates. The second shot **will** hit a soft target. If these wound-roundsTM are coated with venom, the lacerations caused by a near-miss will still kill potentially multiple targets. [Answer] * Projectile weapons Jellyfish launched from a simple t-shirt launcher could be roughly equivalent to a taser in effectiveness (or worse if you can get a hold of a nice box jellyfish). Still, the range leaves something to be desired. * Fluid weapons (flail, whips, chains) Jellyfish jelly arms aren't all that great for tying together, but a flail with jellyfish heads would be fairly effective at adding pain to hits. * Rigid weapons (Swords, clubs, staffs) Jellyfish tentacles sting after death... perhaps applying grooves and lining them with tentacles? It would eventually run out of stinging ability. * Armor/shielding Removing the stinging parts of jellyfish leaves you with... jelly. It could be a pretty good filler for padding. It would weigh a lot (it's mostly water!) but you could probably line the walls of an attack truck with a layer of it fairly easily. Jellyfish armor could protect you from blunt jellyfish weaponry (and the JellyLauncher (patent pending), but would prove ineffective against the stinging sword. Of the weapons, against a non-armored person the JellyLauncher would appear to be the weapon of choice. Even then, it wouldn't be as good as a modern weapon. Ok, seriously: You could use the stinging cells in nearly any application, from dart guns to a plank with a nail in it, but most of these things are already deadly enough that the sting of your average jellyfish won't contribute much. This changes with box jellyfish, which can be deadly, but that still leaves you with low velocity weaponry or blunt weapons. [Answer] The other answers pretty efficiently cover what you can do with stinging jellyfish. If I may summarize: When dead: put on your enemies with whips/bombs/tshirt guns/long sticks. When alive: sic on your enemies, possibly fill with bang juice. Now: let's consider nonstinging jellyfish for a moment. BUT WAIT you cry, what is the point of a stingless goop in warfare? Let me tell you about [Pykrete](http://en.wikipedia.org/wiki/Pykrete). It's ice cut with fibers, which improves shatter resistance and raw strength, as well as melt resistance. Do you see where I'm going here? Gelatinous frozen-jelly-armor can be feet thick, shatterproof, and absorb thermal attacks. Because it's water-based, HEAT rounds will cause tiny steam explosions, neutralizing the shaped charge. Tanks coated with frozen jellyfish would have a jelly layer on the very outside roughly .5 jelly thick, anchored in a layer of ice. Deep inside the ice layer, put a condenser and cooling equipment to keep the ice cold over very long periods(for battle you can turn it off) and you can even repair your tank in the field with more jellyfish! Slop them on the craters in your armor, put a tarp over the thing, come back in the morning for fresh new impenetrable armor. (you said anywhere in the question. So. Anywhere.) In order to enhance thickness I would recommend putting iron rods through the armor like long spikes, to conduct heat down into the cooling zone and increase the thickness without having to get too overboard with chillers. Ice is a great insulator. They're also probably useful as a glue when rendered down in a big vat, but not better than like, horse hooves. [Answer] When there is enough food and jelly fish they create very large swarms / blooms. These have been known to block up the intakes to power stations in the past. [1](http://www.theguardian.com/world/2013/oct/01/jellyfish-clog-swedish-nuclear-reactor-shutdown) Take a large number of jelly fish, plenty of jelly fish food and dump them in the sea near your enemy power stations. Inland power stations usually have a cooling lake near by. Of course in your world you will need to seed the jelly fish inside the netting they would have to keep out the natural/local jelly population. [Answer] Start with [Irukandji jellyfish](http://en.wikipedia.org/wiki/Irukandji_jellyfish). These tiny creatures (the bell is roughly 5mm on a fully grown adult) are incredibly toxic. From Wikipedia: > > Irukandji syndrome is produced by a small amount of venom and induces excruciating muscle cramps in the arms and legs, severe pain in the back and kidneys, a burning sensation of the skin and face, headaches, nausea, restlessness, sweating, vomiting, an increase in heart rate and blood pressure, and psychological phenomena such as the feeling of impending doom. > > > And all that is without any help from ill-meaning scientists. Oh, yeah, and by the way: > > the Irukandji also has stingers on its bell > > > and: > > ...the ability to fire stingers from the tips [of their tentacles] and inject venom. > > > And you thought *Jaws* was scary. Now, if you have millions of these tiny creatures, there are a variety of ways you can weaponize all or part of them. ## Water toys The simplest way to weaponize them would simply be to fill a large-bore water gun with them and fire them at your enemies. Low-tech, low cost, and very dangerous, the tiny creatures will leave your enemies writhing in agony and doom *at best*. Body armor won't stop them, either; all it takes is a 5mm hole and the tiny jellyfish *will* sting them. Any water toy will work, too. That's right. Squishy splash balls, sponges, water guns, water balloons, and even squirting rubber duckies could be converted into a weapon, simply by filling them with jellyfish. If you are a horrible, evil, black-hearted, soulless person, you could even send children with water guns to attack enemy soldiers. No one suspects a child with a squirt gun, at least until everyone starts screaming. ## Terrorism Dumping a few thousand live Irukandji in swimming pools, drinking water, even puddles on the side of the road will wreak havoc. But why bother with the jellyfish? Extract the venom for use as a poison! There are countless applications for the venom alone; as an additive to anything from drinking water to improvised explosives, the venom can make a bad day much, much worse. victims won't be stumbling out of wreckage covered in dust; they'll be thrashing on the ground in burning agony. If you want to leave an impression on the local population, that's the way to do it. ## Semi-Lethal Spreading Mines A normal explosive mine is bad, but often it leaves nothing but a corpse, and if you're in a hurry, a corpse is easy to leave behind. Instead, fill mines with jellyfish barbs. Upon release, the barbs will be flung out to attach to anyone nearby, injecting them with the venom and leaving the victims in pain, but alive. But that's not the worst part. When that soldier is taken to a field hospital, anyone that touches him without a strong pair of gloves (leather would work; thin rubber of latex would not) will *also* be injected with the venom, as the sharp, springy barbs stab into them. Even if all that happens is that contaminated clothing is washed with uncontaminated clothing, there is a chance for the barbs to spread. ## Bioweapons Thus far, everything has merely used parts of a jellyfish. But what if we apply Science™? Breeding Irukandji jellyfish in captivity has thus far proven unsuccessful, but then again, we already have truckloads of the things, so I'll assume we've gotten that part down. Once we can breed, we can selectively breed; as fast as jellyfish reproduce, it won't take long to create an even more powerful venom, or a venom that highlights certain aspects - for instance, the pain and agony part is reduced, while the "sense of impending doom" is strengthened. Now instead of a drug that causes pain, we have a mind-altering drug. Enemies gassed with an aerosol form would be panic-stricken, even to the point of self-harm. Other non-lethal forms could include a sprayable form, similar to mace, or a diluted form use in riot guns or water cannons for riot control. It's hard to riot for the cause when you are shivering in pain and wallowing in thoughts of *doooooom*. *Note: Please don't try this at home. Or anywhere else. It's terrifying, and you'll probably end up stinging yourself (which is what the scientist who discovered the Irukandji syndrome did, though, and it got named after him; who knows, you might end up famous).* [Answer] The biggest problem you have is that you've been asked to do this by the government. So let's take care of that. First, hire a bunch of pharmaceutical engineers. Have them develop an efficient way to extract poison from the jellyfish. Use that to supply the government with blow darts. This will turn out to be lame, but since you're a campaign donor and since it's what the government asked for, just not what they needed, you'll be fine. Now that you have a steady government contract you can hatch your real plan, skimming. Take the most deadly of the jellyfish out to make herbal supplements. Don't actually claim it cures cancer and warn people about how incredibly dangerous it is. Make them sign liability waivers. The more you hype the danger the more people will want it anyway. Soon as someone dies dilute the heck out of it and call it "homeopathic". Now you're free of reliance on the government. Use this same cynical view of mankind to branch out into other ailments until you have a vast economic empire. Whenever your enemies confront you, you can hire a team of lawyers to sue them into oblivion. Or just smack 'em in the face with a bucket of jellyfish chum. Whichever's easier. [Answer] Never underestimate nature. Nematocysts can do some amazing things. Özbek et al. calculated accelerations of 5.4 million g in deployment of a *Hydra* nematocyst. Velocity was "only" 18.6 m/s but that was achieved in 700 ns. The tip hits the prey (armor piercing attack upon the shell of a crustacean) with 7.7 GPa pressure. Özbek S; Balasubramanian PG; Holstein TW. 2009. Cnidocyst structure and the biomechanics of discharge. Toxicon. 54: 1038-1045. [Answer] All of these would be terrible, terrible choices. You're better off beating people with a tree branch than with a jellyfish, if only for the massive logistics issue. Just attempting to transport the jellyfish to a warzone will spoil them. You don't have the time to make weapons out of them unless you're doing it near the battlefield. If the government gives you a large supply of stored jellyfish, the best way to weaponise it is to throw away the jellyfish and melt down whatever containers they were keeping it in. It probably contains more useful components than the jellyfish do. As a final note: poisonous weapons are a really bad idea on a battlefield. The odds of brushing up against a friend and killing him, or touching the wrong part of your weapon are quite high. You are likely to suffer immense losses due to accidental poisoning of your own troops. [Answer] Isn't the obvious answer to arm your Jellyfish with the everything it is lacking? **Introducing the Jellyshark!** You thought scientist learnt their mistake when crossing a [Shark with an Octopus](http://www.imdb.com/title/tt1619880/). But the folly of man is unlimited. In the darkest labs of government research comes to Jellyshark! Scientists have managed to isolate the Jelly part of the Jellyfish and successfully removed the 'fish' part and replaced it with a SHARK! The result is an invisible and highly poisonous version of the Sharktopus! [Answer] Send torpedoes filled with jellyfish into submarine propellers until they wear away ]

[Question] [ The McDonald's fast food company is the world's largest restaurant chain which prides itself with offering (almost) the same standardized menu all around the globe... ...*this* globe. When humanity colonizes Mars, how large would the population of the colony need to be in order to provide all the infrastructure and industry required to allow McDonald's to open an economically viable restaurant which offers the complete menu without having to rely on off-world exports? [Answer] A (local) population of about ten thousand people should be enough. In my opinion there are three factors here. 1. Is there enough need for a restaurant? There seem to be around [14.000 McDonalds restaurants](https://www.statista.com/statistics/256040/mcdonalds-restaurants-in-north-america/) in the US, which is roughly one per 23.000 inhabitants. Assuming that the first one on Mars will be on the smaller size and have less competition, 10.000 potential customers should be fine. 2. Can you produce the menu items? I think this is the easiest point. Most of the ingredients derived from plants will be fine, something like lettuce, grains and tomatoes will be among the first things grown on Mars anyway. Meat will be harder since raising cattle would cost more of the limited available labour and greenhouse-space than it would to directly grow crops, but lab-grown meat is definitely no further in the future than large self-sufficient martian colonies. And since the colony needs to eat, the food will have to be there anyway. Interestingly, the only problem I see is the packaging. Large amounts of trash are most likely a no-go on a small colony and neither the wood for paper nor the oil for most common plastics will be easily accessible on Mars. 3. Are you allowed to do this? Actually I think this is the critical point. Depending on your vision of the future, martian colonies will either be state funded military/science/vanity missions, or research/mining/vanity operations bankrolled by large companies and conglomerates. This means that initially all colonists in a location will be permanently bound to an employer and critical resources like food, water and energy will be centrally controlled. You'll have to wait quite a while and most likely a few generations for "free martian citizens" and an internal free market to develop. The more likely option is outside involvement. Just think of the publicity of being the first interplanetary fast-food chain. So the most likely thing is that some company executives on earth will just cut a deal and some company/state-run cafeteria on Mars will be rebranded into the first McDonalds in space. Edit: Another point mentioned in the comments is the economy of scale. It is true that they will not be able to keep their cheap earth prices for food, but neither can anybody else. Most likely the colony's food production will be centralized at this stage anyway and the martians food will either payed for by the colony's owner or the colonists will just expect that food is a lot more expensive. [Answer] **The Law of Averages** This is actually easier to figure out then you might expect, however the mars aspect does change things slightly. I'm going to use the UK figures for this as i'm from the UK. and therefore its easier. but please remember that it depends of the type of people you send, Americans are much much bigger fans of Fast Food then the rest of the world, places like the Netherlands use it huge amounts less, i used the UK as my example as they seem to be much more in the middle of the two extremes According to MacDonalds themselves: they have over 200 restaurants in London UK, London has a population of 8.136 Million. <https://www.mcdonalds.com/gb/en-gb/help/faq/18647-how-many-restaurants-are-there-in-london.html> Lets keep maths easy and say 200 to 8 million, that means that those 200 restaurants can survive trade on 8 million population plus tourists. which according to google is about 19 million tourists each year. so 19 plus 8 is 27, divided by 200 stores equals 135,000 **potential customers** per restaurant to keep them afloat. <https://en.wikipedia.org/wiki/List_of_countries_with_McDonald%27s_restaurants> This page suggests something very different, however its worth noting that service station due to require a local population, their business is entirely dependant on traffice through an area rather than the area itself. i struggled to find the amount of service stations with a MacDonalds to remove these from the totals to get an accurate Restaurant to Population Ratio However mars will not be a big city at least at first, it will be colony, the closest example we have of that is an island. so... Channel Island of Jersey, Population of ~100,000, has 1 MacDonalds, Isle of Wight, population of ~139,000, has 2 MacDonalds Isle of Man, Population of 84,000, has 1 MacDonalds Channel Island of Guernsey, Population of ~63,000 has none. So going with these averages... it suggests around 1 MacDonalds to every 70,000 to 80,000 population. You can use the same type of averaging to find out how many of any store are needed to support a given population, from Car Sales to Computer Stores. although obviously the factor of not having locally available products with which to key that food would be a key factor in this. [Answer] Do you allow for gov't subsidies? Once a corporation wins the bid to feed the Martian colony, what they charge the customers is insignificant relative to the subsidy. Alternatively, MacD's corporate marketing dept may decide that the publicity back on Earth will increase Terran sales enough to offset the "loss-leader" restaurant on mars. [Answer] The big M sells 1 hamburger for 1 $. No small restaurant can offer the same price, because they don't have the scale economies behind their product. To have a Mars Donald you would need a completely terraformed Mars, to be able to have livestock and feed them with food grown on the planet. Growing livestock and their food requires a lot of water. You would then need something similar to the society of the '60s, to be able to replicate the same scale economies, logistics and technology. The crops and other things used to feed the cows are not grown together with the cows. They are made in a place and transported to another. You also need a massive organization behind it, to carefully control and manage the production chain. And you need an environment and a society to support the people working in that organization. I assume that, in order to have such an advanced level, you would need to have at least a couple billion people living on Mars (in 1960 there were about 3 billion people on Earth). [Answer] # 100,000 + This answer goes a different route. While other answers look at the product sold and the customer numbers, I am looking at the workforce. McDonalds employs largely minimum-wage employees in a franchise scheme. That means you need a society large enough that there are people living on Mars who are not highly qualified scientists, engineers, etc. but low-wage service personel. And you need enough of them that competition has pressed wages low enough for the McDonalds business model to work. You also need someone to run the business, i.e. a franchise owner. Which means your society is large and developed enough that you have entrepeneurs and freelancers. As long as your Mars colony is a government entity or a whole owned subsidary of Mars Exploration Inc. this doesn't happen. When looking at the real world, you can see that societies in the thousand or ten-thousand numbers can easily function in a closed model. Many international corporations are this size. Many government agencies are this size. In fact, according to <https://en.wikipedia.org/wiki/List_of_largest_employers> there are a couple organisations in the 1-2 million range. Which is why I am putting my number on 100,000 at the very least, possibly higher, before you have the social and economical environment where a franchise business employing minimum-wage workers can even exist. # or around 1,000 The above assumes a proper McDonalds restaurant more or less identical in operation to one on Earth. Of course, for simple reasons of branding, it is highly likely that McDonalds would make a branding cooperation with the local cafeteria the way [it already does with schools and hospitals](https://foodrevolution.org/askjohn/mcdonalds-in-hospitals-and-schools/). My guess at around 1000 is based on the fact that the McMurdo research station is around that size (1,258) and its cafeteria begins to look more like a school or corporate cafeteria than a military mess hall. Branding is definitely not far off, and if it were more high-profile (like it would on Mars), certainly someone would already have thought about it. [Answer] # 1500 **That's just an arbitrary number isn't it?** Not entirely, it seems that someone on Quora asked ["How many customers are there per McDonalds store"](https://www.quora.com/On-average-how-many-customers-are-there-per-McDonalds-store), to which the lowest value was: > > At my current store we may serve 500 (max)people each day but most of that is during the breakfast and lunch hours. > > > (responses mostly from McDonalds staff) and [McDonalds own 2009 report (PDF)](http://www.mcdonalds.co.uk/content/dam/UK01NewsAssets/Reports/Eating%20out.pdf) said: > > Last year, 1 in 8 meals were eaten out of the home.This year, it will be 1 in 9 > > > So assuming everyone eats out one meal every three days and McDonalds is the only show in town, you need 1500 people to support a McDonalds. --- # In practice far more Running a McDonalds requires a specific culture. It depends on a society that can afford to be wasteful, afford to have minimum wage workers (a percentage unemployed), afford to have people who aren't dedicated simply to keeping the facility running. You'll also need a significant population of the type who would eat at a McDonalds\*, as part of a self sustaining independent colony. **So at least 10-15,000, possibly upwards of 500,000.** The chances are McDonalds or KFC are highly likely to be the first branded fast food joint in town, but not likely to be the first place to eat. There will be a race between the big names to get the first outlet opened, whether that will be maintained once that first outlet opens is a matter of whether it's economical in the long run. The first may well be a temporary store just to say they'd done it. *\*Who are these people? The food is filth!* [Answer] What do you mean by "economically viable"? Because: **The first McDonald's on Mars will almost certainly operate at a loss.** McDonald's will deliberately choose to open a restaurant *before* that restaurant can make money individually, for two reasons: First is the PR benefit back home. This has already happened. [Pizza Hut famously delivered to the ISS](http://www.spaceref.com/news/viewpr.html?pid=4921). It was a huge loss, if you only consider that delivery, but here we are still talking about it 17 years later. Similarly, a McDonald's opening on Mars could be huge news, and they could continue to make news over time as they slowly expand offerings. But that's just the icing. The other reason is McDonald's doesn't want to end up as the Mars equivalent of Arby's. McDonald's leads the fast food market on Earth, and they'll want to lead the fast food market on Mars... and that means getting started early learning how to the handle the distribution, labor, payment, construction, regulatory, and many other issues that are sure to come up in the extreme environment. They want a foot in the door, and they want to be *first*, so as the Mars colony grows they're best positioned to open their *second* restaurant... and the third, and so on. So 150 years later, the Martian family goes to out to McDonald's rather than Burger King. McDonald's, especially, has a history of multi-generational marketing in this way. It's why their mascot is a clown, and why the Happy Meal is such an iconic brand. With those things in mind, I think it's reasonable they would consider a population similar to an aircraft carrier, which has some of the same supply concerns, even if at a smaller scale, but still manages accommodate [at least one major brand](https://www.navy.mil/submit/display.asp?story_id=74026). [Answer] **Just One.** McDonalds is actually quite a proactive and progressive company. It experiments regularly with different ways to market, create, and distribute its products. Research and development is a strong focus of the company in all these areas. It even [explored a NASA mission to 449 Hamburga](https://en.wikipedia.org/wiki/449_Hamburga) as an advertising opportunity, which is indicative of how novel the company can be. Earlier last year, McDonalds produced a [McDonalds Vending Machine](https://www.youtube.com/watch?v=9BxusfdDd9k). The purpose was to trial and test a new Point Of Sale system and create a bit of novelty. McDonalds Australia and many in the U.S. have now ramped out this system such that many stores now have new P.O.S. systems for customers without the need for staff interaction. With available [3D Printing techniques](https://www.dailymail.co.uk/sciencetech/article-2530195/The-future-cooking-PRINT-dinner-Dont-scoff-3D-printers-make-food.html), it may be possible to combine these technologies to create the first no-staff store. McDonalds already makes headway into [3D printing straws](https://3dprintingindustry.com/news/mcdonalds-reinvents-straw-3d-printing-105772/) and [also toys](https://matterofform.com/mcdonalds-3d-printing/), and there are calls for [3D printing its burgers](https://www.fabbaloo.com/blog/2016/12/22/crazy-idea-of-the-week-mcdonalds-should-be-3d-printing). There is research underway for cultured patties and aeroponics systems for long voyages and remote areas. It is easy to see the benefits for McDonalds to have a sustainable, reusable, 3D printing McDonalds Vending Machine, the first such one, on Mars: 1. Viability: McDonalds is an all-encompassing company, with 37,241 stores in 120 countries, and an annual revenue of $10 billion USD. The marketing budget alone is a major cost, with sponsorship, advertising, and community programs forming a major part of its operation which contributes to its positive image and presence in the public eye. Economic sustainability of its stores is supported by such a large organisational effort franchisees are generally well-assured of commercial success regardless of circumstance, however loss-making stores are well supported too, and closures of McDonalds are almost unheard of due to this support. However the opportunities for Mars would be more in Marketing and Image. 2. Marketing: McDonalds has the resources to spend and produce the above, simply for the purposes of putting McDonalds 'on the map'. Such a claim to be the first restaurant on Mars would be a great boon to the image of the company. With relatively little investment, such an endeavour can yield years (or even decades) of 'free' ongoing marketing opportunities for McDonalds. It is the ultimate in product-placement, and compared to their numerous Sponsorship deals, enormous marketing budget such an investment is small. 3. Image: McDonalds is also very keen to reform its image. Being renown for fatty, unhealthy foods in the 80's has made it actively correct for this since, with strong community focussed programs and advertising to alter this. Sustainable farming, childrens health, salads, locally sourced beef and vegetables, even the new 'brick and wood' fitouts, all are orchestrated towards this image. A Mars mission could yield benefits to this image in terms of technological progression and research, food re-use and sustainability, and health. 4. Menu: McDonalds regularly changes its menu to suit local factors. Obviously the Big Mac is a staple, however all other products are adjusted to suit the local market (although the patties are carefully altered also to suit cultural requirements in different parts of the world). The technology above could yield its own 'space menu', enjoyed by just one voyager (the mission Commander perhaps) not just for its variety from freeze-dried food but also a way to eat lettuce, tomato and other foods, in a way to 'remind' the Commander of home. All you need is one person to enjoy the above benefits - although the real benefits would be of course mainly to McDonalds regardless. [Answer] Now this is only my opinion and speculation. But I think that > > When humanity colonizes Mars > > > will be at a time that humanity has reached a post scarcity civilization. Money will maybe not even exist anymore. Everything will be free and McDonald's restaurants will be fully run by robots. So maybe the Mars population could actually be 0. It might well be that people send robots to setup and create a restaurant even before the first humans even decide to migrate to Mars. [Answer] # TL;DR McDonald's is a real estate business that not only depends directly on people buying burgers, but on the indirect value of traffic to their location. # Long Version From [If McDonald’s Is A Real Estate Business, What Business Are You In?](https://medium.com/@PeterTanham/if-mcdonalds-is-a-real-estate-business-what-business-are-you-in-d4bffaaab174): > > In 1954, aged 52, Ray Kroc joined McDonalds as a franchise manager. 10 years later he bought the entire business for $2.7m. > > > He was an incredibly successful businessman, building McDonalds from a small chain into the most successful fast food operation in the world. > > > A story is told about some advice he once gave to a class of Harvard MBA students. He asked them all, “what business is McDonalds in?” > > > “Restaurants!” “Hospitality!” “Supply Chain!” “Franchising!” “Entertainment!” > > > “No!” Ray laughed and replied to each student. > > > “Ladies and gentlemen, I’m not in the hamburger business. My business is real estate.” > > > And from [Business Lessons From Ray Kroc "The Founder" -- McDonald's Story](https://www.forbes.com/sites/bradauerbach/2017/01/20/business-lessons-from-ray-kroc-the-founder-mcdonalds-story/#338df1513534) > > Despite a handful of successful franchises up and running, Kroc is nearly out of cash. His slice of the business is tiny, and the bank is threatening to foreclose on his house mortgage. > > > A fortuitous intervention by Harry Sonneborn, another fast food executive, steers Kroc in the more lucrative direction. “You’re not in the hamburger business, you’re in the real estate business,” Kroc is told. Keaton’s monumentally expressive face registers the logic, and he pivots into buying up the real estate which he leases back to the franchise. > > > The real estate corporation McDonald's should find such a franchise economically viable if the *property* provides value to them. Part of that value comes from the lease, and part from the increasing value of the property. It needs to be worthwhile to the operator in order to afford the property lease. It needs to be worthwhile to McDonald's if the value of the lease and the value of the property combine for more income than their expenses (cost of the property, taxes, insurance, etc.) The value of the lease depends on the volume of business that you asked about. The value of the property depends in part on that, but also the value of the land itself. That is, it would depend on other businesses building nearby, so the desirability of the land increases as more and more businesses want to build close to McDonald's. Why do those businesses want to build nearby? Well, to get the overflow from McDonald's, for one. For another, traffic. (Hey look, a battery shop! I should get some AA batteries since I'm going by there anyway...) Overall, yes, there's some critical mass at which the number of people make the restaurant profitable to the operator. But it's more complicated than that for McDonald's as a corporation. I think that any projections at this point in time will prove to be wildly inaccurate when the idea becomes reality, even with substantial consideration of the issues involved. Nevertheless, that's not a deal-breaker for your world, perhaps, if you can leave plenty of wiggle-room in your expression of it. EDIT: And as others have mentioned - PR! A McDonald's will be talked about by a myriad of outlets. The value of that depends not on the population of Mars, but of our Solar System as a whole, or at least, the population of all worlds with a McDonald's. [Answer] ## At least one million Source(s): Just trust me on this. Now for reality. The real number is hard to guess, because: * For story purposes, the first ever McDonalds may be offering [localized menu](https://en.wikipedia.org/wiki/International_availability_of_McDonald%27s_products). But lets assume we want to deliver the iconic Big Mac on Mars * It is also worth noting, that the Big Mac might be made from completely different items, because [cows cause global warming](https://www.theguardian.com/environment/2017/sep/29/methane-emissions-cattle-11-percent-higher-than-estimated) ([Skeptics confirmed](https://skeptics.stackexchange.com/questions/41/do-human-activities-contribute-to-climate-change/480#480)). But lets assume that one of reasons to leave Earth is global ban on beef meat and also that greenhouse gasses are needed for Mars terraformation. In my opinion, if Mars has around million people of population, it may be economically profitable to open a venue there. [](https://i.stack.imgur.com/WbqxZ.jpg) Enjoy your food! ]

[Question] [ [There are reasons why we can't walk through walls.](https://physics.stackexchange.com/questions/126512/why-doesnt-matter-pass-through-other-matter-if-atoms-are-99-999-empty-space) Using magic, though, those difficulties fall away. In fact, for a wizard in an otherwise-almost-magic-free world, walking through walls or falling through floors is an ability he can harness on cue. The wizard has used his powers for evil, though, and after a long war against him and his armies, he has been defeated. The victorious army wants to keep him alive but imprison him. They quickly realize that this is a very hard thing to do, as he quickly runs out of a normal prison cell. In fact, they discover that he can escape from anything - ropes, handcuffs, etc. They only manage to move him from one place to another by constantly sedating him. How can they imprison the wizard without keeping him unconscious all the time? They only have medieval technology, though, so their options are quite limited. They want to imprison the wizard somewhere on the planet they live on, which is earth-like. Some notes from my comments: * He can pass through anything, but he has to hold his breath. * He can designate an area of ground where he will not fall through at a given point in time. * He can't fly; most of his other abilities are unknown, but he *cannot* transform some materials into others. It seems that there's nothing else he can use to escape. * There are no other known wizards. The army want to put him somewhere where * He cannot escape * He can survive with food and water periodically given to him, and with a source of air (and ventilation) * High-level officers can interrogate him This location must be somewhere on land, and must either be a natural feature or be buildable by medieval technology. This means that he can't be put in water, outer space, etc. (fortunately, these have not been suggested by anyone). [Answer] **Keep him deep underground.** The fact that he needs to hold his breath means he has a limited travel distance. Take a guess on how far he can run *while holding his breath*, then double it, and put that much stone between him and his next breath. You indicated that he can not fall through stone by deciding it, but can he climb virtual stairs inside solid rock? He may not be able to even climb out of a deep hole. If he can, just factor sprinting-up-stairs-while-holding-breath distance into the depth of the prison. **Visitation** How do you get into this cell to interrogate and feed him? Clearly any tunnel into this cell (or any of the other answers) would give him a place to run to. But it's easy, just use a long series of thin pocket doors. When the doors are closed the gaps between them and spaces which they will slide into for opening aren't wide enough for him to stand in and take a breath. As the guards come to feed or interrogate him they can open the doors and close them behind themselves.  Depiction of pocket-door arrangement, not to scale. Alternatively, the surrounding material may not need to be solid rock, but simply any matrix of material too dense for re-materializing. Dense branches or a large volume of barbed wire wouldn't allow enough open air space to materialize in without catching a branch or wire in the gut. A combination of this and the stone prison could be used, really you could keep this guy in place with a regular jail cell and a whole bunch of bales of hay. Or even a jail cell in the center of a corn field. [Answer] Why is everyone always over-complicating things? **Step 1)** Use a regular room, with a normal, possibly unlocked door. **Step 2)** Sever the evil wizard's Achilles tendons. [Answer] Since he can't fly they could just hang him in a cage over a very deep pit. They could still drop food and water from above to feed him but any escape attempt would result in a deadly fall. [Answer] **An island prison** There are three options here: 1) Strand him on an island. All you need is an island that is about 1/3 to 1/2 a mile from any mainland. This would ensure that he couldn't pass through the ground and make it back to fresh air in time. 2) Build a floating prison (read: boat), anchored to the bottom of the sea. This doesn't need to be so far off the coast as a regular island. His only option is to swim. Guards on the coast should be able to see him coming, and use whatever means they used previously to capture him. 3) If you want to be extra safe, place him in a submerged cell - a cofferdam. Note this would probably be impractical, time-consuming, and expensive, but it would be completely awesome. How to achieve this using medieval tech: * Drive a series of long wooden stakes into a lakebed, to form a circle. Keep each stake tightly touching the one next to it. * Drive another series of stakes to form another circle, enclosing the first, about a half-foot further out. Now you have two concentric circles of stakes. * Pour a clay mortar mixture into the space between the stake circles. This sinks to the bottom and displaces the water. * Remove the water from inside the the clay walls by pump or bucket. * Now the inside of the cofferdam should be relatively dry, and you can climb down and reach the lakebed. Create a stable foundation, and line the inside with stone, mortar, and pitch, to reinforce and waterproof. Note: this explanation came pretty much directly from the book World Without End, by Ken Follett. If there are issues with doing this as I've described in the Middle Ages, take it up with him. Now throw the wizard down in the water cell. You can cover the top, or not, it's irrelevant. For all he knows, he's been thrown into a regular well. Imagine his surprise when he tries to walk through the walls and instead of dirt, he finds he's surrounded by water - complete with spikes/traps/crocodiles/sharks with laser beams. Your guards can resupply him periodically, just boat out to the cofferdam cell and throw down what he needs. [Answer] It might take a little creativity to set one up using only medieval technology but I think that all of the base components are available including black-powder, springs and flint, so... Build your prison like an inverted land mine. The center of the floor is a pressure plate which gets armed as soon as the wizard is placed upon it. The walls and ceiling are all out of reach and are composed of loose steel pellets packed in explosive black powder, surrounded by several feet of solid rock. As long as the wizard lies, sits or stands in the center of the room, the pressure plate stays depressed and nothing blows up. As soon as he approaches any of the walls, or changes the nature of the floor, or phases into the floor, or floats up on a bag of helium, his weight leaves the pressure plate and everything goes boom! Even if he is out of phase when it blows, millions of ball bearings will ricochet through his unsubstantial body for some time. It will be quite a while before the danger passes and the smoke clears. ...and all that time, the wizard will have to keep holding his breath and casting. If you were the wizard, how certain of your breath control, casting ability and concentration would you have to be, to even consider trying to break out of a prison like that? -- simplifying to accommodate non-transforming wizard and the need for feedings, fresh-air and interrogations -- Removing the transformation abilities probably simplified a lot of the other answers, but it leaves this one pretty much unchanged. He can no longer fly or change the walls/floor, but those abilities were handled by the same pressure switch trigger which handled is other magical skills. Fresh air could be provided by a few small vents in the ceiling, each with multiple steel grates to keep the ball bearings from leaving the prison during a blast. Food and water can be lowered on a rope through the vent directly above the center of the room with empty plates and cups pulled back up after every meal. A pale can similarly be provided for removing his waste products. Care would be have to be take to insure that he is not fed more than the weight of the waste products removed so that he doesn't inadvertently set off the bomb through weight loss or gain. Interrogation would have to be handled through the vents with the high-ranking officials wearing armor just in case a stray ball bearing makes it past the grates. Given the tension of being surrounded by a 360 degree claymore mine, I doubt that torture or other motivations will be needed to get the wizard talking. [Answer] **Build a tower and put him on the top** - Best. Prison. Ever. But beware, do not make the tower without a roof, since we know, how Gandalf The Grey escaped Alternatively: **Put him deep underground.** in well maybe. It is nice, that you can walk through the walls, but if there is rock only around you and bonus, you do not know where actually you are? Easy How to feed him? Tower: Give him rope good enough to go into middle. Give him food into some place in the middle of tower, where you get using really tall ladder. If he wants food, he has to put his rope up and wait. Well is better, because you can simply throw bread down and there will be always some water. [Answer] You haven't mentioned that he has any healing powers or that he can move material with telekinesis. All his escaping seems dependent on his ability to walk or run from the prison. My solution is as follows: 1. Gather your best medical professionals 2. Amputate his arms and legs as close to the shoulder / hip joints as possible 3. Lock him in any prison with thick walls and where "straight down" is not an escape route 4. Wish him the best of luck in rolling through the walls at a high enough speed to not need a breath Of course, this depends on your ability to cauterize and sterilize wounds so the patient doesn't simply bleed out or die of infection. You're able to keep him sedated so that should help immensely with the surgery. However, medieval amputations were still risky business. [Answer] If the wizard is otherwise affected by normal physics when they walk through walls, you can use a pulley system to hoist them in a cage or room far above hazardous ground. If they phase to escape, the fall and hazard would at least would cripple them if not kill outright. When you need them, you can place a platform over the spikes/moat/what have you and lower them down. All achievable with medieval tech. The rope and pulleys could be fashioned in such a way that climbing it would be arduous (forty feet up without a handhold) and either: * difficult (far too smooth for the human hand) or * very painful (thorny, rough, etc.). He's a wizard, not a body-builder or soldier, so it's easier to make it likely that he would fall/fail in climbing the rope. Make it too risky to climb and it becomes an unattractive option. One could also add guards with crossbows as "deterrent" - climb the rope and we shoot your legs. [Answer] The answers I've seen have all been about constructing an exotic prison, but I see a much simpler solution. My solution requires an understanding of how the wizard uses his magic. If he needs to speak to cast spells, cut out his tongue. If you want to interrogate him, use paper and pencil. If he has to wave his hands/fingers in complex motions, cut off his hands. The most difficult problem is if he can use magic just by thinking about it, you're going to need something exotic. Since he can transmute any substance into any other substance of the same state, you'll need a vacuum. After all, he can convert magma to solid rock so he suffers no heat harm from it and water to liquid helium which will evaporate instantly (either that or freeze him alive before it converts to a gas). The only thing he can't work with as you've described him is *nothing*. The real problem for an exotic prison is that, without magic, they're fairly impossible to build. Since he's the only known wizard, you're limited to either mundane prisons he can easily escape from or natural wonders involving deep pits. [Answer] Find his best friends and family and keep them as hostages. That's a common ploy for taming superheroes. [Answer] # A ring of fire Anyone can walk through a ring of fire, but he'll still come out extra crispy. Will require a lot of fuel to keep all that fire going, but since there's only wizard, they can probably afford it. If you want to keep him from getting out through the floor and roof, light fires there as well. An an added bonus, it'll be hot as hell in his cell, so maybe after a while he'll agree to play nice and stay put in return for you putting out the flames. Alternatively: # Lots of archers Combined with "that's enough shenanigans, the next time you try to escape, we'll turn you into a porcupine". Assuming the wizard is not suicidal, he'll probably realise that if he leaves people no choice, they will eventually just shoot him and get it over with. [Answer] Hang him by his ankles with cuffs connected over a beam. As soon as he releases one foot he plummets to his death. [Answer] You just need thick walls. Why? > > He can pass through anything, but **he has to hold his breath**. > > > [Comments]: > [ArtOfCode]: How fast can he move when passing through things? > > [HDE226868]: @ArtOfCode **No faster than a normal human** could if the things weren't there. > > > The world record for breath-holding is 20 minutes 21 seconds. However, not only will he be walking (or running) while trying to escape, but likely he's not the holder of that record. Most normal people can only hold their breath for [around 2 minutes](https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCMQFjAB&url=http%3A%2F%2Fwonderopolis.org%2Fwonder%2Fhow-long-can-you-hold-your-breath-underwater%2F&ei=HVEQVYT8AYeZ7Abhk4HgCg&usg=AFQjCNFVWal1La5RLdQeX8vwdanYm60E-Q&sig2=cJXCv7ijHE5sHT1QZiL_Gg&bvm=bv.88528373,d.ZGU). Although that figure would be reduced with physical exertion, I'll leave it at that for simplicity and cell security. Usain Bolt runs at nearly 15m/s (~30mph). Again, our wizard is likely not him. Most normal people run at around 7-8m/s, 16.5-18mph. That means, in 2 minutes, an average person can run 960m. That's a lot. This figure does get reduced, however, since this wizard isn't breathing; assuming a quadratic reduction of his speed per unit distance, we get a figure around 450m. Still, building walls that thick is impractical, *but* there are ready-made walls you can use: underground. Imprison him deep in the Earth's crust and fill up your access holes with cement. If you give these people access to more advanced technology, you can install a video link and microphones for communication. [Answer] The answer is actually rather simple. Build a tall tower, as tall as you can. Place a long metal pole sticking out of one side of the tower, as far out as you can. At the end of the pole, hang a tiny platform, capable of supporting only one man, and made of the thinnest materials possible; a wire net, for instance. Construct a system of pulleys and springs that hold the pole; if it gets too heavy or too light, the system fires the pole out and away from the tower, into open air. The fall through the air will kill the wizard; regardless of what gas he changes the air to, he will still fall through it, and regardless of what solid he changes the ground into, he will still splat when he hits it. The pole and the net will be thin enough that he wouldn't be able to use them to construct a balloon, and he won't have any other materials (say, for example, clothing) to use. He can't climb back towards the tower, or the system will drop him. He can't collect material to use in an escape, or the system will drop him. However, communication is simple, as you only have to yell across empty air. Food and water can be tossed over by unsympathetic guards, who can also trigger the insta-drop by hand, if need be. Edit: As an added security measure, the net should be supported by two ropes, held apart at the top. Each rope should be able to support 75% of the wizard's weight without breaking. Together, the ropes will hold the wizard and the net, but if the wizard tries to climb one of them, it will break, which will cause the second rope to also break, which will drop the wizard to his doom. [Answer] I wonder if something like the setup they had for Magneto would work... a room suspended over lava/spikes/acid with the only entrance through the ceiling. I would build it like this. Take a deep, wide shaft. Line the bottom with spikes if lava isn't available. Build a room with no doors or windows, just a hole in the ceiling. Connect a heavy chain to the top of the room, and hook it to a windlass, which is suspended over the pit. Put the wizard inside the room, and then lower it deep into the pit. Throw food down into the pit through the hole in the ceiling. If the wizard tries to walk through the wall, he'll fall and die, same for the floor. At this point the only worry is the wizard trying to climb the chain, but a guard at the top pours oil down the chain every day, and trip lines have been strung at intervals. If the wizard tries to climb he'll trip the lines, and the guard can cut the chain, or set it on fire... **Edit** Ok, new idea, no prison can hold this guy, you've made him too powerful, so instead imprison him inside his own mind. Give him a lobotomy or some similar treatment. He's still alive, but doesn't know who or what he is or what he can do. Now you can put him in a nice comfortable normal dungeon. **Edit 2** So you need information from him, so a lobotomy might not be the best idea, as the information might be lost. You need him to talk about what he knows, so sensory deprivation. Guards have really short shifts, 30 minutes max so that they don't get distracted, but there is no talking allowed. A water pipe is rigged to allow irregular dripping down onto his prison. Not a steady pattern, so that the prisoner can't get used to it. Sometimes the dripping stops completely, but not for long. It's also his water source, so he'll love it and dread the sound of it at the same time. **Edit 3** With transmuting out of the way, I think my answer stands, though now the shaft can be smaller. It can either be a natural cavern, or left over from a mining project. I has to be wide enough that he can't jump from the platform to the wall, so maybe 40 feet wide, which would give 15 feet of clearance between the platform (10x10) and the the walls. If it's left over from a mine, a shaft several hundred feet deep would be very easy. It would have been the shaft used to haul cars of ore up, so it would already have a windlass at the top. Food could be dropped or lowered by rope, and when they want to question him all they would have to do is raise the platform a bit if they wanted to. Being a cavern/mine, they wouldn't need to get him that close to the top to talk to each other, and wouldn't want him to get to close anyway, in case he has some offensive magic they haven't seen. [Answer] Imprisoning him in his own body seems to satisfy all the requirements, and is certainly well within the grasp of those in this situation and time period. They already have him sedated, and can sedate him as needed. All they need to do is cause paralysis below the neck. He can still communicate, eat, etc with assistance. This doesn't prevent him from committing suicide because while he cannot move himself, he could determine to fall into the earth below and thus suffocate. There may be ways around this but they depend on how exactly his ability works. For instance, being paralyzed and without feeling he may not know enough about the [positioning of all his limbs](http://en.wikipedia.org/wiki/Proprioception) to successfully cause them to pass through matter. As an alternate to sedating him all the time, use the sedative as a spinal block which would temporarily cause reversible paralysis during interrogation sessions, and otherwise keep him sedated. This gives him hope of eventual escape, giving him less reason to attempt suicide. [Answer] How's his tolerance to heat? Can you keep him in a dungeon surrounded by a moat of hot water or oil? He may be able to walk through the walls of the dungeon, but may not be able to withstand being boiled alive by the moat. Making the ceiling smooth means that even if he can float up to the ceiling with his magical helium balloon, he won't be able to get a handhold to let him climb through the ceiling - the balloon will just bump up against the ceiling - though it's unlikely that his clothes would contain enough fabric to make such a balloon, it would have to be quite large. Putting the boiling water under the chamber as well too might make the floors too hot for habitation, so just leave it hollow underneath and let him know that if he tries to transform the thick stone floor to dirt and tunnel out, the guards will flood the underside of the chamber with boiling water as well. [Answer] He can pass through walls, but he will need to **walk** in order to do so. **Suspend him into a anti-gravity bubble**, so that he cannot walk and reach any walls, making his special ability useless. [Answer] **SOLUTION 1:** The walls, the door, the floor and the ceiling contain vacuum, either by large portions or numerous small areas. The wizard can not traverse vacuum because the inside pressure of his body will blow off his vines. **SOLUTION 2:** The walls, the door, the floor and the ceiling contain liquid Hydrogen, either by large portions or numerous small areas. The wizard can not traverse liquid Hydrogen because his body parts and muscles will cease to function when frozen. Of course, we are talking about advanced medieval technology, the one when some have "magical" powers and sedating drugs are perfectly well processed so not to kill the patient. Also, the fellow alien civilization colleagues of the wizard must not know where their pal is locates so they can not extract him with teleportation means, as they hunt him for his intrusion in other civilizations history without official contact. Maybe his powers looks magical for us, Terrains (and the people from that Earth-type planet), but, in fact, we just do not have the technology to take advantage of the fact that the matter is only 1/1^18 of the volume is occupying. But, hey, luckily quantum physics is the same either in vacuum and close to 0°K. [Answer] This feels a lot like <https://xkcd.com/538/> with some “Fixed fortifications are a monument to the stupidity of man.” ~ George S Patton mixed in. It's very difficult to design a cell such that a non-wizard can't ever break out given enough time (and nothing else to do!). Plus there's always the chance of loyalists breaking in.. There's only one wizard and the sort of folks who can capture wizards can afford a few guards. Watch him at all times and if he moves outside the designated circle poke him with a stick. [Answer] All the answers so far seem overly complicated; why not just keep the wizard in a permanent coma? To trap the Wizard you only need to drug him, then medically induce a coma. (Depending on the time period the "medically" part could be fairly sophisticated or just a "heavy bump to the head whilst sedated" :>) Some drugs manufacturers even claim to have drugs that can suppress dreaming so the chance of the Wizard accidentally dreaming a spell can be reduced. And if the trap is going to be made even more dastardly, then the wizard could be made to dream, except in his dream world he is a being of non-wizardly powers. EDIT: Interrogations would be difficult if the Wizard would need to be woken up each time and the risk there is that the Wizard could use that opportunity to escape. But in a world of Wizards (or even advanced aliens walking amongst humans) perhaps another "Wizard" could be found to help? Then through one wizard manipulating the dreams of the other, interrogation could be accomplished. [Answer] Feed the wizard an incurable poison, but for which you know the temporary daily antidote. Wizard now needs you to give him his fix every day, or else he dies. If the wizard does try to escape, he will not get very far! In other words, you are *not* trying to impose the imprisonment on the wizard by an action, nor even by threat of action, but by threat of **in**action. If you fail to provide him his counteragent dose, he will die. Even if the wizard can find and kill you, if will not save him. [Answer] In a space station, or cage suspended in a chasm. Being magical, the suspension can be without ropes or anything to climb up. Can he fly too? Finding out the exact blend of talents is critical to keeping him imprisoned. If he held back some minor talent, he might be able to puzzle his way out. The captor will assume the most useful escape-relevant talents, so the wiz would come upmwith something esoteric to hold back. [Answer] Here's an idea I got from playing tower defense games: Build for your wizard a small cottage in the center of a totally flat, large square field. At each of the four corners, build a guard tower. These towers will have braziers that can be lit at night to illuminate the entire field. Each tower will be manned by some of the best crossbow snipers in the kingdom, working in shifts. The bowmen are given orders to shoot your wizard should he stray a certain distance from his hut. You can then put the mage to work. He must dig and build a well for water and construct a privy. Provide him with materials to plant and maintain a garden. Perhaps building something will give this villain some measure of dignity and contribute to his rehabilitation? At any rate, he will soon be self-sufficient and no burden on your medieval society. He will also be utterly unable to escape because he is being watched 24 hours a day. Anyone wishing to visit or interrogate him (with the king's approval of course) can do so easily. [Answer] You can do what we do today - put the prison in the middle of nowhere. There doesn't even have to be walls or guards. Let him escape - but, he can't travel forever without dying of thirst or hunger. So if his only food source is at the prison site, he cannot escape (unless he steals some food, but then you ensure he doesn't by feeding him little and under supervision). We build prisons in the middle of wildernesses - if convicts escape they are quickly found, but if they didn't, they'd die of exposure in most cases unless they returned of their own volition. Or, if he can't fly - put the prison on top of a tall, sheer, tower that is only accessible via a lift system. [Answer] Simple- three guardsman with knives on his throat with round the clock guard. If he blinks strangely slash him. You haven't indicated that he has any powers that will stop cold hard steel killing him or that he has mind-control. If he has easy mind-control then how did he get captured at all. No Dragons and Dragon's wizard could survive that- magic takes time and words. Then you put him in any old normal cell. [Answer] Break him (1984 style). Demands quite the amount of effort but at least once it's done, you no longer have to worry about him escaping or being rescued etc... But he is not maimed. In all likelyhood he can still do magic. To keep him out of harms way (from the people he's harmed himself) you "imprison" him in an isolated location with a caretaker (minimum or no security) The problem with all the fancy prisons is that sooner or later someone (maybe himself) will come up with a way to free him. Then again, maybe the escape is the outcome you're after in the long run. Another interesting idea I do not believe anyone mentioned. If you blind him, how is he supposed to know what direction to run away in? (I just prefer the blinding to breaking hands and limbs and stuff because it makes him physically okay but entirely dependent on others? Or so the jailors may think?) [Answer] Two more solutions: **Take away the oxygen** The complexity of the prison seems to depend on how far he can go holding his breath. Well, one scenario is you reduce how much breath he can hold. How about lining his prison with fires, not enough to kill him, but enough that his breath isn't oxygen rich. Then you have the added benefit of torturing this hated man. **Spikes, spikes!** Solid walls/underground is no fun, you can't see the man. Give him an iron bar cell in an open field, and fill the ground around with spikes nasty enough that he really doesn't want to be standing on them when he runs out of breath. [Answer] If they don't know magic better than he, they cannot be sure whatever they do. Some drastic measures could stop him, but you never know. So maybe: Trim him a bit. They want to keep him alive, so he needs head. But what he needs hands for? He can laye on cold floor and be periodically fed. What he needs hands for? He can lie on cold floor and be periodically fed. He even does not need arms. And if he dies from wounds/infection/sores from long laying, its his problem. But better would be hang him, boil him and quarter him (like they did in history with much less problematic persons) [Answer] Simple: Just tie him with a rope more than 10 meters from the ground. Pass the rope by a sheave, and in the other edge just put a rock with the same weight of the mage. If him try to pass by the rope or something, the weight change and the rope will fall with him. If he fall, he will die when touch the ground or passing the ground. ]

[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. **Edit:** It has been suggested that my question is a duplicate of [What could humans do to render the earth uninhabitable?](https://worldbuilding.stackexchange.com/q/6515/40609). That question only asks what would be necessary to make human life impossible. That is ***much simpler*** than what I'm asking and every answer is geared only to that limited scope — and are, therefore, unsuitable to answer this question. No amount of time or editing of that other question (unless you change the OP's intent, which is forbidden by SE) will change this state. I suspect someone read the title to that other question (but not the question itself) and jumped to a conclusion. Nevertheless, *vox populii.* --- **The year: 2025** **The goal: Kill the Earth** * "Kill the Earth" means the Earth is no longer capable of supporting life of any kind. The only possible way for life to grace the planet again is through the reintroduction of life from an outside source or through the same serendipity that brought it about in the first place (if that's even possible on a planet this old). * "Kill the Earth" does NOT mean the orb, sphere, lump-of-dirt-and-molten-metal of the planet is destroyed. That would be "overkill the Earth," and that's not what we're talking about. * Only technology that can be justifiably developed by 2025 may be considered. * The planet's death must be intentional. Unintentional side effects of living life are not allowed. For example, whether you prefer the phrase "climate change" or the phrase "global warming," *neither* is acceptable as a method of killing the planet. I believe neither apathy1 nor detachment2 meet the mandate of intention.3 * However, the *reason* for the death of the planet is NOT being considered here. In other words, I don't care if it's war or some evil genius. I'm hoping to understand if it's possible, given tech available on or before December 31, 2025, to kill the planet. However, if you just can't stand addressing the question without a premise, assume the nations of the Earth failed to pay Ernst Stavro Blofeld his ransom. Whether you think it can be done with enough nuclear weapons or bubble-gum, you need to justify just what it would take. * The planet must be dead within a month of acting on the intent to destroy the Earth. * I'm using the [hard-science](/questions/tagged/hard-science "show questions tagged 'hard-science'") tag because I'm not interested in, "well, this might work" answers. Back it up or pack it out. **Question:** Is it possible before the end of 2025 to destroy all life on Earth within a 30-day period per the above requirements? --- 1 *The tendency to consume resources and pollute in a thoughtless, even oblivious manner. It isn't that the individual* wants *to kill the Earth, it's that he/she doesn't care that they're part of the problem. Indeed, they don't even care to discover if they are part of the problem. The entire issue rolls off their back like water on a duck.* 2 *On the other hand, this is the kind of person who honestly believes they're not killing the planet and would never in a million years agree that they are killing the planet — but see no reason why they shouldn't be allowed to dump chemical waste into a river. After all, it needs to go* somewhere, *and it costs too much to recycle it. More jobs are to be had if the cost is avoided! Like the job of scraping the barnacles off my new 60' yacht! So such a person deliberately dumps — but isn't actually* trying *to kill the Earth.* 3 *The biggest reason for this condition is that almost anything could destroy all life on the planet, like a meteor, but I'm not interested in natural phenomenon, like meteors, or "consequence of living" phenomenon which may or may not kill everything (but likely won't, and hasn't in the last 50 years anyway). I want to know if there's a way to extinguish it. Frankly, I'm not convinced using all the nuclear weapons from the height of the Cold War would do it, which is why I'm asking. Honking cockroaches.* [Answer] # Not with the time constraint given. Let's start with the most destructive thing we've got: nukes. There are about 15,000 nukes worldwide, of varying yields. Sources: 1. [World Nuclear Weapon Stockpile, Plougshares Fund, 2018](https://www.ploughshares.org/world-nuclear-stockpile-report) 2. [Federation of American Scientists, 2018](https://fas.org/issues/nuclear-weapons/status-world-nuclear-forces/) Assuming an average yield of 200 kilotons, which is what most US nukes have, we could assemble them all up into a framework to allow for a blast of approximately three gigatons. Source for the average yield of an american bomb: 3. [United States nuclear forces, Bulletin of the Atomic Scientists, 2018](https://www.tandfonline.com/doi/pdf/10.1080/00963402.2018.1438219?needAccess=true) That is about 15 Krakatoa explosions. Source for the estimated output of the Krakatoa volcano: 4. [Krakatoa - Historical significance (Wikipedia article)](https://en.wikipedia.org/wiki/Krakatoa#Historical_significance) If 15 Krakatoas went off at the same time around Earth, we might have more than enough dust in the atmosphere to block sunlight for some time. That would cause a huge and relatively quick extinction event. But lack of light did not end all life 65 million years ago. It would not end all life nowadays either. # What if we dial it to eleven, then? The amount of uranium in the Earth's crust that is accessible to mining approximates to 35 million tons. Source: 5. [International Atomic Energy Agency: Global Uranium Resources to Meet Projected Demand, 2006](https://www.iaea.org/newscenter/news/global-uranium-resources-meet-projected-demand) If we mined it all, and used it all for nukes and nothing else, we could have a set of bombs strong enough to achieve about the same yield as the impact of Chicxulub. Source: 6. [Bralower et al. Geology 26(4) 1998](https://web.archive.org/web/20071128093102/http://www.geosc.psu.edu/people/faculty/personalpages/tbralower/Braloweretal1998.pdf) (PDF download) So we got an extinction event on our hands, and on steroids since this one also makes the whole surface of the Earth radioactive. While this is enough to make Imagine Dragon's *Radioactive* the theme song for the planet, it will fail to wipe out all life on Earth just like Chicxulub did. The impact will be survivable for a lot of creatures, and the radiation will only immediately kill those at the surface of the Earth or closer to it (in the case of marine creatures). Water is a great radiation shield. You can swim in a pool of spent nuclear fuel with impunity. Source: 7. [XKCD What If issue 29 - Spent Fuel Pool (Munroe, 2013)](https://what-if.xkcd.com/29/) The creatures at the depths of the ocean will be mostly unaffected until enough radioactive material actually makes it to them, which may take more than a month. # Life always finds a way anyway Last but not least: some lifeforms actually thrive on radiation. Consider the collapsed reactor of the Chernobyl Nuclear Power Plant. The amount of radiation in there is enough to kill most living beings in short time, yet a species of radiotrophic fungus thrives in there. Source: 8. [Ionizing Radiation Changes the Electronic Properties of Melanin and Enhances the Growth of Melanized Fungi, 2007](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1866175/) You might kill a lot of things, but some lifeforms would remain. The goal you wish just cannot be achieved in such short time. --- **Edit:** as Nicolai pointed out in comments, there are bacteria living several kilometers underground - and they use uranium in their metabolism, so even if the radioactivity makes it to the underground, the microbes may actually benefit from it. Source: 9. [Bacteria Found Nearly 2 Miles Undergroun (Live Science article by Sara Goudarzi, 2006)](https://www.livescience.com/4229-bacteria-2-miles-underground.html) --- **Edit:** WhatRoughBeast and Denis de Bernardy have also reminded that this beast has been found way deep underground: [](https://i.stack.imgur.com/AvmLm.jpg) This is the [Halicephalobus mephisto](https://en.wikipedia.org/wiki/Halicephalobus_mephisto), a 0.5mm long nematode that has been found living 3.6km below the surface. It too would probably be largely unaffected by whatever disasters that wreck the surface of the planet. --- [Answer] No. Most of the preceding responses have overlooked one relatively-recently identified home for life on the planet; within the crust itself. Researchers have found bacteria up to [4 kilometers down](https://www.the-scientist.com/features/life-thrives-within-the-earths-crust-64805) in continental crust and 2 km beneath oceanic crust. Recent estimates are that up to [70% of the microbial life on the planet is](https://www.independent.co.uk/news/science/deep-life-microbes-underground-bacteria-earth-surface-carbon-observatory-science-study-a8677521.html), in fact, in the deep biosphere. That being the case, in order to sterilize the planet you'd need to heat the crust so that the heat penetrates down far enough to ensure there was no space between the hot rocks above and the hot rocks below for any life to survive. To do it quickly means dumping so much heat into the crust to allow it to work it's way down that you're almost certainly talking about creating a magma ocean on the surface. There is no human technology capable of this, and will not be by 2025. While, theoretically, you might be able to slowly shift the orbit of, say, the Moon to do it through impact (and I'm not sure even that will be enough), it's not happening within 6 years. [Answer] Well, the one thing that life needs on Earth (and pretty much anywhere else depending on how extreme your xenobiology is) is water. Now, we're not trying to boil the ocean here but... No wait. That's **exactly** what we need to do. Let's start with how much water that is to boil. We're talking about [1.26 x 1021](https://science.howstuffworks.com/environmental/earth/geophysics/question157.htm) litres of the stuff. That's a lot and is going to need a lot of energy to boil off. Exactly how much? Well, it takes approximately [4200 J](https://www.bbc.com/bitesize/guides/z2gjtv4/revision/5) to heat a litre of water by 1 °C, so it will take around 420 kJ to heat it by 100 °C. Now, I know this is a simplification, and you're going to say things like 'Hey, the water on earth is warmer than zero degrees' and 'Hey, that doesn't account for the energy used in state change for ice at the poles' and 'Hey, what about pressure differential at the bottom of the ocean?' etc. and you're right; I'm over simplifying but for the purposes of an answer that doesn't blow the field limit of the answer box, let's just assume that *on average* we're going to need 420 kJ per litre of water on Earth to boil it off. In practical terms, that means we're going to need 5.292 × 1026 joules to boil off the ocean. But that's just for starters; what we *don't* want is that water condensing again, so we want to keep up a supply of joules to basically keep it as steam in the atmosphere. But we'll get to that. There is no such thing as an average nuclear reactor, but the largest one in the US is capable of generating [just under 4 MW](https://www.eia.gov/tools/faqs/faq.php?id=104&t=3). Let's assume that we're building reactors half that size and we have a reactor that can reliably produce 2 MW of power 24/7. That is the equivalent of 48 GWh a day. Now, 1 MWh = 3.6 × 109 J meaning that our nuclear power plant can generate 1.73 × 1014 J. Extending this further, we need around 3 × 1012 power plants to do this work in a day. But, we have a month! So, dividing by 30, we now only need 1011 power plants to do it. The good news is that for that month, we're only going to need [4.5 tonnes of nuclear fuel](http://www.world-nuclear.org/nuclear-basics/how-is-uranium-ore-made-into-nuclear-fuel.aspx) per power plant to do this, although we may need more later to keep the water as steam for an unspecified period of time. But here's the thing; the world becomes unlivable because of the ambient temperatures well within the 30 days, so all 'complex' life is already dead. Most of the simpler life is either struggling or dead as well, so let's assume that we only need fuel for our 30 days. According to some sources, there is only around [40 trillion tonnes](https://en.wikipedia.org/wiki/Peak_uranium), or 4 × 1010 tonnes on the planet today, which works out a little less than 10% of what we need to do this (1011 reactors times 4.5 tonnes of fuel). But, it's not 2025 yet! And there's another source of heat that we can potentially tap; the earth's mantle. It is already estimated that the leakage of heat from the mantle is around [47 TW](https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget), and we can accelerate that through deep core drilling. Essentially, we want to drill a whole bunch of deep holes around the earth, right down to the mantle and let out the lava. This is already a thing, and geothermal energy producers are already getting output [that rivals some nuclear power plants](http://theconversation.com/magma-power-how-superheated-molten-rock-could-provide-renewable-energy-67725). In practice this means that we can generate 10% of the power through nuclear, and between now and 2025 invest a lot of money into geothermal research and drill deep holes that generate the other 90% of the heat we need through tapping into the earth itself. This secondary (actually, primary given it needs to comprise 90%) method of heat generation has an added bonus; it's likely going to destabilise the tectonic plates as well given the number of holes we're going to drill. In any event, the point is that life dies without liquid water. If we want to deliberately destroy life on this planet in 2025, the only thing we need by then in terms of tech is drilling technology; we have everything else we need, and we also get to do the one thing I keep getting told I'm not allowed to do on my regular projects; Boil the ocean. [Answer] **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. **No** Within a month period is impossible. The only event realistically capable of wiping out all life that quickly is a [meteor strike](https://en.wikipedia.org/wiki/Impact_event) and you can't get to any asteroid big enough in that time frame let alone get it moving and back to Earth. Scientists estimate it requires something of at least 100km diameter for an extinction level event. The [Chicxulub](https://en.wikipedia.org/wiki/Chicxulub_impactor) impactor was 11 to 81 km and only wiped out the dinosaurs. > > In the early history of the Earth (about four billion years ago), > bolide impacts were almost certainly common since the Solar System > contained far more discrete bodies than at present. Such impacts could > have included strikes by asteroids hundreds of kilometers in diameter, > with explosions so powerful that they vaporized all the Earth's > oceans. It was not until this heavy bombardment slackened that life > appears to have begun to evolve on Earth. > > > [Wikipedia](https://en.wikipedia.org/wiki/Impact_event) > > > Bacterial life is extremely hard to kill You need a longer timeframe or perhaps settling for killing higher life forms? (Which in a month would still be virtually impossible) [Answer] TL;DR: We are unable to kill all life even in a tiny piece of medical equipment. Don't expect us to perform better at killing all life on the whole Earth. We are already trying hard to kill all life in limited settings and with all the might of 2019 technology there is always something remaining. For example, in high-risk applications, we we [don't try to remove the last millionth of microbes](https://en.wikipedia.org/wiki/Sterilization_(microbiology)#Quantification). Of course, when killing all life on Earth we have the advantage that preserving it is not a requirement and we can go with more destructive methods than for medical equipment. However, even with lots of nukes, the size of the crust and the oceans makes any large scale sterilizing method less powerful than any industrial standard to sterilize smaller objects. [Answer] # Grey Goo One possible way that life on the planet could be extinguished is a [Grey Goo](https://en.wikipedia.org/wiki/Grey_goo) scenario. Some kind of self-replicating nano-machine that indiscriminately consumes bio-matter could in theory wipe out all life on the planet, and assuming it propagates at 8 m/s (assuming I did the math right) it could entirely encompass the earth in a month. This assumes of course there's no built in failsafe, and it has expanded to a large enough area that it can't be stopped with conventional explosives, and or nukes. This also assumes it is only started in a single place. Even with a slower propagation rate, if it was released in multiple places around the globe simultaneously it could still suffice to end everything. It's worth noting that while a Grey Goo scenario could become unstoppable, in all likelihood it would propagate at a much more sedate pace. # Math section Circumference of Earth: 40,075,000 meters Seconds in a month: 2592000 8 \* 2592000 = 20736000 (half the circumference, since it would be expanding in all directions). [Answer] ### < How to kill a Tardigrade > Life is stronger than many people may have expected. For some, unless you nuke them on the head, they'll survive most world destruction events. One example is Tardigrade. Known to have cyptobiosis, they can suspend their metabolism. They can survive under extreme environments that would kill almost any other animal. (mostly from wiki) * Low temperature: few to days at 73K, few minutes at 1K. * High temperature: few minutes at 151°C. * Extreme pressure: vaccum of open space and solar radiation combined for at least 10 days, or more than 1200 Atm. * Dehydration: survive 10 years of dry state. * Radiation: Tardigrades can withstand 1,000 times more radiation than other animals. While their average life span is only a few month, they can be dehydrated to skip a rather long time period, so they can just chill and wait until the "kill" is over. And there are bacteria that live undersea (3,650 meters) and withstand extremely high temperature (121 Celsius). I highly doubt if you can damage them effectively, let alone eliminate them. Given the time restriction you set (year 2025), no I don't think it is possible to kill ALL life on earth. [Answer] **Supervolcanos** Supervolcanos are bad things. Very bad things. One supervolcano can qualify as a global catastrophic risk, creating a layer of ash in the sky across a continent, and a theory places a global winter 75,000 years ago as a result of one. Now, one supervolcano can't guarantee an extinction level event. Well, that's one. There's more than one, though. A supervolcano, by definition, is anything that can qualify as a class 8 Volcanic Explosivity Index. And, from a few searches on the subject, there's around a dozen potential candidates scattered around the globe. Plus a few Class 7s, which aren't really extinction level events, but we might as well add them to the fire anyway. Then we get to the main problem - triggering this event. This one's fun. Now, we've got two ways of doing it. The first is to just nuke it repeatedly until it explodes. (Like, maybe ten nukes to a supervolcano? Followed up by a few hundred round of conventional warheads, like MOABs. That seems like a reasonable number.) Now, I'm not sure if it'll work. In fact, I'm fairly certain that this won't trigger a conventional volcanic eruption. But you'll definitely get all that nice red-hotlava and ash, and hopefully the force of the explosion will scatter in to the winds. The second way of doing things is hiring a geologist and using seismic charges to manipulate the crust. You'll probably need sizable charges, maybe even a few nukes, but this time strategically to trigger the volcano, rather than brute force. I am not a geologist, so my knowledge ends here, but there should be a way to set something like that up, given a few hundred nukes and five years to dig. In either event, what you end up with is an ash-shell in the atmosphere, thick enough to block all sunlight and the heat that comes with it, choking life as we know it. Within days, the Earth becomes a horrific hellscape of either frozen barren wastes, or lava-choked scorched Earth. To clarify, there will be a few humans who survive past a month, presumably some important people with bunkers, or something of the like. But the Earth is done for. You'll have to wait for it to reset. [Answer] Since there are no practical "yes" answers I'll give a partial answer--meets everything but the 2025 requirement. Send a mission to the asteroid belt, they're carrying a big load of nukes. The objective is to use them as an Orion drive to divert an asteroid towards Earth. Blofeld does the "burn" while the asteroid is behind the sun so no pesky astronomer could notice what's going on. After the burn is done the asteroid is painted black so it's not going to be noticed as it comes down. It's aimed for a barely grazing trajectory. As it approaches Blofeld makes his ransom demand--pay up if you want the crew to use the last of their nukes to nudge it into a near miss rather than a grazing hit. Orbital mechanics waits for no man so there can be no delaying tactics with the negotiations. One month from impact is the last point where they can nudge it away without simply shattering it instead. The science: Orion is going to take a lot of engineering but all the principles have been proven to work. A chemically powered version has actually flown a short distance and objects have been demonstrated to be able to survive in close proximity to a nuclear detonation. Blofeld will deliberately choose an asteroid with no structural strength to ensure Earth can't simply use massive numbers of bombs. If you thump a rubble pile it's basically going to come apart. Some bits will be lost but so long as the thump isn't too hard the self gravity of the bits will bring them back together. This is a slow process, though, limiting the rate at which you can thump it. Thump it too hard and fast and it flies apart--now you have a great collection of rubble that you can't hope to divert. It will still deliver just as much energy when it hits, though, and the objective is that energy, not the destruction of the impact. Note that the engineering is probably going to be done in the not too distant future. Delta-v doesn't care if it's used for good or bad, the exact same technology could be used to divert a rock that threatens Earth and the ability to move asteroids this way vastly exceeds any other proposal out there--when time is short there will be no other option. (Not to mention every other asteroid deflection technique requires rendezvous, Orion doesn't. So long as the guidance unit is good enough you merely need to get the bombs to the desired standoff range, it doesn't matter if they're doing a head-on approach.) [Answer] I don't think it can be done in any way imaginable save for complete physical destruction of the planet. Bacteria are essentially impossible to kill. So, a possible extinction-level event that would kill anything big and possibly eventually a lot of bacteria too: "Sun shade" around the Earth. Just make eternal eclipse. No sun = no life. Eventually. I believe extinction-level event will happen within a month due to mass die-off of stuff requiring sunlight. Actual complete extinction will not be even close in that time frame and you might not wipe a single species if you turn the shade off after just a month - it will just look like extinction happened in a month due to massive die-off at that time. (you can achieve sunblocking effect with volcanoes/meteors, possibly nukes to some extent, but this manmade shade looks more in spirit with the question demanding purposeful trigger of the extinction) Now, what about bacteria? As another somewhat related SE question asked (<https://biology.stackexchange.com/questions/23050/organisms-using-thermal-energy-as-their-sole-energy-source>), there are bacteria that live ONLY on heat, so even if you turn off the sunlight "forever", these will survive until Earth cools down. Now, how long will it take before Earth cools down completely because we cut off the sun - well, assuming Earth is rock-ish, we have 1 kJ/kg\*K and its size gives about 10^27 J/K. Well, if I didn't screw up several orders of magnitude. We have about 10^17 W incoming from the sun that keeps Earth in heat balance and that is now gone, so we have 10^17 W of cooling. We are looking at 10^10s/K = about 30 years to drop a single degree. Note that the surface will cool much faster than the interior, but at the bottom of an ocean trench it will still take a while before those bacteria die off. [Answer] **A strangelet could do the job** Of course it is not hard science, because these things are (still) only theoretical and a doomsday scenario would require that some assumptions are right. According to the [wikipedia](https://en.wikipedia.org/wiki/Strangelet) page about stangelets > > A strangelet is a hypothetical particle consisting of a bound state of roughly equal numbers of up, down, and strange quarks. An equivalent description is that a strangelet is a small fragment of strange matter, small enough to be considered a particle. > > > and > > If the strange matter hypothesis is correct and a stable negatively-charged strangelet with a surface tension larger than the aforementioned critical value exists, then a larger strangelet would be more stable than a smaller one. One speculation that has resulted from the idea is that a strangelet coming into contact with a lump of ordinary matter could convert the ordinary matter to strange matter.[15][16] This "ice-nine"-like disaster scenario is as follows: one strangelet hits a nucleus, catalyzing its immediate conversion to strange matter. This liberates energy, producing a larger, more stable strangelet, which in turn hits another nucleus, catalyzing its conversion to strange matter. In the end, all the nuclei of all the atoms of Earth are converted, and Earth is reduced to a hot, large lump of strange matter, the size of an asteroid. > > > So, if someone has enough resources to build the most powerful particle accelerator in the world in 6 years (1), and some theories prove to be correct, he could trigger an end-of-the-world scenario with the total destruction of life on Earth.(2) (1) Note that if the purpose is the destruction of the world, it would be relatively quick to build, since the biggest part of the work in projecting and building an accelerator is to be able to perform experiments, which would be useless in this case (2) But of course, even given a powerful enough accelerator, the possibility that such thing could happen in real life are in the range of "win the national lottery 100 times in a row" [Answer] # ATMOSPHERIC INTERVENTION ## without protection, everything will face judgement It's entirely possible, however, it's not a "Noah's flood". Things will die slowly, but completely. **Location** This is important, as you'll need a thick, forested area where there is plenty of foliage. I recommend the American/ Canadian Midwest, or the vast, low-population Russian forests. **Preparation** The goal here is to strip the atmosphere of all protective qualities. This means that we have to reach a global supercritical temperature, where the earth becomes so hot it strips itself of an atmosphere. How hot is that? An average day temp of 100C will slowly ebb the oceans away, and once the oceans are gone, life will go. You'll also need to stockpile Flourine. [The world puts out 5,000,000 Tons of Florine a year](https://en.wikipedia.org/wiki/List_of_countries_by_fluorite_production). Let's say that we put 1/2 of that (in the 10 year span) towards destruction, or 100,000,000 Tons. Let's put the entirety of that into [carbon tetraflouride](https://en.wikipedia.org/wiki/Tetrafluoromethane), where 1 molecule of said compound has the effect of [7350 molecules of CO2](https://en.wikipedia.org/wiki/Global_warming_potential), and lasts many times longer. We can do better, though. [Sulfur hexaflouride](https://en.wikipedia.org/wiki/Sulfur_hexafluoride), most notable for the deep voice it gives you upon breathing it in, is 400% more potent than Flouromethane, with only 50% more cost (sulfur quantity availability is much more than Florine). On top of that, it's atmospheric lifetime is 3,200 years, so it's rather static. With 100 megatons of Florine, that comes out to the equivalent of 1.986 *Tera*tons of CO2 for the first 20 years. To compare, our CO2 output estimate for 2018, that's 50 years of CO2 output in a few moments. That's not enough, maybe to kill all land animals, but not most creatures in the sea. See, Sulfur hexafloride just heats the planet, there is still protection provided by the atmosphere. For that, we're going to use a different compound: [Halon 1301](https://en.wikipedia.org/wiki/Bromochlorodifluoromethane). This chemical is used in fire extinguishers to fight chemical fires, and we could reasonably produce 1.81 million tons, given the limited capacity of Bromine production of 250,000 tons per year. This is capable of eliminating 1,310 megatons of ozone. Compare the 1.81 million tons figure with the [790 tons of 1301 released in 1997](https://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/halons). Releasing this quantity of 1301 would be the equivalent of 2291 years of pollution (we used CFC aerosols for 50 years). **The event** Here's a prediction from NASA of of the ozone concentration if we continued using CFCs for another 60 years: [](https://i.stack.imgur.com/Ngj4P.jpg) The damage above would be only 5.24% of the total possible damage such an event would cause. With ozone being out of the equation, Ionizing radiation is much more common on earth now, along global warming being 50 years more advanced. by no accurate calculation, I'd estimate a global temp increase of about 15C because of the Sulfur release alone. **The atmosphere is now toxic** Normal life cannot exist using the atmosphere for air, as ionizing radiation can now liberate atoms from the surface to create spontaneous gasses. **The Oceans are now toxic** As the atmosphere befalls to this, so does the ocean, and oxygenation from algae is no longer possible. **The Oceans are now super-salinated** As water evaporates off in extreme heat, the concentration of salts and minerals in the water skyrockets, killing off most creatures. **The surface is now dust** eventually, all non-human land creatures succumb to drought or kidney failure. what's left of the surface is inorganic structures, and dust. **The ocean is nearly uninhabitable** With the exception of extremophiles, all life in the ocean is gone. **Humanity's final Hurrah: The nuclear anthem** with all food being gone except twinkies, humanity decides it's time to set off the nukes (though the nukes were on a timer since you released the gas). They launch and race into the plasma that's shortly above everyone's heads. With all nuclear bombs at hand, the major targets are: The Chile super volcano, The Wyoming super volcano, and a few more in the Philippines, along with any remaining human settlements. With a little luck, over 15,000 cubic kilometers of mass, or 0.00000178% of it's total mass, but that figure isn't important, what is important is that the mantle now has open ejection channels, and that the crust, is more or less, sinking, and weakening the magnetic field of the earth. eventually, the earth turns into a clone of Venus, with acid rains, slowed days, extreme heat, and most importantly, no life. Even the extremophiles have no means of reproduction, as their environment has changed so much. a sterile planet. edit: This is not a 30-day extinction event, but rather an event in 30 days that tips the dominoes towards impending doom. It's unlikely that anything would go extinct as a result of the events in the first 30 days. [Answer] **Mass Extinction** Life on Earth has recovered from five mass extinction events. Definition: more than 75% of species become extinct. The closest life came to being ended completely was "the great dying" of the late [Permian mass extinction](https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event) which eliminated 96% of extant species and nearly ended life completely. In this 20,000 year period a huge volcanic eruption in Siberia released large amounts of CO2 into the atmosphere. Methanogenic bacteria thrived from this CO2 plume and began contributing large amounts of methane [another greenhouse gas] into the atmosphere as well. Global temperaturs rose and oceans acidified, losing oxygen and killing fish life. This in turn released hydrogen sulfide or H2S. H2S displaces oxygen and is highly toxic to aerobic life. It was in short a radical transformation of our atmosphere and oceans to a point where they no longer supported the vast majority of extant species. As to how you could do that *on purpose* using existing man-made technology? I don't think you can. Technically we are in the anthropocene 6th mass extinction, where the cause is human activity but even at our worst we aren't recreating the conditions of the Permian event. Volcanism releases far more CO2 naturally than we can on purpose and to get a bloom of methanogenic bacteria and possibly oceanic algae blooms all synchronised at once.. you'd need to know when an eruption as bad if not worse than Mount St Helen was going to occur and have stocks of the bateria ready to disperse. If you knew a way hands down to cause a volcanic eruption that bad you'd be close but it would certainly take longer than a month. [Answer] You could make a snowball earth using environmental chemistry, make the sky dark and kill 99% of the planets land and sea animals, but it would be difficult. Humans can make nuclear bombs 10,000 to 20,000 times Hiroshima for every bomb. Each bomb could take the worlds temperature down 1'C, if you buried it somewhere where it generates atmospheric ash, so you can potentially cool the planet by 100'C. Krakatoa took the temperature down 1.2 degrees, and it was only worth one human megabomb, i.e. 3 Tsar bombs. If you can lift 1000 cubic kilometers of ash into the air, that's already at least 20'C or 30'C degrees drop in temperature. Humans should be able to lift about 10km3 with every bomb, so you'd need at least 100 bombs. There is a lot of ash in Indonesia, Hawaii, and other archipelagos. If you made as many atomic bombs as man can make, say a thousand of them, in the time given, and bury them all in places with dark ash, coal, volcanoes, you can probably trigger a darkness and nuclear winter which would destroy most of the plants, land animals and fish. After that, the small mammals, insects and mushrooms will always survive for at least a few hundred years. You could also try to manufacture botulin and sarin gas and other toxic hyper-variants in billions of tons, and combine both a snowball earth and the chemical warfare, but it would only give the planet a brief sleepy period, and then it would bounce back as good as new. [Answer] ## Push the earth closer to the Sun! I came up with this idea that may achieve that evil goal, with current technology and billions of rocket engines, in 117 years; although that doesn't suffice the requirement, I'd like to discuss with people to see if there is a better approach. The basic idea is: using rockets to decelerate the earth so that it will get closer to the sun. As it gets close enough, I expect the "pale blue dot" becomes a "bright red dot". If the whole planet becomes (almost) a lava orb, **I don't think any life-form can survive that** - and no, it's not destroying the earth, so definitely not overkill. Earth just returned to a form 4.5 billion years ago. A slightly detailed version: * I plan to use [Saturn-V](https://en.wikipedia.org/wiki/Saturn_V), the most powerful rocket in human history. * I will use [Hohmann transfer orbit](https://en.wikipedia.org/wiki/Hohmann_transfer_orbit) to move earth between two orbits. That's when I realized we can't achieve this plan in a timely manner. * I want the new radius to be 0.1 [AU](https://en.wikipedia.org/wiki/Astronomical_unit). Apparently, Mercury at 0.3 AU is not hot enough for project lava orb (700 Kelvin). ### Math time: **some constants** ``` # AU distance, m au=1.496e11 # Gravitational constant, m^3*kg^-1*s^-2 G=6.67408e-11 # weight of the earth, kg M=5.972e24 r1 = au r2 = 0.1 * au mu = G * M pi=3.14 F = 3.3e7 ``` **How long does it take?** According to Hohmann transfer orbit wiki page (yup, just learned this 5 minutes ago), this process will take 117 years to make the orbital transfer ``` t_h = pi * ( (r1+r2)**3 / (8*mu) )**0.5 # 117 years ``` **What is the change of speed in each process?** Hohmann transfer requires a two-step speed change. Delta\_v of each process is surprisingly small - 29m/s and 56m/s decrease in speed. ``` delta_v1 = ((mu/r1)**0.5) * (((2*r2)/(r1+r2))**0.5 - 1) # -29.6 m/s delta_v2 = ((mu/r2)**0.5) * (1 - ((2*r1)/(r1+r2))**0.5) # -56.9 m/s ``` **How can we achieve that!** I plan to use Saturn\_V (with Rocketdyne F-1 engine), THE rocket that sent Apollo XI to the moon. I disregarded the time needed to construct and assemble these rockets. Assume we have precisely one year for the first deceleration and the second deceleration, how many Saturn\_Vs do we need to ignite at the same time to achieve the Hohmann transfer? ``` burn_1 = (M * -delta_v1) / (F * 86400 * 365) # 1.7e11 burn_2 = (M * -delta_v2) / (F * 86400 * 365) # 3.3e11 ``` Whoa! 170 Billion and 330 billion rockets, not including the amount of kerosene fuel wasted in this process. This will most likely tear the atmosphere into pieces, destroy the ionosphere (hello solar wind), and heat generated in this process should be able to eliminate most life forms already. ## conclusion Project lava orb will literally take hundreds of billions of rocket engines, and 117 years to push the earth close enough to kill all life on earth. This project is based on an unreliable calculation, an unrealistic waste of resources, and 20-century technology. But hey, we did it! [Answer] The best way to answer the question, assuming the means of extermination is by nuclear bombs or other similar weapons of mass destruction is to compare what is being sought for with what has actually happened in the past. Since life is still on the Earth, then this gives you a lower bound on what is required. Yellowstone's volcano was about 875,000 megatons when it last went up. The dinosaur comet was about 100,000,000 megatons. TNT Equivalent (with list of examples): <https://en.wikipedia.org/wiki/TNT_equivalent> Here are the most recent snapshot of bomb counts <https://www.armscontrol.org/factsheets/Nuclearweaponswhohaswhat> Russia and the US have a 6000-7000 each, everyone else has a few here and there. It adds up to about 15000. The biggest Cold War nuke was around 100 megatons, so that gets you up to a max of 15,000,000 megatons; but more likely around something like 1,000,000 megatons. That's not even scratching the surface. It barely even matches Yellowstone. You have a long way to go. In contrast, take a look at what happens (according to Universe Sandbox 2) when our resident Evil Wannabe God-Demiurge gets into another one of his moods and puts a 1 millimeter-sized black hole next to the Earth. <https://www.youtube.com/watch?v=h3KOmt9onvc> [Answer] **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. Well... this is highly theoretical and very speculative, but I think it still qualifies as hard science. It could be possible that our universe is in a "[false vacuum](https://en.wikipedia.org/wiki/False_vacuum)" state and given the right conditions could collapse to a state of a lower energy. If this was happen to one small place, the theory is that it would spread like a "bubble" at the speed of light. You literally wouldn't see it coming. And after it has happened, the universe (in that place) would have changed with all new laws of physics and fundamental constants. Pretty sure that life as we know it wouldn't exist anymore. Heck, chemistry wouldn't exist anymore. But, as I said, it's highly theoretical at this point and we have no idea if this is actually the case or not. But it does work for a story. [Answer] It *might* be. It has been considered, as very hard science, [here.](https://file.scirp.org/Html/34277.html) Synopsis: you would need to drop a hydrogen bomb into the sun. Deep into the sun. The problem, therefore, is to avoid the bomb being vaporised before it reaches sufficient depth to start a nuclear chain reaction within the hydrogen of the sun itself. Whether a sufficient thickness of sufficiently heat-resistant ablative material might be created and delivered into the sun, seems unlikely, but I'd prefer to have seen a proof of total impossibility. (On the political/human front, it probably is impossible. How to hide your intent? It would just take one person out of many tens of thousands involved in such a project to sabotage it, and it's not as if you can test it properly in advance!) [Answer] We can try to adopt [the method proposed here](https://space.stackexchange.com/a/12764/11234) to prevent a large impact with the Earth, to let large proto-planets like Vesta or Ceres crash into the Earth, but it is unlikely to work on a time scale of just a few years. A relatively fast way could be by sending a mission to a a few comets to alter their courses to make them crash into large asteroids the size of Eros. Those collisions are engineered such that these large asteroids are sent to collide with minor planets like Vesta and Ceres in such a way that these minor planets will collide with the Earth. [Answer] This is a yes or no, open-ended question, where you specifically ask for hard science. I believe that, even though the majority have answered no, there is no way you could truly claim that it is impossible. You cannot prove a negative, as they say. That being said, I'd like to explore one particular path of action that might result in the earth being uninhabitable. Colliding the moon with the earth. I think it's safe to say that this would end all life, likely within hours. <https://www.iflscience.com/space/what-would-happen-if-moon-hit-earth/> So the big question then, is can you do it in a 30 day period? Google tells me that the energy required to stop the moons orbit around the earth is about 3.7e28 joules. That is quite a lot more than the entire nuclear arsenal of the earth. (according to google) Now, it depends a bit on what exactly you mean by your 30 day period. If you were to produce this thrust with a rocket engine (with sufficient propellant somehow) spread out over the entire 30 days, you would have to produce roughly 1e26 watts of thrust. I believe that means you would be looking at the equivalent of roughly 5e20 f1 rocket engines on the moons surface, as well as their fuel for continuous burning for 30 days, which doesn't seem particularly feasible. If you also had to take from the 30 days to manufacture, transport and install these rocket engines (and their fuel) it would be even more difficult. You would probably have to find a way to do most of this on the moon itself. Especially using the moon as propellant would help the equation a lot. I don't really know of any way to do that. So my answer is: This particular method seems infeasible. (aka no) [Answer] As other answers have pointed out, humans do not and will not have the technology to do so. That leaves non-human technology. Although you've stated that you don't want to physically destroy the Earth, considering [life in the cust](https://worldbuilding.stackexchange.com/a/147938/2044), the only way to kill all life on Earth is to essentially make the Earth stop being. Those aliens must be already en-route in order to get here by 2025. They are powerful. Very powerful. [Any sufficiently advanced technology is indistinguishable from magic](https://en.wikiquote.org/wiki/Arthur_C._Clarke). Their spaceship is planet sized, and although [25 trillion tons of antimatter](https://qntm.org/destroy#sec3) is costly, spaceship policy requires the destruction of any planet harboring intelligent life. It takes the aliens about 3 gigaseconds (~100 years) to produce such a bomb, but they've known for 15 gigaseconds that they are going to pass near enough the Earth to target it with one, and it's been many teraseconds since they last had to neutralise an entire planet (for safety and regulatory reasons, they don't stock more than a few billion tons of antimatter). They send off their 25 trillion tons of antimatter on a course to hit the Earth at 0.9c. After it hits, the Earth physically blows into pieces. Any life that isn't killed yet, will be soon by boiling, by vacuum, or by lack of water. And if any microbes survive even that, they wouldn't be life on Earth anymore. They would be life on a second asteroid belt in solar orbit. ]

[Question] [ The most commonly used word in english is "the" accounting for about 6% of all the words being used. The second most common word is "be" account for less than 1% of all the words used (see [ngram viewer](https://books.google.com/ngrams/graph?content=the%2Cbe&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Cthe%3B%2Cc0%3B.t1%3B%2Cbe%3B%2Cc0) and [wikpieda > Most common words in english](https://en.wikipedia.org/wiki/Most_common_words_in_English)) Imagine a human society where a widely spread language which most commonly used word accounts for over a third or even over half of all words being used. How could such language come to existence and how could it sustain? [Answer] Simple, make the language [Oligosynthetic](https://en.wikipedia.org/wiki/Oligosynthetic_language). Oligosynthetic languages are languages that have 50-200 words and simply combine words to create new concepts. For example; Let's say I want to say hell, in English I would say hell. In an oligosynthetic language, I would say: Inverse-help-place or hurt-place. In an oligosynthetic language, the word that inverses a word (english prefixes like A-, Un-, or In-) would occur in 50% of nouns. This is similar to what O.M suggests, but his words would appear around 30% of the time. [Answer] No kurwa Lower classes often have a curse word that can mean anything from agreement to joy to disagreement. In Polish, one word ("kurwa") can also mean, with small modifiers, drunk, angry, thrown out of a bar, and many more. If you are creating dystopia, using curse word like this can be your way. Nice to read: <https://workout4brain.wordpress.com/2015/09/07/oh-kurwa-reflection-about-bad-words-in-polish-is-it-really-possible-to-translate> - of course this barely scratches the surface. By the way, first paragraph means "isn't it obvious?". Another use of one word. [Answer] Single-line answer: > > Oook > > > * the librarian of the Unseen University, Ankh-Morpork. In Terry Pratchett's books about the discworld, there is a monkey orangutan, working as a librarian in the Unseen University's library. He had his own language, consisting entirely out of "ook", "oook" and "eeek". Though his language has only 3 words, some people from the IU understand him, because each word has many, many meanings. It all matters only on the intonation, for example "Eeek." means "No.", while "Eeek!" means "I'm not a monkey!", or "Ook" can mean "Yes.", or for example, "Give me that banana.". I actually tried doing something similar time ago with a group of ~50 people, mainly kids, on a 22-day summer camp (no phones, no electricity, no connection to civilization): I let the people choose the only 20 words they can use in the whole camp. And believe me, it did work. For example, "yes" meant two things: "yes", and "no" (when said ironically). And so on; a single word can have tens of meanings. [Answer] Assume a language where all nouns can be used as verbs or adjectives, and vice versa. There are special words to indicate the use. Those three words would be rather common. [Answer] In Thai, you end pretty much every sentence with ครับ (if you are male), คะ (if you are female) or ค่ะ (if you are female and the sentence is a question). These words don't have a translation to English and don't alter its meaning in any way, but omitting them is considered impolite or, when talking to a person of superior status, even rude. Besides ending most sentences, they can also mean *yes*, *OK*, *please*, *thank you*, and *I see*. I don't think ครับ et al. actually cover one third of all spoken words in Thai, but it wouldn't be hard to imagine a language that takes this extra step. If you don't require your most common word to confer a meaning (a formality, a nearly universal response, a common interjection, or some kind of pronounceable punctuation), one third should be plausible. [Answer] While one can imagine a language where a single word is that common, it is hard to imagine the language *staying* that way. People tend to shorten words that used often, very common words may shortened right out of existence. When everybody understands what you mean anyway, there is no need to actually say the word. If you listen to people speak, you may notice that they will very often drop "the". (in some dialects) In a hundred years, people will drop it while writing too. In two hundred years only scholars will understand what "the" means. [Answer] The boundary between words is arbitrary. Officially, linguists define the boundary between words to be "wherever native speakers think there are boundaries" Thus, the easiest answer to this is to define a binary language, with two words. 100% of our computers use a language like this, so it's clearly effective and sustainable. [Answer] Additional to the other answers possibilities are: **Accentuation** This is only valid if you would regard words as the same if they only differ in accentuation: heihohi could mean like 9 different things depending on how the syllables are spoken (a bit like Chinese/Vietnamese). However, in written form you should then find differences. heihòhi héihohi heihohí. - It's very nice today. **Position in sentence** Oi at the beginning of a sentence could mean "to" and at the end "not" and in the middle some form of be. Oi oi or oi oi. - To be or be not. **Number of repeats** No could mean no and "no no" could mean really no. A dog and a a cats make a a a animals? **Some empty phrases that are required for some reason** Xuxu might mean "Listen to me" and must be placed after every other words. Oki might mean "That's clear." The earth oki and the sun oki are very big oki oki. **Some important religious concept** Om says, that the Omnious ways tell us that the highest flow of Om giving the best crop is in spring and Om will provide us with everything, Om will help us, Om, so let's Om. All in all, it all sounds a bit strange to us, the biggest problem is surely to make the language not seem overly redundant which might look too artificial. [Answer] Since it has not been mentioned yet: Phrasal containers. I can't point to a good natural language containing rigid ones, but in computer languages, they're omnipresent. Imagine if `( )`, `{ }`, and `begin / end` of sentence parsing were marked by some word/particle rather than inflections or tone? The stringing of adjectives to their nouns by “-e-” in Persian comes to mind as a sort of analog. I believe (?) Japanese has some similar particles like “o, wa, no” that serve similar grammatical purposes. > > This sentence in English has a few segments that could be delimited in various ways. > > > ↓ > > (sentence {this-one) {in (language English)) has segments {how-many? few) {“that”-subordinating delimited-in {could-be) ways {how-many? various))) > > > Using α/ε and ω arbitrarily, and assuming that ε is an inflected/tonal variant of the “word” α, and that there's an inflected/tonal variant ω´ for closing all open phrases at once: > > α sentence ε this-one ω ε in α language English ω-ω has segments ε how-many? few ω ε that-subordinating delimited-in ε could-be ω ways ε how-many? various ω´ > > > That makes α/ε and ω collectively make up around half of all words. [Answer] The best example and explanation I can think of (right now) is from the TV show [*Rick and Morty*](https://www.youtube.com/watch?v=Q71-NJ_FY88). Which, as you can see in that clip, can lead to confusion for someone new to the language (but presumably no problem for those fluent). Essentially, context is the key. For example, if I said to you "I ***squanched*** my leg badly in soccer last night", you would likely understand that I ***hurt*** my leg last night (especially more obvious if I were present and had a cast/splint/bandage on my leg). Usage as a verb/noun/adverb would also be determined by context of the sentence: * Verb: "I ***squanched*** my leg badly in soccer last night" * Noun: "I hurt my ***squanch*** badly in soccer last night" * Adverb: "I hurt my leg ***squanchly*** in soccer last night" As for it being a third or more of a language... "I ***squanched*** my ***squanch*** ***squanchly*** in soccer last night" may not be so easily understandable, and that's just a third, without physical presence to provide extra context. However, being more verbose could help to clarify it: "I ***squanched*** soccer last night, and ***squanched*** my ***squanch*** ***squanchly*** during the ***squanch***" is more obvious to what I mean ("I ***played*** soccer last night, and ***hurt*** my ***leg*** ***badly*** during the ***match/game***"), particularly if I'm present with a cast/splint/bandage. [Answer] Instead of the delimiter between symbols being silence, instead have the delimiter between phrases another word, not unlike the use of 'over' rather than silence to delimit conversations over radio. [Answer] Depending on the sorority, the word "like" can take up anywhere between 10-40% of all words used. For fraternities, the same can be said for the word "bro". [Answer] **Non-verbal communication** - facial expression, body language/positioning, gestures, etc play a huge part in many cultures, altering the meaning of words and phrases, and sometimes eliminating the need for spoken language at all. Perhaps your humans evolved in extremely difficult/broken terrain or live in widely spaced trees, and most of their communication (outside their own family?) is done outside of shouting range but within visual range. With or without tools such as semaphore flags, Morse code, smoke signals, etc. Poor eyesight or mobility would severely limit your ability to communicate. --- Others have already mentioned **context** (words can have different meanings depending on how and when where they're used) and **intonation** (similar words in [tonal](https://en.wikipedia.org/wiki/Tone_(linguistics)) languages sound identical to the untrained ear). --- Outside of movies (or audio books I supposed), it would be very difficult to world-build with a focus tonality - unless the rest of your story is extremely compelling, very few people are inclined to learn to read [diacritics](https://en.wikipedia.org/wiki/Diacritic) or speak [Klingon](https://en.wikipedia.org/wiki/Klingon_language) (for example) in order to grasp the nuances of your story. Same goes for completely non-verbal communication in writing, though it could be interesting for graphic novels - writing a gripping scene about exactly how a main character was "wiggling his elbows while tilting his head in the 3rd position to show sympathy" would be pretty hard to pull off. Supposedly all ballets tell an unspoken story through dance and music though, so it's not impossible. [Answer] ## Pure/good/virtuous These sorts of words can be applied to practically anything. There may be a superstition (or even magical basis) for these words helping ward off evil and lead to favourable outcomes. It helps if the language makes no distinction between adjectives and adverbs ("pure" and "purely" are the same word). E.g. My pure wife purely brought pure-home purely 4 pure baskets of pure fish! The word can even be repeated a few times when the speaker is particularly concerned about something, or wants to show particular respect for someone/something. Additionally, the word (possibly repeated) could be used as a greeting and farewell. "Good good good good good!" could imply "This event [our meeting] is excellent!" ## With-God For religious reasons, it may be expected to say "with God" (which may be a single word), or something similar, about practically everything. ## Um Usually people who are searching for words mix up their filler words ("you know", "like", "um", "uh", "well") so as not to be too repetitive. But there could conceivably be a culture where conventional wisdom states that there should be one way to say something, and the simplest way should always be used, meaning that people always say "um" when they are searching for words, and they search for words a lot because they are trying to find the simplest way to say things. (Ha!) If the word rolled off the tongue nicely (like "mala") it might be repeated a lot while the person is thinking. ## Emphasis word A word that adds emphasis might be thrown into sentences frequently, sometimes repeated several times. If intonation and stress already serve other purposes in the language, then this usage could be reasonably long-lived. ## Overuse of *not* It is conceivable for sentences to be formed using negatives galore. For instance, "I'm not sick" could be phrased "not-others not-is not-healthy". Why would people do this? It might start out as humour, then turn into tradition. Maybe some revered hero or wise man spoke in this way and generations of people studied his teachings and emulated him. Maybe a bit far-fetched but *somewhat* plausible. [Answer] This may be a bit less plausible than some answers, but how about music? La-la, la-la, la - la-la, la-lah-la-la-la lala la la, la-la, la la-la, la-la-la la-la, la-la, lala-la la -la -la -la lah So, when referencing music (tunes, rather than lyrics), some filler needs to be used, not for inherent meaning but just as a vehicle for the tone, pitch, and rhythm. The fact that it may be, essentially, pronounced differently (la, vs lala, vs la-la, or Lah) shouldn't make it a different word, because it itself doesn't have its own meaning, it is just filler, and the people using it wouldn't think of it as different words. Of course, to be the go-to for music, it (whatever filler it is, lala or dan-dahn dan, nana-na or something) should probably also be a word, perhaps a filler or emphatic or placeholder, since they tend towards short easy sounds anyway. If a culture is pretty musical, and also high-context (where people are supposed to notice and reference, rather than spelling things out), some filler word might end up being a substantial part of their vocabulary - because they are essentially quoting bits of songs at each other (well known ones, for well known meanings, or obscure ones when sure of audience) about like we use quotes or references, anywhere from in-jokes to obvious cultural references. You would need to quote pretty often, to keep the percent at a third or a half of a conversation - but on the other hand, you can stack them up pretty much on top of each other, depending on how long the quoted music is. [Answer] In Vietnamese, the language is mostly confusing, we can see through a sentence down here: > > Con hổ mang bò lên núi > > > This sentence up here have 2 meaning: A tiger brings a cow to a mountain(meaning 1) OR A cobra goes up the mountain(meaning 2). Why so many meaning? Because those words are "same-sounded word" which mean that those words speak the same way, but have different meaning. Another confusing sentence: > > Con ngựa đá con ngựa đá, con ngựa đá không đá con ngựa. > > > So what does it mean? If you are just a new Vietnamese learner, you will assume the word *đá* as the verb *kick* and so this is that sentence in English: > > The horse kicks the horse kicks, the horse kicks doesn't kick the horse > > > Huh?? But *đá* isn't just a verb. It's a noun. Since there's nothing to actually recognize is it a verb or a noun (like the verb *be*) and therefore proving that Vietnamese is very confusing. [Answer] It's pretty easy to do! Let's take English as base language: * add a new word "da" meaning that a given word is a verb * add a second word "na" meaning that a given word is not a verb And let's use "We have never been to Asia driving cars, nor have we visited Africa riding bicycles" as test sentence: "We-na have-da never-na been-da to-na Asia-na driving-da cars-na, nor-na we-na visited-da Africa-na riding-da bicycles-na" Based on this answer <https://english.stackexchange.com/questions/55486/what-are-the-percentages-of-the-parts-of-speech-in-Rnglish> you just need to create a word for #?\*\$ parts of speech and another word meaning "part of speech different from all #?\*\$" keeping in mind that the latter must sum up more than 50%. Edit: Another example could be a language spoken so fast that getting when a word ends and a new one starts could be difficult, so a word with a strange sound not used in any other word could be used as "space": "We-§-have-§-never-§-been-§-to-§-Asia-§-driving-§-cars-§-nor-§-have-§-we-§-visited-§-Africa-§-riding-§-bicycles" [Answer] The first rule, I think, is to make them speak less. So that the overall quantity of words are comparatively lower and, hence the effective 30% can be composed of similar/nearly identical word(s). Or you can just have a totalitarian government, where the ruler/authority needs to be addressed by the speaker every few words- irrespective of the case/ mood of the sentence. If you have seen The Dictator movie, you will get the point. One more question I have is, do you want it to be the same word with different homophonic version, or the same word, with the same pronunciation meaning different thing in different contexts? ]

[Question] [ Say we have a group of space travelers who have been frozen inside a sleeper ship for an enormous amount of time that left when Earth was recognizable. When they thaw out and reach their destination, they land on a planet which has only one super-continent and possesses a desert ecosystem which evolution has rendered almost completely alien, compared to present day flora and fauna. Since the solar system has orbited the galactic core multiple times, the stars are in completely different positions and the amount of time that has passed has noticeably increased the physical size of the Sun. Also, during the time that passed, an extra-solar gas giant passed close by Earth in which the Moon was knocked from orbit to become a planet in an independent orbit, as well as sending Mercury crashing into its parent star. Civilization it turns out, collapsed shortly after the astronauts left for the stars due to severe and abrupt climate change and any artificial traces of humanity has naturally eroded away into nothingness while the surviving species reverted back to something reminiscent of a house-cat sized purgatorius. Disregarding exactly how the ship and crew managed to survive time itself, how would our unfortunate star sailors realize that the planet they are on is not alien at all, but instead they have traveled in one unfathomably huge circle? [Answer] Even with Moon and Mercury out, the rest of Solar system should still be recognizable. Venus, Mars, Jupiter, Saturn and the rest [should still be on their orbits](https://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System#Planetary_migration), though those orbits may shift a little. Also, Andromeda galaxy would not go away, and while its presence has no relation to Solar system, the distance to this galaxy may serve as a somewhat accurate galactic clock. P.S. Also, according to modern science, with Sun getting more luminous, in one billion years Earth would be unsuitable for human habitation. [Answer] Even though evolution surely would have replaced all lifeforms on earth with new ones in 600 million years (assuming there are any left), the lifeforms would still have something in common with their distant ancestors -- if not visibly then at least on the cellular level. Among other things, I find it likely that the cells would still be divisible into prokaryotic and eukaryotic cells, with roughly the same structure; that all cells would store their genetic information as DNA or RNA and have cell walls made of phospholipids, while the eukaryotic cells would get their energy from a form of mitochondria. These are traits which have survived for hundreds of millions of years, and which are very dominant in today's world, making me assume that they would be very hard to replace. I do acknowledge that this question has one significant weakness, and that is that the astronauts simply could assume, that they just have come to an alien planet, where evolution has led the alien cells to use similar survival techniques as earth-cells. The problem is obviously that we -- since we don't know of other lifeforms than those on earth -- do not know if other planets could evolve life with significantly different traits, but I do at least find it hard to believe that the cellular structure we see on earth is the only possible way of constructing life, and therefore I do think that the astronauts, eventually, if they continued to discover such strange cellular similarities between the lifeforms of the planet they had arrived at and their own cells, at least would start suspecting that they might not be on an alien planet. [Answer] Really a comment, but too long: You have some big problems here. 1) The astronauts don't wake up. After six hundred million years of suspended animation. You're looking at .17 mSv/year from the potassium in your body. x 600,000,000 years = about 100,000 Sv of radiation. LD50 is 5 Sv. That sort of dose is a drop-dead-on-the-spot type dose. 2) Pangaea has probably broken up again by then. [Wikipedia](https://en.wikipedia.org/wiki/Timeline_of_the_far_future) 3) CO2 concentrations will be very low. Your ecosystem is descended from grasses and succulents as all the rest are extinct or close to it. 4) It's unlikely there is anything wolf sized alive then. There won't be a lot to eat and smaller stuff gets in more life cycles and thus evolves faster--the big stuff will die out because it can't adapt. 5) Unless something has happened the moon is still there, just farther out. 6) It's too hot. I'm not finding a temperature for 600 million years but extrapolating from a value I did find we get an **average** temperature of 93F (33C). That means most of the planet will be too hot for human survival outside protected environments. [Answer] The astronauts could determine they had landed on Earth because of sampling the isotopic ratios of minerals. This will match the isotopic ratios of the time they left Earth. yes the proportional amount of radioactive decay will have shifted the content of radioactive elements but that should be enough to confirm they were 600 million years in the future (sort of). Also, they will know they are in the solar system because of the presence of the Moon. Even if it is now an independent planet (high unlikely, if considered realistically) many of its surface will be similar to those of the earlier. Plus the isotopic ratios of lunar minerals will clearly indicate they are part of the Moon. Saturn's rings will be long gone by this time. There may be other changes due to human activity on the moons, planet and asteroids. Yet many aspects of the solar system will still be recognizable. For example, Pluto and its moons may be relatively unchanged. The positions of the visible stars will have greatly changed in 600 million years. the nearest star to go supernova is most likely to have blown up by then. This can be a marker for how far in the future they are now. Despite the changes to the local astronomical environment, there will be enough indicators to clearly show the astronauts are on Earth 600 million years later. [Answer] The night sky will still tell you, your planet is orbiting our Sun. Just ignore the stars of the Milky Way. The Milky Way is just one galaxy of many. It is moving, but in 600MY it will have moved about 11 times its width. But it is only 100,000LY across; other galaxies are a million (M100 is), even 1.5 million LY across (Hercules A). They are moving, but Hercules A (or M100) will be so close to their original positions, from Earth's POV, that they can't be anything but those galaxies; no matter how their stars may have moved about in that time. Nothing **else** that big could have appeared that quickly. Given just a few dozen large distant "lighthouse" galaxies in the universe, we can compute our position by their relative positions and angles with each other; the lines between them will form a kind of 3D mesh that is unique to each position in space. Their rate of movements is already known, we can compute how this map will look at any future point in time: In one million year steps would suffice. Using that, they can discover they are 600M years in their future, and using that, determine their location is our Sun, in our orbit within the Milky Way, and that the planet they are (due to its size, mass [measured by strength of surface gravity] and orbit) has to be Earth. [Answer] Fossils. The oldest known fossils of living organisms are at least 3,000,000,000 years old (more than five times older than this 600,000,000 year period in this mental exercise), and have survived all the geologic and physical processes that wear away rocks in that time. About 540,000,000 years ago (slightly less than the 600,000,000 year period in this mental exercise), life suddenly evolved into many complex forms and a great number of species, and these fossils are still around today, such as trilobites. So, it's no great leap to think that in 600,000,000 years, humans awakening and landing back on Earth would find fossils of the creatures they already know that are alive here on Earth today, even though the living things they would see around them in the near barren environment of that future time would appear quite different from organisms today. (But maybe not all that different... crinoids first appeared 530,000,000 years ago and are still around today and have hardly changed in appearance.) [Answer] I think that it is very poor navigation if the ship lets the crew sleep much longer than intended and winds up on their home planet instead of the destination they were supposed to reach. At one percent of the speed of light the ship could have traveled 3 million light years to a nearby galaxy and back in 600,000,000 years. If the mission was to travel for 10,000 years to a star 100 light years from Earth, wake the crew and have them explore, put them back in cold sleep, and return to Earth after another 10,000 years, and the ship instead traveled for 600,000,000 years (30,000 times the planned duration) before returning to Earth, shouldn't the ship have woken the crew and asked their advice or orders about the "minor" change in the mission. The travelers should ask the navigation computer where they are and be told it is Earth in the distant future. The ship would have calculated and kept track of Earth's ever changing position and landed the ship back on Earth after 600,000,000 years. Couldn't the navigation computer have been aiming merely to reach any star and planet in our galaxy, and only stumbled upon Sol and Earth by accident and thus not know where it was? That is theoretically possible, but with hundreds of billions of stars in our galaxy, the odds against it would be "astronomical". It seems to me that they will soon deduce that the universe is 600,000,000 years older. The expansion of the universe will mean that it will be slightly thinner. The galaxies will be spread out more. Deep field images of the farthest visible galaxies will show significantly fewer per square arc second. The nearby galaxies will all be father away, except for the very nearest that are gravity bound to our galaxy and will be measurably closer. Our galaxy is like a gigantic solar system in that every astronomical body orbits around the center of the galaxy. Some orbit it with periods of a few thousand years, some orbit it with periods a million times that long. Most present open star clusters will have been dispersed by the gravity of passing stars and only a few massive present ones will remain among the newer ones in the future. But globular star clusters can hold together for many billions of years. They often orbit the galactic center at distances several times that of the The Sun. The Sun is estimated to take about 225,000,000 to 250,000,000 years to orbit around the galaxy once. In exactly 600,000,000 Earth years the sun should have orbited about 2.4 to 2.66 times. Globular clusters with 400 million year orbits will have orbited 1.5 times and will be in the opposite points of their orbits. Globular clusters with billion year orbits will have orbited 0.6 times. And so on. If external galaxies can be identified well enough to show that the spaceship are in our galaxy, the positions of the globular star clusters in their orbits in the external galaxies should tell how far into the future they are. The angles between where they are, the center of the galaxy, the center of the Andromeda Galaxy, the centers of the Magellanic Clouds, etc, should show them where they are in our galaxy. And they may note that in 600,000,000 years our solar system should have orbited to a similar position in our galaxy. If they take samples of rocks and minerals from the Earth, Moon, Mars, etc. they should deduce that their chemical composition and isotope ratios are consistent with those planets 600,000,000 years in the future when the radioactive isotopes have decayed for 600,000,000 more years. If they dig up fossils on the Earth, they will discover that the geologic layers 600,000,000 years old have fossils identical with recent Earth organisms. If they analyze the DNA of the life forms they will discover it has the same base pairs as on Earth. And if they compare the genetic codes of the future Earth live forms to those of present Earth life forms they will find it is consistent with the number of genetic mutations in 600,000,000 years. [Answer] # It wouldn't be that hard. You wouldn't even have to get off the ship. Note- this answer predicates on the continuing functionality of the ship's central computer, however, given the successful navigation to and landing upon the surface of Earth, the computer seems intact and functioning. # Timing The timing would be the easiest part- radioactivity! There are a surprising number of sources for radioactivity, most of which could be traced for timing. A radioactive engine would be too easy (trace the material, etc, etc), so let's get creative. A common staple for smoke detectors is Americium-243, as it ionizes particles well and without harm to humans (smoke doesn't conduct electricity, so the flow is disrupted, causing the detector to go off). It has a half-life of 432.2 years, so that would be out, but the decay has a product (as every decay does). Neptunium-237 as a half-life of 2140000 years, which would last us a significant amount of time. From there, the Neptunium Series is followed, and at any point the amount of any element along the way could be analyzed to conclude the timing. Current day, many weapons systems are based off of Uranium-238 or Plutonium-239 and their reactions. It would take an entirely separate answer to explain how critical mass works, so let's just focus on the weapons systems. Much of the Uranium-238 would have long decayed into Thorium-234, which would then follow the Actinide Decay Series. Plutonium-239 would also follow the Actinide Decay Series, just starting at a different part. # Placement Okay, the timing has been identified. What now? The stars have moved about considerably, but there is still hope. The ship is close to Earth, as it lands there, which means it traveled near to it, or has at least returned to it. If the civilization is in any way gifted with foresight, they would have plotted all coordinates off of galactic center. The ship has been flying this whole time, plotting points and taking note of it's mission. Being 600000000 years in the future, one can assume the reasonably intelligent astronauts would know the galaxy rotates, but also know that, and I cannot stress this enough, *they rotate with it*! Even if the mission was (most likely) extrasolar, the rotation of the galaxy is predictable enough that one could identify the earth's likely position, and then compare it with one's own likely position. All in all, no part is that hard. [Answer] **Space Junk** Nope, not the run of the mill debris around the planet, after 600 Million years, the minimal atmosphere will have degraded the orbit of LEO satilites enough to cause it to return and burn up in the atmosphere. Even out past geostationary orbit, the tidal drag will have deorbited any satilites after this amount of time. Instead, you look for the Junk in Solar orbit. There are quite a few peices out there, assuming your future space ship has the required technology, spotting an Apollo booster stage in solar orbit (or possibly a satillite left in solar orbit, we've done a few of those too) would be a good signpost that you're in our solar system. [Answer] Depending on exactly when Earth's civilization burns out, there may be recognizable remnants of Human technology. Nothing large, I'd guess, but very small items may survive, such as nanobots, and crystalline storage devices. Also twinkies, undoubtedly. Erosion and oxidation would make it difficult to find any obvious traces on the planet's surface, but potentially space debris, a moon base, or underwater cities could have surviving remnants. If there is any biological life, it night still have genetic traces of bio-engineering, such as a copyright notice written into GM corn DNA. Our particular configuration of planets, their sizes and compositions, and ringed / unringed natures may persist and be observable by the travelers. Even if the Earth looked unrecognizable, the neighborhood may be familiar. Jupiter for instance protects the Earth against a large volume of incoming space debris. In many other solar systems, the Jupiter-sized planets seem to be on the inner rings, and very hot. The moon may also have key features that are still identifiable, and is in synchronous rotation with the Earth, so we essentially only ever see one side over reasonably observable timespans. The astronauts might notice this and it may be anomalous. There may also be some geological aspects of Earth that are fairly unique. For instance, Earth is able to maintain its atmosphere and water against solar winds because [the magnetic field is especially strong](https://www.reddit.com/r/space/comments/2robyp/other_than_liquid_water_and_life_what_makes_earth/). That field strength is thought to be generated by a combination of the molten core, the speed at which the Earth spins, and possibly our core's iron-nickel composition. The right combination of factors to generate the right field level, particularly for liquid water (if it still exists) appears to be fairly unique. On top of which, the molten core thought to be kept molten in part due to the moon's gravitational pull. Earth appears to be the only known planet which has plate tectonics, which is also what released Earth's water to the surface, previously trapped within. Interestingly, the oceans also enable the plate tectonics. These types of dynamics and the balancing act between the geological effects may be rare. Also have a look at some cryptohistory, in particular- * The Coso Artifact, a human-made object discovered inside of a fully formed geode. Geodes are estimated to take about 500,000 years to form. * Fossils such as the human footprint found in a shale deposit in Delta, Utah. Estimated age 300 mil - 600 mil years old. You can find quite a few more [interesting examples here](https://www.thoughtco.com/the-most-puzzling-ancient-artifacts-4086398). [Answer] Following on from @some-dude's answer, crocodiles haven't changed a lot in the 65 million years from when dinosaurs roamed the Earth. Someone coming to Earth in the far future may be able to recognise descendent creatures from what exist today. > > Of all the reptiles alive today, crocodiles and alligators may be the least changed from their prehistoric forebears of the late Cretaceous period, over 65 million years ago--although the even earlier crocodiles of the Triassic and Jurassic periods sported some distinctly un-crocodile-like features, such as bipedal postures and vegetarian diets. > <https://www.thoughtco.com/crocodiles-the-ancient-cousins-of-dinosaurs-1093747> > > > Cockroaches may also have had a similar form to those that exist now and could have been around for an even longer period of time in our pre-history than crocodiles. > > The Carboniferous, around 300 million years ago, is sometimes called the Age of Cockroaches because insects broadly resembling modern roaches flourished during that era. However, the first really modern roachy remains appear later, in the early to mid-Mesozoic, perhaps 200-180 million years ago. Modern cockroaches have changed little from those ancestors. <http://guides.library.harvard.edu/c.php?g=310507&p=2072128> > > > So perhaps our sleeping astronauts may be able to use their knowledge of modern creatures and extrapolate from there. But, the one thing I'm pondering - what would make the astronauts want to think they're on Earth and not some other destination? Why would they suddenly decide they want to investigate the creatures they are seeing and want to determine if they're still on Earth? If they were expecting to be arriving at some other destination they may believe life has a similar, common form throughout the universe (especially if they had never encountered alien life elsewhere before). They may not even *think* to ask the question, "Are we back on Earth?" [Answer] Very, very carefully. If you're a space traveler, you'd had to've gotten there somewhere. Right? They are space travelers, unless they're just roaming randomly looking for earth they have to have some measurement or calculation of their historic travel. So then you can just run over your path, calculate the orbit of everything, and boom. Hopefully at least. They have to have at least some general idea of how far they've traveled, for how long, and in which direction from their origin The most efficient way to conclude, would be to check your previous measurements and estimations. Assuming they're proven and correct, you can ascertain the truth that you must in fact, be on earth. Otherwise, one would never know. The claims of using the stars are wildly inaccurate. Most stars may have burnt out, and/or completely changed orbit; in comparison to the fact of probability that there must be other planets also that share similar constellations. This would inevitably become a wild guess within the realms of what's possible. There would be almost no similarity outside of the certainty that, you must be very good at record keeping. [Answer] When they 'Thaw Out and reach **their destination**' the Captain will know exactly where he is. At the destination he programmed the ship to go to. (And will send his compliments to the refrigerator company). [Answer] Have the astronauts catch a .[Coelacanth](https://en.wikipedia.org/wiki/Coelacanth). They have existed in basically their current form for 400 million years or so. If they survive the death of humanity they could potentially last another 600 million years. [Answer] Given a (reasonable) bit of luck, **The solar system will still be recognisable**. There will be five naked-eye visible planets whose orbital periods will be remarkably similar to ours. Oner heck of a co-incidence, if it's somewhere else! Use of a telescope will reveal Uranus and Neptune, and the sizes of the five planets, and their major moons, once again pretty similar to our Solar system. Mars will almost certainly still be red; Olympus Mons and other major features largely unchanged. Earth's day will be longer, but its year will be only slightly so. The Moon will be considerably further away and "smaller", but like Mars it will look much the same. (There's no reasonable natural way for it to vanish, that doesn't wipe out life on Earth at the same time it does). Why "with a reasonable bit of luck"? Because all orbital mechanics with more than two bodies is mathematically chaotic. There is no guarantee that orbits within the Solar system won't change dramatically in the far future, possibly with the result of one or more planets smaller than Jupiter being expelled into interstellar space. Best observational data and computer modelling says the current arrangement is stable for about 200M years, so no cause for panic. Beyond that, we can say nothing, because the model is "sensitive to initial conditions" inside the error bounds of the observations. **Fossils** may be another give-away, but after a billion years, plate tectonics will have subducted most of the sedimentary rock formed in the present day. More likely indicators will be seen from **biology** and **biochemistry**. The genetic code of life will still use the same codons for the same bases. The major enzymes shared by all life will still be the same, modulo accumulated mutations which do not damage the functions (because any damage to the fundamental mechanisms of life, will result in death at a very early stage). Biology will supply similar clues at a higher level. For example, mammalian (and bird, reptile) eyes have a "design defect". The blind spot, where the optic nerve connects to the retina. The same compound eye design evolved independantly in molluscs (octopuses and squids), minus this defect. There will probably still be recognisable mammals, birds, reptiles and squid. There are many similar "design defects" which once evolution has taken a particular track, are "designed in" and cannot evolve out except by extiction of a whole branch of the tree of life and re-evolution of some similar organism from a different branch. That has not happened often over the last 600 Myears. I've ignored the problems others have pointed out. A billion years it too far in the future: the sun will have become so hot that unless chaotic orbital mechanics provides a miracle, the Earth will by then be dead. Half a billion years, and the Earth will probably be hotter, dryer, but still habitable. Suspended animation for that time is surely impossible. It might be more plausible to employ handwavium. Maybe a prototype warp drive malfunctions, and instead of crossing light-years in an instant, it merely provides a one-way jump to the future. (ISTR Larry Niven(?) wrote something similar as a short story ... it was a passenger spaceship with a faulty drive). [Answer] The night sky will be pretty similar, with sufficient vision and record it should be rendered unique, if they know the order of magnitude of how long they were asleep and how fast they were going. It would be unique and relatively predictable, though not the same. [Answer] Depending on how many explorers there are to start with, and what technology level they have brought with them that they can use to bootstrap their society, it might take a very long time. In the worst case, there is not enough population to maintain the same education level through generations, and unless the ship can maintain itself indefinitely, there is a risk that all knowledge of the old earth will be lost. Assuming away those issues, some clues will be in the earth and some in the heavens, and it all assumes the explorers even bother to care about this question. * While the moon no longer orbits the earth, but is a "dwarf planet" now, once it can be observed through telescopes, it may be possible to prove that it is the moon. At the very least, its size and surface composition will be pretty much the same. Though it will be more subject to surface impacts on both its faces now. * Once some good space telescopes can be set up, extrapolating the proper motion of observable stars backwards should produce a past snapshot that agrees with today's map of the skies. * If the ship included several radioactive samples on board with various half lives, the approximate length of the voyage can be calculated if one of those is a Uranium 238 sample. * At some point it is plausible that new ancient stone fossils will be discovered. Either they would agree with the historical archives of the ship (dinosaurs etc) or they would match known "present day" life forms (humans, dogs, horses, pine cones, etc) and make a convincing case that the planet is earth. * It is not unthinkable to locate a stable stone monument of human construction. A partial pyramid is probably most likely to survive that amount of time, through earthquakes etc, particularly if completely covered by earth. Anything left exposed to wind and rain has much less chance. If buried and not near water, deep stone engravings could survive. * Crocodiles, cockroaches, [lancelets](https://en.wikipedia.org/wiki/Lancelet#Model_organism) and other creatures are found in forms similar to present day forms in the fossil record. So there is a good chance at least one of them will be found, or something much like them, this far in the future. * The gross chemical composition of the atmosphere, soil, deep rocks, and ocean will match any records on the ship of the earth. * The approximate mass of the oceans, overall mass of the earth, average radius of the earth, distance from the sun, approximate length of the year, and other parameters should all match ship records of earth. (I interpret the question to stipulate that earth's year is not changed.) However, without the moon, parameters of earth's rotation (including eccentricity of earth's shape and of its orbit) may not. Whatever trauma was sufficient to remove the moon from earth's orbit could have significantly altered the axis of rotation and other parameters of rotation that are stable and predictable today. All of these factors taken together will make a good case that the planet they have found is in fact the earth. Assuming they even care. [Answer] The stars. As soon as he gets a telescope and starts looking at the galaxies further away, she/he should realize that she's/he's either on earth or on a planet much closer to earth than he/she intended. At this point the astronaut in question should start looking for a way to prove what planet she's/he's on. The make up of the ground shouldn't change that much and the earth should look something like what it's expected to look like 600 million years in the future. There should also be human artifacts here. The real question is shouldn't the sun have swallowed the earth by that time? [Answer] > > ...how would our unfortunate star sailors realize that the planet they are on is not alien at all, but instead they have traveled in one unfathomably huge circle? > > > They can never be sure about that. After all what are the chances that there is another solar system with some planets and a brighter sun and no artificial traces of a past civilization, totally different star patterns and cat-like species (as you describe it). It could be that in one of the hundreds of millions other stars in one of the million other galaxies this will be the case in 600 million years. Getting the time right might not be a problem, we measure the [age of the universe](https://en.wikipedia.org/wiki/Age_of_the_universe) already now (with some error) as 13.8 billion years, so maybe it could then be measured again as 14.4 billion years. But being certain about the location, that would require some statistical estimation of how unique our solar system is currently, how quickly that changes and then how significant the reasoning is that if you see certain species and fossils that it can only have been earth. It all depends on how unique we are and we don't know that. The best idea would probably to colonize the new planet and then spread out to find something that resembles the original earth more. If you don't find anything, you can still think you are on the original earth, but you may not be sure about it. In principle if we map enough stars and galaxies and have precise enough informations about their evolutions for the next 600 billion years we might have enough evidence to conclude we are still on earth, but I doubt that. ]

[Question] [ In a world I am building, the day lasts longer than the year, 9 times longer in fact. The native people of this world have been forced to migrate around the world, both avoiding the scorching desert of noon and the freezing winter of night. This world is otherwise rather unremarkable on the surface. Outside of the planet is a ring as well as many small moons, so many that the tides are rather small and unpredictable, but as I was designing their culture I realized something, without seeing the stars, would the have astronomy? How would a species that lives in eternal day have any knowledge of the stars? [Answer] ## The *poles* provide the ability to stay on either side safely. Since the planet has a relatively small axial tilt (13 degrees), the North and South poles of this planet shouldn't be incredibly cold relative to the rest of the world. They would be inhabited, just like the rest of the "belt" that spans the planet. Observers at the either pole could (somewhat) safely foray into the night area and back without being stranded in either condition (night or day), having the sunrise/sunset zone nearby. This could mean safe stargazing throughout an **entire lifetime**, and develop astronomy. --- ### Compared to other ideas * This phenomena allows astronomy to develop at a constant rate, as opposed to allowing a few observations every time there is an eclipse (as other answers suggest). * This also accounts for the danger posed by 4.5 years of constant sunlight or darkness by providing a means to switch to the other side. Comparatively, answers that suggest "people want to explore" do not account for the resulting deaths of those explorers when they cook or freeze, subsequently wasting all that they learned. * Some answers suggest that the sunrise / sunset zone has enough clarity to see stars and planets, but all spectra recorded will be tainted with sunlight; you need "true night" to get accurate results and determine more about the stars. * While traveling from base to base, as some answers suggest, may seem effective in practice, locating the same bases when given the entire hemisphere may be challenging - and bases will likely be damaged severely by frost or heat. [Answer] # People are curious Humans, at least, are very curious. Shamans on spirit journeys, young men on adventures, and outcast groups in exile might all end up traveling into the night zone for one reason or another. And if they had not seen stars before, they would be amazed, and behold them with wonder. Once word got out of these stars, many of the religious or scientifically minded would want to go check them out. [Answer] If they're avoiding both the heat of the day and the cold of the night then there are dawn and dusk people. Most likely you have four main groups, two who move constantly and two who move and settle for long periods. The dawn tribe will move until they start seeing stars, then it's time to settle until the heat of the day catches up with them. The evening tribe will move when the first stars of the evening start showing as the signal that the temperature is going to drop. Both these groups will overhaul the constantly slow moving tribes in their sectors when they move and those who move further ahead at dawn or stay later in the evening will tell stories of the heavens lighting up with stars at the extreme of the survivable temperatures. [Answer] ### Total Eclipse I know this isn't directly an answer to your question, but the novelette *Nightfall* by Isaac Asimov deals with a civilization living on a planet in a system with six suns which keep the whole planet continuously illuminated. The people have no actual awareness of any stars beyond their local solar system, as they cannot see them and they are too distant to detect their gravitational influence. Every 2050 years, another planet in the system coincides with the positions of the six suns and the civilization's world such that, for one brief interval of a few hours, for one side of the world 5 of the suns are "set" and the sixth is eclipsed by the other planet. For those few hours, a world that has always known daylight is plunged into darkness. The story goes on to describe the catastrophic effect that one brief night has on the civilization—and indeed has had on every civilization that world has brought forth in its past as well. It's a good read. But the mechanism of a global nightfall caused by an eclipse would provide a means for the people in your world to learn that other stars exist. (And the story may give you some ideas about how that people might react in the face of that discovery.) Link to complete short story: <https://www.uni.edu/morgans/astro/course/nightfall.pdf> Was later made into a novel of the same name. [Answer] ## Visual Discovery in Dark Areas If your scenario allows for people to venture into dark areas where stars are visible to the naked eye, then certainly that will be the easiest way for people to discover stars. ## Non-Visible Light Astronomy If your scenario requires people to stay in areas where stars are not visible to the naked eye, then techniques other than [visible-light astronomy](https://en.wikipedia.org/wiki/Visible-light_astronomy) will need to be used. I'm not sure if all wavelengths in the electromagnetic spectrum have star detecting applications, but many do: [](https://i.stack.imgur.com/0vvMP.gif) ([Source](http://homepages.uc.edu/~hansonmm/ASTRO/LECTURENOTES/W02/Lec1/Page4.html)) Gravitational fields are also means of detecting stars. ## Problems of Developing Technology in Nomadic Cultures Depending on how much time they are required to keep moving to avoid the noons and nights, they might not be able to develop enough technology to reach modern Earth's levels of technology. So many factors of modern technology have evolved in stationary workshops, where large, heavy, non-mobile things like a blacksmith's forge or a steel foundary's massive smelting apparatus can be built, maintained and operated. Metalurgy and other technological fundamentals might be difficult to develop in a very actively nomadic culture. For example, if the days last for 9 years, but the planet is millions of miles wide, they may be required to move extremely rapidly all the time to stay safe from the noons and nights. If the planet is only the size of our moon, though, they could stay in one place for many earth years on end before having to move to a safer location, giving them time to build shops in which to develop non-mobile technologies (like [Very Large Array telescopes.](http://www.vla.nrao.edu/)) If they do have enough time to build shops, but later have to move on, if they aim to, they can eventually come back to their shops when they have gone all the way around their planet. This would allow them to use stationary technology, just at a different pace and style from the way it developed on Earth. So, the size of their planet will play a huge role in shaping their development of non-visible light astronomy technology. [Answer] In addition to the three good answers so far received, the people of your planet would almost certainly be able to see certain astronomical objects by daylight. On Earth [even in daytime we can regularly see with the naked eye](http://earthsky.org/space/10-surprising-things-to-see-in-the-daytime-sky) the moon, obviously, plus several planets, some [meteors](https://en.wikipedia.org/wiki/Chelyabinsk_meteor) and [comets](http://www.space.com/17918-9-most-brilliant-great-comets.html), and supernovae when they occur. It is true that one cannot normally see stars in daylight from Earth except during a solar eclipse. The moons of your world are small, so a situation like an Earthly [solar eclipse](http://www.mreclipse.com/Special/SEprimer.html), when the shadow of a moon apparently blacks out the sun entirely, will presumably never occur. Nonetheless you might get partial darkening when a moon passed between your planet and the sun, enough to see a particularly bright star. Your world might simply have brighter and/or nearer stars in its sky so that keen-eyed people can spot them when conditions are good. In any case, given that your planet's people will be able to see *some* astronomical objects there is no reason why the science of astronomy should not get started. Telescopes have many other uses than astronomy so would most likely be invented anyway. The brave and curious will make special expeditions to the night side of the planet as suggested in previous answers. In fact astronomy is not the only reason why they might want to visit the night side - doing so could bring them advantage in war, if, for instance, they wanted to launch a surprise attack from an unexpected direction. Trade expeditions might wish to take the shortest route possible even if it did mean wrapping up warm. People might simply wish to check up on their property, to which they intend to return the next day. Criminals and refugees might flee their pursuers to the twilight zone where survival is less difficult than in areas of full night. These travellers through the night and twilight zones will be intrigued to see that unlike the familiar celestial objects these other lights appear to hold their places in the sky. There might be religious pilgrimages to see this wonder. [Answer] **Build a telescope.** A decent telescope can see stars even during the day. For a people dependent on crossing more or less unfamiliar ground all the time being able to see far ahead would be of tremendous value so telescopes would be built and refined if they have the technology to make them at all. [Answer] This is not a truly nomadic culture as they are able to follow the same route over and over. Assuming adequate cooperation between the sunrise population and the sunset population they can become not quite so nomadic. In their spare time they can build structures of use a bit at a time. They will have to move on before it's done (there's no point in such construction unless it's going to be good for centuries) but in time they will come back to it. Once they have weather-protected storage they can build spare tools and leave them behind--this reduces the amount of material they must lug and thus frees up time. More tools, an easier life. Eventually you will have a society where instead of eternally trudging around the planet they move from base to base, traveling very light between the bases and with a very good road connecting these bases. Now we are able to start playing with science. In time they will develop photography--and just because people can't survive the extremes doesn't mean a camera can't. Progress will be exceedingly slow but it will happen. [Answer] It seems reasonable that the near edge of the night zone won't be too hostile for several days and it is also fairly likely that people might end up there because of delays or accidents. Equally as mentioned in another answer humans have a very long history of venturing into hostile environments. After all there is quite a bit of tourism to the arctic to see the northern lights so it's not a big stretch to imagine that people might linger in the night zone for a while just to see the stars. Once you get any sort of scientific culture established it is entirely plausible that scientist might set up bases to venture into the 'deep night', for comparison just consider the expeditions of people like Shackleton, Scott, Amundson ect to the poles all of which were extremely arduous and dangerous. Indeed in this case you don't even have to go anywhere just wait for the night to catch up so building a well stocked base isn't that unfeasible. As well as curiosity there could be economic motivations, perhaps there are animals which live in the night zone which are sought out by hunters for fur, meat or fat, indeed in this world ice could well be a valuable commodity, as indeed it was before the advent of refrigeration. [Answer] **A low-density atmosphere and a solar eclipse** The sky brightness may be strongly reduced with an atmosphere of low density and/or fewer molecules and dust that disperse light. For instance, removing a bunch of nitrogen and ozone could strongly reduce the sky brightness. A solar eclipse could further reduce it to levels where stars become visible. [Answer] Why not? Bear in mind that sometimes we can see our moon during the day. If the celestial objects are big enough, close enough and reflective enough, at the right angle they can be seen even in broad daylight. It's just a matter of size and brightness. So these people probably would've seen some of these objects, or even part of the ring. Their curiosity for the sky would take flight from there. [Answer] Brave and foolhardy early explorers, doomed though they were, may have managed to communicate images of, and/or comments on, what they saw in the Shadow Zone before they froze. Perhaps they managed to send images, or even stream movies, via wireless communication technology. Perhaps they left material behind on some sort of storage media. Even hand drawings and writings would be enough to establish that there's Something Up There. I'm assuming each sub-culture or tribe will have established markers around the planet, its own Road or Path or Belt to help them re-visit the same useful places on every Go-Round. So it's not inconceivable that such artifacts would be picked up again. Subsequent to that initial discovery, how it plays out will depend on the level of technology. To me the idea that this society has access to advanced technology is only a *slightly* bigger stretch than the idea that they've survived at all (due to factors that others have mentioned here). Perhaps they're relics of long-ago stranded space-farers? Whatever the history, if they have some reasonably advanced technology, then this might include the wherewithal to set up unmanned observation stations in the Death Zones. Or perhaps insulated, heat-shielded, climate-controlled bubbles that would allow people to actually live there, much like our own Antarctic researchers or conceivable near-future colonists of the moon or Mars. Even at a lower tech level, localized quirks of geology might make survival possible: a deep enough hole in the ground might insulate you from the big scorch, and various geothermal features might provide enough heat to help you survive the big freeze (even, in some places, close enough to the surface to allow for star-gazing). [Answer] Do these people have basic electrical technology? If so, they could build a radio telescope. Radio telescopes work just fine during the day because radio waves aren't diffused by the atmosphere as much as visible light is. You could see the stars with a radio telescope the same way you can see the stars when you're in outer space. (Speaking of which, they could see the stars for themselves if they built a spaceship.) They may also be able to see the stars if their local astronomical neighborhood was more crowded than ours. Multiply the brightness of our brightest star by ten times and it'll be visible during the day. This could have happened if the stars in our neighborhood were a little closer or a little brighter. The same goes for planets. Comets are already sometimes visible during the day, though this is a bit off-topic. [Answer] If you go down a well, even in full day light you can see the stars... that's how one of the early Greeks realised the stars were there in the day, hidden behind the bright sunlight. So, if your nomads ever dig a well... ]

[Question] [ Imagine that due to an excess amount of handwavium, my world has humans ranging from only a couple of inches, to around 20 feet. Society has evolved to include people of all sizes into the workforce and cities (a la Monster's Inc or Zootopia) but after the industrial revolution hit, a problem arose. How do I, the leader of this world, keep wages fair? Goods cost money to produce on an equivalent value to our system, therefore small items for small people cost small prices and inversely the same applies to large people. Paying everyone equally for the same work creates the problem that giant people will fall into poverty and little people will gain massive wealth. All despite doing the same work for the same hours. If I pay people differently however, they will receive less/more money in total for the same effort. Even having jobs for certain sizes results in a sort of economic segregation, which is an obvious civil rights nightmare. Ignoring the impossibility of such creatures existing, how can I assure everyone is paid fairly and equally when people vary in size? [Answer] **You don't need to 'do' anything - economics takes care of it** Much like it does in the real world. There are two different economic issues: Value of work (money in), and cost of goods (money out). On the latter, sure, it might cost significantly more materials to feed/clothe a larger person, but making smaller goods (and providing smaller services) is significantly more difficult. Essentially, anyone can sew buttons onto a shirt for the largest individual, but only the smallest can do the same for the smallest. This means the increased material cost would be offset against the need for less available skilled labour. The smaller the goods, the more difficult. That's why microprocessors are not ten-a-penny, and if you're dealing with a ring or lace dress for a two inch individual, is that really going to be less expensive? Plus think about services, like going to the barbers, not to mention additional costs you would need: e.g. cat protection. Further the job market would balance according to skillset. E.g. the police, Constables would likely be required to interact with their own populations, but in the larger context a large policeman could catch or spot a fleeing suspect, a small one could spy or examine details, or take something like woodwork: if you were building, say, a chair: a large person transports the goods, saws the wood, the average assembles it, the small engraves the details. Each valuable and necessary, in their own way. I do wonder how you would stop larger individuals abusing their physical advantage though. [Answer] Why would you want wages to be fair? And what is "fair" anyway? You don't need a fair system. You need a system that is temporarily stable and which many people believe is the right way of doing things. In today's world, there are people who are millionaires by the time they are 8 years old, and others who never ever earn a million dollars while working hard their entire life. Yet many people think wages today are fair. True fairness does not exist, it's just an illusion. So **create an illusion**. Find excuses to justify why the CEO, sorry, the leprechaun deserves to earn 100 times more than the hard working giant, or vice versa. To keep it realistic, figure out which subrace is currently in power in your world - these will earn more money than the others. [Answer] ## Keep prices equal for size-dependent goods and services Whichever way you try to balance wages, there is still the problem that some goods and services will be size-dependent (food/clothes/transport) and others won't (financial services, mental health, some entertainment). If larger people get higher wages, they'll enjoy a much better *relative* price for the size-independent services. So instead, write into law that any services offered must accommodate all sizes and offer equal pricing. Underwrite this with tax credits based on the actual production costs or a percentage sold for each size. i.e. a clothing company that serves 80% huge customers will get much more back than one that markets to the tiny population and sells 90% of units there. ## ... or go Communist! As an alternative, adopt communism. With all means of productions owned by local communities, they can divide their profits among the members as needed. [Answer] You pay people according to the work they do relative to the difficulty of finding people to do that work. Anyone can do basic admin, it doesn't pay well, smaller people will do disproportionately better out of it. There will by physical tasks requiring greater strength that might require a larger person, if you can't find one then you'll have to offer more money. There will also be delicate or dexterous tasks requiring a smaller person. Companies without special requirements may well be unwilling to adapt to the smallest or largest when they can cater most cheaply to the mid-sizes, so at the end of the day, expect the people on extremes end of the size scale to be in poverty. Is that fair? Same work, same pay is fair. Declining to adapt your facilities for people more than a standard deviation from the mean? That's a legal matter for your society. Even then your big people are going to be poorer just because of the astronomically different scale of costs they have. They'll probably end up having a fundamentally different society from the small people, a lot more communal housing and catering. A culture based on cost reductions across the board. --- All the government can do is enforce equal pay for equal work. To do anything else at that point in the system risks amplifying any already existent discrimination by making one group significantly more expensive to employ than another. Whether they should choose to subsidise income by other channels is an entirely different question. [Answer] The simplest answer I can see is that your world would use Piece Rate as the standard instead of an hourly wage or salary as is more common in our world these days. If you get paid by the amount of work done (rather than the hours worked or a simple flat rate) then a small person who can only make a few items a day (or whatever equivalent work they are doing) gets paid far less than a big person who can make a lot more items. Of course this won't always hold true and there will be jobs which small people excel at and can make many times more objects than big people, but this will just help lead to a natural stratification of the job market. Big people won't want to do jobs they are bad at and get paid poorly for and small people will seek out these jobs as a preference. This system is often unfair and leads to people being underpaid and has largely fallen out of use (in First World countries anyway) but I think with the vast disparity in sizes and the differing needs for income it may work better in your world. The alternate is some kind of caste system where jobs are rigidly assigned based on size and capability and wages are based on this system so everyone gets a fair amount. As a side note Terry Pratchett makes note of this in the Watch series of Discworld books where a number of Gnome / Nac Mac Feegle policemen are often mentioned to need far less money because they drink thimbles of beer rather than pints and a loaf of bread can last them weeks. [Answer] In theory services will be performed by those who can charge the least for them. Tasks that require giants will be performed by giants who charge a liveable giant wage for them while tasks that requires gnomes will be manned (gnomed) by gnomes who will be paid what a gnome requires to live. A gnome can't perform a giant's task and vice versa (a giant can't even survive on a gnome salary thugh so that's a moot point). Tasks that require ordinary sized humans will naturally be performed by ordinary sized humans. Basically you're getting a caste based work market. And as long as everyone is fine with their lot and as long as there is no inside manipulation from the market players it might even work. Of course... without religious strictures surrounding the caste system you'll probably end up with employers trying to find ways to sell off a job to gnomes as they'll work the cheapest. So the gnome job market will likely be the most diverse. The giants get the short end of the stick since they're the most expensive to maintain and their job marked will hold the least amount of diversity. However, you might want to note that keeping giants happy is a societal survival trait. Your society will probably want to find ways of keeping all giants gainfully employed even if it's costly because when a giant with a lot of spare time on his or her hands have an axe to grind it's usually a huge frickin' axe. (The real world comparison to look into would be failed states with decommissioned armies that have not been properly disarmed.) The obvious way to keep the giants in work would be to finance giant work projects by issuing taxes and levies on the other castes, which has the double benefit of also going towards closing the wage gap. Of course, employers don't really like levies and taxes so there will be controversy surrounding them, at least until the first giant uprising. **The other solution:** You may want to think about completely separate economies. Giants are paid and purchases things in giant money. Gomes use gnome currency. Never shall the two meet. [Answer] You can't be building a world like this, without intending to draw parallels against our own world. And our own world is not fair. If you are aiming for fairness, you are worldbuilding a world of tedium and boringness. In the real world, whatever system you find to allocate fairness will be found unfair by some. * People should be paid proportionally to how scarce their skills are! * People should be paid the same per year! * People should be paid the same per hour! * People should be paid the same per gram of bodymass! * People should be paid the same per dollar earned for the company! * People should be paid the same per year they've worked for the employer! * People should be paid the same per... what's fair? Fair, as others have said, is obviously an illusion, and in reality people usually try to be fair, so will find some mix of the above, and more, to try to ensure their staff are looked after. And in reality there will always be people who get the short end of whatever measuring-stick is applied, and will say it's not fair. Building a world where this issue does NOT arise, is building a bland, beige world. Instead, I'd argue to build a world where these issues are accepted as part of the world's fabric: hardships to be borne, occasionally argued about or overthrown when it chafes too hard, like the caste and class systems that we see on Earth today. Strikes and industrial action are a good way to explain the non-availability of resources that might otherwise give your characters an easy solution. Oh, no, the car broke down. Why not just call a taxi? Well, there's public transport strike demanding more sections of secure tunneling for the smaller drivers, after that accident last week... But it doesn't have to be plot-relevant, it's also just a good way to give the story color, whether it's as a casual reference to how the tiny guy gets to boss around a whole business empire of giants, or how the wealthy giant gets to be constantly groomed by a cloud of little people, or whatever. I wouldn't make wealth be absolutely linked to size, any more than it is to race or gender today. But I'd pick a size and make them the ones with the privilege, whether it's because they can do more skilled work, or are bigger and stronger, or whatever. You can also play with people's internal stereotypes. You can set up the giants to have everyone assume they are ignorant, but then find an educated one who explains that sure, they move slow, and talk slow, but not because they think slow. Just because momentum, and caution not to hurt those smaller than them. As for the rest, it's caste-related; nobody writes textbooks large enough for the giants, the ivory towers of educational institutions are built to a scale that excludes them, etc etc. Or vice versa: the little ones are ignorant, not because they have tiny brains and lives too short to learn anything, but because they can't lift the textbooks. Entrenchedly bigoted stereotypes between the sizes allows both for lively humor, but also for deep commentary. Embrace harsh social realities, but only enough to chafe, not to cut. [Answer] So you have a XIX century economy. Small kids sweep chimneys and work in tight mines. Adults work at steel mills and other places where strength is a must. To that you can add company stores (and 16 tons). Also your problem is wrongly created as you assume that large people can do the same work as small people can. Make a test, imagine the 20 feet person try to pass thread through the needle's eye. They can do that if they have a large needle and large thread. But they can't saw intricate things with that. They can do bags, sails and so on. [Answer] Size is not the only defining factor for your working-abilities. Not all jobs are the same and size/strength is only one determining factor. In a diverse enough society you may find niches for every species. A large, strong species is better suited for work fields requiring raw strength, like heaving heavy crates or producing large scale iron/steel products depending on your level of industrialisation. A small more dextrous species might be perfectly suited for squeezing into small rooms between machinery and repair it nimbly. Or they might get hired for work with very delicate machinery which requires anything but brute force and strength. [Answer] # Make smaller people less intelligent That way with smaller body you will have smaller strength and smaller intelligence. This means that with smaller cost of living you will also have less-paying jobs, and you can keep the same price for square meter of cloth or pound of bread - and at the same time you can keep same pay for equal job. Of course there will be some specializations etc, just as there are in real life, but overall it will be possible to balance this system to have average life rate independent on size. [Answer] If big people cannot buy things, then you will not get rich selling things to big people and then you are leaving behind an opportunity to make a profit. I think this will be a mitigating factor at least, that will make prices for big people go down. Another mitigating factor is that big things are often much easier to make than small things. So production costs for small people might be higher even if the material used is less. Of course this is up till a certain point, but I think it will hold for many consumer goods. But big people might be more partial to bungalows and small people to relative high buildings. I think there are also a number of reasons why there will probably be less giant people than smaller people, but that will depend on your handwavery. Growth into adulthood will be much slower, the number of children will probably be lower and at those sizes there are a number of biological reasons why they might not live to get very old (stress on bones, heart, etc). On the one hand this makes the market smaller for big stuff, but it will also make the number of big people available for your workforce smaller. I think we can agree a giant might be extremely handy for many situations, so this should improve wages. In the end I think food might be the biggest problem. Perhaps you can provide a sort of communal dining facility where every citizen can get a basic meal that will get him or her through the day, regardless of size. Granted, small people might be able to afford more luxury foods from their disposable income, but giant people can at least choose if they want to use their precious disposable income. [Answer] If you have a sufficiently authoritarian system, the solution is simple: Make it illegal for smaller people to buy or use goods intended for large people. This essentially sets up a parallel economy for each size category. This is actually going on in the background in Zootopia - one of the "crimes" that Nick commits early on is arbitrage of these price differences: he buys popsicles meant for elephants (and is unable to buy them openly) and melts them down and refreezes them [in the climate controlled arctic district] in smaller shapes for hamsters (along with selling the sticks as construction wood). You can disguise this in various ways - the supposed reason he can't do this is, IIRC, because he doesn't have a business license and safety inspections, but that doesn't explain the absence of legitimate businesses in this niche - one is left to assume that licenses were arbitrarily denied to anyone who made such a proposal. Small species have a district of their own, which was arguably for their safety, but presumably planned and sized to ensure scarcity of land zoned for them (and thus astronomically higher rents than if larger species were allowed to have them as subtenants). [Answer] "Paying everyone equally for the same work creates the problem that giant people will fall into poverty and little people will gain massive wealth." That's not really how wealth works. If my shirts cost 17 dollars and Bill Gates's shirts cost 32 dollars; he would not be impoverished and I would not be massively wealthy. I admit that there are other commodities that support your point better than clothing does, like different sized housing and different food budgets. But on the whole, unequal cost of living is a somewhat negligible factor in determining who acquires great wealth. Inherited wealth, the ability to leverage wealth to make more wealth, the ability to own factors of automation, and the ability to get paid for the work each of your employees does are much larger factors in unequal wealth. It is also the case that, regardless of size, intellect and skill will be a greater indicator of a person's productivity and earning power. So the correlation between size and earning power would not be 1-to-1. But in certain industries, it may be the case that larger individuals may be more productive, or may be able to fill jobs that smaller people can't (e.g. a 10-pound person may not be able to cook or serve food at a restaurant that caters mostly for a 3000-pound peoples' crowd, with stools that are 10-feet tall). This minor advantage in earning power could mildly offset the greater cost of living. It is also the case that America in the beginning of the twentieth century did not have anything close to resembling equal civil rights for all, nor did it have equal income by race, nor equal income by gender. I'm not sure what the ideological stance of your world is, but in a vacuum, it does not need to be more equal than the real world. However, if the people of your world are actively striving for approximately equal outcomes for people of different sizes, they could take the following approaches... * Decree that certain necessities like food, shelter, and utilities are a universal right. Take public ownership of them. Remove the ability to price them capitalistically for profit, or hoarded. This can especially apply to real estate, which is not man-made, and there's no reason why it should have ever been something people could privately own. Somewhat applies to water as well, but the treatment of water is a man-made activity. * Have labor unions that strive to negotiate wages that yield equal wealth regardless of size. * A lot of wealth in America's economy gets tied-up in corporate assets, bank assets, and personal wealth. For example, American corporations have $1.9 trillion sitting around in cash. Banks own a lot of real estate that has been foreclosed upon with nobody living in it. This is a lot of capital resources that we allow to be hoarded by non-living entities who don't need them; which we could have instead taxed, added to the federal budget, and maybe given back to civilians. In your world, perhaps people of all sizes could write-off various size-dependent expenses on their tax returns, and then their differing needs would be subsidized by the tax code, which would have higher federal revenue than we have, because the corporations wouldn't be keeping any wealth to themselves. [Answer] Your "equality" would never work outside of some sort of dystopian civilization. Rather than making things "equal" your government should be working to ensure things are "equally unequal." If this does not make sense, continue reading. **Complexities between sizing and pricing**. *Manufacturing*: In our world, producing small items is actually difficult and expensive. We can do that because we had to create the technology to do so. That technology would NEVER have developed in this world. In their world, it would actually be easy to make small items but only the small can make these items. Similarly, it has been argued that the ease of slavery deterred tech growth. Because slaves were so convenient. Small people can make things for small people but cannot make many items for the large people. A 3 inch person making a phone, car, or really any item for a 20 ft person is the equivalent of a normal human making a oil tanker or a death star. Even if possible with enough people (and having too many is a human resource nightmare), it is never going to be mass producible. People of size X and X-1 will make items for size X people. There will be some benefits from small people working on electronics for large people, but generally the economy will be somewhat segregated. *Resource Gathering*: Resources are located around the globe, separated by vast distances. A society of 3in or 1ft people would have issues gathering ores and minerals. Transportation and extraction would be difficult. Even if small people can make their own items, they need big people to actually gather and move the raw materials. *Retail*: Stores trying to cater to all sizes would be an utter nightmare. It just would not be possible to keep that stock available. This means either stores are split by sizes, OR stores are just locations to order and have items delivered on demand. **This is not a civil rights issue**. The whole civil rights argument is that a colored (pick one: black, yellow, red, pink striped) man can do the same job as a white man, or a woman the same as a man. A 3 inch person absolutely cannot do the job of a 20ft man, and the opposite is true. They have their roles, and are somewhat restricted by their size. Pretending these people are the same is utterly ridiculous. And any technology you can imagine that MIGHT allow that in our world, might not have evolved or been created in theirs. A completely non-discriminatory (handicap & size based not color) based society is a luxury and is not at all a nature state. Are all people going to be using the same water fountain, road, building, or side walk? A fountain for a 10ft person might drown a 1ft person. A large car may not see a small car and crush it. Would it really be safe to have an integrated side walk and buildings? Everything would have to be made for large people, which would be difficult and inconvenient for small people. Imagine a 15ft person has a 100 step walk between buildings, now imagine a 3ft person making that walk... So assuming you read all of this, you are probably asking "Where is the equally unequal?" Here. Some segregation of the economy and society is expected and should be tolerated. Wanting to force a small person to do a big person's job or the opposite is not what you want. "UNEQUAL." What you should be watching is that no one group is actively, hostilely, and maliciously targeting another. They are all people. They all have the same rights, and even if they have different limitations they need to work together. Big people can't just demolish a little person town, because it is in the way. But little people can't just expect to get in the way of big people. "EQUALLY UNEQUAL" [Answer] Something that is very important to know in that context: robustness etc. of creatures doesn't scale linearly. And anatomy doesn't scale much at all. Most insects will be fine if you drop them from three foot high onto concrete. Obviously, assuming that people two hundred times taller than an insect should take not much damage from a 600 feet drop, or even a 3 foot drop!, would be completely in error. A six foot insect would have the same problem (that's why they don't exist in that size). Fish seem to be an exception, but then they all aren't good at surviving when there is no buoyancy. It's even a problem with objects: drop a blueberry and a watermelon the same three feet .... You might want to be a miser with gravity in your world. [Answer] > > **Same Wages + Basic Needs** > > > You should provide everyone with same base wages and basic needs such as shelter, clothing and food. So no one will get very poor, and a wise spender can become rich. As explained by @david, the small goods and the large goods cost will be somewhat similar as in our real world, people pay same for jeans and mini skirts. ]

[Question] [ He sees you when you're sleeping, he knows you when you're awake, he knows if you've been bad or good, so the NSA wants him to take. Santa Claus' intelligence collection systems are state of the art. The NSA has approached Santa Claus about partnering, but Santa Claus declined due to *ideological reasons* (so what if the NSA wants to use drones instead of coal? What business of Santa's is that?) Anyway, the NSA has deemed it necessary to capture Santa Claus, so they can take over his intelligence systems. Given that he already started [flying under the radar](https://worldbuilding.stackexchange.com/questions/31457/what-if-santa-does-not-want-norad-to-track-him), it is likely that he already knows (of course he knows, he's SANTA!) Remember, Santa is an adaptable foe that presumably has incredibly good intel about the NSA, so this operation will be tricky. **How can the NSA capture Santa?** [Answer] **Have a good kid wish for it.** Santa is omniscient, but still a slave to his chosen mechanics; you need to play by his rules. Create an internal adoption program where NSA officers raise a reasonable number of kids in a nurturing, responsible manner. Tell them how important is Daddy's or Mommy's work at NSA, making idols out of them. Introduce the concept to them: *'Wow, kiddo, Santa is awesome! Imagine if we could join forces and know where the bad guys are!'* It takes one kid with a sincere request: *'Dear Santa, I would like you to help Daddy/Mommy catch the evil guys! Please join him/her at his work.'* [Answer] **Any plan based on secrecy will fail.** If even one person knows about it, Santa knows about it, right? **Any plan based on overpowering Santa will fail.** If a surprise attack won't work, then an attack so powerful that Santa can't prevent it seems like the best alternative. However, there is a small problem with this: how do you capture someone who not only can [move a 350,000 ton load at a speed of 650 miles per second](http://www.daclarke.org/Humour/santa.html), but also has a demonstrable ability to enter and exit locked, secured buildings without even leaving a sign of forced entry? I think it is safe to say that no military force would be able to cope with these abilities. Even a sky filled with drones would be completely powerless to stop an object moving at this speed. Forgetting the first objection above, even if you could launch a surprise attack, Santa almost certainly could simply escape from any ambush without being captured. He could probably even come back to the site of the ambush, deliver presents, eat cookies, and then leave again without ever being threatened. **The best bet is to use threats to secure Santa's cooperation.** The NSA could threaten to do something really bad unless Santa helps them out. It is clear that Santa has a strong preference for goodness over badness and wants to help people, and the NSA could probably take advantage of that to get him to voluntarily agree to cooperate with them. There is no need to speculate what they should threaten; there are many possibilities, and they could try various threats until they find what works. Could Santa stop the NSA from doing the bad stuff? It seems unlikely, since lots of stuff that Santa doesn't like already happens in the world, and he other does not or cannot use his Christmas magic to stop it. Could Santa expose the NSA's plan? He could only do this at great cost to himself. He would have to: 1. Announce his existence to the world. 2. Demonstrate his magic powers to prove his identity (otherwise he would not be a credible witness). It is possible that Santa would think this is worth it, given the circumstances. However, it is equally possible that he fears that the consequences of such actions would be much worse than cooperating with the NSA. If he reveals himself to the world, it would lead to all of the crazy, evil people in the world trying to capture him and use his power to their advantage. They know how to find him. While he might not be catchable, it would probably put an end to the whole present-delivery thing. So I think there is a good chance that he would give in to the NSA's threats and cooperate. **Addendum: why the NSA should worry about their plan.** Santa's non-intervention in most world affairs, despite being a deep philosophical conundrum, should raise some concerns in the NSA. Why doesn't Santa replace all the guns in Syria with teddy bears overnight? Why doesn't he airlift food to starving populations? Why doesn't he voluntarily share at least some intelligence (if not with NSA then with others he trusts more) to stop bad things from happening? Actions such as these seem easily within his capabilities, and they also seem to do much more good than the comparatively trivial act of distributing toys yearly. I see two main possibilities here: 1. **Santa doesn't intervene for philosophical/ideological/moral reasons.** He follows a code that requires him to only do Christmas, and not participate in world affairs otherwise. This is problematic, as it appears to make Santa into a moral monster. However, it could be possibly justified philosophically. Perhaps Santa believes that all of these other interventions, while seemingly good, would actually do harm in the long run. Call it the "add toys to make it the best of all possible worlds" theory. *In this case the NSA should worry, since Santa might choose not to intervene to stop the bad stuff they threaten. However, he might be responsive to threats to disrupt Christmas.* 2. **Santa's power only applies in limited circumstances.** The magic doesn't work for everything, but has some limitations that make it impractical to apply to non-Christmas-y objectives. *In this case, the NSA should worry that Santa might not even be able to help them. However, there are possible sets of limitations that would prevent Santa from intervening in world affairs generally, but still leave him able to share intel with the NSA. Any limitations to Santa's powers also create some new possibilities for capturing him, so the NSA should research this fully before proceeding.* [Answer] # Option #1: Drones The NSA gets drones, military drones, to cover the airspace in a particular area. Cover it so well that St. Nick can only do one of two things: get caught, or don't deliver presents. (We hope Santa shouts "YOLO" as he does this.) The alternative is to devise drones which will figure out how to coordinate on their own to make such a trap. The trick here is that Santa will not let down the good girls and boys in this area, so we need to choose an area to set the trap in. He comes to us, and we recruit him for the greater good. [Excellent](https://youtu.be/_crvGziPn3g)! # Option #2: Santa Trap This Santa trap is just like a monkey trap, except there is a cookie in there.[](https://i.stack.imgur.com/oP9B1.png) I can only hope that a man *who is generally known as a saint* is as greedy and stubborn as a monkey when it comes to nibbling every cookie set out for him. (Okay, you need to monitor this trap. I'm sure he'll just let it go at some point.) I suggest setting out some milk so he doesn't suspect anything until it's too late. # Option #3: Recruit Santa Seriously, we know Santa lives at the North Pole. Just go visit him and try to convince him that helping the good(?) folks at the NSA to good(?) things. "We just want access to your lists and what you see people do... All. The. Time." I *suppose* the NSA can offer to help him sort people onto "naughty" and "nice" lists. As a final note, glove and boots has shown us [Santa may have backup](https://youtu.be/tb9Cm90gWGw). [Answer] Trapping Santa is easy. All you have to do is drug the cookies. The difficult part is getting the cookies onto a plate near the fireplace of even one good little girl or boy. They have to come from good little children, after all, Santa's no fool. He doesn't eat cookies from bad children. Would You? At best such cookies would be attempted bribery and at worse, they could be poisoned. Yes, Santa could see the evil on each cookie giver's soul; but it's hard to distinguish between a future serial killer from a current poisoner. So why chance it. Therefore, the drugged cookies have to be given to him by good little children, but drugging Santa is evil. A child can't be good if they are complicit in an attempted Santa-napping. ...and ignorance is no excuse. Even if the child doesn't know that the cookies are drugged, their shared guilt is enough to knock them off the nice list. It's a catch-22 that NSA's top strategists have been working on since last Christmas. It's not just their jobs or their current assignments. They want revenge for all those long years of nothing but coal. [Answer] Santas location is already known. Children write their wish lists and [mail them to Santa](https://en.wikipedia.org/wiki/Santa_Claus#Letter_writing_to_Santa). It would be trivial to follow the delivery company. Worst case scenario, you find a Santa mail sorting depot. However, the elves working there would likely talk when under pressure. I doubt Elves are trained to withstand torture. [Answer] Ignorance First you start with one person having the idea and telling no one. Then he comes up with a code name that like operation bluebird. Assigning people as if it was a training exercise, with no one knowing who the target is. The trap could be a safe house with steel shutters and bait it with several of the most innocent kids you can find having a fun sleepover. Once Santa goes down the chimney seal it off and close all the shutters. By keeping it a secret from everyone, Santa won't be able to know about it first, as everyone involved has a story about making a safe house to protect people. **Edit** The mastermind could get help brainstorming a better plan but making it a training exercise. There is an [anti-zombie](http://www.cnn.com/2014/05/16/politics/pentagon-zombie-apocalypse/) plan in place why not a just for fun plan to catch Santa. [Answer] **Option 1: Magic** In a world where Santa is real, magic is real. NSA needs to find other magic-users (it wouldn't make sense if only one person could use magic in a world of magic, so it's safe to assume there are other people capable of magic in the world). NSA needs to recruit these magic-users and use them to do either: 1. Develop an intelligence collection system that is as good as or even better than Santa's intelligence collection system. The need of catching Santa goes away if they do this. 2. Use magic to capture Santa. If other magic-users can become as powerful as Santa, they might be able to capture Santa using their magic and powers combined. Even if they are unable to become as powerful as Santa, they can have strength in numbers. Santa is just one guy after all. **Option 2: Break into Santa's home** Another option is to locate Santa's home on the North Pole. This plan will only succeed though if Santa's home isn't protected and/or hidden by magic. The NSA will travel to the North Pole and break into Santa's home to either: 1. Capture Santa when he's home or even better: go to Santa's home when he's out delivering presents and wait for him to return to capture him. 2. Steal Santa's intelligence collection system (assuming it can be moved). 3. Capture Santa's home and turn it into an NSA-controlled base. They will also have control over the intelligence collection system this way. What they do with Santa doesn't really matter now, they could either keep him as prisoner, dispose of him or just kick him and keep him out of his former home. 4. Steal the plans and designs of Santa's intelligence collection system (assuming Santa still has those in an archive of some sort) so NSA can build a copy of the intelligence collection system. [Answer] The OP states: > > *The NSA has approached Santa Claus about partnering, but Santa Claus declined due to ideological reasons* > > > I do not understand what "capturing" Santa would do to change that refusal to partner with the NSA. Even if they had him caged in some kind of anti-Santa-magic force field, they could not make him do anything that he felt was wrong. So, it would seem more effective to just go back to talking to Santa to determine what kind of help he IS willing to offer the NSA in the way of stopping bad guys while asking him what he would like in return from the NSA to promote "Peace on earth and goodwill toward men" all year long. (And it wouldn't hurt to get a bunch of good kids from families of our more hawkish Congressional members to put that trade agreement on their Christmas list. That would have double impact.) :) [Answer] Christmas is a federal holiday. Congress can change and/or cancel it. This is how the NSA puts the squeeze on Santa. The NSA director walks in to a closed session of the Senate Intelligence Committee and makes a classified report on the ISIS-Santa link. Congress gives in and swaps Christmas with Independence Day. If Santa tries to deliver presents on Independence Day, he gets shot down by the fireworks. He can't deliver presents on Christmas because the elves will not have had time to finish them and the reindeer can't fly in the heat. [Answer] This could spell the end of NSA, CIA and other collaborators. If they try to squeeze Santa, he will use the Christmas spirit, to make people be good, both in themselves and unto others. If they try to attack Santa, the Christmas spirit will make them see the error of their ways, or feel compelled to be good. They will leave their jobs, or maybe convince the rest of the service of the importance to be a good person and not do harm to others. This will spell the end of the services. [Answer] His data-center is in Antarctica. His elves have figured out how to genetically modify reindeer to be bulletproof. He performs billions of robberies in one day. Any attempt to take his data will result in Santa knowing. Whenever you attempt to make a plan, Santa is aware and will protect against it. # It's not possible to stop Santa. [Answer] *ASIA*, the *Anti-Santa Intelligence Agency*, recommends: ***Kidnap an elf and use it to control Santa!*** Seriously, elves are a weak link and therefore a perfect attack vector, allowing further operational exploitation. Getting a hold on just one of the elves would provide the NSA with the strong emotional trigger they need to make Santa do whatever they want. After all… while there’s a chance Santa is a big fan of puzzling, he surely would not like having to glue back together 1000 pieces of an elve. ;) Ease of operation: as the following intel imagery clearly shows, Santa’s elves are vulnerable to be subverted via usual digital channels using current NSA equipment without the need to specifically (re-)infiltrate services like Google Mail. Based on the known, average intelligence level of the potential targets, setting up and abducting an elf should be a piece of cake. [](https://i.stack.imgur.com/iCA1R.jpg) According to classified sources, CIA might be able to assist leveraging the pressure on Santa as soon as the elf is in custody. They seem to have a long history of operational success in related areas. For the records: officially, it can neither be confirmed nor denied that NSA/CIA cooperation can and/or will result in any kind of elf abduction, psychological forcing, and/or successfull Santa capturing. ]

[Question] [ **I'm having a very hard time justifiably spending lots of time building a world of my own.** On one hand-- I express myself very creatively, and even browsing through this site gives me a plethora of ideas. However, whenever I start to consider what a world might look like, despite my fervent desire to create an intriguing and compelling history, I get lost in the dread that I could be doing something that isn't entirely productive or unique. I understand that I might be looking for too much out of this experience, or that I could have already answered my question (world-building is used as a creative outlet-- it isn't supposed to be productive etc.), but I have such a strong desire to actively participate in this incredible community I've witnessed that it feels bad either way. Is there anything that y'all have used to justify the amount of time that could be spent creating something like this? Am I just looking at the concept wrong? *Note: Please tell me if this question is out of place. I'm very new to this website. Thanks!* Edit: Thank you so much for all the responses! I believe I originally misconceived the notion of world-building as an all-encompassing creation, not a casually enjoyable, incrementally added upon, pass-time. Specifically, the responses that encouraged how the creation process is just as fulfilling as the finished result helped me decide to work on world-building as a hobby, rather than a full commitment. Perhaps my initial concern was just my inner completionist getting the best of me. Thanks Again! [Answer] World building tends to attract certain types of people * People who like the process of world building * People who go the extra mile in making sure their story is accurate * People who want a single base world so they can have multiple, possibly interwoven, stories with the same setting * People who are anal about details There's nothing wrong with only world building the bare minimum. Plenty of great stories have minimal world building, you just have to choose a balance that works for you. [Answer] Here's the way I look at it; when you build a world (for your story / game / amusement / insert purpose here) you're not doing it for yourself per se; you're doing it for the experts in the fields you'll discuss that will also read / play your work. The whole Skynet thing in the Terminator (for example) bugs the daylights out of me. Why? Because I'm an AI researcher (among the many hats I wear these days) and I know it just can't happen like that, and that if you're going to build machines that wipe out humanity, you don't need to make them smart. Judging by the number of downvotes I get when I discuss this topic even on this forum, there are a lot of people out there who have a differing view, and that's probably why shows like the Terminator are so popular. But, to me it's not realistic. So; you can build a world with minimal effort but write in engaging characters and an intriguing plot, and you'll produce something that has every chance of being popular. But, realistic? Well perhaps, but then not to the people who actually know the details of the mechanics behind the world you've created. Ultimately, the effort you go to in creating a world should be commensurate with the level of expertise in the areas around which your world is created that you wish to engage. If you just want the laypeople, then it's a waste of your time and effort and you can (quite rightly) say that it's unproductive. For mine however, I prefer the story worlds that go the extra mile to make it realistic **to me** and to other experts in the chosen fields of discussion. That effort won't be recogniseable to everyone and I have to say that your return on investment may be a lot lower than appealing to the masses, but quality counts, at least to me, so my view is that it's always worth the extra effort because your reward isn't the number of extra people you draw, it's the amount of knowledge you draw by virtue of that effort. [Answer] ## World Building is Entirely Unnecessary. What justifies the time is writing with consistency. If you have a map with terrains, towns, plausible climates and climatic cycles, etc, then your writing will be consistent as your characters journey through it; you won't accidentally write in logically impossible distances or trip timing. Using Earth as an example, you won't write that the trip from Las Vegas to New York City took 8 hours to drive. It is 2529 miles, they'd have to drive 317 miles an hour! Of course you wouldn't make that mistake on EARTH, even if you aren't great at division you would immediately sense these are further apart than 8 hours, and consult a map and calculator. But when you are writing and inventing everything yourself, it can be easy to forget what you told the reader about places W, X, Y, and Z, and accidentally create a physical paradox like the above. It takes one crew a day to walk the path W->X->Y, stopping at X on the way, because that was convenient to your plot at the time. Then later in the book you send them from Z->Y->X for supplies, and it takes them FIVE days to walk from Y to X. WTF? They walked from X->Y in less than ONE day the first time! You might have character Joe talking about being born in W, and growing up with snow, ice, and bitterly cold winters. Then three months of writing and ten chapters later, you forget about that. Joe and your crew end up in W during winter, and you write it as pretty pleasant and mild. But your **reader** just read about the winters in W a few hours ago, goes back to read that again, and wonders a) Why Joe and nobody else isn't saying a damn thing about this pleasant winter, and b) Was Joe lying? In such a case you have broken the reader's immersion, your world doesn't make sense because your writing is glaringly inconsistent. ### But I said world building is entirely unnecessary! You don't have to do this kind of work up front; you can take notes of what you say and build a map as you write along, and if necessary revise your story as you go. If you know some of the **elements** of world building (what makes deserts, or rain forests, mountain ranges, lakes, etc) then you won't make obvious mistakes, but all you really need to avoid is **glaring** errors that won't stand up to scrutiny. You don't have to talk about the geology of what makes a seashore cliff; you can just plug in a seashore cliff. Just Google "seashore cliff" and you will find a few dozen of them, pick one that best fits your story as a reference for writing your own. Describe actual nature and you won't create any glaring errors. Of course world building can also include fantasy religions, cultures, rituals, animals, magic systems, and so on. Some of these are for entertainment value, others are developed in order to maintain consistency, and impose limitations on what can be done. Not only in magic, but perhaps politically and culturally as well. In many fantasy and scifi worlds the culture allows one character to kill another in front of witnesses and walk away, never to be pursued or even charged; there just is no law enforcement in such worlds other than vigilantism. In other worlds more like our own, like the Mr. Robot series, law enforcement and how it works is central to the story, the hackers are breaking the law and in constant fear and danger of being caught. World building can be an entertainment in and of itself, but (IMO) it is just a setting, not a story. To me, I would rather write a story. I am a discovery writer, so I do my world-building on the fly, with a map I sketch as my story demands new places, towns, or features like rivers, oceans, forests, deserts, etc. I also do several passes through my finished work, and along the way ensure my elements are consistent and there are no glaring errors. The advantage of world building up front is your story maintains consistency and you don't have to invent settings on the fly. However, you can do these things on the fly without ever sitting down to invent your world. If your story is character-driven, like mine, the settings are not necessarily a big part of the story; and (for me) the main thing to keep straight is distances, travel times, and at times for the physicality (traveling or fighting) and dress of characters, whether it is freezing, sweltering, or fair weather, open terrain or forested, watered or dry, etc. If setting is a major "character" of your story and often plays the villain (heroes versus nature, or culture, or politics) or has entertainment value (tourism for the reader, by terrain and/or cultures) then it should probably be planned and made consistent. The time justification is in whether it is more efficient to design the setting and then write a story in it, or to write your story and design the setting on the fly, keeping it consistent with notes and sketches. That all depends on how important the world ***is*** in your story; and for many stories that focus on the emotions of characters (a relationship, falling in love, coming of age, dealing with loss, etc) the setting is not terribly important. [Answer] Think of it like learning the skills so you can build your own house, and then you start building a house that you poke away at when you have the time. It seems like it takes forever. You might never finish the house. But then, one day, you're visiting a friend and they mention they've got a leak and are going to have to call a plumber. As they describe the problem, you realize you've learned enough doing your own plumbing that it's an easy fix. No need of a plumber, you can show your buddy how to fix it themself. Never could have done that if you hadn't worked on your own, seemingly never-ending project. Working on your own gives you skills that you can use in other situations. [Answer] **Building a world often leads to more story options.** The first example that comes to mind is the *Star Wars* universe. Stories have come out of that "world" since 1977: movies, books, TV specials, animated TV series, fan films, board games, card games, etc. (Don't get me started on merchandising!) Another world that led to story options was mentioned in the answer Caleb Koch offered: J.R.R. Tolkien's Middle Earth. *The Hobbit* set up the world, and then it was explored in amazing depth in the *Lord of the Rings* trilogy. (Fans can probably list other *LOTR* works that I don't know about.) There are many current examples of worlds spawning stories as well: *Game of Thrones*, *Transformers*, *Star Trek*, Stephen King's *Dark Tower* world and series, the Marvel and DC Comics universes, and on and on. So the process of building a world is not frivolous or a waste of time. It can be a "primordial soup" that spawns life and aids your creativity. [Answer] Depends on what you are using it for? a book, game, personal. For me anyway, I like detail and realism about my worlds. I like my worlds to feel like they could be lived in, but I do this not for myself but for other people to enjoy, that will change how you build your world. If it’s for yourself then you don't need to get hung up on too much detail because you know the world rules all ready (you built it after all) but if it for others then you need to act like they have no idea what your world is, so you need to show them. Don’t go for too much detail (been there) too much detail can drag your story too long and that will bore your readers. The time is your to spend, build whatever fits YOU and most of all have FUN [Answer] There are few excellent answers, but there is one point I see missing in them. World building is a real challenge for your creativity. You have to enforce yourself to think of multiple ideas that will make your world interesting in some way. As you have mentioned, one of the things you'll be trying to achieve is to have a world that in some way is unique (that is no-one else came with this idea yet). So it has to be a creative process This is a benefit that works for you in general. The very same creativity can later work when thinking of finding some real-life problems. And creativity and imagination like every other skill gets better when trained. So even though you might be doing the world building just for your own sake and the world you build is not going to be shown to anyone, you will benefit from it anyway. That's particularly my reason to participate in WorldBuilding StackExchange. I don't feel a need to build a world as such but I like stretching my creativity answering others' questions. [Answer] The answers already here are great and valid, but I just wanted to add that when writing a story, having a complete, believable world for your characters to live in helps to make the characters themselves more believable and complete. Even if the characters never really understand why they can't jump into hyperspace near a large planetary body or what the consequences might be, with a complete and consistent world, you as the author know exactly the reasons why. Those reasons will be ever present in the back of your mind as you write, and will influence the events in the story as well as the characters actions, leading to more well-rounded characters, and makes it that much easier for a reader to lose themselves in the story. [Answer] Tolkien, arguably one of history's greatest world builders, seemed to have a similar question. May I direct you towards his work *Leaf by Niggle*, or at least towards Wikipedia's summary of the work (<https://en.wikipedia.org/wiki/Leaf_by_Niggle>)? I won't ruin the story for you, but I will say that Niggle's life is essentially an allegory of Tolkien's own life and work. *Leaf by Niggle* can be interpreted as an "illustration of Tolkien's religious philosophy of creation and sub-creation. In this philosophy, true creation is the exclusive province of God, and those who aspire to creation can only make echoes (good) or mockeries (evil) of truth. The sub-creation of works that echo the true creations of God is one way that mortals honour God." An interesting view indeed, wherever you fall on the God debate. [Answer] **You could make it a part of your story building progress.** Every time you come up with new ideas for your world, they're probally joined with a few basic/rough ideas of what could happen in this part of the world. If you write those down you could use that as material for your story. More prep could create a more stable story, less plotholes and some depth. Even if a reader doesn't really care about all the lore around it, they'll still feel the story being solid. [Answer] I think the real question is, why does it need to be justified? There are a plethora of hobbies that have much less to offer as far as what you have to show for it. If there are things you should be doing instead, do those things and come back to your world when you have more free time. However if your world is the setting for a story you're writing, then I would consider that a justification in and of itself (assuming this is a legitimate goal and not just a hobby in it's own right). If you find yourself filling out your world more than is necessary for your story, then get to a stopping point, work on what needs to be done for your story, and again, come back to the world when you've got more free time, or need to flush out more of the details. Source: I have quite a few hobbies and very few have much to show for the time I put in, especially compared to world building and writing. It all comes down to what makes you feel productive. [Answer] What do you do with your world? * You might want to tell stories in it, and hope to become the next great SF/F writer. You need good prose, a riveting plot, believable characters, and also a memorable world. Usually two or three out of four is not enough. * You might be the game master of a pen-and-paper roleplaying group. You sit around the table all Saturday until 0-dark-30 with a bunch of friends and many gallons of chips and cola. Those pesky players, they get ideas you never had. The best way to improvise along with that and keep it fun for everyone is if **you know your world** and if **they understand your world**. > > *"Does the castle have a rear exit? How is it locked?"* > > > *"No rear door." (I want the big fight in the castle yard.)* > > > *"How about the [garderobe](https://en.wikipedia.org/wiki/Garderobe)? Can we hack the planks out and rappel down?"* > > > *"No garderobe." (I still want the big fight in the castle yard.)* > > > *"What!?"* > > > [Answer] My viewpoint may be a little different in that many people tend to work from the top down. They start with a world and fill in the details. I work the opposite way. I have an idea and then think what I need to know about its world to make it plausible. I may never go on to develop the world more than that. For me, being challenged by the community to make my ideas clear is a great intellectual exercise that offsets my bubbles of creativity. By researching the subjects and discovering similar previous questions, I improve my knowledge and hope to find myself better at answering the questions of others. I'm sure you don't have to justify enjoying yourself as long as it doesn't become an obsession that interferes with your real life. ]

[Question] [ So the U.S. President (or some other country's leader) is strollin' along. I blast him with a duplication ray gun (secret service must have been snoozing). There are now two of him. How does the world react? * The two copies are identical at the moment of duplication. It's not like an evil twin or anything. + Both think they are the original. Indeed, neither one is really more original than the other. + They can, of course, diverge after the duplication. Given that the president is at least 35 years old though, it's not likely they would develop different personalities or anything. + Anything he is wearing or holding at the time is similarly duplicated. + The only difference is that one appeared on the left, and one appeared on the right. Other than that, there's no distinction. * There were a lot of witnesses. * This is the first known use of duplication outside a laboratory (where it was generally done on atoms). * Just for fun, let's say the President is known for ambition and being power hungry, treating anyone who challenges his power, including those with similar goals or principles, as a political rival or threat (but is otherwise a typical leader). My question is, what happens to the U.S.? Reelection? Dual-Presidency? And which one of them is the man that woke up that morning, for legal purposes? What precautions would the world take to prevent similar or repeated instances? Note: Although the leader is ambitious, he's not extremely ambitious. The point is that he thinks more in terms of power than political alignment, and doesn't like sharing power. He isn't any more violent or corrupt (sans not caring about political principles) than any other politician. [Answer] You would be arrested. Both Presidents would be isolated away from each other and taken into custody. **The Vice President would take control of the country.** An unidentified attacker just used completely unknown technology to do something to the POTUS that no one thought possible. If you were lucky enough to not be shot dead on the spot, you would be taken down, restrained, and shipped off site for interrogation. The Secret Service would be momentarily stunned by what is almost certainly an unplanned scenario, but given the circumstances, both Presidents would shortly be separated from one another purely for safety's sake. They would be shepherded off to secure sites and quite likely restrained in the process. Who is the real president? The Secret Service certainly won't know. As exact copies no amount of verbal questioning or physical inspection is going to help. Under no circumstances would either "President" continue to act as the Commander in Chief. The POTUS was just attacked. Something unimaginable happened to him. Even if certain members of the government wanted him to continue to carry out his duties, no one could be certain who was the real one. The simplest solution, at a time when military high alert would be boiling over, is to allow the singular Vice President to assume the presidency. After that, there would be some disturbing questions with even more disturbing answers. Once the government is stabilized, an unprecedented investigation would occur. Your ray gun would be classified and shipped off to Area 51 or another lesser known black site for study. Both Presidents would undergo thorough interrogation and medical study. By this point, there is simply no circumstance in which either of them will continue to be involved in the government. The President's family would experience a severely trying period in which two separate, but equal, people claimed to be their loved one. The world would wait for answers, but would receive none that satisfied its questions. There's much more that could be said about the future fate of the former Presidents, but it strays beyond the scope of the question. [Answer] **Imagine this from the point of view of the president(s)**. After some initial bewilderment, they assess the situation rationally. Their primary motive is to retain power. And, while each may view the copy of himself as a threat to this, they quickly realize that the primary threat is that they both will be removed from power completely due to the instability the situation creates. Therefore, **they have a strong incentive to cooperate**. **They quickly agree that the vice president should take control of the presidency temporarily**. The fact that they make this decision, rather than it being imposed upon them, means they are still in control of the situation. They are able to frame this as temporary incapacitation, similar to the president going under anesthesia for surgery, creating the expectation that they will resume power as soon as the situation is resolved. **Now that the immediate crisis is averted, they work together on a solution.** Note that I don't think it likely that they will be separated, locked up, etc. Everyone is confused and doesn't know what to do in this situation. Arresting the President of the United States is not the sort of thing one does unless you are *absolutely certain* that it must be done. This is career suicide, and the people close to the president got there in large part due to their deference. Absent a clear, immediate threat, this is just unlikely to happen. When the two presidents start discussing the issue, **they realize that they immediately agree on everything.** In fact, [they often start saying the same thing at the same time](https://worldbuilding.stackexchange.com/questions/31705/how-to-defeat-exact-copy-of-yourself). Each realizes that the other being in power *is practically indistinguishable from himself being in power*, since the other does exactly what he would do anyway. They lose a desire to compete for the spot, and in fact **each ends up wondering whether it would be better for the other to have the top office**. They would still get everything they want out of the presidency, while having a lot more freedom. (In the end, they both realize they still want to be president, but they don't feel so strongly about this when it is an exact copy of themselves in the job). They realize the impossibility of shared office, so **they decide on a coin flip who will be president.** The other one will, however, still take an active role as an "adviser". Government and the public happily accept this solution. The one selected as president is given a prominent tattoo in order to prevent any future crisis of identity. **Everything is great...until their divergent lifestyles cause their personalities and preferences to diverge.** That is when trouble starts brewing... [Answer] **Denial.** You might think there would be no way to deny an event like this that was widely seen on television, but it's such a surprising thing to happen that people would be reluctant to believe. And American politics *loves* conspiracy theories. The event is immediately declared Top Secret. The news agencies are reminded that it's extremely illegal to talk about it. They cut away from the breaking coverage, briefly state that it appears to have been a hoax, and carry on as if nothing had happened. White House staff are told that for anti-terrorist security reasons the President now has a body double, like [General Montgomery](https://en.wikipedia.org/wiki/I_Was_Monty's_Double_%28film%29). The President now appears to be getting a lot more work done. White House press releases contradict one another a bit more than usual. Nobody notices. The President's family are confused by his apparent short-term memory loss. His wife suspects he is having an affair. This might even be true, but he has the perfect alibi. Would the President compete with himself? Absolutely. But he'd do it covertly, like he's done his whole career. Once one of them is sure he has more loyalty from his secret service team than the other, he can strike. A presidential event is disrupted by a lunatic with a gun, as happened to Lincoln, JFK, Reagan. The President is shot at close range, but thanks to heroic medical efforts he survives and makes a full recovery. But he doesn't seem to have a double any more.. [Answer] With my tinfoil hat firmly in place, I think the most obvious answer is that regardless of the number of witnesses, there would simply be a coup. One or both of the Presidential duplicates would be quietly killed by the CIA and the VP would take over the running of the country. You've stated that there were lots of witness, but what did they witness? Someone used some pyrotechnics to try to abduct the President and replace him with a doppelganger. It failed and both the Pres and his double were killed in the ensuing gunfight. I blame ISIS. [Answer] While this would be novel, the almost certain response would be to pick one and make that one the current legal President. There is zero provision in US law for copresidents, so that would be a non-starter. One or the other would have to be selected. There is no provision for scheduling a midterm election, so this would almost certainly be done judicially. Coin flip is as likely as any other method. Or I suppose we could let the First Spouse choose. There is a very small chance that both would be disqualified and the Vice-president would be promoted. If done in the President's second term, it's possible that the one who does not stay President might run for another term. It depends on that person's exact legal status. Are there now two people, one of whom was and is the President? Or had both been President and only one is now? If the former, then the one who is not President could run for President without worrying about previous terms limiting eligibility. If the latter, then one is essentially losing a chance to be President. I think the latter interpretation is more likely, but anything could happen. If this happened in a President's first term, this creates an interesting situation. One could be President while the other runs for President. Then the one who doesn't run then could run in four years. So three terms between them, even though both lost a term of eligibility. Or they could be considered the same person and limited to two terms between them. The former seems more likely, but anything is possible. Note: I'm generally ignoring issues not related to the presidency itself. For example, most Presidents have been married. Which of the duplicates is married? But that seems worthy of its own question. [Answer] Both would have a claim to the presidency. Since both are ambitious enough to become president, neither will let go of the job without a fight. Nor will they cede the power to the vice president, who may try to oust them as well. When two people have a claim to the presidency, [the Supreme court decides](https://en.wikipedia.org/wiki/Bush_v._Gore). Courts in America have been known to decide exactly equal elections with a coinflip, and since there is no possible other basis to decide here, the supreme court will do the same here. Given this, there are two possible outcomes. The first: each copy is satisfied with a fifty/fifty chance, and they take their shot. The loser walks away with nothing but a lifetime of lucrative public speaking engagements. Second, a 50% chance of losing their life's work is too much to bear, and the copies decide to work out a power sharing agreement. One copy stays president, and the other gains no official power, but negotiates a deal to make up for it. For instance, he becomes foreign secretary in a few months, and when the first copy has served his two terms, the second copy runs for office with the first's backing. To ensure a fair deal, they set up the conditions first, and then flip a coin to decide who gets which half of the deal. [Answer] A duplicated president, no matter his/her good/neutral/evil alignment could still exploit the situation to get things done. The whole affair is immediately hushed up. (You stipulated a lot of witnesses, but that is not necessarily a barrier, and makes revelation more interesting.) More duplicates are made, if possible. (A secret government program begins to clandestinely copy service persons in some special command unit, if possible.) The dupe presidents leverage his/her newfound ability to seemingly be in two places at once to affect a supernatural power to travel great distances instantly. This is used to intimidate enemy heads of state, but the masses are led to believe s/he is a conventional president. Additional psychological games can be invented to unhinge adversaries with feigned godlike powers, especially the appearance of having survived a clearly fatal attack. World peace is ushered in by this creepiness behind the scenes of politics. [Answer] Pretty much what happens in The Santa Clause 2 - namely, that both Presidents enter into a state of conflict over who's the executive. Now, the question becomes, does either President have an alibi that can testify to his authenticity? Does it just so happen that a person or camera, say, saw you escorting the fake president to a more secret location to await the arrival of the real President? Failing sufficient evidence pointing to either President, the government is now in a bit of a dilemma. As the US Constitution, to my knowledge, does not currently prescribe a course of action for this event, either one of two things would happen: 1) As stated above, both Presidents would agree to allow the Vice President to assume the office of President 2) The US & state legislatures would ratify a Constitutional amendment to solve this and future similar contingencies. They might choose, for example, to make the Vice President assume the role until the federal government can figure out who the true President is, or until his term is up. [Answer] I think the other answers are missing a very clear issue that's not specific to the fact that he's the President of the United States: only one person may legally be considered to be themselves. If it did come to the point that the issue had to be dealt with in public (as opposed to the government covering it up and coming up with an extralegal situation privately), there would likely be a court case (in what juridiction, I don't know) to determine which of the two individuals claiming to be Barack Obama (or whoever) is actually Barack Obama. Unless Congress passes a law to address the situation (which they may) the second, unrecognized Barack Obama would become a stateless person with no identity, and no claim to the presidency. The "real" Barack Obama would continue his presidency legally unencumbered, though I can't imagine what the public reaction and political fallout might be. Of course, the situation could be simplified somewhat if Barack Obama is legally removed from office as president. This could be done by both men simultaneously resigning (because regardless of which is the "real" one, you know he resigned), or if the [25th Amendment](https://en.wikipedia.org/wiki/Twenty-fifth_Amendment_to_the_United_States_Constitution) is invoked, both men simultaneously submit a letter under Section 3 (same reasoning as resignation), or, the simplest solution, a majority of the Vice President and cabinet determine Barack Obama unable to serve and thus make the Vice President Acting President. ]

[Question] [ Many people know that our blood is red because it is iron based. Many people also know that blood is blue or green if it is copper based. I'm wondering what color blood would be if it was let's say aluminum or tin based? How could I achieve white or black blood? Colors I'm curious about * Black * White * Orange * Brown * Yellow Metals I'm curious about * Tin * Aluminum * Platinum * Gold * Silver * Cobalt * Nickle * Zinc Don't worry about the effects or problems of the colors or metals that will be a separate question. [Answer] There are [many proteins that transport oxygen in the terrestrial biosphere](https://en.wikipedia.org/wiki/Metalloprotein#Oxygen_carriers), [this](https://en.wikipedia.org/wiki/Hemoglobin#Analogues_in_non-vertebrate_organisms), and [this](http://www.xenology.info/Xeno/10.4.htm). One thing to note is that *at human body temperature, atmospheric pressure, and Earth's atmospheric concentration of oxygen* Hemoglobin is by far the most efficient oxygen transport protein among the list included in this post. It varies from 50% more efficient to 10x more efficient than the other oxygen transport molecules listed here. [](https://i.stack.imgur.com/uqIA3.gif) ## [Hemoglobin](https://en.wikipedia.org/wiki/Hemoglobin) Hemoglobin uses iron as its metal atom. We are all familiar with hemoglobin and **its color red**. ## [Hemocyanin](https://en.wikipedia.org/wiki/Hemocyanin) Hemocyanin's can be found in certain mollusks. **It is colorless when not transporting oxygen and blue when transporting oxygen.** Hemocyanin uses 2 copper atoms in its protein structure and the protein is very similar (but not identical) to hemoglobin. ## [Chlorocruorin](https://en.wikipedia.org/wiki/Chlorocruorin) Chlorocruorin's uses $Fe^{II}$ as its metal ion. > > A dichromatic compound, chlorocruorin is noted for appearing **green** in > dilute solutions, though it appears **light red** when found in > concentrated solutions. > > > ## [Hemerythrin](https://en.wikipedia.org/wiki/Hemerythrin) Hemerythrin uses $Fe^{II}$ Hemerythrin is an iron bearing oxygen transport protein often found in the muscles of marine invertebrates. > > Hemerythrin and myohemerythrin are essentially **colorless** when > deoxygenated, but turn a **violet-pink** in the oxygenated state. > > > ## [Erythrocruorin](https://en.wikipedia.org/wiki/Erythrocruorin) Erythrocruorin is an iron bearing protein. I didn't find definitive description of its color but I think it would be a **light red.** > > Erythrocruorin is a large oxygen-carrying protein, whose molecular > mass is greater than 3.5 million Daltons. It is related to the similar > chlorocruorin. It is found in many annelids and arthropods (including > some insects). > > > and Earthworms. ## Pinnaglobin > > Only seen in the mollusc Pinna squamosa. **Brown** manganese-based > porphyrin [oxygen transport] protein. > > > ## [Coboglobin](https://en.wikipedia.org/wiki/Coboglobin) Coboglobin is currently a synthetic protein that performs the same function as hemoglobin. It uses Cobalt in place of the iron atoms. > > Blood of this type would be **amber yellow** in color when in the veins > while **uncoloured and clear** in the arteries. > > > *It might make an interesting blood for synthetic biological organisms (like the one found in the movie [**Aliens**](https://en.wikipedia.org/wiki/Aliens_%28film%29))...* ## Chloro-carbonyl-bis(tri phenylphosphine)-iridium An Iridium (one of the [Platinum Group Metals](https://en.wikipedia.org/wiki/Platinum_group)) ion based molecule that is **yellow when oxygenated and dull orange when not**. It provides the additional capability of serving as a hydrogen transport molecule too - which might make for interesting biology on a gas giant planet. The organism would require a biological/chemical pathway to generate oxygen from chemicals found in the environment and then transport that molecule to the cells that needed energy. Perhaps the oxygen circulatory system and hydrogen circulatory system would need to be separated? > > In solution, the compound takes up one atom of oxygen per molecule to > change from brilliant yellow to sullen orange... > > > In the oxygenated condition, the iridium-based blood of > extraterrestrials would have to be protected from light because it is > very photosensitive. The pigment slowly decomposes over a period of > days or weeks when exposed to strong light, gradually changing color > from orange to green and finally to a deep bluish-black. Such aliens > would therefore either have very dark skin, or would inhabit a dimly > lit world. (In the absence of light, the molecule is stable for > years.) > > > The iridium complex has one additional property which is extremely > fascinating to xenobiologists. In addition to oxygen, the molecule is > also capable of reversibly binding hydrogen as well! > > > ## In Summary * Pink (Iron - Hemerythrin) * Red (Iron - many) * Orange (Iridium - chloro-carbonyl-bis(tri phenylphosphine)-iridium) * Yellow (Cobalt - Coboglobin, Iridium - chloro-carbonyl-bis(tri phenylphosphine)-iridium) * Green (Iron - Chlorocruorin) * Blue (Copper - Hemocyanin) * Violet (Iron - Hemerythrin) * Clear (Cobalt - Coboglobin, Iron - Hemerythrin) * Brown (Manganese - Pinnaglobin) All but two of these (the exceptions are the Cobalt and Iridium based molecules) are known to exist in living organism in the terrestrial biosphere. [Answer] One major issue with blood colors in your scenario is that compounds might look very different when in a dilute solution and when in (near) saturated levels. The best example is blood itself. Considering individual "red" blood cells are golden colored, but give a red impression when seen together in tens of thousands. If you dilute blood sufficiently in clear water, you would see that it is indeed golden of color. Another **big** problem is that a lot of metallic compounds have a different color when in *anhydrous* (dry) form and when forming complexes with water. For example, Copper Sulphate is white when anhydrous and blue when combined with water molecules to form complex CuSO4.5H2O. Having said that, here are some of your colors. Tin compounds (+2 and +4 state) are colorless in a solution. Aluminum compounds are also colorless as solute. Same for silver. [Reference for above colors](http://www.chemistrylecturenotes.com/html/colors_of_metal_ions.html) [Platinum compounds](http://www.chm.bris.ac.uk/webprojects2003/freedman/Platinum%20Compounds.htm) are **mostly** brown or red in color. However the oxides (+2 and +4) are black. The *peroxide* of platinum is golden yellow of color. Gold oxide (+3) is reddish brown ([reference](https://en.wikipedia.org/wiki/Gold%28III%29_oxide)). Cobalt oxide (+2) is olive green of color. ([reference](https://en.wikipedia.org/wiki/Cobalt(II)_oxide)) Zinc oxide is white while nickle oxide is green (when pure NiO) or black (when the oxygen to nickle ratio is not constant in the sample). ([reference](https://en.wikipedia.org/wiki/Nickel(II)_oxide)) No metallic oxide that I know of, produces white color when dissolved in water. Metallic complexes might. But metallic complexes vary so immensely in color that it would turn one completely bonkers knowing how many colors a single transition metal ion could have when in a compound form with other metal ions. [Answer] The colour of a complex organic molecule containing a metal atom is by no means completely determined by that metal. For example, chlorophyll is bright green. The metal it contains is magnesium. Solutions of magnesium salts are usually colourless. Or you might consider the gamut of colours that a nasty bruise goes through as it heals. These are all generated by Iron, as your body recycles it from blood and other tissues as the damage heals. Known here on Earth: certain obscure marine worms use Cobalt-based blood. It is (unsurprisingly?) deep blue. Some of the metals you mention are unlikely to be useful as part of an oxygen-transporting biomolecule. Obviously an alien biochemistry might throw up surprises and the metal or the colour might not necessarily be part of the oxygen transport mechanism. However, to be useful on that front you almost certainly need a metal which exhibits two (or more) oxidation states differing by one. You'll find these in the transition metals on your periodic table. Vanadium through Copper on the first row, and many of the corresponding elements on the two rows below. The element will need to be reasonably abundant, since an organism will need a fair amount of Iron or whatever it can use in place of Iron. Here on Earth the heavier elements in the second and third rows are relatively rare (and of course you get less atoms per gram). The only one which life has made essential use of, is Molybdenum. (A few bacteria use Tungsten but that's not widespread). [Answer] And don't forget that there are [white-blooded fish](https://en.wikipedia.org/wiki/Channichthyidae) from Antarctica which don't use metal based oxygen carriers at all (at least in the blood. Some use Myoglobin in the heart muscle). [Answer] All the answers above look interesting and with thought behind them, but ph of the solution can change the color and chemical binding of many complex compounds. The reference to the element (probably a metal) being abundant has some credibility. But plants use magnesium for chlorophyl (the structure is very close to hemoglobin) and it is less abundant than iron. It could always be possible for alien biology to use two or three metals together - one that is very common and one that is not - to make a better oxygen carrier. Or some other combination that we can not think of. An interesting side thought - if a copper compound that dissolves in water is added to sodium carbonate, copper carbonate is formed and comes out of solution, but add amonnia and it redissolves. Think about that and alien blood and colors [Answer] Chromium based blood in a +6 oxidation state could possibly appear orange either when it is oxygenated or deoxygenated depending on when it’s in the +6 oxidation state. ]

[Question] [ As usual I write stuff like any professional fictional writers do, my protagonist worships a deity calling herself "The Expensive One" and she bestowed a flawless full body diamond armor which comes with a sword also made entirely of diamond. In return, my protagonist must purge the land of the poor: anyone with net worth less than my protagonist has to be sacrificed and have their severed digits offered to the goddess as an atonement for their crime. When the king heard about this, he decided to launch a manhunt against the protagonist. Both parties will meet-up at a valley to exchange pointers. My question is would the diamond armor and sword make my protagonist invincible or could he lay waste to the cosplayers and their toys? Assume my protagonist is an Olympic champion with unlimited stamina and doesn't feel hunger or thirst. Please show working to support your answer. [Answer] **No** Ten (or more) knights would grab him by the arms and legs, bind him in iron chains, and then chuck him in a dungeon. No matter what kind of armor or melee weapon you have, you are still limited to the strength of one human; you will be overpowered almost instantly by a group of people. [Answer] There are numerous problems. 1. Diamonds are brittle Hard, but relatively easy to crush, if you happen to hit just right. Armor would be crushed before your hero knows what happened. See [Why does diamond have lower tensile strength than Iron?](https://physics.stackexchange.com/q/102822/104551) on Physics Stack Exchange. 2. Diamonds are flammable Sure, it takes about 900 degrees Celsius to start diamond fire, but then it's just like coal. 3. Diamonds are expensive For a price of one set of such armor, you can have dozens equipped with nets etc, to catch your diamond without damaging it. Guy inside starts to be irrelevant. [Answer] You will be downed with a few nets, fixated with rope and either buried alive, drowned or launched with trebuchet. In short, no, don't try this at home. [Answer] Nope. Diamonds are very *hard* (10 on the [Mohs scale](https://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness)), but this just means that they are very resistant to scratches (which is why they're often used in drill tips for mining). They are very brittle, so they shatter very easily - not a property you want for armour or weapons. If the armour's compromised, the protagonist becomes a lot easier to kill. In addition, diamonds are still pretty valuable. If word gets around that the protagonist carries weapons and armour made of *diamond*, that will motivate quite a few people to join in the hunt - paydays like that don't come along very often! We'll be rich, I tell ya - rich! [Answer] They could shower him in tar and lit him as a torch. Getting fried in your armour is not a nice way to end your career. [Answer] Full-Plate steel armor was already practically impenetrable at the time, and there were still plenty of ways to kill people wearing it. Gaps in the armor are *necessary* for mobility, simply immobilizing the wearer if absent, and the fact is that diamond armor won't reduce the concussive damage at all, so unless you have the world's best padding under that armor, you're still going to feel the blows of various medieval bludgeoning weapons. Better to stick with firearms, which *did* bring about the end of the armored age. [Answer] # No Because of the same reason an indestructible car will still crush you to a pulp in a high-speed crash. The human body is not very good at accelerating/decelerating quickly, or absorbing impact. If the Knights decide to repeatedly stampede you with cavalry, you will die. If they decide to dance around you while attacking you with maces, you will still die. The diamond armor may not even suffer a scratch, but it won't absorb the impact for you either. If they decide to rope you with steel chains, you can't do much either. Even with a diamond sword, it takes a lot of time and effort to sever a steel chain. And I don't think the sword will do much good if you are being dragged behind a galloping horse. All they have to do is drag you to a cliff and throw you off. You will die a glorious death in a diamond armor! Not to mention that hardness and strength are very different properties, as [Philip Rowlands](http://Philip%20Rowlands) points out in [his answer](https://worldbuilding.stackexchange.com/a/54331/195). [Answer] Diamonds are hard, but due to the way the atoms are laid out, they have several cleavage planes. So while it won't scratch easily, you can fracture or shatter it. From *The Diamond cut* by Edward J Epstein (<http://www.edwardjayepstein.com/diamond/chap11.htm>) "Until the late fifteenth century, diamond cutting had been a primitive business. Diamonds were first "cleaved" by placing a chisel at the stone's weakest point of molecular cohesion and striking it with a mallet. If the precise point was located on the diamond's structure, the adhesion would be so weak that the diamond could be separated with a fingernail. If pressure was applied to the wrong point, or in the wrong direction, the diamond would shatter. " So whacking on it with swords or maces isn't going to do it much good. [Answer] **Diamonds are hard, but they're brittle**. Diamond armor would be very hard to scratch, yes, but [even a humble gemcutter](http://science.howstuffworks.com/environmental/earth/geology/diamond3.htm) knows how to get around that. The sword is especially problematic: it would probably break the first time it hit something made of metal or stone (someone else's armor or sword, perhaps). There are a couple of tactics I can think of to handle something like this: 1. **Smash the armor**. A couple of knights with warhammers should make short work of a suit of diamond plate. Even an archer could do it, though they'd need an *extremely* lucky shot. 2. **Tackle the knight**. A good set of full plate can protect you from swords or even arrows, but no amount of armor will do you any good against a linebacker. Diamond armor would be lighter than steel for the same thickness, so you'd have somewhat better mobility than a knight in conventional armor, and that might let you dodge the first few attempts, but by sheer numbers someone would get you. Once you're immobilized, the fight is over: you may still be alive, but you've lost. 3. **Kill it with fire**. Diamond conducts heat very well: better, in fact, than most metals. This is not an advantage against a blob of burning pitch or boiling oil. Other answers have talked about diamond's flammability, but really, the protagonist would be dead long before the armor caught fire. [Answer] Assuming that your diamond war-kit behaves like modern science would suggest it behaves, this clearly won't work. But, this is clearly also a fantasy story, where the protagonist is given magic diamond armor by the gods. If you want them to win, go for it. The Greek heroes have done far more with far less. What I'm really concerned about is the background to this question. Your protagonist was given magic, probably priceless magical armor by a god, and told to kill anyone with less net worth. Given how much magical, invulnerability granting armor is worth, I think you've just made a character who is magically bound to kill the entire world, barring anyone who gets magical equipment from their god. I don't want to tell you how to write your character, I just think you may be asking the wrong question. Whether he wins or loses is kinda up to you (he's wearing magic armor, he can live or die however you want him to), but I think what's more interesting is how he's going to deal with being ordered to kill Everyone. [Answer] **Well... not as such. But...** There are a few things about this scenario that jump out at me. ***In the real world*, suiting up in diamond armor would be a stupid idea.** As pointed out by the numerous other commentators, diamond, while very *hard*, is not exactly *durable*; mundane diamond armor would shatter easily, making it quite probably worse than useless. **However**... we are talking about something granted to your protagonist by a god here; you could easily set it up as, say, magically forged, perhaps giving it properties similar to 'mithril' from The Lord of The Rings, for example. I admit that personally, if this really is a god of wealth, I'd be more inclined to imagine something like a pure platinum armor set encrusted with precious gems (platinum is probably not great armor material either, but the *real* armor in this scenario is the god's magic, not the mundane matter it swims through.) I haven't checked out which of these options (diamond vs. platinum) would be more valuable in our world, I admit -- *but* value isn't something intrinsic to the valuable thing; it only ever exists in the context of a society, a culture, an economy. Diamonds are expensive because they're rare, and because enough human beings place a sufficiently high value on them to drive up the demand (partly also because they're rare and, of course, shiny) -- not because they are diamond. In your world, maybe the economy works differently than our modern one (though I'll take it as a given that gems, precious metals, etc., are still valuable.) Which segues nicely into another point... **As a god of wealthy people, it would be incredibly counter-productive to try and kill off the poor.** Why? Well, without the lower classes to take care of the "mundane" work for them, the rich would be forced into manual labor themselves. If you know something about history, you'll know that before mechanization -- before the invention of such marvels of technological cleverness and infrastructure as the washing machine and industrial-scale farming -- *everything* that needed to be done had to be done by hand. The only reason the rich and well-off can *be* rich and well-off, as we commonly understand it, is that there are whole strata of people below them doing things like the manual labor of farming (without which there would be nothing to eat) and building (without which there would be no shelter), weaving, tailoring, cooking, mucking out stables... the list goes on. As a god who wants to preserve and increase wealth in such a world, I'd probably be more interested in suppressing rebellion and making sure the lower classes don't get any ideas in their heads, speaking for myself. *That doesn't mean that The Expensive One won't do what the premise states!* It just means that I think their/her/its motivations are probably rather different than it might seem at first glance: systematically savaging the poor and working people will create a great deal of economic instability and (if you can keep it up) might quite conceivably cause the society to collapse. **Getting back to the point of this question, finally...** I don't think that simple armor (whether mundane/relatively ineffective/impossible diamond or something that's effectively mithril) and a weapon will *guarantee* you victory over the King's forces all by themselves. Even without supernatural aid of their own (they have the whole resources of the kingdom, which may quite possibly include mages or the priests of other gods) they probably could, if you tried to take them on head-to-head, eventually trap you (with, say, weighted nets), chain you somehow or other and seal you in a deep crypt to live out the rest of your lifespan in darkness (see: 'doesn't feel hunger or thirst.') They have numerical superiority, after all, and taking them on in an open area where you can be surrounded ... might not be the best idea, especially if all you have is relatively mundane weapons, armor, and superhuman durability. **But that doesn't necessarily mean all is lost:** As a canny protagonist who wants to keep causing economic chaos, pleasing her god or maybe just sacrificing the fingers of the unfortunate, I feel like I'd try a few other approaches... First off, I'd probably try to **evade the army** or lure them into a trap of some sort: perhaps draw them into a narrow, twisting canyon or even a tunnel system where I can attack from the shadows and pick them off one by one, or at least two or three at a time. One big advantage shows up here: they'll get tired, scared, thirsty, and so on, and I won't. If this wasn't feasible, I might want to become a sniper: find good vantage points from above the enemy force and fire down onto them, preferrably causing as much chaos as possible with each shot and moving off quickly to avoid being targeted in return -- improvised explosives, fire, or maybe even some kind of cursed payload would probably be good ideas here. Finally, assuming I've done a good job slaying and sacrificing peasants and such in the past, I could always pray for assistance from the god I follow. I have no idea what The Expensive One would be able to or willing to do, of course -- if it would even do anything... [Answer] **No.** The armor has a critical weakness - the arrogant protagonist inside, who can easily be brought down by his own hubris. No battalion needed, just one poor person who has access to a shovel and a blanket. Instructions for the poor person: Step 1 - Dig a pit, optionally fill it with water, cover it with a blanket, and put a thin layer of dirt, mulch, leaves, twigs on top to disguise it. Step 2 - Stand on the other side of pit from Sir Snob and get his attention so that he charges toward you with his sword, falling into the pit. Step 3 - Profit. After he drowns, or dies of dehydration (which he didn't even know would happen because he couldn't sense thirst), recover the diamond armor and sell it. Now you're a rich person and can more than afford to replace your blanket. [Answer] Being inside diamond armor when something like this happens is going to hurt. And the diamond, if it shatters will become very sharp shards cuting into you. <https://www.youtube.com/watch?v=30lGrarz3MQ> There are very few things that can not be turned against someone with a little thought. [Answer] Well, there are plenty of other answers that explain why your notion of diamond armour and weaponry is flawed. However, there is one way to use a full suite of diamond armour to kill a lot of people - sell the armour, and hire a lot of assassins (or common thugs, really...) Ignoring the physics involved, don't forget how many stories have been written about how ridiculous the whole concept of an invincible warrior is. There's all those fun solutions like "crush him in his armour," "bind him in chains," "throw him into the sea" and many, many others. Unless that suit of diamond armour is also a self-contained power-armour that can amplify the wearers strength without limit, it's rather worthless as armour - physical or not. I wouldn't worry about looters too much. "Full suit of diamond armour" sounds like the kind of thing no one would ever believe even if they were seeing it with their own eyes :D [Answer] Diamonds, while hard, are very brittle. One really sturdy hit with a warhammer would probably leave your hero unarmored, even if each piece was a single crystal. [Answer] **Basically, No.** Despite the strength of diamond as a material, a correct strike will split it straight. Also, due to Diamond's tetrahedron structure, it will basically 'not like' its sword shape. Also, sharpening it would be a nightmare, considering how strong it is. The thing that gives a sword its advantage is sharpness, not its strength as much. Iron is easily sharpened, perfect for swords. Also consider how brittle diamond is. Diamond is a non metal, meaning it is easily shattered/snapped. As for the armour, it would be crazily heavy. Chainmail is used because it is light, and in conditions were iron is used, they are sheets to decrease weight. Diamond cannot be a sheet as it is brittle and a small smack will snap it or shatter it. In conclusion, your best bet is to sell it, get a hoard of money and buy an army. Or hang them on your wall. [Answer] Definitely a huge NO. Diamonds are HARD - that is does not exchange with Tensile strength - so you have expensive (and shiny) scratch-resistant armor but crushing/bludgeoning can and will break it - so mauls/battleaxes/clubs/dudes with rocks beating on him with destroy the armor. You figure all the joints will be exposed, so a spear or arrow to your armpits, knees, neck, eyes - still meat inside that armor Nets, pitfalls, legbreakers, snares, and other less-than-traditional trapping methods will be fine - fight smarter, not harder, I'd tag and bag the protagonist and buy some wenches with his diamond cuirass - thanks for the loot, bro! Diamonds are still carbon, it will burn, some a nice defilade position filled with pitch can take care of him. [Answer] Consider how efficient simple burning is. Diamonds are carbon, and they burn easy like coal. It shouldn't be too difficult to get some liquid splashed onto the armor, and set it to flame - splash lots of oil and shoot flaming arrows. [Answer] Here's my thought: If a goddess, mind you a Goddess, has granted you a full body diamond armor, would she, a god, not know the weakness of a diamond armor and sword. The armor is flawless, meaning it has no flaws. The diamond would have be a complete seamless diamond, with no points to crack and shatter. The armor may be full diamond, but did it say how it was full diamond? How do you know if the goddess has put some super shock resistant substance beneath all that diamond? And about the weight, heavier things make you use more strength to move them, thus making you tired quicker. But this guy, this guy has unlimited stamina! He can move in the armor forever if he wants to! And he was an Olympic champion. He could have been any Olympic champion, wrestling, weightlifting, acrobatics, swimming, ANYTHING! There are many of the martial arts that he could have been an expert on. The sword, too, must have been made flawless, right? Meaning that it could take a whole lot more to break it. In the end, the hero himself doesn't do the attacks, time does. Since he has unlimited stamina, doesn't feel hunger and thirst, he could play defensively. He can just keep dodging and block enemy attacks again and again and again. The enemy however, after 3 days and nights of battling a monster like the hero, would be tired and hungry. They would either give up or die of over exhaustion. Anyway, you people have too less faith in the almighty "Expensive One". [Answer] **No.** Let me put this in another perspective that most people have heard: *It will be like bringing a very expensive and fancy knife to a gun fight.* You will be shot. You will probably die. Your cool knife will be sold on eBay. In your scenario, the opposing army would notice your valuable armor and team up on you -- overpowering you. The diamonds will be split up and sold to the highest bidder. [Answer] Even worse, and something the other answers didn't mention, is that it's impossible to shape diamond into the items you're looking for. The crystal lattice simply won't allow for it. So the suit of armour AND the weapon are theoretical impossibilities, at least if you make the assumption they're each made out of a single crystal. If they're made of many crystals, bonded together in some way, things get worse as now you have a multitude of bonds between crystals that are weak spots in your armour and failure points in your weapon quite apart from the brittleness of the diamond itself. And then there are the required joints between the armour pieces, the gaps between them, that allow the wearer to actually move in the armour. Medieval fighting techniques for dealing with people wearing plate armour (which this would be a ludicrous variant on) often included ways to dislodge armour plates by driving items under them and prying them loose, or sticking a something pointy in between plates to cause wounds under them. Both techniques would work with a suit of armour made out of diamond as well. Of course in a fantasy universe maybe something else is meant by the term "diamond", maybe some white semi-translucent metallic compound that is extremely hard and expensive. In that case it might be forged into swords and armour plating in a more normal fashion (rather than gluing bits together) but you'd still have the gaps between the plates that can be used to cause wounds or get plates off and then wound the wearer. [Answer] In short, No. Diamonds are much heavier than iron so they (even if they were Olympic champions) would be at a disadvantage. Diamonds can also be broken by an iron sword as it scratches. Constant scratches would wear it away to being useless. I use another example (<https://en.wikipedia.org/wiki/Diamond#Hardness>) and they were looking at whether diamond could be used as a bulletproof material. They compared it to kevlar. While good at pistol bullets kevlar is useless against rifles. Theoretically, If you could deal with the weight it would be indestructible but the atomic structure means is would shatter after two shots. To conclude, You could have the character use it in a final fight scene but it can only take a few hits. In reality a couple of sword strikes or a signal hard hammer hit would destroy it you could make it have a few hits. Potentially have a climax in the final fight where it breaks and they have to fight without it? -Joshua [Answer] 1)Diamond is very hard but can also shatter from a direct therefore a bad move to wear it as protection. 2) Never wear full diamond battledress in direct sunlight as heat transference and magnification will cause rapid resemblance to an over done burger 3) Killing off all peasants will make getting cheap labour to work the fields, do the housework, make profit for their betters and tug a forelock nigh on impossible. Point 3 is the vital flaw in this protagonist and all right minded capitalist/overlords/kings/Knights and general ascendant strivers will move heaven and earth to kill her off asap Moriarty [Answer] Diamonds are vulnerable to fire and to smashing action, so the diamond armor is mighty only through its lightness and opponents blinding capabilities. Moreover, if the hero does not have access to flying/levitation capabilities and is not able to have incredible acceleration for 10 seconds skill and enhanced situational awareness skill, he might still be put in some kind of tangle net and put in a cage or dungeon where he can perish because of hunger. [Answer] As pointed out here: <https://www.youtube.com/watch?v=8KuH0-994Hk> Diamond Armor would shatter too easily, be way too heavy, and would give your protagonist has a higher net worth than anyone on the planet. EDIT Problems with diamond * Diamond is hard, but brittle, hit it with a hammer in the right way and it will shatter. * Diamond is not malleable, so forming plates out of it would be difficult * Diamond is expensive (though that is mainly due to diamond companies telling people diamonds are expensive) Diamond varies greatly in price per carat depending on cut, color, and clarity. Either way though, google unit calculations says that one pound is well over 2000 carats, so even at 1000 dollars per carat (note: as far as I can tell low quality diamonds start at 1000) that would total to over 2,000,000 per pound. A typical suit of armor weighs somewhere around 50 pounds, so that's a 100,000,000 dollar suit of armor, just from the materials. Note that this price is for armor made from cloudy, colorless, diamonds, if you want the armor to be sparkly or of a specific color then it would potentially cost much more. [Answer] First, why does the "Expensive One" want her champion to kill those poorer than he is? Doesn't make any sense, as many others pointed out. However, there is a potential explanation: *NOTHING is of more worth than souls!* The goddess is simply too distant from human society to realize there are better ways to obtain souls, and if the champion explains the issues here, she will likely change his mission to getting her the souls of an ENTIRE KINGDOM! (Champion, go big or go home!) However, the champion still gets the "diamond" armor and sword. Why? Because *magic,* that's why. The diamonds are actually shards of the goddess's divine energies, which fit together seamlessly to make impressive armor: 1. The angles of the crystals are set in such a way that they take advantage of natural magic currents that form around the armor, deflecting most attacks. 2. Each "diamond" is made out of multiple triangle-shaped Ether formations, and since the triangle is supposedly the strongest shape in existence, the unique combination of these many triangles makes the armor nigh invincible. A reversed version of this effect makes the sword more powerful by channeling magical currents in such a way as to speed up and strengthen his strikes. 3. The diamonds represent the worth of the goddess's worshippers to her, conveying what she values about them (charisma for a preacher, wealth, zealousness, and devotion for everyone else) to the champion, *including* what she values about the champion (physical fitness, reliability, and so on). This makes him superhuman. 4. The light that enters and is reflected from the depths of the "diamonds" conveys the bright (positive) side of the champion and the goddess he serves. This means that to almost everyone (excluding mages with powerful enough defenses, or those who have never seen him), this man can do no wrong. He's all that and a bag of chips, a paragon of excellence, an example to our nation, etc cetera. The same goes for the goddess, who wants everyone to become their best selves. Wealth just *happens* to be part of that, and who doesn't want wealth? The genius of this is that once the king and his party shows up, 4 will allow the Champion to pretty easily secure the princess's hand in marriage. "But then there goes my plot," you might say. Ah, but then you can use these plot pointers: 1. The tension that results from the champion taking advantage of 4, testing the boundaries or wearing down the enchantment through his self-centered (and decadent) behavior 2. The goddess having a crisis of self as she begins considering the worth of character over material wealth (ie. spiritual over fiscal prosperity) and changing her entire way of thinking/life 3. The champion shows up to report to the goddess (or the goddess checks in on him) and 4 backfires on the goddess by making her fall in love with him. I feel this would be a *great* plot twist if used correctly. Hope this helps! ]

[Question] [ Even though [text-based terminals still see specialty use cases](https://ux.stackexchange.com/q/101990/7062), modern general-purpose computers generally run graphical software and have a graphical user interface (GUI). This includes everything from low-end cell phones and some computer peripherals like printers, to fairly high-end servers. I'd like for computers to be roughly on par technically with what we have today, but with user interfaces that are predominantly text-based. It's okay if these computers work with text blocks and things like that (for example, like how [the IBM 5250 series](https://www.youtube.com/watch?v=tn9xz1SpuyE) of [terminals](https://retrocomputing.stackexchange.com/q/1789/357) worked), but except for graphically oriented work such as image editing, there should be minimal graphics. Given that in our world, personal computers started becoming graphical pretty much as soon as they were powerful enough to run a graphical user interface at acceptable speeds, and some [even earlier](http://toastytech.com/guis/alto3.html), **how can I reasonably explain that GUIs never became mainstream?** **Note that these computers *need not be expert-only* systems;** I just want their interfaces to be predominantly text-based rather than predominantly graphical as is the case today in our world. Also, to clarify, since there seems to be widespread confusion about this: **Lack of a graphical *user interface* does not imply a lack of *graphical capability.*** Take the original IBM PC model 5150 as an example; with the exception of those equipped only with a MDA graphics card, the software running on those often used text-based data entry with graphical visualization modes (what we in modern terms might call more or less accurate "print preview"). For example, something similar to [the early versions of Microsoft Word for DOS](http://toastytech.com/guis/word115.html) or how [early versions of Lotus 1-2-3 used different graphics cards and monitors to display data and graphs](https://en.wikipedia.org/wiki/Lotus_1-2-3#Beginnings). Instead of thinking "no graphics at all", think "graphics only as add-ons to text, rather than as a primary user interaction element". And since lots of answers imply that the only alternatives are pure command-line based interfaces and GUIs, let me remind you of tools like [Norton Commander](https://en.wikipedia.org/wiki/Norton_Commander). I used Norton Commander back in the late 1980s and early 1990s, and still use look-alikes such as [Midnight Commander](https://en.wikipedia.org/wiki/Midnight_Commander) to this day, and can guarantee that those can provide a perfectly useful environment for file management and launching applications that do not in any way depend on more than a text console. There is even a general term for these; [Text-based User Interface, or TUI](https://en.wikipedia.org/wiki/Text-based_user_interface). [Answer] As almost anyone who ever used shell would say, a text based UI is much more comfortable, fast, easy to develop and just BETTER. The big problem, though, is that it's a language you have to know prior to doing anything with your computer. This is the main advantage of a GUI. So I think what you should consider is a way to explain why computers can always presume that the users "speak their language". I see a few options: * Computers started out as a very elitist technology, and knowing the language is a kind of status symbol. This would give people the motivation to learn, and developers the motivation not to appeal to less-sophisticated audiences, because that would ruin their brand. soon, the language is just common knowledge. * The language in the world is in the first place very accurate and structured. There is always exactly one way to say everything. (I think this could be very interesting to develop, but also quite hard) * The language of the computers either developed very fast or co-evolved with the human understanding of it, i.e. the computers would "learn" a new word, this would be made famous and everyone would know this new word. [Answer] One simple change: **Never invent a [Computer Mouse](http://www.computinghistory.org.uk/det/613/the-history-of-the-computer-mouse/)** No matter how comforting a graphical user interface (GUI) is, it wouldn't be nearly as comfortable and useful without the invention of the computer mouse (and later touch interfaces). While text interfaces stem from times and are still designed for use with only/primarily keyboards, you cannot comfortably nor reliably make use of any GUI without having a mouse or any other 'pointer' available to *select* things and *interact* with them. The invention of the computer mouse and thus *the pointer* brought with it the era of *pointy-clicky*, a derogative term referring to virtual buttons and interactable areas that are fully virtual as opposed to the hardware reality of a keyboard. Now instead of having to work with a limited set of input functionality the only limit the amount of pixels a display can show (if you abuse *scrolling* not even the screen-size will be a hindrance for your mad interface experiments). The combination of mouse/touch and GUI allows to cut away a layer of indirection that will always be around when you have to type in something and confirm your command before anything can happen. Even though you could react to every keystroke directly, there will be a finite set of interactions per program state, while there's a potential unlimited set of interactions that can be made with mouse/touch. --- *Elaboration on the evolution of your interfaces*: Now even if you do only have an indirect way of interaction, GUIs will eventually emerge. Although your GUIs will be massively different from the GUIs we are used to (and have come to ~~hate~~ love). The eventual GUIs will be more of a graphically enhanced text interface (GETI) and the graphics will be used to display things such as video, images, make some nice backgrounds or gradients, etc. the classic prompt will be unlikely to disappear. Eventually it is also likely that voice-input becomes more common. Voice-input will simply be an addition and pseudo-replacement for the keyboard but cannot fully replace it unless voice-processors become way better than they are in our timeline or your software becomes more lenient and outfitted with pseudo-intelligence that can guess what you're intending to do and assist/clarify by asking you additional input when needed. [Answer] Slightly alternative answer. You could have had a major breakthrough in **voice recognition** in the early days of the computer. The effect of this could be that interfacing would evolve around using voice and ear, as opposed to eyes and hands. The added benefit of this is that you can continue using your hands and eyes to perform certain tasks (e.g. you're fixing a car and asking the computer for help in the mean time). (This in turn means that no effort is put into developing GUI's for computers, but debugging/configuring might be done using a CLI) [Answer] The affirmation that "modern general-purpose computers generally run graphical software and have a graphical user interface (GUI)" is simply false. The vast majority of servers have no GUI; see "[headless server](http://whatis.techtarget.com/definition/headless-server)". They live in rows upon rows of racks and can be accessed only over the network. The computers behind search engines, on-line storage services, web-based mail services, enterprise resource planning software, questions and answers boards such as this one, content management systems, the computers providing file, print and streaming services, and in general the computers which serve the interconnected documents forming the world-wide web do not have graphical user interfaces (with, of course, the rare exceptions expected from everything in IT). A better formulation would be "*workstations* (and gamestations) generally have GUIs"; workstations have generally had GUIs for a very long time. The windowing system in current Linux distribution is based on the X11R6 protocol, first released in *1994*. The first major class of mass-marketed applications which used full-screen graphics were games. Games ran in full screen graphical mode on the *ZX Spectrum*. The first GUI-based "killer applications" were desktop publishing and pre-press work. The major problem I see with character-cell interfaces everywhere is multi-language support. A computer which can show very many thousands of different characters on a character-cell display can also show graphics on the same display -- a computer which can show 中华人民共和国 can certainly display graphics. And since it can display graphics, it *will* display graphics: some young student at a university somewhere will write a graphical interface and game over. Unless... The only way to preserve character-cell interfaces for the masses is to make them compulsory; suppose that the domination of the computer industry by a big blue three-letter corporation had not been met with anti-trust challenges from the government of the greatest power in the world. Suppose that on the contrary that domination would have been *enforced* by the powers that be; no such thing as open-source operating systems like UNIX, no such thing as simple-minded operating systems like MS-DOS and the classic Mac OS; all computers run safe, secure and reliable operating systems like OS/360. Wouldn't we all be happy with the character-cell variant of the [Common User Architecture](https://en.wikipedia.org/wiki/IBM_Common_User_Access)? [Answer] I think that GUI are so popular because visual learners consists the majority of population. With 2 of every 3 people being visual learners they consist the largest market, same as most things are made for right handed people. If you make Auditory learners the majority of the population, fallowed by kinesthetic with visual learners distant third, the market will adapt and the GUIs will be expensive niche market. [](https://i.stack.imgur.com/Gk2jS.gif) I'm a programmer and I don't like text UI. I know very well how powerfull they are, I learned to be quite good with bash, and use it every day at work to administer our UNIX servers, but if I had choice I would allways choose GUIs. That's how my brain is wired. I learned to use Emacs but I always go for Atom & Visual Studio. P.S. Image taken from [Successfully Using Visual Aids in Your Presentation](http://www.uab.edu/uasomume/fd2/visuals/page1.htm) [Answer] **Your world does not have pixel-capable screens.** With the components readily available, one could be built only crudely, at impractically large sizes (billboard size or greater), and with large gaps in between the dots. But no hardware or software ([ray-tracing](https://en.wikipedia.org/wiki/Ray_tracing_(graphics)), etc) was ever developed that would make good use of this, and no one except maybe sci-fi authors really sees much value in such a thing. If all you have to make desktop monitors out of is arrays of [seven segment displays](https://en.wikipedia.org/wiki/Seven-segment_display), then you have a text-based user experience built into the hardware. If the monitors are literally made out of 7-segment displays (or something like them), and particularly if you bring in a historical/legal basis for that, then you don't really need any tortured argument about why they don't just *draw pictures* on the things, because the capability isn't there. You can also offer some other side benefits of this that are off-limits to us in the real world. Like having the monitor be just another cheap USB device, or Bluetooth device, with virtually zero power consumption. And you can bring back [ASCII art](https://en.wikipedia.org/wiki/ASCII_art) in a big way. This conception of technology requires a divergence of technological development from the real world somewhere around 1900. [Radio](https://en.wikipedia.org/wiki/Golden_age_of_radio) is in, television is out. Comic books, [dime novels](https://en.wikipedia.org/wiki/Dime_novel) and [penny dreadfuls](https://en.wikipedia.org/wiki/Penny_dreadful) are in, cinema is out. Old-fashioned [seismometers](https://en.wikipedia.org/wiki/Seismometer) and other machines that directly draw on paper are in. The advent of computers still happens, because this was done for reasons of [code-breaking](https://en.wikipedia.org/wiki/Cryptanalysis_of_the_Enigma#British_bombe) and mathematical research ([Babbage](https://en.wikipedia.org/wiki/Analytical_Engine), [Zuse](https://en.wikipedia.org/wiki/Konrad_Zuse), others). [Blinkenlights](https://en.wikipedia.org/wiki/Blinkenlights) are in. Cheap and accessible photography is out; most people can only afford one or two family portraits in their lifetimes, and it's all film based. But for the price, the quality standards are very high, and portraits are typically [stereographic](https://en.wikipedia.org/wiki/Stereoscopy) (gives more flavor for divergent technological *progress*). Printers are very fancy, very cheap (and the ink is even cheaper!!), and very fast, with advanced typography capabilities, and paper is [incredibly cheap and easily recycled](http://blog.syracuse.com/future-news/2009/10/future_newspapers_babylon_5.html). Even sophisticated book binding is a standard feature on a very affordable printer. If you need a "nuclear option", further reinforce suspension of disbelief with copyright law. In your world, equipment manufacturers would be held liable for any device *capable* of showing a photograph or facsimile of a copyrighted oil painting. (If you go in this direction, have ["the Betamax case"](https://en.wikipedia.org/wiki/Sony_Corp._of_America_v._Universal_City_Studios,_Inc.) occur 100 years earlier, applied to single-frame film photography, and decided more or less in the opposite from real history. The real case was a 5-4 split decision!) Strictly control photography licenses on this basis, further accounting for the high price and therefore rarity and superior, exalted quality of photographs. For all these reasons, no one has much motivation to develop technology capable of showing pictures, and the work it would take to match the analog capabilities with any digital graphical system would be far too high for amateurs to mount a successful attempt. Even serious efforts with serious budget would be perceived as crude toy projects, or worse, as illicit subterfuge, without any legitimate practical use. All these background factors will hopefully reinforce the divergence away from pixel graphics and create a huge barrier to introducing it into your world. ("Such a monitor would require way too much power!" "Stereoscopy would be next to impossible!" "You would have to upset 100+ years of copyright law and legal precedent!" "Even simple line art would look like garbage!") > > "There's way too much information to decode the Matrix. You get used to it, though. Your brain does the translating. I don't even see the code. All I see is blonde, brunette, redhead. Hey uh, you want a drink?" > > > [Answer] **Make porn and video games not a thing.** Now who cares to make computers handle more graphics? Good luck on getting people to believe it. **Make mobile computers useful/desirable earlier.** If we had hand held computers that could do something useful or cool before anyone had gotten graphics running, or when graphics would have been battery prohibitive, text only could have become the standard way everyone uses computers. **Make programming much more popular** If most people write at least some of the programs they use and text is the (easiest) way to interact with them text will be popular. This could happen if copyright got out of control or people lost trust in distributed programs. **Make illiteracy or functional illiteracy a bigger issue.** You don't want to look like the only guy at the meeting who needs pictures, and you really don't want to imply you boss can't read. [Answer] I'm surprised so few people have touched on the possible cultural motivators that would limit/prevent the development of GUIs. My first thought was (no pun intended), "iconoclasm". In a world where iconoclastic religion holds sway, people will *believe* that GUIs are evil and/or degenerate. Words are important; unnecessary representation of *things* are an affront to God. @Dotan Reis's idea regarding *elitism* has real potential too. If the early computer users were both rich AND smart, then a personality cult of computer-elitism would lead people to only ever *want* to use text-based interfaces. [Answer] * Stop the push to put a computer on every desk; TUIs can be used by experts, but GUIs were all but required to make the jump from "specialist equipment" to "general use equipment." * Never see a capitalist-driven push to create a consumer workstation market (TUIs work for trained professionals, and don't demand a GUI) * Increase the culture of elitism towards computers; it has forever been a trend (although diminishing as time goes on) with computer/IT people to prefer more difficult means to prove oneself; many IT guys today "prefer" Linux, but can't provide a non-cardboard-cutout argument as to *why*. Command Line/Terminal being the same deal. * Hamstring the display market. Keep monitors primitive, mono-colored. * Introduce a terrible executed marketing ploy for GUIs; turn the consumers and market off the idea * Have major OS creators/communities view GUIs as inefficient and ineffective. More elitism. ...Basically kill the capitalist market drive, and introduce bad press and elitism to run GUIs away. [Answer] Search, don't sort. Google Desktop made redundant 90% of the Windows GUI in 2004. Apple implemented similar features in Vanilla OSX at a similar time. No more clicking through sub folders trying to remember where you stored something. Simply remember some fact about it: Words in the title, words in the content, last modified date. Enter some of those parameters as a search, and the file appears instantly. In terms of what you could do to move from "we don't use GUIs much" to "we don't use GUIs", either improve A.I. search capabilities, or send Microsoft bankrupt. With MS out of the way, your computer's GUI would look like the Google home page. Blank white space, a single text box for input. At that point, it's not really a GUI any more. [Answer] An important thing to consider here is that once you've gotten past the steeper learning curve, working with text-based input is frequently much *easier* than using a GUI. An example: Suppose I have a directory containing a few thousand files, scattered across various subdirectories. I want to sort them out into separate directories based on various criteria. Let's say I want to move all the files starting with "foo-" and ending in ".log" that were created in the last day. In a GUI, the most efficient way I can do that is probably to sort the files by file extension, then go into each subdirectory, find the block of files starting in "foo-" and ending in ".log", then right click on each individually, open up properties, check the modified date, then drag it into the new directory if it was modified in the last day. Then I move to the next file and do the same thing. And hope I don't make any mistakes while manually doing this a few hundred times. And in practice, if all I have is a GUI, I'm just not going to reorganize those files because there's no way I'm going through all that. With a command line, I type `find ! -type d -name 'foo-*.log' -mtime -1 -exec mv '{}' 'other_directory/{}' +` and I'm done in 5 seconds. And in practice, it takes about 5 minutes because I don't use the `-mtime` argument that often and I need to look it up in the manual real quick (which consists of typing `man find`, then `/modified` to find the right section). For most tasks, the difference isn't *quite* that extreme, but the command line is almost always the more powerful option. The command line version certainly *looks* more complicated (and to be fair, it is), but once I learn it, I can get things done so much faster than I could otherwise. Aside from my web browser, the only reason I use a GUI at work is so I can keep multiple terminals on the screen at the same time. Unless the task is specifically graphical in nature, a GUI just feels like a toy to me. Now consider your requirement that the systems not be "Expert-only". I won't deny that right now, proficiency with the command line is generally expert-only, but think about average difference in computer literacy between a 14 year old and a 74 year old. The adult has had just as much time to learn the skills, and yet they struggle with it. But the kid grew up with this stuff and finds that it comes naturally. If you create a society in which most people learn how to use a command line as an "Experts-only" skill, then in a generation or two, it'll just be another trivial skill that everyone learned as a kid. Edit: A couple people have mentioned GUIs that *can* filter files according to modification date, so here's a slightly more complicated example. This will sort all .log files into directories of the form 'logs/2017-05-20/' based on their modification time, creating the directories as needed. ``` find ! -type d -name '*.log' -exec bash -c \ "export DIR=\$(date +logs/%F -d\$(stat -c @%Y '{}')); mkdir -p \$DIR; mv '{}' \$DIR/\$(basename '{}')" \; ``` [Answer] Just a little suggestion: You might also want the data entry keyboard to be totally different. The guy who is most responsible for the GUIs and mouse we used today, Douglas Engelbart, had originally developed a chord based input system where instead of having buttons for every letter the user had a single handed keyboard that used combinations to create letter - like chords on a guitar. It's worth looking into. [Answer] Well, you kind of kill it when you say that Norton Commander, Emacs, vi and friends don't count as GUI. At that point, there's hardly anything left that *does* count as GUI, perhaps just the visual fluff you get from high-resolution (e.g. more than 80x25 and such) displays. So, let's assume that's exactly what you mean. No fluff. Why *do* we get so much fluff? When it first comes, it has a certain novelty aspect. But that wears of rather quickly, and is actually quite discouraging to many users. Just look at all those examples like rounded corners, gloss, transparent windows and similar - you show them off for a generation or two, just to flex your muscles in front of a crowd of fawning fanboys, they get copied all over and used in all the wrong applications, and then the novelty wears off, and the fashion changes. Look at Windows 10 compared to Vista (all that gloss and transparency!), XP (rounded *everything*!). Windows 9/10 design is simple, clean, unobtrusive; a nice show of what remains when you get rid of the fluff. So why do the graphics remain, rather than going back to text interfaces? The answer is actually quite simple - it makes a lot of complicated problems easier. Mind you, I'm not saying it's a panacea. It isn't. Text interfaces still have plenty of benefits: * Friendlier for remote terminals * Easier human auditing, with easy logging of everything that happens at the terminal * Easier showing of history in general * Easier composition of text-only applications (though this fades when any sort of "GUI" enters the equation, even in text-mode) Now, of course, graphics had a head-start in applications that were, well, graphical. Computer-aided design. Publishing. It's not really a long list. Even today, some people can't stomach using a graphical interface for things as complicated as DTP - at best, they have a graphical window into what the layout is going to look like on paper (or what have you), while they do the actual editing in something like TeX, or even MarkDown or (gasp!) HTML. Why did graphics win on the desktop in general? As noted before, text-mode applications still had great "GUIs", you still had full-blown integrated environments with all the cool things true GUIs give you, like keyboard shortcuts, menus, mouse control, hinting, all the nice discoverability. Exactly because of those advanced users that everyone here is calling to the rescue. Why? Because *there was no compatibility **anywhere***. Everyone did text-based applications their way. Even attempts at standardisation like POSIX, or even MS-DOS (which was designed to be quite a bit different than it actually turned out, mostly for - guess what - compatibility with IBM DOS, which got released slightly earlier) mostly failed. Even at the IBM PC (and its clones), where Microsoft quickly gained dominance, every application had its own idea about what commands should be named, what actions should do what, how to format their input and output data. Nobody tried to make common interfaces, formats. There was just endless arguments about who was better. There was no end in sight. And then Xerox came with their revolutionary PARC. Now, mind you, this was tons of things that were utterly impractical when the research teams actually designed them. There were no computers powerful enough to run their systems, while also being anything close to affordable by any family, or really even corporations. But computers got powerful quickly, and *everyone* went to the well. Atari, Amiga, Apple, Microsoft - everyone adopted the same basic paradigms. Everyone also added some of their own, but those were also quickly spread in the new world - a world of inter-operation and compatibility. In no small part because the ones who cared about compatibility started winning. MS-DOS wasn't the best OS, not by far. Unless you cared about the fact that it *run pretty much everything*. You could take your applications from Dr-DOS, IBM DOS, and a few dozen other Something-DOSes and OSes, and run them on MS-DOS. Which OS do you buy? The one that has you locked-in to a couple of software packages, or the one that gives you pretty much *all* of them? Which OS do you design software *for*? Windows weren't the first graphical OS, but that didn't matter anymore. The drive for compatibility was already there, and in full blow. Use a mouse to point at a button, press the mouse button, action happens. Every application on every system behaved the same. You had windows, you had buttons, you had scrollbars and menus - and there was a lot of pressure to unify their behaviour as much as reasonable, while still appearing somewhat different. And even when platforms differed (slightly), two applications on the same platform never did - something Linux still struggles with to this very day, with the misguided idea that it's the *application*, that should pick the GUI, rather than the user. What did "advanced" users do? They utterly and entirely ignored it, happy with their proprietary (funny, eh? :)) and incompatible CLIs. Advanced users are a lot more invested in their platform, simply because the invested so much time an effort in becoming proficient *in that one platform*. Advanced users are the bane of progress. So the solution isn't to make everyone an advanced user, quite the opposite. Expect no effort from your users. Start with environments that try to standardise their interfaces - use the same keyboard shortcuts, naming conventions, formats. Think about accessibility, not just efficiency. Sure, `ls` is fine if you have a horrible keyboard or you can't type very well - but `list` is a hell of a lot more accessible. Use aliases if you need to, but even those should be conforming with other systems - you're not going to keep carrying your aliases over to other computers you need to use; just stick to defaults. Kick out anyone who doesn't play nice. Get rid of the hipsters, who not only can't recognise progress - they *sneer* at the very *idea* of progress. A nice, compatible and mostly standardised interface will give you the inertia you need. Applications like Norton Commander, not command-line `ls`. Applications like Turbo Pascal, not vi. Search by wildcard, not regular expressions (but feel free to keep the advanced option!). Sort "by human", not "by computer" - `Folder 100` should never end up in sort order between `Folder 2` and `Folder`, deal with it. Learn everything the graphical OSes did right, and use it too. Don't consider remote terminals too much, even smart terminals - you'd never get a real interactive applications there - bandwidth is less of an issue than in a graphical application, but latency is just as horrible; in some cases even more so. Standardise rich terminals, streaming-text-only isn't good enough by far, and neither is just text positioning on a fixed background. Make it *real* smart, like what true GUIs managed to do. Keep focus on freely integrated systems, rather than large proprietary bags of tricks (and no, keeping it "FSF" or "OSS" doesn't make it any less of a "large proprietary bag of tricks"). Have developers all over the world coöperate on what they're doing, rather than competing purely out of spite and other misguided initiatives. Find ways to engage users, improve their productivity, instead of arbitrarily introducing differences just to make conversion harder. Instead of ten competing packages "of everything", modularize - give users easy way to make choices without making things appear too complex. Remember how Turbo Pascal, despite being an IDE, actually allowed you to plug-in a custom linker, compiler, debugger...? Encourage that model. The company that's great at writing compilers isn't necessarily the best at linkers. Introduce productivity and discoverability features like auto-completion that mostly had to wait for GUIs in our history. Does that leave us with all the problems solved? Almost. There are still things that graphics just does better. Layouting is much easier with higher resolution, resolution-agnostic design is much easier with higher resolution. Allow improvements over the text-mode ideal - for example, allow combining multiple "tile" sizes on one screen, so that you can e.g. have text written "as-if-in-80x25", while allowing other elements to be "as-if-in-80-40". Allow graphical elements to be included in a text-mode application - so that you don't have to keep changing the whole screen just to have a WYSIWYG look at your document, or to show graphs inside of a spreadsheet. This is the truly complicated part - at some point, it becomes harder to justify that having two ways of doing fundamentally the same thing is a good thing; why have "hybrid" rendering on a Haswell machine, when you can render *everything* in graphics mode just as quickly, while keeping things simpler and prettier? Use accessories that can exploit extremely cheap low-resolution displays to keep better track of your whole system - or even give you cool graphical "pretend" interface in a similar way those Nintendo Mini-arcades had, without giving up on the benefits of text-mode? [Answer] Your link gives a clue: > > The Xerox Alto systems, because of their power and graphics, were used for a variety of research purposes in to the fields of human-computer interaction and computer usage. > > > They built a GUI that is recognisable as the concepts still used today, *and then* researched human-computer interaction, which presumably just refined the ideas already raised, but more cynically may have justified the preconceived notions. An early “bright idea” got funded, and directly inspired the major GUIs that appeared in consumer products. Arguably, the ideas were ahead of the hardware and early implementations were inferior to what *might* have been. If some different “bright idea” got researched, studied, and refined in the early days before commercial products, we might have gone a different route. In fact, a paradigm that was not so graphics intensive might have done *better, sooner*, before machines got powerful enough for the GUI to really be practical. Then, if the general public had caught on to concepts that transcended “direct manipulation” and “what you see is what you get (what you see is **all you got**)” like was felt by the experts, then even when things got prettier the notions of direct manipulation (only) might not make the same inroads. It would be cool to know what concepts / manipulation paradigm *might have been* developed that would be better than a plain CLI. [Answer] Amazon Echo, Alexa, et al, are computers without a GUI. Heck, I even say OK Google to my phone to get it to do stuff like text my friend (Funny story: No matter what I said to my first cell phone with speech recognition, it always misinterpreted it..."Call mom", "Calling Brian". "Call Neil", "Calling Brian".) I predict that in 10 years we won't interact with a GUI as much as we talk to it or use "texting" (eg natural typing) for those times when talking would be rude (such as on a plane) [Answer] Have everyone in your world have **bad to zero eye vision**! This will enforce the need for **screen readers**. Screen readers with GUIs are a real pain. It is much easier to only read text than describe a window for example. Maybe this will have some more implications on your world, but it is definitely doable. [Answer] There are a few general ways to make modern computers that are not GUI intensive. **Change Computer History:** This is somewhat of an obvious choice, because there were a few big pushes in computing that made the GUI happen. On our own planet Earth, computers became huge in the countries that won WWII and the cold war, A.K.A. Britain and America. This connects to a recent network question, "Why are all coding languages in English?". So, what's important about that? Well, America is a capitalist country, every company that hopped on the computer bandwagon created their own coding language. Just think about today, we have Haskell, C, C++, C#, Java, etc. For command line we have the Cmd on Windows, and terminal for Linux and Apple. But what if the government got more involved. In 1965, America passes a bill that makes one American coding language, which will be used in all programming and command line. It will be developed in a similar project to the Manhattan Project, drafting the best minds in computer science, who all have to work together. All of a sudden, a huge barrier to entry is diminished, people only have to learn one new computer language instead of seven. The government also decides that they want the most powerful computers possible to run missile guidance systems, nuclear subs, etc. They don't have time for fancy stuff like graphics. The drive for "a computer on every desk", never happens, instead the government puts a computer in every school for kids to learn. Now those kids grow up and buy their own computers, using nothing but command line. Eventually, the technology is released to the public and a new company makes the GUI, but no one cares about that fluff, as it is in an alpha stage and is pretty crappy. It is seen as a dumb luxury like VR in the 90's and won't take off for at least another few decades, if ever. **Limit Computing:** As mentioned in another answer, the internet rules much of our life. And when bandwidth was low in the 90's we didn't send sweet memes, we sent ascii, or just words. If the bandwidth is limited, all of a sudden, images go away, the internet is text-based. Now, if you take away non-connected desktop, the government says all computers must be linked to the net at all times, there is no longer personal computing, the biggest factor is bandwidth. If bandwidth is limited, no GUI. **Limit People:** Not a great option, but if people are blind, GUI is unimportant. If people are colorblind, people don't like the way the GUI looks. It cannot convey as much meaning, so it isn't used. If people have no hands to use it, then they have to use voice dictation instead. In these cases, GUI is never bothered with. [Answer] **pre-1988**: Xerox hires a brilliant legal team **1988**: Apple files suit against Microsoft, and Xerox against Apple, same as real timeline. --- Then a lot happens in 1989-1990: **Xerox wins** or settles to their advantage, the patent infringement case against Apple. Then they join as plaintiff in the Apple-Microsoft *look and feel* case and win that too. *[in the real timeline, Microsoft won the look-and-feel case in 1994, and Xerox lost theirs]* **Additional Lawsuits** related to Americans with Disabilities Act (ADA) infringement issues. Companies that developed early GUIs without accessibility features or automation capabilities settle or are found liable. Xerox escapes liability because their GUI never left the lab, and their legal team is awesome. Apple and Microsoft are liable for civil damages despite losing IP rights to Xerox. *[in the real timeline, ADA rules have no teeth until 20+ years later]* **New government regulations**, riding on public opinion in support of the ADA requirements, make accessibility and automation capabilities mandatory on all software, and introduce federal education funding and standards for **text-based computer literacy** in the USA, quickly cloned in Japan and Europe. **Apple re-brands the MacIntosh as a toy** and pulls out of the educational market. **Microsoft delays the launch of Windows 3.0** to remove features that infringed on Xerox's patents and add ADA compliance features. The resulting product is late, unusable, has no ecosystem support, a total flop which burns consumers and investors. **On Linux**, X11R6 development stops for lack of volunteers and although you can find early versions, they have become illegal for lack of accessibility features and unmaintained (like [DeCSS](https://en.wikipedia.org/wiki/DeCSS) is today). --- **1992: IBM launches OS/2** and nobody notices. *Same as real time-line* --- Finally, by 1995 GUIs are both academically and commercially dead: **Apple pivots to voice control** as they continue to be a leader in User Experience, to compete against text interfaces. **Microsoft recovers** from the Windows 3.0 fiasco by investing on a 32-bit version of MS-DOS to compete against a now GUI-less Linux. **GUI experience is now hazardous to your resume**. **Venture capital and research funding for GUIs dries up**, like an extended version of [AI Winter](https://en.wikipedia.org/wiki/AI_winter). **Tim Berners-Lee** decides to focus on creating a free version of [Gopher](https://en.wikipedia.org/wiki/Gopher_(protocol)), abandoning work on HTTP/1.1 and X-Mosaic, so a GUI-based Internet never materializes. **Xerox kills all GUI research** and never launches a product. They retain all patents even during bankruptcy, preventing others from launching a product. --- So in this timeline there is a roughly 10-year period between 1985 and 1995 where GUIs struggle to gain popularity and ultimately fail on multiple fronts, a full 20 years before "modern general-purpose computers" come along. [Answer] How about an option that relies neither on crippling your people, nor on them consistently being irrational and/or unimaginative? ## Make the displays expensive. If a *live* (that is, displaying data as that data is created) graphics-capable monitor or a projector costs as much as a car or even a house, most families aren't going to be buying one. But businesses and governments could afford to purchase some that their artists, designers, engineers, and scientists can use to work with. Most people would be stuck with printers, or possibly character displays possibly made using relatively inexpensive technologies such as flip-dot (or flip-segment), LED segments, or nixie tubes that, at least in your world, are unable to be shrunken down enough to make a useful desktop graphics display, but are sufficiently compact for a workable desktop character display. This does, unfortunately, mean that live television is likely to never become mainstream. Movies however, should be fine, possibly even at home. Rather than showing them on a real-time graphics display like we do in the real world these days, just use a projector and film. The key characteristics of film being that displaying it is simple: just shine a bright white light through it with a lens to focus it, and that it lacks a fast write to read turnaround time, so it's unsuitable for live graphics. Television may end up more like an audio-visual newspaper or magazine subscription, with film delivered to your door on a regular basis, rather than a live broadcast. For those wanting a print preview in their home, simply add an extra cartridge (or several, for colors) to printers, filled with dry erase ink. Bundle in some laminated paper, and there you go: print a preview with the erasable ink onto the laminated paper, look it over, then print the final result on regular paper with permanent ink while erasing the preview paper for reuse later. [Answer] ### how can I reasonably explain that GUIs never became mainstream? Computers entered the mass market at the same time as useful speech recognition and synthesis. Instead of sitting in front of screen and pressing buttons users primarily converse with computers. Which would make the concept of a GUI sound strange "What do you mean I have to learn to press this an that and then that? Why can't I just tell it what I want?". [Answer] Make the computers interconnected and bottlenecked by bandwidth. A low-bandwidth internet forces one to optimize the transmission of content, which is likely text-based. From my own experiences with the initial stages of the internet, a GUI is barely usable across a network when bandwidth is low enough. Even a GUI-system specifically designed for client-server networking, such as X, is bothersome on connections like a 14k4 modem. Before the WWW existed we used the Gopher protocol to browse information systems across the world over dial-up connections. Then the WWW was invented and the internet became more graphical, performance on graphical browsers (*Mosaic*, *Netscape*) was still agonizingly slow. Since the textual content was still the main attraction many early users used text-based browsers such as *w3m* and *lynx* to browse the web. On linux servers successors like *elinks* are still used today. If there was some reason for bandwidth to simply remain constrained then GUIs might not develop at all. People would likely still create ASCII-art and TUIs would improve, maybe supporting multiple windows like *i3 window manager*. [Answer] You want a world where computers are widespread but GUIs don't exist? Simple: Find a way to make a world where everyone is totally blind - perhaps even where eyes were never able to evolve. (writing uses some equivalent of Braille) [Answer] **Educate the public quickly** GUIs are popular because they're easy for new users to learn, and don't require as much specialized knowledge as using a CLI. For example, to change file permissions through the GUI in Linux, you can click little check-boxes labeled "read", "write", and "execute", while to change the same information with the CLI, you need to remember which bits correspond to which permissions, and do a decimal to binary conversion. If, for some reason, computers classes became a part of compulsory education during the time when CLIs were still popular, an entire generation would grow up using them. When GUIs emerged they wouldn't seem to have much of an advantage over CLIs to the public at large. Further, CLIs - especially whatever shell(s) taught in school - would have the inertia of consensus, and people would be unwilling to change. [Answer] If the users are non-human, a GUI interface may present serious issues. Maybe they have compound eyes, like insects, and any sort of pixel-grid display creates serious moire fringing effects between the screen and their eyes. Or maybe they see in sonar, like bats or dolphins. How do you make a sonar screen? If they are (almost?) human, maybe their society is a strict meritocracy (with fascistic overtones). You are not allowed to access a computer until you prove that you are intelligent enough to use one in an intelligent manner. In other words, program one. By the time you are a half-decent prgrammer, you will probably prefer a command-line interface over a GUI interface for most tasks in any case. (If you are any sort of geek, you'll have heard the jokes about lusers and drool-proof keyboards. In this world, the geeks are the rulers). [Answer] I don't think this is possible, if you want to keep the possibilities of modern computers, especially if you consider Norton Commander as 'text' - since what it's really doing is abusing text to be a GUI - and most of what GUIs do is *position text, outside a grid system*. But one possible approach I haven't seen mentioned in other answers - text is machine readable, GUIs aren't. This could come up in several different ways: * **Mandatory software quality testing**, coming in very early on. As soon as the first software with bugs appear, and companies realise they are paying for broken products, particularly if there is a serious catastrophe like an exploding space rocket, there is a big legal and regulatory push for software to be absolutely as described, with large fees for any bugs found. + This manifests itself as precise specifications for input and output, and mandatory automated testing with regulatory oversight. You can automatically verify the text which is displayed, and the screen output at every state, but you can't easily automatically verify the display of a curve, and the number of possibilities with user resizable windows makes it infeasible to attempt. * Mandatory auditing of one sort or another. All input and output must be audited for anti-fraud, or to guard against anti-consumer practices, or to mandate that computer systems from different providers perform the same way, or as a basic expectation in a digital society of how computers behave. You can audit typing and printing, but you can't really audit mouse clicks and GUI scrolling in the same way. You can audit "this picture was displayed: {}" for use with your one-off output specification, but you wouldn't want the overhead or storage costs of auditing every frame of a GUI. * The earliest developments of computing were very focused on interpreting the text, and processing it in custom ways. e.g. government broadcast news over a text feed like the UK's old [Ceefax](https://upload.wikimedia.org/wikipedia/en/6/66/Ceefax.png) systems, and individual people put keyword matches on the data stream which would alert them for things they found interesting. Businesses alerted on transactions, individuals played with data sets in real time - you could expect a feed of special offers from shops, from weather services, from news services, civil engineering (roadworks) in your area, up to date electricity prices, or whatever, and pick up on the things you care about. This happens early enough in your timeline that it gets embedded into the culture, and when GUIs come along, people regard them as a novelty but ultimately reject the way they can't be automated and pattern searched as too limiting, so only use them as an output device, but not as the main interaction point. You work with the structured data, maybe you show it in a GUI if it's a graph, or maybe you don't. * The previous points interact; mandatory auditing means governments want a continual stream of input from every user, which they can search and gather population-wide statistics for, which means GUIs are only allowed to be used for display, but all input must come through a keyboard. --- The section of Mandatory software testing could come up in another approach, the reason headless servers are so popular today is that less code means a smaller attack surface for security considerations. If all software had to go through an expensive regulatory audit process (or any constraint which has a similar effect - software companies need to be insured against the risk of their code going wrong, and insurance companies charge per line of code insured, or per feature), then 'less code' would push industries towards preferring TUIs if at all possible. Since a GUI has to display text, and also graphics, it will always work out more expensive. --- Another possible deviation from real world history is that our early output devices were RADAR screens and [oscilloscopes](http://figures.boundless-cdn.com/12858/full/ur-1-zu-3-28oszilloskop-29.jpeg), with an electron beam being scanned left to right and modulated up and down by an analog signal. They became CRTs, which were the dominant display technology for many years. But what if CRTs couldn't become dominant, e.g. if regulatory limits prohibited vacuum chambers in devices sold to the public, because they were too dangerous due to the risk of implosion? --- Environmental concerns, or financial rent-seeking behaviour. If you could tweak the world so that displaying a picture cost significantly more, each time, people would avoid it for normal use. e.g. if there was a 'text' screen which came with a computer, and you could buy a 'graphical' screen as an addition to go alongside it - but it could display 1000 graphics before the license ran out and needed renewing, or it cost a day of text electricity to update compared to the text screen. The market would sort out how to do everything by text, while keeping GUIs available for the occasional use, or for the wealthy. [Answer] Do a better job of teaching kids to read and write. Let's draw a line between a system that is capable of doing graphics, when appropriate, and the GUI, which is to computing what "point & grunt" is to language. So your computer user has what I have on my machines (4 on or beside my desk at the moment): a window manager running on top of X, which mostly has a bunch of xterm windows on it. To interact with the computer, I use language in the form of commands, rather than pointing at something and clicking the mouse. Now this doesn't mean I can't do graphics. I can do anything from looking at photos I've downloaded from my camera (with text commands) to viewing PDF documents (which I may have created with text-based LaTeX) to visualizing the output from the 3D seismic tomography program I'm working on (the input to which is text). I just don't have to have an icon that I click on for every single thing I want to do, and I don't have to waste time trying to figure out what those icons - potentially multiple thousands of them - are supposed to mean. (If I run into an unfamiliar text command, I can look it up in the manual or with a search engine, just as I would look up an unfamiliar word in a dictionary.) If I need a list of commands for users not familiar with a system or application, I can use text menus, as in fact I do with the browser (qupzilla) that I'm using at the moment. It has some GUI icons. in a bar across the top, but I've never figured out exactly what they mean, because there's a handy text menu too. GUIs, IMHO, are basically a crutch, needed because a large fraction of the population seems to be functionally illiterate. [Answer] Try and look at 'what' you actually want to use computing for. Will everyone still be as connected as they are these days? if so, could they just be using more powerful versions of the early mobile phones which had buttons and an LCD screen (my old Ericsson A1018 was like this.) Or are you looking more for a computerized world, but without necessarily needing the level of user input we have now? I mean for instance, look up 'internet of things'. The basic concept is everything around us now has a computer in it (kettles, toasters) which are all inter-connected to form their own network. However, the micro-controllers within them fairly rarely have a GUI. At most, there are a lot of blenders/food processors which have buttons on them for 'smart' cooking. These are dedicated function buttons, while the micro-controller inside simply (or not so simply) reads the data from a few sensors and applies some logic to the cooking mode. The Raspberry Pi is another good modern example. Although it is typically connected to a mouse/keyboard and TV/monitor, it needs none of these things to function. I've seen them set up as wireless computer servers; one of my colleagues has half his house automated with micro-controllers, including wifi cameras and his 3D printer, all connected through the Pi as a server. He can access his printer at work, and watch it on the camera to make sure his house isn't on fire, but the point is the Pi itself has no GUI, and the tablet or whatever he uses to access it isn't more than a dumb terminal. IF you're talking purely about how to access the computer without the graphical interface, then the next level up (or down) would be the old DIP switch and jumper approach to computer programming/usage. I have an early Amstrad PPC512 laptop at home which consists of a monochrome LCD screen, two floppy drives, a modem and no hard disk or any sort of operating system, other than what is used on the boot floppy. Setting which floppy, or external monitor source etc. was done with an array of DIP switches on the side. There are plenty of other good examples through computing history: the Apollo computer used during the moon landings had the DSKY interface, which was fitted with dedicated function buttons (noun, verb) and 7-segment readouts. Graphics calculators would be another example you could 'borrow' and modernize. TLDR: Your world started with pre-GUI computers such as the Apollo guidance computer. Instead of the desktop computer/monitor becoming standard, research instead went into portable computers such as graphics calculators and early mobile phone technology, while industry focused on single use computers programmed by DIP switch. By the time mainstream internet became available linking the IOT devices together, people still predominantly relied on text-based systems like their button phones. Something a little less anachronistic would be that, or haptic feedback devices (vibrators, or braille keypads) were invented sooner. Maybe AI was developed earlier, reducing the need for 'hands on' computing, although this begins to overlap the voice-activated approach as mentioned in a previous post. [Answer] Are you bound to the users being human-like? If the user's senses are not dominated by vision, you can neglect GUI, and go more on a tactile/sound/smell user interface. Basically you can image a mole-like being using a computer. [Answer] Most of these answer focus on technology being held back, I am going to assume it sprints forward. Direct communication with the computer via brain waves over wires invented before GUIs. If you use telepathy or neural implants to communicate with your computer no keyboard, mouse, GUI or etc are necessary. You have a direct brain to computer link with vastly superior reaction time. The only possible problem is people might choose to visualize a GUI in their mind. However, I doubt that it would be helpful with direct computer to brain linkage. [Answer] 1. Before computers are powerful enough for graphics, heavily invest in computer science education, starting from primary school. This would likely be a sound investment anyway, at the very least in hindsight. 2. Everyone will be able to use a terminal. You can't teach theoretical computer science to first graders (also large parts of it wasn't known back then), you'll start with a very practical approach to computer science, which implies heavy use of actual computers; programming. That's the part which is useful to the general population anyway, so they can automate little problems in their daily life/workplace. 3. Everyone will be able to use a terminal more efficiently than graphical programs because they already know how to and terminals are inherently better so the investment to learn GUI wouldn't be worth it. 4. There would be no need for graphical user interfaces. That is, there would still be graphical output, but only for stuff like previewing 3D models you describe textually (it exists! It's really easy to learn and powerful in my opinion), previewing documents you wrote in something like LaTeX, viewing pictures and videos, etc. ]

[Question] [ Humans are savage creatures. This is indicative in the way they get rid of bodily waste. Squatting over a glorified hole in the ground or aiming their spear tip toward the same hole and hoping for success is a matter best left to barbarians with no dignity or self respect. For this, you are to be pitied and belittled. We elves naturally developed a method that is more worthy of our nature. Our bodies are far better at breaking down our food, leading to cleaner digestive systems. What little waste remains however, can't just sit there, otherwise it would poison us. How can it be removed without exiting the anus? [Answer] Pooping is far less disgusting than any other solution if you think about it my dear arrogant Elf. The most natural method as an alternative to Pooping would be puking like some other lower life forms. I havent looked into Elf Defecation but considering your self-important race thinks Pooping is disgusting I expect not. I see one of my esteemed colleagues has suggested the possibility of locking your waste products in hair, but here the gross part starts. Humans eat and do not absorb materials from their food that is waste anyway, then add bodily wastes to that which they poop out. If an Elf grows it in their hair, that waste has to go into their bloodstream and slosh around their bodies until it finally is collected and build in their hair. It's a dirty process that would cause many bloodborne diseases and vasculairy problems. And what about liquid waste? Humans pee it, and a small portion is expelled in sweat. If your race does not pee, all it has left is to sweat it out all across their bodies, or pant like a dog if not to spit it out, only to have traces stick to their skin and mouth. No I do not think even Elves are as filthy to forgo the simplicity and cleanliness of standard defecation, otherwise I would refrain from ever coming close to any Elven seers I meet, as their repugnant smell and disease ridden body would warn me long before I would have the guts (hah) to meet one face to face. Due to the lack of stories about constant disease and stinking filth surrounding you Elves, a racial taboo on the entire process is all that I can name to be the culprit of such nonsense that you do not use an anus to defecate or bladder to rid yourself of pee at an appropriate moment. [Answer] **Wastes are incorporated into hair.** Wonder how the elves accomplish their flowing locks? How an elf seems able to try a new hairstyle every week? It is all about the hair. The elven keratinocytes lock up indigestible fiber, waxes, and other materials delivered from the digestive tract and sequester it within long flowing tresses. This added material means that an elf will need to cut his or her hair every few days or adopt long Rapunzelesque braids. As for nitrogenous wastes, these too are expelled by glands associated with the hair, giving it that glowing sheen. Commensal microbes on elven heads partly metabolize these wastes, giving elves their characteristic smell of caramel and violets. [Answer] If you insist on **no solid waste** you would need to break undigestable molecules down to liquid or gaseous forms. A major problem if you want to avoid any excrements is that you would have to break fibers and other undigestable contents down completely until the molecules are small enough to be assimilated by the body and then expelled through the breath, sweat glands or urine. These fibers leave the human body undigested because breaking them down is either impossible in our gut (due to missing enzymes) or needs more energy than can be extracted from them. So what do elves do instead? Their digestive tract doesn't end in the anus, but curves back and attaches to the lower end of the esophagus. There it forms a little pouch-like organ, just like the stomach, but this one withdraws even the last traces of water from its content. Due to the highly efficient digestive system, only a tiny amount of waste ever gets into that pouch, building a thin layer over the waste already contained in it. They practically produce pearls of their bodies waste. When the pearl gets big enough, it's transported up the esophagus and spit out. In true elven fashion they either sacrifice it to the earth as fertilizer or literally sell sh\*t to those stupid humans. [Answer] > > We elves naturally developed a method that is more worthy of our nature. > > > I would modify your premise, which I will get to in a moment. First, we humans preprocess our food to make it more edible. We peel it, we core it, we throw away the seeds and stems and leaves, and often skin, bones, organs and any other parts we don't like. We cook it, to make it tender. Elves that thought elimination was not worthy of their nature have simply taken this a step further: They prepare their food to eliminate waste **before** they eat it. They have a superior digestive system, but still, they remove all indigestible components from the food they eat, and if that is not possible, they don't eat it! The same thing for drinks. The method they developed lets any excess liquid they ingest be quickly evaporated from their sweat. They limit their intake of fluids to match their capacity to sweat. It would be like getting all of your calories from honey. Their pre-processing and cooking method produces food with no residue. Also, much waste in the human body, like toxic chemicals, goes to "garbage dumps" other than the colon or bladder: Ear wax, sweat, tears, hair (on the head and on the body), finger and toe nails, skin. Any microscopic indigestible waste could do the same; it emerges as a thin film on their body with their sweat that is washed away whenever they bathe. [Answer] Elves do have anuses, it's just that they only have one common use with human ones. For excretion, though - elves have developed a symbiotic relationship with an insect, a dog-sized variety of [phasmatodea](https://en.wikipedia.org/wiki/Phasmatodea). The insect is carefully (for dwarven standards) shoved up the elven cloaca, where it can eat and drink whatever is there. This has the benefit of not requiring a sitting position from the elf, so while they mostly prefer to do this while lying down on a bed, they are free to walk around with a monster hanging from their derrieres if they want. You know how every joke can have its truths? When pilgrims and explorers say that an elves have a giant stick up their [be nice], they are being literal. They probably witnessed, during their travels, an elf walking around during their daily cleanup. P.s.: this has been featured in (serious) sci-fi literature before. In Arthur C. Clarke's *Rama* series, there are aliens who do shove bugs up each other's [be nice] so that the bugs can eat their excrements while inside. [Answer] # Dryadism (is that even a word?) The Elves have evolved a symbiotic relationship with their grove. Every now and then, they will either lie in the glade, or be swallowed up by their home tree. In both cases, tendrils from the grass or tree will enter the pores, and locate the apovlitocysts - the deposits of waste material accumulating beneath the dermis - through [chemotaxis](https://en.wikipedia.org/wiki/Chemotaxis). There, they'll inject a cocktail of enzymes that liquefies the deposit, allowing them to suck it dry. The plants will also supply vitamins and feel-happy alkaloids in exchange for the bounty of readily-assimilable nitrogen and nutrients they're offered, not unlike the [Nepenthes lowii](https://www.nytimes.com/2009/06/16/science/16obpitcher.html) that supplies its customers with sugary nectar. The alkaloids have the primary purpose of getting the elves relaxed and in a stuporous state. Not that the Elves are aware of this happening, since the gory details are even more disgusting than the human solution. They only know that with the passing of time they get slower, irritable and more tired, like a human with sleep deprivation; and the communion with the grove leaves them rested, refreshed and rejuvenated. And, of course, staying too far away from the grove for too long kills them. The relationship evolved from a predatory one in the depths of time - the plants had already evolved the "get them high and kill them" trick against small animals. The effect on the elves' primate ancestors was much less due to their greater mass, and they mainly got a high from lying in the carnivorous grass. So they started doing so. The plants had to be content with absorbing superficial matter, dead skin, oils and the like; but they evolved tendrils to scavenge more and more, while the elves evolved to avoid the ill effects of the tendrils themselves. Down that road, the necessity of expelling the matter accumulating in the pores - a necessity which elves shared with humans (there are several disgusting videos on YouTube promoting 'beauty treatments') - grew less and less. Eventually, all mechanisms to drain pores to the outside atrophied, outsourced to the grass. Proto-elven organisms then started finding more and more convenient to use subdermal cysts to get rid of waste material, where it magically disappeared after a while. A couple million years later, the elves' lower intestine is little more than vestigial. At the same time, their diet is somewhat restricted in quantity and nature (they make up for it with lengthy and elaborate preparations that put to shame humans' *nouvelle cuisine*); were an Elf to eat large quantities of indigestible matter, he would get [spectacularly sick](https://en.wikipedia.org/wiki/Rumination_syndrome). While rich in sugars, base proteins and water, elven food is not automatically digestible by humans - to increase their digestive efficiency, elves also evolved a commensal symbiotic gastric flora that can break down most vegetable matter and complex carbohydrates. On the negative side, *erumëloirë* is an Elven poison that acts by killing off most gut bacteria, leading to a condition similar to wasting sickness from which recovery is long and difficult; this class of poisons have almost no negative effect on humans, who call them *penicillins*. [Answer] You just have a rather more advanced version of the owl's digestive system. In owls, hard & indigestible parts of the prey are formed into pellets, and vomited up as "owl pellets": <https://www.carolina.com/teacher-resources/Interactive/basic-information-on-owl-pellets/tr11103.tr> Your elves expand this to include all the waste. Though I'm not really sure this would be considered more dignified than the way humans do it :-) [Answer] I'll try to do this delicately. They have a plant beside their bed that extracts the excrement nightly for fertilizer. They never have to deal with it themselves. The plant applies a neurotoxin that deadens the entry and removal sensations. They wake up in the morning refreshed and empty. When traveling, they carry a seedling that performs the same function. Over the course of history, most if not all have forgotten how this works. They simply keep the plant nearby due to tradition, or as a good luck charm, or as a constant connection to nature. The symbiotic relationship is forgotten, but haughty attitude and physiological features remain. [Answer] It is hard to reconcile “the wee little people” of legend and the sharp-shooter tall-blond-and-handsome elves that we meet regularly. The answer is simple: elves are born quite tiny (within acorns, frequently). They excrete nothing. The hard matter that cannot be digested is embedded in their bones at astounding densities. If you’re going to have dexterity of an elf, you need bones that won’t shatter when you jump down two stories or leap tree-to-tree. It takes a century of eating to get enough material for human-size bone structures, but elves are long-lived creatures. [Answer] The elves are full of it. It's true that the elven anus is pristine. In fact, it's part of a secondary respiratory system that's used to bring oxygen to the digestive tract to allow them to process food using aerobic as well as anaerobic bacteria, which is part of the reason they produce much less waste in the first place. Being elves, [they also use the anus to produce music of unearthly beauty](https://en.wikipedia.org/wiki/Flatulist), of course. But, contrary to what they tell the other races, elves *do* produce waste. Not nearly as much as humans or dwarves (plus, they don't eat nearly as much in the first place), but over the centuries, it builds up. Because they have no way to dispose of it.1 Elves are immune to the ravages of age, resistant to all diseases, and difficult to kill in combat. As Tolkien explained, elves usually only die by fading away willingly, when, after long millennia, they've "lost the will to live." Which sounds nice when an elf says it, but what they really mean is that they're sick of living with constant severe indigestion.2 Why do you think those great elf lords always have a pinched face and a curt manner whenever you speak to them? They'd have you believe it's because they find it distasteful to talk to someone as lowly as you, but the truth is, they're the same way with their spouses, children, and co-councilors. They're perpetually in a bad mood because they're perpetually uncomfortable, and it gets worse with every passing century. --- 1. Elven legend—rarely shared with the other races—has it that after death, their spirit can be reformed into a new, waste-free body. And, in fact, there are a few apparent cases of ancient elves returning from the dead. With the wisdom and experience of millennia, but the digestive tract of a newborn, they tend to be unsurpassed both as warriors and as dinner guests. See Tolkien's description of Glorfindel for an example. 2. Tolkien even describes it as "**wasting** away". [Answer] ## Toxin Sacs As mentioned in the question, the Elven biology is exceedingly efficient at processing food and drink. However some substances are so toxic, that they can't be completely processed and recycled. These accumulate (at a very slow rate) in small glands in the forearms, and thence to the the elf's fingernails. It takes on average three years for these sacs to become full to the point where the waste must be excreted, however they can be released at will when needed (or occasionally, autonomously in high adrenaline situations) when an elf is forced to fight while unarmed. While an elf-scratch probably won't be immediately fatal, it will be exceedingly painful, is much more likely to become infected, and almost immediately causes dizziness and fatigue. Some elven cultures make it a point of pride to keep their toxin sacs empty, releasing and cleaning at least once a month. Being from a "higher society" they have no need of the primitive defenses of their forebears. In some other, more violent cultures, they do their best to keep their sacs full all the time, so that they can scratch at a moments notice. These elves wear gloves when they eat to avoid poisoning themselves from their constantly tainted nails. Most elves however fall somewhere in between, getting a yearly manicure were the toxins are drained. [Answer] I was *very* tempted to just give the joke answer of "just have them vomit it up, duh!" but I'm not going to do that. Instead, make it so their digestive systems break everything down to a fine liquid (if you want more detail on how to do this, make their digestive systems have the right enzymes to reduce anything that goes in there into a liquid. This liquid is then spread out extremely thinly and leaves the body in their sweat. [Answer] Elves can simply just have a more efficient digestive system. Encyclopaedia Britannica gives a breakdown of what feces is composed of [here](https://www.britannica.com/science/feces). > > Normally, feces are made up of 75 percent water and 25 percent solid > matter. About 30 percent of the solid matter consists of dead > bacteria; about 30 percent consists of indigestible food matter such > as cellulose; 10 to 20 percent is cholesterol and other fats; 10 to 20 > percent is inorganic substances such as calcium phosphate and iron > phosphate; and 2 to 3 percent is protein. Cell debris shed from the > mucous membrane of the intestinal tract also passes in the waste > material, as do bile pigments (bilirubin) and dead leukocytes (white > blood cells). > > > Humans, can't break down the undigistable food, but that doesn't mean other organisms can't. Basically, elves would just need a source of enzymes like cellulase and pectinase. Whether it's symbiotic with other organisms like bacteria, or a gland that produces if for them is up to you. Likewise, the other stuff like fats, proteins, and inorganic substances can all be taken care of with a more efficient digestive system. At that point, all you have to deal with is the dead stuff your body produces (bacteria, cells from the intestines, etc). This can be handled a couple of ways: maybe elves don't produce as much of this stuff. Or maybe instead of having the digestive track end with the anus, have it end with an organ (essentially a second stomach) specialized in breaking these things down. Once the solid matter is dealt with, the water is not necessary for a bowel movement, so their body can use it for other things. That means elves need to consume less water to survive (major advantage), and if they do consume excess water, they can just lose it through respiration or perspiration. Any excess chemical elements that their body doesn't need could also be gotten rid of this way. Also, if they can break down things like cellulose, then that means they need to eat less plant matter to survive, and opens up new potential food sources for them, making them an even more efficient organism than humans in yet another way. [Answer] Go with a subversion. Elves are being arrogant and will claim that the concept of the "bath room" is utterly disgusting... but will not detail how elves would take care of such business as it is undignified to speak of. When we finally get lost for a few days with an elf, we find that they do a number two, too. It's just such a taboo subject to talk about they hide their water closets from even their significant others... oh, and not only does their... um... stuff... not only does stink, but it's worse than humans. It reeks! Courtesy of a high fiber diet, your bathroom is now inhospitable for days... and the elf forgot to turn on the ventilation fan because you didn't get that far in your explanation. And he most certainly didn't wash his hands! Why is he claiming his way is so much more refined and better than ours? Well Elven rest rooms all come fully stocked with the very best in hair care products... which is the whole reason they don't talk about that... it's rude to ask you how much money is in your bank account too. That's the real reason they are so dedicated to you not finding out! They didn't want you to know where they kept all the lotions for their luxurious locks, because as the TV told them, they are worth it! They didn't even realize the stench was putrid to us mere mortals. [Answer] It's a well-kept secret that elves are able to crystallize their waste similar to how an oyster creates a pearl. When an elf feels sufficiently backed-up he or she will have an instinctive understanding of what type of mineral should be seeded via their posterior end to start growing a crystal that will accumulate the majority of the waste in their system. Once the crystals have grown to sufficient size they are removed via the same orifice and put to use. Ever wonder where the elves get all those pretty little crystals they light up their tree houses with? Or where all those powdered "mana" crystals they mixed into that mana potion you just chugged come from? The truth is a good portion of elf culture, and their exports, revolve around the fun things they do with their crap. The next time you see an elf with a particularly pinched face just keep in mind... chances are it's probably not you, they are most likely just in the process of growing a "big one". [Answer] Elves don't excrete because their appendices are actually pocket dimensions from another plane of existence. The waste simply builds up slowly over time, and eventually, after thousands of years, it becomes full, at which point the elf shows signs of declining health and ultimately dies of terminal constipation, and the appendix disconnects from our plane, where ultimately it will generate a demon-like being. A little-known fact is that the famous magical items like the portable hole and bag of holding are actually crafted by extracting and preserving the appendix from the corpse of a young elf. [Answer] ## Elves still poop... but their poop is not gross. What really makes poop gross? It is not where it comes out of our bodies but the fact that it smells bad, carries diseases, and has a bad habit of squishing unpleasantly underfoot. If an elf intestine where to fully dry out poop before ejecting it, then this would kill off all the odor causing bacteria, resulting in something as unoffensive to others as a rock. Ofcourse, you don't want to have to force a hard, jagged poop out of your anus, so you want to make sure it's as smooth and polished as possible. So sure, an Elf still has to pop a squat just like the rest of us, but while our waste is something no one want anything to do with, Elf Poop is so nice, human jewelers go out looking for the stuff. [](https://i.stack.imgur.com/rEbT1.jpg) [](https://i.stack.imgur.com/Wc1HO.png)[](https://i.stack.imgur.com/v87Nc.png) [Answer] ## Symbiotic Wood Armor Elves are born with larger pores over their vital areas. Elves are born under the mother tree which is sacred to their species. The tree has poppy-like flowers that produce small seeds and when a baby is born, there's a ritual to cover the baby in these seeds. The seeds are small enough to fill in the pores, it is seen as a blessing -- an offer of protection from the mother tree. The elf's pores excrete sweat filled with nutritious waste that the plant can use to slowly grow. It forms tiny roots out from it to hold itself in place, but then grows outward and forms a hard shell to protect it's source of sustenance. It grows as the elf does, hitting maturity at the same time the wooden armor becomes dense enough to be a solid protection. It's at this time they are able to leave their sanctuary and venture out into the world. A common practice would be to stain or lightly carve the wooden armor. There are master carvers that devote their lives to this. Your family's crest is carved into it when you reach maturity and your loved one carves their own design into it upon marriage. [Answer] **Secretion** (rather than Excretion). Sustenance is systematically broken down and eventually secreted out through pores in the skin. Certain pores may be more dedicated than others, and effectively act as miniature anuses. [Answer] Kroot in warhammer 40000 have pretty clever way to do it. They have a really performant digestive track who let nearly no waste happen. The few material that can't be digested are expelled through the skin by transpiration. [Answer] Solid waste consists mostly of material that cannot be digested and was never absorbed into the body. In order to not expel undigested matter, these elves must be careful to never ingest indigestible matter. They only eat carefully measured amounts of highly processed (perhaps magically processed), liquid food. Many elves subsist only on the nectar of flours they cultivate. All material elves eat is absorbed into the blood. (because of this, Elves get drunk very efficiently). Waste is excelled as a gas by breathing, and as a liquid by sweating. This is what gives elves their characteristic sweat and sour smell that humans find so appealing. Because of this, elves cannot tolerate human food. If forced to eat what humans can prepare they usually opt for water with honey. Even though that does not account for all of their needs and after several days of the substandard diet they get quite ill. [Answer] ## What little waste remains after digestion is excreted through superficial tissues, like hair, toenails, and the skin. Elves are so much better at breaking down food that they can produce new cells at a faster rate. Instead of accumulating in the guts, the residual waste is broken down in small pieces and distributed all over the body. where it can be used as cheratin for hair and toes, or accumulated in the dermal cells. Since dermal cells are built up faster, they tend to be shed faster also. This is not gross as a snake skin-change, as it doesn't happen at the same rate in every point of the body, but still Elves are more prone to the occasional scratching - their fallen cells tend to itch more easily, and maybe, despite their long, beautiful hair, they are more subject to dandruff also. Have you noticed how Elves seem to be obsessed with hygiene? I mean, I bathe myself once every two weeks, and they still look down at me! Anyway, I suspect that their regular baths (one a day to keep the darkness at bay) helps them get rid of the excess skin, that is, after all, waste material. [Answer] In humans and other being evolved from animals with a digestive tract, there is an entry point for ingestion, and one (or more) for excretion. And extraction+transformation of input matter is done over the length of the tract. Elves are ***not*** evolved from humans/animals. They are spiritual beings who look, function similar to humans from an external perspective but do not have the same inner functionality since they descended from ether/spirit. Therefore, the matter that they consume is turned to spirit. i.e, matter-energy => spirit-energy. However, different rules apply in this conversion as compared to matter-energy => chemical-energy. Just like digestion initially requires energy to break down the matter to chemicals (endothermic process), the conversion of matter to spirit also requires the elf to expend some amount of energy initially. Matter that is closest to nature (plants etc.) and made of the simplest molecules are therefore contain the most spirit-energy per unit matter. Therefore Elves would favour plant based foods (vegetarianism). [Answer] # Diarrhea The elves generally live near places with a lot of water. This isn't a coincidence. This is because they excrete all waste via nr1. In humans, if the digestive system is upset, for example by disease, then it can happen that one of the main functions of the intestines is disrupted. This is the uptake of precious water. The result? Diarrhea. If the disruption is large enough it can be practically fluid with only tiny pieces of excrement. The next step is to combine this with some anatomy of birds. Birds 'toilet visits' contain both kinds of waste from one orfice. The difference here is that the elves have specially adapted bodies to release nr1 and nr2 at the same time. Because of the watering down they go more frequently. As a result you need to prevent dehydration by drinking a lot more. Maybe that us why elves are often depicted as tall. This is mostly storage space for all their waste, so they don't need to go too often to the toilet. Do note that doing both from one orfice does require a more elaborate immune system at the specialised excretion organs. They aren't mixed in many animals for a reason. For males it also serves an extra purpose, so the plumbing gets very complicated. [Answer] # Eggs. Elves don't undergo something so messy as childbirth. Instead, they lay eggs beneath the roots of great trees. Every once in a very great while, one hatches, and the new Elf is cherished. But all the others are simply waste wrapped up by the shell gland. It's neat, and it may deter predators that would otherwise feast on their next generation. ]

[Question] [ How could a Faster than light drive be limited to only travelling between different solar systems, and not within a solar system? I don't really want to allow travel between planets in the same solar system using FTL or allow things like Kinetic Weapons to be equipped with FTL to destroy a planet by slamming into it. [Answer] A guy named [Arioch](http://well-of-souls.com/) has a webcomic called [Outsider](http://well-of-souls.com/outsider/index.html) (highly recommended, BTW) with a simple and elegant solution to this problem. Ships in that universe use a drive that jumps them through hyperspace, but the drive only provides the initial impulse to break the ship out of the plane of normal space; the hyperspace trajectory afterwards is purely ballistic. By ballistic, I mean affected by gravity. Gravity affects objects in higher dimensions as well, and to return to normal space the ship must be pulled back down by the gravity of a large body like a star. If it is not, the ship will be stuck in hyperspace, unable to get rid of its higher-dimensional inertia. [](https://i.stack.imgur.com/otMW8.gif) (Arioch has posted an in-depth discussion of this system [here](http://well-of-souls.com/outsider/forum_ftl_tech.html), from which I have shamelessly stolen the image above.) As a corollary, ships cannot jump from deep in a gravity well, as they would be pulled immediately back down into real space; they cannot jump too deep into a system either, because they will experience sufficient force to snap them back into normal space from the star. Jump ranges are naturally limited by the precision of the drive's initial impulse and the precision with which the desired ballistic hyperspace trajectory can be calculated. Since there are only so many stars within range of any given starting point, this means that ships cannot jump past the front lines of a battle, and there is a meaningful concept of distance between two stars, measured not just in travel time, but in uncertainty about the state of the territory you will be passing through. An interesting side-effect of this mechanism is that despite the existence of galaxy-wide FLT travel there remains no way to get to arbitrary points in interstellar space. The vast, vast majority of space is empty and far away from an anchoring gravity well, and thus inaccessible. Almost anything could be out there... This mechanism fits in well with the IRL hypothesis is that gravity penetrates into higher dimensions, simultaneously explaining observed the stronger-than-predicted observed gravitational effects that are typically attributed to "dark matter" as gravity leakage into our dimensional plane and gravity's relative weakness as leakage out. [Answer] It is common to require that FTL only operate at some distance from large mass. So, the ship must withdraw (say) beyond the orbit of Neptune before engaging. Likewise, ships will arrive at this distance. In some of my [other posts](https://worldbuilding.stackexchange.com/questions/47166/how-does-paradox-free-ftl-travel-affect-the-details-of-my-story-or-gameplay) I also mention the idea of needing to match velocity with the special preferred reference frame. This would require months of travel and conventional acceleration prior to jumping. Another idea, [sometimes used by the same authors](https://en.wikipedia.org/wiki/The_Mote_in_God's_Eye), is to have [special jump points](https://en.wikipedia.org/wiki/Alderson_drive) associated with the stars. You can only jump between the paired “Crazy Eddie” points, not arbitrarily. [Answer] **Make the aiming difficult** If the lowest precision of coordinates you can aim at still has an *error margin* greater than the typical size of a solar system your method would not be usable for travelling distances shorter than said margin. *Example*: Aiming at the sun would result in arriving anywhere between the Sun and the Kuiper Belt (some ~50 AU error-margin). --- *On the chances of hitting anything*: Using the rules defined above we can calculate the likeliness of hitting something as follows: 1. Define an error margin; we'll go with *50 AU* 2. Calculate the volume of a sphere with radius *r = error-margin*: *523'598.775598 AU^3* or *1'752'971'514'717'000'000'000'000'000'000 km^3* or *1.752971514717e+30 km^3* 3. Calculate the volume of all things inside this sphere; we assume the sphere to be centered on the Sun and, for simplicity's sake, sum up the volumes of the stellar object on [this list](https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size#Larger_than_400_km): *1'416'691'835'910'000'000 km^3* or *1.416691835910e+18 km^3* 4. Divide the volume of *all objects* by the volume of *the sphere*: *8.0816592e-13* or *0.00000000000080816592* or *8 in 10'000'000'000'000* or *1 in 1'250'000'000'000* So in contrast, if everyone of the ~8 billion people on earth would do 1'000 of these jumps, then ~6 people would hit something. I'm using the google calculator for all calculations [Answer] First off, there is no realistic way to limit an FTL drive because there is no such thing as a realistic FTL drive in the first place. That is to say, any drive that allows you to physically move faster than light is not only impossible but nonsensical. This is due to a few reasons such as time dilation (time would stop for you), space contraction (you'd go through all space at once), and energy expenditure (there's not enough energy in the universe to get to light speed, let alone surprass it). What you *could* do is arrive at a destination faster than light would, by taking a shortcut. This is the principle behind many of the more **"** realistic **"** interstellar drives. That shortcut may be another dimension (hyperdrives), bending space to make distances shorter (warpdrives) or opening a hole in space to your destination (jumpdrives). All of these have the added bonus that they do not turn your spacecraft into a relativistic apocalypse bullet. Now onto methods to limit these drives to "safe zones": * **Limit through accuracy** - let's say that your drive is extremely inaccurate, that is to say, that if you aim at a star, you may end up *in* said star or you may end up in the fringes of that star system. Given how vast space is, it's fair to say that the chance of accurately delivering a missile to its target is less than slim. The main disadvantage of said drive is its inherent danger, so to do regular trips you'll have to aim far from your actual target lest you want to end up inside it. * **Limit through resources** - make the drive need a special resource to work, some kind of exotic energy only found far from stars. This resource would be needed not only to start the jump but to end it, so people can only jump from the edge of a system to the edge of a system. This can be expanded if you are using warpdrives or hyperdrives, so that you can only travel through "paths" of this energy. This would allow you to fine-tune how you want your spaceships to function and where you want them to go. While I say resource, this can also be the lack of such, like gravity. * **Limit through infrastructure** - make your drives function with gates or portals. You can set it up to work such that you can only jump from, to or both. The main disadvantage of this method is colonization and exploration. Since you'd need a gate to whatever destination you want to go to, you'd need to physically move such gates to every new system you discover. Alternatively, make it so an ancient civilization did all that hard work already and you just discovered the gates (like Mass Effect). * **Limit through countermeasures** - set up "jump inhibitors" near important locations. These inhibitors would limit jump/warp activity in an area near them, like the other methods, they could prevent jumps from, to or both. A network of these inhibitors in a star system would prevent rogue jumps to undesired locations and, depending on the size of the devices, you may implement them in spacecraft to prevent enemies from escaping or from surprising your troops. * **Bonus** - combine these ideas to make things more interesting. Like low accuracy + inhibitors for extra safety or resources + infrastructure for less handwaving. [Answer] The most used options in literature to spice up space travel are: # FTL drive requires local space to be "flat". This can be played in several different ways. The most direct way (e.g. in the Honor Harrington novels by David Weber) is that there is an absolute limit of spacetime distortion, the *hyper limit* or *Warshawski limit*, above which the hyperspace transition simply cannot work. This can have several sub-possibilities such as far-out gas giants or other space phenomena throwing a gravitational shadow of their own. A clever twist of the same concept is at the bottom of Ian M. Banks' *The Algebraist*. On a grander scale, and without gravitation being explicitly added to the mix (actually, the ending of *A Fire upon the Deep* shows that the effect is not gravitational), the Zones of Thought of Vernor Vinge's mark areas of the galaxy where hyperlight is - or is not - possible, whether a star is present or not. A more complex setup has the spatial "bending" as a less-than-insurmountable *obstacle* to FTL due to several reasons, so that more advanced ships or more powerful "compensators" can jump nearer to a star (or a planet). This happens with Raymond Weil's *Slaver Wars* (where different model of engines allow getting deeper and deeper in a planet's gravity well). Even so, the inner solar system can be off limits to everyone. And of course, you cannot reintegrate *inside* a solid object as the gravitational potential is too steep. A twist on this latter concept is that you cannot reintegrate anywhere unless the mass density is very very low, because all pre-existing matter (say gas molecules) will mix with *your* matter at such a negligible distance that it will cause a nuclear fusion event. So you can reintegrate outside Pluto and risk no more than a slight increase in your chances of getting bone cancer. Reintegrate inside a comet trail or inside a cloud of stellar dust, and you'll be literally boiled alive by the waste heat. # FTL is only possible between massive objects such as stars This is, I believe, Niven and Pournelle's *Alderson Drive* limitation. Gravity eddies caused by stellar objects give rise to Alderson Points and "tramlines", and you don't get them except near stars (or possibly gas giants). # FTL requires equipment at *both* ends This is the more "realistic" explanation - FTL violates the currently known laws of physics, and no known natural phenomenon is FTL. It stands to reason that if FTL is possible at all, it requires transition to a normally detached dimension/brane/space/whathaveyou, and real-space equipment to perform de-transition; be it a F'Sherl-Ganni's [wormgate](http://schlockmercenary.wikia.com/wiki/Wormgate), a Fourth Empire's [hyper receiver](https://en.wikipedia.org/wiki/Heirs_of_Empire), or [higher-dimensional wormholes](https://www.goodreads.com/book/show/46257.Starplex). It makes sense to only install these terminals near habitable (actually, *inhabited*) stars. # Space flatness influences hyperspace transition In this scenario, any object immersed in a gravitational field will experience two different "tugs", a larger attraction in the part nearer to the field source, a weaker attraction on the opposite side. This difference is greater the larger the object and the steeper the gravitational gradient. If this difference translates e.g. in different hyperspatial acceleration given a fixed hyperspatial translative force, any spaceship will be subject to a force that will try to rip it at each Jump. The nearer the Sun, the larger the ship, and the faster the hyperspeed, the greater the force. In the end, the maximum ripping force that can be tolerated by a human being will limit the distance from the Sun and the hyperspeed that can be attained. If the maximum hyperspeed, at the distance of Pluto, is very little above light speed, then FTL travel inside a solar system is possible **and yet it makes no economic sense**. # Sidestep the problem entirely - just make transluminal kinetic kill weapons impossible You can use the "Vegas rule" -- whatever happens in hyperspace, *stays in hyperspace*. As soon as your kinetic missile becomes transluminal, it stops interacting with the subluminal Universe, and is no longer a weapon. When it reappears, its superluminal speed *does not* transition with it (not like the hyperplanetary projectiles of Doc Smith's Space Patrol), and the missile reacquires the same speed it had before going transluminal. [Answer] Say that the run-up acceleration to FTL has to be about 10% of light speed, that FTL depends upon a discovery involving a violation of symmetry in the Lorentz contraction (a consequence of relativity), but 10% of C is the minimum sufficiency to exploit this and make the FTL mechanism work. That is 67 million MPH, and it takes about the entire width of the solar system to get that fast and the only known way is too slingshot around the Sun several times, taking a month. And once a ship is **at** FTL, it is not in normal space and passes through normal matter like neutrinos: But like them can be influenced by gravity, meaning the only way they can hit the brakes and drop out of FTL is by using the gravity of another star; they must navigate through the star; which will pop them back into normal space at their original speed, a few million miles from the center of the star. (Ours has a radius of about 440,000 miles; but pick your stars carefully, or make sure you have good shielding if you will still be inside it; or since it is just sufficient gravity that is required, pass through non-center). In response to comment about stopping by gravity assist: If FTL is possible, getting into or out of it is likely a violation of the physics we know, and exploiting fictional physics of the future. I'll accept achieving relativistic speed may not be possible with gravity assist, but certainly achieving the maximum possible gravity assist is a start before we kick in the [nuclear bomb pulse propulsion](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)). Of course my 10% of C is just made up too; the author can make it 2% of C. As far as getting out by flying through a star, I'd say that is **not** a form of gravity assist. I will instead say the FTL drive is exploiting a form of space-time resonance, the type (in sound) that can break glass; and it takes the gravity of **at least** a red dwarf star to disrupt that resonance; because that gravity bends space-time, remember? So the resonance breaks due to that much (or more) space-time distortion. Disrupting the resonance is what drops us out of FTL; not the slowing down due to the star. [Answer] Establish FTL highways that need to be constructed (I don't mean physical roads or rails but some distortion in time and space or something - sci fi!!). While in theory they could go through a star system, they didn't for the reasons you mentioned. This is somewhat similar to real highways which also don't go through cities or only at a limited speed. Well, that's how they do it in my country at least. Radiation alone should be a problem for the inhabitants of the solar system. The advantage of this method would be that there still could be such paths to the planets, but at a different speed. You can make your spaceships pretty slow unless they are on one of those roads and avoid the problems that come with a FTL engine. [Answer] Do you want them to be able to jump to ANY star or just some specific stars? In the latter case, you have **Mass Effect's [mass relay](http://masseffect.wikia.com/wiki/Mass_Relay).** ## The basic rule is: You can only *"jump"* from relay to relay. Hence, you can't jump to a star system that doesn't have a relay built yet. This makes FTL not viable for "exploring" but once some colonies have been established in a system, they could start building their relay to be connected to the "relay network", so the FTL trading and massive inmigration may start. [Answer] Since everyone else is saying gravity, I will suggest **ELECTRICITY**. Make your FTL drive dependent on leveraging a [sun's magnetic field lines into a particle accelerator](https://www.nasa.gov/centers/goddard/solarsystem/2006_mag_recon.html). Similar to all the gravity-well suggestions except the ionized solar wind is the polarizing force that aims the ship away from a star during acceleration, and towards the other star during deceleration. It only works on the star, not a planet, because the star is the dominant magnetic field. At FTL speeds you can't stop halfway to visit a planet, it would be like a ball stopping in mid-air. [Answer] Some interpretations of Einstein's field equations allow for FTL by forming a "bubble" of curved space around a ship (check out the [Alcubierre](https://en.wikipedia.org/wiki/Alcubierre_drive) drive on Wikipedia). Forming such a bubble would require some exotic matter, which may not play nicely with particles of the solar wind, random bits of debris, or anything else you might encounter inside of the boundary shock of a solar system. Additionally, it isn't well understood what would happen to any matter that crosses the boundary of the bubble, as it would experience some awesome tidal forces, so you could reasonably assume whatever happens would be bad for all concerned. If your FTL technology is based on folding space or warp bubbles, these considerations could provide a very practical limitation on when and where you could safely use the tech. FTL is pretty exotic stuff, so it isn't at all unreasonable to think the limitation would be one of safety, either for the occupants of the ship, or the destination. [Answer] Perhaps your faster than light drive can go "through" objects or pass "through" their spatial coordinates without interacting with them. Thus you can't harm a planet or a star by hitting them. Instead you pass harmlessly through them like neutrinos. Thus people might say that an ship is "neutrinoized" when using FTL drive, and some of your characters might think that the ship and themselves are turned into neutrinos when the drive is on until someone explains what actually happens. Possibly the FTL drive is so fast and the mechanisms for turning it on and off are so slow that the shortest possible distance you can travel using it is one trillion miles (1,000,000,000,000 miles). The distance between one star and its closest neighbor star is usually about 5 light years or about thirty trillion (30,000,000,000,000) miles. So they aim their starship at the destination star and then turn on the FTL drive and emerge from the drive within a trillion miles of the star. But if their slower than light (STL) drive is fast enough to travel up to a trillion miles in a short enough time for story purposes then a ship on slower than light drive could destroy a planet by ramming it. So if the ship emerges from the drive too far away from the destination, they turn on the FTL drive again for the shortest possible time and travel about a trillion miles. This may take them to the other side of the destination sun. If they are still too far away from the destination planet, they travel back approximately a trillion miles. If they are still too far away from the destination planet, they try again. And sooner or later the variation in the distance traveled in the shortest possible FTL trip will enable the to comes out of FTL drive close enough to reach the destination in a short enough time using the slower than light drive. Or maybe the shortest FTL trip is always exactly 1,000,000,000,000 miles. Thus after they make the long interstellar trip they see how far they are from the destination planet. They calculate the surface of a sphere exactly 1,000,000,000,000 miles above low orbit around the planet. And they calculate the surface of a sphere exactly 1,000,000,000,000 miles from their present position. And maybe there will be positions where those two spheres intersect. If so they will make a FTL trip to one of those positions and then another one to low orbit around the destination planet and use their slower than light drive to match speeds and then land. Or maybe they will have to make one or more intermediate FTL trips 1,000,000,000,000 miles long zig zaging around to reach a position exactly 1,000,000,000,000 miles from low orbit around the destination planet. If you keep adjusting the parameters of the FTL drive and the STL drive you can make a trip across the galaxy take much less time than an interplanetary trip. But I kind of doubt you can make the STL drive slow enough that it will be impractical to devastate a planet by ramming it under the STL drive. The energy needed to match speed and direction of a planet orbiting around a different star with a different velocity than the star and planet of origin will make ramming with a starship on STL drive very dangerous. Perhaps the starship will be legally required to travel by FTL drive to a spot in empty interstellar space and match its intrinsic velocity to the velocity of the destination star and maybe even the orbital velocity of the destination planet before resuming the FTL trip. Thus any ship that stops its FTL drive in a solar system and has an unmatched velocity will be assumed to be hostile and the planetary defenses will be activated. [Answer] It requires a whole planet to launch the FTL drive, which makes the planet difficult to be used for anything else. To use the spaceship, first you go to that planet using conventional ways. There are armies and technicians from each fraction on that planet to make sure it won't be used as weapons. And there are not enough planets for each fraction to build their own. It's like why you don't go somewhere 1km away by air. Alternatively, the same device can be used to slow down an FTL object or change its path near the planet it is based on. [Answer] A solution from Larry Niven's *Known Space* universe is to have some form of life that lives in hyperspace and hangs out in gravity wells. Any ship that enters hyperspace too near a sun stands a good chance of getting eaten. [Answer] Not sure I fully understood all the other answers, so forgive me if I'm repeating someone. I suggest the achievable speed and/or the achievable acceleration is inversely proportional to the magnitude of the net gravitational attraction on the drive itself. Set the multiplier such that the point at which a conventional drive is faster is close enough for the conventional drive to be practical. [Answer] Hyperspace. Your FTL requires travel through a different dimensional space that does not interact with normal space. Once you drop out of it, no momentum is maintained, making using FTL un-weaponizable. Said hyperspace is also not a 1:1 mapping of normal space, and the minimal travel distance in hyperspace amounts to 35~70 or more AU. Meaning the smallest jump clears you from the Sun to Pluto or farther, making intra-system jumps unlikely. Due to how freaking huge space is, dropping out in the middle of an object is already near zero in probability, but you could also have dropping out of hyperspace clear any matter in its way, ala the Stargate woosh. [Answer] Use an [Alderson Drive](https://en.wikipedia.org/wiki/Alderson_drive) It opens existing wormholes at the ends of the Alderson Tramline (in the Pournelle and Niven Universe of Mote in God's Eye) and other books by different authors using the same concept. These wormholes only form away from the star, and between two nearby stars. Not all stars form tramlines, and some wormholes - notably the one in the book, end up being within the atmosphere of a Red Giant star. Travel between wormholes within a system is via standard reaction drives, so no FTL within a system, and once at a wormhole, it only links to the destination star, so you need to travel to the next wormhole in the destination star system if that is not your final system. Hence, travel takes months, but travel between star systems is instantaneous. [Answer] I wrote a short story a while ago where the FTL was based around space folds, which could only be done at Lagrange points. Essentially, the gravity-based drive could only cope with so many calculations, so you needed to be moving very slowly and in a point where the gravity from the two closest gravity sources would cancel each other out. It didn't allow for any speed in or out, as low speed was a prerequisite for the gravity drill to work. That takes care of your hypervelocity thing. This admittedly allowed for FTL from planet to planet, but you could handwave that hyperspace tunnels are only stable outside of systems, necessitating inter-system use - perhaps it's only safe to do from fringe to fringe of each system due to shallower gravity wells? [Answer] Imagine that there exists a background magnetic field across the galaxy. A result of traveling through a very large volume of space in a very short time via FTL drive; (whether warp drive or jump drive) Is an enormous electromagnetic potential is developed across the ships hull. If arriving to close to a star the ejected hydrogen nuclei or solar wind creates a conductive path for electrical discharge. And suddenly you have performed electrical discharge machining to drill a huge hole in the hull of the ship because you arrived too close to a star before bleeding off the electromagnetic potential acquired during travel. This idea also gives you some story bylines for finding shipwrecks just inside a solar system. [Answer] **Energy** No one mentioned it but in RL you needs a infinite amount of energy to achieve something with mass to reach LV that's main reason why FTL in RL is not possible. In fiction FTL can be possible but the amount of energy generated can be engouh to increase the mass of the ship (relative to the "still" sol) to a point anyone in earth frame rest can think of your ship as a massive star. This can pertubate the planets, asteroid's belts, Oort cloud coments and the sol orbit. These pertubations cannot be used per si as a weapon because those pertubations can needs decades to cause nasty effects like meteor storms, etc. But can be a issue enough to not jump from or to a habited star system. Also at this tech level vaporise a possible earth colliding comet can be trivial. Also jumping too near of a star can be dangerous for the ship because exiting from FTL to a system with every object (star, comet, planets) being hurled at your exit positions can creat a hazard also note it can pertubate those orbits enough to make impossible to accurate calculate a planet position before FTL jump. [Answer] I've seen two systems that came at this problem from different angles. The first is (I believe used in David Weber's [Honorverse](https://en.wikipedia.org/wiki/Honorverse)?) that **gravity wells from large objects (like stars and planets) *throw off the calculations*** required to make sure you come out at the proper place at the other end. In addition, stars have a lot of matter orbiting about them. If you miscalculate, its *unlikely* you could end up either inside the star, or some other bit of matter (planet, asteroid, etc), but it is possible, and essentially instant death. The better your computers and operators, the closer in you can safely get try to get, but diminishing returns on that effectively force *everyone* to warp to and from the *outskirts* of the star system, not directly inside it. The other one I've seen, featured in K.D. Wentworth and Eric Flint's [Jao Empire series](http://www.baen.com/categories/books-by-series-list/jao-empire-by-eric-flint-and-k-d-wentworth.html), is that **the stars themselves are required to travel FTL**. Each star essentially acts as a jumpgate, and you have to take (heavily-shielded) ships inside its photosphere in order to activate the FTL drives. That one's so distinctive, I'm not too sure how much you can borrow of it though. I suppose if you tweaked it a bit (eg: make it about the star's magnetic field or something, which would require approaching from a magnetic pole) [Answer] Gravity warps hyperspace, decreasing the distance between points in hyperspace, the more gravity on a region the further you have to travel in hyperspace. Making travel in system via hyperspace as show if not slower than real drives. I think i read about drives that work this way. [Answer] **Gravity** You can say, that, if you're to close to a planet, your ship is under the influence of the gravity of said planet and accelerating to light speed would throw the ship off the course to an degree, that the ship may even crash into an other planet, unable to slow down fast enough. [Answer] * For ships: Too many things which fly around in the solar system (Kuiper belt). * Why would an kinetic anit-planet weapon in a solar system profit from FTL? The planet is not going to jump away, and splitting a kinetic weapon into parts doesnt help the defender. That means that the only relevant value is the input of energy, which probably would be the limiting factor. Assuming that these are strategic weapons (on the uselessness of Planet destroyers: watch "The Lexx"), quickly hitting makes no sense. [Answer] Hmm. How about this system: FTL are done through creating directed space distortions. You create it, it explodes, creating a cylindrical space distortion, which carries a gravitation wave. This wave creates reality-free bubbles on a front of a wave because of cavitation, and within those bubbles ships travel. But problems is: 1) There's minimal size for usable distortions, if too small - it will not produce reality-cavitation bubbles, and minimal power level sends you at least lightyear away. 2) It eats a lot of energy. Ships can't do it on their own, requiring some sort of gate. Maybe, even planet-based. 3) Accuracy - bubbles are unpredictable, ship computer just hops into one it can detect, and in the end ship pops out within wide area at the end, which massively limits precision. 4) They are basically harmless on the recieving end, due to gravity wave dissipation within the same wide area. So, for these reasons, it's hard to directly weaponise from distance, and no slugfest. Too random, too costly. But slamming a planet through is possible, if you drag your distortion generator to your target. Or ypur planet to your target. It also makes such gates dangerous to place close to your own planets - if it's captured by enemy, they will basicaly get a cannon right under your nose. If they are planet based, they shoul be guarded like nuclear storages. Problem is, there's no explainable reason to stop cruise missles, but allow spaceships. But cruise missles at least can be detected and counter-measured, just as ships. Don't forget that FTL is not real, so apply your artistic license, but support imaginary physics with creative side-uses. **Whatever principle you decide to use, it will be more believable if unusual technology applied not only to FTL travel, but also to other areas of life. This part makes them more believable than any amounts of physical terms - if believability is your target.** [Answer] In a story I am trying to write ,gravity from stellar objects in normal space causes the dimensions of hyper space to constrict exponentially as you approach the area in hyper space that corresponds to the area in normal space where large gravity wells exist. So just popping out of hyper space and entering orbit around the Earth would be like trying to park a semi truck in a parking garage made for small economy cars. To look at it another way, as normal space expands into hyper space and the universe expands ,gravity from objects in normal space causes hyper space to be nearly non existent in the areas close to large objects like stars or black holes . I hope this gives you some ideas. [Answer] Perhaps telemitry computers do not function at light speed. You may be looking at the nearest star, but it's data that is light years away at best... orbit inside the star's system is not up to date and while larger bodies can be accounted for, you cannot account for the like of asteroids, commets, OTHER SPACE TRAFFIC which is data which is at best years out of sync when you make your jump calaculation. Best to make the jump to the edge of the gravety well and use sublight to manage the interior. As for FTL in systems, it would be like taking a 747 from Baltimore to Washington D.C. Doable, yes... fuel-economical and profitable? Nope. To say nothing of the other craft in system which are zipping around and might get in the way. It could even allow you to jump from inside the system to a nearby system, as the stuff in the way is easier to calculate a viable window. But inbound traffic must stop at the boarder's edge. This could be stopped by indicators which are set up to prevent the catastrophy of an offensive attack or a busted nav system. [Answer] Cheap and effective FAD systems (FTL Area Denial) Any target worth protecting has one, and keeps it turned on unless they have a good reason to do otherwise. Anything using standard FTL drives entering the exclusion zone gets dragged back to sublight speeds in a decidedly violent manner. Note that this won't 100% prevent using FTL in-system, but you'd have to get the people in your flightpath to let you through, which they would likely be disinclined to do. [Answer] I don't think you can, but not because of science but because of logic. Let A and B be planets in the same solar system, and C be the nearest neighboring star in another solar system. If I can use FTL travel to travel from A -> C, I can use FTL to go from C -> B. You could set it up such that an FTL trip A->C->B takes longer than a non-FTL trip A->B, but then you're constraining FTL in your world to be pretty slow. One way you could address this would be for the original departure location to be temporarily "tainted" somehow such that FTL drives don't work in the vicinity for some period of time, but that would probably have a lot of side effects that you'd need to account for (e.g. if I can't travel to B for 5 years after an FTL trip from A->C because my departure affected the region, then *no one* can travel to either A or B via FTL for that period either). [Answer] This is my first attempt at an answer, so I apologize in advance if I missed a guideline. **Everyone so far has had some fantastic insight!** I'll contribute what I know (which isn't much) and see where it goes. * FTL travel is still a disputed area of science. Shortly after Einstein's Theory of Relativity, the early scientific consensus was that light speed as a "barrier." Anything capable of traveling faster than light is already doing so. And everything slower than light is (theoretically) doomed to stay there. But this rule only applies to matter. * I understand the popular opinion that the energy requirement to travel FTL is really high, but it IS within our reach. About 10 years ago, some guy actually got a wind-powered vehicle to travel FASTER than the speed the wind was blowing. And he did it on land! (It would've been easier with a properly sized hydrofoil on a sail boat.) [Read the story if you wish.](https://phys.org/news/2010-06-wind-powered-car-faster.html/) * If we ever make contact with intelligent alien life, there's no guarantee that they'll be based on Carbon, or share our environment. For all we know, they could be electrical, living on a planet with no atmosphere at all, and be incapable of leaving the planet. Kind of like a plasma ball. So let our trading partners supply the energy. And whatever we're using as a delivery vehicle should be a drone! It eliminates the need for life support, and drones don't care if they travel through time! Regardless of what you decide, let me know when it's done! I'll buy the first copy. ]

[Question] [ Let's say that Vegetarianism is banned in my country and meat eating is mandatory. The technology is modern. Stuff like Tofu, Quorn and other things that can make vegetarianism more popular are banned and considered contraband drugs. The punishments are the following (but differ by region, sometimes being harsher): * practicing vegetarianism on purpose - flogging, imprisonment, brainwashing, death * practicing veganism (no milk and eggs either) - life imprisonment, brainwashing, death * converting others to vegetarianism/veganism - death * forcing others to be vegetarian/vegan (especially children) - death * tofu contraband - death My question is how to enforce the ban effectively, both at home and in restaurants. Technology is *modern*, so no magic survelliance nanobots. Do I have to have a "food police" which comes to various homes once in a week or so and inspects the dinner (of course including taste control, so nothing is left for the people to be controlled)? Survelliance cameras in restaurants connected to police stations? Only allowing restaurants to be located in specially constructed buildings with meat broth bombs? Having chemical sensors in restaurants which can smell even the lowest concentrations of tofu? NOTE: The consumption of vegetables is NOT banned, it is even encouraged to eat some pesky green stuff with your lamb chops. For breakfast, you can eat stuff like salami or sausages. For the purposes of this question, "vegetarianism" means intentional abstention from meat for more than 3 days. [Answer] Simple: **Mandatory public meat-eating.** A somewhat related [historical example](https://books.google.com/books?id=nQ0yAQAAQBAJ&pg=PA2&lpg=PA2&dq=pork+eating+spain+conversos&source=bl&ots=UEfLSYFVjp&sig=29eWLuNoAovcDzmKGo01DssESWg&hl=en&sa=X&ved=0CFEQ6AEwCWoVChMI69nFnKX-xwIVCVcUCh0_yQ2m#v=onepage&q=pork%20eating%20spain%20conversos&f=false) occurred in Spain from the 16th century onwards. The Jewish and Muslim religions were banned, and eating of pork was a common way to demonstrate that one was an authentic Christian. [Answer] ## The House Vegetarian Activities Committee Many answers have been given, most of them pretty practical and uninvasive (considering). But practical and uninvasive is not what governments are going for with these kinds of laws. Sure you can instute mandatory public meat eating, but that's like making a communist salute the flag. They'll eat the meatloaf to escape detection, but inside they're still deeply, morally corrupt. **The question is not whether they're behaving like vegetarians, but whether they are thinking like vegetarians.** What we need to do, is get at at the heart of the matter. Root out these vegetarians. Investigate every inch of their lives, until the weight of evidence can be used to force them to admit their wicked ideals. Then, force them to give up all their vegetarian comrades, that they met at their surreptitious soy buffets, and keep going until every last seitan shyster is in chains. Yes, we may have to relax some of those civil liberties that the intellectuals are so keen on, but when it's those civil liberties that the Vegetarians are using to erode the moral fiber of our proud carnivorous nation, I say that's a risk worth taking. [Answer] How do you tell if a person is vegetarian? **Test the microbiota.** The population of microbies in the gut is a function of diet, drug treatments, etc.(See, for instance, [this article.](http://www.nature.com/nature/journal/v488/n7410/full/nature11319.html)) The procedure would only require a stool sample, from where the DNA would be extracted and analysed. Given the volumes you have to process, the whole procedure can be fully automated. The lab machines can fit in a few large rooms scattered around the city, and the data would be sent to central supercomputers (probably the most expensive part). Bottlenecks are easily dealt with, the samples can be stored frozen for very long periods of time, and you actually need very little material to perform the actual experiment. Note that you cannot fool this method by just eating some meat before getting tested, you actually have to incorporate it in your diet to affect the bacteria population. You are actually testing the person's lifestyle, not their last meal. As a bonus, for the same cost, you can make a good sampling of the population's health and catch early most of the colon cancers and other gut diseases. (If you are interested in this approach, I can add more the details.) [Answer] **Make eating a public activity** As @royal-canadian-bandit suggested, regular public meat eating events would help to spot meat-avoiding people. But what if all eating was a mandatory public activity? Let's create large community eating areas where people consume their meals. The meals are made by government cooks under permanent surveillance of food police agents. Someone doesn't show up? Food police will investigate. Someone is ill? Food police will take care and send a doctor to cure them and provide a healthy meat diet. Need to travel? Food police will assign you temporary community food areas. You are not eating enough? You surely need some guidance. Food police will provide you a mentor staying at your side for several days, keeping you from any troubles with your food choices... [Answer] Make meat a required product to add to all produced food products. Only needs to be a small quantity, so you can just mix it in the spice-mixes that are used in the factories. And second, require fields of crops to be dusted with meat-products the same way they are dusted with pesticides and the like. That'll make even regular veggies bought from a market non-vegetarian. Then you'll only need to crack down on people who grow all their own food, but that should be quite doable considering how big a farm for even sustaining a small family is. [Answer] With modern technology, the government can track what people are buying. One method to do that is to create a database of all purchases made with credit cards or checks. This way you can see if someone never buys meat products. If people use cash, the government can also enforce a mandatory **customer card** (mix between ID card and loyalty card) policy. The citizens will have to present this card for all food purchases, in shops and restaurants. The problem with this method is that people could buy meat and then throw it away. A solution would be to ask restaurants to take note if someone didn't eat the meat products in their plates, and signal it when editing the bill (this plus the customer card will immediately give you the names of the picky eater). To accelerate the process and be sure people too poor to eat out won't stay off the grid, restaurants and shops around the country could sell small meat balls or chunks of jerky at the counter. The cashiers would validate the sale only after the customer put it in their mouth. If the *meat bits* are cheap enough the government can make **weekly public meat-eating** mandatory to all citizens. The advantage of these solutions is that they won't cost too much. **Data mining** will give you lists of potential vegetarian (people who only buy the legal minimum amount of meat products), and most of the policing part will be done by the citizens themselves (cashiers, waiters, etc.). **EDIT :** For the **contraband** part, you can find inspiration in the real world. Encourage people to denounce their neighbors, and remember that good detectives are more useful for the *War on tofu* than random search in the street. Don't worry too much if you still have a few smugglers, they'll make excellent **skapegoats** in case of economic crisis of epidemy. [Answer] **Random Testing** People could be selected to produce stool samples that would be examined for animal tissue. There could be random testing along with more targeted testing of people the authorities were suspicious of. You'd obviously have to give people enough time to "produce the goods" but not enough that they could have digested meat in the meantime. [Answer] Encourage members of the public to report suspected vegetarians to the authorities, and have a strong under cover police force. Eating is often a social occasion, and out of necessity many people eat in view of others, e.g. at a workplace. People could notice a friend, colleague or family member consistently not eating meat and report them to the authorities. Make it a crime to fail to report a suspected vegetarian. Use a propaganda campaign to convince the public of the dangers of vegetarianism and therefore the need to report. [Answer] Spacelizard had a point in monitoring what comes in. For the sake of keeping it dry I will not repeat his answer. Now to monitor what comes out: a [smart toilet](http://techcrunch.com/2009/04/01/japanese-toilet-analyzes-stool-beams-results-to-cell-phones-via-personalized-urls/) that beams information to your celluar device. [(Another)](http://www.medicaldaily.com/japanese-toilet-app-tracks-and-analyzes-bowel-movements-its-easily-hacked-249295) This would be a good addition to check what comes in is also what comes out. This could be complemented with having barcodes on the trash bags. This is in no way foolproof, and creative people will always exist. But it would make it a lot more difficult. [Answer] 1. You check their garbage. 2. You go round their house with a warrant and demand to see what they have in the kitchen. This is exactly what the Spanish Inquisition did to Jews and Muslims who had failed to convert to Christianity, or those who ("worse") had publicly converted (because they had been threatened with violence if they did not) but continued to practice their original religion in private. Any suspected Jewish or Muslim household that received a visit from the Spanish inquisition better have some ham (a ubiquitous food in Spain) in the cupboard, otherwise they would be taken away for torturing. <http://vanorabennett.com/blog/how-the-inquisition-found-secret-jews-in-spain-by-sniffing-their-kitchen-smells-and-rooting-through-their-garbage/> <https://en.wikipedia.org/wiki/Spanish_Inquisition> [Answer] First, you need a police state. Control every source of food, and tell people what they need to eat. Make growing food yourself illegal, and make selling it illegal. Urine tests? [Answer] Believe it or not, the simplest and most effective answer is : DO NOTHING. Simply continue the status quo of modern industrial agriculture.. if possible, provide more incentives for using more fertilizers and pesticides. The soils of the world are already on a terminal fertility decline.. in good time they will degrade even further. A point will be reached when it will no longer be possible to grow vegetables, fruits, nuts, foodgrains etc as those require higher fertility levels that will no longer exist. The only thing that'll grow now will be short rough grass and other inedible shrubs. Only grazing animals will be able to feed on that, and so the only people who will be able to survive any further will be the ones who can eat meat. The vegetarians will all have to convert or die. Or they might adapt to eating grass, but maybe you can then declare them to be sub-human and start eating them too. Of course, this will also bring in encroaching desertification and after a limited honeymoon period of global meat-only-eating, the soils will degrade to levels that won't even support the most basic forms of grass. The grazing animals population will collapse and following them so will the human population. Sea food will have already died off a long time ago, btw, due to the pesticides runoff and overfishing. The global oxygen supply by that time will also have reduced to levels where the remaining people won't be in any state to do much. But thats ok.. at least we will have achieved the objective stated if only for a limited time period. [Answer] All vegetables are genetically modified to produce a poison and all livestock are genetically modified to produce the antidote. You then need to eat minimum amount of meat to prevent getting ill and eventually dying. [Answer] If I was the dictator attempting to enforce this I'd do it with three forces. The first would be secret police that attempted to entrap citizens by trying to sell them tofu in dark allies to create fear and distrust in the vegetarian community. The second would be propaganda declaring how evil Tofu is (maybe say it's made of people or causes cancer). The third would be monthly required blood tests checking for markers only found in meat for the citizens. [Answer] How it is enforced is going to depend on why such a ban was enacted. If the ban is religious based I would expect some sort of inquisition type body might be involved, perhaps with the law primarily being used to punish those do not support the church leaders. If the law is enacted because all food animals are being injected with some drug or other control agent that is transferred through consumption, then I would think that regular testing for levels of the agent in the blood or tissues. With those refusing rounded up and put in control camps. Laws like this dont get put in place with our either a good reason, or a evil one. How it is enforced will depend on why it was enacted in the first place. Some of the most evil punishments have been devised by men attempting to bring out the good in men and drive out the evil. So if it is intended to be for the good I Would expect the enforcement to be more heavy handed, where evil plots are going to have more subtle coercion as primary enforcement, with more harsh penalties reserved for the holdouts creating the most danger of disrupting the plot. [Answer] Required cholesterol testing, call it "Boosting Biometrics". Generically speaking, the total cholesterol and LDL can provide insight into what the person eats. Studies vary but generally show 10-30% lower numbers for vegetarians than meat-eaters. That's not a perfect test: 1. genetics could account for X percent difference (I have not found any studies citing a percent range). 2. a vegetarian could eat primarily processed foods (instead of fresh fruit and veggies) and thus gain the cholesterol numbers needed to pass as a meat eater. But, perhaps that's one approach that people in this hypothetical country could take to avoid a flogging. I could imagine that this hypothetical country is proud of it's meat-eating, but clueless about the high rates of coronary artery disease, not recognizing the relationship. [Answer] Subsidize the price of meat products and increase the price of vegetarian sources of protein (beans and nuts, for example). Basically, make it too expensive to be vegetarian and healthy. Place restrictions on home gardening and farming of vegetables to make it difficult for people to live off their own produce. Rather than making it illegal, require gardeners to register for a permit and force them to sell all of what they produce to the state (sort of how liquor laws work in some US states). [Answer] Turn everybody into zombies (because the zombie virus is, of course, real). Zombies don't eat silly plant matter, zombies like meat. [Answer] If you want to go the creepy route: * No crops are to be grown in dirt as all farmland is reserved for livestock * All vegetables have been engineered to be grown sangoponically in a diluted blood solution in greenhouses adjacent to the slaughterhouses. This ensures that all veggies are also meat products! Then you can have neighbours turning on neighbours for suspicion of growing organic tomatoes out back! [Answer] Create a system [ call it "**BigBrotherBook**" ], that: * Allows everyone to upload photos of themselves eating. * Has software agents analyze the uploaded data on a continual basis to see what people are doing So the final element is to have that system create reports on the eating habits of everyone. It can even automatically post such reports directly to public notice boards, the police or most effectively to the people concerned. Each persons "wall" or some such could contain a "**likes meat**" icon indicating their meat eating status. Having implemented such a system, a government can then not just pass appropriate legislation, but have some chance of enforcing it. Obviously such as system is readily modified to enforce compliance to any other arbitrary behavior by a totalitarian state. Equally obviously, no freedom desiring society would allow "**BigBrotherBook**" to be created ... [Answer] A ban is too forceful for a population to accept totally. What you want to do is alter behaviour! Religion is a powerful motivator and has historically made people do all kinds of things and continues to this day. For a great example. [Check out what this Brazilian Pastor told his congragation!](http://obnoxioustelevision.com/2013/01/31/pastor-in-brazil-convinced-his-members-his-sperm-was-holy-milk-has-been-arrested/) [Answer] Drugs everywhere. drugs that make people addicted to meat. eazy peazy Add those drugs everywhere, cigarettes, cultivations,farms, forests... Maybe build machines that release this drug as gas on public zones 24h/7d. anyway, executions are incredibly expensive three times as much than keeping someone in jail for from birth to death. your world would go to famine and eventually fall with all the money spent on killing vegetarians or vegans. To avoid an istanteous economy fall, the drug has to automatically kill people if they don't eat meat for more than 3 days cause even when drugged people with a strong morality won't sell their souls, specially empaths which are almost always only vegans or vegetarian people. Anyway, great part of the human population will die anyway cause they don't eat meat for health reasons and forcing them to do so would be exactly like telling them to suicide. Then another great part of humanity will die too for not being able to afford buying meat..... you'd expect to have a world with only 2-3 billion people instead of 7 billions But anyway, meat consumation is so destructive that the economy will be destroyed anyway sooner or later. ]

[Question] [ You installed a strange browser you found in the deep web that works similar to any other. You soon discover something really amazing. That browser shows the state of any web page or online app 5 seconds in the future. You make some tests. WhatsApp and similar things you can interact with quickly become a mess, changing constantly as soon as you change your mind while you read your future responses or try to write. It's practically unusable. Betting pages work as expected, seeing the results 5 seconds before the rest. Poker and similar gives you an obvious advantage but only 5 seconds doesn't grant you the victory. E-sports don't work on browsers, so they are discarded. You really want to became really rich. How do you do it? [Answer] **Iterate.** Set up a webcam pointed at your computer screen with the browser open, use another computer to watch the webcam through another instance of the browser, set up another webcam and another computer with another instance of the browser... Each additional computer that you add to the chain will give you a further 5 seconds insight into the future. With 60 camera/computer/browsers in a chain, you have five minutes of insight into the future - easily enough to place bets on races, poker, games of chance. You'll even be able to see when suspicion is aroused about your activities sufficiently in advance to avert it. The more money you make, the easier it'll be for you to create an even bigger machine with more layers and more "foresight" - you should then be able to see what oilfields yield fresh reserves, where archaeological finds yield hoards of gold jewels, artifacts (and get there first, at your leisure) you'd see future technology (and the technical plans/specs on Wikipedia or future equivalent) and be able to invent it first. You could save the world by discovering the secrets of cold fusion. Find out what's in Dr. Pepper. You'd be able to find the secret of immortality (at least long life and cell repair) and graft any convenient physical and mental abilities onto yourself. You' could create a high-tech self-repairing army to protect you and do your bidding. You'd see what political strategies would lead you to become the president/prime minister/premiere of your chosen country - then what strategies would lead to your becoming ruler of the world. You'd discover time travel - go back to just after when the browser was created, kill the creators. # So, to sum up: * You rule the world. * You own it. * You're immortal. * You can predict your enemies strategies *before they were even born*. * The world's resources are at your disposal to do with as you will - to expand off-planet, or to parallel worlds (if such exist - you'd know). * No living person can do what you do and no one knows how you did it - you have no serious rivals and no peers. * You now know exactly what happened on the grassy knoll on that fateful day and what's up with area 51. [Answer] Assuming that the web browser is compatible with modern web standards... 1. Get an account with a web-based [electronic stock trading platform](https://en.wikipedia.org/wiki/Electronic_trading_platform), for example, [E\*Trade](https://en.wikipedia.org/wiki/E-Trade) or [TD Ameritrade](https://en.wikipedia.org/wiki/TD_Ameritrade). 2. Use your 5 seconds insight to buy low and sell high. 3. Enjoy your filthy lucre. [Answer] Crack any password, ever. Any problem (and there are a LOT) that is hard to solve but easy to verify, and be solved instantly by being able to look into the future. For a simple example: cracking a combination padlock. 1. Create a simple website, with a form, where you type in a number, click submit, and it displays it back to you. 2. Make a plan: You will open that page. If it is blank, type 0001 and submit. If it shows a number, try the padlock; if it opens, type that number in and submit. If the padlock doesn't open, add 1 to the number, and submit it. 3. The only stable outcome is, that the browser view from 5 seconds in the future, will show you the correct combination! There are a HUGE number of extremely important questions in cryptography, physics, biology, etc etc. that can be checked in a few seconds, but would take centuries to try every possible combination. We're talking world changing stuff here, depending on the intelligence of the team you have working on it... you could do practically anything. But, you just want money. So, here's what you do: Open a bank account somewhere secure (swiss? caymans? do a bit of research, first). Then go to the online banking portals of other banks. Use your magic password cracking password to open the account of Warren Buffet / Bill Gates / Donald Trump / etc. Transfer their money to you. You are now rich! Just make sure you get all of it - don't want them coming after you! ;) [Answer] Get an augmented reality headset, and install a custom firmware on it, which contains the browser open to a page that shows the incoming feed from the camera on the headset. Project this image in front of one (or both, as a sort of overlay) of your eyes. You now have the ability to constantly see 5 seconds in the future. You can call every coin flip. Tell what people are going to do before they do it. You have inhuman reflexes; you can dodge bullets! Maybe you should become a superhero? But, the question is how to make money, which is not difficult: Walk into a casino, and start playing baccarat. Or blackjack. Or even the slot machines - some of them use the player pressing a button as the random input to determine the prize, and your glasses let you see exactly when to push it. You know what every die will roll before it hits the table, shouldn't be hard to make a buck or two from that! [Answer] Just sell it. In speed trading seconds are highly valuable. To a company engaged in that the fair market value of your browser would have to be tens if not hundreds of millions. Full five minutes of advance time on competition would be pretty much license to print money. You would have to figure out a way to filter out the effects of your own trades on the accuracy of the prediction but those guys could pull it off. [Answer] You say too much quickly "Poker and similar gives you an obvious advantage but only 5 seconds doesn't grant you the victory." I suggest to play specifically Omaha's variety and not Texas Holdem, acting in the lapse between you know the cards the crupier shows and your time to play. --- **How the game works?** You receive your cards. Then there are four streets to bet: 1. Preflop: No cards at the table. You only bet with your cards. 2. Flop: The crupier shows three cards and there is a new bet. 3. Turn: The crupier shows the fourth card and there is a new bet. 4. River: The crupier shows the fifth card and ther is the final bet. --- **Why Omaha's variety?** At texas holdem you receive two cards. At omaha four. Common best hands on TH are a top pair, while at omaha you frequently have as best hand *the nut* (the best posible hand on table). So at TH you may fall beting in flop street while turn or river card make you loose the money. --- **How to profit it?** You need to play at high tables with position. That means you are the last player on the hand playing, to know crupier's cards. Then you just need to bet when you flop the nut or a good flop (note the nut means you win for sure). This is specially important at first street as at Omaha you can frequently flop the nut, but it would be valid also for further streets. So you will allways play cards that flop a good hand and also bet on turn (where money use also to flow in this variety). --- **Paradox** The paradox is the server would show your past bets, and so it should be a bit magic showing two paralel time lines and not only the main one where it knows your bet (knowing yourself crupier's cards). [Answer] ## Scalping [Ticket scalping](https://en.wikipedia.org/wiki/Ticket_resale) is the process of buying additional tickets to resell at a profit for events. Most of these events use a platform like Ticketmaster.com and the sale only starts on a specific day and time. Using your browser you can go to the release of a highly desired event and purchase a number of valuable tickets. Since these high profile shows sell out within days if not hours your 5 second lead time should help purchase the tickets before legitimate users. Afterwards you can resell on things like Facebook market place. ## ebay You can start ebay reselling. It is easy enough to discover the true value of a product with some googling. Make a list of the really good deals and then shortly after a product closes bidding you have 5 seconds to place the lowest possible winning bid. After the purchase you put it back up on the internet with a better value so you can profit from the difference. [Answer] Does the browser have magic prophecy powers, or just your specific installation? Because the first would mean that it's unique, and others have given pretty good answers about how you could use that. If you can just download it to any and as many machines as you want, you end up in a vastly different universe, and I'd like to go open up that angle a bit, because I think you need to either consider this or come up with a very good reason as to why it's not used by everyone. This thing *will* spread, because it's far too useful, too interesting, and too good of an opportunity to make money for it to stay secret for very long. In that scenario, it's only a matter of time until many, most, and all other people use it and have the same advantage, resulting in nobody having a real advantage anymore, but being forced to use this browser. Race betting etc. would break down, because nobody would offer these bets if they know that betters *know* the winner. In stock trading, you'd end up in a similar state to reality, where people fight about microseconds again after everyone has that 5 second advantage. I'd go so far as to say that in this scenario, you actually could not make much money with this, unless you are one of the early adopters, or you get very, very creative. I could imagine scammers using this in some convoluted "bet on a coin toss while secretly glancing at the browser that shows me a webcam image of the result" scheme, but other than that there's not much room for getting rich quick. Except for one: *you* have control over the browser's functionality somehow, and can charge people for using it - provided nobody can reverse engineer it and create an open source version or something. [Answer] Register as a bookmaker on one of the online gambling websites which takes bets on in-play sporting events. I'm afraid I can't remember the name of the website but I'm sure some googling will find it (from outside of a firewall preventing access to gambling website). It allows you to make bets but also take bets. So, you can lodge a sum of money with them and you can take bets on the outcomes of events from other gamblers. For example, someone wishes to bet 5 dollars and 2/1 on the outcome of a horse race, if you have 10 dollars in your account (to cover the payout), you can "back" that bet. If the horse doesn't win, you keep the 5 dollars bet that the gambler placed. The specific site I saw demonstrated allowed you to place and back bets on horse races right up until the end of the race and as the winner seemed to become clear, the odds on the winning horse would shorten considerably and the others would lengthen considerably. Now, if you had a way to know when something unusual happened, i.e. the lead horse falls just seconds before the finish line, you could financially "clean up". [Answer] If you just want to have fun and make some (but not shittons) of money, play online multiplayer video game competition. 5 seconds will guarantee you can eliminate any and all opponents with ease. ]

[Question] [ This relates to a world in which there is **no magic** and only medieval technology. The ruling and religious classes want to convince the general populace that magic exists. For example a sword-smith has been tasked with making a 'magical' sword that can only be drawn by 'the chosen one'. Of course there is to be a secret mechanism that only those in the know can operate. **The problems** The sword has to be a top quality sword that is forged by standard methods before inserting in the stone. The stone has to be real stone. It can be shaped using medieval tools but should be heavy enough so that it can't easily be moved. The sword must fit snugly. The mechanism for releasing the sword must be very difficult to discover. Nothing so obvious as pressing a simple foot pedal. A circle of six-foot radius is marked on the floor around the stone. Only one person is allowed in the circle at a time. There are guards to prevent damage to the stone or sword but anyone whether commoner or not must be allowed to try. They can examine the sword and the stone carefully before trying, and they have three attempts each. The guards will only intervene to prevent damage or more than one person at once entering the circle. The chosen one should not be allowed to try too soon. There must be many failures first to 'prove' it is magic. **Question** How can a sword-smith use medieval technology to simulate a magical sword in the stone that can only be released (or put back) by someone who knows the secret? ***No actual magic is allowed.*** **Note** There is some flexibility about the locale and the shape of the sword. I imagined something like the following but if it invalidates an *existing* answer I won't make the picture a factor when choosing. Add armed guards and possibly a large pavilion-tent to protect from the weather. [](https://i.stack.imgur.com/lkA8k.png) [Answer] Requirements: * One large hollow rock * One dwarf * One large pair of pliers * One tunnel * One loud voiced announcer of who is about to try to pull the sword out Tunnel under the rock for your dwarf to get access, make sure he knows the name of the eligible person to release the sword for when the loud voiced announcer calls it out. All you need now is a mechanism for holding the sword in place while the dwarf is off duty. > > “Nah, someone pulled a sword out of a stone,” said Nobby. > > “How’d he know it was in there, then?” Colon demanded. > > “It...it was sticking out, wasn’t it?” > > “Where anyone could’ve grabbed it? In this town?” > > “Only the rightful king could do it, see,” said Nobby. > > “Oh, right,” said Colon. “I understand. Oh, yes. So what you’re saying is, someone’d decided who the rightful king was before he pulled it out? Sounds like a fix to me. Prob’ly someone had a fake hollow stone and some dwarf inside hanging on the other end with a pair of pliers until the right guy came along—” > > *Men at Arms, Terry Pratchett*. > > > [Answer] **'Lock' the blade in place** Give the sword blade a fuller, the groove used to lighten some blades, and end it before the tip of the blade. It can then be inserted into a well crafted, close fitting, slot in the stone and a 'key' used to fit into, and interfere with, the fuller holding the blade in place in the slot. Inside the stone there needs to be some mechanism to release the key holding the blade. In medieval times they had crossbows with heavy draw weights held by a 'nut and lever' mechanism. A modified version of this could be used, with a remote cable based release, to allow 'selective' drawing of the sword. Due to the strength and design of the locking mechanism no matter what force is applied the locked blade will not come free, actually the harder you pull the stronger the locking force. It could even be made to self reset so that if the new King replaces the blade it again locks into place and again no-one else can remove the sword until the 'One True King'(TM) makes a second attempt. [Answer] ***Seal the sword in limestone*** Limestone dissolves in acid, which medieval peasants likely will not know. Fortunately our sword-puller does. Via some mechanism or his own doing, vinegar can be poured onto the limestone to dissolve it and weaken the hold on the limestone enough to wrench the sword free. It will bubble, however, so the limestone may need to be below a layer of decorative stone. As some display they may take a swig then pour it onto the sword. Or maybe trigger some hidden pipe below the surface. **Edit**: The dissolving reaction will not remove all of the stone, only enough to weaken its grip on the sword. [Answer] Forge a blade with a very slight reverse taper, so that it's ever-so-slightly wider at the tip than at the hilt. To the casual eye, the blade should appear straight and constant width, but should be just enough wider at the tip for your blade trap to hold it in place. Now, choose a stone with a very rough texture. The reason for this is you're going to split the stone in two, preferably in an uneven and non-obvious pattern, and you don't want the seam to be noticeable. Inside the split, carve your grooves for the blade. You'll need to be very precise as the sword should fit very snugly into the grooves. Finally, you will need to sand off a very thin layer on the cut side of one or both halves of the stone, so that they lean towards each other, applying pressure on both sides and trapping the tapered blade between them. [](https://i.stack.imgur.com/nol4R.png) Now the trick: In order to remove the sword from the stone, you will need to place one foot on each half of the stone and push them apart. If they are large and heavy enough, the stones should barely need to move to release the pressure. To the untrained eye, it will seem that your arms are doing the work of pulling the sword upward, but in reality, it is your legs pushing the stone halves apart that free the blade to be easily drawn. To discourage other people from mimicking your stance, your "king" should be wearing a robe that covers his feet, and the stone should have naturally comfortable obvious footholds that are both on the same half, so that people will not think not to use those but instead must stand in a less obvious and less comfortable position in order to push the stones apart. As with any good "magic" trick, some practice may be required to make the act seem convincing. A little showmanship and sleight of hand (or foot) goes a long way if you know what you're doing. [Answer] The sword looks like this: [](https://i.stack.imgur.com/bvvR3.jpg) The parrying hooks can be inserted below the stone's surface, where they lock into whatever locking mechanism you desire. Thus, anyone simply pulling on the handle will be unable to move the sword. Only the correct sequence of movements, such as pushing or turning the sword, can then release the lock, allowing the blade to be pulled out. With some practice, these movements could be performed such that they seem natural to observers. Alternatively, with the right “ritual instructions“, not even the Chosen One needs to know about the trick. One minor disadvantage though: The stone cannot fit perfectly to the blade, as some space must be allowed for the parrying hooks. However, this can easily be explained by saying that obviously these grooves were made by the same hooks when the sword was pushed into the stone in the first place. Even better: This mechanism can be made fully reusable, establishing a tradition of choosing the royal successor this way over multiple generations. [Answer] The stone has only to be the cover of a tub filled with a [dilatant](https://en.wikipedia.org/wiki/Dilatant) liquid. > > A dilatant (dī-ˈlā-tᵊnt) (also termed shear thickening) material is one in which viscosity increases with the rate of shear strain. Such a shear thickening fluid, also known by the initialism STF, is an example of a non-Newtonian fluid. This behaviour is usually not observed in pure materials, but can occur in suspensions. > > > An example of dilatant is [oobleck](https://en.wikipedia.org/wiki/Non-Newtonian_fluid#Oobleck), a mixture of water and starch: > > A person may walk on a large tub of oobleck without sinking due to its shear thickening properties, as long as the individual moves quickly enough to provide enough force with each step to cause the thickening. > > > The faster the candidate will try to pull out the sword, the more the liquid will hold it in place. Just give the surface of the blade adequate roughness. Just instruct the chosen one to sloooowly pull out the sword. "Patience is the key!" Starch was a [luxury good in middle age](http://www.oldandinteresting.com/laundry-starch-history.aspx), used for starching clothes. Since you are going to pick a king, I see no issues in using a luxury good. [Answer] Make the platform that people stand on while trying to pull the sword a slight rocker. That is, while people stand on it, it tilts forward (by a millimeter or two), pressing against the sword and locking it (either by pure friction, or by a mechanism with parrying hooks like in Surprisers answer). Now of course, the guards are standing on the platform as well, making sure that even if a light weight child tries to pull, the sword is fixed. The future king will command the guards back, to the other side of the plaform. This will make it tilt back for a millimeter and release the sword. [Answer] A different idea. There is a release mechanism embedded in the sword hilt. It basically has a hook that comes out from the side of the blade of the sword, blocking it inside the stone, and which can be triggered somehow. Using a trigger is too risky: people could notice it and even realize that using it they can extract the sword. But it could use a kind of lock. I have two proposals * The Chosen has a ring that can act as a key: it has an opportunely shaped extrusion that can be inserted in a lock inside the hint, which allows to release the hook that forces the sword inside the stone * The Chosen has a ring made of magnetic iron. The mechanism in the hint has a kind of cavity with a metal rod, which is is attracted and moved upward, this way unlocking the hook. This last one is probably less suitable, beacuse the mechanism would need to be light in order to allow for the magnetic ring to attract the iron, but in this case it could be too fragile and easy to break if enough force is used to pull the sword Or, if you like a less serious plot twist (even if it was explicitely forbidden by the OP): the sword is in reality a screw, and the Chosen is the only one who knows that he hasn't to pull the sword, but only unscrew it... :) [Answer] The sword is placed in a scabbard. At the bottom of the scabbard, there is a spring loaded push pin lock - when the sword is pushed all the way down, it pushes the pin back until it reaches a hole in the sword, then it springs back and locks the blade in the scabbard. The scabbard has a thread on the outside. You pour a large concrete block or you pick a large rock and you drill a threaded hole. Concrete might be easier since you can create a metal jacket that you can set in the concrete. You tighten the scabbard into the rock. Threaded fasteners were unknown in the medieval world, nobody would think to rotate the sword, they'll all try to pull it out. Whoever is rigging the selection can reinforce the notion that the sword is meant to be pulled out by spreading rumors among the populous: "Surely lord Clegane will be the next king! He is so strong he'll pull it out with one hand!" "Lord John's servant told my wife's aunt the lord is drinking bull's blood. His witch told him it will give him the strength to pull the sword out and become king!" Then reinforce it some more with some official announcements. Have the criers announce: "Thou who **pulls** the sword out by his bare hands shall have the strength to be king!" Give this a few months to work, then announce the contest is open. Have the soldiers overseeing the line of candidates give the following instructions to each man: "Hurry up peasant! I don't have all day! You know the rules - you have 3 pulls - hurry up now, there are 100 more like you waiting!" Feeling rushed and excited, the peasants have no change. Then you give some of the dumber aristocrats a go - again manipulating them to use brute force. "Lord Stark! You were glorious at the battle of Sherlock. No man is as strong as you! Give it all your might and surely the stone will yield to you!" Obviously, while still in front of witnesses, the nobles will be given more time and privacy for their attempt. Make the circle around the sword where people are not allowed bigger - say 50 ft. When your candidate of choice is to attempt, he'll be far enough that nobody will be able to see how exactly he pulls the sword out - but still close enough that there will be no question that he did gain the sword by himself. [Answer] **Metal expands when heated.** Let's assume that the sword was placed into the stone after being cooled. When it heads up to room temperature, the metal in the sword expands so that the fit goes from 'snug' to 'stuck'. Regular trials can be held at midday, let the rock be in the sunlight. Pulling on the sword will cause friction, and add more heat. Cooling down a big rock takes time, and without technology there's only so much you can do. Keeping the rock out of the sun or having a trial at night might work. There might be a mechanism where they can cast a shadow over the rock for one day. They might be able to run water underneath the area that cools it. The temperature difference might be very small but it becomes just enough to be able to pull it out slowly with no resistance. Using this method, the guards will need a day's notice of the chosen one's trial and will not be able to hold any other trials that day. [Answer] **Resin** The sword is inserted into a shaft in the stone, which is filled with resin/rosin and left to harden. The resin is not visible from above, the shaft narrowly fitting the sword, and the surface covered with stone dust set in the resin. Your hero arrives with a large medieval quartz lens atop a long wooden shaft, garbed in flowing robes, sporting a pointed beard, and generally looking the part. Wide-eyed onlookers stand enthralled as your hero steps into the ring. Nonchalantly planting his staff into the ground, unbeknownst to the crowd the sun's rays on that historical summer day focus upon the blade of the sword, whose temperature begins to soar. Your hero approaches the rock and begins to make strange incantations in a foreign-sounding tongue, dramatically flailing his arms around and occasionally rushing back towards the startled crowd with a demonic wail. Once the temperature has risen sufficiently, the melting rosin begins to emit a faint odour. On this cue, your hero tentatively wraps both hands around the grip of the sword and begins to tug. It slides out leaving a sticky ichor as though the stone was wounded by his dark magic. The astonished witnesses let out a gasp and collapse to their knees, while your hero towers above them, sword held aloft. "Hail, King!" they cry, while your hero cries "En-guh-land!!!" in ancient tradition. [Answer] **A magnetic latch.** Unlike what others have suggested with using electromagnets to keep the sword in place, this would work in a medieval setting. Find 2 natural magnetic stones. Use a sword that has a a wider part of the blade or any other decoration that could be latched in the stone. Attach a magnet to the latch. When the true king comes he will have a magnet in his gauntlet. When drawing the sword he will place his hand on the stone. The magnet will pull the latch and free the sword. This can be as simple as pulling a pin out of place. It can then freely be drawn. At this time magnets should be obscure enough that most people would not even think of it. Even if they did they would need to know the exact spot to place it. As OP mentioned in comments the stone would be guarded from people snooping too hard. [Answer] ## Thermal expansion is it! 1. Choose a rock with hard material that withstands heat. 2. Put the rock over a hot fire and let it heat up. The warmer, the better. Thermal expansion will apply. 3. Drill the hole for the weapon in the hot stone, exactly as wide as the sword is. 4. Put the sword in the hole. 5. Let it cool and shrink. The hole will tighten on the blade from every side, holding it with a force insuperable for mortal beings. 6. Put the sword outside, possibly in a cold environment for maximal effort. 7. ??? 8. Profit Pulling the sword out is easy if you know the trick: just make a fire around the stone, let it heat up again, and you can easily pull out the weapon. Be careful though - hot swords look exactly like cold swords! The though part is selecting a mineral with greater thermal coefficient than the steel your sword is probably made of, so the heating will actually release it. According to [this site](https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html), steel has a thermal coefficient of around 11-12 m/°C. Granite (7.9 m/°C) won't do it, limestone is a good candidate (11.4 m/°C), but I suppose it's a bit too brittle for this. Marble has a range of 5.5 - 14.1 m/°C, which is quite promising. Considering the wide variety of stones around, you probably can find a suitable one. [Answer] Without looking at all the other answers here. It could be possible to place a sword into a stone that is melted like lava. I imagine the stone was not brittle. All one would have to do is add sand to liquid iron or bronze enough to give it a more Stoney texture and appearance. The differences in temperature from the sword and molten Stone would be enough to keep the sword from adhering to the stone on a molecular level. The best time to pull the sword what day wallet it was in the middle of winter maybe on a unusually cold day when nobody is willing to come out and try. The best time to have a sword pulling contest would be in the middle of summer. [Answer] # Magnets, how do they work? I don't remember the exact story, but I know I read a version of this. Basically you construct the rock w/ an electromagnet in it, and until the "guardian" switches off the magnets the sword can't be pulled out. [Answer] Concrete would be available to them, and is quite capable of holding that sword in place. The ancient Romans had concrete, and while not common in the medieval era, its knowledge need not have disappeared. Just put the sword in a mold, pour concrete around it, and have a stone mason work the result until it looks like the shape of rock you want. You can even paint it to look more like a natural rock if you want, or clad it in natural stones. ]

[Question] [ Many sci-fi machines and robots have glowing eyes, though there's no apparent reason why any such thing should be the case. One possible example is something like a cat's eye, where light is sometimes reflected in the dark but that seems unlikely for a digital camera. Is there any plausible explanation as to why a future robot's eyes might glow? [Answer] There's very little reason to have glowing eyes in the visible spectrum. However, in the IR spectrum, we do see them: [](https://i.stack.imgur.com/UhHvNm.jpg) The idea is that most IR cameras are not as sensitive as the human eye, so they need extra illumination to see anything. Putting the IR illumination right next to the camera proves to be very effective -- there are no shadows in the scene when you do this, so there's nowhere to hide. This is practical in the IR spectrum but not the visible spectrum because humans would be very bothered by a bunch of white LEDs lighting up the scene from a camera. However, since they can't see infrared, they don't mind a whole ton of IR illumination coming down. In practice, some of the light from the IR leds is visible as a dull red glow, which shows up pink when photographed due to the way digital cameras process their images. [](https://i.stack.imgur.com/l1r40m.jpg) [Answer] Absolutely, depending on what you mean by eyes that is. If you mean the camera that takes in information, then no, but if you mean the area on their face where eyes would be, then yes. In the movie Chappie, the robotic police force use a display screen where their eyes would be to display information for the humans running them; [](https://i.stack.imgur.com/yqiCl.png) But the screen can really display anything, including eyes that, because it's a screen, glow. The reason why the robot would display eyes is another question, but answers include: human-robot relations, appearing less threatening and artificial intelligence. [](https://i.stack.imgur.com/APilq.png) [Answer] My webcam has a light, as to most video camers to indicate they are recording (or where to look while being recorded). So the reason is a **social convention** or **legal requirement**: a *tally* lamp to indicate that a machine is in fact looking at you, and an indication of how to make “eye contact” because people are uneasy without that. [Answer] If by "eyes" you mean the cameras or whatever sensors it uses to perceive the world visually, no. This is usually done in media for no better reason than because it looks cool. In real life, many robots that are built for human entertainment have what seems like glowing eyes. But they don't see with those eyes. Take [AIBO](https://en.wikipedia.org/wiki/AIBO) for an example: [](https://i.stack.imgur.com/zRFhP.jpg) At first glance it seems like the head lights are its eyes. Look again. A robot could have glowing "eyes" so that a human talking to it will maintain proper eye contact, for whatever reasons the bot's designer had in mind — in AIBO's case it can use its LEDs to communicate. Or they may work as flashlights (for humans, not for the robot) so that one can see which direction the bot is looking at even if they are behind the bot. Or they could serve as an indicator that the bot has your attention, or if it is turned on (i.e.: if the eyes are off, the robot is off or in stand-by). Last but not least — the robot may be secretly communicating using a protocol similar to morse code‡. They are blinking their eyes too fast for us to see. Think about it, a fluorescent light "blinks" 60 times per second and we can't see it. The robots have been telling jokes about us humans all this time right under our noses, next thing they are going to break the first law and kill us all. ‡ Yeah, they could use radio to discuss their plans via bluetooth or wifi, but they knew we'd be snooping that kind of communication. [Answer] > > Is there any plausible explanation as to why a future robot's eyes might glow? > > > Reason #1: Because it's scary. If the robots are built with the intention of being intimidating or frightening, then they will be designed with scary-looking features. Glowing red eyes are great for that, especially if combined with other evil-looking facial attributes. They'll probably also have bulges to make them look muscular, random unnecessary spiky bits, lots of dark coloured brushed metal, and other industrial design cues. Welcome to the future! Muahahaha! [Answer] In the novel *[Robopocalypse](http://www.goodreads.com/book/show/9634967-robopocalypse)* (which is really just *World War Z* with robots instead of zombies) robots have "intention lights" which glow specific colours to communicate to people whether they understand the instruction, operational status, etc. These are simple non-humanoid bots with basic personalities, but as I recall the more advanced bots with "faces" retained this legacy feature. Your bots might have something similar, coded lights that communicate the equivalent of facial expression or status to people around them. [Answer] The [eyeshine](https://en.wikipedia.org/wiki/Tapetum_lucidum#Eyeshine) of certain vertebrates was an evolutionary side-effect, because these animals evolved in an environment where artificial lighting was not available at night. Therefore eyeshine cannot be compared to the glowing eyes of robots. (This side-effect must have saved countless humans who were fortunate enough to gather around a fire). However, there's a perfectly valid reason to have glowing eyes for humanoid robots, or robots who interact vocally with humans and have a face. Humans would be far more comfortable talking to a "face" with eyes rather than [a globe of light](https://www.youtube.com/watch?v=UgkyrW2NiwM). --- Which means, glowing eyes are better than no eyes at all. But if you have the luxury to have eyes with features, it would be way better than two glowing circles. [This paper](http://www.cs.cmu.edu/afs/cs/Web/People/kiesler/publications/2002pdfs/2002DiSalvo.robots%20unequal.pdf) ([ACM link](http://dl.acm.org/citation.cfm?id=778756)) discusses in length about the perception of humans on humanoid robots with varying features. This is what they had to say about the importance of eyes (emphasis mine): > > Human eyes are complex and intricate objects. *To project humanness a robot > must have eyes, and the eyes should include some complexity in surface detail, shape of the eye, eyeball, iris, and pupil*. > > > They also have identified that *eyebrows* do a large part in making a robot humane. [Answer] Perhaps not exactly what you have in mind, but this seems to have a rather simple answer if you look at the problem from a different direction. The computer on my desk lights up when I turn it on. As do most other electronics. It’s a very simple way to allow human users to determine at a glance whether something is active. Very simply, one reason why a robot would light up would just be basic UX Design to provide that affordance to humans who interact with them. After all, how embarrassing would it be to stand there telling a robot to do something without realizing that it’s off? That’s like calling IT support because your PC isn’t plugged in. Using the eyes (or at least the position in which a human would have eyes) as this on/off indication would conveniently line up with a general understanding of our own eyes being either open or closed depending on whether we are asleep. Since most people would look at a humanoid robot's face when attempting to communicate with it, the "eyes" are also very obviously positioned. In short, if your goal is a humanoid robot that interacts with or takes instructions from humans, it honestly just makes sense. [Answer] Well, "future robots" probably not, but when we revert to steam punk, it's worth noting that a number of historical [video camera tubes](https://en.wikipedia.org/wiki/Video_camera_tube) actually featured a glowing cathode for the emittance of the scanning electron beam. Of course, it would be highly unlikely to see that glow frontally (rather than at best from the side of the tube) since the optical path to the charge plate (sort of like the retina) would not intersect with the cathode for the scanner. Where the "retina" itself is a cathode (like with photomultiplier tubes), it's much more likely to require cooling than heating in order to *reduce* electron emission not prompted by light. [Answer] In many cases in sci-fi, eye color serves as a substitute for facial expression - red for angry, blue for cheerful, whatever. If robotic technology is not advanced enough to permit mobile facial features, color-changing eyes might be included as a means of broadcasting emotion. Alternately, it could be a sort of optical echolocation. A common means of mapping is something called an infrared spectrometer, which works by firing infrared at a surface and observing the reflected signal. Now, if for some reason the robot's infrared light source is inefficient, it may produce red light as a byproduct of the infrared. [Answer] You could have a visible-light laser range sensors in the place of eyes. In addition to dual cameras, they will find the distance in a more sensitive way. [Answer] By making the eyes glow in a certain color, you can see how the robot feels. White could be 'neutral', green could be 'happy', blue could be 'sad', etc... Here's a Nao robot at a university [](https://i.stack.imgur.com/0ceV4.jpg) The 'eyes' (they are infrared transceivers actually) have glowing LED's around them. Here they glow green, but they can show any color to indicate emotion or status. [Answer] Yes, yes there is. Psychological intimidation. User interface design, and other interactions with organics wherein knowing where the robot is looking is either psychologically comforting, or conveys useful information (look there!) are also valid reasons. [Answer] For one very large reason that cars use headlights. To *be seen.* It is true that headlights allow a car's driver to see in the dark, but they additionally allow the car to be seen from much greater distances and with much greater clarity, even in the dark. In fact, there are [strict regulations](https://www.fmcsa.dot.gov/regulations/title49/section/393.11) in the US on what kind of lights and reflectors are required for many types of large vehicles, both for visibility and communication, and [boats have standards as well](http://www.westmarine.com/WestAdvisor/Navigation-Light-Rules). Your robots could rely on wireless communication for this kind of information--if you wanted them to--but they definitely don't *have to.* I would imagine any futuristic robots that have wireless communication (you could make [retrofuturistic](https://en.wikipedia.org/wiki/Retrofuturism) robots that don't have wireless communication) would be constantly pushing the limits of how much data they can send wirelessly, and as such, any data that could be offloaded to simple visual or audio cues, such as location, would be utilized. [Answer] # Camera detection Lenses tend to have some glare to them. If you have a light source and detector sufficiently close together, you can notice when a camera is pointed at you from the reflection. # Excess from an IR or UV emitter Many powerful IR/UV emitters also give off some visible light. This begs two questions, however: why the emitter is mounted at the eye, and why they don't bother to filter the visible output. [Answer] Phones often have a light on them for a flash to illuminate the subjects that they take photos of in the dark. If your robot was designed to collect film for the people who built it, it would make sense to make it illuminate the things it was filming. If it were operated by humans, it would make sense to put the light/cameras where eyes would be on a human so that a human watching the video would see what they would have seen had they been there. also, it would mean they could conduct morse code through blinking! [Answer] There's even a reason for them to change color before an attack! TOF, time of flight distance measuring, relies on sending out light, and measuring when it bounces back. Smaller wavelength means more precise measurements. For civil situations, the robots use near-VIS UV, so they can spot hairs and dust. The eyes glow faintly blue. When the going gets tough, the robots switch to near-VIS IR, because they now mostly care about center mass calculations and fog penetration (blood fog may occur suddenly...). Their eyes now glow faintly red. The 3d map TOF generates has to be fusioned with pictures in various wavelengths, so the robots also need a nomal camera - presupposing near future tech that camera need not have active illumination to be superior, though. ]

[Question] [ My 7 year old son and I have pitted the Elves against the Dwarfs - The Elves control the sky - they have airships, gliders in their cloths that enable gliding from airship to airship, and bridges between the airships. The Dwarfs control the underground - living in great underground caves, tunneling from place to place via giant tank-like vehicles with drills attached to their fronts and ends. Between the two races, earth and sky, floats the ominous Everboom - a perpetual cover of stormy clouds, where lightning cracks every few seconds, everywhere (which is a good reason to keep to the underground and very high in the sky). The two races are at war on the ground (still figuring out the details of safely moving through the Everboom), so there should be battles and victories galore, and so on and so forth, and glory to the young story teller. But the teller would have none of that - My son wishes for the two races to be at war but to never be able to complete a battle. In other words - military engagements without a defining outcome. He simply doesn't wish for either of the races to win in any battle, saying that the soldiers shouldn't want to fight - though obviously, he wants them to have do go to battle. The reason for this is a mix of a kid's excitement over cool fighters with cool fighting techniques + cool shiny weapons, and a pacifistic gentle soul. So I was telling him about evil generals that force their unwilling soldiers to go to war, to which he justifiably replied that the soldiers won't have cool fighting techniques + cool big weapons, if they don't really have their heart in the fight. I started suggesting some honor system that would make it viable to have a warrior caste where the guys want to fight each other for honor without killing or something like that, but the boy is too smart and realized that in such engagements, there would be winners and losers and deviations from the honor code, and these would lead to killings and taking-overs of desired resources and/or land. We need armies that wish for war, will ferociously have it out at each other, and when their opponent is vulnerable for the final blow, will say: "See you next time" and go home. Kind of like in kids' tv shows. ***Sigh* - What would be a good reason for a couple of races to want to have serious battles, without wishing to defeat, or take anything from, their opponents?** I would love a sociology/psychology answer, but will prefer one that includes the world's unique physical aspects (the sky/underground factors, the Everboom storm and methods of safe travel through it). There's a bit of magic to be had in the kid's stories, so a very minimal amount of magic is allowed for the answer, but no "A-wizard-cast-a-mystery-spell-over-everyone's-mind" - We're 7 years old, you can't hand wave our troubles away. EDIT: Few casualties are allowed in the fights, but everyone will be childishly shocked and sad when they happen. [Answer] Different approach, after the Comment on my other answer: Maybe that's just how immortal (or very, very long-lived people) always fight - it's how it's always been. Dwarves have fought each other like that because, well - for a human with a finite time to live, dying for a cause to make the (short) life of their children better may seem like an OK deal. If you, and your children, can live forever? Dying for something is a bad deal unless you would die without that thing anyway. A couple bruises and a broken leg though, that's ok. Ditto for the Elves - and when Dwarves and Elves met? They didn't know any other way to fight, so they fought each other the same way. And obviously, if taking someone's life is just not done, the shocked reaction when it does happen would be expected. Nobody's TRYING to kill the other guy, just punch them around to make them see reason (or hand over the thingy we're fighting over) Now, why are they fighting, and why do they HAVE to fight? Of course it could be resources, but I think a better explanation might be: The Dwarves are fighting the Elves because they, with their skyships and all the flying around, are endangering all of Existence. Birds belong in the sky, they have wings - Elves and Dwarves should stay on the ground. THAT is what causes the Everboom. If not for those pointy-eared flighty buggers, the surface would be a nice place to live! The Elves on the other hand, are fighting the Dwarves because they, with their digging everywhere are hurting the land. The earth itself cries out in pain, as evidenced by the everboom - which is obviously caused by this atrocious behaviour of the dwarves. If not for those tunnelling cretins, the Elves could land on the earth without fearing the everboom. Who of them is right? Are they both wrong? Do their rulers actually believe that, or just pretend to so they can motivate people to go to war? That's up to you to decide :) [Answer] What your son wants, and in fact you describe /and when their opponent is vulnerable for the final blow, will say: "See you next time" and go home./ is [**counting coup**](https://en.wikipedia.org/wiki/Counting_coup) > > Any blow struck against the enemy counted as a coup, but the most > prestigious acts included touching an enemy warrior with the hand, > bow, or coup stick and escaping unharmed.[1](https://i.stack.imgur.com/LbB71.jpg) Touching the first > enemy to die in battle or touching the enemy's defensive works also > counted as coup.[2](https://i.stack.imgur.com/ltx8y.jpg) Counting coup could also involve stealing an > enemy's weapons or horses tied up to his lodge in camp.[2](https://i.stack.imgur.com/ltx8y.jpg) Risk of > injury or death was required to count coup.[3](https://i.stack.imgur.com/b56Ye.jpg) > > > Escaping unharmed while counting coup was considered a higher honor > than being wounded in the attempt.[2](https://i.stack.imgur.com/ltx8y.jpg) A warrior who won coup was > permitted to wear an eagle feather in his hair.[2](https://i.stack.imgur.com/ltx8y.jpg) > > > This was a Plains Indians thing and makes for pretty bottomless cool reading. Make sure he saves the references because if ever there were material for a project, this is it: Indians, fighting, but ultimate pride of place going to the one who wins without doing violence. You could riff on this: the **coup stick** [](https://i.stack.imgur.com/ltx8y.jpg) [source](https://www.warpaths2peacepipes.com/images/crow-coup-stick-edward-curtis-1.jpg) has endless possibilities. The Plains Indians also have creatures called hekoya, or sacred clowns. They do everything backwards. They are also called Thunder Beings. Perfect residents of the Everboom. They can enforce the coup system, and award extra glory for especially hilarious coups: like shaving a fallen Dwarf's beard, or gluing an ugly beard onto an elf. *Haw haw!* [](https://i.stack.imgur.com/b56Ye.jpg) [Hekoya](https://en.wikipedia.org/wiki/Heyoka) [](https://i.stack.imgur.com/ZpGZI.png) [source](http://www.wakingtimes.com/2015/08/17/heyoka-harnessing-the-power-of-infinite-mask-wearing/) Last and the root of the problem: your son likes the dwarves and likes the elves. What they need is an uneasy unity against a common enemy. Maybe 7 is too young for Lord of the Rings, but that is what they did with Gimli and Legolas. The beauty of the Monster War is that the elves and dwarves can still count coup or compete with one another, even as they work together towards their common purpose. [](https://i.stack.imgur.com/xxrg7.gif) [Answer] There is something essential to be harvested on the surface of the planet. Some plant that blossoms randomly on surface of the planet. The two races don't really want to obliterate each other (and don't have the means to do it, even if they wanted). Gigantic battles happen wherever the "something" sprouts and subside as soon as it has been fully exploited. **Variation on the theme:** Make the Elves and Dwarfs be part of the same three-forms race: * Elves: males living in the skies. * Dwarfs: males living underground. * Dryads: females living in the forests. Whenever one of the Dryads is ready for "marriage" (whatever form You want to explain to a 7-year old child ;) ) we will have a huge tournament to chose the "husband". Dryads would be willing to abide to the winner, but would sneer to any "unchivalrous" attitude. You can have your battles with the shiniest armors and weapons with as little actual spilled blood as possible (essentially just the inevitable mistakes). You can have further variations on the theme having the two main races to prove their warriorship before marriage with a woman of his own race or stipulating some need of "blood exchange", if single-sex Nations are too far-fetched for your needs. **Mixing of the two:** In order to marry both Elves and Dwarfs need to gift to their beloved maiden a rare flower and so a siege is in act where the plant is about to blossom, but, since maidens from above and below will be watching, warriors need to play fair. [Answer] # Sports What you describe is a sports tournament. People meet, compete, somebody wins. And then everybody hug and go home. People do this today in fencing, kendo and other martial arts. As @Baldrikk wrote in a comment, in medieval times, they had [tournaments](https://en.wikipedia.org/wiki/Tournament_%28medieval%29) which would look very much like a battle. Though in those days people dying in a tournament was not uncommon so this may a bit fierce for your purpose. In between the tournaments, people train with others on their own team. This training can get pretty fierce too. The prize can be those rare resources suggested by others. There will be rules, the most important will be "No Killing or Maiming!" The penalty should at least be that the guilty part can no longer take part in these tournaments. People on both sides have heard that once long ago people were actually fighting seriously over these resources. Both sides agree that the sports tournament is a better idea. [Answer] **The Elves and Dwarves cause the Everboom** Nature itself opposes the very existence of the two races, destined to destroy each other. Wherever they meet natural disaster follows. Their only hope for peace and survival is the annihilation of the other. They are forced into eternal war, whether they hate the other or not, out of necessity. Coexistence isn't just a dream, it's an impossible fact of their reality. But as they meet in battle a greater consequence shows itself. As the two draw closer and in greater numbers the effect intensifies. In the heat of battle with armies charging one another the storm grows to unfathomable strength, unsurvivable to either the Elves or the Dwarves. And so as they clash in a battle for their own survival within hours or even minutes they are again forced to retreat as the storm grows in intensity, threatening to do more damage than the battle itself. To stay would be a suicidal move that would wipe out both armies entirely. [Answer] Maybe the Elves and Dwarves hate each other, but it's like with the Skeksis and Mystics in *The Dark Crystal:* whenever an Elf is injured or killed, their counterpart Dwarf magically suffers the exact same injury, and vice versa. (Ancient curse etc.) So, like a lot of real-world civil wars, it keeps going as an endless cycle of revenge. Neither side can afford to just massacre the other, and if a clear winner ever started to emerge, the losing side would have the nuclear option of mass suicide. The two sides have to maintain an iron curtain and avoid mingling, because neither side wants the other to know who is paired with whom – if the enemy had that info, they could torture or kill your leaders and generals by sacrificing one of their own side. [Answer] Edit: By the time I finished writing my post, others already proposed those alternatives. Oh well. I can think of three alternatives that weren't already proposed: * **Make them inherently good-hearted** There could be numerous personal reasons for the soldiers of your two armies to strike the opponent down, but refrain from landing a fatal blow. They could be fighting for centuries already, with each individual knowing almost every other opponent in the battlefield. Giving your name to your opponent when you're defeated could be a cultural thing, for example. Then, the winner will remember it, the loser will remember his opponent's face and try to defeat him the next time they meet. It's a matter of honor now. This could ensure fair, perpetual fights with possible rivalities towards a particular opponent, leading to even more heroic, *cool*, or even unpredictable actions (IE: Saving your opponent from an accidental death, to be able to try to beat him again next time). The trick here is just to determine how those cultural rules were introduced in the first place. * **Make them tough.** Like, extremely tough. *Survive-a-fall-from-the-miles-high-elf-ship* tough. Battles would last for days, but wouldn't come to any significant conclusion. Both sides would go home, exhausted, with a few scratches and bruises, and set their next encounter a week or two later. Elves are known for their incredibly efficient, instant regeneration abilities, making them nearly invincible, whereas every dwarf master armor crafting so well that they're almost undamageable, on top of their near-perfect defensive techniques, rushing to protect a wounded soldier in the extremely unlikely event of one of them being hurt. (Think of something like a phalanx on stero- I mean, *dwarfoids*.) * **War as a hobby** When you live for centuries (or millenias), even gliding between ships, or stacking gold in your vaults gets old. Your population needs something else to do, something they can find enjoyment with, something that involves a foreign factor that they don't quite master. War is the perfect anwser. But you decide to make it a long-term anwser, instead of a short-term one. You're lucky, your potential opponent has the same thoughts on the matter. So, instead of trying to actively reduce the other population's numbers by killing them, you both agree that it should rather be considered as a sane hobby. Thus, you both greatly reduce the lethality of your weapons, and teach your soldiers to spare a vainquished opponent, and to accept when they're defeated themselves. Both populations slowly start to consider "War" as a fun hobby, and realize that without opponents, their favourite sport wouldn't exist. Some even say that after a battle, they saw a dwarf and an elf share their respective beer. Both had to be evacuated shortly after. [Answer] Gonna answer this inspired by my most hated scenario in video games: ## Healing vs regeneration Elves got healing magic, while dwarfs got tough body and regeneration. They can engage in battles, but they can't really inflict casualties on either side. Everytime they battle, it will get dragged days before they get bored and withdraw themselves. [Answer] I think your son is looking less for a war and more of a conflict. You don't want the two sides to have a desire to obliterate each other, but you do want conflict to occur. Conflict like this is inherently undesirable, so you're going to need something to encourage them to fight... forever. I think there's a few good answers here which hit on a common pattern: The two sides need to be fighting "for" something rather than "against" each other. They must be trying to gain something to warrant risking life and limb. A common pattern we see in answers here is to have some resource on the surface under the Everboom. You need something up there worth having so that these fights are part of life, rather than just part of death. A static resource will be impossible to balance. One side will always manage to take more than the other. However, a dynamic resource is what you really need. You need something very lifegiving and energizing that is part of something much greater than both armies. A Gaia of some sorts. Something that they bring back to their homes that is worth clashing with the enemy every now and then. I'd suggest a lifegiving charge caused by the Everboom itself which accumulates on you while you are in the middle grounds. This might be harvested simply by going there, collecting some on you, heading back to home, and letting it shed off you, but to get the combat you want, you need something more. If you're willing to bring a Gaia like force into play, we can reward "living more full lives." Have the accumulation take on a more powerful form if you are living your life to the fullest while harvesting. The most powerful Everboom mana brought back to the cities is that gathered by those with a passion in their eyes and a thirst for whatever life brings them. Naturally, the Elves and the Dwarves are going to develop their own individual unique styles of lives, and they will eventually clash. Some will learn to live their life to the fullest wielding cool weapons and doing awesome techniques in combat with their opponents. However, this combat would not encourage seeking a total victory. Your son clearly knows that such a victory is hollow. What rings true is standing contested on the battle field and holding your head high. At an adult level, this system also permits interesting runaway situations. If you want to have people's thirst for life be amplified by having more of this mana on you while you search, it will naturally bootstrap its way into conflict with this positive feedback loop. However, the system also puts the breaks on these runaways, if one side ever start oppressing the other, it stops being a "live life to the fullest" and starts being a "mop up squad" job which clearly won't be as effective. As such, the "mop up squad" wont bring back all that much more mana than the peaceful collectors that collect far from the war fronts, but do so with a passion all their own. [Answer] The reason for fighting could be to impress a third party rather than killing your enemies. For Example Dryads could cultivate a seed that grows into a tree that could produce large amounts of food quickly in harsh environments, such as on Airships or Underground. Possessing this could alleviate the need for foraging on the surface for a while until the tree dies, freeing up time for many Dwarves / Elves. Alternatively Goblins could produce navigation machinery that can equally be used for Airship Guidance or Digging valuable deposits underground. Neither the Dryads or Goblins want to see many deaths, but could want their valuables sold/gifted to the most worthy or they enjoy watching the sport of combat without death. These Valuables give a good reason for the Dwarves / Elves to commit to full scale combat with their best weapons and warriors, but not go for the kill. While either race could overpower the Dryads / Goblins and take the treasure by force, they would then not produce any in the future so no one want to solve the issue by force. [Answer] It's really a simple matter: Don't make them actually be at war. Keep most of the elf and dwarf population as gullible as possible while having messengers from their rulers to speak to them saying that victory is nigh. But after a short while have the messengers pronounce that their armies has lost everything that they have "gained" from the other side. How would you keep the populace from questioning their overlords? Attack your own citizens with long-range siege projectiles and say the elves or dwarfs did it depending on the society in question. Getting your citizens riled up in a blind frenzy over the opponent makes them much more susceptible to propaganda. You could have a sort of secret police also patrolling the civilizations looking out specifically for those who ever doubt the ruling caste and ensure they remain in a quasi god-like status. The Everbloom was deliberately placed to deter either side from actually encountering one another and to increase xenophobia between the races by saying to the peoples that the other side is inhabited by barbaric knuckle-draggers. After all, how can you sympathize with someone and their culture if you never meet them? Why would the elf and dwarf leaders do these things? For power, just as simple as making sure that a select few get to live luxuriously while everyone else gets to toil just for them. To quote from *Nineteen Eighty-four*: War is peace, freedom is slavery, ignorance is strength. [Answer] Everboom is clearing out at certain times in a year, but only for **short period**, allowing both parties to come to the ground and harvest food (or whatever resource on the ground). When they met, of course there will be competition on the food, but only 1 or 2 engaged in combat, while the others hurriedly harvesting before the storm comes back. The battle only lasts minutes, and most concludes with both injured, but only rarely killed. [Answer] While the dwarves usually inhabit the under-plane and the elves their great airships, the two are at war. Not a full-scale, destroy-the-enemy-at-all-costs kind of war, but a war over old hatred. A war that you're trying to stay alive, and also keeping your enemy from discouraging you from that goal. In movies, TV shows, comic books, and so forth, there is usually a big bad guy that the good guys are trying to stop; but, if the good guys were constantly defeated by the bad guy, the ending wouldn't make sense when they finally triumph. Instead, the bad guy sends mooks: faceless, nameless, easy-to-beat, throw-away characters. The good guys are worn down by the mooks, making the final battle exciting and climactic. What your world needs are **mooks**; when the elves and the dwarves fight, they don't actually fight each other, but the mooks. The dwarves, being tough engineers that live among the rich deposits of ore, have built rock golems and tough defenses to keep the elves at bay. And likewise, the elves, with their love of nature, make tree golems and forests woven into walls and other defenses. The dwarves guard the entrances to their tunnels, fortifying the area and building armies of mindless rock golems. The elves, threatened by the heavy hordes they see amassing at their border, launch attack after attack at the war camps they find. Their goal isn't to kill, or even injure, but to *de-weaponize* their enemy. Once they've razed the fortifications and destroyed the rock golems, they retreat, their job complete. On the other hand, the elves feel the need to defend the few breaks in the clouds that can be used as landing spots, and will sprout entire forests to weave into great walls; the landing platforms are guarded by armies of mindless tree-golems. The dwarves, seeing the elves amassing an army on their very doorstep, send out raiding parties to burn the lofty strongholds to the ground. Both sides attack each other, in daring raids of danger and force, and both see the other as a threat, but the only casualties are the "automated defenses" - the golems and the fortifications. [Answer] Elves are **deficient in vitamin D production**, and dwarves produce **too much beta carotene**. Making each other's homeland a wasteland to the other. The ground will be fought over forever, but neither is interested in settling the other's territory. Too much beta carotene makes humans sensitive to sunlight, and lack of sunlight makes it difficult to produce vitamin D. The only reason they fight in the first place is to compete for enough resources to get back home. They say, *"See you next time! Ha ha!"* as they wave back at you after stealing the vessel you've been constructing for the past seven months. [Answer] Elves and Dwarves both live long lifes - and reproduce slowly. Any soldier who actually dies would be a great loss to the race/kingdom. And they know this about each other. But there's still stuff to be fought over (ressources, prestige, what have you), so they have to fight. How do you avoid the enemy mercilessly slaughtering your men if you lose a fight? **By showing mercy yourself** The instant one side starts killing off the losers, the other side would do the same. So to avoid having your OWN people killed when you lose, you avoid killing the other side's men when you win. Nobody wants this war to become an ugly chain of weeping widows and orphans questioning why their ruler allowed their husbands/fathers to die, so everyone sticks to the honor system of "don't kill the losers". /edit: this would even explain the cartoonish shock when someone does die - "oh shi..., I hope they don't think we did this on purpose and broke the honor code!" [Answer] Though they are different creatures entirely, they could have a shared cultural view of war similar to that of the [pre-Shaka Zulu](https://en.wikipedia.org/wiki/Impi#Limited_nature_of_early_tribal_warfare). They meet at predetermined places at predetermined times, do some light fighting, throwing spears or whatnot, and eventually just get bored and leave. Whoever "won" takes a prize of some sort, but that's mostly it. This happens because both sides have low populations and don't have independent military structures: the soldiers are also farmers or doctors, etc. Taking battles too seriously risks losing essential personnel, personnel seen as more important than whatever they're fighting for at that moment. [Answer] One possibility to have the different races battle without defeating the other is to make it physically impossible for them. You could make both races send out armies to attack the other, but they can't find the opponent's armies in the Everboom. The other is to have them fight against a common enemy, or to compete for a resource. Have the two races start to attack each other, then have a bigger threat come and force the two races to stop attacking each other, or have them race to momentarily appearing resources. Neither would be at war for fear of total annihilation, but would cope with small skirmishes. [Answer] Dwarves might have a slow breeding rate yet still make babies at an absurdly higher rate than elves, while elves use their nasty illusion magic to avoid getting killed because they're squishy. The elves simply tend to win quickly in a fight, overwhelming the dwarves with magic and, apparently, flight technology or they get slogged down. If the latter happens, the dwarves can close to their devastating range and almost always win. Dwarves must have developed a pretty impressive anti-air arsenal early or they would have already lost. They would still need to tend to win since they can't chase the Elves down and the reverse isn't true. Otherwise, the dwarves would need to repopulate at an even *higher* rate to make up for the fact that you've granted their foe unchallengeable air superiority. Dwarves need something to stay hard to kill by elves, though, to even the fact that the elves can simply flit off. With the population recovery rates different, elves would know that even losing one warrior is a major blow to their faction, and are well aware that a dwarf is deadly up close, so they would skedaddle as soon as things get, shall we say, hairy. Tuned appropriately, the conflict would be a long-term stalemate. The storm itself can set a limit on following up on an overwhelming victory which can prolong the conflict by making such things less strategically relevant. If you have set things up such that elves are medivac-ed out and healed magically, and dwarves generally stabilize if not killed outright, you'd also have an explanation for *increased* survival, but not anything like you describe. Your problem is that there isn't any *realistic* way to prevent death on both sides unless neither side is in any real danger. Well, I suppose you could have the fight through proxies that can be killed or destroyed. Considering the history provides some interesting options: The storm could be a defense the dwarves came up with to deal with the elf air force. Could be part of the elf spells to stay up, too. The airships of the elves could be their response to the dwarves beating on them in an earlier age. The dwarves could be angry about abuses from the elves hitting them and flying away for generations, weakening them. It also makes very little sense that the stalemate is considered a good thing by either faction, so you might consider what plans these factions might have to break it. Capturing a few working airships, for example, even if it costs a few good beards, seems like an obvious strategy. Trying to figure out a scheme to aim and disrupt the portals to the surface the the dwarves use without needing to engage also makes sense. Some might be seeking a diplomatic solution. [Answer] In the fear of making this a political discussion, but still finding this just too good of an argument, I would like to point your attention to the longest-ongoing territorial rivalry in the last centuries: the Palestinian-Israeli conflict for "inspiration". (Please refrain from making this political and only relay criticism of my argument.) What makes this conflict so devastating and eternal, even almost unresolvable as many commentator fear, is one thing: identity. Deeply entrenched in both cultures, and self-awareness, is the understanding that they have been wronged by a wrongful oppressor. Due to the sense of victimhood and fighting over something that lies mainly in the past, a so-called "enemy image" (from German: Feindbild, see [1]) is constructed and embedded in the self-perception. Allowing that enemy to be granted part of the "cake" would mean accepting that a vital element of identity is obstructed and put into question. For many people, as soon as a belief, a value or an opinion becomes an identifier, further discussion is futile. It renders its former status invalid, and shifts to becoming an ideology. When that happens, all conflict will become endless, because it goes to the core of an individual's self, identity (am I becoming a broken record?). How this could play out in your story is with a benevolent, pacifist king, i.e. your son, that does not want blood to be spilled in the name of an eternal war, but that allows for poisonous weaponry to be used to stun the opposing force. At the end of a day, losses are counted. (This might give an advantage to the more filigree elves and their master archers, contrasted to brute force of dwarven warriors). [1] [See this great discussion in German about the concept and its implications in the Middle East tensions here](https://www.amazon.de/Feindbildkonstruktionen-Nahostkonflikt-Ursache-Scheitern-Roadmap/dp/3842889674) [Answer] In ancient times the Dwarfs and Elfes lived peaceful at the surface. Then, for some long forgotten reason, a terrible war started. This war lasted for a long time, terrible crimes where commited, cities turned to ashes and children and elders slaughtered. The war raged on until both sides where close to extinction. When both sides rallied for a last, deciding battle, the Gods had enough. A terrible storm formed, growing and growing, until finaly it covered the whole survace. The Dwarfs tried to hide in their underground Strongholds, while the Elfes climbed into their latest warmachine, a class of flying ships and retrated to the sky. Both sides had a hard time, barely surviving by diving into the storm for short periods, scavaging the ruins of their once great civilisation, until they found that slowly the magic of the storm cristalled in a form of glowing gems. The magic of the glowing gems allowed the dwarfs to build their underground vehicles, but more important, magic Laterns that shined true sunlight and allowed them to build farms deep in the caves. The Elven on the other hand used them to build giant floating farmships and whole cities in the sky. Now small Parties of the boldest Dwarfs and Elves scout the Everboom, searching those gems to keep their civilisations running. Obviously those scouts meet now and then, and both need to secure the gems. But the Stories of the Gods wrath is well embbeded in their cultures so instead of a all out Fight, they meet to ritualised Duells in the middle of the field. Great honour awaits those that best their rival, but if they kill him honour (and the fear of the Gods) forces them to pay for it. They leave their clans and families and turn themselfe in to the family of the killed, honourbound to do their best to repay by taking the place of the dead instead. [Answer] What if the battles were rites of passage that the tribes had to pass through to achieve Nirvana. They keep trying to have the most noble battle where all their sides combatants behave in a 100% noble manner and then they can all resurrected. The elves and dwarves are both trying for the same prize and only ONE can be saved. Blah blah bla. [Answer] I'd write gaps into the Everboom, eyes of the storm that could be hundreds of kilometers or more across. As these gaps form and move, the two races could battle there while scrambling to retrieve a resource while it is exposed. [Answer] By limiting the possibilities for a big war with loads of deaths, the war could be prolonged (i.e. endless) and only occasionally mortal. Let's say the war is for a resource which is only present at certain times - as suggested by others as well. "The nectar of the glowing Myrados-plant can be harvested in full moon only". Now limit the space: "The glowing Myrados plant grows on tiny patches of land, present in the deep and dangerous Gleerphil - a huge swamp land in which you must travel very carefully and with no heavy load." Only being interesting around harvest time, and impossible to secure by using a huge army, the Myrados in the Gleerphil sparks conflicts on a regular basis. Sometimes one of the parties might send ten warriors, other times just one. Depending on weather etc, the different strategies have varying chance of success. And whoever wins, there will always be a chance for revenge at the next full moon. [Answer] # Explanation The Elves and Dwarves are actually ancient trade partners. The elves need minerals mined by the Dwarves, while the Dwarves need rare gases only available for collection to the Elves. However, they do not have a proper market economy and thus don't know how to adequately price their wares for trade. So they fight each other almost to the death, and the victor gets to demand a greater share in their next trade negotiation. # Motivation Part of the reason that their conflict is so bitter is that when one side or the other runs low on the traded resources, it causes great pain and suffering for the local population. The Dwarves need gases for both energy and medicine, so a medical gas shortage leads to greater illness amongst the Dwarves. The Elves need to repair their airships which are often damaged by stray lightning from the Everboom, and when one fails catastrophically, some families must cram aboard their neighbors' airship, leading to overcrowding, food rationing, etc. The conflict is as much about venting the rage of these perceived induced sufferings and indignities as anything else. But because Elves don't really want to run around the ground, nor Dwarves want to fly through the sky, conquest is simply out of the question. And because of their codependence, annihilation is also suicidal, even though both sides despise the other bitterly, and blame each other for their suffering. # Conclusion The rulers of each faction cannot really contain or reduce the pain and suffering of their peoples, because neither side has the leverage to force more trade. Or because both populations are at the limits of resource extraction, and more trade could not occur even if they desired it. So they rely on the glory of battle to appease their subjects, and hold great celebrations when their side has scored a major victory. [Answer] I would suggest that they buy their arms through a third race. The weapons are better than what they can make, but suffer 'durability issues' that are actually a form of planned obsolescence. The third race profits greatly from the war, and more warriors means more purchases. Could even add in that the primary resources they fight over are what the third race charges for the weapons. Makes the dwarves and elves both capable of being the good guys and adds some later plot hooks if the story ends up in the direction of discovering the ruse. ]

[Question] [ I don't like the direction where mankind is going. We spend more resources to build tools which allow us to watch cat videos than on curing cancer. One day I decided to say enough, and leave this grim place. The plan is to gather around 500 people who want to leave the planet with me, then help me to gather money, build a ship and leave. Now we don't have a goal, so our ship will be flying though space for centuries, until we find some nice suitable and friendly planet to settle down. Sounds simple, so what could possibly go wrong? My spaceship needs to be big. It has to provide living space for my crew. I know, if you put too many people in too small a space, it creates conflict, and we don't want this in our ship. Another thing, the ship has to provide food and water for them, so we need additional space for growing plants, and probably some large storage areas for all spare parts. There are small chances we will be able to restock after we leave Earth. Is my plan feasible? Do we have currently have tech to build that kind of ship? What will be estimated time/costs to build it? Where are the drawbacks of my plan? [Answer] I remember a few years ago reading an article which stated that a manned trip to Mars (with return) for a couple of people could be as high as 1 trillion USD (1,000,000,000,000). This group you're supposing is several hundred times larger than the Mars trip, for several hundreds of thousand times longer trip, and they have to create a means of survival instead of supply. Even ignoring current technology and just looking at a terrible estimation of price, there's no way you're making your trip. Let's say (again, as a terrible estimate) we'd be running a price tag of 60,000,000,000,000,000,000 USD. The GDP of planet Earth (which note, it uses the GDP to sustain itself, so we can't just yank it over to our project to fund it) is estimated at about 107 trillion USD. To clarify: Earth's GDP is not even 1% of 1% of what we're estimating for the cost. Of course any price estimation is ludicrous since we simply don't have the technology yet to build such a massive spacecraft with such longevity and self sufficiency. Even if we had 60 quintillion dollars of 'value' (labor and supplies) we have nothing to throw it at to make this happen. Science and engineering will have to progress significantly before we reach the proposed goal. Sorry, Professor Farnsworth, but you'll be staying with us a bit longer. [Answer] You know, I'm kind of annoyed with these questions. Not because they are bad questions, but because people seem to forget what mankind is truly capable of when the chips are down. ## Let's start with the ship needed. First off, **ship design**. Yes, scale is important, but not as important as a dozen other factors. First, you need something that rotates, to help build up centrifugal force (simulating **gravity**). Then you need to factor in an insulating layer to protect the inhabitants from cosmic rays, space debris, and other undesirables. So. Rotation of habitable section. Look at the Ark from Halo for a beautiful example. No, I'm not talking about scale, I'm talking design. [](https://i.stack.imgur.com/W8Gho.jpg) What you could take from this is that circles are your best bet. So the habitable zone of your ship should be designed around this concept. But it also has to be able to reliably fly through space, so how to do that? Well, look around and you'll find dozens of concepts. Just to offer a few: [](https://i.stack.imgur.com/7D2eb.jpg) [](https://i.stack.imgur.com/ubfoY.jpg) What you want to keep in mind is two things. One, the ability to dock, take off from your 'mother ship'. So you'll need a section that can counter-rotate so it doesn't screw up the artificial gravity for everyone. I'd advise the second design for that purpose, and make sure to use some kind of logarithmic acceleration/deceleration to make the transition as smooth as is humanly possible. Keep in mind that this section has to be large enough to house several smaller ships for manned and unmanned space exploration. You'll be searching for a new home, after all, and you'd want to minimize risks. ## Ship hull requirements! Something to keep in mind, is the current research done to this end. First thing to remember is space debris. There has been research done that highlights these risks and how to best combat them. Make sure there are thin layers of aluminum to slow down the debris and absorb the kinetic force. Keep these layers separated by some kind of shock-absorbent materials -- I believe the latest was a sponge like material, but it all depends on what you can figure out. Check out: [this link](http://science.nasa.gov/science-news/science-at-nasa/2002/16sep_rightstuff/) and [this one](http://www.nasa.gov/exploration/home/antimatter_spaceship.html) for Nasa's current thoughts on the matter for Mars missions (not necessarily pertaining to hull design, but both real-world tech, and more than enough extra information that might well help to further your research). ## How about propellants? Well, there has been plenty of research towards this end as well. [In Situ](https://en.wikipedia.org/wiki/In_situ_resource_utilization) being the more popular, but there have been theories about ionized air being used as well. The problem is that this ejects matter that you won't be getting back, so you'll need to be especially careful with this. I believe the two links from the previous point would prove more useful in this (especially the anti-matter engine proposed), but that isn't yet in our reach to do consistently. ## Great, but how do we build the thing?! Well, that's both simple and complicated. Simple, because it obviously needs to be assembled in space. Complicated because thinking inside the box makes this an expensive means. Or does it? [SpaceX](http://www.spacex.com/) has been doing research into making it cheaper to do just that -- get materials into low earth orbit, for example. They've designed a rocket that can get you up there, and one that can be reused -- which drives down the costs considerably. Now, if you use the In Situ propellant, combined with this rocket? It would drive down your costs considerably. Now, once you get your things into orbit, you need to assemble the thing. You can do this the old-fashion way, of sending people up there to do just that. But frankly, that is both costly (you have to pay them) and inefficient (training needed, how cumbersome current spacesuits are, etc) so you're better off with some kind of remote controlled robots to do the assembly for you. First off, it simplifies things (no need to return them to earth every few months, you can have a team of operators controlling them from earth, and they don't ask for hazard pay). As well, if something happens to the robots, you can have other robots collect them and return them to earth with the next shipment to drive costs down even more. Your project won't get the negative publicity for costing human lives, and it means things can be put on a tighter schedule than it otherwise might. ## Ship's built, now what? Well, with the 'hard part' done, you'll want to test the ship for habitability. So in the next shipment, you want plants for aided oxygen scrubbing, and animals to test if everything is safe for human occupation. I'd advise taking a variety of both (start with potted plants, rabbits, rats, and chickens). Why? Because the more data you get at this point, the better. In addition to them being there, you want sensors that are continuously tracking air composition, air pressure, temperature levels, radiation levels, and all the fun stuff. If something happens at this point, you're still golden, because it would kill animals, not you and your fellow 'escapees'. Let these beings survive for a year in space. Test effects the environment has on them, and be sure to test your ship in a solar storm (kind of important if you want to survive on the ship for many generations). ## And last, but certainly not least: financing the whole thing! So, we know from other answers that cost is a big thing. So how do we work around that? Well: research. You need to approach many governments/space agencies with a proposition of research. Do not tell them you're building the ship for escape, that's just silly. Say you're a group of scientists trying to prove the habitability of space for humans. Your 'project' is meant to stay in earth orbit, or at worst be a cheap means to travel between earth and Mars (whatever sells the idea better). Do the scientist thing: produce papers for peer-review based on your findings, play the game for your investors (keep them happy and paying). Then, once you and your fellow 'escapees' feel confident the ship meets your standards, announce that a team will be moving onto the ship for human testing over the course of X amount of time. Once everyone that is meant to be on the ship is on the ship, and you have everything you feel you would need: **Set course for the second star on the right, and keep on 'till morning.** [Answer] You are only taking 500 people. That may sound like a lot, but it is not when you are considering breeding populations, genetic diversity, and so on. With only 500 people: 1. **Everyone has to breed** to keep the genetic diversity up. No-one get to choose not to have kids. Now you might argue that donated sperm or harvested eggs will do the job, so the folk who are uninterested in kids don't have to raise them. But that means some other people have to do it, and you can bet your bottom dollar they'll be calling you selfish and/or society insists that you do it. 2. **Everyone has to start and stop breeding on demand**. There is no room for a population explosion on a starship. Want 3 kids? Tough luck, your allocation is 2. Want a kid now? Tough luck, you'll have to wait until Old Mrs Miggins pops her clogs. 3. **Everyone has to do an approved job.** This starship needs to be kept running, generation after generation. You might want to be a ballet dancer or games designer or the pilot, but what the ship really needs right now is 4 sewage workers and 14 child minders. So if you want to live in a dystopia, go right ahead. I'll stay here with the cat videos! :-) [Answer] Costs: I like to examine naval ships for estimates like this. They're the largest mobile structures on Earth, and require people to live together for months at a time. For reference, let's look at an [Iowa-class battleship](https://en.wikipedia.org/wiki/Iowa-class_battleship). It has a crew complement of around 2,000. You're very concerned about living space, so we can give everyone 4x the living space the US Navy does it's sailors. This is still going to be pretty cramped, honestly. While it's true you won't need weapons, the space taken up by weapons on the battleship will be taken up by advanced propulsion, life-support, and structural systems. So, to break it down: * It takes NASA about \$10,000/pound to put things into space. * An Iowa-class battleship weighs about 50,000 tons * It would cost NASA $1 trillion to put an Iowa-class battleship into space. Probably more, since it would have to be done in many, *many* trips, and this doesn't take into account the cost of the spaceship *carrying* the battleship. * For reference, [this post](https://space.stackexchange.com/questions/88/total-mass-sent-into-orbit-over-all-history) estimates people have, in our entire history, sent only 11,575 tons into space. This doesn't even take into account developing the technology for a spaceship this size, keeping that many people alive, constructing the ship (in space), etc. etc. etc.. Essentially, you're better off buying an atoll, living and preparing on the atoll for a few generations, and every century or so see where humans have gotten technologically, and then re-evaluating. [Answer] **Short answer:** Not currently feasible with our current technology, or any we're likely to get in the next generation or two with the current intensity of research. **Long answer:** Probably the biggest challenge (and there are many massive challenges here) is the creation of a working "closed ecological system" or biosphere. We have not successfully managed to create a contained, working multi-year biosphere here on earth, yet, and that should probably be the first step. [](https://i.stack.imgur.com/bk4d4.jpg) There have been attempts. [Biosphere 2](https://en.wikipedia.org/wiki/Biosphere_2) was one, which highlights many of the challenges that such efforts must face: > > Biosphere 2 suffered from CO2 levels that "fluctuated wildly," and most of the vertebrate species and all of the pollinating insects died. Insect pests, like cockroaches, boomed. [...] > > > clogging filtration systems, unanticipated condensation making the "desert" too wet, population explosions of greenhouse ants and cockroaches, and morning glories overgrowing the "rainforest", blocking out other plants. [...] > > > The oxygen inside the facility, which began at 20.9%, fell at a steady pace and after 16 months was down to 14.5%. [...] > > > carbon dioxide was reacting with exposed concrete inside Biosphere 2 to form calcium carbonate, thereby sequestering both carbon and oxygen. [...] > > > a severe dispute within the management team led to the ousting of the on-site management by federal marshals serving a restraining order, leaving management of the mission to the Bannon & Co. team from Beverly Hills, California. At 3 am on April 5, 1994, Abigail Alling and Mark Van Thillo, members of the first crew, allegedly vandalized the project from outside, opening one double-airlock door and three single door emergency exits, leaving them open for approximately fifteen minutes. Five panes of glass were also broken. [...] > > > Mission 2 was ended prematurely. > > > Others include [MELiSSA](https://en.wikipedia.org/wiki/MELiSSA) and BIOS-1 through [BIOS-3](https://en.wikipedia.org/wiki/BIOS-3), which were more successful due to being on a smaller scale, and less "closed". [Answer] I won't even bother with a cost estimate because firstly you would need to focus on the how. We are of course talking about something that was never done before and a little beyond the limits of humankind right now. But then so was the first Moon landing. First off, if you want to have a living space that exists for centuries you'll need a recycling system for every resource necessary for human survival. Think Fallout Vaults in space + storage tanks. Yeah, it's gonna be really, really heavy. For me this is pure science fiction, as humans need the biological fauna in the air to maintain several core functions like digestion, and essentially will lose a small amount of this mass to energy anyway... requiring a massive initial store if they hope to replenish this energy loss for centuries. This system will take easily 50x the living space of a crew member - per crew member - if it's possible at all. If someone wants to edit this with something I don't know, they are welcome to, but even if we had systems like this that would work on the moon, we don't really have the materials to lift something that heavy into space. As for the 500 men, I believe the simplest method using current technology would be to send up around 30 cargo launches and drop pieces of the ship into orbit, then stitch the vessel together in high earth orbit. Doing this allows us to avoid the stress a 500 man vessel would put on the ship as it fights gravity on liftoff, but would make it unable to land elsewhere, so you'll need a landing probe. Then you need fuel. Antimatter would be the first call of the science fictionista, but realistically speaking you're mostly gonna be stuck on solar sails and ion drives. There are the new omnidirectional-drives that came out of NASA a few years ago, and a few other things, but nothing concrete. We could do it, it just would take the entire earth's efforts for several years. [Answer] The [L5 society](https://en.wikipedia.org/wiki/L5_Society) was a group like what you describe, and spent a lot of time and resources trying to answer this question (see publication archive [here](http://www.nss.org/settlement/L5news/index.html)). The path they planned to take through space was similar to Earth's, but sixty degrees behind (or ahead) in the orbit around our Sun (which in turn moves around the galaxy which itself moves through the universe). They've since merged with the [National Space Society](http://www.nss.org/), with a stated vision of > > People living and working in thriving communities beyond the Earth, and the use of the vast resources of space for the dramatic betterment of humanity. > > > Check out especially their section on [Space Settlement](http://www.nss.org/settlement/) and the links in the blue box at the top of the page, particularly [Orbital Settlements](http://www.nss.org/settlement/space/index.html) if you want to keep traveling through space a reasonably constant distance from a significant source of energy. --- Also, if you haven't seen it already, watch [WALL·E](http://www.imdb.com/title/tt0910970/), which is premised on a scenario very similar to the one in this question. [Answer] A ship so large would not reach escape velocity with our current technology. You would likely have to assemble the ship in orbit, a bit like how the ISS was constructed. This would be immensly expensive, considering that the Atlas V costs NASA $20,200 per kg sent into space. Construction of this ship would take several generations even with NASAs funding. After this, you need to transport the people, equipment, plants, food, water, anything else up into space too! Also consider that travelling at the speed of the [Voyager](https://en.wikipedia.org/wiki/Voyager_program) probes (17 km a second relative to the sun), it would take you nearly 10 years just to reach Pluto. The most earth-like planet that has been discovered is [1400 light years away](http://www.universityherald.com/articles/21779/20150803/kepler-452b-the-astonishingly-impossible-travel-distance-to-earths-bigger-older-cousin.htm), so it would take nearly 25 million years to travel there at the speed of the voyager probe. Unless you were in suspended animation (current technology has a 100% death rate) , you would never live to see that planet. In fact, if you sent a newborn child and its parents into space on this ship - travelling at 17km per second - the newborn would have travelled 75 billion kilometers by its 95th birthday. Sounds a lot? That's almost 0.008 lightyears! So the short answer is yes, it might be possible, but you would not live long enough to see it happen. In fact, if you built a generation ship in the hope your grandchildren's ancestors will make it there, i am willing to bet that new technology on earth would be invented before they reached the planet, and the human race would fly out to overtake the original ship. [Answer] You have already planted the seeds of your failure by including any other person. You are packing along the problems you are trying to escape. Even if these people are like-minded, you cannot guarantee their children will conform to the rules of your new world, or that power structures evolving within your group will corrupt your citizens into kitten-obsessed fools. See: Rama II Imagine the obsession with Old Earth Kittens when they don't have any cats of their own to play with. Someone is likely to smuggle a favorite pet aboard your vessel, which will then be cloned to meet the demand for adorable pets. When your crew has eventually killed each other off, leaving the kittens to eat the evergreen algae supply and evolve on the self-maintaining ship into intelligent beings, the new Homo Felinus will return to Old Earth, determined to satisfy their own obsession with the pictures of adorable human babies they've found aboard their world. See: Seveneves Your question isn't "I don't want to live on this planet anymore", it's "I don't want to live with this species anymore". Answer: Sorry, but you're stuck "here" with us, no matter where you are in physical space. [Answer] Nobody has mentioned [clanking replicators](https://en.wikipedia.org/wiki/Clanking_replicator) yet? OP, I have the answer. All you need to do is build a robot that can build a copy of itself from the raw materials available to it in its environment, under its own power. Then you fly this robot out to a rocky moon somewhere, wait a few years as it disassembles half the moon into useful robots, and then wait a little bit longer as you program those robots to build [the ship you need](https://en.wikipedia.org/wiki/Self-replicating_spacecraft). You then tell the bots to fly that ship over to you, you get on, and off you go. Who cares about Earth's GDP when you can logarithmically turn parts of the material universe into production? Oh, and one little thing - you're probably going to want to make sure the robots **never, ever, under any circumstances** [mutate](https://en.wikipedia.org/wiki/Grey_goo). Pro-tip: this [won't work](https://en.wikipedia.org/wiki/Self-replicating_spacecraft#Implications_for_Fermi.27s_paradox). But what's stopping you from trying ;^) [Answer] No, it's not feasible at all. There are a million reasons why it wouldn't work, but I'll just touch briefly on the major ones: * There is no drive that will take that much mass that far. Even Voyager 1, after 38 years, is only 25 light *hours* away, and that was a 825 kg probe. * There is no energy source that will power the drive and life support. Nuclear is too heavy, solar won't work once you leave solar system. I guess you could try wind... * There is no system for maintaining a closed system with such a community, or keeping the ship maintained, that long. You will need inputs, which you can't get in outer space. * You will not be able to grow enough nutrients to feed everyone a balanced diet. * Space radiation and other hazards would kill everyone. * The construction of such a spaceship is very difficult. If every nation of the world made it their #1 goal, just taking 500 people to the moon and back would be very costly and take decades. What you suggest is just inconceivable. * 500 people is too few. The children will be inbred and social order will collapse within decades. There won't be enough specialists in medicine, engineering, and other key disciplines to maintain the ship. There's not enough resources to train people in highly specialized professions, so future generations will be even worse. * If you somehow obtain the resources and start such a project privately, this will cause global economic and political instability, which will come back and destroy your project. You don't like cat videos? Go start your own country and make them illegal. Better yet, just run for office in yours, or start an advocacy campaign, or... Well, anything else than building a generation ship. Incidentally, what will be your ship's policy concerning asking questions on StackExchange? [Answer] ## Transform an Asteroid [](https://i.stack.imgur.com/UvizF.jpg) I would suggest that your 'spaceship' actually be a medium sized asteroid. Build shelters, perhaps underground to help shield from radiation and debris, and attach propulsion systems at various points such that the ship is relatively maneuverable. Choose an asteroid that has raw materials for use in propulsion, energy generation, repairs and most importantly has water. It would be good to have dirt so that mixed with human, animal and plant waste, would be suitable for farming (in the shelters). An energy source to keep the lights on would help with keeping plants growing and our biological clocks. It would also have a bit of gravity without having to have tech to keep it spinning. ## Cost Getting investment to mine asteroids should be easy since they are so rich in precious metals - just don't let them know your real plan. Everything needed to get the asteroid here and mine it could also be used for getting it somewhere else while living on it. Send robots to 'mine' and test the materials for economic forecasts. Creating living quarters for robot repair crews is reasonable. Everything needed for mining is also reasonable for 'escaping'. ## What's missing? Mining tools for space and propulsion systems for that massive of an object. ## Time 10 to 20 years is a solid guess based on speculation and ignorance. ## Drawbacks Longevity (will the asteroid run out of materials before your descendants reach their destinations) and general human interactions as others have already noted. [Answer] While theoretically possible, we lack the technology to do it. And the finances you'd need to do this would probably be much higher than what you'd need to fix earth. You would need to build said spacecraft in space, since launching something that massive is currently impossible. That means probably thousands of return trips between earth and your space-dock(That you would also need to build). It would probably be cheaper to engineer a virus that would kill most humans on the planet, and then just rebuild earth as you see fit :). [Answer] Looking at the wiki entry for the ISS, it took the combined efforts of 26 countries, $150bn of finance 18 years to build. At any one time the station can support 6 permanent crewmembers. We support the crew from Earth by sending the ISS supplies. They're not exactly growing food in abundance but they do have some small plants: <http://www.nasa.gov/mission_pages/station/research/10-074.html>. Thus food and water would quickly run out without contant supply of resources from Earth. The station is also not traveling space (it's in orbit so it is moving) so propulsion would be pretty slow (going or stopping), and the zero gravity would wreak havoc on people's health over a long period. From what I can tell we don't quite have the technology for prolonged space flight, the costs of the project would be staggering (as Nex Terren pointed out), and it would likely take the a significant portion of the lifetime of your 500 people to build. However, 50years ago the same could've been said for the cost of an international space station. So it's not unlikely that prolonged space travel would be quite feasible in next decade or so. [Answer] The ship itself is barely possible, if very unlikely, with current tech. You would need to be able to reach Mars at a minimum, more likely the asteroid belt. One of the moons of Mars, or a suitable asteroid would become the base of your ship. If enough life sustaining resources cannot be found locally while converting said chunk or rock to a ship, then they would have to be shipped up out of the gravity well. That would take both time, money, and more resources. If the recent research about electrically generated thrust is in fact accurate and can bee scaled up (yet to be proven) you would then also have the engines necessary for the journey. Sadly, we lack the knowledge and experience necessary to create sustainable, habitable biomes. Socially and genetically, we are not in a good position to build a generation ship at this time. All things taken into consideration, it does not seem currently possible without some sort of a McGuffin (or two) to cover our lacks. [Answer] Centuries? With current tech it would take 30,000 years to get a probe to our nearest star, Proxima (as they say in the news today as there's a planet there - lucky!). However, as Proxima is a small star that spews out so much deadly radiation, you'd have to go to the next nearest, which I think is Tau Ceti, 4 times as far away and possibly still uninhabitable, even if it does turn out to have a planet in the right zone that has the right atmosphere, and no Ceti-dinosaurs (or whatever). So you're pretty much on to a loser right away, considering all of recorded human history is roughly 6,000 years old and you have to spend 5 times that just to get somewhere bad... you will either have to stay on board forever, or stay nearby in orbit. So a world-ship that can sustain a population has to have quite an extensive ecosystem (eg Earth itself is one), complete with enough materials to self-sustain for millenia. It doesn't have to be as big as the planet but it will have a maximum sustainable population, but I think you will underestimate how big it still needs to be to house only 500 people. If you have technology then you will also not only need to be able to maintain it, but also have to maintain a society capable of understanding how to maintain it - and note: a priesthood that knows the magic words to turn the big atmosphere machine on and off isn't going to cut it, you'll have to have proper engineering understanding that can also cope with changes in society that will inevitably occur over 5 times the length of human history! Or you could sit in orbit as a new independent "country" and trade with the planet below for whatever they need. This is far more practical until (or if!) someone develops a FTL drive. [Answer] We do have the ability to construct a massive ship, but we don't have the technology to launch one. Your best bet is to construct the ship in orbit around the moon. That saves you the large amount of fuel you would need to get it off the earth. The diameter of most payloads on existing rockets is limited to just a few meters. Any ship you could construct in orbit using conventional rockets would have to be made of hundreds of small modules, either put together like a honey comb (which would actually be pretty rugged in case of hull breaches), or a series of segments like the ISS. Also, if you want everyone to survive the radiation, the hull would need to be metal that is several feet thick. Also having a hull that thick would be necessary to survive thousands of years of colliding with space dust and micro-meteors. That would be way to heavy to launch from the ground. Secondly shipping raw materials from the earth even to low earth orbit is about $2000 a pound at todays commercial prices. The moon is actually pretty rich in Titanium, which you could use to build the hull. It could be much cheaper to set-up a mining and casting operation on the moon that could fabricate the largest metal pieces of the ships hull. You could use a space-elevator going from the moon's surface to lunar orbit to get the large metal parts from the surface of the moon into orbit around the moon where you are building the ship. That would be significantly cheaper and easier than rockets. A space elevator from the earth is not possible with todays technology because carbon-nano-tube ropes with sufficient fiber length are not yet mass-producible. But a space elevator from the moon is possible with conventional steel cable due to the lower gravity. Companies like LiftPort (www.LiftPort.com) have already developed every part of the space elevator technology and are only awaiting more money, and a customer. Your ship will need to be completely self-sufficient once its flying, so you will need machine shops on board that can make or repair every part of the ship, and fabricate every type of micro-chip or circuit card. As it happens, you can save a lot of money by fabricating the machine shops on the moon as a module, and then using them to initially build the rest of the ship. At some point in the construction, the fabrication facilities are moved from the lunar surface to become part of the ship itself. That means that you get most of the cost of the moon base for free since it was really just part of the ship. Also, very importantly, by using the ships own machine shops to initially build the ship you prove that you can really repair and replace any part of the ship using the tools and processes available in those machine shops. It eliminates the possibility of forgetting something until after launch. Over time things on the ship will break. Those machine shop modules will need to make or repair every part of the ship, and fabricate every type of micro-chip or circuit card. Also you should have multiples (at least 3) of every tool or system, so that if one breaks there is a backup. Also, its better if each backup system is not identical so they don't all fail at exactly the same time due to the same disaster. You will need a nuclear reactor to power the ship. A solar array won't generate much power as you move away from the sun. The trip time could be just a few years or decades if the planet is in our solar system, or perhaps one of Jupiter's large moons. The trip time will most likely be 1000s of years not 100s if the planet is outside our solar system. The ship design would be vastly different depending on which scenario you choose. If you just need to travel a few years/decades you could get away with just recycling water and air, with a huge storehouse of dried/canned food. If you have to leave the solar system then you will need to recycle everything. We do have recycling technology. The toilet on the international space station for example recycles all the urine back into water for the astronauts. But of course plants will do that also if you like. I already mentioned some price cutting measures, but its worth noting that one can't really estimate the cost of this design by comparing it to historical rocket prices which are based on the way the US government builds things by bidding them out to way over-priced defense contractors. The reason Space-X was founded was because Elon Musk realized that the price that Boeing/Lockheed were charging the U.S. gov for rockets was about 100x the cost of the raw materials. Secondly, building a much larger ship would probably get a further price break due to economies of scale. Thirdly, the 500 people who are going on the ship need to know how to build it anyways in case something breaks. So they might as well build it themselves the first time (so you save a lot on labor costs). A good portion of the people you bring will have to be PHD level scientists and engineers who are capable of doing the ship design. Elon Musk, founder of Space-X wants to make mankind a multi-planet species. So someone like him might be willing to pay for the construction of the moon base, in exchange for your group doing the design and construction work for free and then giving him the rights to sell access to the base, or license the plans to others for profit. It really would be a great deal for him because most of the cost of developing anything is the labor cost to all the scientists and engineers, and techs who build it. In fact every part of the ship design could be license or sold for profit to help finance further construction. There are plenty of private billionaires and governments who might be interested. You may be able to lease access to the moon base to venture capitalists interested in mining precious metals from the moon. Private billionaires are often motivated, adventurous people, and maybe some of them will want to go too. They may see great opportunity in being in on the ground floor of the founding of a new planet. So if you could convince a few dozen of them to go along that could provides some funding too. [Answer] [Tracy](https://worldbuilding.stackexchange.com/users/270/tracy-cramer) [got it mostly right](https://worldbuilding.stackexchange.com/a/53064/863) IMHO. If you need a ship for 500 people, don't build it here and fight gravity to take it out; hollow out an asteroid and move in. [](https://i.stack.imgur.com/UEi9V.jpg) Called [Terrarium](https://en.wikipedia.org/wiki/Terrarium_(space_habitat)), this kind of space habitat should be fairly easy to implement: Capture an asteroid, bring it to Earth orbit, then proceed to drill until you reach a safe distance underneath - enough to protect an initial team from radiation. Instead of building structures on its outer surface, do it on the inside. If you keep the asteroid spinning, [centripetal forces](https://en.wikipedia.org/wiki/Centripetal_force) will generate something akin to artificial gravity on the outer layer. [](https://i.stack.imgur.com/q2sTV.jpg) You may build external structures with the material taken from the inside: [](https://i.stack.imgur.com/rWcPh.jpg) So your total cost to build a spaceship may be only the sum of transportation for the 500 individuals plus enough equipment (drills, 3D printers, solar panels, etc.) to get Step 1 started. Media sources: [Wanderers](http://www.erikwernquist.com/wanderers/), by Erik Wernquist; [Spacehabs.com](http://www.spacehabs.com), Bryan Versteeg. [Answer] > > I don't like the direction where mankind is going. We spend more resources to build tools which allow us to watch cat videos than on curing cancer. One day I decided to say enough, and leave this grim place. > > > As someone else has already observed, you do not actually want to leave the *planet*, but rather *the human race*. So an easier way out would be to e.g. try and escape *underground*. Most technical problems related to *living* underground are the same as those related to living in a spaceship, except when they're much easier: * oxygen can be pumped from outside, either regularly or in case of an emergency. * no fuel or propulsion issues. * artificial gravity is naturally supplied. * no risks of collision. The problem of making good your escape is the same (but somewhat easier; hiding a space launch is hard. You would need to first build a L5 colony, then move it into a cometary orbit and handwave your economic model possibly as asteroid mining, and finally install more propulsors and leave for good. Yes, that's Star Trek's [*The Galactic Whirlpool*](http://rads.stackoverflow.com/amzn/click/0553241702) by Gerrold). Of course there's still the problem of *getting* underground (technical and economical problem, but not the same scale as a generation ship), of *staying hidden* underground, and possibly to hide the fact to the people themselves, which requires careful geometry and may need mechanical gravity compensation to make the underworld go round (this is James P. Hogan's [*Endgame Enigma*](http://rads.stackoverflow.com/amzn/click/B002BI8EA2)) If you play your cards carefully you may engineer a generation-long "space travel" that will end up with the ship "landing" on a depopulated world which could still be colonizable, even if the previous tenants left it a mess: Sol III (you might even engineer the depopulation "accident" yourself to get rid of the lolcats). This is more like Hugh Howey's [Silo](http://rads.stackoverflow.com/amzn/click/B00CYNGPTG)). [Answer] What makes you think that the earth is not travelling in space right now? It just happens that you were born on a pretty big spaceship (earth) with a little over a few billion people on it. Check how the question come up... Where is it come from? Is it because you are bigger than the earth? Is it because you have access to more planets? How? Who are 'You' - the one who got the question? Keep the question. Don't answer. Seek the source of the question. [Answer] I would say step one would be to build an orbital elevator. using fuel to get up and down from orbit would be a huge waste of resources. next step would be to find how to use hydrogen to power devices and propulsion since Jupiter is way closer than inhabitable star system planets. so harvest hydrogen from Jupiter maybe using a similar system used to build the orbital elevator to build an orbital vacuum pipe because Jupiter's gravity is very strong due to it's massive size. sustainable life needs such as food and water would be your next step to solve. I think other answers here would be better at answering that problem Then I would say you'd have the building blocks u need. heck, you could maybe blow Jupiter up to get up to speed but that would require so many calculations to make sure you go in the direction of choice (although the force from speeding up will probably turn everyone into mush) So to use that method you would need some kind of impact dampening. like a long tube facing away from the explosion that would allow some of the force through and a hydraulic system to control how fast the cockpit/living area would move relative to the outer shell. [Answer] **Step 0**: Fund a space elevator. **Step 1**: Build the space elevator. **Step 2**: Make money with your space elevator. **Step 3**: Build your ship in geostationary orbit using your space elevator. The biggest cost factor for any space mission is getting it into orbit. And there is just no way around wasting tons and tons of fuel for each ton you deliver to low earth orbit. And that's only for low earth orbit. With a space elevator, you just get so much more efficient. But it's not just that you get efficient, you'll open a new, very cost efficient route to space. People will love it. And they'll throw their money at you, just to get a glimpse at the earth from geostationary orbit. Or to deliver payloads into other orbits cheaply and safely. Or launch missions to other planets from the far end of your elevator. With this kind of steady inflow of money, you can start building stuff that makes life in space easier. Start with some serious stations along your elevator, especially a huge one in geostationary orbit. The beauty is, that you can build step by step, with each step slightly enhancing the lifes of your guests, or expanding your resources to host more guests, host them for longer periods, feed them with space grown food, etc. Only when your ship is ready to leave will the rest of humanity realize that they'll be left behind... ]

[Question] [ It's a fairly common legend that trolls turn to stone when exposed to daylight, and I was thinking about using such a creature in a story. I'm searching for a plausible way of justifying such a weakness - there's nothing similar existing in nature that I know about. For background; I'm visualising these trolls as primitive, ape-like creatures that can grow to very large sizes. They are nocturnal / subterranean animals, and the sun is bane to them. They can move around on the surface at night, but in the daytime they have to take shelter under bridges or in caves. Direct sunlight is their big weakness. These trolls are like lobsters - they are biologically immortal and they will continue to grow for as long they live. The trolls keep on growing and getting larger until they can't support their own mass, or until they can't hide from the sunlight any more. When they die in the sunlight, their skin calcifies and they become rock. It's a slow and painful death; their skin turns to stone from the outwards inwards, until they finally crack apart. The very largest trolls might become mountains. In this world, there are lots of strange rock formations that have been left behind by dead trolls. It's possible that young trolls have resistance to sunlight and can operate in the day, but as they get older they lose this resistance. Young trolls are born in droves, but very few of them reach large sizes. So; biologically speaking, what could justify this fatal trait of trolls? I want to avoid just using magic as a reason, and I'm more looking for broadly feasible suggestions about how and why trolls might develop like this. Is there any deficiency, medical or evolutionary reason on why would sunburn would cause troll's skin to calcify? [Answer] Their skin contains a set of proteins that will bind to each other and harden when exposed to certain wavelengths, much like [dental composite polymers](https://en.wikipedia.org/wiki/Dental_composite): > > Composites are placed while still in a soft, dough-like state, but when exposed to light of a certain blue wavelength (typically 470 nm), they polymerize and harden into the solid filling (for more information, see [Light activated resin](https://en.wikipedia.org/wiki/Photopolymer)). > > > And from the link in the quote: > > A photopolymer or light-activated resin is a polymer that changes its properties when exposed to light, often in the ultraviolet or visible region of the electromagnetic spectrum. These changes are often manifested structurally, for example hardening of the material occurs as a result of cross-linking when exposed to light. > > > So they are not becoming actual rocks. Their skin are becoming a very hard organic material that has much the same properties as most kinds of rocks. Kinda like porphyria, but you become a statue rather than getting 3rd degree burns from sunlight. For more effect, rather than hardening on the skin, the proteins can break loose from it when exposed to sunlight. They fall in the bloosdtream and then harden within other tissues as well as the skin itself. [Answer] Another classic trait of trolls, is a tremendous regenerative ability. Sometimes to the point where only fire can kill them. So I'd suggest trolls create a chemical in their body that boosts their regenerative abilities, and any damage will increase the levels of this chemical. Sadly (for the troll) this chemical reacts with UV light from the sun, and hardens. Creating the resemblance of turning to stone. That could be an explanation for why only sunlight, and not other kinds of light (fires usually don't emit UV light) it also explains why they haven't evolved out of such a vulnerability, as they would loose their regenerative ability. It can be adjusted from only their skin turning to stone, and at night they can break free (loosing their skin, but it'll regenerate almost immediately) all the way to turning completely to stone (UV light can penetrate pretty deep, that's why we use sunscreen to not get cancer) [Answer] **The frozen troll is the second stage in a two part lifecycle.** Part 1: The troll is mobile, and goes around eating minerals to store in its body, and killing and eating animals (or hobbits) to sustain itself. It gathers and stores sperm from other trolls to enable it to reproduce in its sessile stage. The mobile troll focuses on growing, eating and generally causing havoc. It also carries dormant algae in its skin. Part 2: The troll is exposed to sunlight, which activates the algae on its skin. This triggers a biological reaction in the troll which causes it to rapidly harden into an armored algae fortress, by precipitating all the minerals it stored by eating rocks. The algae now live and thrive off sunlight and stored minerals, while enjoying the protection from herbivores afforded by the troll's frozen body. They produce lots of sugar, which is stored deep inside the troll. Most of the troll's cells die; however, the reproductive system is sustained by the algae. The troll-rock then can exist indefinitely, producing a steady stream of tiny trolls, which gather algae spores on the way out, then grow up and continue the cycle. Becoming a troll rock is incredibly unpleasant, as the brain of the troll survives while frozen in place until it starves as resources are diverted to reproducing. For this reason, trolls do their best to avoid getting frozen, but eventually they slip up and continue the cycle. [Answer] **Gypsum trolls** Trolls really are softies (literally) on the inside. As soon as a baby is capable of moving, troll moms pound gypsum with their clubs, heat it up, and roll them around in the resulting [plaster of Paris](https://en.wikipedia.org/wiki/Plaster#Gypsum_plaster). As they grow older, the old layers slowly crack, and more plaster is rolled on, giving the trolls a tough outer shell. As the plaster sets, it also cools, thus helping the massive creatures cool down. This is why the biggest baddest trolls spend all their time wallowing in plaster pools. Now, this isn't a problem -- trolls live in moist caves, by continuing to move and keeping the joints wet, they ensure that the plaster sets slowly, and only sets in desireable parts of the body. However, once they go outside in the sunlight, their eyes (so perfectly adapted to the dark) get blinded; making it hard to find shelter before the plaster sets into all their joints, leaving them immobile, dying a slow death. For added fun: gypsum also forms beautiful [crystals](https://en.wikipedia.org/wiki/Gypsum#Gallery). Trolls can "wear" these crystals either by sticking them onto still wet plaster or by encouraging crystal growth on their bodies. Hardened trolls look distinctive in the landscape: blinding white structures adorned with glittering multi-colored crystals. [](https://i.stack.imgur.com/SbG8N.jpg) Giant gypsum Crystals in Naica Mine, Mexico (See person for scale). Source: Alexander Van Driessche [Answer] Let's assume that trolls are unusual creatures, in that they consume and metabolize rocks, allowing them to access an abundant, yet generally low-competition material, as a food source. This is what allows them to grow to huge sizes, as they gradually assimilate more and more of their mountainous surroundings. However, it does come with a disadvantage: the chemical processes that allow them to integrate rock material in their organisms are expressed throughout the body and must continuously remain active in order to preserve tissue viability. Since trollkind has evolved deep underground and only in recent millennia has emerged to the surface through cave systems, their special metabolism is particularly sensitive to UV light. Once exposed to UV rays, even at low levels, a cascade reaction is triggered starting from their skin, turning the chemicals responsible with tissue viability into an inactive form. Without these chemical processes, rock material reverts to its passive, inorganic state and the troll quickly and painfully turns to stone, from the outside in. [Answer] ## Specific photosynthesis Trolls can continue to grow for as long as they live… I know another sentient being that have the same property: **Trees**. What if trolls were closer to trees than to animals? Yes, trolls evolved a lot since that time where they had roots instead of foots but they still share a lot with their ancestors… Especially photosynthesis! But trolls have a particular sort of photosynthesis, the **oxygenic photosynthesis**: CO2 + H2O + photons light energy → [CH2O] + O2 This reaction is pretty useful for them as they are living in caves where the CO2 concentration is very high! That’s the reason why this photosynthesis has to be very efficient: without it, trolls would suffocate in their lairs. But… There is not light in their cave so how is this possible? In fact, there is light in these caves: from fireflies and glowing mushrooms… And trolls have evolved in such a way that this tiny amount of light is enough for them to produce a lot of O2. So… When a troll is exposed to direct sunlight, the amount of light it takes is insanely huge for him and its photosynthesis reaction gets instantly mad!!! Problem : This reaction consumes water! Therefore, the troll is desiccated in a matter of minutes and the remaining corps just looks like a sort of mummy or a rock… By the way, this tree-affiliation and the photosynthesis would explain their green skin and their mossy look... [Answer] One aspect of common sunburns is the body's inflammatory process. Perhaps the biology of your trolls is such that their inflammation redirects calcium from their bones to the surface of their skin, where it merges with their skin cells to calcify it. Then, like a hemophiliac response to a bruise, hemorrhage or cut, the process continues in a runaway fashion until their whole bodies are turned to "stone" (or bone). Your trolls would need a large supply of calcium for this to make sense, so they should have especially large, thick, and dense bones. [Answer] You might also consider why they would react to light by turning to stone. My suggestion would be as a defense mechanism against some other type of creature that produces light. The troll's skin turns to stone as a defense against that creature. After a few nights, the stone skin would slough off and allow the new skin under it to grow out. Assuming the attacking creature uses a reddish, long wavelength, the problem with sunlight might be that it includes a more penetrating short wavelength ultraviolet light. This penetrates into the interior of the troll, turning the organs and muscles to stone. Trolls might be naturally somewhat translucent in strong light, although most people never get a chance to see it. An alternative would reverse things. Instead of light being the issue, the real issue is heat. It's the heat from the sun that turns the troll to stone. As more and more heat is transferred, it effectively cooks the troll from the outside in. Heat of course can be conducted through stone, unlike light. This of course would also allow adventurers to set trolls on fire to turn them to stone. I'll leave it to others to explain how the conversion to stone occurs. I'm just trying to explain why it would evolve. [Answer] > > So; biologically speaking, what could justify this fatal trait of trolls? > > > I'm more looking for broadly feasible suggestions about why trolls might develop like this. > > > It's an accidental feature. (I'm going to assume polymers hardening in the skin is what causes the solidification as per other posts, and add the possible reason the trolls have survived while still being sensitive to light.) Originally trolls grew up in the earth, where sun would never reach. Trolls would die frequently when young, so they never got programmed to stop growing, even though this would be a major defect in a small space underground. Call it a side effect of high breeding potentials, they grow fast and loose. Sorry, anyways these small cave dwellers eventually get better at surviving longer, until some of them are large enough that they start to migrate more, looking for bigger passages. Some will get stuck and die, but others will find big places to live, and still others will reach the surface. Of course, as soon as the sun shines upon them their skin starts to harden, so they quickly learn to avoid it, and those who are better at avoiding it can even live on the surface. But that can also be a risk that potentially ends with them being turned to stone/hardening polymer/whatever. Point being, sometimes evolution is more of an art than a science, and not every creature is the best adapted for new environments. [Answer] It doesn't need to be a *natural* feature in order for it to be non-magic. It could be the result of genetic engineering. In the distant past, trolls didn't have this feature. But, some trolls enslaved others to work underground in mines. The trolls that were slaves were genetically modified so that they calcified when exposed to sunlight. This limited their ability to rebel. Eventually, a surface catastrophe (e.g. asteroid impact) caused the surface trolls to become extinct. The former slaves emerged from the mines and found that they could get by just fine at night but would die if caught exposed to sunlight during the day. They have been that way ever since. Since they are well-adopted to a nocturnal life there hasn't been sufficient genetic pressure to remove this engineered trait. [Answer] Declare trolls to be immensely specialized to their lifestyle. Everything about them is fine tuned like a shark, so that they can reach unbounded sizes. Its not easy to design a creature that can function at utterly any size, so you're going to have to give up some flexibility in terms of the environments. Some environments are simply inhospitable to what's left after you focused on unbounded grown for that long. So the trolls have a natural solution. If they find they are in any environment which is not suitable for troll life, they go into defense mode. They literally freeze in place, and wait for the environment to change. It's a similar response as we see in armadillos, which curl up into a ball in response to a predator and wait for the predator to go away. For the most part, this is effective. If a proto-troll, earlier in their genetic history, were to get caught out in the sun, this freezing-stone-form effect would keep them safe until the sun went down and the environment was once again troll friendly. It was very useful from an evolutionary perspective. Now what people don't know is that trolls are rather sensitive emotional creatures. They have developed a level of empathy which we can only dream of. And, as such, it is emotionally painful to lose contact with the outer layers of the skin as they enter stone form. As such, inner layers may also turn to stone, in an attempt to avoid the sadness from the loss of contact. Old trolls eventually develop this empathy so greatly that when the outer layers of their skin freeze, they try to hold onto them so hard that their inner core eventually freezes as well. And this leaves you with a stone troll, forever marking the moment in time where they just couldn't let go. [Answer] You said you want to avoid *just* using magic as a reason, but maybe it would provide an interesting additional layer in your story if you gave the facts a mythic explanation as well (that perhaps your characters grapple with by contrast with the scientific explanation). So here goes: Trolls were not part of the rest of creation but were the work of a rebellious power, one opposed to the power responsible for the sun. With normal creation, the sun has a purifying effect that causes the creatures to regenerate and the plants to thrive, and killing off pathogens: a system set in place during the original creative work. But because trolls didn't come from that work, the sun's purifying function is against them. So, just like a virus or a bacteria can't survive under UV exposure, neither can a troll. ]

[Question] [ Making vocabulary for a language isn't too difficult (at least, not as hard as it might seem at first!). You can come up with some simple patterns of letters and syllables, and work off of those to create myriad words. One problem I encounter is that even if I come up with a good system of vocabulary, the *structure* of my language is always fairly similar to English, my native language. Here are some of the specific structural bits that I subconsciously insert (answers don't have to cover these; they are simply examples): * Word order * Conjugations and declensions * Adjective-noun agreement * Subject-verb agreement I know that most observers won't necessarily notice this, but I'd still like to make my languages as alien as possible. So, how can I make my languages structurally different from English (or other Earth languages, for that matter)? See also [Are there techniques for creating alien or foreign sounding names?](https://worldbuilding.stackexchange.com/questions/3478/are-there-techniques-for-creating-alien-or-foreign-sounding-names). [Answer] **Get to know other languages** as that will give you a good feel for how languages can be constructed. The Frankfurt International School has a set of pages that describe the differences between [English and many other major languages](http://esl.fis.edu/grammar/langdiff/). These pages are written in English and discuss alphabets, phonologies, grammar and tenses. Familiarity with other languages will help considerably when coming up with new languages because new features can be borrowed. **Subject-Verb-Object** Changing the order of the **S**ubject, **O**bject, and **V**erb around will the desired effect. Wikipedia has a [huge list](https://en.wikipedia.org/wiki/Subject%E2%80%93object%E2%80%93verb) of how language construct their sentences. As a stylistic choice when translating for the reader, just translate the words into English while preserving the Subject-Object-Verb ordering. This will help to emphasize the "foreignness" of the language. **Conjugations** Developing your own [verb conjugations](https://en.wikipedia.org/wiki/Grammatical_conjugation) can be tedious but thankfully, most languages use the same conjugations for most verbs. Some verbs are taken from other languages and those older conjugations have remained instead of following the standard. Note that conjugations are based on a particular dimension of importance to the culture that the language came from. Wikipedia gives a list of common conjugations: > > person, number, gender, tense, aspect, mood, voice, or other grammatical categories. > > > A language can be made very weird by ignoring some or all of these dimensions *or* incorporating a dimension that isn't on that list. Ignoring past and future tenses can give rise to such cultural oddities as the [Piraha people](https://en.wikipedia.org/wiki/Pirah%C3%A3_people) of the Amazon. They have no concept of anything that doesn't exist in front of them, right now. **Cultural Features** Remember that every language comes from a specific culture and that culture will emphasize or deemphasize a given language feature. A culture obsessed with the past may have verb tenses equating to "just happened", "yesterday", "last week", "last year", "beyond human memory". [Answer] I add this answer mostly for completeness, since other answers are already great. First of all (as it has been extensively said), knowing other language is a great way to get inspiration. However, you will have to study quite strange language to get totally different structure. For example French and English are not so different in their structure. Most of the time you can just put the words in the same order (I can relate as a native French speaker). But you have to consider that a language is not only a vocabulary and a structure. [Here](https://www.youtube.com/watch?v=GAgp7nXdkLU) is a video from Tom Scott explaining why. For example, there is correct and meaningful sentences that nobody use, because... well because that not how you should say that. If you translate brutally the sentence "My name is Kolaru and I am a native French speaker" ("Je m'appelle Kolaru et ma langue maternelle est le français") from French, you will get something like : "I call myself Kolaru and my maternal language is French" I am not sure it is understandable, but it the structure and vocabulary are correct. However, you do not say it that way. You can use such concept to make your language strange, just by changing the usage of words (in the example we can see that in French you communicate your name using yourself as subject and your mother tongue using it as subject, when in English it is the other way around). One other thing is that some concept can exist in a language but not in all (see [this video](https://www.youtube.com/watch?v=QYlVJlmjLEc)). As mentioned by Green the concept of time can be absent, or the concept of individuality, or any other. You can perhaps go a step further, by excluding grammatical concept. Perhaps there is no concept of ordering the words in a sentence (this is the case to a certain extend in Latin : since all word are conjugate according to their function in the sentence, there is no need for an ordering). Perhaps there is no concept of adjective, a black hat is considered an other noun as a white hat. Or no concept of active verb, and you refer to somebody doing an action by categorizing the person, for example : "Billy is being a walker in the forest" to say that "Billy is walking in the forest". In conclusion there is plenty of way to make a structure of language looks alien, and if you thing about an idea "that is crazy, no language can work that way", first you probably are wrong, second you are getting closer to a language really looking strange. [Answer] My best advice is to study the structure of other languages. I believe you already mentioned you had a basic knowledge of Spanish. For me, some sentences or words in English sounds misconstructed because it's not my native language. I will take examples from 2 languages that I know : French and Mandarin Chinese **Summary: try to find something that will have no equivalent in English. Something that has no meaning in your native language, cannot be translated or only with great difficulty.** **Some Chinese** * In Chinese, traditionally, they didn't use the interrogation mark "?". They instead either use the particle (pronounced "ma") or have to repeat verb of the question. Note that, not all questions will have this structure, there are other possibilities. If I ask : Do you speak Chinese? One way to ask: **Nĭ shuō hànyŭ ma**. (Ni=you / shuo=speak / hanyu=chinese) It makes no sense without the ma. The other thing is the repeating verb: **Nĭ shuō bù shuō hànyŭ.** Bu is for a negation. Which translate into: You speak, do not speak Chinese? It certainly sound weird when translated directly in English. They can also ask questions without the 2 things mentioned above two such as in: How is your Chinese? **Nǐ de hànyǔ zěnme yàng**. * Chinese use a load of particles for everything. Notice that the particle "de" in my example before refer to **your** Chinese (language). If I want to say : One country = **Yī gè guójiā** Yī=one / guójiā=country / gè=it's hard to explain what it means but it's generally an unspecified unit used between a noun and a number. If you don't know what to use, just put gè, that is just what 5 years kids old do in China apparently. But somtimes, some words will require a specific particle. One book= **Yī běn shū.** Book has its own particle to specify the quantity. And there is no need to have a word for this in English. * Chinese don't have verb tense to conjugate! This is so difficult in French, Spanish and even English. Form example, they will use the particle "le", at the end of a sentence to indicate past events or a recent change. They use other ones but I don't have any that comes to mind. Example You have money now. **Nǐ yǒu qián le**. (you=have) **French:** French uses something that anglophones have a really hard time to understand : determinants. it's not something unique, other language like Spanish also have this. Example: The table (English) = La table (French) but The telephone = Le téléphone It's easy as breathing air for native speakers but seems to make no sense for the anglophone since they don't have a word for this: they always use "the". In French, table is feminine and telephone is masculine. Yes I know they are all made of plastic, but it's like that. [Answer] You can take an existing language, the most different from English you can find. Then use its grammar as a base and create a new vocabulary. The [World atlas of language structures](http://wals.info/chapter) is a good source for your work. It basically a database about languages and grammar. A bit difficult to navigate, but full of information. If you scroll through the "Chapters" section, you can find interstings ways to add originality to a language (like non-sex-based gender system or adjectives without nouns), a see which existing languages have each of these features. The [Languages In Danger](http://languagesindanger.eu/book-of-knowledge/) website is also interesting. It has a map of languages, a chapter on languages structures, information on the relation between language and culture, and other stuff. It focuses on endangered languages, but can be used as an inspiration source. [Answer] **Disclaimer:** When I worked in natural language processing, I wanted to get some intuition on what kind of structures would be parsable, i.e., the recipient could understand them with some varying degree of difficulty. Thus, I created a number of artificial languages just to see how it turns out in practice. So it happens, a lot of them seemed quite alien, but still had some unifying features. What follows below are some quick conclusions drawn from the ideas back then—some might ring true, other may be just plain wrong. **On compression:** There is one not really surprising characteristic of communication: it tends to get compressed. On average, as long as they are understandable, shorter phrases win. To give you some examples, for example we use "I'm" instead of "I am", there's "gonna" or "I'd" which can mean both "I had" and "I would". Observe that the most frequent words are short, and longer words are rarer—like an evolving [Huffman coding](https://en.wikipedia.org/wiki/Huffman_coding) algorithm. It might be quite obvious, but it has great ramifications. To give you some concrete examples, it might be one of the reasons behind * structures like "I ate an apple and a banana." rather than "I ate an apple and I ate a banana.", or even more complex like "I gave a teacher an apple and a policemen a flower.", * dropping subject, e.g., "Give it to me!", * multiple other omissions, e.g., "What a stupid!", * popularity of pronouns, e.g., "He did this." instead of "Nabuchodonozor did this." The thing is, in my opinion, any alien language will also obey this law, after all, communication is an expenditure of energy. Moreover, there is a well-known tradeoff between complexity and compression, and understanding/processing what the other person said is also costly. Thus, certain constructions will be preferable both in human and non-human languages. Also, aliens of lesser intelligence might use more verbose language, smarter creatures will use more complex structures. Here I'm using "more verbose" or "complex" from the alien perspective, that is, their brain might be constructed in a way that makes some things trivial while other troublesome. To give you a funny example "The rat the cat the dog chased escaped." might be a valid and short sentence of English, but it would be easier for humans if expanded, still it could be easy for an alien who starts reading in both directions (left->right and right->left) simultaneously. In short, in my opinion information theory matters to aliens too and you need an in-story reason to break its principles (and I don't think it is worth it). **On linearity:** If your aliens communicate with sound, then there is a great chance that their language will be linear. On the other hand, although it might be unfeasible to transfer arbitrary 2D structures this way (for any living creature there is a limit to a precision it can distinguish harmonics), it could be multi-channel transfer. In fact humans do it already: * mimics and gestures, * emotion in the voice, * emoticons (it's quite rough, but you *can* think of it as a separate channel). To make the language more alien you could incorporate some more channels that would transmit some alien-characteristic meanings of the sentence. **An example:** In fact, one way to make a language alien is to just dump the whole linear structure thing. Here is a sketch of the idea behind one of the languages I constructed at the time. We start with no word order, and the structure of a sentence is driven by inflections. However, instead of the usual inflections, we make them more abstract: just for now, let's suppose that each word has a prefix with an identifier of its parent in structure, and suffixed with another indentifier that can be used by its children, for example "I ate an apple and a bannana" could be written as (the root and leaves have only one identifier). > > 3\_I\_ \_ate\_3 4\_an\_ 5\_apple\_4 3\_and\_5 6\_a\_ 5\_bannana\_6 . > > > [](https://i.stack.imgur.com/Xqh1V.png) > > > or equivalently as > > 6\_a\_ \_ate\_3 4\_an\_ 3\_I\_ 3\_and\_5 5\_bannana\_6 5\_apple\_4. > > > or a bit more succinctly (the "and" is unnecessary) as > > 3\_I\_ \_ate\_3 4\_an\_ 3\_apple\_4 6\_a\_ 3\_bannana\_6 . > > > Now, the information theory comes and spoils the fun (although not all the fun), because: * the word order is additional information that is right now just thrown away, to this end we use the word order for emphasis. * structures like "3\_a\_6 6\_bannana\_" are quite inefficient, instead we have special prefix and suffix for that case and similar others: next word, previous word, parent of the previous word, grandparent of the previous words, etc.) e.g. > > 3\_a\_<next word> <previous word>*banana* (a banana) > > > nw\_I\_ \_ate\_2 pw\_apple\_ pp\_banana\_ pgp\_went\_3 pw\_home (I ate [an] apple and [a] banana and I went to home) > > > * the above also make some word orders more preferable * identifiers like 1, 2, 3 carry too little information, instead we should use something meaningful, for example syntactic like <subject>, <object>, <object2>, <verb>, <verb2>, or perhaps semantic like <action>, <beneficiary>, structural <root>, and so on; we resort to <token\_42> very rarely > > \_ate\_r v\_I\_ v\_apple pw\_an v\_banana pw\_a > > > * all the prefixes and suffixes should easily merge with the words into just a few sounds, the language should flow and be easy to pronounce (from alien perspective). There are many more nuances here, but I will stop now, I think you will get the idea. There is one more final ingredient, after some phrases become very frequent, the boundaries between words and identifiers will blur and some expressions will become words on their own. Although such a language will be most probably [agglutinative](https://en.wikipedia.org/wiki/Agglutinative_language), it is bound to have certain irregularities, fusions and other quirks. For any language you construct, before it's ready you have to make it alive, even for a moment. Let it evolve for a bit, in your head, or when discussing with a friend. After that, you will need to redesign it a little, fix some flaws, but then there will be some spirit in it. **Closing remarks:** So that's the example, I hope you like it. There are myriad of ways you could combine it with other features (like the multiple channels). However, please don't make an overkill. Not all the readers/viewers/whatever will be as smart as you, and very few (if anyone at all) will dive deep enough to understand and appreciate such a language. If you make it really alien, it will just confuse them and it might negatively impact on your story. In particular, even if the language is alien, the audience might feel quite good about themselves, when they will guess the rough meaning of an untranslated phrase based on a few previous usages. It might make for a fun, subtle spoiler and perhaps a nice [Chekhov's device](https://en.wikipedia.org/wiki/Chekhov%27s_gun), but won't work if the language is too complex. I hope this helps ;-) [Answer] When I was learning French in school, I liked to compare the differences between it and English in terms of efficiency. For instance, many French adjectives come *after* the nouns they describe; I liked this, because if you're trying to explain something while dying, you should probably say the nouns first, as it'll be easier to infer the adjectives if you can't finish the sentence. What I've taken from this is that languages are built to perform certain functions, and some are better at certain functions than others. Thus, if you want to create your own language, you should decide what functions that language does best. You're always going to have nouns and verbs, and these are always going to have some modifiers. But the order really is up to you. For instance, let's say you have an aggressive alien race; they might start each sentence with the verb. ``` Always going to have you're nouns and verbs, and always are going these have modifiers some. But is the order up to you. For instance, let say us have you an alien race aggressive; might start they with a verb sentence each. ``` Now, unless you've accidentally copied some other terrestrial language (or Yoda), you've got a new, alien structure. The next step is to deal with those little articles and other such syntactic sugar. Don't like a, an, and the? Turn them into prefixes! Don't like tense suffixes? Turn them into words! Again, these decisions could be based on the culture of the aliens you're trying to make, and what kinds of information they're trying to convey with the most clarity. The last step (that I can think of) is punctuation. In English, we speak sentences differently based on the little symbol at the end. In an alien language, ending punctuation could be at the beginning, or could apply to individual parts of sentences (maybe the subject gets one tone, and the object another). There could be contractions in places English currently doesn't allow (like those tenses you turned into words, maybe future generations didn't approve). The way your language is punctuated could be based on the previous rules you've set, or on culture again, or even on the structure of the alien's speech organs. For instance, if it's a species that breathes a lot, there should be a lot of commas. At the end of the day, you're only limited by the fact that the language has to make sense. Try to avoid cases where sentences are ambiguous, though even in English we have that problem (alternatively, instead of avoiding ambiguity, you could embrace it and come up with some great alien jokes). Make sure that the kinds of things your aliens like to talk about can be discussed easily. [Answer] Most of what I wanted to write has been conveyed in some form by all the previous answers. Nevertheless, I thought I could add some summary and complement. What constitutes a languages? Well the vocabulary, of course, as you mentioned, but not only. The grammar as well. And at the end, it is a complete mind process that is translated in a way to express oneself. If you want to get a different feeling that English, you have to think that English sentences and more importantly words are pretty fixed. You rarely get away from the typical > > *Subject + Verb + Complement* > > > and the nouns as well as the articles or even verbs barely change depending on other words. So you need to introduce all that to reinforce the feeling of strangeness to English speakers. As the others, I would say that the first step is to know other real-life languages. Which features do they have, and why and so on. But let us introduce some concepts which might get immediate changes to the feeling of your conlang. **Conjugation** Verbs are quite fixed in English, with basically three tenses, and in most, only a change on the third person singular. Think about Spanish, where every variation within a tense has to be clear enough to omit completely the pronoun as a subject. > > [yo] com**o**; [tu] com**es**; [el/ella] com**e**; [nosotros] com**emos**; [vosotros] com**eis**; [ellos] com**en** > > > And adding some more variations with tenses: one or more future, one or more present, two-three pasts forms. And different [moods](https://en.wikipedia.org/wiki/Grammatical_mood). For example, French and Spanish have 4 of them. **Declination** That is known from Latin, Russian or German. Depending on the position/function of the nominal group within the sentence, the words change. For example, in German > > de**r** Tisch (*Nominativ*), de**s** Tisch**s** (*Genitiv*), de**n** Tisch (*Akkusativ*), or de**m** Tisch (*Dativ*) in [German](https://dict.leo.org/ende/index_de.html#/search=tisch&searchLoc=0&resultOrder=basic&multiwordShowSingle=on). > > > German is quite simple in this, but from what I know of Russian, they have more cases, and worse, similarly to other slavic languages, they have declination depending on the gender (male/female) of the subject and/or the number. Japanese and Korean have some forms of declination (I am not sure what's the best word for it) to indicate the politeness, or the level of respect given to the interlocutor.1 **Mutation** Some languages have mutations. This is due to the fact that pronouncing the words as they are can be quite difficult. To get an idea as English speakers, when indicating a possessive form of a plural word, you often omit the second "s". Like > > The **Smiths'** house is the one over there. > > > The "correct" *Smiths's* would result in some complex expression. Some languages go further and actually change the letters. > > In Breton, ***k**iger* (= Butcher) gives *ar **c'h**iger* or *ar **g**igerez* (= the butcher) depending if its a male or a female person. > > > **Position of the verbs** The order of the words may vary. For example, in English, there are many verbs with particles. For example, > > make, make out, make up > > > have completely different meanings. Nevertheless, the verb and its particle tend to stick quite close to each other. This is, for example, not the case in German, where the particle is sent... at the end of the sentence. > > *making **up** an excuse on my way to work* becomes *making an excuse on my way to work **up*** > > > And this has an effect on conversations. Indeed, the verb is the most important part of most sentences. That is the one which carry the meaning. If you can't grasp the meaning of a sentence until the very end, you are forced to listen to that person until then. Whereas Romance languages speakers tend to interrupt each other much more frequently. Japanese is similar to German for that having their verbs always at the end of the sentence.2 **More grammar words** It was mentioned in an earlier answer, but French, Spanish, and other have a much larger variety of determinants and linking words. But to illustrate this concept, I would use Japanese as an illustration. > > わたしはアメリカにいきます。I/me-*wa* USA-*ni* go = I go to the USA. > > > They have some particles to indicate the grammatical function taken by what precedes. *wa* indicates the subject. *ni* the destination of the verb to go. **Shuffle around** The use of such extra words allow Japanese to move nominal groups around. Their function being indicated by the following particle. Other languages do the same. For example, in Breton > > Pesked a zebran alies > > > Alies e tebran pesked > > > Debrin a ran pesked alies > > > all mean the same thing (I often eat fish), but the order of the words is moved around. The main idea, is that the emphasis is placed upon the first group. So depending on the intention of the locutor, the whole sentence looks pretty different. All those are somewhat simple rules from real languages that could be included to make the sentence sound less English. 1: Most languages I know have some form of politeness in it. But contrary to, e.g., Japanese and Korean, they merely choose a different subject and do not change much more than that. Yet English lost that distinction with the now deceased thou/... 2: In German composed modals, or composed tenses also send more than just the particle at the end of the sentence. [Answer] If you want to make a language that truly sounds *weird*, try messing around with what grammatical bits and pieces are and are not required. `This is ___ main reason why Russian speech sounds strange to ___ American ear: ___ word "___" does not exist in Russian.` [Answer] In addition to the other great sugggestions here, I want to point out that changing the morphological structure of your language can be a big help. English has a very distinct morphological structure, so copying it too closely can make your languages seem English-like even if the phonology is very different. Languages generally fall somewhere in a spectrum between synthetic and analytic. More synthetic languages tend to express grammar with morphology—they add affixes and mutate the structure of words. In English, the plural is expressed synthetically—we add a suffix (*s* or *es*) to the base word to make it plural. The past tense is also expressed synthetically; we add a suffix *-ed* to regular verbs to make them past tense. Languages on the analytic side like to use syntax and extra words to express grammar. In English, we express the nominative/accusative distinction analytically; in *The man loves the girl*, *the man* is the subject, so it appears before the verb, while *the girl*, the object, comes after the verb. Some languages express this distinction synthetically, e.g. Latin *Vir puellam amat*—the suffix *-am* on *puella*, "girl", marks it as accusative. Synethesis can also be divided into two types—agglutinative and fusional. In agglutinative languages, distinct concepts are expressed with distinct morphemes. E.g. in Japanese, "I read" (lit. "read") is *yomu*, "I can read" (lit. "can read") is *yomeru* with the suffix *-eru*, and "I cannot read it" is *yomenai* with the suffixes *-eru* and *-nai*. Notice how the separate ideas "can" and "not" are expressed with separate suffixes that stack up, sometimes causing phonological changes as they do. (The truth about Japanese grammar is far more complex, but I won't go into it here.) In fusional languages, several grammatical concepts will be bundled into a single affix. E.g. in Spanish, *Hablaron* means "They spoke". It comes from the root *habl-* and the suffix *-aron*, which means third-personal plural preterit (a type of past tense). This suffix has no internal structure to it; there isn't a piece that means "third-person", a piece that means "plural", and a piece that means "preterit" like there was in the Japanese example. (Note that the preterit tense also conflates several different concepts, but I won't go into that here.) English has a very distinctive character even among European languages: it's very far to the analytic side, but it retains these little bits of synthesis, as we see in the plurals and the verb tenses, and usually tends towards fusional rather than agglutinative. Most European languages are more synthetic than English—some just a little (French, Spanish, German), some drastically so (Russian, Lithuanian, Greek). Among world languages, Chinese and Vietnamese are even more analytic than English, while many languages are more synthetic. European languages tend to be fusional, as do the related Indo-Iranian languages (Hindi, Farsi, Sinhalese). Turkish, Japanese, Korean, and many Native American languages are more agglutinative. If you'd like to read more about this, Mark Rosenfelder's Language Construction Kit, mentioned in an earlier comment, has a great explanation. [Answer] It depends how alien the aliens are. For example, supposing they are utterly logical and have an enormous short-term memory. Then they could use something akin to some computer or mathematical constructs. For example: > > A Post canonical system, as created by Emil Post, is a > string-manipulation system that starts with finitely-many strings and > repeatedly transforms them by applying a finite set j of specified > rules of a certain form, thus generating a formal language. > > > Post canonical system From Wikipedia, the free encyclopedia > > > <https://en.wikipedia.org/wiki/Post_canonical_system> > > > I think you need to specify first what the alien brains are like and how the aliens think. Then you will be able to depart from humanising their language. [Answer] While it is not specifically about aliens, I think the book "The Languages of the Pao" by Jack Vance might be an interesting read for you as it constructs a world where the Sapir–Whorf hypothesis (or linguistic relativity) plays a central role. The strong version is used here, which states that language shapes thought. The book describes how giving different groups of humans different artificially constructed languages changes the way those groups think and behave. For example, a language constructed to emphasize overcoming adversity, strength and military success shapes the group that uses the language to be soldiers. An example of an English translation of this language (paraphrased and from the top of my head, it has been a while since I last read the book) could be: > > Alice overcame the the hardness of the tree with fierce swings from her axe. > > > Instead of the neutral: > > Alice chopped down the tree with her axe. > > > Imagine that a language would not allow the simple and neutral form, but put everything in terms of winning, conquering, enduring, et cetera. Other example from the book include a trader language that emphasized honorifics and contracts and a technical language that emphasized precision. I believe illustrations like the above might help you make the a language more alien by incorporating the concepts that the aliens find important, as other answers have mentioned, heavily into the language. Unless creating an alien language only needs to look alien of course, and the English translation of what it conveys is not important. Another thought that I am certain I have read in another SF or fantasy book somewhere is a language that solely consists of references to stories/legends to convey meaning. This might also make your alien language very strange to human ears if taken to the extreme. [Answer] I'm going to refine the "study other languages" suggestion in many of these answers: study *one* other language and learn how it works. Your language will sound more plausible if you didn't take "one from column A, one from column B" when considering word order, conjugation, declension, aspect, and so on. But on the other hand, since most of your readers probably won't *know* the language you chose, you can copy elements and still seem "foreign". Pick a (non-Romance) language and look for a grammar that explains it. (If you're weak on formal grammar you'll want to work on that first.) If you get lucky you'll find a book that explains how the grammar works *as compared to English*; I found [such a book](http://rads.stackoverflow.com/amzn/click/0801046947) when studying Hebrew. You don't actually need to learn a lot of *vocabulary*; after all, you're going to make your own. But learning a little will help you understand the grammatical principles of that language. If you're not a linguist or already multi-lingual, I would stop here and construct a language *modelled on your exemplar*. Yes, it'll be (say) Bulgarian with the serial numbers filed off, but you won't have to invent *every* aspect of the language yourself. If you need to adapt the language because, say, your aliens have three genders and your language is gendered, then go ahead and so something that feels consistent to you. As you work more with your invented language you'll probably get more comfortable with making minor tweaks. You probably don't want to completely *change* how you, say, construct prepositional phrases, but you can (a) introduce minor variations (in English there are lots of ways to say the same thing; why not in your language too?) and (b) build out stuff that you didn't do much with initially. [Answer] Take as your model one or more "non-Western" languages (Asian or African). Most of them are very different from English. The problem with using European languages is that English is derived from either Germanic or Latin languages, and most share features with English. The European group of languages least like English is the Slavic languages. [Answer] Note that language is more than vocabulary and grammar. For example, I've been told that in Korean, you use different words for the same things, depending on to whom you speak. In Chinese, the pitch plays a role in the meaning, with the result that you cannot accurately sing Chinese text; the melody interferes with the correct pronunciation. So you see, there are many ways to make your language alien. For example, maybe your aliens consist of two "classes" or "castes", who use slightly different language. Maybe the upper class uses gender forms (I mean, pairs like "actor"/"actress") only when speaking about members of their own class, while using a completely different, gender-neutral form when speaking about lower-class people. The lower-class people use the same gender forms for upper-class people as the upper-class people use, but also use gendered forms (but different ones) for people of their own class. For animals, both classes use only the gender-neutral forms. If they want to specify whether it's a male or female animal (or, for upper class people, a male or female lower class person) they explicitly say e.g. "male cat"/"female cat" (except, of course, using words from their own language). This latter, constructed example also shows how social aspects can influence language. That the upper class uses the same genderless form for lower-class people which they also use for animals shows how they see (or historically have seen) the lower class. The differences in the language also codify that movement between classes is probably hard, if not impossible. But also in terms of grammar there's a lot of room of doing things differently. For example, we are used to signify the tense by the verb. But who says this has to be the case? The tense could just as well be put on the subject, so that instead of saying "The dog barked", that is "The dog *barks in the past*" you say something like "The doged barks", that is, "*The dog in the past* barks". Thinking about it, the formulations I used as explanations also are examples of an alternative way to form tenses. Also, maybe the alien language doesn't have our types of words (i.e. nouns, verbs, adjectives, etc.). Maybe they have only nouns and adjectives, and a form of "to be" is implicit. For example, instead of the verb "to bark" they'd only have an adjective "barking", and "the barking dog" is a complete sentence meaning "the dog barks" while "the brown barking dog" means "the barking dog is brown", while "the brown and barking dog" means "the dog is brown and barks". The hoping me, helpful thised. [Answer] Some remarks: 1. If I were creating a language, I'll make grammar simple and take the inflection of English (that is, analytical), except for tenses (do we really need 12 (at least) tenses?), so maybe more like Chinese. However, if you're more keen on complexity, you may check out [Ithkuil](https://en.wikipedia.org/wiki/Ithkuil), a constructed logical language with great multitude of sounds and inflection categories (by Wikipedia article, the number of cases alone is 81, and there are 153 inflecting affixes). 2. Some answers are about getting rid of natural categories, like verbs, which happens in some conlangs. Apparently, it also happens *in vivo* – look for [Riau Indonesian](http://lmgtfy.com/?q=riau%20indonesian), which is even called *grammarless*. Oh, and it seems to lack second person as well. 3. However, maybe introducing more categories than usual would be more exotic? E.g. (with distinct inflection): animate nouns, inanimate nouns, abstract nouns, verbs of state, verbs of action, verbs without apparent agent (as in 'it rains', 'it is cold', 'it seems'). [Answer] While not wholly centered around story, this article captures some of the methods used for the [alien writing in Infinifactory.](http://www.gamasutra.com/blogs/ZachBarth/20150724/249479/Creating_the_alien_writing_in_Infinifactory.php) It may be an interesting read for you. Furthermore, to directly answer your question; If you want to make a language that is structurally non-english, you need to break the rules of english. In this sentence, for instance, I use commas to separate words, and the word 'and' to separate ideas. In your language, you may not use them at all, or add a 'iqu' to the end of words that are part of a series. An example: I have a cat, a dog, and a fish. Would become: I have catiqu dogiqu fishiqu. If your language is different enough, the addition wont look so strange. J'dani de zatiqu bakaniqu ghotiqu. Furthermore, you can make sure that there is no one-to-one comparison of words, unless necessary. So instead of a word for airplane, you'd use 'sky' and 'wing' together. tl;dr: Break the rules, they're more like guidelines anyway. [Answer] This might be not exactly an answer to this question. It is just a complement over other answers here. To make your language the most alien-like, lets try to get its syntax as the most unheard, strange and unnatural for humans. Natural human languages have things like nouns, adjectives, pronouns, verbs, etc. What if you have a language where one or many of them are completely absent? I really can't think how something could be without nouns. So, let's see if we can take out everything else and keep only the nouns! Instead of *"Attack them with the lasers"*, let's use something like *"Hords lasers enemies"*. The order *"Hords lasers enemies"* also follows the temporal ordering, first we have the hords, them the lasers and then the enemies. Although English allows *"lasers"* to be a verb, I am intending that it is a noun. Applying it to something more complicated like *"The dog happily chased the yellow cat in circles"*, we can have it as *"dog happy cat yellow prisioner foot external also repeat circle"*. Where *"prisioner foot external"* means "*to flee*" and then *"prisioner foot external also"* is "*to chase*". This complex phrase is expressed entirely without any verbs. To make it more alien-like, lets instead reverse the time order. So we have *"enemies lasers hords"* as "*Attack them with the lasers*" and we have "*circle repeat also external foot prisioner yellow cat happy dog*" as *"The dog happily chased the yellow cat in circles"*. Human languages flexes words by number (plurals), genders, size, time, etc. We can either take out all of those humanly flexions and instead use something more weird, like: * **Color**. So blue thing flexes in a way, red in another way, also for green, orange, pink, purple, black, gray and white. Also aliens have a vision very different than humans although still biologically plausible (with anything from mid-infrared to soft x-rays), so we can also have infrared, ultraviolet and x-ray and combinations that makes no sense for humans like color *J* that is "a mix between soft x-ray and yellow", color *K* that is a "middle-infraredly pinkish green", color *L* that is an "brown-cyan graying-near-ultraviolet with a bit of near infrared"... Also, since they have a much larger visible spectrum than humans (not necessarily in a single range), they might be able to see trillions or quatrillions of colors, so this might ended being very important in their language structure. * **Textures**. With the big number of colors that they may be able to see, it is imaginable that we might have some complex visual textures. So things might flex if it is transparent, opaque, bland, checkers-boarded, chaotically random, gradient, striped, wavy. * **Shape**. Words for triangular things flexes in one way. For square things in another. Same for hexagons, cubic, pyramidal, spheric, rod-shaped, tree-shaped, spider-shaped, wavy, straight... * **Person or thing job**. So, we can have words flexing differently for workers, kings or royalties, gods, unemployeds, criminals, children, working machines, broken machines, hollow objects, compact objects, etc. * **Place** were the event happened. So, we can have words flexing differently for over ground, underground, air, space, over water, underwater, over ice, frozen in ice, over lava, molten in lavas, air bubble in solid or liquid. * **Speed**. We have different flexions for speedy things, slowly moving things, things at rest and retrograde moving things. * **Pitch**. Birds frequently communicate by using different pitches. The aliens do the same and their words flexes with pitch, so a grave *"foo"* is totally differently than a mid-pitched *"foo"* which also is totally different from an acute *"foo"*. For nouns that represents fellings or simple substantives, we all do know that: * The word for "Water" flexes for being water-color (a bluesh-violet with a tint of X-rays, since water absorbs IR and UV light and absorbs part of the red, orange and yellow hues) spheric transparent slowly-moving underwater. And it should be spoken in a high-pitched voice to not be confounded with a crab-like photosyntesizing creature that lives on rivers which is pronounced by the same word but using a low-pitch. * The word for "Happy" flexes for being a near-infraredly blueish, tree-like underwater childish speedy feeling. This should be spoken with a middle pitch. Pretty obvious, isn't it? * The word for "Love" flexes for being a yellowish x-ray striped hexagonal broken machine retrograde-moving feeling on the sky. Should be spoken in an acute voice in the first half of the word and with a grave voice in the second half. * The word for "Smart" flexes for being something associated with an opaque grayish near-UV spider-shaped worker stopped over the ground. It should be spoken in a grave voice in its first and third parts, but its middle has a middle-pitch. See? [I think that everyone agrees that this scheme of word flexion makes perfect sense for someone who normally speaks English!](https://en.wikipedia.org/wiki/Sarcasm) Finally let's give a look into **programming languages**. The aliens are very smart and could speak something that has the structure of object-oriented programming featuring things like aspects, closures, properties, listeners and design patterns. However, unfortunately for us humans, it also features weird, but wonderful, things based on colors (not restricted to what humans considers visible), textures, shapes and pitches. It is truly a very interesting and rich language. And their language scheme and richness is an essential part of what made them superintelligent beings capable of spacetravel. However, even if you manage to learn their language and understand what the aliens speak, you will never be able to speak it directly with your own lips, even if you learn to quickly and precisely change your voice pitch. The reason is that their talking apparatus and their hearing system is completely different than what happens with us humans. So, their phonemes sounds very different from the humans one. Humans have phonemes that are either vowels or consonants. Aliens, on the other hand, uses phonemes that could be categorized as **groars, barks or flutes**. In the end their their phrases, texts and speaks would resemble the structure of a very advanced, but also very esoteric programming language, in which the words (or tokens) sound for our ears as a random, but still patterned, very strange music composed of a very complex mix of clicks, slams, growls, roars, screechs, quacks, barks, sounds of drunken elephants trying to imitate cows, broken bells ringing underwater and drug-addicted birds singing while having diarrhea. [Answer] Some minor suggestions: * For a written language, [eliminate blank spaces](https://en.wikipedia.org/wiki/Scriptio_continua) between words. * Alternatively, come up with weird rules when words are compounded without blanks and when they retain blanks. * The different persons in a [conjugation](https://en.wikipedia.org/wiki/Grammatical_conjugation#Examples) could look/sound quite different. "I am" vs. "you are" vs. "he is" taken to extremes. That makes it difficult for readers, of course. [Answer] I will second here the idea of studying other languages and get inspiration from their structures. You need not even go too far: in German, for example, the verb generally comes last in relative clauses. It also happens that when a verb is composed of two words (like in "I was skiing") the second word is pushed back to the end of the clause. Such a structure is quite different from English. However, for an even greater difference, I would recommend looking into artificial languages. Not languages like Esperanto, languages like [Loglan](https://en.wikipedia.org/wiki/Loglan). > > The language’s grammar is based on predicate logic, which is why it was named Loglan, an abbreviation for "logical language". > > > Specifically: > > Loglan has no distinction between nouns and verbs. The predicate words can serve as verbs, nouns, adjectives or adverbs depending on where they occur in a sentence. Each predicate has its argument structure with places for arguments, which may be variables. > > > Now, that is really different. [Answer] If you want a major change from English, look to changing the syntax of the sentences. An easy change might be to add adjectives after nouns instead of before. Deletion of all prepositional phrases should make the language sound more formal. Depending on the storyline, delete or merge all pronouns or mess with tenses. Try to show something has happened in the past without using past tense verbs. [Answer] Great answers, to which I'll add two concrete suggestions: 1. Get the book "Word Play: What Happens When People Talk" by Peter Farb. A fascinating look at languages. 2. One of the things I learned about from that book was trade languages (Pidgin, lingua franca). For example, in a trade language you might create a plural by repeating a noun. So "boy" becomes not "boys" but "boy boy". [Answer] I find that one could subtly modify the perception of a language by using the [E-Prime](https://en.wikipedia.org/wiki/E-Prime) rules. Readers would not notice anything amiss for a while, then the discourse would begin to appear weird. I have also always appreciated another variation that people usually call *Spockspeak*, even if I find it much more taxing. ]

[Question] [ ## BACKGROUND *A corruption has seized hold of the land, turning great swathes of it into a poisonous waste that humans may only enter at their peril. Perhaps all who enter the waste grow sick or go mad, perhaps terrible beasts lie in wait, all that can be known is that evil has taken root in the earth.* --- This is a trope that seems to have have spread throughout popular culture, (esp. fantasy fiction, movies, video games) as if it were some kind of unnatural, virulent force. This may be related to the dawn of the atomic age and environmentalism, but realistically humans have made art about the fear of pollution going back as far as I've cared to look. Personal favorites, and good examples for this question, include Dragon Age and Nausicaa of the Valley of the Wind. **But to the point**, in most of these scenarios the corruption is either nuclear fallout (whether of the realistic or gonzo-mutant type), out-of-control industrialism (black coal smog and chemical spills everywhere) or supernatural (the earth turns black/purple/red and spits toxic fumes -- cue goblins). I really enjoy scenarios like this, and I was wondering if there are less trod upon naturalistic scenarios that could create a world along similar lines. --- ## QUESTION * **What is the best naturalistic explanation for large portions of land becoming corrupted?** Corrupted in this case means something like: polluted, toxic, perceived as eerie or unholy, like a divine plague, dangerous to humans, a wasteland. --- ## CRITERIA * **Earth-like world.** * **Corruption.** It should be dangerous, and noticeably change the landscape. Just being hard to traverse isn't enough. There's something about corrupted land that's "unholy" or "toxic". It should, in short, freak people out. * **Limited scope.** The entire world can't be corrupted. Some parts remain normal and habitable. * **Not too limited.** There should be enough corruption to create at least one Mordor-ish region. * **Long lasting.** Ideally it should persist for at least several human lifetimes. * **Natural event.** Bombs, aliens, bioweapons, etc. are all off limits. Earthquakes, volcanoes, meteors, even animal behavior, etc. are all good. Radiation is the most common source for a corrupted land, and remains 100% valid for this question. However, the natural event requirement stands. --- **Bonus points if ...** * The corruption has the potential to spread. * The corruption is dramatic or visually interesting. * The corruption alters local wildlife. [Answer] The volcanic gasses that fill the valleys near the Kikhpinych volcanos kill anything that stays in it for too long and poisons everything else that venture into it. Larger creatures like humans are known experience hallucinations, chills, and dizziness in the valley, and will die if they stay in it. Even the flesh of plants and animals that die in the valley become toxic killing anything that eats it and spreading the toxins further, dead predators and scavengers are found outside the valley all the time. There is actually a government program to clean up cadavers of dead animals to slow the spread of the toxins to the surrounding environment. It is not just one toxic gas like many volcanoes but a whole cornucopia of nasty crap that comes out of the volcano and builds up in the surrounding area. The area is appropriately named, the [valley of death](https://en.wikipedia.org/wiki/Kikhpinych). The natural shape of the valley causes the gasses to accumulate (since many are heavier than air). So any naturally isolated basin near such a volcano would be a good candidate, and what is Mordor, a mountain rimmed basin surrounding a large volcano, and it got worse when new management came in and built a giant wall and tall gate closing off the one exit from the valley. [](https://i.stack.imgur.com/ApwzI.jpg) <https://kamchatkaland.com/note/death-valley> <http://repo.kscnet.ru/3697/1/Karpov-et-al_VS_1983-4eng.pdf> [Answer] An invasive species would meet all of your requirements, but for a true corruption I would go for an invasive zombie fungus. Meet [Ophiocordyceps unilateralis](https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis) a tropical fungus whose spores infect ants, grows in their brains altering their behavior, making them climb high up into the trees and attach themselves onto a major vein of a leaf and wait while the fungus grows a large mushroom fruiting body out of their dying bodies and releases new spores into the wind to infect other ants. [](https://i.stack.imgur.com/ak2Np.jpg) This real world fungus is highly adapted to influence ants, but your world could have a similar fungus that is much less picky, and can infect a wide variety of animal species. These areas of blight would be truly horrible, sickly animals prowl around, everywhere their remains sprout into more of the dreaded mushrooms, latching onto and feeding off of the nearby plants and spreading their infection to other animals. Infected humans are slowly seized by madness and hallucinations, turning on those around them until finally their own corpse feeds the growth of more fungus. Mushrooms are known to cause mind altering effects in humans, so this is not that far fetched. Also many mushroom species are quite area specific requiring very exact environmental requirements to grow, making cultivation nearly impossible, so it could spread, but isn't likely to devour the whole world. I would imagine people would be trained to recognize the signs of infection and what the mushroom growths look like and would be ready to burn it with fire. [Answer] A Mazuku is probably your best bet. A Mazuku is essentially a "blanket" of carbon dioxide that is released by any number of natural events, such as volcanic activity, landslides, tsunamis, or from natural areas like lakes. Since carbon dioxide is heavier than air, in large amounts, it will hug the ground like a low fog, and collect into low areas. So if your large area is surrounded by mountains and the CO2 can't disperse, this will create your corruption event. Since CO2 is undetectable by eye, and odorless, any unsuspecting human walking in will likely quickly suffocate and die. In large enough amounts, even vegetation will be affected, so you can simply change the amount of CO2 in the area in order to decide how much of a wasteland it becomes. In terms of range, we have recorded at least a 25 kilometer radius from a single source (Lake Nyos event) - in your world, you could have an area that is filled with possible sources of carbon dioxide, where some trigger happens (an earthquake, perhaps), resulting in all those sources releasing all their carbon dioxide at once, creating an instant death zone. [Answer] **Mud volcano.** [](https://i.stack.imgur.com/cIE1I.jpg) <https://pubs.usgs.gov/of/2008/1019/pdf/OF08-1019_508.pdf> [](https://i.stack.imgur.com/7StQg.jpg) <https://www.youtube.com/watch?v=xSv6pO6gLpY> <https://news.nationalgeographic.com/2017/10/mud-volcano-lusi-indonesia-video-spd/> > > More than ten years ago, rivers of mud started spewing out of the > ground in five different locations on the Indonesian island of Java. > And it hasn’t stopped since.The disaster, termed the Lusi mud > eruption, is still spewing out mud and spans a little over six square > miles. At its peak, the region was churning out over six million cubic > feet of mud every day. A study published in Marine and Petroleum > Geology earlier this summer reviewed the extent of the damage. The > scientists found that some villages have been buried in as much as 130 > feet of relentless mud. Some 60,000 people have had to abandon their > homes, and 13 people have been killed. > > > Unlike the lahar, which is volcanic mud that comes surging down in a wave and kills everything in its path, the mud volcano produces a creeping death that covers the land, leaving it bleak and lifeless. The volcanic mud is hot when it comes out, but after it is out and covers the landscape it is difficult for plants to recolonize it, even in the tropics. This mud comes from deep in the earth and has almost no carbon or nitrogen to support plants; it is mineral clay. Also, like clay, it dries hard and roots cannot penetrate it. <https://nature.berkeley.edu/classes/es196/projects/2008final/Ross_2008.pdf> > > Considering how hard the desiccated regions of the mudflow are, the > mud could be an used as an effective housing material. > > > I like the idea of mud brick structures dotting the featureless plain of mud. You could riff on the mud theme. Volcanic muds also are full of sulfur and stunk of hydrogen sulfide. Bad for surface life but good for archons, and these can serve as the base of a food chain that supports huge numbers of flies. [](https://i.stack.imgur.com/5UokI.jpg) <http://www.desertdispatches.com/blog/2014/6/second-chance-the-owens-lake-project> flies And since this is fantasy, you could have other deep earth creatures come out with the mud. These take up residence in the thick mud beds, moving about as they did in their deep home, feeding on the rich surface life that has been covered. The mudscape is a poisonous waste, but it is not immediately lethal to visitors. It can be traversed. There are areas of high ground that have not been covered by the flows. The mud bakes hard and you can walk across - although the crust might not be as thick as it seems, and it is a long way down underneath. [Answer] Invasive species of noxious plant. You could have some plant (or fungus) that invades the area. Said plant would be resistant to removal. It could also release all kinds of "noxious" substances as defense mechanism to animals eating it etc. Depending on your theme, this could be magic, natural, or some genetic accident brewed up in a lab. To limit the area, you could have it vulnerable to extended periods of cold so it only affects temperate regions, or other biological reasons. If it was native in some area, maybe some animals there have adapted to eat it, but bringing them here may cause more issues then it solves. We deal with this all the time where I am from, well not noxious plants, but invasive species. It could even be a truly alien plant, brought here by accident or on purpose. Scientists often do things we later regret. I can name a dozen invasive spiecies that are causing biological havoc right now. Including these dang stink bugs and Japanese beetles. [Answer] You could go with high naturally-occurring levels of mercury -- possibly [cinnabar (mercury (II) sulfide)](https://en.wikipedia.org/wiki/Cinnabar)? A high enough concentration of this would be lethal to outsiders, but local flora and fauna have evolved various adaptations to it, in weird and twisted ways. Perhaps some plants have developed mercury storage pods that elemental mercury is diverted to as it metabolizes the compounds from the soil, and these pods periodically burst -- perhaps in windy or rainy conditions, to disperse the mercury away from the plant -- in beautiful but very toxic displays. Maybe some other plants metabolize the mercury into [methylmercury](https://en.wikipedia.org/wiki/Methylmercury) and circulate it through their leaves and stems as a toxin to thwart predation. Methylmercury poisoning symptoms include numbness in the extremities, loss of balance, blindness, muscle weakness, insanity, coma, and death. The flora and fauna of course look alien to the rest of the world as a result of their warped evolution. Anyone who lingers in the area too long will end up inhaling large amounts of atomized or gaseous mercury from the pods, and of course anyone who eats a mercury-circulating plant (or insect/animal) will quickly be poisoned as well. Some may enter for a mere day or two, and come back with lesser to moderate symptoms (weakness, blindness, etc); those who stay in the area a few days will often return insane, and/or fall comatose shortly after returning. The brave (and/or stupid) few who try to stay in or travel through the area for more than a week or so are never seen again, having rapidly accumulated mercury in their systems, falling comatose or dying while in this toxic environment. [Answer] Radioactive moon in a nearly geosynchronous orbit. It slowly kills or alters all life exposed to it, but it doesn't hang perfectly still in the night sky. It travels very slowly, circling the planet once every 500+ years, enough time for the far side of the planet to recover from its ill effects. People are forced into migrating every 500+ years to avoid the bad moon. Sometimes, the moon is over the oceans, only affecting small patches of land, these are the times of peace and plenty - then slowly it moves over one of the major continents, disrupting centuries of peace and prosperity before moving off again over the sea. [Answer] # Mold ## Effects In particular, a subterranean mold which feeds on the roots of trees and smaller plants, and spreads beneath the floor of large forests. After infesting a tree's root system, the mold injects a harmful chemical as a byproduct of its life cycle (adjust for sci-fi, fantasy, realism, etc.). This causes small, but noticeable effects on the host plant, and eventually will turn a huge area into a very clearly inhospitable wasteland. Thanks to bio-accumulation, this mold is able to produce progressively more extreme and deadly effects in creatures as you move up the food chain. Naturally as a result, nothing that has managed to survive in the infected forest would be edible. ## Spread ### Within an area Once a dense forest is infected, the mold is nearly impossible to stop. If caught during the absolute earliest phase of infection, it would be possible to completely extract the tree and root system. The mold spreads invisibly underground, transferring across roots which make contact between viable host plants. Left unchecked, the mold would spread a fixed amount per year, depending on density (i.e. More dense forests would spread more quickly). ### Beyond Periodically, the mold will inject spores into the host plant, which would spread throughout it. The spores would again travel up the food chain, until the creature they were in died and began to decompose, at which point the spores would attempt to latch onto any roots in the shallow ground beneath the corpse. ## Combating the mold Once the mold has taken hold in an area, the only way to make that space truly safe is to burn the Earth to a depth of 1m. The mold and spores die at a temperature of 200 degrees Celsius. [This could lead to some interesting cultural/religious practices depending on the setting, such as ritually burning the corpses of all wild animals one might come across.] [Answer] A Natural Fission Reactor would do, though one much larger than [the one found here on Earth](https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor). Oversimplifying, it's a horizontal layer of soil made of uranium, which achieves criticality. Water is involved, which can be handy for washing fallout out into the environment. "The natural nuclear reactor formed when a uranium-rich mineral deposit became inundated with groundwater that acted as a neutron moderator, and a nuclear chain reaction took place. The heat generated from the nuclear fission caused the groundwater to boil away, which slowed or stopped the reaction. After cooling of the mineral deposit, the water returned and the reaction restarted, completing a full cycle every 3 hours. The fission reaction cycles continued for hundreds of thousands of years and ended when the ever-decreasing fissile materials no longer could sustain a chain reaction." Besides messing with the size and power, you might want to change the cycle times from hours to years, decades or even centuries. This can feed legends of how the corruption was vanquished by a human action, event or ritual, and is now coming back due to another human action, event or ritual. All coincidences in actuality. [Answer] Here's an alternative to the [radioactive moon idea](https://worldbuilding.stackexchange.com/a/103644/49). Have the planet itself be the moon, orbiting a gas giant. The moon is not yet fully tidally locked so rotates slowly relative to the primary. The moon has a [Magnetic Flux Tube](https://en.wikipedia.org/wiki/Flux_tube) with the parent gas giant and the compression of the crust also causes intense volcanic activity when the gas giant is overhead. (This would also happen on the opposite side of the planet due to tides but maybe the magnetic flux can explain why it is worse on the near side). You would need to play with the figures but you could easily make some messy stuff happen, the main trick would be making the effected area small enough that the whole surface isn't badly affected. [Answer] I am going to do some 'what -if' musings here based on real events and real science. Coal seams close to the surface have been known to catch on fire through lightning strikes, and they can burn for decades, the longest has been burning for [six thousand years](https://gizmodo.com/the-worlds-oldest-underground-fire-has-been-burning-fo-1539049759), both above and below ground. When they burn to the surface, they can ignite brush and trees, causing localized flareups that appear to come out of no where. From the above article: > > Even more remarkably, ancient subterranean fires shaped the very > landscape of the West. "Much of the landscape of the American West—its > mesas and escarpments—is the result of vast, ancient coal fires," > writes Kevin Krajick in Smithsonian Magazine. "Those conflagrations > formed 'clinker'—a hard mass of fused stony matter. Surfaces formed in > this way resist erosion far better than adjacent unfired ones, leaving > clinker outcrops." > > > Along with pictures of 'alien'looking landscapes. Another description of a coal fire > > Fom the back kitchen window of his little house on a ridge in > east-central Pennsylvania, John Lokitis looks out on a most unusual > prospect. Just uphill, at the edge of St.IgnatiusCemetery, the earth > is ablaze. Vegetation has been obliterated along a quarter-mile strip; > sulfurous steam billows out of hundreds of fissures and holes in the > mud. There are pits extending perhaps 20 feet down: in their depths, > discarded plastic bottles and tires have melted. Dead trees, their > trunks bleached white, lie in tangled heaps, stumps venting smoke > through hollow centers. Sometimes fumes seep across the cemetery fence > to the grave of Lokitis’ grandfather, George Lokitis. > > > This hellish landscape constitutes about all that remains of the > once-thriving town of Centralia, Pennsylvania. Forty-three years ago, > a vast honeycomb of coal mines at the edge of the town caught fire. An > underground inferno has been spreading ever since, burning at depths > of up to 300 feet, baking surface layers, venting poisonous gases and > opening holes large enough to swallow people or cars. The > conflagration may burn for another 250 years, along an eight-mile > stretch encompassing 3,700 acres, before it runs out of the coal that > fuels it. > > > [Read more:](https://www.smithsonianmag.com/science-nature/fire-in-the-hole-77895126/#UPjv6OBXKxllTXfr.99) Weather inversions can trap smog and pollution underneath a layer of air, that can drive air quality into dismal areas. Carbon monoxide is poisonous to humans, is odorless, is heavier than air, and kills silently. Sulfur dioxide would also be produced in great quantities - a gas as foul smelling as you can get. Limestone ground formations can easily be carved into underground karsts over large areas by underground streams. Coal, limestone, sandstone, and shale are oftne found in layered deposits. A deep river valley with steep sides can produce an air trap, in that dominant winds just blow over the top. So, let's combine then. A confluence of these separate conditions. A deep valley, that has a permanent inversion over it. Air is trapped underneath, and there are no winds to blow it away. An extremely large coal seam ignites, producing tremendous amounts of carbon monoxide. This carbon monoxide stays heavy in the air, but there are oxidizers available to keep the coal seams smoldering. A cave system carved out from limestone and water, over a wide area, could be a source of oxygen feeding the fire. So we have an area with very heavy air, smoke particles, the smell of sulfur, and deadly but invisible, odorless carbon monoxide gas. Humans and animals would appear to just collapse, and rescuers would suffer the same fate. Trees and shrubs burst into unexplained flame. Vegetation above the burning seams would die off. These areas would move around as the seams burned, and the karsts provided oxygen. It would be an area of mysterious, random but quick death, unpredictable and unpreventable. Animals quickly expiring, and would avoid the region. And the ground would be black, hard, lifeless clinker. One of the signs of initial carbon monoxide poisoning is confusion, unco-ordination, and dizziness, with effects like paralysis. I believe this fits all of your criteria. [Answer] Radiation is the most obvious option; but you would need an isotope mix, and an intensity, that's next to impossible to come by naturally (or as side-effect of 'conventional' nuclear explosions or known industrial nuclear processes); moreover, it would decay pretty quickly. You would need an incredibly high contamination by middling half-life isotopes - not so active that they burn in a few months, yet active enough that tons of them aren't required to achieve effect. I don't see this occurring "naturally". Another possibility is a [**hacker organism**](https://en.wikipedia.org/wiki/Sacculina_carcini) or *vermigon*. It needs only to mutate once to be able to change its habitat and invade, and the consequences can be as spectacular and/or horrible as desired (from a crab's standpoint, a Sacculina infestation is a zombie apocalypse). Even so, the roaming form of the parasite - the *kentrogon* - is usually adapted to a specific host, and it's unlikely to be able to parasite a wide range of other organisms. If it was, though, its creep factor would shoot out of the roof. The organism might have mutated, or might have thrived once and then been left semi-dormant for ages in the arctic permafrost, until climate changes both thaw the permafrost and allow animals to begin grazing the area. Perhaps both of them - imagine a mammal-infesting *Sacculina* analogue, lying in wait on the ironically named island of [Vozrozhdeniya](https://en.wikipedia.org/wiki/Vozrozhdeniya_Island), after being mutated by the wealth of toxic wastes that were dumped in the area. [Answer] An ecological disaster, brought upon by over-hunting. Imagine a plant with the [swift growth rate of kudzu](https://en.wikipedia.org/wiki/Kudzu_in_the_United_States#Ecological_relationships), and the [terrifyingly excessive toxicity of the Manchineel tree](https://en.wikipedia.org/wiki/Manchineel). A certain animal (perhaps a type of antelope) has the ability to eat this toxic vine, and keeps the plant's population density low. However, once humans discover the area, they begin hunting this antelope until- surprise! -the hard-working ungulates are all extinct. The vine then begins to grow out of control, overtaking first ditches, fallow fields, and abandoned properties. If the humans do not have sufficient technological sophistication to safely remove the plant, within a couple years their settlements and most of the land will have been overtaken by a green and deadly blanket. [Answer] A fungus could do it. The largest living thing on earth is a parasitic fungus in Oregon. It stunts the trees. <http://www.extremescience.com/biggest-living-thing.htm> Imagine if that fungus also secreted a neurotoxin... [Answer] I don't think I've seen this mentioned yet: A Virus. IE: the [T Virus](https://www.urbandictionary.com/define.php?term=t-virus) My idea is a variation on all the Zombie Virus'... with the idea that the virus (or disease) doesn't affect humans directly. Whether man made ([CRISPR Gene Editing](https://en.wikipedia.org/wiki/CRISPR) gone wrong), alien introduced (You don't think they successfully found everything after Roswell do you?) or a [naturally occurring pandemic](https://doh.dc.gov/page/naturally-occurring-pandemics)... **What does the virus do? need? affect?** Options abound! * It's not airborne... and started in Hawaii, Japan or some island. * It requires dryness - water kills it. Limiting it to desert. * It requires water - dehydration kills it. Limiting it to swampy areas like Florida or the once pristine Everglades. * It requires: Hot/cold/fresh water/sea water/grasslands/mountainous areas/etc... * It interacts with other ideas mentioned by others - volcanic gasses, mud-nado's, CO2 hot spots, fungi, etc * It only affects insects - makes them aggressive, multiply faster, bigger * It only affects plants - they now hunger for... blood. The fight to find the vaccine/cure for the virus is intense! Will they find the cure before it mutates? Stay tune and find out next week... [Answer] Although I think other answers are better, I’ll throw this in for “completeness.” Somewhere in the Rockies, there is supposedly an outcropping of uranium ore rich enough to be dangerous. There is even a story, no doubt a **gross** exaggeration, of someone seeing an animal jump onto this rock and immediately die. Half-life of U-238 is 4.5 billion years. It’s plausible, though unlikely, that a young planet could have enough of it in one area for sapient creatures to figure out that there’s “something” strange about that place. Perhaps they are good at something akin to our scientific method (so they’ve noticed a correlation), but they don’t yet have the technology to identify radiation. [Answer] In [this question](https://worldbuilding.stackexchange.com/questions/101491/anatomically-correct-typhon) I was told an explanation of how a being similar to Typhaon might exist. The details of *that* creature are irrelevant but the explanation can be adapted here. In fact, it could be its relative. Your corruption is a living cloud of bacteria. As it consumes and spreads it sometimes goes dormant until something living walks by. Then it descends upon the victim and devours it whole (or worse keeps it alive for days using it for food). So how could this develop? Well you need a few things. First you need functionally immortal cells so they don't just mysteriously die all of a sudden. There needs to be an initial quantity of them so massive that someone doesn't merely get sick. They are actually devoured. This could likely start in a tropical or densely forested region. It could've been a way to combat a mold outbreak in some protected forest that got out of control. Such a disease could grow to have a central hive mind. Perhaps part of what made them stronger was to give them a modification that made them electrically conductive and able to store static electricity to use to kill or tear apart other cells. Essentially a bacterial version of a nerve cell but still capable of being a bacteria. Such a bacterial hive mind could simply alter the ground as it becomes part of its massive multi-cellular colony stretching deep into the ground. > > Perhaps all who enter the waste grow sick or go mad, perhaps terrible beasts lie in wait. > > > The first could be the bacteria messing with people to toy with them or trap them. The latter could be the results of the bacteria finding a more suitable way of moving about then mist. Essentially they could grow into a body perhaps or re-purpose lifeforms into beasts that serve the hive mind. Giant swathes of poison could be the waste from the giant creature. It would look like normal poison since... most natural poisons come from either bacteria waste, plant secretions, or venom. It being the first isn't anything special. I'm prepared to try and diagram such a cell if anyone wishes, but I am not a biologist so don't be upset if it isn't exactly like a normal cell looks. [Answer] You could consider a toxic ecosystem feeding on pollution leaving only some area untouched, protected by, say, wind as in ghibli's [*Nausicaä of the Valley of the Wind*](https://fr.wikipedia.org/wiki/Nausica%C3%A4_de_la_vall%C3%A9e_du_vent_(film_d%27animation)). In resume: > > Human pollution has transfigured nature into a highly toxic > environment where everything rot but news species of insects. No human > action can reduce the affected area as every violent attempt results > in an equally violent reaction spreading the toxic environment even > further. > > > To me, this idea was strongly suggested by your background but it also answers all of your criteria. For example: * Earth-like world. It's a naturalistic explanation that could totally happen on earth (with heavy human pollution). * Corruption. The corruption is highly dangerous. Even one breath in the deepest forest is enough to condemn your life. And that is without accounting for the territorial giant insects. * Limited scope. There remains places where human can live, some desert, and even some high quality valley. * Not too limited. In the movie, the whole earth is polluted and suitable for corruption spreading. The fact that places remain untouched is only due to environmental luck of human constant vigilance. * Long lasting. The corruption has been there for nearly as long as human can remember. Time before corruption is only told through ancient legends. * Natural event. Well, you can't be more natural than nature itself. Annnnnd the bonus points: * The corruption has the potential to spread. Totally. * The corruption is dramatic or visually interesting. Beautiful shroom-like scenaries in the movie but can be adapted at will. * The corruption alters local wildlife. You get a whole new set of giant insects on steroids (or anything more at your conveniance). [Answer] Great ideas so far! Since you also mentioned "evil", here's a less physical, more spiritual one: The land is not sentient, but has some kind of inherent spiritual awareness. So, activities performed on the land effect the "spiritual atmosphere" of that area of land. Particular acts may be tied to certain spiritual beings. These beings may influence humans toward certain actions, for their own agendas, including the furtherance of desecration, or other more direct motives. A being may "hang out" at a certain spot, causing more of the particular act, and increasing his power. For example, a spirit of death, or spirit of violence will attempt to influence people toward violent acts. Any violent acts perpetrated, causes the land to react negatively. The land is trying to distance itself emotionally from the act, so it "shuts down". The opposite process is also possible to create "blessed land" by sustained righteous acts on the land. Cursed land may also be "redeemed" by purposefully opposing the negative effects and causes. [Answer] Stage one biological life would fit the bill. life in a new location (after life kicked the bucket there for whatever reason) begins with small bacteria that do some form of terraforming: they turn conditions that are bad for most life into better conditions (turning the environment hostile to them in the process). A very good "corruption" scenario could be the opposite : a bacteria that turns otherwise hospitable environment "bad". Ravenously unbinding nitrogens to kill plants, producing cyanide and acids to make it hostile to humans, making methane and sulfur for a bad smell. Bacteria have no problem with these things. If they can't spread airborne it would also make for a nice "front" that spreads. As for wildlife alterations: also possible. Viruses can alter psychology to make wildlife aggressive (think rabies) and bacteria can easily cause lesions and boils and other visual indicators of "corruption". And the best/worst part: stage one are called that for a reason. They are the "colonists". Since the changes they make usually turn the environment against them, they make way for more advanced lifeforms. This would cause a nice, progressive corruption with continuously mounting pressure on any nearby life that happens to benefit from the situations that the stage one lifeforms "fix". This definitely has the potential to envelop a continent. Almost all land life followed the three stages of colonization at one point or another. It would require a starting point which was isolated, because life doesn't pause until convenient (ask American teen moms). Easiest would be a natural barrier like the sea or a ravine. Reasons we don't have this problem : chance. It would have been entirely possible that some life evolved to require different conditions to sustain itself along with different stage one life, which is "assertive" enough to evict previous occupants. Perhaps it DID happen during early life and we are the corruption. Who knows. [Answer] ## A simple big herd of cow like creatures But simply add few features to them: 1. They are in a very large number 2. They are omnivorous at a large scale (eats simply anything that is not of the same species) 3. When they don't find something else to eat become easily cannibals (eats their own species) 4. Add that their dropping is done with a gas that is unsustainable for most of other livings 5. After they have "destroyed" an area, their faeces are in the first place full of microorganism that are a vector for some really bad deseases After some decades, the soil can become back to normal, even experiencing an incredible plant growth, so the corruption is still only located in the path of the Herd. The bonus point would be that the herd is roaming naturally arround some kind of big mountains chains on a single continent for centuries, making the land around it experience the corruption as longer seasons. The possibility for it to spread would be people from another continent wanting to use them as cattle because they can easily feed on a forest or even funnier, their enemies. [Answer] *A strange bacteria has been dumped into a forest nearby the peaceful village of Talahul, The trees have become grey and drooping, their branches snagging the unwary, and the bacteria infecting all with a violence and speed unlike anthing else seen on the planet.* ## Spread It can only spread with help from other animals, it transfers itself like pollen, except anything can infected, plant or animal. [Answer] An organism begins to metabolise an important element is a evolutionary positive, for the organism, way which is detrimental to the current life forms. Happened when photosynthesis kicked of and the increase is free oxygen cause problems for the *legacy* life forms. See Peter Watts "Behemoth: B-Max" - third in a series but this is when it all happens. A bacteria (from memory) starts locking out sulfur from the ecosystem causing massive damage to the *legacy* lifeforms, i.e. everything alive now. Spread by contact, so at the beginning it is localised but is spread as creatures try and escape its effects. [Answer] I'd suggest having the magnetic poles stronger and not aligned with the cold zones of the planet. (Neptune and Uranus have magnetic axes strongly tilted to the "\_vertical" axis, so its not unreasonable). Also very strong fields and some kind of suitable small companion object to the sun..... This has some interesting side effects for your scenario..... The magnetic poles would be located in prime habitable areas of the planet. In the area around the pole, compasses wouldn't work any more, and the effect of magnetosphere protection from cosmic particles wouldn't be present - charged particles would be attracted to those areas, and if the star system was comparatively active then a person entering these areas would find no compasses working, weird coloured sky and electrical/atmospheric effects, dangerous mysterious wasting fevers/sicknesses unlike any other after a while due to higher radiation levels (dangerously high in some cases - say the sun had a small companion star or object that gave out a large level of particles or xrays), attraction to some particles and lack of attraction for particles that might have provided proctection elsewhere, spooky absence of life (much life will leave and the flaura/fauna will be markedly different). It would need fleshing out but in principle maybe this could provide a zone of the kind described. [Answer] While I am very late to the party (don't know how I missed it earlier), I'd go one step further than "noxious plants". Noxious ecosystem. Which is spreading since it outcompetes the ones we depend on. This has the great advantage that is has already happened, so we know it's possible. I'm talking, of course, about [the Great Oxygenation Event](https://en.wikipedia.org/wiki/Great_Oxidation_Event) several billion years ago. Once photosynthesis developed, the new species outcompeted their rivals. In the process, they gave off free oxygen, which was toxic to the existing ecosystem. Eventually, the new oxygen-emitters took over the world and destroyed the existing order. [Answer] I'd like to throw an idea into the ring: something similar to the [Messinian salinity crisis](https://en.wikipedia.org/wiki/Messinian_salinity_crisis). During the crisis, it's believed that, after the Strait of Gibraltar was blocked, a large fraction of the Mediterranean Sea evaporated. What remained was a large basin that might have resembled a salt flat like the [Salar de Uyuni](https://en.wikipedia.org/wiki/Salar_de_Uyuni). Any plants or animals that lived in this basin would have had to adapt to extremely saline conditions. On top of that, since the floor of the basin lay multiple kilometers below sea level, the descending air currents compressed, resulting in increased atmospheric pressure, and temperatures well above the hottest temperatures seen on Earth today. Any creature from the normal world would struggle to survive in a basin like this, and they would encounter huge, desolate salt flats, horrific temperatures, hyper-saline water, and they'd have to contend with whatever desperate plants and animals managed to survive in such an environment. In regards to your question of a *spreading* nightmare: perhaps only part of the basin in question has evaporated, while there's a region that remains almost normal, waiting for its sea to evaporate. [Answer] I am surprised to see that none of the answers above took into account overpopulation. This is a natural phenomenon that leads to corruption in any setting in which biological organisms live in very close quarters. Human society is but one example. Most of the viral pandemics are a mere manifestation of the corruption inherent to overpopulation. They usually happen in large cities or large army encampments that concentrate animals and crops as well. Take the example of large tracts of Indian soil being infected with pathogens derived from human feaces. Overpopulation brings also psychological forms of corruption, moral blight that eventually leaves a measurable mark on the land as well. Take as an example the forests of Romania being razed for decades due to a hierarchical system of corruption that has ultimate origins into people voting for corrupt politicians. They vote like this because corrupt leaders reflect their voters own moral corruption acquired while trying to survive a world of diminished returns, ultimately caused by overpopulation (the decree by Ceausescu to forbid contraceptives in the 80s). **Edit** If an agglomeration of ants destroys a planet it is still a natural explanation (entirely possible, the first mass extinction in our planet age was arguably caused by sea sponges changing the acidity of the oceans). If the ants were sentient in a way us humans would comprehend, of course we would call it artificial, however organism agglomeration is not an artificial happening. It is called "artificial" only if you design it. Nobody designed humans to congregate in cities, they just sort of did so. So I would argue that even human overpopulation is a natural phenomenon. ]

[Question] [ Inspired by [this question](https://worldbuilding.stackexchange.com/questions/95043/why-would-a-staff-increase-the-magic-power-of-a-wizard), [this question](https://worldbuilding.stackexchange.com/questions/91717/how-would-it-make-sense-that-spellbooks-or-grimoires-teach-only-one-spell) and [this question](https://worldbuilding.stackexchange.com/questions/91767/how-would-it-make-sense-that-spellbooks-or-grimoires-teach-only-one-wizard), I, too have been thinking about typical RPG-style magic systems. It's a truism in RPGs (and fantasy in general) that [armour and magic don't mix](http://tvtropes.org/pmwiki/pmwiki.php/Main/armourAndMagicDontMix) (fair warning: that's a TVTropes link) - that is, wizards are capable of astonishing feats of magic *as long as they wear nothing more protective than robes and a pointy hat*. This is, of course, done for reasons of balance, and often handwaved away by saying that the armour is restrictive and prevents the wizards from performing the [complex gestures](http://tvtropes.org/pmwiki/pmwiki.php/Main/MagicalGesture) (also a TVTropes link) necessary to cast spells. Speaking as someone who owns a [haubergeon](https://en.wikipedia.org/wiki/Hauberk), this blanket ban on armour (for this reason) seems at best suspect, especially given the existence of cleric-type characters. I for one would rather wear mail than robes with massive sleeves if my life depended on waving my hands about in complicated ways. Let's assume a typical [Forgotten Realms](http://forgottenrealms.wikia.com/wiki/Main_Page) style universe, with similar magic rules to [Secespitus' question](https://worldbuilding.stackexchange.com/questions/95043/why-would-a-staff-increase-the-magic-power-of-a-wizard?noredirect=1&lq=1), but closer to those used in the Forgotten Realms: * wizards draw upon magic that [permeates the universe](http://forgottenrealms.wikia.com/wiki/Weave) * They learn spells through study and on special occasions, such as reading a grimoire * wizards prepare spells by memorising them, and cannot cast spells without first preparing them - the memory of the spell is wiped from their mind when cast * They can do all of the normal things for this genre - throw around fireballs, create walls of earth, fly through the sky, etc. * Spells have power proportional to their caster's skill and knowledge about magic and how to use it efficiently. This can be represented by a stat like Intelligence. * The God(s) have nothing to do with this kind of magic (think of it as [arcane](http://forgottenrealms.wikia.com/wiki/Arcane_magic) rather than [divine](http://forgottenrealms.wikia.com/wiki/Divine_magic)) * Casting spells requires the wizard to say the magic words and perform the ritual gestures (see D&D's Verbal and Somatic components, let's ignore Material components for now) * Wearing armour massively reduces a wizard's ability to use magic Given the above, **why would a wizard not be able to use magic while wearing armour?** I'm looking for a sensible in-universe explanation as to why armour *in general* would prevent a wizard from using magic while worn. To be clear, some armour types *are* restrictive enough to (theoretically) cause problems - we see this IRL with things like tournament armours, but we have [pictures](http://www.medievalists.net/wp-content/uploads/2015/10/archers-e1445747739910.png) of archers shooting in plate harness, and properly sized mail imposes virtually no restriction on freedom of movement, so a blanket ban doesn't add up. This edit might invalidate the text of some of the extant replies, but hopefully it shouldn't invalidate the *concept* of any of them and narrows the scope of the question enough to be reopened. **If you're reading this and thinking of an answer based on metal interfering with the flow of mana, or armour being cumbersome and preventing the wizard from making the necessary gestures to cast their spell, *please* stop and consider whether you're adding anything that the *fourteen existing answers on these themes* haven't already added.** [Answer] Easy. Metal interferes with the correct and proper flow of mana. Depending on how far you would want to take things you can say wizards can't stand to be near any metal at all while spell casting, so no metal weapons either. Or you can just say that the wizard being surrounded by metal (as they would be while wearing metal armour) prevents them from properly controlling mana. So they can still use a sword if you wish. This could manifest itself in a number of ways, perhaps the armour gets magically charged and this causes discharges of power that are very dangerous. Or the wizard just loses control of their spells due to the interference of metal and either nothing happens or the spell goes badly wrong. Edit: I don't think the edit to the question changes this much, but the addition of the further classification of the type of magic does allow a further explanation. Metal disrupts the Weave, causing dead zones and preventing wizards from accessing it properly and casting spells correctly. [Answer] Wearing armor is a skill. Just strapping armor on someone who isn't physically fit, doesn't have the callouses, muscle strength, and proper reflexes means the armor is worse than useless. It will actively impede their movement, make them fatigued, and distract them from the fine concentration necessary to cast magic. While warriors are wearing armor, getting it properly fitted, and tuning their bodies for it, magicians are studying. If a mage were to spend time practicing in armor then they would miss out on spell study. Just having armor on, with no knowledge of how to move in it, use it to block hits, or the stamina to wear it for long while running around won't lead to the "armor class improvement" seen in game systems. Several RPG systems accommodate this "resource management" concept. DnD 5e, for example, has NO ARMOR RESTRICTION for magic use, provided they have proficiency in that armor. But will a mage character spend a precious skill on armor instead of a more directly useful magic feat? So "in universe" you can effectively prevent mages from wearing armor while casting without having to require it interfere with magic casting directly. Even boiled leather or quilted armor, while not that bad when wearing it in the comfort of your house, quickly becomes a big nuisance when you wear it all day tramping through the woods. Distractions are death for mages... To address some of the comments to my answer, I believe in a RPG system, armor class is more than just passive resistance. Sure, you could drape a chainmail shirt over someone and presumably it may protect from an arrow hit (kind of like how journalists or prisoners wear ballistic armor today) but *in a fight* being unfamiliar with wearing armor means you won't react appropriately. Movies love to show a belly slash with a sword against someone wearing mail as being a lethal attack, but in reality that would be worse than useless as it would just dull your sword edge. A warrior would know this and not defend against a belly slash and instead strike, but a mage may not and would instinctively react to protect their belly even though they didn't need to. So this is why wearing armor may not increase your armor class without training, so why bother? Armor has to be tailored to the individual for full mobility. Mail shirts are not one size fits all. They have specific expansion areas in the shoulders to allow for the arms to swing, they are tapered in areas so they don't have excessive weight. Rigid armor sets are even worse, they need to be tightened in specific ways and are usually worn over a bulky padded underlayer. You can't just pick a set off the shelf, strap it on, and go for a jog. So a mage unfamiliar with wearing not just armor, but a *specific* set of armor, is gonna find that a certain set of gestures won't work *while casting a spell in combat* to potentially disastrous results. The risk/reward ratio is in favor of no armor. Clearly things like bulky winter clothing shouldn't interfere with spell casting (unless you really want to penalize casters) so there is a bit of handwaving. Though presumably folks in cold climates have their winter clothes and have practiced in them, modifying jackets and such to allow for proper spell casting. Maybe this is why wizards are always shown wearing robes! The least restrictive clothes to allow for the precise gestures and movements required. But unless casting spells involves yoga positions or something similar it is a little bit of a logic tweak to say that padded or leather armor will interfere with casting but a heavy woolen jacket wouldn't. So I'd say that a caster in fitted leather armor could still cast spells, but wouldn't know how to fight in leather in order to receive an AC bonus. This could apply to fitted plate armor as well. You could spend a day and a bunch of money getting it custom fit, but without *years* of fighting practice a wizard in plate is barely more protected than one not in plate as the weight of plate would throw off their reactions, make them easy to knock over, and they wouldn't know which vulnerable areas to protect and what areas they can use to block an attack. Add in the *possibility* of messing up a spell due to the armor and it becomes obvious that casters, unless they are of a specific battle mage school, should forego armor if they have any intention of casting. [Answer] A wizard wearing armour is a disgrace – it suggests his magic is poor. Regardless of how good his magical defences actually are, relying on armour makes him look weak – and thus, regardless of anything else, no-one will hire him. Perhaps this even extends to undermining *his own* confidence, rendering his spells weak? [Answer] Here is a fun folklore based reason. The bane of all fairy magic is Cold Iron. It comes up a lot in folklore and some think it might be the source of a horse-shoe for luck. It might have been the only bit of decent cold iron that a peasant might be able to get their hands on. Anyway, this root of folklore plays into a lot of modern fantasy works with iron having all sorts of effects on magic from an inconvenience to the Fey up to warping the effects of all magics. it all kind of depends. So here is a structure that is logical: Magic is Energy! Somewhat but not entirely like electricity. Like electricity, magic will try to go to a ground or earth plane. That means the presence of large amounts of sheet metal, like plate armor, would act like a ground plane and disrupt subtle spells The more subtle and complex the magic is, the smaller amounts of metal you can be near without the effects becoming harder and harder to cope with. Think in terms of Radio Antenna design. For faint signals you need precise design and as my uncle the engineer (who built them) it became more of a black art than science. So your mage, when young, deals with big whomping spells and as he progresses has to be more and more aware of the metals around him. Armor would simply get in the way of the magic and become more hassle than it's worth. Besides, if you are tossing lightning about, a big metal shell is not the greatest idea. [Answer] Metallic armor acts like a Faraday cage for magic. (I.e. won't allow the power to get in.) A Faraday cage prevents outside electromagnetic energies from entering the cage. In this case, the magi would be inside the chain mail metal suit, which would make a perfect Faraday cage. There are you-tube videos of people wearing chain mail suits while Tesla coils send out jillion volt lightning bolts all around them, even striking the armor. So if the process of generating the power to create the magic came from some form of electromagnetic energy (drawing lightning from the sky, for instance) the chain mail would prevent it from reaching the magi in order to be harnessed. [Answer] Not all magic is incompatible with all armour. Nature magic and leather armour are fine as the druids and shaman will explain. Holy magic has no problem with full plate as any paladin will tell you. **The problems are frost, fire, and necromancy.** There are some obvious factors. Metal is heavy, mages tend to spend more time in the library than the gym and hence would have some considerable trouble moving around in 40lbs of armour. There are some secondary factors for frost and fire. Metal is a really good conductor of heat and often doesn't respond well to extremes of temperature. Some metals freeze and shatter, or contract excessively when cooled. Others will go soft at high temperatures and become useless as armour. The mage would certainly be more comfortable with better insulation rather than the extra weight of shattered half melted metal, and that's before even being hit by anything. **Necromancers are an entirely different game** from your average frost and fire mages. Necromancy just doesn't work if you don't look cool enough. It's all about those robes, gotta look good. [Answer] So no answer can be "in universe" or this question should be closed as that is purely the problem of the universes creator. **Aside from that,** **One mythological look at magic, particularly fairy lore poses the notion that processed iron can hurt/trap/dispel fairies.** There isn't ever an explanation for this however I always viewed it as: * magic comes from nature * metals are produced by processing 'perceivably' immortal natural objects into solid man made forms so its this corruption of an immutable natural form that gives iron (as well as any metals of your choosing)its anti-magic properties. **By this explanation** it justifies why mages wouldn't wear metal armor and why they tend to wear leather armor. If you were a mage you would want your fireballs to be as strong as possible. **Concurrently**, this also explains why metal armor is able to resist magical attacks as well as they do. Like how the heck does a knight survive a full blown lightning strike? [Answer] Casting spells is *incredibly physically taxing*. Every spell is, to borrow terminology from the fitness world, like trying to lift your one rep max weight *while doing partial differentiation and singing the alphabet backwards in Urdu* Wearing armour compounds this problem - it's a struggle to stay on your feet while casting in light clothing, and anything heavier than a tunic is just too much for most wizards (who, after all, don't tend to be the most physically fit people around). [Answer] ### It interferes with their daily routines Wizards have various [rituals that they must perform](https://worldbuilding.stackexchange.com/a/91721/28789) in order to fully master their spells. Wearing armor takes practice and time, it interferes with certain rituals, it's heavy when you have to carry it around and it shows that you are dangerous and prepared for a physical confrontation when all you want to do is look harmless until someone turns his back to you, which allows you to throw a ball of fire at him. Wizards just find wearing armor inconvenient. It doesn't offer anything their magic wouldn't offer and it's far too much of a hassle when thinking about what they have to do to stay as strong as they are on a mental level. Everything that needs some concentration needs to be eliminated - you don't want that Fireball to explode in your face, do you? By sticking to routines, rituals and rules your wizard stays mentally capable of casting spells throughout the day - wearing armor is something that interferes with this concentration, which is very dangerous when wielding power that is normally beyond humans. If your wizard is not careful and doesn't perform his daily rituals his magic might not work the way he wants it to work in a critical moment, leading to his death. And death is not a good thing for most wizards - at least if they are the ones who die. You need to provide an incentive to *not wearing armor* by making it affect the areas where your wizards are especially good. If you need different types of mages where some are capable of using armor and others are not you could vary the kind of rituals. A war mage might in fact need to spend at least 4 hours every day in full plate armor. It's what he always does, it's what feels natural. It helps him concentrate and brings him into a mental state where he is able to quickly react to any danger. When he takes off the armor he suddenly feels all the tiredness of the day and becomes far less capable of using his magic. But war mages are not wizards - that's why war mages need to wear armor, while wizards can't wear armor if each one wants to be capable of using his magic. [Answer] If you don't need to worry about it for reasons of balance (which I'm going to assume is the case since you're asking here and not the RPG.stack) why not put the cart before the horse. **Wizards eschew armor because it's frivolous** Any wizard worth their salt doesn't bother with armor because their magical protection is inherently superior to any armor. Instead they wear what is comfortable. A new apprentice who still hasn't mastered basic protection spells might need to wear armor while learning them or practicing combat magic. This has also led to a bit of a stigma on wearing armor; If a wizard is wearing armor most other wizards (or in the know folk) will assume she hasn't mastered protection spells yet, so a prideful mage may go unarmored even when they haven't quite mastered protection spells to avoid the embarrassment of others learning of their lack of skill. Finally most opponents won't even try to stab a wizard without some sort of magical blade, due to the potentially lethal nature of common magical defenses which leads to some perfectly capable, but slightly lazy wizards not bothering to cast their magical defenses every day (security through obscurity). [Answer] Armour is heavy. If you've ever worn a chainmail top, you'll know. Becoming a wizard requires massive study and devotion to books, resulting in wizards being physically weak because they can't devote time to training. Magical handwaving if needed – perhaps mental training for magic takes the nourishment from muscles. Thus wizards just don't have the strength to wear decent strong (and therefore heavy) armour. [Answer] # Magic as a Mystical Energy Magical Energy has problems transmitting through non-natural sources. Anything processed can provide problems, interfering with magic by either preventing it from happening, or altering the magic itself. What happens depends on the material, but a few possible guidelines help: ## Ferrous Metal Metal based armors absorb magical energy, as they conduct energy efficiently in any form. Due to this, metal armor causes the energy to course over it, losing focus and potency in the circuit of the armor and caster until it loses almost all power. The chance of being able to cast through this is low. Weight can also cause concentration issues. ## Animal Hides/Leather Hides and leather, however, are the remains of dead animals. This taints the magic, causing it to either carry traces of necromantic energies, or the energy of the creature itself. In some very specific cases, armor like this could be beneficial, but only if it is a rare creature of magical energy, and only if the caster only wants to cast one type of spell (that associated with the creature's energy). The armor still causes the spell to lose power, and thus have a chance of not working, but is also tainted by the energy of the creature the skin came from. ## Natural Fibers Natural Fibers that are not mixed fabrics allow the caster to have the least interference in their casting, thus allowing them to channel properly. Magical energy passes much more easily through cloth than through animal remains or metal, and that energy isn't altered. This allows easy casting that follows the intent of the caster. ## Bonus feature: Power Foci Focusing power through objects such as wands is deliberate. The wand is typically made out of conductors made of animal remains or metal because then the downsides of armor can be focused as positives, by conducting the power to a singular point of focus. They can still flavor the magical energies, but when deliberate and focus-able, it allows more control over the shift in energy. [Answer] **Spellcasting has side effects** No mage is perfect. No spell is perfectly controlled - which means that every time they throw a spell around, the mage is also releasing chaotic secondary effects out into the immediate space around them. Those effects are really rough on things like heavy armor, often reducing it to an unusable state after only a day or two of a standard adventurer's workload of spellcasting. Higher-powered mages can afford this better, but they also throw around more powerful spells, which means it tends to happen (much) faster. Thankfully, mages have figured out a few relatively straightforward enchantments for making robes self-repairing, but no such enchantments have been discovered for the heavier armors. Also, if a fight happens, you might want to give the wizard some room. Just saying. Basically, while they technically could wear armor, it's not worth it for the sheer cost of keeping the stuff repaired... and that means that it's not worthwhile for the mages to learn to wear the armor properly in the first place. Also, while the mage is protected from the direct effects of his spell's spillover, he isn't protected from the spillover. Independently wealthy mages *have* worm plate in the past. Independently wealthy mages have also died a time or two in the past when their armor got warped by spacial magic into a cage of inward-pointing spikes. [Answer] This answer is inspired by a line in [Dan W's answer](https://worldbuilding.stackexchange.com/a/99461/559). ## In short: It is all about confidence. Magic is supernatural. Yes, in this universe the *magical energy* is part of the world, but fireballs don't just spontaneously erupt from the sky. Using the energy allows you to break the normal physical rules of the universe, it allows you to change causality. Breaking the normal physical rules requires not just that you say the right words, and perform the correct gestures, but that you actually believe that the ritual will have the intended result, and that you personally can control causality. It requires suspension of disbelief. Any doubt weakens or completely undermines the casting. A skeptic performing the ritual with technical perfection but not believing it will do anything will produce no results. With this in mind, besides the potential for the armour physically getting in the way of the gestures, there is nothing about armour that is technically incompatible with magic. However wearing armour still weakens a practitioner for two reasons, both of them are psychological: 1. Armour is a tool to mitigate risk of harm. Wearing armour is an implicit acknowledgement of that risk, thus on a subconscious level undermines the belief that you are in control. If you were confident you were in control, then you are not at risk and wouldn't need protection. Wearing simple robes is acceptable because that isn't about protection or control, it is about modesty and keeping up cultural norms. 2. Culturally people are taught from a young age that wearing armour is incompatible with casting spells, it has become part of the zeitgeist, it is accepted lore. As such it is an integral component of the wizard's belief system. They believe wearing armour will undermine their ability and so it does. **Note that since this explanation is entirely mental, it allows for exceptions!** * In a culture where *everyone* wears armour, not for protection, but for style, or tribal identity, or rank, then 1 won't apply. (2 might or might not still apply depending on the details of the culture) * In a culture without 2, 1 would still apply if the armour is worn for protection, but an individual might don the armour for another reason: + "This was my mother's, I wear it out of sentiment." + "This stuff is heavy, wearing it at all times helps keep me at peak physical condition." * Even in a culture with 2, some individuals can still get away with wearing armour as long as they were not wearing it for protection: + One might learn that 2 isn't actually the case. If they were confident enough in their skills, they could wear it as an intimidation tactic: "I am so powerful the normal rules do not apply to me. Tremble in fear." (Note: They know they are not actually special, but it is useful to have others believe it to be so.) + One could become deranged and actually believe that armour and magic are still incompatible for normal people, but I'm special. They then go on wearing the armour as proof of their special status. [Answer] **Balance *is* in-universe.** *This is, of course, done for reasons of balance ... I'm looking for a sensible in-universe explanation*. Note that in fantasy settings there frequently are beings with powers beyond that of the gods. They may be called "Eru", "Ao" or "Dungeon Master"; in any case they are beyond caring for the worship of mortals, and care mainly for maintaining a form of balance. This balance allows for at least limited free will. It is in their interest to ensure that the the universe is not dominated forever by a single wizard with mind control and necromancy powers. Thus they shape the arcane powers to give wizards at least one Achilles heel, so there is always hope that such a tyrant would be overthrown. Although wizards draw on the arcane power created by the overdeity, they have no need to pray. Indeed they only depend on the overdeity for arcane power in the same way a fighter depends on the overdeity for the existence of iron (or food and water). Never-the-less the rules of reality that so limit wizards were created by an overdeity with an explicit interest in balance. [Answer] I've been beaten to the punch regarding the "iron has anti-magic properties" thing so instead, here's an alternate explanation based on one of the other rules: > > You can throw around fireballs, **create walls of earth**, fly through the sky, ... > > > If you can create walls of earth, do you *need* armour? Incoming arrow? Block it with a wall of earth. Incoming fireball? Wall of earth. Incoming sword? Maybe a smaller, well-placed pillar of earth to knock the guy's sword arm out of the way. Alternately, maybe a "Shield" spell exists, that creates a protective sphere around the caster. It would take mana to maintain, and more while it's under attack, but it would protect the caster from any and all attacks (and could be one-way so they can fire attacks out of it). A wizard who can cast a Shield spell or Wall of Earth spell might not think armour is necessary, regardless of whether it would reduce their magic ability or not. [Answer] Arcane magic involves drawing energy into your body from the world around you. Wearing something as solid as metal armor is to magic what wearing something over your nose and mouth are to breathing. You can deal with having your nose blocked if your mouth is free - so rings and pendants and the like aren't a major problem - but if you have your mouth blocked and need to pant, you're going to have a bad time, and so too if you're wearing a breastplate. Maybe some people can train themselves to work under those conditions, maybe no one can. Maybe some special material - like what we use for a surgeon's mask in our analogy - can be created to enable you to draw energy in...but maybe no such material exists that's both protective and allows that. Or maybe a spellsword can just learn how to draw energy differently, like a person can learn to breathe circularly or something. There are all kinds of different degrees that you could take here, too. Maybe even a ring or pendant is a little problem, if it's not specially enchanted to not obstruct the flow of magic. Maybe that same enchantment could be applied to armor if you could get someone capable of casting the spell *that much* despite an inverse economy of scale - or maybe that's not possible at all. And if you want these same principles applied to other types of armor, it may be that it's not the presence of metal but the presence of any kind of thoroughly-air-obstructive or insulating material. Maybe wizards DON'T wear thick robes in this world, or those thick robes are pushed aside by wind produced by drawing energy in, in a way that leather or metal armors aren't. In fact, maybe robes provide a sort of 'wind tunnel' effect to amplify the caster's ability to draw magic in! This mechanism also adds a neat approach to the lore behind retaining spells. Maybe the spells that you 'memorize' are actually just precast, and their energy rests against your body until you summon them forth. You can recognize a high-level wizard because there seems to be a slight wind going through his robes at all times, and you see a magical spark-light effect if he holds a shield for too long as the energies struggle to escape him and are aided by the shield's interference. Oh, and as for other types of magic? Clerics don't draw magic in through their bodies, they're given it by their gods, sort of like they have a breathing tube. And druids, if we want to allow them leather, have a more efficient mechanism of drawing magic that isn't blocked by non-metal armor, but only allows them to draw in very specific types of magic that can permeate through leather. Or maybe the druids *ask* the energy to join with them, and the energy itself tries to get through the leather, adding more force to get around it or something. Still wouldn't work for heavier armor, but that could theoretically get around some leather. If we hand-wave away how rigid leather armor generally actually is. xD [Answer] # The necessary gestures are precluded by protection. In some worlds, armor interferes with all magic, hence the answers talking about Faraday cages and magical charge. In earlier editions of D&D, armor specifically interfered with somatic components, the gesture part of a spell, but not with purely verbal spells. Additionally, not all armors are metal, and hide armor can still can interfere with spells. Given this, I like the idea that the **act of protecting yourself** is what interferes with magic. How does this work? The more armor you wear, the more likely that a given body part you might need to "open" up to the ether via gesture to draw power is covered and less likely to get you into the proper position to complete a spell. For example, perhaps your spell gestures require you to place your hand on a central chakra/chi node/magical organ, simply, you gotta touch your chest. Wearing armor means you can't effectively complete this gesture, and even some thick leather might occasionally catch you up in the complex act of tapping into arcane energies. [Answer] There's nothing forbidding a caster to wear heavy armor... unless they want to boil inside the breastplate. That's because channeling mana through our bodies is quite an exotermic reaction and it's easier to bear if you're wearing light-fluffy wavy clothes. Maybe you think that the heat could be bearable but ask yourself: would you be able to concentrate on complex chants inside a furnace at 40-50 degrees? [Answer] Depending on your setting there might simply be some analogy to the Geneva Conventions in place prohibiting mages from wearing armor at all. This could be because of some concept of honor or fair-fight philosophy. Regents/Generals may have had a problem in the past with troop morale. Foot-soldiers may have rebelled because they felt they were merely cannon-fodder and human shields for the mages. Putting these rules in place may have solved that problem. A historical example of such deliberate restrictions can be found in medieval times. The use of crossbows against christian soldiers was generally frowned upon or even forbidden. > > 29. We prohibit under anathema that murderous art of crossbowmen and archers, which is hateful to God, to be employed against Christians and Catholics from now on. > > > (from <http://www.ewtn.com/library/COUNCILS/LATERAN2.HTM>) [Answer] If I remember correctly, even in the Forgotten Realms there was a God of magic, whose clerics might not be magic users, but who was considered the creator and administrator of what magic was. It could be as simple as a dictate from the deity. Another possibility comes from mixing in some other themes of magic. It could be the souls of those capable of wielding magic are vulnerable to influence from spirits (ex: the main villain of the first book of the Inheritance series, Eragon, was overwhelmed by spirits). Could be, every magic sensitive in the realm is provided abjuration protecting against spiritual assault. Armor is a strong natural abjuration from physical assault. The natural physical abjuration might weaken the spiritual one, like a drug interaction, leaving the magician vulnerable to having his or her mind consumed. This would tap into Hermetic ideas of contagion. Or, it might be that the (pure) unbound body, robes of rank, and other accoutrements are a usually-not-talked-about somatic and material component to most (if not all) magic. This would pull in ideas from Egyptian and Oriental magic where, to make something happen, you had to demonstrate (somehow) your authority to be making requests. Or, magic might be a widely encountered force, and it might be mediated by tiny elementals and tiny spirits. This pulling in ideas from modern physics where particles communicate light (photons), gravity (gluons), and mass (higgs). Could be a scary armor scares away, or a strong natural abjuration drives away the spirits of most utility to the average magic practitioner. This could also help explain magic poor areas (if they exist in your world). But this approach is a supernatural restatement of the "metal short circuits/Faraday cages magic electricity" suggestion. [Answer] # Magic Waves If magical energy was being transferred from one point to another, it's reasonable that it might move in waves (in analogy to sound waves and light waves). If that's the case, then the magic wave speed (more specifically, the wave impedance) would depend on the medium the waves were traveling in. If the wave speed changed in certain ways because of a change in the medium, then there could be both reflection and refraction. Armor, then, might not only reflect magical energies, but set up standing waves of magical energy within that armor (and so within the magic user) that would be less than healthy to that user. The armor might refract the magical energy too, into directions that are difficult to control. This could also be why the magic user uses a wooden staff. If the staff had a magical wave speed that was in-between the wave speed of the user's body and the air, then there would be less reflection at the boundary between the magic user and the air and so there would be less energy lost in casting the spell. [Answer] I would say a couple options: * Heavy garments block the flow of energies around the body. Harnessing those energies is what makes magic... well... magic. * Movement: You need precise control of mind, spirit and... body. Heavy clothing interferes with those precise movements. * Bad energies in the garments/armor. How much violence did it take to make? Killing animals to make leather? Mountains destroyed to make metal? Energy expended to beat rocks into shape? Those energies - violence, death, destruction - leave it's own energy. That energy interferes/negates your magic. (Necromancers wear leather to harness that bad energy? Taint the good energy to raise the dead? Leather washed in blood is even more powerful... leather washed in the blood of humans more-so... Washed in the blood of wizards? Hasn't been tried yet... .. . yet...) * It takes pure materials and "good" energy to make proper clothing for a mage (in addition to heavy materials being bad and impure materials actually blocking magic)... that's why silk is better than wool... and why druids are known to dance naked under the full moon. * Ever try to call lightning while holding a lightning rod? Or wearing one? Magic pulls that energy through you... last thing you want to do is be grounded... (Further note: Don't use swords. I'd say ask my friend Steve... but he's a crispy mound now. He didn't listen.) [Answer] Wizards do not normally engage in hand-to-hand combat. Their primary offence is magic and, while they might use weaponry, they are probably best advised to run away because they will be facing those much better trained and, in any case, a good (or even mediocre) wizard is far more valuable than an ordinary soldier. Although a wizard may use magic defensively, they are most effective when concentrating their magic for attack purposes. Their best defence for most practical purposes is to hide behind something like a wall or in a good solid tower. Light armour may help, if necessary, to protect a wizard out in the open from ranged weapons but may be counter-productive if it significantly slows him in running for cover or prevents him from crouching behind whatever may give protective shelter. Wizards are essentially cowards - they don't dress to fight, they dress to run (and otherwise just to look good). [Answer] Interesting that you would even provide the link to the Weave and you haven't gotten a Weave based answer. Spell casting is less about 'casting a spell' and more about entering the non-physical world that this world is drawn upon and asking the very fabric of existence to rearrange itself to suit your needs. You need to unbind yourself from this world to see and interact with the Weave for spell casting to become reality. Encasing yourself in the frivolities of this world (read as 'armor') is to bind and anchor yourself into this world, thusly denying yourself access to the very weave that grants you your magic. Armor = binded to this plane = no magic. You need loosely connected flowing robes (at most) to disassociate yourself from this world and see the Weave Of course clerical magic gets around this as the clerics very core is bound to their God and can access the weave through their binding to their God and not need to enter the weave themselves (they ask the god of this world to alter the weave for them, while a spell caster must enter the weave and ask themselves). [Answer] From my 7 year old son - in all universes, all magic comes down to manipulating energy through some system such as psionics, ritual, familiar spirits, link to nanotechnology left over from a prior civilization, divine (or not) grant, etc. Metals are good conductors of energy (electricity, heat, sound, etc). Metal armor interferes with the mage's ability to control the energy they are manipulating by shorting it out. However, properly formed metal tools and implements can actually aid in the manipulation of energy (ever seen a radar dish? ), so the same should be true of magic. (Edit) I suddenly get an image of a mage with a parabolic metallic reflector cowl behind his head. [Answer] In a world with magic, everyone uses magic. Now, they don't memorize spells and wear robes. But every blacksmith uses magic to forge metal, every leatherworker uses magic to cure leather. Midwives use magic to birth babies, matchmakers use magic to find matches. Magic is everywhere, so everyone uses it. Every kind of *effective* armor must be enchanted, because unenchanted armor is garbage. The other side has enchanted swords, and they will cut through your unenchanted armor like butter. Even human bodies are enchanted. From the little things, protective magic placed on them by midwives, mothers, fathers. Ancestral blessings placed on them through prayer wheels. Everything uses magic. Wizards are people who collect magical secrets in the form of spells. In order to cast these spells, any enchanted items you have on you have to be taken into account. The magic that infuses weapons and armor doesn't work well with most wizard magic. Their presence on the body warps the spells. The "armor" that a wizard must wear is enchanted with effects that help them cast their spells, and the "weapons" (staffs, wands, orbs) likewise. These enchanted tools and clothing don't protect you against swords, at least not passively. Instead, they enhance and enable you to cast spells. If you could find a armorer willing and able to make it, a wizard could wear unenchanted plate armor just fine. Wouldn't do him much good against anything other than hail stones, as any crude dagger used by an urchin with even a modest enchantment makes your plate armor useless. This also permits there to be "wizards" who *do* use armor and weapons. They either use a different form of magic/spells, and/or they have unique enchantments on their armor/weapons that permit both weapon use and magic use. Such "spellswords" may not be able to cast as powerful a spell given the same level of training as a traditional wizard. [Answer] Quite related to the mana-based approach on interference between magic and metal. However, I noticed we can also use this argument to exclude ordinary cloth. To do that, we could simply say that wizard robes are woven of a special material, say, unicorn hair. And we could further say that unicorn hair is not just the only material that allows you to wear it and still channel mana, but rather actually a necessary conduit of mana in first place. That would mean that every piece of unicorn hair cloth missing or not touching both the wizard's bare skin and the air around him is a waste of mana-channeling capacity. Of course, wizard robes extending down to the floor could still be justified quite well: As long as the cloth is connected to other unicorn hair cloth, it still can somewhat contribute to mana channeling, although not as much as cloth with direct contact. (Or actually, you could leave that justification out - would be fun to have your wizards run around in tight unicorn hair suits.) While there might be metals with the same capacity to conduct mana, you could easily restrict that property to the most special, but also most clumsy metals, like gold or also electrum, a melding of gold and platinum present in many fantasy universes. Believe me, even if you go for mail, goldmail and electrummail are already quite heavy. Mithril is often used as a metal that's very lightweight and incredibly sturdy, and certainly you'd have a hard time to justify it cannot conduct mana since it's one of the most unique materials in existance, but it's also incredibly rare. In most fantasy stories where mithril is present, only the most skilled dwarven metallurgists are able to produce it, let aside the fact that the needed metals are among the rarest as well. And as a matter of fact, you don't even need to include mithril in your universe (although most people would probably be a little bummed if you didn't). [Answer] If you take mana as energy that is manipulated by a mage and the mage is the source of this magic/spell, then when the spell is cast, the energy radiates from the mage and reflects into reality (doesn't matter what system it is, just that the energy is released). Just as spells can not pass throught armour (unless it is specialized for it) when it hits the hard material, such as metal, the spell takes effect (just like when electricity reaches a component in a circuit). (Fireball hitting a human) Staves are not made from metal, because it stops the energy from flowing (electricity -> ground), while formerly alive materials such as wood or bones are used to flows of magical energy. Wearing armour thus presents several dangers to the caster: 1. Mail armour mesh could stop the flow of energy from the caster, just like a cage does for electrical discharge. 2. With added size and weight, there is a chance, that the spell will discharge into the caster and not the intended target. 3. Many magic systems require some sort of sense, to cast the spell successfully. (The caster has to see the target-offensive spells, the target has to hear the caster-controlling curses, sound from caster must spread-thunder voice, etc.) So the caster can not wear a helmet, but instead wears a big hat, to prevent from being blinded by sun. 4. Because of elemental nature of some spells (lightning, frost) some spells could also target the caster, if he wears metal objects. In my world I compensate for this with using rare highly conductive materials (mana crystals, gold, silver) or using enchantments and runes, to artificially infuse the material with magic and thus making it conductive. Thinking about mana/magic as if it was electricity and/or radiation/light, helps you establish basic rules. And make reasonable and strongly set rules. [Answer] If we try to apply game rules to the in game universe logic wizard spell casting is primarily a mental exercise as indicated by dexterity not being of no relevance as could be expected if intricate and complex set of movements is required. In addition not all spells in the wizards list have somatic components I.E don't require movement and in fact some bards can ignore the adverse effects of armor presumably because their spells are "simpler". Taking that into account it is reasonable to assume that the problem with armor among wizards lies in effect wearing it has on the mind of the wizard or in other words a wizard can only cast spells when he can convince him self he can and since in FR setting arcane magic of the wizards relies on vast and old traditions maybe wizards struggle with armor because their whole concept of "wizardness" is constructed that way. ]

[Question] [ Humans have grown fat, complacent and cock-sure of the certainty of future progress, arrogantly expecting to [build minds in their own image](https://worldbuilding.stackexchange.com/questions/6340/the-challenge-of-controlling-a-powerful-ai). They even dream of building themselves a city, [with a tower that reaches to the heavens](https://worldbuilding.stackexchange.com/questions/8866/where-to-anchor-my-space-elevator), so that they may make a name for themselves in space, where they wish to blacken the skies with their footsteps and besmirch it with their greedy mining robots. Too bad for them and their silly dreams. They won't get the chance to return to the Moon, not for centuries. Why? **Because a new dark age is coming.** **What are the omens, the dark messages that foretell the coming of this black age? What is to bring this dark age about?** If that was too poetic, imagine a 90% drop in GDP/cap, a 60-70% drop in life expectancy, general loss of culture and knowledge, as well as a drastic drop in public and private safety and security. What matrix of factors could lead to such an outcome? In order to objectively judge a "good" dark age entry point the following criteria have to be met: 1. No Daemon-ex-machina to save us from the relentless march of Progress. So out go aliens, asteroids and supernovas. **The cause must start here on Earth and be the logical** (dialectical, to borrow Marxist terms) **conclusion of our own progress** (or was it hubris?). While those are possible (and thank you for the pre-edit answers) they are now outside of the current scope. 2. **A clear and plausible mechanism to get us there from here.** If a doom-bringer is visible from a mile away, presumably people would not go there unless severely pressed from all other directions. (i.e. the Singaporeans knew the dangers of [unshackled AI](https://worldbuilding.stackexchange.com/questions/8915/shackling-strong-ai-second-attempt), but the desperate circumstances of a 3-front war while outnumbered 1000:1 forced their hand) 3. The disruption must be **unstoppable** once started, **persistent** (what's left of humanity can't simply go back to normal in 3 years) and **widespread** (i.e. Switzerland can't simply sit this one out). Pockets of relative high-tech might persist, such as the Massachusetts Institute of Theology's department of Applied Philosophy, but progress in any scientific field must be severely curtailed and even reversed. [Answer] I haven't read through all the answers in detail, but there is one obvious possibility that I don't see anyone else having really mentioned so far: **peak oil.** Or more generally, *peak available resources.* First a bit of background. "Peak oil" refers to the moment in time when oil production (or extraction, rather) reaches its maximum rate, or "peak". This can be on the level of a single oil well, or on the level of the entire world. I'm going to talk about peak oil here, but the same concept applies to any resource which is non-renewable within human timeframes and which the society depends on. **A very large fraction of our world's current energy mix** comes from fossil fuels, and a large fraction of that is oil and gas, which are both for all intents and purposes non-renewable in time spans relevant to humans. If you (for some value of "you") are consuming a resource at a greater pace than it is renewed, it follows logically that at some point you will run out. (I'm sure there's a way to prove that using MathJax, but I don't think I need to.) Peak oil isn't about *running out* of oil, per se, but it does have the consequence of running out of *a stable supply of cheap* oil. When all that is left is deep water oil, oil from tar sands, and so on, you may very well technically still have lots of oil left, but you won't be able to get it out of the ground for cheap, and you might not be able to get it out of the ground at the rate needed. So the price goes up, causing a much greater fraction of the world's total economic output to go to energy extraction just to maintain the amount of energy required to maintain the status quo. If you normally pay 2% of your income for electricity and suddenly that figure jumps to 10%, *something* has to give. Now scale that up seven billion or so times. Our current oil extraction rate is on the order of 80 million barrels per day; one barrel is about 160 liters; that means we currently go through some *13 billion liters of oil every day*. When the price goes up, demand eventually goes down, which is likely to cause the price to go down; rinse and repeat a few times with violent fluctuations in price both up and down as the world society at large struggles to recover. Alternative energy projects are likely to get scrapped during low price periods, and funding is likely to be scarce during high price periods. Experts debate when peak oil will happen, but **I have yet to see a credible argument** that a finite resource will *not* **eventually** peak and start to decline. If a society has grown used to, or even depends upon, that resource, then the decline in the production rate of that resource is going to have an impact on the society. **The western world today** is largely in such a situation with regards to oil. We use it to manufacture things, we use it to transport things, we use it to provide heat and light (by way of electricity), we use it to grow food (by way of farm machinery, which itself is constructed using oil and petroleum products), we use it to make toys and kitchenware (plastic!), we use it to mine other primary resources, we even use it to construct and maintain "renewable energy" sources such as wind power plants or solar cells. We know for a fact that *on a human time scale, oil is finite* and thus if we keep consuming it at a fixed rate we *will eventually* run out; a plausible argument can even be made for that we are about to hit the extraction rate decline *now to soon*. This satisfies your first two criteria: **it starts here on Earth, is a logical extension on our current situation,** and **there is a clear and plausible mechanism to get us from where we are to this situation.** That leaves your final criteria, that the process is *unstoppable, persistent and widespread.* Let's take those in turn. **Unstoppable:** Once you've burned the oil, or made plastic, or whatever else you do with it, you really can't put the genie back in the bottle. Reuse of materials can go some of the way, but not all, and eventually entropy wins out. We have yet to perfect the perpetual motion machine. You can invent new technologies like cold fusion power plants, but our past results in such endeavours are not promising and it almost certainly won't get easier in an energy-constrained environment, as I alluded to above. As we require energy to even extract oil from the ground, read up on the concept of EROEI ("energy returned on energy invested"). By the time you only get a few times more energy out of the oil compared to the energy investment to get it out of the ground, extracting the oil for the energy doesn't make sense any longer. And if you do still extract it, you leave even less than you used to have for the future. **Persistent:** Same as above; if by "normal" you mean our current western lifestyle, that is heavily dependent on oil (and other fossil materials) and if those aren't there, there's no going back. You can make various changes to draw out the process of change, but you can't at time $T\_{n}$ go back to the state that you had at time $T\_{n-1}$ in any plausible manner when going from $T\_{n-1}$ to $T\_{n}$ involved some irreversible process such as running an engine on some of the energy you used to have, and the energy used to go from the state at $T\_{n-1}$ to the state at $T\_{n}$ was greater than the total energy added to the system during that specific time period (whether that time period is on the order of microseconds or centuries). **Widespread:** A fairly small number of contries are net oil producers these days and thus are capable of being net oil exporters. Everyone else must import some or all of their oil. If, say, Saudi Arabia were to hit peak oil and face a serious decline in oil extraction rates, it would have a widespread impact because of Saudi Arabia's large share of the oil export market. And sooner or later, that will happen. It already has happened to Norway, as well as a number of other countries. By the time people are struggling to put food on the table for themselves and their loved ones, or keep warm in the winter, and that goes on for year after year, I wouldn't really expect back issues of *Nature* or *the Astrophysics Journal* to carry much value other than in terms of how much warmth you can get by burning them, nor would I expect people to spend a lot of energy on keeping Wikipedia running or accessible. At that point, while some knowledge would almost certainly be retained, a lot of knowledge that doesn't have day-to-day practical uses in such a situation would likely be lost. With how many rely on online services already, it is far from impossible that some amount of knowledge could essentially be considered lost immediately once those services shut down. For some further discussion on this, one might consider the words written by John Michael Greer; for example, back in April 2007, in [Cycles of Sustainability](https://web.archive.org/web/20070418104448/http://thearchdruidreport.blogspot.com/2007/04/cycles-of-sustainability.html), > > Does this mean that peak oil can be ignored, because it poses no threat to industrial society? Hardly. As oil production worldwide continues to contract, and conservation and alternative energy reach the point of diminishing returns, oil prices will spike upward in turn, rising even higher than before and unleashing another wave of economic and social disruption. Just as the economic contractions of the 1970s and 1980s spawned intractable unemployment in most industrial societies and launched a process of downward mobility from which many families never recovered, each wave of economic contraction will likely force more and more of the population into a permanent underclass for whom the abstract phrase “demand destruction” plays out in a downward spiral of impoverishment and misery. > > > In such a future, the periods of apparent recovery that will likely follow each round of energy shortages and demand destruction will provide little room to rebuild what has been lost. Those periods will, however, make it exceptionally difficult for any response to fossil fuel depletion to stay on course, so long as that response depends on market forces or politics. Each time oil prices slump, the market forces that support investment in a sustainable future will slump as well, while governments facing many calls for limited resources will face real challenges in maintaining a commitment to sustainability which, for the moment, no longer seems necessary. Thus the collapse of public and private funding for the alternative energy sector in the aftermath of the 1970s will likely be repeated over and over again as we stumble down the long downhill side of Hubbert’s peak. > > > and in the followup [Where are the Lifeboat Communities?](https://web.archive.org/web/20070429185615/http://thearchdruidreport.blogspot.com/2007/04/where-are-lifeboat-communities.html) a week later, > > If the industrial world faced the sort of quick linear decline imagined by so many pundits of the Seventies and the present day, the transition from a modern lifestyle to a sustainable one would be much easier. Faced with the certain loss of familiar comforts and a future getting steadily worse than the present, many people could come to terms with the difficulties of subsistence farming and learn to enjoy the acquired taste of its pleasures. As I suggested in last week’s post and elsewhere, though, this luxury isn’t one we can count on. > > > Instead, the most likely course for the decline and fall of industrial civilization is a cyclic process, in which periods of respite and partial recovery punctuate the downward curve that leads into the dark ages of the deindustrial future. [...] > > > [Answer] It all begins in a craft brewery in Central Florida. A single batch of yeast mutates, becoming extremely resilient and prolific. It survives the fermentation process, the bottling process and even its own consumption by thirsty humans throughout the state. Swimming unharmed in the acidic stomach juices of contented beer connoisseurs, the super yeast feasts upon whatever its new hosts eat, dutifully turning all sugars into alcohol. As a result of these hearty little beer makers, everyone who drinks even one bottle of this special brew stays drunk forever. The customers are happy and the brewery owners are ecstatic! Blind to the impending apocalypse, they scale up production and start distributing the superbrew worldwide. To make matters worse, the mighty yeast is contagious. Sober people can contract eternal inebriation from a single french kiss. Even the teetotalers aren't safe. Que the planetary funeral dirge. Truck drivers lose their sense of balance; they can no longer drive in straight lines. Nuclear power plant workers' eyes go blurry; they can no longer read the gauges. Food and power distribution, along with every other symptom of modern civilization collapses in a drunken stupor. Weeks pass, with the wonder yeast consuming everything its hosts eat, flooding their systems with alcohol. They grow thin and their skin turns grey; starvation concealed by sedation. A mellow buzz transcends the world for as long as the sugar supply holds up. Then the food runs out. The yeast stops and its victims sober up after a month long binge. They are tired and their heads ache mercilessly, but more important to them in this moment is, they are starving. Running through the streets in a ravenous rage, they begin to eat each other along with the few remaining survivors who have somehow remained uninfected and sane. Welcome to the drunken zombie apocalypse. The sloppy staggering dead. [Answer] This scenario exaggerates current trends. I think mankind will come to their senses before it gets that bad, but you never know ... The income disparity between managers and skilled workers/engineers continues to grow. Over several decades, the middle class shrinks. Using global trade agreements, the "one percent" minimize their tax burden. Infrastructure crumbles. A generation grows up where the children of the "one percent" go to expensive boarding schools and then to university to study law or business administration instead of STEM (Science, Technology, Engineering, Mathematics). The "skilled professional middle class" cannot afford to raise and educate more than one child per family, with both parents working full time to cling to a semblance of affluence. The masses go to the underfunded public schools and learn nothing much. In the 2040s the last of the pre-crisis professionals retire and the house of cards falls down. Look at this: <http://en.wikipedia.org/wiki/DINKY> Or consider the European standardization of university systems, which "optimized" critical thinking away: <http://en.wikipedia.org/wiki/Bologna_Process> Consider the German system of vocational training, which is "under attack" by global standardization on the American model of education: <http://en.wikipedia.org/wiki/Dual_education_system> **Follow-Up** regarding the "critical thinking" comment -- I mentioned that I was exaggerating trends, but I don't think I'm completely off the mark. In much of continental Europe, Bologna and related reforms at the same time took choices away from the students. The theory that a completed bachelor's degree qualifies for at least *some* jobs in the field within three years turned those years into a rat race with little chance to take supplemental courses beyond the minimum required, especially once realistic times for an ECTS point are taken into account. The two years for a master's degree are not enough to make up for this *and* take exams and write the thesis. The previous system of *Universities of Applied Sciences* for the short/practical course and *Universities* for the long/research course gave students aiming for a career in academia more time to think for themselves and select their focus before the thesis. But Bologna is just one detail. [Answer] All right, by the terms stated in Serban's question (which I like a lot), there's no better answer than Michael Kjörling's Peak Oil scenario. Bobson noted, "We can see this coming and we *still* aren't managing to change it." In other words, it's not just a hypothetical - **it's something that we are actually doing to ourselves and to the planet, now.** If you look at serious studies of societal and civilizational collapse in history, such as the works of [Joseph Tainter](http://www.goodreads.com/book/show/477.The_Collapse_of_Complex_Societies) and [Jared Diamond](http://www.goodreads.com/book/show/475.Collapse), it becomes achingly obvious that we're not a different species than the Romans, or the Mayans, or the Easter Islanders, or the Anasazi, or the Achean Greeks, or the Greenland Norse, or... well. Michael has answered the question, as posed, authoritatively. Nonetheless, I'm going to throw another answer out there. I'm going with a pandemic. Not an exotic one - a new strain of SARS, say. Not genetically engineered, not introduced by aliens or military research labs. Just a bad strain of comparatively natural virus. It's not even particularly bad compared to some of the doom plagues already suggested. It kills several million people worldwide, but on a planet of 7 billion that's not much more than a rounding error. [Captain Trips](http://www.goodreads.com/book/show/149267.The_Stand) it ain't. (I'm not being callous here - the immensity of that number, *seven billion*, is important to this narrative.) No, the reason our BADASSARS is so destructive is that it mutates pretty quickly, so vaccinations and survivor immunity don't provide much protection. It also has a long latency in the human organism and is exceptionally contagious via many vectors, including the dreaded airborne vector. (It gets through filters pretty readily too.) In short, the only way to stay safe is to stay the hell away from, well, everybody. As a kicker, let's postulate that the terminal symptoms are insanely hideous, like a Krokodil addict with Ebola. The *risk* of contracting the disease is intolerable, even if intellectually you know your odds of survival are good. In other words, it's pretty carefully crafted to disrupt human contact and society. (I know this because, well, I designed it that way for your reading pleasure.) And here's where that seven billion number comes in. BADASSARS only directly kills several million people, as mentioned. But *indirectly* it kills hundreds of times times as many. We are seven billion people on a planet that, *without modern agricultural technology and transportation/distribution networks*, could feed maybe one billion. When the people of the world begin to understand the implications of BADASSARS, the networks unravel. Technological agriculture grinds to a halt. *Oilfield workers won't even come to their jobs anymore*. Nobody can risk going to stores. Ships won't sail. Soldiers and cops desert. Nobody tends the electrical generating stations (which are running out of fuel anyway.) Why? because people are terrified of each other, because everyone is a monster in each other's eyes. They shoot each other but are afraid to loot the bodies. Civil order is lost. Doomed citizens, in their hundreds of millions, flee the cities, because ([to coin a phrase](http://www.urbandictionary.com/define.php?term=Hell+Is+Other+People)) Hell is other people. After a few years, BADASSARS subsides. It has mutated out of its virulent phase. Still, the world we know - the world of medicine and cars, of electric power distribution networks, of hot clean water for washing up and cold clean water for drinking, of enough food that won't make you sick, of shoes you can afford, of music you don't have to play yourself (and let's face it, *you suck* at trying to pick out that Richard Thompson song on that guitar you can't tune), of a safe home and a safe community - lies in ruins. It's an unprecedented loss of human life, and the survivors, except for a few sociopaths - oh *goody* - are likely to be traumatized. Hey, did somebody order a Dark Age? [Answer] Environmentalist scientists working on oil-spill cleanup technology design a new bacteria that eats oil. The bacteria releases the hydrogen as helium to prevent combustion, and turns the carbon into ash. It then dies when it runs out of food. The product is hailed as a huge commercial and environmental success and is rapidly used across the globe. Because it would be bad if the bacteria contaminated oil fields, it's rigorously controlled by the original company. They provide fresh copies from the original batch every time, and police it to make sure all the bacteria dies each time. Unfortunately that control comes at a great expense, and not everyone wants to pay for it. Bootleg copies are acquired and spread, and are allowed to continuously mutate. Eventually one batch mutates into a form that will also eat many common forms of plastic. Because it's inefficient at first, it's not obvious that it's contaminated something and spreads rapidly throughout the world, and eventually makes it into 99% of the world's oil supply. Now the bad stuff starts to happen. Oil fields and reserves are eaten away, driving prices up sharply and heavily disrupting the economy. In the long term oil is removed as an energy driver entirely as the supply is entirely eaten away. The effect of eating plastic is nearly as bad. Many clothing options literally start falling apart as they're consumed. Insulated wires become un-insulated, disrupting power transmission, computers, and phones. Plumbing fails, leading to widespread sanitation issues. City infrastructures that depend on plastic fail as well, causing areas to go without water or to flood. Food packaging fails, leading to spoilage and mass starvation. The economy is destroyed, and is unlikely to restart without cheap energy to drive it. Scientific investigation is stalled by the need to focus on survival, and without a robust, efficient economy it's unlikely to start again except in isolated enclaves. Entire disciplines that were largely dependent on plastics are lost - others are possible but need to be re-thought from the ground up. [Answer] Multi-national corporations get to the point where their income rivals the GDP of 90% of the worlds countries, while at the same time because of greed in the financial and banking markets world currencies go into a recession. For the first time, a corporation purchases an entire bankrupt country, taking over the government infrastructure and turns it into a private kingdom. Other multi-nationals follow suit until a large part of the developing and developed world is privately held. Corporate branding is everywhere, few people bother to create anything without corporate funding. A new type of serf is born: the happy consumer. Content to work the jobs that the corporation provides and consume what the corporation sponsors, most people stop trying to improve their own lives. Knowledge and skills that don't directly help the corporation are not encouraged and over time are lost. Without any reason to strive, humanity withers. Birth rates decrease, civilization fades. [Answer] Religious whackjobs invest vast amounts of money to subvert governments. They force destruction of all technology above (whatever level you want to use), dismantle human rights and install themselves as theocrats. How long would it take to destroy civilisation in this manner? Add a big war and a plague to speed things up a bit. [Answer] There's a very nice scenario descibed in Lars Wilderängs book "Stjärnklart". Unfortunately it's not translated to english yet. I added some of my own parts to the story. SPOILER ALERT Suddenly, in Sweden and elsewhere around the globe, electronic equipment starts to fail, the car repair shops experience a large influx of customers, cell phones go black and payment systems stop working. Modern day society which is largely optimized for high efficiency rather than robustness, rapidly falls apart as payment system, transport vehicles and other infrastructure become unusuable. Eventually, scientists discover that the dead electronic equpiment is covered in gray dust, which turns out to be caused by nano bots operating on and through electronic conductors, multiplying by consuming the electronics itself. Maybe it's a renegade government project? Maybe it's just an evil scientist who likes to watch the world burn. In a few weeks, faced with starvation, dehydration and lack of sanitation, civilised people realise that to survive, it's every man for himself, or at best, every town for itself. In the power vacuum created by striking police officers who have no reason to do their job, local warlords are born. Since most food production today is completely dependent on both electricity and oil, which must be transported, the wast majority of people starve to death within a few months. The nano bots eventually face the same fate as they run out of electronics to consume, but the world they leave behind is almost completely void of any working modern day technology, and all that remains of humanity is a few million savages. [Answer] Nuclear war, brought on by misunderstandings and accidents after several decades of self-serving aggressive posturing by politicians in countries who have them, would utterly devastate the economy and human environment. I am not sure we were so far away from that in the 1960s-1980s, and it is not inconceivable the danger could rise again. Then, see the Dark Ages of Europe. Superstition and belligerent ignorance can go a long way towards driving out and keeping away progress: combine "technology did this to us" with any of the more aggressive forms of fundmentalism (religious or not), and you won't be out any time soon. [Answer] Extreme but effective , a bunch of ridiculously powerful aliens notices we are on the edge of extinction (and unaware of it) as 2% of us are consuming most of the resources and the others are starving, and the planet cannot sustain us anymore, and more boring stuff nobody really cares about. Well, they decide it's time to reset Earth to factory standards to give us another chance. For example they could freeze us (teleport plus suspension, see Star Trek TNG episodes "Relics" and "Second chances") for a couple millions years while the planet heals from our damage. It would be very hard at first, but in a few decades I think we would be able to face the situation quite well. [Answer] One mega natural disaster is all it takes. A comet fragment (aka alien invasion), a massive tidal wave, the magnetic core of earth stopping and losing its magnetic field, earthquake -- nature will screw mankind in the end. In geological terms it is certainly feasible with an alarming amount of probability. The sun will stop burning in a long - long time, I wish I would be there to witness that...but will mankind survive even that long? To generate ideas, just look around scientific events of note and read apocalyptic science fiction. Judging by Mai-Lai and other events where mass genocide took place - moving to dark ages is something we as humans can bring on ourselves. We do not even need nature to do that for us- its human nature and not nature that would be the culprit. Theologically, the End of Days will terminate the world as we know it. Satan's judging hour will commence. Mankind will have breathed it's last. TEOTWAWKI - The end of the world as we know it. The acronym among survivalist and prepper communities-they think they could survive anything.. I like the idea, but if Noah's flood starts again, I am sure you will need a boat as there will be no place to hide and nowhere to run. Human diseases may exterminate a massive amount of human population. Sterility in future may disable the ability to procreate, and sex just becomes a way to entertain ourselves. After sometime vestigeal mechanisms kick in and we lose our ability to get orgasms. Thus reproduction becomes an act of gore. Finally mankind starts to copulate with animals and a new breed of hybrids take form, after years of experiments and failure. Somehow we become more animal than human and thus our biology adapts to our thinking pattern. There are N number of things that can happen. The dark ages are essentially an age of lack of sanitary hygiene, disease, wars, lack of medical knowledge,no electricity, violence based politics. To get any of that visit any backward area of India or visit places like Liberia in Africa, you should get the meaning of the word Dark Ages. [Answer] I'd say we're already heading for a new dark age or worse, from one or more potential threats. Perhaps the worst of these is climate change. As in, we may not be able to stop it and we may not survive it at all. The omens were scientists speaking out about this for the last forty or more years. It may be inevitable because the momentum might be impossible to undo even if we stopped burning anything right away. It may wipe out life as we know it due to potential positive feedback loops which may be impossible to stop. [Here is a good TED Talk summary about how we're likely in deep deep doo doo from climate change.](https://www.youtube.com/watch?v=A7ktYbVwr90) (positive feedback systems are mentioned at 12:00) We'll be lucky to get off as easy as a mere dark age. There are also a number of compounding factors, such as loss of healthy ecosystems due to natural habitat loss, extinctions, pollution, ocean acidification, over-fishing, etc. Then there are other deadly threats which could get out of control and contribute to these problems and/or create new problems and threats. There are several very large powerful corporations doing potentially devastating things to our planet health, such as planting aggressive cross-pollinating GMO crops, hydro-fracking ruining clean groundwater, creating bio-engineered viruses, creating new pollutants such as micro-particles, polluting, etc. Also there are all of the political/economic issues and all the weapons we have, including nuclear weapons, and their potential to ruin our electronics, power, information systems. Human thinking needs to change to avoid this. Corrupt economic, social and political thinking have lead us to unsustainable patterns of ever-increasing resource abuse which generate and sustain economic and political doctrines that tend to keep us on paths that will never be sustainable. A 90% drop in GDP isn't a catastrophic effect - it's a measure used by a system of thought that will cause us to destroy our planet (if we haven't already) and that needs to be re-understood in a way that won't have us striving for infinite "economic growth". An omen of this was the physicist who pointed out that the laws of thermodynamics also apply to economic models - basically pointing out that it's impossible to increase consumption forever within a limited system such as the earth. [Answer] Bear in mind that dark ages end with enlightenment, and when enlightenment ends we lapse into darkness. So what you need, then, is a force conceived outside of enlightenment. Maybe a theological force; a religion with a manifest destiny to take over the world. It would have to be authoritarian to prevent escape to rival faiths, and conservative to ensure that it brutally resists efforts to advance another enlightenment. Gee, just thinking about it that way is scary. I'm sure glad we have no religions like that anymore! [Answer] A self-duplicating nanobot manages to escape the science lab where it was born/created due to (*natural disaster or other freak accident here*). This nanobot runs off electricity and spreads across any metal surface. It was supposed to be an early prototype for self-mending armor, for military vehicles. However, now it just uses material from the air and electricity to quietly duplicate itself across the country. It was programmed to spread first, and then fill in the holes. This goes unnoticed for so long - it manages to attach itself to nearly every metal surface in the world. Finally, the explosive growth is noticed as it starts to eat a substantial amount of electricity to continue its growth. But its too late, they have gotten into every electrical source available and consume all of it, no more power for anybody else. It was designed to be armor, attempting to destroy it is proven impossible as it replicates too quickly. It is then proven that they are too small and widespread to prevent accidental entry into any new facility, making new constructions just as worthless as the old ones after only a few days. The only solution is to completely abandon the energy infrastructure we have created so they run out of energy. Losing all access to electricity, society loses progress in nearly every area as the world goes dark and waits to be able to use electricity again someday - assuming these nanobots don't just "sleep" when they run out of power. [Answer] Two scenarios which really scare me. Both are described far better than I can in the back-story of Vernor Vinge's *a Deepness in the Sky*. **Omnipresent surveillance**. We are already a long way down this path. What will happen when literally every action you take is recorded forever, when advanced algorithms are deployed to comb all that data for anyone who is not fully conforming with the way that they are supposed to be living? My view is that it leads inevitably first to a tyranny worse than North Korea, and then to the complete collapse of civilisation. **Over-optimisation**. In some ways this is even scarier as it is a road to hell paved with the best intentions. Society continues to automate and to deploy weak AI to manage everyday resource allocation and logistics. We appear to be entering a golden age where we can work less and play more. But the robots are creating an ever more optimised system of increasing complexity lying ever closer to the "edge of chaos". One day we slip over the edge and the entire civilisation falls apart. Perhaps we need terrorists and nationalists to inject enough local inefficiency to stop this latter disaster. Trouble is, the push us down the path to the former. The third possibility that scares me is that of **environmental collapse**. Other answers cover this so I won't expand, other than to say that slow environmental degradation could be the route to the collapse of an over-optimised global society. [Answer] You can look to human history and the Dark Ages after the burning of the Library of Alexandria for an answer. Religion can very easily set us back hundreds of years. The current conservative-leaning climate in America and various European nations is already successfully stripping rights from women and other minorities, and a lot of conservatives find a lot of evil in how easily we converse and live through technology (while using it themselves, of course). Religion combined with the fact that we are set to run out of fossil fuels in our lifetime could certainly be impotus enough for another dark age. [Answer] Well, I don't know about historical accuracy or realism, but I'm going to go ahead and say it: Aliens. Imagine a scenario similar to what happened to the Aztecs. An alien race, hell bent on conquest, invades the earth with their all powerful spaceships, whose mere presence destroys all our electronics via an almost aura-like EMP field. The humans try to fight back, and actually manage to repel the overtly-arrogant aliens, who were actually here without military sanction! And then someone catches Andromediac Flu (Or something, but you get the idea.) The disease is incredibly virulent, and does not differentiate between race or gender or sexual orientation. It is a terrifying disease that provides a slow agonizing death. The governments rush to contain it, but the alien invasion has left them undermanned and underequipped. Eventually, the plague subsides. All the survivors are now immune to its effects, but the damage has been done. A drastic drop in life expectancy and a terrible lingering paranoia that will damage the psyche of all mankind for generations to come. TLDR: Alien space flu. Edit: Just got home and realized I crafted a reverse War Of The Worlds storyline. Well, it makes sense that they would've been immunized to something we weren't anyway. **Well okay, from earth then.** Presenting 'The most delicious food in the world!', a vegan-approved drug that makes everything you eat taste 10 times better! Even the humblest of fried foods will blow your mind! This drug creates a boom in the food industry, and everyone is now on their quest to find better and tastier foods! Then it all goes downhill. People grow fat. Not just any normal kind of fat, but too fat to go about their business as normal. Infrastructures crumble as the people who used to run it can no longer get to work on time, if at all. Even the chefs who used to cook the food that caused this problem can hardly continue. Mass diabetes afflicts everyone, and people begin to die. There is no escape. Eventually, the last healthy man looks down upon the empty streets filled with food wrappers and abandoned fast food stores, and realizes that he has perhaps witnessed the fall of humanity as we know it. TLDR: Wall-E without access to space flight [Answer] There are a few scenarios, and you can make up more by combining any 2 highly disruptive events (disease, volcanic ashes, meteor shower). One of the events to explain the fall, the second event to make it unstoppable. Inspired by Perry Rhodan: A new game comes out (World of Warcraft 2) and game addiction slowly builds up. Motivation of people drops and more and more people start working only the bare minimum necessary to live and game. Once the global number of addicts reaches 10%, a tipping point is reached. University enrollment drops, social systems like food stamps and free health care become too expensive to maintain, some companies go bankrupt due to lack of customers, tax income of nations falls significantly, national debt raises at record speed. In that situation there's a great famine, caused by a combination of bad weather, bugs, and the lack of workers. The famine doesn't hit the 1st world as hard because they use their private purchasing power to buy food from 3rd world countries. As a result, the famine hits many 3rd world countries with death tolls comparable to those of Ireland in the 19th century. Governments fall, making these countries unavailable to purchase food from for the west for the next harvest. With the global game addiction, the world fails to address the causes of the famine. At the next harvest, famine hits the west, which already has it's resources strained to the limit. Death tolls are in the hundreds of millions and global trade collapses, which leads to rise of religious fanatics and nationalists, who manage to eradicate the game addiction with simple yet effective means: reeducation camps and death penalties. With global trade collapsed, many people dead, and nationalists and religious fanatics in power, universities teach the party line rather than actual knowledge, and wars start wherever ideologies clash, or opportunities arise. Communication and electric infrastructure is hit as priority target. Killer satellites disrupt global communication. The Internet ends. Empires rise and fall. Resource rich parts of large countries declare their independence (I'm looking at you, Texas). By the time the new world order stabilizes, many of the global oil reserves have gone up in flames, taking entire industries with them. Electricity has become unreliable, therefore old nuclear power plants are used long after their planned lifetime, leading to the occasional nuclear accident. Local branches of once worldwide corporations have been forcibly nationalized. The internet has been replaced with a series of national computer networks, containing a fraction of the original information. Scholars who dared to speak against the party lines have been cleansed. [Answer] Politics. My answer is similar to **Dunk**'s comment to **Red Sonja**'s answer. I think that RedSonja's answer is plausible on a national level but not on a global level. This answer also has similarities to **David Fass**'s BLS answer and **o.m.**'s educational reforms would help as well. Stagnation is generally sought by those already in power. It helps them keep what they already have. Change is always dangerous for those in power. Look at most eras of world history and you will see that the powerful generally seek to maintain the status quo. The idea of "fairness" spreads throughout the world. No one is allowed to receive more than anyone else no matter how much they work because it isn't fair that someone has a bigger TV than his neighbor just because he worked harder. This is implemented through several methods: 1. Orchestrated riots would prevent anyone from speaking out against the "New Idea." Look at Berkley, CA, USA for how that plays out. Hint: rioting to prevent opposing views from being spoken is "free speech." 2. Social peer pressure. Anyone with a fancier car, bigger house, etc. is ostracized. Note that this won't affect the truly wealthy since they just won't care but it will be effective against the low and middle classes. 3. Pay caps to prevent people from getting more by working smarter or being better at a job. 4. Hours worked per week caps. This is in the name of fairness to allow more people to work but prevents someone from getting more by working harder. France has something similar already implemented. 5. UN mandated "reparations" paid from wealthy nations to those who unfairly don't have the wealth. The Carbon tax is a minor example of this. A lot of nations and groups of people already talk this way. They may even think this way too. All of these would lead to stagnation. The wealthy would like it because it wouldn't allow anyone to pull themselves up to their level or to replace them. For the wealthy this is ideal since the poor people will work very hard to keep everyone else poor. It would be like having a bucket of crabs. If you have multiple crabs in a bucket none of them will be able to escape since the other crabs will pull them back in once they start to climb up and out. [Answer] A massive EMP (perhaps from a supernova) fries all electronics (except some deep buried military hardware, some mines perhaps). No computers, no pre circa 1970s cars working, no working electronic locks et.c. With the entire IT sector erased and all the electronic records gone the economy collapses into a bartering economy. In hospitals all advanced machines stop working. No patient records, no possibility to make anything but the most basic medicine as the pharmaceutical factories are also computer controlled. Accept for some old phone lines and older radios communication is back to snail mail. [Answer] While not as elaborate as some of the others, How about something on the order of the Havenites from David Weber's Honorverse. Specifically their Basic Living Stipend... > > In 1700 PD, the Republic was renamed the "People's Republic of Haven" and used a kind of deceit that transformed the poor sections of society into a welfare state, in which citizens were entitled to a specified standard of living adjusted for inflation known as a Basic Living Stipend. The new head of state became the Hereditary President. A new breed of machine politicians, called Dolist Managers, emerged as kingmakers, being able to deliver the votes of millions of so-called "Dolists" to the candidates (called Legislaturists) of their choosing. Some years later, the deteriorating financial and economic condition of the Republic led to the DuQuesne Plan which expected to use conquest to make up the shortfall. The original Havenite democracy disappeared, and power came to be concentrated within the Legislaturalist families, who established a number of secret police organizations to maintain control over the renamed People's Republic of Haven. The original Havenite Constitution was replaced by a new document which enshrined >Legislaturalist rule. This constitution was the first step of the so-called "DuQuesne Plan", named after the Havenite politician who proposed it. (HH1) > > > In 1804 PD, the treasury was effectively empty . (HH4) > Source:<http://honorverse.wikia.com/wiki/Republic_of_Haven> > > > Now, this also translated into schooling -- only, certain pre-approved texts being taught, with limited support for innovations. Additionally, add in the fact that it devolved into something like the French Revolution. To translate Fiction into psudo-fact,some industrialized country with a large welfare state embarks on a plan similar to the Basic Living Stipend -- granting recipients a guaranteed income. Even though some politicians see the handwriting on the wall, this movement gets entrenched to the point that "The sky is falling" realists get voted out -- and, everybody if they realize it, tends to push it onto the next generation (e.g. it's not going to happen to us...its a future problem). As this is occurring, there's no incentive to work or study -- why, we're getting our Basic Living Stipend...we don't need to expend extra effort in those areas. Now, some brilliant mind, figures on the "DuQuesne Plan" -- invade/raid nearby solvent countries and run roughshod over their finances and use that to prop up our pyramid scheme of a government. Now, if said government had access to modern weapons and a willingness to use them, this might pose an issue with 'removing' them. Plus, modern warfare could create economic, sociological, and economic catastrophes. True, this might not cause immediate anarchy, but at least it is a 'possibility'... [Answer] **Islamic Nuclear Terrorism** Well, any nuclear terrorism on a decent scale would do, but currently elements of Islam seem the most motivated. They smuggle nukes into New York, Los Angeles, D.C., London, Paris, Berlin, Moscow, San Francisco, and Beijing, then set them off within minutes of each other. It kills a lot of people, of course, but, more than that, first world economies are destroyed across the Earth. That cell phone you just bought? It probably depends on a lot of parts made in a lot of places. So do the trucks, ships, and planes that transport those parts. Or parts for power plants. Or food. Now some of those suppliers are gone -- dead. And even for those still alive, nobody knows who owes how much money to whom, because bank records have been destroyed. So how much money do you really have, if you can't show how much you had? Money suddenly means less. Without a basis for trade, the world-wide economy grinds to a halt. Eventually, starvation starts in a big way. We still have plenty of farmland, but money's lost some of its shine, and you can't really feed a world with barter. And some of the technology used to run farms is dead. And some of the plants have been genetically engineered not to be able to provide the seed for next year's crop... Oh, plenty of people in the farming areas survive -- and a lot more than today do it as farmers, rather than financiers or engineers or programmers or artists. [Answer] The Dark Ages are called that because there was poor record keeping, or at least very little record keeping which survived to modern times, so we don't know what was going on in a lot of places for quite a long time. It doesn't necessarily mean that society was very primitive, although the two things will tend to go hand in hand. It's hard to imagine there being another Dark Age like this: our society might collapse, most people might die, and we might revert to feudalism etc. But i think we'll always record stuff, in a way that future generations could read. [Answer] Humanity has collapsed before and will (unfortunately) collapse again. The symptoms before each collapse are: ignorance, superstition, religious fundamentalism, xenophobia, intolerance, and rejection of science. See the following chart which was lifted from Marc Widdowson's lost web site. <http://www3.sympatico.ca/n.rieck/docs/dark_age.html> [](https://i.stack.imgur.com/DE8nK.jpg) [Answer] A "dark age" really means an age that is technologically, culturally, civilly, and otherwise underdeveloped relative to what came before it. The destruction of the totality of the knowledge of mankind will do the trick for this. No libraries = no knowledge of the previous scientific accomplishments = no ability to implement new technology. When all the nuclear engineers die, nuclear power ceases to be feasible. [Answer] I have an idea for causing a dark age, both literally and figuratively, but it might take a while, like 10 billion years. For all the accomplishments of humans in your setting, FTL, effective or otherwise, is still not possible, so humans are more or less just stuck in the Sol system. The dark age comes when the sun expends and then completely dims out, causing a massive drop in power output, as I'd imagine a futuristic human race with no access to extra-solar materials would rely on the sun for 80+% of its energy needs. As the sun dims down, power levels dip down across society, and in such an advanced society, it is sure that their power demands will be many times our current power demands, and so when the power supply goes down, their standard of living, as well as the ability to do good science will diminish greatly. This is of course assuming, your humans have the ability to survive the sun-expansion phase of the sun dying [Answer] In order to get to a dark age, were technology is virtually non-existent, and society essentially flat lines with worldwide GDP would be almost impossible coming from the context of today. My thinking is that any doomsday event that would wipe out 80-90% of the population would leave the survivors in a decent position to prosper. Resources would be relatively abundant, and knowledge of technology would also be intact. While most people would be concerned with survival, IE growing food to eat, the technology of food production would not of been forgotten and people would be moving out of food production and into other pursuits rather quickly. The dark ages would be a matter of some years or decades, but would not likely be long enough to effect anyone but the original survivors. Not long enough to be an age. The series of events that would bring about a dark ages would have to be a catastrophe of such magnitude that society becomes disjointed enough that groups of survivors are not able to regroup for generations. The knowledge of technology of the current age would have to devolve into myth in the minds of the decedents of the survivors in order for a dark age to be. In other words the history of the world would have to be effectively wiped out for a dark age to happen. I like the peak oil to start the disaster but not particularly to wipe out society enough to go into a dark age. Oil runs out, wars start, the planet depopulates until a point that everyone surviving has enough to eat. One billion people say, or even a few hundred million only. The technology would still be relatively intact and the remaining population would be able to get it back together enough were a long dark age does not seem likely. Add pandemic to that that wipes out 80-90% of survivors, then you have conditions for a very long dark age. A few tens of millions of people at most in isolated pockets, where technology is lost, central authority is lost and you have a dark age that could be resilient for a few centuries. [Answer] **Perpetual Nuclear Wars** But not the way you think. Forget the [Fallout](https://en.wikipedia.org/wiki/Fallout_(series)) post-apocalyptic romance, the nightmarish picture of a nuclear winter may very well be [just a scary story forced upon us](https://en.wikipedia.org/wiki/Nuclear_winter#Criticism_and_debate) by a bunch of people who used their authority to discourage the leaders from using nukes. After all [we've conducted more than two thousands of nuclear explosions](https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests) and the world keeps spinning on without giant two headed frogs eating cancerous children [in Nevada's swamps](https://en.wikipedia.org/wiki/Nevada_Test_Site). No, the truth is far less nightmarish, but far more scarier because of how realistic it is: It's 2014-2026, proxy wars are back and bloodier than ever so USA and Russia go to war(or rather a small clash of interests) with each other over a dispute somewhere in Easter Europe or Middle East. Things go sour and tactical nukes hit the floor. The World takes a break for a month of heated debates whether they should stop it right here right now, however UN Security Council is such a joke by now that it fails one last time as hipocrisy and warmongering take the better of world leaders and the war escalates. After a year of full scale conflicts raging on mostly conventionally with some tactical nuking sprinkled over the most heated areas, one of the sides starts to lose the war(most likely Russia) and has to either accept the defeat and eternal blame or go strategical. Shit hits the fan, nukes fly across the ocean, military bases and industrial centers are ruined. But that's it. Most of the civillian populations survive since [it's not the real goal of a nuclear war to destroy enemy civillization](https://en.wikipedia.org/wiki/Nuclear_strategy). Both NATO and Russia/China are in ruins in terms of industrial capacities and economic stability following nuclear exchange, their populations are discontent with the former governments to the point of collapsing into a confederations of smaller independent states that represent little to no authority on the world arena. The rest of the world is pretty unscathed except for the fact that the international trade is screwed over with the currency crisis and informational infrastructure collapsing for a time being. Slowly(several years?) the world goes back to what it was before. Only problem is that it wasn't the best of places right before WW3 broke out and bad lessons were learnt out of it: * turns out nukes don't represent global threat after all - it's safe to bomb your opponent. * intergovernmental organization formed in place of UN is a faint shadow of what LoN and UN used to be without strong states to back it up sicne there're no victors. * blatant lies and hipocrisy combined with overwhelming impudence backed by military might make right. * the bright minds that used to work on the solution for global problems leak to the now[First World countries](https://en.wikipedia.org/wiki/Developing_country), however they're tasked with the development of less noble tech: Nuclear weapons, ICBMs and Military satelites. This is a very nasty combo that perpetuates itself: * Everyone is for himself since there's no international trade * There's noone to oversee the nuclear weapon proliferation * There's no authority to stop the kids from misbehaving Security alliances akin NATO/Warsaw Pact are formed but there's nothing stopping them from going to war with each other over silly disputes. Eventually shit hits the fan again and nukes go tactical and then strategical. The title of First World countries shifts again to [other states](https://en.wikipedia.org/wiki/Third_World) and the cycle repeats itself howmany times you want. Humanity enters the 22nd century with 11 billion pops as predicted and global warming causing the desertification of most arrable lands to fee.. star.. motivate them. AK-47 and Toyota Hilux are the pinacle of human engineering thought while nuclear weapons finnaly become Lost tech with no industrial or scientific background to be built upon. And yes hungry migrating tribes of Slavs invade Switzerland somewhere around 2089-2091 to fulfill your last requirement inspired by the myths of a land of plenty that no war has ever touched. [Answer] **All states are failing** A viable way to enter a persistent global dark age is to let all states, and therefore all economies fail. This is my second answer on this site based on the book [Why Nations Fail](https://en.wikipedia.org/wiki/Why_Nations_Fail). So, image the world economy contiues its path on political and economic extraction, i.e. political power and economic opportunities are controlled by an elite minority. For this to lead to a dark age, all inclusive nations, especially the developed ones, need to fail. This, however, might be plausibly possible if several trends are allowed to grow unchecked: * Unfair global trade, which impoverishes poor countries for the gain of the rich ones. This will make the world economy very vulnerable, if something was to happen to the few rich countries. * Big money corrupts democracies, elections gradually evolve into a monetary war of attrition between the major political groups, making democratic regimes less and less inclusive and democratically functioning. * Big money corrupts judicial systems, when the rich can buy their way out of jail, then democracies are further weakened and a path to absolutism becomes more likely. Think of the world financial crisis which started in 2007/2008, there was a lot of criminal activity involved in the build-up, yet little to no-one was put in jail. * Autokratic and absolutist regimes become more and more isolationist to consolidate their own power, as in better to rule over beggars than to loose power. There are plenty examples of this happening in world history * Developed countries become economically more and more interdependent. The global economy becomes more and more monopolized. If the global economy depends on a small number of very centralized hubs, taking out some of these hubs may have large implications, think of the oil price shocks, or the more recent [hard disk shortage](https://www.theguardian.com/technology/2011/oct/25/thailand-floods-hard-drive-shortage). * Let the world economy become less and less diverse, in terms of companies/competitors. If a sector is dominated by a monopoly, then that whole sector dies, if the monopolist was to vansish. * Let the world economy become less and less diverse, in terms of technologies. Again, with the dominance of big monopolists providing everything you need, there is little incentive for people to come up with their own solutions. However, if something was to happen to the monopolist, all is gone. * Enter the political strongman, an economy under an autocratic regime may be ordered to grow, however, sustainable growth seldomly can be decreed, think of the [Great Leap Forward](https://en.wikipedia.org/wiki/Great_Leap_Forward) Over time, in this scenario, the world economy becomes more and more extractive. The rich elite extracts wealth from the poor, and this elite becomes smaller and smaller over time. The elite itself becomes unstable as there is astronomical wealth to gain from being this very elite. So infighting within the elite sets in over the political and economical control. If all high-tech is bundled in the few countries of the rich elite, then all high-tech goes away as soon as the rich countries tear themselves apart in internal or external wars. With a very high degree of centralization, the global economy becomes very vulnerable to crises. --- **tldr;** Apply how colonialism impoverished, and still impoverishes, large parts of Africa and Asia to the whole world; with ruthless, monopolistic, unchecked capitalism taking the part of colonialism. Add time, and the world economy is screwed. ]

[Question] [ The security of public key cryptography relies on computers not being able to generate anywhere near 2256 guesses per any reasonable time length. The obvious implications of a computer this powerful would be that Bitcoin and all other cryptocurrencies would be hacked immediately. But what other less obvious destruction could a computer with this capability provide? What would immediately tumble if the power of this computer were directed at it? [Answer] The destructive power of this device would be immense. If you defeated the safeguards on it, it would become the single most powerful bomb ever envisioned. Doing irreversible calculations, as described here, takes energy. It turns out there's a [bare-bones minimum amount of energy](https://en.wikipedia.org/wiki/Landauer%27s_principle) required to set 1 bit, based on the entropic content of that data and the temperature. A computer doing irreversible operations will naturally warm up to the temperature of its heatsink, and the coldest heat sink we can get is 3K, the temperature of the background radiation of the universe. You can try to cool it lower than that, but you end up burning more energy than you save. As a result, there's a minimum of $2.87 \times 10^{-23}$ J/bit of energy wasted every time we flip a bit in an irreversible computer. If we had a reversible computer, this limit would not apply, but in the case of reversible computing, number of calculations is not the unit of measure, so they would not apply to your question. It turns out that just to run a counter from 0 to $2^{256}$ takes a lot of energy.\* A **lot** of energy. In fact, using that bare bones minimum energy per bit-flip, it will consume 3/4 of the energy in the known galaxy. That's just to run the counter, not even doing any calculations. So, given a device with 3/4 of the energy of a galaxy, I think we'd want to respect its integrity. The destructive power of this computer would be unimaginable if it were simply disassembled and turned back into usable energy. \* *As pointed out in the comments, counting like this is a reversible operation. In this case, I am assuming the counter is implemented using irreversible logic like those we find in a modern ALU. This counter is my surrogate for the general purpose calculations that we could have been doing, such as calculating SHA-1 checksums. This operation is within a factor of a thousand of the most trivial irreversible operation possible (erasure of an unknown bit)* [Answer] As far as decryption is concerned: The encryption systems currently in use are using key sizes that make it absolutely impossible to crack them using known technology. These key sizes would be cracked if you had 2^256 operations per second available. So what would you do? Increase the key size. RSA with 1024 bit keys is close to uncrackable today. Not completely out there, but very hard. RSA with 4096 bit keys would be uncrackable by the alien computer. It would be a bit harder to use with our native hardware, but not that hard. The same with symmetric keys; you would have to rearrange your algorithms a bit, but use a 512 bit key where today 256 bits are considered total overkill, and you are fine. [Answer] It would make most of our current encryption systems obsolete. However, it would also make new systems possible. These new systems will be unbreakable until the next set of aliens arrive. Net result: Many old secrets will be revealed. But new secrets would still be secret. There will be a transition period before we adjust. History shows us that criminals adjust faster than business and law enforcement. That could be chaotic, for a while. But then things will settle down. Passwords will become a thing of the past. Any password a human can remember, these computers can break. I think biometric recognition would have to replace it. Today that doesn't work too well, but with better computers we can do a better job of it. You might have to both look into a camera and speak into a microphone to identify yourself. Maybe other sensors can be used too, like smell sensors, signature recognition (with writing speed and pen pressure added to the data) With enough computing power, the possibilities are endless. However, one thing is certain. Computer programs will be written that are complex enough that even these computers will seem slow to their users. [Answer] **I not sure we would even understand the limits on what this computer could do.** However, I know one thing, it would not be able to do quickly, simulate a monkey typing out a copy of Shakespeare's Hamlet by random typing. As remarked in [Wikipedia](https://en.wikipedia.org/wiki/Infinite_monkey_theorem) > > However, for physically meaningful numbers of monkeys typing for > physically meaningful lengths of time the results are reversed. If > there were as many monkeys as there are atoms in the observable > universe typing extremely fast for trillions of times the life of the > universe, the probability of the monkeys replicating even a single > page of Shakespeare is unfathomably minute, > > > People rarely have an intuitive understanding of the difference between really big numbers and the infinite. 2256 is a really big number (OK, not so much when compared to say [Graham's Number](https://en.wikipedia.org/wiki/Graham%27s_number)). But infinity is completely different. --- The reason for the comparison to the infinite is that this example is often phrased in terms of an infinite number of monkeys. With infinite monkeys you get Hamlet, Mabeth, etc. including translations into every language, as well as else everything else that can be typed in the time it take to type it in without without mistakes. Really big as in 26^130000 for Shakespeare is so far beyond 2^256 that the computer will not dent the problem before the heat death of the universe. There are many computer algorithms that act more like the Shakespeare problem in terms of needed computation time that you might expect intuitively. Just because an algorithm is known, does not always make the problem solvable. [Answer] Most of the existing answers are completely ignoring physics. Assuming you want to compute anything, you need data, and the [Bekenstein bound](https://en.wikipedia.org/wiki/Bekenstein_bound) puts a lower bound on the physical size of the device that has any hope of representing a given amount of data. Combined with whatever size you get, the speed of light then gives an upper bound on propagation of data within the system. 2256 is such a huge number that even if your data size were just a few bits, you could not reach anywhere near that computation speed. So your computer simply does not exist. [Answer] New physics. Attempting a 2^256 calculation with terrestrial timescales and energies is utterly impossible. Cort Ammon's answer is spot on with what happens attempting it given trying to build the computer with current physical understanding. Whatever befalls in the finding of such a computer to our current internet is nothing compared to the power that would be unlocked by dissecting it to learn the new physics and rip the secret out of it. I see no non-magical cases where a contained computer such as can be delivered to the earth that can do this does not unlock for us one of warp drive or time travel. [Answer] Practically: It would make any sort of super computer superfluous and it would break all and every encryption currently employed. It would NOT allow password guessing or breaking into a remote computer (not a mathematical problem - you can block access after x attempts and there is no way around this) but forget any sort of digital signature. Forget HTTPS. [Answer] It would mean that WPA2 wouldn't be safe anymore. Keys could be bruteforced in no time. Router manufacturers would be required to develop and deploy new, secure WiFi encryption schemes into their new models, and until their wide adoption (could take years), everyone and their dog would use their neighbours WiFi. [Answer] This would allow the aliens to simulate other possible Worlds, simulate life appearing, intelligent life forms appearing, and eventually a civilization appearing. They can then build a real world copy of that civilization for their own use. A potential problem for us is then that the outcome of such a simulation might be that they happen to generate our civilization by chance. If they happen to generate a virtual copy of you and decide to copy you as well, you may wake up in an alien World instead of your own bed. [Answer] Assuming the physics actually worked(see Cort Ammon answer about the amount of energy) Nearly every single mathematical problem would be able to be solved by brute force. And for the ones that don't the numbers would get extremely high very quickly. Chess for instance only has 2^155 positions. So it could evaluate a board to the finish faster then you could decide a move. [Answer] In terms of cryptography it would indeed mean the end to all current forms of crypto and the mechanisms which rely on them (I've seen RSA, WPA2 and others mentioned in the other answers here but really all of our current algorithms rely on the same fundamental theory). However, we are already looking at post-quantum cryptography and designing theoretical algorithms to be 'quantum-hard', in anticipation of our research into quantum computers turning up serious results in the foreseeable future. A quantum computer would have a similar effect to one capable of vast numbers of computations as by nature it is able to check every value simultaneously (in theory - I believe the prototypes have to limit the range of possible states but the idea holds). It is believed to be possible to create an algorithm which doesn't rely on a computationally expensive problem (in current crypto, this being the basic mathematical problem of the generation of large primes). I'm no mathematician but my field is IT security. If you're interested in how we might alter our systems to deal with an issue like this then check out the New Hope algorithm. [You can find a paper about it here](https://eprint.iacr.org/2015/1092.pdf) [Answer] ## Connectapocalypse we could now create server to host mind diving and connect the whole human race to it via their spinal cord (sound familiar?) ## unlock human potential that many calculations per second would only be beneficial on running multiple calculation at once like the brain. it could help us understand the brain if at least not emulate the brain. ## Fast Unencryption through brute force There are supposedly many black sites out there that have the encrypted form of passwords that were obtained through scrupulous means and having this machine would allow these black sites to get a likely password more re-actively instead of brute force attempting the password for months at a time. usually its quicker to run a few computed guesses based on other information such as the location the data was obtained from, when information was obtained, how much information there is etc.. [Answer] Unfortunately 2^256 is a very big number; for all practical purposes it's close to infinite. Remember that 1 googol, 10^100, is literally more than everything, for example more than all photons and atoms in the observable universe. 2^256, or roughly 1e77, is almost nothing compared to a googol, but still close enough to be over the top. It is for example more than the number of atoms in the galaxy (perhaps 4e11 stars \* 1e57 atoms/star). This makes the question less interesting than, say, 2^100 flops. But ok, let's suppose that we have essentially unlimited computing power, adequate storage with it and that it is 100% reliable: Update: The first thing to note would be that it's likely that this computer would be a post-singularity super intelligence of its own. It will not only be alive but it will be the equivalent of a god to us; all speculation about it is futile because its ways will be unfathomable. Still, in human terms it'd be an interesting question what its motivation would be to talk to us or even help us, and in which ways it would choose to help us. These are similar questions as people around the world ask about their respective gods. I'm tempted to say that this machine is — next to the spaghetti monster — a candidate for the god of the SE crowd (except perhaps the Judaism SE), in as far as it is a surface for the projection of our speculations and hopes of redemption. (This paragraph was inspired by my Marvin quote in the comments section.) The rest of the discussion is based on the however incongruent assumption that the computer will behave like a contemporary computer, just faster. Not only cryptography but *all* computationally intensive tasks would be almost infinitely accelerated, if the device is (remotely) accessible to the general public. * Essentially all cloud storage will be transferred to this machine. The only reason to have local or regional computers is speed of access: akamai won't go out of business. * All simulations which today are performed on supercomputers or expensive work station clusters will be performed on it. The interesting thing is that with better simulations less true insight is necessary (take chess as an example). + Weather: One can simply brute-force simulate the whole atmosphere, by the molecule. Don't get me wrong -- weather is a chaotic system and simply is not deterministic. But forecasts will improve dramatically. I suppose that the computational complexity of weather forecasts is exponential; every doubling of the computing power may buy the forecasters perhaps 6 hours more prediction time. But we probably talk 20 or 40 or 80 doublings, depending on how much of the computing power we want to devote to weather forecasts. + Brain: A human brain apparently has < 10e11 neurons. We could not only brute-force simulate *a* brain but *all* brains. (I'm not sure whether we'll have consciousness; that may need some qualitative insights. But the progress will be immense.) + Physics: One could, for example, simply brute-force simulate a whole star; the sun has apparently only 1e57 atoms in it. Which gives you an idea of the size of the machine, by the way, if it has storage to match its computational power and each bit is an atom: as big as 1e20 suns, or 1e9 galaxies.It is clear that the machine's capacity is sufficient to simulate *all of the physical reality in our galaxy* to a degree of precision (the atomic level) which will make it very close to the actual thing. My guess is that we would start uploading simulations of ourselves fairly soon (some decades or at most a couple hundred years). Elon Musk's simulacrum would run around in it and speculate about being in a simulation.-- That we'll be immediately able to have CGI look like real life is just a foot note; but one which will change the entertainment business and may have implications in the court room because true evidence could not be told from falsifications. [Answer] Nothing will really happen. Most secure system have a 2 party login, your bank have a token, where you need the token and the password to get in. Every time the token changes so you have to make the right guess at the first try. Lets say you could make a qualified guess with the right algorithm, you still would only have a limited amount of attempts before the account is closed down, because the intrusion counter measures kicks in. Then the next step would be to try and kick in the door. Well, unless you are able to pick out the data and move it physically to your device, then the bandwidth of the unit stored on it (High end PCI harddrive makes about 250.000 operations per second) would make it a major slow down. Doing this over the internet would be even worse, asuming you had the bandwidth you would just make one HUGE DDOS attack on the world. My conclusion is: Unless you have the data directly on your device (and it could take months to transfer, [because of this google even fedexed nasas website to them self](http://royal.pingdom.com/2007/04/11/fedex-still-faster-than-the-internet/)), it would be useless, and if you have access to the raw data, well you don't need a fast computer to break in to it. It would be like have a F1 car on the Faroe Islands. (More about fast cracking computers and its problems [here](http://arstechnica.com/security/2012/12/25-gpu-cluster-cracks-every-standard-windows-password-in-6-hours/)) [Answer] It would be the end of RSA. Some evil genius would make a boatload of money and we go back to the age of trading goods in stead of electronic currency. [Answer] For, this answer, I am assuming the aliens tech make us look like cavemen and discussion of laws of physics are all moot because we don't understand anything. If the computer was practical (similar to a regular PC), not the size of a galaxy, nor using a solar system worth of energy to power it. If we could duplicate it, we could make it bigger better stronger, and defeat most encryption for a long time. If it were general purpose enough like a PC, it would end all illness as the human genome would be fully sequenced instantly. All drugs would run all permutation basically instantly, and instead of trial and error we would just brute force every molecule combination against every genome of every illness. If you could keep it a secret, you could get a large set of all the secrets and use them for good or evil. Blackmail people into whatever you want, or your secrets will be revealed. As soon as people knew, all encryption would be increased by orders of magnitude nullifying your advantage. 512 bits = 2^256 seconds to crack, not in many lifetimes. 256 bits to 1024 or 2048 or whatever. 4096 bits encryption to maybe 65536 bit encryption, and it is impossible to crack again. It will take several weeks for critical systems to be updated, but after that your device is worthless for this purpose. Login to all vulnerable systems would probably just be disabled until the new bits lengths were deployed. There are devices that won't be updated, and you can get their data until people buy version 2 of the product that is no longer vulnerable. The additional bits will slow things down for awhile, but the hardware will catch up and everything will be fine. If the device is like one of our ASIC dedicated to only brute forcing passwords, it will quickly become useless, and all system are updated to longer more complex encryption. [Answer] Late to the party here. But a lot of people talked about the physics challenges of a computer like this. People have already brought up that you would need antigravity to prevent the energy contained from destroying the planet, and that you would need a very good system for dealing with excess heat. I'd also like to explore for a moment the spatial requirements of a computer that can do 2^256 operations per second. To my knowledge, the current most powerful supercomputer is Sunway TaihuLight, which can hit speeds around 100 PFLOPS (about 2^53 operations a second). That is probably a decent order-of-magnitude estimate for the maximum density of FLOPS that can be achieved by transistor-based computing. For anything resembling transistor-based computation, a computer capable of 2^256 operations per second would be **a lot** bigger than the planet. Even if you just gave humans a client to this massive computer and kept the actual computer somewhere up in space... Such a large computer would be unable to function. Because it would be so big that to send data from one part of the computer to another in a timely fashion, you'd need to send signals at speeds faster than the speed of light. And you could only get the computer back to a manageable size by making something 2^203 times more compact than a transistor. For reference, a quark is only somewhere in the ballpark of 2^32 times smaller than a transistor. Probably the only way to get around this to use more than 3 dimensions of space to build your computer. That allows all of the bits to be closer together, so that data transfer is no longer impossible. In N dimensions, for a computer made of transistors that are close enough to reasonably communicate data, we can estimate that it's computing power would be very roughly (2^(cuberoot(53)))^N operations per second. If we want that number to equal 2^256, N=14.4633, but since you can't exactly have a fraction of a dimension, we round up to 15. So basically, you would want about 15 spatial dimensions to house a computer capable of 2^256 operations per second. I figure it is probably hard to put an upper limit on the capabities of any technology that can leverage 15 spatial dimensions. [Answer] Brute force any tech. Want some nanotech? just tell this computer to simulate possibilities using an evolutionary algorithm ( + quantum theory) until perfect nanobots are developed. The computer could design almost any tech that fitted our understanding of physics in an instant. ]

[Question] [ Set in the not so distant future, we find a habitable planet very much like our own. The only downside is that it's around 500 years of travel with our current technological capabilities. We have to assume a few things in this hypothetical scenario: * We have the means to send around 500 humans to the planet. * All humans survive the journey (Think cryogenic sleep). * Only a single ship can be sent out. All the necessary people and materials should be on this ship. The colony will not be able to be supplied with additional colonists or materials. * Communication with home is **not** possible. What are the top priorities after landing in order to create a self sustaining colony? [Answer] Firstly, if you don't have the capabilities to construct a closed life support system, then you have no business trying to construct a colony many light years away, with no support and no backup and no actual certainty that the world is safe or habitable ahead of time. Your colony ship either needs to be a habitat suitable for a decent number of people to live in for extended periods of time (decades) or it needs to be convertible into such a thing without the need for large amounts of resources from the target system. This means that when you arrive, you *already* have the issues of food, water, air, power and shelter taken care of, because you have brought them with you. If you can't bring them with you, *don't go*. Just chuck yourself off a bridge instead of engaging in a multi-trillion-dollar, multi-century suicide. You can supplement your stocks of useful minerals, metals and water when you arrive by sending out robot probes and tugs to harvest useful asteroids or comets, but the initial intent should be that the colony *ship* is self supporting, even if this means keeping a portion of the colonists in suspension whilst stocks are built up and safe habitation areas are constructed. > > what are the top priorities after landing in order to create a self sustaining colony? > > > The top priority is *not landing*, strangely enough. Park your colony ship in orbit around the target world, and then start getting your house in order. Thoroughly survey the surface from orbit. Observe the weather. Send out probes to other nearby places of interest, *especially* closer to the new sun (because you want as much warning as possible of solar flares, after all). Fly more probes through the atmosphere. See what sort of stuff in floating around in it, and exactly what its composition is. Land things on the surface. Look around. Sample the local wildlife and vegetation and microorganisms. Fly some of it back up into orbit, where you've been building a secure biohazard lab to study it. You can, and indeed should spend years testing the planetary environment and its inhabitants (if any) to ensure that you're not all going to go down there, take a breath and immediately drop dead (or worse, wait twenty years and *then* drop dead). Growing a population of lab animals from suitable strains brought from Earth will be a priority here... if mice and bunnies can't survive down there, that's a bit of a red flag. Pathological organisms or chemicals in the environment will need to be identified, if they exist, and no-one can actually get down to the business of colonising the new world until steps have been taken to treat or provide immunity to these pathogens. Moving people to the planet below will be a one-way trip, at least to start with, because you can't risk contaminating the colony ship. Quite when things should be declared safe is anyone's guess. When the colonists have healthy grand children is a reasonably conservative estimate. The truly paranoid might say "never", and they'd be welcome to set up a separate habitat in space or on one of the other worlds in the target system and keep themselves and their descendants quarantines.‎‎‎‎‎‎‎‎‎ [Answer] I think that the number one priority is actually going to be confirming that the planet is, in fact, as habitable as previously anticipated. Previous information on the planet took 500 years to get here; we don't know how fast we were traveling, but I assume it was a relativistic speed (IE a significant percentage of the speed of light). As such, all data determined from afar is based on how the planet was somewhere between 500 and 1000 years ago-- that's a long time! Lots of stuff can change in that time period-- look at what we managed to do to the Earth! Look at major extinction events, such as the asteroid that took out the dinosaurs! The planet could be experiencing an ice age, increased seismic activity, the advent of new life, an industrial revolution for the life that was native to the planet, flooding as its ice caps melt-- lots of stuff. If the planet is no longer suitable for colonization, it will be important for the colonists to re-evaluate and determine what their next course of action will be. It will also be important for them to observe planetary conditions in order to plan for how they'll proceed once they land. If it's 75 F, sunny, a perfectly breathable atmosphere with tons of fresh water available, first priority will be very different than if it's -17 F during the night and 108F during the day, with the only source of water being heavily salted, for example. Assuming that all of *that* goes well, it will be important to follow that up by confirming that the atmosphere really and truly is breathable. If it isn't, the next step is figuring out what sort of chemical reactions that crew will need to run to scrub the air or separate oxygen from it. Earth-like could have a lot of different implications, after all. Next, as everyone has said, is the food and water supply, with water being the most critical. Humans are designed to run without food for a bit if we can't get it. We might not like it, but we'll last longer without food than without water. Sources of water might include polar ice caps, ground wells, oceans, condensing it out of the air itself, or making it chemically if enough free-floating hydrogen and oxygen (or combustible hydrocarbons and carbon-oxygen chains) can be found. Shelter is probably alongside water in terms of importance. What is the climate of this world? If it gets exceptionally hot or cold, shelter could mean the difference between power supplies lasting a day and lasting weeks potentially. Prior to descending to the surface of the planet, I would think that the ship would include some sort of Geo-stationary weather satellite to deploy. This could give colonists an alert whenever there was some sort of inbound danger, such as an impending storm like a hurricane, or perhaps even migration patterns of any sort of dangerous local wildlife. It would also be useful for imaging different sections of the planet in order to determine where to expand to in later months/years as the colony finds the need to grow. [Answer] Good answers from a lot of people, but I can see one flaw: The premise that only one ship will be sent. What civilization will only send one ship on a one-way 500-year journey? Surely in 500 years other ships would also be sent to the same destination. Some of these might well be faster and could therefore arrive before the original vessel even gets there. Your colonists might arrive and find a 300-year old colony already established. In this scenario, the #1 priority would be to establish contact with the colony, introduce yourselves and catch up on the news & 500 years of history from home. [Answer] I believe the top priorities, in order, will be: 1. **Food and water.** Once stored victuals run out, there will have to be local sources for food and water. Food might be adapted from local lifeforms, or the colonists can begin growing crops from seeds, etc., brought from home. 2. **Shelter.** Shelter from wind, rain, and cold will be the second priority, once the future food supply is secured. Until then, the colonists can rough it, sleeping in the open under water-tight thermo blankets or in the landers. 3. **Energy.** Modern technology needs an energy source. Initially, solar panels or a microfusion reactor brought from home can supply energy for the most urgent needs, but eventually, the ability to grow the energy supply as needed will be essential. 4. **Transport.** The means to travel and to transport goods beyond what you can carry walking will be important once mere survival is secured. Vechicles, whether ground, air, or water, can be used for exploration and to bring resources into the colony. 5. **Infrastructure.** Eventually, as the colony expands, infrastructure will be needed: Plumbing, electrical wiring, roads, communication, irrigation, etc. [Answer] The top priority will be fertility. They will need 3-5 children per couple, perhaps more if the planet is dangerous (native life, environment, whatever). With only 500 people, that's not nearly enough to bring along all the specialties required for a modern civilization... Charles Stross has speculated on his blog that that's north of 100,000 distinct, highly-trained fields (even medicine along probably has more than 500). Since you'd need to train these children and you can't bring along the people to train them (or even Skype back to them on Earth), they will be trained in virtual reality by software (perhaps AI, perhaps not). You'll still need several generations of high fertility, so figuring out the specifics of why fertility tends to drop among highly-educated people will be important. This is a rather large sociological/economics problem. If fertility dips below replacement level the colony is really dead on arrival. [Answer] Without communication back it's just simple stranded island scenario. 1: Steady water supply 2: Steady food supply 3: Shelter (Assuming your ships won't be available as long term housing) 4: Elimination/Subjugation of local hostiles. (This can be anything from animals to humanoids) But seeing it is long term and 500 people isn't extremely much you will have to enforce a form of paring system to go against inbreeding. (Because of those 500 people i assume that at least half are already done with having kids or are unable to by genetic defect or age) Also this is with the assumption you have a clear chain of command. [Answer] The top priority would be determining if life is present. If life is not present or at least not extensive, but the planet is habitable then they can land and set up home. The top priority would be shelter, but I assume they would have some form of basic shelter with them so the next priority would be food and water production. If the planet is home to life then they will have to be very careful at least initially. An alien biogenesis would probably lead to a very different kind of biochemistry. It might not be based on DNA it might be based on some other molecule and evolved very differently. The enormity of all the chemicals involved in maintaining life is huge and an alien biochemistry would include many compounds which were toxic in the same way that some randomly synthesised organic chemicals might be toxic. Sealed suits might be required to prevent the inhalation of microscopic alien life producing any number of alien biochemical compounds. [Answer] **How good are their robots? 500 people can’t sustain a modern technological base.** Without robots you are doomed to a pre-industrial civilization. Therefore your first priority will be to get robot production up and running while keeping most of your population in cryogenic sleep. Once you can manufacture robots, you can manufacture everything else: Greenhouses, habitats, water and gas purification etc. etc. [Answer] # Don’t Land The only ways that only way it is remotely plausible that a colony ship could travel in space for 500 years and still be intact are either: A) You have Star Trek esque matter replicators on board, on which case you have absolutely no reason to go down to a planet (or to worry about resources once you get there), or B) You have a colony ship so ludicrously vast that it contains chip manufacture facilities, foundries, colossal power plants, uncountable tons of raw materials, even more uncountable tons of fuel, thousands of robot servitors that maintain it all... there is no conceivable way to land it, and no real reason to. Any planet you find will mostly be a source of raw materials and maybe an agricultural base. Your order of operations will be to build a space elevator, and then build ever-expanding resource extraction facilities in a spiderweb around it. [Answer] Researchers would first have to send probes to the planet to determine the likelihood of ELE (Extinction Level Event). You can ship 500 people to a planet, but if they don't predict a massive electrical storm coming along, or fire rain or whatever, the entire population could get wiped. Others have mentioned food, water, etc.. pathogens would be a major consideration, too. The colonists would need to either orbit the planet for a long time to sample the air for potential pathogens and run experiments, or to establish a research base on the ground that isolated them from the environment until they could make sure no existing pathogens exist that would wipe the entire colony. This is the "why are you taking off your helmet even though the atmosphere is breathable, you f'ing idiot!?" factor. Chances are a bit slim for this to happen though, contrary to popular belief. A planet already has an establish ecosystem full of predators, prey, specialized creatures fitting in niche areas. Humans showing up wouldn't likely match any pathogen or bacteria or what-not that currently exists....but, since bacteria and viruses reproduce so rapidly, they could suddenly jump species and start wiping out humans. EG: there could be a creature or plant that has a pathogen in it that has reached an equilibrium in the enviromnet. Humans show up as an invasive species, and provide a new host to take advantage of. The humans might have an immune system that can adapt to it quickly, or it could be somethign that wipes them out quickly. Generally speaking, the bigger concern would be the humans act like an invasive species that messes up the environment a lot if not careful. They might have stow-away pathogens on their ship, or bugs or what-not, and those things might show up and start wiping out the pre-existing biodiversity. But, getting back on track.... 1) is there anything on the planet that can immediately kill us? Be it massive predators, weather events (ion storms, fire rain, etc), pathogens, etc? If it's an Earth-like planet, then chances of radical weather is probably slim, but even Earth has crazy hurricanes, tsunamies and such.. so, stilll .. from there you go down the survival list... 3 minutes without air 3 days without water 3 weeks without food 2) is the atmosphere enough to support humans (assuming no pathogens to kill us). If not, do we have the resources on-hand, or available on the planet to make oxygen scrubbers or such until humans can adapt? 3) is there a water source to fill the needs of our colonists (b/c humans consume a lot of water, not just drinking, but for hygeine, cleaning things, etc). 4) is there an ample food source? Are crops and animals we're used to able to sustain there, or are there food sources we can use naturally occuring there? From there... 1) if we're using a technological crutch to sustain ourselves, will we get wiped out if we lose that crutch (extinction level event)? EG: Matt Damon on Mars... if he lost his shelter for oxygen, his food, his water.. he's screwed. If humans require some advanced technology to survive, then some ion storm shows up and blasts it all.. oops 2) do we have the mind-share to sustain ourselves? IE: do we have enough people learning to be farmers, ranchers, builders, etc. to maintain the living conditions? If you're using advanced technology to sustain yourself, and you can't educate the next generation fast enough in genetic modification of foods, gene therapy of humans for medicine, etc, then you're rate of survival starts to decline simply because your means of education is drying up. 3) Are we acting like an invasive species? Humans tend to grow into the area they're given, and terraform it along the way. As humans start to cut down trees to make fields, add industry, etc, they'll just end up with the same situation we have on our planet; where we lower the biodiversity of the natural planet by destroying ecocystems in order to sustain ourselves. Eventually, humans have to act like caretakers of the world, or come to some kind of balance with the ecosystem to ensure it can still sustain them. 4) do they have sufficient waste management? A colony won't do so well if it's not disposing of it's own waste efficiently.. which cuold become a cesspool breeding source for pathogens. They might want to use their own feces to create energy (methane) or fertilizer, but if it's mihandled it could contaminate everything and give everyone a really bad time. Other factors... a) humans will adapt over time. Humans are the millions-year culmination of DNA / Biology adapting over time. So, given enough generations, humans might adapt to better handle the environment. b) with sufficient technology, the colonists could hyper-evolve, essentially rewriting their genetics quicker to better cope with the new world (think of the movie Pandorum, where the colonists were injected with an accelerator to help their genetics evolve quicker to adapt to the planet during their own generation instead of waiting for many generations to do so... which went to utter crap when the ship screwed up and the colonists mutated into cannibal monsters). c) are they producing enough replaement population to grow and make-up for unforseen attrition? EG: if there's a plague that comes out of no where and wipes the colony, is there enough population to bounce back? Are they breeding enough? With enough technology, you can "Sci Fi" deus ex machina your way around a lot of problems. 1) the colonists may have accelerated genetics, so they can quickly adapt to the planet, including all pathogens and such 2) they might be genetically modified to not have to "eat" normally or use the bathroom. IE: they are genetically optimized to take in nutrients, maximize usage, and recycle all byproducts into somethign useful. This would require a very high-tech society. It elminates a lot of burden of 2) the colonists have the ability to grow food, even protein, wihch takes the burden off feeding themselves 3) the colonists have "easily replaceable tech".. so if an energy storm wipes out stuff, they either can easily replicate the stuff they need or they have advanced brains and can quickly create advanced tech out of sticks and stones. (Rick & Morty that crap together). etc, etc, etc So, food, water, air... but also check for pathogens, statistically analyze planet to make sure not over-populating it, etc. [Answer] In my post number 8 in <https://historum.com/threads/generation-or-sleeper-ships-which-would-be-the-better-more-realistic-option-for-space-travel.181701/>[1](https://historum.com/threads/generation-or-sleeper-ships-which-would-be-the-better-more-realistic-option-for-space-travel.181701/) I state that with slower than light speed travel the main method of settlement in our solar system would be via many artificial space habitats, and the main method of interstellar colonization would be by fleets of generation ships that would build more space habitats out of asteroid and comet materials in the solar systems they reached. So in my view the normal method of colonizing a star system would be by using asteroid and comet materials to build new space habitats in it. And it would be comparatively rare to find a solar system with a habitable planet to also be colonized. Systems with planets that could be terraformed over centuries or millennia to be habitable might be more common than systems with already habitable planets, but such systems would have to be settled and already have large populations in artificial space habitats in order to begin vast projects like terraforming planets. So an expedition to a habitable exoplanet that is 500 years travel distant, at whatever travel speed, would be somewhat similar to the proposed fleet of generations ships, each ship having thousands of people in it, that I described. Nobody would send a colonizing expedition with only fifty people in it and the expectation that there wouldn't be any later expeditions to that world for centuries. Fifty persons are not enough for sufficient genetic diversity to maintain a healthy population. Hundreds or thousands of persons would be necessary for starting a colony with enough genetic diversity. So 50 people are not enough to start a colony unless they bring along thousands of frozen embryos and artificial incubators for them. And fifty people would not be enough to have all the skills or time to perform all the tasks needed f to maintain a civilized community. Not unless many thousands of highly advanced robots also come on the voyage. Therefore, the colony expedition seems more likely to be some trick to get rid of the colonists than an attempt to create a viable colony. Possibly the colonists are political opponents of the government and also fans of less realistic science fiction stories, and are tricked into making a colonizing expedition that is fore doomed by inadequate preparations and numbers, presented as a more merciful alternative to execution. That sort of reminds me of the ending of the *Star trek* episode "Space Seed". I can't help thinking how unrealistically successful that colonizing attempt turned out to be in the sequel *Star Trek II: The Wrath of Khan*. [Answer] According to [this question,](https://worldbuilding.stackexchange.com/questions/157298/would-it-be-easier-to-colonise-a-living-world-or-a-dead-world) the first priority would be to sterilize the entire planet. There is basically zero chance that there would be any biocompatibility at all between alien life and Earth life. [Answer] The first steps really depend on what challenges the specific planet has in store. Unless something totally unexpected about the environment is discovered upon arriving, the first step would probably be to place and ship in orbit. Wake up Generation 0 from sleep and starting sending landing parties and drones to explore and perform tests on the environment. But keep the bulk of the passengers (Gen 1, Gen 2, etc.) in cryogenic sleep until they are safe and needed, which could perhaps for decades. [Answer] Why not start by taking over some plants and basic life forms a la [panspermia](https://en.wikipedia.org/wiki/Panspermia). See if these actually survive, and thrive on the planet. Is it actually habitable? This could be done by robots or other autonomous machines, and then the same robots could run general data collection on the planet once they are there. To take humans over before anything else is probably being overhasty. [Answer] # #1 Top Priority? *Family* I sincerely hope the colonists were informed of just how many babies they are going to need to make... And babies require a lot of resources, not just because they need somewhere to live, but they will also need training, work, and the encouragement to have big families themselves. That means your colonists have Zero time for getting curious about that planet. They need infrastructure now, not in 100 years time. Fortunately, they have just arrived in a solar system with a star, asteriods, planets of all shapes and sizes, and no few moons either. Even better they are not in the gravity well of any planet which means they are already 80% of the way to all of those resources. Infrastructure shopping list (roughly in order): * Lots of Autonomous Droids. (Mining blimps, constructors) * Communication, mapping, and monitoring satellites * Mining and Refining (water, metals, carbon, oxygen, hydrogen, and more) * Factories and Shipyards * Living Space (Lots of it) * Civil Society (Schools, Shops, Libraries, Hospitals, Government, Law, and more) * Space Elevators (Why not put a ladder in first? They did come to investigate the planets) * DHD (Dial Home Device, a.k.a giant communications telescope pointed at Earth. - it might be 500 years out of date but Earth might be sending useful information, might be nice to say hi too. But if communication isn't possible then if the colonists left Earth on less than pleasant terms warning of an invasion would be nice, or answering what happened to Earth to try and not do that too...) They could try and build a Dyson Array (for power generation) but they should avoid that before establishing a tolerable government and reasonably effective and restrained navy. A Dyson Array is a stellar powered laser after all, care needs to be taken to *not* use it as a death ray. Also taking a look at our own human genetic lineage, you will probably need something more inline with 40,000 souls on board your expedition to provide enough diversity. If there isn't any space for more people, perhaps they could instead bring a large genetic library, and perform IVF. They shouldn't even consider landing on the planet until the population is well into its first million. [Answer] The posed question is about **after** landing on the new planet. In the given scenario, we're limited by "current technology" and we need to travel by 500 years. Even if the ship's crew is safe, the Earth will have changed, so going back to Earth is worthless. And it was said that all needed resources are supplied by the ship. So, the next steps: 1. Mix up (over power?) with local life forms; 2. Create hybrids (dress up?) with local life forms, especially the intelligent ones. We need to mix up with new life forms, if they're "intelligent", or we can dominate them if they're "not intelligent". The best way to profit from the new environment's resources is some type of mutation (actually something expected after so many years traveling in space, even in cryogenic sleep). ]

[Question] [ This is about a world which is quite similar to Earth in many respects. It has continents, oceans, mountains, fjords, humans, and every other property Slartibartfast might be more or less proud of in his work. It *also* has a species of wilderness-living, large (roughly between the size of a large dog and a large feline), sapient, intelligent, land-dwelling carnivores. These live in groups and do not have any magical or supernatural abilities. In other words, what you might consider just another species of group-living animal, just a very smart one. Naturally, not having evolved from apes, these creatures' intelligence is rather different from that of humans, but it is of a similar level. These creatures have evolved alongside humans, so the way I have it so far, insofar as there has historically been interaction between them and humans in the first place the two species have pretty much grown accustomed to each other's existence. For the most part, these creatures are happy to live their lives with minimal interaction with humans. Some might tolerate or even enjoy human company, but most are relatively indifferent to humans. (That isn't cast in stone, however.) They might, at most, defend themselves or their offspring if threatened. As such, for the very most part, they are not a direct threat to humans, and they pose little threat to for example humans' livestock. They are, however, decidedly carnivores, easily able to kill an unprotected human should they see the need to. The humans of this world are largely the same as humans of our real world. I could just hand-wave it all away, but one issue has been gnawing on me for some time. **How can I make sure that my world allows for the continued existence of these creatures as well as humans as we know them, through history and into the future?** I could put these carnivores and humans in different parts of the world, but as we know, particularly humans aren't exactly known to historically have stayed put, so especially in recent centuries, almost no matter where on Earth I put these creatures, humans will have encountered them, and might very well feel threatened by the existence of such a creature that they had no idea even existed. Another alternative would be to accept that these creatures and humans will need to know about each other from early on, and give them overlapping ranges (and have the humans learn to act non-threatening to these creatures, as well as for these creatures to largely ignore humans), but again as we know, humans haven't exactly embraced the idea of sharing their world with other species, particularly large and potentially dangerous ones. **What are realistic options that don't break suspension of disbelief too much?** [Answer] Give the carnivores and the humans reasons to need each other. These probably aren't a matter of fundamental biology, but could be social, religious, or commercial. If it's traditional for human kings to be guarded by mercenary carnivores, this could be something like the [Varangian](https://en.wikipedia.org/wiki/Varangian_Guard) Guard of Byzantium. Humans could be valued as doctors and craftsmen by the carnivores, because they have *hands*. The species have different strengths and weaknesses, so there are things they can do for each other, if they're wise enough to take advantage. [Answer] In addition to John Dallman's answer; you're probably going to have to put yourself in a slightly different headspace than a western-thought modern man is used to. In western thought there is a very "Kill it with Fire!" reaction... as long as the threat is new and 'present'. For the most part, the only real thing that is going to bring conflict is going to be competition for resources/lack of resources (...like food). Humans in the areas with these predators might become mostly vegetarian, or consume fish primarily where the predators do not live/hunt, to avoid the conflict. (Or they could trade fish for the predators' fresh deer kill.) Likewise, the predators could learn that those [*strange hairless two-legs not-foods*] get very violent when you eat their companion [*four-legs foods*], making it more trouble than it's worth. I envision that most cultures that spend enough time around these predators' ranges will adapt and it will be 'just the way things are' for them, especially if the carnivore behavior is logical and predictable. If you always know these beasts will not attack unless you attack them first (or otherwise provoke them), and that is *consistent*, then you are going to be much more worried about tigers, panthers, bears, wolves, mice, rats, grasshoppers, etc. first. Predictable is manageable; random acts are not. Humans are logical enough to deal with actual threats before dealing with potential threats... and if the "potential threat" is around long enough without actualizing, then mentally people will start sticking more "potentials" in front of the "potential threat" (potential potential potential threat). After enough time people just move them to 'can be scary, but not really a threat' (large dogs/horses/elephants) category. This will hold true until colonialism starts to take hold of the world; the politics and policies of expanding empires are likely to bring them into direct conflict with humans. This could result in some precarious situations where some politicians are likely to go "they're not human, kill them all", unless their interaction with humans is akin to your average cloud; almost none. What happens at this point depends on relative populations, technological advancement, and adaptability of each side. To actually answer the "keep them alive" question, your best option is going to be to shift the definition of human over time. Instead of the carnivores being part of the "them" in the "us vs them/the world" equation, you bring them in on the side of "us." If they are part of the human group/tribe/heard/pack, that majorly shifts where they fit with your average humans' thought patterns, and sidesteps any "kill them all" thoughts. Basically think about what has happened with *man's-best-friend*; wolves/dogs. They've been around so long and part of human history so much that most dog owners consider them part of their household as members (if not fully equal). You may kill a mad dog, but you don't go and kill ALL the dogs. They are part of "us" more then they are part of "them" subconsciously, and more or less have been bound to live in some form as long as humans do. [Answer] Humans and this carnivore should easily be able to coexist. The key to this is that the carnivore is intelligent. [](https://i.stack.imgur.com/aQ5qzm.jpg) [](https://i.stack.imgur.com/vku4Am.jpg) Here's examples of two humans coexisting with what would definitely qualify as a carnivore that is more than capable of taking down a human being with little to no effort. It already happens in real life! We even tend to call these majestic creatures "intelligent," though I do believe we use that word in a different way than you intend. No tiger is ever going to discuss Shakespeare with us, or engage in science or engineering. That requires a different level of intelligence. This actually makes your question easier, not harder. The disclaimer that is *constantly* attached to pictures like the beautiful ones above is that these tigers are **animals.** They are governed by instinct, and that instinct includes killing other creatures, even human sized ones. Dangerous animal handlers are constantly reminded that if they ever get between their animals and the animals' instincts, they will lose because the animals are governed by those instincts. If you assume your carnivores are actually intelligent, by human standards, and sapient, then we can apply [Maslow's hierarchiy of human needs](https://en.wikipedia.org/wiki/Maslow%27s_hierarchy_of_needs) to them without too much handwaving. [](https://i.stack.imgur.com/BJ5qw.png) As you see, food is very low on that hierarchy. For intelligent creatures, the mere fact that they are a carnivore matters little until you stress them so much that they have given up on self-esteem, family, and security of their health. Only at the very bottom does their drive for food govern their actions. So what really matters is not that they are carnivores at all, it's that they are a dangerous creature which has developed extremely effective ways to kill a human. Once again, I find it meaningful to turn to prior art. We have examples of dealing with this in our real world. With a warning that the next few videos contain quite a lot of violence, I'd like to show you just how many dangerous creatures with [extremely](https://www.youtube.com/watch?v=N-ss_OfxsgA) effective [ways](https://www.youtube.com/watch?v=F5M3Jg2pN50) to [kill](https://youtu.be/nIp9UxKrerA?t=1m30s) a [human](https://www.youtube.com/watch?v=yBlHjT2r8Qw) are around us today. There's a very good reason why our own race has been given the nickname "The Most Dangerous Game," well above lions and tigers and bears. And as violent as those videos are, remember that that is the portion of the violence that those groups are willing to portray to the civilized world. The reality is far worse, and brings us towards some of the more [terrifying](https://youtu.be/I5Zi-Jm9DVk?t=1m10s) weapons [humanity](https://www.youtube.com/watch?v=V5DU-uoLwj4) has ever [created](https://www.youtube.com/watch?v=ZFNW3heSkq8). So what permits us to live with the "animals" we see in those videos? Culture and society. We've constructed an environment where it is in their interests to not engage in such activities. Using Mavlov's pyramid, we seek to give them ways to strive for things like morality and creativity, so that they don't find a need to bring their special set of skills to bear. In your case, I see no reason why there would be an exception here. If that carnivorous species is sapient, like you say, then we would strive to communicate with it, and understand what they want -- understand what they put in that pinnacle of Mavlov's hierarchy. Then, we would create a society which encourages that. You ask how to make such a world realistic. The key to this is that you won't see all of the factors which add up to success in one big layer. They will be distributed. You will see facets of it at every level of society. Why? Because we don't always have the opportunity to approach things from the top down. Sometimes you need to deal with the needs of a killer right here, right now, and don't have time to bring in all of those high lofty concepts like justice. So society would be structured so that, at every level of its fabric, the killers are given something else to do which accomplishes their goals better than killing. There would have to be some concept of mutual respect. Why? Because that shows up in the esteem category in Mavlov's hierarchy, right near the top. If humans and the carnivores don't respect each other, there will be trouble. This will likely result in a series of mutual rituals built into society. Consider how, in our society, we often look at people and nod at them, acknowledging their existence (unless you live in a big city, in which case you acknowledge them by intentionally not looking at them). This acknowledgement is key to building a healthy relationship. In all, look at human societies for how to answer this question. We already have killers in our midst, and in general most of them choose not to exercise that skillset because they have better things to do with their life. How we keep it that way will be a treasure trove of approaches for dealing with your carnivores. [Answer] Humans already do coexist with various intelligent carnivorous species, most notably other humans. As we've seen time and time again, the bigger problem isn't carnivores eating humans, it's the other way around. The carnivores have reason to be afraid. If humans benefit from killing them and do not fear repercussion, the humans will certainly kill them, or enslave them, as has happened countless times to families, tribes, cities, or even "races" in human history. There are 2 ways the carnivores can prevent being enslaved or being hunted for their balls (to make prehistoric Viagra): * build a civilization that can defend themselves and has sufficient leverage with human nations to enforce equal treatment * live as slaves until humans in a renaissance-like era decide to increase their status There are other less likely options too, such as enjoying the protection due to a religion, like the famous sacred cows. [Answer] > > Some might tolerate or even enjoy human company, but most are relatively indifferent to humans. > > > Sounds like some carnivorous creatures I know... Let them have insanely cute young! Throughout human history they have been revered - sometimes but not always, as gods - but at the very least, as companions to humans, with complementary skills, wit, talents and tastes. Purrhaps they are happy to let us rear their children up to the age of puberty or at least the stage of diminishing cuteness. (There's a long tradition in Celtic culture of fostering and raising the children of rival - or even sometimes enemy - clans, as a way of increasing bonds or at least decreasing tensions between natural enemies. Same may apply between species) For the intelligent predators it may have some advantages - perhaps it allows both sexes to hunt in their best and fittest years, unlike humans where one sex stays close to the cave while the other roams far and wide to bring home prey. (A pattern still somewhat in evidence today). For the humans ... well, look around the internets and deny the human appetite for cute, if you can... Of course it will never be quite clear if we are their servants, or if their young are our pets ... or will it? [Answer] Hmm, good question - and a tricky one, given our propensity to kill off or squeeze out anything that competes with us for food or land. But that propensity is by and large **after we invented agriculture**. So start the process off earlier. Sooo... they are pack-living carnivores. That means they are in **direct competition** with other pack-living carnivores (of all sizes), as well as with big solitary carnivores. The same way that lions and hyenas compete, or lions kill cheetahs or leopards given half a chance. But these guys are smart. So those other carnivores - wolves, lions, bears, sabretooths or whatever - don't stand a chance against them. The smart carnivores will squeeze them out, exactly the same way that humans will squeeze them out later in history. This would be of benefit to Stone Age humans, particularly when they are just starting to invent pastoralism and herd goats or cows about. If the humans moved into a land occupied by these intelligent carnivores, it comes pre-tamed. They don't have to worry about lions and tigers and bears (oh my!) because the intelligent carnivores have suppressed those populations. And because the intelligent carnivores and the humans are both smart and can recognise that the other is smart, agreements/truces can be reached. Carnivore: Please stop chasing away the deer! I need to eat them. Human: But they keep eating the grass that my goats need. Carnivore: How about I camp out on the edge of your field and eat any deer that come near your grass? Human: Deal! If the two species have been in 'symbiosis' for several thousand years, there won't be any problems until humans get to the 'fence in the range' stage of agriculture or the 'chop it all down and turn it into a palm oil plantation' stage of agriculture. (Well okay, there will always be some idiots murdering each other over a dead cow, but it will be local not genocidal). The two species could even spread out of Africa together. Slowly conquering the globe bit by bit in a loose partnership. Bands of humans who don't cooperate with the carnivores (and vice versa if there is advantage to be had in the other direction) are at a disadvantage. What have we got that the carnivores might want? Give them our unwanted bull calves and roosters instead of culling them. Give them our dead to eat? The carnivores in this scenario will have to keep pace with humans in technology. If they stay Stone Age and we make a Great Leap Forwards to Iron Age, industrial revolution etc, they'll get squeezed into marginal lands, as stone age tech-level human ethnic groups are today. [Answer] That is quite easy. Most predators are actually nocturnal, the hunting begins at dawn. We as humans are sleeping during the night (especially if we are hard working), the intelligent predators are hunting at night and mostly sleeping during the day, so we have not much overlap in the activity. The predators will have excellent senses and experience, so trying to hunt them at night will be suicidal. All other interactions will develop naturally. As Marky noted, the predators need to be consistent; it must be possible to set boundaries for both parties. After raids on human dwellings the predators understood that humans are intelligent and that they are capable of stockpiling, a trait which they are not able to learn because they are impulsive and have a ravenous appetite. So they respect human boundaries if they are in human areas and tolerate human activity (wood, mining) in exchange of food. You can decide if they are able to make tools (allowing trade). Some of them have learned to stay awake during the day and offer tracking, finding routes and bodyguard service. As long as they are reliable and can be trusted, I see no problem with coexistence. That does not mean that they will tolerate everything, e.g. humans strolling around during the hunting phase (humans are learning quickly; like we do not tolerate pointing guns at humans). They also should know if humans are hostile to them; if someone kills a predator or is speaking openly that those predators should be hunted...you could decide that those people will face...repercussions from the predator's side. [Answer] This is very similar to the question of how multiple intelligent species could survive on the same planet. If human evolution is a guide, then the best adapted species will outcompete its cousins, much like the Ancestors are thought to have done to the Neanderthal or Denisovans. So the real key is the various species must have evolved in sufficiently different biomes that there is no significant overlap of living space or resources, so the two species never come into competition with each other. This sort of rules out your carnivorous species being like wolves or bears, since they do live in the same biomes that we do, and the Ancestors were not the sort of species to be put off by small things like mountain ranges, ice ages, carnivorous megafauna or oceans. If anything, the other species might resemble Orcas (which conveniently are carnivorous) which live in the oceans. The two species will eventually discover each other at the interface between the biomes, and see each other as the strange spirit creatures from the "*other place*" who can talk after a fashion and can occasionally be persuaded to trade wonderful and magical things. [Answer] I am really sorry for that, but the sad truth is... # Humans can't coexist with any intelligent species. We can't coexist even with a different culture. Maybe it takes centuries, maybe there is a total war with them from the first moment, but at least one of the conflicting cultures will disappear. **Check the history.** Thus, in my opinion, the answer is a clear **no** in the first line. If they are carnivores, it will mean probably total war from the first eaten child. What can help: have some **separation mechanism** between them. For example, the carnivores can live only in the wilderness, out of them they are weak. Or, they could/should live in geographically separated regions. For example, if they can't survive in the cold, so they would be common around the Equator, but they won't to north. In this case, you can create a # cultural co-evolution between the species. They won't ever love eachother, but they (from both side) will produce cultural standards and customs to minimize the very bad things. But, the carnivores will still regularly eat some humans visiting them, while the humans will * enslave them * let them fight in arenas * cage them and show for money to the visitors in zoos. Technical civilization won't help too much in this. If the carnivores are intelligent, they will also have firearms. If they aren't enough intelligent enough for that, the humans will exterminate most of them, and then show the few survivors in a zoo. And, in the technical civilisation, the communication and trade lines are much faster, which leads to much faster switching in the political processes. The existence of the native Americans was enough for us to exterminate them, what would we do with intelligent lions taking our children to the wilderness to let them eat with their cubs? [Answer] Two possibilities popped into my head right away: **1. Disease** Remember when Chris Columbus and his buddies came over to the New World and accidentally wiped out a millions with smallpox? Or when one of the Martians in *War of the Worlds* catches a cold and they all die? Or when Caesar from *Rise of the Planet of the Apes* destroys humanity with an aggressive ape virus? Disease is easily one of the biggest dangers of interacting with another species, especially one from a completely new part of the world. Make Ebola, a mildly inconvenient disease for the Carnivores (like the flu for humans), endemic to their habitat. Any human who tries to live near the Carnivores soon dies to Ebola. Put the Carnivores in a region with no naturally-occurring ores, and poor farmland (just generally unattractive for human settlement). Combined with the Carnivores' natural apathy for humans, it's unlikely that the two species will ever clash. **2. Religion.** Alternatively, let humans follow a Pagan religion where they regularly worship the spirits of nature and sacrifice meat to the Carnivores. The world government is a theocracy, and harming a Carnivore, a holy vessel (not entirely unlike the cow in Hindu mythology), is punishable by death. [Answer] The carnivores will be adapted to hunting their prey. There is no reason to assume that their prey includes humans. For example, the only lions and tigers that hunt humans are the old and infirm ones that can no longer hunt their usual prey. This makes co-existence between the two intelligent species very probable. Provided there is only a small overlap in their ecological ranges. Recent studies have shown that where species that occupy similar ecosystems co-exist, for example, wolves and dogs, the original species occupying the ecosystem can undergo a population decline. It is possible this is the reason why Neanderthals went into decline and eventual extinction. The presence of humans (H. sapiens sapiens) modified the ecosystem they shared to the detriment of the Neanderthals. However, if the humans and carnivores share the same territory but do not share the ecosystems, then co-existence can occur successfully. [Answer] Humans have lived with carnivores for long times. Old hunters tamed wolves to hunt alongside them, using them to herd the prey where they could lure it in a trap. So I'd say a benificial relationship between the two. Humans can provide cooked food, herbs, medicine, the carnivores get to help hunting, scouting, surviving in rugged terrain. So i'd say the carnivores will be like sherpa's eventually, guiding humans through unmanageable terrain(e.g, anything not plains like mountains, jungle, forests, icefields). Humans are first and foremost plains people, we like to live and colonise flat surfaces like plains or shallow hills. If it's not flat, we make it flat. This leaves ample terrain for the carnivores, which prefer the rugged nature, like mountains, forests, fjords, deserts, etc... There is little competition from humans there for terrain. There can be a few wars to make things interesting, since that's in human nature for when mining starts and it's some sacred land for the the carnivores. But i'd let it be as a cooperative relationship, where the carnivores trade their for humans difficult to obtain goods(jungle spices/fruits/plants/animals) for medicin, iron, crafted works. Depending on culture/knowledge there are different paths to thread [Answer] Assume that humans and the intelligent carnivores both evolved in Africa. That way the two species can have learned to live together. The simplest way for making the two species get along is to make the sapient carnivores highly territorial and have them confined to their specific ecosystem in Africa. This could be, for example, in mountains, the jungles or the deserts like those of sub-saharan Africa. A territorial species is likely to remain in its home biome. Competition between the two species will further encourage humans to leave Africa and embrace the wider world. Out of Africa to find safer territory for humans. The carnivores will remain in their native habitats. Being intelligent it is probable they will develop their own technology, but this doesn't prevent from acquiring human technology and using it for their own purposes. If the two intelligent species can communicate, the carnivores may effectively establish their own 'nations' with their territories. Humans may have the rest of the planet, but part of Africa will be forever carnivore country. But this will be an Africa that is both the place of origin and the home to two intelligent species. It's not possible to go further unless the OP was more specific about the type of organism that evolved into the intelligent carnivore. For example, if the carnivore had evolved from, say, a bipedal crocodilian or from a carnivorous primate species. [Answer] This depends highly on the state of the world you are designing and also on what the other race is supposed to be exactly. Also it may depend on what degree of coexistence you mean... **Coexistence type** Fantasy-like world where humans and the others live intermingled in the same cities and villages more or less in harmony (give or take some speciist discrimination etc.)? cold war-like situation where world is divided among the two races which are essentially a no-go areas for the other species? Or do you mean something like our coexistence with Native Americans of these days (unless they assimilated, they have been mostly killed off in the past and live in specially designated concentra-... I mean reservations)? **The other race:** You need to define their habitat, their approximate biology and psychology. If they are terrestric, they are bound eventually to come into contact with humans and directly compete for resources unless they live naturally in an environment very hostile to humanity (deserts, high mountains, arctic regions). Forests/jungles do not help, quite the contrary - even vegetarian humans will be very likely to burn them down constantly to gain new territory for agriculture. How do they stand against a human? Are they more like an intelligent cave-bear or T-Rex that can easily take down a group of humans unless they have special equipment and/or plan? Are they intelligent carnivorous squirrels? Or something of tiger level? Can they overcome their biological limitations as humans do? In other words, can they use tools and other body extensions that allow a human (essentially a degenerate hairless ape that is with some training good at running) to stand up against creatures that would stomp them to the ground or tear them to pieces instantly? Do they build structures and do they have means of retaining knowledge across generations (writing, eidetic memory, genetic memory)? Are they limited to one continent or are they spread around the world? What is their political tendency? Are they individual loners or do they tend to group and form tribes, confederacies or nations? Do they have internal variability similar to humanity (a number of visually different races, thousands of mutually incomprehensible languages,...) or lower/higher? What are their spiritual attitudes? Are they religious (I mean again like humans, who at some point interpreted the world universally in a way that we might call religious)? **State of the world** Pre-modern era - now this one is the easiest. Necessarily, there are likely to be wars between the two species (long and nasty ones) where there are contacts, but people at this age typically more or less stayed put on the spot and moved only under some special circumstances. So with some effort it might be possible to create a cohabitation on more or less equal grounds. Modern era - this one is difficult... here the humans (basically the western civilisation that gained a headstart over all the others) started to expland wildly, which resulted in total extermination of other civilisations and entire races (think of Native Americans - estimates say that Americas were inhabited by some 50 million natives, who were massacred intentionally or unintentionally in 4 centuries to the level of extinction). So will the other species take the historical role of Native Americans and experience a mass genocide? Will they be in the role of African slaves? Or will they preserve, modernise and eventually prevail like the Chinese and Indians did? Or bits of everything depending on the location of each of their tribes/nations? Or are they the ones going to be the aggressive expansionists enslaving or exterminating parts of the humanity? Post-modern era - essentially today, where the focus of most post-modern nations moved hugely from external expansion to internal development and where we realised what terrible things we did in the past decades and centuries to ourselves and to others; but also an era where the fears of resources drying up start to surface etc. [Answer] If humans start building large and complex societies (e.g. bronze age cities) then they will almost certainly seek to enslave at least some of these carnivores. In the very long term this might lead to the creation of a "domesticated" breed in the same kind of way that dogs evolved from wolves (although the details would certainly be different). See also <https://en.wikipedia.org/wiki/Russian_Domesticated_Red_Fox> on a controlled, deliberate domestication experiment. This creates a new dynamic: how does a sentient domesticated species think? How do human institutions arrange themselves? Are these creatures considered chattels? Is there an emotional relationship between human and carnivore? If so, how is it considered in law and custom? There are obvious parallels to slavery here (except the sex abuse angle would probably not be anything like as common), which might be too uncomfortable. For instance if you were to create a world in which the domesticated variant is like a sapient dog then its going to feel a bit like an airbrushed version of historical slave societies. On the other hand this might make it an interesting area to explore. I've often wondered what would have happened if neanderthals had survived into modern history. Probably something similar. [Answer] ## Australia I would suggest putting them in Australia. This will give them the opportunity to evolve and exist relatively un-disturbed by humanity until the 1600s. I know this will be unpopular with the humans who were actually living in the continent in real life, but if you want your fictional carnivores to exist on Earth, this is their best chance of developing in isolation. In your altered reality, some humans may have arrived on the continent over the millennia -- the same ones who in real life would become the aborigines -- but in your reality they would have met your carnivores' society and they would not have been able to settle. Maybe you have a few scattered outposts of humanity on at key points around the coast, but most of it dominated by the carnivores. The two species may well tolerate each other without conflict, and may even interact. With this setup, the arrival of Captain Cook would be an entirely different event. The discovery of not only a new continent, and a load of new species, but a new sapient species. At this point, the questions are: how long will it take the arriving Europeans to realise that these carnivores are intelligent? What will they do about it when they do realise it? My guess is that once the humans work things out, they will start out with an aggressive attitude and there will be a minor war that will end with the humans accepting that they don't have the resources to fight a major campaign on the opposite side of the world. After that, they maybe spend a hundred years or so sending the odd tentative expedition to make contact, but real meaningful contact will only grow later, once the anger and recriminations have faded. [Answer] Several people said to put them in Africa/Australia/near the equator. But what if you put them north. Even now, there is very little human population north, and most of them live on meat already. Look at the Inuit for example. They could evolve north, feed on meat, and over time develop technology to more easily feed themselves(Fishing for instance). With the humans coming from Africa, and the carnivores from the north, you have a good separation at the start. Any early meetings would probably end in annihilation of one group, but it would also ensure some technological exchange to happen, thus keeping tech levels similar. Then, as we move into modern era, we would learn to coexist. There still might be wars, but as they are unsuited for warm weather, and we are unsuited for the cold(Since the only way for us to exist there is technology, and we wouldn't even bother with inventing it so much if there was a strong historical bias against it) we might just not dwell into each other's area. Then we(us and them) start the companies, which don't distinguish between us since it's more profitable to have them working where they're better suited for it. Another thing to mention is cooperation over a greater threat. If we have a stronger historic enemy that we share, for instance a much larger predator that attacks us both, we might find that cohabitation provides better protection than sole survival alone. Over time, we would see each other as partners, and be in a symbiotic relationship. [Answer] It's likely they coexist automatically without any special settings, if there is plenty of food. Note that human eat meat too and there is nothing special for a human to live with another human. Why do big animals kill humans? If humans decides to revenge, they have virtually no chance to live. The reason they do is that they are not intelligent enough to realize this. For a species as intelligent as humans, they could have their own armies to protect themselves. But it's much more preferable to prey on easier targets. If they are like humans it's very likely they have their livestock in their farms. It doesn't really require explaining how human morality is formed. That's more likely the result of the inefficiency of causing too many conflicts unnecessarily, in this perspective. It's unlikely they were always peaceful in the history, though. [Answer] A bit late to the game here, but work with me. I'll suggest that it'd help if each species found the other, well ... sexy. A mutually profitable exchange could occur. Lonely humans would discreetly wander over to the carnivore village bearing gifts of venison. Lonely carnivores (if they have some kind of "alpha male gets all the broads" dynamic going, there could be lots of these) would come with their own gifts. Everyone has fun, nobody gets knocked up. Over time, the two peoples might evolve other uses for one another. Imagine a doctor who can't catch your diseases. Carnivore trackers could shine on human police forces. Depending on what the carnivores are like, the humans might have talents which come difficult to the "carnies". [Answer] Could the humans be extremely toxic or extremely foul-tasting to any carnivore who tries to eat them? [Answer] humans do eat meat too. and some human groups were cannibals and eventually stopped that behavior. we also don't eat animals that we depend upon (horses, dogs), but that too is evolved and not universal. so all it takes is to recognize the intelligence of humans by that species and the development of a moral code, just like we don't eat our own kind, we also don't eat any other intelligent species. in a way the relationship would be like to aliens from other planets. recognizing the intelligence and incorporating that into morals seems a natural step. and once that point is reached, the continued existence of both should not be a problem. the only question then is, how did things get to that point? and just as cannibalism evolved and got reduced, the relationship between humans and this species too can evolve over time. humans may fear these creatures, but that doesn't mean that killing them all is our only choice of protection. also, they are intelligent, so hunting them down may simply proof to difficult. we also know some dangerous animals who simply won't touch humans unless provoked or threatened. (horses, elephants, and other large or even small animals) they are dangerous because they can easily bring down a human, should they see the need to, but they are not dangerous in that they don't have a natural tendency to do so. in that sense this species may also simply not be dangerous. i can't think of any carnivorous animals that don't naturally attack humans (bears maybe?). although that actually demonstrates a point. a species need not be carnivorous to be considered dangerous. especially an intelligent one. they could want to kill humans for other reasons, for protection or when in competition for resources. much like different human groups go to war. it is actually conceivable that these intelligent creatures and humans have been at war with each other, and just never had one kind permanently dominate over the other. wars continue until today. and they may continue in your world too, but as long as one kind does not permanently dominate over the other, and there are enough resources for both to remove the need for war simply to ensure survival then they may coexist for times to come and eventually develop permanent peace. [Answer] Religion/believe could be a very strong bond. It is not guaranteed to survive 'forever' and you would need to find a good way of 'introducing' it in the past, but once established it could be the 'need' of each other that preserves peace. Maybe one race is responsible for the afterlife of the deceased of the other? Maybe there is eve a believe of rebirth in 'the other' in an endless loop? This could go as far as that 'high priests' of each race have to live a period of time with the other to 'learn' or such a thing. [Answer] Opposable thumbs. Humans are small and weak, but their agile cute tiny fingers can pull those pesky little bugs out of the larger beasts ears. Sometimes this is hard to do with large paws or hooves, especially if claws or talons are attached. Humans can tie knots and make ropes. Any huge Tiger-Elephant can knock down trees and scoot the logs together for shelter from the wind. But human can cut them at precise angles and make them water and air tight. Sleeping caves can flood and kill off your whole pack. Humans are good swimmers. Humans can bend rocks when they get them hot enough that the shiny stuff drips out. That can be hard to do when your fur catches on fire when you try making rocks hot. Humans fight a lot, so having a huge beast to protect them from other humans comes in handy. The Beast might enjoy NOT having to hunt, with humans providing meals out of gratitude. Meals made with those weird plants added to the meat before they half burn them. Some humans might feed a beast his/her enemies. Humans think they look cool riding on the back of a huge creature, so they can more easily throw spears down on the battlefield. Feline and Lupine hunters LONG ago on Real-Earth began enjoying the company of humans. [Answer] ## Could and Would are entirely different things You've asked if we could co-exist, this is reasonable as we certainly *could*, but it's important to consider if we *would*. Historically we've been particularly bad at co-existing with ourselves, let alone other species. Anyone different was variously exiled, killed, persecuted, invaded etc. Taken as a species we've been consistently at war with ourselves for thousands of years, contact between any two given tribes as often at the point of a spear as otherwise. We're currently in a period of unprecedented peace and prosperity so we can consider whether we could get on with another species, but considered over the course of our extremely bloody history, one species would have wiped out the other 10,000 years ago, as we did with almost anything else that could challenge our dominance over the landscape. Australia has been mentioned, New Zealand should have been as that was first colonised even later, but in both cases there were pre-existing megafaunae that did not survive the contact with humans. **We do co-exist with certain species**, but we could only call them client species. Dogs, Horses, Cats, these being the ones that we kill and eat the least of all the large domesticated animals. Should this second species adopt a client status to humans it's possible that we wouldn't have wiped them out. It would probably have to have been an early contact, possibly not long out of Africa, if not from within Africa, to become a universal cultural meme. Each surrendering certain elements of life to the other, perhaps they were the hunters and we the farmers and builders. Delayed contact is not an option, that would almost guarantee xenocide. [Answer] **make the humans vegetarian farmers and the beasts nomadic obligate carnivores**. this means the humans and beasts would not be competing for any meaningful resources, and therefore have no reason to seek to eradicate each other. sure, occasionally in a lean year a beast would try to eat a human or two and the humans would respond by killing a few beast. but both sides would know better than to start a conflict, since they have little to gain and much to lose. in most years, the beasts and humans coexist peacefully and benefit from mutual trade (e.g. human steal or hides for beast caught fur or postal service). the humans might annoy the beasts by cutting down trees, but the average nomadic beast would probably not realize the long term consequences of that. perhaps some philosopher beasts would argue the humans should be stopped, but with such high short term cost the idea never gets momentum. this makes sense considering a nomadic predator would probably never form any large political organizations. throughout human history, permanent settlement (aka farming) has been a prerequisite for centralized government. [Answer] I have often given consideration to the type of question you pose here so I will give you the conclusions I have come to 1. Carnivore is not the same as predator. Vultures are carnivores but not active predators. 2. Humans are omnivores and they are predators. The driving factors where two cultures or even species compete is natural resource. For a hunting species that is not omnivorous they must follow the prey and therefore their territory is seasonal and transitory. Humans farm and herd too. Therefore friction will occur where the hunting species' territory overlaps the a static communities territory. It becomes a trial of technology. In a historical scenario you might look at the Vikings vs the Saxon's. In arms and armour the Vikings had a small advantage. In manoeuvrability the longship provided an early advantage. Later when settlement occurred it was the Saxon Burgh (fort) that was the decider. Saxon's could leverage a small tactical victory as a strategic one by fortification or an area. The Native American model is to flawed simply because they had no history of contact and the Indians had no means to catch up with technology. Had the British still been in control of the colony the available man power of an established nation would have made for a much shorter period of conflict. However the long period of conflict drove US technology at a much faster rate of development than other industrialised nations. Only Britain, France and Germany had a similar speed of development in the 1800s due to on going imperial aspiration with Japan playing catch-up at the end of the century. So in summary the factors are resources, opportunity for advancement, and pressure from with out to capitalise on opportunity. A well organised defending human population is a match to a skilled aggressive hunt driven culture. The Romans won against Attila, again an area to look at for inspiration of defending culture vs aggressive, fast moving predators. The Huns were a prototype of the Mongols in warfare. [Answer] The question you should answer is "How would Humans feel if they came across a sentient race of carrots." Carrots running around, building houses, breeding with one another. How would humans interract with a race when they could just reach out, pick them up and eat them, delicious looking carrots. Maybe not carrots for you, but pick a food that you would eat without even thinking, Yum.. now add intelligence.. the pie looks at you, a curious look on its face.. "yes, sir? can I help you?" it asks.. Can you eat it now? How would human society exist, if half of the populace were food for humans? Could Humans exist side by side with candy-bars and chocolate cake as companions? friends? or would we enslave them all, round them up in farms, breed them for better cream filling or prettier frosting.. Would your race, round up humans for breeding and eventual slaughter? [Answer] They coexist the same way humans coexsist with each other: generally well but with flareups and strife and wars. Look at our history, especially examples of genocide and ethnic cleansing and strife, and replace one ethnic or religious group with your carnivores. For example, imagine the crusades happened, but instead of Christian Knights reclaiming Jerusalem from the pagans, it was human knights reclaiming Jerusalem from the monsters. For example, maybe the Great Wall of China was built by the carnivores to keep their prey animals inside and their enemies, the humans, out. For example, imagine the Christian missionaries made great gains converting the creatures, but the Lutheran reformation happened amongst the creatures. [Answer] If you're in the mood to make everyone survive without the two species having anything to do with each other, just make it so that the two species are poisonous to one another. [Answer] Ok... From the comments there are a variety of answers from 'Humans are terrible and will kill them all' to 'they'll get along naturally'. Now, To start with the method they begin to encounter one another: In my opinion, If an animal becomes useful to humans, humans are more likely to keep it alive (unless its only useful for food and the humans are part of a hunter-gathering society). Being a carnivore it stands to reason that it survives alongside humans by a. encountering them early during their hunter-gatherer phase or early agricultural phase and b. by creating a mutualistic relationship in which they help with hunting (if hunter-gatherer society) or with keeping away 'pests' such as other predators or large herbivores (if an agricultural society). Over time this would create relationships somewhat similar to domestic Dogs or Cats. The issue with them contacting humans at later periods in time is that humans are less likely to find them useful initially, and therefore more likely to wipe them out or otherwise treat them appallingly. There is also a problem with them remaining predominantly 'wild' or wilderness living as humans dislike and fear that which we do not know or have some degree of control over. If this intelligent species remains living in the wilderness, there is a higher chance of them being seen as 'evil' 'demonic' and worth hunting to extinction. Over history the role of these carnivores could change depending on the culture and social organisation (for example, royalty could hire them as guards (like a guard-dog or attack-dog) or for wealth and intimidation purposes (look how strong/rich i am, I have this powerful beast under my command). Yes there will be a few instances in history or society where they are demonised: but so have the cat and dog (in some cases believed to be linked to witchcraft and/or soulless). Of course overall there may be an issue with human perception of these carnivores (likely in some cases to not even think of them as 'intelligent' or 'conscious') but otherwise i don't believe it is impossible for the two species to get along. From the carnivores perspective, they could gain easier access to food (especially true in agricultural societies), worship, medical aid and other potential benefits that would make them more likely to stay around. ]

[Question] [ No magic exists in this setting beyond what is explicitly described in this quesiton. The setting is vaguely European medieval. The question centers around a town large enough to support a nobleman complete with his keep. The town knows that shapeshifters live in the wild. The populace has yet to determine the creatures' motivation, but the shapeshifters act to seed as much death and destruction upon the town as possible. Efforts to have a civil discussion with the shapeshifters have failed, and nobody knows where they live, except somewhere in the nearby wild (forests, valleys, and rolling hills). Hunting bands haven't located their homes. They seem equally intelligent--if not more so--than humans, and reports show that they can shift perfectly into a human form within seconds. The exact human form only seems limited to their creativity or knowledge of a specific human's form (if they don't know about a birthmark, they can't reproduce it). They are known to kidnap humans to study them exactly. The shapeshifters have no other known intrinsic abilities. Any container, wall, or shackles that could stop a human can stop a shapeshifter. The nobleman is fairly certain, however, that the people of his town drastically outnumber the shapeshifters by the manner of their tactics and time between incidents (no outright attacks, less than a half dozen shapeshifters involved in any one incident), and shapeshifters can be killed, restrained, or otherwise directly dealt with as easily as humans can, so there's hope. If kept days without food (about a week), the shapeshifter's form will begin to grow sloppy. Likewise corpses will slowly shift back to its gray, nebulous, humanoid form as they begin to rot. These methods can be used as an ultimate means of determining if a given being is human or creature, however neither of these methods are particularly practical. The town can't simply prove everyone is human and then lock themselves behind a wall, since the local industries of farming, logging, and mining are essential, and trade is conducted with the neighboring communities. The town needs some practical means of establishing a creature as human, or maintaining verification. Since appearances can be copied, a passphrase can leak or be tortured out, a physical token (like a badge) can be stolen, and (the most recent attempted method) tatoos can be copied (once discovered), it's difficult to solve this problem. What are possible policies the town can adopt to establish a being's identity, or maintaining verification? [Answer] # Dogs, Fasting, Passwords and Tokens Modern IT has a similar issue. It is generally handled by having a physical token and a user known password that changes regularly and is unique for each user and both are securely handed out. Add a kidnap password that includes a coded message of location(if known by kidnappee) and when the shapeshifters try to use it they can then be located and eliminated. A simplified example would be: Everything is fine password=EIFP Come save me I'm at the fork in the river= CSMIATFITR Make the physical token something that the person doesn't know themselves and that can't be tortured out of them. Eg while the person is asleep write a number in invisible ink on their back and check for it when the person gets back. The person doesn't know they are carrying it, doesn't know what it consists of, so they cannot compromise it under torture, nor could they tell the shapeshifters how to read it and duplicate it. There are plenty of these that were available in the middle ages, (eg lemon juice or alum) but the right one might be tricky. Also, a week isnt a particularly long time for humans to go without eating, so implement random week long fasts (It is the random-week-long-fast festival, we store food in the city granary, and prepare for the big feast!), control food going in and out and have your whole population watch for and report strange behavior. Use dogs to find illicit food. Additionally, being basically all medieval towns had dogs, dogs could be used to sniff out shapeshifters. If they don't have any scent dogs could tell that- which makes finding them in your population easy, and the scent of the items carried could still be followed to the nest, or if they adopt the scent of the person captured, the persons scent could easily be tracked back to the source and the whole nest eliminated, and dogs work in packs so (if they can take a dogs shape) a compromised one would not particularly matter. Dogs take care of the whole problem rather quickly, even just with the information given in the question dogs would wrap this up by following the scent on the clothes worn by a shapeshifter back to its nest (though if you had only one dog and it was compromised that would be a huge problem!) Beyond that, I could see a funny practical joke people play on each other develop. That is to call others "shifty" and get them a week living in luxury in a super comfy bed in jail fasting, reading books, and playing games. No reason to make it miserable if there is a good chance the person is normal. Finally, keep really good logs of where each person is, who comes in and out of the town, and always, always travel in groups. [Answer] It all depends on **how good the shapeshifting is**. Can a shapeshifter imitate something that a human would not be aware it is there - such as all the nuances of personal body smell that a trained dog might recognize? If not, then the answer is simple - employ guard dogs and train them to recognize shapeshifters. Their **density** could be different enough from a human's that they could be subject to [trial by water](https://en.wikipedia.org/wiki/Trial_by_ordeal#Cold_water). Their metabolism might be different enough, even in human form, that some substances (roots, berries, extracts of bark...) that are innocuous to a human are either lethal or have a discernible effect on shapeshifters, allowing to reinstate the practice of [corsned](https://en.wikipedia.org/wiki/Corsned). Are shapeshifters something alike *The Thing*, so that each part of their body is independent of others? If so, a drop of shapeshifter blood drawn from a finger will try to escape an approaching incandescent blade, and betray its nature. Is shapeshifter *matter* built the same way as human's? For example, is the smell of their hair, once burned, the same? Do shapeshifter react the same way as humans? Do they sneeze when inhaling pepper or when a feather is driven in their nose? Do they possess the [patellar reflex](https://en.wikipedia.org/wiki/Patellar_reflex)? Several tests could be devised and, possibly, those administering the test could be a sort of sacerdotal caste, living constantly protected to ensure they're not infiltrated; and they could *lie* about the test being administered, to throw the shapeshifters off the trail. They could for example tell people being tested that they've been given a secret drug that will make their eyes red-coloured, and shine a light in their eyes. What they're really testing for is the [human photopupillary reflexes](https://en.wikipedia.org/wiki/Pupillary_light_reflex). Then even if the shapeshifters succeed in abducting someone and torture out of him how shapeshifters are ferreted out, they won't be able to acquire a drug that doesn't even exist; and even if they *did* succeed in turning their eyes red upon inspection, that would only ensure they get caught. # If the shapeshifting is too good If the shapeshifters manage to emulate a human down to the cellular level, they will duplicate even complex things like sneezing without even thinking about it. Or if they're telepathic, they'll sooner or later work out how the tests have to work, and devise some way to thwart them. If this happens, we cannot tell human from shapeshifter from something that a person **is**, so we must use a different scheme of authentication - something the person **knows**. Organize people into groups that, while small, are larger than the standard shapeshifting patrol (just in case). The whole group must then undergo a week-long fasting; at the end we will know that they are not shapeshifters. This group will need to live together and swap stories. In a pretty short time, with the appropriate team spirit, each member of the group will know a quantity of things about every other member. Most importantly, the others will not be aware of *everything*, in detail, the other members know. And what they don't know cannot be tortured out of them. Nor can shapeshifters keep someone hidden for *weeks* while having him recount the story of his life, not even if they have truth-sense and can tell when they're being lied to. When in doubt, instead of having someone spout something that he knows, we *ask* him for something that he *ought* to know. > > "Hello back, Gayvyn! How was patrol today?" > > > "Boring and uneventful, Styvon, just as I like them!" > > > "Very good. So, what did Mariah tell you last Summer's Eve?" > > > "Duh, I don't remember. You sure you're not making this up?" > > > "I would? Like Eryk always does in the barracks, you mean?" > > > "Yeah, that." > > > "No, I did not. Unfortunately for you, neither did Eryk. *MEN, GET HIM!*" > > > [Answer] ## The only thing that can't be copied / stolen is the personnality. I'm pretty sure that if someone took my appearance, knew some basic things about me, and went back home, my companion would still notice. Even coworkers would still see that something is amiss, despite being a lot less close to me. In our world, this would be considered a weird behaviour, maybe worrying as it could be a symptom of a brain illness. But in your world... such small oddities would immediatly be recognised as a shapeshifter work. Some further investigations would be conducted, by asking personnal questions. You can torture someone to learn a password, or a few personnal things, but you can't learn all the shared memories, so a quick questionning by relatives should easily remove any doubt. As medieval communities were quite small, everyone knew... well... not everyone, but a least a large bunch of people in the city/village. Even the *guy nobody likes and who lives alone* is known, and a change in his behaviour would still be noted. An issue arise when dealing with complete strangers. When dealing with two parties not knowing each other (like in a trade between cities), a policy of traveling as a group of relatives to guarantee no one is a shapeshifter could be implemented. Of course this could be a *group of shapeshifters*, but since they're not so many, the risk would be reduced. And the more important the stake is, the more people should be requested. [Answer] **What happens if you set a shapeshifter (or portion thereof) on fire?** Will it begin to shift back as it burns? Will it be reduced to some sort of slag that is visibly different from charred human remains? I'm thinking, in particular, of hair, fingernails and other "expendable" bits of human anatomy. Cut off a lock of hair and burn it. If it burns like human hair, you're safe. If it melts into a grey amorphous slag, you're a shifter. [Answer] We are fortunate to live in an era where these sorts of security measures are actually rather commonplace. Everyone on the internet is a shapeshifter, if you think about it. I can think of two security measures from today's cyber world which are highly applicable in this environment. The first is defense in depth. You don't want to have just a single outer wall which "protects" everyone. That wall cannot protect everything to an acceptable level of satisfaction without simply quarantining everyone who comes in for a day or two. Instead, you rely on multiple layers of defense. The outer layers may have to deal with a few shapeshifters, in exchange for better commerce and access. Inner layers may accept more strict access restrictions in return for better guarantees. You're blessed to actually have a way of determining if someone is a shapeshifter or not. It's brutal, but it works. This means that you can have bastions which are certified shapeshifter free from which decrees can be issued. You might even develop a ritual for entering such a bastion which is proud enough to permit even a king to undergo a week of malnourshment. You'd simply want to make sure this doesn't have to happen all that often! The other key trick is one from identity verification. There's a famous trifecta for identity. An ideal identity verification requires three things: * Something you know (password) * Something you have (badge) * Something you are (biometrics) Inner sanctums may call for all three, but in the outer layers of your city, you probably wont be able to test biometrics all the time because the shapeshifters are good at mimicking those. Thus your outer sanctums would rely heavily on what you know and what you have. Decrees from the inner sanctums would likely rely on things you have. Someone descending from the sanctum would likely bring something like a holy seal along with them to validate their identity as one who came from the highly-verified non-shapesifter inner regions. Within the outer regions themselves, passwords would be popular and changed regularly. For travel between cities, spoilable visas may be very valuable. These would be documents verifying you as human (or more pedantically "most likely human'). These could be used to get access to outer regions quickly with minimum fuss. You would be expected to guard those visas more than your own life. They would be designed to be easily "spoilable," so that an attacking shapeshifter couldn't just steal your documents. This was the approach used for codes in WWII submarines. Codes were printed with water soluble ink, and it was expected that the officers would destroy the book by throwing it in the water if the sub was boarded. Fortunately for us, the cost of spoiling your visa wouldn't be all that dire. It would just subject you to more intense verification at your destination. Finally, its always fun to look at [Zero Knowledge Proofs](https://en.wikipedia.org/wiki/Zero-knowledge_proof). They're a fascinating form of verification which can be done along the lines of modern public key encryption. However, modern public key encryption is not tractable by human minds, so we can't really use it without computers. There are some interesting Zero Knowledge Proofs involving graphs, however, that are actually not that hard for the human mind to master. Some high ranking people may use these to provide a very hard to forage identity in the form of something they knew. [Answer] **A specialized Voight-Kampff test of cultural awareness**. (For the uninitiated: The movie *Bladerunner* deals with replicants, androids virtually identical to humans). People are talking with each other and the game is that you deliberately and inconspicously violate **one** specific social condition when you talk. Your counterpart then needs to refer to the specific violation and counter with a violation of its own. A shapeshifter cannot be aware of all the extremely complicated social interactions which are taught in human circles and subconsciously ingrained. Knight meets a farmer. Farmer: "Dear sir, may I invite you into my home". *(A knight may not be invited)*. Knight: "Peasant, I am pleased for your invitation. I want some bread". *(A knight never eats bread, it's low food)*. Farmer: "Unfortunately I have only capon, please do not punish me". *(Knights eat capon, after accepting hospitality they may not punish people)*. Knight: "I will punish as I please, peasant and if I lay my hand on your shoulder". *(A knight laying his hand of the shoulder is ambigous: It is referred by peasant as "He beats me", but for a knight it is a form of respect)*. **Pass**. Knight meets a farmer. Farmer: "Dear sir, may I invite you into my home". Knight: "Peasant, I am pleased for your invitation. I want some bread". Farmer: "I have everything ready for you. My wife has cooked a meal". *(Knight: ?)* Knight: "Very good, I am hungry. Do your wife also know how to prepare fish?" *(Today is Sunday. It is strictly prohibited for knights to eat fish at Sunday)*. Farmer: "Oh yes, incidentally my wife has also very fresh fish". Knight: (nods and lops head off with sword). **Fail**. The nice thing is that because both participants are changing their violations and invent them on the spot, you cannot predict what violation will occur. Even if the shapeshifters gain knowledge of the game, they cannot extract a lifetime of social conventions out of a person. [Answer] You mention that they shift "perfectly" into a human form. Technically, it can't be perfect, since a human can't shapeshift, so there must be some chemical / biological difference, particularly since the tissue reverts upon decay. Therefore, could a dog smell the difference ? Would a mosquito, a leech, or a flea drink a shapeshifter's blood ? If there was an outbreak of influenza, smallpox, measles etc. would the shapeshifters also be affected / infected ? Or are biological / medical techniques for telling them apart from humans ruled out ? [Answer] First, find people you're sure aren't shapeshifters (at the time). You mention that going without food for a week is sufficient to discern whether someone is a shapeshifter or not: thus, confine people in pairs (why pairs will become important later) for a week at a time, giving them only water. Possibly imbue this fasting with some religious or ritual significance. At the end of the week, if neither is a shapeshifter, they each tell each other a secret, but just as importantly, they'll have spent a week together in close-ish proximity and will have some idea of each other's habits: possibly enough to spot if a shapeshifter has taken their place. Either person may request this ritual be repeated when they suspect their counterpart is an impostor; given that it involves *both* parties being confined without food for a week, false accusations are unlikely to be due to malice. Additionally, this can be extended to larger groups or to multiple pairs of people when more trust is required: a village council, for instance, might do its most weighty decision-making while fasting this way: should one of their number turn out to be a shapeshifter, any input they had into the decisions that week can be isolated and filtered out. (Note: this is similar to theinvisibleduck's [answer](https://worldbuilding.stackexchange.com/a/82322/2808)) [Answer] There are a bunch of interesting answers already, but this is worldbuilding not riddle solving, so you are looking at this for a story or a game or something similar. Which means you **want** that there is such a way and are fishing for ideas. Well, what does the rest of your story require? How difficult should it be? Where is the tension? Is the identification of shapeshifters equally difficult, or are the means readily available to the lord, but hard to acquire for the common folks? The typical story-based solution is some allergy or unusual reaction to specific substances, typically ones that are not too common. Silver is a good choice in many stories because it is common enough to be encountered here and there, it is also rare enough that you don't typically have some with you when you travel in the woods. Food is another common option (garlic, etc.) and for variety you can have your shapeshifters have a **set** of food allergies, so the same test does not completely reliably identify all of them, but one of the tests always works. The requirement of having to eat or drink a certain quantity (half a bottle, not just one sip) before the allergy shows up would prevent the town folks from simply giving everyone all the tests all the time. There are all the other allergies, like sunlight, crosses, etc. that fiction invented. The thing is that this **class** of things that make the creature different from a human were invented for a reason - they work. They can be used in a story in different ways, they are flexible, they are not always reliable due to variations, etc. etc. --- Another common solution in fiction is that even with perfection, there is one thing that gives the creature away, and that is what makes it what it is. In your case, it is shapeshifting. If there is a way to **force** a shapeshifter to shift, that way just became your way to identify shapeshifters. Again, your story requirements determine what that way is. It might be dangerous or harmful to ensure it is only used after an initial suspicion. It might be costly or difficult to execute for similar reasons. But according to your initial assumption, the copy is perfect. If that is a strong requirement, then the only difference between original and copy is the ability to shapeshift and that has to be your token. Indeed, you already included this solution with the week-long-fasting. But why are you making it so difficult and then ask for an alternative? Re-think that condition. Water is more important than food, and the involuntary shifting might be induced after a day without water instead of a week without food. Again, this is worldbuilding so the solution should be **built** according to the requirements of your story, not some arbitrary preconditions. [Answer] * Arrange passwords, and tell the humans that they don't have to hold out forever if they are being interrogated, merely a day. Morning and evening roll calls where new passwords are given out. * Give each human an easily breakable token, and tell them to break it if they are in danger of capture. * Whenever a human must venture beyond *safety in numbers*, one of the stay-behinds does something very minor to their gear. A scratch on a belt buckle, a rip in the hem of a cloak. If possible something that will change if the victim is forced to undress, and which is too minor to be duplicated by the shapeshifters if they try to duplicate the gear. If the noble is an evil overlord, he might err on the side of caution and kill all **possibly** compromised underlings. A more reasonable ruler would let them hunger for a week, followed by a welcome-back-dinner. [Answer] I would rely on visual memory. Specifically, facial memory and picture memory. This is a kind of password system too, but a challenge instead of a personal password. Even in medieval times, we had art with superb likenesses and intricate artwork. So we have a gate keeper, and in his shack he has a thousand pictures of people's faces and various pieces of artwork that have their own names. (People can easily remember thousands of these, btw, when motivated to memorize them). To get into the village, get in a cage. The gate keeper will roll some dice to choose three drawings at random. They go in a frame; he flips it: Only you can see it: You have three seconds to name all three in order. If you fail on any one of the three, you remain locked in the cage, he calls security, and you are in for a very long fast; no second chance. If you are not a shifter, expect a few weeks of hard labor and remedial training. Do it thrice and you may not be allowed to leave the village anymore, or indeed be married and have children, because you are defective. Our gate keepers are kept under 24/7 protection and never leave the village, and we pick people with strong memories and very poor art skills, so even if captured they could not train the shifters to recognize the pictures or know the names of the villagers. And of course the gate keepers and guards are themselves tested every day before taking their post, by the guards of other gatekeepers: Everybody has to know the pictures. Duplicating the appearance of the human does not duplicate their memory, trained over many years to memorize these thousand images. The complexity and difficulty of that training make it too hard for the shapeshifters to hack. [Answer] # Use a personalized password, and prepare for emergency lockdowns. I actually support the idea of some sort of password - in this case, one unique to each person. Sure, it can be tortured out of them, but that's going to require some time. One does not simply walk into a town, kidnap someone, get the password from them, and then bring them back ten minutes later. It takes more time than that, generally. If a person is kidnapped, it will be known that they've been kidnapped. The victim will likely know after the fact, unless they've suffered amnesia, so if they should be able to sound the alarm when they return - not that it would necessarily do much good. However, the person's loved ones will know when that person is kidnapped, and they can tell the town's leaders. To ensure *that*, though, it is imperative that everyone stays with someone else at all times. No traveling alone, in the town or out of the town. **Any kidnapping shuts the town down.** Nobody outside is allowed back in, and if a person appears to be a known member of the town, they must be subjected to the intense quarantine required to prove that they are who they are. As you've said, attacks seem to be rare enough that such lockdowns should not be a regular issue. I'll also note that **redundancy is a virtue**. There's no reason you couldn't have a method of identification *and* a password, for instance. An inventive person might secretly hide their ID somewhere outside the town; even if they're kidnapped and have to give up the password, they'd still know where the ID is. [Answer] **If the town is small enough you could have a distributed trust system**, where you would have an identifying password with multiple people in town that is unique to that person. It might even be a common greeting, like greeting each person with a pet name that is unique to the relationship between the two of you. So I might call you Tiny, and Bob might call you Slim, and so on. And so if I came up to you and didn't greet you with the correct greeting then that would be a red flag. So you'd be justified in calling me out on it and getting a few other people with weapons to see if I know my nicknames for them. The changelings can probably torture a few passwords, but several hundred? Especially if I can also give some fakes out to trip them up? Much less likely. [Answer] Implement random imprisonment policy. Periodically, a random sample of people are imprisoned for a couple of weeks without food. The size of the sample depends on how many people you can take out of the society without significant impact. This will not guarantee that you weed out all shapeshifters, but forces them to take the chance. Additionally, whenever someone raises the suspicion that someone else is a shapeshifter, imprison the latter and keep an eye on the former. If the latter doesn't turn out to be a shapeshifter, imprisoned the former. --- Alternatively, if you have some substance that speeds the process, cut something like hair and see if it shifts back. --- As for personalized passwords - they are still applicable. Whenever someone is tortured, he can just give the reptilians a wrong password. They have no way to know if he is telling the truth other than use said password. If the password is wrong, the shapeshifter will die as well. Further torturing the person after this point is pointless. People will not believe a second John is John if they already captured and killed a shapeshifter that impersonated John. [Answer] Same one humanity has always used for this purpose: **Religion** and **Tradition** The amount of religions in the world with vast number of differences is absurd, and how often they ignore fairly obvious things about reality (like a religion that believes in a flat earth when we can fairly regularly see the shadow of the Earth on the moon). There's tendency to show that tendency towards religiousness is genetic, and the genetic advantage of it is obvious: Easy friend-foe recognition. As tribes became larger so you didn't know anyone by face, spies from opposing tribes could regularly be rooted out by them not following traditions, not knowing mantras, etc. Religions are -heavily- ingrained into societies, and often have a lot of nuance; and due to holidays, expected activity can shift radically in a single day. And religions have a tendency to quickly build up regional variations in larger society. It's not pretty, it's not friendly, but that's what humanity has throughout most of its evolutionary history used as friend-foe recognitition in lieu of familiar faces (and why we have such a problem with religious fighting and/or intolerance to this day. Literally ingrained into our DNA is the desire to be picky about religion as a survival mechanism.) [Answer] There have been some great answers already, but few would really be applicable to a traveller and usually require a tabulation of prior knowledge about a person. The shifters may appear physically identical, but that may not carry over to their bodily's autonomous functions. Reaction time and sleep requirements may be significantly different for a shifter, maybe they don't sweat when they're nervous (or at all), their body hair doesn't stand up when cold, they don't shiver or have a gag reflex. Perhaps their skin flushes in strange ways when they're hot or they can't eat certain foods (though anything that requires resources to administer might be too much for a small town). If you want some comic relief you could even oust people for a sudden lack (or feigned gain) of libido. These could all be tested fairly easily once a shifter has already been detained and even give a little leeway for a couple of shifters to make it through the tests and cause mischief if required for the plot. [Answer] In the center of the town, place a huge bank of strongboxes. There is a box for each person, with their name written on it. The boxes are locked, and the named person has the key to their box. In the box is a paper with a password written on it. To prove your identity, you must do three things: 1. Look like the person you are claiming to be. 2. Be able to open that person's box. 3. Know what is in that box. The process is simple. You go to the boxes, announce your name and the password, then give the key to an official who opens the box and verifies the password. Then you put a new (secret) password in the box, lock it, and you're done. This can also incorporate theinvisibleduck's suggestion of a "trap" password. You write two passwords every time: one means "it's me", the other means "it's not me, I'm an imposter stab me in the kidney". Once again, replace both passwords every time. [Answer] I honestly only read about halfway down the page. I did notice at least one person mentioned Leeches, and Blood, and a lot of people recommend Fire or cutting of Hair, but what if their Hair is a hazard to their Profession? (eg. Blacksmith, they work around Fire all day, they don't have any desire to catch their Head/Face on Fire, they Shave Both). One person mentioned Dogs, except we are forgetting in that aspect that we are dealing with something that can easily change it's shape, thus allowing it to not only have the advantage of being more intelligent than the Dogs and their Owners, but it could also easily Overpower even the most ferocious of Wolves, as it could simply transform into a Jaguar and easily take out 5 Dogs without issue, at which point it could simply gather 5 other Shapeshifters and now there's a Pack of "Dogs" roaming the Town desiring to cause Chaos in any forms they can manage, such as alerting the Townspeople that their beloved Mayor is a Shapeshifter all of a sudden. Gee I wonder when that happened? Answer: it never did happen, the Shapeshifters learned the Dog's behavior once the Dog reacted to it, and then spread that information to it's "Pack", and because there's so many of them, the Dogs wouldn't dare approach, as even animals such as Dogs know when they're out numbered (think: Han Solo chasing Storm Troopers into their Ambush where he promptly Flees). * My suggestion was to start with **Leeches** to induce **Bleeding** as they produce an **Anticoagulant**, then comparing the **Blood Color** (which would most likely be Red due to the Shapeshifter's studies of Humans). Note, the Bold items in the above Paragraph are all potential differentials, meaning they could all possibly have a different reaction between Humans and Shapeshifters, and would need to be documented. * The next testing would be to compare certain effects such as **Fire** (used in *The Thing* to *Combat* The Thing as it couldn't withstand Extremely High temperatures for very long and would suffer from Cellular Break Down, but they *didn't* just randomly start *burning people*, they had a **Test**, if the Glass Shattered, they were Infected, and *THEN* they were killed, but *not* before the Truth was revealed, **this** question is asking to provide a **New Test** *besides* Starvation). * The next Effect would be **Ice**, which was easily accessible in the Medieval Era as they had a good Knowledge of Permafrost locations and kept ample storage of Ice in the local Ice Sheds for Refrigeration of their Food supplies, the Ice would also be readily available from the various Traders, because it's an in-demand resource no matter what Town they Travel to (unless it's an Exporter of Ice, at which point the Traders would Stock up, both for Resale and for Personal Storage) The Ice would be compared to both the **Blood Sample** and the **Individual in question** (Nerve Reflex? Shivering? Shuddering? Reflexive Reaction? {the "EEK!" factor} etc.) * The next test would actually be quite a bit more pleasant to Test, to a certain extent: **Toxins**! Beginning with Fermented Grains (**Ales**/**Beers**), then Fermented Berries (**Wines**). I'm sure that quite a few citizens would know each other's **Drinking Habits**, seeing as it's the most common **Disinfectant** available, and it's got quite the large **Recreational** use amongst the population ("Bob, you're such a Lightweight! only **2 Pints**?! this is my **7th**! Bwahahaha!" one day, Bob suddenly can drink 10 Pints and is barely Bubbly *Something is amiss...*) * The reason I said toxins would be *somewhat* pleasant is the next Test, **Allergies**! Quite a few humans have very common Allergies (Poison Ivy, Poison Oak, certain Mushrooms are even Lethal, etc.) but some aren't allergic to the common Allergies, whilst others are Allergic to almost everything they can think of (Dust, Pollen, various Cloths and Animals, I for example have an Allergic Skin Reaction to Pigs, but a Shapeshifter wouldn't realize that until the Rancher had already gathered a Militia). * There's also the power of **Misinformation**, one could convince every towns-person that they've been branded with their own unique number, and they are even able to know the Number, but instead of **Branding** everyone, you simply **Heat** the Metal, so as to *feel* hot, but not hot enough to actually *Scar* them like is preformed in Branding. The same sample comparisons (eg. Fire, Ice, Toxins, etc.) could also be preformed upon any Hair Samples that can be acquired. I hope I have created a rather comprehensive gauntlet of tests and that potentially at least one of these becomes highly successful for the Townspeople, as these Shapeshifters they're dealing with are giving the peaceful varieties a bad reputation. Edit: a few other Posts reminded me of the Tactic used by a few rather intelligent Villages that were once under siege by a mythical being of some type or another (and in one instance: the Dhampir known as **Blade, the Vampire Hunter**) where they Laced the Food and Drinks with a Toxic Substance that didn't affect the regulars. (Blade isn't affected by Holy Water, it's even in his Tap Water, there's also stories of Silver in Water Supplies to ward off Vampires as that would make every house a place containing a Water that "burns" {like Holy Water} the Vampires, and also prevent them from "blending in") [Answer] In an episode Star Trek: DS9, Changlings have infiltrated Earth. In response, the security services take blood samples from everyone. If it was a from Changling then it revert to Changling's silver liquid form after a few seconds. Your town's inhabitants could do they same, and terminate with extreme prejudice anyone who fails. However, it is possible that the blood sample is held by another shape-shifter then it will stay looking like blood. [Answer] Because of the law of conservation of mass, shapeshifters cannot change their weight. I would recomend: 1. making sure that noone in the village is a shifter (the hunger test doesn't have to be done at the same time for all the villagers, so a part of them can always work) and 2. everyday weighting all of the villagers. Their weight cannot change too much in a one day, so any big differences between weightings would give the shapeshifter away. You could also just ask a lot of questions and observe the behavior carefully. It's actually much more safe option than a password - remembering all the things that one person should know is much more difficult than remembering a word or two. Shifties could observe that John Smith is hard-working and his wife is named Mary, but they don't know his whole history, which will be painfully obvious after closer examination. Even a dumbass will know that something is wrong if "John" will hesitate to state the name of his dead blacksmithing master, whom he bragged about that much last summer - and report it to the authorities. Boom, hunger test. His wife for sure will see that he shouldn't be so enthusiastic about spinach or that he suddenly doesn't need coffee. And, of course, shapeshifters could not do any job requiring a lot of experience that they don't have - so specialists (or just people knowing a bit about their jobs) would be safe. The experience part also helps you in checking the guests - specialists who can do their job well are nearly for sure humans, non-specialists can just take some personal history tests ("What was your favourite childhood toy?" - good answers: "A doll" "Does a broom count?", bad answers: "Eeeeeee... ball?" "A sword" - told by a guy claiming to be a normal peasant; and a lot more of these). Seriously, this shapeshifter couldn't think every detail through, couldn't know everything about local customs, and it will be seen. Also, as said before, fake questions. This would be easy as pie in a small, closed rural town, where everywhere knows dach other. [Answer] For what it's worth, I just read a book (*Faded Steel Heat*, by Glen Cook) where shapeshifters were involved and identifying them was crucial. In that case, the shapeshifters had a bad reaction when touching silver (think werewolves and vampires and such). If your shapeshifters had what amounted to an allergic reaction of some sort to some relatively common substance (iron, vanilla, dandelion fluff, whatever), then it would be easy to identify potential shapeshifters; the longer term methods to confirm identity (fasting) could be applied. It would royally suck to not be a shapeshifter and have that same allergy, but it would be survivable; stick around home, and use the "buddy" system so that one or more people without the allergy never let you our of their sight, and you might even be able to live an almost normal life. Yes, this does involve something not accounted for in the original question, and isn't necessarily as elegant as the "have the shapeshifters not be able to match a human scent, thus being detectable by smell" (and in fact, that was used in the story I just read as well; shapeshifters didn't smell like humans, and could be tracked that way), but it could make for some interesting twists on the economy of your world (whatever shifters were allergic to would tend to be somewhat valuable, because it would be in everything - buildings, clothes, maybe food, etc), and could make for some interesting moments ("What do you mean he burned down the dandelion patch!?") [Answer] Why not simply have the shapeshifter smell a little different to humans? Not pungent, but just enough that a careful close-up sniffing reveals that they are different to humans - especially humans with medieval hygiene. [Answer] A simple method would be to use long-range light based semaphores (the semaphores would be a sealed system, with only quarantined access) that send a piece of identifiable information that the individual should know. The information is sent by a 3rd party via the semaphore using a shifting cypher known only to the individuals within the semaphore towers. This information would be sent by one who knows the person, but has not informed them what information they are sending. This system would also setup the background to which the tales of the elves would be able to come in (stealing babies and replacing them) as then they would have 'inside men' growing up knowing the others in their village/town. It also allows for the very serious problem of what happens to loners and outcasts. [Answer] This sounds like a game of [Werewolf](https://www.playwerewolf.co/rules/ "Werewolf") only without someone in the Seer role. As such, you could have regular accusation sessions, and watch for the differences in psychology at work. People are slower when lying or having to invent answers, than they are with telling the truth, so a simple "Raise your hand if you're townsfolk" gives you a nice starting point. The longer it goes on, the ones with secrets get more and more impatient. You could see damage limitation strategies appearing, too. Redundancy through separation - it's much harder for an infiltrator to damage the food supply if you have many small grain stores, and it's harder to sabotage weapons or steal jewels if they're kept split up in several places. If only a small number of people had access to barn number 6 and something happened there, it increases the chances of you discovering the shapeshifter. This also makes it easier to use a [honeypot](https://en.wikipedia.org/wiki/Honeypot_(computing)) or some other form of tempting target to ensnare infiltrators or encourage them to perform hasty actions. [Answer] Take a ~~pistol~~ Blade and point it at the suspected doppelganger. Calmly but firmly threaten it with death unless it shows itself. Then wing it. If you wound it and it still acts like a person then you're nuts and there was no shape shifter. Discretion won't win the day here, you have to be almost recklessly decisive. Edit: P. S. It is also helpful to offer an Edit to assist them further. But that is still accurate, Violence wouldn't solve anything long term and would only cause distrust amongst the population we are trying to keep safe. Still a very good first try. [Answer] There's a fairly simple way to solve this. Each person leaving the town deposits a token of some sort. After they have left, the token is given an ID and the ID is written next to their name. The token must be an everyday object and all tokens must be of the same type. The token must be sufficiently familiar to be able to be identified on return, while being sufficiently similar to all the others to be almost impossible to describe such that someone else could identify it from the description. When you return, you idnetify your token, and give the guard the ID and your name. If they match you enter, if not, you sit in a cell for a week. Tokens could be a piece of wood, or a lumpy stone where you would be able to remember something about the grain or the lumps, though here you would need to make sure people trained in remembering their token. What's important is that the token is easily identifiable, but in ways that are almost impossible to communicate. For added security, you could multiply the number of tokens required. [Answer] **Give 'em a haircut** If the shapeshifters turn grey and gooey soon after death or after fasting, what happens to their hair after it's cut ? So getting a haircut becomes a regular community event, they make a party out of it. Maybe a weekly get together. The hair is stored in jars with each persons name on it and the jars are kept locked and guarded. The jars are inspected twice a day by the town barber / sheriff and anyone who's hair has gone gooey gets a rather more violent and permanent haircut very shortly afterwards. If someone's bald, give them a manicure. ]

[Question] [ I'm trying to come up with a flag for a fantasy city I'm designing, and it got me thinking about how flags are designed in general and where they draw their inspirations from. For the most part, I believe that most flags are simply based on cultural/regional sources. Like for instance, the flag of a christian nation might have a cross on it, but a flag from a buddhist would not (probably). Looking at the flags of the Earth (national, regional, municipal), there are countless designs. Some are abstract, some depict very detailed imagery. Some have only a few colours, some have an enormous colour palette. Some have animals, some have objects, some have people. Also the process of creating a flag can also be very different. Just last year New Zealand held a national contest where any citizen could send in a design for a new flag, then a government committee would pick the best 50 and hold a public vote. I'm sure other countries have simply called in a designer and got them to design a flag and damn what the people think! So my question to any vexillologist in the forum, are there any particular rules or guidelines for the inspirational source of a flag's design, or is it completely open to the designer's imagination? [Answer] From the excellent article titled [The 5 Basic Principles of Flag Design](http://www.hamblywoolley.com/about/articles/the_5_basic_principles_of_flag_design): > > While not rules, there are 5 basic principles. > > > 1. **Keep it Simple**: A flag, they say, should be so simple that a child > can draw it from memory. Kids will have fun drawing Japan’s flag, > but not so much fun with Turkmenistan’s elaborate carpet-like > patterns. > 2. **Use Meaningful Symbolism**: A Star of David in Israel’s flag carries > great meaning; however, the symbol of the rifle found on > Mozambique’s flag may not be the most positive icon to represent a > country. > 3. **Use Two to Three Basic Colours**: Most flags get this right. Clearly > South Africa didn’t get this memo — it has six colours on its flag. > 4. **No Lettering or Seals**: Mexico has incorporated an extremely > complicated seal into its flag — an eagle holding a serpent, perched > atop a prickly pear cactus, atop a rock that hovers over a lake. Try > drawing that, kids. > 5. **Be Distinctive or Be Related**: I understand why the Scandinavian > flags are part of a family, but Australia and New Zealand’s flags > are virtually identical. > > > [Answer] ## There are no hard and fast rules … There will always be outliers. The [national Flag of Nepal](https://en.wikipedia.org/wiki/Flag_of_Nepal) is rather unique: [](https://i.stack.imgur.com/EA7Nc.png) In fact, to construct it accurately requires **24 complex steps.** [Here's a video](https://youtu.be/f2Gne3UHKHs) with mathematician Dr. James Grime following those steps to draw the flag. ## … but there are guidelines Obviously, many national, regional, and municipal flags are rather similar in appearance, as you noted in your question. ### Aspect ratio Or simply, the ratio of length to width. Wikipedia outlines the most common [aspect ratios of national flags](https://en.wikipedia.org/wiki/List_of_aspect_ratios_of_national_flags), of which there are a great many, but the largest groups of flags are either: * 2:3 (1.5), including Japan, France, Russia, and many more, or * 1:2 (2), including the US, Canada, United Kingdom, and many more, plus * a handful of others in use by a few countries ### Colors Virtually all flags use **solid colors.** You aren't likely to find gradients or shading on any government flags (if anyone's aware of a real counter-example, I'd be interested to see it, although these would certainly be outliers, regardless). ### Symbolism Some flags have symbolism, such as the "sun mark" on Japan's flag, maple leaf on Canada's flag, stars and stripes on the US flag (representing the States), while some flags adopt a simpler design, such as a tricolour design. Those are your two basic options (symbolic or not), but within them, the possibilities are nearly endless. ## Creative inspirations The first search result that popped up for me for a "flag design" search is the excellent [The 5 Basic Principles of Flag Design](http://www.hamblywoolley.com/about/articles/the_5_basic_principles_of_flag_design) by Hambly Woolley (a design firm). TrEs-2b referenced it as well, and has already quoted the five principles (summary) in his answer, so I'll simply refer you to the rest of the article, as it is very good. I'd also suggest doing a [Google Image Search for flag design](https://www.google.ca/search?q=flag+designs&safe=active&tbm=isch), which will get you a lot of real flags, as well as flags designed for fantasy, corporate flags, and pretty much everything else. [Answer] You might also be interested in the 99% Invisible podcasts and articles on flag designs at <http://99percentinvisible.org/episode/episode-06-99-symbolic/> and <http://99percentinvisible.org/episode/vexillonaire/> Excerpt: > > Here’s a trick: if you want to design a kickass flag, start by drawing > a one-by-one-and-a half inch rectangle on a piece of paper. > > > A design at these dimensions held 15 inches from your eye looks about > the same as a three-by-five foot flag on a flagpole a hundred feet > away. > > > [Answer] European national flags arise form heraldic tradition of armory (study of coats of arms) and are a quite new development. Similar ideas have been seen in other parts of the world hence the flag of nepal which comes from their own tribal markings. The key concept of armory is that there is a limited color palette and symbols have a set form. The reason for this is that production methods in the medieval times were not standardized like today. So a logo like Coca Cola that is always printed in the nearly spot on same red color could not have been achieved back in the day. Same applies to shapes as they are hand drawn. So as a results the colors and iconography are symbolic. * All hues of red is still just the same red color. * All Circles are the same circle eve if the size changes slightly. * Shapes are simple, or at least a intricate shape is equal to simple one just as long as it has all elements in the description. ## Rough European heraldic rules There are some rules to the use of patterns and color so that the coat of arms or flag *can be described with words* and are identifiable in the heat of combat. Preferably even when soiled with gore or years of sunlight exposure. Europeans have traditionally limited themselves to colors: * Black – Sable * Green – Vert * Blue – Azure * Red – Gules * Purple – Purpure * Maroon / Blood Red – Sanguine / Murray. * Orange – Tenne / Tawny In addition to colors you have two metals: * Silver substituted by the color White – Argent * Gold substituted by the color Yellow – Or And furs which are basically patterns on the color. All of these are together called tinctures. As a rule of thumb you should never adjoin two colors, but you should have a metal in between (though sometimes black is allowed to do so, and if there is a symbol on top it has its own rules). Also your base coat of arms should be limited to one metal (and one fur). If you look at European flags most follow this rule see: * wikipedia on [flags of Europe](https://en.wikipedia.org/wiki/Flags_of_Europe), the older the flag the more closely it follows this. So take the Finnish flag, it is an Azure cross on silver (with some measurements for the proportions). The exact blue is not specified which is why you see some variation in the blue even so most Finns aren't aware of this fact and this may lead to heated discussions if asked. But there are more modern rules that say more stringent, but even with wrong blue its still the Finnish flag. Same kinds of rules apply to pennants and banners. Sometimes it seems that these rules are more like what they call guidelines. ## Other traditions Other traditions exist and have somewhat similar rules. Its good to look at Japanese and Chinese heraldic banners and clothes for further ideas. This might also explain why the newer countries may have a more modern or more local interpretation of the rules. So maybe South Africa did get the memo but decided to use more local traditional interpretation of the rules! ## Go forth and set your own rules In your own world you can use whatever rules you want. But best limit to simple. It also makes written description easier. [Answer] What time period your world is set in? You might want to research the flags of the our world states of the similar era. How old is your flag? The designs of the symbols of state (flag, crest) often have tendency to stay unchanged for centuries. Once again, research the era similar to that in your world's history, when the flag first came to existence. As for slew of advices already given about styling a flag, there is one important thing to remember: historically, a flag or a banner was raised to distinguish your warriors from enemy combatants. That was (and still is) its primary purpose. This is why a clearly recognizable combination of prominent solid colors is prevalent in the designs of most flags. This way a flag serves it purpose instantly, whether it is raised over a castle, man-o-war, or just picked up and held high by a single soldier. The heraldic symbols (if you wish to employ those) are where you have most fun. There is no stopping your imagination in that. Historically they usually depict or hint at some heroic or otherwise important events in the history of the state/city. The rest is up to you. That includes the aspect ratio :-) [Answer] The important thing is to consider the function of a flag. A flag is a flexible, piece of fabric that is suspended in the air to use as a form of identification or communication at at distance. So, a flag needs to be recognizable, and it needs to be so when suspended in the air, potentially wrinkled upon itself to some degree, and at a distance where fine detail is not going to be visible. It might also be seen from either side. The "Rule of Tincture" from European heraldry is a rule of thumb for making high visibility colour combinations and could be generalized to "contrast light with dark". It's not about following the rules for the rules sake, it's about making the flag effective. A few similar "rules" would be to try to have boundaries between contrasting colours extending to the edges of the flag. This helps make the flag recognizable even if it's hanging limp without much wind. Don't use fine details to distinguish your flag. They won't be visible at a distance or if the flag is moving or limp Don't just drop a symbol like a seal or coat of arms in the middle of a solid coloured field (US State Flag Syndrome). Derivatives of red and blue ensigns (Australia, New Zealand, Ontario, Manitoba, etc) are another bad example. An alternative is to do a heraldic banner where you take your coat of arms and expand the shield into a flag. (The flag of British Columbia was created this way for instance) Don't make the back and front of the flag different. A few flags have distinct back and front designs and this is a horrible idea. The point of a flag is to be recognized so having it be different depending on the side you look at is counterproductive. It's also difficult to make a flag that's different on opposite sides without making it either "bleed through from one side to the other" or be too heavy to fly properly. The flag should work when mirrored. The back of the flag is actually a mirror image of the front. The US flag has the blue canton with stars at the left on the front, and at the right on the back. Think in terms of toward/away from the flag pole instead. Don't include text. Text is fine detail that doesn't work when mirrored. Consider other flags being used and aim to be recognizably different. Don't be like Australia and New Zealand (Which one has the extra star and which has the stars trimmed in red?), Ontario and Manitoba (Does the little tiny coat of arms have a sprig of maple leaves or a bison?), The Netherlands and Luxembourg (What shade of blue is that?), or most of the US states (So it's some sort of circular seal on a blue background) Of course, that all depends on whether you are trying to come up with good flags. There are obviously a lot of bad flags in real life, so you might want to make intentionally bad flags. Modern flags tend to be fairly symbolic so they can survive being poorly designed. Historically their function was more important so simple bold recognizable designs would have been preferred. [Answer] Flag design is an interesting topic, which has been popularized recently by Ted Kay’s *[Good Flag, Bad Flag](http://www.metisnation.org/media/376268/gfbf_final_web.pdf)* and Roman Mars’s TED Talk “[Why city flags may be the worst-designed thing you’ve never noticed](https://www.ted.com/talks/roman_mars_why_city_flags_may_be_the_worst_designed_thing_you_ve_never_noticed?language=en)”. However, there is more to say than that. They are good places to start, but follow them up with Perry Dane’s *[Flags in Context](https://www.pdcnet.org/85257D7A006284F7/file/E00E3EA3FAC0FFFAC1257DCC0069183B/$FILE/raven_2008_0015_0000_0045_0082.pdf)*, which discusses the history and aesthetics of vexillology in far more detail. Possibly also pop into [/r/vexillology](https://www.reddit.com/r/vexillology/). Flags can be sorted into various categories. * Most of the older flags have their origin in heraldry. Heraldry itself, of course, is a purely European tradition. Other cultures have had rough equivalents, but heraldry is European, as are the oldest flags. The oldest national flag still used is that of [Denmark](http://www.guinnessworldrecords.com/world-records/oldest-continuously-used-national-flag/). The Scandinavian cross is also used on the national flag of many of Denmark’s neighbours. * Tricolours, when they originated, were bold and simple and new. Visually striking. Newer tricolours are less powerful. Also, they are somewhat boring. (Personally, I wish Ireland had retained the harp. It’s a heraldic symbol of Ireland, and is very distinctive.) * Newer national flags are striking out in different ways, discarding the heraldic past. * US State flags have a genre all of their own: *seal on a bedsheet*. Avoid. And others (read Perry Dane for details). --- In a worldbuilding context, you have to think about what you’re trying to symbolize with your flag, and about the design tradition in which it resides. Does it come from an older aesthetic tradition, such as heraldry? If so, what does heraldry look like in your world? In our world, tricolours have a specific meaning. A tricolour means *this country is a Republic*. There are other traditions in flag design, such as the pan-African colours seen in many (but not all) African national flags. Similarly, you might be better off not designing *one* flag, but designing a *family* of flags, in conversation with each other. Work out their histories, and which came first. Flags change, as a result of governmental changes. Many national symbols started out as family or personal symbols of a ruler. When there’s a revolution or coup, the symbols can change (or can merge). --- Symbols matter. When the Irish Free State started minting their own coins, there was massive controversy. The Free State was no longer part of the United Kingdom, but at the time still recognized the British Monarch as Head of State. And yet they minted coins with just a heraldic harp, not a heraldic *crowned harp*. Some people saw this as disrespectful. Perhaps it presaged Ireland’s eventual exit from the British Commonwealth of Nations and declaration of itself as a full Republic with an elected president as Head of State. [Answer] I would like to just emphasize: *It is really your decision.* Yes, it holds countless advantages to stay in line with principles, but basically **a flag speaks for its bearers**. If it depicts a community which is totally careless about the standards that others converge to, then so be it. You can read plenty about common thoughts and views about how to design a flag, but it’s up to you. **For a fantasy city:** Since it is in your world, you may want to follow your rules. Once I happened to design a flag for a Dungeons and Dragons 3.5 city, showing clear communication that they are employing mercenaries for statarial and swift peacekeeping. The only aspects I had to go with is the communication style of the adventuring party and the baselines of the city. The party can still get lost in understanding the elements. So it is up to what the city wants to communicate and how. [Answer] There is a fantastic TED talk regarding Vexillology that perfectly answers most of your queries. In this surprising and hilarious talk about vexillology — the study of flags — Mr. Roman Mars reveals the five basic principles of flag design and shows why he believes they can be applied to just about anything. Please watch this: [Roman Mars — Why city flags may be the worst designed thing you’ve never noticed](https://www.ted.com/talks/roman_mars_why_city_flags_may_be_the_worst_designed_thing_you_ve_never_noticed?language=en#t-1075820). [Answer] My own conworld has its own heraldic rules. Those are: 1. Colours for lines are sables, silver, gold; 2. Colours for fields are goles, blau (blue), jaune (yellow), sinople, orange, violet, sables and snow (white); 3. Any two fields must be separated by at least one line; 4. Sables, violet, and blau fields reject sable lines; 5. Orange, jaune, goles, and snow fields reject golden lines; 6. Jaune and snow fields reject silver lines; 7. Clerical heraldry must limit itself to sinople, orange, violet, sables and snow fields, and requires fields of at least one of the three first colours; 8. Noble heraldry may use fields of any colour. but not both goles and orange, blau and violet, or jaune and snow; 9. Commoner heraldry **must** violate at least one of the rules above. I probably had more fun designing that set of rules than any of the individual flags I managed to come up with. Flag of Sinian (one of the fifteen kingdoms, or major States): [](https://i.stack.imgur.com/zrLFs.jpg) [Answer] As alluded to in other answers it would be well worth looking at the rules of heraldry. In the UK and Commonwealth this is regulated by the [College of Arms](http://www.college-of-arms.gov.uk/) and their website (in the link) has quite a lot of interesting information on the subject. These rules, in practical terms are designed to produce arms which are recognisable and distinctive to an individual/organisation. In more general terms the basic principal of the graphic design of logos and trademarks etc will apply and indeed modern trademark law is a close analogy for medieval heraldry, serving a very similar purpose. A key thing is that a flag needs to be simple and distinctive enough that it can be recognised at a distance in a range of scales and formats as well as being reasonably easy to reproduce. So typically you are looking at * bold geometric or stylised shapes * a limited palette of contrasting colours * limited fine detail, or at least a design which still works with fine detail removed. There are designs which do have a lot of detail and small text etc such as [regimental colours](http://www.thamesweb.co.uk/windsor/castle/images/bathon450.jpg), but usually this is overlaid on a much simpler design which is dominates the overall scheme. ]

[Question] [ ## The Setup A while back, I read an article in which the author compared the rise and fall of civilizations in the universe to a forest. In the forest, small plants come into being, grow, and die over relatively short time spans. Living in the shadows of much larger trees, these small plants compete with one another for the basic resources of life: sunlight, water, and carbon. The large trees, on the other hand, tower over the forest floor and have, compared to the smaller plants, an unlimited supply of resources. The forest, then, is a hierarchical ecosystem dominated by the ancient, firmly established trees, in which the smaller plants (and smaller trees) are just sort of along for the ride. When one walks into Redwood National Forest, after all, he most likely notices all the giant trees before noticing the shrubbery. (I wouldn't know for sure, as I've never been. It's on my List). Similarly, the Universe is teeming with many small civilizations that continually rise and fall over the course of millennia... but only a relatively few civilizations that have reached the top of the Foodchain (capital 'F'). My story concerns such a civilization... let's call them the Foo for lack of a better name, as I'm a computer programmer by trade, and some habits die hard. Let's say that, by our reckoning, the Foo are at level somewhere between III and IV on the [Kardashev scale](https://en.wikipedia.org/wiki/Kardashev_scale), and have the agency to effect change on a universal scale. These people built and abandoned Dyson spheres long ago. They have engaged in stellar architecture, creating both the art and the engines of their economy with the very stars themselves. Now, they are well into the age of galactic engineering. They have intimate knowledge of the nature of reality itself, hard won over countless mega-years of evolution. Now, though, the Foo have a Problem. ## The Problem Spoiler alert: I do not know what the Problem is. Perhaps it is the impending heat death of the Universe. Perhaps it is something utterly alien to my own limited understanding. I just don't know. **This is the specific question for which I am currently seeking guidance.** ## The Out of the Box Solution All of this, I must confess, is to serve as the backdrop for the story I really want to tell. The Foo, you see, facing an existential threat whose solution lies beyond their own understanding, must seek an "out of the box solution." Well, perhaps it would be more precise to say that the Foo have decided to seek an "inside of the box solution." Being so keenly self-aware has given the Foo an insight that just might save them: **they realize that they have reached the limits of knowledge they are capable of obtaining from within the context of their own experience**. They understand that, although they are nearly omnipotent, they are still bound by the "baggage" they carry from the previous stages of their evolution. Without outside help, there will always be questions for which they lack the proper context to answer (or even know to ask). As it happens, the Foo have decided to devote their entire economy to constructing a full scale [simulated reality](https://en.wikipedia.org/wiki/Simulated_reality) of a new universe, simulated at the quantum level in full fidelity. Their goal is to monitor the evolution of all of the civilizations that arise therein, observing them through all the various stages of evolution until they discover one with the potential of solving their own particular Problem. Although this concept is ripe for further questions and discussion (what is the substrate of this simulation? What is the level of precision? How can they possibly assimilate all that data? What if the Foo are already in a simulation? How does time pass in the simulated reality compared to the Foo's reality?), I really just want to focus on the nature of the Problem for now. The other stuff will come as this idea germinates. Thank you for your time. I very much look forward to joining your community. [Answer] The easiest Problem to deal with is quite simple: **they're wrong**. A civilization like that presumably has some direction they believe they are going along. They're hopefully not just wandering aimlessly among the stars, using up the full energy of a galaxy here and there. They have to have some plan that's guiding them. What if that plan is wrong? What if they commit to the path, and then use up so much energy that when they realize that path will never take them to where they want to go, its too late. For most of us humans, there's plenty of energy to drown our past sorrows, and regain balance. For a nearly class IV civilization, that sort of wasteful use of energy is much harder to come by. This would cause them to rethink everything, and potentially allocate some of their precious energy to simulations to try to rethink their plans. Most importantly, however, it has to be something they missed. That means they will *want* to have little unknowns creep into their system, offering clever solutions that the Foo could never think of on a cosmic scale. If you want inspiration, watch any movie where there is a bad guy who realized he was going down the wrong path, but went so far that he feels he can never possibly come back. The TV series Blacklist has one such character. They know the solution isn't in their power, so all they can do is do their best to empower others, and see if they can get lucky and find salvation on the way. [Answer] # Isolation and collapse to Kardashev Level 2 Civilization If current theories about the Universe, Dark Matter, and Dark Energy are correct; then we're beginning a period of ever increasing acceleration of objects away from each other. What this means is in the future, galaxies accelerate away from us so that they fall outside our light-cone. Eventually we won't see galaxies outside of our own ever again. Similarly if the Universal Expansion continues, then the stars within our galaxy will begin accelerating away from each other. First, imperceptibly and later at ever increasing accelerations. How do you remain a Kardashev III+ civilization without a galaxy's worth of resources to tap into? What they see is sometime in their future there will be a collapse of their civilization to a primitive Kardashev level II civilization. If we on Earth would find a civilization collapse difficult, how might a galaxy spanning civilization view its shattering into and isolation of its constituent stellar systems? [Answer] ## Stagnation An understanding that as they're no longer challenged they're no longer changing. As they're no longer changing, they're no longer evolving. Like the old tree, their civilisation is rotting from the inside out and will in due time collapse under its own weight, leaving the space for the smaller civilisations to take their place in the universe. They consider themselves to be the best and the brightest but the only thing they can think of to do is the same as every other primitive civilisation. Namely sex and drugs and rock and roll. The civilisation has lost its direction, they're not developing new technologies because there's no reason to. Nobody can think of anything that they can't already do or a reason to do it. Revolutions are for young people with short lives, near immortals who are already old can't change. The whole operation is probably effectively a gerontocracy already, they need a revolution and they can't have one. [Answer] The Foo are, simply, boring. Extending the forest analogy, the Foo are the towering redwoods, the biggest, best thing around. As time goes on, the trees just keep growing; while at first they reach towards the heavens, eons later they are surrounding entire suns to capture the energy. A Dyson sphere, after all, is at its soul merely a really efficient tree - using the energy of the sun to grow. The Foo continue to evolve, but the pressure for evolution isn't the base survival of the bushes and plants of the forest floor; it's simply that they need to be big enough to live forever. While tiny plants must do all sorts of tricky things to survive, the big trees ignore them entirely. They are neither fast nor curious. Inventions come through working through all possible methods of moving from point A to point B; iterative design gives perfect results if you keep working for a thousand years. The Foo aren't apex predators; they only need light and heat to survive. They don't hunt. They may not even forage. They live for thousands, maybe even millions of years. The dead rocky worlds they expanded to, have been terraformed into mild, pleasant city-worlds, populated with a people whose single-minded goal is to live forever, as efficiently as possible. It's not that they haven't discovered war, or other sentient life; it's that wars are over so quickly, and sentient life dies out so fast, that they never really even notice them. Like redwoods ignoring a wolf, the Foo don't even register other races as anything more than *present*. And then they walk into the **Bar** (sorry, couldn't resist). The Bar are a war machine, burning planets and harvesting the energy, eating everything they can. They are the Spinosaurus, the Great White Shark, and the polar bear, all wrapped up in one: the ultimate apex predator. Now, trees are efficient; they don't need to be a thousand feet taller than their neighbor to get the most sun, just a few inches. Predators, however, go overboard. A polar bear doesn't need to be as big as it is to catch a few fish; that might be what it chooses to eat today, but only because it's so big it can eat *anything it wants*. Suddenly, the mighty trees are threatened by a species willing to *torch a forest to eat some squirrels*. A species that is inefficient, overpowered, and hungry. The Bar are willing to destroy anything to get the resources they need, and that includes the Foo. Like trees versus a T-Rex with flamethrower arms, they are bewildered and frightened. They can't wait a thousand years to iterate over the designs for a plan to fend off the Bar; they need a solution now. They don't have the imagination to even realize what they could use to protect themselves; the usual choices are "grow taller" and "grow thicker bark", neither of which can be done quickly. Even in the most dire situations of their past, facing fire, pests, and famine, the Foo only needed to be strong enough to weather through. Now, survival may not even be an option. The actual problem may not be directly related to their own, immediate death; it may be that the Bar are testing technology capable of ending the universe, or preying on the life forms that sustain the Foo, or using energy too inefficiently and hastening the heat death of the universe. Or, maybe, the Bar are actually the first sentient life the Foo have encountered, and they simply have no idea how to interact. **So what can they do?** The Foo turn to all those tiny plants they have ignored since ages past. Using the absolutely foreign evolve-or-die mentality of the tricky little brush plants, they simulate high-speed realities, evolving digital sentient life that has to struggle to survive against predators and life forms encroaching on their energy. Hundreds of realities, all focused on one goal: avoiding extinction. [Answer] While I admire the Foo civilization, I do pity the **individual Foo**. As you describe, they already have achieved everything. What's left to do? Nothing. So, with such a context, how to fill your life? I predict lethargy will take over. Turning into depression all too often. That means major effort will go into recreational drugs and gaming. And that real progress is ...stuck. **Your Problem** This being said It will be either setting up the greatest game ever, for the millionth time. That would be going with the flow. Or, setting up a super-simulation to find how to achieve fulfilling individual lives when everything has been done long ago. That would be going against the flow. As this has been tried many times already it now goes back to full evolution scale. They are clearly seeking the Undying Optimist. The current bug is how to guide them past the industrial/atomic/whatever phase. It is getting hard by now to find grounds for next year's funding, so the danger of getting the hardware turned to gaming universe rendering looms ever larger. Have fun! [Answer] ## Inferiority Complex It strikes me that the main issue that such a vastly advanced race could face (one that would require the immediate construction of an entire artificial universe in order to come up with some truly "*out of the box*" thinking) is that they suddenly learned that they were **trapped *inside* a box**. Let's say that your Foo scientists are working on ever more efficient forms of information-compression when suddenly they find that something that should work, doesn't work. Try as they might, they simply can't squash data like they want to. The conclusion they draw is that **the only thing that would stop this super-compression from working is if their *universe* was already subject to some form of data compression.** Imagine the way you'd feel if you suddenly went from thinking you were the Masters of the Universe to realising that you might just be some kid's highschool science experiment. --- Given that they're stuck in a box, the obvious solution would be to create a pocket universe to study how those inside (when given similar clues) are able to escape. Your Foo scientists and warriors could then use those same techniques to storm the very Gates of Heaven. [Answer] What could cause an nearly omnipotent race to need an out-of-the-box solution? A bet with another omnipotent race, of course. Suppose two such races are fighting. Instead of bombing one another, they pose each other challenge problems. If a problem cannot be solved, one race wins. The wars would last ages in human terms. The challenges would be beyond the comprehension of humans in scope and subtlety. Refer to the Shadows and the Vorlons in Babylon 5. They disagreed philosophically over the right way to shepherd younger races. As far as I can recall, however, they avoided direct conflict with one another as the results could have been horrific. [Answer] As was noted in another answer, perhaps the Foo are looking for an out of the box solution because they want to leave the box. The heat death of the universe is an unfortunate and inevitable consequence of physics. The solution is very simple though: travel to another universe. But what if there was one other universe within traveling distance? What if the laws of physics in that universe were so different that all of the Foo's scientific knowledge was basically invalid in the new universe. (Look up discussions on "What if [some physics constant] was [some other value]" for inspiration on what this may look like) The Foo must learn how to live in this new universe in a way that matches their own standards of living, but creating a colony and experimenting would take too long. Therefore, the Foo create a simulated universe with physical laws that match their desired home and watch as life evolves and innovates. Bonus points if the simulated life attempts to break out like in [Richard's answer](https://worldbuilding.stackexchange.com/a/34214/16807) [Answer] 1. Someone has already mentioned it but didn't go all-in: a war with another similar race. There's plenty of room in the Universe to have more than one such race that have only recently become aware of each other and which may have a fundamental disagreement. (Perhaps the Galactic technology they have each designed is diametrically opposed in an almost matter-anti-matter way, such that both operating in the same galaxy destroy it.) 2. Their Galactic-level technology has a fundamental flaw that has been there since its beginning. Only now, millions of years later, as they are beginning to understand universe-wide principals do they see that their technology dooms the universe. Or dooms their race. Perhaps they have fundamentally affected the mechanisms of consciousness, or perhaps they have discovered a Darker Matter which is more fundamental than Dark Matter and they now realize that they've been rearranging it in their Galactic engineering and now Galactic Clusters are doomed. 3. If the Universe isn't big enough a stage, consider the Multi-Verse. The have finally discovered how to reach other Universes and it turns out that's a very bad thing with unexpected consequences. (Or they detect a similar race in another universe trying to reach ours and believe that they must prevent this at all costs.) 4. Perhaps the Foo have forgotten something from their distant past. For example, millennia ago there was a debate about Galactic-level engineering because it wipes out all (other) life in the engineered galaxy. Some argued that this was immoral: they should find another way to advance their technology. Others argued that this other life is essentially non-sentient -- in comparison to themselves -- and that some race eventually has to step up to this technological level. In the ensuing struggle, the second camp wins, wipes out all those who oppose them, and hides any knowledge of this. The Foo come to regard all other life forms as non-sentient -- if they recognize them as life at all. Until an oddball Foo scientist stumbles onto sentient life in a galaxy that's marked for engineering. And eventually there's a rebellion in which the rebels say that the Foo must destroy themselves to eliminate their power and willingness to destroy other life. Maybe someone eventually finds that the Bar -- the first race to reach their level -- did the same, allowing the Foo to eventually rise. Or perhaps the Bar had destroyed all other life in their universe and triggered a multi-verse in order to try to make amends. 5. EDIT: Look at the Q in the Star Trek universe. They are extremely powerful, but not infallible -- a critical distinction. (They also suffer because they've done everything and they've lost the will to live, but other answers mention that.) What happens with omnipotence without omniscience? Not to mention morality: don't make the common mistake of thinking science defines or dictates morals; it doesn't. Science only describes what is and (perhaps) what could be -- to the accuracy of its tools and the honesty of its practitioners -- not what *should* be. [Answer] I want to expand on @ArmanX 's answer. ## Foo will get blindsided by Bar: Yes, plenty of naughty Type 1 species will arise and slap-fight each other; but if they get too pesky, they can be eliminated. Somehow, Bar gets past this Great Filter. ## Foo cannot eliminate Bar: Assuming such a powerful civilization, we can assume they would poke around the other dimensions, not only terraforming planets, but actively changing time as well, probably in their favor. This makes for an easy process to eliminate Bar. For whatever reason, this is not the case now. ### Convergent evolution: Bar arises over and over, in every galaxy, in every Universe. The flame cannot be put out. ### Bar steals Foos toys: More likely, Bar started as a pesky Type 1 or lower civilization, but stumbled upon one of Foo's toys, and turned it into a weapon or shield that put them outside of Foo's ability to eliminate in their usual fashion. ## The Solution: So, I write sci-fi, and I have a similar thing going on in one of my books. The solution that Foo decides upon is simply to run away. Bar cannot challenge Foo if Foo simply vanishes from space and time altogether. Possibly some ancient broken things will be left around for Bar, or other pesky Type 1 civilizations to find; mostly though, if these other species are left to their own devices, they should just burn out, maybe taking a subset of all possible Universes with it, but nothing that cant be reshaped and reformed after the fire is out. The best analogy is how to combat most fires - simply cut off its air|tech supply and let it burn itself out. Rebuild once the threat is gone of its own actions. [Answer] Reading Bookeater's answer inspired this answer # Apathy Apathy is a very difficult foe to beat because you simply don't want to. So while the **Foo** civilization is mighty, powerful, able to do anything it wants; **Foo** individuals are gradually giving in to apathy and either committing suicide or withdrawing from productive **Foo** society. The apathy may be caused by a perception of no great goals or achievements are left for the species or perhaps there's not room left for the improvement of individual **Foo**. When you have nothing important left to do with your life do you continue contributing to society or do you seek forms of escapism like video games, simulations, and World Builder ( :) ). Obviously some continue to contribute but over time, perhaps individual **Foos** are dropping out of productive society and plugging into various forms of escape. The only thing left for the **Foo** to do is escape into simulations in which they are NOT beings of unlimited power. 1. Maybe they have to time share living in a simulation of a civilization struggling to really begin its space age. 2. Maybe our reality is that simulation. 3. Maybe we are both **Foo** shirking our **Foo**lish responsibilities. [Answer] To borrow a common trope (and also blatantly steal from the Zones of Thought and the Expanse series') **They went and made themselves a monster** Either intentionally or accidentally Foo scientists created something terrible. I'd be very tempted to go with the ultimate form of a virus: Something smart, interconnected, nigh-on impossible to get rid of and capable of co-opting any stable computational system (including biological systems and entire ecospheres if it gets big enough) in order to propagate. This virus (lets break the trend and call it Manchu) can't be stopped by the Foo, despite their great power. Every time Manchu threatens the Foo, the Foo crush it easily. But they can't crush it all, and it's starting to spread and spread exponentially, bootstrapping younger civilisations and using them to bypass the Foo's defences. With each civilisation it absorbs it gains new tricks, tricks that the Foo wouldn't have thought of until they see Manchu using them. The only solution? Get some tricks of their own. If the Foo simulate a universe where viral agents are a powerful form of life it will give them a lot of information on good (but potentially unexpected) ways to combat Manchu, for example immunisation, creating a 'counter-Manchu' virus or just updating the biological firewalls of all civilisations near them. Every time they observe Manchu using a new trick they can add a virus with that trick to an appropriate civilisation. Say they observe Manchu hiding in their own battleships and using them to spread, then a small civilisation somewhere in their simulation suddenly runs headlong into an easily transmitted disease that hijacks the immune system. How does that civilisation cope? Manchu pretty much represents the ultimate threat to the Foo: It won't stop coming, and if it gets enough of a foothold then it will be able to use the Foo's power against them. They will either submit to it's rule or die. Unless their tiny allies come up with an unexpected solution. [Answer] I would invite you to look into the Mass Effect universe. It has some similar points to the universe that you are building. * In mass effect the reapers are the dominant race in the galaxy. * The conflict they seek to avert is the struggle between organics and the synthetics. Namely the organics create synthetics to do their bidding and make their lives easier, but as the synthetics become advanced and become true AI the synthetics arise against their masters. This is where it differs from your scenario. * The reapers never sought for a true solution, their policy was a scorched earth approach as evidenced by what may be a truly peaceful AI being present in the universe they were seeking to destroy. * They make the new civilizations develop along the technology path they intend by leaving their technology to be found making it easier for those civilizations to be destroyed when they deem it necessary. An inversion of the scenario would suggest the opposite with new civilizations finding alternative methods to achieve the very same goals without the intervention. Moving away from the Lovecraftian setting, I would suggest having your FOO civilization surviving their ordeal at great cost and then electing to kick-starting other civilizations to arise 2001: A Space Odyssey style where they can make the choices the FOO made once, which then they monitor and step in if the experiment goes out of control. ]

[Question] [ It should not resist 50 cal bullets, but an armor which could protect a creature from the US standard issue rifle, for example. Here are a couple of things the armor needs to do: 1. Protect the creature from the bullets mentioned above. Take a look at @computercarguy's answer for more information on the bullets I am talking about. 2. The armor could be created from a chemical in the air into a solid piece of armor, i.e. the atmosphere contains some needed component for the armor. This chemical does not need to be in the Earthen atmosphere, it just needs to be some sort of gas, I'll work out the details of how it got into the creature's atmosphere. Note this is more of set dressing than anything else. 3. The armor should not be much heavier per cubic inch than steel. The creatures could take more, but they still need to be able to lift quite a bit around. 4. The armor could theoretically be "fixed" within a month at the max, but a little longer would be fine. Not a hard requirement. UPDATE: I am looking for two specific things the other answer is not looking for, repair time and a request for it to be based on things in the environment, a theoretical element which helps build the armor. [Answer] # Mantis Shrimp Claws will do quite nicely. Carbon is extremely abundant on Earth's surface and presumably any other Earth-like planet that the author may be working on. Given the many forms that carbon can take from the ultra-soft graphite to the ultra-hard diamond, it should be able to satisfy your needs. # Characteristics of good armor The element(s) that form this armor are important but the construction/organization of the elements are far more important. If the armor is too rigid, it will shatter. If it's not hard enough, then the bullet will pass through. (An example of a behavior we don't want is spider silk. True, it's stronger than steel at that scale but it's also super stretchy. Stopping a bullet on the other side of the target isn't very useful.) The goal will be to spread the bullet's kinetic energy over a large enough period that the armor plate can handle it. [](https://i.stack.imgur.com/9ngZk.jpg) Mantis shrimp have ridiculously resilient armor. They have to since they hit harder than most anything else in the animal kingdom. Note the many layers of fibers at slight angles to each other. In this configuration, penetrations that break through between two parallel fibers (this is the weakest configuration) runs into the next layer below that is oriented more towards the longitudinal orientation (which is far far stronger). At every layer, the bullet is forced to expend lots of energy breaking the bonds of the fibers along their strongest axis. # Fast Replacement Armor Requirement 4 is the most interesting. Growing plates like a turtle shell would certainly be effective from an armor perspective however, these don't grow quickly. Human skin doesn't offer any kind of armor capabilities but it does grow very quickly. Skin wounds can heal in a month or less (depending on various factors). Clearly we need something that will grow fast and ideally is always growing. If the armor is damaged, we don't want to have to keep carrying it around for longer than we have to. Lots of animals have disposable "armor" to one degree or another. Humans have their skin. Porcupines have their quills (which are replaced). Snakes, lizards, crabs and lobsters have their skins. Let's assume this creature is a carnivore so that it can afford the higher metabolic costs of replacing all it's armor in a month or so. Perhaps as a way to reduce this metabolic load, the creature swallows the old armor scales which are then broken down into basic components for the armor-building cells to use. Alternatively, the outer layers can just flake off after exposure to oxygen for some period. This gives the armor a natural decay rate and prevents the armor from getting too thick. Natural variation in the armor breakdown proteins could lead to some creatures with thicker or thinner armor than others. Hey cool! We just invented a way to get heavy and light versions of the same creature suited for different battlefield duties without having to breed different versions. Win! # Yeah, but how good is it? Mantis shrimp 'fists' are known to withstand [4 gigapascals](http://blogs.discovermagazine.com/notrocketscience/2012/06/07/how-mantis-shrimps-deliver-armour-shattering-punches-without-breaking-their-fists/). This is about 40k bar or [1/90th the pressures in Earth's core](https://en.wikipedia.org/wiki/Orders_of_magnitude_(pressure)). Dang. I'm going to assume a [NATO 5.56x45mm](https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO) round. It's super common and well understood. With a muzzle velocity of 990m/s. Kinetic Energy is: $$KE=\frac{1}{2}mv^2$$ $$\Delta E=F\parallel d$$ therefore $$F=\frac{\Delta E}{d}$$ Assume $E\_0=0\text{ J}$ therefore $F=\frac{mv^2}{2d}$. $$P=\frac{F}{A}$$ $$A=\pi r^2$$ therefore $P=\frac{mv^2}{2d\pi r^2}$, where $P$ is the pressure in Pascals, $m$ is the mass of the bullet in kilograms, $v$ is the muzzle velocity in meters per second, $d$ is the distance the bullet travels in meters, and $r$ is the radius of the bullet. With all that, we get that the pressure exerted on the armor is $$\frac{.004\cdot990^2}{2\cdot d\cdot\pi\cdot0.00285^2}\approx \frac{77}{d}\text{ Megapascals (MPa)}$$ The farther away the gun, the less pressure exerted. With simple algebra, we can find that you would have to fire from just under *2 cm* away to reach a breaking pressure of 4 GPa. This is only an approximation since these calculations don't include angle of impact, thickness of armor, ablation effects, the liquid characteristics of metals at high speeds and small time frames, tungsten at high speeds, possible pyrophoric effects, and so on. # Turn it up to 11 So far we've been talking about common mantis shrimp armor. Cool. Let's turn it up to 11 by replacing whatever carbon/calcium materials are in their fists for carbon nanotubes. Given that the theoretical maximum for carbon nanotubes is approximately 100gpa (about 25x our baseline), replacing a substantial portion of the default fist matrix should yield impressive strength gains. I'm no materials engineer so I can't prove it. I only play one on the internet. [Answer] Good News Everyone! We already have a [natural armor that can resist bullets](https://phys.org/news/2011-11-nature-armor-stronger-materials.html). I introduce to you the humble [Abalone](https://en.wikipedia.org/wiki/Abalone#Structure_and_properties_of_the_shell). [](https://i.stack.imgur.com/9sdc7.jpg) After millions of birds pecking at these things trying to get to the soft, gooey interior, they have evolved the best shell currently known to man. These shells have literally evolved to withstand concentrated, rapid forces. If you crush and glue 2-4 shells together, you can make a little 1-inch super shell. This super shell can literally withstand bullets. It accomplishes this by having a highly ordered shell. If you zoom in, it looks like a bunch of little bricks in a brick wall, whereas other shells look like a bunch of little sticks randomly glued together. This is still the subject of research of [many material scientists](https://youtu.be/VdaJeXoZq7s), but I do know that the [NSF Center for High Voltage/Temperature Materials and Structures](http://www.hvtcenter.org/), which draws members from Denver University, University of Connecticut, and University of Illinois at Urbana-Champagne, and Michigan Tech., are actively looking into this. Sadly, I don't have the exact data right now, and I don't think they've published any yet, but unofficial reports show these layered shells do withstand bullets from low-to-medium power firearms, and shows promise of even withstanding higher-powered firearms. When they do break, they crack, but mechanisms similar to bone re-growth could be used to help repair it. Alternatively, a creature could have "abalone-inspired" plates which regrow after a particular amount of time. While these are not currently made from the air, the elements needed are biologically available. These little mollusks may be the key to better bullet-proofing in the very near future. [Answer] All of the answers that I've skimmed over are really good, but there's one fatal flaw to all of them. When I was in Army Basic training in 1997, we used the M16A2. The standard round for that was the green tipped armor piercing 5.56mm round. For demonstrations purposes, the drill sergeants filled an empty steel ammo box full of water and shot a hole completely through it, including the back side. <https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO#United_States> I'm assuming that "US standard issue rifle" means US military. Things have changed since 1997, but I would assume that current military weapon standards retain the armor piercing capability. I'm not saying the M16 rounds or the rifle rounds of today can pierce a tank, but could pierce a vest. <https://en.wikipedia.org/wiki/M16_rifle#Terminal_ballistics> That link states multiple penetrations stats for the M16, with the (I personally think) most interesting stat being the "31 layers of kevlar". This doesn't state whether the test were using the armor piercing round, but it seems like it. As good as even @Green's answer is, I don't think even the mantis shrimp claw could withstand armor piercing bullets. The carbon nano tubules might have a fighting chance, though. I remember a book entitled "Sentenced to Prism" that talked about silicon based life forms of a massive variety. A quick Google says Alan Dean Foster is the author. One of my favorites, and it talks about organisms that can take a beating, lasers, and I think even bullets with a variety of defenses for each. It's a great read, so you'll probably enjoy "researching" that book some. Good luck with all your research and I hope you find something worth using! [Answer] **Carbon nano tubes!** If the atmosphere has a lot of CO2, say from volcanoes, pollution, or whatever, you could suck it in, break the carbon oxygen bond, keep the carbon and release the O2. Then you take those carbon atoms and string them along into long chains, form those strands into tubes, and now you have a carbon nano tube. Then you can take lots of those tubes and weave them into a thread. Take lots of threads and weave them into a very strong cloth. It probably wouldn't be all that fast though. For a creature to do it using biological means isn't all that crazy, as lots of bacteria use chemical processes to break molecular bonds, and instead of weaving the fibers into a cloth it could embed them into it's skin to toughen it. This would be a gradual process that starts at birth as skin cells form, and the older it got the thicker and tougher the skin would grow. If the skin is damaged, new tissue would grow to heal the wound, which would have new carbon nano tube strands, and the scar tissue would be tougher than the original skin. Our body armor has reinforcing ceramic plates in key locations to stop blows to soft organs. This creature could easily do the same thing with bones like ribs to absorb and shield the kinetic energy. They would also be self healing if a bullet is able to damage one. One interesting part of this is that if the creature acquires it's carbon from CO2 it breaths in, it could potentially recycle the CO2 from it's own exhalations, which means that it could potentially hold it's breath for a very long time. [Answer] I can't satisfy all the requirements of the OP, but here is a partial solution. A naturally occurring fiber that is capable of being used to create a bullet stopping armor is **SILK** Silk has a very high tensile strength and is elastic. It is naturally spun by silk-worms. In the real world, the silk fibers sourced from silk-worms needs to be spun into fabric, which is then tailored into a protective bullet-proof vest. So called [Dragon Silk](https://www.livescience.com/55423-spider-silkworm-silk-protects-army-soldiers.html) is already under development for bullet proof vests for US military. The use of silk based fabric for armor is actually [old](https://www.thesurvivalistblog.net/silk-body-armor/). However, with modern [genetic engineering technology](http://www.defenseone.com/technology/2016/07/army-testing-genetically-engineered-spider-silk-body-armor/129814/), the genetically modified silk-worms are capable of stopping bullets. There are two ways in which this would work on a 'natural' setting: 1. **Symbiosis** : The creature has a symbiotic relation with silk-worms, that spin several layers of their silk fiber around the creature. This provides the creature with a armor. The worms do this continuously, so the armor is regenerative even if it is partially damaged. 2. **Stem cells** : The genes of the creature as spliced with that of silk-worms such that the skin of the creature creates this silk-fiber. Over time the skin of the creature acquires several layers of this fiber that gets inter-meshed, to serve as an armor that protects it. The atmosphere requirement isn't pertinent here. But the silk based armor is a 'realistic' technology that is currently under development and therefore a plausible option. [Answer] Do you need armour that stops a bullet like a steel plate, or armour that stops death even if there is some injury, because if the latter you just need a high-tensile fabric 'skin' that has enough give to it to absorb impact. Old Mongol horsemen used silk shirts to defend against arrows - they worked even though the arrow would hit and stab into them, it wouldn't penetrate the silk and the arrow wouldn't do much damage. Kevlar works in much the same way - the fabric doesn't get cut through and the bullets cause only bruising damage. So a creature with tough, but relatively loose skin with a good layer of blubber behind that (kevlar vests flex by up to 4cm apparently) would be quite safe, to a point. An alternative would be a creature with a subdermal layer of fat made of custard ([or something similarly non-newtonian](https://www.sciencealert.com/liquid-armour-is-now-a-thing-and-it-stops-bullets-better-than-kevlar)). Always beware the custard-monsters! [Answer] All answers on this question are measuring against a direct perpendicular impact. I would expect a sticky coated armor that would present a geometrically angled surface might have some effect on slowing down a rifle round enough that there would be little penetration. Try to develop an completely inelastic collision with angles to create lateral forces and friction to reduce the penetration vector. It might take a period of time for the atmosphere to re-coat the armor with this adhesive goo or to realign the geometric plates. [Answer] How about steel? Steel is Iron and Carbon, in theory an engineered lifeform in a reasonably metal rich environment could have a bark-like growth of steel in place of its dermis, this material grows from the inside like tree bark, being relatively inert in it's outer layers. Life on Earth can already suffer from excessive Iron, it caused a disorder called [hemochromatosis](https://en.wikipedia.org/wiki/Iron_overload) where excess Iron from dietary intake mineralises in the blood causing organ damage. This creature does the same thing, re-mineralising ingested Iron but only in it's skin and on purpose, this creature would have enhanced Iron absorption mechanisms and possibly also use an Iron, rather than Calcium, based skeletal chemistry to simplify its Iron absorption pathways (most vertebrate life on Earth has digestive chemistry geared to absorb Calcium preferential to Iron). Sorry I don't know how thickly it would need to be plated in steel-bark but it would be a continually growing and incrementally shedding armoured shell. I feel like I missed something so let me know if you need anything else. [Answer] Building on the idea of an earlier answer, multi layer armour. Layer 1: outermost; a tough flexible sheet, possibly some sort of strong leather, that can bend slightly. Protects the inner layers from superficial damage; allows some freedom of movement. Layer 2: first inner layer. Some [gel like substance](http://www.telegraph.co.uk/news/uknews/defence/4862103/Military-to-use-new-gel-that-stops-bullets.html). Slows down the bullet as it passes through and disperses the energy of the bullet hitting the third area. Layer 3: plates of ceramic composite (bone or chitin). Plates instead of a single large plate to allow wearer to move. The bullet will shatter the plate it hits, but the energy of the shards and the reaction on the bullet will be absorbed by layers 2 and 4. Layer 4: a thinner version of layer 2. Prevents shrapnel from forcing its way through the last layer and injuring the wearer. Layer 5: Silk or leader inner armour. Absorbs any remaining momentum and acts as a framework on which to build the other layers. The problem is that any armour thick enough to stand up to an automatic rifle is going to be too heavy to wear. What this method does is to treat the incoming bullet as the tip of a wave and try to refract as much of it away as possible. Deflection instead of blocking. It probably won't stand up to a shot at centre mass, though. [Answer] # Graphene > > Lee and colleagues devised a new miniature ballistics test to test graphene’s mettle. They used a laser pulse to superheat gold filaments > until they vaporised, acting like gunpowder to fire a micrometre-size > glass bullet into 10 to 100 sheets of graphene at 3 kilometres per > second – about three times the speed of a bullet fired from an M16 > rifle. > > > The team found that graphene sheets dissipate this kinetic energy by > stretching into a cone shape at the bullet’s impact point, and then by > cracking outward radially. The cracks are one weakness of single-layer > graphene, Lee says, but it nevertheless performs twice as well as > Kevlar and withstands 10 times the kinetic energy that steel can. > Using multiple layers of graphene or incorporating it into a composite > structure could keep the cracks from spreading, too. > > > Researchers have been studying graphene as armour for some time, but > Lee’s is the first paper to describe just how the material absorbs > kinetic energy. Sound waves travel three times faster through graphene > than they do through steel, which means material far beyond the impact > point can quickly absorb and dissipate its energy – effectively > slowing the projectile down and helping prevent its penetration. > What’s more, the microbullet methods Lee developed could be used to > study other high-performance materials in extreme conditions. > > > <https://www.newscientist.com/article/dn26626-bulletproof-graphene-makes-ultra-strong-body-armour/> Better yet, [it is self-repairing](http://pubs.acs.org/doi/abs/10.1021/nl300985q), too! Just add free carbon atoms and they will snap into place in a broken lattice. [Answer] **All prior answers suggest the direct route of materials with high strength.** **I suggest an alternate solution, based on inertia.** Any projectile has a certain mass, and it imparts momentum from that mass onto its target upon impact— No matter how fast it's going, it can only penetrate so far before it's shed enough of its momentum into the struck material that it stops. [And because the amount of inertia it sheds per unit time is proportional to its speed, the approximate penetration depth is the same for all high-speed impacts.](https://en.wikipedia.org/wiki/Impact_depth) **Therefore, I believe the idea form of biological body armour for stopping bullets may be body fat, or even water** (in the form of a jelly). It looks like most US rifle bullets are around 5cm long. If we assume they're made out of solid copper at 9g/cm³, we can calculate the approximate depth of fat or water (~1g/cm³) that would be required to equal its inertia: `D = 5cm*((9g/cm³)/(1g/cm³))` `= 5cm*9` `= 45cm` Since this is the theoretical ideal case, we can multiply it by two or three times to give a more realistic margin. Doing so also yields figures that are consistent with [what the Mythbusters found when they shot a variety of gun types into a swimming pool.](https://mythresults.com/episode34) A meter of fat and water sounds like a lot to lug around. But when you compare it to the size of creatures like elephants and whales, and how much blubber they already have just for thermal insulation, it's not really that much. If the armour is concentrated at a single area like a camel's hump, they could also use it as a shield by pointing it towards danger. **Crucially, this solution also has a wide variety of benefits that are unique to a biologically synthesized armour:** * **It doubles as an energy reserve.** Since water is essential for life, and fat is a very compact calorie source, armour made out of water (jelly) and body fat also serves a purpose even when it's not under attack. Maybe the organisms in question already had exaggerated, camel-like reserves of fat and water because they live in a desert, and they simply evolved to expose it as armour when under attack. Maybe they're scavengers who feed on the scraps left behind after a war; They build up fat to use as protection during times of conflict, and during peacetime, when there's less food for them and there's no need to fear bullets, they gradually digest their stored fat and water. * **It can be grown almost instantly, and for free.** Because there are no special structures involved— no nanotubes, steel plates, woven silk threads, or special shells that must be grown— the organism with this kind of armour does not have to spend nutrients, calories, and genetic complexity on constructing an organ whose only purpose is to be destroyed. * **It is arguably immune to damage, and can be repaired almost instantly for free.** Likewise, because it's not the structure of the armour so much as its sheer bulk that gives it its protective properties, it will continue to function even after it's been all shot up. Healing is also easy due to its simple structure, and even in the event that it gets severed from the organism's body, they can just eat it and have it digested and restored within a couple of days. * **It requires no special nutrients or minerals.** Since water and fat are both essential chemicals for basically all known life, any organism is already capable of finding, processing, synthesizing, and growing them. Water can be pulled from vapour in the atmosphere, and fat can be constructed out of CO2 (like in plants, I think). * **It can synergize with other protective strategies.** Since defeating the projectile takes place over the entire depth of the fat and water, the fat and water armour could offer any level of protection in proportion to its thickness. This opens the door for some **unique composite armour growths**. For example, a thinner layer of easy-to-repair fat and water armour could slow down a projectile just enough that it's then stopped completely by a simple bony plate, or you could have hard but simple chunks of denser material embedded at the surface of the fat and water layer to break up a projectile and let it dump its momentum more quickly over a shorter depth (kinda like a [Whipple Shield](https://en.wikipedia.org/wiki/Whipple_shield)). **This allows for optimized combinations of easy reparability and minimized bulk**, from the fat and water and the plate armour respectively. * **It makes more evolutionary sense.** Any brute-strength armour that can resist bullets is likely to be extremely biologically costly to construct and maintain. Furthermore, the fact that armour is inherently a sacrificial tool means that even an unsuccessful attack will probably incapacitate the organism for long enough that they'd starve to death while trying to repair their armour. The gain in defensive ability simply may not be worth the cost in calories and genetics. Under circumstances like these, Evolution tends to give up on making super-powerful individual creatures, and instead create individually weaker creatures that overwhelm survival threats by making thousands of babies. **In order for "natural" bulletproof armour to evolve and persist, it needs to be simple enough and calorically inexpensive enough that the costs of its growth and repair do not outweigh its benefits for survival. I believe bulked masses of extremely simple biological material may be the best and likeliest way to achieve this.** [Answer] Armadillos. There is at least one documented case of an armadillo being resilient to pistol shots: <https://www.huffingtonpost.com/entry/texas-armadillo-shooting_us_59838ae2e4b08b75dcc5f622> (.38 shots fired at armadillo, animal was able to walk away, shooter got severely injured by ricochet). [Answer] An amour with many layers. As each layer will reduce bullet speed. There are examples in the animal kingdom where animals grow layers of hard shells or use natural resources like sand, etc. to create armors which can stop even a bullet. ]

[Question] [ Let's start with [Sanderson's-first-law](http://brandonsanderson.com/sandersons-first-law/). Although I like reading stories with soft magic, this is not question about them. I would like to work with hard magic - the magic bound by strict rules. So far in either the literature or games (RPG, strategy, pen and paper, etc.), there are rules, yes. But the world is usually converted-medieval or something similar (by converted-medieval I mean world with magic, that is built with the normal world as a base, usually with only the most obvious loopholes covered). And rightly so, to read the story and see it as interesting, you probably want reader to have something to relate to. But there is the issue I have with them, and the core of the question - if I follow through with the effects magic would have, then sooner or later (usually sooner) I arrive at a point, where the logic of world does not hold. A few examples: 1. Spatial magic (e.g. teleportation, portals, and blinks) has disastrous results. If I take something really heavy-weight like portal, you nearly immediately get something that breaks security by enabling attacking/retreating with greatly diminished risks, you would break trade (can be mitigated by having cost high enough, but still), create ton of similar problems that would shape the world differently. For example, why build fortifications, when the enemy can transport troops past them, and even if there was plausible way to build something of sort, these would be much more expensive and thus rare. Not to mention the fact, that one (or maybe dozen) spellcaster(s) effectively destroys work of hundreds of workers - maybe not such a big deal, wizards can be powerful, but still. 2. Well, maybe spatial magic is too broken. So, what about telekinesis? If we allow movement of objects, through the force of will or magic, or anything similar, once again [broken](https://www.youtube.com/watch?v=d5Gz7MeSbF4)- nice example (I like the concept, imagine this in world without guns, crossbows possibly, but they are still much slower). However it should not be hard to find something with even more drastic effects. 3. OK, no telekinesis; let's tone it down to energy manipulation. But why hurl a fireball (although it sure looks nice) when I can simply boil the brain of the opponent directly? Or something along these lines. And I can continue. **The question being - how do I limit magic in a way, that keeps it interesting (it's MAGIC) while keeping the basis of the world similar to medieval?** (or hell, similar to modern one, urban fantasy is nice as well - but modern world started as medieval...) Or slightly different variant, but for me with similar results: **Have you met a magic system, that would not crush the world you saw it in (by critically disrupting the balance) if you took the magic system to its logical consequences?** A few things to clarify * I do not accept "they would not think of it" as an answer. Someone would; people are naturally curious. * I assume that when something is possible to do with magic (creating a large enough ball of fire to actually burn someone) then something similar (boiling him alive instead (or the critical part)) is also possible - limiting magic to few time-proven use cases is not the answer I am looking for, mostly because of the same reason as previous bullet - if someone tried this for ages, he would have found out more effective way of using power. Wizards tend to be smart. * I am perfectly fine with side effects like towers of the magi in the landscape; I am only trying to balance logic/magic in a way that works, yet is still interesting. * Quick thought - limiting the amount of power (I mean drastically, of course it is limited. But let's keep it at middle-to-lower fantasy level) that mage wields sure sounds nice, but it does not work too well - as when you can leverage that power well enough (manipulating a needle is enough to poison someone important - voila, assassination becomes a much bigger issue, as if it wasn't easy enough to kill someone already). At the moment I see two major possible ways out of this (or some kind of their combination), but I would really appreciate more insight. First way - magic exists broken (no way around it), but for some reason is not used in such a way. Codex, rule set, whatever. Brings issue of upholding the rules. Second way - find system that is not broken. I have some thoughts on this, but I'm the one asking the question so I would prefer original answer instead of discussing flaws in mine - and there are flaws, otherwise I would not be asking. I have tried to find an answer to a similar question, without result. Also maybe I should have split this one into two - how to uphold rules when magic is broken and how to find unbroken magic. If this becomes an issue, I will. But I think of this as one question - "having interesting magic, while preventing the world-disruption". [Answer] Trying to "balance" magic like this is not an easy task. There's plenty of examples of videogames where people literally make a living balancing the magic in that videogame, and balance is still an issue! However, there are a few points you can address to help keep your magic system as balanced as you can. **Society is balanced around natural physics.** We have societies today which are built around what can and cannot be done in the physical world. We are constantly balancing the need to be close to each other against the need to be protected against each other. Any "disruptive" technology will change this balance. Nowhere is this more visible than in warfare. The gun completely changed the way armies interacted. Any army which relied on the old pre-gun assumptions died off. Your magic system would qualify as a "disruptive" technology from this viewpoint, and your society will have hundreds of years of time to have adjusted their customs. Magicians have the ability to boil your brain at a distance of 10 feet? Don't be surprised when society politely stays 10 feet away from anyone who looks like a mage. Don't be surprised when royalty issues clear rules to murder anyone who foolishly advances to within 10 feet of the throne. Society will adapt to such magic, unless your magic is so incredibly unbalanced that not even society can keep up. In such a case, one should simply build a story without society, and focus on "man vs. nature" or "man vs. himself" storylines! **Pay attention to conservation laws** Conservation laws are ingrained deeply in our understanding of physics, even long before they were given the name "conservation laws." Any infant learning to crawl is already learning to work in a world where conservation of energy and momentum apply. These laws are so deeply associated with our understanding of physics, that many of them are fundamentally associated to the basic symmetries of our laws. By [Nother's Theorem](https://en.wikipedia.org/wiki/Noether%27s_theorem), we can show that the mere idea that the laws of physics do not change over time *forces* there to be a conserved value: energy. The mere idea that the laws of physics are the same in all places *forces* there to be a conserved value: momentum. Breaking these conservation laws upsets so much of physics that you are basically opening a can of worms every time you try. Thus, don't make fireballs free. Make sure mages have to pay an energy cost for putting that much thermal energy into the world. Don't want to make it a boring zero sum system? Make the sources of energy well defined and isolated from the mages that use that energy. Conservation of energy is a big deal in physics, but if you're willing to handwave away the fact that our sun is going to die in 4 billion years, you can treat our sun as a external "source" of energy. If your mages' source of energy feels like the magical equivalent of a sun warming the surface of the Earth, you'll keep your mages in balance. **Distance matters** Define some concept of distance, such that it is harder to have a magical effect at a distance. This is intuitive in our day to day life. Things close to our body are easy to control. Things barely within our grasp are harder. Things just within our reach are harder still. Then, we see that it is actually quite unintuitive when something brings us closer together than we think. We don't realise just how close we get to someone when we hit Post on a social media site, until it's too late. Our understanding of distance was flawed, and thus our intuitive model was wrong. You don't have to make the distance for your magic system a boring measure of physical space. Mental distance may be meaningful. A "distant" individual might be harder to manipulate with a magic spell. Certain "cold" feeling gems or armor might have the effect of adding "distance" between two individuals. Strange astrological events might bring people closer together. However, if you use distance as a limiting factor, you'll find you balance things more evenly. Also consider stability. We know that if you have a teepee, it is more stable if the legs are wide than if the legs are narrow. We know that a tall tower is less stable than a short one. If you can have concepts of stability based on metaphors like this, you'll naturally make things which have reasonable limits to them. For instance, this way of thinking naturally points out that the power it takes to summon a gargantuan fireball at close range is not necessarily the same power that it takes to subtlety manipulate the mind of a king from afar while he sleeps. The former requires great power, but is being done in a naturally stable position. The latter requires very little power, but must be done from an incredibly tricky position (and be assured the king has wizards who are watching for the side effects of a careless mind-manipulation attempt. You're going to have to have the magical equivalent of surgeons hands to avoid detection) **Non-transitive laws** You mention a specific case that is worth talking about: > > I assume that when something is possible to do with magic(creating large enough ball of fire to actually burn someone) then something similar(boiling him alive instead(or the critical part)) is also possible > > > This is a good principle. It leads to far more interesting magic systems. However, if you have some concept of distance, it should be clear that just because A is similar to B, and B is similar to C, that doesn't mean A must be similar to C. There's some level of distortion that does occur as you try to apply such a transitive property. This is true for any non-linear system. Accordingly, it is reasonable to explore spellbook "creep," as you mention. However, the new spells may not be *quite* as effective as the original. After all, they're being prescribed "off label." Over time, it is reasonable to assume mages will refine this new spell and make it powerful again. It is this refining process that gives you a chance to retain control over the magic system. The refining process may have to give up properties of the old spell in order to acquire new more valuable properties. Thus when you let spell A creep into becoming spell B, spell B may be too weak to also creep into spell C. However, we can develop spell B', a new spell with new properties, which could creep into spell C. You can balance it as such. You may find that you can avoid lots of loopholes by controlling the process from B to B' while permitting characters to control the process from A to B and B' to C. **Value Metastability** A lot of things are not actually set in stone, they just linger much longer than we expect. Airplanes are *not* lighter than air, but we found ways to use them such that they get to fly far longer than anyone would have thought possible a hundred years prior. We value this metastability greatly. Its powerful, and it has changed our economy. However, it is transient. Try to shave costs by putting less fuel in the aircraft, and you find out just how transient it is. Wizards are transient. Other than perhaps a select few that are immortal, most of them have something they will lose over the years. They may linger far longer than others expect, but they are not permanent. If you make it so that casting "risky" spells increases the likelyhood that you will lose something inside you that you cared about provides a natural balance for magic. Wizards that push the mold too hard don't live very long. It also demonstrates just why Necromancers are oft so scary: they are wizards who no longer have anything they worry about losing, besides their own power. Thus they can cast spells no one else would risk casting! Personally, my favorite approach to magic involves having the entire magic system act as a metastable character that *seems* to be perfectly stationary, but every now and then shows an edge that suggests "If you guys keep using magic in this way, the entire system of magic *will* shift to stop you." This Gaia like approach is fun because it permits you to use more dangerous rulesets. The more the characters try to screw with the system, the more the system pushes back at them. However, even if you don't go with such a self-aware magic system, at least the heart and soul of the wizards casting the spell can work as a natural limiter. [Answer] Sooo many answers. First, you won't find a system that leaves medieval entirely intact, and that's fine. One of the jobs of good world building is to think through the implications of anything new you add to a setting and extrapolating how it affects your world. There are many things we can do to make the magic fit in 'nicer' with your world, but your still going to have to think through what things it changes. Going along with that, remember that if you can think of it not only have people come up with it, others have come up with counters to it. If magic-portal invasion is a threat someone creates a spell to prevent creation of portals in your castle. If people start throwing lightning bolts around insulated armor with 'grounding boots' to direct the lightning away from the body becomes common. If someone uses magic for assassinations others create magic tracking spells to easily track the assassin down and punish them etc. Creating intelligent counters to uses you don't like is ultimately going to be required to some degree. Likewise there will be some things you may not want to 'counter' in such a manner. Perhaps magic fireballs prove more effective then arrows for long range attacks, and you don't want to create an obvious counter, like anti-mage individuals responsible for blocking or stopping magic attacks in squads. Then you should run with this, what does this do to combat? maybe armor changes now that protection from arrows is pointless. Maybe lots of small squads that are more spread out are used to limit the harm a fireball can do. Maybe assassination of mages before major battles are common. Most extreme, maybe defending a ground becomes far easier then attacking and tactics more similar to the world wars, where machine guns likewise redefined the ability to charge a point guarded by someone with lethal ranged weapons, occur. In short whatever system you create it will be your duty to sit down and think of exceptions or how magic changes. Almost anything you really dislike you can justify a reason why it won't work, and you should leave some changes in and explore how it changes your world. *showing* magic change the world makes the world feel more real, and so long as not done too drastically does not make the world feel unrelatable. Just remember you can't stop at one step. If magic changes element A of the world then ask how changing A will affect B and C, and how they in turn affect D etc. It's an iterative process that can go a long way to building your world and helping to make it feel unique and real. Not always easy, but still desirable. Having said that, lets focus on your actual question, what can we do to limit the affect magic has on the world. Not remove it entirely, but lower how drastic the affect is. **Magic is new** In many ways this is the easiest option, magic is a recent development. People have only recently discovered the existence of magic, or magic has recently become more powerful due to some new discovery or change in some magical principle. This works so well because the people of the world don't know how magic works yet then their culture wouldn't have changed to adapt to it. Remember cultural adaptation is slow, even once a change means that the world would make more sense doing X it can take as much of a generation for the culture to realize that they need to stop doing Y and do the more logical X. Thus a culture can still be 'stuck' in some non-magical view of the world even though magic has been around for a little while. The culture doesn't make sense given magic's existence, but not because *you* made a bad world, but because your believable world is just as slow and foolish about adapting to change as people usually are. **Conservation of Everything** If you want your system to work and be at all believable your are going to have to stick to conservation of mass/energy very hard. Any violation of these principles leads to *some* sort of exploit to break thermodynamics in a way that's going to radically change the world. Of course, it's nearly impossible to have an interesting magic that doesn't violate one of these fundamental principles in some manner, and if you do it's likely a magic that is not very useful. However, there is some room to *bend* the rules, particularly in conservation of energy. It's okay if you get more energy out of a spell then you put in, hand wave it by saying it's being drawn from some external source, However, make sure that energy put in is still proportional to energy gotten back out. Your mage is going to exhaust it's magical reserves in some manner if it keeps producing energy out of no where, and will do so before the energy produced is too drastic. Furthermore, having much of the energy produced only stick around while the mage focuses on it, and disappear once the spell is ended/disrupted, further addresses this. Conservation of mass is in many ways more important to conserve. If you can summon something out of nothing and make it stick around you can bend practically every rule out there. Generally speaking I suggest either not being able to create any mass, or if done it's something that lasts only as long as a spell is actively maintained (for instance, a shapeshifter can change their mass to change shape, but as soon as they stop focusing they change back to their original shape, and you can't cut gigantic slabs of meat off of someone shifted into an elephant and have them stick around once he changes back etc). **Long range communication is limited** One huge change on recent world is the presence of phone, tv, and internet making communication over long distances easy. This caused a huge change in our culture, if subtly. Most obviously it changes the "us vs them" mentality we use to have of certain groups by making it easier to speak with them. It also means spread of ideas and memes across the world. The most obvious, but by no means only, affect rapid communication would have is to do away with a feudal system. Nobel's had near-absolute control of his personal lands in medieval times, This was necessary because it was too slow and difficult to appeal to a king or the kingdoms law as a peasant, someone local and reachable was required and he had to have the power to make decisions immediately. However, with rapid communication a kingdom can pass laws and enforce them easier across his entire nation, without worrying that a decision he makes about a problem 3 months ride to the east will be out of date by the time it arrives etc. Once a king/government *can* effectively rule over larger lands they would then be oppose to giving so much power/independence to smaller ruler bodies. In fact the USA, and many other countries, have shown a similar tendency to move towards centralized governments as rapid communication developed. Roughly speaking states of the USA are analogous to feudal lords of the past, while they are much lager and with less absolute power they still serve the goal of creating smaller ruling body designed to make rules designed to support their local needs that a larger government has difficulty regulating. With the development of rapid communication more power has been drifting towards federal government over the states with time. As people through of themselves less as "Marylander" or "Californian" and more as an "American", who happens to live in a specific state, they became more open to the idea of central government because they were less worried about defending their individual's state's sovereignty over trying to support America as a whole. The peasants would also be less likely to abide with feudal rule, which placed them in a near slavery to enrich the coffers of nobles, if they had access to rapid communication of their own. With more access to learning that comes with rapid communication, the ability for peasants to communicate and discuss revolution without feeling isolated and powerless, and awareness of faults of nobility and/or how they are spending the wealth your making them all would incline peasants to fighting for more power. We've seen revolts all over the world linked to twitter, texting, and other rapid communication making it easier to organize the masses. In short the more readily available communication the more the tendency towards larger centralized governments, the more available it is to the lower class the lower the tendency towards ridged social class systems or subjugation of the 'peasant' class. This is only *one* example of many things that rapid communication changes. As such it's best to be careful with any form of rapid communication over a distance. It's so absurdly useful, and world changing, that it would require substantial world building to work around, and likely will not look like feudal/medieval period your use to. This also requires caution about anything that could lead to rapid communication, even if that was not the intent of the magic in your own mind or it is difficult to do. For instance the ability to transport from A to B equates to rapid communication and thus could need restricting. If such a transport spell were difficult and costly enough it may be possible to keep without completely doing away with feudal system, so long as you accept that being a carrier will likely be a huge part of any mages job, and consider what rapid, but very limited, communication, used only for the most important messages, would do to your world. It's generally easier to forbid this entirely though. Certain permanent transportation portals from point A to B, that are huge public works to produce and maintain and can't be easily created or moved, are more forgivable. You just have to work with the realization that A and B are effectively neighbors once such a portal is created, culture, memes, information, etc will pass rapidly between their borders and the culture between the two must be adjusted accordingly. **Be careful with spells that keep working long after your mage is done casting** In many cases any enchantment that lasts forever is bad, though in reality this is simply a side affect of conservation of energy, if I cast a spell once and it keeps doing something that takes energy to do then *eventually* I'm going to have produced a disproportionate amount of energy. Though you could get around this by having mages constantly 'refresh' a spell to put in new energy in it. However, I would take this a step further then just that. You need to avoid magic-as-technology if your setting the world in the past era, and that means enchanted items that can serve as technology must be very carefully handled. A piece of magic may seem small, like making a small stone glow with it's own light; light doesn't take much energy after all. However, if it's simple then mages will likely start producing and selling them regularly, and now you have a flashlight/lamp item that is free for everyone to use. This will drastically change the pattern of daily life, if light is so easy to come by (fires and lamps have a more significant continual expense and inconsistent lighting which limited how they could be used). You could say the stones are hard enough to make that they aren't cheap, but that just means only your nobles get your technology, which furthers divide between noble and peasant but still results in a pretty different world. My suggestion would be to be very careful with any spell that a mage can cast and then walk away and leave running once their no longer focusing on them. You can have some, but if you want to make a system that's easy to 'fit in' to your target timeline your probably want to stick mostly to one of three options. 1. Large, stationary, works that took extensive effort to create and are constantly requiring mages to revisit and refresh. You can make these rare enough and easily decide which work you do or don't want to exist by simply saying only certain types of spells are cost effective enough to be viable. 2. Meta-magical items. By this I mean items that mostly affect magic itself. Most obvious being items that detect magic, or block magic, or allow affecting magic. We have no history of magic so these sort of items aren't going to cause your world to feel less in keeping with the time period you came up with since they only affect something that is new to your world. They are also potentially useful for serving as magic counters (see below). 3. Very short lived enchantments. Anything that requires a mage to make and tends to degrade in it's power quickly can't serve the role of technology or automation since the spells collapse too quickly to constantly be replacing the magical technology for regular use. This gives a useful manner to have characters who aren't magic have access to something magical for a little while, by saying it's just recently been made for them. A standard trope is that sunlight or dawn refreshes magic, so spells that tend to break by the start of the next day, or degrade at start of day and likely will collapse after only a few days, could be fair game. You can always add other items as needed for your world. But for any other enchantment your need to put serious thought into how it works and what affects it will have. In particular ask how hard it is to make and if it will become something every day people would have, or even 'just' all the nobles and rich will have, because if so it may serve as technology and your need to build your world around presumption that a group of people have it. You may have some 'wiggle room' for very specific types of magic if you claim they aren't useful in most cases, but justifying why some odd magic can be created as an enchantment but no other magic can gets to be difficult. **Counter Magic** Magic designed to counter undesirable magics is a very common trick to address some problems. If something is too game breaking have people go out of their way to create a magical counter to that problem. It may be a spell that stops specific spells from working in an area, or a spell to stop all magic from working. Separately, a good counter to many game breaking magics can be simple rule of law. Maybe magic can let you get away with lots of things in the short term, but your going to be found out and punished quickly. For instance maybe there is a spell you can work to charm people into doing what you want, but it will rear off after some time and they will remember you worked it on them and report it to the magistrate who will have you arrested and *harshly* punished? Or maybe regular checks for mind-magic are done and if they 'detect' mind magic on you, meaning you have cast it recently, your are likewise punished even if they don't know how you used it. There are many similar options, but basically whatever magic you work can be identified and is so harshly punished that few are foolish enough to risk the punishment for the reward. However, it may be even simpler, people engaging in standard practices or building in 'mundane' anti magic solutions to protect from particular threats. Perhaps running water interferes with magic and so to prevent shapeshifters from entering a village an aqueduct is built that runs along the perimeter of the town, ensuring anyone entering it will show as their normal shape? Maybe it's known vampires can't enter a building without an invitation so no one ever invites anyone in their house, instead if a door is open it's taken to mean someone won't be offended if you enter without invitation. Maybe a mage can set you on fire with their mind, so everyone knows to preemptively attack a mage if they start casting a spell without permission so they can never work their magic on you? The point to all ideas is the same, people come up with solutions to stop mages from doing things they don't want done. At the most extreme make it the nature of the magic that it's usually easier to counter any spell then to cast it and your pretty much prevent most malicious uses of magic. **Bias against magic** This is, at best, a minor 'fix' to any magic system, but a bias against magic can partially help explain why a society insists on doing things the non-magical way even though magic would seem to be more logical. This could therefore help solve some questions of "wait, if magic does that why not use it for XYZ" with the solution of "people don't like using it that way" This could be the whole "magic is evil" view, but it doesn't have to be so extreme. Perhaps over use of magic is seen as decadent/lazy so people do things the "hard" way because they want to prove their not lazy, even though they don't hate magic. Maybe magic is thought as something that everyone knows should be saved for some specific causes, as such it's considered wasteful using it for some other reason, even if it would make it easier. One of the easiest biases to justify sticking into society, other then 'magic is evil', is a religious one. Perhaps their religion believes that magic is holy and so only priests should use it or it should only be used for 'holy' uses. Perhaps instead it's believed that hard work is part of our lot in life and using the great magic given by god to frivolously to make our life too easy is decadent or sacrilegious. The great thing about a religious bias is that it's much easier to create a far more nuanced bias that specifically says that "x" is okay but "y" isn't then most biases would allow, based off of the holy text and a societies interpretation of it. As an example maybe their messiah had some manual labor job and so that particular job is thought of as following in the messiah's foot steps and thus holy, thus the reason people still do that one specific thing by hand when magic would do it easier while still using magic for many other similar tasks. This does imply a particularly powerful church if everyone does things the hard way just to keep with church doctrine, but a powerful church is accurate to medieval time period. **Mages are specialists** You could say that magic is so hard to learn that a mage needs to specialize on very specific and exact set of abilities and spells to do anything useful. As such a hand full of 'standard' mage specialties will exist, being good at the few spells that are most needed and highly payed, with no one learning how to do other spells that aren't worth specializing in. More importantly a mage can not generalize his specialized magic to do much outside of it's specific intended use case. Once you have that then you only need to look at the hand full of common mage specialties and work to make sure none of them are game breaking. For instance maybe a mage specializes in sensing the wind and (slightly) controlling the winds who will work on a large boat helping to propel the boat to it's destination. Say he doesn't create wind so much as redirect it in the direction he wants (conservation of energy!) and has decent but not exact control. He could be quit useful on a boat, helping the boat get to where it needs to go much faster and avoid storms, but he can't create winds so powerful as to push people around, or so focused as to move items at a distance, and he still can only work with existing winds. Effectively he is really only useful at assisting wind powered tech like sail boats. Now you need to ask what it does to your world to have boats travel faster and somewhat more reliably (and this is a non-trivial change to your world! still lots of world building comes from it), but you don't have to put much though into other affects of magic because this is really the only thing wind mages can do well enough to be worth doing. This does offer an interesting story premise of having a mage who does generalize specialized skills to unusual use cases. The creative 'guile hero' who lacks strength but uses what limited abilities he has to maximum effectiveness is a standard and successful trope someone may wish to try writing. Though if one does go that route remember anything a single intelligent person can come up with on the fly has probably been thought of by *someone* in society in the past, so be careful not to come up with any innovations that are too effective or people will start wondering why it hasn't become standard yet. **Mages are rare** One common trope is to make people able to work magic rare enough that they don't significantly change the world. Perhaps a mage could move some supplies form point A to point B faster then someone can carry them with a cart. However, if you have few mages and their all busy maintaining your key palace spells and doing other more 'glorious' work it may be that you still have people using horses and carts most of the time. You can make your culture mostly fit simply by limiting the availability of alternatives. This is a double edged sword. It keeps your peasant life standard, but since your nobles and king are rich their have a mage or two on staff, so your have to put some thought on how it furthers the divide between peasant and rich and how the rich employ their mages, but it at least limits the scope of your changes somewhat. If you take this trope far enough, with mages sufficiently powerful and rare, you get into the question of what happens when one powerful mage goes rogue and tries to use his power to force others to do what he wants; since he is so much stronger and there are not mages to counter him. Of course one easy counter to this is a knife to the stomach, even massive power is not very helpful when anyone can kill you before you cast a spell if they get close and your not 100% vigilant. In fact this is likely the honest answer to 90% of rogue mage problems, that a solitary mage, for all that he can cause devastation when focused, can never be strong enough to protect himself from reciprocation if he starts abusing his powers too blatantly, someone can always knife him in his sleep unless he has a major power base/country backing him and offering protection. Thus most mages, even if massively powerful, will either work within the law or stick to subtler bullying and manipulation because if they draw the anger of the king/country they will not be able to stay vigilant enough to defend against an entire country focused on prosecuting them. You can also use counter-magic tricks as mentioned earlier to address rogue-mage problems. **Limit magic Power** You already mentioned this, keep power limited so that magic is not too massively powerful. However, power does not just mean raw strength, ie how much does it break conservation of energy. Power also means control. You can limit effectiveness of mages this way as well. Using magic telekinesis to pinch an artery to assassinate someone may not work because no one has that level of finesse. Perhaps a mage *could* produce a fireball hot enough to roast a half dozen men, but it's going to take him so long to do it that he's likely going to take an arrow to the gut (or knee?) long before he pulls it off, making it impractical to use. Maybe fine magic require extensive focus, so that if you want to prevent someone from doing something like your needle trick you just need to distract them, they may be able to use less subtle magics easier but fine magics are hard to do without the support of everyone around you. Combining a few of the above options together, the "net magic" of your world needs to be limited. That means the total ability to modify things using magic should be only so great. You could spread lots of power near a few people, or a little power near almost everyone, or some combination with lots of week mages and a few breathtakingly powerful ones. However, in the end the total available magic a society has to work with should have an upper bound. [Answer] One possibility would be to strictly enforce energy requirements (on a "realistic" level). If a mage needed to provide all energy for a spell, and the energy were something on par *with the energy required to do an effect in the first place*, any large-scale effect would be crippling. For instance, a mage who wished to "simply" telekinetically lift an object would have to exert the same energy as someone who physically lifted that same object. (The serious student with a more physics-oriented mind could start talking about potential and kinetic energy - but even if you wish to avoid that, most people can easily visualize how much effort it takes to lift something.) A normal mage could "effortlessly" lift or throw a baseball - but a person would be difficult, and a car would be nearly impossible. Likewise, a mage who wished to boil someone alive would have to exert the energy required to raise the heat - and the bigger the object to be heated, the more energy it requires. Something like spatial magic is going to be more entertaining - but given that a "true" teleport likely violates conservation laws, you could simply make that not theoretically possible. (You can apply the same argument against time travel magic.) Of course, you still get to worry about some of the more interesting questions - such as reading minds, or scrying over large distances, or predicting the future... In those cases, there might not be an easy real-world analogy. Even then, you can hand-wave that they are similar to some realistic effect, raising or lowering the energy required to suit the needs of your story: perhaps mind-reading someone in visual range is on par with lifting a 20 lb. object. [Answer] # It's All About the Benjamins Although many folks will tell you to mind the *physics*, I will instead suggest that you should mind the *economics*. Start with the assumption that mages will not form the 1% of the 1% and own 99.999% of the wealth, and think about what kinds of restrictions need to be in place to guarantee that. If you succeed, I think the physics will take care of itself. In fact, there are all kinds of ways to limit magic which makes it economically balanced. An absurd way is to say that all magic spells require the caster to be holding a semi-rare toad in the left hand, and that the toad is consumed in the casting of the spell. Now magic is limited to the toad population, and it is literally possible to make magic extinct in that world. Of course, you need to make it impossible to generate new toads with magic, but that's just the "don't print money" rule. # Universal Currency The one currency common to all men is time. Anything which consumes time puts finite limits on the amount of magic which is possible. If the magnitude of a spell is proportional to the time required to cast it, then folks will only cast powerful spells to do very effective things. And by "magnitude", I mean: "the degree to which it breaks the rules." You want transmutation, so that you can turn lead into gold? Fine. Figure out how much energy it would take to do that with science, and convert the energy into a spell-casting time which makes this economically infeasible (i.e., make it more cost-effective to mine the gold than transmute it). If it would take a mage 3 days of continuous effort to transmute a 1 oz. nugget of gold, at risk of permanent long-term health effects, good luck finding mages willing to be your private gold foundries. # Mundane Currency Of course, you don't need to use time as your currency. Many magicks require the use of rare reagents to cast a spell, and this naturally acts to limit supply. You want me to launch giant fireballs into your enemy's castle? Ok, I will need 10 feathers of the Great Roc on Misty Mountain (don't complain to me that only 3 of them have been seen in the last decade!), 7 jade stones the size of my thumb, a perfect black lizard's egg (no spots), and the unbroken molt of a giant river snake. What's that? You have 3 castles you want to burn down? Well, you better get collecting, then!!! Yeah, maybe a few catapults and battering rams *are* a better idea for the smaller castles, genius! # Casting Focus is, of course, one of the most common tropes in the video game industry: that casting a spell requires focus, and the bigger the spell, the more focus it requires. This combines both a time element and an "environmental control" aspect. That is, you can defeat a mage by tickling him with a feather. Sure, he could boil your brain with telekinesis...if he can only concentrate long enough while you tickle him! An advantage of this system is that mages can differentiate their power by practicing focus and the power of a mage will be scaled by how much distraction they can filter out. A battle mage will need to be able to ignore a very lot indeed to cast spells in the midst of battle (but would still need to be protected to avoid direct interference with spellcasting). In some systems, the act of casting requires precise movements. In FullMetal Alchemist, it requires the drawing of symbols. The act of spellcasting itself can be used to limit what is possible. FMA had a rather liberal system which allowed the kinds of actions which are "world-breaking", in your sense, but that lack of discipline is not at all forced for every system. # Conclusion Basically, any rules you like can be tamed with the appropriate costs put into place. Just ask yourself: "How can I become a Warren Buffet Mage with this magic system?" If the answer is: "Not very easily at all", then it will probably work for your story. Otherwise, add handicaps until the marginal utility of a mage is just a little higher than a well-trained knight, and you will be well on your way to success! [Answer] One way to limit magic is to give it a very limited range. Say, you cannot apply it over a distance more then twice your body height. That would certainly disallow the arrow scene, and also quite a few other scenarios like just teleporting directly from your own castle into the enemy's fortified castle. Next, make it so that only very few people have the ability (you need to be born with it, even though you then still have to learn to use it; only few people are born to have access to magic). This makes a traditional fortification still quite effective, as while a single mage may just move through, a full army cannot, unless they go all through the same spot near the mage (and that's easy to defend against, as they basically have to enter one after the other). Third, certain materials (typically iron) are magic resistant/blocking. So you can fortify not only against physical force. Just add an iron layer to your fortified wall, and even the best mage won't be able to cross it. And the knight's iron armour not only protects him from lancets, but also from magic attacks. And your treasure is safe from magic stealing if it is inside an iron chest. I think those three rules should already be enough to prevent magic to be all-powerful, and still allow enough magic to be used for interesting things. [Answer] One proposal I haven't seen for dealing with your "boil the brain" idea (I calculated an answer to the energy requirements for that spell in a different question) is that magic is based predominantly on will and animus. Thus, it is far harder to effect an already living entity (which has its own magic like life force) than it is to create a magical effect upon an inanimate object. To extend this point, your will to burn me is directly countered by my will to NOT explode in a fireball. That contest of wills, like locked lightsabers, is usually not resolved by "pushing through" but by disengaging and looking for a new opening. Thus, a magical sneak attack from an unexpected angle (dropping a boulder) is more likely to be effective than a direct attack. Similarly, the mere existence of an army defending a castle from intruders crafts a blockade against teleporting into that fortress. Another issue to solve teleportation is to make it intrinsically risky and "wibbly-wobbly." Sure you could march an army through a portal, but without a friendly mage with a corresponding portal and beacon on the other side it would be VERY risky and you might get trapped inside the pocket dimension. And who says teleportation is instantaneous? Maybe it's just the equivalent of "flattening out" the mountains and valleys. You'd be marching the same functional distance but on flat land, making transport of goods easier but not necessarily faster. Regarding the issue of WILLFUL teleportation trade, then you've basically created a society with a large economic surplus due to safer trade and faster communication. So? We've got courier services now and the internet. It will make diplomacy interesting, since you might "fake" an alliance to gain access to their network of portals... or turn on your allies in the middle of the night with said portals... [Answer] The most basic way of controlling it, is not to let them just wish for stuff. It is fairly common for magic to be arcane and clouded in mystery. If the way magic works is: you do X, Y, and Z and you get the desired effect. And if you do Z, X, and Y either nothing happens or you die, then nobody experiments. The point is, if it's just recipes that folks follow, but do not understand the cause and effect, then it really does come down to: they never think to do it otherwise. There is plenty of support for than in history and literature, and some good stories about that one guy who figures out how to experiment without killing himself/understanding the danger. If the only spell that anyone knows is a fireball, then nobody can cast a "microwave your brain" spell because there isn't one. Maybe until our hero invents it. ;) [Answer] Here's another approach often used: embrace the fact that magic is OP and can break the world. In fact, magic DID break the world. What's left of the world is rebuilding. Magic is viewed with suspicion. There are a few fragments of magical knowledge left, but not enough to form an overarching theory. You find a glowing sword here which seems to kill people who touch it within a week, but no explanation why, or how to protect yourself; a bag of runes that has a different effect depending which two runes you pull out; whole libraries with scrolls of recipes for common spells, but no understanding of the language they were written in other than understanding how to read it phonetically to get the right effect. Scrolls are easy enough to copy, and experimentation has allowed people to label most of the scrolls, at least where the effect was immediate. Those who can memorize the incantations rather than read them are at an advantage. Even these dregs of power are enough to make mages more powerful, but not indescribably so; only like someone having access to modern technology in medieval days. Eventually, with research, the historical levels of magic might be reached again. Many are trying to, but many more are trying to stamp it out entirely to prevent history from repeating itself. Entire great libraries have been destroyed in this pursuit. Researchers regularly get burned at the stake. [Answer] # Sphere of Magical Influence (SOMI) Distance is a factor in virtually every magic system I've ever seen (from the Force to Harry Potter), but one for which the rules usually aren't defined (or are simply downright arbitrary), which is what leads to many of the issues you mentioned. If a person can teleport down the street, why not across the world? If they can transmogrify a rat, why not a human? We want a system that allows flexible use of magic, without poor excuses for why certain things can't be done. Lets consider magic in this world as an energy system constantly radiating out from every person (like an aura) where the user can manipulate things within that field depending on strength of the "[signal](https://en.wikipedia.org/wiki/Radio_wave)" at a point. This can adopt aspects of the existing laws of the natural world to help us work limits into it in a natural and sensible way. For example, consider the [Inverse-Square law](https://en.wikipedia.org/wiki/Inverse-square_law), which in simple terms states that as energy spreads out from an object, it's strength/power at a given point is inversely proportional to the square of the distance from it's source (it gets significantly weaker the farther you go). This is one reason why the signal degrades as you get farther from a [WiFi](https://en.wikipedia.org/wiki/Wi-Fi) hotspot. In a magic system, you could use this to say that the effectiveness of the magic diminishes the further away the point of focus is from the user. What might be a fireball in your hand might only be a spark at ten feet. What range is "good" could also be affected by how much power a user can amass to put into it (be it by charging, proportional to mass, or just different power potential between users, all depending on how your power is derived). This works particularly well with another aspect of signals: [noise](https://en.wikipedia.org/wiki/Noise_(signal_processing)) and [interference](https://en.wikipedia.org/wiki/Interference_(wave_propagation)). If you've ever used a [walkie-talkie](https://en.wikipedia.org/wiki/Walkie-talkie), you know only one side can talk at a time, or else you get static. That static is caused because the signals overlap and drown each other out. Since every living person is always naturally emitting a magical field (SOMI), this means that the closer to them that you focus your magic, the greater the diminishing of the effect, and at the point that you try to cast near or directly on them, it becomes completely ineffective. This would prevent you from just teleporting right behind someone and stabbing them in the back or setting their brain on fire, but wouldn't stop you from just creating a fireball in your hand and then throwing it towards them from a distance. ### You could also use other aspects of signals to extend your needs: * The density of an object/material would weaken the strength of the SOMI, and certain materials can be dense enough that magic cannot penetrate. + Cities/buildings would be protected by either thick walls, or walls containing dense materials like lead. + [Faraday cages](https://en.wikipedia.org/wiki/Faraday_cage) can be used to isolate magic between the inside and outside. This would allow for safe prisoner containment, protecting an armory, or other special uses. + Armor would be dense enough to at hinder a user's SOMI to some degree, which would make lighter clothing more magically beneficial. * Magical [amplifiers](https://en.wikipedia.org/wiki/Amplifier) can direct a persons SOMI in a particular direction, increasing it's range and effectiveness (like how a [satellite dish](https://en.wikipedia.org/wiki/Parabolic_antenna) directs the signal better). The larger the amplifier, the better the effect, but this also makes good ones impossible to carry around with you. + Certain magic like teleportation would be much more useful with an amplifier than it would on it's own, giving a range of miles instead of meters. Because they would have to be rather large, you would only be able to find them in towns for use in long distance travel. + Powerful enough ones could be used as weapons of war, where a person's SOMI could be amplified in a particular direction to be powerful enough to possibly punch through another person's SOMI (or a wall). The size needed makes moving and aiming them difficult though. + Small amplifiers could be worn on the hands to allow for directional casting with improved range or secrecy (unlocking a door with specific magic without broadcasting the "key" all around you), but might also be regulated like weapons would. + If you want wands to exist, they could work like directional [antenna](https://en.wikipedia.org/wiki/Antenna_(radio)). Wands could either be required to focus any magic at all (no wand means no focusing your SOMI on a point in order to do anything useful), or optional, and just increase the power and range in that direction. In either case, they would likely be regulated to some degree as well. * Multiple mages can "synchronize" their fields, allowing them to cast stronger effects than a single person could cast alone, or otherwise to cast effects on each other such as healing. + Due to the inverse-square law, doubling the number of people would not double the effective range (range would only increase slightly), but would increase the strength of the magic significantly when closer. In theory, enough people in sync could overpower an individual's SOMI when at close range (good for judicial systems to carry out punishments, and encourages working/traveling in groups with people you trust, but also leads to the formation of gangs). + Synchronizing requires practice and a familiarity with the people you are working with. The larger the group, or the more noise from other people "out of sync", the more difficult it is. + You cannot cast undesired magic on someone you are synced with. Syncing requires having the same focus/goal, so to do so would by definition put you out of sync. * Because the SOMI is a field, it is detectable. People (or machinations) can detect the fields of others, and those with the training and/or familiarity with the person can recognize their distinct "[pattern](https://en.wikipedia.org/wiki/Frequency_modulation)". This means while you could make yourself invisible or transform into someone else in order to avoid detection, there's still risk involved. + If you have synced with someones SOMI before (or been around them enough to recognize it), you could imitate it like you would while syncing. This requires the training to do so, and the effectiveness varies. + You can also "turn down" or "shut off" your own SOMI. This comes at a risk, because while it makes you less detectable, it also makes you vulnerable, since someone else's field can now reach you and have an effect. This may be desired in a friendly situation to allow someone who can't sync with you to still heal or effect you. With enough training, perhaps you could even limit what directions you SOMI is "broadcasting" in to a limited degree. + A person could also "constrain" their SOMI, through the use of clothes laced with dense material to create a sort of "personal Faraday cage". This reduces detection without leaving them defenseless and offers greater magical resistance, but at the cost of their own SOMI being blocked or degraded while wearing it (and thus ability to perform magic). These are just a few ideas I've come up with built around such a system. Other factors would need to be considered such as where power is derived from, what sort of magic can be cast, and if people have different magical potential can vary. But at the very least it should provide a solid foundation for a balanced magical system. [Answer] Why build castles when artillery strikes cut right through the walls? Answer: the artillery didn't exist when the castle was built. **Novelty** is thus one possible answer to your conundrum. Either magic is so new, or so rare, or so foreign, that 99% of human life is unaffected by it (yet). Maybe it existed as a form of entertainment, with nothing more complex than cheap parlor tricks, until last year when a scholar took a look and realized the spell that allows you to light candles can be turned up to 11 to produce a fireball if you pronounce it wrong. Cue monarchs pouring funding into research to discover how to harness this strange power, with no two nations discovering exactly the same things. (*Will* it change the world? Yes. But no one understands it yet, and all the amazing things you might be able to do have not yet been discovered, or are only beginning to have their ramifications play out.) This is not without precedent in our own world. How many people had watched how many apples fall to the ground before Newton figured out the rules behind it? See the web serials [Ra](https://qntm.org/ra), [Worm](https://parahumans.wordpress.com/table-of-contents/), and [Unsong](http://unsongbook.com/), which all use this idea of magic (or superpowers, in the case of Worm) being discovered in the last 50 years, and describing how the world changed. [Answer] ## Contact The mage must be in contact with the item being affected. This still allows all sorts of fun, mages can still throw fireballs (technically starting in contact), launch rocks etc. but it gets more complicated teleporting an army. The mage can teleport himself, no problem, but can he teleport you? He's touching you but if he gets it wrong he could do any of the following: 1) Teleport only your skin 2) Teleport you without your clothes and weapons 3) Teleport you without your stomach contents In all these cases, while use of magic carries great advantage, it also carries equivalent levels of risk. ## Balance If something gets hotter, something else must get colder, for everything that goes up, something must come down. While this doesn't have to be strictly true, it's certainly easier if it is. If the balance is wrong and the mage not up to it, the imbalance dumps straight into the mage. ## Consequences No matter what you do in a magical world, it should always have the option to come back and bite you. Courtesy of the great Pterry. > > Seven league boots, as has already been > intimated, are a tricky form of magic at best, and he remembered too > late that the utmost caution must be taken in using a means of > transport which, when all is said and done, relies for its > effectiveness on trying to put one foot twenty-one miles in front of > the other. > > > [Answer] ## Difficulty and Counter Magic The first step is to make magic harder. Not necessary less powerful, but let's say a mage can do less of it, and needs more skill and concentration. This should be enough to eliminate things like trade, except for very valuable goods. But why aren't assassins being teleported into your throne room? That is surely valuable enough. The answer is various forms of Counter Magic! A spell is being used to prevent this from happening. Of course, it would be much too expensive to cover literally your entire country in counterspells, but you can at least cover all your cities. A powerful enough mage can overcome a weak mages counterspells, but in general the counterspell caster has a much greater advantage. Additionally, you can imagine counter magic armor, that blocks certain types of magic. Although you could throw a magic projectile at someone and it would hit them, it likely couldn't come back. Likewise, although you can throw fireballs at people, you can't actually form the fireball inside them. In general, it would be an arms race. If a use of magic "breaks the system", enemy magicians will quickly develop a countermagic to stop it. [Answer] Ultimately the limitations you design for your world must be determined by what you want with your world. Do you want a magic system where mages can boil people's brains out from two miles away? You can create a system to do that. From what you said however I'm going to assume you want a magic system where mages can do interesting things, such as throwing a stopping an arrow, or flinging someone across a room without allowing them to just stab out someone's eyes with telekinesis. While there aren't really general guidelines for this, one of the best ways to limit a magic system is to create hard physics rules for how magic operates. I'll give a simplified example of a system I used in one of the past games I ran. Mages were able to exert a gravitational force on any non-living object that was directly proportional to the object's mass. (Note that since objects are just a collection of smaller pieces there was no hard rule as to what defined an "object"). The larger the object the more energy it took to do so, and a magus could only push directly away or pull directly towards themselves. To prevent someone from stabbing a person's eyes out with magic, you could not directly push on a living person, as all humans exuded a aura that prevented magic from directly affecting them. Additionally, since the acceleration of an object was based of an equation I prepared, and couldn't be accelerated at a faster rate by adding more energy, you couldn't accelerate a very small object to massive speeds. The risk in defining magic systems with incredibly hard rules such as this is they often end up being very constraining. This system only worked well in the game I ran because all the players had very comprehensive physics educations, having degrees in fields where they studied physics, or in the case of one of my players, having experience as a researcher and professor at a university. For us the system worked, because although it was constraining, each player had to think about how to use magic to achieve their goals. You couldn't simply throw a fireball and expect an enemy to die. You had to think about how to use your powers creatively, while avoiding their use of their power. However, it is understandable that not every player would appreciate such a detailed magic system. Especially since in order to work a magic system like that, we had to define certain equations that governed every aspect of magic in definitive terms. Another limitation you could place on a magic system would be to require that all magic must originate from the magus casting it. What I mean by that is if a magus throws a fireball, the fireball must originate from his fingers. Therefore removing the possibility of boiling someone's brain from a distance. While in this example there is still opportunities for a magus to innovate and do more efficient things than throw a simple fireball, do you really want to stop all innovation? Ideally I like to allow my players to innovate with my magic system, however what I hope to avoid is allowing them to innovate in ways that completely breaks the game. Apologies if my grammar or spelling aren't very good. I'm still learning English. I know this doesn't give you a definite answer, but hopefully this gives you some ideas so you can start to form a magic system that works for your game. [Answer] One possible solution is "just" to make magic costly: * You wont break trade if to teleport someone over 10km you need to sacrifice a human in a complex ritual. * You wont have magical wars if casting a single fireball cost as much money in reagents as hiring a complete company of mercenaries. If the more your magic has an effect on reality, the more it will cost (be it in blood, money or sanity), then the system will balance itself. And this would naturally imply that altering reality cost more than keeping it intact, so protecting a castle wall with wards against magic would be "cheap", at least far far cheaper than the magic needed to destroy it. [Answer] Realize, that based on the constraints you have named, that you will fail. Seriously. You smarter than Einstein? because he tried to define physics in the real world and it doesn't hold up. Author after author after designer after world builder all run into this because the question is too big. "How do I make a perfect magic system from the start?" isn't a realistic goal. As numerous other answers dig into, this is an actual career for companies that do MMOs. Realize you will miss something. Realize that if you make it "big" that you didn't miss something for years and then with thousands of people that like to pick magic systems apart... you will have missed *a lot* of things it turns out. Once you wrap your noggin around either redefining your problem to be solvable or accepting that you have created an unsolvable problem and you are trying anyways because the journey of trying to solve it will be fun and rewarding... Now you can make progress instead of getting stuck or stopping each time an issue comes up. Start at the end. What do you want magic to look like and how should it work? What kind of rules need to be in place to make it so? eg: Portals would likely never have been used militarily before someone started working on anti-portal magic just like it is here with military advancements. Maybe the inventing nation got to use it a few times before someone came up with a counter like the US did with nukes. (Didn't take long for countries to build nuke bunkers). Realize you will miss something again. Try anyway. That's pretty much all you can do. Seriously. Magic is basically a new type of physics with the way you want to solve it. Nothing wrong with that, but you are asking a bigger question than you might realize. [Answer] I will answer based on the following assumptions: 1) Magic is relatively common, maybe 1 in 100 have it. 2)Most mages have a similar power level, I would suggest mid-level but it is up to you. My theory is that for every piece of magic Mage Bob does Mage Alice will counter it rendering magic useless. For example, Bob teleports into treasure room. Alice sees Bob and teleports all the treasure to a different room. Bob doesn't know which room so has to leave. For every magic attack there is a magic defence. The only way to win a fight with magic is to use something your opponent hasn't thought of. This is now a situation similar to cyber security. Criminals find elaborate hacks which are then blocked by security. [Answer] I'm not sure if anybody gives a crap so I'm not going to bother you all with reading a lot of text, but I suggest checking out how it's done in Souls series games. To me, it seems pretty reasonable. A quick general overview of how getting a spell to use works: * You find a scroll that teaches you how to cast certain spell; * You get enough Attunement stat to put that scroll in your usable inventory slot; * You get enough corresponding stat (such as Intelligence for Magic or Faith for Miracles); * For each scroll attuned, you gain a certain number of castings of given spell; * Scrolls are not used up because of casting, and castings regain after resting at a bonfire. Developing new spells is explained as dedicating a lot of your time and energy (which often means studying a spell your whole life to develop it), and using it requires certain study to have place also (for NPCs, as it's simplified for protagonist to just leveling according stat). In return, the spells are really powerful and useful, but not really world-shaping. Such as, you can enchant your weapon, throw fireballs, magic and lightning bolts around the place and do many advanced things coming out of it, but it's pretty limited in quality AND quantity. As such, it's been hinted in a couple of spells' descriptions that they challenge the very limits of skill of even the most dedicated scholars, and they have taken some ingenius scholar's whole lifetime to create, and yet it can't do so much as worldshaping. Of course it's entirely possible, but it hasn't happened ever, which easily explains the limitations of magic lore-wise. That's just the setting, and it's reasonable, and I don't think anybody would have a problem with that? [Answer] Well, even if the magic is "broken" or "imbalanced", what does that matter? There are many technologies that you could consider broken. * What good is a wall around a city in today's time when we have aircraft and powerful explosives? * Why would you bother owning a horse when you can travel by automobile or use some type of powered farm equipment? * Why would you bother sending a letter when the internet and strong encryption exist? * Some day it will probably become the norm to own a 3D printer and make what you need in your own home instead of travelling to the store to purchase it. * Why employ factory workers when you can employ factory robots? Those are just a few examples of the type of era-advancing technologies that magic would be. I think that it is less important to think of how to "balance" magic (what does that even mean outside of a game?) and more important to accurately reflect in the society how magic has changed it. Cort Ammon had some good examples of this based on your question: > > Magicians have the ability to boil your brain at a distance of 10 feet? Don't be surprised when society politely stays 10 feet away from anyone who looks like a mage. Don't be surprised when royalty issues clear rules to murder anyone who foolishly advances to within 10 feet of the throne. > > > It's the same way how when you pass someone holding a gun, a device which is totally over powered in that it can end anyones life by being point at your head while a button is pressed, you don't *necessarily* get nervous, but if someone points one at you, or begins to get visibly and irrationally angry, you most certainly will get fearful. --- I think there are two approaches, either you can decide what magic is like and figure out how the world should change or you decide how you want the world and make magic such that the world would be like that. So if you want a place very similar to medieval times with walled cities, clearly you can't have teleportation (or there needs to be some sort of enchantment that people can't teleport through that can be put on the walls). If you want people to be able to have some trust that their brain won't be boiled then you need to make there have to be some sort of visible indicator of magic, like a tattoo or wand. [Answer] Magic spell is a "request" or "message", that will or will not initiate some chain of events. Like an any "message" spell must to reach some "execution agent" or "behavior". At next step "agent" must or must not recognize some instructions from received "message". If "agent" will make some actions, then some energy will be consumed. Also some kind of "agents" or obstacles may "guard" the final target of the spell from any actions provided by "agent" that receives initial message. So, we have "agents", "messages", "obstacles" and infinite combinations for prevent any sort of action in this system. For example: Agents: ether, spirit plane, gods, elements. Messages: spells, magick place events, item events, etc. Obstacles: ether waves, visual obstacles, another agent actions, counter spells, bad reputation, gods hate etc. [Answer] The magic police... An alternative way of dealing with magic Instead of finding ways to limit magic, and there are some awesome answers for ways to do that, how about having a police force. I'm thinking, we have guns, machine guns, missiles, atomic bombs, germ warfare, today's society has enough firepower to smash the world several times over, so why hasn't it happened? Think of how we manage to live with such frightening power, and just replace guns with wands. Getting back to the police, they are organised and powerful. A single Mage may make a stand, but he'll be taken down eventually. Think of surveillance of rogue wizards, personality checks for training in the dark arts. And what about the army? An army of wizards protecting the country, hunting terrorist mages, undercover mages. They'll be mercenaries, bodyguards, private protection, etc specialising in counter magic. A lone gunman could kill the president, or a lone wizard could kill the King... Both scenarios are possible, and preventable. But mostly, people will go about their business knowing the law keeps things safe. [Answer] **thermal magic rules** -Mages can feel the collision of limited rough pure elements like hydrogen and methane molecules close to them when they focus -Mages can alter the collision of these limited elements to cool or heat them This explains why a mage can throw a needle of ice or a ball of fire but can't boil people or transform the earth in a mass of magma and fire. -Magic can't directly balance temperature therefore mages can't cause an earlier heat death of the universe **Kinetic magic rules** -Magic can lift and move matter under 10% speed of sound This limits mages from using bullets that could penetrate castles walls like they were made of water, but they could move vehicles as fast as modern cars. -Kinetic magic can't split molecules This doesn't let mages transform mountains or people in a bunch of atoms and doesn't let them cause atomic explosions at any time they want. -Kinetic magic can't control acids and salts. You don't want your mages to destroy the genetic code of their enemies or simply create cobalt bombs , right ? -Kinetic magic force is based on the caster's brute strength If a mage can't lift a pencil with hir bare hands ey wont be able to do so with hir mind power. **Magnetism magic rules** -Mages feel pain every time they cast a lightning bolt, the stronger and further the more painful it will be. This way your mages can't shoot a lighting at people from the other side of the world or they would be paralyzed by pain for days or probably even die. -Mages can create magnetic fields only in hot temperatures like anything under 15° C will be extremely weak. This gives people who live in cold places a protection against those types of mages -Magnetism magic can't speed up light but can move it away this way your mages can't control time but can become invisible or make other things invisible -Magnetic fields can't affect global gravity If your mages want to suppress the world to a single point and then release the explosion they can't. -Magnetic fields have an effectiveness of just force of gravity of earth's surface. This way your mages can't simply make people explode from the inside or split them in two with the though. **Biologic magic rules** -Mages need to see the bio-matter they want to control. This way your mages can't cause cancers to internal organs or simply destroy or cure them without opening the flesh of the victim. -Mages can only control the way cells act but can't change them internally. This way mages can make a person blind but can't make their eyes melt or explode by changing carbon with explosive compounds ... -Powering effects to cells can be permanent while harmful effects last only few minutes. This way mages can cure a cancer permanently but can cause one only for a limited time. -Biologic magic only work with cells of the same specie of the caster. This way mages can make people weaker or more resistant to a virus but can't enhance said virus or create a new one. **space magic rules** -Wormholes instead of teleportation Teleporting a person consists of killing it in place and creating a clone in another place... this is simply stupid. -Wormholes can be controlled at any speed but anyone can use them. Your mages can create a portal to escape from danger directly in home and relax, but if the portal isn't closed fast enough then enemies will chase hir. -Only light and people who have clear intent to enter the portal will use it. This way your mages can create a portal large enough to suck the light and create an ''eclipse zone'' but can decide to create a portal inside people and export their organs and can't force people enter wormholes and throw them inside a volcano. Or your mages can't simply put a portal that will take all the incoming arrows and throw them back on the behind of enemies. -Portals last for only 2 minutes if the caster doesn't decide to close it earlier. This way mages can't simply fill the world with portals. -Wormholes have no limit in distance but mages have to see the point they want the exist portal and the entrance to be or at least have a memory of it. It's a pretty weak power but giving it no distance limit mages it decent and balanced. -Portals have a recharge time of 30 minutes so your mages can just use a portal to sneak behind someone , kill them and escape immediately. -Mages can close portals at any time even when someone is passing it As mentioned before mages can't force people to use portals but if they are chased by an enemy they can close it and split their enemies in piece. **Illusory magic rule** -Illusions can be of any type and as strong as possible but can't scare to death people. **General magic rule** -Every cast costs energy from breathed oxygen and the stronger the spell, the weaker a mage will feel , but the spell cost can't directly kill a mage. [Answer] The real world had magic. People believed it did, anyway, and acted accordingly. What would have been the difference in the things you are concerned about, if the magic they believed existed actually had? I don't think much, if any. The modern world also has magic. Some people at least believe in it and study it. Yes, even some very smart and skeptical critical thinkers. But the magic they believe in, like most of the historical magic (which in many cases is the same thing) is not the flashy direct magic of typical fantasy stories, films and games, nor denial of physics, but more subtle and personal effects. Not fireballs and teleportation but divination, telepathy, intuition, empathy, healing, energy work, spirit communication, (de)possession, and shifting mindsets. As for more literal overt magic and how to work it consistently into a world, there are a few workable approaches: 1) Have it be largely secret, rather than everywhere. 2) Have it be limited to a few users, who for various reasons may not to often use it overtly. 3) Have there be counters from opposing users, to balance things out. 4) Have there be counters from the magic realm itself. Maybe using magic creates a backlash or gets the intention of malicious magical entities. 5) Have there be downsides to use. Read just about any pre-modern Christian tale with magic involved, and you'll almost surely find a morality tale about how magic users make pacts with the devil that don't turn out well. Or see magic systems where casting spells has a serious chance of serious side-effects. 6) Have the nature of magical study tend to attract and/or require people with a lot of patience and/or wisdom and/or other traits that make most/all of them not munchkins looking to abuse things and/or amass power, but people who mainly want to be alone to study their own projects, and/or do other beneficial and non-world-disturbing activities. 7) Carefully limit the powers of magic to not include things that mess with things you don't want messed with, and that don't invalidate the world you've designed. 8) Choose the magic system you want, and then brainstorm what people will do with it, and ask others (especially RPG gamers with munchkin experience) to ask them how they can think to exploit it. Then trim/limit the abuses and *then* design your world as a natural consequence of those powers. 9) Have the arrival of magic at the power level you want, be a new arrival on the scene. [Answer] Society is based around actions that can be applied consistently to get consistent results. Make magic inconsistent, and society can not be based around a spell. * If a spell once discovered can only be cast once, ever, spells do not transform society beyond their immediate effect. * If the nature of magic changes over time, new spells must be researched continually and stop working before society can figure out and apply all of the cool ways to abuse them. (This is a stated property of the Mysticism school of magic in The Elder Scrolls series of games, although it doesn't happen in-game.) The changes can be continuous (spells' effects change slowly and in random ways) or abrupt, even un-creating all existing spells simultaneously if you want. * Magic itself is unpredictable (this may go well with the next point). If magic can randomly do something different from what is desired, this can limit its usefulness. Perhaps functioning like a literal-minded genie, or randomly overdoing or under-doing effects. Or doing something completely different at the worst times. If magic is created by some god or by demons, or simply has a mind of its own, it can be a trickster god which inevitably fails its user at the worst possible time. * If magic is a kind of "thing man was not meant to know" it can be not just inconsistent but, more importantly, cause madness and inconsistency in its users. So mages don't necessarily do as they are told, nor what we consider to be wise, nor do their spells do *quite* what everyone else was expecting. [Answer] # Require that conservation laws are still in effect Without this, it is possible to break nature itself in many different ways that can hardly be predicted. Some consequences: ## No transmutation between things that involves nuclear reactions Otherwise things break. Hard. My go-to example is from *Harry Potter*: with a few exceptions, there seems to be no limit to what can be Conjured or Transfigured. When you are limited to mundane objects, that works okay in-universe. But what if you transmuted something into, say, *a supercritical mass of pure U-235 with some deuterium and tritium in there?* AKA a nuclear weapon whose detonation mechanism has already fired. The resulting explosion would obliterate far more than just Hogwarts. And the spells needed to do so seem to be well within the capability of a gifted 7th year Hogwarts student. For someone like Voldemort or Dumbledore, they would be *trivial.* Granted, it’s a suicide weapon, but one could always use the Imperius Curse to force *someone else* to be the caster. And imagine if you could conjure, say, *antimatter…* ## Mass is conserved (barring relativistic effects) Otherwise conservation of energy fails. By Noether’s theorem this implies that the laws of nature have an explicit dependency on the time. That is a contradiction. ## All magic requires a power source It doesn’t need to be internal to the mage. But it *must* be present. [Answer] Many of your problems will be simply solved if you # make serious magical abilities extremely rare, and require focus. ### Transportation example Take the problem of transportation: granted, if you can hire a minor mage to haul your stuff many miles far for costs of living and some extra beer, it's going to be an issue. But if there are just 20 people in the world capable of transfering a piece of rock further than fifty feets far, there is no issue at all - they are all much too busy to care about someone's little bussiness. The possible loophole here is the capability of a single person to control a vast number of transfers - if a single wizard was capable of handling all Amazon's shipping while doing he's normal bussiness, it would be a problem again - but the usual approach is to assume the focus of a person is limited to a small number of objects, or even just one. ### Military use In the same vein, the military use of magic is limited to this extremely small group of people. And if your enemy has a one-in-a-billion wizard on board, his ability to create a portal to your castle may actually be less of a problem that his ability to outsmart you in any other field. Cause it's somehow natural to assume that magic abilities should go together with intelligence and mental abilities. This way or another, a mage is going to be just a single super weapon with their own agenda, so you don't expect to meddle with some everyday fight. ### Different levels of magical abilities While *extreme* magical abilites rare, it's not the problem if many people (even majority), have *some* magical abilities - the telekinesis allowing you to flip pages while reading a book is not going to make you a superhero. It may cause existence of some new nice inventions, like locks without a key (instead of turning the key, you use your knowledge of the internal structure of lock to unlock it with telekinesis), but most likely nothing groundbreaking. Of course this answer doesn't cover some aspects (like, why use a fireball instead of brain-boiling), but they seem sufficiently addressed by others. [Answer] One way is to stop thinking of Magic as "Science only better": It's not a simple (or even complex) set of reproducible rules, causes and effects. It exists at the whim of the gods. It takes a combination of concentration, knowledge, instinct, will, creativity from the mage to produce a spell. Why can he produce a fireball and throw it at an enemy, but not boil his brain? Not even the mage himself (or perhaps even the author/narrator!) knows. All he knows is one is relatively easy (or allows room for error) and the other is difficult. It's a very mysterious art. And as the effects become more complex or powerful, the spell becomes more difficult. Asking an army to step through a teleportal is a big request if they know that the more people that step through, the stronger the spell has to be, and the stronger the spell is, the more concentration and skill is needed from the mage, and if it goes wrong, they could end up trapped in a deep cavern for the rest of their lives, or teleported into solid rock, or their bodies just mangled or never rematerialising. ]

[Question] [ I'm just your average person. Not rich, or particularly skilled at anything. Until a few days ago, when (for a reason I can't disclose) I got some amazing superpowers: I can fly, I'm completely invulnerable to any kind of damage and lift pretty much anything. I've decided to use these abilities for good: Like a traditional superhero, I'm going to patrol the streets at night and save people from criminals and disasters wherever I find them. At the same time, I'm afraid that a villain (super or not) might discover who I am and threaten my loved ones. Luckily, those powers come with a transformation. In my normal form, I'm still a regular person. If I transform (which makes me look entirely different), I can use the abilities I mentioned above. There is no way I'd be recognised when transformed, the transformation is instant and I can trigger it at any moment simply by thinking about it. What's stopping me however is the likelihood of someone noticing me transform. Obviously I have to do so away from public places: Not the middle of the street. But wherever I go, there's always the chance that someone will notice. If I duck into an alley or a phone booth, there's no way to guarantee that someone from a building across the street won't have noticed that a regular person went in and StackExchangeMan flew out. Or my neighbour would notice that SEM keeps flying in and out of my windows and be suspicious. This becomes especially difficult given that CCTV is everywhere; if the police (some of which could be corrupt, or simply not like vigilantes) check all the cameras around where SEM last appeared, they may find a good view of the entrance to the alley I used. Is there any place in modern times where I could transform completely unnoticed? [Answer] How spectacular is this transformation? Can it be hidden if you simply wear a hoodie and nobody happens to see your face? Or, say, does your body suddenly become twice as big with muscles or something? Places that are less actively surveilled include public parks, bedrooms, and restrooms. In addition you are trying to pursue anonymity by nobody seeing you, but modern anonymity software usually tries to get you to "blend in with a crowd" of other network traffic: you may prefer to change in the bathroom of a local mall, for example, where you can go in wearing a suit and carrying a briefcase, and then pull out a hoodie from your briefcase, stash the case itself in the ceiling tiles (because you can fly!) and walk out incognito in a hoodie. Okay, so "malls" are a little rare, but on busy nights you can probably do the same thing with bars, go in, order a drink, pay up, use the bathroom, change, leave in a hoodie, people who recognize you out on the street won't know which patron of the bar you were. Or you may want to actively be mistaken as a homeless person: thick dark clothes, big backpack, etc. This means that people will mostly avert their eyes from you, but it also makes it less unusual when you go where homeless people go. Remember, homeless people will go places like under bridges where police are not likely to look. Near my apartment there's a big storm drain coming out of a hill; you have to sneak behind a guard fence to get there but homeless people like the space because it's open and sheltered from the elements (when the rain isn't flushing out through it). You change from homeless to superhero there, fly around the hill, solve crimes, change back to homeless when you return. Some alleys may not have many windows on them but they may still not be blind: you may be able to enter in one way, transform with relative privacy, then exit the other way. Similarly, you might just drive (or even live in!) a big van, that would give you some protection. Keep a reflective jacket and hard-hat in the trunk and people might just assume that you're an official worker if you pick up a manhole cover and head down into the sewers, no surveillance there. Come out of a different manhole and you'll be known everywhere as the smelly superhero who busts out of a manhole to save the day. [Answer] It's not villains you need fear, it's your own government. And in the modern world you're ***screwed***. There are more cameras watching us than ever before. Heck, if a spy agency realizes where your efforts are concentrated they can simply start spying through everyone's cell phone cameras, etc. and they will end up tracking you down sooner or later (my bet is on "sooner"). I would recommend keeping your head down, or otherwise moving to some remote country side where there's little to no surveillance because I honestly can't imagine *any* government passing up the chance to study and or dissect one such as you. You'd not only represent a major opportunity to learn how to potentially "manufacture" super soldiers, but also a threat! What if you don't like their policies and decide to take out some politicians? Who would be able to stop you? It's simply too risky to allow you to run around unchecked. Now, if you've got such an underdeveloped sense of survival that you still want to go ahead with being a superhero, then you should probably use some unobtrusive alley to change, and then fly straight up. However, many businesses have hidden cameras watching their back doors, and there might also be windows facing out into these alleys, and people might see you, or record you. Basically, every time you change, you take a risk. And sooner or later you're going to get recorded. Probably "sooner". Instead, you should probably move to some remote area in Mexico, or Columbia, and start taking out drug cartels. Live in some village where there's no surveillance, fly up high over the jungle, spot drug labs and wipe them out. Or simply attack their villas with impunity - after all, you have no corrupt politicians tying your hands, and no laws holding you back. Keep in mind, however, that there's an endless supply of "bad guys" willing to step into their shoes, and that they might end up having access to some pretty crazy weapons. [Answer] # Amish country During the day, you are an unassuming corn farmer, or a hunter in the woods, or whatever. During the night, you retire to your no-tech shack, transform into your alter ego, and fly to the city under the cover of darkness. Patrol the city at night, then fly back home before dawn. Maybe you even have a superhero cave somewhere with all your fancy gadgets and intel center. But you *never* transform during the daytime, or anywhere near a city. If there is a disaster, then you have to go there at night, then surface and help people the next day, and then disappear. Make sure you do not regularly have contact with other people at home, so that you disappearing for several days at a time is not an issue. [Answer] ## No one location Pick out several locations - clumps of trees in a park, alleyways, abandoned warehouses, car parks, shopping malls - and vary your route between them. Muggles are pretty awful observers, after all, so you can take advantage of that. Yes, people are going to notice that StackExchangeMan flew out of a building, but they were very unlikely to have been paying any attention to LukeN when he went in. If witnesses can give any description at all, it's likely to be vague and generalised. If you can get more than one witness to disagree on what they saw, even better. If you changed in a park last time, assume that park is full of Downvoteite and had for the shopping mall. If you entered the warehouse through the north side, fly out through a window on the east side. Go in on the bottom storey of a multistorey car park and fly out through level three (not the top level, though - too obvious). But best of all? ## Don't tell anyone that StackExchangeMan has a secret identity Make it known that StackExchangeMan lives in his Fortress of Review in the wilderness of Detroit, and comes out when needed. If you have the technology to create robot duplicates of yourself, build one that can sit on a deck chair in front of the Fortress whenever you're not in action. People shouldn't even be looking for your secret identity, because even the fact that you *have* a secret identity is a secret. [Answer] Your problem is finding a place to change back to normal! Most folks with cameras aren't recording regular joes around them, but they are FOR DAMN SURE recording a superhero zooming around! Plus it is far more likely that authorities will know where a superhero was LAST SEEN in order to look at CC footage and witness accounts than the reverse. It is far more difficult to both recognize someone from CC footage and track their movements through time than media typically portrays, so a normal person rounding a corner and SEM (stackexchangeman) coming back around doesn't necessarily mean the normal person turned into SEM, they could have kept on walking. But SEM dropping into a bush and a normal person crawling out, well that is a red flag. SEM has another problem as well, his electronic signature. His cell phone, RFID active devices, BT enabled smart devices, etc. Unless those things vanish into a pocket dimension when he transforms, he is either still gonna be trackable as SEM or there will be a little pile of identifiable items left behind (that he also has to go back and retrieve, greatly increasing the likelihood of being identified as SEM). Authorities will start to create sniffer traps and hope SEM comes by. They will try to ID his electronics, collect any DNA residue he leaves behind, possibly even try to get his scent for dogs/chemical sniffers. Depending on the amount of transformation he undergoes he may retain enough facial marker consistency that facial recognition can id his non-transformed face. But in general I think most of the focus will be on where SEM goes, rather than on where he comes from, based on the assumption that while he could be anywhere when he "goes active", but will probably return to a safe place to heal, change, or hide once the threat is over. Humans are far too predictable to be able to choose truly random places to hide, so knowing where SEM goes afterwards, even if it is just a rough idea, will yield more information about him than trying to guess where he comes from. [Answer] It's a boring answer but in a highly urban setting, there are so many cameras that the only real solution to this is figuring out a few places where there are no cameras (and typically few people) and using those to transform. Society has done a pretty good job of making sure that there are few to no "private" public spaces within easy reach. If they were easy to happen across they would be be havens for crime, sex, etc. The closest thing to a consistently "private" public place in a city would be a largish park. One where you'd blend in with the crowd going in, find a few seconds of not being watched, kick your heels together, and then fly out. The main downside to this is that when there's an emergency and you need to save the city from the villian's missile bearing down on it *right fucking now*, you don't have the luxury of hiking it across town for a leisurely stroll in the park first. You could opt to have your own mobile private place. A car, for example. You'd want a van or SUV with tinted (or non-existant) windows so that nobody could see you change. The main problem with this is that if your superhero form is conspicuous (unnaturally large pectoral muscles, brightly-colored leotard, etc), someone is going to remember seeing you step out of a white 2006 Chevy Tahoe with a bumper sticker that says "My other car is a broom" sooner or later. Third-best option: trusted associates. You bribe/coerce people who own or rent property around town to let them use your space for changing. Walk into the grocery store, exchange a raised eyebrow with the cashier, into the back room, up some stairs, *presto chango*, fly off the roof and beat up some evil. But what happens if (when?) those associates betray you? They could become informants or even ensnare you in a trap once they realize how much you are worth to someone else. As others have already mentioned, the cover of night provides more options, but perhaps not significantly more. Finally, changing *into* your superhero self is often going to be easier than changing back into your normal self. If you do a particularly good deed and become a media spectacle, expect the local news and police to suddenly become amazingly interested in trying to figure out who you are and what you do in your non-heroic off-hours. They will have undercover agents, spotters, spies, large cash rewards for tips, even helicopters to track your flying habits (unless you can fly *very* fast). Don't think you're going to be allowed to fight some crime, bask in the warm afterglow of victory and then waltz off into the sunset unhindered by adoring fans, curious reporters, and angry police. You better be damn sure what you're signing up for here. [Answer] **Go for a hike every evening.** Pick an unpopular portion of woodland near your home. Hiking is perfectly normal, and as it gets dark less people will be out on the trails. Find a place in the wilderness to stash your average-joe clothing and reveal your spandex undersuit. Fly up into the night under the cover of trees, darkness, and seclusion. Eventually gain enough money to get a house next to a lot of woodlands, and install secret tunnels from your home to various secluded areas of the forest. [Answer] You would want to use the same places criminals tend to use to commit crimes, for the same reasons criminals use these places to commit crimes - the lack of video surveillance or reliable witnesses that allow them to get away with their crimes would allow you to get away with your transformation. Abandoned properties, no-tell-motels, drug dens ("crack houses", etc.), an out-of-sight potion of the local skid row, or just the middle of nowhere would all do just fine. I would probably prefer a drug den or no-tell-motel, as it gives you a plausible explanation for your absence while you were off doing your super hero thing, should anyone follow you, and any witnesses who noticed something off would be both unreliable and inclined to keep their mouths shut anyway. Of course, the major drawback is that your alibi for not being a superhero is that you were strung out on illegal drugs, or sexing up your hooker at the time... but nothing's perfect. [Answer] # Underwater! [](https://i.stack.imgur.com/BIzmV.jpg) There's a lot of water on Earth (326 million trillion gallons of it). There's enough that we can lose [entire airplanes full of people](https://aviation.stackexchange.com/search?q=mh370) in them for *years*! Just **make your superhero live near a beach**, and when it's time to superhero, go for a swim in the ocean. Once you get underwater, transform. You won't drown (because you're invincible) and you can come back up to the surface thousands of miles away (nobody said you could only fly through *air*). Changing back is just as easy. Once you've waved goodbye to the adoring crowds, dive underwater to your "submersible base" off the coast of Portugal, surface again in mundane form on a beach in Australia. The only downside is if someone steals your beach towel while you're superheroing. [Answer] # In crowded, public place. As others said, cameras screw you. Moreover, obvious choices like "going somewhere" also leave you vulnerable. You could argue you should abandon your phone, since you can be tracked by metadata, but let's not be that paranoid. Anyway, you just don't want yourself to be tied to the superhero appearance. What should you do? In crowded places, people don't mind you. You are a superhero, so they will know you have superpowers. Simply wear something on your face that will make you unrecognizable(e.g. anti-pollution mask, these are getting popular now). People won't know who you are, and you will be able to transform everywhere. [](https://i.stack.imgur.com/94nhq.jpg) Bonus: When people see that some guy in mask transforms into the superhero, you will get followers. Thousands of people will wear those masks to be as cool as you, and this will lead to you being literally the same as others, but with your face covered. [Answer] * You are not going to use any electronic devices capable of communication (at least not as a hero and not immediately before you transform). This alone can make you suspicious, depending on the surveillance laws in your country (not yet, I think, but it's a somewhat realistic scenario for in 20 years if current trends continue). * If there is any chance you might be spotted leaving your transforming spot in hero form, you can't use it again. Ever. * You'll need a plausible explanation for what your normal ego is doing while you are heroing. * This is way easier if you are rich, you can buy a huge manor. You'll need to go the real paranoid fortress route: + Lots of surveillance technology in a perimeter around it + Private security guards (tempted to call it private army) which you make sure will also defend the property against legal intrusions (at least while you are heroing and should be at home but aren't actually) + Locking systems all around and also spread inside the house to make intrusions slow even if your guards fail you. + All rooms in the house insulated against communication attempts (sound, radio waves, light, etc.) with extra good protection for the outer walls. + Absolutely ban electronic devices capable of sensing anything from your house, but for a few rooms which are considered insecure and dedicated to a purpose - say a TV-Room, where you have your home cinema / multi media center, a work room with computers and Internet (for your normal persona), a work room with computers and *no* Internet (for you hero persona) and so on. No smart light bulbs for you! + Get security advisors to find additional strict rules you'll need to follow. + Have all your supplies flown in onto your own helipad/airport using your own aircraft, make sure to include lots of petty orders and don't shop locally, make sure to let your family help. :) Include hidden cabins (or just a locked VIP cabin for your exclusive use which no one else can open to check whether you are inside), anytime you want to leave you just smuggle yourself onto one of your aircraft. Ideally, have them designed so there is a way to leave it while airborne without being seen by the crew/cameras. + Of course have a couple of classic escape tunnels, but I would only use those for emergencies, because evidence of a tunnel is hard to hide if you are ever caught leaving through one. * Either that or go for the other extreme: If you are poor or just minimalistic, then it's also easier: + Go live as a nomad in low tech environments (developing countries, or just far away from city centres) + while living very low tech yourself. + Always do your heroing far away and try not to show off your maximum speed so people underestimate how far you can fly. A vertical start up to like 5km height in dark clothes at night at maximum survivable acceleration should be pretty much unnoticeable (maybe get anti-radar clothes/armor made. If a whole fighter jet can get its radar signature down to that of an uncamouflaged tennis ball, much more should be possible for something as small as a human). * But as an average human in Western European or American society, I don't think it's plausibly possible. Not if your own nation state is trying to find you. On the other hand, if you could coerce police into actively covering up for you: + Police CCTV would stop being a problem + Police could confiscate and muddy evidence. They would need to be careful so as not seem suspect themselves, but as soon as there is reasonable suspicion a vigilante (i.e. criminal) was seen, they should be able to openly intervene and carefully deny as much as possible. + If someone denunciates you but has no hard evidence (recognizes hero coming out of a public toilet, saw you transform in an alley, etc.), police could claim that CCTV proofs otherwise. They could interrogate the denunciant and undermine their credibility (even with fake alcohol tests). + Cell phone tracking would stop being a problem as long as you are careful with apps (easy way: don't install any) and stay well within the jurisdiction of your corrupt police force. + You would still need to be careful, but using most of the urban-centered suggestions in the other answers would suddenly be viable. [Answer] # From his company's tower **Step 1 - Funding** *Since the original question did not specify Stack Guy's flying speed, I'm assuming it is in the realm of Superman's speed; a.k.a. pretty damn quick.* The first thing Stack Guy needs to do is fly to the asteroid belt. Find some asteroids with high concentrations of iron, nickel, gold, silver, etc. Bring them back and sell them for a couple of billions dollars ([if not more](http://sitn.hms.harvard.edu/flash/2016/precious-metals-peril-can-asteroid-mining-save-us/)). Now he has initially solved the "I'm not rich" limitation of the initial question. **Step 2 - Headquaters** Stack Guy sets up own company, Stack Guy Industries (SGI). He picks the city and neighborhood he wants to most directly influence. He buys the right parcel of land. And then he builds the Stack Guy Industries Tower (SGIT). The SGIT is a sixteen story commercial and residential complex. (Sixteen is used for an example, the actual number of floors and their composition may vary based on Stack Guy's funds, needs, and expectations.) The first floor is a full sized grocery store (Cub or whatever other large chain he can get). They get to use the space rent free, in return for keeping their prices low. Floors two through five are SGI's office space. A cube farm, conference rooms, and other manager and executive offices. Floors six through ten are research space. Some more conference rooms and offices for the scientists, but mostly various laboratories. Floors eleven through fifteen are apartments. SGI employees are offered living quarters as part of their incentive plan, for two basic reasons (outlined below). Floor sixteen is Stack Guy's penthouse suite, office, and primary executive conference room. And SGIT has a secret. All of the apartments on the fourteenth and fifteenth floors have a secret door, leading to a hidden staircase, which connects to the hallway between Stack Guy's suite and the executive conference room. Stack Guy told the designers and builders it was so his main advisors would have access to the top floor in the event of a power loss or hostage situation. He also implied it was because it wouldn't be a proper hero hideout without a secret passage. He further implied that he might want his cute CTO to have private access to his room (and verse vica). **Step 3 - Human Resources** Hire SGI personnel. Crisis Monitors take phone calls, listen to police band radios, watch news, and monitor the internet and Twitter. Stack Guy doesn't have super senses, so he needs some way to figure out where crises are happening. SGI, and Stack Guy himself also needs a team of Lawyers. Someone is going to sue Stack Guy, and he also needs someone to negotiate contracts for TV appearances, merchandising, and non-crisis assistance (i.e. Stack Guy can hire himself out as a rocket replacement; he can carry modules to the ISS faster, safer, and cheaper than a traditional launch. Only saving the world is pro bono). SGI also has a team of scientists. They have two jobs. The first is traditional research, SGI tries to make the world a better place by more than just sending out a flying brick to punch things. At the same time, Stack Guy might need a scientist advisor on a specific emergency; how does he stop an erupting volcano, or melting nuclear plant? Because of that, the scientists are more strongly encouraged to live in SGIT, so they are on hand 24/7. Beyond that SGI will need IT, maintenance workers, publicists, HR, and division managers. **Step 4 - Bring it all together** Stack Guy only ever appears from SGIT. Usually flying off the private deck on the top floor, but sometimes through the front doors for various reasons. Meanwhile George T (Stack Guy's original/secret identity) is hired on by SGI in whatever mid to high ranking job best fits his skill set and work history. Whatever position it is, it comes with a fourteenth floor apartment. So now George can sneak back and forth between his apartment and Stack Guy's suite. And he (and dozens of other people) have a plausible reason to live in the same building Stack Guy always appears from. [Answer] ## War zones I get the comic book lore of patrolling Gotham City or Metropolis for purse snatchers. But the fact is, you'll have so much work in Aleppo you'll never get out of the city limits, and it's real easy to hide in a war zone. Unexplained phenomena are easily lost in the fog of war. And if you ever did have any spare time, there are those two small projects in Fukushima and Chornobyl that need a super person just to get cameras into hard places. Who knows, might even pick up a few more superpowers. You're gonna be booked solid. ## The Illuminati "Listen, gumshoe. You've done pretty well to get this far, but you're not the first and you're way, way above your pay grade. Do you really think it's half as simple as we make it look? Sigh... Put it this way, do you really think a fellow like me could operate without sanction from the highest... possible... levels?" You want to be buddying up with the Illuminati or other supranational entity, because they care about the shape of the world, not about dissecting and militarizing you. Find them. And if the Illuminati doesn't exist... form it. [Answer] Use your abilities. You've said that you can fly - this is a significant '[Force Multiplier](https://en.wikipedia.org/wiki/Force_multiplication "Force Multiplier")' as you can be where you need to be very swiftly; so why 'patrol the streets at' all? Your best bet would be to use technology to help - and you've provided that technology in the form of CCTV. Exactly how you use the CCTV is going to depend on a few factors, but the options would seem to be: 1. Have a sidekick who is a computer whizz. They hack the CCTV, monitor the feeds and direct you to where you need to be. 2. DIY it - if you're able to hack the feed, then you don't need the sidekick (although that means a greater workload for you) 3. Make a friend amongst the CCTV operators. If something goes down, then they contact you 4. Create your own net, placing webcams in likely trouble spots Once you're doing that, you no longer need to 'patrol' and can find an ideal point for your base - a nice abandoned lot, somewhere fairly central. No need to worry about transforming, etc - you take your time going in to make sure no one sees at the start of your 'shift'. You can put your 'command centre' (if using option 1 or 2) there, and simply fly out when you need to. You're much more likely to spot a crime happening that way, as you have several sets of 'eyes' instead of just one. [Answer] Jump in a manhole and transform in the sewer. I don't think there's any cameras, they'd have to be infrared if they are. If you're dressed up as a worker, maybe even arriving in a truck, this might provide an alibi for a while. Of course only until someone notices this superhero appearing out of the sewer every time, and then they figure out you are the one going down all along. Once transformed, you may be able to fly to the end of those channels, and fly back to where you need to be. This way there's some disconnect between where the hero came from and where the normal person left. [](https://i.stack.imgur.com/5mA1v.jpg) [Answer] I would say the transform part is not so much of a problem ## Habit is your enemy The true problem will be every time you change in some place you will have to leave it! And maybe J. Doe is unnoticed when you enter a place but StackExchangeMan will obviously be. Even if you change at night in a large desert area you will have to change back at some point and the question remain the same, as you will be tracked by your foes/government/supervillain... May you fly really, really fast. Not sure it help, maybe it's even worst as you will be easily tracked by sound or some kind of thermic satellite detection (friction is your nemesis) Whatever,at some point someone will notice the you're not their every time StackExchangeMan save the world. If you got a family and don't want them too know i can't figure anyway to leave without bieng noticed. Maybe lie on your job and pretend you work by night as security agent or something like that? I would says the three solution for you are: 1. Never change back, no problem, you don't care you'are so strong noone can hurt you. Of course it as some drawback concerning your personnal life 2. Live alone, as an asocial and unloved people in some desert place. Noone will have interest in you, you can leave when you want to go save some innocent. Obvious downside is your real live is not really funny. 3. Teleport!!! If teleportation is inside your powers it solve a lot of problem. You appear from nowhere and come back to no where. Impossible to track you, you can change in your own bathroom if you want ^^ [Answer] My vote: Home. It's just "home" is in a large wooded area in a place with huge amounts of fog. Travel only at night. Make yourself an anti-radar suit. Transform, fly up to your fortress (SEM's "home" in orbit) and leave the stealth suit there. Keep your airspeed down, your takeoff is pure vertical. By the time you're clear of the fog you'll be high enough that you won't be eyeballed from the ground and you monitor the air traffic to stay away from planes. (You need to do this anyway, you don't want a midair!) Lift vertically to the height of your station, then accelerate. Nothing will show this flight. Make your normal flights to/from your fortress very obvious--NASA-style returns and when going up make your gravity turn low--boost to orbital velocity while still high in the stratosphere. Both ways you leave a fiery trail in the sky, make it look like you can only do minimal maneuvers out of atmosphere. [Answer] Place where it is considered wrong to say that you were there, or to record who goes there. So I am thinking ## [AA meetings](https://en.wikipedia.org/wiki/Alcoholics_Anonymous#Meetings) or another kind of X-Anonymous meeting. While the attendance AA meetings are not legally privileged information (in most places). No one who attends should be willing to tell you were there. And they by design as supposed to be in places where you going in and out is not a matter of public record. Similar for any kind of community drug rehab clinic. Domestic Violence centers probably also. In the right places, church's would work as well. So you go to the meeting hall. Maybe attend the meeting, maybe not. Go to the toilet, and then skip out. In a large city, you can probably find one, any night of the week. [Answer] Ok here's a pretty cool answer I think: Study geology\* and use your super human skills to **create an elaborate underground labyrinth**! The labyrinth could have multiple access points to the outside world and could have connections to multiple indoor-type places (some shed in Nebraska, a mountain hut in Switzerland, some place near your own home). A combination of the difficulty of your labyrinth, together with the use of a lot of entry/exit points should make it very difficult to pinpoint the origin of your location. Perhaps you will need to restructure the labyrinth from time to time to make sure no one ever maps it completely (be sure to remove any children or spies before you do). One obvious problem with this is the fact that you will need to get to an entry point before you can transform, which might take some time depending on where your location is relative to the entry point. \* Not sure if you really need to study geology or something else, but you want to make sure you don't accidentally start collapsing buildings or other structures by digging tunnels. ]

[Question] [ In the nation of Xenqu, a hereditary monarchy has ruled for centuries. The Xenquan society is in a medieval period, although the recent invention of paper and the increasing use of gunpowder may signal the start of a period of relative industrialization. One day, everyone aged 25 years or more drops dead. The frightened remnants of society see that the dead show no signs of any injuries. Magic? Perhaps. That is the only conclusion they can make. Over the next few months, people suddenly keel over the instant they turn 25 years old. It quickly becomes apparent what the cut-off age is. People are anxious to find a way to combat this plague, whatever it may be. In the meantime, some form of government is needed. The problem is, most people are relatively uneducated, given that the average age has now plummeted to somewhere in the mid-teens, and will slowly rise as the birth rate inevitably drops. The son of the monarch at the time of the collapse was 22 years old, and so he now regains the throne. But there are no other members of the royal family left, and he has only three years to live. What form of government will the people choose? It seems incredibly difficult for the uneducated population to make critical decisions in a democracy, and yet any monarch old enough to properly rule will die before any lasting policies can be implemented. Other forms of government suffer from the same flaws. Additionally, should the government be on a national level, or would splitting up the kingdom into independent states (think of nations the size of states in the Holy Roman Empire) and allowing local government power be a more effective choice? Here are the factors I'd like to focus on: * The ability for the government to remain stable, given that politicians won't be in office for long. * As a corollary to that, there's the problem that any politicians won't necessarily be able to achieve any long-term mandates. * Low education levels mean that most people won't be educated enough to make proper decisions. --- Note: The plague only affects Xenquans, and nobody else. [Answer] I never thought to say this but the answer is socialism. Better yet, a socialism that has the potential to actually work. Here are the points for my reasoning. * True socialism has never been successfully implemented on a nation-state scale, most times it takes the form of Communism, which has often failed because you end up with a 'dictator for life' and the we know how well that ends up. In this system it is no longer that big a deal if someone rules for life as ruling for life would last at best 5 - 8 years. * Additionally you usually end up with what is in essence an hereditary monarchy as power is passed from family member to family member, not really an issue in this case either. Maintaining a hereditary dictatorship for long periods of time will be tough with short reproductive cycles. * Child care will necessarily become communal as parents won't live long enough to raise children to adulthood (given they are human) * Learning will be on the job, even from an early age, you don't have time to sit in a classroom until you are 18. * Technology will regress somewhat and stay repressed indefinitely. First, you will lose a ton of knowledge in your elder cull. Additionally even if you catch back up to where you were pre-mass death, specialization takes time, time people won't have, so there will eventually be a cap on how far we can technologically progress * Governments will be mainly local and there will be a slight reversal of people moving to the cities. * Communal farms with communal child care and team work would be a plausible norm --- Or I suppose anarchy is the other option... [Answer] You ask what government the people would choose, as if they have any say in it. Unless your centuries-old hereditary monarchy is more of a figurehead (think modern UK) than actual *rulers*, the idea of the people *choosing* their government is foreign and unlikely to gain traction on its own. The masses will, by and large, expect the monarchy to keep producing monarchs. The lack of an heir could cause unrest; historically (I'm thinking western Europe here), that's the sort of thing that a rival faction would take advantage of to put *its* candidate on the throne. A smart monarch, therefore, will make sure there is an heir waiting. With the new reality -- at best your heir would be a very young child -- I would expect the monarch to broaden the pool -- in the absence of a son the crown might pass to a younger brother. We might see the crown bounce back and forth among branches of the same family -- it passes to the king's brother and then to the previous king's son (who's just now coming of age) and then to the brother's son and so on, zigzagging down the family tree. The medieval Rus used something close to this, called the [Rota system](https://en.wikipedia.org/wiki/Rota_system) (thanks to PyRulez for this information). In your world of short lifespans it becomes a priority for all in the royal line to "queue up" a son as soon as they're able, but knowing that the son will be your successor's successor rather than your own. Clever monarchs will be able to sell this to the masses as natural, so they don't get any ideas that the monarchy is in trouble. One consequence of this is that it will become the responsibility of everyone in the same generation of this family to teach and train the next generation. A king won't be training his son to take over; he'll be training his nephew, and should expect his brother (as the child's father) to be heavily involved. The other siblings in the family will have more influence than they might have with a traditional patrilineal monarchy. We should expect to see more jockeying for position in generations with more than two brothers. A system without a single, unambiguous line of succession is less stable, so the royal family will need to find a way to contend with the competition for position. That any one person's time on the throne will be short, and that he might care about consequences for his descendants, could help mitigate. [Answer] Does the change effect ethnic Xenquans, or anybody within Xenqu? Either way, Xenqu for Xenquans is soon to be a distant memory. If the plague affects anyone within the borders, there would be a mass exodus to neighboring lands; Xenqu becomes a ghost-kingdom. If the plague affects Xenquans wherever they are, but foreigners are immune, the kingdom will be conquered forthwith; Xenquans are rapidly outcompeted evolutionarily and die out. The form of government any temporarily-surviving Xenquans live under is therefore whatever exists in neighboring lands. [Answer] Simple: Anarchy Contrary to popular belief, [anarchy](https://en.wikipedia.org/wiki/Anarchy) is not just about the absence of government. Anarchy is about distrust of authority. Since no one in this situation can be trusted to make good decisions for the community as a whole, anarchy seems to be a natural next step. I imagine a community would self-organize into [voluntary associations](https://en.wikipedia.org/wiki/Voluntary_association). As they need help from others, individuals would enter into mutual agreements. These would largely be temporary affairs, lasting only as long as the organizing individuals have need of each other. The VA would also be fluid, adding and losing members as age or need dictated. Eventually, there would probably be some arbitration guild created to manage these agreements, to ensure they're fair to everyone and allow individuals to move into and out of the agreement with a minimum of fuss. This arbitration guild wouldn't have any real authority, and so wouldn't be viewed as "The State." Over time, the arbitration guilds in different communities (e.g., Cincinnati, London, Children of the Nile Delta) might acquire more power and/or authority as communities reach out to each other. These inter-community connections would still belong to the VA structure, with arbitration conducted at each end by the respective arbitration guilds. [Answer] you assume there must be a government. 25 years isn't that long from birth to death to consolidate power. Especially when people don't hit puberty until 10-13. Half of their life will be over before they become 'adults'. Many males will still be growing only a couple years before they die. It takes time for wisdom to accumulate in our species and without someone older and wiser passing on their wisdom, it takes even longer. I suspect most 'government' would be small areas ruled like street gangs. Added after learning that the plague is localized to the one race. The country will be taken over and managed by a neighboring country, likely enslaving the population for their own use. [Answer] In a monarchy, especially a pre-Enlightenment monarchy, people get used to following orders. for the vast majority of the nation, this would not change; if all your adults die, you're going to look to the crown for help; or, if you don't, you'll probably dissolve whatever emergency regime you'd formed whenever the king/queen finally does send someone to sort things out. As long as the new king takes charge of the situation, everything should stay pretty much the same, at least for the first few years. Farmers will still farm, lords will still lord, and merchants will still, er, merchandize? The problem you run into is in succession. Immediately after this catastrophe, apprentices and/or heirs should be plentiful enough to take over all major professions, but with their ends impending there will be plenty of opportunity for very young people to be placed in positions of power. The first problem with this is quality; you just can't teach someone how to be a master craftsman in a few years. Technology levels are probably going to slowly slide backwards as new products fail to match the quality of old ones. The second problem is that despite everyone's general lack of talent, people are going to *think* they're good at things. Just imagine a fifteen-year-old who's put in charge of carpentry for an entire village; this kid grew up in a society where the position he now holds was usually held by someone of twice or even three times his age. And he's still the best person for the job. As a result of this, I think any government would lose all stability. Promotions are going to come around a lot faster than before, so people are going to get used to upward mobility. When that mobility caps, they'll look around, see a bunch of kids with no more experience than them, and think to themselves 'if I'm so good at things, why aren't *I* the king?' From here, it's hard to say what would happen. All I can say is that the government would be unstable. People under the age of 25 don't really care about a future they're not alive to experience; this may change a bit once Death draws his line in the sands of time, but I'd be willing to bet a lot of it is instinctual, rather than cultural. People will be far more willing to make changes, even if those changes include coups, assassinations, and general anarchy. It's possible that things will even out after a while, and there will be some sort of stable government. But I don't think it would be any different than how governments formed in ancient times; someone just gets a lot of power, and finds a good way to pass it on to a successor. I don't think democracies would form; they tend to be difficult to establish, and ancient people didn't really seem to even consider the idea. [Answer] If they don't just panic and revert to anarchy, I think they would go to a simplified form of their monarchy, **without** the customary checks and balances. A 50-year-old duke would be a good counterweight to a newly crowned 22-year-old king. A 25-year-old duke might be unwilling or unable to offer wise counsel. But if the monarchy is well organized, the 22-year-old prince would be prepared to step up to the crown. The king would be what? 40? 50? In a medieval society, the king could drop dead at any time. The prince would have had advisors, but not a *regent*. A bigger problem could come in guilds or religions, where the "designated successor" to the old boss is almost as old. Juniors would not be trained to step in. That would result in a situation where those juniors act according to a simplified understanding of their rights and duties. Say a journeyman-turned-guildmaster appeals directly to the justice of the king, not knowing that you don't do that unless the nobles and notables of the region have looked at the problem. [Answer] Given that this is a medieval society, it will collapse. The first thing that will happen is mass starvation. Assuming infant mortality ceases to be important after about age 5, and adults are productive from 15 to 45 with an "old age" with mortality constant from 45 to 65, the proportion of "non-productive" (old and young) people is about 45% (15 years childhood, 30 years adult, average 10 years old), the elimination of everyone over 25 will allow only about 2/3 of the children to survive. The suggestion that children will be put to work at a younger age simply does not wash. In medieval societies that *already* was the case. Medieval societies simply did not educate most children, and illiteracy was overwhelmingly the norm. The 22 year-old monarch will be left trying to control a collection of nominally subordinate entities which in fact are going to realize that they don't need to be subordinate. Medieval kings did not have large armies - they called on their barons to provide men when needed. Fealty from the barons dies with the barons, and their sons have not sworn allegiance to the king. That would happen when the old baron dies and the son inherits. So the new king has no power base he can depend on. The death of the olders will essentially destroy the entire governmental structure, as ruling nobles were generally older. There will be young heirs waiting to succeed, but the power vacuum will encourage the new leaders to try to conquer their neighbors. The social chaos resulting from adolescents and young adult males acting on their hormonal aggression levels will result in major reductions in agricultural output at exactly the moment when everyone needs to be working as hard as they can to produce food. Most likely, the result will be a reversion to tribalism, and a new Dark Age will sweep the land. [Answer] The society will quickly change. The education system would be severely abreviated and simplified. Otherwise, it would be too spoilery if people can only get a university degree when they hit 23 years old or so. Further, there would be no teachers in the university alive for a time long enough for that. The basic education would probably end when people reach their 10 or 12 years old of age. People would likely try some speciliaty/university courses that should be completed quickly, when people have no more than 20. Teachers should teach until they die. People should work until they die. There is no such thing as retirement. Teens should engage in sex and have children as soon as possible, if possible when they are between 12 to 15 years old. The reason is that people who have kids in their twenties will have no time to educate their children and see they grow up. Also, each couple should be able to raise several kids and be able to at least start the education of the youngest one, so the first baby should come very early. Kids should start dating when they are still in their infancy, possibly when aged between 7 to 10 and should avoid breaking up or divorcing at all costs. If some couple breaks up or divorce, they should be incentived to get new partners as soon as possible if they still didn't reach their twenties. Since people would and should engage sex in their teen years and the life is too short to suffer major consequences from that, open/poly relationships and sex parties will be much more common. People would start taking serious jobs still in their infancy. Six or seven year old kids should get the simplest jobs that don't need brute force or complex thinking. Most people start in their life jobs when they are 14 or 15. Bosses, CEOs and people involved in strategic jobs should be able to reach their positions when they are between 17 to 20 and eagerly teach as much as possible to their children/successors that will take their positions when they die by turning 25. The society and everyday life would be severely damaged and will recede significantly since people are much less able to accumulate sophisticated knowledge and there are much less reasons to do so. Knowledge will also be much more scattered and more people would be needed to do a single job that in our elderly society someone in their forties could do lonely with enough experience. This also mean that people should be much more team workers - Many teams of trainees and juniors. Also, the life is short, so people would likely try to live it the best possible. People would really hate time-consuming things. Carpe diem! Since dangerous behaviours that could make you get problems in the future are much less a concern, teens would likely drink alchool, use drugs, smoke, engage in (possibly unsafe) sex, engage in violent behavior and enjoy parties much more than in our common eldery society. Most of the top government positions would be filled by people which starts when they are somewhere between 15 to 18 years old. Those people received special education for their jobs, likely being tought directly by their predecessors with the explicit purpose of replacing them someday. This would likely create an aristocratic society - only people who received special education for being able to fill government positions are eligible to fill these positions. Further, people who are deemed incompetent, unfit, untrustful or too old by the rulers are excluded from the possibility of succeeding them. However, the population would still be likely to be able to vote in the people who were not excluded from the sucession line. Further, since there are no people with much experience or with enough time to create a power network, it is likely that the population would be able to vote for many important things. Also, it is likely that people will be able to vote when they turn 10 or 11. Also, if people knows exactly the day that they will die, people who are near enough (i.e. 23 and 24 years old people) would likely go crazy. Many 24's will likely engage in criminal activity, risk their lifes doing irresponsibly dangerous activities, do crazy things or simply going nuts. Many of those people would go nuts trying to do as many things as possible in the least time as possible when they still are living. Many people in their twenties would likely get severe obsessive-compulsive psychological disorders that only get worser and worser everyday. [Answer] First, to fully consider your question, consider this: Imagine a world where humans live to be 300 years old. What would that world be like? And then imagine life was suddenly "shortened" to a mere 75 years? I'm sure, if asked, the people of that world would imagine that the relative "youth" and "inexperience" of the population would certainly lead to demise, moral decay, tribal governments, etc. as the problems of passing on knowledge with such little time would make it nearly impossible to retain a structured government, etc. In your example, yes children would start bearing children much earlier - as they hit puberty perhaps (maybe 11 or 12?). That gives them nearly enough time to raise their children to puberty before they die. This is not much different from prehistoric times when humans had a life expectancy of maybe 30... although the maximum life span is known and can be planned for; a significant advantage. Does this mean pre-historic government? Unlikely. Many young people are strong leaders, capable of strong leadership and can recognize the benefits of existing political structures - even capable of creating newer, better ones. Some of the policies might change (like a 4 year presidency?? And the possibility for 2?). Since you make the assumption that the monarch has a son of 22, this gives that monarch just over 10% of his life to figure things out. That's relatively short, but would allow for a child monarch to be born and granted authority. And historically, child monarchs can be successful, so there is only the transitional instability that would threaten the monarchy. That would depend on many factors like the character of that son, the counsel available to him, the human support systems that remained in place after the initial wave of death, a lot of luck, etc. But essentially, technology and humans would simply adapt to a shorter lifespan, just as we have adapted to a much longer life span since pre-historic times. EDIT: I also would like to add that our educational system now teaches concepts like relativity to high school students. At one time, scientists and the general population believed that such ideas were so far beyond the comprehension of "average" people that only a handful of people would ever know about it. This type of assumption is repeated throughout history - and debunked repeatedly. There is no reason to believe that technology, learning and other tools of society advancement would be unsustainable with a 25 year life span. It does get progressively more difficult as lifespan shortens, but at 25 most people still have about 25% or more of their life as "adults." Reduce life expectancy to 10% or less and then the dynamics might be vastly different, as growth hormones and changing bodies create a lot of instability in logic, planning and decision making. However, it is also unlikely that the population could regenerate since the window for reproduction is so small that maintaining the population would, at best, lead to a very strange and unpredictable society. [Answer] Since three is an inherently unstable number, a tetrarchy would form. The four rulers would be chosen from the four most prominent families. Each would reign for five years, from their 18th through their 22nd year, with a two-year co-regency to train the next leader, followed by one year to transfer general skills to their own family and get their affairs in order. This time period of two decades per full rotation is enough time to get married at age 15, sire an heir, and have that heir raised to the age of accession in time for the next rotation. The preceding family would be responsible for parenting the succeeding family's children, thus cementing the bond among the four families. All industry will revert to apprenticeships and guilds. Natural geniuses and the physically strong and courageous will fill most of the most important posts, because moderate-speed learners will never get to their full potential. Since young, unmarried people commit most crime in any society, controlling violence and protecting property will be major concerns. Paul [Answer] What is the population density of Xenqu? If the population density is low, it will likely disintegrate into small tribes or family groups. Evolutionarily, one of the biggest difference between humans and other primates is our longer lifespan, which allows passing knowledge from one generation to the next, and build larger stable social structures. If you cut the lifespan down to the life span of a Chimpanzee, there is a good chance that the social structures will also soon develop towards Chimpanzee society - which means, smaller social units, and heavier reliance on violence instead of laws. You may also see more emigration and innovation. It has been said that when early humans first left Africa and spread all over the world, it was teenagers who led the way - people just finding their place in the world, and often that was a NEW place that hadn't been settled yet. Teenagers also don't always understand why things are a certain way, and as a result may try out and invent new things that adults haven't thought of. In a "normal" human society, the adventurism of teenagers is counterbalanced by the stability from their parent's and grandparent's generation. In a way, this would be a Pippi Longstocking kind of world. [Answer] Hmm, I don't see why such a scenario would inevitably lead to a dramatic change in forms of government. Yes, hereditary monarchy as practiced for most of history might become impractical, as the monarch's children would likely all be too young to rule when the monarch dies. But all other forms of government would be just as viable as they are today. Democracy would certainly still work. Sure, the candidates would all be under 25, but you could still have elections. I suppose terms of office might get shorter. Like presently a U.S. Senator serves for 6 years, which means anyone older than 19 when he's elected would never live to serve out his term. Aristocracy and one-party rule would still work. In such systems, basically the ruling class pick the people to be the next generation ruling class. No reason why they couldn't still do that. They'd be less able to pick their own children, but actually as a class rather than an individual this is less of an issue. Maybe your kids can't take over your job the day you die, but they can hang around and take over somebody else's job when he dies in 5 or 10 years. I'd expect the operations of government would change, as office holders would be less experienced and know they have less time. Bad ideas would probably be more likely to be made law because the rulers wouldn't have the experience to know that it didn't work the last six times it was tried. They MIGHT study history of course, but many wouldn't. And knowing that you only have a few years might well lead people to be more in a hurry. I can't wait until the next election to get this policy enacted because I'll be dead by then! We can't spend years debating this policy because we don't have that much time. So policies get rushed through. Sometimes that would be good: instead of debating endlessly let's do something! But often it would mean that policies get enacted with inadequate consideration and planning. BTW hereditary monarchy could be made to work if you adjusted the system. Say that your younger brother inherits the crown instead of your son, or your cousin, whatever. Of course such a world would face all sorts of problems having little to do with government per se. Education would have to be shortened: you couldn't afford to wait until 21 or 22 to graduate college if you're only going to live to 25. Hard to imagine someone being able to start a career before 15 or so, maybe 12 or 13 at the earliest, so half your life is over before you start contributing to the economy. And all the workers have much less experience, so productivity must be lower. If the species is going to survive, people would have to marry very young. And even if you have your first child at 15, you're going to be dead by the time he's 10. If you have a child at 20 you'll be dead when he's 5. So who's going to raise the children? You might say that life expectancies have been shorter in the past and people have managed. But life expectancy of the upper class hasn't changed much. I recall seeing a study once that found that the life expectancy of a U.S. senator has not changed since the founding of the U.S. (I presume because the upper classes have always had access to decent food and shelter, some semblance of medical care, etc.) So there have always been some number of older, more experienced and mature people to keep things organized. In this society, there wouldn't be any such person. [Answer] I guess the first step would be to select a group of promising 15 years old kids and give them the best political education still available (most teachers and preceptors having probably been over 25) so in 3 years when the new King die they could assure a collective government for the next 5/6 years. At the society level, some adjustments will have to be made too. As raised in previous answers, socialism will be the only viable solution as you cannot really let uneducated kids take society changing decisions, or even expect them to make the right choices to ensure their own survival. Also the traditional family unit would no longer function. Raising of kids would have to be assured by government facilities where 12-25 years old would take care of 0-12 kids. We can assume all kids can have a basic education up to 10-12 yo (when they are old enough to work in farms); then a selection should be made to find those who could get 4-5 years extra education and take strategic jobs (teaching/ruling/medical), while others will start working to feed the kingdom. That would let the educated class about 5/6 years of adult life, which should be enough for assuring stability in a government (most countries have 4 or 5 years terms for political functions). Of course, things like scientific research or medicine would lose a lot but this is a medieval society so I guess it won't be such a change), but in the other hand since politicians won't have any chance to be elected for a second term they may actually take sensible decisions. Bottom line: There is no "fix'em all" solution, but damage control can help until a real solution is found. [Answer] I expect that with their economic base wrecked, their military in shambles, and pretty much all expertise in everything gone, they will simply be conquered by one or more of their neighbors, rendering their form of government a moot point. [Answer] We seem to forget that in mediaeval societies, the average age was much younger than it is now, and people moved into adulthood much earlier. Education was finished by 12, after that you were earning your living. 16-year-olds were put in charge of armies. If you were over 50, you were considered old. I don't see any problem in a community of under-25s organising itself effectively. The big change in this world is not that people are dying younger, but that they know the hour of their death. It's difficult to predict how people would react to that. They would probably put a lot more effort into achieving something in the limited time available. And into succession planning. [Answer] ### They *could* have a democracy. That democracy, however, would never be quite as powerful as the democracies of today. The government may not be able to enact controversial laws, but it would still be able to enact and enforce non-controversial laws as laws against, for example, theft or unjustifiable homicide. The government most likely will not be able to maintain any government agency like the US's NSA, CIA, FBI, or DoD, but it would be able to provide some basic law enforcement & military services. That is to say, our police and military might only consist of those who don't have more training than the real-world people, who have only taken a concealed-carry class and earned a white belt in some form of martial arts. If the citizens are lucky, such people will still be able to communicate vital information using computers and/or two-way radios. [Answer] Following on from the line of logic that [Jim](https://worldbuilding.stackexchange.com/a/29236) started, how would the biology of a species that lives 300 years work? Likely children would take longer to develop (think "teenage" years would occur somewhere around the 30-40 year old mark with puberty at about the same time), and again you would hear the same remarks about us from them. So what happens reducing our lives? Girls today are hitting puberty at 8-10 years old and are capable of giving birth - according to [this list](https://en.wikipedia.org/wiki/List_of_youngest_birth_mothers) on Wikipedia the youngest mother recorded was 5 and the lists for 8/9 are noticeably long. Since girls who have children earlier will have much greater success at influencing the population (a girl who starts a 7 or so could reasonably expect to see her grandchildren), so evolutionary pressure would mount for girls who hit puberty early, but also have the emotional maturity to handle a baby. How this affects the boys of this society is a little less clear, but likely similar pressures for "youthful parents" will be present. Ultimately then the government will have the opportunity to be just about anything you want, following an initial period of instability (and possibly some of the stop gap solutions mentioned in other answers). I do agree with other answers that note that, if the ability to learn and retain information does not vastly improve, there will be an ultimate limit on how advanced the society can get without some kind of magical intervention. [Answer] I think you should not rule out that *some* will develop an immunity, leading to a small group of *true* elders that will probably serve as the only ones to gain a degree of wisdom unreachable for the rest, even their "wisest" ones. At first, there will probably be a rule of the bullies. Probably not lord-of-the-flies style but perhaps not far from it. After that, a period of adapting with a kind of socialist system with a tribal chief, a primus inter pares. Then, after it becomes clear that there are certain immune "chosen ones", the question of who rules becomes less important since no important decision is made without consulting the elders thus making them the secret rulers - of course without them wanting to rule, else they wouldn't be wise... That said I could just have one beer too many... [Answer] Several of the answers have neglected the transition problem, focusing on how an society works with a 25 year age limit. That is hard, but it is much harder to imagine what happens in the short term. Total chaos. Every commercial organization of any size has key people older than that. A few will keep going because somebody younger steps up to the challenge, but most will be unable to do so. If you have cities that depend on food being brought in, you may have large scale starvation. Probably cities become unsustainable. The age of adulthood decreases because you need more productive years. Old societies pegged it around 13, which seems reasonable. Now you need commercial enterprises to work with that level of maturity and education. You will lose a lot of technology because people can't learn it. There seems an opportunity to explore what happens when your leaders are not experienced. Rash actions become more frequent. If that happens on both sides, you have another disaster. [Answer] Educate kids about life at a very young age, so that they can grow up to actually know what they are doing and take college off of the list of necessary things for a job. People will certainly have a *"Why bother?"* sort of feeling, though, and that will not be helped by being teenagers nearly half their life. Authority will be dumbed down, not to tribal level, but still not great. Basically, the government will turn to a sort of total democracy, and no kid old enough to write won't be allowed to. Because everybody's gonna *die*. [Answer] It could develop, but it would probably be pretty unstable and there could be a high chance things would fall apart quickly. Before someone calls me an edgy boomer or something, there is a reason why we have had older people in charge of governance instead of younger people: [teens tend to have less empathy than mature adults](https://www.nbcnews.com/id/wbna14738243) and most people are not fully empathetic until they fully develop a [frontal lobe at the age of 25](https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=1&ContentID=3051#:%7E:text=The%20rational%20part%20of%20a,cortex%2C%20the%20brain%27s%20rational%20part.). There is a reason we don't give most people an adult test for Antisocial Personality Disorder until they are 18 to 25: a lot of behaviors that are considered normal for teens and young adults would get an adult consider immature (at best) or a low-functioning sociopath (at worst). Those under 25% are more likely to suffer from mental illness with 9.4% of those under 25 having [Narcissistic Personality Disorder](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2669224/) (a mental illness that requires a lack of empathy to be diagnosed with), up to 9.3% of young adults having [borderline personality disorder](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2676679/) which is a [associated with a lack of empathy](https://psychology.stackexchange.com/questions/27051/are-all-bpd-people-narcissist/27063#27063), and it is proven that being a young adult makes you more likely to have [dangerous mental disorders](https://www.webmd.com/mental-health/news/20040804/personality-disorders-affect-15-of-americans). Teen brains are wired to be [short-sighted](http://www.npr.org/templates/story/story.php?storyId=124119468) and terrible at making long-term decisions & to generally ignore good advice given to them by older individuals, which is why we have teens that are more likely to join extremist groups, hurt people, or do stupid things like go on [Spring Break during a pandemic](https://khn.org/morning-breakout/spring-break-is-coming-but-study-says-teens-more-likely-to-catch-covid/). Lack of education also makes them more likely to believe in conspiracies & suffer from mental disorders like paranoid personality disorder or schizotypal personality disorder. Teens with exceptional emotional intelligence can possibly start some kind of semi-functional society like tribal governments apes like [bonobos are capable of making](https://greatergood.berkeley.edu/article/item/political_primates) or clans or some other kind of smaller-scale government. Technology may advance slower, education will be slower, and people will have a higher chance of doing something that negatively affects society while thinking they are in the right, but they will have a chance. Don't except large-scale cities and metropolitan areas like what we have now though. ]

[Question] [ I'm going camping in two weeks and I really don't want to get bit up by mosquitoes. So I want to figure out a way to commit total genocide of all mosquitoes in at least a 20 mile (32 KM) area around the campsite. I also want the camping trip to be enjoyable, so nukes, doing a total gamma soak, or otherwise irradiating the area is not going to be a good solution. Ideally a budget of around $100K, and while the area should be mosquito free, the solution should not kill the non-bloodsuckers. I'd also prefer not be be tried for war crimes. As to technology level, let's say current to very near future, thought the more current the better. Edit: To close voters [real world questions are on topic](https://worldbuilding.meta.stackexchange.com/questions/6161/a-proposal-to-finalize-the-are-real-world-questions-on-topic-debate). [Answer] **100k would buy you many Mosquito Traps** [Mosquito traps](https://envirobug.com.au/pages/mosquito-traps-faqs?gclid=EAIaIQobChMIgNK3_PjL2wIVRiQrCh0kcw95EAAYAiAAEgJX7fD_BwE) are now readily available. According to one in particular, Envirobug, the following is how it works: > > by using a combination of UV light and the small amount of Co2 gas > produced from the titanium dioxide impregnated collars on the inside > of the traps. The gas is produced through catalytic reaction from the > UV light and heat produced from the lamps. When the trap is running > the centrally mounted fan creates a powerful downdraft that mosquitoes > entering through the upper windows searching for a blood meal are > powerless to resist. Once trapped the constant flow of air around them > in the basket, kills them by dehydration. > [](https://i.stack.imgur.com/zoSdU.png) > > > For a low price of $129 you can get one. This means you can afford 775 mosquito traps. By evenly dispersing them, I'm pretty confident that there would be little, to zero, chance of you as a mosquito resisting going into one and surviving. You can now camp in peace. (However just to let you know, I don't condone slaughter of them... we need to think of ways to coexist with all our fellow lifeforms...) [Answer] ### On a slightly envelop pushing note ... Come to Steve's Ant & Mosquito-Free Resort. Many years ago eccentric wanna-be billionaire Steve decided to built a natural wildlife reserve without pesky mosquitoes. To this end he took 32 km² of prime country (a circular park 6.2 km in diameter). Sealing it in a dome using special air filtration systems and airlocks he wiped out all the mosquitoes and ants in it. Then it was repopulated with carefully selected animals, flora and fauna and insects that don't bother people. Now we are ready to open it to the general public. For a small premium you and your family can enjoy a camping break in our fine resort. How can we afford this? Well, the fee is \$ 100K to help pay our investment costs. But worth it for the family that likes to have camping holidays without hospital stays afterwards - think of the savings! And we have easy terms and you can pay this once in a lifetime trip off as easy monthly installments. ### Bonus No hostile species that might eat baby Jane. We didn't let any of those nasty mountain lions, coyotes, rattlers and bad bears into the park. Our deer is guaranteed to be more Bambi-like than in any other park. [Answer] # You can't go wrong with [FIRE](https://youtu.be/eawL6aJ2nBc) I am not talking about [burning](https://youtu.be/eFTLKWw542g) down the area, no. Simply making a big stack of wood, or many small ones around the campsite and [setting them on fire](https://youtu.be/6l6vqPUM_FE) will mostly suffice. That's what we did in Sweden during midsummer night, anyway. The little suckers really hate the smoke, and it also makes for some [great atmosphere](https://youtu.be/RF0HhrwIwp0) & is also [great fun for the kids](https://youtu.be/wmin5WkOuPw)! Maintaining a bigger [area](https://www.youtube.com/watch?v=It7107ELQvY), you will probably need to hire someone to help you maintain the flames. But baring a heavy rain, that's all in the way of it. If you want to invest against the rainfall as well you might want too look into substances such as [napalm](https://youtu.be/Ri7-vnrJD3k). Sadly (or luckily if you ask a biologist) that solution won't exterminate the bloodsuckers, so there's no permanent danger to the biosphere. [Answer] Genetic engineering terminator genes into the local mosquito population would eliminate the mosquito population since the genes spread far through the population, and then when 2 mosquitoes mate that have the terminator sequence they produce offspring that are sterile, leading to the collapse of the population. +100 for unintended consequences and it spreading worldwide, eliminating virtually ***all*** mosquitoes. [Answer] as of today, in terms of effectiveness, this is the best you can get. Alas, it's still on the prototype stage and it would cost a tad more than $100,00 [Mosquito laser](https://en.wikipedia.org/wiki/Mosquito_laser) Or you could just buy a cheap metal net, electrify it at night and enjoy the sound of the suckers frying themselves. Other than that, unless you use a kiloton of good ol' DDT, you can't wipe out mosquitos in such a wide radius without eradicating the rest of insect life. \*\*EDIT: \*\* This Futurism article goes more into details, including the fact that the real thing is eve harder to realize than previously trumpeted. My apologies for an incorrect link. Administrator, please demote the answer [Update on mosquito photon net](https://futurism.com/the-laser-shooting-mosquito-zapper-were-still-waiting-for/) [Answer] **Weaponized citronella** With a few tweaks, the popular repellent can be made even more potent, giving the little monsters teeny-tiny panic attacks. Deploying in a ring arrangement, with your campsite at the center, using a smoke bomb as a base, the pests can be driven away to a radius of your choosing. [Answer] Simple. Relocate several thousand bats to the area. Also, camp under a walnut tree. Mosquitoes and other insects avoid them. [Answer] # Wipe out mosquito larvae with acoustic larvicide. [Acoustic larvicide](https://www.ncbi.nlm.nih.gov/pubmed/28206869) is a relatively young technology with controllable results. If you blast sound waves somewhere between 18 kHz and 30 kHz in water where larvae are growing, it will rupture their air bladders and either kill them immediately or otherwise prevent them from fully maturing. Depending on the duration and intensity of your acoustic death ray, you can control approximately what percent of the population is killed. These devices seem to be available for sale currently. A handheld device can be purchased for about [\$7000](http://www.norwichbulletin.com/x329769466/New-device-kills-mosquito-larva-with-sound) (probably less now, that article is from 2012). A larger one may cost a bit more, but probably still well within your $100k budget. Hire a couple of fellow mosquito-haters to use it on all the standing water in the area once a week for a couple months before you go camping and there should be none left to bite you. **Pros:** * Technology is currently available * Has minimal effect on other wildlife (except for food chain considerations) * Within budget * No more mosquitoes **Cons:** * No immediate effects on biting population. You must prepare beforehand. * You may need to bring in some other [pollinators](http://www.mosquitoreviews.com/mosquitoes-niche-pollinate.html) to keep the local flowering plants happy * You may need to find new prey for the [predators](https://www.orkin.com/other/mosquitoes/mosquito-predators/) that depend on them for food [Answer] Mosquito predators. Something already exists called "fly predators", which are a parasitic wasp which kill fly larva, but which are themselves invisibly tiny and harmless. Breed them in a lab and spread them in such a concentration that they kill all the mosquitoes before starving to death. To prevent unforeseen ecological problems, make it so they can't breed outside of the lab (maybe make them all female, just don't use any frog DNA!). [Answer] # Alcohol: the cause of and solution to all of life's problems * Step 1: Hire as many bums and/or college students as possible. * Step 2: Buy as much extremely cheap booze as possible. * Step 3: Put the booze into the bums/college students. * Step 4: Strategically position the bums/college students throughout the desired area. * Step 5: Wait for the mosquitoes to strike. Flies and bees can alcohol poison themselves to death eating rotting fruit. Hopefully this also works for mosquitoes. * Step 6: Enjoy not having mosquitoes. On the minus side, the mosquitoes will come back eventually. On the plus side, you'll be too drunk to care! [Answer] For $100k you can have your very own mosquito chopstick bot and a years supply of tadpoles. Your mosquito chopstick bot will diligently pluck mosquito's from the air all day and night long until the job is done. Your tadpoles need only be slipped into any standing water, they delight in slurping mosquitos larvae down from the surface. Hmm yummy. Bye, bye mosquitos. [Answer] The most migratory of mosquitoes only travel a maximum of 7 miles (11.26 kilometres) from their birth point as larvae (wrigglers). Therefore you could treat every water source within that range of the borders of your protected area where larvae can spawn with a solution. Possible solutions include Bti (Bacillus thuringiensis), methoprene, or oil and also the introduction of natural predators in large numbers. Guppies (small fish) or Gambusia (a mosquito hunting specialist guppy species that are already used in this way) would be an excellent candidate as they can be introduced and breed rapidly. The introduction of small birds such as purple martins, swallows and waterfowl would prey on the adult mosquitoes. Dragonfly nymphs also hunt the larvae and dragonfly adults the adult mosquito form so they could be bred up in large numbers and introduced as well. You'd also have to enforce strict water receptacle controls within your boundary, therefore remove containers where small pools of water can form after rain. It would also help to provide mosquito lures outside your borders to redirect the mosquito population as well as planting citronella and others plants which repel mosquitoes within your boundary. [Answer] Several years ago this was in the news. The 'Photonic Fence' by Intellectual Ventures - mosquito killing laser arrays which could in theory be made cheaply in scale from scrap DVD burners & webcams. It's been stagnating a little bit maybe, or at least I haven't heard any news on them moving forward w/ any installations or anything. Maybe philanthropists are too squeamish about IR radiation &/or eradicating any species at all to really get behind it & make it happen? (Even though it can select for specific species & mosquitos that bite humans only account for 10% of all species, so killing just those seems like a perfect compromise, IMO) Here's the [Photonic Fence Patent/info Page](http://www.intellectualventures.com/inventions-patents/our-inventions/photonic-fence) you can probably license it from them if you are doing a huge number at scale, but they probably want a lot of money. I don't know the legal ramifications of building your own version for personal use using info you can find about theirs as a reference... but my gut says it's probably fine even without a license, so long as you don't cause them any negative publicity or otherwise irk them. Building said device for under $100 (probably not including tooling) would be extremely difficult, but almost certainly possible if you throw enough time & skill at it. [Answer] Most answers that will kill a large number of mosquitoes would also cause a lot of collateral damage to other native life in the woods you go to. Some would cause collateral, irreversible damage to humans, and probably property as well. You cannot kill all mosquitoes in an area without causing irreparable ecological wreckage. If it were possible, we would not have problems like Malaria and Dengue in the world. You can, however, kill all mosquitoes that come close to you. As some have mentioned, mosquito lasers are a thing. You will kill the odd fly or bee as well, but you won't be causing more damage than you would already cause by stepping on insects by accident anyway. You can also invent some sort of machine that mimics human sweat in smell, and which traps mosquitoes inside it. With small holes, this would be a very specific selector - any other insects that get in will do so by accident, and will be a minority. Just leave a few of these turned on in the area you are going to for a few days prior to your trip, and also during it. Finally, in many mosquito species males make a sound which is inaudible to us, but which tends to scare females (and only the females bite humans). You could have soundboxes making this sound 24/7 - it will not kill them, but it will scare all but the rare deaf females away. Those could be dealt with electric rackets, which would do for a fun camping activity. [Answer] Bring the Ladies! It's a well known fact that mosquitos preferentially bite women, [Particularly pregnant or ovulating women](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1127358/), so bring plenty of lady-friends and they can be your bodyguards. For $100k you should be able to pay for travel expenses for a hell of a lot of your friends. And if you don't have that many friends, you can achieve the same result with strangers. **Edit after feedback and consideration:** This plan doesn't strictly kill all the mosquitos, instead providing alternative targets. However you could use the "blood poison" approach. There are "vaccines" in the works to poison and kill any mosquito that bites a treated person, they're intended to protect against Malaria. Combined with $100k worth of human shields to not only avoid being bitten but kill any mosquitos around it would probably achieve exactly the result you're after. * Human shields mean you don't get bitten * Only blood-suckers die * No collateral damage except for your unfortunate companions * Radius can be achieved by encouraging hiking amongst your group, but coverage is likely to be a bit spotty. For best results, wait in the tent for a few days before emerging, the worst of the biting (and grousing) should be over by then. [Answer] As mosquito's home in on CO2, the easiest route is to place updrafts of CO2 in localised areas (all over the place pretty much). It's hard to home in on people if there is a nearby CO2 updraft or it varies at random continuously. The concentration doesn't even need to be high - just enough (and close enough together) to make prey detection impractical at any range. So it doesn't have to even be lethal to mosquitoes. This isn't an issue for you, your guests, global warming/climate, or any non-bloodsucker. The only critturs attracted specifically to CO2 will almost by definition be those locating prey by their breath, which is basically bloodsucking insects looking for larger beings. Other insects might be affected by CO2, but the concentration would be low, so it wouldn't be lethal - and the amount of time an insect spends in a CO2 updraft would be linked to its bloodsuckerness - non bloodsuckers only enter updrafts at random, and leave them at random, so they get below average exposure even among all insects. Dedicated bloodsuckers on the other hand may be drawn to the updrafts but can't find prey within a varying environmental level of CO2. Humans and mammals of course aren't likely to be affected at all. Even exhaled air contains considerable oxygen, and a higher level of CO2 isn't a problem - if needed the level of O2 could be raised slightly, the same way, which would benefit humans and animal life, but give no benefit or encouragement to bloodsuckers. The environment of course won't be affected - on a global scale any amount used will be microscopic in the context of other sources. A sub-ground distribution mesh based on dry ice or another source, randomised oscillating (both direction and on-off) fans/valves, and perforated pipework directed upward, might be all it needs. You and all you love, including non blood suckers,will feel little beyond normal, and you can admire the mosquitoes as they fly around wondering where the hell their prey is ;-) [Answer] **LIZARDS!** As a Floridian, I feel your itching. Natural solutions are often best, and one of the best natural solutions is lizards. They will eat mosquitos, but they also eat other things when the mosquito population is low (they opertunisticly hunt mosquitos) You should be able to get a substantial lizard population for $100K. The only real downside is that whatever eats lizards in your area is gonna have a field day and probably a population surge. Of course, if you wanted to be more practical 10 cans of spray-on DEET is probably cheaper then $100k of lizards, and may actually work better. [Answer] For $100k you could build "The Oracle"! 1,000,000 lumens of irresistible ultraviolet light up a big pole surrounded by a cage energized with 100kV of electricity. Zap! Mosquito's come get me! [Answer] Mosquitoes home in on the carbon dioxide of your breath when you exhale. Based on the old adage of 'can't see it, can't bite it', the solution is simple: don't exhale for the period of your camping trip. Other solutions include: * Scuba re-breathers, space suits (such as Armstrong wore on the lunar surface). * Large fans to disrupt carbon dioxide concentrations (which has an added bonus, since mosquitoes are poor fliers). * Your own genetic mutation to exhale less or no carbon dioxide. These are all defensive measures of course, guaranteed to have the least impact on the environment. More offensive measures include: * Add birth-control tablets to all the water sources within a specific radius up to three months before your trip. I'm sure you'll be okay with the effects it'll have on you - it's for the greater good, right? * If such changes do not appeal to you, Plan B is to find each mosquito, and remove its wings surgically. They'll still bite you, but they'll have to walk all the way to get to you first. But the best (saved for last) is a patent I'm working on; something I like to call 'The Slasher'. It is a system of cut-throat razors, strategically positioned around the camp site. The mosquito lands, and as it looks from side to side to select its target, it decapitates itself. Enjoy! [Answer] # Giant fans Mosquito are grounded in case of wind (I'd say 10km/h) So, assuming you camp on a flat ground (grassland, beach...), installing giant fans providing constant wind would protect you (without killing mosquitoes). # Anywhere in the mountain Insect can't stand low air pressure Flying animal need air pressure So it is unlikely you find many mosquitoes above 2000m high (from my experience, 1200m is already fine in tropical climate) [Answer] I remember reading an Asimov novel (maybe *The Bicentennial Man*) where, to avoid loopholes in the Three Laws, human designers decided to make them unnecessary: robots are specialized for small tasks and some of them are just robotics birds that prey plagues. You could have in the near future small drones that hunt just mosquitoes, ignoring any other animal. So you could release a couple of dozens of these drones clean the field without affecting any other animal. [Answer] Have you considered camping in a more northern climate? Mosquitos like warm humid evenings (and long walks on the beach) They don't like cold weather, they don't like dry weather, and they die very quickly in either. For 100 grand, hire a few blimps with a giant sunlamp each and warm up a stretch of tundra until it's balmy and nice ]

[Question] [ Cancer works by making cells split and reproduce at an accelerated rate, slowly and painfully killing the afflicted. Its true weapon lies in its ability to surpass the immunity system. As far as I can tell, no matter how the cells of an alien work, there is no way to make them immune to this. So I must ask, is the basic premise of cancer universal? How can I design a species whose immunity system is immune to cancer? [Answer] Cancer is not a disease in the same way as, say, hepatitis. Every cancer is different - and not just e.g. skin cancer versus lung cancer, but really even John's lung cancer versus Peter's lung cancer. The only element all the various types of cancer have in common is that some cell in the body basically turns parasitic, and starts dividing uncontrollably, while tapping the body's resources. Fundamentally, this is a result of the breakdown of the usual role the cell has. This is always a result of DNA damage - of course, the most famous source is from radiation (nuclear instruments, UV light, radioactive carbon and potassium etc.), but the reality is that each cell in your body is in a constant fight against deterioration, most notably from oxidative stress and infection. DNA is quite stable, but even the strongest bond can be broken if you "hit" it forcefully enough. However, there's a limit to how stable DNA can be, because evolution *requires* some kind of instability to introduce new variations in the genome. And that's the real rub. You need something unstable enough to allow changes which are (extremely rarely) positive, and give you a better adaptation to your environment, as well as giving your species as a whole a better resistance to change). This is the same thing that gives you cancer. Okay, you might think, why not make it so that change is possible in *sexual* cells, but not all the other cells in your body? There's two tricky points. One is that different cells use different portions of the whole code, and in fact, two cells of the same type may have different "effective" DNA, based on which of the two variants (one from mother, one from father) of the code is used in any particular cell. If this was visible, you'd appear striped - in fact, it's what causes striped colouring in calico cats. But the main point is even trickier - in most multi-cellular complex life on Earth, the same[1] mechanism is used for dividing sperm cells as every other cell. Even worse, the same main mechanism is used during usual cell operation, not just during division - all those proteins your cells make are first copied from the DNA, which needs to be partially "unwrapped" (which makes it more vulnerable). Why not have a different mechanism? The fun part is, there have been different mechanisms in EarthLife's past (and they're still present in many organisms). It's just that DNA is the best we've got - evolution didn't stumble on anything better yet. Our cells are full of mechanisms to prevent cancer, and our bodies as a whole are as well. The problem is that there's so many cells, dividing (and dying) all the time - even with all the repair mechanisms, once in a while, a cell goes "rogue". Almost always, it's very quickly destroyed from the outside (or happens to starve etc.). Only when *all* the mechanisms fail do you get a tumour, and even then, it's not necessarily the "real bad cancer that kills you eventually" - most growths are not deadly. You need a growth that can "bleed your blood dry" of nutrients, or that interferes with normal functioning of the rest of your body (e.g. blocking blood passage, destroying surrounding tissue). The same things that enable cancer are really the same things that are required for life to work (and evolve) in the first place. Even if it were physically possible to make a data structure that's impervious to all damage, you need to "damage" it in order for cells to divide, and possibly to read the data (that's the way it works with DNA). If it's hard to do that "damage", you will grow slower, and the changes in the populations will be rarer - in other words, some other thing, faster growing and/or more adaptable, is going to eat you or starve you. No repair mechanism can ever be perfect, because the damage can always occur in the repair mechanism itself. Our own bodies' repair systems are incredibly reliable (it's necessary for any large, long living multi-cellular organism), but they're applied very often. And of course, we're under pretty much constant attack by other organisms that seek to change our body processes for their own benefit (various parasites including viruses). The best you can do is remove as many causes of damage as possible. For example: * The aliens live deep in the ocean, and are entirely shielded from most radiation. * There's no free oxygen (and other strong oxidants) in their environment. * There's no parasites smaller than your own cells, or parasites that overwrite your own genetic information (e.g. viruses); this is a bit tricky - you'd need something that reliably destroys small things without damaging bigger things. * The alien's body is resistant to systemic changes and localised damage. For example, cancer is quite common in plants, but it has no way to spread systemically, and damaging one part of the body rarely does significant damage to the whole. This can make some quite alien aliens indeed ;) If you take an ant colony as a single life-form, this is their strategy against cancer as well - cancer doesn't spread *between* individual ants, so unless it affects the queen, the colony survives. * The metabolic rates of everything on their world are much lower than ours. This basically gives the repair mechanisms more time to fix any problems before they grow too much. This is basically how chemotherapy works - it prevents all your cells from dividing (which causes the infamous "hair falling out" etc.), which hits the cancerous cells by far the most, since they divide "unrestricted" under normal circumstances. * There's a systemic repair mechanism ("genetic white cells/antigens") that continually identifies any deviations from "standard" genetic data, and marks the cells for termination. Of course, this would be extremely expensive and might cause you quite a bit of trouble if that's what gets broken - your marker would start marking every healthy cell for termination, ouch. It might be interesting for your story though - for one, it might be something humans might want to adapt to their own physiologies, and two, it might create a "cool disease" in the aliens that could be transferable to humans with disastrous effects. And with a repair mechanism like that, the aliens might lack one of the mechanisms that causes biological ageing - potentially making this whole thing even more attractive to humans, with promises of "immortality". [1]: Okay, not *exactly* the same - but they have the same weak point, DNA replication and transcription. DNA is at the center, not the exact replication process - you need information storage strong enough to withstand environmental damage, but weak enough to allow replication and transcription. [Answer] Cancer is typically caused by improper [DNA repair](https://en.wikipedia.org/wiki/DNA_repair). The gist of it is that cellular DNA becomes damaged in such a way that a repair to the DNA of the cell fails to restore the original DNA, and also corrupts it in such a way that other cellular mechanics to encourage programmed cell death under these circumstances do not trigger. Now, the human body repairs a *lot* of damage to cellular DNA every day, and the odds of this kind of improper DNA repair happening, and it having the necessary changes in DNA to become cancerous, is fairly rare (otherwise everyone would have cancer from the day they were born). It is a statistics game, however, and unless something else kills us beforehand, statistically speaking, everyone will get cancer. Cancer spreads rapidly by several mechanisms, but one of the key ones is the activation of Telomerase, a Ribonucleic Protein that add a telomere repeating pattern to the end of a DNA chain (typically these patterns naturally limit the number of times a cell can divide, the Telomerase removes this limit). Without a mechanism to limit the number of times a cell can divide, they divide indiscriminately and constantly. Cancer tends to bypass the immune system because it is composed of cells from the same host, and is often recognized as part of the healthy body (one of the research pathways to cancer fighting drugs is aimed at flagging cancer as a foreign body). In theory, a virus or other method could be devised to inflict a cancer-like disease on an alien race. However, depending on how their biology works, it may or may not have the same effect. They could be different enough on a biological level that they would be immune to cancers, and the condition would never occur. [Answer] Cancer is evolution wrecking your life. That is, many of the cells in your body are capable of dividing and making more cells like themselves. Like full-fledged organisms, this division sometimes goes awry, producing mutant cells. Some mutant cells are are unaffected by the mutation. Some are unviable and die on their own. A few would thrive, but the immune system catches them and kills them. A smaller few thrive and are not caught by the immune system but reproduce at a modest rate, producing various minor benign tumours. Once in a while, a mutant arises that can evade the immune system and replicate aggressively. This is cancer. And once you have cells replicating aggressively, evolution kicks in: the ones that are better at dodging the immune system live longer and have more descendants. The ones that are better at dodging cancer treatments live longer and have more descendants. The ones that are better at spreading all over the body live longer and have more descendants, and may well kill you. A few are even able to attack other individuals (devil facial cancer, canine venereal cancer) or even other species (there's one in molluscs): cells from a multicellular organism have turned into a pathogen. Really it's a miracle that cancers are as tractable as they are. Because they all start as minor modifications of the human genome, and because the immune system is pretty good, there are a relatively limited number of weak points where cancer frequently arises, which is why cancers often fall into recognizable types. That said, every cancer is different, particularly as they become advanced, because the population of mutant cells is evolving to resist everything thrown at it. Could an organism be cancer-free? Well, I don't want to say too much about really wild ideas for organisms (energy structures, silicon life forms, informational organisms) but terrestrial organisms are mostly made from cells, which at their hearts want to be independent self-replicating organisms. But some kinds of human cell intentionally cannot replicate: red blood cells are the most obvious example, since they do not even have nuclei. The cells that make red blood cells, though, they can go bad. So an organism whose cells were all, or almost all, designed so they couldn't self-replicate would be quite resistant to cancer. But it's got to repair itself somehow, and if that repair mechanism goes wrong, it will damage the organism. It won't be a self-replicating kind of damage, but such a centralized repair mechanism would have to be capable of much more extensive repair on an organism whose pieces don't repair or replace themselves, so a broken repair mechanism could do much more damage. Single-celled organisms (some of which can be visible to the naked eye) are like this - they don't have any sub-parts capable of replicating themselves, but their repair mechanism is also completely centralized, and they mostly survive by spamming the environment with easily-killed copies of themselves. I'd say that cancer or something like it seems likely in any organism that comes out of a process of evolution. Obviously organisms can be more or less vulnerable to it, but being less vulnerable to cancer probably also comes with being less adaptable (not to mention the risks of having a too-aggressive immune system - autoimmune effects produce all sorts of things from type I diabetes to arthritis). [Answer] ***I disagree with the accepted answer.*** ***My Short Answer:*** Any system that can evolve will be subject to cancer. Cancer is driven by the same entropy increasing mechanism that drives evolution itself. An evolving system does not have to be DNA based, RNA based or organic/living at all. All that is required for a system to evolve is: 1) It must have pattern that reproduces or is reproduced, 2) the pattern must be mutable. 3) Given the right environment unit N must be able to produce the next generation with at least with at least N+1 units in the next generation. 3) The specific configuration of the pattern must be able to affect the rate of reproduction. 4) The mutated pattern must increase the overall entropy of the universe in order to persist. This is why we can use genetic algorithms with oft times produce entire unexpected results i.e. an antenna controller "grown" with generic algorithms turned out to work only in one place, it's original location on the lab bench. Turned out, it evolved to used a part of a nearby piece of unrelated equipment to enhance its own antenna. Entropy driven natural selection operates independently on multiple levels of the same organism. When it causes a subunit of a larger system to reproduce uncontrollably and to the detriment of the larger unit, we call that a cancer. Just as natural selection is independent of pattern storage or reproduction mechanism, so is cancer. You will get cancer in a DNA based system, RNA or some other natural organic process e.g. prions, or technological systems both in hardware and software e.g. the grey ooze nanobots. (I have an acquaintance who was using agent modeling for a simulated ecosystem. One agent mutated outside the set the bounds and it ate the rest of the ecosystem entirely. The robots will always rebel.) ***Long Answer:*** Evolution is driven by the increase in universal entropy generated during the creation of complex structures and systems. The easiest why to think about the phenomenon is to compare the lengthening of wavelength in a planets albedo (the ratio between the amount of light of specific wavelength striking a planet to the amount it radiates. Simplistically) The lengthening of wavelength means less work can be performed and thus the amount of entropy in the universe over all increases. The creation of complex organic molecules, systems of such molecules, then living organism that constantly build complexity and while doing so, produce more entropy than say, a rock sitting on Mars. (BTW: This is also the answer to creationist who say that adaptation in natural selection is tautological. It's not, only adaptation that produce more entropy than existing or competing structures will be selected.) Life on earth is composed of nested levels of reproducing patterns or units each of which becomes a unit of selection i.e. a pattern upon which natural/entropic selection can operate on. Each larger level is the environment in which the subunits "compete". E.G. Almost all genes come in slightly different versions called alleles. Alleles compete with each other for the gene's position in the greater DNA structure, the loci. There is a form of gene cancer in which an allele inserts multiple copies of itself at its loci. Almost always fatal but its clear that some extant genes started out as "cancers". All genes cooperate to create the cell, the greater environment in which the genes exist. Cells in turn cooperate to create organisms, organisms (especially sexually reproducing ones) cooperate to create strains and species. Cells were the original organisms and multicellular organisms are collections of structures that once reproduced themselves to the maximum extent possible (which generates more entropy.) A tremendous amount of cellular mechanism exist which do nothing but control the reproduction of the cell. The vast majority of cells have all their reproduction switched off and most new cells are split off from stem cells. Most cancers arise from the failure of reproduction suppression in stem cells because stem cells have most of their safeguards switched off so they can produce new cells. They more easily revert freeform cell type that does nothing but reproduce. That's why its hard to permanently "cure" a cancer, you have to kill every single mutated stem cell. It's easy to see how even self-reproducing technology will turn cancerous. Nanobots or evolving software will be just as affected by the 2nd law driving them to increase entropy, so eventually they will mutate to a form that will increase entropy by reproducing without regard to any larger systems. If software can turn cancerous, then alien biologies will as well. It doesn't matter what they're composed of, as long as they can evolve, which they must to exist, then eventually, they will have units that will mutate into cancers. [Answer] Assuming the alien life form is multicellular, it should definitively know cancer. Cancer is basically a defect in the mechanism that controls the cell division. Cell division is absolutely essential for growth and reproduction. Also, the multicellular life will have evolved from single-cellular life, as that is the simpler one. Singe cell organisms divide as long as they have the resources, as that is the key to evolutionary success. Therefore the original program of a cell is to multiply uncontrolled; basically the cancer cell is the original. The control mechanisms are then "bolted on" to enable multicellular organisms; however, any limitations have to be limited for gametes, or else the organism cannot multiply unlimited; a species that can only generate a limited number of progeny generations will die out. So evolution cannot simply destroy the mechanisms that allow unlimited cell division; it has to make sure that it is limited to be activated only when generating offspring, and then again deactivated in the offspring except when generating the next generation. So any multicellular life will have cells which in principle can multiply without limit, but which have mechanisms to prevent that in most cells, so that cells only multiply in a controlled way when the organism needs it. But whenever there's such a mechanism, it can be damaged by environmental influences (ionizing radiation — that one should be quite universal —, certain chemicals — which probably depend on the details of the biology —, possibly pathogens — likely organism specific —, and maybe other causes). And if the control mechanism is damaged in the right way, it should result in uncontrolled growth of cells. That is, cancer. However note the one condition I've mentioned above: Multicellular. For example, a giant intelligent amoeba would not get cancer, simply because it has no cells that can get out of control. It only has one (giant) cell, that is itself, and cell division is just how that amoeba multiplies. Now of course that raises the question whether a giant intelligent amoeba would be possible, but it was just an example anyway. Any way to make those life forms not built out of individual cells would work. [Answer] I would use this interesting little guy for inspiration. <https://en.wikipedia.org/wiki/Deinococcus_radiodurans> The important bit: > > In its stationary phase, each bacterial cell contains four copies of > this genome; when rapidly multiplying, each bacterium contains 8-10 > copies of the genome. > > > This bacterium also has extreme DNA repair mechanisms. These same mechanisms which make it highly resistant to ionizing radiation would also theoretically help prevent a higher order species from getting cancer. [Answer] Any multi-cellular organism can get cancer. However, depending on how alien you're willing to go, it might be possible to devise an organism that is much less susceptible to its effects. Plants, for instance, can get cancer, but are generally not harmed by it. Did you ever see a tree with a little burl or knot on it? That's a tumor. But since plants don't have localized organs or a structured body plan that can be disrupted by a tumor, it doesn't really do anything to their health. And since plants are rigid, the tumor doesn't metastasize like animal cancers do. Anything amorphous, unstructured, or capable of full-body regeneration will not be especially bothered by a little piece of itself multiplying uncontrollably. As long as it isn't operating like an *animal*, you can probably find a way for cancer not to bother it. Hive minds are another possible route - the individual animals can still get cancer, of course, but the death of any one of them won't affect the organism as a whole. It is also possible that an animal species could naturally develop a more effective biological means of detecting and killing cancer, if resisting cancer was a major factor in its evolutionary fitness. The main reason why most species on Earth don't bother is because there's little reason to - the chances of being killed by something else is so much higher that cancer isn't really worth looking into, especially since the anti-cancer mechanisms might cause drawbacks in other, more important areas (being more careful with cell division might mean slower growth and healing, for instance). It's only in recent times, where we've dealt with most of the other things that can kill us, that cancer is even an issue, and evolution hasn't caught up yet. [Answer] Cancer is caused by mutations to critical parts of a cell's DNA causing it to reproduce at an uncontrolled rate. Usually multiple mutations must accumulate over successive cellular generations in order for a fully malignant tumor to develop. Human cells are genetically "programmed" to correct mutations (DNA repair) and to kill themselves if their DNA is irreparably damaged. But if the cell's suicide or repair mechanism is itself broken by a mutation, then further mutations can occur, leading to cancer. The immune system is tasked with killing things that it doesn't recognize as human. That's the problem with cancer that you pointed out: even if a cell mutates to rapidly reproduce and grow into harmful tumors, it will still usually register as human to an immune cell. There's actually a really simple\* solution to this problem: unify the DNA repair and cellular recognition pathways. \*(Actually unbelievably complicated, but "simple" in that there is a very simple underlying idea). There are many ways this could be done: transcribe short portions of the genome that are important for DNA repair, transport them to the surface of the cell, and use them as recognition sites for the immune cells. If enough of them don't match, indicating a mutation in the genome, the immune cell destroys it. Alternatively, the specific proteins and enzymes involved in DNA repair could themselves be moved to the surface of the cell and used as recognition sites. Maybe the immune cells could even present them with short fragments of DNA and see if they repair them correctly. The details are impossible to flesh out mentally, but the general idea seems perfectly biologically plausible: **Force the cells to constantly express that they are reproducing and repairing their DNA correctly, or else the immune cells explode them.** This wouldn't prevent mutations from occurring, but it would prevent them from *accumulating*. This should be enough to stop cancer from being a problem. Technically, this scheme wouldn't categorically eliminate cancer, since there could always be a mutation in the immune cells that breaks the recognition mechanism--but now we're talking about highly specific complementary mutations occurring in unrelated cell types in different tissues on the body, and enough immune cells being affected to break the system. The odds of the necessary mutations occurring in both the potentially cancerous cell *and* in a majority of the body's immune cells is so low that it makes cancer as we know it virtually impossible. Such a system would be remarkably unlikely to evolve on its own. A species that prevents mutations in its DNA won't be very good at evolving and will probably go extinct, so I imagine this mechanism would only appear after millions or billions of years of having a normally evolving immune system (the DNA repair mechanisms have to appear in the first place and evolve until they're good before they can be "locked in" as I'm describing). But I don't think it's too much of a stretch considering [how outrageously complicated the human immune system already is](https://en.wikipedia.org/wiki/Immune_system). Don't expect such a system to be commonplace among alien races, but given an entire galaxy of potential and maybe a few billion years of an evolutionary head start, and I think it's believable. [Answer] I remember seeing a presentation on YouTube about cancer research. Cancer is not *just* uncontrolled reproduction. Sometimes you get such simple tumors, but they are not the really bothersome things. A tumor that calls for its own blood supply and later metastasizes is the real killer. I don't remember who, but the speaker pointed out several things that cancer does that's not simply malfunctioning, but is *running the wrong program*. What if an alien (or nanotechnology) did not keep the whole program in all cells? Rather than deactivating parts and turning on others as cells differentiated, what if the daughter cell was only given the programs it needed for that role? A mature liver cell would not be able to run subroutines meant for use in growing an embrio. It simply would not be available to be run! An alien multi-cellular life form might be so different as to make the very concepts not apply, even though we think of them as assumptions and can't easily imagine otherwise. On some previous answer, I showed an example of cells that have two nuculi and use different DNA for sexual and asexual reproduction. What if *that* became the basis of a multi-celled life form? Dividing within the body to keep renewing epithilial cells could use a different mechanism, and it only passes on the subset of DNA. [Answer] Cancer is universal, but not to biological life. As many answers have stated, cancer is a corruption to dna. However, dna does not define life. As a professor once stated when he was mentioning number theory's once infamousness for being useless, "dna is a form of encryption. It is basically a tiny von neumann architecture". If you did not understand what that means, here is it in very simple terms: DNA *is* a form of programming. So, is cancer universal? Yes! The very device you are using proves it. For instance: Hacker corrupts data in a program? That is cancer. Random radiation switches a bit? That is cancer. Program has a glitch that causes the computer to crash? That is cancer. So... Can you make a species that is immune to cancer? Alright, fine then. Create a race that is so alien and so otherwordly that their celullar structure does not function on any form of logic. That: Or make up a completely blatantly ridiculous explanation as how cancer can be completely guarded against (complete subquark isolation barriers between cells might prevent anything from damaging to them, but then there is an issue of flat out immortality). Since anything with any force could manage to damage a cell (even a ridiculously well aimed punch might do it), your only option would be to devise a system of logic that is capable of preventing any corruption. Good luck. Your solution essentially leans on the following: > > devise an explanation for the existence of a program that if corrupted in some way, will either 100% repair itself or terminate. > > > I have to say, I really love this question. [Answer] Adding to the answers of @celtschk and @Anne: They both say that cancer is an inevitable consequence of having a multi-cellular organism. One can imagine that other species have more cancer or less cancer than us, but they *will* have cancer. Of course, as medical science gets better, we get better at detecting cancer in an early stage, and we also get better at curing cancer when we find it. We will probably soon reach the point where cancer no longer is a big deal, just a matter of seeing your doctor regularly. Total immunity is probably impossible, but we could certainly be less cancer-prone than we are. Multiple redundant systems for mutation detection leading to repair or cell suicide would help. Actually, we already have that, but they aren't quite redundant *enough*. The problem is that evolution leads to "planned obsolesce". As we age, we accumulate damage from all sorts of sources. From a evolutionary point of view, it is easier to just discard one generation when the next generation is ready, rather than putting lots of effort into repair systems. Any species which is fresh out of their biological evolution era is likely to be in a similar situation. As the species mature and starts modifying their own genome-equivalent, they can get away from this and become more robust. This will not only improve cancer defense but also delay aging in general. Story idea: Write about the one single person on the planet dying from incurable cancer in some distant future. It would have to be somebody who have both skipped their medical controls AND have some complications that makes the cancer incurable. Scientists are working day and night to overcome these complications, but will they succeed in time? Stray thought: A species whose global religion tell them that cancer is a sign of divine wrath, and who always kills the whole family of the diseased. This would give a strong evolutionary pressure to have strong cancer defense. Never totally immune, but far better than us. [Answer] From a mathematical point of view, I would suggest that cancer is indeed universal. Seeing all the the cell processes together (in one life form) as a huge (programming) code, one could view cancer as a severe corruption of some lines in the code caused by error-inducing noise. Concretely, this 'noise' is just altering of the DNA by radiation, heat, etcetera. Assuming that this noise is unavoidable, immunity for cancer means that the code of the life form is able to recognize (and recover) mistakes in his own code. This 'self reference' already gives an indication that such a code is not possible to exist. As an example - there are some known parts of the life-form code that recognizes mistakes; proto-oncogenes regulate programmed cell-death (apoptosis). The main problem is that these genes can be corrupted too, which is indeed often the case in many forms of cancer. There is even some mathematical proof that such a self-repairing code is not assumable to exist; it is called the 'Halting Problem'. Roughly translated to this context, it says that there is no program that can see whether some life-code goes on infinitely (see this as 'cancer') or halts eventually (see this as 'normal cell processes'). [Answer] Elephants and Mole-Rats are both immune to cancer. Their bodies evolved to kill or cannibalize cancer cells as soon as they find them. But cancer is not a disease: it is an error in the mechanism of multi-cellular systems. All you have to do is make aliens that don't experience these errors or make them immune like elephants and rats on Earth... [Answer] As cancer is caused by self-duplicating cells, you could easily create a creature that does not require any duplication of cells, thus being immune to cancer. The drawback of no self-duplicating cells could be that once a cell is dead it wouldn't automatically be restored, if the alien race is synthesized and put together once without an internal self repair mechanism it would not develop cancer. The immune system would probably have to be able to keep all existing cells alive instead of trying to kill cancerous reproductions. [Answer] My answer will serve as a complement to the user TechZen: His reasoning that "the larger the biological system, the greater the degree of entropy it has to deal with, for example, the more cells an organism has, the more chance it has of suffering a genetic error that leads to cancer. So the maximum proportion that an organism can take is related to the maximum degree of entropy it can "fight"" was the reasoning that science for a long time had, taking the example of cancer: the more cells an organism has, the greater the chance of him getting cancer, after all, the more cells you have, the more genetic material you have and the more genetic operations you carry out We find that large organisms like elephants, giraffes, and the blue whale (which is the largest organism that has ever existed in the entire history of life on the planet) simply have a ridiculously low cancer rate. To give you an idea, to this day not a single blue whale has been found with cancer. This contradiction is called the [Peto Paradox](https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-017-0401-7). There are two hypotheses that try to explain why blue whales do not develop cancer: the first is that they have a sophisticated biochemical mechanism that is much more efficient than ours in correcting genetic problems. And the second is the hypercancer hypothesis, I'll send you more about it below From humans to hydra: patterns of cancer across the tree of life - Albuquerque - 2018 - Biological Reviews - Wiley Online Library <https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12415> Massive animals may hold secrets of cancer suppression | Nature <https://www.nature.com/articles/nature.2013.12258> (Here begins the first hypothesis as to why blue whales do not develop cancer, the rest was an introduction) Peto’s Paradox: Evolution’s Prescription for Cancer Prevention <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060950/> (Here about the second and craziest hypothesis: hypercancer) Why don't all whales have cancer? A novel hypothesis resolving Peto's paradox | Integrative and Comparative Biology | Oxford Academic <https://academic.oup.com/icb/article/47/2/317/719209#12636921> Oh, and another thing, rats have a cancer rate basically identical to ours, and they're much lower [Answer] Cancer is when the mechanism that controls the division of cells fails, causing cells to rapidly divide. I do not know of any earth creatures that are immune to cancer, although there are some that almost never get cancer. One example is the [axolotl](https://en.wikipedia.org/wiki/Axolotl). This weird salamander can regenerate his limbs, and almost never gets cancer, and has actually been looked into as a potential way to develop a cure for cancer. Even if your aliens aren't immune to cancer, they can be nearly so. ]

[Question] [ **Locked**. This question and its answers are [locked](/help/locked-posts) because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. There are plenty of threats out there that could terminate all life on our little planet in varying amounts of time (Solar flares, meteors and supernovas to name a few). Are there any disasters that could kill all (intelligent) life on Earth but leave astronauts in low orbit alive for long enough to attempt to come back down to earth? (and restart society?) Can you describe those scenarios into some detail and explain why exactly everyone on Earth dies, how the astronauts survive and what the state of the Earth is when they return? For this question you should assume roughly current technology and Earth as the location. Judging from [how often food is sent up to the ISS (every 2-4 months](http://en.wikipedia.org/wiki/List_of_unmanned_spaceflights_to_the_International_Space_Station) and their [45-day food reserve which they have almost needed to start digging into](http://www.theguardian.com/science/2004/dec/10/sciencenews.spaceexploration), I'd say 8 months is a reasonable, optimistic guess as to how long the astronauts can wait until they come back to Earth, I'd be happy to be corrected on that number though. **note:** The amount of survivors doesn't necessarily need to be 3 of course. In fact, I would personally even prefer more than 3 members of the human species to survive. [Answer] I would say none or close to none. The main problem is that being in space isn't very different from being in some confined places on Earth (with regard to isolation). For example * submarines, * some very remote areas, * shelters, * some deep caves, etc. * arctic stations. So, for that (i.e. everyone but those in space die) to happen, it had to either * spread over the whole world faster than ~4 months (because of the food transfer), or * be selective (target people on Earth and not care about astronauts). Moreover, any calamity makes people hide and take shelters, so it also has to be sneaky. For that reason atomic apocalypse, asteroid strike, etc. in my opinion won't work. If it was to be a disease, it would have to be dormant at first, so that people wouldn't notice and there would be a possibility to infest all the humans (but not the astronauts) and then transform and kill. Bio-engineering, nano-machines -- all such things seem like a big stretch (with very high probability something would go wrong and the thing would be discovered before the outbreak). There's a short story [Second Variety](http://en.wikipedia.org/wiki/Second_Variety) by Philip K. Dick which considers quite similar scenario, where the genocide is caused by self-modifying robots. However, note that such robots, which aren't able to reach space, aren't able to reach into shelters, submarines, etc. Most of ways dealing with that will also kill your astronauts. Of course we could make the plague selective, i.e. explicitly target people on the Earth, e.g. an AI which has been programmed to kill people only on the Earth and nowhere else (e.g. a plane would be safe until it lands). Or, you could try to test some new antenna, which (for whatever reason), when turned on in space (on the Earth was fine) generated some yet unknown radiation that killed all the sentient life on the planet (the astronauts survived, because they were on the other side of the antenna). However, if you don't mind altering your story: * the astronauts come from some long mission to find the Earth unresponsive (but for some automatic computer navigation data feeds). * I think that having *some* survivors on the Earth would make the story more interesting, as there would be more tensions and unexpected power-struggles; it close to impossible to destroy *all* the shelters, but it might be relatively easy to describe how most of them fell (consider reading the [Silo novels](http://en.wikipedia.org/wiki/Silo_(series)) by Hugh Howey). I hope this helps ;-) [Answer] Plenty. * **Asteroid** A sufficiently violent impact at a time where the resulting debris doesn't intercept the stations orbits would wipe out life but leave people in orbit alive. * **Volcanic Winter** Volcanic activity obviously would not affect astronauts at all. * **Plague** Confined to the biosphere/atmosphere. They should be careful no-one has brought it on board though. * **Nuclear War** Let's hope no-one lobs a nuke at the astronauts. * **Toxic Bloom** An algae bloom forms covering the oceans and vomiting out a nasty toxic chemical, rendering the air everywhere unbreathable until the bloom kills itself. * **Rogue AI** A rogue AI goes Skynet and kills everyone. People in space are not its concern. * **Ragnarok** Damnit, the vikings were right all along. The astronauts will be fine until Fenrir devours the sun. **Conclusion** They would all need to be pretty drastic to wipe out absolutely all life on earth but with the possible exception of Nuclear War and Asteroid Impact they would have zero chance to effect bodies in LEO at all. The astronauts are unlikely to be completely alone though. For example submarine crews and some military bases might survive the toxic bloom. A meteorite killing absolutely everyone would leave the whole planet uninhabitable for quite a while, etc. The Nuclear War, Volcanic Winter, Rogue AI and Ragnarok are all unlikely to be over in 8 months so we can rule them out. The Asteroid, Plague and Toxic Bloom are all possible to have the level of impact needed and be over in that time, although 8 months really isn't a long time for the entire process to start and finish. You'd also have to worry about lingering effects such as Impact Winter from the Asteroid, possible infection from the Plague and resurgence of the Toxic Bloom. [Answer] One possible scenario is the release of unrestricted self-replicating nanomachines. They're a popular doomsday scenario to illustrate the perceived dangers of scientific progress and are colloquially called "grey goo". You start with a single machine, invisible to the naked eye, that is capable of producing an exact copy of itself by breaking down available resources. Due to the way exponential growth works, the colony will rapidly overrun the earth. [Wikipedia](http://en.wikipedia.org/wiki/Grey_goo) quotes Eric Drexler: > > Imagine such a replicator floating in a bottle of chemicals, making copies of > itself…the first replicator assembles a copy in one thousand seconds, > the two replicators then build two more in the next thousand seconds, > the four build another four, and the eight build another eight. At the > end of ten hours, there are not thirty-six new replicators, but over > 68 billion. In less than a day, they would weigh a ton; in less than > two days, they would outweigh the Earth; in another four hours, they > would exceed the mass of the Sun and all the planets combined — if the > bottle of chemicals hadn't run dry long before. > > > You can tweak the impact and reach of this goo by adjusting their reproduction process and what resources they consume: metals and biomatter, carbon, molecules or even atoms. So you could limit the goo to landmasses or let them overrun the oceans. Whether they reach the atmosphere likely depends on their granular size and how much of the earth they consume. For your scenario you'd have them ignore bare rock to there's an earth left to return to. You'd also have to tweak the robot's programming to leave plants or certain animals alone if your space explorers want to have any hope of survival after their return. After the goo has finished converting all available matter, they will run out of energy and eventually deactivate. To quote Wikipedia again: > > Gray goo nanobots need a source of energy to drive their replication. > For efficiency reasons, the energy would likely come from oxidation > and other chemical reactions on the organic matter itself—a process > which in organic life is known as digestion—rather than from an > external power source. In such a scenario, gray goo replication is > self-limiting. The more organic material that the grey goo consumes, > the less remains available for further consumption. After exhausting > available organic material within a local area, grey goo would > experience a population crash in that area, slowing or ending its > outward spread. > > > Note that any robot with a sufficiently efficient mechanism of self-replication that is mobile enough or small enough to propagate throughout the entire planet in waves will work. Even if you scale them up to the size of the "Claws" from Philip K. Dick's Second Variety (as mentioned by dtldarek), the grey goobers would be distinct from those in that they're autonomously self-replicating, instead of produced in factories. They also wouldn't have an instinct for self-preservation beyond an automatic consumption of matter. They'd consume all available life then expire themselves. [Answer] The only scenario I see is plague. You need a disease that spreads **extremely** well but doesn't appear worse than the common cold. It will have to happen during the northern hemisphere winter so there's personnel exchange with the antarctic bases. It's second--lethal--stage will have to occur after a long enough period that groups like the boomer crews have been exchanged. While it would have to be an airborne vector it would need to be something that can't live very long in the environment so resupply rockets wouldn't bring it to space. Remember, sick crews don't fly--if you've got everyone down with a cold no manned rockets are going up. All the other nasties that have been mentioned upthread would still have catastrophic effects long past the maximum endurance of the crew. I can't imagine this as anything but a bioweapon. Perhaps some group thought they had a vaccine... Or maybe they did have a vaccine but the world's intelligence services figured out where they were holed up and someone pushed the launch button. [Answer] Going a little more fantastical, to add to the excellent answers already present. I don't know if these are feasible: 1. **Breakdown of Earths protective magnetic Field + Deadly comsic radiation.** Stations in Orbit are usually heavily shielded against comsic radiation and Earths magnetic field and the atmosphere usually do the same for us. If this natural shield would somehow turn off for a Month, some kind of cosmic radiation could kill off everyone, who doesn't spend the whole week in some kind of shielded environment like a space station 2. **Some Kind of Electrical Impulse stopping the heart/killing all brain activity** If there was some kind of deadly electrical wave-pattern, which could be emitted by lets say Cell-Phone towers, it would kill almost everyone if the cellphone-network-coverage on the planet would be high enough 3. **Devastating solar storm** which will roast the whole planet and burn everything to a crisp, if the Spacestation can maneuver somehow and stay on the shadow side of earth long enough, it could maybe hide in earths shadow, while earth is burned - in 24 hours the whole planet would be dead... 4. **Pre-programmed mass-suicide** There could be something which is pre-programmed in all humans and activates at a certain time, letting all people burst out into a violent rage for 24 hours killing everyone and themselves in the rage. But some kind of powerfailure/sleeping gas/plot device knocks the people on the space station out for 24 hours, so they cannot commit to it. I know some of these are pretty far reaching, but maybe they can be refined and used as a plot seed. Otherwise I recommend [exitmundi](http://www.exitmundi.nl/) (warning, page is highly addictive) [Answer] **A bioweapon spill or war** One of the things that would affect only the planet below and not humans in LEO would be an airbourne virus or plague. I'm going to take a few liberties with 'Current' technology here, but what I suggest is feasible and essentially boils down to 'incredibly virulent bio weapon'. As the virus is a weapon, then either it gets out because of an accident or it is used in anger and targeted (in large amounts, all over the globe). It could be presumed to be natural although for me, this is more of a stretch (ever seen that film with Mark Whalberg where the trees make everyone immediately suicidal? I spent most of it unable to suspend my disbelief). **astronaut safety** Obviously it would not be able to leave the atmosphere unless ferried up to the astronauts with a supply shipment somehow, or the group who unleashed it targeted them. So they could be considered safe (or they dodge the missile somehow). **survivors** Of course hermetically sealed shelters, submarines, etc would not be affected by this, and there are problems with the timeline - unless you take some creative steps with the nature of the plague. Drawing some inspiration from the idea of a virus bomb similar to the ones depicted in the warhammer 40k books, it could be engineered to destroy all life and also circumvent normal air filters (by being too small or by being able to dissolve rubber on contact, etc..). Being engineered, it burns itself out quickly and becomes harmless, so the astronauts won't get infected when they land. If it was virulent enough it could explain why normal gas masks and weakly sealed shelters would fall - but it still leaves stronger stuff like millitary bunkers, submarines etc. This is where the engineered part comes in - This allows you some scope to explain how hardened installations were overcome, they could have been hit directly with warheads containing the virus. **still survivors?** If the virus were to essentially speed up decomposition, and it was a single event in time rather than spread out, you could also play with the idea of setting the atmosphere on fire due to the huge amounts of released gas - plausibly this might take less than 8 months to burn out but as nobody has ever done it before (thankfully!) it may take more or less time. Also, if it was transferrable through water aswell as air, it could kill all ocean life aswell as take care of those pesky submariners by infecting the water around the sub, which is then taken in and distilled into fresh water (most subs apparently do this, and also can use it for CO2 scrubbing.) That's your vector to kill off the submarine crews. **What would it be like?** *If you burn the atmosphere:* The oceans may have boiled? This would take care of the submarines. Otherwise, you essentially have a blackened and charred wasteland with no surviving organic life and no oxygen left in the air. Pretty hellish. *If you don't burn the atmosphere:* Everything organic is dead and decomposed (at an optionally accelerated rate). The oceans are filled with decomposed fish guts and other matter, and the atmosphere may have alot of methane in it. As no world-ending firestorm happened, the infrastructure, technology and buildings are still intact. Also, canned food might be, depending on how virulent the virus is. [Answer] None. As Martin-Mueller speculated, there are, in fact, a ton of jobs that have to be done planet-side in order for any of our currently existing manned spacecraft to be able to return safely. With everyone on the planet wiped out, the astronauts would be left stranded with no way to make a successful reentry. This could be eliminated in worldbuilding by speculating a near-future spacecraft able to make the return on its own (the modifications needed from current spacecraft really wouldn't be all that extreme), but any such technological changes would change the other assumptions the question relies on as well. However, if you're willing to allow for just a few planetside survivors, that changes the picture quite a bit. The astronauts could even still be quite isolated, since those who help them down would, mostly, not need to be anywhere near the landing site, and the few who did have to be at the landing site might be contrived to succumb to the residual effects of the disaster shortly thereafter. Even communications with the helpers, which were achievable from orbit overhead, might be cut off once line of sight is lost when they land, depending on what method they're using to communicate (the space shuttle, for example, has a wide variety of communications gear available to it, plenty of which would have this problem if they were what the helpers had available and undestroyed). [Answer] I'm a little worried about what you are planning... I see a few additional problems other than what has already been mentioned. Even if we could get the spacecraft to return to Earth safely without ground support, after spending 8 months in zero gravity, their muscles would be very weak. It would take some time before they could move around on their own, during which time they would be pretty helpless. And then if they did survive, rebuilding society would be difficult for such a small group. Especially when it comes to reproduction. If the population is too small, inbreeding would wipe them out in a few generations. And according to <http://www.howmanypeopleareinspacerightnow.com/> (which may be my favorite domain name), that population would be a grand total of 6 right now. In fact, that seems to be the total capacity of the ISS. But even that isn't the real number to be concerned with, as the crew does not exactly have an even male/female ratio. Most missions appear to be entirely men, so there goes any chance at future generations. Currently one of them is a woman, but even there, the second generation would all be at least half brothers and sisters. All in all, I would recommend seeing if you can get a refund on your trip and whatever doomsday devices you have already purchased. [Answer] This scenario is discussed quite a lot: we are running out of fossil fuel, and the governments expect those to end in about 30 - 40 years. People get concerned, and we will start the *Fight for our resources*. Of course, those could lead to some of the causes that Tim-B mentioned. I think your guess is pretty precise... By the way, there are constantly six astronauts on-board the ISS. ~Itay [Answer] This exact scenario is the framing situation in the classic Alfred Bester short story "**Adam and No Eve"**. The astronauts new space-drive uses a substance that catalyzes nuclear reaction, and some gets out the exhaust and sears the surface entirely. The astronaut is the only survivor and that's it...or is it? [Answer] # [Sterilization](https://en.wikipedia.org/wiki/Ultra-high-temperature_processing) by boiling the Earth then cooling it down. The galaxy headquarters have detected some biological activity (us) in one of their 100 billion planets, and a bored operator applies the standard procedure (namely [UHT sterilization](https://en.wikipedia.org/wiki/Ultra-high-temperature_processing)): 1. Point a high-energy laser at the planet 2. Power the laser until the planet boils 3. Let it boil for 2 seconds 4. Switch the laser to reverse mode, and cool the planet down to its original temperatures (6000°C core and 10°C crust in this case). This is done to avoid changing the planet's astronomical properties, as that could result in course modification and eventually collisions. Fortunately for the astronauts, the operator was tired and only let the Earth boil for 1 second. As a consequence low orbit is not affected. The Earth has changed a lot, in particular the compositions of the crust and atmosphere have changed significantly, but with some luck it could still be livable (it all depends on the specifics of the boiling method, which is up to you). The soon-to-starve astronauts now have 7 months to kickstart biological activity on this planet, hoping it will produce something edible and put some oxygen in the atmosphere. Good thing they have so many plants with them intended for experiments. [Answer] I don't see this answer anywhere, so I'm gonna float it by you. ## It happens to the ISS I don't know what 'it' is, maybe just a boring old wormhole, but basically the ISS gets instantly pushed somewhere or somewhen where the planet below them doesn't have people on it. I don't want to use details here, the possibilities are endless. The past, the future, alt-Earths, other nearby planets; It fixes the fixed-food problem the astronauts onboard face while still achieving the objective. ]

[Question] [ This is partly a Skyrim-inspired question, but also relevant to a story I'm trying to flesh out. In this world, magic and necromancy are perhaps not commonplace, but certainly not unheard of. Walking dead such as zombies, wights, and skeletons are reasonably common - if you leave a corpse to stew long enough, sooner or later it will become possessed by stray necromantic energy and then rise again as a mindless zombie. The people of the world don't understand why this happens, yet they know that it happens. Presumably their forefathers knew the same. These risen zombies are slow and shambling; they're not especially dangerous, yet they're still a threat in mobs. Also, there's always a risk of more dangerous variants of risen. Any corpse is effectively a ticking time bomb as to when it might return. The question is: why would society in this world continue to take that risk? Why bury and entomb their dead at all, when they know there's a chance they might dig themselves back up? Surely a much safer way would be simply to burn all their dead, or even hack the deceased bodies apart if burning is too difficult. Bury the corpses in pieces, even, so that any zombie then becomes a useless pile of limbs. And yet, these people continue to preserve whole bodies in graves and tombs, despite being aware of the risk posed. What would motivate them to build vast catacombs of dead, similar (but not restricted to) the ones found in Skyrim? (Note: 'to make it exciting for future adventurers' is not a valid answer.) [Answer] **The alternatives are worse** Burning the corpse brings back the dead as a incorporeal wraith (that is also pissed that you desecrated the body.) Dismemberment causes something similar, except the various body parts fuses and animates with surrounding objects creating a terrifying abomination. Etc. The least dangerous route is to respectfully entomb the dead, undisturbed as possible, somewhere that they aren't likely to cause trouble. (This is a bit of an "out there" solution, but it's a interesting problem and I wanted to avoid the obvious "religion" solution since religions will almost certainly adapt to *prohibit* whole burials... unless the alternatives are worse.) [Answer] > > Why bury and entomb their dead at all, when they know there's a chance they might dig themselves back up? > > > You already gave the answer in your premise: > > if you leave a corpse to stew long enough, sooner or later it will become possessed by stray necromantic energy and then rise again as a mindless zombie. > > > You *don't* leave the corpse around but perform the proper burial ceremonies and it stays dead. At least that's what the common belief would be. How do I know this? Because that's a large part of the reason *we* in the real world have burial practices and ceremonies. The old beliefs are roughly to appease the spirit and prevent the spirit or body from causing trouble. Yes, *we* don't have undead in the real world but our forefathers believed in them. While that doesn't make the undead real, it makes the *practice* grounded in reality. Sort of common burial ceremonies that are seen around the world, even in different cultures include: * washing and/or treating the body in order to purify it * enclosing the body in something to prevent it being disturbed, so it stays there. + in Christian belief, the body is buried in a cemetery where the ground has been consecrated, which (among other properties) helps the body stay there. * honouring the soul of the dead in some fashion, to make sure it's appeased * burial grounds often feature an iron fence. Not to keep things *out* but more to keep them *in*, as iron is usually ascribed properties to do with preventing supernatural access. So, we already practice preventative burial. How did they know it worked? Good old [confirmation bias](https://en.wikipedia.org/wiki/Confirmation_bias) - "We did all the correct rituals for aunt Alice and she was fine. But we had problems after uncle Bob died. We must have messed up somewhere - why else would some bad luck befall us?" If people in your world don't know better, I don't see a reason for them not to do the same - practice burial rites and hope that staves off necromancy. Sometimes it would (seem to) work with aunt Alice, other times it wouldn't - somebody didn't honour uncle Bob correctly. Must be that, right? It's important to note that while in the real world funeral rites and ceremonies about the dead don't really help the dead with anything, they *do* have a very big positive influence on the living. In many respects, it's important for the living to feel better after loss, hence cultural ceremonies do tend to address our own needs and sometimes use the dead as an excuse to do that. It can get complex quickly but to keep it somewhat simple grieving the lost can be difficult. It's important but *moving on* is also important. Helping the dead helps *us* in the end. Perhaps it wasn't uncle Bob who visited us...it was our own loss and internal pain that we projected onto the world in order to make sense of it and try to deal with. This is a very important aspect as it plays a big part in how funeral ceremonies are constructed. I really can't do the subject justice, since there are so many different practices around the world and address so many different types of support for the living. Still, just some examples include the fact that mourning and honouring the dead tends to be a group activity to lend aid to people feeling loss. Feasts and other celebrations to do with the dead tend to remind *us* that life still goes on and it's good. Again, many cultures have many variations that will address many aspects of these and more. [Answer] **The undead that come back can still earn glory for their clan.** Protecting the riches of their clan is a prestigious position that can earn glory and honor beyond the grave. If you sneak in the front door, you are greeted with the hordes of zombies entombed there. They retain some remembrance of the members of their clan and will ignore them. would-be-thieves however have to contend with the undead. (Besides, everyone who is part of the clan knows about all the back entrances straight to the vault that skips the undead) [Answer] ## Hordes of zombies are easier to deal with than lone liches There's a certain power threshold that the Necromantic Energy must reach before it is able to raise a corpse\*. After that, it becomes a linear increase in power as the Undead accumulates more energy. It is thus preferable to spread this energy out amongst as many bodies as possible so that you have a mob of weak shamblers (which any respectable town guard can handle), rather than a single, very powerful, highly intelligent undead that you need to contract some very expensive heroes to deal with. Further more people have done research into the source of this necromantic energy, and how to best reduce its affects. Placing graveyards in naturally safe areas and then placing anti-necromantic barriers (be they of magical, holy or natural) around them. Thanks to surface area to volume ratios, large graveyards are more efficient. \*If you feel this is too gimmicky, then think about it this way: A tiny amount of energy might make a corpse twitch a bit. A bit more, and it's able to thrash its limbs but without much coordination, like the average human newborn. With a bit more energy, it is now finally able to crawl and can be considered an actual threat. Assuming it's able to get out of its coffin anyway. [Answer] Perhaps they don't think it's that big a problem. As opposed to Skyrim, in modern day society people don't go grave robbing as often as you expect. When a tomb is full and gets sealed/abandoned, from what you describe it will take quite a while for the zombies to manifest. If tombs are well built, it won't be easy for them to get out. Depending on how motivated your zombies are to bother anyone (in Skyrim they just linger more or less), they might just stay there and nobody will find out for hundreds of years. By which time the zombies will have rotted away, life or no life. Same with graves, if they are dug deep enough, zombies won't be able to easily get out (TV lies to you), so they might just lay in their graves "Alive" not doing anything. As for the rest of the reasons, the same things as today apply, mostly religion and tradition. [Answer] # Divine resurrection They might become zombies, but that's a new problem. What's more important is that once in a while the gods wander round and resurrect the dead (at least they used to). So if your dearly departed was still healthy (apart from that sword wound) you want him otherwise intact for the gods to be able to bring him back. If you've burned the body that can't happen and you're accepting the loss is permanent. Anyway, the tombs are sealed, they can't get out... can they?... (Also you can't corpse run back from the graveyard if you've been cremated) [Answer] The zombies are territorial, and grumpy wakers. If you observe the proper rituals, burn the sacred herbs, and tread carefully, the dead will stay asleep, and you can pass unharmed. But go in hot, shooting fireballs all willy nilly, or clanking around in a suit of armor, and they will get up and try to snooze *you*. Once the disturbance has been dealt with, the undead yawn, go back to their sarcophagi, and go back to sleep. And soon enough there's one more sleeper in the tomb. If it's wholly possible to appease the dead via rituals and behavior, it suddenly becomes a nice prospect to be able to go see old ma or pa every now and then, just slumbering away in the catacomb. Definitely preferable to the hassle of building funeral pyres or chopping up dead family members. [Answer] You could just look to old Egyptian mummies for why. Religion dictates the body, and anything they are buried with comes with them in the afterlife. In that case, it's rather silly to burn someones body, since they will now not have an afterlife at all. This would probably be an even more common belief, when the dead sometimes comes back and starts killing people (after all, they must have unfinished business, suffered a wrongdoing etc.) So catacombs with coffins made so the dead can't get out, and there's no problem... most of the time. [Answer] Per the Elder Scrolls lore, Skyrim Nords travel to Sovngarde (home of the gods) after death. The noblest of their warrirors are granted entry to the Hall of Valor, an analogue for the viking 'Valhalla.' So, you can simply explain away the lack of cremation by claiming that if you burn the dead, their spirit is not eligible for entry into the Hall of Valor. I could find no reference in existing lore that supports or contradicts this claim, but many earth cultures had specific beliefs regarding treatment of a corpse and the effects it would have on their prospects in the afterlife - so this seems like a thematically appropriate assertion. [Answer] **Burying a body is the easiest and cheapest way to get rid of it, and it's usually enough.** I don't know if you've ever had to get rid of a body, but it's not easy. Alternative methods to burying and their disadvantages: * Burning: Humans are mostly water and to burn a freshly-dead human till nothing is left (not even bones) takes *a lot* of fire. Your average campfire just isn't going to cut it. To completely burn the body to ash, you need lots of fuel, a space big enough to burn it in, and enough time to do so. For a peasant farming family, gathering enough wood to burn a body could get quite expensive and city-folk would need large spaces to burn their dead or organize large communal corpse-burnings outside of city limits or in large squares. * Cremation: Similar to fire, except more expensive. Building an oven that gets hot enough to burn people to ash, fueling it, and operating it isn't something that small farming villages or poor city-dwellers can afford. * Acid: Well, it is fantasy so maybe pits of acid are just available but enough corpses will eventually dilute the acid to the point that you need new acid. Probably even more expensive than burning or cremation. * Dismemberment: A simple way to prevent zombies would be able to chop the corpses to bits before they're buried however this is quite gruesome. In the "generic low-fantasy setting", most peasants bury their own dead and having to take the axe to uncle Smith's limbs would be hard on an already grieving family. For most people, a simple burial is enough. Unskilled labor (digging a hole) is something that anyone can do and costs basically nothing. Also, even if the body does become a zombie, that doesn't mean it automatically starts walking about. If the hole is deep enough, it's basically impossible for a zombie to dig itself out, especially since it's pretty stupid. [Answer] # To protect the tombs Well, ask a Skyrim question, get a Skyrim answer. The dead are literally *expected* to get back up again, and protect the tombs from those who would loot and desecrate them. Note that they mostly stay inside the tombs. They don't go outside and ravage the countryside (much). When you go into those tombs seeking treasure and glory, *you're* the invader, the draugr were put there specifically to protect their family riches from disrespectful adventurers like yourself. Have some respect for the dead, they're only doing their jobs, and here you come along and try to rob the place... [Answer] If you bury the dead in the ground and they come back to life not as loving friends and relatives but as blood thirsty dangerous zombies, how do they get out of the ground? Apparently the zombies can break out of their coffins (if any) and dig their way up out of the Earth, indicating that they might be significantly stronger than humans as well as not needing to breathe. If you bury the dead in tombs and they come back to life not as loving friends and relatives but as blood thirsty dangerous zombies, how do they get out of their tombs? Wouldn't the lid of a stone tomb be very heavy? It is possible that even a zombie much stronger than a human would be unable to lift the stone lid of a tomb. If dead people coming back to life was not a blessing but a curse because they attacked living people, living people would kept trying different methods to contain those dangerous zombies until they found methods that worked. So they would try wrapping bodies in burial cloths and tying them up. And maybe making burial cloths out of very heavy and strong canvas and sewing it up with strong thread. And maybe they would try wrapping up the dead in strong chains and locking the chains together with padlocks. And maybe they would try burying the dead in strong wooden coffins and nailing and screwing the lids down tightly. And maybe they would try burying the dead in strong metal coffins and welding the lids tight to the rest of the coffins. And maybe they would try burying the dead in coffins and wrapping strong chains around the coffins and locking the chains with locks. And maybe they would try burying the dead in stone sarcophagi with slots underneath to wrap strong metal chains around, hoping the undead would be kept inside by the sheer weight of the stone lid, and by the strength of the mortar used to attach the lid to the sarcophagi, and by the strength of the locks and chains around the sarcophagi. And maybe they would try burying the dead in stone mausoleums and shutting and locking the windows and doors and then closing up the window and door frames with stones and mortar. Or maybe they would try putting a dead person in a series of strong coffins one inside the other inside a stone sarcophagus inside a stone mausoleum, all shut,locked and bricked up with stones and mortar. So it seems likely that the living would experiment with ways to keep the dead shut up in their tombs forever if there was a problem with attacks by the living dead. [Answer] The most logical reason would be (religious) traditions, for example of they believe that burning the deceased would give themselves or the deceased a one way ticket to hell(or non-existence) they would be more inclined to not burn them (Even if they know the risk). Another would be to wanting them to come back as a form of security. In Skyrim, the only things protecting these often sacred places are the undead wandering around. Lastly it could be a new phenomena, that it only recently started happening and so they started burning the corpses but the ones buried in the 100's of years before are still buried. [Answer] # To allow low level players to level up In the web comic [Order of the Stick](https://www.giantitp.com), the gods created goblinkind in order to allow for low-level clerics to gain XP without exposing themselves to much danger. It may be that in your world, the gods imbue corpses with life so that young heroes can have some practice before moving on to more dangerous things like dragons, basilisks and capitalism. [Answer] Properly maintained and controlled zombies are an important economic resource. The local undertaker is a friendly necromancer, and for a modest fee he takes all the zombies out every year to help with the harvest. Evil necromancers are seen as corrupt practitioners of an otherwise respectable profession. People don't fear the existence of zombies, they only fear that their zombies will be stolen by an unlicensed necromancer or allowed to roam free without a necromancer keeping them under control. They really hate liches, though. When the dead control the dead, who harvests grain for the living? [Answer] Because Zombies are relatively easy for humans to deal with, and "oglops" (or whatever) are not. Oglops can sense zombies turning, as they are prey to them, and so avoid anywhere near catacombs/graveyards. Oglops devastate crops, spread diseases, contaminate water wells, and multiply like rabbits. They're hard to catch and impossible to contain, so the best thing to do for cities to work is to just keep a catacomb nearby with a few guards on watch to deal with any zombies that arise. [Answer] ## Speak with the dead Most towns and villages have at least one Shaman who can cast speak with dead. So often we wish we could ask our passed on loved ones important questions like, "Where did you bury the treasure?", "What's your recipe for Lambas Bread, I just can't get it to hold together?", "Which of us did you love more?" or whatever ever super important, entirely not frivolous question you might have. If you bury them in dirt you'd have to dig them up. If you destroy them, well, there's nothing left to ask questions of. And folks usually get grumpy about decapitation/dismemberment and become recalcitrant about answering postmortem questions if their remains have been mistreated or aren't in a sufficiently posh resting place. So you make tombs, that can be locked from the outside. Need to ask great-grampa how to make that special kind of steel at the forge? No problem. Also, rest assured, there's almost no chance at all that forcing the dead back into their bodies to ask trivial questions is in ANY way related to them reanimating as shambling corpses. Nope none at all. Just keep messing with forces you don't understand. It'll be fine. [Answer] If only some dead turn into zombies, then perhaps the culture is opposed to burning their dead for the reason that some cultures oppose condoms while still knowing that condoms can prevent unwanted pregnancy and disease. Maybe they see zombiefication as something that happens only to criminals or bad people - not something likely to happen to members of their own family. [Answer] Occasionally, instead of resurrecting as a mindless zombie, the departed resurrect as *themselves*. Fully functional, alive, normal, no *Pet Sematary* type effects; just *themselves*. This means that the unpleasant aspects of zombies rising are something the society is willing to deal with, in order to allow the "lottery winners" (favored by the gods, or what have you) to rise again. [Answer] It's a recent development. All crypts are less than a few hundred years old because the fad of whole burial came about then because a noble had reasons™ to build a crypt. Then after a century of being lying in a cave the bones started getting animated and the crypts were ordered to be sealed and they reverted to the previous burial method. Prior to that and again afterwards the accepted burial method didn't create zombies. This can also explain why most of the traps still work. The crypts just aren't that old yet. [Answer] ## They didn't know The accumulation of necromantic energy is a fairly recent phenomenon, going back only a hundred years or so. Before that it was perfectly safe to bury your dead, so people did. [Answer] They're not catacombs, they're prisons for undead. [Answer] They believe god called them back for a second life? Maybe they believe they have two lives one for themselves and one of the gods that could be a positive or a negative life depending on how they structured and worshiped (or didn't) in their mortal life. If there is a timeframe for their revival as 90 yrs or longer then humans can dream up whatever they desire their idea is to strive to be raised up by the good god if they are a good person to do just things they know they have no input god commands and they obey without fail. Other cultures could divide the body up because they don't have such notions of a self life & a godly life they just see zombies and go, "No thanks." Other cultures could strand them on cliff faces so when they arise they fall into the ocean and get locked into under current pools that keep them imprisoned into the depths. If it's not godly calling that your culture is keen on maybe it's ancestor worship during the lives of the remaining family members one or several members keep the corpse feeding it, speaking to it, and maybe even dressing it they do this to not inter it until the last family member dies or the family is ready to accpt the transformation process (but this is considering you have one corpse for a duration of time) Treating the dead this way prolongs the inevitable transformation they believe if care was sufficient they will rise with less harm for humans or none at all. If the care was poor or nonexistent they will arise aggressive to hyper aggressive. They believe the family member is simply resting off their mortal life and will reawaken for their temper phase basically the person is mad their earthly life ended so they go through a rage before dying and accepting it in battle or from time. The family know the chances for refinding the arisen family member for second burial is low so treating them well for a duration then burying them is meant to be that mortal grieving and acceptance for them to move on in their after life as they know no matter how calm they are upon return they just simply aren't the family member who died. Humans may feel this is all godly or out of their control but in reality it could be all humans have a symbiotic creature in them that feeds off their remains with exposure to X conditions underground so select caves or marshes or what have you actually restore less hostile zombies while others are highly aggressive allowing you to cover several zombie types in media so you have shibito, classic zombie, hyper zombie, tame/pet zombie, Skyrim war zombie, ect but do you have smart zombie? Like I-Zombie? You can also have conditions where the rising never occurs because the area like a marsh bog or whatnot seals the reason why the corpse returns anyhow this rare area may hold the key but once you raise the dead for study they will swiftly transform maybe into hyper zombies having been suppressed from turning prior. ]

[Question] [ Is it possible for a planet in our part of the galaxy to have a night without stars? I'm looking for some kind of natural phenomena that would hide the stars, but allow the sun to rise and fall as normal. The atmosphere and day/night cycles should be unaffected. It is the basis for a society that develops into the modern age without an interest in outer space, and is located relative near to our solar system. So that travelers from Earth make first contact to a modern society that had no idea there was an outer space. This can be a solar system with only one planet. [Answer] Dust cloud. The star may be residing in a dust cloud with no other stars nearby. This interstellar dust will create a faint nighttime glow, and can be thick enough that no other star's light can be visible on the planet. [Answer] Perhaps their planet is on the inside of a giant [Dyson sphere](https://en.wikipedia.org/wiki/Dyson_sphere) that was created by an ancient civilization. This would be a vast solid shell that surrounds their entire solar system, the inside of which is covered with solar panels in order to collect as near as possible to 100% of the energy output of their sun. Naturally, this would block their view of the rest of the galaxy as well. As for why the ancient civilization who built it left this one planet on the inside, that's up to you to decide. Maybe they saw that it had some life forms that might potentially develop intelligence some day and didn't want to just kill them off, so they left them where they were, while dismantling all the *rest* of the planets in the system to build the sphere? [Answer] One possibility is for the surface of the planet to be covered in highly luminous matter. Perhaps all the surface is an interconnected network of bioluminescent life. There is no moon (assumed because you make no mention) and the high levels of light pollution at night will blot the stars out. You could combine with a naturally hazy atmosphere and cloud cover to a) further blot the stars and b) reflect all that light pollution back to the surface, further brightening it at night. Normal urban terrestrial light pollution (before and during the great 2003 Northeast Blackout) to give you an idea: [](https://i.stack.imgur.com/SwZY8.jpg) [Answer] **It is never night.** [](https://i.stack.imgur.com/IwP1s.png) <https://www.tripsavvy.com/midnight-sun-in-scandinavia-1626397> Your people live on the north pole of a tidally locked planet. Like the countries near the north pole on our planet, in summer the sun never sets. It is always summer for your people. Why do they only live near the pole? Maybe it is hot farther south. Maybe there are scratchy monsters. Maybe there is no land to live on. Maybe they are afraid of the dark. [Answer] The laziest answer is to just wait a while. If you wait an incomprehensibly-long while, eventually the expansion of the universe will move all currently near-by light generating bodies outside of our visual distance. In other words, civilizations in the far-future may never realize that anything other than their own sun exists, because nothing else is close enough to interact with anymore. This video has a nice overview: <https://www.youtube.com/watch?v=Qg4vb-KH5F4> [Answer] there are many ways. especially if it's just you don't see the stars. there could be a constant storm like on Jupiter and in 'All Summer In a Day' by Ray Bradbury. Venus has an atmosphere made up mainly of carbon dioxide, and thick clouds of sulfuric acid completely cover the planet. basically, clouds covering the entire planet would do the trick. 'light pollution' would also make it so the stars can't be seen because the ground is so bright. Night Sky in Las Vegas Which is always full of light especially at night [](https://i.stack.imgur.com/yS4A9.png) vs the Idaho dark sky preserve [](https://i.stack.imgur.com/6tlLI.png) [Answer] > > Is it possible for a planet in our part of the galaxy to have a night without stars? > > > It depends on what you mean by "our part" of the galaxy. If you point yourself in the direction of Sagittarius and travel a mere 2600 light years you will find yourself smack in the middle of the Great Rift, which is the dark patch you see covering the Milky Way. <https://earthsky.org/clusters-nebulae-galaxies/the-great-rift-in-the-milky-way> This is an area where new stars are formed, but obviously the dust is thick enough that we cannot see through it in the visible spectrum. It seems plausible that there could be star systems in that large area where the dust is thick enough that no other star is visible. Note that the "thick" dust is by Earth surface standards extremely dilute and would be considered a high-quality vacuum. It's only the fact that there are light years of the stuff that make it hard to see through. > > It is the basis for a society that develops into the modern age without an interest in outer space. > > > You might wish to research how the "space cloud" and "planet that doesn't know about space" tropes have been done before. <https://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceClouds> and <https://hitchhikers.fandom.com/wiki/Krikkit> may be useful. [Answer] The sun takes up about half a degree in Earth's sky. Stars are less than one ten thousandths of that. If atmospheric blurring were to blur a star one hundredth of a degree, their light would be spread over an area hundreds of times larger, making them practically invisible, while the effect on the sun will be minuscule. [Answer] HG Wells had a valley populated by blind people. They had no concept of daylight, so slept in the warmth(day) and worked in the cold(night) Because the 'hero' couldn't see at night, he was less capable than any of them. I see that someone commented about this answer not addressing the question - sorry, I'm new here, and I am realising that answers need considerable amplification, so let me add some more. the question says *I'm looking for some kind of natural phenomena that would hide the stars, but allow the sun to rise and fall as normal. The atmosphere and day/night cycles should be unaffected. It is the basis for a society that develops into the modern age without an interest in outer space,* So - a natural phenomenon would be blindness - the absence of sight. As can be demonstrated, or researched endlessly, blind people can carry out normal life - more so where adaptations are made, such as alarms to indicate when fluid in a cup, say, has reached within a given distance of the top. Or lets move further to travel. A society evolved as blind would place indicators at the edges of pathways, and tactile markers to indicate direction. If you can feel it, they can deal with it. This includes edge tools, and the capacity to produce more advanced mechanisms and more advanced means of travel such as boats. Now - specifically, if you haven't seen the stars, then you have no notion of there being 'anything' out there. I referenced HG Wells story because he does such a good job of describing the adaptations the inhabitants of this world adopt, whilst leaving them as a potentially advanced society - as may be needed by a world builder. I submit that this answer fits both parts of the question - it explains and allows sunrise and fall, atmosphere and daylight. It also provides the means for a 'modern age' society' to arise and function. It may not be what the OP (or commentator) expected, but it does fit the question. <http://www.online-literature.com/wellshg/3/> [Answer] It's part of a rogue solar system ejected from any galaxy, somewhere in the middle of a large intergalactic void. No stars would be visible until the inhabitants developed sufficiently powerful telescopes to be able to see the faint light of distant galaxies. [Answer] The people have eyes that only see sharp nearby. Everything is blurry to them on (very) long distance. It would not be too much of a disadvantage in normal life, but it would prevent them from seeing stars. Only after they develop reliable lenses, they would discover that stars exist. [Answer] The sun is a star, but I know what you mean. Here are some other options: * Multiple suns (such as Asimov's "Nightfall") * One sun, and many moons * Large amounts of very white (or reflective) dust, which reflects sunlight around the atmosphere. * Underground or underwater societies. * Regular volcanic eruptions causing volcanic ash in the atmosphere (or anything else in the atmosphere) * Monsters that come out at sunset * taboo/superstition/religion * Your planet might be near a black hole, causing gravitational lensing, an accretion disk, unusually high speed orbits, and jets coming from the poles. [Answer] I don't know if that counts or not as 'affecting/messing with atmosphere', but I've decided to reply anyway. **There's a layer of gas in the atmosphere that diffuses the light.** Light is still capable of passing, but it is randomly diffused before getting into the surface of the planet. The day would still be very well illuminated, but they wouldn't see the sun itself: they wouldn't see a bright ball up in the sky as the source of such illumination. As for the night, no stars, and darkness. If there's a moon, the same thing from the day will happen: one won't be able to see moon itself, and a far lower intensity light reaches the surface, faintly illuminating the surface. [Answer] There could be intelligent life living under the ice on [Enceladus](https://en.wikipedia.org/wiki/Enceladus) right now. The thick ice would prevent them seeing stars. Similarly, the habitable zone of your planet might be entirely underground. [Answer] Most of the answers so far seem to be ignoring the requirements that there be sunset or that the atmosphere behave differently. A large dust cloud surrounding the solar system seems like the most reasonable way to achieve what you want since it doesn't directly affect anything within it. Its origin and how long it will persist are for you to work out. But whatever solution you decide on, it sounds like the driving force in the story will be the reaction of those people to this new revelation. If so, make sure you come up with something new and don't appear to be copying how society reacted in Asimov's "Nightfall" (which used multiple suns to make total darkness *almost* impossible). [Answer] # First idea: Their visual organs use a different method of "seeing". You could make it so that your planet's inhabitants can't see, or some variant thereof. I don't mean to say that the people are blind, but rather they have other organs that can "see" that would serve a similar purpose, but might seem magical to us. For example, if they were to inspect a sheet of paper, they might be able to easily detect tiny folds and creases in the paper, while the image on the sheet would be invisible to them. To them, a pure-white rabbit on pure-white snow stands out clearly, whereas the pictures and text of a highway billboard sign are hidden to them, precisely because there is no "three-dimensional-ness" to distinguish the images from the board itself. To them, the sky might look perfectly flat (or maybe even perfectly dome-shaped). As for their sun, they can either perceive it using another sense, or maybe its special case of being abnormally huge (compared to anything else they are familiar with) is enough to make them perceive it. (If you can see those 3-D stereo images, you might understand what I'm getting at. When you succeed in seeing those images, you'll notice that you're perceiving three-dimensional shapes instead of colors. A starry sky wouldn't work too well in those 3-D stereo images, but a sun in the middle of the sky might.) This could be similar to sonar; for example, a dolphin could detect a sheet of paper in the water no matter how dark or murky its surroundings -- however, it wouldn't be able to use sonar to perceive the picture drawn on the sheet of paper. # Second idea: Their visual organs perceive different wavelengths of light than ours do. The inhabitants could have eyes (or similar organs), but see a different spectrum of light than us. And it just so happens that 99.9% of stars in the universe display light in the parts of the spectrum they can't see. Their sun, however, is one of those 0.1% of stars that they can see. You could even say that they evolved/adapted the ability to see their sun's light precisely because it comes from their own sun. (So why have a need to see other light?) [Answer] You could toy around with the idea that your society's planet could be in the L1 Lagrangian Point of a very large, non-reflective planet. As the society's planet orbits on its axis and brings the society to their own planet's dark side, they would see only the large dark planet in their sky, which would appear to them only as pitch black. However, there is a significant window of time (particularly around sunrise and sunset) where they could still see the dark of night (including the stars) which is not covered by the large dark planet. If you're daring, you could make the dark planet a very non-dense, stretched out object that acts as a sort of visual shield around the dark side of the society's planet. Sure, having such a large object in a non-spherical shape seems like a stretch, but maybe there are some special cases in this universe where that could happen. (After all, we already have Saturn, whose rings are quite visibly wider than Jupiter itself, but definitely not spherical.) Maybe the large, un-dense planet could have a large set of (seemingly solid) pitch-black rings. Or maybe it could have some other sort of shape anomaly more common than planetary rings, but that we're not familiar with simply because no planet in our own solar system happens to have it. To put it another way, if Saturn didn't exist, we wouldn't have all those pretty artistic night-sky renderings with ringed planets (despite the fact that ringed planets do exist outside our solar system). So what other pretty astronomical sights are we not including in our artistic night-sky renderings, simply because they don't exist in our solar system, making us not aware of them? In other words, just because something is planet-sized, doesn't necessarily mean it has to be shaped like a sphere. Some ancient civilizations (here on Earth) thought that our sky was literally a dome. So maybe your society's planet could be in the L1 Lagrangian point of a non-light-reflecting partial dome. [Answer] Maybe they have vast swarms of firefly-like creatures that come out at night? They figure that they already know what stars are, since they are so obviously these creatures, that they never bothered to question it. Perhaps the planet has some killer aurora borealis or something that drowns out the stars. I personally liked the idea from *The Three Body Problem* which made it so that the intelligent species lived in a trinary system and would go through periods of heat so intense that all water would evaporate, and periods of cold such that the atmosphere would freeze. It would be really hard to get a civilization going when you have a near extinction event every millennia or so. I also like the idea from *Ringworld* where these people lived on a failed Dyson Ring, and because the ring didn't have any way to mine metals, these stone-age folks couldn't get back up the technology ladder; they were stuck using stone and wood forever. [Answer] If you are on an isolated star in the middle of the Boötes Void ([https://en.wikipedia.org/wiki/Boötes\_void](https://en.wikipedia.org/wiki/Bo%C3%B6tes_void)) you would not see a single star or galaxy with the naked eye. BTW - have you ever read Iain M. Banks' Against A Dark Background? [Answer] Since many good physical explanations were given, let me provide some lateral thinking sort of answer. The reason there are no stars is that they live in a giant simulated universe and there's not enough processing power and memory to simulate a full universe, just that solar system with just that one planet. So the sky is dark at night. The humans which are visiting are in fact those running the simulator. [Answer] I would suggest that their solar system is passing through a relatively very dense dust cloud in interstellar space, as others have suggested. Their solar system would have been passing through it for hundreds of thousands or millions of years, long enough that the intelligent beings living there have no possible way to remember that their pre-intelligent ancestors ever saw stars in the sky. The gravity of their star system has been pulling in the interstellar dust so that there is a clear cylinder of space pointing out of the dust cloud back the way they came. So that direction should point out toward intergalactic space with only a few stars in their galaxy and no globular star clusters, other galaxies, or intergalactic stars in the light of sight. The in falling dust doesn't fall all the way to the star, however. At at certain distance range light from the star and particles in the stellar wind from the star hit most of the in falling particles and bounce them back out a bit before they fall back and are bounced out again. Thus there is a relatively dense shell of dust particles at the outer edge of the star system, dense enough to block all light that comes in through the clear cylinder of space and hide the relatively few stars that would have been visible through it. The inhabited planet could be the only planet in its star system. But maybe there used to be two large planetoids or asteroids orbiting outside the orbit of the inhabited planet, worlds that collided and shattered into dust. Thus there could be an inner dust ring around the star outside the orbit of the planet, a dust ring that might also help to block out the light from the stars. The atmosphere of the planet should be similar enough to Earth's for the natives, and maybe visiting earthlings, to breath without problems. But the atmosphere doesn't have to be identical to Earth's. The atmosphere could be naturally foggier, or dustier, or something, than Earth's, thus making it slightly less transparent. And the intelligent natives might be greatly polluting their atmosphere and making it less transparent. And if the planet has a slightly smaller surface gravity than Earth's, and a slightly higher atmospheric pressure at the surface than Earth's, the atmosphere will extend a bit higher than Earth's. Thus there were be more atmosphere for the light from the stars to pass through and be dimmed than on Earth. It is possible that there are bioluminescent organisms on land or sea or perhaps in the air that emit a faint glow in most parts of that world. And if the atmosphere is foggier or cloudier at night that glow will be reflected down to the surface, further hiding the stars. And of course in the cities of the intelligent natives and their suburbs artificial lighting may increase the light pollution as it does on Earth, hiding the stars even more. The intelligent natives may depend mainly on echolocation and less on their vision, which might not be as good as human vision. And perhaps they have evolved a slightly more close range and less long range visual focus, for fine handiwork, making it slightly harder for them to see the stars. Aquatic aliens, such as intelligent cephalopods or cetaceans, might have good vision in water but not so good in air and might not be able to see the stars. And some combination of several of the above factors may prevent the aliens from seeing the stars, whether humans with possibly superior vision can see the stars from the alien planet or the stars are equally hidden from humans. [Answer] Some examples from our own solar system: This society could very well come from our own solar system, our neighboring planets. If this society were to come from Venus, then the dense atmosphere would hide the night sky quite well. Titan also has a very thick atmosphere. And on Titan, I expect that even if the atmosphere had a transparency similar to Earth's, the reflected light from the numerous moons, as well as Jupiter would hide any starlight. The society would, however, know of things beyond their sky, being able to see the Jupiter as well as all the other moons... [Answer] The planet [Saraksh](https://en.wikipedia.org/wiki/Saraksh) described by Arkady and Boris Strugatsky in their book [Prisoners of Power](https://en.wikipedia.org/wiki/Prisoners_of_Power) is close to what you are looking for. > > Saraksh is notable for its monstrous refraction in the atmosphere. From the surface, it looks like the horizon is above the observer which makes the inhabitants of the planet think that they actually live inside a hollow cave in an endless piece of rock rather than on a round planet floating in space. The phenomenon of night and day change is explained by periodic changes in the clouds gathered in the middle of the "cave". > > > You have day/night cycle and despite not actually seeing the sun, you can possibly track its position by looking at the illuminated part of the cloudy sky. [Answer] The simplest way I can think of is to have a thicker atmosphere, and a warmer average temperature. The two combine to make a constant haze that in effect is like "cloudy bright" (photo term...) The sun is a bright spot in the sky. There are shadows, but they are diffuse. The effect would be much like a smoggy night in L.A. during the 80's, but without the stink. As a W.A.G. increasing the atmospheric pressure by about 10 psi, and the temperature by abouat 10 C would be sufficient. --- A second possibility is to put them in a red dwarf system. The planet has to orbit close enough to the dim red star that it's tidally locked. This makes it always day. There is constant high altitude wind at high elevation from the center of the daylight side to the twilight zone. There is a constant surface wind from the dark side to the sunny side. The twilight zone should be constant storm from the cold darkside air running under the warm brightside air. Indeed, you may need to be close to the sub-stellar point to see any sky at all. Then you are looking at high noon. I suspect that neither of these works as they never see a dark empty night sky. Sidelight: Look at Asimov's novelette, "Nightfall" <http://www.asimovreviews.net/Books/Book457.html> ]

[Question] [ I have a tribal merfolk society, living on and near a volcanic island, that is also inhabited by humans. The problem that I can't seem to figure out is: how would they dispose of their dead? Wouldn't sinking the bodies in waters around the island have negative effects on local marine life? The humans dispose of their dead by burning them in the volcano. So I didn't want the merfolk to do the same. Any thoughts? [Answer] # Blue Hole [](https://en.wikipedia.org/wiki/Blue_hole#/media/File%3AGreat_Blue_Hole.jpg) In the waters near your island, there is a place where no merfolk dares swim. It is an underwater sinkhole. Legend says that at the bottom dwells the god of death. Any merfolk who attempts to swim down to the bottom finds that, less than halfway down, their gills can no longer bring them enough air to breathe: they either drown, or frantically swim upwards to the light, feeling blessed to have escaped the death god's clutches. ([Blue Holes](https://en.wikipedia.org/wiki/Blue_hole#/media/File%3AGreat_Blue_Hole.jpg) are anoxic zones, rich with bacteria, but deadly to other marine life). It is into this pit that the dead are cast, weighted with beautiful jewelry of coral and stone, to pass into the afterlife. [Answer] **Sky Burial** (or rather the undersea equivalent) Certain cultures in south Asia have a practice which is termed [sky burial](https://en.wikipedia.org/wiki/Sky_burial). Basically, the dead bodies are taken to a remote location (normally high on mountains) and left for scavengers. In contrast to Western culture where scavengers are viewed as evil and unclean, in cultures with sky burial the particular scavengers which act on the corpses (typically particular vulture species) are seen as being endowed with a certain sacredness. For your merfolk culture, you could have something similar. There's a large number of species in the ocean which specialize as decomposers, cleaners and scavengers. The merfolk could have certain regions in a reef (perhaps caves, or groves of coral) where such scavengers live. These could either be naturally occurring, or the scavengers could be collected from across the ocean and placed there. The dead body would then be lovingly placed in that area, after which the scavengers which live there would remove (eat) the body in relatively short amounts of times. [Answer] > > Wouldn't sinking the bodies in waters around the island have negative effects on local marine life? > > > Quite the contrary. While dead organisms release potentially toxic amounts of nitrites and phosphates in a closed ecosystem such as an aquarium, larger marine ecosystems actually depend on this circle of life-- like trees do for our air, algae feeds off of these poisonous byproducts to keep the water from becoming toxic. (If too much stuff dies, you end up with things like algae blooms, but nature always balances itself out. Your aquarium, not so much.) When marine life dies, it initially sinks to the sea floor. Shrimp and other bottom-feeding detritivores come along and pick it apart. As decomposition happens, the carcass accumulates pockets of gas inside itself, causing bloating and buoyancy and the apocryphal "going belly up." So you have a pretty cool pretense for something Rapture-like here. Bodies could get left on an altar in an open-air crypt or lowered into a giant mantis shrimp's lair. Once the body has fulfilled some nourishment role and been mostly consumed, it will naturally ascend to the surface/heavens, get carried off by currents as it disintegrates, and humans may find the occasional stray scale or something washing up on shore. [Answer] Why dispose of them? Life under the sea is difficult. Acquiring enough nutrients to survive is always done at great difficulty. It's not like they can plant their food like humans do. They must constantly hunt fish, scavenge or gather whatever they can, and, occasionally, trade with the humans nearby. Therefore, when one of them tragically dies, they don't get rid of the body. It's not only a great waste, it can also attract predators. So, instead, they honor their dear departed by fully consuming the body, in a ritualistic meal in which they celebrate the life of the deceased, and all the sacrifices he made for the community. The humans may be squeamish about it, but what do they know? Why, they throw their honored dead into the fire, the barbarians! [Answer] **Crypt.** [](https://i.stack.imgur.com/NG8pP.jpg) [source](https://www.google.com/search?q=giant+prehistoric+crypt&safe=active&source=lnms&tbm=isch&sa=X&ved=0ahUKEwii-_fH58TdAhVKuVMKHckPCIUQ_AUIDigB&biw=1920&bih=889#imgrc=YBHs7MoRIyVkyM:&spf=1537282496386) On the island is an ancient building which the merfolk now use as a crypt. It was not built by the humans who live there now, nor was it built by the merfolk; its builders are long gone and it is not known what manner of beings they were, why they built or what it was originally for. It may have originally been completely underwater, and was uplifted with the volcano. The humans fear it and stay away. That suits the merfolk, and the fact that it is accessable by sea suits them as well. It is much larger than the merfolk need; even though hundred of merfolk remains now line the walls there are still large unused areas and even unexplored areas - the structure extends above and below ground, and also below sea level in many places. [Answer] # Burial at land Surface dwellers (i.e. Humans) long believed in Underworlds of a sort. Inside the bowels of the Earth were a mysterious place, one potentially inhabited by gods or monsters. The dead were often associated with the Underworld, an associate that lead to widespread burial customs. For merfolk, the obvious 'other world' is the surface. Honored dead can be taken out of the life giving ocean, and placed in the surface world, with which the afterlife is traditionally associated. After all, what merperson knows about the goings on in the mountains and forests of the surface land? Bodies are prepared ritually taken onto the shore, and placed in restful positions. Sure, we humans may know that the fate of those bodies is to be devoured by scavengers, but it isn't like we go digging up our own dead to see what happened to them (at least, not very often) and even the ancients knew that a buried body was eventually worm food. Merfolk never go onto dry land, except for these burial ceremonies, so they just don't think very much about what happens to the bodies once they are deposited. [Answer] If you really want a parallel, your dead merfolk could be more rapidly decomposed by 'burying' them in deep geothermal vents. As your island is volcanic, it isn't much of a stretch to imagine a fault line/trench with geothermal activity somewhere in the general vicinity. This will at least deal with having corpses of your family floating around the general area and could give some plot lines since the humans and merfolk both observe similar reverences for their dead, in the same volcano/fault. [Answer] **Symbiotic relationship with the humans** When a Merperson dies, they are wrapped in seaweed and left on a special rock platform on the shoreline near the human habitation. The humans quickly come and remove the body, which is never seen again although sounds of feasting and rejoicing coming from the direction of the human village soon after. It is the humans way of honouring the Merfolk's dead. (Of course, what the humans are really doing is eating this convenient source of free food!) [Answer] It partly depends on the religious beliefs. Tibetans often used [sky burial](https://en.wikipedia.org/wiki/Sky_burial) as a way of disposing of bodies, their religion telling them that the dead body is a useless discarded husk, and wanting to allow the elements of the body to be reused. A similar ritual for the merfolk would be to take the dead body to a special area, saying prayers for the soul (depending on religion), and commending the body to go back to nature. The place would doubtless have plenty of fish to eat the bodies. [Answer] **Underwater Bone Graveyard** The corpse is dragged by familiars to a specific place (graveyard) where small animals or fishes quickly eat the flesh, but preserving the skeleton, that is placed with the others. [Answer] [Burial at sea](https://en.wikipedia.org/wiki/Burial_at_sea) is an actual thing in the real world. It has been practiced by humans for millenia. Most of the major religions, whose foundations date back from centuries to millenia, have their methods and rites for it. For example, from the wiki above: > > **Protestantism** > > > The Anglican Communion has detailed procedures for burial at sea. The ship has to be stopped, and the body has to be sewn in canvas, suitably weighted. Anglican (and other) chaplains of the Royal Navy bury cremated remains of ex-Naval personnel at sea. Scattering of cremated remains is discouraged, not least for practical reason. > > > In the Book of Common Prayer (1928) of the Protestant Episcopal Church in the United States (ECUSA), a member of the Anglican Communion provides a specific prayer of committal for burials at sea. > > > Countries have their own codes for it as well. Also from the wiki above: > > **United States** > > > A funeral director is not required for the burial of cremated remains at sea. However, full body burials require specific preparation to ensure the body or coffin sinks quickly, and in many states a licensed funeral director is required. The Environmental Protection Agency regulations for full body burials at sea in the United States require that the site of interment be 3 nautical miles (5.6 km; 3.5 mi) from land and at a depth of at least 600 feet (180 m). California prohibits whole body burial within its state-asserted three-mile limit... > > > Your merfolk could take a page from humans and do something similar. The seas have their own scavenging animals, so any corpse will be devoured and the nutrients will go back to the ecosystem. As long as they dispose of the bodies far enough from the island, and maybe tied to - or sacked along - some stones to weight down the corpse, the dead should not end up washing ashore. **Edit:** for anyone who thinks a burial at sea could not be effective: it would be the underwater equivalent of a [zoroastrian funeral](https://en.wikipedia.org/wiki/Tower_of_Silence). [Answer] **Coral Cemeteries** The bodies of the dead are covered in hardened clay casts, or something sufficiently sturdy to give them structure. These casts would be brought to the edge of the coral reef, where they would be placed like a memorial. Friends, family, or community could come and pay their respects to them in a ritual where they give the body back to the sea, similar to a sky burial mentioned in other answers. The cast would be adorned with coral polyps, giving the coral a head start on forming. Depending on the social structure in your story, perhaps the royal family has some responsibility to maintaining the reef, and as such are able to adorn their dead with more polyps, to mark their contribution to society, and their eagerness to give back to the coral, by providing more head starts. A few small holes could exist in the cast, which would allow water currents to pass through, bringing with it small organisms. These organisms would feed on the body inside the cast, and the coral would feed on those organisms that got swept out through the holes. In this sense, The Reef becomes their ancestors. [Answer] ## Given to the Leviathan I was going through the answers and I really liked the blue hole idea - what if you expanded on that? What if, down in the blue hole, there was some monster like a leviathan or a kraken? Maybe it's respected, even worshipped, by the merfolk, and it eats the bodies when the merfolk throw them into the blue hole - and no one goes down there because it would probably eat them, too. The creature could be a symbol of a god of the sea, and by being fed to the creature, the merfolk is reunited with the sea god. The creature might not be in a blue hole - it could be hidden in the sea floor, covered in barnacles and sand. It could swim through the open ocean. And then there's the added fun of designing a massive leviathan. Another idea: the leviathan eats the bodies, but keeps the treasure they were weighted down with - meaning it has an entire hoard. And what would happen if someone discovered that hoard? [Answer] **Fed to the Sharks** Some people have a thing called "[Sky burial](https://en.wikipedia.org/wiki/Sky_burial)" where the body is placed on a high platform, where it is eaten by carrion birds. I could envision merpeople doing something similar - taking the body to a venerated place away from the city where it's fed upon by predators. This might even serve to keep said predators away from the city. [Answer] **Actual sky burial** Using the swim bladders of large fish, they create balloons which they fill with hydrogen from underwater volcanic vents. They attach the body of their loved one to this balloon using lengths of woven kelp, then they release him into the sky to be eaten by birds. ]

[Question] [ **Me** You might call me evil but the facts are I deserve to rule all of the world, everyone & everything in it. **What I already have done** For years I have worked in the shadows (as much as you can call owning one of the largest corporations in the world as "shadows") & now have a network of 1024 fully functioning satellites orbiting the earth. You people & your governments were actually silly enough to think they are merely communication satellites when I started launching those (well there have been a few who figured out the true use of them, but they have been silenced since). The true use of the satellites is them being space nuclear launch facilities that are capable of wiping out humanity (or at least over 99.99% of it). Each satellite is equipped with the following: * 12 of the largest nukes humanity has ever seen (each equal in explosive power to the strongest nuke ever produced by a "government") * Cameras & radars of multiple wavelengths designed to detect any object launched from earth to space (assume that the network has no blind spots & covers every inch of earth) * Sensors capable of detecting the amount of pollution, temperature of earth, & other signs of global warming. * A directed optic laser based communication device between each satellite & the closest 5 other satellites. I'll go about this network in greater detail soon. **My plan** I intend on broadcasting to the world, letting them know about the satellites' true purpose & give them a list of my demands: 1. They are not to launch anything to space; any launch of any object to space detected will trigger all the nukes' immediate launch. 2. They are to stop any source of climate warming including any non 100% clean power production (see? I'm a generous ruler). 3. They are all to bow down in front of me and make me the ruler of the world. Obviously, I know that if they have any hope of stopping my extremely righteous plan they will use it, so this are the extra steps I've done to ensure that will be impossible: 1. Every satellite sends a laser beam to the other 5 nearby satellites. The beam is encoded so it can't be spoofed from Earth. Should the encoding beam stop\send the wrong encoding for longer then a second all the satellites will launch their nukes & stop their own heartbeat laser beams thus triggering a cascading launch of all nukes from all satellites. 2. The heartbeat beam acts as a sort of death man switch so should any satellite be destroyed again a cascading nuke launch will result in all other satellites. 3. If any satellite detects the launch of anything from earth to space... you guessed it, cascading nuke launch. 4. I have 100 dedicated henchman all over earth with a mobile device (a modified very strong laser pointer) that is capable of triggering a cascading nuke launch should any of them decide the world governments are not following my orders. This device is laser-based and can only trigger a launch, not stop it. 5. There is no communication or control channels to the satellites, even I can't stop them. 6. Should the satellites not detect a decrease in the amount of pollution pumped to the atmosphere following a preconfigured amount, you can probably guess what will happen. Seeing as there are no humans in space in the time of launch capable of manually breaking into my satellites (I also have a kamikaze satellite going to take out the international space station), there is no network for anyone to hack into. Any new launch of anything from Earth to space will trigger the nukes from launching faster then it will take even the fastest of modern rockets to cover the distance between the atmosphere and my satellites, and the destruction of any satellite will trigger the nukes from all the other satellites in less then 2 seconds (yes I know it's risky and that random space debris might mean the death of billions of you but that's a risk I'm willing to take). I can't find a way for anyone to stop my plan. **The question** Am I right, given a modern tech level? Is there nothing that anyone can do to foil my plan? To be clear, I will consider any of the following to be my plan working as intended: 1. Earth obeying my conditions. 2. Humanity being (mostly) wiped out. Is there anything I missed? anything anyone can do to stop me? **Edit** Because it's a repeating question assume all sensors will never fail... if I'm smart enough to launch this entire system to orbit without anyone knowing I'm smart enough to build a fail proof sensor (& movie logic is in place). **Edit some more** Because this are also repeating questions I'll answer them too... my henchman (well henchbeing... there are a couple of females and a intelligent hamster in the mix as well) are all 100% loyal and will never disobey me or work against me and will gladly thank me for the chance of dying to obey my orders... I made sure of that beyond any reasonable doubt by having them each surgically given a mind control chip, Also I'm in a super-duper ultra max secure nuclear fallout shelter that will take weeks for even the strongest armed forces to break into. [Answer] First issue is that your system has so many "fail-safes" that a false positive is pretty much guaranteed to trigger a launch well before anyone has time to even discuss how to reduce emissions, much less, see any such plans through. If just one of your 6144 sensors malfunctions, or a solar flare messes with a signal, or XYZ corp doesn't get the memo in time and launches a satellite anyway, etc. Second issue with this plan is that many governments already have anti-ballistic technologies. While most governments are rather hush-hush about the effectiveness of these systems, my bet is that you'll nuke all the 3rd world countries while the US, China, etc will probably detonate all your weapons in the upper atmosphere. There will be some significant environmental damage, but some nations might see this more as an opportunity to eliminate competition than a threat to their own safety. Third issue with your plan (and this is the kicker), is that you will be unable to make that many nukes without someone noticing. The hardware and materials to make nukes is very specific and closely monitored by governments all over the world. Chances are, you will be discovered before your first satellite makes it to space, and WAY before you can deploy 256 gigatons worth. **So, how to make this plan work better?** To counter the 1st problem, you should consider having your loyal servants receive a notification if anything is out of order and if a set number of them agree that there is a true-positive, then they order the attack. If the governments of the world believe your system will kill them even if they do what you say, they will defy you no matter how small their odds of success. For the second problem, don't arm your satellites. Make an actual array of communications satellites, and towers, fiber optic cabling, etc. An actual com gird will not arouse suspicion nearly as much as orbital nukes, but having control of it will be important. Instead of an orbital strike, you place a nuke in every major city around the world which can be detonated by your private network of highly redundant communications systems. Also, this means your nukes are way easier to hide; so, there is no need to detonate them all at once. If the USA does not cooperate, just blow up New York. World governments are still just as clueless about where your other nukes are; so, you still hold leverage to improve the world without destroying it. Also, this means you can work with smaller payloads. No need to buffer your arsonal with a bunch of extra warheads to account for what will be shot down, just do one nuke per city, each one only as big as it needs to be. This will mean a smaller nuclear program footprint to arouse suspicion, and less environmental damage if you have to make examples of a few cities. For the last problem, your mega-corporation needs to invest in technologies that are LIKE a nuclear arms program, but not. You can't just hide the fact that you are enriching tons of uranium to make bombs, but perhaps, you could be enriching tons of uranium to make power plants, while cooking the books to ALSO be enriching tons of uranium to make bombs. By eliminating the need for guidance systems, heat shields, complex programming, and other components of ballistic missiles, your activities will look mostly benign. You could not do this alone, but if you position some of your 100 loyal folks in the right places in your supply, finance, and inspection chains, they could make stuff disappear while making everything look like it all adds up. This would give you a much better, though be it still small chance of going unnoticed. [Answer] > > Is there nothing that anyone can do to foil my plan? > > > Accepting the hand-waving, you're holding the world hostage and making demands presumably because **you want your demands to be met?** The problem is that **you handed a trigger to all interested parties**, who are free to make their own demands. Every government and terrorist organization (big enough to launch *anything*... triggering your system) now has a credible Doomsday device. Your demands will be lost in the **sea of other demands.** [Answer] Yes, nations who are stupid enough to allow a thousand of what are obviously nuclear missile platforms (I mean those things are *big*) to be placed into LEO do deserve to be manhandled this way. However... I can see at least one scenario: the evil overlord's systems fail to work as planned. The reasons are numerous: 1. Someone building these nukes realized how they'd be used and sabotaged one... or more... 2. A henchman has a change of heart but knows the only way to foil EO's plans is to push the button. 3. A henchman turns on EO and demands he acquiesce to HIS demands or else he pushes the button. 4. Multiple henchmen turn, threaten EO and each other, and one of them pushes the button. 5. The worst possible case: because it's very difficult to TEST such a system (in order to test it you have to *build* it and then *use* it and *then* deploy another one), then there are terrible bugs in the software and hardware that may spell a worse disaster than total annihilation: a *partial* annihilation that causes the slow and very painful death of humanity. 6. A variation of #5 is that, due to the inability to test the deployed system, any number of problems prevent it from being able to carry out its mission, with the result that maybe Costa Rica gets nuked, and the rest of the world is suddenly united in a fervor to eliminate the EO and his apparatus post haste. Fast forward to a new fascist world empire or something, and we're back to misery, but we're not dead, and the EO is dead (if lucky) or alive and very unhappy. [Answer] * The defenses you provided are inadequate to prevent the whole network from being taken out at once. * **There are methods of taking out all the satellites instantly from the ground without launching anything**. + The U.S. military has had the technology to make multi-megawatt one-shot chemical lasers for decades. + Build 1024 cannons that sit on a semi-truck. + Ship them all over the world. + Aim them all at once. + Give the command to fire. + All satellites vaporize instantly. + Even if one or two of the satellites get off a shot, Israeli made portable anti-missile trucks systems like David's Arrow are capable of cleaning up any warheads that make it close to the ground (with 99.9% probability). * **The US government doesn't need to launch anything to take out your satellite network.** They already have satellites in orbit that are designed to take out enemy spy satellites. The radars on your satellites all face the earth. The satellite killers would coast in from above and take out your satellites. * **Assuming you want to live then your threat of blowing up the world is just a bluf**f, and there is nothing to stop others from blackmailing you into sharing power. + One of your 100 henchmen or some group of them could threaten to ruin everything and set off the nukes if you don't share power. + Any world government or private aerospace company could make the same threat by threating to launch into space and set off the satellite network.**- Even if the world cooperated you can't prevent solar flairs form periodically blinding your network and possibly setting it off.** [Answer] Others have mentioned that your starting premise is completely bonkers, but then permitted it as a handwave. I don't think that's reasonable. As @nosajimiki wrote: "Chances are, you will be discovered before your first satellite makes it to space, and WAY before you can deploy 256 gigatons worth." But the problem is not limited to the fact that making the radioactive material for such nukes secretly is impossible, though it just simply is. Nor that making the targeting, containment and detonation systems for such nukes secretly is impossible, though it just simply is. Nor that putting it on a spaceship without a bajillion engineers knowing every component of it intimately is impossible... though once again, it simply is. Nor that you would have a damn hard time finding a single engineer that would be OK with putting a nuke in orbit, and you have to find hundreds, not only in your organization, but in many others that your organization depends upon for supplies and services. Nor that such things would be *heavy*, and launching them would require one of a very small number of launchers. Nor that any satellite launched is studied and known deeply in multiple wavelengths, exactly because no superpower trusts any other not to sneak nukes into satellites, and are looking for exactly the telltale radiation signatures. Nor that both Russia and the USA have made and tested satellite killers which are already deployed so would not have to even use @Willk's suggestion that "a militia of satellites is drafted into service". The problem is in the combination of all the above and far more. Now, Elon Musk might be the only private person on the planet who could overcome even some of these, having a heavy lift vehicle, and a horde of religiously-fanatical engineers following him, and spectacularly good guidance systems. But he has no nukes. Donald Trump or Vladimir Putin could do the nukes, the launchers, and the engineers. But they still couldn't do it secretly. Launching a constellation of over a thousand nuclear satellites without detection or any engineering fuckups... that's simply not possible. The scenario you depict won't ever be possible. ...until the first one of them has a base off-planet. Then, replace "a thousand nuke-bearing satellites" with "a thousand rocks a few hundred meters across or more that can be launched into the Earth's gravity well, gaining kinetic energy from gravity until impact". Or even just one big rock a few km across. [Answer] > > Any new launch of anything from Earth to space will trigger the nukes from launching faster then it will take even the fastest of modern rockets to cover the distance between the atmosphere and my satellites > > > **What's that behind you?** Your satellites are watching vigilantly for threats from below, but there are lots of satellites already out past Earths orbit. Lunar reconnaissance satellites, Indian moon missions, solar explorers and so on. In this scenario, a militia of satellites is drafted into service, gathered under the guidance of two Indian astronauts on their way back from the moon. This ragtag bunch of misfits quietly assembles behind the nukes and then on the signal wipes them out before they have a chance to react. [Answer] So, here is why your plan fails. Rather satisfactorily, too, it's because of the classic "evil overlord" problem - being **too evil**. > > ... Each satellite is equipped with the following: > > > * 12 of *the largest nukes humanity has ever seen* (each equal in explosive power to the strongest nuke ever produced by a "government") ... > > > Evil overlords traditionally leave minor details to their henchmen and scientists, so let's assume you just ordered "the most powerful" types. A dozen rather massive thermonuclear (H-bomb) warheads for every satellite. What do you know about the design of those, Mr. Overlord? Apparently not enough. You see, if you'd just gone with *normal* weapons, this would probably work. But you had to go with the "strongest" kind..... and therein lies your plan's inevitable downfall. Nukes fall into 2 kinds. In a fission weapon (A-bomb), you collapse some fuel and provided it's held together for the fraction of a second it takes for a sizeable wallop of fission to happen, you get an explosion. That's partly what the very strong steel around it, is for - so it can't fly apart before that's happened. In a fusion weapon (H-bomb, technically fission-fusion, or for the most powerful, fission-fusion-fission or even more stages), an initial fission bomb gets going, but the radiation is redirected to a chunk of fusion fuel, which is immensely compressed and heated by the sheer heat and radiation pressure of the primary's X-rays and their effect on the nearby material, and therefore itself starts a fusion reaction. Optionally that's surrounded in turn by more fission fuel, which is itself irradiated and provides more pressure and containment from the outside, and so it goes on... Nukes are tricky to make. Very ticky. Very, very, very tricky. Fusion weapons are immensely more delicate and tricky than fission weapons. They all require insanely fine timing and precision, but fusion weapons far more so. In a classic implosion fission design, you have to compress a sphere almost perfectly - from all sides, with microsecond or better precision. Fusion weapons are worse - they need insanely tight timings - I think they were once compared to lighting a fire from 2 treetrunks in a thunderstorm using a single wet match balanced on an airplane wing or something crazy. (OK, I lied about the airplane wing, but you get the idea). They aren't just like gunpowder where you light it and they go off, or a lump of steel where you drop it and it smashes whatever's below. They need insanely tight tolerances for every part of the process. Insanely precise-engineered shapes for containers, and insanely precise-shaped explosive charges. Insanely precise explosives so the shock fronts are guaranteed to reach exactly the right time at the right place. Insanely engineered initiators to start off those shock fronts. Insanely precise computer-controlled multi-stage initiation sequences to fire these off at correct nanosecond intervals. Insanely precise physical positioning of components to ensure the signals do what they should, where they should, at the precise intended nanoseconds of the initiation sequence. You get the idea. If that firing sequence doesn't happen exactly as it should, or the case is distorted in an unplanned manner (by unexpected asymmetric heat), or whatever, then all you have left is a mildly radioactive blob that does nothing, or fizzles, or produces a squelch that's asymmetric in time or space by some miniscule amount. What you *don't* have, is the immense and perfectly balanced pressure build-up in microseconds/milliseconds needed for the primary fission explosion, and if you did, you wouldn't have the pressure correctly balanced for the main fusion stage. Which means that every nuke ever built, is also an insanely precision engineered product. Disrupt its precision even slightly, cause anything to move a fraction or work not-as-designed, and you have a lump of mildly radioactive debris and not a lot more. With an A-bomb that debris is at least likely to do severe damage (lots of plutonium which is horribly toxic, everywhere). But you wanted "the most powerful" weapons, and the most powerful fusion weapons will aim to optimise *fusion* (not fission) reactions, so a lot of their fuel is honestly pretty harmless in the great scheme of things. And it's inside a casing for re-entry protection, which will contain it in the event of a crash. Which means, my dear Overlord, your plan is - colloquially - screwed. Because down here on earth, we've been building about 24k missiles with proximity detectors, that can generate a decent EMP, and also for what its worth, will try to home in on your missiles. 2 each for your 10k warheads, just for safety. The nice thing about EMP (or indeed nuclear missiles if that's what a decent EMP requires) is that they don't have to be a direct hit at all. They only have to be close enough that either the EMP or the explosion disrupts the electronics. And that's not hard to do at all. Then your missiles are so much dead weight with a little dirty fuel in a big casing. Aside from the EMP itself, shock/blast waves and intense heat/radiation won't be great for any warheads within quite a distance as well. (There could also be high speed debris from damaged warheads, but that's less clear and might have little or no effect, so I'm ignoring that part.) As a bonus, some will be hit directly (not all, direct hits are tricky). Others will have their altitude sensors - needed for precise firing - wiped out for sure. Given careful planning and simultaneous launches from underground silos/submarines, I don't think any will actually explode as planned. If only you'd stuck to dropping huge lumps of RDX or something that wasn't so dramatic or evil-sounding, but also wouldn't be so affected by disruptions.......... [Answer] Your plan has a fundamental flaw that is nothing to do with technology or process. **Human beings are stupid and won't believe you.** I mean it's not like they don't already know the earth is doomed if they don't cut back on carbon emissions, but it isn't happening. So basically there is always going to be someone, some government or organization, who thinks that you are bluffing. Or thinks they have found a way to defeat you, even if they haven't. They will try something - destroying a satellite, killing your henchmen, nuking your own hideout (wherever that is - and don't try saying "it's in a big city", that won't stop them) And since all your countermeasures involve blowing up the earth, that is what will happen. You will undoubtedly end up as ruler of a smoking ruin of a planet. [Answer] **Just push the red button** You don't care if the population of earth obeys you or is destroyed, so just push the Launch button and be done with it. The world's nations have been asleep at the wheel to let you amass a nuclear arsenal greater than the combined force of every country on earth, and to then put them into orbit on "telecommunication satellites" that are many times larger than any other communication satellite ever launched. You have everything you need to destroy the planet, so just do it already - what are you even waiting for? As stated by the OP, victory conditions are either subjugation or annihilation of humanity. Annhilation can be achieved with near-certainty *right now* - there is no reason to take even a slim chance of failure for the domination win. Going for domination allows people time to thwart your plan, and it'd be difficult to foresee all possible countermeasures. If you go for annihilation, the only way to fail is to have the nukes shot down en route from satellite to target, dramatically limiting the time and options for those that oppose you. [Answer] Well it's a long shot but parts of Earth could survive if some of the nukes are intercepted. Missile defense systems using counter missiles, bullets or lasers are plausible, and the kind of thing that would be a government secret. Stopping all the nukes is unlikely but possibly the USA/China stops all/most of the nukes heading for them leading to partial survival. Nuclear winter would still be a factor but easier to survive than being nuked. Alternatively secret government attack satellites might be in orbit and could possibly destroy several of your satellites prior to launch. Stopping all of the satellites is once again probably impossible but taking down some seems plausible. [Answer] **Leave the Planet** A possible solution is to send as many people into space as possible to avoid the impending nuclear destruction. They might not even need to leave Earth’s orbit, just get above the nuclear explosions. Your best option for this is likely an SSTO (single stage to orbit) spacecraft, essentially a space plane. I believe Elon Musk, CEO of SpaceX, has plans to develop space planes for commercial purposes. A government could easily commandeer their spaceplanes and use them to ship people into space. Although, i doubt you would be able to get many people off the planet and, even when you did, where would they go? The ISS is doomed and wouldn’t be able to hold enough people anyway. You could possibly leave people on the moon and sort things out later. **Underground Bunkers** A traditional but effective way of dealing with aerial (or orbital this case) bombardment is to get people underground. Essentially you have nuclear missile facilities, like the one in Switzerland, where the population goes in the event of a nuclear attack. This way, whilst the surface is being destroyed, a significant portion of the world population will survive the attack, far more than 0.01% you anticipated (though regrettably, those in less developed countries, such as many countries in Africa, are significantly less likely to survive). **Fight Fire With Fire** So you have thousands of nukes orbiting the planet? They are just sitting ducks up there: their trajectories are easily predictable, you have no way of communicating with them to move them (which you admitted to yourself) and there is no mention of them having any RCS thrusters or the like to dodge an incoming missile. Whilst your satellites may be able to detect any missiles fired at them from earth, that is hardly an issue. Small, heat-seeking counter-missiles can be fired from everywhere on Earth as soon as you fire your nukes. Triggering the sensors wouldn't even matter at that point, the payload has already been fired. The idea is that these counter-missiles would detonate your nukes well before they hit the ground and, because of the size of your nukes, the nuclear explosion is likely to cause a domino effect, destroying the rest of the payload and the satelite that fired those nukes. Doing this to the first missile you fired from every satellite could save billions of lives. 1024 missiles is not a lot relative to the entire world’s weaponry. Also, they don’t even have to be large or powerful missiles, just a small explosion to trigger the nukes that you fired. Whilst the population of Earth may have to worry about a nuclear winter, at least many people have survived and your plan has been foiled. **Operation: Smokescreen** Whilst you mention your sensors will never fail, perhaps this can be used against you. It may be possible to trick your sensors or blind them. Using emitters, it may be possible to replicate the signal the satellites are receiving which prevents them from detonating. Doing this to all the satellites in the world could buy humanity some time, you can now no longer control when they do or don't fire, it doesn't matter anymore if your henchmen stop the signal, the satellites are still receiving the same signal from other emitters, nullifying your control. Alternatively, you could also trick the sensors into believing nothing has been fired from earth by relaying a false signal to the sensors. Its essentially the equivalent of placing a photograph in front of a CCTV camera. Again, this would buy people more time to deal with the satellites. **Call Your Bluff** If your goal is to become the ruler of Earth and everyone and everything in it, you aren’t actually going to fire the missiles. Okay so lets assume you aren’t bluffing and you actually fire the missiles, everyone and everything on Earth is killed and destroyed. Now what? You are now the king of dead world. An irradiated, uninhabitable wasteland of a planet. No architecture exists, no life exists, everything has been annihilated by your hand. What was the point? There is no one rule, no governments to control, no wealth to accumulate, there is nothing. If your goal was to rule the world then you have failed, there is nothing left to rule. Your failure will haunt you for as long as you live and will be evident long after you’re gone, the husk of a planet you left in ruin will remain there, lifeless, for the rest of its days. Humanity can simply call your bluff, you will not destroy the world because you stand to gain nothing by doing so. [Answer] **You don't have enough nukes to destroy humanity.** You've got: > > 1024 sets of "12 of the largest nukes humanity has ever seen (each > equal in explosive power to the strongest nuke ever produced by a > "government")" > > > That nuke is the [Tsar Bomba](https://en.wikipedia.org/wiki/Tsar_Bomba) which had a 50 megaton yield as tested but was designed to go up to 100 megatons. So you've got about a million megatons. In an average year there are 45 hurricanes. Together they have an equivalent yield of [five million megatons](https://www.theglobeandmail.com/technology/science/the-13000-megaton-storm/article986153/). Sure it's mostly spread out, but that's happening every year. A lot of people are going to have a bad day (in 2016 there were 336 cities with a population of over 1 million,) but humanity will probably bounce back. [Answer] There is one critical weak point in this whole scheme, and that's YOU. The minute you announce your evil scheme, all of the world's special forces will be mobilized to find and eliminate you, personally. The scenario ends with you taken out by a sniper before you have a chance to signal your minions. They can then impersonate you, order the minions to stand down and return to base, capture or kill them all (more snipers), then work at their leisure to find a way to safely deactivate the satellite network. [Answer] ### Normal launches aren't the only way to space Your satellites are watching for any kind of rocket launch, but you've said nothing about watching for things that are already in orbit. For that reason, I assume that you're looking for some kind of launch. If you examine the [SABRE](https://en.wikipedia.org/wiki/SABRE_(rocket_engine)) rocket engine, you'll see that it is likely that it can enable a Single Stage To Orbit design. Don't worry about reentry, and make the plane invisible to radar, and you've got a plane that can probably make it to space without looking like it's going there, at least in the range that you're probably looking for launch signatures. If I launch it off the back of a modified Hercules or the like, I won't even be running rocket engines below 30,000 feet. Alternately, requiring a bit more work, someone could build a railgun and launch a satellite directly into orbit. As it's ballistic until it hits space, it would probably escape detection. A person can't survive this kind of launch, but a satellite that would attach to one of your satellites (and thus enable hacking the network) would be possible. [Answer] One of many problems with your plan is that many nations are developing ground-based lasers that can shoot down satellites. If these work, they could take down all the satellites at once with no need to launch anything. An alpha strike of lasers could in principle take all the satellites out at once, at the speed of light. You also can’t just force everyone to do what you want by threatening to nuke them, especially when they can nuke you back. If you’re bluffing, someone will call you on it. If you’re not, someone will call you on it. There’s a reason the US and Soviet Union didn’t order each other to surrender or be nuked. [Answer] Seriously ? Your plan doesn't account for a simple fact: **Human nature**. As the intended future ruler of humanity, you should be better educated in that area, seriously. This is going to blow up in your face, literally. Because all it takes is **someone, somewhere** who will intentionally trigger your system, cross your line, and get all those nukes raining down on everyone. There are more than enough wakos, religious nutjobs, mentally ill people, psychopathic dictators, sociopathic leaders of so-called free countries, and given that you were able to execute your plan - people within your circles you needed to be smart (this is literally rocket science) and thus probably saw your plan or large parts of it while it was still being built *and yet didn't stop you*. In short: There are enough very, very dangerous people in the world that it's already a little surprising we haven't nuked ourselves yet. You just made that so much easier that it is almost sure to happen. [Answer] Your plan will fail, nations can just wait you out - nuclear material decays. It'll only take a few years before you don't have nuclear weapons in space, just expensive missiles carrying non-fissile material. <https://www.reddit.com/r/askscience/comments/xc9n5/how_long_does_a_nuclear_warhead_last_in_storage/> [Answer] You need a few tweaks to make your plan more likely to work. First off you are never going to be able to get the nuclear material together without being noticed. Uranium and Plutonium fuels for fission warheads are radioactive and very easy to detect. What you need is to develop a pure fusion bomb, which can be detonated from non-radioactive lighter elements. I suggest you form an energy company possibly specializing in high-end batteries to allow you to amass large quantities of lithium ([useful for fusion](https://en.wikipedia.org/wiki/Aneutronic_fusion#Lithium)). If possible place your factory in a sparsely populated region to allow you to conduct research without being noticed, maybe someplace like [Nevada](https://en.wikipedia.org/wiki/Gigafactory_1). So you have your undetectable bombs, but how do you get them to orbit without anyone noticing. What you need to do is start your own rocket company, but you will also need to come up with a reason to launch thousands of satellites. The answer is as you've said is to sell them as [communications satellites](https://en.wikipedia.org/wiki/Starlink_(satellite_constellation)). The trick here is that of the proposed 10,000+ satellites launched most of them actually are communications satellites, so that periodic inspections and a functioning communication network make it much less suspicious. You are also going to need to be active on social media and get many people interested in you; something like a cult of personality needs to be generated. This makes it much more likely to get trusted lieutenants who will follow you and more credible than turning over governance of the world to a complete unknown. Besides if you do the things required to put this plan in place people will notice. So rather than try and hide, which will fail, hide in plain sight as an eccentric billionaire CEO. [Answer] I can see two countermeasures. First your satellites have to communicate to maintain proper orbit and not collide with space junk, so there is a way it. Your agents communications also has some kind of authentication code so that is a second way in. second, the world just needs to launch its counter measures to orbit all at once, they know exactly where your satellites are and a high atmospheric detonation is not a huge problem. There are literally thousands of missiles available to try and knock out your warheads before they reach effective altitude, not to mention plane based lasers, and a few other ideas. Warheads are delicate machinery a counter detonation can knock them out the emp has a decent chance as well. if your nukes are designed to detonate high they have a decent chance of knocking each other out. [Answer] **Problem: Your plan will fail when attempting to make nuclear weapons** You plan calls for 12,288 nuclear warheads. Saddam Hussein’s Iraq was invaded by an international military coalition because it *thought* about *maybe* building *one*. Saddam had the largest army in the Middle East, and it didn’t ammount to much. How many armored divisions does your evil rich guy have? Assuming you could get away with building one nuclear weapon, you’re not going to get away with building 2x the nuclear weapons of the holder of the most nuclear weapons in the world. That requires lots of uranium and plutonium. Ignoring that these are some of the most heavily regulated and monitored commodities in the world, buying that much is going to make the price of those things go up a lot. Even the stupid investors in your evil conglomerate are going to notice that you’re buying vastly more plutonium than could ever be justified by some benign purpose. **Solution: Don’t use nuclear weapons in your killsats** Your killer satellites have the advantage of being *in orbit*, which means any projectile they launch at the Earth will pick up lots of energy for free thanks to Earth’s gravity. You simply *don’t need* nuclear weapons to create great destructive power; you can throw small asteroids or other rocks and get as much or more devastation. If you use asteroids, then you have the additional benefit of being able to expand your cover story to explain everything; Evil Corp is launching all of that stuff into space because it’s becoming the humanity’s leader in the space mining business. After all, it’s only the logical thing for your evil rich dude to do considering that he’s been cultivating a public image of caring about the impact of humanity on the Earth, including its scarce non-renewable resources like metals. [Answer] <https://en.wikipedia.org/wiki/Kessler_syndrome> Kessler syndrome might be a cool way to ruin this plan. It's sort of an idea where there's a ton of space debris orbiting earth at incredibly destructive velocities. If such a piece of debris impacts a spacecraft, it instantly turns it into more space debris, causing a chain reaction. So the idea is to have as many as possible spacecrafts crash, cross your fingers to cause a chain reaction. If it works, at least some of your satellites will instantly be wrecked. Possibly even many or all. [Answer] Assuming that it reached this level, then it would not fail. All insanely hard and unlikely to succeed work is already completed. The hurdles on the way: * 1024 communication satellites? To cover all Earth Iridium needs 76 + plus 6 as back up. * each Iridium satellite weight at launch 689 kg. The biggest nuke actually deployed as a weapon by the US was B53 with meagre 9 megatons weighting slightly above 4 tons. Assuming that you made some breakthrough to make them a dozen times more powerful, we're talking here about satellites weighting 50 tones. [For comparison International Space Station weights 420 tones and its the most impressive human space installation. So you effectively need to launch in to space objects weighting at least 122 times more than ISS in a way that no one raised eyebrow] * Oh... and cold war era quantities of weapon grade plutonium, lithium-6 and deuterium Conclusion: military and intelligence agencies that missed such overkill space and nuclear project are unable to defend against a mentally unstable person armed with a knife, not mentioning someone with nuclear warheads. [Answer] Make very sure that all of the ground devices and installations needed are independent of the power grid. If your demand to "switch off these and these power sources" is followed verbatim, it could shoot you in the foot in a very ironic way. [Answer] The problem is how loyal are your minions? Will they commit mass suicide if you are arrested or killed or would they be tempted to take your place? What if they start demanding things on their own? Looks to me that you all have the same power, so they'll start seeing themselves as your equal. Surely the CIA, KGB, etc will make sure that they do. Now instead of being an evil overlord with total power you'll have to deal with 100 others. What if the world accepts you as their evil overlord, but then, over time, your minions start dying from what looks like natural causes? You suspect a foul play, but you can't respond because the only card you have to play is to trigger the attack. Further more, they might just reject your demands out right, or string you along with promises - you won't have any recourse other then triggering the satellites so they'll just keep pushing to see how much they can get away with. "You want to move into the White House? Absolutely! Just give us a few days to get the president out and renovate for you. In the mean time let me get you a hotel... Hmm, it seems the only room available is in Budget Inn - DC is so crowded because every is here to see your Evil Imperial Majesty's coronation... By the way, that's being slightly delayed - nothing to worry about - we are just trying to make it the most magnificent event ever and that takes time, you know... " [Answer] I want to look at this from a different angle. Let's assume you have all these nukes. Let's assume you can bully the world into submission. Let's assuming we can flip a switch on pollution and climate change. **You still can't win.** Let's start with your demands. The first demand is so trivial it doesn't need addressing. If we have to, I'm sure we can manage without space-based thingymagoogs. The second demand is actually where it falls. I'm not even talking about how realistic it is, but about what the ask itself. You're asking for the end of pollution. That's noble. It sure would be nice. But the problem is you *are* asking. Why is it a problem? *Scenario 1:* the world complies. No more pollution. Everybody wins. Then of course we move to the next demand. *Scenario 1.1:* the world complies, again. You are ruler. Your only downfall is you're only ruling by fear. History shows it rarely ends well for you. There will be a lot of angry people vs exactly one of you. Do you feel lucky? Does victory look like a bullet to the forehead at your inauguration? *Scenario 1.2:* the world tells you off (about the ruling thing). Then what? Well, before we go down that rabbit hole, let's back up and explore scenario 2, because it'll end up about the same. *Scenario 2:* the world tells you off (about the pollution thing). Then what? See, your problem is exactly *here*. You care about the fate of the planet, you wouldn't be mounting such a crazy scheme if you didn't. You know what people that don't care do: nothing. **You care.** But if the world flat out refuses, what does that tell you? That they don't care. Your threat is to blow up the thing you care about. They'll laugh at your face and tell you "go ahead, see if we care". And did I say they don't? *Scenario 2.1 which is also Scenario 1.2.1:* you trigger the end of the world. Not only have you destroyed the thing you cared about, but at best you're the only thing left alive on a lifeless rock. How long before you go mad and/or just shoot yourself in the head? I know this counts as achieving your plan as per your question, but is it really a win? *Scenario 2.2 which is also Scenario 1.2.2:* you half-trigger the end of the world, or trigger the end of half of the world. The rest is bullied into submission. We're back to scenario 1.1, where you rule only by fear and it doesn't end well for you. *Scenario 2.3 which is also Scenario 1.2.3:* you don't trigger the end of the world. The world has called your bluff and you gained nothing. Likely, they kill you anyways for trying. *Scenario 3:* the world complies. You rule by fear, but somehow everything goes fine. Eventually, you die of old age. The power vacuum you leave is so immense the world goes back exactly where it started, if not worse. I suppose in this scenario you don't live long enough to see yourself lose, that *might* count as a win. --- Your plan, like many evil alleged geniuses' plans, you lack a critical part: an endgame. If your actual goal is power, forget about it and be happy being the head of the largest conglomerate on Earth. That's more power than most presidents anyways. If your actual goal is to save the planet, forget the whole doomsday scenario. Use your resources and technology to fight climate change. Do something about it rather than asking someone else to solve it for you, you hypocrite. You've got the power to be the hero after all. [Answer] This "evil overlord plan" to make someone overlord of earth seems more like a simple "evil plan" to wipe out most of humanity, probably including the evil would-be overlord. It has too many atomic weapons on a hair trigger dead man's switch. Unless everything goes according to the optimistic plans of the would be evil overlord the dead man's switches will be activated and the bombs will be launched. Then the term "dead man's switch" will become highly appropriate because the would be evil overlord and his minions will very probably be among those killed in the atomic holocaust. [Answer] You should have read more about waging Nuclear war... you're over powered, under built, and exposed your entire arsenal's location, and you threatened a first strike. Anyone of these is a bad play in Nuclear Warfare. All of them mean you're an idiot. **MORE POWER** The only time nuclear weapons were deployed in war was the famous Hiroshima and Nagasaki attacks... and had the latter not convinced the Japanese, the U.S. was going to have to deal with a bit of egg on their face... They had already wasted 2/3rds of the total nuclear arsenal... Luckily the Japanese were gambling that a full 100% of the U.S. nuclear arsenal was used to bomb Hiroshima, so when the arsenel turned out to be at least twice as big as their estimates, they figured better not find out it was thrice as big. I say this because the largest Nuclear Weapon ever made was the Tsar Bomba, which had a yeild of 50 Megatons of TNT and is to date the largest manmade explosion ever to occur on Earth... however... the Tsar Bomba was never a feasible war weapon... it was way to big to fit on a a plane suited for combat conditions... they had to remove the bomb bay doors and lower the yield just to test the thing. Now there are no theoretical upper limits to a bomb's yeild in an ideal setting, but the Atmoshere will cap that limit hard because as soon as it breaks into Leo, the yield becomes useless... and delivery vehicle which has to carry the thing. Now, you solved the delivery problem with the space based launch platform except you didn't... Getting a massive bomb into space like the Tsar Bomba is gonna cost a pretty penny. NASA says that for every pound of payload, it costs 10,000 dollars to launch. The Tsar Bomba is a 60,000 lbs. For 1 satellite's compliment of Tsar Bomba nuclear bombs, your paying 7.2 BILLION! Not for the whole satellite... not for the bombs on the satellite... just to put the bombs that you completed with more disposable cash you have lying around... this is just to get 12 bombs off of earth and into space. You can't just move that amount of money around and not get noticed. Banks start to give you funny looks if you're moving sums of 10,000 dollars regularly. And even then, and forgive me, I'm no climate change expert, but I'm pretty sure there are easier green energy solutions that could be invested in than a hostage crisis of 7 billion people. I mean... most green advocates don't see nuclear power as a solution anyway. **So many Nukes... Pointing at you** Okay, so one of the things people don't get is that Nuclear arsenals aren't built to be offensive weapons... but defensive weapons... against other Nukes... It's at this point that you're head starts going around in circles... it's okay... it's all part of being M.A.D. Of all the nations of the world, the United States is the only nation that had anything remotely resembling a First Strike Policy... considering that the U.S.S.R. lost the most troops of any nation in World War II and they were still able to beat back the Nazis all the way to Berlin in an utter curbstomp of a battle, the United States did plan for limited tactical strikes against reserve troops during a possible conventional war with the U.S.S.R., but even then, they would rather launch Nukes after Russia Launched them... insinuating the U.S. might be the one to escalate a fictional war to nuclear war was enough to lose Pentagon assistence for a movie. The Day After, which was critical of a nuclear war, famously lost it's backing because they were dedicated to the point that after the Nukes are let loose, it really doesn't matter which side fired first, because surviving a nuclear war was less preferable than dying in one. Any way, almost every country built their weapons to stop another nation they didn't like bullying them with their own. The U.S. built them to avert an invasion of mainland Japan, a military action that had such a high causualty list, that even today the U.S. has yet to exhaust the Purple Hearts (Awarded for Injury in the line of duty) ordered up in preparation for the invasion. The U.S.S.R. built them beacause the country that had them had already bombed a country into submission with merely two and was not a fan of Communism at all, prompting the U.K. and China to develop theirs and the French built theirs because they'd be damned before the rellied on the British, U.S. and U.S.S.R. to save them from the other two. Meanwhile, India was getting nervous about sitting on the border with a historical enemy with nukes and felt it was gonna get caught in the crossfire of the U.S. and U.S.S.R. if they actually decided to start trouble, which Prompted Pakistan who didn't care much for a historical enemy on their border being a nuclear power. Isreal never built the bomb to defend against every single one of its neighbors, no sirry Bob (Officialy, Isreal does not comment on whether or not they are a nuclear power, but as secret keeping goes, their status as a nuclear power ranks somewhere between "Who is Luke's Father" and "Gee, I wonder who Superman really is.") and they probably didn't develop them with South Africa, who's apartheid policies made them hated by pretty much everyone all at once. All to ensure M.A.D. doctrine was enforced... which is basically two nations agreeing, "if I'm going down, I'm taking you with me." So you have First Strike, which in an all out scenario, will target just about every nuke that they know about in the hopes of stopping the Second Strike. At the height of the cold war, U.S. military planners estimated that in the event of a Nuclear war with Russia, the person who makes the First Strike would destroy 97% of enemy's total nuclear arsenel... So both sides built enough nukes to assume that only 3% could destroy all of their enemy on a Second Strike Nuke... the goal of the Second Strike is to launch everything so that the 3% could get through with enough force to count as all out nuclear war. The Second Strike is so critical to Nuclear nations that when Ronald Reagan announced the Star Wars Program, the Soviets panicked because if it was true, it would take away their Second Strike (The Soviet's First Strike capabilities were greatly embellished... they adopted a Second Strike only policy because they could cover for the fact that their rocket fuel was too corrosive to the rockets to keep in the fuel tanks... fueling took the better part of a day... where as the U.S. missiles lacked this problem, and if they saw the fueling occuring en mass, could launch an unopposed first strike.) In your proposal, you're basically declaring intent to launch a First Strike, which will prompt second strikes from anyone who takes your threat seriously... which means they'll probably launch which... well... leads us to your next design failure. *It Came from 20,000 Leagues under the Sea.* Like I said, most nuclear capable countries... especially the ones with extended programs, probably have more nukes than you... and they also have Submarine launch platforms which pretty much enshrined the survival of second strike nukes as they could move and were stealthy. And most missile delevery systems are... well... remember the Space Race and all those rockets we sent up? The Mercury-Redstone, The Mercury-Atlas, The Gemini-Atlas? Well, the Saturn V, which was attached to the Apollo Missions, was the first Rocket purpose built for a NASA space mission... the ones that carried the Mercury and Gemini capsules were pretty much our missiles with the warheads taken out and a capsule for a human to sit in put on in the warhead's place. The same rockets that Americans dreamed would take us to space, were the subject of our Nightmares when they were pointed at Cuba. Space capable missile warfare has been a thing for a long time. And not only does the military have more misiles than you do... But you told the world where I can find your arsenal. As discussed by another answer, I'm not sweating bullets about disarming your nukes... because nuclear bombs are easy to disarm... I can just shot the thing and trigger an exploion of one of the bombs that is mistimmed, I basically stop the bomb from being affective... If I launch some of my own nukes at your satellignt and detonate when its close enough... after all, close only counts in Horseshoes and Hand Gernades... and Global Thermal Nuclear Warfare. Even if we allow for the idea that nuking your station is going to detonate all the remaing nukes, it's still more likely to occure away from earth where the damage is minimal. [Answer] One point that hasn't been brought up yet is the reentry atmospheric heating of your bombs/missles. Coming from orbit down to a reasonable detonation altitude will require a significant heat shield to protect your bomb and material from the intense heat. This adds mass to your launch, and your "communication satellites" will be given much more scrutiny if you have heat shield materials included, as that is not something that one would reasonably expect on a satellite that isn't designed to survive a reentry. [Answer] **Space Junk** One thought I had was 'space junk'. That is, a fleck of paint floating around the earth at 10,000 mph is enough to cause significant damage to a satellite, space station etc. A bag of bolts, or maybe the remnants of an old satellite would be more than enough to destroy your (massive!) satellites (or at least put them beyond use). Without launching anything new, $worldpolice arrange a couple of manoeuvrable satellites get into the same orbits as your satellites, but perhaps do so in the opposite direction as yours. With some careful flying skills, the first in a 'string' of yours is destroyed. The (now much enlarged) debris field from that one flies on at 10,000mph towards the next, and the next. Repeat this for each 'ring' of satellites you own. Given you have so many satellites, they must be relatively close together, thus ensuring we can destroy a large proportion in a small amount of time. I'm not sure we've ever witnessed this occurring, but it's been theorised (and dramatised in the film 'Gravity'). Given you don't launch a nuke instantaneously, it's highly possible that all of your satellites could be destroyed within the 'few minutes' timeout of the communication network + firing time of the missiles. You may be lucky enough to get a few to launch,, but as others say, many nations have defences against such things (of variable effectiveness). You may destroy a few areas, but you're unlikely to get them all - and most importantly of all, your 'war apparatus' is entirely dismantled and your plan has failed. You have no bargaining position left, and as such can be captured and executed, probably relatively easily as you'll have very few friends left on the ground. I'd also point out that your operatives on the ground that can trigger a launch but not stop it are going to have to be very carefully motivated. Apparently it's not impossible (given events of the last few years), but you're just an evil empire, and not offering eternal life to martyrs, so your ability to motivate may be limited. If watching James Bond films has taught me anything, it's that if you want to 'rule the world', you need to do it quietly and insidiously over a long period. Since you have your large and successful Evil Corp, maybe focus on diversifying into espionage and intelligence gathering. Use that information to bribe or influence every monarch, politician, powerful business leader, community leader and even parents of large families to do things your way. Be unseen, yet be everywhere and you'll achieve far more than the 'grand gesture' you're proposing. [Answer] ***Nope.*** For 12 missiles each in 1024 satellites, 12,288 warheads. Assuming a similar size to the Tsar Bomba, that means each satellite is carrying 12 warheads of 27 tonnes, or 288 tonnes in just warheads. The heaviest communication satellite masses 7 tonnes. You're talking platforms that mass over half the mass of the ISS *each*, each more than twice the mass a Saturn V could lift into LEO, and there is utterly no way to diguise that when they're in orbit because basic physics will reveal that quickly. People are going to wonder what the hell you are putting up there when you launch the first one. Note, even if you instead use the design of the American B41, the most efficient in terms of megatonnage per weapon mass, it doesn't help much. You might be able to lift a satellite in one go, but you're still talking something at the very upper limits of the heavy lift. People wondering what's so heavy will still be a problem. But wait, there's more! It takes around 15 kilos of enriched uranium or 4 kilos of plutonium to make an primary, which is the minimum needed to start your bigger bomb. The secondary (and possibly tertiary stage), requires at least similar masses or uranium and plutonium (assuming it's a Tellar-Ulam design), so triple that to 45 kilos of enriched uranium and 12 kilos of plutonium. That's 147 tonnes of plutonium necessary. It took the United States *50 years* (1944-1994) to get 111 tonnes. Note this includes the entirety of the Cold War when the US was producing and exploding warheads like firecrackers. And your guy produces 30% more than that, completely below the radar? So...yeah. If your Evil Overlord has managed to pull this off, the planet is clearly inhabited by such a totally incompetent collection of brain-dead morons, he might as well nuke them and put people out of their misery. ]

[Question] [ The problem: If somebody fires a (kinetic) gun on a spaceship, the bullet is likely to penetrate the hull and cause a host of problems. I want to incorporate spaceships and fighting on them and in them, boarding action and all the other fun stuff in my current project. How could you solve this? * From my other questions and my extensive research I know that it is very probable that kinetic guns (chemical propellant and other) are likely to keep the #1 position in handheld firearms. For example, lasers can easily be nullified by reflective armor. Is that right? In this case, no energy weapons please. * The scenario is low-AI, too. So no thinking or 'intelligent' bullets. * I once found an idea about a material within the ship's hull which 'deactivates bullets'. But just build a body armor out of it, and you’re bulletproof. * Tasers and the like are OK for law enforcement etc. But I plan to incorporate vicious and deadly conflict within a spaceship. So, is there any solution, or do I need to get rid of one or more of these requirements? [Answer] # Bullet holes are not as bad as you think. The ISS would take over 7 hours to depressurize through a bullet hole. <http://www.spaceacademy.net.au/flight/emg/spcdp.htm> Even a few bullet holes still gives you plenty of time to react. In a worse scenario of someone setting off a hand grenade or something that punches a very large hole, humans can still remain conscious in a vacuum for up to 30 seconds, maybe enough time to exit the room and initiate some emergency door sealing or cabin repressurization. Speaking of repressurization, you might have emergency air-replacing equipment to replace air being lost through bullet holes. The capacity of this equipment can be left to your imagination (might be fun to emergency replace massive quantities of air with boiling oxygen directly from the liquid oxygen fuel tanks into the environment system. This could retain pressure for a very long time, but introduce major fire risks (plus pure oxygen at high pressure is poisonous; pressure needs to be kept at a reasonable low. A safety system would regulate this). ### But wait a sec, can a bullet even puncture a spaceship hull? Our current micrometeorite shielding can protect against the energies of bullets at point blank range, by several times. An aluminium slug of 7mm at 7kms can be stopped by whipple shields. That's a kinetic energy of ~36kJ. A handgun bullet at point blank range is more like ~8kJ. (<http://calhoun.nps.edu/bitstream/handle/10945/1233/04Dec_Kalinski.pdf?sequence=1>) The whipple shield is composed of an outer bumper layer, which fragments the projectile before it hits the hull, so is directional and assuming that projectiles are coming from outside (how naive!). So maybe it's not impossible to puncture the hull from the inside out with high powered weapons. But keep in mind this is using current day shielding technology too, and not the new fancy self-healing hulls which are being worked on. Perhaps micrometeorite shielding is more advanced on the OPs interplanetary spacecraft, making onboard gunfire safe, in a depressurization risk sense :) I'm not sure anyone, including the shooter, wants to be in a small, metal, possibly bulletproof can while firing off high velocity rounds. The more bulletproof you make the hull, the *less* you'd want to use guns inside. So I guess it's plausible that lower powered guns would be more popular, just to avoid ricochets. Finally, if you're about to be boarded, it'd be a smart idea to suit up beforehand. An assault tactic wouldn't be limited to bullets, it'd likely involve punching holes in the enemy vessel with cannon prior to boarding (just like old pirate ship battles, yarr!) [Answer] What you are looking for has been around a long time. Check out [Glaser Safety Slugs](https://en.wikipedia.org/wiki/Glaser_Safety_Slug). They were designed to not overpenetrate and > > The United States Federal Air Marshal Service tested and used the > Glaser Safety Slug extensively in the 1970s and 80s on board > commercial passenger aircraft to defend against hijackers. > > > The bullet design > > ... has a core of very tightly packed lead pellets. On impact, the > bullet fractures along manufactured stress lines in the > jacket—imparting all the bullet's energy very quickly rather than > over-penetrating a target or ricocheting on a miss. > > > [](https://i.stack.imgur.com/x7oXQ.png) They are also used in home defense weapons as they are not supposed to penetrate the home walls endangering someone in the next room. [Answer] The short answer is that if you are wearing armor which matches or exceeds the ability of the interior hull to resist punctures, then projectiles which use that characteristic to cause damage will be obsolete in proportion to the availability of that armor. Weak points with the armor are likely to be exploited, and these are likely to be combined with attempts to cripple the effectiveness of that armor. E.g. gases which are absorbed by skin, plasma bolts like the PPGs of Babylon 5, and short-range grapping. Here's some parallel thinking which might help the situation: To injure a human body, you need only penetrate it once. To minimize loss of air through a hull, you need to seal any punctures soon following their occurance. Perhaps railguns with miniascule slugs, a hull material that does not allow tears to propagate, and a special system that secretes sealant much like is used in some tires. Of course, and such sealant would need to harden very rapidly and have some method of delivery which was quite tolerant of the repeated perforation which you are administering to the hull of your vessel. If one would consider hull design as a possible answer to this question, then I would recommend 1. an inner covering of fluid epoxy which hardens in a thin, amorphous film on exposure to nitrogen or whatever comprises the air spaces in your vessels. The activating agent does not penetrate deep in to this tar. 2. a layer which supports the tar, allowing the projectile to penetrate rather than attempt to absorb or convert its energy — doing so might create progagating cracks which would create catastrophic failures, depending on how you built your pressure hull. This system would, of course, require diligent maintenance and repairs between and during battles. Please note that I do not take any of the following into consideration, as they were beyond the scope of my answer — granted, some of these concessions are more justifiable than others: * Why you would be shooting weapons onboard the ship, and not killing the crew from the outside e.g. by crippling the engines and life-support systems. * Whether the ballistics actually caused a path of airflow from the interior to the Void outside. * Whether the pressure hull would be integral with whatever system of micro-meteorite shielded existed on the outside. * The nature of the shielding and weight considerations. Keep in mind, however, that heavier armor makes for heavier ships, which makes them less maneuverable and more costly to fuel. Unless, of course, you were using some zero-point technology, but that is well beyond scope of question. * Where you'd put support systems, and how you'd be protecting or repairing those in the event of a ballistic casualty. This one is really an important, but not considered in the question. Remember, also, that even if you were using plasma bolts and chemical weapons to subdue invaders or crew, there's always the need to plan for explosive substances within the pressure hull. [Answer] I think any spaceship with a hull capable of surviving interstellar travel would have no problem surviving a tiny little anti-personnel bullet. So if you're going to have relativistic or FTL spaceships, I wouldn't worry about bullets penetrating the hull (though internal damage, like "oh man, the food replicator took a hit, hydroponics needs to work double shifts to keep us going" could make for good plot developments). Battle-hardened ships will have tough enough armor to survive ship-to-ship weapons. So, like FTL ships, they'll have little trouble with small-arms fire. Even a short-range, light-duty spaceship isn't going to suddenly explode just because someone put a little hole in the hull. Pirates and military ships will likely have spare metal and welding tools to repair the worst of the damage, and compressed air or solid materials that can be evaporated into a new atmosphere. All but the most hardened civilian spacecraft will likely be easy prey for pirates and military ships alike. Since firearms aren't going to help much anyways, they'll be generally prohibited for anyone except (maybe) security teams. Similar logic should apply to space stations. Civilian stations will be cheaper and more fragile, and firearms (or anything else that could punch holes in things) will be prohibited. Military stations, pirates, and corporate headquarters will tend to be hardened a lot more, allowing for more brutal, savage firefights without suffocating everyone on board. Of course, there will also be safety systems, like auto-sealing doors, vents, and ducts, that kick in when a room starts depressurizing, regardless of the type of ship/station involved. So small-scale firefights won't be the end of the story, even for civilian ships. [Answer] I don't think you solve this problem. If I'm attacking your people on your ship, then I'm already in a space suit. I just use a grenade or shaped charge and blow holes in your hull. Then, I go in and kill anybody (the few) who managed to get into a suit fast enough. Eject corpses, patch holes, re-air from the reserve air tanks that your ship has (possibly augmented with air from tanks I brought.) Any defense against bullets just causes your opponents to up the ante and use something more powerful. [Answer] One thing you're overlooking is that **you don't have to put a hole in someones armor to kill or wound** them - the impact of a standard rifle round is more than enough to break ribs, even if you're wearing a trauma plate. A .50 BMG or other heavy ammunition will probably outright kill you from the internal injuries, even if your armor somehow prevents the bullet from penetrating. The [frangible rounds](https://en.wikipedia.org/wiki/Glaser_Safety_Slug) that User2448131 mentioned are a good place to start. A large, slow, soft bullet will pack huge amounts of kinetic energy with limited penetrating power. Instead of punching holes in enemy armor, deliver rib-breaking, internal-organ rupturing concussive impacts to their bodies. **You have to remember that an armored suit still has soft, squshy meat on the inside**. Ironically, severely injuring your enemy without punching holes in them offers a lot of advantages. You can't pressure a dead man into giving up information, but you can pretty easily coax it out of someone with 13 broken ribs and a ruptured spleen by promising them medical attention. It also means you can have more elite soldiers, since they're more likely to be injured & incapacitated than outright killed. [Answer] Firearms are a pretty big risk on spaceships, but not because they're going to punch holes in the hull. A bullet-sized hole in your hull is the least of your problem in a situation where boarders have gotten on your ship, if it can get through an armored hull at all. In an ideal situation, each room has spare space-suits for those inside in case of emergency as well as your crew having their own space-suits so hull breaches are not that big of a deal. If you get in a combat situation, the first thing anyone's going to do is suit up. Venting atmosphere in a situation where your entire crew is wearing suits is annoying but not life-threatening. What's a lot more dangerous about firearms is that they produce heat and small explosions to propel their projectiles. Metal bullets also tend to spark when they hit other metal so firing guns as we know them is going to have an increased risk of fire (which is a BIG problem on a spaceship). Another consideration is ricochets. Spaceships are tiny cramped things, most of the time with corridors that are maybe 1 or 2 persons wide, depending on how important they are. If you fire a bullet in there and you miss, it's going to go all over the place. Best case scenario, it glances off a plate somewhere and embeds itself in a locker or something. Worst case scenario, your round shatters against something hard and you have shards of hot metal going everywhere. You might consider this to be a bonus as it makes your guns more lethal but remember that if you need to cross a bit of vacuum and there's a leak in your suit, you're going to have a bad time. Finally, there's recoil to consider. We all know newton's third law and in a zero-G or near zero-G situation, firing bullets does funny things. You shoot a gun while floating and the bullet's going to go one way and you're going to go the other way, making aiming in sustained firefights a bit of a hassle. Long story short: shooting firearms in a spaceship isn't a great idea but it's not immediately lethal if you miss. Depending on how ruthless you want to go, maybe boarding actions are fought mostly with melee weapons. Given that guns are problematic, maybe only the most hardened or crazy or high-tech crews use them. So most of the grunts that board ships show up with clubs, swords and other crazy shenanigans. If you want brutal close quarters combat, you can't do much better than high tech swords. [Answer] Assuming a hostile force is boarding your spacecraft, you probably have more issues than a few stray rounds going through the life support volume. The hull may well have been breached by the enemy spaceship overwhelming your ship's defences using high energy lasers, railguns, missiles and nuclear explosives, and then there are the holes punched in the hull so the Marines or boarding party can get inside (they will want to enter at multiple points to overwhelm your defenders). However, they are still trying to fight in a relatively confined 3D space, so there are some analogies to a current naval boarding party. The borders will need compact weapons capable of putting down a high amount of firepower if needed, so weapons similar to today's submachine guns and carabines will most likely be the primary weapons carried by the troops. Secondary weapons will be shotguns and grenade launchers, with pistols as close range backups. Boarders will also carry breaching charges and engineering tools to penetrate bulkheads to clear the entire ship. [](https://i.stack.imgur.com/B8bBX.jpg) *Royal Canadian Navy Boarding Party* [](https://i.stack.imgur.com/gCiWj.jpg) *MILCOR grenade launcher. Nothing like a lot of overwhelming firepower when you need it* Weapons will have to be different from the ones carried on Earth, since recoil forces will throw the shooters off if they're fighting in a 0 G environment, so expect large muzzle devices to redirect gasses and the stocks to be quite large to accommodate recoil compensation devices (imagine the working parts or the weapon in a cradle inside the stock). As for the damage to the ship's hull, using safety rounds and shotgun pellets will limit the damage, but consider that hulls will be much tougher than you think. Airplane hulls do not disintegrate under small arms fire, and inflatable structures like the [Bigelow](https://bigelowaerospace.com) space habitat module are made of multiple layers of Kevlar, so resemble a bulletproof vest more than a fabric balloon. A metal and composite spacecraft will probably be a reinforced structure like in the illustration to combine strength with light weight, so damage will not propagate through the hull. [](https://i.stack.imgur.com/CSkD3.png) If you look at sites which discuss space warfare, like [Atomic Rockets](http://www.projectrho.com/public_html/rocket/index.php) or [Tough SF](http://toughsf.blogspot.ca), you will see the speeds and energies being deployed make boarding rather unlikely. I might consider rethinking the action to something like customs agents or police boarding a docked spacecraft to make the setup work. [Answer] Shotguns. <https://en.wikipedia.org/wiki/Shotgun#Uses> > > The typical use of a shotgun is against small and fast moving targets, often while in the air. The spreading of the shot allows the user to point the shotgun close to the target, rather than having to aim precisely as in the case of a single projectile. The disadvantages of shot are limited range and limited penetration of the shot, which is why shotguns are used at short ranges, and typically against smaller targets. Larger shot sizes, up to the extreme case of the single projectile slug load, result in increased penetration, but at the expense of fewer projectiles and lower probability of hitting the target. > > Aside from the most common use against small, fast moving targets, the shotgun has several advantages when used against still targets. First, it has enormous stopping power at short range, more than nearly all handguns and many rifles. Though many believe the shotgun is a great firearm for inexperienced shooters, the truth is, at close range, the spread of shot is not very large at all, and competency in aiming is still required. A typical self-defense load of buckshot contains 8-27 large lead pellets, resulting in many wound tracks in the target. Also, unlike a fully jacketed rifle bullet, each pellet of shot is less likely to penetrate walls and hit bystanders.[2] It is favored by law enforcement for its low penetration and high stopping power. > > > > > In a space ship, the shotgun would have the following advantages: * Very high stopping power at the short ranges of an interior environment * Low potential to penetrate the hull of the ship * Low potential for friendly fire due to overpenetration, especially nice for the initial boarding process when friendlies greatly outnumber enemies * Small drone enemies that could be employed in a sci-fi setting will be easier to hit than with rifles or handguns, though this effect would be greater in a more open environment [Answer] Don't kill. Incapacitate. Rather than trying to penetrate the enemy's Armour, you fire [sticky foam,](https://en.wikipedia.org/wiki/Sticky_foam) either in a stream, or in large grenade like gelcaps at the target. You reduce their ability to move, gum up their weapons and the worst you'd need to handle the aftermath is the space janitor corps armed with solvents and whatever moplike thing you use in space. You can crack them out of their armour at leisure after you've left them to stew for a bit. [Answer] Chemical weapons that incapacitate humans but don’t breach the hull, maybe delivered by needlegun? Hulls thicker than any feasible armor? Aimbots that minimize the number of stray bullets? Self-repairing hulls or fast auto-repairs? [Answer] Assuming an advanced metallurgy culture a solution is to have small bullets, flechettes , or sprays that react violently with water. Think of type of **hyper-sodium** [(note how normal sodium reacts with water)](https://www.webelements.com/sodium/chemistry.html) **Projectile weapon:** A projectile that only explodes if hits H2O. Small hole (flechette) in hull may not be an immediate problem and could penetrate any armour. **Human target flame-thrower:** Generate high velocity shaped mist of reactive particles. People will burst into flames, but at the normal spaceship humidity levels the stream is not hot enough or projected long enough to damage equipment. Particle size and rate can be adjusted not to damage spaceship skin. Personal armour would need to be both all enveloping and quite tough. **Fluid based:** Seep through armour. But waterproof suit would block. Clearly this kind of weapon could be a problem if accidentally shoot the spaceship's water supply - but how much "bang" do you need to stop a person? and water does dampen kinetic energy effectively. [Answer] I had another idea - a gun that fires 2 dissimilar pellets that are connected by an explosive string. The pellets are fired in such a way that they spread out in the air and draw the explosive string taught between them. When this projectile hits an object, it wraps around it, in a similar way to a Bola. When the projectile wraps itself around a victim or object, the ends will curl around it, and the centrifugal force will make them whip around and hit the object with enough force to detonate a fuse which ignites the explosive string. It will do maximum damage to an object it wraps around, thus it shouldn't do a great deal of damage to walls or hull of the spaceship as it will hit the loosely. However, once wrapped around a person, it would wrap rightly around them, explode and should shred them, or at least crack their armour and shock them. [Answer] Just make your ship hulls out of a relatively soft metal like lead, but make it extremely thick. If your story's technology allows for high velocity armor piersing rounds which can penetrate *N* feet of hull, make your hulls 10 *N* feet thick. The softness of the hull walls should reduce richoettes while the thickness lessens the chance of leaks. [Answer] Why not just make the hull bulletproof? It probably has to be anyway to survive the super-high speed grains of space pebbles whizzing about... As to why they don't just make body armour out of the same stuff? Simple: it's too heavy or has to be too thick to wear. Even if they do, body armour has moving parts and therefore chinks. Or, the ship has an automated system that can quickly plug/patch small holes in the hull. [Answer] What about fixing the guns instead of the bullets? We have guns with cameras that you can hold the trigger down and they won't fire until an IR signature passes over the cross hairs. As long as the bullets don't over-penetrate, the ship should be safe. There's a little AI there, but not too much. [Answer] Explosive *ship* decompression from bullets isn't really a thing to worry about as it is more mythological than actual. So really that brings you to how "real" you want your physics to be? The existence of body armor on a spaceship in a world where this was even semi-common would preclude pressure as a problem for most cases. Crew armor would include by design a pressure suit. Passengers would likely travel in emergency pressure suits - which don't have to be big and bulky for short term use - or have them handy. So the crew on a ship about to get boarded could conceivably suit up and *intentionally* depressurize before the actual boarding. They wouldn't have to fully depressurize either. A 50% level (compared to Earth standard) would require suiting up with a minimal pressure suit and air supply, and would greatly extend the time to fully decompress. There would also be tactical reasons to decompress a ship prior to getting boarded. If the defenders know the ship well and can jam radio communications they force the invaders into a sensory tactical disadvantage. Fighting without auditory feedback on your environment is really difficult without specific and intense training, let alone squad communication. A good review of the math behind it can be found at [this page on spacecraft decompression](http://www.geoffreylandis.com/higgins.html), but the "one-one-ten-hundred" rule of thumb can help in estimating it. That rule is as follows: "A one square-centimeter hole in a one cubic-meter volume will cause the pressure to drop by a factor of ten in roughly a hundred seconds." As far as reducing the risk of bullets w/o body armor, look no further than "Dune". There you have the fictional "Holtzman Shield" - a field of energy that slows down or only allows slow moving objects through. If you take a step back from the personal-sized ones in Dune, the idea could be used on a multi-hulled spaceship to minimize the risk of gunfire. Your world may not have compact enough power sources to power such a device as body armor, but a ship could, thus removing it from being effective body armor. Though of note, I seem to recall in the original Dune movie during the invasion a bullet penetrating the shield and killing the wearer. You could also play off the idea of slowing the projectiles down enough that they can't penetrate the ship hull, but not powerful enough to slow them down far enough to avoid penetrating flesh. On a personal side, I would drop the expectation that anything but a very high amount of small projectiles or a small amount of large ones would produce catastrophic events during the boarding battles. Unless mass is a non-factor in your world, even boarding troops would not necessarily be firing willy-nilly because that represents mass that had to be carried and thus ammo itself may be at a premium. Perhaps it used to be that melee was the normal way because of the mass of guns and ammo versus, say, a cutlass or brass knuckles. But now with more advances in propulsion tech mass is less of an issue and guns are making their appearance and are being "disruptive". But either way, those are at least some ideas on how to solve the problem. If you want to be more "hard sci-fi" then that solves your problem for you because bullets are not the threat Hollywood likes to make them into and projectile ammunition is a mass penalty anyway. Otherwise, the "softer the sci-fi" the more flexibility you have to play with things like energy dampening fields that can't be powered by "man-portable" power supplies. I also think you could get more mileage by dedicating thought to how ship design might evolve considering boarding actions and playing with those. [Answer] ## Combat. In. Space. (Impressive echos trail off) Using outer space as an environment for combat scenes has unique challenges as it is a unique setting that (so far) very few humans have experienced. The common challenges are: Lighting conditions, Temperature conditions, Pressure conditions, Radiation conditions, Mass Proximity and Collisions. **Lighting Conditions** Outer space is typically either very dark, or very bright. As no human has been much further than our own moon, we really don't know how bright or dark true interstellar space is, however, close to our primary, it is quite bright, given that our star is a relatively young one. Visual protection against direct radiant exposure to the sun is important. **Temperature Conditions** It's cold out there. Unless one is directly exposed to the sun's radiant energy, in which case it can be lethally hot. A temperature controlled environment is critical. **Pressure Conditions** Specifically, the lack of pressure. Most of space is a near vacuum. Humans are used to "one atmosphere" of pretty constant pressure. Protection against the lack of pressure is a must. **Radiation Conditions** The sun puts out a lot more than light. Any time one is near a sun (or some planets) one must take into consideration the other types of energy the star is putting out, and protect oneself from it. **Mass Proximity and Collisions** Space may be big, but it's not empty. And there is no speed limit below light, either. Bits of dust or pebbles moving along at even a fraction of light speed can punch holes into, through, or effectively explode just about anything. Armor is a big plus. Sufficient mass will produce gravity gradients of strengths dependent upon the amount of mass in close proximity. Large enough masses will produce a "gravity well" which can be handy for orbiting, but not so handy for plummeting. However, when one is not near a mass, zero-g conditions provide unique challenges and effects which challenge a lot of assumptions. ## Spaceship, Starship, and Station Systems The hulls, viewports, and airlocks all take into consideration the above required protections and conditions. The internal structure will also likely be compartmentalized such that even if one section receives damage, other sections can function independently. Internal systems should also be designed to handle acceleration stresses, accidental impacts, decompression, and spills. In fact, one of the greatest challenges to environment-containing objects in space is liquids and fire in zero-g conditions. Liquids scatter and spread based on momentum and surface tension. Without gravity to provide a unifying direction, liquids can scatter quickly and unpredictably, spread into nooks and crannies that would be impossible in a gravity well, and is very difficult to clean up. Fires expand globally from the ignition source, and follows the oxygen and/or hydrogen, leaving behind pockets or streams of 'dead' air where no one can breath. While this can also put out fires, it is potentially very dangerous. Even a human can knock themselves out with CO2 poisoning simply by breathing long enough in an area with little to no air current and not moving around. Fire suppression systems such as we have on Earth cannot work in space, as they usually depend on releasing water, foam, or dust into the atmosphere; all three of which depend on gravity to function as expected, and would create more hazards and cleanup than they would solve. Without gravity, fire suppression materials would drift, clump, and clog everything nearby, and eventually get into other compartments, not to mention posing a real breathing risk to any humans on board. ## Combat Due to all the above factors, standard gravity-well weapons would tend to cause undesirable problems for any potential hostiles in a zero-g environment. Most weapons of today rely upon blunt force trauma, explosive force, chemical reactions, and cutting or piercing. **Melee** Melee weapons (up close and personal) typically rely upon cutting, piercing, or blunt force trauma in order to inflict potentially painful and crippling wounds upon opponents. However, such wounds cause bleeding, as well as potential for messy bits flying around the compartment. If recovery of the vessel or station being boarded is not a priority, then this is still a viable option... except for one thing. In a zero-g environment, there is no gravity and little to no friction to brace against during the swing. Martial arts likewise suffer from the lack of gravity. Once one has swung or punched, one will continue in the direction of the swing or punch, unless one actually connects and hits the target. Once you've hit the target, however, you will now find yourself moving away from the point of impact. One possible solution is to artificially provide gripping and bracing points with handles, narrow corridors, as well as magnetic and velcro grip surfaces. Another downside to melee combat is the potential for breathing in flying messing bits, and the shorting out or damage to equipment and controls. **Ranged** Projectiles have additional issues in zero-g areas. Chemical projectiles spray residue (dust, oil, bits and shards of metal or plastic, etc.,) all over the place with all the risks that entails. Projectiles are typically moving at higher velocities than thrown or accidentally bumped objects, and can ricochet with disastrous effects. **Explosive and Chemical** Explosions will create over-pressure ripples in the atmosphere, which can be damaging all by itself, not to mention what it does to solid surfaces. If flechette materials are included this sort of attack could be devastating in outer space. Unless one is going for a quick and messy entry, these sorts of weapons are not usually good options in melee combat. Chemical weapons may be potentially effective - introducing something to the air or water supply can certainly get rid of opposition, however it will not usually yield exciting battle sequences, unless protection is had on both sides. ## Viable Options After all of these negatives, there would seem to be very little one could use, especially if preserving the ship and/or station functions is desired. However, there are a few: **Puffer weapons** These are weapons which release a small contained puff of highly inflictive gas, which in concentration will be effective, but will thin out and become ineffective in fairly short order, so as to avoid the wielder also being affected. Mostly used by suited attackers against unsuited victims. An injection variant for use against space suited individuals, with optional cauterizing and poison mods is also popular. **Zapper weapons** Zappers are designed to either overload powered suits, or to pierce both softer suits and the person within, and producing enough electricity to incapacitate the victim and cauterize the would instantly, preventing (hopefully) pesky droplets of blood from getting out into the atmosphere. **Sonic weapons** Weapons which assault the auditory senses, these weapons can be effective even when transmitted through metal surfaces. It can impede thinking, and shake morale, as well as become extremely painful "Ride of the Valkyries" cranked up to 31 is a traditional, yet still popular, choice. For maximum effectiveness against suited individuals, direct contact is required. **Incapacitation weapons** These weapons are designed to pin opponents in place. A simple extendable brace can be used to pin someone face first into a flat surface, though this is typically hard to do in the middle of combat, especially if someone gets tossed and knocks your brace loose. Magnetizing an opponent can also pin them into place, so long as they can't reach the device's controls. Restraints are also a popular choice, though this usually requires a victim who has been rendered unconscious or helpless already. Skilled grapplers might be able to snag a limb mid-combat and cuff it to a nearby handle or grip, one by one. Chemical restraints of a quick-set, high viscosity, and high surface tension nature are less common, but still effective in a quick and dirty way. Emphasis on the dirty. Clean up is a horror, but if your goal is to simply pin them down fast and move on, there is a place for these in your zero-g arsenal. ## Conclusion Combat in space requires some clever thought, a sneaky temperament, and a billard master's grasp of angles, vectors, and velocities; applied to 3D. With some planning and cunning technologists, your narrative space pirates will be terrorizing the space lanes in no time at all. [Answer] **The only way to win the arms (armor?) race is not to play. Don't try to armor your ships against standard bullets**. This does things to the armor market that work in your favor. The first thing to understand is that **most people won't want to wear armor anyway, and most armor-users will want to wear thin, flexible armor that can be easily concealed**. Against the first group, "safety rounds" that can't pierce a ship's hull will be as effective as ever. But **even against people wearing concealable armor, safety rounds will still hurt like hell even though they may not be lethal, and thus are effective as stunning weapons**. The few moments a lightly-armored opponent spends stunned from the pain is enough time for an assailant to pull out some other tool. Of course, heavier, rigid armor that could truly stop a safety round can be made, but it will be conspicuous. Especially since bullets that can pierce such armor can also pierce a ship's hull, so the market will demand that such armor also be able to function as a pressure suit. So **when a ship's surveillance cameras or crew notice someone clanking around, the people defending the ship know that they may need to pull their "elephant guns"** (i.e. what we'd call "standard" rounds). Despite the name, an elephant gun might not be a distinct gun, but just a clip of hull-piercing ammunition that fits in the character's usual firearm. As a result, **gunfighters in a universe like this carry one or two guns, and a couple of tools**: * "The usual gun", loaded with safety rounds * An "elephant gun" loaded with standard rounds (or a clip of standard rounds for the usual gun) * A "stake": a stiletto made from some suitably strong material to punch through light armor or joints in heavy armor (for those times when the elephant gun just isn't an option). Maybe paired with a hammer for dealing with really tough armor. This is more of a tool for finishing off downed opponents than a weapon *per se*, though stake-fighting could develop into a kind of martial art in its own right. * "Cuffs": Some kind of restraining device. Could be literal handcuffs, or maybe some sort of force field or tranquilizer. For those times when you need to make sure someone isn't getting up again, but killing them isn't an option. This should, in theory, give you the kind of environment you're looking for. Lethal gunfights, with the added brutality of *staking* downed opponents at times. Reasonable safety on a shipwide scale, *most* of the time, but with the possibility for things to "get dangerous" when the elephant guns come out. [Answer] As far as I remember it was in the book "Solar Station" from [Andreas Eschbach](https://en.wikipedia.org/wiki/Andreas_Eschbach) where the walls of the station were filled with a kind of foam which, when the wall was penetrated by a buttet or micro asteroid, closed the leak within seconds. Of course this only works if the holes your weapons punch into the walls won't be too big. [Answer] While the Earth's early, short term ships didn't have much radiation or micrometeorite protection, any long term ship has to protect its crew from hard radiation and micrometeorites. [Current micrometeorite protection](http://www.esa.int/spaceinimages/Images/2014/06/ATV_shielding_after_impact_test) stops a 7.5mm aluminium projectile at 7km/s. That's of the order of a hundred times more energy than a bullet, though obviously if fired from the inside a bullet hits the pressure hull first rather than the shielding. Penetration depth of bullets is less than the penetration depth of hard radiation in most materials, including water which is the most likely near-future shielding. So a realistic ship might have a thin inner hull, a couple of meters of 'water' or ice for rad shield and crew use, then a micrometeorite shield. A bullet will penetrate the inner hull, but stop in the water after 30cm or so. Even without the water it would be stopped by the shielding. The water won't be very pressurised, so expect a bang and maybe a little splashing. Pseudo-gravity from centrifugal effects would mean the water would stay put; microgravity would mean the water might bubble out a bit where the bullet displaced it. If bullets can penetrate the hull of your spaceship then all your crew are already dead on a long term mission. By 'water' the load may get replaced with waste products as used, so the splash may be somewhat unpleasant. [Answer] I think you can incorporate a style of energy weapon. I agree that lasers don't sound promising, but more of a plasma/electric type of ammunition could be an appropriate tool if one is open to such an approach. In this scenario the hull has a lot of mass, and can disperse large amounts of energy blasting into it without issue. Just taking the same material and creating an armor plate wouldn't work, as the energy needs to dissipate *somewhere*. If shot in the chest it would just ark from the plate through their legs and into the floor. They could get a full-body suite beefy enough to route some of it to the hull -- if the floor is even the right material. But the conductivity wouldn't be ideal so damage wouldn't be eliminated, and the encumbrance penalties would be significant. That is, they'd have textbook heavy armor. [Answer] I'm thinking... for what purpose would you board an enemy spaceship? I can only think of 3 options... 1. To capture people on board. 2. To capture the spaceship 3. Data gathering from the spaceship itself As far as I can see, all three options rely on the spaceship being pretty much intact. Option 1, you can't harm the spaceship in case it depressurizes and the people die. Option 2, no point in harming the spaceship heavily, although you may disable it's power to make it easier to take over. Option 3, the more you damage the spaceship, the more likely you are to destroy data on it. Therefore if I was going to board a spaceship, in the best case I'd disable it's power, so it can't move and can't fight back, then if possible I'd pump sleeping gas into it, depending how big it is, and then enter the ship with gas masks on. If that's possible, it's easy, but otherwise there's a range of weapons I could use on the enemy, and depending on circumstances, some wouldn't even require an entry to the ship: ie, the attacking spaceship could use them from outside the ship. I could use: 1. Taser Shockwave - idea of electrocuting lots of targets with a single wave 2. Radar targeted laser guns - whatever armour the enemy has, they will still be able to see. Use a short range radar to target their eyes with a laser and temporarily blind them. 3. Active Denial System - radar waves that causes intense pain 4. Vomit Gun - use of pulsing lights to make the victim vomit 5. Water jet - powerful enough to knock a human over or stun them, this wouldn't penetrate metal. 6. Flame thrower - no practical armour is really proof against high levels of concentrated, sustained heat. Most of these should work with armour, if the victims are unarmoured, the job becomes a lot easier, I can use tasers, electric swords, close combat stuff. Maybe the use of droids etc can target the ship's systems itself as well. Note that all these things can be used by those being attacked, in defense. In addition, it probably makes no odds to the victims if they can blow apart the attacking spaceship. just my 2cents, it's an interesting question! [Answer] (You don't say what kind of physics might be acceptable, but it appears that things like energy weapons are plausible *some*where in your universe, suggesting exotic physics) "But just build a body armor out of it, and you’re bulletproof" and similar arguments in answers can perhaps be worked around. The ship is much *much* larger than a crew member / combatant; if the hull shielding incorporates some sort of active dispersal (whatever kind of "field" physics makes sense in your world) which spreads the kinetic energy of a small impact across the entire area/volume/mass of the hull material (and possibly an additional mass sink somewhere in the ship) it would take an inordinate amount of energy to even scratch the hull - but a combatant suit with comparable technology could only spread the impact over its own area, very much tipping the balance. Whipple shield 2.0, needs a catchier name. (The same technology is likely to be rather useful for attacks from outside the ship, too, although ship-to-ship combat and breaching forces may use much larger kinetic energies, and perhaps energy weapons there aren't excluded from your scenario.) [Answer] One more or less realistic solution is to use a [laser gun](http://englishrussia.com/2013/10/05/laser-gun-for-a-soviet-cosmonaut/). [](https://i.stack.imgur.com/xNATr.jpg) Allegedly, a prototype of a laser gun was developed in scope of the Soviet space program for military purposes (the Polyus space station). [Answer] I think the easiest is a highly advanced non-Newtonian fluid armour in the ship. From [this](https://www.youtube.com/watch?v=D_xx_Lj_NuQ) video, a giant gummy bear stops a bullet and a gummy bear is a kind of non-Newtonian fluid. This armour running behind the inner panels and outer armour ought to prevent kinetic slugs punching through the hull. This layer could be quite thin, and potentially serve other functions (conduct electricity around the ship). It would also add to the carnage as it now becomes ship 'blood'. [Answer] Since internal ballistics of any kind (from, say, an explosion internally) are bad, why not have [whipple shielding](https://en.wikipedia.org/wiki/Whipple_shield) on both the inside and outside of the outer hull? This is essentially spaceship Kevlar (very dumbed down description, read the wiki article). It is put on the exterior of spaceships to help reduce and prevent damage from debris and micrometeorites by absorbing and redirecting the kinetic energy from the impact before it reaches the primary hull (often shredding debris and making it effectively harmless). Make the outer hull also have this design on the inside (perhaps only in exposed corridors where explosions or boarding actions might take place to save weight/space). Effective whipple shields against bullets would be too heavy/bulky to wear individually (though, there is probably *something* better at keeping a person alive against small arms fire than a whipple shield in your universe). That said, why would a boarder care about putting holes in an enemy ship? Presumably they would be in some kind of armor/suit to protect them from the environment. There's no guarantee that the enemy vessel will have an intact hull (as most boarding actions happen after/during a battle). If anything, depressurizing the entire ship would help the boarders take control of it, and any holes can be fixed after the battle. [Answer] In [Seveneves](https://en.wikipedia.org/wiki/Seveneves) ( which is a super enjoyable book and well worth reading ) the necessity of not making holes in spacecraft results in the development of catapult based weapons. These don't fire far, but they don't need to in the constrained area of spacial habitats. What makes them interesting is that instead of regular projectiles, they fire small anti-personnel robots, that may attack the moment they land on a target, or crawl around the target looking for a chink in their armour. Consequently arms races develop in defensive and offensive robotics as much as in the weapons to launch them. [Answer] It depends on what your assailants goal is. If they want to capture the ship in working order and those on the ship presumably want to repel the attack while maintaining the ship they both have the same limiter on weapons. If the assailants want to destroy the ship and are close enough to board they may just use explosives rather than precision firearms. I think the major reason fiction often talks about firearms in space ships as a catastrophic situation is as a device. It's often more interesting when you are forced not to use firearms, or it's an easy way to build threat when a gun does more than just shoot someone. Many people who already posted have good solutions for ultimately using firearms anyway. Depending on the story you are writing do what is most interesting and come up with a justification that fits your world. Could also go the Dune route and say firearms left favor and have their resurgence be a tactical coo for one force. [Answer] Super bouncy balls...fired from an automatic air canon at incredibly high speed. They will hurt and continue as a distraction long after they are fired. If you use the ones that have a strobing LED inside it will be psychedelic! OK, not very realistic but illustrates a point. Seriously though... Basically anything big and slow transferring a lot of energy will do the trick. It won't be very effective on anything hard, like the hull of a ship, but launch something hard enough and the human body just isn't strong enough to prevent dislocated joints and broken bones. Another possible non-penetrating option would be something like from the animated movie *[The Incredibles](https://en.wikipedia.org/wiki/The_Incredibles)*. [Sticky balls](https://www.youtube.com/watch?v=dK_OKGELcn0) that expand are fired at the target(s). If they are very difficult to get off they become a distraction and then a disabler. If you want to be truly diabolical, mix in a skin irritant that becomes a true distraction! ]

[Question] [ The idea of a truly masterful swordsman capable of taking on dozens of average swordsmen by himself (sometimes even above average!) is a pretty common depiction in fantasy media. A recent example I can think of is Barristan Selmy from A Song of Ice and Fire, who supposedly could have taken on a room full of elite swordsmen by himself. Realistically, though, such a thing is certainly not possible. Clearly, some changes would need to be made to human physiology in order for the Medieval world to resemble our own while still being sufficiently different enough to enable this concept. I propose two changes: * Make 'reaction time' a muscle that can be trained just like any other * The rate at which muscles expand while growing stronger is halved (more compact muscles, less energy requirements, but still stronger) **Would the realistic results of these two changes enable classical Medieval combat to more closely resemble the 'Master Swordsman' fantasy exemplified earlier?** [Answer] **Tactics Matter** Forget the "Surrounded and outnumbered" scenario. You can survive being outnumbered, but not surrounded. This means where you choose to stand and fight is as important as your skill in fighting. A narrow hallway, bridge, or similar bottleneck will mean you only face one or two at a time instead of many. This is historically how famed swordsmen and legendary last stands were able to work. I'm not trying to downplay the famous last stands from history where small numbers or even single men held off crazy odds, but the ground they chose meant that really they only faced even or at least close to even odds at any given point during the fight. **Stamina IS important, But it doesn't make up for numbers** Ever notice a recurring scene in movie sword fights how either only one or two bad-guys attack at once, or all 10 bad guys attack *perfectly in unison?* Like, six swords all come in at exactly the same moment at the same angle and he blocks all of them at once? That's not how fighting works, that's how *choreography* works. You can be strong and you can have endurance and it is important that you do, but it doesn't matter. If a dozen people want to kill you you aren't going to outlast them because there aren't any Hollywood laws saying they all have to come at you at the same time or only in onsies and twosies. You aren't fast enough to block a sword coming at your neck, one coming at your groin, one coming at your back while two guys try to tackle you and another one kicks sand at your face. The exception to the above for the "one at a time rule" is if you are a samurai, there are stories of fighters agreeing to fight a single warrior only one at a time out of a sense of honor. Haven't ever read any from anywhere else and even then these kinda fall more into the side of legend than verifiable fact. **Psychological Factor** Defeating a group of men doesn't have to mean outright killing all of them. Again, this falls into the legend vs history side of things, but a man named Jeremiah Johnson was engaged in hand to hand knife and tomahawk fighting with the Crow Indians when he became severely outnumbered. Supposedly he removed the liver from a fallen brave and proceeded to start eating it in front of them causing them all to run in revulsion and fear. In a much more historically verifiable act of psychological domination the vikings who landed in america to found a colony were horrifically overrun when a female viking picked up a sword and began to go howling mad berserk. This shocked the apparently more patriarchal natives and caused them to fall back long enough for the surviving viking colonists to fall back to the longboats. (In retrospect, I don't know why so many of these stories are against the Native Americans.) In the Falklands war a company of British royal marines encountered a much much larger force of Argentine army. The Argentine commander demanded that the British commander speak to him about surrender, the ever plucky royal Marine Responded "We will accept your surrender." The Argentine commander felt that if the brit was so cocky he must have a much larger force and agreed to disarm his men... where he found his force of several thousand being held captive by a force of just over two hundred. In WW1 A US serviceman was trapped behind enemy lines where he utilized hunting calls from his mouth to trick German soldiers into putting their heads up or just to disorient and frighten them. After he psychologically harassed and killed several dozen of them over the course for a few days they surrendered to him just so he would go away and stop killing/tormenting them. He was using turkey and deer calls made by his mouth, which they had never heard before and found terrifying, especially since the noises were usually followed by accurate weapons fire. Point being, many times in history single men or outnumbered men (and women, don't forget that viking lady) have used a psychological edge to fend off much much larger forces. **In Summary** For a realistic scenario you have your swordsman. He *is* an excellent swordsman, legendary in fact. Hes is faced by a large number of enemies, and they know his reputation well. They attack him a few times, but he is positioned on a narrow footbridge or in a narrow hallway or something. He manages to kill several of them. Not all, but several. The remainder, knowing his reputation and seeing his work are already not feeling too great about continuing this game, when their leader receives a grievous and brutal wound. He is screaming very loudly and piteously, the lone hero is laughing and jeering them on, and these guys have had enough. "Screw it, we don't get paid enough to deal with this" they think, and run away. HE has killed six of the two dozen or so of them, and grievously mutilated/wounded the leader. He runs away in the opposite direction to find a new pair of pants. Somebody saw this, or at least actually believed him and told somebody else. Whom told somebody else, whom told a bard, whom wrote a song or poem. Its now been 50 years and the legend of Sir Chad who slew 40 men alone are repeated for the next 500 years in various stories, legends, and tales. Eventually Hollywood decides to make a really cheesy action scene out of it involving a lot more choreography, dying bad guys, and witty one liners and less pants soiling. [Answer] # You don't need stronger muscles, you just need fear The difference in strength between the strongest and average human is really not that important in the scheme of things. Especially in sword fighting, even the most compact muscles can easily be punctured by a blade. In a room full of swordsmen, a lucky strike can shear through to bone, and then the master swordsman is done. On the other hand, remember that scene from [*Unforgiven*](https://www.youtube.com/watch?v=1AVpaOuE1Pg)? You might say it is patently impossible for one man to kill 7 in a shootout without being hit back. But that is explicitly discussed in the movie. Kill the leader first, keep up the attack, rely on fear and a bit of luck. Using swords and wearing armor makes this even more possible. Strikes from a fearful arm lead to glancing blows. The intimidation factor of the man next to you being shot is nothing compared to the man next to you erupting in a fountain of blood as someone cuts his torso nearly in half, etc. [Answer] # A plausible no-magic scenario In one corner we have “the hero”. He is truly excellent with his sword, though not immortal. What he does have is practice dealing with several opponents at once. In the other corner we have six bandits. They are by no means unskilled, even if each one would lose a fair fight one-on-one with the hero. They, on the other hand, have not trained how to fight six against one effectively. (Why should they. Who loses six-against one? In such situations, the opponent just gives up, pledging for mercy right?) The hero is lucky in one aspect. The ground is flat. As long as his back is clear he is free to move about. He will not become cornered. The fighting starts. Six bandits rush against the hero. The hero does not fight all six. He backs and steps left getting out of the way of most of them, parries, ripostes and cuts one bandit badly. Another swing while the bandits are confused, six opponents has become four and the hero backs away quickly. By now the bandits have realized that the opponent is dangerous. They try to spread out, but since they are not coordinated, the hero manages to move about so that he never faces more than one at a time. One bandit hesitates, the hero attacks and it’s three to one. This is where mind game takes over. A determined, coordinated attack by three would still mean the end of our hero, but while all three bandits are willing to move around the hero to cut him down from behind, none of them wants to be the one keeping him occupied head on. Maybe they run away, maybe this indetermination causes the end of one more. Fight is over. Why did the hero win? He was prepared, bandits were not. If two men had attacked him head on at the beginning while the rest flanked him from both sides, he would be dead meat. Also he had no choice but to fight full out to survive while each bandit could hope that one of the others took the lead (and risk). Would it work every time? Hell no. But a hero is allowed to be a bit lucky. [Answer] Looks like I'm late to the party but – hello! **I'm a former nationally ranked saber fencer and a coach of many years.** ## It turns out that it's actually \*easier\* to fight many swordspeople at once than individually. In my (anecdotal) experience, there's nothing unrealistic about your scenario! If there's even a mild difference in the skill levels between the one and the many, this is very reasonable. When I was teaching at the college club level, after my students had had a few hard days of training, I'd add in a game day for them. Nothing like how fencing actually works in competition, just fun activities to make them feel like swashbucklers. Most often it would take the form of dividing them into teams and letting them fight it out melee-style, but occasionally they would convince me to do a many-on-one type game with me against all of my students. These classes could be up to a dozen, dozen and a half students, so it wouldn't be out of the ordinary for me to be taking on 15 people. I won almost every time. I'd like to take credit for that, but in fact, very little of it had to do with the raw skill differential. In a one vs many engagement, if the one keeps moving, the many will end up getting in each other's way. The one is unconstrained in their movement, while someone in the group will have less freedom of movement, on average, because of all the other people pressing around them. As any swordsperson will tell you, if you're not able to move around freely, your opponent will get the better of you 9 times out of 10. The key is this: **the group interferes with itself, so even above average fencers will be at a disadvantage against a single competent opponent**. I know it seems counterintuitive, but I see it over and over again. You don't have to take my word for it, though. Here's video from a while ago that might be informative, wherein 3 olympic fencers take on 50 opponents at once: <https://youtu.be/PgKg0Hc7YIA> Yes, it's a contrived example, but the principles remain the same. You'll note, the experienced fencers don't start getting knocked out until they're fencing more or less one on one. [Answer] Let's consider something more reasonable. **A heavily armoured knight taking on half a dozen ordinary infantrymen** He's probably got a decent chance here, he's a professional soldier, an ordinary infantryman is a peasant with a pointy stick. This is no meeting of equals, it's someone whose sole purpose in life is to train to kill people better versus a group of farm boys who wanted to see a bit of the world before going home and that's if they were volunteers rather than conscripts. Of course the telling of the tale in the bar afterwards, there were more of them, a couple of drinks down the line and they were bigger, by the end of the night they were also elite knights. *And so legends are born.* As good as he may be, no one man is going to be taking on a room full of "elite" swordsmen. His blade can only be in one place at a time and their blades will be in many places. Even if he can defend against them all, he will fall from exhaustion before he can despatch them. [Answer] There are some good answers here, especially the fear factor. However one aspect that has not yet been touched on is *technology*. However you cut it, one swordsman against many is a highly risky proposition that you wouldn't expect to work more than once or twice. But give that swordsman greatly superior equipment, and it becomes more likely. Imagine being a bronze-age skirmisher coming up against an armoured knight wielding a steel blade: your spear/dagger can barely hold an edge, while he's cutting through your cohorts like butter and every blow they manage to land seems to bounce right off. Even a group of expert warriors would think twice. [Answer] ## It is indeed realistic, mainly because most humans fear death, and it probably happened plenty of times in history. We can't really take sport fencing or computer game mechanics as a basis. If they were fighting with training gear fully protected, or if they were mindless drones where the master swordsman differed only in physical strength and slightly better reflexes, then yes, even just 2 or 3 lesser skilled opponents would have a great chance of defeating a single more skilled opponent. First, let's assume the fight doesn't start with the master surrounded, because that would reduce his chances enormously. One of the most important factors would be how the fight starts. Most people don't realize instantly that the situation is a life-or-death one, and they will lose precious seconds in the confusion. ### 1. Most people lack the mindset and the intent to kill There was a [research](https://www.youtube.com/watch?v=zViyZGmBhvs) shortly after World War 2 which showed that a huge percentage of soldiers were not even firing into the direction of the enemy, and even those who fired, very few of them were aiming at individual soldiers, most were just firing wildly in the general direction of the enemy. If the opponents are just soldiers pressed into service, or they are bandits fighting for loot instead of a cause which would motivate them to kill and to risk being killed, it would look like most bar brawls are: they are more into scaring their opponents away or dominating them, than outright killing them. ### 2. Most people fear death Those of you who ever sparred, practiced sport fencing, or just LARP, would you go into the fight with the same eagerness if you knew it was to the death? Probably all of you were hit at least once during practice. Imagine it was deadly. Technically, if several less skilled swordsmen lounged forwards at the exact same time, one would be surely killed by the lone master, but the others would manage to kill him in return. But are they coordinated that well? Probably not. And who is the one who wants to sacrifice his life to go first? Especially if the attackers are bandits, who don't fight to protect their loved ones, so they don't have anything to sacrifice their lives for... Probably, as the fight starts, [everyone expects someone else to strike first](https://en.wikipedia.org/wiki/Bystander_effect), and a precious few seconds will pass during this time of indecision. There can be at most 4 or 5 in the front facing the master directly (any more and they would just get in each other's way), the rest would be behind them. Now as they wait for someone else to strike first, the master swordsman quickly finds the one or two whose guard is the most vulnerable, and stabs them before they can react. They don't fall to the ground like sacks of potatoes, like you can see in movies or video games. They will writhe violently on the ground, screaming in agony at the top of their lungs, with blood spattering around. Some would vomit at that sight, some would run away, and many of the rest would be frozen for a short moment, allowing the master swordsman to strike again. At this point those who are still uninjured, would probably fear for their lives and just wildly flail around with their weapons, not really eager to close the distance. They will be uncoordinated, allowing the master swordsman to engage them one or two at a time. ### 4. Fight-or-flight reflex. It takes a **lot** of training to overcome basic instinct. If the fighters are just averagely trained, in a life or death situation it can happen that all their training and all their techniques go completely out, and they are back at basic animal instincts. ### 5. Armor. This is what makes a great difference, especially when combined with the fight-or-flight reflex mentioned above. Fighting against armor with a sword requires very elaborate techniques and great precision to stab at the more vulnerable spots of the armor, and there are complex techniques for getting into a position to be able to perform those movements. You can't defeat metal armor by just wildly hacking at it with a sword. If the fighters revert to basic instinct, they will not be doing much damage against someone who wears armor. If the master swordsman is really well trained, his mind will not be affected, and he will still be able to perform the techniques needed to defeat his opponents even if they wear the same quality of armor. ### 6. Coordination Even if the attackers are individually not too bad at fighting, they might lack the skills and the practice of fighting in a coordinated way, and they might just get in each other's way. Here is a great video demonstrating many of the issues mentioned above: <https://www.youtube.com/watch?v=7s7KfetTixQ> [Answer] All else being equal the equipment of a true professional knight gives them an enormous advantage over rank and file soldiers who were the medieval equivalent of modern [territorial soldiers](https://en.wikipedia.org/wiki/Territorial_Force); farmers pulled from the plow, given minimal training and second rate gear if they were lucky. Full plate armoured knights were seriously hard to damage even for fellow fully armed and armoured opponents. Added to that you have training; the real masters trained to a very specific degree, as much as they could without damaging themselves, from as early as they could without damaging themselves, as continuously as they could without damaging themselves, for as many years as they could keep it up without damaging themselves. On top of that you will always have a few statistical freaks who can out perform most of their peers at a given task. If you combine the effects of exceptional natural talent with highly effective training that starts at 5 or 6 years of age you get a 20 something year old knight who, while in their prime, can take on anything you throw at them. Add to that the money to get the best custom equipment and they're more than a match for other knights, and a lawn mower when it comes to conscripted farmer-soldiers. There won't be many of these people around in any given place at any given time (maybe 1 in 100 knights perhaps 1 in 10,000, maybe less, combatants in a major battle) but you would *not* want to cross blades with one of few who were. Sorry to answer your actual question: * yes if you increase maximum performance for strength, stamina (very important in battles less so in tournament matches), and reaction times for the very best combatants you will get a sharper, scarier, peak when it comes to best performance and slightly increase the incidence of "above average" fighters. Making the absolute best fighters swift death to everyone else and creating a larger elite pool for them to be measured against. So instead of the "best of the best" being 1 in 100 knight they'll be 1 in 10,000 with another 500-1000 in ever 10,000 knights who are the "best of the rest" being as good as the very best would otherwise be. [Answer] The main problem is not reaction time nor the time to grow muscle. The main problem is that swinging a sword around is an heavy job, and the stamina one has is limited. It doesn't take long before one side is puffing and panting, and that usually mean death for that side. In a one to many combat scenario, the one can at best take down one, maybe two opponents, but then will be simply left out of fuel, and spitting a watermelon seed on his forehead will take him down (well, not literally). I think the most realistic way to go in the direction you want to go is to improve stamina and endurance. Kind of a marathon training. And still it might be better to use that training for fleeing and not for fighting. [Answer] There are some real historical techniques to deal with multiple enemies, you can look up the "Montante" or "Spadone" sword school in historical european martial arts (HEMA). The Montante is a way larger than normal sword used in the iberic countries that is simmilar to "Zweihanders" or "Claymores", that were used in late medieval and renassance times. Their techniques involve dealing with a higher amount of enemies and even protecting others while doing that. About the fear factor that was pointed in other answers: there are accounts of giant sword users like Pier Gerlofs Donia for exemple, that just by his own absurd size and sword size could make men shit their pants in battle, and with proper techniques you don't even need to be big to use the weapons. Video from a guy who trains this kind of sword techniques: <https://www.youtube.com/watch?v=vxHaNRO705k> [Answer] Armor and training is a big factor. Even in your Selmy example, he actually had an entire scene of removing his armor, and still had more on then most of the room. With enough training, practice, and armor, yes a single knight can take on an entire room. It's happened frequently in history (reference the Templar knights). Stamina is a big factor, but so is technique. I once went to an archery range and this old guy in his 80s was tending the counter. I asked him about this bow, and I couldn't even pull it. He told me it was set to 90 pounds, he then shuffled up to me, weakly picked up the bow, then somehow smoothly pulled it back and fired a shot at the target. That's an example of skill trumping strength. He knew the exact way to position his muscles, whatever remained of them, to pull that huge bow, hold, aim and fire it with little trouble. I imagine a master swordsmen is the same, they would know exactly how to swing and parry with maximum effect and minimum energy expenditure. Also having the correct weapon. In fantasy, everyone is swinging with their mounted swords, that's unrealistic and would be very tiring. But a musketeer would easily dispatch Selmy because their weapon is meant for getting between the chinks of the armor, and their own armor is designed to take arrows and bullets and swords. Despite how unrealistic the show was, Deadliest warrior actually did show this concept very well with the spartan battle and having equipment designed to kill with every strike (again not like Hollywood). Even their shield is a deadly weapon. [Answer] I'm a trained Iaidoka (samurai katana ritualized fighting) as well as a Live Action Roleplayer, where medieval-style combat is common. A trained fighter can absolutely take on a 3:1, 4:1 or 5:1 group of enemies. In fact, in Iaido there are many katas that assume you are facing multiple opponents and how to cut down three or four enemies in about as many strikes and half as many seconds. In LARP fighting, we once held a narrow pathway with four people against an entire enemy "army" (about 50 real people, but with respawns). Location and strategy are vastly more important than muscle or reaction speed. A narrow passage can be held by few against many, and sometimes even by one. There is [the legend of Horatius Cocles](https://en.wikipedia.org/wiki/Horatius_Cocles), who is said to have defended a bridge into Rome alone against an entire army (at least for a short time). The trick to every successful battle of one-against-many is to fight sequential one-on-one battles, i.e. you never actually fight all of them at once. [Answer] So, to sum up the other excellent answers, and to address the OP question: Trainable reaction time and more efficient muscles would have little effect in a one vs many battle. A blade and field of vision can only cover so much flank. BUT the psychological aspect of seeing such a proficient fighter with a high reputation would have an impact on the willingness of a member of the group to engage in a battle with said legendary hero. Further, tactics and situational awareness combined with these physiological improvements would allow a swordsman to last longer in one on one fights and if he could prevent himself from being surrounded could take out more enemies than he would have otherwise. [Answer] ## Strategy is King If you just make your fighter and faster, all you do is tweak the number of people they can take on. You can always just pile on more people. It takes strategy to win against an unbounded number. Physical acumen can help, but strategy is key. > > Hence the saying: If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. > > > If you know neither the enemy nor yourself, you will succumb in every battle. > > > * Sun Tzu, *Art of War* (chapter 3) > > > The master swordsman is not just a swordsman. He is an illusionist as well. He knows that the fight is not just in the flesh and steel, but in the minds of the fighters as well. Through knowing himself, he has learned to know others. And thus will not fear defeat in a hundred battles. The master swordsman is a survivor. He does not enter a battle unless he already knows he can win. This means he has already seen the loss in the minds of the other fighters. We know this because we see "taunts." We see attempts at intimidation. These are approaches which try to make the opponent think they have already lost. However, the master swordsman approach must be more subtle. It must find the loss that already exists in the opponent's mind, and strengthen it until the opponent cannot ignore that illusion. IF they do, the enemy hesitates. If they do, the swordsman can pair enemies off against each other. Indeed, the typical approach to winning such fights (in the movies, of course) is to use the bodies of one's opponents to get in each other's way while the master swordsman moves freely. This kind of skill is not easily gathered. Indeed we typically think of it as impossible, which is why it is relegated to the awesome fight scenes in movies rather than the history books. But it is technically possible. If you can get in your enemy's mind and strengthen the false preconceptions they might have about the world in your favor, [it really doesn't matter how much steel they bring to the fight](https://www.youtube.com/watch?v=QDyQ4e_shm4). Of course, it's easier with Magic (or just being awesome like the Doctor). I wrote an example of what it might look like in [an answer](https://worldbuilding.stackexchange.com/a/17011/2252) about Alynn the mage who sought to try to hide her telepathic and telekenetic abilities so that she wouldn't be run out of town. I can't say whether it is good prose or not, but I had fun writing it, and it does try to capture what a fight might look like when an opponent's mind is already lost. [Answer] I want to point out a few things that might help add to the answers, but may not be important enough to be a primary answer. **Anticipation** If you want a character who is able to best several elite swordsmen, then they should be able to anticipate what elite swordsmen will do. This character should have meta knowledge of how elite swordsmen fight, and should be able to anticipate the ways in which they always consistently strike, and instead of reacting to their movements after the movements are seen, would counter the movement that he knows they are going to make. If there is variance in the options that an elite swordsman might have (i.e. if the next move is unpredictable), then this master would avoid the unpredictable situation entirely by taking a step back and moving out of range, then moving back into range in a way that creates a more predictable state. This master should have spent extensive time planning out how to counter standard attacks. He should be very perceptive to slight tells in the opponent's next move, such as the initial contractions of muscles and the dilation of pupils. This master should also set traps, e.g. by feigning an exploitable weakness, and then countering the expected exploitation of his feigned weakness. The setting of traps is something that should be well-rehearsed. **Group Tactics** The master should also use tactics that attack a group of opponents as a whole, rather than as numerous individuals. He should use multi-purpose maneuvers e.g. parry one sword in a way that forces it to stab a third party or in a way that forces it to parry a third party's attack. If he is not well-positioned for multi-purpose maneuvers, he should make slight lateral movements to a position that is more ideal for a multi-purpose movement. The master should have thoroughly practiced multi-purpose maneuvers, and should have multiple training partners willing to help with this practice. The master should make use of space and footwork so that the adversaries are bumping into each other or failing to cram into narrow spaces together. The master should make use of movement to corral the opponents into a group and fight the front opponent in that group, rather than being surrounded by them. The master should never be surrounded in the first place, because as soon as people start to surround him, he should sprint towards an exit point to get outside of the circle; and as an uber master, he should have a sixth sense for when people are beginning to surround him. He should run through doorways and then fight the opponents as they attempt to filter through the doorway. He should utilize numerous non-sword attacks and tactics such as slicing chandelier tie-downs, flipping tables (flipping a table on its side can create a barrier for movement that can prevent opponents from efficiently circling you), and splitting inflamed alcohol. **Visualization** If you are surrounded by numerous elite swordsmen and having to defend strikes that are coming from behind your back, then how can you approach that? Eyes in the back of your head? This master should have advanced visual memory that can keep track of the location of opponents who are standing behind him combined with the ability to anticipate how they will act while they are behind him. This should be honed by way of difficult visual exercises as well as practice with swordfighting a training partner who is standing behind him. **Stamina** To make a parallel to boxing, boxers who are experienced at the world class level (even if they may be experienced in losing at that level) and experienced at going many rounds can potentially "take an opponent into deep water and drown them." What this means is to use stalling and damage mitigation tactics to force the fight into late round (e.g. beyond round 7) and then beating them with superior stamina and having paced themselves better. In a similar vein, I propose that the master swordsman use stalling tactics such as defense, running around, and generally evading to draw the fight out longer. In a very long fight, you can leverage your stamina much better. Also, making a parallel to certain strategy games with luck components (e.g. Magic: The Gathering), a superior player's skill advantage can sometimes be trumped by luck, especially in a short game where few decisions are made. But if the superior player plays defensively and draws the game out into a very long game in which hundreds or thousands of decisions are made, the less skilled player will inevitably make dozens or hundreds of mistakes, and the more skilled player will win. So I propose that if the master swordsmen uses stalling tactics and movement to produce a very long fight, he is also likely to be presented with a vast multitude of opportunities to capitalize on mistakes. This applies especially when fighting larger numbers of less skilled opponents (yes, sometimes he needs to defeat 8 elite swordsmen, but aren't there also times where he will have to defeat 39 intermediate swordsmen?). It should not be assumed that most medieval elite swordsmen are also world class endurance athletes. Therefore, there is the opportunity to gain an advantage if the master IS a world class endurance athlete. My opinion: he should sprint one mile before beginning 6 hours of sword fighting practice, and jog another 7 miles after practice. [Answer] Your main problem is that swords are reasonably deadly and there's a limit to the movements a human body can perform. One grandmaster will almost certainly lose against a room of elite soldiers if he isn't wearing full plate armour or can use a chokepoint to fight them one at a time. That is because they only have to hit him once in order to win and even if we assume that he won't ever make a mistake or get exhausted, they can surround him and attack multiple places at once to make it impossible for him to parry or evade. Being able to see the attack coming won't help him there, nor will being strong or moving fast unless he is several times faster than an "elite". If he's wearing full plate he might have more of a chance, but it's still possible for them to pile on him and pull him off his feet, at which point he is doomed. Assuming they're not wearing any armour though, he might be able to cut them down while positioning himself cleverly enough to remain standing. [Answer] A combatant who is drastically stronger than the opponents they are facing has access to a huge advantage: **reach**. The degree of strength that you would need would be bordering on supernatural, but wielding a very large, long weapon while maintaining elite skill and speed with it might enable a master to take on multiple opponents successfully, especially if they can do it 1 handed (2nd weapon or shield in the other). And keep in mind that reach is a function of the size of the fighter, so a large weapon plus overly long arms can give a huge reach advantage over an average person. Look at some of the wingspan measurements of NBA players to see just how extreme the proportionate length of a person's arms can get. And in line with what others have said about the psychological aspects, facing an opponent with this kind of reach advantage would be terrifying. Trying to close the distance with them as they moved away from you, attacking you freely while you can do nothing but defend yourself. Who is going to throw themselves at that? Even a surrounded fighter with this kind of advantage might be able to create enough room around them to attack and breach the encirclement and manouver for better position. This seems like a way to create an "untouchable" master, even a large group of opponents would almost have to throw themselves into suicide knowing that a number of them would certainly be killed in an all-in rush. What is their motivation to do that? [Answer] Allow me to direct your attention to Cyrano Bergerac. Yes, **that** Cyrano Bergerac. Yes he was a real person. Yes, he really did fight duels over insults to his nose (though not as many as the play would have you believe.) Yes, he really was a master swordsman with several really nasty fencing tricks credited as his inventions. More relevant to this question: as far as we can tell, yes he really did once take on an entire gang of armed men all by himself. One of his friends had offended a nobleman, and the nobleman had hired 100 men to stand at the town gate and wait for the poor soul to try to go home so they could murder him. (The number may be exaggerated, but probably not by that much. The goal was to show off how powerful the noble was to be able to afford such a lavish way of disposing of a single nobody.) Cyrano would have none of this and escorted his friend home. According to the witnesses, the result of the battle was two dead, seven wounded, and a great many pikes, sticks, and hats discarded by the rest as they were attempting to flee. <https://archive.org/details/voyagetomoon00cyra> (The translator's note contains the story in English with the names of the original reporters if you care to investigate further. Also the book's not half bad if you like Renaissance Sci-Fi.) So yes, a single, well trained psychopath with the element of surprise, little fear of death, and a demonic grin on his hideous face can certainly overcome an entire room full of fighters. The key is to get that panic started quickly. Once it takes hold the opposition will dry up and blow away like leaves. The difference between a fencing expert and a fencing master is that the expert fights their opponent's body while the master fights their opponent's mind. [Answer] When Legolas or Captain America or whoever is surrounded by a half-dozen men, he doesn't keep parrying them all until he can take them down one by one. Instead, he'll spot an opening to, say, jump off the outstretched leg or sword of one attacker and vault out of the circle to catch his attackers from behind. Of course the movies do this because it's more dramatic, and also easier to demonstrate visually. But as a side effect, it often feels *less* implausible, not more, than the traditional alternative. One man parrying six blows aimed at different parts of his body from all sides in the span of a couple seconds? Ridiculous. Having the superhuman reflexes to spot and take advantage of an opening that a normal man couldn't? That's easier to accept. (Of course when poorly done, it just looks ridiculous. But just don't do it poorly…) I don't think the reflexes need to be at the superhuman level of an elf or steroid super-soldier or whatever. Just being a little outside the realm of real-life human experience is enough, because we don't have solid intuitions of what's possible outside that realm, so we can suspend disbelief more easily. Especially since being even a little bit superhuman is going to have the same effect in-universe. If you just saw someone do something that nobody you've ever sparred with could do, you have no idea what else he can do. All the tactics you know could be completely useless. A smart master swordsman will exploit that. So he won't have to fight 100 average swordsman, he'll fight a couple of average swordsmen, then a couple dozen worried and tentative swordsmen who are much easier to take, and the rest will just run away. I'm not sure more strength will work for that, because it just shifts the whole scale of expectations that your world's swordsmen grew up in. But making reaction time unboundedly trainable? I think that could be enough. ]

[Question] [ The setting; there’s a large population of merfolk living in the ocean, and a developing seafaring human nation on the neighbouring coastline. These merfolk are entirely aquatic. They have gills and not lungs, they would suffocate if removed from water. They can survive on the surface only as long as they can hold their breath, and their bodies are totally unsuited for any movement on land. They have upper torsos, arms and heads that are broadly human-like, and fish-like tails. They live in fairly deep waters and in scattered colonies under the ocean. They farm and hunt sea creatures, they harvest the reefs, and their villages are at least a hundred foot below sea level. These merfolk are well-used to fighting off large predators like sharks, or fighting skirmishes against rival underwater colonies. Technology-wise, humans would class the merfolk as being primitive. They have no advanced tool-making or metalworking (because, well, no fire), but they craft coral weapons, and they can bind seaweed into rope. They primarily wield harpoons and spears, but some have crude crossbows. The merfolk are very good at farming fish, their society is very organised. In the past, humans and merfolk have got along pretty well. They’ve interacted occasionally, but merfolk have had no interest what happens on the land, and humans don’t care for under the sea. The problem comes when the human society begins to develop and expand quickly. Their towns become cities, they start building larger ships, and the human nation starts to trade and interact with other nations around it. Imagine these people as culturally similar to early Vikings. To power this expansion, the humans have begun very heavily fishing in what was previously merfolk territory. Larger populations need more food, and the ocean is the only place they can get it. In particular, human whalers start to target schools of whale and dolphin pods, which seriously upsets the previously docile merfolk. The humans aren't overfishing the environment, but the local increase in fishing is the point of contention. In retaliation, the merfolk start sinking ships. Raiding groups of merfolk warriors use long ropes of seaweed to bind the ships’ rudders and anchor them in place. From then, the merfolk use coral saws and blades to hack through the hulls from below, and they drag the helpless ship down. Any human that jumps overboard is promptly slaughtered in the water. This is difficult work for the merfolk (sawing through hard wood with crude materials isn’t easy), but the human sailors have no real way of defending against them. Harpoons work somewhat, but the merfolk have the huge advantage of movement under the water compared to the men trapped on boats above. The merfolk successfully sink several of the human fishing and trading vessels. Back on shore, this is an outrage. The human king stamps his boot, and says this is enough. The humans declare total war on the merfolk. The only problem is… how? How would the humans fight against the merfolk? Submarines don’t exist, and diving with weapons would be foolish - so how can they launch counter-assaults against the merfolk’s underwater villages? Drop barrels on them? Poison the water? They have no idea, they’re looking for a way. Is there any means to protect their ships from an organised attack from below? To trade, they must travel through merfolk-infested waters, but all of their ships are (literally) sitting ducks for the merfolk. What do they do? For answers, assume that this is a low-fantasy setting. Solutions that rely on magic are possible, but discouraged. [Answer] A mercenary war. You are not going to win this fight human to merfolk. But as you mentioned the merfolk are not a unified people. There are warring tribes. You also have technology that they don't have. You can make leather armor and metal weapons. Send your diplomats. Find the most hated, misplaced tribe. Maybe there is an uncle that believes he deserves the throne. Arm them with human weapons and in exchange let them kill your enemies. Besides weapons there must be a ton of surface things murfolk find valuable. Buy them out, hire bodyguards for your ship. Crush them politically if you can't win a direct battle. What do you do in 50 years against merfolk armed with swords? That's the next admiral's problem. [Answer] When I was a kid I remember there were two types of amateur apnea fishermen: * those who knew how to catch an octopus out of his lair using an harpoon * those who had no clue how to use an harpoon, and relied on copper(II) sulfate. Spreading it in front of the octopus lair forced the animal to escape it and become an easy prey. Your middle ages men are in the same conditions: they might have some skilled pearl or sponge diver, but they are surely clumsy against the meerfolks. Your only hope of having a fighting ground is to pollute the waters around the ships with some chemicals: quick lime and vinegar are those coming first in my mind. Probably copper sulfate was not available during middle ages. Once this is done, the humans can throw nets in the water, aiming at fishing as much stunned meerfolks as they can. [Answer] * If you can live with the drag, hang long lines from the bow of the ship having sharp barbs. The merfolk would need to deal with them before cutting through the hull or be cut up. * Mount short blades (10" - 20") along the hull. Of course, this would lacerate anything else that comes near the ship, too. * Double-hull the ship and fill the space between with something nasty (see L.Dutch's answer, which I upvoted and you should too, but this would basically work only once). * Mount the trawling nets on a gimble so they can be swept fore or aft to capture annoying merfolk. * Mount a log inside the ship to act as a battering ram against the hull. You want to hit the hull as hard as you can without disloging planks. The goal is to cause a sharp concussive wave at the point where the merfolk are sawing, hopefully to knock them unconsious (might not be able to bring enough force against the hull to make this believable). My goal with the list was (a) to have reusable things (supplies can run out) and (b) to not necessarily be on the offensive. After all, most of the ships are just fishing trawlers that want to go about their business, not hunt merfolk. Making them go away is as valuable as killing them. [Answer] There are a bunch of options, each with benefits and drawbacks. And don't forget that the merfolk are smart too. So here's a few things to chew on: 1: Just plate the hulls with metal. It doesn't need to be thick, just hardened. Coral and stone tools have a difficult time cutting wood. A thin plating of metal would prevent them from finding purchase at all. Just be sure to weld the seams so they can't wedge something under a corner and pry it loose. 2: Jamming the rudder won't stop the ship, only keep it from turning. Sailing ships can also be steered with the sails if the crew know what they're doing, it's just less precise and more labour intensive. Design the rudder to be retracted to prevent damage and just sail away from the enemy. 3: Biological warfare: Find a water creature with sharp teeth and claws and train it to attack merfolk relentlessly. Otters and seals are probably about the right size. The merfolk can adapt to this, but it will make their work more difficult. 4: Most water creatures have extremely sensitive ears. A sufficiently loud siren using your ship's entire hull as a transducer might well deafen them, perhaps permanently. 5: The fishing nets are the human's best weapons. Drop them off the bow, drag them to the stern, and lift them up. The quicker the better. Whack the captured mer on the heads with a club as you trundle the nets back to the front and add them to the catch, it's not cannibalism if they're not human! 6: Gills work by having the water go in through the mouth and out through the gills. For the humans to go underwater for extended periods requires pumped or compressed air. At a medieval tech level that's not impossible, but it is difficult and expensive. For the merfolk to go on land for an extended period requires... a bucket... And since the water will exchange CO2 and O2 with the air based on surface area, it might well be possible to design a garment that re-aerates and collects the water using nothing more than sea-creature leather and intestines... Humans beware! The land isn't safe either any more! (And things are going to get messy for the men as the mer trade with human groups they're not at war with and learn how to use fire on the beaches for working metal.) 7: The merfolk could just ignore the ships and attack the fishing nets. Nets have to be large and therefore difficult to defend to be effective, and making them out of materials that the merfolk couldn't cut would be prohibitively expensive. (Although why they'd cut them I have no idea. Just steal the catch and let the silly landfolk figure out what's going on as best they can.) 8: The merfolk don't need to cut holes in the ship to sink it. Drive some spikes into the side, attach a rope, and capsize it. For smaller ships, muscle and a bit of rocking would suffice. For larger ships anchor a windlass to the sea floor and just pull it over. There will be plenty of spikes and other metal pointy things salvageable from the first few ships they sink. 9: Why is this even an issue? Humans aren't nearly as well suited for fishing as the merfolk are. They'd probably trade the humans fish and whale meat by the ton in exchange for metal items, not to mention all the other neat (to humans) things that bespeckle the sea floor that humans can't get to but that the mer could just go pick up by the basketfull. 10: Since both sides are composed of essentially fractured tribes, both sides would be able to hire mercenaries of the other species from outside the conflict zone to take the fight to the enemy. [Answer] It will hardly be a fair fight, until the right genius's ideas are put into practice. So, without further ado, we present the **War in the Deeps**: * Our medieval navy will first have to adopt a novel design for its modern day warship, namely the *catamaran*. * Next a corps of valiant *Meerknechten* will be equipped with an apparatus allowing them to enter the watery deeps and bring the battle to the Meerfolk; * For weapons, the knights will carry, apart from sharp filleting knives, one or more kinds of *kinetic spear*. As I see it, modern (that is to say, *medieval!*) under sea warfare will look something like this: Sailing out to the nearby Meerfolk settlements in their **dugout Catamaran** warships whose thick nearly solid hulls make hole boring & sawing nearly impossible, [](https://i.stack.imgur.com/QlAxi.jpg) the king's **Meerknechten** are equipped with Undersea Spectacles and Breathing Apparatus, with double leather walled construction, reinforced with a fine mesh of brass chain mail (in order to confound the coral saws of the Meerfolk). [](https://i.stack.imgur.com/AbKlx.jpg) Each contingent of Meerknechten is accompanied by leather finned **yeomen** armed with daggers and charged with "minding the lines". [](https://i.stack.imgur.com/H5ERY.gif) All the knights are armed with the DaVinci **Mark VII Sperregonne** [](https://i.stack.imgur.com/b28qG.jpg) and eight inch **filleting knives** for close up work, [](https://i.stack.imgur.com/hbtps.jpg) They will easily be able to dispatch King Neptune's finest **Meerfolk Warriors**: [](https://i.stack.imgur.com/1fcUP.jpg) Meerfolk are quick swimmers, but their weapons are not ranged. The knights have the advantage with their spear throwers, allowing them to fire off one or perhaps two volleys before the enemy approach too closely. A tactic recently devised involves a kind of windlass affixed to the deck of the warship which will, when engaged, draw the *meerknechts* up and away from the enemy, allowing them to fire volley after volley into their ranks from a safe distance. [Answer] You are not winning without explosives. It is probably not that hard for a medieval society to invent depth charges. China invents gun powder by the 9th century. These weapons would be devastating. Ships head for villages and then drop these depth charges. Protect the ships how other questions suggest. Spikes spikes on the hull, ropes with nets and razors dangling under the ship. The amazing thing about water is how well it caries explosions. A submarine can be damaged at 28 meters, but the range of hard to a body can go to a hundred meters. Eardrum damage may be even more. A couple of such bombings targeting civilians may very quickly convince the murfolk not to engage civilian targets. At that point if they want to fight a proper civilized war, they can figure out how to come to our battlefields. [Answer] **Depth charge** Your people are upset, the army has tried everything but as it's imposable for any man (or woman) to stay underwater long and the merfolk have an advantage underwater a frontal assault would be foolish, luckily a young brash pirate (he prefer being called privateer) has the answer, during is travel in a far away land he came across a substance that is roughly translated to "black powder", such a substance was used by the locals for a long time (According to Wikipedia The first military applications of gunpowder were developed around 1000 AD in RL), for the right price he is confident he can steal\buy\bribe the secret of making that substance, and once that's in the local navy hands all it takes is making a lot of it and stuffing wooden barrels with it, cover in raw hide\use varnish\etc to make them watertight, add a fuse (make it internal and keep enough of the barrel empty to leave enough air for it to burn) and you got a rudimentary Depth charge, next time the merfolk attack light the fuse and throw them overboard, even if the merflok avoid a direct hit the shockwave of the explosion should cause some serious damage (water transfer shockwave much better then air). best part of it is there is noting the merfolk can do to defend against it, noting made underwater naturally is strong enough to survive an explosion so their only choices are to stop attacking or to die trying. **Poison** You know how after a chemical spill there is a bunch of fish floating death? merfolk are basically fish with hands so why not poison them? it doesn't have to be high tech it just needs to be a lot of poison that's dumped out the side of the ship, even feces and urine will work with enough of it but even in the middle ages there where much stronger poisons known that would require fewer gallons carried onboard. **Bigger fish** You mention the merfolk fighting sharks, so why not attract them and let them kill (or distract) the merfolk while the ship sails away, blood in the water is one way to attract them, fish chum (gutted fish guts) is another proven way. [Answer] # Attack the food source By the later middle ages, but before cannon were on the scene, castles were nearly impregnable. Knights still wanted something to do, so [they rode around](https://en.wikipedia.org/wiki/Chevauch%C3%A9e) killing farmers and burning crops. If you want to drive the merfolk out, get rid of their food source. If they eat fish, get rid of the fish. One way to do this is to try to get rid of all the phytoplankton. That's not easy with Medieval technology, but there are critters that can do it for you, and at the same time the merfolk won't be able to use to their advantage. Breed and release lots of [salps](https://en.wikipedia.org/wiki/Salp) or [jellyfish](http://edition.cnn.com/travel/article/jellyfish-taking-over-oceans/index.html). You can also try to coat the ocean floor with [mussels](https://en.wikipedia.org/wiki/Zebra_mussel). If the merfolk are technologically primitive, they would have trouble competing with these 'invasive' organisms. # Alternately, protect your ships better. Now, from a Medieval knowledge point of view, it is not obvious that the previous solution will occur to anyone, not knowing much about invertebrate life cycles. As an alternative approach, you could do a better job protecting your ships. If you have metalworking technologies, and the merfolk don't, then [copper plating](https://en.wikipedia.org/wiki/Copper_sheathing) on hulls would be a long lasting deterrent. If the merfolk can't drill through the bottom into the ship's under-sections, then they have to come to the surface to fight and their advantage disappears. An iron ship will float, as we know these days, so the kingdom could spend some money to make the first 'ironclad' some 500 years early. The merfolk would not have any success cutting into or otherwise harming an iron hull. Combine that with crossbowman on castles and merfolk won't have much success with attacking the ship; or at the very least they will take heavy casualties. With your new iron ship, you can proceed to do the most destructive fishing or whaling that you can accomplish. Alternately, you could drag stone anchors (on a metal chain) over the ocean floor in an attempt to damage merfolk structures. [Answer] On deck hearths, small but fiercely hot vented furnaces, heating lead, oil, water water and small lead shot, iron BBs, medieval caltrops, small rocks, pebbles, cast off broken iron armour etc etc... slung at the gunnels in rolling racks, iron mesh netting to a half-fathom's length with heavy lead weights at the leading edge which have sharpened spikes blades etc protruding... all crusted in lime or other strong alkaline and abrasive. Heck, use Greek Fire or Automatic Fire with quicklime which only combusts in contact with water... As soon as a merfolk attack is detected, the iron netting is percussively deployed, fore, aft and port and starboard - as soon as it's 75% down (and it will cause significant merfolk injuries on the way down) the heated slops and shot etc is deployed through runnels reaching around the boat's profile dangling to halfway to the waterline (therefore INSIDE the perimeter of the iron netting) with the admixture of a ***lot*** of small waterproof fireworks laden with iron filings. Why? Your merfolk will have, by our landlubber standards, *very* delicate skins (something like a cross between octopus and dolphins) so the abrasives will be sheer agony, the alkali will provide time-delayed chemical burn impacts and unreasoning terror, the iron filings and explosives will disrupt skin integrity - and remember that continually-wetted skin / hide in an oceanic setting is an infection barrier under *constant attack* from biofilms, molluscs, flukes, barnacles, and other far less cuddly things... Those merfolks skins will be incredibly sensitive, and thus a positive sensing resource for hunting at sea (not having had serious evolutionary competition at the top of the food chain) helping merfolks detect prey (think sharks and their electroreceptive sense) alerting based on the *tiniest* changes in water chemistry and temperature - and you have just trapped them in a space and forced them to encounter chemical attacks, massive thermal gradients and hotspots, high-speed (for a short distance) particulate metal (at temperature) AND the horrifying compressive impact of undersea explosions... A few of these floating round as decoys amongst your fishing and shipping fleets will wreak unholy havoc on the merfolks... and as indicated in another answer - if you can, using this escort method, fish the hell out of a given area - this creates a localised food desert for the merfolks, and they must, perforce, relocate. [Answer] While it will also affect the fishing, you could drop steel rods over the side and let them hang in the water. When being attacked, strike the rods with a hammer. Some experimentation would be required to find the best tone or combination of tones for driving the merfolk away. [Answer] If your medieval people understand why the attacks are coming, the best approach is to find a way to solve the original problem. Find some other way to get enough food. Farm new land, find new foods that can be farmed on land that has not been worth farming before. Trade for food with somebody else who has a reliable surplus. If you can't do that, then you are eating up the same food the mermen need, and it will only get worse as your population goes up. They cannot surrender, all they can do is fight until their population has been reduced to the point they can survive on the reduced food, and then face further reductions later, until they are mostly gone. Or possibly they might find somewhere else they can migrate to until your fishing fleets arrive there too. They will salvage metal tools from sunk ships and use them to attack you. Chisels. Maybe saws. Whatever works. While you invent new military technology, they will too. They might find out how to use fire above the surface. Every bottle of distilled alcohol on a sunk ship could turn into a firebomb that could be tossed into a new ship. Bottles of oil similarly. And grease. You might win. It will cost, and it will take a long time. If there's any way to get your food elsewhere, that's likely to be a better solution. Then start learning languages, and see if there's anything to trade with them. It might turn out it's more efficient to trade things you can make easily for fish etc, than to catch the fish yourself. Don't get into a genocidal war if you can help it. And for gods sake don't get into a war with somebody you don't know how to talk to. That's a crazy thing to do. [Answer] Realistically humans can never completely beat a merfolk civilization with Medieval technology. They can only suppress interruption of their fishing activities. Here is why a merfolk enemy can't be fully eradicated: they can hide at the bottom of the ocean. No matter what the humans try to do to attack merfolk, if the merfolk hide deep in the ocean for example the bottom of the [Mariana Trench](https://en.wikipedia.org/wiki/Mariana_Trench) as an extreme example, nothing will be able to reach them and do any meaningful damage. Certainly nothing that wouldn't also completely destroy the Ocean and make fishing pointless. Dropping rocks, bombs, nets, or whatever you think of will be prohibitively expensive for humans who have to ship it out to sea, but be easily avoidable by merfolk who only have to dodge these devices, or be somewhere else. The very best a human civilization could do, is to reduce the merfolk to guerilla tactics and bands of rebels by defeating any standing armies outright. But that is all you could ever hope for. So if fishing is what the humans are after, it would make more sense to find a way to ward off merfolk. I've seen metal plating mentioned, sonic warfare, dynamite in the water, etc. Outright defeat is however impossible. It is like asking how a Medieval army is going to defeat an enemy that lives on the moon. It is not going to. It can only stop interference into its own interests. [Answer] I agree with @elemenas that catamarans are a valid option. However, solid wood hull and chain mail would probably be too resource-intensive, and the chain mail would cause too much drag. I think that there is a simpler, but still related solution. First, make a few catamarans, or just tie two small fishing boats together so there is a gap in the middle. Then, station men armed with pikes and harpoons on both hulls and set sail out to merfolk infested water, and wait for their attack party to approach. The catamaran design should prevent it from capsizing, and armed men stationed on both hulls will give you a position from which to spear the aquatic saboteurs. Basically, when a one of them tries to saw through one of the hulls, a pikeman on the opposite hull will be able to spear the merperson before he saws through the hull. This process would continue, with pikemen on each hull spearing any merperson swiming below the opposite hull. Eventually, the merfolk would learn not to attack the catamarans any more, and you would be rid of your problem. You could even use the same concept on a full sized ship as well. Instead of using a catamaran, you could just hand a couple of platforms six or so meters off the sides of your ship and station pikemen on these. That way they could defeat any merfolk under the hull of the ship that would otherwise not be reachable by those on deck. [Answer] **Eutrophicate** This involves dumping all wastes into the sea: * Livestock remains. * Sewage. * Trash. Aerobic bacteria would thrive on the food supply and consume all the dissolved oxygen. All creatures with gills would die of asphyxiation and become more food for bacteria. Nutrients in the waste would fertilize algae, which would block sunlight from aquatic plants and create a "fog of war". Blood would attract sharks. Reinforcing the shark defenses would presumably require resources diverted from the human offensive. ]

[Question] [ Today a weird guy with a pointy hat offered me and my friends to play a game: We will all travel back in time, to a random date somewhen from the antiquity to modern times. We will have a limited amount of time to do whatever we want before returning to our current world. After that time, each of us tries to guess the date we travelled to and the winner is the one who comes closest to the real date they travelled to. Details: * It's not time travel per se, but more a kind of simulation, so interaction in the past won't have impact on the present. * We will all travel to the same time period, but we will not be able to interact with each other. * We will stay more or less in the same area, i.e. western Europe. Sometimes in the middle of a forest, sometimes inside a city, but always western Europe. * Each of us are fluent in French, and know some basics of English, Spanish and German. Local people will speak the language that was spoken during their time period in their specific region. * We are not historians, and even subjects to some TV-tropes and other cliches. * We can't bring any device with us, like a computer or astronomical tools. * The amount of time before we come back to the current time period is unknown to us, but always between 5 minutes and 5 days. Ideally, I would like a method to do a rough estimation, and narrow it more and more untill I came back to modern times. * If you die in the simulation, you go back to the present. Being killed have no impact on current time, but is still good to avoid as you can feel pain and you will have less time than others to estimate on what period you landed * We have no time to prepare ourself: the wizard just give us few minutes so we can decide if we want to play, but no time to learn greek or do a PHD in history. I can do a quick google research like translate a phrase in latin, but nothing that take more than a minute. * Estimation such as "X year of reign of dude Y" are accepted if it's the contemporary way to count years * You have to answer immediately after you get back This might be seen as a duplicate of the question [My time machine needs to know when it is](https://worldbuilding.stackexchange.com/questions/116454/my-time-machine-needs-to-know-when-it-is) at first, but that question focuses on tools and science (astronomy, carbon dating...) to have an exact dating, while my question focuses on estimation using no tools, interacting with local folks, trying to evaluate technological advance, studying architecture... **How could I know *when* I landed?** [Answer] It's hard to come with a single method that both works when you have 5 minutes in a dense forest, and 5 days in a city. But here are some ideas: * Find out who the current pope is. * Locate a graveyard (or a church with in-church burial), search for the most recent date on a tomb stone. * Search through church records (weddings, burials, baptism) for the most recent date. If you've landed (or rather, suspect to be landed) in the 19th, 20th or 21st century, search through city records. (How to get access to those records is left as an exercise for the reader). * Try to find out what the current art movements are. (This will work better the more you are to current times). * Availability/scarcity of food in general, or specific foods. Is salt scarce? Is sugar available? How do carrots look like? Do people drink tea? Coffee? Are exotic spices available? If so, how affordable are they? * If you know (or figured out) where you are: which landmarks are there, and which ones are not there yet? * What type of clothing do people wear? * What kind of ships/boats are people using? [Answer] * Search for some money: coins were made according to the reigning king, they might give a fair estimate for the period you are in. * If you are in a major city, take a look at the most recent churches or religious building. Their architectural style can hint to the period. * Search for potatoes, corn and tomatoes. At least you can tell if you are before or after 1492. * Search for some soldiers: their weapons and uniform can point you to a time period. * I would not ask around "which year is this?", as it would be highly suspect. Once you have a rough estimate of the region and the time period, try asking how long has it been since . I.e. if you suspect you are in the South of Italy shortly after the Battle of Canne, try asking "how long ago was the battle of Canne? 5 years?" [Answer] You only need to learn the phrase "What year is it?" in Latin. If you can find civilization, you'll most likely find clergy and they can answer your question. [Answer] There are a few simple technologies that should be very widespread that you can look for. Stirrups (you’re almost certainly in the 8th century or later), chimneys (16th century in ordinary homes), horse collars (10th century), iron horseshoes (12th century), glass windows (17th century in ordinary homes). [Answer] Find the nearest Pub, Tarvern, or Bar. You only need to play drunk and know one sentense in the different language you encounter. Now repeat after me and don't worry about the accent you are drunk: > > "My Wife is going to kill me! What day/month/year it is?" > > > And you can also locate yourself with this trick. > > My Wife is going to kill me! Where the fuck m'I?" > > > If there is no bar, pub or tavern.. I don't know what is the worst beeing lost in time or no bar, pub, nor tavern. [Answer] You should first make a rough guesstimate of which time period you are in (based on architecture, fashion, tools, etc. that you see), and then go from there: **modern times** If things seem more or less modern, say 18th century or more, look for a newspaper, which should have the current date. Newspapers came into existence in the 17th century, so from the 18th or so onward they should be common enough that you can find one easily. **middle ages** From around the 12th century, figure out where you are, by language. If you seem to be in England or France, or in some place that seems more or less organized, go to the local church and get a look at their records. The middle ages were notoriously beaurocratic and kept an excellent record of births, deaths, marriages, taxes on market stalls, sizes of grounds of each farmer family and a hundred more things. Typically, the local church was the place for these records. They will contain the date somewhere. **early dark ages** Between the downfall of the Roman Empire and the middle ages, things are a bit messy. Your best bet might be tombstones or churches where dates are inscribed and then making a guess on how old they are. This far back, these are likely also the only things that you have a good chance of reading and understanding as what passed for english (or french, spanish, etc.) at that time is not very close to our modern versions. And remember that dates are most likely to be inscribed in roman style (i.e. MMXVIII) **Roman Empire** If it seems that romans are around (look for latin inscriptions on still-in-use buildings, or roman fashion), and you speak a bit of latin or can memorize a few phrases, simply ask for the date. Yes, it might be weird, but Rome was a mix of so many cultures that especially if you seem foreign and speak bad latin, it is quite plausible that you don't know the year *by roman reckoning*. Note that you could land in the time of the Roman Empire but outside its borders (Scotland, Scandinavia, Northern Germany, etc.) in which case the section below applies. **antiquity** If you don't see any roman roads around, and it clearly isn't yet the middle ages as well, you are in antiquity. Good luck. There will be almost no writing or inscriptions available, nor will anyone speak something that you would recognize as a language you know, even if it is an ancestor of such. Your best bet is to look at what tools, clothes and building style people have and then make a wild guess. (for example, you can look if there are iron tools - but iron working was introduced between 1100 BC and 500 BC, depending on which part of Europe you are in - and good luck finding that out.) [Answer] You look to the stars. And look for the [Barnard' Star](https://en.wikipedia.org/wiki/Barnard%27s_Star). And the distance from a line you setup at the moment of travel. The thing is that Barnard star travel a "pinky length" every 350 years [Observing star for amateur astronomer](https://oneminuteastronomer.com/8869/barnards-star/). So you just measure the pinkies and approx. the time with +/- 175 years. you would need some more time than 5 minutes but I assure you that if you get spawned in forest prior to industrialization (and some part of modern times) even 1 day could not be enough to get to any signs of civilization. [Answer] Perhaps you could look up, in both Latin and Greek if possible, a question akin to "How many years ago did Jesus Christ come to earth?" With a little convincing, and communication with any member of the church, friar, monk or priest, you would likely be able to play ignorant enough that it would seem like a naive question rather than the ramblings of a madman. Obviously, anyone with any sort of religious education would know Year A.D. = years since Jesus' birth. Would be quick and dirty, plus most of Europe would be within a few days of the nearest religious figure. Keep in mind, calendars change and are variable. However, the Catholic Church has been pretty solid on having at least internal consistency. If you're dealing with Catholics, Pre-1582 dates should be specified in the Julian Calendar. Since local time systems seem to be acceptable to the wizard, that should work. After 1582 it may be a little shaky, but good God-fearing Catholics will generally be on the Gregorian Calendar. Protestant Europe would be trickier, but then again, Jesus' birth would still be a good milestone, and a decent first-pass guess. Vernacular mass will be a dead giveaway if you're in Protestant country. Another option would be to get the basic formula of a Catholic Mass down, and pray (haha) that your period of time allows you to get to Mass. I believe Catholic Latin Mass should generally reference the name of the reigning Pope. That gives you a pretty narrow window, for most places and times. And if the mass is being held in NOT Latin, that's a pretty huge hint too. [Answer] Not really an answer, but if you are more than 500 or 600 years in the past, the local French or English will be hard for you to understand. Best case scenario, it will be easier for you to understand a drunken Quebecois or Irishman than someone speaking Middle French or Middle English. And the further you go in time the worst it will be. [Answer] During your minutes of prep time, look up how to write "What year is it?" in as many languages as you can think of. You already have a head start because you already know this phrase in four of the most useful languages, so you can try to learn Italian, Latin, Dutch, Portuguese, Swedish, Arabic (for the years 711 to 1492), Basque. When you land write them down as soon as you can. If you're allowed to bring your own paper and a pen, then this is super easy. The first time you see someone, you can show them the paper and try to sound out words, and give them a chance to write down the answer. If you have an informants that are familiar with one of these languages, and are patient enough to work through your strange pronunciation, spelling, and handwriting, I think this is the method that is most likely to work. If you can't get any understanding that way, you can start writing down "ANNO DOMINI" next to years written in Roman numerals and Arabic numerals. At this point, you're playing Charades, and I don't know how easy it is to get an answer. If none of these work, you can start looking for graveyards, and buildings with years written on them. [Answer] Astronomy. Try to figure out your longitude - ie which continent you are on, and hopefully roughly how far east/west on the continent you are. Note which constellation is the lowest and first visible in the east at sunset. And note how far above the horizon it is. This will give you the month, with accuracy of about the week in the month. Note the positions of the planets and our moon relative to the constellations to fine-tune your date and disinguish it from other months in different years. Venus, Mars, Jupiter and Saturn are all easily bright enough to be visible to the naked eye from dusk to dawn, although depending on where they are in their orbits they may not be in the visible sky during your visit to the past. With the help of some astronomy buffs and/or research the combination of data you have should with a bit of luck be unique enough to pinpoint the date with an accuracy of about a week. [Answer] Find a town, pretend to speak the local language poorly (you might not need to pretend). Assuming they speak english "How to say 'now', eh, todaya ina da Henglish pleasea?". "How to say 'this montha', ina da Henglish pleasea?". "How to say 'this yeara', ina da Henglish pleasea?". After a couple of these conversations you'll know the day, month and year. If you honestly have trouble understanding them, get them to write it down. [Answer] If you are in a country that speaks a Romance language, you should be understood if you ask something along the lines of “año?” As the word was pronounced the same in Latin, and you will be mistaken as an ill informed traveler wanting to know the date by local reckoning. You should probably be able to understand numbers, or you can see if dates are written on coins or gravestones. You can also try doing the same for other language families. You might wind up in b.c. in which it will be best to see if you can discover who the current ruler is. You can figure out a rough estimate of where you are via what the weather is like. Be sure to check the word for ‘traveller’ and ‘year’ in an older slavic language as you might be understood and told something of use. ]

[Question] [ If we accept that dragons are *big* and they hoard gold and gems (and don't make or mine these baubles, themselves), **how do dragons physically manipulate and transport human/elf/dwarf-sized coins and jewels back to their lairs?** Even if we assume considerable dexterity of dragons' front paws (namely an opposable 'thumb' claw), their paws are huge, compared to human hands. Unless they win all their loot in conveniently large treasure chests or sturdy bags, how can they grasp gems and coins, without their slipping between the dragon's huge talons? I suppose they could wear clothing (something like a belt with pouches), if they were tool users and had suitable materials. But unless they're cannibals, I think they may need to trade for (or steal) leather, strong thread and needles. (Tool-using dragons might be tough, tough opponents. Hmmm.) [Answer] # Gentle lips and tongue Sharp tongue is sharp for purpose. It's really narrow and flexible, and can grab things rather well. Additionally, old gold taste so good... # Lesser dragon-kin Small, more humanoid race that worship dragons and is what birds to an alligator - service force, tied with their dragon by complex mix of biological symbiotic relationships, religion, and deals. # Shape shift Some dragons may be able to shapeshift into humanoid form. This would help, right? # Pure telekinesis Boring. # Swallow and... Well, you know how birds feed their young? Just give your dragon a [pocket before the stomach](https://en.wikipedia.org/wiki/Crop_(anatomy)) (like a bird’s crop) as a biological storage. [Answer] # If you're a dragon, why are you gathering coins one at a time? If I'm a dragon, the biggest baddest dude on Middle Earth or Faerun or wherever, I'm not going to pick-pocket people. I'm not robbing local barons, I'm going to knock over a king's palace and take the [Peacock Throne](https://en.wikipedia.org/wiki/Peacock_Throne) and the [Crown Jewels](http://www.rozanehmagazine.com/JanuaryFebruary06/ANationalJelleries.html). I'm not going after the loose change in the offering plate, I'm taking the whole [50 foot tall gold altar](https://i.stack.imgur.com/sAxzz.jpg) (from the Cathedral of Seville, fyi). Instead of hitting a tax collector, I'm going to rob the treasury at the point of delivery. All that money is going to be in nice convenient boxes or sacks. Snag a couple of those, and I'm on my way. Basically, I'm going to go after things that are pre-packaged and worth the most. They don't have to stay that way. I may have nabbed a few strongboxes from rich merchants, and if it suits my fancy I'll smash the sides in and let the coins spill out. It makes a more imposing visual effect for visiting hobbits. Maybe I decide to sit on the golden throne and discover it wasn't really made to support my weight? Oh well, I can just melt it down into a nice golden blob and use it as a pillow. Dragons have all the time in the world to put together their collection, and only the occasional pesky knight errant or black-arrowed archer to stop them. Dragons aren't going to waste their time on stuff that takes longer to carry home than it does to incinerate whoever was guarding it. [Answer] ## Become a god, make your worshippers carry things for you. Dragons are clearly too important to do manual labor, let alone the menial transfer of wealth from one location to another. Step 1: Attack a city. Step 1A: Don't kill everyone. Step 2: Tell the rest they will live if they worship you Step 3: Make them into an army Step 4: Go conquer and plunder Step 5: They bring the stuff back to your horde Step 6: Repeat steps 4 and 5 [Answer] The same way that governments, kings, tyrants, and warlords gather their wealth: taxation. If the humans and other creatures in your domain don't bring you enough treasure, torch them. [Answer] ## Sharks of the Skies Maybe when they go raiding and pillaging, they go into bezerker mode, especially when they see a king and his noblemen, and he just gobbles them and anything around them up, like [sharks do](https://www.google.com/search?q=contents+of+sharks+stomachs&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari), Then expells the hard bits after digestion. This theory is all the more plausible because [a full suit of armor was found inside a shark stomach](http://www.nytimes.com/1994/03/04/arts/the-good-side-of-sharks-on-display.html)! [Answer] ## Only small dragons collect coins; large ones don't need to Dragons hoard gold for the same reason many birds collect shiny objects: to adorn their nests and attract mates. Unlike birds, though, dragons never stop growing, even after reaching maturity. A young adult dragon is only moderately bigger than a human. When they are first making their nests, they usually target individual, defenseless peddlers, killing them and taking their purses, which they carry in their claws or mouths. As they grow larger, they will begin attacking caravans which might be carrying large chests. Of course, dragons are highly territorial. Large dragons will often kill or drive out smaller dragons living nearby, then stealing gold from *their* hordes. Some devious dragons will intentionally allow smaller dragons to live in their territory for a while in order to collect more gold before taking it from them. Sometimes, dragons will live in family groups, with the young collecting gold for the family. Dragons with larger hoards will typically have more mates, and more children, allowing the size of their hoard to grow exponentially. Sometimes, a child may "inherit" a portion of the hoard when they leave the nest to build their own, although they will usually not take as much away as they put into it in the first place. Other times, especially in wealthy dragon families, dragons may spend a good part of their lives living in their family's lair; the huge size difference between older and younger dragons means that younger dragons are only able to mate with younger partners, preventing competition between generations. Larger dragons, naturally, will attract adventurous humans to their cave simply by virtue of living there. Whatever was in these adventurer's pockets at the time will naturally be added to the hoard. Most dragons have only a single hoard. However, extremely large dragons may migrate between lairs. When they are away, it is possible that a smaller dragon will attempt to take over their hoard, and will likewise end up adding to it. When the owner returns, whatever the smaller dragon collected will be added to the hoard. Some larger dragons will actually encourage this, seeing the additions as "payment" for use of their nest. Only the largest dragons will do this, as it otherwise carries the risk of a similarly-sized or larger dragon squatter that cannot be driven away so easily. Dragons who are feared by humans may increase their horde even further by allowing humans to live in their territory in exchange for occasional tributes of gold. By the time a dragon reaches legendary sizes, it is no longer collecting coins, instead targeting larger, more impressive fare like golden statues or the crowns of kings. However, an ancient dragon is still likely to have truly colossal piles of coins thanks to the accumulation of collection by children, squatters, adventurers, and tribute. [Answer] Dragons haven't always been dragons. Think about it, when in a movie have you seen an actual dragon take loot? They pillage and breathe fire and burn stuff. But where did the dragon come from? You never see two of them in one area, so there can't be a mommy dragon and a daddy dragon making a family of new dragons. No, dragons were originally another kind of creature, one that walked on legs and had arms and hands that could carry stuff. That creature acquired lots of treasure, and as it did so its greed grew as did its fear of losing its treasure. So it hoarded it all away somewhere safe and over time the magical transformation began as it guarded its treasure in the dark, it morphed into a fearsome creature whose sole purpose was to keep its precious hoard from other, coming out only when provoked, or occasionally to seek sustenance. [Answer] **The gold is an illusion to lure in what the dragons *really* want:** *adventurers.* Dragons don't need gold or treasure. That's just silly. Where would they spend it? The local DracoMarttm? Nope. Gold has no value to a dragon. It's just another shiny rock. **Dragons need food.** And lots of it. And flying around, snatching cattle and sheep from hillsides is tiring work. Much easier to make the food come to you. See, adventurers are high muscle, low fat. They are often fortified with fiber (scrolls, wooden weapon parts, clothes) and iron (weapons, armor). Very tasty *and* nutritious! Sure, they have to travel out and scare the locals from time to time. You know, to drum up business. But as long as the adventurers keep coming, the dragon has to expend far less effort to stay well-fed. *They're the snack that fights back.* Dragons aren't hoarders. They are spiders whose web is made of illusory treasure to lure you in. Eventually, there would be real treasure. Some as coinage / loot dropped by adventurers as the dragon feasts. Some coughed up as [pellets](https://en.wikipedia.org/wiki/Pellet_(ornithology)) after the dragon has feasted. But the initial hoard is fake. [Answer] On Kibota, the world of one of my novels, dragons work in close partnership with humans. When the industrial revolution hit that world, the dragons developed a fondness for trains. Kids love model trains, and to massive dragons, our full-sized trains are like toy train sets. Believe me, you want to have dragons patrolling your lines, otherwise the herds of dinosaurs will cause massive derailments. [Answer] Most people don't know this but a dragon's mouth works like a [pelican's beak](http://animals.howstuffworks.com/birds/pelican-bill-vs-belly1.htm). It has a pouch which expands to hold things. [Answer] **You don't.** I never believed them to find treasure and take it back to their den. Dragons are attracted to treasure, so they go to where other people/creatures have gathered a lot and take over. [Answer] What type of dragons are we talking about? A lot of myths and fantasy have dragons being able to assume a human shape. If that's not possible in this situation, then it's easy for them to force others to do their bidding. Most people would do whatever needed to be done to survive. [Answer] ## Not all the coins are coins; some are scales. Part of the reason dragons pick up coins to begin with is to make them look older, more established, more distinguished (very important for establishing prior claim if your dragons are territorial). But that's *why*, you wanted *how*. And for that, well, it'll depend on the dragon: for instance, some will simply grab whatever they can in their talons, and the trail of dropped coins will likely lead a steady stream of adventurers in pursuit (the first one presumably retrieving the coins as they go), providing a delightful residual income of snacks and treasure. Of course, such dragons *do* have to take care not to attract too many such streams, lest the visitors arrive while the host is out, or worse, scratch a wing. [Answer] Most dragons are known to swallow and regurgitate their loot. Many have magic to extradimensionally expand their gullets for just this purpose. ]

[Question] [ I'm in the process of creating my own language, and so far, I've built a basic vocabulary set of about ~200 words. From here, however, I'm somewhat unsure as to what vocabulary I should work on adding first. Obviously creating a language with the vocabulary of a full natural language, with hundreds of thousands of words, is both improbable and impractical. However, I do want to be able to express a variety of thoughts and ideas in my language, as we would in any other natural language, so to get this effect, I've been using [Wordcount](http://wordcount.org), which tracks the frequency of English words and ranks them. According to [Nation & Waring (1997)](http://www.victoria.ac.nz/lals/about/staff/publications/paul-nation/1997-Waring-Vocab_size.pdf), * Most frequent 1000 words: 72.0% * Most frequent 2000 words: 79.7% * Most frequent 3000 words: 84.0% * Most frequent 4000 words: 86.8% As you can see, knowing the first 2000 words of a language accounts for almost 80% of use in everyday communication. Because of these statistics, I'm inclined to keep using word frequency lists. However, I'm not sure if this is the most effective way to go about it. **Is there a a more effective way to build the vocabulary of a fictional language than a word frequency list?** (I don't want *Just go through the dictionary!* as an answer, by the way.) [Answer] I don't have a reference but some philologists and linguists have speculated that you could survive (explain who you are, ask for employment and food, etc.) in a foreign land with as few as 500 words. Henry C. Fenn, author of several language texts, felt that a vocabulary of 5000 words was sufficient to support learning new words by context, e.g. by conversing with natives and reading newspapers. In my own experience as a linguist and translator I found 5000 generic words plus about 2000 topical words (those popular for only a few years) sufficient for keeping up with current events. This gives you some idea of the vocabulary size you should be considering. I agree that generating a vocabulary by simply making up alternates to the 5000 to 7000 most popular words in your native language is tedious and slow. Worse, it is not fun. Even more worse, the resulting language is at an elevated risk of being insipid and possibly silly. I suggest that you first create a list of word elements, and then compose most of your vocabulary words by altering and conjoining these elements. If you read up on Grimm's Law, and how Proto-Indo-European (PIE) was reconstructed, you'll see what I mean. Web-search "proto indo european word list" and build up a list of element meanings. Throw away the PIE words and substitute your own. You'll probably only need to make about 300 word roots. Make up some rules about combining roots into words. You don't need to be perfect or complete because you are aping a process that takes place over millennia, during which the rules would change. Make up some rules about how sounds might change over time, and apply them consistently across all words. For example: after generating 1000 or 1500 words, change all 'P' sounds in your element list to 'B' and all 'T' to 'D'. Now -- here's how you relieve the tedium and labor, which is the point of all this: Since you are confident that you have a rational method for producing believable words, don't make up all 7000 words at once. Start with a few hundred, and after that, create new dictionary entries as you need them. Whenever you need a word, you look it up in your dictionary. If it's not there, you generate it and add it to the dictionary at that time. Since you already have lots of rules for forming words, making up the new one will be quick. If you don't want to be the sole authority on word formation, you can roll dice or write a randomizing computer program. If the language is being used in a role-playing game, the rule could be "First player to open the dictionary gets to generate the new word." What about the 200 words you already have? Well consider this. English, although a PIE group language, is actually descended from two distinct branches, the Teutonic and the Romance. (That's why English spelling is so hard. Almost half of our words come from low German, Anglic, Danish, etc. and present a Germanic spelling, while almost half come from Latin, French, and Norman, and present an Old French spelling.) So, if you have any words from your original 200, that you want to keep, that cannot be rationally derived from your element list, simply declare that they arose from a separate branch or even a separate proto-language. I don't see how this could fail to be fun. [Answer] My recommendation would be to conduct a mock conversation in your head between two speakers who are typical of the culture in question. Some things to keep in mind: * What will the speakers of the language likely talk about? For example, some topics might be used more in a medieval setting (e.g. "ax") than in an outer space setting. Pick a conversation dealing with a common thread of interest. * What speech patterns are the speakers likely to fall into? For instance, Klingons often don't use greetings but get straight to the point, while other species use them a lot. "Hello" may not be one of the most common words, but it's going to be essential. Using this envision, two typical speakers talking about a relatively common subject. Go through it in your head in your native language, and figure out what words you'll need. Many dialogues will have some common features, even if the precise content differs. Again, there will be common speech patterns and shared phrasing. The reason I would choose a conversation over a word list is that the most common words in English may not be the most necessary words in this language. Various factors will influence which words are essential for every conversation (which is why I gave greetings as an example), and which ones aren't. **Frequency is not always the best determination of importance.** [Answer] A man called Mark Rosenfelder has written three well-regarded books on creating a conlang. The one most relevant to your query is [*The Conlanger's Lexipedia*](http://www.zompist.com/lexipedia.html). Among other things it contains a "Fantasy Frequency Wordlist, a 1500-item list of the most common roots from a 1.1-million-word corpus of fantasy and science fiction". Equally important, there is also a material about how to make your word choices and definitions believably **different** from English and/or human languages in general. I confess that I have not put in the hard work necessary to do more than play around the edges of creating a conlang, but I found all three books very interesting to read. The other two are [*The Language Construction Kit*](http://www.zompist.com/kit.html) and [*Advanced Language Construction*](http://www.zompist.com/lck2.html), both of which also have sections dealing with vocabulary building. If you wanted a lighter book, Holly Lisle's [*Create a Language Clinic*](http://hollylisle.com/holly-lisles-create-a-language-clinic/) is an accessible introduction to the subject. It's much less scientific than Rosenfelder's books but gets you started right now. In my experience the paper versions of conlanging books are easier to work from than the e-book versions. [Answer] ## Natural Semantic Metalanguage The [Natural Semantic Metalanguage](https://www.griffith.edu.au/humanities-languages/school-humanities-languages-social-science/research/natural-semantic-metalanguage-homepage) (NSM) is a mini-language of sorts, for which any other language (at least the ones they have studied, which I understand to be numerous) can be broken down into. For example, a translation of the English word "happy" someone X is happy (at this time) -translates to-> * someone X thinks like this at this time: + "many good things are happening to me as I want + I can do many things now as I want + this is good" * because of this, this someone feels something good at this time + like someone can feel when they think like this It contains 56 primitive "words" or primes, from which phrases like the above can be made. Since it is not a full language, these "words" weren't given spellings or anything. It also doesn't have a grammar. If you provide words in your language that correspond to these, you will be able to say anything you need, although it might be long. This is good though if your language is missing some words. [Word List](https://www.griffith.edu.au/humanities-languages/school-humanities-languages-social-science/research/natural-semantic-metalanguage-homepage/what-is-nsm/semantic-primes) [Example Translations](https://www.griffith.edu.au/humanities-languages/school-humanities-languages-social-science/research/natural-semantic-metalanguage-homepage/semantic-explications) Again, I wouldn't base your language entirely off of this, but its a good start and can fill in any holes until you fill them. [Answer] If all words in the language match 1-to-1 to English words, it's basically simply a code for English. Pitjantjatjara for example doesn't have a word that means what the English word `brother` means. Even European languages differ in the contexts the have. If I want to translate the German word `Wahrscheinlichkeit` Polish offers me one choice with `prawdopodobieństwo` according to [Leo](http://www.leo.org/). On the other hand English offers me 8 choices: `probability`, `verisimilitude`, `chance`, `plausibility`, `presumption`, `feasibility` and `likeliness`. English allows to make much more distinctions then Polish when talking about probabilities. On the other hand the English languages uses words like `to feel` or `to be` in lot's of different ways. To be essentially serves the purpose of four terms of the [Natural Semantic Metalanguage](https://www.griffith.edu.au/humanities-languages/school-humanities-languages-social-science/research/natural-semantic-metalanguage-homepage/resources) location, existence, specification and possession. Letting 4 of the 56 most important concepts of a language be represented by the same word seems very wasteful and yet English works fine. This means that your language can also reuse words if you don't have enough words. Depending on the purpose of your language you don't have to add all the word at the start. When you find that you currently can't talk about something that would be important you can just add new words. [Answer] Don't do a general purpose word list, if you are creating your own language, you are probably creating that for some purpose (I am assuming for some book, game or some fictional work). So first create words for sentences that are actually used in your work (that's it, make your work worth, do not spend time inventing stuff that probably you will not use). It is pointless in example making most common 5000 words if you are writing a story of a wizard working in his magic tower using technical names. Also be creative, and re-use existing words that are no longer in use, to regular reader those words will just look like a new language, but at least some of them will have a meaning for an above average person. As a programmer I find in fact there are many informatics-related terms that could be of use in real life, but unluckily most non-pogrammers don't know the meaning of those words (in example: the concept of "cache locality" and efficiency explains why disorderly people is more productive, when I see other's people mess I think "it is just their cache" , but to regular people a mess is just a mess). Also invent some etymology, it should be easy to use few words to make new words out of that, that gives your language a story and make it more realistic. The language depends very much on how its world behave, so be sure to have a very realistic world, try to figure out possible situations on that world, take example from authors that already tried to do that and find out fallacies and strong points in their languages. the language evolve in the context, for example for most farm's animals we have different names for babe, male and female versions, while for animals outside farms we have just a unique name, that's because of our past working in farms). [Answer] I apologize in advance because I feel this would be better suited as a comment, but I don't have the requisite reputation. I think all the other answers are great, but I just want to add another consideration that I used myself on my last conlang and found really helpful. If you consider semantic domains in vocabulary generation, you'll much more easily avoid remapping English (or whatever your preferred language is). I used to have a PDF that had several dozen semantic domain webs that covered lots of basic vocabulary and prompted more obscure words too, but the link's dead now and for the life of me I can't find a good replacement through some cursory googling. But I'm sure if you do some searching of your own you can find some good basic examples to look at. Essentially what this entails is you have a web of related concepts, and different languages will assign different lexemes to different groupings of these concepts. For example, in English we have: cloud, fog, mist, steam, smoke; and without bothering to look up their etymologies, those words all look unrelated. Looking at concept webs like this might help you think about whether you want one word to cover "cloud" and "fog" but have two different words for steam from boiling water and steam from warm water (such as at a hot spring in the winter). I wish I had ready-made semantic domain webs or maps to link you to, but I'm finding it hard to find anything better than generic examples. As a supplemental tool, though, I think it's something that shouldn't be too hard to make on your own in your native language just to use as a jumping-off point for vocab generation. I don't think you'll hit 10,000 words like this, but I can personally attest that it can improve your generation rate significantly for your first several hundred words once your get yourself in the habit of immediately considering all the conceptually related lexemes for each basic word. You might collapse some into one word and add extra distinctions for others. It is kind of mind-boggling how many different words humans employ for things that are barely different. (Of course, if you make a hyper-polysynthetic language, maybe you just need one root per domain!) [Answer] When inventing a language you are basically a language learner (of your own language). You have to figure out which words are needed to make use of the language. Therefore I suggest that you don't reinvent the wheel but have a look what others did already in this field. Your world is the typical **late Roman/early Medieval** style? Then a Latin or Greek learner's vocabulary would be perfectly what you're looking for: It contains normally between 1500 to 5000 (depending on the level) very common words ranging from daily life (e.g. food names, trading, etc.), political life (e.g. "career", "bribe", etc.), religious life (words for "temple", "rite", etc.) to military life (e.g. words for weaponry and other warfare equipment). Your world is rather **steampunk**? Then a late 19th century French-English or English-French learner's vocabulary might cover what you need. These are hard to get, I know, but chances are that <http://www.archive.org> or <http://books.google.com> host some scans. Otherwise check antiquarian shops (all types: books, furniture, etc.). Such books are normally of rather little (monetary) value, so they shouldn't cost you too much. I bought a 19th century French dictionary for as little as 8 CHF (ca. 8.50 USD). If your world is **sci-fi**, then a modern-day language learner's vocabulary would suffice. It contains daily life termns, technological terms, etc. That method helped me a lot creating my first few languages. Learners' vocabularies (and grammars) always cover perfectly the basics to make a language usable. [Answer] mostly a summary of other answers: 1. invoke the [yagni](https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it) principle and only invent words as you need them. simply add them to the dictionary as you invent them for your story dialog. 2. you will need to invent both vocabulary (words) and grammar (e.g. sentence structure) in order to create a truly unique language (rather than just an english word codebook). 3. you will probably want to invent roots, conjugations and declensions (e.g. prefixes, vowel-shifts, suffixes) in order to make a realistic and coherent vocabulary. a good [introduction to linguistics](http://ocw.mit.edu/courses/linguistics-and-philosophy/24-900-introduction-to-linguistics-fall-2012/lecture-summaries/) will give you an idea of what is possible. 4. in addition to the language, you will probably want to think about the [writing system](https://en.wikipedia.org/wiki/Writing_system). critically, [phonetic](https://en.wikipedia.org/wiki/Phonetic_transcription) vs [non-phonetic](https://en.wikipedia.org/wiki/Logogram) and [ligatures](https://en.wikipedia.org/wiki/Typographic_ligature). 5. seek the advice of someone who has actually accomplished what you are trying to do. e.g. tolkien wrote a book ([a secret vice](https://en.wikipedia.org/wiki/A_Secret_Vice)) about inventing languages. [Answer] As usual for this type of questions, the usual disclaimer. The way you would go about creating a language depends severely on the purpose you want to put it to. If your goal is to just put a couple of alien-sounding words in a work of fiction, you can just invent them as you go along. If you want a conlang to communicate in, you can go by the frequency list - it would be more of substitution code then a language. If, however, your aim is to create a language that is semi-independent from the work of fiction you write, I'd propose to go another way about it. I will draw now on both my expirience of working with Natural Language Processing and hobby interest in Tolkien's languages. First, you need phonology and grammar, in whatever order. If you are creating a lifelike language from ground up, you are going to work with roots, not with individual words. So, before you go there, you need to figure out, what phonemes you have in your language, what are the phonetic rules working in it. You need to understand which speechparts you have and the way the root can be converted to another speechpart. Roots come next. I would recommend to use not frequency list, but [Swadesh list](https://en.wikipedia.org/wiki/Swadesh_list). The words on the list would be most archaic - and that means a lot of things. First, going through this list, you can make corrections that would be important for your setting and the people that speak this language. Maybe they have no gender roles and didn't have them since the very beginning of the species - then they won'd have separate roots for man and woman. Another important thing of the archaic roots would be that they will be mostly irregular in conjugation and declension. When you will be past those steps, having the basic grammatical framework in place, phonetical laws and basic (Swadesh, not frequency) vocabulary, you will have the feel of your language, it's rhythm and cadence, understand the way the phrases are built, etc. Now you can go on filling the gaps in your dictionary as neccessary by writing texts in that language. A nice bonus to a way of constructing the language this way is that you can apply the laws of glottochronology to it to create related languages of different degrees of separation - that is more or less what Tolkien did with various branches of elvish languages. [Answer] One possibility is to take a real language completely foreign to you (that you don't know), then learn it. (e.g. those learn-language-on-tape type things) However, every word that you learn from that language, substitute your own word. A few drawbacks I know, e.g. 1. You won't get a proper etymology and therefore words that "should" sound similar won't. (Though you could modify with respect to your world's history & culture) 2. You'll have to live with the same sentence structure as the "factual" language 3. You may end up just coming up with ways of asking directions to the beach ;) [Answer] I have a better idea for you. How about you add a word when its needed! So say your writing a letter to your girlfriend, and you need a word for love, make one then! That way you don't have to worry about having to create thousands of words on the spot and not use them ever again. Because remember the most frequent words aren't your most frequent words! ]

[Question] [ Shapeshifters are creatures which are able to, based on will or some sort of external stimuli, change between different forms while still remaining the same individual. Sometimes they retain the same personality, sometimes the different forms entail different personalities as well. A common example from fiction, which I'll use for the purposes of this post, is **werewolves,** but a good answer would ideally apply to other types of shapeshifters as well. Though exceptions both ways exist both in terms of individuals and subspecies, an [adult gray wolf normally weighs around 35-40 kg](https://en.wikipedia.org/wiki/Gray_wolf#Anatomy_and_dimensions). Human body weight obviously varies a lot, but taking [this BMI chart](https://en.wikipedia.org/wiki/File:Body_mass_index_chart.svg), a mid-range human 175 cm tall should weigh around 70 kg; a 40 kg adult human of virtually any height would be considered anywhere between simply underweight and grossly underweight. A 70 kg gray wolf would qualify as *huge* in our world. Let's ignore the skeletal shifting and such for now, and **focus on the body mass.** Let's also mostly ignore the rate of change of mass. (If an answer addresses these, great, but it's not required.) A wolf changing into a human would **approximately double its body mass,** assuming it is a fit but not excessive weight in both forms. When it changes back into wolf form, that same **half of its body mass has to be shedded.** **Where does the mass go, and where does it come from?** (Depending on which side of the shift has the larger body mass.) I realize that shapeshifters don't really lend themselves to hard-science explanations, but I would prefer answers which have at least *some* degree of believability beyond "magic by fiat by author's decree". [Answer] If you're looking for a more general method which ditches biological systems and uses Von Neumann machines, see [gethubphagocyte's (now known as trichoplax) excellent answer](https://worldbuilding.stackexchange.com/a/452/79). Otherwise: First of all, we've got to establish that mass is not created nor destroyed (unless your werewolf is partially antimatter and your untransformed human has a way of handling astronomical amounts of energy) to work within physics. Additionally, I assume you wouldn't want a general change in density, since a gigantic monster that used to be a little kid wouldn't be very effective if it just started to float into the stratosphere. ## No density change: This means we're not actually gaining/losing ~~weight~~ (let's call it mass; since that's what I assume you really want to know), we're just getting or dropping more mass. The generally established way to do that is through the digestive system, so that's what I'd suspect is the best way to start. Werewolves already are known to have the ability to heal upon transformation (I think, I'm not very familiar with them), which hints at a temporarily supercharged metabolism and actually gives some amount of consistency to this theory. What if upon shapeshifting, they begin to eat ferociously as the creature's body kicks into overdrive, rapidly growing/expanding new parts while absorbing others (a mechanism which is already seen in [special tragic circumstances][s]). This would also explain the way that a shapeshifter could reduce their mass, through abortion and eventually excretion, however, it would take a measure of time greater than the few minutes/second associated with shapeshifting. You could say again, that the body starts to act very rapidly, and absorbs/sheds the unneeded parts quickly, a process which I suspect would be rather painful as well as leaving telltale refuse where it occurs. ## Density change: Now, if you didn't mind a change in density, different body parts could be destroyed and recreated in lighter forms, such as muscle turning into fat, bones hollowing, large airsacs filling space, etc. It'd lead to some interesting anatomies, and depending on the intelligence of the shapeshifter, could be deliberately used to exploit odd effects (floating/sinking, whatever). Still, there'd be limits on the range of forms which could be assumed by the shifter, since you can only distribute so much mass in so many ways while keeping a functional body. Additionally, you'd have to worry about some minerals which are used in some structures but not others. Calcium comes to mind, as while you could turn muscle into bone and vice versa, the fiberous muscle bits wouldn't be used, and the bones would be brittle and generally useless. The shifter could have a unique body arrangement which would keep superfluous minerals and elements stored for use later, or it would have to seek out particular foods during the transformation - quite an interesting plot device. ## How? As for the process itself, the creature could turn into an amorphous blob of undifferentiated body tissue with maybe only a brain floating in the center to direct it all. It could form a chrysalis-type structure to protect itself while transforming - getting lots of nasty microbes strewn throughout your future body is probably going to kill you before the monster hunters do, especially if your immune system doesn't expand to fit your new body. My personal favorite is a rapid growth that leaves the shifter wracked while parts of their body start to degenerate and clot while others start to enlarge or grow, some falling off or just drying up while excess blood and fluids gush out, possibly layers of skin and body tissue falling off while the new body grows inside. Eww. As pointed out in the comments, the brain would have to be resized/reformed as well, which would make it so that it's quite possible different forms would have different personalities and memory bases. As well, it's also probable that some memories would be lost during each transformation, so that when the shifter changes and changes back, they'd have partial permanent amnesia, made worse with each transformation. There's a high chance that between that, an insatiable drive to start eating before blacking out, and waking up in a pile of raw body parts (also monster hunters in pursuit!), quite a bit of crazy would happen. [Answer] To add to the magically plausible answers that githubphagocyte and kikjezrous have submitted, I offer the possibility of atmospheric exchange. At at basic level, a body - whether human or wolf - is made up mostly of Carbon, Nitrogen, Oxygen and Hydrogen, plus some other trace elements. It is a fact that the air both these creatures need to exist is composed of Nitrogen, Oxygen, some carbon dioxide and some water, amongst other elements and compounds, containing a lot of the additional elements that is needed. A somewhat less delightfully disgusting solution than kikjezrous' would be for the mass difference to be accounted for by exchange of the relevant elements to occur with the atmosphere and anything else the shapeshifter is in contact with, such that when a shapeshifter transforms into a larger form, mass in the form of the relevant elements is scavenged from the surrounding air (and probably also the ground), and when the shift occurs in the opposite direction, mass is released back into the air and/or falls to earth as dust or sludge. Since a larger changed form may well be lacking in certain elements, this could explain the hunger shapeshifters are said to experience on transformation - they are looking for extra elements to compensate for the deficiencies their transformation has left them with in addition to replacing the energy required to fuel the transformation. Too many fantasy novels seem to ignore the fact that there is *stuff* all around, that the characters don't just exist in the vacuum of space. [Answer] If you're looking for a biological explanation of an actual human transforming into an actual wolf, see [kikjezrous's excellent answer](https://worldbuilding.stackexchange.com/a/451/109). Slightly more realism can be gained if you are prepared to sacrifice the fact that the two animals are real biological animals. If you can build a story around something that can look like a human, and look like a wolf, then you could have a creature made up of a multitude of tiny creatures working together to form the shape of the animal to be approximated. These could be tiny robots, or even some kind of insect colony evolved or bioengineered to simulate other animals. With either of these approaches, not all of the animals involved in simulating a large animal need be involved in the making of a smaller animal. If they are small enough to go unnoticed or even small enough to be completely invisible then half of them can simply wait nearby while the other half of the colony forms the smaller creature. This would allow for any range of sizes and masses, limited by the total mass of the colony. Anything smaller than that could be approximated and for creatures smaller than half the colony, more than one of them could be modelled at the same time. This would allow for a human breaking into two parts each of which becomes a wolf, each of which could also split into a flock of birds or a swarm of locusts if necessary. Although this seems more flexible than the biological approach, and you might get away with portraying it that way in a story, this still isn't a true scientific approach as the same limitations apply to nanotech as do to biology. The smaller you make the component creatures the slower they will move and the shorter the distance they will be able to cover without running low on energy (even if they are tiny robots). You can solve the mass problem with either the biological approach or the nanotech approach, but in either case that doesn't solve the speed of change problem. The biological approach probably involves a human going into a cocoon for a few months while the tissues are reconstituted into a wolf. The nanotech approach probably involves the human evaporating into dust and a wolf slowly crystalising over the course of at least hours and probably days, and even then only with a good source of power (moonlight probably wouldn't be up to it...). [Answer] I've seen two solutions that aren't strictly scientific (because no shapeshift that extreme is), but at least don't violate mass conservation: 1. Eating. If you can transform your own tissue, you probably can also transform tissue you have in you, by any means. For example in your stomach. Fresh mammal like rabbits, or cows, or even rats, would work best - require least alterations. 2. Direct absorption. If magic field transform things, but does not require them to be too similar, your fox would just dig into a hole in the ground, and leave human-shaped recess in it. 3. I said two, right? But closest to what you want and still scientific is what some fish, frogs and octopuses do. Puff up. It does not change their mass, does not make them stronger, but make them **appear** larger. And just by the way, best real life shapeshifter we know is [mimic octopus](https://en.wikipedia.org/wiki/Mimic_octopus). But other octopuses are pretty good, too. [Here is an example](http://www.dogonews.com/2015/2/9/video-of-the-week-can-you-spot-the-octopus) of puff up and skin alterations in real life. [Answer] Has anybody thought the mass to change is already inside the body. Perhaps werewolves and other shapeshifters like them store special cells similar to stem cells that when shapeshifting, possibly through a complex metabolic process, quickly morph into the appropriate tissue thus making them more cellularly dense. This also means they probably weigh more than a human of the same size. As for the craving for human flesh, I don't know. Maybe human flesh is like drugs to them or something [Answer] So long as you are happy with the creature drinking lots of water to fill up bladder like structures and then releasing it on transforming back. If suitably placed these could change the body shape too. [Answer] I found 3 perfect ideas to explain the mass of a shapeshifter: # *Ouroboros* - [Hemlock Grove](http://hemlockgrove.wikia.com/wiki/Werewolf) This method is better to explain mass loss but can be used in both ways. When the user decide to transform into a smaller being he left behind his transformation a mass of fresh flesh (remants of their last body) that he can eat later to turn back to his normal body. [This video](http://hemlockgrove.wikia.com/wiki/Werewolf?file=Hemlock_Grove_Werewolf_Transformation-0) shows the transformation in the serie. # *Steam condensation* - [Shingeki no kyojin (Attack on Titan)](http://attackontitan.wikia.com/wiki/Power_of_the_Titans_(Anime)) and [this](http://attackontitan.wikia.com/wiki/Titan_(Anime)) Well, in the serie isn't explained how transformation happen but fans have made a lot of theories. This method is better to explain mass increase but if you want you can do the opossite effect. When the user decide to transform it release an energy blast, fans believe that this persons absorbs the molecules of the air to make their bodies. * This explain why after the transformation their bodies are so heat, chemical reactions usually produce heat. * This transformation doesn't need nutrients to work, only air (maybe earth?) and energy to make "*the transmutation*". + Because they would need a lot of food to get the energy they could use solar light. In the serie **titans** need light to move or regenerate, in dark they "sleep". # *Virtual matter and teletransportation* - [Ajin](http://ajin.wikia.com/wiki/Invisible_Black_Matter) I don't remember if it is also a fan theory or not. In Ajin there are some persons who can't be killed, if you kill them (e.g: split in two) after a few seconds one of the 2 part would regen in almost 10 seconds while the other would desintegrate (teletransportation? maybe...). This doesn't break matter conservation law (but yes momentum law, or I think...), but you want to make matter so this won't work for you. They can make a creature of virtual matter. Virtual matter isn't like normal matter, **is** normal matter **WITH** one exception: virtual matter was made out of nowhere -breaking law of conservation and other laws- so virtual matter need to be desintegrated in really short time to "don't break these laws". Think that the universe is a human, if you break a law, it punish you (I am not sure but I think a black hole would be spawned of nowhere if you break a physic law). Humans are living beens, and like animals can make mistakes, if you make something wrong your boss/teacher/parents would punish you but not instantly, maybe they take a few seconds or minutes to realice of your mistake. The universe is the same but it doesn't need seconds or minutes, it take yoctosecond (10−24s). By some [*insert magical or sci-fi reason here*] they are able to delay this and they can make virtual matter for some hours (e.g: in Ajin IBM can be used by 5 minutes). * You don't need nutrients. * You don't need solar light. * Maybe you have only this two disadvantages: + You can't stay to much time transformed. + You need some coldown time. [Answer] Shapeshifters are made out of omnicytes. 1 cell that performs all functions. Omnicytes would have to be synthetically made. Evolution does not matter because this would be a lifeform intentionally created by smart people. The omnicytes have electroactive polymer muscles shaped like tendrils originating in the center of the spherical shell. These tendrils attach to the tendrils of other cells and attach in different ways for different effects. A highly ordered dense attachment acts as bone. A different ordering acts as muscle. The cell membrane has a triple layer with the central layer being limpet teeth scales also known as goethite nanofibers in a protein matrix. A higher tensile strength then spidersilk, almost as strong as the strongest carbon fibers. It's hard enough to scrape stone which is what limpets use them for. Depending on the arrangements they can also have exceptional compressive strength. Most biology is predominantly water. Have 1/3 the water and you get 3 times the density. Fat is low density. If a thick viscous fluid acts as energy storage and an oily thing for the cells to move around in, then most of the fat storage can be done away with further increasing density. Hydrostatic skeletons in nature are not very strong, but artificially created ones can be very strong very stiff. Instead of blood have a body wide lung to transport oxygen. A small lung thingy is still needed as a pump. Thingy is a very sophisticated technical term. So the shapeshifter always has the same mass, minus eating and defecation. It just alters the density of it's body depending on cell arrangement. In the smaller form it would be stronger and tougher then in the larger form, but the larger form is more intimidating and with longer legs would be faster. Basically it's biological utility fog. If you want it to be cybernetic stuff just do the same as above but have it be inorganic microbots instead of omnicytes. Poop is waste. If it's intelligently designed then it should be able to digest everything completely with the only waste being CO2 water vapor and some salts. The neural network should not be altered. Very short term memory using biological memristors will allow the shifter to temporarily break up it's brain to fit through a fence or a grate but must immediately reform. The blades of mercer are kind of realistic. Not as large, and not as strong, but definitely doable and practical against flesh. Still won't be taking on a tank though. Btw distributed processing like octopus limbs would assist with changing and maintaining shape while preserving memories in the case of getting shot in the head or decapitated. Super absorbent polymer with multiple thin layers of water can be used as an oil sweat thingy to be temporarily fireproof. A human can stick their hand in a blowtorch for about a minute with a thin layer of the oil because the water evaporates one layer at a time. A really cool material. Should also be capable of photosynthesis but cannot survive off sunlight alone unless it's really lazy. There's a reason plants don't move. Creating fire and flamethrower from the hands is also possible. High frequency radio waves can ionize the air to make a plasma flame discharge and ionic wind can direct that in afire stream. Alternatively use methane. Throwing lightning isn't realistic with using a pulsed laser to make a laser induced plasma channel which can be biologically done if the scientist's are clever, but it would probably be nonlethal. Altering the shape of the tiny tendrils on the surface can be used for structural coloration for any color of the rainbow. It can be used to almost be invisible similar to an octopus. Biological radar can be used for telepathy between members though not for ordinary people and can also assist infrared for really good night vision. Spiders have trichobothria which are very tiny hairs sensitive enough to feel photon pressure,the frequency of light, and the mass of 10 hydrogen atoms. Basically spider sense. Should be able to bench press a metric ton. More with bones, but if one has solid bones then no shape shifting. Due to every cell being identical they would have wolverine style regeneration, but only temporarily. Hundreds of bullets would damage an awful lot of cells, but they should only need about 1/10th of their mass to still be healthy in order to heal up the rest. Highly bullet resistant subdermal goethite scales would help, but in the real world there's no such thing as truly bulletproof. Everything above is hard science. It's not hypothetical. It's not a maybe. Everything above is 100% possible if some clever people designed it. You don't have to take my word for it. Look it up. There is so much interesting info on stuff like this. I thought this up as a way to have superpowered vampires using real physics with a reason to drink blood. Goethite is an iron compound and blood has an awful lot of iron in it. A 5'9 female body type vampire would weigh around 360 to 400 pounds just because of the density. Final note. While the above can absorb biomass similar to mercer from prototype, the cell doubling time won't be any faster then 30 minutes and that's pushing it. That wouldn't be all the cells either. About 5% body mass at a time max due to thermal limitations. Some bacteria are faster but they are also far simpler. This is the hard science answer of a 100% realistic synthetic biology shapeshifter that occasionally throws streams of fire and also occasionally shapeshifts into a demonic teddy bear to scare random people in the freezer section of Walmart. Hope this helps. [Answer] Getting unpleasantly into the domain of handwaving magic, but in a firm-science world where lycanthropy is a thing, having them contain a portable hole, bag of holding, or other portal-type thing within them for mass exchange is not unfeasible. In Lovecraftian terms, you could have every cell fo their being contain a tiny portal to the planes of horrors. ]

[Question] [ For a story idea in my head to work on paper, a character has to be able to fluently and eloquently speak a common language, to the point of being able to turn a phrase or make plays on words naturally, but they must not be able to comprehend that same language in written form. Simple illiteracy is an option; very well-spoken people in history could not read. However the world is a near-future, post-industrial dystopia based on present-day Western culture, where the written word is everywhere and you don't get far without at least a grade-school reading comprehension level. That makes total illiteracy less plausible than it would be in an older time period; even with no formal education, you'd learn at least some basic words by necessity, and literacy begets more literacy. I was thinking that a way around simple illiteracy might involve parallel development of written forms of the language; call them "upper" and "lower". Society is segregated by wealth or political power to such a degree that the poor use a completely different writing system, "lower", while the wealthy elite learn "upper" in schools, and while the two systems describe the words of the same spoken language, the basic symbolic concepts are so different that knowing one writing system is no help in deciphering the other (and societal pressure on both sides would preclude either class learning the other system). Reading either one knowing the other might be a similar experience as someone trying to read an English-language message transcribed into the Cyrillic alphabet, or the Arabic or Hebrew or Devanagari, with no knowledge of what sounds the symbols stand for. You might be able to sound it out with a primer of the alphabet in front of you, but that's what it'd take. The question is, does this seem plausible? I realize this is opinionated, but if an answer can give a real-world example of cultures that can understand each others' spoken language but not their written one, that would be evidence this approach isn't so far fetched. [Answer] As a real life example, consider the Chinese writings Pinyin and Hanzi. Pinyin is a romanization of the sounds of the words, while hanzi is the characters like 漢字 \*. Now in the real world, people know how to read both, but it would be easy to construct a world where the lower class is only taught pinyin and the upper class is taught hanzi. This would fit well: Hanzi is considered to be the "real" Chinese characters, while the pinyin is often thought of as just a phonetic spelling to be used when the real characters cannot be written (such as on a qwerty keyboard) \*those two characters happen to be the characters for "Hanzi," because I'm someone who is amused by recursive things like that. [Answer] [Urdu](https://en.wikipedia.org/wiki/Urdu) and [Hindi](https://en.wikipedia.org/wiki/Hindi) are another example of this. The grammar and a large part of the vocabulary is essentially identical between the languages, but the writing in Urdu is based on Arabic and some vocabulary -- mostly formal or poetic language -- is from Arabic and Persian roots. In contrast, the writing in Hindi comes from Sanskrit, as do the corresponding poetic and formal language terms. Someone who speaks Urdu or Hindi can readily converse with speakers of the other language (although they might recognize from certain word choices and/or accent that it is a speaker of the other language), but if they wanted, they could also probably make themselves unintelligible by switching to a very formal register of speech. This multilingual sign demonstrates this. The top line is in Hindi (written in devanagri script) and the bottom right is in Urdu nastaliq script. [](https://i.stack.imgur.com/jDUYg.jpg) (You can see a [direct comparison of the characters](https://commons.wikimedia.org/wiki/File:Urdu_alphabets.png) in wikipedia as well.) Edit: I thought of more examples. You mentioned Cyrillic. This was a script brought into Slavic lands by Christian missionaries, who adapted it from Greek characters. It is hypothesized that a runic script was used by the Slavs before this. People who were educated in the new script would very likely not be able to read the runes and vice versa. How could I forget Japanese? They have 3 sets of characters used in their modern language, plus of course transliteration to Roman characters. They use kanji (adapted from Chinese hanzi), hiragana (for spelling words out in syllables) and katakana (generally used for spelling or foreign words and a few other uses). Foreign learners often start off learning Japanese with transliterated romaji (the Japanese equivalent of pinyin, essentially) and may never progress past hiragana to read kanji. Children start with katakana and hiragana as well. You can also consider that a person who has vision impairment or a disorder such as dislexia might still be highly educated and articulate while having serious difficulties with the written form of language. There are also languages with no native written form, such as Navajo. Finally, you do not have to look back far in history to find a culture where a large group of people was socially segregated and not permitted to learn to read. In the US, before slavery was abolished, slaves were not permitted to learn to read. Some individuals were still able to become strong orators. [Answer] Yes, it is possible. In general there will be a trend towards a single script, as it has huge practical advantages. But there were and are examples of different scripts for the same language. In Germany **Fraktur** was used far into the 20th century. Why? Just because (basically). Sure, it is the same alphabet but a different font. Yet a lot of people find it hard or are even not able to read Fraktur nowadays. Today everything is in Antiqua ("normal" letters). [](https://i.stack.imgur.com/78St5.png) **Cursive** is a different way to write the same alphabet. When "lower" classes first learned reading and writing it was usually with printed letters, not cursive. That was a style used in offices or by higher classes. Different style of cursive can vary significantly, e.g. this is Sütterlin which was used for a few years in Germany: [](https://i.stack.imgur.com/ycwht.png) Both examples are just different ways to render the Latin alphabet. **Pinyin** is a form to transcribe Chinese letters with the Latin alphabet. It is so useful for learning Chinese that a lot of learners just learn Pinyin and speaking but not reading or writing Chinese letters. Oh, and while I am at Chinese letters: There exist two types of Chinese letters, traditional and simplified. They are still quite similar but different enough to confuse readers. Mandarin Chinese also has the **Zhuyin** or **bopomofo** phonetic transcription system that is commonly used for text input on computers in Taiwan but not Mainland China. Phonetic alphabets, notably the **International Phonetic Alphabet**, abstract from the underlying language. In theory you could read and pronounce a language just by using the IPA. Some "tourist dictionaries" use a simplified phonetic alphabet (based on the normal use of the source language) to achieve just that. [](https://i.stack.imgur.com/Z6J5W.png) So it is possible to have different ways to write one language. Social segregation also is a possibility. [Answer] I am surprised that nobody mentioned Braille so far. It's an obvious contender for a script that can be read by a subset of people with little overlap to those reading the corresponding printed scripts. [Answer] What you describe (a single language with two scripts, used simultaneously) is plausible and has existed occasionally in history, although as others suggest the "steady state" tendency is towards a single script per language for practical reasons. For instance, the Bosnian language can be written using either a Latin or Cyrillic script, and being able to read one doesn't imply an ability to read the other. Per Wikipedia, there are regional preferences as to one vs. the other, with some overlap. There are also historical examples of languages changing scripts, typically for political reasons, which could plausibly create a generational split with older people preferring one script and younger people using a different one. E.g. Azerbaijani was written in an Arabic script until 1929, a Latin script from 1929–1938, Cyrillic from 1938 to 1991, and Latin (but not the same as 1929-38's!) from independence in 1991 until today. Each transition doubtless involved some people making the switch more slowly than others (and at least in the early 2000s there was a fair amount of public signage in both scripts). For two scripts to remain in use indefinitely within the same population there would need to be some significant social force or pressure working against the tendency to prefer one or the other universally in the interest of communication. (And in not having to have twice as much public signage, etc.) But at the same time the separation between the users of each script couldn't be too great, or else over time the underlying languages would separate into different dialects, with the scripts being associated with one dialect or the other. [Answer] There is a real world example which might be even more fitting than Chinese (Pinyin vs. Hanzi where native speakers usually know both): The Hungarian runic alphabet. It is completely different from the Latin alphabet, is written right-to-left, and is not completely mapped to the Latin alphabet (it's more compact, many symbols require 2 or 3 characters in the Latin form of the written language). It fell out of use around the 10th century, but was still used in remote locations until around the 15-16th century. This means that there was half a millenium where parts of the population spoke the same language but used a different script. Most native speakers today cannot read it at all, but there are enthusiasts who learn it, and there are still works of literature published using the runic alphabet. In contrast with other runic scripts, whose languages are dead, the Hungarian runic alphabet can still be used perfectly with the contemporary Hungarian language and grammar. Also, the the Hungarian Scout movement teaches this script, so many boy/girl scouts are fluent in it, although the general population isn't. [Answer] In Ancient Egypt there were several scripts that were used to write the language - the Hieroglyphics, the Hieratic form and the Demotic. Their usage varied with times but primarily the former two were used for religious purposes - hieroglyphs went on stone walls and stelae, hieratic was committed to papyrus. Demotic was chiefly used for writing down administrative matters. [Source.](https://en.wikipedia.org/wiki/Writing_in_Ancient_Egypt#Hieroglyphic_usage) The Turkish writing system [underwent a transition from Arabic to Latin in the early 20th century](https://en.wikipedia.org/wiki/Turkish_alphabet#History), very few people can nowadays read Turkish in its older form. Consider also the Norwegian language which has two official, written forms - Nynorsk and Bokmål ([source](https://en.wikipedia.org/wiki/Norwegian_language)) that each carry specific political connotations. [Answer] As a **real world example** just as you describe. Well, In Persian (Farsi) which is written using a derived version of Arabic alphabet, we have great number of Iranians living abroad in Europe and US who don't know the Persian Alphabet but have learned to speak the language from their parents. When writing, these people use English Alphabet to create a form known as (informally Fingilish = Farsi + English) which was also used on Qwerty keyboards without Persian alphabets. So for example these two sentences are read alike and are just the same. * سلام دوست خوبم * salam doost khubam The case is that many native Iranians who are not familiar with English aren't able to read the second one and also the people living abroad can't read the first. So this situation totally matches your scenario. There are people in between too who are familiar with Both alphabets not necessarily fluent English. In fact to read the second form you just need to know the sounds of the English Alphabet. And I suspect this situation would also be the case for Arabic and other languages with totally different form of Alphabet compared to English making it a common issue. **They can speak together but they can't read the other's writing** [Answer] Sure. Many indian languages have similar *sounds* but very different scripts. Malayalam and Tamil are probably the best examples here. The two languages are *barely* mutually intelligible - some different word choices but enough that we understand ~50-70% of someone might be saying. However a simple word like dog.. നായ് in malayalam (pronounced nāy) நாய் in tamil, also pronounced Nāy So... as long as the sounds linked to letters are similar, its entirely possible to do that. [Answer] Up through the first half of the 20th Century or so, German had a system of script (handwriting) which differed from other European languages' scripts, and was not mutually intelligible with them although it could be learned in an hour or so. Fraktur is simply a typeface, what we would call a font in the internet age, and not a separate alphabet. If you can read this, you can read Fraktur. Tibetan has two systems for what we would call printing, U-Chen and U-Med. With the exception of some letters, they are mutually unintelligible, but knowing one, you can be taught the other in a day more or less. Tibetan script, on the other hand, is a separate study and while based on the other two, looks like gibberish to the untrained eye. Chinese had until 2004 a syllabic writing system solely used by women in part of Hunan Province, called 女書. Mongolian since the 13th century has had multiple mutually unintelligible alphabets. So the answer to the original question is an emphatic "yes". [Answer] > > while they describe the same phonemes of the same spoken language, the symbols are so different that knowing one is no help in deciphering the other > > > This seems to be based on the assumption that the different writing systems are both [phonemic](https://en.wikipedia.org/wiki/Phonemic_orthography). In this case, I would expect learning Upper to be comparably easy, even if there is no letter-to-letter correspondence between the different writing systems due to [multigraphs](https://en.wikipedia.org/wiki/Multigraph_(orthography)) and other features. I have made two experiences in this direction myself: * I am German and it took me hardly any time to learn reading fraktur. If you want to try yourself, [here](http://unifraktur.sourceforge.net/en/) is a website in fraktur and English, [here](http://unifraktur.sourceforge.net/Nightly/Dokumentation_en_fraktur.pdf) is more material. (Disclaimer: I am involved in this project.) * I recently read *[ˈÆlɪsɪz Ədˈventʃəz ɪn ˈWʌndəˌlænd](http://www.evertype.com/books/alice-en-fonipa.html) (Alice’s Adventures in Wonderland* in the [International Phonetic Alphabet (IPA)](https://en.wikipedia.org/wiki/International_Phonetic_Alphabet)), i.e., a book written in English and a completely phonemic writing system. This is not exactly comparable to what you propose as some IPA letters are taken from the latin alphabet and have the same phonetic value as in English, but there are sufficiently many deviations to give you some idea. I could read the book mostly fluently after a few pages. If you want to experience your proposal yourself, Evertype published several renditions of *Alice in Wonderland* in exotic writing systems for the English language, some of which share no letters with the latin alphabet: [[1](http://www.evertype.com/books/alice-nyctograph.html)], [[2](http://www.evertype.com/books/alice-en-Ewel.html)], [[3](http://www.evertype.com/books/alice-en-Shaw.html)], [[4](http://www.evertype.com/books/alice-en-ingspell.html)], [[5](http://www.evertype.com/books/alice-en-Dsrt.html)], [[6](http://www.evertype.com/books/alice-en-unifon.html)], [[7](http://www.evertype.com/books/alice-en-dyslexic.html)], [[list](http://www.evertype.com/carrolliana.html)]. So, to address your question, I do not think it’s that plausible (depending on how strong you want the effect to be), if you insist on phonemicity. To address this, I would render Lower an entirely phonemic writing system and Upper a mostly unphonemic one, i.e., even worse than English. As a historical background, think of English not only having gone through the [Great Vowel Shift](https://en.wikipedia.org/wiki/Great_Vowel_Shift) but also a comparable consonant shift. [Answer] Other answers have mentioned Chinese. I'd like to point out the modern standard [*pin yin*](https://en.wikipedia.org/wiki/Pinyin) Romanization that's commonly used for typing, too. Everyone here on this English board can read "Beijing", but typing those same letters in the IME produces *north capital*: "北京". Now my mother-in-law can’t type on a computer because she never learned pin yin, and her accent doesn’t match the people who came up with the transcription. She learned an earlier form of phonetic instruction (I suppose it would be [this one](https://en.wikipedia.org/wiki/Bopomofo)) which is not roman-based. It’s fair to say that most Mandarin speaking people younger than 60 would find this unintelligible. An example in History is [Linear B](https://en.m.wikipedia.org/wiki/Linear_b) script. [](https://i.stack.imgur.com/f45QM.jpg) Imagine the surprise of the scholors figuring it out when the language turned out to be *Greek*! The point to remember is that a *writing system* is not the same thing as a *language*. Rather than simply different ways to draw a letter (making them hard to recognise), you have real differences between an idiographic or syllable based script and a phonetic script. Another thing is moving from an "artistic" scheme such as [Myan script](https://en.wikipedia.org/wiki/Maya_script) to something more familiar to us. Myan "letters" are not written in a row but are combined into squares. [](https://i.stack.imgur.com/JiyVO.png) [](https://i.stack.imgur.com/EV46g.png) [](https://i.stack.imgur.com/8thHo.png) Furthermore they make a point of not writing the same letter the same way twice, which confused those who tried to read it later. In the above illustration the same word is shown 3 times! There are certain graphic features that determine which meaning it has, but you have artistic freedom to represent the needed features in some drawing, and each block becomes a unique work of art. So, a culture with a rich history of this kind of system may switch to a plain pedestrian system of letters that are minimal icons of the needed features (not a picture containing them), always the same, and set in neat rows, perhaps in conjunction with the advent of movable-type printing. Even with the words and "letters" being the same, it would take quite a different mindset to read the old stuff. --- # in fiction Here's some concrete examples of what you might use. This is *far* from simply different ways to write the same characters. The historical writing system is more like Myan than anything we use today. Glyph-patterns are made from design elements, not specific renderings. E.g. * 5 outward pointing points symmetrically arranged, like a star. * a large round shape on the left and two smaller rounds stacked vertically to the right * a wedge shape (open triangle) with small things inside A scribe/artist would draw an artistic rendering *incorporating* the features, in a mini-mural where the order of finding the features is led through lines of composition and the context of the scene. For example, a pictorial of a river going through the kingdom will look like a sketch, but actually encode specific details of the story, which concerns the kingdom along the river. What started as a clever way of including phonetic information in pictorial art to "speak the picture" evolved into a writing system that looks like Myan. A "character" is never drawn the same way twice, but you can find the meaning based on whether it's pointy or round, symmetry or lack of, number of elements, etc. Larger scale order and arrangement act as modifiers for tense, imperitive vs question, etc. Over time, a large collection of syllables were pared down to a phonetic system, but it was still drawn with "elements" not glyphs. Merchants and accountants have their own ideas and made *stale writing* for journals and ledgers. A 5-pointed star became the *glyph*, etc. With simple essential line drawings used as a prototype for the pattern, each drawn in isolation. When it came to inventing printing and mass literacy, they moved to letters written in a neat row etc. like we understand. Just as people study Shakespeare and calligraphy, well-cultured people in *some* subcultures learn the old idea of *elements* and apply the current alphabet and language, but draw them creatively in blocks, or as a form of poetry/art incorporate them into pictorial drawings. Someone who didn't know that would be completely baffled at not even seeing writing (in the pictorial) or think the block form was an unrelated language. [Answer] Another example: [Shorthand](https://en.wikipedia.org/wiki/Shorthand) writing (coming in a number of varieties in itself) is - in my eyes - *totally* illegible even though it is in a way merely a specialized cursive handwriting with a few abbreviations [Answer] Apparently in Vietnam, during the French colonial period, there were FOUR competing writing systems in Vietnam: Chinese writing, a second system derived from Chinese writing, French, and the modern latin-character based Vietnamese writing system. The last of those slowly became completely dominant. (<https://en.wikipedia.org/wiki/History_of_writing_in_Vietnam>) [Answer] A non-reader or struggling reader can be highly eloquent in a language. That is not only plausible, but quite prevalent, actually. One sees this quite frequently in India among the rural landless farmers. Coming to two scripts, a widely spoken language called [Konkani](https://en.wikipedia.org/wiki/Konkani_language) has at least two variations, and is written in multiple scripts. I quote from Wikipedia: "Contemporary Konkani is written in Devanagari, Kannada, Malayalam, Persian, and Roman scripts. It is written by speakers in their native dialects. However, the Goan Antruz dialect in the Devanagari script has been promulgated as Standard Konkani." [Answer] Some other examples that haven't yet been brought up are as follows: The [Dungan language](https://en.wikipedia.org/wiki/Dungan_language) is a language spoken by Muslim Chinese (the Hui people) living in Kazakhstan and Kyrgyzstan. When these countries were absorbed into the Soviet Union, the Soviets engaged in a system of [cyrillicisation](https://en.wikipedia.org/wiki/Cyrillization), converting their existing Chinese-based writing to Cyrillic. As a result, we now have the following names for the language: Dungan (Cyrillic): `Хуэйзў йүян` (Huejzw jyian) Dungan (Chinese): `回族语言` (Hui Zhu Yu Yan) As we can clearly see, the two writing systems are mutually unrecognisable. The [Kazakh language](https://en.wikipedia.org/wiki/Kazakh_alphabets) was also subject to similar cyrillicisation efforts, which resulted in the presence of three alphabets - the Cyrillic alphabet (official in Kazakhstan), the Arabic alphabet (official in China) and the Latin alphabet (unofficially used in Turkey). All three alphabets are not mutually recognisable. A comparison [can be seen here](https://en.wikipedia.org/wiki/Kazakh_alphabets#Text_sample): [Answer] Issac Asimov had a short story called [Someday](https://en.wikipedia.org/wiki/Someday_%28short_story%29). It is set in a future where humans had forgotten how to read and write, they programmed computers by speech alone. The two children in the story want to learn to read and write so they can pass along secret messages to each other. [Answer] Some excellent answers with the Chinese writings and German alphabets. Another line you may think about is the realm of cryptography. It may play well into your story that the upper class are taught methods of quickly deciphering Caesar cyphers and possibly some others nearly as fast. To avoid someone trying to nitpick at the ability of any human to decrypt on the fly, it could be an entirely fictional cypher method... let's call it the Fraktur cypher, just because it seems fitting. It's not likely for something like this to occur in a society, but not implausible either. Just like the Chinese can learn two ways of writing with different characters, one could learn different methods of writing the same language with the same characters. Or, you could ask someone that programs in Java, PHP, or Python to write a simple phrase. [Answer] Plenty of examples have been given, including the ones I could come up with (Japanese, braille, runic). But few have addressed (beyond a simple yes/no) the worldbuilding aspect of this - "is it possible?" (which, in worldbuilding sense, usually means "is this the kind of thing that would make a reader whimper at the straining of their suspension of their disbelief?") I think a class divide is certainly one possible way this could happen, but it need not be higher/lower classes. There could also, as a historically supported example, be religious vs lay writings. The cloistered religious sects develop separately from the common world, so can and have either developed entirely separate writing styles, and even languages; or preserved older ones while the rest of the world moved on. But in the future, perhaps the most obvious division would be a technocracy, with a writing system optimized for computer-based I/O. Consider, for example, chord-keying. If you teach kids chord-keying input from the get-go, it's silly to teach the letters, then the chord-pattern, then require them to mentally map from one to t'other. So you might only teach - at least initially - the list of which combination of the five keys is depressed for each letter/phoneme. Each letter could be represented, then, by a 5-pointed star with some of the points missing. Realistically, though, to prevent linguistic drift, they would need to share a common sent of spoken media (movies, plays, songs, etc), but their written materials would either be unshared, or so trivially translated between encodings when passing between the groups that nobody ever thinks about it. The latter is the most likely, and also a bit of a problem from a narrative standpoint. If the representations are just different fonts for the same codepoints, what's to stop someone just changing fonts in order to read most things. Augmented reality apps to translate roadsigns would also prevent confusion. So, while it's possible that such a divided culture could form, it's not really possible, in a high-tech culture, for a non-shared font to cause any significant division. Illiteracy is a much more believable thing; a subculture (perhaps a technocracy) which has moved past using the written word, would do it. [Answer] Let me add another real-world example: Malay (specifically Malaysian Malay which some consider distinct to Indonesian Malay (otherwise known as Indonesian)). The traditional script for Malay was a modified Arabic script. During British rule, a lot of official correspondence were transliterated into the Roman (English) alphabet. Over time general literature started appearing in Roman alphabet. After independence, the government decided to standardize the Malay language to use regular alphabets instead of Arabic script. The primary reason was typewriters - until the advent of computers (and widespread adoption of unicode) it was nearly impossible to type in Arabic. That's due to how ligatures work in Arabic. So schools standardized to use regular alphabets. So we ended up with a generation gap. My grandfather's generation were mostly fully literate (owing to the fact that being able to read the Quran was considered critical to daily life). But my grandfather couldn't read regular alphabets. On the other hand, since the Arabic version of Malay is of lesser importance, I paid little to no attention to it in school. So I can barely read Malay in Arabic and can't write it at all. So we have two generations: my grandfather's generation who can read Arabic well and my generation who can read alphabets well. Remember, we're still talking about the same language here. And that wasn't the only script change. The very oldest stone carvings in the Malay language were written in a script nobody use anymore. Then Malay transition to Sanskrit script when Hinduism and later Buddhism spread across the Malay Islands. Later to Arabic as I mentioned above when Islam came. Finally to regular Roman alphabets due to the influence of the British, Dutch and Portugese. [Answer] The first alphabet used for writing English was: ᚠ ᚢ ᚦ ᚩ ᚱ ᚳ ᚷ ᚹ ᚻ ᚾ ᛁ ᛄ ᛇ ᛈ ᛉ ᛋ ᛏ ᛒ ᛖ ᛗ ᛚ ᛝ ᛟ ᛞ ᚪ ᚫ ᚣ ᛡ ᛠ Later the alphabet used was: ᚠ ᚢ ᚦ ᚩ ᚱ ᚳ ᚷ ᚹ ᚻ ᚾ ᛁ ᛄ ᛇ ᛈ ᛉ ᛋ ᛏ ᛒ ᛖ ᛗ ᛚ ᛝ ᛟ ᛞ ᚪ ᚫ ᚣ ᛡ ᛠ ᛢ ᛣ ᛥ ᚸ While it's pretty easy to learn to read this, since it's a simple phonetic alphabet that works closely to how English uses the Latin alphabet (though closer to how English first used the Latin alphabet, when it also used Æ, Ð, Þ and Ƿ [and Ᵹ but it used that much as it also used g]) it's not hard to see how someone could be able to read English fluently in Latin letters and struggle with this. [Answer] When I saw this question I immediately thought of Chinese, with its Hanzi and Pinyin, but I was beaten to the punch for that one. But there is an important factor to consider: where do writing systems come from. Most writing systems in use today are copies of other writing systems that pre-date them. The alphabet is probably the most versatile, yet it arose only a couple times in all of history: most alphabets were invented by people who already knew of alphabets. Cyrillic was invented to better represent sounds in the local Slavic languages. Hangul was invented to make writing easier compared to the Chinese characters that were in use. Pinyin was invented to allow standard Mandarin words to be written using the roman alphabet, and to provide an easy way to document pronunciation. The Cherokee syllabary was invented by Sequoyah, who saw Europeans using "talking leaves". The actual invention of writing from non-writing is rare. Thus, whatever motivation there is for maintaining a status quo of dual competing writing systems, it's unlikely that the writing would be mutually unintelligible as a sort of permanent condition, because both writing systems would have had to originate from somewhere, and it strains credulity that they were both independently invented in the same place without influencing each other and converging. Writing systems are usually invented by scholars, they take years or centuries to catch on, they compete with other writing systems from neighbouring regions (consider even the spelling differences between American and British English, or how various countries have switched from the Latin alphabet to Cyrillic or to Arabic or vice versa). In general, with the possible exception of Chinese, anyone who is fluent in a language can usually pick up a new writing system for it fairly easily. Learning the alphabet/syllabary for a new language is usually the very first thing a foreign learner does, after all. Thus, given that writing systems usually come from the elite and work their way down to the masses, and that learning a new one for a fluent speaker is easy, I think it's unlikely that there would be nearly no people who understand both systems. Sure, there are lots of Chinese people who can't really read Pinyin very well, and lots of Chinese speakers who can't read Hanzi at all, but Hanzi, being so difficult, only survives because the elite keep it around. Anyone who knows Mandarin Chinese, and has 10 minutes in training in Pinyin, or who knows Mandarin and English, could probably learn to read Pinyin text in a few hours. If the rich were using Hanzi and the poor were using Pinyin, any rich person who had any reason at all to write to the poor would have zero difficulty in doing so. You might get more traction if you consider the problem the other way: Chinese characters are often used to write multiple languages. Cantonese and Mandarin are mutually unintelligble, like English and German are. But they both use the same writing system: Hanzi. However, it's common for a written Cantonese sentence to be totally incomprehensible to a Mandarin speaker (not so the other way around, as Mandarin is seen as the "standard", so there is immense pressure on Cantonese speakers to write as if they were using Mandarin). Also, any text written before about 1900 used Classical Chinese, which is similarly incomprehensible to modern readers despite using the same characters. [Answer] Serbo-Croat is generally considered one language. Serbs and Croats understand each other's spoken language - the differences are minimal - but Serbs write in Cyrillic (Russian alphabet), and the Croats write in the Latin alphabet (like English). An exact example of what you need! Except that learning an alphabet is pretty easy, and most educated people can read both, although not with equal fluency. For your imaginary world, you could make both writing systems like Chinese, in which literacy requires learning 6,000 - 25,000 characters, depending on your level of "literacy". That would slow things down. [Answer] Yiddish (written in the Hebrew alphabet) was originally very similar to Middle German; Jews in other areas also developed Ladino (Judeo-Spanish) and Judeo-Arabic. Going back to when literacy was less common, there were dialects of Aramaic written in both Hebrew and Greek scripts. As to why, if you need to learn one alphabet to read religious texts, it's convenient to use it for everything. ]

[Question] [ The question is pretty straightforward: **Why would two species of predator with the same prey cooperate?** I am looking for answers in the following context: * Limited food supply, which means scarcity of prey and food * Non-compatible species of predators which can not reproduce with each other * Localized and small hunting ground, the prey are not widespread and only exist in a small area, the predators can not simply have different territories. * The predators are roughly equal in number and power, and one does not have the advantage over the other - one can not simply destroy the other or consistently scare it away from prey. Any conflict between predators would be non-deterministic and dangerous for both. * The prey can not be taken down easily, and multiple predators are required With the context above, why would they work together? I want them to work together, I just don't know why would they? I have not yet finalized these predators, I am looking for suggestions, or ways to modify or design them so that cooperation will work - maybe something symbiotic? [Answer] Eels and groupers hunt cooperatively. The groupers are good at finding and herding prey but bad at killing it. Eels are fantastic killers but bad at finding prey. To the point they rarely succeed without the other. And they have been show to actively signal the other. [Grouper & eel cooperation](http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040431) [Honeyglider birds lead honey badgers to beehives](http://www.ehbonline.org/article/S1090-5138(14)00087-7/abstract). The birds can easily find the nests but can't tear open the strong hive, the badgers can tear open the hives but can rarely find them. The badger tears it open and eats then the bird flies in and eats its fill from the now open hive. As was mentioned, [humans and dogs](http://www.sekj.org/PDF/anz41-free/anz41-545.pdf) are a classic example: dogs are fast and have good senses of smell, humans have good eyesight and are strong clever killers but fairly slow. Together, they can find prey better and dogs can easily drive prey to humans who can kill it easier than the dogs could alone. Basically, all you need is for your two species to have a different suite of senses and/or physical capabilities. [Answer] Here's some [footage from the BBC](https://www.youtube.com/watch?v=szuchBiLrEM) of [dorado](https://en.wikipedia.org/wiki/Mahi-mahi) and [frigatebirds](https://en.wikipedia.org/wiki/Frigatebird) hunting [flying fish](https://en.wikipedia.org/wiki/Flying_fish). The dorado force the flying fish into the air, where the frigates catch them, the frigates scare them back into the water where the dorado catch them. The two predators are not directly competing as they don't share a medium of movement, and for each the presence of the other makes the hunt easier, as the prey can evade each one alone. [Answer] You can have them work like Badgers And Coyotes. Based on an article found [here](http://listverse.com/2015/02/23/10-amazing-cooperations-between-different-animal-species/) > > Badgers and coyotes share a common predilection toward taking various burrowing rodents as prey, though they catch them in very different ways. Rodents such as squirrels and prairie dogs have no chance of outrunning a coyote, but they can always escape into their burrows. A badger, on the other hand, can dig into the ground and tear a rodent from its burrow provided the rodent doesn’t simply run out of another exit and leave the badger with no hope of catching it. A badger-coyote team could certainly tip the odds against their common prey if two competing predators could manage to work together. > > > [Answer] *Good manners started to happen as soon as all the mammoths were killed off and there was no piece of food big enough for everyone to eat at the same time* (Nanny Ogg's Cookbook, © Terry Pratchett & Stephen Briggs) As long as they can tolerate each other's company and there is a benefit - ANY benefit - to keeping it, the details don't matter as much, and what each thinks of the other - "brother" / "master" / "tool" / "supplier" matters even less. Doesn't have to make sense, as long as it works. Some benefit is had on average, and selection will have done its thing. Even if one side is shortchanged due to food scarcity, such teams might still outperform singles. Some ideas: * one has poor mobility, another has poor offensive power. Think [those crabs that use anemones](https://en.wikipedia.org/wiki/Lybia_edmondsoni), if they hunted live prey * one is prey to something else, which is in turn kept at bay by the "partner", who benefits by having dibs on the food and/or having to exert itself less * one side may be able to utilize scraps the other can't - like sucking out marrow. * one side controls the other - feeding when possible, culling when not. Sad, but this does work even when they are theoretically equal in power. * there are non-combat benefits - like pest removal, threat detection, crafting shelter or traps, etc Further benefits can emerge in an already established partnership. [Answer] If you're looking for a more fantasy like answer, perhaps evolution has driven the two predators into a **cooperative pact** of some sort. Say for example if the primary grazer of the area has, over the millennia, developed an exceptionally thick hide. The primary predators of this animal have included two species with very different methods of bringing it down. One, essentially a large predatory cat, would bring it down through mauling the prey and get the kill through sheer violence. The other, a large venomous lizard, would simply bite the prey in the leg, inject a lethal dose of venom, then just follow the beast until it fell. Nowadays, with the grazer's hide being so thick, the cats take much much longer to take it down by themselves and the risk of getting bucked in the head or grievously wounded has become too high. The lizard too has problems, in that it's fangs has difficulties penetrating the thick outer layer to deliver it's venom. **The solution: These predators hunt in pairs.** Now earning dinner is a co-op game. The cat will typically make the first strike, focusing on opening up a gash somewhere in the targets hide. The moment the lizard senses an open wound, it will pounce in and inject it's venom. Once this is done, both predators retreat to a safe distance and wait for their meal. I don't have too hard of a time imagining a pact like this actually forming through natural evolution, and it could make for a fairly unique bond between the two creatures. Each one may even develop a tendency to try to form a lifetime partnership with the other. [Answer] At the top of the food/intelligence chain, BBC's Human Planet has an interesting section of Humans and Dolphins [fishing together](https://www.youtube.com/watch?v=42MpfPqWkhk) in Brazil. Also one of their other shows (maybe Planet Earth? not sure) has video of sea snakes and trevally (a predatory fish) [hunting together](http://www.arkive.org/black-banded-sea-krait/laticauda-semifasciata/image-G78967.html) in a reef. In both cases, the two predators have complementary skills that are used in conjunction. Dolphins move well in the ocean and like to drive fish up against a beach to make them easier to trap. Humans don't move well in the ocean, but can make nets to trap the fish. Sea snakes can get fish out of tight crevasses, while trevally are fast enough to catch fish that try to scoot away. [Answer] Wolves and Ravens Allegedly Ravens lead wolves to large animals that are too large for the ravens to kill (Ravens can kill sheep). The Ravens then get a share of the spoils. In this instance the Ravens are acting as scouts and improving the odds of the wolves getting a kill and the ravens getting a meal. (See *Mind of the Raven: Investigations and Adventures with Wolf-Birds*) [Answer] Orcas have been known to cooperate with whaling boats][1](https://en.wikipedia.org/wiki/Killer_whales_of_Eden,_Australia). If they are after the same prey but not in competition over who gets what, there is a lot of benefit in cooperation. In that case the orcas would get the tongue and lips of the killed whale and the whalers would get the rest. [Answer] As other answers have suggested, **mutual benefit** is the likely reason. If both species mutually benefit from co-operating (or at least tolerating) each other, the trend of doing so will develop. Aside from complimentary hunting skills, it might be worth mentioning the potential mutual benefit of co-operation **afterwards**. With a scarcity in prey and food you can be certain there will be plenty of opportunists and scavengers, ready to pounce on someone else's kill. And so the pair, instead of competing, take turns acting sentry and guarding the kill to ensure that the other one can eat undisturbed - minimizing the amount lost to scavengers. Over time, both predators benefit from having less of their kill stolen. [Answer] What about a situation where both predators eat/use different *parts* of the same prey, but cannot individually get to them. Say predator A can kill the prey, but for whatever reason cannot get to the marrow (or whatever) that it actually needs. Predator B cannot kill the prey, but is evolved to open the bones and expose the marrow (or whatever) but does not consume the element that predator A needs. That is not a perfect depiction but you probably get the idea. Only if they work together can they both get what they need. You could make it as "magical" as you want too if that's appropriate to your setting... predator A is a hulking dangerous brute that subsists on "life energy" that it cannot properly release from the bodies of the prey, and it must not actually kill them or the life force is lost. It must merely incapacitate. Then predator B, which could never incapacitate the prey on its own, he some mechanism whereby it feeds off of resonances (not the life force itself... perhaps fear?) released during a creature's last moments, which also releases the overall life forces that predator A needs. Can make this as real-world or fantastical as you wish. [Answer] Another way the two species might gain mutual benefit is protection from another species. For instance, you might favour hyenas if they'll drive away the lions and eat less- more for you. [Answer] I see the prey animal as large with a tough skin. Think about a Rhino or a Hippo. Predator A is a semi solitary Omnivore like a bear that only really wants the bones and maybe some other "cast off" parts of the prey animal. I think of Predator A as being large and somewhat slow. Predator B would possibly be more catlike. Sharp teeth and claws and would be more interested in the soft, squishy bits. Maybe Predator B should be a Pack hunter. Either Predator would be able to take the prey animal by itself, but with a lower success rate. Predator A would be able to kill the Prey quickly, but is not really suited to chasing it down. Predator B could easily chase it down, but the tough hide make an quick kill unlikely and would be risky for predator B's survival. Either way the effort required for either predator species is high. Prey animal slowly displaces other potential prey animals, becoming the most likely source of food for the 2 predators. One Day, a pack of predator B realizes that it can herd a large member of the Prey toward the den of predator a. Predator A dispatches the animal without having to chase it. Predator B gets to eat with less effort and risk. Marinate this sequence over several millennium and you have actively cooperating predators. The keys here are that the predators each want something different from the prey, and that the prey be difficult, but not impossible for either predator to take on it's own. [Answer] Probably because the two can do different things better. For example, lets have a really fast spider, that can make large webs quickly, and catch up with it's prey, and a larger, stronger, but slower meat-eating-sloth-thing. The spiders stop the prey, and trap it, and the sloth comes and kills it. The spiders are in danger if they try to kill it, because of their exoskeleton; in Spellsinger, whatsisname punches a giant spider, and it dies from a blow that would only have made a human angry. Another possibility would be if one can catch, stop, and possibly kill the prey, but can't pierce its skin, and the other can't catch the prey, but can carve it. That way, they *have* to work together. [Answer] This has probably been touched on, but the best reason I could think of would be some sort of co-operation. Maybe both predators have different but complementary ways of hunting and they've learned to use each other. If you're envisioning an environment where land and food are rare, there aren't many better examples to use than that of the African desert and grasslands. When you think of this environment, you'll notice that the main prey animals have something in common. They are either very big, very strong, very fast or a combination of all three. This means that they are almost impossible to kill. What does this mean for our predators? Well, there are probably a couple of benefits. ## Overwhelming Numbers One of the best ways to take down large prey is through large numbers. Wolves are probably the best known land example, but you probably didn't realize that Orcas have been known to kill animals as large as blue whales through tag-teaming efforts involving the whole pod relentlessly harassing the larger whale for hours or even days. Maybe your environment doesn't allow for one species to reach the numbers needed to take down prey this way, but having the two species working together gives them the numbers edge. And since they don't need to expend as much effort, sharing their food with another species isn't a big deal. ## Specialized Tools Another benefit could be that each species has a very specialized and complementary hunting technique. Maybe one hunter is very good at killing the prey but lousy at catching it, while the other is great at catching prey but lousy at killing it. Once again it comes down to the fact that when it's easier for each animal to get the food, sharing some doesn't matter as much so long as both are benefiting. ## The Parasite What if neither of those points mattered? Is there still a way you could have two predators eating from the same food source? Simple, make one of them a predator and the other one a parasite. I'm not talking something like worms or ticks, have one of the predators specialize in stealing food from the other one. Maybe they are very quick and strong for short bursts and can follow the other predators around, waiting for them to make a kill before swooping in and stealing the food. Maybe one of them could be some sort of big cat/dog and the other could be a large eagle that flys in and grabs smaller prey whole and chunks of bigger prey. It's not exactly co-operation, but it could make for an interesting story point, especially if both predators are sentient in some way. [Answer] Lions and wolves both hunt in packs to take down larger game they they can handle individually, so cooperation *within* a species is established. The question is how to extend this. If another factor prevented high densities of each of your predator species, the only way to gang up on prey would be to gang up with the other species. Perhaps suitable breeding/sleeping locations are sparse (tree-nesting apes needing big trees, anything needing caves) and the animals are territorial. Alternatively a vulture(-like-creature) could prevent a turkey from taking flight allowing it to be killed by a cat that then shared the meal -- the vulture couldn't strike the turkey on the ground, and the cat couldn't in the air. A similar approach would work at the margin of land and water or air and water. ]

[Question] [ Assume a passenger aircraft were left undercover for a very long period, perhaps thousands of years, in a damp, arboreal environment. How much of it would survive? Which parts would remain intact, and which parts would decay? What would it take to get it airborne again? How long could it reasonably survive for, and still be recognisably an aircraft? ## Edit Assuming that it couldn't be flown, how long could an airframe (i.e. just the metal and glass) last, in less than ideal conditions, without mothballing or deliberate preservation, such that an ordinary modern day person could look at it and be able to easily recognise it as such? It might be an irredeamable wreck, but it would be recognizably an aircraft. ## Futher Edit (context) For those interested in further context about the question, this is in regard to a fantasy novel I'm constructing called The Weapon Child. * [There's a sub on *Reddit Fantasy Authors* here](https://www.reddit.com/r/fantasywriters/comments/4pbn60/critique_the_weapon_child_chapter_25_airplane/) * [The chapter in question can be found here](https://docs.google.com/document/d/1kNWrz6KsGpxD40SPdwfhb4fcwi-TTDQhI_E3IlUU1ps/edit) [Answer] In 5,000 years it would not be recognizable as an aircraft. There are good answers already with respect to the aging of the aircraft proper. But what of the environment? Rain will damage the aircraft by rot and rust. Ice will cause stress, opening small cracks. The weight of ice and snow can cause structure failure and collapse. High winds can lift the aircraft and pull weakened pieces off, or the jarring of the aircraft falling when the wind gusts subside could collapse things too. A flood every 500 years doesn't sound unreasonable, so now its full of mud and debris. Or parts float, other parts don't, and the airframe is stressed. If the water is flowing, parts can be torn off. You get the idea. Nature is a tough place. In addition to weathering, generations of trees and other plants would grow through it, tearing it apart. It would be buried by rotting vegetation and leaves. A fire in the area (once in 500 years does not sound unreasonable) would surely burn away or thin the aluminum sheeting. Remember - after a century, the airframe is full of tinder and it likely sits in a forest. Trees will fall on it. Of course no one would know the plane was there. Otherwise it would have been salvaged long before and utterly destroyed. So the most you're likely to find, if you happen to look in the right place, are lumps of rusted metal buried deep underground in a forest. Or whatever the area looks like 5000 years in the future. [Answer] Your time frame is way, way too long. Aircraft are incredibly complex machines; let's review a few of the failure points. **Fluids:** * Your first failure point is likely to be fuel. OK, technically the batteries would drain out first, but if you have fuel you can get those recharged in most cases. [Your limits look to be around 12 months to 2 years](https://mechanics.stackexchange.com/questions/119/how-long-does-it-take-for-gas-to-go-bad) (jet fuel is probably less). * Hydraulic Fluid. This stuff is under intense pressure and in the course of a couple years those seals are going to fail...now you can't steer, or move the landing gear. * Oil. It goes bad too, but it takes longer, if the oil was perfectly fresh and in a completely closed system it could hypothetically still be good. *All of the fluid systems are going to fail in the first couple of years.* **Electrical systems:** * Wiring is sensitive, any parts not covered in plastic are going to cause you problems...rodents sometimes like wire too...odds are over your time frame something will move in for at least a while. If not, contact points will be the first to corrode. Unattended the wiring is likely failing after 20 years (give or take). * There are a whole lot of systems in a plane, all will fail inside of probably 25 - 30 years. Navigation will be shot (no satellites), air systems for cabin pressure, lights, etc., etc. **Mechanical Systems:** * Over your time frame...nothing survives except perhaps the remnants of a few larger pieces of metal. * Odds are the hangar falls on top of the jet anyway... * Moisture is bad, and persistent. It will get through the hangar roof and eventually make it collapse. Even if it somehow doesn't land on your plane it will allow more water to hit the jet...increasing the decay rate. **In short, there is absolutely no way someone is going to find a flyable jet 5000 years later. Even if the thing were vacuum sealed and stored in a dry underground cave in the desert somewhere it would still not be flyable.** [Answer] When people wish to mothball expensive equipment for possible use later, they perform a specific set of operations intended to remove the most sensitive parts from the environment. F-4 (Phantom) at Davis Monthan AFB [](https://i.stack.imgur.com/qgy39.jpg) Aerial view of Davis Monthan AFB [](https://i.stack.imgur.com/uqoNF.jpg) During mothballing, sensitive equipment like engines and electronics are removed, fluids are drained, and less sturdy equipment (e.g. cockpits) are covered. Airline companies have a similar facility nearby in which they store retired aircraft. The US Navy has a facility for retired ships at which they perform similar operations. The US Air Force Museum's display aircraft are similarly stored. Their preservation is such that by restoring the electronics, engines, fluids, and other components would make (most of) those aircraft flight worthy. I would assume that using these techniques could significantly extend the time that the airframe could be restored to flight worthiness by many decades certainly. However, I doubt if this would extend to centuries. Even if it did, who would know enough to do the work and where would the parts and supplies come from? [Answer] Thanks for the hilarious question. Might I rephrase like: do you know of many buildings or constructions of a couple of centuries old without any kind of maintenance, that is still recognizable? Let alone operational, in case of a machine? Let's look at some examples. You talk about a hangar. Just consider your house. How much wear and tear do you see after say 5 years of no maintenance? Paint falling off. Corrosion, wood rot, dirt. After some 20 years of no maintenance or cleaning, it might well be overgrown with plants. You want to add two zeros? Nothing might be left all. Let's look at climate. Here in Northern Europe, everything might be wiped out by the next ice age, think of an ice glacier of thousands of meters high pushing from the north. Ice ages appear roughly every 10,000 years, and the last one ended about 10,000 years ago, so the next one will most probably be within your time frame of 5,000 years. Then infra structure. A plane is nothing without infrastructure, like runways, communication, trained personel, fuel of a precise composition, and maintenance. Lots of parts have maintenance schedules based on time, like a checkup every month, or six months. Suppose that after some extreme time frame a part may be in perfect condition, e.g. a turbine blade. If it is not checked up regularly according to its maintenance schedule, it cannot be certified for operation. So in case it might "work", it is useless from the point of certification. Who would risk his life just to "try out" if it would fly? I mentioned runways. I remember having seen an asphalt road literally disappeared after being abandoned for some 20 years. How about robbers? I would guess that within a few years the plane would miss essential parts due to robbery. The pyramids prove that even a tough cover will not stand robbery. Nice question anyway. --- Update: Yesterday, I unpacked my old record player. You know, from before the compact disc we had those vinyl records? Now, my record player was wrapped in plastic when I moved, and stayed wrapped for perhaps 20 years. Was it operational? In principle, yes: motor, plateau, levers, pickup element, wiring, hinges, cables, even my self-built pre-amp worked. Only one part failed: the rubber belt between motor and plateau was, hum, melted, or, transformed. It was broken in pieces, and most pieces were like peanut butter, or tar. A few pieces could be lifted and removed, other pieces had literally be scraped away. I did not manage to get all sticky tar and rubber away. Ok, I did get the thing to work with an improvised belt, cut from an old bicycle inner tube, a recent one. But this reminded me of the question about the 747. Just cut the requested timeframe of 5,000 years by a factor of 200 and possibly essential rubber parts may detoriate to a point that it is hardly recognizable. The moral of the story is that you do not want to try such old equipment. I wanted to try the record player because some people here got renewed interest in vinyl records. But why? Records got dust and ticks, and sucked. Compact disc, a huge improvement, sucked too. Digital music on my hard disk, or the cloud, is much better. Same for airplanes. Even now the 747 is considered to be outdated: too much noise and pollution. Let alone after the next couple of generations of aircraft. Even if the old museum stuff could be flown, you do not want that. Really. --- Update may 2021. Middle/end of Corona Covid-19 pandemic. More than half of all airplanes worldwide have been grounded now for about a year. As the severity of the pandemic decreases, air traffic is started up again. Experts warn for technical problems because of this mothballing which was only a small fraction of 5000 years. At 9 january 2021, a Boeing 737 from Sriwijaya Air crashed in the Java Sea (Indonesia) 6 minutes after takeoff, killing 62 people. Experts call as probable cause: storage with no flights for 9 months, and taken back into service too fast. After a period of no flights for 9 months, the plane was inspected, approved, flown from storage in Surabaya to Jakarta on 14 December, and resumed passenger service the next day. After 132 flights, it crashed at 9th of January. See <https://www.nytimes.com/2021/01/13/world/asia/indonesian-plane-crash-mothball.html> and <https://www.telegraph.co.uk/news/2021/01/13/indonesian-airliner-crash-may-linked-plane-grounded-nine-months/> So, even if the plane "looks good" after just 9 months of careful mothballing, it may not be safe to fly. Let alone when it does not look good after being left abandoned in a hangar for five thousand years. [Answer] Plastic hoses, insulation, tires (already mentioned), cable sheathes, anything made of plastic would be useless in such a time frame. I bought a car made in 1960. When I bought it, it was 40 years old, and had literally been driven by a little old lady less than 30,000 miles and kept garaged. Immaculate! I thought it would be a great car. We had failure after failure of plastic parts - brake hoses cracked, door handles snapped off, wires shorted out, vacuum hoses leaked, seat covers tore when someone sat down on them. Finally had to junk it. [Answer] The future visitor will find a layer of aluminum-oxide dust, some metallic copper, possibly some recognizable plastic bits... underneath layers of iron oxide or whatever the building was made of, underneath a considerable amount of earth and vegetation. Careful, high-tech archaeology would reveal the likelihood of a building. The aluminum, and exotic metals in 4 places and tungsten or depleted uranium in one, would hint of being a 4-engine-on-wing airplane. **Flying it would be out of the question.** [Answer] As others have mentioned the plane would certainly be unflyable - working components, plastics and electronics would certainly degrade over that long (most likely even with preservation). However to answer the second part of the question more precisely, given a storage location that did not collapse and was reasonably weather tight the plane could certainly still be recognizable. Think of King Tuts furniture which is over 3000 years old. Even if the structure becomes brittle and collapses you would still have wings lying on the ground beside a fuselage. (For location, I am thinking of an underground airbase if the entrance caved in and left the rest sealed.) [Answer] Supplementary answer. I watched a documentary about a few enthusiasts who wanted to salvage a WW2 plane that had ditched in the wilds of Northern Canada during the war. Their (crazy?) plan was to get it airworthy again and then fly it out using the frozen surface of the lake it was next to as a runway. They almost succeeded. It took several months of maintenance to get the engines running again. Various parts had to be replaced - rubber in particular had perished. Also all the fluids - oil, fuel, hydraulic. Sadly, something caught fire during their take-off run. The pilots got out uninjured, but the fire utterly destroyed the plane. So after 70 years in Arctic weather, a plane is just about capable of being repaired. [Answer] Considering that it has been stored in a dry environment, in a closed place that doesn't collapse in that timeframe, I think that it will still be recognized as a flying object. Think about the [antikhythera mechanism](https://en.wikipedia.org/wiki/Antikythera_mechanism "Wikipedia article Antikythera_mechanism"), that has been at the bottom of the mediterranean sea for over 2,000 years and after a large and meticulous study, using advanced technologies, scientists have been able to establish not only what it was used for, how it worked, and aprox. date of construction of the artifact, but also detect and design the missing parts (and allowing to make a replica that works). > > The Antikythera mechanism is an ancient Greek analog computer and > orrery used to predict astronomical positions and eclipses for > calendar and astrological purposes decades in advance. > > > [Answer] While natural materials like wood and metal might survive 5000 years in a usable state, there is no way any kind of plastic will [survive](https://en.wikipedia.org/wiki/Polymer_degradation) that long. None of the types of plastics produced have thousands of years lifetime (not even hundreds of years) as a product requirement, and even if they had it is not clear that this would be possible to adequately [test](http://www.beatriceco.com/bti/porticus/bell/pdf/plastics.pdf) for. [Answer] There's no way it could survive 5000 years. At this time scales the material diffusion becomes significant, and this will (at least) cause electronic systems death, because some conductors will short-circuit. And without electronics, an aircraft is not usable for flights. Also, we may assume that the temperature will not be constant, so the number of stretchings of the aircraft body will cause severe "metal fatigue" and other destruction. [Answer]      You state that your 747 will be sitting in the hanger for 5000 years. I'm afraid that this won't work - the hanger won't last for that long. While the plane is made mainly of Aluminum and won't rust apart, the hanger certainly will completely deteriorate long before the 5000 years are up, exposing the plane to the elements.       Thousands of years of rainwater pounding against the surface, bits of collapsing hanger, hail, strong winds throwing around whatever debris may be in the area, and any other storms that may or may not happen over 5 millennia will be certain to put holes in your plane. As other answers have stated, all plastics and rubber components will be junk. However, any parts made of iron within the plane that normally wouldn't be exposed to moisture can and will rust over the thousands of years of being exposed to moisture. Another thing to consider is the freeze and thaw cycles, which will pry apart any important moving bits, and pretty much wreck the important systems on your plane.       Essentially, your plane will be an artifact of a long lost era, nothing more than a bit of metal - that, and a home for whatever animals may be living in what was once a gloriously large plane. [Answer] I guess the thing is how "fantasy" is your fantasy novel? No reason why a magic field couldn't have sustained it for 5000 years, or some as yet not invented stasis field. Still, the question makes it sound like you're after realism so maybe that isn't helpful! :-) [Answer] Complicated mechanical equipment degrades with startling speed. A car that has been sitting in a garage for as little as six months probably won't start. After five years, the work of a day can get it back on the road (assuming good tools, fresh fluids, fresh fuel, new batteries, available replacement parts). After a fifty years in a field in a wet climate, cars become an unrecognizable pile of rusted metal. (but aluminum is different) Hangers are usually just a thin metal shell over steel supports. It's unlikely a structure like that would survive a thousand years in a moist climate. I'd expect a normal hangar to be completely erased after a few hundred years in a jungle-like climate. If you're interested in the process of decay here's a bit about the degradation: (shortening the timeframe to 5 years when things start to become problematic) * The fuel needs to be flushed (airplane fuel is less subject to the chemical degradation than gasoline, but after this time I'd expect enough water accumulation you'd want a full fuel system flush before trusting your life to this vehicle.) * Rubber hoses bushings and seals have begun to degrade. After five years the process has started so there are would be minor leaks and failures of rubber components. After a hundred years rubber will basically have turned to dust. (I've had 30 year old rubber crumble in my fingers like ash) * Batteries have leaked and are unusable. (all batteries have to be removed and new ones acquired, leaked acid must be cleaned up, contacts cleaned and sometimes replaced) * New tires. Tires in the landing gear will have gone flat and then been crushed by the weight of the plane (this could happen in as little as six months) * Hydraulic fluid has taken up water and needs to be flushed. Questionable if the systems will still hold pressure after five years. The good news though is that if the hanger was built to last it could maintain integrity. (Think of Buddhist temples that have lasted thousands of years in the jungle). The plane itself being made of aluminum would be recognizable basically indefinitely. Aluminum oxide creates a very strong protective layer which basically prevents it from rusting away. I'd expect to see a recognizable fuselage and wings of a plane even after a thousand years. [Answer] We are of course intrigued by a long-term storage Jumbo Jet, but this the line of thinking would not be much different if it was replaced by, say, a bicycle, over a time frame of about 50 years. It will not be usable too. [Answer] Aluminium has no [fatigue limit](https://en.wikipedia.org/wiki/Fatigue_limit). This means that as the aircraft structure is subjected to many successive loads, no matter how small, it is guaranteed to suffer fatigue and fail. Assuming it isn't destroyed by chemical corrosion as others have rightly pointed out, you must consider the loads to which the plane is subjected over a period of thousands of years. For example, if the plane is stored deep underground the temperature will be roughly constant but on the surface fluctuating temperatures will cause thermal stress, which over many cycles will start to cause failures. 5000 years makes for about 2 million day-night cycles, which should be enough to break off those parts subject to the highest stresses. Being exposed to the elements—snow, wind, etc.—would add large loads and speed the process considerably. My best guess is that the wings may break off, the structure supporting the landing gear may fail and the plane collapse to the ground, the airframe may crack up around all windows, etc. I am obviously not an aircraft engineer so I don't know for certain which parts will be most stressed. [Answer] Also remember that the windows are plastic. Once the plasticine leaks out, they will become very brittle. Then the flexing of the aircraft frame will crack and, eventually, destroy the windows. The wings, unless supported would eventually droop to the ground. The landing gear is pretty robust but it is bolted onto the frame. I think that those mounting points will go. I think that, if you are lucky, after 5000 years, you will have a sagging aluminum tube with holes in it, resting on the ground. ]