q_id
stringlengths 6
6
| category
stringclasses 12
values | question
stringlengths 5
4.6k
| reponses
stringlengths 28
9.92k
| response_number
int64 1
489
|
|---|---|---|---|---|
7uuhdm | Culture | How does a bill that passed overwhelmingly in the House and Senate (98%+) not get enforced by the executive branch? | In response to the title, since the Executive branch has sole authority in enforcing the law, as a consequence it can choose not to enforce the law at all. In response to the post, since I do not know what specific bill you are talking about I can describe the two vetoes. First, the President can outright veto a bill on his/her desk and send it back to Congress within 10 days (or it defaults into a law) to vote on it again. If they get a two-thirds majority it becomes a law without having to go back to the President, if they do not get a two-thirds majority, it does not become a law. Second, a pocket veto is when a President does not sign a bill into law at the end of the 10 day time limit **and** Congress is not in session at the end of the 10 day time limit to override it with a two-thirds vote. | 1 |
hq0zz4 | Chemistry | What happens to smoke once we don't see it anymore? | First, it gets diluted until it's too faint to spot with the naked eye. In the long run, the solid particles (which make it opaque) are trapped in rain or snow and carried back to the ground to be broken down by microbes or just become sediment. The gases also mix with the atmosphere and get chemically broken down depending on their type. CO2 mainly gets taken out of the air by algae and plants, nitrogen oxides and sulfur oxides react with water to form water-soluble acids that also rain down. | 3 |
65t3dt | Technology | If Windows' constant ask to restart your computer after updates has generated into a meme, then why haven't Microsoft changed their approach to try to get the user to implement these updates? | They understand but the other option is to let a lot of computers remain vulnerable. This was the problem that Windows had since the internet was a thing and partly how Windows earned its reputation as being woefully insecure compared to competitors like Linux and Mac. With Windows 10, they decided to take an aggressive approach to get updates down onto as many machines as possible to prevent Windows PCs from being infected en masse like in the past. The problem there is that you just, well, *have* to restart your computer after some updates because Windows can't write to certain files while it's running. This, too, is another security feature to prevent hijacking of system components which was a problem prior to Windows XP (and not really fixed that well then). | 1 |
c83ec9 | Biology | Why did humans develop the cold shock response? Humans automatically hyperventilate when they are exposed to very cold waters. In fact, the "cold shock response" is the leading cause of death for immersion in cold water. Why and how did we develop this as humans? Wouldn't a response like this decrease fitness and be harmful? | Pretty much anything involving physiology of the body involves it trying to reach *homeostasis* , which is an overall balance. In = out, up = down etc. when you fall in cold water, your body only realizes: I am suddenly cold. Really cold. This is my new normal, and I need to balance it out. So it goes into triage mode and recruits your sympathetic nervous system (fight or flight) It constricts vessels and concentrates blood to your core to keep you warm, as well as makes you hyperventilate so that you are getting more oxygen into your lungs so that your skeletal muscles are ready to do some work. The problem is that this is one of the situations where the rapid breathing is bad. CSR usually resides after a min, but because people who have fallen in cold water with the threat of drowning have been in there for a while feeling panicked, they’ll hyperventilate as a psychological response, not one that the body is trying to produce. The problem is, to calm someone down during a panic, you have to actively work towards the parasympathetic ns (opposite of fight or flight, it induces relaxation) which could then kill you. The body can’t be perfect at everything, though it seems like cold water submersion is one of the few situations where the sympathetic NS works against you. | 3 |
a5x6gf | Biology | Why would a butterfly be attracted to a human? I recently watched a video (link below) where a Monarch Butterfly (named Penelope) hung out with this guy for about a week. I would like to understand why a butterfly would do this. URL_0 | Butterflies tend to eat nectar or other sources of salty or sweet liquids. Humans are covered in salty-sweet sweat, sebum, and other skin secretions which are tasty to insects and other animals. Additionally, some humans use soap, body wash, shampoo, or perfumes which may smell floral, further attracting insects. Furthermore - this is a self-reported incident. It's very likely that the person in that Youtube video is exaggerating the butterfly's attraction to him because he wants to think it likes him. | 7 |
hcwgi1 | Technology | How does a game get easier or harder when you switch difficulties? | Most of the time it changes things like how much damage you do to enemies and how much they do to you, and how much health you/the enemies have and how fast (if ever) it regenerates | 1 |
860rwq | Engineering | How are military systems like fighter planes protected from backdooring or other neutralization against their original country of origin? Let's say a country buys fighter planes from USA or Russia and then later on goes to war against the fighter jet's manufacturing county with the said jets. What prevents the original manufacturer hiding code to disable the jet's electronic warfare suite or critical systems via backdoor in their proprietary code or otherwise leaving vulnerable spots to be exploited in such situations? | 1. Complex systems like fighter planes are only sold to allies in the first place. 2. When developed nations buy military hardware of this sort, they generally don't buy the actual hardware but rather the *design* of the hardware - which they then produce themselves. So the only people who would have to worry about the black box nature of the hardware would be the sorts of developing nations that lack the industrial base to produce such equipment anyway. 3. The manufacturing nation doesn't need a 'kill switch' to disable the hardware since the hardware will cease to function in short order without the logistics chain. This happened to Iran after the revolution - their world class air force quickly became scrap metal not from hostile action but simple inaction. The manufacturers stopped supporting their equipment and they ran out of parts. 4. Any such 'kill switch' creates an attack vector that a hostile power could use against the manufacturing nation. The U.S. military would never permit a U.S. manufacturer to include such a device in hardware they were paying for, so it would need to be custom-designed for foreign sale. While not impossible, it would be relatively difficult to hide this sort of mechanism. | 5 |
jd2kd2 | Technology | In glitter paint, how does the paint color not cover up the glitter and just turn it into gritty paint? | Paint is really translucent. In blending, layering, and with thickness (and painted over other colors in base capes and primer) is when it has an opaque quality. When flecks are suspended in the paint it’s close enough to to the surface that it’s visible. In addition it also adds the perception of depth as it suspends at differing levels within the paint. | 1 |
a9wtd5 | Biology | Why do you get so tired after spending a day at the beach (I'm from Australia btw) | All these comments are hilarious but I think I’ve got the answer! Besides the sun exposure, water getting in the ear stimulates the parasympathetic system (rest and digest) as the vagus never (biggest parasympathetic nerve in the body) is located very close to the middle part of the ear. We typically find this whenever we swim and go under water. Sun on the outside of the skin shunts blood to the core because heat isn’t needed on the outside and extremities. This sends blood to vital organs instead, further stimulating the rest and digest system, this would be a visceral-somatic response. I don’t have any references but this is just my functional anatomy/physiology knowledge. Cheers | 11 |
dwfysj | Technology | How come old Gameboys looked great in direct sunlight but modern screens are unusable in bright conditions? | Old gameboy did not use back lighting and they were designed for the light to be provided externally. Modern screens use backlighting and are designed for the light to come internally. As a result excessive external light will cause glare on newer devices. Back lighting is when the light source for the screen is provided from behind the screen. | 2 |
7xgoun | Repost | Why A Glass Of Water Left Overnight Develops Bubbles? | Gases can dissolve into liquids. The amount of gas that can dissolve into a liquid is dependent upon the temperature of the liquid, and the pressure of the gas at the interface (the boundary between the liquid and the gas). In this case, the pressure is the atmospheric pressure in your locality. When you fill a glass with water from the tap, there will be an amount of gases dissolved in it (mainly nitrogen and oxygen, as these are the most abundant in our atmosphere). Typically the temperature of the water from the tap will be considerably lower than the room temperature. As the water temperature increases to the room temperature, the amount of gases that can remain dissolved decreases. Microbubbles of gases will begin to form. They will collect on imperfections in the surface of the glass. (The glass looks and feels smooth to us, but at the microscopic scale it is not.) As they collect on the imperfections they will coalesce (fancy word for them joining together to make bigger bubbles). Eventually they will get big enough to be visible. This effect is similar to bubbles coming out of a fizzy drink, but in the case of a fizzy drink it is a sudden reduction in pressure (taking the cap off the bottle) that causes the dissolved gas (carbon dioxide) to come out of the liquid. | 1 |
9oojpi | Biology | how and why does a human lose consciousness when falling asleep? | We know that there are neuronal pathways that, when destroyed, causes a person to fall into a coma. For simplicity, these are often called the "arousal pathways". Briefly, these include acetylcholine neurons from the dorsal pons and basal forebrain, norepinephrine neurons from the locus coeruleus, serotonin neurons from the raphe nucleus, and histamine neurons from the tuberomamillary nucleus. When these circuits are active, we're awake and alert. The arousal circuits are constantly inhibiting a region of the brain called the ventrolateral preoptic area, an area of your hypothalamus. Your vlPOA is an area of our brain that is more active when we're asleep. Your vlPOA is also in turn constantly inhibiting your arousal system, creating a sort of "flip-flop" tug-of-war between sleep and wake. When you're asleep, these arousal circuits are turned off by the vlPOA, and while you're awake, the vlPOA is turned off by your arousal system. Also, when we're awake for a long time, we see a build up of adenosine in the brain. It turns out that adenosine also plays a key role in turning ON the vlPOA, and thus turning off the arousal circuits. Another bundle of neurons that isn't technically part of the arousal system are orexin neurons in the lateral hypothalamus. These neurons don't technically cause "arousal", but instead they kind of broadly activate the whole arousal system. As it turns out, the activation of the vlPOA also deactivates the LH orexin neurons. These orexin neurons also change their activity based on the time of day, and your hunger/satiety levels. Hunger tends to cause an increase in activity, while satiety causes a decrease. This was a dirty shotgun version of the neural control of arousal. I can elaborate or explain other things in more detail (aka better, I don't really explain anything :P) if you'd like. | 1 |
a4y9zi | Biology | How do animals keep track of their babies? Can they count? If so they know math? If not what kind of logic they use to know how many are there? | Counting isn't required to detect someone is missing, just the ability to distinguish individuals. Suppose you have no concept of numbers or math but you have children Billy, Bobby, Sally, and Sarah. You see Billy, Bobby, and Sarah. Where is Sally? You don't see her, she is missing. See? No numbers, no math, but it gets the job done. | 22 |
dpugx6 | Economics | “: what is the difference between tax avoidance and tax evasion? Other than one is legal and one isn’t. | Tax avoidance is using the legal means within the tax codes to pay less money in taxes. As a simple example, if I took $2,000 and donated it to charity today, I would not have to pay taxes on that $2,000 on next year's taxes. I'm paying less in taxes than I would have if I'd kept that money, or if I'd spent it on a nice shiny TV. There's nothing wrong with this sort of thing in normal circumstances, because the system is set up to encourage stuff like that. Though of course because of the enormity of the tax codes and all of the ways that it's possible to reduce a person or company's tax burden, it's possible for enormous companies with huge incomes to pay very little in taxes - which isn't always what's intended. Tax evasion is finding other, illegal ways to hide money or otherwise evade paying taxes on it. If I took $2,000 for doing a contract job and then didn't report it on my insurance forms at the end of the year, I'm committing tax evasion, because there's no fair reason I shouldn't be paying taxes on that, I'm just cheating and hiding my income. That's actually a crime, and if the IRS finds out, I'll be in trouble. | 1 |
l1qfp1 | Chemistry | I’m trying to find the best way to word this but how does one measure “negative degrees”, like in temperature, like how do you quantify the absence of something that isn't tangible? | Fun fact: the opposite of heat isn't heat but the absence of heat. "Cold" isn't really a thing, it's a construct for helping us compare various temperature points. Temperature is a way of measuring energy. What's being measured isn't an absence of something but instead a reduction on a fixed scale with an arbitrarily defined zero point. The problem is that we need common points of reference. As early scientists developed the ability to consistently measure and quantify temperatures and built thermometers to measure those temperatures reliably and repeatedly, they had to define what we were measuring it and the steps we were measuring it in. The first common scale was the Fahrenheit temperature scale, developed by a Dutch physicist named (shockingly) Fahrenheit. Per the official paperwork, he defines the zero point of his scale as the temperature which a mixture of water and ammonium chloride freezes, which really makes little sense as a zero point until you consider the unofficial reason of zero being the lowest temperature his hometown reached while he built his thermometers and then having to backwards justify a repeatable value. He defined 32 degrees as the temperature at which pure water freezes because why not, and 96 degrees as the temperature of the human body because at this point he was still developing a foundation on which temperatures would be measured in the first place. After a while people realized that Fahrenheit was, well, very arbitrary in the values it set so they developed another scale - Celsius. It set the zero point at the freezing temperature of water with steps of 1 resulting in 100 being the boiling point of water, which is very useful in science but odd for daily use because half of the scale is very inhospitable for human life, but it gained traction due to its scientific adaptation and has been adopted in much of the world. There's also the Kelvin scale, which uses the same degree increments as Celsius but defines the 0 point as the point in which there is no heat energy to measure. In Kelvin there are no negative values because nothing gets colder than 0 Kelvin, and water freezes at 273.15 degrees. Basically, there isn't a singular correct way to measure temperature so various decisions were made to build a consensus on how we as a society would have common scales to measure temperatures, each with its advantages and disadvantages. | 5 |
6kmig1 | Biology | How did Coral, which cannot tolerate a temperature change of 1 degree Celsius, manage to survive Earths changing climatic history? | We are seeing the fastest change in global temperature in our historical records. In the past coral and other species had plenty of time to adapt. | 16 |
byajdy | Chemistry | when popping popcorn, why does the first kernel popped not burn while the others are being popped? | While there are still a lot of unpopped kernels and only a few already popped, the energy is absorbed by the unpopped kernels. It is only until a few unpopped kernels are left, that the already popped kernels start to absorb energy and get burnt. Copy pasted my top answer from: URL_0 | 10 |
akorhw | Other | Do doctors really give their patients x months to live? | There are statistics which say how long patients live after being diagnosed with certain conditions. And the doctor will often tell the patient these numbers. However there is a lot of issues with these statistics and the doctor should explain all this to the patient. For example some diseases is mostly diagnosed in elderly or weak patients so they tend to not live long while the same disease can easily be cured in a healthy patient. The statistic may not account for such things. There is also a lot of variation among people so you have to take the average lifespan with a big grain of salt. Often the doctor will give the statistic as a chance to be alive after certain time frames. For example instead of giving a patient 6 months to live they may say that they have an 84% chance of surviving the next two months, 52% chance of surviving the next 6 months, 37% chance of surviving the next year, etc. | 3 |
kxg2ka | Biology | How does blood circulate through your body after you've had an amputation? | Your circulatory system is not just one singular loop, it branches and splits, then comes back together again later. There are numerous routes blood could take to get to your finger, for example; but they won't have come from your leg. URL_0 Blood takes a fairly straight path from your heart and lungs to your extremities, and back again. | 2 |
a5qivs | Biology | Why does pee get more yellow the more dehydrated you are? | The more hydrated you are, the more diluted the waste is in your urine, making it looks clearer. The less hydrated the more concentrated it is. | 2 |
88u5lp | Mathematics | If we can never find the exact value of PI, why are we still calculating further digits of it? | With only 39 digits of pi we can calculate the diameter of the observable universe down to a error margin of the width of one proton. The big reason for calculating enormous digits of pi is to test supercomputers. | 3 |
jyb8f9 | Economics | Why have housing costs rose so much in the past decades? | In canada we have roughly the same amount of houses scince the 70s and more then double the population. Simple Supply and demand it would seem, but the issue gets more complicated municipal governments, provincial governments, and the federal government have made it exceedingly difficult to build houses. Soooo much more money needs to be spent. I'm a carpenter who builds all kinds of structures and I can tell you right now the amount hoops you need to jump through all need a professional in their own field who will charge a lot. Example from my last job build the house 160k, septic 30k, electric 20k, plumbing and heating 40k, this is around 250k and we haven't gotten to windows, doors, or interior finishes, kichen, bathroom or thermal efficiently testing. But the house after its approved and its appraisal will show a value of 200k total cost almost 500k, in our area you can buy almost 3 for that price adding to the devide with population vs number of houses, so in short the issues are with the authorities allowing a bottleneck and people of all trades taking advantage of it as well as people just don't want to build their own house anymore. You used to be able to just order a house from a store and everything would just show up diy typ thing. Here URL_0 On and added not: inflation has very little to do with house prices comparatively to average salary. Mortgages went from 3-5 in our grandparents age to 10-15 mabie as high as 20 for our parents and young people now days can get up to 30 year Mortgages...... witch is insanely crazy it takes one person 3 months to put up a house themselves, 4k in tools ( if you want the best. about 60k in materials for most 4 bedroom 2 bath attached garage. Everything else is a bit of land, local administration requiring a ticked professional to do their specific service and take out permits then have it inspected. | 5 |
72jgfy | Biology | Has all the nuclear radiation emitted since 1945 affected human genetics at all? I've heard opposing things about nuclear radiation and genetic effects. On one hand, a study found that there was no increase in genetic disorders among the descendants of Hiroshima and Nagasaki survivors, but on the other hand it's well established that some plants and animals mutated after the Chernobyl disaster. I've also heard that the Chernobyl disaster slightly altered the sex ratio in affected areas towards male births. Are human gonads too well-protected for the chromosomes in our gametes to be altered by nuclear radiation? | We're exposed to far more natural radiation than to radiation from nuclear weapons, at least on average. The reason is that there are radioactive substances in the ground, and that there is radiation coming from space. [Here]( URL_0 ) is a useful infrographic that shows pretty well how much radiation we receive from what sources. You can see there that the radiation received even by inhabitants of Fukushima is far lower than what the average person receives on a yearly basis from natural sources (Bottom left of the green box). | 2 |
av4u27 | Biology | What keeps bed bugs in check? Why haven't they taken over the world? Do they have any natural enemies? They seem pretty unstoppable - easy breeders, can live a long time without food, can survive harsh conditions, easy hitch hikers, and they feed on an endless supply of human blood. | Fun fact You can take ivermectin and poison your blood and get rid of bed bugs in a matter of a few weeks Ivermectin is safe for children as young as 4 | 42 |
lvad83 | Other | how do we extract meaning from language? Do we link words to mental images and then form a movie out of them? Eli5 how we extract meaning from language? | One of the truly remarkable things about the human brain is how it handles language. There's an entire section of it dedicated just to language-based communication. It's so big and so powerful that I can write every single word of this comment without having to think about it at all - my brain just sends the instruction of "describe how you work" to the bit of the brain that handles language, and that bit figures out exactly what words are needed in exactly what order and sends them out. It's so skilled at this that I only even consciously know which word I'm typing as my fingers have already begun typing it, and it's so much more skilled at this than my conscious mind that when I read it back for any grammatical errors or unclear wordings, my conscious brain gets really confused thinking about what words should come next - but the moment I start writing again it's all autonomous. That's the sheer power and amazingness of the human brain's ability to process language. It does the same thing in reverse - upon hearing language, your brain knows what's being talked about long before you're consciously aware of it or have formed a mental image in your mind. When you hear the word cat, you automatically know what that means long before you start imagining a cat, and when you hear "my cat died", you know that's a sad thing automatically, without your brain having to go step by step through the process of what a cat dying is like. Your brain basically has a huge store of information about the meaning of words and the uses of grammar that lets it handle language processing for you, just sending your brain progress reports regularly. This information store is also why your ability to understand foreign languages can vary a lot - if you just listen to a language lots with subtitles, but without spending any time learning that X means Y, you will pick up a pretty comprehensive understanding of the language's grammar, but you'll have fuck all understanding of most of the vocabulary. Grammar doesn't need that information store to learn, but vocabulary is all about stocking up those shelves. And eventually you get to a point where you no longer need to consciously translate sentences word for word, because your language centre can go straight to the information store and know what words mean. | 2 |
d3k5va | Economics | Why do coins in currencies exist and how is their maximum value chosen isn't it easier to simply use only paper money? | Coins existed before paper money. Coins go back to people like Croesus two an a half millennia ago. Paper money (at least in its current form) is a lot newer. Paper is usually used for higher values while coins is used for lower ones. Part of this has to do with coins lasting longer than paper money and in theory being easier to forge than modern bank notes. A lot of the reason also come down to tradition. Where exactly the cut is made between coins and paper can differ a lot between currencies. The US having a one dollar banknote actually sets them apart a bit from other major currencies in where they make the cut, many have coins worth more than that. One thing that throws things of is that over the years and decades and centuries the value of the currency changes a lot due to inflation. Back when they were created the first Yen and US Dollar silver coins were worth the same, but they now differ by a factor of 100. Over the years Japan has switched where they make the cut between coins and paper as the value of the yen fell. Nowadays everything less than ¥1000 is issued as coins. Other countries cling to old ways of separating where they switch from metal to paper even it makes no longer sense out of tradition. Having a currency reform is usually a goo point to reset where you switch from paper to metal. | 4 |
7t0pu5 | Chemistry | Why does a candle not create smoke when burning but lots of smoke when you blow it out? Source: blew out a candle today | A flame is ignited fire gases. There are a great many fire gases that can be created in many ways. They all have different "flammable ranges" (temperatures at which it will ignite) and "ideal mixes" (amount of oxygen to most efficiently burn). When something like a candle, fire wood or a room in a house reaches the right temperature it will pyrolyse, first losing whatever water it contains through white steam and then decomposing into black fire gases which, with the right amount of oxygen and heat will ignite. This is why a fire looks like gas rising above whatever is burning, whenever you see black smoke it's because the fire is in efficient and not burning all the fire gases. When you blow a candle out the wick is still hot enough to pyrolyse but the gas isn't hot enough to ignite itself. To demonstrate how this works try blowing out a candle and then holding a match above the wick in the fire gases and watch the flame travel down to the wick. Also Google "tounges of flame" these are ignited fire gases which dance across the ceiling in house fires, way above whatever is creating them. Hope this helps, it truly fascinated me. | 12 |
9zajcw | Other | Why is anxiety and depression much more common today then in years past? | In my opinion, I think we reach a point where we are soooo far from our animal state that we don't have to fight for survive, everything comes easy, we are away from violence,... I think this cause (in big capitalist country) that people have too much time to think, we are understanding how meaningless our life is and we suffer from it. When you travel to poor country you discover that some people lives in really bad condition but they still happier than you only because they don't have time for overthink. They are just focus on working hard and keep their family from trouble. Our society pushing us to "win money", "develop our carrer". This values are individuals values. So from my side, I just want to find a women that loves me and raise kids. I think this will help me to cure my constant negativity mind. Having a purpose haha. | 14 |
6f5ku9 | Biology | Why does background noise seem to calm some people? For example keeping the tv on when not even watching it when trying to sleep. | I do this because I had a very lonely childhood. My parents worked very hard and provided everything for me, they are amazing. However they were gone normally from 7:30am to 8:30-9pm I do have a sibling but he is 7 years older than me and was in rehab when I was growing up. I spent a lot of time alone at home and we had a large and empty home. I was social and had friends but when I was home alone, television is what comforted me. Now, many years later I'm married and have my own home and I will still put on "Family Guy" or "American Dad" because the laughter and jokes comfort me. Its just my thing , it helps me :) | 37 |
8m54vx | Physics | If the Earth is spinning so fast, how do the stars stay so still to us? | Because they are really far away , next time you drive in a car over a flat area look at a tree in the distance looks like it's barely moving look at the phone poles close to you they look like they moving fast , Same if you in an airplane you moving at close to 800kmph but the ground looks like it's moving by slowly Same thing happens with the stars but instead of a couple km away the perspective is amplified by a couple light years away if you setup a camera to do a time lapse you will see that they do move quite a bit over time due to earth's rotation But again to your naked eye it's not noticeable because they just so far away | 2 |
o2hc70 | Earth Science | How did humans first find the gasses on the periodic table we use today, and how did they go about collecting it? Like, did someone just come across helium one day, not knowing what it was, and decided to start collecting it in containers? What about neon, hydrogen, and all the others? How did they know where to look, and even when found, how did they collect it without all the gas escaping into the air around them? | The gases on the period table where discovered gradually. After we started to make the period table logic predicted that if there is an element with 4 electrons there is probably one with 1, 7, 8 and so on. It was just a matter than of discovering a pure form and naming it. Oxygen was unknown for a long time the only hint people had was that- apparently. A rat under a dome died when closed for to long but a rat under a dome with a plant inside lived longer. About collecting it. Most non-royal gases (so everything that isn’t helium, neon, argon, xenon) etc. are in other stuff like water is just Hydrogen and Oxygen. You can do something called an „electrolyzing“ process where you use metal and electricty to split up the water and the oxygen goes to one and Hydrogen to the other pole. That dosn’t only work with water it works with lots of fluid. Royal Gases are a bit tricky. Idk how people did it in the past but nowadays we literally cool down normal breathable air until its liquid. In our air are alot more things than Oxygen. Actually only ~20% of our air is. Its mostly Nitrogen and oh- Royal gases, would you look at that. Anyway you cool it down till its a liquid, however the different gases have different temperatures where they start to become liquids. So by emptying to tank in between you can, over time, split up the different gases. Imagine if you had a sludge of molten metal with- lets just say. Gold and Iron. Golds melting point is way lower than Irons so the Iron will become solid first, you can than take the iron away and only the gold remains. It works the same with the gases just that you have to manually cool it down. | 4 |
bdaaot | Biology | How come our non-dominant hand is less capable than our dominant hand? Why isn’t everyone ambidextrous? | You get more specialized in that certain hand, that's why. Let's play a game: We have two characters Leftie and Ambie Ambie does everything with two hands equally dominant. So she prefers going one right, one left at all times. Leftie only does left hand. Let's give them a task with a reward Task reward: 1 experience points You get a level up at each 5 experience points. Ambie does it 10 times. She gains 5 experience for her left hand, and 5 experience for her right. Her both hands are lvl 2 now. Leftie does the task also 10 times, only with left hand. He gains 10 points for the left hand, while right gets nothing. Left hand is lvl 3 now, while right, he uses it for other purposes. Leftie is better at this task than Ambie now, due to his focused experience. Now imagine if you were an artist, or a surgeon, or any other skill based worker. You can see the advantage. Hope it helped! | 2 |
b24du4 | Technology | how do WhatsApp keep being online? | Facebook owns Whatsapp and uses some of WhatsApp’s data. If you talk to someone on WhatsApp, they are suggested as a Friend on Facebook. | 3 |
6vb9m2 | Biology | How do IV fluids hydrate you when they enter through your veins? I was diagnosed with cancer back in May of 2017, in my chest I have what is called a Central line. The chemo and IV fluids go into a large vein in my chest and go into my bloodstream. While the chemo is attacking all of the rapidly duplicating cells in my body, the fluid is keeping me hydrated but I'm not sure how. I can't drink a lot due to nausea so they load me up on fluids so how does this work? | "Hydrated" is about the water level in your bloodstream, not your stomach and intestines. You need water in your blood to dilute the pollutants, the kidneys filter both out and you eliminate them. In times of high pollution production, as chemo is trashing the cancer cells, you need plenty of liquid to avoid dangerous waste levels. If you can't swallow it, putting it directly where it is needed is an alternative. | 2 |
cik1lz | Biology | How does the nutrition cycle work in the deep sea? With no light, how do the producers produce organic matter? Where do they get the energy from? I’m guessing heat and hydrothermal vents | Hydrothermal vents produce nutrients suitable for bacterial life, which in turn is food for more complex life and so on. A large amount of energy for the deep sea environment comes in the form of organic matter which falls from above. (feces and dead bits, sometimes entire whales). | 2 |
e54op3 | Culture | Why so women have the option of Mrs. and Ms and Miss whereas men have the 1 option of Mr? | The honorifics indicate status to some degree. An adult married (also includes divorced and widowed) woman is Mistress (Mrs.). An unmarried girl and teen are Miss. Ms was developed in the 1900s (mostly) to refer to unmarried adult women. The honorifics for men are Mister (Mr.) for married men, and Master for unmarried men and boys. Over time Mister started to be used for all adult men regardless of marriage status (outside of Bruce Wayne), and then the honorific "Master" stopping being used by most people even for boys. Men's honorifics were just lost and Mr. was used for all males. | 4 |
9sxt0z | Mathematics | why is PEMDAS in that order? | We just need an order that everyone follows. If you solve an equation in a different order you'll get a different answer. If we were to use EDSAMP you'd just see equations written differently and be asking why we don't use something like PEMDAS The exact order of operations isn't important, all that matters is that the person writing the equation and the person solving the equation follow the same order of operations There are many programming languages and even math notations that don't follow PEMDAS but instead work right to left or left to right so you have to convert your equation so you'll get the same answer | 2 |
c1qhk4 | Biology | The brain has to have a limit to how much information it can store. Is this limit ever reached and what happens when it is reached? | Your brain is constantly "cleaning house" especially when you sleep. It discards a lot of unused/unneeded information. I don't think anyone has ever gotten near the limits of the human brain's potential, but I would assume that it would just start overwriting data that hadn't been leveraged for a practical purpose for a while. | 2 |
5ssj7r | Other | Why do people block out license plates in photo posts when plates are seen in the public all the time anyway? | A few reasons. First off, plates are unique. Even if you don't intend to track someone down, you could confirm if a given car is one in your neighborhood based on the plate. This could be a safety concern if used maliciously. Second, while some government records are restricted, other records are not. For example, if you work for an oil change company you might be able to look up customer info by plugging a plate into your system. Third, since there are government databases, you may be concerned about what they see. If a January 2017 local car blog article talks about your custom car with aftermarket exhaust and you just moved to California, you might have reasonable concerns that California DMV could investigate or fine you even if you've brought the vehicle back into compliance with local regulations. Likewise, if a photo of your car appears in a news article about a local store sit down for criminal activity you'll be concerned that it might be investigated, even if you were parking to enter a different business. | 26 |
i93sz9 | Chemistry | Why is the aroma of cannabis so pungent and penetrating? You can smell when someone's smoking weed a mile away, And you can tell if they have it on their person. It seems like cannabis is the whiffiest substance known to humankind What is the chemistry and physics of this? Why does it smell so strong?; How does the smell seem to spread so far? Thank you. | The bud that is used in smoking is a flower of the plant. Flowers are typically the sources of aroma in most plants. The aroma comes from the terpenes, organic aromatic compounds found in the flower of plants. There are over 120 types of terpenes identified in cannabis. They evaporate and spread the scent of the flower. Different strains contain different amounts of terpenes, which is why we differentiate between the strains based on the aroma. | 1 |
9wfefs | Other | How do people get surprised and die in wildfires? | There was an old man on the news Saturday night and all he was able to muster as he stood in front of his burnt house was "I thought I could save it." Reminded me of the people who think they can ride out a hurricane and save their homes from damage somehow. | 23 |
mfh4q4 | Technology | How do power plants actually make electricity? | Something inside the plant creats physical work. This can be burning coal to heat water to spin a turbine, or letting the wind push a fan blade to spin a turbine, or allowing water to fall onto a wheel to spin a turbine... I'm sure you see a pattern here. That turbine is connected to a system of magnets, which are spun around using the turbines. And by placing copper cabling next to the spinning magnets, an electric current begins to run through the cable. | 3 |
l3x0p9 | Technology | when Adobe Flash ‘died’, why did it cause every Flash program to stop running? I don’t really have much of an understanding of computer programming, but I thought that Flash was just another program that was installed on a computer to access content. I read a story about how it caused a Chinese railway to stop running which is just mind boggling, but for simpler things like games and other interactive content, why can’t you still access them? | Adobe specifically included a kill switch in all Flash updates since they decided to finally end it for good, in order to avoid a Windows XP/Internet Explorer 6 kinda situation. The browser maintainers also did this separately, so browser refuse to load the Flash plugin. This is very rare to see for this kind of program and only goes to show how huge a security threat the existence of Flash was. If you *must* run a Flash SWF file, there is an open source player called Lightspark. | 2 |
j2717r | Biology | Why are sweet fruits so inconsistent in quality? | things that grow on trees and bushes are harder to detect faults in over root and other ground foods. basically, you look at a carrot that's all mushy on the inside, you're gonna see it right away. you look at an apple all mushy inside, the only way to tell is to bite into it because the skin is hiding what the "meat" looks like | 2 |
edyifc | Physics | What is the relationship between lumens, watts, energy source, and environment when designing a lighting device? | Lumens are used to evaluate light intensity, watts are the energy used by the bulb/emitter, energy source is where you get the energy, wether it be a battery (dc) or mains (ac), environment is where you put the light emitting device, outdoor lights can be way too powerful for indoor use and indoor light emitters may be susceptible to water ingress amongst other factors. | 1 |
6c7bj5 | Engineering | If traditional locks are easily picked, why do we still use them? What are the great advantages of tradicional locks over other designs? Security doesn't seem that great... | Physical locks are not meant to make things impossible to get to. They just make it hard to get to. No amount of physical locks will ever make something 100% secure because even if they are unpickable, and there are some unpickable locks, physical things can be broken. The point of physical locks are that it takes the robber time and energy to get around them. If it takes more time and energy to do it most robbers will just go to the next location and hope there is less security. because of this most people just need convenient locks. Ones that do not take up a lot of space or time to open. It is only when we see extremely valuable things that the higher tech locks that take a lot of space/time/energy to work with. | 8 |
7lkfru | Biology | How does the body separates water from stomach acid? When we drink water does it just mix in with the stomach acid, or what? | Despite what it sometimes feels like, you don't walk around with large amounts of acid just sloshing around in your stomach. Instead, a special type of cell found in the stomach lining produces acid (H+ ions, i.e. protons), as you need it. Some people have a problem where they produce too much acid and/or produce acid all the time. That's what you use drugs like Nexium - they are called proton pump inhibitors and they do what the name suggests - suppress excess acid production. But yes, the water you drink will mix with any acid present, which is no big deal. When you need more, more will be produced. When whatever it is leaves the stomach and travels to the intestine, your body produces a compound(s) that will neutralise the acid so it won't burn your poop chute. | 5 |
d6nwlb | Biology | Why exactly do we age? Can it be slowed down systemically? | There are three main reasons. First, very few of our cells live more than a few weeks. Most cells in our body are copies of copies of copies. The copying process (mitosis) is extremely accurate, but errors do happen. Over time, these errors are compounded. Imagine making a photocopy of a clear picture, then making a photocopy of the photocopy, etc. After enough cycles, your picture becomes lousy. Second, genes are built with a structure called a telomere that limits the number of times these copies can be made, even assuming the process is error-free. Aging is built into our DNA, so to speak. Third, metabolic processes produce "junk" or "waste" molecules. There are special cells and organelles whose job it is to clean this junk up. But they are not perfect. Over time, the junk accumulates between cells. | 2 |
6m2kym | Biology | Why do we get random pains in our body that stay for short periods of time and come at random? | LOL is this going to end up being one of those threads where OP describes his symptoms and an MD correctly diagnosis some sort of terrible disease? | 2 |
meshwr | Chemistry | how the eff do magic erasers work so much better than soap and water? Don’t understand how they work so much better. | Part of it is the slightly abrasive material! As it breaks down, the grittiness helps removes stains/dirt. I learned this by going in too hard on a wall and removed paint by scrubbing too intensely lol. I am sure the chemicals help break down messes somehow but I don’t know the science or anything. | 3 |
mzvuy5 | Physics | Is possible to do a water wired computer? I asked to my stepdad if, since the water cunduct electricity, is possible to reduce computers costs by making “water-wires” instead of copper ones. He said that isn’t possible, but I’m not understanding why! He said that electricity travel from - pole to + pole. So why with water doesn’t happen the same?!? | This is a bit tangential of an answer, but you could make a computer [with the flow of water instead.]( URL_0 ) | 5 |
mrzpdm | Biology | how can Homo sapiens and Neanderthal be different species but Neanderthal dna is common in modern day people To my 5 year old knowledge I thought Neanderthals were different species but for us to have part of their dna that means they got jiggy together and created fertile off spring with Homo sapiens but when a donkey and a horse do it they make infertile offspring? Are we not like actual separate species? | The way you are taught "what is a species" in school is a gross simplification In nature, organisms do not adhere to strict rules. The high school level 1 biology class definition of a species is sorta accurate for many animals, but there are many many exceptions. There are genuses that produce infertile hybrids, sure, but there's also things like "ring species" where geographically-adjacent species can each interbreed with their neighbor, but *not* the neighbor of their neighbor. And there are species in the process of diverging so there may be different populations that are becoming different sub-species Humans and Neanderthals have a lot of differences, but those differences did not extend to differences in reproduction. | 3 |
eckxy7 | Other | How do PhD's work? I've heard that working on your PhD takes years to do, and that it's essentially a full time job. If it's a full time job that takes years to do, how do people afford to both pay years worth of tuition while paying for basic housing and everyday essentials? | Any full-time PhD worth doing is paid for. At the bottom end, it's tuition + $10,000/year or so. At the upper end, some PhDs are tuition + $40,000/year + healthcare. This may come from teaching duties (common at state universities, especially), fellowships (such as from private foundations or the government), or just from the department's budget. For mine, I got about $30k/yr + healthcare, and I did some teaching for extra money. Didn't take on any debt but it was pretty tight living. On the bright side, PhD salary is taxed less than normal salary (in the US, at least), so it goes a bit further. PhDs contrast with professional doctorates, like JDs, MDs, DOs, etc. which are almost never paid, absent a few scholarship programs. The PhD almost always takes longer, though. As for full-time job, it is almost always intended to be full-time for most students. There are students who work on their PhD part-time, though. They usually get free tuition, but not a salary. A lot of times their PhD work becomes part of their actual job, though. For example, I knew a forest ranger who worked on his PhD over 10+ years as part of his job (ecological observations). Someone else I knew was a govt. official who collected data as part of their job and did analysis over the course of years as part of their PhD (with approval, of course). Another person I knew was in the military and received 3-years of paid leave to get a PhD that the military needed experts in (note: 3 yrs was an absurdly short time lol). There's a ton of variety in this type of degree, basically. | 2 |
nb5mw8 | Biology | Why our body rejects organ transplants from others but not blood (of the same type)? | Most of the answers above are to some extent right, but none is - imho - sufficiently explaining the issue. Obviously, this is a very complicated topic and no ELI5 abswer can cover the whole of it. However, I'll still try to give a brief overview. So every cell in our bodies expresses different surface antigens. The most important one un the context of organ transplantations is the MHC (major histocompatibility complex; "histos" being greek for tissue). MHC are actually found in all vertebrates, I think but I'm not 100% sure. However, they are definitely found in humans, and there they're called HLA (human leucocyte antigen; because they are easily isolated from leucocytes and play a big role in their regulation as well). This MHC is sort of a passport of a cell that indicates it's human. Also, these structures differ from individual to individual, so it's not only a passport telling you it's a human cell but also telling you what country (aka individual body) the cell is from. Now in a living body there's always leucocytes all over the place that constantly check cells' MHCs/passports. If a cell does not have an MHC, it is killed, as there's definitely something wrong with it, e.g. it might be a cancer cell. If a cell has an MHC but it's different from the one of the body the leucocytes are from (e.g. the recipient's body), it will also be killed. To simplify and further stick to the passport analogy, if the police (leucocytes) find a cell without a passport (MHC), the cell is killed, and also if they find a cell with a passport from a different country (MHC, but different from the host body's MHC), the cell is also killed. That's why we try to match organ donors and recipients to have their HLAs (the human version of the MHC, if you remember) match as best as possible in order to prevent immune reactions against the donated organs. Also, this is the reason why we give immunodepressant medication, in order to reduce the host's leucocyte reaction to the donated foreign cells. Basically, it's like giving the police donuts so they get lazy and don't do their job anymore because they're busy pumping their carb intake up with the donuts. The mechanism behind blood transfusion is a little different. The ABO system works in a way that you always have antibodies against all antigens you do not express yourself, regardless of whether you've been transfused blood before. Think of it like a country (body) in which the cops (antibodies/immune system) are fighting mob bosses (A or B antigens/blood types). Generally, the cops would attack all antigens, both A and B. However, if the country (body) collaborates with the A type mob bosses (i.e. the person is blood type A), the cops know the A type mob bosses and don't attack them anymore. Thus, such an individual can safely be transfused with type A blood cells. However, if the cops come across a B type mob boss (i.e. blood transfusion of type B blood), they will fight the B mob boss and kill him (aka hemolysis, which has all kinds of bad implications come along with it). Similarly, in a person with blood type O, there's no mob bosses the country is collaborating with, so the cops will fight any mob boss they find. Thus, people of blood type 0 can only receive blood transfusions that aren't mob bosses (i.e. transfusion of type 0 blood, erythrocytes of which express neither A nor B antigens). People with blood type AB have, to stay in the analogy, collaborations with both A and B mob bosses, so they can receive both type A and type B blood as they know both antigens/mob bosses and thus won't fight them. As for why the HLA reaction does not occur with blood transfusion, it seems there's a relatively small amount of HLA molecules on the surface of erythrocytes (red blood cells) thus mitigating the effect. However, there are reports of reactions happening. For further reading, if you're interested: [Article on clinical relevance of HLA in blood transfusion]( URL_1 ) [Some general information on HLA in the context of blood transfusion]( URL_0 ) Sorry for having written a whole novel in this comment; I wanted to take the time to explain it somewhat exactly, as the question touches two quite complex topics. If anything is unclear or there are further questions still to be answered, ask away! Edit: Found another review specifically on the topic of HLA sensitisation in blood transfusions: URL_2 | 3 |
ko888w | Biology | why you risk pregnancy 3-4 months after a vasectomy and your tube has been cut Have a vasectomy scheduled in 2 weeks, and doctor mentioned that I can still get my wife pregnant 3-4 months after the surgery. How is this possible? | I know a family that the youngest was born 10 months after Dad's surgery. Take it seriously! | 3 |
haaw7h | Biology | Would the Fungi that turns ants/other insects into zombies be nearly impossible for Humanity to worry about due to how complex our minds are, contrary to the insects? | We can't really be sure. Complexity of our minds isn't guaranteed to be relevant to resisting such a parasite though. Our basic needs and desires are controlled by a part of our brain which is relatively simple. The ability of a squirrel to feel thirst doesn't seem to be notably different than our ability to feel thirsty for example. A parasite that manipulates our basic desires may be unaffected by the complexity of other parts of our brains because the parts that control basic desires are still very simple. Then all that is left is keeping the more complex parts of the brain from interfering with satisfying that basic urge. If you make someone feel thirst but drinking would expose them to critical danger then they can resist drinking. Shutting down higher order functions is pretty simple though; a high enough fever can induce delirium regardless of brain complexity. At that point the victim is too stupid to avoid following the basic compulsion. | 3 |
eurcsm | Biology | How does alcohol kill neurons? | It doesn't. This is a common misconception. Unless one gets to a point where there is so much alcohol in their body that they aren't breathing enough, alcohol won't damage neurons. It will temporarily affect the brain, and it certainly can do damage to other organs (mostly the liver and kidneys) | 1 |
dx1qxv | Biology | I’ve been prescribed meds that have a warning that they might trigger suicidal thoughts. How would a medication do that? | Not to pry, but is it an anti-depressant? One thing that happens when depressed people start to take it is, it takes a while to ramp up to full strength. Then when it starts building up, but isn’t quite full strength yet, people finally feel just well enough to give them motivation to go do it, when they couldn’t summon the will to do it before. | 1 |
npqcbe | Technology | how does a computer ‘read’ a disk? What exactly is on the shiny side of the disk that is able to be read and over-written by the computer and it’s laser and then play a video game? | So Hard Drives, floppies, and most tapes are read magneticly. Think the disk cut like a pizza and then ringed. Each section is magnetically charged. It can be read as a 1 or 0. Lost of 1s and 0s can be converted to data. Disks like CDs and DVDs are a bit different. Think of a spiral groove like on a record. In the spiral there's pits and lands. Basically it looks like Morse code - - - . . - it is also read as 1s and 0s. | 1 |
5n9lbp | Engineering | How are big items loaded in to a submarine. I was wondering how does a submarine get loaded. Say if a fridge needs to be replaced how do they get it in and out. Does it just go in to the top hatch or is it be loaded a different way. | The normal accesses to the boat are removable, making a much larger hole for loading items in or out. Anything larger than those openings require cutting and welding the hull. | 4 |
l9wjv3 | Biology | Why is silence necessary for sleep? | Silence is not necessary for sleep. You may be used to sleeping with silence, so it works best for you. But if someone forced you to start sleeping with a TV on, for example, you would get used to it. What really matters are *unexpected* sounds. Our brain filters all of our senses and stops paying attention to things that it gets used to. This is why you never see your own nose...until you look at it on purpose. You can *always* see your nose, but your brain ignores it because it would be annoying otherwise. And speaking of noses, we also go nose-blind to smells after a few minutes. I'm sure you have experienced that. You walk into a place and smell something, but later you don't. The smell didn't go away, you just stopped noticing it. Your ears are the same. Noise that you have become used to just fades into the background. People often sleep with a TV or music playing on purpose because the distraction helps them drift off in peace. Some people live near outdoor noises like a busy road or train tracks, and they just get used to it. Your ears and brain are never really turned off. Unexpected sounds will wake you up because your brain isn't sure if it's a sabre tooth tiger creeping into your cave to eat you. | 4 |
ioye0s | Physics | How did the scientists know when was the big bang? | One of the interesting things about light is that it is not instantaneous, it has a measurable speed, and that speed is relatively constant. Since light takes time to reach us it means that whenever we look at a star we are looking into the past. That's why we measure distances in Light Years, that's the distance light travels in 1 year. So if we look at a star that's 10,000 light years away, we are looking 10,000 years into the past. Since we know the speed of light, and we can measure the distance of stellar objects, we can look up and find the furthest objects away from us. Those objects are called the stellar horizon, the furthest that we can see. The universe continues beyond that, but light from that part of the Universe hasn't had time to reach us yet. That's how we know how old the universe is. Beyond the stellar horizon is the CMB, the cosmic background radiation. The leftover shockwave from the big bang. this represents the moment when the universe first became transparent, when light could first travel freely. The other part of the equation is the very early universe. In the earliest day matter was so close together and hot that the universe was opaque. Light couldn't travel, so this early universe was dark and we can't see it. So this part of the age of the universe is a theoretical model. Physicists have created mathematical models to show how the early universe worked and how old it was. Add those two numbers together and you get roughly 13.5 billion years. | 3 |
k6fm66 | Physics | Couldn’t you theoretically charge an electric vehicle by driving through magnetic fields? As far as my understanding goes it’s possible to create power with a magnet moving around a wire coil. Couldn’t we use this effects and charge electrical vehicles by driving over magnets (most basic idea)? | There are talks of wireless charging systems for EVs. Which this idea is very similar to, so yes. But if you are thinking this means an electric vehicle could drive forever, no. You don't just create energy out of nowhere. What you do is turn kinetic energy (motion) into electrical energy. Like in generators you actually have to use energy to push against the magnetic field and produce electricity. In this case, the car now has to push against the magnets. This means that at best the amount of energy the car would get will be exactly equal to the amount of energy it spent moving over the magnets. The laws of physics mean you can never ever do anything more than break even. And in reality, you will have a ton of losses. | 1 |
ertczx | Physics | If the notion that electrons orbit around a nucleus is a misconception, what type of motion do electrons have? Do they just float in one position? Basically, I’m having trouble understanding electrons’ relations to the nuclei they’re attracted to. | My teacher always described it as a ‘dance’. It’s random and unpredictable but there is a pattern and there is consistency to it. They sort of bounce around but based on the amount of electrons it will eventually turn into a relatively orderly pattern. | 13 |
68k80o | Repost | How do music makers know if a melody has been taken or not? If say a song you thought up just happens to have the same melody as another song you've never heard of that's already been published and copyrighted how would you know before you make a mistake of using that song? | Well they generally don't. But we used to play a game where we would write a riff. Then we would play it to the app Shazam and see what it would come up with, in an effort to create a unique riff. | 48 |
791d1d | Biology | How does anaesthesia work in making us quell pain? Does the body stop recognising pain? | Anaesthesia is a combination of analgesia (controlling pain either with blocking nerves using local anaesthetic or central action using pain killers like opiates), hypnosis (making sure the brain doesn’t remember - usually by inducing sleep) and paralysis (so surgery is possible). The combination of these things can be tailored to the specific situation. If you are having a simple surface operation (such as wound suturing) then it can be done with mostly analgesia like local anaesthetic. If you are having a more involved procedure such as an appendicectomy then you need all three components. If you induce hypnosis and paralysis the body still react to pain (increased heart rate, blood pressure etc but you don’t remember it nor move to it). It can be quite important to carefully monitor these these things if the patient is paralysed to prevent awareness ( imagine paralysis alone without hypnosis or analgesia). Some procedures like gastroscope (camera into the stomach etc) can be performed with a hypnotic agent alone that doesn’t induce sleep but does prevent memory formation so you don’t remember the unpleasant bits (such as benzodiazepines). TLDR: anaesthesia is uses one or more of hypnosis, analgesia and paralysis which is appropriate to the procedure being performed. | 4 |
ejjh08 | Biology | Why do sore throats hurt? | Inflammation (swelling) and irritation of the sensitive tissues. That's essentially it lol. | 1 |
a03q2y | Biology | What happens in the brain during a panic attack? | Our brain is essentially flipping into survival mode. Our fear center becomes active which tells the survival center of our brain that we need to react - typically fight, flight, or freeze. If that signal isn’t turned off or the brain doesn’t recognize that the danger is gone, then we experience prolonged symptoms which are the panic attack itself. It often looks like hyperventilation, sweating, crying, racing heart, and anxiety-riddled thoughts. Our thought processes change because in survival mode, the blood in the brain leaves the prefrontal cortex (the area that helps us think logically and rationally) and floods to the survival centers of the brain near the back of the head (which are located in the old brain). | 30 |
9iosur | Biology | Why aren't there any common multi-headed animal? Wouldn't having multiple heads add survivability? | It’s also because traits can only arise out of DNA that already exists and mutations of that DNA. Life on earth (generally) evolved with only one head, and at this point it would take some crazy and practically impossible number of mutations to change that. Additionally, these mutations, even if they did happen, would almost certainly interfere with some other function of the body, likely causing no reproductive success (kids of any kind) and thus, the genes would die with this horribly mutated animal. | 15 |
6l82hr | Culture | How can Scotland Yard function without guns, while police in the U.S. rely solely guns? | U.S. guy here. I don't think U.S. police rely "solely" on guns. In the few interactions I have had with U.S. police they didn't shoot me or anybody else. | 12 |
kfisyj | Physics | How do electromagnets pull paperclips? Title says it all. If I wrap a wire around a nail with an electrical current running, how does it manage to attract paperclips? Does this have anything to do with the Lorentz force? | If you wrap a wire in a cylindrical form, and put a current through it, you effectively created a magnet. This magnet attracts the paperclips as they're made from iron. And yes, you can say this is due to Lorentz force as a magnetic field is created by this electro magnet. | 2 |
h09ilc | Other | Why are news channels in the U.S reporting the news like they're talk show hosts or something? | I prefer to read the news instead of watch it. And even that can be a task cause you have to check and double check sources to verify that statistics and “facts” aren’t coming from shady origins. Many people just look at the headline and go with it but I don’t. | 5 |
8povos | Biology | Why do babies/toddlers scream and cry for a long time when they are tired instead of just going the eff to sleep? | Not sure if this has been mentioned yet but another reason babies and young children cry before going to sleep is because that is how they decompress. They don’t have solid language skills and aren’t emotionally developed enough to sit there and tell you “So I was really over stimulated today by all the fun things we did. I think I’ll take a nice long walk and listen to some music or a nice warm shower to just chill out. “ So they scream to release stress. Also when they’re over tired forget about it- something happens and they get delirious and turn into banshees. Many haven’t learned coping skills or the ability to self soothe which is a very important skill for them to obtain. Thus screaming commences. Parents often refer to the “witching hour” which is often about dinner time for adults. It’s a very real thing. Kids are exhausted and have pent up stress, parents are hungry and tired themselves so they aren’t full of patience and it’s a perfect storm. | 30 |
7lei5u | Other | Why are comedy/sitcom shows often written by a team of writers, where novels and screenplays credit one or few writers. | A screenplay is 120 minutes of content, tops. With usually months or years to get it all nailed down. A sitcom is 20-40 minutes a week, every week the show is on. That's an impossible amount of content for one person to write. | 2 |
f36o64 | Biology | How can a broken heart hurt so much psychically? | It's a great question. I was so hung up on this one girl that after she left, I was in torment mode for at least six months. I physically felt torn up, lethargic, and exhausted. Cold sweats at night. Eventually you grow out of it but damned if the physical toll isn't hardcore. | 5 |
6tp7fa | Technology | How does a Transistor work and why is it so important? According to a recent ask reddit thread, most people don't know what a Transistor is, and apparently the transistor is the building block of modern tech. Help! | Lets talk about a transistor as an "amplifier" device... A transistor has 3 parts: base, emitter and collector. The magic happens between the collector and the emitter and everything is controlled by the base. When you have a transistor acting as an "amplifier" you have basically the collector connected to the power supply, the emitter connected as the output and the base as the input. To allow this to work, you have to polarize the transistor, that is basically provide 0.7 volts of difference between the base and the emitter. This will put the transistor in a state that any increment in the base voltage will make the collector to let pass the power supply voltage to the emitter. It is like having a huge water box connected to a pipe and at the end of that pipe you have a huge hammer. On your hand you have a button. Every time you press that button, the water box dumps a huge flow of water thru the pipe and the hammer hits something with a huge force. Now imagine this: you tap the button 5 times in sequence. Five huge flows of water comes from the huge pipe and makes the huge hammer hit something violently five times. Then someone say: look, you have built an amplifier. Your light taps on that button provokes huge forces on the hammer. So you get your amplifier. That is exactly like transistors work as an amplifier. A small sound reaches the transistor base and that makes the transistor open the doors and let pass the power supply voltage to the emitter that will eventually reach the speakers. So, a small voltage is "amplified" to a huge "voltage" that reaches the speaker and you hear as sound. A variation of this principle is used on computers to act as switches creating what we call "Zeros and Ones". Billions of transistors are combined to create a computer. This is why you need a powerful power supply to have a power amplifier. Always check how much the power consumers. If it says it consumes 120 W but the company claims it delivers 2000W, something is wrong with that numbers. The amplifier cannot deliver more power that it is consuming. It would be a generator of energy... what is impossible. An amplifier will always produce less output in Watts than it consumes because part is lost in heat. | 16 |
kcdqgt | Biology | Why is ‘the talk’ referred to as ‘the birds and the bees’? The flowers and the bees would be a better analogy imo. | There was a reference to the “birds and the bees” in a 17th century manual about life manners back in the 1600’s (I think). That was how they mentioned it and it stuck. I think it was meant to just be a colloquialism on how all animals do it, and not an actual example of things doing it. | 2 |
lcm091 | Technology | what big data is and how it is useful I'm reading a lot on this topic and I cannot understand it | Big data is basically what it says: loads and loads and loads of data. In very simple terms, it is the process of collecting, storing, and analysing vast vast amounts of data for a particular purpose. For example, if you had a way of tracking every single fish in the sea, you would be able to learn huge amounts about sea currents, migratory patterns, fishing impact, etc. It has become a buzzword recently because advances in storage space means we can store far more data than before, advances in computer science mean we can design much better algorithms for analysing data, advances in computer hardware mean we can have much more powerful computers to run those advanced algorithms, and advances in other technology mean it is much easier to collect data. It has also gained a lot of focus in the public eye, as it is often linked with the collection of people's personal data by big tech companies and/or governments. For example, Facebook collects huge huge amounts of data on the behaviours on individuals online, collected from all sorts of sources such as Facebook itself, your browsing habits, your shopping history, etc etc. It uses this data to learn all sorts about you (and others), and can e.g. sell your profile to advertising companies or others. Facebook and others can also look at the data in bigger chunks, to learn all sorts of insights about how larger populations behave and act. You will also find it linked up with other buzzwords such as "AI" or "machine learning". This is because those technologies (or linked technologies that are mis-labelled as them) often underpin the newest and most advanced algorithms used to analysing data. | 2 |
908pcg | Technology | How can video games produce sounds from specific areas in the game? I.e. when you're playing Call of Duty and you hear gunshots how is it possible for the game to emit the noise in a way where you can figure out where it came from instead of just hearing gunshots? | There are two main ways to produce directional sound and positional audio. The theory for each is more or less the same in both stereo speaker configurations and surround sound configurations. The first method is called *amplitude positioning* and is by far the simpler and less computationally intensive of the two. In amplitude positioning, a single sequence of audio samples, such as a voice or gunshot, is played back in each of the speakers at different volumes. Amplitude positioning on a stereo speaker configuration allows for reasonable positioning across one dimension (left/right). positioning across a surround sound setup allows for positioning across two dimensions. The second method is called *head related transfer function*, or HRTF, and is much more computationally complex. HRTFs adjust the pitch, delay, and amplitude (volume) of sounds in order to position them in 3D space. Although surround sound speaker configurations still provide the best positioning, HRTFs can provide excellent and highly accurate positioning on stereo speakers as well. Many "virtual 7.1" headsets are in fact stereo headphones with a digital signal processor that uses a set of HRTFs to convert a 7.1 audio signal into a 2.0 audio signal. Running HRTFs in real time is computationally complex and thus demanding of CPU resources, so many sound cards provide hardware acceleration for doing so. Reverberation and other sound processing techniques are often supported in hardware as well. | 2 |
avjlxa | Engineering | Why can't rockets start like airplanes? | Because it requires a ton of force to reach an orbit altitude (or to escape Earth's atmosphere). The rocket starts at a 90 degree angle but then tilts and angles as it climbs, it doesn't fly straight up. This trajectory uses less fuel than a horizontal launch would, and also helps ensure a smooth trajectory (flight path). Also, conventional airplane engines don't work at higher altitudes where space stations operate because there isn't enough oxygen for the engines to function. | 3 |
cii7gs | Biology | I just learned that having 6 fingers is the dominant trait and having 5 fingers is recessive. If that’s so, why don’t more humans have 6 fingers rather than 5? | My grandpa, my uncle, my cousin and my cousins son were all born with 6 fingers (talk about dominant gene) but the doctors all recommended having the sixth finger taken off (they all had an extra thumb on the side of their thumb) and so they all live with five now. | 15 |
6e3j0g | Technology | How do my Google searches on one device show up as Facebook ads on another device if neither device are connected in any way? Here is the scenario: I have a work laptop and my Android phone. I search for a very obscure and specific thing on my work laptop and it shows up as ads on my Facebook app. Here's the kicker: There is no connection between the devices i.e. I dont use any personal emails or social accounts on my work laptop so there is no profile on there to connect me to my phone, nor do I connect my phone to my work network. How did they curate ads to something I searched on my worklap to my phone almost immediately? Keep in mind the ads are extremely specific and in no way is this a coincidence. | If this happens repeatedly, I'd say at some point you logged into your work computer from one of your personal accounts and now have a cookie planted on the laptop. If the phone / computer are connected to the same WiFi, this would also explain it. However, if this just happened once or rarely, it could be attributed to one of Facebook's ad options, which is location based advertising or "radius targeting". Basically this is Facebook showing ads based on what people are searching for at your location, or within a specified radius of a certain point. Honestly with the abilities Google and Facebook have in this day and age to track people, it wouldn't surprise me if they can take your laptops IP address and your phones GPS coordinates (which they know are at the same location during work hours - half the battle won already), combine that with whatever other secret algorithms and such they use, maybe make connections between search history / behavior on phone / computer, and it wouldn't surprise me at all if they can determine with relatively good accuracy that they're both your devices. PS - That's not paranoia, that's just reality :) | 9 |
cifxe9 | Other | What is a trade school? I hear trade school does not cost a bomb unlike normal universities. I am not American. | Trade schools are schools that train you for work like welding, plumbing, etc. They are generally cheaper and faster and you can often make comparable starting wages as compared to entry-level engineering jobs. | 3 |
g3mvs1 | Biology | Is there any explanation why when we sleep it seems like time is so fast? For example, ive been asleep for 9 hours but it feels like just a minute. | It all has to do with attention. Since this is a limited resources that we use with our conscious mind, there isn't a conscious you to invest resources into the passage of time. When you are distracted with something like a hobby, work, or even just watching TV, you generally aren't devoting attention resources to the passage of time. But when it's 10 minutes before clocking out to leave work for the weekend all of your mental resources are focused on the passage of time and it can feel like forever. | 11 |
gr79kg | Technology | How do zip files work? | What you've described is known as Lossless compression where, as other have stated, your computer will find similar pieces of information and group them: AAABBBCCC becomes 3A3B3C When you unzip them, your computer can then take this compressed file and rebuild it back to the long form - no data lost. The other type of compression is Lossy compression: Similarly to Lossless compression, your computer will find similar files, but instead of grouping them, it will delete them (how much gets deleted depends on how much you compress) AAABBBCCC could become ABC By using lossy compression you can save even more space and can transfer files faster, but the catch is, the files that are deleted are permanently gone. They cannot be rebuilt, so your file can sometimes be noticeably worse in quality. What determines this is? The file type. JPEG files are lossy while PNG are lossless. MP3 are lossy while WAV are lossless (to name a few). It's important to know this beforehand. So you can either have a lot of saved space at the cost of permanent data loss (lossy) or you can save a little less space, but have no data lost (lossless) | 4 |
73gdvt | Culture | Why does it seem that in some places people don't really have a culture of "hanging out"? I watched a documentary where immigrants commented on the differences between life in Vancouver and urban China. One person said something along the lines of "Vancouver is so much more relaxed because people like to hang out in nature. But in Shanghai, adults meet to discuss business. If you hang out people will think you are a loser." Is it true that in some places, people don't have a culture of hanging out? or if it exists it is seen as something negative? | In China, for example, people work hard crazily to be successful and the competition rate is crazily high due to the population size (at least it is one big factor). Students have also to study until 5 "pm" or later everyday when the National Test (or something like that) which must be taken to be accepted into university with high enough score is coming. Please note, like adults, there are a big number of students in China. They have to stay overnight at school sometimes too, not to waste time travelling to school. While the West stress on balancing between work life and personal life, some/many Chinese tend to stress on doing anything and sacrifice your life to be rich or a millionaire. And when you are a millionaire, you can rest all the time you want. But in reality so many Chinese millionaires are also concerned about their businesses because they built theirs with "overloaded pains" and can't get them fucked-up. So that might by why you saw them discussing business. Like, they can never rest all their lifetime. | 2 |
dxf414 | Biology | If bees dont use all the honey they produce, then why do they continue to make so much more than they need? | Bees don't actually eat much honey. They usually eat nectar or something they make called "bee bread" (and some royal jelly for the baby bees). They will eat honey if they need the food of course, but it is not their primary source of food. Honey is mostly for swarming. When honey bees are doing well enough, the queen lays eggs, one of which will become the new queen and inherit the hive. Except for a few bees left to care for the new queen, all of the other bees leave to set up a new hive at a pre-scouted location. This is called swarming. Honey then, is the high calorie travel food of bees. Its like bee trail mix. It basically never spoils, so they save it up for when they swarm. | 9 |
g4vua3 | Physics | If seasons are due to the tilt of the earth and not the orbit around the sun, how do they occur on roughly the same days every year? | We've specifically designed the calendar so that the seasons don't drift. This actually was a problem in early calendars - people tried to divide the year up into lunar cycles (month comes from moon-th) but this leaves you nearly a week off of the solar cycle at the end and the error rapidly builds. The Romans first tried a 365-day calendar that corrected this, but even that isn't quite perfect. Under Caesar they developed the 365.25 day "Julian" calendar that corrects the drift better, and this was further refined in the middle ages into the current 365.2425 day calendar. It takes 365.2425 days to compete an orbit around the sun and reset the seasons, and the modern "Gregorian" leap year system corrects for those dangling fractions of days. | 3 |
83e3nq | Physics | why is there a universal limit for speed, c, when there aren't any resistive forces in space? Surely if there is no resistive force then constant acceleration can last forever. This would mean that an object could never stop speeding up, hence breaking the speed of light? | When people say in sci-fi movies that "time is the fourth dimension", it's not just a metaphor or analogy. It's quite literal. Time is intimately tied to the geometry of our universe. This means that moving through space affects how you move through time. At everyday scales, we don't notice the difference, but when you start going very very fast, time also begins to bend. You cannot go faster than c, because the closer you get to c, the slower time runs for you. To use a geometry analogy, you can fold a paper in half, until the two halves touch each other. Can you fold the paper *past* that? Well, of course not. You've already folded it as far as it will go. The same applies to space-time. Time is part of the *geometry* of our universe, so it bends along with space, meaning that trying to go faster than c is like trying to fold a piece of paper past 180 degrees. | 11 |
lft6h4 | Economics | Why are patents just "pending" all the time? Why is it that we always see "patent pending"? I know it means a patent has been apolied for, but why does it take so long for patents to be processed that companies actually start manufacturing their products with "patent pending" written on it? Seriously, are any patents ever not pending? | Often a company wants to bring their product to market before the long (25 month) patent process is complete. This doesn't mean that they aren't protected by their future patent, however. Since they still don't officially have the patent, they can't reference that patent number. Instead, they let any potential copy-cats know of legal protection by marking it as "Patent-Pending" & #x200B; Furthermore, once the product is ready to be patented, it is often almost ready to go to market. Waiting the extra time could mean not being the first to market for a new type of product, or becoming obsolete just waiting for the patent. No matter how you look at it, it's not worth waiting for the patent to be complete | 1 |
chpnak | Technology | Images contain location data - how does this work? Is this applicable to all image files, including things like screenshots? | The file containing the image doesn't just contain the picture data (colors of each pixel), but can also contain metadata such as location, camera orientation (e. g. portrait vs landscape) and time where the image was taken. It's simply stored in the file, next to the actual image data. Most phones will at least timestamp pictures, and I think geo-tagging them can be turned off. There is software which lets you see what metadata is stored in your images, like the online tool exifinfo. EDIT: and to answer your question, yes, you can totally manipulate it. | 2 |
76jxsv | Economics | How does Humble Bundle make money when they have discounts that cost them hundreds of dollars each sale, and only make a percentage of the discounted sale? | Sometimes companies will take a loss to get their product out, hoping those who use the product tell others... It’s likely the developers of the game are taking the loss, not Humble Bundle, HB is just a means to distribute the product. Why did companies use GroupOn when they’d often lose money on the deal? Get people in the door to buy other products (eg DLC) or to keep coming back because of established brand (eg buy future games full price) or tell friends to go because it’s great (eg tell friends to buy game after the sale has expired). | 4 |
7pisr5 | Culture | Why is it scary when kids sing or laugh or say nursery rhymes in horror movies/games? | Honestly, kids are just fukin creepy. And when they are used for actual creepy purposes, they turn up to 11 | 7 |
9d51jl | Physics | If the partial moon is caused by the earth's shadow, how can a partial moon and the sun be in the sky at the same time? | It’s caused by the sun shining on only a part of the moon and the rest of the moon is in its own shadow. | 4 |
nk6b5h | Mathematics | Why are degrees measured in the way they are, ie: 90 is a right angle and 360 is a revolution, as opposed to a more simple/rounded number like 500 or 1000? Is there a reason behind it or is it arbitrary? | It comes from the ancient Babylonian number system. Their number system was based on the number 60 which is a very practical number if you want to split things evenly. They divided the circle into 6 equal sections and then these sections were further divided into 60 degrees. We further divide degrees into 60 arcminutes and each arcminute into 60 arcseconds. We just have not found a good advantage to changing this. Although there have been attempts. The most famous was the attempt at introducing grads. There are 400 grads in a circle. Mathematicians however prefer to use radiens. There are 2 pi radiens in a circle which makes a lot of mathematical equations much simpler then when working with degrees. | 5 |
5xmmkg | Other | Why does Milka-Orea commercial calls it "European candy" instead of Milka chocolate, even though it says Milka right in the packaging? | Probably because it doesn't use the legal amount of chocolate or milk to be called a chocolate bar. | 2 |
mt2yn6 | Technology | Why does rubbing alcohol not damage electronics but water does? | You can wash electronics with soap and water without damaging them, so long as there is no current running in the device. Capacitors that still have a charge can cause shorts, so this is also a potential hazard when cleaning electronics. Alcohol is used because it evaporates faster and it's a better solvent. | 6 |
ac5uav | Biology | What are the most common types of anxiety | I'm not an expert, but to my knowledge, social anxiety, which can be limited to certain situations or extremely broad, generalized anxiety, PTSD, OCD and panic syndrome. I've been living with social anxiety myself for 4~6 years and known people who had GAD and panic syndrome. I can tell you they're all horrible. | 1 |
gdpnhr | Technology | How does storage on phones and computers actually work, and why is there a limit? | Modern phones and computers use "Solid State" storage. It works basically by charging super tiny parts (called floating gate transistors) in the solid state drive. These parts hold a charge, and the drive scans to see if the parts are charged (0) or not charged (1). This is binary storage, since all computers run on binary, which is just a very fast input of 1s and 0s. You run out of storage because these transistors, small as they may be, still take up physical space. You can cram terabytes into a very small space, but this is incredibly expensive and most people don't use enough storage to make this worth it. Some computers still use a "hard drive", which is a series of disks with small magnetic particles in them. When writing to a hard drive, a magnet sends specially timed charges to the disk, which then change the magnetic orientation of the particles, and when reading, it detects which ones are magnetized one way (1) or another way (0). Again, it's binary. A hard drive requires spinning discs so it takes a while. SSDs do not require anything moving so they are much faster. So the even more boiled down answer: A small piece of physical space is either electrically or magnetically designated 1 or 0, which the computer can read and turn into an image on your screen. You run out of space because these small pieces are expensive to make and take up room. | 2 |
acgefp | Economics | How does currency exchange work? Like roughly BDT 80tk is 1 USD and BDT 120tk is 1 Pound. What determines this value? | In the end, the value of a currency is determined by supply and demand. Lets assume that, for example, a company produces in the EU and exports them to the USA, where they are sold. The buyers in the USA pay with dollars, but the workers in the EU get paid in euros. Which means that the company has to buy euros with dollars, or else they would eventually run out of euros. So, if there are overall more goods shipped from the EU to the USA than from the USA to the EU, this also means that there are more people who want to buy euros with dollars than the other way round. Which means the euro-havers can get better deals, meaning that the value of the euro rises. This, in turn, means that the european company now makes less money than before (since the dollars they get from the customers are now worth less), and the EU will therefore export less goods to the USA. This means that, at some point, there will no longer be more people who want to exchange dollars for euros than the other way, and the exchange rate stabilises at this point. & #x200B; Then there is also a layer of speculants on top of that, but that is another story. | 2 |