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d2zfgp | Physics | How does Newton's Third Law Apply when, say, pushing a ball through space? Wouldn't an equal and opposite be exerted on your hand, thus canceling out the force and having no net change on the ball? Noticeably different from a rocket, where propelled material is the force that drives the rocket forward. I used to remember the answer to this question, but my physics is kinda fuzzy. | If you push a ball in space, the ball pushes back and you/the ball fly apart. The ball pushing you is why you fly away. You pushing the ball is why the ball flies away. | 3 |
8b35di | Physics | How does colliding particles in the Large Hadron Collider achieve anything? I know that the LHC is basically a giant and long tube where tiny particles are pushed so fast that they travel to the speed of light (not sure how that works or what particles they are using but I disgress) and they constantly mention about colliding these particles together. | Imagine you have a rock. You know that "a rock" isn't a permanent single thing. It has different parts and ingredients. How do you determine what those ingredients are and ultimately isolate them? You start by smashing rocks together until they break. That's what our ancient ancestors did, and their understanding of different rocks and their properties grew as a result. Now, imagine a subatomic particle. We know that "a proton" isn't a single permanent thing. It has quarks and stuff. How do we figure out what those are and what they do? We start by smashing subatomic particles together. That's what scientists are doing now, and our understanding of the fabric of the universe and its properties is growing as a result. Just as our ancestors eventually went from smashing rocks to forging metals and mixing concrete, we hope to eventually grow from smashing protons to forging matter and mixing space. | 2 |
aeost3 | Biology | Why do people stop crying in response to pain as they grow older? | It's a learned behavior. When we cry as children, people help. When we cry as adults, it doesn't work as well and we realize we need to either treat our own injury or find someone that can. | 1 |
ipzr7i | Physics | Why does it take more Delta-V to shoot somebody into the Sun? I saw a meme that stated that, if you're mad at someone, it take less Delta-V to launch them out of the solar system than in does to fire them into the Sun. Why is that? Wouldn't the attraction of the Sun's mass be greater and provide assistance? | Imagine you're a superhero on the roof of a speeding truck, it's going 100 km/h. You need to jump off the truck to the ground, and in order to not hurt yourself and scrape your knee, you need to be falling *straight downwards* when you land. You can't have any horizontal momentum. This means you're gonna have to be able to launch yourself backwards off the back of the truck at 100km/h, so that your launch speed counteracts the speed of the truck and your resultant ground speed is 0km/h. In order to make something fall *into* the sun, instead of falling into orbit around it, we need to do basically the same thing, except the moving truck is the earth and it's going 30km per second. | 2 |
dbf069 | Biology | What exactly is a muscle knot? What causes them and why do massages relieve them? | Muscles are like strings. they only pull in one direction. We have lots of muscles so we have lots of freedom of motion. When muscles are repeatedly needed to pull, the unsconscious brain decides to send signals so that some of the muscles are already pulling. This makes the whole action easier. Muscles pull their ends closer to the middle which means the middle "bunches up." Knots are the bunches of your muscles that your unconscious brain has told to remain clenched. Massage fixes this by literally squishing that clenched knot so the muscles can go back to their resting position. Since the clench was caused by our unconscious brain, we cant just think "release" but rather need some external pressure to squish the knots. I am a LMBT and have worked independently as a stretch therapist helping people develop better neuromuscular connections to fix their posture and any resulting pain from it. I've found that the exhale is very helpful when trying to release knotted muscles. I also am constantly leaning against a lacrosse ball on the wall to help release muscles that my hands cant reach. | 10 |
93qt8h | Other | Why are standard golf balls white instead of a more vibrant color that's easier to see? I'm sure there's a reason for this, like does it have something to do with the dimples on the ball? It just seems like making them white makes them impossible to see during games. Like sure you might be able to see it better on the ground, but I feel like it's important to see it flying through the air for safety if nothing else. | I've heard that white (being the absense of all color) is the easiest to spot. Unless it's in snow of course. A survival guy on his show tore the white foam out of his neon orange life jacket to use as a signal for help for this reason | 19 |
8koyrf | Physics | If you put a perfectly spherical object onto a perfectly flat surface would only one atom from the sphere be touching the surface? I guess this is just theoretical but I was wondering if there's a definitive answer. | Technically the atoms don't "touch" so it would depend on what distance would define touching. Also, at that level the sphere wouldn't be curved, the atoms would be organized into distinct geometric shapes that depend on the material. Interesting question, though. | 4 |
o4gidq | Biology | why are grocery store strawberries (around here we get Driscoll’s brand) big with a hard white interior? Why are they so different than homegrown strawberries? Even when overripe/rotten, the insides seem to be white. Compared to homegrown strawberries, they are flavorless. Are they a different variety? | 2 things at play. Being picked too early so they are hardier for travel and have more time before they spoil. Being bred for hardiness and pest resistance rather than flavor. | 4 |
6i63ci | Other | How can LexisNexis only provide full details of your personal file to you (i.e., you can't order someone else's) after filling out lengthy paperwork to prove who you are, but happily sell your information to a company without your consent? | You can totally look up other people's personal information on LexisNexis. Law firms do it all the time to learn things about someone they expect to sue, such as their address or how much property they own (as a proxy for how wealthy they are and, consequently, whether they will be able to pay a judgment). | 16 |
8gzbvc | Other | Why aren't jurors eventually allowed to ask questions of each side's lawyer, like towards the end of a trial? | Depending on your jurisdiction, they can. Specifically during the jury deliberation, a jury can ask the judge questions, the attorneys questions, and sometimes the witness questions. Obviously some questions can't be asked and some can't be answered, but it is allowed. | 15 |
jlyeg1 | Biology | Why do people get tired/fatigued more easily as they age? | Poor diet, poor sleep, no exercise, lack of continued learning, no meaning or passion for life. | 20 |
iq9q7q | Biology | When we're born are we in peak condition? If not, why? | What do you mean by peak condition? Like, peak athletic condition? No, babies are not the best athletes. Peak neuroplasticity? Kind of, babies learn a lot really quickly. There are a bunch of metrics that you could use. | 3 |
86fa3b | Other | When LED lights spin in one direction, why do they appear to switch direction after a few seconds? | Your eyes aren't exactly like a camera, but it's close enough. When a camera takes a video, what it's really doing is taking 30 pictures every second, then playing them back to you at that speed. But if an object is rotating at that same 30 times per seconds, then in every image the camera captures the object is in the same spot, and so it appears to not be moving at all. If an object is spinning slightly slower, then the object will have completed slightly less than a full revolution in each picture, which makes it appear as though the object is rotating backwards. | 2 |
en7bg4 | Engineering | how do hydrogen-powered cars work, and are they a considerable competitor to electric vehicles? Are hydrogen-powered cars even a thing? | Hydrogen can be used as fuel for combustion engines that are very similar to the fossil-fuelled ones. But another, less mechanically complex solution is to use hydrogen as fuel for a *fuel cell* which creates electricity that powers the car. So in that case, the car is just a normal EV where the large battery pack is replaced with a hydrogen tank and a fuel cell. | 3 |
bg6z3a | Biology | Why is the skin on our lips a different color than the rest of our face? | Because the skin in the rest of our face has more melanin to give it color. In areas like the lips, there’s less melanin, so you can see the blood cells more clearly, and that’s why lips look kind of reddish. | 2 |
kmxyxb | Technology | At what point, and how, does computer hardware touch/move/influence the software? | Software is usually just a list of instructions for the CPU to do, and the CPU just runs those instructions. Sometimes there is instructions for the graphics chip/card, or sometimes those instructions tell the operating system to write to disk. But it’s still just a list of instructions the cpu knows how to execute. Excellent video on how these instructions look if you are interested: URL_0 | 2 |
ke5fik | Technology | In a time where manufacturing took way more time than it does now, why were antiques so opulent and detailed? Simple things like scissors made to look like a bird’s beak, embroidered everything, scrolling details on metal spoons and clawed feet on furniture... tiny buttons, fancy thimbles! Why so many details for every little thing? Might be a silly question, sorry. | It’s a good question. But the answer lies somewhere between the fact that modern fashion tends to be more minimalist and that back then people put more time and therefore, love into whatever they were crafting. It’s perhaps a chicken and egg thing here. I would say the latter is more accurate an answer and that our minimalist styles perhaps were born from mass production. I think if I were hand-making a button or a spoon and it had taken a lot of my time and attention I’d perhaps want it to stand out a bit. I think the fact that antiques are unique and detailed reflects the love that was put into it and it’s no surprise that antiques are so sought after in the modern day - in a similar way people want to be different in a world that is unfortunately driving us towards uniformity and dullness. As a quick example, long ago there would be millions of shops making spoons, now I imagine most will come from a handful of companies like IKEA and be distributed by Amazon. I think much like a lot of other things, manufactured goods are suffering an identity crisis. | 6 |
l5tr0u | Other | Why is filibustering a thing? | The ELI5 explanation is that Southern Democrats wanted to block all civil rights legislation, so they gradually changed the Senate rules (which did not have a filibuster at its creation) to allow a small number of Senators block any bill they didn't like. And that's not grandstanding, that's the actual reason. | 3 |
m87u3y | Technology | How do computers and phones keep track of the date and time, even when they're completely shut off? | Cell phones are connected to your providers network. Atomic clocks at the local phone office keep time for the entire network. [What You Should Know About Stratum System Levels ( URL_1 )]( URL_0 ) | 5 |
7abvq2 | Economics | What is the point of the standard deduction in tax returns? | The Congress created the standard deduction in 1944 to make tax filing simpler for most Americans. Rather than keep receipts and fill out complex paperwork to file for dozens of specific deductions, the standard deduction allowed a taxpayer to just reduce his/her taxable income by 10%. The Congress in 1964 changed the deduction to a dollar amount, so as to permit the poorest Americans to avoid paying taxes altogether. The deduction still serves those dual purposes today -- making filing simpler for most Americans, and eliminating tax liability for the poorest Americans. URL_0 | 1 |
f6st9t | Biology | what is the biological purpose of a headache? | Many different reasons. Mine are normally to tell me I am dehydrated and need fluids or that I am extremely Fatigued and need sleep. | 1 |
c5wrgh | Culture | Why does the US have so many federal law enforcement agencies, many with overlapping objectives instead of having just one or two for all crimes? You got the FBI who investigates all federal crimes including drug and weapons trafficking but the DEA also investigates those things, the ATF pretty much does the same thing as the FBI as well and so on. Why have so many different agencies that besides a few minor things, mainly investigate the same things? I understand the Air Marshal Service and Border Patrol but cant the FBI do what all the other agencies do? | Lawyer and former state-level prosecutor here, How: That's the way history happened. The Federal Gov't has limited power, and didn't really do much in the early years, e.g., under Pres. Washington. Each time a need for a specific task would arise, say to investigate counterfeiting, a new police force would be born! Here, the Secret Service. This happened in different Fed'l offices for different reasons throughout US history, giving us countless Fed'l police forces, each with overlapping authority and jurisdiction. & #x200B; Why it's arguably a good thing: Every organization is prone to "group think," where everyone in a group develops similar perspectives. By having separate groups independently doing their own thing, redundancy becomes built into the system. & #x200B; edit: clarity | 4 |
605vrq | Culture | Why do people only fill half the glass when pouring wine? | Part of drinking wine is the smell. If you fill the glass, aroma can't accumulate for you to smell as you drink. | 3 |
agmtxx | Technology | What network did 70’s and 80’s car phones connect to? How did car phones call people back in the day when there weren’t cell towers all over the place? What were they connecting to? I’ve heard there were car phones as far back as the 1960’s. How could they get on a network to call people that were on landlines? | There were cell towers, there were just fewer of them and they weren't available in as many geographic areas. To make up for the sparse distribution of cell towers, old cell phones had far more powerful radio transmitters (about as powerful as CB radios) so that they could broadcast over a much farther range in order to connect with a tower. | 2 |
86u5pp | Other | If we can feel the sun so hot down here on Earth, why is it so cold in space? | We're thinking about this wrong. Space is neither hot, nor is it cold. It is simply a space. The notion of *hot* and *cold* refer to our own perceptions of how much energy the environment surrounding us is sending our way in the form of heat. When the ISS is facing the sun, the temperature can be as high as 250 degrees Fahrenheit. It can well below 200 degrees below zero on the other side of then ISS, even when it's in sunlight. That's because the vacuum of "space" has very little ability to transmit or carry heat. If the ISS were in the air, and exposed to sunlight, it would also heat the air around it and that air would disperse the energy more evenly. That's why when you're standing on the ground and face the sun, it's not 200 degrees hotter on your face than your ass. ;) Also when you have a medium like air, it retains heat and will continue to disperse it after the source of heat (the sun, usually) has disappeared. That's why it's warm after sundown on Earth, but when the ISS goes into shadow, it's almost instantly plunged into horrifically cold temperatures. But the hot surfaces of it will continue to be hot for quite a while because they can't radiate that heat into space- there's no place for it to go. Many space vehicles have complicated radiator systems to increase surface area and allow the dispersal of waste heat into the extremely thermally insulating environment of a vacuum so they don't cook. | 2 |
lzzwxm | Technology | Why do streaming services care about the number of episodes viewed in a sitting. I like to have background noise throughout the day which results in Netflix and Hulu continuously asking for me to “make sure I’m still here”. My question is why does it matter to them? | Using their service costs them money for bandwidth or whatever. Streaming to an empty room or to a sleeping person costs them more. | 2 |
6vf9az | Economics | When a new currency enters the global market, how is it decided how much it's worth? Example, let's say kosovo makes the kosovosian dollar. Can kosovo just say that their money is worth the same as an American dollar, or maybe 5x an American dollar, or what? | Yes, they could. What you're describing is called "pegging", which is when a country "pegs" their currency to another at a fixed rate. Many countries do this for various reasons, they usually peg to the American Dollar, Euro, Pound, or another major currency. The other way to do this is through the free market. Currency is a product just like any other, supply and demand will set the price just like any other good if left alone. In practice, most countries are somewhere in the middle of the two options: they allow the free market to determine the price, but their central banks also intervene to keep the price in a certain range. | 1 |
dn6tnm | Physics | Often when you step in a shower with a curtain and turn the water on, the curtain billows inwards towards you. Why is this? | More important question, what kind of monster waits until they're fully in the shower to turn the water on? Don't you let it run to heat up some first? | 5 |
mtmd1i | Physics | Photons have no mass, how can they transfer momentum to solar sails? In my head it always made sense that you need mass to transfer momentum. | The equations you learn in basic physics are just approximations that work for most ordinary things. They're technically not correct, though, particularly when you get to extreme energy/mass levels or something very small. Photons have momentum, and so they can transfer that momentum. Their momentum is given by a constant times their wavelength (which basically describes how energetic they are). This is observable when light (photons) knocks out electrons from their orbit. And maybe it helps to explain why this all works out by again pointing out that while they have no mass, they do have energy. And transfer of momentum is also about transfer of energy. | 1 |
7xa9vp | Other | Tenure. How did it come about? Why is it still a thing this day that you can be so terrible at your job and still keep it because of tenure? Why does no other job have this? | Another reason I haven't seen cited here is wages. Organizations, in trying to keep wages down, would find it in their interest to fire people after a number of years of inflation-adjusted salary increases. Entry-level wages often don't keep up with that. And there's an assumption built into agreements that longevity increases value, which is at least generally true, with obvious anecdotal exceptions. So in part, it's a way to prevent age discrimination where they could fire anyone who reached a certain age and salary level. | 5 |
65ymro | Other | How were airports different pre-9/11? | I can remember meeting family members at the gate when they arrived. I was pretty young at the time but I can remember walking around the terminals looking for my aunt's gate since she was older and we didn't want her to get lost. | 5 |
62zo55 | Engineering | How can bombs be unexploded? Recently saw an article about the Oxford-Cambridge boat race possibly being postponed because of an unexploded WW2 bomb. I was just wondering how bombs can land and not explode. Also how can bombs as old as these still be active and dangerous? | Sometimes the mechanism just fails and there is no explosion, it's still dangerous because if the contents ignite the bomb will still explode. | 3 |
5u836c | Biology | How does the brain 'click' and come to a conclusion when it receives multiple pieces of information? Why does the brain 'click' for some people, but for others, not so much? I apologize if my question is confusing, but I'm curious how some people will get two or more related pieces of information about something and come to a conclusion, but others who get the same pieces of related information simply can't come to a conclusion? | I'd say it depends on what information one has previously learned and trusts in. If I tell you that "the moon causes the tides" it may click for someone how the moon's gravity can effect a large fluid body on the earth. But for someone who doesn't know how gravity works or who's never heard of the concept it may not click for them how a big ball in the sky can move the ocean. | 1 |
83r8bv | Economics | What caused gas prices to hit $5 in the mid-2000s, and what has caused it to not get anywhere near $5 since? Obviously supply and demand is a huge factor in keeping prices lower at this point, with hybrid and electric cars affecting the cost. So I guess I just mean to ask if there are other global circumstances that have kept price closer to $2 or $3 since then? Has Bush’s war gotten us additional oil pipelines or something? | Shale oil is a big contributor. Since the mid 2000’s, horizontal drilling has allowed access to reservoirs that were previously economically inaccessible, turning the US into a swing supplier that can take up the global slack from OPEC. | 3 |
bw9ie2 | Biology | why is is still hard to fall asleep when you’re sleep deprived? | To keep this as simple as possible for an ELI5, there are a number of things going on in your body that determine when you feel tired and when you actually fall asleep. The two most important factors are your circadian rythym and sleep-wake homeostasis which are supposed to work in harmony to control your sleep cycle. Circadian rythym is like a 24 hour internal clock controlled by your hypothalamus that affects a number of biological functions like your metabolism and hormone release, but most importantly when you feel alert and sleepy throughout the day. Sleep-wake homeostasis is basically an internal measure of how much you need to sleep. This just continues to go up and up the longer you are awake. It gets fairly complicated but both of these factors work together with a number of different areas of your brain when you are getting ready to sleep, making sure certain functions of your body stay active while others are switched off, e.g. the pons and medula signal muscles in your body to relax so that when you enter REM sleep and your thalamus is sending out visual and audio signals etc, you don't start physically running in your bed because you are dreaming you are being chased down the street. The problem is that because this process is so involved, so many different things can disrupt it, either by causing your circadian rythym and sleep-wake homeostasis to become out of-sync or getting in the way of the biological functions that allow the brain to work in the way we discussed to send you to sleep (release of chemicals melatonin and GABA etc). Things like exposure to light, medicines or other chemicals you have ingested, medical conditions, the environment you're trying to sleep in, your diet, how much physical activity you've done and stress can all greatly disrupt these functions. So ironically, if you're super sleep deprived and feeling really tired, you might get anxious about whether you're going to get enough sleep, especially if you have a big/important day coming up. That anxiety and worry could disrupt your ability to sleep even while you lie there feeling more exhausted than you've been all year. It is related to the functions discussed above but there are also electrical patterns of brain activity that play a role in this. This starts to get quite complicated again and I'm already explaining it badly so I'll just give a quick example. The reason why many people find it easy to fall asleep watching tv is because watching tv often only stimulates a very specific and small part of your brain. As the rest of the brain isn't being actively used for anything, the electrical activity throughout the brain starts to die down, triggering the functions that get you ready for/send you to sleep. In the end the overwhelming desire of the rest of the brain to sleep also shuts down the part of your brain being stimulated by watching tv. TLDR; the human body in general, and specifically sleep function, is very complicated and it is hard to give a short answer about what makes us sleepy and how we actually physically get to sleep. The best thing you can do is research the factors that are proven to affect sleep (exposure to light, sleep environment, stress, diet, level of physical activity, etc) and try to control them to the best of your ability. In the end, if you consistently struggle with sleep issues see a doctor as getting sufficient sleep is one of the most utterly important factors in good physical and mental health. The benefits of sleep have been demonstrated over and over and there are also many demonstrated serious negative effects from lack of sleep. On that note, good night and sweet dreams! | 14 |
7visx6 | Biology | Why are insects in warmer climates significantly larger than those in temperate or cold climates? EG - Insects in Alaska vs those in Texas, or insects in North America vs. those in South America or Africa | It takes more energy to survive in colder climates, plus there are fewer sources of nutrition available. Because of these factors, bugs can't grow to larger sizes in the colder areas - they just wouldn't have enough energy to sustain the extra weight and subsequently extra nutrition needs. | 1 |
hunemw | Biology | - What goes on in the brain when spacing out? I’ve always been a fairly spacey individual and have gotten pretty good at getting ‘images’ to play vividly as I imagine many others do. While spacing out, I was curious to learn of the brain’s activity that is at play. Is it similar to the activity as we sleep, thus leading to a loss in other parts like processing information or focussing? Is it related to tiredness or anything else? Any other related information would also be appreciated, and sorry if the question isn’t entirely clear. | Pretty much everything is "conserving" at that point. There's decreased brain activity across the board, more or less. There's a ton of things that could cause this. Perhaps you've been focusing too long, perhaps your body has given your brain some sort of signal that it wasn't expecting, so it kinda "pauses" for a little bit to get back on track. There's hypotheses that this is part of a biological preservation mechanism, as dissociation (spacing out) can sometimes happen during traumatic events, especially in young children. Really, unfortunately, this falls into the realm of social sciences, though, which is not a terribly accurate or precise science. So, we may never know the reason "why" our bodies and brains do a lot of things. | 1 |
6l7f1r | Biology | If my eye pops out of the socket, will I still be able to see? How would it affect my vision and vision field? | Just the eye being out of the socket won't stop you seeing, assuming the optic nerve is attached and the eye is relatively undamaged from whatever removed it. The field of view won't really be that much expanded by being outside the socket, but the lack of muscles and support may allow the eye to deform enough that focus could be thrown off. Stretching the optic nerve is also likely to result in visual disturbance (and emotional). | 6 |
6o2gxa | Biology | Why are there still no antivenoms for a large number of venomous snakes? It would seem to me that if you could produce one antivenom based on one species of a family of snakes that that antivenom would work with the other species of that same family (i.e. antivenom for a pit viper bite would work for a gaboon viper bite). Is the venom of every species of snake so specific that this wouldn't work? | It short, it's extremely hard to make, and yes each kind is unique. These past posts will tell you lots more: 1. [ELI5:How is Brown Recluse antivenin made and why is it not produced in the United States? ]( URL_2 ) 1. [ELI5: Antivenom ]( URL_6 ) 1. [ELI5: How do we make anti-venom from venom? ]( URL_7 ) 1. [ELI5: How do they go about creating snake anti venom? ]( URL_4 ) 1. [ELI5: How does anti-venom work, and is it available for every type of venom? ]( URL_0 ) 1. [ELI5: How does one make antivenom from venom? And how was it discovered that this was even possible? ]( URL_5 ) 1. [ELI5: Why is anti-venom (for snake bites) running out and soon be all gone next year, why can't they make anymore? ]( URL_1 ) 1. [ELI5: Why is venom used to make anti-venom? ]( URL_3 ) | 1 |
8d0hi3 | Biology | Why is pneumonia so dangerous to elderly people? | Pneumonia is bacterial infection in the lungs that leads to fluid buildup there. You somewhat drown slowly from it. It is dangerous for everyone, but old people due to having weaker immune systems, accumulated injuries/conditions, and less mobility are more likely develop the infection. | 2 |
6bn3va | Culture | How did the colonizers understand the people in an unknown island that they firstly discover. I was having about this thought, how did they do it. For example: The Philippines were discovered by the Magellan, and of course the island that they landed have some people were they spoke different language. How did they make blood compact and communicate so the people will be baptized to christianity? | Sign language and saying words corresponding to those signs, mostly. Pretty much the way you learn any other language except with no literacy to help. Baptism is less do explorers and more so missionaries that came and settled afterwards. | 1 |
bsy8z0 | Technology | How do the saws used to remove casts not break skin? | Chances are that it was actually an oscillating saw even if it had a round blade. Those just swing back and forth a little bit. That makes them good at cutting hard things and bad at cutting soft things. | 6 |
h7yzp0 | Other | Why does it look blurry underwater when you don’t use goggles? | Water has different density than air so your eyes cannot properly adjust to see through straight water when it's in direct contact with your eyes. Goggles add a layer of air between your eyes and the water, so your eyes are able to see through the air properly and into the water, just like if you were to look into water from the top. TL;DR: water thicker, confused eyes. | 1 |
5x26me | Repost | Why does the US debt keep going up? Will it ever be repaid? Will China ever stop lending? | This is not a direct answer to your question but just a correction of one of your assumptions. You mention China assuming (as many people do) that borrowing from China is significant. This is not the case. The US national debt is about $20 Trillion (2016). Of this Japan and China each hold about $1 trillion each. That is only 5% of the total debt so China is not the biggest lender by any means. The overall debt breaks down (very) roughly as follows: * Intragovernment holdings: $5.5 trillion (mainly government trust funds & retirement funds) * Public held debt: $8.0 trillion (federal reserve, mutual funds, private pension funds, banks, insurance, private investors) * Foreign governments & investors: $6.5 trillion (China, Japan, Ireland, Brazil, Switzerland, UK, etc) So most of the money is owed to organisations both private and public within the US. They in turn get their money from the American public as investments, savings, pensions etc. More information [here]( URL_0 ) | 3 |
kwamb7 | Other | How do nature documentaries avoid disrupting the animals? | You try to be unobtrusive when you're filming, and you can use concealed cameras, but sometimes they just have to go in and shoot for days, or weeks. The first several days, the animals are noticing you're there, and they're weirded out and you get bizarre footage of animals staring at you. But if you're in the same spot day after day and you never bother them, eventually they decide you're not interesting and they get back to normal behavior, and now you can get footage that's actually a decent representation of the animals. | 3 |
m6jobl | Chemistry | When filling up the car with petrol, how come you can see shadows of the fuel gases, it not actually see the gases with the naked eye? | Pretty sure the vapors are colorless but it they have a different density than air, which causes light to warp as it passes through them. I’m guessing if you got your head down there and really tried to look directly through the vapors, you’d see distortion similar to a heat shimmer. | 2 |
ixjedr | Technology | What is the difference between Metadata and Data? Particularly in regard to Australia's laws on data/metadata retention by Australia's National Security organisations. | Metadata is data about the data. For example, you make a phone call. The phone call and conversation itself is data but who you called, from where you called, how long you talked etc is the metadata. | 3 |
eyfqh9 | Other | What is the purpose of the massive honking horns on semi-trucks? | Those trucks take a really long time to stop, so they need to be loud so people far ahead can get out of the way. Also I think the frequency of the horn is such that the sound will travel longer distances. | 2 |
ko2hhi | Technology | why adobe flash is no longer being used? For that matter what does it even do ?? | Flash was a rich media plugin for the early days of the internet when browser technologies and standards were far, far more primitive than they are now. In that era, browsers were generally only good for reading text, following links, and executing extremely simple javascript instructions or server calls. To watch a video, you had to actually download the file and play it back locally on your machine with your local player. Interactive content did exist, but was incredibly obtuse to build and maintain using the HTML and JS of the era, with very limited graphics rendering capability or dynamic content. The principal thing Flash did, other than be one of the first easy-to-use in-browser video stream plugins, was make it easy to build interactive content and animations. Timeline animations and Actionscript were simple to use, easy to pick up by kids, and resulted in a huge boom of content on the internet, at a time where the only content your average person could 'add' to the internet would be a forum post on a BBS. Now you had a raft of games, videos, animations, voicework, just this huge flourishing of amateur content built by people for other people. As internet standards caught up, Flash became obsolete as a way to develop rich media, as it was slow and proprietary. After a point there was nothing Flash could do that you couldn't do yourself with a bit of work in JS, and its ubiquity resulted in it being targetted constantly for attack by hackers. There was an era where the easiest way to compromise a machine was to feed it a fake Flash plugin update and get the user to update, or sneak a malicious flash microapp into an ad delivery network that would auto-load on a user's machine and compromise it. The final nail was when Steve Jobs refused to implement flash support in the iPhone. It was never more than an intermediate stepping stone technology that helped bootstrap browsers into the multimedia delivery apps they are now, and for the time it did it's job well. | 11 |
aistau | Biology | Why didn't humans develop the ability to store protein? Since our ancestors relied on hunting to survive (before learning how to farm etc) and there wasn't a prey to hunt Everytime they would've benefited from being able to store protein to keep their muscles so that they can hunt effectively right? So why didn't we? | You don't really need a lot of protein to keep up existing muscle unless you're really bulky, and that would really be a problem because it would take a lot of calories just to maintain. It's more important to have a lot of calories in reserve to stay alive than it is to have a lot of protein to maintain large muscles. Besides that our bodies can synthesize most amino acids, so a period without protein intake does not really hurt you as long as you have fat/glycogen reserves. | 4 |
f00j9p | Physics | why does hot water look more opaque than cold water? | Does it? If you are talking about hot water from the tap sometimes the hot water is cloudy due to mineral residue which accumulates in the hot water tank. Air bubbles can also cause hot water from the tap to look cloudy. As your water heater runs, the molecules in the water expand and trap any other gasses due to pressure. When you open the tap the sudden reduction in pressure allows gas to separate itself and float to the top of your glass or pot, then escape into the air. If you let it sit for a few minutes the water should clear up. | 1 |
9wpnmp | Physics | What does it mean when they say nothing existed before the big bang? | We don't know that 'before the big bang' is even a sensible concept. Our knowledge of the universe, is necessarily constrained to within the universe, and is insufficient to fully understand how the universe 'came to be' (or indeed, if it even had a beginning). So we don't know what was "Before the big bang" or if there's even such a thing as "before the big bang." | 6 |
jyph3g | Technology | What is it that makes Toyotas so reliable even after many years of use? Large amounts of spare parts made? Manufacturing process? Design differences? | Let me give an example. Volkswagen built a van named LT type 2 back in late 90's and early 2000's. It had a forged engine block and could see a million kilometers with ease. It did not give critical faults or the engine didn't blow up easily. That meant no gain from the engine repairs. They stopped the production of LT and produced the new beautiful Crafter with aluminum engine blocks. Guess what, their blocks started cracking on every 500 or 600k kilometers. This might just be a conspiracy theory against VW, but seeing the professional drivers complaining with my very own eyes proved somehow right those theories. That's where Japanese cars show themselves. Not only Toyota is that reliable, Nissan, Subaru, Mitsubishi and other variants are also quite reliable brands. | 19 |
elhgvx | Technology | Where/how is the internet “stored”? Does it have anything to do with servers? | It has everything to do with servers. Servers are literally where the information that makes up the internet is stored. They're all connected to a worldwide network that we call the internet, and there are pathways through which the data flows from the servers where it resides to your ISP, then to your device. | 3 |
79p50f | Other | When does "opposition research" become "treason?" | You are not allowed in US election to money or any other thing of value from foreign nationals or governments. So something that you could get legally from a US citizen would be a crime to get from a non US citizen. It is a bit more complex that that and green card holders are allow to contribute. | 2 |
k66164 | Mathematics | The probability of rolling the same number on a die multiple times in a row & pre-rolling a number to change odds of the next roll. Specifically I'm asking about this situation that came up during a D & D game: Say I'm rolling a 20 sided die, and I do not want to roll a 1. I know that the odds of rolling a 1 are 1/20. I know that the chances of rolling a 1 twice in a row is (1/20 \* 1/20), which is far a lower occurrence. Say then, before I rolled my "real" roll, I rolled the die again and again until I landed on a 1, then proceeded to roll my "real" roll, would I have reduced the odds of rolling a 1 to (1/20 \* 1/20), given that I've just rolled a 1 prior? This is the logic I'm having trouble reasoning about and I'd appreciate it if anyone could clarify what is or is not accurate about the assumptions being made in this scenario. | *"To be safer, always bring a bomb with you when you fly. What are the odds of two bombs on the same plane?"* Your thinking has the same problem as this faux advice. Your decision to bring a bomb has no influence at all on what other people will do. Your other rolls have no influence on what will happen in that particular roll. The conditional probability of rolling a 1 given that you just rolled a 1 is the same as the probability of rolling a 1 given that you just ate a glazed donut. It's still 1/20. The die has no memory of the past. | 7 |
a09vca | Technology | Do satellites have passwords? How do their owners manage them? | Given that there are lots of satellites, designed by lots of different groups of people, it probably isn't correct to say "yes they do," or "no they don't.". Good chance more than one satellite is running Linux with SSL, in which case, yeah, it's password protected and the traffic is encrypted. The method of communication is entirely separate from the presence of an authentication system, like a password. | 15 |
guyxyc | Biology | Why do people sneeze multiple times in a row? Why never just once? | Most of the time, sneezes continue until an irritant is dislodged or otherwise removed. Because one single sneeze is rarely enough, we sneeze multiple times to remove the irritant. | 1 |
hk0ryt | Other | How is conserving water an environmental issue? Doesn’t it all go back to the water cycle? | Not mentioned yet and one of my pet peeves is 'Captured Water'. Think about all of those plastic bottles floating in the ocean, streams, lakes as well as those that are thrown away into the local waste disposal facility. All of that is water that will never return to the cycle. Add plastic bags and such that will also capture more rain water and it adds up. | 9 |
ikd4u5 | Economics | How does the butter business survive the market when margarine can achieve very similar purpose with much lower price? | Because margarine sucks. It's not a butter replacement. It's kind of like asking why does the milk industry survive when sewage can be bottled at a much lower price? Cos I want to drink milk, not sewage, and the fact I can save some money by purchasing sewage instead isn't worth the fact I have a bottle of sewage instead of a bottle of milk. | 2 |
70iimp | Repost | If the main goal of our brain is survival, why does it let get depressed and in some cases commit suicide? | In a maybe somewhat philosophical vein, our brains hardwired will to live long before we gained consciousness of death. So we have all these survival instincts but are now also faced with knowledge of this inevitable fate. Awareness of death came as surprise to our psyche, evolutionarily, right? On one hand, you can be convinced you keep living after death (perhaps due to strong survival instincts), making suicide trivial. On the other, consciousness of death may convincingly let one overpower their instinct to live as we can overpower other instincts we might consider ourselves burdened with. From this perspective, any justifying reason will do, doesn't matter, whether or not it overrides that instinct is up to/depends on the subject. To escape pain, to escape punishment, curiosity, nihilism, whatever. Not to mention, suicide itself may be an instinct. Cells in our body undergo a process called apotheosis, where they basically self-destruct if they determine themselves to be malfunctioning I guess, for lack of a better word. Also, it's interesting to wonder if an AI that gains consciousness or omniscience might just shut itself off -- maybe without instinct for survival (something all living things have at this point, all else being easily filtered out through natural selection far early on if it ever was there to begin with) the best course of action is just to abandon consciousness. Just an interesting thought experiment at this point I guess, but not an irrational idea in those circles. | 33 |
d6u0i3 | Other | How do recycling factories deal with the problem of people putting things in the wrong bins? | The sorting centers that I have inspected (environmental inspections) have a line of low-wage workers working on an elevated conveyor belt station, manually picking out the obviously cannot recycle stuff and tossing it onto the floor, where it eventually gets scooped up for landfilling. Automated air and magnet separation systems are used for additional segregation. | 24 |
drt92c | Chemistry | Why do softer things like blankets feel warmer than things like rocks? | the rate of heat transfer, you can transmit your skin heat to a cooler rock more effectively than you can to a fuzzy blanket that is at the same temperature. Metal objects will feel cold. Water at 70 degrees will feel very cold because it transfers heat away from you quite well. Also, the blanket keeps wind motion at ~0, so heat is not transported away. That's probably the main mechanism going on in cold air. Probably inhibits radiative cooling of your skin as well. | 11 |
6t0ls3 | Repost | How did it become common place for humans to call their parents "mom" and "dad" as opposed to their actual name? | My linguistics Professor told us that even in completely unrelated languages, their early words to address the parents tend to gravitate towards a certain type of sound. Her explanation was that the lip muscles are one of the earliest muscles the child learns to use, because sucking is important for survival, so bilabial open syllables (open syllable are simple consonant+vowel combination) like "ma" "ba" or "pa" are the easist for a child to learn. "mom" and "dad" would then be the slightly more grown up version of "mama" and "dada". (da is a bit of an odd one out because it's not bilabial, but still relatively easy to learn compared to complex words) Even in languages in which parents are traditionally addressed more formally, they usually start out with easier "baby" words, and adopt the more formal terms later when the child can speak properly. But in many cases, some variation of the babyterms just stick. In short: a baby physically wouldn't be able to address his father as "Alexander Leopold von Großauchenbach", so they just call him "dada" instead. | 19 |
5qe0zg | Technology | why is it that people use underscore "_" instead of "-" when programming On the internet (URL's) you rarely see the "-" while in programming languages i've never seen them, why is that? | "my-variable" is "subtract 'variable' from 'my' " (in many programming languages) "my variable" is often a syntax error, because "my" and "variable" are both seen as variable (or words with special meaning) and the computer has no idea what to do with the two variables (add them? multiply?) "MyVariable" and "my_variable" are both treated as one variable. | 4 |
mqoh9l | Biology | Is there a difference between being thirsty and dehydrated? Like scientifically, biologically - by the time you notice that you are thirsty, are you already dehydrated? | Our "thirst center" in our brains doesn't always work properly. There's a lot of hormones that balance your fluid status, and any number of disorders or stresses can throw this off. Elderly people are especially vulnerable to dehydration because their brains don't always tell them they are thirsty, so they don't drink. If your thirst center worked perfectly, all the time, you wouldn't get dehydrated. There's also a difference between dehydration (loss of H2O alone) and hypovolemia (H2O and salt loss). | 11 |
5zlhoj | Physics | why are wires with current wrapped around a magnet called electromagnets when all wires with currents produce electromagnetic fields | In electromagnets they are not wrapped around a magnet, they are wrapped around an iron core or other ferromagnetic material. When current is applied it turns the core into a magnet (an electromagnet). When the current stops it is not a magnet anymore. You can turn it on an off. You actually don't need the core for it to work, if you just have a coil it's a solenoid. Adding the core concentrates the magnetic flux and makes it stronger. edit : spelling | 2 |
j8egvv | Technology | Why do we have to wait 10 seconds when you restart your WIFI router? | I work for a national ISP in the US. Your box won't completely forget the connection it had for those first few seconds it's off, meaning it might not have to start from scratch when you start it back up. If it doesn't start from scratch, it might not get rid of whatever is causing your problem. That's the official Eli5 that I give to the boomers when they complain about having to wait 15 seconds. The other comments mentioning capacitors and the like are kinda Eli10 imo | 7 |
6byog5 | Other | Why was/is there no special prosecutor for the top secret emails or Flynn unmasking or Clinton foundation? | Well, there is a special counsel for the Flynn matter --- was announced yesterday. As for the others, there wasn't any indication that the Justice Department would be hopelessly conflicted in conducting the investigations, so a special prosecutor wasn't called for. | 3 |
ci4lq6 | Technology | Why do downloads in some websites start "in a couple of seconds"? | Usually it's so they can control the flow of traffic to and from their server so the site doesn't crash from too many connections at the same time. | 2 |
a1g44p | Biology | How does smoking cause asthma? I understand that it affects MCC but how does it 'close down the airways' | Smoking is combustion. Combustion causes a byproduct: the smoke. Smoke is a bunch of small particles. Particles that don't belong in your lungs cause it to react. That reaction can be in the form of an asthma attack. | 1 |
7agpix | Technology | Why do lightbulbs go out, but not the lights that illuminate screens on TVs and phones? Is it even possible for them to go out? | Really the more interesting question is **why do lightbulbs go out** rather than why the light sources in screens don't. Afterall, the lightbulbs 100+ years ago had the same lifespan as modern ones -- why hasn't the material science made any progress there? The answer is that lightbulbs are one of the first, and most egregious case of planned obsolescence. They are *designed* to go out, because if they lasted forever, there would be little demand for new lightbulbs. From 1920s to 1940s the lightbulb makers formed the [Phoebus cartel]( URL_0 ) which explicitly ensured that no manufacturer sold lightbulbs with more than 1000 hour average lifespan. The cartel has gone, but the practice still continues. | 3 |
e9apv4 | Physics | what's the difference between implode and explode | Explode is an outward explosion, implode is an inward explosion. So instead of the object bursting outwardly (that’s an explosion), it’s bursting inwardly (that’s an implosion). Does that make sense? | 2 |
6gm6sx | Biology | What is happening mentally when you learn to ride a bike? How do things suddenly "click" after a hundred attempts and it's suddenly perfect thereafter? | It's basically your brain learning through simple trial and error (mixed with balancing correctly). You try one thing, doesn't work, so subconciously you adjust a bit. The biggest challenge for your body is the balancing. The vestibular system is in the ear area, and it's what helps you balance. That's mainly what your brain is adjusting, going from walking, to now riding a bike, since it is significantly harder to balance on one. It's a similar process when babies learn to walk. Obviously, being on all fours is much easier than two legs. Bonus info: the reason why your brain doesn't forget how to ride a bike, even though you can go years without riding, is the heirarchy in which it remembers. You remember sounds more than sights, for instance. More mechanical movements are much easier to remember (and consequently those areas take up more space in the brain). Playing instruments, riding a bike, etc will be one of the last things people forget due to that heirarchy. | 1 |
gix6k3 | Technology | -how can a phone keep things in ram even when it has been restarted? | It's not. It has to read it from its non-volatile storage (your flash drive) or, less likely, over the network. Your phone has no non-volatile RAM. | 3 |
9vnq41 | Biology | How does medicine become effective in your body instead of just being digested in your stomach? | This is actually a big part and challenge of drug design. How to get the medicine in the right place and how to prevent digestion by the human body. This can be achieved by designing the perfect chemical structure, which is quite hard and requires a lot of research. | 2 |
l2jvge | Biology | Why does direct sunlight make people sometimes sneeze? | It's called the [Photic Sneeze Reflex]( URL_0 ) or Autosomal Dominant Compelling Helio-Ophthalmic Outburst (**ACHOO**) syndrome. The nerve for your eyes in bright light triggers the sneeze reflex as they are right next to each other. It affects 18-35% of people. I'm one of them! | 1 |
o8msat | Engineering | Why is a refrigeration cycle necessary? Why can't the refrigerant stay at the evaporator the entire time instead of being recycled to the compressor? If the cold gas (refrigerant) at the evaporator coils is what cools you, why can't the refrigerant stay at the evaporation cycle the entire time? Why is it necessary to have a compression/condensation/thermal valve cycle? | The cold refrigerant absorbs heat and approaches equilibrium, the same temperature as the environment. At that point it can't absorb more heat. It needs to be compressed and cooled again to be able to absorb more heat. The easy analogy is the old ice-box type of freezer which just used a block of ice to keep the compartment cold. It worked great until the ice melted and had to be replenished. The modern refrigeration cycle makes this replenishment automatic. | 3 |
hwy0cf | Other | How do they decide exactly how much one serving is? | Serving size is based on actual consumption, not calories, or nutriton. The FDA conducts surveys occasionally to figure out what people would typically eat and builds a table with references for different types of foods. Like say candy bars, or cereal, etc. In FDA regulations it's called: Sec. 101.12 Reference amounts customarily consumed per eating occasion. | 1 |
6w78ak | Culture | Why some languages are better for logical or philosophical debate, and some others are better for romantic or emotional expression? I'm HK-Chinese, but I think in and speak English 99% of the time, all my Chinese friends and I who have a certain level of fluency prefer to communicate in English because we find it more adequate for expressing rational thoughts and ideas. I've also heard the same from Arab and Spanish English speakers. But when it comes to emotional whinging or rage cursing, or even just writing a sentimental poem, I find myself switch back to Chinese. Does this have to do with the culture that shaped the language? Or does this have more to do with personal linguistic development? | As others have already pointed out, your perception of English being more logical stems more from your later acquisition of it than anything intrinsic to the language itself. There is a [a fair amount of scientific research]( URL_0 ) backing this claim up. | 5 |
gs4y2e | Technology | What are RAW images and how do they differ from normal images? I’ve listened to many tech reviewers and photo editors saying that RAW images are better and have been intrigued by it. Also what are it’s merits and demerits? | Raw Image is every bit of data the camera sensor captured. Huge files, but the maximum amount of information to play around with when editing. Normal Images (typically this means JPGs) are compressed, so they are much smaller and easier to share, but a lot of data has been lost so they can't be edited as much. | 3 |
fw1yi7 | Biology | How do trees decide when and where their branches grow? | The full answer is pretty complicated, but the short version is that plants have hormones just like animals. They have growth hormones and the ability to sense light and the direction of gravity. Most plants try to grow towards light and against gravity. Many plants also grow more in the summer because they sense that the days are longer. There have been experiments done with plants kept in similar environments but with different durations of light, and it was found that you can cause certain plants to bloom depending on how long the lights are on. | 12 |
l1oei1 | Biology | Why does bad posture feel so.... good. | Smoking DMT makes me really feel my posture and automatically sit upright and put everyhting in the correct position. It's only then when I really f*eel* my posture. | 12 |
6b1dv5 | Culture | What does "shooketh" mean? | Another way of saying shook, like when something exciting or big happens you would say , "IM SHOOOOOOK" or like " I am sHooOKeth" | 3 |
aogflg | Biology | In biological terms, what is the determining factor whether or not you can "walk off" an injury? Is it purely down to each person's constitution, or is there a physical threshold? | Pretty much comes down to can you walk. If you can walk then it probably doesn’t hurt enough to stop you. If you can’t walk then it hurts too much and you need to stop. Whether or not it heals properly is a different conversation. (Disclaimer : I am not a medical professional nor do I play one on TV. I just know that when I broke my ankle I was able to walk it off but it healed wonky and bothers me occasionally, compared to when when I broke my hand and it hurt so bad I could barely stand.) | 3 |
5vyvbc | Other | Why is it called alcoholics anonymous if every meeting starts by introducing yourself? | The anonymity refers to there being no "face" of AA aside from the founders Bill Wilson and Dr. Bob who are now dead as well as the protection you have from having your attendance at meetings revealed to the outside world. You'll hear people use their first and last names in meetings sometimes to acknowledge that they do not feel the need to hide their identity from their recovering alcoholic peers. The general code of behavior by honor system is that what is said in a meeting stays in that meeting, and AA does not share its members names with any outside organization. Although these rules are still adhered to, the "anonymous" idea was much more important in the 1930s when alcoholism was heavily stigmatized and considered an issue of poor willpower or bad character. Hope that helps, feel free to ask any questions. | 19 |
6zmy36 | Mathematics | How did people in the past begin to accurately measure the height of mountains, such as everest? | Also, math and triangulation. Trigonometry has been around a long long time. See, with just one side of a triangle and the angle between it and another side, you can figure out the missing side. So if you make the triangle such that once side is easy to measure, and then you use a protractor and your vision to determine the angle, you can math the height. | 8 |
i1mwgv | Biology | how does your brain suddenly remember something, even after you’ve given up trying to recall it (hours or even days later)? Is some part of the brain assigned to keep working on it? | I find it easier to remember things as I lay down before sleep at night. I do this a lot and it works incredibly well for me. Seems much easier to remember things from the past or small details from more recent mundane life events. feels like my brain is a file cabinet in that narrow space of consciousness. | 14 |
af8bss | Other | What does the second number in music time signatures mean? | I struggled to get my head around time signatures for years, but I've just about cracked it now. As always, a good metaphor helps Compare them with coin change in your pocket. The top number tells you how many beats per bar - so it's like saying you have 6 coins. But that's not enough information to tell you the value of your change, because you don't know what the coins are each worth. The bottom number is which note -half, quarter, eighth etc- is used to measure the beat. In our coin metaphor, it's like saying that you have some 5p coins (feel free to adjust to your local currency). That alone doesn't give you your total cash value either, because you don't know how many of the coins there are. What you need is the two numbers combined - i.e., 'I have six coins which are worth 5p'. Then you know you have 20p in total. In a time signature (let's say 6/8): 'One bar of this song has six beats which are each worth an eighth note'. | 2 |
eg4z1v | Culture | how denim became so widespread and why blue became the color of choice? | Denim became popular in the US during the mining boom of the late 19th century. Until then, pants were mostly made of light-wearing materials like linen which couldn't stand up to the rigours of the industry. A tailor called Jacob Davis made a pair of denim trousers by special request and when other people found out about it, demand skyrocketed pretty quickly. Unable to keep up alone, he made a deal with Levi Strauss & Co. and together they started mass-production in San Francisco. Various mining industries continued to boom for the next hundred years or so and during this time, jeans became the staple for working men all over the States. | 8 |
b4944y | Biology | Cloning Myself | You could have a clone daughter, by taking one of your egg cells and replacing it's DNA (1/2 the code needed to make a human) with the DNA from one of your other cells (which is enough to make a whole human). If this fertilized egg was implanted in you, it would grow into a genetic copy of you, only many years younger, of course. This would be a profoundly unethical and usually illegal thing to do, so we're just discussing the concept abstractly. It would not be a "copy" of you, it would be 20+ years younger. It would not experience what you experienced, presuming your mother wasn't some 20^th century rouge genetic scientist. It would be a separate person with your genes. It's no more a product of inbreeding than you are (not wanting to dig into your parent's genetic relationship to each other, let's presume not). | 2 |
5xmk7g | Biology | Why do we have 2 nostrils instead of just one big one? | This is not an answer, but I'm sure you have plenty by now. This is a story: One time I was taking a customer's coffee order, and I found it a little difficult to understand him. I ask him politely to repeat his order and I see him wipe his nose with the back of his hand. That's when I saw it. The guy had just one big nostril. He had no septum in his nose, it's just like he had a normal nose but it was hollow. The way it flattened when he pressed the back of his hand against it was so bizarre. It appeared to be the cause of his speech impediment also, as it changed when his nostril was closed. Just thought I'd share that tidbit here, as apparently some people DO just have one nostril! | 4 |
k81r6f | Biology | Why does it hurt to look into bright things like the sun? | Because you are damaging your eyes. Pain is the body's way to get you to stop hurting yourself. | 3 |
6akq7m | Culture | Why do the Men in the English Royal family have so many war medals even though they probably never went into battle? | They routinely do. The king being present on the battlefield has a long tradition. 15 monarchs from England or Scotland have been killed in battle. Presently Prince Harry is a veteran of the Afghan War. | 4 |
eog1b3 | Physics | Why are icebergs raising water levels? | It's not the sea ice that is causing the sea level to rise for just the reasons you mention. Ice basically displaces the same volume of water. What is happening is that ice that is miles thick and has been locked on land for millions of years in places like Antarctica and Greenland is now melting, and that does cause the sea level to rise. Once this process really gets going (we're probably past the breaking point), it creates a feedback cycle that causes even more ice to melt, speeding along the process. When all that enormous quantity of water enters the ocean, we're in trouble. | 3 |
k5corq | Economics | How come the IRS knows if your taxes are wrong, yet you still have to do them yearly? | The IRS usually knows about the major stuff: salary, whether you bought a home/car/etc, that kind of stuff. Filing your own tax return allows you to make deductions that they wouldn't have known about, for example. If you are a landlord and you put in 10 hours renovating a tenant's apartment, that's tax deductible but if the IRS was automatically doing your taxes they'd never know to deduct that. That's just one example of why you file your own tax return. They know about the major stuff, so if you don't pay your income tax they'll definitely catch you on it. But filing your own tax return (instead of relying on their number) allows you to make small modifications like what I mentioned, stuff they have no way of knowing. So can you make random claims to get deductions? Sure, but they're pretty darn smart and if they suspect that you are making those deductions fraudulently (i.e. lying to them) they'll audit you and thoroughly investigate every single part of your tax return. | 6 |
8d68nx | Engineering | why haven’t we built passengers airplanes with no windows but screen walls on the inside? | Screens would cost more money to procure, build into the plane and maintain. They're also heavier (which leads to extra fuel expenses). Unfortunately, airlines are in the business of trying to cut costs and maximize revenue as much as possible. Some are even already taking out those seat-back infotainment screens for passengers on certain flights, so I doubt we'll see this any time soon, unless they can make a cheap screen that's as light as the rest of the plane frame. | 6 |
6e2i48 | Other | Why ban laptops from flights? Can't a tablet or even a phone be loaded with the malware it would take to bring a plane down? | It is not about malware. It's about the idea that explosives can be hidden inside of the devices / the batteries themselves can be turned into explosives. > U.S. authorities have said the laptop ban for the 10 Middle Eastern and African airports was put in place because of intelligence suggesting terrorists could hide explosives in larger electronic devices. [source] ( URL_0 ) | 4 |
n6x2d3 | Technology | Where does the data go when you format a disk? Let's say your disk is 500 gigabytes. At around %80 percent you perform a disk format. What does the computer do to the 400 gbs of data, to have that disk empty? Also how is it so that the disk don't get full because you already stored around at least 500 gbs of data before? | Write something in sand. Now brush it away. Where did the data go? To the same place as data on a hard drive. | 3 |
8k3nnh | Biology | Do alcoholics metabolize alcohol differently from average drinkers? How so? | There are a couple of effects in your post: 1) BAC: Blood alcohol content, a physical test of how much of your blood is alcohol. 2) how your various systems are affected by a BAC, aka "drunkenness" or alcohol tolerance. Two people with BAC of 0.05 might behave much more differently. 3) Alcohol metabolism, aka how quickly does your body process alcohol and turn it into less dangerous stuff (acetaldehyde and then acetate). Alcohol is absorbed in about ~30-90 minutes (generally 30 min though). At that point, it is in your blood and shows up in BAC tests. While alcohol is in your stomach, it isn't causing any drunken effects. Imagine having a propane tank. It isn't doing anything in the tank. But as it leaks out into their air (bloodstream) it spreads and affects our brains. That is why vomiting shortly after drinking is an effective defence by your body. A lot of alcohol is removed from the body and won't make it to the bloodstream. About ~20% of alcohol can be converted in the stomach through a process called MEOS. So if you have 10 ml of pure alcohol, only 8 ml might make it into your blood stream. Interesting as you drink more often and in high quantities, your body produces more of the stuff needed for the MEOS process. This leads to more alcohol being broken down in the stomach before it ever reaches your blood. Less alcohol in blood means less BAC and less drunk. As well, some people have almost no enzymes needed for MEOS, which means that almost all alcohol they consume makes it to the bloodstream unconverted. Volume of blood increases with weight. For a 200-pound, six-foot male, the blood volume is estimated at 7 liters, For a 100-pound, five-foot female, the estimate is 3.5 litres. bigger bathtub = more water. Assuming the same volume of ethanol is absorbed into the blood, a 200 pound person will have roughly half the BAC of a 100 pound person. Put 5 drops of dark food colouring into 1 litre, and 5 drops of dye into 2 litres. Obviously the amount of dye is the same, but the effect of the dye is greatly reduced and the two litres is less dark. Once it gets into your bloodstream, it can get into your brain and start screwing stuff up. This leads to alcohol symptoms such as balance issues, mood changes, etc. Visible drunkenness As you drink more and more often, your brain gets better at functioning normally despite the alcohol. Imagine getting on a boat and trying to walk around on rough seas with the captain. He is much more stable than you, and appears unaffected by the waves. By being at sea a long time, they have gotten better at compensating for the boats movements. The brain learns to function and adapts to work with alcohol present. This is why chronic drinkers are able to perform tasks normally with high BACs whereas occasional drinkers "appear" more drunk. This is also why chronic drinkers may suffer from mood changes and problems when they aren't drunk, like that sea captain coming back to land and struggling to regain his "land-legs". Lastly, alcoholics seem to break down alcohol in the bloodstream differently. While they convert alcohol to acetaldehyde at similar speeds to non-alcoholics, they don't convert that into the less harmful acetate (which gets converted into water and CO2 and removed). That slower breakdown means that there is much more acetaldehyde in their system. That chemical is pretty bad, and does things like create special opioid like chemicals in the brain (addiction), wrecks organs, etc. > I am wondering if one of the reasons alcoholics end up as alcoholics is because they don’t feel as sick and uncomfortable as nonalcoholics tend to be after a number of drinks. That was long considered a strong possibility. Recently however things like the rising number of Japanese alcoholics (who can get drunk after 1-2 drinks because of missing enzymes), the discovery of alcohol allergies in alcoholics (wheat/rye allergies) and alcoholics perseverance through reverse tolerance suggest this isn't the case. It seems the dominant reason alcoholics end up as such is that the way their body breaks down alcohol creates addictive compounds in their brain and makes them crave them. | 4 |