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l07dwx
|
Why is it gold held and does still hold such value throughout history?
|
Economics
|
explainlikeimfive
|
{
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"text": [
"It's pretty, it's rare, it doesn't tarnish very easily (like the way copper turns green) so it stays pretty. It's workable, so it can be a coin or a thin sheet coating onto something you want to decorate. And it's mostly useless for anything else, so it makes a good proxy for value."
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"score": [
8
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[
"url"
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[
"url"
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|
l07gfk
|
Why do we get a sudden burst of energy wih music?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjs06ep"
],
"text": [
"I believe it has something to do with releasing dopamine or seratonin in the brain, which are pretty much the feel good chemicals in the brain."
],
"score": [
4
],
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[
"url"
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[
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|
l08bsv
|
why are period cramps painful when digestion is not?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjs2hpp",
"gjsl3ea"
],
"text": [
"Peristalsis is a wave-like motion of the intestines that guides food along, and even then digestion can be painful. Cramps are a tight contraction used to force something out. Menstruation is like the uterus version of throwing up.",
"> If pain receptors are supposed to be the body’s warning for something being wrong, and the mensuration cycle has always been a human experience, then why does it still hurt so bad? Ah, if only our pain senses were sophisticated enough to be able to tell \"things that are supposed to be happening\" from \"things that aren't supposed to be happening\"! No more soreness after workouts, or pain from giving birth! But unfortunately, evolution is a slapdash, buggy process, and the weird stuff our bodies do isn't always easily divided between \"right\" or \"wrong\". Take for example what happens when we get sick. Fevers, vomiting, and diarrhea are nasty symptoms, and they can kill you, whether from dehydration or from straight-up cooking your brain. But your body is actually doing those things **on purpose**, to try and either fry the invading bacteria or literally flush it out of your body. Is this an example of something \"going wrong\", or not? Should your body be hitting the \"danger- > pain\" buttons when your temperature rises, even though it's doing that on purpose? Well, your body can't think logically about the answer to that question anyway; it's not smart. It just sets response thresholds for your body's nerves about what conditions should make them activate based on evolution's slightly sloppy best guesses. And, well, you're still alive, so it's more or less getting the job done. Long story short: Periods are an inefficient, inconvenient, slightly damaging process that evolution kludged together to deal with the special problems of our reproductive system. Part of the process involves seizing your uterine and vaginal muscles so hard that they trip the \"ay yo you're flexing too hard\" automatic response from your nervous system. This is inconvenient, but not enough so that it prevented your ancestors from surviving, so evolution hasn't fixed it yet."
],
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69,
27
],
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|
[
"url"
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[
"url"
] |
|
l08i5d
|
What is the superstring theory?
|
Physics
|
explainlikeimfive
|
{
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"gjsl26n"
],
"text": [
"Well, let's start with ordinary, classical particle physics. It uses particle scattering at various energies to find out that some particles, electrons and neutrinos mainly, seem to be \"point particles\" - that no matter how high an energy we've managed to bounce things off them with, they don't react like there's any internal structure at all inside, just the one charged point. Other kinds of particles - pions, for instance, and protons and neutrons - do show internal structure, and \"quarks\" are what we call the apparently-a-point particles they're made of - a quark and an antiquark for pions (and no, they don't last long), and three quarks for a proton or a neutron, both fairly stable on subatomic timescales. Quarks also seem to be point particles under our probing, even though we can't ever see one by itself, we have to probe combinations of them like a proton. Sort of like trying to examine beans when you can't get them out of a beanbag. Anyway ... having these be point particles causes some bits of the advanced math you describe them with to blow up, to give \"infinity\" as a result for quantities that clearly aren't infinite in the real world. There's a process called \"renormalization\" that can comb the infinities out and leave usable answers, but it's nonintuitive ... and sometimes doesn't work. oops. So around fifty years ago, someone had the thought \"Hmm. ... What happens if point particles AREN'T points, way down small where we can't probe yet? What if, instead of drawing worldlines as they move, and interacting at points where three or more worldlines meet ... they are vibrating strings or loops of string? That trace out very very thin tubes, or surfaces, and meet at connections that don't have sharp corners?\" And when you try this, the math doesn't work right at all in our normal 3-space-one-time-dimensions space. ... but can work perfectly, without infinities, in different ways in ten, eleven, or 26 dimensions (one time and the rest space). Perfectly enough that \"...we'd better investigate this further\" was a shared thought among everyone who looked into this. Having too many dimensions can be explained away - if you have some of them be ones that don't go off to infinity in either direction, but rather loop back on themselves, like a ring or a donut. You end up with 22-dimensional donuts, or 6- or 7-dimensional ones, but the math can be done. The remaining problem is that there are WAAAY too many ways to make even a 6-D donut, let alone a 22-D one, and we also can't get the math done _after_ that to handle interactions and get out what the answers for simple ordinary quantities would be, even if we pick a specific teeny donut. So string theory has had a great deal of pure math work done on it ... but hasn't produced any predictions for experimental results at ALL, not even for the particles we know about, that match up correctly. So technically it's still just \"the string hypothesis\", because it can't actually be tested, though nobody calls it that. ...but we don't have any _better_ way right now to solve the math-theory problems with those infinities. ------ tl;dr - string theory tries to develop \"what if particles aren't little points with various qualities, but little strings, maybe looped, instead?\", because you can get rid of some unwanted infinities that way. --Dave, don't EVEN ask about knots"
],
"score": [
18
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[
"url"
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[
"url"
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|
l08jdb
|
If infinite means without an end, how can we say there are infinite numbers between 0 and 1 if we have an actual end (the number 1 in this case).
|
Mathematics
|
explainlikeimfive
|
{
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"text": [
"You're looking at \"the end\" in the wrong way in that example. The end in that case is how many subdivisions there can be between two points. You can infinitely keep dividing it by more and more.",
"Infinite means you can't count it in such a way that you'll eventually stop. You can start labeling the numbers between 0 and 1, say: Number #1 = 0.328739127 Number #2 = 0.3927623362163128888 repeating Number #3 = 0.889328973197362163126381638612783617826387512835173517253812631 and so on, but no matter how many times you do this, you'll always have more numbers to label. As it turns out, the number of numbers between 0 and 1 is actually \"more infinite\" even than the counting numbers {1, 2, 3, ...} - but that's another question :)",
"When they say that infinity has no end, it doesn't mean that there isn't an end point. It means that if you try to count every number, you will be counting forever as it doesn't stop. So between 0 and 1, you might start from 0.1, but there is a number less than that, 0.01. But there's a number than than even that, 0.001, and so on and so forth. there will always be a number that you have missed and thus you will never stop.",
"More like there are an “infinite number” of numbers between 0 and 1. You can just keep adding digits to the end of a decimal point and it would be a new number every time, yet still in between the range of 0 and 1.",
"Draw a line on the floor and walk half the distance of it. Then, walk the half of the remaining distance and keep repeating the process. You'll notice that you'll almost reach the end without actually reaching it. In the case, your starting point is the 0 and the point you were supposed to reach is 1. But you'll never reach 1 if you keep walking those half distances indefinitely.",
"Imagine I asked you to write out every number between 0 and 1. You could start with the obvious like .1, .2, .3, etc. But then you could \"zoom in\" more on the number line and you'll find .01, .02, .03, etc. Then once you get through .99 you can zoom in more to .001, .002, .003, etc. Then zoom in again. And again. And again. In this scenario, there would be no end to your list. Because there are always intervals between any number you can think of."
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4
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[
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|
l08vmz
|
How do gymnast spotters spot potential accidents?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjs5hez"
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"text": [
"They know the trick that's being performed. They know where the gymnast is supposed for the trick to be performed correctly/safely. If the gymnast is outside that spot, then they have to react to maintain safety."
],
"score": [
13
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[
"url"
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[
"url"
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|
l096tb
|
Why do we need to click 'eject' before removing a USB stick?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjs7mlg"
],
"text": [
"Ultimately it's the same reason you're supposed to turn the computer off by selecting \"Shut down\" and letting it do this itself rather than just pulling out the power cable. Except it's specific to the USB stick rather than the whole computer. When you copy or delete files on a disk there's a lot of administrative work that goes into it. The space on the disk is marked as \"used\" or \"free\". The file listings is updated to add or delete your file. The file itself has metadata like the date+time it was created and modified. And of course there's the file data itself. All this data is in different positions on the disk and must be updated, one at a time, because that's how the data is organized. Interrupting the disk by unplugging it or turning the computer off in the middle of the sequence leaves the data inconsistent and will cause problems. When you \"safely\" eject the disk Windows finishes up all the work and actually removes the drive from the disk listing, ensuring there's no more modifications being done and ensuring that there's no half-finished work when the disk is removed."
],
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3
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[
"url"
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[
"url"
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|
l09gx2
|
What actually is balance? Does it work neurologically? How do we lose or regain it?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsaghn",
"gjsiari"
],
"text": [
"Balance mostly uses 3 main senses. The first one is vision, your body sees what is going on and can detect changes. The second is your 'vestibular system', or your inner ear. There is a set of fluid filled structures in there and the fluid moves around. Your body detects this movement and adjusts things appropriately. The third is a sense called proprioception. There are sensors within muscles that basically tell the brain where parts of your body are at any given point. If this position changes (either knowingly or unexpectedly) this feeds back to your brain and it can adjust things appropriately. All this information is handles by your brain, the stuff that happens automatically usually gets handled by a part of your brain called the cerebellum, which helps fine tune movements and coordination. Neurologically, balance can be lost by something impairing these senses or by problems in the brain. Your brain can usually function with one sense impaired, but two or more can really confuse it. Strokes or damage to nerves (pressure on nerves, tumours, MS, ALS) can cause a loss of feedback if it happens along any of the pathways. Nerve compression can be reversed if dealt with quickly enough, but prolonged damage or other causes of nerve damage are often permanent. Neurological conditions like dementia or Parkinsons an also interfere with pathways in your brain and interfere with coordination and balance. These changes are often irreversible, but can sometimes be improved or stabilised with medication. A common cause for balance problems is inner ear problems. This cancommonly be due to infection, trauma, damage to the nerves around this area. Annoyingly, vision is closely linked to your inner ear senses and your brain makes corrections without us realising if it detects changes. Motion sickness is often caused by a difference between what we see and what our inner ear detects, and as we age the fluid in our inner ear thickens so this can make the problem worse. Because of this, if there is a big problem with the inner ear, vision is often affected as well and people get vertigo, or the sensation that the room is spinning as well as loss of balance. This can often be improved with medication. Finally, your body has to be able to respond to all this information. Medications that cause tiredness or drowsiness (opiate painkillers, alcohol etc.) Slow your central nervous systen down and it can't process these changes quickly enough, causing a loss of balance. There are also other conditions that cause falls but aren't directly related to how your body manages balance. Low blood pressure can cause the feeling of light-headedness or black outs, which can lead to falls. Muscle degeneration or weakness can also lead to falls, your muscles have to be strong enough to support you and respond to the changes needed. These are just a couple of examples. It is really important when someone has falls to work out what actually happened, was it a balance issue or an issue somewhere else? Sorry for the wall of text, I hope that clears it up a bit. I tried to be thorough but not overwhelming, I think I probably wrote a bit too much. If you have any questions just ask!",
"The main way balance is sensed is in the ears. There's 3 tube shaped rings (called semicircular canals) filled with fluid, and when the fluid moves the nervous system tells the brain how it's shifted. The body also has sensors called proprioceptors all over the place that tell the brain their position in space. Vision is also important by giving us information about our position that we can see. Over all balance is made of a lot of sensory information being sent to the brain. Losing balance can happen for a lot of reasons, like problems with the semicircular canals and proprioceptors. Regaining balance is actually mostly about strengthening the muscles that help you balance. If you stand on one leg for a long time you use special muscles that you don't often use, and they get tired. If you work them out (by doing more balancing exercises) you will be able to balance better and for longer because they're stronger."
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45,
3
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[
"url"
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[
"url"
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|
l09kz4
|
Instead of making content safer for children, why not just ban children from viewing it?
|
Other
|
explainlikeimfive
|
{
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"gjsj26m"
],
"text": [
"One answer is that creating a foolproof system to ban minors would be overly invasive, too expensive to implement, and might repel some viewers. A more cynical answer is that these websites rely on children for a large part of their income, so have no intention of actually making their website childproof. However, they have to pretend to comply with regulations, so they introduce some decoy measures.",
"It is near impossible to implement a ystem that can ban anyone under a certain age group. Force someone to input birthdate? People can lie. Require proof of age? How do you plan to implement that? Also, someone can use a different ID. Basically, for every measure a website can reasonably put in to exclude children, there is a workaround."
],
"score": [
11,
3
],
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[]
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}
|
[
"url"
] |
[
"url"
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|
l09oxs
|
Why do people get nosebleeds as a kid but not as an adult?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsgoqg",
"gjsawe7"
],
"text": [
"The blood vessels are still new and thin, digital manipulation can have an impact but any sort of trauma(like face planting) can rupture a vessel and healing takes a long time and the scab is now easily disturbed making future nosebleeds more likely, especially in dry weather. Eventually the vessels will heal enough to no longer be easily disturbed and more 'body' will grow around the vessels to protect them, and of course the vessel themselves will grow thicker.",
"Less digital trauma as an adult? ( less nose picking?)"
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"score": [
8,
4
],
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|
[
"url"
] |
[
"url"
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|
l09x0h
|
Can someone please explain to me what a yee yee ass haircut is?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjsbo3r"
],
"text": [
"It's a reference to a scene in grand theft auto 5 where one character explains how the other's haircut makes them less sexually attractive to the opposite gender."
],
"score": [
7
],
"text_urls": [
[]
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|
[
"url"
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[
"url"
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|
l0a51e
|
Why can't you put silicone products next to other silicone products?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjsi9bt",
"gjsf42m"
],
"text": [
"Not all silicones are the same and most often, they react with each other when in contact with a different silicone. This reaction can essentially melt one or both silicone object.",
"A lot of flexible plastics are made so by impregnating an otherwise stuff polymer with a liquid known as a plasticizer that sort of \"lubricates\" the molecules sliding over each other. If it leaks across from one product to another it can be a problem."
],
"score": [
4,
4
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[]
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|
[
"url"
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[
"url"
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|
l0aeb1
|
How does stainless steel stay stainless?
|
Chemistry
|
explainlikeimfive
|
{
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"gju5c4l",
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"text": [
"So all metals, other than gold really, corrode. That is they react with oxygen to form some sort of metal oxide, which is basically saying the burn very, very slowly. A metal oxide is sort of like a rock or a salt. That's often what the ore we mine it as already is, or similar enough. Let's look at iron. It rusts (corrodes, but specific to iron), which turns into flaky red/black stuff, that falls off and exposes more iron to rust further. Let's look at copper. It doesn't corrode as fast as iron. And it turns into this green coating (look at the statue of liberty), which doesn't flake quite as bad as iron. Let's look at aluminum, it doesn't rust/corrode, right? Wrong. Aluminum corrodes very fast and any aluminum you have ever seen is \"rusted\". Except the \"rust\" forms very fast and sticks to the aluminum very well. This provides a very thin and very protective layer that prevents the rest of the aluminum from corroding further. So the key to being a corrosion resistant metal (gold aside) is to have a thin layer of \"rust\" that sticks to it well and prevents further inwards metal from \"rusting\". So what is stainless steel? It's iron with at least 10% chromium, and some other things. 316L stainless steel (there's many different types of stainless steel, but this is a common one) is about 16% chromium, 10% nickel, 2% molybdenum. Even regular old rusting steel is still an alloy, it has more than just pure iron, like carbon in carbon steel obviously. The chromium does the same thing aluminum does, forms a thin and hard layer that protects the chromium and iron from further corrosion. What if I scratch the layer? Shouldn't it rust then? No, because the chromium is throughout the stainless steel. Scratching it will just form a new protective layer anywhere. This is unlike galvanized steel, where iron is just coated with zinc. Scratch the zinc off and the iron will rust, the zinc is only on the outside. But this doesn't mean stainless steel is corrosion proof. Given time, water mixed with some other chemicals will corrode it. Some strong acids will make it rust pretty easily. Stainless steel is only stainless under certain conditions.",
"The chrome in stainless steel oxidizes. The difference with iron is that chromium oxide has the same volume as chromium so the oxide coating is not expansive",
"I think the answer to your question, not what is stainless but how is stainless stainless, is a combination of the answers already here but they all are missing one key component in making stainless stain less: passivation. When you make the stainless steel, it's a mixture of all the ingredients pretty evenly iron, carbon, chromium, molybdenum, and whatever else. The inside and outside look the same. You then process the SS, roll it into wire or sheet or machine it, some even forge it. Depending on what you do, you probably now added a bunch of stuff to the outside like tiny amounts of carbide or iron from the rollers, dies, hammers, anvils, tool steel... just from making the part. So now the outside looks like the inside plus all this extra stuff. Now you have to passivate the part. You want to take all of that stuff off the outside and leave the chromium bits since they form a desirable protective layer if there's room for them to lock together, red rover style. So we clean the part through polishing and then pickle it! There's special machines that use acids to strip the outside of the part of iron and other contamination giving the chromium the best chance to form a protective mesh to surround the part and stop oxygen from touching the iron. ”Red rover red rover, we call Oxygen over!” If you don't passivate, or pickle, the SS then it's just like any other alloy and will continuous oxidize and rust away. This is why your SS fridge and trash cans don't perform like marine SS parts, they manufacturing process is pretty lax when it comes to using proper grade alloys and processing the parts through the whole passivation process.",
"It's called stainless because it stains LESS than regular carbon steel. The chromium molecule is smaller than an iron molecule so the chromium creates a \"matrix\" around the iron, protecting the steel molecules. It's not a perfect seal so over time the iron still breaks down from being exposed to oxygen. It just takes longer. What's a real mind trip is that steel is made by melting iron oxide, adding carbon, then bubbling oxygen through it. But if steel is exposed to oxygen it converts back to iron oxide. The fuck? I'm just a welder so that's a pretty rough run down of it. I'm sure someone much smarter than me could elaborate better.",
"It's the chromium in stainless steel that basically \"prevents\" it from rusting (in the way that iron rusts) Source: Saikon no Qwaser"
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[
"url"
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[
"url"
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|
l0b95m
|
Why do ads load and play quickly and smoothly, but actual content is super slow and laggy?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjsn5nm"
],
"text": [
"Ads are hosted on fast, distributed servers that are made to handle lots of requests per second. Google serves a large share of ads, and their servers are all over the world + they're super beefy. When the content itself loads slower, it might mean the server(s) it's hosted on is underpowered or its network connection isn't good enough to handle the amount of requests coming in."
],
"score": [
5
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[
"url"
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[
"url"
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|
l0bjub
|
Why can't we extract the salt from sea water and use the left over water for drinking?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjsm3uo"
],
"text": [
"We can, google desalination plants. It's just requires enormous amounts of electricity, there are other things in water that also need to be purified, and it leaves you with brine which needs to be disposed of (rather than extracting pure salt, it's easier to convert somewhat salty water to not salty + very salty)."
],
"score": [
3
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|
[
"url"
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[
"url"
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|
l0blqn
|
How exactly do our muscle fibres tense?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsn691"
],
"text": [
"On a molecular level, your muscles are made of fibers of proteins called actin and myosin (among other things). These fibers are arranged sort of parallel-ish, and when the muscle activates they start climbing past each other--think velcro, if it could move like a starfish. When they climb past each other, the entire fiber gets shorter--and thus, so does the muscle, which is what tensing is. When the muscle releases, they let go and can slide back to their relaxed state."
],
"score": [
3
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|
[
"url"
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[
"url"
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|
l0bs5u
|
Why does it feel like time goes by more quickly when you’re having fun, and slower when you’re struggling or bored?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjtb5vp",
"gjsz6lm"
],
"text": [
"Michael from VSauce does a great explanation of that phenomena, asking with some other time based illusions. URL_0",
"I'd say because a watched pot never boils. When you're having fun your mind is occupied on what's taking part in whatever you're doing else if you're not doing anything and your mind isnt occupied it feels as though it takes longer."
],
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4,
3
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[
"https://youtu.be/zHL9GP_B30E"
],
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|
[
"url"
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[
"url"
] |
|
l0cdsj
|
What happens in the body during a seizure?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsrkz9",
"gjt1cse"
],
"text": [
"Seizures are when the electrical impulses in your brains cells burst uncontrollably between each other. This causes your muscles to start behaving abnormally such as convulsions.",
"Neurons in the brain are kinda like switches chained to each other to branch out into multiple paths. One says Yes, does something, and then asks the same question to the next neuron. The next one says No, and so that chain of thought ends. A seizure occurs when the neurons are incapable of saying 'No', and they all keep firing from the signal they just received, essentially creating a recursive/feedback loop. Even when you get to the end of the chain, that 'Yes' signal just keeps firing. And since everything in your body is wired to your brain, now all your muscles are activating and flexing in random directions because of the jacked up orders being received from Central Command. A seizure. Eventually, the brain manages to get control enough to start convincing the neurons to start saying 'No', or the whole thing just shuts down when the person falls unconscious. Seizures can even be limited to specific parts of the brain, causing you to feel like you're dreaming, or to only effect one side of your body. Usually, the brain is able to keep a handle on it with a balance of chemicals and signals to maintain control over the Yes/No signal. Too many 'No's, and you're brain-dead. Too many 'Yes's, and you get a seizure. It's a delicate balance, but it's not something that usually happens without a fault in the system in the first place."
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8,
6
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[],
[]
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|
[
"url"
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[
"url"
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|
l0clzt
|
Why do things bounce?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjstb6f"
],
"text": [
"Basically, one or both of the objects deforms on impact, but being naturally \"springy\" they want to resume their original shape as quickly as possible. As they do so, it generates a force which pushes them away from the collision point. Imagine a balloon inflating, only thousands of times faster, and you can see why it has that effect."
],
"score": [
5
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
|
l0coo2
|
How do eucalyptus/mint scents clear up a stuffy nose?
|
Biology
|
explainlikeimfive
|
{
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"gjt5o33",
"gjtmgfb",
"gju51ts",
"gjtrg6y",
"gjvr8pt",
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"text": [
"Mint and eucalyptus activate the temperature receptors in your nose (or wherever you ingest it), particularly those dealing with low temperatures. This activation is the same effect that happens when you eat a hot pepper, only the capsaicin in the peppers activate a different receptor (ones that respond to hotter temperatures). Since the receptors that are activated are telling your brain \"Hey I'm really cold\", the brain signals the blood vessels in that area to contract to prevent body heat loss. As the vessels contract, the nasal passages open up allowing you to breath easier. *Edit: there, I've corrected the \"contact\":\"contract\" problem lol.",
"The most popular response is wrong I think. Mint/Menthol/Eucalyptus do not actually reduce or clear nasal congeston they simply trick your brain into thinking you are breathing clearly through your nose. I am a Pharmacist and my University Professor taught that menthol and eucalyptus activate cold (thermo) receptors when you inhale them into your nasal passage. These are the same cold receptors that are activated when you are inhaling normally via your nasal passages (focus on it now and feel the sensation of cool air in your nasal passage). The activation of the receptors when your nose is blocked gives you the sensation of achieving adequate imhalation of air through your nose HOWEVER you will also be breathing in through your mouth aswell to compensate for the reduced intake of air through your nose. Doing steam inhalations with or without menthol/eucalyptus can help to clear your congestion as the steam will help to dissolve the mucus blocking the nasal cavity. Psuedoephedrine helps to clear nasal congestion by constricting the blood vessels in the nasal passage and reduce mucus formation. The nasal passagea do not really increaae or decreaae in size it is the amount of mucus up there that restricts airflow.",
"It is likely that eucalyptus/mint scents do not clear up a stuffy nose. An article [ URL_0 ]( URL_0 ) named The effect of inhaled menthol on upper airway resistance in humans: A randomized controlled crossover study looked at the effect on menthol on nasal congestion. Albeit a small study, it showed no statistically different between placebo and menthol. I was unable to find any other study on the subject. The reason many people have responded that it increases vasodilation is because there are studies of topical menthol showing this effect. Although smell is small amounts of the substance reaching your nose, we cant jump to the conclusion that it is similar to topical application. The most likely reason people 'feel' less congested is because menthol (mint) and likely eucalyptus are counter irritants. By slightly irritating your nasal passage, it feels like more air is passing through but in reality you are only sensing the air more acutely. More studies would be required to say that mint clears up a stuffy nose.",
"Aussie bush on the summer rain is my all time favourite smell as an Aussie. I love the smell after a sun shower that comes from the earth mixed with the big gums and iron barks. It's amazing.",
"Fun fact, it doesn't work if you don't have the ability to smell. I tested this while sick with covid.",
"A stuffy nose usually isn't stuffy because it's filled with mucus, but feels stiff because the veins and tissue expanded due to inflammation"
],
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277,
40,
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[],
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"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3628651/"
],
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[]
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}
|
[
"url"
] |
[
"url"
] |
|
l0cp0f
|
how some paralyzed people still walk without sensation while others can't?
|
Eli5: From my understanding, paralysis means that a person has significant limited or diminished sensation or strength. So a paraplegic would be someone that has significant loss of either strength or sensation in the legs. In this aspect, the majority of people are unable to walk/ambulate with no sensation but about 5% can. Why is this?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsttse"
],
"text": [
"Imagine a rope made out of a thousand, or ten thousand threads. This is similar to your spinal cord. If your spinal cord is damaged, some of those threads (nerves) will be stretched, some broken, some bruised. If the entire cord is severed, then everything stops below that point, but if it's only damaged, then the effects can range from mild to severe. Sometimes the cord will regenerate some of the connections, some will stay severed forever."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0cu6v
|
Why are born with wisdom teeth if they’re not needed?
|
Did our ancestors have to use their wisdom teeth at some point in the past?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsu0fi",
"gjsu18b",
"gjtarjm"
],
"text": [
"It's a leftover evolutionary trait from what I understand. With modern advances to medicine and hygiene our teeth don't fall out as quickly, where as back in the day we'd lose a molar or two and regain one with the wisdom tooth. Kind of like the appendix. We used to have a use for it, until our other organs picked up the slack and functions for it, rendering it unnecessary/obsolete.",
"because we used to be harder on our teeth - with diets of tough raw foods, and no dental care - and wisdom teeth served as replacements for all the lost teeth",
"The human mouth has changed significantly in recent history, even compared to the beginning of the industrial revolution. Skulls from just a few hundred years ago show that we used to have larger jaws and more forward maxillas. This is thought to be due to the changes in our diet, modern food is estimated to be over two times more calorie dense as it was pre-industrial revolution. People back then did a lot more chewing and it is thought that the pressure from all that chewing was responsible for shaping the skulls the way they were because the human skull doesn't fully fuse until late adolesence. Larger jaw and elongated maxilla have pretty far reaching effects 1. More room for all the teeth so less chance that they grow wrong and cause the need for braces 2. More room for wisdom teeth as well so they weren't a problem to most people like they are now 3. Larger nasal cavity so less sleep apnea 4. More forward maxilla means straighter noses (as opposed to hook noses) 5. Less crowded temporomandibular joint means larger and more actionated ear canal (aiding its self-cleaning) Also because of far less sugar, people didn't develop cavities as easily. With the amount of chewing that the anatomically modern human has had to do for the vast majority of our history, some extra chompers make perfect sense. Also if you're old enough to read, its probably too late for your maxilla but if you want your kids to be handsome - give them hard to chew foods."
],
"score": [
10,
5,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0cv7j
|
What's the difference between being empathetic and being an "empath"?
|
Every article I can find just says that being an empath means you "feel the other people's emotions in your own body." Is that not just regular empathy? Is "empath" even a real label used in psychology?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjswdk6",
"gjtb9mg"
],
"text": [
"\"Being empathetic\" is the ability to imagine yourself in someone else's shoes to understand how they might feel. \"Being an empath\" is some goofy shit that girls on Tumblr made up to pretend they're witches and now other people think it's a real thing.",
"Empathetic is understanding and empaths are experiencing. They actually feel the same pain they’re witnessing. They would cry and hurt along with the person as if they were going through the same problem. Emotional vampires."
],
"score": [
17,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0cwtd
|
How did our ancestors figure out the concept of glasses to improve eye sight for someone who has crappy eye sight?
|
Glasses have become such a staple for today’s modern life. How was this figured out in the past? Why did they use glass early on and not plastic like some glasses are made today? Why do we still call them glasses if the lens aren’t always made out of glass?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjsuudi"
],
"text": [
"We've had a good enough understanding of how optics work for quite a long time. Ptolemy, who lived in the 2nd century BC, even wrote a book about optics. From there, it wasn't a huge jump to start shaping glass to magnify an image and start holding it in front of your eye. By the 1300's, Venice even started regulating the eyeglass market. They used glass instead of plastic because the first man-made plastics didn't appear until 1862, and they're probably still called \"glasses\" because that's what we're used to calling them."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0d48j
|
Epigenetics
|
What is epigenetics and how does it work? What would be an an example? Thanks :)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjsx412",
"gjtef6k"
],
"text": [
"If DNA is the software, the epigenetic bits are the config files. The epigenetic sections can be changed by events in your life and those changes can be passed on to children. URL_0 Edit: eli5 If your DNA is the gameboy cartridge the epigenetic section is the game save. Pokemon, armor, loot, WiFi settings. 😁",
"The other comment isn't wrong per se, but I feel its analogies are a bit too abstract without explaining the concept itself. DNA stores information in the form of a particular sequence of nucleotides. It's similar to the way computers store information in binary: in a text file, each letter can be represented by a byte that consists of 8 bits, and every bit can be either 0 or 1. In DNA, each amino acid of a protein-coding gene is represented by a codon that consists of 3 nucleotides, and every nucleotide can be either A, C, G or T. You don't need to know the underlying chemistry, only that the concept is remarkably similar to data on a computer. This is genetics: anything to do with the nucleotide sequence of DNA. Epigenetics is a layer of information on top of that. Information that doesn't affect the nucleotide sequence, but tells the cell what to do with it. Returning to the computer example, it's like setting a file to be read-only, hidden, or other such tags. You're not changing the file itself, only the way it's used. In biology, epigenetic information is hugely important in giving cells their role and identity, and making sure they do what they need to do. After all, every single cell in your body has the entirety of your DNA in it. Epigenetics makes sure that each cell accesses the right genes only. There's more to it than that, of course, but this is a good ELI5 start."
],
"score": [
7,
3
],
"text_urls": [
[
"https://www.irishtimes.com/news/science/how-your-diet-could-affect-the-generations-to-come-1.3118344"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0e1e9
|
how come toenails are stronger then fingernails?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjt58we"
],
"text": [
"Toenails are made of more layers and grow slower. The extra layers give them strength, and the slower growth makes the nail stronger Your fingers typically have 1 layer of nail material, your thumb has 2 layers. Your big too has 3 layers of nail material"
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0evbf
|
How come people with OCD can damage their hands by over washing them, but people who (say work with food and) wash their hands many times an hour don't damage their hands?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjt4sjj",
"gjt7hcq",
"gjt4pfg",
"gjt9160",
"gjtcbpq",
"gjtn8m9"
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"text": [
"It has to do with how long each hand washing is and how vigorously they're scrubbed. In food service, they wash their hands as more of a formality. Most of them wear gloves anyway, they don't think about it too too much. But people with OCD scrub and scrub until they feel they meet the arbitrary requirement their mind has made up. 100 scrubs, each finger 5 times, etc etc. The fact that they have a virtually unattainable goal causes them to often times repeat this behavior until they harm themselves.",
"They usually do. It depends on how well you rinse off soap. Using bleach and strong cleaners to clean the kitchen also damage skin. Mine gets much worse in the winter time though. Cold breeze takes off more moisture. I use cream when I need it. I also wash my hands a lot at home and stuff too though.",
"Typically they also wear gloves which traps moisture and sweat. That being said, it still does damage their hands. When I worked in food & beverage, I always had to keep lotion with me because my hands would get dry and crack and bleed (which is then a food safety issue, even with gloves).",
"Worked in kitchens for years and yes, most definitely, kitchen workers hands can get brutally dry. You are constantly wiping down surfaces with quaternary sanitizer using washcloths kept in buckets of said sanitizer. If you don't immediately rinse that stuff off, it dries your skin right up...to the point it can crack. It's not so bad if there's a sink at/near your work station, but often times, you just can't take the time to rinse surface sanitizers off. And don't even get me started on some of the cleaning chemicals we used......",
"They do. Worked in a coffee shop for 4 years, sometimes in the winter my hands would crack and bleed from being so dry.",
"they do get damaged and chapped hands. former chef here. i did get chapped and dry hands from overwashing and others did too. many will moisturise, wear gloves or use barrier cream."
],
"score": [
39,
12,
8,
7,
5,
5
],
"text_urls": [
[],
[],
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|
[
"url"
] |
[
"url"
] |
|
l0ewbo
|
Why do black and white photos look better compared to color during the 70s/80s?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjt65rp",
"gjt7kvu",
"gjtbu1i"
],
"text": [
"Im sure someone here will have a more detailed answer, but generally speaking the black and white film is simpler and had been perfected (as a mass-produced consumer product) many years earlier. They were still improving color film through the 90s, and it switched to digital shortly after. Black and white film is much simpler on a chemical level. One variable: light exposure. How much did this spot get exposed to? Once you start introducing color you have multiple wavelengths of different energies, multiple chemicals to produce different color prints, balancing performance with cost with the type of colors consumers are likely to be using, etc. Plus black and white photography had been around for decades at that point, so long-term issues had been identified and corrected. Consumer-level color photography was still relatively new, so issues like fading hadn’t been identified yet.",
"Partly because the color chemicals aren't as stable and fade and partly because black and white film is more sensitive and only one color so it can have a finer grain.",
"B & W are shot and developed with a simpler chemical process, and this process is more age-resistant. You need 2 colors — white you get from a transparent film, and black you get from a silver coating after a chemical reaction. Color photo is based on the pigments/dyes of different colours. Said pigments are less age-resistant, make the shooting and developing process harder, and the technology wasn't at it's top in the 1970's. Cheap film? A little over/underexposed? Developed for 30 seconds more? Results won't be the best. Source: I shoot and develop film."
],
"score": [
33,
9,
7
],
"text_urls": [
[],
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
|
l0f631
|
How come when the tip of a gas can is lit on fire the can doesn't explode like a bomb?
|
Just watched a video of this scenario and the can just seemed to spew liquid fire rather than explode. Gasoline seems to ignite very rapidly so I question why that property doesn't magnify when the space it is contained in is limited.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjt67tm",
"gjt78i2"
],
"text": [
"the gas that is on fire is mixed with oxygen. If instead of pure gasoline, there was a substance that supplied the fuel with oxygen underneath the surface it WOULD explode like a bomb. If you spread a lot of gas around like splashing it on a big pile of sticks and lit it, it WOULD explode as a lot more of the gas has access to oxygen this is more flammable.",
"There are three components required for a fire. Fuel, oxygen, and a heat source. As the other comment mentioned, burning gasoline is mixed with oxygen. More specifically, gasoline itself doesn’t really combust. It’s the fumes/vapor. Just liquid gas doesn’t really do it. Not only that, but you need the right vapor:oxygen ratio as well. Edit: Not sure what Louis has to do with *liquids*"
],
"score": [
12,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0fnoq
|
Do minors pay need to pay taxes? If so how do you I do it?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjt8lss"
],
"text": [
"I’m assuming you’re in the US? If so, you do have to pay taxes on your earned income. Try out turbo tax."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0h9ed
|
sin etc. in a triangle
|
so im in highschool rn and were doing planimetry, I found stuff about sin and cos in a circle but I have no idea how it relates to triangles, pls help
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gjtgphy"
],
"text": [
"I feel like this is best shown with a diagram. [Here is said diagram.]( URL_0 ) The circle represents all possible triangles with a hypotenuse of 1. You can imagine redrawing the triangle so that it meets any point on the circle. The sin function tells us, based on the angle (called θ in the diagram), how long the side of the triangle farthest from the angle is (when the hypotenuse is 1). For a longer hypotenuse, you must multiply by the length of the hypotenuse. Cosine is, similarly, the length of the triangle leg which connects to the angle."
],
"score": [
9
],
"text_urls": [
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/7/72/Sinus_und_Kosinus_am_Einheitskreis_1.svg/250px-Sinus_und_Kosinus_am_Einheitskreis_1.svg.png"
]
]
}
|
[
"url"
] |
[
"url"
] |
l0hgvf
|
How does gravity really work?
|
Like, I know things with mass attract eachother, but why? What specifically makes them do that?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjtjzai",
"gjy1v8d"
],
"text": [
"Hi! The bets theory of gravity we currently have is General Relativity (GR), which is a geometric theory of gravity. That is, gravity is not modeled as a force in GR, but rather as the curvature of spacetime. # How does Gravity work in General Relativity? To understand how a curvature of spacetime can lead to the effects we observe around us, we have to understand how curved surfaces change the behaviour of straight lines. First things first: an object that has no force acting on it is force-free. Force-free objects do not accelerate and, therefore, move along straight lines. In a flat geometry, two straight lines which are parallel at one point will remain parallel for all times. That is, two parallel straight lines will never cross on a flat surface. So far so intuitive, right? But what happens, if those straight lines do not move across a flat surface, but instead along a curved surface? We call such straight lines on curved surfaces [geodesics]( URL_2 ). Imagine a [sphere]( URL_3 ) with two lines perpendicular to the equator. As they are both perpendicular to the same line, they are parallel at that altitude. Imagine two objects that are moving along the lines perpendicular to the equator. They start out parallel, and move in a straight line upwards. Despite the fact that neither of them is turning, the two objects that started out moving along parallel lines will meet at the north pole. Hence, despite the fact that both objects are force-free at all times, they experience relative acceleration. Such trajectories, that lead across curved surfaces without turning are called [geodesics]( URL_2 ) and they can be thought of as straight lines on curved surfaces. Objects under the influence of gravity follow geodesics. As energy curves spacetime, geodesics can experience relative acceleration despite the fact, that both objects following said geodesics are force-free. And this relative acceleration of force-free bodies is what Newton mistook for the gravitational force. According to GR, though, there is no force, only curvature which causes force-free objects to move along paths that *seem* accelerated to outside observers. #Why does energy curve spacetime? The [Einstein Field Equations]( URL_4 ) tell us, that the source of curvature is given by the [stress-energy tensor]( URL_0 ). However, GR generally does not tell us *why* energy curves spacetime. The rather unsatisfactory answer to *why mass-energy curves spacetime* is, that physics generally does not provide causal explanations, only descriptions. General Relativity is a model of reality, it is not reality itself – just a representation thereof. And this model yields accurate predictions if we model spacetime as a four-dimensional Lorentzian manifold that is curved by the presence of mass-energy. And since it yields accurate descriptions, we continue to use this model until we find an even better one. ----- For a great video on the basics of GR, check out [this]( URL_1 ) video by PBS Spacetime.",
"Nobody said \"cause\". Gravitation sffect is merely \"observed\" under required condition of acceleration or decelleration. It is not caused. The man in the mirror image is not caused by the mirror or the man its just an observational aberation pradox created by the viewer and collectively one event just as gravitation and acceleration are one event - inseperable in my opinion. This is what Einsteins math suggests to me until some new form of math without numerous constants afirms my belief. Keep up your pursuit of knowledge it's a valuable endevour. I am an old hasbeen."
],
"score": [
12,
3
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"text_urls": [
[
"https://en.wikipedia.org/wiki/Stress%E2%80%93energy_tensor",
"https://www.youtube.com/watch?v=NblR01hHK6U",
"https://en.wikipedia.org/wiki/Geodesic",
"http://pi.math.cornell.edu/~dwh/books/eg99/Ch06/3776c40d.jpg",
"https://en.wikipedia.org/wiki/Einstein_field_equations"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0id1v
|
Are bees aware about the consequences of using their stinger on a large target? Consequently, are they aware that stinging smaller animals won't cause them to die?
|
Do they instinctively "know" they will die by stinging a human?
|
Biology
|
explainlikeimfive
|
{
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"gjtnyqd",
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"gjtnuad",
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"gjues30",
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"text": [
"Thinking of bees as individuals is kind of a mistake. Obviously they are, biologically speaking, but a lot of their 'thought' process comes from pheromones and instinctive observation of the bees around them. So you could draw a similarity between bees and cells, with pheromones transmitting information instead of hormones. Think of white blood cells; some are often destroyed when they attack a particularly nasty infection. They aren't 'aware' of it because their programming is only responding to chemical markers.",
"We always like to humanise animals, as if they would think and feel the same way as us. But of course they do not, or at least we have no way of knowing if they do, but most likely they do not. Bees have an instinctive drive to sting enemies if they feel their colony could be in danger, but as to whether they do this full knowing they will die doing so, or if that thought never crosses their mind: we don't know. I personally doubt it, but we can't even really measure this thought process going on in humans, let alone in animals as hard-to-communicate-with as bees.",
"Individual insects don't have an ego they way mammals do. They have evolved to ensure the survival of the hive. So the concept of \"I'm sacrificing myself for the good of the colony\" wouldn't be in the thought process. They react instinctively to threats, even if it means the individual will die, because doing so has assured their survival for hundreds of millions of years.",
"Actually this doesn't happen [with all animals]( URL_0 ). Our and some other animals skin happens to be just about right for the barb to get stuck. I've also read that bees can remove themselves without perishing if given enough time (they spin and slowly get the barbs out) but our usual response is to brush them away so they don't get the chance to do this. Given it doesn't happen with all animals, bees probably don't expect it. But they probably encounter animals where their stinger won't get stuck more often than they encounter humans and other animals where it does get stuck. They probably have to defend from other animals more often than humans.",
"i reckon they don't believe it will kill them: they just think this will make the threat go away!",
"The simple answer is no, they are not. I'll assume you're referring to honeybees since the fact they're a colony superorganism is important. When a guard bee identifies a threat to the colony, whether it's another bee that smells wrong, or a wasp or a badger, she'll first try to defuse the situation by chasing off the perceived threat. If you've ever gotten too close to a hive, you may have noticed that one or perhaps two bees buzz you first, and then they'll head-butt you to try to get you to move away. Only then will they actually sting. Once they sting, the chemicals take over. The venom contains an alarm pheromone which contains isopentyl acetate which smells like pears (to me, at least - other beekeepers have said it smells like bananas). This is produced by a gland next to the sting and it puts all the other bees onto DEFCON 1. Obviously they won't all attack, but a few will, focusing on the original sting area, stinging that again. If the threat still doesn't retreat, more bees will attack and this continues to escalate. At this point, even if the threat does retreat, they'll follow and may sting even when 100m from the hive, but they'll certainly head-butt for some distance. Occasionally a hive will turn nasty, primarily because the queen's genetics are \"bad\" - this often happens because the bee strain is hybridised with another strain. One nasty hive I had decided I was the enemy on the day I had a short-sleeved tee shirt under my bee jacket, so I got about 20 stings on my arms (for full protection you need 2 layers). All of the above behaviours are caused by completely automatic responses to the alarm pheromone with no recognition of the fact that stinging the target will result in their death. In fact, when the sting is ripped out, it's accompanied by a ganglion of nerve tissue which controls the continued pumping of venom into the recipient which indicates that they have actually evolved to perform this post-mortem attack on anything that threatens the colony, i.e. their death is part of the Great Bee Plan. TL;DR - they don't care - it's all controlled by chemical messages.",
"If a Bee stings you. And you dont forcefully remove her. You will see that the Bee will start going in circles around the entrywound and slowly remove the stinger herself. They only die when you try to brush them of and in the process u tear(?) their guts out. (Sry 4 English) So i am going to say that the bee does not expect to die from stinging (even large Targets)",
"Using a human example, if we weren't taught that sex = baby, would we know that having sex will give us a baby? Or would we just do it for fun and a consequence would be a baby. I doubt a bee would know it's going to die, although claiming any certainty on this would make me a fool. I can hardly understand my girlfriend sometimes let alone an insect.",
"Bees aren't self centered creatures. Self survival is less important than the strength and health of the hive. We could learn a thing or two from them.",
"I'm a beekeeper. Many of the responses here re: bees reacting to stimuli, rather than making egocentric decisions, are correct. Bees primarily sting when they detect an increase in pheromones that are released when other bees are squished. That's why many species of bees, especially honeybees, are docile when handled as long as you're gentle. They sting in defense once there's a chemical indicator that others nearby have been killed, and because their instinct is to protect their hive, they will do so without regard for their individual self-preservation."
],
"score": [
1735,
271,
189,
17,
16,
10,
8,
5,
3,
3
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"text_urls": [
[],
[],
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[
"https://blogs.unimelb.edu.au/sciencecommunication/2017/09/04/bee-careful/"
],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0iewm
|
How come we can hold our bladder better when we are sleeping versus when we are awake?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjtoz4e",
"gjtnorg"
],
"text": [
"One of the reasons is there is a hormone produced, Antidiuretic hormone (ADH), in the brain that tells your kidneys to release less water, decreasing the amount of urine your body produces. There are people like myself who do not produce this hormone and it results in bedwetting.",
"Often, your bladder signals to your brain when it is about half full. This means you don't actually need to pee straight away, but it's worth thinking about incase you aren't able to later. So when you're asleep, sleeping is the more important thing to be doing."
],
"score": [
11,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0iezx
|
If our normal body temperature is in the mid 90's, why does that temperature in a room feel incredibly hot?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjtmfg9"
],
"text": [
"Your body is constantly generating heat as a part of its normal function. If it's losing that heat too fast, you feel very cold, and if it cannot lose the heat fast enough, you feel hot. A room that has the ambient temperature close to that of your body with a high humidity level will feel hot because your body cannot get rid of the heat it's generating and will eventually overheat.. Sweating helps, but if the humidity is high enough even sweat cannot evaporate to cool your body down."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0j24a
|
If water is a conductor and eletric eels are eletric, how come you don't get shocked just by being close to them on water?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjtq3jt",
"gjtqpn9",
"gjuhw56",
"gjtqr82"
],
"text": [
"As this is ELI5, I won’t get into too much detail. Basically it is the same reason you don’t get shocked in the air. The eels can only shock from a certain distance away due to the electricity being displaced. Also, nothing is a perfect conductor so there is bound to be resistance. That’s why every single fish doesn’t die when an eel shocks the water.",
"You will but they don’t send out electricity non stop. It’s only for a very short period of time that they trigger this ability.",
"You *do* get shocked. Electric eels are dangerous. They can easily take down large animals. Jeremy Wade of River Monsters did an episode on them. It was a stressful catch. Clip: URL_0",
"Our skin is a resistor to electricity. Electric eels put out low current to sense the environment. It barely registers to us. They only use high current electricity when threatened or to sense/stun prey. Even a full grown eel can't put out too much electricity (860v at 1 ampule), but it can hurt a human."
],
"score": [
7,
6,
5,
3
],
"text_urls": [
[],
[],
[
"https://youtu.be/rkWfxOp6m9w"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0j7r1
|
Why is mental illness so prevalent amongst humans?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjtxxya",
"gjtr2mp",
"gjtrtqr",
"gjtrmyt"
],
"text": [
"Some animals like elephants also get depressed and stuff, as do most house pets. It just happens that humans are much better documented. Animal depression is common and documented in zoos.",
"In the same way that if you have a wheelchair you are disabled but if you have glasses you aren't disabled because societies have accommodated people that need glasses; but we haven't fully accommodated people in wheelchairs. It's like that, our society was shaped in a way where some traits were not just accommodated but encouraged and others shunned and so it doesn't fit with how people naturally are anymore.",
"There is no prescription that says how we are supposed to live. Evolution doesn't work that way. Problem is that human conciousness is a weird thing and very prone to (in IT speak) bugs. It developed very much and in the direction that asks question that it cannot answer thus painted itself mentally in the corner. So it either finds a way to live with that of screams and kicks around hurting itself.",
"The people who are \"fucked up\", at least many of them, are so because they're living among other people who are adapted to different living circumstances. Take [Intermittent Explosive Disorder]( URL_0 ) (Also winning for most accurate acronym for a mental disorder, by the way). Now, in a calm modern country, randomly blowing up at small offenses and responding with disproportional threats or violence is *bad*- it doesn't help the person doing it, or the people around them. However, this trait seems to have some sort of evolutionary basis- there clearly were societies where responding to a perceived threat with immediate massive violence *was a survival trait*."
],
"score": [
14,
11,
11,
3
],
"text_urls": [
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Intermittent_explosive_disorder"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0jgs0
|
What separates a human brain from an animal brain?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjtrh1k",
"gjui443",
"gju15fq"
],
"text": [
"Nothing much, except a larger prefrontal cortex. We are all animals. The brains work the same. Molecular biologist here.",
"The brain has different regions, and each region does its own special task. Evolution built the brain in stages - it added more regions as time went on. Simpler animals don't have as many brain regions as more complex animals, or they do have the same regions but a physically smaller version. Brain signals are just calculations, a region with more neurons can form more complex networks that do more complex calculations. **A lot more details** (I think the brain is pretty cool, so I get overexcited) Even just in the system that controls your movements, one part of your brain plans your movements, another part uses the plans to control your muscles, and another part reads your body's internal sensors to make sure the muscles are moving like you want them to. It's all separated out by function. Other parts of your brain will handle emotions, memories, reasoning, language, or vision. And each of these parts also have specialized sub-regions, e.g. the visual system has different parts to determine where in your visual field an object is vs to identify what object you are looking at. The evolutionarily older parts of the brain largely deal with emotions, and its inputs are a lot of sensory information. Sometimes people talk about how they respond to some primal urge with their \"reptilian brain.\" These are the parts that are physically in the middle of our brain (which can only process emotions - no logic / higher level reasoning) and - incidentally - stripping away all the other, fancier outer brain parts doesn't give you a bad approximation for what a reptile's brain looks like. Evolution turbocharged the mammalian brain by adding the neocortex, which is an outer layer of more regions that do a lot of higher level processing / more complicated calculations. Because the neocortex is just the outer layer of the brain, when evolution wanted to make the neocortex bigger it had to add more surface area to the brain, which it did by adding various folds to the brain. If you look at a monkey's brain, it will have some shallow folding (a little extra neocortex) while a human brain has fairly deep folds (a lot of extra neocortex). You might've heard \"smooth brain\" as an insult to call someone dumb - that refers to a lack of the folds that give us our cortical power. A few more interesting tidbits: * Birds don't have the same brain structure as mammals, but they use different regions to accomplish some of the same tasks * Cockroaches don't have a single central brain organ. Instead they have what we call \"distributed ganglia.\" A ganglion is basically a bundle of neurons, so \"distributed ganglia\" means that nerves are just kind of spread throughout the body instead of centralized into the brain. The ganglia still do various calculations like brain regions do, responding to pain, wind, hunger, scents, and other sensations. * Octopus also have a form of distributed ganglia in addition to a central nervous system - they kind of have a \"mini-brain\" to control each individual arm. Their actual brain sends signals to and from the individual \"arm controller\" brains, which lets the arms handle more complex motor tasks than e.g. our brains could handle when it comes to coordinating 8 almost infinitely flexible appendages.",
"Think of a non-human brain as a pocket calculator from 1985. It can do lots of basic functions. Functionally, as in how the electronics work, there’s not that much difference between a pocket calculator and a smart phone, there‘s just more of it and it’s more complex, which allows for more advanced functions."
],
"score": [
15,
5,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0jhvb
|
() Can pressure melt ice?
|
I know that pressure can make water boil even though the temperature of the water stays the same. But how about ice? Can pressure melt the ice even though the temperature stays below freezing point?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjts3br",
"gjtwei3",
"gjtswz5"
],
"text": [
"I'm not a physicist, but there is thing called [phase diagram]( URL_0 ) for every material. I'm not entirely sure how do you build it (probably requires some if not a lot of practical experimentation), but according to it yes you can melt it into liquid or even make it sublimate with low pressure (transform from solid into gas directly). Water is an interesting one. It's less dense in a solid form than in a liquid and that's weird. Probably the reason why liquid state below freezing point looks like anomaly on that chart.",
"It definitely can, and I think this is why ice skates work as well as they do--the contact area for them is so small that it exerts huge pressure on the ice, melting a patch of it and lubricating the skater's motion.",
"I think you may have it backwards. Water boils when there is a loss in pressure, not increase in pressure. So pressure does not make water boil but rather prevents it from boiling. And if you get the pressure high enough you are able to make the water freeze. This means the answer to your question is yes, and is the same for any material. However water is a very strange material that does not behave similar to any other material under different volumes, pressures and temperatures. And one of the strange properties of water which almost no other material have is that it is possible to melt ice using pressure. If you cool down water until it freezes and then increase the pressure to 100-1000 times atmospheric pressure then the water will thaw into a liquid again. If you increase the pressure even further it will freeze. But you often see this if you try to freeze water in a sealed pressure container. The water will not be able to freeze because ice have a higher volume then water and the container will not allow it to expand. But as soon as you release the pressure the water will instantly freeze. But this is a special property of water and does not work for all materials. And water will still freeze if put under very high pressure."
],
"score": [
6,
5,
5
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Phase_diagram"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0jnmg
|
How can we feel like somebody is watching us?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjtzqpk"
],
"text": [
"It's confirmation bias. There were probably just as many times you got the same feeling but were wrong, but the times you were right stick in your memory much more vividly."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0jx3s
|
How does the body stay warm?
|
How does our body maintain it's warmth? In such cold weather I ask myself how does my body actually warm itself?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjtuccu",
"gjtujdv"
],
"text": [
"We're warmblooded, which means our bodies actually spend a lot of the energy we get from our food to produce heat. The cells of living things contain mitochondria. These are organelle's, kinda like microscopic organs, that produce the chemical energy that organisms use to power their bodies. Warmblooded animals like mammals have many more mitochondria than cold-blooded animals do. All those mitochondria produce a lot of extra energy, part of which takes the form of heat.",
"Consider this: the net chemical reaction in a fire is: Carbon compounds + oxygen = water + carbon dioxide. You eat carbon compounds and inhale oxygen, and later exhale carbon dioxide and pee out water. Although the pathway taken is slower and more complicated, the ultimate process is the same: you’re burning food for energy and heat."
],
"score": [
11,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0k5l5
|
How can I be sure that even if I do not consent, a website won't continue gathering my data?
|
I would expect a company to have as much respect for the "Reject" and "Accept" choices on data collection prompts as a kid has for the "I am over 18" button on popups on porn sites.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjtvs6w",
"gjtznt9",
"gjtw6ip"
],
"text": [
"You can't. You can examine your cookies and check if the site has set a cookie with a long expiration time that looks like some sort of ID, but there are other ways of tracking people online besides cookies.",
"You can either: * Go to the section of your browser that lists cookies stored and see if any are set to that specific website, albeit that doesn't cover third party cookies that may appear in multiple sites or * You can disable cookies in your browser preventing sites from setting them to begin with. Outside of that it's just gentleman's agreement and the very slim risk of someone lodging a complaint. However if a site really wants to there is very little the end user can do to prevent some data collection.",
"> I would expect a company to have as much respect for the \"Reject\" and \"Accept\" choices on data collection prompts as a kid has for the \"I am over 18\" button on popups on porn sites. Not exactly a fair comparison. You put your trust in other people and other companies all the time. You trust the staff at the restaurant isn't writing down the info on your credit card and using it to make online purchases. You trust the car mechanic isn't rifling through your belongings and siphoning away your gas when you leave your car with them. Or taking your car for joy rides. You trust the coat check person isn't searching your pockets, etc. At the end of the day, you can't \"be sure\" they still aren't gathering your data, but at that point it's illegal and companies at least try to minimize the illegality of their actions. At least companies that have a vested interest in maintaining a positive reputation."
],
"score": [
7,
5,
3
],
"text_urls": [
[],
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
l0khh3
|
Why does English invariably demand that multiple adjectives precede its noun in the seemingly arbitrary but non-negotiable order of 'opinion - size - shape - colour - origin - material - purpose'?
|
You can have a 'lovely little old rectangular green French silver whittling knife', but mess with this word order in the slightest and you'll sound like a proper maniac.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjtz6dc",
"gjtxxq2",
"gjurx2j",
"gjtxn19",
"gjtype5",
"gjv3cc2"
],
"text": [
"Well, first off, you're missing four in your description and your example is out of order. And if your example sounds good to you, ask yourself if you're a proper maniac (you're not). You're missing; quantity, which comes first; physical quality, which comes after size but before shape; age, which comes after shape but before color (your examples screws this up); and type, which comes after material and before purpose. Some lists will have them in different orders, this one is from Cambridge University. And the fact of the matter is that it doesn't actually matter that much, it isn't actually a hard-and-fast rule. The list keeps getting longer, too. At one point it was just two things; opinion and then fact. Then it was opinion > fact; qualifier > function. Now it's opinion > fact, qualifier > function, but only for correlatives (adjectives that modify nouns without modifying each other). Operators and cumulative words don't follow this trend. As for why... well, it's a new area of study and no one's really figured that part out yet. We're still studying trends and old texts to see if they follow the example (and they don't, for sure) and even looking at different regions to see if we all do it the same (we don't).",
"Because Language is made by humans not computers and it changes over time so alot of things don't make sense. Even this rule isn't set. You can have a Good little girl and a Big bad wolf",
"Depends on if you buy into universal grammar or not. First, it should be known that this phenomenon is present in many many languages. And that is not a strict process either. You can mess with the order to emphasize or change the meaning a little bit. The \"proper\" order would be the \"ugly, big, green, guy.\", but you might say \"The *big*, ugly, green guy.\" to emphasize that he's very big, or to distinguish him for the other normal sized ugly green guy. So even in languages that have this, semantics kind of overrides it. However, depending on how strictly you believe/buy into universal grammar and Chomskian linguistics, the reason for this is the underlying language process that we have as humans. Universal Grammar or UG, basically posits that humans have the inborn capacity for language, and that this biological structure exists naturally allowing for it to adhere language to this structure to expand the humans ability to use language very very quickly. There are a variety of views on UG, from a more casual interpretation that says basically there is just some part of our brain designed for language and no other animal has it (Chomsky has, over the course of many years, resigned to this position) or a very strict interpretation that there is a set way that every single language works and shares this underlying framework, and that languages just create rules to utilize this framework (Chomsky's original theory, which has gone under **a lot** of scrutiny.) Regardless, the idea is basically that we as humans have some sort of skeleton template in our brain for how language should be structured. And as we learn a language, our brains attach words and meaning to that structure, and we slowly piece together the language. This explains the poverty of stimulus issue with language, children simply aren't exposed to enough language to learn, and yet somehow they do. If there was some underlying structure that words and meaning were attached to, they would be able to build language without being exposed to everything. If this is the case, that we have a skeleton template, something like adjective order would make sense, we learned where words go, after hearing them a few times, and then we just keep that order, and any words that pair nicely with anything section of the template go into that slot, so we end up always using the same order, unless we're trying to intentionally change it up to convey specific meaning. All in all, there likely isn't a \"reason\" beyond that we use a lot of arbitrary rules in language to help us communicate. If there is a universal grammar (no matter how strictly you interpret it) that likely influences how we structure sentences which could contribute to it. But its entirely possible that over time we as the collective speakers of a language implicitly settled on an order, that way we could mix it up when we wanted to make a point. Unfortunately with language, the truth is a lot of the stuff we do is just because we do. Language is a living thing that changes and grows and shifts. Source: Am a linguist who specializes in & researches phonology, cognitive linguistics and semantics/pragmatics.",
"Every natural (I.e. not constructed) language is just a sum of conventions accepted over time by its speakers. There’s history in development of a language where you can trace the development of common “rules” but in general these tend not to do with any particular coherent logic and more with the convenience for use in a context, how such use changed due to different circumstances like mixing with other languages, new terminology development, obsolescence etc.",
"English has rules about adjective order. It’s part of the grammar in the English language that English speakers learn without being formally taught. The adjective types are in a generic order of “importance” - in instances where a lower adjective becomes more defining than a higher one it *can* get promoted to the top. For example “the red big barn” would normally be wrong, but if there were several “big barns” of different colors and and someone asked “which barn is the tractor in” you *could* say “the red big barn”, because red is the primary defining trait, although you would probably just say “the red one”.",
"Everyone else is talking about grammar and such but I want to give you a realistic way this might have occurred. Say originally there was no set order. You could say \"big red apple\" or \"red big apple\" according to whim and circumstance. However, because there was usually no difference in meaning between the two, deciding which one went first took up mental effort for no purpose. You had to spend a fraction of a second thinking about something that didn't matter. So people would generally tend to stick to one or the other instead of deciding each time which to use. Whenever deciding between \"size- > color\" or \"color- > size\", you'd just always say \"size- > color\". And originally this was just on a person-by-person basis. You might tend to say it one way, but your friend might say it the other way. It didn't matter because you both understood each other. But over time, as people picked up habits from their parents and neighbors, it began to feel \"normal\" to say and hear it one way, and \"strange\" to say and hear it the other way. If everybody in your village said it one way, and someone new came in from another region, it was something that stood out and made them an outsider. So either they'd eventually conform, or they'd move on, or they'd forever be seen as \"odd\". So then you'd have regional dialects, where some regions always said it one way and others always said it the other. But it wasn't evenly distributed. By random chance, more (and more influential) regions tended to use \"size- > color\" instead of the other way around. So over time, this usage began to spread and be considered the \"correct\" way of saying it, while the other way was seen as a local quirk, and then as backwards slang. And that's how you end up with a grammatical rule, just by ordinary people saying what came naturally to them."
],
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|
[
"url"
] |
[
"url"
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l0kjxf
|
Why/How do proteins fold, and what causes them to fold the wrong way?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gju1cmp",
"gju9twy"
],
"text": [
"Proteins are made of a chain of amino acids. There are 20 different amino acids, each with a different molecular composition. The interaction between these amino acids is essentially what makes the protein fold and gives it a 3D shape. Let's say in position 1 there is a positively charged amino acid, and in position 10 there is a negatively charged one. These two amino acids would be sticking to each other, forming a loop. This loop is essentially a protein folding based on its charge. Other than this, there are many other types of chemical interaction forming between the amino acids and other molecules in the environment at varying stability, thus there are proteins are pretty dynamic and \"fluid\". They can fold the wrong way if the genetic sequence is wrong. This is basically what a genetic mutation leads to -- improper folding of a protein.",
"The short answer is that we're not entirely sure, and vast amounts of money and computational power are being spent on figuring it out. Protein folding is required to turn a (figuratively) two dimensional chain of amino acids into a specific three dimensional functional structure. While it sounds simple, the complexity of this process is almost unimaginable, and we're looking to machine learning to help us understand it. A misfolded protein can happen for a variety of reasons, both internal (genetic defect) and external (ingesting a prion [misfolded protein]). The reason this is so dangerous is because the human body is a big pile of chemical reactions. There isn't any sort of logic guiding the inner workings of the cells, only the biochemical mechanisms we evolved. For this reason, misfolded proteins just kind of...exist. They won't slot into the reactions they were meant to run, and worse they can induce other proteins to misfold in the same way. Since the body has almost no ability to denature defective proteins, they can build up and cause debilitating or fatal neurodegenerative diseases."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0kzxr
|
Why are shoes not foot-shaped? Why are they made to squeeze the toes into a narrower shape?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gju0v7l"
],
"text": [
"Fashion. Flip flops, crocs, work, hiking etc boots , running shoes etc are all foot shaped. Pointy dress shoes are a question of fashion and choice, not some objective logical requirement."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0la5i
|
Why can’t animals from different species breed with one another?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gju31ke",
"gju40vw"
],
"text": [
"when animals breed something called genetic recombination happens, this means that strands of DNA from both parents mix with each other. The DNA is arranged in a way that only certain parts of it can fit with another. Imagine keys and keyholes. If you don't have the right key it won't fit, so by having different DNA strands you might not have the key for that keyhole and the recombination would be impossible.",
"Simple answer first: the definition of a species is a group of related organisms that breeds only with members of the group, under natural conditions. Therefore, if they could breed with each other, they WOULD be the same species. More complex answer: the genes of an organism are inherited from other the mother and father (usually, especially in vertebrate groups. See parthenogenesis for counter examples). This means the genes from the mother need to be sufficiently compatible with the genes from the father to produce a viable offspring. This can include things as significant as the number of chromosomes from each parent, to more finely tuned matters."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0mfmt
|
Why are we using mRNA for this vaccine and not an actual piece of the spike protein?
|
I’ve taken molecular biology so I know a bit about how this process works, but I’m curious as to why we’re not injecting a piece of the spike protein and are instead having our cells make the protein (or a piece of it) instead.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjuby3m",
"gjubuej"
],
"text": [
"The biggest reason is that the mRNA vaccines that we have, are just the fastest to be developed from the point of gene sequencing. [They have been working on the tech for years already.]( URL_0 ) and the turnaround time for these vaccines is better than that of your more classical kind of vaccine.",
"Your immune response comes from having certain white blood cells determine something is a threat, grab a chunk of it, and then show that chunk to their friends that go out there and do the killing Just presenting the spike protein is similar to the old style vaccine with dead/deactivated viruses, and will cause them to pick up some of them and train some of their friends, but because its a limited threat the response is limited. The mRNA vaccines have been designed so that the mRNA is in a tasty package for those trainer cells to come along and gobble up, and is really neat so they want to show it to as many of their assassin friends as they can. The more cells that have been trained to look for the spike protein, the stronger the immune response if you ever actually encounter the spike protein on a real virus because those cells will immediately know its a threat rather than having to loop back home and report this weird thing they found in the hallway. Basically the mRNA vaccines are trying to bypass some of the standard processes in the immune system and get the helpers to train as many assassins as possible to improve their effectiveness over letting the immune system learn its normal way"
],
"score": [
11,
7
],
"text_urls": [
[
"https://youtu.be/xQGfdwju5C8"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0mkdc
|
why are CPUs and GPUs so hot?
|
Processors are basically really tiny transitors that let electrons pass through or Not. So where does that heat come from?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gju9z4b"
],
"text": [
"When electrons pass through, the current creates heat through something we call the Joule effect. Think of it like the electrons creating friction in the circuit, the same way you can heat up your hands by rubbing them together. Because a LOT of electrons pass through these transistors to calculate, a lot of heat is generated."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0nkb5
|
Is it more fuel efficient to quickly accelerate to a certain speed and keep it or to slowly accelerate to that speed and keep it?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjuh9yl"
],
"text": [
"Physics tells you it doesn't matter, if you want to take 2 tons and get it from 0 to 67 mph (30 m/s) then you need to add 1.8 MJ of energy. Whether you apply that energy over 6 seconds at 300 kW or 60 seconds at 30 kW, the total energy is the same Engineering then pops in to let you know that you're not working with infinite ideal heatsinks and frictionless bearings and that slower is better, but only to an extent Your engine is most efficient at peak torque, that is when you get the most force from a given volume of air/gas. That point is generally around 3000 RPM while peak power (fastest acceleration) is generally around 5000-6000 RPM. It is most fuel efficient to accelerate at peak torque the whole time then drop down into cruising speed, how fast that has you accelerating depends on your car and the engine. Accelerating much slower than that ends up making things worse because your engine consumes a certain amount of fuel just to keep spinning regardless of load so at extremely low load this baseline fuel consumption can dominate the fuel consumed to give you the power and give really crappy numbers. This baseline fuel consumption is another reason why traveling around at city speeds is less fuel efficient than cruising on the highway even if you aren't stopping, while your car does need less power, its not consuming proportionately less fuel because of this offset required to keep it spinning"
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0npoe
|
How does vaporub work?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjupk75",
"gjui1tc"
],
"text": [
"Menthol improves bronchiodilation. Simply put it causes the small tubes that lead to and from your lungs to expand and allow more air flow. Menthol is the main component of vaporub. The method of how this works is in most cases considered to still be unknown. You can also put vaporub on the soles of your feet and it will sooth a cough. Again, no real explanation of why it works. But it does. And a quick Google search with refute the other claim being made that it’s all a placebo effect.",
"It contains chemicals that trigger the \"cold air\" sense in your nose and sinuses. Your brain links the 'cold air' feeling to \"breathing with a clear nose\" so you *think* you're breathing better than you are. So essentially it's a brain - hack, you are not in fact breathing better, it just makes you brain think you are."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0nq7v
|
What happens in our brain when we want to say “mustard and ketchup” but instead end up saying “kustard and metchup”?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjutz5p",
"gjuzfb1",
"gjvg5qi",
"gjutk2z"
],
"text": [
"This is called a [Spoonerism]( URL_0 )! They are studied heavily, and though it's hard to say what the ultimate cause is, the ELI5 seems to be that it occurs most often with words that we think of as a unit, rather than separate. Things like \"ketchup and mustard\", \"barn door\", etc - they are usually spoken together. Our brains and mouths seem to get out of sync and we end up replacing the first syllable of each. In case you're older than 5: - [Here's an article]( URL_2 ) - [And here's a study]( URL_1 ) for more information.",
"Who says 'mustard and ketchup' and not 'ketchup and mustard'?",
"What's happening is your brain wants to say ketchup and mustard and like a normal human being and not some psychopath who wants to say mustard and ketchup.",
"Human brains are lazy. Because of this laziness, most people only process English language as much as they need to: enough for day to day speech. Generally, the brain gives more importance to the letters and syllables towards the beginning and towards the end of the word. Which is why it’s relatively easy to read shit like URL_0 When one thinks of a word they would like to say, the brain usually fires off the first letter correctly then sorta expects the rest of the word to flow out naturally as saying the first syllable is often enough to remind most people of the remaining syllables in the word. However when one tries to craft a more complex sentence, the brain has to think further than the first syllable of the word and this is where people can become tripped up. In my eyes, this looks like an individual who has thought of the sentence they want to say before they do: blah blah mustard and ketchup blah blah and then once satisfied that they have a correct sentence to say they have begun the process of using their mouth to say the words they have just thought of. One small problem, they have already forgotten what order the mustard and ketchup are in and because one of the key first letters needs to be said before a word can commence, a Hail Mary attempt to correct for forgetting the order comes out at the 11th hour as the individual is speaking. This likely impacts the confidence of the individual speaking so as they speak they are freaking out that they forgot the order of the words. The anxiety of messing up their sentence combined with the Hail Mary attempt to correct it is what causes the individual to utter one of the key first letters and hope that correct following syllables will come out of their mouth. However, because saying the first letter does not guarantee the brain will correctly fill in the rest of the word on the fly, we can observe the effects of it failing to do so in this case."
],
"score": [
212,
47,
14,
11
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Spoonerism",
"https://academic.oup.com/cercor/article/17/5/1173/344475",
"https://indianapublicmedia.org/amomentofscience/spoonerisms.php"
],
[],
[],
[
"https://cdn.lifehack.org/wp-content/uploads/2016/07/07070543/Sceince-Explain-Our-Reading-Brain1.jpg"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0nsfs
|
The difference between Duality and Polarity
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjumshh"
],
"text": [
"I would say generally that \"Duality\" refers to things where there is a spectrum or where you can be both at the same time (to use your example something can have both 'good' and 'evil' aspects), while \"Polarity\" would refer to things that are mutually exclusive."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0ntgg
|
Why are tennis balls green?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjuk4f5",
"gjuii5t"
],
"text": [
"Up until the 1970's balls were generally white, it was the invention of colour TV and televised tournaments on the BBC that lead to yellow balls which would show up better on screen. Weirdly David Attenborough (yes the same David Attenborough) was heavily involved with this. Here is an article with more information URL_0",
"Tennis balls are normally yellow in order to stand out against either green grass or red clay courts, green tennis balls wouldn't really be useful."
],
"score": [
7,
5
],
"text_urls": [
[
"https://www.tennis365.com/tennis-features/how-tennis-changed-from-white-to-yellow-tennis-balls-thanks-to-david-attenborough/"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0nwgu
|
Why do people write (he/him) instead of just (he) or (him)?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjuiv69",
"gjuqrtd",
"gjuilw2"
],
"text": [
"It’s for the less common ones where people may not know the matching term. Examples are (xe/xem) or (ve/ver).",
"For people who use conventional pronouns but provide them anyway, the goal is usually to create a space where people with unconventional pronouns feel like they can share them. Someone who uses unconventional pronouns may need to specify all the forms of that pronoun, so the standard way of presenting pronouns is to say them all, even if that doesn't provide new information about someone with conventional pronouns. Be aware, it's not uncommon for someone to give their pronouns as something like \"she/they.\" These people are not asking you to use \"she\" when they are the subject of a sentence and \"them\" when they are the object. Instead, they're expressing their comfort with both feminine and gender-neutral pronouns. This is inconsistent with the above paragraph, but it's important to keep in mind that the idea of choosing and communicating pronouns is extremely new and still being refined.",
"It would likely be context based. \"He/him\" is somewhat redundant, but it tells people that both \"he\" and \"him\" (which have different uses) are appropriate pronouns for that situation. There are cases of \"he/her\" and \"she/him\", as well as \"they/them\", \"he/her/they\", \"he/they\", \"her/they\", and any other combination of those you can think of. It's mostly used to inform others of the pronouns a specific subject prefers to be called by, most commonly when they are in an environment that shows consciousness of appearance not always aligning with gender identity."
],
"score": [
11,
10,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0o9db
|
Why are cotton swabs the shape they are if they are not meant to be put into ear holes?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjukr1h",
"gjukjxg"
],
"text": [
"The pictures on the box of possible uses are a joke. \"Clean between your keyboard keys\". \"Use a single Q-Tip to cleanse your baby!\". The only reason they say that they are not for your ear-holes is that they don't want to get sued. 90% of mine are used for my ears and I am addicted to that. I kind of wish I never started...",
"They were originally created to clean your ears, however after research was actually done into cleaning your ears it was found that it's very easy to cause more damage than you might prevent by using them, hence it is no longer recommended to clean your ears with them (at least not the way most people do - by inserting them into your ear canal). Though, just because something is shaped in a way that makes it easy to use in a specific way, doesn't mean they *should* be used that way. Cotton swabs fit very well up your nose too, but beyond Covid (and similar) swab testing, how often do you use them to clean your nose?"
],
"score": [
13,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0og47
|
If things with big mass attract things with lesser mass, would it be possible that someday the universe is Just one big Planet?
|
For example a small planets get pulled Into A bigger Planet because of gravitation merging both Into a bigger Planet and so on and so on
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjum2xt",
"gjumgq9"
],
"text": [
"First, a small correction, things with mass attract each other. The Earth pulls on you, but you also pull on the Earth. To get at the answer to your question though: Based on our current understanding of the universe we do not expect the long term fate of everything to be being crunched up together by gravity. This is because the universe is, itself, expanding. Objects that are very distant are actually attracting each other more slowly than the space between them is expanding. As such, they're not actually getting closer together. This expansion of the universe is also accelerating, leading some to believe that, eventually, all matter in the universe will be torn apart by the expansion of space. However, the expansion of the universe is one of the most poorly understood parts of the universe, so we're really not sure.",
"No, because we also know that space is expanding at a constant rate. Gravity is proportional to the inverse of the distance squared (i.e., 1/r^(2)), but space expansion is linear (i.e., 1/r). If **r** is big enough, then space expansion will be bigger than gravity. So at a certain distance apart, no matter how massive two things are, they will be spreading apart faster than they are coming together."
],
"score": [
9,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0oh4q
|
What are you meant to think about when going to sleep?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjuqus1",
"gjum3ah",
"gjurfc1",
"gjut7uo",
"gjumedf"
],
"text": [
"I do the [military sleep method ]( URL_0 ) And [train your monkey mind ]( URL_1 ) I try to think of nothing. Imagine staring into a black night sky while floating in a boat.",
"This is very subjective. What will work for me may not work for you. I like to think about what I want to dream about and start creating s random story. Sometimes I like to remember something which brings me to another memory, then another, then another, until I'm remembering something I haven't thought about for years. That last one doesn't necessarily help with sleep. I do find that meditation helps, clearing the mind and focusing on slow continues deepish breaths.",
"The best way I fall asleep is to put myself in another place. Usually this means imagining my bus route from childhood or driving the commute to work in my head. Our spatial memory is super powerful, practically infinite, and so easy to get lost in.",
"As someone else pointed out, this depends on you and your preference, really. I personally find that reading before bed or listening to a good audiobook/story empties my mind of thoughts and fills it with images instead. Thoughts tend to go round and round in my head, but if they are replaced with sounds/ images, they seamlessly merge into dream state.",
"Your body knows what to do. Get comfortable and focus on breathing deeply. Let your mind wander if it wants to. Don’t stress about what you should be thinking about."
],
"score": [
9,
8,
5,
5,
4
],
"text_urls": [
[
"https://www.healthline.com/health/healthy-sleep/fall-asleep-fast",
"https://youtu.be/4PkrhH-bkpk"
],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0oi4p
|
How do immunity boosters even work? (Like those cereals and veggies and fruits)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjum11x",
"gjumvc4"
],
"text": [
"They don't, which is why Airborne got sued by the FDA and can no longer claim their product improves immune function. If you aren't sick, injured, or malnourished your immune system doesn't need any help.",
"Generally speaking they don't. Vitamin C is always pushed, for example, but while there is good evidence that a deficiency will weaken your immune system there's absolutely no evidence that an excess does anything to \"boost\" it. The same idea applies to many \"immune boosters\" and the rest are generally just 100% untested snake oil. If you're not deficient in some way that it helps with, no marketing gimmick \"booster\" is going to make you more resistant."
],
"score": [
17,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0olgd
|
What makes a historically stable and successful company like Ford's stock historically worth 10-20 dollars with little variance while Tesla is chasing $1000 dollars?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjuncf4",
"gjuo4fn",
"gjunbky"
],
"text": [
"Firstly, stock prices cannot be compared. Apple's stock price is something like 400 dollars and Tesla's is chasing 1k, this doesn't mean that tesla as a whole is worth 2.5 times Apple. A share is a slice of a company, each company has this slice be different, Tesla's slice of the company is larger than Apple's for its share. That said, Tesla's market cap (overall worth of the company) is indeed a lot higher than Ford's. Stock price is based on the potential for future profit of the company. Investors believe a lot more in Tesla's potential for large profits than they do Ford.",
"First, it helps to remember that stock is basically a claim on a tiny fraction of the company's property. When you buy Ford stock, you're buying a tiny bit of the factories, marketing, tools and techniques, and all the other stuff Ford owns to produce its cars. The actual level of the price has a lot to do with the number of shares circulating and the size of the firm. A firm that has a ton of shares issued will have a lower share price than it would if it had issued a few shares. for this reason the share price is generally a bad guide to the valuation of a firm. You can look at total market capitilization (current share price times number of shares). This has its own problems, but is closer to the idea of the value of a company. By this metric. Ford has a market cap of $40 billion compared to Tesla's of $800 billion. This, despite the fact that Ford had a net income of $2.38B in Q3 2020 on $38 billion in revenue while Tesla had a net income of $0.3B in Q3 2020 on $8.75 billion in revenue. So what gives? Why does the market think Tesla is worth 20 times as much as Ford when Ford currently sells more cars more profitably? The answer is future earnings. People believe that Tesla is likely to make some big breakthrough and start delivering newer types of vehicles people really want at large scale and they'll take over a huge chunk of the vehicle market. People don't believe Ford will be innovative and grow to the same extent. Please do note, however, whenever you see this effect as extremely as you see it around Tesla right now it usually reflects a bubble. That is, people are only buying Tesla stock because they expect other people to buy Tesla stock, raising the price. Huge increases in market valuations like Tesla's in 2020 are almost always the result of a bubble.",
"Because Ford is known for stability, and not necessarily big innovation. Safe investments aren't the ones that make you rich, they just bring in a steady trickle. People know this, and so the stock price balances out accordingly. Tesla is constantly developing new shit, and is about on the cutting edge of auto innovation. There's a lot of risk, but a lot of potential for reward. People looking to make a lot of money want risk, because that's where the money is at. Higher demand commands a higher price."
],
"score": [
16,
9,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0oqcu
|
; Asked by my 7 year old; Could you Swim in Marbles?
|
Inspired by Scroge McDuck, of course. We were discussing how you could not swim in gold coins because they stack together and form into a more solid entity, and are not fluid like water. And then we were talking about ball pits and she asked if she had gold marbles in a swimming pool could she swim in those? I answered no originally but then realized, I don't know for sure.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjuoqoo",
"gjvy3pm",
"gjuntr8",
"gjv030x",
"gjvwozh"
],
"text": [
"The problem with gold specifically is the density. It’s eight times denser than glass and 19 times denser than water. You could probably work your way through glass marbles, but gold marbles will collectively weigh many thousands of pounds and you’d struggle to move them by hand at all.",
"Not answering your question specifically, but your daughter will probably find Mark Rober's video about [swimming in a hot tub of sand]( URL_0 ) absolutely fascinating! His videos are very child friendly and he explains the physics of what is going on really well.",
"Rather unlikely. Gold is pretty dense (19.33 g/cc ie 19 times that of water). So 1000 cc (1 liter) of gold would weigh 19 kg. A cup of gold would weigh approx 11 pounds. If you were submerged in gold marbles by even 1 feet, you'd probably have something like a ton of weight on your body.",
"The reason why you can move through a ball pit with relative ease is because the balls are hollow and generally extremely light and not dense. Gold is one of the most dense metals we have readily available. If you made them hallow enough to be able to easily move through them they'd likely crush when you touch them because it would be so thin and gold is a very soft metal.",
"If the marbles in an irregular pile, then you could, kind of. But imagine if you had a swimming pool that was, say, exactly 20000 marbles wide and exactly 100000 marbles long. In that case, marbles could settle into perfect rectangular sheets, all lined up just right, and those sheets would be absolutely rigid. You couldn't move a sheet like that unless you were strong enough to crush glass. So it matters a lot how organized the marbles are. If they're piled in every which way, they'd behave more like a fluid. If they formed a big \"crystal\" of neat vertical and horizontal rows, they'd be much more like a solid and diving into that would equal severe pain. It would also matter what kind of stroke you used. If you try to kick up and down in marbles, it would be extremely hard to move your legs down into a pile of marble and so not much would happen. But if you stroked across the surface, like a breaststroke, the marbles would have a much easier time flowing horizontally and you'd be able to push off against them."
],
"score": [
51,
12,
10,
10,
6
],
"text_urls": [
[],
[
"https://www.youtube.com/watch?v=My4RA5I0FKs&vl=es"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0owte
|
In business what is a trust? I’m reading about Teddy Roosevelt and don’t understand what a trust is or how it works?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjur6pk",
"gjuqsev",
"gjurhai",
"gjuqbdj"
],
"text": [
"In business, a trust is a legal entity where the assets and property of a business corporation are entrusted to an appointed trustee. The trustees will manage the operation and assets of the business, not for their own profit, but for the profit of the beneficiaries. In the context of Teddy Roosevelt’s use of the word, it was more of a term used at the time to describe extremely large businesses that had formed monopolies. There were business magnates like John D. Rockefeller who controlled something like 80% or 90% of the domestic oil industry, giving them almost unlimited power to control the market, set prices, and hold consumers and governments hostage. At the time, people referred to these giant monopolies as “trusts”.",
"Trusts are when several businesses in the same industry work together and do something nefarious. Price fixing would be an example. For instance, if every airline was losing money and the executives got together and said, “This free market competition stuff is harming us all. Let’s agree to not reduce prices for any ticket below $500.” So, a monopoly is if one company has total control. A Trust is if multiple companies act like a monopoly.",
"The trust in antitrust refers to a group of businesses that team up or form a monopoly in order to control how much things cost in the market.",
"Let's say I am the only company in the country that makes widgits. I have a monopoly on widgits can I can basically set the price to be whatever I want. I have a corner on the market and immense control. This is bad and so the government outlaws monopolies. I get broke up into multiple companies that now theoretically compete with each other. Competition drives innovation and results in better prices for the customer. But companies like the prices being high so rather than compete they both form an agreement to keep prices high. This is a trust and it is just as bad as a monopoly."
],
"score": [
19,
14,
12,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0p1d8
|
How does Carbon Dating work?
|
When I hear of Carbon Dating being used on an artifact, for instance. How do they (scientists) know?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjuq2cp",
"gjupguw"
],
"text": [
"When organic organisms are alive, they absorb naturally occurring Carbon 14 isotopes from the environment. Carbon 14 decays into Carbon 12 at a half life of 5,730 years. When an organic organism dies, it stops absorbing Carbon 14, however the Carbon 14 it has absorbed continues to decay. So by measuring the ratio of C14 to C12 in the specimen and knowing the half life decay rate, you can pretty accurately calculate how old the specimen is. This only works for organic materials, and cannot be used on metals or stone. So when dating an archeological site, the scientists have to find something organic, like a woven basket, to Carbon date.",
"It is thought (and evidence supports it) that two isotopes of carbon (C-12 and C-14) get locked into living things at a constant ratio. Once dead, this process stops. Over time, the C-14 undergoes radioactive decay to not be carbon anymore. This takes about 5000 years for half of it to go away. If you take a fossil with carbon remaining, you can use scientific instruments to measure the ratio of C-12 to C-14, and get an estimate of how long ago the thing died. It’s only good for things less than 50,000 years old. Older than that and there isn’t enough C-14 left to measure. Older than that and scientists use other elements to measure age."
],
"score": [
6,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0pfex
|
Why can't we just create a new liquid fuel to replace gasoline?
|
I'm a casual car fan and with all the news about electric cars coming i've always wondered why we dont just make a new fuel to take gasoline's place, also considering that ICE cars are pretty cheap and electrics are aiming for high prices it seems finding a way to repurpose the normal car would be a smart idea. since every chemical we make seems to be combustible to some degree anyway why hasnt this been looked into? is it because of environment issues or cost or something else?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjus0f3",
"gjus6mi",
"gjusp65"
],
"text": [
"Well, that's basically ethanol. The thing is that it's more efficient to just collect energy directly from the sun or wind and put it in a battery than it is to cover the planet in corn fields in order to make ethanol.",
"We can and we have. [Biodiesel]( URL_0 ), [Biomass to liquid]( URL_2 ) (BTL) and [Gas to liquid]( URL_1 ) (GTL) exist but the problem is the same as every other thing the uses energy and that's that big energy has a stake in those not taking off.",
"The only real good reason to do so is environmental impact or cost. Cost isn't a good reason though, gasoline is already the cheapest thing we can find because there is just so much of it in the ground. For environmental impact there is some case there though. Most of the chemicals we make that are combustible are hydrocarbons, molecules of hydrogen and carbon. The hydrogen isn't the problem here, burning hydrogen creates water. But anything carbon will create carbon dioxide. There is pure hydrogen, which is a valid fuel with some limited use out there, we do have hydrogen cell cars. But hydrogen has its own problems, while hydrogen on earth is plentiful, its mostly in the form of water, which we need energy to convert back to hydrogen gas. If we are burning fossil fuels to create the electricity to split water into hydrogen, might as well just use the fossil fuels directly in the engine, its more efficient anyways."
],
"score": [
8,
7,
4
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Biodiesel",
"https://en.wikipedia.org/wiki/Gas_to_liquids",
"https://en.wikipedia.org/wiki/Biomass_to_liquid"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0pk0l
|
Why doesn't gold corrode?
|
Mostly I'm asking, what about gold makes it so it can't react with oxygen?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"The atomic structure of gold just makes it non-reactive. Gold's electron configuration is 5d106s1. To try an simplify the chemistry a bit: - The 5d orbital is full - it has all 10 electrons it wants. This makes it difficult to have any of these electrons to engage in bonding. - The 6s orbital has a single electron, which _normally_ would make it reactive, but that electron is moving so fast around its orbit that relativistic forces are starting to come into play - the electron is _heavier_ because of how fast it is going, which means it moves closer to the nucleus of the atom. This heavy electron' position makes it very difficult for it to bond with other atoms. This combination of factors makes gold particularly non-reactive."
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"url"
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[
"url"
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l0pl31
|
Why can people administer self injections for some things (like hormones for egg donation) but not other things (like cortisone shots for acne) ?
|
Biology
|
explainlikeimfive
|
{
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"gjv7jti"
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"text": [
"Most self-injections are subcutaneous (SQ). SQ injections are pretty simple to administer with little instruction and it’s relatively hard to bungle it up. Some people are prescribed intramuscular (IM) injections, but it does take more instruction and there are greater risks involved (hitting vessels/nerves, wrong site, not in the muscle tissue, etc). So these are not something you see very often as “take home” meds. They’re generally more painful to get as well, and so many patients simply will not give them to themselves, or will make a mistake due to the pain/anxiety. But if it’s an SQ med that needs to be administered regularly and often, it’s far simpler and cost effective to teach a patient to do these themselves. It’s not that there aren’t risks with SQ, but as long as you follow some simple instructions and are paying attention you generally will have success."
],
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|
[
"url"
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[
"url"
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|
l0pmls
|
How did our eyes ever think 240p was crystal clear?
|
I tried to watch an old skate video from 2007 on YouTube and it was only available in 240p which obviously looked terrible. But once apon a time 240/360/720p resolutions were as crispy to us as 4k is today. What's the trick behind this?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Keep in mind that you are viewing these videos on a much higher resolution device. If you view a 240p video on an 4k monitor, without zooming it, it'll be like 1/10th the size of the screen. If you view the same video on an SD TV it'll take up much more of the screen without having ot stretch. When you stretch it to say 720p \"size\"... It's going to look way way worse.",
"You pretty much answered your own question almost. If it's the only thing to exist why wouldn't it look amazing back then? Just like how N64 games or PS games looked amazing back in the day. You'll probably look at something from now ten years from now and it will also be shit in comparison.",
"Your brain does an excellent job of filtering information. Low resolution video is similar to watching a black and white movie. You notice it at first, but once you start focusing on the story, characters, action, etc. your brain just focuses on the data, not the bandwidth. Also, back in the day, you likely weren't looking at 240p videos on a 4k flat screen monitor that's optimized for high resolution content."
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|
[
"url"
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[
"url"
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l0py2z
|
Is the amount of water on earth always the same?
|
Seeing as so many things are made up of water; and how it's always going through the same cycle. Is and has the amount of water on earth always been the same? Or is there water that somehow gets to earth from space or something? Also, are we basically drinking the same water the dinosaurs once drank?
|
Earth Science
|
explainlikeimfive
|
{
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],
"text": [
"Essentially, yes. With very little exception, the water we drink is the same water that dinosaurs drank and urinated, and likely thousands on people and animals in-between.",
"No. The total amount of water changes. The only way for water we have to disappear is to chemically split it back to hydrogen and oxygen, which plants do constantly via photosynthesis, and some loss to space from the top of the atmosphere. Weighing against that, we're constantly turning buried hydrogen into water (by burning fossil fuels). That was originally water that plants turned into hydrocarbons a long time ago, so there used to be more water than there is and we're slowly catching back up. There's also a small but steady rain of ice particles (basically very tiny comets) from space. Relative to the total volume of water, these are pretty small though, so virtually all the water we interact with has been around since long before there was life on earth.",
"For the most part, but water molecules can be split in to oxygen and oxygen, and can be reformed back in to water from those so it can change somewhat."
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5,
3
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[
"url"
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[
"url"
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l0q82z
|
what propels light? why is light always moving?
|
i’m in a physics rabbit hole, doing too many problems and now i’m wondering, how is light moving? why? edit: thanks for all the replies! this stuff is fascinating to learn and think about
|
Physics
|
explainlikeimfive
|
{
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"**This is *very much* an ELI5 explanation to lay out the basic concepts. As with a lot of things at this stage, the actual mechanics of it are... *complex*.** Light is always moving because *everything* is always moving -- or would be, if it had its way. The default speed of the universe is the speed of light. If there's nothing to slow you down, there you are, bopping around at *c*. So... why are *you* not moving at the speed of light? Well, it's because of your interaction with *other stuff*. If you have a particle that interacts with something called the Higgs field, it has *mass*. This mass has a lot of cool properties -- being able to touch it is a very popular one -- but another is that it requires more energy to get you moving. That makes sense, right? You need to push a dump truck a lot harder to get it moving than you need to push a bike; heavier (or 'more massive', with a couple of ELI5 fiddly bits) things require more energy to move faster. If you have *any* mass, though, it's impossible to get enough energy in you to get you to the speed of light. You'd need an infinite amount, and that's just not going to happen. The only things that can move at that speed are things that are already going at that speed -- and that don't have any interaction with the Higgs field at all. A photon is a massless particle. It doesn't interact in a meaningful way with the Higgs field (in a vacuum, at least), which is what gives mass-having particles their mass, so there's nothing to slow it down. It just runs at its own speed, which is the speed that everything in the universe would run if it didn't have anything getting in the way. #Extra Credit/Follow Up Questions/Pedantry Corner: **Why do massless things move at the speed of light in the first place?** You've kind of got the question backwards there. It's not that massless things move at the speed of light; it's that we call things that move at the speed of light 'massless'. That's how we define what 'massless' means. If you think back to Bill Nye and 'inertia is a property of matter', that's what we're talking about. (Inertia is the property by which something will either stay at rest or stay in uniform motion in a straight line, unless that state is changed by an external force.) Inertia is something that only things with mass have. **Why does gravitational lensing happen?/Why are massless particles unable to escape from a black hole?/How is a massless particle affected by gravity?** If photons are massless, how are they affected by the gravity of large and dense objects like planets or black holes? Well... they're not. Not exactly, anyway. You've probably seen the physics demonstration of spacetime, where [a large elastic sheet is weighed down by a heavy object]( URL_0 ), and items rolled across it in a straight line seem to curve their paths. It's not that the items are being rolled differently, but the fabric of 'spacetime' is being warped, so what *looks* like it should be a straight line is now curved. Black holes warp the spacetime around them so much that nothing can get out, including light; the mass of the photon (or not) doesn't make a difference. **The Higgs field only accounts for a small percentage of mass in the universe...** Yes, technically; only a very small percentage of mass comes directly from interaction with the Higgs field, including the mass of subatomic particles called *quarks*. The rest of it comes from what happens when you cram together a HUGE amount of energy into the tiny space of a proton or neutron, held together by the Strong Nuclear Force. (If you remember Einstein's equation of mass-energy equivalence, E=mc², what that basically means is that you can convert a tiny amount of matter into an enormous amount of energy, and vice versa. This is the principle by which nuclear fission occurs; when you 'split' an atom, that energy is no longer held in place as matter and just goes everywhere.) The three quarks inside every proton and neutron are held together by a buttload of energy, which 'becomes' matter due to mass-energy equivalence. Even though the energy *itself* doesn't interact with the Higgs field -- as I understand it, anyway -- the quarks do. If not for the Higgs field, you wouldn't have quarks; if you didn't have quarks, you wouldn't have the building blocks of matter as we know it today. If it helps, you can think of it as just an extra step. (And remember, this is ELI5; there's only so much detail you can go into before it becomes impenetrable.) **It's the speed of causality, not the speed of light...** Sure, technically -- they're the same thing, and things like gravitational waves also travel at that speed -- but 'the speed of light' is much more likely to be something your average Joe has heard of. (Again, this is ELI5; it's about explaining things to people who don't have a background in this sort of thing.) 'The speed of causality' is probably a more accurate description, and if it helps your understanding, go for it, but [if 'speed of light' is good enough for Wikipedia]( URL_1 ), it's good enough for me.",
"Think of light like Goku. Goku wears weighted clothes. Those clothes give him mass. When he takes off the clothes, he goes faster. Light is the same way, but it took off every bit of mass, which makes it move at the fastest possible speed. So the \"speed of light\" isn't just the speed of light, but the fastest anything can possibly move in the universe without breaking fundamental physical laws. The reason we will never reach the speed of light is because we have mass.",
"It's a fallout of how electromagnitism works. A changing electric field causes a magnetic field, a changing magnetic field causes an electric field. Given that light is wiggling electric and magnetic fields, it can't not move. It's like asking why a water wave is always moving...you can't stop a wave, it's not stable in one position because it's a dynamic phenomenon that's driven by it's own change. It's only stable if it moves.",
"It helps if you think of light less like a stone that's been thrown and more like a ripple through water. So the sun, and other light sources, are just making ripples all the time. And the thing they're making ripples in is usually just the vacuum of space. There's nothing there. So there's nothing to slow down the ripple, or make it bounce around. It just goes and goes until it hits something. Something like our atmosphere. So light hits our atmosphere, and it bends a little. So the sky looks blue because more blue light bends than other colors. Maybe the light hits you and bounces off. The place where you blocked the light is now a shadow, and the light that bounced off of you lets other people see you. No light; nothing to see. Lots of light; easy to see. Some things also absorb light. They just soak up the energy. That can make them warm like how the sun heats up the sidewalk, or it can turn into energy to grow, like how plants use sunlight. A combination of bounced light and absorbed light is what makes everything you see. That absorbed light could also be called \"stopped\" light. The energy is gone, and the ripple vanishes.",
"Does a photon emitted by an energized atom of matter INSTANTLY leave at the speed of light, effectively instantly accelerating? Was it \"always at C from birth\"? Or is there a near-instantaneous \"ramp up\" of the photon to speed?",
"You might as well ask ‘what is light’ at the same time. It doesn’t really have a ‘propulsive’ force. Once emitted, it moves at the speed it does unless slowed down by a medium. But once the medium’s gone, it goes back to its normal speed. Kinda like a wave in that sense. But it also has momentum and other things that make it seem like a particle; but you can’t have a particle just passing through solid objects indefinitely. Light is weird stuff that we don’t really understand why; we just understand that it is the way it is.",
"From a photon's perspective - there is no sense of motion, because there is no time - as your experience of time relative to the rest of the Universe slows as you approach the speed of light. So traveling at the speed of light - the photon exists at all points simultaneously - with no sense of past, present, or future.",
"More importantly, when a photon flies into your mouth, are you eating it?",
"Simplified explanation: An object's velocity when energy is imparted upon it is determined by dividing the amount of energy by the object's mass. Therefore, an object with a mass of 10 being propelled by an energy of 5 will move faster than if it were propelled by an energy of 2. Light has no mass, thus when it is emitted, *any* amount of energy will immediately accelerate it to the \"speed of light\" or *c.* This is the closest thing to dividing by zero in real life, because you'd be dividing the mass of light (0) by the energy imparted. ------ Added tidbit: The speed of light isn't *technically* the \"speed of light.\" That speed (300,000km/s) is the speed of causality. In other words, it is the rate at which change can propagate through the universe. The reason light hits that speed and then stops is because that's literally as fast as anything can traverse spacetime in our universe. You could think of it as the \"refresh rate\" of the universe.",
"This is just me as a layperson trying to figure it out a bit myself, but it seems that a photon begins traveling in the first place because it is emitted from some source, and does so with nothing to stop it until it is absorbed somewhere, by its interaction with other particles. Traveling with its full value of C in the spatial rather than temporal it experiences no time, and also has no mass, so perhaps even when reflected off of an object it never loses its energy until absorbed. Again, I’m not a physicist, but I love to learn about it try to visualize it.",
"To tack onto this, if light doesn’t experience time (unless absorbed or slowed by a medium) does that mean there are still photons out there emitted from the Big Bang?",
"It doesn't weigh anything, it has no mass, but it has energy, so by default it goes as fast as possible. The fastest anything can go is 3×10^8. That's why we call it the speed of light.",
"Light is an electro-magnetic wave i.e. it is made up of an electric field ( like around a wire with an electric current in it ) and a magnetic field ( like around a magnet with a magnet in it ). When an electric field collapses it generates a magnetic field and when a magnetic field collapses it generates an electric field. So a photon, or light, is a self propelling electro-magnetic field that oscillates between an electric field and a magnetic field. Einstein calculated how fast such a field would travel and calculated the speed of light.",
"Watch v-sauce's video \"what is the speed of dark\". That will help you go further down the rabbit hole.",
"I took up to physics 3 in college touching on relatively a bit and found it difficult to get conceptualize, but thinking about it this way blows my mind. If we were on earth and could somehow watch a live video feed of a person on a spaceship traveling at 0.5c, would their actions appear to us to be moving at half speed? Also, what happens when a photon moving at the speed of light impacts a surface? I know that it will either be absorbed or reflected but what is physically happening when the photon is absorbed and converted to heat",
"Okay, help me out here. If I run an electric current through a tungsten wire, thimgs happen. A photon hits my eye seemingly instantly. How does that photon accelerate to c as it spits out of the tungsten wire? Does it accelerate first or justs takes off at c?",
"The energy that produces light is what propels it. In the same way that the energy exerted in hitting a gong contributes in propelling sound waves.",
"During a lecture on human anatomy a student asked me, “do shits push the farts out or do farts push the shit out” with a completely straight face.",
"So, a few things. 1. Light is a wave. It is the protection of every in space-time as electromagnetic radiation. You cannot really stop a wave. We say it is like a partial because an interaction with light is nearly instantaneous an contains energy. 2. Light is \"technically\" not always moving and we even have the ability to stop light in certain materials."
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[
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[
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l0rlk4
|
why can you sometimes not remember a word or a name, but you recognise it as soon as you see it?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjvaedf"
],
"text": [
"Not at all an expert, but I'd imagine it's to do with the way our brains store information. Good at retaining, but not so good at regurgitating at will. For example: you could not hope to list every single movie you've watched, or books you've read. *But,* if you had a huge list of movies and books, you would very easily be able to tick off those you'd watched or read. The information is in there, but prompts always massively help our ability to recall."
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5
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|
[
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[
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|
l0sgr3
|
How is structural color different from other color, like the color from pigments?
|
I get that pigments involve absorption and structural color doesn't, but aren't they both ultimately based on the reflection of light? Don't pigments still reflect the light they don't absorb?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjvc0hj"
],
"text": [
"You are correct about pigments. They absorb some light and reflect other light. The reflected light is what determines the color you see. Structural light is a bit complicated, but I'll try to explain. Light can interact with itself, which we call \"interference\". Imagine two sine waves drawn on top of each other. If the peaks and valleys line up exactly, we call this constructive interference, and the light \"adds\". If you shift one wave over though so that the peaks of one match the valleys of the other, we call this destructive interference. It's destructive because the highs and lows \"cancel out\", and you get zero light. Now imagine another situation where you have two mirrors parallel to each other. The first mirror is half mirrored, so it reflects half the back. The second reflects 100% of the light. Now if you shine a light on these mirrors, some will get immediately reflected, and some will pass through the first and bounce off the second. Now you have the light interfering with itself. You can see how if you adjust the wavelength of the light, you'll adjust how the light lines up with itself, so you can get constructive or destructive interference. Some wavelengths will destructively interfere, and you won't see that light. This is how structural color works. The *structure\" of the reflective surface determines the color that you see. The color of the underlying material isn't the color that you see. Instead, color is controlled by bouncing light in specific ways."
],
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|
[
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[
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l0t9sy
|
Why do different currencies have different values? Why is USD worth more than AUD, for example?
|
Economics
|
explainlikeimfive
|
{
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"text": [
"Country one makes $10. Country two makes $10. $1 from country one is worth the same as $1 from country 2. Country one makes $10 more. Now, $1 from country two is worth $2 from country 2. That's one way. It also has to do with the stability of a country. If country one goes through a war, you can't really be sure that their dollar can really buy anything if there's nothing in country one to buy. There's also the idea that even though country two dollars are worth a lot now, you may not be sure how much it's worth tomorrow. If country two looks like they might be going through political turmoil or war or famine, you probably want to get rid of your country two dollars. Since no one wants them, they become cheap. Conversely, if country 2 just figured out alchemy, you probably want their dollars.",
"Currencies are basically goods in and of themselves. The same way you say that you'd be willing to pay US$3 for a sandwich, people would say that they'd be willing to exchange 1USD for 7.8HKD or vice versa. The valuation of one currency in terms of another is similar to the way stocks are valued; the \"lowest\" open offer or the last completed transaction sets the price. So there's basically a huge set of standing offers for each currency with respect to any other currency that establishes the exchange rates."
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|
[
"url"
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[
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|
l0tj24
|
How does google give you a free google drive account for every email address? Can't someone just make hundreds of free google drives?
|
Other
|
explainlikeimfive
|
{
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"gjvhp0t"
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"text": [
"Yes. Yes they can. But they'd each only be 15GB. Which, frankly if you need to store > > than 15GB of data but can't afford $100/year for 2TB, you'd just run out and buy a $60 2TB external drive. Unless you're some kind of google profile _masochist_ and wouldn mind switching constantly between a dozen 15GB free accounts. That would be like keeping your bank account but spread over a dozen accounts that could hold max $100 in each one. The first time you needed to $765 to pay for a car repair you'd spend half an hour with a dozen debit cards at the ATM to withdraw it. You pay for the convenience of having a single sign-on with adequate storage for everything. Yeah you can do it with free accounts but its a pain in the ass. If you could write a desktop gdrive app that could _span_ multiple gdrive _accounts_ that _doesn't_ violate the ToS, and price it reasonably, you'd be a wealthy developer my dude. The instant someone figures out how to do this, they'll slap 3 factor prismatic Smurf authentication or something else to break it for us average users and then we're all in a world of hurt."
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10
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|
[
"url"
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[
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|
l0tp4m
|
why the Chinese government is targeting Uyghur Muslims?🤔
|
Other
|
explainlikeimfive
|
{
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"gjvi95e",
"gjvib7m"
],
"text": [
"Their reasoning is that they have been known to be terroristic, there was something about a bombing at some point. When I debated with someone from China in reddit they claimed the attack was like white nationalists attacking the White House everyday.... I feel like that's a bit of a stretch, but the idea is that they are a threat to the people. Edit: and I'm not saying they are or aren't a threat, I'm just parroting some people's opinions over there.",
"Because they don't put China or the Chinese government first. Same reason they persecute Christians that don't toe the party line, and anyone else for that matter. Wouldn't want people getting ideas, and thinking they want something other than they are told to want."
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3
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[
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[
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|
l0uzfd
|
How does bone marrow transplant work?
|
Biology
|
explainlikeimfive
|
{
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],
"text": [
"The bone marrow is an organ which does not have anything directly to do with the bones except that it is located throughout your bones. Instead it is an organ that is mostly related with regulating your blood. So most of the cells that make up your bloodstream is created in the bone marrow. There are some diseases such as certain forms of cancer which may require you to be treated with a bone marrow transplant. In some ways this is similar to transplanting other organs such as liver and kidney except that it is not possible to surgically remove the bone marrow. So the procedure starts with giving the patient drugs and other therapy that will kill all or at least most of the cells that make up the bone marrow. This will hopefully kill all the cancer cells as well. However without a constant transfusion of blood they will die as they can not make new blood without a healthy bone marrow. So healthy bone marrow is collected from a healthy individual. There are two ways to do this. You can either go inn directly with needles that can penetrate the bone and extract the bone marrow. Or you can administer drugs which cause cells from the bone marrow to enter the blood stream where it can be collected and filtered through a standard procedure similar to blood donation. This healthy bone marrow can then be injected into the patients blood stream and will find its way to the bones where it will replace the previous bone marrow. It is one of the easiest organs to donate. It just involves two very simple procedures not requiring more then a single needle each. There are very few side effects and is one of the few organ donations where the donor is expected to make a quick and full recovery. You can easily save a life in your lunch break. Most places that allow you to donate blood also allow you to register for bone marrow donation."
],
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|
[
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[
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|
l0v70v
|
why do we never remember falling asleep?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjw78l5",
"gjwxj2u"
],
"text": [
"Occasionally I can't fall asleep without being aware of the whole thing. On normal nights I watch random objects and people appear in my mind just as I drift off. On bad nights I have a 5 second long terrifying nightmare and spontaneously wake up 4 hrs later. It's like imagining a story or a place you were and it gradually becomes a dream your in.",
"The cursor in your head is hijacked by another dimension -where they debug your software while you regress to your mamillian dreaming state of peculiar chaos. What else could it be?.?"
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3
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[
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[
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|
l0vmnc
|
When seeing how old a spear/ arrow head is how do they know the age of when it was carved/made and not how old the rock itself is?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Usually they can find other materials that are buried at the same level that they can to date by measuring decomposition of isotopes in carbon",
"Most fossils and tools are found at certain levels in the ground. This is a good starting point for age verification but it’s never 100% perfect which is why we say “dated to be between X age and Z age”",
"There is a saying in archaeology: If it is outside of a context, it is worthless. So yes, more or less, it is difficult to date object itself, especially stone one... Sometimes you make an educated guess based on style or material, but in most cases you rely on context."
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|
[
"url"
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[
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|
l0vzi5
|
How countries make money through wars
|
Economics
|
explainlikeimfive
|
{
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],
"text": [
"Countries don’t make money off wars in the modern era. In the ancient world, capturing more land or people to enslave or tax might have benefited the core of the empire but (obviously) harmed the people who were conquered. But even in ancient times, peace, diplomacy, and trade were almost always more profitable than war."
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3
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|
[
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] |
[
"url"
] |
|
l0w0ld
|
Why can't magnets produce perpetual energy?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjw0xvq",
"gjvwvhd",
"gjw00ve",
"gjvw5nb"
],
"text": [
"For the same reason you can't use gravity to do it: whatever arrangement you try, it'll eventually come to equilibrium and the energy you use to restart it will be more than what it produces.",
"Magnets in and of themselves don't produce energy, they need to be passed through an electromagnetic field and the interaction is what produces the energy we use",
"A magnet can certainly pull things, but it's like a rock rolling down a hill. Once the \"pull\" happens, or in the analogy, once the rock has rolled down the hill, the potential and kinetic energy is gone. You can pull the magnets part, or roll the rock back up the hill, to reset the potential energy and roll it again! But you had too put energy back into the system by rolling the rock back up, or by pulling the magnet away from whatever you pulled towards the magnet.",
"Magnetism, when in employed in a electromechanical system, is subject to all physical forces that act on engines and whatnot and the energy is readily lost to friction and gravity."
],
"score": [
14,
10,
8,
7
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0w1v5
|
what is the 1776 report and why is everyone talking about it?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjvwq4n",
"gjvx7yc"
],
"text": [
"The New York Times did the '1619 Project' back in 2019. 1619 was the year the first African slaves arrived in America. The 1919 project was aimed at showing that African slavery was the most dominant part of the early history of the colonies. Many people felt that it was flawed. The 1776 Project was created specifically to refute the '1619 Project.' It attempts to downplay the slavery issue. Donald Trump was a foe of the 1619 project and is a fan of the 1776 one.",
"It’s a far right publication, with no historians signed on, that claims that Americans are being brainwashing by learning about racial justice. It’s basically a bunch of ahistorical propoganda similar to the rise of far-right Japanese publications denying their invasions of China and Korea in WWII. People are talking about it because someone might believe it (despite a lack of backing by actual experts) and the fact it’s formulated as a “rebuttal” to the famous 1619 Project, which was years of research by dozens of researchers on the impact of slavery on the founding of the Americas. Basically, it’s propoganda presented as a call to action against facts in the United States."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0wxna
|
If our phones can have such small cameras yet retain good image quality, why are security cameras so large yet have relatively bad image quality?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjw1l1d",
"gjw2812"
],
"text": [
"It just takes a massive amount of data to record all the time so they compromise resolution to keep storage manageable.",
"A number of factors like cost, it is too expensive to by a good quality camera or to pay for high quality storage. Storage doubles as the second factor in that storing HD footage takes significantly more space (and more money) this second reason is usually the main one that is they don’t store the video in HD One more and this isn’t backed up by real world knowledge but something to consider which is age of the camera. Most security cameras probably don’t get upgraded very often which could contribute."
],
"score": [
13,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0xlp2
|
How can something that doesn't have mass exists?
|
Read a post about the speed of light and saw that the photon is massless. I'm curious as to how it existed.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjw65wp"
],
"text": [
"Because things can exist that do not interact with the Higgs field, or gain mass from quantum vacuum fluctuations. More basically, there is nothing stopping them from existing, so they do. You could equally ask \"how do things *with* mass exist?\" And eventually get a \"because that's the way the universe works\" response."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0xmqw
|
how do thirst and hunger work?
|
I’m a nursing mom and always hungry and thirsty. As I was getting my 27758 glass of water today I realized I have no idea how this works.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjxq58u"
],
"text": [
"No idea about hunger but I can answer for thirst! So when levels of water in your body are low, this causes blood volume to be low too. It also means your blood has a higher proportion of proteins and cells etc to fluid than it did before. Now, you have these receptors called osmoreceptors in your body. Receptors can sense different things, like hormones etc. When the osmoreceptors detect this change in the blood, water leaves them and they shrink. This causes a signal to be sent from these receptors to a part of the body called the hypothalamus. This produces what's known as the thirst response - so basically telling you to increase your water intake. The thirst response can also be stimulated by other things - for example, receptors in the heart called baroreceptors can detect that blood volume has decreased. They DON'T send a signal to the hypothalamus, and this causes the same events to unfold as before. I hope that helped! Sorry if my explanation is a bit confusing or incomplete Source: First year medical student"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0xuzh
|
How do QAnon believers tell the difference between what's considered a genuine Q post and trolls?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjw7syq",
"gjw8q4m",
"gjw8iy4"
],
"text": [
"Same way you know which books of the Bible were accurately transmitted to reliable prophets. Obviously.",
"It's confirmation bias all the way down. If you agree with them, you're a reliable source. If you disagree, you're a deep state shill.",
"They can't really. In Germany was a couple of months ago, a conspiracy from a satire website that one prominent conspiracy person, Atilla Hildman (a vegan chef), was working for the government. And in the next day people were writing to him messages on telegram how he could betray them. They simply only trust things that tells them their opinion or another conspiracy."
],
"score": [
6,
5,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0y3j0
|
Why did we more widely adopt carrier grade NAT instead of IPv5?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjw99hi"
],
"text": [
"Well technically it's IPv6 that's been accepted onto the greater internet. There was an IPv5 created but it didn't take off, and the number has technically been claimed even if it is considered a failed project. But the problem is there's no backwards compatibility. If a program wasn't written to support IPv6, it won't run IPv6, period. Besides old software and video games and stuff, that potentially includes routers which may need a software (or hardware!?) upgrade. New DNS record types need to be added. Management and accounting by the ISP needs to be done for their whole network basically from scratch. It's a lot of work. Much of it has been done, but IPv6 just has so much momentum. CG NAT is the easier, if horrible and shorter term, solution."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0yvy2
|
How can you waste water if it just cycles from evaporation to precipitation? Wouldn't it just always be the same amount of water?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjwd9ql",
"gjwdctw"
],
"text": [
"It’s more of the cost it takes. The Water Bill in New York for example, is ridiculously high. So that’s what they mean.",
"I mean, go and drink from the ocean then...Oh yeah, that water isn't usable for drinking...And the ocean may be very far away... Water may not, generally, leave the Earth, but it tends not to occur in tremendous abundance in areas where we need it and also without other stuff in it."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0z0q2
|
How does “dry-aged” beef work and why does it not kill you to eat it?
|
For most foods, especially meat, the experts usually say you’re supposed to throw it out after about a week at most. So how can you ignore all that and stick a chunk of meat in your fridge for sometimes upwards of 60 days and it’s “fine dining?” And how does eating meat that old not at least give you food poisoning?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjweynk",
"gjwfved",
"gjwekcf",
"gjwjuv0"
],
"text": [
"Proper dry-aging is done in a temperature and humidity controlled environment. Moisture is drawn out of the meat to concentrate flavor. Simply leaving the meat out or in the fridge is different. According to URL_0 : \"The USDA notes that there are two types of bacteria: pathogenic bacteria and spoilage bacteria. Spoilage bacteria causes the food to start smelling and tasting funny, but consuming it won't harm you. Pathogenic bacteria, on the other hand, is harmful bacteria that doesn't affect the taste or smell of the food in any way but can cause you to fall sick.\" Pathogenic bacteria, including E. Coli, salmonella, listeria, and others, thrive in warm, humid environments, which are prevented (along with spoilage bacteria) by the temperature and humidity controlled environment in which meat is dry-aged.",
"There's a key difference between beef and meats like chicken that makes this possible: the bacteria that attack beef pretty much all stay on the surface. This is why you can eat rare steak but not rare chicken, and it's also what makes dry-aging viable. Since all of the dangerous parts are on the outside, you can just cut that off after it's done aging and still have an edible piece of meat. This is also part of why dry-aged beef is as expensive as it is. Part of that is simply the time and storage space it takes up, but you also lose a significant portion of the beef in the process.",
"All the bacteria and other bugs that would do this to you need moisture to grow. Dry-aging and salting remove that moisture, which allows it to stay good much longer than unpreserved meat because the bacteria can't live in the environment. To give you an idea of how much salt we're talking about, salted meat would typically be boiled when preparing to make the salt bearable and soften the meat, which would be full of crystallized salt at that point",
"Stuff that makes you sick likes warm, wet and non-salty environment. The dry aging is a controlled environment that removes moisture, the outside of the meat forms almost a crust or scab. There may be some bad stuff there but it can't get inside the meat, and the outside is trimmed off before cooking."
],
"score": [
16,
14,
7,
3
],
"text_urls": [
[
"Livestrong.com"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0z4wp
|
Why are crocodile and alligator snouts different shapes? Do they serve different purposes?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjwgrlv"
],
"text": [
"Alligators jaws are broader, due to a larger portion of their diet consisting of turtle as compared to crocodiles which largely eat fish. Of course there is overlap, but from a very general point of view, that’s why."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0z6ph
|
Why on some days the sunset is very and orange-y and pretty whereas on most days it is just a slightly dimmed version of the usual daylight colours until the sun disappears? What factors make a really pretty sunset?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjwfhzu",
"gjwg6yn",
"gjwfggg",
"gjwt0tv"
],
"text": [
"I'm pretty sure it isn't the only phenomena that causes changes in sunset colors, but air pollutants from a variety of sources interacting with the light rays can contribute to such color changes. One particular example that comes to mind are sulfur dioxide aerosols emitted from volcanic eruptions.",
"Humidity, what type of clouds, fog. Temperature sometimes.. elevation... all sorts of factors.",
"If I recall correctly it has to due with how much dirt and dust is in the air. The more dirt and dust the darker the color. This will often coincide with weather changes such as wind and rain.",
"Well.. the more \"stuff\" to reflect off of usually leads to a more appealing sunrise/ sunset. Different clouds will give different looks. Usually right after a storm, before a sunset, it will look amazing because of the high amounts of humidity and cloud cover from the storm. However if there are no gaps in the clouds, it will just go dark without anything to look at."
],
"score": [
6,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l0z7zf
|
Why is laying in bed not being able to fall asleep so incredibly less resting than actually sleeping?
|
I mean as I am laying awake at 3am I come to think about this. Im in my bed still. And im not doing anything. Im technically super relaxed. Empty mind.. why will I still be extremely tired at work tomorrow compared to when I get my 7hrs of sleep? Whats the extreme difference between laying awake not doing anything and actually sleeping when it comes to body rest?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjwffcz"
],
"text": [
"When you sleep your body is doing something completely different than being awake, specifically your brain. Your brain releases chemicals that completely paralyze you, it sorts memory’s and so much that’s vital to feeling awake. Another thing your body does is repair itself, muscles, skin, any kind of wound you may have sustained the healing process increases a lot while sleeping."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0z9qh
|
Why fresh fallen snow seems like there are silver flakes mixed in and they're shining?
|
Just a little question that I came up with while I was walking home.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjwgmpe"
],
"text": [
"Snow is little bits of ice. Ice is frozen water. Water reflects and refracts light. The crystals of ice that make the snow cause the light to reflect off their various surfaces."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
l0za2t
|
Why is it that when you scratch metal on metal, it produces a terrible screeching sound, but when you scratch another material on metal (ie. wood or plastic), it doesn't?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjwhdtw",
"gjwg59u"
],
"text": [
"Taking a stab in the dark and going with hardness. Plastic and wood seems hard to us because we’re squishy. But compared to metal they’re soft.",
"Not exactly sure, but metals are arranged in very orderly rows called a lattice. Versus other solid materials like a chunk of coal or piece of wood. I would think the orderly metal carries sound much better than amorphous solids. Sound would actually move about 12000 in a diamond vs 350 in air. Again, not sure 🤷♀️ just my best guess."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l10048
|
Mechanically, what is happening in your body to give you a stiff neck on one side after sleeping in a bad position?
|
Every so often I will wake up like this. Why is it that when I turn or tilt my head to one side, I feel like I can't move it and I experience a lot of pain? Is something getting in the way or is it just muscle that doesn't want to move anymore?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjwoj08",
"gjy5gpz"
],
"text": [
"Sleeping in a bad position can physically strain either muscles or other soft tissue in your neck, causing microscopic damage which in turn causes inflammation which in turn puts pressure on nerves and causes pain. This is working as intended as your body is signalling you to not cause further damage by moving your neck in certain ways while its busy with the repairs. A latex rubber band serves as a good analogy - stretch it out and keep it stretched for a long period of time, once released from the stretching it is unable to return to its original length because even though nothing visible has happened to it, there is microscopic damage - you sprained your rubber band! Fortunately our bodies are very good at dealing with light tissue damage like that, it is in fact used as a catalyst for growth in some cases and no cause for concern. Eating a varied diet with lots of nutrients and keeping active physically make your body more flexible and thus more resistant to this kind of damage.",
"Since ive seen other people explain it here, ill just offer up my experience. Get a new pillow. Experiment with which height/softness feels best if you can. I used a regular cheap pillow most of my life and it was ok. Then I was gifted a bamboo pillow and I started having consistent neck problems after sleeping. I switched to a flat gel pillow and I have been neck pain free for quite some time now."
],
"score": [
205,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l108uz
|
If heat causes things to expand (like metal), why do clothes shrink in the dryer?
|
My shirts no longer fit me, whoops! Thanks in advance for your responses.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjwnd9w",
"gjwn6ma"
],
"text": [
"Materials do generally expand with heat but in case of clothes in a dryer, this type of expansion is negligible, for a piece of cloth 1 meter long, the difference would be less than a millimeter. Instead what you're witnessing is poor manufacturing techniques. Manufacturing fabric tends to stretch out the individual fibers and heating (especially after washing) said fibers releases the tension, causing the clothes to shrink. Better quality clothes go through a wash/dry process in the factory and suffer less from this issue but it takes quite a few washes to get all of the tension out so some shrinkage will likely still occur.",
"Basically when exposed to heat, and tossed around in a hot environment, the tiny, wet fibers that make up the shirt constrict a little. Even though they don’t constrict much, all of them constricting together make the shirt shrink up."
],
"score": [
10,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l11t0v
|
If you have sprained knee and you take a Tylenol (or any other brand) to help relieve the pain, how does the medicine in the pill know where to go and what to target? Or is the medicine just a disbursement throughout the entire body?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjwva39"
],
"text": [
"The latter. The medicine disperses and blocks pain receptors across the body from saying you feel pain. If you had a headache and sprained knee both would lessen."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l120zl
|
Does a photon experience time as we perceive it?
|
If a photon travelled a billion light years to come to Earth, how do those billion years pass from the photon's perspective?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjwx5tm",
"gjwx67n",
"gjwzzn9"
],
"text": [
"That time passes instantly for the photon. The moment it is emitted, and the moment it is absorbed, are a single moment when considered from the photon's reference frame. In effect, photons don't experience time at all.",
"No, photons do not experience time at all. The closer you go to light speed the \"slower\" time moves at light speed time stops. From a photons perspective all things are instantaneous. The photons leaves the star 2 billion light years away and hits your eye at the same instant. The star and your eye are also infinity close together from the perspective of the photon. TL;RD relativity is a hell of a drug",
"A photon _does not have_ a perspective. Answers to questions like this rely on the introduction of a \"co-moving inertial reference frame\", which is a mathematical transformation to a frame of reference where the observer is stationary. It's a core principle of relativity that we can predict the result of observations made from any inertial reference frame using measurements made in any other inertial reference frame. That's how we can make statements about observations from another observer's \"perspective\": by mathematically transforming our measurements into the co-moving inertial reference frame of the other observer. But the other core principal of relativity is that the speed of light is constant in _all_ inertial reference frames. That means there is _no_ frame of reference where light is stationary, and _no_ principal we can use to make predictions about observations \"from the photon's perspective\"."
],
"score": [
9,
9,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l12km3
|
How does government spending and accommodative monetary policy supposedly lower unemployment?
|
I know that in economic models it’s easy to explain, but in real life how does it work? How do buying bonds and lowering interest rates actually cause more people to have jobs? What is the chain reaction?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjx286u",
"gjx2k9b"
],
"text": [
"By lowering interest rates, we make it cheaper for companies to borrow. The cheaper it is for a company to borrow, the more investing (via borrowing, buying hardware, hiring people, and paying back the debt in the long term) the company can do, and the more widgets the company can make and sell. Cheap *short-term* borrowing is really important for big businesses, because it’s usually easier and cheaper to borrow overnight than to keep oodles of cash lying around. Ask me about the 2008 recession and GE Credit if you want a horror story. Again, cheaper loans = more investment = more jobs. Meanwhile, if I want to buy a house or a car, it’s cheaper for me when interest rates are lower. The cheaper it is for me to borrow money, the more likely I am to buy a car/house. This also applies to credit card purchases of luxury goods (laptops, TVs, etc.). In turn, when I buy lore stuff, I increase demand for stuff, and that causes suppliers to increase output or allow the price to rise (more profits, in theory). I’m not sure about bonds.",
"It is not really about bonds and interest rates as much as it is about the increased circulation of money. See, one of the things that happens when economies dip is that people stop spending as much money. They pinch pennies. This reduction of the money supply can have a negative feedback loop where the economy dips so people pinch pennies, which causes the economy to dip some more which cause more people to pinch, etc etc etc. By lowering interest rates and such, what you've done is essentially have a clearance sale, except the clearance sale is the whole country. And poor or not, people love a clearance sale! **And this is the key to the whole process**: keeping people spending money means that sources of production (stores, services, etc) keep doing steady business. And if they are doing business, they need workers. And if workers are employed, then they are making money, *and then they go forth and spend that money*, and the whole circle of life keeps spinning. For a counter example, let's look at austerity measures and why it is so god damn fucking stupid to implement in a recessive n (fine during a boom). Seriously, it's fucking HORRIBLE in an economic recession. Why? For the opposite reason stimulus is good: it promotes money being taken out of circulation. Austerity contracts the money supply, and makes it more difficult for people to spend spend spend. And if no one buys, then no one produces. And if no one produces, there is no need to keep him or her employed. No jobs means even LESS spending, and the circle of life grinds to a halt. So to make it easy to remember, stimulus in a bad economy to speed it up, and austerity in a good economy to slow it down and keep a steady momentum. Hope that helps. Especially the next time you hear a politician speak.doea he or she say we have to cut spending when there is a recession? *Then do not vote for that fucking dipshit*. Likewise, do they enact stimulus when the economy is firing on all cylinders? Like how that fucking cocksucker Donald Trump slashed taxes in the middle of a boom when he should have been RAISING taxes to recoup revenue lost during the last recession that was also caused by Conservatives? Then don't vote for that asshole either."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
l12ncj
|
How do popular flouride/tooth sensitivity toothpastes & mouthwashes actually repair and treat tooth enamel when enamel is supposed to be irreparable?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjxi5g5",
"gjwzy2y",
"gjx6s4l",
"gjy5193"
],
"text": [
"Tooth enamel doesn't regrow, but it can be remineralized. That means minerals move into the enamel, making it harder and stronger. Enamel is made of a mineral crystal called hydroxyapatite. Inside your mouth there's a natural cycle of mineral loss and remineralization that happens every time you eat. Acidic foods and acids produced by bacteria growing in your mouth and on your teeth cause tooth enamel to lose minerals. Acids react chemically with the mineral structure of the enamel, basically dissolving it. Physical wear, such as from chewing or brushing, can also cause loss of minerals, especially when the inside of your mouth is acidic like it is right after eating. But once your mouth is clean, the saliva goes to work putting minerals back into the enamel. Saliva is not acidic, and it contains calcium and other ions needed to remineralize the enamel. It's basically growing a mineral crystal inside your mouth, much like how rock candy grows in a supersaturated solution of sugar. Each time you eat you lose minerals from your enamel, and then between meals, if your mouth is clean, the minerals are put back. But if you eat a lot of starchy, sugary, or acidic foods, or you brush your teeth too roughly, or you don't get your mouth clean enough after eating, the mineral loss will happen faster than the remineralization. This eventually leads to tooth sensitivity or cavities. Cavities can't be reversed by remineralization. When you have a cavity, the enamel is gone from a section of your tooth, so there's nothing to grow the mineral crystal onto. The food you eat contains starches and sugars, which are sticky. They stick to your teeth. Saliva breaks down starches into sugars. Bacteria eat the sugars and make acids. This all happens right on the surface of your teeth, where the acids are in a position to cause damage to the enamel. Bacteria also make a sticky film, a kind of scum that sticks really well to your teeth. It's called plaque, and you can brush it off. But if it isn't removed completely, over the course of several days, eventually the older bacteria die, and become mineralized by your saliva, in much the same way that your enamel is. But this mineralized old bacteria isn't smooth like the surface of your tooth. It's crusty and porous - the perfect place for new bacteria to live, hiding within that crust where your toothbrush can't reach. This mineral crust is called tartar or calculus, and it can't easily be brushed off. It's a little bit too hard for that. It needs to be scraped or polished off. Once tartar forms on your teeth, it's a vicious cycle: the tartar keeps getting thicker and crustier, all the while harboring more and more bacteria that produce more and more acid that cause more and more mineral loss in your teeth. That's why it's important to brush and floss soon after every meal. Brushing and flossing clean away the food and the bacterial plaque before too much acid can be produced and before the plaque has time to be mineralized into tartar. Just don't brush too hard, because that also causes wear in the enamel, at the exact time when it is most vulnerable (right after eating, when the bacteria are feeding and producing acid). You want gentle circular motions. Brushing too hard can also wear down your gums. Toothpaste contains cleaning agents (detergents) that help to wash away food and bacterial films, and mild abrasives that give a little extra cleaning power for the surfaces of your teeth. Flossing is important for the sake of your gums. Food stuck between your teeth and next to your gums is food for bacteria that make acids, and the acids are harmful to gum tissue. When you lose too much gum tissue, you'll eventually lose teeth. If you keep up with your flossing and brushing, for most people that will be enough to prevent gum disease and excessive loss of minerals from the tooth enamel. But some people are a bit lazy or need a bit of help, and that's what fluoride does. Without getting too technical, when there are fluoride ions in your mouth, it changes the remineralization process. The fluoride ions act in place of one of the other ions naturally found in saliva, causing a different mineral called fluorapatite to be formed during the remineralization process, instead of the normal enamel mineral, hydroxyapatite. Fluorapatite is less vulnerable to acids than hydroxyapatite, and so teeth remineralized with fluoride are actually less likely to develop cavities than teeth remineralized without fluoride. Remineralization also happens more quickly with fluoride than it would with just the ions found naturally in your saliva. But fluorapatite is not as strong or white as hydroxyapatite, and so you don't want to overdo it with the fluoride. When your teeth incorporate too much fluoride, it's called fluorosis. Most people who do a good job brushing and flossing frankly don't need any fluoride. But too many people aren't good at brushing and flossing or for whatever other reason are susceptible to cavities, and so as a public health measure, fluoride is put into toothpaste, some mouthwashes, and even in the municipal water where some people live. Fluoride is controversial. Some people say fluoride does more harm than good, or object to the idea of giving a drug to everyone even when they didn't ask for it. Toothpaste for tooth sensitivity has nothing to do with remineralization. Most toothpastes for sensitive teeth contain little bits of material that temporarily fill in some of the holes in your tooth's surface, blocking acids and other irritants from reaching the nerves inside your teeth. The effect is temporary. To really get a handle on tooth sensitivity you need to improve your basic oral hygiene, avoid the sugary and acidic foods that contribute to tooth sensitivity, and drink only water between meals. Of course, see a dentist if there are problems you can't solve on your own at home.",
"Basically because enamel itself cannot be repaired by the body, but the fluoride in toothpaste can form a different compound that can fill in the gaps in teeth. So it's filling in tooth enamel with a compound that isn't tooth enamel. It's not as strong, but as long as it fills in the lesion so that it can't progress to a cavity it's fine.",
"Just as alex said. It is really important to note though, \"repair\" is a really scummy term in this sense but it's technically true so the companies get away with it. Think of it like tape covering a hole. Enamel is duct tape, strong and usually enough to last a lifetime while the flouride is like clear/scotch tape where you have to keep re-applying it constantly.",
"I designed a WWTP (wastewater treatment plant) for GSK at a facility that made Sensodyne. We found out that brand of toothpaste contained microsilica which “plugged” the holes in your teeth. This is how the product works to help with sensitivity."
],
"score": [
37,
21,
6,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l13d6e
|
I Wonder What Other Cool Things My Dad Did...
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjx4csn"
],
"text": [
"I'm sorry but what did you need explained?"
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l13ry1
|
what "powers" magnets? how do magnets attract stuff, overcoming things like wind resistance, withiut creating energy?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjx90xu",
"gjx5zq1"
],
"text": [
"It's analogous to gravity. If you lift a weight, you're putting energy into the weight. We say that a weight that's been lifted high up has high potential energy. You let it go and it falls to the floor, releasing that potential energy and turning it into kinetic energy. You could likewise think of it in terms of work. You exert work on the weight by lifting it, and when you drop that weight it exerts work on the floor by leaving a dent or making a loud noise or whatever. Magnets do the same thing. You pull two magnets apart from each other and their potential energy increases. Let go and they speed towards each other, converting the stored potential energy into kinetic energy. The work you put in pulling them apart is turned into work by the magnets slamming into each other (or overcoming wind resistance as you pointed out). Whether you're lifting a weight or pulling magnets apart the total energy remains the same, it's just converted between various forms.",
"Electromagnetic force is one of the fundamental forces of the universe. Like gravity. Negative charges attract positive charges. This is the entire basis for magnets"
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
l14b4c
|
Why is it we often think a person looks like their name?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjxf9cu",
"gjxbbye"
],
"text": [
"Because names are arbitrary. My name is Thirteen, and everyone says I look like that fits me. Apples don't look like apples they are just a label we put onto it. There are very few things that have an inherent reason why they are called what they are called",
"It's history and association. If every man named tom looked like tom Cruz, someone who looks like tom Cruz that is not named tom would \"look like a tom\". It's just someone's own history of seeing people and knowing their names. This also applies to historical figures."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
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