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9ozrn3 | ny why do cars on the opposite side of a divided highway have to stop for a school bus flashing red lights? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ozrn3/eli5ny_why_do_cars_on_the_opposite_side_of_a/ | {
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"Your photo shows that opposite traffic must slow and prepare to stop.\n\nJuat curious, can you link to the actual law stating you must stop on a true divided?"
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lzxeq | eil5: why is hate speech not protected speech? | I get that hate speech is bad, but what makes it different from normal, protected speech? As far as I understand, in Snyder v Phelps, for example, the Supreme Court ruled that the Westboro Baptist Church could continue protesting because even though what they're doing is bad, it's still speech and is thus protected. So why is hate speech not given these same protections, and how is what the WBC does considered separate from hate speech? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/lzxeq/eil5_why_is_hate_speech_not_protected_speech/ | {
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"Hate speech *is* protected speech. ",
"Hate speech **is** given the same protections. Incitement of violence is not protected, but hate speech is definitely protected and thriving. Have you never seen _URL_0_?",
"The question is fallacious — hate speech *is* protected by the first amendment. I think you are confused because there is much attention paid to \"hate crimes\", e.g. burning a cross on somebody's lawn or vandalizing their house with swastikas. But in each of these \"hate crimes\" there is some underlying crime (usually violence or vandalism). Pure speech -- even controversial or hateful speech -- is still protected by the first amendment. In America, neo-Nazis can picket Jewish synagogues, the KKK can have a parade, as long as they do it in a law-abiding fashion This is an unalienable right of man and I love all nations that protect this right. ",
"It is difficult to define, but I think it is safe to say that invading someone's dreams and turning them into a staggering monster is not a form of protected speech.",
"Unlike in the US, hate speech is not protected in many countries due to the fallacious assumption that speech itself is dangerous.",
"Relatedly (and where I think your real confusion is coming from) a lot of speech is considered protected, but can be regulated to an extent by the government. When government wishes to regulate protected speech in a content specific way (as opposed to content neutral like saying you can't protest in X location, or you can't protest with signs bigger than Y by Z), they must pass a [\"strict scrutiny\"](_URL_0_) test. This means that the government must have a compelling interest; the law must be narrowly tailored to achieve that interest; and it must be the least restrictive means to achieve that goal. Generally when this test is applied, it means a law is going to be struck down, but there are some situations where the law can succeed under this test.\n\nSide note: that strict scrutiny test is used any time a fundamental right seems to be infringed by a law or when it seems like a law classifies people by race in a suspicious way.",
"Hate speech *is* protected speech. ",
"Hate speech **is** given the same protections. Incitement of violence is not protected, but hate speech is definitely protected and thriving. Have you never seen _URL_0_?",
"The question is fallacious — hate speech *is* protected by the first amendment. I think you are confused because there is much attention paid to \"hate crimes\", e.g. burning a cross on somebody's lawn or vandalizing their house with swastikas. But in each of these \"hate crimes\" there is some underlying crime (usually violence or vandalism). Pure speech -- even controversial or hateful speech -- is still protected by the first amendment. In America, neo-Nazis can picket Jewish synagogues, the KKK can have a parade, as long as they do it in a law-abiding fashion This is an unalienable right of man and I love all nations that protect this right. ",
"It is difficult to define, but I think it is safe to say that invading someone's dreams and turning them into a staggering monster is not a form of protected speech.",
"Unlike in the US, hate speech is not protected in many countries due to the fallacious assumption that speech itself is dangerous.",
"Relatedly (and where I think your real confusion is coming from) a lot of speech is considered protected, but can be regulated to an extent by the government. When government wishes to regulate protected speech in a content specific way (as opposed to content neutral like saying you can't protest in X location, or you can't protest with signs bigger than Y by Z), they must pass a [\"strict scrutiny\"](_URL_0_) test. This means that the government must have a compelling interest; the law must be narrowly tailored to achieve that interest; and it must be the least restrictive means to achieve that goal. Generally when this test is applied, it means a law is going to be struck down, but there are some situations where the law can succeed under this test.\n\nSide note: that strict scrutiny test is used any time a fundamental right seems to be infringed by a law or when it seems like a law classifies people by race in a suspicious way."
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6zfcws | how do dogs know not to jump out of the truck bed when their driver is speeding down the highway? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6zfcws/eli5_how_do_dogs_know_not_to_jump_out_of_the/ | {
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"Not all of them do know this. Our neighbor lost a dog because it jumped out while the vehicle was moving. ",
"They don't. I had a dog jump right out of my Jeep when I was driving through town one day. She learned her lesson though, and she hasn't ever done that again. ",
"Driving thought rural USA (Wyoming and Colorado) my family started remarking how many dogs in the beds of pick up (and flat bed) trucks there were.\n\n The next realization was how many three legged dogs there were!!! I don't know if this is a coincidence but I suspect there is a cause and effect going on here.",
"Interestingly enough, a lot of this animal behavior can be traced back to an instinctive response to dry eyeballs. \n\nAnimals tend to want to keep their eyes in good working order, which means shielding them from debris and keeping them hydrated. We refresh/clean our eyes by blinking. During a blink the tear glands above the eyeball kick on, as do the lubricating oil glands at the corners of your eyes to cover the eye in a protective liquid. \n\nWhen wind velocity picks up, it not only increases the chance of tiny debris striking the cornea, but it quickly dehydrates the surface of the eyeball. This often causes an animal to squint (physically lower eyelid protection) and attempt to avoid more wind striking their face by reducing their air resistance (called drag) through crouching behind a windbreak (an object that blocks wind). The smaller and more streamlined an animal can make itself, the less wind drag its tender wet orifices will experience (eyes, nostrils, mouth).\n\nThere are other more deeply ingrained stimuli (such as hunting, and fight-or-flight) that can override this instinctive reaction to hunker down, which why you hear about dogs leaping from pickup beds and getting injured. ",
"They don't. That's why they sell [truck bed leashes](_URL_0_), harnesses, and other things to keep the dog from doing something stupid.",
"Tie your dog in the bed people! And make sure you only give them enough leash so they can't get their heads all the way over the side rail. I've heard stories of people who tied them improperly only to arrive with the dog hanging dead off the side of the truck.",
"They dont. We had a dog when I was a kid who was on a leash tied to back of bed. She jumped out and was choking to death as we quickly pulled over and got her loose and brought her into the cab. ",
"Work at a vet. Not all of them know...\n\nIf you have room in the cabin of your truck, that's where your dog should be. "
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1ly0zp | key pairs and public key cryptography | I've tried reading Wikipedia and HowStuffWorks' articles on public key cryptography but I still don't understand it completely. As far as I know, the public key is for decrypting ciphertext, but what does the private key do, and why is it needed?
EDIT: I've search other ELI5 explanations and I still don't understand what the private key does. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ly0zp/eli5_key_pairs_and_public_key_cryptography/ | {
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"Here is a very nice video explaining how it works:\n\n_URL_0_",
"If I encrypt or sign a message with my private key, you can decrypt it, or verify the signature using my public key. That way you can be sure the message really came from me. The message doesn't necessarily have to contain secret information.\n\nIf you encrypt a message with my public key, only I can decrypt it. The benefit is that I only need to publish a single key and anyone can create a message that only I can read."
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17383i | why is inflation something that japan wants, but the us doesn't? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/17383i/why_is_inflation_something_that_japan_wants_but/ | {
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"It's not true that the US doesn't want inflation. We just have enough already.",
"I would argue that *both* Japan and the US want inflation right now. Both are in recessionary situations (though the situation has persisted in Japan for much longer) and both could use a bit more nominal spending, which means more inflation and more growth.\n\nOver the medium term, Japan has settled on an inflation rate of about 0% or a little less. It has turned out that this inflation rate has not been conducive to economic growth.\n\nOver the medium term, the US has settled on an inflation rate of about 2%. That seems about right, given the weight of international evidence.\n\nSource: I'm a real live economist."
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59avws | why did germany respect neutral status in wwii? | Just curious why they respected the neutral stance of Switzerland and Spain while obviously not caring for any position of the other countries they blitzkrieged through and occupied during the conflict. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/59avws/eli5why_did_germany_respect_neutral_status_in_wwii/ | {
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"Spain was in itself fighting a civil war in which the ultra-right group led by General Francisco Franco won. It would have been seen as another potential ally for the fascists and Nazis. Hitler and Italy actually provided some minor support to his Nationalists during La guerra civil, which lasted from 1936-1939. Not only that, but Hitler realized his army was needed elsewhere, and preferred to to focus on lands closest to Germany that he could invade, including lands he felt he had the sufficient upper hand in. The spaniards would have seen experienced fighting because of the war. Also transport through the Pyrenees would be difficult, meaning he'd have to assault from Sea or Air. \n\nHitler had at one point desired to conquer Switzerland and bring it under the Großdeutsches Reich. Operation Tennenbaum was the plan developed to eventually invade Switzerland but was postponed the because of more pressing matters AND because it would have been a logistical nightmare to invade Switzerland partially because A. the mountainous terrain would make transport difficult and B. the Swiss population was quickly mobilized in terms of army reserves and supplies to prepare for an invasion.\n\nThe military strategy of Blitzkrieg is only successful when you can catch your opponent off guard, it would have been fairly difficult to invade those two countries after seeing Hitler attack Poland, France and the Netherlands. ",
"Spain had just gone through a big civil war. They were pro-Axis but still relatively split between factions and had to focus internally to keep the country together. They lent some minor support to both sides but were content to stay in Iberia. Germany couldn't really get to them without going through France anyway. If the war had gone on longer with Germany taking over all of France they may have come into conflict later on, especially as Spain owed both Germany and Italy a debt for helping out with their civil war.\n\nGermany did not respect Switzerland's air space. However the extreme defensibility of Switerland's borders and the Swiss' plan to make any attempt to invade very costly to the invaders basically served as a huge deterrent to anyone actually invading. ",
"At least in the case of Switzerland and Liechtenstein, the Third Reich had plans in the form of [Operation Tannenbaum](_URL_0_), to be executed after they had dealt with their more powerful enemies in Europe. Liechtenstein was to be integrated into the Reich, Switzerland to be divvied up between them and Italy. Eventually the war turned in the Allies' favor and Operation Tannenbaum was scrapped in favor of defensive operations and the development of retaliation weapons.\n\nthe reason why Operation Tannenbaum wasn't executed earlier is kind of a hot topic - to my knowledge, there are no official records addressing the delay.\n\nPossible reasons would be the fact that Switzerland was already mainly helping the German war effort by selling weapons and ammunitions to them and their Italian allies, or the extensive bunker networks set up in the naturally easily defensible Alps at the start of the war. Of course they would've been no match for the Wehrmacht at the height of its power, but it is theorized the Germans deemed the casualties they would've sustained in this attack not worth the price - after all, they saw what happened to the Russian Army in the Winter War and Continuation War.",
"Neither side respected neutrality. Iceland and Iran were both invaded by the allies, for strategic purposes.\n\nThe Netherlands, Denmark, Norway, Greece and Belgium were invaded by the Germans.\nHad the Germans left the Netherlands free, there would be a chance the Dutch would later side with the allies and open up access to German heartlands. The Italians and Germans invaded Greece to get access to the British naval bases which were helping the Brits fight in the Mediterranean.\n\nInvading Switzerland wouldn't have given the Germans any realistic benefits. The Swiss did shoot down both German and British aircraft that flew over Swiss airspace but that wouldn't have been enough provocation to justify an invasion by the Germans. The Swiss were well equipped and ready to fight whilst the Germans had war on several fronts already.\n\nSpain was lead by fascists like Italy and Germany and had in fact been helped by the Germans in the Spanish Civil War but refused to join in the war on behalf of the axis. Fighting the Spanish would have lead to an overextension of the German lines, similar to what happened on the Eastern front. Central Spain is also mountainous deserts which would have been easier terrain to defend than the plains of Ukraine, Russia, France, Benelux etc. which would have stalled any Blitzkrieg attempts.",
"They were using Switzerland. They used them as a laundering service to do trade with countries they could not otherwise trade with due to the war, and they used them as a bank to stash gold, and other loot plundered from Europe due to their banking laws and neutrality. Switzerland is also incredibly difficult to invade. It is very mountainous making air strikes with the types of planes they had difficult (but not impossible) and a handful of snipers could hold the passes. Combine that with the fact that Switzerland has the tradition of fully training and arming their citizenry (to the point of requiring every household to have a military rifle). \n\nThey did not go after Spain because they were still dealing with France. The French civilian resistance and later allied assault prevented them from getting as far as Spain. Had they fully locked down resistance in France or at least gotten it to a low enough mark they likely would have continued on to Spain as in general Germany did not respect neutrality in either World War. \n",
"Sweden was also neutral during WW2. How come the Nazis didn't invade them?\n",
"- Everybody needs somewhere safe to stash their money.\n- No point in worrying about people who aren't going to attack you.\n- They didn't really respect neutrality, see their \"mutual non-aggression\" pact that they had with Russia up until the moment they invaded _**AND**_ the non aggression pact they had with Poland until the moment they invaded.\n\nSwitzerland's status as neutral, and it's status as the banker to Europe are closely tied. The Swiss Alps are notoriously difficult to invade _and_ impossible to hold. And once the Nazi leadership decided to deposit their ill-gotten gains there they became quite protective of the economy (basket) where their money (eggs) were being held. So \"go ahead and put all your eggs in one basket, then guard that basket!\" applies.\n\nNote that Nicaraguans had the same protective attitude to Costa Rica in the hay day of Nicaraguan death squads. Those generals were screwing their own economy at home, but if their squads crossed the boarder and misbehaved they'd quickly find their heads separate from their shoulders when they returned home.\n\nSpain was too far away down the supply lines once the Nazis realized how effective the French resistance was. They couldn't afford to invade Spain if they wanted to keep France fully occupied.\n\nMoney trumps all.\n",
"Germany respected neutrality unless it was in their interest to not recognize it.\n\nFor Switzerland, it was more valuable to have an independent, neutral Switzerland that would conduct commerce with Germany than it would have been to occupy them. And Spain... well, there wasn't much value. You gotta cross mountains to get to them, and it's only on the way to Portugal. There was no strategic advantage to invading Spain.\n\nThough if Germany had defeated the UK, there's an excellent chance they would have gone ahead and taken the Iberian peninsula.",
"Here's what switzerland looks like:\n\n* A mountainous nation\n* Not much in the way of natural resources\n* Every single bridge is rigged to blow\n* Every mountain pass is rigged to collapse\n* Every single citizen is a trained soldier\n* They have enough bunkers to house, feed, and supply their citizens twice over\n\nGood luck with that. While there was operation Tannenbaum, it was a logistical nightmare that could not be accomplished while fighting the allies. Plus the benefits of having a neutral party to launder / hide money is very attractive.\n\nAs for Spain, they were embroiled in a civil war. Best to let them kill each other, especially as fascists were one faction. After the war it would have been an ally, or an easy target.\n"
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1rx5jb | why do stores discount their merchandise during the holiday season? that is, why is it advantageous to decrease prices as demand increases, rather than increase prices? | economics is my weak point, but I always thought that prices should increase as demand increases? I'm sure supply also factors in to that equation .. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1rx5jb/eli5why_do_stores_discount_their_merchandise/ | {
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"It is similar, in a way, to how gas stations will alter the prices of their gas when travel is on the rise in order to increase traffic inside of the store. Essentially the stores are accepting a loss on, sometimes, cheaper merchandise in order to get heavier foot-traffic so they can sell some of their \"normally\" priced goods.\n\nLowered prices act as a way to efficiently get feet in the door in order to boost overall sales in the Christmas season.",
"Without going into detail on supply/demand, its because of two things, in my experience:\n\n1. Margins on products allow for the discount while still keeping a profit\n2. Increased demand due to lower prices will increase product sold, still making a profit\n3. Secondary purchases of items not marked down as heavily might increase product sales, still making a profit\n\nSo, lets say I want to sell a laptop for 250$. It might cost me 230$ to buy in the first place, and MSRP is 350$. In a normal week I might sell 3-4 of them. during a holiday sale I end up selling all of them, along with various other items (mice, laptop covers, warranties, etc.) Plus my store now has extra people coming in, and potentially new customers who might return. This is an advantage to my store.\n\nThere is also the whole 'they're doing it, so we have to do it too!' thing. If one store lowers prices, others generally follow in order to stay competitive. During the last black friday I worked, our GM was really excited because our price for a discounted TV beat best buys by about $50 - thats a marketing point we can use - our sales *beat Best Buys!*. We don't make as much money on sales, but its good because more customers = more return customers = more profit in the future.",
"To respond to your economics question: the reason why prices don't generally increase just because of a demand increase is competitive pressure. One supplier can't just see a demand increase and bump his prices, because the rational response of other suppliers is to keep their prices lower and steal the overpriced supplier's business.\n\nYou can't apply the principles learned generally in a 101 economics class, because those supply and demand curves are drawn with assumptions in place that make the original graph depict an efficient price. these assumptions are information is perfect (so everyone will know if some scumbag supplier is charging more for the good than it costs to make at the margin) and actors are rational (no one will buy an overpriced good). When those highly unrealistic assumptions are in place, the rational response to any supplier's attempt to raise prices is to undercut him so long as the price you charge still covers your costs. \n\nNow, for the real world, where these assumptions rarely hold for a chosen market, the faulty assumption that your question makes is that the prices before the holidays were efficient to begin with. They weren't. You want proof? They charge less on \"huge deals\" and still turn a profit, meaning the higher price from before made them an even bigger profit. "
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7mka8z | why does toilet paper get wrinkly as you near the end of the roll? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7mka8z/eli5why_does_toilet_paper_get_wrinkly_as_you_near/ | {
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"Didn’t work with toilet paper but when I worked at a factory (think tape and other assorted things) I worked on a winder line. Sometimes when the rolls were not tightened on all the way (without getting into too much detail) they would wrinkle, but depending on what type of adhesive the tp manufacturer uses it could just be that the tp folded over. Hope this helps!"
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8q2g5j | when inhaling deeply, why do you start to struggle, your intake of oxygen gets almost shaky? is this your lungs reaching absolute maximum capacity? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8q2g5j/eli5_when_inhaling_deeply_why_do_you_start_to/ | {
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"Probably your diaphragm (the muscle that allows lungs to inhale/exhale) reaching its limit of contraction.",
"The alveoli (microscopic little air sacs) that make up your lungs expand and contract as you inhale and exhale. Due to the surface tension of the fluid inside them, they naturally want to contract, without you having to force air out. However, the contractile force is weaker and weaker the more expanded they are because of weird chemical reasons that would require a drawing to explain.\n\nRegardless, once you get to a certain level of expansion, the contractile force from the surface tension in the alveolar fluid is roughly equal to the force on your lungs from your heart beating. Hence you start to almost gasp in and out with your heartbeat as your lungs reach their total capacity."
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4330px | plot of the film "the big short" | So, i am the person who doesnt understand most basic economic terms. Plus, english is not my first language, there are a lot of things in USA economy system that just dont exist in my country, so i cant understand the plot of this film. But im very interested in it, i did watch the first 10 minutes of it and then i got stuck in wikipedia and had read meaning of the terms for another hour. I still dont understand a lot of it. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4330px/eli5plot_of_the_film_the_big_short/ | {
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"Banks normally issue mortgages (loans) to help people buy houses. They realized that they could sell these mortgages immediately, to investors who wanted to get paid back later and earn the profits. This was a fast way for banks to make some money. \n\nThey grouped thousands of mortgages into a pile and sold each whole pile, so investors would not need to be sure that *every* home buyer would make their mortgage payments -- as long as *most* paid back their loans, the pile of loans would be valuable.\n\nThe problem is that they started lying about the quality of loans. Many piles contained lots of mortgages issued to people who were *quite unlikely* to ever be able to pay back the whole thing. So a set of mortgages that appeared to be worth (for example) $100 million might only be worth a fraction of that. Investors didn't bother to notice since they assumed no one was lying to them.\n\nA tiny number of investors noticed the problem, but the people making money on the lies told them to shut up. This lasted for a while until too many people stopped believing the lies. Then the whole system collapsed. A few people who had made bets against the liars made a big profit. But most people lost a lot of money; millions even lost their jobs and their homes.\n\nThis is a true story, not fiction.\n\n"
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7cakmq | why waves ? all energy transfer in nature from one point to another happens in waves. light, sound, even gravity travels in waves. which fundamental property of nature is responsible for wave like nature ? are there other non-wave like ways to transfer energy from one point to another ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7cakmq/eli5_why_waves_all_energy_transfer_in_nature_from/ | {
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"Waves are a metaphor we invented, to describe the way that forces travel through space -- from one spot to all the adjacent spots, or all the adjacent spots in a particular direction.\n\nThe way our universe works, forces always travel through space. Many (like magnetism and gravity) spread at the speed of light, though some (like sound) spread much more slowly.",
"The short answer is probably pretty unsatisfying: because that's the way it is. There is no reason that light, energy and everything else *has* to move in waves. In fact, some really smart people (such as [Isaac Newton](_URL_1_)) initially thought that light was just particles that moved in a straight line.\n\nHowever, eventually we observed phenomena like [diffraction](_URL_3_), which posed a serious problem for the idea that light is just a bunch of particles flying through the air. However, diffraction and other such phenomena are easily explained if light is a wave. \n\nSo light must be a wave? Not so. Albert Einstein came along and solve the problem of the [photoelectric effect](_URL_0_), which he did by assuming that, instead of waves, light actually *was* just particles flying around. \n\nSo who's right? Those who observed diffraction and said light must therefore be waves? Or those who observed the photoelectric effect, and said that light must therefore be particles? The answer is, both and neither. And an [experiment](_URL_2_) was done that showed just that. Turns out, light is not a wave, although it acts like a wave sometimes. And light is not a particle, although it also acts like a particle. It's something totally different.\n\nAll mass and energy in the universe is now understood to have wavelike and particle-like behavior. So no, there is no way to transfer energy that avoids the wave-like nature of mass-energy.",
"It’s not really waves but something else entirely. They behave according to an equation that sometimes acts like a particle and sometimes a wave- it’s just a quantum oscillation. The reason it does is because it does. All we really try to explain is the what not the why.",
"When particles of any type of energy are emitted from a common source, they knock into the fabric of space, which although it may seem empty, is actually full of 'space' particles.\n\nWhilst seemingly invisible, space particles react to all types of energy particles, such that when space particles are struck by an energy particle, a particle of the same type and magnitude is ejected from the diametrically opposite side of the space particle. Like a 3-D domino effect.\n\nResulting in what seems like a continuous stream of the energy particles. As the stream of energy particles reach a harmony, the resulting harmony becomes a wave with a frequency.\n\nDifferent energy particles have different frequencies and move through space at their allocated speed. For instance, a neutrino could travel through 16 trillion light years of steel as if it wasn't even there.",
"TL;DR: If any physical system in nature satisfies these three criteria, then we can expect to find wave-like behavior:\n\n* *If a disturbance only propagates by affecting its immediate surroundings.*\n\n* *If the medium is the same in all directions.*\n\n* *If disturbances don't generate significant entropy through diffusion, friction, etc.*\n\nMany systems in nature fall roughly under this category: water, air, a block of wood, even human stampedes.\n\nI disagree that there can be no intuitive reasons given for why waves exist.\n\nOne can equivalently ask the question: Why does the [wave equation](_URL_4_) describe so many physical systems so well?\n\nIf you are unfamiliar with partial differential equations, I'll ask you to imagine a lake, with waves rippling across it. You can imagine a little buoy on the surface, [bobbing up and down](_URL_3_).\n\nYou can think of the wave equation as describing the bobbing motion of the buoy. In fact, the wave equation also describes the bobbing motion of the lake's surface at any location on the lake.\nThis is what is known as a [field equation.](_URL_9_) \n\nThe mathematical form of the wave equation tells you that the second time derivative of the field and the second space derivative of the field are proportional to one another (The proportionality constant being the square of the wave speed).\n\nThis sounds jargon-y but we'll see that it translates into the more intuitive terms, *force* and *curvature*.\n\nThe second time derivative is the acceleration, and represents the force on the buoy (per unit mass), and the second spatial derivative represents the curvature of the water's surface just around the buoy. \n\nWhat the wave equation then tells us is that the force on the buoy is proportional to the curvature of the water around the buoy. \n\nIn [this](_URL_6_) picture, you can see that when the buoy is at a low point, the curvature of the wave makes a smiley-face shape, which is (mathematically) positive, and thus the force on the buoy is positive too. Similarly, when the buoy is at a high point, the curvature of the wave makes a frown-y face shape, which is (mathematically) negative, and thus the force on the buoy is negative too. At equilibrium, the curvature is zero, and thus the force on the buoy is zero. In all cases, the buoy is pushed toward equilibrium, and this push is known as the *restoring force*.\n\nSo we've seen that the wave equation describes water waves pretty well. Before you feel underwhelmed by the seemingly simple behavior of water, note that the wave equation appears *multiple* times in the description of water! As [sound waves](_URL_5_) in water, where the restoring force is pressure, as [gravity waves](_URL_7_), where the restoring force is buoyancy, and as [capillary waves](_URL_1_) where the restoring force is the surface tension. And water can boil and freeze, which cannot be described by the wave equation at all! Water *is* complicated, so the fact that the wave equation can describe many properties of it, as well as many other parts of nature, is worth further discussion:\n\nWhy does the wave equation have the form that is does, and how do we use that understanding to see why it appears in so many parts of nature?\n\nFor starters, notice that the wave equation involves derivatives. This immediately tells us that the wave equation will *only* apply in scenarios where there is a notion of [locality](_URL_8_). If objects could remotely influence distant objects, then the resulting behavior can not be expected to be wave-like.\nWhat this tells us then, is,\n\n* *If we have a physical system where each component only affects its immediate neighbors, and no one else, then that physical system is a candidate for displaying wave-like behavior.*\n\nSecond, we notice that the wave equation involves *second* derivatives. (Note the t^2 and the x^2 in the denominators of the equation.) This tells us that there is a *symmetry* when we replace t with -t and x with -x in our wave-equation (because t^2 = (-t)^2 and likewise for x and -x). The symmetry in x tells us that wave-like behavior happens in systems where there is no difference between disturbing the neighbor to your left versus disturbing your neighbor to your right.\n\n* *If we have a physical system where the medium is the same in both directions, then that physical system is a candidate for displaying wave-like behavior in that direction.*\n\nFinally, the symmetry in t tells us that wave-like behavior happens if we have a time reversible system (no entropy-generating processes like diffusion or friction).\n\n* *If we have a physical system where disturbances are time-reversible, then that physical system is a candidate for displaying wave-like behavior.*\n\nIn summary, if the physical system has these properties, energy will be transferred via waves. But nature has plenty of time-irreversible examples of energy transfer as well! Such as [advection](_URL_0_) and [diffusion](_URL_2_). "
]
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"https://en.wikipedia.org/wiki/Photoelectric_effect",
"https://en.wikipedia.org/wiki/Corpuscular_theory_of_light#Sir_Isaac_Newton",
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"https://en.wikipedia.org/wiki/Diffraction"
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"https://en.wikipedia.org/wiki/Advection",
"https://en.wikipedia.org/wiki/Capillary_wave",
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"https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2015/2-experimental.gif",
"https://en.wikipedia.org/wiki/Wave_equation",
"https://en.wikipedia.org/wiki/Underwater_acoustics",
"http://mgh-images.s3.amazonaws.com/9781133954330/13220-1.8-52IE1.png",
"https://en.wikipedia.org/wiki/Gravity_wave",
"https://en.wikipedia.org/wiki/Principle_of_locality",
"https://en.wikipedia.org/wiki/Field_equation"
]
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||
2m3v7v | why can't phone just film in horizontal all the time if the lenses are circular? | If a camera lense is just a circle, wouldn't you be able to always film in horizontal? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2m3v7v/eli5_why_cant_phone_just_film_in_horizontal_all/ | {
"a_id": [
"cm0p3c0"
],
"score": [
6
],
"text": [
"The lens is circular, but the image sensor that captures the image is a rectangle."
]
} | [] | [] | [
[]
] |
|
5iaxc0 | why do many otc pills like tylenol or cold pills have a warning saying not to crush or chew them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5iaxc0/eli5_why_do_many_otc_pills_like_tylenol_or_cold/ | {
"a_id": [
"db6oz46",
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"text": [
"That's the point, the pill was designed to release a certain amount of the drug over a long period of time rather than a burst all at once. If you crush it it's not going to give you the hours of symptom reduction on the box, and could lead to potentially dangerous side effects from the large amount of the drug going into your system all at once. ",
"Three reasons, all having to do with what is called \"enteric coating\":\n\n1) Some medication is designed to be digested over a period of time, either to prolong the effect or to allow the body to slowly reach a therapeutic level of the drug. Crushing the pill exposes your body to all the medication at once. \n\n2) Some meds can cause damage in your stomach. The coating protects you from that. \n\n3) Some medication needs to be dissolved in the intestines. Destroying the coating means it will be dissolved in your stomach, and it won't work correctly. "
]
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[],
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||
3orptw | how is an island made artificially? like what china is doing the south sea. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3orptw/eli5_how_is_an_island_made_artificially_like_what/ | {
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"cvzu7dm"
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"score": [
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"text": [
"You take sand from all over the area and pile it on top of a reef or other relative high point underneath the water until the pile is tall enough that its peak is always above water. You now have an island."
]
} | [] | [] | [
[]
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||
330u7p | how is the money calculated from advertisements on a website? is it based on views, clicks or a combination of things? | So me and my friends created a website _URL_0_ because we were bored and are trying to earn a bit of money from advertisements but are not sure where we are earning our money from. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/330u7p/eli5_how_is_the_money_calculated_from/ | {
"a_id": [
"cqgfnvu"
],
"score": [
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"text": [
"Probably mostly based on clicks, but either is possible. Originally, paying for views was the standard, usually expressed as a cost per thousand impressions or CPM. Networks like Adsense saw a shift towards cost per click, though there are still some impression-based campaigns through networks and it remains common to charge on a CPM basis if you're selling direct to the advertiser. It's also quite common to pay only when the ad leads to a sale, known as CPA (cost per acquisition). That may be a fixed fee or a percentage of the sale. You'd generally know if you're doing anything CPA-based, though."
]
} | [] | [
"http://www.doigiveashit.com/"
] | [
[]
] |
|
6oqy0j | how can a movie be "on film" if all the editing and effects work is digital? | With Dunkirk coming out this weekend in 70mm across the US, what is the point of shooting on film if it's just going to be transferred onto a computer for editing? I wouldn't you lose some of the picture quality? How is this any different than just transferring a movie that was shot digitally onto film for exhibition. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6oqy0j/eli5_how_can_a_movie_be_on_film_if_all_the/ | {
"a_id": [
"dkjhfis"
],
"score": [
4
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"text": [
"They use high-resolution scanners to convert the film into digital. This is different than shooting digitally because it was shot on film - the movie is still composed of lighting hitting chemicals and causing a reaction, even if it has been transferred. When it's transferred to digital, it maintains the dynamic range and grain that characterizes quality film stock. "
]
} | [] | [] | [
[]
] |
|
49ncwe | google's search prediction (aka mind reading) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/49ncwe/eli5_googles_search_prediction_aka_mind_reading/ | {
"a_id": [
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"You probably have visited certain sites that other people who have searched that have also visited. Google knows this and is able to figure what you might search. They more than likely have profiled you based on your internet use. And when I say you I mean everyone.",
"Google stores all the searches you type into it. It also stores all the searches other people do. It in addition stores all linkes between website on the internet and the general content of the websites. (and some other things - in fact a lot of other things regard data; if you use google'S browser and said yes then it knows where you are browsing to and fro).\n\nFrom there Google's server farms simply make \"clever lists\" as prepared information.\n\nTake searches from a person A) \"Witcher 3\" \"Witcher 3 help\" \"Pizza puzzle\" \"Has Geralt ever done that?\"\n\nNow we can suppose that there's something with a pizza and something with Geralt in something called \"Witcher 3\". But that's only one sample. Other persons might search other combinations of terms, but if these combinations frequently contain \"Witcher\" and \"Geralt\", we can simply count the occurences when this happens and assign a probability to it (80 of 100 search histories contained Witcher and Geralt close to each other makes 80% probability they have something to do with each other). With the pizza that was odd, no other search histories had Witcher and Pizza close to each other, so that's only a 1/100 or 1% probability this makes sense.\n\nNow comes /u/silky_flubber_lips. He searched a lot of Witcher 3 in the past. Oh now the is typing \"Has G...\", well let's look into our list of things linked to Witcher 3 with a high probability and see if something matches. 80% sure \"Has G\" will be finished with Geralt done that says the list. Here you are, have all the search term."
]
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[],
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||
40fjhz | how does sizing a turbocharger on a car work? | I apologize if I've already fucked something up, as this is my first post on reddit. Anyway, I've just purchased a 2013 Subaru Impreza WRX. From all of the research I've done, most people have said it's an amazing car, both in terms of reliability and performance. It's a bit too early to tell how reliable it will be, but let me tell you- it drives like a dream. My previous car was a 2004 Acura TL, 3.2L v6 with a 6 speed manual transmission. While it was a lot of fun to drive, It had 200k+ miles on it and it was time for an upgrade. The Impreza WRX is a 2.5L flat 4 with a 5 speed manual transmission, and also happens to be turbocharged. Now I've done my research on turbo maintenance/upkeep ect. However, one thing I could not for the life me grasp is how the turbo sizing works. I've never owned a turbocharged car before so it's a bit of a new territory for me. For example, If someone were to ask me "what kind of engine is in the WRX?" It would be an easy answer. However, if someone were to ask me "what size is the turbocharger in your car?" Id have absolutely no idea how to answer, and would probably just sit there like a dumbass. If anyone can help explain it to me I'd appreciate it. And again, apologies for any errors | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/40fjhz/eli5_how_does_sizing_a_turbocharger_on_a_car_work/ | {
"a_id": [
"cytwb5n"
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"score": [
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"text": [
"There are lots of ways to identify the dimensions of the compressor itself, and you could always just give the model of the turbo. \n\nMostly, though, people will just want to know at what RPM it starts to make boost, and how much it makes when it does. "
]
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[]
] |
|
2ng5km | - how do good actors portray characters that are bad actors? how do they intentionally act poorly while still managing to be good at acting poorly? | Examples:
Sweet Dee from It's Always Sunny in Philadelphia
Tobias from Arrested Development
Many other "struggling actor" archetypes
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ng5km/eli5_how_do_good_actors_portray_characters_that/ | {
"a_id": [
"cmde182"
],
"score": [
5
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"text": [
"There are different acting methods and ways of viewing the craft, so it's going to vary a little from actor to actor. I can only speak as someone who did a couple shows in high school, and who played characters who had varying skill in lying or not lying for what worked for me. If I were better researched on the craft I could tell you about the techniques professionals use, but I noped out of the field after high school, research and all. \n\nThe technique I used--which was mostly just me doing the same play-pretend stuff I did as a kid encouraged by \"Wow Carly, you're such a good actor! Maybe you'll go to hollywood when you grow up!\"--was that I tried to pretend I actually was the character and think and feel the way they felt. This was natural to me because I spent a lot of time writing stories and playing pretend as a kid, and I watched a lot of TV and had memorized a lot of the little visual things actors do to get something across. But I would just be constantly thinking about the lines, about what happened to the character before, and about how they felt now, what they were planning. And I guess my body language and voice just kinda changed to match what I was \"feeling.\" \n\nIn two of the plays I was in, I had to play characters who tell very big lies that screw up everything for everyone else in the play. One of the characters was a good liar, and one was a bad liar. In real life, I'm actually an awful liar because I'm not very well practiced. My good liar, though? She had a plan and she knew exactly how to pull it off, so I knew she'd be confident, and I know she's literally did not care what it did to anyone else. I focused on what she would be feeling, on the confidence and poise and the smug satisfaction of \"you stupid SOBS have no idea\" she had going on.\n\nMy bad liar was really upset, and told the lie just for spite. It was so, so obviously untrue that I cannot believe any version of the character she lied to believed it. I just stayed in the place she was in, which was more or less \"HAHAHAHA TAKE THAT\" and delivered the line with the over the top rage that motivated it instead of the more restrained bitterness or even angry sympathy that would have been called for if the line were true. The character she was lying to is dumb as a box of rocks and the audience knew I was lying, so really any emotionally inappropriate delivery would have flown there. I could have acted super happy, super sad, anything extreme... as long as it wasn't subtle or normal or right.\n\nSo TLDR, in my case, I was really good at convincing myself for a little bit that I was the character and imagining how they felt and what exactly they were thinking. If I had to lie well, I had them engage in the same process. If I had to lie badly, I focused on what they were feeling instead of what the lie should have made them feel, and maybe cranked it up just a little bit past what felt right to me. Actors who use a different process would have a different way of doing it, but the net \"output\" of having the character not act the way the actor feels like the audience would expect for a \"good\" performance is gonna stay the same in many cases. "
]
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[]
] |
|
5u0c2c | is literally every organic thing made out of carbon? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5u0c2c/eli5_is_literally_every_organic_thing_made_out_of/ | {
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"ddqblnv",
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"text": [
"Pretty much. Carbon-based compounds are so numerous and varied that you're bound to find them in anything derived from something that was once alive. Coffee beans were alive, gum has sugar which comes from plants (and natural gums which also come from plants), etc. Organic chemistry, or chemistry based on carbon, is about 50% of all chemistry.",
"Not \"made out of\" but \"containing\". And yes: the very definition of \"organic compound\" is a compound containing carbon atoms, except for the very simplest ones like carbon dioxide or... well, carbon itself.\n\nIt used to be that organic compounds were compounds that were or had been, in some sense, \"alive\" or made by living organisms, but then somebody successfully made IIRC uric acid in a laboratory, so they had to change the definition.\n\nThe simplest organic molecule is methane, which consists of a carbon atom and four hydrogen atoms (CH₄), but organic compounds are usually much more complex. For example, vitamin B12 has the chemical formula C₆₃H₈₈CoN₁₄O₁₄P, although writing it out like that isn't very useful.\n\nCarbon is great for making complex molecules because of the way it can form bonds with other carbon atoms to make long chains or rings. There has been some speculation as to whether some alien life form might use silicon, which is similar, but until we find some silicon-based life form, we'll probably never know."
]
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[],
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||
2jyoaq | why are people who write plays called 'playwrights' and not 'playwrites'? | Well? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jyoaq/eli5_why_are_people_who_write_plays_called/ | {
"a_id": [
"clgad97",
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"text": [
"Amazing what a bit of research can do.\n\n_URL_0_\n\n\"Wright is an occupational surname originating in England. The term 'Wright' comes from the circa 700 AD Old English word 'wryhta' or 'wyrhta', meaning worker or shaper of wood. Later it became any occupational worker (for example, a shipwright is a person who builds ships).\"",
"It is the word Wright that means craftier or builder. Wheelwright, Shipwright, etc. "
]
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[
"http://en.wikipedia.org/wiki/Wright"
],
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|
6f78jt | when someone in a movie is shown to have a cocain overdose, their nose is bleeding before they die. is it really like that and what causes this? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6f78jt/eli5_when_someone_in_a_movie_is_shown_to_have_a/ | {
"a_id": [
"difxpcj"
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"text": [
"The nose bleed is related to the cocaine not the OD. Taking anything in through the nose causes a thinning of the skin walls of the nose, which makes it more likely that the nose will bleed, the same thing happens with nasal sprays. The likelihood of a nose bleed happening after an OD is likely greater due to the fact that a person suffering from an OD on cocaine is likely a person who has built up the amount they use and thus likely has a thin nasal wall in the first place, and the amount of cocaine it would take to OD would have likely torn the skin in the process, leading to a bleed."
]
} | [] | [] | [
[]
] |
||
5sgtv1 | why are japanese game titles often just strings of arbitrary words? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5sgtv1/eli5_why_are_japanese_game_titles_often_just/ | {
"a_id": [
"ddexzak",
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"These are titles that were released in Japan with the title in English, so there is a bit lost in translation as they are trying to make their titles work with the way the game is. Here is the reasoning behind the titles in your example:\n\n*Bravely Default* is an RPG where you have a \"special ability\" to either be \"Brave\" and perform an extra action in a round while giving up your ability to do anything the next round or \"Default\" when you basically do nothing but defend, but allow your character to perform a \"Brave\" move the next round without penalty. Hence the name \"Bravely Default\".\n\n*Melty Blood Actress Again Current Code* is actually a title with two subtitled names. The overall game name for the series is \"Melty Blood\" which is an arcade fighting game about vampires (i guess the blood just melts in their mouth?). The expansion is called \"Actress Again\" which adds some new characters to the \"Melty Blood\" fighting game (so, new actresses). The \"Current Code\" is actually an arcade port to the PS2 which includes the Melty Blood with the Actress Again expansion (so, recoded to work with PS2). So, you get \"**Melty Blood:** Actress Again *Current Code*\" as the full title.",
"You've mostly come up with the correct conclusion. English on Japanese products is considered \"cool\" because of the \"exotic\" factor--almost how we like seeing foreign words on English products. That's why you'll see a lot of products deliberately having weird and strange English words or slogans stringed on video games, food, or anything. It's phenomenon has been coined as \"Engrish\" (Seriously not being racist here).\n\nHere's a fun video of \"Engrish\" marketing examples in Japan: _URL_0_"
]
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[],
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"https://www.youtube.com/watch?v=kZ-dBHCHo3E"
]
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||
34fr8w | why isn't singapore part of malaysia? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/34fr8w/eli5_why_isnt_singapore_part_of_malaysia/ | {
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"Singapore was part of Malaysia up until 1965. What happened was that the Singaporean state government disagreed with a lot of the policies that the Malaysian federal government implemented. This culminated in the 1964 Race Riots. \n\nAfter further disagreements, the Malaysian parliament voted unanimously to expel Singapore from the federation. The thinking behind this was that Singapore at the time was poor with no agriculture beyond fishing, little fresh water and practically no industry. Malaysia expected that Singapore would come crawling back to the federation at a reduced bargaining position. \n\nSingapore managed to bounce back with a vengeance and it makes little sense for them to rejoin the federation now. Primarily because of the meritocracy that Singapore is based on conflicts with the ideology of the ruling party in Malaysia. "
]
} | [] | [] | [
[]
] |
||
4ctfwe | why is it the older i get, the less significant i feel compared to the rest of society? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ctfwe/eli5_why_is_it_the_older_i_get_the_less/ | {
"a_id": [
"d1laxpa"
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"text": [
"Children have a very small sense of the world that slowly expands as they get older. When you world is small, you naturally tend to feel like a big part of it. The older you get the more you realize that the world is really big, but not only that but there are lots and lots of other people just like you. \n\nYou can probably go on Google and find someone who looks almost exactly like you and has a similar name in just a few hours. \n\n"
]
} | [] | [] | [
[]
] |
||
5j8csv | why do we pay health insurance companies so much money, yet they refuse to cover the cost of a medical expense that's usually less than half of what we've given them over the life of the account? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5j8csv/eli5why_do_we_pay_health_insurance_companies_so/ | {
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"They are for-profit companies. The less they pay out, the more profit they make.\n\nSure, for smaller amounts maybe they'd be better off not spending employee's time disputing things with you, but the general principle holds.",
"Actuary here (I work in insurance). Your policy has limits and deductibles. What you actually pay over the lifetime of the account isn't what limits your coverage for a specific event. If this happens to be your first claim during the year, then your deductible gets subtracted from the claim amount. If the claim is also above your limit, whatever is above that limit gets subtracted as well.\n\nYou haven't really given any more details about your policy to warrant a full discussion, so you'll need to look into the actual contract wording to find out why.",
"Depends on what you're referring to.\n\n1. They won't cover it at all? Perhaps the procedure is \"experimental\" or the doctor/hospital is \"out of network.\" This would be explained in the denial letter.\n\n2. Deductibles? You have to spend $X amount before they start coverage.\n\n3. Co-pay? You pay Y% and they pay Z%.\n\n4. Are you being purposely vague? You may be a perfectly healthy human being who only has one procedure done once every 5 years. However, there are many people out there who would spend more money on medical care than insurance (if they weren't covered). My husband, for example, has chronic back pain. He's only in his 30s and has received several steroid injections, 2 surgeries, monthly prescriptions, MRIs, and CAT scans. Trust me when I say we are very thankful we have a decent insurance program. It's only because both healthy and unhealthy people subscribe to insurance does the system work. I'm sure you could say the same about your car insurance too. We haven't had tickets or a wreck in a very long time, yet we still pay our insurance twice a year.",
"Most people have to pay in more than their claims, so that people who have big claims can get paid.\n\nPeople get confused about this, and think that insurance should reduce their day to day costs. It doesn't work like that.\n\nYou pay car insurance, and you hope you have no claims. With health insurance, you have some claims anyway, so you have to pay even more in premiums. ",
"Could it be because the other half the time it's 10-100X more than we paid in, e.g. a catastrophic expense?",
"Having insurance doesn't mean you get covered for anything. Nor is there any dice rolling involved with making a claim.\n\nWhen you started paying for your insurance, you made an agreement with the insurance company that you will pay $x a month to be covered for A, B and C, not for anything, just A, B and C. You read the policy and decided that $x was a fair price to be covered for A, B and C, signed or clicked yes or whatever. It's a business transaction, money in exchange for a precise service. If you're trying to claim for D then you will be rejected.\n\nExactly what A, B and C are is outlined in very unambigous language in your policy documentation. You can read it any time, and you would have been able to read it before you signed up.\n\nIf you read it thoroughly, there will never be any specualtion involved with making a claim. You will know exactly what is covered and what isn't.\n\nAnecdotally, my so and I have made a dozen or more claims in the past couple of years ranging from a few dollars to several thousand, not a single rejection, because we know what is covered by the policy, because we read it.",
"For the people posting about profit maximization, health insurers have to pay out a standard percentage of their revenue in the form of claims. They can't just deny their way to unlimited profitability.\n\n\"The Affordable Care Act requires health insurance issuers to submit data on the proportion of premium revenues spent on clinical services and quality improvement, also known as the Medical Loss Ratio (MLR). It also requires them to issue rebates to enrollees if this percentage does not meet minimum standards. The Affordable Care Act requires insurance companies to spend at least 80% or 85% of premium dollars on medical care, with the rate review provisions imposing tighter limits on health insurance rate increases. If an issuer fails to meet the applicable MLR standard in any given year, as of 2012, the issuer is required to provide a rebate to its customers.\"\n\n_URL_0_\n\nSomebody downvoted this? Geez. At some point, facts are good. ",
"Insurance isn't based on you, it's based on us. \n\nELI5 Example: Go grab a die. Imagine what ever you roll on the die is how much you'll spend in medical expenses each year. You rolled a 5, so you spend $5. If you have 30 of your friends do this each with their own die, you'll get quite the range of answers ($1-$6). However insurance is the idea that no matter what, everyone will pay the 'average' of $3.5 a year to the company and the company will cover the costs. So you rolled $5 thus you made money! However your friends rolling a $1 lost money. That's how insurance is priced. In this example the die is only coverage for 6 different procedures. \n\nLets say you go off and get your D-20 die and you roll a $2. You cost less than the $3.5 you paid in, so the insurance company should be happy right? Nope, because if they cover you rolling the D-20 die, they have to cover everyone rolling a D-20. Now they have to pay out an average of $10.5 to everyone while only receiving $3.5. Not very feasible, unless they raise prices.\n\nInsurance is never ever EVER about the individual, it only works and makes sense when looking it as a group. \n\nAlso remember being for-profit as well as employee costs and such has to also be added to how much you pay to the company.",
"Think of it as an agreement. The insurance company has said they will pay for 100 people to get their healthcare covered, at a certain level of baseline risk. For every 100 people in a certain range of ages, you can expect 2 to die in horrible accidents, 10 to get cancer, 10 to get heart attacks, and 20 to have medical needs. This means that they will expect to pay $100,000 dollars for the 100 people. This money comes from the other people who are not sick.\n\nThey usually \"refuse to cover\" if they believe that the group of people covered are not \"usual\". For example, lets say that after you sign up, one of the persons says \"Oh yeah I have cancer too, I just forgot to tell you\". The insurance company sees this as a \"preexisting condition\" and never factored you into the equation to understand your risk...in fact they thought you would be well. Now the insurance company has to pay $200,000 because one person forgot to mention they have a condition that would be high cost. \n\nOverall, the idea is cover costs for those who are at an understood risk in a population, using money from the total pile of folks, many of whom will not be sick. However this agreement is based on understanding how sick you are vs how much money you spend in healthcare and making sure your premiums match in a way that a) you still want to pay for it b) they make money to cover their costs and to make money for shareholders c) they dont get sued\n\nUsually when a doctor and an insurance company argue over if something should be covered, they refer to the contract they signed. Very often it will have the limits and conditions agreed upon. If there is further argument, the insurance company doctor and the treatment doctor will hash it out on the phone. The insurance company doctor is paid oftentimes based on overall savings to the insurance plan, so there is a lean towards refusing to cover things \"outside the normal\" or \"experimental\".\n\n\"Experimental\" is another term for \"not covered by the FDA for that indication\". So if the FDA says marijuana is not FDA regulated to treat seizures, you are likely not going to get your insurance company to pay for it. Even if it helps, and is the only drug that works, etc. Many procedures and medications are like this...BUT...your employer or whomever is giving you the insurance also signed on the contract that they agreed to those terms.\n\nIf you cover pre-existing conditions, your costs are going to be higher, thus you need to spread that cost around a larger number of people. If you refuse to get insurance? Well thats the individual mandate Obamacare imposes to get that money anyway. Get rid of the individual mandate and the insurance companies have no way to cover the cost of providing care AND making money while doing it.\n\nSo, in summary, its an agreement to cover a group of people. Someone is getting more care than they pay in premiums, but many many more are getting little to no care at whatever premium to make up the difference.\n\n\n\n"
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adccib | if the amazon echo doesn’t start processing audio until you say “alexa”, how does it know when you say it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/adccib/eli5_if_the_amazon_echo_doesnt_start_processing/ | {
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"There is a special circuit which is listening to everything waiting on \"Alexa\". When it hears that word it will wake up recording and language processing for the rest of the speaking, but until then it is just that single chip which can only recognize \"Alexa\" and records nothing.",
"They say it only records a loop of, I think 2s, constantly overwriting itself. So it is always listening, but its not saving the audio, just keeps 2s at a time and checking if \"Alexa\" is in that snippet. If it detects the wake word in that snippet, it will wake up and start recording.\n\nOf course even if that is 100% true, they aren't 100% accurate in detecting the wake word, and it can be woken up and start recording on other similar words. \n\nNo matter what, I personally would never put one in my home.",
"To put it as simply as possible, this is the process that happens:\n\n1. There is a chip that is always listening in the echo. It doesn't record, doesn't transmit to Amazon.\n2. When this chip hears the wake word (Alexa, Amazon, Echo or Computer, whatever you have set) it activates a buffer, recording a bit (less than a few seconds)\n3. This is sent up to Amazon where their better processing (their servers are obviously more powerful than an echo) verifies the wake word was said\n4. If the wake word wasn't said, the buffer is purged. If not, the buffer gets analyzed along with any continued speech for commands\n\nThe buffer is used so it is smooth, otherwise, you'd have to say \"Alexa\" wait for it to verify, with a pause, then state your command. The couple second buffer allows smoother \"Alexa, turn on the lights\" type commands",
"Here is something to think about. On Android, there is a little software you can chose to install. Basically when a song plays in the background, it will show the artist and title on the lock screen\n Obviously, I freaked out that it's listening all the time. It is, but it does it offline. Takes about 500mb.\n\nNow, it does it by finger printing. 500 mb and it recognizes most songs. Just imagine how easy it would be to finger print most basic words, expressions and so on. Like \"family Guy\", \"new TV\", \" I like the new Ford\" and so on...\n\nI would bet money they do know what you are talking about..",
"It's always listening *locally* without recording or sending ~~days~~ data over the internet to the cloud servers until it hears the wake word. Then it starts sending all audio up to the cloud for processing. ",
"It is always processing audio - the Echo is always storing the last ~10s of audio and looking for a hotword (\"Alexa\", \"Amazon\", etc.). After it finds the hotword, it starts recording. That recording is then sent off to an Amazon server somewhere and fed to a neural network that transcribes it into actual words. From there, another server parses your command and does the things necessary to make it happen (communicating with your lightbulbs, ordering a package, or sending some music back, for example).\n\nThe only difference between before and after you say \"Alexa\" is the Echo connecting to an Amazon server. Keep in mind that the ~10s audio buffer is only stored on your device - it's only after you say the hotword that your voice is recorded by Amazon.",
"I just read the article in the link below, and apparently you can access all recordings from your Alexa on the app. \n\n_URL_0_",
"I like to think of it like a dinner party - you are constantly able to hear what everyone else is saying at the table, but you don’t pay attention and actually listen until you hear your own name. \n\nAlexa works similarly, ‘hearing’ what you say (through a looping recording process), but not really listening until you say the wake word. ",
"I wish you could customise the Echo/Google trigger phrase. I'd love to be able to say 'hey man' (or something casual but less easy to accidentally activate) instead. I'd feel like far less of a dick lol",
"Everything is always listening. I've had many conversations with friends in person where they bring up something and within an hour I'll have an ad for it on FB, Amazon, etc. Even when I dont search for it myself. There is no privacy with technology around. ",
"Don't believe anything! It's listening to everything!!!!!! I'll sell you a special aluminum hat so it can't read your thoughts, only 100$.",
"There are 2 different listening programs. \n\nOne is very simple, only understands a few words (the \"wake up\" command) and is permanently running. It listens for a few seconds, if it doesn't hear the key words, it deletes whatever it recorded and starts again. Over and over. \n\nOnce the first process detects the wake up command (Okay Google, or Alexa, or whatever) it launches the second process. \n\nThe second process connects to its parent server cluster (Google, Amazon, etc) through the Internet, and is ready to accept your command. \n\nOf note, the little gizmo in your home isn't actually powerful enough to translate your speech to text and search. All it does it record the sounds and send it back to a big server cluster somewhere for the heavy lifting. ",
"To anyone that thinks it's sending a constant stream of audio to Amazon, you are delusional, mostly.\n\nI don't dabble in the tech, as much as i know how much data it takes to record and store audio, it would not be worth it to save your audio at any point. \n\nOn the flipside it's entirely possible/probable that based off of your digital footprint, they are collecting certain words and phrases in order to sell you products via targeted ads and marketing \n\nFacebook does it, as do many other devices, mostly from your own phone. Try it out sometime, it's creepy.\n\nI have an android phone for work, logged into my Personal Gmail. A coworker and I were talking about Volkswagen one day at work, when I came home and turned on my Android Sony TV, there was a Volkswagen ad. Tried it over and over with success. Also did this with Facebook on an iPhone, same result. \n\nI have over 10 devices listening to me right now, have had at least 1 (pc) that has been since 1995, that's a lot of audio. \n\nLet's say 1 hour of audio is 20mb (this varies by bit rate and audio quality)\n\nLet's say...\n24 hours is 480mb\n1 week is 3,360mb (3.36gb)\n1 year is 174,720 mb (174.72gb)\n\nThat doesn't seem like much \nMultiply that by (126,220,00 households in the USA alone, and you get 22053.1584 PETA BYTES\nThat's way too much data to extrapolate 24/7 recording. Regardless of what Big Brother does with the audio it swipes off the NSA feeds, Little brother just wants to know if it should advertise you tampons or poopourri.\n\n(That math was a ballpark, if someone has better math, I'd be down to see it.)\n\nTLDR: No one is recording your audio to use against you, although the NSA. has access to a lot of these feeds and can pull audio from them if you are saying \"terrorist phrases\" (thanks Snowden) \n\n",
"The better question is, why doesn’t Alexa recognize when the commercials say, “Alexa?”",
"Why can’t it be “Janis” instead of “Alexa?”",
"Google records before you say \"ok Google\". You can verify by going to your saved voice commands at my _URL_0_. You hear yourself saying the trigger before saying the command.\n\nFilter the products with voice at the bottom."
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2he4gw | whenever i am alone, why does my mind always go straight to making up scenarios where people i love die? | I'm not a depressed person. In fact, I'm very emotionally stable. But for some reason, whenever I am alone, without anything to preoccupy my mind, these thoughts make their way into my head leaving me close to tears. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2he4gw/eli5whenever_i_am_alone_why_does_my_mind_always/ | {
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"My understanding of these experiences is that you are not grounded in the present moment when this is happening. At these times your ego is presenting you with these fictional scenarios to keep you pre-occupied so that you don't notice that your ego is in control of you.\n\nTo stop these scenarios, you have to teach yourself to remain in the present moment, and get out of the habit of drifting off into non-reality and made up scenarios that have never existed. I have found that regular meditation is helpful."
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3henqc | what makes a post a circle jerk? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3henqc/eli5_what_makes_a_post_a_circle_jerk/ | {
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"If a post is completely comprised of like minded individuals just agreeing with each other, it's a circle jerk. So when you downvote someone just because you disagree, you're contributing towards a circlejerk. "
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a0q0ve | type 1a supernova | What is it and how does it happen? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a0q0ve/eli5_type_1a_supernova/ | {
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"Type 1a is a Thermonuclear Supernova. Which usually means that a white dwarve in a double star system is sucking up material from its red giant companion. Usually stars heavy enough to undergo supernova have enough innert iron inside that there is no thermonuclear reaction going on anymore and they collapse from their own weight. They explode from mere physical pressure. A white dwarve however has a lot of carbon instead of iron, which is able to undergo thermonuclear reaction. Thus when the white dwarve sucked up enough matter and got over a certain threashold ( Chandrasekhar threashold, I had to look that one up), then the carbon can undergo fusion and the whole thing explodes.\n\nDuring that process of aggregating that matter, there are several small nova-ish explosions going on all the time when the remaining hydrogen of the red giant fuses while falling toward the white dwarve (or something like that). ",
"White dwarf stars are made mostly of carbon and oxygen, and they're so dense that they're not in a normal state of matter. They are made of what's called \"[degenerate gas](_URL_2_)\" which is more like a solid--it doesn't compress like normal gas does. Imagine that all the atoms are squished together [as tight as they'll go](_URL_1_). That's basically what it is.\n\nNormally this white dwarf is pretty stable. But if more mass keeps being added (like if there's another star nearby that the white dwarf is sucking gas from) then there starts to be a problem.\n\nIf more mass keeps getting added, this will cause the white dwarf to heat up. Eventually some part of it will get hot enough for carbon fusion to begin. This is a big moment.\n\nSo now carbon starts to fuse. Normally this would cause a big explosion, but since the atoms are being squished together so hard by gravity, the white dwarf stays together at first. The fusion produces a LOT of energy, which spreads through the whole star really quickly. Almost instantly, the entire thing starts doing fusion, which *is* enough to blow the star apart. Like, a substantial fraction of ALL the carbon and oxygen in it fuses. So the white dwarf explodes.\n\nBoy does it explode. That's a type Ia supernova.\n\nSome further notes:\n\n* It's pronounced \"1-a\" but it's technically supposed to be written with the roman numeral I. That doesn't really matter though.\n* One noteworthy thing is that this explosion happens at about the same point for all white dwarf stars. So, the explosion puts out the same amount of light every time. This means that we can use type Ia supernovas to [tell how far](_URL_6_) away things are, because we know how much light they should produce, and we can [compare that](_URL_0_) with how bright they look to us.\n* This point at which carbon fusion begins [is called the Chandrasekhar mass](_URL_3_), which is often confused with the related [Chandrasekhar limit](_URL_5_). This is confusing because carbon fusion is determined mostly by temperature, not mass, though adding mass will cause the temperature to increase because of how weird degenerate gas is. The Chandrasekhar limit, by the way, is the maximum mass that a white dwarf could theoretically be, if carbon fusion didn't happen. Making it larger would cause gravity to [compress everything so hard that the atoms would actually break](_URL_4_)."
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68y02h | why do the pages of some books change color after they've been read | The entirety of pages did not change color rather when looking at the books tail while closed there's a distinct difference in color between the read and unread pages. The read pages are darker compared to the unread. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/68y02h/eli5_why_do_the_pages_of_some_books_change_color/ | {
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"I'm not a chemist by any means but it is likely from the oils in your fingers being absorbed into the paper, which is a very fibrous material"
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d652lm | pork rinds are incomplete protein and are labeled "not a good source of protein" but beans are also an incomplete protein and do not have this same label. why? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d652lm/eli5_pork_rinds_are_incomplete_protein_and_are/ | {
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"Because it's not just a question of protien, but of the types of protien and the regulation. In the USA, the Food and Drug Administration requires that food for people aged 4 and over that has, \"a protein quality value that is a protein digestibility-corrected amino acid score of less than 20\" must have the label, \"not a good source of protien.\" What this means is that the foodstuff in question must have a certain number of absorbable proteins or it must have the label. \n\nHow does this relate to beans and pork rinds? Pork rinds are fried pig skins, therefore they're rich in collagen, the protien that gives human skin structure too. Unfortunately, that's about the only protien it provides, worst still humans don't digest nor absorb that protien very efficiently. On the flip side, beans have a wider variety of more easily digested and absorbed proteins so it is not affected by the regulation.\n\nEdit: it's 4 and over, not just 4."
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26waam | dieting when losing weight, dieting when building up muscle | What's there to say, I'm young, I'm chubby, and I'm motivated to turn my life around. I also have around 0 experience with anything but I'll look up exercises and such myself. As you may have already guessed I looked up diets already, but there are a lot of different kinds, each saying something different, and I'm kind of confused.
I'd need a general idea of *what* to eat and *why*, in both cases, the latter case will take a few years until I'm there but it can't hurt to have an explanation already, can it? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26waam/eli5_dieting_when_losing_weight_dieting_when/ | {
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"The best intro guide to fitness imo _URL_0_",
"What to eat: Lean protein (fish, chicken, beef, lamb), fruits and veggies, nuts to start. Cut out soda, or make it an infrequent treat. Try to cut out as much starch as possible, so avoid things like potatoes, rice, bread and pasta. Cut back on dairy products. \n\nWhy: Taking out starches and sugars when possible will drastically cut down how many calories you consume. This will help with the weight loss. Generally speaking, you need to burn 3500 calories to lose a pound. Just existing, your body utilizes about 2000 -3000 calories a day, and generally you'll eat around that much. If you want to lose weight, cut that number down to about 1700 calories a day. As for what to eat, it's pretty obvious. Veggies and fruits will give you the vitamins and other nutrients you need (plus satisfy the sugar cravings), lean protein helps build up muscle, nuts are a good source of protein and good fats. Weight loss is 90% what you eat, so eat well and you will lose weight. Don't be afraid to cheat once in a while (like once in a week), otherwise you'll likely fail. \n\nDon't look at it as a diet, it's gotta a permanent change or you'll go into a cycle of losing a few pounds, and then gaining it back. \n\nAlso start working out. Cardio is important, but lifting is especially good for toning your body. ",
"Dieting to lose weight focuses on creating a *calorie deficit*, meaning your body is burning more calories than it's taking in.\n\nFinding the right amount of calories to eat is fairly straightforward; you find the amount of calories your body burns just to maintain its current weight, called your *basal metabolic rate* or BMR, and then you find out how many calories you're burning through movement (many calculators online can do this for you). \n\nYou try to eat fewer calories than you're burning through BMR + movement.\n\nA pound of fat contains about 3500 calories. If you're burning 2300 calories a day, and you eat only 1800, then you're going to create a 500 cal/day deficit, and after 7 days, you'll have created a deficit of 3500 calories: one pound of fat.\n\nYou can create this deficit in one of three ways: eating fewer calories, burning more calories (exercising), or a combination of the two.\n\nSo for example, you could cut out 500 calories a day. Or you could burn 500 calories per day through exercise. Or you could cut out 300 calories from your diet, and burn an additional 200 through exercise.\n\nYou *can* lose weight simply by altering your diet. It might not be the healthiest way to lose weight (exercise has many benefits), but it's a lot easier to say, \"no,\" to a couple of sodas a day than it is to burn 500 calories through exercise.\n\nTo build muscle, you have to *work* muscle, and consume enough calories to fuel the production of more muscle. There are optimum diets for building muscle, and it's a lot more complicated than an ELI5 comment can get into.\n\nThat said, building muscle while losing weight can actually help you burn fat *faster* - you put on weight with the muscle, and that added weight raises your BMR, which is your minimum amount of calories burned per day."
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jdwif | supply and demand in relation to markets with infinite supply (downloads). | I'm interested specifically in the pricing of units when a company or industry need not worry about production. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jdwif/eli5_supply_and_demand_in_relation_to_markets/ | {
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"By pricing it at a certain amount, you effectively limit supply. At $0, you can \"sell\" the maximum amount of units, and every increase in price theoretically reduces sales. The key for the seller is to find the price at which (price times sales) will equal the greatest amount. None of this takes into consideration the \"value\" of marketing - it may be easier to sell a digital good at $10 than at $1, simply because at $1, it may be seen as less valuable by the customer, and may be more difficult to market online.\n\nIf this sounds different than classical supply and demand, it's because that simplified market explanation is actually *too* simple in most cases.",
"By pricing it at a certain amount, you effectively limit supply. At $0, you can \"sell\" the maximum amount of units, and every increase in price theoretically reduces sales. The key for the seller is to find the price at which (price times sales) will equal the greatest amount. None of this takes into consideration the \"value\" of marketing - it may be easier to sell a digital good at $10 than at $1, simply because at $1, it may be seen as less valuable by the customer, and may be more difficult to market online.\n\nIf this sounds different than classical supply and demand, it's because that simplified market explanation is actually *too* simple in most cases."
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3njtwz | how is gun control not a good idea? | I'm a Brit, and from my perspective it's astonishing that in the U.S further gun controls haven't been put in place yet. I can't see what might be the argument against a licensing model for weapons like we have in the UK, but the counter arguments must exist - and must be pretty good to withstand the general outcry following the periodical mass shootings.
Could someone ELI5 the general 'gun control legislation' climate in the U.S? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3njtwz/eli5_how_is_gun_control_not_a_good_idea/ | {
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"The general idea is that criminals and terrorists don't care about laws anyway, and so will buy a gun on the black market.\n\nGiven that the bad guy has a gun, why not allow the good guys to have them as well?",
"Basically, the counter rationale falls into two camps:\n\n* Giving the government the right to control who does and doesn't have guns means resisting government oppression is harder.\n* Making it harder to get guns means less people can defend themselves.\n\nNote: this is not an opinionated piece, just common arguments I've heard.",
"It might be strange to a foreigner, and certainly to many Americans as well, but Gun Rights aren't 'given' to us, they're 'protected'. It is a contract between the people of the United States, and the US Government, that the Government will not disarm the population or the militia. States define Militia differently, however, such as Texas considering every male aged 17-45 part of the Unorganized Militia, and are expected to uphold peace and repel invasion. The Federal government considers the Militia to be the State's National Guard. There are also several non-government militias who despite having radical ideology, are completely legal as it is protected by the 2nd Amendment. The Government is required to treat every man woman and child equal. What this means is that if Person A is allowed to have a gun, Person B is also allowed to have a gun. Every person is, by our natural rights, allowed to have a gun. Thats where the confusion starts, as \"every person\" means the mentally ill and the criminally minded. Most states ban Criminals from having guns. The mentally ill can, however, own guns in many states, not all, but still quite a few.\n\nPeople say that guns are a \"part of our culture and should be protected,\" and they are, but thats not the reason why. They also say \"the bad guys have em' so should the good guys\" which, in all honesty, isn't that great of a defense. The resisting the government one comes to mind, but the opposition to that one refuse to hear it at all, often saying \"OMG UR NOT EVN GONNA B ABLE 2 DEFND URSELV\" despite there being 100 million people who own guns, airplanes, boats, and vehicles who would at any given moment use them to defend themselves. No, the main protectorate against gun control is the contract between the Government and The People stating that they will not, at any time, take the Arms away from the People.\n\nAnother point they say is \"ummm they had MUSKETS!\"\n\nWell, it doesn't say \"muskets,\" it says \"arms.\" Note the language.\n\nAlso, when it comes to statistics, states with more guns tend to have less violent gun crime.",
"Well, first, you have to understand why the Constitution protects our right to own guns. It isn't for hunting or defending ourselves from a criminal (though those are nice benefits). Our right to bear arms is protected by the Constitution specifically because our country wouldn't exist without them. The founders of our country used guns to fight for their freedom against the tyrannical government, and they wanted the citizens to be able to do the same if the government they set up ever became that bad. This can also be seen in the wording of the Declaration of Independence.\n\nBut most people don't think about that. So why are people opposed to it? Equality and protection. A criminal will get a gun anyway. Even if guns were forcibly taken from every citizen and it was illegal for anyone except police and military to own them, criminals would still find a way to get a gun. They may buy one from another country and smuggle it. They may steal one from a police officer. They may kill an officer and take their gun. They may even make one (yes, it's possible, but dangerous). Criminals will still obtain guns. If a criminal has a gun but you don't, your only option is to do what they want. If they just want to kill you, you're dead.\n\nNow, of course, making all guns illegal is an extreme example and won't be happening any time soon, if at all. Nobody is pushing for that. But it makes it easier to understand what would happen if guns were controlled more strictly.\n\nGuns are already a pain in the ass to get. Background checks, permits, and registration are all required in certain states, and most states require at least one of these things. I don't know of a single state you can legally get a gun without a background check. Adding more hoops to jump through makes it harder to legally get a gun, which deters law-abiding citizens from doing so. Some who have no intention of committing crimes with the gun will get them illegally, but most just won't get them. But a criminal doesn't care. They will obtain a gun illegally, just like they would if guns were banned outright. Then the law-abiding citizens are in the same boat as my earlier example. They are screwed.\n\n",
"Part of the problem is the demand for gun control generally peaks around periodic mass shootings. It then immediately puts all gun owners on the defensive because the media is declaring that it's the fault of those with guns that this happened. It's also irritating because it takes away all personal accountability of the shooter and off of the substandard American mental health system and stigma against getting help.\n\nImagine if a person with a van kidnaps a kid so regulation is created to force van purchasers to go through several extra phases of checks to purchase one. It definitely feels like all van owners are being treated like kidnappers and all future van owners will be treated like kidnappers...all for the protection of children of course. So now whenever a kid is kidnapped the cops come knocking at your door to see where you were.\n\nNow, another thing you need to understand about our country is we have almost zero faith in our government. In fact, the only thing I really have faith in our country to do is fuck things up, hurt innocent people, and over punish people for insignificant crimes. I have faith that our police will arrest kids because they're too afraid to go after real murderers. I have faith that our DA will push prosecution on innocent people simply because they know they can win. I have faith that our prison system will abuse and warp that person's mind. And I have faith that by the time they exit if they weren't criminals before...they will be now.\n\nOnce you combine the idea of being treated like a criminal and essentially registering as a potential criminal with distrust of our police, legal, and political system...it should be obvious why we're concerned whenever somebody tries to control guns.\n\nPersonally, I don't understand how the rest of the world can trust their governments as much as they do. Must be nice to have officials that you feel are looking out for your best interest rather than theirs."
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26ke7d | how do astronomers describe the location of objects (stars and spacecraft) in the universe? | For example, when using a telescope, how do they store the "coordinates" of where to look? Is the same system used when describing the position of spacecraft? Or do they use another method to describe where in the Universe (solar system) they are located? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26ke7d/eli5_how_do_astronomers_describe_the_location_of/ | {
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"Astronomers use whats called the Celestial Coordinate System, which is made up of 2 components: Right Ascension and Declination.\n\nRight Ascension is the equivalent of projecting the earths lines of longitude onto the sky, and Declination is latitude. By giving those 2 numbers you can point to a particular point in the sky. Then, by giving a range such as 5.5 Astronomical Units, or 45 light years, or something like that, you can arrive at a particular spot in the universe. "
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9d5u9w | whats the difference between compact bones and spongy bones? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9d5u9w/eli5_whats_the_difference_between_compact_bones/ | {
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"Compact bone is found around the shaft of long bones and is made of concentric rings of bone with no red marrow between it. It is strong against compression and within it contains the marrow cavity with bone marrow in it. \n\nSpongy bone is found within the heads of the long bones, and in flat and irregular bones. Instead of concentric rings, they have bony shelves in a spongy meshwork called trabeculae and red marrow surrounding it. It is weaker to stress than compact bone. "
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5wwwv4 | how did people maintain and change hairstyles before barber shops were widespread? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5wwwv4/eli5_how_did_people_maintain_and_change/ | {
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"Barbers are an exceptionally old profession, even if they were travelers, and not necessarily setting up proper shops.\n\nNote that Barbers also served more roles than just cutting hair. Because of the tools at their disposal, they were also called on for minor medical procedures, like lancing boils (they had really sharp blades, and bacteria weren't generally known of). In fact, proper \"barbers\" are pretty rare any more, as they have been mostly replaced with cosmetologists.\n\nHowever, if you want to adress pre-barber times, or areas where barbers didn't frequent, people just did it themselves or asked a friend/neighbor/spouse to do it.",
"As a rule, they didn't change hairstyles.\n\nIf you didn't have access to a barber, you were probably poor and lived somewhere remote. You let your hair grow, and either cut it yourself, or had a friend or family member do it for you.\n\nYou likely didn't have access to cosmetics, either, so styling would be pretty simple. You would not have time for anything too elaborate."
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3jbzf5 | what are the benefits of using premium unleaded fuel in my car? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3jbzf5/eli5_what_are_the_benefits_of_using_premium/ | {
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"Don't do it. Unless you have a car that requires knock-proof high octane fuel, such as a car with a high boost pressure turbo or a high compression naturally aspirated engine, there's no benefit. Don't buy into the marketing malarkey. \n\nBasically, if you car needs premium to run, by all means only ever get premium. If your car runs on regular, there's no advantage to wasting premium on it - especially the old 'I'll fill it with premium every now and then', which even in the off chance that your ECU would be able to adapt and draw benefits from the new fuel, doesn't give it enough time to do that before it's time to readjust to the inferior fuel."
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3bgdpi | why can't spacex do what has been done so many times before? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3bgdpi/eli5_why_cant_spacex_do_what_has_been_done_so/ | {
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"They are using a new rocket design. This is their first major failure, which is a huge success in and of itself. Even NASA and other government space agencies still have problems getting things into orbit, which is no small feat. You have to remember that our method for getting things into space involved creating a huge explosion, hoping it doesn't destroy your cargo, and riding that explosion into space. It is much much much different, and more difficult, than just launching a missile in atmosphere. There are insane challenges and SpaceX has already done some great things, although its track record is rough in some spots and it is far from perfect.\n\nAnd yes, reusing rockets is a huge game changer. It is incredibly expensive to build new rockets each time you need to launch. With SpaceX's design you can land, refuel and add cargo and take off again. Its is a major leap forward if they can get it to work. ",
"This is the first failure of a SpaceX rocket. The other failures we're the first stages attempting to land, which has never been done before. I have no idea who is telling you every SpaceX launch has failed but they are lying.",
"Have you ever heard the expression \"it's not rocket science!\" ?\n\nWell, this is rocket science. It's fucking hard.\n\nSpaceX have been a stunning success. I'm actually gob-smacked that you somehow think you can look down on them.\n\n ",
"Elon Musk said, their rocket and others costs as much as a Boeing 747. You don't see a 747 thrown out after each launch, so why should rockets? It will lower the price of sending stuff to space. \n\nSo why did it blow up? They started with a ground up design from it, trying to make it reusable and tweaking it along the way. One of the landing legs could have malfunctioned blowing it up, etc. \n\nSuccess is not without failure. What amazes me the most is this is the first time their resupply craft blew up. \n\nPerspective, a Russian resupply mission a few months ago blew up using tech they've been using for decades. "
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3eo0g1 | what keeps dogs from jumping out of open car windows at stop lights, stop signs, etc.? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eo0g1/eli5_what_keeps_dogs_from_jumping_out_of_open_car/ | {
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"In my experience? Doggie seat belts.\nOne of my pups jumped out of my car going 40mph because she saw a horse. If dogs find a reason to evacuate a car, they will.",
"Nothing. It happens more than you think, and the owners are usually to stupid and upset to do anything for themselves. I once saw a little fluff ball jump out and started walking in the opposite direction (probably going back home). I stopped, got out and down on one knee and the little guy came right to me. I gave him back to the owner who just put him on her lap and drove off."
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eu3xei | why is dj khaled considered a musical artist? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/eu3xei/eli5_why_is_dj_khaled_considered_a_musical_artist/ | {
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"I think he might make the beats?",
"If he’s on the decks, mixing tunes then he’s a DJ. If he’s on the mic shouting or rapping then he’s an MC, or just a Hype Man",
"He primarily facilitates the \"right\" artists coming together on a track. He used to be more of a producer before, but now it is mainly the facilitating.",
"Reminds me of that family guy where Pitbull(a similar \"artist\") says he's off to Vegas to make bank for shouting \"make some noise!\"",
"To understand why he is famous, it would be more important to know where he came from and the progress of hip-hop and I guess the music industry in general.\n\nRight up to maybe as recently as 6 to 8 years ago, \"mixtapes\" and getting your song played by DJs both on radio and in clubs, was the equivalent of going viral on the internet and becoming famous as a rapper or even a producer. \n\nSo especially during the 2000s, Khaled and other radio/mixtape DJs (some names you might have heard: DJ Clue, DJ Drama, DJ Whookid, Funkmaster Flex, The LA Leakers) became a sort of the gatekeepers of what rappers and songs were hot. By getting songs first from the already established popular rappers, they would increase their own profile and listener base which would make new rappers/producers want to get their music on these DJ's mixtapes and radio shows. These DJs would release their mixtapes and it would contain freestyles, first listens and exclusive songs from a variety of artists. Basically, the DJ's own playlist.\n\nSo what Khaled does right now is an extension of that - he gets artists that are \"hot\" together on songs and releases those songs on his albums which are just more refined versions of what mixtapes used to be.",
"He's essentially the manager. Pays money for all the worker. The beat makers, the producers, the artists etc..\n\nHe doesn't make the beats. You can hear it in many songs where either the producer or the beat makers tag will appear. \n\nHe's stated on interviews his essential job is taking the risk. Which has payed off in some fashion.\n\nUltimately he used to DJ when he was younger on an early interview you can see him talk about it. But i dont know where that ever went",
"I just finished watching the Sinatra spectacular from 65 on YouTube where Sammy Davis Jr. sings an incredible piece accompanied only by drums that blew me away. He dances and does some comedy, then some impressions. All impeccable. I find it difficult to bring myself to mention this DJ by name in the same sentence as Sammy Davis, even when doing it specifically to point out the unfathomably vast disparity of talent between them. I don’t know what this DJ should be called, but I call him untalented.",
"Better question.. WHO is DJ Khaled?",
"we were talking about this at work the other day, I have only seen him yelling his name also lol."
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36dww8 | what is happening in my mouth when i whistle? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/36dww8/eli5_what_is_happening_in_my_mouth_when_i_whistle/ | {
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"You're pushing air past your lips, and the shape of your lips is vibrating the air as it passes by (similar to how your vocal chords vibrating make the sound of your voice on the air).\n\nWhen air is forced through a constricted area, it will vibrate when it hits a surface (which is why when it's windy outside, you can hear the wind whistling through the attic or some other enclosed space)."
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8rdew6 | why does reggae music seem to mention zion and babylon a lot? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8rdew6/eli5_why_does_reggae_music_seem_to_mention_zion/ | {
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"Reggae is closely tied to the Rastafarian religion. Babylon represents the evils of modern society & oppression while Zion represents the promised land to which they want to escape.",
"Rastafarian is basically Judaism for Jamaicans. So they have a lot of the same religious symbols like mount Zion. If I remember correctly strict Rastafarians don't eat pork either. \n\nIn my opinion reggae is the best religious music out there. ",
"Zion and Babylon are symbolic. Given that reggae music in itself is religious, Zion symbolizes the promised land while Babylon symbolizes unrighteousness and moral corruption; analogous to Christianity. ",
"TL;DR: The reason that you hear these terms in Reggae a lot is because so many of the practitioners of the music are of the Rastafari belief system.\n\nJoe Higgs is considered the father of reggae by many people, as he started Bob Marley and the Wailers, Bunny Livingston, Peter Tosh, Jimmy Cliff, and more.\n\nBack at that point, many of the original Reggae players (Reggae was quickly dividing into 4 sub-genres) were of the Rastafarian belief.\n\nIn the Rastafari belief system, god is referred to as \"Jah\" (likely from Jehovah), which is why you hear Jah a lot. Now, since Rastafarianism originated in Africa, many times \"Zion\" is referring to Africa. But to many Reggae performers (particularly those in Africa) Zion is only the holy group of Rastafari, and specifically those in Africa. Additionally, in groups such as the Reggae musicians mostly living in Jamaica, Zion refers to all Rastafari, both in Jamaica, Africa, and sometimes all over the world. Sometimes these more liberal Reggae musicians will accept a wider range of African descended people into their definition of \"Zion\", even if they aren't Rastafarians. This all becomes more important when you talk about Babylon.\n\n\"Babylon\" Is mostly a term used to refer to the entirety of the world that is not Zion. So based on the definitions of \"Zion\" that the different groups have, the definition of \"Babylon\" can change drastically. For example, some Rastafari groups simply refer to all white people as Babylon, while some may just call anyone who is not Rastafari \"crazy bald-heads\". There is varying degrees of militarism in the different Rastafari groups, with some being outright armed and violent, and some being entirely peaceful.\n\nAt the end of the day, the reason that you hear these terms in Reggae a lot is because so many of the practitioners of the music are of the Rastafari belief system. \n",
"The people pointing out Rastafarian roots are correct, but I think it is easier to focus on these specific reference.\n\nBabylon: In the Bible, Babylon defeats the Jewish kings and takes some of them prisoner in the city. For the Caribbean communities that are tied to reggae and Rastafarianism, Babylon is the place of their captivity ... basically the Americas.\n\nZion: In the Bible, Zion is Jerusalem, the home promised to the Jews by God. Likewise, for the reggae singers, Zion generally refers to Africa, the home that their ancestors were taken from as slaves.\n\nYou can add a lot of little details, but that is the basic idea for a lot of the references. ",
"Reggae music is pan african music. Made for Africans who don't live there, but profress a desire to repatriate.\n\nAt its core reggae music is a spiritual and political artform.\n\nWhen Marcus Garvey spoke of a black king come to bring black men together and usher in a new period of peace on earth, the early rastamen and women truly believed, and worshipped Haille Selassie H. I. M. As the second coming of christ.\n\nWhere he was, was paradise. The result of their prayers and devotion led to the establishment of sheshemane. Land devoted to renaturalised rastamen and women.\n\nThose who stay are living physically and spiritually in babalon. We are slaves to sin, oppression, and discrimination.\n\nThose in Africa, with a specific focus on Ethiopia (where the conquering lion of juda was born) are said to be living in Zion. A promised land of peace milk and honey.\n\nReggae is a cool artform man, and when you believe and understand aspects of the spiritual and political messages, it takes on a whole new look. ",
"He was still alive while being worshiped, I’m almost certain he said something about it being awkward."
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4k0079 | how can i safely stick my hand in a 400 degree oven, but get burned in a 212 degree pot of water? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4k0079/eli5_how_can_i_safely_stick_my_hand_in_a_400/ | {
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"It's all about surface contact.\n\nSo when your hand goes into the water, basically every little bit of your hand is in contact with really hot stuff (hot water).\n\nAir is a lot less dense than water so when your hand is in the hotter oven there are far fewer atoms in contact with your hand.\n\nHeat transfers by (basically) atoms bouncing into other atoms. The hotter those atoms are the harder they bounce. So even though the water is less hot, there are far more atoms bouncing around so more heat is actually transferred.",
"Air and water have very different \"specific heats\". This term refers to how much thermal energy they have to absorb to raise a degree in temperature. It take an large amount of energy to raise water's temperature. It takes a small amount of energy to raise air's temperature. Now flip this scenario around. Put your hand in an oven's hot air and your hand starts absorbing thermal energy from the air. Because of air's low \"specific heat\" the air's temperature immediately surrounding your hand falls quickly, fast enough that it cools before you burn. Put your hand in boiling water and your hand starts absorbing thermal energy from the water. Because of water's high \"specific heat\" it's temperature stays roughly constant as your hand absorbs its energy. The water stays hot enough long enough to burn you.",
"The proper term is thermal conductivity with the units of W / (m K) (Watts / meter Kelvin).\n\nAir has a low thermal conductivity. We use air as an insulator. Insulation (the pink stuff in the walls) works, because it stops air from moving around. Air naturally does not conduct heat well, but it is easy to move it around. The pink fiberglass keeps its from moving around.\n\nWater have a much higher thermal conductivity. Metals are even higher. If you touched the walls of the 400 degrees oven, that would be an instant burn.\n\nList of thermal conductivity for some materials here: _URL_0_",
"Its not temperature that burns you, its heat and energy. Air at 400 degrees has less energy than water at 212. The other reason is that air has less balls hitting your skin to transfer heat than water does. Balls are molecules. The density of air plus the electrostatic effects that causes water to stick to you means that water has a greater potential to burn you at similar heat loads than air."
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5utqb4 | why does light need to consist of particles to explain the photo effect? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5utqb4/eli5_why_does_light_need_to_consist_of_particles/ | {
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"We know from the wave picture of light that there are two ways you can increase the energy you are delivering to a system if you shine light on it. You can either:\n\n* Increase the amplitude of the light wave i.e. the height of the wave, making it brighter.\n\n* Increase the frequency, i.e. the number of wave peaks packed into a certain time period, shifting the colour. \n\nNow, when you shine light on the surfaces of certain metals, you can liberate electrons. What you find is that you will only see a photocurrent (current of electrons liberated by light) above a certain frequency of light, unique to each metal. As you turn up the frequency, the number of electrons reaching your collector will increase. But, importantly, the same effect is not observed if you increase the intensity of the light. \n\nSo what are our observations? \n\n* There is a minimum frequency of light required for electrons to be liberated, and therefore a minimum energy. \n\n* Turning up the frequency increases the number of electrons we detect. \n\n* Changing the intensity has no effect on the observation of electrons. This means the energy has to be delivered to the electrons all in one go. \n\nThe only logical conclusion is that the light must be delivering energy to the electrons in discrete packets, or quanta, to push them out of the metal, and that the energy of each packet is proportional to the frequency. When one of these packets, which we call a photon, hits the electron, it delivers it its energy, which will free it from the metal if it's enough. Any excess will be given as kinetic energy, meaning faster moving electrons that can travel further and hence more will reach our collector. \n\nThe photoelectric effect is fundamentally inexplicable by the wave nature of light, and the particle nature is the simplest explanation which turns out to also give us views into a whole world of other phenomena related to quantum mechanics. Indeed, QM gets its name from quanta, which refers to discreteness. ",
"The photoelectric effect happens when an electron gains enough energy to break free from an atom, so the effect can be observed by measuring the current. If light were a wave, you would expect that increasing the intensity of the light would cause a current, even if the light is low energy. This is because you would expect that once enough of the low energy waves are absorbed, the electron will have enough energy to escape. What actually happens is that there is NO current for light below a certain energy, regardless of the intensity (ie. number of photons) because the electron must get all the energy it needs from a single photon. "
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22n2sm | how can cops prove you were speeding? | Didn't know how to word the title; but my question is if you were to take a speeding ticket to court how would a cop prove that you were speeding? Do speed trackers take pictures/record when they are pointed at your car? Or would it just be the officers word against yours? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22n2sm/eli5how_can_cops_prove_you_were_speeding/ | {
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"1 - The radars keep track of all measurements, they just have to show the measurement from when they pulled you over\n\n2 - Dashcams can also include the speedometer that shows that in order to keep up to you, they had to speed\n\n3 - Yes, it comes down to a cop who has no legit reason to lie about you speeding's word against yours."
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26aoa5 | (usa) if you're 16 and can work - why can't you vote? | Always been curious. Isn't that taxation w/o representation? They are able to work and earn a paycheck and their wages get taxed, but they get no say in where their tax money goes? Help me out here... | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26aoa5/eli5usa_if_youre_16_and_can_work_why_cant_you_vote/ | {
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"\"Taxation without representation\" was a slogan during the Revolutionary War. It's not a law or anything."
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[]
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|
848r9a | how to live studio audiences work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/848r9a/eli5_how_to_live_studio_audiences_work/ | {
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"The sets are all right next to each other, usually lined up in a row or set up across from each other in a large studio. The most common sets (so for Friends it would be Central Perk, Monica's apartment, and Joey's apartment) will usually be right next to each other to make things easy on the cast and crew. Temporary sets (a girlfriend's apartment, a character's work, etc) are usually built wherever there's room in the studio.\n\nThey'll typically film the entire episode more-or-less in chronological order, doing additional takes as necessary for each scene. The audience seats are lined up facing the sets. Depending on the size of the audience, they'll either get up and move over when the cast and crew moves so that they can sit right in front of the action (smaller audiences) or they'll watch on monitors if the room is too crowded to move everyone, or if the closer seats are also filled. \n\nOutside scenes or any extra shots outside of those main sets are usually filmed separately and before everything else. They're played on the monitors for the audience while the cast and crew set up the next scene, so that their laughter can be recorded and so that they can follow the story.\n\nSource: a few trips through the WB studio tour and walkthroughs of their sitcom studios."
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||
awmzp6 | why do ncaa basketball players wear arm sleeves and white tights? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/awmzp6/eli5_why_do_ncaa_basketball_players_wear_arm/ | {
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"Compression sleeves. Its supposed to increase blood flow and reduce recuperation time.\n\nBut really they just want to look like Allen Iverson",
"Look good, feel good , play good.\n\nAlso from my experiences it helps combat calf cramping and some are padded.\n\nAlso bigs regularly get theirs arms scratched up a bunch going for boards so the sleeves offer some protection."
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bt7eff | why does alcohol stop tasting like alcohol when you're drunk? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bt7eff/eli5_why_does_alcohol_stop_tasting_like_alcohol/ | {
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"Alcohol is a depressant to your nervous system so it dulls all your senses. Similar to if you bump into something while drunk, you don’t feel it until the next day, or why your vision gets blurry while drinking.",
"When you're drunk, even your breath tastes strongly of alcohol (it comes out of your blood when you breathe). When humans feel a constant sensory input, our brains eventually start blocking it out ([Neural adaptation](_URL_0_)). \n\nSo because our mouths constantly taste of alcohol, we can't taste alcohol as well. It's the same reason smelly people can't smell their own BO.",
"Related question: When I was a kid, whisky made me shudder and tasted like medicine. Now, it tastes like sugary water. What happened?"
]
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xaqts | the visual acuity aka 20/20 system | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/xaqts/eli5_the_visual_acuity_aka_2020_system/ | {
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"This is the way it was explained to me (And I may need to go check my facts). \nImagine someone is standing 20 feet away from a wall. Someone with 20/20 vision will be able to clearly read text written in letters that are 20 inches tall. 20/40 would be someone who needs text 40 inches all.\n\n**EDIT:**\nI *was* in fact wrong.\n\n\"If you have 20/20 vision, it means that when you stand 20 feet away from the chart you can see what the \"normal\" human being can see. (In metric, the standard is 6 meters and it's called 6/6 vision). In other words, your vision is \"normal\" -- most people can see what you see at 20 feet. (From here on, please assume that the word \"normal\" has quotes around it).\nIf you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what a normal human can see when standing 40 feet from the chart. That is, if there is a normal person standing 40 feet away from the chart and you are standing only 20 feet away from it, you and the normal person can see the same detail. 20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States.\nYou can also have vision that is better than the norm. A person with 20/10 vision can see at 20 feet what a normal person can see when standing 10 feet away from the chart.\"\n\n[Source Here](_URL_0_)"
]
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1ivymm | supernovae, neutron stars, and black holes. | What causes each one to happen, How are each possible, and different from each other? It seems like they all occur due to gravity, but how doesn't a neutron star form a black hole? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ivymm/eli5_supernovae_neutron_stars_and_black_holes/ | {
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"Suns come in different sizes from dwarf to super giants. The reactions in the center of a sun's core is crushing atoms together till they transition to different elements. A sun begins to go super nova when the core reaches iron production. At this state, the center can absorb and retain energy causing the start to die almost instantly. At the point of super nova, the sun explodes violently and the formation of elements such as gold and platinum are shot out across the cosmos. If the star is large enough, it leaves behind a neutron star, incredibly dense matter. A teaspoon of which weighs around 100,000 tons. Black holes form when a super massive star begins to die, the reaction reaches a point where the exploding energy can't escape the gravity generated by the center of the star and it becomes a singularity. Neutron stars don't have enough gravitational force to become a black hole, as the particles that are pulled back by gravity escape the star's poles as a gamma ray burst.",
"[Carl can explain this better than any of us is likely to.](_URL_0_)\n\nDon't worry, you don't need to watch the whole hour - just the couple of minutes after where I linked to here.",
"* **Supernova**: when a massive star blows up, initiated by the sudden (takes less than a second) collapse of it's core. The collapse of the core is initiated when the pressure from nuclear fusion can no longer hold up against the immense gravity pushing in. There are generally two types, Ia and II.\n* **Neutron Star**: a super-massive and super-dense star where all the space between the the neutrons and electrons of the atoms of the star has been eliminated. In other words, the atoms have been crushed so there is virtually no space between the neutrons and electrons. A teaspoon of neutron star would weight millions and millions of pounds.\n* **Black holes**: when a super-massive star's core collapses all the way down to a singularity, an infinitely dense and infinitely small point. Bends space-time so much that not even light can escape it's gravitational pull. If you get close enough (called the event-horizon), you will never be able to escape the black hole's pull.\n",
"I have a relevant question... Is it possible that a death of star could have occurred a really really long time ago, but our satellites only pick it up now because of how long it takes the light to reach earth? Is it possible that many of the stars we see in the sky might be dead now and he just see them because of how long it takes for light to reach? Is it possible that there is no star in existence at all? And that they could all be dead? But again... Light?",
"Firstly our sun is a star and everything starts from here. Have you seen an explosion before? Well, this is essentially what a star is: lots of heated stuff flying away from where the explosion was started. In space a sun is a very long lasting explosion that keeps going because there is so much stuff to explode. The sun doesn't explode past a certain size due to a force called gravity. Without going into do much depth gravity is what holds planets and stars together and squishes everything in them towards the middle. The bigger they are the harder this squeeze is. \n\nIf you notice when an explosion on earth finishes it gets smaller and looks to fall back to earth. It is gravity that causes this to happen and this is very similar to what happens when a sun supernovas. It's the explodable stuff within a star that exploding that stops all of the stuff in a star from being taken over by gravity and being crushed into a little ball. Once this explodable stuff is used up this is exactly what begins to happen. Gravity takes over quickly and the ball that is the star compresses into a small space very quickly. \n\nHowever, this raises an interesting question: why does the star then explode? Well, think of it that a star is made up of lots of little springs. There is only so far you can squeeze them together quickly before they rebound. The more and faster you squeeze, the harder it seems to hold the spring in place. Try squeeze on a spring really fast and you will see what I mean. The spring in the context of our star is the force that holds the electron away from the protons and neutrons that it orbit. So that explains the supernova.\n\nBut what about a neutron star. Imagine gravity was strong enough to hold the all of the springs together as close as they can be, with so many springs there is going to be a lot of force wanting to spring out in this situation. What you end up with is a very fast spinning tight and powerful mix of springs. With all this force within springs can be violently ejected from the north and south pole of this violent spinning beast. In the context of atoms all the space between the protons, nutrons and electrons is squished as far as they can be together and gravity is strong enough to mostly keep them there.\n\nBlack holes are where it gets really weird. You see gravity also bends space. Go into your bedroom and with a few friends pull a bed sheet taught and put a football (soccer ball) onto it. You will notice the sheet gradually dips in to accommodate for the football. Now if you were to roll a marball along the sheet you would see it follow the curve that has been created in this sheet. This is pretty much how gravity works in space and is why our moon orbits our sun. But why does this relate to a black hole? Imagine you had a really heavy metal ball-bearing and this time you stretched out some cling film to put it on. The well created by the ball would become so deep that if you rolled the marball too close the it would almost always fall into the well that the ball sits in. This is exactly what happens with a black hole and the point where it is impossible to roll through that is furthest away from the ball is something called its event horizon. We don't actually know what it is like past this point as its well is so deep that not even light is able to escape it. There are lots of theories which I think could take a lot of time to talk about in themselves so we shall leave this for another bedtime story. *tucks in*\n",
"First of all, one of those are not like the others. Supernovae, unlike neutron stars and black holes, are not celestial objects, but an event that last for a few days. Neutron stars and black holes are the outcome of a supernova.\n\nAfter the hydrogen, which is the fuel that every star burns during most of its life, is almost depleted and the energy generated by the star no longer prevents the whole mass from collapsing, two things might occur:\n\n- If the star is not very massive, the atoms inside can still remain intact, thanks to something called electron degeneracy. Electron, neutrons and protons belong to a type of particles called fermions which, unlike bosons, can't occupy the same space with the same energy. That's what prevent the atoms from being destroyed. The final state of the star is then a white dwarf.\n\n- If the star is massive enough, the collapse is stronger than the electron degeneracy, and the atoms are crushed in the core. What happens is a big emission of matter (containing heavier elements, like carbon, iron and nitrogen) and radiation to outer space. That's a supernova. Once again, two things might occur to the core:\na) If the collapse is not stronger than the quantum degeneracy pressure (the degeneracy of quarks, the constituents of the neutrons and protons), the atoms are crushed but not their nuclei. The core becomes a huge atomic nucleus, consisting only of neutrons. The protons absorb the electrons that were present becoming neutral as well. That's a neutron star. It is very dense; the sun mass would fit in a sphere of just 20 km radius.\nb) If the collapse is strong enough, no force in nature can suppress it. It collapses infinitely, creating a black hole. It becomes so dense that even light can't avoid falling inside, generating a region completely dark, called event horizon. From inside this horizon nothing can escape, since nothing can be faster than light. "
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67yc3o | what the difference is between a galaxy, a cluster, and a galaxy cluster. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/67yc3o/eli5_what_the_difference_is_between_a_galaxy_a/ | {
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"Cluster: Quite a few star systems close together Galaxy: Lots of stars orbiting a black hole \nGalaxy cluster: Same as cluster but with galaxies"
]
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||
8z0jpx | why do luxury car companies change their designs much less frequently than more standard car companies? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8z0jpx/eli5_why_do_luxury_car_companies_change_their/ | {
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"If you have a goose that lays golden eggs, why change it for a duck that lays normal eggs?",
"For some companies, the design is part of the brand. I know it is not a car but think of Apple products (IPhone etc.) - they all have this distinct Apple design vibe going on, so they are easy to be recognized as Apple products by consumers. As luxury car companies, they appeal to a certain customer group and their products are expensive - not everyone should be able to have one, and these who do should feel 'special'. Standard car companies try to sell to a much wider and broader customer group (e.g. to all of us) and thus try to design their products to appeal many different people. They change designs frequently to 'go with trends', which are subject to change.",
"It helps sell the brand. It's a image. If you change it up people aren't going to know what it is. And people who drive those cars want people to know what they driving."
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ce0w55 | why do women have periods for 3-7 days, why can’t it just all bleed out at once? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ce0w55/eli5_why_do_women_have_periods_for_37_days_why/ | {
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"Period is uterine lining being disposed of from the body (this is not exactly blood). The purpose of the uterine lining is used to grow a baby in the womb. When the egg is released monthly and and not fertilized, the body gets rid of everything it would have been using to grow a baby. It’s not possible for it to happen all at once because the eggs and cannot be ready for fertilization all at once, and thus discarded all at once if not in use."
]
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||
aivh0a | how do states like texas, florida and nevada have no state income taxes and survive ? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aivh0a/eli5_how_do_states_like_texas_florida_and_nevada/ | {
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"Lots of property taxes and business taxes. There are many ways for state government to get money, it doesn't have to be income tax.",
"Texan here, the Texas constitution outlaws personal income tax, so the lost revenue is generated from higher sales and property taxes, but these higher taxes are generally in more populous counties, so people living in rural areas generally exercise really cheap living.",
"Texas is actually prohibited by their state constitution to have personal income tax -- but don't worry, they simply increase the sales tax and property tax (one of the highest in the nation) to compensate!\n\nFlorida has a high sales tax and property tax as well. Personal income taxes were eliminated there long ago (1850s?), but like Texas, the other taxes make up for it.\n\nNevada gets a massive influx of cash from the gaming industry to offset not getting personal income taxes, but also has a substantial sales tax too.\n\nA personal income tax is just one way to tax -- these states still get their money, just through other taxes or means.",
"Texas has its Franchise tax (business tax), sales and uses taxes, and property taxes, plus many other taxes like motor vehicles, natural gas, etc. Some of these options are probably similar to tax schemes in states with income tax. However, tax rates are different.\nOne random example -\nTexas state sales tax: 6.25%\nCalifornia state sales tax: 6%\n\nMore info -\n[Texas Comptroller ](_URL_0_) ",
"Florida relies on tourism! Basically we tax everyone that comes here. If you’ve ever looked at hotel bills there are usually extra tax categories thrown in. ",
"Florida also has a state sales tax and a tourism tax that bring in a good amount of revenue. ",
"In Texas: Property taxes, sales tax on goods, and other random taxes. The property tax increases are kind of insane the last few years; I’m not a big fan at all. "
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a5xr12 | why are more developed countires less religious (think western europe , japan etc) whereas poorer countries tend to be more religious. if religion is equally "free" what explains this? | What explains the difference in religious affinity between Rich and poor parts of the world. Why are poor regions more ferverent and religious? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a5xr12/eli5_why_are_more_developed_countires_less/ | {
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"A greater level of ignorance around scientific phenomena, and general supression of women often co incide with poor religious countries. \n\nYou can't claim god makes the tide come in and out when the moon and laws of gravity were explained in grade school. \n Keeping women out of schools prevents half of the population from being immunized against that level of ignorance.\n\nProvided one has been prepared from birth to accept the tenets of religion as unfailingly true, the faith would probably bring comfort to someome who's life would otherwise be miserable. They \"know\" they will receive a benefit of some kind next time round, so it is much easier to accept that this time isnt going to be so great.",
"Part of the reason is that religion supplies an answer for things not known. The more you know, the more that religious answer no longer applies. Religion is also oppressive in terms of control. Education leads to free will and that is less people wanting to be a part of a religion. Religion also supplies hope and a sense of family. That can be quite important when your life consists of a decent amount of misery. Having that family and close support system helps in times of grief and sorrow. ",
"I think a lot of people (in this thread) mistakenly think being religious equals ignorance, but if that were the case the advancements of science would be propelled by “atheists”, which absolutely was not the case (e.g. big bang theory/renaissance or Middle-East chemistry/algebra/medical). Also Japan is religious, the US is religious, westerner Europe is religious. The trend to less religion didn’t start well after these countries were considered developed.\n\nToday’s mostly developed nations are closely related to the allies after the second world war (western Europe), and those who had close economic ties with the US (Japan).\n\nI honestly have no proper explanation, but I think your question would be better formulated more like “what drives people in developed countries to become non-religious”. Since the cause and effect are, I believe, actually reversed ",
"A lot of the answers in this thread seem to be along the lines of, \"If your life is hard and you're not well educated, religion offers an easy explanation.\" I think this is overly cynical (and makes it easy to see people who live in poverty as being stupid, which is wrong). I would say that developed countries have more followers of \"material\" religions such as consumerism or nationalism. These are not usually seen as religions, but they have rituals (Black Friday, Independence Day), tithes (Shopping, Taxes), group gatherings (Auctions, Casinos, Elections), etc. These \"religions\" are attractive because they operate and produce blessings in the physical world, so faith is easy. \n\nI do think that, even if all that is true, developed nations tend to be more areligious than third world ones; and I think a major factor in that is that poorer communities have a culture of interdependence which helps religion and which religion helps, and richer communities lack that. In other words, when you're rich, it's hard to see how much you rely on people around you - it's easy to think that you can survive and do well on your own merit. Jesus said, \"It is easier for a camel to get through the eye of a needle than for a rich man to enter the Kingdom of God.\" I think this is something like what he meant."
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5i6rdb | why food heats faster if i double the oven temperature? | Why food heats faster if I double the oven temperature. Or if I want to cool down coke can, why it cools down faster in -60 celsius than -2 celcius. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5i6rdb/eli5_why_food_heats_faster_if_i_double_the_oven/ | {
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"text": [
"The rate of heat flow between two objects is dependent on the temperature difference between them. So two objects (the air and your food) that differ by 100 degrees will experience faster heat flow than two objects that differ by 10 degrees."
]
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5znfoa | atoms and us | My son asked me if his skin was made of Atoms, and I said Of Course. Anyone that has kids knows it doesn't stop there, and he got me thinking.
I understand atoms, and how they make up everything. but skin for example as he asked...
Do the atoms work together to make skin? Do we look under a microscope and see atoms? Im so confused now. Am I made of all atoms? Or do they work together with each other to form new products, so while it is made of atoms, it becomes something new?
Im confused please help...
| explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5znfoa/eli5atoms_and_us/ | {
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"Everything is made up of atoms, so yes, skin is too.\n\nFor example, skin is about 70% water, which is made up of hydrogen and oxygen atoms, 25% proteins which are made up by a bunch of atoms, but carbon, nitrogen, oxygen and hydrogen are the big ones there, and lipids which are also made up of hydrogen, oxygen and carbon (and sometimes phosphor). Then a bunch of trace stuff too.\n\nThe important thing with atoms is how they're bound. HCl is hydrogen chlorid, a toxic gas, while NaCl is sodium chloride, tablesalt.",
" > Do the atoms work together to make skin?\n\nYes, they compose the chemicals which make up the cells that make up skin. \n\n > Do we look under a microscope and see atoms?\n\nNo, they are far smaller than visible light.\n\n > Am I made of all atoms?\n\nYes.\n\n > Or do they work together with each other to form new products, so while it is made of atoms, it becomes something new?\n\nYes, they form molecules which make up more complex chemicals and structures.\n\n\n",
"Oh boy. I'm afraid this is a bit of a big topic, but here's an ELI5:\n\nYes. Everything is made of atoms (except atoms, but let's not go there). \n\nThere are many different elements (carbon, helium, hydrogen, oxygen, gold, iron, etc - look up the periodic table of elements). There are atoms of every element. They are different elements because of, well, the stuff *atoms* are made of which, again, let's not go there. \n\nIf you combine a bunch of atoms, you get *molecules*. Now depending on how *many* atoms you use, that molecule can be different *forms* of that element. But essentially the same stuff. \n\nIt gets more fun when you make molecules with different elements. Water, for example, is *not* an element. But you take a couple of hydrogen atoms and an oxygen atom and hey - water. \n\nSo, basically, your skin is made of different molecules which are, in turn, made of different atoms. If you want to get a bit more into it, your skin is mostly carbon, nitrogen and oxygen. But it has smaller amounts of many other elements. ",
"Atoms are like Lego. Different atoms can stick together with chemical bonds to build molecules, just like you can build all sorts of things out of Lego. The molecule has its own properties and behavior, but it's still a collection of atoms (Lego) all stuck together.\n\nYour whole body, skin and bones and all, is made of atoms, just like everything around you. Because atoms are very, very, very small, it is easy for them to make really detailed, complicated molecules like those that make up your cells. The types of atoms that bond together, and the pattern in which they bond, control how the molecule behaves. Some molecules are small, like water, and some are really big, like proteins.\n\nMolecules can also stick together and make even bigger structures. This is how your cells are built, and almost every single material we touch on a day-to-day basis. \n\nChemists can pull apart the atoms that make molecules and separate them out. You can then take those atoms and build new molecules.\n\nWe can even see atoms now with very powerful microscopes, like this one: _URL_0_",
"If you look at your skin under the microscope, you'll see a bunch of cells next to each other (sort of like a pattern, a building block, or legos). For each of those cells, you'll see an outline. That outline is called a cell membrane.\n\nIf you zoom in even more on that cell membrane, you'll notice that it's made up of two barriers. The two barriers are made up of something called a \"lipid bilayer.\"\n\nThe lipid bilayer is made up of single units called lipids (which looks like a ball with a few legs in simplified models). The balls (polar end) face the outside, and the legs (nonpolar end) face the inside, which sort of looks like this:\n\noooo\n|||||||\n|||||||\noooo\n\nWhen you zoom into those legs, you'll see that they're chains of carbon atoms bonded with hydrogen atoms. When you zoom into the balls, you'll see carbon atoms with oxygen atoms, and frequently other atoms like phosphorous (but as a unit they are polar, and attract water). \n\nYou can zoom into everything in the same way. Little by little. It's kind of like how you would start off by look at a map, and eventually be able to look into what sort of biomes make up the region, which add up to be what you see when you look at the Earth from outer space. In the case above, the skin from human vision is the Earth from outer space, and the lipids are the rivers. (Excuse the poor analogy!)\n\nI hope that makes sense. I remember thinking about how everything is made up of atoms... and it blew my mind.\n\nWhat blows my mind now, is that atoms too, are made up of units called quarks. But that's another story."
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oiffl | what is going on in myanmar? | Aung San Suu Kyi and many other political prisoners were released, Clinton visited... are we seeing real change here? Should we be hopeful?
What started all this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/oiffl/what_is_going_on_in_myanmar/ | {
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"Since it's history, Myanmar has been ruled by either totalitarian dictators or, more recently, a military council. In 2007, there were large pro-Democracy protests which resulted in a violent government crackdown and the death of 13 people (Burma VJ, a documentary, can shed more light on this). For some reason or another, the government has decided to promote political freedoms. \n\nMy theory is that they are doing this because Kim Jong-il is dead. The N. Koreans and the Burmese government have had a close relationship, and perhaps with the death of Kim Jong-il, the Burmese are seeking to better their relationship with western nations such as the US. Just a theory."
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3kom2y | how do solo concert performers memorize such long pieces of music | [example, Brahms - Piano Concerto No. 1 ](_URL_0_) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kom2y/eli5_how_do_solo_concert_performers_memorize_such/ | {
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"Most orchestra musicians have sheet music in front of them. Otherwise, they memorize through extensive practice and knowledge of music theory. ",
"1. Lots and lots of practice. And then more practice.\n\n2. Break it up into sections and memorize small portions at a time. If you think about it, you probably know the lyrics to dozens of songs, but you didn't learn them all at once. Memorizing a few measures of a song isn't that difficult, and once you get them firmly in your memory it's not too hard to learn a few more. ",
"The same way someone would memorize a speech. When reading you don't read each letter by itself, you read the words and phrases . Someone with that much experience no longer sees notes, they see groups of notes forming musical \"words\" and \"phrases\" which are much easier to memorize. That and tons of practice.",
"It's less about memorizing, more about knowing what you want to hear and being able to translate that into your instrument. When performing solo you can even change songs up and many people often do because you don't have to follow what other band members are doing.\n \nTake this guy for example. You will never hear this song played exactly like this by him in his other performances. \n_URL_0_",
"I learned to do it as a kid. Brains have no problem memorizing impressive amounts of data as long as the data's in certain forms, like a story. \n\nThe general process was to play the song through with the sheet music in front of you until you didn't need it any more. It's only a few minutes of music usually, so you can do like a dozen repetitions per hour. Over two weeks that's over a hundred times. You'll memorize anything if you do it that much."
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vw27u | what is the turing machine, and how did it
work with the google logo? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/vw27u/eli5_what_is_the_turing_machine_and_how_did_it/ | {
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"Turing machines is... a long strip of paper which can store data, a needle which can write and read data, and a way of decoding instructions which are written on that same strip of paper (technically you only need NAND to make every other instruction on a computer). Alan Turing proved that any problem which you could solve with a powerful computer can be solved with just a Turing machine.\n\nGoogle's doodle. Start at the play button and follow the instructions. The arrows change which square you're looking at; the 1s and 0s change the data of the square you're looking at; the squares with the arrow go to the next line of instructions if the square you're looking at is the same as the square in the little instruction picture. The repeat thing takes you back to wherever the arrow is pointing. The goal of the puzzle is to make your big data match the data in the little picture above it.\n\nThe first level for me says this.\n\nGo left, Check if the square you're looking at is blank. If it's not, go back to the left arrow and repeat. If it is blank, go to the next line. Line two says Go right, set the selected square to zero, go right, and from there on, you have to solve the puzzle! Play around with it.\n\n\n*edit* This might help: _URL_0_",
"A Turing machine is a mathematical model for a computer. Mathematicians want to have everything rigorously defined so to study computing they need a model for the computer. Turing machine is not an early computer or anything like it. It was never meant to be used as a practical device or to be actually built. But it captures some of the core concepts of an actual computer but simplifies away a lot of the details. \n\nThe Google logo only had superficial similarity to an actual Turing machine. It was actually just a small puzzle game where you did a bit of programming. If it hadn't been Turing's birthday or if the graphics had been slightly different people wouldn't probably even have recognised that it's meant to be a Turing machine.",
"Turing machines are the most simple machines that can solve *any and all* solvable computations. If there is something that can be computed, a Turing machine can do it.\n\nPretty much all computers are more powerful than Turing machines, but the \"more powerful-part\" is mostly about efficiency and extra functionality, all the code a computer can run could still run on a simple Turing machine.\n\nThese extra features in computers involve things like power management (saving battery), \"virtualization\", CPU core management, etc... Building a simple Turing machine as a computer wouldn't make sense, because our current computers are faster than what we could achieve with just a Turing machine."
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5l6mw6 | how do digital thermometers (such as in cars) display the correct temperature? how are they programmed to measure temperature? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5l6mw6/eli5_how_do_digital_thermometers_such_as_in_cars/ | {
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"Electrical thermistors. They change resisrancr based on temperature, then a computer or module (such as bcm in a car) interprets the resistance value and displays the temperature. SOURCE: I am an ASE and industry certified automotive technician "
]
} | [] | [] | [
[]
] |
||
51yb3p | why does apple constantly run out of iphone's on launch date? | I get that it could happen a couple of times, but come on, it's been almost 10 years of the same story, **iPhones sold out** I would think that Apple would figure to just make more of these by now... Or maybe the increase in demand year-to-year is so big that there's just no way manufacturing can keep up with all the new people that now want a phone. Or maybe it's just marketing, d'you guys know? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/51yb3p/eli5why_does_apple_constantly_run_out_of_iphones/ | {
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"Intentional strategy: they're creating the demand by shorting early availability. This is a standard strategy for a lot of things.",
"_URL_0_\n\n > THEY CREATE THE ILLUSION OF SCARCITY TO INCREASE DEMAND\n\n > Luxury goods marketers have long realized that scarcity (real or perceived) makes a product more desirable and in demand. Scarcity not only increases the value of a product, it propels the procrastinators and all us who want to be part of the trendy crowd to step up and buy. That's why it is a favored tactic of designer handbag manufacturers and other luxury goods. Apple has found its own ways to hype the sense of faux scarcity. It did not have enough phones available when it went on sale. Just one hour after the iPhone 5 went on sale for preorders on September 14, 2012, the Apple website reported that heavy demand had necessitated delayed delivery. Adding to the illusion of scarcity was the fact that you could only preorder the phone, and lines were long. The tactic worked. Not only did the iPhone 5 set a record for first-day sales, even two weeks after the iPhone went on sale, it was on a back order of three to four weeks, prolonging the difficulty (and desirability) of owning one.",
"They run out on launch day because of the way iPhones are built.\n\n\nEvery phone needs iOS flashed on it before it's boxed/shipped. iOS 10, which ships on the iPhone 7, generally goes final one week before they keynote. So by launch day there are, say, 10 days of phones manufactured. And that's not 10 days of iPhones, that's 5 color variations, 3 capacities, and 2 sizes, plus any carrier-specfic variations (ie: currently there's a GSM specific variant with Intel chips and the normal CDMA/GSM variant).\n\n\nLet's say you can make, say, 500,000 phones per day. That means you have about 5m iPhones ready for shipping on launch day. Oh wait, you need some for retail, and you need to ship a bunch to your various carriers. So those 5m iPhones turn into (5 * 3 * 2 * 2 = 60) 60 different kinds of iPhones, so you only have 83,333.3 iPhones of each type. those are sent to various partners worldwide on allocation, probably.\n\n\nHow many people are preordering? A lot more than that.\n\n\nThe fact is, it's unbelievably difficult to manufacture 500,000 of anything a day, especially something like the iPhone. FoxConn/Apple were doing that in 2013. By now maybe they're up to 700,000...but at some point it's not worth it to increase production for launch day, because what do they do with that extra capacity when the peak demand subsides? It costs a lot of money, time, and management to keep a production line going.\n\n\nThe \"generated demand\" idea is stupid, and was created by some reporter back in the cabbage patch kids days. Don't you think Apple wants your money? If you don't you're a moron. Apple wants all of your money. If they could magically make 50 million iPhones in 10 days and make it cost effective they would. Even cereal manufacturers can't make 50 million corn flakes in 10 days...and cereal is orders of magnitude easier to make than an iPhone.",
"Because it creates a greater sense of demand for their products by creating the illusion that they are exclusive devices that not everyone will be able to get.\n\nIt helps create a spectacle around their release dates which in turn drives more sales as people fight to get their hands on a device.\n\nIt seems counter intuitive, however, people place a higher value on things that they have to work harder to get and manufacturing a scarcity forces people to put in that effort and therefore value the product more.",
"You can only start producing new hardware so far in advance due to issues like: continued manufacturing of current models occupying production lines, having the final OS ready to install on devices, where to store millions of devices for weeks/months securely, increased possibility of leaks.\n\nAlso, look at how rapidly [iPhone sales](_URL_0_) have increased year by year... sales tripled from 2011 to 2015 after having tripled from 2009 to 2011.\n\nAnd at the end of the day, it's better marketing/PR to have stories about how the phone is so popular it's sold out than to have a glut out of the gate."
]
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[],
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"https://www.fastcompany.com/3001650/5-marketing-tools-apple-exploits-build-hype"
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[],
[],
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"http://www.statista.com/graphic/1/276306/global-apple-iphone-sales-since-fiscal-year-2007.jpg"
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|
9n5h22 | if we cna raed wehn teh ltetrs are lkie tihs, why can’t we understand easily when speech is run backwards or scrambled? | (If we can read when the letters are like this” referencing the fact that it is relatively simple to read a word when the first and last letters are in place but the rest are mixed up) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9n5h22/eli5_if_we_cna_raed_wehn_teh_ltetrs_are_lkie_tihs/ | {
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"Ok. Ill take a stab. My knowledge comes from taking a few literacy and reading courses in grad school. \n\nThe reason we can read words that have inverted lettering is that as we get better at reading, we actually stop reading and repeat the words from memory. Our brains need the first and last letters to be in the right places, and the interior letters can be scrambled. This is enough information to prompt out brains to recognize the words. This is part of the reason that young readers can be so slow as they have not yet “memorized” the words. This also means the more you read, the better at reading you will get. \n\nMy explanation basically just scratches the surface and Im sure an expert could go a little further into the physiology of it. \n\nEdit/addition: “reading” actually means that you are decoding the parts of the word (called phonemes - I THINK) while you process the word. The more you read, the less you actually read. ",
"The scrambled-word effect you refer you is *mostly* fake, the product of a hoax chain email that was passed around 10 or 15 years ago. There isn't actually much research about this effect, and most examples are hand-crafted to be very easy to decode.\n\nUginsrrsnpiluy inidadluvis wniitrg pehrass wcihh uiiltze liheetgnr snittemens are mroe bundmosere to prase crelctroy. \n\n(Did you understand that? \"Unsurprisingly individuals writing phrases which utilize lengthier sentiments are more burdensome to parse correctly.\")\n\nHowever, using context clues (both from surrounding words and from the fact that we are very familiar with how English words tend to look), it *is* possible to decode minor scramblings.\n\nWhat's more, there is research into a similar effect on spoken language. MacDonald & Brew (2006) found that if the start and end of each word are kept the same, but the middle is played backwards... people can understand a spoken sentence. Again, context and our recognition of common English words and sounds is what's going on here."
]
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[],
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94agps | how is measured the thermical sensation, the temperature that we feel | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/94agps/eli5_how_is_measured_the_thermical_sensation_the/ | {
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"Thermoception (yes, that's actually what this is called) isn't actually sensing temperature, but sensing heat flux (or, the movement of heat into or out of your body). Because heat flux is determined in part by temperature differences, the greater the difference in temperature between you and the object you're touching, the hotter or colder it will feel to you.\n\nHowever, heat flux is also partially controlled by heat capacity and conductivity, or the ability of a substance to hold on to heat and to move heat. The result of this is that an object with more heat capacity/conductivity will feel hotter or colder than another object at the same temperature with a lower heat capacity/conductivity. The most common example of this would be metal vs. wood at room temperature; the metals will feel cooler because they have a much higher heat capacity and conductivity, and are much more accepting of the heat your body puts out naturally."
]
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[]
] |
||
b94mr8 | how does cool sculpting work to freeze away fat | I've been seeing a lot of advertisements for different methods of freezing your fat away. i.e - cool sculpting. Can't be that easy to get rid of fat.. can it?
& #x200B;
& #x200B; | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b94mr8/eli5_how_does_cool_sculpting_work_to_freeze_away/ | {
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"text": [
"It crystallizes fat cells which are dead once broken down. Then the dead cells get taken away by the body as waste. The amount of cells that crystallize varies, and I've heard it's not the most comfortable thing in the world. The best answer to weight loss is still exercise and a balanced diet."
]
} | [] | [] | [
[]
] |
|
6azcwx | why does hydrogen peroxide works so well as a disinfectant? how does a substance necessary for life turns into another that easily becomes toxic? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6azcwx/eli5_why_does_hydrogen_peroxide_works_so_well_as/ | {
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"Hydrogen peroxide is two oxygen atoms and two hydrogen atoms stuck together, but this is incredibly unstable. Oxygen *does not* like to be stuck to other oxygens, except for perhaps O2, but even that isn't particularly stable, hence why it will readily burn and become CO2 and H2O. Hydrogen peroxide would much rather be H2O, but that leaves the extra oxygen left out, and as much as oxygen doesn't like being attached to another oxygen, it *really* does not appreciate being alone.\n\nThis has to do with the electron cloud around the oxygen atom. Atoms will attract electrons to fill the cloud to a full 8 in the outside shell. Oxygen has 6 electrons in the outer shell and would be more stable at 8, so it will immediately snatch them up from other atoms. This is called electronegativity.\n\nSo the H2O2 immediately decomposes into H2O and free oxygen, and that free oxygen reacts to whatever atom happens to be close to it, even if that atom is, say, part of the DNA of a bacteria. That will tear the atom out of the DNA, potentially destroying the DNA and killing the bacteria. Or it could rip an atom out of any part of the bacteria.",
"\nMy dad likes to talk about this (he's a molecular biologist). Oxygen is incredibly powerful - it is paradoxically able to both sustain and destroy life. I'll leave it to a chemist to explain how but I just think it's amazing."
]
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5t6j3y | what is the difference between butter and margarine? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5t6j3y/eli5_what_is_the_difference_between_butter_and/ | {
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"Margarine is a non-dairy product created as a substitute for butter. While originally made from animal fat in the 1800s, today the primary ingredients include vegetable oil, water, salt, emulsifiers, and some also include milk.",
" > Tub margarine can easily be substituted for butter at the table for spreading, and some people use it on the stovetop for cooking, though we typically favour using oil over margarine in cases like this. In baking, melted margarine could work in recipes that call for melted butter, but in recipes that call for softened butter, swapping in tub margarine may change the texture; for example, cakes will be less tender, and cookies will generally spread out more and be less crisp.\n \n > Tub margarines are too soft for pies, pastries and other recipes that call for cold butter, and don’t stand up in icings and frostings, either. Low-fat/light margarines tend to be inappropriate for cooking and baking due to a high water content – be sure to read the label!\n \n > Stick margarine, also known as block or hard margarine, has the same texture as butter, and is therefore a better substitute for baking and cooking than tub margarine. However, stick margarines are generally high in trans fats, which have been shown to be bad for our heart. "
]
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[],
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|
1plnen | why do mother, father, and daughter end with -er and son doesn't/seems so different from the other three? | Mother, father, and daughter seem similar to me while son seems to differ from the other three so much.
The online entymology dictionary may as well be Mandarin for as much sense as it makes to someone who didn't study English or Linguistics. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1plnen/eli5_why_do_mother_father_and_daughter_end_with/ | {
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"The Online Etymology Dictionary says that the oldest form of \"[mother](_URL_2_)\" incorporates *-ter* as a \"kinship term suffix\". If that's true, the endings of \"[father](_URL_1_)\" and \"[daughter](_URL_0_)\" may well come from the same source. Someone on /r/linguistics might be able to say with more confidence, and perhaps tell you whether there are records of a Proto-Indo-European term meaning 'son' that had the same ending. ",
"All of those words have roots in [Proto Indo European](_URL_0_) languages, dating back at least 5000 years. And the difference in the ending existed even then:\n\n- Mother = meH₂tér\n- Father = pH₂tér\n- Daughter = dhugH₂-tér\n- Son = suHnú\n\nNouns in PIE were very complex, with three different genders and eight different cases that could modify the word, and changes in vowel sounds would subtly alter the meaning of the word (think about sing/sang/sung/song in English).\n\nHowever, I'm no expert on PIE, and the endings of those words don't seem to match any patterns that I can find in any on-line documentation.\n\nSo all I can say for certain is that these differences are at least 5000 years old. Perhaps someone with a deep knowledge of PIE can explain why the endings are the way they are?",
"The explanations here dont quite seem to add up. Take another point of view :\n\nSanskrit is arguably the closest extant language to the Proto Indo European (PIE) root from which all these words are described. The most common forms of these words in Sanskrit are :\n\n- Father : Pitaah \n- Mother : Maataah\n- Son : Putrah\n- Daugther : Putree\n\nSo as you can see, it all works out. The word for daughter and son are just the male/female versions of the word denoting an offspring, they all have similar morphology.\n\nNow, there was also another word in Sanskrit : Suut or Suutah. This was most often just an alternate form for child / children, and often also referring to the male son (as in the next in line) as the same word Suut also implied a thread or continuation. Further, there was another word as well : Duhitree an endearing female term related to describe the milk drinker or (suckling infant). \n\nSo it just seems that Son and Daughter are derived from these alternate (endearing) forms of PIE words that the above Sanskrit words likely derived from, unlike the rooted words for father and mother which were preserved across the PIE branches. "
]
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"http://www.etymonline.com/index.php?term=father",
"http://www.etymonline.com/index.php?term=mother"
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|
5umnpy | what does it mean to "optimize" a game? | In response to this post: _URL_0_
I get the general idea of what it does, but what do developers actually "do" when they optimize something? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5umnpy/eli5_what_does_it_mean_to_optimize_a_game/ | {
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"Generally optimizing in video games is trying to get the same result by doing less work. This is usually accomplished by smarter use of the platform on which the game runs or removing redundant/useless operations that were not obviously wasteful before ",
"Imagine that you have a tree, and it has some apples.\n\nThe tree drops apples every now and then, and you pick them up.\n\nYou then give those apples to someone else and they count them.\n\nWouldnt it be better if you count the apples while picking them up, and tell the guy the number of apples + give the apples? This is called optimization.\n\nMaybe not counting apples, but maybe items in your inventory, NPCs around, damage calculation formulas, line of sight.\n\n---------------------\n\nin your linked example, the video card would pick the apples so fast, and the other guys would count them so fast, that you wouldnt notice the need for optimization, while older graphic cards would greatly slow down waiting for the recount of the apples.\n\nsource: bachelors and masters in computer science.\n\n",
"one can optimize by \n\nA, rewriting the code to do the exact same thing but smarter. \nFor example, if i wanted to calculate all primes under a million that also happen to be palindromes, i can first calculate all primes and then check how many of those are palindromes, or i reverse it, one is significantly faster than the other, but the end result is the same.\n\nB, rewrite code to do approximately the same, when animating a character covered in fur, you can animate every individual strand, but that's utterly insane, instead, how about you animate about 20% which gives a very similar feeling of natural movement for one fifth of the cost.\n\nC. Axe features which turn out to be unfeasible. Sure its nice that the water gives a perfectly natural reflection while in a fucking hurricane, but do you really need to dedicate 90% of your gpu to that? How about you just insert a amorphous blob instead? no one will notice. \n\nD. Work together with third parties like graphic driver developers, so that they update their drivers to include some specific changes just for your game. (this is naturally only open to the bigger dev companies.)\n\nNaturally developers prefer to do A or B, but when the deadline approaches and the limits of the hardware can't be pushed any further, sometimes C makes an appearance and really cool stuff gets removed.\n",
"I'll give you a quick example, as I recently released a game on mobile, a platform where you're particularly constrained on resources. There's other kinds of optimizations, especially ones that are much more \"lower level\", but this is one example that came to mind.\n\nIn my game, there's an effect where you can freeze an enemy and shatter it, causing about 20-40 shards of ice to explode away. They have physics, bouncing on the ground and fading away. I was getting bad performance when these pieces were created, because instantiating an object and all its associated components can be pretty intensive on performance. As a solution to this, I \"optimized\" it by having a pool of about 200 of these shards created at the start of the game. They are dormant, and placed well off screen. When I need them to be \"created\" for the shatter effect, I actually just move them to the game world, activate them, and once they fade away they actually go back to the off-screen pool and reset themselves. This made the performance of the effect much, much better.",
"In computer programming there are many ways to accomplish the same results. The most straightforward - and less resource demanding - way of doing something isn't always clear right off the bat. Usually we can't write a program on it's most efficient form right away.\n\nNormally when we start to construct a program we are more interested in asserting the viability of such solution and see how it fits within the rest of the system (in this case, a game). Once we got it working right, we might focus on refining, cutting corners and getting rid of unnecessary steps.\n\nOptimized programs tend to become harder to understand and harder to modify. And that's another reason for the programs to begin their life as \"unoptimized\". The optimization process comes after the program is complete and not likely to be further modified.\n\nOne such classical (and possibly obsolete) technique back in the PC-XT assembly days was the obnoxious [loop unrolling](_URL_0_). Basically we would get a portion of our program that's supposed to repeat a number of times and actually replicate the same code as many times as needed. This way, the CPU wouldn't waste time controlling how many times such piece of code was already executed. It would be simply executing a long list of commands seemingly unrelated.\n"
]
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3kgkg8 | why is the indian stereotype so common in "comedy" tv-shows? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kgkg8/eli5_why_is_the_indian_stereotype_so_common_in/ | {
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"text": [
"because people can find stereotypes funny. \n\nPossibly Indian shows have stereotypes of Americans as a comedic part of them. Certainly most countries stereotype people inside and outside their country. Sometimes for hate reasons, other times for comedy reasons."
]
} | [] | [] | [
[]
] |
||
70cpb5 | have we ever found a 'sleeping t rex'? i mean, what did a tyrannosaurus look like sleeping? are they more like horses or dogs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/70cpb5/eli5_have_we_ever_found_a_sleeping_t_rex_i_mean/ | {
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" > Have we ever found a 'sleeping T Rex'?\n\nBy necessity all the fossils of dinosaurs or anything else we have found have been dead. This generally limits our ability to determine what pose they would take while sleeping."
]
} | [] | [] | [
[]
] |
||
454txx | what would happen to the sun if it was dowsed in water | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/454txx/eli5_what_would_happen_to_the_sun_if_it_was/ | {
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"It would actually get hotter.\n\nWater usually puts out fires because the water prevents the fire from getting more oxygen to sustain itself. However, the sun isn't a big ball of stuff on fire. It is powered by its own gravity.\n\nThe sun crushes down on its center so hard that the hydrogen therein fuses together into helium, which releases A LOT of energy. Spraying a ton of water at the sun would only make it more massive, meaning more gravity and thus faster fusion.",
"[It would get hotter and brighter](_URL_0_). The Sun is not fire, it doesn't burn. The fusion energy is powered by mass. Increase the mass and you make it go faster and hotter. It would go out sooner, though, because by increasing the rate at which it fuses its fuel, it'll run through it faster. If the ball of ice is big enough you might even get the sun to go supernova and turn into a black hole...But you'd need a *really* big ball of water."
]
} | [] | [] | [
[],
[
"http://what-if.xkcd.com/14/"
]
] |
||
5woe50 | why can't we just cover a proportion of the desert with solar panels to provide the world with energy? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5woe50/eli5_why_cant_we_just_cover_a_proportion_of_the/ | {
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"Storage and transportation. \nYou can keep a barrel of oil for months and it will still be good. \nYou can cart a barrel of oil halfway across the world and it will still be good. And we do this. A lot. \nA barrel also doesn't cost much to make and can be made out of cheap materials. \n \nGetting solar power from the Sahara to Stuttgart is going to be difficult. \nOnce it's electricity it has to be used immediately. \nBatteries are really expensive and made out of things that are bad for the environment. \nOther cheaper things like boiling salt lose energy very quickly. \nBuilding power lines that far will cause a lot of power to be lost on the way. \n \nSome scientist are working of a way to turn the energy into oil and burn it later, but it's still in the experimental phase.",
"Who would be doing it? If you're doing it for the public good that's a government project and you need to convince stubborn politicians that it's a good idea. Good luck with that!\n\nIf you're expecting to make money you need to deal with ongoing maintenance costs as well as the initial setup (even if initial setup is relatively cheap these days). And then you need to make they money back by selling the power, but what if the price of power goes down because you're providing it in such large amounts?\n\nThere are some practical concerns though.\n\nMoving electricity is not free or completely efficient. Distributing power around an entire country ends up wasting a lot of it and requiring strong infrastructure and these problems would be even worse with one central source a far distance from where the power is used.\n\nAnd what about nighttime? Storing electricity is a problem that has NOT been solved on the type of large scale such as \"powering a whole country\". And solar panels on opposite sides of the world somehow covering for each other when one side is in the dark increases the problem of distribution even further. ",
"* Solar panels are expensive.\n* Installing and maintaining them is expensive, especially in remote areas, especially with dust and not much rain - you want to clean them.\n* Cables to connect them to the grid are expensive.\n* The sun doesn't shine 24/7, you need some storage system or other electricity sources in addition.\n* There are projects in deserts, but they are not very cheap.",
"Short answer is, we could, but it's not entirely efficient, and it would require a big chunk of money, and we'd have to deploy *vastly* more than we'd want/need to make up for that inefficiency.\n\nOther people are saying electricity can't be stored. This is obviously false. Even taking aside batteries, electricity is just energy, and you can store energy countless ways: pump water uphill, then harvest hydropower later. Lift a heavy weight, harvest the energy later to produce power, etc, etc. There are even solar plants that are [specifically designed for nighttime power generation](_URL_0_).\n\nThe other end of it is forcing transition. Oil/gas is still cheap, and there is a *huge* amount of infrastructure in place for deploying it. It's going to take a long spin up before we can compete with that. ",
"Largely because the sun goes down at night.\n\nWe have few effective ways of storing large amounts of the energy we produce. That means at any given moment, we have to produce about as much energy as we consume.\n\nOur current power grid is divided into two main kinds of generation. *Base load* is cheap and efficient power that is slow to start up, like coal fired steam turbines. This provide most of our power, but is slow to adapt to changing demand.\n\n*Peaking load* is provided by more expensive but quick to start up sources, like diesel generators. They can be started and stopped rapidly as demand requires.\n\nUnfortunately, solar and wind power are not real good at either, because you can't presume they will be available. At best they provide a buffer between base load and peaking load, but both of those other energy sources need to be available.",
"Well, they are doing that in places but it's still expensive.\n\nAfter it's all set up, the panels need to be maintained. They will get dirty and hit by sand. \n\nAlso another big reason is do this disrupts the local ecosystem. \n\n\nNow the whole, sun goes down at night? Well yeah that is a problem but I don't think OP is just saying depend solely on solar. ",
"The Transmission grid is much more (complex / fickle) than you think as well. You cant just simply pump a few electrons through some metal and have everything work. \n\nAll of the load must be managed instantaneously with the generation. This equation not only includes the amount of power but the frequency as well. \n\nThe utility has to constantly manage the fluctuating frequency of the load on the grid. Which is not consistent with solar or wind. In the US its around 50HZ. The frequency your electronics run on. If this gets out of wack the whole grid can collapse. \n\nIts issues like this that cause renewables to be a much more problematic energy source than the general public understands. \n\nSource: I work for large utility and renewable are a pain in our ass. ",
"People use a lot more power when the sun is down and we don't know how to store power in bulk. You also have to be reasonably close to the source.",
"We can't, (yet), power the world from a single location, but you could provide an entire country, (or countries), with immense power from solar farms on deserts. It's still a much cleaner, cheaper, (in the long term), and more logical idea than the power sources we have now. ",
"Only one other person mentioned it, but why would we do that? Most of the world's deserts have incredibly fragile and ancient ecosystems. It is pretty interesting but read about the microorganisms that live in the sand at White Sands National Monument. I believe you are not allowed to stray from the path because of how fragile the organisms in the sand are. They have created these layers on top of the sand over long periods of time. That would be a great place to put millions of solar panels but at what cost?\n\nAlbeit mankind is not known for giving two shits about what we destroy. Also, it would be a logistical nightmare. ",
"Two reasons:\n\n1. Electric power is lost if not used or stored immediately. We often want to use electric power during hours when the sun isn't shining. Storing power it is expensive and difficult (but we're getting better at it).\n\n2. There's a significant amount of power loss that comes with transmitting electric power across long distances. High-voltage lines are more efficient, but longer lines experience more losses, so it's not practical to generate power in the Sonoran Desert for consumption in New York.",
"2 Short answers:\n•Money: who will pay\n•Dispute: who's land is it, if it's profitable who gets to own it?",
"Cost, maintenance.\n\nAnd the real kicker: transfer losses and storage.\n\nNot enough people would live near by to be able to maintain it cost effectively.\n\nSand can cause wear and tear on \"things\" so you would have to engineer around that.\n\nAnd no major population centers nearby deserts, typicall, so the amount of power lost on the wire would be very high.\n\nAnd storage: would still need to produce power at night.\n\nSo a hybrid approach would be cool.\n\n\nI don't know why they don't put solar collectors on the outsides of the windmills.",
"It would be better to cover up drinking water resevoirs with floating solar panels as you help save water from evaporation and use space closer to a city",
"1_ it is being done in Morocco and other countries.\n2_It doesn't need to be that sunny to generate electricity, Germany generates more solar power than the USA even though southern USA is way hotter than Europe.\n3_ AS prices for the panels drop, it will happen.",
"So electricity. It needs to be moved and can only be used as generated without significant infrastructure. So lets just look at moving Electricity from Arizona to say Maine.\n\nLine losses. Electricity needs to be at high voltages to move it. that is why AC won out over DC. Not because Tesla rocked and Edison was a jackwad, but because DC has a limited transmission range. Literally in the couple miles range. \n\nSo we need AC. Solar generally makes DC. So the DC needs to be put into a converter that makes the DC into AC. Because we live in reality and not theory or make-believe there will be losses in converting the DC to AC. \n\nAlso a line 100 miles (160 kilometres) at 765 kV carrying 1000 MW of power can have losses of 1.1% to 0.5%. A 345 kV line carrying the same load across the same distance has losses of 4.2%. So if we ran 765KV line from Arizona to Maine is like 2800 miles long. That is a considerable amount of losses. That comes out to about a 25% or better loss in the transmission of that power. \n\nSo to combine the losses in the generation and swap to AC and the line losses you end up losing a huge amount. Additionally at the beginning and the end you have to step up and then step down the voltages. That incurs more losses. So overall the losses from the Sun hitting the PV panels to someone turning on their TV in maine incurs a huge efficiency penalty.\n\nSo while the solar source is free, the transmission equipment, transformers, and all the other equipment is not. So now if you take the standard that solar runs at: about 10-25% and apply that and the losses you get huge generation numbers for what would need installed. 11 million MW hours of power were consumed. \n\nSo to math this 11,000,000 MWh of power needed. So we need to up the production to account for the losses. So let's divide that up into 365 days of use and 24 hours per day. That comes out to needing an average of 1255 MW of production. Now we add the losses we have to make up for. That comes out to 1794 MW of production. Then we have to throw in the Capacity factor of solar. The industry runs low compared to other power systems. But a plant in Arizona has been hitting 29% so we can use that. that means we need to start with 6185 MW of faceplate capacity. \n\nAnd we need to be able to store that power. We haven't added storage in yet. Since the solar must be stored some place for when the sun is down. That will add in more losses and therefore more base capacity to meet the needs of the end user. \n\nAgua Caliente is 84 MW of faceplate capacity on 2400 acres. So we need to multiple and we come up with 176,735 acres give or take. That is about 276 sq. miles of solar. \n\nThe problem is not with the production of solar electricity. The problem is with storing and moving the solar electricity. The other thing we have not talked about is maintaining grid stability. Thousands of small PV site feeding into a huge grid with nothing to anchor the grid will make it unstable. When a large industrial plant starts a bug line up or a aluminum recycler starts the induction heating process that load has to be absorbed and these small PV suppliers cant handle it. \n\nThere are vast engineering problems that need to be solved here. NO it is not impossible, but it needs to be looked at as a whole, not just little pieces. Too many people assume the only thing that needs power is homes and basic lighting and ignore the rest of the grid and the businesses and industry we have in this country. We need a grid they can rely on. The problems are solvable, but not by activists pushing their favorite flavor of solution or the neat product of the day. \n\nPower walls are great. Except for all the drawbacks they have that we ignore. Solar is great except for some of the drawbacks. nuclear is great except for some of the drawbacks. \n\nAsk your self why we are shutting down already operational and carbon free nuclear plants, but are willing to pay extra in taxes to build carbon free NEW renewables. It is stupid. And it ignores the facts of the grid and engineering. Solar cannot be used as abase load. And the technology for storage is more in its infancy than renewables are. And before we can really have any chance of renewables really supplying the whole of the grid, storage has to be solved. \n\n",
"Electricity carried over distance loses strength. If you want to power the world from a single spot, you'd need mythical power lines that are much more efficient than today's.",
"-First you have to convince politicians to get on board. \n\n-Then they have to convince the public to get funding. It would be expensive. So convincing everyone will be difficult. Do we raise taxes?\n\n-The cost maintenance is expensive.\n\n-There is also the environmental impact of it. \n\n•Solar panels require lots of water. for cleaning. \n\n•Where does the water come from? \n\n•How do we pump it? \n\n•How much will that cost?\n\n•What do we do with the grey water? Recycle it? \n\n-How will it affect the wildlife?\n\n•Even though a desert may be. inhabitable for humans there is probably a great deal of wildlife who's entire world revolves around the desert. So how will covering an entire desert in shade affect the ecosystem? \n\n-Even if we conclude solar panels won't have a negative environmental impact, we need to make sure the construction won't have an impact either. All those trucks and machines could disrupt the fragile ecosystem that's inplace.\n\n-Also solar panels are still new. Every year they get more and more efficient. So at what point do we start replacing the panels with new ones? \n\n-How much will replacement cost?\n\n-Where do we get funding for that?\n\n-Will there be any environmental impact when we begin replacing the panels? Again all those trucks and stuff.\n\n\nAll in all its not cheap and we could be potentially disrupting vital ecosystem. And if there are any endangered species involved it would be even more difficult to get the green light.\n\n\n\nI should note I'm no expert. We discussed this in class the other day and I'm just posting what my notes say. Also this is on mobile so sorry for spelling grammar or formatting errors ",
"After reading the (very informative) comments in this thread, I have switched from being a pro-renewables hippy to basically Daniel Day Lewis in There Will Be Blood.\n\nI'm an oil man.",
"1. Power lines don't efficiently transmit power over very long distances. \n2. A single large target would be easier for a terrorist to attack than several spread out plants. \n3. Our existing power network would need to be gutted and replaced with smarter, more compatible networks. \n4. Balancing power loads would be more difficult (by comparison, current networks sell wattage to partnered networks when demand is high/low). \n5. We would need a revolution in energy storage. \n6. It's night half the day. ",
"In addition to all the other replies that focus mostly on a technical and economical perspective, there is also a whole other one:\n\nIf even your country alone (let alone the world) relied on one single source of electrical energy, you're going to have to invest a lot to make it secure and reliable. \n\nImagine you built a giant solar farm in the Sahara desert to power your country (let's say Italy). Your power is now being imported from a different country. You might have contracts with them that permits you to use this power generated in their country, but what stops a corrupt government or revolutionists to cut your power? You may guard your solar farm, but if it's big enough to power your whole country, you'll need lots of guards. Such a project would also be easily attackable by terrorists, so it's really insecure.\n\nWith that aspect alone, how would you find investors? Likely nobody would want to invest in an energy source that's so likely to be taken over by rebels or terrorists.",
"Actually, you dont need any solar panels to provide the entire world with unlimited electricity. All you need is a single cable. Run the cable north to south. That cable will pick up solar radiation and generate electrical current through it. This has been known since Galileo's time. ",
"We send electricity through wires from power plants to our home.\n\nThe energy (electricity) that we add to the system is equal to the energy taken out of the system, **minus** electrical friction (heat) losses.\n\nThe longer the distance from the power plant to our home, the more heat energy that is lost in the transfer process.\n\nTo transfer from deserts to the world would cost too much in terms of energy loss to be benefitial.",
"Just the cost to install would be mind-blowing, let alone maintenance.\n\nThe approximate cost to install solar panels is $3 to $10 per watt generated. It's a large range, but it really depends on the quality, amount, and area you're installing them. The current worldwide power usage is about 340 watts, so the cost for solar panels is between $1,000 and $3,400 per person. That seems pretty reasonable until you realize there's 7.5 billion people on earth, so you're looking at a cost of $7.5 trillion to $25.5 trillion. That's just to install the panels, it doesn't even cover the cost of the land, the labor, or the maintenance of the panels. And that's even ignoring the cost to transport such a large amount of power around the globe.\n\nI know what you're thinking... so what about just the United States. Well that 340 watt per person figure was worldwide, if you take just the United States into account then you're looking at 1380 watts or approximately $4,000 to $14,000 per person. At a population of 319 million, you're looking at approximately $1.27 trillion to $4.47 trillion... again just for installation.",
"Intermittency - the sun goes down at night and cloud cover is still difficult to forecast more than a day ahead.\n\nLocation - the cost and losses involved in transmitting electricity from the sunniest regions to the least sunniest regions makes the enterprise unviable.\n\nEngineering - the grid can't handle it, you need responsive energy generation to handle peaks and troughs in demand.\n\nInvestment - Leaving the aforementioned problems aside, it would be disastrous to invest the enormous sums needed to scale up solar PV only to find that more efficient solar cells were developed a few years later, or some other innovation rendered the solar fields obsolete.\n\nEnergy return on energy invested - Solar is currently way behind Wind, which still slightly lags behind oil (although the newest, largest turbines are catching up)",
"Largest solar power plant in the world under construction in the Sahara desert for 2020. \n\n_URL_0_",
"There's a lot of good answers, but none are ELI5, maybe this will do it:\n\nMoving electricity along wires from PV solar panels causes a lot of loss of power so you can't have the solar panels too far from the people who need the power\n\nSolar only generates during the day, people need power at night too\n\nTech for storing power over night isn't very good yet.\n\nThere are non PV (photovoltaic) solar power options, some of these (molten sands, thermal) offer ways to store power, but they aren't as developed as PV\n\nLocal power storage (like tesla pwerwalls) allow local PV generation to be stored, and if taken up in sufficient numbers would allow more use of renewables, but, govt is anti renewables :-( sad.\n\nAll of the problems have solutions but vested interests are lobbying against them\n\n ",
"WE CAN. in 2008 a 500ish billion project called desertec was launched by Germany, the EU and a bunch of other investors to build exactly that in the sahara. \n\nHowever unfortunately as the project was getting started the Arab Spring happened. (in 2011 people got very unhappy with there goverments in the Arab world and started lots of revolutions and wars) So people got scared and thought it would be to risky to build in those countries.\n\n It is however now picking up pace again and north African countries are starting to build huge solar farms (with some being solar thermal which even generate at night) but they want to power there own people first.\n\nSimilar China has built a huge 2000 mile HVDC transmission line from the western deserts to its coastal cities so that the can start building solar farms there. \n\nOther projects being done to bring energy from far places to places where people live include HVDC lines linking volcanoes in Iceland with Europe so they can send Geothermal power to Europe. ",
"Aside from the moving and storage problems, there's the whole environmental impact and simple maintenance. \n\nYou'd need a TON of solar panels to create enough solar power for everyone, which means you build a giant solar farm out in the desert. This jacks with the local ecosystem. Then you need to keep the panels clean so they can operate at maximum efficiency. That means you need a lot of water to clean them. If you set these up in the open desert...where there really isn't a lot of water...now you have to ship water in just to clean them.\n\nThen there are the solar plants that use giant mirrors to reflect sunlight to then heat up water for steam generation. These things also take up lots of land, which then negatively effects the ecosystem. Birds literally get fried in the air if they fly into one of these, and the heat generated creates a giant warm air updraft that messes with planes. \n\nThere's still a lot to work out. I think having massive solar farms out in the desert is impractical. I think the real solution is having a combination of solar and wind generation on your own property with battery storage. It's the only thing that makes sense. ",
"If this would work then how much better would it be to put billions of solar panels in space between here and the sun and have them just beam the energy to earth.",
"Don't know if it's been mentioned yet, but deserts are also full of sand and wind which can scratch and damage the surface of the panels at worst, and at best require regular cleaning\nThere are robots you can hire if you have large enough farms but they would need to be in constant use and power would drop during sandstorms\n\nNight is also usually very cold in the desert, so the big change in temperature on a daily business from high max operation temp to low 0-production temp is an engineering challenge in itself\n\nTL:Dr harsh environment = damaged components and maintenance costs\n",
"_URL_1_\n\nRead this and you'll learn why...\n\n_URL_0_\n\nIt's not very effective. Look at the comparison from the solar panels to Palo Verde Nuclear Power Plant. \n\n",
"I would rather see power production move smaller scale than larger. In a perfect world, every house would have its own power plant. It would be a consideration when buying a house and would be something to maintain on your own, just like your roof, furnace or water heater. I know for regions without a lot of sun or wind the tech isn't there but I'd like to see the push in this direction. ",
"We will be able to do so, someday.\n\nHVDC is a cheaper way of transmitting electricity than HVAC if the distance is *large enough*. [source](_URL_0_). \n\nThere are new batteries being developed that should be *safe* and *not-environmentally-disastrous*. [source](_URL_1_)\n\nMy guess as to why we are not doing it right now is that there is already a lot of money in other forms of energy and not enough incentives to go full solar. When I speak of incentives I mean the sum of all the factors that could make full solar, today, less profitable than other forms of energy.\n\n\n\n\n",
"Many of the comments highlight the logistical issues with this but there are also environmental impacts as well.\n\nWhile many people think of places like Arizona as just massive deserts with nothing living there, deserts are home to many different flora and fauna. Here's a [link](_URL_1_) some of the various wildlife present and another [link](_URL_0_) showing the variety of the different types of desert ecosystems in Arizona.\n\nTo make room for a solar farm you'd have to remove a large portion of these ecosystems to generate even enough electricity for a single city let alone the whole world.\n\nThere are definitely logistical issues with covering the desert with solar panels but it would also be the same as removing a forest to make room for that level of energy production.",
"Solar engineer here. Let me explain some of this that's been covered by some people already.\n\n__Why Not Solar In Deserts?__\nIf we are talking a new array away from people, someone has to lay out all of the infrastructure for it to deliver power to the grid. At the same time, someone also needs to figure out how to shut it down when the largest source of power on that power grid fails because pumping electricity into a powered down grid can have disastrous results. This is typically solved in home solar with a fast disconnect, in which if power to the home stops the array ceases function to help the main power company in the area get things going again.\n\nNext is maintenance on the panels. The thing about large constructions in remote areas or even out of the way spaces is that most companies that put something out there intend not to have to come back to it unless they absolutely have to. The issue with this and solar is panels may die, panels need cleaning, sun tracking mountings are expensive as fuck, and you'd have to pay for all the equipment and people to facilitate taking care of all this. The same fast disconnect isn't a great solution at this kind of scale either. Large power systems like this require a lot of extra engineering and planning and sometimes implementing solutions that don't even exist or cannot just be found off the shelf. (Gonna also drop that you'd have to landscape the desert unless you find a really nice flat spot and even then, you may want to have a leveler come through anyways.)\n\nUltimately, there is a lot that needs to be managed that just aren't realistic to manage. At the same time, anyone who puts an array out somewhere needs a way to make money off it. They probably aren't going to be able to get the power company to pay for large sums of solar power without it being discounted a lot. After all, if I was a power company I don't need to buy power from someone else. The city may not because they are already getting power from the already existing grid owner. Leaving you only able to sell to new developments and offer power along side the power company to homeowners, at which point, why aren't you just an extension of the power company? And the power company does not have an industry interest in solar because fossil fuel is a bigger money industry. (This statement is wrong, check out /u/Halfway_Bayesian [post](_URL_0_).) At the same time, your power needs to be as always available as a regular power company for emergencies and panels do not produce much at night.\n\n__Future of Solar then?__\nI honestly think that the future of solar right now is in residential. Most homes can hold enough panels on their roof to offset all of their electrical costs and for a pretty fair price (about the cost of a car, between $10,000 to $40,000. Consider pricing is on average, $3.50 per watt on a panel.) I've seen in just the last two or three years alone panels going from 225w panels to 290w along side batteries and even solar shingles. The technology is improving fast and we will see a lot more of it in the next few years. However keep in mind too, not every place in the world is geographically suitable for solar power. Locations too far North and too far South won't get great benefits from solar power. Neither would a place that you could essentially call a forest. Solar I don't believe sells well in Canada or states and countries along the same latitude as Washington or Oregon state. [Check out Huppie's post here.](_URL_1_) where they discuss solar at these more northern latitudes, I learned something new.\n\nTo put things in perspective, if you live in Utah with a good South facing roof, 8 modules of 290w are enough to offset 3,000-4,000 kWh of usage at your home. For a lot of small homes, this can be all you use for a year. A lot of solar companies offer their own maintenance services or even equipping an array with other necessities like \"critter cages\" to keep birds and squirrels out from under your panels. Otherwise, you may have a ton of fried birds under your panels. They get hot.\n\n__Problems that Face Solar__\nThe biggest issue with the solar industry for individuals is electrical companies because they are virtually untouchable. The reason is that they technically own the power grid and if the entire city depends on it, there is nothing that can really be done. A lot of power companies lobby to keep solar out as well. If you do some research, Nevada was a booming industry. Then Warren Buffet's Pacificorp, changed how solar customers pay their bill for having solar. Essentially, they put up a premium that brings your power bill to, still less than before, but not as much savings. On top of that, you're now also buying power from a solar company or paying for panels under a loan or lease. Pacificorp, claims that they lose millions of dollars per year on administrative fees and are recouping that cost from solar customers with this premium. Some electrical companies won't even allow residents they service to have a solar panel system.\n\nThere needs to be more policies for solar friendly developments and incentives for the industry. There are some, but there are also powers in the world that are cornering the market on power and do not want solar coming around because so far, solar companies are already undercutting profits from the grid owning electric company. I think there needs to be a lot more cooperation between power companies and solar companies rather than the electrical companies governing and restricting how power is being provided to consumers in an area.\n\nTldr: __Solar panels require a lot of maintenance, the idea itself has a lot of business and municipal policy issues, and these same issues extend to the entire solar industry. Its much more feasible for residential solar to be happening for society as these same problems tend to be cheaper when costs can be levied on a private customer.__\n\nIf you want to be the one to do that though, do it. ",
"We can and we will, but it requires time because of simple economics. Burning stuff is still cheaper (which will change), you can put burning power plants closer to places that need energy (which will not), and burning power plants take less space (which is often irrelevant due to deserts being huuuge, but will change anyway). Improvements in solar battery efficiency, and dwindling fossil fuel reserves bring us closer every day.",
"\"Ask your self why we are shutting down already operational and carbon free nuclear plants, but are willing to pay extra in taxes to build carbon free NEW renewables. It is stupid. And it ignores the facts of the grid and engineering. Solar cannot be used as abase load. And the technology for storage is more in its infancy than renewables are. And before we can really have any chance of renewables really supplying the whole of the grid, storage has to be solved.\"\n\nBecause Fukushima"
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"http://lftrnow.com/replacing-nuclear-with-solar-2/"
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"http://new.abb.com/systems/hvdc/why-hvdc/economic-and-environmental-advantages",
"https://www.sciencedaily.com/releases/2017/02/170209163838.htm"
],
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"http://arizonaexperience.org/land/az-habitats",
"http://geography5ecosystem.blogspot.com/"
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"https://www.reddit.com/r/explainlikeimfive/comments/5woe50/eli5_why_cant_we_just_cover_a_proportion_of_the/decu3tf/",
"https://www.reddit.com/r/explainlikeimfive/comments/5woe50/eli5_why_cant_we_just_cover_a_proportion_of_the/dect48o/"
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1zfgmi | why is youtube getting steadily worse? | try to click back to rewatch something? frozen, need to reload page
try to click ahead to skip crap? frozen, need to reload page
try to change video quality? ignores you until you reload page and then resets to the default quality anyway
spend 10mins trying to find the option to set subtitles and annotations default off? reset to default on once a month and rehide the options
not sure if its magic hindsight 20/20 vision, but i swear it used to be far FAR better than this shit | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1zfgmi/eli5_why_is_youtube_getting_steadily_worse/ | {
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"It's the \"not available on this platform\" that confuses me, why is a video watchable on a PC but not a tablet?",
"ALOT of legitimate users are being ghosted in the comments not by channels but by the google spam filter, if you comment too much now on youtube or reply to comments too much you may get ghost banned from every channel for a period as youtube thinks you are a spammer not matter what you are saying. Ghost banning means you can see your comments and replies but no one else can. Originally this was intended for channel owners but since the google+ merger and subsequent updates its now being used on entire accounts resulting in people thinking they are being ignored even if they had valid points or creative input to a subject in the discussions. To see if you are ghosted post a comment on youtube or google+ then log out and see if still there, suprisingly this is becoming more common and in reply to your question its rather simple, google bought youtube ",
"Why do the Ads load/buffer without any wait but as soon as you try to watch something you can't play it till it loads. :(",
"I'm sure there is someone who can explain it better but I'll try.\n\nYoutube uses DASH playback, it loads the video you watch in chunks. When you watch till a certain point, they will load the next chunk. What it does is save Youtube bandwidth so they won't waste it when you buffer the whole video but only watch part of it. At least, this is to my knowledge on how the new Youtube buffering works. \n\nWhat you can do is install Youtube Centre on your browser to disable DASH playback but you will be limited to a maximum video quality of 720p, which I find rather acceptable. That way, you can buffer the entire video then watch it, instead of having to pause and let the video load every few seconds when on a bad internet connection.\n\nI am no expert but this is what I could gather. I hope it helps!"
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3ao2b6 | please explain to me how prisons are allowed to be privatized, and what their purpose is compared to public (as in, are they better for prisoners, better for the state, etc?) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ao2b6/eli5_please_explain_to_me_how_prisons_are_allowed/ | {
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"Prisons are allowed to be privitized because local and state governments passes laws saying they were allowed to be privitized.\n\nThe purpose was an effort to reduce the incredibly high cost of prisons (and lots of corruption by people who have financial gain from it--which from any perspective or stance on the situation cannot be ignored). It hasn't really reduced costs, conditions are questionable, but people (private prison companies) are making shit tons of money off of it from the government."
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41wsgf | why is vanilla considered the "neutral" or "natural" ice cream flavour? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/41wsgf/eli5_why_is_vanilla_considered_the_neutral_or/ | {
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"It was so good, so versatile and so available that it became boring. It was overexposed, overdone and copied poorly so often and for so long that the general population forgot how good it really is when done well. \n\nIt got buried under a mountain of its own success. ",
"When I was in Poland, I had some really neutral cream flavored ice cream. I thought it was awesome.",
"Artificial vanilla flavoring was synthesized in the 19th century, so presumably vanilla ice cream was cheaper to make than other flavours which required fresh fruit or chocolate and whatnot. \n\n\nAlso, it doesn't hurt that it tastes amazing. ",
"It seems to me that vanilla is a flavour that doesn't draw loads of attention to itself, especially when mixed with sugar and cream. It adds to the complexity of the flavour profile so that it tastes balanced, but there no question that chocolate, mint chip, or OP's Mama Fudge Xplosion are flavours which really call attention to themselves. Vanilla just tastes like a richer, deeper version of plain iced cream.",
"Most shops that make their own ice cream buy \"base\" in bulk, which is an \"unflavored\" ice cream (no vanilla). Base then has flavorings (including vanilla) added to it, but many \"white\" ice creams are NOT actually vanilla flavored, but made of unflavored base. ",
"It's a flavor which can be mixed with other flavors consumed with ice cream, be it mixed in or a topping. You can mix in chocolate sauce and get something resembling chocolate ice cream, mix in sweet fruits, nuts, sprinkles, chunks of dough, whatever... and any time you think \"that was a bad idea\", it's the ingredient's fault, not the vanilla. Add to that the relative whiteness and thus even the resemblance to a blank canvas... why wouldn't it be considered neutral, at least without \"plain\" presented as an option.\n\nPlain yogurt, on the other hand, is quite different from vanilla yogurt, as not only is it unflavored, it is also unsweetened.",
"Bit off-topic here, but vanilla is black, so why are vanilla products always white?",
"I've been wondering about why there is no plain vanilla-less ice cream sold as a shelf product ... "
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3gtlt1 | how is it that during wwii, many european landmarks like the eiffel tower or westminster abbey survived years of bombings? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3gtlt1/eli5_how_is_it_that_during_wwii_many_european/ | {
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"You don't bomb randomly, you normally aim for industry and infrastructure. Also many buildings were heavily damaged and restored afterwards.",
"The War in Europe was mainly fought to the east of Berlin (Central and Eastern Europe - including Russia). There was no real bombardment of Paris and only limited on London. Eastern Europeans cities on the other hand were usually leveled to the ground.",
"To answer from a more military-centric standpoint. Many landmarks, from both sides had advantages to be left alone. For incoming bombers, landmarks were often used as a navigation point of reference. Navigating and dropping bombs on target was super hard in WWII, and you could be wildly off and it may take dozens of missions to hit a target.\n\nBut hey, what if from the sky, I can see and landmark, and easily-and quickly- know where in relation to that my bombs were going, or where i was and what direction(s) I need to fly? Boom, sounds like a great reason to keep them.\n\nOne of the often given examples is in Munich, which was heavily bomb, [but the towers of the Frauenkirche](_URL_0_) were left there and used as a guide for allied bombers, and [even after the bombings](_URL_1_)",
"The Eifel tower mostly survived because Paris wasn't bombed systematically from the air during the war.\n\nLondon did get bombed, but the volume was far less than in other places.\n\nSome landmarks did get destroyed either by accident or on purpose while others were deliberately avoided. Some were even used as guides by bomber pilots to tell them were to drop their bombs.\n\nHere is a picture of the [Coventry Cathedral](_URL_1_) in the aftermath of German bombings.\n\nHere is a picture of the famous [Cologne Cathedral](_URL_0_) being one of the few intact buildings left standing.\n\nHere is a picture of the [Geächtniskirche](_URL_2_) in Berlin as it looks today.\n\nSome of the worst destruction of heritage sites probably happened in Malta during the war.",
"The French surrendered before the fighting reached Paris, so there was no bombing of it at the beginning of the war. The Germans marched in and took over, and the beauty and glory that is Paris became their treasure. They therefore wanted to preserve monuments. But when they were losing and the fight came to Paris, Hitler did order the German commander of Paris, General Dietrich Hugo Hermann von Choltitz, to destroy the city. If Germany couldn't have it, then no one would. Plus Hitler HATED the French and would have enjoyed destroying Paris. But Choltitz defied Hitler's order and instead surrendered the city to the custody of Free French Forces. He did it because it would have no military value, he liked the French people and the city, and he didn't want to go down in history as the man who destroyed Paris. Nevertheless, a number of beautiful buildings were destroyed between Normandy and Paris, like a church in Rouen.\n\nAs for Westminster Abbey, it was dumb luck that has kept it preserved. Initially, Germans sought to bomb only strategic targets, but with bad aim they bombed a residential area, and then started to do it deliberately. They hit Buckingham Palace and damaged it a bit, and they also hit St. Paul's Cathedral, but it still stands.",
"Plenty of London landmarks such as Westminster, Buckingham Palace and St Paul's were hit, they repaired them after the war. France was pretty much spared because they surrendered so quickly - most of the damage in France happened after D-Day (for example Caen was almost completely destroyed by allied forces because they didn't want to be held up with street-fighting early in the liberation of Europe)"
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e74v45 | how do companies benefit from giving [x amt.] dollars off coupons? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e74v45/eli5_how_do_companies_benefit_from_giving_x_amt/ | {
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"The business issuing the coupon hopes that people who receive them might make a purchase they might otherwise not (thus earning some revenue), and/or to choose their product over the competition (possibly building loyalty to the product/brand).",
"Normal product markup is about 50% for most companies. That depends obviously on the product (profit margin is much higher on say, a t shirt than a new car). Providing coupons obviously cuts into that profit margin some, but coupons are one time use. The hope is that next time you need whatever item you will continue to buy that brand- and you'll pay full retail price.",
"It compels a purchase. A company makes slightly less when you use the coupon, and nothing when you don't buy it at all."
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ezajbp | exactly how does a tesla valve work? | I saw an image of a Tesla valve and decided to investigate how it works. When I did a search, what I found was a lot of engineering technical terms and more questions than answers. Hopefully I can get this answered. Thanks in advance
Edit: Corrected my auto-correct | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ezajbp/eli5_exactly_how_does_a_tesla_valve_work/ | {
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"Oh damn tesla valves are genius. This video will probably explain it better than I can: _URL_0_\n\nThe idea is that gas will always follow the easiest path it sees, ie, forward. In one direction, there's only one forwards each time a junction is found, so the gas just goes down there. However, going the other way, every junction has two possible \"forwards\" which look identical to the gas, so it splits half and half down each path, then when it collides with the stream that went down the other path, it creates turbulence which slows the procession of gas down."
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3nzx26 | can the us declare bankruptcy? | If this is a yes, how would they go about it and how badly would it hurt the world economy?
If this is a no, why not? If there's a debt, should they not be allowed to file that bankruptcy? Seeing how business can do it fairly easy, shouldn't a country be able to as well? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3nzx26/eli5_can_the_us_declare_bankruptcy/ | {
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"Yes, the US effectively can. It would be very, very bad for the world economy. The US government (and US corporations and even individuals by extension) would face massive increases in borrowing costs, which would cause a huge recession which would be overwhelmingly likely to spread throughout the globe.",
"Can they? yes. \n\nWill they? no.\n\nThe US government owns the printing press that prints dollar bills, at worst case, they can just print a ton of money and pay off creditors. Doing so would destroy the value of the US dollar. \n\nNot paying off debt would destroy the credit worthiness of the US government. Plenty of countries have voided past debt or changed the terms of the debt, both of which destroy the credit rating for decades. ",
"By \"can\" you actually mean \"can without being screwed\".\n\nA individual filling for bankruptcy mean that the government takes control of the your assets and comes to a conclusion rather than continually taking your income to pay your creditors.\n\nNo one has the ability to seize the income of the United States. So sure we can decide not to pay. And others can either attack us over it, or refuse to do business with us again.",
"There's no particular reason the US would ever need to declare bankruptcy. Money can always be issued. I'd even go so far as to suggest this would only have a minor effect on the value of the dollar, because US bonds are monetized and traded like currency. The money supply is effectively expanded when debt is issued, not when it is paid off, so paying off the debt with printed or electronically-conjured money would drive inflation through increased liquidity more than anything else.\n\nThe US can default on debt through political gridlock, though. This almost happened a few years ago with the infamous \"debt ceiling\" standoff and subsequent credit downgrade.",
"Bankruptcy essentially means that the government is going to refuse to pay back its debt. So yes, it can declare bankruptcy and anybody still with US debt will be out of luck.\n\nHowever, there is no court system to force the US to sell assets to cover its debts. Although, it could lead to countries forcibly taking US assets in their countries in order to cover their loses.",
"Sort of, although 'bankruptcy' is the wrong term. A sovereign state cannot declare bankruptcy because there is no-one to declare to. Instead they could announce they would fail to honour their debt obligations and default on the debt. This would cause massive shockwaves throughout the global economy since US debt is considered one of the safest investments possible, and would wipe out a huge amount of wealth both in the US and around the world. For instance, about 30% of US debt is held by foreign investors (China and Japan being the largest sources), and 20% is held by domestic investors. The remaining 50% is actually owed to the US Federal Reserve.\nThe US is in a very unique position because of the dollar's hegemony, so they wouldn't have an economic reason to default on their obligations (the only risk factor would be political grandstanding around the debt-ceiling).\nHowever, for other sovereigns, the reason they choose not to default (even though they can), is the fear of being locked out of borrowing in the future. Creditor-led restructurings of debt are much more common."
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5rns6z | why is it that while at work, i feel like i have to constantly use the bathroom, but at home at night, i rarely do? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5rns6z/eli5_why_is_it_that_while_at_work_i_feel_like_i/ | {
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"Two ideas:\n\n1. You're staying hydrated better at work. I know I did when I worked in an office.\n\n2. You're less stimulated and more aware of the need, so you have a lower threshold for actually stopping what you're doing and going to the bathroom.\n\nIn short, I know the title says biology, but I doubt the actual answer is biological."
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2yeu36 | why do people go to college to get an art degree? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2yeu36/eli5_why_do_people_go_to_college_to_get_an_art/ | {
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"How much can you improve on your own? I could spend all day for years trying to teach myself to play the trumpet, but I'll only improve bit by bit. If I were to work with a professional trumpet player every day, I'll get better much faster. Colleges have dozens of art professionals who will help you and direct your practice.\n\nBut there's a lot more than just practicing art. Learning the history, the theory, the famous painters all gives you inspiration and knowledge as a base, which speeds up development as well. Knowledge of several different styles and techniques can help you find your place in a modern style or create your own. There's a lot more to every art than just learning how to do it and doing it over and over.",
"1) To get training from artists. Society has mostly done away with the apprentice model of learning things and so if people want to learn art they either have to stumble on their own and develop their own techniques or they have to convince an existing artist to teach them independently. \n\n2) Certain universities, and conservatories come with the weight of famous graduates and known high standards behind them. Think of Julliard. This goes a very very long way in getting people jobs. \n\n3) Many wish to teach the fine arts to others. To do this most places require some kind of degree or accreditation if you are doing so as a private tutor, and require full bachelors and at times masters degrees if you are doing so in an actual school. ",
"Art degrees generally don't teach you how to make art, they teach you how to judge art. While they do teach you different techniques, it's so you can recognize them in the future and be able to better understand a piece.\n\nIf you want to paint, you can go ahead and paint. But if you want to appraise art, if you want to acquire art, if you want to run a gallery, you need to be able to look at the piece and see the technical work put in behind it."
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txqo3 | the point of viruses. | Not computer viruses, I'm talking real-life viruses, why do they exist and what's the point of them?
**EDIT**: Ok, it sounds bad asking what the point of them is, what I meant to say was: What do they gain as a life form when they infect others? Why do they do it? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/txqo3/eli5_the_point_of_viruses/ | {
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"The point? Life doesn't really need a point. It simply exists because it can.",
"What's the point of human beings?\n\nOr orangutans?\n\nOr fish?\n\nLife forms evolved varied survival strategies. Because a virus is a very different life form from you does not make it less significant.",
" > What do they gain as a life form when they infect others? Why do they do it?\n\nThey gain more of themselves. Reproduction is the goal, same as basically all forms of life. If their genetic code didn't encourage them to reproduce, there wouldn't be any more of them.",
"Okay, okay let's rephrase the question as something like \"why do viruses infect other organisms rather than just going their own way in the world? What survival advantage does that give them that caused them to evolve the way they did?\"\n\nI don't have a perfect answer for that but generally a parasitic organism is able to be more energy efficient by offloading some of its requirements onto *somebody else.* In other words a tape worm doesn't have to go around hunting or scavenging for food. It just sits there inside you and lets *you* do all that work, and then steals the results of your energy expenditure.\n\nI would guess that there's something kind of similar to that going with viruses at a more chemical level. If nothing else, existing inside a mammal or bird species means a relatively predictable and stable environment.\n\nThat's not meant to be a complete answer by any means, but based on the answers so far, even a phrasing of the question that doesn't invite snark is a step forward.",
" > What do they gain as a life form when they infect others? Why do they do it?\n\nBecause things like them that didn't do it don't exist anymore. It's not a choice, or a goal. it's just inevitability. If thing A can duplicate itself and thing B can't, eventually all that will be left is thing A."
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l56iq | why the us has troops in germany and japan. | I just heard about it. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/l56iq/eli5_why_the_us_has_troops_in_germany_and_japan/ | {
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"I can only answer you the german part. As far as I know, most of the US troops in germany are from [EUCOM](_URL_0_). As the US already had bases in germany after the second world war, they just kept part of them as strategic points for all europe based actions, which are mainly NATO missions. As germany is very central in europe, it's perfect to transport troops or other goods to or from irak. The wiki-article about [Ramstein Air Base](_URL_1_) is also a good read, as it points out what tasks this largest air base outside of the US has. I don't know though why you specifically ask about japan and germany, as the US have military all over the planet.",
"Many of these bases are holdovers from WWII. They are strategic hubs for transportation and such. Also if anything were to kick off, we are pretty much every where. It isnt limited to Germany and Japan though. There are alot more. Spain, Guam, Italy, England, Africa, S. Korea (still technically at war) Philipinnes, south america, as well as central america, and antartica. Probably missed a few as well",
"Actually its due to the Cold War. Both Germany and Japan had unfavourable relations with russia, japan wasnt best liked on the asian mainland and both saw large amounts of americans spending money a good way to repair their economies without having to make seperate deals.",
"I can only answer you the german part. As far as I know, most of the US troops in germany are from [EUCOM](_URL_0_). As the US already had bases in germany after the second world war, they just kept part of them as strategic points for all europe based actions, which are mainly NATO missions. As germany is very central in europe, it's perfect to transport troops or other goods to or from irak. The wiki-article about [Ramstein Air Base](_URL_1_) is also a good read, as it points out what tasks this largest air base outside of the US has. I don't know though why you specifically ask about japan and germany, as the US have military all over the planet.",
"Many of these bases are holdovers from WWII. They are strategic hubs for transportation and such. Also if anything were to kick off, we are pretty much every where. It isnt limited to Germany and Japan though. There are alot more. Spain, Guam, Italy, England, Africa, S. Korea (still technically at war) Philipinnes, south america, as well as central america, and antartica. Probably missed a few as well",
"Actually its due to the Cold War. Both Germany and Japan had unfavourable relations with russia, japan wasnt best liked on the asian mainland and both saw large amounts of americans spending money a good way to repair their economies without having to make seperate deals."
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2ur4qz | why does relaxing/removing drug laws lead to a decrease in drug use? | Time Magazine just published an article calling the complete decriminalization of all drugs in Portugal a "resounding success", showing decreases in usage of most drug types, and one of the key points I've taken away from coverage of the topic of marijuana in Colorado, is that use of the drug by teenagers is down.
The problem is that none of these articles ever explains *why* this happens. What are the mechanisms by which (presumably) increased availability results in decreased usage? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ur4qz/eli5_why_does_relaxingremoving_drug_laws_lead_to/ | {
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"It's complicated, but two factors that seem key are:\n\n#1: Drugs are expensive and profitable to sell because they are illegal, not because they are expensive to produce. Making them legal reduces their profitability, so dealers are likely to move to other activities, reducing supply.\n\n\n#2: The forbidden fruit angle. When something is forbidden, it becomes a way for people (particularly young people) to demonstrate their independence and reject society. When marijuana is accepted by the mainstream culture, it can no longer be considered a rebellious act.",
"Because harsh drug laws start people down a spiral. You get arrested, potentially lose your job, maybe spend some time in jail, and when your charges are done you don't have much else to do than go get high, repeat cycle. If you give people reasonable social alternatives, maybe drugs don't feel like the only option\n\nAnd with teenagers, at least some of the appeal is the forbiddenness of it. ",
"The bulk of the decline in Portugal is demographics. Drug abuse is primarily an issue for young people, and Portugal's youth demographic has shrunk over the past decade at unprecedented rates.\n\nMuch of the remainder is merely tinkering with definitions. A person living on the streets shooting heroin is a 'drug abuser'. A person visiting a Methadone clinic isn't.\n\nSimilarly, the cause of the decline in teenage marijuana use in Colorado may be the result of many factors - but it almost certainly has nothing to do with drug legalization since the trend started years before the law was changed.\n\nSo relaxing/removing drug laws doesn't actually lead to a decrease in use - a far more thoroughly analyzed situation (tobacco use) actually demonstrates the opposite. What it does do is allow the use to be managed more effectively by bringing it into the public light."
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3149ts | i assume seeds have no scent, and birds can't smell them. how do they ever stumble upon bird feeders? | My lady friend and I just hung a bird feeder outside of our window. How do birds locate the seed? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3149ts/eli5_i_assume_seeds_have_no_scent_and_birds_cant/ | {
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"_URL_0_\n\nAccording to this article, they primarily use sight to find bird feeders, and then call other birds to the food source.",
"Seeds do have scent, and birds can smell them. Why would you assume otherwise?",
"I don't know if birds can smell or not, but if you stick your nose in a bag of black oil sunflower it definitely has a smell. And the raccoons can smell them for *miles*.\nninja edit: schpelling"
]
} | [] | [] | [
[
"http://www.straightdope.com/columns/read/2208/how-do-birds-find-bird-feeders"
],
[],
[]
] |
|
e3sfts | what is an induction motor? | This is Wikipedia's definition - _URL_0_
'An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding'
I know that a motor is a machine designed to convert one form of energy into mechanical energy(car engine being a motor)
Can someone give an ELI5 explanation for this motor and how did Nikola Tesla made this discovery? What were motors like before this discovery? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e3sfts/eli5_what_is_an_induction_motor/ | {
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"text": [
"Normal motors are DC motors, synchronous AC motors, or universal motors. Induction motors are unique in that they provide torque at a wide range of RPMs while requiring no contacts that can wear out. Metals tend to resist moving magnetic fields. If you move a powerful magnet quickly past some metal, the metal will get tugged along. Induction motors use electricity to create a rotating magnetic field around a piece of metal, and the metal tries to spin with the field.",
"As a navy trained electrician, your definitions are backwards IAW my training (which was several years ago, admittedly). Cars have ENGINES and people who call them motors are incorrect and sound like rednecks. Motors specifically use electromagnetism. That's a semantic argument, but still it exists.\n\nMotors are just magnets pushing against each other. There are several things to understand about how this comes to be, especially with induction motors.\n\n1 - **\\[electrical\\] current in a conductor always produces a magnetic field.** The direction and intensity of that field are proportional to the current (More current=bigger magnet, and the direction of current flow determines magnetic North and South poles).\n\n2 - **AC** \\- or alternating current, switches directions (hence the name). When AC peaks, lulls, and switches direction, the resulting magnetic field ALSO peaks, lulls, and switches directions.\n\n3 - **generator action** (the production of electricity) requires a magnetic field, a conductor, and relative motion between the two. EITHER the conductor can move, OR the magnetic field - it does not matter which, so long as there is a relative motion between them.\n\n4 - **motor action** (the production of movement) requires a current-carrying conductor (which produces magnetic field A) in an already existing magnetic field B. The magnetic fields will attract and repel each other.\n\nWith an AC induction motor, AC current is run through the pole pieces, which are arranged in a staggered order so that instead of simply pulsing, a *rotating* magnetic field is produced. This *rotating magnetic field* results in **generator action** and ***induces*** a voltage into the rotor windings. Now we have AC supplied to the pole windings AND a an induced current in the rotor windings, so now we have the conditions for **motor action** (listed above). The *induced* magnetic field in the rotor follows the AC-made *rotating* magnetic field in the pole pieces.\n\nTHIS IS AWESOME because there does not need to be any physical electrical connection to the rotating parts.\n\nBecause there needs to be a *relative motion* between the AC rotating field and the rotor windings for this to work, there is a difference between the speed of the rotor and the speed of the AC rotating field. That is why induction motors are \"Asynchronous.\"\n\nOther motors use slip rings (ac) or commutators (dc) and brushes to supply electricity from a power source directly to the rotor - so there is no need for induction. This also means that they can move just as fast as the rotating magnetic field and be \"synchronous.\"\n\nSlip rings are just smooth rings connected to either end (+ and -) of the rotor windings. Commutators are basically the same thing, but use multiple segments wired in an order to *mechanically* convert DC/AC in DC motors. (best look up a video for that one, tough to explain without imagery).\n\nBrushes are just conductors that \"brush\" against these slip rings or commutators (because fixed wires would get twisted by the motor's movement)- they are usually made of a powdered conductive material embedded in a carbon cake. The brushes are wired to the power supply on the back side. Brushes are also wear parts that need to be replaced periodically (another advantage for induction motors).\n\nIDK Tesla's exact thought process and I doubt that anyone does. But he was brilliant and imaginative. I believe he was able to successfully *visualize* the \\[invisible\\] magnetic fields, and then predict the interactions of each magnetic field with each other magnetic field.\n\nI imagine that most people before Tesla worried more about where the wires were rather than where the magnetic fields were."
]
} | [] | [
"https://en.m.wikipedia.org/wiki/Induction_motor"
] | [
[],
[]
] |
|
5qhf3k | people when they get old seem to be shorter than when they were young with at least a few inches. why?? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5qhf3k/eli5_people_when_they_get_old_seem_to_be_shorter/ | {
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"text": [
"Besides older people who 'stoop' or are unable to stand up completely straight due to arthritis and the such, the cervical discs in between each vertebrae get compressed as people get older. Each disc gets a little smaller, but with like 16 discs, even 1/16th of an inch per disc will shrink you by an inch.. "
]
} | [] | [] | [
[]
] |
|
31l5j0 | why and how do i sometimes sneeze when i'm turned on? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/31l5j0/eli5_why_and_how_do_i_sometimes_sneeze_when_im/ | {
"a_id": [
"cq2patv"
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"score": [
2
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"text": [
"Nobody knows. [Sexually induced sneezing](_URL_0_) has been known of since 1897, but about all that's known is that a given person will tend to sneeze at the same point - so some people sneeze when they start getting turned on, some sneeze after orgasming. It might have something to do with the central nervous system (i.e. your brain and nerves that carry messages around your body, maybe some of those messages get sent to the wrong place), or it may be related to the fact that you have erectile tissue in your nose."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Sexually_induced_sneezing"
]
] |
||
q6s1b | continued fraction arithmetic | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/q6s1b/eli5_continued_fraction_arithmetic/ | {
"a_id": [
"c3v6ow5"
],
"score": [
2
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"text": [
"What about it?"
]
} | [] | [] | [
[]
] |
||
1ytct4 | how or why is it legal for companies like comcast and time warner cable(usa) or rogers and bell (canada) to have such obvious control over almost the entire market? | I get the whole concept of oligopolies being legal whereas monopolies are not (at least in Canada - or as my brief understanding of business and economics) but surely an exception should be made for such an extreme case of an oligopoly which may as well be considered a monopoly?
Thanks | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ytct4/eli5_how_or_why_is_it_legal_for_companies_like/ | {
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"text": [
"Because they (for the most part) write the very regulations that are meant to control them. Those regulations conveniently suppress competition, thus allowing the remaining large players to enjoy their legally protected monopoly.",
"The last mile.\n\nWhen they first started running cable TV lines it made sense to give each of the cable company's territories so you didn't have multiple vendors pulling lines through everyone's back yards. The smaller cable companies got bought out by larger ones later.\n",
"In the US, it is legal to be a monopoly, it is just not legal to abuse monopoly power. Microsoft, for instance, was declared to be a monopoly 10 years ago but wasn't broken up. ",
"u/lokiorin has it mostly right.\n\nIt is extremely expensive to lay the \"plant\" (underground cabling) to provide service. Low estimates assume $10,000 per city block. \n\nIf multiple companies existed in a single market, each one would have to divide their market share between their competitors, and in those markets providers either A) have to raise their prices through the roof in order to recoup their initial investment or B) go out of business because they can't repay their loans (oversimplification - this is ELI5 after all).\n\nBecause cable TV is deemed a \"necessary service\" (they provide weather and security (orange) alerts, etc) by the US Government, it doesn't do anyone any good to have them priced out of the market or constantly going out of business.",
"We need a Teddy Roosevelt.\n\n_URL_0_",
"At best its a legal grey area, but since these huge companies are funding and influencing policy, they really do have quite a large share of the control over how and by whom they are regulated.\n\nUltimately its the conflicts-of-interest that are the problem. For example, the guy who decides what is and isn't acceptable in our food via the FDA, was formerly a high level executive at Monsanto.\n\n\n"
]
} | [] | [] | [
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Presidency_of_Theodore_Roosevelt#Trust_busting"
],
[]
] |
|
206jhf | what are the scientifically proven causes of cancer? | I feel like the majority of what I hear is speculation. What have we learned so far that we KNOW causes cancer? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/206jhf/eli5_what_are_the_scientifically_proven_causes_of/ | {
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"text": [
"That's a tough one to answer, largely because we are now discovering that there are many manifestations of cancer.\n\nThis is very much a layman's definition, but in short, we can say that cancerous cells are cells that have mutated in such a way that they do not perform their usual task within the organism, but which also are not so mutated as to prevent the cells from growing and reproducing.",
"Cancer is a malfunction in the cell that triggers the \"I need to die mechanism.\" As there are many causes for cancer, as there are many types of cancer, its hard to pinpoint one specific cause. \n\nSkin cancer is caused by radiation causing a mutation within the cell, these cells forget to die and then produce other cells with the same mutation. This leads to a tumor and why on medical shows people are often freaking out about \"getting it all.\" In reality the radiation/chemo that you under go would shrink/remove the remaining cells",
"Generally speaking, cancer occurs when there is uncontrolled cell growth. Normal cell turnover is a highly regulated process with multiple checkpoints that ensure that abnormal cells die and normal cells live and grow up until a certain point. There are many, many genes that control these processes. In the majority of cancers, multiple genes need to become mutated. This is known as the [multiple-hit theory of cancer](_URL_1_).\n\nSomething that causes cancer, which is called a carcinogen, is something that promotes these multiple mutations to occur. There are many known carcinogens, but most of them cause some sort of damage to cells. This damage prompts normal cells to replicate as part of the healing process. Whenever cells replicate, there is a small but real chance of replication error, where the DNA isn't copied 100% correctly. However, all it takes is one cell to become cancerous and replicate itself, in order to set the stage for cancer. If there is repeated exposure to damage over time, and millions of cells are replicating, this small chance of DNA replication error becomes a real possibility.\n\nIt is also important to remember that just because something is a known carcinogen, such as smoking, not everybody who smokes gets cancer. Smoking certainly is an important risk factor because of all the damage it causes to the native tissue. It creates a milieu that predisposes an individual to cancer, when compared to normal, healthy tissue. However, for cancer to develop, the correct mutations still need to occur, which is still a matter of chance, even if the odds are increased.\n\nTo more directly answer your question, the American Cancer Society has a list of known and probable carcinogens: [_URL_0_](_URL_0_)"
]
} | [] | [] | [
[],
[],
[
"http://www.cancer.org/cancer/cancercauses/othercarcinogens/generalinformationaboutcarcinogens/known-and-probable-human-carcinogens",
"http://en.wikipedia.org/wiki/Knudson_hypothesis"
]
] |
|
1qmm6c | what actually happens to the body during chemo and radiation treatments? | My father was recently diagnosed with cancer of his lymph nodes, and is currently going through chemo and radiation. He's explained a little bit of what the effects on his body will be, but he didn't tell me everything because he doesn't want to scare me.
I don't want to be surprised by any changes the next time I see him, so can you tell me what actually happens? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1qmm6c/eli5_what_actually_happens_to_the_body_during/ | {
"a_id": [
"cdeeeh3",
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3
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"text": [
"Radiation if used properly can limit the side effect, but basically it targets the tumor with a concentrated amount of radiation that is toxic to the cells and kills them.\n\nChemotherapy is the scorched earth of cancer treatments. It's one of the most effective, but it is brutal. Chemotherapy is basically using chemical agents to kill cells in the body, but the chemicals do not discriminate between healthy and cancerous. I also think it slowly the replication of new cells, which causes hair loss. The chemo destroys muscle cells, which is why they give steroids.\n",
"Chemo:\n_URL_1_\n\nTL;DR; Chemo works by poisoning the body carefully. The idea is that since cancer cells grow and divide quickly, they take up more of that poison quickly and die while other cells don't take in as much generally survive. Chemo just generally kills the cancer cells more than normal cells.\n\nRadiation:\n_URL_0_\n\nTL;DR;\nRadiation works by concentrating energy on a tumor and destroying the DNA in the cancer cells so they can no longer divide. Radiation can be focused kind of like a magnifying glass so that the focal point is in the tumor and the surrounding tissue is exposed to less intense radiation. Less intense radiation means that the cells not in the focal point should have a much lower chance of having their DNA messed up."
]
} | [] | [] | [
[],
[
"http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/radiation/understandingradiationtherapyaguideforpatientsandfamilies/understanding-radiation-therapy-how-does-radiation-therapy-work",
"http://www.cancer.gov/cancertopics/coping/chemotherapy-and-you/page2"
]
] |
|
or3zk | why is business broadband much more expensive than residential? | At AT & T, for instance, 3 MB download is $38 / month, whereas, a similar plan (with just a dynamic IP) is $55/mo. What's up with that?
_URL_0_
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/or3zk/eli5_why_is_business_broadband_much_more/ | {
"a_id": [
"c3jd8qj",
"c3jf7ob"
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"score": [
10,
4
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"text": [
"Usually business connections have service and connection guarantees. For example, AT & T might promise that your business will get X speed for 99.999% of the month, guaranteed, or something. They will also make service calls with increased priority.",
"It's mainly priority and better service.\n\nWhen your company has problems you have a direct line to more experienced technicians instead of having to call and wait for ~30 minutes on a \"regular\" queue. Most companies also have SHDSL which has the same upload and download speed.\n\nIf you have a company plan and your internet goes out it's usually solved on the same day/hour, whereas if you have a residential the same problem might take a couple of days to fix.\n\nSource: I work for an ISP company."
]
} | [] | [
"http://businessesales.att.com/dyn/dyn/products/matrix_internet.jhtml?SoHo=true"
] | [
[],
[]
] |
|
4h3h3v | how do the battery meters in phones/laptops/other electronics 'adapt' to changing battery life as a device ages? | For example, a phone with a 5-hour battery life decreases to having a 2-hour battery life after 1000 charging and discharging cycles. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4h3h3v/eli5how_do_the_battery_meters_in/ | {
"a_id": [
"d2n3ntq"
],
"score": [
3
],
"text": [
"Short answer - badly.\n\nlonger answer - they monitor the amount of energy that they are using and cross reference it with the measured battery voltage. If the battery voltage gets low enough that it's a good assumption that it's nearly dead, then the device re-calibrates its own estimate of what the capacity is."
]
} | [] | [] | [
[]
] |
|
66h2wx | liberalization in terms of economics and trade | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/66h2wx/eli5_liberalization_in_terms_of_economics_and/ | {
"a_id": [
"dgioulk"
],
"score": [
3
],
"text": [
"It depends on what type of liberalism you are referring to. There is classical liberalism, which would be better known as libertarianism today. Classical liberal economics encourage minimal regulations and free trade, as well as low taxes and virtually no government market interference. Modern liberalism, which would be more in line with the left wing parties like labour party in the UK, the democratic party in the US, and similar parties, is different. Economically, modern liberalism encourages higher taxes, higher government involvement in the market, more regulation, and less support for free trade."
]
} | [] | [] | [
[]
] |
||
5vy6f7 | if there's no air in space, that mean there should be little to no friction. why can't we just reach the speed of light by burning fuel in a particular direction for a while? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5vy6f7/eli5_if_theres_no_air_in_space_that_mean_there/ | {
"a_id": [
"de5se0m"
],
"score": [
3
],
"text": [
"This works for a while, but once you actually start to get close to light speed the usual f=ma physics stop working so cleanly.\n\nAt speeds that are an appreciable fraction of light speed (c) the energy required to continue accelerating begins to increase exponentially. Going from .8c to .9c takes far more energy than 0 to .1c, and the energy cost quickly becomes prohibitive.\n\nNo amount of energy in the universe can propel an object with mass to 1c, the equation approaches infinity.\n\nThere are also more practical problems like fuel load, acceleration time, stopping, ship controls, and impacting stray dust particles at relativistic speed."
]
} | [] | [] | [
[]
] |
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