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5rfioh | What is fair tax and flat tax? | Repost | explainlikeimfive | {
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"A flat tax is one of two things. 1) You charge the same exact tax to every person. So if the tax is $2000 you charge everyone $2000. 2) You charge everyone the same percentage. So everyone is taxed at say 30%. The issue with a flat tax is that it hurts the poor more than it hurts the rich, as there are no exemptions or deductions. Everyone owe a flat percentage of their income, and due to the costs of the government that percentage has to be set high in order to get the money it needs to function. A fair tax does not means anything specific, but I think you are asking about a progressive tax. In a progressive tax you take into account how much harm a tax will do to someone. So the poorest will pay no taxes, and you gradually increase the amount paid in tiers going up 5% or so per tier. This is more \"fair\" because it does less harm. $2000 means a lot when it is 1 months pay or more, but it does not really mean much of anything if it is 1% of your salary.",
"The term fair tax is subjective, depending on what is viewed as \"fair\", but I can tell you what a flat tax is. It is generally regarded as a system of income tax where everybody, regardless of income level or possible deductions under current tax law, pays the same percentage of their income as tax. It doesn't matter if you make 20,000 or 2 million, you both would pay whatever it is, be it 10%, 20%, etc. Under most versions of the flat tax, there are no deductions, reinforcing the idea of it being flat and unchanging. Currently in the US, and Europe, and most of the world, taxes operate using brackets, where different levels of income are taxed at different rates. Keep in mind, income is only taxed at the bracket it lies in. If I make 100,000, at the first 10,000 is tax exempt, I pay no income on that. However, income between 80,000 and 100,000 might be taxed at 25%. There are arguments for and against a flat tax, and whether it is fair. One argument for it is that since everybody pays the same percentage, and the same amount relative to income, its the most fair way of handling it. The argument against it is that affluent people have the ability to pay higher taxes without hurting themselves financially as much as the same tax would hurt a poorer person."
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5rkz3q | How did the first bilingual person learn a second language? | Repost | explainlikeimfive | {
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"This is basically how two people who have different languages learn to speak to each other (think two people on an otherwise deserted island). So, you start with basics. Point at yourself and say your name. Point at a coconut and say \"coconut\". Point at a fish and say \"fish\". The other person does the same in their language. You go from there and get more complex as you go. Fish becomes \"trout\" or \"bass\" and so on. Make a face when you taste something awful and say \"bad\". Now you are on adjectives. Keep going and eventually you will be chatting away."
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5rl1dp | The Doomsday Clock | Repost | explainlikeimfive | {
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"The Doomsday Clock is a symbolic clock used to represent how close we are to total nuclear war, which happens at midnight. It's promoted/managed by a committee of nuclear scientists in cooperation with other people. Every now and then they look at the current political climate, and international tensions between countries with nuclear weapons, and make a formal statement about the dangers of the current situation to continued human existence. They are concerned scientists worried that politicians, and most people, are not completely aware of the dangers and implications of global conflicts in an age where nuclear weapons exist. They do this by ceremonially adjusting the clock hands closer or further away from midnight, depending on how close they think we are from war. In short, it's a fancy ceremonial political statement by scientists using a symbolic clock, a criticism of how people do not take nuclear threat seriously enough."
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5rlzt3 | (and not American): What is "Alt Right" and why is it a big deal that their sub was banned? | Repost | explainlikeimfive | {
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"Alt right is a term used to describe a group of mostly young white males who feel that they have become disillusioned and lost in the shuffle. With things such as affirmative action, there has been a big push for women, minorities, and members of the LBGT community to have more representation in jobs and culture (certainly not limited to starring roles in movies and TV). Because of this push, these young white men feel that there's no place for them, that because they're not minorities or women, that their opportunities are diminishing. It's a big deal because they support racist, sexiest, and xenophobic ideals. They see those women and minorities as a threat to their livelihood. I mean, imagine having the feeling that you don't belong in society? You're going to find someone to blame. (This is the anecdotal part, please don't delete this comment) Personally, as a young-ish white male, I don't agree with the alt right movement but I completely understand where they're coming from. I will fully admit that there has been more of a push for inclusion, but the fact is that most of the jobs are still given to white males.",
"Internet neo-nazi's, white nationalists and white supremacists decided to rebrand themselves. If you listen to self-described alt-right people talk, they talk about how the white race is under attack, wanting a white homeland, and the 14 words (the big neo-nazi slogan). They give \"statistics\" on the IQ of different races. Neo-nazi's decided to rebrand themselves, and we let them. Some people are mad that reddit banned the group for doxing (revealing private/confidential information), calling it censorship and an attack on free speech. But reddit isn't the government, so it's not an attack on free speech. And it has the right to ban people for violating their ToS. Also, no one should have to host content on their site that they don't want."
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5rn990 | What is gaslighting and what are ways to tell if it's happening? | Repost | explainlikeimfive | {
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"Gaslighting is a form of psychological abuse where the abuser attempts to convince the abused that they are crazy. It is named after an old movie called *The Gaslight* where a wealthy heiress is seduced by a man who wants her fortune; one of the key parts of the movie is that she believes their gas lights are flickering, but he says that's not possible to hide the fact that while searching for her fortune he is disrupting the gas flow to the lights. The main sign of gaslighting is someone denying and lying about things you know to be true. Such as lying about things you've done or things that you've both experienced. Lying about other abuse is a common form of this in schoolyards (e.g. I didn't push you, you fell and I tried to catch you). This kind of abuse can also include other typical signs of psychological abuse like cutting you off from other people (causing you to become dependent upon your abuser), and making you feel stupid or unskilled.",
"Gaslighting: to manipulate (someone) by psychological means into questioning their own sanity. There is a list here of actions to be able to identify: They tell blatant lies. They deny they ever said something, even though you have proof. They use what is near and dear to you as ammunition. They wear you down over time. Their actions do not match their words. They throw in positive reinforcement to confuse you They know confusion weakens people. They project. They try to align people against you. They tell you or others that you are crazy. They tell you everyone else is a liar. [Source]( URL_0 )",
"If you feel normal away from someone, but insane when they have influence, that's a sign the person is intentionally, or unintentionally \"gaslighting\" you. Being unknowingly involved with unbalanced people makes us question our own sanity.",
"As others have said it's repeatedly lying to a victim until they question their own sanity. What I wanted to point out though is a famous (albeit fictional) example many people may not have realized. There is a famous Star Trek: The Next Generation episode (\"Chain of Command\") where Picard is captured and tortured. He is repeatedly asked how many lights his captor is shining. There are 4 lights, and he repeatedly tells this to his captor. But the captor always tells him he is mistaken. This is gas lighting. His captor is attempting to break Picard by getting him to admit there is a different number of lights than are actually present.",
"There was a gas lighting ELI5 a couple months ago and it had some really good explanations in it! I would search for it if you can, there were really good examples.",
"Ah, gaslighting. That's when someone is trying to make you think you're crazy by asserting that something they know to have happened did not in fact happen or vice versa. This is the worst thing you can do to a person with a mental illness. People with bipolar disorder, to use a disorder I'm familiar with, have bouts of paranoia. This can be triggered by psychotic episodes or major depressive episodes. They rely on those closest to them to \"sanity check...\" i.e. \"Am I perceiving these events correctly or am I misinterpreting what happened.\" If that person abuses that trust (\"this is all in your head!\") to win an argument, now there's less trust and instead of sanity checking the mentally ill person will just go with what they're perceiving.",
"Is the term gaslighting applicable if the offender is unaware they're doing it, i.e. They are suffering from BPD or some degree of NPD that results in them having revisionist memories?"
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5rq8z6 | How can they know what a black-white picture looks like in color? | Repost | explainlikeimfive | {
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"They just guess what colors should be there. For example we know what color the grass, sky, or skin color would be. Things such as a shirt, wall paper, or a book would just be our best judgement."
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5rqp3d | [Video Inside] Brick layers using domino effect which then shoots backward at 2x speed seemingly against physics to lay the bricks perfectly. | Repost | explainlikeimfive | {
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"It's not at all against physics. Here's a [video]( URL_0 ) that explains it with words *and* pictures, but since I don't wan't the mods mad at me for not explaining shit in ELI5, here's the explanation: When a brick falls, it pushes into the next brick, which pushes into the next, and so on. As brick A falls, it gets caught on the edge of brick B, which is caught on the edge of brick C, and so on. When brick Z falls, it doesn't hit something, so it can fall all the way. That frees brick Y to fall the rest of the way, which frees brick X, and so on, until brick A falls. Since the second round of falling doesn't need the bricks to fall as far to trigger the next drop, the return happens even faster."
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5rt68m | If a hummingbird is flying inside of a car and the car is moving but the hummingbird is simply hovering will it hit the rear window because it is not flying forward? When the car stops would the hummingbird hit the front windshield? | Repost | explainlikeimfive | {
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"It's as if you were standing in the train. At a constant speed you don't really feel anything, but when accelerating or decelerating you will feel the effects. So at constant speed the hummingbird can just hover, but when accelerating it will be drawn to the back and when braking it will be drawn to the front.",
"I wonder if a hummingbird would behave the same was as a helium balloon. The behaviour is a little counter intuitive. When you accellerate, the balloon moves FORWARDS in the car. and when you brake, it moves backwards. Why? Air pressure. When you accellerate, the air gently moves towards the back of the car. There is more pressure in the back, thus pushing very light floating things forwards. Vice versa for braking. Here's a video discussing it: URL_0",
"Thee hummingbird flys because it is pushing the air with its wings. All the air in the car is moving forward at the same speed as the car. Think of it the same way you would a fish swimming in a fish tank in the back of your truck."
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5ryp1m | Why is polygamy illegal? | Repost | explainlikeimfive | {
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"Because to the state, marriage is not about romance or fidelity; it is about a legal partnership. So they have regulated it to be uniform."
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5rzb5g | The Dodd Frank act. | Repost | explainlikeimfive | {
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"With the disclaimer that Dodd Frank is an incredibly complex law and it's hard to know all the details, here are some of the hightlights: * 1. instituted higher capital requirements for \"too big to fail\", including so called shadow banks like GE's finance arm * created the Volcker rule to limit proprietary trading(basically, you can't use peoples deposits to bet on stuff for your own bank), which can be risky * created a wind down procedure for big banks, so in the case of a crisis they won't threaten the rest of the URL_0 's a \"living will\". Basically, they have to simulate how what they would do if the economy tanked again, so they don't blow up and take everyone else with em. the of the above are audited/enforced by the Fed to insure compliance * created the CFPB- the SEC's sister orgnanization(the SEC only protects investors, not consumers), whose goal is to protect consumers (they were behind the big Wells Fargo fake account bust), mainly by consolidating regulations that were already on the books in various agencies, but not a priority * required derivatives to be traded through a clearing house to improve transparency (ie, to enforce standards so people know what they're getting into tldr: Tries to make banking safer by reducing the amount of risk that banks can take on, in order to avoid another 2008. edit: Sorry about formatting, lists are a pain in the butt."
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5rzeh7 | Why do we feel the urge to destroy things when we're angry? | Repost | explainlikeimfive | {
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"I'm sure someone can answer this better, but I can at least partially try, since I teach this to 5 year olds as part of a self-regulation program in my classroom! So, there's a part of your brain called the amygdala, which has to do with emotions. Basically, when you get angry, your brain perceives there is some sort of threat to you, and your amygdala triggers the impulsive fight or flight response. Things such as hitting someone or throwing something/destroying something when we're angry are examples of this. There's another part of your brain called the pre-frontal cortex that we call the 'wise leader'. This part is where reasoning happens, where you, for example, assess the situation that you're in and choose a course of action (such as using words when angry, instead of hitting/throwing). We teach this to young children because in order to think reasonably in the face of emotions such as fear/anger, you need to be able to 'calm the amygdala' so that your pre-frontal cortex can think things through before you react. Some people are better at this than others (young children, for example, but this skill in adults also varies greatly), but it's also something that can be taught and learned. 'Exercising the brain', if you will!",
"Probably has something to do with the evolutionary roots of anger, and it triggering a response that would have been advantageous. I imagine anger is useful to override sensible feelings of fear where one would rationally select the flight over fight response. Threats to offspring would probably be the instance where this is evolutionarily wise - get angry and punch that lion in the face, it might decide your bebe isn't worth it, or it turns to you and your troupe of kids get away to sew your genes further down the road. Upto a point, defending resources, and safeguarding the life points they give you is another probable."
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5s04ti | What is happening when you're falling asleep and suddenly feel like you're falling? | Repost | explainlikeimfive | {
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"It's called a hypnic jerk, and I only know of a theory, as it is poorly understood. So, you're lying down, feeling sleepy, you've had a rough day, your body tries to rush you into sleeping, instead of going through all sleep phases, it skips them and goes directly to REM sleep (rapid eye movement - this is when you usually start dreaming). When your brain does that, it didn't give your systems enough time to cool off, so instead of a gradual lowering of temperature(T) , heart beat(HR) and respiration rate(RR) , there's a sudden low T, HR, & RR, your brain then thinks yours systems are failing, and sends a signal, a twitch throughout your body to jump start them again. Again, this is one of the suggested theories as it's still a poorly understood phenomenon.",
"Many years ago I read a book, I think it was Dragons of Eden by Carl Sagan. In the book was the theory that it was a reaction based on our evolution from apes. We used to sleep in trees and if we were to slip while asleep our bodies would jerk us awake to prevent our fall. I could be wrong. I often am.",
"During Stage 1 NREM, the body is trying to transition from awake states to deep sleep. During that period, the body starts to block some sensations and slow down bodily processes. The reason you feel like you are falling is because your body has desensitized the sensation of pressure from the bed, so you panic and reach out to grab something, which brings you back awake to realize you were just in your bed.",
"Its called hypnagogic jerk. It is believed to be a minor epileptic event. Vsauce talks about it in his video about Dejavu. Worth watching. URL_0",
"scientists of reddit. I experience 'falling down' almost each time when i sleep after drinking. If you sponsor me drinking, i can volunteer in your research.",
"When you sleep all your muscles will relax. This causes the part of your brain that balances you to detect that you're falling as it thinks you're still standing up and if your muscles are relaxed then you would be falling so it does a massive jerk to stop you."
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5s0vni | Why do we use the base 10 system, and what are its benefits over other mathematical systems? | Repost | explainlikeimfive | {
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"no benefit, other than a convenient correlation with the number of fingers. there are better systems that work better with the base 2 of computers and which have more easily divisable fractions. Base 16 would probably be an ideal candidate for both things.",
"tl;dr: The decimal (base 10) system came to be bacause humans have 10 fingers and it made sense. There are other systems that are better, but we're stuck with this one because people don't like change. It was used by the ancient Egyptians and Greeks (Romans had a decimal number system, but they did it differently, and nowadays it's used in a more decorative context) and our modern 10 written numbers come from Arabic numbers. There are plenty tribes in the world that use different number systems, like base 12, 32 and 27. It's understandable that these don't make much sense to us, but it's important to note that mathematics doesn't care about which number system is used - the basic principles still apply. Curiously, the people who use base-27 actually point to their body to indicate numbers as we would by extending fingers. As for advantages of the decimal system, well, multiples of 2, 5 and 10 are easier to calculate in your head than, say, multiples of 7. That being said, many systems are superior in terms of factors, like aforementioned base-12 which can be divided nicely into twos, threes, fours and sixes, or the base-60 system which was used by the Babylonians, which has 12 factors! If you'd like to know more, [here's a nice video from Numberphile]( URL_0 ) - it's about base-12, but he talks about the decimal system too, as well as some interesting tidbits that I haven't mentioned, like the role the French Revolution had in most measuring units being decimal.",
"It's arbitrary. I think 12 would be great (so many divsors) or better, hexadecimal. I'm assuming that alien civilisations we encounter will use hex. They aren't stupid."
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5s142p | How can fishes survive tremendous pressure in sea/oceans with soft skin? | Repost | explainlikeimfive | {
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"It's not pressure that kills us, it's pressure differences. We can't survive down there because we're filled with air, and the pressure difference is so great that we'd be crushed. Fish, however, are filled with the same water that they're swimming in, so at best the pressure difference is minimal",
"Jammin-Johns answer is about the size of it. There are also microscopic differences in their biochemical structure but his answer is essentially right. Copying and pasting from my answer about \"Why are Sea Creatures to Big? Shouldn't Pressure make them small?\" Considered modifying it slightly to address the difference in your question but think it's just additional helpful information, so leaving it. The major issue has to do with differences in pressure. If you took a submarine and sent it to the ocean floor, it would get crushed. But if you cut a hole in the submarine and let it sink to the bottom, it would not, because the water inside would be at the same pressure outside and they would cancel eachother out. Humans have a problem because we have all sorts of air in our bodies. There is air in your lungs. In your digestive system. There is air in the sinuses of your skull. If you tried holding your breath and diving to the ocean floor, your rib cage and skull would crush long before you got there. There are other structural, metabolic and physiologic problems for humans to survive at depths but I don't think you were asking about those. Deep sea fish don't have so much air in their bodies, so, for example, they won't have swim bladders life surface fish do. They also have a very high water content of their cells. Water is notoriously incompressible. Putting more pressure on it will simply make it push back with the same pressure---its volume won't change, unlike a balloon filled with any gas. Deep sea creatures also have differences in terms of the structure of their organs and even the enzymes in their cells so that they can withstand higher pressures while maintaining their shape and function. You don't have this, so you would get squished even if air wasn't a big problem. What about whales? Whales are actually mammals and breathe air. They have lungs. But unlike you, their rib cage is very flexible and their lungs are specifically adapted to getting crushed when they dive. Pressure itself then is not a very limiting when it comes to size. In fact, the ocean environment (though not pressure) might even facilitate it. Because of buoyancy, they feel less stress from gravity enabling them to reach larger sizes. Large size also means they have less surface area to lose their body heat, so they can survive with slower metabolism, even in colder temperatures. There aren't so many things that can go into the deep sea, so they might be less likely to suffer from predation. I made that last one up, though. We don't really know why/how some creatures got to be so big, but pressure is not a limiting factor, at least not for the pressures you encounter in the deep sea."
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5s18el | Why is it that, on electric fans and other appliances, the order of the settings is OFF, HI, MED, LO? | Repost | explainlikeimfive | {
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"The motors need a lot of power to start from a stop position. Low power sometimes isn't enough power so the best choice is putting it on high as the first step.",
"Electrician in the works here It's bad practice to demand more electricity as the knobs turn. So it starts off at the highest to demand the electricity it needs to start and then lessens the load as you go on. High med low All fans are designed this way for safety"
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5s1a4y | how do cows gain so much weight eating only grass? | Repost | explainlikeimfive | {
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"In a day, a cow spends about 6.5 hours eating and drinking all of her food. The cow has four stomachs and undergoes a special digestive process to break down the tough and coarse food it eats. When the cow first eats, it chews the food just enough to swallow it. The unchewed food travels to the first two stomachs, the rumen and the reticulum, where it is stored until later. When the cow is full from this eating process, she rests. Later, the cow coughs up bits of the unchewed food called cud and chews it completely this time before swallowing it again. The cud then goes to the third and fourth stomachs, the omasum and abomasum, where it is fully digested. Some of this digested food enters the bloodstream and travels to a bag called the udder, where it is made into milk that will come out of her teats, while the rest goes towards the cow's nourishment."
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5s5r9e | Why do places like India and China have such a higher population than the rest of the world? | Repost | explainlikeimfive | {
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"Rice, rice, baby. Of all the crops available to the preindustrial world, rice produces the most calories per acre. At the same time, rice is more labor intensive than most crops. That means rice can both support more people per acre, and *requires* more people per acre to farm it. If you have a lot of land suitable for rice, you are going to have a great population density than your barley growing neighbors.",
"I'm from India, and I think the one of the major issues is the culture here. It was kind off the norm to have multiple kids. At that hasn't changed since. Lack of education is also one of the major reasons. The poorer sections of the society are ignorant of contraceptions or are indifferent. Even if their income is barely sufficient to sustain them, they continue to have sex and make children, because that's all that they know. And since almost 70% of the population of India are in the poorer side of the spectrum, the ramifications of this is large. Hence the population continues to blow up since a family will atleast have 2 or 3 children.",
"They have had a larger population for a very long time. Agriculture developed in their river valleys. Farming there developed a population density which persists. You can watch youtube videos on this. They still are very productive.",
"They don't. India and China have about the same square km size as Europe, however, Europe has a lot more mountainous regions and areas of low/little farming/habitation compared to those regions if you account for everything. Europe has a population of ~900 million with China and India having 1.3 and 1.2 Billion respectively. N. and S. America are just less populated because they have only experienced the agricultural revolution for about 500 years, give or take, on a large scale so their collective population is 1 Billion.",
"There may be an element of having lots of children so that you will be fed and cared for in your later years. It is also a cultural thing."
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5s6gtt | How/why does a circular camera lens create a rectangular picture? | Repost | explainlikeimfive | {
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"A circular lens projects a circular image, as you'd expect. That image, however, is projected onto a rectangular piece of film or a rectangular electronic sensor and the far edges of the image get cut off. This is good because the stuff at the edge tends to be blurry, dim, distorted and out of focus."
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5s80hp | why do people's accents seem to disappear when they sing? | Repost | explainlikeimfive | {
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"BA in linguistics here. I believe it is for a couple reasons. Reason number one being that you simply don't hear it as much. The differentiators in accents (particularly American accents) are in things like \"r\" sounds and vowel sounds, and when you hold these sounds out in a long way like you're singing, they sort of morph into a more universal pronunciation- if you're Scottish and roll your R sounds, or American and pronounce your R sounds very hard, or from London or Boston and ignore them completely (like \"cah\" instead of \"car\") it all sort of comes out the same when you hold it out to fit the cadence of a song. Second major reason has to do with the style of music. I think pop music and rock music are generally associated with a specific style, same way country music is. Look at Keith Urban, he is an Australian country singer and he still sounds like all the other county singers from the US. EDIT: spellings and stuff",
"One of the hallmarks of good singing is to produce big rich vowels. Making the resonant cavity of your mouth and throat as big and open as possible helps with this. Certain accents rely on having a more closed vowel sound, so singers (in English at least) often drift towards a more generic accent because the focus is on achieving a better tone. That being said, a common criticism of singers is that they sing with a fake accent. Americans that sound British, Brits that sound American, etc. Here on the west coast I've met a lot of singers who unintentionally put on a southern accent."
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5saoe2 | What makes a person left handed and why? How is it possible considering most people are right handed? | I hate to sound like an ass, but this is something i recently thought of when watching my brother draw. He's one of three or four lefties on our moms side and it's just something that caught my interest recently. What exactly makes a person left handed and why? Also I didn't want the title box to be super long, but I also wanted to know if there were any cultures or civilizations that are predominantly left handed. | Repost | explainlikeimfive | {
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"It's a genetic thing. [Some current theories]( URL_1 ) about handedness are that it takes several different genes in a particular alignment to make someone display a left hand dominance. This is why only about 10% of the population is left hand dominate. However, only a small percentage of that 10% is truly left hand dominate. Most are really [Cross Dominate]( URL_2 ) meaning that they use either hand to accomplish various tasks. Not that they can use either hand to accomplish the same task, but for various tasks, they have a dominate hand. Me for example, I write and hold eating utensils always with my left hand. But I hold drinking containers in my right hand. I'm also completely right handed in baseball and hockey, which is slightly weird because right handedness in hockey is the minority. > but I also wanted to know if there were any cultures or civilizations that are predominantly left handed. Probably not as being left handed is (still to this day) [frowned upon by some cultures]( URL_0 ) as being \"evil\".",
"[This]( URL_0 ) very informative video answers most of your questions. Hope it helps.",
"The fact that I'm left-handed has nothing at all to do with genetics. When I was a baby, my step-dad(who's a leftie) wanted me to also be a leftie. Whenever I had become old enough to start to reach for things, I would do so with my right hand. He would actually gently push my hand away over and over until I reached for whatever it was with my left hand. After so many times of him doing that, I must've learned that I would get what I wanted whenever I reached for things with my left hand. I love being left-handed, but I let my daughter choose for herself lol. She's a rightie :)"
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5sc6bo | The act of cutting a piece of paper or any other material. How does it work on the microscopic/atomic level? | When cutting any material how exactly does it separate on the tiniest of levels. What causes the separation? Why are some materials sharper than others? | Repost | explainlikeimfive | {
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"That's a lot of questions. Let's do them one by one. Edit: Yes. I know it's \"intermolecular\" not \"intramolecular\" I messed it up and you're right if you corrected me. **How does cutting something work?** Individual molecules are connected by bonds called ~~*intramolecular*~~ *intermolecular bonds*. These come in a wide variety of types, some more permanent than others. In the case of something like a metal (or any single element bonded to itself many times over) this means there shared electrons forming a permanent bond between any two atoms of the material. In the case of more complex molecules, this means there are weaker bonds holding the material together, either through polymerization, hydrogen bonding, dipole-dipole interactions, or London Forces (although the last three happen most often in liquids and are fairly temporary bonds comparatively). Paper is a polymer. You can see the general structure of the main component, cellulose, [here]( URL_1 ). The structures shown in brackets in the previous diagram repeat throughout the material, and connect to a structure of the same type at the ends that cross the brackets. If you expand the idea of what a polymer is to be anything with a repeating unit, then most things can fall into that category (metals are a repeat of the metal atom unit; glass is the repeat of the Silicon Oxide unit). You might notice on the cellulose that it only had connections at either end of the molecule (where it crossed the brackets); other materials can have many more connections between their repeating units (for example, glass can form more [3-dimensional structures]( URL_3 ) that loop back onto themselves, and iron forms a fairly regular [metallic structure]( URL_2 )). However, when the material is forming, different *grains* can form. In polymers like paper and plastics, this means that there are distinct layers and \"strings\" of polymer can form. In materials like metals or glass this means that several different areas will crystallize independently forming areas that are uniform but which run into areas that are different yet uniform with themselves (you can see the idea of \"grains\" [here]( URL_4 ) where each area that's shaded uniformly is uniform with itself, but not necessarily oriented the same as the areas directly next to it). **What causes the separation?** Either way, when you cut a material, you're exploiting the fact that there are imperfections in it. In the case of paper this means that you're cutting \"between strings\" of polymer and occasionally breaking a bond between two pieces of a single polymer string. Picture a big plate of spaghetti, if you push a knife down the middle of the plate, some of the noodles are going to move out of the way and some of them are going to get cut. That's what's going on when you cut paper, except imagine that your paper is about 400,000 noodles wide. Metals will tend to break along grain boundaries. It's possible to break it where you want instead of the grain boundary, but if you were to just chisel at a metal you'd tend to break along the grain boundaries. When you cut it with a more precise tool (such as a saw) you're relying on the fact that the connections holding any single atom that you're not directly influencing are stronger than the connections holding onto the atoms you are directly influencing. If you extend the Iron structure I linked to earlier further out and imagine you're cutting a swath out of the middle of it, it's easy to see how there are more connections holding the rest of the atoms together than are holding the atoms you're cutting away. **Why are some materials sharper than others?** The issue here isn't *sharpness* so much as *hardness*. Hardness isn't particularly well-defined scientifically, although we know it depends on bond strength and geometry. Bond Strength: This is the cumulative force holding together the material. It includes all the ~~intramolecular~~ intermolecular forces we discussed earlier. Iron is stronger than paper in part because iron bonds many more times to itself than paper bonds to itself. The energy it takes to remove a single iron atom is much larger than the energy it takes to remove a single cellulose repeating unit because the iron is better held in place. Bond strength also involves the chemistry of the molecules that are bonding. Geometry: Triangles are strong. That's why we use them in [bridges]( URL_0 ) so often. A force on any point distributes the force to the two adjacent sides. Thus, if a grain boundary ends in an edge similar to a triangle, it's going to be able to withstand much more force than a grain boundary that doesn't. It's very hard to get a paper polymer boundary that is triangle-shaped, but it's pretty easy to get an iron boundary that is. If material A has better bond strength and geometry than material B, then material A is harder and will cut through material B. How much harder A is than B determines how many times you can cut through B before your chunk of A is useless as a cutting tool. (When your A and B come together, A does cut B, but B does some damage to A as well, this is why knives dull with use).",
"Just for an easier example, if i have a bunch of magnets stuck together, each magnet being an atom, and i separate the magnets, the magnets dont get cut in half. The bond between the magnet simply is removed. That is essentially what happens with cutting a material. Edit: Wow guys, thanks for the upvotes! As for people questioning about why paper therefore doesn't bond back together, that is because many other particles get in between the paper pieces, preventing them from completely bonding back together. There are ways to bond materials back together, but those involve energy being used, and vary depending on material. Also, definitely check out the other results that explain much more in depth how this works, this is just a quick analogy for those who want a simple example.",
"I always wonder two things about cutting stuff... 1) I understand that when I cut things, I am simply breaking the bonds between the molecules. Why then, can't I hold those pieces back together and have them refuse at some point. Is the gap I created simply too far? 2) Why don't I ever accidentally, given the number of things I cut over my lifetime, ever cut an atom in half and blow up my town?",
"Nothing is happening at the molecular or atomic level. The paper is held together by intermolecular (electrostatic) forces. Pretty much every bulk piece of matter, other than metal or crystal, is held together this way. When you cut with the scissors, you are pulling apart weak bonds between molecules.",
"Top answer is not for 5yo and most of the stuff here is wrong. My attempt: Paper (and other materials) are made of small chains called molecules. They are bound very closely together with electrical forces. These forces can give up and those molecules separate from each other when you apply some force like with a scissors. You cannot simply \"glue\" the pieces together by touching sides because you need them to be incredibly close together so the electrical force is strong enough to hold them together again. You you could, it would work. And, when you rip paper apart, you're separating these molecules the same way. The only thing scissors do, is help you apply a stronger force along an exact line.",
"You know how you when you move you cut through air? Your molecular structure is more dense therefore you moving through other molecules separates them because they have less space inbetween. Everything works kinda like that. Bonds are forces that hold molecules together and there are several types of bonds. Gas molecules are kinda loosely floating about, rather light in weight, and aren't super attracted to each other so they're very easy to seperate and just kind of move aside. Liquid molecules are heavier and like to hug together but not enough to hold a shape so they have enough space in between and few enough bonds to still fairly easy to seperate so they move aside but want to connect. Solid molecules have lots of connections holding them all together like threads hold a shirt together. They're the heaviest molecules and they are able to push other molecules out of the way. Mass/weight is one of the main factors in being able to move things, the other being energy. If the molecules are extremely densely packed in a very tightly arranged formation with strong bonds holding them together, then they're going to be hard to separate. The tighter the bonds and structure and less space inbetween, the sharper it can be. Some materials are typically strongly bonded, very dense and heavy, and able to hold together in very thin strands of molecules. These are sharp. Other materials aren't as heavy or bonded as strongly, so they can't be as thinly strung or they'll just fall apart. There are many exceptions depending on the elements making up the molecules of course, and different atoms or forces shared between them can make them interact differently.",
"Question: if you do cut paper, why does not lead to the edges breaking the chain and lead to a new compound along the edges?",
"The simplest explanation I can come up with is that your cutting tool comes in between intermolecular forces holding the material intact. In your example, your scissors force an edge in between hydrogen bonds, causing the bonds move farther apart, which after some distance reduces the probability of their affecting each other to pretty much 0. Some materials are sharper than others because they expose an edge that isn't as wide. Of course, they're more brittle for basically the same reasons (fewer bonds, etc). Disclaimer: Not an expert.",
"Basically the pressure that you apply with scissors or knife is stronger than the bonds between molecules, so they just break apart. Imagine squeezing some lego bricks quite hard and how they would split off even though they are stuck together to begin with."
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5sf8bv | If our body temperature is 98F, why is room temperature 72F as opposed to 98 or any other temperature? | Repost | explainlikeimfive | {
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"In a 98F environment, the body would not be able to get rid of excess heat (generated by metabolism) by passive conduction, and sweating becomes the only efficient means of discharging heat. In addition, in most climates, such a temperature would be expensive to maintain as opposed to the 70s",
"Disclaimer: values in Celsius because I can't Fahrenheit. The human body produces heat through its activities. The amount of heat generated will vary depending on the individual metabolism and whether we are standing still, running, sleeping etc, but generally speaking the heat generated is more or less constant. Our bodies however have developed mechanisms that allows it to modulate the heat dissipation, which in turn makes us able to live in contact with a wide array of environmental conditions. We can survive relatively well in cold temperatures (around 0°C) by producing more heat/letting less heat escape (through our body hair for example); on the other hand, sweating allows easier heat dissipation when confronted with warm environments (32°C +). That being said, room temperature (25°C) is just a arbitrary point chosen by us, warm-bodied humans, as a temperature in which the amount heat generated by our bodies is more or less equal to the heat dissipated to the enviroment (due to it being slightly colder than our bodies), thus generally being regarded as pleasant."
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5sfhtv | How does converting cars and such to electric help the environment? | Repost | explainlikeimfive | {
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"Non-electric cars run on some form of fossil fuel that is extremely polluting. When you use electricity instead you have more options for producing the energy fueling the cars. So it becomes possible to use less polluting energy sources like solar power, wind power or even nuclear energy. Edited to be more clear"
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5sg6ry | Why is the measurement of time (seconds, minutes, hours) based around the number 60? Why not a more common base, like 10 or 100? | Repost | explainlikeimfive | {
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"60 is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30. Lots of options for splitting time into neat segments. You can divide 60 into halves, thirds, quarters, fifths, sixths, tenths, twelfths, fifteenths, twentieths, and thirtieths. 10 is only divisible by 2 and 5. So you can only divide it neatly into halves and fifths. It's just not as flexible. Edit: I'm a political junkie, so I comment on a lot of threads featuring hot-button issues. But according to my inbox, this is the most incendiary comment I've ever made.",
"Everyone answered this well, but note that if you count finger bones (3 on each of 4 fingers) rather than fingertips, you could be counting in base 12 and counting/tracking up to 60 is simple 12 bones and 5 fingertips (which is what we believe the Sumerians did).",
"URL_0 \"There are two entirely different kinds of \"minute\" or \"second\", and you have to be careful not to confuse them. In each case, they are 1/60 of some larger unit. When we measure time, we divide each HOUR into 60 equal parts called \"minutes\", and each minute into 60 equal \"seconds\". We also do the same thing when we measure angles, so that each DEGREE is divided into 60 minutes, and each minute OF ANGLE is divided into 60 seconds. The units are different; an hour is not the same as a degree in any sense, and their relationship has nothing to do with the angle corresponding to a minute on a clock, or in the earth's rotation. Here's what happened. The ancient Babylonians liked the number 60, and in fact based their number system on it almost the way we base ours on 10. So any unit would be divided naturally into 60 equal parts. That worked well for various reasons, so early astronomers used that scheme to measure angles, dividing a circle into 360 parts (6 times 60), and then dividing each of those parts into 60 minutes, and then into 60 seconds. The word \"minute\" just meant \"little part\", and \"second\" meant \"second division into little parts\"! At some point people started wanting to divide time into smaller parts too; in ancient times it was hard enough to measure hours, but once mechanical clocks were invented it became possible to divide hours up. How many units should there be in each hour? They might have used 12, as they had long before divided the day and the night each into 12 parts; but someone felt that 60 parts would be nice (probably an astronomer!). So they needed a name for 1/60 of an hour, and since \"minute\" already meant \"1/60 of something\", they called it a minute. They probably never considered the confusion it would cause when someone looked at a clock and asked how far the hand had moved. If I say it moved 30 minutes, do I mean 30/60 of an hour on the dial, or 30/60 of a degree of angle? That's unfortunate; but if you remember that the size of a degree has nothing to do with the length of an hour, and that the two kinds of minutes are just 1/60 of an hour or a degree respectively, then you can see that they just aren't related. If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum URL_1 Associat\"",
"The answers here are interesting, but they just provide arguments why 60 is a good choice, no historical reason as for why 60 was chosen. The previous edition of this question really nailed it. I could go ahead and copy some comments verbatim but it's so young that users there can still receive karma: URL_0",
"Lots of people mention the Sumerians, but they definitely didn't have hours, minutes, and seconds to measure time. Rather, the answer lies with the Greeks. In Egypt. Because Egypt was Greek at one point. Specifically, the famous 4th century CE astronomer Ptolemy, whose wildly incorrect views of the universe were the basis of modern science until basically Galileo. In his time, we didn't have decimals. I mean, we didn't even have *digits* yet; those came from India a few centuries later. So we used fractions, and thanks in part to the astronomical traditions inherited from the Babylonians, the common method of approximating numbers was with fractions in base 60. You had some whole number of a quantity, then some number of minute divisions, and some number of *second* divisions, *third* divisions, etc., each of them 1/60 of the previous one. So degrees were divided into minutes (1/60th of a degree), seconds (1/60th of a minute), thirds (1/60th of a second), and so forth, and that's how Ptolemy did his astronomical calculations in the Almagest. Since his book was so influential, it's what people continued to use, in Arabia and then Europe, for centuries until Ptolemy's geocentric view was replaced by actual orbital mechanics around the Sun. Meanwhile, a system of describing time needed to be precise as well for these calculations. They didn't have *clocks*. They had divided the day and the night into 12 hours each, and these were standardized as being all the same length so there'd be 24 equal hours in a day (this was an Egyptian thing too), but there were no clocks so it's not like you could see what time it was. But the numbers were used in the calculations, so they were divided the same way degrees were, into minutes, seconds, thirds, etc. Note that even if you assume geocentricity, the Sun still goes around the Earth on a 24-hour cycle, so you could draw that circle of the Sun going around the Earth and use it as a reference point for the other celestial events being modeled. Well, eventually we got clocks, and since we were already using minutes and seconds as divisions of the hour, those became standard. Thirds were too small to use, so there was no point. That's why today we don't bother with thirds, just minutes and seconds, and we use decimals (because they've been invented) to get smaller bits of time.",
"Some good answers already, just wanted to add that they could count to 60 by using the five fingers of one hand to point to the twelve knuckles of the other hand.",
"/u/ezbot0 is the only correct person here so far. The ancient Sumerians used base 60 for all numerical values and invented the concept of the second that we use today. All of this stuff about divisibility is total nonsense",
"Ten and 100 are common bases now, but we've been measuring time since before base ten was fashionable.",
"first of all, we use 360 degrees to make circles and measure the angles of polygons. Next, we use 32 degrees as freezing, add 180 deg. F., and we get the boiling point of water, 212. It's definitely NOT decimal, only. Next, we use 24 hours to a day, 60 minutes to the hour, 60 seconds to the minute, and so forth. Same with degrees latitude and longitude, 1 degree equals 60 minutes, 1' equals 60\", and so forth. also we use 12 to make a dozen as well. It's the same principle, as 24 hours in a day. The reason is Babylonia's hexadecimal system which was base 60, essentially. IN ancient times, they did not have our fractions system. They used integral fractions, which the Egyptians invented and were the basis of fractional maths until about the 1400's AD or so. Each fraction was 1/n, so that everything fractional was expressed as a series of 1/n. 1/2 was easy, but could be expressed using 1/6 plus 1/3. It was a very efficient method of dealing with the details of measurements, the fractions. It was highly efficient as most methods from Khemet. Pen and ink we still use the last 5K years, right? Efficiency. For the Egyptians, PI was 4(8/9 squared). It's about 3.16, and it's the easiest way of expressing PI, as well. using their integral fraction methods. Note how many ways we can cross out 2 3's, 4's, 6 & 8, and so forth. It's a very quick calculation method and finding. But the key was as stated briefly below. 12 is divisible by 1, 2, 3, 4, 6, and 12. Which made divvying up objects a lot easier. Bakers use the dozen even today. This made partial amounts LOTS easier to manipulate. 24 hours in a day?, perfect number, 1, 2, 3, 4, 6, 8, 12, 24. Again, easy to divvy up the days, is not? The numbers of companies in an Egyptian military division column? You guessed it. 12. And multiply by 5, and get 60. So, where using fractions was key, as in measuring, it provided a HUGEly simple, time saving method to do the calculations, right? & highly accurate, too. It WAS Efficient!! Nothing better for 4000 years!!! Least energy all the way. & that's why it was used and succeeded and still does. Least Energy Rules. and THAT's why we still use it. Least Energy, 2nd law of thermodynamics. Processes strongly tend toward least energy paths. Even planets in orbits. Even suns orbiting the galaxy. Even the paths of every single, observable & known, photon. Least energy. Universally true, in the entire universe. Facts? Fusion is seen throughout the observable universe, and the combining of 4 protons to make a very stable He4 atom is least energy favored. 14 gigalight years into the future and up to the present and all spaces in between. & 14 GIGayears into the past, up to the present and ALL times in between. Enormous stability. Also least energy. So, it's NOT just ease of calculating, but thermodynamics and AND physics, too. Least energy Rules. This Is how it works: URL_2 Save energy and the system massively grows, in the long term, as above. This is how it works in the brain/mind: URL_1 And that's the \"Depths within Depths\" understanding underlying the 60's, 24, and 12 counts, too. Physics, universal. And our brain works using least energy, as Dr. Karl Friston (Univ. Coll. London, Dept. Neuroimaging), has repeatedly shown, too, in his work on brain and neuroscience. Dr. M. O'Keefe there got a Nobel Prize in Med./Physiology in 2014, to give some idea of the quality of work there. To whit: a deep and rigorous sets of evidences, URL_0 But you asked..........",
"The real question here is why don't we use a base 12 number system? :( then questions like this wouldn't exist",
"What's always bothered me is, why make a mile 5280 feet? Why not just a nice crisp, easily mathed number like 5000?",
"A little more in-depth than a ELI-5 typical answer because understanding the historical context is key to the reason behind the 'standards' used to measure time. URL_0 TLDR: The ability to measure time increased in precision as advances in technology progressed. Metric system debuted about the time it was possible to measure 'seconds' with reliable precision. First was day/night. It was either dark or it was light. Tracking the movement of the sun/stars made it possible to be somewhat more 'precise' in knowing when it was during day/night in general. Time-keeping devices made it easier to 'sub-divide' the day into smaller increments. Those increments used the 'common' measurements of the day, i.e. base 12, then base 10, and continuing to today's ability to measure to the zeptosecond. A zeptosecond is one trillionth of a billionth of a second. It was used to measure an electron escaping its atom for the first time in 2016.",
"I always thought it was based on the average heart beat, about 60 bpm. Could still be partly true, but there's some great other answers here!",
"60 hours? I don't think so. 12 hours, as in 12 months (lunar cycles). I would think 12 would be the base, and then come the other (both greater and smaller).",
"The French tried to do this after the revolution in 1789. They restructured much of their daily lives, like renaming the months of the year and restarting the calendar. Some things lasted longer than others, but keeping time with 100 seconds per minute/100 minutes per hour/10 hours per day was not one of them.",
"I read somewhere once (don't remember the source) that it has to do with our Gregorian calendar. Sort of irrelevant , but that's why Stonehenge has around 56? pits dug into the middle area. Had to do with their different form of keeping track of time. But that doesn't really explain why they still go by normal (as listed above) hours , time, minutes, etc.",
"URL_0 Take a look at the first 4:30min of the video. He talk about highly divisible numbers. Meaning which numbers have a lot of divisible numbers. That's why we use 60. 10 is really not a good numbers for that. The only reason it seem more natural is because we count in base 10 and we count in base 10 because we have 10 fingers. That's also why the imperial system is in base 12, 24 hours in a day, or that we use 360 degrees in a circle.",
"Because it's historically how they did it. When humans tried to count time a long time ago, they separated the circle the sun dial went around in 360 degrees, (6x60), and then each degree in 60 arc minutes, and each arc minute in 60 arc seconds. 60 has lots of dividers (2x2x3x5) so its a convenient number. This system dates back to ancient romans and Greeks, if not before, if I'm not mistaken. Then, in the French revolution, people did try to change it to decimal, when they invented the metric system. They made decimal clocks with hours 100 minutes long, and minutes 100 seconds long, decimal calendars with weeks of 10 days, etc. But they never managed to implement it fully before they got replaced with another government, and the old way to count time stuck even though the metric system stayed. Honestly I think they shouldn't have used base 10: they should've used base 12, just like inches and feet use, but make every unit of measurement use 12. It has more dividers than 10 (2x2x3) which makes for easier fractions and multiplication, and people were already used to it thanks to the feet and inches. Oh well."
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"http://rsif.royalsocietypublishing.org/content/10/86/20130475",
"https://jochesh00.wordpress.com/2015/06/03/a-mothers-wisdom/",
"https://jochesh00.wordpress.com/2015/09/01/evolution-growth-development-a-deeper-understanding/"
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5sjhc0 | Why are humans the only species that needs to cook (most kinds of) meat to eat it? | Repost | explainlikeimfive | {
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"Short answer: Because we figured out how. Cooking meat allows us to extract about 15% more calories from it because of the denatured proteins. Similar for being able to mechanically digest it. So ground beef that's been cooked to medium has about 25% more effective calories than the same weight of uncooked roast. That lets humans be the efficient ape. Compared to Chimps (our closest relatives), we've got about the same amount of gut and about half as much jaw for twice the ape. Cooking food kicks ass. And this is even skipping over the huge gains that we get from our ability to take \"questionable\" (read, not really questionable, but almost certainly full of Trichinosis) meat and make it fully safe by sitting it over a smoky fire for a few hours. Really, it may not be necessary to cook your meat, but it's so much better that it's no wonder the thermivore ape kicked the ever loving shit out of the omnivore apes when it came to competition for environment suitable for living/fucking/fighting.",
"We don't need to cook meat. You can eat it raw if you want so long as it's fresh. Humans were just the only ones to discover cooking meat prolongs its life and makes it easier to digest, which in turn allows us to absorb nutrients better. You can survive just fine on raw meat. You can't do it on week old raw meat though and our food system is designed so that the majority of meat people have access to or will use is old enough for it to be unsafe or at the very least risky to eat raw (because it's assumed you'll cook it).",
"Humans don't need to cook meat. Freshly butchered meat is reasonably safe raw, unless it has parasites. And that is the same risk other animals take when they eat raw meat. Humans cook meat because: * it kills parasites * it preserves the meat * it makes more calories available from it * because we can",
"We don't need to cook meat to eat it. This should be obvious what with all the sushi restaurants. Cocking food makes the nutrients more available for our digestion and clears out many parasites so it became the norm. It is not required though.",
"Cooking food has allowed us humans to take on more calories in a shorter amount of time. Cooked food, e.g vegetables, are easier to consume, digest and absorbed into the body. Hence, unlike cows and other animals that has to spend the entire day grazing on the fields to meet their daily calorie intake, humans just need a short period of time (breakfast, lunch and dinner) to have sufficient energy. On top of that, cooked food reduces the odds of getting food poisoning.",
"We don't when we have a fresh kill. The issue is that we do not eat meat within minutes of killing the animal, we kill it days or even weeks before we consume them and ship them about the world and buy them in grocery stores. That allows bacteria to grow and that bacterial growth is what will make us ill.",
"Because we don't have the flora needed to neutralize the excess bacteria/parasites in raw meat.",
"Besides some of the replies here, it also saved us a bunch of time in the day, allowing us to pursue other interests. Most other animals spend much of their waking hours chewing and eating. Watch Cooked on Netflix. It deals with this very concept",
"Reading all of these correct answers, something else occurs to me: Because it tastes better? Sure you get more calories from cooked food, but in the end, I think the driving factor for the first couple of thousand years was that a cooked piece of food usually tastes a lot better, and who doesn't choose that?",
"Because we are actually an alien species and Earth is not our natural habitat. Think about it. Why do we need cooked food or clothes and shelter when others species just sleep outside. Why do we need all this infrastructure and overhead just to exist on this planet. We are the most foreign thing compared the rest of the planet and its inhabitants."
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5sl0yq | bose-einstein condensate | What is it? How is it made? What practical applications does it have? What's it's history? | Repost | explainlikeimfive | {
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"A Bose-Einstein condensate is a very special phase of matter which certain elements and compounds are thought to be able to enter. One which is known to be able to enter it is helium-4, which we call superfluid (slightly different but closely related) when it does so. The origin comes from statistical and quantum mechanics and can be a little complicated but I'll try to give a breakdown. **Fermions vs. bosons:** one way to categorise particles is by their spin. Spin is an intrinsic property of particles (like charge or mass), and goes in units of 1/2. Fermions are particles which have half-spin mutliples (e.g. 1/2 or 3/2), whilst bosons are particles which have integer spin multiples (e.g. 0 or 1). Spin belongs to elementary particles like electrons with spin 1/2, or photons with spin 1, but also to composite particles like atoms. As an example, helium 4 is composed of four protons, four neutrons and four electrons, each with spin 1/2. But these spins pair up and align against each other (e.g. two electrons pair up, one has spin +1/2 and one has spin -1/2, so the pair has a total spin of zero). This means that even though helium-4 is made of fermions, it is itself a boson. **Quantum states:** quantum mechanics tells us that particles live in something called a state. The state has a defined energy (among other qualities). The lowest energy state is called the *ground state*. **Statistical distributions:** fermions and bosons follow two different statistical distributions (Fermi-Dirac and Bose-Einstein respectively). These tell us how ensembles of these particles behave. The long and short of it is that fermions can't share the same state, whilst bosons can. With these things in mind, lets consider an ensemble of bosons (e.g. helium-4). What happens when it cool it right down towards absolute zero? Well at some point (for helium-2, about 2.5 kelvin), all the particles drop into the lowest energy state, the ground state, from all the states above. We now have a state of matter in its lowest possible energy configuration. That's why Bose-Einstein condensates from. It's tough to explain without a bit of quantum mechanics. You make it, as said, by cooling the right kinds of particles down to the transition temperature for it to happen. In terms of history, Bose-Einstein condensates were predicted in 1924-25, then superfluid helium-4 was experimentally made about 12 years later. It finds applications as a quantum solvent, letting scientists study particles as though were in a gas; in high-precision gyroscopes, and in cooling devices when things have to be cooled to extremely low temperatures. Superfluid helium-4 was also used to slow down light, effectively trapping it, in an experiment in 1999."
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5sl6zu | Is Aspartame hazardous to your health? I use to believe it wasn't but has that scientific consensus changed? | Repost | explainlikeimfive | {
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"Aspartame is probably the most heavily tested and verified safe food additive that exists. At various times conspiracy theorists and hypochondriacs have accused it of being dangerous but they have always been at odds with science."
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5slhqv | In these sanctuary cities, Why are the Mayor and city council not being charged with aiding and abetting a criminal, and harboring a fugitive? | Repost | explainlikeimfive | {
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"They aren't actually breaking any laws or (legally speaking) aiding and abetting anyone. They're just refusing to do the Federal Government's job for them. It's not up to individual local governments to enforce federal law and they can't be forced to if they don't want to. If they were actively preventing federal officials from entering their cities that would be a different story, but that's not what they are doing.",
"A few decades ago, the federal government passed a gun control law that mandated that local sheriffs enforce federal gun licensing. The sheriffs refused, and took the case to the Supreme Court. The Court decided that the federal government didn't have the right to force states to use state resources to enforce federal laws, and invalidated that part of the law. Same thing applies here. The feds can't make it a crime for state police forces not to enforce federal law, at least not without some legal maneuvering that has yet to be tried. Also, I would add, I'm most cases this wouldn't be aiding and abetting or harboring a fugitive. Those are usually very specific charges that require more than not giving someone's immigration status to a federal agency."
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5smioq | How does the physical infrastructure of the internet actually work on a local and international level to connect everyone? | Repost | explainlikeimfive | {
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"The coaxial (cable)/twisted pair (ADSL) leaves your house and goes to a building that's nearby (a mileish) called a Central Office (CO). These cables are buried underground, usually down the street in front of your house or alleyway, or carried on poles if you get your telephone or cable that way. In the CO all of the copper lines from all of the houses in the area come together and are plugged into some devices there. The step from the local office to your house is called the \"last mile\". These devices detect amplitude (how big) and/or frequency (how often) changes in the voltage on the line and convert it into digital data (ones and zeros). This process is called demodulation. From here your data is lumped together with all the other data coming into the CO and sent over a fibre optic line, usually buried under the street or hung on a pole, to a big data center where your ISP's routers are. Fibre optics can go very far, so there are usually only a few of these big data centers in a city. These data centers are physically connected to one another with buried fibre optic cables, and then one or more of the data centers in each city are directly connected to one or more of the data centers in neighbouring cities. So the fibre goes from your neighbourhood CO a mile or so away to a much bigger building somewhere in the city, which then has connections to other data centers in the city and in neighbouring cities. Electrical signals are converted into light using a transceiver. The light then bounces down the fibre optic line to the transceiver on the other end, where it's turned back into electrical signals. In the data center your ISP's routers look at the data. Routers are responsible for moving data between different networks. They look at the destination IP address and figure out which IP network the data is destined for. Then they look at these big tables (500,000+ entries) that match each IP network to an ISP based on the ISP's autonomous system number (ASN), which is how the internet sees an ISP. You see \"Verizon\", the internet sees ASN 701. Having it's own ASN, and having a copy of the table listing all of the IP network to ASN assignments is basically what makes an ISP an ISP (well, that and connecting to other ISPs). Once the router knows which ASN the data has to go to, it looks for the edge router that is closest to the destination ASN, and then sends the data bouncing through its data centers, city by city, until it gets to that edge router. More about edge routers later. ISPs connect to one another by burying fibre optic cable from one of their own data centers to an internet exchange (IX), which is a place where a bunch of other ISPs have agreed to drag fibre lines to as well. For obvious reasons, ISPs will also just designate one of their own data centers a Point of Presence (POP) and \"allow\" other ISPs to bring fibre cables there and rent rack space in the building. ISPs themselves, or companies that specialize in this, will also sometimes bury cables directly between IXs and POPs that are far apart (e.g. on different continents). These connections can be very, very long and very, very expensive. They will bury it over land or sea, farmland, forest, mountain, coral reef or deep ocean. These lines are usually one big continuous unbroken link, minus a few repeaters/amplifiers/regenerators which keep the signal strength up, and go for thousands of miles. In an IX or POP, which is basically a warehouse, each ISP is given space on computer racks in the building. So your ISP has brought their fibre optic cable hundreds of miles from their data center to the IX or POP and routed it through the building to their racks. They then place their edge router in the rack and hook up their backhaul fibre cable to it. A physical fibre optic or copper cable is then ran from your own ISPs edge router, through the building, to the other ISPs edge router, which is connected to its own long distance fibre cable back to that ISP's data centers. ~~And that's how babies are made~~ Edge routers tell whatever ISP they are connected to which IP networks your ISP owns, and then, importantly, they also usually say which additional ISPs your ISP is connected to as well. ISPs will then sign agreements between themselves regarding how much, if anything, they will charge one another for data going between them, and whether or not they are allowed to send data only to that particular ISP, or if they are allowed to also send to ISPs that THAT ISP is connect to as well. This is called peering. It should go without saying, this is a huge simplification and stereotypification of something that can go a billion different ways. One usual variation is that there are companies that specialize in burying fibre optic lines between IXs and POPs, so that if ISP A wants to talk directly to ISP B, but is far away from ISP B, they can pay to use part of one of these companies fibre lines to get from an IX where ISP A is to an IX where ISP B is, rather than paying to construct their own long distance cable. *Edit* I realize this is more of a ELI 1st year college student... but there you go... *Second Edit* Obligatory thank you for the gold, kind stranger. May your internet be forever fast and reliable... *Third Edit(s)* Good points from some great folks that newer implementations of DSL move the aggregation point (where your DSL line ends and your data is sent onwards over fibre optics) much closer to you and it is likely just a cabinet down the block. This makes things faster for you. Also remembered what a CMTS was, corrected a few typos, and added a few terms.",
"Cables , there are literally cables circling the world under the sea. Smaller cables go to your house but ultimately connects with them. Satellites also exist on the Internet network of cables connected by sat dishes plugged in This is the simplest I could think to explain it to give a mental picture of it. Think there is no difference in small to large scale connections just think of it bigger",
"Of course there is more to it than this, but it gives you an idea of routing and priority. When visualizing the routing protocols I try to turn it from data packages into real packages (mail), imagine this scenario. There is a post office at each local, city, region, country. **Case 1** The example address of 3805 S Keystone Ave, Indianapolis, IN 46227 USA going to 1400 E Hanna Ave, Indianapolis, IN 46227 USA. When the letter is given to the clerk at \"Indianapolis, IN 46227\". They recognize that the destination is already from their routing point and just puts the letter back in the out box. The local mailman knows about \"1400 E Hanna Ave\" and proceeds to drive to the destination. **Case 2** The example address of 3805 S Keystone Ave, Indianapolis, IN 46227 USA going to 87-135 Brompton Rd, Knightsbridge, London SW1X 7XL, UK The clerk at \"Indianapolis, IN 46227\" sees this is for a different City and sends it up to state level. The clerk at \"Indiana\" sees this is for a different country and sends it up to the National level. The clerk at \"USA\" Sees this is for \"UK\" and then sends it to their routing hub. From there \"England\" down to \"London\", then finally to \"Knightsbridge\" Which hands it to the mailman that goes to 87-135 Brompton Rd for delivery. **Edit:** Adding a data visualization of the [Internet backbone]( URL_0 #/media/File:Internet_map_1024.jpg) from the [wikipedia]( URL_0 )",
"Network engineer here in the Portland, OR area. Internationally, you have few grade 1 providers such as L3 networks, XO communications, ATT, Verizon, etc. Pretty much old school telco providers that have the scratch $ to invest in high speed cabling. Most of this cabling is fiber optic bundles of a few strands to several thousand strands. Each pair of strands can currently carry up to (theoretical max at this time) 255Tbit per second, but most pairs are currently carrying 100Gbit and are aggregated together into a single connection for trans continental or trans oceanic crossings. They essentially hop along the shortest path of each respective network from router or Layer 3 switch (which is also a type of router) to the next and often utilize border gateway protocol (BGP) and Open Shortest Path First (OSPF) which is are algorithms that find the shortest paths on networks. BGP is self healing and automatically detects accidental fiber cuts or outages due to hardware failure. Think of these as \"upstream\" networks as most international traffic terminates at these types of carriers. Going down to more the local level, there are usually major network hubs in the world. Examples of this are: Seattle, Portland, San Francisco, Los Angeles, New York, London, (Fortaleza, Brazil), (Seixal, Portugal), (Mumbai, India), Hong Kong, Tokyo, (Pusan, S. Korea) etc. There are more worldwide, but I only usually deal with US based carriers as my work only serves US needs since it has to do with a national healthcare network. These terminate all of these high speed connections to lower level providers like your Comcast, Time Warner, ATT, British Telecom, Telekom, etc. distribute their private and public networks which then resell the upstream bandwidth to individual customers. Here in Portland specifically, there are roughly 2 single buildings that if, were destroyed would probably knock the whole state of OR offline because almost everything downstream flows through them and are the terminus for most of the networks from CA and WA and far east. This reselling of bandwith is sometimes done on an oversubscribed method. They sell more than they have. This is where you get into instances of \"slow\" internet locally and used to happen a lot more than it does now, but is still an issue in a lot of places. The carrier simply does not purchase enough upstream bandwidth to carry all of their customer's data. This is where caching nodes come in, such as Akamai, Amazon cloud, Microsoft Cloud, Netflix etc. These are geographically disbursed data centers that basically have local copies of all content on the internet that people are trying to access. For instance, someone in San Jose, CA wants to Netflix \"stranger things\" they get it straight from Netflix's data-center near San Jose. But then Joe in the UK wants to watch it, that data is sent from San Jose to somewhere in London to a cache node at super high speed and then stored there. Joe doesn't notice this but now that it's stored locally in London's cache node, everyone else on that node has access to it without having to make additional pulls from the original and thus slowing down the internet as a whole. Some 3rd world countries that have extreme restrictions on what their people can access, such as North Korea, use deep packet inspection and firewalls to say what people can access. This also results in them usually only having one single point of internet coming into the country which can be knocked out easily if someone gets out with a backhoe and digs up the fiber cable. EDIT: forgot OSPF and little odd and end items",
"This is complicated. There are lots of different things going on at the same time. The analogy with letters by /u/Atzen doesn't really match how it works, unfortunately. It's a little more like phone numbers and a phone book. But I'm going to strip out the analogies. **DNS:** Let's start with typing in something like URL_0 into your browser. A certain part of that, URL_1 , is the *domain name* which tells you which computer has what you're looking for. But the domain name is not enough, it's like knowing a person's name. What you really want is something like a phone number or address. The post office doesn't know how to deliver a letter to \"Joe\" and the phone company doesn't know how to route a call to \"Joe\" either. So the first step is to look URL_1 up in a directory and you get an IP address, like 192.168.200.5. Now you can send packets of data to that address. **Routing:** So your computer sends a packet to 192.168.200.5. Let's say your computer has an address of 10.1.2.3. First, it checks if the address is on your network. Maybe your network has addresses like 10.X.Y.Z, but 192.168.200.5 doesn't look like that, so your computer needs to send the packet to a router that will send it to the right network. Maybe the router has address 10.0.0.1. So your computer sends a packet to 10.0.0.1, with the instructions \"please send this to 192.168.200.5 for me\". Your router is dumb, and only knows that it should send everything over your internet connection to your ISP. At your ISP, there are some smarter routers. One of them will get the packet, and look at it, and say, \"I know where the 192.168 network is, I'll send it that way.\" Your ISP isn't connected directly to that network, so it takes a few hops and visits a couple more routers along the way. Later on, a router might say, \"192.168, that's me! Actually, 192.168.200 is its own network, but I know where that is\". Eventually, you'll get to the 192.168.200 network, and the router will just send your packet straight to its destination. Each router only has a little bit of information. (There are other ways to route packets… sometimes you take a smart router, have it write some instructions on a packet, and then send the packet to a bunch of dumb routers which just read the instructions written on the packet.) If you want to see exactly which routers you use, try running a terminal command like `traceroute URL_1 ` **Connections:** Routers are connected to each other mostly through fiber optic cables buried in the ground. This is super expensive but very fast and reliable. Some connections go across the country, or across the world, and some connections just go to other parts of the city. They mostly work the same way: you take a router, give it a little bit of information like \"192.168 is that way\", \"10.0 is over there\", \"172.16 is behind you\". However, it gets a fair bit more complicated when you realize that for every router and piece of fiber optic cable, somebody *owns* that piece of equipment, and wants to get paid for letting you use it. The way it works is each company builds out their own networks, and then the networks get connected to each other at special places. So maybe I have my own network, CoolNet, and I run fiber optic cables from Seattle to Portland, San Francisco, Los Angeles, and San Diego. Then another company, AwesomeCom, runs a cable from San Francisco to Reno to Salt Lake City. If you're Kirkland, WA and make a video call (Facetime / skype whatever) to your uncle in Provo, UT, your packets goes through a few networks. * First, it goes through your home WiFi network. * Then it goes to your ISP's network. Your ISP has a bunch of cables going from their buildings to their customer's houses, and a cable which goes to Seattle (plus a few backup cables). * Once in Seattle, it goes to what's called a \"colocation facility\". It's a building, or maybe a couple floors of an office building, where everybody connects their networks together. Your ISP has a cable that goes here, and they have a router inside the building. They rent space from the colocation owner. The colocation facility has its own little network inside. * Since CoolNet also has cables going to the Seattle colo facility, your packet now goes through CoolNet. I can't connect you to Provo, but I can send your packet to another colocation facility, this one in San Francisco, CA. * Now AwesomeCom carries it to a colo facility in Salt Lake City, UT. (AwesomeCom and CoolNet are both huge networks, so we have a \"peering\" agreement where we can just send packets through each other's networks for free, since it's good for both of us.) * And your uncle's ISP carries it to Provo, UT. * And your uncle's router will send it to your uncle's iPad or whatever. If you are running a business and want a website that's easy to access, a great way to do that is put your computers inside a colocation facility. That way, your servers will have like 20 internet connections, instead of just one or two, and it will be easy to access.",
"To get internet across the ocean there's these giant cables underwater that transfers the information physically. It's impossible to do that wirelessly without satellites and satellites are way more extensive than the cables.",
"There is no difference between local and international. The internet knows no borders like we humans do. However different devices and protocols are used for different scales. BGP is what drives the internet on really large scales, it decides where certain IP addresses are (blocks to be more precise). Different peers (entities) decide at forehand where stuff should be. These really large routers keep track of these locations. The big traffic is mostly moved over fiber and satellites owned by private corporations and some gov. here and there. The cross Atlantic fiber optic cable is a good example of this. Then it arrives at the ISP's (and big corporations). They have their own internal network which uses different technology to move the traffic. These are the people that provide the connection for the \"home user\" Be it mobile network or broadband connections etc. The ISP makes sure you have a connection with them and they make sure they have a connection with other ISP's (this is a simplification) I could expand on this for a long time but I think this will cover the basic idea.",
"There are 2 kinds of 'addresses' (that is, something that uniquely identifies a device). At a local and directly connected level (or level 2), you have the MAC address. Every device in the world has a different MAC. This helps 'packets' (of info / data) be sent at a local level. Next, you have your public IP address. If your MAC is your house number, your public IP is your street name and post code. This is referred to as 'level 3' routing Finally, you have your private IP. This would be like an individual person. Like in real life, people might have the first name and last name, but generally never in the same house. A device's private IP (like 192.168.x.x) is not unique, but it's unique to your house, and identifies your device. Now, imagine you live in America and want to Skype some one in Australia. Your PC can't find the IP address it's looking to send a packet to locally, so it uses its mac address to send it to the router. The router, too, can't find it directly connected to itself, so it uses a DNS server (which is like a road map) to see where to send it. It will then send the packet to the next-best router, and this will repeat. While the destination MAC address changes each time (as it is used to route locally), the destination IP doesn't. (E.g, while driving from place A to B, the road you drive on changes, you can only go on roads connected to yours, but your destination is the same). Finally, the packet will arrive at the right router (your house's private IP ), and will send it to the device it was destined for. For all of this to happen, there needs to be a connection (be it copper, fibreglass or wireless / satalite) from end to end, and way that this info is sent depends on each kind of medium used. If you were to travel by sea, you'd use a boat. If you were to travel by land, a car would do. Similarly, a router will determine how to send the packet, depending on the medium of the next router (or next 'hop').",
"At the physical layer (aka layer 1), transoceanic fiber optic cables owned and operated by service providers (some private, some government). This video, although a little old, does a great job of explaining layers 2-4 at a level that most people understand. URL_0",
"As far as the global internet infrastructure is, A device can connect to the internet and transmit data via an **Internet Service Provider** or **ISP**. Some examples of ISPs would be companies like Verizon or AT & T (these companies provide in the U.S.). These ISPs house their own data communication facilities called **Points of Presence**, or **POPs**, in local regions. These POPs just houses racks of routers and modems. Each POP gathers the data received from local users' devices and transmits this data further out in the internet infrastructure. And this works vice versa - POPs receives data from further out of the internet and sending them to their locally connected devices. The POP's functions are analogous to those of a local post office, but by using [modems]( URL_3 ) and [routers]( URL_0 ). The physical means for the data to travel between device and POP and then onwards, I'm not sure, but it varies depending on the existing local infrastructure and what the ISP can make use of. So what happens beyond the POP? These POPs, which belong to ISPs, are linked together with other POPs from other ISPs (by, again depending on the existing local infrastructure) along with data centers owned by governments and large organizations, at **Internet Exchange Points** or **IXPs**. IXPs houses [network switches]( URL_7 ). Just as POPs are like local post offices, the IXPs are like the larger sorting offices. (No single organization owns an IXP. The ISPs and other participants voluntarily agrees to link together for the sake of serving their customers and lowering costs, practicing what is known as [peering]( URL_1 ) . **You can check out an interactive map of the IXPs around the world by TeleGeography [here]( URL_6 )** The IXPs are then connected to other IXPs through [internet backbones]( URL_4 ). An internet backbone is made of fiber optic cables serving as principal routes for data to transmit at high capacity. Many of these fiber optic cables - [more than 550,000 miles of cable - are buried under sea to connect IXPs worldwide]( URL_2 ). **You can check out an a interactive map of the undersea fiber optic cables [here]( URL_5 )** also by TeleGeography. **TL;DR** **Globally: From device to local Point of Presence(racks of routers and modems) via an Internet Service Provider, to Internet Exchange Point(racks of network switches), to an internet backbone(under sea fiber optic cables), is how information is sent. Then from the internet backbone, it is received at a different IXP, POP, and finally device somewhere else on the globe.** Another key aspect of the internet infrastructure is how the information is sent – for example, a data file is not sent whole like mail. You should look up **I.P. address** and **data packets.**",
"Why do I have to pay long distance to call someone one state over, but can communicate with someone in Korea over the Internet for free?",
"It's a lot like how cars and planes move people around. There are streets that connect houses to other houses or to the city, cities are connected with highways or interstates, etc. There's no one road that everyone connects to,but the combination of all roads connects everyone (even if some are closed sometimes).",
"Imagine those Russian nesting dolls.Matryoshka The one in the center has the data you are sent. The one that contains it has your house number. The next one has the street The next has the town name/zip or postal code The next has the state/province The next has the country. So the data is encapsulated in layers. When you have data to you it gets to your country border and that layer is peeled off. Next it gets sent to your town and that layer is peeled off After that it gets sent to your street and that layer is removed until it arrives to your house and the data is handed to you. The sorting and shipping process is handed by exchanges, routing equipment and switches. I know it is vague and messy but I am on my phone.",
"There are a few ways. There are boats that actually put cables under the sea, and these cables carry our internet across the world where land isn't walkable. From the ISP to your home, from the ISP to other ISPs, from one nation to another - Cables are the most common connection. Other options are Satellites. We use satellites to 'bounce' signals off of so that we don't have to lay cables. Satellites come with a delay though - the travel time for the signal is very long, so doing things like gaming, two-way video, etc are all slowed down, or unusable. This is commonly how the US Armed Forces get their internet in the middle of no-where. (including at sea!) Then there is shortwave. Things like \"cell phone internet\" and radio towers. Microwave towers (those giant sea-shell/drum-shaped items on towers? Microwaves!)We use microwave towers to beam signals across the earth when laying cables across the same expanse is too costly, or impractical to maintain. We can also use cell phone like internet from these towers. These towers can be expensive to set up, and are often used in mountainous places. When you access URL_0 from the UK, you go over copper wires from your house (or over the air to your cellphone tower), to fiber wires at the street, to your ISP. These go over more fiber-wires to the oceanic coastal ISP who has a trans-atlantic cable. Your signal goes over this cable. Then it goes over more fiber cables in the US until it reaches the datacenter in the with URL_0 on it. It goes from the fiber back to copper at this datacenter (or maybe staying fiber) and connects to a physical box that serves of URL_0 for you. Then the data goes back to you. This travel process (forward and back) takes < 500 milliseconds. If for some reason any of the connections on the way to reddit and back stop working, the internet is designed (where the term web comes from) to use another route that exists, just like you being able to take another road when one is closed. Here is a website showing you how the world connects by wire! URL_1",
"This question is very broad, but I'm going to focus on routing, or how the devices know which way to send traffic. I'm also going to focus on the large scale (network to network) instead of how the packet moves around within the network. In other words, I'm going to focus on how data might go webhost-provider - > Level3 - > Spectrum (my ISP) and gloss over the fact that someone like Level3 is actually made up of many devices internally. There are two basic problems. We need some sort of address for destinations, and we need some sort of way to know which direction we need to send data for it to eventually reach the destination. Addressing is actually pretty simple. We just use numbers. To keep it simple, we assign out these numbers to networks in large ranges. When you see people talking about IP addresses, those are the addresses, and when you see subnet mask, that is the range. Even though IP addresses and subnet masks are presented to humans as 4 numbers each, they are each actually just one large number that is being converted to 4 small numbers to make it easier for humans. So, the IP address identifies a specific destination, and if you add a subnet mask you can express an entire range of destinations, and you only need two numbers to do this. The second problem to solve is how everyone knows how to reach everyone else. Each large network has routers that use a protocol called BGP to communicate this information. Since IP and netmask together make up an entire range, routers don't need to remember every single IP. They can think (and speak to each other) in large ranges. When networks connect, they trade the entire contents of their BGP routing table. This table contains all of their own ranges and also all of the other ranges they heard from everyone else they connect to. If a network hears the same range can be reached by two paths, it picks the best one and puts only the best one in the table. In this way, every BGP network on the Internet has an entry for every single range that any ISP in the world says can be reached through them, and that table also says which connection is the best path. The table is big and growing: URL_0 For the most part, the big BGP routers on the Internet will have that entire table in their memory. At this point, we've established a system where everyone has an address, those addresses can be expressed in large ranges, and every network has a lookup table that contains every range and which direction to hand off the data for that range. So, the actual process is simply to receive a bit of data (a packet), look it up in this table, and then hand it off in the direction indicated by the table. When that packet reaches the next network, it simply repeats the exact same process of looking up the destination in the table and sending it off in the direction indicated. Source: Am a network engineer. I'm currently sitting in a room with the people who run the Internet. Well, most of them, and in North America at least. :) I'm at the NANOG meeting in Washington, DC.",
"The internet is routed. Each router in the network only cares about its connected devices and their addresses. When a packet comes along the router only knows to hand the packet off in the correct direction.",
"Play a game with your classmates. The rule is that you all can only pass messages to your neighbor and only the teacher can pass the message to the other classroom. Each class room is a country. Your classmates are local.",
"Network engineer here, the internet is a combo bubble hyper node machinerator which coagulates the modems and transmogrifies them down the super information highway -- essentially a series of tubes. A common misnomer for internet infrastructure is that it's similar to a large van or lorry that computers just dump things on. I can tell you it's neither of these things (i'm a network engineer, in case you didn't see before).",
"The internet is a network of networks. A network is just someone with a bunch of computers with website on them, or a bunch of people who want to reach websites. When two networks physically connect they tell each other what's on their own network and other places they are conected to and can reach, with that informaiton they agree to swap traffic to get it to the right place. because every network is connected to other networks traffic can always find a route to where it needs to be.",
"So many network engineers TTH for an ELI5! The ELI5 answer is that routers of varying capacities, from your cheap home modem to the big carrier grade devices , send packets across various media types towards the the direction of a requested destination. The \"internet\" has a converged addressing schema that provides instructions on how to arrive to a given address, a path. That explains the transit. Content is provided by warehouses that carry computers connected to the same network. These routers and addressing schemas provide knowledge on how to send information between you and those computers. Finally what really makes it the \"internet\" is the distributed global participation of adjoining sub networks. Or as /u/ollybee pointed out the internet is a , \"network of networks\". You need not concern yourself with the stupendous amount of minutiae in ever changing media types (fiber, coax, ethernet, w/e) or furthermore the varying capacities, models, or brands of routers. That stuff gets into the weeds and becomes off topic from your question as everyone's situation is different. Since all the routers are speaking common languages we don't need to concern ourselves about the media types except for on a case by case basis defined in requirements."
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5sohcc | What would happen if every country in the world had the same currency? How would things change? | Repost | explainlikeimfive | {
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"Eurozone nations share a currency, so they can't individually print money to pay their debts. This is a major weakness; it means they sometimes default on debts, which nations such as the UK or US never will. A further problem is that the movements in the currency's value, interest rates etc. that best serve one nation won't be right for another. If the whole world had one currency, it would be like the Eurozone on a larger scale."
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5splpa | Why is the majority of the world right handed? | Repost | explainlikeimfive | {
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"\"The right shift theory and developed by psychologist Marian Annett at the University of Leicester, suggests that a single gene increases the likelihood of being right-handed. \"The essence of my right shift theory is that there is a gene that helps to develop speech in the left hemisphere of the brain and increases the probability of right-handedness,\" Annett told LiveScience.\" There's a common myth that swords and shields are a huge factor (shield in left hand protects the heart, right hand to attack). But there's a lot of evidence that right handedness existed long before then."
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5spv7s | Why can't we go back in time? | Repost | explainlikeimfive | {
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"This is an unsolved problem in physics. Really. The mathematical equations that describe physics generally work just as well backwards in time as they do forwards, so it's not immediately apparent why time only goes one way. If a system would do *this thing* going forwards in time, you can just flip the signs and infer that it would do *the opposite thing* going backwards in time. This sort of thing is at play in the claim that going faster than light would take you backwards in time. That's one way of interpreting the math, but it may not really have any material meaning if it's impossible to accelerate anything *to* the speed of light, let alone past it (doing so would involve an infinite amount of energy). The single-direction nature of our movement through time is known as the **arrow of time**. It's connected to the second law of thermodynamics - the idea that entropy always increases. But for a more fundamentally satisfying \"why\"? Good question. URL_0",
"If I could add to this question. If time is considered an extension the three dimension onto a fourth, wouldn't putting something into the past take an infinite (or at least gargantuan) amount of energy?",
"So you have a piece of paper, the topside represents the future and the bottom side represents the past. As these two segments of time are separated by the piece of paper itself, you can't really go back and forth from one side to the other. The only way to interact with the segments of time would be to poke a hole through the paper. Good luck poking a hole through the universe."
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5sqib5 | What happens when you "get the wind knocked out" of yourself? | Repost | explainlikeimfive | {
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"It usually happens when an impact (be it falling or getting hit) temporarily paralyzes your diaphragm, making it difficult to collect enough air. It's called getting the wind knocked out of you because it *feels* like the impact forced all the air out of your lungs."
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5srowe | How can gorillas and other herbavores get so big and muscular from a diet of essentially leaves and plants, while vegan humans tend to loose muscle mass on plant based diets? | Repost | explainlikeimfive | {
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"Nobody here has addressed the genetic basis and control of muscle mass and buildup in response to testosterone levels. One reason for example that a male gorilla simply builds muscle easily is because their muscles do not atrophy as easily and \"build\" with much less limitation for little exercise.",
"Do people who follow vegan diets properly actually lose muscle mass? Because I don't think they do. There are people who eat tons of meat who have no muscle mass whatsoever. And humans and gorillas and other herbivores have a different physical make up... regardless of diet.",
"There are a lot of misguided responses here, so I figured I'd add a little more science to some partially true responses. First: you lose muscle if you don't use it. The human body won't maintain above a certain level of fitness without constant stimulation, to save resources. Second: the great apes are omnivores. They eat bugs, and anything small enough that they can get their hands on. Often this includes rival apes, especially their young. Third: humans have a great deal of stabilizer muscles. We sacrificed raw strength for the ability to interact with the world with incredible dexterity. To address the misinformation... First: We can extract plenty of nutrients from everything we eat. However, the reason we treat food with heat (ie cooking) is to make these nutrients more readily available. We cannot break down the parts of plants that are incredibly tough (cellulose), but this is something that is rather exclusive to herbivores. it requires a great deal of specialization (like the cow and its four part \"stomach\") and a LOT of plant matter to be worth it. they also repeated grind and mash their food during digestion (chewing their cud). our bodies are very adaptable to different diets, especially during infancy. there are some incredibly interesting studies on human gut bacteria that are worth checking out here Second: you can live just fine on a vegan diet. many people need supplements, because it can be time consuming and expensive to get a complete array of required nutrients from just a vegetable diet alone, but it is very possible.",
"One thing i feel the compulsion to point out is you listed gorillas specifically as herbivores and they are not Great apes ( gorillas, chimpanzee etc ) are omnivorous, while they do exist largely on a diet of fruits and vegetables they will not pass up adding insects and even the occasional small monkey to their diet if readily available",
"People like [Patrick Baboumian]( URL_2 ), [David Carter]( URL_0 ), [Kendrick Farris]( URL_3 ) and [Billy Simmonds]( URL_1 ) show that humans don't necessarily lose muscle mass on plant based diets.",
"Vegan humans don't lose muscle mass. Plants and animals share the same amino acids (as does all life) and therefore if you eat the right plants (or enough plant) you can get all of the nutrients you need.",
"Gorillas aren't the only ones. Bison, cattle, elephants, and many other very large animals develop massive muscle and bone structure on a plant-based diet. Think about how large and powerful a horse is, and it isn't even one of the really big ones. Also consider that they all eat a TON of food and must spend most of their waking hours grazing. Humans don't have to do that. Gorillas eat about 40 lbs of vegetation every day. We'd die if we tried that. Our teeth wouldn't last. So even if there is less nutritional value in much of their diet, the quantity makes up for it. I don't know the scientific details, but their systems have evolved to metabolize the nutrients in their diet into powerful muscle and bone mass. We develop muscle and bone too, but obviously our conversion process is unique to us, just as it is with every other animal. I realize this isn't a direct answer, but hopefully gives you more to think about...",
"I do not know how to say this without looking like a douchebag.. but I'm vegan and I have a LOT of muscle mass. Vegans have the skinny stereotype, but muscle mass really depends on metabolism body types (ectomorphic, endomorphic, and mesomorphic). Again, I'm not trying to be one of those annoying vegans who preach about what I eat, but the skinny vegan is definitely a stereotype.",
"I think this is more of a question of culture and lifestyle than biology. There are flabby and weak humans who eat meat. There are vegan body builders who have significant muscle tone. Most vegans I've ever met do not work out. They would have muscle if they worked out.",
"For my two cents worth, I'd say the largest difference is lifestyle. Humans of any sort live very different lives to gorillas. Gorillas just east, shit, bang and run around. Humans do the same, but with a lot more sitting down ( generally). Anecdotally, since going vegan and working out more, I have lost fat and weight, but my muscle mass is increasing If I just ate lettuce and didn't exercise, for sure I'd be skin and bone. But so would most animals",
"> vegan humans tend to loose muscle mass on plant based diets Evidence? (Like actual evidence, not some gym bro gossip) Never heard this claim before",
"It is all about net hypertrophy. The easiest way to answer this question is referencing the human mutation to the MSTN gene (myostatin-related muscle hypertrophy). Normally, humans atrophy at a greater rate than most animals for good reason, we are not a labor intensive species anymore. Myostatin is a protein encoded by MSTN that, when received on muscle cell receptors, inhibit muscle hypertrophy. The mutation to either the MSTN gene or the receptor that receives myostatin prevents this inhibition, causing full net muscle hypertrophy. You can see these effects in cattle, certain dog species, and even a handful of humans across the world (see worlds strongest toddler). Gorillas are genetically encoded to not go through muscle atrophy by limiting the amount of myostatin produced.",
"What vegan humans tend to lose muscle mass on a plant-based diet?",
"I mean as a vegan my muscle mass has gone up since I became one. I used to be baby fat pepperoni pizza body. Now I only have A little chub and muscle",
"1000 calories of Broccoli is still 1000 calories. Might be 6.5 lbs worth, but the numbers are there :D",
"Watch vegan gains if you are interested in learning how the body is supposed to be on a plant based diet, how the body is not built for eating meat, how the body can build muscle with plant proteins, and how to live a vegan lifestyle. Building muscle being vegan is possible and not hard at all.",
"BACTERIA! I'm surprised nobody has mentioned the role of bacteria in converting plant matter to energy. When this question was asked in r/AskScience several years ago, the top answer was enlightening: URL_1 Look at a gorilla's stomach - it's a have huge fermenting vat. Also see [here]( URL_0 ) for an answer slightly above 5-year old level: > The gorilla has six times the absorption available from the colon than does the human, which also means they have many times the amount of bacteria available for digestion of plant cellulose. The high fiber in the gorilla diet is fermented by the colonic bacteria, yielding short chained fatty acids (SCFA). In other words, the indigestible carbohydrates are converted to saturated fat and absorbed into the blood. A human eating a similar diet would just end up crapping most of it out, receiving little benefit. > The gorilla can obtain about 65% of their energy from their hind-gut, whereas the human only receives about 10% from the colon. The butyrate created in the human colon is mostly used locally by the cells of the intestinal lining and only a very insignificant amount is absorbed. This is why a human can live without a colon and an ape can’t. (see my post “The Planet That Went Ape!” for more on ape vs. human gut ratio)",
"I have been vegan for four years and I have never lost weight. As a matter of fact I gained 24 pounds. The mistake lies in thinking we only eat leaves and lettuce. But I don't blame you",
"Pretty simple. True herbivores have the digestion system to handle such a diet. A herbivore has intestines up to 20 times their height/length. Human, like most omnivores, have about 6 times (so 30-35 feet for us). Carnivores have about 3 times. Herbivores are by far better suited to digest plant matter."
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5ssuco | Why do subtle vibrations on the road put us to sleep so easily? | Repost | explainlikeimfive | {
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"Gentle rhythmic movements work just like rocking a baby to sleep. The road noise also provides a white noise effect that helps you tune out other city noises that might making sleeping harder."
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5sw4di | Do cell phones really give you cancer? Is there enough supporting evidence to say if it does or not? | Repost | explainlikeimfive | {
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"If you are asking if the electromagnetic radiation transmitted and received by cell phones can cause cancer in living organisms, the answer is no. This is because the wavelengths used for cell phone communication are too long, which is another way of saying they are too low energy. There are different types of EM waves: Radio, Microwave, Infrared, Visible, UV, X-Ray, and Gamma. These are not hard cut-offs but general spans of radiation. Each category can do different things to atoms/molecules/nuclei. Here's a brief description of each. Radio waves: Nuclear atomic spin transitions (these have no practical every day use to lay people but are very useful in science). Microwave: Molecular rotational transitions which cause molcules/atoms to rotate/spin. In microwave ovens, this causes water molecules to rotate and when they bump into each other, this rotational energy is converted/dissipated in other ways (see next). Infrared: Atomic translational and bond vibration. This is generally what we perceive as temperature. Up until here, nothing too dangerous can happen. Visible/Ultraviolet: electronic transitions. What this means is that the electrons in bonds get excited. This generally makes molecules more reactive and they can go off and do bad things. Your DNA making random bonds with other things is not a good thing. This can cause cancer the more energetic the radiation is (UV or higher) X-rays: Higher energy electronic transitions. UV radiation generally deals with outer shells of atomic electrons. X-rays can excite/eject core shell electrons. The amount of energy imparted could cause molecules to break apart and at the very least generates very reactive states that can go off and do bad things. You don't want this happening to your DNA. This can cause cancer. Gamma Rays: This causes nuclear excitations. This is not like the spin state change in radio waves. This type of radiation excites protons/neutrons to higher energy states which can cause the nucleus to fission or dissipate the energy in other ways which can generate reactive atoms/molecules. Nuclei blowing up in your DNA is not a good thing. This can cause cancer. So in summary, the radiation sent/received from cell phones cannot cause cancer because the radiation sent/received is incapable of hurting your DNA."
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5swk12 | Why does air get cooler as it goes through a fan? | Repost | explainlikeimfive | {
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"This has been answered many times. It doesn't , the wind carries away heat from the skin which we feel/understand as cooling when in fact the room temp is the same. Even worse, the motor actually heats up a closed space :)"
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5sxzxa | What is the dark web vs. deep web? How exactly do you get there? And how dangerous is it if you don't know what you're doing? | Repost | explainlikeimfive | {
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"the dark web refers to the part of the internet that requires using the TOR routing service to gain access. Once you have access it is much like the rest of the internet only generally targeted towards much more shady things and conversations that people want to remain anonymous for. the deep web refers to all parts of the internet that are unindexed, that is to say are not publicly accessible to just anyone. Every page and post on reddit if properly searched for can be found on google and therefore indicates that it is indexed. Companies have many web pages, documents, and data that require special credentials and logins to access. The deep web refers to all of these various pages and locations. If you're a member of a private forum that requires you to log in to see information, congratulations, you've been to the deep web and there is nothing dangerous about it. If you've downloaded the TOR software and connected, congratulations you've been to the dark web. the level of dangerousness is correlated directly with the activities and websites you visit, though largely harmless you may find yourself on a list at some government agency :p"
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5sy33l | What creates gravity | Repost | explainlikeimfive | {
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"If you figure that out, enjoy your Nobel Prize. We can quantify gravitational force, but are yet to discover what causes gravity. The working hypothesis is that there are massless particles called gravitons that emit gravitational fields, but we've never been able to detect one."
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5syfnt | When did humans start kissing each other & what was the initial purpose for? | Repost | explainlikeimfive | {
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"Baby has virus. Mom kisses/licks baby. Mom gets virus. Mom creates antibodies against virus. Breastmilk contains antibodies. Baby survives to reproduce. This is the leading hypothesis, then most likely it was seen as a sign of affection and it blew up from there Edit: this may have been pre human and our primate ancestors did it",
"Its believed that kissing is linked with the food needs of the baby birds and the way their mother feeds them. Im pretty bad at explanations, so heres a video where is explained pretty well. I hope i've been helpful! URL_0",
"The most primordial instincts of any species are survival and reproduction. The mouth is one of the first organs to develop in the fetus. That's one of the first things that a baby learns to control, is highly complex and has a lot of nerves. We use the mouth for feeding, tasting, communicating, displaying emotions, sensing our environment and even attacking. The mouth is also a notable erogenous zone. Therefore, it's not surprising that it has a prominent role in social interaction. **When:** possibly as soon as our ancestral species developed affection. Many species interact socially with the mouth either by touching, licking or biting. Even birds interact with their beaks. Kissing itself is just another development of these actions. **Initial purpose:** I guess the purpose of kissing should have been always the same as today. And it's intimate nature certainly helped on the development of the immune system which emphasized it's survival role further down in the evolutionary process.",
"Some scientists believe that kissing originated as a form of giving food to the kid. The mom chews the food for the kid and the kid eats it, just like how bird moms do. This creates antibodies in the mom which goes to the breast milk and that passes on to the child, making it stronger. Although today it's considered gross, it's not a bad thing if your mouth's clean. VSauce explains this very well: URL_0"
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5syqe7 | How did map makers make maps and know the shapes of the continents before satellite images? | Repost | explainlikeimfive | {
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"Well, they didn't to be honest. The earliest map makers were elites at using compasses and measuring distances visually to determine the shape of a coast line or a river ect, but they never were to accurate. If you look up examples of old maps compared to sati lite imaging it's wildly different. Mapping the middle of the ocean would prove to be a lot harder though, some how they still did it. The early map makers could decipher there position on the globe by looking at the locations of constellations compared to the location of the constellations at home. All in all the people who made the maps spent their whole lives making them.",
"On top of what the other commenters said, the United States maps were very accurate in the late 19th century because mountains and hills were used to develop a carefully triangulated network of reference stations, [see here]( URL_1 ) for the reference stations between California and Colorado. Surveyors were literally on top of mountain peaks with very heavy theodolites, supplies, and equipment for days on end, taking careful measurements of all the other reference stations over distances of 100-200 miles. If you dig around you can find stories of these surveys, they were often extremely difficult and surveyors sometimes got killed on these mountains. Using these triangulated reference stations, math and very careful measurements was what made the maps so accurate. Using these stations as reference points they could fill in the smaller scale details in the local areas. The British likewise had triangulation surveys... [here is one such map of India]( URL_0 ) in 1870. You can see lines extending northward on the top right side of the map. Nepal was off limits to the British, and these lines were attempts to measure the Himalayas from a distance, including Mt. Everest. These were all surprisingly good measurements."
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5szbjp | Why were plants so big in prehistoric times but evolved to the size they are now? | Repost | explainlikeimfive | {
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"Back in dinosaur times, there was a lot more carbon dioxide in the air (like 5x as much). Plants literally make themselves out of the carbon in the air (they take in CO2, put out Oxygen during photosynthesis. They use the carbon they take in to build their plant body). As the atmosphere changed, there was less CO2, so there's less stuff to make plants out of."
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5szuuf | If the Universe is 13.8 Billion Years old - How did it grow to be 46 Billion light years wide? | Repost | explainlikeimfive | {
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"URL_0 Look at this video, it will explain well with visualisation. But basically, space itself is expanding. You can't really calculate the speed at which space expand, but you can use two point of reference (a star and our solar system for example). What happen is that every volume of space is expanding, so the more distance between these two object, the more volume of space there will be between the two, more volume that all expand, making the speed at which those 2 stars are getting further away faster. At some point, those two star are getting further away at the speed of light and it's at this moment that they emit the last photon we will ever see from earth. But space will continue to expand pushing that star even farther away. By the time the last photon reach us, that star will be even further away. The light from star 46 billions years away is the light that they emitted before they were getting away from us at the speed of light. And yes nothing can move at the speed of light in space, but it's the space that expand, dragging the stars with it.",
"The growth of the universe is not limited by the speed of light. That is the speed limit inside the universe but the universe itself can expand faster"
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5t00rf | How exactly does an EMP disable electronics? | Repost | explainlikeimfive | {
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"This has been asked [a few times already]( URL_0 ). Here's one of the answers: > An EMP is simply a massive burst of EM. > EM is Electromagnetic Radiation. This is the generic term for Radio Waves, Microwaves, Light, UV, X-Rays, and Gamma Rays. All of these are fundamentally the same thing. They're all just photons given off by ions. But what they're called by us humans is determined by their wave-length (we call this color). > Your EMP is a very bright FLASH of a board spectrum of EM radiation (so radio waves, microwaves, etc.). This energy is Electromagnetic so it interacts with electrical hardware. This is how mankind is able to build cellphones, radio stations, fiber optic cables, digital x-ray machines, etc. > When you send out A LOT at once. You overwhelm the sensor frying it. If you send out EVEN MORE you make wires behave like antenna. This overloads an electrical circuits frying them.",
"The simple answer is that an EMP causes strong electromagnetic fields that can cause a huge power surge in electronic components. It basically overloads and thus fries them.",
"Every wire is an antenna. And if you send a strong enough radio signal you can create very high voltages though that antenna and damage any components connected to the antenna.",
"I probably have a 5 yr olds understanding of this so here goes. When an electrical conductor moves through a magnetic field electricity is produced. This is how a generator works. You have magnets around a coil of wire and spin the wire around inside the magnets field. So if you have an electrical conductor and hold it still but move the magnets around, you still have a conductor moving through a magnetic field which creates electricity. So as the magnetic field moves away from the source of the EMP, every conductor it moves through will generate electricity. Look at a circuit board and imagine every line on the board having current run through it simultaneously at levels it's not made to withstand.",
"So I'll let you in on a secret. You remember how big independent flashes on cameras have a weird beeeping sound after they go off? That's the sound of the flash \"recharging\" back to full capacity. It basically stores energy in a capacitor/inductor and then releases it all very fast once the camera's button is pressed. Similarly, in an emp generator, we gather a large amount of charge and discharge it quickly to create a pulse of energy which creates a massive current in the device you point it at, frying them up."
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5t155i | Why do things physically hurt more when we are cold? | Repost | explainlikeimfive | {
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"Your body is filed with thermoreceptors to detect the temperature. You have 2 main thermoreceptors for cold: regular cold thermoreceptors and extreme cold thermoreceptors. The second one, extreme cold, sends pain signals to your brain. So when it's cold and something hurts you, your brain is getting 2 different pain signals that compound with each other"
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5t1rgi | If the universe is constantly expanding, what is it expanding into? | Repost | explainlikeimfive | {
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"Let me get right to the point, the universe isn't expanding, it's stretching, and there is a difference. Expanding is a terrible word to use, but it's the easiest, shortest path to express to the layman through media the concepts behind what we observe, that everything is moving away from us in all directions. And it's not that things are flying away from one another like sparks of a firework being blasted away from each other, but instead that if the universe were a surface those sparks sat upon, it's that surface that is moving, carrying the sparks with it. For those who have the intellect to ask, \"expanding into what\" is a very reasonable and the logical conclusion. And you are correct for asking it. But that's the trick behind the concept of an infinite universe. Let us not forget that the \"Uni-\" in *uni*verse means *one*. Even the speculative \"multi-verse\" theory is still encompassed by one reality, and that is the universe. There again lies a slippery slope sold by the common media, because people struggle to even grasp the idea that you can have more than 3 dimensions at right angles from one another (learn what a matrix is in Linear Algebra to understand this), it's just easier to say \"somewhere out there, if you travel far enough, you might come across another universe.\" That's *really not what they meant*, but they also had to pull a scratch lottery in Alabama that was arctic themed because a significant number of players couldn't grasp the concept of what a negative number is... No, the universe is infinite, and fixed in size at infinity, and we're seeing a stretching. If you need an analogy, let's use the old inflating balloon. Instead of thinking about how it's being filled with air, and thus expanding into the adjacent space, the balloon is fixed in size and rather elastic - a balloon that's under inflated. If you draw some dots on the surface and then stretch the balloon just where the dots are, you will see that you get the same expansion behavior while the volume in the balloon remains the same size. And you can stretch the whole balloon without changing it's volume, if you just grab it by two ends and pull. The analogy breaks down because we necessarily have to manipulate the balloon in 3D space, when really it's only the surface and the volume of the balloon that are the important factors. There's a whole branch of math dedicated to this called Topology, and it's a very hot topic for math research.",
"Nothing. It's just... expanding. Let's say you have a row of blocks. 5. You insert a block in between each. You have to spread - or *expand* - those blocks apart to make room. Now you have 9. Do it again and it expands again and you have 17. And so on. But imagine that row of blocks was infinitely long. You can still insert blocks in between making it \"longer\" (though it's still infinitely long). And instead of a row of blocks imagine a grid and you are expanding in both directions. Then imagine it in 3-dimensions and you basically have what is happening to the universe. Instead of blocks its space itself.",
"It's easier to think of this in terms of time. Today is Feb 9 where I am. History is the time behind today. History is expanding at a rate of 1 day per day. It's not, however, expanding into something. It would be wrong to say that Feb 11 is \"there in history waiting to be observed\". We've agreed that we're going to label whatever happens Saturday with Feb 11 when the history is recorded.",
"A new theory is actually evolving somewhat into a universal wobble, where the universe expands and contracts continuously. Wrap your head around that one. Basically, the current popular theory is that universe is expanding into empty space. Or maybe it's a single point that is not expanding and we are all just data in virtual space or a hologram or a simulation. Or the universe stays the same size and the bending of space due to gravity \"simulates\" an expanding universe and masses and energies distribute themselves throughout the universe. That's my personal favourite."
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5t2pma | Why are precious metals still so valuable despite no longer being used as currency? | Repost | explainlikeimfive | {
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"Solely because people are still willing to spend so much to own them. Inherently they're worth nothing, they only have value because we say they do."
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5t2sco | Why is black pepper nearly as universal as salt as a seasoning for savory food? | Repost | explainlikeimfive | {
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"Peppercorns are easy to transport and keep fresh, which mattered a lot more in the Middle Ages to 1940. Because it was one of the few spices that was widely available, it became a staple in recipes.",
"Black pepper acts as a flavor-balancer. Not every dish requires it, but dishes with stronger flavor profiles tend to benefit with the addition of a little black pepper. Let's take a look at a classic dish: strawberries and cream. Typically, the cream overpowers the strawberries. Adding a little black pepper helps balance the sweetness of the cream with the natural flavors of the strawberry. TL;DR It helps with dishes that can easily have imbalanced flavors."
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5t411m | Why is there a flu "season"? Also, do other viruses and bacteria have time frames during which they are more active? | Repost | explainlikeimfive | {
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"It's cold outside. Everyone goes inside to be warmer, and to avoid hypothermia. Now you have many people concentrated in a small area. Germs now pass along easier. Viruses die quickly without a host but now they can find hosts easily."
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5t55h3 | what happens to all those amazing discoveries on reddit like "scientists come up with omega antibiotic, or a cure for cancer, or professor founds protein to cure alzheimer, or high school students create $5 epipen, that we never hear of any of them ever again? | Repost | explainlikeimfive | {
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"I'm a scientist! So let me try to offer my insight: So first of all, like every other job in the world, scientists need money in order to work on their projects/research. Unlike \"regular\" companies though, scientists don't really *sell* anything, so it's going to be hard to go to Wells Fargo and ask for money without being able to show them how you plan on paying them back. Enter organizations like the National Science Foundation (NSF), the National Institutes of Health (NIH), Defense Advanced Research Projects Agency (DARPA), NASA, the European Commission, and the list goes on. These organizations have many purposes, and one of them is to allocate researching funding to promising projects. What they'll do is, for example, put out a \"call for proposals\" and then allow scientists to apply for funding. For example, the NSF might put out a call for proposal on the subject of say \"childhood education.\" So you're a scientist doing research in \"teenage education.\" You have a lot of experience on research in education in teenagers, and you think that you might be able to apply your work to education in children as well. You just don't have the time, or money, or staff, to actually do it. But now that there's this call for proposal, it's your chance! So you write a grant proposal which basically outlines what you are going to do, how you are going to do it, why you are going to do it, and a lot of other things are involved. Will your project involve any ethical considerations? You'll need to include documentation showing how you will follow ethical approvals, for example. You'll also need to submit some kind of budget guidelines. If you are requesting $500,000, how will this be used? $500,000 sounds like a lot, but in terms of research it's not really. The NSF might award you the grant for $500,000, but you need to keep in mind that this money is for the duration of the project. Do you need equipment (you will)? Do you need lab space (you do)? Do you need to hire new staff (you might)? New staff could be other researchers or grad students to help you. They need to get paid, after all, and so do you. In the end: my point is: we **need** money just like everybody else. But unlike Boeing, and unlike Intel, and unlike Apple, or Google, etc... the money that I am asking for to do my project, actually has no promise of monetary return to my investors. What I promise to return to the NSF, or to NASA, etc, is the promise of advancement in research. I do this by using the money to conduct experiments, and then publishing papers about it or giving talks at conferences. From the journal articles, other scientists will be able to follow my findings and either use it or try to test it etc and build upon their own research. From the conferences, I show things that are essentially \"works in progress\" but hey, maybe my idea is exactly what someone else was missing, and if they see me talk about it, they might come find me later on (or email) asking to collaborate. These are things that we *all* benefit from (we as in scientists), and these are essentially the \"returns\" that I promise to the NSF when I write my proposals. When I publish or talk at conferences, I am talking to my peers. I am talking to colleagues. I am talking to scientists. When I talk to my peers, I would never make claims like \"this line of research can, **will**, definitely improve childhood education by 500%!\" When I talk to my peers I am trying to discuss my work. But when I am talking to media (be it the press, a TV program/interview, Twitter, my personal website/blog, message boards, or my university's press office, or hell, even my own non-scientist friends and family), I am not trying to discuss my work. **I am trying to sell my work.** I want to sell my work because, like I said, my work is entirely based on receiving money. Without money, there is no research, period. So I might exaggerate a tiny bit, or trump up all the benefits of what I'm doing and then throw in a very minute detail about how those gains are the theoretical maximum assuming that all the planets are aligned. I'm not really lying about anything, I'm just giving a, perhaps very, optimistic view of my research. (After that, the journalists usually run off with it, and replace words like \"could maybe\" or \"might possibly\" into \"will definitely\" and so on.) When I apply for funding, I like to think that the system is merit based, as in they'll review my track record and past research and so on. In general this is more or less true. So I'm not actually trying to sell my work to these agencies like NSF etc. Who I'm trying to sell to is to both the tax paying public and to the politicians in charge of appropriating money to the NSF. Since I am not making anything, or selling anything, I need to convince the public that their tax dollars are being used in a productive and/or beneficial manner. I need to convince the politicians not to defund the NSF, because I need that money to do my research. I need to convince the public that my work is crucial, vital even, so that they might complain loudly when a politician decides that they want to cut funding to the NSF.",
"Beyond what people are writing about the huge investment these things take, the truth is often that these \"discoveries\" are nonsense. For example, often you will hear a story about a \"miracle cure\" for such and such. But if you look deeper, the story is reporting on a lab experiment testing the drug in cells in vitro which may have a novel or promising mechanism of action...but that's a far cry from repeating its success in other studies, much less animals and much less demonstrating effectiveness in treating human diseases. While that does take years and some of these drugs are ultimately successful, the vast majority are abandoned down the pipeline because they aren't as effective as was hoped. You see another version of this with claims about \"new drug treats so and so with virtually no side effects.\" That may be true in clinical trials when its given to a limited number of people...but once the drug hits the market, who gets it? Many many more people. Elderly. Children. Pregnant women. People of various ethnicities, not to mention just many more people with varying genetics. Everything has side effects and some of them are pretty darned serious. You'll see articles about cures for cancer that are developed. But the stories are misleading because they are really talking about preliminary success in developing a new strategy to target one specific type of cancer. Even if it passes muster throughout its years of development its impact is going to be pretty limited. You'll probably never know of its usage unless you or someone you know eventually comes down with that specific disease. For example, researchers in Glasgow and Hong Kong last year discovered that injecting a protein into mice brains could reduce amyloid plaques. That's important work. It's all well and good. But doctors aren't sure that amyloid plaques cause Alzheimer's or are just another symptom of the disease. In the unlikely event we find a way to increase the expression of this protein in human brains and in the unlikely event it removes 100% of amyloid plaques, it might turn out to have 0% effect on curing Alzheimer's...and it will be years before we find that out. These stories are amazing because the media wants you to read their website so they publish interesting yet mundane stories in an overly sensational way. EDIT: I did not mean the discoveries themselves were nonsense. I meant the media is overdrawing the conclusions of preliminary evidence to nonsensical levels. Should have phrased more carefully.",
"It depends. Sometimes the stories are misleading, say for instance they've made a small breakthrough but the research still needs more time and/or human trials, but the story published makes it sound like it's available on the market right now. Sometimes it's just a grab to get people to a site and it's a whole lot of rubbish.",
"Pharmacist-in-training here. At least in the field of medicine, all new methods of treatment must be \"evidence based\" meaning someone has to take that new thing and compare it to the one currently available. As an example, comparing the how well the $5 epipen works against a typical $30 one. For this reply, let's ASSUME the $5 epipen actually works and isn't a sham. This process is called a \"Clinical Trial\" and often costs millions of dollars because you need to recruit hundreds, if not thousands, of people to use your $5 epipen or the $30 epipen and check back for results and such. This often requires hundreds of staff members, facilities, tools, and even the pens themselves, and if I'm not wrong, not many high-school students or even adults have millions of dollars they can invest into this process. It's the same for the new omega antibiotic, cure for cancer, or protein to cure Alzheimer's Disease. Regardless of whether it works or not, in order for it to be regularly used, it takes years of work and lots of money, which is why these \"amazing discoveries\" are rarely followed-up.",
"When I was a 'journo' I'd use sources like URL_1 to find nice stories that I could rewrite so they were unique and then promote them on social media sites. Eurekalert is already Buzzfeedy in its headlines, and you can tell when you read a little deeper into the article that the research was not as groundbreaking as the headline makes it appear. It might be a mouse model, it might be just a survey of 2000 people, it might be a study involving 20 people. Then when I wrote it up, I would purposefully try to avoid anything that highlighted how meaningless the study was, and I'd try to write something even more Buzzfeedy than the actual article. AIDS cure 'around the corner', 'Study: AIDS can be cured by bananas'. If I put some of the headline in 'snatch quotes', i.e. apostrophes, or put a colon indicating that someone had said something, i.e. 'Cameron: Fuck Daesh', then I would have covered my ass from misrepresenting the topic, provided I didn't totally misrepresent it. And I was churning out 5,000 words a day, often researching and spinning a 200-word article in 20 minutes. I would honestly just skimread the original source, I'd only actually read it to fully understand it if I was personally interested in the research. Furthermore, my understanding of complicated science is nowhere near good enough to be able to criticise a scientific study, all I'd do is 'spin' it. Churnalism, it's called. Shockingly, one of my skills is being able to push things to the top of Google search results. Quite often, when writing something more meaty, my research would be reading whatever was at the top of Google search results, which I know full well is written by someone who's just as big a moron as me and who's just as pressed for time as me. tldr, the internet is a tapestry of bullshit. .... Here's an example, in fact if I was spending 20 minutes on 200 words I would've spent 5 of them on Facebook. URL_0 See it's all full of confusing stuff but I might think 'this is the kind of thing people will read'. This doesn't comply with all the rules of news writing but it's pretty close: Could e-cigarette users face a higher cancer risk than smokers? Alternatives to tobacco, such as e-cigarettes, have become increasingly popular in recent years, and are much-touted for their health benefits. However, a new study, which found that smokeless tobacco users have higher levels of carcinogens than smokers, could end any claims that alternatives to cigarettes are better for you than cigarettes themselves. The research, which was published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, found people who use smokeless tobacco have higher levels of tobacco constituents cotinine, NNAL and other deadly toxins than people who exclusively smoked cigarettes. Brian Rostron, PhD, an epidemiologist in the Center for Tobacco Products at the U.S. Food and Drug Administration, said that these biomarkers show that smokeless tobacco users face \"adverse health effects, including cancer\". \"Our findings demonstrate the need for continuing study of the toxic constituents of smokeless tobacco as well as their health effects on the individuals who use them,\" he added. As well as e-cigarettes, other popular nicotine-replacement devices include snus, snuff and chewing tobacco. PS it's all bullshit man, the study's about smokeless tobacco products, and I strongly assume that this means snuff and snus and chewing tobacco and that ecigs don't even count. But nobody's gonna sue me and it's the kinda thing people would share. > This is a repost of my most popular post ever! From: URL_2",
"There is huge amounts of misreporting in the media of scientific results. Media outlets are interested in sensation and views - actual medical research is incredibly dense, technical and therefore boring to many people. For example, you often hear about cures for cancer. The problem is that cancers are incredibly complex with a vast variety among them. There maybe thousands of tiny molecules, each with a name and chemical formula, that researchers are studying. The 'breakthrough' may be showing that one of those compounds is elevated in x disease. What actually needs to occur for a real life change? They need to then figure out the causal relationships - I.e. Is the compound elevated as a cause of the disease? Or is it as a result of the disease? If we lower it, does the disease get better? Or is it useful as a marker of disease? If so, how can we measure it in people? Can we use a medicine to improve it? Once there's finally a possible therapy, it's tested in animals and people and that takes forever. You also often hear about the successes but not the scientific failures (there are more failures than successes). Other researchers then painstakingly research other compounds, using different methodologies, all in hope of very very slowly piecing together a coherent picture in order to achieve therapy. So basically, medical and scientific research more generally, is akin to carving away a wall with a spoon.",
"In 99% of the cases, it's bullshit. News organizations love to exaggerate scientific findings or experiments because they get a lot of views - like getting first page on Reddit. This is extremely common in \"scientific news\", not only in medicine. Preliminar studies, meant to show an idea is worth of extra funding for more conclusive tests, gets overblown as a decisive result. HIV gets killed by this drug in petri dishes? \"SCIENTISTS FIND CURE FOR AIDS!\". Pesky details that get in the way are ignored. A better treatment for one cancer was found? \"SCIENTISTS CURE CANCER\". Treatments in the very first steps of development are reported as certain and ready, when in fact most of them will be discarded while being developed or accepted for one or more of several reasons. Initial testing shows a discrete improvement in Alzheimer patients? \"CURE FOR ALZHEIMER IN THE WORKS\". Most people stop at the headline, some get to the article, almost no one goes to the paper, so it gets shared, viewed and upvoted. Just check /r/Futurology to see how effective this is. And since most of new developments in these areas fail to reach the market, these solutions simply disappear.",
"> “Briefly stated, the **Gell-Mann Amnesia** effect is as follows. You open the newspaper to an article on some subject you know well. In Murray's case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward—reversing cause and effect. I call these the \"wet streets cause rain\" stories. Paper's full of them. > In any case, you read with exasperation or amusement the multiple errors in a story, and then turn the page to national or international affairs, and read as if the rest of the newspaper was somehow more accurate about Palestine than the baloney you just read. You turn the page, and forget what you know.”",
"Most articles from a pop news site are often written by scientifically illiterate journalists, or journalists who don't know that much about the field and rewarded for reporting something that sounds exciting. This [comic]( URL_0 ) sums it up. Also, preliminary findings in animals or in vitro get touted as promising. We've cured millions of mice with various treatments that don't translate into humans. Last there is a publication bias, meaning I am more likely to publish an interesting finding. Let's say 100 people flip a coin 10 times. One guy gets heads all ten times. It was chance, but he doesn't know that, since he doesn't know about the other people. He submits his paper showing how coin flips always end up heads, and the journal publishes this. Then later, someone else repeats the study (hopefully) and it turns out that the initial finding was random chance.",
"My girlfriend does pharmaceutical development, she takes things like this and tries to convert it to a tablet or however else you are supposed to use it. It is a super complicated process to do this, and at some points in development you basically take what you think is the proper way to package these drugs and place it on a shelf for a few years to see how it breaks down and how it is coated. Doesn't always work out and you have to try again and play the waiting game, which means you start over and have to wait. We have been together for almost three years and drugs that she was developing when we met are still doing the shelf waiting game.",
"I work in scientific research. My job is to take research and get investment from industry to move the science into a commercial outcome. I see a lot of ideas here that represent the 'next big thing', but is really just a very early stage idea. When I point this out to people I get downvoted to oblivion. So basically what happens on reddit is that people love the idea and pile on with the upvotes, even when the idea has little merit. So from a reader perspective, the concept looks like the greatest thing ever, but its just really just vapourware.",
"TL;DR Media talks shit. Rarely understands what they're reporting on and generally misleads the public. Most advances take years to decades to go from concept to in production.",
"Survival rates for a lot of diseases are up compared with 10 years ago. We have super-computers that fit in our pockets. We have cars that drive themselves and run on batteries. The future doesn't arrives in big jumps, but it arrives on non-impressive small steps. It is so slow that you get used to most incredible and amazing technologies without realizing it. Medicine is not different from the rest. Keep investing in education and research, wait for it. :D",
"They don't happen in the first place. In the vast majority of cases those headlines are massively overstated. A new anti-cancer drug gets the go-ahead for a small round of human trials and /r/science reports it as 'NEW CANCER-MELTING WONDER-DRUG APPROVED FOR HUMAN USE'. SpaceX announces a new booster rocket design and /r/space cries that 'ELON MUSK IS TAKING US TO MARS THIS YEAR IN A LUXURIOUS USS-ENTERPRISE-LIKE SPACECRAFT'. The new version of Android has slightly fewer bugs and security flaws than the previous one and /r/technology decides that 'NEW SMARTPHONE SOFTWARE ELIMINIATES YOUR NEED TO EAT SLEEP OR PEE'. If you actually read the articles, you would realise that this is nearly always the case.",
"Same as all the global warming articles about how there will be no more ice by 2015, the world is doomed, global warming is \"even worse than we first thought\" repeated each week. Fake news to make scientists money",
"From what I've learned it is often a 3 step process. Invention = making a new discovery or creating a new product. For example, someone creates a flat glass touchscreen. Innovation = taking an existing product or invention and making improvements to make it more user friendly or applying the invention to an actual problem. Example, I found a way to put the glass touch screen on a phone. Entrepreneurship = Creating a business that meet a demand by selling a product in a profitable way. Example, you start selling the first iPhone. These steps can all be done by the same company or individual, or sometimes each is a separate entity. You could invent something incredible, but it is lacking in usability, or maybe this inventor even has an innovative product which meets a need, but lacks the business acumen to turn it into marketable product.",
"Because either there were scam artists or there was a fundamental issue exposed on the path to commercialisation. You have ideas, theory and lab results on one hand, and real world practicality and profitability on the other.",
"u/toastshop posted this about a year ago in a very similar eli5 thread. I think it's something every person in the world needs to read at least once. When I was a 'journo' I'd use sources like URL_0 to find nice stories that I could rewrite so they were unique and then promote them on social media sites. Eurekalert is already Buzzfeedy in its headlines, and you can tell when you read a little deeper into the article that the research was not as groundbreaking as the headline makes it appear. It might be a mouse model, it might be just a survey of 2000 people, it might be a study involving 20 people. Then when I wrote it up, I would purposefully try to avoid anything that highlighted how meaningless the study was, and I'd try to write something even more Buzzfeedy than the actual article. AIDS cure 'around the corner', 'Study: AIDS can be cured by bananas'. If I put some of the headline in 'snatch quotes', i.e. apostrophes, or put a colon indicating that someone had said something, i.e. 'Cameron: Fuck Daesh', then I would have covered my ass from misrepresenting the topic, provided I didn't totally misrepresent it. And I was churning out 5,000 words a day, often researching and spinning a 200-word article in 20 minutes. I would honestly just skimread the original source, I'd only actually read it to fully understand it if I was personally interested in the research. Furthermore, my understanding of complicated science is nowhere near good enough to be able to criticise a scientific study, all I'd do is 'spin' it. Churnalism, it's called. Shockingly, one of my skills is being able to push things to the top of Google search results. Quite often, when writing something more meaty, my research would be reading whatever was at the top of Google search results, which I know full well is written by someone who's just as big a moron as me and who's just as pressed for time as me. tldr, the internet is a tapestry of bullshit.",
"Just remember that when they announce a discovery, they then have to be approved for and perform human trials which may take 5-20 years. Also, the $10 \"EPI\" pen was just released.",
"With more promising breakthroughs, what happens at times is a problem is discovered in the next step or 2 and it's then halted and sweapt under the rug, or back to the drawing board. Then we hear about it again.",
"I do product development and formerly have been a scientist and entrepreneur. Let me sum up. Media typically overstates scientific discoveries. This is because science is nuanced but media usually isn't, since most stuff is written for a 7th grade reading level or below. Media has to sell ads to survive so they keep it accessible. A discovery in the lab is one part of building a product you can sell, but there's a lot more to it. Many things can go wrong in between a discovery and trying to create a successful product and business to support it.",
"Testing. When they say they have found a cure for cancer they mean in a select few test subjects under certain lab conditions. Doing the real tests to make sure its safe for everybody can take years and may or may not be successful. As for the $5 epipen you can take a look at projects on kickstarter that have failed. There are people who've made really cool stuff for a reasonable price but, when they suddenly have 100,000 pre orders they find that to actually fulfil that many orders costs a lot more than they originally asked for. So whilst this kid created an epipen for $5, to actually produce it on an industrial scale could push the price up a lot further. That being said there is a $10 epipen available now.",
"It's simply sensational news, Reddit's forte. The same trend can be seen in politics - every word out of a loved politicians mouth is praised and every word out of a hated politician is twisted and exaggerated. The same thing can be seen with terrorists who kill < 20 Americans worldwide a year. You'd think 50 people were dying over here a day as much as it's talked about. Spend 1/1000th of the effort that we spend on terrorism on something like cigarettes, obesity, opioid and save more lives. So it's not about lives... wtf is it about? It's about the media and about $. CNN and Reddit and every other news organization is rewarded with views (ad revenue) for every sensational story that's run. It's the same reason a \"cure for cancer\" shoots to the top of Reddit even though some of them can be considered \"fake news\". The scary party is I'm not sure if there's a solution unless it comes from within society.. which ain't happening.",
"For the examples you gave, there are brutal regulatory hurdles. Governments don't want people selling \"a cure for cancer\" without evidence that the treatment actually cures cancer. To demonstrate that you need to conduct pretty extensive clinical trials - which themselves are highly regulated. That's because governments don't want people to administer drugs where the effects and side effects aren't known - except in tightly controlled circumstances. This process can take many many years. In addition to this, the path to commercialization isn't easy - and that holds true for almost every invention. Going from \"proof of concept\" to prototype is generally all hand crafted one-offs. The commercial model needs to be developed such that it can be produced in mass quantities, and preferably at low cost. Figuring this part out is hard, expensive and high risk - and usually the people who are great at inventing or discovering stuff aren't great at scaling up, supply chain, and logistics. It requires distinctly different skill sets and attitudes. This part of the product development cycle is sometimes referred to as \"The Valley of Death\" because so many inventions and discoveries do not make it past this point.",
"I worked in a University laboratory for 3 years. We were funded by NIH. We had defined goals that we would meet in x amount of time. On our way to meeting our defined goals we produced \"new\" techniques and information, yet to be seen in our lifetime. If journalists or people that were generally interested in our research, understood (scientifically), what we were doing they can write about and extrapolate on our findings. Often, scientist (legit scientist, not some Boflex commercial people) ONLY publish their results in research journals, accredited/validated sources of information. Not to say journalists or PROMISING stories are false but it is people, with a science background, making claims that are possible but unjustified. Its like stem cell research, is it legit, WELL DUH, but depending what protein or genetic aspect you are studying. Scientists dedicate their lives to studying one protein or one organism and define as much as they can about it. It is easy to say something can or will do this, but in reality it is an extrapolation of possibility. Basically, you can and will read an article that says \"Cancer has been cured\" but this is not in Nature the science journal. It is someone with a science background jumping to inconclusive conclusions. Articles that state miracles extrapolate, and make the grunt of science look great. While beneficial to fund and continue research they are not accurate nor truthful.",
"Speaking of the Epipen, pharmaceutical prices in the US are basically arbitrary in regards to pricing a specific product. There's no reason an Epipen should cost $600, and widgetpill costs $6, They could just as well be reversed. Someone in a suit just entered numbers in a computer and decided that's what the price would be. The reason for that is so much of the cost of drugs has no relation to the actual drug. You can sell the drug for slightly more than the cost of production in Togo, but you need to make up the costs somehow. And that burden falls to consumers in the US because our insurance company can pay for it (and if there's no insurance there's normally discount programs so we pay something more like someone in Togo. Not a lot of uninsured people are paying cash at the point of sale full price for Epipens, those that are our obviously squawking about it so we hear about it.) So why do drugs cost so much?, yes, unlike most hospitals and some insurance companies pharmaceutical companies are for-profit, but developing a drug is unfathomably expensive ($2.5 Billion), and America is so litigious that ads seeking to sue pharmaceutical companies are a television staple. So what about the $5 epipen. It's easy to 3D print something and say you can manufacture it for \"X\". But to get it approved for sale, buy insurance for when you get sued by someone saying it made her ears turn purple, it's probably going to be well north of $100. Still cheaper than the alternative, but no bank is going to upfront money to pay for studies and tooling when the Epipen makers could just lower their price to $95 in response to competition on that product (and raise price of widgetpill to $600 to compensate).",
"As a scientist, I cannot tell you how maddening it is to read (most of) those articles. News articles like that are almost always written by people with no formal education on the topic they speak of, and I dare say little informal training. They sensationalize findings, because they are more concerned with how many people read their story than how well they are representing the actual facts. Usually the researchers themselves include a discussion that puts their findings into context, but you have to read more than simply the abstract to get to that. News reporters misrepresent the relevance/strength of findings to the point of fiction. I've seen it countless times. Or worse - they report on things as \"scientific breakthroughs\" that haven't even been vetted by peer review. I saw an excerpt on the news recently about a professor who was able to power his house with a glass of water thanks to a new highly efficient device that creates energy using water as fuel - something that can be done but not anywhere close to the remarkable efficiency of his. They waited until the very end of the segment to mention that the professor is holding off on submitting his findings for peer review until he gets a \"worldwide patent.\" The same can be said for that Italian neurosurgeon who was supposedly doing head transplants. A single study only carries as much weight as the strength of its methods, especially regarding the sample size. Findings must be taken into context of the larger body of research already existing. It is not particularly uncommon for a small study to conflict with the actual truth - and by \"truth\" I'm referring to the collective pool of data from all well-run studies on the topic. This is because of statistics, and something called confidence intervals which I won't get into here but if you're interested I'll expand upon. Yet, very rarely do organizations such as the American Heart Association, who compile multiple studies and come out with only strongly supported findings, report anything that is (to a general audience) striking or newsworthy. You don't see the Cochrane Library upturning well-established facts with new and sensational studies every week. Because that's just not how science really works, with very few exceptions."
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5t5j6k | How does a turning a faucet change the temperature of water | Repost | explainlikeimfive | {
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"There are two tubes running into your faucet. One straight from the mains, and the other from your water heater. When you open the faucet, the tap itself opens to allow water to flow out. When you turn the faucet, you are changing the amount of water coming through each of the pipes. All the way to the hot side opens only the hot water pipe and not the cold one. Same for the cold water side. In the middle should ideally be half and half, but since the water heater heats the water to uncomfortable temperatures, the middle generally allows more cold water so you don't burn yourself."
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5t8hbl | What happens when you download something? | How does data get from one computer to mine, and what happens if I pause/cancel it half way? | Repost | explainlikeimfive | {
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"The data is a file. There are other explanations for how the Internet works if you search. The file exists somewhere as a complete file. It can be a photograph, music, speech, a video, some program you can run, anything which is data. Your download command is a request that the file be sent to you. Sometimes these files exist in multiple locations, called mirrors. The responding computer, or server, a specialized computer for moving information, starts transmitting this file to your computer breaking the data up into little bits called packets. Each packet has your computer's address built in and enough information that your computer can reassemble the data perfectly. This includes tricks used for error checking. If packets get lost or scrambled there are routines for retransmitting them. The file was only copied. It is not destroyed at the source. Your computer receives all the packets and reassembles the file. In the file there is a description of what it is and what to do with it. If it is a photograph there are instructions as to how big it is. If it is music there is a description of how the file was coded. Your computer will process this file according to the instructions. It will show you a video, play a song, or run a program. Some of the programs are viruses which can harm your operating system."
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5ta4xl | Why do men become bald-headed more often than women? | Repost | explainlikeimfive | {
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"Testosterone, while it is responsible for secondary sex characteristics such as body hair growth and the deepening of the voice, is also toxic to hair follicles on the top of the head based on its reaction with some of their androgen receptors. Based on genetics and cell type, different parts of the body respond to testosterone differently."
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5thihs | What actually happened with the Y2K bug and exactly how was it resolved? | I was alive then but too young to recall any of it but I hear about what a big deal it was quite often. | Repost | explainlikeimfive | {
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"Okay. So a lot of early computers kept track of the date with just the last two digits. This let them save space and time programming, back when every little bit of information mattered. This meant that for many old computers, going from 99 to 00 would make it seem like everything was now in the past, that new files would be made that happened before the existing ones. This had the potential to really mess up a lot of systems. So a concentrated effort by computer programmers around the world was made to ensure that this wouldn't happen. They found old computer code that used just the last two digits and expanded them so that you wouldn't have problems when it became the year 2000. It could have been a serious problem, but we managed to pretty much keep it all under control."
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5tkz8g | why (some) Americans hate Obamacare? | Repost | explainlikeimfive | {
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"1.) It fundamentally changed the relationship between the federal government and the individual citizen. This was discussed at length during the Supreme Court hearing (by Kennedy, I believe), pointing out that the government had never claimed the power to force individuals into engaging in commerce with other private parties under penalty of law. 2.) It was a windfall for the very insurance industry that was villainized during its passage. You would be hard-pressed to think of a better way to enrich the Insurance companies while doing very little to address the underlying issues with the cost of healthcare. 3.) It is detrimental to a significant portion of young working families by either forcing them to buy insurance at a time when it is reasonable to forego it due to low risks or to buy it at higher premiums. 4.) The law was huge and complicated, but passed in a rushed, opaque manner at a time when the Democrats had a near supermajority in Congress. It really felt like they were trying to slip something by before anyone had a chance to fully analyze it, leading to a very difficult implementation. The law was rapidly written in a piecemeal fashion by multiple parties, leading to contradictory language and badly in need of a streamlined approach. 5.) It failed to remove long-standing and important barriers to insurance access such as the an on interstate purchase of insurance. This a particularly egregious example of congressional overreach based on the Commerce clause of the Constitution. Congress simultaneously bans interstate commerce on insurance and claims the right to regulate it as interstate commerce. 6.) It is the worst of all solutions. It is neither the relatively simplified and easily regulated single payer solution nor the fully competitive free market solution (I.e. removing barriers like in number 5), but with arguably some of the worst elements of both. I could g on, but I hope this at least shows that it's not all partisan vitriol spewed by puppets of the almighty Fox News clown show as some claim.",
"Middle-class hates it. For the lower class it really is helpful and useful, but if you make a normal amount of money it is expensive as FUCK to pay for",
"I could be mistaken, but I could have sworn before it came into effect, Obama promised that it wouldn't cause my current insurance costs to go up. They went up a fucking lot.",
"The government forces people to buy a certain product or be penalized, which is illegal and stupid. Obamacare made everyone's health insurance cost go up by a huge amount (my wife's increased by 400%). Also, it's immoral for someone to steal my money at gunpoint to pay for someone else's medical care."
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5tl0mb | Why is it that when we are enjoying ourselves that time seems to go by quicker? | Repost | explainlikeimfive | {
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"I think one of the main reasons is we get lost in what we are doing and don't think about the time passing, but when you're going through something you don't like you are constantly thinking about the time and looking at the clock",
"There's something called \"flow\". It's a mental state created by doing something that matches your skill level, and is enjoyable, but also slightly challenging. Flow is like when you're extremely focused on your task and the world kind of disappears.",
"A cool book just came out called \"Why Time Flies\" and what I have read of it was really cool!"
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5tlo9g | How come our TV never buffers like videos on our phone or computer does? | Repost | explainlikeimfive | {
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"text": [
"Your TV has an input source dedicated to just providing the video stream. It is never interrupted with other traffic. Internet streams are split up into small chunks called packets, which are sent through many different routing devices to get from the server to your computer. Each of those devices has a maximum speed, and if one if them gets overloaded with a spike in traffic then some of that traffic will have to wait. To try and avoid random pausing in the video your receiving device will 'buffer' a few seconds of the video. That is it has for example the next 10 seconds already downloaded and ready to play. If the download is stopped for a second it will keep playing through the 'buffered' 10 seconds, and keep downloading as it can. It will also try to download a bit faster to increase the size of the buffer. Satellite TV doesn't do this because the satellite is broadcasting a dedicated stream directly to your receiver. There are no intermediary devices, and no other traffic to get in the way."
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5tm0sd | who decided we needed different timezones? Why couldn't 1AM be the afternoon in parts of the world? | Repost | explainlikeimfive | {
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"Because that would be inconvenient, especially if you travel between time zones often enough. It would be frustrating to check the time and see that it's 1pm and think it's lunch time, only to realize that the sun is setting and you have to go to bed in order to be up for work. Noon was designated to be the time when the sun was at its highest point, so 1 pm is one hour past that time. It's been like that for thousands of years, ever since timekeeping became a thing. Consider this: Right now, if a business lies across time zones, it can still have consistent times that it's open. For example, it could be open 7am to 2pm. And this would be basically the same time of the day across the country. However, if there were no \"time zones\", then each area would have to have its own opening hours set in order to be open around the same time of day as the other locations (let's say it's a breakfast and lunch-type diner) and so you wouldn't be able to advertise \"Open at 7am every morning!\" across the country, but would have to make separate advertisements for every single area your business is in with their own hours (\"Open at 1am every morning!\"). Also consider: It's 4pm where you are. With time zones, you can check what time it is in Australia, and see that it would be an inappropriate time to call there. However, if you didn't have time zones, you would have no way of knowing unless you looked up some kind of additional chart to see what part of the day that would be.",
"Before timezones everyone set time locally. Noon was when the sun was directly overhead and all other hours were set accordingly. Timezones formed because of trains and the need to have more accurate and consistent timekeeping for the arrival and departure of the trains. The timezones were designed so that noon stayed roughly overhead at mid-day in each timezone as to not disrupt work schedules and life. The suffix pm means \"post-meridiem\" meaning after midday. The suffix am means \"ante-meridiem\" meaning before midday. AM times cannot be in the afternoon because that is \"AFTER NOON\"."
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5tmh19 | Why do we not remember the last moments before we fall asleep? | Repost | explainlikeimfive | {
"a_id": [
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"text": [
"One aspect is that the information isn't that important and you're not receiving much information into the brain, so what is there to remember? It's also important to realise that 'sleep' and 'wakefulness' are really just two points on an entire spectrum of consciousness. It isn't like you instantly go from being awake to being asleep; your brain slowly begins to inhibit lots of different parts of itself and the body. Your muscles become more paralysed, incoming information is filtered out, and eventually many of your brain processes (including memory) are inhibited."
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5tmzwk | Why is it so hard to produce a good consumer printer? | I understand, that requirements for printers are vastly different in the enterprise, small business and private sector. But it can't be that hard to produce and easy to maintain and reliable device, can it? Most of the time when I print at home either the colors are off because one of the cartridges gives up or my OS takes ages to get a connection to the printer. So: Why is it so hard to produce a good consumer printer? | Repost | explainlikeimfive | {
"a_id": [
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"It's not. It's hard to produce a great quality consumer printer _at a price that people are willing to pay_. Long ago printer manufacturers discovered that they could make more money by offering dirt cheap printers (I saw one on sale recently for $10!) and charging exorbitant prices for the ink. I'm sure there's some consumer psychology at work here, i.e. people will want to pay less up front even if it means they pay more over time for the supporting consumables (ink) than pay a lot up front in exchange for cheaper consumables down the road. There's some sense to that since the consumables are a less predictable cost."
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5toche | What happens when you are driving from a country that drives on the left side to a country that drives on the right side? | i.e. Thailand to Cambodia or vice versa. | Repost | explainlikeimfive | {
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"They make you stop at the border and cross sides, and lots of warning signs remind you about it. [example]( URL_0 ) In a *very few* cases, a special cross-over ramp is built so you can change sides without stopping, but that's expensive. [example]( URL_1 )"
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5tq0p7 | Why does your chest actually hurt during emotional distress? | Repost | explainlikeimfive | {
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"text": [
"One line of thinking postulates that there are two components to physical pain - affective and sensory. The affective component is strongly associated with a part of the brain called the dorsal anterior cingulate cortex (dACC; note there is no exact 1:1 mapping, just a strong correlation). It has been found that the dACC is also highly active during emotionally, but NOT physically painful events, such as financial hardship. The idea is that, because pain is such a useful tool to have in terms of adaptive fitness, the dACC has been \"coopted\" to activate during purely emotionally painful events, and the feeling is subjectively similar. See a paper called \"Broken hearts and broken bones: a neural perspective on the similarities between social and physical pain\" (Eisenberger, 2012) for a more complete overview."
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5tq1le | Why is it that, when you are congested, one nostril is a mucky swamp and one is dry as a bone but then they pull at fast one on you and switch?? | Repost | explainlikeimfive | {
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"You don't notice it when you're not sick, but your nostril actually do this all the time. It's just exaggerated when you're sick. It's called the nasal cycle. At any given time, one of your nostrils is doing most of the work and is clear, while the other one is \"resting\" and is more congested. It's managed by your autonomic nervous system so you can't control it and most of the time don't notice it. There are two reasons for this. The first is that it gives the cilia and mucous membranes a chance to rest so they can better filter and humidify when they're doing the work. The second is that it helps you smell better. Some smells are better detected in fast-moving air, and some are better detected in slow moving air.",
"Most people have a so called \"nasal cycle\" where the amount of air going through each nostril fluctuates. At any given time even without a cold if you put your hand under your nose, you may be able to feel that more air is coming out of one side than the other. This helps us smell better by giving each nostril a break once in a while. So when you are congested the nasal cycle continues and the side that is getting more air flow will be less stuffed up than the side that is taking a break.",
"What happens if you don't have a nasal cycle? I had multiple sinus surgeries as a child by a not so great ENT (literally cauterized my sinuses with too little local anesthetic) and I don't experience this. If I'm lying down, congestion will switch sides if I change position, but only then. I also have a terrible sense of smell.",
"Not sure about the congested part (because personal experience is different), but generally one of your nostrils is always (partly) blocked while the other does the breathing, and they switch periodically. One hypothesis is that this forces a human to change sides when sleeping, [which prevents stalling of circulation in the body parts under pressure]( URL_0 ). Source: Wikipedia.",
"There's a very good episode of SciShow that discusses exactly this topic: URL_0",
"I believe all the other commentors are correct, but let me say that it feels amazing being able to breath through two nostrils for a minute or two when you're *that* sick.",
"I like when it makes a small click sound and suddenly that nostril is open to breath freely. I've noticed this since I was a little kid.",
"After having a ER room visit (temp spiked at 104.8) level of the flu for the past 7 days, I was also wondering this as I rarely get sick and never dealt with a stuffy nose that randomly selected the side it was going to piss me off with before. Thanks OP for asking, this honestly helped.",
"Why does it flip when i change sides in bed? Also what does nasal spray do?",
"This is why I love ELI5. It answers questions I think about when I'm sick but forget about the rest of the time."
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5tqah0 | What do people on Wall street actually do? | Repost | explainlikeimfive | {
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"Let's say you want to make widgets, but you need money. You could ask out investors, but if every inventor had to talk to every investor it would be time consuming. So investors give their money to fund managers and the fund managers distribute the money to inventors (taking a cut off the profits from investments or charging or fees). Everything else is just increasingly more complicated ways of trading risk for money. It's not much different than a grocery store. If every person that needed did had to contact and trade with every farmer it'd be insane. The grocer doesn't make anything, but they take a cut for facilitating a trade (essentially).",
"on a very simple level - they move around money. and they move this money between things which are all the time changing in value. so if $100 is moved over into the form of a share in a company, the next day (or the next minute..) that money could now be worth something else. given the size of wall st, we are talking about the movement of hundreds of millions of dollars. and when an investment goes badly and $100 million becomes $50 million, or vice versa, and when this happens all the time with BILLIONS of dollars - it effects the economy. So what purpose does it serve society..? Not too much really... but what effect does it have? HUGE Edit: i have received some flack for my last line saying Wall St does not do much to serve society. What I meant by this is to be neutral - Wall St certainly has its benefits, but was also the cause of the global financial crisis in 2008. But I think its effects are more interesting to discuss then what purpose it serves society. Edit 2: I am receiving more and more aggressive messages about how wrong my post is, followed by long complicated answers which simply expand on exactly what I said - Wall St moves money around. And by moving it around, it causes ripple effects across the economy. I apologise for not being able to explain the ins and outs of Wall st in less than 100 words - shout out to SteelGun for his great response below Edit 3 (and final edit): HOLY CRAP REDDIT YOU'RE SO MEAN. While I am getting abused to death I still have not had ANYONE disagree with my fundamental explanation of what the people on Wall St actually do. I have however mislead people into believing that Wall St serves no purpose to society - I accept that this was written extremely poorly, and not meant to come out that way. Never have I even thought that Wall St is just a thing that's there that serves no purpose.. and you shouldn't either. I wanted to edit the post when it was on like 20 likes but only bad redditors remove things they said that people didn't agree with, so I'll leave it but yes that last line was fucking dumb. HOWEVER I have also received messages from many people backing me up and saying my answer was pretty well written for such a massive question in ELI5 terms. If you are new to this thread please read many of the long well written posts below for *other* good answers too. peace fucking lol i got gilded",
"It's difficult for some people who work for a company that creates a tangible product to understand, but these financial institutes are almost always vital to a business' health at one time or another.",
"When movies refer to \"Wall Street\" professions, they often refer to investment banking (like Patrick Bateman in American Psycho). In real life, Investment banks often provide transaction services and advice to companies. Their \"clients\" are companies that are looking to either buy other companies, sell their company to another company, or merge their company with another one in order to increase enterprise value (this can be referred to as M & A Advisory or just simply an investment bank). Other lesser known \"Wall Street\" jobs are in Private Equity. A private equity firm essentially raises capital from outside investors with a lot of money (high net worth individuals, family offices, pension funds, sovereign wealth funds, insurance companies) and combines that money into a \"fund\". Private equity firms leverage those funds to own stakes in other companies, infrastructure, and more in hopes of providing returns to those investors. Others, Hedge Funds, are similar to private equity firms in that they can raise and leverage massive amounts of outside capital, but hedge funds are able to invest in conventional securities like stocks, bonds, etc as well as non-conventional ones that are difficult for the \"average joe\" to understand like distressed real estate debt. Essentially, these employees are researching, analyzing, and executing and combining many strategies including buying, selling, shorting to \"hedge\" investments and seek the highest returns for themselves and their investors. Hope this helps. Source: work in finance Edit: Stakes.. not steaks - was probably hungry when I wrote this comment",
"#**First lets define wall street** If by \"wall street\", you mean the general financial institutions and markets around the world including in the United States, then this is a *very* broad question. With that being said, I will give it my best shot. - ---------------------- We have three basic divisions of the financial industry. This theory on the financial industry I learned when getting both of my undergrads is not all encompassing, and obviously one could come up with other divisions that would equally describe the market. Neither description would be wrong and this will suffice. #**Financial institutions** These are (generally) the regulatory agencies that intervene in the market for various purposes. Examples include the SEC, the Federal reserve and so on. These (mostly) government institutions help regulate the market, provide various services (like issuing money), and pursue legal action against criminals. *example* The federal reserve may raise interest rates to stop or curtail inflation or it may increase reserve requirements for banks for a variety of reasons. ---------- #**Financial markets** These are the physical and virtual (ie: internet) meeting places where the various parties meet up to conduct business. In the same way you and I have a market to pick up our groceries or buy a car, markets in the financial industry are set up to reduce the cost of doing business and to allow for interested parties to conduct said business. *Example* A farmer wants to sell an options contract on the bushels of wheat he is growing for harvest. In order to meet with potential buyers, this farmer sells options contracts for a specified price on the Options market. He may do this at the Chicago Mercantile exchange, which was famous for exactly this kind of transaction. Without the Chicago Mercantile exchange it would be nearly impossible for prospective sellers and buyers of the options contracts to meet and conduct business. Another example may include a company looking to raise revenue for planned business expansion by listing shares in the company on a market (through a broker, which we will discuss below). Without being able to have buyers and sellers meet, this task is made nearly impossible, and the benefits to this transaction would not occur, namely the business would be much less likely to expand and at the same amount, and investors would have less avenues for wealth creation. ------------ #**Financial Brokers** This is a lot easier to explain. The brokers are the various clearing house associations and stock market intermediaries that facilitate these market transactions. To use the brief example I gave above about going to the store to buy groceries, if grocery stores *as a whole* are the market, then the Shop and Save company would be a broker in this analogy. ------------------- Now that we have a Very^very^very basic understanding of the background information needed to understand the financial industry, lets start answering your questions. Keep in mind, I answer these as someone with two 4 year degrees, one in Business, and the other in Economics, both with a focus on finance. > Do create anything? Simply, yes. Types of services offered include, but are not limited to the following: * Trading risk from risk averse to risk takers, like in our options contract example above * Allowing groups of people, like corporations, to raise funds, including but not limited to debt and equity issuance * Investment banks provide a wide array of services like business appraisal, Mergers and Acquisitions, and identifying market trends. * engineering complex financial instruments (usually a type of derivative) to meet some kind of goal EG: collateralized debt obligations Etc From an economic standpoint, one might distill it down to simply this saying, That the financial industry allows \"Net-Savers\" (used broadly) to lend funds to \"Net-spenders\" for a return, who then generally use the funds for some end. These transaction *generally* only occur when both parties benefit more than they lose out, and everyone is left better off. > Are they just playing with everybody's money No serious person who has studied the financial industry believes this. There are *real* socially beneficial services provided by this industry. Furthermore competition in finance is intense, and those companies and individuals that are not serious about providing value for stakeholders are ushered out or lose money quite fast. > I really have no idea Fear not, most people have no clue. In a similar fashion to medicine, or physics, Finance is a highly specialized field with professionals that often need bachelors degree or higher to break into entry level positions. There is industry specific jargon, lots of math (which the general population has issues with), and abstract concepts that take awhile to truly understand on the second level. It took me about a year of undergrad finance courses to really *truly* understand what the heck is going on in finance. I hope that helps, and if you have any questions, feel free to ask, and if I have the knowledge, I will answer to the best of my abilities.",
"There's a big variety of roles in Finance. At a high level, financial institutions essentially facilitate the growth of literally every other industry there is by finding someone with money to invest in someone with a plan/project. Think small business going to a bank for a loan, but it gets scaled up and more complex with huge companies. In more detail, you have the \"sell-side\" and the \"buy-side.\" The sell-side is what you think of as Investment Banks. These are the companies like Morgan Stanley, Citi, JP Morgan, Goldman, etc. that work with institutional clients. This mainly happens through advisory and trading functions: - Advisory is what is \"Investment Banking,\" think analysts grinding away for 100 hours a week. Let's say a client retail company comes to a bank and wants to raise money/acquire a company/get sold. Let's say raise money for now, and they want to do that by selling equity (i.e. ownership stakes). First, the industry coverage group for retail learns everything about the company, and uses their expertise in this industry to put a value on the company. Once they do a lot of that, they hand it off to a market facing product group called Equity Capital Markets (the product meaning equity). This group sees what the market will accept and finishes pricing and marketing these new shares in the company. Let's say selling these shares raises $100 million. The advisory group earns a fee for doing this, as a percentage of the amount raised. - Sales and Trading. This is what you'd see in Wolf of Wall Street. Trading teams are called \"market makers.\" Someone wants to buy a stock/bond, someone wants to sell, they're in the middle. They buy the security from the seller and sell it to the buyer and a SLIGHTLY higher price and make a spread. They are out of the door at 5 PM and don't work weekends. Clients are large asset management funds (see below) and hedge funds and shit. The buy-side is actual investing. You have things like: - Mutual funds: Pretty standard funds of stocks and bonds and shit - Large asset managers: Think Blackrock. Has many mutual funds and other strategies - Alternatives: Real estate investors, private equity investors (buy a whole company, grow it for a few years, sell it for profit), and hedge funds (similar to Sales and Trading but they're the ones actually buying and selling stocks/bonds)",
"Most people haven't touched upon that they help companies raise money by either issuing stock or bonds. Basically a company sometimes needs a lot of money at once to do a project or release out a new product, but they don't have that money. So in order to get that money they go to Wall Street and say \"hey I need a billion dollars to launch my new idea\". For bonds, Wall Street banks get together and say okay we have found 5 banks interested in giving you that money as long as you pay us back in 20 years and 5 percent interest. They give the company the money and the company pays them back over time. For stock it's similar but they are basically helping a company issue shares of stock for the public to invest in the company for a fix price in which the company gets the money while the investing public get potential future return from the stock in either dividends or stock appreciation. The incentive for banks to help the company issue the stock is that they get to be some of the first people who buy it.",
"Hi, 15 years in an investment bank here, and I'm slightly disappointed with the top answers I'm reading, so here is my version. \"Wall Street\" is a pretty broad term and most of the big firms do a lot of things, however I'll broadly split them up as follows: **1) Corporate Banking / Advisory** **What is it?** Providing advice, lending, and all kinds of services to big companies, ranging from multi-billion dollar merger/acquisition to day-to-day payment processing **Who benefits?** This one is easy... the big companies benefit, or they wouldn't pay the fees. Every big multinational operating in different countries relies on the services the big banks provide. **Why do they get paid so much?** At the top end, the biggest transactions (e.g. the $85 billion merger between AT & T / Time Warner last year) are worth so much that the advisor's fee is like an afterthought. If you believe some good advice will get even 0.5% difference on the price paid, that's still almost half a billion dollars. Which makes a $50 million fee look like great value. **2) Sales & trading / intermediary services** **What is it?** This is probably the most complex to explain. Broadly it is buying and selling shares and other securities on behalf of other people, either private individuals or professional investors. That includes offering advice to and making purcheses on behalf of buyers (Broking), as well as advising issuers, creating derivatives, and marketing financial products on behalf of sellers (Sales). Finally there are pure intermediary services where a firm acts as \"market maker\" in other words offers to act as buyer or seller for anyone in the market to speed up the operation and avoid having to individually pair up every buyer/seller who wants to exchange their shares/securities. The market maker gets paid from the small difference (\"spread\") between buy price and the sell price. **Who benefits?** As before, many services have a direct fee that the client pays - so it is the client who benefits. In many cases the client is another bank or a professional investor. Ultimately, any company that relies on the markets for funding, or any individual who has investments or pensions, will benefit from markets operating efficiently. **Why do they get paid so much?** In a word, volume. Not many companies can provide these complex services, and the amount of money that goes through big banks' trading floors is immense, so even small percentages or spreads add up quickly. It's not just traders on phones buying and selling, there are large numbers of mathematicians, lawyers, IT people, researchers and so on making sure the services are efficient, legal, and the advice is the best available. **3) Professional Investors** **What is it?** Operating funds and making investments. This is often what people think about when the term \"casino banking\" comes up. Fund managers operate funds with other peoples money, such as pension and investment funds. Proprietary traders use a bank's own money, but they often have to try and manage the bank's own risk to ensure it has a stable overall risk profile and is less likely to fail if there is a big shock or crash. Hedge funds use a combination of their own money and other (generally large) investors to borrow money and invest it, with higher risk but higher chances for rewards too. **Who benefits?** The investors, clearly, if the fund is successful. Everyone's savings and investments are likely managed by one of these fund managers and we all rely on them doing a good job for our own prosperity and retirement prospects. **Why do they get paid so much?** They manage large amounts of money and when they get it right, they make huge sums for their investors. The rewards follow the performance of the fund and it's a cut-throat world if you fail. Overall, the answer to the question of \"who benefits\" comes down to \"money makes the world go round\". There are people with money to invest (savers, pension funds, big companies with cash reserves) and many people who want access to that money (startups, governments, major corporations wanting to invest, individual borrowers). Banks help put two and two together, in all the hugely complicated ways that a modern economy operates. Everyone who needs money, who wants to borrow or invest or even just store and move money benefits from the banks doing their job properly, in all the different ways I outlined above.",
"You're going to get a lot of bias on this one, my own included. Like most jobs, there is a purpose and it can be mishandled and cause significant harm. The purpose at a high level is to create \"liquidity\". Matching good ideas/companies with money so that they can grow faster. May work best with an example. Imagine an extreme with no banks. I own a business that makes the best tacos in the world. But opening a taco stand costs a lot of money. I could work hard at other jobs, or sell tacos out of my house for a while to make the money to open my shop, but that takes a long time. Investors/loans allow me to skip the step if I can convince people my tacos are indeed the best. At a larger scale, a proven restaurant can grow much faster if they don't have to rely solely on the profits of the first restaurant to build new ones. On the other side of the bias, current wall street instruments include \"derivatives\" which basically allow someone to make more complex investments with more specific \"win\" conditions. It is arguable whether these instruments actually provide additional liquidity. Their complexity means it is easy to have unintended consequences that screw everyone over - hence the bad rap.",
"Former finance bro here. The top answer is complete nonsense. Asking what is Wall St and what does it do is similar to asking what is a scientist and what does a scientist do? There are many types of scientists, and likewise, there are many posititions throughout \"Wall St\" that serve a variety of value added functions. One of the most important aspects of capitalism, at least in my country, the United States, is our free enterprise system that has taken shape in the form of the various stock exchanges - NYSE (New York Stock Exchange), NASDAQ, etc. Essentially when you see the ticker on CNBC for each respective company and a price next to it, that is the share value for a stock that means nothing except the price it costs you to buy one share of stock. A share is an ownership stake in the company being discussed. For example AAPL, is Apple which trades on the NASDAQ stock exchange and is currently valued at $132 a share. When people talk about the \"market cap\" or market capitalization, that's the value of all the outstanding shares at $132 times the total number of shares issued. This gives you the idea of the complete valuation of a company. This number is based on all cash flows and takes into consideration assets and liabilities to give you an accessible idea on the value for even the most unsophisticated investors, or workers or anyone to participate in our capitalist system. It's seriously accessible to anyone. You can buy stock for $8 a trade on some websites nowadays. So one of the most important functions of \"Wall St\" is to help companies in the process of issuing stock. When Steve Jobs and friends built Apple, they created a company and sold computers. Their individual wealth was tied into the cash flows from their ability to sell computers at a profit. In order to grow into the massive company they are today that has created technology that most of us use daily, they issued stock, which sold off shares of their company in exchange for capital. This capital is used to rapidly grow companies, and is one of the most beautiful aspects of our capitalist system. That is why any entrepreneur with a dream, creates a business, employs people, does their best to sell the best product---with the dream of eventually seeing their company they created out of their blood, sweat, and tears up on one of those stock tickers on the various exchanges. These Wall Street firms help companies grow and raise capital. That is but one function. I myself used to be a commodities trader, I worked in oil in hedging fuel prices for a major air line. We ensured stability in fuel prices which represented almost 35% of the cost structure of the company I worked for.",
"Short basic explanation of how stocks work, which is a lot of what goes on at Wall Street: Imagine you have a company you own. You think your company could earn more money if you had some more cash, but you also don't want to go to the bank for a loan. Instead you cut up ownership of the company into pieces (shares) and you sell them to people interested. People will want to own a piece of your company because you say that every now and then, you will give them some a piece of the profits you earn (dividends). So theoretically, if they buy a share from you now when it is cheap, then later when you're making lots of money, they will get their money back over time with the dividends. If your shares can be bought by anyone, then they are publicly traded. If someone is buying stocks, they probably buy lots of different ones so that if one company fails, other companies will keep going and they won't lose too much. Keeping track of all this can be a full time job, so people hire other people (brokers, fund managers, etc.) to deal with this for them. Wall Street is where many of these brokers and fund managers work. Because they tend to be in contact with each other (this was more common in the past but works a little differently with the internet and high-frequency computer trading) this can cause ripples in the economy for investors. For example if one broker lets it slip to many others that, say, Samsung might be releasing a new device that will make them a lot of money (resulting in high profits, and thus high dividends) many brokers will encourage their clients to buy Samsung shares so that the brokers can get some of that money. Then if it turns out that Samsung aren't releasing anything new and actually accidentally made a lot of phones explode, people don't want that stock any more and will want to sell it to someone else quickly so they can use their money to buy something more profitable.",
"I feel that these comments are leaving something out. Are there scumbags and parasites on wall street? Of course. But wall street also provides legitimate services. Companies need capital (money) to grow. Wall street provides that money. The main ways companies raise money are by going public (stock) or selling bonds (debt). Venture capital can only get you so far. Amazon, Apple, Home Depot, Google are all publicly traded companies and wouldn't be as big as they are or might not even exist, if they didn't go public. An investment bank helps you go public or sell bonds. These companies need money, but have no idea how to go public (or sell bonds). They go to an investment bank and the investment bank makes it happen. Wall street isn't all hookers and blow like wolf of wall street. There are a lot of really smart guys (nerds) working long hours in front of computers. These guys make good money but nothing to brag about, especially in NYC. Most of these guys can't even afford to live in the city and are laid off every time there is a downturn.",
"So imagine there's a cake. And when someone slices off a piece of that cake, Wall street takes that piece of cake and hands it to someone else. In that process, a small crumb falls off the piece and Wall Street people take that for themselves. Soon enough they will have their own cake made up of parts of other people's cake. Then they can sell their own cake to others. They can also slice up and package their own freakish cake as something \"special\" like the daily special at a restaurant. (LPT: don't ever order the seafood special at a restaurant and if anyone in Finance tries to sell you something special, run) They also do other weird things with the cake and crumbs. Like letting people bet on whether the crumb lands on the floor, or the table. Or other things like having other people buy a piece of small cake today and promise them a bigger piece tomorrow.",
"Oooh I can finally answer a question! A lot of the answers here are riddled with misinformation. The answer to your question is people on Wall Street do a ton of different things. Investment Banking: this department is essentially corporate finance advisory. There are a few different areas of IB, the most well known area of ibanking is mergers and acquisitions, investment bankers advise companies on buying and merging with other companies. When you hear about Facebook buying WhatsApp, or mega mergers, investment banks were behind the scenes trying to help the deal go through. There are also other areas of banking like restructuring, equity capital markets (releasing stock to raise capital), debt capital markets (issuing bonds and debt to raise capital). Research/Sales/Trading: this is the part of investment banks that buy, sell, trade, and release research reports. They trade investor money and try to make money essentially any way they can. Some people trade derivatives, others mortgage backed securities, and many other products. Then there are other areas of finance like asset management which can range from helping people manage personal savings to helping manage pension funds etc. Do they create things? Kind of. Wall Street enables a hundred different industries by providing debt and helping to raise capital. The asset management side of things help ensure that pension funds don't run insolvent to ensure that senior citizens have cash that they have rightly earned over their careers. Obviously, there have been many unethical actions taken by financial institutions over the years, but historically have created far more wealth and value than they have destroyed. It is incredibly difficult to get hired. The majority of front office functions of banks (functions that are revenue generating) are held by Ivy League graduates with top gpas. Many front office positions require a ton of hours and are incredibly high stress. Source: have worked a variety of different positions at a variety of banks.",
"Wall Street does a ton of things and it's huge. Trying to say all of what wall street does in this answer is not possible. Instead, I'll talk about two big things that wall street does. 1) Wall Street moves money from people who have it to people who need it. 2) Wall Street moves risk from people who have it to people who want it As for 1) when a company issues stock or bonds, they're doing that because they want to raise money. They want to invest that money in the business (hopefully) to hire more people or build more factories or w/e. These companies go to Wall Street (Let's say they go to our friends at Goldman sachs) and Wall Street will hook them up with the investors (hedge funds, pension funds, other asset managers, whatever). These investors are looking for a place to put their money and hopefully generate more money. Goldman Sachs will then facilitate the linking process between these two groups. This is just one example of how Wall Street moves money from the people who have it to the people who need it. Another example might be when you invest your money by giving it to Vanguard. You have surplus money right now, and you feel that in the future, you will need more money (you'll be retired or w/e.). Vanguard will then take that money and invest it so that in the future it'll be the same (or hopefully more) amount of money. There are a ton of other examples of how Wall Street moves money from the people who have it to the people who need it. 2) Risk - Let's say you're McDonalds. You make burgers that ppl like to buy. But, as a part of your business model, you want to charge a constant price for these burgers. You want to always charge $5 for a big mac. But, the price of wheat/beef/lettuce/whatever ISN'T constant. If there's some disease that kills a bunch of cows, then the price of beef will go up. How do you, as McDonalds, still provide a constant price to your customers? Well, you'll go over to your friends on Wall Street, and try to arrange a deal, where you can acquire beef/lettuce/whatever at a price that you set now. In that sense, you can eliminate the risk of the price going up and you can charge your customers a constant price for your products. On the other side, let's say you're an expert on lettuce farming techniques, and you're sure that the price of lettuce is about to crash. You have info on a new GMO that will make lettuce a lot easier to produce. To exploit this knowledge, you'll take on the risk that McDonalds previously had by selling them lettuce at a set price for future delivery. If all goes well, the price of lettuce will go down and you will be able to buy lettuce for cheap, and then give it to McDonalds at the higher price you set today. Wall Street facilitates these transactions. This is a small example of how Wall Street can help transfer risk from people who don't want risk to speculators. This is a pretty short summary of what Wall Street does. There are a ton of other services that Wall Street provides to the public. If someone says Wall Street doesn't do anything important, then they really don't know what Wall Street does. Wall Street provides an essential service to the public. But yeah, obviously they do get greedy and stupid sometimes.",
"Whatever everyone else says, there's at least a couple of guys on wall street who sell falafel. I've met them.",
"The service provided by the stock market is resource allocation. By buying and selling, they find the market value of things. It allows successful companies to raise capital. Wall St firms all have analyists, whose job it is to go over company's numbers, and make judgements about their future earnings, trying to find potential investments. This is basically why people hire brokers, because it's time consuming to do this reseach yourself. And the of course there is the shady side of it, collusion, insider trading, pump and dump. Those guys are all jerks.",
"People on Wall Street get rich. That is their #1 goal. Ideally Wall Street's function is to allocate capital properly. In reality, due to unrestrained greed, regulatory capture, etc., and with the help of Sen Schumer Wall Street makes money by cheating, scamming, high frequency trading, and the such. Goldman is the top bank of Wall Street, and in the word of Matt Taibi, \"the world's most powerful investment bank is a great vampire squid wrapped around the face of humanity, relentlessly jamming its blood funnel into anything that smells like money.\" Edit: typo, accurate quotation",
"At the broadest level, the financial system takes money from people who aren't spending it (savers/investors/lenders) and channels it to people who need it (borrowers), either to smooth out their income or to make productive investments. There are two main ways to do this: institutions and markets. Commercial banks are institutions that take money from savers (deposits, CDs etc) and lend it to borrowers. The US (for historical and regulatory reasons) has thousands of commercial banks, spread throughout the country. Some of the biggest ones (like JP Morgan or Citi) are based in NY, others (like Wells Fargo or Bank of America) are not. The other channel is markets. Companies issue stocks (which are risky but offer upside because they pay a share of the profits) and bonds (which offer a guaranteed return, hence safer (but not completely safe because the company could always go bust) but less upside) to investors. Other entities - especially governments - also issue bonds. Fund managers (such as Vanguard or Fidelity) put these stocks and bonds together into funds that are diversified, hence less risky, and sell them to investors. Some funds (hedge funds) take on additional risk (but, in principle, better return) by borrowing money rather than just selling shares to investors. The main stock and bond markets in the US are based in NY, but the fund managers are headquartered all over the country. Investment banks (like Goldman Sachs and Morgan Stanley) do many things, but historically have two functions: banking and trading. The banking side helps big companies issue stocks and bonds. They gauge the market demand, set appropriate prices, find big investors to take up the securities, manage the logistical aspects. Related to this, when there's a merger or takeover, investment banks provide advice and help arrange the financing. On the trading side, investment banks have proprietary \"desks\" that specialize in buying and selling stocks, bonds and other kinds of securities. Partly this helps them understand the markets so they can do better at banking and advisory, but also (some would argue mainly) it's a way to make money. Most investment banks are based in NY, so they can be \"close\" to the markets (there are some smaller regional ones). The Depression-era Glass-Steagall Law put tough limits on what commercial and investment banks could do, and mandated that these institutional types be separate (in other countries, esp in Europe, \"universal banks\" have historically done both commercial and investment banking). Glass Steagall was gradually worn down over the years, until the Gramm-Leach-Bliley Act of the late 1990s essentially allowed commercial and investment banks to do pretty much anything the other could do. They were still regulated by separate bodies, however, with the commercial banks under a still relatively strict regime run by the Fed and the Comptroller of the Currency (for larger banks) and the FDIC and state regulators (for smaller ones). The investment banks were under a \"light touch\" regime run by the SEC, which focused on making sure markets ran smoothly. Since the 2007-09 financial crisis and the Dodd Frank Act, the remaining big investment banks converted themselves into Bank Holding Companies (hence under the Fed for regulation) and have been supervised much more closely. Do they create anything? Well, they help allocate money more efficiently. That sounds pretty weak, but in a $17 trillion economy it can actually be pretty important. As we learned in 2008, when it goes wrong it can have some big consequences. There is research saying the financial system is probably bigger than it needs to be - and after a point, a larger financial system does not seem to help countries much in terms of growth. But that doesn't mean it's worthless either.",
"There is a Netflix documentary called The Pit. It explains commodities trading and all those people standing on the floor yelling at each other.",
"Buy, sell, borrow and loan, basically. On the plus side, they can diversify risk away and let people move money through time, which can unlock tons of economic opportunity and innovation. On the downside, they can amplify risk and create a lot of useless friction, especially when they give into either excessive automation or let cognitive biases get away from them. Or when they're selfish a-holes. Basically, those who treat finance as a zero-sum game destroy value, and those who treat it as a win-win create value.",
"Wall Street's intended function is the optimal allocation of resources. With many investors choosing where to put their money, the theory is that this will result in the most worthwhile and beneficial projects receiving the most capital. The incentive is pretty simple. If you direct your capital to a project you believe in (by buying a share of stock), you can later sell it for more money, once that enterprise has used your money to become successful. Or you can keep it and be entitled to a portion of the enterprise's proceeds (dividends). And for the most part, it works. The tricky part is that it leverages greed. And greed has a way of gaming it the system. The players can become less interested in the worthy allocation of capital and more interested in making a quick buck. That is why we regulate trading pretty heavily (and some would say not heavily enough).",
"Here is the \"non complicated\" answer - Wall street is a place where people with money come to make more money and where people who need money come to ask for money so they can also make more money. And here are the answers to your questions. Do they create anything? Yes. They create liquidity and opportunities for both parties in my definition above to make money. They provide services for both parties so those parties can provide tangible products and services to you, the consumer. Are they just playing with people's money? No. No one would trust their hard earned (or easily earned) money with someone who just fucks around. People want a return on their investment not someone to \"play\" with their money. Does it serve any purpose to society? Yes. The roads you drive on, the buildings you live in are all built by money that is facilitated from wall street. The products and services that are provided to you (iphones, toaster ovens, etc.) have all come from the help of wall street (loans and stock/bond offerings). If you want to learn more about finance you can try khan academy or URL_0 . Don't listen to these fucking morons on the internet who think wall street serves \"not too much\" of a purpose to society.",
"From a very basic view, they facilitate the movement of excess money (or capital) from people/funds/corporations (investors) to companies/corporations that require additional capital to create value.",
"Bank takes your money to protect it and pays your 3% interest, takes the money you're not using and loans it out for 6%. Then they go out for golf at 3. It's called the 3-6-3 plan.",
"Really, Wall St right now is more residential than business. Many of the larger financial firms have moved to midtown NYC and buildings are being quickly turned residential. Edit: I should also add that the stock exchanges all exist in data centers in New Jersey.",
"They solve this problem, mainly for companies: \"I want to do something productive with a lot of money, but I don't have the money yet.\" This is why companies sell ownership in themselves (stock) and promises to pay you back later a little more than you pay now (bonds). Doing this is very complicated, and Wall Street firms will hold your hand through processes like IPO and bond issue in exchange for a percentage of what you raise. Then, *lots* of interesting things happen because what people are willing to pay for those stocks and bonds can change over time. Wall street companies help themselves (proprietary trading) and their clients (investment banking) turn money into more money based on these price movements. This is (kind of) the same money that helps companies do expensive stuff.",
"Assuming you don't just mean stock markets, but generally the financial industry on wall street. Some people are brokers, like middleman finding two people who want to have a transaction. Imagine you have a trainload of corn to sell - you need to sell that to someone who wants a trainload of corn. Instead of calling all of your friends, you call up a Wall Street broker, who can put this corn up for sale, helping find a buisness who wants all that corn. Other people are investors. Maybe they take the corn, and hold onto it for a few days, and when the price of corn goes up, they sell it. They can also invest another way, by \"borrowing\" someone's corn at the current market rate, selling it now, and waiting for the price to go down before buying the corn back to return to the original owner. Still others are bankers, holding on to money for lots of people, and in turn lending some portion of that money out for others. The people giving their money to the bank get more money back (because people who were lent money must pay interest back), and the bankers make some money on those loans. People getting loans get money they need \"right now\" with the expectation that they can \"pay it back later.\" But what really makes wall street tick is not each of these individual transactions, but rather these transactions in all together. For every transaction that makes money, there's transactions that lose money. Thus, the banker holding on to people's money and lending it out, might lend it out to people who don't pay him back. Or maybe the price of corn goes down after you bought it and now you have to sell it at a loss, because what are you gonna do with all that corn? Wall Street has enough outlets like this such that wall street businesses can protect these \"bets\" by placing opposite bets - maybe you buy the corn, but then protect that by also betting at worse odds that the market for corn will go down. You can spread these buying and selling across different places, so that maybe you protect your corn by buying gold, or putting money in a bank. Similarly, anything can essentially be sold. Those loans that were offered by that bank? Well, those people are going to be paying interest over time. Maybe the bank would rather sell off those loans now to someone else who wants to get those interest payments. Maybe there's four house loans together that cost the bank $1million to loan out, but over 30 years the bank gets $1.3 million back (the loan plus interest). The bank could sell that to someone else for $1.1 million, thus making back their money, but now not risking those people forgetting to make their payments over 30 years. The person buying those loans takes the risk that those loans might go bad, for $0.2million gain. These sort of transactions help sellers with things, sell them when they want to, for a \"fair\" rate. It also helps buyers who want things find the things they want. In the middle, people make money off of the transactions. Some people don't like the fact that the middle man makes money. You can imagine wall street like a fancy Walmart. Walmart doesn't \"make\" those nike shoes, panasonic tvs, or lays potato chips, they buy them for less than they sell them for. What do you the consumer get? You get access to those goods in the same place, for a low price, because Walmart is able to negotiate the purchase of millions of units. Without Walmart in the middle, you'd have to find a way to get distributor-level access to all of those products, or go through a specialty shop, which would mark up the goods even more. That's not to say middlemen are always good, but perhaps a necessary evil that must be somewhat limited with a few strict rules.",
"Wall Street is a massive term for banks on and around Manhattan in NYC. Hell, even banks and funds in NJ gets lumped with Wall Street, sometimes as far as Greenwich, CT. So for argument, let's define Wall Street as most serious financial institutions in the proximity of Manhattan. These institutions can vary very much in size. From the smallest one man funds, to large investment banks with thousands of employees. The various companies focus on different things: Some only deal in certain markets and niches, while others have many different divisions that tackle these. **Investment Banks (IB)** = In general, they underwrite. That is, they raise capital for their clients (companies) from potential investors. But they also do many, many other things. Regular credit/commercial banks can't do this, because of the laws. So when you go to Bank of America (or whatever), it's not the same branch of the bank that deals with IB stuff. **Mergers and Acquisitions (MA)** = When two companies want to merge, or one wants to acquire another, they contact banks to help them structure the process. **Private Equity (PE)** = PE groups, or funds, strictly deal with private capital, and private companies. Large PE groups own private companies. If you go to a Investment Bank, and say that you want to sell your company to the best bidder, they usually get in touch with PE groups in larger banks, or smaller PE firms. **Real Estate (RE)** = Same as PE, but they own assets that are tied up to Real Estate. Want to start a fund that invests in the rising real estate prices? You contact the RE groups. **Private Wealth Management (PWM)** = The group and managers that handles the wealth/portfolio of private individuals. **Hedge Funds (HF)** = Investment funds that minimize/offset risk by hedging. Basically, if you forecast that one investment is going to rise by a rate of two, and also forecast that another investment is going to sink by one (maybe it's even tied up to investment one, in one way or another), you invest in both. In the end, you should end up with a net sum of positive one. This is a safety measure. Hedge funds have been extremely popular for the 20 last years, and you've seen all sorts of \"exotic\" types. **Venture Capital** = These funds and groups raise money for promising and new companies, i.e Startups. This is by nature very risky, but the reward can be huge. And the list goes on. So the banks either raise capital, advise, or invest on their own behalf, or on clients behalf. Clients can be individuals, trust funds, funds, global funds, companies, and what not. How do they affect you? In many ways. Look at these examples As a inventor / entrepreneur: You come up with a great idea, but don't have enough money to develop it. What do you do? One option is to contact **Venture Capitalists**. You meet up with them, pitch your idea, and they love it. They offer to back up your startup, for a share of the company. No growth = no success, so you agree. Maybe they get 70% of the company, and you / early members get the 30%. Your startup turns out to be wildly successful, and 5-10 years down the road, you and the VC's agree that it's time to let in other investors. That is, you turn your company to a publicly traded company. Well how does one do that? You contact the **Investment Banks**! Or maybe a smaller firm that focuses on the whole process. In the end, you settle for a couple of different groups, from different banks. Banks like Morgan Stanley, Credit Suisse, Goldman Sachs. Either way, your company is now being traded. Everyone can buy shares, and own a bit of your company. You decide to retire, and sell all your shares. Maybe you net a nice billion or two. What happens next? A) For your part, you can spend the money as you like. Maybe you want to invest them on your own, or maybe you contact a PWM manager to do that for you. B) For the companies part: Maybe some PE group now owns them, or a huge chunk of the company. Sometime down the road, maybe a competitor offers a Merger. Who knows. Either way, all these banks and firms have been part of the deals. Sorry for the long write-up, as it's a huge, huge topic. But the real **TL;DR ELI5** would be: Wall Street banks raise capital/underwrite, offer advisory to clients, invest money or their own, or their clients behalf. Everything that is related to Finance, they do. There's no monstrous catch-all bank that excels at absolutely everything...different firms on wall street are good at different things. You find these banks in, and in the areas around: Wall Street (NYC), City (of London), Frankfurt, Singapore, etc."
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5tstlh | Why is there a male chess competition and a female one? | Repost | explainlikeimfive | {
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"There aren't. There is the open competition, and a separate one for women only. Top female chess players have competed in the open competitions. For example, [Judit Polgar]( URL_0 ) Since most people who play chess are male, and women have felt alienated by the mostly-male environment of open chess competitions, women-only chess competitions were set up to help grow the hobby among women."
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5tupif | Why do food or drinks taste different when hot or cold? | Repost | explainlikeimfive | {
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"URL_0 URL_1 Basically our tastes buds are more sensitive to certain tastes at different temperatures, which send different signals to the brain."
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5txg3e | Why do people "Black Out" after a night of heavy drinking and can't remember what they've done the next morning? | Repost | explainlikeimfive | {
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"Alcohol messes with a part of your brain called the Hippocampus that, among other things, manages transferring short-term memories into long-term ones. The result is that some or all of the short term memories from the time you are intoxicated don't get transferred, and once your body has removed all the alcohol and you're sober again, you can't remember some or all of what happened.",
"Consumption of alcohol impairs a person's ability to form long-term memories. It's like writing an essay but forgetting to save it somewhere when you're done. You know what is going on in the moment but as soon as you're done all of that information is gone.",
"A lot of the comments here are close to the money but don't touch it just right. Alcohol is a toxin to the body. The main area where it is detoxified is in the liver. The detoxification of alcohol produces a few side products that start to accumulate in the liver cells. The most important one is a molecule called NADH, which is used by liver cells for energy production as well as glucose production. An imbalance in this molecule is created because of the alcohol, so the cells get confused and think there's enough energy, so they stop the cellular power plant, but this also stop prevents the liver from producing glucose naturally. Your brain requires glucose directly from the blood in order to function properly, so once it starts running low on fuel, it begins to malfunction. This malfunctioning is what shows up as drunkenness. As more and more parts of the brain run out of supplies, you start to become more and more drunk. The outer most parts of the brain get affected the most very early on, and the inner parts of the brain are affected later, because brain blood flow works from inside to out. The hippocampus is a part of the brain that's located very deep inside the brain. Because it's a very old and basic part of every brain, it gets a lot of blood to stay in tip top shape. When you drink enough alcohol to reduce fuel to this area, your brain cells stop firing properly, and they lose the ability to register new information. It's kind of like writing with disappearing ink. It's there for 10 minutes while you do it, because there are other parts of your brain that allow you to think and act immediately, but it can't be saved to paper. This process isn't absolute though. In between, people can eat food, or the alcohol starts to get metabolized and a little more blood glucose comes in. This lets the brain save memory in parts, and allows for atleast partial recollection of the events the next day. It's sort of like keeping a brief snapshot, which your friends help fill in the gap with. Also, alcohol can directly slow down functioning in the brain by mimicking little molecules that switch off or prevent neurons from firing. TL;DR The only thing that's known about memories right now is that they are formed in part by brain cells firing off in particular patterns. These patterns are what make memories. Firing off neurons needs fuel in the form of glucose. The brain needs fuel to work and save memories. Alcohol tells your body's main fuel factory in the liver that there's enough energy, so your brain runs out of fuel overtime. The part of your brain that makes memories runs out of fuel only when the blood sugars are too low, and that's what makes you blackout. Plus alcohol also directly prevents neurons from firing off by mimicking molecules that act like brakes. So it's a bit of a combination of both fuel stoppage, and hitting the brakes too hard.",
"I have a follow up question: why do some people black out more than others (and some, like me, seem to never black out)?",
"I'm just here to complain, none of these answers tell me what I came here to read. \"Alcohol inhibits the brains ability to form new memories\". That doesn't help. What are the mechanisms, why does it happens? We already know it happens. Edit:u/RedditorDoc hits closer to what I had been hoping for."
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5txqel | How do QR codes and Barcodes work? | Repost | explainlikeimfive | {
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"When a barcode/QR code is scanned, you are actually scanning a string of characters (ex. 123456, abcde, etc.) each character has its own distinct set of 'bars', so || | could equal 1 and | || could equal 2, ||| || is 3, so on and so forth. Once the barcode is scanned (this is done by shooting a red light at the barcode and having a sensor detect the reflected light; black reflects the least light, white reflects the most) the black and white lines are translated into binary (1s and 0s, so black black white could be 110) and sent to the computer where the information can be translated into some useful information like price, name, etc. QR codes work essentially the same way, but instead of bars its black and white dots. \"But why not just scan numbers and letters themselves?\" you might ask. Well, barcodes tend to be much more reliable than letters and numbers. 0 and O might be mixed up or I, l, 1, you get the idea. Having each character be represented by bars/squares simply produces less errors. so with the basics of barcodes out of the way... 1. I can use an app on my phone to scan one of them; why do stores need a fancy machine to scan them? although stores could technically use phones to do all the scanning and pricing for them, dragging the item across the scanner (like they do in most stores) is simply much easier and faster than aiming the phone at the barcode for each item. As for calling those machines fancy, they actually just translate black and white lines into 1s and 0s. That metal square you (and all of us) have religiously bound ourselves to is a much more complex device :) 2. If my phone can read them, does that mean it's just a picture that, once scanned, can take you to a website and such? yep, your phone scans the QR code, translates the black and white boxes into a website link, and goes to that website 3. If so, do all brands need to work together to make sure two different products aren't given the same code? Yes. Well, sort of. So let's say you are the CEO at Snapple and you want to release a new flavor. Before you can start manufacturing the new Snapple flavor you have to order what us called a UPC, or Universal Product Code. This is basically a unique 12 digit code that isn't on any other commercial product. So brands don't necessarily work together to maintain fully unique product codes, but rather all brands answer to some upper corporation that makes sure all of their products have unique barcodes sorry if i forgot some stuff or didn't elaborate on something else, its 2am here and I'm pretty worn out"
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5ty8la | How do placebos function? | Repost | explainlikeimfive | {
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"For the most part, they don't work. The placebo effect isn't about positive thinking or willpower or anything like that. Placebos have almost no objective effects. But assessing how you *feel* is very subjective, and easily influenced. Placebos play into that by making you *think* you feel a little better. > if there was a drug to cure the common cold virus, and a placebo also worked to cure that cold virus because they believed it was the medicine, That is not what happens, the placebo doesn't cure anything. If you are sick and take a placebo, your temperature won't go down any sooner, less snot won't come out of your nose. All that happens is the expectation that the pill will make you better causes your self-assessment of how you feel to go up a little.",
"> Can the actual willpower of thinking you'll be cured from that actually cure you? Pretty much, yes. That or just circumstance. For example, most people who have the cold will have the cold go away on its own relatively soon, so they would think it was from the medication when it was going to go away anyway. In this case, though, if the \"drug to cure the common cold virus\" had *the same* effect as a placebo, it means the drug almost certainly did nothing at all to cure the cold and it was just the placebo effect there, too."
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5tzvwg | What is the difference between an expat and an immigrant? | Repost | explainlikeimfive | {
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"As a political commentary they may be right. But as a literal definition no. An expat is a person living in a country where they are not a citizen, and often retaining the option to return to their native land. An immigrant is a person living in a country where they are (or seek to be) a citizen, and typically to spend the rest of their live and their descendants' lives there. URL_0"
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5u31wq | What makes the "I'm not a robot" captcha hard for bots? Can't spammers just create a program that clicks on the box? | Repost | explainlikeimfive | {
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"The \"I'm not a robot\" captcha takes into account more than just the click itself. It takes into account factors like \"time spent on page before click\", \"mouse path to button\", \"accuracy of click\", et cetera, to predict whether you're an automated software or an actual person.",
"If you're logged into a google account, google looks at your account activity to decide whether you're a person or not. If it's not sure you're a person, you get to click on a bunch of pictures of store fronts or road signs.",
"Sure, but the way that the bot clicks that box is very telling. If the mouse snaps exactly to that square, instead of moving to it like a human would, then it's a bot. If the whole page gets filled in at the same time the mouse is moving to the box, then it's probably a bot. Things like that.",
"One other thing not mentioned: spambots aren't usually using browsers like how an ordinary person would. It does not usually work through a graphical user interface, it just submits form data after form data. Think of this captcha more like a speed bump. If it restricts bots to the same speed as a human spammer could (which captchas can't prevent anyway), then it's done its job.",
"Sure they could make a bot do it, but they have to vary the time, and path of the cursor into the box, and the co-ordinates of the click too. which is dramatically harder than just sending a \"mousedown\" event at \"location of checkbox\""
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5u4ahy | Why isn't 17th-19th century style classical music not composed anymore? | Repost | explainlikeimfive | {
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"Composers of 20th/21st century classical music are always pushing the genre forward and looking to do something new. If they wrote something which was too close to the music of centuries ago, it would be dismissed as a \"pastiche\" and not a new work of art.",
"[It is still composed.]( URL_0 ) Aside from film scoring it just tends to be less visible, overshadowed and squeezed out of airplay by the traditional masters of the genre.",
"Its definitely still being made, it's just not so mainstream. Most composers of such music nowaday tend to work in Film and TV creating musical scores. John Williams, Hans Zimmer, Danny Elfman for example..."
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5u4kxa | Why is Venezuela's economy in utter collapse when they're a major oil exporting country? | Repost | explainlikeimfive | {
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"Since the end of 2014, the price of oil has collapsed. Prices went from aroun $100 per barrel down to $38 per barrel and stayed depressed ever since then. So essentially their national income has fallen by 50%. Couple that with their debilitating socialist obligations and anti-business tendencies and it's a recipe for financial ruin."
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5u6uyl | Why do a significant number of people still deny climate change? | Repost | explainlikeimfive | {
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"It's become subject to partisan politics. There have been interesting studies that show once people's emotions are involved facts lose a lot of meaning. We think of ourselves as rational beings but in reality it's very easy to ignore evidence that doesn't conform to your world view and to selectively give weight to evidence that supports your emotional position."
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5u88jv | in low light conditions, why is it easier to see objects by looking next to them, rather than right at them? | Hope I explained my question well. I find it hard to see things by looking directly at them in low light. By looking next to the object I want to look at, it becomes more clear. | Repost | explainlikeimfive | {
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"There are two types of light detecting cell in your eye, cones give you color vision and are highest in density at the fovea(the part of the retina that corresponds to the center of your vision). Rods are more sensitive, react faster, don't filter colors, and are a higher density outside the fovea. Basically, the center of your eye is optimized for inspecting things and noticing subtle differences in color, while the rest is optimized for high sensitivity/fast reaction time. It's the high sensitivity part that lets you see stuff more easily in low light.",
"This is an effect of how our eyes have evolved. Our eyes color receptors (\"cones\") are located in the central part of our eye and they make it easier to see detail and color but are not as light sensitive in low light conditions. Our peripheral vision uses \"rods\" which are not color sensitive and less detail sensitive but are more light sensitive in low light conditions. This may be because when reacting to something you see in your periphery it is more important to see that SOMETHING is there rather than what exactly is there so you can either flee or turn your head and eyes to then use the more detail oriented part of your eye to see what it is."
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5ua9q2 | Why is it called the 3rd world, where is the 2nd? | Repost | explainlikeimfive | {
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"This term is a heritage from the Cold War. There were the NATO-aligned first world, the Soviet Bloc-aligned second world, and the third world were the remaining non-aligned countries.",
"2nd World refers to the former communist countries of the Soviet Union and other socialist and industrialist states. There's quite a bit of info if you just Google it."
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5ub3pl | why do the white ceiling tiles (seen in all schools) turn brown when wet? | Repost | explainlikeimfive | {
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"I believe it's because the outer white covering that's \"moisture resisant\" becomes transparent and shows the inner brown material. The inner material also looks darker when moist."
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5ubdlv | How did the first programmers program programs? For example, how did they program the Operating System or CMD if they had no programs or programming languages. | Repost | explainlikeimfive | {
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"Step 1: Build a computer that can only be programmed by physically moving wires around to change the patterns of 1's and 0's. Step 2: Get sick of that, so create a computer that can read those ones and zeros off a physical medium, such as a long strip of paper, or cards. This is called programming in \"Machine Language\". Step 3: Get sick of writing ones and zeros for the commands, so give names to the various opcodes, such as \"LSR\", for Left Shift Register. This is called \"Assembly Language\". Write a program that does a 1 to 1 translation of assembly command to machine command. Step 4: Realize that you keep doing the same sequence of assembly language instructions over and over, so you create a program that can convert a special command, such as \"loop X times\" into that sequence of assembly language commands. Step 5: Keep adding more commands, and realize that symbolic addresses are useful, too. Before you know it, you have a compiler for a high level language, written in assembly language. Step 6: Do future iterations of this process in the higher language to build even higher level languages.",
"How do you mass produce tools? First, you sort of cobble a tool together using whatever you've got. Then you have your proto-tools, you use those to bootstrap yourself up to the next level, hand-crafting your nice tools. Ok, now you have some actual tools, but you still haven't gotten mass-production. So you use your nice tools to build some tool-building tools, and then once you have those, you build some tool-building-tool-weilding automation systems (you could call them robots, or factory lines, depending which era you're talking about). And so on. It's basically just bootstrapping again and again and again. Somebody took the first circuits and said \"if I connect these two wires in this way, I get this output\". Somebody else said \"well let me take some circuit boards and print them in such a way that it's easy to switch the inputs around to get different outputs\". Then somebody said \"cool, now that you have that, I'm going to come up with a set of common rules on how best to get a certain output using these circuit paths. As long as your circuit machines follow this convention, other people can quickly bang out circuits using that same convention without having to build it from scratch every time\". That's assembly. Then somebody else said \"ok cool, but some people don't really understand circuits, so I'm going to abstract that one level further\". If you are a programmer, any time you abstract some concept into an easier to use API, you are doing the exact same sort of process the early programmers were doing. They just didn't have so many shoulders to stand on as you do. When I write fetch('/foo').then(r = > r.text()).then(console.log.bind(console)), I am not actually thinking about all the various pieces that breaks down into. But somebody else at some point said \"you know what, javascript needs a way to make http requests\". And somebody before them said \"you know what, there should be a quick and easy way to make a standardized tcp connection to a server, receive some data, and close the connection\". Somebody before that said \"I wish there were a protocol that would help me send packets of data across a network in a standardized way\". Before that somebody said \"I wish there were some way to beam bits of light across ethernet cables\". etc. Obviously take these generalizations with a grain of salt, I'm sort of making it up to prove a point.",
"The operating systems, and compilers are all there to make life easier. As a child I had a z80 computer which came as a box of components and a circuit diagram. The input was three banks of buttons one (8 button bank) for the byte, one for the address and a small number of functions like write memory, show memory, run program and the like. To write a program for this monster I would get a piece of paper and work out what i wanted it to do. I would then write (by hand) the machine code instructions and then refer to another sheet of paper with the binary equivalents for each instruction. I then used some graph paper on which i had columns for memory address, op code (the command) and the data, all written as 1's and 0's. I would then use the keyboard to enter the memory address (in binary) and the command or data i wanted to enter. After many hours I would then hit the run button and watch as the bank of 8 Light bulbs would flicker in a set sequence, and have to start all over again as the computer had no long term memory. Earlier than that, NASA and other organisaitons used \"braid memory\" which is literally bundles of wires braided together into the binary patterns for the program to be run. This means that rocket's flew into space running computer programs entered into them by little old ladies basically knitting miles and miles of wire. ( URL_0 ) And even earlier than that the Bombe (a code breaking computer from 1939) had rotating switches for memory, you programmed it by turning dials for each memory location before running it. Although the bombe was only capable of running one \"program\" without physically re-building it, and the memory was more like a saved configuration file for that program in today's terms.",
"With hand entered machine code, computers take binary numbers as commands and data. If you know their instruction set specification and are patient you can write them by hand. Very early computers had a bank of switches, set 8 or so binary values and then flip the \"submit\" switch.",
"Are you asking us how programmers programmed programs when they didn't have any programming programs to program programs with? If you look at the predecessor to Windows, MS-DOS, you will notice how simple it is, and how little it could do. So somebody wrote compilers for it, which allowed people to write more complex programs for it. Then people wrote graphical Software Development Kits, and slowly the beast just grew and grew. What was important here was the fact that everyone settled on using the same computer - what was known as the IBM-compatible, or as it's called today: The PC. I had an 8-bit machine back in the eighties, and we could buy magazines with programs to enter. It would come in the shape of a page of machine code, and a tiny BASIC program that you could enter the machine code into in order to write it to disk. Oh, yeah, and if you got any of the bytes wrong, you'd just crash and would essentially have to start over. I'd say \"Good times\", but damn it, it wasn't. The 8-bit processor would itself come with a ROM - read-only-memory, which would provide basic functionality. To the best of my knowledge, this was actually hardware. As in, the programs were written with logic gates. I did have a PASCAL compiler back in the mid-eighties, but the compiler itself took up most of the disc space itself, so you couldn't really do much with it. :p TL;DR: With logic gates and machine code. And very slowly.",
"I am enjoying this topic, so let me try my hand at explaining it. ------------------- First, you must understand that a computer is essentially a really complicated series of switches. Each switch does something specific with a bit (1 or 0). Flipping a switch may send a bit to one place or another. A different switch may save that bit for later. Yet another switch may flip a series of other switches which all preform a more complicated action like binary multiplication. It may even do something really fancy, like light up a pixel on an external display. As you can imagine, a computer has a lot of these switches in the processor. Millions or billions of them in fact. Basically, way too many to set individually. So, when we design a chip, we make a few switches that control all the rest of them. We call this an instruction. An instruction for a simple processor may just be 8 bits, something like '11001100' which means we turn on the 3rd, 4th, 7th, and 8th switches, while leaving the others off. When you use the switches this way, it may cause a cascading action that adds two bits together, and outputs the result. Now that there are easier instructions, users can just input the instructions that they want the computer to run, one at a time! This is effectively a language, called machine code. Old-school processors came with a thick book of instruction decodes (Add A to B is 11010001), and you would have to run it that way. Okay, so users can put in one command at a time. Too Slow! So what we do is save commonly used commands that handle standard tasks, such as reading a keyboard press, displaying text on a screen, or reading a harddrive. All these simple tasks can be saved to a memory chip that runs the moment we press the power button, and continues running as long as the computer is on. So that way, it knows when you press the keyboard for example. But still, no person programs in machine code these days. Instead, we abstract that by making a language that is easier to read and write. Something like C, or Python. So what we do is write code in those languages, and then another program turns that language into the machine code that runs the computer. -------------- TL;DR - Basic tasks that are necessary to get a computer to a point where you can program it are hard coded 1s and 0s that drive the transistors in your processor to a state where you can load more complicated code.",
"Before digital computers, there were very advanced analog computers. When they built the first digital computers, they just came up with a way to represent electronically the things that were already being done with gears and levers and cogs and wheels. Read about the amazing machine that was the Mark 1A Fire Control Computer here: URL_0",
"It was done by physically plugging in cables. URL_0",
"They used straight up binary and machine code until they created assembly which they used to create the higher level stuff.",
"old guy here. In college we had assemblers, compilers. After i graduated (1975) I built a MITS ALTAR. My assembler was a pencil and pad of paper. I hand toggled in byte by byte. After a while I built an EPROM board, put a bunch of utilities on it, and had sort of an operating system.",
"Lots of long answers, so here's a short one. Programming languages are like regular languages. They are words and symbols that we use to put ideas into writing. Instead of stories, programming languages write recipes for the computer to execute. You can write recipes with a much simpler language; think of how a caveman talks. It's more difficult to express complex ideas, and it takes longer to do, but it can work out to mean the same thing. Assembly is the lowest level programming language, and it corresponds directly to machine instructions. Things like \"Add these two numbers\" and \"Write this register to memory.\" Assembly is still required when writing code for embedded systems, especially for when a microcontroller starts up and needs to set up a C or C++ runtime environment. So even if you are using a higher level language, you are likely going to compile some assembly in there just to get started.",
"All of these answers answer your question on a general level, but I would really recommend reading [Code: The Hidden Language of Computer Hardware and Software by Charles Petzold]( URL_0 ) for a deeper understanding. He talks about how the first computers were built and how they were programmed, and he does it in a way that's understandable even to a person that doesn't know a thing about computers.",
"almost every answer here fails to answer your question. none of the previous threads posted by mod answered it either. you are not really asking what is the first program, but rather how does the first program interact w/ hardware. how does a computer (hardware) at the end of the day understands code (lines of abstract letters and numbers). it starts w/ CPU, which has built in instructions made by the maker. these are physical circuit that are wired to do specific things. for example, one instruction always add two things together. one instruction is compare two values. one thing is store it to ram. etc. etc. each instruction can be called in sequence to do amazing complex things. this video explains how a CPU is built to understand basic instructions and how to trigger them URL_0 we build software that essentially manipulate the wires of the CPU by sending charges thru wires, and since there are tons of these wires and we are sending these instructions billions times a second, it can do crazy powerful thing, so much so that CPU has evolved to have special instruction built in to do things like decode MP3, or compress video files, or 3D game, etc. when u turn on a cpu, imagine a specific list of instructions are fired in sequence, that has been hard coded into the hardware (storage or firmware depending on the device). this software then allows other things to be executed.",
"I think binary is beyond the ELI5 approach. But if you understand that a decimal number can be written in binary like 5 is actually 101, this can correspond to wires with voltage flowing on the '1' wires, and no voltage flowing on the 0's. I can attach these wires to a CIRCUIT. Some smart guys came up with electric circuits that can do mathematical operations. This isn't as magical as it seems, for more details see the bottom of my post. So they make a circuit that takes maybe 16 wires as input, and depending on what the 1st 4 wires do, directs the rest of the current towards different circuits. So if the first 4 wires are 1010 it uses the 'add' circuit. And if it's 1011 it does a subtract (this is just an example). I can do adds and subtractions all day but finding the output of basic math (even really fast) isn't going to change the world. I need to at least store some of the results. So some guys develop a circuit that when you send some current in it stores that value and outputs the last thing stored inside it. This is data storage and I'm not going to explain this part suffice to say it's the magic of transistors. I can do math and store stuff now. Still not very dynamic. What if every operation I send in I label as instruction 1,2,3, etc. And they have their machine (henceforth known as PROCESSOR) go down the list of instructions sequentially. Now I make an operation (circuit) called JUMP (just like add) that moves the Processor back to an operation of my choice. How does the processor move between operations? It stores what the next instruction # should be, so I just change that number. So now instruction 9 could say go back to instruction 2. Now we have loops. We'd also like to be able to make simple decisions like comparing two numbers. This is actually pretty easy; A human would look at each digit individually until he/she found a difference. That's too slow for a computer. The computer just subtracts number1 from number2 and checks if the result is 0. If it's not 0 then clearly num1 and num2 weren't the same. SO Basically... the guys with the punch cards had holes open and closed on the paper. They'd have metal connectors that would fit through the holes in the punch cards which would allow electrical current to flow through some inputs and not others which would turn voltage on wires on and off. They could write rudimentary programs with those and they'd usually receive the output from an actual printer. Those rudimentary programs wrote tools to help write more complicated programs, and this happened over and over until we now have modern computing. Obviously technical progress in memory capacity and cpu speed helped. If the original engineers had the same memory/cpu's we do today they would've done things completely different. Like other disciplines, computing builds on what other giants have done before you. The first \"operating system\" was some guys who wanted to be able to run some common programs instead of loading stuff from tape or punch card every time so they stored the programs in memory and wrote some code they could type a name into and it would run the program with that name. This is not all that OS's do... They're much more complicated now, but that's certainly a part of what they do. Anyway I promised some basic stuff. There are some logic gates that you put on a circuit. They make these with collections of transistors. One is an 'AND' gate. This will output a 1 (voltage on) if both inputs 'a', and 'b' are also 1. AND a|b|output 0|0|0 0|1|0 1|0|0 1|1|1 OR (outputs true if Any input a or b is on) a|b|output 0|0|0 (no inputs on) 0|1|1 (b is on) 1|0|1 (a is on) 1|1|1 XOR ('exclusive or'. Outputs 1 if a or b is 1, but 0 if both are 1. a|b|output 0|0|0 (no inputs on) 0|1|1 (b is on) 1|0|1 (a is on) 1|1|0 (both are on, and xor doesn't like that) Now we'll do a basic 'add' in binary without a carry digit. how about 0 + 1, 1+0, and 1+1... 0 1 1 1 0 1 --+ --+ --+ 1 1 2 ... ok but 2 doesn't exist so like 9+1 in decimal we write 0: 1+1 = 0 * where * is a carry. You'll notice that this lines up with a xor gate. Meaning if both inputs for a given digit spot are true or both false, the output is 0, if only a or b is 1 then the output is 1. So my simple adder takes 2 inputs a and b runs them both through an 'and' gate for the carry output, and a 'xor' gate for the adding. I have two outputs a carry and the result. This gets a little more complicated now.. My next adder needs to account for 3 bits as input.. a, b, and C where C is the carry. This is possible, and it's how math is done in a computer. It's just getting a bit too complicated for reddit now. You chain a bunch of these adders together like say maybe 64 of them... And you can do addition of 64 bit numbers with a simple routing of electrons."
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5ue0lp | How do insects walk on walls? | Repost | explainlikeimfive | {
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"They do not weigh much. Remember insects also fly. Not weighing much has a lot of advantages. Walls are not smooth, not microscopically. You know this when you put you hand on one for support. The infinitesimal weight of a bug is supported by their equivalent of a toe and fingerhold.",
"Van der waals forces. When something slightly positive meets something slightly negative, they will attract. This is occurring in their legs with the wall on a microscopic level. The electrostatic attraction > gravity.",
"Things like insects and gecko's tend to have skin on their legs/feet that give it a really large surface area. This allows the van der Waals forces between the wall and the creature to be strong enough to support its weight Below is a close up of a gecko's foot under a microscope. Its similar thing with insects where lots of hairs are present to increase surface area URL_1 Also found a fly's foot for comparison URL_0"
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5ue0vr | Why is everyone on reddit explaining their edits? Even when it is just a typo and they added 1 letter, they write: "Edit: Typo. I was on a phone" or something like that. | Repost | explainlikeimfive | {
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"You can troll people by posting something, waiting for people to reply, then edit your post to something else so the replies no longer mean what they intended. E.g. You post something innocent like \"noodles are the best food\". Someone replies \"I agree\". Then you edit your post to say \"Hitler was right\". Now it looks like the other person is agreeing with that. To combat this, reddit shows a star next to posts that have been edited. So if you see that star, you know that the post could have said something very different originally. So when people edit for legitimate reasons, they say what they edited so you're not left wondering if the post originally said something completely different.",
"Because you get the asterix (*) character to let people know you've edited, now if you wrote something that attracted unjustified criticism ( on reddit ? Who'da thunk ?) then the edit might make people think you're not standing by your post (again, remember the audience here) so a harmless edit to correct typos is mentioned."
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5uf1id | Why does drinking coffee speed up my bowels? | Repost | explainlikeimfive | {
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"[Pours 3rd cup this morning] \"looking forward to reading the answers to this in about 30 minutes\""
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5ui48e | If we replace our layers of skin, why do we still have scars? | Repost | explainlikeimfive | {
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"Skin is actual made of of three layers: - The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone. - The dermis, beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands. - The deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue. The epidermis is the part of the skin that gets refreshed often. If you damage that it will just refresh itself, no big deal. The dermis doesn't replace itself, so if you get damage that deep, you will develop scar tissue."
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5ui6oh | Fast food locations | Why do some fast food joints place locations right next to each other? For example, next to my neighborhood there is a Burger King, but in the Walmart across the street there is another burger king. Doesn't this cannibalize sales? | Repost | explainlikeimfive | {
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"It's called [Hotelling's Law]( URL_0 ) and it basically says it's more profitable to split an existing customer base with a competitor than to try and find customers further away from where customers are already proven to be.",
"Burger King has looked at the demographics and doesn't feel that it cannibalizes sales enough to justify having only one store. The idea is that people who want Burger King won't go into the Walmart to get it, and people in the Walmart won't leave to go across the street."
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5ujyhg | Why do we get the feeling that we are being watched? | Repost | explainlikeimfive | {
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"I'm not 100% sure how accurate this is, but I've heard it described as a prey instinct. Basically, your body is taking in more signals than you can consciously interpret, so a lot of them are off loaded to your unconscious. It's a holdover from when we lived in tiny tribes and were in danger of being eaten daily, your subconscious would be on alert for the predators and give you a sense of wrongness if something didn't jibe. So when your mind detects that the information it's collecting doesn't all match up, it gives you this feeling of wrongness or of being watched. A common similar example is nausea while in a car. You see the landscape fly by but you feel like you're stationary. So in response, your body thinks that it ingested poison and needs to throw up the poison. Again, I think this is accurate but it may be totally wrong ¯\\_(ツ)_/¯"
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5uljuf | Why do some countries use daylight savings and is there a real need for us to use it? | Repost | explainlikeimfive | {
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"Without DST, in London the sun would rise at 3.45am. That \"wastes\" a lot of daylight when most people are asleep. Applying DST \"moves\" an hour of daylight from early morning to the evening, when more people are awake. Originally, the motivation was to reduce the fuel needed for heating and lighting in the evening. You could achieve the same thing by getting up an hour earlier, but changing the clocks gets that effect without changing everyone's schedules.",
"Others have already explained the basics, but no one has mentioned the importance of geography yet. The further you travel in distance from the equator and the closer you are in time to the solstices, they greater the difference in length between night and day. Daylight savings time makes perfect sense in Helsinki, Finland and Invercargill, New Zealand, but none at all in Quito, Ecuador, where every day is an equinox."
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5ulx5q | Why as a modern society do we worship celebrities and sports entertainers while intellectuals like academics and pilosophers seemed to get a lot more recognition in ancient times? | Repost | explainlikeimfive | {
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"The short answer is that they didn't. It's just that we don't have that many records of much 'popular' stuff from ancient times.",
"I don't think that's true. Sportspeople and entertainers have been popular for millennia. The Roman chariot races have been mentioned. Mozart was highly popular in his time. And so on. And conversely there are some academics that are quite well known today. Stephen Hawking, Brian Cox, Neil DeGrasse Tyson."
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5umkan | Could I use a bucket of dirt to ground a small generator? Why or why not? | Repost | explainlikeimfive | {
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"No. \"Grounding\" is not about having access to some dirt. Grounding is about having access to an object so huge -- usually the planet Earth itself -- that it can absorb unlimited amounts of electricity without becoming noticeably charged.",
"No, because the bucket would act as an insulator. If you are really worried about grounding a generator just go to Home Depot, they sell long copper spikes, get a small sledgehammer and pound it into the ground near the generator. Then use a wire clamp, sold right near the copper spike, to connect it up with a piece of 12 gauge or thicker wire. However, for most purposes, you don't need to ground a generator, unless it's a semi permanent installation. I think most generators now have GFCI outlets as standard, which should provide enough protection.",
"If you want to use that \"grounding rig\", lose the bucket, put a metal clamp of some kind at the end of the wire (think of jumper cable clamps), and clamp it onto anything metal that is anchored into the ground, like that platform/walkway/railing that the generator is shitting on.",
"No, the purpose of the generator ground is to provide a low-resistance circuit from any point where the generator feeds power back to the ground point. Sticking a conductor into a (?plastic?/even metal on grass or dry surface) bucket is not going to serve the purpose."
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5un3c5 | If ageing is a biological process, how does time dilation slow it down? | Repost | explainlikeimfive | {
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"Time dilation changes the rate at which time passes relative to someone else at a different speed. Imagine that you are on a spaceship and you have 10x time dilation relative to Earth. To you, you age normally. If you are 20 now, and live to age 90, then you will experience 70 years of growing and aging. The aging process doesn't really change. But at the end of those 70 years, 700 years will have passed on Earth. The people on earth age at the proper rate for that frame of reference, and you age at the proper rate for yours. So, while 700 years will pass on Earth during this time, you wouldn't experience it as 700 years -- just 70."
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5unn0w | What is it in music that makes minor notes sound sad and major notes sound happy? | Is this an intrinsic characteristic of the music- i.e there is something in major/minor notes which evokes a certain response in the brain, or is it more of a cultural response which has been conditioned over time? | Repost | explainlikeimfive | {
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"**Perform a keyword search, you may find good explanations in past threads. You should also consider looking for your question in the FAQ.** This has been asked a ridiculous number of times in the past. Like, possibly more than \"why does mint gum make water feel cold in my mouth?\" URL_0",
"Two notes played together sound most pleasing if their frequencies are in a simple ratio. 2:1, 3:2, 4:3, to our ear they blend the best, and give a sense of order and well being. Ratios that blend less well, like 6:5, sound less orderly, and when compared to the simpler ratios, give the impression something is amiss. Music that uses major chords and intervals utilizes the simplest ratios, and sounds more pure. Music that uses the various minor chords sounds more dissonant."
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5uq9dy | Why does a PC that has not been reboot in a long time run poorly? | Repost | explainlikeimfive | {
"a_id": [
"ddw0j3y"
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"text": [
"There are a lot of tiny data from processes before that didn't get deleted and also a lot of defective datas that just take away space or stop programms from working propperly. Like a gear-wheel that looses spikes or gets sand inside. The reebot renews the gear-wheels and makes them run smooth again."
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|
5uqjmp | How did popcorn become the standard movie watching snack? | Repost | explainlikeimfive | {
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"text": [
"I believe it came from being a cheap food that was incentive for movie goers during the depression.",
"im just guessing here but it might be because you can throw it at some blabbermouth in the theater without doing grievous bodily harm"
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5urpmv | What is a 'port' (with regard to file sharing) and why are there seemingly tens of thousands to choose from? | Repost | explainlikeimfive | {
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"text": [
"Your computer has an IP address, which is like the address of an apartment building. It tells the network where to send messages. Within your computer there are multiple programs. Ports are like post boxes in the apartment building. They're there so that when a message comes in from outside the computer it knows which program it should be delivered to. Ports are identified by a field in the headers of TCP and UDP messages that is 16 bits wide. That means there are exactly 2^16 = 65 536 of them. Normally they're represented as the numbers 0-65 535 but we don't really do math with them - they're really just strings of bits we assign to particular programs for a while.",
"It's just a more specific way of breaking down where to send a packet. For example, your connecting to 7.12.54.75 over standard internet connection. Well, that IP address is used for many different protocols like web browsing, file sharing, email, encrypted web, etc. So you specify what protocol you're using. Http is port 80. So you're basically saying \"I would like to talk to 7.12.54.75 via standard internet\". You could also do it encrypted via port 443. It's like adding a zip code to an address. It helps route things faster to the right destination, rather than trying multiple different post offices until you get the right one with 123 Main Street.",
"Lets say I have a apartment building address. You go to that address but you realise that you were not given the apartment number. Which apartment am I supposed to go to? This is when port numbers come into play. A port number is like a apartment number which tells where to send the packet (or in the analogy, the person) at the given IP address. Lets say I have a apartment number 80 which is running a web sever. Now I know where to go since I have the apartment/port number and now I am able to retrieve/send anything from that specific apartment/server. 192.168.0.1 would be the street name and apartment building. Port 80 would be the apartment number. This is usually displayed as 192.168.0.1:80"
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5urrv4 | How are the kcal of food obtained? | Repost | explainlikeimfive | {
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"ddwgzrv"
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"text": [
"In a lab setting you use a bomb calorimeter - essentially you burn the substance and measure how much heat is released. Practically, edible food only contains a few different types of digestible components - carbs, proteins, sugars, etc - and the calorie/mass amount for each is well known, so just by knowing the ratio of each in a substance you can fairly easily calculate it's overall caloric value."
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|
5us466 | Why is CCTV footage almost always blurry and low quality? Considering how much better video technology is | Repost | explainlikeimfive | {
"a_id": [
"ddwexk3"
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"text": [
"Video takes up a lot of space and CCTV is always recording, 24 hours a day, 7 days a week. And then I'd rarely ever just 1 camera, so if they were all HD, even a 1TB drive could fill up in less than a day."
],
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|
5utdfr | What does salt do to snails? | Repost | explainlikeimfive | {
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"ddwoizr"
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"text": [
"Snails and slugs have an outer mucous membrane with water-based slime on the outside, The saltdissolves in this slime, forming a highly concentrated solution of salt. ... As a result, they shrink for loss of moisture, and a pool of salty water forms around them. - Quora"
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5uttnp | How do some people say the holocaust never happened? | Repost | explainlikeimfive | {
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"ddwsb4v"
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"text": [
"“Get it all on record now – get the films – get the witnesses – because somewhere down the track of history some bastard will get up and say that this never happened.” – General Dwight D. Eisenhower, on future Holocaust denial"
],
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|
5utuo5 | What is the actual difference between premium fuels and regular ones besides the price. | Repost | explainlikeimfive | {
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"It is not really \"premium\" in that sense. It's not a better gas for your car. What it means is the octane rating is higher, meaning it needs more compression in order to explode (which is how car engines work). Luxury cars and \"sporty\" cars use higher octane fuel, but only because their engines are specifically designed for that octane. Putting it in a car designed for regular will do nothing. If you want guaranteed better quality gas, visit a Top Tier station, such as Shell, Chevron, Costco, etc. These stations have submitted to testing to show that they have more detergents than required on all their octane variants, which causes less carbon buildup and other benefits. Now, that doesn't mean gas stations not rated Top Tier aren't as good, it's just that Top Tier stations are guaranteed to be good.",
"So... \"Gasoline\" or \"petrol\" is typically measured on its \"octane rating\". Octane is just a hydrocarbon made up of 8 carbons and can be straight, branched or cyclic. However, the combustion properties of n-octane, that is H3C(CH2)6CH3 are well studied. In an engine you are compressing and heating a fuel in the pistons which causes the fuel/air mix in each piston to explode and drive the engine. Pure octane does this at x pressure and y temperature. Higher performance engines may run at higher compressions, and higher temperatures for various reasons. Because of this, n-octane may explode sooner than optimal in the engine cycle. Thus you use a \"higher octane\" fuel, which explodes at a higher temperature/pressure. The \"pre-detonation\" or \"knocking\" can be noticed when low grade fuel is used in engines designed for high octane fuel, however \"normal\" engines will not experience any noticeable difference in performance.",
"These Answers suck and in one case just wrong. Here's the correct answer, but in a few parts. 1). The way the engine works is by compressing the gas/air then making it explode. Pushing the piston down. The best time for the explosion to happen is right around the time when the piston is about to go down. [IMAGE]( URL_1 ) 2). Stuff Blows up when it's hot. If you put paper in the oven at ~~451ºF~~ Around 500ºF it will catch fire. Gas is the same way. There is a temperature which gas will just catch fire. 3). Doing stuff creates heat. If you take a paperclip and bend it over and over again you'll notice where you bend it gets hot. Similarly as car engines do stuff they get hot. Higher performance engines are doing more stuff in a shorter time so they tend to get hotter. Combining 1,2, and 3. You put gas in a performance engine. The engine gets so hot that the gas burns before the piston is ready to move down. Now the engine is pushing up while the explosion is pushing down. This can damage the engine a little (so little it doesn't matter) and wastes energy. So how to stop this. You have to change something in 1,2, or 3. Without 1, the engine doesn't work. You need that motion. 3 cannot be changed because that's just how the universe works. You're left with 2. You can change the temperature at which gas burns. By making the temperture higher then you stop it from burning when it shouldn't. OK now a little older stuff, for the teenager. When do you need 91 octane (premium). It's when the engine is working in such a way that it is really hot. This normally happens with engines running really fast as a lot of heat is created in a short amount of time. So if your car has a redline of maybe 6,000 rpm. It might only need this more expensive fuel for the times you are running over 4,000rpm. Which if you drive like a grandma is never. If you drive like me, that's only for a few seconds after a green light. Super Chargers and Turbo Chargers. These compress air to put more \"Stuff\" into the engine. More air and More gas = More Power. But by compressing stuff you make it hotter. Thus air going into the combustion chamber will be hotter from a turbo/super charger engine then without one. This means turbo/super changer cars are more likely to need a higher octane. Premium spin. There are also some cars which say premium only. This is often times just a marketing ploy. You spent a lot of money on your car so of course it needs the more expensive gas. Not true. In fact ~~most~~ cars now days can sense if you're using Premium gas or Regular. The computers will adjust to prevent this early burn from happening. (Early burn, or predetonation, creates a sound called knock. You have in your car a Knock sensor which listens for this boom) Edit: Article = URL_0",
"Higher octane rating means the gas is less likely to explode too early, which can be a problem in engines designed for higher performance. An engine will not benefit from a higher octane rating than is recommended in the owners manual, assuming the other non-octane additives are equal."
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5uuf3v | How can the average person prove the earth is round? | Repost | explainlikeimfive | {
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"Stand next to the ocean and watch a tall ship sail over the horizon. If the earth were flat, it'd just recede into the distance forever, but instead the ship seems to disappear from the bottom up. That's how the ancient Greeks knew the Earth is round!",
"You know that we have picture of the earth from multiple angles that show it as round. If they can't believe their own eyes they may be too stupid to exist.",
"Get a weather balloon from eBay and tie your GoPro to the end of it.. maybe tape your iPhone to it so you can find the contraption when it lands. It would certainly get high enough to begin to see the curvature. People have done it in the past with more elaborate contraptions, but it could easily be done for a few hundred USD. Would it convince them? Probably not.. Some people just want to believe what they want to believe, evidence be damned..",
"The sort of proof you can provide is not the sort they will accept. The Earth being round(ish) is the simplest explanation for a wide range of phenomena. Flat earthers jowever, proefer to cook up complex and convoluted explanations for the same thing. Example, they will say you don't fly around the globe, you circle the circumference of a flat earth instead. It's difficult to prove them wrong mostly because the standard proofs rely on some basic physics the flat earthers refuse to accept. I wouldn't get worked up about it.",
"I'm not suggesting you actually do this, but this is how you *could* do it: Put a stick in the ground, face north, and measure the angle of the sticks shadow from north, at a particular time. The next day, travel a few miles south, and repeat the same procedure, at the same time. There will be a difference in the angles, and after a bit of thinking you realise that that could only happen on a curved surface, not a flat one. That's how they did it about 2500 years ago."
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5uur0m | how do people lose their accents when they sing? | Repost | explainlikeimfive | {
"a_id": [
"ddx0bk6"
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"text": [
"First, nobody doesn't have an accent. A Midwestern American is what we think of when we hear 'no accent' but really everyone has one. Second, they don't lose their accent when they sing. It's really no different than you singing I'm Gonna Be by the proclaimers; you just adapt your singing to what they sound like. Sometimes it's a bit harder, like going from an American rolling 'r' sound that's made by 'oscillating' the end of your tongue (I can't think of a word) to something more like a French 'r' that's made in your throat. I hope this helps!"
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5uwqzf | Why do people think the earth is flat? Even people with easy access to internet and information | Repost | explainlikeimfive | {
"a_id": [
"ddxgz53"
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"text": [
"Some people are distrustful of authority for a variety of reasons. Predictably, the \"bad authorities\" are usually government, law enforcement, or schoolteachers. However, the distrust can extend to scientists, statisticians, historical records, and other sources of information that support the teachings/laws/policy used by those \"bad authorities\". When these people learn that the world was thought to be flat *until scientists figured out that it was round* they immediately believe that those scientists and/or this history book are lying, and that the people who thought it was flat (before the scientists/historians interfered) must have been correct. The roots of this distrust often come from religion, which can teach information that contradicts scientific evidence. This forces followers to \"pick sides\" and sometimes view scientists as untrustworthy or as liars. When it gets to the point where somebody thinks the Earth is flat, with obvious physical and theoretical proof otherwise, it would usually be classified as a mental illness. Particularly diseases which cause paranoia would be involved."
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