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6rm1ak | Why are Americans so in love with the Flag and their military? | Repost | explainlikeimfive | {
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"It's a pretty decent flag. Aesthetically pleasing color combination, and the design is a bit more exciting than a combination of stripes, but still clean and simple. 10/10, would represent 50 states and 13 original colonies again.",
"It is just part of American culture. You could ask the same question of why the English are so attached to their monarchy. The US was founded in a relatively unique way and that leads a great many Americans to believe that our country has a unique role in the world. Many are exceptionally proud of that fact, and the subsequent international strength that they believe it allowed for, so they are proud of the objects and organizations that symbolize that exceptionalism."
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6rmxd9 | How can so many mobile games get away with clearly ripping off copyrighted material? | Repost | explainlikeimfive | {
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"Games are expensive to make, taking lots of time and money. Good games take more time and money. In the mobile gaming world, I make more money when more people download my game, and I lose money in making the game. Stealing intellectual property from other people and well-recognized brands kills an entire flock of birds with one stone. Now I can get lots of people to download my game because of the brand recognition. I don't have to waste my time and/or money developing assets on my own. I don't need to spend lots of time hoping for my brand to get big. I can just sit back while the money rolls in. On the other side of the house, we have the people who made these brands or assets. They can come after me if they want to stop me from using their work for my benefit, but it costs money to do this. If they are a huge operation and I'm one person, it's probably going to cost them more money to take me down than for them to just ignore me. I'm also not the only one stealing from them. They have tons of little leeches like me doing the same thing. It isn't worth their time to go after all of us, so they focus on the biggest and most egregious ones until it stops being worthwhile. If they do come after me, so what? I take that one app down and put up another one ripping off someone else and carry on my merry way. Rinse and repeat if necessary. If they manage to take my entire company down, I'll just open another business and do the same thing again.",
"To be honest, there isn't much regulation in mobile apps, especially on the Google Play store. Even more so when the apps originate in countries with loose intellectual property laws (like China)",
"Without having an example, I can only really speculate, but it usually comes down to two things: 1) The mobile game is too small for the copyright holder to notice/care about going after. 2) The mobile game is already licensing the copyright material. EDIT: /u/Rpgwaiter deserves credit for this, but the point of countries with loose/non-existant IP laws (with China being an infamous example) is another big point.",
"As an aside tho the creators of league of legends, riot games I believe is going after mobile game makers that are ripping off their content.",
"Well kinda depends which games. There are actually assembly kits for games now that will run off similar templates and wouldn't be copywriting each other since were developed with the same game kit. So many of the 'city/town' builders come from that."
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6rmxrl | Why can't we remember the earliest stages of our lives? | Repost | explainlikeimfive | {
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"In general, the childhood amnesia happens because at early ages the areas and structures of the brain responsible for the proper register of memory (and other cognitive abilities, as language) aren’t developed enough, registering memories in a simple way. As we grow up, the register of memories gets more complex, and we forget a lot of things to make room for another memories. Also, after 7-10 years old, we tend to organize the events of life in a timeline, which can cause some confusion about when exactly some facts of the past really happened. Of course, depending of the importance or the frequency of an event, the memory can persist."
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6ro2b5 | Why is it acceptable for men to show their nipples in public/media but not women? | Repost | explainlikeimfive | {
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"Sexual subzones. A woman's chest area is biologically developed to show sexual development in tandem with other features. Males are biologically attracted to females who are on the prime of sexual development. So sexual zones are linked to sexual arousal. Men's chest area dont do anything i know of that comes close to boobs.",
"Because much of our western law is written by Christians trying to force their religious values down everyone else's throats. They sexualize everything and think it is dirty.",
"I know there are people out there blaming things like culture or religion, but that's not entirely it. The main thing is that women's breasts generally are much more sensitive then a man's, this was used since ancient times as a part of sexual acts. So over the years, a woman's breasts became associated with sex. A man's nipples weren't used hardly as much and never had the chance to be associated with sex. So basically a woman's breasts has become sexualized with a perfectly valid reason over a man's nipple",
"Female breasts are secondary sexual characteristics, male breast are not. In many societies, displaying both secondary and primary sexual characteristics is considered obscene. Secondary sexual characteristics being things that develop/appear during puberty, eg. breasts, wider hips, pubic hair, etc."
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6roka4 | Why is everyone that pleads "not guilty" in a court case, but later found guilty, not also given a perjury charge (along with their initial charges)? | Repost | explainlikeimfive | {
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"> Why is everyone that pleads \"not guilty\" in a court case, but later found guilty, not also given a perjury charge (along with their initial charges)? A plea is not sworn testimony from the defendant, it is just the demand of \"prove it\" to the prosecution. Also it would act to derail the intended operation of the legal process; if you are going to be charged with perjury if you lose then why not lie your ass off at every opportunity? If you win you get off and if you lose you are going to be convicted of perjury for defending yourself anyway. And that is what it really comes down to: You have a *right to a legal defense*. To charge you with perjury just for pleading not guilty would violate your fundamental right to legal defense and would be a violation of human rights. You gotta' watch out for those.",
"\"Not guilty\" doesn't necessarily mean \"I didn't do it.\" Sometimes the defendant may be arguing that although they did the deed, the act itself was not a crime. I killed him, but it was self defense. I took the money, but it was mine to begin with. My brain tumor impaired my judgement. I was following orders.",
"In the US you aren't required to incriminate yourself; it's the prosecutor's job to prove you are guilty. You have an initial arraignment, at which the charges against you are established, your rights are explained to you, and you submit your plea. If you say you are guilty, the case goes straight to sentencing. If you say you are not guilty, you get your day in court. A 'guilty' plea doesn't necessarily mean you are guilty; it means you accept the fact that the prosecutors *do* have enough evidence to convince a jury that you are guilty. A 'not guilty' plea doesn't necessarily mean you are not guilty; it means you *do not* accept the fact that the prosecutors will be able to convince a jury that you did everything you are accused of. Since there is often a laundry-list of charges sought against you, 'not guilty' might just mean that you don't believe that they will be able to make some *specific* charge stick, even if you are found guilty of the rest of the charges. If you plead guilty at the arraignment, you are accepting everything you are charged with up-front as a package deal. So if you think that while you are technically guilty of breaking the law there are extenuating circumstances, and believe that a jury will agree with you, you plead not guilty and go to trial. If you hope to work out some sort of plea agreement, you plead not guilty and you go to trial. If you are totally guilty and you hope to weasel out of it, you plead not guilty and you go to trial. Pleading guilty, you're up against established sentencing guidelines and whatever mood the judge is in; pleading not guilty, you're (probably) up against a jury of your peers. All of that said, if you plead not guilty and it turns out to be a complete waste of the court's time because everything but your plea shows that you really *are* guilty, the judge can and sometimes will punish you for that. But (in our system) on its own pleading 'not guilty' is not perjuring yourself, because you are not legally required to help them prosecute you.",
"Just to add on to what was already said here, a charge of purgery would require a completely separate trial as its not the same as what ever you were charged with and can't you can't be charged with it before its happened (charges have to be filed before the trial starts). It would basically double court proceedings of guilty people for little to no real gain to the public interest.",
"Pleading Not Guilty doesn't mean \"I didn't do it\". It means (in effect) \"I am exercising my right to presumed innocence, and am requiring the prosecution to prove their case against me beyond reasonable doubt\". So there's nothing that is a 'lie' about that.",
"Don't know about the US, but in Sweden the defendant is explicitly never under oath. Even when testifying. You can lie about the colour of the sky and it's not illegal.",
"One reason: The initial not guilty plea is entered at the very beginning of a case - sometimes in the same court appearance when a defendant is assigned their court appointed lawyer. It is not advisable to do much of anything in court without talking to a lawyer. It is very common for defendants to appear and be told by a public defender on duty that everyone gets a not guilty plea at the beginning because that first hearing is just the beginning for potentially dozens of people. Getting into a back and forth with the prosecutor and the judge at such an early stage a) risks tactical errors by defendants who haven't talked to a lawyer yet and b) would take forever in cities and medium to large towns. If you're curious, go sit in your county's arraignment court for an afternoon then chat with the clerk. It'll be eye opening. Practices vary from place to place so don't assume it's the same in New Mexico as it is in New Jersey, but you'll leave way more informed about our criminal system. Perhaps obvious disclaimer: This answer centers on USA law only."
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6rqx2y | How does WiFi work? | Repost | explainlikeimfive | {
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"A signal from your Internet Service Provider (ISP) comes into your house, through your modem and into your router. The router converts this signal into a Wireless broadcast (radio waves, but at a different frequency than the one your car picks up for music) which can be picked up by the hardware on your computer and is converted back into a useable format. Your computer then does the same in reverse. Data coming in and going out. Traditional wires are simply replaced by a signal in the air. Wi-Fi is also different from many other forms of radio frequency in that its range it's rather small. Typically no larger than the size of the average house."
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6rtv3g | How can video games be played from a cassette tape? | I'm talking about old 80s and 90s computers that played games (and possibly run other programs I guess) via tapes that looked like audio cassette tapes. How does that work? If you want to listen to an audio tape from the start you have to rewind it, not so if you lose a game on a tape and have to restart it. | Repost | explainlikeimfive | {
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"The cassette tapes were used for data storage. Just as you can have data CD's, and music CD's. The tapes were played and the data input into the computer's RAM. No game data was stored on the computer's tape itself. Data loaded much more slowly than happens now. But a program could be saved. There were no CDs, DVD, thumb drives, or any other storage devices. No Internet or cloud.",
"Cassette tapes were used to store computer programs, but they weren't run straight from tape. You would first rewind the tape to the beginning, tell the computer to load the program, then start the tape. The computer would simply read the data from the tape and store it in its RAM; and this would be the complete program -- if a game, it would be all the levels and everything. Once the program had been completely loaded, you'd switch off the cassette player and instruct the computer to run the program. And to do that, the computer wouldn't need to read any extra data. Everything it needed was already loaded in its RAM. If you lost, no problem: the program would ask you if you wanted to try again, and if you did the program would simply loop back to near the beginning and run again. A simple program written in BASIC, for example, might include something like: 9960 INPUT \"Enter Y to play again. \"; x$ 9970 IF x$=\"Y\" OR x$=\"y\" GOTO 100 Of course, commercial games would normally be written in machine code, not BASIC, but you get the general idea: simply loop back to the beginning of the game. (Or near the beginning.) Bear in mind that these games were very simple -- a home computer in those days might have something like 64 kilobytes of RAM in total. Maybe 128. There wouldn't normally be many levels, and a good player ought to be able to complete them all in one session (eventually). Obviously, compared with today's games, there were drawbacks. You couldn't save the state of play at any point: if you loaded another program or switched off the computer (or even if the power supply glitched for a split second), the game would be deleted from RAM and the next time you played it, you'd start from scratch. It was floppy disks that made it possible to save high scores and other data in order to save state.",
"They work the same way as floppy disks later and hard drives now: There is a file at the beginning that says what files are where. The computer had enough memory (what you would call RAM today) to do all the work."
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6rujiz | How do tides work? If it's high tide one place in the world and low tide somewhere else does that mean sea levels are uneven? | Repost | explainlikeimfive | {
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"[This one has been asked before]( URL_0 ). TL:DR the moon pulls the water around making the sea-levels uneven. I haven't seen it in a while so i won't remove this one under rule #7."
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6rxrc5 | How can a fan cool me off if the air it's blowing is the same temperature as the room? | Repost | explainlikeimfive | {
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"If there's no breeze, the air immediately next to your skin quickly gets warmed up to nearly body temperature- and if you're sweating, quickly becomes saturated with evaporated water, and can't absorb any more. But if there's a fan on, the air is constantly being mixed, and there's always fresh air (at whatever temperature and humidity the room at large has) next to your skin. This is sort of the opposite of how a blanket or coat or other insulating garment works, by trapping the same (almost-body-temperature) air near your body, reducing the amount of heat that's transferred from your body to the environment.",
"The air next your skin heats up quickly and will get close to body temp creating a pocket of air around you that you can no longer dump body heat into if it is still. The breeze disrupts said pocket of hot air and move cooler air in next to your skin, cooking you down."
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6s0cgc | if borders between countries/states aren't straight lines, and aren't defined by rivers, then how are they defined? | Repost | explainlikeimfive | {
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"There are a lot of ways to draw borders. One of them is to draw a straight, flat line. One is to follow a river. Another is to follow a high mountain range, where the border is placed on the contours of mountains, like you see in Northern Italy. For these, often times the whole range will belong to one country, or the line will snake between the peaks. Rivers are just one of a suite of natural boundaries that might create a border. Another is to follow ethnic, linguistic, or religious ties, marking individual townships as either one side or the other. You see this a lot in areas like Europe where borders have been defined by religious or ethnic warfare, and you see borders that snake around to keep communities to their own side. Lastly, borders sometimes form around actual positions surrounding a ceasefire or peace agreement. Whatever territories each army presently controls become parts of their countries, and it's left as that. You see that a lot in areas with very intense violence between factions that strongly distrust one another and view any kind of treaty as a betrayal of their principles, such as Israel/Palestine."
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6s1tut | In English, what is the rule for the use of “An” or “A” | Repost | explainlikeimfive | {
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"An is used for words that start with a vowel sound. Examples, An owl, an hour, an eight, an apple, an onion. A is used for all others.",
"It has nothing to do with meaning. It has to do with how the word sounds. If a word starts with a vowel sound, you use 'an', otherwise, you use 'a'. Note this is how the word sounds, not how it's spelled. 'Unicorn' starts with a y sound, so you say 'a unicorn'. The h in 'honor' is silent, so you say 'an honor'."
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6s2qzu | How did Salt and Pepper become the chosen ones of food spices? | Repost | explainlikeimfive | {
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"No it's way more interesting. Salt preserves food (by drying it) and is readily attainable (from the sea). Pepper preserves meat (piperine kills bacteria and repels maggots but is harmless to humans). Over time, cultures that embraced preservatives like this prospered and their cuisine spread. In India, they use a whole different set of spices. In China, there are even two different words for spices called La and Ma (edit see below). One is fiery like capsaicin and the other, referring to Szechuan pepper corn, is electric like a battery on your tongue. It's amazing. **Edit:** side note: people seem really curious about Szechuan peppercorn. It actually used to be illegal in the US but [as of 2005 you can now buy it]( URL_0 ) The reason salt and pepper came to grace restaurant tables with all those other spices out there is **French cooking and Louis XIV. ** At the time that formal dining came into fashion, French culture was influential throughout the western world. Louis XIV was an influential man as the king of France. He didn't like as much salt or pepper in his food but others did so he created the custom of having his chefs put it on the table rather than cooked in. The custom spread and western culture helped spread it all over the world. Edit: black pepper contains piperine not capsaicin. Edit 2: Chinese is hard. La (not Lada) and Ma are more nuanced and appear to refer to different things. La is the word spicy generically. And by region (Hunan vs Szechuan) Ma la refers to the numbing spice (that I described as electric feeling) see the comments below for detail.",
"To add something slightly different to most posts I want to mention our nervous system, which works using salt (sodium ions). [Your taste buds are more receptive]( URL_0 ) in the presence of salt. Because of this, if you use a suitable amount of salt you can enhance the taste of almost any food. Be aware though, if you regularly use a lot of salt (but not so much to make the food taste disgusting) when you return to eating food with less salt it may appear to taste worse. As such, this 'enhance all taste' property of salt is desirable for the dinner table.",
"Others have answered this question pretty well, but consider reading At Home by Bill Bryson; it's all about the modern home and goes into loads of detail about the history of apparently mundane things including why we have salt and pepper. It's also genuinely a funny read.",
"Salt is an essential electrolyte. We need to have regular intake, just like other animals that will seek out salt licks, etc. If we don't have enough salt, or replenish it at regular enough intervals, cramps and other signaling/electrolyte problems will arise. For the same reason, we have evolved taste receptors that make any food with salt in it \"taste\" better to us. Pepper aids in digestion and pepperin, a component of pepper, helps the intestines uptake nutrients. So it's a co-factor in our getting better nutrients in our diet. For the same reason, it tastes good to us (much of our sense of taste has evolved around things we need). Things that we need to intake almost daily and/or with virtually every meal, are integrated into our sense of taste as seeming to complement everything rather than fundamentally altering the flavor profiles of foods. These things are known as seasonings, rather than spices.",
"I remember reading the correct answer to this about 6 months ago. Hold my beer while I butcher it. Salt suppresses bitter tastes/unpleasant flavours in a lot (all?) foods. Which gives a more balanced flavour which humans like. You can add a small amount to coffee beans that are a bit old to negate the \"old and bitter\" flavour coffee gets later on. Given the choice, we'll tolerate something that's too salty over something that's too bitter. Pepper has crude antibacterial properties that humans can also tolerate/consume (there are other things that are anti bacterial but also anti-human).",
"What about ketchup and mustard? I've done a lot of searching and can't find out where or why or when!",
"It is not the case everywhere. I found out in Hungary that they use paprika for just about every food. It tastes good.",
"Salt is a necessity. Our bodies require a certain amount of salt. Salt in high concentrations and peppers of various sorts are great for killing bacteria, and keeping food safe for longer periods of time.",
"Mainly because of 3 reasons. * 1) Salt and Pepper are both fairly ubiquitous, being among some of the most abundant resources known to man. Salt, makes up much of our water, and is easy to de-salinate from water and then use, or mine from vast salt mines. Pepper, in it's various forms and incarnations, is fairly robust a plant and has many varieties that make them easily grown in most climates without many issues. * 2) They are some of the best spices known. Salt and pepper usually take very little to alter flavors of the food they are added to. Salt is usually tastable by humans by as little as 1 part per 1 million, and pepper at the most mild of capsacin levels can be tasted at around 1 part per 10,000. Both spices can be used at relatively small quantities that provide significant effects on the food it's used on. * 3) Mainly salt on it's ability to perserve foods. Salt has been used for millenia to dry and perserve foods. Running pepper in with it helps add flavoring to an otherwise VERY salty piece of meat once it's treated and produced.",
"This has probably already been mentioned by those more eloquent than I, but we use to fight wars [over Salt as well]( URL_0 ). As already mentioned, because salt is used as a preservative, ships at the time would heavily salt all their food as they went on their months/years long trips discovering new parts of the world. Obviously with a lot of European countries basically travelling the same routes, there would be fights over the best spots to hold and restock their salt and other produce. Now, we don't have that much of an issue instead we have [Monte Kali]( URL_1 ) in Germany which is a literal mountain of salt which gets added to daily. The downside being the salt has now seeped into the earth and ruined the soil underneath. Quick aside, all of this was written off the top of my head from what I remember. If people wish to correct me or add to this, please do. Never thought I'd say this, but salt is super interesting.",
"Mobile formatting ect All credit to /u/Flubb Reposted from [here]( URL_0 ) It got 'common' by desire for it. If you mean 'common' by quantity, that's to do with trade routes opening up. The Romans started it off - the sole Roman cookbook, purported to be written by Apicius, calls for pepper in 80% of the recipes, and Pliny the Elder moans about why pepper should excite so much enthusiasm amongst his contemporaries, considering that it cost so much to bring it from the East. On to the mediaeval period, pepper served a number of uses, including humoural - some foods were considered dangerous (eels for example, because they look like snakes) and so you needed to counter-balance or offset humours in food with spices - pepper being a hot, dry humour. They were also used in almost every dish concocted and therefore demand drove the spice trade. Related to this, spices in general were also used as medicine - I can't find much on pepper as medicine, but it was used to stifle a cold (being hot). There's also the allure of spices: spices were generally associated with Paradise - or being close to it - Prester John's land was supposed to have forests of pepper, which was only 3 days journey from paradise. As for the amount of pepper, that comes through the spice trade. Because generally it came from the Far East it cost an awful lot originally, but even that was dependant on the levels of import - some years it could cost you a lot of money (163 Gold dinars in Alexandria in 1333 for 500lbs), some years it would drop precipitously (11 years later in Alexandria, it had dropped to 75 dinars per 500lbs). As trade opened up with the East, pepper imports grew - during the 15th century, Venetian merchants brought in an average of 400 tonnes of pepper from Alexandria. Once the route to India had been discovered by the Portuguese, this only increased - one estimate of 4 Venetian galleys brought in 4 million pounds of spices (not all of it pepper), and another convey the following year brought in 2 million pounds, pepper making up about 1/2 of that amount. As pepper was generally in the hands of the Portuguese (and later the Dutch), they had a habit of raising the prices - and by the 1500s, pepper was an every commodity that you couldn't do without - this is why Queen Elizabeth I was so interested to support expeditions to find pepper.",
"Piperine in large doses boosts the absorbtion rates of other vitamins(and drugs😬) aswell. I read somewhere it boosts the absorbtion rate of curcumin up to 2000% 😳",
"I'd like to add that both help you taste your food by stimulating salivation which helps your taste buds actually tell what they're tasting. source: I cook for a living",
"They didn't really, only in the west and only in countries culturally close to France. The east and the americas had there own spices. That being said salt and pepper are as popular as they are for three main reasons: mild taste/availability, usefulness as a preservative and lastly it was popularized by one of the later King louie of France. Either XIV or XVI. Whichever was sun king.",
"Classic situation of big salt and big pepper working together to force out all the other spices in the pantry.",
"Salary comes from the Latin word salarium, which also means \"salary\" and has the root sal, or \"salt.\" In ancient Rome, it specifically meant the amount of money allotted to a Roman soldier to buy salt, which was an expensive but essential commodity.",
"Salt is necessary for survival. There's a reason why we've evolved to crave the taste of salt, sugar, and fat, because not having them at all is really bad. I have no idea why pepper is so common.",
"Salt is special because the sodium and chlorine ions that we get from it are critical to our nervous system. If you don't eat enough chlorine and sodium you will eventually *die*; and since salt is the most plentiful (and edible) source of those elements on the planet our taste buds have evolved to crave it. Pepper appears to be popular for cultural reasons. My understanding is that it's a 'clean' spice which can add heat to foods without adding all sorts of other flavours. It does have bactericidal properties, but so do almost all other herbs and spices so I doubt that has much to do with it's prevalence.",
"The real question is: How did they have a child and why did it come out as Paprika?",
"Two nubian priestesses traveled to Egypt's old kingdom capital of Memphis and preached at length about those particular spices.",
"Salt is one of the fundamental tastes detected by the tongue. The only recipes you'll find where you don't add salt are ones that are already salty. Salt is kind of the fundamental thing to add in order to bring out flavour. Pepper is 'hot', but doesn't have much of an actual flavour, so it doesn't clash with as many other flavours. Thus it is more versatile than many other spices."
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6s5izq | Why is it a negative thing to be over-qualified for a job? | Repost | explainlikeimfive | {
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"If you're overqualified for a job, there's a good chance you'll leave when something better comes along. Employers prefer stability, particularly because some jobs have a cap on how high a person can perform.",
"Let's put it like this, if you are over-qualified, it would be a waste of your knowledge having you in a lower position. Also your demands on salary are probably higher than what's offered for the position.",
"It means that you are more likely to be unsatisfied with your job and seek employment elsewhere. It also means you are likely to find said employment. Your skills have marked you as a temporary worker and many places are not willing to put in the time and effort to train you if you are not going to stay.",
"Hiring someone is a huge pain in the ass. You need to advertise, sort through a shitload of resumes, interview and then make a decision. Once you hire someone it takes weeks/months to get them accustomed to the position and sometimes even a year before you'll turn a profit on that employee (depending on industry and position). Also, there's often investment in training that needs to be made. So overall going through this process only to have the employee leave or not work out is a huge headache and can cost a lot of money. For a smaller company making a single bad hire can kill their profit for the year. So hiring is one of the biggest choices a manager makes, and it comes with risks. The overall hiring process is targeted to minimize those risks. You want someone qualified, sure, but also someone who can manage the required interpersonal relationships. Someone who won't disrupt the team dynamic. And lastly, someone who will stick around after you've put all this investment into hiring them. It's that last part managers are worries about with over qualified people. They know there's a good chance you'll leave and they'll have to do the whole hiring process all over again. This would be quite the loss and an overall pain in the ass that they'd rather avoid."
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6s6pe9 | What makes our bodies twitch right before we fall asleep? | Repost | explainlikeimfive | {
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"It's called a myoclonic jerk and it's caused by your two nervous systems (yes... You have 2- one you control, like your legs; and one you don't, like your heart) realigning to night time mode that allows you to dream of running without actually running.",
"Hypnic jerk (sp?) Basically the mechanism that tells your body it's about to fall off of a tree branch and get devoured by hungry lions, tigers, bears, etc. waiting below."
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6s841b | Why were Native Americans so far behind Europeans technologically and culturally? | Repost | explainlikeimfive | {
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"This is a really fascinating question. There's a book I highly recommend reading that discusses this very topic, called \"Guns, Germs, and Steel\" by Jared Diamond. For the sake of answering your question, here's a couple of the reasons the book posits. First and foremost, the relative ease of domesticating wheat compared to maize. The type of wheat that was grown by early civilizations was genetically almost identical to wild wheat. Maize required extensive artificial selection to become even the rather mundane crop that it was when Europeans arrived in the Americas. Wheat could also spread equatorially, which means fewer adaptations were required for surviving in different climates. Maize was domesticated in South America, had to adapt to survive the much hotter Central Americas, and then adapt again to survive the cooler North America. Early human's artificial selection to make maize a proper cereal crop took millenia, whereas domestication of wheat occurred quickly. Wheat also has a lot more protein in it than maize, which means it requires less supplement from other foods. All this stuff seems little, but the presence of a robust and nourishing cereal crop was one of the foundations of every early civilization. Settling down means you can't forage, and providing surplus food allows for people to specialize in things like \"making tools\" or \"writing things down\" instead of hunting all the time. These advances occasionally lead to improved farming techniques, and consequently a larger food surplus. The lack of domesticated animals in the New World was also likely a contributor. Humans brought protodogs over the land bridge from Russia during the last ice age, but by then we were already superpredators. Almost every large land mammal that existed in the Americas was extinct within a few thousand years (bison and llamas being two of very few exceptions). Species like horses, pigs, cows, and sheep had evolved alongside humans and had developed means of avoidance or cooperation. The humans that migrated to the Americas were almost like an invasive species. Of the few large animals that the Native Americans left alive, only one ever was domesticated, the llama, and its use was quite isolated. Domesticated animals (especially the horse and cow) allowed Eurasian civilizations to benefit from nonhuman labor, pulling plows, turning mills, all work that is backbreaking for humans and... somewhat less so for other animals (I'm not going to pretend that humans were nice to these animals, but having four legs is an advantage in pure traction). Living in close proximity to such a diverse group of animals also bred powerful new diseases. Tuberculosis, for example, is believed to have jumped to humans from animals. These diseases grew more powerful in the many densely-packed cities that formed in Eurasia, and ravaged the defenseless Native Americans when the two cultures met. These advantages basically gave Eurasian people a couple thousand years or so head start, and as I mentioned before, the production of surplus food allows specialization and technological innovation, which often compounds the surplus and drives further growth. But I do highly recommend that book if you're interested in the development of ancient cultures.",
"The Inca were not aware of the Aztec, and the Aztec had little contact with the plains Indians. The plains Indians had little contact with Inuit tribes. The north-south orientation of the landmass meant that technology developed by one nation would take many centuries to disseminate because travel was so difficult. Jungle empires can't cross the desert, and desert tribes can't cross the jungle. In Eurasia, you can stick to a single climate band from Madrid to Seoul. The Romans knew of the Chinese and sporadically traded with them, allowing technology to spread quickly across nations.",
"How were they culturally behind? How can one even make the distinction between superior and inferior culture?",
"I just want to add to what other people said. An interesting geographic aspect of Europe is that it is separated by small - but passable barriers. England is separated from Europe by a channel - not an ocean. Italy is separated from Europe by the Alps, but not the Himalayas. This led Europeans to split into slightly isolated countries. They were separated from each other - but not enough to prevent trade or war. So you ended up with a pretty much constant state of trade and war. Both of those things lead to technological innovations. To put it another way - if Europe was one big plain with no rivers or seas separating it into different countries - it probably would have been ruled as one Empire for thousands of years without splitting and fighting, and technology would have stagnated.",
"Culture is not something that can be measured by a specific metric. There is no way of showing that native Americans were culturally behind. As for technologically, there were many large cities of indigenous people across the Americas. In fact the Native Americans were the ones who taught the Europeans how to properly rotate crops, and how to ensure they would have food for the winter. So the short answer is they weren't. They were more advanced in several fields, their lifestyle however was more intune with living in concert with nature instead of destroying it. As a further aside, when Europeans reached the Americas, the indigenous people had just been ravaged by a plague that wiped out 70-90% of the population. Frankly we are still trying to piece together what life was like before the Europeans got here.",
"Culturally they weren't behind. Cultures evolve to fit a people in a particular environment. As for technology it depends on what areas you are speaking of. Native Americans mastered the art of medicine and human biology. Indigenous pharmacology was the most advanced in the world, with alkaloids such as quinine well known by Native South Americans ahead of Europeans or other nations. Only 60 members of the original 500 survived in the Jamestown colony. Most had died of scurvy and the rest were dying. When the local tribe saw their condition they immediately recognized it and treated those still alive with tea made from green pine needles. This cured them of the scurvy. Scurvy is caused by a lack of vitamin C and pine needles are a great source of vitamin C. Scurvy was also the bane of sailors costing many lives. The only food that could be preserved on a ship was salted meat and a hardtack type bread. After word of the Jamestown miracle Europeans started to figure out what the problem was. All ship started carrying limes on them. That's when the British sailors earned the nickname \"limeys.\" And to this day they still carry the nickname. As for agriculture Native Americans were far more advanced than Europeans. In the the Andes of South America the natives had almost 3,000 separate types of potatoes with different features and that grew at different elevations. Native Americans gave us corn, beans, potatoes, tomatoes, and peppers; in terms of how the food is grown, produced, and preserved; and in terms of the culinary arts. A really good book on what the rest of the world acquired from Native Americans. The title is \"Indian Givers\". It list and explains what every group contributed to the world. The list is very long with things like chewing gum, rubber, and even what they contributed to the Industrial Revolution. Here's the Wiki article on the book: [Indian Givers: How the Indians of the Americas Transformed the World]( URL_0 )",
"Because 90% of the human population lived on the other landmass. Europe, Asia, and Africa had always been interconnected. With 90% of the population on that one great interconnected series of continents, it's no wonder that the most development happened there. Really, given that people on both landmasses started out as hunter-gatherers, as all humans had been for 95% of our history, I think it's pretty amazing that agriculture and civilization arose in the Americas in a completely independent event from its rise in Euraisa.",
"This is a eurocentric way of thinking. Native Americans valued technology differently than Europeans. Europeans have been historically willing to destroy their own environment in the pursuit immediate returns in economics and technology. Native American (who are and were a disparate group of varied cultures, not the single, one-dimensional group they are often made out to be), did in fact, use technology that was relevaant and useful to them and early europeans invaders benefitted from it in their invasion. However, Native American culture tended to be more forward-thinking, considering the long-term consequences of actions. The cultural superiority of Europeans is based on Europeans valuing their own culture more highly, conveniently forgetting the Native American source for some pretty major facets of modern culture (like the Federal system of democracy), and the later loss of Native American culture following European-caused disease, relocation, and systematic suppression. You can easily find a huge list of Native american contributions in Wikipedia, [here]( URL_0 )",
"Paraphrasing CPG Grey: Animals. \"What?\" Yeah, animals. Domesticated livestock animals.* Apparently not having tons of free, manageable food and extra labor does a lot to harm a civilization's productivity. Anything that would have gone to research and war went directly to food, so they were super far behind. By extension the lack of farm animals filling cities with feces and generally being smelly and gross left the Americas bereft of their own fatal diseases, meaning that without extra food, labor, and contamination, they were both biologically and technologically vulnerable. The diseases were killing way, way before the European Invaders ever even had to lift a musket barrel. Edit*",
"I suggest you re-ask this question in r/AskHistorians This sub has too many folks talking out of their butts about stuff they don't know anything about, or seeing needless offense in your question. The short, short summary I will give you is that European technology was a result of building off technology that came from many different cultures from not just Europe, but Africa, Middle East and Asia. There was constant trade from the dawn of human history that resulted in a lot of technological breakthroughs. You had tons of cultures sharing technological secrets and just building up and up. The Native Americans were completely cut off from these achievements, such as the major achievements made in metallurgy and the sciences. While some south american tribes did have metallurgy techniques like smelting and molding, it wasn't anywhere near as advanced as what was developed on the other continent, and they remained isolated from the tribes in the northern continent. For technology to prosper requires trade, and the development of long distance trade routes seen among Europeans, Easterners, Africans and Asians never occurred in the Americas until the Europeans came over and created it.",
"If you're thinking about basic elements like the invention of the wheel, is seen in Aztec toys. They didn't use it for transportation because the terrain didn't allow it. They were also at a disadvantage when traveling long distances because they didn't have horses, which hinders cultural exchange. In Europe it was very easy just to start riding a horse and end up in Mongolia.",
"In one word: Commerce. But it gets more complex when talking about cultural advancements. Here comes an expample. The Gunpowder was invented in China and came to Europe through the Silk Road. In this way, you get rid of the necessity of Europeans to dicovery the gundpowder for themselves. Edit: changed discovered to invented.",
"If you think of \"advanced\" as having coats and ships then you have a very narrow way of thinking. You're talking about groups of people living in VERY different worlds. Yeah your European dude had a ship, but he couldn't survive for months at a time in the wilderness. He didn't have the same traditional healing methods passed down. Not all Natives died the second they got sick (until they were exposed to that which they had no immunity to). They had their own ways to treat illness. They survived from the land, and they fought and won battles. You can't even compare the two. It's like comparing a bicycle to a hairdryer.",
"I can't see any particular linearity that represents cultural and technological superiority. Europeans were nasty and smelly and good at sticking sharp things in people. Could build ships and so on. But they didn't have the geometry of the ancient Egyptians etc. Cultures in the Americas had very large cities with all kinds of nice features. Just a different thing going on. Mostly dead when explorers from the European invasion came through. Europeans sent waves of death ahead, clearing the country. We've also in the US been misled about the original cultures as part of the whole \"manifest destiny\" thing. Make the savages into real people who had cities and nations rise and fall, it becomes much more ethically difficult to push them aside. I can't see any reason to pick one time period to compare. Just coincidence what was what on each side. Civilizations rose and fell in both domains.",
"This is a loaded question. As you can expect, there are many reasons, some of which are still being debated. One main thing to remember about the Native Americans is that they, until the first Europeans began to come (1500s ish?) and interact with them, didn't have any contact with the the rest of the world. Contact between Asia and Europe and even Africa spread many cultural ideas and innovations. The native Americans didn't have the Silk Road. Simply put, it's hard to be as advanced as the rest of the world when you're working all by yourself. Why didn't the inuits in the north trade and diffuse \"advancement\" with the Iroquois in modern New York, or with the Incans and Mayans? An [interesting (and probably true)]( URL_0 ) theory is that this is due to the axis of the americas versus the axis of the rest of the world. Throughout the rest of the world, people spread and migrate easily because they generally are moving on an east to west axis with much less change in latitude. The Americas are relatively narrow in comparison to the \"Old World,\" and most \"spreading out\" would be done on a north-south axis. This is MUCH harder to do on a large, noticeable scale because different latitudes come with different temperatures, climates, etc. People in modern day New Mexico did not have the necessities to travel to modern day Alaska, and vice versa. It's important also to note that while the native Americans as a whole weren't as \"advanced\" as the rest of the world, certain societies (specifically the Incas and Aztecs) built massive and advanced cultures and civilizations that awed even the Spanish conquistadors. Edit: I'm so happy that everyone is mentioning Guns, Germs, and Steel by Jared Diamond. This is truly a great book that broadens your world view!!",
"Disclaimer: I'm not an expert I think if there is an anwser to that exponential growth plays a big role in it. A few hundred or even thousand years are not all that much time. A human life span is ca. 80 years so year 0 lies just 25 human lifes in the past. It's crazy if you view it like that. Most of our civilized history spans across just 150 human lifes (12k years). Now if you think about how quickly technology can develop once it spontaneously emerges it's quite obvious that there have to be major differences between cultures on earth. Especially when there is no real communication as there is today. If someone develops a new app pretty much the whole globe has access to it at the same time. Who ever developed the wood app called \"wheel\" first probably had a major advantage over all others on the planet for many years or decades if not centuries. During that time new technologies emerged faster because you could now bring food to the table more quickly and work on new crazy things more often. Technology grows exponentially because development accelerates new development. Like that small differences in the beginning lead to very big advantages in the future. You can compare it with today aswell. Who ever will develop a strong A.I. (artificial intelligence outperforming the human) first will be able to develop things humans could not develop without it sooner. It's like the wheel 2.0. or maybe 3.0. I believe 2.0 was the computer. Anyhow, important to note is who ever will get strong A.I. first would be like the europeans back then while the others would take the role of native americans. Unless we share our progress with everyone which is what OpenAI is all about I think. So I'm quite positive about the future but I'm not sure if that is a good answer to your question.",
"If technology means to be ahead, what does it mean now that people are actively choosing to use technology less? Does it mean we've regressed or have we evolved as a society? And what does it mean to be culturally behind or ahead?",
"Consider the kind of tehnologies where Native Americans were obviously ahead of Europeans: canoes, winter clothing - versus the kind of technologies that Europeans were obviously better at - weaponry, cavelry. Native Americans dedicated their technology to survival; Europeans dedicated it to conquest. It's also worth bearing in mind the kind of associations between Native American belief and the natural world, versus the kind of attitude a European might have had; if you can choose between a massive, polluting factory that produces luxury goods, and a sustainable society that puts limits on what you're able to produce, then the kind of choices made would reflect on that society. I also get the impression that Northern North America was mostly populated by nomadic societies and therefore didn't stay in one place to build towns in the way Central Americans, Asians and Europeans did."
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6s92hm | Why do toilets(in america) use clean potable water? | Repost | explainlikeimfive | {
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"Our potable water supply is one thing I think we take for granted in North America. Using gray water would be waay better of course. You CAN get toilets that are specifically designed to use gray water, or some toilets that have the sink right _over_ the toilet for this purpose. Its just specialty bathroom ceramics (therefore $$$) and additional plumbing $$. If we were to have a separate supply system to take say industrial gray water (industrial outflow, water from laundromats, storm sewers etc.) - which would be ridiculously expensive to put in - then you have to worry about where the water came from. Last thing you want is hazardous chemicals dumped accidentally at the soap plant to vent fumes through every toilet in town. So now you're into water testing and quality analysis and maybe pre-treatment... hey, we already have a water plant that does that. Good idea in practice, essentially doubles your water supply infrastructure. No, the only way to do this on a practical home level would be for you to collect your rainwater in a cistern with solar pumps to move it to a tank in your attic. You'd still need to change the feed for your toilet and run new lines to each bathroom but its doable.",
"Water treatment is actually pretty cheap, whereas running another set of plumbing or having a built-in greywater system is more expensive. There are places where the true cost of clean water is not really factored into the price (e.g. the desert southwest) and in some such places people are beginning to install greywater systems so they can save water and be more environmentally friendly.",
"I used to work on a small island where fresh water was limited. There *had* been saltwater supplied directly to the toilets, but maintenance was a big issue.The site was built before plastic plumbing was available. So the toilets were connected to fresh water. Some years later, during a major rebuild, grey water flushing *was* considered, but was rejected due to complexity and maintenance issues. New low-flush toilets extended an improved fresh water supply.",
"Because then we would need another entire system to bring dirty water in for your toilet. As it is, a building only needs clean water in, dirty water out. This is easy to design. Otherwise, you'd need clean water in, dirty water in, dirty water out, and the dirty water in would need to be totally separate to avoid contamination. Also grey water can carry lots of diseases and animals drink out of the toilet all the time.",
"About 10 years ago, I used to work in Business Development and Engineering for a district steam company. We had 13 miles of supply piping, but the condensate was not returned back to the plant. Most customers just sent that water down the drain. However, I used to tell all of my customers that the water was clean and could be used for any non-potable use. The main thing preventing usage was the piping costs. However, in cases of new construction, I found that several clients took advantage of this \"free\" water. One client pumped it to a holding tank on the roof and that was the primary source for toilets. They had a valve on the domestic water line that would be engaged if the holding tank emptied out and for the summer when steam usage was generally non-existent. I also had a few clients that used the water for power washing plaza areas or for water fountain make-up water. There was some code requirement that did not allow usage for irrigation, but that would have also been a good use of the condensate. However, I was dealing with a built up downtown area, so irrigation needs were minimal even if allowed. On a related topic, a much higher percentage of clients used the condensate to pre-heat their domestic hot water since getting the energy out of the condensate can be easier than using the condensate water itself. Best of luck, Sol Rosenbaum, PE, CEM, CPMP I have written some articles on LinkedIn geared towards young engineers I think you might enjoy. I’d really appreciate it if you could have a look and give me some feedback on my articles. The link is URL_0",
"Two points: 1. Mine doubles as my dogs water bowl. 2. My bidet needs a clean cold water line. I don’t want grey water shooting up my butt.",
"The most efficient system I've been able to design takes waste water from showers & sinks condensates, washer etc and drains to a small settling tank, bout 500 gallons. The overflow goes to an ejection pump system that pumps to a tank at a high point to gravity feed all the toilets. That tank requires overflow switches to tell the ejection pump to stop pumping when it is full at Wich point a bypass valve opens to pump into the sewer system. This whole thing is easily 5-8k on top of 7k system. Not to mention all code violations required to accommodate this....aaaand you've stopped reading by now because this is boring as shit. At the end of the day all this extra juice and material negates any environmental benefit. Low flow toilets only use 1.2 gallons per flush. The sink in the tank is a good idea but it's illegal by universal plumbing code. Source: I own a plumbing company.",
"Because the water sits there, in the bowl, between uses, it has to be clean. Otherwise the toilet is just a cesspool (pun intended) for all manner of germs. The other major reason is that it is easiest to replenish the water after flushing from the tap, though chemicals like bleach are sometimes added in the tank to help the water stay \"clean\". However, when you do that, the water is most certainly not potable.",
"Because it is much much easier to just use fresh water than it is to drain everything into a gray water tank, separate major contaminates from that water, install pumps to bring that water to the toilet, and you would still need to hook up fresh water to it as a back up in case you run out of gray water. Water isn't so scarce that installing all that would be worth saving 3 gallons per day.",
"In addition, to other answers I'd like to point out, for most people in the country potable water is in near infinite supply. Almost the entire midwest have massive water tables underground, that on top of modern water reclamation facilities means generally speaking none of us have to worry about running out of drinking water. I'm sure a lot of us remember commercials telling us to turn off the faucet while brushing our teeth and so on. These ads were mostly for people in places with more limited water supplies like California or Arizon. (Mostly California as that's where the commercials were made) I personally have well water that is pumped out of a well that has been going strong since 1909, the water starts only about 8 feet below ground and goes on for at least 30 feet. It's connected to the same water table as pretty much every local municipality water supply, dam, and lake within 30 miles. If I want to leave every tap in the house on while I read War And Peace it doesn't matter. It's all going to go out into my septic tank, through the fingers and gets reabsorbed by the water table.",
"I had a grey water system for toilet for about 10 years. Not my house... This is only sink and shower water. The bowl was uncleanable. Nasty. We finally removed the system and replaced the toilets. It's ok for gardening if you watch what you run down the drain...",
"You'd have to build a separate plumbing system for toilets, incurring additional expense and complexity within the walls.",
"Grey water still stinks. You want your bathroom constantly smelling like sewage?",
"I once worked at a very environmentally conscious company. When we built a new office, we decided to use grey water for the toilets and for the lawn sprinklers. The \"grey water\" was basically rainwater that was collected and stored in a large underground cistern. The system was relatively simple to design and while it certainly cost more than a regular plumbing system, it was not outrageous. The real obstacle to our proposed system was the county permitting agencies. They were strongly against the use of grey water in any indoor plumbing use. We explained again and again that the grey water was only going to be used in toilets, so what's the big deal? Eventually, we won out with a small compromise. We could use grey water for the toilets, but we had to hang a sign prominently above each toilet that said \"Non potable water. Do not drink!\".",
"In order to use non-potable water in our toilets it would require plumbing our houses and cities with an entire separate set of pipes for the other water source and to ensure they can never mix by accident. This is a large cost when we could just clean some more water instead.",
"Avalon, on Catalina Island (off the coast of Los Angeles), uses briny water for its toilets. The city uses a desalination plant to create its fresh water. To reduce production costs, the whole city has 2 supply networks: one for fresh water, and one for a briny mix of fresh and salt water.",
"There is already some good answers but here is my take on it: Grey water need to come from somewhere. If it is from your own house then you still need some filter to remove some dirt and contaminant, plus kill the bacteria and virus that would grow in that water. Plus it would require a tank and a pump and extra space and extra piping. You could have a toilet-sink combo. I have seen them, but they are expensive and you would use more water than what is used by the sink, so would need to complement it with mostly clean water anyway... Then you could collect rain water, which still need to be filtered and all... Next is the city provided grey water. This would be great, except that you need to double the water infrastructure, double the maintenance, double everything including the leaks! The leaks can be a significant amount. Montreal for example lose I think about 30% of the water via the leaks. Double the infrastructure and you now leak 60% of the total water distributed! And why you need to treat the grey water? There is the odour of course, but as I said, bacteria and viruses. You take a dump, it splash back, and now you have some unknown bacteria and virus on you. You flush and there is always some water that splash, releasing some virus and bacteria in the air. You would need to kill all that, and remove it so the left over do not feed on the dead bacteria and the bacteria population come back as it was. You would still need to put lots of chemicals to keep it low, which is some extra cost... Finally, even in the best case, it would cost the same or more to provide the grey water. In reality it would just cost quite more money. Then we could go to the environemental side of this. With clean water only, the dirty water from the lake/river become almost pure, then used, then refiltered and released cleaner than what the grey water would be. If you have grey water, it would also have to be filtered that much, so it basically transfer the filtering at the sewer treatment plant instead of the drink water plant...",
"Plumber here, this would be a terrible idea. The idea of grey water being used as toilet water is simply unsanitary. It would be highly unsafe to have 1.6 gallons of bacteria filled water releasing germs and could spread disease. Most of the country has no problem in terms of fresh water shortage. Even California seems to be doing better in that regard. Try it yourself. Shit in your toilet and leave it there and you'll find your answer quickly.",
"We actually did this in Afghanistan. We what to recycle all of our water over there, so they would use whitewater for showers, sinks and laundry, then they used grey water for toilets, cleaning and spraying the roads to keep the dust from kicking up. Blackwater was recycled and made back into whitewater. I think. Drinking water was separate. It's a lot easier to implement when there's no physical infrastructure.",
"Where I live, we have plenty of water, so we don't need an entire second system of water supply and collection. My region extracts approximately 4/10 of one percent of the available groundwater. There literally isn't a need for it. Ever time I bring up the fact that I live in a place with a super abundance of constantly renewed ground water, and that there isn't a need for water saving where I live,I get down voted. I can't help That I live in an area with plenty of water. It is a fact.",
"Because then we would need another entire system to bring dirty water in for your toilet. As it is, a building only needs clean water in, dirty water out. This is easy to design. Otherwise, you'd need clean water in, dirty water in, dirty water out, and the dirty water in would need to be totally separate to avoid contamination. Also grey water can carry lots of diseases and animals drink out of the toilet all the time.",
"Because it would be extremely expensive to run a second set of pipes to every house and building to use for toilets. You would also have to have a second sewer system that only handled grey water instead of black water (sewage) that supplied the water for this new system.",
"Infrastructure and taking potable water for granted are the primary reasons, as everyone has already pointed out. Secondly, grey water does offer some degree of risk if not handled properly. There's a fair amount of material that you wash down the drain and might not want in a reservoir in your house. Think pathogens, parasites, fecal material, chemicals. No, you're not going to drink that toilet water, but having pool in your bathroom offers some risk (especially risky in hot climates/seasons and with infrequent use). Having a grey water system requires some serious behavioral changes to be done properly, and not wanting to change habits is a big deterrent.",
"I was just thinking about this the other day. I was a an event and had to used the restroom. When I went to use the urinal, there was a gigantic sign in front of it that read \"THIS STADIUM USES RECYCLED WATER. DO NOT DRINK FROM URINAL\". In all caps like that. So does this mean some stuff in america is allowed to use this type of system?",
"As a plumber, reading this OP and a lot of the replies was extremely stressful. That sink/toilet thing is stupid and impractical. Septic tanks dont send your poop into a leech field. The tank holds the solids and they need to be pumped out. Toilet bowls hold water to keep sewer gas from coming up through the toilet and stinking up your house. This is also why all sinks and floor drains have traps on them. I have been in thousands of houses and it is more of a surprise to see a clean toilet, rather than a dirty one. Bathrooms are disgusting as it is, so why add untreated, dirty sink water or whatever gray water could be, into that mess.",
"Many european countries do that, too. We do use clean 'drinkable' water for toilets in Germany",
"Because daddy is lazy and mommy thinks it's icky. (It's mechanically and financially more feasible for construction and maintenance, it is crystal clear and doesn't smell (aesthetics), and generally we've had plenty so we haven't been incentivized towards conservation)",
"My former condo in Victoria, BC had its own treatment plant, and the whole thing was purposely-built to high environmental standards. URL_0 Somewhat ironic since the City of Victoria has exactly zero sewage treatment, and it pumps millions of gallons of raw sewage into the Strait of Georgia every day.",
"I mean I would guess one of the reasons is so that our pets and children wouldn't get poisoned from drinking toilet water.",
"The whole theory behind \"grey water\" toilets seems silly to me. Once the water leaves the toilet and goes to a processing plant the water eventually gets treated and returned to the ecosystem. Once water goes down the drain it isnt simply gone forever.",
"Clean drinkable water isn't seen as a luxury in the US. We find it laughable that someone would put water in a bottle and charge $1 for it. We expect it to be free at restaurants and spend little time on conservation of it. It's considered a \"right\" rather than a resource, so we don't spend extra money or time trying to conserve it.",
"My grandmother's house used water collected from rainfall. The house was probably built in the 50's in rural Kansas. There was a holding tank dug into the ground near the house that all the gutters fed into. That water was pumped to the house for the toilets. Grandma was a young child during the depression. I never knew her to let anything go to waste. Not even the rainwater.",
"at least in the western US, the prior appropriation system makes it very hard to legally use grey water. \"return flow makes the river go\" CU Boulder had to fight for years to even use our grey water system half the time it was designed to run. Denver Water is giving everyone else the middle finger right now, and is using black and grey water in their new headquarters. Grey water is also an expensive retro fit. As a hydrologist, I hope to see more grey water use in the future. We spend a lot of money treating water",
"Some commercial buildings do this. It's probably not economical for most homes though, you'd have to catch the water used in the sink, hold it in a tank, then pump it back up to dedicated toilet only lines. It also really depends on where you live. If you live in the Great Lakes region, then there is basically no such thing as wasting water, since the water comes out of the lake, you use it, and it goes back in. The cost of treatment (monetary and environmental) isn't very high. On the other hand, if you were in say the outskirts of Pahrump or Amargosa NV, that might be a different story.",
"Because where do we get unclean, unpotable water in our plumbing system?",
"Tldr: it would cost too much money in a country with a relatively cheap and large supply of fresh water.",
"Because if its not, you would have infectious and dangerous pathogens sitting in a bowl of water in your house that actually aerosols outwards when flushed, spreading infectious mis and spray through the entire house. People would become very sick, and there are some places that use \"gray\" water but they tend to reek of high hell and have some infectious materials in them as well.",
"While a lot do, some buildings don't use them. In places like San Francisco, where water scarcity is becoming an imminent problem, building codes are requiring that grey water / process water be used in municipal buildings. San Francisco is even going so far such that buildings over a certain size (I think 250k square feet) must even (or soon will need to) recycle black water. That's sewage, folks, and they're pioneering solutions to reuse that water in a healthy way. We take it for granted; however, some areas are recognizing that we may not have clean water access in the future, especially after natural disasters, and they are preparing themselves.",
"At least in the Midwest, water is so cheap and accessible, that it doesn't really make sense to install a new system. Additionally, the water in the Midwest is pretty much a closed system in that much of the water never leaves the Great Lakes or the tributary rivers. What a lot of people forget is that the Midwest was once a giant swamp. It got drained a couple hundred years ago, but there are still massive ditches that run next to every road. When it rains even the slightest bit, those ditches (6-12ft deep) fill right up, and the ground oozes water because it is already soaked from the water table 1 foot below the surface.",
"tldr:because that would be stupid and pointless. ______________________ cause thats whats already piped into your house. clean in, dirty out. (besides, the whole \"wasted water\" thing is silly nonsense outside 3rd world or some smallish islands. water treatment is really cheap, running a whole second set of pipes through the house is not. and that clean water isn't going to be sent far away to places that need it anyway(far more cost effective to set up new treatment plants there than ship water out, nobody does that.)) also, grey water *isn't clean*. you don't want that stuff sitting around in your house. (unless you're real selective about the source standing grey water=smell/fumes in the air + corrosive chemicals and sentiment building up in the pipes. you'd almost want to build a whole new treatment plant to halfass purifying it) (edit- and the realistic environmental impact is negligible anyway too) ______________________________________ edit- change \"fist world countries\" to \"at the very least the entire continental united states and canada\" since allegedly some traditionally first world nations still have trouble with an maintaining adequate supply of clean water ;) (just messing with you australia) but op specified america anyway so the answer still works for the question asked.",
"Is this an American thing? I thought every first world country used potable water in toilets",
"Because greywater *stinks*, really bad, and you don't want a stench like that sitting in your toilet bowl.",
"Maybe the costs of using clean water are cheaper than the costs involved with having a second line to houses for \"Grey water\".",
"Honestly if the people who built/maintained my apartments tried to manage two separate *incoming* water systems, I would have died of dysentery already.",
"We have excess clean water in the us and using one water type(clean water) for all appliances means cheaper plumbing and less complications.",
"Just America? I've never seen a country where the water from the toilet was different from the one coming out of the faucet.... And I've traveled around the world...",
"The bigger question is why do American toliets have so much water in them? I always freak im goin to tea bag it and/or get splash back. Its just so excessively full compared to NZ",
"Basically because putting in all of the pipes to source water from somewhere besides the wastewater treatment plant or to use water that isn't as clean as the water from the wastewater treatment plant would be too expensive.",
"Using grey water to flush my toilet sounds primitive and nasty. Who wants nasty doo doo water splashing their ass cheeks every time they drop a deuce? Or when it pops back up and hits your cornhole. Why would i want to replace that experience with grey water? Wtf?",
"In the US clean water is cheaper than piping a second water supply or buying systems to reuse water. It's one of those things that might pay itself off over a life time for personal plumbing or several generations for city infrastructure, but people are not willing to take on the cost when they may never see the benefit.",
"The amount of water used in toilets is a drop in the bucket of our total water consumption. This, coupled with the fact that the water cycle in North America regenerates quickly means that it doesn't really matter. In the grand scheme of things, the water you use at home has no real effect. (except specific areas and/or drought)",
"Here in Australia new houses need to use tank water or other grey water for flushing the toilet and watering the garden. There is even a water recycling scheme in Western Sydney: URL_0 The main issue with using grey water to water the garden is that salt levels build up from the washing powder. Also tank water sucks for washing clothes. URL_1",
"When I was in the US Army in South VietNam, we used non-potable water for showering. I suppose we used it for flushing too, but I don't remember being told that. (We may not have even had flush toilets.) This wasn't my regular duty station, but where I was temporarily housed while I was being processed out to go to the big hospital in Japan.",
"I worked on an island where we had separate potable water and grey water (mostly captured rainwater) systems so I know it is feasible, but the answer is pretty simple. Throughout most the U.S. we already have a potable water infrastructure, and although fresh water is in short supply in some areas, it is still cheaper then installing an entire separate secondary system for grey water.",
"It would take Water companies billions of dollars to build an entire gray water system just for flushing your toilet. it would cost a lot of money for homeowners because they will need to adjust their already built pipings to the new system. It's not so bad. At least we're not draining our waste into rivers like they do in 3rd world countries. I've seen it first hand and it's sad.",
"Fresh water is cheap, and plentiful. Even here in the desert of Utah, residential use of water makes up only a small fraction of total water use, with the vast majority going to agriculture and another 5-10% or so going to water lawns. Every 5 gallons of fresh water costs me $0.01 on my water bill. My toilets are the low 1 gallon flushes. So I'll happily pay the $1 to $2 a month for toilet water opposed to the maintenance costs of running dirty water instead.",
"The simplest reason is cost, it is much much cheaper to just run one line to house and use the same water for drinking and cooking as you do for bathing and flushing, running a separate system just wouldn't be cost effective A better option would be to capture run off from baths and showers in the house into a holding tank then use this to flush but the work to install this kind of system yet again involves alot of upfront cost and takes years to recuperate, It is along the same reasons as why more people do not have solar panels, upfront cost is too high and savings take too long to pay back the outlay",
"It's because it's more economical to have only one line of water coming into a building. An entire network for grey water means additional complexities for not a whole lot of utility. See, in societies, we have this tendency to add complexity to deal with problems. Poop near your house a problem? Let's make a sewer. It's too far to walk to get some fresh water? Let's make a water system. Want to have electricity to provide all the utility that that brings? Let's add power network. But each of these systems has a build cost, and a maintenance cost. So now, we want to add a new water line, but this water is non-potable. So now we need identifiers for each line, that needs to very diligently documented (imagine the disaster if a plumber mistakenly hooks the grey line to your fridge water line, that will NEVER be purged, even if you don't drink any). Additionally, these people need new training, new manuals and new techniques need to be implemented (often just modifications of old procedures and techniques). You also need to have a pump system to push this grey water to your house, you need a source of grey water, which will mean have a multi-step purification system externally. (Think of the steps as: White Usage, First Treatment Step, Grey Usage, Second (Final) Treatment Step, Return to White, cycle) and this system would require ANOTHER sewer system to separate the grey waste to be turned white from the white waste to be turned grey. All this to poo in dirty water. Do you want to pay MORE for water? As much as pooping in dirty water makes *intrinsic sense*, it's really for the best that we use the fresh water. If you truly want to poo in dirty water, as /u/tezoatlipoca stated,you can simply get Sink-To-Toilet systems, but these are really expensive to buy and implement. Most standard bathrooms will have a hard time fitting these systems with the counters, showers, and toilets, without having a major rework of the bathroom."
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6s9at7 | Why is pleading 'not guilty' not considered lying to the court? | Repost | explainlikeimfive | {
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"Entering a plea is a procedural matter, not an evidentiary or substantial one. Pleading not guilty merely triggers the prosecution's obligation to make its case and prove all essential elements of the offence(s) beyond a reasonable doubt.",
"Logically it can't be considered perjury because the Fifth Amendment prevents the state from compelling you to incriminate yourself. For the legal system to function, they have to be able to compel you to enter a plea. Also, you aren't under oath when you plead. Theoretically you would be guilty of perjury if you took the stand and said \"I didn't do it\" (which happens less often than courtroom dramas would have you believe) but if you've already been found guilty the court has better things to do than try people who are already being punished.",
"Perjury only applies to testimony given under oath. Every person has the right not to incriminate themselves, and as such a court cannot order a defendant to answer such a question. When the court asks an accused to enter a plea, they are not ordering them to give testimony under oath. As such, when the court is asking to enter a plea, there is no perjury risk attached to the answer. In the American legal system, criminal defendants are presumed innocent until proven guilty beyond a reasonable doubt. The state has the burden to prove to a jury that the defendant is in fact guilty beyond a reasonable doubt. The defendant doesn't have to lift a finger in his or her own defense; unless the state presents sufficient evidence meeting that standard, the defendant must be acquitted. Therefore, when the defendant enters a plea of \"not guilty\", they are asserting their right to be presumed innocent unless and until the state can prove otherwise.",
"Perjury is lying while giving sworn testimony. Pleading Not Guilty is a demand for the Governmemt to prove what they accuse you of doing.",
"You are not pleading innocent. You are pleading not guilty. It's actually a very different thing. Also perjury is only a thing when you KNOWINGLY misrepresent to the court. So if you believe you have a defense, it's not perjury.",
"because, in america you are \"not guilty\" until proven beyond a reasonable doubt to be guilty, and they have to prove you are guilty before you are guilty. so its not lieing. you also have rights to not to incriminate yourself and the ability to face your accuser in court. there is a process, and step one of the process is to plea not guilty. thats why."
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6s9jya | What are sin, cos and tan? | Repost | explainlikeimfive | {
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"Draw a circle with a radius of one inch. If you draw a right triangle inside the circle at some angle, the Sine (sin) of that angle is the length of the vertical line, and the Cosine (cos) of that angle is the length of the horizontal line. The Tangent (tan) of that angle is just the Sine divided by the Cosine. URL_0"
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6sd2xd | Why does x^0 = 1? Similarly why does 0! (Zero factorial) = 1? | I know that they equal to 1, but why, what's the logic here? Something I've always wondered; that my teacher's never answered. | Repost | explainlikeimfive | {
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"When you multiply two numbers together with the same base, you add their exponents to find the answer. 2^3 times 2^2 equals 2^5 or 8 times 4 equals 32 e.g. x^0 * x^2 = x^(0+2) = x^2 = 1*x^2 so in the way that this was constructed, choosing x^0 = 1 makes the rule consistent when dealing with x^0 There is similar reasoning for the subtracting powers rule when dividing. n! can be used to compute how many permutations of n items there are. that is, how many lists of n items where order matters. e.g. you have an orange and an apple. You can arrange it to be {orange, apple} or {apple, orange} 2! = 2*1 = 2 If you only no items, there's only one way to order it. The empty set { } so from the viewpoint of using factorial to compute permutations 0! = 1 is a good choice. There's probably other uses of factorial that I'm not aware of where 0! might be chosen to be something else so that it is consistent with that usage",
"Yer not alone in askin', and kind strangers have explained: 1. [ELI5: how do we know x^0 is 1? How did we figure this out? ]( URL_1 ) 1. [ELI5: Why does 0! (zero factorial) equal 1? ]( URL_0 ) 1. [ELI5: Why is 0! 1 and not 0? ]( URL_3 ) 1. [ELI5: Why is \"x^0= 1\"? ]( URL_5 ) 1. [ELI5: Why x to the power of 0 = 1? ]( URL_2 ) 1. [ELI5: Why is x^0=1 ? ]( URL_4 )",
"If you understand that: x^1 = x and x^(-1) = 1/x (as long as x is not zero) then you should understand that x^(1)\\*x^(-1) = x\\*1/x but x^(1)\\*x^(-1) = x^0 and x\\*1/x = 1",
"Answer to your first question is simple: I think you'll understand this: x/x = 1 now, if you say: x^2 / x ^2 This can be re-written to xx/xx or you go this way: x^2–2 which then ends up being x^0 0! = 1 is just defined this way, since it is the only value that makes sense.",
"The same reasoning holds for both of these, and it's the same sort of reasoning that leads to x\\*0 = 0. One of the nice properties about addition (and multiplication) is that the order you add things up in doesn't matter. If you want to find the sum of the list [1, 5, 3, 2, 7], you could add up the first three elements (1+5+3=9) and then add the last two (2+7 = 9) and then add those results together (9+9=18), or you could add up the first two elements (1+5=6) and the last three elements (3+2+7=12) before adding *those* together (6+12=18) and you'll get the same result. We'd like this property to hold for *any* way of splitting [1, 5, 3, 2, 7] into smaller lists. For example, we'd like to be able to say that the sum over [1] plus the sum over [5, 3, 2, 7] is also 18, and since we know the sum over [5, 3, 2, 7] is 5+3+2+7 = 17, it must be the case that the sum over the single element [1] is just 1, as we might expect. But what if we split it up in an even more extreme way? What if we put *zero* elements in the first part of the sum and all five in the second? Then we'd have \"the sum over [] plus the sum over [1, 5, 3, 2, 7] is 18\". But we already know the sum over [1, 5, 3, 2, 7] is 18, so the \"empty sum\" of zero objects must be 0. And it doesn't matter what the other elements in the list are - the empty sum will always end up being 0 through the same logic. If we define multiplication as repeated addition, we have x\\*2 representing the sum over [x, x], x\\*3 representing the sum over [x, x, x], and so on. In particular, x\\*0 is the sum over [] and is therefore 0. So x\\*0 \"should be\" zero, if we want our definition of multiplication to be natural. The exact same reasoning works with products, but with 1 as the value of the empty product. If the product over [2, 4, 3, 2] is 2\\*4\\*3\\*2 = 48, then we not only want the product over [2,4] times the product over [3,2] to equal 48 (which it does, since 8\\*6 = 48), but also the product over [] times the product over [2, 4, 3, 2] to equal 48, which implies the product over [] is 1. Then x^n is the product over [x, x, ..., x] with n copies of x, so that x^0 is the \"empty product\" and therefore 1. Similarly, n! is equal to the product over [n, n-1, ..., 2, 1], which is the empty product when n is 0.",
"In regards to your second question, it's mainly for the sake of continuing the sequence. 4! = 1 x 2 x 3 x 4 = 24 We can then divide that by the greatest number to get 3!, And so on and so forth. 4!/4 = 3!, 3!/3 = 2!, 2!/2 = 1! Since 1! is just 1, dividing it by the greatest/only number still leaves you with 1 Does that make sense?",
"The answer is that we want x^0 and 0! to conform to certain generalizations that work for numbers other than 0. For x^0, we want the equation x^a /x^b =x^(a-b) to work when a=b just as well as it does when they are not equal. Obviously x^a /x^a =1, so x^(a-a)=x^0 must also be equal to 1. In the case of factorials, it's to make combinatorial formulas work better. For instance, there are n!/b!(n-b)! ways to choose b objects from n objects if b < n and b > 0. If we define 0!=1, the expression also works for b=n and b=0.",
"X^a divided by x^b always equals x^a-b. Also, X^a / X^a always equals one (any number divided by itself is one). If X^a /x^a =1, then X^a-a must be equal to one. X^a-a is X^0 , so X^0 =1. For 0!, I always thought of it as an artifact of n!/(n-1)! =n. This makes sense- 5!/4! = (5x4x3x2x1)/(4x3x2x1), which clearly is just 5. Therefore, 1!/0! Must be equal to one, and if 1! Is also equal to one, in order for 1/0! =1 to be true, 0! =1"
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6sd79t | Why is South Korea so dominant in eSports? | Repost | explainlikeimfive | {
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"When i first started playing League of Legends, I got interested in the competitive scene. Don't play as much anymore but still follow the scene. Koreans dominate in LoL simply because they take their practice more seriously. They individually play the game for longer hours than the players from teams of other countries they face. The teams are run more efficiently with coaches, psychologists, etc. and team practice and the formation of chemistry is more focused on. Eventually it becomes a cycle where the best competition is in Korea and so if you aren't playing in Korea, you aren't facing top tier competition so you won't improve as much as people playing in Korea. Sort of like if you want to be the best football player ever, if you aren't playing in Europe, you don't have a chance. Teams from other countries try to imitate, but they are lagging behind in infrastructure and overall attitude of practising and \"tryharding\" to improve.",
"South korea has a culture around eSports like America and football, or most of the world and soccer. Matches are held in arenas with large audiences just like physical sports here. There are college courses dedicated to eSports, and it is treated as a profession. Competitors will spend more time practicing their game of choice than westerners spend at work, upwards of 12 hours per day."
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6se6x9 | How does a conductor conduct music by waving a stick around? | Repost | explainlikeimfive | {
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"The basic gist of it is that the conductor keeps time. The conductor moves their baton in such a way that it comes in contact with an imaginary surface (the ictus) on each beat. The movements are repeating over the course of a measure, so for 4/4 time the conductor will repeat a motion of 4 beats. The conductor further adds in their own emphasis to be interpreted by the musicians in the orchestra. Such as large intense movements to emphasize that a certain part of the piece will be very loud and thundering, or gesturing towards certain instrument sections. This is all within the context of the piece being played, which most orchestras will have practiced together multiple times. The conductor isn't communicating WHAT to play, but instead ensuring that the entire orchestra is in sync."
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6sfgu4 | how does the fourth dimension work? And what does it mean? | Repost | explainlikeimfive | {
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"Mostly, people refer to time as being the fourth dimension. It's a different concept than the other three, but the basic idea is the same: how much information do you need in order to uniquely identify an event? You can specify any location with three dimensions: say, latitude, longitude, and altitude. But if we're meeting for dinner, that won't be enough. You'll need a time to actually get there.",
"You live in a 4 dimensional universe. Three dimensions are distance (spacial) and one is time (temporal). The speed of light (C) is the ratio of the distance in the temporal one, the one we call time, to the distance in the spacial ones, which we call distance. Every object exists as a unit velocity segment in this 4-space. Since a 4-space is hard to think about, let's simplify (ELI5!) by considering the spacial dimensions in terms of our motion. Now we only have one spacial dimension, the direction we are moving. Turning (for the time being) doesn't count. Next we graph our 2-space universe, with time on the vertical and distance on the horizontal. Every object is one unit from the origin on this graph, a quarter-circle. If a segment is aligned with the time direction (it's vertical), the object's spacial dimensions must be 0, this gives 0 speed in space and 1 second per second in time. If the velocity segment is oriented along the spacial dimension (horizontal) the object is moving at C, and since all segments are one unit long, it must be 0 in the temporal dimension. Thus photons move at the speed of light but do not experience changes in time. Gravity and other forces use energy to change the orientation of an object's velocity segment, accelerating it in space and shortening the time element or decelerating it in space and lengthening the time segment.",
"URL_0 Here's a video of Carl Sagan explaining it. He does a great job of dumbing it down and showing clear visuals. Hope it answers your question"
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6sfjg0 | Why do some words feel like they aren't words anymore when you say/write them a lot? | Repost | explainlikeimfive | {
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"It's called semantic satiation. Basically when you repeat a word enough your brain will just interpret it as white noise URL_0"
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6sfjym | Why is mint the go to flavor for toothpaste, mouthwash, etc? | Repost | explainlikeimfive | {
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"When toothpaste was first introduced most people didn't use it regularly like we do today because they either forgot about it or didn't notice if they missed a brushing here or there. When companies started making mint toothpaste, people started to notice if they didn't brush their teeth because the tingly feeling after brushing was associated with a clean mouth. The habit that developed made mint toothpaste the best selling kind by far, and it continues to this day.",
"Japanese toothpaste and medicine sometimes tastes like root beer and they generally don't like to drink root beer because it reminds them of it.",
"Because mint is very good at masking the smell of bad breath.",
"Sorry that i can't answer or ELI5, hope this post is still allowed. But if you go to the pet store you can get toothpaste in peanut butter, banana, beef, bacon, and a few other flavors.",
"My kids (ages 1.5 and 3.5) toothpaste is different flavors like orange, bubblegum, etc...and I think they taste awful. Not sure when mint comes into the equation, when they get a bit older I'd imagine. Perhaps the flavor is too strong for many young palettes? Idk. Interesting question though...sometimes standards maintain for CPG, other times they evolve from marketing campaigns to capture the desired demographic.",
"The aroma of the herb activates the salivary glands in our mouth Improving the health of a person’s mouth is a well-known benefit of mint. Since it has germicidal qualities and quickly freshens breath, it adds to oral health by inhibiting harmful bacterial growth inside the mouth and by cleaning the tongue and teeth. This is why, mint used to be rubbed directly on the teeth and gums to refresh the mouth and eliminate dangerous forms of growth. In modern times, for the same reason, mint is one of the most common elements in toothpaste, mouthwashes, and other dental hygiene products. Of course, the easiest way to get these results is to simply chew on the leaves. URL_0"
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6sfoq3 | Why did we decide that certain words were "bad" and shouldn't be used in social settings? | Repost | explainlikeimfive | {
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"There is an excellent podcast by Stuff You Should Know that is entirely about swear/curse words. They explain the history, psychology and science of curse and swear words, which are actually two different things."
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6sj97d | How does a record work? | Repost | explainlikeimfive | {
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"Sounds are waves. A guitar string produces waves by vibrating the air. Changes in sound occurs when these waves differ in frequency. Vinyl records work by creating sound waves with small scratches on its surface. When the surface is \"scanned\", a small reader moves along the contours of the scratches that exist in the disc. This creates vibrations in the point, which is transfered into an amplifier that produces sounds. The vibrations vary as the point reads a different scratch mark, which creates the different sound wave."
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6sjqom | why are USA using imperial system rather than the international system? | Repost | explainlikeimfive | {
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"We were established as a country before Metric was invented, we spent most of our history being highly self reliant, and until WWII we were fairly Isolationist. After WWII we spent several decades as the industrial power of the world providing the materials Europe and others needed to rebuild. It only became reasonable for us to switch in the last few decades, and by this point in time so much of our infrastructure would have to be changed that it is not feasible. And as you point out we are very independent and so any foreign entity that pressures the US to change something will be met with extreme resistance by the populace."
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6sk3q8 | How come some words lose their meaning when repeatedly saying them out loud or reading them? | Repost | explainlikeimfive | {
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"[Semantic Satiation]( URL_0 ) > The explanation for the phenomenon is that, in the cortex, verbal repetition repeatedly arouses a specific neural pattern that corresponds to the meaning of the word. Rapid repetition makes both the peripheral sensorimotor activity and central neural activation fire repeatedly. This is known to cause reactive inhibition, hence a reduction in the intensity of the activity with each repetition. Jakobovits James (1962) calls this conclusion the beginning of \"experimental neurosemantics\". Stolen from Wiki...and probably using words bigger than suitable for a five year old (sorry)."
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6sk9ue | Why do we not like listening to our own voices in a recording or video but are perfectly fine listening to them as we talk? | Repost | explainlikeimfive | {
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"You're used to the sound you usually hear when you talk. However, this is not how you actually sound. Your actual voice is higher than what you hear due to the sound passing through your head. Since you rarely ever hear yourself recorded, you naturally have an aversion to it. If you got used to hearing your recorded voice, you wouldn't hate it as much."
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6skgg1 | How headphones can create auditory illusion of hearing from behind despite the fact that the sound only comes from left and right ? | Repost | explainlikeimfive | {
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"The same way you do with only two ears. Time lag, wave length and tone - all these factors play important parts for the brain when determining the direction of sound. In the following description, they are treated under separate headings, but when a person registers a sound, all three factors interact, helping to determine the direction from which the sound originates."
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6skosl | Outside of academia, who employs modern philosophers and what is their role in modern society? | Repost | explainlikeimfive | {
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"I'm sure some more will come to mind soon, but the first one I thought of: Ethicists. When a company or corporation needs to go through an ethics committee, those people are philosophers. Similarly, before doing any experiments (e.g. in science) you also need to get ethics clearance. Ethics is a big domain of philosophy. Edited to add: Also, I know this is kinda covered by \"academia\", but the main thing that philosophers do is write papers for publication. Whether it's in ethics, metaphysics, aesthetics, philosophy of science, stuff about personal identity or time travel or whatever. Philosophers are the ones researching and writing about it! (Source: am married to a philosopher).",
"**Copy-pasting my response to this question from a previous [ELI5] ( URL_0 )** > Let me start with this: my undergrad is Philosophy. > Today: Lets make a distinction between Philosophers - people who DO philosophy for a living - and philosophy students - people who use the general tenets gained by in-depth study of philosophy in their day-to-day jobs. Philosophers, those who do, tend to be employed in very limited fields, traditionally academia. These are university professors and authors. They make their money by teaching others philosophy in classes and through media (books, videos, whatever). I fall into the latter category. I use my background in philosophy in the workplace. This is what typically happens if someone does their undergrad in philosophy and gets a decent job. I \"sell\" skills like inductive and deductive reasoning, rational inquiry, the interpretation of complex material into simple terms, and excellent oral and written communication into a position I am interested in (I work in organizational development). Because I sell these things, plus experience, I can get a job that provides. That is how I, and many others, make money from philosophy. By no stretch of the imagination are we Philosophers (other than the shade-tree sort). But, if you are interested in pursuing the degree, know that it is possible to live (in the US, pretty well) if you market it well. Many use philosophy to pursue advanced degrees or positions in Law (my friend Joy), Economics ( my friend Sara), Business (my buddy Nate), or Industrial and Organizational Psychology (me and two others from my grad school cohort). > I will always remember the opening words in my freshmen \"Intro to Philosophy\" text: Philosophia non panem torrit. Philosophy bakes no bread. Philosophers, today and throughout history make very little from doing actual philosophy and very much from applying to something whether it be teaching others, solving complex problems, or maintaining an organization.",
"Two that haven't been mentioned: Computer science - Computers are, at the basic level, logic machines. Logic is one of the four original branches of philosophy. The best computer programmers use careful logical reasoning to solve problems in the most efficient way possible, then convert that reasoning into logic-based coding. Aristotle would've been proud. Judge/lawyer - Law and philosophy have a close relationship, and philosophy is one of the most common pre-law school majors. In many ways law is basically applied ethics and political/social philosphy.",
"Like a lot of social sciences, Philosophers are surprisingly flexible in terms of employability. Stuff like HR departments or PR employ all kinds of professionals, lecturer at a publisher, editors of newspapers, journalists all can and will occasionally employ Philosophers (or people with a degree in philosophy to be precise) If you have a degree in philosophy you are well trained in logic, ethics and in the work with text based sources of any kind. You could even work in a SIGNIT department of a intelligence service.",
"I'd say lots of them write books and/or articles and essays which they sell to magazines or even get invited to tv talk shows to discuss things. A philosopher or public intellectual can also rely on making a show of his/her own on youtube and monetize on that. But I think books and generally written stuff is the main source of income. Which ones do you have in mind?"
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6slgp2 | Why does the United States have so many military facilities on foreign soil, while other 'superpowers' do not? | Repost | explainlikeimfive | {
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"What other superpowers? It's those very bases you speak of that makes the US a superpower in the first place. Most militaries are structured defensively. They primarily exist to protect a country's borders. That's necessary when you exist along side many other countries. What good does a base on the other side of the world do when all you are charged with is protecting your own border? The US has no such borders to worry about. They won't be invaded by Mexico or Canada any time soon I promise. A large number of troops stationed in the States would be a total waste. Unlike almost all other militaries, the US is an OFFENSIVE military. They are charged with bringing power to wherever the party is. You can't do that without bases. Currently the US (and UK) has one of only 2 Blue-water navies on the planet. The reality of it is, for better or for worse depending on where you stand, the US is the world police and (if you are a NATO member) the \"world\" protector. In order to be the world police, you gotta have bases everywhere.",
"Late to this party. As others have mentioned it, there are no other superpowers in the world currently. Having the ability to project power overseas is a big part of why the US is a superpower, and others are merely major powers or regional powers. Also, the policy of the US having facilities on foreign soil comes out of WW2. In fact, in General Marshall's [*Biennial Reports of the Chief of Staff of the United States Army to the Secretary of War: 1 July 1939 - 30 June 1945*]( URL_2 ) (official URL_7 link), Marshall writes on 1 September 1945, the topic of future defense/security policy: > The German armies swept over Europe at the very moment we sought to avoid war by assuring ourselves that there could be no war. The security of the United States of America was saved by sea distances, by Allies, and by the errors of a prepared enemy. For probably the last time in the history of warfare those ocean distances were a vital factor in our defense. We may elect again to depend on others and thee whim and error of potential enemies, but if we do we will be carrying the treasure and freedom of this great Nation in a paper bag. He then writes: > Even as late as 1940 I was asked very much the same question before a committee of Congress. Not even then could I say definitely exactly where we might have to fight, but I did recall that in past wars the United States forces had fought in Latin America, in France, in Belgium, in Germany, in Russia, in Siberia, in Africa, in the Philippines, and in China, but I did not anticipate that in the near future American soldiers would fight in the heat of Burma and in the islands of the vast Pacific, and would be garrisoning areas across the entire land and water masses of the earth. From this lesson there is no alternative but that this Nation must be prepared to defend its interest against any nation or combination of nations which might sometime feel powerful enough to attempt the settlement of political arguments or gain resources or territory by force of arms. And then: > At the close of the German war in Europe they were just on the outer fringes of the range of fire from an enemy in Europe. Goering stated after his capture that it was a certainty the eastern American cities would have been under rocket bombardment had Germany remained undefeated for two more years. The first attacks would have started much sooner. The technique of war has brought the United States, its homes and factories into the front line of world conflict. They escaped destructive bombardment in the second World War. They would not in a third. > **It no longer appears practical to continue what we once conceived as hemispheric defense as a satisfactory basis for our security. We are now concerned with the peace of the entire world. And the peace can only be maintained by the strong.** Emphasis mine. This is taken from page 209-211 in the section *For The Common Defense*. As you can see, military thinkers - before Japan even signed the Instrument of Surrender - were already thinking about a new world after WW2 and the necessity for the US to go beyond its isolationist roots and think about defending its interests overseas, far from its shores across the oceans, which were soon to be no longer a viable defense. One poignant part that Marshall brings up too is that the captured German leadership pointed out that by late 1946 or 1947, the East Coast of the US would be in range of future German rockets and bombers. Thus, using the oceans to defend one's own self is no longer viable. I also feel it is important to point out that the bulk of US troops overseas actually are rooted in history as well: [the list of US troops stationed overseas, as illustrated in this graphic by Time]( URL_14 ) shows that for individual nations: * Japan - 48,828 * Germany - 37,704 * South Korea - 27,558 * Italy - 11,697 * Afghanistan - 9,800 Now, Afghanistan is obviously a war zone. But then you see that 3 of the top 4 are the vanquished Axis foes of WW2, all of whom were occupied after the war (and some, like Germany, didn't have their full sovereignty restored until [the end of the Cold War]( URL_8 )). The other one is South Korea, where US troops have been present since the end of WW2, first to occupy south of the 38th Parallel (with the Soviet Union occupying north) after Japan's defeat, and then as part of the US forces of the UN Command to defend South Korea in the Korean War, and then as [part of the Mutual Defense Treaty Between the United States and Republic of Korea]( URL_0 ) signed October 1, 1953. Finally, I want to point out that while no other countries have military bases in the US - there is a considerable presence of foreign troops in the US that most do not realize. For instance, here is the US State Department's Foreign Military Training Joint Report to Congress for 2015-2016: URL_3 This is an annual report with all unclassified data published online for public use. This file lists each of the 80+ nations that the US had training operations conducted with, including a breakdown by location in the US where it was conducted. This list excludes NATO nations, Japan, Australia, and South Korea. In addition, the US has had long term foreign troops stationed in the US. The German Air Force [has been in Holloman Air Force Base, New Mexico]( URL_1 ) (official URL_10 link) since 1992. The German Air Force has been in the US since 1958. The US Air Force also has the Euro-NATO Joint Jet Pilot Training (ENJJPT) program at Sheppard AFB which has been producing jet pilots for the US and 13 other partner nations [since 1981](http://www.sheppard. URL_10 /Library/Fact-Sheets/Display/Article/367537/euro-nato-joint-jet-pilot-training-program-enjjpt/). The Italian Navy sends all of its pilots to the US for training by the US Navy and US Marine Corps. [Embassy link here]( URL_11 ). I would know too - I trained with quite a few of them. How little do people even realize these foreign troops in the US? The US Air Force's 428th Fighter Squadron is in fact a Republic of Singapore Air Force unit [which has been in the US since 2009](http://www.mountainhome. URL_10 /News/Article-Display/Article/665884/peace-carvin-v-singapore-celebrates-5th-anniversary-with-us-air-force/). That unit flies the F-15SG. Yes, tiny Singapore has an Air Force squadron in the US. Correction, it has more than one: the 425th Fighter Squadron is also a Singapore Air Force squadron [which has been at Luke AFB, AZ since 1993]( URL_6 ). They fly the Singaporean version of the F-16. So while these units are renting spaces in existing US bases that still have US commanders, this is quite akin to the arrangement the US has with may other countries like Soto Cano Air Base, which is a *Honduran* air base where the US has a detachment - [Joint Task Force Bravo]( URL_13 ) located. And lastly - other nations DO have military facilities on foreign soil. I'm not entirely sure where people get this idea that other nations don't have troops overseas. China just built its [first overseas base in Djibouti, Africa]( URL_4 ) The UK in November just opened a new base [in Bahrain, called HMS Jufair]( URL_9 ) [France has bases]( URL_5 ) in Djibouti, Senegal, Ivory Coast, Gabon, and the UAE And so on",
"There are no other superpowers, first of all. To answer your question: America is isolated from the Europe-Asia-Africa landmass by two large oceans. Over 80% of the world's population lives in Europe, Africa, and Asia, meaning that that's where most geopolitical problems are going to occur. It is difficult to support a military operation from so far away, so America has built bases close to where the action is to solve that problem.",
"Well there isn't any other superpowers currently. Other large countries do have military facilities on foreign soil, but not as much as the US. France and the UK have a good amount of military base on foreign soil, mostly in their ex colonies. Russia also have several of them, but those are mostly in ex-soviet country. China have a naval base in Djibouti and since China is on the path to becoming a superpower, it will probably have more and more of those base in the future.",
"America has mutual-defense treaty obligations with a number of allied countries. Due to the distant locations of some of those countries, it would be logistically impossible to fulfill those obligations without having the personnel and materiel resources readily available on their soil. Additionally, having those resources in place also serves as a deterrent to any who might threaten that ally.",
"There are no other superpowers. There are world powers, but that is a lesser category of influence than a superpower. When the USSR was a superpower they had bases among their allies like the US does currently, but that ended when the USSR fell. Russia in its lower power position still has some, but not nearly as many."
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6srgtt | Triboluminescence? | After watching a video regarding a Prince Rupert's Drop, the term "triboluminescence" was coined as to why there was light created from a bullet striking it. When this term was first discovered in the 1600s, it was referred to with hard candy, and striking it creating sparks. Where do the sparks come from? | Repost | explainlikeimfive | {
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"It seems to be not completely understood, but the fracturing of the glass produces a charge separation - there are fewer electrons on one side of the fracture than the other. There's then a sharp electric current (flow of electrons) through the gap to equalize the charges, which ionizes the air in between as in a lightning strike, producing the light."
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6srs3p | Why do prefixes Sept-, Oct-, Nov-, and Dec- mean 7, 8, 9, and 10, but they refer to the 9th, 10th, 11th and 12th months? | Repost | explainlikeimfive | {
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"Because there used to be only 10 months, not 12 - January and February were added later. Prior to that, the ~60 days between December and March were just 60 days of winter that didn't belong to any month. The year also began in March, not January. And before anyone says it: no, it wasn't July and August that were added. Those were renamed from Quintilis and Sextilis (which follow the same naming scheme as the last 4 months), long after January and February were added."
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6ssd0o | Why after you chop some onions the smell in your hand lingers for a century while perfumes fade away? | Repost | explainlikeimfive | {
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"IIRC, most perfumes are alcohol based. Alcohol is very volatile, and the majority of it evaporates quickly after leaving the bottle. That's why if you ever talk to someone selling perfume (sometimes you can't help it), they tell you to let the scent mellow for a little bit before you really know what it will smell like. The compound that gives things like onions and garlic their potency is released when you cut into them, and is intended as an irritant. This was to ward off things that would otherwise eat the onion in the original habitats. Side note, these compounds have the ability to destroy the cells of dogs and cats, so should never be fed to them in any form. The compounds released by cutting onions convert their amino acid sulfoxides to sulfenic acid. This what makes you cry, but also what sticks to your hands, and is very difficult to remove with normal washing. Most guides say stainless steel will help to remove the odor, and I've found it usually works for me.",
"Because it soaks into your body. Yer not alone in askin', and kind strangers have explained: 1. [ELI5: why do smells like onions and vinegar linger on your fingers no matter how many times you wash your hands? ]( URL_0 ) 1. [ELI5: Why do flavors like garlic and onion stick around in the taste buds so much longer than others? ]( URL_1 ) 1. [ELI5: Why does the smell of onions stay on my hands for a such a long time? ]( URL_2 )",
"Not an explanation but advice that might be useful if you are on this thread: You can get rid of most of the smell of onion and garlic from your hands if you wash your hands without rubbing them, just let the water run on your hands for a few seconds. Is doesn't get 100% of the smell but it's better than the usual method."
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6stpbq | Why is liquid water so hard to compress | Repost | explainlikeimfive | {
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"Primarily because it is already really dense. The polar nature of water brings the molecules of water really close together naturally under normal pressure and at that point it is really difficult to get them closer together.",
"The molecules are too close together. If you compress water the forces between the molecules stop them getting much closer, so you can't really change the density"
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6stput | Why do people's stomach look bloated when they're malnourished? | Repost | explainlikeimfive | {
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"It's called kwashiorkor, and it's a sign of serious protein deficiency. The stomach gets bloated because of fluid retention and because the liver expands with fat deposits. Interestingly enough, kwashiorkor gets its name from what an African tribe called it. Translated, it means \"disease of the deposed child\". What would happen is that when a 2nd child was born, the first child would be abruptly cut off breast milk and put onto a more adult diet high in carbs and low in protein. This resulted in protein deficiency.",
"Hey, just wanted to clarify some things. Severe malnourishment has several sequelae (outcomes) depending on what exactly is lacking in the person's diet. The two that most people are familiar with are (1) Kwashiorkor - the kind with the really big belly and (2) Marasmus - The kind where the people look like walking skeletons. In marasmus, there is generalized severe malnourishment. These people are sick because they are lacking sufficient calories, thus they become incredibly skinny - they are literally wasting (actual medical term) away. In Kwasiorkor, there is sufficient/close to sufficient caloric intake, BUT there is INsufficient PROTEIN intake. This means that the diet is mostly rice, corn, etc. Your body needs proteins for countless things such as building muscle etc. It also needs proteins to transport fats (not soluble in blood/water) throughout your blood stream. These 'transport' protein are called lipoproteins and are made in the liver. Without these proteins, the fats consumed by the body get trapped in the liver, leading to fatty livers (contributing to the big bellies). Also, proteins are needed to maintain the proper fluid volumes in your body (I won't get into this now) and without it, you retain water, contributing to fluid retention (medically called edema), and thus also making the bellies bigger. I hope this helped :) (Source: 3rd year US Medical Student - Thanks for letting me review this concept!) EDIT: XD This is the first time i get gold! Thank you guys!!! (I guess med school paid off after all haha)",
"That's called *kwashiorkor*, and it happens when there's not enough protein in a person's diet. Protein in the blood keeps water bound in blood, and if there's not enough protein then the water leaks out into the tissues, mostly in the stomach and abdominal area.",
"A lot of people are saying its protein deficiency, but if so I'm curious why people in developed countries, for example anorexics, don't typically get bloated stomachs from malnutrition. If it was just protein deficiency wouldn't they get that too?",
"Now question to anybody who knows: is having this issue a binary thing? Like you have it or you don't? Or can you have a mild/gradual case of it? I've had friends before who I thought were borderline malnourished and looked incredibly skinny fat or had developing, weird looking stomachs...",
"When you're so malnourished your liver can't make a protein called albumin, which is required to keep fluid in your blood vessels. This causes fluid to leave the vessels and enter a cavity like your abdomen. It's the same reason why people with liver cirrhosis get abdominal distension.",
"Protein deficiency. Protein in the blood, primarily albumin, is largely responsible for the osmotic force that keeps water in the pressurized vasculature from leaking out. ELI5 version: if you don't eat enough protein, your body can't put the proteins into the blood that keep water in there. The water leaks out into the abdominal cavity, among other places.",
"There is also such this as protein sickness, where you have too much of it and not enough other things. This why killing a deer is enough meat to feed you through a winter in the wilderness, but you'll get sick if you do not find other sources of nutrients.",
"I was always told that parasites and tapeworms caused this. Glad to finally know the true reason.",
"As people have said, protein deficency; leaky blood. Also, parasites in contaminated food or water sources.",
"As many had say is because of low protein intake, which leads to low albumin, which leads to a drop in oncotic pressure, which leads to loss of plasma to the tissues (edema), when we talk about the peritoneal cavity is called ascites, thats why people look bloated, they have peritoneal fluid in there, you can document this by doing the fluid wave test or an ultrasound.",
"A lot of people already answered regarding lack of protein. This is one of the reasons we send Plumpy Nut to famine hit areas. URL_0"
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6suct4 | Why do some objects fade their own color under sun? | Repost | explainlikeimfive | {
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"The UV rays can break down the chemical pigments that produce color. This results in color fading over time. The reflectivity if the object will impact the absorption of UV light and therefore impact the rate and degree of fading."
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6svgru | How encryption isn't easy to decrypt | Repost | explainlikeimfive | {
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"You are right that there are flaws in some encryption systems that store the key in the same place as the encrypted data. This is like hiding the key to your house under your door mat. This is why most systems will ask you for a password to unlock your encrypted data. The password itself is the encryption key. There is also a problem that if you have access to the encrypted data the key have to be located in RAM. So if some attacker is able to access your RAM he may be able to get the key from there. This was the big issue with the heartbleed bug that allowed a remote attacker to read a random section of the RAM which may contain secret encryption keys. One possible solution to this is to use a Trusted Platform Module which is a separate hardware chip that is able to hold a key but will not hand it out. All encryption and decryption will happen inside the device. Cell phones have had such devices for a long time as the SIM card works like that. Although it is not available for any application."
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6svvot | If the U.S is in so much debt, how is the American dollar still worth so much ? | Repost | explainlikeimfive | {
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"The value of a countries currency has very little to do with it's debt obligations. There are nations with no debt that have currency that is considered worthless to the rest of the world.",
"Think about a bank. Technically, every account a bank has is considered a debt. Now ask, why are banks not poor.",
"Because there is a lot of American productivity, demand for American goods and services, and the U.S. can easily handle its debts. No different than somebody with a mortgage and car payments totaling 4x their income still having an 800+ credit score."
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6sxkxv | Why do cans with compressed gases in them feel cold after you spray their contents? | Repost | explainlikeimfive | {
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"because it's not simply compressed gases. it's a chemical that's in liquid form when under high pressure. when it's in low pressure, it turns from liquid to gas and extracts heat from its environment. this type of chemical is commonly used for refrigerant."
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6sxoe9 | do bugs and insects feel pain ? | Repost | explainlikeimfive | {
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"do they squirm when you squeeze them? if so yes.",
"Yes. Bug's and insects have a state of consciousness, with nerves, brain, blood, etc. Just like humans and other animals All of these things contribute to feeling pain."
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6sy7am | How does an automatic transmission work? | Repost | explainlikeimfive | {
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"Oh man, I dont think I can actually ELI5 it, but ill try. Ok, first things first, the whole point of gears in a car is to convert the very fast but not very \"strong\" rotation of the engines crankshaft, to slower but \"stronger\" rotation of the wheels (basically you need to convert torque). In a manual gear box, you do that by pressing the clutch to disengage engine from wheels, and change gear ratios, literally you move around cogs with different diameters by hand. There are three kinds of auto transmission: 1) double clutch and robotic manuals these essentially use computers to do what you would do by hand by predicting via sensors engine RPM, wheel rotation, driving style etc. 2) CVT (continuously variable transmission) You have to conic shaped gears that are connected via a belt or chain, you slide the chain on the cone diameters to vary gear ratio. 3) Fluid torque converters, you have a casing that contains a viscous fluid and three bladed fans (impeller, turbine, stater). One (impeller) is rotated directly by the engine and thus moves the fluid, the fluid then moves the second fan (turbine) which in turn directs the fluid to the stater (which is a smaller fan) and thus converts torque. Shit does that make sense? p.s. I'm leaving out planetary gears, because they are a part of the fluid converters to provide more gear ratios as well as reverse.",
"Traditional planetary geared automatics have hydraulic systems which react to engine speed and load, causing various clutches and bands to disengage and re-engage inside the transmission. It wouldn't be ELI5 if i explained it much further i think. Newer planetary automatics that are controlled electronically , according to wikipedia, \"use sensors on the engine to detect throttle position, vehicle speed, engine speed, engine load, etc. to control the exact shift point.\" Automated manuals like Porsche PDK and nearly every other Dual Clutch Transmission use the same set of information to determine their shift points. These shift points are tuned in such a way that either provides the best fuel economy or the best acceleration, or both if the vehicle has multiple driving modes."
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6syx2j | How can people do accurate voice impersonations, if their voices sound deeper to themselves? | Repost | explainlikeimfive | {
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"A lot of impressions have more to do with how someone speaks rather than how they sound. Pay attention to their accent, where they pause, how they emphasize certain words, where they speed up and slow down. Now practice. Record yourself. Review. Repeat.",
"Practice, practice, practice. And other people telling you that you sound \"just like so-and-so\". It isn't hard to make sounds that you made before.",
"An important part is also the listener's brain approximating if a voice sounds just close enough to the original. Same for coverbands.",
"The inner-voice is often distorted to the untrained ear. This is the reason you'll cringe when hearing a voice recording of yourself being played back. A huge step in training your voice to sing or perform voice-overs is to train your ear. This requires hours of recording yourself and listening to it over and over. It won't be exact, but that moment of shock will no longer exist when you hear yourself anymore. So many people who imitate accents are quite used to the way their natural voice actually sounds."
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6szy5b | why do heroin addicts all have the same face? | Repost | explainlikeimfive | {
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"its the body rotting away, I don't know if you've ever touched a heroin addict, it feels weird. they are (almost) literally bone and skin. Edit: My point is that skeletons are very similar. Source: grandma was a heroin addict.",
"I think you're misidentifying crystal meth addicts as heroin addicts - but on the whole, the reason why poor(1) drug addicts look similar is because of malnutrition. It's an uncommon look these days, so it stands out - but if you look at medieval paintings, you'll see a lot of guys that look like meth addicts. Low subcutaneous fat gives a lot of definition to facial features people who are eating normal amounts don't have. (1)- Heroin addicts with jobs tend to just look a bit sweaty, pale, and have slightly out-of-focus eyes.",
"I think at first glance our brains focus on the distant eyes, loose jaws and the red/picked faces."
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6t014s | Why does your heart actually hurt when you're "heartbroken"? | Repost | explainlikeimfive | {
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"If we rule out anxiety from a heartbreaking event (which can and will cause chest pain) the answer is [Takotsubo cardiomyopathy]( URL_0 ), also known as broken heart syndrome. This can also occur when coming good happens and you get too excited (or a heart attack, stroke, arrhythmia from a non cardiomyopathic source, etc.). It causes, among chest pain, acute heart failure, arrhythmias, and rarely ventricle rupture. This syndrome temporarily weakens the heart muscle by thinning the walls of the lower portion of the heart, making it much less efficient. Almost all patients make a full recovery within 2 months of having their hearts literally broken. But to reemphases, when your chest hurts because of heartbreak, it's probably anxiety and not your heart losing the will to live.",
"> Terms such as “heartache” and “gut wrenching” are more than mere metaphors: they describe the experience of both physical and emotional pain. When we feel heartache, for example, we are experiencing a blend of emotional stress and the stress-induced sensations in our chest—muscle tightness, increased heart rate, abnormal stomach activity and shortness of breath. In fact, emotional pain involves the same brain regions as physical pain, suggesting the two are inextricably connected. > But how do emotions trigger physical sensations? Scientists do not know, but recently pain researchers uncovered a possible pathway from mind to body. According to a 2009 study from the University of Arizona and the University of Maryland, activity in a brain region that regulates emotional reactions called the anterior cingulate cortex helps to explain how an emotional insult can trigger a biological cascade. During a particularly stressful experience, the anterior cingulate cortex may respond by increasing the activity of the vagus nerve—the nerve that starts in the brain stem and connects to the neck, chest and abdomen. When the vagus nerve is overstimulated, it can cause pain and nausea. [Explained by Robert Emery and Jim Coan, professors of psychology at the University of Virginia.]( URL_0 )",
"I made a [short video to answer your question]( URL_0 )! However, if you dont want to watch the video, I'll type my answer here too. * Becoming heartbroken involves a lot of emotional stress. Emotional stress has been linked to having negative physical effects on our body too. Our muscles tighten, we have shortness of breath and our heart rate increases. * All types of pain come from our brain, it's essentially a collection of chemicals. * When we are in relationships we recieve opiods which are our bodies version of morphine. They are addictive, and seen as a pain killer and make us feel good. * Once the relationship has ended we enter withdrawl, which has been known to cause heart problems and pain in the heart. * In 2009 a study showed how the area in our brain that deals with emotional pain can stimulate a nerve in our brain stem. This nerve is connected to our chest and neck and abdomen. If overstimulated it causes physical pain and nausea. Hope you have a great day, and I hope you enjoyed the joke at the end of the video!"
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6t04d5 | how does chirality work if there are no absolute directions? | Repost | explainlikeimfive | {
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"Molecules with *chirality* are asymmetrical in some way. The details differ greatly since molecules are incredibly diverse. There are a variety of components that exist in 3d space that can be arranged, flipped, twisted, or curved in different ways. Many molecules are simple enough that they do not have alternatives, but molecules can contain dozens or even hundreds of atoms. A good example would be two gloves. No matter how you rotate or flip a left-handed glove it will never be a right-handed glove"
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6t0dbl | is Gluten really bad for the body? | Repost | explainlikeimfive | {
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"It is bad for coeliacs. Their bodies think elements of gluten are bad and tries to remove them from the body. This removal takes a toll the intestines, and they can't absorb nutrients from food due to this damage. So they avoid gluten as best they can. [Source]( URL_0 )"
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6t0gak | What happens to the tiny bugs who fly into your eye? | Repost | explainlikeimfive | {
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"Depends how tiny. I would say most of them get caught in your eye fluid and either cleaned out in the corner of your eye, or, with a larger but not huge (think mosquito sized) buy like I copped, it gets stuck under an eyelid and causes irritation until you dig it out with a cotton bud the next morning.",
"What happens to the ones that fly up your nose though? :/",
"I have been getting a lot of bugs flying into my eyes lately. Most slightly smaller than mosquitos. It's the worst though! I was wondering earlier, is it a southern thing to have this many flying insects or is it a problem everywhere?",
"Most times your eyelashes bat them away. Sometimes if you're really unlucky they go under your eyelid and you have to dig them out. Related story below:",
"I used to think they got stuck in there forever, but then I realized I just have eye floaters."
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6t0ls3 | How did it become common place for humans to call their parents "mom" and "dad" as opposed to their actual name? | Repost | explainlikeimfive | {
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"My linguistics Professor told us that even in completely unrelated languages, their early words to address the parents tend to gravitate towards a certain type of sound. Her explanation was that the lip muscles are one of the earliest muscles the child learns to use, because sucking is important for survival, so bilabial open syllables (open syllable are simple consonant+vowel combination) like \"ma\" \"ba\" or \"pa\" are the easist for a child to learn. \"mom\" and \"dad\" would then be the slightly more grown up version of \"mama\" and \"dada\". (da is a bit of an odd one out because it's not bilabial, but still relatively easy to learn compared to complex words) Even in languages in which parents are traditionally addressed more formally, they usually start out with easier \"baby\" words, and adopt the more formal terms later when the child can speak properly. But in many cases, some variation of the babyterms just stick. In short: a baby physically wouldn't be able to address his father as \"Alexander Leopold von Großauchenbach\", so they just call him \"dada\" instead.",
"We all know how addressing people works differently in different dialects of English. (mom, mum, ma, mother to name a few) most of these forms are based on language acquisition. Children go through different phases where they start using open syllables (think mah , moo, da) then later they start using repetition (mama, dada, moomoo). Nasal M is \"easier\" to learn (one of the first sounds to make) because it's a constant flow of air through the vocal cords (voiced) then out the nose. Pronouncing the p or d (which are considered plosives) requires better coordination of muscle groups since the airflow has to actually be stopped for their realization. m is easier to learn than p. addressing people, especially specifically defined people groups such as: coworkers, bosses, servants, family members, clerics etc. is incredibly complex and a fascinating part of linguistics. There are other languages where it's commonplace to refer to parents by their first name, or as already mentioned in other comments: japanese people refer to their siblings when it comes to a direct address with the japanese word for \"sister\". other languages are way more interesting than English when it comes to the direct address of people, or family members. this ain't no ELI5, but for anyone interested in that topic i suggest starting to read about the concept of politeness and language, esp. Brown & Levinson \"Politeness: Some Universals in Language Usage\" the basic breakdown of how you address someone is very complex. Brown and Levinson postulate that humans have two distinct \"faces\". A positive face and a negative face. The positive face is something like: I want to feel great and mighty and powerful. The negative face is I want to keep the stuff I have and not have anyone threaten me or my position. Positive face politeness is saying how great the other person is. Negative face politeness is saying how little of a person oneself is to make the other person appear bigger/greater than oneself in comparison. How does that work in real life tho? Well if you look at french for example, they have the \"tu\" and \"vous\" for the english \"you\" singular and plural respectively. This so called T-V-Distinction can be found in other romance languages like spanish for example. If you used \"tu\" with some total stranger or a police officer or a person that is usually respected, that's considered rather impolite and offensive. You're (according to Brown & Levinson) \"threatening\" their positive face by not adhering to societal standards in paying respect to their position in society. English only has the \"you\", but think about old english \"thou\". You've seen it in bible texts and in religious contexts mostly. Only a few centuries ago the thou got replaced by you. The politeness towards people like parents and immediate family members, which used to be addressed with a \"thou\" (informal, less social distance) got reinterpreted and children started to \"you\"(more formal, more social distance, but also respect) the parents to show more politeness and practiced the positive face politeness. This was in no way the children's choice obviously. Funnily enough we find examples of people wanting to use a different way of expressing the lacking concept of plurality when it comes to the word \"you\" in English. The lack of distinction gives rise to words such as \"y'all\" or \"yous\". I could go on and on. Such a fascinating part of language < 3 feel free to ask more **EDIT:** \"thou\" is informal and more direct, which was a deliberate choice for the church at the time. 'God and his representations (priests, clerics, bible etc.) are so close and involved in society'. It was a kind of marketing scheme in that way.",
"Ma, pa, and da are the first sounds that babies tend to make. Most languages have some variation of these syllables for their parents.",
"My Sociology of Cognition professor gave some lectures on totemism and how people across cultures dedicate special titles as a collective to people they look up to, whether it's a community leader of some sort or a person within the family depending on the pecking order. Mom is mom, Uncle Joe isn't just Joe but mixing uncle and Joe is ok because not as high up on the respect order as the parent. Kids raised by grandparents might call the grandmother mama since they play that roll. All societies have pecking orders and status symbols, etc. It helps us cognitively sort the world around us. Where this originated I'm not sure, but the idea he was relaying is that we all, as collectives in society and as individuals, need to make sense of the social order around us by sorting people with signs of status and respect. We say \"hey doc\" to doctors but we don't call them by first name, generally. We say \"professor\" rather than just their name, maybe \"professor (last name)\". Some adjuncts are ok with \"professor (first name)\" but my Sociology of Knowledge professor earned her PhD mid-semester and people started calling her \"professor (last name)\". There's no society out there without these designations of status, and it makes sense. Obviously mom has a higher status in one's life than the mailman, no offense to the mailman. I don't know of any society where it's acceptable or normal across the board to call mom and dad by their first names only, but I might be wrong. Social sciences are fuzzy and my area of focus is more on current dynamics because I'm also studying public policy and political science but that's what I've gathered so far. Hope this sorta maybe answers the question along with the other gems in this thread. There's no one exact answer I think, because even cognitive sociology is theoretical rather than full blown empirical, compared to say, chemistry and whatnot.",
"People are addressing a question of ontogenetics, i.e. why it's easier for individuals to say \"mom\" and \"dad\" earlier than arbitrary names. But OP's question is actually a different question: (s)he's wondering why this became cemented even later in life. In other words, OP is asking a question about why we stick with those words *instead of* actual names. I'd actually like to question an assumption in OP's question, which is that \"actual names\" for individual persons (that they kept throughout their life) predated words for \"mom\" and \"dad\". It's much more likely that humans had \"words\" (or conventionalized noises) for referring to or getting the attention of their caregivers long before we had conventionalized names.",
"I was actually looking into this just yesterday! The answer is that what you call your parents, siblings, and what we consider extended family differs incredibly from culture to culture. There's a whole segment of anthropology devoted to Kinship systems. Concepts such as descent lines, lineage, consanguinity (people you're blood related to), affinity (people who marry into family), and kinship that is tied to neither blood or affinity are different across many cultures. Most kinship systems have words/ titles for parents, but they vary greatly. In some kinship systems, you call your father dad, but also all his brothers are also dad (same with mother and her sisters). In some cultures, every person of a certain generation in your family is dad. In some, your father's brother's son is your brother, but your father's sister's son is your uncle. In some aboriginal tribes, the words cycle through generations, so your great-grandmother is called your daughter. The titles can be honorific, but mostly are used as a label to show your place and role in a society/family. In western society, Dad and Mom take care of Son and Daughter. The relationship between Dad and Son is different than the one between Uncle and Nephew, and Grandfather and Grandson, but those rules aren't ubiquitous across all cultures. In more stratified societies, even more divisions exist to qualify your relationships and place in the family. For example, in Sudanese culture there are 8 different words for cousin based on their relation to you in the family. If I understand it correctly, in some aboriginal tribes everyone is considered family and there are strict rules about which moms can marry which dads, and if you interact with a certain tribe a lot they might assign you a mom or dad type (skin names) depending on if they see you as part of their society. To answer the original question, we call them different names to signify their place in the family unit, but what family units look like vary incredibly across all cultures. How the culture evolves and understands the family dictates the actual words used and what they mean. Finally, in Western Culture we continue to use these titles in place of names as a sign of respect, but that isn't a given across all cultures.",
"When I was a wee lad, I thought your name would automatically change into mom/dad once you got children. Also, a baby would come out through a bellybutton. It was a simpler time.",
"It has to do with linguistics and dates back to the origin of language. Mama and papa are two of the simplest sounds that humans can utter and and that's why it's almost always a baby's first words. They can make the sounds just by pushing air out their mouth and opening/closing their lips. That's why you see such similar words for mom/dad in other languages (especially ones that originated from Proto-Indo European regions). When humans first developed the capability to speak, it's postulated that names of objects were assigned based on natural phenomenon i.e. to reference a dog you would make a barking noise, to reference the wind you would make a whistle, and to reference one's mother and father you would use the name that babies intrinsically address them as using their relatively incoherent babbling-mama and papa. Hope this helped!",
"Apologizes for this being long. The new born’s brain is basically a blank slate, like a brand new CPU without any software, so they have to learn how to verbally identify who and what is Mom or Dad before they can use the vocal cords to say words correctly (it’s not just mimicking words: the infant has to learn to identify what words means and what reactions they get from parents when learning to speak in order to know if they’ve identified the right word for the right person.) They also have to practice and learn how to control their body while trying to use the muscles for verbalizing words with brand new vocal muscles beyond just basic crying and cooing to gets parents attention. Look at it this way: Just as infants practice walking by hanging onto objects and cruising along the edge of furniture while standing, they do this by learning how to balance their bodies on their own two feet before trying to take steps on their own; Infants also practice using their voices to make words in the same way. Babies “talk” to us all the time (only we don’t recognize the efforts until the words are very clear,) The infant makes words and as parents we eventually react to the word. I laughed a bit at other kids when voices were cracking as they grew up. How many times have you seen a video of a baby trying to talk that mom or Dad recorded, but the sounds re highly indistinct… but both parent swear is very clear? While the Mom speaks she may use the chosen word for Dad and the more times the Mom spends during her time talking about Dad, the sooner she is going to recognize when the infant is actually saying the chosen word for dad correctly... The more often the infant is acknowledged by attempts to make the correct word the sooner the infant actually uses this word loud and proudly. It was a shock for me when I distinctly heard my child correctly say “momma ” and it was imprinted on me for life! Even though I could hear my child using the word for me in his babble while crying and I knew when he was just practicing making sounds. It takes a lot of effort to make word sounds with their inexperienced newborn vocal muscles (even though the infant has heard the language often enough while still in uterus to know it’s own parents language and can differentiate it’s parents dialect shortly after birth The part of the brain responsible for coordinating the two halves of the brain is the corpus collosum. The ability to use right brain (creativity and imagination) and left brain (logic) simultaneously may well have been what made Einstein a genius. Each child is basically a genius in the respect of learning how to speak compared to lower mammals … learning to speak requires the active integration of both sides of the human brain be focused to make a sound as speech and memorize word meanings. The corpus callosum contains highly packed bundles of neural fibers which are found in humans and other high order mammals (apes) and allows the two hemispheres to talk to one another. The infant has these bundles of nerve tissue in place by 34 weeks of gestation and it is interacting and both sides are coordinating activity while the infant is still in the womb. It is thought that dreaming and use of memory is what is required to trigger conscious awareness to control language in the infant, yet the infant has been practicing verbal sounds since birth - usually while also practicing body control (turning he head, moving hands, etc.) I swore I could hear my unborn infants trying to talk to me while I rested in bed in the evenings and it was quiet, but I learned later that scientist did “video recorded ultrasounds of fetuses during the third trimester, where they startled the baby with a low-decibel noise against the mother's abdomen and caused the fetuses to display traditional crying behavior, such as opening their mouths, depressing their tongues, and gasping irregularly. So yes, infants do practice speech and crying while in the womb and that was probably what I heard. The verbal control and constant verbal practice from babies (which we as adults tend to ignore) is called babble. My sons spent their ‘free time” babbling constantly, as well as constantly listening. My sons both said “daddy” months before they ever said “mommy.” and this was because I was at home speaking to them more often than their father had time to. But from the adults as the infant continues to practice word sounds more frequently some adults get annoyed and we find we are now telling the infant to “shut up.” Humans are the only species who tend to juvenalize our pets as well as our own children for as long as possible. My sons are my sons their entire lives. My two dogs are trained to respond to me as \"Mom\" and at times i swear I can hear them saying \"mom\" to me. (my sons don't hear it, but i do!) My dogs remain juveniles as long as they remain my pets - they get babied and treated as young babies, though both are seniors now they are my babies. And we humans demand our children respect us by calling us Mom or Dad when speaking to us (I would have been backhanded as a child if I ever tried to call my parents by their real names - though I fully knew their names by the time I was at least 3 years old.) The use of name substitutions is part of human culture. I identified my aunts and uncles by using the words as part of their titles \"Aunt Suzy and Uncle John.\" I had to learn to introduce my parents to others by their title as well 'These are my parent, my Mom \"Mrs. Joan Survivor\" and my Dad MR. Victor Survivor.\" Don't forget, since we keep our children juveniles all their lives, we insist of being called by our genetic titles all of their lives as well (representing my love for my parents - nobody else in this entire world ismy Mom or my Dad. I'm not a Catholic so would never call a priest as 'father.' Hell, I even Capitalicize the words in writing to honor my parents because I'm so socially indoctrinated.",
"The reason parents sometimes call their kids \"son\" or \"daughter\" is because we get the names mixed up. > Come here, Robert, Benson, James, Maximus, whoever, you, get over here! We've all done that, right? I remember I was trying to call the name of a kid who was working for me once at a BSA camp and I cycled through the names of the seven other staff members in my area (who were all kids) before hitting his name. It's incredibly useful to just have one word that can refer to all of your kids, or maybe all the kids of one gender or whatever. And so we return the favor by calling our parents by the loving epithet of mom or dad or papa or whatever. And so the cycle continues, generation after generation.",
"The sound \\ma/ is the easiest sound for human beings to make, and occurs I every recognized language on the planet. Being that early humans spent the majority of their time with female caretakers, the sound\\ma/ was quickly associated with these females. The second simplest sound in language is \\pa/. Linguistics is very interesting if questions like these are on your mind.",
"First sounds children can make. Ahhhhh. Close mouth and hum. Mmmmmm. Close mouth, then open. Maaaaa. Ma. Ma ma. Common in many languages including Sino-Tibetan family.",
"As others have said, the sound \"ma\" or \"mamamama\" is related to the baby's need to feed and therefore the mother's breasts. This is also where the root for mammals and mammaries comes from... it's all related as far as I understand it. Makes sense that the baby saying \"feed me\" ie \"mamama\" becomes the word for mother. The real question is where does \"DAD\" come from! lol",
"I think it goes way, way back before written history. What many do not know or maybe realize is that people lived in groups, without individual dwellings. They knew whether knowingly or unknowingly that sex lead to children and that certain traits were passed from 'father' to 'son' even if that was a 'spiritual' trait. Women used to have sex with the hunters, and the best hunter was usually the busiest man, and he also was usually the guy who didn't live the longest. Because of this trend, women who got pregnant would pick from a group of men to be their 'partner', those who either didn't hunt or weren't that great at it, but they were good at other things. This was also good for the group, as it promoted less aggression from the males and it gave the women help in taking care of the young children. And there were a lot of young children, as many did not make it to adulthood. This became the family unit. I would imagine that ma and da were a way for the child to identify their parents, and validate it as a family group. It would probably also be easier to say, depending on whether or not they had given each other names at that point. This would seem to be the logical choice of defining family, as children would take care of parents, when the parents could no longer provide. And, when moving as a family, you couldn't accidentally take another person's child, as the child would know who their ma and da was very early on. And you could easily ask even a very young lost child who their ma or da was and they could point them out. I think it was such an easy and logical way to define family that it was passed on through generations and cultures, until today. And, even today we tend to define the roles even further by birth parent and parent.",
"They are titles used for respect. Brother and sister are not used in the same way as they are one's peers. The respect thing also includes Aunt and Uncle, but not cousin, again, because cousins are one's peers.",
"My neighbors had two children about two years apart from each other. When they thought they were doing well with teaching the oldest how to speak, it reverted back to babbling with their younger child and the two created their own language.",
"when we're children, we make noises. adults have perceived those sounds as \"pa\" for dads, \"ma\" for moms, and \"ba\" for food/bottles - which has to do with the psychology of humans and how i ears perceive. so, partly, babies name their parents \"ma\" or \"pa\" and partly, adults feel rewarded by the sounds babies naturally make.",
"Just food for thoughts~ Mom and dad is basically a title just like Commissar, Vice president, Chief, etc. Its used to define your relationship to one another on a social level and to place yourselves as pieces on the social board game. By determining who is mom and dad (even if not biologically being mom and dad) you determine your relationship to one another socially and emotionally, and as such it serves to create a bond between you.",
"The question has a problem. It assumes that there was a time were we would call our parents by their names. Both names, and the way we call our parents, go back a long long time. AFAIK there isn't a clear way of knowing if one came first or not. It makes sense that we wouldn't need names for our immediate family. When I talk about my mom or my dad I am talking about a specific person. When I talk about my uncle, or my niece, it's harder to map who I am talking about specifically. Still when we are born we only care about our parents, and so only need to name them, not by their real name, but something easier. Babies are really bad at speaking, they're just learning, and so can only form very simple sounds. The first sounds they make are things like \"gah\" or \"ba\" or \"da\" or \"o\" or \"meh\" etc. Parents want their kids to quickly learn to call for them, so they give themselves simple names that can easily be formed by the simple sounds, but won't be accidental: \"dada\", \"mama\", \"patah\", \"nana\", \"babo\", \"naan\", \"tatah\", etc. This are different ways of saying mom or dad in different languages. As we grow we still call our parents the same way, why would it change? Most people only deal with one mom and dad during their childhood. So we just keep calling them like that."
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6t0mut | How are medicines discovered? | Repost | explainlikeimfive | {
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"Medications work by initiating a physiological response in the body. It is not possible for any chemical to make the body react in a way the body is not capable of reacting in to begin with. So, to find a medication to treat a disease or symptom, scientists must: 1) figure out what is causing it 2) figure out what body processes can address it 3) find a chemical compounds that can initiate that process on the body with minimal side effects 4) figure out the best method of delivery to get the correct dose to the correct part of the body It is a long, complex and expensive endeavor (new drugs take 10+ years and upwards of $5 billion from start to finish) Its basically trying to reverse engineer a key for a complex lock."
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6t0y72 | Bayesian probability in very simple terms? | Repost | explainlikeimfive | {
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"Bayesian and frequentist are ways of *interpreting* probabilities. A frequentist probability is a relative frequency. In other words, the frequentist probability of some event occurring is the fraction of times in which it would occur, in the limit where the number of trials goes to infinity. A Bayesian probability is a subjective \"degree of belief\". It depends on your prior knowledge, hence why it's subjective."
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6t3cek | How does global debt even work, and how do nations pay off their debts? | Repost | explainlikeimfive | {
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"Government debt exists as bonds. Bonds have a fixed payment schedule, they pay interest over their life and their face value at maturity. A nation pays back it's debt by following the payback schedule In the US the vast majority of the debt is held by private citizens with most of that existing in retirement funds. If your parents have bonds in their 401k then they own US debt A nation never needs to get out of the red, as long as they've been paying on time they can just issue more bonds to cover the now due bonds so they're only out the interest. Inflation also cuts into the real effect of the interest, if interest is 3% but inflation is 2% then they're only out 1% of the total debt which is very manageable. If that debt leads to 2% growth they're ahead by a lot You also don't want the US to get out of the red. It would slow down all government projects due to funds being unavailable, and crash the global market due to a sudden lack of safe bonds to invest in, all in all very bad"
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6t4mrq | how do baby chicks not imprint on each other? | Repost | explainlikeimfive | {
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"They only focus on animals much larger than themselves. It is genetic. They look for moving creatures much larger than themselves. In nature, if it is not mom, they are a meal anyway."
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6t809j | Why can we capture images of celestial objects which millions of lightyears away but not capture detailed images of Uranus or Neptune? | Repost | explainlikeimfive | {
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"We're taking some fabulous new photos of Jupiter, but only because there's a fabulous new space probe *at* Jupiter. (Juno). When a similar mission orbits Uranus & Neptune we'll get some new images. Our current images of Neptune (Voyager 2 flew by in 1989) & Uranus are from brief flybys from probes on thier way out We **can** take pictures of Neptune from orbit of Earth (such as the Hubble). Here is how the Hubble sees Neptune: URL_0 not a great image, is it? Well here's why images of Neptune & Uranus are so junk: They're not very bright. Taking an image of a local planet is hard because thy do not make light, they are far from the Sun so they do not reflect much light, and they're moving faster (relative to Earth's own movement) than something much farther away. A distant star or galaxy **is it's own light source**, are waaaay bigger than any planet, and don't wiggle as much during the image exposure."
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6t82ae | How do graveyards make money or sustain themselves after they are full? | Repost | explainlikeimfive | {
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"It's pretty complicated and gross. Graves are turned over in some countries. After around 100 years, grave sites lower caskets and bury new bodies over them. In some countries rights are perpetual. URL_0"
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6t9m2g | What causes time to move forward? | Im reading this book called The Physics of Time by Richard A. Muller, (highly recommend reading) and he states that time moves forward because our current entropy state is so highly improbable. Can someone eli5 this for me? | Repost | explainlikeimfive | {
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"Thank you for this question, this is really one of my most favourite aspects of physics: Let me start with the Big Thing, please stay with me: Time does not exist as actual dimension. Time is an illusion of \"stuff happening in the physical world\". Imagine yourself to be in a room where no outer stimulus comes in. No light from a window, no sound from the other side of the door. Now, there is also nothing in the room itself that changes, no water tap with dripping drops, no breeze from a ventilator, no dust settling, no nothing. How could you tell that \"time\" passes? You feel your own heartbeat, you feel your breathing. If you wait long enough you feel the need to eat, to drink, to sleep, to go to the toilet. If you wait long enough your nails and hair grow. But let us assume for some reason you do not have to, you just sit there and... sit there. How could you tell \"time\" passes? You cannot - unless you move your hand. Unless you get up. Unless you take an object and let it drop so it falls down. Now you suddenly can tell *something happend*. A moment ago you were sitting on the chair, now you stand. The physical space has changed and there are two states, one before you got up and one after. If you let something drop you create a whole lot of differing physical states in space: you have a thing in the hand, it drops, it drops further, it drops faster and faster and faster... and it hits the ground and rolls under the bed. By observing what happens in the physical space you can tell a passage of what we now call \"time\". You can also tell that \"the time it took you to move your hand was shorter than the time it took you to walk through the room\", this means you somehow start to quantize a new observable beyond mere \"where is an object in the space I am in\" in the universe: time. Our observation of time is very unprecise. Everyone knows that \"time flies if you have fun\" and stretches and strechtes if you are bored - on the other hand in our memory the day where we had lots of fun and did a lot of thing was much longer than the one we just waited out. To remedy this we build machines that repeat the same movement in space as precise as we can. A pendulum swings. A water drop dripping down from a defined opening (i.e. a water clock). A spring is wound up and makes some axis turn which moves a digit. We then count the repetitions and say \"Ok, 60 of those is a minute, and 60 of those is an hour\" or similar. The most simple clock is the sun, we say \"If it is right above and then again, we call it a *day*\". If a season repeats because earth fully turned around the sun we call it a *year*. So far so simple. We get the impression time exists because \"stuff\" happens around in the universe - and that includes our cells that grow and die and finally we grow and die as that is just chemical (fundamentally physical) proceedings in space. Now for entropy: --- In the most simple approach entropy is a measurement of \"Order in the Universe\". In very broad strokes: The higher the entropy the less ordered is the universe, meaning there are more states. A piece of wood has a lower entropy than the burned piece of wood. Now, in physical space things only happen *on their own* where the entropy is increased. So a ball falling down happens on its own because it increases the entropy. You have \"ordered\" energy in the form a ball lying on a table. If it falls down it loses that energy by disturbing all the air molecules it falls through, it hits the floor and makes all those molecules in it vibrate, the ordered energy from the ball on the table is now very, very unordered all over the room and this means: the entropy in the room has increased from state 1 (ball on table) to the new state (ball has fallen down). We call this \"Energy is scattered all over the place and thus entropy increases\" as \"time moves forward\". Because, on their own, balls do not fall up back on the table, cells do not \"undie\", a set of fallen deck of cards does not order itself again. Because that would require the entropy in the room to decrease again and the room taking a \"more ordered state\" (meaning the cards are not lying all over the place but are nicely on a stack, possibly in a specific order, i.e. all colors together etc). I wrote that entropy does not decrease on its own but you very much could go around and pick up the ball or the cards again, you might even order them again and put them back on the table. So you cheated entropy? You restored the highly ordered state of energy again? Yes, indeed, you did. But by that you increased the entropy in the room due to moving around, calling energy from your muscles and turning them into heat that now is in the room. You ordered the system of \"ball and table\", but the *total* entropy in the room (universe) went up - and as such you can tell that \"time has passed forward between state 1 (deck of scards scattered) and state 2 (deck of cards neatly on the table)\". Now one thing missing from your question: Muller writes about \"improbable\". Imagine the room has a billion billion billion possible states where the ball is on the floor, the air molecules it shoved aside are scattered, the molecules in the floor have swung and all the ball's energy has dissipated as heat and increased the entropy. Of course (yes, of course!) there is the hypthetical case where all the molecules are just randomly happen to just move in the reversed direction, all the air goes back where it was, all energy, by pure chance, transfers back in the ball and it comes to lie back on the table. That totally can happen and in that case you would observe the ball... uhhh... falling (?) back onto the table. In that case the entropy in the room (universe) would indeed have decreased on its own, you now had a - from an energetic point of view - more ordered state. Time would have moved \"forward\" but the entropy would have decreased. Yes, that is possible. It is just that the chance for that is 1 to a billion billion billion so we simply do not observe that in the macroscopic world. And that means \"it does not happen\" but if you are mathmatically correct, as a physics book should be, you say \"it is highly improbable\". --- The question posed is answered as good as I can, but lets finally get for a very short glance into Einstein's relativity: based on what is written above Einsteins quote \"Time is what clocks measure\" should be very clear by now. A clock just repeats something in physical world and we count how often that happens. If something in the physical world now - please excuse this expression, but it hits home - screws with how we observe this \"stuff happening in the physical world\" it also and automatically shifts what we consider, percieve and measure as *time*.",
"First of all, you have to understand that there is no scientific consensus on this idea. So don't take it as \"this is the way things are.\" Imagine you have a glass of milk on the edge of a table, and you tip it over. It spills on the floor. This happens every time. What about the opposite? A puddle of milk on the floor jumps up into the glass, which then \"un-tips\" itself. This doesn't happen very often at all. In fact, no one has ever seen it happen. If you saw a video of it, you'd say, \"That video is time-reversed!\" That's what Muller means by \"time moves forward\" -- he means that some things, like spilling milk, only seem to happen in one direction, and not the other. The thing is, even though the \"reverse spill\" never happens, it doesn't actually violate the laws of physics. How is that possible? Well, the floor actually contains quite a lot of energy in the form of heat -- all the molecules in the floor are vibrating back and forth randomly. If, by random chance, they happen to vibrate in the right way, they contain more than enough energy to \"pop\" the milk into the air. If they're really lucky, the milk will even land in the glass. Similarly, the molecules of the table are vibrating, and they have enough energy that if they happen to vibrate in just the right way, they can bump the glass lying on its side and tip it upright. I think we can all agree that the \"reverse spill\" is an extremely unlikely event. It requires quintillions of molecules to be moving in *just the right way*. Here's the really counterintuitive thing, though: in a sense, the reverse spill is no more unlikely than the regular spill! This is because, for every possible spill of milk, there is exactly one possible reverse spill. In other words, imagine that an all-powerful being decided to create every possible universe that obeys the laws of physics. For each universe, there would be another universe that is exactly the same except in reverse; this violates none of the laws of physics, so it must be among all the possible universes. And that means for each universe where milk spills, there is another one where it unspills. So, if both the spill and un-spill are allowed under the laws of physics, and they are in some sense equally likely for random arrangements of particles, why do we see spills all the time, and never see reverse spills? This is the question Muller is trying to resolve. One possibility is that the universe is not a random arrangement of particles. Maybe God created the universe so it would have spills and not reverse spills. But Muller is making an argument for a different explanation that doesn't rely on God carefully designing the universe. His argument is this: In all the possible universes, both spills and un-spills are extremely rare -- most of the possible universes don't even have milk, let alone glasses or tables -- and equally so. But they are rare for different reasons. Un-spills are rare because all the molecular vibrations have to happen just right, and so on. But regular spills are rare primarily because *most universes don't have full glasses of milk to spill in the first place*. Once you have found that rare full glass of milk among all the possible universes, a spill is no longer unlikely. So his argument is basically this: Milk spills rather than unspills because we happen to live in one of those improbable universes where there are full glasses of milk. And, in general, if you can think of a process that only goes one way, from start to finish, it's because we happen to live in one of those very improbable universes where the starting conditions exist.",
"He's trying to give purpose to an observed function we don't understand. There are far more scientists who would disagree or argue over the concept. We don't currently understand the universe, and as far as we know there is no purpose of its features. Primarily, we just note if the function did not exist, the universe wouldn't exist in its current state, since time is required for reactions to occur. However, that's as astute an observation as radiation is often a bi-product of a nuclear reaction. The only difference is we don't try to give a \"purpose\" to why radiation is expelled, we just describe the occurrence. Perhaps due to the familiarity of time we try and understand \"why\" it's there, but that isn't how the universe or science works. It just \"is\". Additionally, describing time as moving \"forward\" is probably an incorrect way to quantify it, since that implies a relationship from its current state to its previous, even though they do not interact with each other. e: It's also arbitrary to note how our current state of entropy is \"improbable\". We have nothing to compare it to. We can't philosophize the universe at such a scale, we simply don't understand it enough.",
"Weird thing about physics. All physics works exactly the same run backwards in time than forwards. Infact if I could magically record the exact motion of every molecule around you for some time, and then do something to the motion of the molecules so the did the same thing in reverse, you wouldn't be able to tell the difference between that happening in reverse but forward in time, or if you were moving backwards in time. When you put some milk in your coffee there's no physical reason it shouldn't unmix, or for that matter that it shouldn't blink in and out of existence. There's no physical reason we can describe that the past is any different from the future. It obviously *is* different. If you spill that coffee on the ground it won't spontaneously unspill halfway to the floor even though there's no reason why it couldn't. Entropy however provides an argument for why this must be the case, even if it doesn't explain why. In short, entropy is basically the one thing that isn't reversible. If you have something in an ordered state, it will only become less ordered. Entropy always increases is why your the milk in your coffee won't unmix. The universe doesn't really make physical sense without that rule, but it's a propery of statistics, not physics. However if time went in reverse you could watch your coffee unmixed the milk go back back in the carton, the oils go back into the bean, the beans ungrind, etc. And because physics doesn't care which direction something is moving through time, this would be exactly equivalent to entropy decreasing.... which can't happen. There's one small issue with this argument. It's enough to argue that time must flow in *a* direction, but not which. The past and the future should look similar and thus there should be no inherent preference to which time moves towards. We need make one more claim for a preference towards the future: In the past the universe was in a state of extremely low entropy. If so the past and the future would look very different. Turns out, as best as we can tell that's the case. The universe were highly dense in the past, [big bang cosmology]( URL_0 ) etc implies really really really low entropy."
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6t9rsd | Why is it that the Moon's gravity effects our tides, yet if a satellite were to fly in between the Earth and Moon it wouldn't get effected? | Repost | explainlikeimfive | {
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"Satellites are actually impacted by the gravity of the moon, but drifting a few meters in orbit isn't that big a deal."
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6tafdn | what happens if I fire a gun in space? | Repost | explainlikeimfive | {
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"The bullet will leave the barrel at high speed, but a slower speed than it would on Earth. You will begin traveling backwards since you absorb momentum to cancel the momentum of the bullet The bullet will continue to move at the speed it left the barrel for a long time. It will slow slightly due to particles it encounters in space but there are so few it will be a long time before it slows due to friction. Depending on what direction you shot it, it may speed up or slow down due to the effect of gravity, the bullet is now in a ballistic trajectory. If you shot it in the right direction at the right speed it will achieve orbit of the most dominant object in the area, otherwise it will either leave that objects sphere of influence or be captured by it and fall to the surface",
"Yer not alone in askin', and kind strangers have explained: 1. [ELI5: Gun fired in space. ]( URL_0 ) 1. [What happens when you fire a gun in space? ]( URL_5 ) 1. [What happens if you fire a gun in space? ]( URL_6 ) 1. [ELI5: what happens if you shoot a gun in outer space? Can a country \"claim\" a portion of space as a territory? ]( URL_2 ) 1. [ELI5: what would happen if you fired a gun in space? ]( URL_4 ) 1. [ELI5: What happens when a gun is shot in zero-gravity? ]( URL_1 ) 1. [ELI5: What would happen if you shot a gun in space? ]( URL_3 )"
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6te7jk | Why is hot water a bit white when it comes out of a tap ? | Repost | explainlikeimfive | {
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"Dissolved air bubbles. When pour a glass of hit water, it often has air trapped in it. If you pour more slowly, or let it settle, you'll see the water looks clearer. Small air bubbles appear white because they contain many reflections of the environment.",
"Tap water often looks whitish due to tiny bubbles of air. Let sit for a few minutes and it'll probably be gone. (air dissolves more readily in cold water, this is probably why you don't see it)"
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6tfj49 | How is Hiroshima inhabitable, but Chernobyl is uninhabitable? | Repost | explainlikeimfive | {
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"Hiroshima had around 140 pounds of nuclear material in it, Chernobyl had over 800 tons of nuclear material.",
"I looked up the difference between a nuclear reactor accident and a nuclear weapon, and [this article]( URL_0 ) has the best explanation. I've spent a good deal of time reading the timelines of Chernobyl and Fukushima, so some of this comes from that past reading. I'm not a subject matter expert, just curious. Basically, when a nuclear weapon is detonated as an air burst, or at high altitude above the target, then the dust from the ground and destroyed buildings doesn't mix as much with the radioactive material and thus doesn't become radioactive itself. Air burst is the common goal of attacking targets with nuclear because it maximizes the exposure of the explosive force to the ground. Also, a bomb is an uncontrolled reaction which uses up the radioactive fuel instantly. In a reactor, the controlled reaction has fuel which is meant to be used over time. The fuel has an intentionally long life of radioactivity. Furthermore, there are other elements of the control system which become contaminated by radioactivity, namely the control rods, the cooling water, and the components of the system that contain the reactor. All of this stuff remains radioactive for years after being exposed to nuclear fuel. This is planned, and honestly the industry still doesn't have a long term disposal plan for all of this waste. Then, in a meltdown situation, the control system has failed, and the nuclear fuel reaches high enough temperatures that it melts together, preventing any more control of the reaction. Temperatures continue to rise as the reaction proceeds uncontrolled. The fuel \"melts down,\" literally, seeping through the case of the reactor as it melts through. In Fukushima, they think that the pile of molten fuel has re-solidified on the concrete floor of the building. The radiation continues to be so high that robots sent in to film and transmit video fail after exposure to this radiation. So then the only thing to do is to wait for the fuel to cool and to spend itself out in the reaction process, and hope to God that it doesn't melt through the concrete itself and get into the ground. Theoretically(most likely not in Fukushima anymore), the fuel pile could melt through the concrete, the ground, and then begin vaporizing the groundwater, shooting radioactive steam out in whatever direction has the least resistance. One last effect which happened in Fukushima. The reaction releases hydrogen gas, and that gas built up in the building. It exploded and blew apart the building itself, which then exposes circulating environmental air to the reaction. This would increase the range at which the area would need to be cordoned off to ensure people are not exposed to radioactive air. In case this terrifies, know that modern reactor designs are much better and safer. Chernobyl was an unforced error by foolish, politically appointed managers of the reactor who bypasses safety protocols to impress their superiors. Fukushima is a tragedy of exceeded design parameters as far as flood control and effective backup power for cooling systems. The key is to learn lessons from these tragedies and make preparations at existing legacy reactors to ensure meltdowns don't occur. And of course build only the better kinds of reactors in the future."
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6th303 | How come animals the size of Dinossaurs never inhabited Earth after Dinosaurs were extinguished? | Repost | explainlikeimfive | {
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"Because previously the earth's atmosphere had a much higher concentration of oxygen in the air meaning that the respiratory system was able to absorb enough oxygen for aerobic respiration in all the cells of the larger animals (that's why you hear about the massive insects that lived then, the high O2 concentration allowed them to respire more and so inevitably grow to larger sizes."
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6thefb | Why isn't all money in coin-form? Don't coins last longer and aren't they much harder to counterfeit? | Repost | explainlikeimfive | {
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"Yes... but aren't they also a lot heavier, bulkier, and harder to transport? Also, part of their difficulty in counterfeiting is from the expense of doing so. You may say to my above question that we could make it less bulky by making $5, $10, $20, and $100 coins. But for $100 a piece, a criminal might be more inclined to find a machine that can press coinage and make fakes. For $1 max, it's not worth it.",
"Coins are not as convenient to carry around as bank notes. Right now I have about 20 notes of various denominations in my wallet, but whenever I get even a few coins I don't know what to do with them. I try to get rid of them as fast as I can! The durability is not an issue since new notes are created and old ones retired routinely. And a good thing too, as they don't last very long ( URL_1 ) Note that it costs the mint about 8 cents to make a quarter, while the fed say's it is about 12 cents for a 20 dollar bill, so cost probably not the driver. (Source: US Mint 2016 annual report, and this [page from the fed.]( URL_0 ) )"
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6tirec | why does scraping scissors against a strip of ribbon create a curled strip of ribbon? | This also happens with hair when pinched and pulled. | Repost | explainlikeimfive | {
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"There's a really handy sci show video about this topic. It's due to a force called Yield where a certain amount of force will deform something permanently. But only the outside of the ribbon is deformed and stretched making it curl away from that side URL_0",
"The friction on the band between, say your finger, and the sharp scissor blade moving against the ribbon (being held in place or pulled opposite) with enough force (stretching) causes the fibers in the ribbon to deform and shorten because of exceeding the molecular elasticity and therefore pulls on the strip from both sides where its elasticity has changed enough that the structure of the fibre itself is actually altered Simpler answer: When you apply enough force to a ribbon to exceed the force that keeps the fibers intact, the fibers deform around the area you applied the force to, but not around others, so now some parts of the ribbon are actually different length than others, making it curve. EDIT: Made it more ELI5 as I agree with /u/Vardelet"
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6tmyb3 | why do we sometimes stick out our tongues slightly when we're concentrating hard on something? | Repost | explainlikeimfive | {
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"Certain portions of the human brain are double-tasked. Ever wonder why you look up or down while doing difficult math? Eye movements and problem solving are both happening in the same part of the brain. ( URL_0 ) It's likely the same thing with sticking your tongue out. the part of your brain that's concentrating also has some other job that just kind of happens randomly while your brain is putting all resources into one task.",
"Tongue position also can have a big impact on strength. Here's an [ELI5 explanation]( URL_0 ) (with scholarly article link). Essentially, the tongue and brain are wired pretty tightly together, from a nerve standpoint. It's pretty cool!",
"I've read somewhere before (and currently on much break can't look for source) that the nerves that run through our hands and the nerves that run through our mouth connect to the brain in the same spot. So when you are completing a fine motor task with your hands you will often stick your tongue out or bury it in your cheek as a kind of side effect.",
"I'm surprised there's no comments about the level of concentration and competitiveness that Michael Jordan played with and how he's known for always having his tongue out before or as he's doing some ridiculously acrobatic stuff.",
"Also why do we strain our face when exerting force with our arms or legs? Sometimes I realize I'm doing this while working out or whatever and will consciously try to keep a straight face.",
"I understand that sticking out the tongue is a refusal sign that babies use when they don't want to feed. Something similar is used sometimes by adults when they want to refuse something, make an expression of disgust, or, as in this case, to block things out so they can concentrate. Desmond Morris has some pretty interesting books on body language, which is where I learned this.",
"It's a natural display to others that you are thinking and do not want to be communicative. No one talks with their tongue out and mouth closed, so it means \"im concentrating, don't expect me to speak\".",
"This is called an overflow movement, and is seen more often in children with ADHD and, I believe, autism.",
"Ever hear of guitar face? A lot of people make a face when doing a solo on a guitar, probably happens when the brain is stimulated on both things: guitaring and face movement. P.S. this face is not only limited to guitars, it can happen with other instruments too. :p",
"The creepy old lady cashier at the Circle K in the neighborhood I grew up in would always have her mouth open with her tongue out swishing around aimlessly while ringing you up. Damn it was creepy.",
"Your tongue uses a lot of brain power to move around and do things in your mouth. By sticking it out and holding it still, takes less brain power and keeps brain from being distracted while you focus."
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6tnwar | Why are gas prices allowed to fluctuate multiple times a day, when other shelved products remain at a constant price for a year or more (with the exception of occasional sales) | Repost | explainlikeimfive | {
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"> I don't understand how this is able to happen? The fuel being sold has already been purchased at a set cost. Regardless of current events, that fuel was already processed, purchased, and delivered, so why isn't it being sold to recuperate that original purchase? OK. There are 2 issues in there that you are having. First of all the government does not control what stores sell the product for. Stores can adjust their prices however often they want to whatever amount they want. Customers then make the choice if they wish to purchase or not. So to answer \"how can this happen!\" the answer is that these are private companies that can do whatever they damn well please when it comes to selling their products. The other thing you mention is that the selling price of an item should be somehow tied to the cost to purchase that item. If I buy a $100 thing I should sell it for $110 or $150 and not $1,100 because that would be unreasonable. I understand this thinking, but it's flawed. The selling price of an item is tied only to the demand for that item and the supply of that item. How many people want it and how much of it is there available. In an ideal world, a store would increase or decrease the selling price until the number of people who want to buy (at a price) exactly equal the amount of an item that's available. This maximizes the retailer's profit. Let me put it to you another way. Let's say I sell a thing. I'm the only one who sells this thing and while my overall market is limited and small I'm the exclusive supplier so I do ok. I sell 100 things per month for $100 and each one costs me $50. So I bring in (100x100) $10,000 in revenue and have $5,000 in costs. I make a decent living selling these things. One day I decide to undertake a project. I discover a way to make these things for cheaper. It took me years and years to discover this process but now I can make them for only $10 rather than $50. Now, who should benefit from this discovery, me or my customers? Remember it's a very niche product, it's not like I'll sell more if I lower the price. only 100 people per month want this thing and that's all I'm ever going to sell, 100 per month. I believe that I should benefit from all the work I put into developing this new process. So I keep my price the same, sell the exact same number of things per month ($10,000) worth, but now I only have $1,000 in costs so I make much more money. This is all to point out, the cost of an item and the selling price of that item are not related values. As long as the sale is profitable the retailer will price an item where they believe they will maximize their profit, not give customers a discount because the cost to manufacture went down. As this relates to gas, the retailer is selling you gas based on the price it will pay to replace the gas that you just bought. As demand for gas goes up, the price of gas goes up because people want more of it but there's still a fixed amount."
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6to6f0 | How can a cell phone receive a 4G, 3G, 2G, 1G, and no signal in a short time (10-15 minutes) without physically moving location or orientation? | Repost | explainlikeimfive | {
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"dlm8225"
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"text": [
"A huge Pokemon-Go raid appears near your location But seriously, there are a lot of factors that can play into signal reception. It could be the weather, a network issue, something about objects/obstacles between you and whatever tower your phone is trying to connect to, the number of other users nearby and their data usage, internal phone operations and power consumption, and network-specific issues occurring within the tower network backbone."
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6tpcie | We carry 4k cameras around in our pockets. Why are television/movie studio cameras still massive? | Repost | explainlikeimfive | {
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"> We carry 4k cameras around in our pockets. Why are television/movie studio cameras still massive? The 4k capable cameras in our pockets are terrible compared to the big studio cameras. The professional cameras have much better and larger sensors which have a larger dynamic range, less noise, and better color response. Other major factors are the ability to mount better lenses, electronics to support various things like higher frame rates, methods of storing footage and pulling it off the camera quickly, power for accessories like screens, remote viewing of shots and composition, connecting microphones such as boom mics, wireless lapel mics, image stabilization solutions such as powered gyroscopic Steadicam, mounting points for cranes, the list goes on. It is cool that we have very capable cameras in our pockets but your phone simply can't handle everything a movie set demands.",
"Apart from the basic quality issues people already touched on, zoom. In order to get a close shot on someone's face you'd need to be literally like 6 inches away with a cameraphone. All zoom there is digital zoom which reduces the overall visual quality. Imagine shooting scenes with cameras all 6 inches from people's faces.",
"Resolution, especially on a phone, is more of a marketing gimmick than anything else. There are many more important things that go to recording high quality video. A camera lens works on a physical level. A bigger lens = more light can get in and it produces a better image with lots of qualities we associate with professional cinema like steep dropoff of depth of field. While phones find some ways to imitate these things like using software to blur backgrounds and dual cameras to generate an artificial depth of field, nothing beats the real thing, especially since the real thing gets more advanced every year just like phones. On top of that are the many manual controls. These things take up space because crew need to be able to shift stuff precisely and quickly. A knob you can turn with your hand is much more precise and quick than a touchscreen. Phones have basically no controls - pretty much everything is done automatically. This obviously will not work in cinema when people are using the tools of photography in order to force a viewers perspective and create an artistic whole. A director sees what he wants in his head and the DP makes it happen - software cannot be relied on, especially when that software is meant for teens taking selfies, not for filmmaking."
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6tq5hb | What is nuclear radiation, and how does it actually kill people? | Repost | explainlikeimfive | {
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"The kind of radiation people worry about from nuclear technology and the like is called _ionizing_ radiation. That means that it has the ability to mess with molecules by stripping off electrons and changing their chemistry. Biological systems are very intricate, complicated \"machines\" that require chemistry to work correctly. Imagine taking a .22 rifle and shooting it through a circuit board of a computer. Will the computer still work afterwards? Maybe — but probably not. The radiation here acts like the .22 bullet. In most cases if it messes with a cell, it'll just break the cell and that will kill it. Cells die all the time, and have means of \"self-destructing,\" so losing a few cells is no big deal by itself. Lose too many at once — like billions and billions — and you start to suffer health consequences. Only _really_ radioactive sources can do this to you, but absorb enough radiation in the short term and whole systems of your body will shut down, injuring or even killing you in the short term (e.g., a week or so at most). There is also a small but real chance that any one of those radioactive particles will modify the cell's DNA (in the same way as before — by messing with its chemistry), and a small but real chance that the modification in question will make the cell turn cancerous. So even if the radiation you absorb doesn't hurt or kill you, it can raise your chances of cancer — there is a probability of one of your cells having become cancerous. Your base lifetime fatal cancer risk in the USA is about 20%. A dose of 1 Sievert — a pretty heavy amount (5 Sieverts is usually fatal) — increases your fatal cancer risk by about 1% (which is to say, in a population of people exposed to 1 Sv, you'd expect to see 1% more cancers than if they hadn't been exposed). Radiation can pose a contamination problem from two angles. The first is that some radiation poses a chance of making other things radioactive. So neutron radiation, for example, can \"induce\" radioactivity in non-radioactive substances. Aluminum, for example, can get very radioactive if exposed to neutron radiation. I don't think your hypothetical chicken is likely to be a radiation threat just because it was irradiated, though, but this is an issue with massive sources of neutrons (like nuclear reactors, nuclear weapons, or particle accelerators). The other angle is through contamination by radioactive products. In this case it is not the radiation itself that is the contaminant, but the fact that there is \"radioactive dust\" that is a contaminant. So when a nuclear weapon explodes, it creates lots of tiny radioactive particles called fission products that then go up into the mushroom cloud. These can attach to dust or water molecules and then fall back to Earth. These fission products are versions of \"normal\" atoms, like iodine, that are somewhat broken. So regular iodine (Iodine-127) is good for you and so your body takes iodine that it finds (e.g., that you eat) and moves it into places in your body where it can do some good (like your thyroid gland). Great. But nuclear reactors and nuclear explosions create radioactive iodine (Iodine-131), which is chemically identical to the \"good\" iodine but will emit radiation. Your body can't tell which is which (because it uses chemistry to tell the difference), and so it takes the \"bad\" iodine (Iodine-131) and puts it in your thyroid gland as well. Once its there, it will decay away, releasing radiation, and exposing your thyroid gland to it, increasing your chance of thyroid cancer. So in your chicken example, if your chicken is contaminated by radioactive byproducts — e.g., that it ate or drank or breathed — and then you eat the chicken, now you've got those same byproducts in your body. Depending on the byproduct, it might just be excreted after some amount of time (your body can't do much with, say, uranium) but others might be either something your body like (like iodine) or chemically similar to things it likes (strontium is similar to calcium, and your body likes calcium) that your body will take these \"broken,\" unstable atoms and move them into places where they shouldn't be (like your thyroid gland, your bones, etc.). Animals are affected by radiation as well (as are plants!), though the damage can vary by species (insects, including but not limited to cockroaches, are famously more immune to radioactivity than mammals). For long-term cancer risks, some animals lack the lifespan to really suffer from cancer visibly (the cancers can take decades to develop, and if your species' lifespan is only 5-10 years, you probably won't see radiation-induced cancers), so it doesn't always pose the same threat to them as it does to humans (who live relatively long lives compared to most animals). At high-enough dosages of radiation, practically any living thing will suffer — with high-enough radiation you can even kill trees (it's been done experimentally)."
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6tr0kt | How come people have been around for hundreds of thousands of years, and then suddenly in the past 100 years we've gone from horse and buggy to spaceships and up close pictures of Pluto? | Repost | explainlikeimfive | {
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"Sanitation, vaccines, better nutrition, and safer city states to name a very few of an incomplete list of things that allowed us to look beyond the formidable tasks of daily survival. For most of our sorry history, we lived short miserable lives.",
"Those discoveries and developments are just products of the previous eras. Human population has been growing exponentially, and you need a certain amount of population to allow some people to be idle inventors, rather than farmers or other providers. At the end of the 18th century, more and more people were able to develop machines because they had time, sparking the industrial revolution. This snowballed, releasing more people from farming and allowing more inventions to be designed and implemented.",
"I think the boom can be attributed to the industrial revolution. The industrial revolution was not so much of an advance is technology as it was a different way of thinking. For hundreds of thousands of years before, the only way people could ever imagine something being made was by hand. Quality over quantity. That whole concept was turned upside down with the industrial revolution. Instead of things being made by hand, they were made by machine. Quantity over quality. That shift in thinking lead to our current situation."
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6tsd0z | Why does blood, semen and other bodily fluids glow under a black light? | Repost | explainlikeimfive | {
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"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [ELI5:Why are body fluids detectable with UV light? ]( URL_0 ) 1. [Eli5: how is it possible to see traces of blood or semen under special lighting even when the area looks completely clean. ]( URL_2 ) 1. [ELI5: Why is blood visible under UV light? ]( URL_4 ) 1. [ELI5: Why does sperm show up under a blacklight? ]( URL_1 ) 1. [ELI5: Why does semen show under blacklight? ]( URL_3 )",
"I don't think it really does that much. I had one to check for dog stains and it didn't really work. At least on tv they spray with a chemical and then the bodily fluid glows under black light."
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6ttsbw | Why laptops still use differrent chargers, and why they dont follow the example of the mobile phones? | Repost | explainlikeimfive | {
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"$$$$$$$$$$$ Same reason apple uses its own cords. You have to buy them from the company that makes the laptop."
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6ttvtc | Basics of Electricity, Volts, Amps etc.. | Repost | explainlikeimfive | {
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"When this question comes up, I like to show [this]( URL_0 ) cartoon. An easy way to think about electricty, is to think about it like the flow of water. Volts is water pressure, amps is gallons per minute, and ohms measures the resistance water must overcome to flow. Watts is a measurement of enegery, and it can be calculated by multiplying amps times volts. Going back to our water analogy, think of a pressure washer. If your pressure washer's pressure stayed the same, but put out more gallons per minute, it's easy to understand how your flow of water has more ability to do work. The same is true if your GPM was constant, but the pressure increased. Single phase vs 3 phase is slightly more in-depth. In the US homes are generally run off 120 volt AC power. AC stands for alternating current. Imagine your pressure washer started off with out any pressure, increased to 120 psi, fell back to 0 pressure, then sucked up water at 120 psi. It does this many many times a second. (Like a wave) While you are pressure washing your driveway, you think about how much more power your pressure washer would have if it didn't take time to go from full flow, to suction. Well what if you had 3 pressure washers, all a little out of sync from one another? While pressure washer A is at 120 psi, pressure washer B would be at 40 psi, and pressure C would be at -40 sucking up all that dirty water. [The power of the 3 pressure washers working together would be more than any single could produce by itself.]( . Hope that helps",
"Think of water flowing through a pipe. Volts is the water pressure Ohms is the resistance from the pipe (diameter, ect) Amps is the gallons per minute passed through the pipe.",
"All the water analogies are kinda useful as conceptual aids but they don't really explain much about elecricity at all. First thing that is important to understand is that electricity and magnetism are very closely related concepts. They are so related in fact that it is formally impossible to distinguish between them. Electric fields and magnetic fields are both manifestations of the same phenomenon. The difference between electricty and magnetism is one of reference frame. (we say that magnetic fields are lorentz transformed electric fields and vice versa) and we call the entire phenomenon electromagnetism. It is in fact impossible to separate them. looking at one withouth considering the other is only possible through simplification and careful constraints of our descriptive model. The theory of electromagnetism is quite old. Older than einstein's relativity theory but it's formalism was so well established that Maxwell's theory of electromagnetism survived Einstein's relativity and we still use it to this day. Behind all the nice formulas and ideas you learn in school are a series of differential equations and their solutions. Maxwell's equations are differential equations. Diferential equations are complicated beasts and it takes advanced mathematics to work with them. A differential equations looks just like a normal equations except some/all of it's terms consist of derivatives. Derivatives indicate the rate of change of variables in relation to other ones. Differential equations are therefore equations of change. They describe how certain quantities change in relation to each other (differential as in difference) This is all fair and nice but now imagine we want to describe electricty without being forced to spend several years learning advanced calculus. No problem. we can create a simpler model that approximates the real world close enough for our porpouses. As long as we are careful to stay within certain constraints, our model should be preety accurate. However, we might need to adapt or expand it if we want to deal with specific situations outside our model's scope. The simplest model we use when dealing with electricty 101 is called the electrostatic aproximation. We can do a lot with this model. We can use it to predict many real world behaviours of electricity and we can understand 90 percent of all common electric circuits with it, but only as long as we keep within our model constraints. For the electrostatic aproximation our constraints are no time-varying (changing with time) electric or magnetic fields. if there are electric currents or magnetic fields they should be either constant or only change very, very slowly Now that our model and constraints are established lets look at the most common concepts of the electrostatic world: The basic building block of Electricity is the electric field. Fields are basically regions of space that have certain properties. The electric field describes the magnitude and direction of the force an electrically charged particle experiences on itself when placed in a certain region of space. You can have both negative and positive electric charges. similar charges repel and opposite charges attract each other. This repelling/attracting force is called the coloumb force. The unit of electric charge is the coloumb. More charge results in more force between charged objects. larger distances results in less force between charged objects. In a sense this is all there is to know about elecricity. electrically charged objects will experience forces in an electric field. The direction and magnitude of the force is related to the charge of the object and the specific electric field it finds itself in. Now lets set up a simple thought experiment: We set up on either end of a room two separate boxes. We fill one with a lot of negatively charged spheres and the other one with the same number of positively charged spheres. What will happen ? well we know from coloumbs formula that the spheres inside of each box will repel each other. so inside each box the spheres will try to separate as much as possible. Most of them will end up evenly spread scross the box's inner sufrace. This is now how we can imagine electric charges to be distributed across an electrically conductive charged body. Next we bring the boxes next to each other. We know the spheres in each box now attract the ones in the other box. We will find inside the first box that most spheres have accumulated in the side of the inner wall facing the other box due to being atracted by the spheres inside the other box. The inner wall where the spheres accumulated is now more charged than the opposite wall. This separation of charge in the precense of other charged bodies is called induction. Now an important question. If the spheres are atracted.Why aren't the spheres jumping from box to box to meet each other ? well because the box has walls. Remember, The electric attraction is still there as we saw from our induction experiment. it is the wall itself that is stopping the spheres from meeting each other. If we wanted the speheres to meet each other we would have to increase the magnitude of this attractive force until it was strong enough to break the wall. We could call the wall a resistor. Since it resists the movement of charges in the precense of electric fields that arent strong enough to overcome it's resistance. Electric resistors work preety much like that. The unit of resistance is the ohm and it defines how much spheres will manage to break a hole in the wall per second given a certain magnitude of the electric field. To overcome this resistance we could make the atracting force stronger. for example by making each sphere have 10 times as much charge. Eventually the walls wont be able to hold and spheres will start flowing between boxes. This is the same as increasing the voltage in a real circuit. The unit of voltage is the volt and it defines the strenght of a electric fields on electric charges. A much easier way tho is just to build a tube connecting both boxes. We can call this tube the conductor, because it will conduct our charged spheres to where they want to go. A larger tube will carry more sphere's per second and so will have a lower resistance. Adding obstacles inside the tube will instead reduce the amount of spheres that make it through and will thus cause the recistance of our tube to increase. Not all tubes are the same and therefore not all conductors are the same. Some are better and some are worse, the unit of conductance is the siemens. Now that we have a nice conducting tube connecting both our charged boxes. spheres will start to freely flow between them. Positive spheres will flow one way and negative spheres will flow the other. However, since we are smart, our unit of current changes sign depending on the respective charges. So positive spheres moving one way count the same as negative spheres moving the other way. The spheres per second that flow through our tube ( when considering their charge) is our current. The unit of current is the ampere. So, now we have defined our most important electrostatic units. Electric charges are measured in coloumbs. Obstacles for our charges are called resistors and are measured in ohms. Paths for our charges are called conductors and are measured in siemens (1/ohm). The strenght of the electric field in a given area of space is measured in volts. Moving charges are called currents. How many charges pass through an area of space in a second is our current and it is measured in amperes. Now we have given ourself a nice simple and consistent model to deal with electrostatic situations. Yet, we havent considered what we can do with this knowlede. For this we will have to expand our model with ideas of energy and power. which are not really exclusive to electricity and therefore outside the scope of this explanation. For this we will have to introduce the idea of watts/volt-amperes into our model. Then we will find that we cant really separate electricty from magnetism as cleanly as we hoped. Specially as soon as we start looking at dynamic systems ( all real life systems are dynamic). we will need to introduce the magnetic field and ideas like magnetic voltages. Lastly we will find out that charges and conductors are not really needed for an electric field to exist and that Electro/magnetic fields are not things you can separate into one or the other. We will free ourselves from the constraints of our conductors and consider electro-magnetic fields travelling freely through empty space. To finally arrive at the concept of electromagnetic waves. At this point we would have covered about two/three semesters of higher studies in electromagnetics but we would still have a lot to learn There is sadly still a lot more to explain but this post is already too long. If you have any specific questions feel free to ask tho."
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6tu63r | How did humans come to value Gold so highly? Just because it's pretty? | Repost | explainlikeimfive | {
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"Gold has a number of characteristics that make it useful as money: * Gold is fungible. So any ounce of gold is very replaceable with any other ounce of gold. Take diamonds for example as another rare shiny mineral with unique properties, some have inclusions, some have less color, some are naturally larger crystals, etc and all those impact the rarity of the diamonds (large, colorless, diamonds with no inclusions are really rare, small brown diamonds with lots of inclusions are quite common). * Gold is malleable. That means it can be hammered into shapes without heating it, and can be divided with very basic tools. That's a very useful characteristic under the barter system, as it allows easy trade in something worth only a little. Further, gold isn't often valued as a large nugget, so reshaping it doesn't reduce its value. * Gold is a very stable element. It's tough to oxidize, corrode, dissolve, etc. It takes a specific combination of two acids to dissolve, and it can sit in seawater for centuries without corrosion. That means when an ancient rich man stored gold somewhere, it was likely to remain in good condition until removed. * Gold is very dense. There are only 3 elements more dense than gold (and they're quite rare) and the one element that's similar in density to gold wasn't isolated until pretty recently. That density gives it a strong protection against counterfeiting, and an easy means to check, all you need is a scale, a string some water, and a means to hold the water. * Finally, it's rare enough that it has quite high value (so a man can easily carry enough gold to make even large purchases). Those characteristics all led many early humans to make gold their money, once they'd encountered enough of it.",
"In addition to all the other things listed here, gold is also easily measurable. As an element, gold has a fixed weight. You can weigh something gold and determine how much gold there is in it, compared to what other materials there are in it. That makes it easy to standardize. That's what got Archimedes so excited when he discovered displacement; he was asked to determine if a crown was made of gold, or if it was made of something else, and to do it without destroying it. When he observed the effect he had on his bath water, he knew he could measure the displacement and replicate the effect with other objects and compare them to each other. Which would give him the information he needed to measure the crown without destroying it.",
"**Gold has a steady amount of expended work required to mine it. ** Many of the other posts point out the malleability, and rapid identifiability of real gold. But the fact that gold represents a fairly stable unit of labor for production is what makes it valuable as a token of a unit of work. It may sound strange but this is what makes money valuable: the amount of effort wasted to produce it could have been used to do some other task. In a given society, even as tools of mining improve, those same labor saving tools and technology can generally be put to use in other endeavors - making spending them mining fixed in value to the opportunity cost of not using them producing food or other goods. This is also what is behind the \"wasted\" computer resources required for \"mining\" bitcoins. It establishes an opportunity cost of producing the currency. **Currency is extremely abstract. **Even more than we tend to appreciate today. One extreme example that points this out are **Rai stones.** On the island of Yapp and nearby, inhabitants used to use giant 1-3 meter tall rings of stone mined from distant islands and precariously hauled by canoe as currency for large transactions like marriages or houses. The actual currency being so heavy, the stones often didn't even have to move to change ownership. People just kept track of who owned what. A house would change ownership and in exchange so would a stone. In fact, there is at least one example of a stone being quarried and cut but lost in the sea when the canoe capsized. Everyone agreed that although they couldn't see it, the stone must still be there at the bottom and that it could still be traded just the same as any other.",
"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [ELI5: Why is gold so valuable? ]( URL_0 ) 1. [ELI5: Why is gold valuable? Also, why was gold important to ancient civilizations? ]( URL_2 ) 1. [ELI5: Why is gold so valuable? And why is it more valuable than other metals, like silver? ]( URL_1 ) 1. [ELI5: Why is gold worth so much money in modern times? ]( URL_4 ) 1. [ELI5:Why is gold used as a store of value? ]( URL_6 ) 1. [ELI5: Why is gold so valuable to the world? ]( URL_7 ) 1. [ELI5:The infatuation that humans seem to have with gold? ]( URL_3 ) 1. [ELI5: Why gold is considered valuable? Why were currencies compared to the amount of gold? ]( URL_5 )",
"It has aesthetic value, but it is also malleable and ductile, letting us do a lot with it. It's very resistant to corrosion, so it lasts a very long time. And less useful in the past, more of a modern note, it carries electricity very well. Add all that to the fact it's rare, and you have a nicely valuable substance."
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6tucxs | Heat index. How can it BE 100°f and FEEL like 110°f? | Repost | explainlikeimfive | {
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"Heat index is essentially a measure of the effect of humidity on a person's perception of temperature. Humidity makes us feel hotter in the summer because the body cools down primarily through evaporative cooling. Basically, the water in/on your skin evaporates in the hot weather and transfers heat from your body to the surrounding environment. This effect is lessened when humidity is high because the air is already saturated, so the water on your body will not evaporate as easily, thus making you feel warmer."
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6tudqq | Why does grease make paper transparent-ish? | It often happens when I'm eating something greasy and use napkins or something made of paper, that the paper loses its colour and becomes blurry. Why? | Repost | explainlikeimfive | {
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"dlnkhf4"
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"text": [
"Light changes direction when entering a different material. Paper makes light go in lots of directions. Adding oil which changes the direction at the same angle as paper reduces the scattering caused by the air/paper interface allowing more light to pass in the same direction."
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6tugtn | What causes people to talk with a lisp? | Repost | explainlikeimfive | {
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"> The motht frequently dithcuthed of thethe problemth ith tongue thrutht in which the tongue protrudeth beyond the front teeth. Thith protruthion affectth thpeech ath well ath thwallowing and can lead to lithping. Ankyloglothia or tongue-tie can altho be responsible for lithpth in children - Google"
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6txdeo | The difference between increasing your heartbeat with caffeine and increasing it with exercise. | Why is it unhealthy to increase your heartbeat from drinking too much caffeine, but increasing it the same amount during exercise is good for your heart? | Repost | explainlikeimfive | {
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"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [ELI5: Why is cardio exercise good for your body, while using stimulant drugs is bad for it? They both increase your heart rate and make your body work so isn't taking the stimulants just a form of exercise for your heart/body? ]( URL_4 ) 1. [ELI5:Why is it good for you to raise your heart rate through aerobic exercise but not through caffeine, stress, anxiety, etc? ]( URL_1 ) 1. [ELI5: Why is raising your heart rate through exercise good for you whereas doing it via caffeine or cocaine is really bad for it? ]( URL_0 ) 1. [ELI5: Why is exercise that increases my heart rate considered good, but medication and narcotics that increase my heart rate are considered bad? ]( URL_2 ) 1. [ELI5: Why would exercise like cardio stress my heart in a “good” way when drugs like cocaine stress it in a damaging way? ]( URL_3 )"
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"https://www.reddit.com/r/explainlikeimfive/comments/2ueh9z/eli5_why_is_exercise_that_increases_my_heart_rate/",
"https://www.reddit.com/r/explainlikeimfive/comments/1pa8tq/eli5_why_would_exercise_like_cardio_stress_my/",
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6u0b05 | Why is water essential for life? | Repost | explainlikeimfive | {
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"There might be a form of life that uses something else. But we can only speculate. Water is a unique chemical with many special qualities. It's solid form floats in its liquid form. Its polar nature makes it an excellent solvent. It readily separates into a proton and a hydroxyl group allowing many chemical reactions. Our chemical engineers build distillation equipment that works without water. They build cracking towers which process petroleum. Many chemical reactions must occur without water present. But we are mostly water. It is how life on Earth works."
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6u15t5 | Why can sound get through walls when light can't? | Repost | explainlikeimfive | {
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"Sounds is a pressure wave. It works by the periodic compression and expansion of molecules in the medium it travels in. Air works fine, water works better, solid materials work even better - generally, the denser a material, the faster sound will be able to travel. So sound can travel through walls because the material the wall is made of compresses and expands to allow the sound wave passage. Light is an electromagnetic wave. For an electromagnetic wave to be able to pass through a material, there needs to not be a mechanism which blocks it. Examples of mechanisms which can absorb electromagnetic radiation are diffraction, where the wave gets spread out by a gap which it passes through (comparable to its wavelength); molecular absorption, where the light is absorbed by the bonds of molecules, causing them to vibrate, rotate, stretch, etc.; and atomic absorption, where a photon of light kicks an electron in an atom up to a higher energy level by being absorbed by that electron. The materials our walls are made of have electronic structures in their atoms and molecules which mean that light is either reflected or absorbed by their surfaces. Glass, meanwhile, has molecules where it's electrons are bound up in bonds that don't have an energy or wavelength comparable to visible light so they won't respond to it. A good rule of thumb for figuring out if something will interact with a particular wavelength of light or not is to see whether their energy/length scales are the same as the light. For example, x-rays diffract between the atoms in crystals because the spacing is a similar wavelength to that of x-rays; many molecules absorb infrared radiation because their bonds lengths are similar to the wavelengths of infrared, and some radio waves will only travel a few miles because their wavelengths mean they diffract around hills and other features if the landscape."
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6u43zc | Why is eating raw food like steak tartare or sushi okay when we're warned to cook other foods to a minimal temperature so that it's safe? | Repost | explainlikeimfive | {
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"Some foods are more prone to parasites than others, and (importantly) some parasites are easier to kill than others. Chicken is a good example - salmonella bacteria can be somewhat commonly found in chicken and can infect the meat all the way through. So we take care to cook the chicken well all the way through in order to kill it. Same deal with pork and trichonosis - that can infect the entire muscle, and not just the outside. In contrast, most of the bacteria that commonly settle on steak and lamb aren't usually able to get down inside of the meat (and once they do, the meat goes rotten and it's easier to tell that it's not safe to eat). So it's safer to just sear the outside (killing the outside bacteria) and eat the rest of the meat rare. Fish have parasites that can infest all the way through, but all fish in most countries is required to be quickly frozen as soon as they're caught, which kills the parasites as well. As long as it's eaten fresh so that no new parasites can infest it, it's pretty safe to eat raw. As long as the transportation and kitchen are clean, there's not much to worry about.",
"Many meats are (relatively) safe to eat uncooked if handled properly. There is still a risk of contamination and getting sick. Things like chicken and shellfish are rife with salmonella and the odds of getting a rather unpleasant bacterial infection are high.",
"Eating raw food has a risk to it though the risk is small. You can take a bite of raw chicken and you will probably not get sick but to reduce the risk to as near zero as possible, it is advisable to cook food to the recommended internal temperature. Proper slaughtering and processing also help reduce the risk"
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6u4b04 | How do some restaurants, particularly diners and Mexican restaurants, afford such large portions? | Repost | explainlikeimfive | {
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"Because they make food with cheap ingredients. In general the price of your meal is 4-6 times the cost of the ingredients to make it. Mexican food uses cheap cuts of meat (often scrap meats), rice, and beans. The only expensive components are things like avocado or special cheeses and even those are still not extremely expensive.",
"Mexican food is largely composed of very inexpensive ingredients, like rice and beans, with inexpensive Meats like chicken cooked in huge batches. Most parts of the meal can be prepared in advance. All these things cut down on price significantly."
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6u4u7g | How do cranes get up to higher floors when tall buildings? And then how do they get down? | I notice that when skyscrapers are being built they move the cranes up as they go, how do they get up there? Once they are done building how do they get back down? | Repost | explainlikeimfive | {
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"URL_0 Simply put, the crane builds itself as it needs to, and tears itself apart as it needs to. It is immensely fascinating to watch (hence why the link is in the beginning). To give it more like an ELI5. The crane is modular, so you can add pieces to the tower as you need, or remove pieces from the tower. As the crane can move these modular pieces onto itself it uses a jack system to raise itself slightly so that the new piece can fit in. Then someone bolts down the new piece and the jack system is raised and then attached to the new piece so it can do it over again. The reverse is used to lower the crane.",
"My dad ran tower cranes for 30 years. They call it jacking the crane. There is a piece called the jacking collar that hooks into two sections of the tower and then literally jacks the top section up so that for a little bit of time there is actually a hole into which the crane lifts another section from the ground and the jacking crew inserts the new piece and bolts it in place. They raise the collar up and add more the same way. They normally do around 4-5 sections at a time. It is pretty time consuming and dangerous. He knew guys that got crushed when the collar slipped. There are specific crews that just travel around and do this. They usually work for the crane rental company as almost all cranes are rented for the jobs. They cost several million dollars.",
"They \"build\" them. The one I saw was able to lift it's main body section (or whatever) high enough for the workers to add sections to increase its height one section at a time. The legs extend out, lift the crane, workers install more scaffolding like sections, it's able to incorporate this into the entire structure...rinse and repeat. Opposite chain of events to take it back down when done.",
"The tower cranes you see for such projects are made out of modular sections. You can add or remove sections as you want. The top part of the crane can move up one section so you can slide a new section under the top, you use the crane to lift the new section into place. Similarly you can anchor the crane to the building at a higher floor and remove the sections under the new anchors. When they are done most of the crane can be lifted down off the building by the crane itself. The last few sections are much easier to get down. For example by using winches or a helicopter."
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6u52uf | Why are we putting our hands in front of our mouth when in shock? | Repost | explainlikeimfive | {
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"dlpzmad"
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"text": [
"It is a way of concealing our emotions from others, to avoid showing that we are afraid, shocked or disgusted."
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6u58dd | Private-Public Key Cryptography | Repost | explainlikeimfive | {
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"dlq0sse"
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"text": [
"This is a very common question, and [this Search]( URL_0 ) generates lots of detailed responses. Please Search. It's an encryption system which uses two-part keys for each user. One part is published, for sending messages to the user and the second part is kept secret, for messages from the user. Each message is encrypted using the sender's private part and the receiver's public part. This assures the sender that only the receiver can read it and the receiver that only the sender could have sent it."
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6u688p | How do high areas of heat ripple our vision? | Repost | explainlikeimfive | {
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"dlq9d9l"
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"text": [
"Hot air is less dense than cold air, and light travels through them at slightly different speeds. At the boundaries between hot and cold air, the difference causes light to refract (aka bend) as it passes from one to the other. As the hot air rises and circulates with cold air, the boundaries between hot and cold constantly change as well as does the direction of light passing through. This creates the moving, ripple effect."
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6u6m0h | Why does the letter 'a' look the way it does in type but often looks differently when handwritten? | Repost | explainlikeimfive | {
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"dlqoqmc"
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"text": [
"Noice that the written version is the same as the types version minus the hook in top. Well, the written version is just an abbreviated version, because it's easier and faster to write, but they still use the full version on some fonts since it's not any easier or harder for a computer."
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6ub388 | How do all kinds of dogs look so different but are still essentially...dogs ? | Repost | explainlikeimfive | {
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"text": [
"Selective breeding over literally thousands of years, to select for different abilities; hearing, smell, ability to run, ability to dig, strength, power, you name it. Humans naturally diverge based on their geographical location. Obviously nowadays with travel and the world being a much smaller place than it was, and general technology, these things have become less relevant, but this is the reason that more northern (or below the equator, sourthen) people tend to be lighter skinned, and people from hotter more equatorial regions tend to be darker. Dark skin is an advantage in bright powerful sunlight because it protects against sun damage, a natural sunblock. Why isn't everyone dark skinned then? Because if you're in areas where sunlight is weaker (more temperate to cooler regions), dark skin prevents you absorbing enough vitamin D. Which is why people historically from those sort of areas are paler skinned, and the colour tends to vary with the general temperature of the area they're from. Those natural varations have just been exploited with dogs, over a long *long* time selectively breeding for certain traits to accentuate them, and diminish others. It would in theory be possible to do with humans too, breed for height and...well whatever you want, given enough time, but that is obviously an *extremely* morally dubious area of thought. Known, if you're curious, as [\"Eugenics\"]( URL_0 )."
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6ubsie | How do torrents work? | Repost | explainlikeimfive | {
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"text": [
"I would recommend watching [this]( URL_0 ) video, explaining what exactly torrents are and how they work In short, \"seeders\" are people that upload *things* to internet. A \"peer\" is anyone connected and transferring data A \"tracker\" is a server that keeps track of which seeds and peers are in the \"swarm\" (all peers (including seeds) sharing a torrent)",
"Basically the way that torrent works is that it has files chopped up into tiny pieces and each is individually and assembled together as it downloads. The magnet link or .Torrent file contains a list of trackers among other information, trackers being servers that negotiate connections between people downloading through torrent. A seeder is a person who has the complete file and uploads it to other users, peers/leechers are people who are still downloading the pieces, but they also upload the parts they have to other users. Anyways, point is that it is a distributed system of downloading files, without having a single server feed you the entire file, you just grab chunks from various other users, both seeders and leechers."
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6udtzh | How is lobbying not considered bribery? | Repost | explainlikeimfive | {
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"text": [
"Frequently the things of value provided to the government official are not money and nowadays even though some non-monetary bribes are also outlawed there are many ways to disguise the bribe. One fun way is to arrange to have a book written for the politician under his/her name, then buy back thousands of copies with the royalties going to the politician legally (though there are efforts to stop this one too). There will always be ways. A fancy way I particularly like is to arrange fundraisers and otherwise package huge campaign contributions to the government official. This can be done even if he is not running for anything, or is running unopposed. There have even been cases where campaign contributions were made to bribe politicians (in non-elected jobs) who weren't even *planning* to run for anything. Then the candidate can raid the campaign contributions for personal expenses and even, in many cases, totally confiscate the campaign contributions after the campaign is over (even if there never was a campaign). I worked for a long time in an entity where lobbying was in the same division (I was not a lobbyists but in a related and honest function). There was no pretense, internally, that what they are doing was not bribery; it's a joke."
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6uhfip | after watching my 3 year old play in her imaginary world, what changes in our brains as we move into adulthood that we lose this skill? | Repost | explainlikeimfive | {
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"Follow up question - what do you mean by *lose* this skill? I'm 22, do extensive worldbuilding in my head and have an imagination that can keep track or hundreds of personalities in one world I create in my head. When I commute or go to bed I go through the same thing your daughter does",
"Hey, funnily enough I [answered this question for another person with a video a while back]( URL_0 ) If you dont want to watch the video I'll run over the points here too: - We are more in touch with reality as we grow older. The economy, and our limited time on this planet distract us. We need to make sure we can provide for our family and friends, we study and work to make sure we can live a comfortable life. - Social norms also take away from us, we understand we have a role in the world and as adults we believe we shouldn't be seen being \"childish\" and having a very active imagination can be seen as this. I personally dont agree with how people see this as childish at all, I think it's a great character to have. It's different depending on culture though, as we are brought up in a certain way to see adults as responsible, serious hard working individuals. - We care about what other people think, children do not. There have been studies to show that they dont care, they dont see the world the same as us. Kids are a bundle of joy (most of the time!), as we grow older we are much more worried about how people see us. This may be down to the fact that we are hardwired to find a partner and have children. If we dont act in an attractive way, then we may not find a mate. It's pretty blunt to say, but at the end of the day we are animals and our top priorities are survival and breeding. - We are much more busy as adults, as I stated before we are constantly working and our lives get swallowed by work. The majority of people don't live in the now. They live constantly thinking of the future, not paying attention to the here and now. Children are different, they live for the now. They try and enjoy themselves as much as possible. Playing and imagining cool scenarios are examples of this. For example, if a child was sat in a car they'd look out the window and see a blank canvas. They'd imagine a character running along side the car doing all sorts of cool stunts (that's what I used to do). However, an adult may not think like this, they'd think about people, work, debt, schedules etc etc. Hope that helped, and I hope you enjoyed the joke at the end of the video. I usually answer peoples questions through this subreddit in the form of a video and I've been doing it for a year now. My drawing has got slightly better, along with my animation skills. This video is pretty old, but it targeted your question so I thought I'd try and help you out! Have a great day.",
"You simply stopped doing it. Not everyone does and those that continue it are still able to do this. They tend to use said skill to write books, write video games, make movies, make tv shows. And in the non-professional realm they write fanfic, picture books as they read them, play table top games, etc.",
"I would propose that you simply get smarter. The same idea might pop into your head \"man wouldn't it be cool if a dragon had machine guns mounted on it?\" But then the logical part of your brain would step up telling you how angry a dragon would be, how relatively useless machine guns would be attached to it, etc. If you asked a child \"why does the dragon let you ride it\" the child might say \"We are friends\" but you would ask yourself \"well why are we friends, how could we possibly have met and developed a friendship.\" If you want to go around riding on a dragon doing crazy adventures you basically have to come up with the entire Game of Thrones world in order to satisfy the questions you would have. That kind of thing takes a tremendous mental effort and commitment of time. You have to justify to yourself spending that time on it. However, when those answers are given to you, you will absolutely lose yourself in fantasy for hours at a time: look at video games, movies, or books. Those things really are just guided imaginings.",
"In fact we still have that skill, we just don't use it anymore because as we grow older, we adapt to the reality and accept it as it is. As adults we have responsibilities and pressures such as making a living. Most of the adults find daydreaming as silly and distracting. But there are people who still do it as adults, they are writers, actors, movie directors, etc. There are a minority of other adults who do it compulsively, and that condition is called [Maladaptive daydreaming]( URL_1 ). Most people are unaware of this, including mental health professionals. [BBC World News Aug.9.17 story on Maladaptive Daydreaming]( URL_0 )",
"We do imagine stuff though don't we? Like I'm always imagining conversations, what I'll do when I get home, what is going on in the head of white nationalists, how many upvotes I will get for this post etc etc. It's an important part of how we plan for the future and understand one another. What I'm saying is our imagination doesn't disappear it just gets used differently."
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6uiq52 | how did ravens/ pigeons know where to go when released with a message!? | Repost | explainlikeimfive | {
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"text": [
"they only know how to fly home. thus they're called homing pigeons. it's one directional communications. raise a homing pigeon from birth at a location and it always goes back there."
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6ujok0 | Why do babies are born so unprepared for life? | Repost | explainlikeimfive | {
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"text": [
"> Wouldn't being a bit prepared for danger a better evolutive advantage? It would, but evolution does not work that way. There is no plan, no one guides it. Evolution just happens and if the result is an improvement it lasts and if it's not it dies off. So there are lots of things that would be beneficial to have if Humans evolved them, but it just hasn't gone that way. Humans have a few advantages over other animals but when it comes to our babies, 2 are in conflict. Ancient humans hunted for food, but we're not as fast as many other animals. We have an advantage over them however, we have stamina. Our ability to walk on 2 legs, plus the way we dissipate heat means ancient humans were able to \"run down\" most animals then just walk up and kill it when it was so exhausted that it could not go on. This \"walking on 2 legs\" this is important. It's much more efficient than 4 legs, but it's not as fast. Su we are better able to use our resources and out last out pray in part because we walk upright on 2 legs. That's an advantage that evolution HAS given us. The next advantage is our brains. Human brains, as compared to the overall size of our bodies are very large in comparison to other animals. Big brains, make us smarter. You could say that the human brain is the single biggest evolutionary advantage that there ever was. Big brains need big heads, because of the way brains grow, a baby is like half head. So, big headed babies and the requirement to walk upright. These 2 factors come into conflict at the pelvis during childbirth. Human women need to give birth to a \"half cooked\" offspring because if they wanted longer the baby's head would be too large to pass through the pelvis. If the pelvis changed it would affect our ability to walk upright. So human babies are born unprepared because that's what needs to happen in order to maintain our 2 other advantages, walking upright and big brains."
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6ujwt8 | Why is water so destructive to electronic devices? | My wife dropped her phone in a bucket of water for probably half a second and now it's completely ruined. What is it about water that so thoroughly destroys electronic devices? | Repost | explainlikeimfive | {
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"text": [
"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [Why does water ruin electronics? ]( URL_3 ) 1. [ELI5:What makes electronics break if you soak them in water, even though they are turned off? ]( URL_1 ) 1. [ELI5: why exactly does water hurt electronics? ]( URL_0 ) 1. [ELI5: Why does water ruin electronics? ]( URL_2 ) 1. [ELI5: how exactly does water ruin electronics, assuming that they are turned off after and dried throughly, what damage to hardware is done that is irreparable? ]( URL_4 )",
"There are two ways that water can destroy electronics. And both are worse in salt or soapy water. First off the water might conduct electricity better then the air so you might create additional electrical paths. This can overload components that can get more current then they are designed for and destroy them forever. The second and more common as voltages in devices is getting lower and lower is by reacting with the conducting coating on the circuit board and the connectors. You may have observed crystals forming on the terminals of old batteries and you may have cleaned them off to get it to work again. The same thing can happen to circuit boards and may be accelerated by water. But unlike battery terminals there may not be enough material underneath for you to be able to fix it. So if you drop something in water then try as best as you can to turn it off and disconnect the battery. If the water is salty or soapy then soaking it in clean water will help. Preferably distilled water. Then let it dry off in a dry room tempered place. You may have seen suggestions to use rice which will create a dry environment but take care that the rice will not actually be able to enter any gaps or contacts on your device. However a paper cloth may work just as well to create a dry environment."
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"https://www.reddit.com/r/explainlikeimfive/comments/y7vsg/eli5_why_does_water_ruin_electronics/",
"https://www.reddit.com/r/explainlikeimfive/comments/1p10lb/why_does_water_ruin_electronics/",
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6ulvkz | Why is it considered "wasting water" when I leave the water running or take a long shower if the water goes down the drain and is recycled at a water treatment plant? | Repost | explainlikeimfive | {
"a_id": [
"dltnsca"
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"text": [
"Water treatment isn't free. It costs money to build those plants & energy to operate them. If you're in a place that's got clean water shortages, you can still deplete your clean freshwater supplies faster than nature completes the water cycle to bring it back to you."
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6umsid | Why do some people get moody when they are hungry? | Repost | explainlikeimfive | {
"a_id": [
"dltvc12",
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"text": [
"Your brain needs enough food to work right. If you don't eat enough, your brain goes weird, which can make people moody. For the 12y/o version: brain function is tied vey closely to blood sugar levels. Believe it or not, there's truth to those snickers commercials.",
"When you're hungry, your brain and body aren't getting what it needs. It's similar to sleep deprivation in a way. When someone's sleepy, everything becomes harder for the brain to do, similar to with low blood sugar. It's also believed to be related to serotonin. > [While many factors contribute to this \"Hangryness\", it's believed that a large part of this aggression is caused by a droop in serotonin levels. Serotonin is what is called a neurotransmitter, a specific substance that carries a signal from one nerve cell to another. In this way, the amount of a specific neurotransmitter creates different effects on our body. Serotonin is unique due to the fact that its effects generally are inhibitory. In other words, serotonin reduces sexual behavior, suppresses pain perception, and stabilize moods. Researchers found that making individuals hungry leads to diminished levels of serotonin in the brain, which in turn, made certain parts of the brain weaker than normal (ie the parts that make us behave like humans rather than animals.)]( URL_0 )"
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6umv1n | Explain to me the fourth dimension | Repost | explainlikeimfive | {
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"text": [
"You might enjoy these previous posts on the topic: URL_0 URL_1"
],
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"https://www.reddit.com/r/explainlikeimfive/search?q=4th+dimension&restrict_sr=on",
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6uo8ax | Why do we make faces when we are doing something that requires more dexterity (i.e fine motor function) than usual? | This refers to things that include threading a needle, working with miniature things etc. | Repost | explainlikeimfive | {
"a_id": [
"dluca49",
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"It's basically you're involuntarily communicating through your gestures that you are concentrating and don't want to be disturbed. > A prevailing theory regarding the evolution of language implicates a gestural stage prior to the emergence of speech. In support of a transition of human language from a gestural to a vocal system, articulation of the hands and the tongue are underpinned by overlapping left hemisphere dominant neural regions. Behavioral studies demonstrate that human adults perform sympathetic mouth actions in imitative synchrony with manual actions. URL_0",
"This has been asked before, [kind of specifically about sticking out your tongue.]( URL_0 ) So...you're beta-testing the Discord video server, eh? ;)",
"Daniel Kahneman, a Nobel prize winning psychologist and economist, discovered the brain has two \"modes\", which he calls system 1 and system 2. System 1 is fast, instinctive and emotional; System 2 is slower, more deliberative, more logical, and requires concentration to use. We have both systems because each is fit for a different purpose. When the lion jumps out of the bush, you don't want to sit down and puzzle out a 13-point action plan. ~~These systems can be manually activated~~ You can help activate these systems by smiling and frowning. Smiling activates system 1, and this is thought to be evolutionary selection to help us get along socially -- quick banter, jokes, being in the moment, and paying attention to multiple things. Frowning activates system 2, and this is thought to be evolutionary selection for rumination -- when something is wrong in your life you need to stop and figure out what needs to change. Actually it would be more accurate to say that (like many things in physiology) they're activated in a feedback loop. Using system 1 makes you smile which reinforces system 1 which makes you smile which reinforces system 1, and so on. Similarly, using system 2 makes you frown which reinforces system 2. We stay in system 1 most of the time because it requires very little mental energy compared to system 2, which becomes exhausted quickly. Our body is always trying to put us back into system 1; or more accurately, system 1 tends to automatically answer questions before system 2 ever gets a chance, and it takes deliberate effort to ignore your first instinct in favor of puzzling something out. **tl;dr We frown while concentrating because it helps us maintain our concentration. More specifically, it's a biological feedback mechanism for activating system 2.** Kahneman wrote about the two systems in his best-selling book *Thinking, Fast and Slow*, wherein he also goes into detail on the cognitive biases each system is susceptible to. It's a really good book that can help us catch ourselves in the act, and I'd highly recommend it. You can read a brief summary [here]( URL_1 ), or a more in-depth one on [Wikipedia]( URL_2 ). EDIT: /u/lansaman also posted [a great video]( URL_3 ) on the subject below. EDIT2: NYT also did a [great summary of the work]( URL_0 ), and even gets into some of system 1's cognitive biases, as well as other conclusions from the book on the nature of happiness.",
"It's called overflow. Engagement in difficult tasks often causes involuntary changes in not just face muscles but other positional muscles too. Your efforts \"overflow\" into other areas of the body, since your efforts cannot make your hands be more hands... I hope that makes sense.",
"A lot of people are talking about faces relaxing, or becoming stonefaced with concentration. What about with something like playing guitar? My whole face has a life of it's own when I hit those full step bends, and it's definitely not relaxed... What's up with that?",
"Animating a face requires many muscles to work in tandem - complex stuff. I see it more as the LACK of making a face. Your mind is too focused on the task to even partially care if it's smiling or where your eyebrows are, slumping into a neutral energy-preserving state. But as a perpetual disinterested scowler, I'm hardly a professional in this field.",
"There is a term in psychology for this (I forget for know but I'll search for it) but it was observed in young children first. A neuroscientist noticed that when group of children were learning to use scissors for the first time. A lot of them would make the motions scissors do, but with their mouths. It eventually lead neuron recruitment Essentially your brain is recruiting as many relating neurons of that related skill to complete the task successfully I'll look for the term",
"Were social creatures. If were making a face its to convey a message. Evolution has led us to the point where these non verbal communications linger despite them not being directly advantageous to survival. In this instance making a face may suggest to onlookers \"this is a difficult task, please act in a way that aids me in performing\" or \"I'm enjoying this, please fuck off\"",
"Based on everything that I'm reading here, the correct answer is \"everyone knows but everyone disagrees so really, no one knows at all\". Just like virtually anything to do with diet or nutrition.",
"Your brain has a certain amount of resources it can use at once. It doesn't want to waste them controlling unconscious movements when something more important is being done.",
"Because we're completely unaware of our bodies. There's a site... lemme find it.. URL_0 that addresses this kind of stuff. I learned about it in acting classes, we did some workshops that addressed unconscious physical behaviors.",
"Follow up question, why do we grunt/yell when physically exerting ourselves like by doing a heavy lift at the gym?",
"As an expert in involuntary facial movements, I believe it is due to the fact that at least a small amount of our focus goes into not making stupid faces and keeping our tongues in our mouths. If we are forced to use all of our concentration we lose the bit necessary to not look like a goob."
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6uoed5 | why would you put +120fps on a game if your monitor is limited to 60Hz ? | Repost | explainlikeimfive | {
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"Basically, more fps equals less input lag, which is not important in every game, but makes a difference in some competitive games like CS:GO. Nicely explained [here]( URL_0 )."
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6uotmu | If bad taste is our body's auto-defence against bad/unhealthy food (eg. poisonous/rotten), why does junk food taste so good? | Repost | explainlikeimfive | {
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"Junk food is not unhealthy. In fact, it has *tons* of stuff our body needs to stay alive. Especially calories. Back when humans were hunter-gatherers, stumbling onto a small amount of high calorie food was a reason to celebrate, because it meant that we were less likely to starve. The problem is that modern society has resulted in high-calorie food being available in almost limitless supply. But our bodies are still hard-wired to treat high-calorie food as something rare. So our bodies are telling us to eat, eat, eat, and when we do we end up eating way more calories than we need, and we get fat -- which is also a survival technique to store excess calories for later famine, and which doesn't do us any good when times of famine or reduced food supply never come, and we just stay fat all the time.",
"Because in the quantities found in the wild while our physiology was developing as a species, sugars and carbohydrates were not a danger at all, but in fact, were excellent sources of nutrients. We have made it *so* easy to get these things now that we overeat them, which is the issue, and we have only had a tiny handful of generations to deal with it - and the health issues from eating too much junk food typically manifest later in life than reproductive age so even then it isn't a huge selective factor in reproduction.",
"Through most of our history, salt, sugar, and fat were rare. They are very satisfying because they signal our body that we're getting rare nutrients. Now salt, fat, and sugar are everywhere and food manufacturers have learned how to make food so rewarding that we crave more of it.",
"Sugar. Sugar was really really difficult to get. Folks graved sugar. Junk food tastes good because of salt and sugar - and other addictive shit. If you must, chicken wrap."
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