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Should I really stop drinking milk? Are Silk/Almond Milk suitable "replacements"? | [
"> I've been seeing a lot more evidence that humans are not designed to continue to drink milk after infancy.\n\nAnd yet here we are, drinking milk, as impossible as a bumblebee's flight.\n\nDon't pay too much attention to this \"evidence\". It is true that *most* mammals stop being able to process lactose after infancy, but for the large majority of people of European descent that is not the case. Unless you yourself are actually lactose intolerant, this argument carries no weight.\n\nAs to the other concerns, you can certainly look for products that are organic/non-GMO. Cows produce milk and *must* be milked, so as long as that is done humanely I don't see a moral issue there.",
"Milk, in its most simple form, is not bad for you. There are people that believe we humans aren't made to drink it after birth/infancy, but there are no cases of people dying because they like milk. The best alternative to regular milk in my opinion is almond milk. Soy milk is kind of gross, and there may be some other variables I am unaware of.\n\nThis is extremely controversial. It really depends on what you believe. Do you want almond milk for maybe less tastiness for a better feeling of eco-security? Or do you want to say \"screw those cows!\" and drink twelve gallons in a sitting?",
"Cow's milk was designed to make tiny calves explode into giant cows in a relatively short time period. It's very calorie dense. That said how many people do you know that shot up 100 pounds in a year due to cow milk consumption? Regular milk, like anything ever, is fine if you do it in moderation or aren't allergic to it.\n\nEthically, yes. Cow's milk is controversial at best. Unless you're rich and lucky to shell out for specialty products (\"Free Range! Organic!\") the milk you buy comes from factory farms where the cows don't live such great lives. Crowded pens, pumped full of drugs, all realities of the life of a cow who's milk you buy at Safeway.\n\nSoy milk or almond milk taste much the same. Almond is a little sweeter, but soy milk has better nutrition. There have been some studies suggesting \"soy is dangerous!\" But they're most all dismissed.",
"Regardless of your thoughts around cow milk, Almond milk is delicious and perfectly healthy! You can get unsweetened varieties that are great. Lots of the same nutritional characteristics of milk with better shelf life. I find that the prices are more expensive than cheap milk, but if you compare it to organic milk, the prices become comparable.",
"I'm also realizing the same thing and am very curious about it. I'm thinking of switching breakfast maybe English muffin or bagel. I've recently read that orange juice had the same amount of sugar as soda, and I've quit drinking soda a year ago."
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Why isn't everyone using hypnosis sessions or recordings to unlock languages stored in your brain, weight loss tricks, etc? | [
"Anything can work for quitting smoking, because the trick is just to somehow convince yourself that you do not want to want to smoke anymore. A hypnosis session might work just because you think it will.\n\nHypnosis sessions cannot give you knowledge you never had (like how to speak a language), and there are *no* clinically proven methods to achieve consistent and permanent weight loss."
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How/what is starting the heart when in uterus. What initiates that very first heartbeat? | [
"In human embryos the heart begins to beat at about 22-23 days, with blood flow beginning in the 4th week when the nutritional and oxygen requirements of the growing embryo can no longer be met by diffusion from the placenta. The heart is therefore one of the earliest differentiating and functioning organs^[1](_URL_1_).\n\nThe electrical stimulus that causes the [heart muscle](_URL_0_) to contract is *myogenic*, which means it arises within the heart tissue itself and doesn't require any external input.",
"The cells in the heart are special and different from the rest of the cells in your body for lots of reasons, a few of these reasons that are important are: automaticity, excitability, and conductivity. \n\nBriefly,\n\nAutomaticity: Within the way the cells are designed and coded by DNA, they have the ability to \"turn themselves on\". They can create their own electrical impulse.\n\nExcitability: If cell A receives an impulse from cell B, then Cell A has the ability to react to that.\n\nConductivity: The cells have the ability to send impulses to each other.\n\nThe heart doesn't beat until it is fully formed *KIND OF*. The heart is divided into 4 chambers, right and left, atria and ventricles (atria on top, ventricles on the bottom). Normally the blood flow would go \nR-Atria - > R-Ventricle - > Lungs - > L-Atria - > L-Ventricle - > your whole body - > rinse and repeat.\n\nFetuses are special though. They have two valves in their heart that close once they take their first breath of air. So once they've been birthed. These two valves basically make it so the top two chambers (atria) are connected, so until the fetus breathes it skips the whole lung ordeal.\n\n\nTL;DR: Heart cells tell themselves to beat for the first time because that's what their DNA says to do. The heart is beating but is actually just giving the moms blood to the fetus brain and organs because fetus isn't breathing yet. So it isn't making its own oxygenated blood."
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How is body damage on a car (dents, scratches, etc) repaired? | [
"- Most scratches can be fixed with touch-up paint.\n\n- Minor, non-creased dents can be fixed with a dent puller, basically a suction cup.\n\n- Larger dents, or creases, can be fixed with something called body puddy, or bondo-o. Essentially you fill in the dent with the puddy until it approximates the original curve of the body, sand it smooth and then paint it to match the surrounding body.",
"Depending on the damage to the car, there can be two ways a body shop will fix damage.\n\n1) Replace parts, bumpers, fenders, hood, lights etc. There are companies that make replacement parts for cars. Another option to find a replacement body part is to buy one from a salvage yard - the place where totaled cars go to be parted out and finally crushed and sent off to be processed(melted).\n\n-OR-\n\nIf the part is not damaged enough to need to be replaced, a bodyman will use a variety of tools and methods to fix the body panel. \n\nSometimes a hammer is all that is need to make the body panel line back up. If the panel has a large dent in it, sometimes the body man will weld or attach rods to the panel and use a special tool to pull on the rods which makes the dent pop out. Now these types of repair can get the body panel close, but not perfect. \n\nThe final thing a body man will do before painting the panel is to fill the panel and make it smooth. They use different types of body filler - think like clay - and once is dries it becomes very hard. Next they sand and file the filler to match the original shape. Body filler is normally a thin coat on top of the metal. \n\nThere are body shops that will simply just add a bunch of filler to a dent instead of trying to shape it back before adding filler, in order to cut corners or cheat you.\n\nHope that helps, if you wanted info on something else like painting or salvage vehicle repair, I'll try my best to answer",
"Dents are hammered out and filled in with a filler after the area is sanded down to bare metal (an inch around the dent is sanded to bare metal to feather out the paint and filler.) Body shops don't use bondo because it sucks and can lift up paint. The filler is sanded out until it blends in with the sheet metal, and you don't feel any high or low spots when you run your whole hand over it. \n\nAfter the filler is sanded smooth and all that, the area is primed, sanded again, painted, covered with a clear coat, and buffed out.\n\nIf you ever go to a body shop and they just hammer a dent out and that's it, go somewhere else because it's impossible to perfectly hammer a dent out.\n\nIf you want to know my source, it's my auto body teacher who has been in the business since the seventies.\n\nEDIT: I'm a dumbass and accidentally put a random slash somewhere."
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What makes hypoallergenic dogs/cats hypoallergenic? | [
"The part that makes people allergic to cats is actually a protein (FEL D1) found in their saliva. When a cat licks herself, she deposits the protein on her skin, and when it dries off, the flakes become airborne and trigger symptoms of allergy in people. So, it's not the fur that's the issue, it's the dead skin.\n\nIn short, there's no cat that's 100% hypoallergenic, they can only produce less of the protein FEL D1 than regular cats. Some cats tend to be preferred because of trial and error, and even then, some of the most likely to not cause allergies still do because maintenance is required (like bathing or brushing) to make those pets optimal.",
"No animal is truly hypoallergenic. It all depends on what exactly (saliva, dander, fur) has the most protein and how much the animal's activities put those things into the air. This will determine how sensitive the allergic person is to the animal. Even so-called \"hypoallergenic\" breeds (those who don't shed or whatever criteria are used) may elicit a serious reaction and other breeds or individual animals may not. This is why an allergic person even considering adopting or purchasing an animal should meet the individual animal first and observe reactions. My son is dog allergic but reacted horribly to a shih-tzu (a \"hypoallergenic\" breed) we were considering buying--but reacted not at all to our rat terrier mix. Nothing is more important when looking at individual allergies than examining the individual animal.",
"Biologically and structurally there is no difference between hair and fur. \nBoth are a outgrowth of a protein called keratin, which also makes up things like nails and claws. Fur is used to describe animal with thick coats (e.g. dogs, bears, cats, rabbits), hair is usually reserved to describe animals with thin, sparse coats (e.g. humans, hippos, elephants, manatees)."
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why can’t gravity be unified with other forces? | [
"Oooh good one. I don't have an answer but...I really hope someone does. This is gonna be interesting AF"
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Why is it that when I am standing I get tired easily, but when I am walking I can walk for much longer | [
"I'm just here to say great question. But then sometimes i stand (and do something eg stand and play guitar) and its not as tiring as just standing."
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Why does not every rain storm have lightning and thunder? | [
"Lightning only occurs in high energy storms. This means they have a lot of CAPE (convective available potential energy, often weathermen will say instability). It can rain with low CAPE, but it doesn't necessarily come with lightning. High CAPE results in storms with considerably more energy. Areas like the West Coast of the US or the UK are examples of areas that consistently have enough precipitable moisture, but hardly ever experience substantial CAPE values. Areas where it is raining out West right now have CAPE values around 250 J/KG. Tomorrow the parts of the southern plains that will experience severe weather will have CAPE values of 3000 to 4500 J/KG, or more than 10 times as much energy to work with."
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Batteries - Generic Vs. Name Brand | [
"Check for an expiration date on the Kroger batteries. Sometimes the no-name batteries have been sitting in a warehouse for years before they get put on a shelf and someone buys them.\n\nFrom my experiences buying batteries from Amazon, I've seen the big names usually put an expiration date on the pack, as if to show they stand behind their product, while the lesser brand batteries almost never have an expiration date. They don't want you to know the batteries you're buying are probably already half dead.",
"More than likely you got a bad batch of batteries.\n\nMost \"generic\" batteries that I know of are made by one of the big guys (i.e. Duracell or Energizer) and just repackaged and sold at a lower price. Yes the margins will be lower for them but they have a chance to steal sales away from one another.\n\nI used to work at an Ace Hardward and our Ace brand batteries were manufactured by Duracell. Because of this, we had to dedicate space on our shelves to Ace Brand and Duracell and could not have as extensive of a stock of Engergizer or Rayovac brands.\n\nFurther to answer your question. The batteries could have varying ages and will lose charge over time even though they haven't hit their expiration date. That could be another reason you got a bad battery.",
"The baby is also likely getting heavier. I'm curious if the name brands would lat as long now a few months on"
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Why is it when someone eats a piece of sharp cheddar cheese, they get the sensation like their forehead and cheeks are sweating? | [
"I have never encountered this and I eat sharp cheddar often, some weeks daily. I have also never heard of anyone encountering this. \n\nIf you get a flushed or sweating sensation when eating a food and it is not overly spicy then you are likely having some kind of allergic reaction or intolerance reaction and you need to get that checked out and possibly avoid that food. You can also get those reactions from being allergic to spicy foods but it is harder to tell because those reactions are normal to spicy foods even when you are not allergic."
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What exactly has Hillary done over the years to not make her trustworthy? I am 17 and want to get educated for the primaries. | [
"Hillary Clinton is what some people call a Sailor. She goes wherever the wind blows. In this case the wind is public opinion polls. If people say they dont like the trans pacific pipeline she is going to say she doesnt like it. If people say we need campaign finance reform and regulate wallstreet, she is gonna say we need campaign finance reform and to regulate Wallstreet. Its popular to talk about income inequality, so she says things about it. Yet, at the same time she is giving $200,000 speeches for goldman sachs, and has no record for anything she says. She only takes the opinion of the majority of americans, yet does nothing about it. Its popular to talk about the plight of the worker, so she talks about it, yet she was formerly on the board of Walmart, the most anti-worker corporation in existence. She has no convictions or guiding principles. She is seen as untrustworthy because she is a flip flopper. She used to be against gay marriage until it was popular to be pro gay marriage. She voted for the Iraq war and patriot act because it was popular to be for the war, not that its unpopular, she says it was a mistake. A candidate like bernie sanders has a consistent 40 year record for everything Hillary says. Bernie is seen as trustworthy because he never flip flops on issues, you know what his opinion on an issue will be before he says it because of his strong consistency on the policy.",
"Not Watergate. Watergate happened in 1972 and it made Richard Nixon resign in 1974. Hillary Clinton (and Bill) was Whitewater which involved a savings and loan giving improper loans connected to real estate deals. No wrongdoing was found specifically with the Clintons there, but it centered around Bill Clinton as governor of Arkansas overstepping.\n\nAs far as Benghazi, there have been 10 Republican-led investigations into her and the Obama administration on this one incident and all 10 have found no wrongdoings (It was an embassy in Libya where Americans were murdered). It's just something that her political opponents want to keep in the news in the hopes that it makes her look bad (contrast that with George W. Bush who was president during 13 embassy attacks that no one ever talks about).",
"Whitewater, Travelgate, Filegate, Lewinsky, private emails, lying about foreign donations, and as a personal dig her \"evolution\" on gay marriage. Don't tell me you just happen to change your opinion on something when it just happens to be politically advantageous to do so. \"Evolve\" really is the word here. You either adapt to the changing political climate or you \"die out.\" But to oppose human rights vehemently then turn around and pretend it never happened is as slimy as they come. She has literally said that, despite supposedly being for the environment, she isn't going to take a position on Keystone until she become president. It's about integrity, and no matter how much money Hillary gets from superPACs, it's something she can never buy.\n\n_URL_0_\n\n_URL_1_\n\nIf you like Hillary, you will love Bernie Sanders",
"When Bill Clinton was governor of Arkansas she suspiciously benefited from a lot of investments. For example turned a few thousand dollars into 100,000 dollars very quickly on the commodities market and then stopped investing in commodities right after that. A exec at gigantic Tyson foods later admitted he was telling her what to buy. Lots of weird deals which she made a ton of money off of all involving huge corporations operating in Arkansas.\n\nImmediately after Bill is elected she orders FBI files on the 900 most important Republicans. This is domestic spying.\n\nIn the run up to the 1996 election Bill canceled criminal background checks on immigrants to increase the number of immigrant voters for the election. During this time roughly 10,000 convicted felons who would ordinarily be rejected for citizenship were let in. Right after the election criminal background checks were reinstated.\n\nAfter leaving the white house Bill and Hillary set up a charitable fund which has taken in gigantic amounts of money from huge coorporations. The amount of money taken in is staggering and much has been spent on the Clinton's personal expenses and the huge corporations donating the money appear to have been helped by Hillary while she has been in office.\n\nThe US government has strict rules about government official's email being turned over and eventually made public. She has clearly tried to evade these laws and make permanently secret communications. As part of this she has used personal, non governmental emails to make communications which evade the reach of the rules regarding the archiving of all governmental emails. She has also used these personal email accounts, meaning ordinary email accounts like you or I use, to communicate classified information to others. This is an obvious security risk only being taken to evade the rules on disclosure of emails.\n\nThere is more. She is systematically breaking every rule which stands in her way.",
"Some people consider the use of her private email account for state work a pretty big deal. It basically means that it's possible she had official discussions that no one will ever be able to know about. Her claim that she didn't want to carry more than one phone seems pretty thing when she has a significant support staff.\n\nI think a lot of people also perceive Hillary as a calculating political operative. That is, she is willing to say whatever she needs to say to further her political career. Obviously all politicians are like this to some degree, but my impression is people seem to particularly feel this way about her.\n\nHowever, the biggest issue I have with Hillary is that she's a war hawk. She is quick to use military force instead diplomacy. She voted for the war in Iraq when she was in the Senate when it was pretty clear to anyone paying attention that the evidence that Iraq possessed weapons of mass destruction was pretty thin. \n\nI think this may have been a calculated move in that (1) she didn't want to leave herself vulnerable to the perception that she is a woman and therefore weak and (2) she didn't want to risk running against popular sentiment. So basically, in my opinion, she is either a war hawk or a poor leader. Either way, not someone I would want leading the country.",
"A lot of people consider her to be part of the two sides of the same coin (Repub or Dem, doesn't matter, same shit now) and that we need real change, which Obama really wasn't.",
"I don't know if this makes her untrustworthy, but back when she was running for senator in New York, she wore a brand new Yankee cap to the Yankee game and later that day she wore a pristine Mets cap to the Mets game.\n\n I feel like she doesn't have any opinions of her own unless she has her people do a complete analysis on which is the safest position and most popular. \n\nAlso this cringy video...\n\n_URL_2_\n\nShe just doesn't come off as a genuine person.",
"She is as phony as a $3 bill. We can go back to Whitewater etc. The best example though is how she failed the Washington D.C. bar exam. She went back 'home' to Arkansas where her Governor husband arranged for her to take the Arkansas bar exam in a private room, alone (I bet). Nobody else ever got that kind of a deal."
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If employer applications state they will not discriminate against you based on your race or gender, why do they still ask for that information? | [
"It's usually kept separate from the application, so the recruiter doesn't read it.\nThey will use it if someone tries to claim discrimination to prove they aren't discriminating.",
"Many employers are required by the Equal Employment Opportunity Commission to collect race and gender information.",
"Theoretically, identifying information like gender or race are \"scrubbed\" from the application before its given to the hiring manager. \n\nBefore that, the whole application is stored in a database, and any other files like interview scores are kept with it. \n\nIn the event that an individual or group sues the business for discrimination, either intentional or accidental, the business can pull all those files and prove that they didn't treat any applicant differently, or that their practices don't harm any specific protected class.",
"Think about it this way - if they didn't ask for your race and gender, would they need to tell you they don't discriminate? Not trying to be snarky or anything, maybe a bit humorous, but just another way of looking at it. The other answers also seem correct.",
"The government and the laws. Any HR person will tell you about all of the records they need to keep to report statistics like age, gender, race."
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Why are the cooking estimates on Frozen Foods always wrong even if you directly follow the instructions? | [
"Cooking times vary due to the variance in appliances.\n\nHowever, I've noticed that with my particular oven, stovetop, and microwave, the estimated cooking times are pretty much spot-on.\n\nPerhaps you have equipment that either cooks too hot or not hot enough to match the expected cooking time. Adjust as necessary.",
"My guess? They average out the time for a spectrum of different devices. Those devices vary greatly in power output, effectiveness etc so the remote chance that YOUR individual microwave lines up perfectly with the one(s) the testers used is pretty slim, so you end up with incorrectly heated food.\n\nThey usually include a \"cooking times may vary\" style caveat to the directions to attempt to cover themselves though.",
"Every microwave/oven/toaster is different. The instructions are based off whatever one they used to test the product with. For example if they say a hot pocket takes 2 minutes in an 1100 watt microwave and yours is 700 or 1100 but it's 20 years old and doesn't work as good as it used to, no matter how well you follow the instructions it's not exact."
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Why are South Koreans protesting and demanding their president resigns? | [
"Basically, the South Korean President has admitted to being heavily influenced by a group of women who have no place in politics. They are the mostly the wives of large South Korean business-owners who have used her power to profit and further their own agendas. Tinfoil hat aside, it's more of a cult of personality that has operated in the form of a \"shadow government.\" Citizens are quite upset because the democracy is a sham, and again, the President has admitted to it.",
"This is a pretty crazy and comprehensive read _URL_0_"
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why is oil "slippery" ? | [
"The defining property of oils is that they are [hydrophobic](_URL_0_). Hydrophobic molecules are non-polar. That means that the molecules don't really stick to anything. So when you push down on liquid oil, the the molecules just slide around."
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Pokemon cards. How are they made? | [
"Are you asking how are they physically printed, or how do the legal rights to make them operate, or who decides what pictures and text go on each card?"
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Why is it so much easier to set our biological clocks one hour back than it is to set them one hour forward? | [
"Most people are some level of sleep deprived, and can easily \"catch up\" on an hour of sleep.\n\nMissing an hour of sleep is rough, and it's still pretty rough trying to get to bed an hour earlier."
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How come when I log in correctly, my computer instantly let's me in, but when I type it in wrong it takes 2 seconds before telling me it was incorrect? | [
"This is actually a security feature - it slows down attackers. If they're trying a bunch of different passwords that might be yours (this is called a \"brute force attack\"), then making it take a couple of seconds to fail means it will take the attacker a ***LONG*** time to try a significant number of passwords. Then it's more likely that someone will notice what they're up to and can stop them before they actually get anything."
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Why doesn't McDonald's food decompose? | [
"It does. Those videos are very misleading, and involve fast food that appears to decompose very little only because it is kept in dry conditions (meaning that it dehydrates and essentially mummifies), and then opposed to food kept in more humid conditions that decomposes very rapidly. \n\nIt's complete BS."
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How do we know that ancient languages are interpreted correctly? Same for making first contact with secluded tribes. Is it based on assumption? | [
"Yarr! Yer not alone in askin', and kind strangers have explained:\n\n1. [ELI5:How do historians or linguists decode and translate an ancient language that hasn't been spoken in a long time? ](_URL_3_) ^(_23 comments_)\n1. [ELI5: How do we know that our translations of hieroglyphics are correct? ](_URL_1_) ^(_ > 100 comments_)\n1. [How linguists are able to translate an ancient languages? ](_URL_4_) ^(_26 comments_)\n1. [How do modern humans take ancient language and figure out what it's conveying? ](_URL_0_) ^(_3 comments_)\n1. [ELI5: How do we translate languages of ancient civilizations? How much of them can we translate at all? ](_URL_2_) ^(_10 comments_)\n1. [ELI5: How do people decipher ancient writing systems? ](_URL_5_) ^(_5 comments_)"
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Why does TV shoot in 16:9 and movies shoot in 2.39:1 | [
"Former Movies theater projectionist here, Movies are shot in 1.85:1 (flat) and 2.39:1(scope/Anamorphic). During the days of actual film in movies theaters, 35mm film size was the standard in all theaters. They were marked scoped or flat which told the theater projectionist to use a standard lens for flat(16:9) or a anamorphic scope lens for the movies, this mixed with a masking system for the screen to open wider for scope movies and move inward for flat movies. \n\nSo Flat movies in the theater are very close to 16:9(1.78:1) used in the home. \n\nSo if tv's were actually 2.35 and TV show started to used 2.35 there would still be movies that now would display black bars and the left and right on those TV's. I would imagine if this was the case more and more movies would begin to shoot in 2.35 but in the end the film maker has an artistic choice as to what aspect ratio to shoot in",
"Cinematographer/Film Editor here: Some of the other answers nailed it in terms of the origins of the split, particularly the shift from 4:3 to 16:9, but also, the anamorphic lenses that create the 2.39:1 aspect ratio are REALLY expensive. So that, combined with the fact that televisions are already 16:9, television shows are shot standard at 16:9. Higher budget films will shoot on anamorphic lenses to create that \"cinema\" feel because theaters can re-orient their screens from 1.85:1 to 2.39:1 quite easily, whereas lower budget films will stick \"standard\" lenses on the camera to capture 1.85:1. The 35mm stock, as previously said, is a 4:3 aspect ratio. So the 1.85:1 film is cropped, but the more expensive anamorphic lens stretches the image vertically to fill all of the data and then it's widened by either a lens on the projector, or digitally de-squeezed for digital release. Hope this helps :)",
"Movies used to be shot in a 4:3 aspect, which is the same dimensions as standard 35mm film frame. After WWII, television became more popular, so film studios starting rolling out movies in 1.85:1, 2:39:1 wide-formats such as Cinemascope* to compete with TV.\n\nAfter about 2004, TVs began switching over to a HDTV 16:9 format (1.77:1) because they could hold more picture information, as well as transfer films without using the awful \"pan and scan\" technique. \n\nA good example of all this would be HBO's The Wire. The show was shot on 16mm film, and then was cropped down to 4:3 to display on TV. Now that HBO broadcasts in HD, they remastered the old film (nearly) uncropped to 16:9. \n\n*This was done by either masking the top and bottom of the film frame, or by using anamorphic lenses to \"squeeze\" a widescreen image onto a 4:3 film frame. \n\n(Not all movies shoot 2.39:1/2.35:1, in fact, many are 1.85:1, which is very close to the 1.71:1 of HDTV)",
"to add just a fun bit of confusing info, 2.39:1 is relatively new in terms of implementation due to the accepted formats for the Dolby digital projection servers. 2.35:1 and, though less common, 2.40:1, were kinda compromised into 2.39:1. last I checked the DCI spec still only allows 2.39:1 and 1.85:1 as native formats.\n\nTheres also lots of movies in 1.85:1. look at the back to the future movies, or the first Avengers movie (which was odd, since everything leading up to that was all scope)"
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As a 27M who has smoked since the age of 16, how much of a recovery can my body make from quitting, how long will it take? | [
"When you quit smoking, the inflammation in the airways goes down. The little hair-like projections in the airways that we call cilia begin to work again. So the lungs will get better in weeks to months. Breathing will get better. Exercise capacity will get better. Paradoxically, people find that they cough a little more right after they stop smoking, but that's natural. That's the lungs cleaning themselves out.\n\nBut if you've been smoking a long time and have developed any chronic obstructive pulmonary diseases, the lungs will never totally heal, for example - Chronic bronchitis. It is an inflammation of the airway, Some of that inflammation can be reversed."
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Why do governments allow car makers to advertise diesel cars as CO2 friendly (less than 100 g/km) if they pollute far more than similar petrol engines? | [
"Diesel engines are generally more energy efficient than petrol engines, i.e., they are \"CO2 friendly\" as you put it and so contribute less to global warming. What's wrong with being able to advertise that?\n\nDiesels do have more of a problem with some types of pollution but that's in many ways a separate issue."
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if traits like Hypertrichosis (werewolf syndrome) or Polydactyly (extra fingers) are dominant traits, why aren't they more common in the general population? | [
"Just because something is a dominant trait doesn't mean it will end up spreading to everyone thanks to our old friend natural selection.\n\nIf having a trait, even a dominant trait, causes you to be less likely to survive and pass on your genes, it will eventually be weeded out of the gene pool."
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Is there any way to find the curve of the earth using Geometry, if so, how? | [
"Early calculations used the sun and shadows to help calculate the curvature of the Earth. Eratosthenes did this calculation using the shadows cast by the sun to find the angle of the earth's curvature, then he used the distance between those points to estimate the circumference of the Earth. He was fairly close, he guessed it was 25,000 miles when it's actually 24,902 miles.\n\nIf the points aren't on the same line of longitude (North/South), then you can still do it. In Euclidean (flat) space, triangles have 180 degrees. On curved surfaces, this isn't always true. Draw a \"triangle\" on the surface on the earth with two points on the equator and one on the North Pole. The angle between the points on the Equator and the North Pole is 90 degrees (the equator and lines of longitude are perpendicular). Just those two angles will be 180, and we still need to add the angle at the North Pole. Knowing these points, we can know the relative sizes of the triangle in terms of the sphere. Plug in one of the side lengths and we can know the sphere's curvature."
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Why do we still use gunpowder in ammunition instead of other explosives that have a much greater energy to volume ratio? | [
"No matter what explosive we use in guns, we'll still call it \"gunpowder\" even if it's not a powder. It's just a name that stuck.\n\nBut we've actually changed the formula several times. With small arms, you actually want to limit the speed at which the agent explodes, if you can believe it. Too much energy too fast, and you have to compensate with a stronger, heavier barrel. If you can time it just right, then the explosion provides continuous pressure for the duration of the slug's trip down the barrel.\n\nModern 'gunpowder' is designed that way. Rather than just being the simple black powder that Captain Kirk cobbled together to kill an alien lizard-man, it's now little pellets optimized for stability, timing, reduction of smoke, and power.",
"except you don't want an explosive. you want a combustion. explosive would expand too fast. you want a controlled combustion and expansion so you don't create too much pressure in the chamber and blow out the steel barrel and end up with this:\n_URL_0_\n\nor worse, a bomb with steel shrapnel flying into the shooter's face."
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What is a broadcast domain? | [
"Each network has a broadcast address - if packets are sent to that address, they will be sent to all hosts on the network. The broadcast domain is simply the set of all hosts that will be reached by a broadcast on the network."
] |
If human skin 'regenerates' itself within ~35 days, why don't tattoos disappear along with it? | [
"Tattoo ink penetrates through the first layer of skin, the epidermis, into the deeper layer - the dermis. The epidermis is the layer that routinely sloughs off old skin cells. The cells of the dermis are far more stable and does not shed like the epidermis leaving the tattoo intact."
] |
Hydroplaining | [
"Hydroplaning refers to when your car basically starts surfing.\n\nSometimes in the wet, an amount of water can build up under your tire and actually prevent the tire from coming into contact with the ground; it's sort of the same thing that happens, as I said above, when someone goes surfing on the ocean.\n\nBlack ice is dangerous for a similar, but not the same, reason. Black ice is, well, *black.* Actually, it's clear. It's so clear that it's almost invisible, which means the black of the asphalt shows clearly through it and makes it very difficult to see.\n\nIn large part, that's because it's so smooth. Which means that when you drive over it, you have very very little traction, and your car starts to slip. If one or two tires start to slip before the other ones, this can induce some rotational motion in the car--you start to spin out. Lastly, when you do get back on the asphalt... well, a lot of times people start spinning the wheel to try to gain control, which means that as soon as the car hits asphalt again the wheels are pointed off to the side and they drive right off the road or into traffic.",
"Hydroplaning and sliding on ice are two different things from my understanding. Hydroplaning is when the car hits a puddle of water and at the speed it is traveling it skims along the top instead of actually pushing the water out of the way. That is why they tell you to let off the gas and not hit the brakes when hydroplaning so the car can settle back down on the road slowly and regain traction, if the brakes are slammed and the tires lock it can cause the water to build up in front of the tire and further increase loss of control. A sliding tire is much less effective than a rotating tire.\n\nIn the case of black ice the tire doesn't have traction along the top at any speed and depending on slope and steering angle the whole car can lose traction and slide off the road or into other cars. The problem with the ice is that once sliding on ice it is very hard to regain steering. Even if you can stay relatively straight, when you come off the ice back onto pavement the sudden gain of traction can cause many people to crash as well. For instance if the steering wheel is turned to keep you straight when on the ice as soon as you come off the ice and those front wheels gain traction you are going where they are pointed very quickly which many people do not prepare for. Hopefully this helped a little bit, I'm sure others can chime in and build on what I said",
"Just a clarification (I hope). Whenever something moves along the surface of the water, a wave is pushed ahead of it. If the thing moves fast enough, it can actually go over the top of that wave (as had been said, surfers). \n\nThe tread in tires is intended to give the water a place to go. The flat part of the tread is on the road and the water is 'squished' into the grooves. As the tire wears, the grooves become shallower and less water can be forced into them. That's why tread wear indicators are molded in the tread. If the raised portion of the tire has worn enough that it is visible, the grooves are not deep enough and the tire needs to be replaced.\n\nSlick tires like race cars use assume they won't get used in the rain."
] |
If a supersonic jet has a flattened "nose", will the sonic boom be louder? | [
"The loudness of the sonic boom is essentially proportional to the amount of air the aircraft displaces at or above the speed of sound. If the nose affects how much air the plane is actually displacing, then it will change how loud the boom is."
] |
Why is it easier to balance on a moving bike than one at rest? | [
"So, everyone so far has mentioned inertia and the gyroscopic effect. While these do have an effect, they aren't what keeps the bike from falling over. Simply put, the mass and speeds of the bike aren't enough to counter act you falling over.\n\nThe true reason why you don't fall over is centrifugal force. If you were to start to lean to the left, the bike starts to take a curved path. This generates a centrifugal force which pushes the top of the bike back to being vertical(on a straight path). Here's the link to an actual [paper on this topic](_URL_0_). If you don't have a math/physics background then you can just jump to the end of it and read the first paragraph of the conclusion."
] |
What determines how fast a person metabolizes alcohol? | [
"The average male metabolizes .015%-.020% of their BAC every hour. Three pints of 4.5% ABV beer would put you at .086, or just over the legal limit to drive. 3 hours later would put you at a BAC of .041-.026, the lower end of that estimate being not only well under the legal driving limit, but under the BAC that people even tend to feel \"buzzed\" at. You're sobering up at a completely normal rate, it's not unusual at all for someone of your weight to not feel anything after 3 hours.\n\nNow, if you had slammed down a six pack and 3 hours later still felt totally sober, that would just be you having a high tolerance. Sometimes it comes from routine drinking, some people just have it affect them less. Mind you, high tolerance DOES NOT affect your BAC or how fast you can get it out of your system, it just affects how you feel at a given BAC level. You would, in that case, be skirting the line almost exactly at a .08, but even if you passed a roadside \"walk-the-line\" test would still technically be over the limit and could get nailed for a DUI on that.\n\n[Here's](_URL_0_) a good calculator that lets you fine tune the settings. I wouldn't use this to decide whether to drive or not, but if you've ever wondered how long it would take you to get your BAC down after a given quantity of alcohol, it can sort of give you a clue.",
"What is your weight, height, and gender? Do you drink on a regular basis? Did you eat while you drank the beers?"
] |
how did el Chapo and his helpers dig the hole into the prison without anyone noticing? And how did they get such a perfect accuracy on where to come up (precisely into the hidden part of his cell)? | [
"I watched a documentary about El Chapo and the consensus seems to be that Mexico is so corrupt that he surely bought off people. It was an inside job.",
"Because giving him the key and having him walk out the front door would have been too obvious",
"I think the tunnel is just a diversion. He walked out of the door, and the \"tunnel\" version is just for good television, and keep Mexicans entertained while the novelty wears off. \n\nA few months later the investigation will conclude that the Chapo walked out through the main door, and he got to say Goodbye to everybody.\n\nIn a few years, a \"new\" investigation will say that the Chapo might have escaped *before* the news reported it. \n\nIn about 10 years, a reporter will interview all the guards who worked at the prison while the Chapo was there, and will find out that el Chapo would come-and-go as he pleased. that he never was fully imprisoned, he lived better than most people, he had prostitutes and drugs delivered to him, and low profile yet high rank politicians would visit him in private.",
"Well, there's still an investigation going on, so nobody can really say for sure.\n\nBut it's not a big stretch to say that people on the prison staff could have been paid off, threatened, or blackmailed to help, or at least turn a blind eye. El Chapo has resources, and you'd be surprised what lots and lots of money and a handful of scary-looking henchmen can get done.",
"I'm sure anyone who was in a position to hear any of the digging had their ears stuffed with cash... or their family's ears stuffed with bullets.",
"For tunneling they have engineers working for them and where needed use industrial tunnel digging equipment. His cartel brings in $3,000,000,000 of revenue each year.",
"I guarantee everyone in that cell block noticed. This cartel's calling card is massive networks of tunnels. They use them to traffic their merchandise and also as escape routes. El Chapo has escaped before through networks of tunnels connecting adjacent houses in neighborhoods. As far as accuracy...GPS I presume. \nFinally, if El Chapo come to you as a prison warden or guard as asks for help escaping...you will take his bribe.\nHe will pay you and your family in silver(cash)....or he will pay you and your family in lead(bullets). Its up to them to decide.",
"In order for the tunnel to come up precisely in his cell they had to have had access to the prison's blueprint.",
"The drug cartels in Mexico are so powerful that they basically run the country. You see it all the time in the news \"x drug cartel leader captured\". If I were to guess, it's all just for show to trick the public into thinking something is being done, because the headline a couple weeks later is \"x drug cartel escapes\". Essentially, they're so powerful he pretty much just walked out of prison, like you said it yourself, how did no one notice? Thing is they all \"noticed\" but they can't do anything about it or else they + their families = dead. \n\nFun fact, el Chapo leads the Sinaloa cartel, and it was discovered that the DEA was working with them, and basically let them continue their operations in exchange for information. That just shows you how powerful they are, that a department in the US government is working with them. If you still have any doubts about how powerful drug cartels are, in 2012, 50 bodies were dumped on a freeway with a sign that basically said \"The Zeta's cartel did this\", and nothing happened, because the cartels know they run the show.",
"According to a news story I saw the other day, there are more than 30 people who were suspected to have been involved with the escape. It was almost certainly an inside job.",
"If you were a prison employee with a shit job and hit pay and some billionaire offered you a few million to help him escape would you not take it?"
] |
What are those jets for in the sky, and why do they leave behind a trail of white behind them? | [
"The airplanes are for transportation of goods and people. They fly very high to reduce drag with less-dense air and to avoid other planes.\n\nThe trails are kind of like little clouds made from the stuff in the air swirling around as the airplane moves through it. These are called contrails.\n\nThis is kind of the same effect you get as you drag your hand through water and cause the swirling ripples. Some differences are the density of air and water, the particulates like dust and water vapor in the air, and the size and speed of the wings on the airplane.\n\nIt is not chemicals or exhaust, except in the cases where that's the purpose, like in an air show or while crop-dusting. You can tell this is not what causes the contrails as those chemical trails dissipate very quickly while contrails can last for a long time.",
"The jets can be any number of large planes that fly at high altitudes. Cargo, commercial, etc, and many are at 35,000+ feet above sea level because there is less drag due to the thinner air. The trail of white is called a \"contrail\" and they are made of frozen water vapor that is frozen around particles that come from the exhaust."
] |
Why have all the 'big' animals and creatures gone extinct? Megalodon, the Dire Wolf? All these creatures were huge, top of the food chain predators but now don't exist? Yet the sloth; slow, dumb and effectively defenceless has somehow managed to survive? | [
"As per your example, a sloth survives on plants. It uses no energy because it virtually doesn't move. A sloth goes SO slow it actually can have moss grow on its fur. When predators hunt they go for sounds and sights. A piece of moss isn't that inviting. These animals survive because they're specialized to survive. I would guess that enormous apex predators are a burden on the environment and therefore when foods can't be found in enough abundance they die off (also note that most if not all extinctions for the past 10,000 years have been directly influenced by man).",
"This is at least partially a statistical phenomenon: We can look back at the entire history of life and see all the large animals that ever existed. If anything, our record is biased, both because larger fossils are easier to find and because we just like them more. So to us, it looks like there's been tons of large animals. But remember that we're looking at (for animals) over 500 million years of time. Given that we live in a random instant in that history, why should we happen to coincide with the existence of these large animals? Even with this in mind, there are some large animals around: the blue whale is the largest animal known to have ever existed.\n\nAlso, don't be so down on the sloth. That highly energy-efficient lifestyle is a pretty good adaptation to its environment.",
"Changing conditions mean that the strategies that the megalodon once used to survive no longer worked. The oceans warmed up and many of the megalodon's whale prey went extinct. The whales that replaced them were too fast for the megalodon to catch.\n\nOrcas and sperm whales today fill the niche that the megalodon filled before."
] |
What would happen if a country cut the value of its currency? | [
"it's happened alot with countries with out of control inflation. Iran did did it. they just dropped 3 zero's. i think congo did it too. dropped like 6 zeros.",
"The denomination of the currency is basically irrelevant to its value. So if you could change the denomination instantly including on legal contracts and exchange rates it would all work out without any gains or losses by anyone.\n\nUsually if you wanted to do this in practicality it would involve a process of introducing a new currency which the old currency could be exchanged for at a certain rate, then gradually phasing out acceptance of the first currency until you finally ended it and switched the new currency to the same name and symbol as the old."
] |
How galaxies can be hundreds of light years away, and yet we can still photograph them from earth? | [
"First, it is important to level set on the distance. The closest galaxy to the Milky Way is the Andromeda galaxy. It is around 2.5 million light years away. A light year is the distance that light travels in a year. Since light travels at roughly 300,000,000 meters per second, a light year is a very far distance. \n\nNow to answer how galaxies such distances away can be viewed and photographed. Time. The universe has been around for billions of years and has been expanding during that time. This means that billions of years ago when the light was emitted from very distant galaxies and started making its way to Earth, it didn't have as far to travel. This is how we can see things that are farther away in light years than the age of the universe.",
"What you capture in the photograph is that many light years old. The star may not even be there anymore. \n\nIt's easier to get with sound: think of a thunder. You first see the lightning and hear the sound a few seconds later. The sound happened at the same time, and when you're hearing it, the lightning is no longer there.",
"Because when you look up at the galaxies, you're seeing them as they looked like millions or billions of years in the past. We don't know what those galaxies currently look like. For all we know, that galaxy could have collided with another galaxy and looks completely different from the images we are gathering of it.",
"Hundreds? [Try *billions* of light years](_URL_0_). There is nothing in space to stop light so it travels forever and the universe is really, really, unbelievably old.",
"When you photograph something, light does not have to travel all the way there and back before you can see it. Rather, you can see the stars from earth because light has traveled from there to here over hundreds of millions, or billions of years\n\nIt's similar to how you see. Your eyes are not the source of the light, they are the observers of it. They see the light that has traveled from the stars to here, and thus they see the image of the star as it was hundreds of millions of years ago. Thus, when you photograph something, you take the photograph of it in the past, when light from that object began its journey towards your eyes."
] |
Can i kill someone when shooting an AK or similar in the air and the bullets drop lets say in a big crowd? | [
"yes, but it's not the most efficient way to do it. You are much more likely to be successful if you aim directly at your target.",
"Yes, there have been many injuries related to celebratory gunfire.\n\n_URL_0_",
"[Mythbusters answered this](_URL_1_). Basically yes, you can kill someone if you fire a bullet up, but if, by some chance you managed to fire it perfectly up with no angle, it would fall at a less the lethal speed.",
"To add to what everybody already has said. The bullets that are fired at an angle are the most dangerous. Any time you fire a gun in the air you are taking a chance. There may be a 1/100,000 chance that it injures someone based on your location and other factors such as weather and caliber of the bullet. But the problem is most people don't just fire one bullet. If you fire 100 of them you are already looking a 1/100 chance of injuring a person. Go up to 1000 and the odds are very good. Even if you fired 100,000 bullets that would not guarantee that you would injure someone. It's just that the odds would be very high (almost 100%). You may have injured 2 people by then or it may take another 100,000 bullets to injure somebody at that rate. \n\nThe bottom line is the more bullets you fire the more likely a potentially fatal accident can occur.",
"Not if you fire the bullet straight up. If you do, the bullet only has momentum in the X direction. It will rise until gravity has sapped all that momentum. At that point, for an instant, the bullet will not be moving and have zero momentum. \n\nThe only energy the bullet will have now is potential energy from gravity, much less than the energy from the explosive in the cartridge. It will now fall only aided by gravity, which considering the light weight of a bullet, will not be enough to kill. Particularly since it will not fall pointy end down.\n\nThe problem comes in when bullets are fired in an arc, if you truly fire exactly straight up you would be okay, but of course how likely is some yahoo firing wildly into the air to be to get the gun at an exact right angle to the earth?"
] |
Why is the pain of having sore muscles somewhat enjoyable? | [
"If I tell you that the pain you feel in your muscles after a workout is the pain of your body tearing itself down to rebuild itself better, how does that make you feel?\n\nIf I tell you that the pain you feel in your muscles after a workout is your body developing cancer, how does that make you feel?\n\nAnd there's your answer.",
"Ok, I will sound too simplistic but, Pride. Pride in yourself that you just accomplished a great work out. That you succedded.\n\nThat's probably the reason why for most people.",
"When you tear muscles, your brain releases endorphins as a painkiller, which has an effect similar to morphine.\n\nSo what you are feeling is being \"high\" on the endorphins."
] |
Why do companies pay dividends to stockholders? | [
"You pay dividends to make your shares attracive to own. Many people buy shares hoping they will increase in value others want an income from owning the shares in addition.",
"When you buy a stock in a company, you become a partial owner of that company. At the end of each quarter, the company must report their earnings to the public. As a partial owner of the company, you are entitled to your share of this profit. Now the company has two options with this money. They can pay keep the money in the company and reinvest it in the hopes that it will make more money for the company, or they can pay out their earnings to the stockholders (owners) in the form of dividends. This decision is made by the board of directors, which is elected by the stockholders. Most companies choose to reinvest their earnings during their first few years as a public company (think google and amazon). Meanwhile more established companies (GE, Microsoft, Exon) will pay out dividends.",
"Because that's the entire point of owning stock in the first place! Owning stock means you own a portion of the company. The whole point of owning a company is to make profit. When a company makes profit, it has the option to divide the profits. That's what a dividend is! How else are you going to pay yourself?\n\nedit: just read the other questions\n\nYou can pay them out monthly, quarterly, annually, whatever is convenient. \n\nDeciding how much: well you should probably make sure your bills are paid first. Whatever is leftover you can either keep in the company bank account for backup or future investments or split it in the form of a dividend."
] |
Why is bottled water more popular than canned water? Why are cans of soda more popular than bottled soda? | [
"Can't say for sure. My guess is that it is mostly a marketing tactic. A clear bottle gives the impression that the water is purer (and healthier) than a can. With soda, it doesn't matter really. Both bottled and canned soda sell, so they make both. Canned water probably doesn't sell nearly as well as bottled. \nAdditionally, a can is useful because it able to be pressurized. You may have noticed that soda bottles are thick and strong. This is to withstand the pressure. Water bottles are thin and weak. They don't need to withstand pressure to the degree that a soda bottle does. This cuts down on costs. You can use a tiny fraction of the material. \nTL:DR it is a combination of how people perceive bottles vs cans as well as unpressurized bottles are cheaper than cans."
] |
Why can't we make computers that use regular English (or just a human language at all) to do things instead of all this code like Java or C+? | [
"Step 1: place the cup on the table\n Step 2: move it 1 inch to the left\n\nDid you just move the cup 1 inch to the left? Or the table?\n\nAmbiguity like that is common in \"natural\" languages, but is no good for a computer language.\n\nThis is just one of many reasons why computers have such a hard time understanding natural languages. But people have been [working on making it happen for decades](_URL_0_).",
"In order for a human language to be understood by a computer, a compiler that translates human language into machine language must exist. The problem with making a compiler for a human language is that the languages people use are filled with inconsistencies and lack enough standardization for a compiler with any sort of usefulness to exist.\n\nIf you were to attempt to take a human language and modify it so that a computer could understand it, you would end up removing any possible ambiguity, coming up with standard ways to express different operations, and defining the syntax of the language in such a way that a compiler could translate any valid sentence into machine language. You'd end up with a programming language.",
"One of the design aims of the Cobol language was exactly this. \n\nHowever, in my opinion, natural languages are too ambiguous to issue the exact instructions needed to make computer programs do what you want them to do.",
"English is too ambiguous. Computers can't understand the subtleties and contexts involved with a real language. They can only understand computer languages where everything has a specific and exact meaning.",
"English is very vague and when you're trying to make a computer do the same thing all the time it's the worst. Also it's kind of verbose for when you want to do the same simple thing all the time.\n\nAsk anyone who's ever tried using [AppleScript](_URL_1_). It was supposed to be very english-like, and thus easy to learn. But the fact that its syntax is flexible and highly optional mostly makes it maddening. Nowadays there are ways to use Python or Javascript instead, which at least are more precise."
] |
Why do I hear so much about censorship in Australia? How did they get to be so strict about what they censor? | [
"1. Why do you hear so much about it?\n\nBecause your journalists had a slow news week.\n\n2. How did they get to be so strict about what they censor?\n\nHonestly, age. We have a large baby boomer population that votes again and again to keep the status quo. For the longest time we weren't actually censoring video games that didn't meet our MA15+ classification but because we didn't have anything above MA15+ for video games as a whole.\n\nSo they were deemed RC(refused classification) and banned from sale. It's less malicious and more carelessness on our part.\n\nWe are still not quite as bad as germany or china but sensationalist media and click bait writers are fearful of both it would seem.",
"As an American I can't say, but I've wondered about this myself because I'm a gamer, and I remember thinking it would suck to not be able to buy mortal kombat. Then I realized that it's backwards here, not in Australia. If everyone is so worried about the influence of video games on people, isn't it better to include sex, a natural act that creates life, rather than killing, an obviously life ending thing?\n\nThen I realized I'm over 18. If anyone's going to censor me, it's gonna be me, not my government. If I wasn't 18 it would be my parents, not my government. Otherwise, something is painfully wrong.",
"it was really anoying in l4d2 as the censorship made the game harder as the main way to tell if an infected was dead the giant gaping wound was absent \nexample l4d1 you shoot an enemy with a shotgun they ragdoll\nbut in L4D2 the keep running for a sec and eventually drop dead but without the visual cue of the wound you keep shooting wasting ammo",
"I don't know why this always comes up. All I can think of are two things that people might keep coming back to.\n\n1. Game censorship- we now have R18+ rating so this isn't really an issue anymore, not that it was to begin with. Seemed like an attempt to appease the Christian and Family groups, because if someone wanted the uncencored version of the game, they will bought it and no one has done anything to stop them. It's just a non-issue.\n\n2. Some thing about porn with women with small breasts that look like children. I don't even know what happened to this because it clearly hasn't affected things one bit, people like to bring it up but I can't see any measurable instance of it in real life. Porn is on the internet, how would you expect one to stop people looking at something on the internet?\n\nTo be honest, compared to America I believe we get away with *more* in fact. Just comparing Aus and US, it seems we get away with more swearing and nudity earlier in the day on both TV and radio. It also seems we're less...uptight I guess with innuendos and swearing and stuff even during daylight programming (morning-7pm)\n\nGuess it's just a matter of perspective and what you hear about on the internet without spending time in both places.",
"FYI we do now have an 18+ classification & many games that were previously banned or refused classification have been \"re-classified\" and are on sale in stores.",
"_URL_0_\n\nAlso a exhibition my girlfriend worked on\n\n_URL_1_\n\nBasic summary of the radio program is, Australia decided the British were becoming too decadent and decided they were to be the last outpost of British values and decency..\n\nThey decided to outprude them prudes.."
] |
What is RAW picture format and why is it useful? | [
"RAW is a direct dump of the information coming off the image sensor of your camera with no processing being done to it at all. The main benefit is that you can do a lot of image processing on RAW that you wouldn't be able to do with JPEG files. A [picture like this](_URL_0_) will show you what's capable.",
"ELI5: Imagine if your camera was a guy named Cam. You'd say, Cam describe that rainbow to me.\n\nJPEG: Cam would say okay, get some crayons, and draws you a picture.\n\nRAW: Cam would say okay, I saw some red over here. And some blue over here. And some green at this spot. Here's what crayons I would use to draw it. You don't have to use these crayons though.\n\nYou can then pick and edit the picture's colours yourself. Or choose how bright you wanna make the picture. It'll still be the same picture, but you won't be stuck with what crayons Cam picked.\n\n(Downside: lot more memory for Cam to describe what he's seeing and how he's seeing it. Upside: more control over things like exposure, colours, etc.)",
"It's basically an uncompressed file format. Normally, your camera will compress the image as a JPEG to make it a smaller file size, so that you can fit more images on a memory card. This is fine for general everyday use, but the quality of the image will not be the best.\n\nIf you are a professional, you want the *best possible quality* that your camera can record. That's where RAW comes in. It allows the image to be stored on the memory card **exactly** as the camera recorded it. The trade-off is that the file sizes are HUGE and therefore you won't be able to fit as many images on your card as if you had used JPEG.\n\nAnother benefit of RAW is that you can easily perform adjustments to the image later, such as changing the white balance, etc.",
"If you want a film camera analogy the RAW image is like the negative and the JPEG image is like the prints. The RAW is exactly what your camera saw when it took the picture, while the JPEG has had all the camera settings (white balance etc.) applied to it and then smoothed over a little (noise reduction, JPEG compression)\n\nFor a more ELI15 answer:\n\nThe RAW file is uncompressed and has more bits per pixel. In a JPEG image each pixel is made up of red, green and blue values from 0-255 (256 possible shades of each color). In a RAW file each color can be from 0-4095, or in some cameras even 0-16383. \n\nThis has the advantage that you have a lot more shades to work with if you want to adjust the image after its been taken. If you took an image that was much too dark in JPEG the color values may only range from 0 to 60, so if you tried to make the image brighter you'd still only have 60 shades which wouldn't look very good. With RAW that same image would have recorded values from 0 to 1000, so you'd still have 1000 shades (more than your monitor can display) so the image would still look good.\n\nIt's also much easier to change the white balance on a RAW file, as it's saved before white balance is applied. If you get the wrong white balance in JPEG you may end up with an image that's much too yellow, and you can't get the blue back. With RAW the full amount of blue data would still always be saved.\n \nThen there's the noise reduction and compression, JPEG works by throwing away tiny details from the photo to save file size and noise reduction can smooth over details even more, while RAW keeps the entire photo almost unaltered.",
"Could someone recommend a program that handles RAW format files that's easy to learn and use?",
"RAW format is an uncompressed version of an image as opposed to jpeg or png. It is used by photographers and printer mostly due to its clarity. The downside of this is despite looking awesome it takes up a huge amount of memory."
] |
If copper is self sterilizing, why doesn't every hospital make door handles, and other frequently touched objects, with it? | [
"A couple of reasons.\n\n1. Copper is very expensive compared to other materials.\n\n2. Sanitizing cleaning solutions are relatively inexpensive, and even with self sterilizing surfaces, these areas would still be cleaned regularly.\n\n3. In order to properly self sanitize, it usually takes a minimum of around 2 hours. Something like a door handle is going to be touched more often than once every two hours, so its effect isn't going to be as helpful as properly sanitizing the handle or hands.\n\n\nReally though, the cost is the largest reason. While KingPupPup is right in the copper oxidizes, frequently handled copper will not because the constant friction will wear away the patina.",
"Because copper oxidizes and turns green. [Example](_URL_0_)\n\nEveryone's hands would get covered in green stuff.",
"Actually this is a thing now: \n_URL_3_\n\n_URL_3_\n\n_URL_3_",
"Some of these other comments are discussing why it hasn't been done in the past, but the reality is that people are experimenting with copper nanoparticles for this exact application. In fact, I was just at a toxicology conference today where this was discussed. \n\nHere are some relevent links - _URL_4_\n\n_URL_5_",
"actually, some do, it is being deployed in several operating rooms right now. It turns out, the bigger benefit is not in the sterile surface, but also that copper keeps the air cleaner as well. For this reason, it is worth installing in rooms where the air should also be clean (burn clinics and operating rooms mainly.)\n\nA oxidation resistant tempering is available, and sold for some high price to hospitals. \n\nEvery hospital can't afford it, but, as resistance to common disinfectants increases, more hospitals are resorting to tools such as elemental surfaces. Silver is another one that works, but I do not believe it has coppers aura effect.",
"ELI5 how copper can be self sanitizing? is that how the most expensive antibacterial layer containing tooth brush works?",
"Because it is too soft, and also very expensive. Fortunately there's a start-up in Toronto that has patented a way to use a copper alloy as a spray coating. They managed to find a way to retain the antimicrobial properties. Awesome. I'm looking forward to a less germy future: _URL_6_",
"There are strains of pseudomonas, found both in farm fields and in hospitals, that are copper resistant or even copper thriving. \n\nI think that guy from jurassic park said something about this.",
"Because it's easier, more effective and cheaper, to just make medical equipment that actuall goes in your body out of those materials.",
"Aside from oxidizing issues, it's a rare allergy. Not super rare, but there's plenty of people out there.",
"This is not about the album by the band \"Live\" is it?"
] |
How will Netflix use data to determine if they should do a Punisher spin off or not? | [
"How many people watch multiple Netflix originals of other Marvel shows. \n \nIf many people who watch DareDevil also watch Jessica Jones, and will also watch the upcoming Luke Cage/Iron Fist/The Defenders, that is a good indication they will also watch Punisher."
] |
Why does the expression "... like it's going out of style" mean that you're doing it a lot? Don't people do/use things LESS as they're fading in popularity? | [
"It's implying that they know that X will be unpopular soon so the person is basically trying to get the most out of whatever X is while its still considered acceptable.",
"It's a confusing phrase. But here is the logic: if it's indeed going out of style, you better use up what you have now before it goes completely out of fashion. Hence, in your using up of those soon to be useless resources, you're doing it like it's going out of style."
] |
What are the responsibilities of movie directors and producers and what differences do they make? | [
"The director is responsible for maintaining the vision of the production. This person generally works as a creative bridge between the writer and the performers/production crew. Sometimes there are several more specific directors who are sort of sub-managers for different aspects such as visual effects or sound.\n\nProducer is a much less specific title and is bestowed upon a range of people, largely to improve that person's prestige. The historic role of producers is to manage the business side of things. They manage the money, arrange for locations and facilities, and make or approve many of the personnel decisions."
] |
How can the Sandy Hook victim families sue Remington for manufacturing a product? | [
"> I get suing the shop if they failed to run all required background tests but I just don't understand how they're able to do this?\n\nHere's the thing. The shop ran all the background checks they were supposed to on Lanza's mother.\n\nThe shop couldn't do a thing in the world to stop Lanza from murdering her and taking it.\n\nWhat the Brady Center is relying on is something called \"negligent entrustment,\" which is legalese for \"The manufacturer, distributor, and retailer knew or should have known that they shouldn't entrust such a dangerous, high-powered death machine to civilians.\"\n\nIt's bullshit, and it'll get laughed out of court, but that's the argument Brady et al are making."
] |
High School student, how does college work? | [
"Major- Primary area of study. Often 40-60 credits taken in this area.\n\nMinor- You've taken enough credits to have an idea of the field, but did not heavily concentrate in it. Usually 18-24 core credits.\n\nTechnical School- Typically offers vocational and trade programs; mechanic, nurse, IT, etc\n\nAssociates - 2 years, Bachelors - 4 years, Masters - 2 years after your bachelors.\n\n Switching schools could be due to any number of reasons - they eventually got a scholarship to a different school, were accepted to a better school their sophomore year, were failing out of first school, etc.\n\nScholarships - talk to your school counselor. Make it a full time job applying for them your senior year of HS. It is more than possible to find enough grants and scholarships to cover your tuition, but it is often a time consuming process."
] |
When I'm passing urine, why does it froth some of the time but not others? This is into water without any cleaning products in it. | [
"The froth is from the amount of protein in your urine. The times you will most notice this is in the morning when the content is highest.",
"The timing of the froth will probably coincide with any meals you have eaten which are high in protein. Occasional froth in the urine is nothing unusual and nothing to worry about. You should seek help if the urine is constantly frothing, regardless of diet, as this could be a sign of kidney issues. If the kidneys do not filter out the protein, more will be present in the urine."
] |
why is math (statistics, calculus, etc) so important for a strong programmer? | [
"There are lots of areas of programming that require only basic math. If you're doing development for a moderate-sized web site or app, it's quite possible you'll almost never use any math, and never anything beyond things taught in high-school algebra.\n\nMore generally, some programmers use a lot of math all the time, some hardly use math at all.\n\nThere are many more specialized areas of programming that require a lot of math. Computer graphics uses a lot of trigonometry and calculus, so pretty much any game that requires physics or 3-d rendering uses a lot of math. Video and audio compression uses Fourier analysis. Cryptography uses number theory. Those are just a few examples - there are lots of specialties. Good programmers often need to have at least some familiarity with those areas, even if that isn't their area of expertise.\n\nQuite often large-scale software engineering requires more math - for example web sites that need to scale to millions of users. It's hard to properly optimize sites to handle a lot of traffic without a good foundation in probability and statistics.\n\nA degree in Computer Science typically covers many of those things, which is why there's a math requirement. In addition, Computer Science involves a lot of mathematical analysis of programs, including determining what's possible to compute, determining asymptotic runtime and memory usage, and mathematical proofs of bounds and of correctness.",
"Programming is - in a sense - just applied math.\n\nMath has a strong emphasis on:\n\n- logic\n\n- developing/applying algorithms\n\n- defining stuff (classes, groups, etc)\n\n\nI'm not saying you can't become a great programmer without studying maths, I'm just saying since they share so many similarities it usually helps to learn both or that it is easier for you to learn the other if you find you have a talent for one of them.",
"Both math and programming are strongly based in logic, so there is going to be a lot of skill overlap. Writing a program is often very similar to constructing a mathematical proof. You need to create steps that both logically flow together, and that are valid in the general case, not just in special cases. The skills behind math often apply to programming in a sort of a vague way. I might not ever need to find the integral for a hyperbolic trig function, but the mode of thinking that let me do that often also apply to math.\n\nComputers are often doing tasks that require higher level math to fully understand. If I am using a random number generator to perform a simulation, I had best understand probability and statistics to ensure the results are valid. I had also best have a little number theory so I understand how the RNG works. If I want to analyze how long that program will run for a given input and how much space it will require, that brings in abstract algebra, number theory, and calculus.\n\nAlso, computers are often used to directly solve math problems. If I need to invert a matrix or find an approximate solution to a complex equation, I need enough math to understand exactly what those things mean.\n\nFinally, you never know what math you are going to need, so it is good to have a big toolbox. I learned what a Poisson distribution was in college, thinking I would never use it. More than a decade later it was the key to diagnosing a serious network problem.",
"It's not really, for most types of programming.\n\n90% of programming tasks are writing (hopefully) straightforward logic, like,\n\n if user_clicked_resume_button(), then close_menu_and_resume_game()\n\nLogic like this is considered 'math' by mathematicians, but isn't normally what you and I would consider math (like calculus).\n\n**Statistics probably won't be useful** to a programmer unless that programmer is writing a program that must analyze a bunch of data - e.g. some research professor is doing a study which has a large amount of raw data, and she needs to draw conclusions by finding statistical patterns in the data - which the computer can be programmed to find (usually the programmer is just translating the professor's math formula into computer code, which often isn't too hard).\n\n**Calculus isn't useful** in everyday programming either, unless your program needs to do specifically do something with calculus - like calculate the volume of a 3D object. It's useful if you're doing very lowlevel graphics processing - or, say, writing a program to help students calculate a calculus equation.\n\n**Addition and subtraction are used** a lot in programming, but again, usually only when the program needs to tally something. (Low-level computer operations may require +-*/ operations to implement algorithms to find new memory locations from old ones, e.g. if making a custom data layout in C++ - but again, programmers are doing these explicit low-level manipulations with math less and less because all this stuff is already done in libraries they include.)\n\n**All kinds of math could be used in programming to _optimize_** the speed of your logic (algorithm) by doing fewer operations to achieve the same result - but if you really need that kind of optimization, you're probably going to get the algorithm from a textbook written by a really smart dude, like Knuth. Even if you're doing a math-intensive task, like graphics - in today's world, you're not likely going to implement the math part of a rotation, you're going to call the rotation() function in a well-tested library.\n\ntl;dr **Unless you're making software that is specifically made to do mathematics/simulations/data-analysis, then you're not going to need much math.** A programmer would need to know a lot about gardening if most computer programs were all about veggies.",
"So there's a lot of different kind of \"programmers.\" It's a big field. Some people focus on front-end development like making websites and interfaces.\n\nTurns out, a lot of UI programming is math-based. Animations or \"tweening\" (moving from A - > B) usually use basic quadratic, cubic, or sinusoidal equations to simulate speed. Anchoring parts of the UI so that the window reacts well when you change the screen size is another example that uses simple math principles to very complex effect. A lot of this kind of programming has been abstracted away, however.\n\nBut a more fundamental answer: computers, as we know them, are math machines themselves. You've probably heard that \"everything to a computer is 1's and 0's\" before, which is true. Everything you see and do _does_ eventually become a 1 or 0. This has implications for what we can do _with_ computers.\n\nAlan Turing famously came up with the concept of a Turing Machine, a theoretical contraption that can compute things for us. From there, we can reason why, for example, it's impossible to invent a \"perfect antivirus\" that can always detect whether a program is a virus or not. It also proves (mathematically) that we cannot generally analyze a program and say, \"will it terminate, or loop and freeze?\" (i.e., \"will this work?\").\n\nAnd on the back-end of things, you generally have to deal with data and things *at scale*. Let's say, for example, I have a system for storing and retrieving customer reviews. If I have only ~100 customers, I could probably save them however I like (maybe I stuff them all in a folder with the date as the file name). If I then need to find a specific review, I _could_ just open them all up one by one until I find the one I'm looking for.\n\nNow imagine if I'm storing millions or billions of reviews. Time complexity (how long does it take to do what I want?) and space complexity (how much _actual space_ do I require--RAM/Harddrive--to do what I want?) are fundamental concepts to understand for any modern computer scientist or programmer. Because small problems can suddenly balloon into very large ones if we're not careful.\n\nUnderstanding how complex these kinds of problems are directly relates to math. This gets into P and NP--namely whether something requires a polynomial- or nondeterministic polynomial-time algorithm to solve. But that's a much more detailed subject. Put another way: If you've heard of the [traveling salesperson problem](_URL_0_), we know from complexity theory that we can't build a program that will do the following: Given any graph (map), we can find the shortest path that will visit every node (location). It's just too complex and the problem becomes too large for larger inputs (i.e. big maps and many locations).\n\nOf course, if you use Google Maps, you're probably thinking that of course we can solve that problem, Google does it super effectively. Truth is, people come up with very clever algorithms that can very closely approximate answers to these problems.\n\nEDIT: **WHY THIS IS SO IMPORTANT FOR A STRONG PROGRAMMER:** A lot of these super high level and super low level concepts aren't used in all your programming. However, they inform a strong programmer's intuition, and they can be used to \"sniff out\" bad code and design. It's kind of like having a strong minimap and radar in a game: It might not tell you exactly what's out there and where to go, but it makes it damn easier to figure it out (and easier to correct course if needed).",
"Programming is a form of applied mathematics. A better understanding of the underpinnings can aid in their application.\n\nSet theory, group theory, and category theory are underpinnings of computer science, and many white papers on computation and computability are described in these terms. Mathematical analysis is used heavily to measure properties of programs, typically focusing around efficiency and complexity. Lambda calculus is a formal system that describes computation. There are many other branches and systems of math that can be used to describe different aspects of computation itself. It's not all just applied mathematics in terms of using X mathematics to solve a business problem. Knowing statistics, for example, would make a programmer very valuable at measuring performance, efficiency, and correctness of programs, and is typically an obtainable skillset to most developers.\n\nYou don't necessarily need explicit knowledge of maths to be a developer. Lord knows, I've worked with mouth breathers who managed to do enough to not get fired. Kudos to them. Also a consideration is there's plenty of software that can afford to be incredibly wasteful, which is actually most software.",
"Realistically speaking, most programmers never touch math except to increment counters. Maybe there's some basic addition/multiplication/division occasionally.\n\n\nTo take a step back, most computer programs consist of a series of steps that need to happen more or less in order. If you can't break things down into steps all the math in the world isn't going to help you program. That's probably where the \"strong at math\" part comes in, because that's an obvious indicator that someone is good at deconstructing a problem. There are other indicators of good programmers which aren't so obvious, like system-oriented thinking and algorithmic thinking. Those are a lot more difficult to describe and spot.\n\n\nIf you want a \"real\" programming skill, learn how to make a recipe then walk someone through it.",
"Because programming is math. It's the distillation of a real world process into a set and predictable series of steps, ie, an equation.",
"Programs use math, a lot. Sure, there is logic, if's and loop's, but most of the work in a program is math. Want to calculate the path of the first-person shooter - that's kinematics = matrix math. Want to recognize that product on the assembly line - that's machine vision = Hough matrices. Want to understand why it's hard to mine bitcoins, that's a cryptographic use of set theory."
] |
Why is diesel more expensive than gasoline? | [
"Diesel is used to power a large number of critical industries - trucking, farming, etc. Also, fuels very, very similar to diesel are used for heating in the winter and for lots of other purposes. So even though a minority of passenger cars burns diesel in the US, there's significant demand for diesel both year-round and seasonally.\n\nAlso, diesel is taxed differently than gasoline is. In the US, this leads to higher per-gallon costs at the pump (in some circumstances - around here, diesel is usually cheaper than gas). In at least some parts of Europe, diesel is taxed less than gasoline (\"petrol\") because it is perceived to pollute less per road mile, and thus is generally cheaper than gas.",
"You get less of it per barrel of oil. It's more dense (which is one of the reasons you get more mileage from diesel) and it's no longer true that it's a by-product of petrol production."
] |
Why are English words phonetically explained with strange symbols? Why not just include those symbols in the alphabet? | [
"First, they're not an English alphabet — each symbol in IPA is meant to represent a distinct and unambiguous sound that humans make to communicate. There are *some* sounds used by humans that aren't represented in IPA yet — so, it isn't complete. \n\nSecond: there are *hundreds* of symbols in IPA — far more than there are in any other phonetic alphabet. Memorising them all in order to cover cases that a student will never or rarely encounter, is pointless (even linguists don't memorise them all, that's why we have reference books).\n\nThere are actually different ways to pronounce \"Gabe\", depending on which accent the speaker has — the \"a\" varies, from long (amongst minnesotans and michiganders) to the rising-to-I tone of modern Southern United States speakers (represented in your example above) to a dropping tone amongst modern Germanic speakers.\n\nIPA allows for a written description of how a word is sounded, not of the meaning of the word.",
"If we wrote with the IPA, everyone would spell words differently depending on how you say them.",
"What you're looking at is the International Phonetic Alphabet.\n\nIts aim is to create a set of symbols that can be used to express any sound in any language on Earth. The way a word is spelled doesn't always indicate how it's pronounced (especially in English), but using the IPA can make sure there's no ambiguity.",
"That's the [International Phonetic Alphabet](_URL_0_). It's designed so that you can represent the sounds for any language without ambiguity. It's an entirely separate alphabet, not an extension of the English alphabet."
] |
why do I run out of gas faster when the a/c is on in my car | [
"Because you are using gas to power your car and power the motor on the air conditioner instead of just using gas to power your car."
] |
Common Ancestor theory. Does the thought that different early life forming on different parts of the planet seperate from the first organism completely disprove this theory, or is there evidence against multiple sources lineage? | [
"Evidence of parallel abiogenesis would damage the common ancesstor theory.\n\nThe *thought* doesn't prove or disprove anything.\n\nFossil record of life in multiple locations isn't necessarily evidence of parallel abiogenesis, as life can and does spread and become isolated.\n\nGenetic similarities provide evidence of common ancestor, even if parallel abiogenesis could be proven to have occurred, as it would simply mean the other lines died out.",
"If that did indeed happen, it would be clear from the DNA of any two organisms whether they have common ancestry. There would be almost no similarity in the genomes of two organisms with separate common ancestry.",
"On a cellular level, there are proteins and other organic molecules that are common to all known life forms. We can use subtle differences in those molecules to measure how closely related two lifeforms are. This provides pretty strong evidence for common descent.\n\nThat is not to say life arose independently from multiple locations. However, if it did, none of the lifeforms we are currently aware of descended from it."
] |
How birth defects happen | [
"There are many causes and many different situations.\n\nSome defects are chemically triggered, a perfectly normal fetus exposed to thalidomide at the wrong point in its development will turn out with a defect.\n\nSome defects are genetic, through a copying error or expression of a recessive trait a fetus will develop with a defect. \n\nThe concept of \"decide\" and \"happen\" carry the connotation of understanding and thoughtful decision making that doesn't make much sense in these biologic processes."
] |
Why did humans develop in Africa when there's so much more water/food in the Northern Hemisphere? | [
"Evolution needs some sort of selective pressure. Let me try to tone it down to ELI5: If food is plentiful, a species may not evolve. For example, bison have roamed the great plains of North America for thousands of years, and they have no reason to evolve any further (ignoring the problem of humans hunting them to near extinction).\n\nHere is the key: Africa was not always this dry. It used to be more of a paradise for primates. However, it gradually became drier and drier, and food gradually became harder to find. This is a perfect scenario for evolution to do its work. Our ancestors had to work harder and harder to find food over a long period of time. If you were smarter, you would survive long enough to have children. If you couldn't figure out how to communicate with others or how to fashion tools for hunting, your genes would die out. Thus, Africa was the perfect place for humans to evolve. \n\nOnce we were smart enough to live in Africa, we were smart enough to figure out how to leave Africa and find the bountiful paradises that awaited us.",
"There may be better resources, but I thought \"Guns, Germs, and Steel\" (_URL_0_) had a nice explanation about how civilization came about there. Also, understand that there was an enormous amount of human history (not recorded) prior to settling down and farming. Basically, the area around Persia had a lot of the best animals and plants that were/are capable of being domesticated.",
"If you have time i recommend the BBC documentary 'The Incredible Human Journey', it looks at mankind's evolution in Africa and then eventual migration all across the african continent and into Asia,Europe, N/S America etc. \n\nSomeone has split it into 5 parts and put them on youtube, part 1 can be found [Here](_URL_1_) (Apoligies for the unremovable subtitles but it was the best i could find at short notice)",
"You're implying that Evolution has a choice. Creatures in non-African territory didn't evolve supreme intelligence because therelittle need for them to, mutants with slightly higher intelligence had little to no boost of survival (obviously intelligence did grow but I'm talking in comparison with pre-humans). Whereas pre-humans did benefit from growing intelligence and so survived long enough - to present day in fact.\n\nYou can use your imagination to figure out as to why we benefited from intelligence; perhaps one mutant figured out a rock was harder than it's fist, did more damage and so that particular pre-human survived longer and had more offspring, resulting in a slightly more intelligent next generation, etc.\n\nMakes no difference as to where they evolved, it has nothing to do with food - actually, in fact a surplus of food may have even stalled or slowed down evolution as there is little competition. (Assuming your remark about the rest of the world being more nourishing is correct.)\n\nAlso, Neanderthals evolved in Europe and they were - arguably - more intelligent and even more aggressive than humans.\n\n\n(Don't grade me on my terminology or the slightly incorrect word, the theory is correct.)",
"A couple answers:\n\n1. Humans developed in Africa because that's where our ancestors lived. It's kind of tautological, but basically Africa is the place where a group of formerly-arboreal apes turned to living on the open ground in response to a former ecological niche dwindling, and we evolved from them. \n\n2. There's plenty of food in any hemisphere, but modern humans have often forgotten how to access it. Indigenous foraging cultures in various places still remember how, and have historically lived very well on it. \n\n3. Iraq used to be part of what was called the Fertile Crescent, an area of the Middle East that was especially rich and fertile. It's not like that anymore because climate change, a long history of intensive farming and in some cases because of ongoing, deliberate changes inflicted by warring early powers (salting the earth, for instance). Even then, it still has an agricultural sector -- it's not like farming is impossible there even today. Not all of it is desert. \n\n4. Agricultural civilizations develop where viable crops do. Subsaharan African civilizations have developed or adopted agriculture plenty of times too, they just use different crops.",
"Iraq's geographic features and climate have changed greatly over the past 10,000 years. It used to comprise the bulk of the [Fertile Crescent](_URL_2_).",
"you can check out the book \"guns, germs, and steel for more indepth information on this subject.",
"ELY5? Because we just happened to start there.\n\nWe then moved because it was not very good.",
"I could of sworn Iraq, specifically the Babylon area was lush with vegetation."
] |
why do some sites have highly annoying add's to hinder your experience, do these sites or people that make the adds honestly believe that annoying people will increase the chances of that product being bought? | [
"Most of these ads are not actually for the websites you see them on. The web sites displaying the ads don't really care if you buy the products being advertised. They get paid for the number of times the ad is viewed and/or the number of times someone clicks on the ad.",
"There are a number of factors to these annoying ads. \n\n1. Big over the top ads cost more to make so more profit to be had. \n2. Clients demand innovation in advertising unfortunately that usually entails annoying the hell out of the savvy internet user. \n3. The word disruption, it is a misguided and foolish term banded around by advertisers and agencies and they believe if they interrupt your journey with something big and flash you will interact. \n\nMy opinion however is if people don't interact with them they will die out, if people do then they stay. Blame your fellow web user for keeping these things going!",
"Ads don't have to appeal to the general population. They only need to appeal to the segment of the population too dumb to block them. Dumb people are harder to annoy."
] |
Can animals commit suicide ? | [
"I've heard of two cases where they have. One was a [dolphin](_URL_1_), which stopped breathing intentionally. \n\nThe other was a bear that was having its bile drained for some eastern medicine thing. Not just once, that was basically the bear's life, being a perpetually wounded source. One day, she killed her cub, then slammed her head into the bars of her cage until she died. \n\nShe's not the only one, and that's not the only [method of choice](_URL_0_)...\n\n(Note that I'm not counting certain defense mechanisms, like exploding ants or some bees that die when they sting, as suicide per se.)",
"Yep. I worked in a pet store that sold birds. We had to inform the customers that certain types of birds like to be in pairs, not even necessarily sexually. If that person were to only get one bird, the bird would likely bond with its owner. If they were to get two birds, they become incredibly attached like little best friends.\n\nHowever, if one of the birds were to die, they were known not only to commit suicide by refusing to eat or drink, but they would even self-harm by using their beaks to pluck out their own feathers and leave little bites all over themselves.",
"I believe that monkeys that were kept in rape chambers, as well as their young (who were kept alone in dark rooms for their entire lives) were suicidal.\nWiki:\n_URL_4_\n\n[P.S. The government is happy to fund models of depression, bipolarism, autism, and psychosis. But they really if ever fund research into models of ecstasy, compassion, and creativity.]\n\nCybernetically controlled cockroaches, if used too heavily frequently act in seemingly suicidal ways—for instance running toward lighted areas rather than dark areas. But we can't know if this is suicide, or just brain damage. Examples:\n_URL_3_\n_URL_4_",
"Heard of it where horses were being worked to death opening up the Alaska gold fields, just walked off of cliffs once in a while.",
"I read something on reddit about a mother bear killing her cub then killing herself \n_URL_5_",
"My partner and I used to work on a dairy farm. One night, we assisted a cow with her birth because the calf was stuck. Unfortunately, it took too long and the calf died before we could pull it out. The next day, we found her. She put her head between the gates and laid down. She strangled herself to death.",
"Of course. Hymenoptera insects (bees and certain ants) commit suicide to save other members of the hive/ant hill.",
"When I was eight my parakeet tried to get out like every day and one day he just flew too hard into the cage wall and died :(",
"There is a bridge called the Overtoun Bridge where it is estimated that over 600 dogs have committed \"suicide\". Some researchers however believe that it could have something to do with minks that live under the bridge. This however does not fully explain the dogs who leapt of the bridge, survived, crawled up again and leapt again to their death.\nsource: _URL_6_ #5 the Overtoun bridge (there are many other articles in this as well)\nedit: spelling",
"I've heard that a scorpion, when surrounded by fire with no clear path if escape, will inject itself with its own stinger. Not sure if that's the same as suicide over a lost offspring, but it shows despair and a fear of pain. And in an animal with no brain"
] |
What is happening when my desktop tower is making (assumedly) calculating noises? | [
"If you can hear calculating noises from your CPU, that's mighty fine hearing you have. The noise is most likely from your hard drive, moving the read/write heads back and forth on the platter.",
"Stop right now and make sure that your data backups are current.\n\nThose aren't \"calculating\" noises. That's probably your hard drive. Any unusual noise coming from your hard drive may be a prelude to drive failure.\n\nIf these noises are normal for your drive, then you should still have backups. Trust me on this one."
] |
American Curfew Laws, What Are They? | [
"Yeah, it is. It happened to me once. From what I can tell, how seriously they take this law depends on the area. For instance I used to live ain a very safe suburb, so I'd go walking at night as a kid, and nobody cared. But when I moved to a dense area with more crime and went out, I got the curfew violation.\n\nA second form of curfew law is daytime curfew. This is when you get caught being out durign the day, when you should be in school. This is considered a much more serious violation than a nighttime curfew, for obvious reasons.\n\nAs for why during the night? A lot of reasons. High crime in an area would result in it, either to attempt to stop kids from committing crimes, or to protect them from those who do commit crimes.",
"Depends on where you live and the circumstances.\n\nSome places have no laws about when you can be out. Some places have laws saying that people under 18 can't be out after X O'clock. Some places have laws saying that you can't be out on foot after X O'clock.",
"It depends in where you live, there is a legal curfew for minors in a lot of places, but unless you're super young I don't think cops would bother if you aren't being suspicious"
] |
Why can the brain recall trivial things it was exposed to once, but when intentionally trying to learn something, requires repeat exposure and concentrated effort? | [
"It all has to do with novelty and priority. If someone says something strange, it piques your curiosity and doesn't require much effort to retain. It can potentially also threaten your existence much more than can, say, memorizing chords on the guitar. And learning a skill, you're blatantly aware of the insignificance of each little step and don't treat it with the same level of importance. It'd be \"learning the guitar\" that's important, not doing fingering exercises and learning sheet music, which are viewed more as obstacles to the entire skill itself. Its much easier when you regard each step as if it were the only thing you were trying to accomplish.",
"You don't find it easier to memorize trivial things. You merely encounter a whole, whole lot more trivial things and some tiny number of them stick. Meanwhile to learn something you need to remember *all* the facts presented, which is going to take effort.\n\n If learning something well only required you to remember 1/100 of the facts presented it would be much easier.\n\nSo you encounter a million trivial details a day and only remember one in a million of them it's going to seem like you can recall more trivial things than you can learn deeply.",
"A few preliminary points.\n\nFirst, it's important to recognize that we only have the faintest idea how the brain actually *works* on more that a very zoomed-out, macro-level basis. Sure, we can say \"This part of the brain appears active when a person is exposed to this stimulus,\" what that brain activity is actually *doing* is almost entirely a black box. We know *that* the brain does things, but have almost no idea *how* it does them.\n\nSecond, it's also important to recognize that there are different *kinds* of learning, and they appear to occur in *very* different ways. So, for instance, \"learning\" that 2 + 2 = 4, is different from \"learning\" that you like the taste of strawberries, is different from \"learning\" how to ride a bike, is different from \"learning\" what someone said to you just now. \n\nOkay. On to your question.\n\nPart of the reason \"trivial things\" are easier to recall, even a very long time after they occur, is that, being trivial, there's not all that much to those memories. Let's compare apples to apples here so as to eliminate the variability discussed in point two above. It's just going to be easier to memorize a single haiku than it will be to memorize Shakespeare's *Hamlet*, because the latter involves orders of magnitude more information than the former. I should think this would be intuitively obvious, so I'll move on.\n\nAnother part actually has to do with the variability discussed in point two above. What someone said to you that one time involves different kinds of attention and different sensory inputs than any deliberate attempt to acquire and retain information. The brain perceives 100% of the things you experience in a given day, but it automatically disregards the majority of that right off the bat (e.g., you tune out repetitive sounds, don't take conscious note of most of the things in your visual field, etc.). But for whatever reason, some things will catch your attention, and these are often translated into long-term memory whether you want them to be or not. But that kind of reflexive \"learning\" is very different from *deliberate* learning, or, at the very least, whether the brain \"invokes\" its routines for \"storing\" a particular experience or bit of data in the long term is not entirely up to you. There are certain techniques which can convince the brain to do that, but whatever neurological process area involved are not subject to conscious control. \n\nBut along with that, there are other kinds of \"learning\", particularly the acquisition of [procedural memory](_URL_0_) that operate *below* the level of conscious thought. How to walk. Ride a bike. Touch-type. Sign your name. These are *skills*, and they're a very, very different kind of \"memory\" than bits of information, whether experiences or abstract data, and they appear to be only acquirable by practice and repetition.",
"Basically brain receives information through our five senses and they are processes at different areas if brain (hippocampus, cerebellum), the things you consider trivial must have some of trigger to it like if you hit the switch it lights up,the trigger can be anything and like memorizing something and forgetting it while we require most is a common phenomenon ,brain is like a library and if we are not using a particular memory over a time it is overwritten by a new memory, similar to computer allocating address.",
"Memory doesn't work like a computer, despite everyone always telling you the human mind is like a computer. It really isn't. The subconscious mind, which we have no conscious control over, is the big player in the mind. It chooses, for the most part, what we remember. What we like. Who we hate. It drives our cars for us most of the time. And it is involved in learning as well. In fact, its been proven you can learn without the conscious mind being involved at all."
] |
When a stock price drops fast in a short amount of time, who are the stockholders selling to? | [
"There is always people willing to buy stocks at low prices: for example with a stock at $80. You would have:\n\nI'll buy 200 stocks for $77 ea\n\nI'll buy 100 stocks for $76 ea\n\nI'll buy 400 stocks for $75 ea\n\nI'll buy 200 stocks for $74 ea\n\nI'll buy 300 stocks for $73 ea\n\n...\n\nI'll buy 300 stocks for $53 ea\n\nSo when you really want to sell, you can take lower than the market price which pushes the price down."
] |
if a communist country has a centrally planned economy, how is a country with a central bank that sets interest rates not communist? | [
"Communist states typically disavow any notion of personal property either partially or totally. They call for a wide range of state action, covering every industry and business and so on. So they represent an extreme end of a spectrum. The other end might be the free market, or perhaps perfect anarchy (which is what true Communism ought to be: there need be no intervention, because individuals would do it themselves) where the Fed did nothing. However the Western world is at different points far away from Communism. Centralised interest rates are an attempt to intervene in the free market but they don't go far enough to make a state Communist. Similarly nationalised school system for example would, nor the sort of tax/spend common to Western nations. All these things which states do are market interventions."
] |
Why is the US president elected to a 4 year term, but members of the senate get unlimited 6 year terms? | [
"It is worth pointing out that the 2-4-6 year term system (House of Representatives, President, Senators) was put in place to prevent what the Founding Fathers feared most: tyranny. On any given election cycle, only 1/3 of the Senate is up for re-election so that one botched/rigged election cannot completely take over the Senate.\n\nRotating congress(wo)men and presidents in and out in different intervals assured relatively smooth transitions of power and guarded against radical change in direction of the country.\n\nPresidential term limit is a new thing. Basically: politicians got scared when FDR was elected to four consecutive terms.",
"I think the original idea was that representatives served two years so they would always have to stay 'in touch' with the people they represented, while senators served longer terms so they would be able to 'vote their conscience'. The founding fathers clearly didn't predict career politicians owned by lobbyists.",
"One reason is that the constitution wasn't set up to limit presidential terms. The major reason George Washington was such an important president was that he was the first and set so many precedents which basically dictated what his successors would do. \n\nWashington decided after two terms not to run again and most other presidents followed suit until FDR. \n\nAfter FDR in the late 40's, there was a republican resurgence, and the republican congress led the charge of limiting presidential terms to two with the exception of presidents who take office mid way through their first term (so LBJ for example could have run for president in 1968 if he had wanted, had his popularity not dipped so far and if not for major health issues). \n\nNo such rule was ever made for congressional terms and it simply never became the norm in American politics. \n\nI feel that one of the biggest problems with congress is that so much is dependent on seniority. Long standing Congressmen get more prestigious and important committee seats making them more powerful the longer they serve. \n\nOne expert move during LBJs long senate career while he was majority leader was increasing the number of seats on various senate committees making him able to make more appointments and therefore increase his political power by having more congressmen indebted to him for favors. \n\nHe still remains the singe most effective legislator in American history (with the exception of maybe a couple of those that lead the charge for the Declaration of Independence in '76). Such is the nature of democratic government.\n\nYou always hear people use the line *\"All Americans Hate Congress but They Love Their Congressmen\"*. \n\nThis is a lame, cop out argument that simply hasn't been used enough to become cliche and redundant yet. \n\nThe real reason is that, for example, Arizona would be very foolish to trade longstanding, high ranking John McCain (chairman of the armed forces committee) for a freshman senator no matter how great his genius or moral standing. \n\nA freshman senator could never aspire to the level of power and influence John McCain now has; power that could be used to help the Arizona district he represents. \n\nI don't personally actually have a problem with McCain, he simply was the first lognstanding senator to come to mind. Notice how Massachusetts didn't give up Ted Kennedy's senate seat to Republicans until the guy died. \n\nI'm not saying thats the only reason or even the main reason Ted Kennedy held office for so long. But for instance if its 2008, amid a financial crisis, you would have to be pretty dumb to dump the guy who's been in office since 1962 and continues to have all the money and prestige of the Kennedy name (and Kennedys seat wasn't even up for re-election in '08) . \n\nWhen Obama passed his stimulus bill in '08, it was only with huge concessions to Republicans and although it was successful, from an economic standpoint (if not really a political one too) it could have been far more effective. All this occurred while Democrats had a 2 house majority. I've never heard it mentioned on reddit before, but the fact that our young president only had 3 years logged in the Senate definitely had a major impact.\n\nPeople are always so eager and ready to talk about borderline corruption and even alleged laziness in congress. Nobody ever points out that our legislative branch is run like a frat-house.",
"I believe part of the idea (among others that have been stated) was because the different focuses of each group. The House was intended to focus on the more pressing, immediate interests of the country, while the Senate with longer terms were free to ensure legislation was the best for the country in the long term. Presidents served 4 years essentially to bridge the gap between the two."
] |
how does nonsurgical cool sculpting work to reduce fat? | [
"Basically they freeze your fat cells to death, nothing really more complicated than that. The dead cells are then absorbed by your body. Viola, less fat. \n\nCalling it \"nonsurgical\" I think is a bit of a stretch. \"Non-invasive\" certainly, but it is an hour long medical procedure during which a local anesthetic is necessary. \n\nIt's technical name is Cryolipolysis (literally frozen fat cell destruction); you can read more about it on the [wikipedia page](_URL_0_) if you're interested."
] |
apparently you cant die from holding your breath, explain | [
"If you're able to hold your breath long enough, you pass out and then involuntary breathing begins.",
"You have very, very strong instincts that won't let you do it usually. You'll give up in your panic and catch a breath.\n\nEven if you don't you'll pass out, and immediately start breathing again.\n\nYou need a plastic bag or something to prevent your body getting air after the passed-out phase. (Of course there's a good chance you'll panic and rip open the bag while you're nearly passing out, but don't count on that.)",
"You breath without thinking, but you have to consciously hold your breath. So if you hold your breath to the point of passing out (difficult), as soon as you lose consciousness your subconscious brain will start breathing again. You would need a way to hold your breath to the point of passing out... and then for a few additional minutes while your brain dies.",
"There is a part of your brain called the medulla oblongata. This part of the body controls your breathing and involuntary things like sneezing and coughing. Short of disrupting this you'll pass out and the medulla will take over and get your breathing again."
] |
Why do my eyes hurt after looking at a screen too long? | [
"This is due to how the human eye focuses. It doesn't work like a camera wich gets set to a focus distance and then stays there. Breaking it down to eli5 level: If the responsible muscles rest, your focus is on the *very distant* setting. Looking at very close things is muscle exercise, and while your eye muscles can pretty much work constantly (in contrast to your leg muscles for example), the can't, just like other muscles can not, maintain a specific position for very long without hurting."
] |
Why can't people drink the water in Mexico but fruit that was grown in Mexico and watered with non filtered water is ok to eat? | [
"The water is a problem because of bacteria. Bacteria will not survive being absorbed by the roots of a plant and turned into fruit. Water sprayed on the surface of fruit could potentially be a problem, but the bacteria that live in water wouldn't survive long out in the air and sun."
] |
Why do you get so hungry when you are high? | [
"In your body you have an Endocannabinoid system which has a role in appetite, pain-sensation, mood, and memory. \n\nIt's suggested that THC the psycoactive compound in cannabis activates a receptor called CB1 which directly increases appetite when fired.",
"So, what happens if you never feel that way? I have never once gotten the munchies.",
"Disclaimer: not trying to say everyone and the science behind it is invalid, just sharing experience.\nI am not particularly hungry when high, but it makes food taste so much richer to high-me. I'm not even remotely hungry most times, I just know from experience that food tastes amazing during the time so I take full advantage of it.",
"Also, marijuana keeps you from feeling full. So your body continues to have cravings for food long after food enters your stomach.\n\nAnother thing is that a lot of 'stoner snacks' are chalked full of MSG, which makes you hungry."
] |
what happens to credit card debt when people die? | [
"The balance will be taken from the estate of the deceased. If the estate does not have enough to cover the balance, the debt is written off as a loss. I have heard anecdotes of debt collectors chasing after descendants for the debt, but unless they have signed as legally obligated to paying it, there is no legal standing for them to repay it.",
"The same process that happens with all debt:\n\n* The current debt holder investigates ability to get debt paid (estate in the event of a death).\n* Depending on difficulty of getting payment, either get payment, settle for reduced payment, \"sell\" the debt to another agency, or swallow the debt and move on.",
"The deceased's estate assets are to be used to settle any debt.\n\nIf the estate assets run out before debt is paid off, the debt is abolished.\n\nNEVER ARE THE FAMILY MEMBERS RESPONSIBLE FOR LEFT OVER DEBT! Many debtors will attempt to collect from family members, but this is illegal."
] |
How can math equations be depicted through stories such as Alice's Adventures in Wonderland? | [
"The book AFAIK doesn't really depict math equations, but general mathematical ideas. \n\nFor example, the Cheshire cat disappears, leaving only its grin. This is analogous to the type of abstraction that often occurs in mathematics; one will take a familiar concept, like integers, and then forget about everything that makes it what it is, except for some mundane detail, like the distributive law. \n\nSee some examples in the symbolism section [here](_URL_0_).\n\nFor some reason, Charles Dodgson (Lewis Carroll) disliked this level of abstraction, and so put symbolism in the book to show how ridiculous it all was. \n\nBut mathematicians don't care if something is ridiculous or not, only if it can be proven. So nowadays, we use far more \"ridiculous\" and abstract concepts all the time. Most mathematicians I know actually have trouble doing things like regular addition or multiplication, because such a skill is almost entirely irrelevant to being a good mathematician."
] |
If we have never seen or been to the planet's core. How do we know what it looks like or how it works? | [
"We used a lot different methods. The waves of the earthquakes act differently when moving through different materials. Measuring large earthquakes allowed us to get a good idea of what was going on in the earth just passed the mantle. The rest was speculation constructed from what we knew of the outer layers of the earths core and from the fact that we have a magnetic field means, that our core has to be solid iron turning in liquid iron. By the power of earths magnetic field we can get a relative idea of the size and concentration of the core and from the local asteroids and judging by what should have been available around the time earth was formed, we could conclude as to what it's composition should be. There is more, but that should give you an idea of how we can figure stuff out without needing to actually see it.",
"We know common elements in the universe, we know some basic properties of elements such as denser elements sinking below less dense ones and the strength of the earth's magnetic field which suggests a certain amount of conductive material in the core behaving in certain ways. We also know the mass of the earth based on its gravity and can therefore deduce the average mass of what it is made of.\n\nOther information comes from seismology. We know whether parts of the core are solid or liquid based on the time it takes for an earthquake to register on other parts of the planet because the waves of the quake will travel at different speeds through different mediums.\n\nI'm sure I haven't covered every example but the core has a large effect on a lot of very measurable things and a lot can be deduced from that."
] |
What is this CE symbol I'm seeing on everything? | [
"In addition to what /u/StrangelyTyped and /u/energymisdirected said, it's important to note there is another almost identical CE symbol that does not mean the product meets European regulatory compliance.\n\nSome Chinese manufacturers allegedly print a very similar CE logo on their products that is supposed to indicate the product is a \"China Export\" but in reality the mark is just intended to confuse consumers (and officials) and make them believe the product has the proper European Conformity certifications.\n\nTake a look at the (small) difference between the two logos: _URL_0_",
"The [CE Marking](_URL_1_) is an indication that the product was designed to meet all necessary regulations and laws for sale in Europe. As the Wiki article says it is an \"abbreviation of Conformité Européenne, meaning European Conformity\""
] |
While watching late-night TV, I see ads for buying gold and silver. Why should/shouldn't I do that? What's the deal? | [
"Generally, commodities like gold and silver can be a less volatile market than stocks or currency.\n\nHowever, most of these commercials are scams. Especially for buying coins. The amount of gold they have in them is tiny. like less than $1 worth of gold in a coin that costs $20.",
"If it's on TV, that usually means the price either includes (if you're buying) or is reduced by (if you're selling) the price of the ads which can be high. \n\nLate night ads for companies that buy gold tend to have relatively high refining costs, and to get the offer one must usually send their precious metals in which gives the buyers a substantial [negotiating advantage](_URL_0_). \n\nLate night ads to sell you gold tend to sell noncollectable gold objects at a very substantial collectors premium. Be very cautious of plated objects (which are mostly base metal with just a thin gold or silver layer). \n\nIf you are interested in acquiring or collecting precious metals, you would be wise to buy noncollectable metals for as close to melt or bullion value as possible or learning a lot about the collectible objects you want to start collecting.",
"When you buy jewellery, a big part of the price tag is comes from things like craftsmanship and upcharges from the manufacturer, distributor and retailer along with the raw cost of the metals. With coins, things like condition and rarity come into play.\n\nThe cash 4 gold guys don't care if grandma's brooch was made in 1893 by the most prestigious jeweler in Europe. They only care that there's $30 worth of gold to melt out of it, so they'll give you $10 if you're lucky.\n\nIf you've got old jewellery or coins to sell take them somewhere like a pawn or coin shop to find out what you can get for them and try to do better yourself on craigslist or ebay."
] |
Character and letter Alphabets. | [
"You're making a distinction where there is none. \"Character\" and \"letter\" are pretty much synonymous. \"A\" is a character just as much as \"字\" is a letter. They just represent different things.\n\nIt's necessary though to distinguish between different forms of writing. You have…\n\n- **Alphabets**, which basically treat consonants and vowels as equal.\n- **Abjads**, which don't write vowels at all, instead leaving them implied to the reader.\n- **Abugidas**, which write vowels as modifications on consonants, such as with diacritics.\n- **Syllabaries**, which give one unique letter for each possible syllable.\n- **Logographies**, which give one letter for each word or morpheme (sub-word)\n\nThough, note that most writing systems contain a few features from every type of script. English isn't purely phonetic; sometimes vowel letters, instead of having a pronunciation of their own, are used to change a consonant's pronunciation (like \"e\" in \"nice\" vs. \"panic\"). Similarly, the Chinese script has a lot of phonetic features — not every word is just a doodle of the word it represents. A word like 鯨 \"whale\", when broken down is formed from 魚 \"fish\" (shh, the characters were made a long time ago) and 京 \"capital\", but 京 is just being used phonetically, since 京 and 鯨 both are pronounced _jīng_. It's basically \"the fish that sounds like 京\", not \"the fish that has something to do with capitals\".\n\nSo then, to answer your question as to why languages in one place tend to prefer one system instead of just using whatever, it's simply due to how writing spreaded. The Roman alphabet wasn't invented by all the languages that use it, it was invented by the Romans. From there, it spread to other languages that didn't have writing yet and thought it would be useful. In most cases they just ended up taking the same writing system, though of course there are examples of languages choosing to develop their own, such as Korean and Cherokee."
] |
How does a can of whipped cream work? | [
"Liquid cream is held in the can along with nitrous oxide, under pressure. This pressure keeps the nitrous oxide liquid too.\n\nWhen you press the nozzle, it releases the pressure. This causes the nitrous oxide to boil - turn into a gas - which has the dual effect of both aerating the cream and pushing it out of the can.\n\nThis is why the can gets cold (as with all aerosols) - when the pressure drops, the temperature drops.",
"Like a can of spray paint but more sugar.\n\nIt's filled with sweet, sweet confection, and then pressurized, typically with Nitrous Oxide. This pressure, when released by pressing the nozzle, pushes out the cream."
] |
How do we take photos of the universe that aren't from Earth's perspective | [
"The photos either are taken from our perspective or are artist renderings based on data we've collected."
] |
How does lithium control the moods of a bipolar person? | [
"Bipolar is where ones dopamine receptors (pleasure center of the brain) go up and down irregularly, where a normal person's brain their dopamine receptors go up or down based on stimulation from the outside world. Like, listening to a catchy toon or wanting to dance can be considered addictive because it increases the dopamine in the brain.\n\nLithium regulates the pathways for dopamine to flow through the brain. This removes excitement as it lowers the dopamine use in the brain.\n\nA fun little correlation is how bi polar is similar to an opposite of ADD. In ADD one does not get enough pleasure center response to the brain to be able to concentrate on one subject easily, while bipolar will often the exact opposite.\n\nWhile ADD can be helped by adding some fun non distracting music to the background while working, I speculate if the manic depressive person meditated regularly (a specific type of meditation) it would neutralize them much like lithium does, if not even better. Note: I have not seen studies regarding this. I am speculating.",
"_URL_0_\n\nLY5: It disrupts the chemicals in your brain that make you bipolar.\n\n(Yeah, I know, that \"explanation\" makes me [President of the Tautology Club.](_URL_1_) \"It works because it works.\" Sure, right.)"
] |
How does exercise benefit a human physiologically? | [
"A lot of hormonal stuff happens that I don't know enough about to explain, but basically, you damage your body and your body goes \"well shit, I gotta be stronger if this is gonna keep happening.\" \n\nSo then it gets stronger. \n\nNote that if you do the same exercises forever, you won't keep getting stronger, you'll just maintain that level of strength... Your body is already used to it.\n\n\nIf you DON'T exercise, your body goes \"Oh I don't need all this muscle anymore, I can get weaker!\" And you get weaker.",
"If you exercise you body's muscles systematically, in a measured and controlled fashion, they become stronger, quicker and develop greater endurance. That muscular \"stress\" causes the heart and lungs to respond appropriately to support your entire system of muscles and major organs. \nPeople talk about scenarios where you may have to make a \"fight or flight\" decision, almost instantly - a body that has been systematically stressed is in a much better position to do either, successfully.\nIn my competitive years, when I was exercising most strenuously, I never experienced \"an uncomfortable burning sensation\", but I did feel a comfortable warming of the specific muscles being worked. After a strenuous workout, a warm, not hot, shower left me very comfortable and relaxed. Frankly, I've never felt better since! If you do consistently feel that sort of discomfort, you should probably explain the conditions to your doctor and see if possibly there is something wrong.",
"Creating micro-tears in the muscle is one of the key components of muscle growth. The body produces more muscle fibres to fill the 'tiny holes' created by the tears.",
"Your body requires energy to operate and building blocks to maintain. Your body hates wasting energy and muscle mass costs a lot of energy to maintain.\n\nThat means if you never exercise. Ie. if you never engage in any physically strenuous activity, your body will maintain the minimal amount of muscle mass you need to do what you usually do. If you were to become bedridden or wheelchair bound for a long period, your muscle mass might even waste away to the point where you're weak or too weak to walk.\n\nIf you do engage in strenuous activity that exceeds what your body can comfortably manage. It will start using up resources to build more muscle mass. This is the tearing process you mention. Essentially if your muscles are not up to the job you put them to, they will damage. Since damaged muscles are bad, your body will increase muscle mass in order for you to be able to handle your lifestyle.\n\nExercise regimes are really nothing more than controlled methods of constantly increasing the strain on your body so your body will keep adding muscle mass. Provided your nutrition is sufficient.\n\nIn terms of health advantages you're also working on your bone density, lung capacity, flexibility and let's not forget that your heart is also a muscle. A good strong heart is always a good thing.",
"The faster and further you can run from immediate danger, the longer you will live. Biologically."
] |
Why is an introductory class to something referred to as '101'? | [
"Because in American colleges, every course is given a 3 digit number. The first digit represents the year that most students are expected to take the course. Most of the first classes an American college student will encounter is Whatever 101.",
"It comes from one method of numbering courses in college. Typically, the first digit refers to the level of the course, i.e., 1xx are the freshman courses, 2xx are the sophomore courses, etc. The last two digits are assigned to each course of that level, with higher-numbered courses usually requiring some lower-numbered courses as prerequisites. This means the lower-numbered courses tend to be introductory or survey courses, and the lowest-numbered courses tend to be the most basic to understanding the subject area. Thus, your first, broad encounter with a subject will typically have a class number like 101."
] |
Why are gas prices so high even though the US is producing the most it has in over two decades? | [
"That's a loaded question, but on an ELI5 level:\n\nHigher domestic production is just one small piece of the supply and demand curves that dictate gas pricing. Other factors, particularly supply of imported crude (which accounts for a very large percentage - 40-70% depeneding on who you want to cite - of petroleum product in the US), rapidly increasing global demand and a complicated regulatory system all contribute to pump (ha!) the price higher. \n\nAlso worth noting that gas in the US is still cheaper by volume than most of the world.",
"Do you guys in USA have a huge tax on your fuel?\n\nIn the UK, fuel is taxed. Over 50% of its pre-vat value is \"Fuel Duty\" then VAT is added. So the cost of fuel to make & sell is around 50p per litre. Add on another 58p for fuel duty.. then another 20% for VAT (about 22p) and fuel ends up being somewhere around £1.40 per litre (unleaded 95) once you add retail profit. Way more than you guys have to pay.\n\nI found a cool graphic which breaks it down:\n_URL_0_\n\nI don't know why we put up with shit like this over here. It is called a \"stealth tax\" in the media. It is done on other products too. (cigarettes, alcohol etc). You don't see it broken down on any sales receipts, it is just given as the cost of the product.\nWe also pay a road tax which is a fixed fee to keep our cars on the road. It is illegal to drive around without it.",
"First of all, I'm not an authoritative source. Even if there is gas in the ground, it has a certain cost to get to it, it has all kinds of economic and geological reasons. So let's say that gas costs 5 in the world market. You have some gas, but the geological situation is so bad that if you tried to produce that, it would cost 6. Noone would buy that, so you wait and leave it there. As there are less gas sources in the world, the price will start to rise. Let's say it gets to 6. So now you start producing your own gas because it just became profitable for you. It will not decrease the price, because that wasn't profitable before. But it will help sustain the price, until the new sources run out as well.",
"I too would like to know why prices are still high. And why hasn't the prices gone down but instead gone up. Someone has to be raking up big amounts of capital"
] |
Why does corporate technology seem to cost way more than the consumer equivalent? | [
"If you kept your data on a single $75 SATA drive, don't be surprised if it just disappears one day due to a crash.\n\nEnterprise level storage arrays are much more expensive. That $23,000 is likely for solid state storage (aka flash) and not SATA. It's in an array that is fault tolerant and probably has software to create things like snapshots, clones, and backups, and it generally needs to fit the needs of the rest of your company's data. Having a special solution just for you that doesn't fit other applications' requirements is a nightmare to maintain if everyone does that.\n\nIf you look up storage arrays that are just disk and don't have all those bells and whistles (in the IT world, we call that JBOD - jaybod, or Just a Bunch Of Disk), and you will be paying much much less per TB. You could probably get well over 200 TB for that $23,000 price tag. It will have fault tolerance, but probably no way to do snaps, clones, or replication.",
"The single biggest reason is that places that sell to businesses or businessmen nearly always charge a premium. Just look at business class vs. economy flights, and business traveler vs. casual traveler hotels. Business people are very price inelastic and are often sheltered from the full cost by tax breaks or company compensation.\n\nThe second is that consumer sales offer minimal pre- or post-sale support. You buy the disc from NewEgg and you've got to handle every step of it from research to installation to maintenance, and if it fails NewEgg is going to give you a \"sucks to be you\" letter and maybe a refund.\n\nThe last is related to that, if they are selling you a product or a service and something goes wrong, they are charging for the potential liability. If Best Buy's installers accidentally goof up on a person's home computer, they are likely out a few family photos. If this company brings down the servers of a major financial firm, the damages can run into the millions.",
"Some times, it's because the business grade equipment is actually better. Not necessarily better at what it does (most drives of identical size and, connector type, and RPM will have the same performance) but because it's manufactured to higher tolerances or more rigorous levels of testing are performed before being approved for sale.\n\nAlso, TS might be including costs to have someone do the install or upgrades to hardware necessary to fit the new drive if there is not a free bay (also, you said that it's corporate, right? It's entirely likely they are using SAS instead of SATA, which generally is more expensive in my experience)\n\nThe other things about businesses being charged a premium, as others have mentioned, are definitely big cost drivers too, though.",
"23,000 is crazy even for enterprise. It will definitely cost more than standard equipment The extra costs are due it increased expected reliability. But you can just purchase a new corporate server off newegg at a reasonable price. It's possible you or they misunderstood something, 1TB is a small amount of data.\nHeres a lenovo 4x1TB Server, for $2400. Since there are more than one 1tb drives they can be setup in a raid configuration for added speed and or drive failure redundency.\n_URL_0_",
"Industrial grade equipment is sold at its premium to those who want/need/afford it\n\n$60 plastic coffee maker at wall-mart \n\n\nvs \n\n\ncommercial grade stainless steel station that runs 8 hours a day for $500"
] |
How does a Transistor work and why is it so important? | [
"I'll tackle the \"why first\". So, a computer needs to be able to take input and give you output. Whether that's deciding what is 2+2 or what it should display on screen. Thus, we need a device that translates input to output *automatically* using electricity.\n\nI'll use a MOSFET transistor as an example, as it is arguably the simplest. There is voltage at one end (power) and ground at the other (somewhere for power to go), but the current flow is blocked by the magic of \"chemistry\". There is an input node *next to* the path we just discussed. It isn't on the path, it's just reeeaally close by, separated by a small space. When you give that node a positive voltage (input), the pathway unlocks, and the current can flow from the high voltage to ground. \n\nNow, how do we use this awesome little device? Well, you can take a little wire of copper and connect it to the pathway from before just a little bit above the ground node, and run it to a dead end at the input node of a different transistor. This means your first transistor's output will determine the next transistors input. You have now created a digital IF...THEN condition. \"If this happens, then that happens.\"\n\nInstead of connecting the bottom of a transistor to ground, you can connect it to the \"power\" node of a different transistor, such that the 2nd is inactive until you give input to the 1st one. Now you have 2 switches that interact with each other based on two sets of input.\n\nMix and match these combos of transistors and you can build \"logic gates\". AND, OR, NAND, NOR, XOR, XNOR. These transistor networks give a single output based on the combinations of 2+ input.\n\nAND: If Bob and Terry want to get dinner, then you will go with them. But if only 1 of them (or neither) wants to go, you won't bother.\n\nOR: If either, or both, of Bob and Terry want dinner, you will go. You just don't want to go alone.\n\nThese logic gates can then be wired together to make more complex things like number adders and decision trees. At that point, you can now control numbers and IF, THEN conditions, so programming is now possible. Hop, skip, jump, and you're at your smartphone.\n\nHope that's a coherent overview. Source: Electrical Engineering graduate, 2012.\n\nEdit: Thank you for the gold /u/the_cosworth! I tried to keep the explanation ELI5-appropriate, but for those wanting more details, there are some great EE explanations in comment chain below this. They go into Bipolar Transistors, explain some of the alternate uses of transistors beyond a simple switch, etc. There's also some linked videos in the comment chain below that are excellent little classes on the finer points. Visuals help a ton. I'll try to drop a comment about the \"magic of chemistry\" in a bit if anyone still wants to know that.",
"The easiest way to think of a transistor is like an electronic switch. You can turn off the flow of current by applying a much smaller current to the transistor.\n\nSo imagine the flow of current in a circuit like cars on the street. The transistor is a stop light. When the light is green, the cars can flow. When the light is red, they stop.\n\nBecause electricity wants to keep flowing, with multiple transistors you can control the flow of electricity and use it to perform simple (or not so simple!) tasks. Imagine a circuit with two transistors. You could set it up so that if one transistor is on, a light lights up, and if both are on, two lights light up. Now you've made an extremely simple calculator that can only do 1+1.\n\nModern electronics are built off of the Integrated Circuit, which is actually thousands and thousands of extremely tiny transistors on a silicon chip. So imagine my silly little two transistor circuit. If you had many more transistors, you could make it do all kinds of things.",
"Others did Why to death (i.e. quite well) but I'm going to give a stab at the How.\n\n(TL;DR :: A transistor lets one wire \"act like a knob\" to control how much power goes through another wire.)\n\nSo you know how they say atoms are \"mostly empty space\"? Well there are these particles that are really small (protons, electrons, neutrons) but they claim a lot of space around them. All of physics and mechanical science and such is about those \"claims\" and how they interact.\n\nWhat do I mean by claim? You can get very close to a small fire, and even wave your hand through a candle flame, but if you build a great big bonfire there's so much heat that you can't get close. Indeed, if your fire is too big you end up standing out in the cold because the margin between close enough to be warm and too close to be comfortable becomes unworkable.\n\nSo particles claim space that's larger than themselves. One of their primary effective claims is \"charge\". We talk about positive and negative charges. It turns out that those words \"positive\" and \"negative\" are pretty much arbitrary. (Many argue that when Ben Franklin assigned the words he got them backwards, but that's another topic for another day.)\n\nSo an atom is some number of protons (positive charges) glued together by neutrons if there is more than one because, um, that's how it works. (i.e. we really don't know why, at the ELI5 level, neutrons are necessary.) And for every proton the atom wants one matching electron. This is because plus and minus attract and want to make a big zero.\n\nOn the other hand, physics demands that there be circles (or really \"clouds\") of electrons around every lump of positive stuff if you want that lump to be stable and happy. The first circle needs to be two electrons, then all the rest of the circles need to be eight. Why eight? Why the exception for two? More stuff that's true with no good ELI5 reason.\n\nThat conflict, the push-pull between one-plus-one-minus and two-or-eight is how all of chemistry works. When you see a molecule described, like water, H2O, it might be drawn as H-O-H. The little minuses are pairs of electrons, one from each of the neighboring letters. H, hydrogen, is one proton, so it has one electron, which is not two, so it borrows an electron from the Oxygen so its circle/cloud is two. Oxygen is eight positives, so it has eight electrons. It's inner cloud uses two so it's outer cloud has six, which is not eight. So it borrows an electron from each of the two hydrogens.\n\nBut wait! The hydrogen each borrowed one to make two, and the oxygen borrows two, so What the actual fark, amiright?\n\nThe electrons are very fast, so they just leap back and forth, doing double duty. So that line is a very hard, very real connection. It's like cheating, but it's allowed. Like being stuck doing both the grill and the chili at a barbecue.\n\nAnd that's basic chemistry.\n\nNow silicon (and other things like it) are \"Semiconductors\". They aren't good conductors, and they are not bad conductors, they are just so-so. And so \"semi\". Meh. (Note that \"meh\" here is relative. Silicon is _much_ better conductor than air or plastic, but things like gold and copper are just way, way better.)\n\nAnd if we looked at a perfect crystal of silicon we'd see a very ordered set of lines. And being all pure like that it barely conducts electricity at all (compared to say copper). That's because each electron is exactly doing it's job.\n\nSo we take that pure silicon and \"dope it\". We force it to accept some non-silicon atoms. Those atoms have just one too many, or one too few protons, which means there are one too many or one too few electrons.\n\nSo the resultant block has too many or too few electrons. Too many and the block is negative, Too few and the block is positive. Too many and it \"has electrons (it can share)\". Too few and it \"has holes (that can accept electrons)\". Either way, there's now more wiggle room for the electrons to literally skitter around and the silicon is a much better conductor than if every electron has its best spot.\n\nSo what happens when we mash two of those lumps, one positive and one negative, together?\n\nWell the positive part \"borrows\" the electrons from the negative part and it's happy but its now back to being crappy at letting electrons through... in one direction.\n\nThere's the magic!\n\nIf I keep putting electrons on the negative side, it can keep lending them to the positive side, and I can suck them out of the far part of the positive side.\n\nBut if I put electrons into the positive part I just make it even more impossible for the electrons to move around.\n\nIt's weird, but that's a \"Diode\".\n\nNow when that two-part lump is sitting there it's inherently a match of plus and minus. And when I run electrons in part, and suck them out of the other part, the total amount of plusiness and minusiness of the whole block changes.\n\nSo I can take that diode and add a _third_ block of stuff that's even _more_ plussy or minusy than the first two. As long as I put it on the far side of the \"same kind of stuff\". By that I mean I can do \"Positive - negative - positive\" or \"Negative - positive - negative\". It's got to be three layers and one has to be \"stronger\" than the other two, hence the capital letter.\n\nSo after I make this three layer sandwich, when I suck electrons out of the center (in the Npn case) or add electrons to the center (in the Pnp) case, there's that diode between the capital letter and the center doing the normal diode thing.\n\nBut now the second magic bit.\n\nAs the center gets more electrons added/removed the two ends with the same doping become able to \"see each other\".\n\nUnderstand that a \"Pp\" or an \"Nn\" block of silicon will just pass the electrons on after wasting some of the energy as heat.\n\nSo as you feed the interruption in the middle the electrons start to be able to go all the way through.\n\nThe more you stimulate the middle, the more electricity can get from end-to-end.\n\nIf you stimulate the middle \"enough\" it's like the middle piece was just removed.\n\nSo what does that practically mean?\n\nAt low currents a transistor is an amplifier. Put a little power on the center and a _proportionally_ larger power can flow from end-to-end.\n\nAt higher currents, known as the \"saturation current\", the transistor becomes an on-off switch.\n\nSo the transistors in your radio amplify the tiny signals received over the air into the big signals necessary to move your speakers and make sound.\n\nAnd the transistors in your computer, being operated at saturation, can do \"logic\" because by using switches in groups you do that AND/OR/NOT stuff.\n\nFinally, the smaller a transistor is, they less energy needs to be put on that center part, and the less heat is generated as the electricity flows from N-to-n or P-to-p.\n\nSo big honking transistors can operate real-world things (your stereo) and lots of tiny transistors can become a phone or a computer.",
"Some comments here have addressed what task the transistor performs but it is not just the transistor that can perform these operations. We have other components that can perform the same task but they can't be shrunk. Computer circuitry is actually immensely complicated. It has to be shrunk down to a microscopic level to be capable of the sophisticated computations of the modern era while still fitting in one room. The transistor is a device that we can make at a very small size. Before transistors we had vacuum tubes and before them, relays. They were used to do essentially the same thing but those parts are far bigger and less reliable than a transistor. Vacuum tubes also get too hot, another one of several disadvantages. If we tried to build a modern desktop computer with vacuum tubes or relays, it wouldn't fit in your house. Being able to built a massive circuit with parts that are smaller than a blood cell is a big reason why transistors are seen as crucial to the existence of modern computational capabilities.",
"/u/veritasium did a great video explaining this rather simply.\n\n_URL_0_\n\nTransistors are extreeeeeemely tiiiiiny switches with no moving parts, which are switched on and off by applying a small voltage which allows current flow through it's main part. \n\nThis small size means we can fit millions into chips to do more with. Previously we relied on glass coil/vacuum tubes for switching, each being the size of an eraser or bigger. Which obviously meant whatever we built was big and basic.",
"All of you guys are thinking of a transistor as used in a computer. A transistor isnt always an on off switch. It has a linear region where it acts as a variable resistor. For a very small current at the base it can control, in an analog fashion, a current through its collector and emitter. This is how a transistor works in an amplifier or radio circuit.\n\nMost of you guys are describing a digital latch circuit.",
"A transistor is a fast, reliable, and miniaturizable device allowing electricity to control itself. There are different types which work somewhat differently, but the basic operation is that there are two terminals plus a control terminal. In operation the current between the two main terminals is controlled by the voltage on the control terminal. The most basic use is as an amplifier: a small signal on the control terminal can control a large current, for example to transform the signal from the needle on a record player to something that can be fed to a loudspeaker. Things get better when you allow a process to feed back on itself. For example if you apply a phase shifted version of the voltage on one of the main terminals to the control you get an oscillator, so can build radio transmitters, for example. If you have a whole bunch of transistors you can do a simple computation on some set of inputs, each input being high or low voltage (representing ``0\" or ``1\"). If you can do simple computations, you can take the output and periodically feed it back as input to the same circuit. You then have a computer.\n\nThere are other devices that can similarly allow circuits to control themselves. For example vacuum tubes can in many ways be nicer for radios and such. But vacuum tubes are big, complex, and have a filament that burns out rapidly and breaks under mechanical stress. The size also causes speed limitations. Relays are great for designing computers with, but are also big, slow, and expensive with moving parts to wear out. Transistors on the other hand are produced by chemically altering a solid piece of semiconductor. They are shockproof, and don't have fragile or moving parts. They can be tiny and can be mass produced. The last point is a huge understatement, since now we build millions on the same piece of semiconductor, so you can have thousands of times the computing power of a building full of vacuum tubes in an inexpensive chip smaller than your fingernail.",
"Lets talk about a transistor as an \"amplifier\" device...\n\nA transistor has 3 parts: base, emitter and collector. The magic happens between the collector and the emitter and everything is controlled by the base. When you have a transistor acting as an \"amplifier\" you have basically the collector connected to the power supply, the emitter connected as the output and the base as the input.\n\nTo allow this to work, you have to polarize the transistor, that is basically provide 0.7 volts of difference between the base and the emitter. This will put the transistor in a state that any increment in the base voltage will make the collector to let pass the power supply voltage to the emitter. \n\nIt is like having a huge water box connected to a pipe and at the end of that pipe you have a huge hammer. On your hand you have a button. Every time you press that button, the water box dumps a huge flow of water thru the pipe and the hammer hits something with a huge force.\n\nNow imagine this: you tap the button 5 times in sequence. Five huge flows of water comes from the huge pipe and makes the huge hammer hit something violently five times. Then someone say: look, you have built an amplifier. Your light taps on that button provokes huge forces on the hammer.\n\nSo you get your amplifier. That is exactly like transistors work as an amplifier. A small sound reaches the transistor base and that makes the transistor open the doors and let pass the power supply voltage to the emitter that will eventually reach the speakers. So, a small voltage is \"amplified\" to a huge \"voltage\" that reaches the speaker and you hear as sound.\n\nA variation of this principle is used on computers to act as switches creating what we call \"Zeros and Ones\". Billions of transistors are combined to create a computer.\n\nThis is why you need a powerful power supply to have a power amplifier. Always check how much the power consumers. If it says it consumes 120 W but the company claims it delivers 2000W, something is wrong with that numbers. The amplifier cannot deliver more power that it is consuming. It would be a generator of energy... what is impossible. An amplifier will always produce less output in Watts than it consumes because part is lost in heat.",
"To make modern computer (and radio) circuits, we needed 3 critical things. Something that can allow current to flow in one direction, but not the other (a diode), something that can switch on/off other circuits based on a signal, and something that can amplify an input signal to be a larger output signal.\n\nTubes came first. Their smaller Cathode flings electrons at the larger Anode (but going the other direction, larger trying to hit smaller is harder, so it limits flow in the opposite direction). There's your Diode.\n\nOpposites attract, Likes repel, so placing a *grid* between the Cathode and Anode, allows you to Switch (or Amplify) an input signal to persuade (or hinder) flow of electrons between Cathode and Anode. (There's your switch and amplifier.)\n\nBut, tubes are (usually glass) large, heavy, fragile, and consume lots of power.\n\nTransistors (with 3 parts, and diodes with 2 parts) do the same job Tubes did, but are microscopic in size, and made (usually) of silicon. \n\nYou can *dope* a piece of silicon with (or with fewer) electrons, to make it N or P types. If you're N type touching a P type, then electrons like to flow from the N side (more electrons) to the P side (deficit of electrons). But, with fewer electrons on the P side, they have nothing to push to the N side, so they resist flow in the P- > N direction.\n\nIf you sandwich three layers (say NPN) then electrons like to flow from the N- > P, but resist flowing the next P- > N gap. If you apply a negative charge to the middle P layer, now you have NNN and electrons flow across the common structure. (There's your switch again. And if you vary the Amount (amplitude) of signal charging that middle P layer . . . you can adjust the amount of flow, and there's you Amplifier.)\n\nSo, a transistor is a microscopically tiny set of NPN or PNP layers of silicon, that does the same job of the older/bigger tubes. Allowing, Blocking, Switching, or Amplifying the flow of electrons, based on a signaling input. They consume lower power, are far less fragile, and last longer than their older tube counterparts.",
"A transistor is a non-linear device with linear characterisics. It's got three main modes of operation: off, linear, and saturation. None of these things mean anything to you probably but it's the foundation of all analog and digital ICs.\n\nLinear allows a transistor to act like an amplifier. BJTs are the first type of transistors used and have the best linear qualities which prevents signal distortion. You give the base of a BJT some current and you get along more current between the collector and emitter or signal gain. Think of it like using pulleys or a lever to GAIN mechanical advantage. The BJT was essential for things like radio and sensors where you needed to amplify small signals from inputs from antennas and physical sensors. \n\nSaturation allows a transistor to act like a switch. Saturation is a non linear characteristic of transistors meaning that you no longer have a linear gain e.g. for every 10uA you get 1mA output. After a certain threshold say 200uA, it doesn't matter what your input current is... you're only getting 20mA. Super simplistic but it delivers the point. Because of saturation you can start using logic levels as you can simply drive the transistor to saturation and it will act like a switch of either on or off.\n\nTransistor technology has significantly improved over the decades. BJTs make for good amplifiers, better than FETs, but consume much more power than FETs as FETs only require a field or voltage input versus a current input to get similar amplification effect.\n\nThe three modes of the transistor allow it to be built into other building block circuits like operational amplifiers and NAND gates which then are used to make more complex circuits.\n\nTo give a physical description of a BJT NPN transistor...\n\nYou've got 3 regions N-P-N which are the collector, base, and emitter respectively. By applying a forward voltage at the base and emitter it allows a current to flow between the collector and emitter provided a voltage has been applied between the collector apply and emitter.",
"How it works: Put very simply, it has 3 parts. A \"power source\" wire, an \"input\" wire, and an \"output\" wire. The power source (usually) always has power, and it's always trying to give that power to the output. But, it is only allowed to give the output power if the input wire is turned on. Think about your light switch. The power in the house is always on, but the lights are off. Why? Because your switch (the input wire) is off. Turn your switch (input wire) on, and the light turns on. \n \n \nWhy it's important: It is the building block for logical operations in computers. It works like and \"If...Then..\" statement. \"If switch is on, turn light on\". You can combine them in interesting ways to create AND, OR, XOR, and every other kind of comparison you would want. Once you had thousands of these guys together, you can make it run really powerful calculations, like running a game.",
"The book \"CODE\" by Charles Penzold is excellent at answering this question. It starts off by explaining electricity, goes on to explain transistors, then how they can be put together into logic gates. Eventually, you know enough to be able to build a simple binary mathematical calculator out of 1890s telegraph components (or transistors).\n\nThe explanations are fairly easy to follow and quite engaging. I recommend picking up a copy from Amazon Kindle.",
"there was this brilliant crash course episode, I'll search it for you and edit then.\n\ntransistors are nothing more but switches. You can use multiple switches to build logic operators (AND, NOT, OR etc.), the core building blocks of a modern cpu\n\nEDIT: [here you go](_URL_1_)\n\nthe whole series is highly recommended",
"Think of it as a valve on a water pipe. This valve is controlling a large flow of water.\n\nHowever, you don't turn the valve by hand, a tiny flow of water is what's needed to turn it, to control the large flow.\n\nNow, once you have this, you can start connecting pipes. You can have the flow in one pipe control the flow in other pipes, creating complex interactions.\n\nNow, water in pipes is kind of slow, big and cumbersome. A transistor, on the other hand, can be so tiny that you can't even see it with the naked eye, it's fast enough to change state billions of time each second and it runs on a flow of electrons, not water. This means that we can increase the complexity to insane levels. A chip can have billions of transistors, creating very complex operations.",
"Simplest explaination is a water value with a pressure based valve. In digital logic the value is either fully open or closed. You can make valves which open or close depending on pressure to let water pass. Analog, same idea, except you partially open and close. Big pipe, small control value and you have and amplifier. Pipeing in specific setups from no and full flow control valves make logic. voltage is like gravity trying to flow to ground, or lowest level/gnd using water. Resistors are like pipe size changes to affect the amount of water/pressure/current going through. Caps are like lakes sitting at different levels of elevation before ground. All together and you have electronics.. as ELI5 as I could make it without all the other crap to make Silicon.",
"Calculations by machine need switches.\n\nFirst were electro-mechanical switches.\nSize of small loaf bread. Relays.\n\nThen tubes or valves. Size of a Twinkie.\n\nThen transistors. Size of a dime.\n\nTransistors can be, were, are, shrunk down to nanometer scale.\n\nThis allowed for computers that were size of a building to be shrunk to cell phone size, and power to increase billions of times.\n\nYour smartphone? Runs on 8 cores of millions of tiny transistors.",
"Do you have a desk lamp? And a cable going to it has a switch button that provides power when it's on, and doesn't when it's off, right?\n\nTransistor is like a switch button. It connects or disconnects power to things inside computer. Some transistors are switched on when it's light is on, others when light is off.\n\nNow imagine a billion tiny lamps and billion tiny light switches arranged in crazy patterns, and they can flip billions of times every second without ever making a mistake - that's pretty much what computers are like!",
"There are a lot of good replies here explaining what transistors are. Now that you hopefully believe that a transistor works like an electric switch, I'd like to throw up a video that shows how you might chain them together to make digital electronics. More specifically, it's showing how you could use dominos to make a calculator.\n\nAny time that there's a place where dominos go in and out and there's a third leg running into that row, that's where a transistor would be.\n[Domino Addition by Numberphile](_URL_2_)",
"I would seriously recommend checking out crash course computer science. It is so well done and does a particularly good job at clearly explaining things starting down at transisto level, moving up to logic gates and all the way to modern programs, explaining how each step affects those above it.\n\nComputer Science: _URL_3_"
] |
why does Obama have a high approval rate among foreigners | [
"When people aren't subjected to the day-to-day politics of a particular country, it's easier to see a foreign leader favorably. For instance, Francois Hollande most certainly has a higher approval rating in America than he does in France. His policies wouldn't make for a viable candidate in the United States, but people here don't know what his domestic policies are. People in America have a favorable opinion of France and as a result, they have a favorable opinion of Francois Hollande.\n\nObviously, President Obama is far better known internationally than Francois Hollande. But contrary to what some thing, the United States is well liked in much of the world. Therefore, people have a favorable opinion of President Obama. \n\nAlso, if anyone is curious, [here](_URL_0_) is President Obama's approval rating in a variety of different countries."
] |
TTIP vs TTP | [
"TTIP - Transatlantic trade and investment partnership (free trade deal with EU)\n\nTPP - Trans-Pacific Partnership (free trade deal with countries around the pacific rim that aren't China)\n\nTTP - Thrombotic thrombocytopenic purpura (a rare blood clotting disorder)"
] |
- How a bill becomes law | [
"I will let School House Rock handle this one:\n\n_URL_0_"
] |
What is nymphomania and how does one become one. | [
"It can be like a drug addiction because of the chemical reactions that occur in the brain. You just wouldn't develop any type of dependency. However the craving, and desire is just as strong in all addictions."
] |
What is it about swimming that allows Michael Phelps to win so many medals? Why aren't there similar repeating winners in other sports, such as track and field that has multiple races with various distances? | [
"There are four different types of swimming strokes as well. If there were separate 100m and 200m dashes for regular sprinting, running backwards, crawling on all fours and hopping like a rabbit as well as relays for each type of running you'd eventually see a sprinter win a mountain of gold like Phelps'.",
"I think it speaks more about him than it does about the sport. He is basically how you would build the perfect swimmer. His body design is best for human swimmers. Even though he looks like a big dummy he must have the brain for it as well. He understands it. All of those things come together into him being better at swimming than everyone else.",
"In addition to the other answers, swimming is a sport that uses a very similar set of muscles and structure for everything. In long and short distance running, sprinters and distance runners are 'built' completely different, as are the people that jump. Phelps is an amazing athlete, and he's gotten very lucky that his athleticism crosses several events in the Olympics.",
"I don't know if it's so much about the sport as it is about him. His wing span is longer than he is tall (and he's already 6'4 tall), which allows him to take longer strokes. He wears a size 14 shoe which essentially makes his feet giant flippers. Add to that the fact that he is able to bend and flex his legs and feet more than the average person. He also produces less lactic acid than the average person, allowing his body to recover faster. He has a larger lung capacity than the average person. So, he is basically above average in anything that would make you a good swimmer. He's genetically designed to be amazing at the sport. But, when you also combine this with the fact that he is absolutely committed to studying the sport (you can see him on the side of the pool reviewing footage of both himself and other athletes), you have a freaking juggernaut.",
"Gymnastics is the closest to swimming in number of events one person can enter with a chance of winning. If you look at the top medal scorers ever they are mostly either swimmers or gymnasts. If you look at the list of swimming events it becomes pretty clear why there are so many swimmers with huge medal hauls. Consider that Freestyle and butterfly are essential the same motions just left and right in or out of phase. So if you're good at one of those you can feasibly do well at both of those. There are multiple distances for each of those and you could maybe perform well at both 100m and 200m. So we've already got a few but we haven't yet considered the team events. There's the 100m freestyle relay and the 200m freestyle relay you could also go in for, oh and the 100m medley relay too. You can do butterfly or freestyle in that, you're good at those. Hey you've got a good chance of winning something here. Wait we're not done, there's the individual medley to do and you're good at 2 of the 4 strokes already, you've got a good chance! There's two medleys by the way, 200m and 400m. \nIt's worth noting that other sporting organisations like in cycling put rules in place that limit how many events one person can do to limit the possibility of one country dominating. The swimming governing body doesn't seem to care. \nPS. Michael Phelps is the best swimmer there has ever been, I don't mean to diminish his achievements, I just think it's unfortunate that no one other than a swimmer will ever beat him. And it's also a shame that swimming is so overrepresented to the detriment of other sports.",
"There aren't many sports that have as many events in related skills. Swimming has a grid of four different swimming strokes, multiplied by a three common lengths (50 m, 100 m, 200 m, not to mention 400 m, 800 m, 1600 m in freestyle), plus individual medleys (all four strokes) in three different lengths (100 m, 200 m, 400 m), plus relays that are either freestyle or medleys in three different lengths. Just counting the common ones, that's about 20 events that all surround those four skills.\n\nCompare this with men's gymnastics, where there are medals for team, individual for each of the six events, and individual all-around, for a total of eight possible.\n\nAnd compare this with footraces, where there is basically running and hurdling and relaying in various lengths. Not as many.",
"The answer is that there are 4 different stroke, and while most people have to focus on one event (a certain stroke at a certain length i.e. 100m Freestyle) in order to be competitive at the olympic level, Michael is competitive at 3/4 strokes as well the Individual Medley, which is an event which you must swim every stroke. In track the equivalent would be, 100m two foot dash, 100m left foot dash, 100m right foot dash, 100m backwards runnings. And then having Usain Bolt being the best in all of those would allow him to get 22 medals."
] |
How do Kickstarter payments work? What prevents the receiver from just running away with the money? | [
"To my knowledge, nothing stops them. In fact there have been numerous complaints of people never getting what they order off of Kickstarter. It's very much buyer beware.",
"Nothing. You have no claim to anything when you donate. You aren't pre-ordering, you aren't buying it, you are donating money and you may (or may not) receive anything in return."
] |
Why we get shocked when we lick the top of a 9v Battery | [
"It works because you're completing the circuit, allowing electrons to pass from the positive terminal, through your tongue, to the negative terminal. As far as it being cruel, I've stuck my tongue to a fair share of 9v batts in my time and never felt anything more than a tickle or vibration feeling.",
"/u/MikeHunturtze has it mostly correct. Most of the electrical current is actually passing through your saliva, which is slightly conductive. If your tongue was dry, it would presumably be about as conductive as your skin. Which is not very. \n \nAlso, electrons don't go from the positive terminal to the negative one...it's the other way around. Electrons are negatively charged, and go from the negative terminal to the positive one. We say that current flows from + to -, but electrons flow from - to +. It is a funky result of calling electrons negative charge carriers. A negative charge flowing backwards results in a positive current. \n \nAnd he either has very few nerve endings in his tongue, or he's never licked a fresh 9V. Try it with a brand new one, and really press it onto the middle of your tongue. It's a lot more than mild, although it does pale in comparison to grabbing mains voltage."
] |
What exactly is happening when we suddenly don't need to use the bathroom anymore? | [
"That never happens to me with poop, but rather urine quite frequently when I'm active. Maybe it sweats out? Pissing your pants by sweating? ha"
] |
How is NASA 100% sure microbes aren't attached to the rovers and similar probes? When 99.99% sure means we're possibly spreading our alien microbes to other worlds. | [
"They aren't, and in fact, they're quite sure there _are_ microbes. They just get all of them they can.",
"They aren't 100% sure, and in fact we've found microbes that have survived into space. Simply put, it's hard to be 100% sure of anything. Sometimes you've got to risk it.",
"One feature of biology atleast here on earth, is evolutionary lineage, so part of the assumption made with sending scrubbed machines to other planets, is that if any of our bacteria are along for the ride, we will be able to ID them later. Deinococcus is one type of bacteria we're pretty sure is on the rover, but we know it's DNA sequence, and if we find life in the future that mirrors that genome, we can be pretty sure it wasn't there originally.\n\nBy the sheer astronomical odds, and probabilities of the universe, if we find life somewhere else, it WILL NOT, have the same genome as us, the same protein composition as us, and the same biological processes. \n\nIt might be similar, but physics pretty much make it impossible that life *exactly* like us is anywhere else in the universe. So long as it's not exactly the same, we're good. \n\nOne other thing, is that natural selection is still going on for the bacteria, and archea on the rovers. It is highly unlikely that they are better adapted to living on Mars, than the organisms already living there, so they won't take over the planet anytime soon."
] |
Why do sentences only rhyme when the rhyming word is in the back of the sentence instead of the front? | [
"A word is divided up into two parts. The first part is called the onset, the second part is called the rime. The onset is everything before the rime. The rime is what is used to make a rhyme."
] |
So is there an available fluid that could substitute blood flowing in our system? Like what's so special about blood? | [
"What makes it special is that it has red blood cells, white blood cells\nand platelets in it. The red blood cells carry oxygen . White blood cells\nfight disease and I believe platelets cause the blood to clot. The liquid\npart of the blood is called plasma."
] |
Why are our pupils more sensitive than the white around it? | [
"The white part of your eye (called the [sclera](_URL_0_)) is opaque, and is what primarily holds in the [eyeball juice](_URL_1_) that fills up your eyeball. \nThe iris is the muscular stuff that can constrict and change the size of your pupil. Your pupil isn't a structure: it's a hole whose size is changed by the constriction or relaxation of the iris. \nThe cornea is the part of your eyeball that sits in front of the iris that has the lens in it. \nYour cornea has more nerves in it than the sclera does. \nWhen you touch (or poke) the cornea, you notice it more because more nerves get triggered. \nThis makes sense, since the cornea is way more important than the sclera. \n\nHope this helps explain a bit.",
"Now to the real question: Why would you touch your eyeballs in the first place?",
"I'm an ophthalmologist. Your question would be more correct as \"Why is the cornea more sensitive than the conjunctiva\"? The cornea is the clear curved structure that lies over the colored iris. The central opening in the iris is the pupil. The pupil is the variable sized aperture which regulates the amount of light entering the eye. The conjunctiva is a thin translucent mucous membrane which lies over the whites of the eyes (sclera).\nNow, both the clear cornea and the opaque white screen are made up of collagen. The difference is that the cornea is important optically. The cornea is exposed to the outside world and has the greatest concentration of sensory nerves compared to anywhere else in the body. Evolutionarily, it makes sense. If a foreign body lands on your skin, no big deal. If a foreign body lands on your cornea and scratches it and you develop an infection, you could go blind. It's not as critical over the whites of the eye. TMI, probably. I hope that was understandable."
] |
How does the umbilical cord attach itself to the child/mother? | [
"Conceived in the fallopian tubes or top of uterus.\n \nFertilized egg drops down into uterus, where it lands in a 'bed' of what is essentially blood*. \n\nBecause the egg is fertilized, it gives off chemical messengers that it will be sticking around, so it doesn't get flushed out when it's time for her period.\n\nOver the next few weeks, the fertilized egg which is a single cell, begins to divide and becomes a mass of cells. \n\nSome of those cells differentiate/change into what will become the placenta.\n\nThe baby's placenta cells grow like roots and implant into the 'bed' of ultra enriched 'blood' that lines the wall of the uterus. \n\nEventually, the placenta cells become blood vessels that are rooted into the wall of the uterus, where the host...err...mom gives nutrition and oxygen, and takes away CO2 and cellular waste, via the umbilical cord.\n\nMom < -- > Uterus < -- > Placenta < -- > Umbilical Cord < -- > Baby\n\n*That 'blood' lining that allows the egg to implant, is what a woman expels every month during her period. If a woman 'misses' her period, it's because a fertilized egg made it into the lining, and told her body to not release it."
] |
What's going on in Texas with planned parenthood and medicaid | [
"The government gives money to various programs. One of which is Woman's Health. The Woman's Health program gives 40 million dollar to Texas for Woman's Health clinics. One of the largest Woman's health clinic is Planned Parenthood group which does Pap smears, gynecological exams, and mammograms. Planned Parenthood also does family planning, STD screen and provides abortion as well.\n\nThe Texas governor doesn't want money to go to Planned Parenthood but the law that the federal government uses to give out money for Woman's Health say you can't restrict which Woman health clinics get the money. This is for multiple reason, the largest being that it would allow the State to control which Treatment the Woman get. As such when Texas passed a law saying that Planned Parenthood could not get money, all federal money had to be stopped.\n\nUnder a previous law no federal money can go to support abortion so the money was not going to support abortion, merely Planned Parenthood other activities which have been listed.",
"It has nothing to do with politics and everything to do with powerful people who feel they are losing total control of everyone's life. If you notice, they pass nothing that is in anyway harmful to them it either harms someone someone else directly or it benefits them directly. They never do anything to benefit anyone else if it in anyway is harmful to their ego, or their position."
] |
Why do we impose 'tougher' sanctions against N.Korea each time they do something instead of throwing every we can against them all at once? | [
"For a long time, any action against North Korea was forestalled because they were allied with the Soviet Union and China and no one wanted a war with them. In fact we'd had a war, the Korean War, and fought it to a standstill. After the Soviet Union collapsed, North Korea still had an ally in China. However, as time has gone on, North Korea has gotten crazier and crazier and China has gotten stronger and cares a lot less about North Korea. At the same time, due to the lack of support from the Soviet Union, North Korea has become a hellhole, with the residents suffering greatly and experiencing at times widespread starvation under the oppression of Kim Il-Sung and then Kim Jong-Il and now Kim Jong-Un. Many countries, including the US, have sent them a lot of food aid because we have recognized that the people of the country are not to blame for the actions of the leaders, and it was a humanitarian crisis. \n\nMeanwhile, North Korea has developed nuclear weapons. Not many, but some. And it is feared that Kim Jong-Un is crazy enough to use them if he's backed into a corner, which he would be if attacked. So concerns about that, as well as concerns about the problems of fighting with China, have prevented any major action against the North Koreans."
] |
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