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26ssmj | ethanol in fuel - what is it? why is it added? is it good/bad and why so? | Every gas station I go to has stickers all over the pumps that say "Contains 10% Ethanol". What exactly does that mean? Is it a good thing or a bad thing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26ssmj/eli5ethanol_in_fuel_what_is_it_why_is_it_added_is/ | {
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"E10 is a blend of gas/alcohol made from biomass (corn, usually). Most modern cars are just fine running it. E85 is a different beast, however - the concentration of ethanol is much higher (as is the octane rating), making engine management / fuel system changes necessary (usually engines require higher flow injectors/pump to run E85). The higher the concentration of alcohol, the worse mileage you'll get, but it's usually offset by being lower price per gallon.\n\nIf you have a turbocharged car, an E85 tune can really be a godsend since its high octane rating means it will be less likely to pre detonate under higher compression. ",
"It's worth noting that ethanol is the alcohol in \"alcohol\" that you drink. ",
"3424dfjlksi3 answered your question quite well. There are, however, some implications with older vehicles which were not designed to run on Ethanol blended fuels.\n\n-Petroleum itself has lubricating properties which are beneficial for the longevity of the engine. Most four-stroke engines use a sump of oil which finds its way to the cylinder walls/piston rings by splashing around, and pressurized engine oil is injected to the bearings and other key locations. Four-stokes tend to not be effected very bad. Two-stroke engines are a different story though. Oil is mixed with the fuel and the mixture travels through the engine before winding up in the combustion chamber. The presence of Ethanol has a negative effect on the lubrication property of the Fuel/Oil mixture.\n\n-Ethanol is hygroscopic (absorbs water). This has a negative effect on how long the fuel can be stored. On older vehicles it also attributes to rust inside of the fuel tank.\n\n-Ethanol in fuel will tend to crack any seals made of Cork or natural rubber. If lots of steel is used in the fuel system, it will tend to corrode. The last 20 or so years nearly all fuel seals are made of Neoprene Rubber which resists this 'drying out'. Just be warned using it in classic cars or motorcycles.\n\n-Ethanol is much less energy dense. This means way less mad skids, and less braaps. This is a big issue, because the world desperately needs more mad skids, and more braaps.",
"I work with a lot of small engines (weed eaters, leaf blower etc.) and everyone says ethanol tears them up. Is there any reason why ethanol would be worse in a small engine then a car engine?\n\nOne thing I do know is that ethanol has a lower boiling point. This can be a problem for boat motors. These don't have radiators to cool them instead relying on the surrounding water. If you try to add fuel to a hot boat motor the ethanol will evaporate causing vapor lock and failure to start. This is why near lakes you will see stores advertising ethanol free gas. ",
"Here is the history, as I understand it: \n\nThe U.S. has a lot of corn farmers and a REALLY strong federal lobby group. The bottom fell out of the market decades ago, and the lobby group pushed the government to begin subsidizing (they also subsidize other products, but corn is the largest). There was still no real market for corn internationally, so the government mandated ethanol into gasoline production. Other countries followed suit as a \"green\" practice of saving oil. Unfortunately, ethanol burns poorly, and there is some question about whether there is any environmental benefit found after the impact of production.\n\nAs a couple of other people have pointed out, there's also some major issues around using a food product for a fuel source. It wreaks havoc on the corn market, artificially inflating prices, and indirectly contributing to global starvation.\n\nFWIW, I understand that there are a few strong alternatives to ethanol--particularly from algae--which are much better suited to be used in combination with petroleum. The problem is that dropping corn would have MASSIVE economic repercussions for the U.S. economy, and corn producers continue to have strong lobbying ties in the gov't.",
"Ethanol has 2/3rds the BTU potential of gasoline. Your gas is essentially watered down and you get less mileage. It is an inferior fuel in terms of power, so ethanol blended fuel has less bang for your buck.",
"IT contractor sitting in an ethanol plant right now. Raised in a rural community. My sister works at a food grade corn elevator. My dad is an engineer for a Pivot manufacturer.\n\nThere's a lot of both good and bad information here. Even I don't claim to be an expert on the matter. But here's a few small things I can offer: \n\n1. There are lots of different ways to produce ethanol, not all of them use utilize corn. \"Biomass\" ethanol plants specialize in utilizing other parts of the plant besides the seed (stalks, leaves, etc.). This is less efficient than using the grain, but at this point anything that we can produce locally that helps reduce dependency on foreign oil I see as a plus. \n\n2. Ethanol production does not utilize food grade corn for human consumption. Most of the corn ethanol plants buy was previously used for livestock feed or any number of other industrial uses. A GREAT thing about this is that the Ethanol production actually doesn't stress those other markets much at all because production of ethanol also creates by-products that are sold into those markets (dry distillers grain, wet feed, syrup, etc.). The Ethanol industry actually fits rather nicely into this middle market where they can produce multiple products for multiple industries without those individual industries having to pay to process raw corn. Of course ethanol has contributed to changes in our market over the last 15-20 years, every new product that has ever been created caused an impact on our economy in some way minor or major. Markets change and adapt to survive all the time. I agree with subsidies to help encourage investment into new technology and products, but I believe the ethanol production market is reaching a maturity point where it needs to sink or swim on its own in the next 10 years or so. In fact, the ethanol plant I'm currently sitting in was shut down last year for 2 months because the price of corn was too high!\n\n3. Until the whole planets energy needs can be sustained from solar power we are tied to the resources produced here on planet earth. Since the first time man burned a log to make a fire we've been consuming natural resources in order to perform \"work\" (as a physics term). Utilizing as many RENEWABLE sources of energy as we can and weening off of coal/oil will be beneficial for our long term future. \n\n4. If you really want to cash in on the high corn market, look at agri-business and ag-tech companies. Farm equipment manufacturers, Agronomy, etc. are all BOOMING because of advances in technology with GPS, mapping, irrigation etc. Farmers are investing in technology because of high corn prices and the proven ROI it can produce. I do IT work for a lot of farmers as well and they are finally jumping on the Tech bandwagon especially in the last 3-5 years.",
"Ethanol is added for pollution control and for political reasons.\n\nYes, it stabilizes fuel, (raising it's Octane rating) but that's secondary.\n\nIt's cheaper at the pump for political reasons; ethanol is subsidized by the State and Fed. That means you're paying the difference in your taxes, whether you use it or not. In reality, the total cost is more than gasoline. It's subsidized because the corn industry has extremely influential lobbyists and substantial financial backing. Looking cheaper at the pump promotes its consumption, validating the lobbyists. It's a circle of bullshit to hide how bad an idea it is from government members who don't actually give a shit one way or another, and people are too busy living paycheck to paycheck to take the time to know or understand what's going on.\n\nFlex Fuel cars are piece of shit cars. Configured to run off both, such cars are terrible at operating with either."
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eqraqn | how are plant seeds, which are being sold commercially and are super dry, able to germinate even after a long period of time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/eqraqn/eli5_how_are_plant_seeds_which_are_being_sold/ | {
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"A lot of plants in nature can't rely on the seeds immediately ending up in an ideal environment to germinate. So the plant evolved to produce seeds that can lie dormant for awhile. So along with the plant embryo, seeds usually contain food for the embryo in the form of fats, carbs, and proteins, all packaged up with the embryo in a hard outer shell to keep the seed from spoiling or drying out. When conditions are right and the seed is in moist soil, it kick-starts the embryo's growth, which first eats the food in the seed while it forms a root system to allow it to get nutrients from the soil and leaves to photosynthesize.\n\nSide note: it's because of all those nutrients in the seed that much of the plant foods we eat are seeds or derived from seeds. (Whole wheat) flour is milled wheat seeds. Nuts are actually seeds, so are beans, peas, quinoa, rice, oats, etc."
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7s8d0e | why do musketeers have swords instead of muskets? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7s8d0e/eli5_why_do_musketeers_have_swords_instead_of/ | {
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"Musketeer is literally the word to describe a soldier equipped with a musket.\n\nAnywhere you see a musketeer without a musket, it has either been disarmed or tossed away during close combat.",
"Musketeer literally means \"person armed with musket.\" And in a big-time, army-on-army battle, they'd be the ones firing muskets into the other guys. And they'd have a sword as a backup in case they ran out of ammo or had a malfunction... or the other guys got close. \n\nBut the Musketeers made famous by *The Three Musketeers* were part of a group called the Musketeers of the Guard, who were basically the royal guard for the King of France. The problem with a musket was that it wasn't very accurate. Like at all. And they take a while to reload. Like minutes, not seconds. Which is fine when you're shooting into another army, because you'll probably hit *something,* and you can probably get a few shots off. But when someone's trying to attack your king, or when you're fighting a nice swashbuckling duel in a book, the cleanest way to take out the bad guy was still a sword, until better firearms were developed. And since that's the kind of stuff that's happening in the book, that's the image we have of the Three Musketeers."
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1kyxf2 | youtube's buffer. it buffers, but if your internet gets turned off, the video stops. it never used to be like this. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1kyxf2/eli5_youtubes_buffer_it_buffers_but_if_your/ | {
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"This is maddening. I used to be able to pull up a video, let it load all the way, then be guaranteed that I could get through the whole thing without it stopping to buffer midway through. I would definitely like to know why they changed this (I imagine it's to stop some type of abuse, but I don't know for sure).",
"They changed their way of loading videos to prevent people with fast connections loading the full video in several seconds and then just skipping to the next video, before viewing the complete clip, generating huge amounts of bandwith for YouTube/Google that's used for nothing and thus costing them money for nothing. Now they use a \"load on the fly\" mechanism which can be in your disadvantage if you have a slower connection or have trouble with your connection from time to time. This basicly works very simple, from when you've reached for example 40% of the video, it will load until 70%, 45% until 75% etc. I also think it depends on the length of the video how it calculates the amount it will pre-load/buffer but I'm not sure about that.\n\nHope this answers your question.",
"[Here](_URL_0_) is an extension to fix the problem in firefox. You can customize the way it will buffer/play and a few more things."
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cs4cbo | i spilt bleach on my clothes. why are some clothes extremely discolored and others unaffected? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cs4cbo/eli5_i_spilt_bleach_on_my_clothes_why_are_some/ | {
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"No clothes are unaffected by bleach. Bleach is very reactive, and it breaks the bonds in coloring molecules, changing them to other molecules without the same color.",
"Natural fibers are dyed, meaning the fiber is first its in it's natural state (for cotton, white, etc.) and then a dye is overlaid on the fiber. Bleach strips the color off of the fiber and returns it near it's natural state. \n\nLots of synthetic fibers like polyester aren't dyed. The plastic used to make the fiber itself, is colored throughout. Instead of being and addition of color, the base fiber is colored throughout. It's natural state is colored. When bleach is added, it can't strip the color away because it's embedded within the fiber."
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1og4lm | how did people get their drugs delivered from silk road without getting caught? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1og4lm/eli5_how_did_people_get_their_drugs_delivered/ | {
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"\"I love the UPS guy, because he's a drug dealer and he doesn't even know it.\" -Mitch Hedberg",
"My understanding is at least some of the sellers would send vacuum-sealed packages through USPS. ",
"If you know what you're doing, you can send packages by UPS and FedEx (and even good ol' USPS) and offset if not eliminate a lot of the risk of being caught. For example, your dealer can pack a box, waive the signature requirement, blank a return address (or use a phony), pay cash, weigh the parcel at an automated kiosk, and put it in a drop box. Unless someone witnesses him do most or all of this, who's to say he ever sent the package? And if the UPS guy is actually a narc who busts you on your doorstep, so what? You weren't knowingly receiving drugs - you were just opening a mysterious package that you were obviously not anticipating. How could you possibly know that it contained narcotics?\n\nIs it a perfect system? No. But it's reliable. Without the usual paper trail (credit card transactions, signatures, return addresses), law enforcement's job gets a lot harder.\n\nAlso, I mentioned USPS parenthetically because it's a little less viable, in my opinion. I recently spoke to a friend of mine in California about sending me...things, and was informed that all of the post offices in his area (and maybe all statewide) scanned their packages before sending them.",
"The packaging is very discreet (usually, unless it's domestic), to the point that even if the package was x-rayed or looked at in a light, or even opened, it would raise no suspicions. Those guys are pros, you know. One would just order it and taking a sweaty trip to the post office and hope for the best. 99% of the orders show up without incident, it's kind of funny. I think it's just a matter of it being frowned upon to look in people's mail, and customs not having the means to detect them with real ease. That, and when you're paying the post office, they don't give a fuck what you're doing, they just smile and say hi.",
"Made a new account just so I could answer this from personal experience;\n\nI've had hundreds of packages shipped from TSR both to my house and to a private P.O. box, I primarily ordered MDMA, LSD, Cannabis seeds, and occasionally cannabis (most I ever ordered was 4oz at one time).\n\nNow, let me break down the process from where I started, and luckily I had a better introduction to it than most people. \n\nI was introduced to TSR by a friend who we'll call Bob. Now Bob had been pretty familiar with ordering drugs and weapons off of the darknet through different distributors, so when I mentioned my interest in it he offered to order me a fake SS card and a fake ID so that I could open a P.O box under a fake identity. \n\nNow comes my own experience with it- first off I kept all of my orders domestic so I wouldn't have to deal with US customs. All of my orders came from 3 different cities- 1. West Lafayette, Indiana 2. Portland, Oregon 3. New York City, New York and they were getting shipped to the midwest. \n\nObviously different drugs have different odors, so my distributor for the different substance would obviously package it in different ways. For MDMA they'd vacuum seal it 3 times, dipping the bag in alcohol each time- apparently this allowed the MDMA to be undetectable by drug sniffing dogs and other odor recognizing factors for up to 72 hours (i don't know how true this is, but this is how i was reassured) and then put the bag into a t-shirt or different article of clothing and send it with phony labels from the manufacturer of the actual item (I'd get a lot of packages from Express in specific. I don't know why they'd fake those labels, but that's how they decided to). For Cannabis then they'd vacuum seal it 5 times, dipping it in alcohol each time, letting it dry, then pouring coffee grounds between the layers of bags and then put the actual bag with cannabis in it in a Starbucks coffee bag, and then once again they'd make false labels as if it were coming from a Starbucks distribution centre to my address. With LSD then they just put the vial of liquid inside of a highlighter or various other crevice and then ship it directly as such- IMO this was the sketchiest operation.\n\n\nAnyway I'm [7} and ranting- but once the actual package was delivered, I'd leave it alone for a week. If it was shipped to my house i wouldn't bring it in, I'd just leave it on my front porch and if the feds didn't come and grab it, then I was okay. If it was shipped to my P.O. box, I'd wait 14 days before going to check it. I was a little extreme with my precautions of the P.O box though.\n\nHope this kind of explained it"
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c2njng | why you can chug almost all drinks, yet alcohol is so hard to chug. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c2njng/eli5_why_you_can_chug_almost_all_drinks_yet/ | {
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"Not always, if you mix up a good cocktail without too much bubbles it's not too hard to chug",
"Alcohol is a very good solvent. We divide stuff into water based and fat based. Water dissolves water based things but not fat, fat solutions dissolve fat based things but not water. Alcohl essentially has a water end and a fat end so it can dissolve both water and fat based things. \n\nThis is why alcohol is such a good cleaner and disinfectant. It is also why it burns, it is stripping the outer layer of your throat. But it requires more pure alcohol to do that, a low alcohol drink will not. And if you drink a lot of alcohol you won't notice the burn"
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9gaaba | why can’t hurricanes hit land and turn into tornadoes or vice versa? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9gaaba/eli5_why_cant_hurricanes_hit_land_and_turn_into/ | {
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"Because they're totally unrelated weather phenomenon. Superficially they might seem similar in that they both rotate and have high wind speeds, but that's where the similarities end. ",
"Hurricanes are huge weather systems that are hundreds of miles wide. Tornadoes are localized events within a larger weather system that are at their largest about 1 mile wide. Trying to take something that is 300 miles wide and force it into something that is 1/71,000th its size just because it travels over land isn't going to happen."
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2eq23q | why do we need three different sizes of hdmi plugs? | Or, any plugs that have several sizes for that matter.
Why do we even need so many sizes? What is the problem with just having the smallest one? Even if the larger one is more reliable (is it?), is there really a need for all three sizes? (in the case of HDMI).
It is quite annoying to have all the adapters, when it is essentially the same thing. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2eq23q/eli5_why_do_we_need_three_different_sizes_of_hdmi/ | {
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"Usually the largest plug size comes first. Then, when technology gets a bit better, if people want to rearrange it to a smaller size they usually do.\n\nPeople don't immediately switch to the smaller size because there are already a lot of devices using the larger sized plugs.\n\nIn some cases though the different sizes are for slightly different uses. Smaller plugs can sometimes be more delicate than larger ones, which can make them unsuitable if there's going to be a lot of wear."
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1uf94m | now that pot is legal in colorado, how are the surrounding states dealing with it? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1uf94m/eli5_now_that_pot_is_legal_in_colorado_how_are/ | {
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"It is hard to foresee the economies of this, but in the big picture there will be fewer shortages in those states, and possibly in any state within a thousand miles. The drive to eradicate pot could be over, but in the short term the producers in Colorado may find themselves producing for half the nation.",
"I go to school in Wyoming and the whole state is pissed. They are going to beef up the highway patrol men and have a some kind of border patrol. The university sent me an email saying pot is still illegal here and there will be more police so don't bring any pot back here."
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4cyr7i | what makes music "music" instead of random noise? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4cyr7i/eli5_what_makes_music_music_instead_of_random/ | {
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"Culture is a part of it, but it's also about our brain's pattern making ability. Music is music because it is a pattern of notes set to a beat. When you change the pitch, you're changing the mathematical relationship of the notes and disrupting the pattern. ",
"Tension and release. In western music we build tension using dissonant chords and then resolve them and that gives a \"pleasing\" experience to our ears. [video link to chord resolution](_URL_0_)\n\nThat is basically the easiest and simplest way to explain it. Once you understand what makes sounds music, you end up with musicians who turn that preconception on its head and we end up with [Meredith Monk](_URL_2_).\n\nOr other modern composers who follow a modified traditional understanding of western music, like [Eric Whitacre.](_URL_3_)\n\nAnd the pinacle of tension and release music, for me, is barbershop music. [Westminster Chorus' Seize the Day](_URL_1_), from the musical Newsies.",
"Certain audiologists had studies showing a link between certain frequencies and such, and how they affect how we feel about that sound. However you have to realize even if it is 100% true this only forms a base reason and does not explain much else. \n\nQuite a bit of it is personal and cultural taste — Arab/Chinese/etc music you've heard it sounds \"off-pitch\" sometimes to western music lovers (and likely vice-versa to a pentatonic music culture), but a certain \"consistency\" and repetition in the sound waves themselves that separates it from noise. \n\nOh and speaking of repetition there's also one study that showed that when you c+p a bunch of segments from a piece of music (of a composer from the school of thought that said repetition in music is a hindrance), people liked the \"remixed\" version better. They're chains keeping us from enlightenment, sure, but it sounds nicer. Take that as you will, I heard it from NPR not from a journal so all this is is a suggestion. \n\nAnd the concept of music v noise is actually being challenged by some artists (wether they'll make an impact is another story). Merzbow for example just plays plain static noise if you search him up, but while it is unmusical to a certain degree, you can hear variations in the shape of the sound and while I wouldn't put him on a playlist he certainly makes a good exercise as to the futility of trying to categorize music v noise.",
"It has to do with things like melody, harmony and such. Music is built to sound like more than just noise, and there's a lot of theory around what sounds good and what doesn't, which comes down to the frequencies of the sounds and their ratios to each other. \n\nYou may find this introduction to composition interesting: _URL_0_"
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35shu4 | what is actually happening to heroin addicts or hard drug users when they "nod off"? | Are they actually falling asleep or are they in such a euphoric state that they can't maintain consciousness? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/35shu4/eli5_what_is_actually_happening_to_heroin_addicts/ | {
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"As a former opiate addict, I would nod because I was so high that I had actually surpassed my euphoric state. As in I should have not snorted that last line because this isn't fun anymore. Nodding also used to happen for me when I would try to pay attention in class or something and had no other stimulation so boredom made me nod. Honestly I always felt so tired when I nodded and didn't feel high anymore."
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4buolf | why do graphics that show how gravity works always depict spacetime as a 2-dimensional surface (like a stretchy piece of rubber with heavy balls sitting on it representing planets & stars) - and how would it look if spacetime was shown in 3 dimensions? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4buolf/eli5_why_do_graphics_that_show_how_gravity_works/ | {
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"It is done because it is significantly easier to do so in two dimensions. This is also generally okay because it saves you a ton of work that wouldn't really add to your understanding of the subject. You don't really gain much by adding a third dimension outside of seeing it in three dimensions, and abstracting the two dimensional picture into three will get you a pretty good idea of what it looks like.\n\n > What would a black hole's gravity well look like in 3D? (In 2D it looks like a funnel, but wouldn't the funnel's bottom be in the middle of the black hole if it was 3D?)\n\nIt looks like a sphere where everything is falling towards the center.",
"Because a 3D sheet would require working in 4 dimesions which can neither do nor comprehend. When you have the 2D sheet the gravity is shown by moving in the third dimension. So on a 3D sheet gravity would be shown by moving in the fourth dimension.\n\nAlso it would add nothing to the explanation to add the extra dimension were it possible"
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3o8ler | how do worms get into foods like mangos and eggplants without piercing the skin? | I've cut into the foods and found worms in them. How do they get in without puncturing the skin? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3o8ler/eli5_how_do_worms_get_into_foods_like_mangos_and/ | {
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"Bugs lay eggs in the flowers, the flower turns into a fruit, and then the egg hatches. The worm comes out of the egg."
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jgoxv | how do you use git and github? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jgoxv/eli5_how_do_you_use_git_and_github/ | {
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"This won't be like your 5, because explaining git to a 5 year old just wouldn't work:\n\nGit is a distributed version control system. Consider it an ordered list of changes that a set of files have recently undergone. It keeps track of who changed them, what was changed, why they were changed (according to the person who changed them) and when they were changed.\n\nIt also allows people to pull updates from eachother. So if you and I are working on a project together and I update the readme, you can pull the change I did and update your local files so that they are exactly in sync with mine.\n\ngithub is a centralized area where people can organize and track their code and its changes. Consider github itself as just another person that wants to keep track of your code, except that you push your changes to it instead of having it pull from you. It then reads details from the files which contain all the properties regarding the repository (the entity which git manages) and displays them as easily readable graphs and information for users.\n\nThere are a few commands you should be aware of when trying to use git for the first time:\n\n* (google)\n* git clone\n* git pull\n* git status\n* git add\n* git commit\n* git push\n* git log\n\nI highly suggest finding the free book 'Pro Git' online (it's also $15 for kindle which I recommend, as it supports the author). \n\ngit clone will \"clone\" a remote repository to a destination which is local to your machine (or anywhere you can reach via command line).\n\ngit pull will update your local repository (where you cloned to) with code from that remote repository (clone will get you to the latest revision when it executes)\n\ngit status will show you the status of any changes you have in your working tree (your working tree is all the files in the current repository that git sees).\n\ngit add will add files to the staging location after they're changed (or if they're untracked, will mark them to be tracked after the next commit)\n\ngit commit will apply your staged changes (through git add) to the repository. It will open up a text editor and ask you for a commit message (for you to explain the changes you just made to the files). Or you can use 'git commit -m < msg > ' to add a message inline\n\ngit push Updates a remote repository (like github) with your latest commit (in your current branch, but don't worry about that for now.)\n\ngit log will show you a list of changes that have happened since the beginning of time (according to this git repository).\n\n\nHoped that gave you a good place to start.",
"5 year old explanation:\n\nYou and Billy decide to draw a picture together with crayons, but you both want to be able to work on it from home. The teacher makes 2 photocopies of what you have started and you both take a copy home (pulling/checking out). You both add more things to the drawing and when you come back to school tomorrow, the teacher cuts and pastes the bits you added / changed and then photocopies that (merging). If you both colored in the same area, someone has to choose which portion to use (resolving a conflict). And since there are photocopies every time something is changed, you can throw away all the new ones if you don't like what you've done (reverting).",
"_URL_0_ is a great tutorial for Mercurial. Mercurial is another VCS that is conceptually similar to git, so try to absorb the concepts, not the exact commands.",
"Alright, I have to admit, this isn't the way I'd explain GIT to a 5 year old (I quite like [m00n3r's post](_URL_0_), but if you want a simple, though length, discussion of GIT, check out *[Pro Git](_URL_1_)* (free).",
"How is it different from perforce? I see that github website only has 25(?) maximum repository. My organization has 1000s in perforce with 100s of users. Is github, in anyway, better than perforce?",
"Here I am sitting and wondering the same thing until I read this post.\n\nI love reddit. ",
"git gets easier once you get the basic idea that branches are homeomorphic endofunctors mapping submanifolds of a Hilbert space",
"This won't be like your 5, because explaining git to a 5 year old just wouldn't work:\n\nGit is a distributed version control system. Consider it an ordered list of changes that a set of files have recently undergone. It keeps track of who changed them, what was changed, why they were changed (according to the person who changed them) and when they were changed.\n\nIt also allows people to pull updates from eachother. So if you and I are working on a project together and I update the readme, you can pull the change I did and update your local files so that they are exactly in sync with mine.\n\ngithub is a centralized area where people can organize and track their code and its changes. Consider github itself as just another person that wants to keep track of your code, except that you push your changes to it instead of having it pull from you. It then reads details from the files which contain all the properties regarding the repository (the entity which git manages) and displays them as easily readable graphs and information for users.\n\nThere are a few commands you should be aware of when trying to use git for the first time:\n\n* (google)\n* git clone\n* git pull\n* git status\n* git add\n* git commit\n* git push\n* git log\n\nI highly suggest finding the free book 'Pro Git' online (it's also $15 for kindle which I recommend, as it supports the author). \n\ngit clone will \"clone\" a remote repository to a destination which is local to your machine (or anywhere you can reach via command line).\n\ngit pull will update your local repository (where you cloned to) with code from that remote repository (clone will get you to the latest revision when it executes)\n\ngit status will show you the status of any changes you have in your working tree (your working tree is all the files in the current repository that git sees).\n\ngit add will add files to the staging location after they're changed (or if they're untracked, will mark them to be tracked after the next commit)\n\ngit commit will apply your staged changes (through git add) to the repository. It will open up a text editor and ask you for a commit message (for you to explain the changes you just made to the files). Or you can use 'git commit -m < msg > ' to add a message inline\n\ngit push Updates a remote repository (like github) with your latest commit (in your current branch, but don't worry about that for now.)\n\ngit log will show you a list of changes that have happened since the beginning of time (according to this git repository).\n\n\nHoped that gave you a good place to start.",
"5 year old explanation:\n\nYou and Billy decide to draw a picture together with crayons, but you both want to be able to work on it from home. The teacher makes 2 photocopies of what you have started and you both take a copy home (pulling/checking out). You both add more things to the drawing and when you come back to school tomorrow, the teacher cuts and pastes the bits you added / changed and then photocopies that (merging). If you both colored in the same area, someone has to choose which portion to use (resolving a conflict). And since there are photocopies every time something is changed, you can throw away all the new ones if you don't like what you've done (reverting).",
"_URL_0_ is a great tutorial for Mercurial. Mercurial is another VCS that is conceptually similar to git, so try to absorb the concepts, not the exact commands.",
"Alright, I have to admit, this isn't the way I'd explain GIT to a 5 year old (I quite like [m00n3r's post](_URL_0_), but if you want a simple, though length, discussion of GIT, check out *[Pro Git](_URL_1_)* (free).",
"How is it different from perforce? I see that github website only has 25(?) maximum repository. My organization has 1000s in perforce with 100s of users. Is github, in anyway, better than perforce?",
"Here I am sitting and wondering the same thing until I read this post.\n\nI love reddit. ",
"git gets easier once you get the basic idea that branches are homeomorphic endofunctors mapping submanifolds of a Hilbert space"
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254nrm | why is does our society thrive so much on negativity? | You see it everywhere these days. Rampant fanboy bitching about upcoming video games, movies, etc. Reality shows focusing on negative archetypes in society. News media outlets focusing on major tragedies. Why does our species embrace it so much? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/254nrm/eli5_why_is_does_our_society_thrive_so_much_on/ | {
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"Well, how did making this post make you feel? Did it vent your frustrations and dissatisfaction?",
"Maybe we take good things for granted to a degree. So the bad things catch our attention, and we talk about them. I hear a lot of people asking questions like \"Why is the world so messed up?\" rather than \"Why is the world so great?\". I can only assume they're venting or they want an answer, a change that'll fix the 'problem'. When everything is great, you don't really feel a need to comment on it, you just live in the moment.\n\nIt makes sense from a functional perspective as well. \"Our food stores are almost gone!\" would be a much more pressing issue than say, \"Our chef has made a really tasty and creative dish out of our tiny rations!\"",
" Leo Tolstoy:\n\nHappy families are all alike; every unhappy family is unhappy in its own way.\n\nI think happiness becomes boring and as humans we crave stimulation. That is why /r/happy and /r/greenflags are so deserted.\n\nWould anyone watch plays or Tv if it was about everyone getting along? Any show more evolved than the Teletubbies requires some sort of drama."
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3hu4qj | what effects do animals that become extinct have on the world? | Is it just a matter of overpopulation of another species? What reasons are there to conserve endangered species such as Rhinos? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3hu4qj/eli5_what_effects_do_animals_that_become_extinct/ | {
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"Some species may be a keystone species. This means they have a great influence on other species in their habitat. In Yellowstone the decline in the number of gray wolves lead to an increase in the number of elk which lead to a lot of the wildlife being destroyed by a uncontrolled population of elk. Also without wolves killing the elk scavenger species also started to die off.\n\nFor animals such as pandas they don't contribute much but people really like them so we try to keep them around for our own benefit. \n",
"Coal miners carried canaries into the mines with them. The canaries sang. Canaries needed good clean air. If the canary fell over it was a warning to the miners that the air was not good.\n\nIf a species of animal was doing well in the world, then it is not, it is a warning to us that our environment is not as good as it was. ",
"Many of the major breakthroughs in fields like medicine in recent years have come from us examining the proteins that make plants and animals. A protein extracted from some deep sea fish can have huge benefits in say Alzheimer's or cancer research. We just can't make them like they do in nature. It's like having a library full of unread books, and every year we're just setting a bunch of them on fire. So, we should at least keep a few copies so we don't lose them altogether.",
"**How do species become endangered?**\n\nMost of the time its because of something humans did. Very few species are going extinct due to natural causes nowadays (e.g. volcanic event, being out competed by another species, overpopulation). Most species are going extinct because of (in no particular order):\n\n* Over-hunting and over-fishing\n\n* Illegal hunting\n\n* Live capture for the illegal pet-trade\n\n* Pollution\n\n* Habitat destruction (e.g. logging, slash-and-burn, intensive agriculture, over-exploitation)\n\n* Invasive species\n\n* Climate change\n\n**How do we protect endangered species?**\n\nThere are many ways to protect an endangered species. What most people don't realize is that sometimes the most effective way to protect and endangered species is to do so indirectly. In in some cases it might be better to protect a relatively healthy species that requires a large territory. In so doing we protect all the other species that occupy that territory, including the endangered ones. For example, we might have an endangered migratory bird that requires protection. It doesn't get much attention or funding because it is so small, and perhaps even ugly. So instead, conservationists protect the bear that occupies that habitat. Bears require a lot of space, and by protecting the bear they protect the bird. These are called [*umbrella species*](_URL_3_) because if we protect them, we can protect a lot of other species at the same time. \n\nFor example, Panda bears might be thought of as an umbrella species. They might seem like an evolutionary dead end, and perhaps they are, but because they are cute and so easy for humans to become attached too they become excellent ambassadors for all the other species in their habitat that are also facing extinction. Protecting the Panda protects everything the Panda bear needs to survive - which is a healthy functioning habitat.\n\n**Why protect endangered species?**\n\nWe protect endangered species because current extinctions are not caused by natural forces (e.g. competition, natural disaster). Most extinctions can be traced back to human causes (e.g. overhunting, pollution, illegal trade). We are the problem, we can be the solution. \n\nA healthy ecosystem is an ecosystem we can exploit for future human use. Be it wood, or a medicinal cure, or food, or some other reason - we require ecosystems in order to be able to survive on this planet. We make a lot of money from ecosystems, and in turn ecosystems provide us with many life giving services *for free*, like cleaning our water, or purifying our air. The cost of these services, should we try to provide them to ourselves, would be astronomical. Thus it is in our best interest to insure that ecosystems remain healthy and functioning. Sometimes we only know how important a species is to the functioning of its ecosystem when they are already gone, when it is already too late. So it is in our best interest to preserve ecosystems as they are - in a functioning state.\n\nWithin a functioning ecosystem all things are linked. If you start breaking the links in the food web and you start removing species it weakens the whole ecosystem. There isn't an ecosystem on this planet that humans don't use in some respect for our own gain, so all ecosystems are important to us and our survival. We need healthy functioning ecosystems in order to be able to live and thrive on this planet. An extinct species here and there might not make a big difference (e.g. rhinos), but we are not talking about one or two species. Were talking about thousands and thousands of species, from all ecosystems and all kinds of life. We aren't just messing around with a few links, we are systematically working away at the very foundations that are keeping our ecosystems running in such a way that they benefit ourselves. This is why it is so important to save even just one species - because usually you aren't just saving that one, you are saving many that are linked to it. In so doing you protect the whole ecosystem and its ability to function and provide us with goods and services.\n\nI find that this is a pretty good analogy: ecosystems are like a spider's web. Each silken thread is a different species. Some threads are more important, for example the four or five threads that secure the web to the branches. If these threads are cut, the whole web just falls right apart, instantly. No cushion, no fall back. Gone. Some species act like those threads. They hold the whole thing up - they are that important. We call these species [keystone species](_URL_1_). A very good example are [Atlantic Cod](_URL_5_). Back in the early 90's we nearly fished out all the Atlantic Cod. We destroyed the ecosystem and as a consequence the fishery collapsed. We finally decided to put a moratorium on fishing, hoping that the fish stocks would recover and with it the local fishing economy. It hasn't, it very likely won't. Why? Because the cod were the keystone species, and without them the ecosystem changed forever and it won't go back. One species going functionally extinct lost us millions of dollars and thousands of jobs. Ok, but those are the keystone species...if we protect them then we are ok right? Unlikely because we often don't know what the keystone species is until its too late. By then it is really hard for us to help the ecosystem recover. However, sometimes we can reverse things - [sea otters](_URL_4_) are a great example of a keystone species nearly hunted to extinction that are finally on the road to recovery. \n\nThe second issue is that we can still destroy the spiders web even if we save the key anchor threads. In other words, an ecosystem can still be in a lot of trouble, even if we place a lot of effort on protect key species. This is because the other threads, while perhaps not as important, all help stabilize and give the web and give it its shape and function. Loose one or two threads, no big deal the web can still function. But loose 10%? 50%? 80%? of the threads and now you begin to have a serious problem. The web looses its function, and collapses. The same with ecosystems. At what point do we say enough is enough...10% species loss? 50%? 80%? Resilient ecosystems are healthy ecosystems with a full compliment of species, and healthy ecosystems make us money. A dysfunctional, unhealthy ecosystem is of no use to us in the long term. It isn't sustainable for us, or for the animals that live there.\n\n**Major extinction events**\n\nThe Earth has seen between 70-95% of species lost in past [major extinction events](_URL_6_). There have been a total of 5 major extinction events in the Earth's history. These are usually caused by a myriad of factors (asteroids, sustained volcanic activity) but the main result is that they were catastrophic. \n\nBy all accounts, humans are now in the midst of a [6th major extinction](_URL_2_). Only the culprit this time isn't an asteroid or a volcano, its human activities. We are causing rates of extinction to be much much higher than the expected background rates. For example, on average [1 species of mammal is expected to go extinct every million years](_URL_0_). We are currently experiencing rates that are 10x as high as this. The causes are almost always traced back to humans (over-hunting, pollution, habitat destruction...).\n\nI think it is very hard for us to conceptualize just how bad its getting, just how many species are at risk of extinction, how many ecosystems are on the brink of collapse. A world with 70-90% species loss is a world I do not want to experience, it is a world I do not want my children to experience. We are going down this path, a path that leads to an existence wherein it is just us, our domestic animals (cows, pigs, dogs, sheep, cats, chickens), our domestic plants (e.g. corn, wheat, rice), and likely the species we consider \"pests\" (e.g. crows, rats, mice, raccoons, pigeons, insects). Maybe this just seems like the ravings of a lunatic, how could we possibly experience 70-90% species loss? how could it possibly be *our* fault? The signs are there, the evidence is mounting - we have time to change this around. We have a lot of positive examples, and I think we need to see what we did right in those cases in order to live sustainably on this planet with all the other species."
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4f8dtw | how are buses run to generally be on time despite traffic, varying numbers of stops, and people being slow to get on or off? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4f8dtw/eli5how_are_buses_run_to_generally_be_on_time/ | {
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"They estimate based on the location and time how much traffic there will be and how many riders there will be. A few stops will be \"layover\" stops where the bus won't leave until the scheduled time, which allows it to re-synchronize with the schedule if its running ahead. And if it's routinely late, they'll just revise the schedule to match how it actually runs.",
"Because while day to day things may vary a little bit, they base the routes, stop times, etc on averages. Bus X will take Y minutes to drive this route with normal traffic patterns at this time of day, so the stops will take approximately Z minutes from one to the next. ",
"Also, bus companies use statistical analysis of actual performance to decide what constitutes \"on time\" in the first place. It's not as if there's anyone else that sets schedules for them. "
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4fhn9m | why does your vision continue to spin even after you stop spinning? | You know, you get in a swivel chair and spin around really fast and then stop but you're vision still seems to "spin"? Is my brain catching up or something? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4fhn9m/eli5_why_does_your_vision_continue_to_spin_even/ | {
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"Our sense of balance, motion, and direction come from what's called the vestibular system, which is located in our inner ears. Part of this system is 3 small tubules filled with fluid. When when move or spin or change directions, this fluid moves as well, and our brain interprets those signals to determine our orientation and acceleration, sort of like a gyroscope.\n\nWhen we spin real fast, that fluid in the tubules spins too, and when we stop suddenly, it takes a few seconds for the fluid to stop. Think of it like stirring a cup of coffee. Even after you stop stirring, it takes a few seconds for the coffee to stop swirling and come to a stop. The same thing happens in our vestibular system. Our eyes see us motionless, but our vestibular system tells us we're still spinning, so it causes momentary dizziness until balance in restored.",
"Fluid in your ears sense motion and tell the brain we are moving. This fluid is very viscous. Even though we stop, the fluid is still pushed to one side which is perceived as motion. \n\nSo our brain still thinks we are moving and tries to compensate. ",
"I read an article years ago that explained how scientists wore masks with lens that inverted vision for 24/7. After a certain number of days they removed the masks and their natural vision had Also inverted into an upside down view. After a while the brain readjusted into regular normal vision."
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9abhd6 | what are twitter bots and why are they often associated with trolls? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9abhd6/eli5_what_are_twitter_bots_and_why_are_they_often/ | {
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"Given that this question could be seen as dealing with current events, I'll direct you to r/outoftheloop. I hope you find your answer!",
"Twitter bots are computer programs which are able to tweet the exact same comment in a matter of seconds of each other.\n\nSome bots are useful. weather and news stations can use them to quickly put out their info to all their platforms' accounts at once to make sure the information is exactly the same\n\nTrolls use bots that impersonate real people, making it seem like the opinion the bot is spouting is shared by multiple different people and is more popular than it actually is."
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64qm9t | two constitutional rights. the right to vote and bare arms. why is requiring an id to vote discrimination but same rules don't apply to guns? | Looking more for a legal answer than opinion. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/64qm9t/eli5_two_constitutional_rights_the_right_to_vote/ | {
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"Well, voter ID laws exist. People have a problem with them because they are (allegedly) discriminatory, not because they're unconstitutional.\n\nBut it's really a matter of priorities. We want as many people to vote as possible. We don't necessarily want as many people to own guns as possible. Courts have ruled many times that the Second Amendment is not a blanket protection to completely unfettered gun ownership, and that states have the right to regulate their sale.",
"The second amendment has been treated as the red-headed step child of the Bill of Rights to many gun control advocates who do not give it the same respect as our other rights. The argument is that guns are dangerous and therefore require additional levels of regulation than is required for other rights in the Bill of Rights.\n\nTo answer your question as to why you can require an ID to buy a gun, but not vote, the answer is largely hypocrisy. Forcing someone to present ID prior to using their right to vote is considered by many to be an undue hardship to exercise a basic right. The common argument is that minorities are less likely to have an ID and therefore it is discriminatory, that same argument is not made to exercise their 2nd amendment rights because quite frankly it's kinda hypocritical. ",
"The right to own a gun is a highly contested \"right\" that some people argue they should have (but generally against other people having), and others say presents a clear and quantifiable danger that needs to be restricted for the good of the people, and often imposes legal requirements that give preference to those with experience, such as police or those with a militia. \n\nThe right to vote is a critical part of any democracy and comes down to the right of self-realization, or the ability to make decisions for oneself. People who want to limit the right to vote want to do so to harm certain groups, based on the ideal that they shouldn't have the right to make those decisions. This is done based on things like race or poverty, which is in the constitution that you can't limit. ",
"Presser v. Illinois, 116 U.S. 252, 264-65 (1886)\nthe right of the people to keep and bear arms \"is not a right granted by the constitution. Neither is it in any manner dependent upon that instrument for its existence. The second amendment declares that it shall not be infringed, but this, as has been seen, means no more than that it shall not be infringed by congress. This is one of the amendments that has no other effect than to restrict the powers of the national government . . . .\" \n\nThe Supreme court is consistent over that.\n\nThe second amendment shall not be infringed by congress. For the right to vote, the congress need to protect that right, so they can and are obligated to pass law that protect the right to vote and the state, city, etc need to follow the federal law and protect that right too. But in the constitution, it doesn't say that the congress shall protect the right to bear arms, only that it can't infringed on it. State law can limit the right to bear arms according to the US supreme courts. It's a bit more complicated than that, but that's the constitutional basis for the legality of ID for weapons, but not for voting.",
"There is no constitutional right to vote for president in the US. This has been upheld by the SCOTUS. The only federal right to vote is for representatives in the House of Representatives, and the right to vote for Senators was added by the 17th amendment in the 1920s. There is a constitutional right to bear arms though; 2nd amendment. Democrats don't want IDs required because they claim it makes it harder to vote, yet they require IDs to enter their convention. They want to keep it easier to cheat. Vote early and vote often..."
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6poqr6 | how does our immune system decide what substances it should produce antibodies for? | I've been reading about red meat allergy from lone star ticks (on wikipedia) and read that the cause was supposedly from a substance from most mammals called alpha-gal entering the bloodstream and our body producing antibodies. These antibodies in turn make us allergic to alpha-gal when we eat it in our food.
I've gotten lemon juice in a cut before and I'm not allergic to lemons, so what makes our body decide to produce antibodies against specific substances in our bloodstream? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6poqr6/eli5_how_does_our_immune_system_decide_what/ | {
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"Your body makes antibodies completely randomly.\n\nImagine a child playing with some building blocks. Each B-Cell builds a little tower of blocks by randomly rearranging a special part of it's DNA when it develops. If the antibody it's made sticks to something that's \"self\", then it gets the message to stop making antibodies, and the cell dies and gets recycled.\n\nThe BCells which don't react to self then merrily wander around your bloodstream brandishing their antibody and seeing if it sticks to anything. If it finds something it sticks to, it goes to the spleen and asks around to see if any T-Cells think the thing it sticks to is foreign. If it gets the signal that it is, then the BCell reproduces a lot, and each child BCell randomly tweaks it's antibody blueprint by randomly mutating it's DNA.\n\nThese child BCells then compete to see who's antibody binds the thing they'be found best, and the process repeats until you've evolved a really good antibody which binds strongly to it.\n\nIf you get alpha-gal in your blood, you may or may not have a BCell who happens to have made an antibody which binds to it. The building blocks the BCells use to make their antibodies are inherited, so if you have a building block which already nearly binds the alpha-gal, you'll be more likely to have a BCell make an antibody against it than someone who doesn't have that building block.\n\nIf the BCell gets given the right messages from the T, it can decided that the thing it's killing is a *serious* threat. Then it does a process called *class switching* where it keeps the same antibody building blocks, but essentially sticks a landmine on the end. This is now an IgE antibody. The BCell will then produce this in large volumes, and the surrounding tissue cells will take it up and coat their surface with it. When the target approaches one of these cells, the IgE antibody will bind to it and trigger the land mine, creating a lot of inflammation and damage. This is what causes serious allergies to produce lots of swelling, and is naturally used to kill large, multi-cellular invaders such as parasitic worms. This is your bodies equivalent of \"kill it with fire.\""
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2ox4i5 | how are eulas legal in the united states if you can't return the software after you've "purchased" it? | Isn't that essentially forcing you to obey some of the conditions of a contract (the part about you paying money) without the other party having to obey any conditions (such as letting you use the software)? Are there two separate contracts at work here, such that the first contract involves you paying for the privilege to read and sign the second contract? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ox4i5/eli5_how_are_eulas_legal_in_the_united_states_if/ | {
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"I'm gonna answer this in a way that you don't want to hear, but its really the correct answer as of now:\n\nEULAs are problematic for the courts. There have not really been enough cases or strong decisions in either way to make it clear what the precedent or legality of them are and what is and isn't legal.\n\nCourts know they are written by a team of lawyers and no one, even other lawyers can fully understand them. Yet they are written in a legal manner. They also know that no one reads them, and even if you did, you wouldn't understand it, because it is written so you can't. Also there are tons of clauses and issues which are legal because you agree to them, but are crazy, restrictive and may go against various laws.\n\nCourts have ruled vary narrowly, and on only specific cases so far, so there really isn't a general rule yet. Until then, they will continue to be enforced because there really isn't anything saying otherwise. It's a tough situation for everyone.\n\ntl;dr: Courts haven't made them illegal yet, they are confused too, but its an issue that will need to be addressed and everyone knows it."
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kgpdx | why don't the great pyramids of giza have foundation problems? | Sand doesn't seem like a good choice.. Am I missing something obvious? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/kgpdx/why_dont_the_great_pyramids_of_giza_have/ | {
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"They actually sit on the bedrock.\n",
"It's hard to see in online photos, but they went to bedrock and removed quite a bit of rock in order to level the site.\n\nThere is a lot of engineering in those. It takes more ingenuity to make a pile of rocks that won't fall over than you'd think.\n",
"They actually sit on the bedrock.\n",
"It's hard to see in online photos, but they went to bedrock and removed quite a bit of rock in order to level the site.\n\nThere is a lot of engineering in those. It takes more ingenuity to make a pile of rocks that won't fall over than you'd think.\n"
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6dyilk | why do some religions restrict specific foods? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6dyilk/eli5_why_do_some_religions_restrict_specific_foods/ | {
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"There are proper scientific/historic reasonings as to why some religions restrict particular foods. \n\nJainism restricts garlic and onion because those foods are said to 'heat up' your body\n\nIt has been speculated that a reason to ban pig meat in Islam Is because pigs live in unhygienic environments which promote the growth of mosquitos and disease-causing germs \n\n",
"The parasite answer is one you might hear frequently offered, but not only is this pure speculation, it is very flawed, incredibly reductive and highly insufficient as an answer.\n\n**TLDR--they thought God told them too and we have no idea. But 'parasites' does't come close to explaining it.**\n\nFor example, let's consider \"Kosher\" for a moment:\nI remember being told flat out in a microbiology lecture that Jews don't eat pork because someone got trichinosis thousands of years ago and they've been freaking about it ever since. But this is kind of nonsensical when you think about it. There is nothing special about \"pork\" in Judaism--\"kosher\" land animals require two things. They must have split hooves *and* chew their cud. Pigs have 1 but not the other but they aren't any less \"kosher\" than eating a dog. Or an elephant. Or a crocodile. Or a snake. Or a monkey. Fish on the other hand must have fins and scales (no sharks, catfish or shellfish). For birds there are certain species which are expressly prohibited.\n\nThen you have to keep in mind in order to be kosher, the animal has to be slaughtered in a certain way. The meat has to be prepared in a certain way. Even then, only specific parts of a kosher animal are kosher. Beyond that, you can't mix meat and milk. Plus beef is totally kosher and has all sorts of parasites. Chicken has plenty of associated bacteria, too. In addition, this take requires an assumption that primitive peoples made the connection between eating pork one day and having clinical signs of worm infestation weeks/months later instead of attributing it to ...believing you were receiving some sort of divine punishment for some completely different action. (And remember, lots of people would eat pork just fine without contracting a parasite).\n\nIn either case, if dietary laws were as simple as, \"don't eat pork or devil worms might come out in your poop,\" then parasites would be a really good guess. However, considering that the parasite explanation doesn't plausibly explain much outside of pigs, which is just 1 example out of *many* it doesn't seem very credible.\n\nWhat seems far more likely to me is someone, who didn't know about the complexities of religious dietary laws, said \"Hey, Jews and Muslims don't eat pork. Pork sometimes has parasites. Maybe that's why.\" And that's the answer people have been going with ever since. If that's the case it doesn't make much sense to say 'parasites' as opposed to 'pigs take mudbaths and make ugly snorting noises.'\n\nFinally, religious customs evolve over time and while people often come up with reasons to justify why they do the things they do which aren't necessarily why those customs started in the first place. The answer is **because they thought God told them to**and that's likely to be as good as it's gonna get. \n\n\n\n"
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8jiauk | what's the difference between the meat at the butcher's counter and the meat next to it that's pre-packaged? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8jiauk/eli5whats_the_difference_between_the_meat_at_the/ | {
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"One is cut from larger primal cuts at a factory to whatever specs the factory and/or the buyer wants. An in-store butcher might cut a primal to the size/cut you want. \n\nBeyond that, the differences are specific to that butcher and/or meat processor.",
"Unless you want some custom work, like getting something sliced extra thin, it's all the same stuff and comes from the same place. \n\nSometimes there might be weird quirks of pricing where, for example, you can get a single chicken breast from the counter at the \"value pack\" price or something weird like that.\n\nThe main reasons to go to the counter are:\n\n1. some of their semi-prepared/marinaded stuff is pretty good and a great time saver\n2. You want an odd quantity or a very specific weight of something loose (like exactly 14oz of sausage)\n3. You want to make a custom order ahead of time, like reserving a 12 pound prime rib roast.\n4. You want some specialty/premium product that they only sell behind the counter (fancy bacon, premium aged steaks, etc).",
"It’s usually the same stuff... they may portion out in common sizes for grab-and-go (ie. 1lb of ground beef, 4 steaks) while the butcher counter let’s you get custom amounts. "
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ajpf6h | why is a tetanus shot required for a deep puncture wound, but not scratches that still draw blood? | Holy crap this blew up! Also, thank you for the silver. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ajpf6h/eli5_why_is_a_tetanus_shot_required_for_a_deep/ | {
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"The Tetanus bacteria can get washed off on superficial wounds. But a deep wound even if properly wash can still have remaining spores and you tetanus. . ",
"Tetanus-causing bacteria (Clostridium tetani) are *anaerobic*. Oxygen actually kills them, they can only live in places with little or no oxygen, like a deep wound, but not a shallow one.",
"Have you ever noticed that when you step on a nail it’s usually healed over by the end of the day? That’s exactly what clostridium tetani likes. It needs a warm, anaerobic environment and what is better to provide that than a deep hole that heals over quickly?",
"Ok unrelated question. I haven't had my tentnus shot in like 20 years. Is this a problem? I really don't hear to many people talking about it.\n\nedit: thanks for the responses, sounds like I need to get one asap!\n\nedit: probably not asap but next time I go to the doctor. ",
"There's something other people haven't mentioned here at play and that's the nature of the would too.\n\nScratches and cuts bleed, that's the bodies second line of defense (skin being #1). You bleed out, this actually helps push stuff out, it forms a clot and scab blocking new contaminates. \n\nPuncture wounds often times don't bleed out. So everything that goes in, stays in, and this is a problem. Cut's that don't bleed are actually a problem too but this is uncommon, more for deep puncture wounds.",
"Tetanus is a bacteria that can be found on ANY dirty surfaces. It’s a common misconception that it could only be found on rust. It’s another misconception that the rust itself causes tetanus. It doesn’t. The bacteria can only survive in places with no oxygen. If you have a deep wound, there is little to no oxygen deep inside your body. If it’s a surface cut, that cut is much more exposed to oxygen.",
"No not Necessarily it’s a Clostridium genus. Those are very slow growing and hard to kill that’s why. We vaccinate for them. ",
"Tetanus causing bacteria are everywhere. They can survive on a surface for awhile, but really need an oxygen free area with a food supply to live. When you step on a nail, the bacteria that is on your skin gets pushed inside your foot, thus creating an environment that the bacteria can survive and reproduce. When you scratch yourself, the bacteria isn’t pushed into the skin. It doesn’t have to be rusty or metal, these are just the most common occasions of puncture wounds. If you haven’t hat your tetanus shot in a few years and step on a rusty nail, go to the emergency room and get one right away",
"And why the hell does it hurt so much the next day?",
"New research, published in an infectious disease journal, indicates that the 10-year timeline might be unnecessary. \n\nMy more personal experience: I recently had titers drawn to see if I needed boosters prior to my new job (I'm a nurse). Despite not having had tetanus in 15 years, and only getting 2 Hepatitis B shots approximately 10 years ago. I was sufficiently immune to both. \n\n_URL_0_",
"Tetanus is a bacteria that only grows in oxygen poor environments such as inside it wound . Please correct me if I'm wrong ",
"So can a puncture wound from a non-rusty nail give you tetanus?",
"bleeding itself is a defense mechanism to push foreign particles out of the body. Penetrating wounds have the potential to insert themselves into the blood stream directly."
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84ro7i | i've seen dates expressed as both b.c/a.d and b.c.e/c.e, if a.d is the year jesus was born, what year b.c or a.d did b.c.e switch to c.e? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/84ro7i/eli5_ive_seen_dates_expressed_as_both_bcad_and/ | {
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"The year of the switch is the same in both naming conventions. It is just a shifting from a religious connotation with \"Anno Domini\" to a secular connotation with \"Common Era\". ",
"BC/AD and BCE/CE are the same thing. The common era version was created as a secular version.",
"Because BC (Before Christ) and AD (Anno Domini, or 'In the Year of Our Lord') have specific religious connotations, specifically with Christianity, more and more countries and their educational institutions have, for official and scholarly purposes, started replacing the more traditional abbreviations with BCE (Before Common Era) and CE (Common Era). The actual dates are the same; Year 50 is still Year 50 regardless of whether you express it as 50 AD or 50 CE.\n\nThe actual abbreviations BCE/CE have been around for a couple hundred years, since at least the 1800s, and was regularly used in texts written and consumed primarily by non-Christians (the use of the BCE/CE system was particularly popular in the Jewish community, which for obvious reasons did not want to use nomenclature referring to Jesus as \"Our Lord\"). However, with the rise of large-scale globalization and the integration of scholarship over the past 75-100 years or so, the term has become *much* more common. England and Wales introduced the CE/BCE system into the official school curriculum in 2002, and Australia followed in 2011. More and more textbooks in the United States also use CE/BCE, as well as history tests issued by the US College Board. As far as I'm aware, there's no law mandating the change in the US, but most social science and classics classes now refer to dates using the BCE/CE system rather than the BC/AD system out of a) the growing secular nature of society, b) a desire to have a more \"impartial academic\" approach to history rather than a religious-based one, and c) general respect for non-Christian religious traditions.\n\nSidenote: the use of BC/AD didn't begin to catch on until the late 6th century and wasn't even standardized until around the 7th century when Charlemagne adopted it as the official calendar expression for the Holy Roman Empire."
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57adfg | why are liberal and conservative ideologies named what they are? | To a degree I understand why liberal ideology is called 'liberal', although the priority doesn't seem entirely 'liberating' from a regulatory standpoint, but why is conservative ideology called 'conservative'? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/57adfg/eli5_why_are_liberal_and_conservative_ideologies/ | {
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"Because they want to conserve the traditional social and political institutions. \n\n_URL_0_\n\n > Conservatism as a political and social philosophy promotes retaining traditional social institutions in the context of culture and civilization. Some conservatives seek to preserve things as they are, emphasizing stability and continuity, while others, called reactionaries, oppose modernism and seek a return to \"the way things were\".[1][2] The first established use of the term in a political context originated with François-René de Chateaubriand in 1818,[3] during the period of Bourbon restoration that sought to roll back the policies of the French Revolution. The term, historically associated with right-wing politics, has since been used to describe a wide range of views.\n\n",
"All you have to do is look at the definition of the words.\n\n* Liberal - open to new behavior or opinions and willing to discard traditional values.\n* Conservative - holding to traditional attitudes and values and cautious about change or innovation, typically in relation to politics or religion.",
"A liberal party is not liberal as in liberating people. A good analogy is spreading jam on toast. If you are being liberal with your use of the jam, you are using rather large amount. If you are spreading your jam conservatively, you are using very little. Now imagine the jam as new ideas and the toast as society. A liberal politician is willing to implement a variety of measures that have ideas that may not be the norm. A conservative politician uses very little of these ideas, and prefers traditional values, leaving society (the toast) more or less unchanged."
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3y76z3 | how do closed captioning systems work for movies? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3y76z3/eli5_how_do_closed_captioning_systems_work_for/ | {
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"I don't know how the system works per se, but I did just have my 1st experience using it. It was an independent device that fits in the cup holder. You can then twist and bend the stalk part so that the box part that displays the text is in front of you. Sometimes it would miss the 1st part of dialogue so it wasn't perfect, but it did help a lot.\nIt is the far right pic on this page showing the devices _URL_1_\n\nHere is another picture\n_URL_0_\n\nIt uses wireless technology I'm sure because it does not do anything but fit into a cupholder (no wires). I did a bit of reading and it seems there are different devices. One mention of glasses was used. We saw Star Wars 3d, so between my glasses, and the 3D glass ver them, I can't imagine glasses for CC would have worked for me. ",
"There are multiple systems. I've had the grace (and misfortune) to use three different systems.\n\nOne system is a large set of glasses ([like so](_URL_0_)) that you wear that is hooked up to a small box that has the wireless technology, controls, and battery. The words appear on the lenses and it does work rather nicely. The big cons are every theater I go to seems to have multiple faulty units and the glasses are heavy and hurt your nose by the time the movie is over. They look silly as well but I don't care much.\n\nAnother system is the [CaptiView](_URL_1_) which rests in your cupholder and has an LED screen that is protected by blinds so the light from the text doesn't disturb anyone else. This is my least favorite of the three. Sometimes it will be missing a line or two of dialogue. The stand is very ackward to set up. I've had faulty units before. The worst part in my opinion is how you have to refocus your eyes in order to switch between the screen (which is a distance away) and the device (which is right in front of you) and breaks immersion.\n\nMy personal favorite is the [Rear Window system](_URL_1_). You are given a small slightly tinted piece of plastic attached to a stand that rests in your cup holder like the previous system does. At the back of the theater there will be a marquee board that will display the dialogue except inverted like it would be if you looked at text in a mirror! You have to angle the plastic so that you can see the reflection of the words and thanks to physics the reflection you see is inverted back to being normal. The downsides of this system are that it takes more effort for the theater to install (they have to put that marquee board up in the theater versus just putting a wireless unit in the projection room). You also are limited in where you can sit within the theater because usually the board will be on one side of the theater rather than in the middle. The positive sides are that you can control where the captions appear in your view, if you want them in the middle of the screen go ahead or maybe at the bottom or the side, whatever. The plastic stand also does not need to be charged so there's no chance of a faulty stand (other than the pieces holding it together loosening but that can be fixed by tightening). I really wish every theater had this system in it."
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"http://www.doremilabs.com/products/cinema-products-2/captiview/"
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6r9zm3 | why are plasma and blood donated separately?? | I was reading about donating plasma and it said that your blood was circulated back into your body after the plasma was filtered out. Why not just take both?? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6r9zm3/eli5_why_are_plasma_and_blood_donated_separately/ | {
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"Whole blood donation does just that. However, generally plasma is of lesser value for transfusions, and anyone collecting plasma for the plasma doesn't care too much about anything but the plasma, so the rest is filtered and recirculated.\n\n\nOn the other hand, some blood donation agencies offer red blood cell or platelet-only donations. For those with high-demand blood types, RBC-heavy donations offer greater benefits to the community with less frequent donators. ",
"So the idea is that there are people who don't need blood, but do need plasma like burn victims. In those cases, they need the plasma right then and don't have time to run it through a centrifuge to separate it. "
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1vqeud | if i overcook chicken by boiling, why does it become dry? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vqeud/eli5_if_i_overcook_chicken_by_boiling_why_does_it/ | {
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"So, the proteins in the raw chicken are kinda loose and sitting around with moisture in them like sponges. When you heat up the proteins, they squeeze together and expel all the water. \n\nThis article explains this an mentions that chicken should be poached instead of boiled. \n\n_URL_0_"
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ahjb1o | gaming pc parts and what they do | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ahjb1o/eli5_gaming_pc_parts_and_what_they_do/ | {
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"Questions like this are better in r/buildapc or r/techsupport.",
"Here are the necessary parts of a computer:\n\n* CPU - also known as the processor. Basically the brains of the computer.\n\n* Motherboard - a circuit card that enables connectivity between the CPU and all other components of the computer. Many of them have integrated audio chips, Ethernet/WiFi cards, or even GPU. Gaming motherboards may or may not have an integrated GPU. Your USB ports also reside on the motherboard.\n\n* GPU - also known as graphics card. This is what handles the processing and rendering of visuals that go to the montior.\n\n* RAM - short for Random-Access Memory. The easiest way to think of RAM is as a dry-erase board for your processor. Information is written to RAM and overwritten when no longer needed.\n\n* HDD/SSD - Hard Drive Disk or Solid State Drive. A Hard Drive Disk uses a series of platters to store information long-term. A Solid State Drive uses flash memory for the same purpose. A common practice these days is to have a small (128 or 256 GB) SSD for the Operating System, and a 1 TB or larger HDD.\n\n* Optical Drive - DVD or BluRay drive.\n\n* NIC - Network Interface Card. If you use a dedicated NIC as opposed to an integrated NIC, you'll have an additional Ethernet or WiFi card. In many cases, dedicated vs integrated NIC is a personal preference, but may be necessary if the integrated NIC fails.\n\n* Audio card - an optional component if you feel that the audio capabilities that are integrated into the motherboard are inadequate.\n\n* Power Supply - provides power to the computer.\n\n* Case - (kind of obviously) holds the components of the PC.\n\nIn addition to these, you'll need cables to connect certain components - SATA cables for the HDD/SSD and Optical drive, power cables from the Power Supply to some of the major components. The power supply should have the power cables included, but depending on your setup, you might have to use extension cables. You'll also need a cable from your computer to the wall outlet and from the computer to the monitor. Additionally, you may need to purchase cooling for the CPU, but you can often find bundles of the CPU and cooling, also known as the heatsink, together. There's also, obviously, the keyboard and mouse.\n\nIf you have any futher questions, feel free to let me know!"
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8m5c5n | why shaking my head left and right , remove or lower feeling of dizziness ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8m5c5n/eli5_why_shaking_my_head_left_and_right_remove_or/ | {
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"Your inner ear has water in it. If you are dizzy it's because the water is moving and you are not. When that is happening shaking your head to and fro ends up moving the water against its current flow. Since the water inside your inner ear is moving less than before, you become less dizzy. "
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1kl7x3 | how are mah (and amps in general) and voltage related in terms of batteries? | For instance in laptops, phones, toys and such. Specifically I guess i mean if you have higher voltage, does that affect how much the mAh is "worth"? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1kl7x3/eli5_how_are_mah_and_amps_in_general_and_voltage/ | {
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"A milli-amp hour is how many milli-amps are drawn down in one hour. If a battery is rated at 2400 mAh and the device it is connected to draws a steady 100 milli-amps per hour, the battery will drain in 24 hours under ideal conditions.\n\nThe rated voltage of the battery is based on engineering specs and isn't really related to mAh for the purposes of this discussion.\n\n...But, since a \"battery\" is technically several cells that are soldered together, you could add a cell, which would raise the voltage and the mAh rating, but it wouldn't work in the device, so it's a moot point.\n\nEdit- It occurs to me that the question of batteries with different mAh ratings for the same device, like a high capacity battery for your cell phone, may come up. Less internal resistance due to better manufacturing materials and/or processes. Ohm's law. Voltage = Current (amps) x Resistance. If voltage stays the same, but current goes up, it must be because resistance came down.",
"You can think of voltage as a measure of electrical \"pressure\". Amperes are a measure of the number of electrons, and voltage is the concentration or \"pressure\" of electrons.\n\nImagine water in a pipe. if you increase the size of the pipe, the \"voltage\" drops and the \"amperage\" stays the same. if you decrease the size of the pipe, the \"voltage\" increases.",
"Current (Amperes) is a measure of the amount of charge is being transmitted every second. Essentially a battery can only store so much charge. Essentially a 5000 mAh battery (this would be amazing quality for a cellphone battery), can transmit at 5 Amperes for 1 hour or 0.5 Amperes for 10 hours.\n\nVoltage is a measure of potential energy in each electron (Voltage is a measure of Joules (Energy) per Coulombe (a unit representing a large number of electrons). If something has a higher voltage, that a single unit of charge has more energy associated with it."
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bdk45k | why is the music industry filled with drug abuse? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bdk45k/eli5_why_is_the_music_industry_filled_with_drug/ | {
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"This is a loaded question\n\nIs the music industry filled with drug abuse compared to other industries? Do you have some metric on this? Actually not music, but there are lots of research on industries as a whole\n\nSure musicians use drugs, so do miners, people working in retail, bankers, teachers, and construction workers.\n\nAccording to [some research](_URL_0_) - the rate of drug use in entertainment & recreation (13.7%) is actually substantially lower than the top one, food service (19.1%).\n\nSo you have to ask yourself, yes drug use is common, but is it out of line, and it may not be, it may just be that you know about it more."
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65eowp | how does the press to test feature work on aa batteries? | On some AA batteries, you can squeeze two points on the battery and it indicates how much juice is left. How does that work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65eowp/eli5_how_does_the_press_to_test_feature_work_on/ | {
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"They use a combination of colour changing and conductive ink. \n\nThe ink is conductive so that when you touch the two points, current can flow. \n\nThe colour change occurs with temperature. \n\nSo what you do is create a gradually widening strip of the colour changing conductive ink. The narrow part takes the least power to warm up and change colour, and as it gets wider, more power is needed. So it's a way of creating a 'fuel gauge' for the power that's left in the battery. The more of the bar that fills up, the more charge the battery has. "
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754ik5 | why do some animals "show off" their babies to humans? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/754ik5/eli5_why_do_some_animals_show_off_their_babies_to/ | {
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"Why do humans \"show off\" their babies to other humans?\n\nAnimals, contrary to some belief, do possess a modicum of intelligence. If the animal believes humans aren't a threat and, especially with animals raised in captivity, a caregiver, they will want to show off their child to one seen as a 'friend'. It's easy to assume, then, that animals are legit going to humans they trust and going \"HEY! LOOK AT MY BABY! ISN'T IT AMAZING?\"",
"Sometimes humans feed wild animals, even though we shouldn't. Sometimes the parents bring their babies for some of that food. I'll quite often see the local baby magpies in my yard because the parents know it is safe, and even animal parents need time away from the kids so they'll ditch them for a little while like leaving your kids at day care, except your kids are month old birds and day care is my yard. ",
"My dog did that lol. She was so proud of her puppies she would literally carry them onto our laps when we were sitting on the couch."
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7dxpig | why does biting aluminum foil feel unpleasant but biting on a metal spoon or fork doesn't? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7dxpig/eli5_why_does_biting_aluminum_foil_feel/ | {
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"Aluminum foil is just the processed and pressed, oxidized element; where as steel is a stable alloy, and other flatware materials, like silver, are much less reactive. Due to the Al being raw-ish, when you bite down the foil, your saliva, and your teeth create a mini battery. \n\nYou may get the same sensation with really cheap or plated silverware, especially if you have metal fillings."
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6lo846 | how are tv ratings a useful measure of an episode's quality if tuning in (i.e. ratings) happens before anyone knows what the episode is about? | Sites that list tv show episode rankings and ratings (i.e. IMDB, Wikipedia, etc) often include a line for TV viewership/audience as an indication of whether an episode was popular. But since you have to *watch* an episode before you can form an opinion, doesn't the size of the audience exist independently from it's subjective quality - or at least, better indicate the quality of the previous episode to get the audience to tune in to the new one? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6lo846/eli5_how_are_tv_ratings_a_useful_measure_of_an/ | {
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"The ratings aren't there to judge the quality of an episode -- that's for critics and the public to decide.\n\nThe purpose of the ratings is to determine how many people are watching it, and the demographics of those people, so that the networks can know how much to charge for advertising in subsequent episodes.\n\nThe advertisers don't really care how \"good\" the show is -- they care how many eyeballs will see their advertising."
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dgb5m4 | why did old tvs have be set on channel 3 if you wanted to play anything linked to it such as a vcr, dvd player, or game console? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dgb5m4/eli5_why_did_old_tvs_have_be_set_on_channel_3_if/ | {
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"The game consoles had a built in “video modulator” that took the video/audio and basically had a miniature tv station transmitter inside them. TVs at the time usually just had an antenna input, they didn’t have countless video input ports like TVs do now. So the only way to get video from your game console was to pretend to be a TV station.",
"The signal frequency of the input. If you go further back, when tv’s had a tuning dial, you could tune your NES into the B/W 12” portable. The console/vic20/whatever output a signal at whatever frequency and your TV picked it up as though it was coming from an aerial.",
"When I was a Kid, we had 2,4 & 7 for NBC, CBS,and ABC. Then we had the Canadian channels3, 5 & 9.",
"There were TVs that were \"cable ready\"and those that weren't. Not being cable ready meant you got channels 2-13 VHF and 14-60 or 80 someodd UHF.\n\nChannel 3/4 was chosen by game mfrs cuz a console with a direct wire feed could drown out any station, plus, channel 3/4 were chosen cuz they were likeliest (from broadcaster's view) to have interference from other tv signals. The FCC had to dance around when assigning tv stations to broadcasters due to other stations in nearby cities, and 3/4 got the most interference, so were least often assigned to actual broadcasters.",
"Today's televisions have all sorts of inputs: HDMI, VGA, DisplayPort, Component, Composite, S-Video, Cable, antenna, and a variety of others. However, back in the early days, nobody had video games, VCR or DVD players, or even cable, so the only connector TVs had was the antenna connection.\n\nSo, when you wanted to have cable, or video games, the only way to feed the signal in was \"broadcast\" it on your own miniature TV station, through a little box called an RF Modulator. They used channel 3 or 4 because those were usually unused for regular broadcasts."
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equgdv | how does therapy work/repair years of low self esteem and feeling worthless? | How does it make people feel better and stop the feeling of hopelessness?
Is it different from just talking to someone? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/equgdv/eli5_how_does_therapy_workrepair_years_of_low/ | {
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"You’re thinking of something called “cognitive behavioural therapy”.\n\nBasically, when you’ve thought you’re a worthless sack of shit for years...your brain has formed certain habits. Your brain is **meant** to form habits (that’s how you learn anything at all) but in this case, the habits you’ve built up over time are negative ones. The way you talk to yourself. The way you respond when something goes wrong. You’ve been doing things in particular ways for so long that this is the only path your brain knows how to take. Every time it happens, you’re so used to following the same pattern that you start doing it again without even noticing.\n\nCBT with a therapist is a process of breaking down your old habits, and training your brain into adopting new, healthier ones. It’s gradual. It takes a while, and at first you **do** find yourself consciously stopping when you notice old habits and going *no, I don’t want to react this way; I’m going to reset and choose THIS instead*\n\nTalking to someone in general can help in some of the same ways that therapy does. But it’s a lot easier to learn and reinforce new habits (they have to be reinforced before they can become automatic) when you’re supported by a therapist who knows exactly what you’re trying to do.",
"In essence a great deal of therapy is designed to \"reprogram\" those thought processes and make you able to function despite them. I'm in therapy and can tell you it is a slow process.",
"Your brain has pathways running through it, the more you use a pathway the nicer your brain builds it because you use it so much. \n\nSo if you imagine a forest, if you keep walking the same way you make a path of footprints, then you use it so much it’s a clear hiking trail. Now you can take this path without thinking because it’s been used so much. You no longer worry about where it leads your brain just guides you. This is great if the path leads to things like brushing your teeth, not greater the path leads to you thinking you’re worthless.\n\nTherapy helps you take a step off those overused paths that lead you where you don’t want to go. At first you have to bushwhack a new trail in your brain but eventually, your positive thoughts will slowly make a new path and your negative path will slowly become overgrown and more difficult to use. It’s awkward at first, but it does get easier if you work at it.",
"Therapy has helped me lots, especially in the last couple of years. (I’m 32) took me 6 tries and 10 years to get a therapist that is productive with me. \nSearch “unhelpful thinking habits”, “thought record”, “assertive formula”, “window of tolerance” they were helpful tools that now make me emotionally regulated.\n\nYou might want to start taking stock of your emotions, and investigating them. Also interesting and helpful to understand, is what we need emotions for. For instance, anger occurs in us when we perceive our boundaries being crossed."
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3e7bv7 | what would happen if a democratic presidential candidate picked a republican vp / vice versa? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3e7bv7/eli5_what_would_happen_if_a_democratic/ | {
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"Other than a lot of drama? Nothing special.\n\nPolitical parties are mostly just a matter of convenience, and don't have any sort of formal standing constitutionally.\n\nThere would be a lot of drama, and the candidate would face opposition from the far left and the far right, but there's not anything special that happens if he picks someone from the other party.",
"Having a President and Vice President from different parties is what sparked the 12th Amendment. Before the 12th Amendment, electors voted for two people. If there was a winner with at least a majority of votes, that person became President. If there wasn't a majority, then the House would choose from the top five winners.\n\nThe Vice President was whoever had the most votes and wasn't selected to be president. The Senate chose in the case of a tie.\n\nThe original plan didn’t anticipate the rise of parties, but parties formed quickly and it resulted in a bit of a mess. In 1796, John Adams won the presidency, but Thomas Jefferson, his political rival from another party, won the vice presidency. In 1800, Jefferson won the presidency and his running mate, Aaron Burr, won the vice presidency, but not after a very messy election in the House of Representatives. Essentially, the system made it very likely that the Vice President would be the defeated political opponent of the President, which made it difficult for them to work together. In 1804 the 12th Amendment was ratified and it set up the presidential voting system we have today.\n\nSo as /u/bl1y said, it's happened before and there's no reason it couldn't happen again, but we have enough political fighting without having the top two members of the executive branch being from different parties. \n\nAlso, the electors don't have to vote for the presidential candidate's choice of running mate. Electors get to cast one vote for President and one for Vice Presidenct. Electors are generally chosen by parties, so if the presidential candidate chose a VP candidate from another party without their party's consent, their party could just ask all the electors to cast their presidential vote for the original candidate and their VP vote for someone else.\n\nEdit: As u/ghengilhar pointed out, Burr ended up winning the VP slot in 1800."
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2qmj5m | how is math universal? would aliens have the same math as us? isn't it just an arbitrary system of calculations? would we be able to communicate with aliens through mathematics? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2qmj5m/eli5_how_is_math_universal_would_aliens_have_the/ | {
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"A good example is Pi. \n \nNo matter what system of measurement you use, the diameter of a circle is going to have a consistent ratio to the perimeter of that same circle. \n \nThat ratio is Pi. \n \nFrom there up, you can do trigonometry through a process called 'from first principles', where each step upward in complexity depends on the previously proven (or accepted) items. \n \nThis process *could* allow us to communicate with alien life, provided that they have the sensory apparatus to perceive the data, and that the presentation of the data itself isn't painful/antagonistic to them.",
"Math describes the physical world pretty accurately. Even if aliens had a different way of writing or thinking about math, and they might very well have exactly that, it would still have to produce the same results our math does.",
"Imagine you had a huge stack of chairs and an empty room.\n\nPlace a chair into the centre of the room and you have \"1\". Place another chair into the centre of the room and you have \"2\" (\"1\" chair + \"1\" chair = \"2\" chairs) Place another, and you have \"3\" (\"2\" chairs + \"1\" chair = \"3\" chairs), and so on.\n\nAs you can see, mathematics is just a language we use to describe real-life situations. In the example above, we used the language of numbers (\"1\", \"2\", + signs, = signs) to describe chairs being placed in the centre of the room. This language can vary (I might use different symbols instead of \"1\", \"2\", and \"3\"), but the fundamental concepts being discussed (chairs being placed in the room), remains universal.\n\n",
"the Symbols of math, i.e. numbers, operation signs, etc, are in no way universal. they aren't going to know what \"1+1=2\" means any more then they are likely to know what \"Hello\" means. they're just a bunch of arbitrary symbols without context.\n\nthe universality of math comes from the fact that certain truths come out of mathematical operations that are necessary consequences of how we came to math, and how we expect aliens would come to math. \n\na good example of this is the sequence of prime numbers. 2,3,5,7,11,13,17,19: \n\nIf you have a thing, then you have one thing (even if you call it \"Zorblat\" thing, or the uniary element, or whatever). you can put another thing and now you have a set of 2 things (or \"Hezmar\" things, or uniary increment, or whatever). your set of two can be cut into 2 parts, and your have two even groups of exactly 1 element in each part. we can call this \"evenly divisible\". \n\nso 2 is evenly divisible by 1 and 2 (2 groups of 1 each or 1 group of 2). add one more and we get 3 things (or \"Ivernasal\" or uniary increment increment, or whatever). 3 is NOT evenly divisible by 2, but it is evenly dividable by 3 and 1. \n\n4 (or \"letgel\") is evenly divisible by 1, 2 and 4, but not 3. every other number so far has only been divisible by itself and 1, but 4 is the first number that is divisible by something else. if we keep this up for a long time, we can see that a lot more numbers are going to be divisible by other things, but some numbers are divisible only by 1 and themselves. so we can start listing them and call the numbers \"prime\" (or Confu numbers, or whatever) if they are only divisible by themselves and 1. \n\nif we list all of those out, we get the set of all Confu numbers, that are only divisible by zorblat and themselves: Hezmar, Ivernasal, upletgel, seebi, etc. etc. \n\nnow if we see some alien signal like this:\n\n.. ... ..... ....... ........... ............. ................. ...................\n\nthen we can count that as 2,3,5,7,11,13,17,19, even if they counted it as Hezmar, Ivernasal, upletgel, etc, and we'll know they can do basic maths to find prime numbers, and we'll know they are intelligent, and not just some quasar spouting random flashes into the night. maybe they send the same sequence again, but this time it's in symbols, not flashes. now we know what some of their numbers are. \n\nactually constructing a language requires building a common context. if you know what the numbers are, you can start connecting numbers to chemicals by talking about the first chemical element (we call it hydrogen, they might call it Max for all we know). elements get you objects, objects get you concepts, concepts get you verbs, verbs get you sentences and bang, you're talking. \n\nit's a very very slow process, and we've never had to do it on earth because we share a common context in how our brain operates, but it could be done to create a language between two cultures that didn't even share that \n\n",
"I think there is no better way to learn about this than to read [the unreasonable effectiveness of mathematics in natural science by wigner](_URL_0_)\n\n > how is math universal ?\n\nthe laws of logic by which math operate are derived from our perception of the natural world. i.e essentially counting, symmetry, geometry, classes, sets. however in a universe where counting or symmetry or geometry or sets does not appear to apply our system of math will fail. as for this universe, they apply throughout the observable universe, so it's perceivably universal (form our point of view atleast).\n\n > would aliens have the same math as us ?\n\n\nassuming they are intelligent and have the same degree of perception and ideas of logic, depends on how advanced they are and how much they have explored the field. but they will have come to the same conclusions. may be their number system might be different but the relationship between the objects in the system would be the same and the operations thereof. i.e something like a+b=c would still hold and be discovered by them.\n\n > Isn't it just an arbitrary system of calculations? \n\nthe laws that make calculations work, are not arbitrary, they are based on a system of logic that governs all math. The set of operators, that do the calculations, may be defined arbitrarily but as per these laws. eg: incrementing a number by a unit number will give us the next number regardless of what system we are using. we ourselves have many systems of counting - binary, decimal, octal, hexadecimal, ~~roman~~ but the concept and the \"law\" of addition, subtraction, multiplication and division hold across all those system. incrementing a number always brings us the next number, regardless of the number system it's applied to.\n\nit could be argued and it should be noted that the system of logic, is sort-of arbitrary, but it stems from our objective perceptive of the universe and what we perceive to be true. but unfortunately there is no way of proving that our system of logic on which all math is built is true from within the system itself. but we have always perceived it to be true, by constantly applying it to the physical world and getting satisfactory results.\n\n > Would we be able to communicate with aliens through mathematics?\n\nif we want to communicate math, logic and facts about the natural world (based on our perception), then probably yes, as long as their system of logic is also the same, that is to say, their perception of the universe is more or less the same. if we want to communicate the humor, poetry, literature, current affairs or small talk then probably not - memes are far more efficient for those :P\n\nShameless plug for good ol' math\n\n\n\n > Mathematics, rightly viewed, possesses not only truth, but supreme beauty, a beauty cold and austere, like that of sculpture, without appeal to any part of our weaker nature, without the gorgeous trappings of painting or music, yet sublimely pure, and capable of a stern perfection such as only the greatest art can show. The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as in poetry. --BERTRAND RUSSELL, Study of Mathematics\n\nEDIT: making the answer as accurate as possible based on feedback.\n",
"Math started out as a very practical field involving *natural numbers*. Natural numbers are numbers that you can count, like 1, 2, 3, 4, etc.\n\nAddition stems naturally from natural numbers - if I have two apples, then I get three more apples, I have 2 + 3 = 5 apples.\n\nSubtraction is just as natural and intuitive. If you have 10 apples then lose 4 apples, you have 10 - 4 = 6 apples.\n\nMultiplication is a bit less intuitive - it's really just kind of shorthand for addition. If you have one group of four apples sitting together, you have 1x4 = 4 apples. But if you have one group of four apples over here, and another group of four apples over there, and another group of four apples over there, you have 4 apples + 4 apples + 4 apples, or four apples, counted three times (4 x 3 = 12).\n\nDivision is even less intuitive but equally as natural. If you have a group of 20 apples and you want to split them up evenly among a group of 5 people, you would have five groups of apples, and count one apple into each group until they're all gone. So you would wind up with 4 + 4 + 4 + 4 + 4 apples, or 20/5 = 4 apples.\n\nLiterally everything else from math springs from those four shortcuts for counting stuff. \n\nSo what I'm getting at is, as long as you can count, you can discover math. So if aliens have eleven tentacles, they may count from one to eleven before adding a second digit, but the basic principles will still hold. They might not use math the same way or get as advanced as we do (or they could be far more advanced), but as long as you have a need to know \"how many,\" you'll wind up developing some system of math.",
"What if the aliens are just a bunch of partying burn outs that wanna make love to our women? Love is the universal language not math. ",
"There is a lot of talk about counting theory and basics of logic but there is a good earth example as to why this would be a good universal language. In the 17th century there was a new Renaissance in mathematics and science. When studying physics, Isaac Netwon developed a new system of mathematics known as calculus. Half a continent away, while studying mathematics, Gottfried Leibniz learning developed the same system independently. Their notations were different but the mechanics of the system were the same because the mechanics of mathematics are a universally consistent. The notations would be different but it's not a stretch to think that the same effect can exist on an interplanetary scale\n\nedit: I'm not close enough to Gottfried Wilheilm Leibniz to just call him Gottfried, as much as I wish i was.",
"Mathematics is universal in the sense that if you assume the same axioms and have the same definitions, you will always get the same results, assuming of course that the proofs are correct.\n\nHowever, an alien race may use a different set of axioms and definitions which vary. For example, they may favor considering 1 a prime number. For the most part, we disregard 1 as a prime number for various reasons, but probably the best one is the fundamental theorem of arithmetic, which says that each positive integer has a unique factorization into a product of powers of primes. If 1 is a prime then this factorization is not unique. However, the aliens may present this theorem with 1 being an exceptional case, i.e. each positive integer has a unique factorization into a product of powers of primes greater than 1. In number theory, 2 is prime but often an exceptional case in certain theorems.\n\nOn a basic level, we could reasonably expect an alien race to reach many of the same basic conclusions. For example, multiplication of two real numbers likely won't be different but even here there may be some room for axiomatic differences, such as dealing with infinity.",
"This might not be the explanation of how fundamental maths is that you were hoping for, but it is worth looking at this from the top down as well. We use Maths as the tool that lets us do science. It allows us to describe our world, and if we ever communicate with aliens, maths will be how we do it. Aliens are describing the same phenomena as us, so undoubtedly they have the same mathematical results to do it with. ",
"There actually isn't a straightforward answer to your question, as the 'universality' of mathematical objects is still the subject of some debate in academia. To give an ELI5 version of this debate:\n\nThere are two main schools of thought about whether or not mathematical objects (integers, sets, etc.) exist independently of human understanding. *Platonism* contends that mathematical objects exist independently of us, and therefore are 'discovered' by the work that mathematicians do. So, in answer to your question, a Platonism would say that there is only one 'math', and provided that the alien mathematicians had done good work, their mathematics would be consistent with ours.\n\nThe other side of the debate is *intuitionism*. Intuitionists believe that a mathematical proposition isn't true (of false) until it's proven as such. The strength of this theory is that is does a better job of explaining how we build mathematical systems, but it doesn't account for how it is that mathematical truths seem to be consistent. So, an intuitionist would argue that, if the alien mathematicians were able to construct different proofs to human mathematicians, then they may have built an entirely different mathematical 'language' entirely. \n\nThis is a huge oversimplification of a more complex (and infinitely fascinating) field of study. Hit me up if you want to know more.\n\nSource: BA degree in philosophy, specialising in maths.",
" > How is math universal? \n\nThis question is pretty vague. Universal how? Math is making logical deductions from assumptions (\"axioms\"). If aliens assumed the same things then they will deduce the same things. Is this what you mean my universal?\n\n > Would aliens have the same math as us?\n\nNot necessarily, if they choose different axioms. However there are things which come very naturally from the axioms we have chosen, that I think aliens would want to use, too (such as counting, addition, etc), so at a basic level it would look very similar.\n\n > Isn't it just an arbitrary system of calculations? \n\nSorry?\n\n > Could we communicate to aliens through math?\n\nNope. You may hear \"math is a language\" but I think that saying is absurd. We have a language to describe mathematics, they may have a different way of describing the same thing. We could possibly explain this mathematical language quicker than a real language, as it is smaller and more logical, but it is only useful for communicating mathematical ideas.",
"[Somewhat related](_URL_0_) image that I got from 4chan years ago. Maybe someone will get a kick out of it.",
"I once read a little story a guy wrote about what the first person who ever meets aliens should do. Basically he said you shouldn't panic, you shouldn't try and fight them. Don't try to communicat with music or language. The first thing you should do is draw some shapes (Geometry) and perform some math problems in front of them, the more complex the better. (I would link story but I'm on a shitty government computator)\n\nI think this is true in a sense, Math is by far one of our greatest achievements. And regardless of how we perform it, something in there should hold some universal significance.",
"How you get an answer can be arbitrary, but the answer is universal (for arithmetic, anyway). 3 beeps is 3 beeps, no matter what name you give 3, for example. ",
"Math is universal as if.\n\nMath is the description of the world\n\nThe ultimate proof of concept is the ability to predict the future. Math does that exceptionally well.\n\nAliens would use math yes. Maybe a different system, with different values, measured from different side with different sizes and priorities. But they would descripe the same thing we do. The reality.\n\nMaybe the number 2 doesn't exist for them. But the concept for the value of 2 will exist.\n\nHence the math would be ultimately same. It would just look and work differently.",
"Kinda. In a nutshell, they would understand the same concepts, were they advanced enough. Most likely they would understand zero, and basic principles if they are intelligent enough, such as the pathagorean theorum etc. It is often said math is \"discovered\".\n\nFibonacci sequences, primes etc. Would be in reach, but nothing guarantees they use a base ten system, for instance.\n\nThere are some interesting basic math concepts shown by Voyager that presumedly aliens could understand.\n\nEdit: enough is not spelled with a w.",
"No way. I was literally just thinking this the other day. Man, I love Reddit. \n\nI came to the conclusion that since math is universal in our society; it's completley possible that ETs use math for the same reasons we do. They could even use the same formulas, and methods to solve their problems. However I do think it's likley that their understanding of mathematics in comparison to ours is much different.\n\nIt would be cool if they happened to use the same symbols for numbers, equations, pi, etc. that we do. It's more than unlikely though. I would love to see what characters they use for numbers and letters. See if they follow the same pattern that ours do.\nI wonder if they have 10 base numbers like we do, or 50 of them.",
"If we accept the concepts and representations of numbers as you and I think about them, then it all works out like everyone else said. However, a few things bear noting.\n\n1. The concept of zero is complex and took many civilizations a long time to create. This makes certain things, like the identity property, not \"work\"/exist. That's kind of a big problem when we start dealing with equality. We definitely want a rule where x+0=x.\n\n2. Not every civilization has natural numbers (1,2,3...) [source](_URL_1_), search one-two-many. Surprisingly, they're social constructions. It's kind of hard to do math without prime numbers, exponents, decimals... If people on Earth don't have them, why would aliens? (ok maybe we assume they did because they reached a certain level of complexity but whatever). We could also think about cardinality and the \"size\" of sets as a way to count, but maybe they didn't develop math that way.\n\n3. Limits, which are important in calc and beyond would be hard to think about without our idea of spatial reasoning. We imagine numbers getting \"really close\" to another number. But how would a race without the same senses/concept of duration/spatial capacity get to this concept? \n\n4. Both mathematicians and philosophers love to think about math as purely (or nearly purely) conceptual. That means they think it's all in the head. Have you ever tried to integrate in your head? It's not that easy, and it only gets harder with more complexity. That means the math has to get channeled into a written form. There's like zero chance (super technical, I know) that an alien race and we have a mutually understandable set of characters. So communication is pretty much out without telepathy.\n\nI'm sure there are more possible problems, but I can't think of them right now. Don't get me wrong, math is beautiful and super cool, but it's not quite as straightforward as everyone thinks. And when it gets more complex, we start dealing with [formalism](_URL_0_) and the question about whether any of this is actually real at all.",
"Theoretical math major who has studied mathematical logic here.\n\nLet's consider whether there are things that are universally true. Consider the following:\n\n\"If all dragons are green and I'm a dragon, then I'm green.\"\n\nIs this true? Most would say that it is, even with knowledge that dragons don't exist. In fact, it seems that anything of the form\n\n\"If *P* and *P* implies *Q*, then *Q*\",\n\nis true.\n\nBut wait. Such a sentence doesn't even reference the physical world. It seems to follow that we have at least one proposition that is true independent of the physical world. We can strengthen this claim by considering what physical property all physical pairs, *P* and *Q* that satisfy the above statement must have in common. It seems the answer is \"nothing\".\n\nThe above proposition is basically a logical rule. It's called \"[modus ponendo ponens](_URL_1_)\". It is just one of multiple basic formal rules that seem to be universally true, independent of everything else. In fact, whenever we reason about the physical world, we necessarily use such rules. In a sense, math is just a purification of the use of these rules. It just consists of applying those rules many times over, to see what you can get. This isn't the whole story though.\n\nThe proposition above is a conditional (something of the form X implies Y). The first part is called the \"antecedent\" and the second part is called the \"consequent\". As it turns out, humans don't care much about conditionals. Humans are mostly interesting is what's independently true like:\n\n\"There are three monkeys in my yard.\" \n\n\"Earth is 9.8 million miles from the sun.\"\n\n\"1 + 1 = 2\"\n\n, etc.\n\nThis means that we have to decide which **non**-conditional things are true, beforehand, so that we can say that the consequent is true. E.g,\n\nI am a man\n\nIf it's man, then it's mortal\n\nTherefore,\n\nI am mortal (non-conditional statement which we would then say is true)\n\nThe same is the case or is not the case in math depending on who you talk to. Most mathematicians would say that they only care about what conditionals are true, where the overall antecedent is some special, universally agreed-upon collection of statements. Others would say that those \"starting points\" are true and thus, math can show you what is unconditionally true. These starting-point statements are called \"axioms\".\n\n[Here](_URL_3_) is an example of some simple math.\n\nAxioms are statements that are very simple and that everybody agrees are either true or meaningful. Although they have shown to be consitent with and predictive of physical behavior, we have no way of telling how complete its correspondence with physical laws is and whether it's just a coincidence. The axioms are inherently arbitrary. By definition, they can't be proved. In fact, the axioms of math have changed greatly over that past 100 years in response to their having certain absurd consequences ([Barber paradox](_URL_0_)). Although they have settled in to field of set theory, they have not even always been described in terms of sets ([Euclidean geometry](_URL_2_)).\n\nAlthough, given their correspondence with the physical world, we would expect aliens to use similar axioms, we have no way of inferring what axioms aliens would actually use. However, it seems clear that they would use their axioms in the **exact** same way and would thus be playing the exact same game, just with different starting configurations.",
"Math is simply organization of amounts. If you have one apple, and you buy another apple, you now have two apples. 1+1=2. If you have two baskets of 6 apples, you have 12 apples. 2x6=12. \n\nAmounts are non-negotiable. One (1) thing is one (1) thing whether you call it 'one', 'uno', or 'zyzznog'. \n\nNow, as for what you name and measure some 'things', that would probably vary. Even within our own species we have discrepancies here. For instance, 1 mile = 1.6 km, but (most) Americans still understand what Europeans mean when they say 10km. No matter what the aliens call it, or how much the unit represents, one alien unit will convert to some amount of something in human units (miles, km, days, gallons etc). If an alien said, \"it is 8 parces from the Earth to the Earth's moon,\" we could deduct that 1 parce = 1/8 the distance to the moon, or 29,862.5 mi.\n\nTL;DR: the rules are always the same. The way we organize and communicate them can change, but we're still all describing the same things. ",
"I am always intimidated by the \"intelligent life\" argument, because I'm pretty sure I'd fail the test :). What if they don't use a base-ten system? Is it easy for an \"intelligent life\" to figure out meaningful information when they start with, \"Hey - that's not random\"? I always figured communicating would be like code-breaking. What if aliens can communicate real information in a random way? Would we notice the communication in the first place? Also, do you think Darwinian evolution happens on other planets? How would life develop into an intelligent form without evolution?",
"It's absolutely not arbitrary. \n\n2 + 2 = 4. It doesn't matter if you call 2 \"flickorp\" and call 4 \"beeliebop\", it wouldn't change the fact that when you put two items next to two other items and count them, you would end up with four items. \n\nflickorp + flickorp = beeliebop; 2 + 2 = flickorp + flickorp"
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2g1r9d | why are there so many typos in phishing emails? | Is it really just that their English is bad? Why aren't there any intelligent phishers? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2g1r9d/eli5_why_are_there_so_many_typos_in_phishing/ | {
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"Depends on the scam. Often phishing emails trying to get you to click a link that installs malware or ask for your password are quite well written.\n\nPhishing emails like the Nigerian 419 scams trying to get you to help liberate $20 million are different. True, they are non-native english speakers. But they also leave the typos in to weed out skeptical people. They don't want to waste time on them - they only want replies from people who aren't going to be dissuaded by a few typos.",
"Partly to fool spam-blocking software. If you write one email but spell things differently a hundred different times, it confuses the filters."
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54xew1 | what is that sinking feeling you get as you come to grips with the reality of the passing of someone you were close to? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/54xew1/eli5_what_is_that_sinking_feeling_you_get_as_you/ | {
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"Fear.. the instinctual reaction to a threat/change to your current life and environment. That person is gone and you fear how your life will be different since this reality is new and unknown.",
"I depends on the person and your relationship.\n\nI think it could be cause be relief of the passing of someone in pain, that they found some peace.\n\nIt could come from regret, from feeling as if your last interaction with that person was negative.\n\nIt could come from the realization that the happiness they provide in your life will still be there in your memories.\n\nIt could come from the acceptance that nothing you can do will change the situation."
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1ln6mj | why is it acceptable for there to be ethnic related scholarships (african american only, hispanic americans only, indian americans only, etc) but it's considered racist of there was a scholarship for caucasian americans? | I'm looking up scholarships for school and I can't apply for about 75% of them because I'm not part of that ethnic group. Out of curiosity, I looked up "Caucasian only scholarships" on Google and found out there was a big uproar at Columbia University for introducing a Caucasian American type of scholarship. I'm not trying to cause a race riot here. Please keep this civil. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ln6mj/eli5_why_is_it_acceptable_for_there_to_be_ethnic/ | {
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"They definitely exist. I got a scholarship from the Sons of Norway. I'm sure most nationalities have an equivalent.",
"Because even with all those scholarships earmarked towards minority students, [white people get a disproportionate amount of scholarship money](_URL_0_). They get 76% of available funding, but are only 62% of the student population.",
"It's considered acceptable because there's no history of systematic discrimination against white men in America. Scholarships awarded based on race are basically supposed to be a way for underrepresented groups to get a \"leg up\" in college admissions. Most people don't really think that white men, as a group, need extra help.\n\nI personally think, as someone who is benefiting from a minority scholarship, that it's not really a good way of doing things, but it is what it is.",
"Scholarships do exist, but they aren't called \"Generic Scholarship For White People Only.\" You'd have to be more specific, like be a Son/Daughter of the American Revolution, or of Irish, Russian, German, etc descent."
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4v0065 | what is responsible for the increased prevalence of sickle cell anaemia among people of african/caribbean/middle eastern origin? | There has been a well documented link between increased prevalence of the disease among black people, or at least countries in which they are the predominant racial group.
But critically, *race is a social construct* - it doesn't have any biological basis. There is so race chromosome, gene, or whatever. It's just something humankind has used to differentiate between one another.
So it would seem impossible that here is literally a link between being black and a disease, so I'm asking:
1) What is the common feature that makes black people susceptible to the disease?
2) What is it about this common feature that is so pervasive among black/people? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4v0065/eli5_what_is_responsible_for_the_increased/ | {
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" > 1) What is the common feature that makes black people susceptible to the disease?\n\nThe simple answer is that it's genetic. While race is a social construct to some extent, there are definitely genetic components to it. Historically, people of the same race would have children with one another way more often than people of other races, who often lived in different parts of the world. As a result, members of particular races may be more likely to have certain traits than members of other races. For example, ethnic Africans are more likely to have genes that specify darker skin than ethnic Europeans. \n\n > 2) What is it about this common feature that is so pervasive among black/people?\n\n[Here's a map](_URL_1_) of where the sickle cell trait is most common. [Here's a map](_URL_0_) of where malaria was most common historically. \n\nIf a person gets a copy of the sickle cell trait from one parent and a copy of a non-sickle cell trait from the other parent, they are protected from malaria. Since malaria can be deadly, having a copy of the sickle cell trait can be advantageous in an area where the disease is common. In malaria-free areas, the sickle cell trait has little benefit. Since sickle cell disease causes problems too, it is just harmful in groups of people not exposed to malaria. \n\nIn short, the sickle cell trait is helpful for people in places where malaria is most common. Malaria is common is places like Africa, so ethnic Africans are most likely to have the sickle cell trait. ",
"A trait of sickle-cell Anemia is that it makes the people that have it resistant to Malaria. Now, under normal conditions, having sickle-cell Anemia would be a purely negative trait. However, in areas where Malaria is common, such as sub-Saharan Africa, having Sickle Cell Anemia might actually improve your chances of survival.\n\nNow, people who live in these areas are usually black, and so their descendants would also be black. So it's more common in these people because their ancestors needed Sickle Cell Anemia to survive.\n\nBasically just a quirk in evolution.\n\nI hope that answers your question.",
"Disclaimer: I am not an expert on genetics, nor am I an expert on malaria. I only know what I know from the few years I spent as a biology student and from what I've read about malaria online. If I am wrong about any of this, PLEASE PLEASE PLEASE correct me. I'd rather be chided for telling a half-truth or untruth than give someone incorrect information. Thank you. Also, sorry, I'm not really explaining it like you're five, I'm more just giving a semi-technical explanation.\n\nSimply put, there is a link between sickle cell being prevalent and areas where malaria is commonplace, and this is because people with the sickle cell trait tend to be more resistant to malaria. The precise mechanisms are unknown, but you can find plenty of info by googling \"are people with sickle cell more resistant to malaria.\"\n\nTo get into a little deeper detail, you first need to know some introductory genetics. Many traits are passed down via alleles, which are forms of a gene (formed by mutations - hair color, eye color, and many other traits are determined by alleles. Eye color is a very common example) that get passed down by your parents. For any given allele, there's usually only one version per parent/chromosome. \n\nThere are many different ways that alleles can react with each other, but we'll look at the sickle cell allele simply as a \"has it\" or \"doesn't have it\" allele, in which having one \"has it\" allele and one \"doesn't have it\" results in mild sickle cell, two \"has it\" alleles result in severe sickle cell, and two \"doesn't have it\" alleles result in no sickle cell. This may be wrong, so as with any of this, I ask that someone please correct me if I'm wrong. I haven't dealt with genetics in a while, and I've never formally learned about the way sickle cell is passed on. \n\nSo assuming that the sickle cell trait is inherited purely by the presence of one of two possible alleles in a person, we can map out a simple Punnet square. That's a little tough to do without fancy formatting, so bear with me. So the two possible alleles for this will be \"S\", which codes for \"has it\", and \"s\", which codes for \"doesn't have it.\" Assuming that both parents have mild sickle cell (Ss), there are 3 possible outcomes for offspring, with different likelihoods:\nSS (25% chance) = severe sickle cell - while highly resistant to malaria, significant complications can result from the severe case of sickle cell.\nSs (50% chance) = mild sickle cell - resistant to malaria, but there is a chance of complications from the sickle cell disease.\nss (25% chance) = no sickle cell - no longer resistant to malaria, but also no sickle cell.\n\nIf one parent had the genotype SS and the other ss, you'd see a distribution of 100% Ss alleles. If one was SS and the other Ss or one ss and the other Ss, it'd be 50% SS, and 50% Ss.\n\nSo an answer why the \"races\" found in those regions are more susceptible to sickle cell is the same as why they have darker skin than Europeans: it's an adaptation to their environment. While sickle cell doesn't necessarily seem like a beneficial adaptation, it became so prevalent because it gave those with it a better chance of successfully reproducing. And ever since then, it's been passed down through the generations - even in areas without malaria - because we've found ways to treat it instead of letting everyone with sickle cell die young because of it. \n\nThe percentage distributions I listed above are by no means absolute, either. They're just in a perfect statistical world. So while you'd expect a much larger portion of the population to carry a sickle cell allele, but in reality, it turns out to be a far lower number."
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5nqfb5 | when we're sick we go to bed, but why does it take a couple of minutes before you feel it when you get out of bed again? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5nqfb5/eli5_when_were_sick_we_go_to_bed_but_why_does_it/ | {
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"Your body adjusts a lot of homeostatic processes for upright vs lying down. Things like blood pressure, heart rate, vasoconstriction."
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52rbw3 | why is it that after i stretch, my whole body momentarily feels tired and weak? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/52rbw3/eli5_why_is_it_that_after_i_stretch_my_whole_body/ | {
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"Blood is being re-routed fairly dramatically with large stretches (which is a large part of why they're good for you). Parts of the body using that blood will briefly have less access to resources - or feel sluggish."
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3y3dhe | if everyone streamed video at the same time today, would the internet stop working? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3y3dhe/eli5_if_everyone_streamed_video_at_the_same_time/ | {
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"First of all. Those 2 comments tou wrote should go in the body of your post, not in the comments section.\n\n & nbsp;\n\nSecond, \"internet\" isnt a resource. You cant run out of internet. The internet is just a global network of computers. It is limited by bandwidth: how much information you can send at one time. The connection between ISPs, and countries can support a lot of information. The bottleneck would be individual companies and your own home network. If every person who had internet access tried to access the same webpage at the exact same time then it would just cause the webpage to be unresponsive. The internet would still exist. So if everyone tried to use Netflix at once then Netflix might slow down, or individually people wouldn't be able to access it. Nothing would happen to the internet itself.\n\n & nbsp;\n\nISPs dont worry about running out of bandwidth. They just want to make more money so they want to charge you for the amount of information you access on the internet. US internet is amazing. Your friends are liars. US ISPs suck because they have a monopoly over certain areas of the US. This means they can raise prices and have crappy customer service. They constantly try to get you to buy more from them. The internet connection itself is amazing. The companies that provide it suck.",
"If everybody started a large data transfer simultaneously world-wide then the lines would get saturated and everything would get slowed down. That's basically it. Once enough of the data transfers were finished or cancelled it'd go back to normal.\n\nThe internet is more like a road system - you can run out of space for more things to move around on it, but you can't really run out of 'road'.",
"It depends on how the video is sent.\n\nStreams like YouTube are not really streams, but closer to a download that only sends part of the file at a time as you need it. \nThis is known as Unicast which means the data is sent from them straight to you. \nIf 10 people on your block with cable modems kicked off the same Youtube video a few seconds apart from each other, there are likely to be 10 copies of the data coming from Youtube to your ISP and so you the more users the more possible it is to run out of bandwidth somewhere in the system.\n\n^.\n\nStreams like Twitch are often sent using Multicast, which is a special type of transmission where you \"subscribe\" to the stream of data. \nIn Multicast mode, the source only sends out 1 set of packets and then all the routers and switches between them and you forward on the stream to any port that has subscribed. \nIn this mode, the pipe feeding your ISP is only receiving 1 copy of the data and then sending the data to any of their customers who wants it. \nSo every pipe only has 1 copy of the data flowing through and is not likely to get saturated. \nLive events are likely to be Multicast so everyone sees the video at the same time."
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22hlu5 | why does drinking alcohol soon become 'addictive' while drunk? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22hlu5/eli5why_does_drinking_alcohol_soon_become/ | {
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"Drinking raises your pain tolerance and lowers your social inhibitions. You may be hesitant to get drunk while sober, then get buzzed and decide to go all in because it started to feel nice and it's helping you have fun."
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3y8v7m | why are aliens generally portrayed/imagined as green or gray? | Where did the stereotype come from? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3y8v7m/eli5_why_are_aliens_generally_portrayedimagined/ | {
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"Alleged abductee reports.\n\nThe term \"little green men\" has existed for nearly a thousand years for other supernatural creatures such as gremlins and goblins, but started to be applied to aliens after reports of alien and UFO sightings started to increase especially in the 1940s and beyond (edit: sorry, I initially put \"abduction reports\" which was misleading; the first proper report of abductions was the 1966 Hill case mentioned below). It was probably intended to be derogatory, likening UFO encounters to long-disbelieved encounters with fairies and monsters. One big contributor was [an incident in Kentucky in 1955](_URL_4_) which really cemented the idea.\n\nGreys have a very specific origin: [One reported alien encounter in 1966](_URL_1_) which just became the commonplace appearance for alleged abductees to report. \n\nI know we're supposed to be objective and unbiased in toplevel replies, but it's basically a case of people claiming/pretending to see what they think people want to hear because making up something really weird and outlandish wouldn't be as believable as saying \"oh yeah I saw the same thing as other people in this area have seen.\"\n\nEdti 1: Guys, if you want to discuss the idea that aliens are real, please post sources. If you're going to make claims about reports from indigenous tribes that never saw a sci-fi book cover or from a century before \"greys\" were cool etc, then post links to them, otherwise you're just adding to the layers of hearsay and claims nobody has any reason to believe.\n\nImportant edit 2: Check out [this awesome Carl Sagan quote](_URL_0_) posted by /u/HitByARoadRoller that explains some of the evolution of alien depictions in western culture.\n\nIf I get unlazy and work remains quiet later on, I'll probably add something about other popular, commonly-repeated depictions such as \"[nordics](_URL_3_)\" and David Icke's beloved \"[reptilians](_URL_2_)\". Have some wiki links in the meantime.",
"There's a lot of reasons varying from false encounters to purposely sound ridiculous (which of course caught on), to sleep paralysis, to hallucinogens. Since there is such a large stereotype of what we think aliens look like now, people tend to think of greys as what all aliens look like. \n\nThen you have super alien enthusiasts (I love aliens, but these people are above and beyond) who say aliens have some to them in their sleep, they gave birth to aliens, etc. And that's how they know. ",
" If you look at most depictions of aliens in Hollywood, they're actually not the greys or the greens. They're usually a lot more imaginative, from the aliens from the Alien series, the Predators, right down to Admiral Akbar. Give Hollywood a little more credit! \n\nHowever, the grey/green archetypal alien is so powerful because there is no overt physical strength to its body, just an out of proportion head and eyes... which make them seem all seeing and all knowing, like they have absolutely no need for physical strength. Very powerful, more human than human. ",
"There must be some adaptive reason. For example, their atmosphere may have an inconvenient optical window in that range of the EM spectrum, or perhaps it's a vestigial aspect of when their ancestors were subject to pressure related to predation.",
"I've heard a few theories of the stereotypical alien abduction being possible repressed memories of child birth, being pulled into the light, slender white beings(doctors) examining you with lights and objects. ",
"This is covered in the Roswell episode of Drunk History, if I remember correctly.\n\nAlthough top comment is pretty informative.",
"In a book about Aliens called \"Communion\" by Whitley Strieber, about a man who believes he is abducted in his home, he is put under hypnosis in a therapy session to say what he saw. He describes the aliens as little gray people.",
"I'm ignoring \"little green men\" in favor of the \"gray\" archetype - oversized head, small or no nose, overly large eyes, skeletal frame, often naked.\n\nThe large head and eyes bring to mind a child. But this is contrasted with the grey, dead skin and skeletal body. Together it creates an image of timelessness, both eternally young and eternally aged.\nWith a large head and large eyes it seems to symbolize a being with great wisdom and perception. An entity that has evolved beyond time, representing some cosmic truth. It appears to be physically frail and helpless, but somehow has a great power to inspire experiences of fear, paralysis, and abduction. The neutrality of the grey color and the physical frailty differentiate it from a god or demon archetype. It doesn't possess the quality of absolute good or absolute evil, but rather a neutral, seemingly technical interest in humanity. \n\nThis is based on a google search for \"grey symbolism\" and some ad-lib associations. I have an interest in CG Jung so I'm imagining the documented appearance of the Grey Alien symbol as a communication from the collective unconscious to individuals who are particularly receptive to it, in the sense that unacknowledged issues in their personal lives are relevant enough to be viewed as playing out a certain archetypical pattern represented as such.\n\nThe overall Grey Aliens story is usually abduction (if we're confined to eyewitness accounts and not popular fiction). A person is immobilized and transported to a ship, inhabited by grey aliens. The aliens either strike up a conversation which conveys cosmically significant information beyond the grasp of language, or alternately rudely examine the subject like doctors in a surgery. After some period the person finds themself in their home, sometimes having lost hours or days of time, or finding no time at all passed.\nAssociations:\n1.The feeling of helplessness\n2.Being forced to go someplace you don't want to\n3.Being imprisoned\n4.Imprisoned on a vehicle that is taking you into the unknown\n5.Interacting with a consciousness that is not like your own\n6.The superiority of this alien consciousness over your human consciousness\n7a.Being examined, or monitored by some superior entity\n7b.Receiving messages from a superior entity\n8.Having an experience outside linear time\n\nMy associations bring to mind a person who was raised in a religious tradition, who is unconsciously questioning their faith in coming to terms with death/dying and what comes next, but is unable to deal with those thoughts consciously and is therefore repressing them by doubling down on the idea of God and Heaven in the afterlife. Helplessness and abduction in an extraterrestrial vessel mirror our soul's incarnation in a physical body and it's inevitable voyage towards death. The Grey Aliens represent a counterpoint to the God/Devil image, questioning the religious dichotomy between Good and Evil with their neutrality, watching and observing humanity but more with a sense of curiosity than a sense of absolute judgement. \n\nI don't know how far fetched this sounds to Joe Reddit. I guess what I'm saying is that Christians who's understanding of death is in conflict with their faith, and who turn away from resolving or even acknowledging this conflict (because it would be too painful) might become so psychologically perturbed that the mind has no choice but to play out the conflict in visionary experience. This visionary experience is similar between different people because they have the same religious associations, the same color and form associations with youth, aging, time, death, and so on. \n\nThe Greys are an un-God/Devil, neither good nor evil, not judging or condemning, but still eternal and transcendental. Instead of the cosmic One, they are the cosmic many. The UFO realm is an un-Heaven/Hell, a higher plane of existence outside life and death, but not a judgement or sentence.\n",
"In short, \"Invaders from Mars\" came out in 1953 and had little green men. An episode of the Outer Limits in 1964 had little grey men. The \"alien abductions\" coincide with these. Fill in the rest with LSD, misunderstood sleep paralysis, fever nightmares, and heavy doses of attention-whoring bullshit and you have the explanation for basically every \"alien abduction\". Nobody came up with these descriptions without cultural influence. ",
"I read a book once, can't remember the name, but it was a history of the ufo phenomenon. It described how the 'flap' started just after ww2 with just 'objects in the sky'. Mid 50's people were seeing benevolent aliens warning of the dangers of nuclear power, by the 60's reports of abductions were coming in. It comes as no surprise that the Roswell incident came up in the 70's, as people were starting to mistrust the government. ",
"The best explanation I've heard is that early (and flawed) views of evolution (e.g., [Georges Vacher de Lapouge](_URL_0_)) influenced expectations about the appearance of aliens. These early views held that humans have \"progressed\" through evolution to have lighter skin and less body hair. Extrapolating this trend millions of years into the future (the time span required to develop interstellar space travel) would mean that more advanced species would eventually evolve to have grey skin, large eyes, and no body hair--the classic Area 51 alien.",
"My guess:\n\nWhen you're walking outside on a dirt path at sunset, your shadow looks like a tall, slender grey figure. Thin head and long slender fingers. The cool tone of the shadow on the brown dirt makes it appear gray.\n\nThen when you're asleep, your dreaming brain processes these images and makes up stories about slender greymen with narrow heads, on occasion. Just enough to freak you out a little.\n\nThis could have happened in any culture, in any century.",
"eyewitness accounts. for the greys at least",
"Because they are grey. This purposely leaked knowledge will lessen the psychological impact when they are made known.",
"id imagine because, for the most part, those colors arent really included in the human race skin pigments. there are (in a relative manner) redish, bluish, blackish, really black near purple-ish, whitish, pinkish, orangey, yellowish, khaki-ish, tan-ish, blah blah, blah-ish, nearly every color skin colors, save for green and grey (except for when your dead/dying). \n\nSo, since green and grey arent a natural skin pigment for us, we apply it to the fictional representation of that as the extra-planetary human race equivalent. you know? To, like, make them different. \n\nthats my 2 cents, at least.",
"I remember reading somewhere that when we are infants, human beings look like tall slender grey people with huge eyes. So when people are \"abducted\" later in life, they are actually recalling these repressed memories of \"alien\" figures. I'll try to find the source but thats pretty much what I remember from the top of my head.\n\nEdit: [This](_URL_0_) is sort of a source for what I was talking about.",
"So they'll be color coordinated with their space craft. Life is all about fashion. Sheesh! Who didn't know that?",
"Think of all the colors which are easily recognized but don't apply to natural human skin tones. Why are green and gray more common than orange and purple? No clue. Artistic license?",
"If you tell them they're going to see little green men, then they're going to see little green men.",
"Because that's their actual color.\n\nYou see, if you put something in a movie, people will immediately assume it's fake. When a photograph of an actual alien leaks out, and it looks exactly like it does in some movies, people will go \"Oh, it's obviously fake. Looks like something out of a movie.\"\n\nIt's a great way for the government to mask the truth.",
"Basically the stereotype is a conglomerate of exaggerated human-specific features. Sallow, ashen or green skin indicates a complete detachment from natural solar rays - suggesting that these creatures, like we do, are (physically) the product of exclusively artificial light of their own invention (like some humans). The big eyes likewise indicate advanced receptivity and comprehension, as foes the engorged cranium which indicates potent cerebral capacity. The spindly quality of their appearance overall suggests that physical strength has been compromised to maximise dexterity and meticulous and refined bodily activity; a suggestion reinforced by the long and bony fingers. Finally - hairlessness compliments the aforementioned artificial existence (high tech environment) and the small or absent mouths indicate the potential for ditect mind-to-mind communication. Hunans underwent many similar (but far more subtle) developments as we evolved independently of the great apes - muscle mass, body hair, and other physical defences etc. giving may to nimble fingers and, to manipulate them, more proportional grey matter (i.e. brain). \n\nTL;DR - the trope of the little green men is an unconsciously anthropocentric projection of a greatly exaggerated version and future version of itself.",
"This is off-topic, but still sort of related.\n\nEver wondered why the ghosts in Japanese horror movies are portrayed as wearing long white dresses and having pale skin and long, black hair covering their face? This appearance has become really widespread and it's been used outside Japanese horror imagery too.\n\nBut where has this portrayal originated from? One would think that maybe from some eyewitness reports or ancient lore, but no. The appearance was developed in the Japanese kabuki theatre. The number of actors involved in a play was limited, so every actor had to play several roles; this necessitated them to switch from role to another swiftly, and make their characters clearly distinct from each other for the convenience of the audience. Putting on a long black wig, a white burial kimono and blue face paint was a handy combination of appearing as a ghost on the stage. \n\nEven though OP's question is about aliens, not ghosts, I still think the kabuki explanation is pertinent here. It is interesting how cultural conventions can influence \"real life\"; a great number of alleged ghost sightings, or perhaps more like ghost *experiences*, lack the element of visual encounter altogether. Ghost encounters are usually described as sensations of an unnerving presence, or an unexplained sound. Depictions of ghosts in art and on film are not really based on anything but artistic licence, because extremely few people have ever claimed to having actually seen a ghost. Artistic interpretations tend to fill up this visual blind spot, and alleged eyewitnesses buy into this fabricated visualization of what they think they've experienced because they believe the appearance of ghosts is based on people's reports; this way they perpetuate the cycle of third party interpretations becoming \"real\", when there's no basis these interpretations. This applies, I believe, to aliens and all sorts of supernatural beings as well. \n\n ",
"A Princess of Mars.\n\nScience fantasy novel by Edgar Rice Burroughs. It was first serialized in the pulp magazine All-Story Magazine in February–July, 1912.\n\nSet on Mars with green Martians.\n\nGreen Martians in 1912, yo!\n",
"Late to the party, but one idea I've not seen presented in this thread yet is that grey and green are frightening, due to mankind's innate fear of disease. That's going to make stories of grey/green aliens more compelling and thus more likely to influence future stories, either consciously or subconsciously.",
"When I was learning to use green screens, I was told green is typically chosen because it doesn't occur naturally in skin as much as other colors. Doesn't seem too far a logic leap to suppose were just trying our damndest to depart from the human norms when the little men are green. ",
"Because there are\n\n- yellow people\n\n- black people\n\n- brown people\n\n- white people\n\n- red people\n\nbut fur sure there are no green or gray people - best color for some alien.",
"\"The things that were supposed to be green in the black and white movies... They get you in the neck when you're not looking\"\n\n- Frank Zappa (The Radio is Broken).\n\nAnd that's all the explanation you need!",
"Because its much easier to believe we can kill/defend ourselves if the ones we are fighting look different. If they looked like you and me people would lose there shit. Look how bad we are with the Syrian refugees and terrorists. We can't readily tell them apart and that bothers a lot of people.",
"I'm pretty sure the description is born from the abduction phenomena reports. There are also reports of giant insectoids(praying mantis), and tall 'gray' aliens. Sometimes you will even hear about tall blonde, or nordic, type people.",
"If it's not like you, it can't look like you.\n\nhuman skin color goes from mostly red tones to yellow tones, a little blue hardly green.\n\nit's only natural one imagines an equally complex organism in the inverted colour palette* (green, blueish) so it can have the same form but no same color of our body\n\n\n^*simplified",
"Grey and green are the colours people go when they're ill or dead. Illness and death are psychologically linked with otherworldliness. Elves, vampires, and other undead, are all traditionally depicted as pale, deathly figures.\n\nThere's a sleep condition linked to visitations like elves and aliens called Sleep Paralysis. In this condition and others (e.g. psychedelics), the dreamlike state and psychological metaphors link to produce images of otherworldly beings and personalities.\n\nIn order to produce that emotional link with these beings and the otherworld, the subconscious evokes symbols of death using your memories and imagination.",
"Edit: got a downvote already. Instead of downvoting me, tell me why I'm wrong. \n\nOk. Anecdotal story here and I really hope someone can shed some light into this. \n\nI want to clarify that I am not crazy and I'm a huge skeptic when it comes to this kind of stuff and that I do not believe aliens roam around earth or abduct people. I also dont belueve in ghosts or anything like that. My experience may have been an optical illusion.\n\nThis was in Guatemala back in 1998. My friend and I were at home during the afternoon and at night we decided to walk somewhere. About 30 seconds into our walk, I see a little green fluorescent looking, 2-3 foot tall, old sasquatch paced \"man\" walking next to a very long and tall government building wall where there were no entrances, stairs, etc. \n\nDumbfounded, I paused for a second and asked my friend if he had seen what I had seen. He said yes. We then ran up to that wall which was across a two lane street and found nothing, as if the thing had been swallowed up by the ground. We ran in both directions and nothing. \n\nTo this date I have no idea what that was and the strangest part is that I asked my friend about it about a year ago and he remembers none of it and he has an excellent memory. I mean, he remembers the names of girls that I dated that I couldn't even remember. \n\nThis has always been a mystery for me. Every time I bring it up here the comment gets zero traction. ",
"Green/Silver. I think Grey comes from movies aiming for silver but either way they are the 'unhuman' colours. So we cannot relate or look as 'alien' (foreign).\n\nThe entire popular Alien is this way. It goes something like this:\n- Neanderthals were early men. To fit the theory of evolution the more powerful stronger Neanderthals were 'skinned' with ape-like hair and presumed dumb, unintelligent and so the modern human is less hairy, more slender, smoother and more intelligent.\nSo the 'further imagination' goes over to even smaller slimmer smoother and even more hairless creatures.\n\nThe Most 'alien' or 'foreign' appearance but also sophisticated and mysterious cultures to Westerners were the Chinese, Japanese and so the 'slanted eyes' were integrated into the pop-culture. (often they were just blatantly Mongolian or Chinese: see Star Trek or some were just named 'Ming' and were Chinese Ming Dynasty Emperors in spaceships heh). \n\nOh, add to all this the most foreign and alien of animals to Westerners of the day may well be the lizards though I suppose we'd know frogs well enough. but notice the evolution of the alien in pop-culture and what we'd suppose are strange and most alien of lizard (tropical lizard) type features. \n\nMergey-mixy until you just get these green-grey 'anti-neanderthal' asian-eyed lizardy humanoids of some high IQ.\n\nAs pointed out already - if its gray (or green/gray white sorta things) its also what we associate as dead. Which we associate as mysterious 'unhuman' and otherworld (heavens, afterlife) sort of imagery. \n\nSo fuck you aliens. ",
"Nobody described aliens like this until movies came out. It's like pirate-talk - it never existed until it was done in a movie.",
"I suggest the colors are chosen by process of elimination. Grey is universally considered a scary skin color because that's a color corpses turn. Green is one of the few colors that is definitely alien for a humanoid. Red people are considered flushed, bloody, demonic, etc. Blue people are suffocating, members of a dancing troupe, or have Argyria. Purple is kinda gay and is a mixture of two \"taken\" colors. Everything in the brown, black, or yellow spectrum are natural skin tones.",
"To expand on your question, the typical image of an alien is green/gray, short with an usually large head. Most people will imagine this when the topic of aliens are brought up. \n\nAn interesting theory on why we jump to this image in our minds has to do with a distant cousin of our ancient human ancestors: the Boskop Men from Africa. They were a humanoid species that, from what experts in the field have determined, had huge propensity for intelligence (they also had huge heads since their brains were bigger) and were a fairly short and physically weak species. The theory goes that our ancestors interacted with this species and saw their diminutive size and superior intelligence to be \"alien\" to them, and this impression ingrained itself in our species collective mind. \n\nThis is just a theory and I'm not saying I support it, but it is pretty interesting and the whole notion of the little Boskop men existing alongside is at one point is awesome!",
"Most reports of sightings and abductions happen at night when humans' colour vision is weakest.",
"I'm surprised that nobody has tried to suspend disbelief and science this thing. Like, what function does pigment play in mammalian skin? If you assume stories about the greys being genetically engineered human-like beings, what might cause the skin to turn greyish? What incentives might there be for grey skin? Might it be a side effect of modifying some other gene?\n\nIf we assume they're not genetically modified human-ish beings, but people who evolved on some other planet, maybe it's a camouflage thing. Maybe there's some evolutionary pressure for grey skin."
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"https://en.wikipedia.org/wiki/Betty_and_Barney_Hill_abduction",
"https://en.wikipedia.org/wiki/Reptilians",
"https://en.wikipedia.org/wiki/Nordic_aliens",
"https://en.wikipedi... | |
2e6k93 | why do we have shoulderblades? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2e6k93/eli5_why_do_we_have_shoulderblades/ | {
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"It connects the upper arm bone to the collarbone. Many muscles attach to it. The \"why\" for its existence stems from our long evolutionary past.",
"The shoulder blade or \"scapula\" is main bone in which the collar bone or \"clavicle\" and the upper arm are connected to.\nThe shoulder blade provides movement (accompanied by the muscles attached to it) flexing your arms-chest inward, outward, etc. Most, if not all of your range of motion by your upper body/ligaments requires the shoulder blade."
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22amv0 | the ladyboy culture in thailand | Why is it so popular over there? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22amv0/eli5_the_ladyboy_culture_in_thailand/ | {
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"Don't think it's exactly 'more popular' that anywhere else... Just more open/visible/tolerated thus attracting more people from abroad interested in that. \n\nSame with 'normal' p4p...its everywhere in the world... Just more accessible (and generally cheaper) here thus so many coming here for it. \n\nBasically build it (and get known for it) and they will come ",
"I'd say it's not that it's popular there. It's just well known.\n\n1. People already go to Thailand for sexual tourism.\n\n2. Part of that is experiencing new things they wouldn't risk at home: Prostitutes, pingpong shows (and the like), and sex with a transexual.\n\n3. A lot of the Thai are poor in comparison to the visiting tourists. So a woman can stay at home working her ass off, or go to Bangkok and sell herself for a few years. A good week will be enough to support her entire family for two months, so she's going to have a lot saved up. Getting hired as a long term companion for an old man while he vacations? That one or two weeks will cover her family for a year. In addition she'd generally get treated very well. (If not, she can leave and call the police. Turns out, not speaking the local language is very damning; smart tourists don't do anything to get in trouble.)\n\n4. A MtF transexual can make just as much, if not more. And where an American transexual would just change their gender and go about their lives, the Thai might want to do the same as regular woman. Work your ass off for starvation level diet, or get paid to have sex.\n\n5. The MtF transexuals do tend to congregate for protection; as do the women.\n\nRegarding Asians being more passable: It's really easy to understand why.\n\nWhat are the tells or hallmarks of 'masculinity' for most ethnic groups? Height, body hair, more pronounced adams apple (than a woman), hand/foot size, deeper voice.\n\n1. Asians are generally shorter than most other ethnic groups. Compounded when growing up in a poor area with malnutrition. (Not the american style malnutrition where a poor person actually ends up fat)\n\n2. Less body hair. Most of the asian dudes in my classes couldn't grow a mustache to save their lives. When I ran into them at the pool? No chest/back hair. I didn't check out their legs or crotch.\n\n3. Adams apple. Not as noticeable. I dunno why.\n\n4. Hand/feet. Proportional to height I think. \n\n5. Voice. Disguiseable for almost anyone willing to work at it.\n"
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22g2xr | what would happen if someone went in and murdered kim jong-un? would someone else step up, or would the country be a better place? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22g2xr/eli5_what_would_happen_if_someone_went_in_and/ | {
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"Hard to say. Worst case, it leaves a power vacuum that ends up with people competing for leadership leading to a bloody civil war. Best case, someone is clearly next in line and steps up, leading to a less insane rule.",
"He's got a full blood brother and sister, and several half-siblings, and a kid (young, but still his blood).\n\nThe country would keep on turning as is -- no doubt one of them would step into his shoes.",
"As I recall, Un had his uncle killed because he was plotting a power grab. Given that, we can infer that someone else is probably still plotting a power grab, which would likely be facilitated by an assassination. ",
"Thanks for the answers. So what would need to happen, either from North Korea or another country, for the rulings to change and it to become a less dangerous and different country?",
"There will always be another candidate, there is an unending supply of generals etc who would assume power. \n\nI doubt anyone in the current system who has got near enough to the top is a secret democrat.\n\nit would be necessary to decapitate the current system to enable candidates outside the elite to step up. Another method is a popular revolt like the Arab spring.",
"We almost found out, but then he executed his uncle. At this point one of the senior party leaders would take control and the appropriate documents would br \"found\" saying as much. ",
"I asked this question a few months ago and it got a lot of attention and some great replies -- here it is\n\n_URL_0_\n",
"I believe he has an older brother who was denied leadership because he look to feminine. So I imagine as a last resort he would take control of the country.",
"You ever notice the old guys dressed in military garb that follow him everywhere? They're the ones actually in charge. He dies, they replace him with another figurehead. "
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axe4ie | how is certain hardware faster when electricity travels at the same speed? | A CPU or GPU is just a bunch of transistor gates in a really tight space so when you fit more transistors in a tighter space, it becomes faster. But wouldn't have no effect because electricity travels at the same speed and adding more transistors would have no effect. So what makes a certain component "faster" and how?
& #x200B;
Edit: Maybe I didn't word my post correctly, unless each transistor is in parallel and its own circuit (not sure if it is or isn't) then adding more transistors making the time for it to complete the circuit longer making it slower. So that means more transistors doesn't mean faster in theory. But manufacturers always focus on having more of them in a tight space. So why would more transistors make a CPU faster when it makes the circuit longer and adds more resistance?
If the transistors have a circuit of there own it makes much more sense because all of those would complete at once but no one has mentioned that so i'm not sure. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/axe4ie/eli5_how_is_certain_hardware_faster_when/ | {
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"You have to go back to how a switching transistor works: If you saturate the base with electrons, the flow of electrons between the collector and emmittor[sp] will start.\n\nIf you make the size of the base smaller, the reaching of the saturation will happen earlier. As such the switch between a logical 0 and 1 will happen faster.",
"It’s not about the speed of electricity, it’s about the speed of decisions. \n\nSince computers all operate in binary, they make decisions by either saying yes (1) or no (0). These decisions are made by transistors (back in the old days it was vacuum tubes). Let’s for the sake of sanity say that one transistor makes 1 decision (yes or no) a second. Therefore to make 10 decisions it would take that transistor 10 seconds. Ok great, but that’s not good enough for me, so I buy another transistor. Not I can make the same ten decisions in 5 seconds. The speed of electricity doesn’t play a factor. The progression of technology is directly related to how many transistors we can fit on a computer chip. \n\nFor more information, check out [Moore’s Law](_URL_0_). It basically says that the size of a transistor shrinks by half every two years. Hence why computers used to be the size of rooms. \n\n\nHope this helps! ",
"The speed that you are referring to is not necessarily the speed of electricity, it is the speed at which a processor can do calculations. Think of it as yourself doing a multi-step math problem. If you take less time to do each step, you finish faster. A computer does all of its math in steps, and the faster that it can tick the clock that times those steps, the faster it completes the calculation.\n\nThe transistors in computers actually take a small amount of time to switch. Think of it as a gate. That time gets shorter as transistors get smaller. Think of it like a gate: It takes longer to open and close a big cattle gate than it does to open and close a small sidewalk fence gate. If you try to make the computer run faster than the gates can physically switch, you start to have errors.\n\nThere is also the problem of thermal output: as you switch the transistors faster, they create more heat. You can only extract the heat from the chip so fast, so eventually you reach a point at which you literally can't cool off the chip fast enough. If you continue to run it hot, it will damage itself.\n\nWith the speed of modern computers, the speed of electricity is actually a factor. On a circuit board like a motherboard, there are lots of \"buses\" or parallel wires that carry signals. It is imperative that all the signals get to their destination at exactly the same time. However, if that bus makes a turn, the innermost wires end up being a little shorter. Therefore, the signal from that wire gets to the destination slightly faster than the outermost wire. Due to the fact that modern electronics run at multiple giaghertz, depending on the size of that delay, it can cause errors. To correct this, circuit board designers place what look like 's' curves into some traces to basically delay the signal.\n\nElectronics are pretty interesting, and if you want to learn more about them, I suggest watching some of the more beginner-friendly youtube channels. Electroboom comes to mind in that respect. Also, if you want to learn more about the workings of computers specifically, there is a guy on youtube named Ben Eater that built a computer completely from scratch at the gate level. He does a really good job explaining what he's doing and why it works that way."
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61z406 | the 11 dimensions of the universe. | So I would say I understand 1-5 but I actually really don't get the first dimension. Or maybe I do but it seems simplistic. Anyways if someone could break down each one as easily as possible. I really haven't looked much into 6-11(just learned that there were 11 because 4 and 5 took a lot to actually grasp a picture of.
Edit: [Haha I know not to watch the tenth dimension video now. A million it's pseudoscience messages. I've never had a post do more than 100ish upvotes. If I'd known 10,000 people were going to judge me based on a question I was curious about while watching the 2D futurama episode stoned. I would have done a bit more prior research and asked the question in a more clear and concise way. ](_URL_0_) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/61z406/eli5_the_11_dimensions_of_the_universe/ | {
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"First of all, the dimensions don't come in any particular order, so there is no \"first dimension\".\n\nThe three dimensions you are already familiar with are length, breadth and depth, or, put another way, left-right, up-down and in-out, or just x, y and z. Einstein determined that in order to describe the universe, we need to consider time as part of space instead of separate from it, so that rather than the three dimensions of space and another of time, we have the four dimensions of space-time.\n\nThe other dimensions are theoretical ones and are not directly perceptible. They are often described as existing at tiny scales and \"rolled up\". A common analogy is a garden hose: from a distance, it looks one-dimensional (it has length only), but up close, it is three-dimensional (you can also go around it in circles, and through it). The dimensions above 5 correspond to the \"close up, you can go around it in circles\" concept of the \"extra\" dimensions of the garden hose.\n\nEDIT: added missing words",
"You seem to refer to a crackpot Youtube video. That particular video is mostly just gibberish combined with nonsense, it is not based on science or anything coherent, and you'd do well just to ignore it.\n\nFor the most part, there are 3 dimensions in the world. up/down, left/right and forward/backward. Einstein adds time to that list where you could kinda bend objects towards time direction so they appear shorter, but unless you're frequently moving at speeds close to speed of light, you can probably ignore that and just go with 3.",
"I tend to look at it like this. \n\nZero dimensions is a point in space that has an infinitely small volume. If you put an infinite number of these points next to each other you get a line (1 dimension). If you then put infinite lines next to each other you get a plane (2 dimensions). If you stack infinite planes onto each other you get all of three dimensional space. \n\nTo add more space you would need to have each point contain infinite space. Time would achieve this. Each point, even though it contains so little space, if added with itself an infinite number of times over all of existence would give us a fourth dimension. ",
"OP I think you're misunderstanding the concept of a dimension in the first place. There is no such thing as the 'first' dimension. Once you decide you've got a particular number of dimensions (usually 3 if we're talking about things in physical space) they're all indistinguishable. So what is a dimension? Well the number of dimensions simply specifies how many numbers you need to tell where a specific point is: on a flat piece of paper you need two numbers, the first number could refer to how far to move along and the second to how far up but there's no reason it needs to be this way; you could just as easily describe that point by its angle to the horizontal and how far it is away from some specified point. Whatever way you want to describe it though, you always need two bits of information so the flat surface is 2D. \n\nEdit: I'll try and flesh this out to have a go at the 11 dimensions bit.\n\nFirst off, dimensions beyond 3 spatial and 1 time are theoretical. There's still disagreement among string theorists over the number of extra ones they'd like: supergravity has 7 more spatial ones but i've heard the number 26 thrown around as well. I don't think there's any way to intuitively understand why those numbers should be what they are, its just the way the (very) complicated maths works out. As to why we can't move in these extra dimensions, the classic explanation is that they're curled up very small. This is like if you look at a straw from a long way off: it looks like a line (so 1D) but actually you could move around its surface so to describe where a dot on a straw is you would need two numbers.",
"I think others have explained it well, but an interesting theory I've heard- our 3D world is just a \"shadow\" if you will of a higher dimensional world, just like our shadows are 2d projections of our 3D world. ",
"To break it down rather bluntly, each dimension is basically a variable you wish to add to a point in reference to something. \n\nFor example, when we're looking at a map, we generally only care about the horizontal and vertical distance from our location to our destination. Going up and down hills isn't really our concern when we're driving. Therefore that's 2 dimensions. \n\nAnother example would be if you want to study the temperature of your backyard over the course of the year, then time and temperature will be your 2 dimensions. However you if you care about the difference between time, location, height and temperature, then you're looking at 5 dimensions (distance horizontal, vertical, and height from an origin like your back fence post and the ground, the time and the temperature). You're still moving in 3 dimensions in real space, two dimensions on a map, but you care about more than just those things.\n\nSo, \"11 dimensions of our world\" isn't really the wrong inquiry but begs the question back \"what do you care about?\"",
"Sorry for being late, and maybe someone posted this or similar:\n\nCheck out this [video](_URL_0_)\n\nNow, this is the visualization of the 4 dimentions. It is a bit simplistic, but it translates the point. Earth orbits the sun, in a 2D space - on an elipsis. (No it is not a circle, since it is not perfect one - elipsis). However, it also \"wiggles\" slightly up and down from it's trajectory. Oscilates, I believe is the english word for it. So, technically, in order to describe its motion (position of Earth at given intervals), we need the 3 dimentional coordinate system: X - horizontal, Y - vertical and Z - Depth. Now, the fourth dimention is Time. How do we show that? We obviously need a 4th reference point. In the video, the Sun is portrayed as the axis along which we will measure the movement of the other planets. So it is stationary, relative to them. Lets say we put the axis T - time, through the Sun. So the sun moves forwards in time - basically, along the line/axis T. Relative to it, the Earth, which orbits the Sun, now moves not in an elipsis, but in a spiral - a helix. This is why the statement that Earth moves in an elipsis through space (3D) and in a helix through Spacetime (4D) is true.\n\nUnfortunately, I cannot give you a good explanation of the other dimentions. But the answer of r/ohballsman is quite simple - the more you need to describe a given point, to identify its location, the more axis-es you'll need. Each axis is a dimention. 1D is a point. 2D a circle. 3D - a sphere. And 4D... well, best gues is a cyllinder, but that will need some more explaining. (It's sides will be moving in a given direction, at a constant rate, up to infinity.)\n\nI may be wrong on some points regarding time, because of its relative nature.",
"So my analogy is very flawed but it should work for this situation. Let's say that you have a graph, 2d, and you add a new axis in that's perpendicular to all other axis. You just made a 3D graph. Try doing that again and you'll get a 4D graph, if you do it again you have 5D ect. Even though it is impossible for us to completely comprehend we can try. Hope my analogy gives you a new way to think of 4+D space.",
"If you attach a wire from the top of one mountain top to the top of another mountain top and look at it from far away, you can describe any point along that wire with one number. (Like... distance away from the first mountain). That's a one dimensional system.\n\nBut if you get REALLY close... like you're an ant climbing along the wire, you can go along the wire, but also go around the wire. If you're an ant, you need to describe your position using two numbers: Distance from the first mountain, and distance clockwise around the wire.\n\nSo even though the wire looks like one dimension from far away, if we zoom in a lot, we can see another tiny curled up dimension as well. \n\nSo in the world, we see 3 dimensions... X,Y,Z. BUT in physics, the math works out a whole lot better if we have those 3 dimensions... plus another 4 or 7 or 23 tiny curled up dimensions that we don't see because they're so small. \n\nSo all we know is that we observe three space-like dimensions and one time-like dimension. But the math works out better if there are a bunch more tiny space-like dimensions.\n\nI like the book *The Elegant Universe* by Brian Greene for explaining high level physics in layman's terms.",
"I am not positive how accurate this is, but it's a great way to at least start thinking into the 10th dimension: _URL_0_\n\nEDIT: Please see /u/edderiofer comment under here, I had a suspicion this movie wasn't completely accurate and that critique is great.",
"I recommend reading Edwin Abbott's \"Flatland.\" It describes a world of two-dimensions (Length and Width, where Height does not exist), and the creatures in this world encountering one-dimensional beings and 3-dimensional beings helps make the notion of more than three spacial dimensions easy to understand.",
"You can't distinguish dimensions other than the time one. A fourth, fifth and sixth dimension would function the same way the first, second, and third would. \n\nThink of it as three cups of water for the spacial dimension, and one cup of oil for the time dimension. You *can* tell where the oil is, and you can also tell that there are three cups of water, but it doesn't make sense to point to a place in the water and say that the 1st cup is there.\n\nExample stolen from MinutePhysics",
"Imagine the way a wave travels down a stretched rope when you shake one end back and forth.\n\nWaves go down the rope in a very understandable way.\n\nNow substitute a long garden hose. Waves still go along in an understandable way.\n\nIf the source of the vibration is a machine and it speeds up, eventually the waves will be shorter than the width of the hose, and THEN they will start to behave oddly. They don't necessarily go \"straight\" down the length... they can vibrate the material of the hose in other ways, going sideways and around the circumference.\n\nSome of our theories suggest that space is like that at very, very small scales. With extra closed dimensions too small to measure with our too-big waves.",
"The number 11 is from Ed Witten's M-Theory, who is famous for understanding that all the leading models for string theory (which seemed to totally disagree with each other, but each looked right on its own) were really the same, and could be unified once you looked at them in 11 dimensional space.",
"You've gotten good answers, but I'll add some details about using _time_ as a dimension.\n\nIt's easiest to go back to two dimensions of space to think about time. Imagine a slideshow. You can put a dot in the center of the screen, and then move it to the right.\n\nNow imagine a stack of papers, which are the individual slides of the slideshow. On the top one, the dot is exactly in the middle. On the next, it's ever so slightly further right. On the next, it's a bit further, and so on. Moving deeper through the stack is our third dimension, but it represents time.\n\nIf you wanted, you could imagine it as a dimension of space as well, and then you'd have a bent cylinder.\n\n(Also, this leads very neatly into a completely unrelated topic, which is that this is _exactly_ how video works as well - it's just a series of images, the sheets of paper in the metaphor, that the video player is moving through very quickly.)",
"As a mathematician, the first thing I can say is to NOT watch a video called \"Imagining the Tenth Dimension.\" It's poor math and worse science and completely misses the point.\n\nA better way to approach this is to understand what \"dimension\" really means to a scientist. A \"dimension\" is basically anything you can measure with a single number. So, for instance, a line is one-dimensional because you can describe any distance along that line with one number: the distance forward from some starting point. You could use a 1-dimensional measure to describe your position along a highway, or how far you are from the north pole, or the amount of time that's passed since midnight, or so on.\n\nWe commonly say that we live in 3-dimensional space. This is because it takes 3 numbers to describe our location. For instance, you could describe your position relative to the earth using three numbers -- Latitude, Longitude, and Height above sea level. Or you could describe your position relative to the room you're in -- measure the distance from the floor, left wall, and back wall, for instance. You could even measure your position relative to three points in space, and this is exactly how GPS satellites work! The important thing here is to note that two numbers aren't enough -- we need 3 numbers to give a useful description of a location.\n\nWhen we talk about things with \"more than three dimensions,\" we usually mean we're talking about things too complicated to describe with only three numbers. Spacetime is a common example, because if you want to identify an _event_ (like, say, a wedding), then you need to give at least three dimensions to identify the location, plus one dimension to identify the time. But it's quite possible to make other spaces which have more than three dimensions -- for instance, if a library database is indexed by Year, Subject, Author's Last Name, and Media Type, then it could take 4 numbers to identify a point in that database space. And there's no upper limit -- you can make \"search spaces\" like this as complicated as you like, requiring any number of dimensions to identify a location within them.\n\nWhen mathematicians talk about extra dimensions, they're often thinking about adapting existing mathematics to see how it would work in four or more spacial dimensions. For instance, we know that a line has 2 sides, a square has 4 sides, and a cube has 6 sides -- and we can prove that if there was a four-dimensional shape that fit this pattern (a \"tesseract\" or \"hypercube\"), then it would have 8 sides (and each side would be a cube, just like all 6 sides of a cube are squares).\n\nWhen ~~physicists~~ [string theorists] talk about extra dimensions, they're often thinking about how they could use additional types of measurement to better describe space. At very small scales, our space doesn't seem to obey \"normal\" three-dimensional laws -- so adding more dimensions is a way of getting more specific about what's going on at the ~~quantum~~ [subatomic] level, where ~~momentum and position~~ [some stuff I don't actually understand since I only studied undergrad mathematics] are tangled up in each other.\n\n**tl;dr: dimensions are just a thing we made up to describe how we measure things, there's no objective way to say how many the universe has, and if someone tells you to visualize all dimensions as branching structures then they've been watching too many time travel movies.** \n\n*Edit: Wow, this blew up, and many of you had great corrections. To be honest, I don't know what the hell physicists actually want out of extra dimensions, I only understand the math concepts.*\n\n*Also holy shit, it's over 9,000. Glad you all found this helpful! Remember, math isn't just for geniuses, it's for everyone who can read a book and ask a question!*\n\n*PS: If anyone's looking to hire a budding mathematician/aspiring programmer, please give me a call, with more experience I can write even more mind-blowing teachpieces.*",
"We live in a 3+1 universe ( what we observe ) so 1st and 2nd dimensionle objects are mainly concepts. \n\nAlthough I'm not sure about the concept of a singularity as I think that may be a 1 dimensional object due to the immense density. \n\nThe 11 dimensions of m theory is actually a 10+1 dimensional universe. Time would be referenced as the first dimension. I'm not sure what would exist in these higher dimensions but I know that anything more in the model of m theory compactifies down to 11 dimensions. \n\nString theory suggests a 26 dimensional universe.",
"I've read a good bit of this thread, and while i don't have much to contribute that hasn't really been said, I will add this.\n\nWhen referring to an additional dimension, too many people are saying \"this is the second or third or 9th dimension\". There is an important distinction to be made that u/ohballsman said. There is no such thing as THE third dimension. There is only A third dimension. They are all (more or less) indistinguishable once they are used to describe a system. My second dimension could be your first dimension. I.e. my y-axis could be your z-axis. My temporal dimension could be your 6th dimension. The labeling system should be indefinite because there is no fixed reference frame, frames are all relative to each other. ",
"OP this is the best, and most concise explanation I've seen in relation to this question.\n\nMinute Physics: There is no \"Fourth\" Dimention\n_URL_0_",
"I hate to be the guy that rains on the parade but I feel it is important to go a little beyond the question. The concept of higher dimensions (i.e. those beyond the traditional 3 spacial and 1 temporal) stem from a group of theories such as superstring theory and M-theory. These theories, while very popular with the general public, have not yet produced experimental evidence and as a result they remain very much theoretical (read:unproven). We should then be very clear that there is --as of yet-- no evidence that higher dimensions actually exist beyond the mathematics used in these theories.\n\nThere is a bit of a problem, and a debate among the scientific community, regarding how to talk about theories like superstring theory. On one hand, they are speculative with no experimental evidence to support them. On the other hand, that doesn't mean they are false. In time they will either be shown correct through experimental verification or discarded but in the meantime they have captivated the general public. \n\nThis creates a conflict. Popular science has always led to a problem where general audiences overestimate their understanding on scientific concepts often to the detriment of the actual scientific community. There are those that fear using these sorts of untested theories as essentially marketing material for science gives ammunition to those who wish to discredit scientific theories that they disagree with and creates a perceived acceptance of quasi- or pseudo-science. Alternatively,there are those that believe that because these theories manage to get younger and general audiences interested in science and this outweigh those potential risks. \n\nNonetheless, we must be clear that these theories (superstring theory and M-theory) are unverfied at any level. While they are interesting to discuss and potentially revolutionary if proven correct, they remain purely theoretical and should not be taken as fact.\n\n**TL;DR - It is difficult to ~~explain~~ describe the practical implications of higher dimensions because there is currently no evidence that higher dimensions exists beyond the mathematical models of superstring theory and its branch theories such as M-theory.**",
"If we're talking about spatial dimension, think of it this way:\n0 dimensions is simply a point in space. It cannot move.\n1 dimension is a line. In this dimension you could only move back and forth.\n2 dimensions would be like drawings on a piece of paper. If, somehow, you could live in this dimension, you could go forward, backward, left, and right, but not up or down.\n3 dimensions include up and down along with the other directions; the universe we live in is 3 dimensional. For reference to the fourth dimension, here's a scenario: You're a little shape, living on a piece of paper. You're in a room (made of just 4 lines as a square) with another shape. Remember that all you can see are other lines though. So now, imagine that you suddenly renembered \"Oh, there's a third dimension!\" and suddenly went up to get out of the room. To the other shape in the room, you would have simply just vanished, confusing him greatly. He can't see anything past his little 2 dimensional world, so he has no idea how to even comprehend how you got out of there.\n4 dimensions would work the same way: You're trapped in a cubic room with another person. There are no exits. Suddenly, he remembers the new direction that he can travel in, which would take him through multiple 3-dimensional spaces. All of a sudden, he just kind of warps into nothing, and is gone. You are now greatly confused because you can't imagine anything past 3 dimensional space, but to him it was a simple as you getting out of 2 dimensional space. The rest of the dimensions just keep working in that manner, with ways we can't even comprehend of moving through space.\nIt's really hard to understand, and I'm by no means an expert on this stuff, but that was the way it was explained to me and that's way I find easiest to explain to other people. Hope I helped a little! ",
"This might sound like a facetious answer, but bear with me, because it's genuinely a simple, ELI5 explanation of why physicists choose to talk about higher dimensions.\n\nImagine you have a math problem:\n\n > length * width * height * energy_used_per_second = total_energy\n\nWe make measurements of each (let's pretend most measurements were 1, for simplicity), and plug in the numbers:\n\n > 1 * 1 * 1 * 1 = 20\n\nThat can't be right! Why is it 20?! We measured all the numbers, and our formula CAN'T be wrong.... right? ;)\n\nLet's imagine ourselves up an answer using a newly invented input variable, because math is awesome:\n\n > 1 * 1 * 1 * 1 * x = 20\n\nWe know the rest of our input variables worked out at 1, right? So:\n\n > 20 / 1 = 20\n\nThere we have it: 20 is the value of our missing variable, x.\n\n\nCongratulations! We've discovered a new dimension that solves the fundamental physics problem we had! There is a new dimension, x, and we've already measured one of its possible values: 20!! Saints be praised.\n\n\nOr it could just be that our formula was wrong to begin with ;)\n\nEither of these ideas be true. Maybe there are \"x\", \"y\", \"z\", and other variables from these other hidden dimensions. But maybe there aren't. It's all theory for now.\n\n\nThe only dimensions we truly know of and experience (in some way***) are the first three \"spatial\" dimensions: length, height, depth (in any order you choose to list them really), and the temporal dimension, aka time. Together, they make the first four dimensions, aka \"spacetime\".\n\nThe first three are dimensions measured in \"planck lengths\", and the latter is a dimension measured in \"planck time\".\n\nAfter that, it's all just a solution to a big math problem: variables used to solve problems, not NECESSARILY actual definitions of the space we inhabit. Those variables MIGHT model the space we inhabit either exactly, very closely, or not at all.\n\n*** That's not to say that we experience \"absolute truth\" either.",
"Lets start with a point. A point has no dimension. Hell, it doesnt even have a definition. Euclid (a greek mathematician) defined a point as \"that which has no part\". A point can be used to point to a location in any dimension but it itself is partless. If it had \"parts\" it would be a line, surface, hypersurface? etc. \n\nNow, lets talk about the first dimension which is a line. When we put an infinite amount of points right next to each other, we get a line. We can use points to refer to a location on that line. Remember, a line only has length and no breadth or depth.\n\nFor the 2nd dimension, if we place an infinite number of lines next to each other, we would get a plane which would have length and breadth. For 3rd, put infinite planes to each other.\n\n4d is interesting. We know that if we put infinite number of 3d spaces next to each other, we would surely get 4d hyperspace. But its hard to visualize it. \n\nBut what i dont understand is how 'Time' is the 4th dimension. If we lived in a 2d world, time would still have existed as it exists now. But we know what 3D would look like if the world were 2D therefore, time definitely would not be the 3rd dimension for 2 dimensional world. Then why is Time the 4th dimension for us? Would the 4th dimension just be hyperspace? Therefore, time is something that just exists. We only know that time passes and its only because it passes that we exist. ",
"Try to think of a cube in 3d. At each corner you have 3 lines of axis (x, y, z) that are 90 degrees to each other.... Now, try to imagine a \"cube\" in 4d. It would have every corner with 4 lines of axis all at 90 degrees to each other. And so on and so forth",
"Maths:\n\n1) Line - a number is enough to find every spot\nIf you bend the line in a second direction, you get 1.x dimensions. The line gets longer, you need a bigger range of numbers to mark each spot. If you bend some more, the line covers a whole area. You can continue to use a larger and larger range of numbers along a complicated path, or\n\n2) Plane - you can add a second number to describe every spot much easier on 2 orthogonal straight lines.\nIf you bend, wobble, dent, or such the plane in a 3rd direction, you get 2.x dimensions. The plane gets larger, you need a bigger range of numbers to mark each spot. If you bend some more, the plane covers a whole space. You can continue to use a larger and larger range of numbers along a complicated path, or\n\n3) Volume - you can add a third number to describe every spot much easier on 3 orthogonal straight lines.\n\n4+) In the same way we get Hyperspace and Hypercubes, of as many dimensions as you want. By simply bending the given space in a new direction until the whole new direction is filled and every part has a direct neighbor in the new direction. Imagine 3d pictures of a dancer laid on top of each other and you have something close to a 4-dimensional object in your head. More is a little difficult to grasp, even if it's easy to understand the principle.\n\nPhysics:\n\n0) Let's get time out of the way first. Many refer to it as dimension 4. I prefer to see it as dimension 0. You can't go back in it, you move forward in it with everyone else, so one could say you are standing still. You can trick a little to make your own time appear faster or slower, so you age less or experience more, but you are still stuck. For time, giving it a dimension is mostly a convenient way to mark different events of the past, measure the present, and get ideas about the future. Though, as Einstein has taught us, it's a little bit more than that. In the end, time is change. And only one point of that 'dimension' exists where you are, at least from your own point of view. Unlike the other dimensions, along which you can move freely.\n\n1, 2, and 3) The normal 3 dimensions. 53.34810N, 6.26531W, 4th floor mark a location where you could meet someone. Forget one of the 3 numbers and your date might go wrong.\n\n0, 1, 2, and 3) Add a time, and you will be even more likely to meet.\n\n4) I'll leave it out - it would only cause confusion. That's what you get from sticking to your own system...\n\n5+) On our planet, we have no known place where more than 3 spatial dimensions would be of any meaning. Inhabitants of a neutron star might be luckier... However, it still makes sense if we go into the details. When you finally meet, how are you going to dress? Casual or Formal? Party or hanging out? For a long walk or for sitting in a theater? How are you going to greet each other? Hug? Kiss? Hand shake? Just a \"Hello\" or a nod? And so on. Each such 'flavor' can be described along a line forming another dimension. Some of them may truly be another dimension, others may turn out to be just a way for things to assemble in the given dimensions. Like love may just be our hormones.\n\nIn the world of physics, those 'flavors' would be any power which doesn't quite fit into simpler models.\n\nWe can model gravity by bending our 3d space. We can model electricity and magnetism in similar ways - and at a certain number of dimensions, the mathematics actually match our measurements quite well.\n\nTo explain this, let's see how content is calculated per dimension:\n\nA line is just X. A square's content is X * X. A cube is X * X * X. And so on.\n\nIf we draw this on piece of paper, the more X's there are, the more steepness increase in the curve which shows how much content there is for X.\n\nThings get interesting when we add those. Suddenly, we get more and more funny curves. Because curves with a lot of X's get steeper faster, they also start less steep. So instead of just more steepness, we get bumps.\n\nIf we divide 1 by those X's, we get curves which (usually) tend to grow closer and closer to zero (or a given number). The bumps are then closer to the starting point.\n\nThose curves look awfully close to what we get when we measure forces of something at different distances and draw the results of how strong the force is over a line showing the distance of the force.\n\nAnd here, gravity is close to formulas containing X * X, while magnetism is closer to the ones containing X * X * X. And there's many other forces.\n\nGravity looks like when you put a dent in a flat surface, except you have to add a dimension. Magnetism looks like when you glue something to a surface, and bend that something sideways, so you get a positive bump on one side and a negative one on the other. Similar for all other forces. These are geometric explanations.\n\nSome physicists hope to explain all the powers with different geometric models, and add another dimension whenever the given number doesn't explain all they can measure.\n\nHowever, other physicists prefer to stay with 3 dimensions, and instead of explaining the different powers, take them 'as is', just give each observation a different name, and add a new name for anything which doesn't fit yet.\n\nConsidering that anything smaller than an atom or with more than 3 dimensions is probably too strange for us, whose monkey brains are adapted to the macroscopic world we experience, it's probably ok if we let both continue - one to quickly get useful formulas, the other to understand the why one day in a far away future...\n",
"At a very low level, dimension is merely how many numbers we require to describe something. But geometry is more than just a set of numbers, there is an inherent structure to \"4-dimensional spacetime\" or \"11-dimensional m-theory\" that lies beyond just assigning 4 or 11 numbers to a point. Geometry is the collection of ordered n-lets and the set of allowable transformations that we can perform on those n-lets.\n\nFor instance, you could a grocery store by the price of all the objects in that grocery store. If x were the price of ham and y were the price of fish, and you perform the transformation x' = x cos(t) + y sin(t); and y' = y sin(t) - x cos(t) does that have any meaning? Not within the context of the supermarket. What if instead x, y described the x,y coordinates of the object, does this have any significance? In this context yes, the above transformation is a rotation of your coordinate axis about the origin. \n\nWhy can't we perform the rotation on the price of ham / fish? Because these numbers come from a very clear and real distinction between ham and fish. Where do the numbers in our description of the x,y coordinates of space come from? They come from somebody somewhere selecting a coordinate axis. There is nothing special about this coordinate axis, it is just a convenience for someone to be able to describe space using numbers. The geometry doesn't care what numbers we assign to its points, and as such our description of the geometry should reflect this. We describe geometry using not only ordered sets of n points derived from a particular coordinate axis, but every way that we can possibly transform our coordinate axis to get a new, equally-viable coordinate axis. ",
"I highly recommend [this](_URL_0_) book for people that really want to dive into the subject. It's a tough read, it's extremely hard at points, but my god is it interesting. I'm an Engineer, I love math, love science, and this book was a challenging read. I had to set it down at times, but you don't have to understand it all, because guess what - even the top scientists and mathematics don't understand it! It's an extremely awesome book.",
"As an actual physicist, I will summarize string theory with this meme:. \"Your theory can't be disproven if it makes no testable predictions\".\n\nString theory and its 11-dimensions is just an elaborate mathematical circle-jerk that's theoretically not forbidden (in terms of the laws of physics), however it's completely and utterly untestable, and is therefore useless.",
"I'm late to the party here, but if OP reads this, good enough. \n\nOne thing almost all of the posts on here are missing is the idea of orthogonality. In simple terms, this means that the dimension should be at \"right angles\" to each other. But more importantly, it means that the dimensions are not intertwined. You can fix all of them, and then change one without changing the others. For example, you could have a position in a 2-D plane and then change your z-value without changing your x-y position. You can change your time value without changing the xyz position. An object with a certain cross section in n-dimensions can be extruded to a solid in n+1 dimensions. "
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3m4cz6 | how can i always know where the north is? | This may sound like a weird question but since as long as I can remember I've always been able to know where the north is. Without looking I just "feel" it.
I can take the train or the car to an unknown city, go in a hotel room and I will know where the north is. I check with a compass on my smartphone and I'm right.
Is there any explanation to this? I've asked some friends and family and they all tell me it's not possible. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3m4cz6/eli5_how_can_i_always_know_where_the_north_is/ | {
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"They could always make a B-Movie super hero flick about you. It would be called \"NORTHMAN! I CAN TELL YOU WHERE THE POLAR BEARS ARE!!!\""
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6okfmf | if it's the amps that kills and not the volts, why are signs read" danger high voltage" and not "danger high amps" | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6okfmf/eli5if_its_the_amps_that_kills_and_not_the_volts/ | {
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"Because the voltage is what drives the current, and the voltage is likely a \"fixed\" value that will drive current through any load (i.e. Your body). The potential of the high voltage is what causes the danger...kind of like how the potential at heights warrants caution, even though it's hitting the ground that kills you.",
"\"It's not the volts, it's the amps\" is as useful a statement as \"jumping off the Golden Gate Bridge is harmless- it's hitting the water that does you in!\"\n\nIt's something that people say to have said it, to look smart.",
"Amps kill, but voltage is what attacks you. High voltage is more capable of arcing to you, overcoming the resistance of air or your skin. Amperage causes the damage. ",
"Aside form the \"current kills, not the voltage\" saying, there is also the fact that very high voltage is more prone to arcing. Following [ Paschen's law](_URL_0_) shows that the voltage needed to arc a 1-meter gap is about 3.4 MV.\n\n",
"Imagine the current and voltage as a bullet shot from a gun. Current is the size of the bullet, voltage is the speed at which it is shot.\r\rIf you have a high current potential (let's say a .50 caliber) but it is shot using a very small amount of propellant, the bullet cannot penetrate your body. It would just bounce off.\r\rNow, shoot that bullet again, this time using a good amount of propellant: the projectile now is really dangerous.\r\rYour body is a resistance. The bullet is the amount of current and the speed of that bullet, the voltage. More voltage for the same current and resistance, the more chances it have to penetrate your body."
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1vq3zn | why are certain television actors constantly listed as having a guest role, but have a major role in the series? | The best example I can give is how Marcia Wallace appeared in The Simpsons as Edna Krabappel 179 times, but was still credited as a guest star in every episode. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vq3zn/eli5_why_are_certain_television_actors_constantly/ | {
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"I assume because they aren't strictly speaking a regular character, or they don't show up every episode. Seems to have something to do with their contracts.",
"Typically it's contractual. If the actor isn't obligated to appear a specified number of times, then they are simply a guest stars"
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728mhm | what makes windows have the best gaming support, when macs and linuxes do not? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/728mhm/eli5_what_makes_windows_have_the_best_gaming/ | {
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"Windows is the computer operating system with the larges installation base so it is naturally that games are primary developed for windows and mac, linux in second case.\n\nThe support for games are good on all platforms. If they are available the are often identical. Look for example on steam for mac and linux games",
"I'd say DirectX inertia. \nDirectX as often opposed to OpenGl, is a set of high level libraries to make games (such as Direct3D or DirectInput, respetively, allow for 3D computing and controller management). \nIt is unfortunately only available on windows. \nBut opengl is as performant as DirectX is.",
"In the case of Mac, it goes way way back to the mid-1980s. Before Windows, Before DirectX, before even Steve Jobs got fired. The Apple II, while expensive, did have a very respectable game library, as well as strong developer support. Home computers were still largely a curiosity though. The real money was in enterprise, which IBM was dominating with their PC line. Despite Apple's \"fun\" reputation today, the Macintosh was originally geared to be more of a workstation. \n\nCorporate clients didn't want gaming capable computers, as games were seen as a potential productivity leach. To combat IBM, Apple strongly discouraged game development for the Macintosh platform, instead focusing heavily on software for businesses and creative professionals. The Macintosh was perfectly capable of playing games, but there was just no support for developers. Game development continued for the Apple II throughout the 80s, but comparatively few games were released for the Mac. The bulk of which being edutainment titles. \n\nNow the PC, the PC was modular, unlike the Mac. So while it didn't ship with gaming in mind, it could easily be upgraded into a gaming system. MS-DOS was also well understood by developers as well as users, where as MacOS was brand new, and as I mentioned, Apple had little in the way of game development support. \n\nPC gaming had a slow burn at the start, but the release of the AdLib and the VGA cards in the closing years of the 1980s really accelerated it as a major gaming platform. Which only picked up stream with important releases like Wolfenstein, Doom, and Quake in the 90s. \n\nThrough the 90s, Macs did start seeing improved game support. Especially through the PowerPC years. Pretty much every major PC release did see a MacOS port. It even saw its own major exclusive, Bungie's Marathon series, the spiritual predecessor to Halo. Releases were still few and far between though. \n\nBy this point, Apple had solidified themselves as a productivity focused brand. Which continues right up to this day. Apple has never released a gaming focused Mac. Instead the company has chosen to focus their resources on mobile gaming, with the iPhone long being the best supported and most powerful mobile gaming platform.\n\nAs for Linux, it's user base is too small and fragmented to make gaming really viable. It's also primarily used for productivity and embedded systems. While gaming is not common on desktops, Linux has seen strong gaming support on mobile devices. Android runs on the Linux Kernel after all. The PS4 also runs on the BSD kernel, which is a (very) distant cousin of Linux (they're both Unix-like). Mac OS X and iOS are also BSD based. So it's not that these operating systems can't game, and they do if there's a large enough market. "
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y4b6t | kim il sung's "juche idea" | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/y4b6t/eli5_kim_il_sungs_juche_idea/ | {
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"Juche is at its core \"Self Reliance\" which urges people of the DPRK to use the resources of their country and their people to become prosperous without relying on or being influenced by others. To retain these resources your country needs a strong military to keep outsiders at bay.\n\nThese tenets are summarized by Kim Il Sung as:\n\n1. The people must have independence in thought and politics, economic self-sufficiency, and self-reliance in defense.\n2. Policy must reflect the will and aspirations of the masses and employ them fully in revolution and construction.\n3. Methods of revolution and construction must be suitable to the situation of the country.\n4. The most important work of revolution and construction is molding people ideologically as communists and mobilizing them to constructive action."
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3v4dti | with people constantly giving billions to charity & with zuckerberg announcing their donation of ~$45bn why aren't charities achieving their goals? | For example, cancer research charities are receiving so much money everyday but we don't hear about what progress was made as a result of the massive amounts of money they receive.
Call me ambitious but i'd expect cures to be coming out left right and centre with the amount of investment that goes into these things.
Not just cancer charities, there are many others.
Bad example possibly? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3v4dti/eli5_with_people_constantly_giving_billions_to/ | {
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"Cancer isn't one disease, and no one treatment will work for every type of cancer no even for every person with the same type of cancer. It's vastly complex and will never be solved overnight - but because of the research, your chances of surviving cancer right now are vastly better than they have ever been, and continue to improve.\n\nAs for charities for social issues (such as poverty), they totally are reaching their goals. Literacy is up world wide, infant mortality is down and, with only a couple exceptions, world wide violence is down.\n\nWe currently live in the best time to have ever been alive, morally and medically. It just doesn't seem that way sometimes because we're always looking to improve, to do better things, and you know what - that's a good thing.",
"Some charities are in the **business** of being a charity. What I mean by this is that raising money has become big business often separated from the good causes they support. The fundraiser never works in the science lab doing the research and you will not see the scientist shaking a donation tin. The fundraisers are sometimes volunteers but are often paid. Companies subcontract to a charity, they are not doing this out of the goodness of their heart but because of cold hard cash. This is just another job to many of the people involved.\n\n\n",
"There used to be charities fighting against smallpox. Then smallpox was eradicated. Now you don't hear about charities fighting against smallpox anymore, because they achieved their goals. \n\nThe successful charity isn't going to spend a bunch of money to tell you that they don't need your money anymore. That's up to you to observe on your own.",
"Let me rephrase your question in a few ways.\n\n1. \"Why do i hear less good news than bad news?\" First off, there is lots of success out there, but that doesnt sell papers. A shooting makes front page, a kid returning to his old school to mentor kids away from violence maybe gets a tiny article in the weekend edition. As someone who has tried, it is hard to get anyones attention with good news. Pick something you are interested in, join some mailing lists, and you'll hear some success.\n\n2. \"With all the money we have spent on gas over the years, why aren't we there? Id have thought we would have all reached our destination.\" Lots of charities are filling gaps in society for those individuals moving through those gaps at any given time. As long as there is poverty and there are kids, there are going to be kids in poverty needing after school programs. The educational charity providing that can't stop the conditions leading to it, but they are still vital in the lives of those kids experiencing it. You get one group of kids college bound, and there is a new group of kindergarteners waiting.\n\n3. \"With all the progress in diplomacy/weapons why is there still war?\" This is your diseases example. We (meaning humans) actually have done a lot to minimize war. You are less likely to be killed by another human than at any time in history. But there are lots of causes and types of conflict, so it is a long, ongoing work in progress. Curing diseases is a long, expensive process, and many diseases have multiple forms. Survivor rates for most diseases is up, vacines against hpv can help lessen risks of cervical cancer, etc.\n\nTldr: most charities either have big enough goals that success is long term or success leaves them free to focus on another problem; or they are alleviating the effects on individuals of larger ongoing societal ills. And you aren't hearing about the success because you the news won't being it to you and you arent looking hard enough yourself. \n\n"
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8o4yip | especially in the winter when there's snow on the ground, why does everything have a blue hue to it just before sunrise and sunset? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8o4yip/eli5_especially_in_the_winter_when_theres_snow_on/ | {
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"Blue travels at the shortest wavelength and is scattered the most, which is why the sky is ‘blue’. I’d imagine it’s mostly the same thing, but factoring the reflective surface from a pure “white” substance like snow. Not totally sure just seems like it makes sense. ",
"It will depend not only on the elevation of the sun, but also on weather conditions, pollution, particles in suspension, etc.\n\nIt's an optical illusion. Just like the Green Flash on the Pacific Ocean in San Diego or the orange and purple sunsets of Arizona.",
"Light diffuses (understand deviated) when propagating in the air. How much it diffuses depends on the wavelength (its color).\n\nThe sun emits a wide array or wavelength, and its \"blue rays\" are among the most disrupted by air. That is why the sky by day is blue. They are so much deviated that they look like coming from where the sun is not, giving the sky its opaque blue look. (Imagine air particles acting like tiny mirrors in random directions, reflecting only blue light)\n\nNow imagine the sun being slightly beyond horizon. Rays that makes the light look \"white\" are for the most part not reaching you. Except blue ones. \nAs they are redirected by diffraction, they reach places the other ones do not have a direct path yet/anymore. That is why before dawn/after dusk everything is blue-ish. (Snow only makes it more noticeable because it's white.)",
"Air is made of little balls called molecules, which are made of smaller balls called atoms.\n\nNow, light can interact with molecules (really the atoms) in 3 primary ways: reflection (like a mirror), refraction (like how light is bent when looking from air into water) and diffusion, aka scattering.\n\nDiffusion is similar to reflection, but instead of reflecting the light in a single direction, it scatters it in every direction. It's the interaction we are most used to, nearly all materials scatter light. It's why a piece of paper is white, no matter what angle you look at it from. The light doesn't need to reflect into your eye, because the paper scatters the light in every direction.\n\nGasses can scatter light too, though! Both oxygen and nitrogen, which make up a lot of the air, are good at scattering blue light. The sun appears yellow (and not white) because some of the blue gets scattered as it passes through the air, and the yellows, reds, oranges, etc all keep travelling straight, until they hit your eye.\n\nThis blue scattering makes the rest of the sky is blue, and this causes the sky to be blue.\n\nNow to answer your question: as the sun rises and sets, there aren't as many reds/yellows/oranges as the sun isn't shining as intensly down, it needs to travel through a LOT of air to get to you since it's coming in from an angle. This means that a lot more blue light gets to you and the surrounding area. And when there's snow on the ground, snow reflects every color (since it's white), and since there's not as much of the reds/yellows/oranges, it scatters even more blue.\n\n\nEDITS: changed a couple \"diffusions\" into \"scattering\" to be consistent and understandable. Also changed a typo of \"matter\" to \"water\" (in refraction)",
"Why, especially right after a snowfall, does Winter's night sky take on an oddly rosy pink hue?",
"Imagine a herd of animals running through a really rocky field. These are special animals that come in all different colors and what color they are determines how far they can jump. The redder animals can jump really far while the bluer ones can only jump a little. So as they run through the field the red animals are able to jump over most of the rocks while the blue animals keep bumping into them and getting knocked off course. \n\nThe animals represent what are called photons. These are little bits of lights and like our herd of animals, the light is made up of photons of all different colors. The field is the air. While we can't see them with our eyes, the air is really made up of tiny little particles called atoms. These atoms are our rocks. Just like the animals, some photons are better at getting around them than others. Blue is not very good at getting around the rocks so they tend to cause blue photons to get bumped around and as a result we see more of it in certain cases. ",
"The sky is blue. At dawn and dusk more light hits the snow/ground from there than light directly from the sun. ",
"The human eye can see colour in the form of visible light, based on the electromagnetic radiation wavelengths (ie: frequencies. Think like microwaves, radio waves, etc.) an object gives off.\n\nThe temperature of the object and the lighting applied to/surrounding the object are what affects the colour that we see.\n\nA red object emits the longest wavelength at the highest temperature.\n\nA violet object emits the shortest at the lowest temperature.\n\nUltra violet and Infrared cannot be seen by the human eye, which is why we use special technology to see it.\n\nA black object emits no radiation wavelengths.\n\nA white object emits ALL of the wavelengths.\n\nAlthough Snow is white, white objects tend to absorb the \"red wavelengths\" and give off a blue tint in certain lighting.\n\nThe same principle works for light bulbs (which is how I learned about this... electrical apprenticeship).\n\nStores with certain products on display use specific types of bulbs, to make their products appear a specific colour, etc.\n"
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770gw0 | mao zedong massacred more people than hitler & stalin **combined** but rather than being condemned he is praised, how come? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/770gw0/eli5mao_zedong_massacred_more_people_than_hitler/ | {
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"I'm surprised that you would say he is praised. Even the communist party in china rejects Maoism. ",
"I think that a lot of people in Western countries don't have a lot of knowledge about Chinese history in the way they do about German or Russian history. Personal experiences of WWII that many of us heard also don't really cover the impact of the war or the communists on China as a whole, while the did shine a spotlight on the mass-killings by Nazi Germany, Soviet Russia, and Imperial Japan. \n\nI think a reason people aren't really taught much about this may have to do with the ideological leanings of many within the academic class in the US and Europe, which have significant Marxist sympathies. \n\nHowever, I should point out an important difference between the way that mass death under the Nazis and Soviets was different than that in Maoist China. Many of those deaths happened during a period known as the Great Leap Forward, where Mao implemented policies of agricultural collectivization and forced industrialization. This resulted in the Great Chinese Famine. This famine is estimated to have lead to the deaths of between 18-55 million Chinese. While these deaths should be attributed to the failed policies of the Mao regime, they were not targeted to the same extent as the holocaust or the mass murders committed by the Soviets. Deaths by violence under this period are only estimated around 1 million Chinese. As groups were not actively targeted by the death, the failure to respond to famine is likely justified more as \"negligence\" than \"murder\". ",
"I don't want to downplay the millions upon millions of deaths due to Mao, or the importance of racist historiography in comparing Chinese and European history. But I do think we ought to distinguish between deliberately trying to kill millions of people (Hitler), and *inadvertently* killing millions through bad policy, blind adherence to dogma, and willful ignorance, which is where most (but not all!) of Mao's body count comes from. (Stalin, IMO, is somewhere in between.)\n\nIt's the difference between murder and manslaughter. Not that it matters to the victims, they're dead either way, but we shouldn't judge the leaders' evil strictly by body count."
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2h5wfm | how oil prices have been low since june 2014 | After 2003, oil prices have been steadily rising.^[1](_URL_2_) ^[2](_URL_1_).
But right now, after ISIS started becoming stronger and went on the blitz through East Syria and West Iraq, why aren't the prices rising?
[This NPR story](_URL_4_) seems to boil it down to supply and demand, which is looking absurd to me because the supply of oil is controlled by a cartel that hasn't hesitated to [arbitrarily increase the price before](_URL_0_)
Why aren't the prices shooting up? [This map](_URL_3_) shows where the oil is - in Iraqi Kurdistan. Isn't that enough to freak the markets out (as *they've always had a propensity to be*) and make oil prices jump to about $150/160 a barrel?
Is there something I'm missing here? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2h5wfm/eli5_how_oil_prices_have_been_low_since_june_2014/ | {
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"You can tell how much excess supply is in North America by looking at the spread between two benchmarks, West Texas Intermediate and Brent crude. Big spread equals excess supply in n america. Hence the push for new pipelines in n America for transport to waterways, xl pipeline. \n\nDemandwise, the global economy is growing terribly slow vis a vis 2000-2012. Emerging economies are weak and China continuing growth is a possible question mark. Europe is entering a triple dip recession and Japan is weak too. The us is growing ok but slow as well. It has to do with an end to the US - China growth model of excess consumption and housing investment financed with excess Chinese savings, typically referred to as Bretton woods 2. \n1990s had weak global growth too, oil was under 10 bux a Barrell in 1999. Pretty simple dynamics. Expect oil prices to continue falling or staying flattish for many years.",
"Oh, and oil isn't really controlled by a cartel. The share of non open oil supply continues to grow. As people note, n american crude output is growing a ton. And Saudi Arabia itself controls enough marginal supply that they can really cool off prices just by growing investment. As long as they continue investment, prices stay cool. Maximizing the price of oil isn't always the kingdom's main goal. ",
"Oil markets aren't as jumpy as they used to be. Production from US shale plays has helped to ease the supply concerns stemming from geopolitical tensions. Even with Iraq/Syria/Libya all having violent conflict, the extra oil coming from the US has helped to mitigate the effects of the unrest in that part of the world. \n \n\nThe shale boom really is the real deal. [Look at the plot of US production over the last few years](_URL_0_) In 2005 we were producing 8.3 million barrels per day. In 2013 that number was 12.3 million barrels per day. Iraq, on the other hand, produced just [1.3 million barrels per day in 2005 and 3.1 million per day in 2013](_URL_1_). That almost 4 million extra barrels per day relative to the oil production of these areas is significant enough to help ease supply concerns. \n\n\n\nDemand is the other half, which I think the article clearly explains. "
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2dsupr | why does it seem like there are more single men than single women? | Assuming there are about the same number of heterosexual men and women, and that every relationship has one of each, why does it *seem* like women have choices between many different men who are competing with each other? And why are there more men who would like to be in relationships but aren't?
I'm a man so I'm perfectly open to the idea that it only seems this way because I'm biased, but it has always seemed like women are "sellers" and men are "buyers" in the dating market. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2dsupr/eli5_why_does_it_seem_like_there_are_more_single/ | {
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"You answered your own question. If you asked any single woman in your town no doubt she would complain about the exact opposite situation.\n\nThat said, there are some cities in the US, mostly in the west, where there are more single men than women. [map](_URL_0_)",
"cultural perception, not based on reality. women actually modestly outnumber men.",
"I think single men are just more visible than single women. When a single man and a single woman have a child, usually the woman ends up with the majority of parental duties. Taking care of a child takes up most of the free time a single woman would have for dating. A man is more likely to have time and energy to spend Saturday nights going on dates and pursuing a relationship. A woman is more likely to have a child in her care that needs her time and energy.",
"I had a theory.... The increase in obesity has led to a much smaller dating market for american men. Fatter men can sometimes get by on personality or wealth but obese women can't. Obese men can wear the weight better and still be considered attractive unlike obese women.\n\nFor example, assuming 10-20% of young single, women are ham planet territory, that obviously removes 10-20% of the market if obese women ain't your preference.\n\nSo assuming your a guy who is somewhat picky and won't date a ham planet or thin but ugly women....your odds go down significantly.\n\nAlso, I think older, single women aren't proud of the fact and don't announce it like a guy usually. Less stigma for a older bachelor than a women.\n\nLastly, shy women can gets date much easier online or in random places. Shy men even if tall and attractive can easily be single. ",
"I'd guess it's partially because men are more noticeable when they're single and looking for someone, since on the whole they have to take a more active role and put themselves out there. \n\nThere are way more men on dating sites. If you go a nightclub it's easy to spot all the guys who are on the prowl. If you go to a mixed-gender social meet up you can clearly tell which guys are ignoring everyone else and trying to chat up one woman after the other. \n\nSingle women blend in more, and you don't really know their status unless they talk about it. ",
"I think you're just viewing it biasly. As a married man I can see it pretty objectively, and I see just as many if not more women complaining about being lonely than I do men.",
"i bet that it's not so much that you are biased as a thinker as much as there's selection bias in your representative sample due to that fact that you are male and that most of your friends are guys \n\ntherefore your sample, even if reasonably large, does not represent the population without bias",
"I wonder how much of this is innate and biological, and how much is cultural. For instance, the commercial way of thinking of people as \"buyers and sellers\" seems to me like imposing man-made economic categories on nature, artificial rather than natural. ",
"Because everybody wants shit they can't have. There are plenty of single girls you will never see even when they are right in front of your face. What you really mean is why don't all the hot girls u see want you.\r\rThe jealousy answers a lot of that question I'm no great looker but I've done well on the gf front many of my better looking friends struggle because they hold themselves to unobtainable standards",
" > it has always seemed like women are \"sellers\" and men are \"buyers\" in the dating market.\n\nthis is it exactly and there was [a really good post explaining it a few months ago](_URL_0_)\n\nexcerpt:\n\n > Economics teaches us that the more plentiful a resource is then the less value it has. Women are taught to not desire sex because if they did it would make sex from men more valuable and the sex woman offer less valuable. This is why \"slut-shaming\" is even a thing. A women who is seen to freely \"give\" sex is devaluing the resource as a whole. Why would men give up resources for a commodity that is being offered for free by someone else? Would you still pay for milk if there was a cow in the center of town that just anyone could use? ",
"There are plenty of single women, but they either aren't in your social circles because they don't have a boyfriend, or don't register on your sexual radar.",
"Because men tend to bitch about / make you aware of them being single more than women do.",
"As someone who's bi and polyamorous, I find this thread interesting. It's a question I haven't thought about in these terms in many years, and I can tell you that the existence of people like me probably skews things now.\n\n > Assuming there are about the same number of heterosexual men and women, and that every relationship has one of each\n\nFor instance, I currently have 3 female partners, who in turn each have several other partners of both sexes, and on and on -- which when you add it up probably takes a significant number of people out of the dating pool, if you're only looking for heterosexual monogamy.\n\nEdit: Of course, this is only relevant to your question in whether it skews the dating pool by sex. I'm not sure whether it does as a whole, but in my immediate area of it, there seem to be more females than males involved in poly. I could see this causing localized skews in various dating pools, and the reduction in heterosexual monogamous people might slightly thin the pools in general, making singles seem scarcer to both sexes.",
"Confirmation bias. \n\n/thread",
"The lonely plain gal in the corner isn't as noticeable as the hot gal getting flocked around. ",
"Because involuntarily single men exist as a well-established cultural thing - it's not an ideal state, but it's legitimate. Single men have stories made about them all the time, and get lots of attention. Involuntarily single women are invisible, period.\n\nWhen people compare \"men\" with \"women\" in a romantic/dating context, most of the time they implicitly compare \"all men\" with \"attractive women\".",
"The Economics of Sex: _URL_0_\n\nShown to me by my SOC 100 professor. ",
"I think you're biased, but not the way you think. There are plenty of single women, they're just not showing up on your radar because you don't consider them attractive. Pop culture has this weird way of portraying men of various levels of attractiveness (physically, economically, personality-wise, etc.) but only fairly-very attractive women. A large array of men will show interest in an attractive woman, making it seem like there are more men searching than woman. In reality there are plenty of women, but men aren't interested in them. ",
"Biologically, there's the whole basis of sperm being ridiculously cheap and easy to come by at the rate of millions per hour versus the one egg per month for a limited time. So it is naturally the role of males to compete for the scarcer resource that is a female, and it is the role of the female to sit back and be extremely critical and selective of what she is willing to accept (more like an employer in a labor market than the buyer and seller analogy). \n\nThis very basic truth is responsible for an incomprehensible amount of what we experience in life. If any woman is alone (and I seriously mean even those one might judge to be 'objectively' the least desirable), it's because she *chooses* to be (far and away the most common reason being that she feels she deserves better than what is readily available, preferring not to 'hire' anyone given only under qualified applicants from which to pick). \n\nBy contrast, of the population of single men, very few are voluntarily alone (and the vast majority of them are only so out of frustration after being fed up with the unfairness of the game favoring women; if they are not able to accept giving up they will go gay eventually).\n \nJust like in more primitive times the winning males would kill the weaker ones and mate with many willing females, today the successful guys generally have their pick and the women who are not pursued by these relatively more successful males have to then either lower their standards or remain single (poor options, but a choice nonetheless). \n\nFor men at the bottom of the pecking order though, their only chance is catching someone who doesn't yet fully realize how low his status is; should he even be THAT LUCKY, it's then a matter of running out the clock and getting that ignorance to last, though eventually most women will catch on and then *chose* to either end the relationship or suffer through it resentfully due to practical considerations. ",
"I would think partly due to the fact that you're only considering women that you find attractive, and all men -- either attractive or not.\n\nAssuming your find the average woman attractive, you're comparing 50% of the population (average attractive woman and above) to a much greater percentage of the male population (90+ %)."
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3ygkuc | why are there so few horror television shows? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ygkuc/eli5_why_are_there_so_few_horror_television_shows/ | {
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"I guess it's hard to compete with the News! \n\nBut generally speaking, as someone who works in visual effects for film and telly, a lot of it has to do with getting things past the ratings advisors. Starz! tends to be one of those network carriers of shows that would otherwise be considered too extreme."
]
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7h21aq | from a practical, material viewpoint, what could an average person with no special skills or available resources except time do make the world a better place for everyone to live in? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7h21aq/eli5_from_a_practical_material_viewpoint_what/ | {
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"A better place for everyone is a bit difficult, but a better place for some is easy. Plenty of volunteer positions everywhere that won't need a lot of skill. If you really want to share the wealth though, you could do something like litter clean up. That certainly benefits everyone.",
"Speak up for the good causes in the world. Speak out against people taking advantage of others. Provide accurate information on what can be a murky/devisive topics. \n\nI am not saying to rail against every little hurt feeling, to be clear. Help keep the focus on injustices with widespread ramifications, even if it's just letting someone know (civilly) they're reposting fake, intentionally inflammatory news on facebook. In contrast, when people do the right thing, lift them up for that.\n\nTl;dr: Open up beneficial lines of communication with those around you.",
"Plant trees. Don't litter. Don't be bitter, be nice to everyone even though they might not be to you. Volunteer, not only will this get you some connections and a generally happier life but it might give you some skills you didn't have before. Like if you volunteer for construction works. "
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60yk92 | - what happens when your fever breaks? | My daughter recently had a fever. When it broke she was covered in sweat. It got me to wondering what happens to your body when a fever breaks. Obviously the sweat is your body saying "go ahead and cool down" but what else is happening? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/60yk92/eli5_what_happens_when_your_fever_breaks/ | {
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"Language sucks. Typically the term \"break\" here means the fever goes away. If your fever breaks, then you no longer have a fever. On the other hand, if you \"break-out\" in hives or \"break-out in sweat, that means you START having hives or sweating. Likewise, \"didn't break a sweat\" means you didn't sweat. Language sucks. \n\nANYWAY, fevers. \n\nThe hypothalamus is part of the brain that controls the thermometer. It tells the skin how much to sweat and also controls some duct-work to bring heat this way or that. When your body has an infection one of the ways it tries to fix it is hypothalamus ramps up the thermometer sends more heat inward to try and bake it out. A lot of those bad bugs expect normal body temperatures of 98.6 degrees, and will die at 100 degrees. Or hotter. Or not. But your body is trying to kill off the bad bugs with the downside that it also might not be so healthy for itself. \n\nYour skin has a means of dealing with being too hot. If you get too hot your sweat glands will put out some moisture to try and cool you off. Like tiny little firemen dousing a fire. ....I don't know how much the hypothalamus coordinates the sweat-glans to hold off dousing the fire while it tries to bake out the bugs. I'm always pretty sweaty the entire duration of a fever, but it'd make sense if it held off and then rushed to cool itself off once the bake-cycle is done.\n\n\n\n"
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1j99z5 | why was there such a stigma surrounding masturbation in many ancient (and current) societies? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1j99z5/eli5_why_was_there_such_a_stigma_surrounding/ | {
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"Sex is usually considered a sacred act, as it is is required to make new people. This is why sex is usually promoted as a \"wait until marriage\" kind of thing, such as to promote the creation of families and hence continue the human species. Since masturbation is usually purely for personal pleasure and not engaged in to reproduce, it is considered a sin as it violates the sanctity of sex, which involves two people. \n\nInterestingly a creation myth of ancient Egypt involved the creator god ejaculating into his own hand, swallowing it, then spitting it out in the magically created forms of his children. "
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5u6vpf | how large could an alien be? theoretical science/biology question. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5u6vpf/eli5_how_large_could_an_alien_be_theoretical/ | {
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"theoretically there doesn't seem to be a limit to how big a body can be. \nBut a lifeform would also need an enviroment in which it could live, so it would need to fit in any given atmosphere of a life supporting planet.\n\nif we are observing the life we have on earth, we already have big differences in body size from microscopic lifeforms up to whales, which is far more then 2000 times bigger. ",
"I can't give you an exact answer, but I can start to get you thinking about some of the things that limit the size of organisms on Earth, and how these limits may also apply elsewhere. A bit of googling found [this](_URL_1_) page which has a lot of useful information.\n\nOne major limitation is simple mechanical support. On land, legs need to be strong enough to support body weight and move around. However, for a given body plan, weight scales according to volume while the strength of legs scales according to their cross-sectional area. Thus as you get bigger, you need relatively thicker legs (in proportion to your body size) in order to support your weight. \n\nHow might this be different elsewhere? Well, for a start the strength of gravity might be different - with reduced gravity, you could grow bigger using materials of comparable strength. Or it's possible that the aliens' biology means that their 'skeleton' is made of something much stronger than bone.\n\nAnother limitation is the need to supply all of the cells in your body with oxygen (or whatever the alien uses instead). One of the reasons that we can grow much bigger than insects (and other arthropods) is that we have a dedicated respiratory and circulatory system, where as arthropods rely primarily on diffusion - their whole body is linked through trachea which are simply pipes connected to the air outside, and air simply diffuses through these tubes (although some species can 'pump' their whole bodies to help this process). [It has been speculated](_URL_0_) that one of the reasons that insects grew larger in the past is that higher oxygen concentrations meant that they could achieve larger body sizes before this became a limitation. But even in organisms with respiratory and circulatory systems, the need to make sure that these systems can supply the whole body is a limitation.\n\nWhat are the consequences of this for alien life? Clearly it would depend on both the composition of the atmosphere in which they live, and also the alien's own metabolic processes.\n\nFinally, one thing to consider is what form of life the alien is. Most of the above applies to animal-like aliens (which obviously make the most useful movie characters) but alien life might not be at all comparable. The [largest living organism on earth](_URL_2_) is thought to be a giant fungus, which covers an area of 3.7 square miles. So even here on earth, we have living things that are thousands of times larger than us!"
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abxhln | different regions of american barbecue? | Can anyone explain how Texas BBQ is different from KC or Carolina BBQ? And any other major regions I’m missing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/abxhln/eli5_different_regions_of_american_barbecue/ | {
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"Carolina BBQ is pork and (to a far lesser extent) chicken. It comes in a variety of styles, but perhaps the most famous is Eastern Carolina, which has a thin, vinegar-based pepper sauce that can act either as a mop (applied while cooking) or finishing sauce (applied as a condiment). Western Carolina, or Lexington, has a thicker tomato-based sauce.\n\n\nTexas is all about beef. Particularly brisket. It's delicious.\n\n\nKC style is usually ribs or chicken made with a sweeter molasses-based sauce.\n\n\nAlabama style is known for it's distinctive white sauce.\n\n\nOther areas in the Southeast use a mustard-based sauce. I've heard this referred to as Tennessee, Virginia, Georgia, and South Carolina style from different sources so maybe someone can elaborate on this.\n\n",
"The four major regions are Memphis, Carolinas, Kansas City, and Texas.\n\nCarolinas - vinegar based sauce, focus on pork. South Carolina has a regional variant that is a mustard sauce.\n\nKansas City - sweet sauce. Most generic “barbecue sauce” is based on this.\n\nTexas - a little spicy and a little sweet, slow-cooked beef and pork.\n\nMemphis - either a spice rub (dry) or a tomato-based sauce (wet)."
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3fbmjm | why can't we harness the ocean for energy? | I recently went to the California coast and the waves on the shore were so powerful, they would knock you off your feet.
The amount of energy in these waves is staggering. Why aren't we harnessing more of it for energy? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3fbmjm/eli5why_cant_we_harness_the_ocean_for_energy/ | {
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"because \n\n1. waves don't happen all the time.\n2. waves don't happen at the same location.\n3. there's no way to control the power output either.\n4. it's expensive to build something to harness this energy.\n5. because of the above, doing so is not efficient, so we don't.",
"We're working on it. The tech just isn't quite there yet. _URL_0_"
]
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df5vz2 | how can $1 usd have more buying power in other countries than in the us? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/df5vz2/eli5_how_can_1_usd_have_more_buying_power_in/ | {
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"1) The cost of labor. Most countries in the world have a lower standard of living than America, so $1 can buy a lot more in services, and also it means less overhead on products that are sold.\n\n2) Taxes, both direct like sales taxes, and behind the scenes. Developing countries don't have as much in taxes, so a product or service can be sold without as much overhead again.",
"The same way bottle of water is more expensive in a desert/amusement park vs a lake/your home.",
"Mostly it depends on the economy of the other country and how you define \"buying power\". In most cases, the way economist measure buying power is for equivalent not identical goods. So if food, for example, is generally cheaper in the other country relative to the US, then $1 will have more \"food buying power\" in that country than in the US. Extend that concept and you get an idea why $1 has a lot more buying power in countries with generally lower cost of living."
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3640s8 | with public water does it really matter if i conserve water at the sink and shower faucet? won't it just re-enter the water supply? | My wife and friends are all about getting low flow shower heads and not letting the water run too long. Other than the few dollars I might save on my water bill, does it really matter environmentally?
The water will just re-enter the public water system with no loss. I don't see how it's environmentally beneficial to save water in this way. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3640s8/eli5_with_public_water_does_it_really_matter_if_i/ | {
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"Regardless of if the water was used or just put straight back down the drain, it undergoes the same filtration and decontamination process as \"dirty\" water, which requires time, energy, and money.",
"It doesn't really matter environmentally because not much water gets used there. [Here's an analysis](_URL_0_). If you want to save water, you're better off changing what food you eat. Cows eat a lot of alfalfa, and alfalfa takes a lot of water, so eat less meat. I'm sure if you look it up, you could also do a lot with which meat you eat.\n\nEdit: Actually I think it's the dairy cows that eat alfalfa. I don't really care that much about conserving water, so I haven't looked into it much."
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86sflu | sneezing under the sun | Why are our noses suddenly triggered and we end up sneezing when we move from a cold to a hot place (e.g. from an air-conditioned room to the sunny outdoors)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/86sflu/eli5_sneezing_under_the_sun/ | {
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"I’m no expert, but I have experienced this enough that I did a boatload of research a few years ago. Short answer: we don’t know, but it’s something about the sudden temperature change when you go under the sun. It’s actually an active area of research, though, because it presents a danger to fighter pilots/test pilots and the like (not a good idea to have to shut your eyes suddenly due to a sneeze when you’re breaking the sound barrier up in the stratosphere)",
"There is something called the photic reflex that 25% of the population has. The sun makes you sneeze. I have it and my husband thinks I am weird, lol. "
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6dbbrl | why does rabies virus cause photophobia in people but in raccoons it makes them come out during the day? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6dbbrl/eli5_why_does_rabies_virus_cause_photophobia_in/ | {
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"The rabies virus is pretty interesting. The viral particles take hold in nervous tissue and then start a slow ascension from peripheral nerves to central nervous system, the brain and then finally down through some of the nerves that innervate face (namely nerves that innervate salivary glands). \n\nThe virus isn't perfect - it isn't omniscient and it often doesn't know exactly which way to go depending on what host it's living in. Different species have different incubation periods. That's why some animals (bats, skunks, raccoons) are considered reservoirs for the disease. The virus moves very slowly throughout their nervous system allowing them more time to spread the disease before the clinical progression puts them 6 ft under. Other species (like us) have a much shorter survival time following the onset of symptoms. \n\nPhotophobia isn't really a desired affect for the virus. More likely, it's just a wrong turn in an aberrant species. But the furious portion of the disease (aka - desire to bite), just like the inability to swallow (thereby reducing the amount of virus-ridden saliva swallowed and wasted) are considered \"features\" of the disease to help it spread. So when those raccoons be a wanderin... they're out to kick ass and chew bubble gum. And the virus won't allow them any bubble gum. \n\nSource: I watch a lot of zombie movies."
]
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6wzi3t | why is marijuana so demonized, but not other stimulants that impair people to drive just as much, such as alcohol, antidepressants, etc? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6wzi3t/eli5_why_is_marijuana_so_demonized_but_not_other/ | {
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"Marijuana and alcohol are not stimulants.\n\nBut to answer your question: this policy was aggressively pushed in the USA, especially by the Nixon administration, because African Americans at the time were greater users of marijuana than whites, and certain politicians were looking for ways to oppress them. I'm sad to say it, but there's lots of historical evidence.",
"tl;dr Nixon's enemies were anti-Vietnam and black people so by associating weed with those communities and then making it illegal, it disrupted those communities\n\n > One of Richard Nixon's top advisers and a key figure in the Watergate scandal said the war on drugs was created as a political tool to fight blacks and hippies, according to a 22-year-old interview recently published in Harper's Magazine.\n\n > \"The Nixon campaign in 1968, and the Nixon White House after that, had two enemies: the antiwar left and black people,\" former Nixon domestic policy chief John Ehrlichman told Harper's writer Dan Baum for the April cover story published Tuesday.\n\n > \"You understand what I'm saying? We knew we couldn't make it illegal to be either against the war or black, but by getting the public to associate the hippies with marijuana and blacks with heroin. And then criminalizing both heavily, we could disrupt those communities,\" Ehrlichman said. \"We could arrest their leaders. raid their homes, break up their meetings, and vilify them night after night on the evening news. Did we know we were lying about the drugs? Of course we did.\"\n\n[Source](_URL_0_)\n\n",
"Ah, found the [link](_URL_0_) this explains how it became illegal, and to keep it illegal, propaganda campaigns made it out to be 'evil' \n\nWilliam Randolph Hearst. < --- this guy. He preferred to cut down forests instead of using hemp, for profit. "
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anerav | how do movie directors direct fighting scenes? | I just can't wrap my head around this, like do the movie directors just write " *character a punches character b with right hand then immediately followed by right kick* " in the script or what | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/anerav/eli5_how_do_movie_directors_direct_fighting_scenes/ | {
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"Scenes like this are choreographed, just like a music video or a dance. A choreographer works with the director, cinematographer, stunt coordinator, and script writer, and various prop and set masters (or location managers) to work out how the scene will take place. Then the actors and their stunt doubles practice with the choreographer to get the moves right."
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1zdmtu | how does russia have so much political clout when it's gdp is lower than the uk, germany and france. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1zdmtu/eli5_how_does_russia_have_so_much_political_clout/ | {
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"It's still effectively a military superpower, with a massive army, a blue water navy (sort of), and a huge number of strategic nuckear weapons, and is also a permanent veto wielding UN security council member. That guarantees people have to pay attention. ",
"Not a full answer, but I live in the UK and we are already hearing that our energy costs could increase greatly because the UK is partly dependent on oil/gas from Russia. I assume at least some other European countries have the same problem.\n\nThere is also the question of Russia's nuclear arsenal to take into account.\n\n\n",
"It would be easier to answer this question if you can provide a reference to how this political clout is used. Are you possibly referring to the rising situation in Ukraine?",
"The short answer is control over Europe's and China's energy supply, and massive power projection capabilities by merit of having the second most powerful armed forces in the world."
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1nbglx | after i swallow food, how does the body "grab" what it needs? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1nbglx/eli5_after_i_swallow_food_how_does_the_body_grab/ | {
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"This could might help you understand.\n\n_URL_0_",
"It dissolves it. \nBasically, when you chew food it mixes up with the saliva and transforms into a paste. This paste is then mixed up with different acids in the stomach, this breaks down the simpler sugars and fats which are then absorbed by the stomach lining and pass to the blood flow. \n\nThe paste now travels through the small intestine, where the process is repeated (this time more thoroughly) and then through the large intestine, where bacteria feed on the remaining elements the body can't break down on its own, and excrete them into simpler sugars and fats that get absorbed through the walls of the intestine and end in the blood stream. \n\nFinally, what's left is that that can't be broken down any further by the body or its intestinal bacteria, mixed with other waste products like urea and dead white and red cells."
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21i5gu | with all the medical advances, why can't they just develop a ultra strong tooth coating to prevent cavities and tooth wear? | Hi Reddit! Why hasn't anyone developed a ultra strong tooth coating to prevent cavities?
Is it purely a dollars and cents thing? If a something was developed that would drastically cut down on tooth decay clearly Dentists would be loosing money... but is that the only reason something like this does not exist?
ELI5! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/21i5gu/eli5_with_all_the_medical_advances_why_cant_they/ | {
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"You could just get a full set of permanent dentures installed.",
"I think one of the problems would be that the tooth coating would have to be transparent or mimic the natural color of teeth. Also, the layer would have to be exceptionally thin, in order to fit between the teeth. What's more, it would have to be something that is not unhealthy for the body.",
"They do. I had these dental sealants as a kid. For the first few days when I bit down, it felt weird...like my teeth didn't meet, because, duh, there's an extra layer of gunk in there.\n\nIt's a thin plastic film that coats your teeth (typically top of molars) to prevent against decay. They aren't permanent because chewing and saliva break the protective layer down, but I remember getting it reapplied once as a kid. Lasted 3-5 years. Thought was, by the time I was an adult I'd have better dental hygiene and wouldn't need them anymore. That, and I had free health/dental under 18 (thanks Native America!). \n\nHere's the Wiki: _URL_0_\n\nI'm now 30 and still part of the no cavity club.",
"Tooth enamel is already one of the strongest substances produced in nature. It's certainly the strongest, toughest substance in the human body. It's going to be hard to beat.",
"If we could eliminate the bacteria that eat the sugar on our teeth then we would be cavity free. It's not sugar that decays teeth. ",
"Dentist here (of the pediatric variety). This is a good question, and I will try to answer it from a few different angles (this will be a long response, if you want the TL;DR skip to the bottom).\n\nDental decay or caries is one of the most widespread and universal \"diseases\" in the world, and is also one of the most preventable.\n\nFirst of all, there are some really great materials out there that can and do prevent dental decay. First and foremost is toothpaste. A lot of parents ask me what kind of toothbrush/toothpaste to get their kid. My usual response is that the best toothbrush/toothpaste is the one that the kid will actually use. Who cares if it has x/y/z/ features. If it doesn't get used, it's not going to work. \n\nFluoride (while controversial to some), is a very effective topical dental treatment to help reduce decay. Fluoride does several things for your teeth. First, it creates a very tight bond to the hydroxyapatite crystals that make up your teeth (bet you didn't know your teeth were overgrown crystals) in the presence of acid (a big destroyer of tooth enamel), and makes your tooth \"non-stick\" in essence. In theory, fluoroapatite (that is hydroxyapatite that has lost hydrogen molecules, thus creating highly reactive molecules that then bond to fluoride and are no longer highly reactive) is a pretty strong tooth coating, that can actually \"heal\" the tooth by replenishing the broken down enamel molecules (see: _URL_0_). Generally, research has indicated that topical fluoride is effective in preventing cavities, however, systemic ingestion of fluoride (think fluoridated tap water) has no dental benefits after is passes the teeth. Once, again this is a controversial topic, and I won't elaborate more on it right now.\n\nAnother function of fluoride in a dental sense is inhibition of the bacteria that cause cavities. There are 2 main types of bacteria that can cause cavities (strep mutans and lactobacillus acidophilus for those who care), and they don't particularly care for fluoride. It inhibits a key enzyme (see: _URL_2_) in the glycolytic process, which means that bacteria cannot use the sugar you ingest to create enamel destroying acid. Fluoroapatite (discussed above) also is a difficult surface for most bacteria to stick to, so bacteria aren't big fans of that either.\n\nAs a dentist, I like to keep an eye out for new research regarding the materials we use (or could be using in the future) to fix teeth with cavities. It seems like every couple of years there is a new material that has been created in a lab that is going to revolutionize dentistry. The only problem is that somewhere between the initial creation and the actual real-life implementation the new material doesn't exactly meet expectations. \n\nThe basic materials in dentistry are made of polymers and monomers that bond at the molecular level to a tooth. This bonding sequence has been researched for years, and while it is generally understood, there are still many factors that have not been isolated and controlled for. So, while the average dentist has a great variety of restorative materials, they haven't changed much in decades. Gold is actually one of the best materials for fixing teeth, as it expands and contracts due to temperature changes in the mouth (think eating ice cream while drinking hot coffee) similar to the expansion and contraction of a tooth. When these forces are not equalized, tooth fractures can occur (and often do). But gold is really expensive, and not a true option for most (not to mention culturally unacceptable for some in an aesthetic sense). The are a lot of \"white\" filling options, which are generally referred to as composites. These look better, but the life span is measured on a 5-10 year scale, instead of 10-30 like gold fillings. There are yet more white fillings called glass ionomers that are made of microscopid beads of glass mixed in with an array of polymers that chemically react and bind to one another. Many of these glass ionomers are able to bind and release fluoride, and have been shown to be effective in reducing decay that can occur around cavities that have been filled. Unfortunately, glass ionomer materials do not stand up well to the beating that the average tooth goes through, especially in patients who having tooth grinding habits. \n\nAnother newer field of dental materials is combining the best properties of composite materials with the along with the fluoride capturing and releasing properties of glass ionomers. Many studies in pediatric dentistry have established these new \"compomers\" as great restorations for baby teeth, as they bond well to teeth, and inhibit recurrent decay.\n\nOf course, there is the field of prosthetic dentistry that concerns itself with completely covering a badly decayed or fractured tooth with a porcelain, zirconian, gold, white gold, or some other sturdy and durable material. There are even machines that can scan a tooth, and mill an exact replica of that tooth (repaired of course) in a matter of minutes or hours (see: _URL_1_). \n\nSo, there are currently some very high tech and low tech approaches to preventing and treating cavities. In my mind it is a bit odd that in the 21st century the general approach is to drill out the decay and then glue something to it, since it's a technology that essentially has not changed in thousands of years. We've gotten better at it, and there is a whole lot less pain, but it could be much better. I envision a day when a machine does a complete low-radiation scan of a patients mouth, then using that information, it numbs the right nerves, removes the decay on a nanoscale with high pressure water/lasers/mechanical drills, and then replaces the lost tooth material with the latest and greatest material. Like the DaVinci surgical machine, mixed with Japanese robotics, 3D radiological imaging, an IBM Watson IA, and real time mechanical response to patients neurological and physical actions or needs.\n\nHope that helped. \n\nTL;DR There are some materials that do a great job protecting teeth, preventing cavities, and inhibiting bacteria. Each material has it's pros and cons, and continued research is improving on these materials.\n\nEdit: sealants were mentioned by a few other people. Those can be very beneficial. Usually, they are not placed on adults, and most insurance companies will only pay for them on kids under 13 years old. There are various reasons why they are not recommended for adults, and the main reason is that the molar teeth are most vulnerable to decay when they first grow into the mouth (at 6 years and 12 years old). Placing sealants on adults can also cause some TMJ issues due to sudden changes in the way the teeth bite together. Not a fun thing to experience. ",
"White spray on bedliner?",
"Aren't dental sealants on molars pretty common for kids, nowadays?",
"Dentist here. Because f*** you that's why.",
"Dentist here, as well. Preventing cavities is not rocket science. Brush with fluoride toothpaste, twice a day. Floss once a day, preferably before bed. Avoid high frequency of sugar intake. It's not how much sugar you eat, it's how often. Sugar is fine at meal times, but avoid it between mealtimes. If you are effective with oral hygiene and avoid a high frequency of sugar intake, you will not have to worry about cavities. \n\nThis is a profession that if everyone did what we recommended, we would not have jobs. There is no conspiracy. People just aren't effectively cleaning their teeth. They may brush their teeth, but by the looks of things, they're using the wrong end of the tooth brush. I see people come in my office a week after a cleaning with plaque all over their teeth. They ask, \"Why am I getting cavities?\" Possibly because you can't seem to get the right end of the tooth brush in your mouth.... ",
"The top answer is very good, and very decidedly not an ELI5 answer.",
"Tooth decay provides an income source. Same with the medical industry. Why cure a disease when you can make money by managing a disease with medication?",
"This is ELI5 so here you go:\n\nThe mouth is a bacteria hole. You're constantly stuffing bacteria into it in the form of food, your fingers, and anything else that happens to come in contact with your mouth. But this is okay! Your mouth can accommodate (and wants to accommodate) a whole host of bacteria. Some estimates are 400 different bacterial strains can live in your mouth! \n\nYour mouth is also responsible for breaking down the food you eat, so it has the incredibly powerful saliva there all of the time, ready to break down the food you eat before you even begin chewing (this is why you can put candy in your mouth and let it \"melt\").\n\nTeeth have to withstand all of this abuse, as well as the wear that they get from constantly touching other teeth! The mouth is the only place where there's an exposed meeting of hard and soft tissue in your entire body - it is truly a special place - and it's *also* one of the dirtiest! It isn't that dentists are hiding some cure for this - it's that the mouth is actually *amazingly* resilient and miraculous already! \n\nIt's a complex ecosystem of bacteria that requires constant care and attention to maintain.\n\nDentistry is still barbaric - but it's that way because the mouth is so damn tough. Ever held something so hot your fingers could barely handle it, but you throw it into the soft tissues of your mouth without any problem? Those tissues, sensitive though they may be, are very resilient. The mouth heals incredibly well - you can have a tooth ripped out of it and you'll be eating solid food within 30 days. Try having a finger torn off and then using your hand normally after 30 days. And don't forget that they use *diamonds* and high-speed drills to cut teeth because they're so tough.\n\nIt just so happens that there are a couple varieties of bacteria that are such voracious consumers of sugar (and therefore, shitters of tooth-decaying acid) and have had so long to adapt to the human mouth that they are *damn* good at decaying teeth that have lots of fuel (sugar) and time (poor hygiene).\n\nTake care of them! You don't get a do-over. You can make plenty of money in your life, but you can't make more teeth - and all of our replacements for teeth (dentures) really suck.",
"These guys are doing some interesting research. It's apparently a slow process, but I run into articles about them every year or so:\n_URL_0_\n\nBasically, they've engineered a variant of the bacteria prevalent in your mouth that both stops tooth decay (they don't make the destructive acid) and outcompetes the bacteria that does. They've been in FDA trials for a while now.\n\nThere was a popular science article about them a few years ago. I'm sure you can google it.",
"they've already developed a way to prevent cavities completely, by implanting a bacteria in your mouth that kills the bacterium that cause cavities.. it continually gets denied funding, I believe a group found funding to produce it in peru recently. I remember reading about it in readers digest 15 years ago, the article said cavities will be a thing of the past in the next 5-10 years.. I'm going to try to find some articles to link before I post this.\n\nhere's one link about genetically altering bacteria so they can't cause cavities _URL_2_\n\napparently its called a carries vaccine _URL_1_\n\n_URL_0_\n\n\nbut yeah, you're thinking in the wrong way, you think why don't we just build super teeth? our teeth are already ridiculously strong. our teeth should withstand a lifetime of use, but our diets are shit, our toothpastes and tooth brushing techniques wear down enamel, flouride causes fluorosis and is actually bad for teeth and bones. either we evolve to better diets, or genetically engineer bacteria to protect our teeth, not coat our teeth in titanium so we can do and eat whatever the fuck we want and chew glass and rocks.\n\nalso don't listen to that dentist idiot at the top, its in his best interest to install platinum teeth on everyone and bring them in for a polish every 3 months. he's not a doctor he's a failed art student.. or is that architects?",
"I finally signed up on reddit because of this post.\n\n_URL_0_\n\nGenetic engineered mouth bacteria that is stronger than \"normal\" mouth bacteria that has 3 modifications: 1) does not create acid 2) creates a little hydrogen peroxide instead 3) dies unless it gets a certain thing that in early studies was in a mouth wash. (this was required so that you could get rid of it if it turned out to be bad... also then requires you to replenish the bacteria everyday)\n\nI've been using it for a few months; hard to say concrete results, but I've had no bad side effects...\n\nTLDR; genetically modified strains of mouth bacteria to crowd out cavity causing bacteria.\n\nedit: I have nothing to do with the company. Was a technology I liked and seemed to fit the question at hand.",
"Well actually people have been looking into this stuff for a long time Im sure. There is something called Peptide 11-4 they're actually rebuilding the enamel, that thing my dentist told me once its gone its gone. Well im not the brightest guy but as someone who had too many cavities I wish this was around and proven helpful when I was younger. Im sure its just a matter of [clinical trials](_URL_4_) and assessing costs and benefits. Though at this point its on the market in Europe though Im unsure how widespread it is.\n\n[\"The patented Curolox™ technology is based on peptides self-assembling into a matrix triggering a biomimetic mineralisation and repair mechanism.\"](_URL_3_) As well as Curodont Repair. Curodont Protect sounds like something they're trying to develop thats more like what you're asking about. They're really trying to cover all the stages of tooth decay.\n\nHere's a few links I found in about this while in search of never having a toothache again.\n \n[Summary of: Treatment of early caries lesions using biomimetic self-assembling peptides – a clinical safety trial](_URL_0_)\n\nA Pdf of a brochure from Credentis which explains it better than I can.\n[Regenerating Teeth: The New Dimension of Self-Assembling Peptides](_URL_1_) \"During odontogenesis the three-dimensional amelogenin matrix enables crystallisation and ordered calcium phosphate crystal growth. The matrix is subsequently degraded. Scientists from the University of Leeds found a way to mimic the enamel matrix within enamel lesions and thus enabling regeneration via de novo biomineralisation: Self-Assembling Peptides.\"\n\nIf you speak Swiss then this [youtube video](_URL_2_) might explain it better.\n\n",
"three or four years ago a college person in the uk invented a peptide that when painted on a tooth will something something your tooth regrows, or something.\n\nas with all new tech, it took awhile to find funding to bring it to market. some swiss? company is licensing the tech. it's available now, in europe.\n\nnow when are we going to be implanting tooth seedlings into our gums and have them grow into full adult teeth? well that's tricky, china is doing well with all that stuff that's banned in the usa - you know - stem cell therapy.\n\noff topic, has the new pope addressed stem cell therapy yet? i'm rather upset it's still so taboo.",
"People are soft. Attaching something strong to something soft is really, really difficult.",
"Actually they can. I had it done when I was 14 or something. But it doesn't last forever. Wears off after a few years",
"it's losing, not loosing",
"How much could they make off that versus a life long need to go to a dentists.",
"Amorphous calcium phosphate is the future of dentistry. It can be found it some gums and toothpastes already, and you can buy paste if given a prescription. Soon I think it will be main stream. ",
"The amount of conspiracy-mongering here is ... surprising.\n\nIf there's a reliable preventative for tooth decay, the company that could bring it forth would make a mint. The pharma industry is large and sorta evil, but they're not exactly sharing all the money with each other. The incentive for a company to release something so beneficial is huge: the fallout on everyone else is Not Their Problem. It is not conspiracy that keeps things like this under wraps.\n\nIt is far more likely banal reasons like, \"It is unreliable\", \"It has side-effects that make it less than awesome\", \"It is cost-prohibitive to make at scale,\" \"It is undergoing FDA testing,\" or very possibly, \"It doesn't actually work, despite what you've heard.\"\n\nThis goes for most miracles you've heard about: 400-mpg cars being suppressed by Big Oil, perpetual motion machines being suppressed by public utilities, whatever. Things don't make it to market (or, in fact, exist) for a variety of practical reasons that have nothing to do with Evil Men Are Why We Can't Have Nice Things.\n\nAnd brush your teeth. Furrfu, it's called taking care of yourself.",
"I have no idea what the actual reason is, because I'm neither a dentist nor a doctor, but the idea that \"big medicine\" is suppressing an advancement is crazy because creative destruction exists. \n\nIf any one of you guys or girls were to create some this sort of tooth coating, wouldn't you sell it and potentially become a billionaire? Wouldn't you have health insurance companies beating down your door so they would never have to worry about routine dental care again? \n\nNo one is trying to suppress innovation, because that's where the real money is. ",
"I've always been curious why, aside from the potential social implications, people with bad tooth decay problems (or those that just don't take care of them) don't have an option to simply swap out nature for science.\n\nI had a vision of simply removing ALL my teeth, go through a healing period, install whatever the right number of posts into the jaw bone, another healing/settling period and then have something that mostly resembles teeth but is 1 big upper and 1 big lower permanently attached to the posts.\n\nThink of Jaws in The Spy Who Loved Me and Moonraker (James Bond flicks) but with at least a more aesthetic and functional (eating, not attacking) design.\n\nPersonally, I think if something like Titanium is the right material for the job, it would NOT be a bad thing to have a metal mouth. Rather than a mouth full of decay and issues, you just have a 1 stop (3 stop really) fix that lasts a lifetime. Enough people do it and its no longer a social issue anyway. Hell, just look at how many toothless hillbillies are out there. Wouldn't some Titanium chompers be better?",
"It is possible that we are thinking about this the wrong way.\n_URL_0_",
"There's no money in it for dentists if they fix all your problems.",
"Greed.\n\nEverything else is justification. ",
"Because Dentists would get less money, and in this world there is greed everywhere. It's just like curing cancer: there are billions of USD being donated to cancer research foundations each year, but very little progress is actually made even though we are in the peak of medical advances. The reason: corporate greed.",
"Patents. There is a patent for a solid and working toothpaste. Worked on dogs and everything. Was patented and nothing happened which means he was probably paid off / bought out but I don't know. I just know (I think he lives in Florida) some guy took it all the way and we have not seen any products on shelves.\n\n",
"Because that would probably be a one time purchase, and it is more profitable to have people come in all the time to have their teeth checked, rechecked, fixed and refixed",
"Because [an even better idea](_URL_0_) would be to develop specialized stem cells that allow our teeth to regrow multiple times.",
"Wow. CTRL+Phage... nothing.\n\nSupposedly there is a phage bacteria, that will overtake your natural mouth bacteria and instead of breaking sucrose into sugar, this bacteria breaks that sucrose down into alcohol.\n\nIn short, you'd never need to go to the dentist again.\n\nMy guess is that this isn't on this thread because 1. I'm a tin foil hat. or 2. The dental lobby successfully lobbied to prevent FDA approval of this new modern (but industry devastating) dentistry.",
"The crazy theories here have gone wild. As others have said, there are preventive treatments like that already. But they are not permanent and I don't see how they could be unless some radical change in technology allows it. Teeth are subject to a wide array of forces, temperatures and changing chemical and biological conditions. Even if the material does not deteriorate, there is no way to guarantee a permanent attachment to the teeth that keeps them sealed from outer conditions indefinitely and filtration of sediments would eventually be a problem.\n\nThe material for what you suggest could have properties very similar to gold: flexibility, malleability, impervious to chemical decay and not commonly rejected by living tissue. Gold has also been used by humans for millenia and is well understood. Titanium has been suggested but it still is not as easy to work with and cannot be repaired or welded in conditions you would find with your local dentist.\n\nI can imagine a scenario where the cost of covering your teeth with gold is rationalized and at least partially justified (your children could inherit your teeth coatings, for example, either for their own use or for sheer monetary value. Gold can be melted and reused many times, is easy to sell and accepted all over the world. Let's not think for now that people like to steal it). If you take into account all associated costs during a lifetime, probably the choice of precious metal does not make a big difference. But guaranteeing a perfect seal would require constant visits to the dentist for checkups and repair, otherwise teeth would decay more quickly than when not coated.\n\nAn additional consideration is that everything dental is medical science mixed with aesthetics. People worry a lot about their appearance and this coating would have to be not only ultra strong but super pretty or invisible.\n\nTreatment focused on improving oral chemistry and hygiene is much more likely to be affordable, widespread and effective in the long term.",
"For those who care there is NovaMin which rebuilts your enamel. Its the only one so far that does it. I used to for a week and my sensitive teeth are now back to normal. ",
"Because nanotechnology is only just getting started. I don't see why dentists would lose money since people would still need other care and check-ups (and that'd be a bit like saying antibiotics make doctors lose money).\n\nAs an aside, have you been playing Deus Ex lately? ;)"
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1za2tq | how does oculus rift work? | What kind of technology it relies on? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1za2tq/how_does_oculus_rift_work/ | {
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"The basic explanation of it is that it has two screens; one for each eye. It shows a 3D image by playing a slightly different image on each screen; the image for the left eye is slightly to the left of the one for the right eye, so it works just like 3D glasses.\n\nIt also has a myriad of sensors that can detect the way your head is facing so the image you're seeing corresponds to the direction your head is pointing.\n\nIf you have further questions I'd be glad to help."
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es85k5 | i keep having this dry feeling at the back of my throat but it’s not a cold | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/es85k5/eli5_i_keep_having_this_dry_feeling_at_the_back/ | {
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"Not a doctor, but you're probably sleeping with your mouth open. Clear sinuses, electrolytes, and cough drops might help",
"Well, gonna say that that I don't think you should be using this sub for a medical question. \n\nHave you considered gargling salt water? It's possible that you have some phlegm lodged in the general area, perhaps caused or aggravated by postnasal drip. Anyway, salt water is good for breaking up the outer gelatinous layer and, if that area is having some imbalance leading to it being dehydrated, changing the contents of your beverages can affect how hydrating/dehydrating/permeable they are. Seems like you've been trying that with some of the remedies you've mentioned."
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jalw5 | explain finnegans wake to me li5 | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jalw5/explain_finnegans_wake_to_me_li5/ | {
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"For those of you just joining us: Finnegans Wake is a book by James Joyce. James Joyce also wrote a book called Ulysses.\n\n(In case you read my recent post about The Waste Land, we get to talk about aesthetics again, so buckle in.)\n\nThe cool thing about Finnegans Wake is that **even people who talk about books for a living don't really agree about Finnegans Wake**. The book is so long, so crazy, and so weird that everyone has a different opinion of it. Unlike math or science, in literature it's totally okay for two people to have a different opinion of a problem. So when you ask someone to explain Finnegans Wake, you have to keep in mind that **there is really no right answer to your question**. But...here we go.\n\nUlysses, the other book we talked about earlier, takes place over the course of a single day in the life of this one guy. People like to say that it's \"the longest day in literature.\" People like to say that, after he wrote the longest day in Ulysses, Joyce wrote the longest *night* in Finnegans Wake. Joyce said that the book is a lot like a dream, and that he wanted to \"reconstruct the nocturnal life.\" In other words, **Joyce wanted Finnegans Wake to feel like an actual dream**. Because of that, it's very hard to talk about normal book-type things like characters, plot, or setting when you talk about Finnegans Wake. Wikipedia can give you a basic list of what happens in the book, and who it happens to, but that still doesn't get at the heart of what's going on in Finnegans Wake.\n\nThe book is mainly about something called \"aesthetics.\" That's a word that means (very simply) \"pretty stuff.\" Joyce wanted the book to look and sound a certain way, instead of \"mean\" a certain thing. He wanted the readers to enjoy reading the book, and enjoy how it makes them feel. You might notice that the book starts in the middle of a sentence, and it ends in the middle of the same sentence: the book is a big circle!\n\n**TL;DR: Finnegans Wake isn't a novel in the traditional sense of the word. You should read it to enjoy it, not to understand it.**",
"For those of you just joining us: Finnegans Wake is a book by James Joyce. James Joyce also wrote a book called Ulysses.\n\n(In case you read my recent post about The Waste Land, we get to talk about aesthetics again, so buckle in.)\n\nThe cool thing about Finnegans Wake is that **even people who talk about books for a living don't really agree about Finnegans Wake**. The book is so long, so crazy, and so weird that everyone has a different opinion of it. Unlike math or science, in literature it's totally okay for two people to have a different opinion of a problem. So when you ask someone to explain Finnegans Wake, you have to keep in mind that **there is really no right answer to your question**. But...here we go.\n\nUlysses, the other book we talked about earlier, takes place over the course of a single day in the life of this one guy. People like to say that it's \"the longest day in literature.\" People like to say that, after he wrote the longest day in Ulysses, Joyce wrote the longest *night* in Finnegans Wake. Joyce said that the book is a lot like a dream, and that he wanted to \"reconstruct the nocturnal life.\" In other words, **Joyce wanted Finnegans Wake to feel like an actual dream**. Because of that, it's very hard to talk about normal book-type things like characters, plot, or setting when you talk about Finnegans Wake. Wikipedia can give you a basic list of what happens in the book, and who it happens to, but that still doesn't get at the heart of what's going on in Finnegans Wake.\n\nThe book is mainly about something called \"aesthetics.\" That's a word that means (very simply) \"pretty stuff.\" Joyce wanted the book to look and sound a certain way, instead of \"mean\" a certain thing. He wanted the readers to enjoy reading the book, and enjoy how it makes them feel. You might notice that the book starts in the middle of a sentence, and it ends in the middle of the same sentence: the book is a big circle!\n\n**TL;DR: Finnegans Wake isn't a novel in the traditional sense of the word. You should read it to enjoy it, not to understand it.**"
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97e39y | why do you refrigerate eggs you eat, but keep fertilized eggs warm to make them hatch? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/97e39y/eli5_why_do_you_refrigerate_eggs_you_eat_but_keep/ | {
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"Refridgerating eggs preserves them as food.\n\nIncubating eggs gives the embryo the proper temperature it requires to grow."
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3sgwr6 | why aren't the united states and russia allies? what are the disagreements/reasons? | If we can be amicable "friends" with communist regimes like China, etc, why are at odds with Russia? At the risk of sounding completely naive, what stands in the way of mending the relationship? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3sgwr6/eli5_why_arent_the_united_states_and_russia/ | {
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"I think the root of this is in the fact that Russia and the US both have huge nuclear armaments, and the historical flexing of both countries' newfound superpower status after WW2. The countries are therefore rivals to each other in a way that China is not (China doesn't have anywhere near the nuclear weaponry that Russia does, currently). Not to mention that the US and China both have far more mutually beneficial trade benefits than the US and Russia do. \n\nIt's not really about Communism/Capitalism; it's about power. ",
"\"anything you can do, I can do better\" \n\"nuh uh bro!\" \n\"We went to space\" \n\"we landed on the moon!\" \n\"we can blow you up a million times with a million nukes\" \n\"we can blow you up 2 million times with 2 million nukes!\" \n\"In soviet russia, you don't rule communism, communism rules yooouuuu\" \n\"in MURICA, you have the freedom to be in massive debt!\"",
"America and Russia got on...neutrally most of the time. WW1 made them allies, which was nice. But in 1917 Russia overthrew its dictator and had a provisional government. America was actually pretty happy, because it was a pseudo-democracy and it looked like Russia was moving into a more open form of government. Then the Bolshevik's and workers unions fought the provisional government.\n\nThis was bad for America. The communist look of these Bolshevik's seemed counter to American interests and businesses in the area. Most importantly, they wanted to stop the war with Germany (this is during 1917 AKA WW1 remember). That's a big no no. Plus they already liked the provisional government. So America backed the provisional government, sends troops.\n\nWell, the provisional government still lost. The new communist government was, for some reason, unhappy with the fact that american troops had fought a bunch of their troops. They also stopped fighting with Germany, which pissed off the Allies something fierce.\n\nAmerica + Allied Europe VS the Solviets thus are pretty unhappy with each other. Russia keeps trying to start communist parties and overthrows in Europe, which is unwelcome, and the Allies continue trying to overthrow the Russian government, which is unwelcome.\n\nIn america, businesses hold tons of political and public opinion power, and heavily denounce communism as being pretty awful for businesses. Public hates communism, communist groups do some questionable things, ideological Red Scare happens. Communism = evil in America.\n\nEverything putters along, but in 1939 Russia backs German expansion and they sign a peace treaty for WW2. Russia invades several countries. Allies are not thrilled. Eventually Germany attacks Russia. Russia not thrilled. Allies send aid to Russia, but are still extremely mistrustful and unhappy with Russia what with the plundering and invading and flip flopping. Help the bear drive off the pack of wolves rather than be eaten, but kinda fear and hate the bear too.\n\nRussia fights Germany almost single handedly. Gets absolutely demolished in terms of human and economic toll, but beats them back. Allies do not start up a second front for almost 3 full years. Stalin thinks that the allies delayed the second front on purpose to weaken the USSR. Really salty about it.\n\nUSSR and Allies defeat Germany. Stalin is nominated for the Nobel Peace Prize in 1945. Everyone is kind of like \"Holy shit did the Russian's dominate\". Russia refuses to give back territories it gained in WW2, is kind of like \"we earned them\". Allies are unhappy by this, and now that WW2 is over, Russia is the #1 threat. Stalin is super scary, clearly willing to do anything to achieve what he wants, and he seems to want to take over at least most of Europe. Which everyone just finished a big long war to stop someone else from doing.\n\nSo Stalin, with his freedom oppressing, military facist-communist government is extremely hostile to the allies, who they rightly feel have never helped them unless required, have tried to overthrow them, are blocking their interests in Europe, and were indirectly responsible for millions of Russian deaths by not opening up a second front earlier.\n\nAmerica hates Russia because it threatens its allies, it threatens European peace, their leader severely restricts rights and freedoms in their country (America is big on freedom) and communism is heavily mistrusted.\n\nAfter that you get all the iron curtain, Truman deals, etc etc that start the Cold war, but really, The Allies never liked Russia and Russia never liked the Allies. Their alliance in WW2 was more \"Germany is trying to kill both of us\" rather than \"we like each other even a little\".\n\n..\n\n..\n\nToday, America and Russia have about 100 years of that garbage, plus all the wars they've backed opposite sides of. If you ignore the very recent tensions with events in Ukraine, they've had increased trading, polite and friendly space program exchanges, stockpile reductions, joint anti-terrorist exercises, increased business relations, agreement on Iran etc etc. They aren't really enemies or allies, just very mistrustful acquaintances. \n",
"I'm in the Army and I can't figure it out really. It used to be because of communism and stuff. Now, not even kidding, it seems like we hate them and them us just defacto, because we both need a mutual enemy equivalent to each other militarily. It's almost Orwellian. I mean Russia's in Syria taking out ISIS now and my opinion is let them, it means less of our guys have to do the dirty work. But US politicians have a completely different opinion about that I guess for pride? I don't get it.",
"Nowadays, it seems to be primarily motivated by a massive Russian effort to avoid losing Great Power status and entering the USA's sphere of influence. It wants power and influence in the middle east, Asia and Europe, which is also exactly what the United States wants.\n\nHowever, Russia becoming Allies with a former enemy isn't unheard of. Compare to over 100 years ago. Britain and Russia were also enemies, competing for influence in Eastern Europe (Russia wanted to gain more land at the expense of the Ottoman Empire, Britain wanted to prop up the Ottoman Empire) and Asia (Russia was expanding into Persia and getting closer to India, Britain didn't want India under threat). Eventually, these difference were resolved via treaty and they entered an alliance, dividing up their Spheres of Influence, and resolving to take on Germany together in the event of war.\n\nWhat we'd need to have America and Russia become allies is;\n\n* A compromise that gives both sides most of what they want, such as Russia allowing the old Warsaw Pact nations to join NATO in exchange for America giving Russia free reign in Syria and permanently annexing the Crimea.\n\n* A new threat that would be big enough and serious enough justify the two becoming Allies. Barring an unexpected Alien invasion or Demonic incursion, such a threat appearing on Earth would have to be something bizarre and unlikely, such as India and China joining forces (both have huge populations, armed forces and Nuclear weapons). Obviously this is highly unlikely in today's political climate.",
"Clashes of interest. America wants to control certain parts of the world, just as Russia does. Their export industries are also in direct competition, and their defense networks clash.\n\nChina on the other hand is quite content just dealing with stuff that happens within their borders(of course, countries like Taiwan might disagree, as China treats them as parts of china that act rebellious for whatever reason, while Taiwanese themselves seem to think they are a free nation independent of China)\n\nThere are no particular clashes of interests, so both countries can practice their stuff and co-operate, and it's all good and dandy.\n\nIt's a tricky situation for Russia since US has been extending their military rapidly towards Russian borders, using NATO as a cover, and from Russian perspective, having hostile nation military within missile range from your capital city is distressing. US is not going away because they don't really care if Russia is in tight spot or not, and to them having missile bases everywhere threatening everyone is great comfort since that way no one is gonna threaten them.\n\nFor China, the closest US comes to them is South Korea, and handily there is some crazy dictator ruling a tiny land covered in land mines and whatnot acting as a buffer between South Korea and China. How convenient. China for this reason does sorta support North Korea, just enough to keep it existing. They don't want direct border between US and China.\n\nMy credentials are that I've beaten Civ V on Immortal."
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w873f | airplane turbulence and why i shouldn't be terrified of it (my mental health thanks you) | So there's nothing I love more than exploring the globe, except for one thing - I'm terrified of flying. I honestly can't remember the last time I slept on a flight since I usually just focus on not hyperventilating the whole time. Sometimes I get so stressed out I think my brain just shuts down and I conk out for a few minutes, only to snap awake in a white-knuckled, sweaty terror at the first jolt.
**What makes turbulence, how normal is it, and why should I *not* be afraid of it?**
(Bonus question, my ears also got totally stopped up from air pressure today and after 3 hours of yawning, chewing gum, and poking at my temples, I plugged my nose and blew and voila, all better. Huh?)
**Edit: Thanks everyone! This is all very reassuring, and I'm going to read your responses until they're internalized. It's funny, because I know air travel is safe (far safer than cars) but it must be something about feeling out of control and also feeling like if something goes wrong, it'll go *really* wrong, that gets me. But your points all make sense, and yet again, science helps the ignorant and fearful to reach a higher understanding of something that might otherwise be terrifying. Hooray!** | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/w873f/eli5_airplane_turbulence_and_why_i_shouldnt_be/ | {
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"Turbulence is caused by air movements, winds, air coming over mountains, updrafts/downdrafts caused by storms, etc. It's completely, 100% normal. Every flight I've ever been on has experienced some turbulence. You shouldn't be afraid of it because it's completely normal, happens constantly, the pilots are extremely used to it, and it's not going to do anything to the physics keeping the plane in the air.",
"Like you're 5: It's road bumps, but in the air. And what are you scared of? that the wings are gonna break off or something? [That's ridiculous](_URL_0_)",
"The sort of turbulence you're referring to is called *clear air turbulence*, or turbulence that occurs in air that's not visibly part of a storm. It occurs when moving air meets air moving in a different direction. \n\nClear air turbulence is completely normal. It is difficult for radar to detect, which is why a lot of flights run into it. Unless it's unusually crowded airspace, the captain can try to circumvent the turbulence by changing the plane's altitude. If the airspace is crowded, you might just have to bear with it.\n\nAircraft are engineered for *much* more powerful forces than the mere bumps and jolts of turbulence. For an example of totally normal wing flex, see this [video](_URL_0_). If you search \"wing flex test\" on youtube, you can see videos of flex tests they've done where they basically bend the wings in a huge curve without them breaking.\n\nThe bottom line is, turbulence is completely normal, pilots know how to handle it, and aircraft are built more than strong enough to handle it. So next time it happens, just buckle up, put on some music, close your eyes, take some deep breaths.",
"Airplanes fly in the atmosphere. The atmosphere moves around non-uniformly as wind. Wind hits the airplane at odd angles causing turbulence. \n\nBut fortunately, all modern airplanes are either equipped to handle the turbulence they get into, or have radar and sensors that are good enough to avoid the turbulence that will kill you. Finally, aircraft manufacturers have nearly 100 years of experience in constructing robust aircraft that can resist nearly every kind of failure mode ever documented.\n\nCoupled with an incredibly professional flight-staff, robust aircraft engineering, and vigilance of *avoiding dangerous turbulence*, you are far, far safer in your commercial airplane than you are walking down the street, driving your car, or riding your bike. Hell, I don't believe a single US commercial jet has been lost to turbulence in the last 30 years. \n\n\n\nAs far as the bonus question goes: When you plug your nose and blow, you're basically re-pressurizing your head back to the pressure of your atmosphere. Voila. \n",
"A boat doesn't sink just because there are waves. The boat inherently floats because of its design. No amount of choppy seas can make a good boat into a bad one.\n\nA plane is the same. As long as the engines keep working and the plane keeps going forward through the air, it makes no difference how rough the air is. The plane stays up because its engines work. As long as they work, the air can be as rough as it likes. The plane will not crash."
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1hdkwa | how did the first human to learn two languages (assuming s/he did) do it? how could two peoples who cant communicate with language exchange languages? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1hdkwa/eli5_how_did_the_first_human_to_learn_two/ | {
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"The way language evolves and does not immediately occur in a binary state, it's likely the first 'bilingual' person was akin to someone who speaks English like an Aussie but can understand someone from the southern US.\n\nProvide a little more time, space, and economic trade, and now that person can understand and converse with someone who uses a pidgin version of the language.\n\nMore time, space, and evolution, and now it's possible that you have a person who can legitimately speak two separate languages.\n\nThis may be extremely simplified, but it's important to note it's not a chicken-and-egg type issue; you need to factor in the evolutionary component of language over long periods of time.",
"The same way you would pick up a foreign language when travelling, not having a dictionary.\n\nYou'd point at things and learn the local name for it. Then between hand gestures and context, you'd pick up the rest."
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28jfs8 | why do we place such a high value on maintaining human life? | We are all aware that everyone (and every living thing) dies. So why don't we just agree to allow death to run its course? Why do we spend so much money and energy on extending human life when in the end we have really accomplished nothing? Why do so many cultures practice some form of death worship like we do here in America where we remove the internal bits and preserve human remains so people can go and look? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/28jfs8/eli5_why_do_we_place_such_a_high_value_on/ | {
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"That's a complicated philosophical issue with no correct answer, not really something for ELI5.",
"Empathy, you want to live, so you want others to live. You know what it feels like to lose a loved one, and don't want others to experience this.\n\nEvolution, a species that want the rest of the species to live has greater chance to keep existing\n\n"
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2jqsh2 | how did people find lattitude and longitude a long time ago before gps and other systems that we have today? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jqsh2/eli5_how_did_people_find_lattitude_and_longitude/ | {
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"Sailors used tools like sextants, calendars, stars, and compasses to orient themselves.",
"Latitude is pretty easy. You can compare the angle between the sun and the horizon at noon against a record of what it should be for a given latitude and from that calculate where you are.\n\nLongitude is harder, and was actually one of the biggest challenges in navigation. This is because you need a clock which can keep very precise time for months while on a pitching ship. Once you have such a clock, you set it for your home port, and then compare the shown time against when local noon happens, and from that calculate your longitude.\n\nBefore they developed such clocks, many ships would simply sail north or south to their destination latitude, and then sail due east/west until they ran into their destination."
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1kalod | when you lay on your arm and it falls asleep because you cut off the circulation, why does the blood not get backed up in your arteries/veins? | I'd imagine it like piping where the pressure would keep building as more and more pumps occur? But I've woken up to a completely numb arm after sleeping on it and everythings fine, is the circulation not completely cyclical? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1kalod/eli5_when_you_lay_on_your_arm_and_it_falls_asleep/ | {
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"Common misconception, but it goes numb because you've put pressure on a nerve or nerves so it stops working properly, not because of lack of circulation. \n\nThis is sometimes called \"pinched nerve\".\nAnd when nerve signals get mangled our brain can interpret them as pins and needles, pain etc.\n\nFrom the [National Institute of Neurological Disorders and Stroke ](_URL_0_):\n\n > What is Pinched Nerve?\n\n\n > The term \"pinched nerve\" is a colloquial term and not a true medical term. It is used to describe one type of damage or injury to a nerve or set of nerves. The injury may result from compression, constriction, or stretching. Symptoms include numbness, \"pins and needles\" or burning sensations, and pain radiating outward from the injured area. One of the most common examples of a single compressed nerve is the feeling of having a foot or hand \"fall asleep.\""
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97i8yg | how do people who crack games get said games to crack ? | How do people who crack games get the games before they crack them? How do they get the source files on their pcs so they can crack them ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/97i8yg/eli5_how_do_people_who_crack_games_get_said_games/ | {
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"The software is being cracked by reverse engineering already compiled product(game executable) and enabling the person to reach to some parts of the product which would enable him to change vital binary codings and override the protection.\nNot the simplest explanation, but i hope u get the idea.",
"Often times they get the executables(binaries) directly from the CD/DVD or digital downloads. Then they will use a utility, like hexrays to attempt to decompile it, or reverse assemble. At that point they are looking for a way bypass the activation method or software security.",
"Indeed they don't have access to the source files. They have to work with the released binary EXE file as it is. To help crack they typically use a debugger application to step through the raw CPU instructions while the program is running, then editing the file once they find the exact location of DRM check.\n\nIt could end up as simple as changing just a few bytes which correspond to a single jump instruction. Of course, things can get a lot more complicated with different types of DRM.",
"Back in the old days, we buy the game, crack open the cd casing and burn the disc into an ISO image for IRC XDCC file sharing. Today, we hex the exe files to figure out what the game does on launch and what to disable in order to bypass the \"disc/file detection\" portion. That is why you always get a modified exe file as the crack as said crack has the detection disabled, thus allowing for no-cd gameplay as well.\n\nThe funny thing is back in the old days...even when we own the real game physically, we still download a no-cd crack for convenience lol. Ah the good old days. Mech Commander, anyone?",
"They often have sponsors or have the games gifted to them to crack them.\n\nThey dont have the source code, but they decompile the installed files and pick through the memory of the running application to look for and disable the protection, then they write patchers to apply the changes to the executable.",
"Back in the day, and probably still happens, the gold disk would go to production in advance of the release. Workers at the production facility would steal a disk and post the binary files. ",
"Same way that people who just play games get them: buying them on a disc, or downloading them from the internet.",
"They don't have source files.. Well, if you're talented enough, any EXE is a source file because it has all the code in it. Most use decompilers that generate possible source code based on patterns in the EXE.\n\nAs for getting the game files.. well ugh just buy them then distribute them (still copy protected) I guess.",
"ELI3: \n\n\nYou get the program walking (like running, but slower, step by step) until you see it check if it's original. You follow him through all those steps until the check steps are over. You then make a bridge from right before the check to right after the check. The program can now run straight and never hit the check. \n\n\nSometimes programs are designed to mislead you, walk in circles, do many checks in different parts, etc. That is what makes it difficult and challenging.\n\n---\n\nEdit: \n\nJust to give a quick and simple perspective of how slow the program walk: If you have a somewhat common processor (running at let's say 2.5 GHz) that means that when running, a program is taking approx. 2,500,000,000 steps a second.\n\nEdit2: oopsie, missed 3 zeros.",
"There's actually an awesome history of cracking groups. We won't go into it, but one of the most valued positions within a cracker group was often the person who could get access to games. In the early 2000s cracking groups would have people lift games from deliveries to their gamestop store. In fact, if you pirate on console you'll find those games are often out before the game itself. That's usually why. Someone works at gamestop and literally took a disc. \n\nFor PC it gets more complicated. Whereas consoles tend to try and lock their console and leave their games unprotected, for PCs its often the other way around. And then you have Steam and online and blah blah. \n\nWhat PC games, especially on steam will do is either a) not ship the CD physically. The gamestop employee can just get the download code - not useful and very easy to trace that its been stolen. The game itself is often downloadable. or b) when they do have the files on the disc or predownloaded, they often are missing a key to unlock the files. \n\nThis means day 0 on PC is pretty rare now. Not unheard of, FFXV was cracked before release because the demo exe had files they used, but for everything else it is often 3 months. So how do they get the games to crack em? Honestly? Probably just buy them and download them from steam. \n\nThen its something called reverse engineering. It used to be simple, there was a part of the exe file for a game that would check the cd was in the drive. All they'd need to do to crack it was remove the cd check. These were called no cd cracks! These are still invaluable for a lot of older games. \n\nNow though, you have something called Denuvo, and rather than simply putting in one line of code that can then get taken out, they add thousands if not millions of lines of code, woven into the code for the game. That makes untying all that and reverse engineering time consuming. Lots of people have hailed it as the end of piracy, and it has slowed it down. But it hasn't stopped. \n\nThe problem with denuvo though is that its a lot of security through obfuscation - that is, it works as long as you hide how it works. This is great - until someone finds out how it works. Then literally all of your security becomes instantly useless. This has happened to Denuvo a few times. Each time it happens, its harder the next time to make your stuff secure. Because the crackers are onto you now.\n\ntl;dr - they used to have someone steal them, either from gamestop, or sometimes by someone within the developers. Less possible for this to happen on PC, but on console they still do it this way. Another way is the use of demo exes. Developers release a demo, and that demos exe contains the code that can be used to convince the program its legal. ",
"Easy... By buying them :p\n\nIt's like with scanlation... The scans don't just magic them self... Someone had to spend money on them...\n\n**OR**... They were leaked by a third party(review copy)/inside job/etc...",
"Sometimes someone who owns the game uploads a \"FULLUNLOCKED\" version which does not have any crack installed and is just the game files so then the cracker can download that and crack it ",
"I've cracked a program before, but the process is similar. Granted this is for super simple most likely older games. What you do is download a program like ollydbg and then watch a bunch of Youtube videos. The short of it is that you search the binary for any strings and then it gives you a list. You look for one that talks about the license not being valid. Then you open up where that is in the binary and look above it for a jump (jmp) and then try changing it to something else and see if that lets you skip the license check. If not, try another jump. Keep on going until you get the result you're looking for.",
"A man is reading a list of instructions on what to do. Let's say this particular list of instructions tells him how to let you into a theme park. As he goes through the list of instructions he asks you for your ticket, but you don't have one so you can't get in today. After his shift you know where he keeps his instruction list, but it's in German! And you don't speak German. But you take a copy anyway. Tomorrow you try to get in, and you follow the man along as he's reading the instructions, and when he gets to instruction 52, he asks you for a ticket, and then turns you away for not having one. After his shift, you go to where he keeps his instructions and cross out line 52. The next day you get into the theme park because he didn't check for your ticket.",
"They typically have a source where the DVDs are pressed or where the first copies are couriered.\nThese people sometimes get paid money for early copies or access to group servers with free software as a reward for their services. \n\nNext the cracker had to figure out what type of copy protection is being used. \nIf the game asks for a serial number it's fairly simple. \nYou'll need a so called debugger which is a program that loads the file and executes line by line so that you can find the exact spot where the game asks for the serial. In that location will be a jump point to calculate if the serial you entered is valid. \nThis part is an equation somewhere in the program like a + b = c just more complex. \n\nOnce that equation is found you can make a key generator. \nThis is a very simplified explanation. \n\nIf the program needs a license like a physical file to be present it can be trickier. \nYou can sometimes make the game think it's there by removing the parts that check for the file. \nOther times it's as simple as setting something from \"no\" to \"yes\".\nThen there's the situation where entire parts have to patched with additional code. \n\nThere is no one size fits all solution, but the main steps remain:\n\nIdentify protection\nLocate copy protection\nRemove/fix protection. \n\nThere's debuggers that show the code as the program is executed, which tell you where to go in. \nHex and other editors to modify the file. They use programs to freeze the game/software in order to locate jump points. And other programs to hide the cracking software being used as some games/software checks to see if certain prisms are running and just shuts down if it detects them. ",
"Sometimes, they get leaked versions of the game from someone on the dev/testing team... maybe not directly, but indirectly they get access to early builds, or even retail ready versions pre DRM, or just early access to the normal version we all get.\n\nAlso it should be noted that there are only a handful of DRM \"Types\", breaking it once will often make it very easy to break it again, and if you've already broken most of them out there, and new games release with the same old protections on them...sorry this isn't eli5 enouph... \n\nIf a thief breaks into a vault, once inside he can clearly see all the weak points, and some vualts won't fix how he got in the first time, so he can just keep getting in until they come up with something new, at which point he either uses one of the other weak points, or starts over getting past the new thing.",
"Sometimes releases are \"zero-day\", meaning they got a copy from the factory where it's being pressed or something like that. Other times, someone rips the disc from a retail copy after launch and uploads it (without cracking it).\n\nThere are networks that specialize in distributing those filezz, then they make their way to the hands of someone who puts the game on a disassembler/debugger and starts trying to figure out the copy protection mechanism.",
"There almost HAS to be a patient zero nowadays for PC cracking. Most of the time it's someone who just legitimately buys the game and then distributes the game files. Unless there is an insider willing to dish out free copies to someone, which is also a method I've heard of. But that's risky. Sometimes it's by mistake, or through malicious efforts, such as compromising a studio and stealing the files. That's much more rare, but not unheard of.",
"when we ‘cracked’ Apple //e games … back in the day … lol\n\nI would use a HEX search tool to search the disk near the 1st Track Sector List for the string 4c 00 c6 which is a jump to the ‘reboot’ code in the ROM of the disk controller which devlopers would jump to if a ‘copy’ was detected.\n\n",
"The games are in EXE files, which are cryptic code that only a computer understands. The game makers convert code thats understandable to humans to cryptic code. The cracker's talent lies in deciphering this cryptic code and beat the checks that the game makers have put in. The crack program will overwrite some instructions in the EXE file.\n\nIts like a lock maker makes the lock and key and only those with the key shall pass. But a thief can use some tricks to beat the lock.",
"Back in the late 80's and into the 90's it was far easier.\n\nPeople who worked at software stores in the mall would simply take em home at night, make a copy (using just about any utility that could make an image of the disk) and then bring it back in the morning and reshrink wrap it. The reason was that there was no internet to validate things and serial numbers could easily be reused over and over again.\n\nIn the 80's with Commodore games - it was even better - you'd just buy the game, use some software to copy and defeat the copy protection and then return the game. Since they didn't think you could copy games then and returning a game would just get re-shrunk wrapped - an opened game wasn't a problem like it is today.\n\nBut of course I heard this all thru second hand conversations... :)",
"Not really about cracking games that much, but my favorite anti piracy method was Bohemia interactive's approach. They would release cracked versions of their games, but it was coded to make it so cracked copies would slowly degrade getting more and more wonky. So you get an hour or two of good gameplay, nut then it just gets weird. It's a MilSim and they'd change certain parameters like your accuracy. So close up you'd have no problem shooting people, but at 50+M you'd have a snowballs chance in hell at hitting anything. So people with pirated copies actually went to their fourms and talked shit about the game. Then the devs would even occasionally call them out.\n\nOf course people eventually did defeat the code, but it took a long time and I'm sure lots bought it out of frustration if the first couple hours of gameplay hooked them.\n",
"Post probably won’t get read but from personal experience. Back in the AOL/CompuServe days, over 20+ years ago, groups were cracking and releasing software. A lot of the software came from the software developers or beta testers. Having a Microsoft beta tester access was a golden ticket to any online group, you would download the beta/final versions from a FTP server using your unique login and password. Other software had beta tester, ie: Starcraft and a lot of software were released that way.\n\n\n & nbsp;\n\n\nYou then have the workers that work at the dvd/cd manufacturing warehouses. They provide a lot of the RTM/Golden Copy software releases or movie rips. Screeners/academy award/press/etc would get copies to watch before the official release and rip them. I still remember titanic was send to academy award reviewers with vhs and a classmate was using copies to score points with girls.\n\n\n & nbsp;\n\n\nSame with music, inside people who manufacture the CDs. Some of this involves triads/yakusa/etc once you go down the Asian manufactures.\n\n\n & nbsp;\n\n\nProduction companies started to label each movies with special numbers to identify who leaked it, require special serial to unlock the software, movie screener played in color and randomly switch to black and white, cd required to run the software was adopted, dvd decryption code was adopted, serial numbers adopted, etc.\n\n\n & nbsp;\n\n\nNow cracking involved a lot of math to take multiple serial numbers and finding a pattern to create a serial generator. I still remember the calling for all the windows keys to help the group come up with a pattern and the key gen was created. Then online activation came and that was fun to crack. Hexing a file to look for certain codes like how the DVD movies was cracked because the software developer didn’t encrypted encrypt the decyper key. It gets technical.\n\n\n & nbsp;\n",
"They decipher ‘machine code’ to figure out how the human tried to hide code that checks if the game was purchased. At the end of the day the machine code explains to the computer to (as well as how to) confirm it was a valid purchase.\n\nThe human wants to explain this check simply to the computer while making it look complex to humans.\n\nThe cracker reverses this process."
]
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425em3 | what physically causes performance loss on electronics when heat is applied? | What physically happens to cpu's and gpu's that causes it to lose performance? How does the electronic parts overheating translate to dropped frames or sluggish response? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/425em3/eli5_what_physically_causes_performance_loss_on/ | {
"a_id": [
"cz7ozgn"
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"score": [
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"text": [
"When metal is heated it expands pushing the electrons further apart. Conversely when it's colder it shrinks and puts them closer together. As electricity is merely the flow of electrons, they flow more efficiently closer together."
]
} | [] | [] | [
[]
] | |
boeobr | when gas becomes plasma, what is happening to the molecules? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/boeobr/eli5_when_gas_becomes_plasma_what_is_happening_to/ | {
"a_id": [
"enh35io"
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"score": [
2
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"text": [
"The electrons become so energetic that they strip themselves away from the nuclei, essentially breaking first molecules and then atoms apart and becoming a soup of atomic nuclei and loose electrons."
]
} | [] | [] | [
[]
] | ||
5id4ou | what part of cancer makes it so hard to treat/cure? | I've heard things like "its a disease of the cell and therefore is hard to treat" what about it being a disease of the cell that makes it so hard to treat? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5id4ou/eli5_what_part_of_cancer_makes_it_so_hard_to/ | {
"a_id": [
"db781m6",
"db78eef"
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"text": [
"The disease is you. It is your own cells mutating. That means there isn't a foreign contaminant (like a virus, bacteria or parasite). This means it is not only really hard for your immune system to notice it (as your immune system normally ignores your own cells except in the case of immune disorders) but it also makes it hard to find a drug that will treat it that only affects the cancer cells. \n\nIn addition to that, cancer is not a single disease actually. It's more like a whole different collection of diseases that work roughly the same. So there is never going to be just one cure. Each cancer will most likely need its own cure (plus alternatives for the people who don't respond to that cure). Already we have some cancers we can treat fairly well, and some cancers that are just a complete wash. ",
"A lot of diseases are caused by external factors like a virus/bacteria or a parasite. In those cases treatment is a matter of eliminating whatever caused it. You can antibiotics to kill off something that's making you sick, and you can use vaccines to build resistance to something that might affect you in the future.\n\nWith cancer, however, the problem is actually a defect in our own body. There's no external force to eliminate, no invasive virus to vaccinate against. Yes, external factors (like smoking) can accelerate the process, but ultimately it's unavoidable, no matter how healthy your lifestyle, because of how our cells reproduce.\n\nThe other problem is that \"cancer\" is a wide net that includes a lot of different diseases. Many do have treatments, and some have cures, but curing them all is like finding a cure for the common cold. There are just too many variants to deal with."
]
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[],
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6gcmga | the frank dodd act. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6gcmga/eli5_the_frank_dodd_act/ | {
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"Not to shame you because I don't know much about it either, but it's Dodd-Frank because it was named after the co-sponsors of the bill. ",
"minor, but it's Dodd-Frank.\n\nIt's a big bill, so i'm only touching on the biggest highlights:\n\n\n\n 1)\ninstituted higher capital requirements for \"too big to fail\", including so called shadow banks like GE's finance arm. (the idea being we can't *not* bail them out, they're too big and it'd wreck the rest of the economy. so we can make them much much less likely to fail. if a bank doesn't like it, they can split into smaller pieces)\n\n2)\ncreated the \"Volcker rule\" to limit proprietary trading(trading with their own money), which can be risky\n\n3)\ncreated a \"wind down\" procedure for big banks, so in the case of a crisis they won't threaten the rest of the economy.\n\naside)\nthe of the above(1,3) are audited by the fed to insure compliance\n\n4)\n created the CFPB- the SEC's sister orgnanization(the SEC only protects investors, not consumers), whose goal is to protect consumers (they were behind the big Wells Fargo fake account bust), mainly by consolidating regulations that were already on the books in various agencies, but not a priority\n\n5)\nrequired derivatives to be traded through a clearing house\n\n6)\nCreated the fiduciary standard for brokers who work with retirement funds. (Fiduciary standard means they have to put your best interests first, instead of the current where they just have to find something \"suitable\")\n\n\n"
]
} | [] | [] | [
[],
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] | ||
9bw8lu | do animals such as bison or rams experience cte like humans do from repeated head trauma? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9bw8lu/eli5_do_animals_such_as_bison_or_rams_experience/ | {
"a_id": [
"e569bfz"
],
"score": [
3
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"text": [
"If I remember right some animals actually have automated systems that can increase the blood volume around there brain. so that there is more present when they butt heads. It acts like an additional protection. There was actually a studying being done to see if there was a way to replicate it in humans for sports like football. I not sure how valid the science is but it's called the q collar I think."
]
} | [] | [] | [
[]
] |
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