Subset (10)

eli5 · 25k rows

Split (1)

train · 25k rows

query stringlengths 20 300	positive listlengths 1 1	negative listlengths 1 1
Why aren't we moving at the speed of light?	[ "How long an explanation do you want? The first thing to note is that massless particles do not have a rest frame. By definition massless particles move at c in any inertial frame, so there is a clear contradiction if you try to construct one with a massless particle at rest. There is also a geometric explanation w...	[ "To say what would happen, you need a reliable theory. But there are no reliable theories in which ftl travel is possible. There are plenty of crazy theories with ftl travel, so I guess you could pick one and use that, but it would be no less scientific to save yourself the effort and just make it up :)" ]
if it's electoral votes--not popular--that elect the president of the USA, then what would have to happen for a third-party president to win?	[ "The same thing that a major party candidate has to do -- win a majority of the electoral votes. Since the voters in each state choose who the electors are, the third party candidate would have to have a lot of support in almost every state." ]	[ "EMP stands for electro-magnetic pulse, in this case [Nuclear EMP](_URL_1_ ). When the device detonates, the gamma radiation emitted runs into the gas in the atmosphere. It knocks off the electrons, in a phenomenon called the [Compton Effect](_URL_0_). All the electrons in the Compton current are moving very fast >...
How do you record your TV screen when playing PlayStation while at the same time filming yourself playing games like the YouTube vloggers do?	[ "To capture the TV screen, you would use what's called a capture card, such as [this one](_URL_0_). Your console output goes in one end of the card, and the other end of the card goes out to the TV. A third connection runs to a computer where it can be recorded by recording software. This connection contains all th...	[ "I recommend /r/gamedev But it(at least indie, or small scale simplified): -the idea is made, and a rough draft is created if an engine is established(creating your own engine is very costly both $$$ and time) (Currently Unity and Unreal Engine 4 are the big ones) -Basic assets are made(everything you see in a game...
If Helium is lighter than other gases and keep rising up in the air, how is it caputred and filled up in cylinders?	[ "There are pockets of it underground. When these are discovered, it's pumped out and put into containers. It's typically found mixed with natural gas, and there are ways of filtering it out. Helium that escapes into the atmosphere is gone for good. Back in the day when it was thought that lighter-than-air craft wou...	[ "Let me just chime in here with the actual practical answer to your question. The way that you stockpile gas is by purchasing gas futures. This is a contract whereby someone agrees \"I will give you X amount of gas in the future at Y price.\" Y price usually is a function of today's price + market expectations + a ...
Suppose I held out my hands 2 metres apart, palms facing inwards. Then every second I moved them closer to eachother exactly half the distance than what they previously were for an undetermined amount if time. Would they ever clap?	[ "This question was removed because I believe there is an error how you've phrased it. If your hands are two meters apart and you move them each half that distance, you're moving each hand one meter and they'll clap. If you meant the you're moving each hand half the distance to the midpoint, you're talking about [Z...	[ "If you know the full Hamiltonian for your system and the initial state, you in principle know how the system will evolve for all time. The time evolution is governed by the [time-dependent Schrodinger equation](_URL_0_). However you don't necessarily know what the results of measurements will be. For example, if y...
Why do most websites default to creating an account instead of a return user login?	[ "They would rather a site newbie not have to search to find the \"sign up\" page but rather a returning, and more experienced site user navigate to find the login page." ]	[ "Imma answer your question, but first let me tell you about this time I watered the lawn on a warm july afternoon, there were clouds in the sky and childrens laughter.... ok seriously, who knows, maybe they just like to hear themselves type, or create an emotional connection to the recipe, perhaps they are just kil...
Why do female dogs hump objects like their male counterparts?	[ "Dogs actually mount and hump each other as a sign of dominance. The one on top is in charge. Both figuratively and literally. This action is an act of dominance in both male and female dogs. It has nothing to do with sex or being turned on." ]	[ "They don't have to wait for the animals to do anything. Artificial insemination has been going on for a long, long time. That said, many animals will breed with whomever is available. Scientists probably have a harder time preventing this than getting it to happen." ]
How valid is the theory that the European colonization of the New World caused reforestation, leading to the Little Ice Age?	[ "I've read a lot about historic climate shifts and I don't think I've come across this theory. Most accounts of the Little Ice Age place its start around the 14th century. In the 1310s there were a sequence of years with catastrophic rains during the growing season, leading to famine, and of course beginning in 134...	[ "From the exact same XKCD article that you linked: > (Climates can be hard to predict—for example, in our world, Somalia and French Guiana both sit on the equator, at the eastern coast of a continent, and seem like they should both receive a tropical sea breeze. But coastal French Guiana is dense rain forest while...
If radiation exposure causes cancer, why do they use it to treat cancer patients? Won't it just guarantee they will develop more cancer in the future?	[ "Radiation exposure damages cells, including their DNA. Cells with damaged DNA can become cancerous because the damage can cause them to replicate uncontrollably, which is what a cancer is. But enough radiation exposure will kill a cell outright, including those which are already cancerous. So doctors administer ra...	[ "We have made functional fusion reactors, the Joint European Torus actually works quite well, and the ITER should be significantly better but isn't completed yet. So far fusion isn't commercially successful because it takes more power to create the fusion than it gets back out and cannot run continuously but it d...
What was the 1st division of Germany about?	[ "\"1st Division of Germany\" could mean a lot of things. Maybe this answers your question. Rather than let the Germans control their own fate, after World War II, the allies occupied Germany, and split it into four pieces, each administrated by one of the allied powers (France, England, the USSR, and the US). In ad...	[ "Not sure if you're an American, but have you contacted the [National World War I Museum](_URL_0_) in Kansas City, Missouri? Their collections include manuals and technical specifications from the war. Alternatively, if you're from Britain the Imperial War Museum is where I would start." ]
Is Wi-Fi emitted equally in all directions, like a sphere and if so why?	[ "Depends on the antenna, some antennas try to send the signal in all directions, some try to put it in a very small beam, most try for omnidirectional or close to it. The way the antenna transmits the signal is called it's [beam/radiation pattern](_URL_0_). Google that term for lots of pretty pictures of what real ...	[ "There's a satellite up in space and a dish on the roof of your house. When you try to go to a website, your computer sends a request through the dish up to the satellite. The satellite sends that request down to it's company's tech center and they fetch the website over the internet. Then that data gets sent up to...
Will Fish evolve to not bite hooks?	[ "Obviously the fish doesn't think it is a hook (/bait) but an insect, small fish or whatever (depending on the species). For fish to evolve to avoid biting hooks they must * be able to distinguish between the bait and a real/normal source of food and/or * have an alternative food source (avoiding the bait-like-loo...	[ "Your asking essentially the chicken or the egg. Example, Did you stomach evolove first and create your brain and extremites to feed it. Or did your brain grow your stomach to power it. Har to say, as without something to feed the stomach, we would have no stomch. Without the brain to run everything, we wouldn't ha...
Why do people with bed sheets over their heads get recognized as ghosts?	[ "I know this one sort of! Back in yon olden days, caskets were a luxury item that could only be afforded by the rich. So, rather than just dump their dead in a hole (ironically: because ghosts), the poor would wrap them in sheets and blankets. When it was scaring time and people wanted others to think they were gho...	[ "[Striped shirts](_URL_0_) tend to cause problems with video recording and, if the pattern is fine enough, photos. It is due to the creation of a [moire](_URL_1_) pattern where 2 sets of parallel lines that are not quite parallel (the lines on the shirt and the pixels on the sensor) create a illusion of density wav...
Did the discovery of the Higgs particle actually prove or disprove either Super-symmetry or the Multiverse theories?	[ "Nope. It confirmed a prediction of the [Standard Model of Particle Physics](_URL_0_). The Standard Model doesn't say anything about supersymmetry (often abbreviated to SuSy) or the multiverse. SuSy is a hypothetical extension to the Standard Model. It's a pretty extension, but to date there is absolutely no experi...	[ "Because in theory it allows you to compute both values at the same time. So, lets say I'm trying to hack an encryption. The encryption uses 10 bit key. So in order to break it, I have to try every possible input for that key, and decrypt with each one: 0000000000 0000000001 0000000010 0000000011 ... 111111111...
Why are planets round?	[ "The way gravity works is that it pulls objects towards the \"center of mass.\" In large objects, like planets, this results in a more-or-less even distribution of material around the center, which leads to a spherical shape." ]	[ "Strength. The rims etc. allow thin plastic to be stronger than it would if it didn't have any shape to it." ]
Does a star oscillate between ignition and non-ignition at the beginning?	[ "Follow-up question: has anyone ever witnessed a new star start shining?" ]	[ "A few more interesting facts: 1) The earliest morse code transmitters used to establish the first intercontinental radio links were nothing more than rotating disc dragging a series of conducting plates across a metallic lead and generating a shower of sparks (google SPARK GAP TRANSMITTER). As discussed elsewhere ...
How gas masks work and their effectiveness.	[ "The round thing on the front is a filter. If you have a Brita water filter at home, you know how a filter works; stuff comes in, bad stuff stays in the filter, and purified stuff goes through. The gas mask does the same thing, except to air, and filters more compounds than a Brita does." ]	[ "Saw this on TV a while back, and it did a decent job of explaining it. It almost seems \"staged\", but I think it's pretty accurate. Also, ignore the racist comment in the video... _URL_0_" ]
Why does turning electronic items off and on usually fix the problem?	[ "Look at it like a chess board: After 100+ moves, it's hard to set every step back until you're in the start position. It's easier to remove all the pieces from the board and start all over. ^This ^was ^explained ^before" ]	[ "When things get hot they expand (get bigger). Inside your engine are a lot of metal things that work best with a very specific amount of space between them, measured in thousandths of an inch. When your engine is cold the metal bits are smaller and those exact spaces aren't the size they are supposed to be. Get th...
How much work does laundry detergent really do?	[ "Ok, I love me some Cecil Adams. The guy has a surprising accuracy rate, and it's great. From time to time though, he really misrepresents the data given. In this case, the laundry detergent report from CR he cites is exclusively about stain removal, not cleaning the clothes. There are a lot of problems with clot...	[ "How Stuff Works covered this in one of their podcasts, it was pretty interesting. Here's the link if you're still interested. _URL_0_" ]
Is it true that higher quality alcohol will give you less of a hangover?	[ "There have been some studies (disputed in comments below) that show that congeners, the impurities in alcohol, have a positive correlation with hangovers. Here are two such studies: _URL_2_ _URL_0_ (thanks /u/icedoverfire) I believe there are also studies that show that less expensive liquors generally have more c...	[ "You are right. It is mostly just the advertising aimed at making you buy it. So go for generics. Do not pay extra for the advertising. Ibuprofen is the same drug whatever the brand name." ]
How do shows on Disney/Nickelodeon get low ratings and views but stay on the air for years but shows on CBS/ABC that get better ratings and views get cancelled after 1 season?	[ "TV shows on CBS and ABC cost way more to produce than the shows in Disney, so they need much higher ratings to justify their continued existence." ]	[ "The idea of Net Neutrality is that all internet traffic has equal access to bandwidth/speeds. Doing away with it would be akin to allowing for highway speed limit signs that read \"Speed Limit: 65, BMW Owners Speed Limit: 85\" if BMW decided to pay for such access as a selling point. Or conversely, it'd be like a ...
Why are we not using nuclear propulsion in commercial ships?	[ "It's way, way, WAY, too expensive. The power plant alone would probably be more expensive than the entire lifetime cost of an average bulk carrier. Not to mention the insane mess of regulation that is involved with running a nuclear reactor. Basically, big ships run on bunker fuel, and bunker fuel is ludicrously...	[ "A couple reasons. In the United States, the burden of proof is on the prosecutor to show that the defendant committed the crime. This \"presumption of innocence\" makes preparing a case hard work, because to win, the prosecutor has to convince 12 regular people that, with absolutely no doubt, the defendant commit...
The Habsburgs had an elaborate burial tradition: their hearts, intestines, and bodies were all buried in separate locations. When and how did this originate?	[ "Follow-up question: was this only done by the habsburgs, or were there other important dynasties that did this as well (eg Hohenzollern, Capet+cadet branches, English monarchs, etc)?" ]	[ "Do you want to know how a new \"tissue\" evolves or a new body part? The evolution of body parts was likely due to a gene duplication of hox genes. Hox genes are developmental genes that are located anteriorly to posteriorly (in order) and allow for segmentation during development. Here is how they'd be laid out o...
Why are our current methods of producing meat considered "unsustainable" by many environmentalists?	[ "Meat animals consume so much grain, if everyone consumed meat at the rate Americans do now, the world would not have enough grain." ]	[ "Before I answer, may I ask who the speaker is for this particular lecture? Or if you have a link for me to listen to? I would like to know where they are coming from in their argument." ]
What happens to submarines during tsunamis?	[ "I was deployed on a sub during a tsunami. It was a complete non-event. We couldn’t tell it was even happening." ]	[ "I might be able to help with this if you can clarify your question a bit. Specifically: in which navy or navies? what type of ship or mission did you have in mind?" ]
What is the largest known thing in the universe, and what is the largest singular object in the universe?	[ "Rather than asking you what constitutes a \"thing\" or an \"object\", I refer you to this site, see what you think. _URL_0_" ]	[ "It's all about relativity. If the Hulk ran for a quarter mile, he'd only appear to be moving a few dozen widths of his body size. If a dragonfly then traveled the same distance and speed, it'd appear to be moving thousands of widths of its body size. So they cover the same distance but relative to their body size ...
Plato's Cave Allegory	[ "Plato is arguing that what most people perceive is just a \"shadow\" of the real world that underlies our perception. He is arguing that if we really want to understand the universe, it's not enough to just look at the shadows, we have to use reason, philosophy, etc . . . to escape the gave and observe that actual...	[ "You know how people thought there's some angry god that throws lightning bolts when you do or don't do something? Well people are afraid of things they don't understand." ]
Is it possible to dehydrate an egg white without it denaturing?	[ "Sure, that's the process of [lyophilization](_URL_0_). More or less, you freeze a sample, then evaporate off the water under vacuum. In some cases the freezing can occur during the vacuum process, as evaporation cools your sample. As /u/rupert1920 points out, not all proteins survive this process intact, the dehyd...	[ "A few videos on youtube by people who make that kind of stuff: _URL_0_ _URL_1_ You need to start with a seed crystal which you dip in the saturated solution and then as the water evaporates the salt precipitates on the seed crystal. You may be increasing the speed of the evaporation by heating and that may be caus...
Why are people allowed to do unproductive things at work but not productive things that aren't job related?	[ "Think of it this way: you have a limited amount of focus points. When you take the effort to do productive work, you spend those points. When you are taking time to do unproductive things(surfing internet, taking a break, etc.), it's just a way for you de-stress and replenish your supply of focus points. If you're...	[ "Words that often appear together are called \"collocations\", and it's simply the way we've learned them. We tend to process them as indivisible units -- phrases, rather than separate words. For example, when we say \"apples and oranges\", we're not thinking of two different kinds of fruit and then putting them in...
What is the coldest temperature you can drink something without harm?	[ "It depends what you are drinking. Honestly, most substances that would stay liquid at temperatures below -30C are probably going to be dangerous to consume at any temperature. There have been specious cases of people who have died drinking super-cooled beer that was liquid at time of drinking and then froze shortl...	[ "[Crazy Food Laws](_URL_0_) There are specific rules and regulations in how a company must list the Caloric information on their products. Calories must be listed in 5 calorie increments up to a total of 50, anything beyond that must be in 10 calorie increments. Weirdly, anything below 5 calories can be listed as 0...
Did the dinosaurus really go extinct because of a meteor?	[ "Short answer... we're not 100% sure. We _do_ know that most of the bigger dinosaurs abruptly died out 65 million years ago (where 'abruptly' means hundreds to thousands of years) and that a major impact hypothesis seems to fit the best. There are competing hypotheses, and growing support for a set of meta-hypothes...	[ "This is a pretty common question here; here's some links from the FAQ: _URL_2_ _URL_4_ and a few others that have been posted over the years: _URL_3_ _URL_1_ _URL_0_ Most posts agree that it is largely a post-war pop phenomenon with fairly little evidence to support it." ]
Why is it that when people close their eyes, there are faint splotches of different abstract things visible?	[ "They're called phosphenes. Apparently the retina produces them even when at rest and in the absence of light. It's sort of the same way that fireflies can glow; there are cells within our eyes that emit biophotons which are light particles that are produced by our eyes themselves." ]	[ "As a side note, I kinda already understand what causes the big green blob - the pressure on the optical nerve. But the actual patterns whooshing past is the big ELI5 here - how the hell does my brain end up interpreting it like that?! There's actual PATTERNS. Moving lights!" ]
What are the surface properties of a cooling dwarf star?	[ "White dwarfs are made out of electron degenerate matter. This is not really comparable to the 3 everyday states of matter (solid, liquid or gas) As it cools, it will become more dim, and eventually it starts to crystallice, but it will remain electron degenerate matter for ever. And no you could not walk on it, as...	[ "I recall learning something about how the intervertebral disc tissue loses moisture as it ages and this has a compressing effect which can actually shorten ppl by an inch or so. Healthy discs = firm and plump Old/diseased disc = dried up, shrunken. Counteracting it? Stay hydrated and take joint and cartilage hea...
Why is an i5 processor faster than an i3 processor if they have similar clock speeds?	[ "Think of the processor as a workshop. Inside the workshop, woodworkers represent the cores of a cpu. Multiple workers are going to get jobs done faster than just one guy In fact, it has been proven that multiple, slower workers will complete tasks more efficiently than just one really fast guy. This is why single...	[ "The three painkillers you're most probably the most familiar with -- aspirin, ibuprofen, and acetaminophen -- all work in roughly the same way, so I'll give a blanket explanation for all three. In your body, there's a family of enzymes known as cyclooxygenase (COX). Their purpose is to create something called *p...
If the U.S. has the industrial military complex, why are we in debt from the wars in the middle east?	[ "It means that industry and the military profit from war. The government as a whole doesn't." ]	[ "If you don't like spending more money than you have to, you'll only buy a car big enough for your needs. A bigger car is more expensive, and uses a lot more gasoline than a little car. You wouldn't buy a big SUV if you didn't need it. Lean muscle mass burns energy - it's expensive for our bodies to build it, and k...
Suetonius reported that Augustus had a height of "five and three-quarters feet." Are these the same feet we use today?	[ "The Roman foot was slightly smaller than the modern foot, at 11.65 modern inches." ]	[ "greetings all. Just a moderator reminder to potential respondents of what subreddit we're in here: it's /r/AskHistorians, so do review and comply with [the subreddit rules](_URL_11_). In a nutshell: > Answers in this subreddit are expected to be of a level that historians would provide: **comprehensive and inform...
Why are patent trolls much more prevalent now than they have been before?	[ "The \"Pixel\" takedown notice has nothing to do with patent trolls. That was DMCA abuse. Both DMCA abuse and Patent trolls have been fairly significant issues for several years." ]	[ "My guess? When you're dealing with a lot of makeup, prosthesis, special effects its easier to hide flaws. You can see acne under makeup in high def, you couldn't really see that back in the day. Just a guess." ]
Why is most life on earth divided in 2 sexes?	[ "I recall reading that for complex organisms in a competitive environment, two sex reproduction provides the genetic variability needed for competitive adaptation. Three sexes becomes unnecessarily complex - how can you be sure you'll find all three at once to successfully reproduce? Oh, and asexual reproduction (v...	[ "Inclusion of all the colors of the rainbow man :) Things are not just \"black\" and \"white\", heterosexual or celibate. There are a variety and ranges and shades of humanity and human sexuality." ]
How far down did the US Dollar go when the Arab oil producing nations boycotted America ?	[ "I'm no expert on economic history, but If I recall correctly while OPEC did boycott many western countries they still priced their oil by US dollars. The immediate effect was a huge squeeze on the international oil market, which is priced in dollars, and caused an increase in the value of the dollar. (higher price...	[ "Let's say toll roads are run by Wal Mart. They then offer a discount - you can drive to Wal Mart for free, but still have to pay a toll when you go anywhere else. Sounds good, right? But then next year they double or triple the toll. Soon you can't afford to shop anywhere EXCEPT WalMart. Every other store then go...
How common were independent Counties and Duchies in the 700's to the 1000's?	[ "By independent, do you mean by law or in practice? Do you mean within the Carolingian empire? The post Carolingian empire in Frankish lands? In Germanic lands? English? Italian peninsula?" ]	[ "> empirical powerhouse Did you mean imperial? Because something is empirical if it's based on verifiable information, I doubt that's what you meant. Anyway, your question has been answered before, have a look at these threads: [To what extent is Portugal just another one of the Spanish kingdoms?](_URL_0_) [How did...
Why are we are all bothered by disclosure of App permissions on mobile phones but not by softwares on Windows by developors?	[ "Because the types of permissions people are usually concerned about are usually... * Location data, either current or past * email, phone contacts The vast majority of laptops and all desktops do not have GPS chips, so location data isn't a concern. While people may store email addresses and phone numbers on their...	[ "Context is important. I'm not surprised to see a hot dog at a hot dog stand. I'd be surprised if I opened my wallet to pay for a hot dog and it only had a hot dog inside. I'm not surprised to see beach clothing at a beach, but would be concerned if I'm about to go into surgery and the surgeon shows up in a speedo....
If friction creates heat, shouldn't wind be warming the temperature when it blows by you rather than cooling you?	[ "The amount of heat caused by friction of wind is far less than the amount it dissipates by blowing the insulating pocket warmer air that develops around your body due to body heat away." ]	[ "Because it's diffuse. The air coming out of the fan is in a very narrow path - the fan's energy is pointing in one direction. The air going into the fan might be coming from anywhere behind it, not from any particular angle, so the moving air is harder to feel at any one spot." ]
If all humans switched to a plant based diet, and all meat, dairy and egg industries disappeared, how would this new and increased demand for plants based foods affect the environment?	[ "Corn is horrible for the soil, so we would probably have more fertile soil. We should be growing up, instead of in fields. Large greenhouses that go up many stories. Each city could have one big enough to sustain the community. We already know how certain plants are harvested, so we could use robots to pick the yi...	[ "Most Christmas trees are grown on tree farms, not harvested from forests. In order to get the ideal shape for the tree, the tree needs space to grow, must be trimmable, kept free of critters, disease, etc. A christmas tree takes about 7-10 years to grow, and during that period of time it is extracting carbon from ...
Does it take the same amount of gas to keep my home (or commercial building) heated to 65 degrees as it would at 45 degrees?	[ "Even if you have the best insulation possible, there is always going to be some heat loss. The greater the difference between the heated inside and the cold outside, the faster the heat will leave. So it takes more energy to maintain the higher temperature. The key thing here is the difference between the inside a...	[ "For Infrared Remote Controls: The RC5 standard specifies a 5 bit address before the command is send. The NEC standard specifies a 16 bit address before the command is send. So by giving the different appliances different addresses, the remote control only works on one. The \"shortage\" of addresses in RC5 (only 32...
Why do our eyes "burn" when cutting onions?	[ "Basically Onions contain sulphur compounds that are released when cutting them. The compounds react with the moisture in your eyes creating the irritation." ]	[ "You essentially create a battery in your mouth, the pain you feel is a small electric current. _URL_0_" ]
How much did China contribute to the end of Imperial Japan	[ "I would direct you to my answer on a related question: [How significant was the Second Sino-Japanese War in World War II?](_URL_0_) It must be emphasised that this is still very much a debated topic among scholars - Western and Japanese scholars tend to downplay the role of China in the larger Pacific War, which I...	[ "Whilst working on Part III of my Opium War series (coming out on the Saturday Showcase tomorrow), I noticed something a little bit fishy about Extra Credits' description of the Battle of Chuanbi in November 1839. Namely, that it seems to be lifted more or less completely (albeit largely reworded) from the descript...
Why do seniors get discounts, when statistically they're the wealthiest members of society?	[ "Because a good deal of them are on fixed incomes. Many seniors in the US would be homeless without social security benefits. I'm not sure about your claim of seniors being the wealthiest members in society." ]	[ "_URL_2_ columnist William Saletan waded into this issue several years ago with similar questions to yours. Here's an article posted AFTER his initial article and several followups, all of which can be reached via links within the article. It's an interesting journey with commentary from psychologists, statistician...
Is there any seismic activity on the Moon?	[ "Yes there is, but it is significantly weaker than on earth. In fact the Apollo 11 crew placed [seismic detectors on the moon](_URL_2_). The following [Apollo missions 12, 14, 15 and 16](_URL_1_) placed further detectors. The moon-quakes are typically about 2 on the Richter scale with a typical depth of 800-1000km....	[ "Edited: I have heard two things... * Rockets sent up to record various aspects of the test. * Vertical smoke flares which are used to observe the shockwave Edit 2: [Seems like it is a combination of the two](_URL_0_): > Sounding rockets or smoke flares may be launched just before a device explodes so that their v...
What are the fundamentals and basics of Islam?	[ "Well I don't know much, but I know the Five Pillars of Islam are like the Ten Commandments for Christians and Jews. According to Wikipedia, here are the five pillars Shahadah: declaring there is no god except God, and Muhammad is God's Messenger Salat: ritual prayer five times a day Zakat: giving 2.5% of one’s sav...	[ "as a follow-on question: I've heard of \"ritualized\" battles in some of the less developed parts of the world--remote pacific islands, rural africa, and the like. Is that true? What was the purpouse of such a ritual? what kinds of casualties were there? edit: as an aside, I'm pretty sure the WW1 \"live and let ...
How "If you like your healthcare plan, you can keep your healthcare plan" became evident as untrue. What happened to make this untrue?	[ "When the ACA was first proposed, officials said, \"In most cases,, if you like your healthcare plan, you can keep it.\" The reason for this qualifier is that all insurance companies are required to meet certain standards, and if someone had a plan that didn't, they could not keep it. Unfortunately, Obama left ...	[ "Karl Rove once challenged Dwayne Wade to a 1:1 basketball game. Wade was obviously the overwhelming favorite, but Rove convinced Wade that the best way for him to win was to let Rove's points \"trickle down\" into Wade's basket. Rove won 184-2." ]
Is drinking water from a few days old water bottle really bad for you?	[ "I'm not sure what the concern of OP is. If the concern is contamination from the plastic: (1) older polycarbonate bottles do leach out low levels of BPA (there is some evidence this isn't good for you). One bottle won't make any difference, but it might be a good policy not to let water sit in such a bottle. Most ...	[ "One thing to keep in mind was the reuse of arrows. Arrows were commonly gathered after battles and retooled or simply re used if they were not in poor shape. This lead to a couple things, first it lowered the cost of needing new arrows, second, if the arrow struck ground or other unclean things, it allowed for a b...
Why does it feel like your phone is vibrating when it is in your pocket but doesn't really vibrate?	[ "It's called phantom vibration! And you can get phantom sensations of all sorts - phantom sounds, phantom feelings, phantom smells, phantom sights... It has something to do with the fact that the brain is a pattern matcher. It creates patterns and likes to find patterns in things. It uses saved patterns to recogniz...	[ "I'm only speculating but it could be Pavlovian response. You've probably heard of Pavlov's dog where the scientist would ring a bell and then give the dog some food, repeat, repeat, repeat. Eventually the dog would associate the bell with food and begin salivating at the sound of the bell, whether there was any fo...
Why do so many medicines require you to stop eating grapefruit?	[ "PSA: effectiveness of oral hormonal birth control (the pill) is inhibited by grapefruits and grapefruits juice. So do not eat grapefruits or consume grapefruit products if you are on the pill. I know this doesn't answer OP's question but many others have answered it and I thought this was an important point to bri...	[ "Marketing basically. Decades and decades of TV ads hammering home the idea that if you want to be seen as a normal successful member of society, you drink orange juice in the morning." ]
Why does it take our eyes so long to adjust to the dark?	[ "Two things happen when you move from a bright space into a really dark space 1. Your pupil opens up which allows more light to enter your eye. If you enter a really dark space your pupil will open to full diameter 2. Rhodopsin starts to return to normal in the rods in your eyes. Rhodopsin is what actually detects ...	[ "The human brain is great at recognizing patterns and is very used to making predictions about the environment. For example, due your experience, when you're walking in the street your brain tells you \"people are walking in a certain direction and they're going to keep doing so\". When you experience something new...
How is spacecraft controlled over such long distances? How do scientists factor in obstacles such as asteroids?	[ "Preprogrammed commands with meticulous planning ahead of time. Asteroids are not obstacles space is tremendous and its hard to hit something on purpose and nearly impossible to hit anything on accident." ]	[ "Math. After we were able to accurately monitor and figure out the body's course it was simply (not that simple) math and physics that told us where it would go. (EX: at day 12 month 5 yr 1981 it was here, on day 27 3rd month yr 1984 it was here, insert big math problem, and we now know that on day 1 month 1 yr 198...
Libertarians in the Confederate States of America	[ "Not sure if libertarians is the correct term to use here, he maybe referring to the likes of North Carolina governor Zebulon Baird Vance and Georgia governor Joseph E. Brown both of whom resisted Jefferson Davis and were believers in state's rights. Brown was particularly bad, trying to prevent Georgia state troop...	[ "hi! Could you clarify the scope of this question? Are you mainly asking about practices in Scotland / the British Isles roughly around the Civil Wars, or landowners anytime anywhere? [hint: [say the former](_URL_0_) ]" ]
Why do towels have a band without fuzz on each end?	[ "It is there so the towel does not fall apart over time. There are two reasons for using this stitch over the regular \"fold-and-stitch\" version: * the fabric is very thick so it would give a very fat fold at the end which does not look appealing * the frothing does not make it very easy to handle * as there is no...	[ "It's required by many jurisdictions laws to identify source/etc. They're typically put on when packaged automatically not by hand and many lose fruits don't have them anyways [in my experience anyways]" ]
Why is history important?	[ "hiya, this question has been asked here a few times. I've picked out some with longer answers; check them out * /u/Polybius in _URL_4_ * /u/Borimi and others in _URL_1_ * /u/bitparity and /u/TheGreenReaper7 in _URL_3_ * various users in _URL_0_ and _URL_2_" ]	[ "It sounds silly without context; it's easy to understand and repeat." ]
Social Mobility and the Black Death in Asia and other non-European locations?	[ "Before asking whether the Black Death had an impact on social mobility in \"Asia and other non-European locations\", we really need to ask if the pandemic actually struck Asia and other non-European locations. The evidence is meagre (telling in itself, I think), but there is good reason to think that in fact the p...	[ "I think you meant \"1492,\" but in any case, that question's been answered quite a few times here. The short of it is that Russia didn't have the territorial expanse it has today ─ Siberian expansion didn't really start until the 16th century ─ and as far as we can tell, Chinese, Korean or Japanese traders didn't ...
I work in a deli. One of our refrigerator windows has exploded without reason. This is the second window that has exploded like this in less than 3 months. How is this possible?	[ "Hmmm...not really sure, but IMO, has something to do with an extreme temperature difference between the fridge and outside, and/or excessive stress. Is there something stored in front of it was would cause excessive heating? Blocking the area can prevent proper airflow around the intake causing overheating. If its...	[ "As the OP have mentioned in a comment above, fast moving fluids, in this case air, have lower pressure. Animals breath by expanding the chest cavity which causes the pressure surrounding the lung to lower. This causes the higher pressure outside air to rush in and inflate the lung. But if the pressure outside sudd...
; Why is Jesus on a cross the symbol for the religion and used against demons?	[ "Jesus on the cross is dying for our sins, to absolve and protect all the rest of us. He protects us from our own \"demons,\" that is, our sinful nature. Remember, being crucified didn't destroy Jesus. He was resurrected shortly thereafter. It was merely an ordeal he went through on our behalf. I think I've got thi...	[ "The Dow is just a number of companies' stock price added together. The list was made quite a long time ago, and it's supposed to be a good indicator of the New York Stock Exchange as a whole (when it's up, the market is up, when it's down, the market is down, etc). Whether you think it's a good representation of t...
There is evidence that shows children who grow up without a father figure tend to exhibit more negative behavior. Is there evidence linking the same behavior occurring if the child grows up without a mother?	[ "Can you cite this? Maybe you've seen a more up to date study then me, but I recall reading several studies that show children of lesbian couples (hence missing a father) aren't significantly different from male/female or male/male couples. The more important factor is whether there are 2 parents vs 1... For singl...	[ "Wet nurses weren't only in existence in countries with nobility. Wet nursing was for a long time more about affluence and family wealth than noble title. In fact, the history of wet nursing can be traced back to ancient times. The United States has a history of the use of wet nurses, and many women who were alive ...
How does one read a QR code's data?	[ "In theory you can, the [wiki page](_URL_0_) has a walk through of how the data is laid out and how decoding works. You'll be much slower than a computer because it's designed to be easy for a computer, which is good at things that your brain is bad at (and vice versa). You're good at pattern matching - recognising...	[ "Try _URL_1_. They have some short tutorials and online algorithms you can use to examine photos. I've used the site on occasion to check if some Reddit images are faked. Very informative site. Also, check out captain disillusion on _URL_0_. He debunks videos which have been altered and explains how he determines i...
Is factory unlocked smartphone same as unlocked using a code?	[ "Once a phone is unlocked, its unlocked. It doesn't matter how the unlock happens, as long as it does." ]	[ "I had never heard of this before but 90 seconds of googling gave me this; \" In general, \"industry plant\" is a pithy derogative that we (haters) wield to imply that a rapper or singer is an upstart fraud, a record label puppet, a focus group-tested vessel of creativity so-called. Any musician with a hazy or stra...
Why does air hitting you feel cool, even when hot	[ "I'm pretty sure part of it has to do with water (sweat) molecules being knocked off of your skin (evaporating) more easily, and water evaporating off your skin takes some heat with it, which is why you sweat in the first place" ]	[ "When you close the door, a bunch of air is displaced, and it has to go somewhere. If you don't have a window open, the only place the air can go is to rush out the door gap as you're closing it. This is difficult to do, and so the air forms a higher pressure \"cushion\" which prevents the door from closing as hard...
How did the guy on America's Got Talent swallow sugar and then water after that and regurgitate the sugar still dry with no water?	[ "He's covering the sugar in a hydrophobic coating. Scotchgard is a common one. [Here](_URL_0_) is a video of sand with a hydrophobic coating. Note that when he picks it back up out of the water, it's dry. This happens because water won't stick to or penetrate a hydrophobic surface. So, the sand/sugar stays \"dry\" ...	[ "You can hear things because there is a thin “drum” in your ear that sounds make vibrate. Your brain feels those vibrations and you experience it as sound. Air cannot go through that ear drum, just like a normal drum. Air gets to the other side through a different hole deep inside your head. The amount of air aroun...
How far back can we trace the stereotype that Northern Europeans are reserved and punctual and that Southern Europeans, in turn, are expressive and more relaxed about time?	[ "Follow-up: In Roman sources, Northern Europeans are depicted as undisciplined and impulsive, quick to anger, deeply individualistic, and resentful of authority. And the Romans depict themselves as patient, organized, disciplined, and focused. Now, this isn't really an inversion of OP's question, but I would like t...	[ "This is more a practical than culinary concern. Cured meats last longer in warm climates like Spain, whereas this is less of a concern in the colder German climate. It is similar to why colder countries drink beer and warmer climates drink wine: grapes grow better in warm countries and barley grows better in cold ...
When you practice something how does your brain know which goal is desirable? How does our brain determine that we're progressing and which route to pursue?	[ "Neurons are always making and breaking connections (it's called neural plasticity). One model is that dopamine reward contributes to the reinforcement of the times you do it right. The more times your brain experiences the little dopamine hit from accomplishing whatever it is you are trying to do, the more the neu...	[ "How exactly did labor markets (or whatever was in their place) function in the USSR? How did planners determine what was being paid (if this is a fair way to characterize it)? Did wages differ by trade/region/labor supply, and if so, how was this decided?" ]
How can a company like Netflix charge less than $10/month to stream you literally thousands of shows, yet cable companies charge $50 /month and we still have to watch commercials?	[ "Part of it is what other people are saying about how Netflix doesn't maintain the cabling etc and that is handled by the internet company. What doesn't seem to be mentioned yet though is that Netflix gets most of its content after it has already been milked for as much money as possible. Judging from my experience...	[ "Because a novel is usually 200-500 pages and then an ending. It's possible to cram most of what happens in that novel into the movie without missing the best part, or skipping over anyone's favorite character. In the case of superhero comics, they usually go on for years and years, with dozens of plotlines and cha...
Why was the Roman Empire able to take England but could not push into Scotland?	[ "Oh but they did. Granted, they didn't hold it, but a man by the name of Agricola invaded Scotland (Caledonia) in [78 AD.](_URL_0_) The Romans also invaded Caledonia in 208 AD under Septimus Severus. Long story short, the reason they couldn't hold it was because of the A) guerrilla warfare used by the Caledonia tr...	[ "Although you have received very complete answers, I would like to point out some more (although I am not a historian). From pre-Roman times you can find several archeological remains such as the [bulls of Guisando](_URL_3_), the numerous Celtic villages in the North of Spain and in Portugal, called [castros]( _URL...
Why can’t you take a pulse with your thumb?	[ "Like all body parts, your fingers and thumb have arteries supplying them with blood. The fingers have two arteries supplying them from the side, but the thumb has a single artery running through the middle. When you use your thumb to feel for a pulse, especially one that is absent or weak, you risk feeling your ow...	[ "Each of the bills have slightly different details the machine can read. As far as coins, it's done by weight and, if you can get a slug the same size/weight as a quarter, you can probably \"fool\" the machine." ]
How does India simultaneously have one of the world's most advanced technological meccas yet also has what looks like one of the world's unhealthiest civilians?	[ "We're talking billions of people. Let's look at the US, which is also a technological mecca and home to millions of people so fat their heart stops. We still have millions of poor people, homeless people, etc. Now imagine all those problems multiplied by 4." ]	[ "My guess? When you're dealing with a lot of makeup, prosthesis, special effects its easier to hide flaws. You can see acne under makeup in high def, you couldn't really see that back in the day. Just a guess." ]
How are primary colors made, if you can't technically create them with other colors?	[ "The pigments come from materials that are already that color. For example, some minerals like red chalk can make colors, cinnabar is red, and this is also a mineral. Most of them get made synthetically now, but some chemicals will just reflect a specific wavelength of light, and that's how you get pretty much any ...	[ "It's called spectroscopy. Simply put, when light go through an element like hydrogen, the atoms will absorb different wavelength of the light. When you analyse the spectrum of light that when through hydrogen you will see a couple of black line where the wavelength were absorbed. It's a bit like the fingerprint of...
Just like in supersonic motion, the object that creates the sound can move faster than the waves it produces, is it possible for the E-field or B-field that make up light to move faster than the light?	[ "The light (i.e., the electromagnetic wave) is the E- and B-fields. So the answer to your question is trivially \"no\"; something cannot travel faster than itself. But perhaps you mean to ask whether a source of light can travel faster than the speed of that light in that medium. So, for instance, can an underw...	[ "While not really scientific conceptually this works. Think of the difference between how fast you move and the speed of light as the speed of time. So your speed + 'speed of time' = speed of light. So people on Earth move so slow compared to the speed of light that the 'speed of time' basically makes of up all of ...
What defines the maximum and minimum wavelength of electromagnetic radiation?	[ "There is no maximum or minimum wavelength, any wavelength can be transformed into another one with the right choice of reference frame. A possible exception to this is if quantum gravity breaks Lorentz symmetry, and then there will be some minimum Planck-scale wavelength." ]	[ "Because the FCC is who allows you to transmit over the air, they allow manufacturers to make devices that transmit in certain bands depending on what the device does. WiFi and Bluetooth are relatively new technologies, before this the 2.4 GHz band was considered useless because it couldn't travel very far and was ...
Does the size of the screen effect the size of the file I am streaming?	[ "It depends on how you are streaming it, if you access a video file directly, and stream an mp4 off my server that I serve statically then you will stream that file in whatever format I have, regardless of the capabilities of your device. Most smaller websites will stream video like this because they only encode fi...	[ "First off, don't use the term 'leech' - it implies that you do LOTS of downloading. Second, you won't get a dismissal; the MPAA/RIAA would LOVE to get a court ruling that says you can't download copies of stuff for which you own (other) liceneses." ]
What would happen if an important character on a TV show died mid-filming?	[ "If you watched the sitcom News Radio you'd see an example. Phil Hartman was killed while the show was still in full swing. The writers killed the character off-screen with a heart - attack and wrote in a replacement character." ]	[ "News and scheduled programs have different airing times for the different time zones. Live programs (sports, or a presidential debate or something) are scheduled so as to attempt to be convenient for everyone. This often ends up being rather late on the east coast, and inconveniently early on the west coast. I don...
Legality of using real life people in fictional stories	[ "Famous people can and often do copyright their own image and likeness in order to prevent this from happening, and for people who have done so you must go through their estate even after death. Lincoln never did this, and neither did most of the long dead famous people you see on TV." ]	[ "Unfortunately all of the examples I can think of would break the 20 year rule, but the answer is \"Yes\" it happens all the time. _URL_0_" ]
Effects of same-sex, married parents on their children?	[ "For an excellent scholarly update on this hot-button issue, read [\"Promoting the Well-Being of Children Whose Parents Are Gay or Lesbian,\"](_URL_0_) from the April 2013 Pediatrics, the journal of the American Academy of Pediatrics. The AAP advocates for healthy child-rearing environments, and strongly supports...	[ "Since this is a homework question, we expect a little more effort from you. What research have you done so far for your paper? What are your findings so far? Is there anything specific you have a question about?" ]
Is there a reason why our bodies know when to wake up if you go to bed with a time in mind?	[ "The hour or so before waking up, your body starts to release adrenocorticotropin (ACTH). Normally this is dependent upon the circadian rhythm. However a [study](_URL_0_) done in Germany showed evidence that the release of ACTH is not confined to daily rhythms. They found that \"Anticipation, which is generally con...	[ "I think it is hardwired into us. [Tommy Edison](_URL_0_) explains it better." ]
Has there been a social issue as large as racism, sexism, classism, etc. in past that has been totally eradicated?	[ "Sorry, we don't allow [\"trivia seeking\" questions](_URL_0_). These tend to produce threads which are collections of disjointed, partial responses, and not the in-depth discussions about a particular topic we're looking for. If you have a specific question about an historical event, period, or person, please feel...	[ "That would be the idea. It's all herpes zoster infections - shingles is just the recurrence of the same infection. When there are no new cases of chickenpox then, eventually, there would be no new cases of shingles. But it'll take a long time - all the people who have had chickenpox need to get old and die and all...
How does a calculator process square root?	[ "They normally use a process called the Newton raphson method which is as such: Xn+1=Xn-(f(Xn)/f'(Xn)) Essentially, the next term in the sequence is given by the previous term minus the value of the function at the previous point over the gradient at the previous point. It can be repeated over and over til you get ...	[ "I know that if it doesn't get it right it asks you type in the solution. Maybe that's how all the answers were fed to it except for the first 1,000 names the developers might have put in to get a prototype." ]
Why do some wars in Africa have such bizarre twists?	[ "- Cannibalism was noted in some South Pacific, north/south American and Caribean cultures. - There were child soldiers used in various roles in [Colombia](_URL_2_), and in [Chechnya](_URL_2_), among many other non-african nations. - I would be surprised if there was any culture on earth where cross-dressing or str...	[ "From the exact same XKCD article that you linked: > (Climates can be hard to predict—for example, in our world, Somalia and French Guiana both sit on the equator, at the eastern coast of a continent, and seem like they should both receive a tropical sea breeze. But coastal French Guiana is dense rain forest while...
How did we establish the universal rule of 'righty tighty lefty loosey'?	[ "Most people are right handed. Screws take more force to insert than to remove, and righty-tighty screws allow to use your right hand in its strongest position. Thus it's preferable to the other direction, which is now rarely used." ]	[ "Sound was, and is, fairly easy to approximate, even high school students can walk across large fields and measure the difference in time between when they see their friend bang a gong and when they hear it half a mile away, if not ideally farther. The same measurement can be made watching fireworks if you know the...
If my headphones have bigger speakers will the battery life on my iPod drain faster?	[ "Ramast's answer is incorrect. Changing the volume doesn't change the output power, it changes the output voltage range. At a constant volume level, if you switch to a set of headphones with twice as much impedance, you'll halve the sound output, but you'll also halve the power consumption. The parameter you care a...	[ "So they have your attention, the chances of it skrewing with the plane are slim to none (plus many have airplane modes that eliminate any outgoing signals) they use this excuse because again they want you full and undivided attention during takeoff & landings" ]
How do we measure things like diameter, mass and chemical makeup of distant objects such as asteroids?	[ "You can estimate the composition of objects that emit or absorb/reflect radiation (light, IR, xrays) by looking at the spectral signature of the radiation. There are some examples at the wiki page on [astronomical spectroscopy](_URL_1_). If the asteroid orbits another asteroid, then we can use what we know about o...	[ "Generally they spend months and months finding where the pieces of the spacecraft fell, analyzing weather data, analyzing footage of the disaster, and looking at the black box which records what the crew is saying as well as system diagnostics. After some extremely thorough analysis they can come to a conclusion ...
What was the mindset of Irish immigrants in the 1880's (and other eras) regarding Jews?	[ "A little later than the 1880s, but you may find it interesting to read about [Abie's Irish Rose](_URL_0_), a 1920s play about a Jewish-Irish Catholic intermarriage in which the ways Jews and Irish people saw each other was mined for laughs. Not only is the play itself a good source of the stereotypes and preconcep...	[ "I'd like to help, and I'm sure I could come up with something, but I'm not sure I fully understand what you're looking for. Are you looking for a book, journal article(s), or something else? And, are you looking for information on one event in the Israeli-Palestinian conflict, or an overview of it? I can say defin...
What happens to the immune system after extensive blood transfusions?	[ "Immunity involves the innate response and adaptive responses. The innate response occurs first and is non specific whereas the adaptive response comes later, is specific and involves memory cells formation . When someone is 'immune', it means that those memory cells have formed so can quickly respond and are espec...	[ "One theory is that [we're too clean](_URL_0_). By keeping our kids clean and not letting them chew on UFOs (unidentified floor objects), we're either preventing their immune systems from building a proper \"database\" of pathogens early on, or we're preventing them from coming into contact with symbiotic species t...
Unusual invasion routes of WWII?	[ "It's not a road, but the choice of invading Normandy over other places on the French coast was somewhat unusual. The closest place in France to the English coast is Calais, and indeed, Allied intelligence did their best to mislead the Germans into thinking the invasion would land at Calais." ]	[ "There was a quite good documentary ([Kanalinseln im Krieg](_URL_4_)) on german television a few weeks ago (I just found, it's at least a year old), and I don't know if those ever get translated into english. But it might be a starting point, and maybe you can find a subbed version on the net the [BBC](_URL_5_) has...
I'm a pirate in the late 1600s-early 1700s. What sort of rum am I drinking, and how similar or different is it to rum today?	[ "[Hi! This answer from /u/WARitter may be helpful!](_URL_0_)" ]	[ "> Even if one or two hit, would that have really mattered? Didn't ships go toe to toe with broadsides weighing in at 70-100 guns? Would even a dozen hits from the fort do anything substantial? You are thinking of Napoleonic naval warfare, in which, yes, ships would fire several dozen guns at each other at point-bl...
How do phones and computers transfer audio to headphones?	[ "Sound is transmitted as a voltage signal through wires. The voltage changes just like the soundwave, and this goes into tiny magnets in headphones, or speakers, or telephones. The magnets shake the speaker back and forth as the voltage changes, and this movement makes pressure waves on the air. The pressure waves ...	[ "[Sennheiser](_URL_0_). I would endorse anything they make, including the cheapest pair which is likely better than more expensive Beats branded ones. This brand is used by actual professionals, so you won't look like a trend chaser. IMO over the ear is always the way to go, despite how it makes you look like an al...
Why is there such hate/mockery towards hippies?	[ "Hippies are sometimes perceived as lazy mooches who live off a successful society but don't want to do the things that make it successful. They are also sometimes perceived as having poorly thought out political and social ideas that are unrealistic. Also, their aesthetic is sometimes seen as dirty (literally, ung...	[ "\"Just about everyone here\" Where is \"here\" for you? It sounds like your question's premise is based on a small sample set based on personal observation. Before your question is addressed, you should be making sure the premise is valid..." ]
The birthday problem	[ "That's not what the birthday problem means. It means that the probability that at least 2 of those 75 people share the same the same birthday is over 99%." ]	[ "There are 1 billion ways to arrange the 9 digits in a SSN. Eventually, we'll run out. We're not there yet (even though the government actually doesn't use all 1 billion of those numbers by convention)." ]
What would happen if a large meteorite crashed into one of the "gas giant" planets.	[ "How would an [example](_URL_0_) work for you? If you google shoemaker levy 9, there's even video!" ]	[ "First, an aside on black holes: Whether the progenitor becomes a black hole or not is irrelevant - the gravitational fields of a star and a black hole of the same mass are the same outside the surface of the star. In other words, at large distances, it's just as easy to orbit a black hole as it is to orbit a star...
Why do humans eat wheat?	[ "Hi OP, this question on \"early humans\", the practicality of grain in the human diet, and the development of agriculture would be worth x-posting to our sister sub, /r/AskAnthropology." ]	[ "Most people in the United States don't speak like this, but this used to be the way most English speakers used to speak. Wine and Whine used to sound different. At some point a lot English speakers dropped the H sound. From what I understand, the \"H\" is still around in England, particularly in the north. In the ...
Why does splashing cold water on my face calm me down?	[ "That's the [mammalian diving reflex.](_URL_0_) Basically, it forces your breathing and heartbeat to slow down, which resets your psychological state." ]	[ "The rate at which a human brain processes information is not constant. It changes based on a number of factors. When you feel a sudden threat, your body releases hormones that trigger a change in the rate at which your brain can process information. If your brain is processing information more quickly, your percep...
Different sizes of infinity	[ "The key idea is that this isn't about numbers: there is no number infinity. Just saying \"there are different sizes of infinities\" doesn't really mean anything unless you have a well-defined notion of \"size\" and \"infinity\". Rather, this is about cardinality, which are simple \"equivalence classes of sets\":...	[ "A Farnsworth Fusor will easily fit on your desk, and is well within the realm of a highschool Science Fair project. However it will never hit break even energy. The amount of material in the plasma is on the order of micrograms." ]
Is it true that pockmarks from smallpox were once fashionable in China?	[ "In [Plague, Fear, and Politics in San Francisco's Chinatown](_URL_0_), Risse provides the following in reference to practices and attitudes in China at the time: > Most villagers, however still practiced the instillation of a powder made from dried smallpox scabs. Instead of conferring immunity, this strategy o...	[ "As a followup question, what \"image\" did they project? By this I mean, was it like a sign of nobility? Was it to show loyalty to a particular faction/religion/craft? Was it considered low class or as brands for criminals? Thank you. Cool question OP." ]
I understand how neurotransmitters like serotonin, dopamine, norepinephrine affect mood, but how do hormones like estrogen, progesterone, and testosterone affect our moods?	[ "This is a complicated issue and it differs for each person, but yes, these hormones affect neurotransmitter levels and act as neurotransmitters themselves. Estrogen is generally a mood elevator at best, but at worst makes you agitated. It’s a stimulant. Progesterone has a neuroprotective effect and at best makes y...	[ "Both testosterone and hgh play a role in penis growth. T and hgh levels during puberty strongly correlate with penis size, and t and hgh treatment even has some effect in penis size for adults with normally developed penises. _URL_1_ _URL_2_ _URL_3_ _URL_0_" ]
Why does skin get itchy when it's re growing after say a cut or scrape?	[ "The itchy sensation you feel when a wound heals is coming from sensitive nerve cells, their job is to signal to the spinal cord that an area of the skin is being irritated in a way that we would perceive as itchy. the nerves are reacting to both chemicals being released and structural stretch on the surrounding sk...	[ "The general consensus is [attention and approval seeking](_URL_4_) or [medical issues](_URL_1_). In [domesticated animals](_URL_2_), the approval seeking is generally from the owner. Because we see this in wild animals as well, it can't just be a human-approval mechanism. The attention seeking can be extended to t...

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