Subset (10)

eli5 · 25k rows

Split (1)

train · 25k rows

query stringlengths 20 300	positive listlengths 1 1	negative listlengths 1 1
Does the fact that animals are camouflaged to human eyes mean that most animal eyes are similar to ours?	[ "1. Even if you are camouflaged (a better word is cryptic) in the visible spectrum for humans, you might not be cryptic in the ultraviolet spectrum. Bees can detect UV light, and many bee-pollinated flowers have UV patterns that indicate \"landing zones\" for the bees. I'm not sure what a specific example would be ...	[ "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 ...
Who was the last king that actually fought for and won the English crown? And is the current royal family direct descendants of that king?	[ "That would be William of Orange, who deposed James II at the invitation of England's Protestant lords. At first they wanted to make his wife, Mary, sole ruler, but William insisted (backed by Mary) on being fully vested as king in his own right. After Mary's death, William ruled as sole monarch for eight more year...	[ "How would we know what an \"average citizen\" thought? Every text we have is produced by the elite class. Whether people lost friends or family is impossible to know in the specifics. We do know that military disaster did not affect the political careers of the generals involved. Rosenstein in Imperatores Victi ...
How did Hitler win over the whole of Germany?	[ "At the time Hitler began his rise to power, Germany was still reeling from it's defeat in WW1 and subsequent sanctions. It had lost a lot of territory during the war and was experiencing runaway inflation. Hitler came along with his over the top nationalism at just the right moment. Germans were tired of the treat...	[ "A common old expression in business is \"one throat to choke\". It means that when things go wrong, you want one individual, not two or some group or committee, that you can point at as accountable to fix it or accept accountability and any recompense for the problem. It's a lot easier to do it with an individual ...
How long does it take for the brain to register pain?	[ "Location will play a role (the longest nerve axon in the body is from the big toe to the low back) and the type of pain perceived (what kind of nerve cell is activated A or C fibers). Obviously greater distance to travel will effect how long it takes to register the injury. According to[ this WashU site](_URL_0_) ...	[ "It is much more complicated than that, and is a very active area of research. A professor at my school, David Eagleman, studies this stuff. He's a complete badass, check him out: _URL_0_ edit: one of his famous experiments involves using magnetic energy to slow the propagation of some signals in the brain, and i...
When exactly does a Vehicle Registration Sticker expire? Beginning, or End of the expiration month?	[ "You should look at your state laws as they may differ, but it generally expires on the last day of the month printed on the sticker. Many people wait until the end of the month to go to the DMV or to get their vehicle inspected and this can cause additional stress/delays. It's best to take care of these things ear...	[ "Previous reply was pretty close. \"W\" is often referred to as winter or more specifically cold, this is the viscosity of the oil when it is cold. The 2nd number is the operational viscosity, or how well it flows once heated. It's is best to put the recommended oil weight in a car. Truth be told there is a complex...
Does the amount of energy a creature requires contribute to the length of it's life?	[ "There are many things that can contribute to life spans, lifestyle, metabolism requirements, genetics. Telomeres are one genetic control on life span, and is specifically why [lobsters can live for such a long time](_URL_2_). In some cases, it may be a [single gene](_URL_1_). If you're interested in a thorough rea...	[ "From [visual tim]( _URL_0_) I don't see why hummingbirds wouldn't operate faster. The hummingbird's metabolism is what fuels their high speed, and their nutrient rich diet supports it. If their nervous system can perform at such high speeds, it stands to reason their brain could. I wasn't going to mention this wit...
Your favorite Biography's of historical figures?	[ "I would recommend Hannibals Dynasty: Power and politics in the western Mediterranean by Dexter Hoyos. It goes in to fantastic detail about the groundwork Hannibal's father (Hamilcar) laid out for his son-in-law Hasdrubal and his heir Hannibal. The bulk of the book is about Hannibal and his exploits. All the dirty...	[ "This submission has been removed because it is [soapboxing](_URL_1_.), [promoting a political agenda, or moralizing](_URL_0_). We don't allow content that does these things because they are detrimental to unbiased and academic discussion of history." ]
What is a good collection of books for someone with little history knowledge to learn the gist of history?	[ "Book recommendations (you wanted a long list...): * A World History (by Ponting) * A History of the Modern World * Human Drama: World History from 500 to 1450 * The Heritage of World Civilizations * Why the West rules for now * Guns, Germs and Steel * The World That Trade Created * Carnage and Culture * Aft...	[ "Hi - we as mods have approved this thread, because while this is a homework question, it is asking for clarification or resources, rather than the answer itself, which is fine according to [our rules](_URL_1_). This policy is further explained in this [Rules Roundtable thread](_URL_3_) and this [META Thread](_URL_...
What gives us the urge to "boop" the noses of animals?	[ "Because humans like interacting with stuff we like; interacting with a cute animal face is satisfyingly achieved through the booping process" ]	[ "Do you ever repetitively click a pen? Or jingle the change in your pocket? Or chew your nails? Or throw a baseball with a friend or your kid? Or play with a stress ball? Or... Or... or... or... Why do people do those things? I think you're right that you're probably over thinking it and it's just a toy." ]
Will I generate more power if I focus sunlight with a magnifying glass onto a solar panel?	[ "If your magnifying glass is bigger than your solar panel you will get more power. The lens would collect over a larger area than what the panel is able to do on its own. However there is a couple of things to consider. First the solar panels efficiency drops with temperature. So usually a 2m^2 panel would produce ...	[ "While common sense says \"No\", newton's third law and all that, Mythbusters have actually proven that it DOES work due to some clever physics. Its similar to how old ships used to sail against the wind and all that." ]
Why we have two types of screw heads/drivers?	[ "Flat heads are easy to use by humans, they have 2 downsides. The first is that the bit slips horizontally and falls out of the screw. They tend not to strip very easily, both bits and screws are simple so they are cheap to manufacture Phillips heads exist because the flat head does very poorly when you have a mach...	[ "If everyone has the same ideas, you have a shallow pool of ideas from which to draw. If you have people from lots of backgrounds (and I don't mean just racial) you have more chance of finding solutions your shallow pool would never have thought of." ]
Say you were in a car going 30mph North and the wind was going 30mph North. If you stuck you hand out of the window, would you feel air resistance, or any resistance?	[ "No you would not feel any resistance. This phenomenon is common in sail boating while running down wind. Autos are usually running faster than the wind so usually you feel the resistance but if you match the speed of the car to the speed of the wind there will be no resistance to feel. When you think about it this...	[ "There's no hole being made. Think of it as the same thing as a swimmer in a pool of water. The closest thing you can do to \"making a hole\" in the water is, like, belly-flopping into the water...but the cavity made by the body entering the fluid only exists for a tiny amount of time. To even call it a \"temporary...
Is bad eyesight caused by staring at the television for too long or it's just a myth?	[ "Current understanding is, that one factor in getting Myopia (short-sightedness) is [not being exposed enough to natural outdoor light](_URL_3_). So the myth around staring at the TV will get you bad eyesight has some basis in the fact, that at this times you are indoors and exposed to artificial lighte...	[ "I think the responses you've got so far indicate that it isn't very reliable. The whole thing is based on a sample. A sample of people are given set top boxes that monitor what they are watching. This sample is then scaled up to the whole population with weighting bias added in so that they can account for the 'av...
Why are student loan refinance rates often lower than mortgage rates even the principals can be the same?	[ "The main reason is that they have short payback schedules, so shorter risk/inflation horizon. Also, they aren't dischargeable by bankruptcy." ]	[ "There are. Before I got my current job I was looking at both electrician and HVAC trade schools (pullig from my GI bill). There are also welding, plumbing, and cosmotologist trade shool programs, off the top of my head. Architecture and Engineering are Masters and Batchlors-level college degrees respectively in th...
With the amount of care needed as an owner to keep your dog healthy/alive (i.e. shots, Heartguard pills, etc.), how is it that primitive dogs were able to be so self-sustainable as a species prior to becoming domesticated?	[ "Neither. We've simply adapted our medical technology to help our pets live longer than they used to. Just as humans lived much shorter lives around the time that dogs were being domesticated, so did dogs. As our diet and technology improved, our lifespan increased- and we brought the same attention to our companio...	[ "Evolution isn't about being smarter or more \"advanced\". It doesn't matter how smart a deer is if it can't outrun a wolf. Evolution, pure and simple, is about the propagation of genes (reproduction). Ants are highly successful, but they are almost pure instinct. Dolphins are pretty smart, but they're endangered. ...
Can someone help me understand the Kolmogorov–Smirnov test in normal everyday language?	[ "Okay think about it like this. Suppose you have a liquid and you don't know anything about it. You want to know if it's water. So you take an 1/8 of a gallon of water and weigh it. Then you weigh 1/8 gallon of the mystery liquid. Then a quarter gallon of each, then 3/8 gallon of each and so forth until you've we...	[ "Suppose you, as a lawyer, have successfully put away hundreds of criminals. Within the boundaries of the law. Now, you're caught doing it illegally once (e.g. bribing a jury). Every criminal you ever put away can now appeal their original sentencing, claiming that they fell victim to the same jury bribing th...
Why don't the contents of human's stomachs come out when we are flipped upside-down?	[ "The stomach has sphincters, ring-shaped muscles which constrict passage through an opening, at both ends. If you're turned upside down, the lower esophageal sphincter prevents fluid from flowing into your esophagus." ]	[ "Teleost fish (bony fish, ie not sharks or their relations) control their buoyancy with the aid of a swim bladder. This is an organ that can be filled with gas by the fish, to a varying degree, to maintain its depth without having to swim (automatically, the fish doesn't control it). When the fish dies, the decompo...
Mendel's Laws of Inheritance	[ "1) The Law of Segregation states what you already seem to know: you get one allele per trait from each parent (the \"segregation\" bit comes from the fact that your parents' chromosomes physically separate from one another when gametes are formed), and you may inherit these in any combination of dominant/recessive...	[ "Trauma and fear have been demonstrated to be heritable. That whole archaic nature vs nurture division is looking rather blurry considering this, and epigenetics. _URL_0_" ]
How did Easter, the celebration ending arguably the most sacred time of year for Christians, became, in most places, about bunnies and chocolate eggs?	[ "Springtime is the time for fertility festivals - hence rabbits and eggs. Christianity just liked mapping over pagan stuff with Jesus stuff, but it never quite managed to erase the previous beliefs and traditions." ]	[ "Offense is subjective. It doesn't matter how a concept is given or presented, it's how it is taken. If you can get enough Irish people to protest Notre Dame games, and try to harm their brand by getting people to not give them money, I guarantee they'll change it. If Notre Dame doesn't offend you, or anyone you kn...
A hotel in Hong Kong will be serving wine salvaged from the Titanic wreck. Many questions present themselves.	[ "1) Because water, like many liquids, is very incompressible. Meaning its density changes very little with pressure. At the pressures at the wreck of the titanic, you're only talking about a few percent increase in density (and thus decrease in volume). So even if the pressure difference was maintained (see below),...	[ "Because there are no laws that govern the entirety of the internet. There are laws in countries that limit what the people living inside of its borders can do with the internet, but those laws dont apply if you arent in that country. All pirate bay has to do to stay operational is to find a country that doesn't ca...
Does computer audio have something like a framerate?	[ "Good answers below - you have a latency issue. However, digital audio does have a 'framerate' analogue. It's the rate at which the sound is sampled. MP3s have one of the lowest used in audio at 44.1kHz, so even the slowest is far faster than your 30ms delay." ]	[ "When you watch a video it only needs to send the video as fast as it needs to in order to play it back. When you download a large file from Steam it attempts to get you the file as quickly as possible." ]
How common was a meeting of kings/ commanders before starting a battle to negotiate first?	[ "This kind of meeting is known as a [parley](_URL_0_). The exact interlocking of diplomacy and force is incredibly complicated, but suffice to say wars were most often not started without adequate grievances. There are enough mentions of parleys in literature, including in Shakespeare's play Julius Ceaser, to im...	[ "Unfortunately, AskHistorians only deals with what did happen, not what might have happened and I've therefore had to remove your post. However, your question would be perfect for /r/HistoricalWhatIf, should you wish to cross-post. Thank you." ]
Why are several of the most prized and sought after restaurant ratings in the world done by companies related to the automotive industry? (Michelin, Mobil, AAA Motor Club)	[ "Michelin began as a general travel guide for motorists, intended to help promote the brand new technology of automobiles, and the sale of Michelin tires. It originally also had maps, instructions on how to change tires and hotel listings. Over the years, Michelin began to realize how popular the restaurant secti...	[ "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 do 'jumping jack' construction compactors work? Why don't they seem to jump back up with equal force?	[ "I'm not entirely sure what behaviour you're referring to. Absent any external forces, the overall centre of mass of the machine will stay in the same place. If the footpad is light and the 'motor' part that you hold heavy, that means that the large movement of the footpad will only create a small movement of the m...	[ "This is interesting. Like you when I grew up I found myself easily pushed around and on the weaker side of things. But I already had good grades and always considered jocks to be rather stupid. Once I reached college I realized a few things, grades and intelligence are sort of determined by the individual and the ...
How does my brain decide whether a repetitive song is catchy or annoying?	[ "Those two things are not mutually exclusive - something can be extremely catchy and ALSO very annoying ([example](_URL_0_)). I'm not a music theory expert, but how catchy a song is I think is mostly dependent on simplicity and familiarity - e.g. a simple song is easier to remember and our brain tends to like thing...	[ "I'm not sure there is a system in place - apart from doing your research :). The question is: Is research really redundant? - If more studies give the same results = > Confirmation - If more studies give different results = > Debunked Not to mention that no study uses the exact same premise / method, so while it ...
What is the purpose of pouring Indian chai between containers over and over?	[ "I don't know what the traditional justification is but pouring a liquid between containers does a few things: * Mixes up the contents so the flavors are well distributed * Cools off the contents so they're ready to drink * Aerates the contents so the drink is slightly frothy & creamy" ]	[ "Nobody knows why or even if it works, but that and variations of it are common practise in many countries. Cultural memes are like that, they spread, even if they don't have any real function." ]
Why aren't tattoos applied by a printer like machine? Why do we only have tattoos drawn by hand?	[ "The big problem with using tattoo printers is that skin doesn't act like paper. In addition to being curved, skin has different thickness/resistance at different places. You can't just tell the computer to apply x force for each pixel." ]	[ "Right now it the closest we have gotten is using artificial neural networks. _URL_0_ It isn't quite as complex as mapping all of the synapses in the human brain. Basically we can make a neural network, and by feeding it a set of inputs and the correct output, we can teach it what kind of output we want in the futu...
Theory of Gravity and Laws of Motion question	[ "Ok, looking at the actual video (which doesn't say anything, just a guy saying how great his theory is) I found [this paper](_URL_1_) which claims that electrons are actually rings with a radius of ten picometers. But [experiments](_URL_0_) show that electrons have a radius at most a billion times smaller than tha...	[ "Since momentum is conserved, the bullet can't impart more momentum to its target than it initially has. Since the recoil in a gun isn't enough to throw the shooter back, the bullet doesn't have enough momentum to throw a person forward. Mythbusters did a segment on this, and they showed that before special effects...
When did the first tattoos start to appear in history? Who came up with the idea of putting ink (or other substances) into skin?	[ "There may be earlier examples, but I do know about the Moche Warrior queen, discovered back in 2006. She was a tattooed mummey from Huaca Cao Viejo near Trujillio, Peru. This woman died around 450 AD and had tattoos on her arms. She was also buried with weapons and other artifacts of the type found in other elite ...	[ "...Why do they have default subreddits? Do they ever remove them? What makes a subreddit default-worthy? I'm five years old, please explain... Thanks in advance! Also, before they add a new subreddit to the default list, do they ask the owners' permission first?" ]
Why is it not possible to tickle yourself?	[ "So, if you had a robotic tickling arm that you controlled with a joystick, could you tickle yourself?" ]	[ "In short, Neuroplasticity. Pain and pleasure are both literally \"just in your mind\". By that, I mean that what our minds interpret as pain or pleasure is dictated by the firing of certain neurons in our brains. The pain and pleasure areas lie fairly closely together in the brain. Neurons from one \"area\" can gr...
Why/how do ziplock bags filled with water and pennies repel flies?	[ "Nobody knows why or even if it works, but that and variations of it are common practise in many countries. Cultural memes are like that, they spread, even if they don't have any real function." ]	[ "It's called the Mpemba effect _URL_0_ There's controversy around it because much of the evidence is anecdotal and the effect can't yet be reliably recreated in a controlled lab-setting. However, this anecdotal, non-repeatable evidence has come from enough disparate and respected sources that the Royal Society ha...
What happens in my brain as I study?	[ "This isn't perfectly understood on a cellular level yet. But, the basic idea is that as you learn and study your brain makes new connections between brain cells. The things you know are stored as connections between neurons. The more often you use these connections the more they get reinforced and the more permane...	[ "Usually when we type, we are using our working memory to hold the info we want to type. Our working memory only has so much space in it that if something new pops up it pushes back the old info and takes front seat; attention also affects this. Think of it like a bus. What you're trying to type is in the drivers ...
Both Philadelphia and Boston appear to be much more historically significant than NYC and, in 1776, Philly was the nation's most populated by a significant margin at 40,000 people (NYC at 25,000). What led to NYC becoming America's quintessential city over places like Philly or Boston?	[ "I actually asked this exact question a few years ago. Here were the answers then: [_URL_0_](_URL_0_)" ]	[ "Karachi (largest city in Pakistan) is currently experiencing some large problems; both in crime, and politically. This is in part due to [Altaf Hussain](_URL_0_) who is the founder and leader of the [Muttahida Quami Movement](_URL_1_) - a political party in pakistan based in the city of Karachi. The problems surro...
Monochromatic painting	[ "At least when speaking about art, afaik Monochromatic art is stuff with one color but many hues \$so, say, lighter and darker reds to paint something technically using only the color red, but you can end up making some pretty real looking stuff, it's pretty cool\$. What I think you're actually talking about is ...	[ "They just guess what colors should be there. For example we know what color the grass, sky, or skin color would be. Things such as a shirt, wall paper, or a book would just be our best judgement." ]
how did Chromecast become so huge and popular? It is pretty much the go to standard I see in most apps no matter if it is android or iOS.	[ "It costs 35 dollars and have basically zero setup or learning curve." ]	[ "Ethernet is the most common _wired_ networking technology. When you want to connect one or more computers together as part of a network, you need a router. A router does just what it sounds like -- it _routes_ traffic around a network or between networks (like, say, your home network and the Internet). There a...
In the Early Middle Ages, did European monks ever employ mercenaries to protect them from raiders?	[ "The problem with this question is that what monks did and what they wrote that they did are not exactly similar. We know that monasteries usually relied on the protection of a local lord as well as the inviolate nature of the church. My field is European monastic history and I've never seen any textual mentio...	[ "This is a hold-over from the physical book era. When physical books had to be printed, publishers had local partners in many different places in the world that did local marketing, printing, and distributing to local bookshops. So if you were in New York, you didn't have to talk to a book shop in Switzerland. The...
Where did all the money go during the great depression?	[ "If you have a rock that other people are willing to pay $1000 for (part of a pet rock craze). You have $1000 worth of rock as part of your net worth. One day people are only willing to pay you $5 for that rock (pet rock mania over). Your net worth is decreased by $995, even though nothing physical have changed." ...	[ "Some of it gets auctioned, most it it gets put in storage, a little bit of it gets burned. A small percent the cast and crew (not very likely) get to keep a memento." ]
How do home users use virtual machines	[ "The same way everyone else does. Software testing, running legacy programs that no longer work on modern OS's, encapsulation to help prevent programs from interfering with others, running virtual desktops for thin/zero clients, honeypots to catch hackers, etc. The only difference is that VM's at home are much less...	[ "Your friends are idiots. If you want to buy a house, go for it. If you don't, don't. Renting is not a waste of money if it's what you want." ]
Can someone provide me with an explanation of "Zero Point" energy and if there is any scientific validity to it?	[ "Zero-point energy definitely exists, it's just the minimum amount of energy that a given quantum system can have. But it's impossible to \"harvest\" it, because it's the lowest possible emegy by definition. So yes it exists, but no it's not \"the key to our energy salvation.\"" ]	[ "Some amount of money paid to each citizen no strings, as an alternative to social security. I think the numbers pay out to similar costs. And the benefits are supposed to be substantial. It's already in practice at a small scale in Alaska." ]
Why do fans usually have 5 blades instead of more?	[ "The fewer blades a fan has, the more efficiently it moves air for a given energy expenditure. More blades interfere with each other aerodynamically. However, to get the full effect, those fewer blades have to be longer, which takes up more space. 3-5 blades represent a compromise between space and efficiency." ]	[ "The second two digits refer to the primary interstate that it's an auxiliary of. So auxiliaries of I-15 will be numbered 215, 315, etc. If the first number is even (215, 415, etc.), then it is a loop or bypass: it branches off from the main interstate at one place, and returns to it at a different place. If the fi...
Why aren't bananas juicy like other fruits?	[ "Bell peppers aren't juicy fruits. Bananas are extremely juicy. My grandmother's recipe for old bananas with spots was the best way to get the juice out. 1. Put old bananas into a pot. 2. Pour ONLY 1 tablespoon of water for every banana. 3. Seal the pot with a lid. 4. Alow to cook on 1/4 heat. 5. After 10-15 minute...	[ "1. You've heard their style before, so it's growing stale to you. 2. They used all of their A material when they were younger and trying to break into the scene. 3. As musicians become more popular, they have to give up creative input to please producers." ]
Why does one have to eject a flash drive before removing it to avoid the risk of compromising the data stored on the flash drive?	[ "If you don't have write caching enabled and aren't reading or writing to the flash drive, then there's no need. If you have write caching then you should eject it to be safe. What's write caching? Imagine your flash drive is a truck, and your hard drive is a warehouse. You want to load lots of stuff on the truck b...	[ "Imagine you want to cook some food. You reach for a recipe book. Not being very brave you go for something simple. You take the eggs and mushrooms and butter and ham out of the fridge, and you follow the instructions carefully. At the end of the process you enjoy your omelette and think \"if I ever want this omele...
Why don't we know everything, just by looking at the fundamental laws?	[ "Physicists had the same idea centuries before computers: if we could know the position and velocity of every atom in the universe, then we could know everything about it. Then we discovered quantum mechanics, which tells us that the exact position and velocity (actually, momentum) of a particle at any given time c...	[ "Quantum mechanics will tell you how the position and momentum of a system evolve over time given some external potential, and you can use [Ehrenfest's Theorem](_URL_0_) to relate this to an average force acting on the system, which is the gradient of the potential." ]
Why does fruit oxidize but not humans?	[ "[We do](_URL_0_). You can stop apples from turning brown (oxidizing) by squirting lemon juice on them; it absorbs the oxygen and kind of buffers it from browning the fruit. We have analogs in our cells to block oxidative damage. But it's not a perfect system, and damage does occur." ]	[ "Orange juice you buy at the store is juiced months ago and they let it sit in huge tanks so the flavor is gone. They then add their own special propriety flavor package into it." ]
Every time I purchase something small and say no when asked if I need my receipt, why do tills and pay points print the customers receipt any way, just to be thrown away? could you not tell it to just print the merchant copy by default unless told otherwise?	[ "Some of the new point of sales systems have this option (print, email receipt, or no receipt). But many of the older point of sales systems automatically print the receipt regardless of what the customer wants. The manufacturers certainly can update the software to have this option, but it's not a huge issue for t...	[ "Imagine your hard drive as a giant wall, like the Great Wall of China. Now imagine that your files are painted on this wall (Images, text, music notes). When you delete a file, your computer finds the spot on the wall where that file was painted, and marks that section of the wall as \"free\". It doesn't scrub o...
Why does the skin turn red when it gets hit or when your hand warm up after they have bin cold?	[ "It causes increased blood flow to the area, turning it a deeper, fuller colour. Similar to how your hand becomes red when you swing your arm round really fast, because centrifugal forces pull the blood" ]	[ "Your body can't dissipate heat as well at 75-80 degrees as it might at 50 degrees, so it needs extra help at dissipating the heat. Even though your temperature is 98 degrees you are ALWAYS creating heat and your body is ALWAYS getting rid of heat. So if the environment makes it take longer to get rid of the same a...
How can we measure blood oxygen saturation noninvasively but not blood glucose?	[ "Blood oxygen saturation is very easy to measure. You're looking at two very specific wavelengths of light, which corresponds to the wavelength at which the haemoglobin molecule absorbs light either with or without a bonded oxygen. Compare the two and calculate. Since glucose contains a whole bunch of bonds (C-O,...	[ "Nothing special about \"yogis\" doing this, if they are doing it. Nothing mystical about it. Nothing about chakras, meridians, rooting, or any of that other BS. [Here's an article you can read online](_URL_0_) Learn biofeedback. There are tons of research articles on the voluntary control of brain waves, heart rat...
why does the size of the flame on a gas stove change the cooking temp? Isn't the flame the same temperature no matter now large it is?	[ "A larger flame is the result of more gas being burned. More flame means more heat overall, even though each part of the flame is the same temperature. Think about it. What is more heat, a postage stamp at 400 degrees or a football field at 400 degrees?" ]	[ "When you take a pill it's not 100% the labeled medication. There are other ingredients that help it do its job and release when and how it is supposed to. Sometimes a medicine needs more extra ingredients to do its job so you end up with a bigger pill." ]
Sorry if Repost. When you donate money to a charity (Susan G. Kolman, March of Dimes etc) where does the money go that isn't used for overhead? Couldn't we just donate to the place they do?	[ "A lot of medical-based charities give grants to research labs for specific research projects. Hypothetically you could make a donation to a specific university's lab, but there is a good deal more that goes into it than just receiving money. The labs have to fill out applications for grants and prove to their dono...	[ "When you suck on a straw, it isn't the suction pulling the milk shake up. It's the weight of the column of air above the milkshake, extending into space pushing down on top of the milk shake as air pressure. All you did by sucking was remove the weight of air on top of the milkshake straw that was holding it down....
Mass of food v/s calories	[ "The mass of the food is irrelevant to weight gain. A kg of watermelon has 300 calories, about the same as 45 grams of butter. You'd get the same weight gain either way -- but pee more after the watermelon." ]	[ "Surface area difference of food to taste buds/nasal passages. Sipping a drink versus chugging a drink makes for very different tasting experiences." ]
What is actually going on with Russia?	[ "Russia sees the West as this big monolithic thing which is moving eastward, swallowing up countries, and moving forever closer to Russia itself. Since the fall of the Iron Curtain, numerous former Soviet countries have joined NATO and the European Union, causing Russia to see these organizations as expansionist th...	[ "This CGP Grey video does a really good job of explaining it all. _URL_3_" ]
Why don't americans vote absentee?	[ "Different states have different laws about absentee ballots. Each is fairly unique. In some states, such as California, 20-30% of all votes are absentee ballots. In Washington and Oregon, all votes are by mail. There are 50 states plus DC and the territories, and they all have different rules. Edit:spelling" ]	[ "\"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..." ]
Aside from public image, why do companies that most consumers can't specifically buy or use (like Boeing and CSX) put commercials on TV?	[ "Investors like to see their investment have a presence. This is one way to show they're active. Endorsing charity walks is another." ]	[ "Data. Pure, gooey, delicious data. Seriously though - the Airlines are collecting data on a massive scale. If they notice an uptick in travel to/from one city they will use that information to update how their resources are distributed." ]
In Total War: Rome II, troops are able to burn down city gates by throwing flaming torches at the gate. Was this ever a viable tactic? Are there any examples of this method being used historically?	[ "Throwing torches at an object either made of incredibly hard wood or even metal will not make it burn. I realise that there are apologists on the TW subreddit who will defend anything coming out of CA but this is simply impossible. I realise that the absence of evidence doesn't constitute evidence of absence but i...	[ "There are are variety of different cooking methods we know of from prehistory. Spitted meat seems broadly common, in British Isles and Scandinavia there's evidence of heated stones and water pits being used to cook as well as spitted meat (Keating 1908:326), in Polynesia and other places there's evidence of essent...
What exactly is 'stretching' and why is it important that we do it before exercise?	[ "First off [stretching is bad](_URL_0_), it increases the chances of injury, and decreases the max force you can exert. Secondly it is where you extend you limbs in such a way as to [\"pull\"](_URL_1_) the muscles along their length, to make them more limber. EDIT: oops, I should have clarified, stretching is *onl...	[ "The disk is basically a bunch of empty blocks all in a row. When you get some data on your computer, these blocks fill up. Every file is made up of a bunch of blocks (the blocks are really small). When you delete a file from the middle of the stack, that bunch of blocks become empty. You computer doesn't want to w...
How do frogs, toads and other amphibians know how and where to find new bodies of water?	[ "Amphibians explore and migrate during cool moist weather. They can cover a lot of distance that way, especially if they can find damp places to take shelter in between stages of their journey. Most animals (including us) are also perfectly capable of smelling water from a good distance. Wind blowing across a body ...	[ "A lot of it would be smell and pheromones wouldn't it? That's why male dogs go nuts when female dogs are in heat - they can smell the pheromones they're giving off (from some distance away I might add)." ]
What's the difference between regular batteries and rechargeable batteries?	[ "Both batteries produce energy through an electrochemical reaction that involves an anode, cathode, and electrolyte. When the battery is discharging energy, the anode is the negative terminal and the cathode is the positive terminal. These two components, referred to as electrodes, occupy the most space in a batter...	[ "A variety of reasons. Disciplined troops fought in rank and file for literally thousands of years. It made them easier for generals to control, improved morale, and formations like the phalanx were stronger than the same number of men acting as individuals, particularly against cavalry. The same rules applied with...
What is double clutching? How and why do you do it when shifting?	[ "Well, the alternative is granny shifting which, of course, will cost you the race against Toretto. Nobody wants that - but who can really blame you? He's the best there is." ]	[ "Can't speak for the rest of Europe but one reason in the UK might be that to get a full licence in the UK you have to take the test using a manual car. You can take the test using an automatic car, but the licence you get then prohibits you from driving a manual car. If you pass in a manual you can drive both auto...
How did the Asian slanted eye trait develop as a hereditary feature?	[ "It is called an epicanthic fold. We actually aren't certain yet why they evolved. One theory is that they help protect the eye in environments where the sun reflects more intensely off the natural environment such as snowy regions and deserts." ]	[ "All of those places have had a different history since the last glacial maximum. For one, The Japanese archipelago [wasn't so much a archipelago](_URL_0_). And Australia also wasn't just the island that it is today. In the distant past they had multiple populations and some people moved in and off. Taiwan being th...
If you were to put a person in a tub of room temperature water, and raised it a few degrees at a time, could you kill them without discomfort?	[ "What comes to mind is the boiled frog experiment. The basic \"idea\" behind it is that if you put a frog in a pot of water and slowly raise the temperature, it'll die before jumping out. This is a widespread myth but it's untrue. It's likely based on experiments done in the mid 1800's, where scientists found out t...	[ "The equation you posted is about the thermal energy change. (dT is temperature not time). The object in the freezer will cool faster because it has more convective heat transfer, temperature change due to a difference with the surrounding air. See [here](_URL_0_). You want to look at Q^dot not Q. Q^dot is the rate...
Why do motorcycles produce more pollution than cars despite having better gas mileage?	[ "One means of fuel efficiency and it answers you second question is the power to weight ratio. Motorcycles have much more power compared to weight than a car. As the weight increases, more power is required to maintain a given speed which consumes more gas. There are many other efficiencies gained with smaller engi...	[ "You're overthinking it. [Here](_URL_0_) is a scientific article about it, but it's still kind of complicated. The easiest way to think about this is the 10:1 rule. For every one pound of meat you, need ten pounds of feed for it. This means that if you ate the feed directly (eg, corn), you would use only 1/10 of...
What is the Illuminati and what is the big deal surrounding them?	[ "The Illuminati, contrary to the current top comment, are not a fictional group of people. Whether they still exist today is debatable, but they were at one point a very real, and semi-secretive group of men (lead by Adam Weishaupt) who formed an order of sorts with the stated intent of bringing \"Illumination\" to...	[ "internet locations that aren't accessed or indexed by search engines like google. it's like an elite nightclub: you only can find it if you already know where to go, you won't ever \"stumble\" upon it." ]
How does someone who has had an arm or a leg removed have it reattached and made able to work again?	[ "It's a painstaking process that involves suturing together muscles, blood vessels and nerves. They literally have to go suture together even the tiny arteries in a limb. You might wonder, well, what about nerves? Those don't grow back, right? Well, it turns out that some kinds of nerves actually can heal themselve...	[ "[Heart-Lung machines](_URL_0_) exist and are used during some surgeries. And scientists are getting close to creating an artificial lung that can be transplanted into patient's body." ]
How does placing a wooden spoon over a pot of water prevent it boiling over?	[ "A dry wooden spoon is somewhat hydrophobic so it can pop the bubbles just like your finger can. As the wood gets wet, that doesn't work as well. But a cool wooden spoon can still cause the steam in the bubble to condense and destabilize the bubble. Eventually the spoon heats up and that doesn't work either." ]	[ "While common sense says \"No\", newton's third law and all that, Mythbusters have actually proven that it DOES work due to some clever physics. Its similar to how old ships used to sail against the wind and all that." ]
Why does paper beat rock?	[ "Paper beating rock dates back to ancient Chinese culture. When a petition was made to the Emperor, the petition was signified by a rock. Upon making a decision the Emperor would have his servants place a sheaf of paper either over or under the rock. If the sheaf was placed under the rock it would signify acceptanc...	[ "This is a very common question. You can use search to find [all the other really good answers](_URL_0_ ). This is instant, and faster than ust typing in your question every time. It's a way of cheating elections. Read the others, and then ask a more specific question." ]
Why did Wagner rename Sigurd to Siegfried for his Ring Cycle?	[ "\"Siegfried\" actually dates back to the 13th century [Nibelungenlied](_URL_0_). That's still younger than the Norse sagas, but can't be attributed to Wagner." ]	[ "Apparently your Google/Wiki search talents are awful. [Archibald Armstrong](_URL_2_) [William Sommers](_URL_1_) [Robert Armin](_URL_0_)" ]
Why is immigration such a hot button topic in UK politics at the moment? What effects are immigration having on the economy right now?	[ "Mostly, it's a non-issue. However, trying to remove freedom of movement is an effective way for parties to appeal to their more authoritarian supporters." ]	[ "Viruses and bacteria have been around a long time. Viruses are not quite organisms. The need to hijack the DNA or RNA transcription machinery of a living cell to reproduce. They mutate easily. Some are able to reproduce in hosts of more than one species. The damage they cause if any is species-dependent. Ebola vir...
Is the Dominican Republic's name related to the Dominican Order?	[ "No, it's related to domingo, which means Sunday in Spanish, because it was discovered on Sunday. Compare Dominica, another independent country." ]	[ "Former telemarketer here, 1. When you register on the DNC List it is only active for a certain amount of time. After about a year you need to renew yourself on whatever website you used to register. 1. Tell the telemarketer that you are on the DNC List. They may be working with older information, and will have...
what do movie directors actually do?	[ "Being someone who writes scripts and loves film, directors are interpreters. I picture it as a story you've heard a thousand times. i.e. Goldilocks and the three bears. Everyone knows the story, but they imagine the story playing out in their heads; such as what the characters look like, sound like, and how the p...	[ "MPAA send a request to google to stop showing results for a specific subreddit, /r/FullLengthFilms, because in it they found links to cam recordings of Tom Cruise's newest film 'Edge of Tomorrow'. That subreddit had like, 300 subscribers prior to this but this move made a huge number of people visit it." ]
why countries like Canada have different processing times for different countries of same type of applications?	[ "[From the bottom of that article:](_URL_0_) Why are there differences in processing times among regions and offices? Visa offices face different challenges operating in different countries and regions, and even in different offices within the same region. Various factors can affect the time it takes to process...	[ "The change came with the meeting between Nixon and Mao. Reading up on that meeting might be a place to start. The relationship between China (PRC) and Taiwan (ROC) is interesting. Both governments consider them to be one country. As long as the exiled-government-of-China-which-resides-in-Taiwan continued (and cont...
What percentage of the US South supported slavery during the late antebellum period?	[ "I can't speak to how many supported it morally or ideologically, although I would feel safe in venturing that it was a vast majority. I can tell you that about [1/3 of all households in the south held slaves in 1860.](_URL_1_) (data is from [1860 census](_URL_0_))" ]	[ "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_) ]" ]
When did the "sue happy culture" happen?	[ "I can speak for the UK, I think. Here, it was illegal for law firms to offer 'No Win No Fee' claims for civil cases until 1995. This meant that for you to sue someone you had to have the money to pay for a costly lawsuit with no guarantee you'd win. Most people wouldn't take the risk. When 'No Win No Fee' was perm...	[ "I know I've quoted this before here, but... > Everything is at its Acme; especially the art of making one's way in the world. There is more required nowadays to make a single wise man than formerly to make Seven Sages, and more is needed nowadays to deal with a single person than was required with a whole peo...
Do particles still exist as "probability distributions/wave functions" when part of a solid?	[ "Yes, particles are still waves/particle distributions inside of solids, which is actually what leads to bonding and the solid phase in the first place. What happens is when you bring a bunch of atoms close together, the electron configuration with the lowest energy is not for all of the electrons to be localized t...	[ "The weird taffy looking object that can be rendered as if it were a real 3D object that you see depicted as a Quaternion fractal isn't actually the fractal itself. It is a 3D \"slice\" of an undepictable 4D Julia Set. If you slice a 3D sphere the cut face is a 2D circular thing. If you slice a 3D cube parallel to ...
Why do different types of alcohol make me different types of drunk?	[ "There is currently [no pharmacological evidence](_URL_0_) to say that this actually happens. This is not to say that you're completely wrong; indeed, many people have this experience. But it is believed to be the context and amount of the drink which affects you, not the type of drink itself. E.g.: Since whisk...	[ "Neural adaption. Basically, your brain only cares about a change in stimuli rather than every stimulus that comes along. Your brain knows how to ignore a stimulus if it isn't changing. So, if you are tasting/feeling the same thing all the time, your brain is going to ignore it." ]
Why do humans have eyebrows although we have lost most of our body hair?	[ "I don't know how effective eyebrows are at preventing sweat from entering the eye, but eyebrows have a conserved function in many primates; non-verbal communication. The use of eyebrow signalling has been recorded in most [human cultures](_URL_0_). Without uttering a word, we can express a friendly greeting, surpr...	[ "There's the basic evolutionary stuff we're all born with that dictate who's \"beautiful\" based on preferred biological mating characteristics. A woman with good size breasts and hips is considered better from a biological stand point for procreation. Her breasts show she can provide for a baby while her hips show...
why is Drometrizole trisiloxane used in some sunscreens to absorb UV radiation?	[ "No, sunscreen works by absorbing UV light, not by reflecting it. As you can see in [this video](_URL_0_) using an ultraviolet camera. Turns out this is very efficient." ]	[ "Extrasolar planets are small and dim and really far away and their light is swamped by the light from their nearby stars. Existing telescopes for the most part don't even have the ability to distinguish the light from a planet direcdtly as a dot, much less map the planet. There is a proposal to devise a system to ...
How does a gas fridge keep things cold by making heat?	[ "Gas-powered refrigerators are [absorption refrigerators](_URL_0_), which as actually an older design than the compression refrigerators powered by electricity which we're used to. The single-pressure variant uses three different refrigerants (water, ammonia, and hydrogen) and depends on somewhat complex changes of...	[ "Special relativity tells us that the mass of an object is simply its energy divided by the speed of light squared (m = E/c^2 ). That energy includes all kinds of energy, even thermal energy. The colder an object is, the less thermal energy it has, and the less mass it has. So yes, the object gets lighter as you c...
Can a mosquito give you AIDS?	[ "No, only saliva is injected into humans by mosquitos so the hiv positive blood would never make contact with you, also hiv can't replicate outside of the human body so its broken down in the mosquitos digestive system." ]	[ "Because everytime he claps his hands, a child in Africa dies." ]
do any other countries have military bases around the world, as the United States does?	[ "yea. a couple. French, Russia, UK, India _URL_0_" ]	[ "Let's say you're starting a business and I loan you the money to get started. You make your payments and manage to keep the lights on. Soon, you start making a profit. I, who loaned you money, don't come demanding more money because you're making the payments on which we agreed. Your buddy Jeff has a business, to...
What measures were taken to prevent President Reagan from divulging state secrets due to his Alzheimer's disease?	[ "Federal records archivist here. We can't know the answer to that for sure, we aren't privy to details of Reagan's medical privacy. Most classified topics concern technical details of aircraft and weapon design, or other things that would hardly ever come up in conversation unless you were at work. It's unlikely th...	[ "> what where they told in regards to ailed advances, Depends. There were many instances of the Nazi regime lying about defeats, or the actual extent of the disasters...but the public was generally aware the war was going badly after 1942. > and what where they told to expect once Berlin fell? The people knew tha...
why does the earth still have such a big molten core after so long?	[ "The inner core is solid because of extreme pressures. The outer core is molten because of the extremely high temperatures. It's not a star although radioactive elements have kept the interior hot. Initially it was hot because of the energy coming from rocks coalescing together. You have those two sources of heat (...	[ "Go light a bucket of gasoline on fire, it'll take a few minute to burn depending on the depth/width and whatnot. Now imagine something hundreds of billions of times larger." ]
Why is it that meteorologists can predict the weather for days in advance fairly accurately, but can't tell if a tornado might be coming till the last few hours?	[ "Let's say you want to travel to Chicago from Atlanta by car. Can you predict your exact position at any given time? No. You can predict where you are going to be in the next few seconds but as you look further ahead you lose accuracy. Sure, you could say, \"I'll be near Indy around 6pm on this road, but you don't ...	[ "The IRS doesn't know exactly how much money you will make this year based on a single paycheck, you might have a second job or a rental property or you might get a raise. They also don't know what deductions you qualify for or are going to take when they issue your pay cheque." ]
How do companies like GE pay so little in taxes?	[ "Explaining all aspects would take a very long time. Basically though, GE own many companies, some of which lose money and some of which are deliberately allowed to lose a ton of money. When you factor in all of GE's holdings, you can get to that effective tax rate." ]	[ "They're quoting you the \"I have servers and need high reliability\" level of service, not the \"I need to browse the internet\" level of service. If you want to run a server farm with gigabit speed, you're asking for upload speeds of a gigabit, with low latency and high accessibility. You may need to talk to ...
Is it a lucky coincidence that the equation for displacement in kinematic motion is a simple parabola?	[ "It's only that simple when acceleration is constant. Under that assumption, your question really boils down to \"why is the integral of x^n proportional to x^(n+1)?\" (I'm going to assume that, as an engineering major, you at least know basic calculus.) If your position (or displacement) is a function of time, x(t...	[ "You can't just \"swing by\" any planet you want to use as a slingshot, the planet must be in a very specific place at a specific time. Launches are typically organised to fall in places where this is possible, but it isn't always and the trajectory New Horizons is using is probably the best one they can get for a ...
Is there a way to convert ambient heat into electricity?	[ "To be able to extract any energy, you have to have a differential -- somewhere cooler to dump the heat. Heat will naturally move from hotter areas to colder areas. You can sometimes place a machine (such as a Stirling engine) between the hot and cold areas and extract a bit of energy from that flow, but efficiency...	[ "That's like trying to harness the power of a mach-5 railgun slug with a windmill. The powers involved are incredibly forceful, incredibly brief and pretty unpredictable. The device would have to be extremely robust to withstand such forces, cheap enough to be deployed en masse to take advantage of infrequent thund...
Are humans considered tetraploid (4n) during anaphase and telophase?	[ "The -ploidy classification for a cell would be for its normal state. Humans have a variety of cells that operate in different states of polyploidy. Most human cells are diploid, gametes are haploid, some liver, heart, and bone cells are polyploidic. Humans are considered to be diploids, because that is what most o...	[ "While not a scientific answer to your question at all, I want to suggest the excellent movie [Before the Fall](_URL_5_) (German Titel: Napola – Elite für den Führer) to anyone interested in this topic, which is a story about pupils in an elite high school in the German Reich." ]
Linear Alegbra: What the difference between Linear Independence and Linear Dependence is.	[ "Let's say I give you a set of vectors. If any one of those vectors can be constructed as a combination of any of the others, then the set is said to be \"linearly dependent\". If the set isn't linearly dependent, we call it \"linearly independent\". One way to check for linear independence is to write down a matri...	[ "Have you checked [Wikipedia's article on line integrals](_URL_0_)? There are two animations over there (both created by me, actually - [my Wikipedia gallery](_URL_2_)) explaining the line integral [on a scalar field](_URL_1_) and [on a vector field](_URL_3_). Click on those links to go to each image's description ...
How Anti-Semitic was Fascist Italy?	[ "The Jews living in German-occupied parts of Yugoslavia often tried to flee into the Italian occupation zones, as Jewish people were better treated there, even if interned in camps. And Jews already there made numerous attempts to extract their friends and relatives and bring them to Dalmatia. However, Croatian Ust...	[ "The LA Times had an article that told the story of a modern family in New Mexico that had the curious tradition of lighting candles on Friday nights. The article went on to describe how they eventually discovered their Jewish heritage going back to the conquistadors. See _URL_0_" ]
How to skateboarders keep the board "stuck" to their feet when doing tricks?	[ "Friction from the grip tape with fore/aft motion and the board falling slower than your feet are moving down or rising faster than your feet are moving up." ]	[ "Those object are experiencing the same gravity. If the space station vanished, aside from killing every one, all the objects would continue to orbit the earth in the exact same trajectory. It's simply that the ISS and its associated people and objects are falling together. Think of an airplane suddenly losing all ...
Why was gold used to stop contamination in the past?	[ "Certain metals demonstrate something called the oligodynamic effect. Not only gold has this; a bunch of other metals like silver, copper, tin, etc. all demonstrate this effect. (there's a list here: _URL_0_) In short, the oligodynamic effect is when the metal atoms are capable of attaching to certain proteins and ...	[ "You could test it. E.g. cover yourself in grease and then shower 1) with water only 2) with water and the product. Compare results. That would be a (pretty crude) experiment, which is how we learn answers to those kinds of questions. Also you could compare two pieces of perishable food, one of them treated with th...
Why does anybody choose a petrol (gasoline) car over a diesel car?	[ "Diesel has only recently been cheaper, historically, it's usually around the price of Premium Unleaded, so most people who don't get sporty/luxury cars (which take Premium Unleaded) don't want diesel because most think short term and think they are saving money, as Diesel engines cost more upfront as well." ]	[ "The US is much more spread out than Europe. Taking a train from Portland to San Francisco is a 12-16 hour journey. Since taking a plane is about the same price & only takes an hour, it's much more popular. Rail is popular in places where you have a bunch of cities close to each other (Portland/Seattle, Boston/New ...
How does modern mid priced wine compare to the wine drunk by ancient kings and caesars?	[ "Ancient wine is apparently pretty unpalatable by modern standards. I can't imagine drinking wine with resin, marble dust or burnt grape seeds or other ingredients that were meant to keep wine from spoiling. Nor can I see seawater as a pleasant mixer. Now as for them who could say. My grandad drank stuff that taste...	[ "I've deleted this post. \"Throughout history\" questions, as stated in our rules, [are too broad for this subreddit](/r/AskHistorians/wiki/rules#wiki_no_.22in_your_era.22_or_.22throughout_history.22_questions). Moreover you're obviously trying to make a point about the way this subreddit is run which makes me doub...
Can someone explain to me what these ants and mites are doing?	[ "I'm pretty sure those are aphids. Some ants (at least one species) harvest aphids in 'farms'. They protect the aphids, and use the \"poop\" of the aphids as a source of food. It's a pretty cool symbiotic relationship. [source with more information](_URL_0_) EDIT: Oh dang, got beaten to it by molisan. Same source a...	[ "By tapping the wood. You quite clearly hear the difference when they find a good spot vs when they find nothing. And if they find nothing they just try another spot." ]
I've always heard that you heal faster when you're asleep, is anything actually chemically happening differently while we're asleep that helps us heal faster? Is this just not true at all?	[ "It's not that healing happens faster at night, but it happens in a more efficient manner. Your body does a full maintenance at night repairing many tissues, regulating hormones, as well as the immune system gaining strength during sleeping hours. There have been [studies](_URL_0_) linking decreased sleep to decrea...	[ "Your skin is constantly shedding then regenerating itself. Cells divide in the basal layer of the epidermis, and the new cells are pushed up towards the surface of the skin, going through various changes as they do so including losing their nucelus, and when they reach the surface the are mostly just keratin and a...
Why can some people move each eyebrow independently and others can't?	[ "Some people are born with the muscle for that eyebrow developed, and some aren't. You can actually train your non moving eyebrow to move. I did it myself!" ]	[ "You can learn it quite easily by following some of the tutorials on YouTube - I learned to do it without references in a couple of hours. It takes NO skill to just solve it - doing it really fast though, is something else." ]
What's the deal with renewable energy?	[ "If by \"sudden\" you mean \"long-standing\" and by \"past several months\" you mean \"past several decades\", then you are absolutely right. You're basically seeing a few big news stories breaking around the same time and equating it to something that's \"just happened\". People have been fighting for renewable ...	[ "Remembering to recharge batteries is inconvenient. Rechargeable tend to lose power over time if the charge isn't topped up. Lots of people have had bad experiences with older (Ni-Cad) batteries and don't even want to waste time with them. Disposable batteries are still dirt cheap." ]
If F=M*A then how come when I turn on a flashlight or laser it doesn't shoot out of my hand?	[ "1. Photons have no mass. 2. Photons don't accelerate to the speed of light. Rather, they travel at the speed of light the moment they begin to exist. That said, photons do have momentum. It's just very, very small." ]	[ "The easiest way to answer your question is to buy a double hook scale like [THIS](_URL_0_) ($20) and tow the truck with it. Do the same with various masses on the sled and you will have your answer. The amount of force to get the sled moving will probably be higher than to get the truck moving because it will lik...
What actually happens when you microwave metal?	[ "The metal acts as an antenna. The powerful electromagnetic field in the microwave induces an electric potential in the metal, which may be sufficient, depending on the geometry of the metal (points arc much more easily, and thin films are also vulnerable) and other factors, to induce arcing (when a sufficiently hi...	[ "Space blanket's work by providing a reflective surface. A fair amount of heat that escapes ones body is due to radiative processes (as opposed to conduction [touching], or convection [breeze]). By wrapping you in the mylar blanket, any heat that is radiated from your body just bounces back! In the meantime, it als...
The national do not call list	[ "I think the do not call list has just put a complete end to legitimate sales callers. I know I'm on it and I haven't received a legitimate sales call that violates the do not call list in a long time. What has happened is the price of robocalling has dropped, and they have started using stuff to mask their true id...	[ "Pretty sure we all collectively agreed as a species in 2012 to just keep our phones on vibrate." ]
How do movies like Avatar look so crisp and detailed in full-frame or IMAX despite the fact that they were shot with 2.2 megapixel cameras?	[ "I think you mean most movies, only like 1/4 are 4K today. 99% of tv is either 720p or 1080i as well. > Keep in mind, this was a 300m dollar production by James Cameron, known for using the most high-end gear to achieve the best images, so this was a conscious choice. 4K movies didn't exist until 2011, so it w...	[ "I don't know any specifics here, but when using a fiber bundle as a simple optical path (rather than transferring digital data), you get one pixel per fiber. I highly doubt 20 MP is possible at a practical diameter. More importantly, though, a fiber bundle is not a lens; it doesn't focus light, it just transmits i...

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