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choice theory	Hi, which choice theory are you referring to? There's a few out there. Personally I study criminology, meaning the Rational Choice Theory is by far the most well known, so I'll explain that one: The rational choice theory explains us how people choose to do things or take actions that might go against the social norm...	[ "Decision theory (or the theory of choice not to be confused with choice theory) is the study of an agent's choices. Decision theory can be broken into two branches: normative decision theory, which analyzes the outcomes of decisions or determines the optimal decisions given constraints and assumptions, and descrip...
why hasn't there been prosecution for the corruption on wall street?	First, because Wall Street has a shitload of money, which buys them political clout. Second, because taxpayers got nearly all of the bailout money back.	[ "When large firms such as Enron, WorldCom and Global Crossing were found guilty of fraud, Wall Street was often blamed, even though these firms had headquarters around the nation and not in Wall Street. Many complained that the resulting Sarbanes-Oxley legislation dampened the business climate with regulations that...
if for all of pre-human history and most of human history we were scavengers that relied on fruits and nuts, how are there so many humans today that have nut allergies?	This is a pretty interesting concept! Hunters/gatherers had to subside off of the land and with what they had. As of such, individuals with potentially fatal reactions to things like nuts seemingly would have been weeded out of the gene pool. One of the main theories behind the concept as to why there are so many peop...	[ "During the 1970s, Lewis Binford suggested that early humans obtained food via scavenging, not hunting. Early humans in the Lower Paleolithic lived in forests and woodlands, which allowed them to collect seafood, eggs, nuts, and fruits besides scavenging. Rather than killing large animals for meat, according to thi...
what is an apr?	APR is annual percentage rate, or otherwise, simple interest. For example, if you have a $10 loan for the year with 50% APR, that is 50% of $10 = $5. So you owe both the principal amount ($10) plus interest ($5) = $15.	[ "APR is dependent on the time period for which the loan is calculated. That is, the APR for a 30-year loan cannot be compared to the APR for a 20-year loan. APR \"can\" be used to show the relative impact of different payment schedules (such as balloon payments or biweekly payments instead of straight monthly payme...
The validity of Hong Xiuquan's visions?- Taiping Rebellion	EDIT: For an answer to the main question, please see [my subsequent Saturday Showcase post.](_URL_0_) The answer to your main question is something that will require me to do a little digging into source material that I can't access till I get back from holiday tomorrow, but on the matter of the Triads, what is import...	[ "Du Wenxiu, who led the Panthay Rebellion, was in contact with the Taiping Heavenly Kingdom. He was not aiming his rebellion at Han Chinese, but was anti-Qing and wanted to destroy the Qing government. Du's forces led multiple non-Muslim forces, including Han Chinese, Li, Bai, and Hani peoples. They were assisted b...
What was the 1993 Russian constitutional crisis ?	"Post Soviet Russia" by Roy Medvedev contains a day-by-day breakdown of the events. The crisis was that the congress ruled to impeach Yeltsin after Yeltsin attempted to introduce rule by decree. Now Yeltsin attempted to dissolve the congress which was something he explicitly wasn't entitled to by the Russian constit...	[ "BULLET::::- The constitutional crisis of 1993: a conflict between Russian President Boris Yeltsin and the Russian parliament led by Ruslan Khasbulatov. It emerged due to disagreements regarding the demarcation of political authority. Russian leaders agreed to hold a referendum in April 1993 that would determine wh...
In England 1700s(?) How did the trend of caked face paint, absurdly large dresses and wigs come about?	You may be interested in [a recent answer of mine](_URL_1_) that begins to answer a little part of this question. To crib from the end of it, > One thing is that hooped petticoats have a long history in western fashion, and the more extreme versions developed out of ones that looked roughly like someone wearing many ...	[ "Among women in the French court of Versailles in the mid-to-late 18th century, large, elaborate and often themed wigs (such as the stereotypical \"boat poufs\") were in vogue for women. These combed-up hair extensions were often very heavy, weighted down with pomades, powders, and other ornamentation. In the late ...
Trig Expression Confusion	You have a right triangle. You know the hypotenuse and one angle. How do you find the lengths of the two legs? Using the rules for cosine and sine: cos(θ) = (adjacent length) / (hypotenuse length) sin(θ) = (opposite length) / (hypotenuse length) So if you want to find the length of the side adjacent to your angle, y...	[ "A possible explanation for lag-1 sparing is that this phenomenon is heavily interconnected with attentional blink, but does not operate on the same cognitive mechanisms and requires different stimuli to occur. Specifically, for lag-1 sparing to occur, it needs visual input as practice targets. These targets can be...
why was nafta so supported in the beginning but ended up failing as a policy	What do you mean by "failed"? The goal was to increase trade among Mexico, the US and Canada and it has succeeded in those goals.	[ "When NAFTA was being developed to include Mexico, the developers of the deal presented it as way to create more middle class jobs in Mexico by increasing development and investment in Mexico. This deal followed a trend of increased neo-liberal policies in Mexico that ultimately made the implementation of NAFTA pos...
if the goal of an experiment is to be unbiased, why even form a hypothesis in certain studies?	To construct an experiment, you have to ask a question that needs to be answered. And often that question takes the form of a hypothesis that needs to be either confirmed or refuted. The hypothesis is the question you want to ask the universe. But the universe has a habit of being kind of secretive and not very obvio...	[ "This is an investigation of whether the real world behaves as predicted by the hypothesis. Scientists (and other people) test hypotheses by conducting experiments. The purpose of an experiment is to determine whether observations of the real world agree with or conflict with the predictions derived from a hypothes...
why can't we generate electricity by positioning magnets around turbines?	That is how we generate electricity. Use something to spin a turbine, use the turbine output to spin some magnets.	[ "A useful technique to connect a permanent magnet synchronous generator to the grid is by using a back-to-back converter. Also, we can have control schemes so as to achieve unity power factor in the connection to the grid. In that way the wind turbine will not consume reactive power, which is the most common proble...
how do zipline and cablecar wires get laid out long distances?	If you can get one line across the gap, you can use that to pull across larger and larger lines until you have the final cable in place. In the case of cable cars, it's simpler because it has pylons with known distances between them, and there are different ways to do it e.g. use a crane or a helicopter to lift the e...	[ "Professional versions of zip-lines used as an outdoor adventure activity are usually operated at high speeds, covering long distances and sometimes at considerable heights. Cables can be very high, starting at a height of over , and traveling well over . Riders are physically attached to the cable by a harness tha...
why can a company ship me a package from sweden to us for free, but if i try to ship it back to their address it costs me $100?	Nothing is "free". The cost is covered by you. You've paid shipping, it's simply buried in the cost of the goods you purchased.	[ "Users can sell clothing, shoes and handbags in two ways: request a prepaid selling kit or print out a shipping label. Twice processes the items and sends an all-or-nothing offer to the user within days, which users accept or reject. If accepted, Twice offers multiple options for immediate payout including PayPal a...
why can't task manager instantly stop a process?	It's always best if you can give tasks a chance to quit nicely. A task might be in the middle of writing data to disk, for example. If you can give a task a bit of warning that it's being killed, the task might have the chance to finish what it's doing and exit gracefully without losing data. Sometimes that doesn't wo...	[ "Tasks waiting on user input or file reads would not normally be listed as waiting entries for operator attention. Another reason for a task to be waiting is waiting on a file. When a process opens a file, and the file is not present, the task is placed in the waiting entries, noting that it is waiting on a certain...
how bedsores develop	They typically occur on areas where soft tissue lie over bones. When the person is immobile, the prolonged pressure between the chair and the bone causes the blood flow in the soft tissue to be decreased which leads to tissue death (necrosis). Also if there is a pull/shearing force on the soft tissue, that can break th...	[ "Sexual reproduction is more rarely reported and occurs when two adjacent sporangia function as gametangia with one transferring all of its cytoplasmic contents into the other, resulting in the development of a thick-walled, lipid-laden resting spore.\n", "Sexual reproduction results in the formation of a zygospo...
Is it possible to run out of tunes in music at some point?	There are really only a limited number of progressions that make any "sense" to us musically, like a V-I cadence [you'd know it when you hear it...] or open ones like I-V or I-IV ... Things like [say] V-ii-I might sound nice [depending on the key and melody] but wouldn't function as say the end of a piece. In this wa...	[ "Tunes are typically binary in form, divided into two (or sometimes more) parts, each with four to eight bars. The parts are referred to as the A-part, B-part, and so on. Each part is played twice, and the entire tune is played three times; AABB, AABB, AABB. Many tunes have similar ending phrases for both A and B p...
elon musk's 'master plans'	As a company that have a goal to eliminate our demands for fossil fuel it opens them up for critique when they are doing things that seams contradictory to their primary goal. For instance Tesla started making race cars and then luxury sedans, neither are known for being eco-friendly, and thus providing a means to incr...	[ "Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future is Ashlee Vance's biography of Elon Musk, published in 2015. The book traces Elon Musk's life from his childhood up to the time he spent at Zip2 and PayPal, and then onto SpaceX, Tesla, and SolarCity. In the book, Vance managed to get regular interview...
if you get a blood transfusion and your blood is found at the scene of a crime and tested, how does it effect the results?	As others have said, red blood cells have no DNA. Rather, it's other cells, such as white blood cells, that are present in blood and are the source of DNA evidence in "blood". What you may not know is that when you donate blood (or receive donated blood), that blood is filtered and separated into its constituent comp...	[ "Drug-testing a blood sample measures whether or not a drug or a metabolite is in the body at a particular time. These types of tests are considered to be the most accurate way of telling if a person is intoxicated. Blood drug tests are not used very often because they need specialized equipment and medically train...
what happens when you raise a number to the power of i (the imaginary number)?	I thought this was explain it like I'm 5, not explain it like I'm in my fifth year of graduate school...	[ "In mathematics, a power of 10 is any of the integer powers of the number ten; in other words, ten multiplied by itself a certain number of times (when the power is a positive integer). By definition, the number one is a power (the zeroth power) of ten. The first few non-negative powers of ten are:\n", "When a nu...
why is it okay for actors to impersonate police officers when filming in public locations? are there special laws that govern filming?	Laws vary by jurisdiction. However, laws against impersonating a public official will usually have language like the following, which prohibits impersonating a public official: > ...with purpose to induce another to submit to such pretended official authority or otherwise to act in reliance upon that pretense. In o...	[ "In addition, there have been numerous examples in which police or security officers have erroneously told civilians that filming or taking pictures of a particular building is unlawful and a violation, due to either national security or homeland security reasons. Examples covered in the blog include a police offic...
the reason for supermarket membership card and coupon	1. Loyalty. As in "I have a card in this store, I might save some money, so lets go back there to get groceries" 2. Purchase tracking. The store can tell exactly what you bought in the last 6 months. They can deduce marketing campaigns and product stocking strategies depending on what sort of customers buy what at wha...	[ "Store coupons are coupon-based discounts offered for a particular item or group of items. The issuing store will accept its own \"store coupons\", but some stores will also accept store coupons that are issued by competitors.\n", "Of the \"big four\" supermarkets, Sainsburys and Tesco and Morrisons operate loyal...
why, in the entirety of both the Islamic and Christian world, do we have a 7 day week? is there an astronomical or other historical significance to a 7 day time period? Are any European or Middle Eastern cultures in history known to have had a concept of a week of any other length than 7 days?	FYI there's a section on this in the FAQ* [Weeks, weekdays, and weekends](_URL_0_) *see the "popular questions" link on the sidebar, or the "wiki" tab above	[ "The Islamic calendar is a lunar one, so that there are twelve lunar months in a year of 354 or 355 days, being 11 days shorter than a solar year. Consequently, holy days in Islam migrate around the solar year on a 32-year cycle. Some countries in the Islamic world use the Gregorian calendar for civil purposes, whi...
how does general anxiety disorder actually work, and why is it thought to occur? is it "all mental" or chemical?	there is no difference between mental and chemical. there is no difference between physical illness and mental illness, they all take place in this physical world made of chemicals. & #x200B; as to how it works: we don't exactly know. we don't understand the brain enough to explain most mental illnesses or their med...	[ "The biological basis for anxiety disorders is rooted in the consistent activation of the stress response. Fear, which is the defining emotion of an anxiety disorder, occurs when someone perceives a situation (a stressor) as threatening. This activates the stress response. If a person has difficulty regulating this...
Why did football overtake baseball in popularity in the U.S. during the 1950s and 1960s?	One thing that should be established is that until the 60' or so College Football was much more popular then the multiple Pro leagues out there, and thus when many schools had to suspend play during WW2 that accounts for the downturn seen in the 40's. But then when everyone comes back and tons more can go to college o...	[ "College football was the bigger attraction, but by the end of World War II, pro football began to rival the college game for fans' attention. Rule changes and innovations such as the T formation led to a faster-paced, higher-scoring game. The league also expanded out of its eastern and midwestern cradle; in 1945, ...
I just mixed some Acetone and Water and the beaker warmed up. Why?	I think the answer to this question is going to be complicated, depend on the ratio of water and acetone, and ultimately have to do with the thermodynamics of how the acetone and water molecules arrange themselves. But to be overly simplified, I think you could just state that the acetone/H2O molecules fit together bet...	[ "The mixture will set up, for handling, within 4–6 hours, but requires 15 hours (at cool temperatures) to fully cure and harden. When first mixed, J-B Weld is subject to sagging or running (slow dripping), more so at warmer temperatures. After about 20 minutes the mixture begins to thicken into a putty that can be ...
why do so many people think prostitution is bad?	Many of those against legal prostitution would believe that every prostitute was forced into it, including those that might appear to have entered voluntarily. Many psychologists also have shown how prostitution is damaging to the prostitute. EDIT: Also, I, until recently, believed the best way to help the workers w...	[ "Prostitution has also become associated with a number of problems, including organized crime, government corruption and sexually transmitted diseases. Due to China's history of favoring sons over daughters in the family, there has been a disproportionately larger number of marriageable aged men unable to find avai...
What was the ratio between fighter planes and reconnaissance planes in WW1?	My copy of Amber Books' The Essential Aircraft Identification Guide: Aircraft of WWI gives numbers in August 1918 as being: * France: 34% fighter, 51% observer, 15% bomber * Britain: 55%, 23%, 22% * Italy: 46%, 45%, 9% * USA: 46.5%, 46.5%, 7% * Germany: 42%, 50%, 8% * Austria-Hungary: 63%, 28%, 9% hope that helps!	[ "Only 403 (45 percent) of the total number of sorties flown by Fighter Command were directed at the three major German raids. A further 56 (or just over 6 per cent) were standing patrols to protect shipping off the coast. Most of the remaining 427 sorties (nearly 50 per cent) were made to engage the reconnaissance ...
Are Ultraviolet rays more powerful on cloudy days?	Absolutely not. There is no physical reason why a cloud would increase the intensity of an incoming flux of ultraviolet photons. Even if [fluorescence](_URL_0_), the process by which material "processes" high energy photons into more lower energy ones, could occur inside a cloud in our atmosphere, our Sun does not pr...	[ "Sunlight is the most available free UV radiation source for use in reflected UV photography, but the quality and quantity of the radiation depends on atmospheric conditions. A bright and dry day is much richer in UV radiation and is preferable to a cloudy or rainy day.\n", "In daytime, sodium and red oxygen emis...
why is there so many different kinds of pain medication? they all seem to do the same thing (according to their descriptions), but why does tylenol work for some headaches and ibuprofen (naproxen, aspirin, etc.) work for other headaches?	Some reduce inflammation which helps relieve pain, and some block pain receptors in your cells, so you don’t feel the pain. Different drugs perform different chemical actions that help with pain in different ways.	[ "Pain medication, such as aspirin and ibuprofen, are effective for the treatment of tension headache. Tricyclic antidepressants appear to be useful for prevention. Evidence is poor for SSRIs, propranolol and muscle relaxants.\n", "Tension-type headaches can usually be managed with NSAIDs (ibuprofen, naproxen, asp...
if the tongue is a muscle, and muscles grow after the fibers are torn, why doesn't your tongue grow after being bitten?	Not the same type of tear. Otherwise, bodybuilders would go to the gym and cut themselves.	[ "Mineral and vitamin deficiencies can cause the tongue to appear beefy red and feel sore. Those deficiencies are iron, folate, and vitamin B12. A hairy tongue may be an indication of Epstein Barr virus infection and is usually seen in those infected with HIV. Other systemic diseases that can cause the tongue to for...
kneeling during/sitting in national anthem disrespect to armed forces?	It's only disrespecting the armed forces in a super roundabout way. In the US, we stand to pay respect to the flag, which represents the US. If you're in uniform (military) you also salute. Maybe other professions as well, like police and firefighters, but I don't know for sure. Our military fights for the US, and in s...	[ "During the Litany, Dr. Stewart was ordered by an attending Union officer to say the Prayer for the President of the United States that Dr. Stewart had omitted without saying any other prayer in its place. Dr. Stewart proceeded without paying any attention to the interruption; but a captain and six of his soldiers,...
How did Tenant Farmers get paid in Medieval England? Did they farm for a season, sell, then run down their savings until next season, or did they have some type of reliable income?	I have not heard any specific English form of tenancies, but tenant farming followed was broadly similar across Europe. That is not to say to say that European farming was similar everywhere, rather that tenant farming was just one of many different forms of farming. So, tenant farming was the practice where landowne...	[ "By the late Medieval period, most farming was based on the Lowland fermtoun or Highland baile, settlements of a handful of families that jointly farmed an area notionally suitable for two or three plough teams, allocated in run rigs to tenant farmers, known as husbandmen. Runrigs usually ran downhill so that they ...
Since modern OS's store the hashes of passwords, not the passwords themselves, is it possible for there to be another password that would also work because it has the same hash?	This is known as a [collision.](_URL_0_) The answer is yes, though in practice this is incredibly rare. They're suitably rare so as to not be a problem unless you're deliberately trying to exploit the vulnerability.	[ "Roger Needham invented the now common approach of storing only a \"hashed\" form of the plaintext password. When a user types in a password on such a system, the password handling software runs through a cryptographic hash algorithm, and if the hash value generated from the user's entry matches the hash stored in ...
what happens in a free falling elevator? will you go to the ceiling or stay on the floor?	If the elevator is free falling then you too are free falling inside the elevator. So you would be neither in the ceiling or on the floor. However there are a few practical concerns. First of all you most likely start off standing on the floor. So when the elevator starts to fall you will be pushed slightly upwards by ...	[ "On the last word of Serling's narration, the elevator starts its drop sequence. Rather than a simple gravity-powered drop, however, the elevator is pulled downwards, causing most riders to rise off their seats, held down by their seat belt. At least once during the drop sequence, wide elevator doors in front of th...
AskScience AMA Series: I'm Dr. Kathryn Bywaters and I am an astrobiologist at SETI working on developing new ways to look for life! Ask me anything!	What other types of life besides carbon-based can we look for on other planets?	[ "Sara Imari Walker is an American theoretical physicist and astrobiologist with research interests in the origins of life, astrobiology, physics of life, emergence, complex and dynamical systems, and artificial life. Walker is currently a fellow at the ASU-SFI Center for Biosocial Complex Systems and an assistant p...
Is there any reason 2 unflavored vodkas should taste any different?	The perfect "pure" vodka is an ethanol grain-neutral-spirit diluted with pure water to a palatable level. The differences in flavor between vodkas come from impurities or contaminants, since no process is perfect.	[ "A study conducted on NPR's \"Planet Money\" podcast revealed negligible differences in taste between various brands of vodka, leading to speculation as to how much branding contributes to the concept of \"super premium vodkas\".\n", "Vodka is traditionally drunk \"neat\" or \"straight\" (not mixed with water, ic...
How did the Europeans manage to pull of the First Crusade?	A combination of factors. a) Right after leaving byzantine territory, the crusading armies found themselves on the brink of disaster. At Dorylaeum (July, 1097), the vanguard was surrounded by the Turks and only lived another day thanks to the quick judgement of Raymond of Toulouse and Godfrey of Bouillon, who arrived ...	[ "The crusade set forth from Dijon on 30 April 1396, heading across Bavaria by way of Strasbourg to the upper Danube, from where they used river transport to join with Sigismund in Buda. From there the crusader goals, though lacking details of planning, were to expel the Turks from the Balkans and then go to the aid...
why the depth matters with water resistant devices?	The deeper you dive in water, the more pressure is applied across the entire exposed surface of an object. Gaskets (rubber components designed to keep water out) in a device can only stand so much pressure before they're breached and water begins to flood in.	[ "BULLET::::- Water resistant (soft shell) most materials block water only partially, however as technology in the outdoor industry moves forward more fully waterproof soft shells are emerging such as polartec neoshell or DryQ Elite. On the other hand, they are usually more breathable and comfortable, thinner, and c...
What happens if a GPS satellite gets KO'd?	Apparently, the minimum amount for the GPS system to be operational is 24 satellites. However, as at the moment 31 are operational, there is small chance of harm to the GPS system. If one satellite were to fail, there are enough others to keep the system working. Satellites do age and get decommissioned all the time (s...	[ "However, in dense urban areas with congested high-rise buildings, the satellite signals to the GPS receiver are often blocked and the accuracy of the results adversely affected. KMB claims that GPS would only be installed to the whole fleet until the problem is solved.\n", "The actual process of connecting a BGA...
Danish / Norwegian resistance during World War II	I don't know too much about the Danes, but my impression is that they were pretty much overrun before they had time to react. In Norway, the government had time to get out of Oslo before the Germans could capture them. One thing I believe was important was the attitude of Haakon VI, king of Norway. He refused to coope...	[ "Neutral Denmark was invaded by Nazi Germany on 9 April 1940, and was occupied for the remainder of World War II. Food shortages, communication restrictions, and transport closures followed. As Olga's sons, Tikhon and Guri, served as officers in the Danish Army, they were interned as prisoners of war, but their imp...
Why did the Guild system collapse?	Simple answer: emergence of routinized labor in a factory. Call it Taylorization, [division of labor,](_URL_0_) or whatever you like, it was the change from craft control of labor to factory-based production that ended most guilds. Longer answer is very long. Involves immigration, changes in technology, populism, a...	[ "The guild system became a target of much criticism towards the end of the 18th century and the beginning of the 19th century. Critics argued that they hindered free trade and technological innovation, technology transfer and business development. According to several accounts of this time, guilds became increasing...
if the single use plastic is already made, how is my refusal to buy these items helping the planet? they are already made and someone else will buy them?	If not as many single use plastic items get bought, companies will cut back on how many more they make in the future. That's important too.	[ "In 2017, the Thai government said that it might tax plastic bags. An \"endless debate\" has ensued in government, but no action. One reason might be the interests of powerful petrochemical firms. They maintain that plastic is not an issue if it is reused and recycled. Thai exports of polyethylene pellets and plast...
islands like hawaii seem to very quickly get diverse vegetation even though they pop up in the middle of the ocean, so where do the first seeds come from?	Seeds travel in many ways. Some get there by water, traveling on air currents (think dandelion) or by animals (bird eats seed, undigested seed from excrement finds new home), and by humans. In Hawaii's case, many of their trees and plants were brought to the island by early settlers. Edit: removed inaccurate info...	[ "The plants are zoochorous; their seeds will stick to clothing, fur or feathers, and be carried to new habitat. This has enabled them to colonize a wide range, including many oceanic islands. Some of these species occur only in a very restricted range and several are now threatened with extinction, notably in the H...
In popular culture and meme posts there's a stereotype correlating living in Southern states and incest. Is there any historical reason why this stereotype is a thing? Why aren't Northern American states associated with this stereotype instead?	The word "hillbilly" had spread far enough to make its first known appearance in print in 1900, though perhaps not quite far enough that it didn't need defining: > A hill-billie is a free and untrammelled white citizen of Alabama, who lives in the hills, has no means to speak of, dresses as he can, talks as he pleas...	[ "Through such tests, it is known that American southerners exhibit less egalitarian gender views than their northern counterparts, demonstrating that gender views are inevitably affected by an individual's culture. This also may differ among compatriots whose 'cultures' are a few hundred miles apart.\n", "Strong ...
From 1000 to 1500 CE, how centralized were European countries? Which country was the most centralized? Most decentralized?	1000CE to 1500CE was an exceptionally formative period for the rise of the nation-state, especially emerging out of the destablization and fragmentation of the Byzantine (Late Roman) Empire. Byzantium is an excellent example of the condition of empires and states at the time. From approximately the 7th century CE to th...	[ "According to Wallerstein there have only been three periods in which a core nation dominated in the modern world-system, with each lasting less than one hundred years. In the initial centuries of the rise of Europe, Northwestern Europe constituted the core, Mediterranean Europe the semiperiphery, and Eastern Europ...
Are there any other purposes of there being so much nitrogen composition in the air, other then to provide an inert atmosphere?	_URL_0_ All species need the element nitrogen, it's a building block of proteins. It was discovered that some species can use nitrogen gas and "fix" it from the air in the 19th Century. Most species however obtain their nitrogen from compounds. The atmospheric composition doesn't have any "purpose", but Earth's atm...	[ "There is an abundant supply of nitrogen in the earth's atmosphere — N gas comprises nearly 79% of air. However, N is unavailable for use by most organisms because there is a triple bond between the two nitrogen atoms in the molecule, making it almost inert. In order for nitrogen to be used for growth it must be “f...
what causes extreme heat on atmosphere re-entry and was this discovered prior to the first mission or a lesson learned later?	Not exactly air friction. Friction would be the air rubbing against the body so much as to raise the temperature to extremes. But what happens is different. In the upper atmosphere air is very thin - is not dense at all. As a body falls through that atmosphere at staggering speeds, the few air particles there are lit...	[ "The flight was an almost complete success, marred only by a heater that had inadvertently been turned off prior to liftoff and that allowed the inside temperature to drop to , a bout of space sickness, and a troublesome re-entry when the reentry module failed to separate cleanly from its service module.\n", "Orb...
Would firing something like a Star Trek phaser create recoil? How about a real life military weapon that uses lasers?	Realistic answer: No. Actual answer: Yes, a tiny, tiny, stupidly minuscule bit of recoil. The emission of photons (light) will have a bit of recoil but this will be so small, it would be very difficult to detect this. An example of this phenomenon is the potential usage of [solar sails](_URL_0_) to move spacecraft via...	[ "The plasma projectiles would be shot at a speed expected to be 3000 km/s in 1995 and 10,000 km/s (3% of the speed of light) by 2000. A shot has the energy of 5 pounds of TNT exploding. Doughnut-shaped rings of plasma and balls of lightning exploded with devastating thermal and mechanical effects when hitting their...
Why do some viruses stay in the body forever and others not?	It usually depends on the life cycle of the virus. Most viruses that you think of as being "beatable" reproduce in a highly active life cycle. They invade a cell, hijack its machinery to replicate, and then burst out when the cell can no longer hold all the virus particles. Those viruses then spread to new cells. The ...	[ "Viruses are only able to replicate themselves by commandeering the reproductive apparatus of cells and making them reproduce the virus's genetic structure instead. Thus, a virus cannot function or reproduce outside a cell, thereby being totally dependent on a host cell in order to survive. Most viruses are species...
Was there any benefit to Hitler going to war with the USSR?	> But that got me thinking, was there any benefits to him going to war with The USSR that helped his efforts on the western fronts and semi-neglected the loss of manpower? No, not really. Hitler's arrangement with the Soviet Union provided Germany with valuable oil and raw materials, allowing Germany to bypass the B...	[ "In autumn 1940, high-ranking German officials drafted a memorandum on the dangers of an invasion of the Soviet Union. They said Ukraine, Belorussia and the Baltic States would end up as only a further economic burden for Germany. It was argued that the Soviets in their current bureaucratic form were harmless and t...
Primary source from the Rape of Nanking?	[Try this digital exhibit from Yale, a collection of materials from Christian missionaries who witnessed the Rape of Nanking.](_URL_0_) For the future: If you're trying to find primary sources with Google, don't use the term "primary sources," this is a "schoolroom" history phrase and it's not used outside of teachin...	[ "\"The Rape of Nanking\" is structured into three main parts. The first uses a technique that Chang called \"the Rashomon perspective\" to narrate the events of the Nanking Massacre, from three different perspectives: that of the Japanese military, the Chinese victims, and the Westerners who tried to help Chinese c...
Why is Belarus?	Not to discourage other answers, but you might be interested in this post: [How did Belorussians and Ukrainians evolve as distinct national identities from Russia?](_URL_0_) with the top answer from /u/cheapwowgold4u. It's an older post from when AskHistorians allowed wikipedia as a source, but it's a well thought ou...	[ "Belarus (; , ), officially the Republic of Belarus (, ), formerly known by its Russian name Byelorussia or Belorussia (), is a landlocked country in Eastern Europe bordered by Russia to the northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Its capital and most populous...
why does my iphone say i have 4.4 gigs of memory used in pictures and yet i have no pictures on my phone	It's photos saved in messages, possibly cached photos. Delete some conversations, or (I highly recommend) jailbreak your phone, install iCleaner and it will clear ALL that crap out.	[ "iOS 8 added iCloud Photo Library support to the Photos app, enabling photo synchronization between different Apple devices. Photos and videos were backed up in full resolution and in their original formats. This feature almost meant that lower-quality versions of photos could be cached on the device rather than th...
Was Emperor Jimmu a real person? Who were his parents?	In mythology Jimmu was a descendant of the Sun Goddess, Amaterasu. Ugayafukiaezu no Mikoto, a Kami (a god) is his father. Considering that both of these people are gods, it is unlikely that he was a real person. But that's the short answer. The long answer is a bit more in depth: The Japanese migrated to the Japanese...	[ "The origins of the Japanese imperial dynasty are obscure, and it bases its position on the claim that it has \"reigned since time immemorial\". There are no records of any Emperor who was not said to have been a descendant of other, yet earlier Emperor ( \"bansei ikkei\"). There is suspicion that Emperor Keitai (c...
how do we know there are more colors than can be seen with the naked eye, if we can't... see them?	A color is just a particular wavelength of light that happens to trip some of the cells in our eyes to some degree. We know for a fact that there are wavelengths of light that do not activate those cells in our eyes--but those are still wavelengths of light, which can be called a color. Additionally, we know for a ...	[ "Humans are able to see an array of colours because light in the visible spectrum is made up of different wavelengths (from 380 to 760 nm). Our ability to see in colour is due to three different cone cells in the retina, containing three different photopigments. The three cones are each specialized to best pick up ...
apple vs. samsung lawsuits	Basically, the evidence shows the Head Design Team from Samsung went through the iPhone point by point and compared it to their own TouchWiz OS and phone. They made suggestions that Samsung adopt hundreds of little features and design cues from the iPhone. You can look at the final OS changes on a phone and see they fo...	[ "Samsung counter-sued Apple on April 22, 2011, filing federal complaints in courts in Seoul, South Korea; Tokyo, Japan; and Mannheim, Germany, alleging Apple infringed Samsung's patents for mobile-communications technologies. By summer, Samsung also filed suits against Apple in the British High Court of Justice, in...
Could the Industrial Revolution have happened earlier in history, or did it happen as soon as the world was "ready" for it?	This is basically directly taken from Ian Morris' Why the West Rules for Now which I highly recommend. Its a great read. There were a few reasons why the Industrial Revolution happened when it did. Technology continued to accumulate over centuries and centuries making a breakthrough to industrialization possible, s...	[ "The \"industrial revolution\" is the historical event that ushered in industrial civilization. The modern world has evolved further following development in mass production and information technology (allowing service economy, and information society).\n", "The Scientific Revolution changed humanity's understand...
eili5 how does file encryption work?	Encryption takes a key, and combines it with the message mathematically to scramble it. A simple encryption scheme might move the letters of the message forward in the alpha. If my key was 1 2 3, and my message was REDDIT, it would encrypt it like this: R, 1 - > S E, 2 - > G D, 3 - > G D, 1 - > E...	[ "With transparent encryption, the files are accessible immediately after the key is provided, and the entire volume is typically mounted as if it were a physical drive, making the files just as accessible as any unencrypted ones. No data stored on an encrypted volume can be read (decrypted) without using the correc...
why are wall outlets 110v or 220v? those seem like such arbitrary values; why not 100v?	In many parts of the world, electric companies sprung up, each making their own flavor of power (certain voltage, amperage, cycles per second, etc.). This caused one really big problem: you buy a lamp and it works in your house, then you move to another part of town, and it won't work because the power is different. ...	[ "For example, in 2012, Hawaii residents had the highest average residential electricity rate in the United States (37.34¢/kWh), while Louisiana residents had the lowest average residential electricity costs (8.37¢/kWh). Even in the contiguous United States, the gap is significant with New York residents having the ...
What exactly is the reaction happening when I clean tarnished silver with bicarb, Aluminium, and hot water?	Aluminium is naturally very reactive, but is often covered in a thin layer of passivating aluminium oxide that prevents the rest of the aluminium from reacting. Aluminium oxide is amphoteric, and thus easily soluble in alkaline or acidic solutions. The hot bicarb solution is alkaline, and dissloves the aluminium oxide,...	[ "Ethyl alcohol is sometimes added to the slurry mixture to help dry out excess water. The slurry mixture is applied throughout the piece until completely polished. Dark tarnish spots are sometimes located on the surface and may need to be polished more than once to remove. Over polishing is an issue with silver and...
why are doctors england on strike?	The UK government wants to introduce a new contract for doctors. The changes would include modification of standard working hours which will result in unsafe working practices and reduced pay, as well as potentially causing issues with staffing and recruitment. The contract aims to "introduce" the idea of a 7-day NHS, ...	[ "On the 12th of January 2016, Junior Doctors in England took part in the first general strike across the NHS, the first such industrial action in 40 years. Emergency care was still provided. There have been claims that the Medical Director of NHS England, Professor Sir Bruce Keogh, has used performance target level...
tuition is increasing faster than inflation. cable prices are increasing faster than inflation. healthcare costs too. isn't that the definition of inflation?	First, you need to understand how Inflation is measured. Its simply not practical to have the primary inflation number we talk about include every possible product that you could by or spend money on, not to mention the problems of deciding how to weight different items. Instead, a "basket" of goods is selected that is...	[ "With higher education costs on the rise, many students are becoming sensitive to every aspect of college pricing, including textbooks, which in many cases amount to one tenth of tuition costs. The 2005 Government Accountability Office report on college textbooks said that since the 1980s, textbook and supply price...
Did they have ads as we know them centuries ago?	Aha! What a fun topic! For me, this one is gonna go back....well, a couple of millenia, but I hope you'll be alright with that. I can't speak much to advertisement later than the Roman period, but advertisement in the Roman city is a wonderful thing in itself! Some notes before we start: Shorthand in the Latin quotes....	[ "The history of advertising can be traced to ancient civilizations. It became a major force in capitalist economies in the mid-19th century, based primarily on newspapers and magazines. In the 20th century, advertising grew rapidly with new technologies such as direct mail, radio, television, the internet and mobil...
why does radiation in a disaster stay for so long? (like in chernobyl)	All radioactive materials have a half-life. The half-life is the amount of time it takes for half of the material to decay into something else. If the material from Chernobyl has a half-life of 1000 years then after 1000 years only 1/2 of it will be gone. After 2000 years, 3/4 of it will be gone. Etc. Some radioactiv...	[ "At Chernobyl, approximately 10 times the amount of radiation was released into the atmosphere as was released from Fukushima I through 12 April 2011. The total amount of radioactive material still stored at Fukushima is about 8 times that stored at Chernobyl, and leakage at Fukushima continues.\n", "Although the...
Does leaving a refrigerator door opened for about 20 seconds actually use up a large enough amount of energy/ power to consider not leaving it open for that long?	I vaguely recall actually calculating this for a question long ago. The answer is basically no, it's not a huge waste. For starters, the air in the refrigerator is essentially stagnant; you're not going to get a large amount of mixing of the cold air with the surroundings in the span of 20 seconds, unless you have a f...	[ "A defrosting procedure is generally performed periodically on refrigerators and freezers to maintain their operating efficiency. Over time, as the door is opened and closed, letting in new air, water vapour from the air condenses on the cooling elements within the cabinet.\n", "Disposal of discarded refrigerator...
Are there any indications that there are elements beyond the 118 we have currently discovered or synthesized? If so, is there any indication that there is a finite number of elements, other than their increasingly short halflives?	A neutron star is very similar to an extremely heavy atomic nucleus. Consider that neutron stars contain ~10^57-58 particles. If a neutron star grows much heavier than this it will collapse into a black hole. Therefore there is a finite limit to the number of possible atomic elements, but it's a very large number. ...	[ "The elements from atomic numbers 1 (hydrogen) through 118 (oganesson) have been discovered or synthesized, completing seven full rows of the periodic table. The first 94 elements all occur naturally, though some are found only in trace amounts and a few were discovered in nature only after having first been synthe...
Actual health impacts of eugenics programs	It's not really possible to know. These programs were not scientifically rigorous or adequately controlled, and the sheer number of factors that may or may not impact how individual people or entire societies develop means that it cannot be said with any degree of confidence whether or not eugenics programs worked.	[ "A major criticism of eugenics policies is that, regardless of whether \"negative\" or \"positive\" policies are used, they are susceptible to abuse because the genetic selection criteria are determined by whichever group has political power at the time. Furthermore, \"negative eugenics\" in particular is criticize...
How much air in one breath came from the previous one?	[Anatomical deadspace](_URL_0_), which is the term for the air that doesn't participate in gas exchange within the body is roughly 1ml/kg. However, it's not this simple to example, at the small airways, there really is no flow-rate to be measured, it's purely diffusion. If we take into consideration that the first ...	[ "A typical human breathes between 12 and 20 times per minute at a rate primarily influenced by carbon dioxide concentration, and thus pH, in the blood. With each breath, a volume of about 0.6 litres is exchanged from an active lung volume (tidal volume + functional residual capacity) of about 3 litres. Normal Earth...
What were the main arguments American Anti-Federalists made against the first article of the Constitution?	I assume you have looked at the anti-federalist papers?	[ "The Anti-Federalists proved unable to stop the ratification of the US Constitution, which took effect in 1789. Since then, the essays they wrote have largely fallen into obscurity. Unlike, for example, The Federalist No. 10 written by James Madison, none of their works are mainstays in college curricula or court r...
What's the most expensive part of launching a spacecraft?	Fuel is pretty cheap. The problem is that you need so much of it that you have to shave every ounce of weight off your structure and engines in order to be able to make it to space. This means that your safety margins need to pretty small, leaving little room for error and uncertainty. To reduce this uncertainty, you...	[ "Present-day launch costs are very high – $2,500 to $25,000 per kilogram from Earth to low Earth orbit (LEO). As a result, launch costs are a large percentage of the cost of all space endeavors. If launch can be made cheaper, the total cost of space missions will be reduced. \n", "The cost of the mission was $327...
What was the public reaction in Australia after gun control laws were enacted?	A journalist on the Australian Broadcasting Corporation's main news and current affairs show The 7:30 Report, said on May 9th, 1996, that "Australian massacres have a dulling familiarity. Public shock and outrage is soothed by assurances of tougher gun laws. But as public outcry dissipates, often so does political wi...	[ "The then Prime Minister of Australia, John Howard, initiated another review of Australian gun laws, the last having been after the Port Arthur massacre, after it was discovered that Xiang had acquired his firearms legally. The Victorian State Government prepared new laws doubling the punishment for misuse of handg...
Salt and Ice	I would say that the ice chest without the salt added stays colder for longer. The chest with the salt gets colder as the ice melts and absorbs the latent heat of fusion. However, since heat transfer is proportional to the temperature difference between the substance and its environment, the 'cryo bath' will warm fas...	[ "Halite is also often used both residentially and municipally for managing ice. Because brine (a solution of water and salt) has a lower freezing point than pure water, putting salt or saltwater on ice that is below will cause it to melt. (This effect is called freezing-point depression.) It is common for homeowner...
serious question - is there science behind a face that appears more desirable to punch? aka: "punchable face"	There is no definitive single answer, but there are some answers. It probably shouldn't be a surprise that given how sensitive to facial expressions humans are, that we'd have the capacity for a strong reaction. By the way, there is a German word for the phenomenon you're describing, called "Backpfeifengesicht"... or r...	[ "Punch is aggravated by his whining child, nagging wife (Judy), and ineffective bureaucracy. This eventually leads to Punch hitting other characters with his slapstick, but it is a very ritualized form of violence. Traditional shows ended with Punch defeating the ultimate evil and proclaiming \"Huzzah, Huzzah, I've...
what is a senator and what is a congressman?	Congress is more or less the US equivalent of the UK's Parliament. Like the UK Parliament, it has two houses. The lower house is the House of Representatives. The people who sit in that are called Congressmen/women. It's very much like the UK's House of Commons. The entire country is split into districts (same concept...	[ "Congress is a bicameral legislature. The upper house, the Senate, is composed of 24 senators elected via the plurality-at-large voting with the country as one at-large \"district.\" The senators elect amongst themselves a Senate President. The lower house is the House of Representatives, currently composed of 292 ...
why do people become outraged and upset at other people's sexual preferences?	My theory is this: we humans have found the need to become self-controlled and disciplined for the good of our society. We keep our basic instincts in check so that we can focus on working together to build things and to make our lives better and free of danger. Obviously most of us like sex... but we also don't have ...	[ "The increase in sexual content in modern society often results in a more nonchalant approach to sexually suggestive behavior. People, predominantly women, often act in a way that they themselves do not consider to be sexually suggestive but which can be misinterpreted by others. For example, wearing clothes or ski...
why constant friction leads to orgasm? what makes the brain think "yeah... i wasn't sure you were having sex, but now that 20 minutes has passed i'm certain... take the reward now"?	As far as I know (not a biologist) human males generally last so long because they train to, because they want to get human females off, which i'm guessing have a longer time to orgasm to encourage them to have more sex, to guarantee pregnancy. Since monogamy and marriage and stuff is a human cultural thing, from natur...	[ "An orgasm is believed to occur in part because of the hormone oxytocin, which is produced in the body during sexual excitement and arousal and labor. It has also been shown that oxytocin is produced when a man or woman's nipples are stimulated and become erect. Komisaruk also relayed, however, that preliminary dat...
What was up with the Anti-Masonic Party? Why was Freemasonry considered such a pressing issue in 17th century America that people created a whole political party over it?	I can give you a brief answer, copied from an earlier question I answered on this sub. Perhaps someone more knowledgeable can step in to supplement: An incident occurred in the 1820s that sparked a wave of anti-masonry. A man claimed he was going to publish the masonic "secrets" (rites and symbols) ...and then went m...	[ "The major opponent of Freemasonry was the Roman Catholic Church so that in countries with a large Catholic element, such as France, Italy, Spain and Mexico, much of the ferocity of the political battles involve the confrontation between what Davies calls the reactionary Church and enlightened Freemasonry. Even in ...
what happened to the panama papers story? it was supposed to be this giant scandal, yet it seems to have disappeared.	1. It's still a thing, but given that there haven't been any new major revelations (e.g. The Pope) most news organizations have chosen to focus on more topical things (The Euro 16, Brexit, etc.) 2. No prominent Americans were listed, hence why it's gotten little to no attention in the US. Most Americans don't give a s...	[ "The documents were dubbed the Panama Papers because of the country they were leaked from; however, the Panamanian government expressed strong objections to the name over concerns that it would tarnish the government's and country's image worldwide, as did other entities in Panama and elsewhere. This led to an adve...
what factors cause people from different countries to protest differently?	Nothing's to say that can't happen in the US, but a part of it comes out of necessity. Many parts of Asia are heavily populated, and not just heavily, but densely. The need to be clean isn't just a good idea, it has roots in survival. And it's convention. People do it so you do it. People see you do it so they do ...	[ "Protesting outside of one’s home country is a relatively new phenomenon. Nicole Constable, professor of anthropology at the University of Pittsburgh, has noted that the potential ability for them to protest relies upon their pseudo stateless nature. While FDWs receive visas to live and work temporarily within thei...
At what point did Australians and New Zealanders begin to consider themselves as distinct from the British?	I wrote about this partly in my undergraduate thesis. Similar to the colonization of America, settlers in the Antipodes experienced a lifestyle hugely different from what they or their parents had experienced in Europe. Australian/American/Canadian/New Zealand (to an extent) evolved as a response to their new environ...	[ "As a result of many shared linguistic, historical, cultural and geographic characteristics, Australians have often identified closely with New Zealanders in particular. Furthermore, elements of Indigenous, American, British, and more recent immigrant customs, languages, and religions have also combined to form the...
how on earth do batteries work?	They have a chemical inside that is capable of holding extra electrons. When you charge them, you use the energy from the power plant ( or solar panels/ wherever the hell it comes from) to pump the chemical to a higher energy state (lots of extra electrons). When you discharge a battery you complete a circuit from the ...	[ "An Earth battery is a pair of electrodes made of two dissimilar metals, such as iron and copper, which are buried in the soil or immersed in the sea. Earth batteries act as water activated batteries and if the plates are sufficiently far apart, they can tap telluric currents. Earth batteries are sometimes referred...
If dark matter is a matter, then what would it look like if you held it in your hands?	Dark matter, according to the most popular theories at the moment, consists of weakly interacting massive particles, or WIMPs. Because they interact so weakly, in particular having no electromagnetic interaction, WIMPs stream through you much like neutrinos do. Thus, you can't really hold dark matter in...	[ "Dark matter is defined as hypothetical matter that is undetectable by its emitted radiation, but whose presence can be inferred from gravitational effects on visible matter. It has been used in a variety of fictional media, including computer and video games and books. In such cases, dark matter is usually attribu...
if things with different mass fall at the same velocity, why do heavier things cause more 'damage' when they land?	Force = mass x acceleration As you point out, objects fall at the same rate, i.e. acceleration is constant. So, for falling objects, force is proportional to mass. Using your example, a 1 ton (1,000 kg) ball will hit with exactly 1,000 times more force than the 1kg ball.	[ "The reason why the object does not fall down when subjected to only downward forces is a simple one. Think about what keeps an object up after it is thrown. Once an object is thrown into the air, there is only the downward force of earth's gravity that acts on the object. That does not mean that once an object is ...
how does a charger charge your phone for a split second after it was removed from the socket?	Do you think because the icon shows charging that it is actually charging? Or the software just hasn't updated the screen yet?	[ "The charge control consists of a pressure switch built into the cell, which disconnects the charging current when the internal cell pressure rises above a certain limit (usually 200 to 300 psi or 1.4 to 2.1 MPa). This prevents overcharging and damage to the cell.\n", "If a battery has been completely discharged ...
Why do mitochondria need their own DNA?	As has been said, endosymbiotic theory which is pretty widely accepted states that both chloroplasts and mitochondria were once bacteria of their own right. We believe the modern day equivalents are cyanobacteria and proteobacteria respectively. Some nice sets of evidence: * Circular genomes as seen in bacteria * No...	[ "Mitochondria are thought to be organelles that developed from endocytosed bacteria which learned to coexist inside our cells. These bacteria maintained their own DNA, the mitochondrial DNA (mtDNA), which codes for components of the electron transport chain (ETC). The ETC is found in the inner mitochondrial membran...
the senate bill 5 being discussed in today's filibuster in the texas senate.	Might be a little over EIL5, but meh... The bill does a few things. From [_URL_1_](_URL_4_): * The bill would restrict abortions after 20 weeks of pregnancy * Require all clinics to be certified as ambulatory surgical centers * Require abortion doctors to have admitting privileges at a local hospital. Problems with...	[ "On June 25, 2013, Davis held a thirteen-hour-long filibuster to block Senate Bill 5, a measure which included more restrictive abortion regulations for Texas. The filibuster played a major role in Senate Democrats' success in delaying passage of the bill beyond the midnight deadline for the end of the legislative ...
Are they any cases of animals using covering or "clothes" to protect themselves from the environment as humans have done?	Hermit crabs are an obvious example. Pigs will slather themselves in mud to cool off. You could call a burrow a kind of "clothing" that animals "put on" to protect themselves from the environment. The biggest problem is that the natural world doesn't present a lot of things which you can really use as a covering (w...	[ "Animal rights activists generally protest the use of animal hides for human clothing. Forms of protest range from PETA's \"I would rather go naked than wear fur\" campaign, although more shocking and direct action, like damaging furs with red paint in imitation of blood, has been toned down, like the \"Ink, not Mi...
What were relations between medieval Muslims and medieval Buddhists like?	As I mention [in this post](_URL_0_) to almost the same question, the initial Buddhist literary response to Islam was highly negative. I'd welcome other perspectives, of course, especially from the Muslim side and on a more subaltern level.	[ "During the Middle Ages, Muslims came into conflict with Zoroastrians during the Islamic conquest of Persia (633-654); Christians fought against Muslims during the Byzantine-Arab Wars (7th to 11th centuries), the Crusades (1095 onward), the Reconquista (718-1492), the Ottoman wars in Europe (13th century onwards) a...
why does a magnetic field do no work on a stationary particle but yet electric field does work on it?	A magnetic field does no work on a point charge under any circumstances. The magnetic force on a stationary charge is zero. If the charge is moving, then there is a magnetic force of qvxB, which is always perpendicular to v, so it doesn't do any work.	[ "Because the magnetic force is perpendicular to the velocity, it performs no work and requires no energy—nor does it provide any. Thus magnetic fields (like the Earth's) can profoundly affect particle motion in them, but need no energy input to maintain their effect. Particles may also get steered around, but their...
why do we sometimes twitch or spaz when we get a random chill?	Those are transient myoclonic jerks . These are just short burst of muscle contractions that you see especially when you are falling sleep. These are similarly seen in many physiological and pathological conditions. If excessive they are called myoclonic seizures.	[ "Chills are commonly caused by inflammatory diseases, such as the flu.. It is also common in urinary tract infections. Malaria is one of the common reasons for chills and rigors. In malaria, the parasites enter the liver, grow there and then attack the red blood cells which causes rupture of these cells and release...
why does your arm shake when you flex really hard?	When you stretch or flex your muscles, they can affect the body’s nervous system, which in effect controls the body’s muscle movements. When the body becomes overly stressed, it can cause involuntary muscle spasms.	[ "The overuse of the coracobrachialis can lead to stiffening of the muscle. Common causes of injury include chest workouts or activities that require one to press the arm very tight towards the body, e.g. work on the rings in gymnastics. Symptoms of overuse or injury are pain in the arm and shoulder, radiating down ...
What would we see if the speed of light was, say, 1ms^-1?	This is actually a common thought experiment in special relativity. The answer is, nothing would really change, but massive relativistic effects would be observable in everyday life. Also, everything in the universe would be limited to a speed of 1m/s since the speed of light is the top speed that anything can travel (...	[ "The speed of light is (by definition) exactly 299,792,458 m/s, very close to 300,000,000 m/s. This is a pure coincidence, as the meter was originally defined as 1/10,000,000 of the distance between the Earth's pole and equator along the surface at sea level, and the Earth's circumference just happens to be about 2...
What are the recommended sources for the history of mercenaries and, to a lesser extent, the development of professional fighting forces in Europe from the collapse of the WRE to the early medieval period?	Absolutely try to find a copy of David Parrott’s The Business of War. It’s also a massive book, and it’s more focused on the late medieval and early modern periods. BUT it does contain a very useful introduction that will give you an idea of the way mercenaries have been written about in European history. It also con...	[ "During the Late Middle Ages, mercenary forces grew in importance in Europe, as veterans from the Hundred Years War and other conflicts came to see soldiering as a profession rather than a temporary activity, and commanders sought long-term professionals rather than temporary feudal levies to fight their wars. Swis...
plasma, in the electrical sense. why is it its own state/phase?	Plasma forms when you heat up a gas to really high temperatures. The electrons get ripped away from the atoms due to their high energy. This is called ionization. This makes plasma highly electrically conductive. Plasma is its own state of matter because its properties are so fundamentally different from a gas, in the ...	[ "Plasma is a state of matter in which an ionized gaseous substance becomes highly electrically conductive to the point that long-range electric and magnetic fields dominate the behaviour of the matter. The plasma state can be contrasted with the other states: solid, liquid, and gas.\n", "Plasma consists of a mixt...
why are vehicles insured, instead of people/drivers?	I some countries it's actually both. The vehicle is insured, but the insurance won't cover driver liability, so the driver needs their own insurance too.	[ "With the onset of fully autonomous cars, it is possible that the need for specialized automobile insurance disappears and that health insurance and homeowner's liability insurance instead cover automobile crashes, much in the same way that they cover bicycle accidents. Moreover, as cases of traditional negligence ...
what's the point of the russians visiting the moon in 2029 when we're planning on visiting mars in the 2030's?	Why go on holiday to the caravan park this year when you know you're going to go on holiday to DISNEYLAND next year? There's still things for us to Do on the Moon - places yet unmapped, below surface exploration, samples to collect. Sure we're going to Mars, but that doesn't mean we should Not go to the Moon as well, ...	[ "A number of Mars mission concepts and proposals have been put forth by Russian scientists. Stated dates were for a launch sometime between 2016 and 2020. The Mars probe would carry a crew of four to five cosmonauts, who would spend close to two years in space.\n", "Three spaceflights to the Moon are planned to t...
How can meteor fragments found on earth possibly be so frequently described as 'martian'? How can we possibly assert their origin?	The quote below is taken directly from the [Martian Meteorite](_URL_0_) page of Wikipedia: By the early 1980s, it was obvious that the SNC group of meteorites (Shergottites, Nakhlites, Chassignites) were significantly different from most other meteorite types. Among these differences were younger formation ages, a di...	[ "A Martian meteorite is a rock that formed on the planet Mars and was then ejected from Mars by the impact of an asteroid or comet, and finally landed on the Earth. Of over 61,000 meteorites that have been found on Earth, 224 were identified as Martian . These meteorites are thought to be from Mars because they hav...
after the initial sleepiness feeling, why do we suddenly feel more alert after a few hours pass your normal sleeping time before you suddenly feel lethargic and sleepy again?	A certain sleep writer suggests it's because there is a metabolitic release timed to coincide with the early part of sleep intended to for the heavy lifting your lymphatic and endocrine systems will do in the early part of sleep. Apparently this is the "second wind" we feel at approximately 10pm, and being asleep at th...	[ "Disrupted sleep patterns are characteristic of Smith–Magenis syndrome, typically beginning early in life. Affected people may be very sleepy during the day, but have trouble falling asleep and awaken several times each night, due to an inverted circadian rhythm of melatonin.\n", "Diagnosing sleep apnea usually r...
why do fermented foods turn into alcohol and cause intoxication?	Yeast. Yeast is a microscopic fungi that is intentionally added to the process of making alcoholic drinks. It consumes the sugars, and excrete alcohol. As the alcohol content rises, the yeast dies off. They also produce CO2, which is why beer is carbonated (at least traditionally, now its added) So beer is essentially...	[ "Several species of the benign bacteria in the intestine use fermentation as a form of anaerobic metabolism. This metabolic reaction produces ethanol as a waste product. Thus, human bodies contain some quantity of alcohol endogenously produced by these bacteria. In rare cases, this can be sufficient to cause \"auto...
Were places like New Jersey, New York, New South Wales, etc. so named because of a resemblance in climate/topography to Jersey, York, Wales, etc., or because the original settlers were from those regions of the British Isles?	New Jersey was so named because the land it encompasses was an award from the King Charles II to Sir George Cartalet for his loyalty during the English Civil War. Sir Goerge was both originally born on the isle of Jersey and served as a governor there, so the land was eventually renamed, in his honor, by the Duke of Y...	[ "The region of New England in the United States has numerous place names derived from the indigenous peoples of the area. New England is in the Northeastern United States, and comprises six states: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. Listed are well-known names of towns, sig...

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