Split (2)

train · 226k rows

question stringlengths 3 301	answer stringlengths 9 26.1k	context list
Can a fusion reaction occur near the boundary of the event horizon of a black hole with enough material?	It is probably not possible for sustained fusion to occur near a black hole, but some fusion may occur on a small scale. Matter falling into a black hole can (if the black hole is large enough) attain incredibly high speeds, even significant fractions of the speed of light. If a black hole accumulates a large cloud of...	[ "BULLET::::- the Schwarzschild generating plane wave, a gravitational plane wave which, should it collide head-on with a twin, will produce in the \"interaction zone\" of the resulting colliding plane wave solution a region which is locally isometric to part of the \"interior\" of a Schwarzschild black hole, thereb...
which is the best theory on how the world will function in ~100 years (socially, economically etc) and what reasoning supports this/these theories?	there is no way to decide which theory is "best", and there is no good theory that can be done up in one Reddit post, do i suggest you read some books instead the best theory i've read syas that in a hundred years, most countries will have space colonies, which will be used to gather energy and minerals. Far East Asia...	[ "The \"Dynamics of Growth in a Finite World\" provides several different scenarios. The \"reference run\" is the one that \"represent the most likely behavior mode of the system if the process of industrialization in the future proceeds in a way very similar to its progress in the past, and if technologies and valu...
Question about the magnetic field in relation to the human brain.	There's no reason to think it would, because magnetic fields have an incredibly small effect on chemistry (I neglect them all the time in doing theoretical calculations), and the Earth's magnetic field is very weak. It's more surprising, really, that there are birds who've evolved an ability to sense it at all. Anyway...	[ "Some researchers also suggest that humans possess a magnetic sense, proposing that this could allow certain people to use magnetoreception for navigation. The role of magnetite in the brain is still not well understood, and there has been a general lag in applying more modern, interdisciplinary techniques to the s...
what goes into making a new font and how hard is it?	Making a new font is a relatively simple process, but can be a lot of work depending on how detailed you want it to be, and how many different letters you want it to span. In essence all you do is you open up MS paint, draw your letter, and save it. Then rinse and repeat for every letter in your font. You then just n...	[ "are continually added to it, and common font formats cannot contain more than 65,535 glyphs (about half the number of characters encoded in Unicode). As a result, font developers and foundries incorporate new characters in newer versions or revisions of a font, or in separate auxiliary fonts intended specifically ...
Mouse models for disease?	The answer varies depending on the model. If the gene or mutation that causes the gene is known, the mouse model is usually made by creating that same mutation in the mice. Long QT syndrome is an example of such a disease that has been studied this way. If the genetic cause isn't known, or if the cause isn't genetic in...	[ "Many mouse models are named after the gene that has been inactivated. For example, the p53 knockout mouse is named after the p53 gene which codes for a protein that normally suppresses the growth of tumours by arresting cell division and/or inducing apoptosis. Humans born with mutations that deactivate the p53 gen...
How realistic was Chiang Kai-shek/the Republic of China invading and retaking Mainland China?	Well until someone with perhaps more verifiable sources can comment, I can take a shot at this based on my experiences interviewing villagers in Southwest China and urbanites in Taiwan. In addition, I will try to tie this in with what I learned from both Chinese/Taiwanese professors, and while in the United States unde...	[ "After several unsuccessful feigned invasions between August 1971 and June 1973, in the lead up to the main landings, the 1973 coup which witnessed Nie Rongzhen's rise to power in Beijing drove Chiang to call off all further false attacks and commence full landing operations. Having said this, according to Gen Huan...
Can we ever know the exact area of a circle if the decimal part of pi is infinite?	Yes. If the radius of a circle is r, the area enclosed by the circle is πr^(2). I think you are confused between what it means to know a number exactly and what it means to have a terminating decimal representation of that number. In fact, a lot of undeserved attention is paid to base representations, when they rea...	[ "In 1585 Anthonisz discovered that the ratio of a circle's circumference to its diameter, later called pi, approximated the fractional value of . His son Adriaan Metius later published his father's results, and the value is traditionally referred to as Metius' number'.\n", "Base π can be used to more easily show ...
Is there something better than History of the World? (J.M. Roberts, 2007)	It's probably the best book to start with. If you tell us more specifically, what you are looking for, we may be able to give you better recommendations. For general world history, A World History by Clive Ponting is quite good too. It focuses more on the "East", while Roberts' focus is the "West".	[ "History of the World is a compendium written by a collection of noted historians. It was edited by William Nassau Weech, M.A., a former Headmaster of Sedbergh School (and a very early aficionado of downhill skiing who also wrote \"By Ski in Norway\", one of the first British accounts of the sport). First published...
Magnets and Space Travel?	Let's apply Fermi method or order of magnitude calculation. If you're moving at about escape velocity, ~10 km/s, then you have to displace about 1 ton per kilometer of air per 1 m^2 of frontal area, so that would be 10 tons/s/m^2. At these speeds a blunt heat shield is the only option, let's say 1 m^2 frontal area. Cha...	[ "Project Magnet, led by senior radio engineer Wilbert B. Smith from the Department of Transport, had the goal of studying magnetic phenomena, specifically geomagnetism, as a potential propulsion method for vehicles. Smith believed UFOs were using this method to achieve flight. The final report of the project, howev...
Will a light source change direction inside a black hole?	> Suppose a flashlight is falling into a black hole facing outwards. Since light cannot escape the black hole, and a trajectory of a single photon is smooth, I would assume that as soon as the flashlight crosses the event horizon, its particles can no longer emit light in the direction towards the event horizon. Is th...	[ "While light can still escape from the photon sphere, any light that crosses the photon sphere on an inbound trajectory will be captured by the black hole. Hence any light that reaches an outside observer from the photon sphere must have been emitted by objects between the photon sphere and the event horizon.\n", ...
why can healthy eyes look in only one direction, i.e. why can’t our eyes look in different directions from each other?	They can be trained to look independently, but our body was evolutionarily selected for the two eyes to work together. It's hard to break the instinct to utilize them in tandem, and there is very little advantage to doing that.	[ "Intermediate directions are controlled by simultaneous actions of multiple muscles. When one shifts the gaze horizontally, one eye will move laterally (toward the side) and the other will move medially (toward the midline). This may be neurally coordinated by the central nervous system, to make the eyes move toget...
how and why is there a standard for cylindrical batteries, and why hasn't it happened for flat batteries?	There are numerous standards for flat batteries. Hearing aides have several standardized sizes, as do watches. Phone makers/companies also tend to have standardized sizes between specific brands or range of brands. They want you to be somewhat limited in options though so that you have to buy replacements from them.	[ "The third-generation includes mechanical mods and variable voltage devices. Battery sections are commonly called \"mods,\" referencing their past when user modification was common. Mechanical mods do not contain integrated circuits. They are commonly cylindrical or box-shaped, and typical housing materials are woo...
Common cloth materials in medieval Europe?	They weren't that expensive because they were home grown. Anyone could put in a patch of flax among the other crops. Women could pull it (one does not cut it and shorten the fibres), though men could help. After that it was a woman's job to rett the flax in the stream to rot off the outer coating and pith. Then the fib...	[ "In medieval times, rulers, the nobility and senior churchmen brought many of their fabrics from the Republic of Ragusa. The most common fabric for ordinary Serbs was \"sclavina\" or \"schiavina\", a coarse woollen fabric. Linen was also made within Serbia while silk was grown at the Dečani Monastery as well as nea...
if it is thought that dreams only last for fractions of a second at a time and it is our brains that interpret them as longer, what is happening when we talk in our sleep?	Good question! Where did you get that information, that dreams only last for fractions of a second? If your girlfriend talks in her dream and in real life simultaneously then that becomes impossible - you're right! And if it is impossible then the conclusion must be: it isn't true. Dreams vary in lenght, the further ...	[ "Accumulated observation shows that dreams are strongly associated with REM sleep, during which an electroencephalogram shows brain activity to be most like wakefulness. Participant-nonremembered dreams during NREM are normally more mundane in comparison. During a typical lifespan, a human spends a total of about s...
What's the best way to use the Bible, when appropriate, as a Primary Source?	I think a lot of it depends on the level of scholarship. I know that many scholars use the New Revised Standard Edition when a simple verse quotation is required. It was created in 1989 to be good for devotional use as well as scholarly use. Learning the biblical languages and using ancient copies is done, but this i...	[ "BULLET::::- Using Primary Sources as Evidence is the ability to locate, choose, understand and provide context for the past using primary sources. This approach to reading a source will be dependent on the kind of source being used and the kind of information the user is trying to find (e.g. reading to a book for ...
When and how did the concept of political veto arise?	The romans created it. Veto means "I forbade" in latin and the right of veto was the privilege of the tribunes of the plebs. When one of them stood up to say "Veto" it blocked the decision. Ironically what was originally a tool to protect the plebeian against patrician abuses of the beginnings of the republic became at...	[ "The institution of the veto, known to the Romans as the \"intercesio\", was adopted by the Roman Republic in the 6th century BC to enable the tribunes to protect the mandamus interests of the plebs (common citizenry) from the encroachments of the patricians, who dominated the Senate. A tribune's veto did not preve...
what would happen to a person if they were to undergo a brain transplant?	This would technically be a body transplant, you are your brain.	[ "Even with proper identification and treatment, the majority of patients who present in the neonatal period have severe neurological and intellectual impairments. Liver transplantation cannot cure brain damage which has already occurred, but it will prevent future hyperammonemic episodes and prevent further damage....
why is snowden seen as such a hero?	Because of the breadth of what his leaks revealed. We spy on our allies. We spy on our own private citizens. We spy on neutral third parties that are no threat at all like fucking Brazil. We spy on everything, because we can, and because noone will stop us. Also, the [NSA doesn't really do much to not appear car...	[ "In regards to Snowden's presence, the filmmakers stated that while Snowden is \"a central character, he is not the most prominent. It is more about the maelstrom of events surrounding him.\" This was because they knew too little about Snowden himself to give him a more prominent role in the story. Lee said that th...
What happens to an island formed in a hotspot when in a subduction zone?	This depends a bit on the proximity of the hotspot to the subduction zone and the nature of the material that makes up the island / feature. In a general sense, as plate motion translates an oceanic island away from the hotspot, the island will start to 'sink' as the area around the oceanic island cools (cooler crust =...	[ "On the subducting side of the island arc is a deep and narrow oceanic trench, which is the trace at the Earth's surface of the boundary between the down-going and overriding plates. This trench is created by the downward gravitational pull of the relatively dense subducting plate on the leading edge of the plate. ...
A century ago, in the aftermath of WWI and with the dissolution of the Ottoman Empire, the world had to deal with millions of refugees and mass migration. How did the receiving countries deal with this influx?	This depends on a case-by-case basis. I am unfortunately unable to give you a fully-fledged answer in general, but would be happy to explain what happened in the Netherlands during the War and the immediate post-war period with (predominantly Belgian) refugees, if you are interested. I could also be of some help in ill...	[ "They were followed by other waves of immigration: during the First World War the Ottoman Empire from disintegrating, before and after the Second World War from Europe, from Arab countries because of the exodus caused in 1948 and more recently from South American countries suffering economic crises.\n", "By the 1...
what are those fake puddles of water that appear on the road and disappear as i drive closer?	Mirage. Optical illusion that form when light coming form critical angle bounce(reflection) off instead of refraction. As you approach closer you are no longer in the path of that bounced light, so it disappear	[ "Puddles commonly form during rain, and can cause problems for transport. Due to the angle of the road, puddles tend to be forced by gravity to gather on the edges of the road. This can cause splashing as cars drive through the puddles, which causes water to be sprayed onto pedestrians on the pavement. Irresponsibl...
why do so many think robert johnson is the greatest bluesman?	Everything I know about Robert Johnson I learned from the movie Crossroads, but apparently he invented The Blues, or at least wrote all the early classic Blues songs. He was able to do this because he sold his soul to the Devil.	[ "BULLET::::- Eric Clapton considers Johnson \"the most important blues musician who ever lived\". He recorded enough of his songs to make \"Me and Mr. Johnson\", a blues-rock album released in 2004 as a tribute to the legendary bluesman (it was also used in the film \"Sessions for Robert J\"). He earlier recorded \...
Do humans make bodily or vocal noises above or below the human hearing (20Hz to 20,000Hz) threshold?	Anything that causes a vibration causes a sound, because that's what sound is. While it may not be audible, pretty much any movement your body makes technically makes a sound. Waving your hand frantically may cause vibration of a few Hertz, for example, even though it's probably very quiet too. Of course, that's just ...	[ "A human is capable of hearing (and usefully discerning) anything from a quiet murmur in a soundproofed room to the loudest heavy metal concert. Such a difference can exceed 100 dB which represents a factor of 100,000 in amplitude and a factor 10,000,000,000 in power. The dynamic range of human hearing is roughly 1...
What happened to German police personnel after the Germans surrendered in WW2?	This is an interesting one. The Order Police and the Krippo generally continued as normal, as did most of the judiciary. The Gestapo was brought in front of the Nuremberg trails where it was decided the it was a criminal organisation and that all officers and administrators were collectively responsible. However, i...	[ "Shortly after the German invasion of Poland, the Nazi authorities ordered the mobilization of prewar Polish officials and the Polish police (the \"Blue Police\"), who were forced, under penalty of death, to work for the German occupation authorities. The primary task of the officials was to run the day-to-day admi...
How and when did the Star and Crescent become a symbol of Islam? What exactly does it represent?	This is primarily trying to answer another question, but it touches on the question you’re curious about: * [Why didn't the Turkish Republic change its flag?](_URL_0_) I’m afraid, though, that I come at this as someone who’s interested in the Early Turkish Republican era/the Late (19th century) Ottoman Empire, so I ...	[ "The star and crescent symbol became strongly associated with the Ottoman Empire in the 19th century, a symbol that had been used throughout the Middle East extending back to pre-Islamic times, especially in the Byzantine Empire and Crusader States which occupied the lands later assumed by the Ottoman Empire. By ex...
how come the human race still has "ugly" people if nobody wants to reproduce with them?	People still do. Edit: also Luck, two "perfect" parents wont always have a "perfect" child.	[ "The second statement says that since human history is widely diverse and complex, there are many human populations that cannot be easily classified “racially”. However, some anthropologists believe that mankind is classified into at least three major human races. Even though it is believed that there are many huma...
how did amazon gain enough popularity to support it's massive infrastructure costs?	It was one of the first dot coms, back when online shopping wasn't a thing yet. They also started niche with just books - an industry which (at that time) had lousy overpriced competition and was impossible for brick and mortar stores to compare on inventory / price. Great place to start. Then after they became the ...	[ "In June 2012, Amazon began the installation of a $52 million investment in cooling its warehouses around the country, a major cost for the company equivalent to 8.2 percent of Amazon's 2011 total earnings. Experts speculated Amazon made such a massive investment either to dampen negative publicity over worker cond...
How long does it take for a large, non-spherical object in space to become spherical?	Assuming the cube is made from the same material that Earth is made of, it would probably not take very long to become spherical. The corners of the cube would in effect be mountains that are many hundreds of km tall, which would collapse due to gravity.	[ "A spherical secondary can achieve higher implosion densities than a cylindrical secondary, because spherical implosion pushes in from all directions toward the same spot. However, in warheads yielding more than one megaton, the diameter of a spherical secondary would be too large for most applications. A cylindric...
Why doesn't China have a large muslim population but southeast Asia does even though China is closer to the middle east?	China does have a thriving Muslim population, though they are in several different groups. Perhaps the most notable are the 维吾尔族 Uyghurs (pronounced like "Wee-ger") in the 新疆维吾尔族自治区, or the Xinjiang Uyghur Autonomous Region (a region some Uyghurs often refer to as Eastern Turkestan). In this region, the largest provin...	[ "Most of the significant population of Muslims in China is a result, not of missionary activity, but of trade links forged between various Muslim Caliphates with various Chinese dynasties over the centuries. In addition, often Chinese rulers would encourage flourishing of Muslim minority communities as buffers agai...
How and when did pepperoni become the default topping for pizza in the U.S.?	We've had to remove a number of posts with people sharing what they like on their pizza instead of pepperoni and/or challenging the OP's assumption. Please, if you want to discuss your favorite pizza, that is for another subreddit. As for the fact that Pepperoni is the default topic, "default" is up for debate, I agre...	[ "Common toppings for pizza in the United States include ground beef, mushrooms, onions, pepperoni, pineapple, garlic, olives, peppers, carrots, tomatoes, spinach, anchovies, chicken, bacon, ham and sausage. Distinct regional types developed in the 20th century, including California, Chicago, Detroit, Greek, New Hav...
One of the main requirements of Islam is prayer, and one of the prayers is at dawn. How did people in the time of the prophet Muhammad wake up for prayer on time, considering there were no alarms at all?	There are basically two answers. One is that, at least according to the Hadith, the call to prayer already existed and would have been called out for the dawn prayer. The second answer is that pre-modern sleep practices were very different than our modern concept of one, approximately eight hour long period of uninterr...	[ "Mohammad initially prayed the tarawih, a special Muslim prayers during the month of Ramadan, in congregation but later discontinued this practice out of fear that Muslims would start to believe the prayers to be mandatory, rather than a sunnah. During his Caliphate Umar reinstated the practice of praying \"tarawih...
how do disinfectants work?	They contain an agent which kills bacteria. In the case of hand-sanitizers, the ingredient is alcohol - specifically, usually, ethanol or isopropanal (there's others too, though). When rubbed onto skin (or surfaces, in the case of other disinfectants) the bacteria are killed.	[ "Disinfectants are antimicrobial agents that are applied to the surface of non-living objects to destroy microorganisms that are living on the objects. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physi...
how did glow in the dark happen? and where did it get its source of energy to glow in the dark?	Around 1669, there was a German alchemist named Hennig Brand. He was in search of gold, and thought that it came from within man. What color is gold? It's a shade of yellow. What else is yellow that everyone is familiar with? Urine. So off went Hennig on a quest to extract gold from pee. He boiled down 5,500 liters of ...	[ "In 1974, the glow was explained by R. J. van Zee and A. U. Khan. A reaction with oxygen takes place at the surface of the solid (or liquid) phosphorus, forming the short-lived molecules HPO and that both emit visible light. The reaction is slow and only very little of the intermediates are required to produce the ...
Theoretically, how far "back in time" could we go and still be able to have a conversation with local inhabitants?	Warning: This is not my area of expertise at all, but since there have been no replies after half an hour, I'll give it a go. First of all, it depends greatly on what language you'd like to speak in, as you acknowledged in your post. It also depends on who you'd like to speak to - peasants? kings? But the general a...	[ "\"In the not-distant future, the sound of Man will invade those unknown depths of space which as yet we cannot even imagine. In his own world there are no places left beyond the reach of his voice. His neighbor is no longer just next door, but anywhere at the end of a wire. And it all began when prehistoric man di...
why are ceiling's spackled or whatever it's called. why aren't they just flat like walls?	I work in new home construction in a mid-Atlantic market. We do smooth ceilings (you are describing textured). In my market textured is about 50% of the multifamily housing market and about 0% of the single family market. From my perspective you do this more to hide imperfections in drywall seams than as a sound dampen...	[ "A ceiling is an overhead interior surface that covers the upper limits of a room. It is not generally considered a structural element, but a finished surface concealing the underside of the roof structure or the floor of a story above. Ceilings can be decorated to taste, and there are many fine examples of frescoe...
Are there any current historical debates/uncertainties between historians in regards to Spartacus?	The main uncertainty about Spartacus is his ethnicity. He is called a Thracian, but Thracian is both an ethnicity and a style of combat in gladiatorial games. Gladiators were organised by their combat style, and by that point in Roman history gladiators were no longer limited to just their cultural combat style, espe...	[ "Spartacus ( \"\"; ; c. 111–71 BC) was a Thracian gladiator who, along with Crixus, Gannicus, Castus, and Oenomaus, was one of the escaped slave leaders in the Third Servile War, a major slave uprising against the Roman Republic. Little is known about Spartacus beyond the events of the war, and surviving historical...
If the y chromosome is human specific what causes the differentiation of male and female apes?	The Y chromosome originally evolved from an autosome which acquired sex-determining characteristics. Apes also have X and Y chromosomes; in fact, many vertebrates do - mice have XY (male) and XX (female), birds have ZZ (male) and ZW (female). Some vertebrates don't have their sex determined in this way. Often, enviro...	[ "Many species have so-called sex chromosomes that determine the gender of each organism. In humans and many other animals, the Y chromosome contains the gene that triggers the development of the specifically male characteristics. In evolution, this chromosome has lost most of its content and also most of its genes,...
why does using a tootbrush how we do not make us sick? it is never sanitised and sit in your bathroom all day.	Soap, your faucet, your tooth brush, the glass you drink water out of, all has bacteria on it. We don't live in a sterile environment and we ourselves are not sterile. You have more bacteria in your mouth, and fungal spores, than on your tooth brush. Having bacteria isn't the problem, it's having a place for bacteria...	[ "BULLET::::- Waterless pet shampoo may help keep a messy butt clean. If frequent baths are necessary, it's advisable to use a shampoo specifically formulated for cats. Their skin pH is significantly different from ours; our soaps, shampoos, and detergents may be too harsh and cause dry skin or brittle fur.\n", "I...
Historiography question: what do you consider determinism/causality?	you cannot assign a causal relationship without direct experimental manipulation. History is a correlative study.	[ "Certain philosophers of science argue that, while causal determinism (in which everything including the brain/mind is subject to the laws of causality) is compatible with minds capable of science, fatalism and predestination is not. These philosophers make the distinction that causal determinism means that each st...
what are the reasons as to why the oil price never return to $1 range since 9/11?	The specifics about why gas prices go up can be better explained by others, but this chart shows gas prices adjusted for inflation: _URL_0_ It seems like the climb started closer to 1999 than 2001, but asking why it hasn't gone back done since then is a great question.	[ "The oil price historically was comparatively low until the 1973 oil crisis and the 1979 energy crisis when it increased more than tenfold during that six-year timeframe. Even though the oil price dropped significantly in the following years, it has never come back to the previous levels. Oil price began to increas...
What happens to electrons in a circuit?	For the purposes of circuits, electricity works a lot like a pneumatic system. With wire there will be electrons in all the places at the same time. If power gets used up, to useful work or to resistance it does so in the form of a 'pressure drop' but the electrons are still around. The actual net movement of the el...	[ "The actual concentration of electrons is typically very dilute, and so (unlike in metals) it is possible to think of the electrons in the conduction band of a semiconductor as a sort of classical ideal gas, where the electrons fly around freely without being subject to the Pauli exclusion principle. In most semico...
how exactly do people avoid taxes using shell companies?	Let's say you own a pretty profitable business in the US but you're tired of paying taxes. First, you make a shell company where there are lax regulations and low taxes. Then you transfer the assets that your US company has to the shell company, in name at least. You continue to use those assets in the US to make money...	[ "There are also shell companies that were created for the purpose of owning assets (including tangibles, such as a real estate for property development, and intangibles, such as royalties or copyrights) and receiving income. The reasons behind creating such a shell company may include protection against litigation ...
pigs are considered fairly intelligent animals. why are people who abhor eating dogs, cats, horses and whales for moral reasons fine with eating pork?	Because pigs rarely have a use outside of their use as food. Sometimes they are bred to hunt for truffles and other fungus/plants, but aside from that, their characteristics make them ideal as a food source. * Grow quickly * Eat anything * Don't require much space * Gain lots of meat in a small amount of time That se...	[ "Pigs are regarded to be highly intelligent social animals. Animal rights groups like PETA argue that this makes their exploitation and suffering in the hands of the factory farming industry especially unethical.\n", "Most Pigs, however, are mute, lacking the ability to form words in either thought or speech. Som...
why stab wounds in movies appear to be deadlier than gunshot wounds (at least in movies)	It's all about what's convenient for the story. Bad guys get shot and they are instantly dead. Good guys get shot and they can run a marathon. There is no consistent logic even within the same movie. As long as it doesn't break the suspension if disbelief, writers and directors do what moves the story in the direction...	[ "The film has developed a cult following due to its gruesome, if primitive, special effects, including some memorably bloody death scenes. One character is eaten from the inside out by the titular monsters, resulting in a gushing fountain of intestinal matter. Another victim is stabbed with a wooden stake, then sho...
how does the susan g komen foundation steal so much money without anybody getting upset about it?	people stop caring after they make their donation. No one ever cares where the money goes after they give it, they just give it to feel good about themselves, not to actually do any real good. It is all about perception, and perception is reality.	[ "The accusations include receiving up to seven-figure sums in contributions to Spinka charities while secretly promising to refund up to 95% of contributors' donations, thus allowing contributors to then illegally claim tax deductions on money they in fact kept. The scheme allegedly saved the participating donors m...
why do people want programming taught in elementary/high schools?	Because it's a skill which has lots of real-world use, and which, like many skills, is easier to teach to children than adults.	[ "The idea of educational programming is in fact much more than just the delivery of instruction modules for children and youth hungry to learn the basics of literacy and mathematics. The concept is much more holistic and concerned about the values, attitudes, and character of the next generation in the Arab World; ...
why do people in the americas greet eachother with one kiss on the cheek while in europe they greet eachother with two kisses on each cheek?	Americans do not, on average, kiss each other on the cheek when meeting. Since the most common is zero, one seems like plenty. In a culture where kissing on the cheek is common, two does not seem like an excess.	[ "While cheek kissing is a common greeting in many cultures, each country has a unique way of kissing. In Russia, Poland, Slovenia, Serbia, Macedonia, Montenegro, the Netherlands, Iran and Egypt it is customary to \"kiss three times, on alternate cheeks\", but kiss twice in Bosnia and Herzegovina. Italians, Hungaria...
is there any difference between getting injections(of vitamins,medicine etc.) directly into your veins or into your muscle(most commonly butt muscle)?	Some things, like vaccines, are best injected into muscles due to the way they are made and engineered to work. Others are injected into veins for quick distribution. Because vaccines do not need to be so rapidly distributed they do not need to directly enter the bloodstream. As to why they did both for you, it could...	[ "Intramuscular injection, often abbreviated IM, is the injection of a substance directly into muscle. In medicine, it is one of several alternative methods for the administration of medications (see route of administration). Muscles have larger and more numerous blood vessels than subcutaneous tissue and injections...
Where does helium in natural gas come from?	Alpha particle decay of naturally occuring radioactive elements, such as Uranium. The alpha particle is a helium nucleus.	[ "All commercial production of helium comes from natural gas. There are two basic types of commercial helium deposits: natural gas produced primarily for the hydrocarbon content, typically containing less than 3 percent helium; and gas with little or no hydrocarbons, produced solely for the helium, which typically m...
why is contact lens solution so friggin' expensive?	It's a sterile product that people are putting in their eyes. Lots of liability if someone gets an infection.	[ "Contact lens solutions often contain preservatives such as benzalkonium chloride and benzyl alcohol. Preservative-free products usually have shorter shelf lives, but are better suited for individuals with an allergy or sensitivity to a preservative. In the past, thiomersal was used as a preservative. In 1989, thio...
how do "non-profit" organizations have some of the highest paying internships / job positions?	The company itself doesn't post a profit, meaning that any money it gets over its budget/operating cost (including employee salaries) must be given away/not used for company benefit. While it may seem counter-intuitive, non-profits do need to maintain competitive pay rates to attract talent necessary to maintain an eff...	[ "Companies in search of interns often find and place students in mostly unpaid internships, for a fee. These companies charge students to assist with research, promising to refund the fee if no internship is found. The programs vary and aim to provide internship placements at reputable companies. Some companies may...
why do elderly people die from simple falls?	> when an identical fall would barely even injure someone younger? Because often it is not an identical fall. A healthy person will likely have the strength, reflexes, balance, and agility to partially recover, and minimize the damage of fall. You put a hand out, aim for something soft, or twist so you land on you...	[ "Falls in older adults are a significant cause of morbidity and mortality and are an important class of preventable injuries. The cause of falling in old age is often multifactorial, and may require a multidisciplinary approach both to treat any injuries sustained and to prevent future falls. Falls include dropping...
how does a on-time pad work?	All codes work by changing some piece of information. Because of the change it is hard to tell what the original information was. For instance if I change some word into "xxr" what was the original word? Well a one time pad is a way of changing information that never repeats any pattern,, that means you can never pre...	[ "All manufacturers mark their electrode pads with an expiration date, and it is important to ensure that the pads are in date. This is usually marked on the outside of the pads. Some models are designed to make this date visible through a 'window', although others will require the opening of the case to find the da...
why airline frequent flyer programs have been made so difficult?	Because the airlines benefit from the impression that they have the program, but do not benefit from people using it.	[ "Frequent-flyer programs have been receiving scrutiny because of the prevalence and rapid growth of air travel, in terms of both the frequency that individuals fly and the tendency toward longer distance travel. There have also been calls for an end to frequent-flyer programs. An increase in the number of hypermobi...
Can a person sense light if he/she is asleep?	You can sense light through your eyelids while closed, although you may not be consciously aware of it. Light signals your body to stop producing (or secreting) melatonin, enabling you to wake up more readily. This is how the lamps that use simulated sunlight help you gently wake up.	[ "Another study has indicated that sleeping with the light on may protect the eyes of diabetics from retinopathy, a condition that can lead to blindness. However, the initial study is still inconclusive.\n", "A University of Pennsylvania study indicated that sleeping with the light on or with a nightlight was asso...
how do telescopes that capture images very far away (hundreds of light years) get a good sharp shot when you know that the earth rotates slowly	The telescopes are mounted on motors that move it to compensate for the rotation of the earth. This is true for even moderately expensive personal telescopes.	[ "Imaging of dim celestial targets, usually deep sky objects, requires exposure times of many minutes, particularly when narrowband images are being taken. In order for the resulting image to maintain usable clarity and sharpness during these exposures, the target must be held at the same position within the telesco...
FAQ Friday: Ask your questions about the Ebola epidemic here!	For this outbreak the reported fatality rate seems to be around 50-60% meaning that a lot of people actually have survived this nightmare. My question is about what shape these people are in when they are no longer testing positive for the virus? It seems some make a full recovery, but are there irreversible damage don...	[ "On 11 May 2017, the DRC Ministry of Public Health notified the WHO about an outbreak of Ebola. Four people died, and four people survived; five of these eight cases were laboratory-confirmed. A total of 583 contacts were monitored. On 2 July 2017, the WHO declared the end of the outbreak.\n", "On 8 August 2014, ...
I few Warp Drive questions.	IIRC, there would be no significant time dilation using an Alcubierre metric because it is space itself moving. Inside the bubble the object has locally zero velocity, but I could be wrong. Therefore I think that only four weeks would pass. It also would not create any G-force since the spaceship is not being accelerat...	[ "One supervisor, Jim Burton of Blue Ridge, tried to be serious. He reminded the board that \"warp\" had other meanings. \"You need to think about it before you vote on it\" he warned. \"Would you prefer 'Beam me up, Scotty?'\", the board's chairman replied. In the end the vote was unanimous. \"What more uplifting m...
i've been diagnosed with tenitus (loud ringing in the ears) what's making my brain generate that noise?	You didn't ask the person who diagnosed you? Also, it's tinnitus.	[ "BULLET::::- For sensorineural hearing loss, the lack of input coming from the damaged sensory apparatus can cause \"ghost beeps\" or ringing/tinnitus as the brain attempts to interpret the now missing sensory data. The frequency and the volume of the noise can increase according to one's physical condition (stress...
Why did Russian life expectancy drop massively in 1993?	There was a [massive famine](_URL_1_). When Boris Yeltsin liberalized the economy in 1992, speculators came in and basically broke the Russian wholesale markets, causing massive price spikes. Inflation rose 2,500% in 1992. Previously, the USSR had price controls for most foods, meat, dairy, wheat, etc. After prices w...	[ "The life expectancy was about 70 in 1986, prior to the transition-induced disruption of the healthcare system. The turmoil in the early 1990s caused life expectancy in Russia to steadily decrease while it was steadily increasing in the rest of the world. Recently however, Russian life expectancy has again begun to...
What was the Communist Party of Korea like during the Japanese occupation, and how did Kim Il-Sung seize complete control over it after the establishment of North Korea?	About a year ago i answered a [similar question](_URL_0_).	[ "The party became the Korean section of the Communist International at the 6th congress of the international in August–September 1928. But after only a few months as the Korean Comintern section, the perpetual feuds between rival factions that had plagued the party from its foundation led the Comintern to disband t...
musical intervals (with emphasis on guitar)	The simplest way to describe an interval is that it's the number of semitones between two notes. There are 12 semitones in an octave and each one has a special name. Here's what that would look like using a C chromatic scale: * 12. Octave (C) * 11. Major 7th (B) * 10. Minor 7th (Bb) * 9. Major 6th (A) * 8. Minor 6th (...	[ "For commonly encountered harmonic or melodic intervals between pairs of notes in contemporary Western music theory, without consideration of the way in which they are tuned, see Interval (music) § Main intervals.\n", "In atonal or musical set theory, there are numerous types of intervals, the first being the ord...
when people that are lactose intolerant eat or drink dairy, what exactly is happening inside their stomach when diarrhea occurs?	So lactose intolerance happens when someone's body does not create enough [lactase](_URL_1_). Lactase is an [enzyme](_URL_4_) that would break down [lactose](_URL_3_), the unique sugar component of milk, into sugar that our bodies can use for energy. Lactose intolerant people have issues with breaking down the lactose ...	[ "Lactose intolerance is a condition in which people have symptoms due to the decreased ability to digest lactose, a sugar found in dairy products. Those affected vary in the amount of lactose they can tolerate before symptoms develop. Symptoms may include abdominal pain, bloating, diarrhea, gas, and nausea. These s...
is modern industry able to make cheap paper not from wood?	The question is though... What's wrong with paper from wood? The paper industry plants as many trees as they cut down nowadays, to make sure they will be able to still make paper in the future. It's not like massive forests are disappearing because of paper.	[ "Paper manufacturing is highly competitive, with historically tight margins and small operating profits. As a result, the raw materials used to make paper have to be very cost effective, using cheap, scalable renewable resources, coupled with relatively inexpensive ways to deliver large quantities to market. Until ...
how hard would it be to just unplug all of n. korea from the internet?	Not that hard but China's assistance would be a prerequisite. But that goes against all ethical reasoning in that the internet should be available to all. Even if you did, the chances are that the Sony hack was conducted from outside N. Korea.	[ "Internet access is not generally available in North Korea. Only some high-level officials are allowed to access the global internet. In most universities, a small number of strictly monitored computers are provided. Other citizens may get access only to the country's national intranet, called Kwangmyong. Foreigner...
why do analog tv broadcasts still exist in the us?	Low Power TV stations are still allowed to transmit in analog in the United States. The current deadline for them to convert to digital is Sept 1, 2015. _URL_0_	[ "On June 12, 2009, sporadic E allowed some television viewers in the eastern United States to see VHF analog TV stations from other states at great distances, in places and on TV channels where local stations had already done their permanent analog shutdown on the final day of the DTV transition in the United State...
Do modern high heels worn by women and Chinese foot binding have any historical similarities in the way they developed?	No, not really. In western Europe, high heels date back to the 17th century for both men and women, and were worn by fashionable men and women into the 18th century. There is no clear origin, only speculation and apocryphal stories (so in that sense, there is a connection between foot-binding and high heels), such a...	[ "The status of women in China was also low largely due to the custom of foot binding. About 45% of Chinese women had bound feet in the 19th century. For the upper classes, it was almost 100%. In 1912, the Chinese government ordered the cessation of foot-binding. Foot-binding involved alteration of the bone structur...
Photon Energy Levels, what is different about Radio wave photons vs Gamma wave photons?	> but what exactly is that extra energy coming from? Whatever is producing the photon.	[ "In astronomy, higher energy gamma and X-rays are defined by energy, since the processes that produce them may be uncertain and photon energy, not origin, determines the required astronomical detectors needed. High-energy photons occur in nature that are known to be produced by processes other than nuclear decay bu...
Partial pressure of O2/CO2 in blood versus the actual concentrations of O2/CO2 exchanged; why the huge difference?	Well, you partially answered your own question; oxygen pressure increases dramatically due to hemoglobin binding. Some oxygen is directly dissolved into the blood, but this amount is almost negligible compared to that bound to hemoglobin. CO2, on the other hand, is mostly present in the blood in the form of bicarbonate...	[ "Because A–a gradient is approximated as: (150 − 5/4(pCO)) – Pa at sea level and on room air (0.21x(760-47) = 149.7 mmHg for the alveolar oxygen partial pressure, after accounting for the water vapor), the direct mathematical cause of a large value is that the blood has a low P, a low P, or both. CO2 is very easily...
how do single cylinder engines work?	All engines have a flywheel of some sort to smooth out their power output. In a four-stroke engine with less than four cylinders or a two-stroke engine with only one, the flywheel's inertia is the only thing turning the engine when there isn't a power stroke occurring in one of the cylinders.	[ "A single-acting cylinder in a reciprocating engine is a cylinder in which the working fluid acts on one side of the piston only. A single-acting cylinder relies on the load, springs, other cylinders, or the momentum of a flywheel, to push the piston back in the other direction. Single-acting cylinders are found in...
Did the Roman economy suffer through "Bust and Boom" cycles?	This is a very interesting question that I would like answered (as well as the spam deleted). Did the slave economy more or less function in a stable pattern of growth fueled by conquests until the decline brought about stagnation? Or were there boom and bust cycles as in the capitalist system? Any experts care to weig...	[ "Whereas the Roman Economy was able to thrive in the first few centuries AD thanks to its advanced trade and commerce, the boom was tempered as their ways of conducting business changed drastically. Due to Augustus and the aristocracy holding the large majority of land and wealth in Rome, trade and commerce in the ...
why at rock concerts and gigs is it always impossible to get the sound of the vocals to sound clear over the rest of the band?	It's all about the sound engineer and the equipment they use. A shitty engineer won't get it right but the good ones will. Also depends where you are sitting/standing.	[ "The performances are improvised: they can be quite loud, lengthy, dramatic, soothing, eerie, and possibly alarming. Because Soundscapes are often held as part of a rock concert, they can prove somewhat taxing on an unprepared audience.\n", "“We haven’t yet done any playback vocals at any of our live concerts, an...
why should we care that we created nuclear fusion?	As you might know, most of our energy comes from unsustainable and highly polluting fossil fuels. Wind, solar, hydro, and geothermal sources can't create enough energy to replace them. Nuclear fission power plants produce highly radioactive waste. So we need some large source of energy that has a readily available fuel...	[ "As a source of power, nuclear fusion is expected to have several theoretical advantages over fission. These include reduced radioactivity in operation and little high-level nuclear waste, ample fuel supplies, and increased safety. However, achieving the necessary temperature/pressure/duration combination has prove...
how is pre-made frozen food at the grocery store less healthy than food you make yourself and then refrigerate?	It's not necessarily less healthy, depending on what you make at home. But, generally speaking, pre-made foods are often made with more salt, sugar, and/or fat than people usually use when they make their own food.	[ "Frozen products do not require any added preservatives because microorganisms do not grow when the temperature of the food is below , which is sufficient on its own in preventing food spoilage. Long-term preservation of food may call for food storage at even lower temperatures. Carboxymethylcellulose (CMC), a tast...
What do social and political sciences say about when we will get to dealing with global climate change?	You might want to have a mod change the the category flag for this question, as it's pretty far afield of the physical science of climate change. Poli sci, economics, or another social science might be more appropriate. In the mean time, I can toss you some leads that I've stumbled across until someone else can do be...	[ "Scientists are also increasingly interested in understanding the nature of past and present changes to Earth's climate—whether abrupt or gradual, regional or global—and the potential for human activities to influence the natural system.\n", "It has been evident that climate change has become a main focus in the ...
how do satellites orbiting the earth get their orbits assigned to them, and how do they not hit into each other?	Spent the last 25 years in the space business. It depends on the orbit. Geostationary communication satellites have their slots (e.g. longitude) assigned by the International Telecommunications Union (ITU) _URL_3_. If I want to put up a new comm sat I have to file with my national regulatory agency (for the US this is...	[ "Inner satellites are all tidally locked, that is, their orbit is synchronous with their rotation so that they only show one face toward their parent planet. Their long axes are typically aligned to point towards their planet.\n", "A geocentric orbit or Earth orbit involves any object orbiting Planet Earth, such ...
what's the difference between allegory and metaphor?	The short version: An allegory is a type of metaphor. Longer version: A metaphor is a figure of speech that substitutes in a non-literal alternative to make an interesting point. Saying that "his heart is a shattered vase" is a metaphor, because a heart is definitely not a balloon, but it gives you an interesting ...	[ "A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two ideas. Metaphors are often compared to other types of figurative language, such as antithesis, hyperbole, metonymy and si...
Biologists: Snake repellent?	Cats will reduce the rodent population. I live in Rural California and we have a lot of Rattlesnakes, we have cats to bring down the rodent population, lessening the snakes. We still find them, but when we do they meet Mr. Shovel.	[ "Francis Crick has commented on potential limitations of Occam's razor in biology. He advances the argument that because biological systems are the products of (an ongoing) natural selection, the mechanisms are not necessarily optimal in an obvious sense. He cautions: \"While Ockham's razor is a useful tool in the ...
why do ants drop other ants off ledges?	Not sure if the carried ant was alive, but as i'm aware ants will remove ant-corpses from the vicinity of their colony so disease doesn't spread and doesn't attract predators. Perhaps that's why?	[ "Other species of ants such as \"Conomyrma biocolor\" has been known to drop stones around the entrances of \"M. mexicanus\" nests. This behavior usually happens if the two species have colony entrances within 3 meters of each other. The two species have similar foraging times and food sources which creates competi...
why have we developed to sometimes hold our breath during tense situations?	I'm going to do my best here. Deep breathing activates certain neurons in the brain that tell your body to relax. Holding your breath heightens that response a little. It also provides proprioceptive input, meaning it activates your muscles through that feeling of tension in your chest/abdomin. Similar to swaddling a b...	[ "BULLET::::- Many took part in sports activities during teens and twenties some which required breath-holding which included many types of sports such as swimming and even weight lifting. They find a certain level of comfort in breath-holding, and often do it while awake.\n", "Ventilation is normally unconscious ...
What were the reactions and perceptions of new allied technology by the axis?	It's worth noting that most of the major Allied technologies we associate with the European war were secret (e.g. the code-breaking computers) or subtle. The most important two were probably radar and the proximity fuze. Neither of them have a "Wunderwaffen" quality to them. The Germans had their own proximity fuzes (t...	[ "The message of complacency is transferred to other theatres, such as the Russian, Pacific and later invasion of Germany, reminding the audience that despite recent victories, the Axis could still strike.\n", "With the signing of the Tripartite Pact on September 27, 1940, creating the Axis of Germany, Japan, and ...
why do surgeons need to wash their hands for an extend period of time when normal sanitizer already kill 99.9% of all bacteria	From what I understand, sanitizer kills the organisms, but those dead "corpses" are all still there. The body reacts the same way to a dead virus as it does to a live one. Washing probably cleans all that dead stuff off too.	[ "Improving patient hand washing has also been shown to reduce the rate of nosocomial infection. Patients who are bed-bound often do not have as much access to clean their hands at mealtimes or after touching surfaces or handling waste such as tissues. By reinforcing the importance of handwashing and providing santi...
why you only get caught for illegally downloading some things, but not others?	Pure luck. You just happened to be downloading the file at a time when the copyright police (basically a bunch of people at the big media companies) were tracking you.	[ "Christian Barry believes that understanding illegal downloading as equivalent to common theft is problematic, because clear and morally relevant differences can be shown \"between stealing someone’s handbag and illegally downloading a television series\". On the other hand, he thinks consumers should try to respec...
Why didn't the turkish people attempt to reclaim any lost territory from the first world war?	It's important to note that, at this time, the lands they lost with the exception of Saudi Arabia were all British and French colonies who were at the height of their power. Taking back Iraq or Syria or Palestine didn't mean going to war with some two-bit monarch or collapsing empire, it meant taking them from some of...	[ "Everything that was left behind was later looted or destroyed. Turkey's surrender at the end of World War I led to the restoration of Ani to Armenian control, but a resumed offensive against the Armenian Republic in 1920 resulted in Turkey's recapture of Ani. In 1921 the signing of the Treaty of Kars formalized th...
what makes computer hacking difficult, and not something a computer itself does?	Well in some cases, it does. But that's another story. Consider what computers do: very simple tasks, very fast. They don't (usually) screw up. Now hacking consists, fundamentally, of finding cases where people told the computer to do the wrong thing. At a very basic level, this is a deviation from expected behavio...	[ "This approach has its pitfalls. If the location specified is incorrect, this will cause the computer to write the data to some other part of the program. The results of an error like this are unpredictable. In some cases, the incorrect data might overwrite memory used by the operating system. Computer crackers can...
why do some gifs load fine on the reddit app but others won't?	I don't know why either. Happens to maybe 20% of gifs. There is an easy fix though. If it doesn't load, click the word 'imgur' just above the post title. Works a treat.	[ "To mark the 30th anniversary of the GIF, Facebook has introduced a new feature enabling users to add GIFs to comments. The eagerly-awaited feature can be accessed using the GIF button located beside the emoji picker. Users can choose from the available GIFs sourced from Facebook's GIF partners, but cannot upload o...
How come some farts blow over in seconds, whilst others hang in the air for ages?	Best fucking question ever asked I dunno :/	[ "(I'm in the ox's tummy/ Where it doesn't snow or rain./ When the ox farts/ Patufet will get out). After a while they hear Patufet's little voice and his mother feeds the ox with herbs that make it fart faster.\n", "The Gas We Pass: The Story of Farts (おなら \"Onara\") is a children's book written by Shinta Chō ()....
What did the soldiers of the hundred years war eat as rations?	Soldiers in the Hundred Years War did not receive rations as such. Commanders were supposed to provide food for their men (whether by taking it with them or by foraging/pillaging for it), but there was no system comparable to the Royal Navy's daily allotments of particular foods. Food might be provided by royal purveya...	[ "When on campaign, soldiers would normally be supplied with an allowance of bread, meat, oatmeal or rice and either beer or rum to wash it down with. A typical daily allowance for a group of up to six men consisted of () of bread or flour, () of beef, () of rice or oatmeal and () of rum. A soldier in camp could exp...
baby boomers are adamant that they had it far worse than proceeding generations, how is the opposite actually true?	Let's imagine this. You're a new generation of cavemen and you have the ability to use wheeled carts to carry items. The generation before you complains on how the new generation has it "easy" compared to them where they had to carry every item. Although yes, the technological advancements weren't there, a new set of i...	[ "This population is sometimes referred to as Generation Jones, and less commonly as Tweeners. These cuspers were not as financially successful as older Baby Boomers. They experienced a recession like many Generation Xers but had a much more difficult time finding jobs than Generation X did. While they learned to be...
why do some things only taste good after a few tries?	Your body automatically rejects new bitter flavors, as many poisons are bitter. But once you have tasted them several times and suffered zero ill effects, your nervous system (basically your brain) starts to adjust.	[ "If the flavor has been encountered before the subject becomes ill, the effect will not be as strong or will not be present. This quality is called latent inhibition. Conditioned taste aversion is often used in laboratories to study gustation and learning in rats.\n", "Conditioned taste aversion occurs when an an...
why do people remember car accidents or anything similar in slow motion?	The brain's perceptual ability can have a very wide or very narrow focus depending on the circumstances. Normally you are taking in sights, sounds, physical sensation, scents, etc, in a more or less balanced manner. At the first sight of danger, the brain can essentially turn off the perception of everything but the vi...	[ "Do you remember the worst thing that has happened to you? What about the best? At what frequency are you able to recall memories that are negative in comparison to those that are positive? Does it seem like negative information is remembered with more ease and clarity than positive information? Why is it easier to...
Would a bottle of wine chill faster opened or unopened?	I don't think it'll make a significant difference either way. The neck is such a small surface area for heat to flow through. Circulating chilled water around the bottle is the way to do it quickly.	[ "Even if the temperatures do not reach extremes, temperature variation alone can also damage bottled wine through oxidation. All corks allow some leakage of air (hence old wines become increasingly oxidized), and temperature fluctuations will vary the pressure differential between the inside and outside of the bott...
where republicans have gotten the idea that obama is a "socialist", and why socialism is seen as such a threat to republicans.	The whole basis of the republican party is smaller government, socialism is more government, thus seen as a "threat" to republican ideals at the very core.	[ "Following Obama's election, many on the political right began to allege that his administration's policies were \"socialistic\", a claim rejected by the DSA and the Obama administration alike. The widespread use of the word \"socialism\" as a political epithet against the Obama administration by its opponents caus...
why emergency vehicle (police/fire/ambulance) sirens sometimes sound like the driver is repeatedly pushing the siren button causing the pattern to constantly restart, rather than just keeping the siren on?	Modern emergency vehicle sirens, typically made by federal or Whelen The standard modes are usually "wail" and "yelp" which are the two typical police sirens. Then there is usually a button for an airhorn and a manual burst siren. The manual burst siren is what they use to alert you to a traffic stop if you don't n...	[ "Some emergency vehicle operators occasionally turn off their sirens when on side streets or when there are no cars on the road so as not to disturb residents; however, there is seldom a mandate for responders to do so. The driver will then turn on the sirens before proceeding through intersections or when travelin...
why crt tv's have that line going through them when recorded by a camera	CRTS work by an electron beam scanning down the screen line by line hitting phosphoros dots and lighting them up. It does this 50 times a second. At the same time a camera is effectively doing the reverse, it is sampling it's light sensor line by line, 50 times a second. The problem is that the scan rates are rarely i...	[ "Although a CRO allows one to view a signal, in its basic form it has no means of recording that signal on paper for the purpose of documentation. Therefore, special oscilloscope cameras were developed to photograph the screen directly. Early cameras used roll or plate film, while in the 1970s Polaroid instant came...
why can some animals go weeks without eating, but humans need food on a daily basis?	Animals that don't eat as often tend to eat much more at each meal. For example, wolves eat only a couple of times a week, if that, but during each meal session they eat somewhere around 15% of their body weight in food. If humans ate like that, they would eat ~20-30 pounds of meat in a single meal.	[ "Since the beginning of mankind, food was important simply for the purpose of nourishment. As primates walked the Earth, they solely consumed food for a source of energy as they had to hunt and forage because food was not easily on hand. By early humans fending for themselves, they had figured out that they needed ...
which medieval combat weapon was the most exclusive to use?	You needed a strong, fast warhorse to use a lance. So that was a prestigious weapon of the nobility. Long swords used a lot of metal and would have been expensive. Spears and clubs were the most simple weapons to construct and would have been available to the common foot soldier. The clergy (yeah, they fought in those ...	[ "It is a vexed issue as to what extent specialized arms and armour were used in mêlée tournaments. A further question that might be raised is to what extent the military equipment of knights and their horses in the 12th and 13th centuries was devised to meet the perils and demands of tournaments, rather than warfar...
If most romantic languages descend from Latin, what are the roots of Latin?	I think you'll get a better answer from /r/linguistics, frankly, but the short answer is that it comes from the Italic branch of a (reconstructed) language called Proto-Indo-European. There's a "family tree" [here](_URL_0_).	[ "A large percentage of the lexicon of Romance languages, themselves descended from Vulgar Latin, consists of loanwords (later learned or scholarly borrowings) from Latin. These words can be distinguished by lack of typical sound changes and other transformations found in descended words, or by meanings taken direct...
How territorial are pets about their food?	There's absolutely no way to say without trying it, because it varies from pet to pet. Some won't mind at all, and others, even if they're big softies away from the food dish, will try to kill like the damned. If you want to find out, try it when they're both in chill moods and in a place that is equally theirs.	[ "Behavioural ecologists have argued that food distribution determines whether a species is territorial or not, however, this may be too narrow a perspective. Several other type of resource may be defended including partners, potential mates, offspring, nests or lairs, display areas or leks. Territoriality emerges w...
how is it that vets can treat multiple types of animals with similar training as doctors who only have humans to deal with?	There are some veterinarians who do specialize. They specialize both when it comes to what sort of animals they treat and what sort of problems they treat. There are horse-doctors and Animal dentists for example. Most of them however are more general practitioners. This is possible because the difference between a ca...	[ "Most vets work in clinical settings, treating animals directly. These vets may be involved in a general practice, treating animals of all types; may be specialized in a specific group of animals such as companion animals, livestock, laboratory animals, zoo animals or horses; or may specialize in a narrow medical d...

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