Split (2)

train · 226k rows

question stringlengths 3 301	answer stringlengths 9 26.1k	context list
why aren't hybrid/electric cars such as the prius shaped like sports cars?	Because the aerodynamics of racing cars are not optimized for fuel economy, but downforce to increase traction under cornering. This actually increases drag and hurts fuel economy.	[ "Cars which prioritise handling or straight-line acceleration are called sports cars or performance cars. However the term 'sports car' is also sometimes used specifically for lightweight two-seat cars. Sports/performance cars can either be built on unique platforms or be upgraded versions of regular cars. \n", "...
"Phlegmy" saliva after hard cardio exercise.	It is because your body has to conserve water, so the proteins in your mucus get mixed with less water, making it more viscous. Phlegm loses up during hard exercise mostly because your respiratory system is working very hard, which includes a lot of contractions and dilatations in rapid succession and an increased pre...	[ "It was not until 2011 that a link between severe pain, neuroinflammation and alarm pheromones release in rats was found: real time RT-PCR analysis of rat brain tissues indicated that shocking the footpad of a rat increased its production of proinflammatory cytokines in deep brain structures, namely of IL-1β, heter...
Is it possible there were civilizations 10 or 20 thousands years ago that are lost? Or is it generally accepted fact that the first civilizations started around 5,000 years ago?	Gobekli Tepe in Turkey is a site that appears to have been in use sometime between the 10th and 8th Millenium BCE. It's a fascinating site that may upend some of our prior notions of how civilization developed - but much work needs to be done on the site before we get any real answers. And of course we may never get t...	[ "Civilizations have generally ended in one of two ways; either through being incorporated into another expanding civilization (e.g. As Ancient Egypt was incorporated into Hellenistic Greek, and subsequently Roman civilizations), or by collapse and reversion to a simpler form, as happens in what are called Dark Ages...
I there a maximum strength for a permanent magnet of a given mass?	The maximum "strength" of a permanent magnet is when the magnet is a single [magnetic domain](_URL_0_). You can think of a permanent magnet as a collection of many atom-sized magnets all pointing in generally the same direction. When they are all perfectly aligned, the magnetic field sufficiently far away from the magn...	[ "and then the magnetic strength of that magnet is found to be proportional to the current of each loop (in Ampere), and proportional to the surface of each loop (in square meter), and proportional to the density of current-loops in the material (in units per cubic meter), so the dimension of strength of magnetism o...
Why was Russia so broke in the 1990s?	Two factors led to this the first was following the breakup of the USSR Russia took on all of the debts/contracts the USSR made. The problem with this was that the USSR depended on the economies provided by all of their member states but especially Poland, the Czech and Slovak republics, and the Baltic nations. The los...	[ "The collapse of the Soviet Union, and the breakdown of economic ties which followed, led to a severe economic crisis and catastrophic fall in the standards of living in the 1990s in post-Soviet states and the former Eastern bloc. Even before Russia's financial crisis of 1998, Russia's GDP was half of what it had b...
how does a company know my email address simply by me googling their product?	There are a lot of companies out there that buy, sell, and trade in your personal information. Let's say you bought something from a website that had small print saying, "We only share your data with close business partners," or something. They might sell your name, address, e-mail address, what you purchased, and an...	[ "Direct email involves sending an email solely to communicate a promotional message (for example, a special offer or a product catalog). Companies usually collect a list of customer or prospect email addresses to send direct promotional messages to, or they rent a list of email addresses from service companies. \n"...
what happens to carbon emissions from vehicles travelling through tunnels?	Most don't get filtered. They just have a ventilation system which expels the exhaust and brings in new air from outside.	[ "Air pollution from fossil (and some biofuel) powered vehicles can occur wherever vehicles are used and are of particular concern in congested city street conditions and other low speed circumstances. Emissions include particulate emissions from diesel engines, NO, volatile organic compounds, carbon monoxide and va...
Growing Hopper Crystals?	I'm not sure you can do much better than listen to the people who've already done it. Even research papers might not amount to much more than "this is how we did it". See, growing crystals is a pretty difficult topic. A whole field in itself (there's even a "journal of crystal growth"), because there are just so many...	[ "The edges of hoppered crystals are fully developed, but the interior spaces are not filled in. This results in what appears to be a hollowed out step lattice formation, as if someone had removed interior sections of the individual crystals. In fact, the \"removed\" sections never filled in, because the crystal was...
Hey scientists...why is it, do you think, that animals like my dog and cat, don't seem to respond at all to music....?	This is not a scientific answer but in the absence of a true response... Animals are very accustomed to ignoring human produced sounds: in particular, anything focussed on the human hearing range around 80Hz-8kHz (this includes most musical instruments regular range except cymbals, triangles and some woodwinds). Anim...	[ "Although it was long generally thought that cats were unresponsive to music, recent studies have shown that they do in fact respond to music which has been created with species-specific frequencies. Results suggested that cats do benefit from music therapy when the sounds have been composed to target their auditor...
how do magicians do mind reading tricks?	There isn't a single answer for this. Various effects are done in different ways. For example, if I ask you to think of a number, I could pretend to write it down on a pad of paper. Then I say "what was your number?" and you say "five", I would then use a tiny piece of pencil lead stuck to my thumb to write a 5 on t...	[ "Magicians use distraction techniques to draw the audience's attention away from whichever hand is engaged in sleight of hand. Magicians can accomplish this by encouraging the audience to look elsewhere or by having an assistant do or say something to draw the audience's attention away.\n", "Magicians ask the aud...
When a person urinates, why doesn't their bladder create a vacuum? Or does it?	The bladder [contracts](_URL_0_) because it is made of flexible tissue. There is no void left behind so there is no vacuum to pull air in. The only analogy I can think of off hand is an IV bag. As it dispenses, the walls of the bag collapse around the fluid. It doesn’t pull blood from you nor does it slow dispensing as...	[ "The urinary bladder is a hollow muscular organ in humans and some other animals that collects and stores urine from the kidneys before disposal by urination. In the human the bladder is a hollow muscular, and distensible (or elastic) organ, that sits on the pelvic floor. Urine enters the bladder via the ureters an...
Was always warned to stay away from windows and off/away from electronic devices (television, computer) during a thunderstorm. How valid is this claim, and how dangerous is it really?	Mythbusters tested this. If you have Netflix then you can watch it. It's the episode "Son of a Gun" (s01e11). The phone did allow the current to go through (if the fuse wasn't grounded) and it would have killed someone. They also tested if someone was in the shower "as if they were standing on a drain, and the drain ...	[ "Current advice is that opening windows in advance of a tornado wastes time that could be spent seeking shelter. Also, being near windows is very dangerous during a severe weather event, possibly exposing people to flying glass.\n", "Throughout the Cold War, there was a conflict between the Royal Air Force and th...
Does the sun have wind? Ive been curious if it was possible?	"Solar winds" do exist but they're not "made" of air. It's a term used to describe the stream of charged particles (plasma) released from the surface of the sun, out into space. Solar winds are the cause of the Northern Lights seen on earth as the Earths' magnetic field (which deviates charged particles hitting the Ear...	[ "On March 8, 2013, NASA released an article according to which ion cyclotron waves were identified by its solar probe spacecraft called WIND as the main cause for the heating of the solar wind as it rises from the sun's surface. Before this discovery, it was unclear why the solar wind particles would heat up, inste...
Why does charcoal burn hotter then the wood it is made from?	A large part of the answer is that there is very little water left in charcoal, and so no energy is wasted in turning water from a liquid to a gas. Then the rest of the answer is that charcoal is sort of pre-burnt, meaning a lot of the steps of combustion are already taken care of. A "fire" is actually a complex set o...	[ "The advantage of burning charcoal compared to burning wood is the absence of water and other components. This allows charcoal to burn at higher temperatures, and give off very little smoke (regular wood gives off a good amount of steam, organic volatiles, and unburnt carbon particles — soot — in its smoke).\n", ...
Have there been cultures that primarily associated women with short hair?	Sorry, we don't allow ["example seeking" questions](_URL_1_). It's not that your question was bad; it's that these kinds of questions tend to produce threads that are collections of disjointed, partial, inadequate responses. If you have a question about a specific historical event, period, or person, feel free to rewri...	[ "At most times in most cultures, men have worn their hair in styles that are different from women's. American sociologist Rose Weitz once wrote that the most widespread cultural rule about hair is that women's hair must differ from men's hair. An exception is the men and women living in the Orinoco-Amazon Basin, wh...
Civil War Help!!!	I believe that just naming some sources that would work well for this question would be a violation of this sub's rules about helping with [homework](_URL_0_), because tracking down and selecting sources is clearly a component of the assignment here. So, with sources so overwhelming, we need to figure out some ways to...	[ "The American Civil War saw significant advances in battlefield medicine. The lower mortality rate of injured soldiers led to the sentiment that the United States should provide care for its surviving injured veterans. The city of Waupaca purchased the land and buildings of the defunct Greenwood Park Hotel and dona...
If we want energy efficient homes, why not build them like large vacuum flasks / insulated thermos?	It would be a matter of money. It would cost significantly more to build a house in two layers strong enough to resist a vacuum (would pretty much have to be solid metal for something with the support needs of a house as far as I can think) rather than by just using (relatively) cheap plywood and fiberglass insulation....	[ "An important and cost-effective element of an efficient heating, ventilating, and air conditioning (HVAC) system is a well-insulated building. A more efficient building requires less heat generating or dissipating power, but may require more ventilation capacity to expel polluted indoor air.\n", "The choice of w...
Why is plasma gasification not widely used to combat traditional disposal of garbage in landfills?	Because it's very expensive and energy intensive, while land is cheap and plentiful. If that's the route we wanted to go, a traditional incinerator would accomplish the same thing for most garbage. Plasma gasification is typically used on hazardous material that would otherwise be difficult to store.	[ "Landfill gas cannot be distributed through utility natural gas pipelines unless it is cleaned up to less than 3% , and a few parts per million , because and corrode the pipelines. The presence of will lower the energy level of the gas below requirements for the pipeline. Siloxanes in the gas will form deposits in ...
Why do things need to be given mass?	At first, we might have accepted that particles have mass as a property. But we found out that photons, W^+/- and Z^0 bosons are all in the same family. It just turns out that the photon is massless, while the other two are very massive. When we investigated why that is, we found a mechanism that generates the mass o...	[ "The principle that the mass of a system of particles must be equal to the sum of their rest masses, even though true in classical physics, may be false in special relativity. The reason that rest masses cannot be simply added is that this does not take into account other forms of energy, such as kinetic and potent...
Could an exoplanet orbit two stars at the same time?	Yes, this is called a circumbinary planet and a few have been discovered, such as Kepler-16.	[ "The separation between stars in a binary may range from less than one astronomical unit (AU, the average Earth–Sun distance) to several hundred. In latter instances, the gravitational effects will be negligible on a planet orbiting an otherwise suitable star and habitability potential will not be disrupted unless ...
why does water appear to be white when coming down from a tap really fast or a waterfall?	Those faucet are aerating the water. This spreads it out by putting a bunch of air in between it. Older faucets sometimes don't do this and the water is clear.	[ "Whitewater is formed in a rapid, when a river's gradient increases enough to generate so much turbulence that air is entrained into the water body, that is, it forms a bubbly or aerated and unstable current; the frothy water appears white. The term is also loosely used to refer to less turbulent, but still agitate...
What are the chances that we might receive an Interstellar Message? What equipment do we have in place for monitoring and how do they work?	The SETI project uses the Allen telescope array to look for interstellar radio signals. Typically these things listen in frequency ranges in between two levels that are strongly absorbed by water (18 and 21 cm), which might make this range the ideal band for sending signals that aren't absorbed. It hasn't found anythin...	[ "Projects such as SETI are monitoring the galaxy for electromagnetic interstellar communications from civilizations on other worlds. If there is an advanced extraterrestrial civilization, there is no guarantee that it is transmitting radio communications in the direction of Earth or that this information could be i...
can a country use another country's currency? what would be the consequences?	This actually goes on a lot in South American countries. Their currency is not that stable which means that family savings are shaky. What families do is buy American dollars since dollars usually is stable. In the same way countries can put their money into investments, however to be able to buy large sums of a curr...	[ "A central bank may use another country's currency either directly in a currency union, or indirectly on a currency board. In the latter case, exemplified by the Bulgarian National Bank, Hong Kong and Latvia (until 2014), the local currency is backed at a fixed rate by the central bank's holdings of a foreign curre...
how did practically everyone come to realize that the ground was lava when they were kids?	Well, for one, all it takes is for it to be on a single kid's show. Then it can leap from mind to mind and spread virtually anywhere. But for two, I suppose it helps that "don't touch the ground" is a fairly universal idea that is just rudimentary enough to be commonplace. You factor in that large demographics of this ...	[ "The floor is lava (also known as hot lava) is a game in which players pretend that the floor or ground is made of lava (or any other lethal substance, such as acid or quicksand), and thus must avoid touching the ground, as touching the ground would \"kill\" the player who did so. The players stay off the floor by ...
what is bandwith? why do they cap it?	bandwidth is how much of the internet speed you can use at any one moment in time. like if you are downloading at a peak rate of 10 MB/s. your bandwidth is 10 MBps, if you ever go higher than 10MBps, then that higher # is your peak bandwidth. they cap it so that more people can use the shared connection. for cable ...	[ "Military bands can vary in function and duties based on their specific mission. Bands may perform for a variety of reasons such as special events, military parades, military review, military tattoos, public relations, and troop entertainment. It may also play a role in boosting the \"esprit de corps\" or morale of...
why is there so much bird crap on my car but none on the floor?	Birds see cars (or people) as enemies/threats so they fly over them and drop crap as a defensive measure.	[ "Another hazard that racing pigeons encounter is flying into objects they sometimes cannot see, mostly when flying at high speeds or in darker weather conditions. The most common obstructions are electricity pylons or TV aerials. Pigeon fanciers will often have one of their pigeons return home with wounds or missin...
Were "throne rooms" purely ceremonial, or did kings actually spend hours a day just sitting in one place? Surely there must have been a better way for a king to spend his time.	This isn't about kings necessarily, but for emperors, yes the option was absolutely open to sit in a "throne room" all day, if they wanted. The emperor Claudius was somewhat infamous for this, his general persona was that of a Republican magistrate and he was perhaps the only one of the emperors to really take his Re...	[ "A common misconception is that kings and other ruling princes governed their lands seated on a throne for most of the working day. This may have been true in earlier times, for some rulers who actually presided over their council; yet often, another room was used, but only in peacetime.\n", "A throne room is an ...
Why has nobody come close to Tesla's inventions that were created up to 100 years ago?	While Nikola Tesla was a very smart and accomplished inventor, many of his ideas and inventions simply didn't work out the way he had imagined it. Tesla has gained a reputation as some kind of visionary whose ideas have, for some reason, not been followed up on. But this isn't true. Tesla's ideas have been studied ext...	[ "Tesla obtained around 300 patents worldwide for his inventions. Some of Tesla's patents are not accounted for, and various sources have discovered some that have lain hidden in patent archives. There are a minimum of 278 known patents issued to Tesla in 26 countries. Many of Tesla's patents were in the United Stat...
what will ecstacy, aka mdma, do to my brain and body?	a good grounding. _URL_0_ make sure you test what you eat, don't mix with alcohol, drink sufficient water, eat some 5-htp afterwards to replenish your serotonin.	[ "At high doses, MDMA induces a neuroimmune response which, through several mechanisms, increases the permeability of the blood-brain barrier, thereby making the brain more susceptible to environmental toxins and pathogens. In addition, MDMA has immunosuppressive effects in the peripheral nervous system and pro-infl...
why is there such a common disapproval for homosexuality in religions?	It was a reflection of society. Having children used to be a lot more important that it is now. A man's wealth and station were passed on to his sons, and he needed women to bear those sons. A man who didn't want to marry and have children was letting down his family. A woman who did want to marry and have childr...	[ "Among the religions that originated in India, including Hinduism, Buddhism, Jainism and Sikhism, teachings regarding homosexuality are less clear than among the Abrahamic traditions. Unlike in western religions, homosexuality is rarely discussed. Vasubandhu included homosexuality among sexual practices that were f...
how do subreddits become default ones like r/sports or r/gaming	They get popular enough that admins decide to ruin it by showing it off to the rest of reddit. Like a way to say "See this awesome vibrant place to discuss things? Well, you missed it."	[ "The most popular posts from the site's numerous subreddits are visible on the front page to those who browse the site without an account. By default for those users, the front page will display the subreddit r/popular, featuring top-ranked posts across all of Reddit, excluding not-safe-for-work communities and oth...
(from my 6 year old nephew) if mosquitoes suck blood out, why does your skin puff up?	Our body doesn't like mosquito spit - it thinks it's going to make us sick - so it sends things called antibodies in our blood to go fight it, and that makes that part of the skin swell up. ([More info](_URL_0_)) Edit: [Here's another good answer](_URL_1_), which goes into why the bites itch, if your nephew gets cur...	[ "Prior to and during blood feeding, blood-sucking mosquitoes inject saliva into the bodies of their source(s) of blood. This saliva serves as an anticoagulant; without it the female mosquito's proboscis might become clogged with blood clots. The saliva also is the main route by which mosquito physiology offers pass...
Why is going on your tip-toes easy, when doing a push-up is difficult?	Note that the muscles you use to move your toes are not actually in your toes. They are in your calves, which connect via sinews to your toes. The same is true for your hands, where the muscles are actually in your arms. You can easily verify this by gripping your forearm near your elbow with your other hand, then mov...	[ "One criticism is that because the pointing stick depends on the user's applying pressure, it can cause hand cramps (although this can be partly solved by setting the sensitivity higher and lifting the finger when the pointer is not being moved).\n", "It is an impressive stunt, much akin to finger-tip push ups, a...
Will there ever be a way to define division by zero, similar to how we defined roots of negative numbers with the imaginary element i?	In math, anything is true if you assume it. You might get more than you asked for, though. The structures we talk about addition and multiplication are things called rings. The integers are rings, as are real numbers, complex numbers, rationals, functions, etc. We can ask, what happens if we assume 0 has a multiplicati...	[ "The negative real numbers can be discarded, and infinity introduced, leading to the set [0, ∞], where division by zero can be naturally defined as \"a\"/0 = ∞ for positive \"a\". While this makes division defined in more cases than usual, subtraction is instead left undefined in many cases, because there are no ne...
Common Law is considered so uniquely British that the Spanish term for it literally means "Anglo-Saxon Law." Did anything similar to it exist on the continent before Napoleon largely standardized Western European legal codes?	Hey, You can divide European law into two groups, which you can divide into subgroups: -continental group (germanic circle), (romanic circle), (nordic circle), -common law group (England and Wales - not whole UK (Scotland is abit different) Why did the two groups who started from the same root differentiante ...	[ "In prehistoric Britain, traditional common law was discussed in the vernacular (see Celtic law). The legal language and legal tradition changed with waves of conquerors over the following centuries. Roman Britain (after the conquest beginning in AD 43) followed Roman legal tradition, and its legal language was Lat...
What were important every-village-has-one buildings in the Medieval ages?	Depends on the size of the village, of course. But most decently sized villages (that is to say, not entirely dependent on other villages or cities for the basic buildings) contained at least a church, a townhall and whatever craftsmen were applicable to the region, ranging from food (indeed, a butcher, bakery or, in c...	[ "The most passionate players involved over the years have built two medieval villages with roads, bridges, ditches, houses and inns at the \"Duché de Bicolline\" venue. Construction days are scheduled throughout spring and summer for those building new houses. These houses are built to resemble medieval buildings a...
Did Spartacus receive any moral support from Rome's intellectual class?	If he did, there are no extant records of it. Here is a [pretty good summary](_URL_1_) of the ancient texts that deal with Spartacus's rebellion. It's in English, too, which is nice. I can't recall any others that handle the topic in any detail, though my memory often fails me and someone else might recall others. So s...	[ "Contrary to popular belief, Spartans valued knowledge and education more than the Athenians did. Spartan philosophers include Lycurgus and Chilon of Sparta. Although Athens has been praised as the \"inventor\" of democracy and philosophy, Sparta often has been viewed in popular culture as a society characterized b...
If you isolated two groups of the same species, would they evolve differently?	The answer to this is several different shades of "yes". Even if you put the two groups in precisely identical environments, they will eventually diverge from one another due to the random forces of [genetic drift](_URL_2_) and [mutation](_URL_0_), which will together send the two groups on separate trajectories. This...	[ "Where closely related species coexist in sympatry, it is often a particular challenge to understand how these similar species persist without outcompeting each other. Niche partitioning is one mechanism invoked to explain this. Studies in some species complexes indeed suggest that species divergence went in par wi...
real versus nominal < insert economic term >	It's usually (maybe always?) about inflation. If you got a 5% raise every year, that'd be cool, unless everything cost 25% more every year. In this case your nominal (from the greek for "name" so it's exactly what you get) wage rate increase is 5%, but your real (from the english for "real", so what the overall effec...	[ "\"Value\" or \"economic value\" is the benefit that a consumer derives after using a product or a service. In most cases the benefit is measured in terms of currency (money) and hence the name economic value. It should be noted that economic value is not the same as market price – if a consumer is paying for a pro...
How common was "underage" enlistment during WWII in the U.S.?	How would someone go about getting enlisted underage? Would it require a fake ID or just were there enlistment people who didn't care?	[ "In World War II, the US only allowed men and women 18 years or older to be drafted or enlisted into the armed forces, although 17-year-olds were allowed to enlist with parental consent. Some successfully lied about their age. The youngest member of the United States military was 12-year-old Calvin Graham. He lied ...
What happens to the 0.01% of bacteria that isnt killed by wipes/cleaners? Are they injured or disabled?	Ok, so I work in the industry of antimicrobial testing, and no, it's not a legal disclaimer, we test and see how much of a log reduction a product gets and we literally scrub the shit out of the device or surface or whatever, so no, it's not a CYA claim, it is based on actual FDA or EPA regulated testing on very specif...	[ "Poorly maintained scrubbers have the potential to spread disease-causing bacteria. The problem is a result of inadequate cleaning. For example, the cause of a 2005 outbreak of Legionnaires' disease in Norway was just a few infected scrubbers. The outbreak caused 10 deaths and more than 50 cases of infection.\n", ...
how is it possible to take non-visible wavelengths and convert them into visible wavelengths?	It's often arbitrary and done for illustrative purposes. But..when done really well it's just math. Let's say we can see wavelengths from 1-100 (not true, but...it keeps the example simple) and we can't see things from 100-1000. Things toward 100 are read, things toward 1 are blue and a rainbow in between. So...if ...	[ "Scientists had observed that light traveling through a medium would be absorbed at different wavelengths, depending on the matter-composition of the medium involved. A white light source would emit light at multiple wavelengths over a range of frequencies. A prism could be used to separate a light source into spec...
when i shoot somebody in a video game, is there an actual bullet flying through the air? or is that just added light effects i'm seeing.	It depends on the game or weapon. Some use what's called "hitscan," which is similar to your laser beam example: when the weapon is fired, the bullet is treated as a straight line that appears instantaneously. A hit is registered when that line intersects with the target. Bullets can also be programmed as actual proje...	[ "BULLET::::- First-person shooter (FPS): A variant of the shooting game. In the game, the camera is actually in place of the character's eyes, so that you are playing the game from the character's view, looking down the barrel of a gun.\n", "Though the game is seemingly an orthodox side-scrolling action game, jum...
Question about Relativity on a trip to Alpha Centauri?	edit: Some factors of 4 were changed to 2, since the original formulas were for round-trip times. Everything should be correct now. --- edit 2: Yes, this problem is very much like the classical twin paradox. If we considered the round trip to Alpha Centauri, we would see that the traveling twin certainly ages...	[ "In the 1830s, Thomas Henderson discovered the true distance to Alpha Centauri by analysing his many astrometric mural circle observations. He then realised this system also likely had a high proper motion. In this case, the apparent stellar motion was found using Nicolas Louis de Lacaille's astrometric observation...
Are eyelid muscles flexing when they are open or when they are closed?	Both > Muscles always come in pairs. Moving in either direction always contracts one of the muscles, and moving in the other direction contracts the other one. In fact, contracting is the only thing a muscle can do, so you could not consciously make a movement that requires no muscle contractions. Therefore, both op...	[ "The muscle acts to close the eye, and is the only muscle capable of doing so. Loss of function for any reason results in an inability to close the eye, necessitating eye drops at the minimum to surgical closure of the eye in extreme cases.\n", "When the eyes are closed, the whole orbital opening is covered by th...
why do we have that uncomfortable feeling when sleeping with limbs uncovered or hanging out of the bed?	Evolution. People who didn't get that weird feeling when dangling their limbs from the trees they were sleeping on were killed by cheetahs.	[ "Being bedridden leads to many complications such as loss of muscle strength and endurance. Contractures, osteoporosis from disuse and the degeneration of joints can occur. Being confined to bed can add to the likelihood of developing an increased heart rate, decreased cardiac output, hypotension, and thromboemboli...
why do we worry about the number of times you can write to an ssd?	The basic answer is that RAM and SSDs are different in the way they store data. SSD read/writes are (much) lower than HDD, a cost in exchange for speed (but not as much speed as RAM). The better term you are looking for in regards to SSD/HDD v. RAM permanence is volatility. RAM requires power to retain data, SSD/HDDs...	[ "When an SSD is writing large amounts of data sequentially, the write amplification is equal to one meaning there is no write amplification. The reason is as the data is written, the entire block is filled sequentially with data related to the same file. If the OS determines that file is to be replaced or deleted, ...
the seven osi layers	> I'm taking a [...] class Talk to the professor. Ask questions in class, drop in for office hours, send him emails. If you have one, there might also be a TA or tutoring resources. The big idea is that you should break things up into layers with specific functions if you want to built a computer system without d...	[ "The concept of a seven-layer model was provided by the work of Charles Bachman at Honeywell Information Systems. Various aspects of OSI design evolved from experiences with the ARPANET, NPLNET, EIN, CYCLADES network and the work in IFIP WG6.1. The new design was documented in ISO 7498 and its various addenda. In t...
What are the most interesting cases of civilizations throughout history discovering dinosaur bones, and how did these different civilizations interpret, explain, and react to the discovery?	Welcome! your question is great, but it pains me to tell you that it's actually a really common one. The good news is that there are plenty of responses all ready for you to check out! /u/1Tw03Four recently did a great round-up of previous posts in this one: [Did ancient societies discover dinosaur bones? Is there any...	[ "The site where the bones were found was largely untouched by paleontologists until around 1990, when excavations restarted. Remains of other dinosaurs, fish, turtles, and plants have also been found, including teeth belonging to a member of the Tyrannosauroidea. Other parts of \"H. missouriensis\", including denta...
Are there any texts, especially novels, that were considered "trashy" in their time, but that have come to be regarded as great literature?	Perhaps the novels of the Brontë sisters would qualify. Reviews were often mixed, always recognizing how popular and enjoyable the stories were, but often deploring the subject matter. Also, as novels concerned with women and particularly beloved by women, they were considered to be in a lesser category, like children'...	[ "Sometimes called \"books never written\" or \"world's greatest books\", these are jokes which consist of fictitious book titles with authors' names that contain a pun relating to the title. Perhaps the best-known example is: \"\"Tragedy on the Cliff\" by Eileen Dover\", which according to one source was devised by...
Why do rockets not burn up while taking off?	Rockets start in the thickest part of the atmosphere at a Relative velocity of 0, they accelerate up through the atmosphere only reaching orbital velocities well into the upper atmosphere. When reentering the atmosphere they need to slow down against thickening air which generates heat through the extreme compression ...	[ "At any point during these phases, the rocket is extremely vulnerable to explosions. If the rocket is successfully attacked by an enemy team it will explode, burning all the fuel and all the Multiwinians inside, and resetting the rocket to its starting point.\n", "The rocket was not flown as it suffered an engine...
Why is it that Greek Mythology has held up so well?	Let's agree for sake of argument that all cultures have equally impressive bodies of oral tradition that include stories about the origins of things and about the conduct of powerful supernatural beings and heroes. I think that's a fair statement, but it is difficult to evaluate a subjective term such as "equally impre...	[ "Greek mythology has had an extensive influence on the culture, arts, and literature of Western civilization and remains part of Western heritage and language. Poets and artists from ancient times to the present have derived inspiration from Greek mythology and have discovered contemporary significance and relevanc...
does the color green mean (positive/gain/go/good) and red indicate (negative/loss/stop/bad) in all countries, why?	Blood is red. The sight of blood excites us one way or another. Vegetation is green. Vegetation means food/water, shelter. We already have a previous biological predisposition to relate one color to alertness and the other for calmness.	[ "Some have attributed particular values to the colours, and a common interpretation is that the green represents the country's plains and the hills; white, the snow-capped Alps; and red, blood spilt in the Wars of Italian Independence and Unification. A more religious interpretation is that the green represents hop...
why is longitude measured in non-parallel lines coming from the poles instead of in parallel circles emanating from the prime meridian and idl?	One of these ways is really easy and convenient for plotting a map and navigating. The other is really, really, really annoying. If you plotted the parallel circles on a flat map, you would get two sets of either concentric ellipses or circles depending on the projection you use, and you couldn't keep your East/West co...	[ "The geographic coordinates of the South Pole are usually given simply as 90°S, since its longitude is geometrically undefined and irrelevant. When a longitude is desired, it may be given as At the South Pole, all directions face north. For this reason, directions at the Pole are given relative to \"grid north\", w...
why is it that teeth come in symmetrical pairs but aren't all the same shape?	They serve different purposes. Herbivores such as cattle or deer or elephants have relatively congruous teeth because their teeth only have one job, crushing leaves and roots and other plant matter. Carnivores like cats and wolves and sharks have relatively congrous teeth because their teeth only have one job, tear a...	[ "The crown of the tooth, which is influenced by the shape of the inner enamel epithelium, also takes shape during this stage. Throughout the mouth, all teeth undergo this same process; it is still uncertain why teeth form various crown shapes—for instance, incisors versus canines. There are two dominant hypotheses....
Will humans eventually evolve to lose our appendix or one kidney?	That's almost impossible to know. Evolution doesn't have a 'plan', of course - and the selection pressures of losing a kidney or appendix are only slight at best. I would expect there to even be a pressure toward the preservation of both our kidneys - having two comes in handy. Since there are countless other factors ...	[ "Recently ... improved understanding of gut immunity has merged with current thinking in biological and medical science, pointing to an apparent function of the mammalian cecal appendix as a safe-house for symbiotic gut microbes, preserving the flora during times of gastrointestinal infection in societies without m...
how does relativity explain gravity for objects 'at rest'?	Remember in general relativity objects exist in a 4D space-time. That 4D space is distorted by the presence of mass. When objects are spatially at rest they are still moving in the time coordinate. Likewise, while moving in space the are moving through space and time coordinates. The presence of mass distorts the path...	[ "A key feature of general relativity is that it describes gravity not as a conventional force like electromagnetism, but as a change in the geometry of spacetime that results from the presence of matter or energy.\n", "Einstein generalized relativity to frames of reference that were non-inertial. He achieved this...
Do humans need to eat proteins specifically, or is it only the amino acids and peptides that are required?	It's the amino acids. We don't really even break down the proteins for fuel; that's the amino acids, too. The proteins you eat (generally) never make it out of your gut tract except as amino acids or very small peptides.	[ "Proteins are chains of amino acids. Nine of these proteinogenic amino acids are considered essential for humans because they cannot be produced from other compounds by the human body and so must be taken in as food. Recommended intakes, expressed as milligrams per kilogram of body weight per day, have been establi...
why do words we've known our whole lives occasionally look and sound really awkward to us?	It's actually a psychological phenomena called Jamais Vu, the opposite of Deja vu, and it's the process of something recognizable becoming unfamiliar with repeated use, such as if you say one word over and over, it will eventually just become sounds to your brain and lose its meaning.	[ "\"...our common stock of words embodies all the distinctions men have found worth drawing, and the connections they have found worth marking, in the lifetime of many generations: these surely are likely to be more numerous, more sound, since they have stood up to the long test of survival of the fittest, and more ...
can you turn electricity into a liquid? or other state of matter	Electricity is the name we use for a set of varied phenomena involving the transport of electromagnetic charge. It isn't matter, and so it doesn't make sense to ask about changing its state of matter. As an analogy, you can't turn electricity into a liquid any more than you can turn the emotion of happiness into matter...	[ "A liquid dielectric is a dielectric material in liquid state. Its main purpose is to prevent or rapidly quench electric discharges. Dielectric liquids are used as electrical insulators in high voltage applications, e.g. transformers, capacitors, high voltage cables, and switchgear (namely high voltage switchgear)....
If someone could conceivably have a fraction with any number as the denominator, does this mean there are infinite numbers between 1 and 2?	If someone could conceivably have a fraction with any number as the denominator, does this mean there are infinite numbers between 1 and 2?: yes. If so, would this imply that infinity has an end?: no.	[ "Fractional numbers are supported on most programming languages as floating-point numbers or fixed-point numbers. However, such representations typically restrict the denominator to a power of two. Most decimal fractions (or most fractions in general) cannot be represented exactly as a fraction with a denominator t...
how xl ink cartridges are the same size but have twice as much ink?	This is an easy one. Normal cartridges are a lot of dead space. XL ones are also a lot of dead space. Just less of it.	[ "All types of compatible ink cartridges are different and vary from supplier to supplier. This is due to the type of ink in the printer, the chips (or no chip) on the cartridge and the actual manufacture of the cartridge itself.\n", "They can also be used to create gelatin silver-based prints from digital files. ...
the benefits of nfc payments such as apple pay, google wallet	Advantage: your NFC device or card never leaves your hands. Almost zero chance of theft or duplication. Another layer of security, if you fully trust Google and Apple, is that the merchant has no access to your credit/debit/bank account info. Annoying, though: take phone out, unlock it, (in my case: activate app and...	[ "On September 9, 2014, Apple announced support for NFC-powered transactions as part of Apple Pay. With the introduction of iOS 11, Apple devices allow third-party developers to read data from NFC tags.\n", "With the launch of mobile payment particularly Android Pay and Apple Pay both in 2015, it is expected that ...
why less than one of an object is plural, like .7 lbs (point seven pounds)	Rather than say that as 'point seven pounds,' it would be more correct to read that as 'seven-tenths of a pound.'	[ "Because at any given point on Earth the weight of an object is proportional to its mass, the mass of an object in kilograms is usually measured by comparing its weight to the weight of a standard mass, whose mass is known in kilograms, using a device called a weighing scale. The ratio of the force of gravity on th...
The terminology of sexual violence in late medieval and early modern Europe	Consent absolutely was the definitive factor, then as now. The big, big difference lies in what "consent" means. Even just in the last decade, we've shifted from a No Means No to a Yes Means Yes paradigm--meaning that today, silence from fear, ambivalence, or chemical substances can't be reasonably taken to mean cons...	[ "Medieval Europe in the fourteenth century had already experienced widespread social violence, and even acts then punishable by death such as rape and murder were demonstrably far more common (especially relative to the population), compared to modern times.\n", "Sexual violence can be traced back to the Greeks a...
how do we create needles that are small enough to insert material into individual cells?	You get a bit of thin glass cylinder, heat one end up and pull. You'll stretch it creating a very thin pipette end.	[ "In 2005 the Research Institute for Cell Engineering at Japan's National Institute of Advanced Industrial Science and Technology (AIST) and Tokyo University of Agriculture and Technology used nanoneedles controlled by an atomic force microscope (AFM) to penetrate the nucleus of living cells and insert molecules of ...
The death of a star - does the star's core run out of fuel all at once?	The exact mechanic can differ quite a bit depending on the star's mass, however the key point is that the core does not collapse exactly when the star runs out of fuel, but when the fusion occurring in the core is no longer enough to counter the star's gravity. Once this occurs there are different supernovae that may ...	[ "At what is called the death of the star (when a star has burned out its fuel supply), it will undergo a contraction that can be halted only if it reaches a new state of equilibrium. Depending on the mass during its lifetime, these stellar remnants can take one of three forms:\n", "When a main-sequence star has c...
how do russian bots or "agents" work?	Here's the basic idea. 1) A programmer makes a bot. It is designed to accept an input and generate hundreds of thousands of outputs. 2) The programmer copies his bot and gives it to the various Agents who are going to use it. There might only by 8 agents, but thats 8x the outputs. 3) If the bot is really sophisti...	[ "In video games, a bot is a type of AI expert system software that plays a video game in the place of a human. Bots are used in a variety of video game genres for a variety of tasks: a bot written for a first-person shooter (FPS) works very differently from one written for a massively multiplayer online role-playin...
Are hormones digestable?	Yes, they will be digested, but that is not why we won't see an effect in humans. > People are freaking out about hormones in the milk \ meat, but I wonder- won't most of the hormones like Progesterone be broken down or damaged, and won't affect the body anymore? Most hormones from animals are different enough that ...	[ "Hormone secretion may occur in many tissues. Endocrine glands are the cardinal example, but specialized cells in various other organs also secrete hormones. Hormone secretion occurs in response to specific biochemical signals from a wide range of regulatory systems. For instance, serum calcium concentration affect...
The Kurds were split apart after the fall of the Ottoman Empire after WWI. How did the Kurds feel about this and is their separate "autonomy" enough to keep them satisfied?	On mobile right now I'll try to be more thorough when I get home, but an important thing to note about the Kurdish people is they have never been a unified people under one state. They've faced oppression by basically every empire that has existed in the area, so they're division today can be seen as a modern continuat...	[ "During the collapse of the Ottoman Empire, Kurds attempted to establish an independent state. On at least one occasion they succeeded and formed the Kingdom of Kurdistan, which lasted from September 1922 until July 1924.\n", "The breakup of the Ottoman Empire after its defeat in the First World War led to its di...
How did the middle class develop? Has there ever been another society with a middle class, either by their own definition or ours?	In European societies, landowners that do not have tenants - ie self-owning farmers have been considered the middle class. These were in ancient times able to afford arms and armour and made up the backbone of the pre-Marian Roman army, of the Greek hoplites and the Swedish medieval peasant militia. Skilled craftsmen w...	[ "The middle class became an important and expanding group in the 19th century. With industrialisation came material gain to the capitalist entrepreneur. New professions came into existence to serve their needs; insurers, engineers, designers. The growth in the population required more architects, lawyers, teachers,...
what would it be like to have no sense of time?	I think you'll wait a long time for a sensible answer to this one. I don't think anyone knows.	[ "The person affected by Alice in Wonderland syndrome may also lose a sense of time, a problem similar to the lack of spatial perspective. Time seems to pass very slowly, akin to an LSD experience. The lack of time and space perspective also leads to a distorted sense of velocity. For example, one could be inching a...
Why can i see more sharply with glasses or contacts after several days of not wearing them?	You can't, you just think you can because you're used to seeing the world blurry.	[ "Many complications arise when contact lenses are worn not as prescribed (improper wear schedule or lens replacement). Sleeping in lenses not designed or approved for extended wear is a common cause of complications. Many people go too long before replacing their contacts, wearing lenses designed for 1, 14, or 30 d...
How do results in the Ancient Greek Olympics compare to today's?	[Slate](_URL_0_) (so consider the source) tried to answer this a couple weeks back > How would the ancient Greeks, who invented the Olympic Games, compete against today’s athletes? > > Probably not well. Ancient athletes could have held their own in the first modern Olympic Games of 1896. Phayllos of Croton, for ex...	[ "As a result of the rise of the Greek cities of the classic period, other great festivals emerged in Asia Minor, Magna Graecia, and the mainland providing the opportunity for athletes to gain fame and riches. Apart from the Olympics, the best respected were the Isthmian Games in Corinth, the Nemean Games, the Pythi...
despite the fact earth consists of 71% water and only 29% land, we still choose to call our planet "earth". why is that?	we live on the ground, not the water. if we were dolphins, then perhaps our planet would be called Oceana.	[ "Earth is the only known planet with seas of liquid water on its surface, although Mars possesses ice caps and similar planets in other solar systems may have oceans. It is still unclear where Earth's water came from, but, seen from space, our planet appears as a \"blue marble\" of its various forms: oceans, ice ca...
How do cell phones work when there are so many people?	Master's level courses on the subject, right here. Alright. So you have this thing called orthogonality, which essentially means that when two signals are multiplied by each other, they equal zero. Cell Towers can only support so many users and over different distances... You know what. Think about it like this. Pre...	[ "Single number means that the mobile phone and the desk phone share an extension number. So only one phone number need be given out to receive calls on either a mobile or desk phone. But the cell phone likely still has its own number, it’s just that one need not give it out to anyone. To make business calls from a ...
what is the true impact/role of the coach on a professional sports team (hockey, soccer, basketball, baseball, football, etc.)?	Coaches that stand out are usually the ones that enable their players to reach their potential. If you look at the role of the coach broadly, you make think a good coach directly affects the game. In some cases, this is true. But what coaches really do is create a situation where the team can function successfully. Tha...	[ "A coach, particularly in a professional league, is usually supported by one or more assistant coaches and specialist support staff. The staff may include coordinators, strength and fitness specialists, and trainers. In elite sport, the role of nutritionists, biomechanists and physiotherapists will all become criti...
Are drops of water consistent in size? How big is that, and why? And what about other substances like oil, or molten metal?	They are not consistent in size. Think about using a micro pipet or any dropper and then think about mist or large droplets of water on a waxed car. Drops of water from the same object are likely to be of similar size due to surface tension (adhesion) and the force on the drop being similar.	[ "The primary factors influencing the initial droplet size produced are frequency of vibration, surface tension, and viscosity of the liquid. Frequencies are commonly in the range of 20–180 kHz, beyond the range of human hearing, where the highest frequencies produce the smallest drop size.\n", "The table below sh...
Did societies in the past understand the problems of hunting animals to extinction?	This answer might be more appropriate to /r/askanthropology, but with North American pre-Columbian timelines the line between history and myth is pretty blurry. One of the only sources of Cherokee oral traditions, Mooney's Myths of the Cherokee (1900), is [available online](_URL_3_). The fourth chapter, "[Origin of D...	[ "Hunters have been driving forces throughout history in the movement to ensure the preservation of wildlife habitats and wildlife for further hunting. However, excessive hunting and poachers have also contributed heavily to the endangerment, extirpation and extinction of many animals, such as the quagga, the great ...
where does the feeling of 'not feeling real' come from?	When I was younger I would also have episodes like this in which I would feel like i was in a dream. I never did get it checked. i did have a few fainting spells (which run in the family). How are your inner ears? do you have vertigo or balance problems? I don't have a fear of heights, but in certain situations/conditi...	[ "Individuals in society want to know every detail about something in hopes to maximize the feeling for that moment, but Wilson found that feeling uncertain can lead to something being more enjoyable because it has a sense of mystery. In fact, the feeling of not knowing can lead them to constantly think and feel abo...
why is it racist to say black people like kfc & watermelon?	It's a generalization based on race. Even if it's not intended to be malicious, it's still racism by definition. Saying Asians are smart is racist. Saying women are good at making sandwiches is sexist. It doesn't have to be an insult.	[ "In 2010, the Australian arm of KFC was accused of racial insensitivity over a television commercial showing an outnumbered white cricket fan handing out pieces of fried chicken to appease a dancing, drumming and singing group of black West Indies supporters. The clip found its way around the world on the internet,...
why are car colors so boring these days?	Manufacturers base the colors of production cars on what customers buy or order.	[ "The most popular car colours today are greyscale colours, with over 70% of cars produced globally being white, black, grey or silver. Red, blue and brown/beige cars range between 6% and 9% each, while all other colours amount to less than 5%.\n", "Fewer paint colours were available and fewer models. Many of the ...
how does the ability of a spider to make a web get passed from one generation to the next?	It is not taught/learned. Though complex, it is a fully instinctive behavior, which means the ability to do it is built into their DNA, just as humans have for breathing or crying or sex.	[ "This spider builds a funnel-shaped web to catch its prey. It usually consists of a multitude of stressed silk threads spun over a flat surface (such as a window sill) near any corner, with a funnel-like structure reaching for the corner, in which the spider would typically reside (hence the name). These webs can b...
why can there be such a delay between a music album release and radio play?	It's all about the major labels paying oceans of money to make certain songs 'popular' or get Airplay	[ "For the first time since Excited in October 1992, some six years prior, and some twelve consecutive singles later, radio seemed quite reluctant to play the single and rotate it. Even lesser charting sales singles, like Fantasy Island received more immediate airplay. Generally, radio support for the single grew slo...
why is reality television so appealing to many?	Regarding trashy TV, people like to feel superior to others. Watching people be portrayed as vapid imbeciles increases their relative self worth. This is more true for stuff like Maury than most reality TV but it's the stereotype.	[ "Reality television has long existed in the United States, both played for laughs (such as \"Candid Camera\" and \"Real People\") and as drama (such as \"COPS\" and \"The Real World\"). A new variant – competition series placing ordinary people in unusual circumstances or in talent contests, generally eliminating a...
If I opened a bag of flour in zero gravity what would happen?	If you open a bag of flour and shake it, it will go everywhere. The only force that acts on it is the force that you shook it with. Any clumps of flour already in the bag might stay together depending on how hard you shook it and new clumps might form form a collision. If you add water by filling a bag and shaking i...	[ "Wheat flour tortillas have been used on many American spaceflights since 1985 as an easy solution to the problems of handling food in microgravity and preventing bread crumbs from escaping into delicate instruments.\n", "Flour dust suspended in air is explosive—as is any mixture of a finely powdered flammable su...
why do jehovahs witnesses keep coming to my door?	Because they want you to convert to their religion. Can you be more specific about your question. It seems pretty straightforward. Edit: If you want them to go away tell them that you're a ex-jehovah's witness who has been disfellowshipped (excommunicated).	[ "Jehovah's Witnesses believe that the kingdom of God is the central theme of the Bible, of Jesus' message while on earth, and of their own door-to-door preaching. They believe their door-to-door preaching is part of a \"sign\" before God's kingdom destroys the world's governments, in order to have God's will done o...
In the novel "Go Set a Watchman," Jean-Louise and her uncle are having a conversation about the causes of the Civil War and her uncle says, "not much more than five per cent of the South's population ever saw a slave, much less owned one." Is there any truth to that?	No. It's absolute baloney and incredibly racist. The 1860 U.S. Census found that 40 percent of the population of the South was enslaved. I'm quite sure that they were aware, every single day of their lives, of their status as a slave. But let's take the racist's point of view. Let's say a slave isn't a person a...	[ "Despite these criticisms, the novel still captured the imagination of many Americans. According to Stowe's son, when Abraham Lincoln met her in 1862 Lincoln commented, \"So this is the little lady who started this great war.\" Historians are undecided if Lincoln actually said this line, and in a letter that Stowe ...
if we could travel at the speed of light or use warp speed how would you avoid hitting any space debris or planets?	Space is vastly empty. The chances of you colliding with anything at all is very very slim. You usually only collide with things that you're trying to collide with. Even the asteroid field is very empty. Every asteroid is small and hundreds of thousands of miles apart. Before going into warp speed presumably...	[ "Rather than exceeding the speed of light within a local reference frame, a spacecraft would traverse distances by contracting space in front of it and expanding space behind it, resulting in effective faster-than-light travel. Objects cannot accelerate to the speed of light within normal spacetime; instead, the Al...
"alternative facts"	Kellyanne Conway, advisor to and spokesperson for Donald Trump, came up the with the term "alternative facts" as a way of brushing off press accusations that Trump's press secretary was caught in a lie over the size of the inauguration crowd. Specifically, the administration claimed (through the Press Secretary) that i...	[ "In a Breitbart News article dated January 23, 2017, editor Joel Pollak defended Conway's use of \"alternative facts\" by arguing that it was a harmless and accurate term in a legal setting, \"where each side of a dispute will lay out its own version of the facts for the court to decide.\" \"The Guardian\" noted th...
at what point is a virally infected person no longer considered a "carrier"? how can we become immune to certain things without carrying/spreading the sickness ?	I'm interested in this answer also. Some viruses we keep for an awfully long time - how do we know Ebola isn't going to be like HIV or herpes?	[ "Asymptomatic carriers can be categorized by their current disease state. When an individual transmits pathogens immediately following infection but prior to developing symptoms, they are known as an incubatory carrier. Humans are also capable of spreading disease following a period of illness. Typically thinking t...
where do funds come from for fireworks in sydney or elsewhere?	City budget. Which come from taxes	[ "In 1981, officials of the fire department set up a nonprofit organization called Olde 23 to raise funds to build the museum, but sufficient funds were never raised. The projected cost of the museum, even in 1982, was $1 million, and critics questioned the wisdom of building a museum in Skid Row. In 1988, the city ...
why do livestreams consume more bandwidth than vods?	Compression is slow, the more you compress the slower it gets. Video on demand has days to compress the video into the smallest size for each quality level so they can make it much smaller Livestreaming at 24 fps gives the computer 1/24 of a second to compress the current frame before it needs to send it out and move...	[ "Compared to server-based streaming, p2p-based streaming saves on data costs for the service provider, at the same time as the distribution becomes more robust, since it only grows stronger with every additional user. What distinguishes Vnet from traditional p2p is that Vnet allows an administrator to have central ...
how can the brain accurately pick up song lyrics from a song you last heard 10 years ago?	This is called long-term memory. You perceive something, let's say, you listen to a song. This information enters your brain as information in the so-called working memory. Stimuli that are not processed (because they are irrelevant to us) are lost after a couple of seconds. But, stimuli like that one song you find rea...	[ "The song system has emerged as leading model of adult neural plasticity. The song system is the first neural circuit in which it was conclusively demonstrated that newly generated neurons are incorporated into the brains of adults vertebrates. Some seasonally-breeding songbird brains vary in volume, neuron number,...
in world cup games, what language does the referee speak to the players in?	Asked and answered 10 times already. English	[ "He speaks Russian and English and has been an international referee since 1 January 1997. The first international game he refereed was Luxembourg–Poland in 1999. Before his qualification he served as an assistant referee and officiated 3 games in the 1994 World Cup.\n", "For the first time at a World Cup, match ...
How does this "real" invisibility cloak work?	Roughly speaking, you can make light "stick" to tiny periodic conducting structures and bend this sticky light around a surface and release it behind it in a way that removes all information of the surface as the light travels past the surface. I think such a device could actually be constructed for selected wavelength...	[ "The invisibility cloak is basically the medium on which light waves refract. Invisibility cloaks allow for an object to be undetected while confined in the area of the cloak. In other words, the viewer does not see the real object. In illusion optics, devices are not limited to only invisibility cloaks. For exampl...
Did everyone get mummified in Ancient Egypt?	No, not everyone was mummified. Simple reason being, mummification was a long and ultimately costly process. Therefore, it's not surprising that most of the mummified remains we've ever found are either royal or of some high political, military or religious official. Those who weren't mummified were usually buried in...	[ "Mummification was a practice that the ancient Egyptians adopted because they believed that the body needed to be preserved in order for the dead to be reborn in the afterlife. Initially, Egyptians thought that like Ra, their physical bodies or Khat, would reawaken after they completed their journey through the und...
What was the most powerful military organisation in history?	I think you need to perhaps clarify your question. Do you mean relative to their contemporaries? Absolute destructive potential? If it is the latter the answer is either the Soviet Union or USA thanks in no small part to the stockpiling of nuclear weapons. I can't say specifically when or which without looking up t...	[ "The United States Army, with 39,000 men in 1890 was the smallest and least powerful army of any major power in the late 19th century. By contrast, France had an army of 542,000. Temporary volunteers and state militia units mostly fought the Spanish–American War of 1898. This conflict demonstrated the need for more...
how do tree farmers keep up with the global demand for paper?	Ooo! I can answer this! I studied forestry back in North Carolina, with a focus on sustainable paper milling! 1st: Manufacturing paper is fairly efficient, especially compared to other uses of wood. The wood is pulped and pressed into paper of various uses, which mean a lot of the material doesn’t get wasted (glancing...	[ "Worldwide consumption of paper has risen by 400% in the past 40 years leading to increase in deforestation, with 35% of harvested trees being used for paper manufacture. Most paper companies also plant trees to help regrow forests. Logging of old growth forests accounts for less than 10% of wood pulp, but is one o...
if kinetic energy is proportional to velocity squared...	This is an EXTREMELY good question. I've looked into this many times myself, mainly due to my involvement in /r/emdrive. Stay away from that sub, they literally think the Illuminati is preventing scientific progress. So, in your closed system, there are two components. The train car, and the rocket fuel. At then end o...	[ "Kinetic energy is the energy of motion. The amount of translational kinetic energy found in two variables: the mass of the object (m) and the speed of the object (v) as shown in the equation above. Kinetic energy must always be either zero or a positive value. While velocity can have either a positive or negative ...

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