Split (2)

train · 226k rows

question stringlengths 3 301	answer stringlengths 9 26.1k	context list
why do women enjoy sex even if they don't climax yet men are left relatively unsatisfied when they don't "finish the job"?	She is just being nice	[ "This chapter declares that many wives are not as satisfied by sexual encounters as they could be because they fail to achieve orgasm. Eleven reasons are given why women might experience dissatisfaction with sex and suggestions are given on how to overcome those problems.\n", "Orgasm is not always achieved easily...
Why did America abandon Czechoslovakia and let it fall behind the Iron Curtain?	Are you referring to 1948 or 1968?	[ "The nations behind the Iron Curtain were Poland, East Germany, Czechoslovakia, Hungary, Romania, Bulgaria, Albania and the USSR; however, East Germany, Czechoslovakia and the USSR have since ceased to exist.\n", "After World War II, the Czechoslovak government-in-exile returned. Normal relations continued until ...
People often say that the 1950s were a "simpler time" compared to now. What negative aspects of the 1950s are they overlooking?	There are a number of ways to compare and contrast a previous era in America with today. One I find particularly compelling is to consider the lived experiences of children with physical or cognitive disabilities - especially those born into families who had been historically marginalized by laws, policies, and cultura...	[ "The Great Depression at the end of the '20s and during the '30s disillusioned people about the economic stability of the country and eroded utopianist thinking. The outbreak and the terrors of World War II caused further changes in mentality. The Post-war period that followed was termed Late Modernism. The \"Postm...
there are different types of galaxies, but..how?	The formation of galaxies is still a very open question and scientific understanding continues to evolve rather quickly as scientific theories go. One big way that we suspect that we get different 'types' of galaxies is through collusions. When two galaxies get close enough to each other, structures like spiral arms c...	[ "A galaxy is a large gravitational aggregation of stars, dust, gas, and an unknown component termed dark matter. The Milky Way Galaxy is only one of billions of galaxies in the known universe. Galaxies are classified into spirals, ellipticals, irregular, and peculiar. Sizes can range from only a few thousand stars ...
the physics behind curling	I don't think it can be explained any better than this: _URL_0_	[ "Curling is a sheet metal forming process used to form the edges into a hollow ring. Curling can be performed to eliminate sharp edges and increase the moment of inertia near the curled end. Other parts are curled to perform their primary function, such as door hinges.\n", "Curling can be an effective technique w...
Why does the 4s orbital fill before the 3d orbital, even though it's physically further out from the nucleus?	Check out the [radial probability distribution of the two orbitals](_URL_3_) - while you're correct in that the maximum for 4s is further out than the 3d, they're very close, and 4s orbital has further penetration near the nucleus, thus is less shielded than the 3d orbital. This is reflected in that the orbital energie...	[ "Orbital decay can occur due to tidal forces for objects below the synchronous orbit for the body they're orbiting. The gravity of the orbiting object raises tidal bulges in the primary, and since below the synchronous orbit the orbiting object is moving faster than the body's surface the bulges lag a short angle b...
Can someone explain me the second law of thermodynamics and concept of entropy?	The second law is statistical. A law of averages, if you will. For example: > Heat can never flow from a cold body to a hot body Not so! It actually does go from cold to hot. However, more heat flows from the hot body to the cold body. It is statistical. This happens until the rates both ways are equal. Fo...	[ "The idea that the second law of thermodynamics or \"entropy law\" is a law of disorder (or that dynamically ordered states are \"infinitely improbable\") is due to Boltzmann's view of the second law of thermodynamics.\n", "The first law of thermodynamics provides the basic definition of internal energy, associat...
Why do dogs howl at seemingly random hours of the night?	Dogs have incredibly keen hearing. They tend to howl when they hear another dog howl. It's plausible that they hear another dog howling off in the distance and join in the chorus because it's entirely socially acceptable for them. It could also be because they are hearing some random sound, such as a siren, in the dist...	[ "Twilight Bark (sometimes, \"Twilight Barking\" and \"Barking Chain\") refers to the often-noted behavior in domestic dogs (\"Canis lupus familiaris\") of exchanging barks or howls across long distances, typically in the quiet hours of early evening.\n", "The \"curious incident of the dog in the night-time\" is e...
what don't cotton, wool, and leather clothes decay if they are made from organic sources?	Ultimately they're preserved in some way and dried. Cotton wool and leather do decay if left to the elements	[ "Now that there is continuous increase in the amount of clothing that is consumed, another issue that arises is that the clothing is no longer made from natural materials/crops. Clothing used to be produced by mainly \"natural fibers\" such as wool, cotton or silk. Now there is a switch from natural fibers to inexp...
Could Pi have another value in another universe?	Pi itself is defined in abstract terms, so unless the laws of logic changed the value would be the same. HOWEVER, the ratio of a circle's circumference to its diameter isn't always equal to pi. Einstein's theory of general relativity predicts that gravitational fields cause a curvature of space and time, and thus the...	[ "Pi certainly seems to behave this way. In the first six billion decimal places of pi, each of the digits from 0 through 9 shows up about six hundred million times. Yet such results, conceivably accidental, do not prove normality even in base 10, much less normality in other number bases.\n", "It has also been ex...
what made windows vista so bad in comparison to windows xp and 7?	I don't think it's fair to say vista was bad, it was just not as accepted as xp / 7 Although when it was released vista didn't have a lot of driver compatibility or software compatibility, it had more security prompts which essentially made things more difficult to do than you could do with xp and because windows 7 wa...	[ "When released, Windows Vista was criticized for its long development time, performance issues, spotty compatibility with existing hardware and software on launch, changes affecting the compatibility of certain PC games, and unclear assurances by Microsoft that certain computers shipping with XP prior to launch wou...
In what era was humanity most susceptible to a mass extinction?	The Mt Toba eruption around 76,000 years ago supposedly reduced the human population to less than 10,000.	[ "Continuing human hunting and environmental disturbance has led to additional megafaunal extinctions in the recent past, and has created a serious danger of further extinctions in the near future (see examples below). Direct killing by humans, primarily for meat, is the most significant factor in contemporary megaf...
why are cantonese and mandarin the main languages in china?	First off, you need to understand that Cantonese and Mandarin are only 2 of the hundreds of regional dialects spoken in China. It's just that those two are the most widely spoken outside of China (others include Toisanese, Hakka, Shanghainese, Fukinese, etc...). The reason that there are so many dialects in China i...	[ "Due to the linguistic history of Hong Kong and Macau, and the use of Cantonese in many established overseas Chinese communities, the use of Cantonese is quite widespread compared to the presence of its speakers residing in China. Cantonese is the predominant Chinese variety spoken in Hong Kong and Macau. In these ...
Is a single Elephant's skin cell bigger than a human's skin cell?	No, while cells can come in various sizes there's something called the [Square-Cube law](_URL_0_) that basically means that the larger an object becomes, its volume grows faster than its surface area. This might sound obvious but because cells have to traffic things into and out of their surfaces in order to process nu...	[ "In contrast to chimpanzees, a common morphological variant found in humans called Hirsuties coronae glandis, or pearly penile papules, are substantially larger, appear to be an outpocketing of both surface and underlying connective tissue layers, and lack the rich innervation seen in other animals. These are somet...
how does the brain repress memories and not let people remember entire parts of their lives?	Just to make clear "repressed memories" isn't a medically sound diagnosis. There are known issues related to people struggling with memories around a traumatic event or time. The two more common issues are: Denial- Something really traumatic happens and as a protective measure, your brain won't allow a solid memor...	[ "Human beings are blessed with having an intelligent and complex mind, which allows us to remember our past, be able to optimize the present, and plan for the future. Remembering involves a complex interaction between the current environment, what one expects to remember, and what is retained from the past. The mec...
how are there so many different "world champions" for the same weight class in boxing? how does it work?	WBA, IBF, BO and IBO are all different boxing organizations. Imagine it more like there was an NBA, and a Southern Basketball League and a Northern Basketball League and a World Basketball League and a International Basketball League and all of the same teams played. You could have one team hold the titles for all of...	[ "In boxing, the individual organizations such as the World Boxing Council, the World Boxing Association, the International Boxing Federation, and the World Boxing Organization each have their own unique championship belt that are awarded to the champions of each weight class. Boxers strive to win the belt of all fo...
why is today's announcement of the discovery of gravitational waves important, and what are the ramifications?	Edit: I wrote my original answer in response to OP's question, but there still seems to be a lot of confusion. It might help if I write a bit of a summary about what gravitational waves actually are, and I'm adding that to the top here: What are gravitational waves? What is LIGO? - In Einstein's Theory of G...	[ "The first, indirect, detection of gravitational waves came in the 1970s through observation of a pair of closely orbiting neutron stars, PSR B1913+16. The explanation of the decay in their orbital period was that they were emitting gravitational waves. Einstein's prediction was confirmed on 11 February 2016, when ...
Why did early America decide upon creating an entire new city (Washington, D.C.) to be the capital of the new United States, as opposed to deciding upon an existing major city?	As with most things involving Washington D.C., the decision of where to found the Federal city was rife with politics. The downvoted points below do have some truth to them, but it's not the entire story. The idea of a designated district for Congress had existed for years. Benjamin Rush wrote to Colonel Morgan in Nov...	[ "In 1785, the assembly of the Congress of the Confederation made New York City the national capital shortly after the war. New York was the last capital of the U.S. under the Articles of Confederation and the first capital under the Constitution of the United States. In 1789, the first President of the United State...
if cigarettes contain things like arsenic, butane, cadmium, ammonia, and formaldehyde, how can people smoke then everyday for years without dying within the first few weeks?	There is no such thing as lethal or safe substances. There are only lethal and safe doses. Water can be toxic if you drink enough of it.	[ "Cigarettes are the major form of smoked tobacco. Risks to health from tobacco use result not only from direct consumption of tobacco, but also from exposure to second-hand smoke. Approximately 10% of cardiovascular disease is attributed to smoking; however, people who quit smoking by age 30 have almost as low a ri...
Variable S in Laplace Transforms?	Laplace transforms are like continuous power series (which are, essentially, Taylor series without the n! in there). If I have a list of numbers a_0_, a_1_, a_2_,..., then, assuming convergence, I can create the function * g(x) = a_0_ + a_1_ x + a_2_x^(2) + ... I can even consider the function F(s) = f(e...	[ "The following is a list of Laplace transforms for many common functions of a single variable. The Laplace transform is an integral transform that takes a function of a positive real variable (often time) to a function of a complex variable (frequency).\n", "which has the advantage that is zero when is constant a...
Is entropy lowered when an egg or ice is formed?	2nd Law doesn't say entropy can't decrease anywhere, just that the total entropy of the universe will not decrease. When water freezes, the entropy of the system (the water) decreases. The entropy of the surroundings increases.	[ "The current consensus hinges upon the Boltzmann-Shannon identification of the logarithm of phase space volume with the negative of Shannon information, and hence to entropy. In this notion, a fixed initial state of a macroscopic system corresponds to relatively low entropy because the coordinates of the molecules ...
how do linesmen detect where the breaks in wires are to repair them?	I do telephone and we use a TDR (time domain reflectometer) that sends a pulse out and times how long it takes an echo to return the unit (based on a given gauge of wire) and it shows the length on the wire. We have records that indicate what the distance should be and compare that to the result.	[ "A break in the wire is repaired by tying the ends together and trimming. When such a repair is made to an existing recording, a jump in the sound results during playback, but because of the high speed of the wire the loss of an inch due to tying and trimming is trivial and might pass unnoticed. Unfortunately, if t...
why did luminescence evolve in deep sea organisms	In the absence of light from the sun, using bioluminescence gives deep sea organisms access to many sight-based behaviors. The light can be used as everything from a mating display to a defensive response. Visual signals are very strong and useful, and since there is no ambient light, they evolved to create their own.	[ "Due to the total darkness in the zones past the epipelagic zone, many organisms that survive in the deep oceans do not have eyes, and other organisms make their own light with bioluminescence. Often the light is blue-green in color, because many marine organisms are sensitive to blue light. Two chemicals, luciferi...
what's the biological impact of removing wolves from an area, and what is the biological impact of reintroducing a new population?	Removing predators like wolves can lead to overpopulation. There are more deer in North America today than when the pilgrims arrived. This can lead to starvation, disease, crop damage, and traffic accidents. Reintroducing predators, if done correctly, can control those populations. It can also, in theory, lead to r...	[ "Wolf population declines, when they occur, result from \"intraspecific strife,\" food stress, mange, canine distemper, legal hunting of wolves in areas outside the park (for sport or for livestock protection) and in one case in 2009, lethal removal by park officials of a human-habituated wolf.\n", "Apart from do...
china, "the chinese sea", international waters.	A country's sea borders extend 10 miles from their land borders...basically they have the right to police and prosecute actions that take place within 10 miles of their borders. China has been effectively building man made islands that they are using to extend these borders further into international waters. The crux o...	[ "\"South China Sea\" is the dominant term used in English for the sea, and the name in most European languages is equivalent. This name is a result of early European interest in the sea as a route from Europe and South Asia to the trading opportunities of China. In the sixteenth century Portuguese sailors called it...
why do grey shirts almost always have that weird pattern on them?	The color of the shirt you are referring to is heather grey. Heather refers to interwoven yarns of mixed colors producing flecks of an alternate color. It is typically used to mix multiple shades of grey or grey with another color to produce a muted shade (e.g., [heather green](_URL_0_)), but any two colors can be mi...	[ "The intended use of shirts dictates different choices of pattern. For example, country shirts are usually checked, with checks of different size to co-ordinate with tweeds of different pattern, and featuring one, two, or sometimes more colours of check over a light cream or white background. For city shirts, plain...
why is samsung still making processors for apple phones despite being their competitor?	If Samsung doesn't make the processor then TSMC or Global Foundries will. Right now Samsung has a more advanced processor making technology than those other do, but if Samsung refuses Apple can certainly work something out. Samsung can't just make Apple give up by not making the A9. Samsung might as well make some ...	[ "On June 6, 2005, Steve Jobs, then CEO of Apple, announced that Apple would be transitioning from its long favored PowerPC architecture to the Intel x86 architecture because the future PowerPC road map was unable to satisfy Apple's needs. The first Macintosh computers containing Intel CPUs were announced on January...
how does smoking cause asthma?	Smoking is combustion. Combustion causes a byproduct: the smoke. Smoke is a bunch of small particles. Particles that don't belong in your lungs cause it to react. That reaction can be in the form of an asthma attack.	[ "Asthma, COPD, and smokers have reduced airflow ability. People who suffer from asthma and COPD show decreases in exhaled air due to inflammation of the airways. This inflammation causes narrowing of the airways which allows less air to be exhaled. Numerous things cause inflammation some examples are cigarette smok...
Did the romans use advertisements?	Yes! We have found several murals and inscriptions that can be classified as advertisements. For instance, in Pompeii we have found the following mural: \|Cn\[aeum\] Helvium\|We pray that you will make Gnaeus Helvius\| \|:-\|:-\| \|Sabinum aed\[ilem\]\|Sabinus, worthy of the Republic, an aedile.\| \|d\[ignum\] r\[ei\] p\[ublica...	[ "The history of advertising can be traced to ancient civilizations. It became a major force in capitalist economies in the mid-19th century, based primarily on newspapers and magazines. In the 20th century, advertising grew rapidly with new technologies such as direct mail, radio, television, the internet and mobil...
How do we know how many isotopes exist in the universe for an element, and their percentages, to determine the atomic mass? As we discover new isotopes, does a printed periodic table become obsolete because that element will have a new atomic mass?	There are 22 mononuclidic elements. The abundances of those don't change. Those are important for calibrating detectors and such. For the rest, standard atomic weights are revised biennially by the IUPAC's [Commission on Isotopic Abundances and Atomic Weights](_URL_1_) (CIAAW). Should you ever have trouble sleeping...	[ "The tabulated atomic masses of elements are averages that account for the presence of multiple isotopes with different masses. Before the discovery of isotopes, empirically determined noninteger values of atomic mass confounded scientists. For example, a sample of chlorine contains 75.8% chlorine-35 and 24.2% chlo...
what is a hydraulic press actually used for? other than clickbait videos	Kitchen sinks. The metal ones, that seem to be made out of a single piece of metal that just happens to be the shape of a sink? That is most likely a single piece of metal which was squeezed into shape by a hydraulic press. The drain gets cut out at the same time. The drain cover can even be cut at the same time. O...	[ "A hydraulic press is a machine (see machine press) using a hydraulic cylinder to generate a compressive force. It uses the hydraulic equivalent of a mechanical lever, and was also known as a Bramah press after the inventor, Joseph Bramah, of England. He invented and was issued a patent on this press in 1795. As Br...
how come the sun is able to light up the earth with out problem, but when ever we see videos of space, the sun doesn’t apear to be bright at all, even though there’s no atmosphere to block out its light waves, why is this?	You answered the question, just with the wrong logic. If you imagine the sun as a point of light, and your eyes the receiver of the photons. You will only receive a small amount of those photons, so while the light will be bright if you look at it directly, if you look away from it, you won't be seeing any of the photo...	[ "With such a large visual angle, it can be very difficult at times to keep undesired objects such as light sources out of the image. However this does not always pose a problem, as even the sun in a photograph takes up such a small amount of space that its presence can often have little negative impact on the overa...
why is it so hard to study 1 hour straight, but you can spend 8 hours gaming or doing sth else with no problem?	For the same reason that it's easy to lay down rather than jog; one is a relatively passive, low-effort activity, and the other is learning something new.	[ "Consistently long sessions of video game play also leads to an increased likelihood of lower back pain, according to a study conducted in a population of school children. Children who played video games for more than 2 hours a day were more inclined to have lower back pain, however the same could not be said for t...
why do some countries teach multiplication tables to x12, and others teach to x10?	12 is an important number historically for various systems of measurement. 12 hours in a day. 12 inches in a foot. 12 eggs in a dozen. 12 is handy because it can be divided by 2, 3, 4, 6 evenly. So many things were done in lots of up to 12. So if you wanted to multiply lengths, you're going to be doing something ...	[ "The Chinese multiplication table consists of eighty-one sentences with four or five Chinese characters per sentence, making it easy for children to learn by heart. A shorter version of the table consists of only forty-five sentences, as terms such as \"nine eights beget seventy-two\" are identical to \"eight nines...
When were classical music, opera and jazz at their peak in terms of popularity? To what do you attribute their subsequent decline?	/u/caffarelli already answered, but I guess I can add a couple things (focusing the instrumental side of "classical music"). This is a musical tradition. The term covers a hell of a lot of things. As caffarelli mentioned, art music is commonly used. Art music doesn't work for some of the things "classical music" cover...	[ "According to cultural historian Hannu Salmi, classical music began to gain public prominence in Western Europe in the latter 18th century through the establishment of concerts by musical societies in cities such as Leipzig and the subsequent press coverage of these events. This was a consequence of the Industrial ...
Could our gas giants slowly be turning into stars?	No, they could not be. They are far too small to be stars. You would need at least 80 times the mass of Jupiter to get an actual star with hydrogen fusing into helium, and Saturn is not even 1/3 the mass of Jupiter, while Uranus and Neptune each are at about 5% the mass of Jupiter.	[ "A gas giant however would not be massive enough to do this, leaving the various measurable properties of the star (rotation speed, chromospheric activity) unchanged. If the giant and the primary were close enough for the magnetic fields to be linked, the orbit of the planet would wrap the field lines until the con...
How deep does dirt go?	You'll have to find some sort of geographical map or ask a local geography teacher to know more about your area. I went to a Bellevue, WA College (BC) where our class talked about how Bellevue is a mess from tectonic activity, got to see a couple local caves and then found out dirt can go down 5-30' in some places be...	[ "Soil excavated from the hole, usually sitting in a pile next to the hole ready for backfilling. Ideal sequence will be that the dug up soil will have material dug through first at the bottom of the pile, with material from deeper down on top of the pile. In optimal situations, the location of dug up soil can be de...
why do humans have to train hard to reach peak physical performance, but animals just go about their lives and are naturally at their peak so long as there's no birth defect or disease?	Who's to say that are at their peak though? Surely, if we could train an animal like we do a professional athlete, they would get even stronger and faster.	[ "Humans are specifically adapted to engage in prolonged strenuous muscular activity (such as efficient long distance bipedal running). This capacity for endurance running may have evolved to allow the running down of game animals by persistent slow but constant chase over many hours.\n", "A study in 2003, by the ...
How supportive was Socrates of the Thirty Tyrants?	First of all, it is extremely difficult to know anything about the historical Socrates. So, I will just be referring to Socrates as he appears in Xenophon. > Was there any overlap in philosophy/ideals? Yes. All of them were elitist, anti-democratic admirers of Sparta. In fact, Sparta installed the Thirty as a satel...	[ "As with many of the issues surrounding Socrates' conviction, the nature of his affiliation with the Thirty Tyrants is far from straightforward. During the reign of the Thirty, many prominent Athenians who were opposed to the new government left Athens. Robin Waterfield asserts that \"Socrates would have been welco...
why do people get angry when you tell them to calm down?	If they're already angry, telling them to calm down is essentially telling them that their anger is invalid. It's saying, "You shouldn't be feeling the emotions you're feeling right now, so just stop it." If they're not already angry, they're likely to get angry (or at least frustrated) because you're making unfo...	[ "It is generally difficult for most people to remain calm and collected in a conflict situation. However, an increase in negative emotions (i.e. anger) only exacerbates the initial conflict. Even when group members to discuss their positions calmly and dispassionately, once they become committed to their positions,...
Did US forces commonly kill (intentionally) Vietnamese civilians during the war?	You're asking a very good question and to answer it, we have to start with the cause rather than the act itself. The Vietnam War was a counterinsurgency war. Now, counterinsurgency wars have an absolutely devastating effect on the human mind for the men who carry it out due to the fact that you are not fighting again...	[ "According to the Information Bureau of the Provisional Revolutionary Government of South Vietnam (PRG), between April 1968 and the end of 1970 American ground troops killed about 6,500 civilians in the course of twenty-one operations either on their own or alongside their allies. Three of the massacres reported on...
why do most animals, especially sea life, generally ignore / not attack humans?	Animals don't have hospitals nor healthcare. A major disability will be the end of you and even the smallest wound can become infected and lead to death. Humans are pretty big animals, even predators are not too eager to take chances.	[ "All sea creatures have developed their own ways to kill and to avoid being killed. Beside visual, hearing and smelling sense there are also specific ways for species such as dolphins' sonar to find hidden fish, or angel shark's cunning disguise.\n", "Aquatic animals (especially freshwater animals) are often of s...
Is it possible to pull an asteroid into our own orbit?	[Chinese Scientists Plan to Pull an Asteroid into Orbit Around Earth](_URL_0_)	[ "Considering possible hovering positions or orbits of the tractor around the asteroid, note that if two objects are gravitationally bound in a mutual orbit, then if one receives an arbitrary impulse which is less than that needed to free it from orbit around the other, because of the gravitational forces between th...
Why is hydrofluoric acid (HF) so corrosive if it is only a weak acid?	The "weak" and "strong" acid designation can be confusing - here, these words mean how much it dissociates (breaks apart into H^+ and the counterion) in solution. A "weak" acid such as HF remains more in the molecular form. This means that a certain concentration of a weak acid will not have as low a pH as a strong aci...	[ "Hydrofluoric acid is the weakest of the hydrohalic acid, having a pKa of 3.2 at 25 °C. It is a volatile liquid due to the presence of hydrogen bonding (while the other hydrohalic acids are gases). It is able to attack glass, concrete, metals, organic matter.\n", "HF-SbF is extremely corrosive, toxic, and moistur...
how to police pinpoint a phone call?	Police officer here. Though, I'm not completely qualified to answer this, as I don't deal with that sort of thing. However; the "keep them on the line" thing they do in movies is complete fiction. Landlines can be traced instantly. For cell phones, they either triangulate using cell phone towers, or use the location ...	[ "The people of the communications centre have to judge the calls in such a way that something is done, fast and properly. If a call is serious, an employee in the communications centre will have to directly choose which police officers are to be dispatched to the address. The communications centre employees know ex...
why do natural gas water heaters need venting but a gas stove does not.	A gas hot water system uses anywhere from three times to eight times the gas of a gas stove or range. Combustion generates a certain amount of carbon monoxide. The less oxygen you have, the more CO you generate. A water heater will generate a fair amount of CO even with adequate oxygen. A stove or gas range will genera...	[ "Because kerosene heaters are usually unvented, all combustion products are released into the indoor air. Among these are low levels of nitrogen dioxide and carbon monoxide. An improperly adjusted, fueled, or poorly maintained kerosene heater will release more pollutants, particularly through incomplete combustion....
does density have any direct relation to hardness/toughness?	Density is a factor, but more important is the molecular structure. A diamond is one of the hardest things around because the molecules are arranged in a lattuce structure. As far as iron and steel, same idea. The steel has added metals that fit in nicely with the iron giving it added strength.	[ "The density is about 3.31 to 3.33 g/cm. This might be the case due to some impurities in the structure of the mineral. It has a hardness of 6 on the Mohs scale, this hardness is due to the short length of the bond in the structure, since is relative short tends to be harder.\n", "Hardness is difficult to quantif...
why you need to be grounded to get an electric shock?	Electric currents aren't like Austin from middle school, they don't come out, wander around, bug people, and then go back home. Electricity flows from negatively charged objects, to positively charged objects, until the system is neutral. That's all there is to it. If electricity flows from one location, that means t...	[ "In power transmission systems, one side of the circuit, known as the neutral, is grounded to dissipate static electricity and to reduce hazardous voltages caused by insulation failure and other electrical faults. It is possible to get a shock by only touching the \"hot\" wire, due to the person's body being capaci...
When/how did militaries go from being led by knights and/or nobles to "officers"?	Even in the middle ages, many officers were non-nobles, at least in English armies. When Edward I (also known as Edward Longshanks) called for war, the common men were mobilized by shires. They were sorted into groups of twenty, with an officer called a ventenarius, then into larger groups of one hundred men, command...	[ "Secondly, from the 9th century on, military ability was increasingly seen as conferring special status, and professional soldiers or \"milites\", generally in the entourage of sworn lords, began to establish themselves in the ranks of the aristocracy (acquiring local lands, building private castles, seizing elemen...
What were the main influences of music in communist east germany?	I don't know if that's what you're implying, but Kraftwerk was founded in 1970 in Düsseldorf - West Germany. And Rammstein was founded in 1994, but granted, by musicians who grew up in the GDR. Unfortunately I'm not knowledgeable enough to give an academical answer on the question as a whole, but I wanted to at lea...	[ "The culture of East Germany varied throughout the years due to the political and historical events that took place in the 20th century, especially as a result of Nazism and Communism. A reflection on the history of arts and culture in East Germany reveals complex relationships between artists and the state, betwee...
why do catholics practice "lent"?	In Christian traditions, taking penance usually in the form of fasting or giving up certain luxuries is a method of prayer to bring one closer to God. The idea is that worldly luxuries like video games, ice cream, etc may make people value Earth rather than look forward to heaven.	[ "Lent (Latin: \"Quadragesima\", 'Fortieth') is a solemn religious observance in the Christian liturgical calendar that begins on Ash Wednesday and ends approximately six weeks later on Holy Saturday, the day before Easter Sunday. The purpose of Lent is the preparation of the believer for Easter through prayer, doin...
Has Rosetta significantly changed our understanding of what comets are?	Doesn't look like anyone has chimed in yet, and this is getting a lot of votes. So let me just say this for now: Rosetta got there 3 months ago and Philae landed last week. Scientists have had the data from the lander in their hands for less than a week, and whatever science Rosetta is doing from orbit is just gett...	[ "Comet is a 1985 popular-science book by Carl Sagan and Ann Druyan. The authors describe the scientific nature of comets, as well as their varying roles and perceptions throughout history. The evolution of human understanding of comets is also detailed, and thinkers and astronomers such as Edmond Halley, Immanuel K...
How vulnerable were the British naval ships at Dunkirk to aerial attacks?	The most prevalent type of Royal Navy ship present at Dunkirk was the destroyer, with a total of 40 ships of the type. Of these, six were sunk: one by submarine, one by torpedo boat and four by aircraft. Another 23 were damaged, almost entirely by aircraft. Most of the destroyers taking part in the evacuation were olde...	[ "During the Battle of Dunkirk, many Allied ships were lost to Ju 87 attacks while evacuating British and French troops. The French destroyer was sunk on 21 May 1940, followed by the paddle steamer \"Crested Eagle\" on 28 May. The French Channel-steamer \"Côte d'Arzur\" (3,047) followed. The Ju 87s operated to maxim...
Is global warming a natural process?	Climate change is a result of natural processes. Anthropogenic climate change is artificial.	[ "Global warming refers to the warming caused by human technology since the 19th century or earlier. Projections of future climate change suggest further global warming, sea level rise, and an increase in the frequency and severity of some extreme weather events and weather-related disasters. Effects of global warmi...
if the sun has half of its energy left, it has 5 billion more years. will the energy slowly wane over that time, or do stars go out with a poof?	some do some dont, our sun is too small to go super nova, it will turn into red giant after 5.4 billion years sun will become duoble in size in half a billion years, and then in next half billion it will expand rapidly becoming 200 times larger and becoming red giant for about 1 billion years, after that sun will have...	[ "In theory, the loss of energy through gravitational radiation could eventually drop the Earth into the Sun. However, the total energy of the Earth orbiting the Sun (kinetic energy + gravitational potential energy) is about 1.14 joules of which only 200 watts (joules per second) is lost through gravitational radiat...
how do tapedeck audio cables work?	The signal on the wire isn't digital. It's an ordinary analog line signal, which normally would drive your headphones or be fed into an amplifier, but which the tape adapter instead hooks to a magnetic coil to drive the pickup in your tape deck.	[ "When recording a signal on magnetic tape, there is a low level of \"noise\" in the background which sounds like hissing. One solution is \"low-noise\" tape which records more signal, and less \"noise\". Other solutions are to run tape at a higher speed or use a wider tape. Cassette tapes were originally designed t...
does my dog understand my emotions, and if so, how?	I did read an article some time ago (sorry, no link) that talked about how because of cohabitation for such a long time between dogs and humans, that they were beginning to be able to understand each other on an emotional level. But honestly, we don't really know. Dogs might be able to smell out pheromones, and may a...	[ "There is some evidence that humans can determine the suspected emotions of dogs while listening to barks emitted during specific situations. Humans scored the emotions of dogs performing these barks very similarly and in ways that made sense according to the situation at hand. In one example, when subjects were pl...
how does a "whammy bar", or tremolo bar, work?	The bridge is held in place by springs in the body, which allows the bridge to rock back and forth. When you do that, you gradually adjust the tension on the strings, bending the pitch up and down. If you pull off the backplate of the guitar you'll see the springs.	[ "A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eye bolts, one screwed into each end of a small metal frame, one with a left-hand thread and the other with a right-hand threa...
Question regarding quantum fluctuations and particles appearing from "nothing"	Virtual particles don't appear from nothing. They don't appear other than in calculations. Things behave _as if_ these particles were there, but they're not actually there other than as a way of visualizing a particular calculation method. (This has been explained here a number of times, and perhaps most recently over ...	[ "Quantum theory tells us that every particle exhibits wave properties. In particular, massive particles can interfere and therefore diffract. Diffraction of electrons and neutrons stood as one of the powerful arguments in favor of quantum mechanics. The wavelength associated with a particle is the de Broglie wavele...
when (and why) did the word "emoji" replace the word "emoticon"?	They're actually different. Emoticons are technically speaking pictographs created by combining type characters, like how :-) is made from a colon, hyphen, and parenthesis. An emoji (which is actually Japanese for "picture character;" the similarity to the word "emotion" is just a coincidence) is a single self-contai...	[ "An emoticon (, , rarely pronounced ), short for \"emotion icon\", also known simply as an emote, is a pictorial representation of a facial expression using characters—usually punctuation marks, numbers, and letters—to express a person's feelings or mood, or as a time-saving method. The first ASCII emoticons, codic...
why do so many medical professionals only test t4 for thyroid issues and not t3?	It's probably because the thyroid gland makes mostly T4. Most of the T3 in the body is made by peripheral conversion of T4 in other tissues (liver, kidney, brain, etc). So in essence, to check for thyroid function you'll need to check for how much T4 is getting produced.	[ "Because a single abnormal TSH level can be misleading, T3 and T4 levels must be measured in the blood to further confirm the diagnosis. When circulating in the body, T3 and T4 are bound to transport proteins. Only a small fraction of the circulating thyroid hormones are unbound or free, and thus biologically activ...
Ancient Greek sculptures were often painted. Were the colors as plain as modern recreations show them?	I'm a former conservation technician who used to work at a modest museum with a large collection of ancient/classical era sculptures, and was lucky enough to have a co-worker who did research on the polychrome techniques that were used on them. From my understanding of his work, the reason modern recreations feel "pl...	[ "Most Greek sculptures were painted in strong and bright colors; this is called \"polychromy\". The paint was frequently limited to parts depicting clothing, hair, and so on, with the skin left in the natural color of the stone or bronze, but it could also cover sculptures in their totality; female skin in marble t...
Considering the proximity of the Ireland to the UK and the strained relationship between the nations, what were the attitudes of the Irish towards the second world war, and is there any evidence of the Irish government supporting the Axis powers despite being officially neutral?	> if any actions were taken that would be considered a breach of neutrality One instance was the [Donegal Corridor](_URL_1_), which allowed Allied aircraft stationed on Lough Erne at the most westerly point in the UK to extend their range an extra hundred miles into the Atlantic by overflying a seven-mile strip of ...	[ "Irish-British co-operation was a controversial proposal for both sides, as most members of the Irish political establishment had been combatants in the Irish War of Independence between 1919 and 1921. However, because of the threat of German occupation and seizure of Ireland and especially the valuable Irish ports...
would a clock actually tick faster/slower at relativistic speed?	If you went with the clock, it would never appear to change its speed. If you stayed still here and somehow watched it with magic(?), then yes it would slow down.	[ "More advanced clocks and old mechanical clocks often have some kind of speed trimmer where one can adjust the speed of the clock and thus correct for clock drift. For instance, in pendulum clocks the clock drift can be manipulated by slightly changing the length of the pendulum.\n", "According to special relativ...
if everything leads to disorder (law of entropy), how did life form millions of years ago?	Entropy increases in a closed system. The earth is not a closed system; it is constantly receiving energy from the sun, which allows for a temporary decrease in entropy and increase in order. Without this influx of free energy, life would not be able to sustain the highly-ordered state it puts matter into.	[ "The notion of entropy as disorder has been transferred from thermodynamics to psychology by Polish psychiatrist Antoni Kępiński, who admitted being inspired by Erwin Schrödinger. In his theoretical framework devised to explain mental disorders (the information metabolism theory), the difference between living orga...
what causes the feeling of your anus retreating during moments of revulsion or distress?	The reaction has to do with the sympathetic nervous system (SNS) response. (The flight or fight response). The body sends signals to the GI tract that cause a reduction in motility, and shifts blood to the vital organs to prepare for flight or fight. So the ELI5 would be; you are a leader of a great country with your r...	[ "Emergence delirium is a condition in which emergence from general anesthesia is accompanied by psychomotor agitation. Some see a relation to pavor nocturnus while others see a relation to the excitement stage of anesthesia.\n", "Onset of effusions are sudden with no particular trigger or stimulus. Each episode l...
how high-pitched sounds break wine glasses	So each wine glass has a resonant frequency -- a frequency that when "pinged" it will vibrate at and make a familiar noise. If you match that frequency, it works in reverse, where the sound waves are causing the glass to vibrate. This is because the glass is vibrating at the same frequency that the sound waves are hi...	[ "It is this compressive stress that gives the tempered glass increased strength. This is because annealed glass, which has almost no internal stress, usually forms microscopic surface cracks, and in the absence of surface compression, any applied tension to the glass causes tension at the surface, which can drive c...
how does torrenting give you computer viruses?	Torrenting itself does not cause you to get computer viruses. However, some things that you could download may cause your computer to become infected.	[ "The best-known types of malware, viruses and worms, are known for the manner in which they spread, rather than any specific types of behavior. A computer virus is software that embeds itself in some other executable software (including the operating system itself) on the target system without the user's knowledge ...
what actually happens to food once you’ve swallowed it and how does your body “sort” what it needs to retain and what to expel as waste?	Your intestines do all the work. The cilia lining the inside of the intestine pull all the useful bits that they can into your bloodstream, such as calories, vitamins, minerals, etc.. Everything else continues on through the intestine and eventually out of the body. Waste is whatever your body can't absorb. It is act...	[ "After being swallowed, food travels down the oesophagus and is deposited in the dorsal part of the reticulum. Contractions of the reticulorumen propel and mix the recently ingested feed into the ruminal mat. The mat is a thick mass of digesta, consisting of partially degraded, long, fibrous material. Most material...
if polar bears have black skin and clear fur, why do they look white?	It's because the tube of hair isn't perfectly smooth and refracts light. Think how clear plastic gets hazy over time.	[ "The fur is soft, with dense underfur and long, coarse, thick guard hairs. The fur is not as shaggy or coarse as that of brown bears. American black bear skins can be distinguished from those of Asian black bears by the lack of a white blaze on the chest and hairier footpads. Despite their name, American black bear...
why do baby animals have a shakiness?	Mostly a lack of muscle development and motor skills (coordination). Their brains need to form new neural pathways to learn how to purposefully move.	[ "Cribbing is considered to be an abnormal, compulsive behavior or stereotypy seen in some horses, and is often labelled a stable vice. The major factors that cause cribbing include stress, stable management, genetic and gastrointestinal irritability.\n", "Olfaction plays a role in responsiveness, as most non-mate...
The origin of amino acids' names ?	Here is one page that has Chinese etymology with English etymology (5th paragraph down): _URL_0_ Aspartate Asparagus Glycine Gr. glykys (sweet) Histidine Gr. histos (tissue) Leucine Gr. leukos (white) Serine La. sericum (silk) Valine Valerian (knot) Tyrosine Gr. tyri (cheese) Arginine Gr. arginoeis (bright wh...	[ "The unity of the chemical category was recognized by Wurtz in 1865, but he gave no particular name to it. First use of the term \"amino acid\" in the English language dates from 1898, while the German term, \"Aminosäure\", was used earlier. Proteins were found to yield amino acids after enzymatic digestion or acid...
Do scientists have any opinion as to whether virtual particles occur only in vacuums or if they occur anywhere?	The only place that I have ever seen a concrete description of a 'virtual particle' is in the context of Feynman diagrams, where it is nothing more than a term in an algebraic expression. The idea is that something like an photon is a ripple or disturbance in the 'photon field'. Such photons interact with electrons ...	[ "The presence of virtual particles can be rigorously based upon the non-commutation of the quantized electromagnetic fields. Non-commutation means that although the average values of the fields vanish in a quantum vacuum, their variances do not. The term \"vacuum fluctuations\" refers to the variance of the field s...
Do Stars Attract and Repel Each Other Magnetically?	Most of the time gravity beats out the strength of their magnetic fields by a very large margin. Nevertheless, magnetic fields make stars and planets (and more!) interact with each other in very interesting ways. Relevant video: _URL_1_ At around the 2 minute mark you will be treated by a signal coming from the m...	[ "The magnetic field of a star interacts with the stellar wind. As the wind moves away from the star its rate of angular velocity slows. The magnetic field of the star interacts with the wind, which applies a drag to the stellar rotation. As a result, angular momentum is transferred from the star to the wind, and ov...
how do planets get their perfect circular formation?	Well, depends on what you call perfect. In the case of the earth, the massive size of the planet makes the mountains almost nothing in comparison. What rocks is it you are thinking about?	[ "Planets rotate at varying rates and thus may take a slightly oblate shape because of the centrifugal force. With such an oblate shape, the gravitational attraction will deviate somewhat from that of a homogeneous sphere. This phenomenon is quite noticeable for artificial Earth satellites, especially those in low o...
why can pro-divers hold their breath long? is it the lungs? how are the lungs different than non-divers?	It comes down to training. My dad used to be a diving instructor and he's comfortable swimming around the bottom of a pool for a few minutes before coming up for air. There's a couple different things at play when you condition your body for this kind of thing. First, you're used to it. There's no panic wasting oxyge...	[ "Divers who breathe from an underwater apparatus are supplied with breathing gas at ambient pressure, which results in their lungs containing gas at higher than atmospheric pressure. Divers breathing compressed air (such as when scuba diving) may suffer a pneumothorax as a result of barotrauma from ascending just w...
Has a functioning democracy ever fallen in the modern era?	"Functioning" is obviously in the eye of the beholder (is a democracy that becomes authoritarian truly "functioning"?), but Weimar Germany seems to satisfy your requirement. It had real, free elections, with multiple parties. And yet... National Socialism. (Was National Socialism more successful than the Weimar Republi...	[ "Democracy and prosperity largely went together in the 1920s. Economic disaster led to a distrust in the effectiveness of democracy and its collapse in much of Europe, including the Baltic and Balkan countries, Poland, Spain, and Portugal. Powerful expansionary dictatorships emerged in Italy, Japan, and Germany.\n"...
on average, how accurate are the drawings done by criminal sketch artists? how often are the sketches a nearly exact representation of the actual person?	They are working with a description from an eye-witness. This is literally the least accurate source of evidence used in law enforcement. The artists are good, and surprisingly fast, but garbage-in = garbage-out. Most are OK, few are excellent.	[ "The ability to quickly record impressions through sketching has found varied purposes in today's culture. Courtroom sketches record scenes and individuals in law courts. Sketches drawn to help authorities find or identify wanted people are called composite sketches. Street artists in popular tourist areas sketch p...
How do viruses modify cell behaviour?	Scientists, feel free to correct me if I’m wrong, but for the most part, symptoms of an illness aren’t caused by virus’s “rewiring” cells. Most symptoms are actually our immune response to said virus. Fever, for example, is the body attempting to denature the virus proteins. Other symptoms are caused by the death of ce...	[ "CPEs and other changes in cell morphology are only a few of the many effects by cytocidal viruses. When a cytocidal virus infects a permissive cell, the viruses kill the host cell through changes in cell morphology, in cell physiology, and the biosynthetic events that follow. These changes are necessary for effici...
What examples can we find of clergymen leading troops in Medieval Europe?	Now this is by no means my specialty but I do know of a couple specific instances. What you have to understand is that in Medieval Europe many Ecclesiastical positions, such as Bishop or Archbishop, were just as much a political and temporal appointment as they were religious or spiritual. Leading clergymen held large ...	[ "Trenck's Pandurs (, ) were a light infantry unit of the Habsburg Monarchy, raised by Baron Franz von der Trenck under a charter issued by Maria Theresa of Austria in 1741. The unit was largely composed of volunteers from the Kingdom of Slavonia and Slavonian Military Frontier, and named after security guards other...
most cigarette packs have pictures of people with their eyes covered. why is it that only both of the eyes are covered and why is it hard to recognize someone especially if you dont know them when they have their eyes covered?	Question: Where are you from where they have these on the cigarette packs? In the US, the most we get on cigarette packs are cancer warning & a suggestion to not smoke while pregnant.	[ "Studies comparing existing branded cigarette packs with plain cardboard packs bearing the name and number of cigarettes in small standard font, found plain packs to be significantly less attractive. Additionally, research in which young adults were instructed to use plain cigarette packs and subsequently asked abo...
what is the pros and cons of sleeping on the floor	Pro: The floor is always at floor level. Con: The floor would like to have a word with you, and that's usually 4:12am.	[ "According to Welton, who has a degree in architecture, \"Instead of doors, we have floors between each space. ... When guests stay over, we put a mattress down on the closet floor. ... Except for sleeping in the closet, they seem to like it.\"\n", "In some industries and work cultures sleeping at work is permitt...
what is absolute space?	Space that is not affected by any body of gravity. Whenever you're in space, every cosmic body has a a. range around it where gravity or microgravity happens. Enough distance from all bodies in space, an extremely isolated area, would be what you're thinking of. One not under the influence of any gravity.	[ "Absolute space contains no bodies. But, as such, it would not be observable. Nothing is denoted by the words \"absolute space.\" Motion and space are relative. They presuppose a relationship to some other body through which they are determined. For a wider view, it would be useful to consider motion relative to th...
why does letting air into a juice bottle make the particles that sink to the bottom mix easier when you shake it?	Imagine you have two jars of jelly beans. One is filled to the brim, the other is half full. Shake them both. Which one will get more mixed up? In order to shake up the juice it has to move around. The juice on the bottom has to be able to move up to the top and all around. But if there is no empty space, then there ...	[ "A related technique, strawpedoing, is used for containers not easily punctured such as a glass bottles. A straw is inserted into the bottle and bent around the hole. When the bottle is tilted, the beverage quickly drains and is quickly consumed. The technique increases beverage delivery since the extra hole allows...
why are school shooters always young males? is there a media bias in reporting or is there something to it?	Females are more likely to take angst out on themselves. However, the song "I don't like Mondays" by the Boomtown Rats was about a female who shot up a school, and the title was her answer as to why she did it. Also, here in Colorado, a school shooting by a female who intended to follow the Columbine example was thwa...	[ "It has long been debated that there exists a correlation between school shooting perpetrators and the type of media they consume. A popular profile for school shooters is someone who has been exposed to or enjoys playing violent video games. However, this profile is considered by many researchers to be misguided o...
where did the 911 emergency number come from in the u.s.?	According to the National Emergency Number Association (which is apparently a [thing](_URL_0_)) using 9-1-1 came about after the National Association of Fire Chiefs recommended that there be a single nationwide emergency number for fires in 1957. Over the course of the 60's the cause was taken up by the federal governm...	[ "The department makes its calls for service available to the public; it is the first American city police department to make all 911 calls available via online CrimeReports.com maps. The 911 call data is updated daily.\n", "The first 911 system was installed in Haleyville, Alabama, in February 1968, as a way to q...
how do automatic flushers work?	Typically an IR proximity sensor. They work by flashing an Infrared light (what your TV remote uses), and measuring the brightness of the reflection. When nobody is in front of them it only sees the reflection from the wall 5 feet away, when a person is there is sees the reflection from the person's shirt. These are tw...	[ "Electronic automatic flushes solve the problems of previous approaches, and are common in new installations. A passive infrared sensor identifies when the urinal has been used, by detecting when someone has stood in front of it and moved away, and then activates the flush. There usually is also a small override bu...
why are women crying and men taking down notes in every picture of kim jong-un?	Because men want to be him and women want to be with him Oh glorious leader	[ "When she made the official announcement of Kim Il-sung's death in 1994, Ri was visibly crying during the broadcast. Likewise, when she announced Kim Jong-il's death in 2011, she was seen holding back tears. Ri usually appears wearing either a pink Western-style suit or in a traditional Korean \"Joseon-ot\". She is...
what exactly is causing fraunhofer lines?	The light is absorbed by electrons. The energy is used to make the electron jump to a higher energy state (orbital). The states are always at the same energy levels in different atoms of the same element so the same frequency photon is absorbed. Different elements have their electron orbitals at different energy lev...	[ "In physics and optics, the Fraunhofer lines are a set of spectral absorption lines named after the German physicist Joseph von Fraunhofer (1787–1826). The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun.\n", "Later Bunsen and Kirchhoff found that Fraunhofer l...
how can a computer virus "infect" mundane/non-executable filetypes like .png files? how can opening an infected .png file be dangerous?	A data file doesn't runs the virus. The viewer would. Suppose you found a flaw in photo viewer or mspaint that allowed image data to overrun the buffer and execute commands. The way you could distribute the virus would be images on website. Or upload an infected image to a /r/pics and hope for front page coverage...	[ "File infectors viruses are made to infect files on the computer. File infectors spread once the user runs the infected file. The virus copies itself to locations on the computer where it can be executed; usually in RAM. The file infector will continue to infect files while granting the virus access to the infected...
why are the majority of the tallest buildings in the world located in the middle east and asia?	Tall buildings are created for two reasons. One is that there is no space to move out so you have to go up. The other is because people need to prove that they are better than other people. If you have lots of money and plenty of space as some people do in the Middle East then you build to outdo. If you have little...	[ "This list of tallest buildings in Asia ranks skyscrapers which are at least tall. The tallest building in Asia (and the tallest in the world) is Burj Khalifa, which stands which was opened on January 4, 2010 in Dubai, United Arab Emirates.\n", "Nearly three-quarters of the 50 tallest skyscrapers in the world are...
does streaming a movie online use less internet data than downloading it, if so why?	No, if you stream the entire movie from start to finish then it takes the exact same amount of data, assuming the streamed file is the same as the downloaded file (without reducing quality).	[ "Content distributed online may be streamed or downloaded, and often consists of books, films and television programs, music, software, and video games. Streaming involves downloading and using content at a user's request, or \"on-demand\", rather than allowing a user to store it permanently. In contrast, fully dow...
How powerful was the Kalmar Union compared to other European powers at the time?	Note: Most of this will be from a [previous post](_URL_0_) of mine on a similar question. The Kalmar Union was very, very weak. While it retained a semblance of a unified state (or at least a union of crowns) before the Engelbrekt rebellion in 1434, after the rebellion, it was to be very frank a dead state walking. To...	[ "The Kalmar Union (Danish/Norwegian/Swedish: \"Kalmarunionen\") was a series of personal unions (1397–1520) that united the three kingdoms of Denmark, Norway and Sweden under a single monarch. The countries had given up their sovereignty but not their independence, and diverging interests (especially Swedish dissat...
why do under inflated tires pose a greater risk of a blowout compared to recommended inflation pressure?	Underinflated tires squish down and then expand and bounce back with every rotation. This constant expansion and contraction causes heat to build up in the sidewall eventually weakening it and causing a blowout.	[ "BULLET::::- Extent of inflation - Lower pressure in tires results in more flexing of the sidewalls and higher rolling resistance. This energy conversion in the sidewalls increases resistance and can also lead to overheating and may have played a part in the infamous Ford Explorer rollover accidents.\n", "Air pre...
Insects have 6 extremities, arachnids have 8, but scorpions have 10, why are they arachnids?	the wikipedia article answers that "All arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. " the other appendages are not, and never were legs...	[ "Arachnids are further distinguished from insects by the fact they do not have antennae or wings. Their body is organized into two tagmata, called the prosoma, or cephalothorax, and the opisthosoma, or abdomen. The cephalothorax is derived from the fusion of the cephalon (head) and the thorax, and is usually covere...
what is scar tissue and why does it develop?	The simplest example I can give for how scar tissue works is for muscles. We don't have the ability to grow new muscle tissue. When your muscles get bigger, the tissue is getting larger and the connections inside are getting reinforced but the amount of cells inside hasn't really changed. So when you get a deep cut, h...	[ "Glial scar formation (gliosis) is a reactive cellular process involving astrogliosis that occurs after injury to the central nervous system. As with scarring in other organs and tissues, the glial scar is the body's mechanism to protect and begin the healing process in the nervous system.\n", "Scar tissue is com...
Why are birds, animals, and fish so much more colorful near the equator than farther away from it?	Feathers, Hair, and Scales: The first thing to notice is that feathers and scales can be a wider variety of vibrant colors than hair can. So mammals may have exciting stripes and spots, but the bright colors are going to be on reptiles, birds, and fish. Birds: The truth is, as far as birds are concerned, we ...	[ "Low (warm) latitudes contain significantly more species than high (cold) latitudes. This has been shown for many animal and plant groups, although exceptions exist (see latitudinal gradients in species diversity). An example of an exception is helminths of marine mammals, which have the greatest diversity in north...
why is it that certain commodities are untenable to produce in relatively small amounts but sustainable to the business when mass-produced?	Costs of Scale Lets do corn. To grow one stalk of corn you'll need land, water and sun. Those will be set costs/stalk. You'll also need to pay someone to wake up, tend that one stalk and harvest it when ready. That same guy will charge you only a small percentage more to do two stalks because he's already gotten...	[ "Most commodities are raw materials, basic resources, agricultural, or mining products, such as iron ore, sugar, or grains like rice and wheat. Commodities can also be mass-produced unspecialized products such as chemicals and computer memory.\n", "It is argued that commodity speculators are increasing the cost o...
why do writers seem to be able to create original concepts for tv shows, but the movie industry struggles badly to be original?	One factor is that film producers take on bigger risks and are therefore more cautious. It's no trouble for NBC to try out a bunch of different show ideas - If a show doesn't make money, they cancel it and cut their losses. Feature films are a much bigger investment, and if they don't make money, there's not much you c...	[ "Writers adapting a work for another medium (e.g., a film screenplay from a book) often make significant changes, additions to, or omissions from the original plot in the book, on the grounds that these changes were necessary to make a good film. These changes are sometimes to the dismay of fans of the original wor...
If a virus can attack our cells and re-engineer them for its own benefit, why can't the opposite occur? Or does it?	By opposite do you mean "not attack but deliver helpful things to the cells"? [if so you are thinking of viral vectors which already exist](_URL_0_) and which have a few medical applications which are being researched. If so this area is a little beyond me so you will have to wait for someone with more knowledge to tu...	[ "When a virus transforms a cell it often causes cancer by either altering the cells' existing genome or introducing additional genetic material which causes cells to uncontrollably replicate. It is rarely considered that what causes so much harm also has the capability of reversing the process and slowing the cance...

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