Split (2)

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question stringlengths 3 301	answer stringlengths 9 26.1k	context list
Why does my skin look different under different lighting conditions?	Different kinds of lights are composed of different wavelengths of light. That is some lights have more red others more blue etc. When these reflect off your skin which reflects different colors differently you get different colors. It has nothing to do with x-rays.	[ "Skin-lightening products are still prevalent in many parts of the world. This may be due to aesthetic or social-standing reasons, in areas where a lighter skin tone is considered to be a sign of wealth or beauty.\n", "Often restaurants, bars and other social gathering places will dim lighting to maximise amber s...
if the polar ice caps were developed during the last ice age, why is it so bad that they are melting now? isn’t that more of a return to where we were rather than an anomaly?	The earth doesn't give a shit what's happening to it. You do along with all the things that live on it because they've adapted to the conditions that existed after the last ice age and they don't want to adapt again to rapidly changing conditions because that means a lot of them and their offspring are going to die.	[ "Earth's polar caps have changed dramatically over the last 12,000 years. Seasonal variations of the ice caps takes place due to varied solar energy absorption as the planet or moon revolves around the Sun. Additionally, in geologic time scales, the ice caps may grow or shrink due to climate variation. If the polar...
With the massive influx of gold miners immigrating to California during its gold rush, was there enough food and water grown locally for them? Was food sent in? The miners obviously weren’t growing their own food.	Water was usually not a problem - the California Gold Country has plenty of streams and rivers. During the drier times, miners had to wait for enough flow to "wash dirt" - the method used to expose gold, but there was always enough to drink. Miners spent a lot of time hunting. I co-edited the [letters of the Grosh Bro...	[ "During the California Gold Rush there were many new immigrants who were familiar with fishing. There was a large demand for fresh food including fresh fish and shellfish among the rapidly increasing California population. Providing fresh food products were one of the most wanted and lucrative trades that developed...
How have the eyes of animals that need clear vision in and out of water evolved to cope with the varying refractive indices?	Anableps fish just have eyes that are half-and-half divided, with the top half working well out of water and the bottom working well in. It's _weird_. Seal pupils contract in the bright light of the surface, and their eyes focus better in air. In dim light (like they experience underwater) the pupils expand and th...	[ "Aquatic animals must rely entirely on their lens for both focusing and to provide almost the entire refractive power of the eye as the water-cornea interface does not have a large enough difference in indices of refraction to provide significant refractive power. As such, lenses in aquatic eyes tend to be much rou...
why, when most people orgasm, they instinctively want to vocalize their excitement/expressions?	No scientific answer here, but I can only assume it is like any other "unexpected" rush of emotions or feeling. When you step on a nail, you shriek. When you burn your hand, you shriek. Just like anonoman925 said, it is probably an involuntary reaction to too much stimulus. TL;DR: Too much stimulus = Involuntary react...	[ "Normally, a human being is able to feel pleasure from an orgasm. Upon reaching a climax, chemicals are released in the brain and motor signals are activated that will cause quick cycles of muscle contraction in the corresponding areas of both males and females. Sometimes, these signals can cause other involuntary ...
What would happen if a MAGLEV train lost power?	They have wheels.	[ "The train started moving at 09:53. 57seconds later emergency braking was recorded. Approximately half a second and 25metres later the maglev train hit the maintenance vehicle at a speed of 162km/h. The aerodynamic design of the transrapid caused it to dive under the heavy (60 tonne) maintenance vehicle, ripping of...
how would the space agencies respond if they detect an incoming asteroid large enough to cause damages?	The space agencies would report it to the public. They are in no position to keep anything like that a secret and in no position to do anything about it. The only thing they can do is warn people the best they can in the hopes that people might get to safety. The only thing anyone might be able to do about it is to lau...	[ "Sub-150m impacting asteroids would not cause global damage but are still locally catastrophic. They can, by contrast to larger ones, only be detected when they come very close to the Earth, which in most cases only happens during their final approach. Those impacts therefore will always need a constant watch and t...
how are news outlets and online articles able to be so misleading and sometimes downright wrong with their stories?	Back up a bit and imagine a government body who's job is to decide what is and isn't true, and to censor or fine news agencies that it believes are wrong. A) It would be incredibly unconstitutional, as freedom of the press is a critical right that we all have. B) Consider the possibility of abuse. Is it staffed by ...	[ "Because news organizations and websites hotly compete for viewers, there is a need for great efficiency in releasing stories to the public. News media companies broadcast stories 24 hours a day, and break the latest news in hopes of taking audience share from their competitors. News is also produced at a pace that...
why do injuries tend to hurt more in winter than in summer?	Generally speaking, we feel more pain in the cold because there is a relationship between blood circulation and nerve pain. When its cold outside and you aren’t dressed up for it, it’s very difficult for your body to heat itself because your heart rate slows in the cold as a way to survive. Our nerves are a network tha...	[ "During the summer rains are common in the late afternoon. Temperatures at this time are always very high. In the winter the arrival of polar air masses that drop and cause frost. In this time of year the relative humidity is too low, and causes discomfort to the population.\n", "Rising temperatures have two oppo...
How can moons get "captured" by planetary bodies without having done a "retrograde burn"?	Triton is Neptune's captured moon. To go into orbit, Triton still had to lose momentum somehow, just as you do a burn to get captured by Duna (or, perhaps get your orbit adjusted by Ike). In KSP, the moons and planets are all on rails, but in real space, you would transfer some of your momentum to Ike to get captured b...	[ "The mission to Meta is postponed when the crew seemingly contract a virus, later dying on (although the cause of death is subsequently revealed to be \"magnetic radiation\" emanating from nuclear waste disposal areas on the Moon's far side). With the arrival of a back-up crew, preparations for launch resume, but b...
How did the Merchant Republics in Italy arise in isolation while the rest of Europe seems steeped in Feudalism?	I'm not sure the question as it's posed will yield a satisfactory answer. Feudalism and a republic aren't mutually exclusive, as the former isn't a type of government. Besides, the republics present in Italy weren't the kinds of republics we think of today. They were essentially city-states dominated by elites and r...	[ "During the Early Middle Ages, Italy endured sociopolitical collapse and barbarian invasions, but by the 11th century, numerous rival city-states and maritime republics, mainly in the northern and central regions of Italy, rose to great prosperity through trade, commerce and banking, laying the groundwork for moder...
what causes that characteristic "grandma scent?"	technically it's described as: * floral * aldehydic (a sub category of floral, think soapy and citrusy) * musky * powdery To ELI5, it's typically Chanel No 5 with a slight baby powder note.	[ "Phantosmia (olfactory hallucinations), smelling an odor that is not actually there, and parosmia (olfactory illusions), inhaling a real odor but perceiving it as different scent than remembered, are distortions to the sense of smell (olfactory system) that, in most cases, are not caused by anything serious and usu...
what would happen if you took laxatives for an entire week?	Former laxative abuser here. Assuming you are talking about stimulant laxatives, while continuing a normal diet, the only weight loss would come from holding less waste in your body and dehydration, as your body still digests the food normally. You may experience severe muscle cramps, intestinal bloating from inflammat...	[ "Methods of prevention include gradually decreasing the dose among those who wish to stop, though it is possible for symptoms to occur with tapering. Treatment may include restarting the medication and slowly decreasing the dose. People may also be switched to the long acting antidepressant fluoxetine which can the...
if we can't see atoms how did ibm make a movie with them?	Those are Carbon Monoxide molecules. For that note, electron microscopes can operate pretty much on an atomic scale.	[ "Scientists at IBM used a scanning tunneling microscope to single out and move individual atoms which were used to make characters in \"A Boy and His Atom\". This was the tiniest scale stop-motion video made at that time.\n", "In 1980, he produced \"The Atomic Alphabet\" – a giant, poster-sized hand-colored litho...
were little old people always little or do they shrink as they age?	Most people do shrink as they get older and their bodies degenerate. The very little old people you're thinking of were short to begin with and shrivel up more.	[ "Depending on sex, genetic and environmental factors, shrinkage of stature may begin in middle age in some individuals but tends to be universal in the extremely aged. This decrease in height is due to such factors as decreased height of inter-vertebral discs because of desiccation, atrophy of soft tissues and post...
Why do some places show a long-term decline in sea level and others a rise?	Measuring sea level is actually tricky business and we're not really that good at it currently. Additionally, there's global sea level and local sea level. Global sea level is mostly affected (at least on human time scales) by the volume and temperature of the ocean (which is mostly affected by melting of surface ic...	[ "Superimposed on the global rise in sea level, is strong regional and decadal variability which may cause sea level along a particular coastline to decline with time (for example along the Canadian eastern seaboard), or to rise faster than the global average. Regions that have shown a rapid rise in sea level during...
How do we measure gas levels of an exoplanet's atmosphere?	Molecules have characteristic absorption lines in the electromagnetic spectrum. The width of these absorption lines depends on the optical thickness of the gas. Meaning, with more gas in our line of sight we will have a stronger (wider) absorption band. In order to measure the atmosphere of a planet, the planet needs...	[ "The first exoplanet whose atmospheric composition was determined is HD 209458b, a gas giant with a close orbit around a star in the constellation Pegasus. Its atmosphere is heated to temperatures over 1,000 K, and is steadily escaping into space. Hydrogen, oxygen, carbon and sulfur have been detected in the planet...
Education in post war Germany?	> How valued were their qualifications? In West Germany the folks behind the racial science of the nazi regime [kept teaching their subjects](_URL_0_) using their skills to, for example, measure the skulls of the Canary Islanders. The continuity of West German elites would be a major issue both to East Germany and in...	[ "After the defeat in World War II, the Allied occupation government set education reform as one of its primary goals, to eradicate militarist teachings and convert Japan into a pacifist democracy. Nine years of education was made mandatory, with six years in elementary education and three in junior high as an emula...
Can house flies, fruit flies, or other insects see the microscopic organisms or bacteria on stuff that we can't see?	I don't believe they can. Their eyes, [compound eyes](_URL_1_), are not intended to see high detail images because their largest threats are larger than they are (ie, a cow's tail or your hand trying to swat them). Instead, they are intended to see fast movements over a large angular resolution, they can see movements ...	[ "BULLET::::- Insect stages - \"Some larvae, nymphs and adult insects that live in freshwater.\" \"A UK-based web site with microscopic photos of various insects and other microorganisms as well as biological information.\"\n", "Micro-animals are animals so small that they can be visually observed only under a mic...
why do some people enjoy massages but it causes pain for others?	There is a huge difference between massages just for the feeling of someone rubbing your back with some more force in it and massages for relaxing muscles. I have a rather high pain tolerance, but if my muscles are really tense, having them massaged hurts a lot. I can't give you a good explanation for that (any physi...	[ "People state that they use massage because they believe that it relieves pain from musculoskeletal injuries and other causes of pain, reduces stress and enhances relaxation, rehabilitates sports injuries, decreases feelings of anxiety and depression, and increases general well being.\n", "All types of massage, i...
When was the highest % of the global population enslaved and did ancient societies with more slaves have an economic advantage over their rivals?	Follow-up: Did areas with high percentages of slaves have poor freemen angry over economic woes? It seems like there would be a shortage of paying jobs when the wealthy could simply buy slaves to fill almost every role from farmhands to pedagogues.	[ "According to the \"Encyclopedia of African History\", \"It is estimated that by the 1890s the largest slave population of the world, about 2 million people, was concentrated in the territories of the Sokoto Caliphate. The use of slave labor was extensive, especially in agriculture.\" The Anti-Slavery Society estim...
why is it easy to pick up a child that weighs 40 to 50 kilograms but very difficult to pick up a 40 to 50 kilogram weight?	The weight of the child is spread out over a large area compared to the relatively small area of the weight, making the child appear easier because it uses more muscles.	[ "For instance, the factor \"153,552,935\" (5 turns around a capstan with a coefficient of friction of 0.6) means, in theory, that a newborn baby would be capable of holding (not moving) the weight of two supercarriers (97,000 tons each, but for the baby it would be only a little more than 1 kg). The large number of...
If an Amnesia victim has lost their memories for a significant amount of time and recovers their memories, will they regain their original personality or keep the amnesia personality?	What we observe as personality is the product of variance in regions of the brain- this study, for example, shows the correlation between neuroticism and amygdala variance- _URL_0_ . An individual's personality is quite stable over the long run- see here _URL_1_ and here _URL_2_ . Amnesia, specifically in your case r...	[ "The form of amnesia that is linked with recovered memories is dissociative amnesia (formerly known as psychogenic amnesia). This results from a psychological cause, not by direct damage to the brain, and is a loss of memory of significant personal information, usually about traumatic or extremely stressful events....
can alcohol turn you into a different person?	In my experience, alcohol just loosens inhibitions. So people who "get mean" when they drink are just mean people who usually keep it together. Just like I get really sentimental when I drink; I'm a sentimental guy, it's just normally under the surface.	[ "To produce a spiritual conversion necessary for sobriety and sanity, alcoholics needed to realize that they couldn't conquer alcoholism by themselves—that surrendering to a higher power and working with another alcoholic were required. Sober alcoholics could show drinking alcoholics that it was possible to enjoy l...
Like Google Maps...but for History	The website [GeoCron](_URL_1_) is a good place to start. You can skip to any year and it will show you roughly what the world looked like. It is not entirely accurate at some points, like sometimes the author just places a circle and the name of the civilization where he may not have much information. However, it is a ...	[ "BULLET::::4. Google Maps beginning as a \"thought bubble\" and a series of random scribbles on a white board in 2004 by Noel Gordon, one of the four men who founded the Sydney-based software company Where 2 Technologies. Google Earth developed separately in the US around the same time while Google Street View foll...
modulo	Mod is basically the remainder of a division problem. 50mod7 is 1 because 50/7 = 7 with a remainder of 1. 7*7 = 49. 49 + 1 = 50. 50mod7 = 1. 39mod5 = 4 100mod12 = 4 92mod3 = 2	[ "\"Modulo\" is mathematical jargon that was introduced into mathematics in the book \"Disquisitiones Arithmeticae\" by Carl Friedrich Gauss in 1801. Given the integers \"a\", \"b\" and \"n\", the expression \"a\" ≡ \"b\" (mod \"n\") (pronounced \"\"a\" is congruent to \"b\" modulo \"n\"\") means that \"a\" − \"b\" ...
Why have no new phyla developed since the Cambrian Explosion?	This is because of the way that phyla (and other taxonomic groups) are defined. Phyla are essentially arbitrarily-defined groups, and there is no particular amount of structural or genetic divergence that causes us to classify a particular group as a phylum. However, like other taxonomic groups, scientists do strive to...	[ "In the 1970s there was already a debate about whether the emergence of the modern phyla was \"explosive\" or gradual but hidden by the shortage of Precambrian animal fossils. A re-analysis of fossils from the Burgess Shale lagerstätte increased interest in the issue when it revealed animals, such as \"Opabinia\", ...
Before French and Latin, has there been any other lingua franca?	Greek! The Romans themselves were Grekophiles, and most well-educated Romans would be expected to know Greek. Greek was the lingua franca of the eastern Mediterranean (and was also widely spoken in many western mediteranean settlements like Massalia and Emporion) and continued to be the primary language of communicatio...	[ "The term \"lingua franca\" derives from Mediterranean Lingua Franca, the pidgin language that people around the Levant and the eastern Mediterranean Sea used as the main language of commerce and diplomacy from late medieval times, especially during the Renaissance era, to the 18th century. At that time, Italian-sp...
Why does it spread germs/illnesses to leave a bathroom with hands unwashed, yet oral-genital contact is not regarded as a surefire way to get the same illnesses?	Washing your hands after using the bathroom is not just about the germs gathered during the time using the bathroom. Ingraining that habit into people while they are at a sink with water gets them to clean away other germs they may have picked up without having to make a special trip to wash. Human fecal matter is th...	[ "General sanitary hygiene is the most important method of preventing sapovirus. This can be done by thoroughly washing hands after using the restroom and before eating/preparing food. Contaminated surfaces should be cleaned with disinfectant and or solutions containing bleach. Other preventative measures include av...
how can i invest and grow my money without knowing how to invest?	The market overall is down right now, so it makes sense that you lost some money. The three main things you need to know: Investment gains are slow; it wouldn't be a surprise for it to take a year or so before you make $10 on $500. The safest way to invest is to diversity; buying shares of an index fund or an ETF will ...	[ "By investing \"directly\" in an institution, rather than purchasing stock, an investor is able to create a greater social impact: money spent purchasing stock in the secondary market accrues to the stock's previous owner and may not generate social good, while money invested in a community institution is put to wo...
what is the difference between the various semi-automatic gun mechanisms?	The most simple form is straight blowback Straight blowback works by having an unlocked bolt behind the round in the chamber. when the gun is fired the gas pressure exerts a force on the bolt and it is forced away from the chamber. As it moves rearwards the empty case is pulled out. When the bolt reaches the rear of i...	[ "The language surrounding automatic, semi-automatic, self-loading, etc., often causes confusion due to differences in technical usage between different countries and differences in popular usage. For example, the term \"automatic pistol\" technically refers to a machine pistol which is capable of firing multiple ro...
sound. yes i get that is a wave but how is a wave able to encode so much variety (voice, instruments, sound effects)?	If it were a single wave, it would not convey so much. But sounds like you describe are a series of waves, spread out over time and interpreted by an excellent computer -- your brain.	[ "Wave Sequences were first introduced on Korg's Wavestation synthesizer, released in 1990. Wave Sequences allow a single note to play through a list of samples, one after the other, with or without crossfades, with other associated parameters changing for each sample, as listed below. This can create smooth, evolvi...
Is this any intuitive way to think about normal distribution function ?	The gaussian distribution is e^-x^2. It is the heart to the shape that is called the normal distribution. The pis, the sigmas, the various other values are just adjustments. The constant term in front of the exponential is just a multiplier to make the area under the curve equivalent to 1 (so that the sum of the prob...	[ "In mathematics, a distribution function is a real function in measure theory. From every measure on the algebra of Borel sets of real numbers, a distribution function can be constructed, which reflects some of the properties of this measure. Distribution functions (in the sense of measure theory) are a generalizat...
How different were the peoples of northern Spain culturally, linguistically etc from people in southern Spain during the rule of the Umayyads?	So what you're talking about here is a really long period. I happen to have a decent source that discusses this topic at length in some parts, but I might wander a bit here and there. So to the beginning. If we look at the early days of conquests in the 8th century, even then the actual conquering force of al-Andalus ...	[ "In time Islamic migrants from places as diverse as North Africa to Yemen and Syria and Iran invaded territories in the Iberian peninsula. The Islamic rulers called the Iberian peninsula \"Al-Andalus\". That was the root for the name of the present-day region of Andalusia, the southernmost region of Spain.\n", "A...
This Week's Theme: The 14th Century, AD	Current: 14th Century AD On Deck: Resistance and Conformity In the Hole: Propaganda	[ "The 15th century is part of the High Middle Ages, the period from the coronation of Charlemagne in 800 to the close of the 15th century, which saw the fall of Constantinople (1453), the end of the Hundred Years War (1453), the discovery of the New World (1492), and thereafter the Protestant Reformation (1515). It ...
Do the descendants of the major Japanese clans (Tokugawa, Oda, etc) still have influence or command respect? Are their any clans that still 'exist', so to speak?	After the Meiji restoration, the clans were [converted into noble families](_URL_1_), along the lines of European nobility. Their domains were [converted into prefectures](_URL_0_), with a centralized authority, though they were allowed to keep 10% of the province's revenue. If you're interested in this time period, th...	[ "The was a powerful \"daimyō\" family of Japan. They nominally descended from Emperor Seiwa (850–880) and were a branch of the Minamoto clan (Seiwa Genji) by the Nitta clan. The early history of this clan remains a mystery. Members of the clan ruled Japan as \"shōguns\" from 1603 to 1867.\n", "The was a prominent...
Ionized water	Could you be more specific? In general, anyone claiming to make "ionized" water is running a scam, but depending on what device they're selling, it may produce any of a number of things.	[ "Although the exact ion formation mechanism is not clear, water can be ionized directly by Penning ionization. Another proposal is that water is ionized by the same mechanism that has been proposed for atmospheric pressure chemical ionization\n", "A water ionizer (also known as an alkaline ionizer) is a home appl...
why do i get these rashes on my throat after i've shaved?	A few years back I switched to a brush+lather shave and never looked back. Canned shave gel is total garbage. This made all the difference in the world to me. That and picking up a safety razor.	[ "After a hair has been shaved, it begins to grow back. Curly hair tends to curl into the skin instead of straight out the follicle, leading to an inflammation reaction. PFB can make the skin look itchy and red, and in some cases, it can even look like pimples. These inflamed papules or pustules can form especially ...
what is tickling? why do we have places like on our sides and armpits that makes us laugh out of panic when there is no real danger?	This is just a short explanation based on the video at the end of my comment: Small tickling (like from a feather) is called knismesis. It makes you scratch/touch places. This is to make us get rigd of insects, spiders and other stuff we don't want to have on our skin. Many animals are ticklish too so it shows us our ...	[ "A third, hybrid hypothesis, has suggested that tickling encourages the development of combat skills. Most tickling is done by parents, siblings and friends and is often a type of rough-and-tumble play, during which time children often develop defensive and combat moves. Although people generally make movements to ...
Why does some music just sound... Old? Is it recording quality, or were instruments constructed differently?	Can you shoot some examples of what recorded music you're thinking of?	[ "Vintage musical equipment is older music gear, including instruments, amplifiers and speakers, sound recording equipment and effects pedals, sought after, maintained and used by record producers, audio engineers and musicians who are interested in historical music genres. While any piece of equipment of sufficient...
why is nuclear fusion considered the "holy grail" of nuclear power compared to fission?	> but I fail to understand why fusion is safer Because it requires extremely specific circumstances to occur. The second those conditions are lost, the reaction can't physically happen. If you don't have enough heat in the system, the fuel won't have enough energy in it to fuse. > cleaner It doesn't use radioactiv...	[ "As a source of power, nuclear fusion is expected to have several theoretical advantages over fission. These include reduced radioactivity in operation and little high-level nuclear waste, ample fuel supplies, and increased safety. However, achieving the necessary temperature/pressure/duration combination has prove...
why are white americans not called european americans? similar to asian americans and african americans.	We should not use any of these segregating terms. We should simply use the term Americans instead.	[ "The term is used by some to emphasize the European cultural and geographical ancestral origins of Americans, in the same way as is done for African Americans and Asian Americans. A European American awareness is still notable because 90% of the respondents classified as white in the U.S. Census knew their European...
why were trains invented so much earlier than cars? it seems like trains would be harder to manufacture and create.	Imagine a car running a steam engine, burning coal in a furnace, using the heat to heat up water, pump that water, and turn the wheels. Also storage for coal to be able to go hundreds of miles. This is easier to go in a 200 tonne stab of metal than a tiny box with people inside. Also no need for steering, just tur...	[ "In the early 20th century, when automobiles were still new technology, their production levels were low enough that they could be shipped in sufficient quantities in boxcars. Two to four automobiles would usually fit into one boxcar. But as the automobile industry grew in size, railroads found that they needed to ...
what's the difference between cs (computer science), cis (computer information science, and it (information technology?	Computer Science : It’s the science (mathematics) of how computers inherently work. It would have an answer to this question: If I had a bunch of random numbers, what would be the fastest way to sort them, is it the fastest way? And why is it the fastest way. It often requires writing code but only to verify and qu...	[ "Information and computer science (ICS) or computer and information science (CIS) (plural forms, i.e., \"sciences\", may also be used) is a field that emphasizes \"both\" computing and informatics, upholding the strong association between the fields of information sciences and computer sciences and treating compute...
Historical Fencing in the US of A	Matthew J. O'Rourke, a captain of volunteers on the Union side during the Civil War, published a treatise on the use of the saber in 1872, which was adopted as the Army's standard. You can get a free ebook of the manual here: _URL_0_ The first half of the the book is "the Manual," regulations for how to draw a sword on...	[ "Many people self-identify as classical fencers, but do not share the concept of classical fencing described in this article, preferring the early to mid-20th-century style of competitive fencing (which, in the United States, was formalized and governed by the American Fencing League, or AFL) to the more classical ...
In high and late medieval Europe, German & Yiddish-speaking Jews had very high rates of literacy. However, was this isolated to Hebrew literature or could most Jewish people also read the Latin alphabet?	Gotz Aly (Why the Germans, why the Jews) explained that having extremely limited opportunities, European Jews invested heavily in and prioritized education. Whether their own religious education or secular education. As a result, they often had a mastery or at least understanding of multiple languages. Being persecute...	[ "By the Middle Ages, large numbers of Jews lived in the Holy Roman Empire and had assimilated into German culture, including many Jews who had previously assimilated into French culture and had spoken a mixed Judeo-French language. Upon assimilating into German culture, the Jewish German peoples incorporated major ...
what does the death of kim jong-il mean for north korea/the rest of the world?	It's very hard to say at this point. There is very little information out about Kim Jong-un and we have no clue whether the regime will be better or worse under him. One of the many problems that analysts have outlined is that it isn't just the outside world that is unfamiliar with Kim Jong-un. Most North Koreans, outs...	[ "Kim Jong-il's funeral took place on 28 December in Pyongyang, with a mourning period lasting until the following day. South Korea's military was immediately put on alert after the announcement and its National Security Council convened for an emergency meeting, out of concern that political jockeying in North Kore...
what the suds in dish soap do and how they work.	Dish soap is made out of special molecules are both polar (slight charge) and non-polar. This property allows them to form a microscopic "bubble" called a [micelle](_URL_0_) around non-polar molecules (such as fat and oils) which can then be dissolved in water. The reason it is so hard to get things like oil off of you...	[ "A soap dish is a shallow, open container or platform where a bar of soap may be placed to dry after use. Soap dishes are usually located in or near a sink, shower, or bathtub. Most soap dishes are made from waterproof materials such as plastic, ceramic, metal, or glass, though some are made from bamboo. A china sa...
Atlatls VS bows in the Americas	[This post](_URL_0_) has it that bows and arrows emerged between 3-4 thousand years ago, probably independently, in a number of locations in North America. To my knowledge, atlatls were widely spread throughout North America both before and after bows were in use.	[ "The spear-thrower was used by early Americans as well. It may have been introduced to America during the immigration across the Bering Land Bridge, and despite the later introduction of the bow and arrow, atlatl use was widespread at the time of first European contact. Atlatls are represented in the art of multipl...
What is the limiting factor in human eyesight?	At some point, the eye will be diffraction limited (see Rayleigh Criterion and Angular Resolution [here](_URL_0_)). Even if your eye was physically perfect/ideal in every way, your vision is still limited by the size of the circular aperture of the eye. I actually did a presentation on this for a lower division phy...	[ "In anatomy, an eyestalk (sometimes spelled as eye stalk or known as an ommatophore) is a protrusion that extends the eye away from the body, giving the eye a better field of vision. It is a common feature in nature and frequently appears in fiction.\n", "The external limiting membrane (or outer limiting membrane...
is it true that the 1960's-1970's middle east was super civilized and progressive, and if so, what the hell happened?	Pakistani here! In the 60s, we were very progressive. Free market economy, thriving banking sector, largely secularist (Alcohol, clubbing and everything was part of society). Then the cold war happened. In the mid 70s Prime Minister Bhutto, a socialist, was forced to outlaw alcohol by pressure from the Islamic clergy...	[ "The modern Middle East was shaped by three things: departure of European powers, the founding of Israel, and the growing importance of the oil industry. These developments led increased U.S. involvement in Middle East. The United States was the ultimate guarantor of the region's stability as well as the dominant f...
What are some good books about US Armored Forces in WWII	More generally Band of Brothers and Citizen Soldier are two great books if you want more of a narrative than a by-the-numbers historical account. Do realize that with books by Steven Ambrose you would do well to research what may or may not have been plagiarized. The core message is still solid even if Ambrose had stic...	[ "At the end of World War II, two 6th Armored Division G3 officers, Majors Paul L. Bogen and Clyde J. Burke along with Aide-de-Camp Captain Cyrus R. Shockey, compiled a \"Combat Record of the Sixth Armored Division in the European Theatre of Operations 18 July 1944-8 May 1945\". The official history by George F. Hof...
I'm interested in the history of the addition of Hawaii to the United States. What was the reasoning behind it? Did the people accept it with open arms?	Hawaii was a major importer of sugar to the United States in the mid and late 19th century. However, after the McKinley Tariff (1890), which raised taxes on imports significantly, the sugar growers realized that they could bypass the costly tariff by becoming annexed into the US. They staged a rebellion against the loc...	[ "Upon the inauguration of William McKinley as the 25th President of the United States on March 4, 1897, the Republic of Hawaii resumed negotiations for annexation, which continued into the summer of 1898. In April 1898, the United States went to war with Spain, and Republic of Hawaii declared its neutrality. In pra...
why do (most) countries have a tomb of the unknown soldier?	It's mainly just a respect thing. War leaves a lot of dead bodies that no one can identify. I think the British or the French started the tradition around WW1.	[ "Many countries have buried an unidentified soldier (or other member of the military) in a prominent location as a form of respect for all unidentified war dead. The United Kingdom's Tomb of the Unknown Warrior is in Westminster Abbey, France's is buried underneath the Arc de Triomphe, Italy's is buried in the Monu...
the perceived animosity of the nypd towards bill de blasio.	The mayor has repeatedly come across as being in support of those who are angry with the police, even in instances where that anger is not justified. The mayor isn't seen as being on the side of his police force.	[ "Under Mayor Bloomberg, Kelly's NYPD also incurred criticism for its handling of the protests surrounding the 2004 Republican National Convention, which resulted in the City of New York having to pay out millions in settlement of lawsuits for false arrest and civil rights violations, as well as for its rough treatm...
Where does the energy go when particle-antiparticle pairs spontaneously appear and annihilate?	The energy doesn't go anywhere, because there was zero energy to begin with and zero energy after. The particle-antiparticle pairs you're referring to are called virtual particles. They aren't real particles, and they don't actually exist. They're mathematical tools that are used in calculations, but they fail to ha...	[ "If a particle and antiparticle are in the appropriate quantum states, then they can annihilate each other and produce other particles. Reactions such as + → + (the two-photon annihilation of an electron-positron pair) are an example. The single-photon annihilation of an electron-positron pair, + → , cannot ...
How many molecules wide are the sharpest blades?	Obisidian blades can be mere molecules thick, the preferred tool of optometrists. I'm not sure if its the SHARPEST but it is practically impossible to not cut yourself on one Source: History of art professor, the first hand experience. [and wikipedia as source](_URL_0_) Edit: as others pointed out its actually Ophtha...	[ "Saw blades come in many different thicknesses and the choice of blade will depend on the material being sawn and nature of the work being done. For very fine delicate work, and for cutting very thin material use a finer blade, and for general purpose cutting a heavier blade. Saw blades have a range of sizes, from ...
how is it possible to have a hole in your heart, and not die of internal bleeding?	Its not an expression, it is literally referring to a hole somewhere in the heart that there isn't supposed to be. Now bear in mind this doesn't mean there's a hole straight through the heart, or that the hole leads to the exterior of the heart. What it usually entails is that there is a defect in the walls that separa...	[ "When there are holes in the septum that divide the four chambers of the heart the oxygen-rich blood and oxygen-poor blood mix this creates more stress on the heart to pump blood to where oxygen is needed. As a result, you get enlargement of the heart, heart failure (being unable to adequately supply body with need...
Is there a scientific reason that the hexagon is 'nature's shape'?	Hexagons represent the shape with the lowest possible energy when nested / packed. If you imagine a soap bubble, it pulls itself into a sphere for the same reason - the sphere is the least possible surface area which contains the maximum volume - the lowest energy shape. If you subsequently nest soap bubbles together...	[ "Very similar to the Spiral Chart, the Hexagon Chart is also a matrix of consecutive natural numbers, but the difference is that it starts with 0 in the central point, and the numbers spiral out in the form of a hexagon instead a square. The spiral direction in Gann's original course is also counterclockwise, becau...
how do airlines know the exact departure and arrival times for flights months out in advance?	Plane routes don't change often. The same flight goes from NYC to LA everyday and comes back everyday. To do the same thing tomorrow. Pretty much only time schedules change is when some airline starts a new route. Or shuts down a route	[ "Time of arrival (ToA, also time of flight) is the amount of time a signal takes to propagate from transmitter to receiver. Because the signal propagation rate is constant and known (ignoring differences in mediums) the travel time of a signal can be used to directly calculate distance. Multiple measurements can be...
why are all of our fingers different lengths?	[I made a quick video to answer your question](_URL_0_) If you prefer reading here is what I ran over: - That it's due to evolution, we need it to improve our grip. We started using tools millions of years ago and we need the grip to use them! We still need the grip to date obviously, for items such as pens, tools an...	[ "In the classical Akkadian Empire system instituted in about 2250 BC during the reign of Naram-Sin, the finger was one-thirtieth of a cubit length. The cubit was equivalent to approximately 497 mm, so the finger was equal to about 17 mm. Basic length was used in architecture and field division. \n", "The digit or...
During the decolonization of Africa, was there any serious discussion/suggestions for the redrawing of colonial borders? (3rd try)	I touched on this answer in [this thread](_URL_3_), and I discussed the [OAU charter and Cairo Declaration here](_URL_2_). [This thread](_URL_4_) focuses mainly on the formation and adjustment of borders in french Africa, but I do touch on origins of anti-colonial nationalism in the WW2 era. Those answers amount to th...	[ "The decolonisation of Africa took place in the mid-to-late 1950s and 1960s, with sudden and radical regime changes on the continent as colonial governments made the transition to independent states; this was often quite unorganized and marred with violence and political turmoil. There was widespread unrest and org...
What did Lucifer, as a Roman God, represented for the people of Rome?	Lucifer was not a Roman god.	[ "In the Middle Ages, the Cathars, practitioners of a dualistic religion, were accused of worshipping Satan by the Catholic Church. Pope Gregory IX stated in his work \"Vox in Rama\" that the Cathars believed that God had erred in casting Lucifer out of heaven and that Lucifer would return to reward his faithful. On...
Plate Tectonics on Venus	Interesting explanation here: _URL_0_ Essentially, it doesn't have Earth like plate tectonics because it's too hot. It's a definitions issue, not a process one.	[ "BULLET::::- The typical signs of terrestrial plate tectonics - continental drift and basin floor spreading - are not evident on Venus. The planet's tectonics is dominated by a system of global rift zones and numerous broad, low domical structures called coronae, produced by the upwelling and subsidence of magma fr...
why do anesthetic needles hurt so much when numbing a nerve?	Because they fairly directly poke the nerve (or very close to it) before injecting. Poking a nerve directly tends to hurt.	[ "Local anesthetic toxicity is indicated by numbness and tingling around the mouth, metallic taste, or ringing in the ears. Additionally, this may lead to seizures, arrhythmias, and may progress to cardiac arrest. This reaction may stem from an allergy, excessive dose, or intravascular injection. Other complications...
why do addicts of hard drugs tend to lose many of their teeth?	Drug addicts don't typically have the best hygiene. Depending on the drug of choice, they may have no appetite and end up malnourished.	[ "The intense desire to recapture the initial high is what is so addictive for many users. On the other hand, Reinarman et al. wrote that the nature of crack addiction depends on the social context in which it is used and the psychological characteristics of users, pointing out that many heavy crack users can go for...
Why are bike wheels so big?	It is partly because mechanically it offers the opportunity of higher road speeds on a pedal bike without having to pedal furiously or without the need of excessive gearing. Also, larger wheels traditionally were used before bike had suspension to try to smooth out the uneven roads that bikes were used on when they wer...	[ "Following the growing trend in 29-inch wheels, there have been other trends in the mountain biking community involving tire size. One of the more prevalent is the new, somewhat esoteric and exotic 650B (27.5 inch) wheelsize, based on the obscure wheel size for touring road bikes. Some riders prefer to have a large...
why do public women's toilets have lids if they're never going to be lifted up?	Standard parts for efficient manufacturing.	[ "Toilet seats often have a lid. This lid is frequently left open. It can be closed to prevent small items from falling in, to reduce odors, for aesthetic purposes or to provide a chair in the toilet room. Some people also close the lid to prevent the spread of aerosols on flushing (\"toilet plume\").\n", "BULLET:...
what is isis trying to accomplish with the beheading incidents and how do they release the videos?	ISIS believes that they can punish the US for conducting air strikes against itself, by executing American citizens who are so unfortunate as to fall into their hands, and that when America sees that it has been punished for its crimes, it will feel suitably remorseful and will then refrain from its criminal activities...	[ "In addition to beheading videos, ISIS has released videos of their members doing nonviolent acts. For example, Imran Awan described one such instance in his article \"Cyber-Extremism: Isis and the Power of Social Media\" where one video showed members of the Islamic State were seen helping people and visiting hosp...
how do frogs, toads and other amphibians know how and where to find new bodies of water?	Amphibians explore and migrate during cool moist weather. They can cover a lot of distance that way, especially if they can find damp places to take shelter in between stages of their journey. Most animals (including us) are also perfectly capable of smelling water from a good distance. Wind blowing across a body of w...	[ "The first \"Brachycephalus\" species was identified in 1824, but most of the frog species were discovered since the year 2000. The discovery of new frog species is difficult. Field work requires climbing steep mountain trails to the sites where the frogs live.\n", "The frog was originally discovered by Dr. Willi...
How easy was to get new identity and "vanish" at the end of WW2?	Follow up: If there were people that did this and were caught, what would the punishment be?	[ "That list has been adapted in that the persons who simply disappeared after the war, who were eliminated by the resistance during the war or who committed suicide before being convicted, have been taken off the list.\n", "The surnames of those noted lost in the First World War are Lacey, Hind, Middleton, Herapat...
how effective medical marijuana is. is it actually useful compared to other meds? or is it just used to get people to see the good side to marijuana	Hey! I have Crohn's disease, which is essentially a disease of the gastrointestinal system that has varying effects on the people afflicted. For me, when my Crohn's "flares" as my wife calls it, I am unable to properly digest anything. As a result, I have severe diarrhea, stomach cramps, and a loss of appetite. These s...	[ "In 2003, the American Academy of Ophthalmology released a position statement stating that cannabis was not more effective than prescription medications. Furthermore, no scientific evidence has been found that demonstrates increased benefits and/or diminished risks of cannabis use to treat glaucoma compared with th...
To what extent can parents' DNA be reverse-engineered from their child's DNA?	research engineer here: A haplotype (haploid genotype) is a group of genes in an organism that are inherited together from a single parent. As the human genome consists of two homologous sets of chromosomes, understanding the true genetic makeup of an individual requires delineation of the maternal and paternal copie...	[ "The replication of damaged DNA before cell division can lead to the incorporation of wrong bases opposite damaged ones. Daughter cells that inherit these wrong bases carry mutations from which the original DNA sequence is unrecoverable (except in the rare case of a back mutation, for example, through gene conversi...
If you shine a white light through a blue filter, does it actually change the wavelength of the color?	Filters remove certain colors from the light beam. White light has all the colors mixed together: the blue filter removes everything but blue. If the color isn't there to begin with, the filter can't add it. You can test this by getting a red laser pointer (which is only red) and shining it through a colored liq...	[ "The filter on a colorimeter must be set to red if the liquid is blue. The size of the filter initially chosen for the colorimeter is extremely important, as the wavelength of light that is transmitted by the colorimeter has to be same as that absorbed by the substance.\n", "The blue filter is centered around 450...
Do certain activities increase/decrease brain activity during sleep?	One of the main functions of sleep and dreaming is to consolidate (new) memories and reorganise the brain's neural architecture accordingly. Because of this, dream experience seems to have a strong relation with what you have experienced and encoded in waking life. It is not entirely clear if there are reliable caus...	[ "The function of sleep is not fully understood; however, there is evidence that sleep enhances the clearance of metabolic waste products, some of which are potentially neurotoxic, from the brain and may also permit repair. Evidence suggests that the increased clearance of metabolic waste during sleep occurs via inc...
how do you enter a gas giant?	> but is there a uniform boundary or is it just Space and then the planet kinda just "starts"? Atmospheres tail off roughly exponentially as you go up in height. Earth's does too - there's no sharp "you're suddenly in space" line for Earth, either.	[ "Within the gas giant is the Helix, a Suliban aggregate structure composed of hundreds of Suliban ships, which the \"Enterprise\" crew scan to find Klaang. Using the grappler, \"Enterprise\" successfully grabs an attacking Suliban ship, the pilot ejecting. After studying the captured ship and its controls, Archer a...
what does the f/stop in a camera do?	Building on the other two responses... The F/stop works with the shutter speed to get the appropriate amount of light on the film. The smaller the F/stop number, the more light is being let in at once, and the larger fraction on the shutter speed, the longer time the light is allowed to reach the film. So if you tur...	[ "The stop-down lever at the right-hand camera front also operates the self-timer. Pushing the lever towards the lens activates the stop down match-needle meter, while pulling in the opposite direction winds the timer. As with the Canon FX and FP, the camera back is opened turning a key at the base. The film speed i...
Is there such a thing as space coordinates?	There aren't any absolute coordinates in the universe. However, you can broadcast our location relative other parts of the universe. For example, if you wanted to send a message within our [local group](_URL_1_), such as communicating our location to a civilization in the Andromeda galaxy, you could send our galaxy's l...	[ "Coordinates systems are often used to specify the position of a point, but they may also be used to specify the position of more complex figures such as lines, planes, circles or spheres. For example, Plücker coordinates are used to determine the position of a line in space. When there is a need, the type of figur...
What is the probability of a couple having identical non-twins?	Here's [my answer](_URL_0_) to this question from about a month ago. The figures I give are for the probability of being unrelated (or rather of being substantially less related than the expectation), but the calculation is symmetric, so those probabilities are the same for the other half of the distribution. It's not...	[ "More generally, it applies to any exchangeable sequence—it only relies on the fact that for any pair, 01 and 10 are \"equally\" likely: for independent trials, these have probabilities formula_105, while for an exchangeable sequence the probability may be more complicated, but both are equally likely.\n", "Addit...
why do people stand along roads holding signs to promote sales of some stores? (e.g. furniture stores, stores going out of business, etc.,.) is there a law against posting signs?	Generally yes it is illegal in many towns to post signs and flyers because no one ever removes the signs later and they usually become trash in the streets, but that is not why they do it. They do it because people like you notice them. How many signs and posters do you stop to read that are posted to telephone poles a...	[ "There have often been complaints about road signs and infrastructure not being up to date in some parts of the country, with a traffic report in 2008 disclosing that local governments in many cases have not addressed damaged, vanished or outdated road regulatory signs. In Lahore alone, the report estimated that at...
how / why water goes "bad" when you leave it out but is fine in bottles?	Actually, water in plastic bottles CAN and does go bad (look at the expiration date!) Exposed water will have dust settle in it, it will have smells and other floating stuff fall in to it, etc. Bacteria might get in it and start to multiply. Bottled water will stay fresher longer, but since plastic does have very sma...	[ "Reusable bottles can hold bacteria. Drinking from a reusable bottle can transfer bacteria from a person's mouth to the beverage it contains, which can contaminate both bottle and water. Contamination can cause bacterial or fungal growth in the liquid while it's stored. It is recommend that users clean reusable dri...
why does a doughnut get nice and fluffy after 20 seconds in the microwave but hard after 40 seconds?	Microwaves act by making water molecules bounce around faster (increasing its kinetics) The energy from this movement is released through the form of heat and it is dispersed evenly through the body of what you are heating. If you overdo it you just completely dry out the object of the microwaves. Your doughnut ...	[ "The production of puff pastry dough can be time-consuming, because it must be kept at a temperature of approximately 16 °C (60 °F) to keep shortening from becoming runny, and must rest in between folds to allow gluten strands time to link up and thus retain layering.\n", "Many people believe it was the Dutch who...
why do i have horrendous farts after a night of drinking?	You have bugs in your stomach that like to eat carbohydrates. When they eat they produce gas. Alcohol contains carbs. The diarrhea is probably a side effect of not eating as well as you should while drinking. If this happens every time you drink, you should see a doctor.	[ "After drinking it, the person will get cramps and loose motion are caused which ultimately will clean the bowels. This was a primitive method for purging and treating intestinal cleansing as well as worms. Now this practice is almost given up owing to access to health facility of allopathic medicines and lethargy ...
how are digital devices functional in an mri room? how do they operate the mri in that strong magnetic field?	For the most part, magnetic fields are not as bad to electronics as people would lead you to believe. Specifically, magnetism isn't an important thing in the operation of electronics, and it doesn't somehow stop them from working. Really traditional hard drives are the only thing in a modern computer that has any meani...	[ "An MRI gantry remains fixed, and contains strong electromagnets and radio receivers that manipulate hydrogen atoms in the human body via proton nuclear magnetic resonance. The machine then receives and processes the signals given off by the hydrogen atoms in order to produce a 3D image of the interior of the patie...
Stem Cells for Rejuvenation	Cells from your body (eg your skin) can be manipulated and turned into [induced pluripotent stem cells](_URL_1_). These cells are, in theory, stem cells that can become any other type of cell in your body. Under the proper conditions, they can be induced to become neurons, blood cells, or any other cell type. In the...	[ "Under defined conditions, embryonic stem cells are capable of self-renewing indefinitely in an undifferentiated state. Self-renewal conditions must prevent the cells from clumping and maintain an environment that supports an unspecialized state. Typically this is done in the lab with media containing serum and leu...
when an app crashes and i send a report, what exactly does that do, and how is it used?	It tells the developer that the app has crashed, first of all. But it can also tell the developer what you were doing, what screen you were viewing, what data you were using, what route you took to get to that screen, and so on. All of this can help fix the bug. Obviously the developer needs to know what screen you'r...	[ "Crash Reporting creates detailed reports of the errors in the app. Errors are grouped into clusters of similar stack traces and triaged by the severity of impact on app users. In addition to automatic reports, the developer can log custom events to help capture the steps leading up to a crash. Before acquiring Cra...
Why do trash cans smell even after they've been washed?	I can only speak in generalities -- but I think it's pretty reasonable that those smell molecules have simply diffused into the plastic. At the molecular level, the plastic will be quite porous.	[ "Some types of cans may have interior coatings containing chemicals such as Bisphenol A. Reusing containers originally holding paints and other types of chemicals may be injurious to the health of the user if the can is not properly cleaned and decontaminated.\n", "Similarly, trash cans that are used inside and t...
why does closing a credit card account hurt your credit?	Actually, to build great credit you want to have as much available credit (and debt) as possible. Your credit score is a reflection of how trustworthy you are with credit. It's based on how reliably you pay off your debt, not how little debt you have. If you have a lot of credit cards, you use them all, and y...	[ "A simple solution to this problem is to call the credit card company, request a new card with a different account number, and cancel the previous account. They will transfer the debt amount from the old account to the new account. This makes companies that have the credit card information unable to continue chargi...
why aren't there bigger pushes to abandon the political party system?	Originally there were no parties. Like- minded individuals formed parties organically. If they got rid of the current parties the only thing that would happen is new ones would form, officially or othrwise it doesn't matter.	[ "By-elections can be crucial when the ruling party has only a small majority. In parliamentary systems, party discipline is often so strong that the governing party can only lose a vote of no confidence after losing enough by-elections for it to become a minority government. Examples are the Labour government of Ja...
where does energy go in a short-circuited battery?	It all turns into heat. Short out a battery, and it'll heat up and get warm, hot, or even on fire. All batteries have internal resistance. That is to say, the inside of the battery isn't superconducting. So even if you had a superconducting wire shorting the battery, it would still get hot.	[ "A secondary cell, commonly referred to as a \"rechargeable battery\" is an electrochemical cell that can be run as both a galvanic cell or as an electrolytic cell. This is used as a convenient way to store electricity, when current flows one way the levels of one or more chemicals build up (charging), while it is ...
why does falling down hurt more/ longer when you get older	As you get older, you get taller. As you get taller, more of your body gets farther away from the ground. As they get farther from the ground, they have farther to fall. Knock a three year old over. Then hold that same three year old up to where his head is level with yours and drop him. Don't actually do that unle...	[ "Falls in older adults are a significant cause of morbidity and mortality and are an important class of preventable injuries. The cause of falling in old age is often multifactorial, and may require a multidisciplinary approach both to treat any injuries sustained and to prevent future falls. Falls include dropping...
why are salmon from the pacific prone to parasites while salmon from the atlantic safe to eat raw?	I don't believe this is actually a thing? Atlantic Salmon also frequently have warnings put out about parasite risks. [The NHS publishes warnings in the UK](_URL_0_) about it. Now you can get sushi-grade fish, of course, but that's fish that has been flash frozen to kill any potential parasites in the fish. That can ...	[ "Many Atlantic salmon escape from cages at sea. Those salmon that further breed tend to lessen the genetic diversity of the species leading to lower survival rates, and lower catch rates. On the West Coast of North America, the non-native salmon could be an invasive threat, especially in Alaska and parts of Canada....
how can a spinning top stay upright while it's rotating?	When something spins, it has inertia just like an automobile and just like an automobile, it is very easy to move it in certain directions in respect to the direction of the movement and difficult in other directions. The trick is that with a top, the inertia isn't all in one direction, it is in all directions along a ...	[ "When a tippe top is spun at a high angular velocity, its stem slowly tilts downwards more and more until it suddenly lifts the body of the spinning top off the ground, with the stem now pointing downward. Eventually, as the top's spinning rate slows, it loses stability and eventually topples over, like an ordinary...
does my breastmilk have healthier properties if i eat healthier food?	Regarding healthy and unhealthy fats: generally speaking: the membranes of your cells always feflect the stuff you eat. Of course the body has its own fattyacid metabolism and can contribute here. but regarding the fats the general rule applies: you are what you eat. On the other hand: the milk you produce contains sti...	[ "The increasing trend to enrich foods with polyunsaturated acyl groups entails the potential risk of enriching the food with some OαβUAs at the same time, as has already been detected in some studies carried out in 2007. PUFA-fortified foods available on the market have been increasing since epidemiological and cli...
is it possible to have a mind like sherlock holmes?	That doesn't really happen in the BBC series so much. Deductive reasoning is a real thing. I'm sure you're not seriously asking if you can slow down time with your mind though.	[ "Sherlock Holmes and Dr. Watson find themselves in a university town when a tutor and lecturer of St Luke's College, Mr. Hilton Soames, brings him an interesting problem. Soames had been reviewing the galley proofs of an exam he was going to give when he left his office for an hour. When he returned, he found that ...
Did any groups still cling to the Roman deities after the fall of Rome?	The Roman Empire was of course not entirely Christian by the end of the fifth century, but it was pretty close. Pagans were never wiped out, but pretty much all our sources for this period and later were written by Christians, so we can't be entirely sure if they are accurate in their accounts of surviving pagans or no...	[ "After some 1200 years of independence and nearly 700 years as a great power, the rule of Rome in the West ended. Various reasons for Rome's fall have been proposed ever since, including loss of Republicanism, moral decay, military tyranny, class war, slavery, economic stagnation, environmental change, disease, the...
How did the ancient Romans think of what we today call race?	Some previous answers to this question while we wait for any further answers: from /u/cleopatra_philopater - _URL_3_ And another from cleopatra_philopater with further links to the origins of race perception -_URL_0_ From /u/medieval_pants - _URL_2_ And some consolidated links from the FAQ - _URL_1_	[ "The modern concept of race emerged as a product of the colonial enterprises of European powers from the 16th to 18th centuries which identified race in terms of skin color and physical differences. This way of classification would have been confusing for people in the ancient world since they did not categorize ea...
Can someone explain the dark trail in front of a plane in the sky?	It's the contrail creating a shadow in the low haze. _URL_0_	[ "A flash of light is seen, accompanied by severe turbulence, although the captain thinks it might be something else. There is no apparent damage to the aircraft. Still unable to contact anyone on the ground, and at the risk of potential collision with other aircraft, Farver finally decides to descend below the clou...
When an atom emits a photon, is it one blob of energy shot out like a bullet? Or is it a radiating wavefront coming from any one side of the atom? Or does the wave carry in a full sphere around the atom? Does the nucleus cause an eclipse?	The photon at atomic scales can be thought of like a blob of energy, representing an excitation in the [discrete nature of the electromagnetic field](_URL_0_). It's only at larger scales that light appears to behave like a classical wavefront.	[ "If a single photon approaches an atom which is receptive to it, the photon can be absorbed by the atom in a manner very similar to a radio wave being picked up by an aerial. At the moment of absorption the photon ceases to exist and the total energy contained within the atom increases. This increase in energy is u...
Why were siege engines not used more often in ancient times?	Siege engines were expensive in terms of expertise to design, materials to gather for construction and (for some types) ammunition, time to build, and men to operate. They were also difficult to move and ranges were limited. [This interview with Peter Vemming](_URL_1_) discusses his work recreating a 22-ton trebuchet t...	[ "Siege engines are fairly large constructions—from the size of a small house to a large building. From antiquity up to the development of gunpowder, they were made largely of wood, using rope or leather to help bind them, possibly with a few pieces of metal at key stress points. They could launch simple projectiles...

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