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fikfs
Since humans can change time-zones, can we adapt to longer days/nights?
[ { "answer": "Perhaps. The body's native circadian rhythms have a natural period (that is, what the circadian cycle would be like if you had constant darkness or light) that is very close to 24 hours, but is not exactly. This rhythm is modulated by light- which is how rhythms can adapt to a 24 hour rhythm and ch...
null
1kpsnr
how we use hubble's law to measure distances.
[ { "answer": "You see, the Universe is expanding. Not just at the edges, but everywhere. The space between any two points is expanding whether it is the space between galaxies or the space between your hands.\n\nWe know how fast space is expanding and we know how fast far away objects like galaxies SHOULD be m...
null
ami5q7
Does alcohol settle out of solution over time?
[ { "answer": "No. Alcohol and water are 100% miscible, meaning they blend together perfectly. For something to settle out of solution, you would need it to precipitate. ", "provenance": null }, { "answer": null, "provenance": [ { "wikipedia_id": "38220209", "title": "Liquid-...
null
9qpvck
how an empty pan left on a turned on stove burns?
[ { "answer": "Dont know about gas stoves but i do know that most pans/pots will melt before they catch fire (had a herion user as a roommate when we lived with my uncle as a kid) ", "provenance": null }, { "answer": "A stainless steel or cast iron pan will have a layer of oil coating the metal. Metal...
null
6jujjl
What makes something an acid and what makes something a base?
[ { "answer": "The concentration of H+ ions in an acqueous solution is what defines acids and bases. A strong acid such as HCl will dissociate and you'll have tons of H+ ions (and tons of Cl- ions) in the solution. A strong base will dissociate too and the calculation is the pH is slightly more complicated. For n...
null
14zmj1
What made the Normandy invasion so significant compared to the other battles in WWII? Why is this the one most often talked about?
[ { "answer": "I assume you mean what is the significance from an american/western perspective yes? In the larger ww2 scheme the invasion is certainly siginificant although probably not as significant as it's often regarded in the west.\n\nBut onward with the significance.\n\nNormandy is important because it fina...
null
vundk
how did the us go from a budget surplus under clinton to a massive deficit now?
[ { "answer": "THE most expensive thing (by far) in the world is war. ", "provenance": null }, { "answer": "Mostly war but also tax cuts for the wealthy. ", "provenance": null }, { "answer": "When GWB was president:\n\nWe had 2 Wars **NOT PAID FOR**\n\nLarge Tax Cuts **NOT PAID FOR**\n\nPr...
null
rx90i
Does a phone get lighter as the battery drains?
[ { "answer": "Yes - charging the phone adds weight (all other things being equal). A really, really small amount. Your fingerprint on the phone makes significantly more difference. You probably scrape off more metal/plastic plugging in the charger than the mass equivalent in charging the battery.\n\n[See...](_UR...
null
a81e0l
When did it become a common thing for employers to drug test their applicants? What events could be linked to the reason employers began doing it?
[ { "answer": "This is an interesting question without much historical background. This sub requires historical evidence prior to 1998 in its answers. There is not a lot from before 1998 on this topic. You may want to post somewhere else. \n\nWith that being said, the answer is three fold.\n1) The drug war.\n2) D...
null
7d3woq
How is it possible that the planet Mercury gets so cold and so hot on opposite sides? Shouldn't heat conduction make the entire planet roughly the same temperature?
[ { "answer": "There arent enough particles in the atmosphere to transfer the heat through. And with minimal atmosphere, there are also no wind currents to act like a big convection oven like we have here on earth. The heat simply doesnt spread, it radiates off slowly into space.", "provenance": null }, {...
null
3emp3e
why, when we look at younger people, do we perceive them as looking younger than us than we did at the same age. (aka me at 16 looked much older than whoever is 16 right now)
[ { "answer": "That's an opinion based thing. If I look at pictures of when I was 16, I look like a little kid. Then again 16 year olds also look like kids to me. Your perception of how people look changes with your age.", "provenance": null }, { "answer": "When you look at a face, your brain automati...
null
212yx7
why is our vision tinted blue after we face the sun with our eyes closed?
[ { "answer": "Detecting light requires chemical reactions inside the cells of your eye. The chemicals take a moment to reset/replenish before you can detect the light again. When you look at a bright light, it uses up these chemicals quickly, that's why you get momentarily blinded when looking at a bright ligh...
null
ks9qq
on my home theater system why are action sequences so thunderously loud but people talking barely audible. is it my setup or the film audio track itself?
[ { "answer": "Try bumping up the gain on your center channel. ", "provenance": null }, { "answer": "It has to do with dynamic range compression, or in your case, lack thereof. Movies are usually less compressed than tv shows, so there is a greater difference between loud and soft sounds. There is usu...
null
8fhror
How did the British view their Australian and New Zealander soldiers?
[ { "answer": "What time frame are you asking about? ", "provenance": null }, { "answer": null, "provenance": [ { "wikipedia_id": "5804962", "title": "History of Australia (1901–45)", "section": "Section::::Early 20th century.\n", "start_paragraph_id": 12, ...
null
qmt43
why do we have war, and why do we go to war?
[ { "answer": "Pick up a copy of Marvin Harris' book \"Our Kind\". It is an anthropological reader aimed at the masses, and your son should be able to make it through most of the topics. War is included from an anthropological perspective. \n\nFor my own opinion, not Marvin Harris': War is all about resources. Th...
null
1adoum
why do some (ebay) auctions have "reserve" prices?
[ { "answer": "Starting at 0 entices buyers to begin bidding and then once they've started they will keep bidding past a point when they may have begun bidding earlier.", "provenance": null }, { "answer": "I think it also gets the bidding ball rolling and taps into peoples competitive spirit. \nSomeon...
null
2gtjqf
How different are h.sapiens from today vs 1 mya?
[ { "answer": "Well, we only diverged from neanderthals around 500,000 years ago. So 1mya we would not be looking at h.sapiens exactly. That said I am interested in hearing more from someone who studies this and so knows more than me.", "provenance": null }, { "answer": "Language probably does not pre...
null
2zgjku
Why does it take longer to get dark at night in some areas over others that are along the same or are close in latitudes?
[ { "answer": "Twilight lasts a longer time the further you get from the equator, because the Sun moves at an increasing angle to the horizon. The extreme case is the polar regions ( > 66 degrees from the equator), where the Sun never sets at all during summer, while at the equator it sets essentially perpendicu...
null
638iq2
how did humans develop such that a well balanced human diet consist of a wide variety of foods when throughout most of human history we only had access to a few foods?
[ { "answer": "Eating sub optimally does not mean a swift certain death. It means a slightly lower quality of life (think of how you feel from a week of eating fast food vs a week of eating healthy), deteriorating more quickly (your brain may slow down faster as you age), a slightly higher risk of developing dise...
null
2zeuwu
Was Greek almost the official language of the United States?
[ { "answer": "tl;dr so essentially we had a vote to decide to print laws in German as well as English and it's possible utopians may have advocated making Greek Latin or French an official language (\" considered in the late 18th century to be the languages of God, rationality, and democracy, respectively.\") bu...
null
6ocn7w
how these modern tiny loudspeaker / amplifiers sound so good?
[ { "answer": "I know part of this, much stronger permanent magnets. Back then we didn't have neodymium magnets, utilising those in speakers allows for much more powerful motion of the speaker cone so you can get much louder and better sound from a smaller speaker with less power supplied to the coil. \nI'm 37 an...
null
5jdc2o
Is there a usage of quantum physics in our body?
[ { "answer": "Maybe. Known quantum effects in biology include long-range coherence during photosynthesis and [the magnetic field detection that birds use to navigate](_URL_0_). It's possible that [smell uses quantum effects](_URL_1_) to identify individual molecules, but from what I've read this is still a specu...
null
2uaybp
why don't they use metal detectors before an mri scan?
[ { "answer": "I think it may just be an unnecessary expenditure since you are assumed to know if you have metal in your body, or it would at least be present in any medical records or be in there for some plausible known reason. ", "provenance": null }, { "answer": "Section 2.4-3.4.4.2 of the [FGI Gu...
null
2g5vlc
Cold weather and lung disease - how are they linked?
[ { "answer": "This is pretty much asking for medical advice. You should go see a doctor.\n\nThere is a reflex that makes you cough a bit upon moving from warm air to cold air, but it's not severe and it does not last days.", "provenance": null }, { "answer": "There's really no link between being cold...
null
35zxkz
How did contemporary, mainstream western ideas about fashion and gender develop?
[ { "answer": "There was a [phenomenal answer](_URL_0_) posted a year ago in response to a similar question, and I'm not really sure it can be improved upon. James Laver is an old source for doing fashion history, but he's correct here.", "provenance": null }, { "answer": "At first I thought to break ...
null
3xiky5
why do people leave useless answers to amazon product questions?
[ { "answer": "Because Amazon asks people who have bought products to answer questions so some people just try to answer", "provenance": null }, { "answer": "You actually get an email from amazon, asking you if you can answer the questions (usually a product you recently bought).\nMy best guess would ...
null
5gxrm2
Does the supermassive black hole in the center of our galaxy have any effects on the way our planet, star, or solar system behave?
[ { "answer": "There aren't any noticeable tidal forces for most of the galaxy if that's what you mean. The ratio of the distance from the core compared with the size of celestial bodies is such that the gravitational effect of the core is essentially uniform for and given body (star, planet, etc.) That said, sta...
null
21goht
Why did German soldiers pay homage to Joan of Arc during WWII?
[ { "answer": "This is somewhat of a complex answer and she stretched far beyond German homage.\n\n1. It wasn't as much an homage to Joan of Arc the person, but more so what she began to symbolize in the late 19th century. Following the Franco-Prussian War, Joan of Arc began to represent a hopeful pride in a weak...
null
31lf9e
why is it that we typically make eggs, bacon, pancakes, etc. for breakfast & why does it seem so wrong in a sense if we eat anything other than those typical breakfast foods for breakfast?
[ { "answer": "Conditioning. If you were raised on pizza and soda for breakfast, milk and cocoa puffs would seem weird.", "provenance": null }, { "answer": "Because that's what we're accustomed to. Other cultures eat very different things for breakfast. \n\nFor much of American history, breakfast was ...
null
juvea
Why are sumo wrestlers able to maintain their athleticism while morbidly obese, but others of the same weight become bedridden and are at risk of sudden death?
[ { "answer": "sumos aren't morbidly obese. Turns out the bodyfat percentage on a lot of them is in the 15-30% range. Pair that wil the fact that they physically train, and you have, essentially, a power lifter body on a wrestler", "provenance": null }, { "answer": "sumos aren't morbidly obese. Turns ...
null
w2c5s
Meat and colon cancer
[ { "answer": "The best you can do is take a recommendation from a reputable source like the American Cancer Society. They have looked at all of the data as a whole and use that to make an informed recommendation. Most importantly, THEY HAVE NOTHING AT STAKE. They want to decrease cancer. You will find many s...
null
4zbwwx
I'm a penniless, but free, peasant living in Italy at the beginning of the Renaissance. What can I do to start making money and rise into the bourgeoise class?
[ { "answer": "In Florence you would find things... difficult, to say the least, but perhaps easier the younger and more talented in whatever craft you knew. At the time of the Renaissance, all meaningful means of production in Florence was tightly controlled by their respective guild, called *Arti*. The largest ...
null
49fmsy
why do some runners/drivers get a head start in pro races?
[ { "answer": "If you're talking about racing around an oval track, the competitor on the outside has to cover a longer distance than the competitor on the very inside, which is unfair if they all started at the same time.", "provenance": null }, { "answer": "Because the runner/driver on the outside t...
null
7mr9hz
Were there copies of the information in the library of Alexandria in other places around the world?
[ { "answer": "[This thread](_URL_0_) from /u/XenophonTheAthenian seems like it may answer your questions (or at least parts of them).", "provenance": null }, { "answer": null, "provenance": [ { "wikipedia_id": "333522", "title": "Bibliotheca Alexandrina", "section": ...
null
5rinkh
cellular respiration, why is it so important in maintaining animal health, growth and reproduction?
[ { "answer": "Cellular respiration isn't like, important in maintaining health. Its like saying a heartbeat is important in maintaining health.\n\nCellular respiration for animals..i guess, is how every cell gets energy to carry out(most) chemical reactions.\n\nThe Adenosine TriPhosphate molecule (ATP) that you ...
null
1m5kl5
in what context would you decide between saying "muslim" or "islamic"?
[ { "answer": "Muslim and Islamic are interchangeable when used as an adjective. For example \"Muslim architecture\" and \"Islamic architecture\" are both correct. However \"muslim\" is also a noun that refers to a follower of islam and is not interchangeable in that context. For example you would say \"John is a...
null
242gqm
In a zero gravity environment if I were to punch forward would I move with the punch?
[ { "answer": "No, as your hand moves forward your body will go backwards, but after both are done moving you will be stationary relative to your initial position.", "provenance": null }, { "answer": "Also, to clarify: If you punch *something other than the empty space in front of you* and hit it, you...
null
b4bv4f
Did the British Isles have their own variant of Vulgar Latin? What happened to it?
[ { "answer": "It's a difficult question, because evidence is scarce one way or another : the consensus is that Vulgar Latin might have been an urban language, especially in the south-eastern regions and place of active Roman institutions (such as York), which shared everyday use with British speeches, in a proba...
null
2ngrzw
Why is there vapor that comes off really cold things?
[ { "answer": "It's the result of atmospheric water vapour condensing into droplets.", "provenance": null }, { "answer": "I imagine you are talking about what you may see if you pull out a tub of ice cream from the freezer on a warm day you see little wisps coming off of the fridge and the object. Wel...
null
50cwzo
why do we fall asleep faster when the environment is being rocked/swung about (i.e. car, baby's bed, ship)?
[ { "answer": "Surprisingly, it looks like the science is still out on this.\n\nMy two cents would be that it is a hypnotic effect though. Continuous rocking is also a soothing / coping habit for people experiencing anxiety. I would presume it gives the brain a predictable pattern to work with - and that predicta...
null
4jko7x
what exactly does the little blue gel pad at the top and the rubber pad at the bottom of my razor do? is it just for style and we all assume it actually does something like add comfort or something but it actually does nothing?
[ { "answer": "They're lubricant. They both help the razor slide more smoothly across your skin but also leave moisture behind to prevent your skin from drying out.\n\nThe one at the bottom would help with function as you don't want hair to catch on the blades. The one on top would be more for comfort.\n\nIf y...
null
1pc8es
why does the us use a state system?
[ { "answer": "Because originally the USA were thirteen pseudo-independent colonies under the British crown. Contrary to common belief, the \"united\" states of America never got on with each other historically. Not all thirteen even rose up against the British to begin with, so when they eventually did unify the...
null
cc12ez
how bugs (not referring to tiny ones) somehow get through screened windows with no noticeable entrances.
[ { "answer": "Info: are you talking like stuck between the screen and a closed window? \n\nIf so, many screens, while sealed into the screen frame itself, are able to be open and closed. They can run on a little track in the side of the window frame and can actually leave a small gap at the top (between the scre...
null
1k4n0q
What are the origins of the Roman *Triarii*, and why did they assume the role of "the 3rd Line of defense?"
[ { "answer": "Ok I'm going to take a stab at this. \n\nThe Roman Army under the Etruscan kings was modeled after the Greek Phalanx with rounded shields (*hoplon*) and long spears. In 387 BC the Battle of Allia occurs and Rome is sacked. After the Gauls are driven back the phalanx is changed to the more recogniza...
null
3p2exn
How often were horse riding accidents when it was the primary form of transportation?
[ { "answer": "Did you have a specific time period or country in mind for your question? And are you interested in just horse-riding accidents or also accidents involving horse-drawn vehicles? I own an old history of the English courts in the 1860s that lists statistics for accidents involving both riders and pa...
null
2quj23
why does the dish for my satellite tv have to face south to receive signal?
[ { "answer": "Because, if you live in the northern hemisphere, that's where the satellite is.\n\nThey're in a geosynchronous orbit - which means they're above the equator and orbit the earth in 24-hours. So they stay in the same spot in the sky.", "provenance": null }, { "answer": null, "proven...
null
d7sjh9
why do some diseases tend to localize to specific areas while others remain more general? for example, hand, foot, and mouth disease, or genital herpes.
[ { "answer": "I suppose you're talking about communicable diseases. It all depends. But for viruses for instance, they can never infect a cell unless they bind to a receptor and get internalized. Not all cells express a receptor for a given virus, for example that's why you don't get the flu in your leg it binds...
null
ad0fgk
Potato Famine
[ { "answer": "Not to discourage further discussion, but you might be interested in this previous answer on the subject by u/mikedash:\n\n* [Was England's role in worsening the potato famine one of neglect or did they actually try to increase the suffering?](_URL_0_)", "provenance": null }, { "answer"...
null
3vo6lh
Why does the ball in this gif go in the direction it does?
[ { "answer": "Once falling, the air on the near side is actually being slowed down by the texture of the ball pushing back against the oncoming wind. This gets more pronounced as the ball falls faster. The far side air is being sped up by that side of the ball going in the same direction as the passing air. \n\n...
null
643k3q
Assuming identical atmospheric and other planetary conditions, is a hotter sun always brighter?
[ { "answer": "Luminosity is a product of the surface area and temperature, so if you have two stars with equal surface temperatures and different radii, the one with the larger radius will have a greater luminosity. Likewise, a star with a temperature 2,500 K cooler than the Sun could be hundreds of thousands o...
null
46nvpv
why do cars that are not driven rust while cars that are regularly driven do not?
[ { "answer": "the paint deteriorates, allowing water to get to the metal. also, as my cousin learned with his 79 camaro, when you leave it outside in the sun, it can eat away at the rubber stripping along the windows, allowing water to seep into the car and eat away things like the floor pan. also, depending on ...
null
4d9dt0
Why did the Japanese never adapt with anti-submarine tactics in response to U.S. submarine warfare in World War 2 that devastated Japanese merchant fleets?
[ { "answer": "Part of the reason was an obsession on the part of the Japanese Naval General Staff on the idea of a decisive battle - in 1890, an American strategist called Alfred Thayer Mahan published an extremely influential book called *The Influence of Sea Power Upon History*. This espoused the idea a single...
null
23pmok
Why are particles in a superposition state 'forced' into a certain state due to observation/measurement?
[ { "answer": "This is an often asked question - and for good reason. While physicists agree on the basic ideas of measurement, they do not agree on the deeper (arguably philosophical) nature of it. \n\n > I've always just wondered how measurement or observation can have an effect on a particle without directl...
null
4jeh8p
Is it theoretically possible to freeze photons?
[ { "answer": "The particles in a system do not \"freeze\" at absolute zero. A system at absolute zero should be defined to be in its quantum mechanical ground state. Because of the Heisenberg uncertainty principle, this does not correspond to \"no motion,\" since setting all particles to having zero motion will ...
null
b0zjzm
how do animals, like squirrels & foxes, know what is food and what isn't, in urban environments, especially processed foods.
[ { "answer": "First they learn from parents by what is being presented to eat and what they see being eaten.\n\nSecond they have some instincts to avoid or pursue certain smells or tastes.\n\nThey learn by trying, if they puke up something that still looks and smells like that thing they ate, then they avoid it ...
null
3vbevq
Does high pH water have a lower capacity as a solvent to dissolve more because of the electrolytes and minerals already in the water?
[ { "answer": "It depends on the ions that are already in the water. If the ions are also the same ions that are in the substance you are trying to dissolve, then the substance will dissolve less. If the ions can react with the ions in the substance you are trying to dissolve, then the substance will dissolve mor...
null
cj3rpj
how do some cars have a birds eye view of of the car when they’re parking?
[ { "answer": "The car has cameras in the front, rear, and in the two side mirrors. Those images are stitched together (kind of the same way that your phone creates a panorama) to give a kind of 360° view of the car's surroundings. That image is then displayed in such a way that it looks sort of like a bird's-e...
null
6tbv61
how did nicknames for names like richard and charles become dick and chuck and other ones like that when they are so different from their original form?
[ { "answer": "Some of my friends told me that Dick comes from Richard due to the original nickname of Richard being \"Rick\". After that, Dick came to be due to its rhyming with Rick.", "provenance": null }, { "answer": "What about Billy from William?", "provenance": null }, { "answer": "...
null
d89je3
why is it that light can travel for a billion years across the universe, but as soon as you flick off a light switch it disappears instantly?
[ { "answer": "Light travels very fast. A source is needed for the light. \n\nWhen you turn off the light, it's no longer emitting light. The light wave that was sent just before you take it off takes almost zero time to reach the point where the light is absorbed (whatever the light is shining on in the room).\n...
null
8lxvqt
How does lava stay hot until it hits the surface?
[ { "answer": "It's only the bits touching the air that seem to cool very rapidly at the surface. The more inner parts can take months to cool, as they become insulated by the solidified outer layers. Even in this case the convective cooling of the air is helping speed up the cooling of the lava.\n\nDeep below th...
null
3e1my0
Why would the high pressure of Jupiter's atmosphere destroy a probe?
[ { "answer": "We actually send a probe to sample Jupiter's atmosphere called Galileo, it fell into a region without many clouds though and Nasa didn't get much useful data back if (I recall). \nVirtually any probe would eventually get crushed and melt as it fell deep into Jupiter's atmosphere because it gets rea...
null
45n2fo
what happens next since justice scalia passed away?
[ { "answer": "Obama is going to appoint a new justice and that Justice will need to be confirmed by Congress. This is a pretty huge deal since the old court was pretty evenly split on issues because about half the court was liberal and half was conservative with John Roberts being the swing vote. Now the majorit...
null
2msj4y
what does obamas executive order on immigration do exactly?
[ { "answer": "From what I heard on Fox News, it shreds the constitution.", "provenance": null }, { "answer": "I can't answer fully, but it sounds like there are a few broad scenarios in which Obama says that we will not deport, and we will give a Social Security number. Allowing people to effectively...
null
ivspc
Is good posture an indicator of good health?
[ { "answer": "Another anecdote: I teach a few yoga classes a week, and I run. Yoga focuses closely on alignment in legs and feet, as well as the spine. When running at the park, I notice that almost all the good runners have their feet pointed straight forward and use good form. The people huffing and puffin...
null
vowsc
How would saturn-like rings affect life on an earth-like planet?
[ { "answer": "Saturn's rings are actually not very dense. They don't really have an impact on Saturn's surface, so you could probably easily assume the same if they were around an Earth-like planet. Here are my thoughts:\n\n > how would they appear in the sky?\n\nMost likely, they would be planar around the equ...
null
2i894q
What determines the frequency of a photon?
[ { "answer": "Conservation of energy in the process that created the photon?\n\nI don't think I understand the question.", "provenance": null }, { "answer": "A photon has to be created in a physical process within the system S. This process has to obey conservation of energy. Thus the difference in e...
null
7ds6s3
why do lighters have smaller flames when cold and bigger flames when warm?
[ { "answer": "Butane gets thicker when cold so it doesn't come out as fast so it only produced a small Flame. ", "provenance": null }, { "answer": "Butane boils at 30f degrees. The only reason it's a liquid is because the pressure forces it to be that way. When you hit the button, the open valve lets...
null
4hykti
how did charles manson influence his followers to do such drastic acts?
[ { "answer": "The same way that Hitler did. He had a very strong charismatic personality that was capable of getting people to trust him, believe and follow what he said. \n\n > I just can't imagine people being convinced so easily\n\nAnd that is where you are wrong. People are very easily convinced of things a...
null
1ogjpf
what is final fantasy? what is the plot, and why is it so damn famous?
[ { "answer": "Every one of them are almost completely disconnected from the others, so trying to think of them as a whole will make it really hard to get it. They all take place in different worlds, with different characters and different mythologies. \nThey do have a few common elements, but they're usually n...
null
4svnma
Asian exploration of America
[ { "answer": "Asian cultures did expand into North America. Migrations from Sibera and Alaska were particularly notable. The Thule started colonizing Dorset lands as late as the 1200s:\n\n_URL_1_\n\n\nThere are no written records of any of this, so it has to be pieced together through archaeological evidence. N...
null
548802
What happened to the French Foreign Legion during WWII? Was the legion divided, or did most of the legion go to either side? Were there ever any attempts by Petain's government to establish a foreign legion from Axis Powers?
[ { "answer": "I think this is a question that I can actually answer. I wrote my undergraduate thesis on the French Foreign Legion's demographics from 1914 to 2014. \n\nThe French Foreign Legion was very fractured during the Second World War. There was no central command that organized all of the different garris...
null
3vaujo
In Greek mythology does Hades ever actually do anything morally questionable?
[ { "answer": "The story that immediately pops into mind is the [Kidnapping of Persephone](_URL_0_). Hades takes Persephone, daughter of Zeus and Demeter (God of Agriculture), as his wife against the wills of Zeus and Demeter. Demeter falls into deep anger and brings famine across the world and will not relent un...
null
dnq99g
Why did agriculture develop independently all over the globe in the last 10000 years but not before?
[ { "answer": "Before that time period was [the last Ice Age](_URL_6_), which lasted for many thousands of years. The climate was so arid and difficult to survive in that it was not really possible for anyone to survive in one place long enough to discover & develop agriculture, since these groups of people wer...
null
3no6cg
why do cultures who rely heavily on rice in their diet typically use white rice which has less nutritional value than other types of rice?
[ { "answer": "One of the reasons why Asians have used mainly white rice over the years is that white rice lasts longer in storage than brown rice. The essential fatty acids found in brown rice usually begin to go bad after approximately 6 to 12 months of storage, the exact amount of time depending on how much ox...
null
d94a75
how a gamma ray burst could kill us all at any moment
[ { "answer": " Gamma ray bursts occur when very dense stars die and go supernova - basically, they explode. If such a star were to explode close enough to our Solar System, dangerous gamma rays would bathe the Earth, killing us off - think a dangerous nuclear leak, but on a cosmic scale.\n\n The odds of a gamm...
null
8jcuvt
Does losing sight in your right eye affect the functioning of the left side of the brain? and does this only impair your eyesight, or are there other implications ? [effectively you are reducing the input of visual information to the left side of the brain, thus reducing its functionality ]
[ { "answer": "It is a common misconception that the image from the left eye is processed in the right hemisphere of the brain, and vice versa. In fact, it is the left half of your *visual field* that is processed by the right hemisphere (i.e. everything to the left of the center of your gaze), and vice versa. So...
null
totmj
Is it possible for a planet to be larger than the star that provides light for it, so that the sun revolved around the planet?
[ { "answer": "Actually, regardless of the relative sizes of the sun and the planet, both would orbit around their combined center of mass. It's just that when one is much bigger than the other, the combined center of mass is very close to the center of mass of the larger body. For simplicity and convenience, it ...
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5tro1q
why do roads appear more curved as i drive on them compared to the way they appear on maps?
[ { "answer": "Scale. \n\nWhen driving if the road curves ten feet you will feel it. \n\nTo a map maker that small curve doesn't matter when they draw the road. \n\nSame thing with hiking trails. I've been on some flat trails that simply just did small ups and down. \n\nif the turn isn't large the map won't recor...
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1dki3a
what actually decides when i'm born if i'm a boy or a girl?
[ { "answer": "sperm have an X or Y chromosome. Eggs always have X. if you get a Y sperm you're going to be a male, if you get an X sperm you will be female... this only applies to humans (maybe some other mammals, I'm no expert)", "provenance": null }, { "answer": " > The sperm cell determines the se...
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ax4oys
what happened in world war 2, and why did it happen?
[ { "answer": "1. War happened. You'll learn more when you reach middle school and take your history lessons. \n\n\n2. Because we treated the Germans really badly after WW1 they elected a Adolf Hitler, a known power tripper, as their leader who eventually attacked Poland starting the European front, and because ...
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321seg
Have regulated languages evolved as much as English?
[ { "answer": "**short answer:** No, not usually.\n\n**long answer:** It's important to remember that even though there are these \"governing bodies\", perhaps most famously L'Académie française and Real Academia Española, they don't actually hold power over people's speech. There was some recent news about the S...
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2ra54c
what is a financial audit ?
[ { "answer": "Somewhere along the lines you filed some paperwork with the government saying how much money you made that year. The government blindly accepts that information as true and uses that to figure out how much taxes to charge you. An audit means they are going to double check to make sure that everythi...
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1rsg79
a grenade explosion
[ { "answer": " > Why can such a small thing do so much damage?\n\nExplosives are designed to be just that. You stuff explosives into a small, contained space and it makes it even more violent. The case is made of thick steel, so when the explosion ruptures it, it throws shrapnel all over the place and tends t...
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6r4wux
What is the environmental impact of air conditioning?
[ { "answer": "Air conditioning is a pretty big issue. \n\n\nFirst it is the reason big cities in southern Arizona can even exist(along with the massive increase in urban/suburban sprawl and it's resulting carbon footprint in those areas). \n\nSecond is the peak demand on electric grids is high afternoon when the...
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2is2we
Independent Cities - How did it come about that St. Louis and Baltimore are the only two US cities not a part of their respective county?
[ { "answer": "This does not directly answer your question about St. Louis, but Virginia also has cities being independent from the counties. It is he only state in the nation this way. This evolved from the colonial times and codified in the 1970's. Here is a link to good background summary:\n\n_URL_0_", "pr...
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2m0l9c
If Christianity came from the Middle East, why are there no Middle Eastern countries with a Christian majority?
[ { "answer": "Christians in the Middle East largely converted to Islam over the centuries. However, there are still substantial Christian minorities in some Middle-Eastern countries.\n\nLebanon has a large Christian population, currently making up 40% of the population. Christians were, in fact, the majority rel...
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2xtgp9
why aren't all humans dark skinned?
[ { "answer": "Vitamin D.\n\nThe further north you go, the less sun you get year-round. UV-rays from sunlight are used in the skin to metabolise Vitamin D, an essential vitamin. Less melanin in the skin (the stuff that makes your skin dark) means less UV blocked and more Vitamin D and better bone growth.", "p...
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o42ay
Is there a scientific reason why we assume the foetal position when we are in pain?
[ { "answer": "bodily instinct will be to protect itself and given that all our vital organs are in our torso shielding them with our un-vital arms and legs is just instinct so any horrible pain humans usually resort to instinct.\n\nBut its different for some people because everyones pain threshold is different s...
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1be2ux
if doma gets overthrown in the scotus will same sex marriage be legal everywhere in the us? or will each state have to pass it individually still?
[ { "answer": "DOMA does two main things:\n\n1. Makes it law so that if one state legalizes same sex marriages, all states do not have to recognize it.\n\n2. Denies federal marriage benefits to same sex couples, even in states where they are legally married. This is Section 3 of the law.\n\nThe part being talked ...
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b3xv81
why isn't government used software open source?
[ { "answer": "They probably bought a license and don’t own it. The government uses Microsoft office, but they buy volume licenses, Microsoft still owns all rights so it can’t be open source. ", "provenance": null }, { "answer": "Because there is no legal requirement to limit itself to that kind of ap...
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2nne4z
Is there a chance of siblings not sharing any genetic material?
[ { "answer": "While it is formally possible, the probability of sharing NO genetic material is vanishingly small (ie, essentially zero). A fairly simple straightforward explanation that might help give a sense to the numbers can be found here: _URL_0_", "provenance": null }, { "answer": "The chance i...
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1405jj
What capabilities would the now abandoned Super Colliding Superconducter have had compared to the LHC? Are there any questions it could have answered that the LHC cannot?
[ { "answer": "I would suggest you to read [this](_URL_0_) for starters.\n\nAlso, a minor difference but it got me confused for a second, it's called Superconducting Super Collider, or SSC.", "provenance": null }, { "answer": "The SSC was expected to run up to 20 TeV (TeV is a measurement of energy, T...
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14fwbw
Today marks the anniversary of the last time the United States declared war - WWII. What is the difference between a declaration of war and a military engagement?
[ { "answer": "When congress passes legislation that uses the term \"Declaration of War\" in the title, it's often referred as the formal Declaration of War. U.S. congress has not **formally** declared war since WWII. The only difference between formal declaration and authorization of war by Congress is using the...
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4dczev
Are there any issues in which the historical record and archaeological evidence strongly disagree with each other?
[ { "answer": "The legend of the Dorian Invasion would be a good example of this. The Ancient Greek literary tradition held that Spartan rule over the region of Lakedaimon was established during this Invasion (also called the Return of the Herakleidai), in which the Dorians (to whom the Spartans belonged) descend...
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svyct
If heat is the jiggling of particles which can't exceed the speed of light, does this mean there's an "Absolute Hot" similar to absolute zero?
[ { "answer": "\"There is no agreed-upon value, among physicists, for a maximum possible temperature. Under our current best-guess of a complete theory of physics, the maximum possible temperature is the Planck temperature, or 1.41679 x 10^32 Kelvins\" - [Source](_URL_0_).\n\nThat's 141,679,000,000,000,000,000,00...
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158l02
Why is that an ARM based processor and an x86 based processor cannot be compared clock for clock.
[ { "answer": "You can't compare even different core architectures using the same instruction set clock for clock. \n\nGenerally ARM instruction set is more RISC-like than x86. On average, each instruction does little less than x86 instruction. Binary sizes for ARM are little bigger than for x86 (10-15% bigger). ...
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uke9g
My buddy's dad found this rock on their farm. Apparently a meteorite may have hit the region, could this rock have been affected by that collision?
[ { "answer": "I haven't found a lot of peer-reviewed journal articles about the impact, but what I've found seems to indicate it happened 83 million years ago. At that time, that part of Alabama/Georgia was under a shallow sea. I'm rather skeptical that a rock that large would be found in overlying sediments, es...
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337avz
Are Cloudless Tornadoes possible?
[ { "answer": "A tornado is only visible because of the debris it throws around. The air can tornado without picking anything up. If the tornado formed in an area with little to no loose ground cover, like a flat rock desert, it might be hard to see.", "provenance": null }, { "answer": "I'm assuming y...
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a0j4zn
how does a country first react if they are being invaded by another country?
[ { "answer": "Normally there is some form of advanced warning, in some cases a declaration of war in others intelligence gathering indicating a build up of forces on the border area. The general first action is a mobilisation of the army, so all on leave etc. army forces report to designated areas to arm and dep...
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27xvzc
Is friction affected by surface area? For instance if I bought bigger tires for my car would I stop faster? what is the equation for this?
[ { "answer": "Contact area does **not** affect frictional force. \n\nYou might be surprised (I was!), but think about a 1kg 2x1x1cm block on a ramp. Put the brick down sideways, and the surface area is 2cm^2. That 1kg is being distributed over that whole 2cm^2 with a force of 500 grams per cm^2.\n\nNow stick tha...
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