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how come americans have large portion sizes and relatively cheap prices for their food?

When you go to a restaurant, you pay for the service first, then for the actual food. As a rule of thumb, the ingredients usually make up only 1/4 to 1/3 of the costs. Additionally, the work of preparing a dish twice as large usually isn't twice as much for the chef. So it comes down to the customer's expectations. Americans expect large meals, so the restaurants deliver - without hurting their profits much.

Doesn't the speed of light disprove Fermi's paradox?

When discussing the Fermi paradox, people usually only talk about civilizations in the Milky Way galaxy. The distance between galaxies is far to great to consider an inter-galactic civilization (though it may be possible). The diameter of the stellar disk of the Milky Way is only about 100,000 light-years. So if a civilization existed on the other side of the Milky Way and had the technology to peer on to the Earth, they would see a planet teeming with life! 100,000 years ago, the Earth was already inhabited by humans!

is taking a shot of 100 proof alcohol the same as taking 1.25 shots of 80 proof?

Essentially yes. Except for the additional water in the 80 proof alcohol. But there is just as much alcohol in both shots so it will have the same effect on your blood alcohol content.

why do humans start getting body odor after they go through puberty?

Basically (the way I was taught this at least) you have two major types of sweat glands, apocrine and eccrine. Sweat produced by eccrine glands is mostly water. Apocrine sweat is more oily and contains a whole bunch of other stuff (which I won't get into). So bacteria can metabolize the components of apocrine sweat far more readily. Apocrine glands (which are heavily concentrated in your pits and groin) are stimulated by sex hormones, the levels of which rise sharply during puberty. So you get an assload of oily sweat, which is then colonized by bacteria, who generate foul odors.

Do bone conduction earphones protect hearing?

There's no reason to believe that they would. Hearing loss is usually caused by damage to the inner ear, which is still getting as much sound exposure with bone conduction as it would through the normal path of sound.

why do circles tesselate hexagonally?

It's all geometry. Assuming equal radii between all circles, if you place them in a way that they don't intersect but touch each other at exactly one point (tessellating) and you start with just 3 circles, those circles form a triangle shape. If you connect the centerpoints of those circles, it forms an equilateral triangle (equal length sides, each corner is 60°). So if you continue placing circles the same way around that center circle, you can do that a total of 6 times because 360°/60°=6. A hexagon has 6 sides. Hope this helps.

Where do vegetables and fruit/nut bearing plants get their vitamins and minerals?

They get all the minerals they need from the soil. Vitamins for plants aren't the same necessarily as our vitamins, because a vitamin is something the organism needs to survive but cannot produce on its own (vitamin D is not a true vitamin to us). So, for example, plants can produce vitamin C (ascorbic acid) through a glucose metabolism pathway. We do not have this pathway and need to consume it. Additionally, plants can make alpha-linolenic acid (ALA) which is the first omega-3 fatty acid. We cannot make ALA because we lack desaturase enzymes beyond 9, whereas 12 and 15 are required to form ALA from stearic acid. But essentially plants, being autotrophs, only get some things from soil and air; the rest they can synthesize.

What's the noise a formula 1 makes when it changes gears?

It's most likely a backfire. When the car is accelerating its at full throttle/load, and the engine runs out of power, so it's time to change gears. imagine going from full throttle to no throttle (changing gears) then back to full throttle. The bang u hear is unburnt fuel exploding in the exhaust after its left the combustion chamber, which is after engine has gone off full throttle to change gears. It's excess fuel that was needed to sustain full power, but is no longer needed when off throttle.

what determines how internet lag in different games looks?

Male programmer type guy here. It just depends on how the programmers who made the game decided to handle the case where the game isn't getting updates from the server. Some games leave the character in place, and then warp him when the updates resume. Others avoid the warp by having the character fly from their old position to the new one. I seem to remember that neverwinter nights had a thing where it would try to estimate where the character would be based on their last position and trajectory, which led to weird glitches. I could be making that up though.

In the United States, have there been any particularly strong Vice Presidents, and how was The Senate different under them?

In addition to Calhoun, John Adams regularly presided over the Senate and partook in debates, and beats Calhoun by one vote for the most tie breaks. That said, while they are the nominal head of the Senate, the Constitution also says that the House and Senate get to write their own procedural rules in Article I, Section V, Clause II: > Each House may determine the Rules of its Proceedings, punish its Members for disorderly Behavior, and, with the Concurrence of two thirds, expel a member. In practical terms, the Vice President doesn't have much power if the Senate decides to write the rules to say that they can't do anything other than break ties and be physically present, the only things the constitution explicitly grants them authority to do so. Something like Frank Underwood barging into the Senate and immediately taking over wouldn't really happen since at present, party leaders run the floor and they have junior senators sit in the presiding chair.

Do black holes really vary in size or does the collapsed point in space just vary in intensity?

Every amount of mass has some radius that, were it all to be compressed within the radius, it would form a black hole. This is called the Schwartzchild radius, and it's calculated by the formula r=2GM/c^2 . G is the gravitational constant, and c is the speed of light. These are both constant, so the math works out the same for them every time and the quantity of mass is the only variable that can alter the radius. Interestingly, smaller black holes will spaghettify you much faster than larger black holes will. This is because of the tidal force. Anything that enters a black hole is stretched apart by its gravity. The gravitational force weakens with distance; the parts of you closer to the black hole (say, your feet, if you're falling straight in) end up attracted by its gravity more forcefully than the parts away from you (like your head, in this analogy). This effect magnifies as you are stretched more and more until... well, spaghettification is the scientific term for this for a reason. With larger black holes, the difference in position of your head and your feet, relative to the size of the black hole, is smaller than it is with smaller black holes. Your feet will still be pulled more forcefully than your head, but the difference won't be as drastic. With a large enough black hole, you might be able to survive a decent part of your trip to the singularity. So, the size of a black hole is dependent solely on its mass, but a more massive black hole will take longer to destroy you. Either way, you aren't getting out.

why do strange graphical effects sometimes occur when alt+tabbing a computer game?

It's because the game takes up the majority of your computer's resources and stays at the forefront. Your computer needs to load in all the other stuff that the OS and other programs need before you can use them.

How much of time dilation is due to the gravity well versus relative velocity?

You can indeed separate the two effects if the field is weak. I've done the explicit computation for the orbit of Mercury around the sun [here](_URL_0_). It turns out that in a circular orbit the time dilation due to the orbital speed is exactly half the gravitational time dilation. P.S.: GPS satellites are *not* in geosynchronous orbit.

how exactly is the “stop/start” automatic engine feature in newer cars “better”?

Barely any wear and tear, better for the environment as all that time you spend not moving while the engine running is time that CO2 and pollutants are spewing out when they don't need to be. Multiply all that time by millions and millions of cars and you have a significant CO2 saving. Saves fuel and thus cash too.

how do all the bodies, tanks etc. get cleaned off the battlefields?

Usually they don't. Outside of Kursk you can take a spade out West of the city and dig down just a few inches to human remains, shell casings, etc. Vehicles were only removed if they were salvageable or were in the way. After the war civilians gleaned the site for years for scrap but anything else was just abandoned. Modern armies recover bodies for burial, but when the battlefields are too massive sometimes they dont. Remains are still found in Flanders when someone digs a well and new phone line is laid. In Germany the Allies employed POW's for years in work gangs cleaning up battlefields. Once a tank burns it is useless. The heat from the fire ruins the temper of the armor, so they were just abandoned. Military trucks were used as work horses all over Europe for years so people stripped all the wrecks of parts pretty quickly. The hulks got towed to scrap yards.

why does our body need uv to create vitamin d when uv exposure increases our risk of skin cancer?

UV light is an energy source, since humans are automatically exposed in varying degrees to this energy source we have evolved to make use of the "free" energy to create vitamin D. We have also evolved to darken the skin to prevent over exposure to UV which would increase risks of skin cancer. Only animals like naked mole rats don't have to concern themselves about exposure to some degree or other to UV light _URL_0_

Is there any particular reason why so many people in the United States claim Cherokee ancestry?

Hello. I'm a mod over on /r/IndianCountry, the second largest and most active Native American subreddit. We recently constructed an FAQ [with a section that answers this specific question](_URL_1_) and links to several sources to back it up. I would like to note, though, that this is more of a social question with a historical context. In short, according to Gregory D. Smithers, associate professor of history at Virginia Commonwealth University and author of *The Cherokee Diaspora,* the Cherokee adopted a tradition of intermarriage after contact with the Europeans for several reasons, such as increasing diplomatic ties. Because this was actually encouraged by the Cherokee, it isn't *impossible* that those from the geographic location of traditional Cherokee territory have a Cherokee ancestor. However, another thing to note is that most people don't actually know and just say they have Cherokee in them because it is the family legend. The same professor mentioned above, Gregory D. Smithers, also states (bold is mine): > [**"But after their removal, the tribe came to be viewed more romantically,** especially in the antebellum South, where their determination to maintain their rights of self-government against the federal government took on new meaning. Throughout the South in the 1840s and 1850s, **large numbers of whites began claiming they were descended from a Cherokee great-grandmother.** That great-grandmother was often a “princess,” a not-inconsequential detail in a region obsessed with social status and suspicious of outsiders. By claiming a royal Cherokee ancestor, white Southerners were legitimating the antiquity of their native-born status as sons or daughters of the South, as well as establishing their determination to defend their rights against an aggressive federal government, as they imagined the Cherokees had done. These may have been self-serving historical delusions, but they have proven to be enduring."](_URL_0_) So the reality of things is that people like to claim something even if they don't have exact proof. One reason is the exotic factor of having native blood. That FAQ I linked touches on several other reasons. Point being, while there is some validity to the possibility of one possessing Cherokee blood or an ancestor, most cases are usually false.

how does the new iphone voice command system (siri) work?

I don't know the exact details, but I do know that any query made to the system goes to remote servers with the voice command. There, the technology across multiple servers parses your voice to determine exactly what you say (some say the original creators of the voice recognition technology, Nuance, [is still primarily responsible](_URL_1_)). After that, a completely separate process then parses the words you said to pull out key words and phrases to interpret what exactly you meant and how to resolve your request. Once that process knows what you want, then it's just a matter of calling the right sub-applications with the right arguments. Like setting a reminder at a certain time, calling a certain person, or looking up some query on [Wolfram Alpha](_URL_0_). The accuracy of the transcription capabilities and Siri's interpretation power is what's cost Apple several million dollars in research and purchases to get Siri where it is now.

How livable would 2x the Earth's gravity be?

You might want to check out some discussion we've had here recently on the same topic. [Here](_URL_1_) and [here](_URL_0_).

why are chemical weapons worse than regular ones? is gassing a town worse than bombing it, assuming the number of innocent deaths is the same?

Chemical weapons are worse because: 1) They kill slowly. 2) They are not as controllable as they drift in the air and on the water. This means they cause a lot of collateral damage. 3) They often contaminate and kill those attempting to treat the injured, and they often have very few to no actual treatments that work. 4) They contaminate the environment for a long time killing people years after the attack. There are still some battlefields from WWI that are toxic and make people sick or even kill them when they spend time in them.

why is it so much louder when you whistle with two fingers?

I can't do that. I just wanted you to know I both envy and respect your ability to whistle with your fingers

Would it be possible to use time dilation to travel into the future?

In terms of physics, yes. The technology for that doesn't exist right now though. We can send things at like 20 km/s, and we'd need to go like ten thousand times that fast to start seeing these effects.

Are there multiple types of Electromagnetic Fields?

> I've seen it described as a "field produced by charged objects", but in other places it sounds more like one continuous thing that extends through all space The electromagnetic field extends through *all space.* It simply has essentially a zero value away from charges. (though self propagating disruptions can travel without charges—called light) It doesn't have to be zero, the Higgs field for instance has a non-zero expectation value throughout all space. When we say a charge or magnet generates and EM field, this is short hand for saying they give a nonzero value to regions in a shared universal EM field. It's just very small and close to zero in most places in the universe.

How does salt damage concrete on a molecular level?

Normally the embedded steel in concrete (be it re-bar or welded wire fabric) is protected from corrosion by an effect called passivization caused by the high PH (around 13) of concrete. When water containing dissolved chlorides makes it way to the steel, through the concrete pore structure or more typically cracks, the chlorides negate that passivization and allow the steel to corrode. When steel corrodes it expands in volume which causes internal tensile stresses in the concrete. Since concrete is very poor in tension it tends to fail which leads to de-lamination of concrete layers and eventually visible spalls (pot holes). So its really not so much the salt damaging the concrete, but the salt causing corrosion of the embedded steel which causes the damage. Other things, like carbonation, can eliminate the passivization of the rebar, but those mechanisms tend to take much longer. My instinct is that "drive-way safe" is a buzzword. There are non chloride based de-icing solutions out there, but they are much more expensive and generally not quite as effective. I am an engineer that is focused on the restoration of concrete parking structures, so this is an area of expertise.

how/why does one company make so many different, unrelated products?

It's called "vertical integration" and it's regarded as a smart move because the more a company diversifies its products, the less hurt they are if one product takes a hit (for instance, if they need to recall, or if a competitor comes up with something better, or if a change in the marketplace at large makes the product less desirable -- like if you were selling bread when the Atkins craze hit, it would be nice to also have a sub-brand selling bacon). [30 Rock had a pretty great moment] (_URL_0_) explaining why some people find this phenomenon a bit worrisome.

What are the hazards of Fusion technology?

People discussing fusion reactors usually focus on the use of abundant Deuterium extracted from water as the fuel. While Deuterium would be part of the fuel mix, most of the fusion reactor designs are built around the use of a combined deuterium-tritium fuel source. The ITER reactor for example [will use a 1:1 mix of D-T fuel](_URL_0_). The D-T fusion reaction produces an excess neutron. These neutrons have applications such as producing more tritium for the reactor's fuel, but they will also induce radioactivity in the materials that make up the structure and lining of the reaction chamber. The end result will be the production of nuclear waste - radioactive metals and the like. It will be no where near the volume of radioactive waste produced by fission reactors; but it will be produced none the less. Some designs have also called for the fusion reactor to be used to breed plutonium from the neutrons and U238 lining the reaction chamber. The plutonium would be used to fuel fission based reactors but has the added issue of being a nuclear weapons material - something that could be considered a hazard of the fusion reactor.

why are space rockets so hard to handle?

You need to look up what they call "the rocket equation". Lets say you want to throw 10kg into orbit. Orbit speed means you have to accelerate it to something like 9.4 km/s (thats per _second_). Thats pretty fast. To accerlate your 10kg AND your rocket to that speed you need a certain amount of thrust. That means bigger engines, or engines that burn longer both of which requires more fuel. But that fuel has mass that you ALSO have to accelerate so now you have to bring MORE fuel to accelerate the other fuel, but wait the mass you have to accelerate drops as you burn fuel so now you need less fuel to accelerate it..... and now you have a 2nd or 3rd order differential equation. Now throw in multiple stages (why multiple stages I won't get into), the reserve you need to maybe land your rocket like SpaceX, and you have some hard math. If your payload changes weight at all, you have to recalculate the whole shebang. As for the control - the aerodynamic forces acting on a rocket that is accelerating to that kind of speed - and before it leaves the atmosphere - are tremendous; and even relatively minute shifts in center of gravity of your rocket (as the fuel gets burned up) or a shift in payload (remember that resupply rocket in The Martian that blew up?) means you have to have control surfaces or nozzle gymbols to constantly adjust the thrust so its through the center of mass or things start tumbling and the forces rip it apart.

What methods were used to estimate the population of pre-columbian America? How reliable were they?

There were a number of methods used that resulted in widely varying estimates. Charles Mann provides a brief but thorough discussion of methods used to estimate pre-contact populations in the new world in "1491: New Revelations of the Americas before Columbus" (Vintage, 2011). Some researchers used early records archived in church and governmental facilities then attempted to correct for population crashes caused by the plagues. Others based their estimates on number of households and estimated household size. Sherburne Cook was among the more prolific students of prehistoric populations publishing papers from the 1950s to the 1970s. In the mid 1970s there was an American Antiquity memoir published that employed assumed initial population estimates from skeletal populations (usually from excavated cemeteries) then applied estimated fertility and mortality estimates and extrapolated from there. Kroeber, in the "Handbook of the Indians of California" (1970, California Book Co) employed house and house pit numbers from early ethnographic surveys. Baumhoff (1958) in California Athabaskan Groups (University of California Anthropological Reports, Berkeley) developed population estimates for Northern California tribes based on the availability of fish resources. All have their merits and their shortcomings. Mann notes that Henige in "Numbers from Nowhere: The American Indian Contact Population Debate" (1998: Univ.. of Oklahoma Press) is the pinnacle of vilification of indigenous population estimates and estimators. This is a tiny sample of the reams of population studies that have been conducted. They all seem to have the same basic problems: the veracity of the basis for original estimates (censuses, house counts, fish populations and skeletal counts) and the estimated impacts of the plagues. The issue is further complicated by the bias of researchers and readers. Some tend to maximize the estimates others are much more conservative.

how do dual sim phones work

A [dual SIM](_URL_1_) phone can hold / use 2 [SIM cards](_URL_0_). The SIM card holds an identifying (hardware) number that identifies the phone, so you can set up a subscription and associate the SIM number with a phone number. So dual SIM phones can answer/handle two separate phone numbers. These can be on the same provider (Verizon for example) or on different providers (one Verizon one AT & T). Popular with business persons; they can have a single phone device, but a personal number and an official business number on it.

What was happening pre World War 1?

Here's some answers I've given previously on the subject [The Balkan Wars] (_URL_1_) [Lead up to and outbreak of WWI] (_URL_2_) [Balkan Nationalism and the Outbreak of WWI] (_URL_0_) The 1890s saw the formation of the Triple Alliance (Germany, Austro-Hungary, Italy), the formation of the Franco-Russian and Franco-British Ententes, and the Anglo-German Naval Arms Race began. The early 1900s saw the First and Second Moroccan Crises, the Bosnia Crisis, the First and Second Balkan Wars and the Scutari Crisis. It saw the beginning of a Land Arms Race in 1912, starting with Russia, then Germany and France. There was growing tension. Germany's pointlessly aggressive stance in Morocco, combined with the naval arms race, alienated the British, and drew them closer to France, while events in the Balkans lead to increasing Austro-Russian antagonism. However, considering the lengthy affairs these crises were, and the important issues at stake, few civilian and even political observers believed that an assassination in Sarajevo could possibly lead to war. The pace of events in the July Crisis was much greater than in previous crises, and so decision makers found themselves under greater pressure.

What percentage of new immigrants learned "fluent" English in the 19th century?

To which country?

why does the uk require citizens to register to vote? why not automatically enroll people when they receive their national insurance number?

You need to be registered at an address so they know which constituency you are in so your vote can be cast in the right place. If they didn't voting would be chaotic and it would be difficult to detect fraud.

how does facebook "share bait" work. what are the spammers getting out of getting it?

Money. The more people you can attract to your facebook page/website the more money you can get out of ads. Plus if you have some bad intentions you can try to infect the user when he visits your website, which is mostly equal to money.

How was the first Operating System made when there were no computers to make it on?

Our modern notion of computer didn't arise suddenly well-formed from theoretical concepts. In fact, the entire idea of operating system isn't necessary for a computer to work at all (and most microcontrollers don't run one). To start with, what exactly is an operating system? Well, it's hard to pinpoint one or two defining characteristics, but most operating systems exist to perform two distinct functions: abstracting the details of the underlying hardware resources so application programmers (the people who write stuff like office suites) don't have to worry about them; and managing those resources. So you can see a computer could just be programmed directly over the hardware without an operating system; you can program wherever you want, as long as you have a way of transferring your instructions to some storage medium the computer understands. Actually, most early computers had no storage at all, and had to be programmed directly by plugging up thousands cables and switches in huge control panels! The situation improved a little with the introduction of punched cards (early 1950s) to replace these panels, but everything remained more or less the same until the introduction and commercial viability of the transistor (later 1950s). With the advent of reliable and mass-produced computers started a phenomenon of role separation, where the programmers were no longer operators who were no longer maintainers. To share these very expensive computers between users, people came up with ways to time-share their punched cards, which led to the creation of batch systems. These involved one machine to read the cards and write them onto magnetic tape, people to take the tape to the main computer, and another machine to print the results from the output tape onto human-readable paper. Modern operating systems appeared with the increasing automation of this tedious and error-prone process, with more and more features becoming incorporated into the actual computer and programmers having to know less and less about the actual hardware they were using. IBM's OS/360 was the first operating system where you pretty much only had to know you were running an IBM 360 to work, and the trend continues into our days. So you see there we didn't create an operating system in one fell swoop to run on the Analytical Engine or valve-based computers, but instead they evolved as a natural consequence of our eternal desire to do less and less work to get more and more results out of our tools. Some of our current terminology regarding operating systems still betrays their historical origins, in fact.

since cellphones are here to stay and commercial flight is here to stay, why haven't they figured out how to make it so we can keep our phones on.

You *can* have them on. You can't use them as a phone. _URL_0_ One, cell towers aren't designed for phones 30,000 feet in the air that can hit multiple towers. Two, on a long flight having people babbling on phones would cause some passengers to politely invite others to step outside.

What were the implications of Operation Unthinkable and just how close did it come to fruition?

I do not know much about the inner workings of the British military and government in April and May of 1945, and so I cannot say how seriously the British themselves took this plan, but I can say that Winston Churchill's goal of stunting Soviet influence in postwar Europe did not align with the aims of Harry Truman's government at the time. And since the plan obviously relied heavily on American power, we can say that the plan never came close to fruition. Note that "Operation Unthinkable" was not the only measure that Churchill thought about taking in order to counter the rise of the Soviet sphere in April of 1945. Churchill had contacted Truman directly with the hope of convincing the American president to renege on the agreement between FDR and Stalin regarding a "Soviet sphere" by ordering the American army to continue its march through Prague. In brief, the American army had entered western Czechoslovakia in early May and plans put forth by Eisenhower had initially called for the liberation "beyond the Karlsbad-Pilsen-Budweis Line [i.e., western Czechoslovakia] as far asa the upper Elbe [i.e., at least the west half of Prague]." When the Soviets protested that this violated the agreement made at Yalta, however, Eisenhower instead ordered the army to halt. Churchill, however, argued that "there can be little doubt that the liberation of Prague and as much as possible of the territory of western Czechoslovakia by your forces might make the whole difference in the post-war situation [in the region]." Truman, however, showed no interest in pursing a blatant anti-Soviet policy at this time and instead allowed the Red Army to liberate Prague (Stalin remained unsure if Truman would honor the agreement reach with FDR at Yalta, however, and quickly diverted forces aimed at Berlin to instead liberate Prague). So in early May, when the British finished outlining their "Operation Unthinkable," Truman demonstrated clearly that he would not go so far as to challenge the Soviet Union by liberating Prague. The idea that he might then wage war on the Soviet Union in order to quell Soviet influence in Poland--influence that FDR and Stalin had already agreed at Yalta was a necessary component of Soviet postwar foreign policy--was an absurd assumption by whomever had put together Operation Unthinkable. There was no chance, at all, that it would be implemented as it was originally envisioned. **Sources**: Ambassador to France Jefferson Caffery to Secretary of State Edward Stettinius, May 6, 1945, *FRUS,* 1945, IV: 447-448. Winston Churchill to Harry Truman, April 30, 1945, *FRUS,* 1945, IV: 446. The language of this telegram is nearly identical to language used earlier by Eden. John Erickson, *Stalin's War with Germany: The Road to Berlin*, (New Haven, Conn: Yale University Press, 1999), 625, 783-786. Operation Unthinkable, excerpt: _URL_0_

nuclear fusion.

Well, we *don't*, is the short answer. But let's not stop there. Small atoms work in a strange way. Normally if you think about two separate objects that you want to put together — think Legos or whatever here — you find that you have to *do work* in order to put them together. You have to pick up the Legos, line them up just right, then *squeeze* in order to get them to stick. Small atoms are different. Small atoms, like hydrogen atoms, actually *want* to stick together. In other words, they *release* energy when they snap together, and it *takes energy* to pull them apart. *Big* atoms, like plutonium atoms, are just the opposite. They're so big and heavy and wobbly that it takes more energy to hold them together than it does to break them into pieces. That's how nuclear *fission* works. You take something that's just barely holding together, then you give it a little nudge and it comes apart into pieces, and you use the energy of those pieces flying apart to boil water to turn a steam turbine … or blow up a city, whatever. Same thing, different scales. But small atoms actually release energy when they stick together to form bigger atoms. So you can, in principle, take two hydrogen atoms and stick them together and find that energy is released in the process — like putting two special Legos together and finding they get *hot* when they click into place. But there's a challenge. Even though small atoms want to stick together, they naturally push each other part, like the north poles of two bar magnets. If you bring the two atoms *close* to each other, but not too close, they'll move apart, because they repel each other. So in order to get them *close enough* to stick together — and thus release energy — you have to work against that natural repulsion. Think of it like rolling a ball up the slope of a volcano. Up at the top of the volcano is a hole, a nice, deep one, and you want the ball to go into the hole — and the ball *wants* to go into the hole. If the ball rolled toward the hole, it would drop right in. But before you can get the ball to go into the hole, you have to get it up the slope. If you just nudged the ball up the slope, it would roll a little ways, but then stop and roll back down again. So in order to get the ball into the hole, you have to give it a real kick, really push it hard, so it climbs all the way up the slope and falls in. The way we give atoms a real kick is to make them *hot.* Hot atoms are really moving fast, they're rocketing all over the place. So if you take a lot of hydrogen atoms — in a gas — and heat them up, you'll eventually get to the point where if two of the atoms happen to hit, they'll stick, and release energy. The trick with that is, though, that hot gases create *pressure.* If you heat up a gas, it'll exert pressure on the walls of whatever container you're holding it in until the pressure ruptures the container and the gas comes rushing out (which, by the way, cools the gas back down to equilibrium temperature again). So in order to get energy out of nuclear fusion, you have to first start with hydrogen gas, then you have to build a *really really strong* container to hold it, then you have to heat the gas up *a lot* to the point where fusion starts to happen. When that happens, you start to see pairs of hydrogen atoms hitting each other and sticking — which again, releases energy, thus heating up the gas *even more* … which ruptures your container and makes a pretty big explosion. That's called a hydrogen bomb. But in principle, if you built a *really really really super-incredibly strong* container, then did all those things, the container *wouldn't* rupture when the hydrogen atoms start to stick. In principle, if you could build a container like that — and also figure out how to let heat escape from the container in a controlled way, but while still keeping the hydrogen hot enough that it continues to fuse — you'd have a really good, really long-lasting source of heat that you could use to boil water and turn a steam turbine, thus doing mechanical work or generating electricity or both. But nobody's figured out how to do that yet, which is why I said we *don't* directly harness the power of nuclear fusion. It's never been done … and in fact, it's not entirely clear that it's even possible at all. However, we do *indirectly* "harness the power" of nuclear fusion. We do it constantly, in fact. Because the sun is a big ball of mostly hydrogen undergoing nuclear fusion. In the case of the sun, you don't need a container to hold the hydrogen gas in; it holds *itself* in, by the pressure of its own gravity. The weight of all that hydrogen pushes down on itself, squeezing the hydrogen in the very center to the point where it can fuse. The energy released by that fusion percolates outward through the dense layers of hydrogen gas, heating the gas up and making it glow, and that's what sunlight is. Sunlight goes out in all directions, and a tiny part of it hits the Earth, and that light is used by plants to break the chemical bonds holding carbon dioxide molecules together, and the oxygen is thrown away and the carbon is used to make trees and stuff, and either right away — in the form of logs — or many years later — once the trees and stuff have been squeezed into petroleum — we combine those plants with oxygen again and release the heat they stored from the sunlight, thus boiling water and turning a steam turbine to do mechanical work or generate electricity. Sometimes we can cut out the middle-man. Light from the sun can hit special metallic plates called photovoltaic cells and create a little trickle of electricity directly. That's useful when we only need a tiny bit of electricity. Or light from the sun can warm the air in some places while leaving it cool in others, making the warm and cool air circulate — wind, in other words — and we can stick a turbine at the top of a tall pole and suck mechanical energy out of the wind and use it to do mechanical work or generate electricity. Or sunlight can hit water and heat it up, causing it to evaporate into the air and then later fall out as rain, some of which lands at high altitudes and then, due to gravity, runs downhill toward the sea, and we can stick a turbine in the flow and suck mechanical energy out of that and use it to do mechanical work or generate electricity. Or we can simply eat food, which uses sunlight to grow, and thus power our muscles so we can do work ourselves, with our own bodies. But mostly, with precious few exceptions, all the energy we encounter comes pretty close to directly from the sun, which shines because of nuclear fusion. So there's more to the nuclear fusion story than so-far-unsuccessful experiments aimed at creating it in a laboratory and using it directly.

What was the Islamic attitude towards and tolerance level of other religions, prior to the sacking of Constantinople by the crusaders and the destruction of Baghdad by the Mongols?

Why the West attained a period of dominance is a separate question that I won't address here, although I will point out: Latin Christians conquered Constantinople from *Greek Christians* in 1204. That doesn't seem to be a breaking point in Muslim attitudes towards the "Franks" and "Romans" for, well, obvious reasons. And as we'll see, it's dangerous to draw conclusions about what the situation and attitudes today might be from a range of attitudes in the past, because even interpretations of a sacred text depend heavily on the historical context of the interpreter. ~~ It is impossible to speak of "*the* Muslim attitude" towards other religions and their practitioners in the early Middle Ages, just like it's impossible to identity a universal view in the modern world. Instead, we can look at a range of laws and literary portrayals from specific historical contexts, and see how particular events affected them. The Quran's specific views on non-Muslims are fairly well known. Jews and Christians share an Abrahamic foundation and are *dhimmis* or People of the Book. They can be permitted to exercise their faith freely in Islamic territories while subject to restrictions such as an increased tax. Practitioners of other religions (the web of Middle Eastern paganisms, Zoroastrianism, etc) are not afforded that leeway. A famous medieval, though not authentic to the named ruler, example of restrictions on *dhimmis* is the [Pact of Umar](_URL_0_). While we can't know whether restrictions like this were ever officially deployed, it shows us what the relationship between Muslims and protected non-Muslims was *idealized to be* by at least one group of Muslim legal scholars. In practice, the application of the Quranic principles here varied. Sometimes Zoroastrians were extended *dhimmi* protection, and sometimes Jews and Christians weren't. The Almoravid and Almohad dynasties in North Africa and Iberia, for example, attempted to force Jews in particular to convert to Islam. Their Umayyad predecessors in the west, on the other hand, actually *discouraged* conversion among the lower aristocracy, for the tax benefit. The question of what *jihad* meant in early Islam is as vexed as it is today. There's no question that the infant religion's adherents achieved explosive success by military conquest across the Near East and North Africa--the Umayyads are in Cordoba (Spain) less than a century after Muhammad. The early years of Islam are characterized by an apocalyptic, messianic sense in which jihad is indeed a spiritual *offensive*. As I noted earlier, that doesn't necessarily mean forced conversion--secular motives like money were attractive. (Richard Bullitt has postulated that conversion occurred over time on a logarithmic scale, with the bulk of conversion ramping up in the 9th and 10th centuries). It did mean Muslim *rule* and establishment of Islamic faith in new territories. But--the expansion of Islam slowed. Christianity stubborned kept hold of northern Iberia; in the 9th century even Byzantium started making incursions into the Muslim Near East. That second example offers a prime chance to witness how historical events affect Muslims understanding and representation of non-Muslims. Our earliest Arabic sources portray Byzantium as a *rival*: some levels of hostility, but very respected. They are especially impressed with the political and economic importance of Constantinople, and of the splendor of the city's architecture. Once the Byzantines pick up some military action, Muslim writers ramp up their vitriol. They find new ways to label the Byzantines barbaric, amping up the rhetoric of horrid Byzantine morals. Even in the Latin Crusades, when the Islamic world is under *direct invasionary attack* by 'barbarians,' individual Muslim governors sometimes allied with the Franks against each other. (Although the chronicles are pretty uniform in calling the Franks atrociously bad fighters...it's just, they have really good armor and weapons, shucks.) In the Fifth Crusade, which dead-ended for the West in a *massively* humiliating capture of the entire crusader army in Egypt, the Muslim force treated them rather well and allowed their release as long as they returned to Europe. Unlike the later medieval Church, medieval Islam has no centralized body of law or dominant interpretation. It's characterized by a series of overlapping legal and theological schools of interpretation that jockey for ascendancy throughout the era. As the rate of expansion of Islam grinds down almost to a halt, scholars debate the meaning of *jihad* in a world that suddenly doesn't hold apocalyptic hope and expectation of triumph. One line of interpretation emerges that divides the world into two: dar al-Islam and dar al-harb, the world of Islam/submission and the world of war. This spiritualizes the idea of jihad: it is defensive, a matter of protecting Islam and its people, rather than working to prepare the world for the messiah through conquest. Unfortunately, Mottahedeh and al-Sayyid, who've done a lot of the work on early notions of jihad, don't really talk about whether we can trace this spiritualization of jihad in specific contexts to changing treatment of non-Muslims under Muslim rule (i.e. did a focus on defensive jihad ever lead to increased conversions or increased signs of repression). Medieval Muslims who did find themselves in dar al-harb, on the whole, don't seem to have taken this idea of defensive jihad into their military hands. There are some cases of localized rebellion in Christian Spain and Sicily, but isn't that what you'd expect of any conquered people feeling ill-treated? Glick and Meyerson have both discussed the ways in which Muslim revolts in Christian Spain don't have hallmarks of proto-nationalism, they're in fact rather similar to or overlapping with Christian peasant protests of unjust conditions as well. The Muslims of high medieval Sicily, conquered by the (Latin) Normans, found themselves deported en masse to the Italian mainland at Lucera. And yet they still *chose* to fight for their homes with the local Christian army against the papal invaders. The Muslim community of the Christian-conquered Ebro Valley in Spain stubbornly insisted, through letters sent abroad and sermons preached at home, that Iberia was their home and they *would* remain there against all the calls of the zealous Almohads in North Africa to leave *dar al-harb* for the comfort of the Islamic world. (And it sure wasn't because of amazing generosity on the part of their Christian overlords, to be sure.) And then you have to consider, of course, that most Muslims are just ordinary people trying to live their lives. Islam spreads in medieval West Africa *almost* by accident. Merchants from the Sudan and North Africa set up trade colonies of sorts in the Ghana Empire, common language (Arabic) facilitates trade, being Muslim allows you to tap into a global trade network...By the time Ibn Battuta makes it to Mali in the 14th century, he's treated to a full recitation of the Quran (in Arabic) while amusedly observing cultural differences in the practices of individual Muslims between Mali and elsewhere in the Islamic world. Overall, then--if we can even talk about an "overall"--it's a complex picture that depends heavily on specific historical contexts. The status of Islamic expansion, the school of law or theology, military developments on both sides, messianic expectation, the passage of time, geographic, economy, the goals of individuals: so many factors in the matrix, so many experiences we can identify in concrete times and places.

why do people shiver when they are using all of their strength?

They aren't actually shivering. Their muscles are rapidly changing the fibers they use to balance and lift the load. One set of fibers is doing the majority of the lifting while the other set relax slightly then they switch positions creating the illusion of shivering. This switching can happen upwards of several thousand times per minute.

why does our brain get attached to people, things, places etc, and why do we have a strong need to find the one we love

Probably all to do with our survival instincts. We can get attached to places as a way to demonstrate that it's "our area", and to produce offspring we adore the person that is deemed by our brain as the best mate, for healthier and stronger children. This is my biased idea, so take it for what it is.

what does remastering a game entail?

It *completely* depends on the company doing the "remastering". There is no fixed set of things except, perhaps, as requirements from the licensor. In addition, there are often limitations on what can be overhauled because original development materials may have been lost or are otherwise no longer available. A good example of this is Beamdog/Overhaul Games' remake of the Baldur's gate series: Because the level/area files for BG are rendered 3D scenes, and because the original 3D model files had been lost, Beamdog had to work with the level images as they were originally released- with some fancy math used to upscale the resolution of those images while still seemingly retaining detail. On some other games most or all of the original development materials remain, including original artwork, and higher resolution versions of the masters, including audio, used. But how much work and what work is done is very much handled on a game-by-game basis.

[Meta] This sub desperately needs a "Answered" flair for posts that have ad least one mod approved reply

This one gets asked a lot, because it's a seemingly intuitive solution to the common problem of clutter - threads with high comment counts that suggest the presence of an answer, but in reality are all just removed comments. However, the issues - both practical and conceptual - raised by actually implementing an answered flair are considerable, and our collective judgement has long been that the downsides by far outweigh the advantages. For a more full explanation you can check out [this post](_URL_2_). But the basic issues as I see them are: 1. Except for the most basic of factual questions (which we tend to redirect to our Short Answers to Simple Questions thread anyway), history rarely admits 'one' answer to a given question. Differing perspectives, methods, sources and so on all mitigate against definitive answers to most questions. An Answered flair - whether watered down by different terminology or not - risks giving a different impression, as well as discouraging users from adding new perspectives once that it has been declared 'Answered' (this is feedback that we have received from our flair community). 2. These suggestions are usually based on misconceptions of how we actually moderate the sub. We don't read every comment that gets made, relying instead on user-generated reports to spot problematic answers that we then might evaluate in more detail if it seems necessary. Changing this to reading and evaluating every substantive comment would represent an exponential increase in workload for what is - compared to the size of the sub - a fairly small team of active moderators (and that's not even getting into the fact that for this to work, each flair would need to be manually altered and updated - we can't train a bot to be able to tell the difference between 700 words of wisdom and a 700-word scrawl of conspiratorial madness). Keep in mind as well that the mods aren't omniscient - unless one of us happens to have expertise in a particular topic, checking the content of any substantive answer is a lot of work (and often involves collaboration and discussion on our end - an answer which we initially let stand might be taken down later once someone with enough knowledge to spot the flaws is awake). Asking us to put what amounts to seals of approval on all such content would stretch us well past breaking point, and would if anything result in a massive increase in removals of longer answers, on the basis that we don't want to be seen to endorse material that we aren't completely sure of. While the line between 'decent enough to let stand' and 'good enough to endorse' might seem very thin, from our perspective it's a much bigger deal. 3. It likely still wouldn't solve the main problem, while simultaneously interfering with the various ways we currently use flairs. For the large numbers of users on mobile, flairs often won't be visible to users before accessing the thread anyway (thereby obviating the sole advantage of such a flair, which is saving users a click). For users less familiar with the sub, who provide most of the added clutter in highly visible threads, a flair system is unlikely to get noticed, judging purely by how few of these commenters appear to read the Automod message in every thread. If you are a regular user who finds the wasted clicks on deceptively empty threads to be annoying, we would heartily recommend our custom-designed [browser extension](_URL_1_) made by [/u/Almost\_useless](_URL_0_), which does a great job of making thread comment counts actually accurate.

I heard something off of my granddad about World War 2 spies. He said that, when the British were interrogating German spies, they would end the interrogation with "good luck" or "hail victory" in German and, if the German replied, they would know he was a spy. Is there any validity to this?

As far as "good luck" goes, he may be thinking of a scene in the 1963 film *The Great Escape* where this happens in reverse- escaped British PoWs are captured when a Gestapo officer wishes them "Good luck" in English and one of them instinctively replies "thank you". I have seen claims (for instance in *This Great Escape: The Case of Michel Paryla* by Andrew Steinmetz, and *The RAF's French Foreign Legion* by G.H. Bennett) that this incident is based on the real-life case of the French escapee Sous-Lt. Bernard Steinhauer, who was fluent in English and German as well as his native French and who was captured at Saarbrücken station after replying in English to an English greeting by a Gestapo officer- although sources differ on the exact phrase used. (Like most of those who escaped in the breakout from Stalag Luft III, Sous-Lt. Steinhauer was shot a few days later)

how can general pain medication like paracetamol and ibuprofen treat so many different things?

Prostaglandins are natural chemicals that are released into your body when you are injured or sick. When they're released, they make nearby nerves hurt. This is when your body can tell that something is wrong, and you feel pain. Meds like ibuprofen target prostaglandins. It keeps more of them from being made, which reduces more nerve pain. So it's not so much that pills can hit a wide variety of targets, it's that the body's target is the same for most injuries.

why do massive arcade style coin operated machines suck so much in comparison to other video game consoles?

It actually used to be the opposite way around. Back in '94, we were getting things like Cruisin' USA and Sega Rally that were a generation ahead of where consoles were at the time, and that were built on hardware that wasn't bettered until the PS2 generation. Unfortunately, that's pretty much what killed arcades. Used to be that consoles advertised themselves as offering an arcade-grade experience. When the PS2 surpassed them, it rendered them redundant, basically killing their market, and killing their progress. And that's why today, arcade has gone from being an aspirational term to almost a dirty word.

why do developing countries receive development aid from other countries instead of simply "adding" the same amount of money into government budget?

Hyperinflation from printing money to cover government deficits happens because the supply of the currency is dramatically increased. Note that this happens relative to the currency of which the supply is increasing--for example, when there is hyperinflation occurring with the Zimbabwe dollar, prices when paying with U.S. dollars may actually be comparatively stable. This is why, when inflation becomes very bad, people try to abandon the local currency and use a more stable foreign currency, even if it is illegal to do so. Development aid comes in the form of foreign currency or it's aid "in kind," in the form of goods. So the supply of the local currency isn't changed at all. It can still have a strong effect on the local economy, but for different reasons.

Can someone explain the physics going on with the snapping shrimp when it shoots its shockwave bubble attack?

The most basic scenario of cavitation is if you have an infinite fluid, and magically cause a sphere of it to disappear, and track what happens to the water trying to fill that vacuum. In this case, it's not a vacuum but a vapour bubble, but the water collapses just the same. When this happens, the water nearest the bubble moves in, then the water that was next to that moves towards the bubble, etc, creating a shockwave travelling through the water. I don't know the physiology of the stun effect, but it's probably similar to hydrostatic shock that injures gunshot and grenade victims: a pressure wave travelling through the body. The reason the bubble leads to such a powerful shock is that the water collapses really, really fast, like a good portion of the speed of sound in water. The same type of bubbles are a major cause of damage to ship propellers (but from the propellers themselves, not from shrimp), and that's what originally got people thinking about this. The temperature is highest when the pressure is highest, which occurs when the bubble is smallest. You can see this through the ideal gas law assuming a polytropic process, but I don't think that explains the temperatures observed. I've heard other things, like the pressure causes gas inside the bubble to ionize, and the ions emit bremstrahlung radiation as they accelerate. Hope that helped.

what starts the pumping of the human heart and how does it keep going?

You don't sound dumb. It's a good question. The heart has its own electrical system that keeps it pumping independent of brain function. Sometimes it misfires, though, and that can lead to things like heart attacks. Basically, as long as there's blood flowing through the heart to keep it alive it doesn't even need to be in the body. That's what they do for heart transplants.

why do i see lots of black guys with white girls, and very few white guys with black girls?

The same reason black men date white women, because black women are crazy.

why is 95 gasoline powerful than 92?

Are you talking about octane rating? If so, it's not more powerful. Octane rating indicates how much compression the fuel can sustain before it ignites. A high octane rating can be compressed more, thus high-powered engines that compress the fuel more need it in order to avoid it igniting prematurely, causing knocking and engine wear. If your car doesn't have one of those engines, any octane gasoline will work just the same for you.

how do scientists know how much of an impact the human body can take in a car wreck?

There has been much research done on corpses to analyze how strong bones and other tissues are and there are a great many analyses of injuries where we can estimate the forces involved using physics and then compare the forces with the degree of injury.

How does gravity affect atom nucleus?

Several things regarding this. As a reminder of the strengths of forces acting on the particles: Strength of gravity of a proton acting on an electron: F_g = G *m1*m2/r^2 = 3.67*10^-47 Newtons Strength of electromagnetism acting on an electron: F_e = k * q1 * q2 / r^2 = 8*10^-8 Newtons In particle physics, the effect of gravity of the particles on each other is effectively ignored. The effect of gravity is also considered from center of mass. Which in this case, protons/neutrons are composite particles of charged quarks, you have to consider the effects of masses acting in various directions when you get too close, similar to digging to the center of the Earth leaves you weightless because of even pulling all around you. Electrons/quarks also are effectively point particles, as they don't seem to have a physical size. The "size" of a particle is kinda vague, but they are usually defined as an interaction radius to various forces, so they are different sized depending on what you are comparing them to. More importantly however, you are in the realm of quantum mechanics, so classical approximations don't hold effectively. The reason the electron does not fall into the nucleus despite the forces involved is that the wavefunction of the electron does not allow it to. Gravity also requires a quantum theory in order to properly integrate in for reasonable predictions (we do not have a quantum theory of gravity yet). Theoretically though, if something were to have zero distance, or at least very very very close, they are predicted to turn into a black hole because the mass density of that tiny volume reaches that level. Of course, we have no observed instance of this because of how highly improbable it is, but in theory, that's what will happen.

if formula 1 teams use totally smooth tires for perfect grip in dry weather, why are there laws in place about grip on road tires?

F1 (and NASCAR, etc) have different sets of tires for dry and wet conditions; they go into the pits to change tires when the wet happens. The "rain" tires have grooves. Your parent's tires have to handle all weather conditions (unless they are rich with a Ferrari and a racing garage) so your government has laws in place for road safety that require tires to have a minimum amount of grooves in them.

Why is it that Neutrinos can pass through so much material without a problem (like the Earth?) How are we able to detect them if they so easily penetrate matter?

Neutrinos only interact through the [weak interaction](_URL_2_) because they don’t posses an electric charge (needed for electromagnetic interaction) or a color charge (needed for [strong interaction](_URL_1_)). The weak interaction being a short range interaction, neutrinos interact very little with matter, meaning they can go through it almost perfectly. To detect them we basically use [gigantic pools](_URL_0_) of [heavy water](_URL_3_), hoping a few neutrinos (I don’t know what the rate is exactly) will interact and we can detect them. *Note: gravitation can be neglected because neutrinos are so light.* PS: maybe to clarify the “why is it that neutrinos can pass through so much material” part: because matter is mostly void and it’s the electromagnetic force of the atoms that prevent matter from going through other matter (like 2 magnets will repel each other even if they’re not touching); and as said above, neutrinos don’t interact with the electromagnetic force (a block of wood isn’t stopped by a magnet).

what causes the “refrigerated taste” food can get when it is uncovered in the freezer too long?

All the food inside is drying out and all the moisture takes smells into the air with it. The fridge is closed and small, so all that smelly air is trapped in there. Over time, food left in there a long time will have a dry crust and the humid smelly air will start to go back into the dry crust. The yucky taste and texture is all those mixed smells and dried out crust combined.

is it real that when you left the refrigirator door open it consumes more energy?

It does cost more electric because your letting the cold out so it has to use more power to try and keep it cool BUT it is never going to be noticeable on the electricity bill unless you leave it fully open all day in temps with 20c and even then it's going to add maybe 25p per day, BUT here's my question who on earth goes to the fridge and leaves the door open regardless of whether it costs more electric it will make your food go off sooner and not be cold, I have never met anyone that opens the fridge and leaves it open it litterally makes no sense

What happens when you prepare acids with heavy water?

What you are referring to is called the [isotope effect](_URL_0_). It is real, but it isn't usually very pronounced.

What is the spectrum of professional opinion on the Kennedy assassination?

Oswald shot him. In the head. That's pretty much the only opinion that will not get you rejected for tenure. Why? Because like all conspiracies, the JFK conspiracy relies upon such a perfect chain of events, placement of people, and reliance on their complicity, as well as not leaving a paper trail a mile long, that it borders on the absurd. What is really more plausible? That one crazy communist with a gun slipped through the security cracks and got off three honestly easy shots on a day that the President went against the better advice of his security team? OR, that the Cuban rebels/CIA/FBI/Mafia/Alien Greys/Freemasons/Rosicrucians/Girl Scouts conspired to off the most powerful man in the free world with out anyone having a guilty conscience, verifiable evidence, failures in security, lapses in timing, or just plain bad luck (if you have any experience with real government secret planning, you would know how many things get completely cocked up)?

what's more inflated, the price of diamonds or artificial diamonds?

That's a damn interesting question but impossible to answer because we do not know just how horribly inflated diamond prices are.

How much Spanish troops were on Cuba and Puerto Rico during the Spanish American war?

Spain's force in Cuba numbered 278,457 soldiers, distributed in 101 Infantry Battalions, 11 Cavalry Regiments, 2 Artillery Regiments, and 4 Marine Battalions. The force in Cuba made up the bulk of Spain's entire military force, being nearly 57 percent of the Army. This force was bolstered by another 82,000 volunteers. Another 10,005 were in Puerto Rico, and 51,331 in the Philippines, for another 12 percent of the Spanish Army. Although a large force, the Spanish Army of the time was somewhat decrepit, manned with poor quality conscripts (those who could afford to pay the tax to avoid universal conscription always did), and never with enough equipment, even though they did carry decent Mauser rifles. Although commanding a large part of the Spanish budget, the bloated officer corps (1:4 officer:enlisted ratio!) ate up much of that with their salaries. The aloof officer corps wasn't up to the task of leadership, and the men were not all that easy to lead in any case. At sea, Cuba and Puerto Rico were defended by 8 cruisers, 6 destroyers, and 49 other small craft manned by 2,800 sailors and 600 marines. As with the Army though, the Navy was a paper tiger at best, as barely any of the Spanish fleet was up to modern standards and able to go toe-to-toe with the US Navy, which as it turned out, made mincemeat of 'em. "Spain, Army" and "Spain, Navy" from Encyclopedia of the Spanish-American and Philippine American Wars, ed. by Spencer C. Tucker

if the deepest depth drilled by man is about 8 miles, and the crust is nearly 20 miles deep, how were scientists able to discover that there is an upper and lower mantel and inner and outer core?

The same way you are able to tell what's in the box your grandmother sent you at Christmas. When you shake it, a sweater sounds different from a PS4 controller. Obviously scientists can't shake the earth, but the earth shakes itself sometimes, and scientists in different places are always listening (or rather their seismographs are listening). By comparing what different locations record, they can make good guesses about what's inside, just like you may be able to do. Edit: Thanks for the gold!

When did the word "ass" start applying to people's butts instead of just to donkeys?

Don't forget that outside of the US it's spelt and pronounced 'arse,' whilst the type of donkey is still universally called an ass. A lot of Irish accents have a very 'ass'-like pronunciation of 'arse,' and of course Irish immigrants made up a huge number of Americans during the initial population boom.

why is having two heads such a commonly seen mutation?

Most often these are not mutations but conjoined twins. One case is when an egg doesn’t split properly during development; another theory, though heavily disputed, is the fusion of two separate fertilized eggs during development.

crime shows always say “they hung up before we could trace the call”. what goes into tracing a call and how long does it actually take?

It's 100% Hollywood bullshit. It might have been true decades ago when phone calls were connected manually, but not since the electronic switches that we have since the 1970s.

A friend of a friend came into possession of this. Any idea what it is

While these sorts of posts are welcome in this subreddit, it's often not the best place to put them. You may find you have better luck in /r/whatisthisthing, as the sub specializes in identifying unknown objects.

why do student loans get shifted to different banks/loan services?

Everyone is making money but you. You take out a loan from Bank A for $100,000. If they kept it, you'd probably end up paying them $150,000 back. They sell it to Bank B for $120,000. Bank A makes $20,000 right away, and Bank B makes $30,000 in the long run because now you're paying THEM the interest for the loan.

If you were smaller than the length of a light wave, what would you see?

We *are* smaller than the wavelength of a lot of electromagnetic waves (e.g. radio waves) and our eyes simply don't detect them, that is, we see nothing. We can pick them up with other specialized instruments, for example by connecting a length of wire to a properly tuned receiver circuit, which is what an antenna and radio are doing. What we call 'light' is no different from these longer wavelength EM waves, just happens to be in the range of wavelengths to which our eyes are sensitive. Note that most radio receivers are smaller than the wavelength of the radio waves themselves, which can be many meters up to kilometers in length. So it is certainly possible for a detector to be smaller than the wavelength of radiation to which it is sensitive. Even in our eyes this is true, because the fundamental detector protein itself, [rhodopsin](_URL_0_), is smaller than the 400-700 nm wavelengths we can see. It's just the structure of the eye needed for gathering more light and forming an image that makes it big.

why do we sense five basic tastes (sweet/sour/bitter/salty/umami or savoury)?

Sweet - Your basic energy unit is glucose, this taste makes you want to eat things high in sugar Salty - Sodium is a vital electrolyte is maintaining physiological balance (water, chemical, energy production, ect) so you need foods with it too. Umami - Tripped by the amino acid glutimate, and not present in all people. Belived to help attract you to protein based meals too, making for a balanced diet. Bitter - Trips when you eat things with alkaloids and nicotines. These chemicals are present in a wide variety of poisonous plants. Good detection of these can help you stay alive. Sour - Trips in acidic foods. Can both be a warning from poisonous food and needed food like lemons for vitamins

the sexual revolution

Why more sex? Birth control was more widely available. The Vietnam war in the 60's/70's brought back boys that were now men who had horrible PTSD and drug exposures. Ways of escaping could have been sex, "Make love, not war". They felt their lives were at their end, their number is called, might be up. Why divorce rates? Abusive spouses could be left as women in the workplace was more mainstream. Birth control did not trap women in a marriage with 10 kids... Church laws eased and remarrying after a divorce was possible, in church, about that time. A few points. Not comprehensive by any stretch!

why can't you eat salmon after it spawns?

I think you can eat it, it's just that salmon that have spawned have not eaten for months and are essentially on their last breath. Their meat becomes mush when cooked traditionally. It is not very appetizing. It also loses much of its oil.

Sources for the Ainu and Emishi in Pre-Modern Japan

It's not the right era (up til 1600), but I checked my copy of [*Sources of Japanese Tradition vol. 1*](_URL_1_) and it has some primary sources that mention the Ainu. 1. "New History of the Tang Dynasty" mentions the ainu arriving at the Chinese court w/ a Japanese envoy in 663 (p.12) 2. "Reform Edicts" from the Taika Reforms in 645 mentions keeping weapons handy in provinces bordering the Emishi (p.78) 3. p. 266 has some information from campaigns against them. 4. The index has a listing for Buddhism and the Ainu on p.212, but for the life of me I don't see them mentioned on that page. It's either an error, or I've gone blind. My copy of [*Sources of Japanese Tradition vol. 2*](_URL_0_)(1600-2000) is in a box somewhere, so I can't check it for you, but that might be another place to look for translated primary sources from the era.

How exactly does tea block the absorption of iron in your blood cells?

Tannins are an organic compound found in both green and black varieties of tea. The tannins found in tea can interact with iron in the gastrointestinal tract, rendering iron less available for absorption. Drinking tea with a meal that contains iron-rich foods can decrease iron absorption by up to 88 percent, depending on the amount of tannins consumed. *A tannin is a compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids. Source: _URL_0_ Also, from the wikipedia page on tannins: Foods rich in tannins can be used in the treatment of HFE hereditary hemochromatosis, a hereditary disease characterized by excessive absorption of dietary iron, resulting in a pathological increase in total body iron stores.

Was the Speed of Sound ever considered a theoretical speed limit?

The 'sound barrier' was never considered a theoretical speed limit while the term was being used. The tips of airplane propellers had been brushing up against it for a long time. Bullets has been breaking it for a long time. The V2 bomb broke it during every flight. The term referred to the many disparate problems that pop up when you pilot an aircraft designed for subsonic speeds (M < < 1) at transonic speeds (M~1). Drag increases, your controls could become ineffective or even reversed, shock waves could create aerodynamic loads that cause your plane to break up. It was a 'barrier' to pilots because trying to go past it often killed you. Understanding and solving all these issues and packaging the solutions together into a plane that could be piloted all the way from M=0 to M > 1 was a daunting challenge, but one that was met in 1947. It was kind of like how nuclear fusion is today. The science all says it's possible, but engineering around the practical problems involved is proving extremely difficult.

cloning

Traditional reproduction has a sperm and egg. Both have half of a full set of chromosomes. When the sperm enters the egg it deposits its half of the chromosomes, now with the two combined the newly formed zygote has a full set. It begins to develop as a new individual with neither the exact DNA of its mother or father, but a mixture. In cloning you remove the chromosomes of the egg and insert a complete set. It can be from the mother, father or any other member of the species The resulting individual will be an exact duplicate of whatever was the source of its chromosomes. This is a clone.

What could be the consequences of extreme harvesting of tidal energy?

_URL_1_ _URL_0_ tl;dr: Currently, water hitting already extant natural barriers in the world causes a slowing of the rotation rate that lengthens the day by about 2.3 milliseconds per day per century. That's because of friction of the ocean against natural barriers and the ocean floor... maybe some other stuff, its a complex topic -- this energy is roughly .1 TW per year. The current tidal power generation planned projects equal about 115GW, roughly the same amount lost to 'natural causes'. This number is very low compared to the world's entire energy consumption-- that is because sites that have a high differential between high and low tides occur only in limited, specific configurations of underwater terrain around the globe, so 115GW is about all we can do and expect to make our money back at this point in time. If we were to do all the currently planned easy/practical projects, we would double the rate of slow, a day would be about 4.3 milliseconds longer per century. Now let's get ridiculous and build a wall all the way around the earth. every day, the average height of the tide pours from one hemisphere to the other. Ignoring a lot of real things we'd have to worry about like efficiency of power generation and other losses, we might generate about 2TW. So 2TW + natural barriers (although they may cause less friction if we've built a wall around the whole world), we're now slowing the earth down by about 45 milliseconds per century. Not something to be concerned about.

How much sailing did Native Americans do on the Great Lakes?

Lots of paddling but no Sailing There is significant physical evidence that Native Americans traveled to various islands in the Great Lakes. There are hunting artifacts on Pelee Island and pictographs on Kelley's Island in Lake Erie. There were Ojibway (Chippewa) recorded as living on Michipicoten Island at the time of first contact by Etienne Brule around 1620, and there were prehistoric copper mines on Isle Royale. Both of these islands are in Superior and are near to the route of the Edmund Fitzgerald. They are both around a dozen miles off the the mainland, which is close enough to be visible, but far enough to make it more than just a lazy afternoon paddle. (And not in a storm, and not in November.) Later, when the fur trade picked up, the larger loads of furs were transported to Montreal in 30-40 foot canoes, except for the obvious portage at the Niagra River and the rapids near Sault Ste Marie. Although every paddler learns to adjust course for tailwinds, the first actual sailing ship on the Great Lakes was the Griffin built in Robert Sieur de La Salle in 1679.

el salvador switching all of its currency to the us dollar. where did the dollars come from?

They come from banks in the US. The US doesn't officially sanction other countries using her currency, but you can't keep those slips of paper from going on vacation.

why people with asperger's syndrome are genius or prodigious?

Nobody talks about the ones that become janitors.

why chargers (phone, tablet, computer) get so hot while charging.

Chargers must convert Alternating Current (which is easy to transmit efficiently from the generating station, across the electrical grid, then to your home) to Direct Current (which is easy for digital electronic devices to use to process information). Converting AC to DC is not 100% efficient; some energy is lost--as heat. Properly used and cared for, the chargers' heat output is not dangerous.

In pop culture, there's a lot of resistance to discussing movie/story spoilers without having an appropriate warning. Is this new behavior, or were people equally wary of spoilers for that brand new Shakespeare production?

The concept of a "plot twist" which can be "spoiled" is a fairly recent concept in the history of drama/literature. In Ancient Greece, for instance, everyone knew the all of the legends and their plots forwards and backwards - if you found someone who didn't know that Klytemnestra killed Agamemnon, you'd think them ignorant and remind them of the story. Or take Shakespeare's plays - Iago and Richard III explicitly detail their villainous plans to the audience, it's not concealed like the identity of the murderer in an Agatha Chrstie. In Elizabethan times, a "comedy" meant a play with a happy ending, just as a "tragedy" meant one with a sad one, so even before the audience sat down in the Globe they'd know that *Romeo and Juliet* wasn't going to end well for the lovers. Shakespeare even "spoils" the ending in the Prologue: "A pair of star-crossed lovers take their life." Or take *Robinson Crusoe*, considered the first novel in English. Its full title is *The life and strange surprising adventures of Robinson Crusoe, of York, mariner : who lived eight and twenty years all alone in an uninhabited island on the coast of America, near the mouth of the great River of Oronooque, having been cast on shore by shipwreck, wherein all the men perished but himself, with an account how he was at last as strangely delivered by pirates, also the further adventures, written by himself*. So no one was worrying about giving away the ending, "he gets rescued by pirates" - it's right there in the title! Literature developed, of course, and by the time of novels like *Emma* or *Tom Jones* we see dramatic plot twists, and in *Barchester Towers* (1857), we even have the concept of a "spoiler": > And then how grievous a thing it is to have the pleasure of your novel destroyed by the ill-considered triumph of a previous reader. "Oh, you needn't be alarmed for Augusta; of course she accepts Gustavus in the end." "How very ill-natured you are, Susan," says Kitty with tears in her eyes: "I don't care a bit about it now."

Did the city-states of Greece, like Sparta or Athens, have a concept of "Just War," did they fight with certain rules?

I can give you some answers on this, at least according to Herodotus. The Greeks generally had some rules of war, but they were also great "innovators" when it came to waging war, so sometimes these rules went out the window. A big rule though was not destroying temples, anyone who destroyed the temple of a God would be cursed by the gods. The Athenians are a great example of this, at least according to Herodotus. When they attacked Sardis, they destroyed the temples of the Persians (and the city itself). This offended Zeus, apparently, he sent first Darius against them, and then Xerxes (who was occasional described as being Zeus at least by the Delphi Oracle) who burned Athens, and the acropolis. Gaining revenge for Sardis. The Greeks were sometimes known to sacrifice humans, often slaves or criminals to certain gods - the Titan Chronus would have criminals sacrificed outside city gates, I've heard. But it wasn't a common or well looked up habit. But it did occaisionally happen.

can a body get an infection from a single cell of bacteria or do they need to be in quantity to start an infection?

Yes and yes. Technically, a single cell of bacteria or a single virus can infect you. But, they are far more likely to make you sick if your initial exposure is bigger.

proper eye contact

Use it as an accent to your conversation. If you never look at someone you're either ignoring them or submitting to them, so when you've finished your conversation you stop making eye contact and look away until they get the idea. If you look directly at someone constantly you're either creepy as hell or attempting to dominate them. Make initial eye contact when you first greet someone and hold it for a few seconds while discussing the point of the meeting, this shows interest, respect, and confidence. As you chat you can look away off and on, or just look at different parts of their body (or even face) so that you're not just staring them down. As you make specific points, i.e. saying something you think is important look sharply back into their eyes to drive the point home. I'm often doing more than one thing at a time, so when someone comes into my office I'll glance at my monitor or flip a page of specifications I'm reviewing and then look back at them. Practice it for a while and you'll realize it's really just another way of communicating what you're thinking anyway and it's not all that difficult. The reason you're having trouble is that you're not normally focused on the people speaking to you because of the eyesight issue, so you'll have to make some extra effort. That, or wear your friggin glasses.

Can anyone help decipher this WWII unit from a gravestone?

Edgar's F. Raines's *Eyes of Artillery: The Origins of Modern U.S. Army Aviation in World War II* ([link](_URL_0_)) seems to mention this unit on page 257. According to Raines, during the Battle of Leyte in 1944: > Resupply became the main, but not the only, mission of the [11th Airborne] division's aircraft during the campaign. The division surgeon organized two portable surgical hospitals (parachute), the 5246th and 5247th, which the L-4s [i.e. Piper Cubs] dropped into Manarawat, a small village where [division commander] Swing located his headquarters, and another jungle clearing before airstrips were ready. There, doctors stabilized the division's wounded; then liaison pilots, many of them returning to the coast for more supplies, flew the patients to the rear for long-term care...

{eli5} how do guitar fret harmonics work?

When a guitar string vibrates without anyone pressing the frets, it makes a big wave in the air. How fast the wave moves back and forth is what determines what note you hear. (frequency) When you play a 12th fret harmonic, you put a "damper" at the exact half-way point of the length of the string. This forces the string to vibrate as two smaller waves, each half the length of the string. These halves vibrate exactly twice as fast as the whole string (because math, that's why). When something vibrates twice as fast, the note you hear sounds twice as high. When you play a harmonic at the fifth fret, your "damper" forces the string to vibrate in quarters because the 5th fret is one quarter along the length of the string. There are four little waves along the length of the string, with your finger between the first and second one. This makes the notes you hear even higher, because the shorter string parts vibrate even faster. When you play normally at the 5th fret, the length of the vibrating part of the string is from your finger at the fifth fret all the way down to the end of the string by the fat end of the guitar, which is 3/4 of the total length of the string. When you make a harmonic at the fifth fret, the length of the vibrating string is 1/4 of the length of the guitar (the vibrating string is split into 4 little waves, remember), so you get a much higher note than if you play normally at the same fret. The 7th fret is 1/3 of the fretboard, so the string is split into 3 equal parts, each vibrating equally fast. The vibration is slower than the 5th fret harmonic because the lengths of string are longer (1/3 vs 1/4). The note is lower than the 5th fret harmonic because the vibration is slower. That's why only those frets work to give nice clear harmonics. Those are the ones that divide the string nicely into equal sections (thirds, quarters, halves).

how can you get stuck inside something?

The bones are rigid but the flesh can distort. Moving one direction it may be spread down, becoming narrower; moving in the other direction it may be bunched up, becoming wider.

when pro athletes admit to using ped's (such as ryan braun today), why aren't they arrested for using illegal drugs?

I don't know exactly what drugs were used, but just because a drug is banned from use in sports does not mean it is also illegal to use outside of sports.

How does our brain interpret wildly-different accents as the same language?

Certain sounds within a language are [allophones](_URL_0_). This means that they can be interchanged while not altering the meaning of the word. One example is /t/. If you take nearly any English word with that sound and replace it with an alveolar flap or a glottal stop it changes the accent, but not the meaning of the word.

does it cost internet providers more money to give as an individual faster internet?

Directly... No. Any individual is virtually nothing on the scale that the ISPs operate. Indirectly... Yes. Its not as simple as providing one person faster internet, you would have to provide everyone who asked faster internet. Soon you have to upgrade the entire infrastructure and that costs a few hundred billion.

considering the level of climate change denial and inaction, how on earth was the montreal protocol implemented (and successfully so)?

Don't post loaded questions. Climate change is not in denial, it's the cause of which that is in dispute.

Why hasn't the world's most fascinating monument, the Mausoleum of the First Emperor of China, been excavated?

There are conservation reasons, which I don't have the scientific training to discuss, but I'd like to question your assumption that it is the "world's most fascinating monument". Yes, it is a large and spectacular tomb that probably has a lot of marquee artifacts inside, but those kinds of sites are not always the best to answer interesting research questions. Take for example the archaeological site of Gordion in Turkey, which has been under continuous excavation for 1950. Compared to the likely contents of the Mausoleum of the Qin Emperor it has for the most part been entirely unspectacular with the exception of the large golden burial in Tumulus MM and a few nice artworks. But as a research site it is one of the most important in the entire Middle East, on the level of Bogzakoy, Assur, Warka, Ur and other major sites. It represents one of the longest continuous human habitations known in Anatolia, was the capital city of the Phyrgian state(MM stands for "Midas Mound") and as such has some of the most important Iron Age monumental architecture of Anatolia, important evidence of the Hittite presence in central Anatolia, a notable Hellenistic town that can answer a lot of questions along with other Hellenistic sites about the Greek presence in Anatolia, a lot of plant remains that can tell us about the ecological history and food production of the region, and is generally nearly unparalleled as a laboratory for the archaeology of the ancient Near East. It may not be an enormous mound burying a famous Chinese emperor, but from certain perspectives a site like Gordion(and I pick that only because I know the archaeology of the Near East better than the archaeology of China) that preserves evidence about a wide range of human activities and habitations over a very long period of time is far more valuable as historical evidence. EDIT: And I have not even touched on the humbler settlement archaeology, which for the most part surveys and excavates sites that barely make the front pages but can tell us things about daily life and historical geography that even the most impressive urban monumental site simply cannot.

why dont we ever hear about people born without a sense of taste/touch/smell?

We do. I knew a guy that couldn't feel pain or temperature. He had to be careful not to burn himself and constantly had to check himself to make sure he didn't get injured that day.

How deep would I have to dig into the earth to stop finding life?

Pretty darn deep. If I recall correctly, organisms have been found in boreholes 4km deep, though I can't find a source for anything deeper than 2.7 km. Here is a brief discussion of it: _URL_1_ This is also full of interesting information: _URL_0_

When did pornography come about in human history?

I'm adapting this from some older answers. Here's the tricky thing about your question--do you mean 'porn' in the sense of moving visual art of people doing erotic things? Then in 1894 Edison's studio recorded a vaguely erotic short, titled Carmencita, which featured a Spanish dancer who twirled and posed on film for the first time. The short was considered scandalous in some places because Carmencita's underwear and legs could be seen in the film. A couple of years later, in 1896, the same studio recorded The May Irwin Kiss, an 18 second film of a Victorian couple kissing (in an incredibly awkward and forced manner). According to Maximillien De Lafayette, this scene in particular caused uproar among newspaper editorials, cries for censorship from the Roman Catholic Church, and calls for prosecution—although these calls do not seem like they were followed up on. Or perhaps you mean film of people actually doing the deed? Then the oldest surviving work we have is *L'Ecu d'Or ou la Bonne Auberge*, which was first distributed in 1908--and features a man coming to an inn somewhere in france. The inn has no food, but the inkeeper is desperate for food and offers a very different type of food -- his daughter. And then, just because a third woman has to come and join in on the fun. However, this film only survives in a few places now, censors managed to destroy most copies of this film. The earliest surviving American film, available on [Wikipedia of all places,](_URL_0_) **[THIS LINK IS LITERAL PORN, YOUVE BEEN WARNED]** is called *A Free Ride,* and dates from 1915. These types of works were typically shown in brothels, until film projection equipment became cheap in the 1930s. As with photography before it, and books before that, film eventually became cheaper and more widespread, began appearing in the alleyways and under the counter at stores, and eventually lead to arrests, prosecution and jail time. The Czech movie Ecstasy (1933), for example, featured scenes of nudity, and perhaps the first female orgasm shown in a major theatrical release. The scandal of these scenes lead to cries for the seizing and banning of the offensive material, and lead to the Hayes Code in the United States, which successfully banned erotic material from Hollywood movies for the next 30 years. Full freedom of pornographic expression was not available until 1988's California v. Freeman, which effectively legalized hardcore pornography. Or do you perhaps mean "porn" as in the concept of pornography as a whole? 'Porn' as we know it is a relatively recent thing, dating from the early 1800's or so, 1857 is when it was really written into law in our modern understanding of it (in england and France, a few years earlier in America). So 'porn' as we know it is only about 150 years old! This is really surprising to most people, as they tend to think, as you do, of the Karma Sutra and other things as pornography. But they're not, or at least in their original contexts they were not > “the explicit description or exhibition of sexual subjects or activity in literature, painting, films, etc., in a manner intended to stimulate erotic rather than aesthetic feelings” (OED) Although pornography is a Greek word literally meaning “writers about prostitutes,” it is only found once in surviving Ancient Greek writing, where Arthenaeus comments on an artist that painted portraits of whores or courtesans. The word seemed to fall more or less out of use for fifteen hundred years until the first modern usage of the word (1857) to describe erotic wall paintings uncovered at Pompeii. Several ‘secret museums’ were founded to house the discoveries. However, these museums (the first of which was the Borbonico museum in Naples) were only accessible to highly educated upper-class men, who could understand Latin and Greek and pay the admission price. As literacy rose and the book market developed in England and it began to seem possible that anything might be shown to anyone without control, then the ‘shadowy zone’ of pornography was ‘invented,’ regulating the “consumption of the obscene, so as to exclude the lower classes and women.” (Walter Kendrick, p. 57, *The Secret Museum*) Critics and moralists responded to the growing market, rising literacy, and the developing public sphere by expressing a deep anxiety over the impact and influences of erotic works. Erotic discourse began to be inextricably linked to a ’type’ of work that supposedly had undesirous effects upon the English public. In Lynn Hunt’s words then, “pornography as a regulatory category was invented in response to the perceived menace of the democraticization of culture.”

What's a Good Book To Learn About the Hanseatic League?

Do you read German? If so, get the standard work on the Hanseatic League: *Bracker, Jörgen / Henn, Volker / Postel, Rainer (Eds.): Die Hanse. Lebenswirklichkeit und Mythos, 3rd edition, Lübeck 1999.*, a German language collection of various texts on a diverse range of topics. I don't believe it's been translated though.

What do we know about the long-term effects of nicotine, as distinct from the long-term effects of tobacco?

We do not have long term human studies yet. However, we have done studies in rats (so take that as you will). Findings from one such study show that long term, heavy usage (twice the blood plasma level of nicotine found in heavy smokers) show **no increase "in mortality, in atherosclerosis or frequency of tumors in these rats compared with controls"**. Nicotine is still very addictive, and the electronic cigs so far haven't shown benefits in quiting, but if your friends choose e-cgis over regular, it is likely a healthier option. Source [pubmed](_URL_0_)

Did the ancient Romans have a system for writing music?

They used the old Greek letter notation as well as Greek music theory. This was, as far as we can tell, a matter for the educated in theorising about music, rather than a tool for musicians to help remember and communicate musical ideas. One of the best preserved antique pieces of music is from the roman period, but it is culturally Greek rather than Roman. [Seikilos Epitaph](_URL_0_), which was inscribed on a tombstone found in what is now Turkey. As far as I am aware, we have no evidence in the form of written down music of how music may have sounded in the city of Rome, though it surely changed a lot over the centuries.

Timothy Snyder states that there is no official French history of WW2 because "more French soldiers fought on the Axis side than the Allied side."- Is this true?

So I'm not entirely sure that Snyder is being serious there? Right after he states it, he then goes on to say "OK, you didn't think that was as funny as I did." If he *is* serious, well, it is an hilarious silly thing to state. At the outbreak of war, France was able to mobilize roughly 5 *million* soldiers, across the three main forces it controlled - Metropolitan Army, Army of Africa, and the Colonial Troops. By the invasion of France, 94 Divisions were operational in France. Frenchmen certainly fought in the German military, but not in number anywhere near that for the Allies. The 33rd Wafffen-SS Division Charlemagne, saw only in the ballpark of 10,000 men (in my brief look about, sources seem in marked disagreement on the exact number), and the 638th Infantry Regiment - "Legion of French Volunteers Against Bolshevism" - adds a few thousand more to that number. Even if we are incredibly charitable and count the 100,000 men of the Vichy Army of the Armistice, and the Vichy-era's 225,000 men of the Army of Africa, we still are woefully short of reaching the number of french soldiers fighting for the Allies in early 1940. And if we don't want to count that, and *just* look at the Free French, even the initial Free French Forces numbered about 7,000 soldiers and 3,600 sailors, which is not exactly puny compared to the numbers above not counting Vichy, and by mid-1944, the Free French numbered 400,000 men. We can split hairs over whether they were "Frenchmen", since a large part of the force was drawn from French Colonial possessions, so included men we would perhaps instead refer to as Algerian or Senegalese, but the original Army in France in 1940 had a strong minority of Colonial troops anyways, and not counting them would seem to discount their contribution and sacrifices. So in short, while I again seem to read him as making a joke, and his actual point seems to be about the sacrifices of Ukrainians versus those of the French, France had literally millions of men serving in the Allied forces in 1940, and the Free French were nearing half a million later in the war, which certainly dwarfs the French formations within the German military. Numbers mostly taken from Encyclopedia of World War II ed. Alan Axelrod, also "La Grande Armeé in Field Gray’: The Legion of French Volunteers Against Bolshevism, 1941" by Oleg Beyda and "Hitler's Gauls" by Jonathan Trigg

With high magnification and low exposure, can telescopes see the shape of the nearest stars to the Sun (like the Alpha Centauri system, or Barnard's Star)? Or are these stars still too far away and appear only as points?

Larger stars can be resolved, for example [Betelgeuse](_URL_0_). Sirius, a large and close star, when imaged with Hubble, basically looks like a point spread function. _URL_1_

how is it decided whether someone is sane or insane during a trial?

During a trial, the final decision lies with the jury (assuming you are talking about the US court system) Since Reagan signed Insanity Defense Reform Act in 1984, it is up to defense that to prove that the defendant was not sane. Both sides can call upon so called expert witnesses (someone who is specialised in a particular field and can therefore provide information) who give their opinion on the mental state of the defendant. This is generally done at the hand of interviews and possibly studying things like writings they left beforehand. There are different standards and tests for criminal insanity, which vary from state to state. Mainly, it is all focused on whether or not someone was able to understand what they were doing at the time/was able to understand the consequences. This is a much more narrow definition than mental illness outside of the criminal justice system. Someone can be mentally ill (for example, due to depression or anxiety) but that doesn't necesarily also make them criminally insane. In any case, the insanity defense is a very rare thing to pursue (used in less than 1% of all cases) and very often doesn't exactly lead to people going 'free'. Rather, they go to a mental health facility where they can actually get help for their problems.