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Why is Greenland almost fully glaciated while most of Northern Canada is not at same latitude? | Average temperature is correlated with latitude, but it is not directly controlled by it. See [this map](_URL_0_) of average temperature across the globe.
How hot and cold air are able to move across land matters a lot. So things like plains and mountains change where the air can go. Ocean temperature also matters, an... |
If I dropped a lamp into a black hole and a photon left the lamp travelling *exactly* away from the singularity, after the lamp had passed the event horizon, would the photon slow down or leave the black hole? | If the lamp has crossed the event horizon, there is no direction leaving away from the singularity. The singularity is not a point in space but more of an instant in time in the future. All photon trajectories starting from the lamp end up in the singularity. |
What happened when black diplomats went to Rhodesia, South Africa, or Jim Crow United States? | There were fascinating conflicts and confrontations on all sides. Let's start with the United States.
Until 1961, the U.S. State Department relied on its Office of Security to provide escorts for visiting diplomats and dignitaries. Before the 1960s, foreign visits weren't all that common. Transportation technology was... |
Why does the speed of light(299,792,458 m/s, a finite number) require an infinite amount of energy to reach? | One of the postulates of special relativity is that the speed of light is invariant across reference frames. (The first evidence for this postulate was provided by the Michelson-Morley experiment.) The postulate means the following. Suppose you are travelling at 0.99*c* with respect to me, and you emit a light signal. ... |
I saw a video of someone breathing in a rag of chloroform and getting instantly knocked out. I don’t think that’s real, but it made me curious. How does chloroform work? And what exactly does it do? | Using chloroform to knock someone out in a matter of seconds is entirely fiction.
Chloroform is basically an anesthetic--but one that is no longer used due to the fact that it can seriously damage your liver and heart. Even with perfect dosing, it would take at least 5 minutes of breathing it to knock someone unconsci... |
Would it have been socially acceptable in late Republican Rome for a Senator (or a prominent Roman male) to be exclusively homosexual? No marriage with a woman, no children, just exclusively and openly in relationships with other males? | You partly answer your own question with your understanding of Roman views on penetration; a senator who was purely (and willingly) receptive would be viewed as a *cinaedus* and thus utterly shameful. More interesting to consider, however, is the apparently unusual idea that a *vir* would be only interested in one sex... |
What was the impression of the AK-47/AKM when it was first encountered during the Vietnam War? | The Kalashnikov was fairly rare early in the war. I believe that it began to be encountered in significant numbers around 1965, especially with NVA forces, but did not become entirely ubiquitous, especially among the Viet Cong, until somewhat later. Various other small arms were used, especially the SKS semi-automatic,... |
If iron loses it's magnetism around 800 degrees C, how can the earth's core, at ~6000 degrees C, be magnetic? | [Dynamo Theory](_URL_0_). Quote:
_"In this dynamo mechanism, fluid motion in the Earth's outer core moves conducting material (liquid iron) across an already existing, weak magnetic field and generates an electric current. The electric current, in turn, produces a magnetic field that also interacts with the fluid moti... |
how were operating systems developed? wouldn't a preexisting one need to be in place to type the code? | Programs don't really need an operating system to run, you can have a program that lets you program without being something we would call an operating system.
The very first program would have been loaded onto the system by hand. Basically you write it in assembly (on paper), then by hand convert it to binary, and the... |
why do a lot of companies develop apps for ios first, when android holds 70% of the 'smart' market? (inspired by the new reddit ios app) | For many reasons, but the most obvious commercial reason is this:
iOS users consistently spend more money buying apps, and buying in-app purchases, than Android users. Even though there are more Android users than iOS users, they spend less money. |
Native American names like "Wyoming", "Miami" and "Wabash" have been applied to areas of the United States hundreds and thousands of miles away from the tribes whose languages they came from. Why? | In early colonial times a lot of European explorers recorded Native American Indian (I'll just say "Indian" after this) names for places and these became a normal part of the named American landscape. In later colonial times and through the Revolutionary era Indian names generally fell out of fashion, as a lot of settl... |
Would it be possible to 3d print a set of fingerprints to "wear" over your own? | I'll start by saying I'm not culpable for whatever you do with this information, I'm just words on the internet.
With that out of the way, I'm sure this is easily possible, and [there's actually been some serious scientific work on developing this method for forensics applications.](_URL_1_) If you're any good at for... |
Was there ever any attempt by the Anglo-saxon kingdoms of the British isles to seek help from the Angles and Saxons of the continent during the viking age? | In short, no. The "Angles" and "Saxons" had no reason to help their insular cousins, lacked the capability to do so, and were no longer really operating in the same capacity across the North Sea as they had in centuries prior. For the sake of simplicity I will keep the usage of Angle and Saxon, but it is worth mentio... |
if it's illegal to use cellphones while driving for non hands free calling, why is it legal for truck drivers to use radios for communicating in the same way? | The fear with a cell phone is that you have to look at it while you use it, even for a short period of time. A truck driver is so use to picking up the radio it is literally muscle memory for them to do that task. While there is a learning curve for the truck driver it is something that becomes safer as they train the ... |
All I heard the day of the eclipse was NOT to look at the sun directly or you'll get permanent, noticeable eye damage. I believe that's hyperbolic, like saying smoking one cigarette will give you lung cancer. What is the likelihood of permanent noticeable eye damage? | You can get permanent eye damage from a single exposure to intense UV light, no doubt about it. (I got permanent damage to one retina by a short accidental look at a hollow-cathode lamp in a AAS spectrometer)
Your analogy to cigarettes is plain wrong. Cancer is usually caused by probabilities and _cumulative_ DNA dama... |
Were there any gym-like locations in Ancient Rome or Greece where people would go and workout? | Yes. The term gymnasium is actually derived form the greek work gymnos. Most greek and roman communities would have a gymnasium where people would engage in athletics such as wrestling (completely in the nude). These structures were large, open air facilities(think of a modern stadium). Over time, gymnasiums became ... |
Americans often say that older generations didn't express emotion like we do nowadays and that's why PTSD wasn't discussed. The Korean and Vietnam wars took place less than a decade from each other, however, and Vietnam is seen as a conflict that resulted in more soldiers with PTSD. Why is that? | In reality, 20 years separated the armistice of the Korean War (1953) from the last American troops leaving South Vietnam (1973). The answer to this question lies not in the nature of the conflicts, but rather what happened to the veterans *after* the conflicts.
During and after the end of the Korean War, many veteran... |
why do all (or most) languages capitalize the first letter of a sentence? | Not all languages do, as you know, but we can be more specific than that. Nearly all of the languages that *do* capitalize the first letter of a sentence (or *any* letters at all, really) are those that use the [Latin alphabet](_URL_0_). The reason most of those languages capitalize has a lot to do with the historical ... |
how/why does a salt water rinse work to clean out nasal passages, help a sore throat, or clean sores in the mouth? | Edit: It has been made clear to me that I was mistaken and I therefore retract my statement and apologize to anyone I may have offered by my error.
As I understand it a sore throat is most commonly caused by bacteria and by adding salt to water we make what is essentially a toxic environment and kills the bacteria an... |
If table salt separates into Sodium and Chlorine ions when dissolved in water, then how does salt water taste like salt? | When you are tasting table salt (NaCl), you are not tasting the compound NaCl, but rather the constituent ions Na^(+) and Cl^(-). In fact, it's more accurate to represent the ions as (Na^(+))aq and (Cl^(-))aq where the aq stands for aqueous and indicates that the ions are solvated by water, since the salt will be disso... |
Is there a point after quitting nicotine where the chemical addiction is back to that of a life-time non-smoker? | The brain goes through chemical changes after years of using addictive substances. These changes seem to be irreversible, the changes to chemical receptors in the brain, coupled with habituation, are reasons why a person becomes addicited in the first place. There is a saying in NA circles "Once an addict, always an ad... |
why are there multiple methods for measuring electricity? (volts, amps, watts, etc.) | They mean different things. Instead of electrons, imagine you're measuring a water pipe.
How wide is it? That's resistance.
How much pressure is inside? That's voltage.
How fast is the water flowing? That's amperage.
The water is turning a waterwheel as it passes, how much energy is that using? That's wattage. |
I have finally convinced my fiercely nationalistic father to read a book of my choice on the Armenian genocide. Could you recommend me a book that both makes compelling historically sound arguments that also doesn’t demonize Turks. | How about something by Taner Akçam, who is well-known as a Turkish scholar who acknowledges the Armenian Genocide? Being Turkish, you will avoid the anti-Turkish subtext of some other historians, and he's also an academic and treats the subject accordingly.
The work of his that I have read and which both documents the... |
What sort of factors led Athens to survive from antiquity until today, but not Sparta? | Sparta did survive. I actually visited it in 2007 on one of my Greek tours. It is a tiny settlement right near the ancient ruins of the town. Athens itself was a tiny settlement as well prior to its major urban expansion in the 1900s. Sparta never experienced this due to Athens being selected as the Greek capital.
OK,... |
Has there ever been a republican or democratic nomination that was decided by super delegates that went AGAINST the popular vote? | The biggest reason we have the current system of binding primaries and caucuses is because the 1968 Democratic nomination process was a total balagan. We have a sitting Democratic president running for reelection--one who's even done quite good stuff in his Great Society Program and on the Civil Rights front, but whos... |
What actually happened to cause the Bosnian War, and what were some of the main events during the conflict? | The Bosnian War was part of a larger series of wars surrounding the breakup of Yugoslavia, which included relatively large wars in Croatia and Kosovo, and smaller ones in Slovenia and Macedonia. The war in Bosnia actually didn't start until almost a year after the outbreak of war in Croatia, so it's necessary to look a... |
I am a soldier who dies while on Crusade. How does my family find out? | > “He is dead, dead, and the world and everything that is sweet in the world is dead to me!”
This was the reaction of St. Elisabeth of Thuringia when her husband, Ludwig IV, Landgrave of Thuringia, died during Emperor Frederick II’s crusade in 1227. In this case he didn’t actually die on the crusade, he died in Italy... |
Did mainstream audiences in the 70s & 80s really not know Freddie Mercury was gay (/bi)? | Broadly speaking, the English press played a big role in creating early perceptions of Queen, and they saw Queen as copyists trying to follow Led Zeppelin's path (both musically and career-wise), who seemed to have a lot of financial backing. Said Nick Kent in a scathing 1974 review of their self-titled album:
> ...... |
is 'race' a scientifically accurate term to use, given humans have only one species and there are no taxonomic differences amongst them? | The answer is no. Race is a social construct which doesn't exist in the physical world. The idea of race as more than a cultural concept is pretty much rejected scientifically. Here's the American Anthropological Association's [statement on race](_URL_2_).
America's last President had a "white" mother and a "black" fa... |
why when i'm hungover do i not seem to want water/food even though i need it and will make me feel better? | To specifically address the lack of appetite, it's usually inflammation-related. Alcohol irritates the lining of the stomach and intestine. The brain takes those sensory signals and says "something's not right in the GI tract, let's not put anything else in there until we're sure everything is ok".
Alcohol also affe... |
If livers regenerate, would it be possible for me to donate half my liver, grow it back, then donate it again? If so, how many times can one repeat this process? | No, you can only donate your liver once, mostly limited by the fact that not just any part of the liver can be sliced off and be able to fully regrow. There are two (main) lobes in the liver and each has a full set of connections needed to connect to the rest of the body (an artery, vein and bile duct). They take one o... |
what is happening culturally in china that can account for their poor reputation as tourists or immigrants elsewhere in the world? [this is a genuine question so i am not interested in racist or hateful replies.] | From my super basic understanding (I'm more than happy to be told how wrong I am!):
Its something to do with the way the class system works. In the Communist society there is less natural class distinctions and social conventions that go with a non-communist society. Therefore a big part of how people display class an... |
This is short sword found by my family
member at least 50 years ago. Is it genuine? | That's a Late Bronze Age 'vollgriff' type sword. If it's genuine, you should definitely contact an archaeologist. I'm quite excited by this, so let me first post this before I edit it into something long:
I suspect it could be a reproduction cast. The metal looks a bit too dark (real bronze age swords used 10-15% tin,... |
How is the universe (at least) 46 billion light years across, when it has only existed for 13.8 billion years? | The universe appears to be infinite in size, ever since the Big Bang - although what happens during and/or before the Big Bang is still very strongly under debate. The expansion of the universe is not the expansion of the *edges* of the universe - it's just that everything within the universe is getting further from ev... |
Did FDR, Churchill or Stalin ever communicate directly with Hitler during WWII? Phone? Telegram? | Stalin and Hitler never met, nor did they ever actually talk to each other. The same goes for Churchill and FDR who never talked to Hitler either. The only allied leader that I can think of who actually met and talked with Hitler and then later fought him in World War Two was Canada's prime minister, William Lyon Macke... |
Where did the lore of trolls, elves, dwarfs etc originate from? Are they from the same source or time period? | This is a difficult question to answer. First a minor point of clarification: the term "troll" can mean many things depending on the location in Scandinavia. I think it is safe to assume that you are referring to the array of supernatural beings that figure in popular fantasy literature and films and that the trolls yo... |
Were lowborns and low-ranking knights generally punished or rewarded for killing high-ranking nobility in battle? | I can't find the video online, but the special [*Going Medieval*](_URL_3_), presented by [Mike Loades](_URL_2_), covers aspects of this. He begins discussing singles combat at 5:20, I typed out the transcript below:
> **Loades**: What would happen in a battle is the crush of men from either side squeezes you in… T... |
how is that cover bands in bars are allowed to play other band's song for profit (getting paid by the bar) and don't have to pay for licensing like they would in commercials/movies/reproductions/etc.? | In the US, the bar pays a fee to ASCAP (American Society of Composers, Authors and Publishers) for the performance rights. If they haven't payed that fee, they can't host bands that play covers. [Here's ASCAP's FAQ about the situation.](_URL_0_)
**Edit:**
Yes, there's also BMI and SESAC. I have been informed, thank yo... |
I've heard that during the First and Second World Wars many soldiers would deliberately miss their shots when shooting at enemy soldiers. Is there any truth to this? Did it vary from army to army, or war to war? | There has been a lot of discussion about this, mostly inspired by Dave Grossman's *On Killing: The Psychological Cost of Learning to Kill in war and Society* and a number of other books such as Melanie Joy's *Unnatural Born Killers*.
Opinion on the validity of these claims is divided to say the least and hence there i... |
How did the world leaders and people of the day actually react to George Washington's relinquishing of power and refusal to crown himself a king? | This article from the *Boston Globe*'s "Ideas" section doesn't address leaving power at all, or Europeans, but you may still find it interesting. It focuses on Washington's taking power, and specifically the debates about which honorific to use with the Presidency: "[His Elective Highness, President Barack Obama](_URL_... |
Given that Pre-Islamic Arabia was a very women-friendly and sexually "liberal" society, what is the source of Islam's extremely puritanical culture? | I think you're vastly overstating Pre-Islamic Arabia's "very" women-friendly and sexually liberal society.
> In Robert G. Holyland's Arabia and the Arabs, various historical sources are mentioned that tell us pre-Islamic Arabian culture was one in which women could marry multiple men, advertise for mercenary husban... |
How is it that figure skaters can spin a hundred or so times during a performance and skate just fine, and yet I get dizzy after spinning my child ten or so times? | It turns out that [yes](_URL_1_) you can train yourself to get less dizzy. [Here's](_URL_0_) a much more readable summary of that paper by the way. In short, it says that over years of practice, ballet dancers can train their brain to be less susceptible to dizziness. In this case I think it's fair to assume that a ... |
why bleach and products containing oxygen (like h2o2) have the power to whitening things? | They break down organic compounds very very easily. Most dyes and pigments are based on organic compounds, if I remember they are mostly dinitrile amines (or that was a key ingredient, I’ve tried to block my organic chem class from my mind).
So basically its a long chain organic compound and the charged oxygen is rea... |
during opening credits of a tv show, all of the actors and actresses names appear at the bottom of the screen but the last person getting the credit gets a special "derp mcderpison as steve" credit. why is that? | Contracts. If given the choice, all the actors would want more money for appearing in a show. The unions generally set the pay scale, so more money is out. The next thing the actor wants is more work. More work means more money. The easiest way to get more work is to have more people know your name. So an actor would l... |
why do men play baseball, but women play softball? what is the difference? | Softball was invented in a windy day in 1887 in Chicago, Ill., by a group of men waiting for results of the Harvard-Yale football game. While they were waiting, they turned a glove tied together into a large ball, with a broomstick as the bat. It was first regarded as a way to play baseball indoors, and after it gained... |
after recently seeing an article about laser technology uncovering a lost african city, why can't we use that technology to map the paris catacombs? | [LIDAR] (_URL_1_) works by flying a plane over the area you want to map and bouncing a scanning laser off the ground. The laser light can get enough back scatter through vegetation to map what's underneath. But lasers can't see through dirt, pavement, stone, or buildings. Some type of [geophysical imaging](_URL_0_) mig... |
If Hitler wanted to create a Third Reich, what were the First and Second Reich? Was there a particular aspect of the previous Reichs he wanted to recreate? | The First Reich was the Holy Roman Empire (Heiliges Römisches Reich), and the Second Reich was the German Empire (Deutsches Reich, or the Kaiserreich). Mainly, he was seeking to emulate a strong, united, "German" Germany, that was able to forge her own destiny and become a powerful player in world affairs. |
we can freeze human sperm and eggs indefinitely, without "killing" them. why can't we do the same for whole people, or even just organs? | Because sperm and eggs are just single cells. Organs and organisms are collections of cells that must operate in unison or the entire organism dies.
If you have 5 million sperm cells and your freezing/thawing process kills half of them, you still have 2.5 million viable sperm cells to rely on, and only need one for su... |
When you're running and you get a stitch, what is actually happening? And what causes it? | This phenomenon is known as '[exercise-related transient abdominal pain](_URL_1_)' (ETAP), and unfortunately while a number of theories exist we don't know definitively what its cause is. The [leading hypotheses](_URL_3_) include 1) diaphragmatic ischemia, 2) peritoneal irritation, and 3) stress on ligaments supportin... |
What was going on in America that caused the Founding Fathers to create the Second Amendment and sign it into law? | This is a complex question that I’ll need to supply a lot of context for in order to answer it. Sources are in my direct reply.
**Firearm Ownership in Pre-Revolutionary America**
Firearms were quite common in the American colonies during the 17th century. Based on data of a survey conducted in New England in 1775,... |
What "ended" the Satanic Panic of the 80s, regarding heavy metal, Dungeons and Dragons, etc? | The delightful answer is that we don't really know. Yet.
I'd like to talk about *why*.
Reichert and Richardson's (R & R 2012) article "Decline of a Moral Panic: A Social Psychological and Socio-Legal Examination of the Current
Status of Satanism" is actually about the *survival* of fears of Satanism, played out in cu... |
Do we actually know were the center of the universe is located? Do we know where we are in the entire universe? | In at least one sense, there is no center of the universe. Everywhere we look, galaxies are moving away from each other. One analogy involves a balloon...take an un-inflated balloon and draw some dots all over it with a sharpie...those are galaxies. Our universe exists *only* on the surface of the balloon. Now slowly i... |
How accurate are our measurements about the size of the universe, the distance to the sun, etc? | A lot of measuring of far off objects comes from finding standard candles and then basing measurements of adjacent objects off of that standard measurement. Typically, as long as the initial measurement of the standard candle does not have any unforeseen variables (such as a giant cloud of gas in the way that was other... |
why do the effects in older movies (some not even 10 years old yet) seem so cheesy now yet back when the movie was released it seem so real! | When we haven't experienced something that much, we pay less attention to the details.
If we ate bacon for the first time, we'd get blown away by the taste no matter how it was cooked or where it's from - it's unique, delicious and memorable. After eating it every day for a month, we might develop a preference for how... |
How historically accurate is that Anne Boleyn slept with her brother ( George Boleyn) or was it used to have her arrested for treason? | This is one of those things that we can really never know for certain. But, the incestuous nature of George and Anne's relationship was believed by many at the time and was an easy way out for Henry VIII.
As you know, Henry went through a LOT of trouble to put aside Katherine in favor of the younger (and hopefully mor... |
In modern strategy games, it is easy to see if you are winning or losing a battle, because the game simply tells you. But how did foot soldiers and officers discern victory and defeat during the heat of battle? How did they evaluate if they should retreat or stand their ground? | During the Napoleonic Wars, there were three main factors that helped armies determine if the day had gone against them: the presence of strong forces in reserve, the safety of the line of retreat, and the possession of ground.
During the Wars of the French Revolution, war, battle, and combat changed dramatically, e... |
Quarterstaff combat is all over fantasy games, were quarterstaves ever used in real combat? If so, where, when, and how? | > The short staff [ie. quarterstaff] or half pike, forest bill, partisan, or glaive, or such like weapons of perfect length, have the advantage against the battle axe, the halberd, the black bill, the two handed sword, the sword and target, and are too hard for two swords and daggers, or two rapier and poniards with ga... |
When did "sleeping" evolve? What are the most primitive organisms that we know of that sleep? | Tangent question, is sleep what evolved or the state of being awake? As in, did multicellular organisms first evolve to walk around, eat, reproduce, then sleep and recover.. or did they evolve to stay in a neutral state then get up, eat, and reproduce? |
explain the weird sensation i often have after driving where i literally can't remember how i got to my destination. is there an actual term for this or am i just crazy? | Yes, it's called highway hypnosis. The theory is that you kind of put your brain on autopilot because there's so little going on and so much of it is muscle memory. Your brain splits its consciousness and assigns just enough to drive and the rest thinks about other "more important" stuff.
As you can imagine, this is p... |
Why was Pol Pot never prosecuted for war crimes? Why was his government still recognized by the United Nations after they knew the atrocities he committed? | There is some debate over whether he killed himself or was killed by his fellow Khmer Rouge while in custody. He never made it to trial. Several of his comrades did go to trial and were convicted of crimes against humanity. The Khmer Rouge were recognized by the rest of the world (most of the western world including th... |
why do our eyeballs roll up involuntarily while we sleep, but its stressful to do so voluntarily when awake? | Correction: your eyes roll up when you close your eyes
I think it’s called the bell’s reflex
The nerves that control eye closure are intrinsically linked to the nerves that control upward eye movement and hence produce this reflex
Purpose is obvious. To help protect your eyes when they’re not needed. |
What did boat drivers do after landing in Normandy? Did they stay on the boats, or they helped on the beachs? And what about boat gunners? Did they dismount the machinegun, or left it on the boat? | In general, small boats, i.e. higgins boats, backed off from the beach and returned to the ships they launched from in order to bring in subsequent assault waves. Landing craft were a valuable asset for logistical support in the days after the landing and were preserved when possible.
There are exceptions to this,... |
Did the atomic bombs help end the war? I've always believed they did but current article claims they did not. | Kuznick is an advocate of what might be negatively called an extremely "revisionist" position on the atomic bombings. This argument is not a new one — the question of whether the atomic bombs ended the war or were necessary to end the war [has been debated since the 1940s](_URL_0_), but got more steam in the late and p... |
what differences in brain structure/function cause depression, and how do antidepressants help? i've been told we don't *fully* understand the science yet, but what do we know so far? | Generally speaking, depression is associated with low levels of dopamine, norepinephrine, and serotonin in certain parts of the brain. Having a balance of each is essential to “normal” functioning. Antidepressants such as SSRIs handle the serotonin, MAOIs prevent the breakdown of dopamine, and tricyclic antidepressants... |
why are ancient names like those belonged to the pharaohs so different, where do they come from, and what do they mean? | Probably most Ancient Egyptian names would sound alien to us, as they are from a language that evolved over a nearly 2,000 year span which predates most modern languages and which is only now used in very, very limited Coptic religious circles.
In reality, the word "Tutankhamun" is nothing too foreign - it means "Livi... |
Possibly a dumb question but here we go; There have been multiple female absolute monarchs in history who had total power over the laws, why didn’t they just make total gender equality laws and then enforce them? | **Short answer:**
Not a dumb question-- it's one whose answer gets to the heart of medieval and early modern ideas about political power. Don't assume that "people then" thought like "people now", or that power was ever really absolute.
**Discussion:**
Variations of this question have been asked before. You make an... |
If we could travel at 99.9% the speed of light, it would take 4 years to get to Alpha Centauri. Would the people on the spaceship feel like they were stuck on board for 4 years or would it feel shorter for them? | It would appear to be nearly instant from their point of view. Light traveling at the speed of light arrives at the same time that it left from its perspective. There would be far more time spent accelerating and accelerating at a rate a human could handle than there would be at .999 c. If accelerating at 322 ft/s2 (10... |
Is it possible there were civilizations 10 or 20 thousands years ago that are lost? Or is it generally accepted fact that the first civilizations started around 5,000 years ago? | Gobekli Tepe in Turkey is a site that appears to have been in use sometime between the 10th and 8th Millenium BCE. It's a fascinating site that may upend some of our prior notions of how civilization developed - but much work needs to be done on the site before we get any real answers. And of course we may never get th... |
Why has nobody come close to Tesla's inventions that were created up to 100 years ago? | While Nikola Tesla was a very smart and accomplished inventor, many of his ideas and inventions simply didn't work out the way he had imagined it. Tesla has gained a reputation as some kind of visionary whose ideas have, for some reason, not been followed up on.
But this isn't true. Tesla's ideas have been studied ext... |
Will there ever be a way to define division by zero, similar to how we defined roots of negative numbers with the imaginary element i? | You can define anything as anything, as long as it's consistent with your axioms and previous definitions. Whether it's useful is the question.
If 1/0 = a where a is an integer, then by the usual algebra we'd have 0*a = 1. But that doesn't really make sense in the context of the usual multiplication concept, and inste... |
What happens to the 0.01% of bacteria that isnt killed by wipes/cleaners? Are they injured or disabled? | Ok, so I work in the industry of antimicrobial testing, and no, it's not a legal disclaimer, we test and see how much of a log reduction a product gets and we literally scrub the shit out of the device or surface or whatever, so no, it's not a CYA claim, it is based on actual FDA or EPA regulated testing on very specif... |
when i shoot somebody in a video game, is there an actual bullet flying through the air? or is that just added light effects i'm seeing. | It depends on the game or weapon. Some use what's called "hitscan," which is similar to your laser beam example: when the weapon is fired, the bullet is treated as a straight line that appears instantaneously. A hit is registered when that line intersects with the target.
Bullets can also be programmed as actual proje... |
In the novel "Go Set a Watchman," Jean-Louise and her uncle are having a conversation about the causes of the Civil War and her uncle says, "not much more than five per cent of the South's population ever saw a slave, much less owned one." Is there any truth to that? | **No.** It's absolute baloney and incredibly racist.
The 1860 U.S. Census found that 40 percent of the population of the South *was enslaved.* I'm quite sure that they were aware, every single day of their lives, of their status as a slave.
But let's take the racist's point of view. Let's say a slave isn't a person a... |
why buy an expensive computer monitor if a hdtv of the same size is cheaper and has the same resolution? | Monitors have better response times, more accurate colours and some even have features like USB hubs.
TV's don't have fast response times and therefore have a lot of input lag, which is fine for movies and such, but for applications and games, monitors are better. TV's process the image to try and make it look as goo... |
What happened to the land and the debris of war such as weapons and vehicles that were left after long and destructive battles like Verdun or Stalingrad? Basically, who cleaned up the mess and how did they do it? | Note that many areas which have seen prolonged fighting in modern wars *haven't* been completely cleaned up, with some still containing dangers such as live explosives.
With this in mind, I'd like to ask a follow-up question: which areas have seen prolonged fighting with significant leftover debris/ordnance that *was*... |
Do ticks or other blood sucking bugs (mosquitoes, etc) show preference to certain people? | Yes.
Both ticks and mosquitoes tend to target people by detecting the CO2 they release from their bodies, so perhaps your metabolic rate is higher than average and produces more carbon dioxide. Blood type O is preferred over A and B for them as well. Additionally, it could be that you were walking in front of them and ... |
Are "king" and "sultan" completely analogous titles? How would a high medieval king differ differ from a sultan of the time? | My indirect/incomplete answer is of a linguistic nature, but maybe it will be found useful/interesting. It should be noted that the Arabic word for king is not sultan (سلطان) but *malik* (ملك).
In Arabic, nouns are (almost always) derived from verbs which go back to (almost always) three letter roots.
* Sultan deriv... |
How "serious" were religious beliefs in ancient Greece and the Roman Empire, and what role did they actually play in everyday life? | You might find these previous discussions useful:
* [Were there religious fundamentalists in ancient Greece and Rome?](_URL_3_)
* [Did Romans really believe that Emperors were gods?](_URL_2_)
* [What did religion mean in ancient greece and rome?](_URL_0_)
* [Were there religious cults in ancient Rome and Greece?](_URL... |
Could you have a binary set of moons that orbit a planet together? Not 2 moons in separate orbits, but a pair or moons rotating around each other and orbiting a planet as well. | These orbits are very difficult to get. The two moons would need to be quite far from the planet, the planet would need to be far from its star (the planet would need a very large Hill Sphere, like Neptune).
In such a situation, a binary moon would be stable.
How it would form is another matter. The angular momentum ... |
A substantial number of slaves brought to the Americas were Muslim. What remnants of pre-colonial Islam survived in black diaspora communities though colonialism? | Hey there! Interesting question. I am not qualified to speak on the remenants of Islam and it’s intigration into Caribbean, Centeral American, or South American culture. I am quite familiar with American slavery and Muslims who lived in those communities, so I will primarily address that point. Hopefully someone else c... |
why are 9mm bullets less dangerous than 7.62 or even 5.56 ones? shouldn’t they deal more damage with bigger size? | 9mm bullets are dangerous.
However they are a handgun round. They're less aerodynamic and have less power coming out of the barrel. They're not designed for long-distance flight.
7.62/.308 and 5.56/.223 are rifle rounds. They have more power out the barrel and are designed for long- distance, accurate engagement. |
If all the salt in the oceans was removed and made into a single cube, how big would the cube be? | The oceans hold 97% of the Earth's water (see [this](_URL_1_) from NOAA), so we can safely just look at the oceans to consider how much saltwater there is.
From [another](_URL_1_) NOAA page, we find there are 1.4x10^(21) liters of water.
[Here](_URL_2_) we see there are about 35 grams of salt in each liter of ocean w... |
Modern courts have faced the problem of the "CSI effect" (Where jurors expect incontrovertible scientific evidence like they uncover in the show). Was there a similar problem of high expectations in the late-Victorian age following the popularity of the Sherlock Holmes stories? | In a way, yes. But not exactly in the way you describe. The popularity of Sherlock Holmes and other crime dramas led to more understanding of how to examine crimes. In some cases, it even *improved* the investigations of crime.
Much as the Sherlock Holmes stories came to the public, so too did the public's investigat... |
how do magnets form, and why/ how do they do what they do? | All matter is made out of atoms. An atom can be thought of as a small nucleus of material around which orbit even smaller particles of matter called electrons. The electrons have an electrical charge, so when they orbit they form small loops of electrical current around each nucleus. Magnetic fields are formed by elect... |
how are news agencies allowed to outright spread lies or misinformation to the public? why is there no system of moderation to license news reporters similar to how engineers/doctors are licensed to design buildings or treat patients? | Who would do the moderation? The government? This is what happens in some countries, such as Russia and the UAE, and the governments in those countries influence the news to suit their own agenda.
The UK had an independent Press Complaints Commission which does try to keep the news sane, even if that means censuring ... |
[Biology] What causes some people to be more prone to headaches than others? | There are a lot of different types of headaches, and like almost every trait, both genetic background and environment play in role. It's also a hard question, because some of the most common types of headache, including migraines, are not perfectly understood yet.
For example, there is a heritable component to frequen... |
Are there any accounts of a battle ending with only 1 or 2 men on both sides? | There was a battle called "The Battle of 300 Champions" which took place between Sparta and Argos in 546 BC. There were only three survivors: two on the Argive side and one on the Spartan side. The two Argives assumed they were victorious and left the field. The sole surviving Spartan claimed otherwise since he had rem... |
Why do Intel's next gen processors have lower clock-rate (~1.7GHz or ~1.9GHz) ? | > But what if you absolutely need higher clock rate
This is why CPU manufacturers release a wide variety of processor models. From what I could find, Intel's Broadwell architecture (which I assume is what you're referring to) offers models with base clock speeds ranging from 1.6 GHz to 3.1 GHz, capable of "turbo boo... |
How different was Mao's communism from Marx's commuism? What about the Russian figureheads like Stalin, Trotsky, or Lenin? | One of the biggest difficulties with this is that Marx is a little light on Revolutionary theory, so much so that philosophers and historians still disagree about whether he advocated violent revolution or not. The Communist Manifesto is a slim thing, about thirty or forty pages, and is decidedly inevitablist in its to... |
female voices are higher pitch than male voices, so why can you still hear the difference between a male and female voice when they sing the exact same note for example? | Gonna give this a to the best of my non-scientific knowledge shot.
Vocals have a quality known as timbre. I was taught in music theory classes that this is more or less the “texture” of the sound. Female timbre is softer and smoother than a male voice. A male voice has a rougher, more masculine timber. |
why do people code desktop apps in java when very few end users like it? | If you write in Java, your program will run on any system that is capable of running Java, which is basically every computer. Java certainly has its many flaws, but the ability to write a program that is guaranteed to be able to be run on anything is reason enough to overlook the flaws in many cases. |
why does "hard resetting" seem to fix just about anything like phones or gaming consoles? | All computers have memory. When they start up they copy the instructions they need to run into memory. If something goes wrong, the instructions in memory can break. Computers don't work when following broken instructions. When you turn off the computer, it removes all the instructions from memory. When it turns back o... |
how do erasable pens work? and why is the ink usually lighter than conventional ball and gel pens? | The ink is actually temperature sensitive, when it gets heated up, it becomes white, so when you erase, the friction from the eraser heats the paper and it becomes white
This is also why it looks lighter, because it has to turn white
Interestingly enough, if you put it in the freezer the ink that has been erased wil... |
how can we not feel any of our inner organs? or better why do we only feel pain and no other feeling with them? | Because you don't really need to.
Actually, you can kinda feel your organs. You can have sensations of pressure or distension in your stomach and bowels. If you take a deep enough breath, you can feel some shifting of your internal organs, or viscera.
But you're right that, for the most part, proprioception of your ... |
Considering the enormous number of memories we retain into old age, what was all of that brain matter being used for before these memories were stored? | Memory is a huge and complex topic which is not well understood. There are different kinds of memory, but you seem to be asking about [long-term explicit memory](_URL_2_).
Speaking mostly from the realm of artificial neural networks, which are only loosely modeled on brain physiology, I think the most concise answer ... |
Could a planetary system be close enough to a nebula so as to have "nebula-lit night sky?" | The most dramatic nebula images you generally see are those of [molecular clouds](_URL_0_). These are star forming regions, which will form stars and planets. However, much of the gas is dissipated within 10s of millions of years by the radiation and winds from big bright short-lived stars, which is barely enough time ... |
When an electrical flow is traveling down a metal wire, what is going on at the atomic level? | Electrical current is the "pushing" of electrons on each other. You can think of it as electrons being pulled from one atom, jumping to the next, and being replaced by those in line behind them to create a cycle. This is why electrical current only flows in a *circuit*, or a complete loop for the electrons to circulate... |
Was "boiling oil" ever regularly used in siege warfare, or is this a myth, or something that only happened a few times? | From the point of view of European medieval siege warfare, there are instances of a whole host of things being thrown by defenders over walls, through machicolations and down murder holes, or via siege engines by attackers. These include everything from rocks and pitch, to waste and effluent, to human corpses and anima... |
how are the children of illegal immigrants in the us (who, therefore, are also illegal) able to attend high schools and universities? | Public schools generally only require that you list your place of residence and you arrange for transportation, whether by school bus route or personally picking up or dropping off. Most school districts don't check citizenship because it's never been an issue.
Colleges just don't care about citizenship. They only loo... |
Did any of Leonardo Da Vinci's research actually lead to technological advancement, or was it all lost until it became irrelevant? | I actually wrote a paper on this last year, which allows me the delicious pretentiousness of quoting myself.
**TL;DR:** His rediscovered papers helped design a surgical robot in the late 1990s, and improved a specific type of heart surgery in the early 2000s. (**Edit:** And, as others have pointed out, not much else.)... |
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