id stringlengths 5 6 | input stringlengths 3 301 | output list | meta null |
|---|---|---|---|
10g9uf | how does a random function work? | [
{
"answer": "Before a matematician/IT guys confirms it, I can say that it takes a really difficult to foresee value (ex. the actual date, up to the hundredth of second) and feed its to a very complex function whose output is even harder to foresee, and has an uniform distribution in a given interval.\n\nEx. get... | null |
cj0otb | why can some brands completely rip off other brands designs on certain products? | [
{
"answer": "Per a quick google search, they are often lawsuits for this. However, I’d hazard a guess that court costs and lawyer fees are factored in before moving forward. Generic copy at Walmart maybe only profits 40k$, but the lawsuit would cost 200k for both sides. It’s now a loss to sue and not worth movi... | null |
dkh7xr | does convolution of signals have an intuitive explanation like the water-flow example for voltage and current? | [
{
"answer": "Have you heard of convolution reverb?\n\nBasically, you take an impulse response from, say, a cathedral, and then you can convolve it with any sound signal to make it sound as if it were in the cathedral.\n\nSo i guess a convolution is kind of like an echo. A bit like sonar - when there is somethin... | null |
89pr9h | the definition of “literary theory” | [
{
"answer": "I suppose there isnt one definition but a literary theory woukd be a way in which yoi can understand/interpret literature. \nFor example you could read a text in a feminist or post colonial way and theyre both literary theories. \nOr you could theorise on what literature itself is, for example lite... | null |
26k5hi | Mistakes Germany made on Russia | [
{
"answer": "There are two problems, I think, with the German War in the east. 1) the Germans, due to the racist Nazi ideology, was far too brutal against the Slavic nationalities in the conquered territories. 2) The size and scale of Russia made a rapid victory like in 1940 virtually impossible. \n\nTo point 1... | null |
15fv5d | Paper vs Electronics | [
{
"answer": "To add to that, how much difference is there between an e-ink e-reader and an actual book?",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "30182396",
"title": "Timeline of United States inventions (1946–1991)",
"section": "S... | null |
99cibf | How come Denmark ruled the Kalmar Union during 14-16 centuries, while Sweden was humongous in territory and Norway was considerably larger as well? | [
{
"answer": "Well, first let's sort out what the Kalmar Union _was_ (and wasn't). \n\nIt was a personal union, where three different countries had the same monarch. All three Scandinavian countries had elective monarchies at that time, albeit with a preference for electing people within he same dynasties. So th... | null |
ar49ob | how do we know what prehistoric life was like? | [
{
"answer": "We have a good understanding of biomechanics, how the shape of bones, their growth and wear patterns, how ligaments were attached, and a lot of the details that tell us how the moved, how they ate and hunted. Teeth can tell you a lot about what sort of food an animal ate. The design of the head ... | null |
53uetz | What was the fire rate of the matchlock musket, and how did it compare to wheel locks and flintlocks? | [
{
"answer": "16th century sources do indeed tend to be pretty unclear when it comes to firearm's rate of fire. Humfrey Barwick was a strong proponent of firearms at the end of the century and as such is probably represents the upper end of what might be expected in terms of fire rate. While serving as a mercena... | null |
cxhe0k | what's a good source of hydration during a hurricane if water supply in stores is sold out? | [
{
"answer": "The point is to stock up beforehand. Water comes out of your faucet for hundreds of times cheaper than in the store.",
"provenance": null
},
{
"answer": "Top part of the toilet. Seems gross but it’s actually clean except for a few airborne poo particles that sneak under the lid. No mor... | null |
1lvtc4 | why does canceling a credit card with a zero balance hurt my credit score | [
{
"answer": "Assuming you have other credit and you have outstanding balances. Canceling increases your credit utilization %..\n\nLets say you have two cards and one has a balance\nA:$50/$100\nB: $0/$100\nYou are using 25% of your available credit.\n\nYou cancel card B\n\nYour are now using 50% of your availabl... | null |
1w6l9w | Do computer screens have a direct effect on our levels of melatonin? | [
{
"answer": "Source:\n_URL_0_\n\nBasically yes, but only very slightly. Computer screens do suppress Melatonin levels.",
"provenance": null
},
{
"answer": "Here are a few papers I found that might help this discussion:\n\n \n1. Kubota T, Uchiyama M, Suzuki H, Shibui K, Kim K, et al. (2002). [\"Effec... | null |
22tnmq | why do indian reservations have such high unemployment? | [
{
"answer": "Very true and in case you have forgotten, the reservations were the tracts of mostly worthless land nobody wanted, far from civilisation. That should explain the dismal prospects ofvthe denizens.",
"provenance": null
},
{
"answer": "First Reason: No jobs... \nSecond Reason: Remote... \n... | null |
asxdxy | how do motor boat engines not get water logged? | [
{
"answer": "Same reason your car motor doesn't get water logged when you drive in rain or puddles.\n\nThe motor is not in the water. It's spins a shaft which is also attached to a propeller, that goes into the water. ",
"provenance": null
},
{
"answer": "The actual motor is well above the waterline... | null |
8b3pec | Are there any good book (for layman) about climate changes and their impact on the course of human history/prehistory? Hopefully with maps. | [
{
"answer": "Although comprehensive only in the sense that it attempts to cover the whole globe across most of the seventeenth century, with special focus on the impact of the Little Ice Age and associated abnormal El Nino episodes, Geoffrey Parker's book *The Global Crisis* (2013) is a major contribution by a... | null |
4gq882 | reverse entropy | [
{
"answer": "imagine you have a jar of marbles that you tip over. The marbles all go out in different directions, ricochet off of eachother, and settle. Now, you must put them back how they were before. How? That's impossible, that's so much data to somehow learn, which way each marble went and what it hit and ... | null |
6zgvsl | how do companies like walmart profit from selling gift cards to other services when a gift card costs the amount of credit it's worth? | [
{
"answer": "it is a strategy used to get people in the door, much like a sale, it is ok to not make as much money on one or two items because usually when people come in they buy more than they were intending to in the first place, it happens. so to get people in the door it is actually more profitable to sell... | null |
1fktav | Why are owls associated with intelligence? | [
{
"answer": "To answer the former question: Athena was the protector of Athens. Athena had an owl because owls were abundant in Athens. There's a proverb that says \"bring owls to Athens\" for a pointless venture.\n\n\nedit: I was answering the question of why owls are associated with the Greek goddess Athena."... | null |
42j6i5 | sound effects | [
{
"answer": "Yes, sometimes they just go out to a shooting range or go out driving with a bunch of sound equipment.\n\nUsually for movies they just buy the sound effects from someone who already did that and is selling all the sound effects.\n\nEither way, studios end up with libraries of sound effects they use... | null |
195zt7 | How important are cyanobacteria to *keeping* the earth's atmosphere oxygenated? | [
{
"answer": "Indeed, they are very important. [Here](_URL_0_) is a Nat. Geo. article on this very topic (though they are talking about all phytoplankton, but just cyanobacteria). It's a bit old (2004), but still agrees with several other more recent sources I found. The short answer is that, yes, photosynthe... | null |
1wpgez | is it true that if you eat human flesh your body will uncontrollably shake? if so, why? | [
{
"answer": "It could happen, yes. It's due to a prion disease called Kuru: _URL_0_",
"provenance": null
},
{
"answer": "Not quite.\n\nTremors from cannabalism is a result of 'Transmissible spongiform encephalopathy', and it results from eating brain tissue that contain certain prions (a kind of def... | null |
3rk4cs | how is the sugar coating on sour candy so much different than table sugar? | [
{
"answer": "From Wikipedia: *Sour sanding, or sour sugar, is a food ingredient that is used to impart a sour flavor, made from citric or tartaric acid and sugar. It is used to coat sour candies like Sour Patch Kids or to make hard candies tart, such as acid drops or SweeTarts.* It's not quite the same thing. "... | null |
1ivxvy | how are airplanes able to travel through the air despite being heavier than air? also, what exactly is jet propulsion? | [
{
"answer": "Airplanes fly by generating lift. Their wings are shaped in such a way that when they are moving through the air, the air passing over the top of the wing is moving faster than the air moving under the wing. The faster that air moves, the lower pressure it has. Since the faster moving air on top of... | null |
483ggs | when you forget something, why does retracing your steps often make you remember? (such as going back to a webpage you closed or redoing the activity you were doing) | [
{
"answer": "For me, it tends to be that something in what I was doing was the impetus for the thought to begin with. When that stimulus occurs again, the thought happens again in the same way it did initially.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia... | null |
a8a86r | Is radioactive decay temperature-dependent? | [
{
"answer": "Typically is not, the nucleus is so much smaller than the atom that it doesn't \"care\" what's happening around it (imagine a marble at the center of one of those giant human hamster balls). There are maybe a few small exceptions. \n\nOne could argue that the electron-capture mechanism (sometimes c... | null |
1w89u3 | batteries: rechargeable vs disposable | [
{
"answer": "Rechargable batteries have different chemistry from disposable batteries. And the different chemistries result in various pros and cons.\n\nA NiMH AA has a voltage of 1.2, but an alkaline AA is 1.5. But most electronics tolerate these small differences.\n\n\nA more significant difference for a us... | null |
2kortk | why was microsoft criticised for bundling a browser and media player with their os, but is apple allowed to bundle a computer with their os? | [
{
"answer": "Microsoft was leveraging its monopoly to put a much smaller rival out of business.",
"provenance": null
},
{
"answer": "The difference is that Windows is very widely used for more than normal computing, servers and other uses are common. Not to mention that you can install windows on ba... | null |
20aw9h | why do some nutrition labels read "total carbohydrates 30g" but sugars will say "sugars 22g"? | [
{
"answer": "Sugars are a simple type of carbohydrate. \n\nFibre (cellulose) is technically a carbohydrate, but it is not digestible and has no direct nutritional value. It is therefore not included in the total carbohydrates of food.",
"provenance": null
},
{
"answer": null,
"provenance": [
... | null |
fuevro | what do the schrödinger and dirac equations describe and what's the difference? | [
{
"answer": "The Schrödinger equation (ih d/dt psi = H psi) is a very general statement about quantum mechanics: the phase of a state changes (it ”turns”, in a way) proportional to its energy. It can describe many different things as long as you use the correct H. Note that I’m NOT talking about the common form... | null |
8hiidl | English (Latin?) certainly made its view of left-handed people clear (sinister - left handed) but are there any cultures were left-handedness is seen as better than right-handedness? | [
{
"answer": "You might try /r/Askanthropology. There may be someone here with the answer, but this other sub has a concentration of people with a background in comparative ethnography.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "172644",
"ti... | null |
kaocu | obama's new jobs bill. | [
{
"answer": "good one! I can't wait for an answer.",
"provenance": null
},
{
"answer": "You can read about it [Right Here](_URL_0_) from a previous ELI5. Cheers.",
"provenance": null
},
{
"answer": "good one! I can't wait for an answer.",
"provenance": null
},
{
"answer": "Yo... | null |
356fh1 | what makes the noise in an engine? | [
{
"answer": "Its either the engine lifter's noise, valve noise, the combustion, bearing noise, or the exhaust of the car itself you're talking about at the moment.\n\n\nVroom vroom.",
"provenance": null
},
{
"answer": "A short answer: the explosions cause by the sparks within the pistons (or cylinde... | null |
26z988 | what is al qaeda fighting for? | [
{
"answer": "Islamic caliphate - A worldwide dominance of Islam and governance according to sharia.",
"provenance": null
},
{
"answer": "[Here is a letter from Osama Bin Laden to America](_URL_0_) The basis of this is that we are supporting acts of aggression against Muslims via Israel, occupying th... | null |
4gzeho | why does styrofoam melt when it comes into contact with superglue/adhesives? | [
{
"answer": "Super glue and other adhesives contain some organic solvents (e.g. acetone, ethyl acetate). Styrofoam is made from thousands of styrene molecules linked together. Styrene by itself really wants to dissolve in these organic solvents, but since so many of them are linked together it can't because it'... | null |
1y9sro | how do services like pandora and spotify work | [
{
"answer": "same way any business operates. sell it for more than you buy it.\n\nif it costs $10,000 for Pandora to buy the rights for a song, and they play it on 1million users and get advertising $0.01 per play, then that's profit.",
"provenance": null
},
{
"answer": null,
"provenance": [
... | null |
21c9ta | putting down animals in zoo | [
{
"answer": "Did you read the rest of the article? They explained exactly why they did it.\n\nThey didn't have the money to relocate the animals, and the new animals they were getting would have killed the old animals -- euthanasia makes a little more sense than a zoo snuff show.\n\nIt's more important to look ... | null |
a2ai3x | why is it easier to fall asleep to background noise (radio, tv etc.) than just the plain dark? | [
{
"answer": "In my experience, a little background noise (white noise) helps cut out any outside noise that might wake you up ",
"provenance": null
},
{
"answer": "This happens because when there's noise around us we feel that someone is near us.\nThus we feel safe and can let go of the tension and ... | null |
c1abiu | how are amputees able to control the fingers in their bionic arm ? | [
{
"answer": "Conventional myoelectric prostheses, what 99% of the bionic hands on the market use, are controlled by two inputs. Two sensors on the forearm (in the case of a below elbow amputee) pick up muscle signals. The amputee can either open or close the hand. Programming in the hand and using a variety of ... | null |
fsidc | I have a weird question about micro-gravity. | [
{
"answer": "I'll attempt to answer part of this question seriously. I wouldn't know anything about the first two questions, but in terms of the third question you may be interested in [this nice Slate piece](_URL_1_) which has quite a bit of information.\n\nIn addition, you have several problems with radiatio... | null |
3srgnb | why haven't we seen the us (and its partners in the fight against isis) engage in a siege of raqqah, the "de facto capital of isis"? | [
{
"answer": "Isis doesn't wear uniforms, man. They blend in with civilians, that is their defence tactic. Raqqah has a population of like 300k, how many more innocents need to die ?",
"provenance": null
},
{
"answer": "1. Raqqa is surrounded by other territories controlled by Islamic State, so to ... | null |
1lsovb | Was there any ethnic tension between Germans, Slovaks, Slavs, etc... in the early 1900's and leading into the second World War? If so, what was it like? | [
{
"answer": "Of course there was. In the early days of Czechoslovakia, tensions between Czechs and Germans were a major issue that would later play a part in the months preceding the Second World War and the occupation of Czechoslovakia, and that would only be resolved until after the war. And even then only vi... | null |
7m4e2p | when did the storefront name of "arcade" go from being a kids' video-game hangout, to being an 18+ slot machine parlour? | [
{
"answer": "It happened due to home gaming consoles.\n\nOlder redditor here. I used to play the quarter-munchers back in the days before everyone with teens or kids had at least a couple game consoles... and the earlier generations were really shitty. So you'd go to the \"pinball arcade\" to play games with mu... | null |
308jls | what is the difference between readings books (any kind) and reading various reddit articles/threads? | [
{
"answer": "Reddit posts & articles are usually fairly short. There's not a lot of depth or nuance going on - especially the front page, which is full of image, memes and other such easily digestible things (not to mention all the articles that get commented on by people who never read the link).\n\nA book,... | null |
9v7eea | Was Cato the Younger a Pleb or patrician? | [
{
"answer": " > When Clodious , who was from a minor patrician family\n\n*Minor*?! The *gens Claudia* was one of the largest and most prestigious patrician *gentes*, outstripped only in surviving patrician lines by perhaps the *gens Cornelia*. To call Clodius a member of a minor family is like calling the sun a... | null |
1352eq | Why did the Irish Rebellion in 1798 fail? | [
{
"answer": "In short (don't have much time, so perhaps someone can expand on this)\n\n1. Three of the United Irishmen's top brass were arrested on the eve of the uprising.\n\n2. Artillery stationed in Ireland had been upgraded and increased in size. One Lieutenant was to describe that the 'Grapeshot (cannister... | null |
b5s4wd | why can paying off your student loans hurt your credit score? it seems like it would be a good thing. | [
{
"answer": "Part of a credit score is being able to prove you can pay off debt, which requires having debt to begin with. That’s why people who have never had a credit card or loan generally don’t have good credit. Without any debt, you can’t prove you have the ability to pay it off, hence the lower score.\n\n... | null |
cbefmn | What was the primary warship of the Indian Ocean before the advent of the modern period? | [
{
"answer": "One particular aspect of maritime situation in the Indian ocean in the second half of fifteenth century which is often emphasized by scholars, is the *relative* peacefulness and *absence* of large scale naval conflicts. The accent here is really on the word *relative* as piracy was abundant and the... | null |
2ppwgh | when i'm tired, every now and then i will go through bouts of extreme drowsiness where i can't even keep my head up and eyes open, but after about 5-10 minutes i am awake again and completely fine. what are these cycles and how do they work? | [
{
"answer": "Could be a bunch of things, but generally that's not normal. Could be blood sugar or blood pressure drops, narcolepsy, etc... Should see a doctor.\n\nIn my case, this would go on for an hour or two every couple days. I had a 3x2 inch tumor (what they call a \"schwannoma\", noncancerous) in my neck ... | null |
2olx19 | suitjacket, sportcoat, and blazer? which situation calls for which jacket? | [
{
"answer": "Sport coats have patterns, unlike blazers, which are solid and have contrasting buttons. Suit jackets are smooth, have tonal buttons, and should never be worn with anything other than matching suit trousers.\n\n",
"provenance": null
},
{
"answer": "Generally, suit for formal occasions, ... | null |
3yvmjh | why are so many large companies headquartered in minneapolis? | [
{
"answer": "Minneapolis has a well educated population, the standard amenities of a major city, is a hub for a major airlines, has a high livability index, and still maintains a relatively low cost of living compared to other major cities.",
"provenance": null
},
{
"answer": null,
"provenance":... | null |
a88scv | why are b.c. (before christ) and a.c. (after christ) the reference points we have chosen to use for historical measure, as opposed to any other major historical event? | [
{
"answer": "Nowadays you often see “BCE” which stands for “Before the Common Era.” “BC/AC” was just a handy reference since many Western historians were/ are Christian. ",
"provenance": null
},
{
"answer": "In the rest of the non-Christian world other systems are used. In fact entirely different c... | null |
7h4fr1 | if most psychopaths become psychopathic due to their childhood or a birth defect, why are most psychopaths male? | [
{
"answer": "Because contrary to what you might have been told, gender is not actually a social construct. Our brains are wired differently, and when they malfunction, they malfunction in different ways. Just like women are much more likely to suffer from unipolar depression, men are more likely to become psych... | null |
7o96qt | What problems was fascism intended to solve? | [
{
"answer": "Hi there. There's always room for more discussion (and follow-up questions) but you might be interested in [this older answer of mine](_URL_0_) about the prelude to Mussolini's rise. [This great answer](_URL_1_) by u/Klesk_vs_Xaero is also great overview of Italy's descent into dictatorship\n",
... | null |
4ca43l | Why is it that the inside of fresh water pipes that feed houses don't need regular cleaning? | [
{
"answer": "They need. If you use a pipe system for 20+ years there is gonna be a lot of build up. Most of the time its not necessery bad.\nThe thing is nobody thinks about it. \n\nIn germany the situation is as the following: the main pipes up until to the house are the responsibility of the city.\nEverything... | null |
a9k4bp | what makes our ears ‘clog’ in high altitudes and what makes them pop by yawning? | [
{
"answer": "Im pretty sure when there’s low air pressure it messes around with how your inner ear functions and yawning sorta stretches it making it “pop”.",
"provenance": null
},
{
"answer": "Air in your middle ear is at a higher pressure than the surrounding air; popping is allowing that air to e... | null |
3ca9h5 | Imagine an empty room with no windows/doors or any point of entry and escape with just a light bulb inside and a light switch outside. What will happen to light if I open the light for 10 seconds and turn the switch off? Will the brightness remains or will fade? Why? | [
{
"answer": "The light will fade almost instantly. As the light strikes the wall, part of it is reflected and part of it is absorbed. The reflected light will bounce away from the wall until it hits another wall (or floor/ceiling) and then again, part of it is absorbed and part reflected. With every bounce the ... | null |
8y3rcf | why are surgical gowns, masks, and gloves green or blue? | [
{
"answer": "They used to be white. There's a sort of 'surgeon legend' about the green being used because it was easier to see in a surgical field (brightly lit + whites = too bright). But then also that green/blue is actually opposite red and makes it easier to see blood. But I think it's kind of one of those ... | null |
32eegb | In medieval times, how long could a knight physically fight in a battle? The swords were heavy, the armor was heavy. Nutrition was poor. Could they last more than 30 minutes? | [
{
"answer": "This doesn't directly answer the question, but I think you may be overestimating the weight carried/worn by a knight.\n\nThe average sword weighed somewhere around 3lbs, an M16 with full ammo weighs about 9lbs.\n\nA suit of full-plate would generally weigh less than 60lbs (sometimes significantly l... | null |
5ol96w | If I were to travel ten light years going the speed of light, would it seem like an instant to me, but ten years for an outside observer? | [
{
"answer": "You *cannot* travel *at* the speed of light, so this question becomes pseudo-scientific.\n\nBut let's say you were travelling *really* close to the speed of light. Like *really, really* close. Like 99.999...999% with a billion, billion 9s after the decimal place. Then yes, what you say is correct. ... | null |
7mgcxp | How does pilot wave theory account for quantum fluctuations? | [
{
"answer": "The guided particle doesn't move through space, it moves through the space of possible positions of all particles, which instead of just 3 dimensions has 3N dimensions, where N is the number of particles. The positions of particles in a measurement device is included in this, so the question of wha... | null |
bud7iq | AskScience AMA Series: I am Jamil Zaki, professor of psychology at Stanford University and director of the Stanford Social Neuroscience Lab. I wrote a book called The War for Kindness, which shares stories and research about how to fight for empathy even when it feels impossible to some days. AMA! | [
{
"answer": "Excited to read your book! I work in early years education in conflict/post-conflict zones and am constantly looking for ways to include empathy-building in the classroom.\n\nWhat do you think it will take for educational policy to reflect the need for empathy in our curricula?",
"provenance": ... | null |
19thn7 | Does Anybody have any information on the "Phantom Divisions" of the United States Army during World War II? (Cross Posted From r/Military) | [
{
"answer": "Could they be similar in role to the [Ghost Army](_URL_0_)?",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "5591046",
"title": "List of formations of the United States Army during World War II",
"section": "",
"start... | null |
6qrwya | why does it seem easier to get stuck in a comfort zone as an adult? | [
{
"answer": "In the old days, life changed very slowly. The way the world worked when you were 5 years old was the same when you were 75 years old. So by the time you had reached adulthood you pretty much had figured out what there was to figure out.",
"provenance": null
},
{
"answer": null,
"pr... | null |
12ztqx | Constellations disappearing: | [
{
"answer": "Stars rarely just go missing, but the constellations will change over time due to stars moving at different velocities. Here's [what some of them will look like in 50,000 years](_URL_0_).",
"provenance": null
},
{
"answer": "If it's a particularly bright or hazy night, sometimes the fai... | null |
a0s2ct | Why did Britian use the bolt action Lee-Enfield as their primary battle rifle when repeating technology (M1 Garand, Gewehr 41, etc) was already developed and working? | [
{
"answer": "hey, sorry for the very late answer, i hope i don't break any rules by digging up old unanswered questions.\n\nTo answer this question you have to understand how the adoption of a self loading rifle would have worked in britain in the 1930's. \n\nTo get a new rifle adopted, someone in the board ord... | null |
nvxvz | conservation of mass says matter can't be created nor destroyed. do we have any theory of how this fundamental law was originally ignored to create the big bang? | [
{
"answer": "The original question not entirely accurate. Mass/energy (they are the same thing) cannot be created or destroyed, but mass *can* be turned into energy, and vice versa. \n\nNuclear reactions attain their vast energy outputs by converting a small (but non-trivial) amount of mass into energy. Even ch... | null |
el8qip | The Norse people were shown to be capable raiders, especially in the British Isles. The Anglo-Saxons despite divided were socially and militarily organised, why did they, or others, never seek or attempt to attack Scandinavia? | [
{
"answer": "I afraid that I cannot offer a single definitive answer to 'why X didn't Y' type question of OP. Instead I'll make some corrections to OP's premise below. \n\nFirst of all, there was no known unified large-scale kingdom in Scandinavia before the middle of the 10th century (until the rise of the Jel... | null |
1f7823 | What happened to Dutch painting in the 18th century? | [
{
"answer": "Apparently during the 18th century the Dutch Republic was seen as being in a decline. Instead of commissioning new works by comtemporary artists, patrons preferred to obtain works from the Golden Age, when their country was more stable and prosperous. And in 1718, Dutch artist Arnold Houbraken pu... | null |
5m4mzf | how does an led change colors? | [
{
"answer": "A color changing LED isn't one LED in a package but three LEDs along with a small computer to drive them. The LED is made up of red, green and blue LEDs each of which can be controlled by a microcontroller. Since the two legs on the LED that supply the power are connected to the microcontroller and... | null |
1k5iqn | How will it affect US economy if bill gates were to transfer all his money to some other country ? | [
{
"answer": "The exact disposition of Bill Gates' personal wealth isn't information we can get our hands on, since he's a private citizen and it's none of our business. So instead let's make up a person with the same order of magnitude of wealth, imagine how he would store his wealth, and then answer the questi... | null |
awghnc | Is there a way to conceptualise complex integration? | [
{
"answer": "In complex analysis, an integral is less like the \"Finding the area under a graph\" integral of calc 1, and more like the line integrals of vector fields in calc 3. These path independence results are actually there in normal multi-variable calculus. In this context, integrating a differentiable c... | null |
3impk0 | cannabis strains classification. | [
{
"answer": "It's both. There's a classification system to differentiate between plants, and from the same family of plants.\nAnd with cannabis, naming the strains means that you can get the same product again without confusion; but you can name any strain the name you want. There's no science behind that.",
... | null |
3bpxp5 | Why are siphonophorae considered "colony organisms"? What's the difference between a morphologically specialized zooid and an organ? | [
{
"answer": "the distinction is made based on the origin of the zooids\n\nin everything from a fruit fly to a human the first fertilized cell divides many times into a mass of cells, aligns itsself along some gradient and develops bands of cells with know fates \n\nsiphonophore cells bud off the first fertilize... | null |
1v19bw | Historians, how many of you speak/ have fluency in languages relevant to your areas of study? How important would knowledge of such relevant languages be to you? | [
{
"answer": "Before I refocused myself into Early Modern France, I was aiming to be a Classicist with a focus in the Late Roman Republic, so I had to learn Latin and Ancient Greek, the latter of which is still useful in my current focus on Early Modern France since the Habsburgs wrote laws in Latin first.\n\nI ... | null |
4uxjwq | why airlines don't sell empty seats on flights at cheap rates | [
{
"answer": "Because people who purchase tickets last minute usually *have* to travel and will pay the full price.\n\nIt's rare that a plane will be relatively empty. When that happens, it's probably just a fluke. If a route regularly has a lot of empty seats, they airlines will drop one of the flights and put ... | null |
1c07io | Part 1: What causes a person with Tourette's to shout obscenities? Part 2: What would happen if they never learned any curse words? | [
{
"answer": "I would just like to point out that not all verbal tics are curse words— [here is an article about a woman with Tourette's Syndrome who involuntarily says the word \"biscuit\" ~900 times an hour.](_URL_0_) The article also mentions that\n\n > \"Fewer than 10 percent of all patients [with Tourette's... | null |
ekuabf | why can't we use the ocean to dump onto fires? | [
{
"answer": "So... What about an intercontinental seawater highway? Or a water version of the electric grid? Could we, over time, create a set of pipes (an interconnected series of tubes perhaps? ;-) ), that carry sea water across the nation? Desalinization is still a problem, but it sounds like transporting t... | null |
2tt0j9 | Tuesday Trivia | Missing and Destroyed Documents | [
{
"answer": "I wouldn't say it's destroyed (yet), but a lot of Phil Weigand's data is unpublished. Things like aerial photography from before agriculture became more intensive. Locations of looted shaft tombs and guachimontones. Profile drawings of looters pits in structures and tombs. Samples of ceramics from ... | null |
319yt6 | To what extent was the Japanese government aware of the Manhattan project or similar nuclear weapons project prior to the deployment of the nuclear bombs during WWII? Was there any awareness that such a thing was possible? | [
{
"answer": "Practically all physicists knew that atomic bombs were theoretically possible after the discovery of nuclear fission and the nuclear chain reaction in the early months of 1939. Most thought that they were a technology that was not going to emerge for another decade or so, and if they were intereste... | null |
mrfm6 | What causes absorption of right- or left- circularly polarized light by chiral molecules? | [
{
"answer": "The difference between molecules of left and right chirality is exactly the same as the difference between left and right circularly polarized light- a mirror symmetry.\n\nThe reason that a non-chiral molecule cannot reflect the two polarizations differently is because that molecule has a mirror sy... | null |
a9a2rj | [META] Merry (UTC) Christmas and Happy Holidays to AskHistorians! As an extra-special gift from the Asia flairs, we've completely revamped our book recommendation list! Links below! | [
{
"answer": "Now we get to the comments thanking the contributors to the list. Firstly, I’d like to give special thanks to three flairs whose contributions are not (at present) immediately apparent on the list itself.\n\n* Firstly I’d like to thank fellow Asia flairs /u/keyilan [Moderator | Historical Linguisti... | null |
2yesv7 | does piracy actually hurt the profit of corporations? | [
{
"answer": "If any brainy person with data can answer this well, I hope they also take into consideration the affect of franchise knock-on, which is often not discussed. And arguably makes up a larger long term profit and vertical integration, or market synergy and all that.\n\n\n\n\nFor example people who may... | null |
44tvzf | Why does male pattern baldness follow the pattern it does? i.e. from the top of the head down, often in a perfectly straight circle around the head. | [
{
"answer": "It doesn't. Sometimes the hair line recedes all the way to the back of the head, sometimes a bald spot appears on top of the head and increases in diameter over time. \n\nSometimes there is even a patch at the front that is missed leaving a little island of hair. \n\n\n_URL_0_",
"provenance": n... | null |
7pxblx | how did some neighborhoods in america came to be known as 'black neighborhoods'? is it mainly because of segregation? | [
{
"answer": "Housing segregation enforced by redlining and blockbusting and white flight. \n\nSo, you take a neighborhood, and you line it. Red lines are where black people are able to live. Banks would (and still do) deny black people loans to live outside of the red lines, and designate the loans inside of th... | null |
xji30 | why were african, australian and native american civilisations so technologically inferior compared to european and east asian civilisations? | [
{
"answer": "There are two main explanations. The first is that these places were much more isolated. Traders didn't come over as often (or ever), and so any technological advancements didn't get shared like they did in Europe. So they had to invent everything themselves, while Europeans could steal liberally f... | null |
t3k4u | When I donate blood, I sometimes wonder: What happens if the blood recipient is allergic to something I recently ate? | [
{
"answer": "Food allergies typically act on tissues the food encounters before digestion, such as the oral and esophageal mucosa, resulting in swelling or rashes of the throat leading to constricted airways. Once the food enters the stomach the allergens are broken down before entering the bloodstream, so bloo... | null |
1x9p9x | what exactly does this mean (pic in post)? | [
{
"answer": "In some locations, failing to upkeep a property means it can be forfeited to a new owner who does want to care for the property. The sign was posted by essentially squatters who want to prove no one cares for the property. \n\nIts called adverse posession. ",
"provenance": null
},
{
"a... | null |
2d8v8u | why does my cat insist on having me constantly feed him, even though he still has food in the bowl? | [
{
"answer": "Cats are assholes?",
"provenance": null
},
{
"answer": "My cat literally meows for me to watch him eat. I'll be in my room and will hear him meowing from downstairs so I'll go down thinking he wants me to let him outside. When I get downstairs he leads me to his food bowl and just eat... | null |
3c3uk0 | swingset physics | [
{
"answer": "In the absence of friction (or other energy sinks), a swingset, or indeed any simple pendulum, would simply continue to oscillate indefinitely between the two high points. At one extreme, when the pendulum is highest and its speed zero, the system has maximum gravitational potential energy, and zer... | null |
3apep9 | Which planet, if it disappeared, would affect Earth the most? | [
{
"answer": "If Jupiter were to magically disappear I expect we'd quickly be exterminated by an asteroid impact. \n\nThe solar system is, to first order, the sun. Pretty much everything that goes on can be pretty thoroughly described if you just know the distance to the sun, its mass, no matter where you are in... | null |
2h4ar2 | how do we know that we 'mixed' with other human species? | [
{
"answer": "Scientists are able to analyze DNA and determine your ancestors. Certain areas/species have specific genes, and we have recently discovered Ozzy Osborn has traces of Neanderthal heritage: _URL_0_\n\nThat's how we \"know\". But evolution occurs at such a slow rate, so it's not like two subspecies of... | null |
2isdqh | If one clock orbits Earth moving very fast, why does it measure less time when, relative to the orbiting clock, Earth-bound clocks are moving equally fast? | [
{
"answer": "See the [Wikipedia article for twin paradox](_URL_0_), specifically the resolution part.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "27616141",
"title": "Error analysis for the Global Positioning System",
"section": "Sec... | null |
65s86q | During the Holocaust what was the difference between the death camps and the work camps? Also how was it decided who went where? | [
{
"answer": "_URL_0_\n\nu/commiespaceinvader answered a lot of my questions in this post, but I'm still unsure of how it was decided who went to what camp",
"provenance": null
},
{
"answer": "Good question! I hope that you read the link given in another answer and that you found some answers there.... | null |
3ga74o | A friend of mine tells me every culture around the world has a myth of a great flood wiping out the whole world, and that the timelines match up indicated they are talking about the same flood. How true is this likely to be? | [
{
"answer": "[Mark Isaak has collection about a gazillion flood stories.](_URL_0_) That is a lot, but not every country has one. Nor is there all that much similarity across the stories. Boats are common, but you expect boats in a flood story. Some destroy the world and we go to a new one, some just destroy the... | null |
f916g4 | How can I learn history on my own and take steps to be a buff? | [
{
"answer": "That’s a pretty broad spectrum. Are there any events, eras, or regions that you find most interesting.\n\nThe sub has a series of book recommendations for all sorts of topics, broken down by subject matter. You should definitely take a look.",
"provenance": null
},
{
"answer": "I thin... | null |
1s9hx4 | Why were (or even how) the battle tactics of Mesoamerican peoples so different from those of the old world at the time of contact? | [
{
"answer": "The idea that the \"Aztecs were looking to gain captives in combat\" is really quite overblown. While the taking of prisoners was important for advancement in social and military rank, the number of prisoners to gain high status was quite small -- as few as 4 captives depending on the circumstances... | null |
48vw38 | why flight attendants close the windows during the night? | [
{
"answer": "So people can sleep. Night destination-time may not correspond to night at the longitude the plane is currently over. For example, you may be arriving in Europe early in the morning, but flying partially during daytime.",
"provenance": null
},
{
"answer": "When the sun comes up it gla... | null |
g2skw | Does metric expansion of the universe apply to the dimension of time? If not, why not? | [
{
"answer": "If you look at the equations:\n_URL_1_\n_URL_0_\n\nYou will see the scale factor does not apply to time. ",
"provenance": null
},
{
"answer": "It appears that space/time could be expanding, but from what point of view would one view this happening?",
"provenance": null
},
{
... | null |
4iat99 | why do most power plants convert heat into electricity by heating water into steam and then using it to spin a turbine? is there not a more efficient way to do it? | [
{
"answer": "None that we've found. There are ways to make the process more efficient, but nothing can reliably keep the turbines spinning at maximum capacity (their most efficient state) as consistently as steam.\n\nThough things like solar power may eventually overtake them.",
"provenance": null
},
{
... | null |
5xfnjw | what is the significance of having headphones in the correct ears when listening to music? | [
{
"answer": "There isn't one from a music perspective, (some songs have differences in the left-right channel, but it doesn't really matter if it is reversed). The problem is with the shape of the headphones themselves. The right headphone is shaped for the right ear, so if you put it in the left ear then it wi... | null |
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