id stringlengths 5 6 | input stringlengths 3 301 | output list | meta null |
|---|---|---|---|
5had37 | What did other periods in the history of the British isles think of stone henge? | [
{
"answer": "Some parts of your question were covered in [this earlier answer,](_URL_1_) which points out that the earliest certain written record of Stonehenge only dates from the late Norman period (c.1130). And even after that, it wasn't until the first stirrings of antiquarianism in the mid-17th century tha... | null |
3ojev3 | what the meaning is of the different "alarm" fires. for example, a major fire is known as a "5 alarm" | [
{
"answer": "It's a system to describe how many resources are being devoted to a fire. More alarms means more trucks and firefighters are responding.\n\n_URL_0_",
"provenance": null
},
{
"answer": "Each \"alarm\" is essentially a call for multiple additional units to a fire. These are done in fairly... | null |
xgxa9 | antibodies and antigens. | [
{
"answer": "Immunology is one of those topics that can get extremely tedious and complicated. So, since I don't know how much detail you're looking for exactly, I'll just start with the basics and you can ask questions from there if you like!\n\n* Antigen (\"against life\") = anything that is harmful to you an... | null |
biozb9 | In many medieval movies such as Braveheart there are often scenes with military commanders shouting motivational speeches to entire armies on the battlefield without using voice amplification of any sorts. In real life, were they really able to hold speeches like that and is this how it was done? | [
{
"answer": "The answers are further back in time than you're asking about here, but while you're waiting this thread might interest you:\n\n[*Do the speeches we often see before a battle in most literature and visual performances have any historical basis. Did the kings and generals leading an army ever give a... | null |
34ctvr | the concept of english "tea". | [
{
"answer": "The British in general and some other folk in the Commonwealth. My more elderly but still Canadian by birth family certainly has the same tea fixation even if they don't call anything in particular 'tea time' or 'afternoon tea'.\n\nTea is a common drink and there is a sort of 'tea time' some observ... | null |
6mau4s | what makes cloud black? | [
{
"answer": "Sunlight comes from above, and it can only go through so much moisture before it's all blocked. Therefore the gray areas are just the thickest areas of cloud coverage. The clouds themselves are actually white throughout, just varying levels of sunlight.",
"provenance": null
},
{
"answer... | null |
zliuz | What's a piece of knowledge from your area of historical study that you enjoy telling people about, and why? | [
{
"answer": "'Pirates' helped finance the first Episcopal church in Rhode Island, Trinity church. The church denies this (and are technically correct), as none of the men were ever convicted of piracy, or they were under a Letter of Marque at the time (making them privateers).\n\nThis little factoid allows me t... | null |
1jbdzb | is cryogenic sleep possible? | [
{
"answer": "Not yet.\n\nWhen ice forms, it forms tiny crystals. These tiny crystals tend to pierce the cell walls of animal cells. As you can imagine, having all of your cell walls shredded is fatal.\n\nThere are a few exceptions. Some species of frog, by modulating the solute concentrations (amount of diss... | null |
8tmwja | Is our solar system considered normal? What other variations are there? Stars with rings? Stars as planets? Special orbits? | [
{
"answer": "Our detection methods don't work well for systems that look like our solar system. We don't know yet. What we know for sure: There are many systems that look completely different. Planets much closer to the star, much more distant, inner gas planets and outer rocky planets, planets in double star s... | null |
wj8r4 | we have so much water continually running-- streams, rivers, lakes-- where does it all come from and how? | [
{
"answer": "Well, you have this thing called watersheds. Watersheds are basically an area of land in which we can safely predict that a healthy amount of the water available in this land will flow into a specific body of water, like lakes or rivers. So although you don't see rainfall specifically landing in th... | null |
27fh4i | how are certain roads "aircraft patrolled" for speeding? | [
{
"answer": "This is one of those stupid things I think about every time I drive past one of those signs, and never think to research when I'm home. Next stop, Google. ",
"provenance": null
},
{
"answer": "There are lines painted on the side of the road. The planes will see your car cross a line an... | null |
3x7czk | how can a bunch of 0s and 1s create everything digital? | [
{
"answer": "The whole subject is a bit too complicated and a bit too deep for a short ELI5, but I'll give a stab at the gist of it.\n\nThe reason why computers work (at least in the vein of your question) is very similar to the reason why we have language -- written, spoken, etc. \n\nWhat you're reading right... | null |
devr00 | What was the reasoning for the Pancho Villa Expedition? How was Pancho Villa able to evade U.S. capture for so long despite the large force sent to stop him? | [
{
"answer": "Villa's motives for the Columbus raid seem to have been various. He wanted to take revenge on the American arms dealer who had taken money for supplies and neither given him the arms or returned the money. He was increasingly angry at the way the US professed to be neutral in the Revolution, but a... | null |
1bmkec | (In)Accuracies in Asbury's "The Gangs of New York"? | [
{
"answer": "I'm not going to answer your question directly, and I apologize since this will be a top level post, but I don't know that you will get any replies again. You're asking the people here to do your homework for you in a way. But I'll give you my thoughts as someone interested in the period.\n\n[*Th... | null |
4ryj4d | Is medieval French as incomprehensible to modern French speakers as Medieval English is to modern English speakers? | [
{
"answer": "If anyone can answer this, what's the case with the other major romance languages e.g. Spanish, Italian, etc? ",
"provenance": null
},
{
"answer": "Might be worth a cross post to /r/linguistics ?",
"provenance": null
},
{
"answer": "Hi! I hope this answer will help you out. ... | null |
5lyqdg | the 9 pieces of 8 in pirates of the caribbean | [
{
"answer": "Each of the nine Pirate Lords agreed to hold a piece of eight to be presented during a meeting of the Brethren Court, though the term came to apply to a variety of items and trinkets as the pirates found themselves short on money, simply keeping the original term as it sounded more 'piratey'. Each ... | null |
upx8o | Colonization of Venus | [
{
"answer": "As I recall, the theory was to use balloons of some sort to keep one aloft amongst the clouds. The big problem was corrosion, something that I have yet to read a solution for. I'm actually curious about what one would do for food, colonial expansion, the initial costs to doing this, and harvesting ... | null |
4ut8zr | Is atmospheric noise truly random? | [
{
"answer": "Atmospheric fluctuations are not truly random, they're just extremely chaotic and unpredictable.\n\nRadioactivity is different. As far as we can tell, it really is random when a radioactive particle will decay.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
... | null |
e4ipgf | how do scientific research articles get published? how do we know their results aren't faked? what exactly are scientific journals and how do researchers get revenue from publishing their research work? | [
{
"answer": "When an article gets submitted they have a lot of people look at it and similar data in order to publish it. It generally takes months. And a lot of research is funded either at a government or private level.",
"provenance": null
},
{
"answer": "The articles are submitted to journals or... | null |
hj8cg | What is the most inaccurate and accurate movie regarding your field of study? | [
{
"answer": "\"20,000 Leagues Under the Sea\"\n\n20,000 Leagues = 111,120 km\n\nDiameter of the Earth = 12,769 km",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "45051881",
"title": "The Big Short (film)",
"section": "Section::::Receptio... | null |
5oirzt | Why is facial hair such an important thing in the Abrahamic religions, and does it have importance in any Eastern religions? | [
{
"answer": "Hi, long-time lurker. But I think I can actually contribute a bit to this!\n\n___________________________________________________________________\n\n**Banned Beards**\n\nI actually don't know too much about the Jehovah's Witnesses, so I won't try and touch on their beliefs and practices.\n\nMormons... | null |
2dhm58 | Was there ever any movement to have the United States switch to driving on the left side of the road? | [
{
"answer": "Also, was/is there any movement to have the UK switch to driving on the right side of the road? I know that some countries have made a switch, so the UK possibly could too.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "301108",
"t... | null |
4m7uy3 | What could happen to East Germans whose family escaped to the West? | [
{
"answer": "It was illegal to leave the GDR without a special permit, which also stated how and when you had to return. If you failed to do so, you risked criminal prosecution according to § 213 StGB-DDR, up to 5 years in prison (extended to 8 years in 1977). This includes attempts to flee, thus she could face... | null |
2t1xqj | Some economists consider Social Mobility to be more important than inequality in a society's health. Apart from the United States, is there any civilization is considered to have more Social Mobility than any others? Why do theorists/historians think this is so? | [
{
"answer": "Sorry, we don't allow [throughout history questions](_URL_0_). These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to ... | null |
ckzqsj | Is it theoretically possible to surround the sun with solar panels and “harness” the sun? | [
{
"answer": "There's a thought experiment, called a [Dyson Sphere](_URL_0_) (after physicist Freeman Dyson who popularized the thought experiment), that does this.\n\nThe engineering required to achieve this is far beyond our current capabilities, making it a highly theoretical concept.",
"provenance": null... | null |
7ghr6p | Booker T. Washington's views made widespread changes to education for African-Americans, but did his views affect education for white people today? | [
{
"answer": "One possible thread to investigate is the relationship between Washington and contemporaries like John Dewey and Ella Flagg Young. There are some interesting primary sources that speak to the time the two men were in the same place at the same time and how those interactions lead to changes across ... | null |
3u18b6 | Can you get vitamin D from the moon/moonlight? | [
{
"answer": "Based on values obtained from the Wikipedia for Moonlight and Sunlight, the light of the sun can vary between 120,000 lux and 400-200 lux depending on atmospheric conditions. The average lux value of moonlight is around 0.1. With that in mind while it may be theoretically possible to utilise moonli... | null |
35c7a6 | What does marinating a meat (chicken, fish, steak) in lemon/lime/orange juice do to the meat? | [
{
"answer": "An acidic environment will denature proteins - like heat does. That's the reason you begin to see white in chicken like if it's cooked. It's the principle behind [ceviche](_URL_0_).",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "36655054",... | null |
30d2fd | how do government officials justify trading 5 terrorists for bowe bergdahl, who's now facing charges, but not making trades for all the aid workers that have been killed? | [
{
"answer": " > Aid workers that have been killed. \n\nProbably because they're dead, I suppose. ",
"provenance": null
},
{
"answer": "per the former gitmo commander, those 5 were scheduled to be released at the end of 2014 anyway due to no prosecutable evidence.",
"provenance": null
},
{
... | null |
21lye9 | How can the gravitational field of an object slow another object if it cannot expend energy? | [
{
"answer": "The asteroid loses kinetic energy and gains potential energy. ",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "125769",
"title": "Binding energy",
"section": "Section::::Mass-energy relation.\n",
"start_paragraph_id"... | null |
1am0de | steubenville rapists | [
{
"answer": "It's an open and shut case, really. The only angles of interest were (a) the rapists were high profile sports players, indicating they had some community support behind them, and (b) the large degree of social networking used by the rapists and the other students. ",
"provenance": null
},
... | null |
bs992c | why does alprazolam stay in your system for 1-6 weeks when the half-life is always the same? | [
{
"answer": "There are going to be three main reasons for this. First, the half-life of the drug is the time for half the material to break down, meaning there is rare chances for some of the material to last longer than usual. It's an estimate, not a guarantee.\n\nSecond, and more important, is the fact that d... | null |
1hftx7 | i'm sitting at a stoplight and there are several cars in front of me. they all have there blinkers going at different intervals, except for a short period of time when they completely coincide. what is happening?? | [
{
"answer": "If car A's turn signal is blinking every 1.3 seconds, and car B's signal is going every 1.4, they won't match up. However, since one car's signal is faster than the other's, it will eventually 'catch up'. While they won't be perfectly in sync, they'll appear to blink together for a second or two be... | null |
26mret | why tv shows and movies can get the rights to show certain video games, but never the actual sounds/ music. | [
{
"answer": "A lot of music, especially, is licensed from someone else for the game. So if they're showing Tony Hawk's Pro Skater 2, they have permission to show the video game. If they want to play the music (\"When Worlds Collide\" - Powerman 5000), then they have to get permission from Powerman 5000 or their... | null |
azhtok | Was it possible in 1943-45 Nazi Germany for a fit, early 20's man to NOT be in the military? What one would have had to do to avoid service? | [
{
"answer": "Sort of a tongue-in-cheek follow-up question. Could you be fit early 20s Jewish man and serve in the military and is there any difference in the service required? I'm thinking analogous to African Americans serving in WWII. ",
"provenance": null
},
{
"answer": "Related question: How was... | null |
qgbog | Strange black rock/mineral or meteor(?) I found, can someone identify it? | [
{
"answer": "Interesting crystal structure... don't think it's a meteor, they don't tend to have any sharp features. Is it magnetic?\n\nAt a guess i'd say maybe some sort of igneous rock or maybe a leaf fossil. Couldn't say for sure though.",
"provenance": null
},
{
"answer": "Notice the piece is fl... | null |
2hlkbh | How "thick" would a gamma ray burst be? | [
{
"answer": "Gamma Ray Bursts have a usual duration of some seconds to some minutes; the avarage of \"normal\" gamma rays is a bit more than half a minute. Some of them however had a lifespan of some minutes to hours, with a record of some weeks. Those are very rare, however. \n\nAsking for a planet killer, th... | null |
1nd7sd | why do drift cars turn their wheels in the opposite dirrection they need to go? | [
{
"answer": "To keep the car from spinning out, as you know the objective of drifting is to slide the car through a corner without making it spin, turning it opposite of the turn counters the cars drifting therefore stabilizing and balancing the drift.",
"provenance": null
},
{
"answer": "As the dri... | null |
1zpeyf | How do we measure time in circuitry? | [
{
"answer": "There's a great [engineer guy video on quartz clocks](_URL_0_) that's worth watching.\n\nBasically there are two sides to the system. First, you create a very small \"tuning fork\" of quartz, which has a very precise resonance frequency (typically 32,768 Hz, for reasons that will be explained). Qua... | null |
n8516 | Why do certain things that shock/scare us give us the jitters/shock which basically makes us useless and other things give us super strength(hysterical strength)? | [
{
"answer": "This happened to me on my motorcycle during an near miss crash with another vehicle. I had the jitters and couldn't immediately lift my bike, it's like my mind was so all over the place I couldn't focus my mind enough to continuously drive my muscles to lift my bike. Strange feeling, the best compa... | null |
6ttlfj | can weather or storms actually be controlled or man made? if so, to what extent and how? | [
{
"answer": "Short answer: yes to a very limited extent\n\nLonger answer: not in any realistic, safe, or controllable way.\n\nWeather is super complicated and often pretty hard to predict. Imagine if you had a big bowl of water and you kept sloshing it around, meteorology is guessing/analyzing where individual ... | null |
1gfneq | How does one computer share its private key with another computer? | [
{
"answer": "The idea of public-key cryptography is that the first computer shares the public key, and keeps the private key to itself. The second computer encrypts data (typically, a randomly generated session key for symmetric cryptography, which is much faster than public-key cryptography) with the first com... | null |
3jbxt9 | why don't companies like nintendo and sony put their retro games on steam? | [
{
"answer": "Companies like Nintendo and Sony already have their own game distribution platforms and they're generally very wary of using other distribution channels. \n\nIf they distribute games through Steam, they ultimately would have to give up lots of control over the distribution and pricing of the games.... | null |
4qc20c | What specifically is stopping people from finding an analytical solution to the Navier-Stokes equations under turbulent conditions? | [
{
"answer": "It's not my field, so I can't say too much so I will just paraphrase a couple points that Terry Tao made in a [Post](_URL_0_) about why it is hard. (If I say anything horridly wrong, please correct me.) He says that there are three general strategies to solving these kinds of nonlinear PDEs.\n\n* F... | null |
12nwod | What distinguishes alpha, beta, and gamma radiation from other types of ionizing radiation? Why doesn't neutron radiation fall into the same category? | [
{
"answer": "Gamma radiation is distinct from the other three. Alpha (helium nucleus), beta (fast moving electrons), and neutron radiation are classed as particle radiation, while gamma radiation is a high-energy electromagnetic wave.\n\nNeutron radiation isn't mentioned along the other three because it can't d... | null |
2di06q | how was code invented before code? | [
{
"answer": "you programmed in binary by flipping toggle switches. after that came punch cards. ",
"provenance": null
},
{
"answer": "Machine language is a code that CPU can run directly. Many years ago some brave young men and women wrote a series of machine language programs that converted asse... | null |
2rp337 | if you lose your genitals will you lose your sex drive too? | [
{
"answer": "No.\n\nYour sex organs are not the only \"source\" for your sex drive. It affect it in some ways, although there is no consensus about how much.\n\nIn losing them, you'd fail to act upon these desires, but your capacity to feel them would not disappear completely.",
"provenance": null
},
{
... | null |
mkfr1 | What would it take to make a virus like Ebola or HIV airborne? | [
{
"answer": "I think there already is at least one strain of ebola that is airborne, but is harmless to humans. Ebola Reston or something. Thank you Hotzone.",
"provenance": null
},
{
"answer": "I think there already is at least one strain of ebola that is airborne, but is harmless to humans. Ebola ... | null |
4wywe3 | What is the full chemical process when tea is brewed with tea leaves, a pot and a kettle? | [
{
"answer": "It's mostly just dissolving solid mateirals into the hot water. Then, they diffuse.\n\nSo, chemically, it's pretty much the same as mixing sugar, salt, whatever into water.\n\nThe compounds become solvated and form hydrogen bonds, then can diffuse through the water.",
"provenance": null
},
... | null |
vv31l | could someone explain why astronomers use julian dates? | [
{
"answer": "Astronomers like Julian dates because they make math simpler for events that don't have anything to do with the Earth year. If a variable star has a period of 270 days, it is a lot easier to add subtract 270 than it is to count through all the months to figure the exact date.\n\nWhy 4713 BC? It i... | null |
9v7swo | placebo side-effects - i think i understand the placebo effect but how can your body create a side effect? | [
{
"answer": "From what i understand, its the power of over believeing, then realizing it has to make up the difference when it realizes some part didnt happen",
"provenance": null
},
{
"answer": "Basically if you believe hard enough, your body will try and make it true. Obviously it can’t do as much... | null |
15mc6s | Why is a telescope not called a macroscope if its the opposite of a microscope? | [
{
"answer": "If you look at the etymology, 'tele' is Ancient Greek for 'far away'. So a 'telescope' is something used to look at things 'far away'. \n\n\nIf it was a 'macroscope', it'd be used to look at big things. ",
"provenance": null
},
{
"answer": "It's not the opposite of a microscope. Both to... | null |
1q0lwf | could someone eli5 why java is so insecure? | [
{
"answer": "Because Java is everywhere! The more popular something is the more it will be exploited. ",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "16389",
"title": "Java virtual machine",
"section": "Section::::JVM specification.:B... | null |
vodgq | 4-dimensional space and hypercubes? | [
{
"answer": "[Carl Sagan did a pretty good ELI5 on this topic.](_URL_0_)",
"provenance": null
},
{
"answer": "\"Imagine a 3D cube. Now add one dimension\" -- mathematicians",
"provenance": null
},
{
"answer": "Like a 3D cube casts a [2D shadow](_URL_0_), a 4D cube casts a 3D shadow, so [... | null |
1mio2b | when you ignite your propane barbecue, why does the flame not travel down the hose and into the tank? | [
{
"answer": "The propane needs oxygen to be able to burn (burning is just chemically combining with an oxidizer), and there's no oxygen in the hose. As long as the pressure is such that the propane is constantly pushed out, then oxygen can't get in, and the propane in the hose can't burn.",
"provenance": n... | null |
usssg | What are the possible evolutionary causes of missing baculum (penis bone) and penile spines in humans? | [
{
"answer": "Sorry you're incorrect, pearly penile papules are not a \"condition\" they are 100% normal, and are considered a simple anatomical variation. Please do not mistake these as any kind of STD or a vestigial form of a penis spines as they are histologically very different (keratinized epithelial vs va... | null |
zcnnx | Has there ever been a society where 2 very different languages coexisted together? | [
{
"answer": "Would [Yokota Air Base](_URL_2_) count, perhaps? Or [Incirlik AB](_URL_0_)? Military personell often go off-base for shopping and tourism, leading to a lot of multilingual fun in those areas.\n\nA little less recently, I think [South Africa](_URL_1_) counts as a nice coexistance (linguistically, no... | null |
2qz2vr | why do headlights at night seem to blind me while headlights in the day do not if their intensity stays the same? | [
{
"answer": "Your pupils are larger at night as there's less ambient light. Bright headlights in that situation let in more light than you can handle.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "418780",
"title": "Headlamp",
"sectio... | null |
3nhuve | how do supermarket trolleys get "stuck" to escalators and then suddenly work again once they've moved off? | [
{
"answer": "Magnets is exactly right. The magnet holds the trolley to the escalator, and the grooves just help to keep the trolley centered so it can be pushed off at the end.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "33261423",
"title": ... | null |
2zi8eh | how can shows such as house of cards have differing writers and directors every few episodes, yet still remain consistent in tone and feel? | [
{
"answer": "The producer for the series hires people with a similar sensibility and gives guidance so that they maintain a consistent tone.",
"provenance": null
},
{
"answer": "This is common in most tv shows. The demands on the writer and especially the directors mean a single writer/director can'... | null |
1noiud | Have there been studies documenting the effects of hallucinogens on people with blindness or other sensory deprivation? What did they find? | [
{
"answer": "This is really complex. If I were you, I'd check out the book \"Hallucinations\" by Oliver Sacks, as he talks about this extensively. In short, people who become blind can have hallucinations after - this disease is called Charles Bonnet Syndrome. It generally believed that when the brain is depriv... | null |
8yd2ok | why can’t you donate menstural blood? | [
{
"answer": "Well more or less because its basically uterus wallpaper not exactly just blood like you would find in your veins.",
"provenance": null
},
{
"answer": "It's not like blood from the rest of your body at all. Menstrual blood is filled with dead cells of the uterine lining, as well as a d... | null |
23fmae | how do superchargers make cars go faster? or why? | [
{
"answer": "Put simplistically, the power from an engine is made from the combustion of fuel and air. A supercharger compresses the incoming air, allowing more to enter the engine. More fuel is added to the engine via the fuel injectors, and the two combined combust to create more power than would have otherwi... | null |
3bkb0m | how do television ratings translate into monetary benefit for the stars of the show? | [
{
"answer": "That's basically it.\n\nThe amount actors are paid is based on the previous season's ratings/advertising. So usually the during the first season of the show, the actors aren't paid very much. \n\nThe exception would be for actors who themselves carry aadvertising value and are assumed to bring mo... | null |
fdr3lp | Are there any organic materials that harden over time or when exposed to the air? | [
{
"answer": "A poison dart frog kept in captivity will no longer be poisonous when kept on a diet of superworms and crickets. They become poisonous from what they eat. \n\nAluminum becomes harder when it oxidizes to the point that we use aluminum oxides as the grit in sand paper. Maybe the dragon somehow proces... | null |
um4qp | Do astronauts shave in space or do they wait till they get back? Mostly they look clean shaven - so I guess yes. However, with everything in space about 16 times more complicated than back on the planet...I just wondered | [
{
"answer": "Here is a [description from the Canadian Space Agency](_URL_0_).",
"provenance": null
},
{
"answer": "I don't know if you have Netflix, but if you do, watch Part 3 of the Discovery series \"When We Left Earth.\" Go to 28 minutes in and you will see Neil Armstrong (I think, hard to tell)... | null |
3bz6zp | Why did the Romans build on top of things? | [
{
"answer": "The phenomenon you are noticing is called \"stratigraphy\", which is the idea that things are built on top of older things, and you can tell which things are older by figuring out the order in which each part was laid down. It's one of the most basic and essential parts of archaeology.\n\nNow, why... | null |
ehc1e5 | why can you bring extremely fire hazardous items as hand luggage on an airplane? | [
{
"answer": "Fires are a threat that aircrews are trained to deal with and lie within their response capabilities.\n\nAnti-terrorism forces worry about things that could take down an airplane (fuselage penetrating explosives) or allow a plane to be highjacked and used for terrorism. Fires are neither.",
"p... | null |
1lle23 | Why does a small crack make a "strong" material so much weaker? | [
{
"answer": "This happens because [stress concentration](_URL_0_) occurs around the crack. Even though the average stress throughout the material sample is only slightly higher, the localized stresses at the end(s) of the crack are much higher.\n\nThe maximum stress around a crack is proportional to (a/b)^(1/2... | null |
66cvl1 | How do we define irrational exponents? | [
{
"answer": "* _URL_0_\n\nYou can also use the sub search function:\n\n* _URL_1_",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "99491",
"title": "Exponentiation",
"section": "Section::::Real exponents.:Limits of rational exponents.\n",
... | null |
3mx2nu | Is the ANY evidence at all of Native Americans travelling to Europe before Columbus? | [
{
"answer": "There's always room for discussion, but perhaps the section [Travel and contact across the Atlantic before Columbus](_URL_0_) in our FAQ will answer your inquiry.",
"provenance": null
},
{
"answer": "There's [some genetic evidence](_URL_0_) that Native American women (if not men too) re... | null |
3mmrj1 | what are the reasons behind the various sizes of books? | [
{
"answer": "It depends on who the book is targeted at. Harry Potter for example, wide pages, big letters, lots of spacing, easy for a child to read. Then Game of Thrones, short pages, smaller font, closely spaced. Made to be read by adults. Also, the length of the book. HP books are wide but not a lot of pages... | null |
cscq4u | how do cereal makers decide which vitamins and minerals to fortify a certain cereal with? | [
{
"answer": "The reason I'm asking is because I was looking at the back of random cereal boxes at the store, and thought it was weird how much of a huge spectrum of vitamins and minerals there are. They have very different choices in different cereals, even by the same makers! \n\nIt even just varies greatly wi... | null |
fkm7bi | How the South and North of Italy in 1861 were? Some say if it weren't for the south of Italy, the north would be still third world today. How much is it true? | [
{
"answer": "The \"Southern Question\" is indeed one of the longstanding dilemmas of Italian Economic History. Research into this topic is not as florid as you might initially think: for much of Italy's unitary history the \"Southern Question\" was perceived as a principally political topic, and it's only in l... | null |
72dzkc | Why would space planes not be a suitable method of interplanetary travel in comparison to typical rocket designs? | [
{
"answer": "Our main problem in space exploration is the cost of launching into orbit. It's in the order of several thousand US$ per kg.\n\nSo, first of all, consider how much fuel you need to achieve orbit. [Here's a picture of a Space Shuttle on the launch pad](_URL_0_). Note how the huge fuel tank is larger... | null |
bao9m7 | John Adams wrote that the US constitution was, "made for a moral and religious people," and that it is, "wholly inadequate to the government of any other." What elements of the constitution did he believe were suited for a religious society but not an irreligious one? | [
{
"answer": "It is interesting how many sites quote these particular lines, but provide no context, or even bother to cite the origin. Most of them do so with the obvious intent of saying that the US is a religious country, and has to be a religious country because John Adams said it had to be religious country... | null |
3e44yp | Was there ever a black American mafia as structured as the Italian and Irish? | [
{
"answer": "Absolutely, in many major (and minor) American cities, there were wings of what we would call the \"Black Mafia.\" Typically unrelated but very powerful crime syndicates in the African-American parts of town. Phildelphia, Chicago, New York and Detroit each had their own families, syndicates, brothe... | null |
b6qmpz | What did the Egyptian and Syrian governments believe about Israel's nuclear weapons capabilities in the run up to the Yom Kippur War? | [
{
"answer": "Oh, this is such a good question, I can't believe I let it languish for 25 days! Sorry for not procrastinating on my other work earlier so I could answer this; I mean that sincerely, I love this question :).\n\nFrom the first, I think it's important to mention that Egypt at the very least was aware... | null |
76bx69 | About innovations and disruptions in the past 100 years I feel that there was a true peak of innovations in the early 20th century (1900- 1930). Is there any proof in academic literature of this as well as explanations why there have been so many innovations during that time? Or am I just biased? | [
{
"answer": "The innovations pioneered around that period were arguably more broadly and popularly *impactful* than other periods, but that doesn't mean they were more numerous. The changes in that era were profound - a way of life that had continued fairly unchanged for many centuries was fundamentally altered... | null |
3thddu | How do companies like Jack Daniels that make a product that needs to be aged for years predict how much product they will need in the future? | [
{
"answer": "This is a question that I've pondered for a while too. And seeing that these products practically need to be aged, does that mean you're looking at running at a loss for the first few years before the first batch? Or is it more that these things started out as family affairs as a side project to th... | null |
zkfwz | How far can a raindrop travel horizontally begore hitting the ground? | [
{
"answer": "I don't see anything besides wind speeds and the altitude of the cloud coming into play. Best bet would probably be to look up the most windy hurricane and find out how far away from the edge of its clouds people felt the rain.",
"provenance": null
},
{
"answer": null,
"provenance":... | null |
mxnpy | What would an observer in the farthest galaxy see? | [
{
"answer": "As far as we've been able to test it, the Cosomological principle holds. The universe looks generally the same no matter where you are.\n\nWhen you are is a slightly different story. The universe only because transparent when it was 380 000 years old, so you see a wall at that distance, in all di... | null |
2z65h4 | Why is mercury-vapor used instead of non-harmful noble gases in lamps? | [
{
"answer": "Mercury vapor gives off uv light which is the right wavelength to excite the phosphor coating on the inside of fluorescent tubes. None of the noble gasses emit a white light which is comfortable to the eye. ",
"provenance": null
},
{
"answer": "Because the other gases fluoresce differen... | null |
9g8hjb | Exactly where was FDR when he found out about Pearl Harbor? | [
{
"answer": "At about 2pm ET the President was in the Yellow Oval Room on the second floor of the White House with friend and aide Harry Hopkins when Secretary of the Navy Frank Knox called and first told him if the reports from Pearl. He was called again a few minutes later by Admiral Stark the Chief of Naval ... | null |
7p81ss | What happens if I get hit by a gamma ray? | [
{
"answer": "You *are* getting hit by gamma rays all the time.",
"provenance": null
},
{
"answer": "One? Nothing.\n\nNot only are you getting hit by gamma rays all the time, you're probably producing a few. The radioactive decay of the potassium in your body will occasionally produce a positron, whi... | null |
3ykjgv | Say I am an author around the 1850's in the USA, and I just wrote a book, and I want it published. How would I go about that? Were there any distinguished publishing companies? Do I just make a lot of copies and distribute them in book stores? | [
{
"answer": "There was a fairly flourishing US publishing industry by the 1850s. For example, Melville published with Harper and Brothers (which is is extant as HarperCollins), Poe with Putnam (also still extant as an imprint of Penguin), Hawthorne and Thoreau with Ticknor and Fields, Emerson with Philips, Sams... | null |
17mjvi | Do bacteria exhibit a noticeable daily cycle in how they act and react? | [
{
"answer": "Yes even bacteria can exhibit [circadian rhythms](_URL_0_) \n \n[Here](_URL_1_) is an example that is especially intriguing. The Viking Mars lander of 1976 tested labeled elements on Mars soils samples. They found the soil \"consumed\" the elements and detection of exactly the same (labeled) el... | null |
871jeh | how can dust damage electrical components? | [
{
"answer": "[dust corrosion](_URL_0_) \n\nDust contains all kinds of different elements, including some salts. The accumulation of these minerals over time paired with humidity, creates a salty solution, which then does what a salty solution does and eats into the material. \n\nI knew about this immediately be... | null |
2bmohj | At what point would an outside observer have begun to make a distinction between Judaism and Christianity? | [
{
"answer": "Not to put off any further answers or follow-up questions, but [this healthy discussion](_URL_0_) may be of help to you.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "20015427",
"title": "Origins of Judaism",
"section": "S... | null |
4884lf | asian men wearing a western suit is acceptable, but why is it weird for a white guy to wear a kimono? | [
{
"answer": "Because you are more used to seeing an Asian guy wearing a suit then a white guy wearing a kimono.",
"provenance": null
},
{
"answer": "Western suit? I don't really know, but I think it's safe to assume that suits in general is a general worldwide thing. Its just business attire. Where... | null |
1nq6ti | Why did the Dutch golden age end? | [
{
"answer": "The main, overarching reason was that the Netherlands were just too small. They tried quite hard, and for a while, quite successfully, to be a great naval and colonial power, but England and France and Spain had just too many men and resources for them to compete with. Eventually, They were forced ... | null |
6yzphi | why do avoiding left hand turns save gas? | [
{
"answer": "If you have thousands of trucks, avoiding the time spent waiting to make left turns across traffic can add up, especially if your planning routes with dozens of stupid. In your personal life, where you only have two or three destinations, your never notice the difference or even travel further.",
... | null |
54ze4a | how likely is it to survive a headshot? | [
{
"answer": "There are notable cases of people surviving a bullet that actually enters the skull and penetrates the brain. Malala Yousafzai, Gabrielle Giffords, and although it's not a bullet, you have to remember Phineas Gage, who survive a steel bar through the head. So yes, it's survivable, although the degr... | null |
4yw2cq | How dangerous was it for World Leaders to meet during WW1 & 2? | [
{
"answer": "So the most spectacular example of this going terribly comes in June of 1916.\n\nField Marshall the Lord Kitchener of Khartoum, who was serving as Secretary State for War was traveling to Russia in order to participate in negotiations and planning in person with the distressed Czar's government. He... | null |
97xiux | how many appliances can i plug into a single socket (using series of extension chords) without 'something going wrong'? | [
{
"answer": " > I have a single socket in my room, and I use a series of extension chords to run a few ~~high~~low-power appliances such as a laptop, monitor, PS3, lampshades, speakers, LEDs etc.\n\nFixed that for you\n\nEverything you listed consumes 200W or less. The laptop is probably around 30W while the mo... | null |
8o89t6 | why is it that when driving in cruise control, going uphill feels like the car is going much faster when in reality it’s maintaining speed? | [
{
"answer": "When the car is in cruise control it is monitoring and attempting, as you said, to maintain the speed it was set to. When you go up hill the car faces more resistance as it has to work against gravity more, so when in cruise control this causes the car to slow down, the car notices this and then at... | null |
3mq5ov | Why is Carbon and Water so fundamentally necessary for life? Couldn't an extraterrestrial lifeform be based on, let's say, silicium? | [
{
"answer": "Water is important because it is a potent solvent and is liquid in a temperature range that is conducive to organic chemical reactions.\n\nCarbon is important because it is fairly inert once in molecules so you can form many long complex molecules off the same more or less inert back bone. this has... | null |
1u6yrm | When the slaves (in America) were set free, did they take the name of their master? | [
{
"answer": "According to Eric Arnesen in *The Black Worker: Race, Labor, and Civil Rights since Emancipation* and Richard Valelly in *The Two Reconstructions: the Struggle for Black Enfranchisement*, slaves so despised their masters that one of the first things they did as freemen was change given names. Inste... | null |
608dui | why do car batteries only need to be charged when fully dead? | [
{
"answer": "They are actually charged every time you drive. This happens with a machine called an alternator. \n\nWhen your car engine is running, it also turns a little electrical generator that helps keep the car battery charged. ",
"provenance": null
},
{
"answer": "Car batteries are kept charg... | null |
eshckn | is there truly any way to get over non-seasonal allergies? | [
{
"answer": "I got allergy shots for six years. Granted most of mine were seasonal or at least flared up in spring/fall. Now I’m very glad to get those because I rarely have to even take meds for it.",
"provenance": null
},
{
"answer": "Yes when i was younger i was very allergic to dust, well actual... | null |
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