id stringlengths 5 6 | input stringlengths 3 301 | output list | meta null |
|---|---|---|---|
1g94zl | What is the oldest known human structure? | [
{
"answer": "What about [Gobekli Tepe, in Turkey?](_URL_0_) That seems to go back to about 9000 BC, and although it's not a \"building\" per se (as in walls and a roof), it is a structure. I don't know if anything older is evident beyond the barest of remains (campsites, et cetera) but in terms of monumental ... | null |
2thad7 | how can we use telescopes to see into the far reaches of space, generating massive resolution images, yet we have to send a spacecraft like dawn to see a white spot on ceres? | [
{
"answer": "The things that we can see far away are **very** big and **very** bright.\n\nYou can easily see a billion burning candles arranged on a hilltop miles away in a pitch-black night (seeing another galaxy filled with billions of stars), but good luck seeing a discolored spot on a grain of sand 10 feet ... | null |
48fedx | Is it possible to observe the process of a star becoming a black hole? | [
{
"answer": "You're most likely to see a regular supernova and that's it. Black holes are not visible so without any special equipment you wouldn't even know it's there when it forms only it's interactions to other objects can be detected.",
"provenance": null
},
{
"answer": null,
"provenance": ... | null |
2280u7 | what do we know about what goes on inside of other planets in our solar system? | [
{
"answer": "Not a whole lot of direct study. We can make some measurements - for example, we know their mass and size, so we can calculate their density, which tells us something about what they're made of. Saturn, for example, is very light - less dense than water - so it can't have much of a solid core, if i... | null |
1psljm | - where do "royals" obtain their original claim of "royalty" from? | [
{
"answer": "Well before the Enlightenment, everyone just agreed on whatever the Church told them.\n\nThe Church and the royals worked together, so the people never really questioned their leader much.\n\nJames I was the first (no pun intended) to declare \"divine right\", which is the idea that God placed the ... | null |
f437r8 | How does the monarch butterfly change its lifespan between generations? | [
{
"answer": "Several things to consider here :\n\n* First of all, the genetic information doesn't say \"that individual will live this long\", it's more like the lifespan depends on many other genetic traits. That means it's not genetic information changing form a generation to another. At most, the phoenotype ... | null |
6ru00i | The "germ theory of disease" Wikipedia page suggests that germ theory had many antecedents (people talking about "pestifera semina") going back to antiquity. Why was miasma theory popular as of the 19th century? | [
{
"answer": "I've been meaning to write an answer to your question since you posted it, but I didn't get around to actually writing it. Well, I hope that you're still waiting for an answer. \n\nI have a few problems with the history-sections of that Wikipedia page. The most basic would be that it doesn't paint ... | null |
mgkk7 | What prevents the intestines from tangling themselves like my headphone cords? | [
{
"answer": "They are held in place by connective tissue. It doesn't give them much room to move around.",
"provenance": null
},
{
"answer": "They can get tangled, and it is a very serious medical problem that if left untreated can kill a person. \"Luckily\" it is also exceedingly painful, so it rar... | null |
k1hsr | antitrust lawsuits | [
{
"answer": "Let's say you have two companies selling apple. Now both companies will sell apples at a good price, let's say that price is $1 an apple. If ether company was to raise their price then they'd sell less apple cause who would want to buy an apple for $1.50 if they could buy an apple for dollar.\n\nOn... | null |
kfd21 | why can't we recreate dinosaurs just like in jurassic park? | [
{
"answer": "To create clones you need to take the nucleus of a cell of one animal and place it in an egg without a nucleus of the same species. This is then given to the female and is grown in the normal fashion. Blood (in human's certainly) tends not have cell nuclei, hence it wouldn't be possible for human... | null |
33x7do | sd cards | [
{
"answer": "You are right the plastics bits and the copper contacts that make up moth of the SD card that you can see have a negligible price. They are not worth much.\n\nThe actual flash memory itself inside the card is what makes up most of the price. It consists of stuff like silicone and metals and other s... | null |
1oaldb | if a bank goes out of business and i happen to have a mortgage with said bank, what would happen? | [
{
"answer": "They would sell your debt to someone else as a way of paying off their debts, and now you owe your mortgage to some other entity.",
"provenance": null
},
{
"answer": "Essentially, the debt they have on you is an asset, in much the same was a copy machine or the office desks are an asset... | null |
96x8vk | Are planets exclusively formed after stars from the remaining material, or are there other natural ways we've observed/theorized planet(s) forming? | [
{
"answer": "Technically speaking a planet is defined as an object orbiting a star, though this gets a bit problematic when considering rogue planets that have been ejected from their stars.\n\nThe same process that leads to star formation--collapse of cloud of gas in a nebula--can sometimes fail to collect the... | null |
qw1bu | Resources for Medieval Church/Choir Music | [
{
"answer": "The answer sort of depends on exactly what you're looking for. Most of the music used in video games and movies is composed recently, it's not authentic medieval music. They get the same sound by using a lot of open fourths and fifths, but real medieval music would sound horribly boring in a mode... | null |
8tnr78 | What did the people of the Spanish peninsula look like before the Moors arrived? | [
{
"answer": "Hi there! So if we're talking about what they \"looked like\" I'm assuming you meant in terms of their actual physical appearance. The short version is that there was an array of people and cultures in Iberia and their appearances varied accordingly. The racialist myth of \"the white iberians befor... | null |
1imlbm | the difference between poisonous and toxic things | [
{
"answer": "The term poison refers to any substance that is harmful to your body if consumed. Toxin is a specific branch of poison, defining naturally created poisons. For example, many household cleaning substances are poisonous, but are artificially made and are not toxins.\nHere is the Article my informat... | null |
30n57t | If there was no oxygen and paper was heated to a super high temperature, would it melt not burn? | [
{
"answer": "Yes. There couldn't be any chemical reactions, and if you reach the necessary temperature it will break down into its parts. That would happen around 250° celsius temperature. You would be left with charcoal and hydrogen gas.",
"provenance": null
},
{
"answer": " > would it just create... | null |
1iw189 | If I continuously shot charged particles into a black hole, what would happen over time with the buildup of charge? | [
{
"answer": "From the [no-hair theorem](_URL_0_), the only things that external observers can measure from a black hole are its mass, charge, and angular momentum. \n\nSo yes, the black hole will become more and more negatively charged, and if you were to put a test charge somewhere outside the black hole, you... | null |
3xa2bb | how did futurama win 6 emmys but got canceled twice? | [
{
"answer": "Being a good show doesnt mean a lot of people like it. A show may have great acting, amazing plot, good dialogue, etc., but the genre/premise/etc. may just not interest people. My father doesn't take animation seriously, he would never watch Futurama, no matter how much he would like it if he did. ... | null |
2yimbh | why is the letter the 47 republican senators sent to iran today such a big deal? | [
{
"answer": "Well, for one there is the [Logan Act](_URL_0_)\nAnd then again, aren't we all getting a little tired of the Republican's shit?",
"provenance": null
},
{
"answer": "Negotiating with foreign powers is the job of the executive branch (president and Department of State). The Senate is only... | null |
fvx8n5 | how do companies like gm and apple quickly pivot to making new products like masks and ventilators? | [
{
"answer": "I think it’s not so much that they switch to manufacturing masks and ventilators, they just have them already and are donating them. At least for apple and other big tech companies, their factories are big clean rooms, so they have plenty of masks already.",
"provenance": null
},
{
"ans... | null |
5d6nuu | what would happen in the usa if someone tore a ligament (such as acl) and didn't have health insurance? | [
{
"answer": "You would have to pay out of pocket. Usually if you don't have insurance, you may be able to negotiate the costs with hospital to lower the amount due. \n\nGenerally, hospitals will charge more for procedures and hospital stays if a patient's insurance company is being billed. Hospitals will never ... | null |
3iuk49 | why do people who have sex in movies/shows smoke after it? | [
{
"answer": "It's TV trope, but based on reality. Back when I was a smoker the most enjoyable cigarettes were after sex, after a good meal, and when drinking.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "60885580",
"title": "Effects of porno... | null |
1q3yb9 | What is happening in a black hole? Do we have fusion of heavy elements? Could they eventually super nova? | [
{
"answer": "To answer your last question first: no, a black hole cannot supernova. Once matter is inside its event horizon, it's in there for good. It appears, by using quantum physics to study black hole event horizons, that they can emit radiation (called Hawking radiation) which, over time—a very, very long... | null |
1st22j | please explain fetal alcohol syndrome (many more-specific questions herein) | [
{
"answer": "Wow. Four months ago. Still, I think I can add a bit to this, and hope you will see it.\nMy mother has grown up with FAS. I don't expect anyone in her family would admit it, but she has the classical facial features (you are probably acquainted with these now, but if not, google fetal alcohol syndr... | null |
1u8mrr | what is nsa doing with my information? | [
{
"answer": "It's collecting metadata (data about a conversation, not the conversation itself) into a big database so that, if the need ever arises, they can analyze that data to see who you might have conversed/connected to, or if you yourself were connected to someone.\n\nThat data would be analyzed to extrac... | null |
9ihvkv | How prevalent was looting by US troops during WWII? | [
{
"answer": "Looting by the US military during World War II fell into several categories, which can broadly be grouped as the 'legal' and 'illegal', even if lines might have blurred at times. First and foremost it can be said that the War Department maintained an official policy, laid out and periodically refin... | null |
4e8r2j | how and why we feel the emotion, "boredom" whenever we aren't doing anything? | [
{
"answer": "Well I dunno about you but if I'm not on ADHD meds I feel bored damn near constantly. Like painful, unbearable boredom.\n\nSo... in light of that, I'm going to go out on a limb and say when you're sitting around doing nothing your brain is most likely not got a lot of dopamine action going on? And ... | null |
242bxr | What is the value of Monte Carlo method? Doesn't it just return the expected set of results and variance? | [
{
"answer": "It's useful for simulating more complex scenarios. For example, I've been working on a muon telescope recently. The muon flux is a fairly well known quantity, as is the angular distribution or muons. However, since the telescope was built using rectangular scintillator paddles, and calculating a so... | null |
c1b99f | the differences and processes of rom and ram | [
{
"answer": "Rom - read only memory. The chip is programmed once, usually by using a writing voltage that is high enough to “burn” the bits in. \n\nRam - random access memory. You can read and write to it. Writing doesn’t burn bits in, each bit is just basically a capacitor that temporarily stores a charge.",
... | null |
9pcvff | why do car commercial disclaimers at the end always play so fast that you can't even understand what they're saying? | [
{
"answer": "Because the company is legally obliged to include the message but doesn't want to spend ad time that they pay for on legal requirement that doesn't help woth the sales. So they keep it as fast and short as possible. ",
"provenance": null
},
{
"answer": null,
"provenance": [
{
... | null |
2iu2y5 | Historical use of a "gun-blade"? | [
{
"answer": "Can you post a pic, or find a pic of something similar to refer to?",
"provenance": null
},
{
"answer": "[it's been asked before](_URL_0_) but wasn't answered in a lot of detail, you might find more info with the term \"Pistol Sword\"",
"provenance": null
},
{
"answer": "In ... | null |
oqfjm | Why are some pharmaceuticals bounded to an hydrochloride and some to an hydrobromide? | [
{
"answer": "There is a difference in how well the crystals form. Larger ions like larger counter-ions, typically, to make stable crystals. When making the drug you want stable crystals to recover the most product cleanly at the end of the manufacturing process.",
"provenance": null
},
{
"answer": n... | null |
5i9bgn | During the Medieval period, how often were nobility/knights/etc captured in battle? | [
{
"answer": "Not op, follow.up questions:\n\nHow are the nobles/knights/etc generally treated when they were captured?",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "194908",
"title": "Battle of Hattin",
"section": "Section::::Surrender... | null |
48ratj | radio waves allegedly detected coming from another galaxy. how long ago are they likely to be from? | [
{
"answer": "Radio astronomer checking in:\n\nYes, radio waves travel at the speed of light (radio waves ARE light, just lower energy than visible light), so the travel time is equal to the distance in light-years. Radio waves from a galaxy 10 million lightyears away will take 10 million years to get to us, or ... | null |
1244rk | marginal cost | [
{
"answer": "There are some business costs that don't depend on how productive you are. Even if you produce absolutely nothing this year, you still have to pay for building space and air conditioning and stuff.\n\nBut there are some costs that *do* depend on how productive you are. For instance, if you're build... | null |
1ngmb8 | How do we know for certain that we have found every single naturally occurring element? | [
{
"answer": "When an element is called natural, this only means that it was identified in nature rather than created in a laboratory. However, there is nothing special about natural elements, it's entirely conceivable that there may be other elements on Earth, just in such small quantities that they were never ... | null |
1bu89i | Did the big bang occur in all directions? I often hear that we can only see 13.?? billion light years before we can't see anymore, but isn't there technically another 13.?? billion light years worth of material beyond the initial bang, just in the other direction? | [
{
"answer": "The misunderstanding here comes from your idea of the \"center\" if the universe.\n\nThere isn't one. Every point in the universe appears to be moving away from every other at the same rate.\n\nThe *observable* universe \" on the other hand is spherical centered on the earth, because light has only... | null |
1if8ky | What is the history of the Smith-Mundt act? Why did congress pass a law banning domestic audiences from hearing material intended for foreign audiences? | [
{
"answer": "If you are at an institution with free access to legal databases, you can get greater depth from the legislative records cited below, but here is what I could dig up from free sources:\n\nThe initial 1948 law provides that:\n > [USIA publications] shall not be disseminated within the United States,... | null |
eji1hh | What is the status of Fredrick Jackson Turner's Frontier Thesis among historians today? Is it still used as an explanation of broader aspects of US historical trends, or closer to something that illuminates how Americans in the early 20th century thought about their own past? | [
{
"answer": "After ninety-five years (or so) of two camps - the Turnerians and the anti-Turnerians - bashing one another, there was something of a collective sigh of relief when the controversy around the Turner Thesis was set aside. Even though it was largely unresolved. The situation was so desperate that one... | null |
934hfj | What was the casualty rate for battles between hoplites in ancient Greece? | [
{
"answer": "Back in the 80s, Peter Krentz gathered all known casualty figures from Classical Greek sources in order to establish a rough average.^1 He concluded that in battles of Greek against Greek, the winner suffered about 5% casualties, the loser about 14%. These numbers are very frequently cited in schol... | null |
6sz4ln | - why does water bead up where i wrote on a dirty car, and why does it take so long to disappear? | [
{
"answer": "Oil from your skin and the fact that dust is abrasive when you write with your finger on dust it scratches the paint/ clear coat.",
"provenance": null
},
{
"answer": "This is due to a phenomenon called surface tension. The most economical position for matter to be in is that with the le... | null |
7mglm5 | why does produce from farmer’s markets cost more than organic produce from a grocery store if the middlemen are removed? | [
{
"answer": "In countries like the USA (where labor is costly), farmer's market stands are not cost-efficient. You have a whole person or two, putting in 4-6 hours of work, just to sell a couple of hundred dollars worth of produce.",
"provenance": null
},
{
"answer": "Produce from a real farmer's ma... | null |
1apyj0 | As previously stated, Soldiers from ancient times were lean and fit, what were gladiators like? | [
{
"answer": "I'm working on finding the source at the moment but, as far as I remember, gladiators were actually kind of flabby.\n\n[Edit]\n\nThe Archaeological Institute of America has an article [here](_URL_0_) that covers the research from the Austrian Archaeological Institute's study of gladiator remains.\n... | null |
9l08g1 | How did early humans switch from hunter-gatherer to agriculture? | [
{
"answer": "I actually studied this quite a bit in undergrad. The first thing to remember is that it varies by region. There are many independent origins of agriculture around the world and not all of them happened the same way. However, there are many common themes, and a major one is that it's typically n... | null |
58yqjf | whаt nutrіеnts dоеs саrtіlаgе nееd? | [
{
"answer": "The non-essential amino acids proline and glycine are building blocks for cartilage. Your body can synthesize them, but dietary intake from gelatinous meats will likely aid in your body's ability to heal. A study was done which used radioactive dye on gelatin, which was then fed to rats with dama... | null |
2pzf0t | if orangutans share approximately 97% dna with humans, why do they look so different than humans? | [
{
"answer": "The other 3%.\n\nAnd really, they don't look all that different from us. Sure, if you had 100 humans and one orangutan in a room, the orangutan would stand out; but if you had 1000 animals of all types, the orangutan and the human would look practically identical. Squid, cockroaches, snakes, and hu... | null |
z09e2 | How different was the culture and language of the Scottish Highlands from that of the Lowlands? | [
{
"answer": "When?\n\nScotti is the Latin name for the Irish, (or, alternatively, northern Irish) who frequently raided Britain. (Gael comes from Welsh Gwydel which is raider, iirc, akin to Viking meaning pirate or something along those lines)\n\nThe Gaels of the north of Ireland set up a kingdom that spread ac... | null |
662wro | $ vs. ¢ | [
{
"answer": "To avoid ambiguity, although it isn't always the case that the main currency symbol goes in front. In many languages, it goes at the end regardless.\n\nHaving it in front is useful for two purposes, however. Firstly, it helps prevent people from adding digits to the front of the number (for examp... | null |
8ptq1a | [Astronomy] Is there a correlation between galaxy age and the amount of dark matter in it? | [
{
"answer": "the part of the galaxy that contains dark matter is called the \"dark matter halo\" and contains the majority of the mass in a standard galaxy. it is really hard to accurately weigh a galaxy and determine the amount of dark matter in it, although for the ones we have weighed, it seems like there is... | null |
1094s1 | what should i be looking for when i'm reading nutrition facts? | [
{
"answer": "The most important fact you need to know: **Serving size** \nAnd also the \"Number of Servings\"",
"provenance": null
},
{
"answer": "The actual nutritional content depends on what you want to focus on. \nFor example, if you want to prevent high blood pressure, then you need... | null |
153ygr | Is there a correlation between exposure to cold weather and getting viral/bacterial infections? | [
{
"answer": "AFAIK, it's purely based on being indoors and easing the spread of germs. If the logic were that it were related to the cold, then equatorial countries would never get ill because they don't have winter (those countries get sick during the rainy season).\n\nThat being said, there is a link between ... | null |
b4100l | why/how does the gas released by freshly cut onions clear the nose and sinuses when ill? | [
{
"answer": "This \"gas\" (actually a volatile liquid) is called syn-propanethial-S-oxide. It is an irritant that affects the mucous membranes and tear glands to secrete a lot of liquid. This liquid washes out any hardened snot that might be stuck to your mucous membranes.",
"provenance": null
},
{
... | null |
4o8ck8 | Does alpha decay lead to an ion being made as the atom has lost two protons and so now has two more electrons than protons? | [
{
"answer": "Yes conservation of charge means that the resulting atom will be in a -2 charge state. Generally this state is not stable and the atom will interact quickly with local chemistry in some way to lose that charge. Some smaller atoms may even emit one of the electrons directly without requiring a react... | null |
3yx6c7 | Are there any examples of slavery supporters in the American South who changed their mind and rejected slavery (either before or after the Civil War)? | [
{
"answer": "I have no doubt there will be a great deal of examples that people more familiar with american politics then myself can state but one example would be Rebecca Fleton a georgian feminist who is mostly known for being the first female senator (albeit only for one day as a publicity stunt when she fil... | null |
6j4voh | Has a submarine ever sunk another submarine, in any war, ever? | [
{
"answer": "More than a few times. In the Pacific theater, USN submarines sank the Japanese Ro-45 (although this claim is disputed), I-28, I-29, I-73, I-168, and I-183 as well as the *Monsun-Gruppe*'s [U-537](_URL_5_) and [U-183](_URL_8_). _URL_6_ 's [Sensuikan! page](_URL_4_) has the tabular record of movemen... | null |
a6cqs1 | If graphene is a single layer of carbon atoms, how would it conduct electricity? | [
{
"answer": "It’s graphene’s structure that makes it conducive. A given carbon atom shares sigma-bonds with 3 other carbon atoms in the same layer, and pi-bonds with the adjacent layers. This pi-bond (actually pi-band) enables free electron movement, and hence electronic properties (namely conductivity). \n\nWh... | null |
1ir9r3 | can anyone recommend me some eli5-like books on finance/money? | [
{
"answer": "The dummies books are great, they have them on financing and all of those topics you talked about and they'll walk you through how to do those things. \n\nSource: success in several investments from reading those books",
"provenance": null
},
{
"answer": null,
"provenance": [
... | null |
651vuo | If deleted data can be retrieved, why can't we have our things in deleted state and keep much more space on hard drive disks ? | [
{
"answer": "This would not work because there is a limit to the space that exists on a hard drive. Data can only be retrieved from a hard drive before it has been overwritten.\n\nWhat you're suggesting is like doing this: Fill up a glass of water. pour the water out. fill the glass up again. Interpret the resu... | null |
6paa6l | Each 10m underwater adds roughly 1atm in pressure. Does that change with liquids other than water? Would it be different in planets other than Earth? | [
{
"answer": "Yes, that is specific to the density of water (d), the strength of gravity on the Earth (g). The pressure is g times d time the height of the column h, so if the density is twice that of water, only 5 meters would be required, and if the gravity were half as strong then 20 meters would be required.... | null |
2eyhce | when i'm on a cell phone, and i can hear the other person crystal clear, but they say the quality is so bad on their end that they can hardly understand me, what's going on? | [
{
"answer": "Cell towers have more power than a phone, so \"tower to phone\" is more reliable than \"phone to tower\". For example, if you are close to your tower and the other person is far away from their tower, they can hear you fine, but their return signal may have trouble reaching the tower.",
"prove... | null |
6rynyk | Did the UK ever come close to any serious food shortages in WWII? | [
{
"answer": "Not really.\n\nThe Germans had a target of sinking ~300,000 tons of shipping each month in order to starve Britain, and overwhelm British/Allied ship production.\n\nIn the first 27 months of the war, Germany only hit that target 4 times. After that, when America joined the war and added their own p... | null |
20keib | what does the chipset on a motherboard do and how does it work? | [
{
"answer": "It manages communications between the CPU and the RAM and peripheral boards.",
"provenance": null
},
{
"answer": "It lets the \"brain\" of the motherboard - the central processing unit or CPU - talk to all the other components of the motherboard like the memory, peripherals (disk, monit... | null |
3aclf8 | do animals feel growth pain? | [
{
"answer": "[They do](_URL_0_), if they have rapid enough growth like larger dogs. Since most of our pets don't have such rapid growth (cat, birds, fish), presumably they don't feel any pain. ",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "24261150",
... | null |
26mtlv | Why didn't Jordan tried to invade Israel in the 1973 war? | [
{
"answer": "It was, at least in part, because the Jordanians had cooperated greatly with the Israelis under Hussein around this time.\n\nJordan had always been hesitant to attack Israel. In fact, during the 1967 War, the Israelis believed that the fire coming from Jordan initially was just meant to show solida... | null |
r0kqb | How visually accurate are deep space telescopic images? | [
{
"answer": "I want to begin by saying that that image is most definitely not a real image. It's an artist's conception.\n\nTo the naked eye, nebulae look gray. You might seen hints of faint color here and there, but it's mostly just gray. Telescopes use long exposure times and various filters to get their pict... | null |
22cr8c | What is a soviet? How were they selected? | [
{
"answer": "The soviets themselves were Councils, think of them as political units. You can find a brief essay by Soviet Historian Lewis Siegelbaum on them here: _URL_2_\n\n(It's an excellent site for Soviet History in general, as a side note)\n\nFirst it is important to remember that there were two Revolutio... | null |
4r3bak | can you increase the speed of sound by using different gasses? | [
{
"answer": "The speed of sound is increased if the density of the gas is lower. For example, in helium, the speed of sound is 1007m/s at atmospheric pressure and 20°C, almost three times as much as in air. In a heavy gas like xenon, it's only 178 m/s.\n\nThat is because the less dense gas is easier to push, wh... | null |
lgn93 | If someone jumped off a cliff as high as the golden gate bridge into a large lake that had a surfactant (soap I guess) poured onto it, would they survive? | [
{
"answer": "Is the distance from the the very top of the highest point on the structure, or the surface of the road? There have been people that have attempted suicide and survived off of the road surface. ",
"provenance": null
},
{
"answer": "The surfactant would have no effect.",
"provenan... | null |
mrbxn | Can someone explain how those giant single celled organisms on the seafloor are possible? | [
{
"answer": "You will need to be more specific than **\"those\"** giant single celled organisms. What organism are you referring to?",
"provenance": null
},
{
"answer": "Well, they appear to have a huge amount of surface area due to their filaments, so that may be what lets them live as such huge si... | null |
1cg4sw | According to wikipedia "Current generations of nuclear submarines never need to be refueled throughout their 25-year lifespans" | [
{
"answer": "The article says it won't need refuelling in the submarine's service lifetime, for which 25 years is a typical figure. In general, nuclear reactors don't have to be refuelled very often due to the enormous energy density of nuclear fuel compared to chemical - this is one of the principal attraction... | null |
1baxy4 | why progress bars always hang on 99/100% | [
{
"answer": "Progress bar values are basically made up by the developer. For some things they work pretty good. If you are downloading a 100MB file and have finished downloading 70MB then saying you are 70% done is pretty easy. For things like installing a game, where you have a huge number of files of diffe... | null |
5vz2mk | Why didn't Italy find Oil in Libya while it was an Italian colony. | [
{
"answer": "There were some isolated discoveries during the 1920s that hinted at the possibility of oil deposits in the colony. Wells sometimes produced commercially-negligable amounts of petroleum and natural gas. An Italian geological expedition led by the explorer and geologist Ardito Desio did discover oil... | null |
wn2fu | About how far away are we from self-powered electronic devices that have batteries that don't need to be recharged? | [
{
"answer": "A battery, by definition, converts chemical energy to electrical energy. This means that, unless chemicals are replaced, or energy is put back into the system, a battery _will_ run out.\n\nYou'll find that there are [some designs](_URL_0_) out there that already take advantage of the natural body m... | null |
1uouqm | Looking for quotes on American Revolution! Can't quite remember | [
{
"answer": "Try /r/tipofmytongue also",
"provenance": null
},
{
"answer": "Perhaps one of these two?\n\n\"Nevertheless, to the persecution and tyranny of his cruel ministry we will not tamely submit -- appealing to Heaven for the justice of our cause, we determine to die or be free.\" Joseph Warren... | null |
1bpchr | Are sunsets local or global? | [
{
"answer": "Sunrises and Sunsets do vary by where you are on the globe. To start off we can look into why sunsets and sunrises can be red. The blue sky is due to a phenomenon called Rayleigh Scattering. This is were light from the sun is scattered by gases in the atmosphere. These gases preferentially scat... | null |
3iax2q | why don't we have solar powered phones? | [
{
"answer": "Solar panels don't generate nearly enough power. Solar powered calculators only take a tiny amount of power compared to a phone.",
"provenance": null
},
{
"answer": null,
"provenance": [
{
"wikipedia_id": "4105326",
"title": "GPS tracking unit",
"sectio... | null |
aufozc | How different were languages between different Native American tribes? If you could bring together an East coast and West coast tribe, would they be able to mostly understand one another? | [
{
"answer": "The short answer is no.\n\nThere are dozens of major language families throughout the Americas. [Algic](_URL_0_) is the only one found on both the east and west coast of North America, and even the handful of small Algic languages in the west have been isolated from their east coast counterparts fo... | null |
6bh372 | why do we use implants for breast enlargement instead of something biological like stomache fat? | [
{
"answer": "Fat is a living tissue. Transplants of living tissue are more expensive and have higher risk of complications. Implants are biologically inert and relatively easy to implant.",
"provenance": null
},
{
"answer": "Might also have to do with the structure of the breast and how the added fa... | null |
1gbcgw | i want to understand important nutrient information. | [
{
"answer": "Carbohydrates are sweet and starchy things, examples are: sugar, flour, bread, rice, corn, etc.\n\nFats are oils and greases. If it makes your fingers a little greasy when you touch it, it's probably got a LOT of fat in it.\n\nFor weight loss, it's pretty simple. All you want to do is emphasize g... | null |
12gb7c | how did the uk nhs system work, what did the recent reform bill do to the system and what are the reasons for it? | [
{
"answer": "There are some [great articles about the NHS reforms](_URL_2_) at the British Medical Journal's website.\n\n > And if it is really as bad as everyone says it is, why did the government implement it?\n\nMany [politicians](_URL_3_) and [peers](_URL_1_) held shares in private healthcare companies befo... | null |
6y6ey2 | how do physicists "solve" equations? | [
{
"answer": "Solving an equation is where you know the equation in one form, and want to rewrite it to another form, so it's easier to calculate the value of one of it's variables.\n\nIn your example of E = mc^2, say you know the energy E and the speed of light c, but want to know what the mass m is. You can re... | null |
5ycfrv | Sound of a Baroque Era Classical Pieces sound then then versus now? | [
{
"answer": "It's not that simple.\n\nSee, there was [no consensus on a pitch reference](_URL_1_) to the level of precision we discuss these days. There was [eight foot pitch](_URL_0_) and people used whistles and so on to have pitch references, but there was no standard. We start to see that kind of thing in t... | null |
dhognl | why do nuclear explosions take the form of a shroom? | [
{
"answer": "It's because of the air rise up. The center of the explosion is really hot, so the air expanses and it become lighter than the cold air above, so it starts rising. Then it drags the cold air around the explosion inside. \nWhen the hot air gets higher, it starts to get cold, it stops rising and spr... | null |
1o12kv | Historically, why did England dominate Ireland and not the other way around? | [
{
"answer": "I'm in a History of Ireland course right now, and we've already gone over a lot of the answer for this. England started \"dominating\" Ireland with the Norman Invasion. The problem with calling it a domination is that an Irish king, MacMurrough, appealed to Henry II for help with problems he was ... | null |
1ex4rb | difference between several types of transistors? | [
{
"answer": " > What is the difference between MOSFET; PMOS, NMOS and BJT's?\n\nFET transistors operate on electrical field, which because you're 5 we're going to just say is the same thing as voltage. Basically, with a MOSFET, it's the *voltage* between \"gate\" and \"drain\" that allows (in the case of N-cha... | null |
19xhbd | Was there a central minting authority responsible for standardization of Roman currency? | [
{
"answer": "There were several dozen mints located around the Empire in various cities, the first and most important of these was in Rome at the temple of Juno Moneta, she was an aspect of the Goddess Juno who was credited with looking after the funds of the city and its populace. The very words 'mint' and 'mo... | null |
5onq5y | why do we have two lungs instead of one large lung? | [
{
"answer": "Redundancy. \n\nIt's an evolutionary advantage to be able to lose one lung, one hand, one kidney, one teste and still function. The energy needed to run two smaller v one large is basically the same. \n\nYou hear about people with a collapsed lung living. You don't hear about people with two collap... | null |
dc2nh0 | joint cracking | [
{
"answer": "While still debateded, but we do know that carbon dioxide bubbles form in the joint cavity fluid, which then as you move your joint, would sometimes collapse.\n\nWhen the bubbles pop, you hear that distinctive pop noise. And bubbles don't form at a moment's notice, it takes time for the bubble to f... | null |
5f3374 | Hi there, could anybody help identify this WWI revolver? | [
{
"answer": "I am afraid that this is going to be a very difficult one to identify, unless there are some markings on it which do not show in any of your photographs. This appears to be a double-action only revolver, with several strange aspects to it. Generally, it appears relatively crudely made, with poor ... | null |
dd20xu | how does augmented reality work? looking for more of the technical aspect. | [
{
"answer": "By sampling a 3D space in the real world using an array of sampling technologies it simply places digital assets within a virtualized space of matching proportions in a convincing manner creating the illusion the object is physically present.\n\nIt's just showing the user a digital copy of the envi... | null |
2ntaat | What was Mexico and Canada's reaction to the American civil war? Were there any foreign volunteers or mercanaires? | [
{
"answer": "Mexico was busy fighting France. The Cinco de Mayo holiday originated around the same time, after the Battle of Puebla, and even spread to camps in the states.\n\nCanada was still British. The South begged Britain to join their cause, and they thought that the British would want to break the bloc... | null |
5um071 | why do elevators decide to wait at the floors they do? | [
{
"answer": "Most wait at the floor they are left. But some might be smart as to go back to the ground level so people can get to their workplace quicker and have to wait less to fetch one.",
"provenance": null
},
{
"answer": "The simplest solution is to have elevators wait whereever they were calle... | null |
6z1t2f | how do we not notice rubber on the roads if tires slowly wear down on them? | [
{
"answer": "The quantities are super small and it doesnt stick to the road so well. If you put your hand to the road you may feel dust, and that dust is at least partially rubber.\n\nIf it helps you can visualize them more as smaller versions of that residue left over from using an eraser.",
"provenance": ... | null |
4bpsmf | in every crime show it's a different profession investigating and solving crimes. who actually does it in real life? | [
{
"answer": "When crimes are investigated there are different professions involved. \n\nThere are your standard beat cop who is the first to respond. Then there are specialist cops called detectives who are assigned depending on the type of crime. These would be the division that deals with homicides, or in the... | null |
26gy8k | How did people make coffee in the days before electricity? | [
{
"answer": "Turkish coffee is made by heating a pot of water, coffee, and usually some sugar and spices until it boils and then quickly removing it from the heat source after it's begun to boil. [Here's a video.](_URL_1_)\n\nThere's also 'cowboy coffee' which is just throwing the grounds into a pot of water an... | null |
2x8foa | When astronomers say something will happen in x amount if time, to something very far away, do they mean when it will actually happen or just when the light it emits gets to us? | [
{
"answer": "Usually, when talking about future events, astronomers talk about when we will observe that event. So, in your example, in our reference frame, we will observe the star's death 1,000 years from now. However, in the star's reference frame, the event happened 1,000 years ago, and for an observe who i... | null |
3yrnje | Mechanics: Mathematically, what is the thought process behind moment of inertia and why is it used in mechanics of materials? | [
{
"answer": "_URL_0_\n\nThe integral is basically summing up the individual moments of inertia for each differential mass element of the object, treating them as tiny point masses. And the moment for a point mass is mr^2 .",
"provenance": null
},
{
"answer": "The \"moment of inertia\" is like mass, ... | null |
aj3a1z | why is stagnant water unsafe to swim in? | [
{
"answer": "Bad things grow in stagnant water like bacteria and parasites. If you get into the water, there’s a good chance they’ll get into you...",
"provenance": null
},
{
"answer": "In stagnant water all kinds of interesting biological phenomena are developing. They are also developing in flowin... | null |
1gw5ru | how do politions who aren't in power get paid? | [
{
"answer": "They are paid for public appearances, become paid lobbyists, do work like writing books or editorials in papers, work for political organizations, etc etc. There are a lot of positions in politics that don't necessarily involve public office. \n\nEdit: In the US at least. ",
"provenance": null
... | null |
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