Subset (10)

eli5 · 25k rows

Split (1)

train · 25k rows

query stringlengths 20 300	positive listlengths 1 1	negative listlengths 1 1
Does the temperature of air effect the distance sound can travel?	[ "Yes, temperature is one of the things that affects sound attenuation in air. ISO 9613-1 provides a standard method of estimating this. Generally sound attenuation is lower in cold air. Sound will also curve away or towards the ground due to a temperature gradient since the speed of sound is dependent air density. ...	[ "Not noticeably, no. Bring a hot cup of coffee into the car instead, it will work much better than Metallica." ]
Why do small blackholes emit more Hawking radiation than large ones?	[ "The Entropy of a black hole is encoded on its event horizon, while the energy of a black hole goes as the radius. This means that the derivative of energy vs entropy which is the definition of tempurature goes as a function of the radius of the black hole. What's interesting about this scenario is that it is inver...	[ "You're thinking correctly. In fact, after a redshift of about z=2, the angular size of objects increase with distance! Galaxies look bigger in the sky the further out we look. Here's [a graph of angular scale](_URL_0_) as a function of redshift (~distance). The units on the y-axis are kiloparsecs per arcsec." ]
What are sanctions supposed to do to Russia? Their efforts in Ukraine only have seemed to intensify in the last few months, are they supposed to have an intended effect?	[ "The Russian currency and its economy as a whole are crumbling due to the sanctions and the drop in ppb of oil. Furthermore, the sanctions can be seen as a warning shot." ]	[ "The simple answer is to ask another question: what would you allow through this firewall and what would you block? A firewall isn't automatic and it isn't magic. You can't get a firewall which blocks \"bad stuff\". It works on rules. You tell it what to block and what to let through. China has made one which block...
What is actually happening when I pour salt on a slug?	[ "It dehydrates, as the salt pulls all the water out of it, resulting in death. Think of how you preserve meats or prepare raw salmon, or prepare some cabbages; salt extracts water." ]	[ "Why not look at this as an opportunity to do a bit of science yourself? I can't think of an easier experiment to set up." ]
Why does the History Channel not show more historical programming?	[ "Remember when MTV used to show music videos instead of reality tv? Remember when the SyFy (Nee SciFi) network showed science fiction shows instead of professional wrestling? Remember when TLC (The Learning Channel) showed actual documentary type shows? (Insert obligatory \"Pepperidge Farm remembers meme here.\") T...	[ "To put simply, infrastructure costs and up keeping requires a huge amount of money. Which cannot be covered by advertisements ." ]
Why can fibre optic cables carry more data than copper wires?	[ "Basically, data is transmitted on copper wire by varying the electric current on the wire in an agreed upon manner. To transmit data faster, the current in the wire needs to change more quickly. [Capacitance](_URL_1_) between the wire and other conductors will resist changes in the electric charge on the wire whil...	[ "Lets say that you are drinking juice from a cup with one straw, you are getting the juice into your mouth but now you try two straws, you are getting more juice in less time in you mouth, you try three, it is faster ect. the same goes with 802.11n g b a. they each send more information at one given time to your co...
Why don't we have vaccines against bacteria?	[ "We actually do have vaccines against bacteria. For example we have a vaccine against the bacterial disease typhoid that is made of \"attenuated\" (think \"sick\", \"weak\", or otherwise non-pathogenic) bacteria. Some bacterial diseases aren't directly a result of the bacteria being there, it's a result of toxic c...	[ "You missed an outbreak of Measles, which hasn't really existed in the United States for about 30 years." ]
How do independent artists on sites like Deviant Art get around licensing costs when drawing or reimagining pop culture figures?	[ "It's because of [Fair Use](_URL_0_). > Fair use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work. In United States copyright law and the Copyright Act 1987 of Malaysia, fair use is a doctrine that permits limited use of copyrighted material without acq...	[ "The same is true of literally any product in the world. For example, when you buy groceries, you don't buy from farmers do you? You buy from a store, that buys from a distributor, that buys from farmers. The farmer sells in bulk to the distributor who sells in less bulk to the store who sells in single units to yo...
Why would the NFL blackout playoff games if the game isn't sold out?	[ "It's an archaic rule. When the NFL first went on TV, every game was blacked out in the local area to make sure local fans went to the game instead of staying home. However, in 1972 the cellar-dweller Redskins made the playoffs, but President Nixon and other DC politicians couldn't watch the games. The next year Co...	[ "Exposure. The pictures you mention where the space is black are usually taken to illustrate objects other than the stars, such as the ISS, the day-side of the Earth, or the Moon. Compared to those, the stars are very, very dim, and the exposure setting of the camera results in them not showing up on the pictur...
why do many people say socialism us bad?	[ "While they are many advantages to socialism i will list some disadvantages 1. Higher Taxes to fund the governments actions 2. Decreased motivation for the poor to work hard, get an education and innovate since they are guaranteed a minimum standard of living 3. Big Government - Government has more power, some peop...	[ "This CGP Grey video does a really good job of explaining it all. _URL_3_" ]
If congressional approval is at an all time low of 9%, how do they still have their jobs?	[ "Elections are not frequent enough, and recalls are too difficult. There are no better replacements. People typically give their own representatives they vote for positive approval." ]	[ "Because critics are full of shit. Most of the art world for example called Jackson Pollock \"Jack the Dripper\" until a wealthy hotel magnate bough one of his works and put it in the lobby. Then Pollock was a genius. Critics hate to be on the wrong side of history so they never have an issue it seems changing thei...
What makes a material sticky?	[ "The general answer to this would be adhesion (when two dissimilar material stick together). There are however many different ways in which adhesion could exist. For example two materials could slightly dissolve into one another and basically weld to each other, or it may result from electrostatic interactions, or ...	[ "When you step out of bath the water will stick together and fall off you, but when you're taking a shower, the water drops will stay on your body." ]
When did animosity between the U.S and England end for the most part?	[ "You might be interested in [this](_URL_0_) section of our Popular Questions page." ]	[ "Hi there! This is a reminder to potential respondents to this question that we have the [no current event rule](_URL_0_) in effect that in order to discourage off-topic discussions of current events confines questions, answers and all other comments to events that happened 20 years ago or more, inclusively (e.g. 1...
how do master keys work? How can a door have a unique lock yet also unlock with a master key?	[ "This has been answered before, but briefly, in the case of cylinder locks, instead of the pins only being in two halves, they're in three pieces. One arrangement works with the master key and is present in all locks, the other arrangement differs from lock to lock." ]	[ "You're thinking of the two clocks as ticking like this: \|---\|---\|---\|---\|---\| \|----\|----\|----\|----\| Both in the same \"direction\", with one ticking slow, and, therefore, necessarily, one ticking fast. But relatively-moving clocks in special relativity don't tick like that. They tick along different \"directio...
The story of the Kingdom Hearts series	[ "Kingdom Hearts has a ridiculously convoluted story. There's a video [here](_URL_0_) that explains the timeline of all the games and how they interact." ]	[ "A big one is, well, most of the bible. Was there a united monarchy? If so, what did it look like? Is there something behind the Exodus narrative, or is it a myth to give the Israelites a history separate from the other Canaanite groups?" ]
Do animals suffer from disorders or phobias such as claustrophobia?	[ "yes, though it's very difficult to recognize, diagnose or verify that what they are experiencing is the same as what humans do. dogs specifically are treated for anxiety, ptsd, depression and other similar problems. again, there's little concrete proof that they are experiencing the same things in the same way, bu...	[ "Because they recognize things that are not a threat, and they don't recognize people. Think of how comfortable you are around airplanes and helicopters, but what if an alien spaceship came along." ]
why does your face get red when you become flustered?	[ "When you become flustered you get more adrenaline. That means a faster heart rate. That means more blood isgoing through your body fasterer. Making your skin redish due to swelling. [7]" ]	[ "It's just one of the things we simply don't know. A known thing is that rapid temperature changes can trigger a vasovagal response. Also, holding ice behind the ear can be seen as a type of cold pressor test, a test that actively targets the sympathetic nervous system. Since the vagus nerve predominantly consists ...
Why are diners normally furbished in a 50's style and not like any from the other 80 years they've been around?	[ "Does anyone know if diners in the 60s - 80s were also decked out in 50s style? (I can remember the 90s, plus, 20 year rule). Did diners just get \"stuck\" at some point in the 50s and never change?" ]	[ "That's the time span over which the material was produced. In software you would see that if version 1.0 was written in 2000 and the most recent version or update was written in 2015." ]
How accurate is pop culture's portrayal of Native Americans as "one with nature"	[ "A bit of both. There was a lower permanent population density before white settlement which is an important factor. However, historians have shown that many tribes did not have the same consumption and land use beliefs and behaviors as Europeans. Each tribe had its own practices as well. Additionally, there is the...	[ "I would recommend reading historian D. C.A. Hillman's book,The Chemical Muse: Drug Use and the Roots of Western Civilization, in which he provides numerous primary sources and historical accounts of physicians doing things like prescribing opium, sedatives, and narcotics. His historical hypothesis (albeit a far...
How does wireless internet work?	[ "Basically, much like with a wired connection, where your data is transmitted through a medium (usually copper or fiber if you're lucky), wireless internet works by sending/receiving radio waves at a certain frequency (usually 2.4Ghz or 5.0Ghz) to and from your wireless router and the wireless card located inside y...	[ "\"magic\". This question is repeatedly asked. You need to ask more specific questions as there are a lot of things to answer." ]
Why is the jaw so sensitive to knockouts when fighting ?	[ "You knock someone out by making their head shake violently. Easiest way to do this from the front is to hit it in the jaw, which protrudes a bit and can cause the head to rotate a bit as it snaps back, or in the temple which shakes the head side to side very rapidly. The chin isn't the weak spot, just sticks out ...	[ "You said it... instinctively. As to how that came to be? Evolution. Animals which attacked weak points on their prey or predators were more successful, bred more, and they're the ancestors of the animals we know today. Evolution is an arms race, and having an advantage means your genes get to keep going." ]
What levels of organization does a bacteriophage contain? Is it considered a cell? An organism?	[ "> Is it considered a cell? An organism? It doesn't meet the usual definition of a cell (and thus an organism). It also doesn't have cytoplasm, the bacteria/archea it injects its DNA/RNA into does. As for levels of organization, it has a number of things. It varies a bit depending on which class you're looking at. ...	[ "Yes, there are a few in the pipelines, the oldest research is around phage, or phage technology. This was started in Russia and according to wikipedia is was researched and still is from as far back as 1922, I remember reading about in the 90's. Still haven't heard of anything commercial though - _URL_0_ There are...
Why do feel a lot of emotions in our stomach?	[ "Most of the neurotransmitters that travel throughought the nervous system/body are made in and reside in the stomach. Neurotransmitters make us feel things. Certain ones make us feel good, bad, anxoius, nervous, itchy, happy, sad, pain.... so on and so on... (examples of neurotransmitters are serotonin, dopamine, ...	[ "I am by no way at all a scientist or veterinarian but I have been working with dogs for over a decade. I spent a lot of time as a dog handler is a large off leash facility and the first thing I taught myself was to leave everything at the door before I went in. If something was happening in my personal life or my ...
Why are Youtube comments typically the worst comments ever? Maybe it's just me, but they always seem off topic or just completely false.	[ "the comment section has been fucked up for a while. as you've probably noticed, you can downvote comments but this feature hasn't worked for at least a year. top comments also don't get featured for the amount of upvotes they get, though while it is a factor, the top comments get ranked on how 'hot' it is through ...	[ "It's not that a lot of primes are like that, it's that those are the primes that are easiest to find. Checking that an arbitrary number isn't prime is pretty slow, for sufficiently big numbers (like that one), but for certain classes of numbers, there are shortcuts available (and, in particular, you can pick certa...
What determines the tempratures at which substances change state?	[ "In a gas, the thermal motion of molecules is fast enough to overcome the intermolecular forces that you have in condensed matter (= liquids and solids). Therefore, the stronger these forces are, the higher the boiling point of the substance. Noble gases have extremely weak interatomic forces because they have comp...	[ "[Phases of Ice](_URL_0_) You can get different forms of ice above 100C but pressures would need to be very high." ]
Today, people struggle with Opium/Opiate addiction, yet Opium was used commonly throughout Rome and China. Did those people struggle less with addiction? Why/How?	[ "Those people struggled just as much as we do in modernity. Why do you think they struggled less?" ]	[ "First off there's a wide variety of modern concrete. The portland cement part of concrete is the same but what you add to it and the water/cement ratio can vary quite a bit depending on what properties you want out of your concrete. Roman concrete had volcanic ash added to it. That's similar to modern concrete tha...
what exactly makes us warm blooded?	[ "Maintaining a near constant temperature is known as homeostasis, and doing so is known as thermoregulation. While the main \"controller\" of thermoregulation in the brain is the preoptic anterior hypothalamus, there are a number of mechanisms that actually cause changes in temperature. Sweating, vasodilatio...	[ "Roughly, blood runs through two circuits : it's called double circulation. The right ventricle pumps non-oxygenated blood to the lungs, and the left ventricle pumps the oxygenated blood into the body. The left ventricle needs more powerful muscles to do that, which makes the heart shift towards left." ]
What do we know about the origins and history of the Abrahamic religions?	[ "I haven't read Dawkins book, but it's worth bearing in mind that from what I have come across of his concept that religious features amount to cultural \"genes\" of, as you say \"of self-replicating traits to survive through the ages\" simply has no bearing whatsoever on the development of Islam or Islamic law. Lo...	[ "This is a pretty common question here; here's some links from the FAQ: _URL_2_ _URL_4_ and a few others that have been posted over the years: _URL_3_ _URL_1_ _URL_0_ Most posts agree that it is largely a post-war pop phenomenon with fairly little evidence to support it." ]
what's the difference between 3-in-1 shampoo and mixing equal parts shampoo conditioner and body wash yourself?	[ "I use three separate products. Since an all in one has conflicting jobs, it can't work as well. But if you aren't too picky, an all in one it will work well enough. Mixing stand alone products will be even less effective." ]	[ "Imagine you are made of genetic soup. Some people have ingredients that just don't go well together and make the soup taste bad. But that's ok, because when you have a kid, we just take some of my soup and some of my wife's soup and pour it in together. So even though my soup has some bad ingredients, her ingredie...
My friend told me he thinks microwaved water kills plants. I call on you all to help me convince him that microwaves are perfectly safe.	[ "It's complete hogwash. Nothing happens when you microwave (pure) water other than it gets warmer. There's no way of telling, even in theory, whether or not some quantity of water has been microwaved in the past or not. I'm afraid you won't find any articles in Scientific American, because they don't usually bothe...	[ "The nature of radiation is such that its effects are random. This is part of the reason that it can be so harmful. Since the damage caused varies so much, it is difficult to counteract. Radiation causes harm by mutating DNA. Most mutations either have no effect or just cause a cell to die, but some cause runaway r...
Is it normal for members of the American government to sue the president?	[ "It's not exactly what I'd call common, but it's not impossible. You can basically sue anyone at any time for anything. This doesn't mean that the judge won't just throw your case out of court though. I'm fairly certain that's what's going to happen here. Nothing will be accomplished except for a waste of time for...	[ "I once cleaned the offices of a local law firm, fairly successful, but quite small. In one room was their records. Apparently they had a case against Coca Cola. There were well over 100 3\" binders FULL of paperwork dedicated to this ONE case. I am talking bookshelves FULL of binders labeled \"X versus Coca Cola\"...
Why don't you get infected when you wipe too hard and there's blood on the toilet paper?	[ "About 10% of the time you have a bowel movement and often when you floss your teeth you get a transient bacteraemia, i.e. bacteria circulating in your blood. Your immune system manages to clear them which is why we don't all die of sepsis." ]	[ "This video created by Vsauce 3 (Jake Roper) does a very good job explaining this: _URL_1_ I hope this answers your question. He also did another video on a simmilar line of - could you survive: _URL_0_" ]
if Earth is safe by asteroids missing us all of the time, why is the moon covered in craters?	[ "The atmosphere comments are true for sure. But also consider that the Earth surface has been hit by many millions of asteroids. You see them on the moon because there is no weather/water/vegitation to erode the surface and no plate tectonics to recycle the crust. The Earth has all of these and is constantly recycl...	[ "What you're looking at is Half Dome in Yosemite National Park in California. The geologic name for this is an arête and forms due to glacial processes. The orientation of this image is kind of an optical illusion. Looking at it from [a different angle](_URL_0_), you can see that it's more of a linear ridge than a ...
What was the contemporary reaction to the Tunguska event?	[ "Here [are some eyewitness accounts](_URL_0_). The website is in Russian but Google Translate does a decent job of translating." ]	[ "Hi, I've approved the post, but just a note to you and potential respondents: this subreddit has a 20-year rule against discussing current events, so any answers will have to cut off at 1997. If you're looking for answers that can include 1998-2012, do consider x-posting elsewhere, eg. a foreign affairs sub like /...
Why do teachers/professors and others ridicule Wikipedia as a lousy source, yet it almost always contains detailed and accurate info?	[ "Because everyone is on equal footing, regardless of actual knowledge and expertise. Yes, the experts tend to be the ones who care most about the articles and write and defend them, but it's not always the case. Wikipedia can have definite biases. Take the page on [marijuana](_URL_0_) (cannabis). The hivemind men...	[ "The guidelines state that although we shouldn't argue about what is considered an acceptable answer, we should try to have elementary school answers. In my opinion, your top-level post should definitely be an elementary style answer. More detail should then be added in a reply, if you're going to add it at all. ...
Why does it take thousands of gallons of water to make a single pound of beef?	[ "Well according to this source, it takes 150 gallons of water to make one pound of corn. Given that a cow can eat thousands of pounds per month, this water cost can add up very fast. Other than the feed, I don't think cows require much water, but I could be wrong. _URL_0_" ]	[ "They did not think about this prior to launch. Later, when curiosity was already on Mars, they started thinking that weather could carry microbes for a couple of km and started to get worried. Curiosity's path was adjusted to avoid slopes that are thought to have liquid water intermittently. _URL_0_ > experts at ...
What happens when you eat a deficit of junk food calories every day?	[ "Junk food is not some homogeneous thing. What are you eating? You'll lose weight, regardless." ]	[ "It minimizes the ability of your curves to cast shadows on other parts of the body, and falls off more easily into the lighting behind you. By providing fewer references, our eyes lose visual cues as to how \"wide\" the subject is. Edit: In addition, it creates an optical 'void' that appears to pull the edges in a...
Why is our food hole the same as our air hole? Doesn't it only result in things like choking?	[ "Evolution co-opts structures that are already available to it for new purposes. Not everything about our makeup is there because it is the best possible design, but often because it was a functional design that was easier to stumble onto through a series of gradual accidents than a better but more complex design w...	[ "Words that often appear together are called \"collocations\", and it's simply the way we've learned them. We tend to process them as indivisible units -- phrases, rather than separate words. For example, when we say \"apples and oranges\", we're not thinking of two different kinds of fruit and then putting them in...
How does the polarized light that reflects off of the screen in a 3D movie theater retain its polarity?	[ "Also worth noting that some 3D Film projections aren't vertically/horizontally polarised, but rather circularly polarised in different directions (otherwise the effect wouldn't work if you turned your head)." ]	[ "Prologic works by flipping the phase on the audio meant for the rear channel. The decoder works like this: * any audio this is present on both the left and right channel and is in phase, is routed to the center speaker. * any audio that is present on both the left and right channel but is out of phase is routed ...
Embryonic Stem Cell Research	[ "When a human foetus (sorry, british) is conceived, (sperm meets egg, and they get together and start multiplying) those first cells are called stem cells. They are important because they are all the same- they haven't turned into brain cells, blood cells or anything else yet. They will end up replicating other c...	[ "We are already doing it! Engineered proteins have been made on an industrial scale for ~ 30 years in the biopharma industry. The first recombinant protein treatment was approved by the fda in 1982 _URL_0_" ]
In people with schizophrenia, does the brain only create the feeling of seeing something that isn't there, or does it create an actual 3D image of it and insert it to the picture the person is seeing?	[ "Hallucination, which by the way may affect all senses, are pretty much real and experienced by the person as real. We think what happens is basically your inner monologue manifesting as external stimulus. Basically, when you're thinking to yourself, you're engaging various parts of your brain that represent...	[ "I'd like to add this. In WWII they retrofitted some Spitfire airplanes with up to 5 cameras that used this exact same principal to take 3D areal recon photos of Europe. The cameras were aligned just right (and pilots trained just right) take take photos that could be put under a special viewing device bringing the...
Correlation does not imply causation	[ "A correlation in statistics becomes a causation when you can find a theory that accurately describes a link between the two. Ice-cream sales and drownings are correlated but there is no causation. The thing that causes the correlation is that people swim more and eat more ice-cream in summer. Drinking and driving ...	[ "I believe that this answers your question and explains the fallacy in this comic quite nicely: _URL_0_" ]
Why do people wake up just mere minutes or even seconds before their alarm goes off?	[ "Others have mentioned the circadian rhythm which is most of it, but other factor is more mundane: Confirmation Bias. When you wake up just minutes before your alarm, that's remarkable, and so you think about it and remember it. But when your alarm wakes you up, that's just another morning and there's nothing spec...	[ "Simply put for the same reason drinking water when you're not thirsty isn't as refreshing as when you're REALLY thirsty. Anticipating the bodies' needs doesn't trigger the same reward responses in the brain as fulfilling a need that is already present. Your muscles don't NEED to stretch right now, so you can't ant...
How far up in the sky can an insect fly?	[ "> In 2008, a colony of bumble bees was discovered on Mount Everest at more than 5,600 metres above sea level, the highest known altitude for an insect. In subsequent tests some of the bees were still able to fly in a flight chamber which recreated the thinner air of 9,000 metres. [ Organisms at high altitude]( _UR...	[ "It might just be your perception: you notice them buzzing around your face (the part of you with all the sensory organs) more than you notice them buzzing around your leg." ]
Did Genghis Khan really order his men to behead 1.75 million people in the city of Nishapur?	[ "Grisly as it is, victorious armies putting cities to the torch for much of history isn't unheard of. Empires like the Assyrians exacted overwhelmingly brutal retribution on rebellious cities or territories to scare others into submission, and even groups as late as the Wermacht in WWII would use mass reprisal to t...	[ "when people die of fentanyl being cut into heroin, the consumers think that \"this guy died doing it, so the dealers heroin must be crazy.\" This way the dealer sells more and more money is made. Its an unethical and immoral technique but they donts cares." ]
Your immune system causes symptoms like fever, swelling, etc, when fighting an infection. I usually get more mild symptoms than my wife when we both get sick. Does this mean my immune system is weaker or stronger?	[ "Great question, but it's complicated, because different infections trigger the immune system to different amounts. Sometimes, what kills a person isn't the infection itself, but the immune response to that infection. In those cases, it's better to have a slightly weaker immune response; the response will still be ...	[ "It's not that healing happens faster at night, but it happens in a more efficient manner. Your body does a full maintenance at night repairing many tissues, regulating hormones, as well as the immune system gaining strength during sleeping hours. There have been [studies](_URL_0_) linking decreased sleep to decrea...
(Biology) If AIDS infected blood was injected into an orange, would the AIDS survive in the orange and could you get AIDS from eating the orange?	[ "HIV can survive only a few hours outside the body, and that is in a favorable environment. The virus is incredibly fragile, and cannot survive long in acidic environments, including inside an orange. Additionally, it is almost impossible to have AIDS orally transmitted unless there exists an open wound in the mou...	[ "Kind of a compound answer. I'm assuming you mean you just brushed your teeth and now are about to chug a glass of OJ. Toothpaste is an emulsion and contains surfactants. The surfactants allow the toothpaste to become foamy when some water/spit is mixed in. Those surfactants effect one particular taste sensor, swee...
a rock hitting a large pipe making a laser noise	[ "The real question here is why George Lucas went with \"rocks on hollow metal pipe\" for the sound of plasma weapons in his movies. Lasers don't make a sound." ]	[ "Edited: I have heard two things... * Rockets sent up to record various aspects of the test. * Vertical smoke flares which are used to observe the shockwave Edit 2: [Seems like it is a combination of the two](_URL_0_): > Sounding rockets or smoke flares may be launched just before a device explodes so that their v...
Do we currently have any way to detect planets whose orbits do not intersect the light between it's host star and Earth?	[ "Unless they are perfectly perpendicular to our line of sight in their orbits, they will still cause a small periodic radial velocity shift, and could be detected through the star's spectrum. They could also be imaged directly, but that is difficult." ]	[ "Absolutely. That's how we have radio, infrared, UV, etc telescopes. The coating you use to optimally reflect the wavelength you're interested in changes, but the physics is the same. For example, the upcoming [James Webb Space Telescope](_URL_1_) has gold coated mirrors, because gold optimally reflects the infrare...
What does the red cross mean next to the points in a reddit comment?	[ "It means that voting on the comment was controversial, meaning there were both a good number of upvotes as well as downvotes to arrive at that score." ]	[ "All the formatting instructions are held in a seperate file so that each page can have the same look and feel. These files are called cascading style sheets (.css) and if they fail to load for any reason, it causes the site to revert to a very basic plain text look" ]
Why are some animals like birds and reptiles born from eggs while most mammals are not?	[ "Everyone is born in an egg. Just some species keep the eggs inside mommy till they hatch and some pop the egg out early to hatch in the nest." ]	[ "There was a genetic mutation about 8,000 years ago that allowed humans to keep consuming milk into adulthood. It made the domestication of dairy cows possible, and made the populations who had the mutation a lot more survivable in harsh climates. Later, into modern times, that mutation led to a lot of very delic...
Benzene is a known carcinogen. Why is it that by adding just a methyl group, toluene is not carcinogenic?	[ "The big difference is metabolism. Benzene is metabolized, to a small extent, to a reactive epoxide that can alkylate DNA (likely via the sort of intercalation mentioned by u/croutonicus). Toluene, though, is very easily oxidized on its methyl group to benzoic acid, which is excreted harmlessly through several rout...	[ "If you drink coffee every day to wake yourself up in the morning, you will eventually become addicted. How would this contribute to you becoming addicted to alcohol, tobacco or methamphetamines? They're completely different drugs with different effects, different feelings and, most importantly, different chemistry...
Hitler, Stalin, Trotsky, Tito and Freud apparently all lived within a few miles of each other in Vienna in 1913. Why was this and how much of a coincidence is it?	[ "There is a very good answer to this by /u/commiespaceinvader from about a year ago: [Is it true that Hitler, Stalin, Trotsky, Tito, Freud, and Archduke Franz Ferdinand were all living in Vienna in the summer of 1913?](_URL_0_)" ]	[ "Karachi (largest city in Pakistan) is currently experiencing some large problems; both in crime, and politically. This is in part due to [Altaf Hussain](_URL_0_) who is the founder and leader of the [Muttahida Quami Movement](_URL_1_) - a political party in pakistan based in the city of Karachi. The problems surro...
If multiple objects are generating sound waves with the same amplitude, wave length, frequency, period, etc. would they sound exactly the same if one was coming from a guitar and the other a saxophone?	[ "The sound of an instrument is a function of a lot of factors: in built harmonics, resonance etc. However the shape of the waveform is critical in producing a characteristic sound. It sounds like you're assuming a sinusoidal wave form in your question. They generate a pure 'tone'. Play with audacity and you can g...	[ "Cell towers do in fact transmit the same information to every cellphone in range. However, the data is encrypted, so that only the correct phone can understand the information meant for that particular phone. Each phone gets a time slot where the data sent is for that phone, and each phone gets a time slot where ...
Why do perfectly symmetrical cars in video games veer left/right when they are on flat surfaces?	[ "I could be dead wrong on this when it comes to video game makers' intentions, but IRL most cars have less than perfect steering unless you just drove a brand new one off the lot. They'll slowly but surely veer off to either the left or right even on a perfectly flat roadway." ]	[ "Depends on the way the online stuff is done. It's either server side calculations, where you pressing the button sends a message to the server along the lines of \"hey he pressed shoot, tell me what happened please\" or client side which is \"hey he pressed a button so I figure the bullet went here and hit that gu...
How did the culture of viking settlements in Britain differ from those in Scandinavia? How rapidly did the differences evolve?	[ "One major part of viking colonization was their ability and propensity of adapting quickly to the places they settle (taking local wives, learning the local language, etc). So vikings who settled in Britannia often adapted to the local customs, mixing their own culture with that of the place they were settling. T...	[ "Most people copy ideas. If the tribe A comes up with a good idea, then tribe B next door will copy it. Or tribe A's good idea may make it powerful enough to conquer tribe B and force them to adopt their idea. Isolated communities may not be exposed to outsiders' ideas (like modern technology) so they don't copy th...
How did the evolution from gills to lungs occur?	[ "lungs actually evolved from a sack attached to the esophagus of fish that allowed them to get air from the atmosphere when the oxygen content of the water was low. The thin, blood vessel filled membrane of the \"sack\" allowed oxygen to diffuse into the bloodstream, and over many generations as the need to get oxy...	[ "If you're really asking 'why', no one knows. Luck. Chance. Possibly something else entirely. It's a deeply philosophical question. If you're asking how, tools. Tools made the difference. Humans were lucky enough to learn to use tools, to develop fire. That was what pushed us into the dominant position." ]
Entire canadian city burns yet no international aid	[ "This just happened, like literally just happened. It takes time for aid to be raised and distributed. Additionally there will probably not be much international aid. Canada is a fairly wealthy country and plenty capable of taking care of its own problems. Most times there are large scale aid campaigns it is when t...	[ "This is quite simple actually if you study a bit you will realize Target is closing Canadian stores. The stores opening near you are in the U.S. Target's sales in Canada are bad. Target's sales in America are doing great." ]
How can Batman possibly stand off with Superman as an equal?	[ "This is why I never liked Superman. There are three basic plans to defeat superman: 1) Be an evil Superman 2) ridiculously suboptimal choices by Superman 3) Kryptonite It's really difficult to fashion multiple compelling stories out of those options. My guess would be that the Batman script calls for a little of 2...	[ "The difference in speed between the two surfaces is in the thousands of km/h. The test could not occur." ]
Why haven't we been able to develop drugs that don't harm us?	[ "Drugs only have effects by making our bodies release or decrease chemicals that we already use on a daily basis. The problem is when you start messing with our natural systems it causes them to change. So for MDMA and cocaine they cause massive releases of chemicals in our brain that give us the stimulated euphor...	[ "because there are always going to be people that will be looking out for #1 (aka themselves). distribution is also a big challenge. like aid was sent to africa, it was all taken by the local warlords. short of sending an army platoon to protect and distribute the food, it will be taken by whoever is \"in power\" i...
What's the point (if there is one at all) of disease "awareness"?	[ "How much money do you suppose gets spent on curing diseases that aren't widely known? What is the advantage to a politician for allocating budget money for grants to pay for research on a disease that nobody knows about?" ]	[ "It's a 'win-win' scenario for both schools. The 'powerhouse' team, like for instance Alabama or Clemson, get an easy win because they're able to use their legacy to recruit better players. The 'unknown' college gets 'free' publicity for playing a well-known school, and if they happen to pull off an upset, then it'...
Why do millionaire athletes use personal financial advisers instead of using a bank?	[ "They're not the same service. A financial advisor gives you- I'm sorry- financial advice, about how much of your money to put in the bank, how much to invest in stocks, what kind of insurance you should buy, etc, so that you'll earn the most interest (broadly understood), while still having enough money available ...	[ "to build publicity. reporters aren't following them all the time. in order to get reporters to show up, the person has to announce that they're going to make a major announcement that'll make news." ]
Why is it considered "childish" to like ketchup and put it on a variety of food?	[ "It's a sauce used to cover the taste of the food. Instead of learning to like various grown up foods you avoid it by making them all taste the same" ]	[ "life expectancy and social expectations have pushed back the age of considered maturity in the early 1900's, women would get married before they were 18, and already have kids by then. that's a pretty big responsibility. not to mention that there were wars that young men were drafted into. nowadays, people don't u...
Why is it so hard to build a bipedal robot?	[ "The biomechanics for bipedalism are very complex. Humans have numerous tiny muscles that exist solely to provide balance and leverage during walking, running and balancing. Replicating the mechanics of a knee joint can be pretty easy. But if it can’t be replicated, say the extensor mechanism that interacts with th...	[ "The crushing pressures in the ocean among other things. And how would you remotely operate it? with miles of umbilical cabling or with radio that can only penetrate so far?" ]
Why can’t people survive upside down but babies can while in the womb?	[ "It’s like when you’re swimming. I googled it to get a better definition than I could’ve come up with: In the human body, vasoconstriction is what has to generate this coutneracting pressure to keep the blood moving. Underwater, the water does it for you. In short, since the water around you weighs so much more tha...	[ "When light moves from one medium to another, it refracts (distorts). The eye evolved underwater, so it evolved to have fluid inside it so light would move from the water into the eye without refraction. Your eyes have adapted to compensate for the refraction that happens when light goes from the air to the fluid i...
Why has the Higgs Boson been so hard to find (supposing it exists)?	[ "mostly because its decay seems to happen into particles that have a lot of background. So it's a very small signal in a sea of noise." ]	[ "We look at galaxies and measure how much visible mass there is. We notice that hmm, there simply isn't enough mass in those stars to hold that galaxy together with gravity. It would need at least 3 times that mass to hold itself together, yet, it seems to be fine. We deduce, then, that there is some form of matter...
why is cocaine worse than a energy drink from a health standpoint?	[ "Cocaine triggers the release of the adrenaline-like hormone norepinephrine, which causes increased heart rate and blood pressure, and narrowing of blood vessels. Since coronary arteries constrict during cocaine usage, the heart has to work extra hard to pump oxygen and blood. If blood flow to the heart is complete...	[ "Damage potential is much, much greater too. Both malicious and accidental." ]
how can the radius of the observable universe be 46 billion light years while the universe itself is only 13 billion years old?	[ "The universe itself is expanding still and doing so faster than the speed of light. Where nothing inside the universe can move faster than the speed of light, the expansion of it can. (In my very limited understanding) Where something was observed at point A and now at point B they can tell that the expansion is X...	[ "The formula for the relativistic Doppler shift for EM radiation is, from wikipedia: f = F sqrt( (1-B)/(1+B) ) where F is the frequency in the frame of the source and f is the frequency in the frame of an observer moving relative to the source with velocity B = v/c. For B < 0 the observer is moving towards the sour...
Why do we have moles?	[ "I think OP is referring to a nevus, the official name for a mole. If you could look at your skin under a microscope, you would see several different types of cells under the surface. One of these cell types is a melanocyte. These cells are responsible for producing melanin, the brownish pigment that gives skin col...	[ "[_URL_1_](_URL_0_) says it was [evolved to protect us from viruses.](_URL_2_) edit: added a better source" ]
Did the Roman empire ever control the city that is present day Prague?	[ "Nope. In Europe the borders of the Roman Empire were largely defined as west of the Rhine river and south of the Danube river, the only real exception to this being the temporary province of Dacia and Moecia in modern Romania. Prague is north of the Danube and not in Dacia." ]	[ "So, I don't know if you know this, but Blackstone did just what you are suggesting. After the housing crash of 2009, they went out and bought up homes in different cities. They put them all under the umbrella of a REIT (real estate investment trust) called \"Invitation Homes\" and then spun it out in an IPO a few...
How does toothpaste work?	[ "I asked my dentist what differentiates toothpaste brands when I was a kid so he pulled out a few different ones and started going over the ingredients. Aside from color, preservatives, flavor etc. there were a few active ingredients: 1) A small amount of soap. This helps dissolve fats. 2) Hydrated silica. This act...	[ "This is a very common question. You can use search to find [all the other really good answers](_URL_0_ ). This is instant, and faster than ust typing in your question every time. It's a way of cheating elections. Read the others, and then ask a more specific question." ]
How much legal authority do HOA (Homeowner Associations) actually have?	[ "HOAs exist, almost completely, because people choose to sign into them. Their authority derives from that. The retired Marine in question agreed to have his home governed by an association of his neighbors. That's an agreement he entered into willingly. His recourse is to try to change the association's mind." ]	[ "You can't get a straight answer because it is hogwash. They are removing nothing from the body that isn't normally getting removed by the liver and other parts of the digestive system." ]
What is physically happening when you have a stuffy nose? Why does your nose continue to feel stuffy and blocked even after blowing your nose?	[ "It stays blocked because the lining of your sinuses actually swells up, making your sinuses constrict. The more you blow your nose, the more you irritate that lining, thus leading your sinuses to swell more and further exacerbating your stuffy nose." ]	[ "Yer not alone in askin', and kind strangers have explained: 1. [ELI5: what makes pop rocks/popping candy 'pop'? ](_URL_2_) ^(_1 comment_) 1. [ELI5: What makes Pop Rocks pop? ](_URL_0_) ^(_4 comments_) 1. [[ELI5] Why do pop rocks pop in your mouth? ](_URL_1_) ^(_18 comments_)" ]
Why is 3-ply bathroom paper standard in Europe but not in North America?	[ "I wonder this too, because 3-ply is apparently also the standard in Australia, but it's not even available here in the United States." ]	[ "They did a few years back. It was called Olestra, and it was supposed to change the way we eat (or so they claimed). Basically, the stuff was a fat-substitute that the body simply wasn't able to absorb or digest, so it was just passed through the body. Unfortunately, a problem arose with the stuff because you were...
Why, and what makes humans have such a good, natural sense of trajectory?	[ "A lot of primates are good at this, and infamously so in the case of feces-flinging monkeys. It probably relates to adaptations for living in trees, and could easily be an accidental byproduct of those. We have grasping limbs, binocular vision, etc, which are very useful for judging distances and throwing. In the...	[ "Math. After we were able to accurately monitor and figure out the body's course it was simply (not that simple) math and physics that told us where it would go. (EX: at day 12 month 5 yr 1981 it was here, on day 27 3rd month yr 1984 it was here, insert big math problem, and we now know that on day 1 month 1 yr 198...
If electromagnetic waves are massless, why I do I get a value for light's mass using De Broglie's wavelength formula? If so, does violet light have more mass than red light? (More explained in description)	[ "The problem here is attempting to substitute 'p=mv' into the equation for the De Broglie Wavlength. The equation 'p=mv' is a relationship that only applies to objects with a nonzero rest mass that are moving slowly compared to the speed of light. Since photons are massless, using any equation for momentum that inv...	[ "When all three colors of cones are excited equally, you see that as white. If you added some extra red light, you would see it as light red. If you then added extra green and blue to balance it out, it would excite all the cones equally again, and it would look like brighter white. If you added more light at the r...
Could southern hemisphere countries get something similar to the polar vortex from Antarctica?	[ "The main reason for the Antarctic vortex is the temperature difference between the land and the ocean. The ocean won't fall below about 3C while the land can get down to -50C or lower. This causes enormous updrafts along the edge which in turn cause the vortex. While I am not sure, the temperature differential bet...	[ "2 main reasons: Latitude: most of Australia is situated in the [subtropical ridge](_URL_0_) where there is generally high air pressure and low rainfall. Lack of Mountains: Australia is quite flat. Tall mountain ranges cause clouds to form into [rain](_URL_1_)" ]
If hot air rises, why does it get colder the farther up you go?	[ "Imagine air temperature as the speed of the air molecules. The air feels warmer the more often you are hit by a molecule. The farther up you go, the less airpressure there is, which means there are less air molecules in a certain volume. That's why you get hit less often and that's why it is colder." ]	[ "Particals spread out over time (thats why if I sprayed something in one corner, not everyone would smell it at the same time) so over a longer period, the particals move further and further away from the point of origin, and the particals spread thinner and thinner, to the point that you dont notice it anymore." ]
why does the scanned version of my art look worse than a photo?	[ "Are you comparing them on the same screen (not just computer screen vs phone screen)? If not, the difference in calibration can be huge. Even if they are being viewed on the same display, the setup of the scanner's color management and the phone camera's color accuracy will provide vary different results." ]	[ "Well for starters you don't get more than one take, if you're performing live and you miss a note you can't just call redo. You are also standing on stage having the sound blasting from giant speakers, not ins a sound tight area with special equipment to pick up and fine tune every little bit of sound. And of cour...
What's going on chemically when someone feels loneliness?	[ "I think the pit of despair studies on baby monkeys showed that social animals like primates innately crave affection, and become depressed and disturbed without it. _URL_0_" ]	[ "[2-nonenal](_URL_0_) > In the April 2001 issue of the Journal of Investigative Dermatology, Shinichiro Haze, et al. published an article entitled: \"2-Nonenal, Newly Found in Human Body Odor Tends to Increase with Aging\". > In this article they reported on their work which involved the analysis of body odor com...
How does gravity effect time?	[ "You've heard of how traveling faster makes your \"clock\" move slower relative to someone who is moving slower than you? As you move faster through space, you move slower through time, relative to everyone else. It's the same with gravity. Being closer to something with higher \"gravitational potential\" makes you...	[ "It is much more complicated than that, and is a very active area of research. A professor at my school, David Eagleman, studies this stuff. He's a complete badass, check him out: _URL_0_ edit: one of his famous experiments involves using magnetic energy to slow the propagation of some signals in the brain, and i...
What did the ice front look like during the ice age?	[ "It would have looked like the end of modern-day glaciers. In fact, they were glaciers at the ends. In fact, we are still in the ice age today, as there are still significant parts of the earth covered by ice." ]	[ "Edit: STSCI people have [posted an explanation](_URL_4_). There's also a [youtube video](_URL_3_) which explains it around 1:45. The long and short of it is that Hubble was tracking background stars throughout those images, and its orbit around the Earth meant that the comet had noticeable parallax which cause...
Could Hitler have won WWII?	[ "Check out /r/HistoryWhatIf and you may find what you're looking for. Search for WWII and you'll find all sorts of possibilities. For this question there really are far too many variables to be able to make serious assumptions. For starters, you would have to define what victory meant for the Axis powers and where ...	[ "In 1952, Stevenson campaigned on the record of the Democratic Party since 1932. The argument was basically that it would be better to trust the legacy of the New Deal to the party that created it than to the GOP, which they called the \"Party of Hoover.\" The problem with that strategy is that it was the same one ...
Why do we get songs "stuck" in our head?	[ "Some have suggested that it causes dopamine responses. Similar brain mechanics to forms of addiction (alcoholism, smoking, drug abuse etc). _URL_0_" ]	[ "your body releases a chemical to help you fall asleep, when you wake up you are still under it's effects for a few minutes." ]
If an astronomer with a telescope traveled thousands of years into the future could he or she calculate the current year by only constellation shifts?	[ "Randall Munroe, the artist behind _URL_0_, completed an epic and award-winning project called 'Time'. At one point in the story, he [depicted a night scene](_URL_1_). Well, his audience was geeks, so within a hour or so we had determined, by the proper motion of the stars, the location of the planets in the starfi...	[ "Several reasons: * Better technology. Many chambers were detected by sonar or radar. They would send a signal through the stones and listen for irregular echoes. Today's sonar and radar imaging techniques are better than they were in the past. The equipment is more sensitive, uses different frequencies, and with d...
Why do scientists commonly say that a planet cannot support life, if we don't know what type of life we're looking for?	[ "I think Neil Tyson put it best in this video. Answered this same question for me. _URL_0_ TL;DW we are made of the most abundant chemicals in the universe with carbon being the most reactive chemical known. It makes sense that other life would also have similarities to \"known\" life due to the sheer abundance of ...	[ "Doctors know which antibiotics to prescribe because medical lab specialists perform a series of tests (eg. a serology test checks the patient's blood for antibodies against a specific strain of pathogen). Lab workers use complex but linear test schematics to narrow down what the infection could be. These tests are...
Does the human body lose more calories/day when it is suffering from fever? (Considering other activities remain same)	[ "Yes, all else being equal. The hypothalamus sets your body's temperature set point, which is the temperature it tries to maintain at steady state. To generate heat, the [tonus of the muscles](_URL_0_) will increase. If the body can't get warm enough, tonus will increase until the muscles cause shivering. The energ...	[ "Your cells have ion channels whose permeability to certain ions is influenced by temperature. By changing the permeability of the channels you change the electrochemical gradient of the cell which can easily be translated into an action potential. Really they aren't directly measuring the speed of molecules, they'...
The human brain consumes about 25% to 30% of the calories we use. Do other animals devote so much of their energy budget to their brains?	[ "Wikipedia tells me about 20% of our calorie usage is for brain metabolism. You are aware that our brains evolved to be so large only after our ancestors managed to increase their calorie intake, likely due to master of fire." ]	[ "It's called [mind-wandering](_URL_0_). It's long been thought that the [default mode network](_URL_1_) is what drives this. This network refers to a number of regions in the brain which show greater activity when people are not engaged in any active task (or are engaged in an easier relative to harder task). The i...
How did sexual reproduction come about?	[ "Bacteria have a primitive form of sexual reproduction where they extend a long sharp pillus into another bacterium and exchange DNA on a ring. This gives advantages of sharing genetic information for biological weapons and biological resistance. Later, in multicellular organisms, some cells became specialised in t...	[ "We get copies of genes from both our parents. Many really bad issues tend to only be bad if you get two bad copies, because if even one copy is fatal, then that particular illness isn't very likely to be passed on and goes extinct. So if you have two unrelated parents, and one of them has a bad copy that cause...
How are pictures of the milky way galaxy taken?	[ "Most are artists renderings based on what we know is where, being on one of the out arms of our galaxy we can take pictures looking in toward the center fairly easy, but the rest is mostly speculation based on what we know and pictures of other spiral type galaxies. Also, the color in photos of space is added afte...	[ "I’m not a scientist, so I can’t explain like you’re 5. However, it’s a combination of a few things. Space is empty, so there’s nothing to interfere with the signal, unless a satellite momentarily dips behind a planet. Basically there’s a network of satellites around Mars that pick up a signal from the ground on M...
Do powerful lasers make noise? (and some follow up questions)	[ "If the light has sufficient power (irradience W/m^2 ) then it can ionize the air. That is, the molecules in the air will break apart into molecular cores and free electrons. This is what happens when you see a lightning flash. Ionized air is very conductive -- like a wire. Ionized air is also very hot. This insta...	[ "Imagine you wanted to send a digital file to a friend of yours, but all you have is a telephone and the binary data contents of the file. You tell your friend \"when I say beep you write down 1, when I say boop, you write down 0\", and then you read the contents of the file to him over the phone \"beep beep boop ...
Got heavily into WW2 warfare. About to finish Guderian's Panzer Leader. Is there a good counterpoint?	[ "You have to be a bit careful regarding apologism with Hans von Luck as well, but his Panzer Commander is an interesting read as a counterpart to Guderian's work. He served all over Europe--Poland, France, North Africa, Russia, Italy, and back to France for Normandy and Falaise. It has more than a whiff of the \"...	[ "Hi, I have some book recommendations on my profile page here: _URL_0_ From that list I'd say these would be useful: * N.A.M. Rodger, The Wooden World: An Anatomy of the Georgian Navy: An accessible introduction to the navy of the mid-18th century, while still providing substantial detail. Establishes Rodger's ...
What stops a wooden pipe from burning when being used?	[ "Nothing stops it besides a higher heat toleration. Tobacco burns at somewhere around 500 degrees whereas a briar pipe, which is heat resistant, can handle much higher temperatures." ]	[ "I like this. However, pictures are awesome. Your pictures with the flame on the drawing board? Good stuff. The video with candle/flame? Good stuff. Your face? Great face for TV, but I don't want to see it the majority of the time. It makes the viewer lose interest over a period of time. Personally, I liked learnin...
- How can a site like Google have constant, intense web traffic and maintain near 100% uptime, but then when Star Wars tickets go online none of the theaters can handle the traffic even though they knew they'd be busy and uptime is necessary for ticket sales?	[ "Really simple. Because the ticket sites can't afford the server power and high end technicians on something that only happens once in a blue moon." ]	[ "Because if the movie came out immediately, then no one would see it in theaters and movie theaters won’t bother to show a movie no one is going to see." ]
What is the clock rate of the human brain?	[ "Traditionally computers have clock rates because they do their calculations in a synchronized manner. Meaning they do step 1, tick, step 2 ,tick, step 3, tick, etc. Human brains do not work that way, many instructions are being executed simultaneously. It's closer to a multi core processor, which have several pro...	[ "It's been several years since my last CS class, but here's what I understand it to be -- a simple memory safety check that isn't happening. Here goes. The TLS heartbeat allows one end of a secure connection to say \"I'm sending you data, please send it back to me.\" This supports up to 64KB of data, and the size a...
Did supporters of Nixon ever turn their backs on him?	[ "Not to get in the way of anyone else who wanted to answer the question in depth with good sources, but everyone's favourite Alaskan, /u/The_Alaskan, had a good response to the question: [Did Richard Nixon have apologists in the press throughout the Watergate scandal? If so, did those journalist lose credibility af...	[ "On top of the link provided by /carpenter I'd say that Intelligence played its part and much of this intelligence was linked to the Pinkerton agency. I recommend reading a quite interesting, and probably unique, book titled \"The secret war for the Union\". Relates all the intelligence efforts and sources of the A...
Can the density of a liquid be predicted?	[ "This is actually part of a pretty major field of physics! There are many methods for this. iorgfeflkd has given the simplest one, but if you want to do this more accurately you need to do a proper computer simulation. One method is called \"molecular dynamics\". In this method, each atom is a particle, and you giv...	[ "Why not actually try the experiment? Everything you need is available at your local drug store[1]. An irrigation syringe (one with a plunger) could work to help you separate the oil from the urine. Tests for cannabis don't usually measure THC, but rather a metabolite which is a bit more hydrophilic; however, that ...
Why is air resistance proportionally squared to speed?	[ "The rather hand-waving explanation is this: When you go faster, the molecules hit you harder, so there is one factor of v. But also, your path per second is longer so you go through more air, which gives another proportionality to v. Hence v^2." ]	[ "Think about things bouncing around. Imagine a box with a fan in it. Put 20 balls in ithe box. Now imagine a basket to one side just the right size for the balls. Turn on the fan. The balls jump around randomly. At some point a ball will fall into the basket. This will happen at a given rate which will depends on h...
Why do we feel angry towards something or someone before knowing why we're angry?	[ "You have subconscious reaction to some stimuli. For example, it could be psychological projection where you subconsciously deny some of your toughs or emotions. When you see someone else expressing things you don't accept in yourself, you become angry. Or it can be something else. We are not as aware of what hap...	[ "The body can get energy from two sources (well 3, but since you are a kid I'll ignore alcohol. Also, I don't think that's stored in the body for any length of time anyway) fat and sugar. When you eat the body immediately starts using all that delicious sugar it got. After a while it starts running out of sugar an...
I was told that headphones can never accurately reproduce sounds because the drivers are too small, is this true?	[ "Headphones can be small but still efficiently radiate low frequencies into your ears because the acoustic impedance of your ears is similar match to the headphone. The acoustic impedance of free space, however, is not a good match and therefore headphones make lousy loudspeakers, especially at low frequencies. You...	[ "You are probably talking about some kind of electron microscopy (most likely [Scanning Electron Microscopy](_URL_0_)). These images are grayscale because they are simple intensity maps. Now, you are completely right in thinking that it would not work to acquire images of ~30 nm components using standard optical mi...

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.