Subset (10)

eli5 · 25k rows

Split (1)

train · 25k rows

query stringlengths 20 300	positive listlengths 1 1	negative listlengths 1 1
How can people afford to live on minimum wage?	[ "They can't. They either have several jobs, are not the sole provider, are in extreme debt that they can never get out of or receiving government assistance. Or all of the above." ]	[ "You can manufacture drugs basically anywhere if you have the supplies, basement of your house, some run down warehouse, and super-lab underneath a laundromat, etc. These labs are routinely found and shut down." ]
What does aspirin do that helps prevent heart attacks, stroke and now cancer?	[ "For the heart attacks and stroke risks: aspirin thins out your blood, lowering the stress on the veins and arteries." ]	[ "That's it exactly - graphene is a giant, stable structure where everything is already bound to each other and therefore is nonreactive. PAHs, and especially their metabolites, are very reactive and can bind to DNA, causing mutations in DNA that may turn on oncogenes. Take a look at the structure of PAHs _URL_0_ an...
Why does Hawking radiation not have an equal chance of increasing or decreasing the mass of a black hole, causing no net change?	[ "Remember that both the particle and antiparticle have positive mass so the change in the black hole's mass is not because something with negative mass falls in. The reason the black hole loses mass is because for the pair of particles, one has positive and the other has negative energy. The positive energy p...	[ "If you know the full Hamiltonian for your system and the initial state, you in principle know how the system will evolve for all time. The time evolution is governed by the [time-dependent Schrodinger equation](_URL_0_). However you don't necessarily know what the results of measurements will be. For example, if y...
What stops our stomach acid from coming out of the stomach	[ "You have a butthole on the top and bottom of your stomach that opens to let food and liquids in (top) then closes, and one that pushes the waste out (bottom). Occasionally your body will go \"oops this isnt right\" and release what's in your stomach, which is a mixture of acid and whatever you were digesting (vomi...	[ "Can we stop with the anecdotes and give space to scientific answers? Read the guidelines to commenting, please." ]
What is the best, single volume, history book about WWII?	[ "Hastings is a journalist, nothing he'll write about history can be categorized as 'the best'. Try: _URL_0_" ]	[ "Get a feel for what you are reading. Ask yourself do all their arguments follow? Are they sometimes making leaps of logic? Are they priviliging/relying one group of sources, if they are do they explain why? What perspective is the book written from, how might this affect the focus of the book? Are they making bad/...
What in the environment gives Japan, China and other far east places ginkgo, cherry blossom trees et al that are full of vivid colour, compared to Western Europe with a mostly standard strong oak and green leaf theme?	[ "There is very little tree diversity in Europe mostly because a massive ice sheet bulldozed most of the continent. The trees would have tried to retreat south, but the Alps were in the way and presented a large geographic barrier with inhospitable habitat, so a lot of the tree species went extinct locally. In East ...	[ "I don't think there have been extensive studies on the Great Wall in particular, but I was able to find one: _URL_0_ The key figure is Fig. 3, which demonstrates the genetic separation between plants on either side of the wall. Similar studies have been done in other places though: _URL_1_ indicates some kind of ...
If gravity is the weakest of the four fundamental forces of nature, how do black holes manage to become powerful enough to destroy or capture everything near them?	[ "Get enough TNT and you'll have enough power to match atom bomb. Gravity is a force that is stronger when you get closer. Black holes are not necessarily very heavy, but rather very small. You can get closer to them and feel more force. If you squeezed the Sun or even the Earth, you would get a black hole (in case...	[ "A gluon is essentially the strong force analogue of a photon. Photons carry and transmit the electromagnetic force, and are generated by moving electric charge of which there are two types: positive and negative. Gluons carry and transmit the strong force, except that it has six \"color charges\": red, green, blue...
Did centurions have bronze swords? And if yes why? Was bronze considered superior to steel during clasical times?	[ "I have not heard anything about the common use of bronze in Roman weapons, Roman swords were made of iron. Is here a source you are building off of for this?" ]	[ "In addition to [Pompeiian graffiti](_URL_1_) and other [epigraphy](_URL_3_), much of which was quite crude, we also have the books for a number of comedic plays by [Plautus](_URL_4_) and [Terence](_URL_0_) and satirical poems by [Horace](_URL_5_) and [Juvenal](_URL_2_). And what were they like? Much like humor in ...
Why isn't the Mojave desert filled with solar panels?	[ "Well the number one reason is solar is still relativitly new, and it's just not that cost effective to build solar right now (you don't make money hand over fist, so investors are not pouring the kind of money such a project would require). Number 2 is that it's not that east to transport energy, so the users need...	[ "Power. Military grade lasers that can destroy objects require batteries the size of trucks. Size. Said lasers are huge, the most compact I have heard about are anti missile lasers that are fitted on our largest jumbo jets and make use of every inch of the craft for storage of the laser and its battery. Cost. Bull...
How does the spf rating work on sunscreen and how often to I have to reapply?	[ "The SPF number refers to how much of the incoming UV light will make it to your skin when you apply the cream properly (which is, according to wikipedia, 2 mg/cm^2 ). So with SPF 15 you receive 1/15 of the UV, with SPF 30 you receive 1/30, etc. This means that the necessary exposure time to get a burn is increased...	[ "It's all about having an atmosphere, since that's what helicopters need to fly. [This article explains it quite nicely ](_URL_0_) Here's a relevant quote: *\"Elysium was that—unlike an airplane cabin—its atmosphere wasn’t canned up in some hollow tube. A landing spacecraft could enter its air like it would on Eart...
Have monkeys evolved and changed since we branched out from them? And if so, how?	[ "From what little I understand, we never split from monkeys as we know them. At some point in our past we were the same creature, which evolved into 2 separate branches, both of which continued to evolve. One branch eventually became us, the other eventually became monkeys. We never shared the same branch so to spe...	[ "Your asking essentially the chicken or the egg. Example, Did you stomach evolove first and create your brain and extremites to feed it. Or did your brain grow your stomach to power it. Har to say, as without something to feed the stomach, we would have no stomch. Without the brain to run everything, we wouldn't ha...
How did we reach to the conclusion about our moral system?	[ "Morality is an incredibly complex field and is still hotly debated, and there is no consensus. If you mean how we reached the conclusion that things that are universally viewed as evil, like theft, murder and such, are bad, a lot of it comes down to maintaining societal cohesion. Most of these are fairly obviously...	[ "Before I answer, may I ask who the speaker is for this particular lecture? Or if you have a link for me to listen to? I would like to know where they are coming from in their argument." ]
Is time actually linear?	[ "You can't really have a stationary point in 3D space, any point in space is either a point in space and time or it's a line in spacetime. I recommend reading [this superb post by RobotRollCall](_URL_0_), it will show that a beam of light is not travelling through time at all. I don't have the technical knowledge t...	[ "I had an interesting discussion about this two months ago in [this askscience question](_URL_0_). Have a read of the top comment tree there. TL;DR: In a way, yes, but in another, more accurate way, no." ]
What would happen if a Volcano formed underneath a huge oil/gas field and erupted?	[ "Hello /u/PhredPhnerd, your question has already been the object of previous discussion, I suggest you have a look at the following thread: _URL_0_ You should find your answers therein." ]	[ "Incidentally, this is the problem that _URL_0_ is trying to solve. Here is the map of the overall plan: _URL_1_ There is enough solar energy in the Sahara desert in 6 hours to power the entire world in 1 year. From the Sahara, they plan on connecting Europe with underwater high voltage direct current lines. The p...
How does live telecasts work and how do they switch cameras while the audience are watching the show or the concert lively?	[ "There's the producer/director in some sort of master control room. This room has monitors that show the feed from all of the cameras and the director will tell the switcher operator when to switch to what camera. The director also has communication with the camera operators so he can tell them where to point & wha...	[ "I was curious about this as well, so I did some google-fu and found some results. This is all secondhand so take it with a grain of salt. It seems that the stations contract survey companies to get a rough estimate based on a sample population in the area. Arbitron is one of those companies. How do they do it? The...
What are the risks of mould in a bedroom?	[ "Molds produce, as do many fungi, a series of chemical byproducts known as mycotoxins. These can trigger flu-like symptoms, inhibit your autoimmune system, and can damage your lymph nodes (which are mainly taxed with clearing your body of stuff you don't want in it). They can also effect your lung's ability to clea...	[ "I’m honestly not sure how much nutritional benefit could be gained, but it wouldn’t be poisonous nor give you cancer. Only side effect would be grossing out the redditors who read your question, afaik." ]
Why can't we store CO2 from power plants before it enters the atmosphere?	[ "Because of how combustion processes work, the pressure of the exhaust system is important to control, particularly to keep it as low as possible (with the functional lowest being ambient). If you put something on the exhaust that captures the carbon, you're increasing the back pressure, which will interfere with t...	[ "If this was possible (it probably is) it would be a horrible idea. You would literally be slowing down the earth. Maybe the effect would be small at first, but it would build up over time. The question is only how long would it take to have an effect, and how bad would the effect be." ]
Do animals resort to incest?	[ "As someone who has kept dogs over a number of generations, I can say that if the bitch is in heat, every male dog around will try and get at her, regardless of whether its his mother, sister, or daughter. Disclaimer: I do not have a PHD, nor have I ever done experiments involving hundreds of animals on the subject...	[ "One recent example of what happens is [here](_URL_0_) This community of Muslims in Great Britain promotes marriage between cousins, and the birth defect rate is dramatically higher than average. **Research for BBC2's Newsnight in November 2005 showed British Pakistanis accounted for 3.4 per cent of all births but...
Is there a non-negligible amount of energy entering our galaxy? Can the galaxy be approximated as a closed system within reason?	[ "A closed system? God no. The galaxy puts out something on the order of 10^37 watts of power, the majority of which completely escapes the galaxy. Dwarf galaxies are being absorbed and torn apart by the Milky Way all the time. Galactic superwinds, driven by bursts of supernovae, drive hot gas out into the outer hal...	[ "We have to apply whatever mathematical models and theories that we do know or have sufficient evidence to believe to be true. We do have at least some knowledge about plasma's behavior (we can make if after all) and the rest has to do with extrapolating from our current understanding of physics. We just try our be...
If your car is on a steep hill or towing something heavy and you push on the gas pedal but the car doesn't move, where is the energy going?	[ "This situation is very much like pushing on a wall with a firehose. If the wall does not move, all the energy stays in the water as it splashes about and knocks other things over. In the situation with the truck, all the energy goes into heating up: gasses exiting your tailpipe, the engine, and the transmission." ...	[ "The way your body uses food is that it burns it with oxygen, much like wood in a fireplace burns. The reaction in your body is a lot more controlled, which is why you don't go up in flames. But it does produce some of the same byproducts, namely heat, carbon dioxide, and water. The same is true for your fat stores...
If disorders like depression and anxiety are chemical imbalances, why are non-chemical treatments like talk therapy effective?	[ "Let's say that the chemical imbalance the person is suffering from is a lack of a brain chemical called X. If the problem is that your brain is not creating enough X, there are two solutions: * Supply additional X artificially (e.g. by taking a pill) * Get your brain to create more X If you can get your brain to c...	[ "Normal weapons are localized. A machine gun can only fire in one direction, an artillery shell can only hit one spot, and even bombs have a smallish blast radius. You can avoid hitting things that you don't want to hit, and if you're not the USA people can call you out for hitting things you shouldn't. Chemical we...
Why I can't charge my laptop with an usb cable and a travel adapter like i can do with smartphones?	[ "Because your laptop requires something around ~~1~~70 watts to operate, and the USB connection only delivers a couple of watts -- maybe 4.5 watts if you use USB 3.0. Simply put, your laptop requires far, far more power than USB was designed to deliver." ]	[ "Incidentally, this is the problem that _URL_0_ is trying to solve. Here is the map of the overall plan: _URL_1_ There is enough solar energy in the Sahara desert in 6 hours to power the entire world in 1 year. From the Sahara, they plan on connecting Europe with underwater high voltage direct current lines. The p...
I have studied that that blood vessels, like any tissue, need nutrients and hence there are tiny blood vessels on their walls known as "vasa vasorum". The question here is, how these tiny structures get their own supply?	[ "These structures are found in the walls of large blood vessels. The large vessel walls are so thick that oxygen does not efficiently cross into all the cells in the wall, so the vaso vasorum supply oxygen to the walls. But the vaso vasorum are small enough that oxygen will diffuse through their tissues. _URL_0_" ]	[ "When you have a large hole, a lot of light from different angles can enter that space. When the space is smaller, less angular, scattered light makes it through the gap. Much like a pinhole camera, the smallest hole means only direct light gets through and that requires less focusing as there is less scattering of...
What happens to your body as you build endurance? Is there any change to your heart, lungs, etc.? If so, how does it compare to a "normal" person?	[ "Yes, your heart can enlarge and become more efficient by pumping the same amount of blood using fewer beats per minute and therefore less energy. You can also change at the cellular level by becoming more efficient at transmitting and using oxygen and removing waste products like CO2 and lactic acid. Your cells ca...	[ "[Source](_URL_0_) The cup (or shell) amplifies the ambient noise, which is the thing you hear. Many people believe it's an echo of your blood, this can easily be disproved. Try to exercise and put the cup to the ear. The noise is no louder, even if you hearth is beating faster." ]
How is it that our bodies don't leak the smells of our innards?	[ "Your esophagus(link to the stomach) is closed by a the esophageal sphincter. Your other end is sealed by the anus muscle, sphincter. Of course you can smell it if your body lets it vent. It's called a burp and fart. Apparently, the seal is tight enough to hold in gas. EDIT: correction" ]	[ "Because thought's capabilities are pretty much infinite, whereas our bodily abilities are limited. If you have heard an accent, you can generate it in your head through memory alone. But to speak in it your vocal cords and tongue and lips, pretty much your entire upper respiratory system needs to know the way to r...
Am I heavier if I fill my lungs with air? (as measured by a scale)	[ "It depends. If you are in a vacuum, then yes, having lungs full of air would make you heavier. If you are in Earth's atmosphere, however, then it would not. Inhaling air makes your body less dense, meaning that the buoyant force of the atmosphere would counteract the increased mass that the air provides. Edit: Act...	[ "It's not you specifically that's gaining mass, it's the entire Earth-you system. You and the Earth are bound together by your mutual, attractive gravitational interaction. When you increase your altitude, you are increasing the potential energy stored in the system, and thus increasing the mass of the *entir...
What is the difference between Obamacare and European-like healthcare?	[ "There are many different healthcare systems in use in Europe ranging from free-at-the-point-of-use primary and secondary care through to mandatory insurance policies similar to Obamacare. Is there any particular country's healthcare system you'd like a comparison with?" ]	[ "This is a horrible map! See if you can find one that lists per capita ratio differences. I think the picture will change quite a bit, and will probably spark other questions." ]
Why do Jet airplanes leave behind contrails that sometimes stay across the whole sky and slowly spread out, other times it is a faint line that only follows closely behind the jet, and sometimes no contrails are present?	[ "It depends on the atmospheric conditions where the airplane is flying. See _URL_0_ Basically, if a plane flies though a patch of sky where the humidity is not close to saturation, then the exhaust will not condense and will thusly not form contrails. If the humidity is close to saturation where a plane flies, a co...	[ "I live near a long string of parks. Over decades I have watcher the behavior of Canadian geese in particular. Groups will do to the golf course or another pond on a regular schedule. They fly a direct route between these locations. They definitely know where they are going. I remember one terribly windy winter day...
Why didn't firearms people other than snipers and machinegunners just paint dots on glass sights?	[ "A reflex sight isn't just a dot on glass, a dot on the glass doesn't show you where the bullet will go unless you're looking at it dead on A reflex sight uses creative lenses and mirrors to make the dot appear \"at infinity\" so it is always straight down the barrel from the lens. This means no matter what angle y...	[ "Sunspots wouldn't be a problem. Astronomers look for periodic diminished light levels, indicating an orbiting body. Chaotic or one time dimming doesn't mean much. In fact, if you're interested and have some spare time, you can [help crowdsource the finding of these objects](_URL_4_)." ]
What would happen if a submarine started leaking?	[ "If you find a leak on a submarine, you do 2 things right away. You surface (blow ballast, steer up) and fix the leak. Unless it's a huge leak, the submarine should be okay. For minor leaks, you probably don't even have to surface if that would be undesirable for whatever reason. As for features of a submarine, as ...	[ "Simply put, both of them. This is due mainly to a geological concept known as the geoid. If you look at [this](_URL_1_) map, you can see that above panama, there is a plate subducting under another plate. Subduction looks like [this](_URL_2_) cross-sectionally. I would wager that the weight of the extra crust is '...
How does our body remain upright when sleeping while standing up? (i.e. In the train, on the bus, etc.)	[ "i just drop like a sack of potatoes. So if there is such a mechanism i want to ask the follow up question why mine doesn't work?" ]	[ "Well for one reason, long-term memory doesn't record in real time. Your brain has something of a buffer for short-term memory to use in the moment, then screens what information is necessary for long term retention. I'm guessing that there is little reason for your brain to record whatever was in your short-term m...
What happens in our body that makes us feel lonely?	[ "That sounds like a panic attack triggered by realising your loneliness. Loneliness in itself isn't associated with your described physical symptoms. On the other hand, panic attacks are caused by an acute activation of your sympathetic nervous system, commonly called the \"fight or flight\" response to stressors. ...	[ "Because everything around you is quieter. There is less activity at night for the most part. If you were at a carnival at 12 am and said carnival was busy, everything wouldn't be as loud, but if you live alone every little movement in your home will seem extra loud since there is nothing causing background noise" ...
Are there limits to what can be absorbed through the skin in the same way as nicotine patches?	[ "There are many [transdermal patches](_URL_0_) out there, and drugs like fentanyl can be introduced that way. However, these patches are often controlled release, meaning it won't get you that \"high.\" Drug abusers get these patches and try to extract the drug out in a more accessible form, such as by cutting and ...	[ "Exhibit A - [The 18th Amendment of the US Constitution which established prohibition](_URL_0_) Exhibit B - [The 21st Amendment of the US Constitution which was ratified just 13 years later and repealed the wildly unsuccessful and unpopular 18th Amendment and ended prohibition](_URL_1_) Prohibition doesn't work. ...
Why are most vegetarians perfectly ok with eating cheese when a large variety are made with rennet? (An enzyme extracted from the stomach of a calf.)	[ "Many vegetarians choose animal-rennet-free cheese. Most types of cheese have alternatives made with vegetarian rennet. Many vegetarians don't know what animal rennet is, so don't know that animals are slaughtered to make the cheese they're eating. Many of the people in said group would make alternative choices if ...	[ "Well it's essentially down to the fact that the mind picks up more from visual clues about where sound is coming from. > \"Ventriloquism relies on the fact that the ability of the human ear to locate the source of a sound without visual and other cues is very poor. What the ventriloquist does is supply misleading...
Why do dogs receive and comply with commands, such as sit, stay, paw etc., but other animals, such as cats, aren't taught or don't respond to those same commands?	[ "Dogs have been systematically bred for obedience for thousands of years. They've been bred for accomplishing specific work tasks that go against their instincts. Cats, on the other hand, are \"domesticated\" but haven't experienced anywhere near the same amount of selective pressure. The only real \"work\" task th...	[ "Yup, the science behind this is quite clear! Low frequencies travel further than high frequencies. On the flip side, it’s harder to identify the origin of low frequencies, they appear to come from everywhere. Think about someone in the next street playing loud music. Do you hear the whole song, or just the deep ba...
Using the same throw force, why does a really small pebble reach under 10m while a larger pebble reaches well over 15m ?	[ "Wind resistance. A small pebble is going to have a much higher amount of surface area relative to its size/weight, and so moving through the air saps it of energy much more quickly than a heavier---and thus almost certainly more aerodynamic---stone. With the two heavier stones, both are heavy enough for the air r...	[ "If you required 10 tons of fuel to get 50 tons off the ground then you'd need 12 tons for 60 tons (out of which 10 was already fuel). The rocket now weights 62 tons. To get 62 tons into space you need 12.4 tons, which increases total weight to 62.4. To get this rocket into space you require 12.48 tons and so on. N...
What does Serotonin do exactly and how does it work?	[ "Low serotonin levels have been linked to depression. Serotonin is an important chemical and neurotransmitter in the human body. It is believed to help regulate mood and social behavior, appetite and digestion, sleep, memory, and sexual desire and function. Here’s a definition." ]	[ "Could somebody explain how, if true, small amounts of alcohol is good for you?" ]
How are downloads and storage mediums so accurate, such as keeping billions of bytes without a shred of noticeable corruption?	[ "There are two aspects to this question - how do we verify the integrity of a set of data, and how do we correct the data if we find corrupted bits? Data integrity is attacked by random corruption all the time, both on transmission and in storage (cosmic ray bit flips, random internet packet shenanigans), but integ...	[ "[This video explains quite well how it works online, specifically Youtube](_URL_0_) TL;DW: Youtube only sends information about changes between frames of a video. Since there is usually very little difference between 2 frames the server can just say \"ehhh take what you had last time, shift this part a tiny bit th...
In swimming, how can the world record for an individual event be slower than a single leg of a relay?	[ "Competitive swimmer here. So part of that particular example was that Lezak's swim was an unreal performance spurred on by some serious trash talking by the French. But in general, it has to do with the difference in the start. The individual events start how you imagine. The starter says \"take your mark\" and th...	[ "This question is getting a lot of traffic after being [tweeted by @reddit](_URL_5_), so I thought I'd welcome those of you that haven't visited /r/AskHistorians before to the subreddit. Please do bear in mind that in order to keep the quality of answers here high we have [strict rules on comments](/r/AskHistorians...
How a Reddit post can show that it has comments, but none are visible.	[ "If a mod deletes a comment it'll still be reflected in the total number of comments. That's the usual reason more so than a shadowban. Source: I'm a mod." ]	[ "Your voice cords need a certain minimum air pressure to get to vibrate and create tones. Without them vibrating you're getting a toneless whisper." ]
Why is it harder to cycle uphill? Is it just the effects of gravity?	[ "Gravity is like a constant wind blowing while cycling. Travel with the wind, it pushes you along, reducing the energy required to maintain any given speed. Travel opposite the direction of the wind, you have to exert more energy to push through the wind that is trying to push you the opposite direction." ]	[ "Plant cells have little starchy organelles called statoliths - they're much heavier than other components of the cells. The statoliths fall to the bottom of the cells. In cells in the stem, statoliths on the bottom of the cell trigger the hormone auxin to inhibit growth on the lower part of the cell. This makes ...
I heard people used to drink pretty much only beer in some periods in history. How did they not get drunk/hungover all the time?	[ "The beer was substantially weaker and was often the only source of relatively clean water in an area. As brewing techniques and ingredients improved, the beer got stronger." ]	[ "Horse meat isn't rare at all. You can get it in many parts of europe. Tastes ok too. Anyway, that's culture. The same reason we think that bacon and eggs is a breakfast food, and don't eat grasshoppers." ]
Why does the passage of time change when space is curve? Or, why/how is time so inextricably linked to space?	[ "The answer is ultimately because that's how the universe works. This is really all science can say. We've rigorously shown via the scientific method that this model of reality is extremely accurate and precise at predicting the behaviour of the universe, but that's all science actually does. The question 'why' is ...	[ "I encourage you to read David Deutsch's book The Fabric of Reality. The chapter on what time is (and isn't) will likely help you think about these things. It's worth the effort to read the book. (It is written for non-specialists who are willing to think.) Deutsch, by the way, is a theoretical physicist who has ...
Why does staring at an image for a while make it print onto your eyesight?	[ "Its something we don't fully understand yet. We know what physically happens at first.. The different photoreceptor cells in your eyes become fatigue and desensitized. They release much less of the signal you'd normally get from the wavelengths of light. That is the physical mechanism that leads up to the afterima...	[ "It's a consequence of general relativity. The two fundamental principles of GTOR are: > 1. Matter and energy curve space time. They shape the geometry of space time > 2. Objects move in the straights possible paths through this space time. Because space time is curved those lines are not straight. So this mean...
Why don't germs develop a resistance to handsoap, like they do with antibiotics?	[ "Handsoap doesn't kill germs. It just washes them away. They're still alive, just down your drain now instead of your hands. Because handsoap is PHYSICALLY removing them and not CHEMICALLY killing them, they can't develop a resistance to it. -- > Edit: As /u/willfap5pron notes, there are antibacterial handsoaps con...	[ "[Here is a basic sketch of soap's structure (surrounding a grease particle).](_URL_0_) The secret behind soap is its structure. More specifically, it's how different parts of its structure behave. The head of each soap molecule (the round thing) is hydrophilic, which literally means that it loves water (it dissol...
How "flipping" my car's rear view mirror makes it more dim (instead of just showing me my back seat).	[ "The glass covering the reflective surface is wedge shaped. When you flip the knob, the mirror moves up just enough so the you just get the reflection off the glass." ]	[ "They work because light is a wave and by using the principle of superposition. Here is a simplified explanation. When light encounters the coating some will be reflected (call this Reflected Light 1) and some will be transmitted through to the lens. When the light reaches the lens the same thing happens: some is t...
Why are social media sites (Facebook, Reddit) so liberal despite the overall population being split nearly 50/50 among party lines?	[ "I have to contest your claim that they're all so liberal. Most social media sites, by design, either make you follow people and/or show you content that's similar to content you've already indicated you've liked. Or, content your friends have indicated they like. Reddit definitely skews liberal, but it has som...	[ "There's something called cognitive dissonance, which is a mental condition in which your brain is torn between two mutually exclusive ideas, thoughts, memories or concepts. It's an extremely uncomfortable state to be in, and the brain will jump through some pretty crazy hoops to resolve the situation. Most coping ...
How can subliminal messages provoke a response without us consciously registering them?	[ "Your brain can be primed, meaning if you activate certain sensors with certain stimuli, you will be quicker to recognize the stimuli the second time you experience it. Just because the stimulation does not register with your consciousness, doesn't mean those sensors weren't triggered. That \"subconscious\" stimul...	[ "Because when you're watching a movie or a TV show, you know what you're watching isn't real. You know you're not supposed to actually believe it, but you suspend that disbelief in order to enjoy it more. This is the exact opposite of ignoring stuff you do believe." ]
How does smell work? What physically composes it, and how do we perceive it? How can a smell linger so strongly even after you thoroughly clean something?	[ "Your sense of smell is a chemical detector. Odors are just molecules floating around in the air. When you smell the scent of an orange, you're detecting molecules from the orange inside the air you breathed in. I'll pause for a second while, armed with this knowledge, you now contemplate the smell of farts. Smell...	[ "Yo ho ho! Yer not alone in askin', and kind strangers have explained: 1. [ELI5: Does all the dust and dirt we breathe in during our lives just build up in our lungs? ](_URL_1_) ^(_48 comments_) 1. [ELI5 : What happens to objects that you breathe into your lungs? ](_URL_0_) ^(_13 comments_) 1. [ELI5: How does the l...
Why when I put a cold stick of butter in the microwave, the middle of the stick turns to soup immediately but the ends are still solid?	[ "That's because of how electromagnetic radiation works. The frequency at which a microwave operates is such that the length of the electromagnetic waves is a few centimeters. Inside the microwave oven are many such waves, and some of them overlap. Where they do, they can either amplify eachother (if they're the sam...	[ "Here is a great animation: _URL_0_ As you can see from the animation, the inner surface of the pen is grooved. The button has a \"holder\", which holds the pen shaft in place and slides back and forth on the grooves. The shaft has a complementary part that fits into the holder. The holder is designed such that the...
Does a refrigerator/freezer use less energy when outside in a cold environment?	[ "It would also use less energy in the cold because it will be exchanging heat in the cooling coils easier/faster." ]	[ "yes, it's not the number of calories per se but giving the body longer in a state of reduced metabolic processing ie rest. The modern accessibility of food means people are eating more than we have evolved (without exercise to earn it) thus have a constant need to create insulin and fat cells - > obesity & diabete...
NOx to nitrite and nitrate conversion	[ "Natural nitrites and nitrates in many natural systems are are produced by the oxidation of ammonia (NH3+) into those compounds by nitrogen fixing bacteria such as the Nitrosomonas spp and Nitrobacter spp. Often, reduction of nitrites and nitrates forms molecular nitrogen, ammonia, and nitro-acids. In the human bo...	[ "M^-1 s^-1 ? Are you sure you are talking about first order and not second order? And at what temperature? I worked with tetrazine/trans-cyclooctene reactions with second order rate constants of some 10-100 millions (at 25°C), but those are fully diffusion controlled." ]
Weather Maps and how to read them.	[ "If you're talking about regular maps. [This looks like a nice key to everything.](_URL_1_) Wave maps [like this](_URL_0_) show how tall the waves are and in what direction they're going in." ]	[ "Those kind of fortune telling/horoscope thingys are usually formulated in a very inaccurate way. Things such as \"You will meet an important person tomorrow\" can be twisted to fit in just about any situation you find yourself in, if you believe in that sort of stuff, you will interpert it as a phropecy coming tru...
Why do we have to pay for cable/satellite/fiber optic TV each month, when all the shows still present ads?	[ "The bill you pay every month is for the infrastructure to deliver the cable single to your house. The commercials are to pay for the actual programs that you watch. It's like asking why you have to pay for a train ticket just to visit another city when you just have to pay for all the stuff you do in that city." ]	[ "Many of the products sold through infomercials, especially information products, are not actually created until an order is placed. So, you may order a DVD set today but the next batch of orders are not created until the next week. It's a sort of 'standard' that the price of shipping should cover the entire cost o...
Why was the train invented before horse-less land vehicles?	[ "Nicolas Joseph Cugnot designed a steam powered vehicle in 1770. It was supposed to be a tractor that pulled artillery for the French army. It was very difficult to steer and very slow, with a top speed of less than four kilometers per hour. The internal combustion engine was not invented until the 1880s. Steam ...	[ "This has essentially been answered by the preceding comments, but what hasn't been contributed is this: _URL_0_. Muster and enrollment records, transfer lists, honours lists, etc, for the period of 1730 through 1898. Worth having, OP, if you're writing or researching the topic academically. To succinctly summarise...
how does the Google maps app on my phone know how much traffic there is on a road specifically down to each intersection on the same road (alternating green and red)?	[ "Google Android has a feature that sends location data to the google servers, even if you have GPS turned off. If you use a Google Android phone, you can actually view your own data if login to Google and goto this site: _URL_0_ What Google is doing is fetching all this data that is sent from all the Google Android...	[ "When a speaker vibrates, it doesn't have to move in a single pattern. It can push out, pull back all the way, push forward a tiny bit, push back a little, push forward more, and so forth. When you consider the two frequencies of sound you mentioned, when they get added together- whether they were both played in fr...
Why is it better to compost food scraps/garden clippings rather than put them in landfill? Wouldn't they have the same environmental impact regardless of where they biodegrade?	[ "Composting is an actual biological process that requires certain steps and conditions in order to properly breakdown and gain access to the nutrients. Which can then be added to soil to fertilize it. When the same stuff is sent to a landfill it gets buried under a mound of water tight clay, essentially locking it ...	[ "I have a chackboard with 100 words written on it. You ask me to delete every word that starts with A which there are 6 words. They're written randomly on the chalk board. I need to search for the words, and then neatly delete the words without deleting anything nearby. But you instead asked me to delete everythin...
Why try for a constitutional amendment, when it is easier to just make a law?	[ "The Constitution > Federal Laws > State Laws > Local Laws & Ordinances You pass an amendment when you want something that can't be done with laws, usually because the current constitutional wording prevents your thing or doesn't support it. Thus the courts have invalidated laws, if you change the constitution you ...	[ "Picture this: It's September 2001. The worst terrorist attack on American soil has just occurred. The twin towers were demolished in spectacular fashion. The Pentagon has one of its wings in rubble. Over ~~5,000~~ 3,000 Americans are dead, 6,000 injured. People are shocked, bewildered, and angry. \"How could this ...
Do severe burn survivors dehydrate faster than unburned people?	[ "One of the functions of your skin is to keep moisture inside your body. With a lot of your skin burned off, there's nothing doing that any more." ]	[ "A couple important things to remember: First, this is the hottest year since we've started recording them, and recent years have been similarly high. But another reason is because of how we design buildings. We design them to use air conditioning and the like. But back before AC, people had buildings designed to b...
Is it true that in World War I, aviators would drop thousands of metal darts on ground soldiers?	[ "[Flechettes](_URL_1_), to use the technical term, were used extensively and somewhat successfully as an anti-infantry device, and also less successfully as an anti-zeppelin device. The idea was that just by dropping them en mass (boxes contained up to 250 darts, and [multiple boxes](_URL_0_) could be carried on a ...	[ "You have to remember that putting the head of a criminal on a gate , or \"gibbeting\" the whole corpse, for public display was a commonplace of 17th century justice in England, had been for quite some time. Gibbeting would be continued into the 18h century. Puritans were not exempt from using it, or other cruel an...
Why no mobile company made the Ideal Phone which consists of best camera, battery, display, processor, design and etc..?	[ "Phones are already expensive. Using the absolute best parts available at the time to create some überdevice would cause the price to skyrocket and only a select few people would be able to afford it. It would probably cost the company more money to put something like this together than they could earn by selling i...	[ "Brains easily perform many, many tasks hat are difficult for computer. Take that we know brains are optimized for pattern-finding. Consider intelligent life forms have to interact with a real 3-world and real time. Which means they can check their expectations. Testings a supposition is as simple as rotating an o...
Why do plants that are not desirable for gardening become invasive species, but the plants from my local gardening center that people plant in their front yards all the time don't become invasive species?	[ "It is not always as you describe. Where I live we have a real problem with [Pampas grass](_URL_0_). It gets huge and spreads easily and smothers native plants but people love them so gardening centers and nurseries continue to sell them so it is a constant battle. I work with a woman who is part of a volunteer gro...	[ "Liking certain tastes is genetic. Sweet and salty are universally liked since liking these flavors led ancient people to seek out foods with necessary vitamins, minerals and other nutrients. Aversion to bitter is said to help in avoiding toxins. How one tastes things is to some degree genetic- cilantro tastes wond...
What does it mean when people say "the American middle class is being hollowed out"?	[ "It means, for the most part, they're becoming poorer. That there's less middle class and more poor people. There are very few people that go from being middle class to being 'wealthy,' in general. It happens, but it isn't extremely common." ]	[ "Basically, you split your investment portfolio into two groups - core and satellite. The core part is the largest and usually consists of safe, passive, dividend-earning investments. It probably won't beat the market, but it will grow nicely over time. The satellite portion of the investment is smaller and is wher...
Why is the periodic table the way it is? And metals that don't resemble metal?	[ "> How are things like calcium and potassium known as \"metals\" (alkali earth metal, and alkali metal respectively) but when I see a calcium or potassium pill it looks nothing like a metal? Pills don't contain calcium or potassium metals, they contain calcium and potassium compounds. [Pure calcium metal looks like...	[ "Disclaimer: amateur astronomer. I have a clue, but no guarantee that I'm right! In the past, large telescopes like the 200\" at Mt. Palomar would be just one large circular mirror. When you try to scale up much beyond that, you get problems like the mirror sagging under its own weight, ruining the image. The moder...
Why do the 8 B vitamins have numbers that are different? Eg B9 and B12	[ "When the B vitamins were originally being numbered, all of the numbers were used. After a while, though, they discovered that some of the purported B vitamins weren't actually vitamins at all: either they weren't essential (incapable of being synthesized by the human body) or they weren't nutrients (important ...	[ "That's called special billing, and it's usually something that high-profile, stand out actors will request as part of their contracts to make them stand out from the rest of the cast." ]
Why does it seem as though dry cleaners are universally closed on Sundays?	[ "Because Sunday is a standard day for businesses to be closed or have reduced hours." ]	[ "They use a wavelength of light that is cancer causing. Do you want to sit under a cancer causing light? Plus, they aren't all that effective to stop, say a sneeze from transmitting to another person. It takes some time to kill the germs." ]
Why is the crust of a hearty hunk of bread considered the most nutritious part, when the inside is composed of the same ingredients?	[ "For the most part, this is just a widely perpetuated myth. It's mostly just something parents tell their children so the kids will eat the crust because children are notoriously picky eaters. There's some minor evidence that there's a few exotic nutrients that are more prevalent in the crust but it's a recent st...	[ "One big reason is map design. No road that goes north is straight. They are all designed to be curvy. This gives the impression that the map is larger because it takes longer to traverse." ]
Throughout historic feudal societies, how common were murder, rape and other atrocious acts committed by the higher classes onto peasants or similar lower classes.	[ "Although noble lords of Western Europe had ridiculously specific privileges and rights, including the right to certain animals, maritime rights, and the right to wear ermine, gold cloth, and precious stones (specific to lords with lands worth 1000 pounds annually and their families in fourteenth century England), ...	[ "In addition to [Pompeiian graffiti](_URL_1_) and other [epigraphy](_URL_3_), much of which was quite crude, we also have the books for a number of comedic plays by [Plautus](_URL_4_) and [Terence](_URL_0_) and satirical poems by [Horace](_URL_5_) and [Juvenal](_URL_2_). And what were they like? Much like humor in ...
How is NASA able to download data from from satellite like Hubble telescope and Juno?	[ "There are antennas on Juno that send out the information and giant dishes in different parts of the world that can pick it up no matter what side of Earth is facing Juno. It takes about 48 minutes for the signal to make if from Juno to Earth at the speed of light." ]	[ "They store it all on a hard drive the size of Texas! Actually, it's split across thousands and thousands of hard drives, in probably hundreds of buildings. Here's a [picture](_URL_0_) of just one of them. This one is in Iowa." ]
Why do our bodies often reject transplanted organs?	[ "Genetics. It's an organ, but it's not YOUR organ. Your immune system sees it as a foreign invader and tried to attack it, which is why transplant recipients have to take auto-immune blockers for the rest of their lives" ]	[ "Costs money to build and maintain the facilities, some countries don't feel like taking on the burden of that cost." ]
How do we decode/understand ancient languages without native speakers?	[ "It's a very complex process that takes a lot of intuition. When you look at something you don't understand, you will see something that sticks out as repeating a lot. With an understanding of linguistics, you can ask \"Is that an a or an I? Or is it another pronoun, like you or we? Perhaps a conjunction\" Then, yo...	[ "Most have a [relay phone](_URL_0_) in their homes - they use an interpreter. [TTY](_URL_1_) is also available on mobile phones, landlines, and in 911 centers." ]
Are there currently more human skeletons then there are humans living currently?	[ "Yes, because all living humans have a skeleton, and there are some skeletons which don't belong to living humans." ]	[ "Not any time soon. For example, in 1787, Mozart created a game when you rolled dice to randomly select measures you could put together to build a waltz. Turns out there are over 700 trillion combinations, meaning every man, woman, and child in the world could each have 100 million unique waltzes \"composed\" by Mo...
Why don't YouTube videos load and play without buffering throughout the whole thing?	[ "The real answer is because most people don't watch a full video. It gets expensive and strains there servers when a video buffers all the way through if you aren't going to watch it all. To help with this problem the split the video into different sections. Once one section buffers it won't buffer the next till yo...	[ "All your ISP can guarantee is the speed between you and their servers, and that they have a sufficient backbone connection to support their advertised speeds. The speed of the rest of the net is dependent on, well, the rest of the net. If you do speed tests to different parts of the country/world, you'll get some...
Why is it illegal for women to participate in bullriding and similar rodeo events?	[ "It... isn't? Just take a look at the [Women's Professional Rodeo Association](_URL_0_), formed in 1948, surely you don't think they are all lawbreakers? I'm not sure where you are getting your information but in the US at least bull riding and rodeo are open to both genders." ]	[ "Some animals have bacteria harmful to us in their tissue before they are killed. These animals have to be cooked before eaten. Most notably, this includes chicken. Any ground meat can be contaminated in the grinding process, and must be cooked. As an aside, In the US, there used to be a problem with Trichinosis in...
Why don't antibiotics kill our mitochondria?	[ "Some actually do. Antibiotics can cause mitochondrial dysfunction, we just have enough of a functional reserve to be able to handle it. Many do cause oxidative stress and damage though. As for why they don't kill all of them, there are many reasons: * Most Antibiotics don't penetrate cells very well to get to the...	[ "Turns out the experiments published were less than convincing. There were quite a few blog posts and letters in Science that went back and forth over the presented data. No one, except maybe the original experimenters, really believes (yet?) that this is a new arsenic-using life form. _URL_2_ _URL_0_ _URL_1_ Some...
Can a quarterback say something that sounds like hike in order to induce offsides from the other team?	[ "Yes. The play starts when the ball is snapped and if the defense crosses the line of scrimmage before that, it's an offside penalty. The problem with this, of course, is that your own team mates fall for it as well and you end up with a false start and penalty on your own team." ]	[ "I think it was more about how Mitt Romney claimed the President handled the issue. In recent history, President Bush received substantial criticism for continuing to read to children instead of immediately leaving the room to handle the issue. In turn, Obama criticized the Governor for sending out a press release ...
Would we still need Hazmat suits to cross an area effected by an airburst nuke or could we cross relatively unaffected?	[ "The main delayed radiological effect of a high airburst (e.g., an airburst high enough to not form fallout) is in the form of neutron-activated products on the ground. For several hours this can be very dangerous. But most of these newly-formed isotopes are not very long-lived, so after, say, a day or so, the tota...	[ "you want to get a copy of [this](_URL_2_) to read. :) I should imagine it would answer most of your questions. oh and [this](_URL_2_) as well - great resource on all things about the bomb." ]
Is it more energy efficient to put cold water in a kettle, or hot water?	[ "If this is a hypothetical, no biggie, but if you are considering using the hot water tap to fill your teakettle, I would seriously recommend considering lead exposure, depending where you live. Where I live in NYC, you should never drink water from the hot water tap, and even cold water is recommended to be flushe...	[ "It's basically that, in cold climates, \"warm-blooded\" animals can keep on trucking while the \"cold-blooded\" ones are sleepy and slow, or hibernating, or actually dead from the cold. If you put [these guys](_URL_0_) and [these guys](_URL_1_) together on a tropical island, then the jackals are going to have to ...
If protein is what builds muscle, why do we need to eat at a caloric surplus?	[ "Your body can convert proteins into glucose. If you are in a caloric deficit, then this will be going on. Proteins turned into glucose is protein that cannot be used for muscle. Having a caloric surplus ensures that you do not have a caloric deficit, so very little of the protein gets turned into glucose, so it ca...	[ "Casein in milk binds to fats and oils and other things, my guess is it binds to the oils/fats in your mouth to clear them (cleaning your palette), unlike water which would just spread the oil around. Clearing the palette will make the next bite taste like that first bite, which is always the most delicious." ]
Why is DDOSing so hard to stop for big companies?	[ "It's the first D in DDoS that makes it tough to defend against: Distributed. If someone does a DoS of your phone - calling and redialing constantly, what do you do? Either not answer a call from that number or have it automatically blocked. If it's a DDoS (calls from lots of seemingly random numbers), you have to ...	[ "Usually with sites like Wikileaks or say the more often target Piratebay the servers are not in the US or other friendly nation so they cant just walk in and flip the switch. If they can manage to remove the site they often have mirrors and other servers ready to spin up and put it back online elswhere." ]
How large banks "bet" against their own investment products. How do banks sell investments opportunities and then profit when they fail?	[ "They bundle together a group of investments and then essentially buy 'insurance' so that if they fail they get covered by the insurance. The insuring companies would do this because they believed these investments were solid and wouldn't fail. So when they did fail, and we all found out later it was because the ba...	[ "WW2-era the GI bill was created to give jobs to veterans. Loans were later extended to low-income students as part of Johnson's Great Society program. Vietnam war led to an increase in college enrollment as a way to avoid being drafted, and to prevent a post-war crunch the bar for getting a loan was raised. Today ...
What is fanniemae and freddiemac, and how are they related?	[ "They are companies that are privately owned, but sponsored by the government. They purchase mortgages from lenders. Say you get a mortgage on your home through Wells Fargo. Wells Fargo has limitations on how much money it can lend. As your loan sits there with Wells Fargo, it constricts how much they can loan. So...	[ "A news article and paper (Madera et al. 2009, see below) were forwarded around my department a few months ago about how women are described differently than men in reference letters and the consequences of that. They found that: 1) people described in reference letters that used \"communal\" or \"emotive\" words t...
What makes the difference between 440hz on a guitar vs 440hz on a piano?	[ "The difference is called \"timbre,\" and it's made up of a lot of stuff. For one thing, even though 440 is the fundamental frequency, either instrument is actually producing a lot of other frequencies (\"overtones\") at various volumes. The added effect of these makes the same note sound somewhat different. There'...	[ "Cooking meat to temp is primarily to kill off bacteria. While it does affect the result in terms of texture and taste, it doesn't change the overall structure of what you're eating. A steak is still a steak at 135° or 160° or even raw at room temp. Baking is more of a chemical process. Just getting the center of a...
When did the Germans start to see themselves as one people as opposed to many?	[ "Most of the main milestones happened in the 19th Century. But it perhaps started in the Romantic Era with Goethe etc in the 18th. Goethe, Schiller, Kant all pushed the idea of a German culture. It was a nationalistic idea based in romanticism. There was a weak German Confederation set up in 1815 By the Revolutions...	[ "Hi there -- while we've approved this question, we would like to remind potential respondents of our [current events](_URL_0_) (AKA \"20-year\") rule -- it's fine to discuss events through 1997 (inclusive) and their effects, but not events after 1997. Thanks!" ]
When a corporation makes a profit, where does that money go?	[ "Some profits may go into the bank (or investments), to be used later. Some profits may go into expanding the business over the next fiscal period (thus going to pay for future expenses). Some profits may go into repurchasing shares. Some profits may go directly to shareholders as dividends." ]	[ "First off, I'm curious what doctor has actually taken blood because in my experience it's almost always a nurse or lab tech. But to answer the meaty part of the question - blood goes to the laboratory usually where it's often either run on analyzers or processed to be shipped to another laboratory to be run on the...
Why do magnets "die" after a while of being used?	[ "Imagine the atoms in a magnet as little arrows. When manufacturing magnets, all of the arrows are arranged In one direction. This is done because it makes the arrows useful. ⬅️⬅️ ⬅️⬅️ These arrows don't like to all go in the same, linear direction. This is because they don't like their tips touching, or even gett...	[ "Every time you make a copy of a cell, there is a chance for errors. For example when you photocopy a first print, it is pretty crisp and close to the original, but there are a few minor discrepencies. Now if you photocopy the copy, it gets more distorted, and so on until some letters get hard to read, it gets diff...
Is it possible to change the genetic information of an organism after Birth?	[ "You are talking about an ideal world, but if we did correct the mutation in CF, then it would clear up the disease itself rather quickly. The major issue with CF is the recurrent infections you can get, but assuming those haven't done any lasting damage to your body (and assuming you weren't hit with any of the mo...	[ "The fundamental problem is that the user has physical control over their own PC and the only information the game manufacturer gets is whatever their PC sends. > Doesn't their code have digital signatures? Sure, and those can always be defeated someone with enough time and perseverance. Let's say the code is runn...
Why does the sound of running tap water make me need to urinate?	[ "I'm only speculating but it could be Pavlovian response. You've probably heard of Pavlov's dog where the scientist would ring a bell and then give the dog some food, repeat, repeat, repeat. Eventually the dog would associate the bell with food and begin salivating at the sound of the bell, whether there was any fo...	[ "I don't think you are going to get a valid answer. Music in and of itself is a confusing scientific phenomena. Our attachment to it is a strange byproduct of various cortical functions. We don't really understand why it exists (though there are many theories, none with anything close to proof). The most likely exp...
why doesn't your heart ever get tired?	[ "Cardiac muscle is different than all the muscles that you can consciously control. It's evolved to work 24/7 throughout your life. It gets a little break in between beats, so it's not like it's constantly exerting force." ]	[ "Song lyrics rhyme and have a set pattern. Brains love patterns, because they are predictable. Easier to work when things are predictable, and your brain is working all the time." ]
why does the U.S. incarceration rate dwarf those of other developed western nations?	[ "Our legal system is... a bit of a mess. People go to prison for relatively minor non-violent offences, for one. We also have for-profit prisons, and there's not a huge focus on rehabilitation, just on punishment. As such, the recidivism rate (that is, the rate where people who have been to prison once tend to go t...	[ "Politics. It's an easy issue to use to paint your opponent as \"evil\" regardless of which side of the debate they are on." ]
When a person does 'cos(theta)' or 'sin(theta)', how exactly does he/she figure it out from just a number?	[ "sin(x) = x - x^3 /3! + x^5 /5! - x^7 /7! + x^9 /9! - .... with an infinite number of terms following that pattern. The more terms you sum, the closer you get to the true value. Once you sum enough terms, it gets to the point where the value you get is basically the true value with negligible error. Cosine has a s...	[ "> you check your accounts 'n stuff to make sure you don't owe anything to the IRS and have paid the correct amount in taxes? Yes, this one. There's an IRS form you have to fill out with information given to you by your employer, and other stuff you might have. You have to report your earnings, how much has alread...
Would walking on water be slippery?	[ "Potentially, like you said walking on ice the water acts as a lubricant between the surfaces, since the free movement of water molecules enables a fluid layer between what is two solid surfaces. However, if we're assuming you can \"walk\" on the water as if it itself a solid surface you would have to question how ...	[ "So the key factor that made aeroplanes practical at the turn of the twentieth century was lightweight internal combustion engines. Since you need this invention for a propeller driven lighter than air craft, these don't exist before aeroplanes because they depend on the same key technology. (After airplanes, Zepp...
We know that vision is light reflecting from into our eyes, sound is vibration. But what is smell, what is going in the molecular level that makes a substance produce odour?	[ "The presence of actual molecules themselves. When you smell shit, it's because there literally are tiny pieces of shit in your nose right now that are bumping into a special kind of neurons." ]	[ "The chemistry is described [here] (_URL_0_): the sulphur compounds in smelly substances react with the steel and are neutralised." ]
EPLI5: Why did this election cost six billion dollars when we have entered the age of free information?	[ "Information is free, but television commercials are not." ]	[ "I have the same problem when I try to explain these sorts of things to people. They usually reply with \"why does it matter\" or \"why are we wasting money on that\", I find its because they don't understand the correlation between science and the things they take for granted, such as electricity, their computer e...
If group 18 elements are inert, then how can a noble gas form chemical compounds with other elements (particularly Fluoride and Oxygen)?	[ "When it is said that they are inert, it does not mean that they are incapable of producing compounds, it simply means that under normal conditions, the noble gasses tend to stay by themselves because they already have 8 valence electrons and are in their \"happiest\" state. Under certain circumstances, noble gasse...	[ "France had to pay an indemnity of 700 million francs (about a month's GDP) and host an Allied occupation force, which was withdrawn in 1818. The provisions were generally lenient because both the Republican and Napoleonic regimes were gone, to be replaced by the restored Bourbons whom the Allies viewed favourably,...
The difference between Wi-Fi and 3G/4G	[ "3G/4G use the mobile telephone network - the internet data goes through telephone towers. WiFi uses your home (or work, or school) internet connection. Normally this means you have a WiFi router which connects to either cable or ADSL - a physical wire going to your house. One place you might notice a difference is...	[ "Here's a pretty good explainer. _URL_0_ Basically it comes down to different memory, different promises (reliability and service life), and different marketing." ]
Is there any truth to the common "opinion" that balding indicates higher levels of testosterone?	[ "Male pattern baldness is in fact androgen related-but it's because of DHT (dihydrotestosterone), a testosterone metabolite, not testosterone itself. That's why Propecia (finasteride) works as a hormonal treatment-it blocks 5-alpha reductase, the enzyme that converts testosterone to DHT." ]	[ "Interestingly, inner ear hair cells do not fire action potentials (as many neurons or electrically excitable cells do not). Instead, when stereocilia are bent by sound vibrations, the hair cells are depolarized ('stimulated') in ~~a manner proportional to~~ an amount dependent upon the amplitude of the sound (how ...
Why do people who have used lots of psychedelics have "that look" in their eyes, and what is it specifically?	[ "Be wary of confirmation bias. How many psychedelic warriors do you think you've failed to notice?" ]	[ "> So my question is, if I am able to observe the Pleiades as I travel towards them at 77% of the speed of light, does it seem like time there is rapidly accelerated? i.e., will I observe planets orbiting their stars at 40 times the regular speed? And if so, why? And if not, why not? No, in fact, you will see their...
Why do cars take longer to warm up as they age?	[ "Not nearly enough information to actually answer the question, but if the car is at operating temperature, and still not providing heat, I'd have the coolant system checked. You could be low on coolant, have an air pocket, or something could be broken/clogged. A car should not have \"aged\" between August and Nove...	[ "The chemicals which we smell have different tendencies to vaporize at different temperatures. Changing the temperature changes the mix of chemicals in the air, and by extension the smells you perceive." ]
Do the contents of our blood have any affect on mosquitos after they drink it? Do drunk people make drunk mosquitos?	[ "I think the answer is, \"[we don't know](_URL_0_),\" but it seems that mosquitoes are more attracted to drunk people, than sober people, and according to the article I linked fruit flies do get drunk, but have a high tolerance. Same article also says, \"Any liquid other than blood is diverted first to a separate ...	[ "C2H5OH (ethanol) vs H2O (water). Ethanol is alcohol. It does freeze, just at a colder temperature than water. Ethanol is a bigger molecule than water; the electron distribution is also more equal (but still favoring the -OH side of the molecule). Water is more polar, so the molecules are attracted to each other (l...

Subsets and Splits

No community queries yet

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