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7f1puo | Where does the average human height (say 170cm) fit on the cosmic scale from the smallest known piece of matter to the largest known distance? | Planck length is roughly 10^-35, distances smaller than this are not described usefully by modern physics. The diameter of the observable universe is roughly 10^26. However this value is constantly changing so it's less fundamental than the planck length.
Still, your height is about 26 orders of magnitude smaller than the largest distance, and 35 orders of magnitude larger than the smallest distance. | 69f96a92-b1a6-4566-b956-7a34a9932ed2 |
2bnnbg | How do my reflexes close my eyes before I can process what happened? | You're made aware of it *after* you've processed it. The bit of you that you're aware of, the bit you think is *you*, your conscious mind.. is actually the last link in the chain. You're brain registers what's happening, takes action *then* tells you what's just happened.
This is a great clip from a BBC documentary about free will that explains it quite well ; _URL_0_
The presenter sits in an MRI scanner with a button in either hand. He's told to decide left or right and *immediately* press the corresponding button. To him it is instant, he's thought of a side and pressed it.. no delay.
However analysing his brain activity shows you can predict which side he'd pick up to **6 seconds** before he's even aware that's what he'll choose. | 0709c45b-d32b-48b8-b91e-040fb6804f4b |
25nif0 | Why does a GPS unit require signal from at least 4 satellites in order to determine its position? | So the way GPS works is (roughly) that each satellite broadcasts its ID, and the timestamp of its internal clock. Your GPS receiver knows where each satellite is supposed to be, and it can look at the delay in time between the timestamps it sees from multiple satellites (what with the speed of light being finite and all that) to determine its own position .
Let's imagine a 2D example. Say that you're on the ocean in a ship at night, and a heavy fog has rolled in. There are several bell-towers that you know the location of, and you also know that they're perfectly synchronized, but each one tolls a different pitch. So you wait for them to strike the hour.
Now, if there are only two bell towers, then when you hear them, you can use the delay between the two bells to know how far away you are from each of them. Let's say that you figure out that you're 5 miles from bell tower A, and 10 miles from B. If you were to draw that on a map, you'd put a circle with a 10-mile radius around tower A, and a circle with a 5-mile radius around B. Those circles will intersect at *two points*, so now you know that you're in one of those two locations. You'd need *three* bell towers to find your actual position.
But with GPS, you're also concerned about altitude. So now imagine it in 3D space: Knowing your distance from one satellite gives you a sphere of a certain radius, and you could be anywhere on the surface of that sphere. Two satellites gives you two intersecting spheres, which forms a circle (like one bell tower). Three satellites gives you three intersecting spheres, which gives you two points (like two bell towers). And four satellites narrows that down to a single point in 3D space.
So you need signals from at least four satellites to get a 3D location (and extra satellites help compensate for any timing errors). | 96e5a24b-3633-4076-9bb5-7aa52f8c799f |
59izgt | I've seen crabs living under water and also living out of water in the sand on the beach .How can they breath in both environments? | "Crabs" is a huge category with many species. Aquatic crabs live permanently in water and have gills like fish. They can go out of water but only for short periods, but then again so can some fish. There are also terrestrial crabs that have lungs and live on land. These guys can swim around and actually hold a bubble of air in front of their face, but again they can only go under for a short time. Intertidal crabs have gills, and then also have cuticles on their legs that help them breathe on land. They have to stay moist though and can't live away from water, but they can breathe in air or water fairly well. | 375eeb92-d566-4854-820e-28335d0490b1 |
6o0jkj | Why do flies and other insects repetitively go into dangerous situations, such as the exact same spot after being swatted at, are they incapable of learning? | In short, yes, their brains are just far too simple to be capable of learning like this.
A fly has very simple sense - > action pathways. While it's possible for certain pathways to be reinforced, this isn't going to happen just from a couple of swats. It's not even clear that the fly's internal map (if it has one) would cover a large enough area to record where they were swatted in relation to where they are now.
As compensation, they have a relatively short generational period, so evolution can "do the learning" for the species as a whole. For example reinforcing that they should fly towards concentrations of diaminobutane and away from diethyltoluamide. | 6c5ecfcc-a7a8-48c8-ab9d-ef25c028b3f1 |
3i3kg4 | Why do we wake up after falling down in a dream? | Dreams where you fall and die or similar deaths will trigger a response from your Brain sending signals to your body as a panic response. Think of those as "HEY WAKE UP WE CAN'T BE DEAD".
Same thing happens when you're falling asleep and sometimes you get that reaction. Your body falls asleep faster than the brain and the brain panics and sends a wake up signal to verify that you're indeed still alive.
TL;DR: Your brain panics thinking you died and sends wake up signals everywhere. | 265f12b3-a552-47d4-bf37-61d3c2336042 |
42j2cm | Why do the Japanese like the USA even though 71 years ago they got nuked twice by the USA? | Because we then helped rebuild their country and became a significant trading partner for the next half century (also, don't forget that technically they started that war with us)
In general though, the speed with which the beligerants of WWII became allies is pretty historically impressive. The unification against the USSR certainly helped. | aae89c24-7371-4052-9876-bc0f2a97293d |
7d994m | Why is it easier to look at the Sun with one eye than it is with two? | the total amount of light your brain says is safe to take in is averaged across both eyes. closing one reduces the perceived light intake to ~1/2 and said brain says, "it's cool fam you can look and not damage your retina." but your poor retina still gets the same amount of light and damage anyway. if you do look at the sun your retina will be like, "dude, you just burned me and now I won't work as good. you're a dumb ass." | ce4a7d03-5ccf-4f43-9ef8-a8113af4acae |
25ehkn | Why is it harder to open a refrigerator door the second time after closing the door to the refrigerator before hand? | The warm air that just flowed in when the door was open cools off quickly. That makes it shrink, creating a slight vacuum. Since the fridge is not totally air-tight, additional air is sucked in and the vacuum goes away after a few seconds. | ea803ea1-4657-4af0-be76-8f98dca667f6 |
54q1en | SpaceX's raptor engine, how does it work & is it a major achievement over conventional rocket engines? | The Raptor engine is for the most part "conventional". The biggest advancement is that it runs on Methane rather than hydrogen or heavy fuel like Kerosene.
Rocket motors measure their efficiency with something called specific impulse (measured in seconds) and Isp of 1 second means you can use 1 Kilo of fuel, firing for 1 second, while producing 1 KiloNewton of thrust. 100 seconds means you you can use 1 kilo making 1 KN thrust for 100 seconds.
Hydrogen rockets top out at around 450 seconds while heavy hydrocarbon rockets top out near 300 seconds. Hydrogen is very light, but is difficult to store (requiring very deep cooling) and tends to boil off and evaporate through microscopic cracks. Also it is difficult to produce lots of total thrust. Hydrocarbon fuel is more stable but heavier and less efficient. It does allow for higher thrusts out of the same engine. For this reason first stages getting off the ground favor hydrocarbon fuel and upper stages favor hydrogen. deep space fuel like on satellites to mars once again switch back to hydrocarbon fuel.
Methane fuel acts as a halfway point. It is a balance between the lightness and efficiency of hydrogen and the ease of storage and thrustability of heavy fuels. Some of the implications are that the same engine can be used on most or all stages of a mission, cutting down on the costs and risks of using different engines and fuels from different manufacturers.
bonus: mars' atmosphere has a lot of methane in it (relatively) so it can be directly harvested for rocket fuel. | 6f006859-2de9-45ad-ad58-6e2e6664ff38 |
39y5jl | If you are flying in an airplane and it is storming, can you get struck by lightning if you are flying above the clouds? | Lighting hits planes all the time as most of the time it just passes thru the plane
but some times it can make the plane explode.
[the plane explode ](_URL_0_) | 097b4ad3-1afa-4bed-a3ab-0686e0c4858b |
1izfnh | Prisoner's Dilemma In Real Life. Why did prisoners did better than students? | It turns out that people are not actually utility-maximizing robots. Who would have thought. | 37750afe-4a66-4bba-89df-99d9b6f541c9 |
10w66h | Can we please try to keep questions in this subreddit limited to those that actually require simplified answers? | That's not an appropriate question for askReddit, which is ostensibly for more thought-provoking questions. It would be better for something like r/answers. | 10355c84-3e2d-413d-a873-e6d371e24e7e |
1qex8b | How has the US, which has been much more conservative towards pot than Canada, been able to make all these strides towards legalizing it? | The individual states control their own criminal law. Here in Canada, criminal law is a federal matter. You can't have some province just decide to amend the criminal code. | 7ac8fba8-7bdf-44c6-bf7a-40dc08854841 |
76749u | Why did the US colonies form separately instead of just one big colony? | In places like China or Russia, you had one power trying to subjugate the others and establish a form of central authority. The strongest kingdoms conquered their neighbors and established a unified state. (In China, it fell apart several times and was then re-unified.) The history of the colonies in America is different.
In North America, different groups came to the country for different reasons. One difference was national--the governments of Britain, France, Spain and the Netherlands wanted their *own* colonies that would benefit themselves. But especially among British settlers, each colony was also driven by different ideas. Some went to North America to develop prosperous plantations. Some went there to establish a new kind of society. Some wanted to escape war and persecution in Europe. The British crown granted each colony the right to have a limited kind of self-rule. Over time some colonies got merged, and the British conquered a lot of the foreign colonies.
Before the American Revolution, the colonies were still separate, even though they were all British. They built increasingly close relations with each other, for example they organized a joint defense during the French and Indian War. They saw they had a common interest. When they became upset with Britain, they decided to fight for independence together--different states, but all Americans, organized through the Continental Congress. Even after the Revolution it would take many years for people to see themselves as truly united. They developed a constitution that gave some power to a central government, but left most of the power with the states. The Civil War showed that the states were willing to use force to keep the other members a part of the Union. Especially in the 20th century, federal power increased a lot. But even today, people disagree about how much power should lie with the federal government versus the states individually. | d670cf75-5e71-408c-8894-0744ded7e553 |
38fh4a | What does it mean when one country refuses to acknowledge the existence of another country? | & nbsp; & nbsp; & nbsp; & nbsp;It depends on the circumstance, after all, what is "a country"?
& nbsp; & nbsp; & nbsp; & nbsp;At its core, a country is just the combination of a bunch of rules and the ability of some authority to enforce those rules. Let's say you live at home with your Mom & Dad. They have rules that you must obey, and failure to obey those rules means you get punished. Let's say one day you decide you've had enough of them, so you proclaim, "My Bedroom is now a Country."
& nbsp; & nbsp; & nbsp; & nbsp;You may have the support of your friends and neighbors, but all that really matters is what Mom & Dad think about that. Perhaps they humor you at first and let continue saying you are your own country -- and perhaps you continue to be a good child and still obey your parents. They give you some space and it looks like you are, indeed, independent of the rest of the house...
& nbsp; & nbsp; & nbsp; & nbsp;However, the real test of your independence is "What happens when you disagree with Mom & Dad?" Let's say you refuse to do your chores, and you no longer listen to your parents when they call for you... then, one morning, you wake up and see your Mom & Dad inside your bedroom. You've been invaded.
& nbsp; & nbsp; & nbsp; & nbsp;How could these people intrude into your country? How could they violate your borders?
& nbsp; & nbsp; & nbsp; & nbsp;The real question: What are you going to do about it?
& nbsp; & nbsp; & nbsp; & nbsp;You are just a child inside of their parent's home. Even if you were physically strong enough to fight your parents off of your land, your parent's will call in reinforcements (police) to recognize that they, and only they, own their home.
& nbsp; & nbsp; & nbsp; & nbsp;**However**, let's say that it so-happens that those neighbors who supported you have a lot of power. So much power that they can intimidate your parents from acting against you and deter anyone else from supporting your parents.
& nbsp; & nbsp; & nbsp; & nbsp;Guess what? Suddenly you are your own country.
& nbsp; & nbsp; & nbsp; & nbsp;That may sound silly -- but let's say that China, Russia, and the UK all decide that your bedroom, right now, needs to be its own country. Not only are they willing to go to war to make that happen, but they will use every form of embargo, sanction, and economic influence to bankrupt the United States if it doesn't recognize the new sovereign territory of /u/DeySeeMeRollin_'s room. If faced with annihilation, it's possible that the United States may say, "Well, would you look at that! It is a country!"
& nbsp; & nbsp; & nbsp; & nbsp;Likewise, the second that the rest of the world stops supporting you, and there's nothing keeping the United States from annexing your country back into itself, then your territory no longer exists.
& nbsp; & nbsp; & nbsp; & nbsp;In the end, Countries are lines in the Earth that exist so-long-as the people within their boundaries have the ability to defend them. So while Arab nations may not recognize Israel as a country, they sure treat it like one... otherwise they would find themselves in a war against Israel and many countries who **do** recognize Israel. On the flip side, you have regions like Hong Kong which are established, near-autonomous governments... yet few countries will recognize them as independent because they don't want to disturb China, which does not want it recognized as independent. | a7ca74ab-0e8a-418d-8b4c-46b3e7684f12 |
22eq8o | Why does English no longer have a strong culture of poetry? | Perhaps the definition of "poetry" is too narrow?
I find the song lyrics of many bands and artists, and some of the dialogue of the greatest movies and TV shows, to have all of the same literary qualities as great poetry.
Just because the "poem" as a standalone expression of art is not as popular, does not mean that poetry itself is not alive and well. | 9c206b2d-5fa1-4785-b307-c13e97daeb71 |
3n03mn | What happens to our bodies after we're buried? | It depends on the climate where the body is buried. In extremely dry places there have been almost perfectly preserved bodies found after thousands of years. In wetter climates, in a strong wooden coffin, it's more like 10-50 years depending on the type of coffin. | 2897ea9e-1721-4e4c-9d4e-1e38fb10e7b1 |
58va0u | when doing deep breathing exercises, why do we breath in through the nose and out through the mouth? | A guy asked my football couch back in high school why he always yelled "in through the nose out the mouth" when we ran during the start of practice. He told us one day to reverse it, half the team passed out before the first mile was done. | ab4d0e0f-4d85-4833-9e5b-2a6c053427a8 |
51z27n | What causes the urge to fidget? | Its a natural reaction through your nervous system little impulses and such almost like putting electricity through say a wet noodle, makes it move about.
There's also a biological and evolutionary method, basically if you sit still for too long blood begins to pool, veins and arteries are cramped and clenched... So the more you fidget the less of a risk there is for developing a blood clot. Its basically a mini survival instinct.
When its cold, fidgeting and shivering causes you to keep warm through movement and keeping your blood circulating. The reason this works is the same reason fidgeting helps you from forming a blood clot. | a1df1157-8dd2-4b36-b29c-a150cc8ddec8 |
27hkq0 | What's happening when my muscle visually twitches? | If you mean like a spasm then it's an electrical signal sent to your muscle. Which leads to why was it sent. That is the real mystery. | 7086634c-7b3b-41b5-acf7-137b2b7723ed |
64gzts | Why is it harder to swallow nothing in quick succession compared to swallowing liquid/food? | The muscles in your throat have to contract more when there is no food to push against, meaning each swallow involves more muscle work/movement and takes longer to complete. | 144380b7-20db-4939-8a78-5d9660f38e32 |
5csoey | Why is it called an emergency brake if most people only use it for parking? | In the UK it's called a handbrake. Although in some cars it isn't hand operated. With an auto transmission most have a transmission lock when in park so the car is unlikely to move. The foot operate brake pedal is usually hydraulic. The parking or "emergency" brake is cable operated. If the hydraulic brake servo fails, i.e because the engine has stalled, you can use the hand operated brake to stop the vehicle. | 443d5ec9-d521-4fc5-aaf4-98c0f4b68336 |
2jt3fk | How do certain items like game consoles and apple products, have a fixed price which does not differ between retailers. | The authorization to sell a product is (can be) done via contract. Part of that contract can be that you cannot discount below MSRP, or can dictate the ways in which you can, how much you can etc. So..if you want to sell Apple products, you have to live by their distribution agreements and policies.
This isn't a limit on competition for the price of the product (the iphone is not a competitor of the iphone, even when sold at different stores). If apple were to collude with samsung to fix prices, that would be a limit on competition. | 4944d7c1-2c2b-4083-ad5b-2b5f01bf176f |
4xb8bk | Why isn't it possible to reuse candles with the used wax? | You could take any leftover wax and reform it around a new wick if you wanted to. But most of the wax is gone because that is what actually burns. The wick is just a tool for keeping the fire close to the wax and for bringing the wax up to the flame like a straw. | d85a0f12-cf88-4624-a50e-a0dfdf4dbbcb |
18xcu2 | Guy Debord's concept of the 'spectacle' | It's like when someone is getting their picture taken just for facebook. The person does not act naturally but rather how he wants to appear to be.
This translates into other aspects of life as well. The relationships to things have become represented by images in our heads -they were put their by advertising and film etc. It's like when you go camping and you feel like your in a beer commercial, or when you try to be a character you like at a party. The real is destroyed and is replaced by a representational image.
You should also look into Jean Baudrillard. His famous line "The Image has murdered reality" goes well with Debord. He likens our world to a story where a map is made that is so life size that it replaces the real thing underneath. Only it is not as real -it is rather more like a commercial or Disneyland. While we live on this representational map, the real world underneath begins to die. Or rather our connection to reality is cheapened and cliched and stereotyped.
Edit:Horrible grammar | db17bc29-3f17-456e-af7d-4caaeec721b9 |
4pg8ge | What causes "pins and needles" in feet and why? | It's pain from return of circulation to the nerves. If you sit or lie in certain positions you can occlude the blood supply to a limb, or just to its nerves.
Once circulation is returned they send out signals of distress to indicate a potential problem. When the blood has had time to oxygenate the tissues and remove toxins they go away. Flexing the area improves circulation and solves this quickly. | b6f4e4ac-c80f-46ad-8714-f8ce3e595b65 |
22os3l | Why is it so difficult to have automatic translations? | > I know it has something to do with context and the different meanings of words
This is pretty much it. When you use the word "crown", how do I know if you mean a "fake tooth", "the thing that a king wears on top of his head", or "the top of a hill". It's very hard for computers to pick up on context. So if I say a phrase like, "that is tight", the computer doesn;t know if I'm talking about "something being cool" or "something that is bad fitting".
EDIT: And we don't have a limited amount of phrasal verbs and idioms. Language is a living thing, it changes all the time. This is the reason that words and meanings are constantly being added to Websters dictionary. | 6908946d-429d-46b2-b666-78756c697142 |
3v2hyf | On a computer why can the cursor be hidden when moved all the way to the right and bottom but hits a "wall" when moved to the top or left side of the screen? | because its only the very point that's your actual cursor. the rest is just a graphical representation to help the user. Thats why you can drag it "off" the right but not the left | e3b8c4b1-2c38-4f54-bf28-680d7c2a53e8 |
4iwaik | How does YouTube's auto-generated subtitles work? | Google took hundreds of hours of accurately subtitled video and fed it to a machine learning program that linked sound snippets to written words statistically. Then they had it run through YouTube matching sounds in videos to words, creating subtitles. They then flagged incorrect subtitles and fed that information back into the program. They continue to do this, refining and improving the program over time. I didn't actually look any of this up. But I'm familiar with the technology, and it's kind of what Google does. | 7348e76f-3e06-4aec-8cea-9ccfa732fdd5 |
2k3rxb | How do corporations let themselves get to the point where they need to close 10s-100s of stores and lay off 1000s? Shouldn't they scale back slowly/over time? | For large corporations 100 stores is a little at a time. Closing stores actually costs money, it is more efficient to cut off 100 property costs at once | 811601d3-9dd7-434b-aeff-712f264af8ab |
3zvvqv | Why do certain vibrant colours make your eyes hurt when looking at them? | Ever since the blue LED x-mas lights came out I have called them "hurtyoureyes" blue. I wouldn't even mind a ELI25 as to why they are so vibrant. | 77e9c261-f99f-4e88-b518-67bd1be8f834 |
3j57zt | Why are there different grammar/spelling rules for "It's" and "what's"? | "*It's*" actually means "*it is*" even though lots of people use "*it's*" to indicate possession.
For example, the sentence "*the dog grabbed it's ball*" is grammatically incorrect because what you are actually saying is "*the dog grabbed it is ball*" which obviously does not make grammatical sense.
Instead the sentence should be "*the dog grabbed its ball*" - which is the correct way to indicate possessiveness in this case.
In the case of "*what's*", it can only mean one thing ("*what is*"). It can't be confused with a possessive *s* because *what* is not a pronoun.
Therefore, if you type something like "*whats*" instead of "*what's*", that's considered more like a spelling error / typo than a grammatical mistake. It's not that you're completely changing the grammatical meaning of the sentence, you're just not typing the word(s) in correctly. Some programs may also expect you to write "*what is*" as two words instead of "*what's*" because the latter may be considered too casual/informal. | 50524b24-8cf0-41e4-9768-0c8a8b710e61 |
4j5ndf | Negative gearing and the Australian real estate market | Rich investors bought property via bank loans and rented them out. If rent income is more than the interest expense on the bank loan, they generate a net income and so pay tax on it.
However, when rent is less than the bank loan cost, the investor makes a loss. When then computing their tax for the year, they can net off that loss against other income (say, from their job), reducing the tax they pay.
People get annoyed at this because of social reasons - rich investors can buy all the houses and this hurts first time home owners and in part, fuels the housing bubble/irrational pricing of houses. Its further annoying that the investors are able to decrease the tax bill on other income they earn, from these property based losses.
Finally, it is kind of annoying because it is these particular interest based loans (i.e. the investor does not pay off a normal mortgage, but only the interest) which leads to these kinds of earnings/tax manipulations. (A normal home owner would not be making an income profit/loss on property in the same way, so wouldnt have an impact on their taxable income.)
tl;dr rich get richer. this time very much at the expense of the 99% | b0c16bfb-7948-43a7-836a-e7dc84362658 |
7w65uu | How did the first being(creature/species) came into existence? | There is a lot of debate on the subject. And it very strongly depends on what you define as a creature. Evolution from microbes and proteins in the ocean is the answer to where larger creatures come from. Where the proteins came from is up for debate. | a9f9b25a-1de1-4017-9f73-12fdc0d6ee2f |
5elzmx | Why do tuna & salmon have such a distinct taste? | I think you're a bit wrong about white fishes : some white fishes have very distinctive taste and/or texture, like ray or flounder, for instance. I think the reason we find some white fishes indistinguishable is because of the way we eat them : boiled with a lot of sauce (and then the taste we have is usually the one of the sauce, not of the fish), or as breaded fish. Eating them raw, for instance, would probably foster our taste in a more refined way.
Salmon is a special fish, which lives both in sea and river, has pink greasy flesh. You say it's easy to recognize, but would you be able to differentiate salmon and trout, or salmon trout ? They may taste the same to you, because they're of the same family.
Same with tuna. The reason you distinguish tuna from salmon from "white fishes", is probably because they're of different fish families. (white, red, pink), but not so many pink /red fishes are as available as white fishes. Should you be offered the same variety in pink and red fishes, they would probably taste the same to you as well. | d5e8ed53-9932-47bc-aca8-532208bac4bf |
47h6t3 | Why does Amazon allow users to write reviews for products they have never purchased? | If I'm not mistaken you can see if the reviewer has purchased the item or not so you can take the review itself with a grain of salt. They allow people to do this because they realize people can purchase items outside and Amazon, they want to give these people a voice as well, whether it is to warn someone or praise a product. | 94df5a43-e99a-4ec5-9d4b-7d5686676610 |
7sqsfw | How do surgeons prevent major blood loss during coronary artery bypasses? | It is clamped. The heart is then stopped with a potassium solution (many potassium solutions such as KCl can cause cardiac arrest, which is used in lethal injections!). The sewing of another vessel is performed, then the heart is eventually started once again. | 309c1f5a-111d-42cf-82ba-6046d74af533 |
3r8lkg | What happens in the brain when you're desensitized? | Basically, anything in your brain happens because some stimulus is fed to neurons and if the stimulus is above a certain threshold, the neurons fire and cause your response.
If you - for example - take cocaine, your brain releases lots of dopamin which makes you feel good. However, you body "knows" that this isn't normal and tries to normalize the "feel good equilibrium" again. One way to do that, is to react less to dopamine. Which means, to get the same high you need to take more cocaine next time. | a467b9a4-6a1f-4392-94f6-736d58a70fff |
5sfwwq | Why were Milkmen once a thing in America, and why did they stop being a thing? | Milkmen have been a thing since long before refrigeration existed. You can even see it in things like "Fiddler on the Roof" which is set in the early 1900s and it was a well established job for a long time before that point.
The local dairy would deliver milk every day to people who could not raise their own cows (such as city folk) and they would also sell things like butter to them. After refrigeration was developed the job still remained a fixture for a few decades because stores were not built to have large refrigerated and freezer sections. But after enough time passed new Stores were designed to have a lot of refrigerated stuff and people started to buy their milk from stores and the home delivery model became too expensive for the dairy to use as it used too many workers. | 7a481d7d-02ac-44c6-90c8-dd7404285690 |
48lop5 | Why do our bones crack? | Do you mean like when people 'crack' their knuckles?
If so, they're not actually cracking. It's the space in the joint expanding and synovial fluid rushing into that space. That creates the feeling and 'popping' noise. | 1b336d29-9b54-4aa7-b359-6e2181a2a873 |
230uxq | How do cats always land on their feet | They do it by simultaneously manipulating the moment of inertia of their front and back haves. SmarterEveryDay has an excellent video with slow-motion explaining this [Cat Physics](_URL_0_) | 6d5ae9b7-e98c-4607-aa6a-b68d6ed331a7 |
3wz0nq | What will AMD's GPUOpen allow developers to do? | Right now, drivers and applications for video cards is like the Dorothy and the Wizard in the Wizard of Oz. When you compile or use an application, you are speaking to a giant head that only tells you things it thinks you want to know or access. The difference from the metaphor is that you KNOW there is a man behind the curtain, but you can't pull back the curtain to see HOW he is doing things or tell him to DO things he doesn't want you to do.
GPUOpen is giving developers the ability to DIRECTLY access a lot more on the card than before. Dorthy beelines to the curtain, whips it back, and starts pointing to specifics dials and knobs for the wizard to pull or turn. There will have to be some functions that has to be hidden (a subcurtain?) to stop people from just nuking their GPU remotely but if AMD comes through on this, we could see a lot of improvements in GPU heavy applications like video encoding, folding@home, bitcoin (lol), and of course games. | e1ad5b5b-a2e8-443a-adb2-75a192e1bc37 |
52ose0 | Why do we feel nauseous when we watch someone else vomiting? | In the social environment in which humans developed if one member ate something poisonous then likely the others did as well. It would then be helpful to also vomit to avoid being sickened too. | 0efb072d-5493-44f7-b6a7-0589b99ca658 |
2e8kyy | The concept of women "syncing up" their periods. | They don't, it's a myth.
Considering cycles range from 25-30 days and can last from 3-9 days (sometimes more) in duration, they don't actually sync up, they just gradually overlap for a time and then they go back to being at different times.
Think of it like being in the left hand turn lane. You watch all the blinkers and for a few seconds they seem to be in sync, but before long they go back to blinking at different times due to duration. | 2abcff38-6714-4f55-acad-7c63cd196ae1 |
158g4u | Why is the NRA so powerful? | Any special-interest group (e.g. National Rifle Association (NRA), National Organization for Women (NOW), United Auto Workers (UAW)) gains power from membership.
The more members an organization has, the more money it has to promote its cause and the more voting power it can wield at the ballot. | 063fa8a9-570e-44c4-a82b-67193fd553aa |
oxos3 | Venn x Euler Diagram, what is the difference? | One of them is pronounced just as you expect it to be. | 381f0164-10ef-476f-b3b0-0317fa75d31f |
3btuom | how do auto-dimming rearview mirrors work? | It depends on what you mean by "effective". The manual tip up mirror uses a wedge prism to either reflect almost all of the light or just a fraction from a lightly silvered front surface. This system is totally optics, and has infinite resolution. It's hard to beat simple physics, but it's not automatic.
The auto-dimming mirror uses electrochromism. A special substance in the mirror, a layer between the front surface and the reflective surface, changes color from mostly clear to mostly grey when 12V is applied to it. This layer isn't as precisely made as the LCD in your computer display, it only has one "pixel", and this can cause artifacts. If you see a distorted image, the electrochromic layer is damaged, take it back to the dealer and get a new one. It you just like the look of optics better, well, too bad, Marketing at the car companies likes electrochromism better. Maybe a replacement mirror?? | a30414a3-35cb-4a77-a1d5-81de3d5fb24c |
1diule | Why isn't it possible for a counterfeit bill to perfectly emulate a real bill? | It is possible.
If you had access to every piece of equipment that the government uses to produce currency, you can make the exact same currency. They do make it extremely hard to get certain materials and certain machinery (presses for instance) that makes this hard. | 28dfbd36-715c-4461-8551-75e00259b1c8 |
336azx | Why are benzodiazepines (chill pills) so bad for you, but work so well? | Benzos really aren't that bad for you, except for the addiction risk. They're particularly safe when compared to what used to be prescribed beforehand, usually barbiturates. (Mixing barbiturates with alcohol is a VERY easy way to die.) You actually have to go well out of your way to manage to OD on benzos.
Anyway, as far as benzodiazepines go, Ativan is pretty weak sauce, so if you're only getting occasional scripts for that or Xanax and the scripts don't even have refills on them, you aren't running any real risk of addiction, so I wouldn't worry about that.
Why hasn't anyone come up with anything better? Just bad luck. They're always trying; a drug company that could come up with something to treat anxiety that actually *worked* and didn't have any sort of addiction risk would make them literally billions in profits. You may want to check out /r/nootropics too; there's lots of GAD sufferers there always keeping an eye out on the latest research. | cbc94f13-d292-4d7a-842e-980c3daa1e63 |
2nfqfi | How do hard drives/flash drives store information while they are not connected to a power source? | Flash drives work off of individual flash cells. These can be simply thought of as little buckets that can store electrons. When they are connected to the computer (and thus powered) they can be instructed to fill or empty these buckets and the amount of charge (electrons) in each bucket can be measured. When disconnected from power the electrons are not allowed to move out of their bucket, so the data stays there until the device is supplied with power again.
Flash cells are cool in the fact that in many cases they aren't actually a binary device. With many computer components you think of any given "bucket" as being either "empty" or "full," or of a line being "high" or "low," or a switch being "on" or "off." This either/or system means that you can represent numbers as a string of ones and zeroes, which turn out to be very nice to work with at the lowest levels. Flash cells, though, can be "empty," "mostly empty," "mostly full," or "full," thereby having 4 states. Some cells even support 8 levels. This approach allows one cell to store two bits of data (or 3 for the 8-state cell). You can see flash memory labeled as "SLC" if it only uses "empty" and "full," or MLC if it uses 4 states and TLC for 8 states (these are single, multi, and triple level cells, respectively). SLC flash is more reliable, but MLC and TLC is cheaper due to the lower number of cells needed to store the same amount of data.
********
Hard drives work off of magnetism. If you expose a piece of iron to a magnetic field then you can give it a little bit of a residual magnetism. You can test this by dragging a steel needle across a magnet several times then setting it on a floating cork; this will give you a rudimentary compass. In a hard drive instead of using a permanent magnet and a needle it uses a platter of magnetizable material and a little bitty electromagnet that can be turned on to expose a little portion of the platter to a magnetic field. This read/write head can also detect the residual magnetic field.
Note that the platter itself which is actually holding the information is a completely non-electronic device. The hard drive needs electricity to spin the platter so that the head can be over the right portion of the disk, and to power the electromagnet and its control chips, but the disk itself is a non-electronic device, just like the needle in the previous paragraph. | 3ce6755c-a3d4-426c-a0f5-0fbbc0f52ac0 |
65be04 | Why was torture used in the past? | If you are asking from a moral standpoint, this was never a factor to the people looking for information, or to do experiments.
Physical torture, or the threat of physical torture could coax info from somebody much the same as psychological could.
And for experiments, definitely a controversial topic, but it has gotten us plenty of valuable medical break-throughs. | 7419c8d2-60d8-4db1-b3df-fe34c7498341 |
2sfq6i | How does closing our eyes signal to the brain that it's time to shut down (sleep)? | It's not necessarily so that closing your eyes makes you sleepy. Often it's the other way around: you feel and urge to close your eyes when you are tired and sleepy. Bu in a way it's like two sides to a coin - the two phenomena are interconnected and interdependent on eachother:
When you close your eyes very little meaningful information flows from the retinas to the brain. The stream of visual impressions stops. Quite a large part of the brain is at any time occupied with decoding and interpreting visual information. By stopping the flow the activity in the brain is diminished and this gives the brain "rest" (couldn't come up with a better word just now).
Also, as the retinas stop being exposed to light, both by closing the eyes and by the sun going down and darkness falling in the outside world, there is a signal from the retinas of the eyes, through some fibers of the optic nerve, to the pineal gland, a small gland buried deep in the brain. This signal (light has become darkness) gives rise to an increased production and release of the hormone melatonin which makes us sleepy. This is not an instant process, but happens over the course of maybe 15-30 minutes. Interestingly some people who are blind due to injuries or malfunctions in the central nervous system may still have functioning retinas that can give signals to the pineal gland through the optic nerve so that these people, even though they can't tell through sight if it's light or dark can have a circadian rythm (at least partly) that is controlled by the light conditions in the outside world. | 69f2c313-e991-4fba-acdf-9e3501346359 |
1s43ip | Why are Russians considered "Eastern European," when they're technically North Asians (geographically). | The western boundary of Asia, in this area, is the Ural Mountains. Most of the major cities in Russia (including Moscow) are west of that, and therefore are part of Europe. | 051645ee-afa7-46b5-ab42-131ec855ba68 |
21w2lf | How did we get such a gap between server's pay and regular pay? | OK let's just all relax here and remember what we're talking about.
Being a server appears easy, I agree, however being a GOOD server is much more difficult. Just like any service industry (phone support, hotel hospitality, reception, etc.) there's a massive gap between what is required to do the job, and what it takes to excel at the job. A server who shows up for their 15 hours a week for weekend beer money is putting in the minimal effort, but a server who is pouring their heart into their work does indeed have a demanding job. The difficulty is not memorizing orders, or physically running food, it's the multitasking, managing the pace of the meal, reading people and having the skills to recognize what sorts of parties will be responsive to different sales pitches, hence maximizing the income from the table, but also the enjoyment of the guests such that they return, and doing all this, by the way, while often being at the front end when things go wrong.
All of that being said, the reason pay is so much lower than minimum wage is not because the job is easy. It's because over time the gratuity, (which should be an OPTIONAL sign of EXCEPTIONAL service) became commonplace, and higher and higher in amount (5%, 10%, 15%, and now under 20% is considered, in most restaurants, to be an indication of sub-par performance). With that, waiters and waitresses were receiving a high amount of income, and were regularly not claiming it for tax purposes (though legally it should have been, so that's technically tax fraud, and most restaurants now automatically claim credit card tips since they're tracked), so legislation was passed to have a separate state-to-state and federal minimum wage standard for these industries which "relied on tips".
But it's out of hand, in my opinion. When I was serving in RI in 2010 my hourly wage was $2.89. But my tip average was so high (because I was one of those servers who cared) that the taxes taken out of my meager paycheck were always higher than the paycheck itself, and I never once received a deposit, eventually OWING taxes come April 15th. As far as I'm concerned, server minimum wage should be increased to the same standards of normal minimum wage, and society should return to the gratuity as a symbol of exceptional service, not an expected addition to the bill simply out of necessity. But you try and tell Society to Change and see how far it gets you... | a86ab370-2a9d-42a3-acbf-4174b5ae0008 |
2zug6g | Why does weed make some people super paranoid and others not? | No, it's more a matter of how the user interprets the experience of being high than something about the high itself. It has a lot to do with the user's state of mind going in, how they generally feel about themselves and their lives, and how they feel about the people around them. | f6566698-c98b-44cb-8fe4-48cafeb4e984 |
3wk1lp | What's the psychology behind serial rape? Do serial rapists genuinely think they won't get caught? | Not an expert, but I'm going to guess that getting away with it once leads to the belief that he will continue to get away with it.
I knew a guy who was running some type of credit scam through his employer (a retailer). It began as 100 or 200 dollars. When there were no consequences, it was easy to do again and again and again. When the owners finally figured-out what was going on an who was responsible, he'd frauded more than 20k. | 3ecf5f6b-deee-4a62-b818-cf8df612c1f3 |
5l8foa | why do pro gamers retire in their early 20's? Do your reflexes really drop so significantly that early in life? | Several reasons:
1) you don't really make that much money. Only top players make the big money. For every guy making over $100k a year, there are hundreds who don't. It's kind of like the acting industry. The top 1% of actors make huge money, the other 99% are broke. At some point these guys realize they will never be a top player and they can make more money doing something else.
2) it not all fun and games, it is a job. These guys play the same game every day for 12+ hours a day to be as good as they are. Just imagine that. It would get real boring, really quickly. Also, they are not playing to have fun, they are playing to win. They only get paid when they win, so there is a lot of stress to win. Even if these guys are on contract with guaranteed pay, they are always at risk of losing that contract if their performance slips or if the team finds a better player to replace them.
3) medical reasons. Yes, you read that correctly. Carpal tunnel syndrome is real and extremely painful. Using all those fine motor skills in the hand can actually damage the muscles and tendons in the hand. Our hands were not designed to use the fine motor muscle constantly for hours on end. Also, the pressure and constant stress to win takes a physical toll on the body.
4) games change. Most professional gamers specialize in 1 or maybe 2 games. After a few years, and as new games come out, older games stop getting media coverage and the prize money for their tournaments drop. In some cases, tournaments cease to exist for that game and there is no more demand. If you are lucky, your chosen game will have several iterations (like Halo or COD) that only have minor changes as each new version comes out. If not, there is no guarantee that you will be as good at a different game.
5) At some point, you want a normal life. You want to be able to date, get married, have kids, etc. You need a stable career and free time to do this. | f310d7f5-c178-4281-aa4e-c7564ff9fd07 |
3id506 | In the Jared Fogle case, the charges always emphasize that he "crossed state lines" to commit certain crimes. Why does this matter so much? | The fact that he crossed state lines makes this a federal case, rather than a state case.
Federal courts have a few different rules and punishments and such, and a lot of resources for the investigation. From a legal standpoint, it's a pretty big difference, since he'll be in a whole different court and prison system. | 8cd3bbe4-ac65-4f24-ab49-c069da89e5ce |
5prs0r | What is the "Deep State" in the U.S.? | Deep State refers to the people and organizations that *actually* control the politicians that control the government.
Who/what the Deep State is depends on whom you ask. For some it is the [Military Industrial Complex](_URL_0_); for others it is a collection of [oligarchs](_URL_1_) and plutocrats.
Others use the term to refer to the large number of bureaucrats who make policy that has the force of law, but neither the policymaker nor the policy that they come up with is from an elected official.
Like many terms used today, it has no clear, single definition. | 7874dafa-e3fa-440b-b45c-2a6eee914d1e |
7au0yi | What does the Kantian phrase 'end in itself' mean? | That's not just a Kantian phrase, but it means exactly what it says. End in this context means purpose or cause. It is an end goal in it's own right. It's not a step to some other goal (means to an end).
Art as a hobby is often viewed as an end, something people do because they derive enjoyment from it with no goal beyond that. Art as a job could be viewed as a *means* to an end. The end goal is to make money, art is how that is achieved. | 9abf9bae-d933-409a-8545-c2b8513e7a68 |
1o8b0j | Why isn't it false advertising to advertise a price, to then add inseparable, mandatory fees? | They always mention the fees when advertising their price.
Usually it's in small print. Or if it's spoken then they say "prices starting at $49.99". | f768fca7-2bf1-4967-990a-8e9ffc811883 |
291h97 | Why is the alphabet in the order it is, theoretically, does it have to be in this order, and why cant it be in just any order? | There is no reason for it to be in the order it is.
There is even less reason to change its order. | b0e94136-39f3-49cb-93f8-4ee4647774ee |
23yee7 | Why does sound seem "louder" during the night as opposed to during the day? | A few things - how much ambient sound is there at night? There are probably fewer cars and fewer people out, so with less background noise, the TV sounds louder because it doesn't need to compete anymore.
Another possibility is that in the darkness, your hearing sensitivity increases to compensate for the lack of sight. I *think* this might be an evolutionary trait (e.g. people who go blind whose hearing sensitivity improves to compensate). I believe there have been studies/experiments on this insofar as hearing increasing naturally in darkness to compensate for lack of light/eyesight.
But I think the first reason is probably more likely. My NYC apartment during the day is always noisy because of the street outside, but at night there's almost no car traffic except large trucks, and the TV becomes much easier to hear at very low volumes. | e99103a8-6721-4816-a6da-8c6eb264bf5e |
2dyu21 | Why is it that Syrian rebels who are backed by several nations are waging war in sandals and Nike Jacket, whereas ISIS, which is not known to have any strong international funding, is tricked-out with EU/US uniforms and arms? | When ISIS took a major chunk of Iraq in their initial strikes and tried expanding their Islamic state, they had taken over a key Iraqi Army base that US/British/Australian forces had left military gear intended for the Iraqi Army because it was "theater gear" (meaning it was there for the initial invasion, upkeep and further security of Iraq while those forces where there well after the toppling of the dictator Saddam Husain, and to be given to the US and British trained forces which would then inherent the gear).
Shortly thereafter, in the beginning of July, they laid siege on the Bank of Mosul in the Nivenah Providence and allotted their terrorist organization somewhere in the area of $400-million worth in gold and other financial resources, making them the richest viable terrorist organization next to Exxon and Comcast (I kid, I kid, you can negotiate with Exxon).
So... That's pretty much it in a nutshell.
> Religious Extremists
> Take over the City
> Get big city money
> Expand arms and influence through fear and public executions
> ISIS ATTEMPTS creation of Islamic state based on false views of Islam and become Earth's recipient of "Assholes of the Year Award". | d98222a3-d856-4261-a3dd-705799102987 |
2s81xj | Why Hotels need your address and phone # even if you pay by Cash? | Because if you trash the room or something happens they still need a way to contact you. | 23b67d99-7330-43cd-b824-bcaa411079e3 |
3hfo7l | Does 'closing your eyes' when fatally wounded have any impact if you die or not? | It's not more of a staying conscious at the time of your death, it's literally stay with me, don't give up, please show me you can still make it. I'm not a 100% accurate on this but when a person gets an injury, sometimes it is important to stay awake for the body to not get into something - I forgot if it was shock, or something else. | 8aa6d806-6102-48fc-afdd-d536685d9985 |
65byhh | how do african warlords work? | > What are their motivations?
Money and power, mostly. The details differ, for example some want to topple a government and rule the country, some have religious reasons (for example the infamous Joseph Kony), some just want luxury and women.
> How do they get people to enlist in their private armies?
Same way normal armies get people to enlist. You offer them money. The areas where Warlords can operate are usually very poor with weak governments. High unemployment and low wages. If working for a local warlord is the only way to get a regular paycheck (as well as pillaging) and by consequence, to support a family, it is not a hard decision.
Some may also join for revenge. "Members of that tribe have killed your parents? Hey, join me and you can take revenge!"
Also, many warlords use forced conscription. They walk into your village, tell you "You fight for us now or you die!" give you a rifle, and send you to fight somebody. When you have the option of probably dying against the warlord's enemies or certainly dying for betraying him, it's not a hard decision.
Then we have child soldiers, the worst type of getting soldiers. You take young children, give them drugs, and train them until they know no other world than one of violance and war.
> How do they get financing?
Different ways. Some collect protection money from the people they control. Some may control natural resources such as oil, rare metals, or diamonds. The term *Blood Diamond* became popular due to this.
They might also kidnap people and ransom them for money.
> What do the sovereign state that the warlord operates in think of them?
They hate and fight them. After all, warlords are a direct threat to the country's power in its borders. However, warlords don't operate in strong prosperous nations, but weaker, poorer countries who can't always defeat them. Often (especially in earlier decades, it's fortunately getting better), the country itself was governed by a dictator who only differed from the warlords by the fact that he gained control first.
However, there might also be countries who tolerate warlords as proxies for ethnic cleansings, attacking other countries, or something comparable.
Fortunately, as many African countries are getting richer and stabler, the potential for warlords is slowly getting smaller and smaller. | 7d720c51-a0aa-4a40-9b78-f60a947766fd |
1j1zte | Why does the dark side of the moon never face the earth? | Sometime the dark side of the moon *does* face us. It's called a [New Moon](_URL_0_). I believe your question is about the [far side of the moon](_URL_1_). | edc6e6ca-ca8b-4b7e-afae-10dcafa88e44 |
7i9b7z | What is an Oracle and why does it make solving the P vs. NP problem so much harder? | The oracle is just a metaphor used to express nondeterminism in an easier to understand matter.
P is the set that contains problems whose solutions can be found in deterministic polynomial time. Just think of that as a special kind of fast.
NP is the set of problems whose solutions can be found in nondeterministic polynomial time. There is no known fast way to find the solution, but if a magic oracle gave you the solution, there is a fast way to verify it is correct.
If someone were able to find a fast solution to NP problems, P and NP would be the same set. None has been found yet.
If someone were able to prove no fast solution is possible, P and NP would be different sets. No one has been able to prove that yet.
Most people believe P != NP, enough so that most of modern cryptography is build on that assumption. But there is a tantalizing possibility that there is some fast solution out there that would make P = NP, greatly weakening computer secuirty world wide. | d34ff6d4-ce01-4923-b600-e81f37a18772 |
37bm7z | American Baseball leagues | The other answers have the basics covered, but I'll expand on the Minor League system. There are four basic levels: Rookie, A, AA, AAA with Rookie being the lowest level and AAA (called Triple-A in conversation) being the highest. Each Major League club controls minor league clubs at each level and uses them to develop their players. They can move any player in their organization up and down a level as they see fit, so long as they don't exceed the maximum roster sizes for each club.
EDIT: Forgot about the draft
The draft is the annual meeting of Major League teams to decide who gets to sign what young players. This may be hard to understand for someone who's not American, since I believe we're the only country where amateur athletics and education are so closely associated, but our high schools and colleges are the biggest development centers for young athletes. Once a year, the Major League clubs get together and pick, in an order determined by their results from the previous season and other factors, which high school or college players they want to sign. If a team drafts and signs a player, then they control the rights to that player for a certain amount of time before that player is free to sign with another team. This system introduces some measure of parity to the league since the worst (usually poorest) teams get to pick earlier and retain the players that they pick for a few years without getting into a bidding war with larger, richer clubs. | abdbc285-f19c-48af-bf30-6e706332db36 |
253f0z | How does drafting work? | Drive down the highway with nobody around and the radio off and listen to the wind. Then do the same thing but behind a diesel truck and it will make sense. You'll also get better gas mileage.
Drafting or slipstreaming is a technique where two vehicles or other moving objects are caused to align in a close group reducing the overall effect of drag due to exploiting the lead object's slipstream. Especially when high speeds are involved, as in motor racing and cycling, drafting can significantly reduce the paceline's average energy expenditure required to maintain a certain speed and can also slightly reduce the energy expenditure of the lead vehicle or object.
On the faster speedways and superspeedways used by NASCAR, ARCA, and at one time the IROC series, two or more vehicles can race faster when lined up front-to-rear than a single car can race alone. The low-pressure wake behind a group's leading car reduces the aerodynamic resistance on the front of the trailing car allowing the second car to pull closer. As the second car nears the first it pushes high-pressure air forward so less fast-moving air hits the lead car's spoiler. The result is less drag for both cars, allowing faster speeds.[2]
Handling in corners is affected by balance changes caused by the draft: the leading car has normal front downforce but less rear downforce. The trailing car has less front downforce but normal rear downforce. A car with drafting partners both ahead and behind will lose downforce at both ends.[2]
Similar to the "Belgian tourniquet" in cycling, the "slingshot pass" is the most dramatic and widely noted maneuver associated with drafting. A trailing car (perhaps pushed by a line of drafting cars) uses the lead car's wake to pull up with maximum momentum at the end of a straightaway, enters a turn high, and turns down across the lead car's wake. The combination of running downhill and running across the zone of lowest aerodynamic drag allows the trailing car to carry extra speed and pass on the inside of the leader.[2]
Drafting was discovered by stock car racers in the 1960 Daytona 500, when Junior Johnson found that he could use drafting as a strategy that helped him overcome the fact that his Chevrolet could not keep up with other cars, allowing him to win the race.[3] Like Johnson, other drivers found they picked up speed running closely behind other cars; and as they experimented they found that a line of cars could sustain higher speeds and/or use less gas (resulting in fewer pit-stops) than a single car running by itself.[2] | 49bc7e88-e8c9-4ddf-8977-95afffbc190c |
1vjyju | Why is pain "painful?" Why don't I like feeling pain? | pain is bad mmkay. it's how your body lets you know something's going wrong with it. spice is the plant's defense, so it wont get eaten by animals, since they're not stupid enough to eat it twice if it burns their mouth for half an hour after. | 83c16ad9-3602-4213-99c6-68ab8927947e |
3nam5p | Why does it seem that the common cold 500 years ago is much more lethal than a cold in the modern era? | You...can't really ignore those two things. Those two things are very important for modern medicine.
But *other* than those things: our diets are much better, so we have a lot more energy to fight off colds. Food is readily available, so if for some reason we're too sick to work it *probably* doesn't mean you'll starve to death (whereas the serfs working on subsistence farms 500 years ago literally worked every day for their food). That also means you *can* choose not to work, so you can take it easy and avoid stress that would make the infection worse. We have also eradicated other opportunistic diseases and generally keep much better hygiene, so we don't have to worry about secondary infections that will take advantage of an immune system weakened by the cold. We can identify infections much more quickly so if there *are* complications and the cold worsens to the point when it might become lethal, you'll get professional medical care more quickly (or, you know...at all). We do have a few anti-viral drugs that directly assist your body in fighting off the cold. Antibiotics don't fight viruses like the cold, but they *do* fight off bacteria that would, again, take advantage of your weakened immune system.
Um...we have temperature controlled homes, so we don't take on additional stress or the energy-drain of maintaining a healthy core temperature. We don't live alongside our animals (see "better hygiene"). | 5704d1bb-0726-4d50-97c9-d104e5060601 |
194kdu | Please, ELI5: Why do grape-flavored things (soda, gum, etc.) NOT taste like grapes? | I refuse to call it grape. It's purple flavored. | 2891b6ea-8456-4b66-8ebd-690c85c77151 |
1kgz16 | How software communicates with hardware? | It all revolves around a little-known yet valuable language to us computer engineers called assembly language (an industry standard is x86, you may have heard that somewhere). We learn this abstraction and the levels of organization of a computer in our introductory architecture classes. The story is long but usually begins with an emphasis on starting at the bottom at transistors and chips and going up to higher level programming languages.
Electronics are made of tiny atomic switches called transistor. For simplicity's sake, when a voltage is applied, the transistor produces a high voltage, what we call a 1. With no applied voltage, there is no output voltage, what we call a 0. The history of logic deals with a so-called binary system, where we only deal with 1s and 0s. Now transistors can be linked together to do basic binary logic operations such as AND, OR, NOT, and XOR. These are called logic gates and are extremely important to understanding how binary logic works. We can make large circuits out of various combinations of these logic gates, examples would be adder/subtraction circuits, memory storage units in RAM, high-speed readily-available memory called registers, and selector circuits called multiplexors that select one of two or more incoming signals. That covers the basic hardware.
Now the CPU is based on what we call a Von Neumann architecture. This usually consists of three major parts. The first is called the ALU (Arithmetic logic unit), it adds, subtracts, multiplies, divides, ANDs, ORs, etc whatever inputs come to it. It's our advanced calculator within the CPU, the thing that actually processes. The second part is the memory. This is your RAM, hard disk, registers, etc. The third unit is the control unit, and this basically synchronizes the basic parts of the CPU together to work as magical clockwork. All three pieces are what our programming language takes advantage of to compute things. In the memory, RAM and hard drives are too slow for the billions of reading and writing operations done every second by the CPU. For this reason chip designers rely on the high-speed memory of registers. They're temporary storage units that operate at the same speed as the CPU. Normally there are 8-16 of these per CPU which we designate R0-R7 or R0-R15.
Now onto the assembly programming. Unlike Java, where you can simply write A+B, an assembly language breaks these steps down into simple logic that the CPU can understand. I'm not gonna show how this logic is done because that's not important. A simple assembly language instruction would be ADD R1, R2, R3. Let me break this down: The first segment of this (ADD) is called the opcode. There is a bit of specialized software called an assembler that converts the word "ADD" to a binary number the CPU recognizes such as 1001. The CPU been designed in such a way that 1001 tells the ALU to add the numbers. The second bit (R1, R2, R3) are registers. We can't tell a computer to produce or "think" of two numbers. Using other assembly language commands, we program these numbers into these registers. R1 and R2 are called the source registers and R3 the destination register. Whatever numbers we want to add are stored in R1 and R2, and the sum is spit into R3. Now we can describe how the CPU will work. Say we want to add 5 + 2. we put the binary forms of 5 (101) in R1 and 2 (010) in R2.
In the RAM, the CPU reads the instruction called "ADD R1, R2, R3." The assembler converts the ADD into 1001, which the CPU understands to "add two numbers." The control unit turns on two silicon wires that go from R1 and R2 to the ALU so the ALU now holds two numbers 101 and 010 (5 and 2). Then it turns on some other wires that tell the ALU to add the numbers instead of subtracting them, multiplying, etc. So now the ALU holds the binary number 0111, or to us, 7. Then the control unit turns on a silicon wire that spits the number 0111 into the register R3. As a final step, the answer in R3 of 0111 can be sent to memory for storage. Thus, we've added 5 + 2 = 7.
Now there are more complicated assembly instructions that do other operations like subtracting, dividing, ANDing, ORing, etc. There are operations that can jump to other sections of memory for reading other lines of the assembly program. There are instructions that process registers and clear them, loading values into and out of the registers. x86 being a modern language also has instructions that can control peripherals like monitors, mice, keyboards, and printers. But to do so, the CPU has to "handshake and socialize with the devices" and confirm that the device exists and can understand the CPU's language, similar to asking someone in a foreign country if they speak English so that you can ask questions. Software that does this is called device drivers. The BIOS is a similar system, during bootup it talks with all the different chips, peripheral devices, and the CPU to make sure that they exist and are working. All this is done in x86 assembly. Overclocking programs and processes create and modify existing x86 code in BIOS memory so that instead of the BIOS telling the CPU that "we can operate at 2.5 Ghz, lets do so" these programs twist the code so that it actually reads "wait correction, 2.5 GHz is a slower speed, we can actually operate at 3.5 GHz so let's do so." That's how your overclocking would be done, and it would happen through x86 assembly language
Basically the magic of software-hardware transfer occurs in three places that many computer architecture engineers study: the control unit, assemblers, and advanced software called compilers, which take a higher language statement like A+B in Java and transform it into a simple assembly statement like ADD R1,R2,R3 that the CPU can read. Personally, my current job is to help design device drivers for printers. It's not complicated, all it takes is thinking in binary and logic, and a good knowledge of how a CPU's various parts interact. | 6c7a0405-807a-4f7b-b786-db899908e4d6 |
4cmkgi | Why are the names of oil companies that spill oil into the ocean plastered on the news, but not the party responsible for the California natural gas leak? | The sad truth is that the BP Oil spill got mass attention because it's a much more tangible event and it harmed animals. The California gas leak is equally or worse than the oil spill but I suppose that news isn't selling. I won't say there's conspiracies but some could easily say that parent companies of, say, CNN don't find it in their best interest to demonize big oil and gas unless they can sell it on something about saving the animals. | 3dc7ad0d-bba3-4859-aade-70582703029f |
2zyiey | Why can't people in the US sue individual police officers like we can doctors? | The state asserts "sovereign immunity". In other words, you can't sue the King (or the King's agents, etc.) unless the King agrees to let you. We don't have a King, but our government retains sovereign immunity.
There are many times you can sue the state even when it doesn't want to let you. Exceptions to sovereign immunity have been carved out of many laws and are commonplace, but one place it is not is in the exercise of police power. It makes good sense for this to be so, or everyone who was arrested would sue, and the police force would be unable to operate.
Typically the redress for issues with police misbehavior is through the ballot box, not the court system. The police are accountable to elected authorities, who can, will and do force them to alter their behavior and in some cases waive immunity so a lawsuit against truly egregious behavior can go forward. | d8046a12-cee9-4250-adfb-a5d5bca8b337 |
28i1ek | How can a 600W PSU supply 50 A on 12V, while the electrical wires in the wall would literally burst into flames at 50A? | A power supply pretty much conserves power, give or take a few losses.
So the output power is 12 x 50 = 600W, as advertised.
The input, from the wall, is at (say) 120V
So the input current is 600/120 = 5A, well within the capacity of a standard 15A domestic circuit.
Incidentally, the wires would not burst into flame at 50A, you would simply blow a fuse or pop a breaker. The whole point of fuses and breakers is to prevent this sort of fire. | 7ba7e8bc-1db5-4e5b-83a5-219e4066c715 |
6cd2ti | Why do spots stop hurting after we remove the puss from them? | For those of use who might not be aware, 'spots' is a term that aussies and brits use for pimples. | 0f550329-86ff-479f-a293-f35159bc8d24 |
6dv9lo | When and why did basketball hoops become such a staple for American driveways? | Basketball is the second (or third depending on the poll) most popular sport in the US. It is easier to set up a hoop for simply play and practice than it is to get space to play football or soccer, and far less than practicing baseball (even with a batting or pitching cage). This means it is a common recreational activity for active/semi-active families.
As for when it became popular. That would have been in the 50s-70s during the boom of suburbia. Cities would have public parks with full courts available, suburbia everyone had a driveway. | d20e24ac-5a92-42a5-bc4d-d289fabc7b54 |
3dswml | Why isn't Robert E. Lee viewed as a traitor? | He probably gets let off the hook for being reluctant to go to war and rejection of his military life after the war. He became president of then Washington College (Now Washington and Lee University) and said his greatest mistake was a military education. | 7d355af8-eb3c-4ba4-8b0e-f8117b371f72 |
2jyrlm | How Britain and America went from what could be described as bitter enemies to what could be described as best buds? | both countries have a deep shared cultural heritage that has proven to be a powerful unifier, overshadowing the brief periods of conflict and hostility that could have resulted in longstanding resentment. solidarity between the United States and the three major Commonwealth countries was further reinforced by entry of the United States into WW1 and WW2 as an ally nation. these two in combination has resulted in a special relationship that isn't experienced by, say, France, lacking the same cultural heritage. | 5c7633f1-7d39-45a3-ae6b-2f7ffb3b7b4c |
1enubm | Stereotypically speaking, why do men play baseball and women play softball? | It's not a stereotype, it's a fact. When kids are young, often girls will play baseball. But as they get into high school, almost all of them switch to softball (mostly because it is required). Then, when middle-aged (or younger or older) people (men and women) play recreationally, they generally do softball because it's less intense and physical.
The sports are very different.
Baseball, you always wear pants, the pitcher throws overhand and can throw breaking pitches, there are only nine players on the field, and so on. In softball, the pitcher delivers underhand (and in slow pitch, the ball must arc). The ball is much larger and does not travel as far, the bases are closer together and the pitcher's rubber (there is no mound) is much closer to the plate, and sometimes the players wear shorts which generally prevents them from sliding.
Those are just a few of the differences... but as you can see it determines the physicality of the sport. Why specifically/historically softball and baseball both developed in high school and collegiate leagues I do not know. | 9542b319-61db-4434-97d0-388ed088359c |
2a82pa | How are sex change operations done? | There are graphic videos on youtube if you're really brave.
Both male and female genitals start off as the same set of organs, as you grow in the womb, these organs are acted on by your genetics to become either the penis/testes or clitoris/ovaries etc. The structures being somewhat similar lets some be "recycled" during the operation.
Some people choose to have hormone replacement only and never an operation, everyone is different.
Male to female involves removing testes and the internal structures of the penis, turning the skin of the penis inside out to create the interior of the new vagina, with the tip of the penis being fashioned into a clitoris.
Female to male transitions are sometimes accomplished with hormone replacement only, which stops the menstrual cycle, and increases the size of the clitoris.
Surgery uses a flap of skin from the arm or elsewhere on the body to create a penis | 5526cabc-2f2a-4540-a725-e103de929cac |
4im85n | when the moon comes up, it's gravity is strong enough to rise the tide. How come small particles don't go flying as well? | Probably the biggest thing to understand is that the moon's gravity doesn't create the tides "all in one go". As the Earth rotates, the pull of the moon has a constant very small effect that over time builds up a sort of standing-wave front that we call the tides. It's the cumulative effect that causes the tides, not the 'instantaneous' gravitational pull. | 0f776773-a122-429e-8e78-2744dec551bb |
1l6xnb | why are Mozilla Firefox and Google Chrome so much better than Internet Explorer? What are the big problems with Explorer? If I have good anti virus software is there really a difference? | Historically you would be correct about IE being a bad browser. But it you use the Modern ones they are pretty equivalent to Chrome and Firefox. They all have add-on's to varying extents. They all confirm to standards pretty well. | 2df675a1-3613-4411-90ec-2843186be6fd |
k0z1z | why prosthetic limbs cost almost twice as much as a car | Supply and demand. Money doesn't really have any "real" value, all the prices you see are imaginary, so to speak. That's why diamonds, for instance, cost so much. It's not that they have some kind of actual value, it's just that people are willing to buy them at a certain price, and the seller, seeing as people buy them, obviously continues to sell them. Ideally, one wants to work/spend as less as possible and to gain as much as possible. This idea is widely practiced and it has lots of very unfortunate consequences around the world, but that's another issue altogether. | 10a2f49c-36a8-4c4f-8747-567d10f3e20c |
1jy50d | Why aren't there any HUGE bugs? | I believe that the reason for that is still under debate! though I could easily be wrong as I am basing this off of a discovery channel documentary I watched once, but there are 2 limiting factors that are likely culprits:
- the strength and mass of exoskeletons. at a certain upper bound they are no longer able to support their own weight. this bound exists in animals with internal skeletal structures as well, though I believe it is higher
- their respiratory system, which is less efficient. from what I remember a higher atmospheric oxygen level allowed bugs to be much larger in the past.
- whoa these bullets are square
- | bd1b57fd-7bb0-4f3e-a891-fafab1f29d3e |
1w33q2 | What is the point in hiding scores for comments for a certain amount of time? | People are most like to read only the first few comments...which are more likely to be upvoted...which are more likely to be upvoted...resulting in a kind of avalanche. People are also more likely to upvote comments that have already been upvoted.
Vote hiding attempts to counter this. | cc50a189-655a-42c5-92cf-9b6c542a14b6 |
388xxj | Why our voices sound so different than what we think they sound like | When something 'makes' a sound (a tree falling, or lightning striking), it does so by causing particles to bump into each other, then those particles bump into more particles, etc etc outward in all directions until they bounce off something.
When you speak, the thing making the sound is your vocal cords vibrating. Other people only hear the sound that is created as the wave passes through the particles in the air.
You, however, also hear the sound as it moves from your vocal chords through the solid/liquid mass inside your own head. | 8c43ddfd-0233-4546-b8b3-abc2b292f45a |
2qyohh | What happens if someone needs an ambulance during a snow storm and the roads aren't plowed? | ambulances are extremely heavy and so are great on driving on bad roads compared to regular cars, but at some point with a bad enough storm the answer is 'you wait and maybe die" | 612c85e6-17d8-4b5a-a35f-86d60787135f |
4wc4sn | Why can't you fight dementia by training your brain? | You can, to an extent - it has been shown that (for example) bilingual people and people who keep their brain active can fight off the *effects* of dementia for longer.
But a lot of types of dementia (like Alzheimer's disease) mean your brain is *physically* shrinking, and parts of it are lost forever. At some point too much of it is gone for you to be able to work around. | a705cade-707a-42c9-b0dc-d540fa7c7cec |
2bpvx5 | The myth that humans only use 10% of the brain. How is it incorrect? | When you point at something, you only use 10% of your fingers. Obviously, that doesn't mean only 1 of your fingers is functional, just that your other nine fingers aren't needed for that activity. Also, it doesn't mean using 100% of your fingers to point at something would make you "better" at pointing, you would just look like a weirdo trying to cast some kind of wizard spell. | 369034fb-c7d3-4f10-a5fb-bc6567dbefb4 |
2nok9e | What did the developers of HTML5 do to make things so much faster? | Nothing.
HTML is just a set of instructions telling a browser what it should display. There are different versions of HTML, the latest one being HTML5, but the differences between them are mostly a matter of a few new instructions (browsers are designed to ignore instructions they don't understand, so older browsers will still make an attempt to render an HTML5 page), and maybe some minor changes to the syntax.
How fast a page renders in a browser depends on how fast your computer is, how fast your internet connection is, how well-written your browser is, and what sort of content it's being asked to display (too many graphics will slow down a browser quite a lot).
If you're talking about HTML5 *video*... technically, there isn't actually such a thing, but for marketing reasons that's what it's been called. HTML5 has a new tag which instructs the browser to display a video. Previously, the only way to do this was to use a plugin, usually the Flash player; HTML5-conformant browsers now have a video player built-in, so they don't have to go through the whole business of firing up a plugin, a process that can take... well, a second or two, let's be honest: it was never a big deal. This video player can use a codec that can be easily compressed, meaning you have fairly high quality video with a smaller file size, so it's more likely to stream better.
That, at least, is the theory. | 76b03832-6b6a-4e54-a087-eec5b08387b6 |
pqdin | Tips Dividing | You need to explain your question better.
30% of $100 is $30. You got that right.
I'm not sure what's supposed to happen in your second equation. | 8b4b6f38-a018-48d0-beef-40790dc5d5a3 |
6ct5xd | Why is it so bad to drink ocean water, even for those who are on the verge of dying of thirst? | They say drinking seawater will drive you mad but it will dehydrate you & make you more thirsty because it contains salt. Also your kidneys can have a job processing that amount of salt. | 74fb616c-70b0-4c16-a16f-6be41b5f9255 |
2k9rkf | How are fake identities created? | I've known someone who was born in England and was sued through no fault of his own, then lost his council apartment as he couldn't afford the rent and then was made homeless... in England if you are booted out of council accommodation that's it you cannot get help again. Basically his life was in complete ruin and he couldn't see a way out.
He took out as many loans as he could, 3 phone contracts, as many payday loans as he could and cleared out what little he could out of his bank account and left it overdrawn. He then wrote a suicide note in his apartment for the bailiffs to find, left the country and flew to Poland, from there he traveled by hitchhiking and bus elsewhere in Europe, (Romania I believe). Scraped a small section of skin off of each finger (to slightly alter his finger prints) and then after a few years immigrated back to the UK with a new hairstyle, some minor plastic surgery and a different appearance in general. As far as I know he is now quite successful and leads a pretty good life. It wasn't easy immigrating back as far as I understand though but he did say he wouldn't have been too heartbroken if he had to stay in Romania as it was a better life than he had previously. | d61b097c-c9fd-439b-ab23-80bdbf62c719 |
1lb8o1 | Will human colonization of other planets ever be possible? | Look into Elon Musk. The Founder and CEO of SpaceX. He said in June that he has concrete plans to colonize Mars in 15 years. If anyone else on Earth said that I'd instantly write it off, but Elon Musk is seriously a super human. One of those people that literally comes about once a century.
He is known for having the genius of Nikola Tesla, the marketing chops of Thomas Edison, and the industrial intuition of Henry Ford.
He founded PayPal, which made him a billionaire when he sold it at 31 years old . However, he was already worth over $300 million after selling his first software start-up at 28 years old.
Its what he did next that will impact humanity for centuries to come. I'm fully convinced that our great, great, great, great grandkids will be forced to learn about Elon Musk in school just as we learn about Thomas Edison.
He founded SpaceX , and successfully took space flight from an absurdly expensive and novel government enterprise to a viable, profitable, and useful private enterprise. SpaceX developed the rocket that NASA now uses for payloads. Elon Musk's capsule docked at the International Space Station last year; the first ever commercial company to do so.
Besides creating an entire new industry by profitably accessing space and beyond he also founded Tesla Motors. In fact, he is founder and current CEO of Tesla Motors, SpaceX, AND SolarCity (the largest residential solar installer in the U.S.).
[Here's a superb article on this super human](_URL_1_)
He's been in the news recently because he is Founder and CEO of Tesla Motors. With zero industry experience he entered the auto industry, which is also a particularly well insulated industry [(recent and related article)](_URL_0_). He was considered naive by industry insider's, and you can't blame them. Building and marketing a traditional vehicle, much less a revolutionary electric vehicle, is a skill that would take most people a lifetime to master. So how's he handling it?
Tesla Motors stock is up over 450% in the last year. The latest Model S received the best safety rating of ANY CAR EVER, and won the coveted "Motor Trend Car of the Year Award" in 2013.
This has all genuinely shocked the industry. Imagine the logistics and knowledge it takes to RUN an auto company, much less INVENT one from scratch. Then, realize that he is currently CEO of not just Tesla Motors, but also the CEO of SolarCity, and a space rocket company. Oh, and he has 5 kids.
If Elon Musk says he has concrete plans to colonize Mars within 20 years. I genuinely believe it. There's 7.1 billion people that could say the same statement, and I'd laugh, but Elon Musk is truly something different.
The more you find out about him the more you think he can't be human. At first I figured "OK He founded a few companies. He's a good business man. Plenty of those to go around".
But when you look deeper this dude didn't just found PayPal - he MADE PayPal. He doesn't just invest his way into companies he MAKES companies.
Specifically, his goal is to guide humanity to a new age. Solar panels, electric cars, space exploration, colonizing freaking Mars. Only now does it hit me he IS human, he's just from the future. I would gladly give this guy a trillion dollars just to see what would become of it. | 8d081df0-84b7-4496-91b1-51427fdf11b9 |
1vikdf | what is physically different from a "normal" brain and a psychopath's? | The term 'psychopath' refers to a large array of behaviors, which do not necessarily correlate to brain differences. Some people may behave differently based on their upbringing and experiences, for example. However, some brains do function differently than most human brains, and we know a small bit about this.
To start, human brains are composed of a large number of parts which work together (and against each other, at times) to form our consciousness. Some parts of the brain perform different functions, like vision, memory archiving, and abstract processing.
The amygdala is the fear center of the brain; trauma or injury here can make people more or less afraid of things. Sometimes, the amygdala can be intact but not functioning. We don't know why this is, and this is the case for a lot of mental disorders.
People with schizophrenia and Alzheimer's often have brain-wide tissue shrinkage, so there can be large differences in actual brain structure. However, to answer the question, *sometimes there are large brain differences in people with mental disorders, and sometimes there aren't.*
[Here is an MIT lecture on brain disorders.](_URL_0_) | 4d70ec5b-c218-4942-87ac-c477776cec34 |
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