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kxem5e
|
We all have seen what dust does to air filters, how are our lungs kept clean?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gj9scis",
"gj9svha"
],
"text": [
"Mucus lines the inside of our lungs. When dirt and bacteria enter, the mucus surrounds it and breaks it down. When there is too much bacteria and crud your body produces too much mucus and that's bronchitis, or when you cough up chunky globs of mucus. That's our organic \"air filter\"",
"In your lungs, the walls of the air passageways (called \"bronchial tubes\") are lined with tiny little microscopic cells that have little hair like features, called \"cilia\" that wave back and forth, along with other cells that create mucus. The particles get trapped in the mucus, then the cilia move the mucus along the tubes out to your throat, where you either swallow it or spit it out. That mucus then also holds the dust, pollen, dead skin, hair, everything that you breath in with your air."
],
"score": [
8,
7
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"text_urls": [
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|
[
"url"
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[
"url"
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|
kxenz3
|
Why do the clocks on an Apple iPhone and a HP laptop have a 1 minute time difference, if both are set automatically?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gj9xj0e",
"gjbr8ov"
],
"text": [
"Both devices are set from different time sources that may have different lag times. The iPhone is set either from the cellular network or from GPS, while the laptop is set from an internet-based Network Time Server (typically URL_0 ). Internet time sources tend to be slightly off, because they are a couple of \"hops\" removed from the true time source (and because of inconsistent Internet connections), while GPS and your cellular provider connect to the time source directly. That said, a 1-minute difference is a little much. They should be a few seconds off at most.",
"Most likely the HP laptop is wrong. Common causes: * If it's older, maybe its CMOS battery is dead * The Windows Time isn't configured correctly * The Windows Time background service doesn't start properly * Something (firewall) is blocking the NTP updates (UDP port 123)"
],
"score": [
5,
3
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"text_urls": [
[
"time.windows.com"
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|
[
"url"
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[
"url"
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|
kxeojy
|
Why have people created different programming languages and keep creating new ones?
|
So wouldn't it be easier if instead of creating thousands of programming languages, people created one - super cool, advanced, universal etc? Why can't they all be combined into one?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
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"gj9u36v"
],
"text": [
"Because one day, someone will discover that your one, super cool, advanced, universal programming language either can't do one specific thing, or can't do something fast enough for what they're doing. So they'll create another programming language. Then it'll happen with someone else, and they'll create another programming language. Repeat, repeat, repeat, and we're right back where we started. [Also related.]( URL_0 )",
"To give you an analogy, it is like why there are different kinds of motorized vehicles. We don't want a super duper do it all vehicle because it would be expensive to make, to operate and have too many compromises. Sure a tractor can \"in theory\" drive a family from city to city but it would be much more practical to drive a sedan, for example. If you tried to make a vehicle that was economical, carry lots of passengers, lots of goods, went really fast etc etc, it would end up being a monstrosity. It is very similar to programming languages. A sufficiently developed general purpose language like C+ or similar could be used, \"in theory\", to code any programming task needed. It would just be overkill, amazingly unproductive and complicated to do so. So there are specialized languages that are \"better\" at handling specific needs - like web pages or mathematics or statistics or database management or AI programming. In truth, the difficulty of programming isn't the language - anyone with experience will pick up a new language fairly quickly. The coding is the \"easy\" part. It is understanding software architecture, optimization, robustness, user interface, etc etc that are far more difficult to learn."
],
"score": [
9,
6
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"text_urls": [
[
"https://xkcd.com/927/"
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|
[
"url"
] |
[
"url"
] |
kxeuwe
|
Why haven't we run out of phone numbers yet?
|
Are they recycled? If we do, what will happen?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gj9to50",
"gj9t7le"
],
"text": [
"There are a lot of number permutations. A North American number has a 10 digits, which means that there are exactly one billion possibilities. Furthermore, countries also have their own codes. In the USA and Canada, we use 1, Germany uses 49, Panama uses 507, etc. So, that means a full phone number could have up to 13 digits, meaning that there could be up to 1 trillion possibilities. One trillion numbers for 7.8 billion people should be enough. Yes, numbers that are discontinued can be recycled.",
"There is some recycling. I get calls for the guy who had my number before me. Mostly from businesses, but also some friends I guess he never updated."
],
"score": [
10,
7
],
"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
kxev8i
|
Why do feet get cold so fast but warm up so slowly?
|
Yes, my feet are cold right now. My hands were even colder than my feet but they warmed up pretty fast and I didn’t even keep them under my blanket (like I did to my feet). I hate when this happens and I was just wondering why.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gj9v9m9"
],
"text": [
"Sounds like blood flow. The feet are furthest from the heart and require more effort to get blood circulating. Both the hands and feet can have poor circulation."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxfa6x
|
Why do hairs on certain areas of your body stop growing once they reach a certain length but others don’t?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gj9y9qi"
],
"text": [
"It's not that they stop growing at a certain length. Hair is always growing. It's just that they wear out until the end breaks off. Some hair grow faster than others, and some are more resilient to breaking than others. So the average length they reach before time wears off the tips varies for each hair."
],
"score": [
8
],
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[
"url"
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[
"url"
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|
kxfxxy
|
how big fish can swallow other fish whole. Why can't smaller fish swim out? Can't they attack the big fish from the inside?
|
Thanks! Edit: to all the comments saying it would suffocate and be trapped in the stomach. I get that. But when I picture the stomach I don't see it as armored or anything. It's still very soft flesh. I would assume the smaller fish would at least have a couple moments to struggle and bite before it suffocated. Even if a large fish/shark/whale was bitten from inside their stomach once or twice I W OK ukd think that would still cause issues.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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"gjadirv",
"gjavpjx",
"gjbiku8",
"gjc1wd5"
],
"text": [
"Assuming it doesn’t get killed when chomped on and survives to get swallowed whole - once in the stomach the eaten fish is confined in a tough bag that holds them in place in an environment with no access to oxygenated water. It’ll soon suffocate and die. With no water there’s nothing to swim against, and the predators stomach is tough enough to resist damage by their prey. They’ll mostly avoid eating fish that’ll give them problems.",
"They quickly suffocate as there isn’t sufficient water flowing over their gills anymore. Also there is no empty space to really move around, it’s like being wrapped up in a blanket as all the tissues are pushed up against you and unable to do anything but wiggle a little bit until you pass out",
"Regarding your edit: The fish being swallowed eats the same way the big fish eats... it swallows stuff. So, it's not really a biter/chewers either. And I think the time between getting swallowed and being immobile is almost instant... there's no time to do anything.",
"Stomachs are tougher than you're giving them credit for. They're not bone-armored, but they're quite resilient. The kinds of fish most likely to swallow things whole tend to have stronger stomachs. Also, digestive acids are quite powerful - for some species, that alone would rapidly incapacitate swallowed prey.",
"There is a pic around here somewhere depicting an eel burrowing out of a flying egrets neck... -successfully- he was having none of it. Hope he at least landed in water."
],
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[
"url"
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[
"url"
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kxg1ns
|
Coffee and cocoa beans are awful raw, and both require significant processing to provide their eventual awesomeness. How did this get cultivated?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gja40dj"
],
"text": [
"We actually don't know about coffee. While there are \"stories\" about it, really, we don't know, the first actual evidence we have of coffee is not until the 1400s on the Arabia peninsula (but it certainly could have, and likely did exist long before this) But the processing of a seed into a beverage wouldn't be that unusual, although it may seem so by modern food standards. Various \"teas\" were commonly made from plants, herbs, seeds, nuts, roots, and such for most of history (these same things would have been used to flavor tons of beverages, from teas, wines, beers, whatever). Coffee beans originated in either Yemen or Ethiopia, so someone deciding to cook the beans and grind it to make tea isn't strange when you have potentially 2000 years to figure it out--You have plenty of time to experiment with ways to make it taste good, and cooking, steeping, crushing, and all that with various local plants would have been normal across the world, although lets be very clear-- the first real evidence we have of coffee is not until the 1400s, so it may have been made before, but we don't know of it until then, so maybe it was new or not, we don't know and probably never will."
],
"score": [
7
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[
"url"
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[
"url"
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|
kxg2ka
|
How does blood circulate through your body after you've had an amputation?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gja21t1",
"gjb3uic"
],
"text": [
"Your circulatory system is not just one singular loop, it branches and splits, then comes back together again later. There are numerous routes blood could take to get to your finger, for example; but they won't have come from your leg. URL_0 Blood takes a fairly straight path from your heart and lungs to your extremities, and back again.",
"You can kind of think of arteries carrying blood from the heart, and veins carrying blood back, as the two legs or sides of a ladder, with smaller arteries and veins, that branch off and connect via capillaries as kind of like the rungs. So blood flows up one side of the ladder, but at every rung, some blood crosses over to the other side, and starts to flow back. If you cut off the top part of the ladder so that several rungs are gone, the blood can still cross over at all the lower rungs. Also large vessels have some ability to narrow themselves and reduce flow, if they don't need to carry as much blood, and the smallest vessels can actually remodel and reroute themselves after a major disruption like an amputation or a bone graft or whatever, to make sure all areas of body tissue get the right amount of blood delivered."
],
"score": [
13,
3
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"https://images.app.goo.gl/dgYi1GJ3Pc7L1jew5"
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[
"url"
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[
"url"
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|
kxg9dd
|
How come when fire ants make their living raft from each other, the ants on the bottom don’t drown? Saw on BBC recently.
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gja2v0u",
"gja23nw"
],
"text": [
"For things our size water is like water. For things the size of an ant water is more like Jell-O so many insects can basically walk over it. Also, the exoskeleton of many bugs is hydrophobic, which helps them to repel water.",
"They are so small and light that they don't break the surface tension of the water. The bottom ants aren't underwater."
],
"score": [
7,
5
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[
"url"
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[
"url"
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|
kxgeq1
|
How does meditation improve the things it says it does, such as memory, concentration, sleep, or blood flow?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjaryj9"
],
"text": [
"Like any skills, passive or not, practicing them is training them. Memory: when meditating you are practicing having calm recollections of your day/life. Stopping and giving yourself time to remember things allows you to train your memory recollection skills. Concentrate: when meditating you are practicing the art of letting thoughts pass instead of dwelling on them. Then you can apply this to non meditating situations where you want to focus on something, you’ll let other thoughts pass by. Sleep: when meditating you are practicing the art of being calm and letting thoughts pass instead of dwelling on them. Being calm and not dwelling on that time you did that embarrassing thing at 13 in front of your crush helps you sleep. Blood flow: all of the above is a great stress reliever."
],
"score": [
8
],
"text_urls": [
[]
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|
[
"url"
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[
"url"
] |
|
kxgfsh
|
What is a Tesseract?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gja5by0"
],
"text": [
"If you start off with a singe point it does not have any dimension, no width, no height and no depth. But you can extrude this point in one dimension and get a line which is a one dimensional object. If you then continue to extrude it in a different dimension you get a square which is a two dimensional object. And with the next extrusion you get a cube, a three dimensional object. In our universe with the three spacial dimensions you can not go any further and you are stuck with the cube. But if you had a forth spacial dimension that you could extrude the cube in you would end up with a tesseract. This is a four dimensional object, which means it can not actually exist. However we can still use it in mathematics which deals with such abstract concepts."
],
"score": [
13
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[
"url"
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[
"url"
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|
kxhhxa
|
When two countries are at war, how can the Heads of State "hide in plain sight" without being air raided? Why the germans didn't drop bombs on the Royal Palaces in the UK or vice-versa?
|
I mean, why didn't the allies just dropped bombs on all of Hitler's houses and killed him? Or just drop bombs on all military camps while the troops were at sleep or something like that? Or the atomic bombs, why Hiroshima and Nagasaki? Why not the Emperor's Palace or the army bases?
|
Other
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"One of the things about bombing in World War 2 was that it was very inaccurate. There are various reasons for this, but the result was that even hitting the right *city* wasn't always guaranteed - especially for night raids, which were safer but less accurate. So targeting a particular individual, even if you know where they are at a particular time, is difficult. On top of that, you can guarantee that anyone important will have a good bomb shelter. When it comes down to it, long range bombing simply wasn't that effective until late in WW2. Similar things apply to military targets. With the added complication that if a military knows it's at risk of bombing it will move around, disperse forces, use camouflage, strengthen defences, and take various other measures to limit the effectiveness. A good example of a campaign against military targets is the Battle of Britain, when the German air force tried, and failed, to defeat the RAF by attacking airfields and other targets. Now as for the atomic bombs, the choice of Hiroshima and Nagasaki is an interesting topic. One small point is that the attack on Hiroshima was partly justified by the idea that there were multiple targets in the city, so attacking it *was* attacking army bases, naval bases, munitions factories, etc.. Why not try and kill the Emperor? Well not only do the problems listed above still apply, but also if you want peace you need someone to negotiate with - or at the very least to sign a surrender document. Kill off the top levels of government and who will take over? Will they be more or less inclined to carry on the war? Will they have the political authority to make peace even if they want to?",
"> why Hiroshima and Nagasaki? Because the US had already firebombed almost two dozens cities and those were some of the only ones left. Those two specifically got bombed for the simple reason that it was a relatively clear day there so the bombers could aim; if it had been cloudy the planes would have flown to other cities. > Why not the Emperor's Palace I don't want to say he was *innocent*, but the emperor was not the leading political power and by the time the first two bombs were actually ready, Japan had already been effectively militarily defeated. Some members of the war council had already made back-channel overtures (which were ignored), and it was really just a matter of waiting for the hard-liners to recognize defeat (which they finally did when the Soviet Union swept through Manchuria with shocking speed). American strategy was already turning to what happened after surrender. Killing the emperor and destroying the palaces would have no military value and would only anger the civilian population.",
"First, the Germans [did drop several bombs on Buckingham Palace]( URL_0 ). But such places always have had bunkers built so that when bombing raids began, the heads of state could quickly get to shelter. The same with Hitler and so on; there's a reason his final days were in a deep bunker. It takes time for a bomber to get to a target, and there is usually warning of some sort, especially with radar. (Missiles complicate this, but German missiles were not nearly accurate enough to target any individual, specific building.) Second, states generally tend not to try to assassinate the heads of their enemy's state. Why? First, because what goes around comes around, and that makes for bad business if you're a head of state — better to let your troops fight it out, than to put your own neck on the line. Second, the death of a head of state _by itself_ does not necessarily lead to the collapse of an enemy's will to fight. Take FDR for example — he died (of natural causes) in the middle of World War II, and the US war machine didn't even hiccup. Hitler dying was a fitting end to the Nazi regime, but it was already essentially dead when he took his own life — Hitler's death isn't what ended their ability to wage war, their losses led to Hitler's death. If you think the death of Hitler, or the Royal family in the UK, or even Roosevelt or Hirohito or Stalin, would have caused any of those states to _stop_ their war... you're probably wrong, unless they already had lost said war completely and obviously. The specific reason the atomic bombing targets were chosen is complicated, but the reasons for not targeting Tokyo with the first ones were 1) Tokyo was already heavily damaged from firebombing, and they felt that it would not showcase the power of the bombs if you set them off in an already-destroyed city; 2) the US understanding of the Japanese power structure was that it was based around a small Supreme War Council in Tokyo, with the Emperor as a titular head of state who in reality did not do too much. Their hope was to get a surrender, and you need someone to surrender to you. The best bet for that would be said War Council and said Emperor. Killing them would result in rolling the dice and not knowing what would happen next; one could not assume that the next Japanese cabinet would be more willing to surrender. The _long term_ plan was to occupy Japan and turn it into an ally — something that would be made _much_ easier if the Emperor survived and cooperated. Lastly, it is worth noting that while it is not clear where the target of the _third_ planned atomic bomb would be, there are some indications that it might have ended up being Tokyo. So in that particular case we may be looking at a quirk of timing and planning rather than something that could have been only one way.",
"1. Hitler being alive benefited the allies immensely. He was a literally methed up squirrel who kept senselessly fucking with the plans the actually competent generals made, hastening their defeat. 2. Most heads of state are far from irreplaceable. Except for dictators, the actual military operations are out of their hands, so at most it would be somewhat demoralizing - or the opposite a la London Blitz. 3. They have bunkers my dude.",
"Flak guns and various anti air artillery have meant that to get that far or be in their air space that long would mean that you would die. Most countries during war time will heavily fortify and arm areas around their capitals to the point of absurdity."
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[
"url"
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[
"url"
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kxhnbz
|
How people are able to know the location of all keys on a keyboard without looking but if you were to ask them where a specific one is they wouldn’t know.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjaa9ny",
"gjae2y9"
],
"text": [
"Muscle memory. It's like walking. Your body knows how to walk, but if i ask you how it works, you'd probably have a hard time trying to explain how you know you know how to walk. Edit: I should probably put more explanation into the typing thing. Okay so, with typing, you know how at first you start slow? Maybe go with 1 finger for each hand to go for the letters? Then you start to have a feel where the letters are and so naturally, you get faster with the one finger method until you start going to two fingers, three, and so forth. You'd have an idea where the letters are, like Q is on the top left area of the keyboard, and so your hand would instinctively hover near to that letter in fingers reach. At some point, everything in your mind would just seems like one motion, less steps to take to do something. But when asked to stop, slow down, and go through each steps that you were training yourself to do, it would take some time to consciously remember.",
"There's no magic. Lots is practice, often watching what you're doing at first, until you just know where to two or swipe. Practice like repeating words or phrases, transcribing longer texts, and eventually writing your own words. As you practice, your hands get used to moving and pushing in the right way to result in the right character. Even after years of doing it, sometimes you peek, and you'll still make mistakes. But the more you do it, the fewer mistakes, and the faster you are between."
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3
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[
"url"
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[
"url"
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|
kxi90b
|
How does freezing water manage to crack metal pipes?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjae26p"
],
"text": [
"As water freezes, it expands. So when a pipe full of water freezes, the ice expands against the pipe’s walls which causes it to break."
],
"score": [
17
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[
"url"
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[
"url"
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|
kxinyc
|
Why Are Rainbows Curved?
|
My mom, who is a Q-Anon conspiracy nut asked me to explain why rainbows were curved, which I couldn't answer. Her answer was because we live in a dome and the earth is flat (mega eye roll). So, can anyone explain, like I'm 5,why rainbows are curved so I can actually answer this?
|
Physics
|
explainlikeimfive
|
{
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"gjah5c6",
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"text": [
"[Explanation is a bit complicated]( URL_0 ) Also the spray from a hose causing a rainbow has zero bearing on the curvature of the earth. Also there are circular rainbows, checkmate flat earthers!",
"It is not because water droplets are round, except because that causes them to refract light. Think of a prism that refracts a beam of light into a rainbow. This happens at an angle, and with a water droplet that angle is about 40 degrees. Each color comes out at a slightly different angle which is why you see them spread out across the surface it projects onto. Imagine you have a length of stiff wire that you bend at 40 degrees to simulate the path of light coming from the sun, bending at a tiny droplet, and then coming to your eye. One end points at the sun and the other at your eye; how many ways can this be oriented so that works? As you can see there are many ways that form a ring with the sun in the center. Because light from the sun is being bent by the water drops you see it coming from a different direction than the sun, but always at a specific angle away from it. On the surface of Earth the path of light can be blocked by the ground so the circle seems like an arch.",
"If you are lucky in an aeroplane or a helicopter (something with big-ish windows) you can actually see a fully round rainbow! That is how the sneaky Irish Leprechauns managed to defeat the modern age when you could chase a rainbow with an aircraft to the end to recover the gold.... Sigh..... :-)",
"Rainbows are created by sunlight passing through water droplets, which are round. The rainbow would actually be a circle if the ground weren't in the way.",
"It's a complete ring. Or would be if you went high enough. Draw a line from the sun to a point in the red line of the rainbow, and a line from your eye to the same point, and you get an angle. Every point that forms the same angle will be in the red line. These points all lie on a circle because of geometry.",
"Not a scientist, but the thing i always heard was this: light is a wave (and a particle, but that's irrelevent here). As such, light has a frequency. Different colors of light have different frequencies. Red light has the lowest frequency, and violet has the highest. These different frequencies cause the light to get reflected and refracted out at SLIGHTLY different angles when split by the rain drops based on their color. As other people have said, a rainbow is actually a ring around a raindrop (or drops) and so the rainbow is centered on those drops. Quick google search says that the rainbow is 40-42° offset from the line between you and the center of the ring (40 being violet, 42 being red) Self fact check (source): [ URL_0 ](https:// URL_0 /earth/what-gives-rainbows-their-curved-shape)"
],
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3,
3
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[],
[],
[],
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[
"url"
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[
"url"
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kxj9ay
|
How come when you blink sometimes it makes a sound?
|
It doesn't do it much, usually at night. But when I blink, it makes a 'squish' sound. Am I the only one?!
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjalbg3"
],
"text": [
"You’re not the only one. Maybe there’s some pocket of space that allows that to happen, just like doing armpit farts."
],
"score": [
3
],
"text_urls": [
[]
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|
[
"url"
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[
"url"
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kxjc5e
|
Which would be more efficient and why? Going up the stairs a step at a time or skipping a step?
|
One at a time would use less force per step but more steps are required meanwhile skipping a step would require more force but less steps.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjaru3r"
],
"text": [
"From a physics standpoint, the amount of work done would be identical between the two. However, it is possible that muscles use energy more or less efficiently depending on how hard they're working. In which case one may be slightly more efficient in terms of energy expenditure than the other. However, I study physics not biology, so I can't be too sure if that would be the case for the muscles."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxjgi1
|
When a liquid freezes it’s molecules get packed together to form a solid, but water expands when it freezes?!
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjam845",
"gjaprgz",
"gjariap",
"gjatku6"
],
"text": [
"Yeah, water crystalizes. The water crystal arrangement take up more volume than water in liquid form.",
"It all depends on what is happening to the atoms or molecules in the material when it freezes. For some materials, when they are liquid the atoms and molecules move and slide around each other randomly, and when they freeze they more or less stay in the same configuration they were at when they froze. Glass is a perfect example of this, glass is just a random assortment of molecules that when really hot, flow around each other randomly as a liquid. However when it cools down and freezes the molecules just get locked in whatever position they were in when it froze. Some materials behave differently however. Water is one of those, when its a liquid it's molecules move and slide around each other and can pack pretty tightly and randomly. However, when the water freezes the molecules don't want to stay in random places, they like to link up and form structures called crystals. These crystal structures aren't packed as tightly as the liquid water sliding together, so the ice expands and becomes less dense. Why some materials behave one way and others behave another is a different and very deep topic.",
"Water is a molecular oddity in this regard. Your normal ice does indeed take up more volume than the water it formed from. Most other materials are not like this. Basically, as water freezes, it prefers to be in a less-dense configuration because of its unique properties. As an example, you know how oranges and other round fruits are stacked in grocery stores? That’s the densest packing possible for a stack of spheres. But buckyballs, those small spherical magnets, will stack in a cube shape because their strong magnetic interactions push them out of the densest stacking. Water does similar on a molecular level.",
"Packed together isn't necessarily the right way to think about it. While it's true the lower temperature causes the molecules to become slower and more condensed, they don't become a random packed together pile, like pouring Legos out on the floor. When they get cold, they slow down enough to start bonding in a lattice like pattern to create the solid you know as ice. You may think of this like taking the Legos and piecing them together in an exact repeating pattern. You'll notice by the time your done connecting the Legos in the repeating pattern, the structure you've made takes up more space than when it was just a random pile on the floor. Similar to the water, when the molecules slow down enough to freeze, they begin to connect in a pattern specific to their molecular structure (different molecules = different patterns), causing the connected molecules to take up more space in their solid form."
],
"score": [
4,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxji6k
|
Why is it profitable for companies to ship jobs overseas? Question expanded in text
|
I understand that companies save a ton of labor costs by sending jobs to another country. But, what about the cost of shipping their products back to the U.S to be sold? Doesn't the cost of shipping cut into what they saved on labor?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjalxff",
"gjam6d4",
"gjamczo"
],
"text": [
"No. Industrial-scale shipping is *very* cheap, to the point that some things are shipped from country A to country B to be processed and then shipped *back* to country A.",
"Container shipping is incredibly efficient. To the point that it really doesn’t matter - a whole container load is about $1500 from China to the US; weight is more or less irrelevant (it’s the volume that counts) so you can ship a million dollar worth of goods inside one, and fractions of a cent to each individual unit.",
"Not significantly. Even paying import taxes are still not enough to make it less expensive. Consider this. I make widgets. Each widget take 4 hours to fully assemble. In the US I have to pay an employee $20 per hour to make that widget, so a total of $80 bucks. Market demands I can only charge $100 per widget, to be competitive, so I'm only making $20 per widget profit. Now, I go to china. In China I can hire 20 people at $1 an hour to do the same thing. Then maybe it costs me another $20 to ship a box of 20 widgets that just cost me the same as it would have cost me to make 1 in the US. So I sell those 20 widgets for $100 each. The total cost was $20 plus $20 shipping and maybe another $20 in import taxes. My profit went up from $20 total, to $1960 total. Which is a better profit?"
],
"score": [
12,
6,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxjljo
|
How do whales breath then they’re sleeping if they’re always underwater?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjanbth",
"gjana26",
"gjaogce"
],
"text": [
"Because, they're not always under water. Also they only sleep with half their brain, the other half takes care of swimming, surfacing to breath, etc.",
"Answer: Whales never fully go to sleep like we do. They shut down one half of their brain and continue to swim to the surface to breathe.",
"As stated above. The brain sleeps in halves. In a 24 hours day each half gets 8 hours of rest, the last 8 hours is when the brain is functioning fully. During the time the brain is resting, the whales will still do everything you would normally except them to do, they are a lot slower and less energetic. During the 8 hour period that both halves are functioning, they will be most active and social."
],
"score": [
41,
41,
23
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxjmtf
|
Why does 24fps Film look so smooth but 24fps Gaming look so bad?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjamxie",
"gjb06fb"
],
"text": [
"Motion blur. The film captures motion as blur, and the eye interprets blur as motion. Motion blur transformation is extremely computationally expensive. Movie special effects might be able to afford it, but your gaming rig can't. Games stutter motion, and the eye sees stutter as an error.",
"A few reasons: * Filming naturally blur between two frames. If something is moving within the shutter time of a single frame, it's picked up in multiple places on that same frame. Games can fake this, and games on console that run at 30 FPS use this heavily to avoid looking nauseating. They just don't look as good as natural and accurate blur. * Movies and shows tend not to use rapid camera rotations, as they look bad. A lot of 3D games use this constantly, every time you turn your view. Limiting the worst looking scenes for low FPS is easy for a movie, not for a game. * You don't play a movie, you play a game. You can feel a game being unresponsive, delayed, and choppy. It's not just what you see, it's what you feel between your hand inputs and what happens on screen due to them. You don't see this in a movie. Even spectating a game you don't notice frame rate anywhere near to the same level you do playing. It's a feeling as much or more so that something you're seeing. It's sort of like watching a car drive. You can feel the difference in handling between cars pretty easily as the driver, but not by simply watching or riding in a car unless you really know what you're looking for. * You're just used to movies and shows looking bad. Higher FPS still looks better. And things with a lot of random motion rather than highly coordinated cinematography, benefit from it quite a bit, like sports. Some movies have even tried higher, and people complained because they actually like it looking worse. People sometimes like sticking with shit more than they like change. The fact that the hobbit movies were trash for other reasons also probably didn't help the cause, had the Lord of the rings trilogy been 48 FPS it would be a different precedent, we'd probably be watching all movies in 48 FPS right now."
],
"score": [
23,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxjy7a
|
How are animals trained to detect anxiety attacks (among other emotional or mental illnesses)?
|
Perhaps *sense* would have been a better word. But in general, how can animals *tell* and follow human behavior?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjasy0m",
"gjbpkmb"
],
"text": [
"They are trained to identify early behavioural cues if I'm not mistaken. But a lot more important is the smell. Usually mental health conditions affect in one way or another your hormones, such as anxiety attacks and panic/fear sweat to name one example",
"My wife has PTSD and uses such a dog. Her service animal is trained to respond to any variety of multiple factors: certain behavioral cues, a specific vocal command to initiate soothing/protecting, and most uniquely, she is trained to smell hormone changes like a rise in cortisol (which spikes during anxiety attacks/ptsd episodes)."
],
"score": [
11,
10
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxk2aa
|
how Germany de-radicalised (and understood the error of their ways) after Nazi rule before / during WW2?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjatw48"
],
"text": [
"It was basically a mixture of many factors, but the allied forces had a large influence. The bombings by the allied forces, destroyed homes and lives, death, hunger and cold had a MASSIVE influence on people’s morale. Men returning home after the war - IF they returned, after all - had learned the hard way that war is a bad idea. Many of them just wanted to live a *peaceful* life afterwards. People living near the Buchenwald concentration camp were led through the concentration camp by American soldiers after it was freed; they had to see the mountains of murdered people, had to face what they had ignored for years. I can only assume that this happened at other places near concentration camps, too. In the Sowjet zone there was the „Entnazifizierung“ (de-nazification) - with harsh methods. The part of Germany which used to be Prussia was taken from Germany, Germans who lived there were forced out. They fled to what’s left of Germany, many of them not surviving, especially those who were forced out in the middle of winter and fled across the frozen Baltic sea. The survivors were put into random families‘ houses who had to share the things they had with the refugees. The Nuremberg trial happened, where many high-ups ended up dangling on a rope. But it has to be said that a few simply pretended to be „good“... Some of them even became influential again and hid the fact who they used to be. Some changed their identity. Maybe sometimes people knew but turned a blind eye on this? When the Bundeswehr and NVA were founded, some Ex-Nazi officers were (for the lack of a better word) „whitewashed“ to train the new recruits. After all, there wasn‘t much choice among military trained Germans. It’s a very difficult topic, and even today, Germany struggles with this horrible past and tries its best to never let it happen again."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxk81k
|
How does freezer burn ruin food?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjaqyog",
"gjar7kj",
"gjb9x6u"
],
"text": [
"It pulls all the water out. The food is essentially dehydrated, but with the addition of enormous ice crystal damage so it doesn't rehydrate nicely.",
"Freezer burn happens in auto defrost freezers. The freezer cycles warm to melt frost build up. This unfreezes the outside of your food. Then the food refreezes. This thawing and refreezing cycle ruins the food.",
"When water in organic cells freezes, it can burst the cell membrane. This is particularly true with actual ice formation on the tissue. It's like frostbite, but on your food. Another way to think of is that, due to tissue damage from freezing, the food breaks down a bit. Your pork chop's been \"cooked\", in that it's breaking down proteins and bonds, just very terribly."
],
"score": [
13,
5,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxkeb8
|
How the heck did car cassette adapters work
|
Every time I use the cassette adapter to play music off my iPhone in my car (I drive an old beater) I'm just like...what is this marvel of human engineering and why is it only 10 bucks at Walmart??
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjaru5k"
],
"text": [
"The basic idea of a magnetic tape cassette is that a moving (changing) magnetic field will induce an electric current in a nearby conductor, and that signal is then amplified to the speakers. A changing magnetic field can also be generated from current passing through a wire. Put such a wire very close to the read head of the cassette player, and then play back an audio signal through it, and there you have a cassette adapter."
],
"score": [
13
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxkl6t
|
Why is it that bathroom condensation forms when a hot shower head is running, but not a hot bathtub faucet?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjaszvx"
],
"text": [
"The shower head sprays the water out in a way that exposes much more surface area, allowing the hot water to evaporate much faster. The faucet's flow is mostly not spray and it therefore exposes much less surface area."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxkss1
|
How are natural flavors extracted from foods, and how are artificial flavors made to match real flavors?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjb30q0",
"gjb4lgx",
"gjb73it"
],
"text": [
"I learned from a nutritionist that a \"natural flavor\" is made artificially it just means it is a flavor of a natural substance. Whereas something like redbull or monster are flavors designed to taste good even though they aren't based on a natural flavor so they are considered \"artificial flavors.\" Either way, made in a lab.",
"Vanillin is a chemical found in natural vanilla. It is a huge component of vanilla flavor but vanilla has hundreds of contributors to its flavor. Vanillin is easy and cheap to synthesize. A lot of artificial flavors are a flavor component synthesized or abstracted and added to a food. Flavors are extracted from food by solvents, steam distillation, dehydration, and many other techniques.",
"The PROOF podcast has a double-episode that explains this via the Beanboozled Jelly Belly beans. To summarize, first scientists take, say, some lemon zest and put it through a complicated machine that tells them all of the chemicals inside the lemon zest and how much of each. Then the scientists recreate those volatile chemicals that give us the lemon scent (and taste). (Acid does make lemon sour, but what makes lemon taste different from lime are this volatile chemicals that our nose absorbs and then our brain interprets as lemon. The volatile chemicals both make the smell and certain taste of an item) The recreation takes a bit more guess work than it sounds because even when they perfectly recreate the formulas, they don't taste exactly the same (and they aren't sure why). Still, it gives a baseline, and the scientists can go from there. They might subtract or add another chemical to recreate that exact flavor. It's akin to how a painter might look at a paint and say \"this needs a bit of red to make the proper color\" or \"this has too much blue to be quite right\". It's a highly specialized skill that does not have hard rules, but takes a special eye (or nose in this case). As to how they specifically manufacture these volatile chemicals, I'm not sure. I believe in the episode the host mentioned that relatively small companies specialize in only a few chemicals and they keep their manufacturing secrets close to their chest. So Joe Bob's might make only five chemicals, but if you want those five chemicals, you gotta go to Joe Bob's. An artificial taste is usually five or more chemicals put together."
],
"score": [
6,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxlakr
|
why is the inside of our mouth less sensitive to heat than our skin?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjay2t9"
],
"text": [
"It’s the other way around for me. If I eat something like, for example, a hot pocket, it doesn’t feel too hot in my hand when I pick it up, but then when it’s in my mouth it’s like I’m eating the sun.."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxlhjr
|
Why do some LEDs still glow after turning them off?
|
I got some multicolor LED strips in my room and when I use the remote to shut them off for the night, a few of them still glow. Why does this happen?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjaz790"
],
"text": [
"The ELI5 explanation is: bad design. There is enough leaked current from whatever the are using to control the current (triac/transistor/SCR) that feeds the LEDs. There are ways to fix it"
],
"score": [
13
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxlnte
|
How do surgeons not have their patients bleed during operation even though I bleed fountains from a paper cut?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjb08fc",
"gjb67q2"
],
"text": [
"Cauterize the wound with electricity, basically burn it closed, and also use clamps on the blood vessels.",
"They clamp veins and arteries, especially during transplant surgery. Source, i am a transplant surgeon. First person to call my lying ass out get 1 million points, redeemable only in sexual favors and they have NO cash value."
],
"score": [
17,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxlvr5
|
What is it, exactly, that makes a baby of almost any species so identifiable as a baby?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjb4mwb",
"gjb4781",
"gjb4qyb",
"gjb3gix",
"gjb4xiz",
"gjc8nym"
],
"text": [
"Mainly size, proportions, and body fat. Babies are obviously smaller than adults of the species. The ratio of eyes to face, head to body, and limbs to body is different in a baby than an adult creature. They often have more body fat than adults, too. It’s the combination of all three that give them that “baby” appearance.",
"They are very smol. Seriously though, they usually look underdeveloped. Small, clumsy, oddly proportioned, fur or feathers not all there, etc.",
"For mammals at least, the growth pattern is similar across species. So relatively smaller snouts, large foreheads, and especially large eyes are all characteristic of babies.",
"Their small size. Also babies’ heads are huge relative to their bodies in many cases, like with h7mans or kittens.",
"Not sure if this is true or not but I've heard that babies look the way they do because they appear less threatening to adults this giving them a better chance of not being attacked. This seems to work with other animals too as they will instinctively protect a baby of another species even if they're not species that normally coexist - think a dog protecting a duckling. Not so much with predator/prey species of course.",
"In German (of all languages) there's actually a word for it: Kindchenschema. Probably because the Austrian zoologist Konrad Lorenz described it first. All young animals, at least of higher animals, have a similar appearance: Shorter faces (short beak/snout/nose compared to the adult), comparably large eyes and the proportions of the body are \"off\", humans for example have disproportionally large heads as babies, for most dogs, it's the paws. This feature triggers an emotional response in us and makes us want to protect these animals. We find them \"cute\". Which is arguably a survival trait, considering that our babies are highly dependent on adult support to survive. One can see the same \"protective\" trait in other animals that have a similar high investment in brood care."
],
"score": [
14,
12,
6,
5,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxmnyz
|
why can’t we remember being babies? Or even being in the womb?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjba71i",
"gjb607y",
"gjb664c"
],
"text": [
"The human brain is very big and very complex, from a biology standpoint. The human birth canal isn’t. We’re born with tiny (relatively speaking) brains so that our skulls can compress to pass through a vagina. Sections of the brain, such as those devoted to long-term memory don’t develop until years after birth.",
"I’m 22F and my earliest memories are probably from around the age of 3 or 4. 4 and onward seem pretty clear. 3 is a little cloudy but I have a few memories. I even remember being about 4 and questioning why I couldn’t remember being 2. It’s almost like my consciousness only faded into existence around the age of 3. My twin sister (fraternal) says her earliest memories weren’t until she was around 8 or so. I can remember things that happened to her (like the exact events of her breaking her arm in preschool) that she can’t remember at all. What causes people to forget being really young? And why is it different ages for different people?",
"Because we didn’t have a conciousness then. Basically, we are just a very helpless animal for the first years of our lifes. Nothing \"human\" about us."
],
"score": [
12,
8,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxn0yy
|
How are so many things considered discrimination when hiring people, but when hiring actors/actresses, nothing but discrimination is considered okay?
|
I don’t feel strongly about anything related to this, but I am genuinely curious why this is allowed?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjbbkgb",
"gjb91f6",
"gjbay5i",
"gjbb84m"
],
"text": [
"Discrimination is generally always legal if it's actually a job requirement. Virtually all normal jobs don't require a particular race, gender, ethnicity, sexual orientation, etc. so those are basically defacto illegal (at least in the Western world). But you're totally allowed to discriminate on real requirements, like professional certification (doctor, lawyer, accountant, engineer), required skills (ability to type, ability to speak a particular language, abiltiy to use a particular tool or software package), or physical abilities (able to climb stairs, able to lift X lbs) if those really are part of the job and can't be reasonably accommodated. Actor/actress is one of the weird ones where physical appearance really is a job \"requirement\", given that it's a large portion of what the job is. If the writer/director called for a tall female character, yes, you could put a guy in drag and lifts but that's really not what the role calls for. Anything involving artistic license is also going to have to have pretty wide discretionary latitude.",
"When hiring people, you are allowed to discriminate regarding traits that are relevant. Nobody would care if I chose someone with a good STEM SAT score for a science position, but it would be a little weird if that was a prerequisite for an actor. Of course, people discriminating against actors based on SAT scores isn't a widescale societal issue, so it isn't illegal.",
"An acting role is generally considered a job with a bona fide occupation requirement. Basically, there is a reason (fitting a role a writer wrote) to discriminate so the government allows it .",
"Jobs are all about discrimination as well, the term has just become loaded and shorthand to mean \"illegal discrimination,\" which is based on a protected class. For example, a door with a sign that says \"pull\" effectively discriminates against the illiterate, right? But that's legal because literacy is not a protected category"
],
"score": [
23,
12,
4,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxn10q
|
why, when visiting very old grave sites, are the graves sunk into the ground a few inches? Isn't it usually the same amount of dirt that is dug up and replaced, with the addition of the body plus its container?
|
Title.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjb8fin"
],
"text": [
"The body and casket compress the dirt below it and sink a bit, so the dirt on top of the casket does as well."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxnk4c
|
How do glasses work?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjbboh0"
],
"text": [
"Light traveling through a transparent/translucent medium changes direction based on the makeup of the medium and the angle that the light strikes it. Lenses in your eyeballs work the same way as lenses of glasses: the curved surfaces bend the light such that it becomes focused at a specific distance (your cornea). Pour a glass of water. Now dip your finger in it and look at it from the side. You'll see how the light gets bent and redirected. That's a lens."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxo37w
|
why when trying to recover after vigorous exercise, does your respiration slow faster if you breathe in through your nose and out from your mouth?
|
Is this just a technique so you control your breathing so that you don’t gasp, or is there some anatomical reason why that type of breathing works best?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbhwnr"
],
"text": [
"Breathing in through your nose allows more oxygen to get to your muscles. When you breathe through your mouth, you have to \"gasp\" more because more carbon dioxide is offloaded, making it harder for all your tissues to get enough oxygen. So breathing in through your nose is basically more effective and efficient, which is why we don't need to breathe as quick. [This study]( URL_0 ) goes more in depth into this."
],
"score": [
5
],
"text_urls": [
[
"https://www.researchgate.net/publication/325521734_Effect_of_Nasal_Versus_Oral_Breathing_on_Vo2max_and_Physiological_Economy_in_Recreational_Runners_Following_an_Extended_Period_Spent_Using_Nasally_Restricted_Breathing"
]
]
}
|
[
"url"
] |
[
"url"
] |
kxo9j7
|
i dont understand porch piracy?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjbftjl",
"gjbg0hq"
],
"text": [
"It costs extra for \"signature on delivery\" or \"registered\" services. If nobody is home typically it will be taken back to the depot. Often when you order items online it doesn't include the option for signature on delivery. The default is usually to leave it but with some services you can leave alternative instructions via a website or SMS response. I don't allow anything to be left on my doorstep.",
"Sometimes I actually have to *pay a premium* for a courier that allows me to *waive* signing for packages. Because they ALWAYS get delivered when I'm working my 9 to 5 job, like almost everyone else. Many people, like me, would rather risk the package theft and allow the package to be delivered unsecured by signature than have to wait two or three extra days for delivery attempts to inevitably fail only to have to drive all the way to the courier's warehouse or post office to pick up every single package they order. That's if the shipping option selected even comes with a signature option, which sometimes is a premium charge that the sender has to pay for. If you're a sender and you want to send packages cheaply, and are willing to take on that risk of an unsuccessful delivery, you can save some money by opting for no signature confirmation. It's simply a cost/benefit analysis."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxooip
|
Why are some commercials on TV so much louder than other commercials or the TV show itself?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjbi79h",
"gjbi91q"
],
"text": [
"Technically they have the same peak levels. That’s the only thing the FCC regulates volume-wise. TV shows don’t operate at peak volume the whole time.... that explosion or fight scene might be loud but it’s only for a second. The commercial airs at that same peak volume but for the whole commercial... and for the why? To get your attention.",
"They do it on purpose to grab as much attention as possible. If you're in a loud room, or you're multitasking or doing something else, or you're dozing off, that commercial wants to interrupt you and get your attention. They can do that by being loud and obnoxious. As for why they're specifically different volumes than a show you may be watching, it's because there's no way to know ahead of time what program your ad will be dropped in the middle of, or where the TV network decides to put the breaks. Films are shot for theaters where they aren't supposed to be interrupted, so they often have audio dynamics tailored to the full film experience. When a broadcaster cuts it up and shoves loud obnoxious commercials into the gaps, you can get some pretty nasty volume shifts."
],
"score": [
15,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxp1k4
|
Why is our running vertical jump higher than standing vertical jump?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbjv51"
],
"text": [
"Because the boost of the muscles already in motion instead of a solid position propels us higher."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxpfu8
|
How do we get weaker when we get older? What is happening inside of us from a physiological perspective?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbmr1z",
"gjc4oki"
],
"text": [
"It's called \"sarcopenia\", and it's because the number of muscle fibres is reducing and the ones left are less able to contract than they were. I believe the underlying cause for that is calcium leaking into muscle cells and damaging their mitochondria. It's interesting to note that this is actually a very similar process to what happens in the disease muscular dystrophy, but just caused by age rather than a genetic abnormality.",
"This can partially be offset by resistance-training (weights, bands, magnetic, body-weight, whatever...) as you age. You don't have to go nuts with it either. Just get you butt of the sofa and \"work\" your muscles instead of letting them atrophy."
],
"score": [
37,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxplkm
|
Why is Dec. 21 considered the beginning of winter when it's the day that gets the least direct sunlight? Wouldn't it make more sense for it to be the middle of winter?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjbn2t5"
],
"text": [
"I can think of two reasons why the current system makes more sense. First, the start and end of the seasons have specific astronomical landmarks. On the first day of North American winter, the sun is at its most southerly declination, it is at its extreme southerly position. Three months later on the first day of spring, the sun is lined perfectly with the equator; it is dead even. These moments are much easier to observe, especially back in the day when you only had primitive observation tools. So, since terminals of the season at are landmark moments, they are easier to recognize. Second, it also makes more sense due to the temperature lag on Earth. 21 Dec is not the coldest day in the North Hemisphere even though it is the day when the sun shines the least. Because water takes a long time to change temperature, it doesn't really get cold until late January. If 21 Dec was the midpoint of winter, then it would technically be spring in late February, during a time when many parts are still covered with snow, and will be for another month. In places, the snow would not be gone until summer. So, the stay consistent with the theme of the season, it makes more sense to have the season start on the solstices and equinoxes."
],
"score": [
14
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxplwm
|
Why does ferro fluid form spikes?
|
The magnetic fields are uniform around the magnet so why not just a blob of liquid ? What leads to spikes?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjbr64o"
],
"text": [
"Ferrofluids and magnetorheological fluids consist of particles in a carrier fluid. When a particle becomes magnetized it has a north pole and a south pole. The north pole of one particle will attract the south pole of other particles and they will tend to line up just like iron filings around a magnet. Two bar magnets always want to lie end to end and do not want to be next to other bar magnets so they separate into lines and spikes."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxpz38
|
why amd and intel name their chips “3, 5, 7 and 9”? Why are they skipping numbers, and why do both companies name the chips the same way?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjbozjg"
],
"text": [
"CPU's have an even number of threads and cores. In the past this led to confusion with people not being able to tell the difference between an \"intel core duo surge extreme\" and an \"intel core 2 turbo\" or whatever. So intel intentionally made the i3/i5/i7/i9 designations odd numbers so customers wouldn't mistake it for the number of cores/threads, which it isn't, it's just a kind of arbitrary designation of the relative power of that core for that generation. I don't know anything about AMD though."
],
"score": [
33
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxqbjf
|
How is information transmitted through wires?
|
Take a simple USB cable. It’s just a small array of conductive contacts and metal wire. Obviously the computer/device decodes the information but how is that information communicated? Morse code?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjbrdj4",
"gjc2oc4",
"gjc2c0s",
"gjbra57",
"gjc4rol",
"gjc7m5c"
],
"text": [
"For copper/metal wires like that its basically morse code, you just toggle the electricity on and off real fast. In a usb cable and other such cables there's also often multiple wires woven inside the isolating sleeve to allow for more information traveling simultaneously. What's really interesting is fibre optic cables. These ones are made from (i think plastic) transparent fibres, and instead of running a current through it, you shine light into the fibre in a particular angle, such that it bounces off the walls of the fibre and stays inside, so you can see the light coming out the other end. These cables carry a lot of information, because not only can you wrap many of these fibres into one cable, you can also shine multiple different colours (wavelengths) of light into a single fiber, and they won't interfere with each other. Then you again just toggle the different colours in each fibre on and off really quickly to transmit information. Also note that its not actually morse code, its simpler because in computers all data is already in the form of ones and zeros, so you just transmit it raw.",
"At the basic level, voltage. If the wire is short enough (good approximation for the simplest stuff) you can think of the process as someone putting either high or low voltage on the wire and the guy at the other end can instantly check whether the voltage is low or high. Morse code of telegraphs itself is based on some variation on this theme, although the information is carried by duration of pulses. There are, however, a number of practical considerations. The guy at the other end checks the level, all good... but when? If the voltage stays high for 1 s, is it 1 \"1\" or 100 \"1\"s? How do we manage \"noise\" on the line, caused by some external interference? Who says when we are transmitting and when we are doing nothing? Who wins if both sides of the cable want to transmit at the same time? What happens if the cable is very very long and the propagation time is actually significant? The solutions are many, the problems depend on the application and that's why we have a number of protocols and cables and whatnot. If you have metal wires, it is always changes in voltage. More wires may be required if you want to also bring power instead of data only (e.g. USB, SATA), or if you have additional information that you want to send on the side for some reason, or you want bidirectional simultaneous communication, or you want your data to come byte by byte instead of bit by bit. Stuff other than wire can be used as the actual medium not using voltage, but requires transducers of some kind (antennas for wi-fi, some kind of LED wizardry for fiber). If the wonder comes at what we can do with just those four little wires inside the USB cable, know that it is but voltage changes sending ones and zeroes... but there are a lot of them. Hundreds of millions every single second. The same exact information could be transmitted with any other protocol, with some being faster and some being slower. I work with I²C which is an almost 40 years old protocol made to connect many chips in the cheapest possible way (quite literally, 2 wires around the board and let's say one hundred chips all connected to them), and even that can transmit millions of bits every second.",
"Simple answer: yes. & #x200B; More complex answer: We use better codes than Morse, that is easier for a computer to handle. But otherwise, yes. & #x200B; Fun fact: The same kind of codes are used to store data on a medium like a tape, CD or magnetic disk like floppy or hard drive. (But not SSD.)",
"The computer will send electrons through the cable, or light if it's fibre, and uses binary code, on/off representing 1's and 0's.",
"ELI5: Its like morse code but much faster. Check out the book Code: The Hidden Language of Computer Hardware and Software by Charles Petzold. The author explains this and much more in an easy to understand way.",
"USB is a really bad example, it's pretty complicated since it's a differential protocol, but in general, for simpler protocols, it is actually some kind of Morse code. Take the old serial protocol. What happened here was that in the wire that connected the two computers, the power was turned off and on in rapid succession at a specific speed, for the sake of this argument, let's say every millisecond you could either send 12v or 0v on the cable, and both computers knew that this was the speed they worked at, then all they had to do was to define what a certain number of pulses meant, similar to Morse code."
],
"score": [
111,
6,
5,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxqw7k
|
Why do we sneeze if we look at the sun for a second or rub a feather on our nose?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbuuv2"
],
"text": [
"The photic sneeze reflex (also known as Autosomal Dominant Compelling Helio-Ophthalmic Outburst (ACHOO) syndrome[1] or photosneezia, from the Greek φῶς, phōs, \"light\" and colloquially sun sneezing) is a reflex condition that causes sneezing in response to numerous stimuli, such as looking at bright lights or periocular (surrounding the eyeball) injection. The condition affects 18–35% of the world's population,[2] but its exact mechanism of action is not well understood. (Source: wikipedia) And from what ive learned in school. The nerves that normally trigger a sneeze are somewhat connected to the nerves that get triggered through light. Thats why when you feel the urge to sneeze but cant really do it, looking at a bright light could make you sneeze."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxqybs
|
Why do we get a sore throat after being in the cold for a while?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjc2ku6",
"gjc26ko",
"gjc2nz7"
],
"text": [
"Well it depends on what kind of cold. But often the air is very dry when it is cold, meaning a low humidity. This means it is easier for water to evaporate into the 'dry' air. What you should also know is that water evaporates at all times but the speed at which this happens differ depending on temperature and humidity. Higher humidity meanind lower evaporation and vice versa, and also a higher temperature gives a higher evaporation and vice versa. Now to why you get a sore throat. Your body is around 37C on the inside and every time you breathe out some water from your throat is evaporated and taken with the air, removing it from your throat. Normally this evaporation happens at a speed that your body can keep up with by 'refilling' the water that's lost. However when the air is really dry, like with cold weather, the evaporation happens at a faster speed and your body can't keep up. This results in your throat quite literally drying up and gives you the sore throat feeling. Also this process happens faster when you breath through your mouth, so to prevent this happening as much as possible try to breathe through your nose. As there is more resistance that way which will recapture some of those water vapors.",
"As a Canadian, this is something I think we are fortified against. Could you maybe have post nasal drip due to dry/cold weather",
"In school, we learned that cold air can hold less moisture by itself, so to create sort of an equilibrium, the body gives off more moisture then it would with warm air. Your nose also produces more moisture/ fluid to counteract drying out. It's the same effect as steam passing through a buildings outer hull towards outside in the winter and the inside in the summer. The later effect just isn't that severe that we have to use water resistant building materials in the inside."
],
"score": [
163,
19,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxr98v
|
If humans all originated from one place, how did various races end up developing different physical traits?
|
E.g. Nordic people are usually taller than most and Asians have thinner facial features.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbwnig",
"gjbyrz8",
"gjbvyk3"
],
"text": [
"Partly some minor evolution, as well as bottlenecks. For the evolution part, humans need to absorb a certain amount of sunlight to be healthy. It helps us make vitamin D as well as absorb a bunch of nutrients. When you move away from the equator, the sunlight becomes weaker, therefore humans with lighter skin did better and over time these genes spread to everyone in northern regions. Different traits are helpful in different biomes/habitats. Random mutations can also occur, like blond hair or blue eyes, to further differentiate groups. Bottlenecks occur when a small group leaves to start a new population. Let's say we have a ship of 100 people to colonize Mars. By random chance, there are 25 Japanese people and 5 Caucasian people, and 70 very dark skin African people. After the ship leaves, World War 3 breaks out and no one from Earth goes to Mars for 400 years (it's a long war). Once we reestablish contact, the \"Martians\" will appear predominantly dark, with slightly Japanese traits (as those are the predominant traits of the group that first established them), even if they number 500 or more. If we left them alone long enough, further mutation and adaption to the Martian planet would make them into a more distinct ethnicity. After thousands of years alone on Mars, they might become too genetically distinct to even have children with Earth humans, and BAM! We'd have another species. If you keep two populations apart long enough, mutation and adaption to their environment will cause them to drift apart, genetically speaking. If this happens long enough, you'll get totally different species. Did that make sense or was it too confusing?",
"\"Asians have thinner facial features.\" -- What kind of Asians are you on about? East Asians certainly have broad facial features (larger average bizygomatic/bigonial breadths, wider noses, interpupillary measurements etc--this goes for almost every conceivable metric) relative to West Eurasians.",
"By means of long time and relative isolation. The populations that spread out from our African origin formed separate communities that didn't mix much and developed differently. Why they developed differently can't be answered in a short statement. There are multiple effects. Some is environmental. For example, if you look at the Inuit, they are generally short and stocky. A body shape that helps to reduce heat loss - very helpful in the arctic cold. Then you have sexual selection. If your culture values blond and blue-eyed people, blond and blue-eyed people have a higher chance to reproduce, so you get more of them."
],
"score": [
15,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxrg89
|
Why are men so much more romantically desperate than women.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbvttz",
"gjc10da",
"gjbxala",
"gjc151f"
],
"text": [
"Society teaches men that confidence is based on having sex. Society teaches women that having sex is shameful. These pressures are then lived out and appear as statistics.",
"Another contributing reason is that men tend to be limited in where they could find emotional or physical intimacy. For women in many cultures, it’s not strange to have close friends who you could confide to or cuddle with. Women tend to have better support networks. In contrast, many cultures discourage men from being emotionally or physically affectionate with anyone except their significant others - and even then, only in limited ways. That means for many men to fulfil their needs for intimacy, they need a romantic partner. Desperation can easily ensue. That’s something we can all help change. We can all help normalise emotionally open friendships for men, where the conversations can go further than shittalking, where burdens can be shared and halved, where a long embrace wouldn’t be out of place.",
"Because any woman whos even half decent looking just has to be there to get guys attention, where as guys have to really put in work to impress a woman. As a result, decent looking women always have men chasing them but guys who don't put in the effort or have the charisma to approach women will have none. Thats why so many men are on dating sites.",
"Options. It's a common social expectation across cultures for men to pursue women (romantically), and for women to wait for men to take the (romantic) lead/initiative. Therefore, a man might pursue 10 different women over a period of time, and only find 1 who does not reject him, leaving him with only 1 option to choose from - so he cannot be highly selective. Conversely, a woman might have 10 different men pursue her over a period of time (each of whom might have already been rejected by other women), giving her 10 options to choose from - allowing her to be more selective."
],
"score": [
22,
10,
4,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxrpnc
|
Why can't you "hold in" menstruation?
|
Your uteris/vagina has (I'm assuming) much stronger muscles than your bladder, yet it can't do anything to hold in menstruation whereas your bladder can voluntarily hold in urine for a very long time if necessary. Why would your body let you delay the release of one waste product until it's a safer/more convenient place to do so but not another?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjbxba2"
],
"text": [
"the uterus is completely different organ than a bladder. during menstruation the cervix, the opening to the uterus, opens involuntarily. it does not contract like the urethra, which can be voluntary, the dilation of the cervix is an automatic response like a heartbeat, or pupil dilation. Kegel muscles do not contract to the degree that a liquid will not escape the vaginal cavity."
],
"score": [
27
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxryx3
|
How does water evaporate from puddles if it boils at 100 degrees? Are individual molecules being heated to that by the sun's rays?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjby7ls",
"gjbzrrd"
],
"text": [
"You are quite close. Individual molecules can be heated by the suns rays. But evaporation happens even without sunlight. Whenever molecules bump into each other they transfer thermal energy between themselves. But these transfers can be quite chaotic and it is not unusual for one molecule to get a lot of thermal energy in the collision. Most of the time this would equalize again in the next round of collisions as the molecule would give away its thermal energy to another molecule. However sometimes the molecule that ends up with lots of energy is close to the surface and may end up getting away from the surface before it hits another molecule. That is mainly how things evaporate.",
"Things are liquid because the individual molecules move around. And they move around at different speeds - the temperature of the water comes from the average speed, but there will always be some that are going much faster. In a puddle, some of the molecules are moving fast enough to break free from the surface. You can think of each molecule as having a temperature, and some of them being hot enough. Additionally, there will always be some water molecules, as vapour, in the air, that are slow enough to condense back into the water surface. When we say water is boiling, it means that there are many molecules hot enough - with a high enough speed - to 'jump' out of liquid state even below the surface, creating bubbles of gas that rise to the surface."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxsio1
|
Don’t endangered species being bred in captivity end up causing multitudes of problems regarding inbreeding? Is this just ignored for the sake of keeping the species alive?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjc0or6",
"gjc0jvz"
],
"text": [
"Not necessarily. There should be enough genetic diversity in the surviving population that will allow endangered species to avoid inbreeding issues especially if bred and raised to be released, but most are not raised that way. That is why most zoos globally have a program where their breeding capable animals are traded around the globe in order to keep genetic diversity up. For instance I lived near Pittsburgh, Pennsylvania. The Pittsburgh Zoo has one of the few breeding capable male elephants in the US. So every other year he would be sedated and transported to other zoos with females.",
"That's why zoos swap around animals internationally. The London zoo might ship a tiger off to Tokio and receive one from Rio de Janeiro, just to stir the gene pool around."
],
"score": [
8,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxsjq3
|
Why is there one doctor for ear, nose, and throat? What is the connection?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjc0ihe",
"gjc0lml"
],
"text": [
"The ears, nose and throat are interconnected, and several conditions and problems encountered in them often affect more than one of these parts at a time.",
"They are all interconnected through a series of air passages. These help equalize the pressure behind the eyes and ear drums and can also carry liquids such as tears and mucus to the correct areas. These passages do occationally get infected which is one of the reasons why there is doctors specializing in this area."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxsz1i
|
What is the vanishing gradient problem in deep learning?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gjc56o7",
"gjcfjd7"
],
"text": [
"If you put a ball on the top of the mountain, it'll roll downhill - until it hits a valley. In optimization, this concept is called a \"gradient descent\": You pick a point and then move in the direction of the steepest slope (gradient) until you find a valley. The valley is, ideally, the best way to do something. So for example, if your goal is to train an image recognition algorithm, you change a bunch of parameters and then calculate the accuracy of recognizing some example images. Then you select the change that gives you the best result (the gradient), discard the rest and do this again, until you can no longer get any better results. The vanishing gradient problem means that tweaking the parameters doesn't change anything. In our example with the ball rolling down a hill, it would be the ball getting stuck on a frozen lake instead of a valley. This is problematic because you don't know if there's a hole somewhere in the frozen lake, or if it's really as good as it's ever going to be. This is related to another problem with gradient descent: The local optimum. This is what happens if the ball comes to a stop in a valley on top of the mountain, rather than getting all the way to the lowest point. For example if you have an image recognition algorithm, it corresponds to a \"model\" (meaning: a bunch of numbers that are used to recognize things in images) which gives you the most accurate image recognition.",
"The other answers do a good job of explaining gradient descent but leave out some details on the vanishing gradient problem in deep learning. With the traditional sigmoid activation you'd get very small gradients at the tails of the function. Combining that with a deep model with many deep layers you get a bunch of small numbers multiplied by more small numbers and end up with almost zero change to your model weights in each training epoch causing your model to stall out in training. This is the vanishing gradient. The ReLU function doesn't have these small tails like the sigmoid does so you can get larger gradients even in very deep networks. Add on more advanced gradient descent algorithms (like Adam) and you can train much deeper networks than before."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxtc7k
|
How does data get transferred via Bluetooth?
|
I get how information can transfer via wires, but I don't get how we can transfer information without a wire, how does it work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjc4gzn",
"gjc4jve",
"gjc5942"
],
"text": [
"Bluetooth uses radio waves. Inside every Bluetooth device is a tiny radio transmitter and receiver. Because the transmitted power is very low, the range is short, just a few meters.",
"Wireless data transfer uses some form of frequency shift keying, usually Gaussian frequency shift keying. Basically the frequency of the wave is slightly different depending on 1 or 0 is sent. Clever encoding schemes are also used on the data to ensure that not too many 1s or 0s are sent together. Here's( URL_0 ) a good Wikipedia article about it.",
"Radio transmission technically microwaves but that is just a change in frequency. So like broadcast TV, radio, or anything else that uses radio waves for communication. If you have a wire of the appropriate and an electrical signal that varies over time it will give off a radio signal of the same frequency and change in amplitude when the electrical signal changes. The wire will have an appropriate shape for the transition and we call them antennas. If the radio wave hits another antenna it will create an electrical signal in it. All wires will transmit radio waves like the but if the wires is not of appropriate length and shape it will have low energy content. So Bluetooth creates a signal with 2.45 GHz and sends it to the antenna. It has encoded the data in the shape. Encoding data in a wave is what we do when we speak and form different sounds. For computers, the signal is closer to morse code than humans speak but the general idea is the same. You encode the signal in a wire base on the same principle, which changes over time."
],
"score": [
6,
3,
3
],
"text_urls": [
[],
[
"https://en.m.wikipedia.org/wiki/Frequency-shift_keying#Gaussian_frequency-shift_keying"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxtpcw
|
Do black holes have an internal structure? If so, how might the internal structure be probed?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjc8bel",
"gjc6db5"
],
"text": [
"As far as I know, nobody knows, and it can't be probed. Anything inside the event horizon is cut off from the outside universe and no information from it can ever get out.",
"In a certain sense yes. The internal structure is of geodesics in warped spacetime. We think we have a pretty good understanding of what space-time is like inside of a black hole, at least right up to the point that it approaches the singularity, if such a thing even exists. As far as any other internal structure, like what is actually in there, what the stuff that fell in looks like, no, we have no real idea what's going on with the stuff that enters a black hole."
],
"score": [
5,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxtqhs
|
- if clouds are made from water evaporation, why are there more clouds and rains in cold areas (nordics/Scotland) than in hot places (Greece/Dubai)?
|
Surely seas will evaporate more readily in hotter parts of the world and less readily in cooler parts of the world. I would have thought when the air temperature is 1-3degrees Celsius there would be next to no evaporation?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjca37a",
"gjc6gmr",
"gjchm1v",
"gjc7o5f"
],
"text": [
"You also need condensation. If the air never cools, the water won't condense. There are a lot more factors, that's all I can think of atm.",
"You premiss is only half way right. In order for a cloud to form you need several factors combining, and humidity is only on of them. You need the right air pressure for example. Regarding temperature, once the water evaporates, it also need to be cooled down to form a cloud. So if the air is too warm, it won't condensate in a cloud, and it won't form. P.S. I wrote this by memory, it might be a bit too simplistic of an explanation. P.S.S. I remember a few years ago was made an experiment, and some people managed to create a cloud in a room. I'll link it below.",
"Warm air can hold more water than cold air, thus for clouds to form in warm areas, much more water needs to evaporate than in a cold area.",
"Warm ait can take more water than cold air, so the warm air full of water moves to the colder area and thats where it cant hold it in anymore and it rains."
],
"score": [
5,
5,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxu082
|
If I choose a random number between 0 and 1, shouldn't the probability of choosing 1 number out of infinitely many be 0 and in turn prevent me from choosing any single one of them?
|
Let's assume I choose 0.45. But as stated, the probability of that event happening should be 0 because there is an infinite number of equally likely alternatives. So in turn, it shouldn't be possible to choose this number. In general, it shouldn't be possible to choose any number. How can this contradiction be resolved? & #x200B; Thank you very much!
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gjc8sz5"
],
"text": [
"The probability of getting any particular number is probability 0, but that doesn't mean it's impossible. The reason for this is that we're dealing with a continuous set of numbers, not a discrete set, and the rules for dealing with probability are different here. In this context, we don't ask 'what is the probability that x is precisely 0.45', because it's 0. Instead, for example, we look for the probability that 0.44 < x < 0.46. We deal with probability densities over a range, not of discrete numbers. It is a bit weird that you can have a range of numbers where each individual number has a probability 0, but the range as a whole does not. But that is the case. Using probability densities is more sidestepping the problem than it is solving it, but it's the practical solution. If you want to know more, 3blue1brown did a very good video on probability densities [here]( URL_0 ) Another thing to keep in mind is the difference between asking about the probability of x being _precisely_ 0.45, rather than being 0.45 to an accuracy of 3 significant figures. 0.450001 isn't precisely 0.45, but if you only care about the accuracy to three significant figures, that doesn't matter to you. So you could write this as the probability of 0.445 < x < 0.4549, and still get a meaningful answer"
],
"score": [
23
],
"text_urls": [
[
"https://www.youtube.com/watch?v=ZA4JkHKZM50"
]
]
}
|
[
"url"
] |
[
"url"
] |
kxv5yl
|
Why is radioactivity damaging to robots?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjcf2v7",
"gjceddn"
],
"text": [
"Most memory/data storage is not radiation hardened. DRAM and SRAM are particularly susceptible to bit flipping due to radiation. This is a big deal with satellites and any equipment meant to last in space. There are techniques that can be used to radiation harden electronics, though they typically aren’t done outside of space equipment and specialty scientific equipment.",
"Radioactivity messes with the bonds of the molecules. Just like it corrupts the bonds in dna molecules, it can also harm the microchips inside robots, which are as sensitive as dna molecules."
],
"score": [
13,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxvbit
|
- why does liquid sometimes dribble down the side of what you are pouring from instead or out and over the rim into what you are aiming for?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjcfcl7"
],
"text": [
"Due to adhesion. There is a number of forces that act between substances. Some (like gravity or electromagnetism) act over pretty long distances. Some others (like the van-der-waals-force, which you might have heard of) only act over very short distances. Its a mix of those forces (in this case, mostly the short-distance ones) that make the glass and the water attract each other."
],
"score": [
13
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxvcza
|
Why does salt make water boil faster?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjcfygo"
],
"text": [
"It does not. Actually, adding salt raises the boiling point of water, though the effect is quite small. If you drop salt grains into super heated water it will boil because you've added boiling points, but putting in sand of the same size has the same effect."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxwu8p
|
Why do indoor temperature feel more extreme than outdoor temperatures?
|
For example, 65 degrees indoors feels so cold, but 65 degrees outdoors is really comfortable. 75 degrees indoors is hot and uncomfortable, but 75 degrees outdoors is pretty much perfect.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjcsc7n",
"gjcofju"
],
"text": [
"Someone else covered it great, but I also want to point out that when you’re inside, you’re often just sitting and doing very little. Outside you’re moving. If you walked around inside like you walk around outside, you’d be hotter.",
"The human body does not sense temperature, that's why we have \"feels like\" and \"wind chill\" and thermometers. The human body senses heat flow. Sure, heat flow is more when there is a large temperature difference and less when there is a small one, but there are many more factors. Wind speed, sunlight, humidity, ... all effect heat flow and thus \"how cold it feels\"."
],
"score": [
8,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxx63a
|
How "https" implementation is done does it costs website owner?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjcr86z"
],
"text": [
"The website owner has to purchase an SSL certificate for the site domain in order to provide HTTPS services, but there isn't any additional expense beyond that (other than configuring the site to listen on a different port--HTTPS uses 443 whereas HTTP is 80)."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxxkbr
|
Where do these trillions of dollars come from?
|
In the USA, we have recently had a few multi-trillion dollar relief plans. But where does all this money come from? More specifically, if situations were different, where would it have gone instead? Do they just print it/will it into existence and further inflate our currency?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjcszh4"
],
"text": [
"The US government borrows it from investors. US treasury bond interest rates are near record lows, as the security of the US government appears valuable to investors. It's never been so cheap for the US government to borrow money, and they are borrowing a lot as a result. Printing money is more about people not liking germy old money than it is about monetary policy. That said, print production is up. Coin production is unable to meet demand."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxy2pi
|
Why do we feel there is a need to brush after we wake up but if we don't sleep it doesn't feel so bad in the mouth?
|
When we wake up if feels so dirty in the mouth that you have to brush your teeth but if don't sleep for the same hours, it feel normal.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjcxwbc"
],
"text": [
"When you are sleeping you aren't eating, drinking or spitting as well as breathing very shallowly so the stuff that makes your mouth gross just builds up."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxyi2v
|
Data forensics - can your deleted files really come back?
|
Hi, can someone please explain this to me - I read many articles that say that if you sell your phone whether you do factory resets or not, your files can be retrieved because the phone doesn't actually get rid of the file but rather sort of deletes the pathway to the file (?) and replaces it with anew. So my question is, is this still true? If so, does encryptinv your phone change that? (the encryption for example found in settings on an android) I've also read that android phones now come encrypted so as long as someone doesn't know the password they can't get to your files and furthermore that even if they could through data forensics it'd be useless because of encryption? I'm so sorry for the long questions. There's just ps much misinformation and disinformation, I don't know what to believe. I'd like to be able to sell my old phone, that's why I ask.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjd02w6",
"gjd1pz0"
],
"text": [
"Data is stored as a bunch of 0s and 1s. When it is deleted the 0s and 1s aren't changed until they are written over, only the information telling the computer where the data is stored is written over. Since the actual information isn't actually gone it is possible to look over the whole disk and relocate the information. Encrypting the data doesn't change how the information is accessed but undeleting a file that is encrypted doesn't change the encryption. The file is still encrypted and without the encryption key getting usable data from the file is difficult. Depending on what type of encryption is used breaking the encryption will be more or less difficult but even the simplest encryption is not easy to crack. Making deleted files un recoverable is as simple as just writing over the parts of the disc that have the data on them. For your example with a phone the easiest way would be to reset the phone then put a large file on the device and copy it enough times to fill the device then delete everything. That would overwrite the entire disc and make anything other than the large file you copied unrecoverable.",
"Pretend your hard drive is a stack of whiteboards labeled 1-3. You also have a small whiteboard that acts as your table of contents. Next, you draw stuff on all the whiteboards and then you write what you drew in your table of contents. So now your tiny whiteboard is telling you what's on all the other ones: 1. Picture of a horse 2. Math homework 3. Picture of a mustang (car, not horse) OK, now say you want to delete the picture on whiteboard #2. The computer doesn't actually go and erase the whole thing, it just erases the entry in the table of contents. Next time you draw a picture, you see that whiteboard 2 is available. Only when you put something new on it, does the computer bother to change the information content. Until then, the old info is just sitting there and can be recovered."
],
"score": [
5,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kxyzuf
|
where do you banks and investment firms store their records that make it “unlikely” that our money will be lost
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjd2awr"
],
"text": [
"Historically, they stored it on paper ledgers that were copied and stored in different locations to ensure no one loss would destroy them all. Today, they're stored in electronic records that are backed up to storage around the world. Short of a catastrophe that destroys all global electronics - in which case you definitely have bigger problems than your bank account - they're pretty safe."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxzhp5
|
Why do we find 'things' beautiful. Not people, I get the logic behind finding a person, a 'mate' attractive. But a sunset, a pretty flower, a super car... Why? What is the logic / reasoning for finding these 'things' beautiful...
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjd5egr",
"gjdl392",
"gjezn6u"
],
"text": [
"This is an area of active research so we can’t give you a definitive “why“. One thought is that when we see images that are easily scannable we find them pleasing. Symmetry and landscape orientation are key. It’s thought to provide an evolutionary advantage if we can easily scan scenes or objects when looking for food, predators, prey, etc. It really doesn’t matter whether it’s an object or a landscape, both are images on the back of our eyes.",
"Vibrant colors in general are linked to evolution, differentiating them allowed us to find a variety of fruits and vegetables that were edible. A sunset is nothing more than a myriad of vibrant colors. A pretty flower represents the fragility and sheer awe of nature, and life itself. Where flowers grow, life can thrive. There are appealing colors and satisfying patterns to be found in many plants. A super car is a \"practical\" machine. It grants you the power to move faster than everyone else. It's engineered to be attractive, with shapes and facets and symmetries and patterns we find appealing. We like symmetry because healthy humans and plants we eat are symmetrical. If they aren't, then some unknown mutation or illness may have occurred, leading to unpredictability or the potential for transmutable disease. Tldr: what we find beautiful is linked to procreation and survival. Which also explains about 99.4% of every other trait humans universally share.",
"URL_0 Kurzgesagt covers it really nicely, but I don't think they give a definitive definition. It's beautifully animated. Worth watching just for that."
],
"score": [
12,
5,
3
],
"text_urls": [
[],
[],
[
"https://youtu.be/-O5kNPlUV7w"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
kxzpne
|
Why Are Some Passwords Unbreakable?
|
So today I came across an article which said something like this: "We recommend that people should use six words for their passwords (or five words, plus a character). •Five words are breakable with a thousand or so PCs equipped with high-end graphics processors. •Six words may be breakable by an organization with a very large budget, such as a large country's security agency. •Seven words and longer are unbreakable with any known technology, but may be within the range of large organizations by around 2030. •Eight words should be completely secure through 2050." So My question is what is so special about about 6,7 or 8 letter passwords that it makes them unbreakable while the 5 letter is easily breakable. How can just some 1-2 additional letters can make a thing impossible to solve?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjd7qrk",
"gjd67wj",
"gjd6xad",
"gjd789e"
],
"text": [
"They are not talking about letters, they are talking about actual words. The difference is that there are only 26 possible letters but there are thousands of words you might end up using even though it is roughly as easy for humans to remember words as individual letters. This concept have made its way into all known standards and all but a few legacy policies is recommending that you use passphrases of several words rather then random letters and numbers. But the reason for why just a single additional word increases the difficulty by so much is due to exponential growth. For example my laptop is able to crack a hash of an 8 character password in about five minutes. That does not sound that long. But if you add another character then I would have to try as many passwords for each of the possible extra characters. So the time is then 5 min x 26 = 130 min or just over two hours. So just one extra button press in your password cause my simple five minute job to turn into a two hour deal. And if you add another character you make it 26 times as difficult meaning that instead of two hours it takes over two days. This is exponential growth which can quickly go from small numbers to very large. With words it is even harder. Adding just a single word can make the task of cracking the passphrase take ten thousand times longer.",
"Words or letters? Because your whole post says words, then at the end you say letters",
"While no password is truly unbreakable what I believe you're talking about is the difficulty to guess a password of more characters with a brute force method. Brute forcing a password is when you use a computer program to guess every possible combination of characters until it gets the right answer. A computer of a given speed can make a certain number of guesses in a certain amount of time so you can calculate roughly how long it would take to break a password of a given length. Introducing numbers and special characters increases the number of possible combinations exponentially. This is why you should use as long a password as possible with letters, numbers, and special characters. (Also don't reuse the same password on multiple sites and change them frequently.)",
"> How can just some 1-2 additional letters can make a thing impossible to solve? \"Impossible\" is incorrect. I'm guessing they mean unfeasible. Imagine a password made of only numbers 0-9. There are 1000 possible three-character passwords, but 10,000 possible 4-character passwords. Adding a single number makes it 10 times harder to solve. Now, computer passwords are generally made of a combination of 95 characters (26 lowercase letters, 26 uppercase letters, 10 digits and 33 symbols). Which means that adding a single character to a password of this type makes it 95 times more complex to crack. Adding two characters makes it 9,025 times more complex. That's the difference between a password that's crackable in 1 month, versus one that would roughly take 9025 months (752 years)."
],
"score": [
11,
6,
5,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky045b
|
How did we first discover that sunflowers "clean" radiation from soil?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjd9ely",
"gjd9r6c"
],
"text": [
"It is not radiation as such although that is a side effect. The radioactive material that is created during the meltdown of a nuclear reaction is composed of various isotopes from all over the periodic table of elements. What forms into dust that falls down onto the local area is often metallic atoms which forms into minerals when exposed to other reactive chemicals. So what is really the problem is that the mineral in the soil is radioactive. So we need a way to collect up the minerals from the soil but leave the rest of the materials. This is what the roots of the plants do. It is not only sunflowers that is used for this but other plants such as mustard have also been used. And they are not only used to clean up radioactive sites but also other forms of mineral contamination such as lead pollution. You plant the seeds of the plants and then when they grow big you harvest them. At this point a lot of the minerals from the soil have been collected by the roots and is in the seeds of the plant. Then you can burn the plant and you are left with most of the minerals neatly collected in the ash to be disposed of properly.",
"Like many scientific discoveries, it was a solution to a problem that currently exists. Phytoremediation-using plants to extract pollutants from the soil- is a promising field of bioremediation that potentially offers simple, low-cost methods of rehabilitating soil that don't necessarily take decades to produce results. There's a lot of academic work going on to identify plants that excel at taking up and concentrating pollutants in their tissues- everything from heavy metals to radioisotopes- known as [hyperaccumulators]( URL_0 ). Sunflowers were experimentally discovered to have the ability to greedily sequester specific isotopes from the soil because they chemically resemble nutrients the plant wants to have. These isotopes accumulate in the plant tissue, and the plants are destroyed as radioactive waste."
],
"score": [
4,
3
],
"text_urls": [
[],
[
"https://en.m.wikipedia.org/wiki/Hyperaccumulator"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky07s4
|
How is a ball on a shelf potential energy if it’s not moving?
|
I’m using this example because I’ve heard it before.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjd92xy",
"gjd95o7",
"gjd9j43",
"gjdc35a",
"gjdbh49",
"gjda3xz",
"gjdcx5o"
],
"text": [
"This is why it’s called “potential“ energy. It’s is still above ground level and if released from the shelf, has the “potential” to do work.",
"Because you spent energy to lift it up, against the force of gravity, and put it on the shelf. That energy has moved into the ball, but it's only potential energy until someone comes along and pushes it off the shelf.",
"> I’m using this example because I’ve heard it before. If it were moving it would have *kinetic* energy. If it were accelerating due to falling off the shelf it would be converting its potential energy into kinetic energy.",
"In your example of a ball on a shelf, the key is that entire system *also* includes the Earth's mass with its gravitational field. The ball starts at a \"lower height\" in Earth's gravitational potential, and someone moves it against the gravitational field, to put it on a shelf. That leaves the ball at a place that's at a higher gravitational potential. So here's what schools always gloss over, in their rush to get kids answering test questions: At all times, the ball is *not* an isolated system that \"has\" potential energy unto itself. That potential energy lies in the *interactions* of the ball's mass with the external gravitational field. We could call it the \"Earth - ball *system*\".",
"If you remove the shelf, the ball will fall by itself. You aren't adding energy to it, you're not moving it yourself.",
"The same way someone with an IQ of 185 just sitting on the couch has \"potential\" to cause change. They can, they're just not doing it now.",
"Hence \"potential\" If you are to remove the shelf, the ball falls. It takes energy to lift the ball from the ground to the shelf. The energy doesn't just disappear, it is transferred over as a potential. It doesn't matter how long you leave the ball on the shelf, if the shelf goes the ball will fall, turning the potential into kinetic energy."
],
"score": [
11,
7,
6,
6,
5,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky0akc
|
If the moons gravity is strong enough to cause the oceans tides, why do we not feel lighter when the moon is overhead?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjd9t6t",
"gjdbosk",
"gjd9pnr"
],
"text": [
"Because you're a teeny tiny object that's not very stretchy, so there's no detectable difference for you. The ocean is a staggeringly big object that stretches, so it's a lot easier to get an effect.",
"You do, but not by very much. Specifically, you're lighter by [about 3 parts in a million]( URL_1 ) when the Moon is overhead vs at the horizon. That's actually less than the effect of the sun (you're lighter [by about 6 parts in 10,000]( URL_0 ) during the day). (Both of these are numbers at the equator - if you, like most redditors, live in the temperate latitudes the difference is ~3/4 of the numbers quoted here.) In either case, the effect is small enough not to be very noticeable - remember that the effect of the tides is only a few feet on top of an ocean many miles deep. (As for why the moon dominates tides when the sun's pull is stronger: the tides aren't just the strength of the pull, but how the pull *differs* from one side to another. Because the moon is much closer than the sun, the *difference* in lunar pull from one side of the Earth to the other is larger than the *difference* in solar pull, because your distance changes by much more in relative terms. This leads to lunar tides being about twice the size of solar tides, although solar tides still matter!)",
"Human weight is affected by both the moon and the sun but it’s a very tiny fractional amount of weight change. Oceans are far larger and the effect more dramatic."
],
"score": [
10,
9,
6
],
"text_urls": [
[],
[
"https://www.wolframalpha.com/input/?i=%28sun+mass+%2F+sun+distance%5E2%29+%2F+%28earth+mass+%2F+earth+radius%5E2%29",
"https://www.wolframalpha.com/input/?i=%28moon+mass+%2F+moon+distance%5E2%29+%2F+%28earth+mass+%2F+earth+radius%5E2%29"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky0gjh
|
What IS the purpose of horrifying stock photos like the ones that make up r/wtfstockphotos? Who commissions these?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjdaxrl",
"gjdcm0s"
],
"text": [
"A stock photo, *by definition*, isn't a commissioned photo. It's just a picture that someone took, and added to a big *stockpile* in the hopes that someone digging through the stockpile would find it, like it, and pay for the rights to use it. Someone commissions a photo when they don't want to use a stock photo.",
"The fundamental concept of a stock photo is that it is produced without the prior knowledge of how it will be employed. Instead of going to the trouble to get models, props, wardrobe, etc. all so you can make a generic background graphic for some document you can just buy the rights to use one someone else already made. To this end the people producing stock photos will try to optimize their time and effort by making every variation they can think of when their models are in the studio. You get all the normal business interaction photos, the models being serious, happy, sad, angry, uncertain, confused, etc. Then you bring in other things like maybe they are holding a stapler, arguing over a laptop, holding mugs, on the phone... Finally at the end of the day when you have time left but all the main shots are done they get a bit wild, because who knows what someone will want? Maybe your businessman is screaming at a carrot, maybe your businesswoman is pouring coffee into her pockets, maybe they are both fighting to the death with plastic utinsels. The photographer is already paying for their time so they might as well keep shooting."
],
"score": [
33,
21
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky1chs
|
Why is the existence of a middle class important in assessing the strength of an economy?
|
Is it because they spend their money while having some saved up in case there is a downturn? Or is it something else?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjdg4ce",
"gjdp7un",
"gjdk87l",
"gjdme4v"
],
"text": [
"That's a big one, yes. Compare an economy where there is a middle class to one where there's only very rich people, and very poor people. How will the economy continue to perform when the poor masses have little to spend to fuel it, and the few rich even though they can buy a lot probably won't do so, purchasing only what they need in terms of necessities and perhaps hoarding money instead of spending?",
"Economies ultimately exist to provide people quality of life. It's a way to 1) get you goods and services you need and want and 2) incentive you to create more \"value.\" It's unrealistic for everyone to be rich. There isn't enough materials for everybody to fly private and live in mansions. Obviously being poor sucks, so with a middle class you have a relatively high standard of living for a lot of people. It's a way of saying you've got people in places where they can provide value and also they are getting enough resources to live a very high quality life. There's also arguments that when a lot of people have decent income, they buy tons of goods and services which creates demand for labor which then creates more opportunity for people to have a decent income. A handful of super rich can't spend nearly as much as a mass of middle class. The problem is defining middle class is tricky. Is it a hard standard of set as a range between two incomes? Or is it assets? Does it fluctuate based on the overall income of the population? In the US, does the standard change state to state? Is a retiree with no income living on $2 million middle class? Is a doctor making $600k a year with no savings middle class, and if not, are they richer or poorer than the first person? I make this point just to show that when a term is challenging to define, people can spin it for political aims.",
"The strength of an economy comes from mass products. While rich people might buy all sorts of things, there are not enough rich people for everyone to be employed making/selling luxury goods. However, the things a middle-class family can afford, you can sell hundreds of millions of those things.",
"It's hugely important. We see this a great deal in developing nations, with China and India being classic examples. Both countries used to be made up of a few massively wealthy families and almost all the population being poor. The rapidly expanding new middle class are buying their stuff, houses, cars, and this creates enormous development of towns and roads. The hardest thing now is maintaining careful oversight of this bubble."
],
"score": [
17,
9,
7,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky1fqx
|
Why do we lose interest on something?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjdgwll",
"gjdiqvf"
],
"text": [
"Our brains like experiencing something new quite regularly. If we consume the same thing (food, song, or socialize with the same people) for long enough, our brains go \"hmm, this is boring, let's do what we can to try something else.\" Then we move on to the next song/dish/group of people.",
"We look for patterns/repetition in everything, but creativity/imagination demands new ideas/experience based on our framework (who we our at our core) as a person. So, you might like that new song/food, but once you can predict every aspect, beginning to end, there's no point in hearing/tasting it as often & our mind wanders for different experience. I'm sure there's someone who can neurologically break down why, but i figured I'd give it a shot"
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky1kre
|
Why do we get dark circles under our eyes when we’re tired?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gje4olo"
],
"text": [
"The skin under our eyes is thin, and covers a lot of muscles and blood vessels, the blackness is the reflect of these blood vessels, they increse in size when you're tired, that's why it gets darker"
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky2o8x
|
How does the lottery know unclaimed prizes exist?
|
Does the lottery track every ticket number sold and compare it against the drawing? Otherwise how would they know someone has won?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjdny2e"
],
"text": [
"yes, they do exactly that. everyone that sells tickets uses the same point of sale terminal that logs the numbers and timestamps of everything sold."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky2tmj
|
If money is not backed by something tangible, like gold, what gives it any value?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjdoyuo",
"gjdoun8",
"gjdowly",
"gjdp11f",
"gjdp2t8",
"gjdqf98",
"gjdpgjt"
],
"text": [
"The shared belief that other people will accept it. I mean, gold coins or bars don't have any \"real\" value either (yes, yes, electrical conductor, etc. but that's not why it functioned as a currency). Currencies work because other people believe they're good for something.",
"Function. If someone will take scraps of paper printed by the government and give me the things that I want, then that money works for me.",
"It is valuable because it is universally recognized as a store of value. You give me a Dollar, and I'll give you something of equivalent value. Because I know I can later trade that Dollar for stuff same as you did.",
"Nothing. A fiat currency only has value because we all believe it does. Sometimes people stop believing, see Venezuela.",
"A big source of value is the fact that there are times that the government will demand payment (e.g. taxes) and will only accept that payment in the form of the money it issues. Failure to do this can result in armed men arriving you deprive you of rights and/or property, both things that you presumably value.",
"This is a question that very serious people asked back in the 1880's when we first started thinking about a more paper-based currency. Every country had always been on some kind of currency backed by scarce, hard-to-forge resources. Often it was gold, but also silver, and tons of other things. At the time, lots of smart people (including presidents) were absolutely certain that just having currency without being able to change to gold would instantly cause massive problems. For example, [1900, or the last president]( URL_0 ), where we switch off of gold, resulting in massive riots and anarchy and the dissolution of America. So we made money that \"could\" be converted into gold on demand. But then people noticed that hardly anyone actually did the conversion. Eventually we stopped allowing the conversion, and conservatives thought the country would go to rack and ruin. That was about 100 years ago, and we've done pretty well :-)",
"Faith. Basically, fiat currency is being multiplied by banks. They take the money you deposit and they mark it as being in your account but at the same time, they take the money you gave them (assuming you won't need it all at one time) and starting lending/investing it. Why is a stock valuable? why is bitcoin valuable? Basically because people believe it is. Take the US dollar for example. It is seen as a stable currency, one that other countries trust (often times in favor of their own fiat currency). As long as everyone wants more US dollars (demand) it contains value because you wouldn't give it away to someone who is demanding it, instead you make them buy it. If tomorrow, everyone decides Tesla stocks, or bitcoin, or the USD are no longer valuable and sells them en masse, then demand is low and supply is high, meaning you can't charge much for them and value is lost."
],
"score": [
13,
6,
6,
3,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[
"http://www.gutenberg.org/ebooks/60479"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky300x
|
Why does vinegar clean up literally everything? (Rust, wax, epoxy resin, stuff that’s basically impossible to remove otherwise)
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjdu1sa"
],
"text": [
"Because it has acetic acid in its composition, which is usually used for cleaning because of its properties. I believe that it is the main reason."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky36xb
|
why people still wear black/blue wetsuits.
|
I hear the explanation for ANY kind of aquatic violence on humans, such as shark attacks, always being they’re mistaken for resembling the shape and color of their prey. It seems like a fcking no brainer then to have wetsuits either soft orange,red, yellow, green. Why continue wearing things that make you look like a seal.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjdrinw",
"gjdrx6k"
],
"text": [
"Looking up at the surface from below I think any color will basically look black(dark) against the sky.",
"It wouldn’t help; sharks can’t see color. URL_0"
],
"score": [
13,
11
],
"text_urls": [
[],
[
"https://www.abc.net.au/science/articles/2009/11/26/2754146.htm"
]
]
}
|
[
"url"
] |
[
"url"
] |
ky55ba
|
how comes kinesin protein can "walk"? Aren't proteins unorganic stuff able to just do simple movements based on chemical reactions?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gje3533"
],
"text": [
"Proteins are organic, they are long chains of carbon with stuff dangling off. Kinesins \"walk\" because reactions (e.g. splitting ATP to ADP + P) can change the shape of a protein. Something as simple as binding an ADP instead of an ATP can radically change the shape of a protein, so that if the \"rest state\" of the protein is ATP-bound with the \"right foot forward\", splitting that ATP to an ADP changes the protein to the next stage, \"left foot forward.\" Releasing that ADP and binding another ATP will reset to the rest state, and it will have taken one step forward. The same principle is used in the actin/myosin motor, where a myosin head \"walks\" along actin fibers to create muscle contractions."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky59y6
|
How is monetary inflation sustainable?
|
Won't everything eventually require an unreasonable amount of currency to purchase? Will we have to reset currency eventually?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gje3rdi"
],
"text": [
"Well, as time goes on, larger units become more prevalent and smaller units become less useful. The penny, once sufficient on its own to buy products, has since become more of an annoyance. Larger bills, like twenties and even hundreds, find themselves being used more frequently. We will eventually need to print larger bills, but that is a ways off."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky5e2o
|
How's Calorie Counting made?
|
I mean, how does one knows how many calories a certain food have? What method is used? (Idk if the flair should be chemistry or biology, sorry)
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gje4vkv"
],
"text": [
"Our bodies very slowly oxidize molecules to get energy from them. Another way to say oxidize is to say burn. What we do to test calories is we dehydrate the food super well, removing all the water we can, and then set it on fire. By measuring how much big the fire is and how long it burns we can calculate how much energy the fire made. We divide that amount of energy by a constant to give us calories. Basically, life burning calories is literally burning lots of small fires at a chemical level. We can just burn a big one and measure it."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky5nk4
|
What happens in your brain when you pass out?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gje6wil"
],
"text": [
"In simplest terms, there is a nerve that runs through your body that when stimulated causes vessels to dilate. If overstimulated they dilate too much and your blood settles to the lower part of your body. When this happens your brain does not get the blood (nutrition and oxygen) that it needs. Your brain is very smart and realizes that it's not getting what it needs and makes you pass out so you'll lay down and in doing so, give the brain the blood it needs. When the brain gets what it needs you wake up."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky6exa
|
How does cash back work?
|
idk if this has been asked before but I really don’t get it
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gjebqjb"
],
"text": [
"In the UK, cashback is just an opportunity to take money out of your account without using a cash machine. If you go into a store and pay with your card for £10 worth of stuff, they might ask if you want cash back. If you say, \"yes, £5 please\" then they charge your card £15 and give you your products and £5 in cash. Just saves time. Not sure if it's the same in other places though."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky6hjh
|
How do we know that historically accurate things are.. historically accurate?
|
Let's go back to the 1600's. Stuff happened. How do we know this stuff happened - the way people dressed, ate, acted? Is it a collective of surviving evidence gathered from the time? How do we know that written statements from the time period weren't bullshit? Do we just agree that we can form a general picture of what happened in the past from the surviving evidence? (1600s used as an example, this applies to general history. I assume things get more questionable the further you go back) Thank you for indulging a historically-challenged idiot who's had a few whiskeys.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjebpvg",
"gjec2pv",
"gjebl7f",
"gjev9nw",
"gjes6ac"
],
"text": [
"As with any time in history, you rely on corroborating evidence. If you only find one thing indicating something, you're completely correct that it could be fabricated, exaggerated, or in some way false. But if you have many pieces of evidence from various sources that all state the same thing, it raises the confidence level in regards to accuracy. Best if you can find evidence from independent sources which may not share the same cultural biases. Sometimes you can't find this kind of supporting evidence, in which case you might make note of it in case something new shows up to support it. You also have to account for bias since, as the saying goes, history is written by the victors. It can be challenging, as often times the stories of the losing side are destroyed or forgotten, and thus historians may never have a full, complete picture of some events.",
"We have lots of written records of things happening in the 1600s that we know are utterly bullshit and just made up for various reasons. This is a lot of what historical researchers have to dig through to find out what is real and what is made up or misinterpreted. It is very important to historians to not only look at what was written or what artifacts remains from something but also look at their history in the mean time. A lot of historical texts are just made up for one reason or another so you need to look at who the authors are, what their sources are and what their motives are. Even if you have multiple sources saying the same thing it might be that they are actually just quoting the same unreliable source. And it is a similar issue with artifacts. People made forgeries and repaired or embellished real artifacts. This is why historical research takes so much time and effort. You can not just go to the library and read through a few old book and start writing your own book based on these. You need to actually do lots of research for every single piece of fact to try to find independent sources for them. One of the reasons why it is easier to study historical warfare then other aspects of life is because you often have records of the wars from both sides so you can compare them. When you get first hand records of people at a battle saying they saw the lord and savior himself come down from the skies to rain lighting bolt upon the enemy you might not want to take this quite so literally but rather look at how the enemy depict the battle scene.",
"We don't really. Most of what we know comes from stories passed down, paintings, artifacts etc. We try to peice it together the best we can, but we can't be 100%. Its not just recent history either. Dinosaurs probably didn't look like we think they looked. We just guessed. Modern theory is that the TRex had feathers, very crazy. Its fun to think what they will think about us 1000 years from now. Maybe all the Golden arches will make them think we worshipped a clown who loved hamburgers.",
"Read War and Peace by Tolstoy. It’s basically a treatise on how history can never be truly accurate because it is written by the victors, doesn’t take into account different perspectives (i.e., a peasant vs. a lord), and a lot of other reasons. There is also a story in there somewhere.",
"History is something that's always evolving because we don't have a complete picture of everything that happened in history and as we learn more, what we know changes. Take for example, the city of Troy and the story of the Trojan War. The ancient Greeks and Romans believed they were real, but history back then wasn't very rigorous and the focus was more on the story. When history became a more rigorous field, a lack of evidence meant that for a while Troy and the Trojan War were thought by most historians to be entirely mythical. However, in the late 1800s, a the ruins of an ancient city was discovered and was close enough to the descriptions of the ancient stories that it's believed to be Troy so now the stories are believed to have been loosely based on actual events."
],
"score": [
32,
9,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky6zlm
|
How and why do book copyrights expire?
|
I've been seeing a lot of posts and articles recently about the copyright for books such as *The Great Gatsby* expiring and being released into the public domain. Does this mean that anyone can just change up the original plot a bit and then republish it?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjefvm2"
],
"text": [
"Yes. They can also make their own sequels, adapt it into a movie or video game, publish copies of it, do poetry about it, anything they want and don't have to pay anyone. The idea is that after a certain amount of time, generally 70 years after the author dies for US law, the work becomes public domain and anyone can use it without needing to get permission or paying anything. Disney and other companies got the US to extend our copyright laws to try and make it harder for that to happen, so for the past few years we haven't been getting many new items in the public domain, but now that will be a regular thing every year."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky7dtm
|
are violas, cellos, and double basses just BIG violins?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjeijpe"
],
"text": [
"Violins and violas are pretty much the same in different sizes. The cello has the endpin in addition, but is otherwise (to my knowledge) pretty much the same, of course bigger again. Historically, all of them evolved from the \"viola da braccio\" (\"arm viola\", as opposed to the \"leg viola\", viola da gamba), so it would be equally correct to think of violins as \"big violas\"). The double bass is actually a little different from the three - it has another form (mainly the \"falling shoulders\" - should become clear when you look at a picture from the front) and the chords aren't tuned in fifths, but instead in fourths (E1 - A1 - D - G)), some modern instruments with an additional chord below (C) such that they can play an octave lower than the celli over the whole range."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky7gsa
|
Why do humans not make their own Vitamin B12?
|
I read that Vitamin B12 is mostly found in meat. Do the other animals make their own B12? If not, where do they get it from and why do humans need supplements if eating like herbivores (or is that just a modern problem?)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjeglug"
],
"text": [
"B12 is found in relatively high concentrations in the bacteria that live in soil. Humans used to get enough B12 from eating vegetables but that went out the window when we started obsessively washing produce(which you almost have to do with industrial crops). I don't know too much on the subject, but I assume animals get their b12 from soil as well"
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky7jlu
|
how do some gels give that cooling effect on your skin?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gjek30b"
],
"text": [
"They use menthol, which like capsaicin for warmth, trigger the nerve receptors that detect cold. Your skin may feel cold, but it really isn't. Other water based creams may cool your skin, because when water evaporizes it takes a lot of energy from it's surroundings to go from liquid into the gaseous state. So to heat it self up it cools you down."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky89pk
|
How do prospectors/miners figure out where to dig for ores, especially really deep mines?
|
Seriously how the fuck do they know where the good stuff is going to be, especially back before ground penetrating radar?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gjeloku",
"gjemcry",
"gjewplw",
"gjf3cjz"
],
"text": [
"They don't *know*, but there are ways to guess and check. Even a century ago, we had a pretty good idea of what types of rock were found in what areas of the world. And certain types of rock are, for various reasons, associated with particular mineral deposits. For example, if you're looking for diamonds - which are made very deep in the Earth - you'll need [a very deep vent]( URL_1 ) that can pull up material from near the mantle. If you're looking for [ores that hang out with iron]( URL_0 ), you probably shouldn't look in rocks that don't *have* any iron in them. And so on.",
"Looking at the overall geology of a site, they can get some idea of the type of rock that makes it up. Taking core samples is another way — it gives an idea of the layers of material that are underneath, that sort of thing. Prospecting for oil can be done with sound, too — using explosives to create a sound wave, the vibrations can be analyzed to see what’s underground. But also — hitting really rich deposits of material was difficult, and in some cases still is today.",
"So let's look at an old gold-rush prospector example: \"You find some gold flecks in a river\" let's find out where the gold came from! One way to do that is to basically divide the area around the river into a grid and take samples of rock and soil from different areas of that grid. Wash/filter/sift your sample and look for gold flecks - did you find LOTS of gold? Look at how much gold you find in each bit of the grid, and use that to basically play \"Warmer/Colder\" until you find the source of hard gold deposits. & #x200B; Now imagine instead of just taking \"I'm a prospector who found gold flecks in a river\" you scale that up to a mining company that is familiar with general characteristics of the minerals known to certain regions. Instead of \"Gold Flecks in the River\" your start might become \"Exposed Cliff Face with mineral composition known to be found in the vicinity of the stuff you're looking for\" (Different types of ore form under different geological conditions -- if you're looking for \"Rare Old Hot Rocks\" you want to start looking where you know there are \"Old Hot Rocks\"). Instead of just \"Dig and sift\" they can drill and take core samples and see what kind of rock they get but a lot of the general premise is the same.",
"Often times those deep mines would be a case of \"follow the vein\". A \"vein\" is like a streak or sheet of one type of rock that cuts through another type of rock. For example, gold is often found in quartz veins. These are visible from the surface, and the mine shaft would be dug to follow its path. Once the vein ended in a particular direction the digging would stop."
],
"score": [
30,
24,
11,
4
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Goldschmidt_classification#Siderophile_elements",
"https://en.wikipedia.org/wiki/Volcanic_pipe#Kimberlite_pipes"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky9ewi
|
How do Animals that live in the Ocean know where they are going?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjf55sj",
"gjev005"
],
"text": [
"I can only speak for sea turtles, but they have a distinct three stages of navigation: 1. When they hatch, they follow the reflection of the moon on ocean water. This is why they tell you not to have lights on at the beach during turtle hatching season. They basically just aim towards the light. 2. When they first get in the water, they go against the waves. So they can feel the direction that the water is traveling in waves, and they constantly try to swim against that. 3. Once they’re into deeper water, they follow the magnetic fields of the Earth. They have specialized senses that can tell the direction of magnetic fields so they can tell the direction they’re traveling",
"Different currents used for migration might move at different speeds or feel different temperatures (remember the East Australian Current in Finding Nemo? 😁). I believe some land animals (not positive about sea animals though) can sense magnetic fields, so it’s like they have a built in compass. Others might be able to see different parts of the light spectrum (think a black light or night vision goggles). Just because humans can’t tell the blue water apart doesn’t mean they can’t?"
],
"score": [
7,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ky9o4w
|
How do criminal profilers know a subject has a stutter?
|
Been binging a lot of true crime podcasts, and it always amazes me how FBI Profilers can determine a suspect has a stutter by the nature of their crimes. How??
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjezv3u",
"gjf1aeb"
],
"text": [
"They don't. They make an inference that a person has a particular trait that has contributed to their exclusion from society, e.g., a stutter, a second head, etc. Or they will make a claim based on very inconclusive other traits that have been observed with greater frequency in criminal populations (e.g., firesetting, torturing animals, etc.). We hear crime reports based on the successful guesses, but the cases where 'profiling' makes incorrect guesses don't make for very good TV. Take a read of Ressler's \"Sexual Homicide\" and similar work out of the Behavioural Science Unit of the FBI, and you'll be looking at some of the worst pseudoscience ever published. The British approaches from people like David Canter are a much better example of the scientific application of psychology to criminal investigation.",
"Check out Dangerous Minds by Malcolm Gladwell. Profiling is BS. But boys who stutter have confidence issues later in life . So if you think a serial killer is not confident, it is possibly because he had a stutter. Edit: Minds. Mike is okay ."
],
"score": [
11,
9
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky9r8j
|
Is DNA in human sperm altered throughout adulthood?
|
If a male were to impregnate a woman at say, age 18 vs. 36, after considerable *wear and tear* on the body, is there a higher chance that the male is now passing possibly "damaged" DNA onto his offspring? How much can diet, exercise, drugs/alcohol, etc. affect DNA of offspring?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjexdeu"
],
"text": [
"The testicles produce sperm constantly, every day, every minute. And those vary in their capability. The healthy ones are good swimmers, the damaged sperms are bad swimmers. For natural impregnation sperms have to reach the egg through swimming there (after sex). And the distance is significant. So just through this distance, healthier sperm cells are more likely to arrive first at the egg and get to connect with it than sperm with damaged DNA. Nevertheless does it seem, that age, caffeine, warmth and probably a whole lot of other substances decrease the numbers of \"healthy\" sperm cells and increase the number of damaged sperm cells. Newer research suggest apparently, that not only the genetic damages are responsibel for some health issues of the offspring, but also something called \"epigenetic\" information. Latter is information about the DNA (more or less, I'm not an expert). This information is used for example to determine, where the DNA came from. Almost every cell in your body can distinguish between the halves of your DNA. The one half you got from your mother and the other half you got from the mother."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ky9wsc
|
how do scientists know the Earth's core is liquid if no one has ever seen it or extracted a sample?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gjewmp7",
"gjewo49",
"gjgx97n"
],
"text": [
"Earthquakes generate different kinds of seismic waves that behave differently when passing through different materials. Notable, one of the types of waves (S waves) don't pass through liquids. This creates a kind of \"shadow\" that tells us that part of the core is liquid. But the behavior of the other kind of waves (P waves) also tells us that there is something solid inside that liquid. Here is a picture for reference: [ URL_0 ]( URL_1 )",
"Most of what we know about Earth’s core comes from earthquakes. When an earthquake happens, it sends sound waves through the ground so powerful that sensitive instruments can detect them from all the way on the other side of the planet. Just like how light refracts and lenses while going through materials of different densities, the core of the Earth works like a lens bending the sound waves that pass through it in a very specific way. By measuring these sound waves, it’s possible to work out a lot of very precise detail about Earth’s core including what state of matter it is.",
"In the old days, 30 or 40 years ago, it was thought that the core was liquid. Now it’s believed that there is a solid core surrounded by liquid. I lost a bet over this with my son."
],
"score": [
44,
13,
3
],
"text_urls": [
[
"https://akm-img-a-in.tosshub.com/indiatoday/images/story/201602/seismic-waves-650\\_042715041742.jpg",
"https://akm-img-a-in.tosshub.com/indiatoday/images/story/201602/seismic-waves-650_042715041742.jpg"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kyazho
|
Why does a 50” 1080p TV look great, but a large print 2 megapixel photo looks like crap?
|
A 1080p image is slightly larger than 2 megapixels, and video at that resolution looks great, even on a 50” inch screen (roughly 44 ppi or pixels per inch). When it comes to printing photos, though, a 2 megapixel image can’t be printed much larger than 4x5 before it starts to look crappy (lower than 300 dpi or dots per inch). Even if you pause a 1080p movie and stand up close to the screen, it still looks pretty damn good. So what gives?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjf3k6d",
"gjf50e1"
],
"text": [
"1) A moving image that is refreshed at fast rate vs a static one. 2) Viewing distance. 3) If the 2M image is composed with care and exposed correctly and later you apply post processing, it will also look good, especially if you view it from distance. 4) Many billboards were shot with only medium format analog cameras (6x6). Viewed from 100’ distance they look good.",
"Printers are weird about resolution. They tend to print at very very high dots per inch. Such that if the dots were pixels a high resolution image would only be a few inches across. But they also aren't really pixels and don't come out as a real square grid of perfect picture elements and have a bunch of limitations that makes them an effective lower resolution. So your image ends up being both upscaled in some ways and also lower resolution in other ways and ends up looking bad. Really nice printers are less bad about this, a photo printed in a book from a 2mp image will look fine, because they actually have nice printers and know rules to keep images in standards the printer won't go crazy on ruining."
],
"score": [
12,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kyb046
|
Why do Tsunamis pull back the water when they start getting closer to land?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gjfdeid",
"gjf3xuf"
],
"text": [
"A sea wave is an upward and downward movement of water. To illustrate, go pinch the middle of your bedsheet and pull it upward. Watch what happens to the edge of the sheet. Edit: As suggested by u/lightupsketchers the key thing I left out is that water molecules pull on their neighboring molecules, which makes them act like a sheet, for the purposes of this model.",
"It’s exactly like every other wave - if you watch one at the beach you’ll notice water pulling back just before a new wave crashes. It’s just a smaller scale than a tsunami. The Tsunami is massive and it’s energy needs water from somewhere. That somewhere is the shallow water in front of the wave, which then comes back in a nasty way when the wave reaches shore."
],
"score": [
48,
9
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kybawd
|
Why have we not run out of ip addresses?
|
With the massive growth in internet devices, shouldn't we have used up all possible ipv4 numbers?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gjf4kcy",
"gjf4z44",
"gjf7ki4",
"gjg0js4"
],
"text": [
"We did, sort of. We have way more devices than ipv4 addresses, but a lot of them are using the same address and hiding behind a local network. For most broadband setups, your entire WiFi network is only consuming one public IP and it's using a whole bunch of local IPs behind your router. This bought us some time. Ipv6 was invented to make sure this \"never\" happens again, it has a far (far far far) larger number of addresses.",
"We have, essentially. There are five regional internet registries (RIRs) and in the last ten years they have all run out of new IPv4 addresses, most recently in November 2019 when the RIR for Europe, the Middle East, and Central Asia used up their last one. Some individual ISPs still have unused addresses, and both ISPs and RIRs can recycle old addresses that are no longer being used.",
"1. We switched to ipv6 - this increased the number of ips from 2^32 to 2^128. A lot of infrastructure and network infrastructure switched immediately freeing up space for in ipv4 for other stuff. 2. We cheated. Routers became small devices to \"lie\" to the Internet and keep track of which device is making which connection while showing only one address to the web. Internal addresses start with 192.168 or 172.16.0.0-172.31. or 10. This is Network Address translation. 3. We Subnet more closely with CIDR and Variable length subnet masks to save addresses; we use network addresses as assignable in certain environments, Probably other cheating.",
"A technique called NAT helped out with that. It's basically used everywhere both for business and in homes. Fiber connections aside, it's also a contributing reason why we call the box at home 'router' and not 'modem' anymore (even though modem functionality may be built in for cable connections). NAT works like telephone switchboard. Let's say you call customer service at a major company, there could be 200 people answering the phone but there's not 200 numbers listed under 'Contact us'. There is one number that you call and then it's split up internally. If they call you back, you typically only see their shared number, the one you called, displayed on your phone, not the individual number for the individual operator. Internally, if they need to call a colleague or manager they can use short numbers (\"extensions\") like 0046 that doesn't work outside their telephone system. Connected devices work similar in a NAT:ed network. They get unique internal addresses and they can share \"real\" public IPv4 addresses for external connections. The router keeps track that device ABC asked for URL_0 , so all cat pictures from that connection should go back to that device. There are three ranges for internal use, with the vast majority of devices for private use is configured to use addresses looking like 192.168.0.x. So it's likely that a number of people in any Reddit thread may actually have the same private IP address, but everyone in their own closed context \"behind\" their public address."
],
"score": [
121,
15,
13,
3
],
"text_urls": [
[],
[],
[],
[
"www.reddit.com"
]
]
}
|
[
"url"
] |
[
"url"
] |
kybeav
|
why are we addicted to drama?
|
Especially on social media or reality shows despite knowing that it's mostly fake and exaggerated? Why is it SO hard to stop binging drama? Even celebrities start drama when they start getting irrelevant to get back on the grid cuz they know ppl will eat anything up.....just curious
|
Psychology
|
explainlikeimfive
|
{
"a_id": [
"gjf6u3h",
"gjf8fvj"
],
"text": [
"Probably because we as humans enjoy hearing about other people’s suffering to distract us from our own.",
"There are most likely many mechanisms at play. However one particular one I suspect is derived from human social structures. We form tribes and are tribal by default and we are very sensitive to the hierarchy structure of the tribe. Knowing what is going on in the tribe is a very important asset to negotiate your place in that structure without relying on violence. Therefore we have most likely developed an attraction to gossip as this gave people with such a tendency a social advantage."
],
"score": [
9,
8
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kybyrk
|
What makes a scar last?
|
Why is it that I have scars that have lasted since childhood that were caused by totally insignificant injuries, yet when I get really bad injuries now, the scars fade super fast? I thought it was safe to assume that worse injury = worse scar
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gjf8rck",
"gjff470"
],
"text": [
"Children typically have a faster rate of collagen production because they are younger and still growing. Their cells multiply faster, so the scars come out thicker and stay longer. Adults don’t typically have this “advantage”, as their cells have since slowed down, making scars less fortified.",
"I'll add to the other factors, the way a wound heals has a lot to do with the scar it leaves. On both of my index fingers, along the inner side, I have nearly identical hatchet wounds that were made about a week apart and, at the time each was afflicted, were nearly identical in severity. But the first wound I didn't have proper tending supplies i.e. antiseptic creme, bandaid, etc. I had to makeshift a bandage using paper towel and rubber bands. A day or two later I got the proper supplies. So the time the second wound occurred I had all the supplies ready and could tend it properly from the start. The difference in scar is significant."
],
"score": [
23,
13
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
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