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lt6teh
|
When a tooth falls out from its location, then how does our body produce new tooth to replace it and how does our body produce it without giving us any sensation of pain?
|
I am really weak in bio so sorry if this question is really simple
|
Biology
|
explainlikeimfive
|
{
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"text": [
"You are born with all the teeth you will ever have. When a baby tooth falls out its because its being pushed out by another tooth, then the other tooth, the adult tooth, simply slides out the the hole thats already there. And there can be some pain with teeth that are breaking through the gums. Baby's go through teething which is uncomfortable for them. And children have molars grow in that break through the gums and that can make your mouth sore. Check out this picture of a babies skull. It's really quite fascinating. URL_0",
"It doesn't... Teeth don't grow back: you get two set of them and that's it. Adult teeth grow inside the jaw bone and are pushed out by the bone growing under them when they are ready. [Here is an x-ray where you can easily see adult teeth inside the jaw]( URL_0 )"
],
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7,
4
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"https://www.google.com/imgres?imgurl=https%3A%2F%2Fpbs.twimg.com%2Fmedia%2FCINaaLTWsAA7jqg.png&imgrefurl=https%3A%2F%2Ftwitter.com%2Fdrlindseyfitz%2Fstatus%2F613433381137842176&docid=QWVhBBRS4QvUOM&tbnid=BmB_qm9col21yM&vet=1&source=sh%2Fx%2Fim"
],
[
"https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fcdn.24.co.za%2Ffiles%2FCms%2FGeneral%2Fd%2F1951%2F41027ff472614972885eba13d9db8176.png&f=1&nofb=1"
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[
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[
"url"
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lt7gxe
|
How do things get lost in the postal system? Do those parcels ever get found?
|
Other
|
explainlikeimfive
|
{
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"gow5ani",
"gowe1ch",
"gow065y",
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"text": [
"Some of the lost stuff just falls into hidden spots. I heard once about a bunch of old mail that was found behind a postal machine when it was moved away from the wall. One disgruntled postie was found to have two big sacks of mail at their home when they were being investigated for one or another crime. Labels can fall or be knocked off of packages. There's all sorts of crap that can happen. When lost mail is found, it goes back into delivery. Truly lost stuff, e.g. no label left on it, probably goes into the lost and found or the option that u/someone5793 describes.",
"If you are in the United States the USPS only has 1 facility for lost items, and it is the Mail Recovery Center in Atlanta. You can Google for \"USPS Mail Recovery Center\" for more info, which will also help answer your question. This is the only place that sells undeliverable USPS mail. From the website for the USPS Inspector General: > Ever wonder where parcels go if the labels fall off? Or what happens if a package is undeliverable? > > The U.S. Postal Service’s Mail Recovery Center (MRC) serves as the “lost and found” center for the Postal Service, receiving items determined to be undeliverable for a number of reasons. In Fiscal Year (FY) 2019, the MRC received 67 million items from post offices and other facilities around the country. While that’s a large number, it’s a small fraction of a percent of the 142 billion mailpieces the Postal Service delivered that same year. > > Once items are received, the MRC determines what to do with them. If possible, they are returned to the sender, and if not, they are inventoried, held until claimed, and eventually sold, or otherwise disposed of.",
"Technically no. They all go to one spot (you’ll have to look up where your town puts them). You can go and buy lost packages and I think they are priced by weight. You could end up with hundreds of dollars of stuff that you paid little to nothing for.",
"This reminds me of that episode of the rugrats where tommy gets lost in the conveyor belts at the post office"
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|
lt7rh0
|
- if women have so little testosterone, how do female bodybuilders and athletes get so much muscle?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"Muscle development isn't strictly based on hormones. Testosterone does make building muscle easier to do, but working the muscles continuously is going to cause them to bulk up. As others have pointed out, there are also PEDs that can be taken to artificially boost testosterone levels to build up quicker and to a greater degree than simply working out alone will do.",
"A lot of ridiculously overmuscled women are on steroids, so they have extra testosterone. There are also women with naturally high testosterone levels who can put muscle on better than normal.",
"It’s pretty offensive that all the other comments so far mention PEDs. Professional athletes aren’t allowed to take them, so obviously PEDs are not responsible for their muscle tone. An abundance of testosterone makes it easier to build muscle, but is not a requirement. It’s like power steering: You can turn the car without it, but it’ll be harder. Women simply have to do more work to make gains. Also, testosterone is not the only hormone involved in muscle production and maintenance. Both men and women rely on growth hormone and insulin-like growth factor 1 (IGF-1), and estrogen plays an important role for women."
],
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8,
6
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[
"url"
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[
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|
lt7vpa
|
Why can’t people who’ve gone through treatments with growth hormones donate blood?
|
Biology
|
explainlikeimfive
|
{
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"gow0zf0"
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"text": [
"It's mostly historical at this point, now that synthetic human growth hormone is a thing. If you had synthetic growth hormone there's no medical issue. However, before we figured out synthetic HGH, the only source was cadavers (dead bodies)...we'd extract the hormone from the pituitary glands of dead people. This greatly increased the risk of transmitting disease from the cadaver to the recipient, and someone getting HGH from an external source could be exposed to hundreds or thousands of cadaver sources. Rather than expect everyone to know the exact source of every HGH shot they ever got, it's a lot simpler to just say \"If you had HGH, don't donate.\" Source: my brother was on synthetic HGH for years"
],
"score": [
5
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[
"url"
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[
"url"
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|
lt80o2
|
Why do some drugs take weeks to have an effect when others work straight away?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gow28ru"
],
"text": [
"All drugs ‘work’ straight away in that they are metabolized by your body. Some drugs like painkillers you can feel the effect right away because they work by blocking specific reactions from occurring that cause you to feel pain. However, other drugs like anti-depressants are different. There is an immediate effect, of increased serotonin reuptake, for example, but more time is needed for your body to adjust to the increase in serotonin, by having more serotonin receptors and so on. Think of it as your mind rewiring itself to adapt to the medication and increase in serotonin. In general, it all comes down to the concept of homeostasis. If you’re treating an acute issue, you can usually feel the effects immediately, but if you’re changing someone’s state of being, it takes longer."
],
"score": [
7
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[
"url"
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[
"url"
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|
lt85s3
|
What Edward Snowden did?
|
Technology
|
explainlikeimfive
|
{
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"gowgmay"
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"text": [
"He told the world that the American government was breaking its own laws by spying on everyone without any sort of legal process.",
"So Edward Snowden worked at the NSA. Which means he was computer spy. While working there he saw the NSA was spying on the American public. All of them. All the time. He believed this was wrong because if the police or security services want to spy on a person, they must prove to a judge that they have a reasonable suspicion the person is committed a crime. The NSA was spying on everyone, just in case they might be planning a crime. Edward Snowden believed the public should have the right to decide whether they agreed with this or not. He told his boss how he felt and his concerns were ignored. So he started to collect as many documents as he could and devised a plan to leak them to the public. He contacted several journalist secretly, who he believed were trustworthy enough to decide which documents the public should know about and which should stay secret. Then he flew to Hong Kong and arranged to meet them. He didn't tell his girlfriend or his family. As he didn't want them to be guilty of breaking the law. He met the journalists and passed them all the documents and explained what they were. They quickly began writing articles about some of the programs. The world started to put two and two together and Edward Snowden went into hiding fearing he might be arrested by Chinese security services or possibly worse by US spies. About this time wikileaks' Julian Assange and a small team started trying help Snowden. They sent one of their most trusted legal advisors to meet him and began booking multiple airline tickets for him all to different places in order to confuse the security services as to when he would be travelling and which flight he would be boarding. He boarded a flight to somewhere in South America, however he had to stop in Russia to board a connecting flight. By the time he landed in Russia the US state department had revoked his passport. Consequently he was unable to enter Russia, and unable to board any flight out. He was stuck in the transit area of the airport for 39 days while he applied for asylum in dozens of countries. The US government was pretty annoyed at this point as many of the stories journalists were releasing made them look very bad. So they started calling every country they thought he might apply for asylum in and told them they had damn sure better not grant him asylum. Which they agreed to, as you don't want to piss off the US government.... Unless you are Vladimir Putin. He loves to piss off the US government. Consequently Edward Snowden was granted asylum in Russia. Sadly what then happened was that the public he risked so much for, pretty much didn't a fuck. The programs he told journalists about were ruled to be illegal, and useless. They hadn't prevented any major terror attacks and the release of them hadn't cost any American lives. But people started to believe that \"if I've done nothing wrong I have nothing to hide.\" and none of the NSA senior staff or Government officials even resigned, let alone got charged for the hugely illegal surveillance programs they were secretly running and deliberately hiding. In fact a couple of them got promoted. So what did Snowden do wrong. Nothing in my opinion."
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|
lt89fu
|
why isn't forest predators, like tigers and lions, fur green?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"Mammals simply do not have the genes to produce green pigments. All mammal fur and hair is pigmented with some combination of only two kinds of melanin: * eumelanin makes brown and black fur * pheomelanin makes yellow and orange fur * White fur has no melanin. Those are the only colors of fur that any mammal is able to produce, period.",
"Unlike humans, the animals that tigers normally prey are red/green colourblind, which means they cannot distinguish between reds and greens. To their eyes, the tiger is perfectly well camouflaged.",
"Lions don’t live in forests; most lions live in grasslands or sparse tree scrub areas and being dusty matches their surroundings. Tigers hunt at night/dusk/dawn and the stripes are effective at breaking down the silhouette enough to allow them to successfully hunt. That being said, no mammal produces green pigment, and clearly it was sufficiently successful to be colored the way they are to survive that the evolution didn’t need to bother with complex structural coloration that could potentially yield green.",
"Well lions most certainly are not forest predators, they live in dry grasslands where they camouflage rather well. In actual fact, lion and tiger camouflage works because most mammals have only two types of color-sensing cone cells in their eyes and are thus red-green colorblind. This is called dichromacy, as opposed to humans and related primates which are trichromatic and thus can distinguish green from orange. So while a human might clearly see an orange tiger amongst green foliage, to a deer or an antelope or another tasty prey animal it all looks like the same shade of greenish-yellow. [Here's an article where you can see the comparison.]( URL_0 ) This is also why deer hunters can wear blaze orange without the deer seeing them a mile off. If humans were a staple of a tiger's diet, there would be evolutionary pressures to camouflage with a different color.",
"There are some good answers here such as how mammals can't produce green, or how their prey is colorblind. Another reason is that even to a human, this type of camouflage still works. There's a lot of browns and oranges in the jungle such as sunlight coming through branches as well as the bark of trees. If you are close enough to see through the camouflage, it's probably too late for you anyways. As far as evolution goes, good enough is good enough",
"As explained below, and in this recently [reposted TIL]( URL_0 ), it is primarily due to most if not all of their preys vision being dichromatic, meaning that they (the prey) are blind to the colors of red and green. This means that to the prey, the orange of that tiger and the green of the grass are basically the same color."
],
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42,
41,
19,
11,
6,
3
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[],
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[
"https://www.iflscience.com/plants-and-animals/we-now-know-why-tigers-bright-orange-color-is-actually-excellent-camouflage/"
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[],
[
"https://www.reddit.com/r/todayilearned/comments/lrgero/til_tigers_orangeblack_skin_color_works_very_well/"
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[
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[
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|
lt8ggb
|
Why are prostitutes looked down on in our society?
|
Economics
|
explainlikeimfive
|
{
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"gow6dl3",
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"text": [
"Because women having agency over their bodies is something that patriarchal society hates. Plus, it’s really hard to tax them.",
"Because one of the very influential groups involved in forming this country was the Puritans who believed that any sex not in a marriage, and for the purpose of procreation, was evil. And that has never been fully expunged from our social subconscious."
],
"score": [
7,
6
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[
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|
lt8tl0
|
What is a stop order, and a limit order, and a stop-limit order?
|
I kind of vaguely get the concept of (buy|sell) when stock reaches a certain price, but that's the extent of my knowledge.
|
Economics
|
explainlikeimfive
|
{
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"text": [
"A limit order specifies that the order only will be executed if it is possible to obtain your price or better. A stop order is almost the opposite, triggering to become a market order if a set price (or less favorable) is reached."
],
"score": [
4
],
"text_urls": [
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|
[
"url"
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[
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lt8vc9
|
I work on a farm and it gets quite dusty, and most days I feel like I have sunburn on my face (red sore skin) even though it’s not been sunny? Why is this
|
Biology
|
explainlikeimfive
|
{
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"gowh7kp",
"gow8rh5"
],
"text": [
"Could be wind burn. Or it could actually still be sunburn. Do you have really fair skin? UV light can still penetrate clouds, especially if you’re out all day.",
"You can get a sunburn even if it’s not particularly sunny. If you can see outside, light is still passing through the clouds, so the UV light that causes sunburn is as well",
"This is a medical question so hard to say without digging into it but it could be something as simple as heat rash which occurs when the sweat pours on your face get clogged, or it could be from some kind of chemical interaction from contact with agrochemicals. I would try washing your face multiple times throughout a non sunny day. If the problem occurs then its probably not heat rash. This post does not constitue financial advice and I am not a doctor"
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|
lt9dgp
|
Educational designations. Why are some degree lumped together under one designation (such as with BS) while others have their own designation (such as MBA)? What factors determine the "official" way to list one's designations?
|
Other
|
explainlikeimfive
|
{
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"text": [
"The high-level designation is basically what order: B - Bachelors, comes after high school. M - Masters, comes after bachelor's. PhD - Doctorate, comes after Masters Then you break down the \"how long\": B.Arts/Science is usually 4 years. B.Eng or BS.Eng is usually 4 years (but with more credits) or 5 Masters are all over the map, but M.Fin is usually 1, MBA is usually 2, M.Eng is 1 or 2 depending on the program. MD is many years. PhD is basically \"forever, or until your dissertation is done. After that, it's \"what skill are you actually learning. MDs can be medical or dental, MBAs can be Ops, Strategy, Marketing, Finance. BA, BS, MA, MS, M.Eng, PhD can be basically anything the university has a department for."
],
"score": [
3
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[
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|
lt9may
|
Why do pilots always say we’ll be able to “make up time in the air”?
|
Whenever a plane is a little late taking off, the pilot will say that we will be able to make up time in the air. What does that mean, and if we’re able to make the plane go faster to make up time, why can’t they make the flight shorter to begin with?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Its less fuel efficient to fly faster. If everything is going ok they will fly at a more efficient speed to save money. However if the plane is late to take off it may be worth it to go a little faster so that the next flight isn't also late.",
"As others have said, flying faster (either with a tailwind or burning extra fuel to keep the schedule), but there is also some flexibility with the Air Traffic Control (ATC). A pilot can request a direct take-off to potentially jump ahead of other flights that are closer to their on-time departure. ATC can provide a slightly faster overall route (especially if weather or other traffic conditions permit). And, on the other end, the flight might be able to land directly, land on a runway nearer to the terminal in a direction that is more favorable to get to the gate faster. (An airplane landing has to slow down and pull off the runway to a taxiway, then taxi to the terminal. The direction the airplane lands can allow the plane to be able to spend less time taxiing if it can leave the runway closer to the gate the flight is headed to. Also, large airports have multiple runways, and one will always be closer, meaning less time taxiing. Plus, a runway further away will probably have to cross another runway, which can add another minute of delay if the flight has to wait for another plane to take off/land from the other runway.) And, finally, many flight schedules have extra time added due to the possibility of weather, traffic conditions, or other factors that can cause delays. Airlines want to have fewer \"regularly running late\" flights, so they will work to build in extra time where needed to reduce the change that any of those factors will cause enough of a delay to make them look bad. (It is more complicated than that, but this is a simple explanation.) So, a flight from Colorado Springs to Denver (total distance of 65 miles, \\~35 minutes flight time) may be scheduled for a full hour, since snow at either airport or traffic in Denver might add an average of another 20 minutes. In fact, if you book that flight, you will notice that flight times vary depending on time of day, and the flight into Denver (the busier airport) is given an extra 10+ minutes, and the return flight is listed as shorter, due to airport and route conditions."
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ltad0n
|
Why do some animals tilt their heads when they are confused or trying to figure something out?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"By tilting the head, you can adjust how sound waves travel over the ear and possibly get a better understanding of the sound stimulus. But animals do this when they see something unusual too, even if there are no sound waves associated with the object in question.",
"First, you need to know a little about how ears work. Once you know that part, the answer to your question will be easier to see. Destin, of Smarter Every Day, covered the audio basis for why dogs tilt their heads: [ URL_0 ]( URL_0 ) It is well worth a watch. (Start at the beginning if you want to see what caused him to ask the question about dogs tilting their heads and how humans figure out which direction sound comes from.) I will try to give a summary, but Destin's video is really the best way to understand it. Ears have a special shape. That shape allows the ear to tell which direction a sound is coming from. Two ears together give an even better idea of direction, since each ear can get an idea of direction, and the brain can put those two together, along with how one ear is (probably) hearing the sound louder than the other. However, that only works on a horizontal plane. (In other words, in front, behind, to the left or right, or somewhere in between.) Above and below are not quite as easy, for a few reasons. (For a poor analogy, think about how much harder it can be to figure out how far up or down something is, compared to how far in front of you it is.) From a biology point of view, most items of interest will be at the same level as you, so this works most of the time. Animals still need a way to figure out direction (and distance) in the above/below direction as well, so they figured out a hack. Instead of needing a third ear on the top of their heads, they just tilt their heads sideways. While tilted, they lose some of the forward/back/left/right direction sensing, but up/down is better. Then, they straighten their head, listen for a moment, then tilt their head the other way. This is how they determine the direction of an unknown sound. They also use this trick when it is a sound they can hear but cannot identify. So, if you make a noise at your dog, they will listen for a moment, then start tilting their head. In that case, they can (probably) tell the noise is coming from you, but they are using the head tilt to either confirm it is coming from you (since you do not normally make that noise) or they are trying to get a better \"listen\" to the noise. They do this naturally when they hear something that causes them aural confusion. Animals also do this when they are confused about non-audio things as well. This is due to certain behaviors being tied to inputs, even when they do not match perfectly. An unknown thing could be a danger, so it is better to react in whichever way makes sense. So, the head tilt is the brain trying to figure out the confusing thing by moving the head/ears, even when that is not necessarily going to help the confusion. People -- who are a type of animal as well -- do this too sometimes. You will sometimes notice a person, if they are trying to see/hear something, or think about something confusing, you will see a small head tilt. Much less than you would see with a dog, but it is there (at least in some cases)."
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|
ltauwr
|
Where do they get newborn babies for birth scenes in movies and TV shows?
|
Babies in scenes [like th]( URL_0 )[is]( URL_0 ) are definitely real and definitely only a few weeks old. Where do studios find them? Is it safe for the babies? And how much do they get paid?
|
Other
|
explainlikeimfive
|
{
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"text": [
"In the UK at least, there's agencies out there that parents can sign up to. I do extras/supporting artist/background work, on my profile I can say I'm pregnant & when its due & any other children I have if I was happy for them to be considered for anything. Every so often there will be a call out on the agency's Facebook page for newborns or asking there's anyone or does anyone know anyone who's due around \"X\" date. It's quite a big community so there's often quite a few responses, multiple agencies will be looking as well. They'll have a parent and a chaperone on set with the baby at all times, only time it is away from them is when its being filmed & even then the chaperone is there keeping an eye on things. Only people who handle the baby is parent, chaperone, costume, maybe make up?? And actors. - I also work in costume, had to swaddle a baby for a Tudor drama! As for pay, no idea! There would be some sort of guideline to how much they get paid and as it's a baby, they would on be allowed on set for maximum a few hours a day.",
"I believe they hire them as they would any other actor. Whether it’s safe or not is up to the parent to decide if it’s okay for their child. But I’m sure any reputable studio keeps in mind the child protection laws for the entertainment industry.There’s a [Vox]( URL_0 ) video explaining it.",
"Most of the time (these days anyway) they hire babies that were born premature. That way, they still look like a newborn (ish) but aren't as fragile.",
"They cast them just like any other parts using agencies. So a parent will sign up with an agency saying 'i have a baby due on X date, or an infant that was born on y date', and we would like film work, and when they want to carry a baby in a movie or show the agency matches the people they know would be interested in taking their child along to be filmed with the production. There are a while host of roles that go along with this to ensure the children are safe and cared for, that conditions are good and they are only on set for limited periods of work, which is why studios cheat as much as possible. So when you have a shot of a baby being carried for example, if it is swaddled in a blanket, where you won't see it's face or any movement, why use an actual child? Swap it out for a doll, as when all you see in the movie is a glimpse of the top of its head that can look realistic and fool audiences. Even a lot of pretty clear shots can be done with realistic looking dolls - basically unless you actually need to see a face or limb moving in the shot, a realistic doll can be a suitable stand in on film. Because there are a lot of rules to ensure the babies are safe and well cared for, they will also do things like looking for premature babies so that a slightly older child can take the past of a younger one, and looking for twins (or babies that look close enough in general) so that they can swap out the babies between scenes as babies are only allowed on set for relatively short periods."
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ltb37c
|
How do body shapes change via evolution?
|
I understand that this is a *long* process over the course of generations of individuals. I understand how adaptations occur through natural selection- a bigger individual may be better suited to surviving an encounter with a prey animal, or a smaller individual may get by on less food, etc. But how do body plans change? I can't figure out how we get from species A to species B. Is it all random mutation? One extra vertebrate in the neck and in half a million years you have a Sauropod?
|
Biology
|
explainlikeimfive
|
{
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],
"text": [
"Yes, it's all just random mutation and time. If having a *slightly* longer neck means that a creature is more likely to live longer, then they're more likely to survive and pass the \"slightly longer neck\" mutation to their offspring. Many many generations of the \"slightly longer neck\" version later, they now have a much longer neck (as long as neck length happened to aid their survival for whole time).",
"Mutations don't happen like, longer arms, or bigger bicep. They happen at protein levels where something small controls something else and so on. When a mutation affects something that controls melanin production, then you get changes in pigment in animal skin. Small changes like these acrue over time, based on which benefits the organism, and eventually they change so much they speciate and become a \"new\" organism. It's important to remember it takes millions of years, which is why it seems so unfathomable how an animal goes from A to B."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltbb9k
|
Do microorganisms die at 100 °C immediately or do they gradually die as the water temperature gets to a boiling point?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goww656"
],
"text": [
"Different organisms have different tolerances to heat. Some organisms can survive beyond 100C. > Methanopyrus kandleri is a heat- and salt-loving species of Archaea that makes its home on the chimney walls of smokers. It harvests energy from hydrogen gas and releases methane, a process known as methanogenesis. It's this process that gives the microbe its name: Methanopyrus translates to “methane fire.” Methanopyrus kandleri has been isolated from hydrothermal sediments at Kolbeinsey Ridge off the coast of Iceland and the Guaymas Basin in the Gulf of California. In the laboratory its cells can even divide at 122°C, the highest temperature known to be compatible with microbial growth, though it grows best at 98°C. URL_0"
],
"score": [
3
],
"text_urls": [
[
"https://ocean.si.edu/ecosystems/deep-sea/microbes-keep-hydrothermal-vents-pumping"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltbpw7
|
Why does noise block higher pitches of music but you can still hear the lower bass notes or bass-y percussion like big drums and stuff?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gowz345"
],
"text": [
"Lower pitches are \"Stronger\" than higher pitches, allowing them to penetrate through sound or physical barriers more than higher pitches can. Lower pitches travel further through space than higher pitches, as well (if both have the same amplitude/force behind them)."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltbtcb
|
Why do magnets get demagnetised? How long does it take for that to happen?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goxnxtj",
"gox2n8y"
],
"text": [
"Magnets depend on the orientation of the atoms in a material. They will pretty much tend to stay that way. But there are things that will de-magentize them. It's not simply a matter of a certain amount of time. Ways to de-magnetize: (a) Heat the magnet above its \"Curie temperature\". That allows the atoms to have enough thermal energy to move into random orientations. (b) Wait a long time and let regular room temperature thermal energy do the same thing as (a). (c) Expose the magnet to a magnetic field that is in a different direction than the one it already has. (d) Whack the magnet with something hard or against something hard, repeatedly. (Really, this works.) (e) A combination of the above.",
"magnets are made by running an electric current through them when they are still hot. this aligns the atoms so that the positive is always pointing one direction and the negative is pointing the other. after that the magnet is commonly exposed to chaotic magnetic forces that exist in our daily lives. over time those forces will realign the atoms in various directions. the more mixed up the directions are the less magnetized the magnet is. the harder the metal the longer it takes to demagnetize them."
],
"score": [
13,
8
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltbuyv
|
how do UV shielding windows work?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gox563s"
],
"text": [
"Normal glass (used in windows and such) is not transparent to UV light. It mostly absorbs the wavelength,(it reflects some), the same way say asphalt absorbs almost all wavelength or your blue T-shirt absorbing all wavelength but blue. Absorbed photons transfer energy to the material (usually electrons) and turns into heat."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltby7h
|
Why is it more common across all age groups to have eyesight problems than hearing problems?
|
Why is it more common across all age groups to have eyesight problems than hearing problems? Its only common to have hearing problems in older people.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gox4w1s",
"goxfkw8"
],
"text": [
"Most common vision problems today are nearsightedness or myopia. This is a result of the eyeballs growing too long (front to back) which puts the image out of focus on the retina. Because eye growth happen when you are young and growing, myopia shows up in school age children and persists from there on. Myopia is common because eye growth is controlled by light on the retina...intense light tells the eye the image is properly focused and it's the right length. But if you grow up and spend a lot of time indoors, your eyes don't get enough intense light to control growth properly and myopia happens. So people in modern industrial societies very commonly have myopia. There's no equivalent process that regularly throws off hearing for everyone (although if everyone listens to their earbuds turned up too high, maybe there would be)",
"So, others have talked about problems with eyesight. I feel I should give some balance and talk about hearing (since it's my job!). Hearing research generally lags behind visual science because its a bit easier to see how the eye works than the ear. This means it's not always so easy to pick up on hearing problems. With eyesight, people might have problems with certain distances, which we can't fix with glasses. Or they might have issues with certain colour, which we can't fix. We ignore the problems we can't fix, and use glasses for those we can. But glasses are a passive solution. They don't add any distortions, so they work well. Problems we can fix are usually about the shape of the eye, so can be fixed with physical things. Hearing is a different matter. Traditionally, \"hearing impairment\" means you need sounds to be louder to be able to detect them. Hearing aids can help with this. They can be used to boost certain frequencies of sounds. But this isn't (usually) a physical issue. It's often caused by \"hair cells\" in the ear becoming damaged from use, which is why it tends to affect older people. The way to fix this is with hearing aids. However, since these are active devices, the introduce problems. They buzz and hiss, and people can hear this. So, if you had a very slight problem with your vision, glasses would help. But if you had a slight problem with hearing, a hearing aid would probably just annoy you. Plus, there can be a lot of other types of hearing loss, and how we categorise these is an open question and a hot topic. So, visual problems are often physical, hearing problems can be neurological (to do with nerves), but other hearing problems can be physiological. For example, someone might be good at *detecting* sounds with an audiogram. But they might not be good at interpreting sounds in a noisy environment like a pub. Hearing aids can't really do much to help (at least at the moment) as they'd need to be able to separate the sound you *wanted* to listen to from the background, and boost that and that only. So basically it seems like it's more common because you see more people with glasses. This is partly because it's harder to fix hearing issues. It's also partly because hearing aids are less noticeable than glasses. Also, PSA: protect your hearing! Feel free to wear earplugs at gigs and loud parties! :)"
],
"score": [
7,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltc1jb
|
Why are we only addicted to things that are bad for us, not saying it’s exclusive, but more often than not it’s bad for us.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gox2ikl",
"gox5esb"
],
"text": [
"An addiction is defined as something which is detrimental to our lives. There are plenty of things we will seek desperately which are not only healthy but necessary. Food, shelter, and love. Those are not addictions until our lust for them *becomes* detrimental. When we cannot abstain from sex, when we cannot abstain from eating.",
"Basically you get addicted to things that are usually not “bad for you” but by becoming an addiction it is then bad because it’s to the extreme. The other user said it much better than I did haha"
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltd1yc
|
why does bread soaked in water taste so bad?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goy1myw"
],
"text": [
"The texture of soggy bread could be part of the reason, since it is quite discomforting. Another reason could be that bread loses some of its sweetness when it is dunked in water. When we chew bread, we break down starch into sugar using enzymes, and we're able to perceive the bread as sweet. If the bread is dunked in water, then it is harder for the enzymes to get to that bread, and so we cannot taste the bread. Combined with the sogginess, tasteless bread will taste very horrible. I hope this helps! (Dipping bread in soup is a different matter, as you have the soup for the taste. The sogginess of the soup bread matters less than the sogginess of a sandwich bread.)"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltdckl
|
Roman ingenuity seems to disappear after the fall of the Empire.
|
eli5: With all of the advancements made by the Roman Empire, why after the fall does it appear that society as a whole regressed in so many ways?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goxbads",
"goxntza"
],
"text": [
"The period immediately after the fall of Rome used to be called the \"Dark Ages\" because historians didn't really know much about it. But as research progresses, so does our picture of what really happened. Granted there was some disruption in technological advances because the dominant force in the region was no longer in charge. But that doesn't mean everyone immediately reverted to stick huts in the woods. URL_0 The Byzantines, also known as the \"Eastern Roman Empire\" continued for centuries after the fall of Rome itself and the western stretches.",
"Don't forget that \"Roman ingenuity\" consisted largely of \"conquered a lot of land and call that 'Roman'\". When Rome \"fell\" it lost control over those lands and thus lost access to those minds from other parts of the world. A lot of that ingenuity came from Greece, which fell under the Eastern part of the Roman Empire."
],
"score": [
8,
4
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/List_of_Byzantine_inventions"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltdok3
|
How do companies decide which fonts to use for their software?
|
Do they base it off of popularity polls or something like simplicity? You never see elaborate fonts used which makes sense because consumers likely have difficulty reading them (if they're used for generic text as opposed to headers or something of the like).
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goxd6bn"
],
"text": [
"A combination of \"the skill and expertise of their designer\", and \"arbitrarily, based on an executive's whim\"."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lte4rn
|
How does the "second wind" works?
|
I was wondering how exactly does this "second wind" works? Does your body gets a random boost of energy or what?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goxho3d",
"goxfuj2"
],
"text": [
"Somewhere deep inside your brain the rocky theme starts playing. Your goal becomes your only focus as tunnel vision takes over. The montage begins. The chaos emeralds circle your body. You're now super sonic and have the ability to run an extra bit.",
"Everyone's body is different so what brings about the \"second wind\" may be different from person to person. Possibilities include: - You're close to the finish line so the visualization of you finishing is a mental incentive for you to push because you can relax once you finish - Your body slowly breaks down as you push yourself to the finish line. The second wind happens once you cross a threshold where you feel pain in enough places that it doesn't bother you anymore. (From the thought that your pain tolerance increases when experiencing pain in multiple places in your body) - Your body generates endorphins when working your muscles. The endorphins excite the mind past pain from muscle exhaustion. Source... ish: URL_0"
],
"score": [
6,
6
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Second_wind"
]
]
}
|
[
"url"
] |
[
"url"
] |
lteee8
|
Why is it that some foods that aid in digestion (ex. Brussels sprouts) can cause constipation if eaten in excess?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goy0271"
],
"text": [
"These types of food have a lot of fiber, and fiber traps water, which keeps the bowels soft. It is easier to pass soft bowels through our intestines, and so having more fiber in the diet usually helps to prevent constipation. On the flip side, having too much fiber makes the bowels travel more slowly through our intestinal tracts, and that actually leads to more water being absorbed and creates drier bowels as well. This is why too much fiber could lead to constipation. Essentially, there has to be a balance between \"keeping water in the bowels\" vs \"slowing down the bowels enough that too much water is absorbed anyways!\""
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lteiu0
|
Why do camels walk differently than other four-legged animals?
|
I was watching a wicked cute video of a baby camel and a baby cow playing, and I realized that the camel had a weird gait. The camel would walk by lifting its left front leg and left back leg at the same time, then both right legs. It didn’t alternate like the cow did. Like... it was waddling but with 4 legs rather than 2. Like the YMCA Village People costumes people wear... but with 4 legs...
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goxr0me"
],
"text": [
"I don't know specifically why camels adapted that type of gait, but with some research it is knowing as [pacing]( URL_0 ) and horses can naturally share that same gait. However, pacing is actually faster than other types of gaits...in horses specifically it is used for harness racing (the kind of racing where the rider is in a cart attached to the horse rather than in a saddle) *because* it is faster. Due to the movement of the horse moving the rider side-to-side rapidly it's an uncomfortable saddle ride though, which is why it's only used for some types of racing. Regardless, it appears it's possibly one of the faster ways for four-legged animals to move, so perhaps camels developed that type of gait so they have faster sprinting speeds when necessary?"
],
"score": [
7
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Horse_gait#Pace"
]
]
}
|
[
"url"
] |
[
"url"
] |
lteubp
|
What actually happens to the dust and dirt that we inhale into our lungs everyday?
|
How does it get ever expelled if it sticks to the mucus walls?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goxngr8"
],
"text": [
"Little hair-like structures called cilia constantly sweep the mucus lining upwards out of the initial respiratory tract (bronchus). Any dirt or dust that gets caught in the mucus in this step will eventually get swept out and enter the stomach. Smoking damages these cilia which causes more particles to remain in the lungs. Dirt and dust that get stuck deeper in your lungs will remain there forever. Your immune system will form a fiber scar over it to isolate it from your body."
],
"score": [
25
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltfduy
|
How does anxiety - something mental - affect you physically?
|
Sometimes when I’m anxious I get palpitations, chest pains, complete loss of appetite and diarrhea etc. How is anxiety linked to these physical feelings?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goxsruq",
"goxrx3t"
],
"text": [
"Your brain controls your body. Anxiety is in your brain. So, anxiety can affect your body. The actual mechanism is through the the stress response. Psychological stress (perception of stress) is directly related to a physical process in your body that is the physical stress response. This response is generally an increase in heart rate, release of adrenaline, decrease in digestion, etc. All these changes in your body are caused by signals from the brain, including the release of \"stress\" hormones. Why does this system exist? Because, if you were suddenly attacked by a bear, your body needs to get ready to run or fight. No use wasting energy digesting food if you're about to die. Maximize blood flow, get the muscles ready. This is all GOOD stuff for us. It helps you perform at peak capacity. \"Stress\" doesn't always mean \"bad.\" The problem? We weren't meant to be in that state *forever*. Our bodies can't handle *chronic stress*. It wears us out; so that's why your stomach can get upset and you feel tired. Also our mental perception of stress is, now-a-days, not about survival issues for many of us. It's about mundane stuff. Like did I forget to mail that form? But our brains don't always know the difference. Your physical response is still the stress response, and it still wears you out.",
"It's because of the chemicals that flood your body with anxiety. We're all just a big waking chemical soup. Your anxiety is just that and doesn't know if at any moment you might need to fight for your life but floods your system with chemicals that facilitate some of that. Over time your body starts getting pissed by so much anxiety chemical stimulation it causes inflammation and physical symptoms can become chronic. Which is ironically anxiety inducting lol. This is why you must find ways to help yourself and/or get to the doctor.....because someone put too much pepper in the chemical soup that is our brain and you need a proper chef to know what to add or take away to balance it all again."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltfl8c
|
Modern filming techniques vs 90s (?)
|
This question requires some set up...Im not a film nerd in any sense So im not sure what the proper terminology is for all these things...Iv recently come across the 24 hour version of Pharrell Williams's - Happy and the type of filming it used felt oddly nostalgic I tried googling some stuff but never got any good results. So the closest thing I can use to describe it was it feels like the camera is equally on the environment and the person being filmed it seems like whatever this is it was used in a lot 90s movies/tv too.Its as opposed to modern movies which seem to focus on the person in the frame rather then the entire area like its more zoomed in.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goydim0"
],
"text": [
"I am going to believe you are describing one aspect of a production shot on film versus modern digital recording. Film cameras were the shit, still great, but like wine corks versus screw tops eventually practicality and cost and availability and ease-of-use wins out and digital and screw tops become the norm. But for a while shot on film was the thing and with it came certain conventional uses, wide frame shots to show how clear and focused and true to life the scene could be and cameras at eye level for most shots with conversations or thinking etc. Digital becoming accepted then the norm freed up productions from large expensive studio cameras and all the conventional use cases. But they also couldn’t replicate the ‘big’ feel of film, so they pivoted to more tight shots, close-ups, etc to play to the strengths of the new equipment. Very soon it led to a decidedly different type of production with more cameras available, hand held, easily mountable, many different configurations and all sorts of practical effects available that more than made up for the limitations of the newer medium."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltfle0
|
Conservative Politics
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goxvgda",
"goxturh"
],
"text": [
"Democrats and republicans are political parties, the kindest interpretation of them is that they are meant to gather people who have similar view points together so that they can act in a coordinated way. Conservatism is a view point on the way the world operates, they tend to be republicans. The crux of their viewpoint is that traditions, religion, social norms, families and rules that exist do so for a good reason, and they are what makes the world a good place. They should be protected from change and when they are changed they should be changed back. Whereas progressivism would be the opposite and they tend to be democrats. We can make the world a better place by changing traditions, religion, social norms, families and rules. Those things exist for a reason that is either invalid now or was always corrupt. They need to push change to make the world a good place. Conservatism and progressiveism are ideas though, in practice the political parties that supposedly represent them, answer to a much different incentive structure.",
"Government is smaller and stays out of the personal lives of citizens. Citizens in turn rely less on the government and more on self/family/community, hence strong family values and work ethic."
],
"score": [
9,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltfq8w
|
How do blankets with feathers in them keep stuff warm?
|
I think its weird and had that question for a little bit or maybe I am just tired.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goxxku5"
],
"text": [
"Air is a really good insulator, it does not transmit heat well, especially if it can't easily move around. So anything that can trap and hold air is good at stopping heat from leaving you and keeping you warm. Feathers, especially the \"down\" feathers that cold-weather birds have under their outer water resistant layer, are \\*really\\* good at trapping air. Blankets with feathers inside can trap a lot of air with a comparatively small amount of stuff. Fleece, wool, foam, stuffing, etc. all work the same way...trap a bunch of air and use it for insulation."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltfrx8
|
In the movies, when characters smoke, do actors actually have to smoke?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goxvyv2"
],
"text": [
"Generally yes as actually smoking a cigarette is pretty hard to fake with CGI. Granted they usually aren't smoking tobacco, it's a herbal cigarette which is basically some type of plant that isn't tobacco."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltfsdq
|
Why do children not react to cold like adults do???!? Example could be kids at the beach loving the freezing water on a cloudy day, whereas an adult is physically hurting in the same temp. water.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goxxluw",
"goxvhte",
"goxxoo1",
"gp0kvi1"
],
"text": [
"Children are way more active than adults, for one. More active = more heat. Two, *feeling* cold is not the same thing as *being* cold. Our sensation of warmth isn't the same thing as temperature, in other words. Best example: touch a fluffy blanket in your room. Then touch a piece of metal in your room. The metal *feels* colder, but it's literally the same temperature (room temperature). What you really *feel* is the transference of heat energy away from your body. Children may actually not feel like they are cold because compared to all the heat their activity is generating, the sensation of the heat leaving their body may feel kinda nice comparatively. But that doesn't mean their body is not actually cold (temperature-wise).",
"Ever heard of Wim Hof? Adults have learned to react how they are expected to react to the cold water. Children enjoy it as a new sensation and a novel experience. Kids stay more in the moment, until they're taught to react in a different way by well meaning adults.",
"pain tolerance change with age. If you've been conditioned for a very long to avoid most pain. The slightest changes seem extreme. Plus, children are far more adaptable to environmental swings and their perception/nervous system is still learning. So if children have no reference point of office job, couch sitting for 40 years stored in their body. They won't be so easily dislodged from their bodies true potential.",
"I think part of it is also that kids really know how to live in the moment. If they’re horsing around in cold waves, they’re not thinking about if their towel is getting sandy on the beach, if they have enough warm clothes ready for afterwards, if there are enough sandwiches ready for lunch and how cranky everyone is going to be on the way home. They’re just playing and screeching and loving it and able to ignore a lot of other external things including being cold."
],
"score": [
28,
17,
11,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltg4ww
|
How can the Texas Freeze be linked to warming in the Arctic?
|
Today I saw a news article that stated the Texas freeze was most likely linked to warming In the Arctic but I’m really confused as to how that process works
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"goy0bg2",
"goy31cd",
"goy14w8",
"goyailo"
],
"text": [
"The whole planet is warming not just the arctic. This causes weather patterns to become more erratic and things that wouldn't usually, like Texas getting snow, happen more frequently.",
"The temperature changes make the jet stream angry and destabilize it. Now it's whipping around the earth like a top about to fall over",
"Expanding on the previous comment - specifically arctic melting releases cold water (ice melt) into the ocean above and outside of regular volumes and cycles. This additional cold water disrupts warm currents while also increasing cold air which then also disrupts traditional wind cycles. one phenomenon linked directly to this is late onset of summer, effectively shifting seasons. Another is an incease in wind-based phenomenon like cyclones and tornados. Another directly linked to this is more severe monsoons due to increased ambient moisture, which in winter can also lead to unseasonal snow.",
"There is a weather phenomenon called the polar vortex. It’s usually a tightly spinning mass of super cold air, that looks kind of like a hurricane. Now due to climate change and warming in the Arctic, this polar vortex weakens and instead of a tight spiral it loosens up, spreads out and wisps dip down into areas well below the Arctic circle. These wisps of super cold air that dip down from the Arctic are what cause the super cold temps like Texas experienced"
],
"score": [
12,
11,
6,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltge1f
|
Why can a rubber band keep a lobsters claw shut but they can clamp down with so much force?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goy1957",
"goy17rj",
"goy1311"
],
"text": [
"They have very weak muscles for opening the claw. The important part that they evolved for was to crush prey. Opening the claw requires very little force so they didn't evolve strong muscles for that. Similarly, crocodiles have incredibly strong muscles for clamping down on prey, but you can hold their mouth shut with your bare hands relatively easily.",
"Try pinching your thumb and index finger together with your other thumb and index finger. Spread the inside ones as strong as you can, and pinch outside ones together as strong as you can. Your pinching fingers will be stronger and force the others together.",
"Curious to see the answer. I’ve heard the same about alligators and crocodiles, less force is needed to keep their jaws closed (in case of attack..) I think we need the physics side of Reddit lol"
],
"score": [
28,
14,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lthrpe
|
How do they make seedless watermelons
|
If there’s no seeds how do they grow more.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goyc7bm"
],
"text": [
"Seedless watermelons happen by crossbreeding two specific different strains of watermelon. The original strains still have seeds so they can reproduce on their own without crossbreeding. Note that watermelons are not the standard for seedless fruits. It's more common that other seedless fruits need to be developed by grafting, or planting cuttings or similar ways of cloning plants."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lti6kc
|
why did animals used to be so much bigger and stronger than they are now (ex. terror birds - > Seriemas or Palaeeudyptes - > penguins)?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goygv5u",
"goyt3vn",
"goys5wp"
],
"text": [
"Partially thats just not true - if you look at the past like that, youre essentially cherrypicking the most impressive creatures from hundreds of millions of years. In fact, the biggest animal to ever live is the blue whale, which is present on earth right now. Other than that, there was a quite \"recent\" extinction event - the [Quaternary Extinction]( URL_0 ) - which killed of most big animals on earth. The reason was probably mostly predation by humans in combination with climate change (end of ice age). So tldr: because we ate them all.",
"Being large is just like any other evolutionary trait. It only occurs when there's an advantage to it or at least no disadvantage to it. Being large brings a degree of safety from predators for instance. It can help you store large reserves of energy. And it's more efficient in very cold climates. It also requires large amounts of food to maintain that big body. You can't easily hide from predators or survive lean times on small amounts of food. Take contemporary blue whales for instance. They're the largest species that ever lived and they're hyper-specialized. Blue whales spend their lives migrating between warmer waters where they reproduce and frigid arctic waters where they feast during the krill blooms when tiny oceanic krill reproduce in huge numbers. The krill blooms are the only time blue whales can eat the enormous amounts of food they need. They pack on a ton of energy in the form of body fat. And then they literally cross the planet to reproduce in warmer waters. Their large bodies keep them warm in arctic waters, allow them the speed they need to cross the ocean and pack on the energy reserves because they won't eat for the entire journey. There's simply no food source big enough for a blue whale along the way. Blue whales are so specialized that if something happens to the krill blooms or something stops them from making their journeys, they'll go extinct. And so it is with other large animals in history. Dinosaurs had 165 million years to become hyper-specialized. Many dinosaurs evolved into giants that became highly dependent on their bountiful environments to find enough food. And whenever disaster struck, these specialists die out first. Island gigantism is another unusual phenomenon. Being small has many advantages, most notably it makes it easy to hide and easy to find enough food to eat. Sometimes, species end up on isolated islands where there is plenty to eat and no predators around. Over time, these isolated species sometimes evolve to be bigger than their relatives elsewhere because there's no evolutionary selection for staying small. Arctic gigantism is another phenomenon where arctic animals tend to evolve to be bigger than their relatives elsewhere because large bodies have a better volume to surface ratio. You lose body heat through your surface. A small body is nearly all surface while a big body has much more 'interior' compared to its surface. Heat efficient. That's why a lot of ice age megafauna was very big. It's just easier to survive frigid environments when you're large with lots of energy reserves to survive rough spots. And as a result, predators also grew very big and specialized in killing large prey. When the ice age ended, many of those large animals quickly evolved to be smaller as being smaller now had more advantages than being large. We think some predators simply starved into extinction because they weren't suited to hunting much smaller prey living in larger herds with more eyes, noses and ears for spotting predators. This change also gave rise to new, better-adapted predators. The ancestors of wolves and modern-day big cats arrived on the scene and proved to be much more effective hunters in this new world. And sometimes factors simply combined. When South and North America were still unconnected continents, terror birds were the only large predator in South America. North America had far more different predators and this created a high competition environment. Evolution happens much faster under these conditions as species compete. When the Central American landbridge appeared to connect North and South America, the North American predators were quick to move South and outcompeted the terror birds into extinction.",
"Oxygen concentration used to be much higher. This allowed certain organisms, particularly insects which breathe through their exoskeleton, to exist."
],
"score": [
17,
14,
3
],
"text_urls": [
[
"https://en.m.wikipedia.org/wiki/Quaternary_extinction"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltja6n
|
Why can my laptop play realistic games like Hitman 3 smoothly, but lags like hell with Minecraft shaders?
|
I use a lenovo legion 5
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goykq17",
"gozolig",
"goyva7b",
"gp12fvf"
],
"text": [
"Quality of code can differ from a shaffer made by a fan and a professionnal game studio. Also minecraft is in java so it slow from start.",
"Realistic games don't look realistic because somebody just went and made the shaders simulate reality as realistically as possible. They look realistic because somebody has spent hundreds of thousands of dollars hiring programmers to make the game *look* as good as possible on limited hardware. Generally, this translates to a lot of effects that look more impressive than they are expensive to compute, aesthetic trade-offs, compensating for engine limitations with creative design, and so on. The studios doing this have years and years of experience in figuring out what *looks* good to humans. The goal isn't to *be* realistic, it's to *seem* realistic. Somebody working on a Minecraft shader in their spare time is not going to be able to devote those amounts of resources. Most likely their shader will do something conceptually simple and do it without much fuss or optimization. The ones that look impressive are probably impressive because they're actually computing impressive amounts of data, rather than doing something less impressive and trying to make it *seem* more impressive, which is what well-optimized video games do.",
"The problem with minecraft is that it was never meant to be as big as it is today. It was some swedish dude's pet project that just exploded in popularity, so the core isn't really made with efficiency in mind. Shaders are also an add-on and something that's just added to the completed project always suffers from inefficiencies compared to an integrated solution.",
"Minecraft's engine is more cobbled (lol pun) together than Bethesda's Skyrim/Fallout engine. It's less \"functional\" and more \"held together with duct tape and chewing gum\"."
],
"score": [
32,
12,
6,
4
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltjmi6
|
how can free divers hold their breath for so long without causing brain damage?
|
If it only takes 4 minutes without oxygen to cause brain damage, how can they stay underwater for 4+ minuets and not hurt themselves.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goyqro6",
"goyup1l",
"goysbt1",
"goyu4zr"
],
"text": [
"The brain isn't without oxygen when they dive, they are relying on residual oxygen in their lungs, blood, and tissues. Consciousness is very expensive and generally a lack of oxygen will put them to sleep well before permanent brain damage occurs.",
"I free drive! Something I take advantage of is what's known as the Mammalian Dive Response, wherein when your face is immersed in water, it helps to elicit a calming affect. If you are very comfortable in the water you can basically go into a meditative like state before your dive, almost like you are sleeping. So you use much less oxygen than if you are in a normal waking state, out of the water. You can feel yourself relax and your heart rate slow down. Then you dive down, maintaining this tranquil state. A clear ocean looks so amazingly big from deep down! But make sure you know your limits and have a buddy with you who can help because it's easy to black out under water, especially if you're going for your personal best.",
"They start by oxygenating their blood. Lots of heavy or deep breathing. You can have two deposits or oxygen, your blood/body, and your lungs. The lungs are kind of like a the secondary source that feeds the primary source. If you can fill the primary source as well as the secondary source, you can last longer. Also, they use techniques to lower their heart beat, and thus/also oxygen consumption. Things like meditation. Reduced consumption coupled with increased supply equals longer times.",
"Free divers often purposefully hyperventilate before diving in order to fill their bloodsteam with as much oxygen as possible. This oxygen is then used by the brain to function. & #x200B; Free divers also tend not to use a lot of muscular movement, which would result in the use of oxygen, some have reported that their limbs feel heavy or unuseable after a long while. & #x200B; The brain, obviously, knows its not getting much oxygen, and it takes quite a bit of mental control to override the impulse to breathe, apparently. & #x200B; It's a trained skill and takes a lot of practice, I think."
],
"score": [
27,
14,
10,
4
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltjv9g
|
How does a radio receiver discriminate between different signals?
|
If there are lots of different radio signals with the same or very similar wavelengths, how is it possible for a radio to pick up just one signal?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goyrlw8"
],
"text": [
"In general, it can't. If two signals over lap, both will be received and will, generally, garble the message. While frequency - the number of oscillations of the carrier signal - is important, bandwidth - the \"width\" of the information in hertz - is important, too. For example, a radio station on 101.3 FM actually extends from 101.2 to 101.4. This spacing prevents signals from \"clipping\" into one another when adjacent channels are co-located. 101.1 doesn't go past 101.2. With two stations at the same frequency, they're usually spaced far enough apart that the power of one broadcast is significantly weak within the area of reception of the other station, thus interference is avoided. Propagation phenomena changes with different frequencies, though. AM broadcasts can travel farther at night, and some stations are required to reduce power at these times to reduce interference. Additionally, it's possible to encode transmissions to be dug out later. This is not uncommon in things like radars, where a code is embedded in the phase of the transmission and returns can be discriminated from interference despite being at the same frequency."
],
"score": [
13
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltjy7a
|
what is the gold standard and why did we get stop using it?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"goyr16q"
],
"text": [
"Well, the gold standard ties the value of money to a certain amount of gold. The government guarantees that it'll exchange one unit of your currency against a defined amount of gold. And that makes for a a problem. The amount of gold a government has at hand is not flexible, but the economy is. When your economy expands, it needs more money in circulation. There are simply more transactions, more value in goods in labour around. You need more cash to cover that. But with a fixed gold supply, you can't make that adjustment. And that throttles the expansion after a short while. You end up with wild economic swings, boom after bust after boom after bust. And that's why everyone got rid of it."
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltk0ov
|
how do plants and animals know what time of year or season it is?
|
Say how an animals coat grows and becomes thicker in the winter but molts heading into summer. Same with trees losing their leaves in the autumn and blooming in spring. If you moved with your pet to the opposite hemisphere would their internal clock adapt to the new seasons and how does it know to do this?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goypv7f",
"goytiir"
],
"text": [
"Natural biological response to environment, and circadian rhythm (the internal biological clock we all have and the reason it can be so hard to change sleep schedules and why we often get tired and wake up around the same time).",
"They don't strictly know what season it is. They detect things about the atmosphere and environment that indicate good conditions for them to do a particular thing in, and it just so happens that this correlates to \"season\" (and the spring/summer/autumn/winter cycle we base on observing plants, so it's more like plants define these seasons than detect them). Plants have a lot of ways of sensing things about the world, and they do this by measuring the locations and concentrations of certain chemicals. For example, one chemical type they produce is used to detect gravity. It moves down through the plant and accumulates at the bottom, and the plant knows that wherever this chemical accumulates must be the bottom of it (ie, towards the centre of gravity). For \"season detection\", they use light sensing chemicals. The plants measure how long it remains dark as a means of gauging the season - long dark periods indicate winter, short dark periods indicate summer. Interestingly, you can trick flowers into not blooming by interrupting the period of darkness with a period of light. Two short periods of darkness instead of one longer period will make the plant think it's summer instead of spring, and it won't bloom. Plants detect the season by measuring the progression of night lengths - if they're getting longer, it's moving out of summer and into winter, and therefore it is approaching autumn, and the opposite means spring. This detection of increasing night length triggers the autumn response in trees, where they start to lose their leaves and buckle down for the cold, although once started it seems that temperature modulates the rate at which it progresses, so a warm autumn would cause the trees to keep their leaves longer."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltkaoc
|
What's with the popcorn kernels that don't pop?
|
I have no idea what the right flair for this is, sorry.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goyrl1l",
"gp09gxu",
"gp0bydd",
"gp0edjc",
"gp285py",
"gp1pog5"
],
"text": [
"Popcorn pops because of steam pressure. The inside of the kernel contains starch and water, which are contained in a hard shell. When you heat it, the starch liquifies and the water turns to steam. When the steam pressure gets high enough, the shell explodes, the starch instantly solidifies, and the corn is popped. If the shell is broken, steam won’t build up. Bad kernel If it is too dried out, not enough pressure will build up. Bad kernal",
"In my experience usually it's because they don't get hot fast enough and so the shell just cracks letting all the steam out and they never explode. The best way to get around this is to heat the pan with the oil in it to about 350° and then put all the kernels in. This way you have very few old maids left at the bottom.",
"All the kernels have different amounts of water inside. Water heating causes popping. Some kernels don't get as much heat as others, some have less water. Too cold, or too dry, no popping.",
"Popcorn kernels that don’t pop usually pop on the second go, due to the heat they already had and are now having Source: popcorn machine owner",
"To piggyback off of this. I know you can overcook the whole bag but even when stopping the microwave at the perfect time, what keeps the early poppers from burning?",
"Popcorn kernels pop because they absorb heat energy until they reach a critical level and pop. When there are lots of unpopped kernels, most of the heat energy gets absorbed by the kernels. But when most of the kernels have popped, less energy gets taken in by kernels. The heat levels haven't gone down though, so the excess heat energy goes into the already popped kernels more and more. At a certain point the popped kernels start to burn. Since you don't want burnt popcorn, you stop the cooking before that happens."
],
"score": [
915,
44,
7,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltkedk
|
Why do we enjoy taking hot showers (40°C-45°C) but we hate taking showers that are even 1° lower than our body temperature?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goysr0r",
"goysnvx"
],
"text": [
"It varies from person to person and occasion aswell. If its really hot outside would you rather take a hot shower or a cool one? Some people never even take a hot shower, they love the cold one. In the end we as warm blooded beings like warm things more than cold.",
"I know I'm in the minority but I like cold showers, it just takes a minute to get used to them. I start with the water lukewarm and slowly lower the temperature. I started doing it because I had to (high blood pressure, at risk of fainting b/c hot showers raised it) but I've grown to love it. At first I hated it because I was missing the comfort of bed and then the isolated cold feeling got x10 worse but it was better than risking I drown taking a shower."
],
"score": [
28,
19
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltl99h
|
Is time a substance, particle, force or concept? Is it one big “block”, so the future already exists and “now” is subjective? Or is the present the only place that’s real? Are most physicists determinists?
|
I have studied a little of this in philosophy (metaphysics, epistemology and ontology) but I really need a scientist (preferably a physicist) to break down what we actually know about the world, as I regrettably have no formal education in physics and can’t work this one out on my own. Thanks :)
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goziyx0"
],
"text": [
"The prevailing answer is that time is a geometric axis. Specifically, the geometry is (usually) something called [Minkowski space]( URL_0 ), more commonly referred to as *spacetime*, and *time* just happens to be one of its four dimensions. So, time is about as much a \"substance\" or \"particle\" as the direction \"right\" is: a better analogy is that they represent the canvas on *which* things like substances and particles can exist. > Or is the present the only place that’s real? One of the most startling, but most well-tested conclusions of Einstein's theory of special relativity is that the concept of \"*the* present\" doesn't really make sense. Depending on your direction of motion, different things are happening at \"the same time\". So two observers moving past each other will disagree about what the present looks like, but they *will* agree that each other's \"present\" looks exactly like their own \"past\" in one direction, and their own \"future\" in a different direction. So the idea of there only being one *present* that exists, at any given time, is demonstrably incompatible with special relativity. We have to accept, at some level, the simultaneous existence of the past and future. > Are most physicists determinists? Depends on what you mean by 'determinist', really. If you mean \"believes the universe can be fully described by a set of equations and initial conditions\", then yes - that's practically the core assumption behind all of *physics*, and physicists tend to get extremely worried about this not being the case, something they would call an \"information loss paradox\", a \"violation of causality\", or any other number of horrible-sounding names. Of course, this is somewhat at odds with the distinction between *objective* reality and *subjective* reality, since quantum uncertainty means the two concepts can never be equal - even if the universe is *objectively* deterministic, our own subjective perception of the universe will always appear to obey random chance."
],
"score": [
14
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Minkowski_space"
]
]
}
|
[
"url"
] |
[
"url"
] |
ltld9y
|
What does Alternative music supposed to SOUND like?
|
I get that Alternative (rock) music is defined as music that differs from the mainstream rock genre. Did multiple google searches on it, but it doesn’t help. :( It’s weird that I often feel like listening to music belonging to this genre, and still not knowing how it should sound like. How am I supposed to explain to my friends what it sounds like? For example, rock generally sounds aggressive or jazz sounds sort of calm and all that.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goyx1u3",
"gp3o8jn"
],
"text": [
"What's a non-green color supposed to look like? Some would say red, others blue, a third one would say yellow. The only common defining characteristic is that it's *not* green.",
"The problem is that the definition is a pretty loose one, even moreso than the notoriously loose definitions given for most genres. Alternative rock was really coined back around the 80's as a way of describing the newer generation of bands that were appearing, specifically choosing to eschew the popular mainstream music of the time - three big glam rock bands, hair metal and stadium rock of the time. Even just the naming convention makes it hard to pin down, as that doesn't describe the genre as such, but what it is not, which is a pretty vast soundscape. As a very rough idea, distorted guitars, simpler songs with more emphasis on texture and soundscapes than technical guitar playing would be a good place to start, with something of an emphasis on a diy ethos rather than big productions. I think the genre is normally attributed to early bands like the Velvet Underground, which then started branching out. For a few fairly big examples that all broadly fall under 'alternative' - My Bloody Valentine (evolving into shoegaze - lots of instrumental music, droning walls of sound and longer, less traditional song structures), Sonic Youth (noisy dissonant guitars and harsh sounds), Soundgarden (the more grunge end of things, also evolving out of a rebellion against mainstream stadium rock), and a whole host more. Where alternative turns into grunge, shoegaze and other genres is the big question, and one where there are a wide array of opinions and no actual rules..."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltlkvc
|
How does gravity work inside other things?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goz2h60",
"goyzbgt",
"goyzksv",
"gozcrpl",
"gozsgvo",
"gp076be"
],
"text": [
"You cannot \"block\" gravity. It is not like light beams or magnetic fields. There is no such thing as a gravity shield. As long as there is mass, there is gravity.",
"Because the ball is on Earth and the mass of the Earth has a far greater impact than any mass inside the ball.",
"> Imagine a hollow metal ball, and inside that ball, there's another ball. Why does the ball inside fall to the bottom? \"Bottom\" implies that you're imagining yourself on the Earth's surface observing the balls. Why *wouldn't* the inside ball fall to the bottom? There is no shielding against gravity, roughly the same forces act on the smaller ball inside and outside the hollow ball.",
"I feel like people are missing the point of OPs question. If I understand correctly, I think he wants an ELI5 on how gravity is able to interact through a solid object. Obviously he's aware that gravity exists through solid objects, but that doesn't explain why gravity is a force that is able to work through objects.",
"Matter is energy. Energy affects space. Space is not *nothing*. It is as real to energy/matter as a canvas is to a painting. Matter and energy move through space. The effect they put into space is purely additive. While you can have positive and negative electrical charge, you only have positive impacts of gravity on space. As an object moves into curved space - gravity - it can only curve it more. Just like adding paint to a canvas can change the underlying shape of the canvas.",
"Stop thinking about the balls as objects so much as joined together atoms. The same goes for the earth, it just has a LOT of atoms. Gravity is the attraction of every particle of matter in the universe to every other particle with a force proportional to the product of their masses and inversely proportional to the square of the distance between them. The atoms in the inner ball are still attracted to the atoms in the earth, and indeed to the atoms in the outer ball, and the other atoms in the inner ball"
],
"score": [
11,
8,
5,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltm1q0
|
Why do some places (on the same latitude) get more average sunlight per year?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"goz4cqd",
"goz4pzh"
],
"text": [
"Proximity to coastal regions, altitude, humidity, cities, and vegetation all in some way have an affect on the amount of sunlight in certain places",
"My number one bet would be the difference in precipitation, i.e. clouds and rain. If it's raining 300 days a year, you are bound to get less average sunlight per year than the inland desert region at the same latitude."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltm8q0
|
Is the myth that you can't fold any paper more than 8 times true?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goz6ic7",
"goz8heg"
],
"text": [
"Yes by hand it's impossible unless you have a sheet the size of a football field. The reason is the thickness wich stacks on top of itself.",
"Maybe not exactly 8, but close to it, depending on paper thickness. Reason is that every time you fold the paper, you double its height. So by the time you're folding the 8th time, you're trying to fold a pile 128 sheets high. Standard printer paper is about 1 cm thick for 128 sheets; bible paper is about ¼ cm thick."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltnhtc
|
How hard is it to hotwire a car?
|
Like when you turn the key in a car, it completes a circuit right? How hard is it to just take the wire connected to the switch and touch them together?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gozq9ps",
"gozvl34",
"gozteur",
"gozwiw5"
],
"text": [
"Newer cars are basically impossible . Older cars such as a 1996 Honda Accord for example you can hop in and have it going in 45 seconds .",
"Older cars are as easy as you describe. You just need to provide power to the ignition circuit and then the starter circuit. In order to do this fast though you need some knowledge of the car so that you know which wires to short circuit. Some cars do somewhat protect the wiring loom from the ignition key making it harder to find the correct wires as well. However to combat this people started to install anti-theft systems in their cars. First it was third party systems but then these became incorporated in the cars design and are now pretty much standard. In addition to a normal key there is now electronics in the key which communicate with the car over radio to identify itself. So the electronics of the car will not allow you to start the car without the correct key in place and may even sound an alarm if you try. So it is no longer enough to just short circuit a few wires together but you need to trick the computer into thinking you have the correct key. This is still fairly easy but it means that car thiefs have to learn some basic electronics skills and some programming in order to make the tools required to hotwire modern cars. And it is expected that car manufacturers will soon start to incorporate some actual security measures like electronic signatures in these keys making it much harder to fool the computers.",
"As stated, old cars it was relatively easy. Gain access to the wiring off the ignition cylinder and complete the circuit, easy-peazy. New cars run near field authentication protocols or imbedded chips in the keys that need to match encryption in the ECU. So unless you can overcome that… there’s no hot wiring in that cars future.",
"It was pretty easy long ago or in older vehicles. Connect the ignition circuit, the one that completes the circuit for the coil/battery/alternator, and then connect the starter circuit that feeds power to the starter motor that initiates the system to those wires and it would start and run. [Three wires]( URL_0 ). Today's vehicles are much more complex and hot wiring one involves bypassing and/or feeding power to a lot more systems, some that are computer controlled and need an electronic signal from a computer chip in the circuit to work. Starting these involves completing a lot more than just the 'run' and 'start' circuits. Extremely difficult in most cases."
],
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16,
5,
4,
3
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[],
[],
[],
[
"https://i0.wp.com/i.kinja-img.com/gawker-media/image/upload/s--pEKnRGXX--/c_fit,fl_progressive,q_80,w_636/18n268n6mpbljjpg.jpg"
]
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}
|
[
"url"
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[
"url"
] |
ltnjnj
|
What is a magnet? Why there are only a few metals that are attracted to magnets?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goztc18",
"gp0urna",
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"text": [
"Magnets are objects that produce a magnetic field. The reason why only a few metals are magnetic is because they have a structure that more easily lines up electrons and create a magnetic field. The more electrons there are lined up, the stronger the magnetic field they produce.",
"When atoms form molecules they sometimes form spots that are positively or negatively charged and when you have a thing that can line up these spots and keep them lined up you end up with a magnet. The combined electric charges form a magnetic field, an area where those charges have influence. Now, when some metals come in contact with a magnetic field the like charges are repelled and the opposite charges are attracted and because magnetic fields are stronger when closer the net result is a pull. We call this ferromagnetism because ferro- means iron and iron is the first metal we saw do this.",
"This is the best ELI5 that I could came up with, it's not the full explanation and it's not 100% accurate but should give you an idea of how things work. First of all magnetism in materials happens because of electrons, their spinning motion around the atom's nucleus generates tiny magnetic forces. Now you can have a material in which all atoms are pretty much ordered so most electrons spin in the same direction and the magnetic forces add up to form a large magnet, or they can be a mess and all the magnetic forces cancel each other out. The materials that are attracted to magnets fall somewhat in between these two categories: their atoms are a bit messy but if you put a natural magnet near them they can somehow find an order and became magnets themselves."
],
"score": [
10,
5,
3
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"text_urls": [
[],
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|
[
"url"
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[
"url"
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|
lto9s2
|
How can crabs, shrimp etc. live in deep sea when we barley have machinery that can handle it?
|
I’m sorry in advance for poor format and english, I recently peaked an interest in the deep sea, and learnt how there are shrimp and crabs that are lower in depth than what we can send machinery, which is made of metal, and if i stand on a shrimp it crushes, but they can live at a depth where the pressure is 3000* my weight.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp0yrf3",
"gp0hza5"
],
"text": [
"Air, like all gases, is *compressible*. This means that pressure affects their volume. Most non-gases, including what machines and crabs and shrimps are made of, do not have this property. So any creature or machine (like a submarine) that is a mixture of solids and gases has a really hard time dealing with pressure change - the gas bubble wants to expand/contract, the rest of the animal does not. This causes gas sacs and membranes and other vulnerable material to rupture or get crushed in horrific ways, an effect known as [barotrauma]( URL_0 ). You can try getting around this by maintaining a low-pressure bubble inside a high-pressure region, but this requires very strong walls to resist the inwards pressure and redirect it into the structural frame. That's hard, but by no means impossible - multiple humans have gone down to the deepest parts of the ocean inside such low-pressure bubbles (bathyspheres and submarines). Another way to try getting around it is by trying to increase the pressure of the gas inside your body, but since gas is compressible, higher pressure air also has a higher *concentration* of molecules. So as you effectively end up adding more and more air into your lungs, you also end up increasing the concentration of everything in your bloodstream. Our bodies and metabolic systems are pretty complicated, and having an excess of even inert gas like nitrogen or helium in your bloodstream is generally a bad idea. So in general, you'd also need to gradually change the *composition* of the air you're breathing, to keep things like the oxygen content unchanged, and at some point we just run out of ideas for what gases to add - even helium is toxic at high enough pressures (below 1000 m). Conversely, sending a robot down to those depths is actually really easy - it doesn't have the same issue at all, so it can effectively function just like a crab would. The main hurdles there are engineering hurdles related to the *robot* part, not the *deep sea* part - though, in particular, *communication* between a human at the surface and a robot at ocean's floor is non-trivial.",
"Our machines and people can't stand high pressure because we have air sacs, our lungs. Deep sea animals don't have air sacs so they don't have this problem"
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6
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[
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|
[
"url"
] |
[
"url"
] |
ltobvv
|
will plants die of old age
|
Will a plant die of old age if it's given acquit water nutrients and light and kept in a safe environment where all its needs are met ?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp0a769"
],
"text": [
"With trees, they have two types of growth cells: The ones that make them taller and the ones that make them larger. The ones that make them taller will die off over time, but the other ones will just continue forever"
],
"score": [
5
],
"text_urls": [
[]
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}
|
[
"url"
] |
[
"url"
] |
ltpwv3
|
Color vs fluorescence
|
Hi, & #x200B; I got some fundamental questions which I could not find the answer to on the internet: & #x200B; 1. Objects have color because they reflect certain wavelengths. So, that must mean that the rest is absorbed? How is it possible that an object can only reflect 1 color? 2. What is the relation between color and fluorescence? How is this illustrated in a energy diagram? If all objects absorbs light, does that not mean that all objects are intrinsically fluorescent?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gp15vrs"
],
"text": [
"1. Yes, the rest is absorbed and becomes heat. You must consider that the spectrum of light is pretty much continuous, especially for macroscopic objects the definition of \"one color\" in the sense of a single wavelength doesn't exist; usually it is a whole band more or less wide of wavelengths that gets reflected. Furthermore consider that the human eye can only recognize three colors, every wavelength in between 700 nm and 635 nm for us is *just red.* 2. Color, as you said, comes from the wavelengths that are reflected. Fluorescence involves a few more steps: light first gets absorbed, loses some energy, and then is re-emitted with a longer wavelength (lower energy)."
],
"score": [
3
],
"text_urls": [
[]
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|
[
"url"
] |
[
"url"
] |
ltpy8a
|
why do you get a snuffy nose after eating spicy food
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp0m5cc",
"gp0rr2u",
"gp1jz3r"
],
"text": [
"You don't. Your airways are actually opened by spicy foods. You may experience watery eyes and with that comes post nasal drip which can cause you to have to blow your nose.",
"Never had that happen to me, normally I’ll get a runny nose and then it’ll eventually clear up soon after eating and blowing nose",
"You'll have to define \"snuffy\" as most people will read as \"stuffy\" or blocked, whereas most eaters of spicy foods experience sinuses opening up and runny nose as a result of consuming capsaicin, which makes spicy foods spicy."
],
"score": [
13,
8,
4
],
"text_urls": [
[],
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
|
ltq4o4
|
How do scientists know so much about planets so far away?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gp0njyo",
"gp0wg34",
"gp0o22r",
"gp0wyau",
"gp1rjka"
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"text": [
"They can tell by how much they \"wobble\" a star what the mass is, they can tell about the interval between dimming the star they orbit around how long it takes them to complete an orbit, they can tell about the light passing through the atmosphere what that might contain. Combining these factors and others allows you to make some assumptions about the planet. URL_0",
"Because of light. It sounds oversimplified, but really it’s incredibly fascinating to me. Light is generated by energy output by stars. Different stars output different kinds and amounts of light, including light we can’t see with our eyes. This is the electromagnetic spectrum and includes radio waves, gamma rays, and all the fancy rays. We can call all of that just **light**, and the lucky thing is that we know *exactly* how fast any kind of light should travel. Because we know this speed very precisely and under pretty much any condition, it is actually quite easy to know how far away a star is.* But if you stare at a star long enough, you’ll notice that every so often the star gets slightly dimmer in certain parts. This means something is partially blocking its light. The thing blocking its light periodically must be *orbitting* the star, so it must probably be a planet. We can tell how big it is by how much light it blocks, and how fast it moves by how quickly it moves across the star, and many other fascinating things can be deduced just by looking at how a star’s light is blocked by objects. Then there’s the fact that planets reflect light coming from other stars around them. At the right angle, we can see light from a star in one direction bounce off the planet and shine towards us. Again, if we estimate the time that takes, we can know how far away the planet is. Furthermore, because different elements reflect different *parts* of light, which we interpret as colours, we can compare the parts we see to our own catalogue of chemical elements and compounds and deduce what the planets are made of. For eg, we have iron here on earth, and we know that iron *absorbs* a lot of colours but mostly *reflects* red light, which is why iron is red. If we see a planet out there, and it absorbs and reflects the same parts of the light spectrum as iron does on earth, we can be pretty confident that there’s iron on the planet’s surface. Then we ask people who study rocks to tell us more details about *how* iron could have formed on the planet, because there’s only a few ways we know of that explain it. The last really cool thing, and this really blew my mind, is that we learned recently that light interacts with gravity, meaning objects that are really big and heavy that have a lot of gravity, actually *bend* light around them. So even if light isn’t reflecting off of a planet, and the planet isn’t obscuring a star’s light, It could still be possible to “see” things out there because they are *affecting* the light around them. If we see a lot of heavy things bending light, this just gives us more interesting ways to deduce what’s happening out in the cosmos. All because of light. *Note, astrophysics is not “easy”, but once we figured out the principle we’re trying to identify, a lot of stuff becomes easy to learn. That’s why you hear about scientists all of a sudden “discovering” a dozen interesting things a week",
"Exoplanets are observed with very good telescopes (Kepler is an orbital telescope especially made for this task) We can check what kind of light this planet reflects to see what kind of elements are in the atmosphere. Size and distance to their star can be measured by checking how much light of their star they block when passing in front, or how much the star \"wobbles\" from it's gravity. We know a lot for a tiny fraction of the planets that are out there because they happen to be in well observable places. There are billions of planets we can't see at all because their orbit is not aligned in a way they move in front of their star from our view.",
"We don’t *know* anything with certainty, but we *infer* a lot through observation of the effects they (the exoplanets) have on other things (like a gravitational interaction with a host star, or the light it reflects from that host star).",
"We actually don't know very much at all about exoplanets. A huge amount of what you read in articles about them is exaggerated or sometimes outright made up. At uni I did a project on exoplanets and my supervisor was keen to point out how unreliable science journalism is when it comes to exoplanets. What we can work out about them is roughly how big they are and what their mass is, and maybe how far away from the star it is. You can work out its size by observing the star over long periods and looking for a drop in the amount of light from the star. The light is dimmed by a fraction of a percent, so you need a good telescope to observe this, and you need repeated observations to make sure it's not caused by some other factor. You can work out its mass using the 'Doppler wobble' method. If a large enough planet is orbiting a star, it causes it to wobble back and forth in its orbit slight, and you can observe this as a doppler shift in the light from the star. Again, the change is a fraction of a percentage point, so you need a good telescope and careful observation. This gives you its mass and size, from which you can work out its density, and with all of that information you have a pretty good idea of what sort of planet it is (and by that I mean 'is it a terrestrial planet or a gas giant') and how far from the host star it is, and that's about it. If you want to learn anything about its atmosphere, you need spectroscopy. This means you look at the light that has passed through the planet's atmosphere, and you compare it to white light to see which part of the spectrum have been absorbed. From this, you can tell roughly what elements make up the atmosphere. This is a fairly recent method so we haven't done it for a ton of exoplanets yet."
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|
[
"url"
] |
[
"url"
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|
lts1aj
|
Why do we die naturally?
|
If you die in your sleep, why is it that the heart for example just decides: Okay let’s just start not working. Edit: I don’t mean heart attacks or strokes but more like “died in sleep, didn’t wake up next morning”
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp1akza",
"gp1b7f1"
],
"text": [
"Because our cells are constantly dividing and replicating new versions of itself but every time a cell divides the DNA gets damaged a tiny miniscule amount but over the course of 80 years that DNA damage starts adding up. and It gets to the point where more bad cells are created then good ones. Cells have a natural built-in system called apoptosis in which if they are not good they will kill themselves. If one or two cells do this no big deal but if most of them start doing this then problems are happening",
"Once one organ system starts to fail, without powerful medical intervention it starts to drag the rest down with it. When someone actually passes away “in their sleep” it usually means either the lungs failed or the heart did (oftentimes they both kind of fail at the same time in people who are old and ready to die). The part of your brain that controls those two organs is so low in the brain stem that barring a massive stroke, those usually fail on their own for any of a long list of reasons before the brain itself shuts them down"
],
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11,
4
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|
[
"url"
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[
"url"
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lts2nz
|
Why Spinal Injuries (Even Minor Ones) Are Next To Impossible To Completely Fix.
|
Biology
|
explainlikeimfive
|
{
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"gp1nzap",
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"Take one strand of overcooked spaghetti noodle. Break it. Now put it back together. Not so bad. That’s a nerve in your arm. Now take a whole fistful of overcooked spaghetti noodles. Rip those in half. Now reconnect them to the correct noodles without mushing any other noodle up. And do it while still holding them in your fist. That’s your spine.",
"Because the spinal cord is made of tons of nerve fibers. And nerves either don't repair themselves or do so very slowly. It's likely that all over the body, but the spinal cord is like the highway where all nerves meet and go to the brain. You damage that highway, and nothing works right",
"Any central nervous system injury is very hard to recover from because neurons don't get replaced for the most part and when connections are severed, it's very hard to have some recovery. It can happen tho, some people depending on the injury can have a very good recovery. Easily put, it's like your spinal cord is a major series of highway between two cities : your brain and your body, and informations like body position, motricity and sucj are cars on the roads.. During an injury, imagine a bomb dropping from wherever the fuc it came from and exploding on one of the highway and completely blocking the road : The connection is severed, the information cannot pass between the two cities. So you have two big problems : 1 - > The road is fucked. You need a new one. Theorically, it's not that hard to rebuild. 2 - > The explosion provoked a massive fire (inflammation) that will spread everywhere on the remaining roads if not contained : That's number 1 priority. SO you have firemen (immune system) and their buddies police officers (glial cells, others cells in the brain than neurons, they are essential for maintaining a good neuronal environment) coming to the site of injury. The fireman try to put out the fire and the police officers completely block the road and tell every road maintenance guy to fuck off and to repair the road later. But the situation is critical, and the fire is so big, that firemeen only have one option with the help of police officers, you need to condemn the road by building a massive sort of sarcophage around the highway that contains the fire. So that's what they do, they clean up what they can clean up, build a sarcophage (glial scaring) and thus the fire do not spread but the road is completely condemned and cannot be repaired. That's essentially why spinal injuries suck. The road is never repaired in order to kill the fire in order to avoid spreading the injury. The road tho never gets repaired because the sarcophage cannot be dismantled. That's a necessary evil action of the body. And keep in mind that even though rebuilding a new road is possible, the road maintenance guys are not the brightest and could possibly rebuild something wrong instead of the original road, that's also what your body tries to avoid by not repairing the injury.",
"Imagine you work maintenance at a google server hall. Imagine there's a room there where all the network cables go. Spanning across this room is the \"main cable\". Let's say this cable is 1 meter diamater, and consists of 25 000 network cables connecting computers with the servers. Now, undo the zip ties holding this bundle together so it isn't so neat. Okay, so one morning you learn that someone has gone into this room with a giant axe and just gone to town on the main cable. Your manager says *Nothing is working here! Could you go out there and put the cables back together?* So you have a room with 25000 network cables(oh and they all have the same color), where 17000 of them have been chopped off. Not cleanly either, some are chopped in two places so that many pieces are lying on the floor unconnected to anything. How would you go about fixing this? The answer is of course scrap all of it, buy a new cable and reconnect it all from scratch. IRL that means making a baby and killing yourself, basically, which maybe isn't the ideal solution lol",
"I just had a synthetic disc put in my neck between C5 and C6. The prognosis for this type of surgery is excellent. It feels better already. [Here is the how it works.] ( URL_0 )",
"The peripheral nervous system has an intrinsic ability for repair and regeneration, the central nervous system is, for the most part, incapable of self-repair and regeneration. There is currently no treatment for recovering human nerve function after injury to the central nervous system.",
"I’ve broken my back twice. T3/T4 the first go around. 18 months later, L4, L5 (and pelvis). (Skydiving can take a toll). I didn’t even know I had broken T3 and 4 until I had my second mishap. The doctors looking at my MRI for my lower back injury asked when I broke my upper back. Surprise. Surprise. Anyway, I got to meet some smart people along the way. It’s where I learned that a significant number of people who end up paralyzed don’t actually sever their spinal chords. A compression fracture of a vertebra (like what I did to my T3 & 4) can result in swelling around the spinal chord. The swelling can cut off blood flow resulting in nerve death and subsequent permanent paralysis. I was very fortunate that didn’t happen to me. (My T3/4 injury was caused by an extremely hard opening parachute. The second injury was an off-field landing resulting in a 30’ fall). The lesson to take away is: if you’ve suffered a traumatic injury to your back, see a doctor! A simple steroid injection can mean the difference between being sore for a few weeks or never feeling anything again!",
"Many of the nerves in the spinal cord are very, very long. A single neuron way up by your head can have an axon that goes all the way to the bottom of your spinal cord (not all of them are this long, but you get the idea). If it’s axon gets cut in two, the parts can’t reattach. The neuron would have to regrow the long axon, which would require a ton of energy and resources, and time. The neurons in the spinal cord (and brain) can’t grow back once they’re damaged for a few reasons: 1) they’re not designed to grow back very well. Scientists have found ways to encourage them to grow better, but not nearly well enough to cure spinal cord injuries. 2) When the spinal cord (or brain) is injured, a type of scar forms. This scar *might* actively block axons from re-growing (but this is a point of debate). 3) even if the axon grows some, it no longer has a way to know *where* it should go, or who it should connect to. So there’s a low chance of the neuron being able to do its job anymore. Fun fact: other animals, such as fish and some reptiles/amphibians, can recover from spinal cord injuries. Scientists are studying how they do it!",
"Essentially, in the spinal cord, a permanent “scab” forms on the end of the severed nerve still connected to the brain, so that’s why it’s so difficult to repair.",
"Medical Student: Dr. Frankenstein? Dr. Frankenstein: My name is \"Fronkenshteen.\" Medical Student: Dr. \"Fronkenschteen\" isn't it true that Darwin preserved a piece of vermicelli in a glass case until, by some extrordinary means, it actually began to move with voluntary motion? Dr. Frankenstein: Are you speaking of the worm or the spaghetti? [the class laughs] Medical Student: Why, the worm, sir. Dr. Frankenstein: Yes, I did read something of that incident when I was a student, but you have to remember that a worm... with very few exceptions... is not a human being. Medical Student: But wasn't that the whole basis of your grandfather's work? The reanimation of dead tissue? Dr. Frankenstein: My grandfather was a very sick man. Medical Student: But as a \"Fronkenshteen\" aren't you the least bit curious? Doesn't the bringing to life what was once dead hold any interest for you? Dr. Frankestein: You are talking about the non-sensical ravings of a lunatic mind; dead is dead! Student: But look at what has been done with hearts and kidneys... Dr. Frankenstein: [starting to shout] Hearts and kidneys are TINKER-TOYS!! I'm talking about the central nervous system!! Student: But, sir... Dr. Frankenstein: I am a scientist, not a philosopher! [picks up a scalpel] You have a better chance of re-animating this SCALPEL then you would of mending broken nervous tissue! Student: But what about your grandfather's work? Dr. Frankenstein: MY GRANDFATHER'S WORK WAS DOO-DOO!!! I am not interested in death! The only thing that concerns me IS THE PRESERVATION OF LIFE!!! [in his anger, Dr. Frankenstein stabs himself in the leg with the scalpel, grimaces, then crosses his legs] Dr. Frankenstein: Class...is...dismissed!"
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|
[
"url"
] |
[
"url"
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|
ltss6r
|
why are polar bears endangered
|
So this has been bugging me for a long time, what has polor bear 'hunting grounds' shrinking got to do with them finding less food? As the ice caps melt seal populations will have to move further into the ice to survive, and so less ice = less distance bears need to travel = less area for seals to hide So shouldn't polar bears bears be benefitting from global warming and seals facing extinction?
|
Earth Science
|
explainlikeimfive
|
{
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"text": [
"Polar bears also need the ice as places to stay, hibernate, give birth to pups, areas for Cubs to hone their hunting skills, etc., not to mention the rising temperatures goes against the selective pressures they’ve evolved to for millions of years (a thick coat; if you’ve ever seen an “Arctic” dog like huskies and they shed their coat in the summer, it’s so they can’t cook themselves to death during the summer, which polar bears can’t). Also, decreasing seal populations = less food = very damaging to a high mass animal (they are the world’s largest terrestrial carnivore). The reason why it’s an issue is because their functional diet breadth (basically how much stuff they eat) and the quality of their food (protein is high quality) means they need a lot of a specific range of foods, with them almost exclusively eating seals, and they need A LOT. So, food scarcity + increasing temperatures + a thick coat acting as a greenhouse + habitat loss + their naturally high mass = conservation calamity. Hope that helps! Edit: structuring and facts I forgot to address - mind has been scrambled recently, so my thoughts haven’t been as clear as I’d like",
"Less ice means less hunting ground which means less food. Moving further north doesn't mean there will be adequate food for the whole species. If you took all the deer in the world and put them in a 10 square mile area, they would starve to death.",
"Less hunting grounds means less food. Seals don’t just move to the ice, they die because they have to go further to rest, have more predators concentrated on them, etc. Less ice means less breeding grounds too. Less places to make a den. Having to swim further and longer to get from patch to patch. More and more calories burned, and less taken in. A slow death by starvation."
],
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5,
3,
3
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|
[
"url"
] |
[
"url"
] |
ltt1mr
|
How does geothermal energy work?
|
and how does it compare to carbon emissions?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gp1kk29"
],
"text": [
"Power plants all use the same principal, generate heat to produce steam to spin a turbine. Geothermal uses heat from in the Earth as that source of heat, instead of burning coal/gas. You run some pipes into the ground where there is natural geothermal activity, the water in the pipes pick up the heat and bring it to the surface where the steam is used to turn turbines and generate electricity."
],
"score": [
7
],
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|
[
"url"
] |
[
"url"
] |
lttd7f
|
how do bugs get into your light fixtures?
|
You know when you turn on the light in a ceiling fan or ceiling boob (you know, ceiling boobs), and then you see the silhouettes of whichever insect(s) have gotten trapped in there- how do they get in if it’s a closed space? Just saw a video of a guy who had a live scorpion in his bathroom fixture and it got me thinking...
|
Other
|
explainlikeimfive
|
{
"a_id": [
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"gp29a4l"
],
"text": [
"Hi...most bugs are attracted to light. Since they are bugs it's easier for them to fly or crawl into little tiny crevices of your light fixture. This is because most light fixtures have openings so that the heat of the lightbulb can escape. The bugs often get stuck in the light fixture and die from the heat from the lightbulb, thirst and hunger.",
"It's not a \"closed space\". In the case of smaller bugs, through/around the fixture. Even with ceiling boobs there's some amount of gap between the bowl and the ceiling. Bugs are attracted to light and can fit through tiny gaps. In the case of bigger things like a scorpion, from above. Inside the ceiling boob there's a wide open hole into the roof / space between floors. Which in turn is open to the walls, which may then be open to outside via vents etc. Scorpions aren't attracted to light, but they'd love a ceiling boob full of insects."
],
"score": [
16,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltu9nb
|
What's the thing happening when you see bright colours, while holding your hands over your eyes while they're shut?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp2rvyq",
"gp2f3ae"
],
"text": [
"Sensory cells become excited when they detect things. When they are excited, they send messages to the brain. In the eye, there are sensory cells called rods and cones, which become excited by light. Rods work better in the dark; when they are excited, they send signals that tells the brain 'there's light here!' Cones work better in bright lighting; when they are excited, they send signals that tell the brain 'there's color here!' Rods and cones are excited by light from the outside world, but some can also be excited by pressure. When you close your eyes and press on them, you excite some of the rods and cones, which send the same signals to the brain as they usually would: 'I can see light!' and 'I can see colour!' The weird things you see when you close your eyes and press on them don't exist in the outside world. It's just your brain's way of making sense of the weird signals that it's receiving. If you're seeing these colours without pressing on the eyes, though, then it's probably just your brain making stuff up because it's bored by the lack of messages coming from your rods and cones. Brains are weird like that.",
"Phosphenes are produced by pressure on the eye, which translates into various patterns by the optic nerve."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
|
ltuqxq
|
Why brain tumors/cancer exists if brain cells don't perform mitosis neither regenerate themselves?
|
As fas as I know, cancer develops after a mistake during mitosis pass unnoticed for both from both the own cell mechanism of regulation and the inmunitary system. But this does not apply to brain cells because they don't do mitosis yet you can develop cancer in the brain, so how?.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp25nxh",
"gp25asg"
],
"text": [
"You're absolutely right: most tumors in the brain don't arise from neurons, but from various other cell types: meninges (meningioma), support cells (astrocytoma/glioma, oligodendroglioma, schwannoma), tumors arising from embryonal cell populations (medulloblastoma), from the cells lining the brain's ventricles (ependymoma), cell arising from embryonic cartilage cell remnants (chordoma, chondroma, chondrosarcoma).",
"As has been alluded to in the previous answer, brain tumors are most often metastatic from somewhere else in the body. Primary brain tumors are far more prevalent in children because their brains are still developing AND this is where you're more likely to see bad genetic conditions that predispose people to cancer presenting with primary brain cancer (not always but generally). The biggest thing with development of cancer is that something happens that damages DNA and your body can't repair the damage. In cells that rapidly replicate, this is like setting the train of the tracks as with more dividing, the cells gradually accumulate more mutations. In cells with low to no cell division, you have exceptionally bad luck because the damage to your DNA just so happens to be in a place where it can turn cell division back on"
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltv0wt
|
why is General Sherman (~4M pounds) considered the largest tree in the world, but Pando is considered the heaviest living organism in the world (~13M pounds)?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp25zvx"
],
"text": [
"It comes down to your definition of tree. Pando is one individual genetically but is also a whole forest of normal sized trees where each tree is an offshoot of the first tree's roots. General Sherman is just an absurdly massive tree. :)"
],
"score": [
23
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltv6r2
|
Why do our taste buds prefer unhealthy foods compared to healthy ones?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp26x52",
"gp270bm",
"gp27sje",
"gp277k8",
"gp29ba8",
"gp2k2x2",
"gp2l7vq"
],
"text": [
"We do need some fats and sugars to surive and we evolved as hunter gatherers, so obtaining those things was very hard work. Our taste buds evolved to make us really like these things so that we would go and find them. Vegetables and fruits were pretty easy to find, so we didn't need as much of an incentive to eat those. The problem is that now we can get as much as we want of anything which is what causes us to be unhealthy.",
"Because sugar, fat and other sweet and oily things were once REALLY healthy. They're not healthy now because they're no longer rare and we eat a ton of them. Our far-past ancestors would have a much better chance of staying out of the reach of sabre-tooth tigers or bringing down that mastodon if they had the calories from a fatty or sugary meal in their system. Fat from land animals or oil from fish both have a super amount of calories. Same for sugars like honey from a bees nest. In the present day, we can just go buy those things in a store, but back then they were rare - herd animals in the wild really aren't as fatty as today's cows or pigs - or took a lot of work or risk to harvest. So we developed taste buds to pick up and crave those rare calorie-dense foods because calories were precious... and then we evolved into people that mass-produce candy and soda and fatty cuts of steak and pork rinds, which are now very common. Just nobody told our taste buds to change accordingly.",
"Because for the overwhelming majority of life on this planet, “not enough food” was a far far greater issue than “too much food”. So we’re designed to like things that get us the calories we need to hold off starvation: carbs and fats, with some protein thrown in there. Only within the last couple hundred years has too much food been a problem for a significant portion of the population, so our bodies have not adapted to that, because even now there’s not much evolutionary pressure to do so. Even people who weight 300-400 pounds don’t have so many health issues that they aren’t able to have children before 35, which means that there isn’t much reason to not have that stuff taste good. Keep in mind that while evolution eventually tends towards the most optimal configurations, in the short term it generally settles for “good enough”",
"Millions of years ago, humans were more likely to die from starvation or freezing (or injury or sickness for that matter) than they were of heart disease- the life expectancy was much shorter. So we are wired to eat things with calories- fats, carbs, proteins. Had cavemen only eaten broccoli we probably wouldn’t have survived as a species.",
"Most of human history and pre-history a constant surplus of sugar, salt and fat in our diets was not a problem. Quite the opposite. Our pre-historic ancestors evolved to seek out these energy and nutrient rich foods and eat as much of them as possible whenever they were available - which was often very intermittently. The move to a stable supply of economic processed foods has only existed for around 2-3 generations. Our evolution hasn’t caught up to the fact foods rich in salt, sugar and fat are now highly abundant and affordable. So we’re still biologically programmed to pig out on them. Processed food manufacturers know this and go to a fair amount of effort and research to put a mix of salt/sugar/fat into the processed foods that maximizes our evolutionary drive to shovel as much of it as possible into our mouths and then keep coming back for more.",
"our bodies as they are now are best evolved for hunter-gatherer conditions. evolution hasn't had enough time to catch us up to present day society. so the most useful thing for our tastebuds to prefer was high calorie foods. this is why you like things with high fat and sugar contents, these things have the most calories. I'm thinking you probably would have naturally gotten the other nutrients you need from your environment -- if you found food at all, it was likely to be nutritious. besides, if you're missing a nutrient here and there your body might not work in tiptop shape, but if you don't get enough calories you'll die. of course now we have the problem of too many calories, but this is a lucky problem to have compared with 99% of our evolutionary history.",
"What everyone is saying about human history is true. From another angle your body/brain/microbiome can he habituated to prefer junk food if you eat it a lot. Likewise if you are used to eating healthy food and take a trip where you eat out a lot and ignore normal diet you will likely be craving the healthy food before long. Say your brain/body is used to eating potatoes chips to get magnesium then that is what it will crave when it need magnesium. But if your brain/body is used to getting magnesium from almonds then it will crave almonds instead. Obviously it might be difficult to determine what the desire for a chalupa is for and it isn't always for one thing, but you can change your desires and food cravings eventually if you start eating a different diet."
],
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31,
8,
6,
4,
4,
3,
3
],
"text_urls": [
[],
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[],
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|
[
"url"
] |
[
"url"
] |
|
ltvnco
|
Is there any strategical or functional advantage to the shape of the B-2 stealth bomber? Why is it so geometrical?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gp2nc7k",
"gp2cs0h"
],
"text": [
"I know this is slightly left of topic, but I'm a bas-relief sculptor, working mostly for coins. Once, I had to sculpt a stealth fighter for a coin series about planes. Bas relief relies on light and shadow to create the illusion of form where there isn't any. Modeling the stealth fighter was almost impossible because the angles didn't bounce light and shadow at all. The whole thing looked flat, no matter how deeply I sculpted it. It was the same principle as being invisible to radar, just in a visible light spectrum.",
"The shape is designed to be invisible to radar. Radar detectors send radio waves off and then listen for an echo. Your typical aluminum cylinder-shaped aircraft with a big tail fin bounces a lot of radar signals back and shows up clearly. The B2 has this unique shape to minimize that signal reflection. The geometric design bounces radar signals off at odd angles instead of back towards any detector. It’s also coated in a secret and fabulously expensive radar absorbing paint to further dampen any signal."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltvpeh
|
Why is internal bleeding bad? Isn't the blood already there?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp2d163",
"gp2hhc7",
"gp2d5eh"
],
"text": [
"Because it belong in blood vessels, so there isn’t enough to go around the body. Also, it can put pressure on organs, so they can’t get enough blood either. Your body also isn’t great at reabsorbing blood in some places (like your brain) so it can do oxidative (basically electric) damage when it starts to break down.",
"That's kind of like asking why having a pipe leaking in a house is bad. The water's already there in the house, why is it bad? Because the water's going places it shouldn't, the water pressure is going to decrease so you may not be able to get as much water at the pressure you need it where you need it. In the case of a body, if the internal bleeding doesn't stop then blood keeps leaking into adjacent areas causing greater and greater inflammation. Depending on the rate of bleeding you might also have a dangerous to fatal decrease in blood pressure, and the amount of blood circulating around may decrease beneath a safe level. But blood just pooling in areas it shouldn't can do pretty big damage just by itself.",
"That's not what internal bleeding means. Internal bleeding involves blood getting out of the blood vessels and into the surrounding structures. This is not where blood is supposed to be, and there is no blood in these areas. Only blood inside the vessels can move around appropriately and do its job. Blood that's leaked inside you is like the blood in a bruise. It ends up dying there and it's just another mess for the body to clean up."
],
"score": [
10,
6,
4
],
"text_urls": [
[],
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
|
ltvqx9
|
Why is ice more slippery than for example glass (or even wet glass)
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gp2fbg3",
"gp2tpvl"
],
"text": [
"Water has a weird property where if you add pressure to it ice (e.g step on or crush it) it turn back into a liquid, which makes you slip.",
"Ice is slippery because given enough weight/pressure or warm enough temperatures it’ll form a thin layer of water over the surface. It’s this layer of water that makes it slippery. Try it out. Most ice isn’t actually that slippery on really really cold days because it stays dry. Alternatively spray a thin layer of water on a glass surface and see how slick it becomes."
],
"score": [
5,
3
],
"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
|
ltvvva
|
Why can't we use stainless steel flask to store whiskey for longer than few days?
|
It contains a lot of alcohol like 40%+ so any bacteria shouldn't grow inside. Can it poison you or kill you or does it only affect taste or something?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gp2hux4"
],
"text": [
"Alcohol is fermented in stainless steel barrels, so this is a good example of irrational herd behavior. Most humans act by copying other humans that have been successful at something. When humans copy something they rarely understand *why* they're doing it, they just understand that it \"needs\" to be done. What this means is that sometimes they copy things that don't actually have any meaning and don't actually have to be done. A good example of this is the \"this movie does not depict any real people\" disclaimer that you see at the end of the movies. That disclaimer does literally nothing. It came into existence as a result of a poorly worded legal opinion out of a California court 100 years ago. Essentially, some studio executives who didn't understand the opinion started putting that disclaimer in the credits to their movies and everyone has just copied it since. This copying of the disclaimer is so prevalent that its extremely common to see it pop up in foreign media that will never be shown in the US. For example - just about every German TV show contains this disclaimer in their credits even though there's never been anything in Germany related to it. The reason its there is because German TV producers learned how to make TV shows by copying American TV shows and since that disclaimer was in all of the American TV shows it ended up getting copied as well. So why do those flasks say not to store alcohol in them? Because at some point some manufacturer put that warning on a flask. Other manufacturers then saw the warning and copied it because they assumed that it was there for some purpose. And now you have a bunch of people trying to back rationalize why this warning is on every alcohol flask. This is a relatively recent thing and is mostly likely the result of a large Chinese manufacturer who saw warning labels on other US products and didn't understand why they were there. But there is no reason for the warning. If alcohol was going to cause some reaction with the flask then it wouldn't matter how long you stored it in there - the flask wouldn't be safe for you to drink out of at all. And again, the fact is that alcohol is fermented in stainless steel barrels. There is nothing special about those barrels. If those barrels are safe to store alcohol in then so is your flask."
],
"score": [
79
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ltvyt9
|
Why are bananas parabolic?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp2vryp"
],
"text": [
"The explaination I am aware of is that bananas start growing out at an angle.They try and grow upwards at the tip. As the get bigger their weight causes them to tip outward while.the tip continues to grow up. This ends up making the curvy shape. (With the bananas pointed up: URL_0 )"
],
"score": [
3
],
"text_urls": [
[
"https://images.app.goo.gl/1YV9o1M6MnaE8t6W7"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltw34a
|
If a gigabyte is 10^9 bytes, then why do common technologies use numbers like 32, 64, 128, 256 gigabytes instead of something like 100, 200, 500 to easily file into 10s?
|
What is the purpose of these seemingly arbitrary multiples of 2
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gp2hbbr",
"gp2nxz0",
"gp2pbtj"
],
"text": [
"It's important not to mix up gibibytes and gigabytes. Colloquially we use the word \"gigabytes\" for gibibytes but one is base 10 and the other is base 2. 2^30 vs 10^9",
"In low level, computers don’t work in base 10, only in base 2 (binary, only ones and zeros). Because of that, storage also have to be designed and organized in blocks of multiples of 2, when you see something advertised as a gigabyte (10^9), it’s actual size is a gibibyte (2^30). It’s just called a gigabyte because modern humans think in base 10 and it’s easier to estimate what 10^9 is than 2^30. Some websites actually have disclaimers to clarify things when they sell you a product (I think there are such disclaimers on Apple’s website).",
"Okay, first there's a terminology difference. Traditionally in the computer fields people used the following definitions: - Kilobyte: 2^10 or 1,024 bytes - Megabyte: 2^20 or 1,048,576 bytes - Gigabyte: 2^30 or 1,073,741,824 bytes Once computers started to get really popular, in the late 1990's this made some people start to get grumpy about the situation. Those grumpy folks said basically \"Okay guys, the whole rest of science uses kilo to mean 1,000, mega to mean 1,000,000, and giga to mean 1,000,000,000. If you insist on working with numbers like 1,024, 1,048,576 or 1,073,741,824, you can't call them kilo, mega, and giga. You have to call them something else, how about kibi, mebi and gibi?\" So there are now two camps of computer folks. One camp agrees with the grumpy pedants and use \"gigabyte\" to mean 1,000,000,000. Your question says \"a gigabyte is 10^9 bytes.\" So you would be in this camp. But there's another camp. There are a lot of people in the field who prefer the older traditional usage, and will use the word \"gigabyte\" to refer to 1,073,741,824. The kibi / mibi / gibi prefixes sound a little silly, and they never took off in terms of marketing or advertising of computers and related products. For example, effectively all RAM actually has power-of-2 sizes, but I doubt you'll be able to find any RAM for sale anywhere that's advertised or labeled using \"gibibytes\". As to why they pick powers of 2, it comes from the number of possible patterns in some number of wires carrying digital binary signals. If you have say three wires, there are eight possible signals: 000, 001, 010, 011, 100, 101, 110, 111. If you want to represent eight possible values, it works great. However if you want to represent ten possible values, three wires is too few, but if you add a fourth wire and start counting combinations: 0000, 0001, 0010, 0011, 0100, 0101, 0110, 0111, 1000, 1001 -- that's ten -- but there are still some combinations left, 1010 1011 1100 1101 1110 1111. You'd need to then have an extra circuit to detect these \"extra\" combinations and have the chip do something else. That extra circuit has actual costs in terms of size, power usage, speed and money (not to mention extras design / testing). So designers instead try to match the sizes of things to the number of combinations available on particular wires, in particular powers of 2. If you think in binary, it makes a lot of sense. One billion only looks like a round number to us because we use a decimal (base-10) number system. To a computer scientist who thinks in binary (base-2) number system, one billion is `111011100110101100101000000000`. Which is very not-round, at least when you compare it to 1,073,741,824, whose binary representation is `1000000000000000000000000000000`."
],
"score": [
8,
6,
6
],
"text_urls": [
[],
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}
|
[
"url"
] |
[
"url"
] |
ltw7us
|
Why is it so difficult to mate endangered species and increase their populations in the same way we mass produce cows and chickens
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp2ldzm",
"gp2m5xi",
"gp2k7k6",
"gp2wrfs"
],
"text": [
"Most animals don't take well to being locked up in captivity, they don't breed, they don't eat, they kill themselves trying to escape... They won't raise their own offspring... Another problem is that the natural territories of these animals are in other countries, and they are low on their governments' list of priorities. So for example laws against poaching aren't enforced because the government doesn't have enough funds to allocate to that; they have too many other issues in their country that need funding.",
"Domesticated animals like cows have been selectively bred and although it’s not the primary trait farmers have looked for the selective breeding has included a tolerance for human proximity, so can be readily bred on farms. Their habitat is also one that is commercially viable to provide - pasture - because were farming the animals. Many wild animals have a low tolerance for proximity to animals they perceive as threats - and humans certainly qualify here. Captivity, particularly with close human proximity, puts stress on them that discourages reproduction. Large wild animals (eg rhinos, pandas, etc) also have a strong preference for a large habitat. If they don’t believe their habitat needs are being met they won’t breed. Further - if bred it is often challenging to release them into the wild, as the primary factors for why they are endangered are: 1. Loss of habitat, mostly due to humans. 2. Poaching, entirely due to humans. Lost habitat has been lost because we’ve taken it for other uses. And animals that get poached are still highly targeted by poachers. So even if we could mass breed them it would be extremely challenging to repopulate wild populations as there’s nowhere to put them and even when there is people frequently kill them. Then we come to captive populations - many of these animals are very resource intensive to maintain in captivity so have to be commercially viable within the budgets of zoos, which are often very tight. Zoos flatly cannot afford to mass reproduce them.",
"Because you need an animal which can live in the wild, so you can't just put them in captivity and later release the offsprings, they would die. Said this not every animal can be held captive. Some just don't easily breed in captivity, others literally die in captivity like great whites",
"There are a few different reasons that can apply situationally. While any animal can in theory be kept and bred in captivity if we provide it with a perfect enclosure, that isn't always possible. Sometimes the perfect enclosure would simply be unreasonably expensive to build, such as with large whales, but more often its because we are missing some crucial information about some subtle element(s) the animal needs. Great white sharks for example are incredibly hard to keep alive in captivity, even though the much larger whale shark is not only possible to keep alive in captivity, but actively thrives! This is because whale sharks despite their size live in relatively shallow and tropical areas that are easy to replicate in captivity. Their social behaviour is also very easy to research partly because it's easy to keep them alive in the first place and partly again because they live in places we can easily observe them, making even their abstract needs easy to meet. Great white sharks however are found in a wide range of areas, including a wide range of temperatures and water depths. We really don't understand exactly when and how they require (or even if they require) access to different kinds of habitats. There is also sometimes political pressure on obtaining the animals in the first place. Giant pandas are the prime example here, as they are \"claimed property\" of the Chinese government. You \"can't have pandas\" unless the Chinese government says you can, and they don't exactly loan them out for free. Other examples include animals that live in very poor areas that can't afford to provide them with protection or proper captivity, but also refuse to let foreign organizations take them."
],
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8,
4,
3,
3
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|
[
"url"
] |
[
"url"
] |
|
ltwbe5
|
What is the difference between soap and detergent?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gp2lj5c",
"gp2lmxa"
],
"text": [
"The amount of surfactants are higher in laundry detergents. Surfactants are the molecules that bind with oil on one side and oil on the other. Dirt bonds with oil, oil bonds to the surfactant and water and since we remove the water the dirt and oil go with it. No matter which you use the important thing is always to rinse well.",
"Most cleaning products today are detergents. One of the biggest reasons for this is the way soap reacts with water. While detergents are free-rinsing (meaning they don’t leave a residue), soap needs a clear water wash after application or it will leave a film. As a side note, a number of commercial hand care products still have the word “soap” in their name, even though they are really detergents."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltwdv5
|
Why does economy have to grow continually?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gp2lr96",
"gp2ox7q",
"gp2m8lc"
],
"text": [
"Well for one, the number of people increases every year, thus the amount of work performed by a population as a whole increases. If your economy isn't increasing at the very least with the amount of people entering the workforce then you are doing something wrong. Overall though we at the very least expect things to get better and not worse.",
"There are two forces that we think will generally increase economic activity so long as we avoid total dysfunction. First, the population will grow. If you have more people to make stuff, you should make more stuff (if only because you now have more people who *want* stuff). Second, we will become better at making stuff. Maybe we learn a more efficient way to produce something we already like or maybe we invent something entirely new. If the economy stayed the same size or shrank, this suggests that there was some negative force that worked against these two \"natural\" growth mechanisms. Most years this doesn't happen, so economic growth is what happens when there's nothing special going on.",
"The growth of the economy needs to outpace inflation. If it does not wage earners making the same amount as last year will lose purchasing power. Inflation is necessary to encourage spending. If my dollar will be worth less next year, I’m more apt to spend."
],
"score": [
7,
6,
3
],
"text_urls": [
[],
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
|
ltwub7
|
Why do some tasks release enough dopamine to keep you engaged for hours (scrolling on a phone app) while other tasks with similar effort output (answering an email/doing work on your phone) seems so exhausting?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp2qw1w",
"gp2se56",
"gp3pr8o"
],
"text": [
"I might be wrong here, but here's my understanding of it. You naturally optimize for most dopamine from least effort. Thinking burns energy, so theres much more spend on a thought out email or in depth discussion, vs passively taking in posts. Posting memes or short posts has slightly more spend, but with a much higher potential dopamine payout - 100s or 1000s of upvotes. Emails generally have a smaller audience, only a few payouts on dopamine.",
"Dopamine is largely used as a \"reward\" in the brain, getting released when you complete something. Social media is engineered so that you are interacting with potentially dozens of posts each minute, with each interaction counting as a \"completion\" and earning that dopamine kick. Additionally, when you've interacted with one post, the post right below it serves to \"tease\" your brain with the prospect of another kick, keeping you engaged in the app.",
"You get excited by watching good apps etc vs boring work jobs, doesn't matter how much you are moving your thumb etc. It's all in your head"
],
"score": [
8,
6,
3
],
"text_urls": [
[],
[],
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}
|
[
"url"
] |
[
"url"
] |
|
ltwyjo
|
Why does computer memory and storage capacities always double? ie 16gb, 32gb, 64gb, 128gb.... etc
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gp2rnxi",
"gp2rszx"
],
"text": [
"This is actually a question fairly like another question asked here just a couple of minutes ago. [ URL_1 ]( URL_0 ) I think the comments on that thread can answer your question as well ;) & #x200B; OK short edit. In addition to it being easy for computers to calculate memory addresses in amounts of 2\\^x, it's also simply easy to double it. Have 1 GB of RAM? Put in one extra and you have 2. Double the amount of chips per unit of RAM, and you go to 4, etc, etc.",
"Every time you add memory storage you add the ability to store an extra 1 or 0, that means you double the possible combinations that could exist before. With 1 slot: 0 1 With 2: 00 01 10 11 With 3 000 001 010 011 100 101 110 111 And so on"
],
"score": [
5,
3
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"text_urls": [
[
"https://www.reddit.com/r/explainlikeimfive/comments/ltw34a/eli5_if_a_gigabyte_is_109_bytes_then_why_do/",
"https://www.reddit.com/r/explainlikeimfive/comments/ltw34a/eli5\\_if\\_a\\_gigabyte\\_is\\_109\\_bytes\\_then\\_why\\_do/"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltx17l
|
Why are the larger elements more unstable and radioactive the closer to the bottom and right of the periodic table you go?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gp2y4qi"
],
"text": [
"It gets progressively more difficult to smoosh that many protons together without them flying apart. You know how opposites attract? Protons aren't opposites of each other, and they're not really hyped about hanging out. They tolerate it to a certain extent but eventually it's just too much and they can't stand each other anymore"
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ltxei1
|
Why are fully open eyes so unsettling?
|
I have never really noticed it but why are fully open eyes so creepy Momo, rei in Evangelion, the girl in the opening of live and let die and I'm sure there are many more examples. I understand most fears are primal so why are they so creepy?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gp2x31j",
"gp2xee4"
],
"text": [
"It's disturbing on a biological level because humans only open their eyes fully in moments of great fear or wonder and fear is way more common than wonder. It's a bit of facial body language that says \"I'm fucking terrified and maybe you should be too.\" During times when they feel threatened humans open up their eyes wide to scan their surroundings for possible routes of escape or anything else that might help them against whatever it is they're fearing at that moment. Fear is very contagious in most species including humans so seeing another human in this state even in a video or picture can trigger a panic response at some level.",
"When you experience a life threatening situation your body is flooded with chemicals like adrenaline. Those chemicals prepare you to fight or flee. They cause your body to react in a bunch of ways. One is to make your eyes open wide. When you see someone with very wide open eyes your brain recognizes on an instinctual level that that person is ready for a fight or flight situation. They’re prepared for violence. It triggers your brains own adrenaline response. If the person with wide eyes appears to be calm that leads you to further question their motives. What are they planning for? Are they unstable? It makes them appear dangerous and untrustworthy."
],
"score": [
9,
5
],
"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
lty6rp
|
How does a privatized electrical grid work (like in Texas)?
|
Edit: I mean like, how is it \*supposed\* to work - not counting whatever went wrong recently in Texas. I mean, each "provider" doesn't have its own wires running to each subscriber, right? So what exactly does a provider do? Just some fancy accounting? Does each provider have their own power plants, or are they just buying power from existing power plants? Does a provider necessarily own any of the infrastructure at all? (power plants, transformers, poles, wires, etc).
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gp4v2v2"
],
"text": [
"There is 3 steps to you getting power. Production, distribution and retail. The grid is the distribution part. It's the utility. If it's privatised then the government has sold, leased or entered into a contract with a private company, for them to run it and reap the profits. The grid is almost always a monopoly because multiple sets of powerlines is dumb. They act as middle men between providers and users and are responsible for the upkeep on the grid. The idea behind privatisation of essential services like an electrical grid is the idea that a private company is more competitive, I.e cheaper, than the government. So privatised production, where companies can compete is a potentially good idea. Privatised distribution that is granted a monopoly means that competition is impossible."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lty8ny
|
Why is fog transparent when you are in it but opaque when you are outside it?
|
Whenever I see some fog, it usually is very opaque when I am far away, like cloud, but when I am it, it's far more transparent, though obviously visibility is decreased
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gp34jmh",
"gp34mfb"
],
"text": [
"Volume. Let's say one cubic meter of fog reduces the amount of light going through it by 2%, so having one meter of fog between you and, say, a rabid bear would obscure your vision of it by a little, but not a lot. Now, if the density of the fog is consistent throughout the forest you're in (forgot to mention, you're in a temperate evergreen forest), then you just by moving your body, you change how much fog is between you and the bear, and how clearly you can see it. Closer to the bear = less fog and more visible light that reaches you. If you're standing outside the cloud entirely, then whatever is on the other side is going to have to pass through the cloud entirely for you to see it. If there's enough fog to almost completly block the light, then all you're going to see is the fog.",
"The more fog between you and the object you want to see, the less you will see it. If you look at fog from afar, you're likely looking through a lot of fog (because there is just nothing else there but air). But if you're inside, you can focus on objects that are close enough to still see them somewhat, and you'll just ignore anything farther away."
],
"score": [
9,
3
],
"text_urls": [
[],
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]
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|
[
"url"
] |
[
"url"
] |
lu090n
|
How do we know what color dinosaurs were if all flesh has decayed?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp3jsju",
"gp3x284",
"gp3jyvv"
],
"text": [
"Depictions of dinosaurs are made with informed, artistic license. Artist, with feedback from evolutionary biologist and other scientist, draw what they think the animals might have looked like, based on how animals today look.",
"In most cases, we can't. We just have to make educated guesses based on their lifestyle, environment, and closest living relatives (i.e. crocodiles and birds). In a few rare instances, fossils (usually of feathers, but sometimes of skin) can preserve pigment structures called melanosomes which can be analyzed and interpreted. Sometimes this tells us the color, sometimes it just tells us an animal had spots or stripes. For instance, since c. 2012 we have known that archaeopteryx' feathers were black.",
"We don't know for sure. But we know what colors big lizards and birds are today, and as we get a better understanding of how they're related, we have more reason to think they probably looked like their living relatives."
],
"score": [
15,
9,
5
],
"text_urls": [
[],
[],
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}
|
[
"url"
] |
[
"url"
] |
|
lu0jdi
|
What happens when you drink something and feel it “go down the wrong pipe.”
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp3lzd9"
],
"text": [
"When you eat or drink, the “pipe” that leads to your stomach is called the esophagus. You have a second “pipe” that leads to your lungs, called the trachea. When something goes down the wrong pipe, food/liquid that is meant to go down you esophagus goes down the trachea because of improper swallowing. Your body responds by coughing or choking to force the food or liquid out of your trachea and prevent it from entering your lungs and causing infection."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lu0mhc
|
How is gold so valuable and the basis of currency, if it's just being stored and not used for anything?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gp3n4k7",
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"gp5ajwy",
"gp3wjht",
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"text": [
"Back in the past, gold was valued as a precious metal because it was shiny and pretty. And soft, which meant it could be shaped easily. It was used as money because it *was* a precious metal, so it was a store of value. It didn't rust, could be made pure, could be made less pure, could be formed into standard-ish shapes like coins and bars. So it was useful for trade with strangers.",
"I don't believe any currency in the world is still backed by gold. Back in the day you were able to take your paper money to the bank and exchange it for gold.",
"Because people agree it is, basically. Money has always been something of an illusion - it's there so people don't have to barter and figure out what the change is when you pay for two cows with a large pig and several chickens. For instance. Currency is just something that physically represents money or value - a lump of gold, a coin, a banknote, a check, etc. Gold got used, back when, because it was shiny, easily shaped, and didn't rust; lumps of it stayed the same, and could be tested for purity fairly easily. (If you see someone biting a coin in a book about older times, that's actually what they're doing, seeing how soft and workable it is.) Where it's piled up in a vault, it's there to represent \"I have all this value stored here\" and \"Other people agree, pretty much, on what one of these gold bars is worth, so I know what I'd get it if I sold it and got cash for it\". Most money (maybe all?) these days isn't \"backed by gold\" any more - the government doesn't need to keep certain quantities of gold in a vault and, on request, exchange bits of it for bills or coins. The idea that money's worth what everyone agrees it's worth is what supports currencies nowadays, and is why different currencies rise and fall in value relative to each other; sometimes investors think Canada and its currency is more stable and investable in, and sometimes they think the USA's, or China's, or Begium's euro, is. --Dave, cryptocurrencies basically work this way too; there, what \"backs\" them is that there's a finite amount of SOMETHING related to it available, or else the game it's used in values items at shopkeepers at certain levels. etc.",
"It's shiny, rare, and doesn't rust. That's it. In fact, the fact that we don't use gold for anything important makes it more useful for currency because we don't have to worry about using it all up. Money is just weird like that.",
"Gold was used as a currency because it was malleable and it didn't corrode. I don't think there's a currency currently backed by gold either, but when it was, a gold backed currency stopped inflation as the government couldn't print money past it's gold supply."
],
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18,
11,
4,
3,
3
],
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|
[
"url"
] |
[
"url"
] |
|
lu1ewb
|
Why the electricity in our bodies can't power devices in our bodies (like a pacemaker).
|
I was thinking about this today, and I'm sure I'm not the first. But what are the limiting factors in being able to power electric devices inside our bodies with the currents that are created naturally by our own bodies? Do we naturally not supply enough energy or enough surplus energy? Do we not have the interface technology? Is it even theoretically possible? Seems like it could be a gamechanger to utilize ourselves as a power source instead of needing to replace devices batteries (like a pacemaker).
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp3r4gm",
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],
"text": [
"> But what are the limiting factors in being able to power electric devices inside our bodies with the currents that are created naturally by our own bodies? We don't produce that much electricity + there's no interface for it. The whole heart is a natural pacemaker with particular nodes in it that have a tendency to pace faster than the rest of it, which basically sets your normal heart rhythm. We use pacemakers when the electrical activity doesn't conduct through your heart properly or there's a risk that it might spontaneously go into a rhythm that's dangerous for your heart. Electricity doesn't just like flow back and forth through our body, it has very directed and purposeful circuitry that serves to do certain things. It's not like we can just redirect current from some random part of our body to our heart - and even if we could - the energy used in pacemakers is much higher than what you'd normally find in your body. Plus, other than your heart, there's no natural capacity to regenerate the energy required for pacing that the pacemaker would require. With minimally invasive surgeries today, a pacemaker can last quite a while and batteries only need to be replaced every few years in a minor surgery. They're not as large nor as problematic as they used to be in the past.",
"One thing that's important to note is that there really isn't much in the way of electrical *currents* flowing around our bodies. The actual flow of current, in real terms, is tiny. Like, on the order of microamperes. This is because electricity is not used by our bodies to move energy around to do work, electricity is just used to send signals around the body, and to trigger the release of other kinds of stored energy to actually do things. And you can send an electrical *signal* with almost no power at all."
],
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20,
6
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
lu27yv
|
Is maple syrup equivalent to blood?
|
Earth Science
|
explainlikeimfive
|
{
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"gp3vnve",
"gp3vfu5"
],
"text": [
"Sort of. It transports water and nutrients in the same way your blood does, although it isn't actively \"pumped\" in quite the same way (it's just drawn slowly upward as leaves lose water). Unlike blood, it doesn't carry oxygen, which is why it tastes very different (the taste of blood is mostly the taste of iron, which is used in red blood cells to carry oxygen). ED: As a below poster correctly notes, syrup is a very reduced form of sap. This post is about sap, not syrup *per se*.",
"Answer: no, it is not equivalent to blood. They're both liquidy and have sugars, but I wouldn't recommend using it for a blood transfusion. It's too thick and too slow, among all the other issues with it. But at least you'd be tasty I suppose."
],
"score": [
10,
4
],
"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
|
lu2fcy
|
Why are the top 10 countries with the highest obesity rates all Pacific islands?
|
Is it a genetic thing? I know Pacific islanders can be prone to putting on a lot of size, muscular and otherwise, or is it something to do with the diet in the region, or influence from the West?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"Cultural influence of the western diet, genetics, and poverty all play a role in that. Readily available and cheap food that’s full of high fructose core syrup and other carbs for the poverty part, genetic dispositions, etc.",
"I remember learning in anthropology (20 years ago, so there might be more current info out there) that it was likely an evolutionary advantage. Many Pacific Islanders traveled the ocean covering great distances by canoe. Even if it is warm on land, traveling in an open boat, with sea spray hitting you all the time, is cold business. Fat stores helped immensely. Additionally having a larger frame and carrying extra weight was a sign of wealth in some places, because it meant you were eating well. I remember we read about a remote island in the Pacific that got television in the 1980s or 1990s. There was a sudden epidemic of eating disorders on the island immediately following the introduction of television. Western beauty ideals hit the community hard, and caused a lot of chaos, depression, and self esteem issues.",
"It is I believe related to traditional cultural pressures to be large. Eating habits compliment this.",
"Another reason will be the type of food available. Small islands don't necessarily have a lot of space to grow fresh fruits and veggies. Everything pretty much comes in on boat. Healthy and fresh food doesn't ship well, canned food chock full of preservatives, salt and sugar does.",
"It's cultural. There was a long-standing cultural belief that big = beautiful in these places. With food now being abundant thanks to modern technology, it was possible for everyone to eat to a degree far in excess of what was previously possible."
],
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10,
5,
5,
3
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"text_urls": [
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|
[
"url"
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[
"url"
] |
lu34tq
|
What is Einstein clock synchronization?
|
And how does this relate to the relativity of simultaneity?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gp412tz"
],
"text": [
"So we have clocks, they measure consistent intervals of time. Except, we can't be sure that all of them are exactly the same intervals, because we don't have any clocks to measure against. So one of Einstein's definitions when he figured out special relativity is that the speed of light is constant in all inertial reference frames. Using that, you can find that a clock made of a beam of light and a light detector will always be accurate in its reference frame. What you can do, is synchronize two of these clocks by starting them at what you define as 0 in both reference frames. Then, if the velocity between the two different frames is significantly close to the speed of light, you'll find that any other measurements you make will happen at different times. That's the \"relativity of simultaneity\"."
],
"score": [
6
],
"text_urls": [
[]
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|
[
"url"
] |
[
"url"
] |
lu3ag6
|
Why do hot chocolate and chocolate milk taste different?
|
The other night I wanted chocolate milk but didn't have chocolate syrup or cocoa powder. I just heated up some hot chocolate mix in milk and then put it in the fridge for an hour. When I drank it I can't explain, but it tasted like hot chocolate (even though it was cold). It did NOT taste like chocolate milk. So, why do the two chocolate powders (hot chocolate mix and cocoa power) taste different in milk?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gp41vi6"
],
"text": [
"Best way to find out is to read the ingredients. It's pretty common in my experience for the two to be made of different things, particularly in sugar ratios. Also, heating up the milk will have denatured a lot of the proteins in it (changed their shape) which might alter the taste of the milk itself. You could try testing this by pouring a cup of cold milk and also refrigerating a cup of boiled milk and seeing if they taste different."
],
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10
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
lu3y5f
|
How did emergency service drivers find addresses before the internet?
|
I get knowing an area but they covered such a large space and couldn’t know every street and house off the top of their head. So how did they figure out exactly how to get to everywhere they had to go?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gp45iac",
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"gp4hf95"
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"text": [
"Paper maps, street signs, and local knowledge. The map would get them to the correct street, street signs have block numbers on them helping narrow down which direction they needed to go on that street, barring that I’m sure someone on the other end of the CB would be able to help them out.",
"Maps. Many places make still you memorize the area you’ll be covering before you can drive.",
"Maps and knowledge. Even in modern times when I was in college I was expected to know the names of every building on campus and every street of the neighboring college town. Thats our beat and we just needed to know it.",
"The volunteer fire brigade in the town where I grew up had a card for every street in the town, which had turn by turn directions. The driver would got and grab that as the other volunteers were suiting up and whatnot. The guy sitting shotgun would read the card as they went."
],
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3
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|
[
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[
"url"
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lu4wsj
|
How does saving for retirement work?
|
Economics
|
explainlikeimfive
|
{
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"text": [
"A lot of people rely on 401(k) (employer provided retirement plan) or Individual Retirement Account (IRA) to save for retirement. Anyone can open an IRA at any time, it's worth looking into. Even if you only put a little bit away each month it'll grow faster than it would if it were in a savings or checking account. Better to start looking into things now rather than later. Every year that passes, your money loses some of that buying power and it takes *more* of an investment to make up for what someone else already made saving *less* money (for instance, a person who put away just $500 at age 18 might have grown that to $5,000 by the time they are 40. Not a lot, but if you're 34 and put away $500 it might only grow to $1,000. This is a really basic example that's not rooted on hard factual numbers, just trying to illustrate the point). edit: The advantage to either of those retirement plans is that they are tax deferred. With one type your money is dropped in after it's taxed and then it can grow and grow and you don't pay taxes on whatever you withdraw. With the other type the money is *not* taxed until you actually start withdrawing it.",
"> How? Most large companies will give you the option of enrolling into a retirement plan where a small cut of your paycheck (something like 10% but it's up to you) gets deposited into the account. The money is managed for you, when you're young it's put into high risk, high reward investments like stocks and gradually as you get older the money is shifted towards more stable investments like government backed bonds. These accounts offered by your company usually incentivize savings by matching a certain percentage of what you put in, e.g. they'll offer 5% matching, if you put in 10% of your paycheck they'll add in another 5% making the total 15%. If your company doesn't offer a retirement plan your bank or credit union usually does. They're called IRAs or individual retirement accounts. > Why? I don't make much money so I wouldn't be able to put much away. Is it really something I should worry about right now? Because social security alone won't be enough for you to live off of and eventually you will want to retire; you don't want to continue working until you're 80 because you didn't save money when you had the chance. Most jobs these days also don't offer a pension that pays you for the rest of your life after you retire.",
"To be honest you should have started worrying about it 10 years ago. You need to look up conpund interest on Youtube and start doing some math on what you're savings are gonna look like.",
"Assuming a 7% rate of return on your investments (good but not crazy good), your money will double every 10 years. You have about 30 years to retirement, so 3 doubling periods. If you put away $1000 today, you should have $8000 by the time you retire ($1000 doubles to $2000 after 10 years. $2000 doubles to $4000. $4000 doubles to $8000). Even a relatively modest investment is better than nothing. This bit is specific to the US so if you’re not American, disregard. Since you’re not making much money, open an IRA. You put after tax money into an IRA. That means your income taxes come off the top and you put what’s left to your expenses and an IRA. IRAs grow tax free. So no matter how much money it turns into in the future, it’s yours free and clear. A 401(k) comes out before your taxes (like employer provided health insurance premiums). That’s great for lowering your taxable income and if you have an employer who matches, it’s free money. But when you cash in your 401(k), you pay income tax on it. If you’re not paying much in income taxes because your income is low, you don’t need the tax break of the 401(k)."
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|
[
"url"
] |
[
"url"
] |
|
lu4wvh
|
What is "Time" and how exactly does it work?
|
Physics
|
explainlikeimfive
|
{
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"text": [
"they're hard to answer, because the two theories we have about how the universe work. treat time differently. According to Special Relativity (which successfully explains virtually everything we know about huge astronomical bodies), time is one dimension of 4-dimensional *spacetime*, and different bodies can move through it at different speeds depending on their motion through the 3 spatial dimensions. According to quantum theory (which successfully explains virtually everything we know about particle physics), time is just a background measuring stick that ticks by at a set rate always. These two understandings of time aren't compatible with each other, and neither theory can work with the other definition of time. So, time is one of the basic elements of existence that's still really really hard to figure out. Honestly, I know links are discouraged here, but the wikipedia article for Time might blow you mind with how little we understand it.",
"I would highly recommend that you read The Order Of Time by Carlo Rovelli. It is so far my favourite book about how time technically doesn't exist and will lead you down a rabbit hole of further reading. Pretty easily digestible too, considering the subject URL_0",
"Asking two different physicists what time is and how it works is like asking a Hindu priest and a Presbyterian minister what \"God\" is and how god works. Both have probably spent a lifetime studying and thinking about that very question. They have very thought-through ideas about it that many many others believe as well. They may really believe that they have the one true answer. But the truth is that no one knows for sure. That's not a very satisfying answer, but that's how it is. Here are the two ~~most~~ historically popular ideas: Imagine an ant on the floor of an elevator. The ant can move left, right, forward, backward--any direction it wants, but only on the floor. To the ant, the floor is the only thing that exists. The elevator is moving up at a constant speed, and has been moving in that direction and at that speed for the ant's entire existence, so the movement isn't something it feels or notices. The two main ideas say that 1. the elevator floor is rigid and flat. The rocks and loose change on the floor just sit on top of the tiles. If the ant moves 1 tile left as fast as it can, the elevator has gone the same fixed distance up as when the ant moves its fastest a tile forward, back, etc. 2. the elevator floor is spandex with tiles printed right on the fabric. The rocks and loose change on the floor stretch it out where they're sitting. Because the tiles aren't all the same size and shape when they're being stretched, if the ant moves its fastest one tile left, the elevator won't have gone the same distance up as if the ant had gone one tile right. How much the elevator has gone up while the ant moves across a single tile depends on if/how stretched that tile is. Time is the elevator shaft. Edit: Thanks for the award! Edit 2 to clarify: 1 is the classical way of considering time, and 2 is the more currently accepted theory, which is backed by a large body of scientific evidence.",
"Sean Carroll has a really great video on this. If you don't feel like sitting through an hour, search for Minkowski Diagrams. Lets think about a standard 2-D graph. Along the vertical axis you have time, along the horizontal axis you have distance. You can draw a line through any two points on this graph. That line will represent the relationship between space and time, also called velocity. The greater the angle of the the line, the greater the velocity, the faster you move through the time axis. The lower the angle of the line the lower the velocity, the more you move through space and less through time. It's not the most intuitive thing, but I hope this helps."
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|
[
"url"
] |
[
"url"
] |
|
lu6t69
|
How does a manual credit card machine work?
|
What the titles says. I mean I can imagine it creates a copy of the card with a paper but how is the money actually taken out?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gp4i9t6",
"gp4i4gi"
],
"text": [
"Way back when, those credit card charge slips were sent to credit card companies. Some bookkeeper would go through those slips, and remove the funds from their user's cards. Then, the credit card companies would deduct their merchant fees and cut checks to pay the various merchants. It could take some time.",
"The imprint acts as evidence the card was physically present even if the transaction itself wasn't submitted for authorization when it happened. The merchant would record the card imprint and accept the risk the cardholder didn't have funds to pay for the transaction, and then later contact their card processor and give them the information from the card."
],
"score": [
8,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lu8ftg
|
how come skiers don't break their legs?
|
How come skiers are able to do those long jumps where they stay in the air for a few seconds and land unscathed while a normal jump that lasts that long would probably break your leg?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gp4r62m",
"gp4rbvo",
"gp4wpsm"
],
"text": [
"Because when they land, they don't really stop. As the saying goes, \"it's not the fall that kills you, it's the sudden stop at the end.\" Ski jumps are set up so that there doesn't have to be a sudden stop. The landing slope is sloped downward at an angle almost as steep as the ski jumper is falling, so when they make contact with the ground, they don't have to absorb *all* their momentum with their legs all at once. If they made the same jump but there was just flat ground waiting for them below, then it would be a lot uglier.",
"They land on a downward slope so they don’t go from free fall to stopped so suddenly. They keep some of that movement energy as they keep sliding down instead of just absorbing all the energy with their legs.",
"The landing ramp is so steep it's nearly vertical at the point of landing. From the jumper's perspective the ground slowly rises up to meet you, and the jumper lands at a very shallow angle to the ground. Only after the landing does the down ramp level out, also gradually. [Here's a full ski jumping hill]( URL_0 ). The jumpers are landing halfway down that ramp, at the steepest part."
],
"score": [
38,
6,
5
],
"text_urls": [
[],
[],
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Lysg%C3%A5rd.JPG/800px-Lysg%C3%A5rd.JPG"
]
]
}
|
[
"url"
] |
[
"url"
] |
lu9m7j
|
What exactly is the "Great Filter" theory, and how does it work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gp57l4q",
"gp50cbh"
],
"text": [
"To explain the idea behind the Great Filter, I first have to tell you about the Fermi paradox. The idea was first brought up by Enrico Fermi, one of the scientist behind the creation of atomic bomb. Fermi pointed out that the universe was very, very big both in terms of size and age. There a re billions of stars in out galaxy alone and even if only a small fraction of them ever ended up developing intelligent life, there should be some intelligent civilization that had been around for a very long time and had enough time to visits every star in the galaxy. There are however no easily noticeable aliens around here. That means that something weird is going. Another physicist called Drake came up with a a way to quantify the problem. He basically summed up all the fractions involved. If only 1% of all stars in the galaxy have rocky planet and only 1% of those can support life and only 1% of those will develop life and only 1% of those will develop intelligent life and so on. Obviously we don't actually know the percentages but we can make guesses. If you multiply all those fractions and then multiply the tiny fraction that results with the number of stars in our galaxy that tells you if there should be spacefaring civilization out there. We are starting to get an idea of some of the numbers. We for example have found out in recent years that planets seem to be very common at least. One way to look at the whole problem is to imagine that to go from a star to an interstellar empire, the potential alien civilization needs to pass though a number of filters that take out some of them and allow others to pass. For example we might imagine that life is incredibly common but that the jump to intelligent life is really, really rare. So developing life would be a small filter that only diverts a small faction of candidates but developing intelligent life is a big one that stops most of them. Since there are no signs of an alien civilizations out there and from what we know about physics, it would be hard to hide evidence of one, we can imagine that at some point all potential alien civilizations pass though a number of filters that filter most of them out. It could either be a number of small filters that add up or a really big filter that catches almost all of them or a combination of those. We humans are already most of the way there to colonizing the galaxies. So it would be nice to assume that there was a great filter at some point in out past that we passed though successfully. It is a bit scary to imagine that a great filter is still ahead of us. The idea that plenty of alien civilizations make it to where we are now and almost all are killed of before they can reach Star Trek level of advancement is really scary. Since this whole thing first came up during the cold war, one of the popular filters proposed was that many advanced civilization kill themselves of with nuclear war or an equivalent. It seemed natural at that time to consider that a possibility. Currently people are eyeing some future tech that might go catastrophically wrong, like AI going skynet on us or nanobots going out of control or some bio engineered plague taking us all out. Those seem less likely scenarios. Especially the robot takeover suffers from the problem that if that was a common fate of civilizations we would expect to see interstellar robot empire out there in equal numbers to the biological ones they replaced. It only shifts the problem. There might be something ahead that we can't even think of yet that will kill us all. That is a really scary thought. Sci-fi writers have embraced this idea in various forms. A common theme is that one civilization came first didn't want any competition and thus periodically wipes out any civilization that reaches a certain point of advancement. It makes for good sci-fi but seems overly complicated to explain real life. (Why not wipe out all planets with life on them?) In any case as far as we know great filters are real. We don't know if we passed them all a long time when life first began on our planet and that life is extremely rare or when we first developed intelligence or when we avoided destroying ourselves with out technology (so far) or if there is something still waiting ahead that has a 99.9% chance of killing us all. Doing things like searching for extra-solar planets to see how common they are (apparently very), searching for signs of life on Mars and Venus (maybe) and looking at the history of life on our own planet and the intelligence of other animals gives us some clue to which numbers we should use for the stuff that may have filtered us out in the past. If everything we know of our past doesn't add up to a 1 in 100 billion chance, we may have to worry a bit more for our future.",
"The universe is huge. The observable universe, less so, but still quite huge. It's been around for quite some time. It is speculated that life probably existed before us. Why, then, have we not seen evidence of such life? We would expect to see evidence of any radio-using spacefaring life - especially a Kardashev-2 or -3 civilization. However, we don't see any. Why not? What barrier stands between primordial life and kardashev-2 civilization, which has prevented any alien race before us from reaching it? This barrier is 'the great filter'. It is possible that 'the great filter' is math, or language, or abstract thought, and we humans have already been lucky enough to pass it. It is possible that the great filter is nuclear weaponry, and we are still teetering on the edge of oblivion. It is possible that the great filter is something we have not yet discovered."
],
"score": [
21,
14
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
luap7l
|
Where do governments borrow money from?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gp5a9y2",
"gp5btqe"
],
"text": [
"It’s own citizens. You can buy government bonds. This is you loaning money to the government.",
"Debts by definition are real (why count them as debt otherwise) and repayable (or else they would be called gifts, donations or, in the case of governments, taxes). Debts can go \"bad\" ie when lenders start to believe they won't get paid back or if the borrower stops paying them back. In theory, governments can simply stop paying. Practically speaking, they won't unless it is completely a last resort. Writing it off would mean that the currency value drops by a lot. Not only the government but private citizens wouldn't be able to trade internationally, inflation would skyrocket, domestic production would be hurt. Goods like food and basic produce go into shortage, welfare stops, pensions are worthless etc. This commonly leads to the downfall of the government or, in worst case, lots of conflict and death."
],
"score": [
10,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lub5x2
|
Why do crumbs left in jars and spreads from toast not go moldy, while bread will go moldy by itself in a few days?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gp5ednu",
"gp5s97p"
],
"text": [
"Crumbs have enough surface area to completely dry out. My original comment wasn't long enough, so I will say that bread and cookies and the like have more moisture and less surface area.",
"Most spreads are *loaded* with sugar, and preservatives. Mold and bacteria have a hard time dealing with high concentrations of sugar, it's a natural preservative. Add some artificial preservative to that and it'll take a lot for it to go bad. If you immerse a breadcrumb into this, it'll absorb these preservatives."
],
"score": [
30,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lubmof
|
What exactly is autophagy?
|
I hear the word dropped left and right but I still cannot for the life of me just by context comprehend what it is exactly..
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp6rj3v"
],
"text": [
"Autophagy is when your body breaks down its own cells. This is often due to either starvation or to dispose of and recycle old cells."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lubua8
|
How inheritable is sexual orientation?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gp5k6ao",
"gp5oif7"
],
"text": [
"As far as we know, it isn't. There are a few genes which some researchers have suggested are *loosely* associated with what sexual orientation someone will turn out to be, but the correlation is weak and could easily have other explanations. It just seems to be some kind of developmental roulette game.",
"[... it’s important to point out that recruiting twins with different sexualities is extraordinarily difficult. Researchers estimate that just 0.012% of the population consists of a gay or bisexual person who happens to have an identical twin]( URL_0 )"
],
"score": [
19,
3
],
"text_urls": [
[],
[
"https://kinseyinstitute.org/news-events/news/2019-07-26-twins-sexual-orientation.php"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
luc5nh
|
Why does paper turn translucent when wet?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gp5mydh"
],
"text": [
"Opaque things (like dry paper) do not let light pass through. Transparent things (like glass or clean water) do let light pass through and the light stays “ordered” so you can see what’s on the other side. Translucent things are somewhere in between; they light light through, but disorders it, so you can’t see the things (or at least not as clearly as with transparent things). Paper becomes translucent because it is made of materials which are good at absorbing water, meaning there is quite a bit of water *right through* the paper once it is wet, giving a pathway for the light to travel. But there is still some plant material which makes up the paper, and the light gets scrambled a bit as it gets past this material so the wet paper isn’t completely see through."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
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