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ksxve7
|
Why was the sun green?
|
Physics
|
explainlikeimfive
|
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"You saw the Green Flash! Thats awesome! Its rare to see URL_0",
"It’s a very rare phenomenon called the “green flash”! It’s basically sunlight through water/atmosphere but before/after the rest of the sky is illuminated.",
"The Sun emits light at different frequencies/colors (think about a rainbow). Due to different atmosphere layers, you can see a green-ish \"rim\" on top of the Sun if you take a picture (obligatory: please don't stare at the sun). Under certain conditions, part of the atmosphere behaves like a magnifying lense and you can basically see the \"zoomed in\" green rim for a while at the of the rising Sun."
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[
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|
ksxxck
|
How does liquid turn into powder?
|
Chemistry
|
explainlikeimfive
|
{
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"giiud9a"
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"It depends entirely on what that liquid is made of. If we are talking salt water. Like extremely salty water, removing the water through evaporation will leave the salt Crystal's behind. This goes for any ionizing crystal, or salt in the chemistry sense that has been dissolved in water. The same thing applies to milk, the milk solids remain after the liquid has been evaporated."
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4
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"url"
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[
"url"
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|
ksy7iv
|
Why does the pupil expand?
|
I was looking in the mirror trying to determine my eye color and saw my pupil expanding, and it got me wondering, what causes the pupil to expand like this?
|
Biology
|
explainlikeimfive
|
{
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"Our eyes adjust the amount of light entering your eye by expanding the pupil. Too much light and you can damagedyour eye. Too little light and you can't see anything.",
"It expands to let more light into your eye, typically in response to being in a darker area or situation to help you see better in low light situations. It also does the same when you are in a state of high awareness such as being scared or excited. I think that we evolved with that trait because in high adrenaline 'fight or flight' situations it was historically more beneficial to get as much light onto the retina as possible to aid vision.",
"There are muscles in your eyes that will expand or contract the iris exposing more or less of the pupil. This is controlled by the amount of light that hits your retina."
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5,
3
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ksyktq
|
how the heck do you attach new organs inside the body?
|
I dont know much about surgery and stuff but I'm pretty sure you cant screw an organ into place, gorilla glue arteries together, or tape them together.
|
Biology
|
explainlikeimfive
|
{
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"text": [
"You are describing pretty much the procedure that is done when transplanting inn new organs. Just pack it in wherever it fits and attach the arteries and vains as well as any other connections and let the body do the rest. The human body is very robust and can handle a lot of damage. If tissue is cut it will regrow new tissue to connect it back together. Most organs can work even if nerves are being cut. Blood and nerves will be able to reconfigure itself if there are any damages or things move. And even though humans have not had organ transplant for most of our evolution the cells do not know this and will just work like it was any other type of damage.",
"You can actually sew nerves and vessels together! About attaching the organs: the insides of our body's are pretty tight packed spaces. I dont know for sure, but I'd say that it holds just because there is not much space for it to move anywhere.",
"It’s mostly stitching, but staples, glue or hardware are sometimes also used. Say you are transplanting a kidney. The kidneys sit inside a fatty pocket which helps keep the organ in place. So you put the kidney where the previous one was, then connect all the blood vessels and nerves using stitches (sometimes glue). Over time the body fuses the connection points and it stays there by itself. For bones it’s mostly screws and plates. You just need to make sure the fragments are placed correctly and the body will make sure they fuse back together. In intestinal surgery staples are often used to save time and reduce the risk of contamination. Glue works wonders on skin when it’s an area with low bleeding.",
"Mostly it's done with hours and hours worth of tiny stitches with thread that dissolves over time."
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"url"
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[
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ksym5b
|
Where does the urge to push an aching tooth come from and why does that pain feel good and bad at the same time?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"This comes from other things aswell and it's the bodies natural urge to try to force change to irritation on our bodies. When we do this it is a different kind of pain that distracts from the throbbing monotony of what was there initially, also when you inflict a certain amount of self harm the brain stresses out and can send adrenaline through your body, so you could be getting high on like a mild adrenaline rush",
"I suffer with chronic pain in my leg. Causing additional pain in the leg feels better for me as I feel in control of the pain. I was also told by a doctor it was because it released adrenaline which is a potent pain killer.",
"A loose tooth from the perspective of your body is just an open wound that can't heal. There is obvious advantage in an instinct to agitate a loose tooth to get it to fall out more quickly and let the healing process begin.",
"Well at least adding pressure on a painful spot will help because of gate-control theory of pain. Basically pain signal travels with one kind of neurons and pressure travels with other kind. In addition to this both pain and pressure neurons connect with an inhibitory interneuron. Pain neurons inhibit this inhibitory interneuron so all you feel is pain. But if you push the pressure neurons will activate inhibitory interneuron, which will inhibit the pain signal. This is why you feel less pain if you add pressure on the painful spot of your body.",
"FWIW worth there's a thick nerve in the bottom edge of your cheekbone next to where the jaw bone meets it that if pressed in completely blocks tooth pain. I discovered it when I had a particularly bad abscess. It completely stops the pain. It's like magic.",
"The pain signal and the pressure signal is sent down the same connection. The pressure signal supersedes the pain signal.",
"When I experience it, I feel like there's a counter-pressure element to it. The inflammation you have in your gums is being countered by the pressure of you pushing. And it probably gives you another sensation to focus on besides the pain.",
"I don't know but I found this out. Nerve pain is a bitch. It can be total fine standing up, then you lay your head down and all the blood in your head pools up in your gums and BAM...layed out throbbing pain and even morphine won't do shit. Only alcohol...literally getting drunk will sooth it. That or go to the dentist, but I got PTSD from them. Root canal last year sent me rehab I was drinking so much. ....don't tell you mother I told you this son."
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ksypup
|
How does dust accumulate in an electric fans blades while they’re constantly moving fast in a circular motion?
|
it’s really been getting on my nerves the amount of times i have to clean this thing, how do they stick and accumulate on a fast moving blade? i’d greatly appreciate a response!
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Hey, aerospace engineer here. There's a long complicated aerodynamic explanation but here's the short of it. ELI5: at the point where air meets the surface of the blade, the speed of the air is zero. Therefore, a piece of dust on the surface is not being blown anywhere. When you spin the blade through the air, it slams dust particles onto the blade, and those particles don't get blown anywhere. This is similar to why water accumulates on a windshield even though you're travelling at 60 mph. Edit: after talking it through with another reddit, I was off a bit. The airspeed is zero, but the horizontal forces is not. The likely cause for sticking is that the dust particles are not large enough for the air pressure to blow the dust off the fan. Perhaps there is an upper limit to the amount of dust that can accumulate, at which point the surface area is big enough for the forces to blow it off.",
"The blade that moves through the air tends to get an electrostatic charge and if can result in the dust getting attached to the blades a lot more than if there was no charge. The dust that accumulates tends to be very fine particles. Because the blades push the air around a lot of air will pass over the blades so the can accumulate dust faster rotation then stations for the simple reason there is more air and dust in contact with them when they rotate. The moment of air can remove stuff but stuff can still be stuck to a surface. There is a reason you need to clean cars even if they move fast through the air. Passenger jets tend to have windscreen wipers on the two forward-looking windows so you can remove water or anything ells that accumulate on them. If you fly through an insect swarm the will accumulate on the windows and another part of the aircraft.",
"Remember rubbing a balloon up against your hair as a kid and your hair would stick to the balloon? Your fan is the balloon and dust is the hair. As the fan spins, dust is attracted to the fan like hair on a balloon and sticks to it.",
"The air touching the blades isn’t moving. Kinda hard to conceive but YouTube wind tunnel testing with cars, they use smoke to test the aerodynamics. If you watch closely the smoke never actually touches the car, but moves ever so slightly above it. That small cushion of air is how it’s able to stay and stick",
"Static electricity happens when the fan blades travel through the air quickly and brush the air molecules to move them out of the way. These molecules will build up an electrical charge on the leading edge of your fan blade, which is why dust particles will collect and stick more to one side than the other. Because I was lazy to formulate the principle, I just copy pasted above from google search result"
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ksz5l2
|
Why is it Harder to Navigate a Dark Room With Your Eyes Closed?
|
Even when the room is pitch black and your eyes don't have enough time to adjust to the darkness, it seems like navigating a dark room is harder to do when your eyes are closed. Is there a reason for this? Is the thought of "I need eyes to see and therefore I am helpless with them closed" so hardwired into our subconscious that we just NEED them open?
|
Biology
|
explainlikeimfive
|
{
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"I suspect what you are alluding to is related to balance. Your vestibular system and visual system both feed information to your cerebellum to help coordinate and refine movement and balance. That is why it is harder to walk in a straight line with your eyes closed. I suspect even in the dark, you have some low detail vision of your near body position in space, which helps you coordinate your motion and balance through the room.",
"There are multiple vision centers in your brain that aren't necessarily consciously processed in the way we typically interpret our vision. IIRC, the visual cortex is divided into 6 major systems, each with their own subdivisions and purposes. What's always interested me is what's called \"blind sight\", which is effectively that you're describing here. That is, depending on the mechanism by which a blind person has lost their vision, they may still be receiving unconscious visual information that they are not necessarily aware is impacting their decision making. For example, there have been some pretty interesting experiments done where a blind individual is shown a pair of faces and asked to identify which face is angry and which is happy. Not only can certain individuals choose the correct face a statistically significant number of times in a given sample set, they can accurately identify the examples with something like 90% accuracy. There are also examples of blind participants' heart rates rising and falling when shown images of spiders and puppies, respectively. So, when your eyes are open in the dark, your brain is actually still working with information that you may not be consciously aware that you possess."
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[
"url"
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[
"url"
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kszgr7
|
] If he was just like any other guy out there in the silent film industry, how did Charlie Chaplin attain so much fame?
|
Other
|
explainlikeimfive
|
{
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"He wasn't just like any other guy. For starters, he was absolutely excellent at his physical comedy so that helped. But Charlie Chaplin funded, produced, and directed many of his own films. And he was an absolute perfectionist at it. For some scenes, he shot dozens or even hundreds of times until he was satisfied. He put a great amount of effort into putting together casts and crews of people who could get along to achieve excellence. And he wasn't afraid to fire anyone who compromised his vision. He was also an accomplished musician and scored his own movies when sound in film became possible. When you think of Charlie Chaplin, you think of the tramp, the popular bumbling character he developed. But he was a lot more than an actor, from his early film days onwards, he had a huge impact on the way movies and the movie industry developed. Simply put, Charlie Chaplin's career pretty shaped film making as we know it. He was at the forefront of film making innovation for the first half-century of the industry's history."
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7
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|
kszjex
|
With 60 frames per second being my gaming default; Why do movies running at 24 frames per second look smooth to me but I'm easily able to classify games running at 30 frames per second as stuttering and slow?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"1. Cameras in movies are stationary most of the time. Movies start feeling stuttery when there are rapid camera movements. This is sometimes nauseating for me. 2. Movies have accurate motion blur, which makes it harder to notice the individual frames. 3. The intervals between frames are consistent (~40ms). When you get 30 fps in-game, the frametimes fluctuate, making it look jittery. 4. You are in control of your camera in-game, so your brain knows what to expect when you move your mouse. When the image is stuttery, your brain doesn't get what it wants, so it feels unpleasant. This is not the case for movies."
],
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7
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[
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[
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kt010d
|
Why do we close our eyes when experiencing something painful?
|
When I experience a sudden pain or am anticipating something to hurt, if I close my eyes or squeeze them shut it seems to help. Why would this be the case?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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],
"text": [
"There's an experiment called the 'rubber hand illusion' where you shove your hand in a box, and in it's place you see a very obviously fake rubber hand. A confederate of the experiment strokes you hand and the rubber hand in the same way at the same time until you almost think you can feel the rubber hand, then they stab the rubber hand. You will recoil, you'll probably even feel a sharp pain in your real hand... and then it will go away. **Because you can see it - you feel a pain that's not even there.** I believe this phenomena underpins why we close our eyes as a pain response: **because if we see it, we feel it - the sight of an injury multiplies our experience of the sensation of injury** even if there is no injury."
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"score": [
9
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[
"url"
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[
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kt08va
|
Can someone explain to me why some USA residents are obsessed with god and bible?
|
Other
|
explainlikeimfive
|
{
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"text": [
"To understand this, you first need to comprehend just how big America is. It is friggin huge. 4 day road trip to get from one coast to the other, no stops. Before modern transport, small communities were very isolated. People could go weeks or months without any strangers in town. Those kinds of insulated communities put a lot of stock on tradition, especially in religion. During the Cold War, conservatives pushed religion as a defense against the godless, atheist communists. Patriotism and Christianity were permanently linked in the psyche of small town Americans. It’s much more complicated than that, but those are a few big reasons",
"People commenting about it only being a few religious people in the countryside are missing the point, its weird that you swear so much on the bible, that your politicians are expected to be Christian etc. In the UK if a politician talked about god they would probably lose a lot of respect not gain votes.",
"Religion is a method of control. It comes down to the same reason our public school system is a joke : the uneducated are easier to steamroll.",
"Same reason why any other religious group of people are about their own religion. And I guess any other belief, for that matter. If you can explain how/why it is you came to believe something, you'll know how others came to be in the same situation too."
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[
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|
kt13ih
|
Frequentist and Bayesian Statistics (and the difference)
|
Thank you!
|
Mathematics
|
explainlikeimfive
|
{
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"text": [
"It's kind of a finicky distinction. Let's say you get a revolver and a bunch of volunteers, and you have the volunteers play Russian roulette for a while. After 600 trigger pulls, as expected, you have 100 dead volunteers. Now, your next volunteer prepares to pull the trigger. What can you say about the expected outcome? **Bayesian answer:** We've learned that the chance of losing Russian roulette is 1/6. This volunteer has a 1/6 chance of dying and a 5/6 chance of surviving. **Frequentist answer:** Either there's a round in the top chamber, in which case the volunteer is going to die, or there's no round and they're going to survive. Which one it is was established when they seated the cylinder, so it's inappropriate to talk about a probability here. Just because we don't know doesn't mean the universe doesn't."
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5
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|
[
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[
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kt1c7u
|
What is happening inside a computer's CPU that causes it to generate so much heat?
|
Technology
|
explainlikeimfive
|
{
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"gij8v6y"
],
"text": [
"Thousands upon thousands of electrical signals every fraction of a second roar through the microscopic circuits of a CPU. Moving electrical signals cause heat due to material resistance. So, things get very hot and require some sort of cooling mechanism."
],
"score": [
8
],
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|
[
"url"
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[
"url"
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|
kt1w3e
|
How do we know that all snowflakes are different?
|
Earth Science
|
explainlikeimfive
|
{
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"text": [
"It's more of a mathematical certainty than a definitely proven physical fact. There are just so many ways for a snowflake to be created that the odds of two snowflakes crystalizing in the exact same way are so small as to not be considered.",
"There was a scientist named Kenneth libbrecht who collected individual snowflakes and observed their structure, noting each one was different. The reason snowflakes do this is because ice crystals are sensitive to temperature and the fluctuating temperature as they fall can lead to innumerable shapes to the point that finding two of the exact same kind is virtually impossible."
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6,
5
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[
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[
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|
kt28vq
|
How does my phone differentiate between knuckle and finger touches?
|
My phone turns on the flashlight with a doubletap and takes a screenshot with a doubletap of the knuckle. I know the technology is called FingerSense but how does it work within the hard- and software?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gijezi7"
],
"text": [
"FingerSense is a software-based solution that works using sensors many smart phones already have. It doesn't require any additional tech on top of those. For example, when you tap your phone with a knuckle, you cause more vibrations than when you touch it with a finger. FingerSense picks up on these by monitoring the device's accelerometer (\"movement detector\"), and hence can tell the difference."
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"score": [
11
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[
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[
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kt28y6
|
how come we know about blackholes with soo much detail ?
|
Other
|
explainlikeimfive
|
{
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"text": [
"The flippant answer is we don't. Everything that we know about black holes comes directly from general relativity and were initially studied as a curiosity and almost a cheat of the mathematics before such an object was observed. Since general relativity has been tested over the last century and holds up pretty well (I'd love to go into more detail about this if you're interested) we're fairly confident that what we know about black holes is true. However, some of the weirder properties, such as Hawking Radiation, have not been experimentally verified so it is possible that this is wrong.",
"The best theory of gravity we currently have is the Theory of General Relativity (GR). In GR, gravity is modeled not as a force, but as a curvature of spacetime. That is, GR is a geometrical theory of gravity. It is this framework that theoretically predicted black holes long before the empirical observations indicating their existence were found. However, many of the predictions of General Relativity, like gravitational waves or the paths of stars very close to the center of our galaxy, have been empirically verified since their formulation in the early 20th century. As many predictions of GR are exceptionally precise when compared to their later experimental verification, this lends credence to its description of black holes."
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12,
5
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[
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|
kt2xzv
|
How do antidepressants cause weight gain?
|
I take antidepressants for, you know, depression. And I always hear that antidepressants cause weight gain of some sort. How does a pill that’s supposed to help with something in the brain impact the weight of your whole body?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"Paxil is probably the worst offender. It has an effect like Benadryl (called an anticholinergic effect), which makes you want to eat more often.",
"Antidepressants (and other medications) can have an effect on your metabolism, even slowing it down by as much as a quarter. If you needed 2,000 calories a day before, you might need as little as 1500 while taking these types of medications. Since we need to burn about 500 calories extra a day to lose a pound a week, this can mean that if you don't change your diet around, you could be gaining up to a pound a week."
],
"score": [
5,
4
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|
[
"url"
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[
"url"
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kt30nl
|
how people die in their sleep
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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"gijkdm8",
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],
"text": [
"I dont know what you mean by how... Someone falls asleep and theyre heart stops before they wake up thats how",
"You know Jamal, from 92nd Street? This morning, he woke up dead!",
"Many people with illnesses (cancer and such) die slowly over a few hours with their breathing and consciousness drastically reduced for that time period. At the time of death often these people will be unconscious/sleeping beforehand due to drugs/their body already shutting down. Things like heart attacks often happen whilst sleeping too, with the person not having chance to wake up within the space that a person would feel the heart attack happening and the time it would take to render them unconscious. Death whilst sleeping is honestly probably the kindest and most humane way to go."
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11,
6,
6
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[
"url"
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[
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|
kt362i
|
What is a laser "made of"?
|
What is exactly a cutting laser (meaning the lasers used to cut stuff). What is it "made of" is we could say so and how does it work?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Laser stands for light amplification by stimulated emission of radiation The beam itself is literally made of light. With regards to a cutting laser, that light is focused and so intense that it melt, burns, or otherwise vaporizes what it hits. Have you ever burned an ant with a magnifying glass? It’s a similar concept but with laser light and more power. This might help for a little in depth background URL_0",
"Laser is \"just\" light generated in a particular way so the beam is very \"tight\" (*coherent*). So it's basically just light. This is true for any kind of laser, not just the cutting ones (although the way light is produced may be different)."
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10,
4
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"https://www.explainthatstuff.com/lasers.html"
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|
[
"url"
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[
"url"
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kt3c5j
|
How does my car's A/C work for years and years - where does the burnt Freon (or whatever) go?
|
I have a five year old sedan, and the a/c has always worked fine. How can you burn Freon and not run out? I suppose this applies to refrigerators and all a/c's as well.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"Freon doesn’t burn. The heat (or energy) in the cabin air in your car is used to convert the Freon into a gas, so the heat is pulled out of the air making it feel cooler. The Freon is then condensed outside the cabin of your car. Condensing the Freon from a gas to a liquid pulls the heat out, and the AC dumps that heat into the atmosphere outside the cabin of your car. Freon is in a continual loop from gas to liquid. If your AC has a small leak in the loop, you can lose Freon over time.",
"Freon isn’t burning... It’s meant to be a closed system. The goal is that you want to move heat from one place to another... in the case of refrigeration, you want the heat from inside the compartment to move to the outside. To do this you need freon to evaporate, evaporation removes heat, this is why we sweat. The evaporated from then travels in a loop to a place where it gets compressed and then condensed back into a liquid. This released heat into the atmosphere outside of the compartment. URL_0",
"It's a closed cycle. You're not burning the refrigerant. It just stays in there until your hoses leak, the compressor goes or you spring a leak elsewhere in the AC system. Refrigerants are funny things that take away a lot of heat when they change states, but are easy to compress back into a liquid. You boil the liquid in the place you want cool and move air over that. Then you compress the gas back to a liquid somewhere else where you can get rid of excess heat (under the hood). You're cool inside, while boiling crazy temperatures happen elsewhere. Actually burning real Freon is very dangerous... Don't do that. If you want to learn more, look up the ammonia refrigerant cycle for a really neat system that's easy to understand. Then start with R12/R134 type systems. Ammonia is how an RV refrigerator runs by burning propane. Literally heat becomes cold.",
"There’s no burning of the refrigerant. Your AC works the same way your fridge does - it’s a closed system that circulates the refrigerant between the compressor and the expander, carrying heat with it. The energy needed for the process comes from your car power source, not from the AC."
],
"score": [
18,
8,
5,
3
],
"text_urls": [
[],
[
"https://arronco.com/lexington/blog/how-air-conditioning-works"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kt3dbp
|
. Why does the body lose a lot of water so fast after drinking alcohol?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gijkc6q",
"gijldt9"
],
"text": [
"Because alcohol acts as a diuretic, signaling to your kidneys to work faster. So they do, filter more blood and extract more water (and with it other dissolved things) and you flush it out.",
"Alcohol is a diuretic . It removes the water at a rapid rate through your rénal system which is your bladder and kidneys.. very similar effects as taking a water pill."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kt4489
|
why can't full computer memory be used?
|
Say I have 16GB of Ram on my pc, it will say 16.0 GB (15.7 GB usable). The same occurs with permanent storage. Why is that?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gijp4uv",
"gijp61m"
],
"text": [
"It can be used, just not all by you. The computer needs to reserve parts for its own uses. As an example, some parts of the hard drive are used to tell the computer what's on the hard drive to begin with! Without that overhead stuff, the computer wouldn't be able to use the hard drive at all (or at least not in any way that was practical).",
"Some memory is reserved for the system, things like the OS and certain hardware. With storage it's a whole different story. Windows measures drive sizes in powers of two, i.e. 1 kilobyte = 1024 bytes, 1 megabyte = 1024 kilobytes, etc.(these are actually called ki*bi*bytes, me*bi*bytes and so on, but Windows doesn't use that terminology). Meanwhile, hard drive manufacturers use powers of 10, i.e. 1 kilobyte = 1000 bytes and so on. Because 1 terabyte is approximately 931 gibibytes, a 1 TB hard drive appears as \"only\" 931 GB."
],
"score": [
21,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kt4als
|
What are drivers?
|
I’ve recently had to update some drivers on my laptop and I’m struggling to grasp how updating software can make the hardware better, it’s still the same graphics card in the machine, why do I need to update it to make it work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gijq07x",
"gijqdld",
"gijq6gs",
"gijqqbt"
],
"text": [
"Drivers are how we instruct an operating system to talk with a specific device that is attached. Rather than the OS know how to talk to each and every possible piece of hardware (like, say, every printer ever), it knows how to talk to a printer driver. All printer drivers speak the same language to the OS, and then they will translate it into the appropriate language for the specific printer they're made for.",
"Think of drivers like actual drivers (of cars). The cars are your video card, and the roads are like CPU hardware. You are the driver. Lets say you've got a fancy new lamborghini (video card). You want to really see what this thing will do. Oh, and we're in a place you've never been before... If you or I (drivers v1.0) were to drive it, we'd probably be able to get from point A to B, but since we're not race car drivers, we're going to stall, and probably get lost. We'll work, but not optimally. Lets say we get a map of our locale and try again (drivers v1.1) We can improve our knowledge of our surroundings, plus we have some experience from our first trip... We do a little better. Now, we hire the Stig, and find out that he grew up just around the corner! (drivers v2.0) He knows the area, he knows the car (because he's an expert at both), so everything will work more smoothly. Does that make sense?",
"> it’s still the same graphics card in the machine, why do I need to update it to make it work? First, like every software also drivers have their own bugs, so updating can fix bugs (if the new version fixed those bugs, that is). Second, new driver version can increase performance if they run some math (remember, everything really boils down to math) in a more optimized way.",
"Drivers is what let's your system talk to your hardware. Generally, when you update your driver's, it should improve/simplify how your computer talks to the hardware allowing it to work better. It should be like going from \"it does not\" to \"it doesn't\" which should help it work better. Sometimes though, it doesn't understand how it works which can make it worse. Think of it of as explaining colloquial words to a person that has English as their 2nd language. Sometimes they get it and pick up easily and helps them understand English better. Sometimes they don't understand it and don't use it properly."
],
"score": [
16,
12,
6,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kt4kqa
|
How can traders trade commodities that they don't actually physically own?
|
When I see these YouTube adds for trading apps, I always see how people trade commodities. But let's say I trade wheat. How does that work without me actually owning the wheat? Is the physical equivalent to all those trades exiting somewhere?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gijsqxs",
"gijt47o"
],
"text": [
"You don't actually trade wheat. You trade the right to buy wheat. Basically there is a contract that says \"I will sell 2,000lb of wheat to the owner of this contract on Feb 7 2021\" You buy this contract today for 500$ hoping that on Feb 1 2,000lb of wheat will be worth 600$ you then sell the contract to some one who actually wants 2,000lb of wheat on Feb 1 and pocket the 100$. The person who buys the contract from you for 600$ is paying for the last minute buy. They may not know how much wheat they will need until Feb 1, Or they were betting that wheat would only be 400$ in Feb and they were wrong.",
"You are trading futures contracts, which is the future possession of the commodity. You aren't trading 10 tons of corn, you're trading the right to buy 10 tons of corn at $1000/ton deliverable on Mar 31. Whoever actually owns the contract on Mar 31 gets the delivery of corn."
],
"score": [
20,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kt4ltv
|
how do projectors make the color black on white screens?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gijrmmp",
"gijryah",
"gijsjg4",
"gijt2i0",
"gijt31l"
],
"text": [
"They don't really, they just don't shine any light at that area. That means that the \"black\" will be the same color as the screen, which is why projectors only really work in dark rooms.",
"They don't - it is impossible for a projector to make a surface darker, only lighter. The projectors get around this by primarily being used in dark rooms and projecting on special materials that help to isolate and direct light. They also take advantage of a little quirk in our brains where the perceived lightness/darkness of a surface is impacted by the surrounding areas. We've all seen the [shadow illusion]( URL_0 ) where squares A and B are actually the same color, but our brain sees them as different because of the surrounding colors. Thanks to this, something can appear 'black' on a projector, despite the fact that it is actually just the color of the projector screen.",
"They don’t. Projectors work by projecting mixtures of light to make colors. White is a combination of all the light colors and black is the absence of all light. So in an image with black portions, no light gets projected to those parts. A plain white screen is not a very good choice for projected images. What you really want is something that can reflect light very well when hit with light but otherwise will remain dark. This is why projectors work best in darkened rooms and we used to use silver screens to project to. So basically the more light in the room and the lighter the screen you have, the more washed out looking and overall bright looking will be your projected image.",
"It does not. Black will be the absence of any light from the projector so it will have the same color as the surface you project on. So you need a projector that emits a lot of light so the areas around it look a lot brighter and you see the unlit white areas as a lot darker. Grey as a color is white with less light intensity compared to the surrounding. Look at [this image.]( URL_0 ) square A and B have the same color but you think of A as gray and B as white because of the surrounding areas and the shading you see from the green object. If you open it in an image editor and pick the color they are the same, you can do the same by cutting holes in a paper so you only see those squares. So human vision is based on the light relative to the surrounding not the absolute amount of light The dark color in a projected image in a well-lit room will look washed because they are a lot brighter because of light that does not come from the projector There is a reason that in a cinema you turn the light off in the theater so very little light hits the area that should be black.",
"A projector can not make the screen any darker then the ambient light in the room does. However your eyes are already used to this and will only perceive relative light levels. So when seeing the screen in both light and dark white we automatically interpret the darker areas as black even though it is actually fairly bright."
],
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86,
29,
6,
5,
3
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Checker_shadow_illusion#/media/File:Checker_shadow_illusion.svg"
],
[],
[
"https://en.wikipedia.org/wiki/Checker_shadow_illusion#/media/File:Checker_shadow_illusion.svg"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kt5rss
|
Why is 16:9 the desired TV resolution scale, and why did it replace 4:3?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gijzuma",
"gik17dh"
],
"text": [
"Turns out there isn't really a standard and there's not a great reason for what we have! No expert but I did just happen to watch Captain Disillusion's youtube video on just this topic. I'd recommend watching it [ URL_0 ]( URL_0 )",
"16:9 is not a resolution but an aspect ratio. It describes the with vs height of the screen regardless of the number of pixels. For example, 1080P is 1920x1080 and 4K for TV is 3840x2160 both use 16:9 even if the resolution is not the same. 4K has 4x the number of pixels 16:9 (1.777:1) is the geometric mean of 4:3 (1.333...:1) that older TV use and the 2.35:1 that was the most common move aspect ratio. So sqrt(1.333...\\*2.35) = 1.770 and it was changed to the close integer ration 16:9 The reason it was chosen to minimize the number of black bars on the side for old 4:3 TV and bars on top and bottom for movies. You have to remember that when widescreen TV started to be sold most TV would be in 4:3 so it would be used for that a lot. if 2.35:1 was used old TV would only be half the with of the new TV and is harder for people to pay a lot for a new TV when only half the screen would be used for TV. The 16:9 format was first used in analog TV and the digital TV standard later adopted it."
],
"score": [
8,
7
],
"text_urls": [
[
"https://youtube.com/watch?v=g5ZgUIobSj0&feature=share"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kt5w5d
|
Why does it hurt when you put on deodorant after shaving?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gijzcfn"
],
"text": [
"Same thing with after shave there are micro cuts then when something gets in the cut it stings"
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kt5x2u
|
How does sound transfer from my ear to my brain?
|
If I were to cut off my ear and hold a speaker up to the hole, would my brain still hear the noise? Why/why not?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gik05a6"
],
"text": [
"Yes, the sound would transer. Your outer ear is just a funnel to help channel sound to your ear drum. Sound is waves of vabrations in the air. Something moves in air. The air gets pushed. That push travels like ripples in a pond. That's what sound is. These ripples in air pressure are captured by your ear drum. It's a wall of sensitive tissue that itself vibates from the impact of sound. That drumhead of tissue is connected a chain of small bones that transfer the vibrations to nerve endings. these nerve endings have different sensitivities and activate based on different types of stimulus. Based on which nerve endings are activated, signals are sent to the brain, which then interprets the data as the experience you have of sound."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kt5zpo
|
What is the difference between a compiler and an interpreter? Why use one over the other?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gik4pic",
"gik14ym"
],
"text": [
"Imagine you're vacationing in France, but you don't speak any French. You want to visit the Eiffel Tower today, and your hotel concierge has written down the directions to get there, but they're in French. You can solve this 2 ways. Your bilingual friend can read the French instructions, figure out what they mean, and then write them down for you in English. Now you've got a list of directions written in your native language, and you have everything you need to go on the trip alone. In this case, your friend has acted as a compiler. OR, your bilingual friend can come along with you, and can read the French directions with you and explain what each instruction means as you go. In this case, your friend is an interpreter. The compiler approach is much more lightweight, because you only have to bring your translated directions with you, and not an entire person. It may also be faster in carrying the instructions out, because you can just follow the directions one after another without having to stop and discuss each one. The interpreter approach is not as streamlined, but potentially a little more flexible. If it turns out there are some errors in the directions and you end up going down the wrong road, an interpreter *might* be able to help you figure out where you went wrong and get back on track, whereas if you encounter an error in your translated English instructions, you're pretty much high and dry, and you have no choice but to terminate your excursion then and there.",
"Compilers and interpreters both serve the same basic role: translating a computer programming language that's easy for humans to reason about into a language that's easy for computers to reason about. The difference between them is that a compiler performs that translation all at once, taking in a human readable program and spitting out one that a computer can (more easily) execute. Interpreters perform the translation at runtime, as needed. The biggest tradeoff here is that a compiler takes (potentially) a long time to perform the entire translation, but then when it comes time to run the program there's no translation work needed so the program can be very fast. The compiler also reasons about the whole program at once and can be set up to spend more time optimizing the resulting code, further increasing speed. An interpreted language doesn't need that compilation step so it can be very fast to iterate on, but they tend to be slower. Also, you can have different interpreters for different systems, so it can be easier to make a program that can work on lots of different hardware. Often a program will go through both a compiler and interpreter. The classic example of this is Java, which goes through a compilation step from the original human readable source code to an intermediate \"bytecode,\" then at runtime there's an interpreter (the Java runtime environment) that turns that bytecode into the actual instructions. More broadly, though, even compiled languages like C and C++ generally get compiled down to assembly. That is still one step above the actual ones and zeroes of a processor's execution, so processors run a basic interpreter to carry out the assembly instructions (see: \"microcode\"). Smaller microcontrollers may omit this step, storing the assembly instructions in a format that is directly digestible by the hardware itself."
],
"score": [
9,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kt60pk
|
You're not supposed to defrost meats in warm water due to harmful bacteria growth, you're not supposed to leave food at room temperature for long without being refrigerated because of harmful growth but, when you go to a buffet, food can sit out for hours under heat lamps and be fine?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"There's a concept in food safety called the \"danger zone\". It extends from about 40 F / 5 C to about 140 F / 60 C. You can keep food below the lower end of that range, or above the upper end, for a while without it going bad. The reason is that this is approximately the range of temperatures that the bacteria that cause foodborne illness can tolerate well enough to grow. They can survive in lower temps, but they won't grow or will grow very slowly, which is why you can store meat in the fridge for a few days without problems. (They'll die at higher temps if they're kept that hot for a while, as in sous vide cooking, but can survive brief exposure.) The food at the buffet is (at least supposed to be) kept above 140 F / 60 C, so that whatever bacteria may be present can't grow effectively. The trays at a buffet usually sit above a pool of very hot water in addition to the heat lamps, which keeps them hot. (This is if the food does stay out for hours. It may simply be changed out regularly, in which case it can be kept in the danger zone.) You can take the \"keep it above the upper end of the range\" principle really far, because temps above 140 F / 60 C will kill almost all bacteria with prolonged exposure. This is the principle behind [perpetual stews]( URL_0 ), foods which were effectively cooked for years or decades.",
"Also it should be noted, most health regulation not only requires you keep buffet food in a certain temperature range, But they also don't let you take food \"exposed to the public\" back into the kitchen. Nor do they allow you to have food in display for longer than a set time (even in a good range) - at least that's the rules we have in Canada.",
"In addition to what everyone else is saying about the temperature danger zone, food also needs to be at that temp for a few hours before it has enough chance to grow enough bacteria to be considered unsafe. If a buffet goes through food fast enough it’s safe as long as they ensure they throw out any food that’s been out too long. But defrosting meat often takes quite a while which is why it’s particularly dangerous to do incorrectly.",
"The first one is kind of an old wives tale and isn't backed up by science, except in the case of particularly thick cuts where it will take a very long time to thaw the inside with hot water, keeping the outside in the \"danger zone\" for long enough for notable bacteria growth to happen. Here's [an actual study on the matter]( URL_0 ) and here's [a more reader-friendly article.]( URL_1 ). When you're talking about food at home, you'd likely be perfectly fine if you cooked some food, left it out at room temperature for an hour or two and then finished eating it. That being said, the advice tends to take into account that you're likely going to put it back in the fridge, warm it up again, and consume more later - potentially multiple times. This gives way more opportunity for bacteria growth later. With a buffet, you cook the food which kills everything, set it out and keep it warm (some stuff like meat might be kept warm enough to slow down but not completely stop bacteria growth), and then either the entire thing is eaten over a few hours or it's discarded.",
"Microbial growth can be slowed either by keeping food cold or hot, but the range around 41-140 °F is generally considered unacceptable for controlling the growth of pathogens.",
"Keep in mind that the salad bar is usually the biggest source of food borne illness at buffets.",
"Ive always wondered as well, why does it matter if some bacteria grows when we thaw meat under water. If we cook it, does it not eliminate all the harmful bacteria?",
"Okay five year old explanation. Very cold: freeze and die like you would in Siberia in winter with no coat. Very hot: overheat and die like a person left in a car on a sunny, summer day in Pheonix, AZ. In between: live and prosper. Bacteria are like you. Too hot: die; too cold: die.",
"Just one thing to point out is that people get food poisoning from buffets all the time. The food handling guidelines are well grounded and backed by science, and when the food is handled appropriately (see the other posts), the risk is very low. But it's often mishandled, and that's why people get sick at restaurants and especially buffets.",
"As a former restaurant manager, I'd bet $100 that food poisoning is much more common in (especially cheap American) buffets than people realize. Most food poisoning is relatively low-grade in nature, meaning that instead of getting sick to the point of death you merely feel the urge to race to the nearest toilet a short while after eating. It's a form of harm but your body mostly handles it unless you're immunocompromised in some fashion.",
"Chefs are required to have a much better understanding of how food go bad and are therefore able to follow different rules then what you are advised to at home. The big difference in a buffet and whan thawing out meats at home is that in the buffet the meat is cooked beforehand. This kills all the bacteria so that it takes a lot longer for any new infections to populate the meat. However if you do it to raw meat it have already spent a lot of time at room temperature since the animal was butchered as a lot of the meat processing takes place above room temperature. So it already have a high population of bacteria and fungi on it, although not toxic levels. But leaving it out on the counter even longer may cause it to go bad. The advice you get about how to avoid spoiling food is also erring on the side of causion. Meat will not go bad immediatly as you put it in warm water but you should try to avoid leaving it thawed for long periods of time. A lot of people might be tempted to get meat from the freezer in the morning and either put it in warm water or just leave it on the counter so that it will be thawed when they get home from work which is obviously a bad idea. They might also be tempted to thaw some meat and cut a portion off it before freezing it again and doing this multiple times. Do not think so much about the rules themselves but rather just try to avoid doing anything stupid.",
"Ground meat needs special attention and care. But any kind of solid meat is fairly easy to avoid food poisoning. Rinse, and cook enough to sterilize by the process of cooking. I freeze meat in the package it comes in, or I break down a large pack into smaller zip locks before freezing. I defrost the bag in cold water, then cook. Been doing something similar for decades.",
"A huge amount of this is people not properly understanding what food safety guidelines mean and are for, by the way. Food safety guidelines were not written for your house, they were written for restaurants. A restaurant kitchen is chaos and it's filled with both people and food and all sorts of other stuff. They serve tons of people. You serve yourself and your family and maybe friends. a restaurant sized cut of frozen meat is often 10+ pounds. You almost never have that much meat to thaw. So if you take out a steak (even a big one) and put in on a safe place on your counter, it will mostly me fine to thaw there. It won't take that long and anything that might grow on it will be killed by the fact that you're cooking it (as things will only really grow on the outside). A restaurant can't make those assumptions (for starters because they often have whole cuts of meat that might take many hours or even days to thaw even at room temperature. Think of how long it takes to really thaw a turkey). in reality, bacterial growth on food is MORE dangerous after you've cooked it for most things. Because then you just eat it. Think of the heat maps at the buffet as the equivalent of keeping things warm in the oven at home. Also bear in mind that at a buffet (in theory, but not always in practice) the foot gets cycled out. Bad stuff like bacteria, fungus, etc takes a while to take root in meat. At home you rarely ever run into this (unless you're in college and leave pizza out on the counter for days) but in a buffet tons of people are eating that food. If you watch you'll likely see new food coming out regularly. Sometimes the old stuff just goes in back and gets repurposed (which SHOULD include making it safe by way of more cooking) or get tossed when it's old, but in theory the food on a buffet should always be relatively fresh and safe because of the time as much as anything else.",
"Food Safety Microbiologist for a state regulatory agency here. 1.). The top post nailed it, and I’m very exited that so many people chimed in with correct info! 2.). As always, there are exceptions. Listeria monocytogenes (L. mono.) can grow - albeit slowly- under 40 degree refrigeration temps. So what about deli meat in a supermarket? They must have date marking in place to track when the package was first opened, and discard any remaining after 7 days. (L. mono. Is bad. Especially for the unborn. It has about a 25% fetal loss rate if the mother contracts it. The reason they tell expectant moms to avoid deli sandwiches.) 3.). I frequently reference Too Gun, Danger Zone and Kenny Loggins in a training PowerPoint I would give on the subject. I am thrilled there is a new Top Gun coming out so this remains relevant!",
"You can defrost meat by placing it in warm water as long as the frozen meat brings the water temp down to below 40F quickly. I do it all the time with no issues. I also check the temperature and ensure it's safe.",
"Ok. I live in AZ so these are AZ regulations that I know of. In general, if you're new to cooking, remember that 4 hours is key. Someone else talked about the thawing thing, and that can also be covered by the four-hour rule. If whatever you're thawing takes a really long time to thaw because it's a huge piece of meat like a whole turkey or ten gallons of chicken stock, then if you try to thaw it in warm water, the outside will be too warm for too long before the inside is thawed. If you want to thaw something like two 8oz steaks at home, then just make sure you have a timer set to check on it at one and two hours so you can get it back down to a safe temperature or cook it right away. **** THIS ADVICE IS FOR HOME COOKS ONLY. DON'T DO THIS IN RESTAURANTS. IT'S NOT OK ACCORDING TO THE HEALTH DEPARTMENT BECAUSE THE AMOUNT OF MEAT THAT WOULD NEED TO BE THAWED THIS WAY IS ALMOST ALWAYS AN UNSAFE AMOUNT, NUMBERING IN THE TENS OR TWENTIES OF POUNDS. **** Things usually can sit and be safe on a buffet for four hours, the same amount of time it's recommended that you leave food out at room temperature. Other buffet rules: 1) Hot food cannot be held hot for more than four hours. - Between the time it lives hot in the kitchen and hot on the buffet, it should probably not sit out on the buffet for more than two hours. 2) Cold food should not be on a cold line for more than four hours, even if it's in a cold table. 3) Once food goes out onto a buffet, it can't come back to the kitchen. 4) This is all more heavily regulated with covid-19, and if you're eating at a buffet that doesn't have an attendant filling your plate for you, then that's extremely gross and (I think?) Illegal. 5) A buffet that has a lot of people going through it every meal and is a chain will most likely keep logs as to how long food stays out on their lines. A lot of places will bring in outside inspectors that are harsher than health inspectors to make sure that they don't fail any actual health inspections. Note: If you're eating at a buffet and business is too slow to empty out the food pans in an hour or two, then maybe you want to reassess your patronage of that buffet.",
"Please go to the nearest Golden Corral, eat until you are full, and then come back and tell us you feel fine ... for science.",
"My mom thawed whole chickens out in a large pot of salted water on the kitchen counter. Funny how 5 kids lived to adulthood without food poisoning. All of us survived, amazing!",
"I think you’re confusing an unsubstantiated generalism (food can stay under heat lamps for hours) as being fact. The reality in food industry is the food is consumed and rotated far faster than you think.",
"Follow on question - how unsafe is it really to eat food left out in a home setting? For example pretty much every college student has eaten last night's pizza that sat out on the counter overnight. Maybe the pepperoni is a bit more stable due to curing, but chicken is notorious for bacteria growth and you never hear warnings about the dangers of cold bbq chicken bacon pizza.",
"Yea if the foods been sitting out for hours then you're at a really shit buffet, while all buffets are likely shit, you went to the worst one, but the salad dressings on the other hand are cool and probably sitting out for hours, that's what I'd be worried about.",
"What everyone else says here about the danger zone and regulations is correct but, if you're smart, you realize that many people don't give a fuck about their service industry jobs and you'll only trust buffets until you get for poisoning the first time. Source: i worked in the service industry for years and would starve before eating from a buffet that I am not managing.",
"They should be tossing food as it gets old. One of the Chinese Buffets by my house got busted with cockroaches living inside the buffet itself underneath all the pans. This happens every year at this location. The Golden Corral by my house got busted sticking entire carts full of full size baking sheets with meat on them outside of the back door next to the dumpster to defrost. They got busted doing this a couple times.",
"- Defrost under running cold water is better (like in a bowl, in a sink) - Buffet food is supposed to be maintained in heater or cooler device when served, outside \"Danger zone\" temperature - Business should keep a log of checked interval temperatures. - Food not being temperature controlled can be out for a max of four hours, then needs to be thrown out/replaced with properly temperature held food - Most professional food businesses hold stricter food safety protocols than the standard mandates",
"Just don’t eat at buffets. Seriously. Nine years ago I got hepatitis A from a buffet that I got dragged to by friends (the place was subsequently closed down). I’m apparently one of the less than 1/10th of one percent of people who get extremely ill from it, at least that’s what they told me way back at the beginning. I spent a week in the hospital, six months virtually bed ridden, two years wondering wtf was wrong with me, a dozen trips to Mayo Clinic, countless procedures, two operations, and a life long diagnosis of fibromyalgia. Yeah, fuck buffets, man. And fuck people who work with food but don’t follow safe handling and storage procedures.",
"Health inspector here: There are two main factors food safety practices that occur for food that are cooked. They are temperature and time. As other responses have said, the danger zone for exponential bacteria growth is 41°F to 140°F. If you keep your food outside of those food temperature range then your food is \"safe\". Now the fda food code allows you to hold refrigerated food up to 7 days but the food quality will go down drastically as time goes. Now there's also this thing called time as public health control. That allows you to cook your food to safe temperature and allow the food to cool down into your danger zone. Catch is, you need to throw away that food after 4 hours pass. Hope that clarified a bit.",
"They can’t really. For food safety, buffets either need to keep hot food very hot or cold food very cold. An exception is fresh produce which as long as it has been washed can sit out for long periods of time like it does at the grocery store. A well-run buffet will often swap the food out and dispose of the old food every few hours. They don’t do this all at once and instead swap individual dishes out. If they’re busy, they’re lucky enough to be able to do this as most the food is gone from any individual dish. But they still have to do it even if there is no business all day because that food is no longer safe under the regulations. So even more than a regular restaurant, a buffet will go under very quickly if it doesn’t get enough business because they can’t just cook on demand and still follow their business model. They really need a large volume of customers."
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kt68dg
|
Can all substances be in all 3 states of matter? If you heat up metal, it will melt, but is there a point where you heat it enough that it will become a gas? Same goes for every substance on earth
|
Basically the title. I know water can be solid, liquid, and gas, but does that apply to everything or just water?
|
Chemistry
|
explainlikeimfive
|
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"The answer is almost entirely \"yes\". Strictly speaking, heating and cooling alone won't do it - you may also have to change the pressure of the substance. Carbon dioxide, for example, goes straight from solid to gas at normal Earth pressures but does have a liquid state at higher pressures. (Water would show the same behavior at lower pressures, going right from ice to vapor without a liquid state. It does this on Mars, for example, which is why Mars has no liquid water on its surface despite (a) having tons of ice and (b) sometimes going well above freezing temp.) There are also chemicals that, under normal circumstances, will break down or react long before they reach a different state of matter (for example, wood will burn before it melts). But in principle, every substance has a [triple point]( URL_0 ) where the solid, gas, and liquid phases all meet and you can go through any of the three phases by changing temperature or pressure just a tiny bit. Very strictly speaking, I believe helium-4 is speculated, but not known, to have a solid form at high pressures. But that's a rare exception in a material that interacts in extremely unusual ways, at temperatures low enough for quantum-mechanical effects to be important (at which point \"liquid\" stops really being a good descriptor either, as it doesn't behave like a typical liquid).",
"Most substances can, and metal vapours are absolutely a thing that exists. However, some substances chemically change into other substances before they're able to melt or vapourise. A typical example is wood, which is a complex network of plant cell structures mostly composed of starches. If heated in an oxygen-free environment, it will [pyrolise]( URL_0 ), splitting into a mixture of multiple substances like water, trace minerals and elemental carbon. Those substances can all be made into gases with more heating, but they're no longer wood.",
"There's some substances with really big molecules, like paper and vulcanized rubber, and I think some with really fragile molecules like nitrogen triiodide, that won't melt no matter what you do. That's because when you melt something, it melting means all the molecules are shaking around so much that they can slide freely past each other without getting stuck or tangled. Big molecules like you find in paper are so hard to untangle to make them slide freely that they'll tear themselves apart first, and really fragile molecules like nitrogen triiodide will tear themselves apart if you so much as look at them funny. The pieces of torn apart molecules might leave as a gas or stay around as a liquid, depending on the temperature and pressure around them, but they're not the original substance, so it's impossible to make melted paper that will harden back into paper as it cools.",
"As people have said, some molecules (groups of atoms stuck together) will break apart from heat before melting or boiling But for pure elements (all the atoms of the periodic table), yes! All the metals have boiling points not just melting points. If you heat them past melting they will boil and become gases exactly like how water does. Even things like carbon have a boiling point, it's just very hot. You can look up boiling point tables if you're curious. Some metals need 1000s of degrees, others surprisingly little. The metals that are liquid at ~room temp (gallium and mercury have low melting point) also have low boiling points! As a result mercury liquid is always giving off vapour which is why its such a health hazard. The liquid on your skin is fine, breathing it isn't.",
"Fun fact...a metal in the gaseous state is a fume. Most of the time when the word fume is used, they should use glasses or vapors.",
"I think the only exception is Helium. Solids, liquids and gases are really about how well atoms stick together. Solids are like Velcro - once it’s stuck it’s very rigid. Liquids are like a bunch of those magnet balls - they are definitely connected but can be moved quite easily. Gases don’t even stick to one another in any meaningful way. Every single kind of bond gets weaker when you heat things up. Heat is just a fancy form of kinetic energy (movement). The more you move, the harder it is to grab you. That’s why *anything* becomes a gas at high enough temperatures. Some things don’t behave like that though. Dry ice goes straight from solid to gas through a process called sublimation. No liquid phase is possible. And Helium is even more special. See, these bonds that determine whether things are solid, liquid or gas are not all created equal. From strongest to weakest we have Ionic, Metallic, Covalent, and Van der waals. Ionic is where two (or more) atoms give some of their negative electrons to another atom. This means that the donor is now positively charged and the recipient is negatively charged. Thus, they are attracted to each other. A good example is salt. Covalent is similar, but it’s more like borrowing electrons. Water (H2O)is a great example. The electrons spend most of their time at the O and rarely visit the Hs. This means that the O js “partially negative” and the Hs are “partially positive”, so water can attract itself a good deal. Covalent bonds sound weaker and normally are, but materials like Kevlar use them because if some cool quirks. Metallic bonds are super complicated and metallurgists are still learning a lot about them. They’re not super important here though. That just leaves the Van der waals force. Essentially, electrons orbit around the nucleus - the core - of an atom. But they’re not everywhere at once. Wherever they ARE is negatively charged, and wherever they AREN’T is positively charged in comparison. It’s a teeny, tiny minuscule force of attraction though. Barely worth thinking about... UNLESS you’re an atom like Helium. An element completely incapable of metallic, covalent or Ionic bonds. And also has the least van der waals force of all atoms on account of being so small. Helium is so unattractive to itself, that even approaching absolutel zero - the coldest things can be - it still won’t become a solid.",
"Absolutely yes. Its called the Triple Point in physics/chemistry/thermodynamics. From Wikipedia: In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases of that substance coexist in thermodynamic equilibrium. It is that temperature and pressure at which the sublimation curve, fusion curve and the vaporisation curve meet.",
"it applies to lots of things, but for some things there may need to be certain conditions in order for it to happen. Like needing a vacuum It's called the triple point [** URL_3 ]( URL_0 ) the triple point of nitrogen demonstrated [ URL_1 ]( URL_2 )",
"Yup. Although for most materials I believe they break down into their atomic elements at high enough temperatures. Like as an example if you could theoretically super heat steel to a ridiculous level you'd end up with iron and carbon as gases. Which... I mean due to gases tendency to separate on account of density and weight. I don't know what the relative gaseous density of iron and carbon is. So maybe those gases would mix or become inter-mingled. In which case can you really say that it is carbon and iron gas, or would it collectively be steel gas? Like a mixture of oxygen and hydrogen collectively is known as \"bang gas\" or literal rocket fuel, so there is presidence for a mixture being collectively recognised as a gas. Someone please correct me if I'm wrong, my answer is based entirely off my own understanding of states of matter."
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[
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kt6mbg
|
How does rust work? Does chipping off rust remove the source material? Why would chipping the rust off be better for the structure? Wouldn’t it just add more material and therefore strengthen it overall?
|
Chemistry
|
explainlikeimfive
|
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"text": [
"The problem is, rust is a catalyst for more rust to form. So, if you leave the rust on there, it just hastens the demise of the good metal. Removing it stops that process and means you might actually save the structure for a while.",
"Rust isn't an addition to the base material- it's the metal itself corroding, so you're actually losing the structure as it turns into brittle, flaky chips. It happens when exposed metal binds with oxygen in air or water."
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|
[
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[
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|
kt6u3h
|
When we rinse fruits and vegetables, are we accomplishing anything?
|
If I rinse an apple in my sink under cold water for ten seconds with no soap (like lots of people do), am I just wasting water? Or would anything actually be cleaned off? This is so much less of a robust cleaning then we're told to do in other circumstances, like handwashing.
|
Biology
|
explainlikeimfive
|
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"You are most definetly accomplishing something. Cold water, assuming it is clean, generally rinse off dust and particles and the microbes associated with it, leaving much less for your eminent immune system to deal with. Soap? Does anyone use soap on their fruit and vegs?!? That sounds like a bad idea.",
"That type of cleaning is usually to remove any loose dirt or grime, not kill bacteria or remove serious dirt like you might find on potatoes.",
"You're rinsing off residual pesticides, as well as any dirt or dust that may still be on the surface."
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[
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[
"url"
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kt6vcj
|
what is it exactly that makes a pain sharp vs. dull?
|
Was trying to explain to my daughter and failing miserably.
|
Biology
|
explainlikeimfive
|
{
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"text": [
"A sharp pain is very intense but very local. It tells you something like \"This part of your finger right HERE has a cut on it. Cover it now!\" A dull pain is less intense but usually affects a wider area and for less clear reasons. It tells you \"Your finger is messed up somehow. Maybe use it less?\"",
"Not sure if this helps, but these two types of pain are carried by separate nerve bundles. The sharp pain right after an injury like a cut is due to fast traveling signals in A fibers. The burning, dull pain that comes on after is carried by C fibers, which send signals much more slowly. If you stub your toe you can really feel the difference. Immediately there will be a sting of pain, and a second or so later you’ll feel a deep burning. These are the two fiber types at work."
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6
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|
[
"url"
] |
[
"url"
] |
kt6zn9
|
how those "I'm not a robot" checks on websites work.
|
Technology
|
explainlikeimfive
|
{
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"text": [
"They're usually measuring how fast clicks happen and how the mouse is moving across the screen. A bot is usually programmed to \"snap\" or teleport instantly to the images or checkbox, and that's a giveaway that it's almost certainly not a human checking the box. Same thing if it just receives an instant click as soon as the box appears, since most people don't have that fast of a reaction time."
],
"score": [
3
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|
[
"url"
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[
"url"
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|
kt7chz
|
File type conversions
|
I was in the process of converting a .wav file to be used as a ringtone on my iPhone and the process struck me as odd. There were several conversions between the WAV and the m4r. I used an online conversion tool to convert to .aac, a separate process within iTunes to convert to .m4a then for the final step I was able to simply show the file extension and change .m4a to .m4r. My question is, why does one conversion require a converter tool while others allow just changing the extension yourself?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gik8lk5"
],
"text": [
"Changing the extension on a file doesn't change the file type. For instance, if you the extension on a picture file from .png to .jpg, it's still a .png file. When you go to open it, the software will recognize that it's a .png file and display it as such. But no conversion has happened. When you actually convert a file to a new format, you are changing how the information in the file is recorded (could be compressed, some information could be tossed out to save space at the expense of the quality of the image or audio file, etc.), and then how it is played back in the software."
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"score": [
7
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|
[
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[
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kt7thu
|
Why is it hard for us to get out of bed, but once we're awake its hard to go back to sleep?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"Newton's first law of motion - just kidding of course. It's actually for different reasons as far as we know. Not wanting to go to bed is called sleep procrastination, and not a lot of research has been done so far, but most of them do point towards self-discipline/self-control as a main reason (which is why not everyone has this problem) . It's not so much a question of 'not wanting to go to sleep' as it is a question of 'not wanting to stop what I'm doing'. Maybe you want to keep scrolling your phone, or feel like you didn't get enough time to do your hobby after work, etc. We just like to keep doing what makes us happy, and the happiness we have from keeping on doing what we're doing is much more tangible and attractive than the distant chore of having to go to bed. NOTE: there might be other reasons as well of course, for example: teenagers' circadean rhythm (when our body thinks a day starts and ends) shifts slightly later, meaning they're simple not as tired as we'd expect them to be at that hour, or when you are suffering from depression or mania, or compulsive worrying, everything gets really mangled up! As to waking up, well, perhaps you haven't slept enough or regularly enough in the past few days, or you had a bad night sleep and are still tired, or you have stayed in bed so often your body is simply not used to becoming active as soon as you're awake! But what if you're actually a perfectly disciplined sleeper and still can't get up? Well, assuming you aren't being tormented by stress, anxiety or depression, you might have a bit of a nutritional deficiency, such as vitamin D,... (in which case - as with all other medical and neurological reasons: go to a doctor!), may lack an overview of what your day will bring and don't see the point, or it might just be that we like the warmth and comfort of our beds. That's obviously far more preferable then the cold, violent postapocalyptic world we live in now, and that's something we all can understand. **TLDR;** we don't procrastinate sleep, we actually don't want to stop the activities we're engaged in, and having trouble waking up might be due to several medical issues, such as lacking a **regular** sleep pattern, vitamin D deficiency, anxiety,... But might also just be because you like to hold your SO/Teddy bear/both beneath a warm duvet. Edit:My advice: sleep regularly, get out of bed as soon as you wake up, exercise (a little bit) , eat (reasonably) healthy, take care of your mental health and perhaps ask your doctor for some vitamine D in winter. Edit2: spelling. Edit3: as requested: being 'too tired to sleep' is actually another way of saying you have (acute) sleep deprivation. Some time before you go to sleep, your body stops producing the hormones you need during the day (cortisol, adrenalin,... ) and starts cleaning things up while making other hormones to put your mind at ease (melatonin,...). But when your body finds itself being up past it's bed time, it produces even more of those daytime-hormones, because it's not sure what and how long its going to happen! But then you finally decide to turn in and your brain is left with all these exes active, stressy hormones, thinking \"well thanks for the heads-up, mate!\" and needs a lot longer to clean everything up before your brain can go to sleep.",
"I'm a middle school student, so it may not be great, but my recommendation is to get a better pillow (screw those fancy matresses), get a morning and evening routine (mine is to brush my teeth, 10 minutes of stretching/working out limbs, walk around my house 2x, like with a shoulder against the walls, to drink a glass of water, then to lay down in my bed with lights out until I fall asleep), also alternate between sleeping on your sides & back."
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[
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[
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|
kt8t3l
|
Why do breathing exercises always instruct you to breathe in through the nose but out through the mouth?
|
I've always wondered why so many breathing/anti-anxiety breathing techniques direct you to intake breath through the nose but exhale through the mouth. Wouldn't all breathing be the same?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"Breathing in through your nose has a lot of advantages, actually, as opposed to breathing in via the mouth. Here are some examples: 1. Hair and mucus in your nose filter out small particles and organisms in the air 2. The blood vessels in your nose warm the air that is flowing through it, allowing for easier diffusion 3. The nose moisturises the air, making it less dry Etc.",
"the nose is a filter, whereas the mouth lets in as much stuff as possible. So to filter the air efficiently breathin in throught the nose is the way you are supposed to."
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|
[
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[
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kt95us
|
Why have animals shrunk over time?
|
I have seen 2 posts today showing 4 fossilised armadillo's and a fossilised turtle that are huge compared with how they are today. Even dinosaur fossilised bones are humongous compared to humans. My question is, why have they drastically shrunk over time and how do we know they aren't an extinct species from a very long time ago?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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],
"text": [
"Not all of them have. The Blue Whale, alive today, is believed to be the largest animal to have ever lived. The main reason that many animals are smaller than their ancient counterparts is that the air today contains less oxygen than it did in the past. The Earth's atmosphere today is about 21% oxygen, but at points in the past it may have been as high as 35%. More oxygen makes it easier to sustain larger numbers of cells, particularly for creatures that lack lungs and circulatory systems to efficiently capture oxygen."
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[
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[
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kt9adr
|
How do sailboats travel at 2X+ wind speed?
|
Physics
|
explainlikeimfive
|
{
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"text": [
"They can only do that when they're pointed \"off\" the wind. They can't go directly downwind (in the direction of the wind) at more than 1x wind speed. But if you're going at an angle to the wind, the keel is acting like an underwater wing to \"translate\" sideways force on the boat into forward thrust. It's roughly like pinching a watermelon seed between your fingers. You \"squeeze\" the boat between the wind force (sail) and the water force (keel) and the boat \"squirts\" forward. Aerodynamically it gets kind of messy, but basically the sail takes the wind and turns it into force, and the hull geometry makes it really hard to go sideways (high drag) and really easy to go forwards (low drag). Even if you're going 2x windspeed, if you're going at an angle you still have wind over the sail, so you still have lift on the sail, so you can keep going. The faster you go the more the wind \"looks\" like it's coming from the front of the boat so there's a limit to how far you can take it.",
"A sail with the wind behind is pushed by the wind. It can only go as fast as the wind. But if you head toward the wind, you can use your sail like the wing of an airplane. As the wind passes by your sail it creates a force pushing your sail forward, just like the air pushes a wing up. Doing this, your speed is not limited to the speed of the wind and you can go faster than if the wind were behind you.",
"Sailboats do not move in the direction of the wind for this reason. If they were going in the wind direction they would at most be able to go the same speed (but not really). A sailboat actually goes the fastest perpendicular (across) to the wind (it's actually at an angle but I don't know it). This is because a sailboat does not catch wind like a parachute or a kite. It is actually a big wing, like an airplane but sticking straight up. Going across the wind means that it is always pushing on the boat whereas if it was going downwind the wind would push less as the boat gets closer to the wind speed. Because of the sail, the wind hits the boat at an angle. Like how a ramp can make a ball roll sideways though gravity only pulls down, the angle with the sail and wind will push the boat forwards."
],
"score": [
10,
7,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kt9nwp
|
What happens to shadows during a solar eclipse?
|
Does the eclipse affect how sunlight hits the ground?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"giknsy6"
],
"text": [
"They vanish. Or more properly, they're replaced with a \"ring\" of shadows produced by the diffuse light from the distant sky where the sun isn't fully eclipsed yet, in the same way that objects still have soft shadows on a cloudy day."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kt9yqi
|
Why is fast air colder?
|
Like when you stick your hand out of a window of a car, it’s colder the faster you go
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gikp5xv"
],
"text": [
"It isn't, but it *feels* colder because it blows away the layer of air next to your skin that has been warmed by your body heat. That same layer is also moistened by water evaporating off your skin, so the moving air is dryer and speeds evaporation (which cools your skin further)."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktabf6
|
People complain about the two party system so im wondering what the alternative solution is? How is a non-two party system possible? Wouldnt they just form two parties based on similar beliefs?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"giksy4f"
],
"text": [
"Literally most democracies in the world have a multiparty landscape. The important thing why US law isn't allowing it is the \"winner takes it all\"-style of voting. In many other countries, proportional representation is used instead at least to some extent - parties are getting seats in the parliament proportional to the amount of votes they get (so if your party gets 10% votes, you get 10% of the seats in the parliament). Usually, the government is then formed via a coalition of parties that together have over 50% of seats in the parliament - this is kind of a temporary alliance fixed by a \"coalition contract\" (situation in Germany) where the parties that are part of it find a common line (a compromise) for the expected decisions to make. Another option is to have the largest party forming the government without a majority in the parliament - this is usually not seen as desirable because it can make it harder for the parliament to make decisions happen: For every vote, the government needs to find a new majority in the parliament by seeking alliances and compromises with the other parties."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktbmuw
|
Why do fingers and toes get really hot after being exposed to the cold after a while?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gil0qn3"
],
"text": [
"Your body cuts off bloodflow to the extremities as you lose body heat in order to keep your core organs perfused with warm blood and minimize heat loss through the superficial blood vessels of the fingers and toes. This is achieved by contracting the muscles that line the walls of those blood vessels, restricting flow through them in a process known as vasoconstriction. However, after a period of time the opposite occurs- those muscles relax, allowing a surge of warm blood to once again circulate through your extremities. After a while, vasoconstriction repeats and the cycle starts over. It's known as the [Hunting Reaction]( URL_0 ). This is believed to be a protective mechanism to prevent us from injuring our cold-numbed extremities by periodically keeping them warmed up."
],
"score": [
4
],
"text_urls": [
[
"https://en.m.wikipedia.org/wiki/Hunting_reaction"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktbqll
|
why do some foods, like pickels, still come in a glass jar, but most beverages, like milk, have migrated to waxed paper or plastic containers?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gil6ybb",
"gil5qjj",
"gilaccr",
"gilz9zu"
],
"text": [
"As far as I know (as a chemistry major) glass is safer for storing acidic foods because acidity can ease the leaching of plastic toxic compounds (like epoxy resins) into the food and that's why many acidic foods are still sold in glass jars. But then again I have seen several brands of pickels sold in plastic containers, so maybe the amount of leaching is negligible or we have to sue the companies :D",
"I wonder if it's simply marketing.. pickles in a plastic bag doesn't look sexy but milk is such a necessity that shoppers may not mind getting it in a less attractive and thus cheaper form",
"Pickles in glass jars are cooked in the jar to make them shelf stable. Pickles in plastic jars are fresh and must be refrigerated. Milk is pasteurized before packaging, so it can be packed in whatever is cheapest and easiest to transport. Glass is heavy and thus more expensive to ship.",
"It is based on traditions and marketing. In eastern european contries you can often find pickles, beet roots and other pickled vegetables packed in plastic bags, they also have those in jars and cans. What surprised me, as I never saw it is sausages packed in jars, never seen it before I went to Germany. Since I am from Lithuania and every meat product is packed in plastic vacuum bags. A heard people from US is very surprised to see milk packed in plastic bags when they first visit eastern europe."
],
"score": [
14,
12,
12,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktbsrx
|
If you flew in a straight line towards Jupiter’s core does it actually have any ‘planet’ or is it literally just a giant ball o’gas?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gil1y7b"
],
"text": [
"Simply put, we do not know because the gas surrounding it is too thick for us to see beyond. Additionally, Pluto was downgraded on planetary status because there are still objects in its orbit around the sun, not because it's \"too small\". There is no size requirement for a planet, just that it has enough mass to have a nearly round shape. Pluto specifically is not gravitationally dominant enough along its orbit to pull other objects of size into a satellite orbit around itself, or down to the surface (alternatively to alter an objects path enough that it is thrown far away). Simply put there's a lot of other stuff that exists in Pluto's orbit, and that's why it is only considered a dwarf planet."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktc2ap
|
If I am to be cooking meats to the recommended temperatures that destroys (what I presume to be) all harmful bacteria, for example (165f for chicken), then why does it matter if I defrost frozen meat in warm water?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gil2umw"
],
"text": [
"The same reason rotten meat cooked to a \"safe\" temp still isn't safe to eat. Killing bacteria doesn't get rid of the toxins (read: poop) they created while they were alive."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktcfuu
|
Why does order in a relay race matter if every runner will run their same individual speed?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gil5kmz",
"gil5rw8"
],
"text": [
"Theres a few things to it, in relay races, runners have a area at the start/end of their stint to pass the batton, some runners will end up doing slightly longer distances, your first runner might not be as good at grabbing the batton so you can remove that possibility, and the last runner could be bad at handing off but if they are last thats not an issue. Another reason is psychological. If runner 1 has a bad stint and is behind, the other runners won't feel defeated instantly because they can push a little harder to claw back some distance",
"The first runner needs a more explosive takeoff than the others, since they start their leg standing still. The last runner doesn't need to pass a baton, so they should be a solid sprinter who just needs to run as fast as they can with no other tasks. There are set zones that the baton has to be passed in, so you want to ensure that process is as smooth as possible. For example, if one runner isn't quite as fast as another, you want them to hand off to a faster runner who will match their speed in the exchange area and be able to speed up afterwards."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktcxe9
|
Why/How/When did capes go out of fashion?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gilbral"
],
"text": [
"Capes are used to keep you dry and warm when outside. The main difference between a cape and a coat is that a coat have arms but a cape does not. This makes capes cheaper and could even be quickly fashioned from other things for example a sleeping blankets or tent canvas. However when we got a very advanced cloth industry the price of sowing on the arms became low enough that it did not make much practical difference. So people would rather spend the tiny bit of extra money on a coat rather then using a cape. One of the last uses of capes in high fashion was maybe when wearing clothes with fancy arms. If you stuck your arms inside a coat you might ruin your attire so people would instead wear capes. You might still see capes used in this way but quite often you would use a coat and just drape it over you like a cape to avoid ruining your outfit."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktczcn
|
Why does mint make your mouth chilly?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gilabmo"
],
"text": [
"Mint contains a chemical called menthol that stimulates the neurons in your body that are designed to detect cold. It's similar to how chili peppers feel \"hot\" by stimulating heat-sensitive neurons."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktd3nh
|
why do some animals have translucent skin? It doesn’t seem like an adaptation that would be a good defensive or offensive trait.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gildemk"
],
"text": [
"Why would they not have a translucent skin, the answer is that a nontranslucent(there is probably a different word for this) skin protects you from radiation and light. So for animals that spend most of their lives in darkness a nontranslucent skin doesn't offer any benefits. And in some cases it makes them harder to spot."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktdond
|
Why does a PC/Laptop continue to play music after unplugging headphones while a mobile pauses?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gilie36"
],
"text": [
"Because that is how the software is programmed. On Android there is a specific setting to pause when headphones are disconnected so you can turn it off if you wanted. I assume iPhone has a setting but maybe Apple doesn't think users would want that sort of control. The behavior makes more sense to be on by default for a phone where it's much more likely that you'll accidentally catch a headphone cord and accidentally unplug in public. Less likely to happen on a computer and less likely to be an issue if it does."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktdopv
|
Why do people look ugly when they take pictures with their front cameras?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gildkuj",
"gilgku5"
],
"text": [
"The cameras are usually of poorer quality than rear cameras but that's not the primary reason. The primary reason is front lens cameras are usually what we call wide angle cameras. This means they can see more around them (they are less \"zoomed in\") than the rear facing camera, because to fit an entire face and more into a selfie requires a wide field of view. Wide fields of view though are widely regarded to not look really flattering. [Here is an example of photos taken with various lenses showing you how this effect looks.]( URL_0 ). Note for iPhones, the front facing camera is closer to the first image and the primary rear camera is the second image, still a massive difference. This effect is slightly less worse as well if you take the photo from further away and zoom in. Selfies are taken close though because armspan.",
"Usually bad lighting combined with wide angle lens being too close because you can't take a photo of yourself further than arm's length without some sort of holder. It fucks up facial proportions. Also if you mean your own photos, you are not used to seeing yourself the same way other people do because you can only ever see your face as a mirror image in real life and that's what you are used to. Set your phone on a timer, take enough distance to the camera, plan the lighting and flip the image horizontally afterwards and you will be happy with it."
],
"score": [
6,
4
],
"text_urls": [
[
"https://s.yimg.com/hz/en_us/Finance/US_AFTP_SILICONALLEY_H_LIVE/This_GIF_shows_the_camera-3ab48100d06a32947f8a098c235af23a"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kte575
|
Why is over watering the easiest way to kill a houseplant, but you can propagate those same plants in straight water? Also hydroponics?
|
I was just starting some some cuttings from my pothos in water and thought it’s strange that they’ll survive in just water but perish w too much water in soil?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gilfr77"
],
"text": [
"Too much water in soil allows bacteria and mold to grow and kill the roots. Hydroponic systems keep the water moving to keep that from happening."
],
"score": [
13
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kteg7d
|
Why are our abdominal muscles split into sections or “packs” rather than being one smooth piece?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gillewr",
"giljb03"
],
"text": [
"The actual rectus abdominus muscle is one smooth piece. The 'pack' sections are caused by tendon-like tissue that runs over the top of it.",
"Each muscle can move independently allowing a wide range of motion. Muscles can only relax or contract, there's no nuance or flex. If the abdomen was a single muscle, you could sit up, but that's it. The separate muscles allow for different levels of contraction at different places, lateral motion, etc. Those different muscles allow for a lot of flexibility and options besides just bending at the waist."
],
"score": [
10,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktfdlr
|
Why can you feel awake and ready to go after only 3 hours of sleep but feel overtired and exhausted after sleeping for 10 hours?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gilrh58",
"gin3w7f"
],
"text": [
"Most people have a sleep cycle that’s around 90 minutes long, so sleeping for a multiple of this means that you wake up during the lightest part of the sleep cycle. Waking up from deep sleep is hard, and can leave you feeling sleepy for the rest of the day. Waking from light sleep is much easier, because your body is more awake. If I had the choice between eight hours sleep or seven & a half hours, I’d go for seven & a half.",
"Imagine being on a seesaw and an adult is on the other side helping you go up and down. It's easy to get out of the ride then you're at the \"down\" part and difficult to get out when you're at the \"up\" right? In this example, the seesaw is sleep, and each \"up\" and \"down\" takes around 90 minutes. Getting woken up at the wrong timing is like being made to get out of the seesaw while you're in the \"up\" part; it's not a good time :("
],
"score": [
23,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktfq7g
|
Mood Rings, How do they work?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gilqbos"
],
"text": [
"Mood rings are made with chemicals that change colors at different temperatures close to room temperature. The latent heat given off by your body will heat up the ring and cause it to change color. If you've ever seen novelty plastic cups that change color when you pour a warm or cold beverage into them, or those old novelty pencils that change color when you grip them, it's the same general principle. Whether or not they can read your \"mood\" is a bit of an open question. *A tiny bit*. They clearly don't do anything to indicate your actual mood. Though, if you're in a state of increased blood flow for whatever reason (stress, excitement, etc) you may cause the ring to heat up more than usual and thus cause it to become a different color. At best, a mood ring is a very cheap and inconsistent thermometer you wear on your finger."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktgne6
|
Why do cold temperatures cause a weaker immune system/make it easier to get sick?
|
I don't know if it actually causes a weaker immune system, I just assumed it did. Otherwise the title says it all. I could add for example why is leaving home early in the morning with wet hair, when it's cold outside, considered not good because you could get sick.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gim5gar",
"gim62ke"
],
"text": [
"It's a superstition that persists today. The ambient weather has nothing to do with your health. The reason we came to associate cold and flu with the cold weather is that the weather creates extremely hospitable conditions for their spread. It's the reason flu season overlaps with the fall/winter months. In the winter, humans tend to gather indoors in close proximity, sharing air and personal space. The cold, dry air also allows airborne viruses and pathogens to survive and remain infectious much longer outside the body. Because we observed this phenomenon long before microbiology could explain it, we came to ascribe these diseases to the cold weather itself, not the pathogens we spread.",
"It’s not the cold per say, it’s what it makes us do: stay indoors crowded with others. This increases transmission. A lack of sunlight in the winter months and being inside causes various levels of vitamin D deficiency for many people, making them be more susceptible to getting sick."
],
"score": [
13,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kthvvr
|
How come our brains can convince us that we know the lyrics to a song while listening to it, when we really don’t
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gim7wcf",
"gim9r8q",
"gimeot0"
],
"text": [
"I can't remember lyrics for shit by themselves, but the minute the song is playing. Boom, you'd think I spent my whole life memorizing the lyrics..... Only to forget them again the minute the song ends. I truly don't understand it",
"Did you ever do one of those tests where there are obvious errors or missing text and you can read it? Brains fill in details to establish continuity and “sense” of witnessed events. That is the reason that eye-witness testimony can be very certain, detailed and yet in error.",
"Memory usually relies on context. You see your grade 11 math teacher in class, you know who they are. You see them at the grocery store and you have no clue where you know them from. If you've heard a song many times, the lyrics are familiar to you. You can sing along while the song plays because all of the context is there to cue you along. If you try singing it by yourself, you're missing that context. Once you know the song really well, you can start playing it through in your head and singing along that way. Otherwise, you need to put in some work memorising it."
],
"score": [
12,
8,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktib85
|
How do flashing lights cause seizures?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimi5g9"
],
"text": [
"During a seizure, the brain is firing at an incredible rate, just all cylinders go, to no particular end. As opposed to say, schizophrenia where the brain may be overfiring, but still trying to make specific things happen like walking or talking, and is not trying to do literally everything all at once. Epileptic seizures is like trying to make a spaghetti by grabbing literally all the ingredients in your kitchen and throwing them in a pot in random amounts at random times. Strobe lights disorient everyone to some degree, and being disoriented makes your brain work harder as it tries to figure out wtf is going on. The disorienting effect of the strobe can stimulate the epileptic brain until the point where it starts running all cylinders on go. It can't figure out what's going on so it starts sending random signals like \"move ALL the muscles!\" without adding signals like \"keep your balance\". Strobe lights overstimulate and disorient an epileptic person so the brain just goes into panic mode like \"idk wtf is going just pull all the levers and push all the buttons!!!!! JUST KEEP DOING EVERYTHING I DONT KNOWWWW!!!!\" (to be clear, epilepsy isn't associated with anxiety disorders, and not all seizures involve convulsions)"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktigl2
|
How come pregnancy tests are most effectively done through urine?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gim8961",
"gim8bvi"
],
"text": [
"Blood tests are better, but urinanalysis can be done at home in the privacy of a woman's bathroom. Not to mention that getting blood out is harder and messier.",
"Pregnancy tests are most effectively done through blood draws. They take a draw and read pregnancy hormone levels and then take another one and make sure those levels are raising (meaning the pregnancy is taking). Are you asking how a urine pregnancy test works? It works most effectively with the first pee of the morning because that has the highest level of the measured “hcg”. It shows one line (the control line) if the test is working and then another line if it is positive and no other line if it is negative. Does this make sense?"
],
"score": [
5,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktivxw
|
What makes a AAA battery different from a AA battery other than it being smaller? What’s the actual difference ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gimbmtv"
],
"text": [
"It's like the difference between a 5 gallon gas can, and a 1 gallon. They store the same thing, which burns the same, one just holds more. That said, there are different battery chemistries with different characteristics. But those are all available in both sizes."
],
"score": [
15
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktizb8
|
Why is perpetual motion impossible? For example, can’t you just redirect some of the energy produced from a generator into keeping itself running?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gimbyh5",
"gimcez4",
"gimpbn3"
],
"text": [
"We always lose some energy in the process. It's sort of like going, \"Can I pour water from a bottle into a cup, then pour that water back into the bottle, and keep doing that forever?\" You could do it for a while, but eventually you are going to have some of that water evaporate, or spill some, and while it'd be only a few drops lost at a time, eventually you'd run out. Perpetual motion is sort of like that. 100% efficient energy conversion isn't possible with our current understanding of physics. So it'd be like \"I take 100% of the energy from the generator, but am only able to get 99% of that energy back into it to keep it running.\" You lose some energy as heat or light or friction or some other forms, and while you can be very efficient, after a while you will run out of energy that way.",
"A generator \"produces\" less energy than it uses... It's more like a \"Transformator\" rather than a \"generator\". Let's say you are using a diesel generator to produce electricity. Some of the diesel energy goes into electricity, but most of the energy is wasted in heat, sound, gases, etc. You could use some of the electricity to help keep the machine going but what's the point? You supposedly wants some electricity, why would you water electricity to produce less electricity? If you use a battery to power a dynamo to produce electricity you'll end with less energy than you started with. Same as the previous example, you lose energy in friction, heat, noise, etc. You can't even transmit electricity through cables without lose some of it.",
"I want to emphasize that generators do not create energy out of nowhere. Generators take existing energy (in the form of motion) and transform it into a different kind of energy (electricity). The total amount of energy does not increase. When the energy becomes electricity, it stops being motion, which means the generator *must* slow down."
],
"score": [
21,
6,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktj7fv
|
Why is it we can eat a meal til we are absolutely full and still somehow have room for something sweet?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimeirt"
],
"text": [
"My understanding of it is that it's an evolutionary adaptation that has stayed with us. When food wasn't as easy to come across, if you found something sweet (like fruit) it was guaranteed high calorie/high energy food that could keep you going for a bit longer. So if you came across something sweet, even if you were full already it made sense to eat it for the energy it'd give you. Because of this, over time we adapted to always being able to eat something sweet in order to increase our chances of survival. That's why there's always room for pudding!"
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktj9f6
|
What, exactly, is a skin tag?
|
How do they come about?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimidnm",
"gimif1s",
"ginhxf3"
],
"text": [
"They are small harmless skin tumors. Not really sure why they pop up, could be from friction (they appear in areas with skin folds like armpits). There could also be a genetic component to it or an infectious component (some infections cause tumors, it could be a lower risk subtype of HPV)",
"It’s when skin mutates in such a way that it begins to grow outwards instead of just maintaining the existing surface. Related to cancer, but not dangerous because it’s only growing new cells outside the existing ones, and doing so relatively slowly.",
"You can tie a cotton loop (think sewing thread) tightly around the base of a skin tag, put a plaster over it. Repeat daily, removing the plaster and replacing with fresh - you can add a new loop over the old cotton thread, no need to remove it. after 3-5 days the tag will fall off when you remove the plaster because it's had no bloodflow. I'm pretty sure that's a harmless way to remove them, done it a few times. Please do correct me if anyone knows better."
],
"score": [
30,
15,
13
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktjbz1
|
How are computers motivated in Q Learning?
|
I get that it uses a number going up and down depending on the behavior, but why does the computer/AI try to make the number go up?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gime1m2",
"gimeg8j"
],
"text": [
"The goal is to maximize the reward. It’s explicitly told that higher is better. Nearly all machine learning is centered around maximizing our minimizing some target.",
"Computers don't want, or care about, anything until we give them a program that tells them what to want/care about. (I'm anthropomorphizing computers here, obviously, but you get the point.) In machine learning, we give the computer a \"value function\" or a \"reward function\" that tells them how good a job they're doing, and then we tell them that their goal in life is to maximize that function. Once we tell them that, they go after it with everything they have. That's simply how programming works; if you write code that gets the machine to come up with some options, work out what the reward would be for each option and then choose the one with the highest reward, then assuming the computer's working correctly, that's what it will do."
],
"score": [
4,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktjirc
|
Why do the most interesting parts of our dreams only occur right before we wake up ?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimfm07"
],
"text": [
"I don't know that that's true. I don't think my experience matches that. I think what's very likely is that we just remember only the bits right before we wake up. I seem to recall learning that unlike conscious perception, dreaming doesn't go from short term to long term memory, except of course the bits we focus on when we're awake and they're still in our short term memory."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktjzku
|
Needing some information on how buying a car and getting insurance works in Alberta.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gimmjt3"
],
"text": [
"Do you have an idea of what kind of vehicle you want? Once you do, head to a dealership and do a test drive. You can do the entire purchase through a dealership at which point you call your insurance company and get the vehicle insured and then you go to a registry to get the vehicle registered. Back to the dealership to pick up and away you go. Hope that helps! You may want to shop around for insurance."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktk34o
|
Why does hitting your funny bone hurt so dang bad?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimjf7n",
"gimjcpb"
],
"text": [
"Because the ulnar nerve runs on the underside of the point of your elbow and is basically unprotected. It is the largest unprotected nerve in the human body and is responsible for the feeling in your pinky and half of your ring ringer. When you “hit your funny bone” you’re actually impacting this nerve.",
"Funny bone is actually a nerve so when you bang it up, you squish the nerve against the bone and that's what makes you feel so awful"
],
"score": [
6,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktk7tn
|
why are we told to breathe in through your nose and out through your mouth if all the oxygen gets in your blood stream in the lungs either way? Would it not be better to just breathe in and out of your mouth for the most oxygen?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimkclk",
"gimk9m0",
"gimpjgi",
"gimnyg9"
],
"text": [
"The nose warms, filters and moistens the air so that it’s ready for the lungs. The mouth just draws in air without warming, filtering or moistening the air. Breathing through your nose reduces the amount of dust and crud that gets in your lungs.",
"Your nose has air filters, it makes the air safe to take in, it's good at catching pathogens and stuff. Your mouth has enzymes and teeth, it turns food into mush, which your body turns into feul. So when you breath in through your nose, you filter it and make it safer, and when you exhale through your mouth, you push out all the co2.",
"I'm so used to breathing through my mouth, is this a habit that I can learn to stop doing? I feel like my nasal cavity is too restricted so I just use my mouth.",
"Breathing in through your nose is very important. \"Nitric oxide is produced in the paranasal sinuses and is excreted continuously into the nasal airways of humans\" I am no scientist but I read NO helps to modulate your breathing and absorb oxygen."
],
"score": [
60,
13,
5,
4
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktl0h3
|
What are VPNs and how do they work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gimq2qn"
],
"text": [
"VPNs are often described as tunnels, but they're a bit more like a secret code. Think of the internet as being like the postal service. When you visit a website, your computer is just exchanging letters with a server (a sort of special computer) somewhere that holds the information on the website. Your computer sends a data packet via your internet service provider (ISP) like giving the letter to a courier. The courier takes it to a sorting office. Another courier takes it to the website (using their ISP). But crucially, the address and your return address need to be on the envelope. This means both ISPs know who you're talking to. Say your ISP suddenly decided they didn't like Netflix. They could just refuse to deliver letters to them. (Unlikely, but technically possible.) Or maybe your government wants to know who you're talking to. They could just force the ISP to give them a list. Now, a VPN is like a private middleman. You and the VPN company share a secret password. You use this to encode messages. Instead of directly addressing your letter to Netflix, you address your encoded message to the VPN, and in the message you put in Netflix's address. The courier takes it to the VPN. They unscramble the message, and send it to Netflix *from the VPN*. This means it can't be traced back to you. Netflix get the message and reply to the VPN. The VPN knows it's for you, so they scramble it again and send it back to you, and you unscramble it. This way, your ISP doesn't know who you're talking to except from the VPN company. The other way this can work is that you use a university/work VPN. This way, you're sending your scrambled messages to work and back. Because they're more scrambled than usual, it's more secure so you're allowed to access more files etc. It's almost like you're directly plugged in to the network."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktl633
|
why is earths core so hot? Is it just because it “hasn’t cooled down yet“?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gimptkn"
],
"text": [
"The Earth's core was hot to start with. It has been slowly cooling, but a lot of heat is generated by radioactive elements in the core decaying. This has kept it hotter for much longer than the \"baked potato\" Earth simulation would predict."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktmrje
|
How does our body temperature stay the same (if we're not sick) even if we are in an especially warm or cold place? And when we are sick why does the temperature rising a couple degrees up or down make such a difference?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gimyxq4",
"gimyrfh"
],
"text": [
"The body has ways of regulating temperature. If it's cold, the body restricts blood flow to arms and legs where there's a lot of surface area for heat to escape. It can ramp up metabolism in order to just produce more internal heat. Shivering is your body spasming your muscles to generate heat. The primary way of cooling down is sweating. When sweat evaporates from your body, it takes a bit of heat with it. The reason we maintain the temperature is because the things our cells do keep us alive work best at this temperature. But, bacteria the get us sick also work best at this temperature. So changing the temperature can weaken the bacteria for immune system to kill. But this also messes with our own bodies which is why a fever feels so bad.",
"Our bodies go through a lot of trouble -- a *lot* -- to ensure our internal temperature stays as close to 98.6 F as possible. Our blood vessels change shape, we start to sweat, we even sacrifice our hands and feet to keep blood close to our core if things get bad. > And when we are sick why does the temperature rising a couple degrees up or down make such a difference? Chemistry is delicate, especially the chemistry of life. One, two, three degrees doesn't sound like a lot -- our conscious minds can't even tell the difference -- but on the scale of molecules, they're miles apart."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktmy9y
|
how is it possible for NASA to establish a signal/connections so far in outer space but we can't find signals in certain rooms in our homes?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gin39u5",
"gimzmgr",
"gimzq8f",
"gimzlrr"
],
"text": [
"Plenty of people have mentioned the difference of equipment, but the main factor is that electromagnetic waves transmit indefinitely through the vacuum of space, and without much, if any, interference. Your house is full of wood, metal, insulation, and plaster, which get in the way, and also cell phones, game controllers, a microwave oven and maybe a baby monitor that all emit similar signals.",
"Their instruments are significantly more sensitive and specialised than the mass-produced router with Wi-fi you got for free when you signed up for broadband. NASA will also have spent slightly more on their equipment (ie millions) than you.",
"Comparing NASA's [Deep Space Network]( URL_0 ) to commercial WIFI or cellular technology is comparing apples and oranges. NASA has a global network of gigantic (70m/230ft wide) radio telescopes that send and recieve powerful signals (up to 400 kilowatts) in narrow beams that must be carefully aimed, and their space probes likewise have gigantic antennae that send and recieve in one direction.",
"For example, NASA was able to maintain a connection with Curiosity Rover on Mars and receive images taken by it. Also the Cassini (I think it was called) took a photo of Earth so far away in the rings of Saturn and sent it back to Earth. How is this sort of connection possible? Are there satellites in outer space that are just really strong?"
],
"score": [
52,
14,
4,
4
],
"text_urls": [
[],
[],
[
"https://en.wikipedia.org/wiki/NASA_Deep_Space_Network"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktmzev
|
What does the specification chargers usually mean like Output: 5V=2A or 5V=6A MAX ?
|
I was looking at my One Plus Warp charger and I saw that the output says 2A or 6A at 5V. What does this exactly mean? Edit: I wanted to add some more info. When I charge my brother's mi phone(screen displays fast charging when I use mi charger at 5V and 3A) from my charger it doesn't show fast charging. So does the warp charger operate at 3A when it is charging the mi phone or at 2A?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gimzuee"
],
"text": [
"The V rating describes the voltage. For most systems, this should *perfectly* match the rating of the thing you charge. If your phone charges at five volts, you want a 5v charger. The Amp rating is a limit. Your device should not exceed the charger's maximum amperage (current). Most devices, like phones, will automatically adjust and so it is not an issue. Something like a computer monitor, however, may not be designed to do so, and so you must be more careful when choosing a power cable for such a device."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktn4dj
|
How does the making of cotton candy work?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gin0kws"
],
"text": [
"Sugar is heated in a spinning cylinder that has a series of small holes in it. As the sugar becomes a liquid, the spinning force send it out the holes. As it hits the air and is no longer being heated, it turns into a solid. This solid string of sugar is collected on a (usually paper) cone or stick so you can enjoy it."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktnajw
|
How do radtio/tv station know how many people are tuned in ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gin1k4m"
],
"text": [
"I was a panel member for Nielsen. They give a small percentage of the public a device (that looks like a pager) that tracks most media consumption through an inaudible tone that is broadcasted on radio, TV, etc. They then multiply the numbers and there you have your ratings!"
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktnkse
|
How did Parler become an alt platform, with the name being a French word?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gin3nol"
],
"text": [
"I’m sure that was not a mistake. It was created as a “free speech platform” due to some on the right believing they were being banned off of other social media platforms. Now whether this is true or not isn’t the question here, but it was at least advertised as such. “Free speech” being the term of the day, Parler makes sense as a name."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kto5a8
|
If we’re made entirely of atoms and atoms never touch how do we feel different textures/fabrics
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gin5uog",
"gin62ot"
],
"text": [
"\"Never touch\" is sort of a misnomer. If we zoom in enough, atoms aren't like billiard balls. They're more like clouds that, while more concentrated in some areas, diffuse smoothly out with no sharp edge. So \"touch\" isn't really a well-defined idea at that level - in some sense, every atom in your body is \"a little bit\" everywhere in the universe, although \"a little bit\" here is so little that it is zero for all intents and purposes. We don't actually need to zoom in quite that much to talk about touch, though, because even if the electrons in the atoms of your hand *were* billiard balls, they still create an electric field around them because they carry electric charge. When another object with the same electric charge gets close (say, the electrons in the atoms of your desk), it's repelled because two of the same type of charge push one another away. For a more macroscopic version of this, take two magnets. If you glue Magnet A to your table, and then hold Magnet B, you can \"feel\" Magnet A by moving Magnet B around even if they don't come into direct contact. While magnetic fields and electric fields behave somewhat differently (in a sense they're two pieces of one underlying thing), this should at least give you a sense of how you can feel a thing without making direct contact with it.",
"Well the confusion here comes at definitions, for example what exactly is to \"touch something\"? if you see what happens at the atomic level is that the electrons around the atoms repel each other and that force of repulsion is what you feel as \"touching\" something. so atoms do touch each other you just didn't really knew what touching actually was. The notion of things being a continuous solid is just an illusion caused by the scale at which we exist."
],
"score": [
17,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktotqs
|
Cheap vs Expensive Alcohol: What factors determine the ‘smoothness’ of a particular brand of alcohol?
|
I’m just sitting here, drinking some really cheap rum, and wondering why the more expensive version doesn’t burn quite so much. I think that I could probably make some educated guesses (along the lines of: more expensive = better) but i’m wondering if anyone can actually put into words why that is. Thanks in advance
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"ginruqj"
],
"text": [
"Two reasons, mostly: Distillation process and aging. During the process of distillation of fermented sugars and water, the first and last compounds to evaporate are not ethanol, these are called heads and tails. Better distillations discards a bigger percentage of heads and tails, which also makes the resulting product more expensive to make. Aging in barrels and filtering in charcoal allows for some of the more volatile and harsher compounds to evaporate or be captured, while also conferring some of the smokey or wooden flavor of oak. this process takes years, so it obviously increases costs too. There's a third reason, which is additives that make the drink smoother. This can be as simple as sugar to clear drinks or caramel to supposedly aged ones like rum or tequila. Glycerin is also sometimes used to add smoothness and an oily texture which you otherwise would only get from aging."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktpa9p
|
Why pain has levels how does body work and why do we feel like the leg fracture I had last week wasn't that painful like the hand fracture I have right now . And why emotional pain is more hurtful than the physical pain even it doesn't hurt in body ?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"ginccg1",
"ginds3v"
],
"text": [
"Pain is your body's way of saying that something is wrong, and that you need to take some kind of action. That action might be that you need to avoid putting pressure on the area (like a sprained ankle), it might be to drink more water (like a headache), it might be that you actually need to seek medical help. For physical traumas (like broken bones), the amount of pain can depend on how many nerve endings are involved. A paper cut is *very* painful because nerve endings are a bit like tree branches. As you get nearer the surface, there are many more of them than there were deeper inside. This means a paper cut involves a *lot* of endings in a small area. Emotional pain is similar. It's your brain's way of reaction to something bad to avoid it in the future. This could be a loss you've suffered (so take care of things or treasure what you have), embarrassed (don't do the embarrassing thing again), worry or fear (get out of the bad situation), etc. It may also be a sign that you should seek help from someone. If that's the case, then get help! It's just as important to see someone about your emotional health as it is to see a doctor about your physical health. I feel obliged to ask (although you don't need to answer) if everything's okay? That fact that you mention two broken bones within a week, as well as emotional pain, is concerning. I don't know your situation but, if you're having problems with someone, please don't be afraid to get help. Edit: thanks for the gold, kind stranger! But please, go forth and show love to folk!",
"Human brains aren't binary. They work off thresholds. They get signals and give signals differently based on hormone amounts, signal levels and other conditions. Basically different hormone levels and signals cause nerves to behave in a certain way. One cell can have many different responses to stimuli. It is better to imagine every brain cell as a small computer. That considers the inputs and conditions around it that then reaches a conclusion and gives a signal. Emotional pain is generally worse than physical because we are social animals. Also there are many kinds of emotional pains. We don't know how or why we evolved them, but it regulated our behaviour in a way that directs our behaviour towards beneficial behavior for our survival. Humans shouldn't be only considered as individuals, but as part of a group, because a lot of our behaviour revolves around being social."
],
"score": [
48,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktpjhc
|
do people who have arachnophobia also get freaked out by crabs?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gincotb",
"gindbxv",
"gine4wx",
"gingkjf",
"ginl2rc"
],
"text": [
"I have arachnophobia and am not bothered by crabs (crabs aren't arachnids, but I get where you're coming from). Also, bizarrely, I'm not bothered by tarantulas. No clue why.",
"I don’t, and I think it’s a combination of how crabs move, their body legs size ratio, their shell, and the existence of claws.",
"Sort of but spiders are small, fast and hide easily. I will say seeing crab legs at the supermarket is pretty creepy.",
"No. For me i think it has to do with how I imagine the feeling of crawling. When I see spiders I get so uncomfortable cus I imagine them crawling all over me which is an awful sensation. Crabs tho, because their body is different with the hard shell, holding crabs are pretty satisfying provided they don’t pinch u. I’ve had pet crabs before",
"Back in 2019 I had developed that fear/phobia due to waking up a few times to different big spiders crawling on my (one at a time) as well as constantly walking through spiders and seing a bunch of house spiders. However NO I was never freaked out by crabs because I knew they weren't venomous nor could harm me aside from the pain a claw pinch would cause which is minuscule pain in my opinion. I got rid of my phobia within a few months by learning which spiders are venomous and memorizing most of the ones that live in my state. Still not freaked out by crabs and never have been."
],
"score": [
33,
14,
5,
5,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktplvf
|
How live and living entities developed from "dead" matter?
|
*life
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gine8wd",
"ginlf80",
"ginoj7o",
"gio17j5"
],
"text": [
"Our best current hypothesis goes like this: * The building blocks for RNA can be found in nature. Given enough time, those building blocks assembled into strands of RNA by pure chemical means by chance. * RNA is unusual in that it can both be replicated (that is, it works as a genetic material) and can cause certain chemical reactions to happen faster (that is, it can play the same role as proteins do in modern biology). This led to some RNA strands catalyzing reactions that made those RNA strands reproduce or be more stable in their environment. These RNA strands became self-reproducing and exercised control over their environment in a way that depended on their structure, meaning that they were arguably the first living things. Examples of these isolated RNA \"organisms\" exist today in the form of plant diseases called [viroids]( URL_0 ). * Structures similar to cell membranes can form without the intervention of life, by purely chemical means. Some of those membranes eventually wrapped around a strand of RNA from the previous step. This allowed the RNA to work within a controlled environment. * These membranes-around-RNA-strands (what you could loosely call the first cells) figured out how to duplicate their RNA and to split the membrane, in such a way that they maintained control over their internal environment. At this stage, cells (and not RNA strands by themselves) became the fundamental building blocks of life. * A specific kind of RNA, what we'd now call tRNA, developed that could use RNA as a template to build proteins. This was better than the RNA doing things itself, because a single authoritative copy of the RNA could be kept and used as a template for thousands of proteins. At this point, proteins became the main (though not the only) functional molecules within a cell, with RNA taking a back seat in the role of pure genetic material. * DNA's building blocks can also be found in nature. DNA is a bit harder to assemble, and more importantly can't directly \"do things\" like RNA can. Because RNA can cause the formation of other RNA or proteins, it could create a new type of RNA that \"copies\" information off of DNA (what we would now call mRNA). Because DNA is much harder to damage than RNA and can be more easily repaired because errors can be detected from mismatch between its strands, DNA became the main way to store information in cells. RNA was now neither the main genetic material nor the main functional molecule, and instead took on a role as an intermediate between DNA (genetic material) and proteins (functional molecules). It's around this point that the last universal common ancestor - the single cell that would ultimately produce all cellular life on Earth today - lived. All cells known today: * use DNA as their genetic material, * use DNA to produce RNA according to a specific mechanism, * use that RNA to produce proteins through a code that is almost universal among living things (a very few organisms later evolved slight modifications), * and use those proteins to carry on the functions of life, * within a cell membrane of phospholipids that separates the cell from its environment. Other kinds of life probably existed at this time, but none of their descendants have survived to the present day. Note that modern cells actually do carry remnants of this very early world, with [RNA acting as a catalyst]( URL_1 ) in specific parts of even modern cells. The theory I've summarized above is the \"RNA world\" hypothesis. It's generally the best-accepted theory today, but there are a number of competing theories that are also possible; it's possible we'll never truly know the answer to this question. Our best guess is that this process happened over a few hundred million years, beginning somewhere between 3.5 and 4 billion years ago (shortly after the formation of the Earth), probably at volcanic vents in the ocean.",
"It’s a bit easier to grasp when you reflect that life is just chemistry and physics. That’s happening all around us all the time whether it’s in life or not. Asking why “dead” things can make life is kinda like asking why sand, metal, and plastic can become computers, or why simple atoms can become the Himalayas. No atom in your body is “alive” yet the aggregate...is. Nifty things can happen when lots and lots of things come together in specific ways.",
"\"Life\" is just chemistry and physics of a myriad of compounds. The same laws and reactions govern the interactions of \"dead\" matter. There really is no fundamental difference between \"living\" and \"dead\" matter. This makes your question confusing and hard to answer - there really cannot be a clear cut answer on how A turned into B, if there is no celarly defined difference between the to begin with. I guess the answer would be \"It didn't - the chemical system just got more complicated, but it's still not that different\".",
"There is no live matter. There is no dead matter. The atoms in your body are no different to the atoms of the wooden table you're leaning against. Your body incorporates atoms that are exactly the same as the stone floor you're standing on. Life is a process, a particular configuration of atoms where they make up one or more cells, and those cells are capable of replicating themselves. Theoretically we could study a cell well enough to assemble the right atoms in the right configuration and we would \"create\" life. How we got from a state where there was no life to the first self replicating system is a matter for much debate. It seems likely though that this step is not actually very difficult, however in a world that is now full of life anything naturally arising from these processes would be immediately consumed by something who's ancestry goes back billions of years and is specialized in generally eating anything the same size as it."
],
"score": [
154,
42,
7,
3
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"text_urls": [
[
"https://en.wikipedia.org/wiki/Viroid",
"https://en.wikipedia.org/wiki/Ribozyme"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktppqm
|
Why does cola fizzes more when poured on a new cup than poured on a cup that previously had cola on it?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gine6xw"
],
"text": [
"Bubbles form faster on rough, dry surfaces. Drop a grain of sand into a carbonated drink and you will see bubbles rising up from it. What happens is that it is easier for a bubble to grow larger than it is for a bubble to “start”. These rough surfaces contain a fair amount of trapped air in the cracks. That trapped air becomes a place for bubbles to grow and break off. These are called “nucleation sites”. A new cup is going to have a fair amount of these dry rough places. Imperfections in the glass, etc. A used cup will still have these but it will also be coated with a thin film of liquid. There will still be places for bubbles to grow, but perhaps not as many."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktqco9
|
Why do people sleep walk?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"ginhgfv",
"ginha7t"
],
"text": [
"We don’t know. There are several theories and it seems like certain illnesses, mental disorders and fever can contribute to it, but there in no known scientific reason. It does appear to be genetic however, children with 1 or more parents that sleepwalk are something like 50% more likely to do it.",
"Normally when we sleep, our motor center is shut down to prevent all the activity going on in our brain from stimulating our muscles. This sensation of near-total paralysis is known as sleep paralysis. Sleep-walking can occur when that step to shut down the motor center and induce paralysis doesn't occur, causing the semiconscious sleeper to act out their dreams or otherwise carry out actions while most of their conscious brain is deactivated and sleeping."
],
"score": [
4,
3
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|
[
"url"
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[
"url"
] |
|
ktqgj0
|
What prevents drip coffee makers from brewing coffee as well as a pour over? What is it about manually pouring the hot water over the grinds that makes it taste better?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"ginhyei",
"ginjnut",
"ginqjkk"
],
"text": [
"One big aspect of making good coffee (other than the beans and roast) is the relationship between the grind (coarse/fine) and extraction time. (plus water quality and temperature etc etc) An average drip coffee maker (with a large filter and large amount of coffee) will take many minutes to make the coffee where a lot of hot water drips over the grind over a long time. This will over extract the coffee and this leads to bad tasting coffee. Part of the art of the handmade pourover or frenchpress etc method is that the extraction time is controlled carefully and a relatively small amount of coffee is made at one time. It is also typical for drip coffee to be pre-ground ahead of time and stored in packages. The quality of the coffee decreases the longer the time between the grind and extraction.",
"There's a great answer here already but I just wanted to add that there's also a temperature problem with drip coffee makers. To save on costs, there's usually a single heating element at the bottom, under the coffee jug, which evaporates water that rises to the top, and then drips down through the coffee once it condenses. The heating element also heats the ready coffee in order to keep it warm over the long brew process, but because the heating element has to be boiling hot to evaporate the fresh water, it ends up burning the ready coffee, for a long time, which leads to a more bitter taste. This could of course be fixed by having two heaters, one to evaporate the water and another to keep the coffee warm, but of course this costs more so it's not usually the case. For a pour over you can first of all brew with a lower temperature, as the water doesn't need to boil, I think somewhere around 70-80°C is better than straight up boiling 100°C, and once the coffee is brewed it tastes fresh and sweeter since it hasn't sat still over a boiling hot coil for a long time.",
"Two good answers here but a third point: Clean fresh water is *most* of a good cup of coffee and you're not getting that from a typical machine dripper. The reservoir, the coil, the tube to the basket are all wonderful homes for bacteria and mineral deposits, and the plastic tends to hold oils from the beans. Unless that whole system is cleaned and dried daily and descaled regularly, it will never deliver water as fresh as directly from a pot or kettle. I have a coffee connoisseur friend who keeps a personal drip machine high in a cupboard away from his wife and children. He cleans it and dries it daily and only puts bottled water in it. It makes a fabulous cup of joe."
],
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13,
5,
3
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|
[
"url"
] |
[
"url"
] |
|
ktqjeu
|
If skin is a watertight barrier, how do medicinal creams work?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"ginhlu0",
"ginhauq",
"gini1tk"
],
"text": [
"Its not watertight, its semipermiable. You have cells that act as a sort of mesh. They allow some things in and some things out. Medications can be transpported into those cells when applied to the skin and they can transport that to other cells and into the blood.",
"It's watertight, but some substances that are not water can penetrate the skin. A famous example is dimethylmercury, which can penetrate not just the skin but a rubber glove on top of it, with [fatal results]( URL_0 ).",
"Short answer - skin isn’t actually watertight. Slightly longer answer - skin is quite porous; has to be to let sweat out, for example. What skin blocks is not so much water as (significantly larger) particles. As an example, silver miners can develop argyria, recognizable by a bluish skin tone from a high concentration of silver dust that’s gotten stuck in their skin. Not going through, just stuck in the skin; water particles are smaller, and get absorbed by the skin, as it is allowed to seep ever so slightly through it."
],
"score": [
13,
5,
4
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Karen_Wetterhahn"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktqowl
|
Why does the northern part of North America, Asia and Europe become so much colder and get so much more snow in their respective winter months than the southern part of South America during theirs?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"ginu6ch"
],
"text": [
"The southern part of South America is not nearly as far from the equator as the northernmost parts of North America or Europe. Ushuaia (pronounced \"oo-SWHY-uh\"), Argentina (the southernmost city of any size in South America) is at about 55 degrees South, which is about the same latitude as the southernmost tip of the Alaska Panhandle, Dublin, Ireland, or Hamburg, Germany. Compare Oslo, Norway (59 N), Helsinki, Finland (60 N), or Anchorage, Alaska (61 N). That's half the reason. The other half is that the southern tip of South America is rather thin, which means its climate is moderated by the ocean around it. This effect is even stronger because Antarctica has a very strong current running in a circle around it that keeps antarctic waters isolated from the rest of the world's oceans. This keeps the coldest weather isolated to Antarctica. As a result, Antarctica is *far* colder than the high Arctic: the Antarctic Peninsula at 63 S almost never goes much above freezing, while a hot day in Fairbanks, Alaska (65 N) can be hot enough to be uncomfortable. This ocean moderation is why Ushuaia (55 S) isn't as cold as places like Moscow (55 N) that are well inland."
],
"score": [
27
],
"text_urls": [
[]
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|
[
"url"
] |
[
"url"
] |
|
ktqu1l
|
Why temperature and speed affects braking force?
|
Planes and cars have problems braking if brakes are too hot. F1 teams complain also if brakes are too cold. What's the reason behind so much variance? Also, I have noticed, that basically any vehicle have smaller deceleration when moving fast than when moving slow. From elementary school physics - when I apply some force onto surface, I should get some amount of friction, so I don't know why it changes. It this also related to the temperature, or is there unrelated mechanism behind it?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"ginn2bm"
],
"text": [
"Elementary physics is idealized. It typically assumes that the coefficient of friction is constant. In real life, the friction coefficient will change depending on temperature. The brakes are designed to operate within a certain safe temperature window and typical driving. For cars (not sure about planes), the brakes are NOT designed for repeated high braking operations done frequently. Doing this overheats the brake pads (boils the brake fluid too) etc and causes the brakes to fail or degrade. F1 cars, on the other hand, are designed to have repeated braking. The compounds used are most effective when the brakes are hot (much hotter than road cars) but conversely they operate poorly when below a certain temperature. You are almost certainly incorrect. Braking will cause more deceleration from a high speed compared to low speed. This is because the air resistance/drag at high speeds is much greater and this contributes to the car slowing down. But most drivers are conditioned or trained NOT to stamp on the brakes at high speeds because it results in the car sliding. So while it probably \"feels\" as though brakes work less effectively at high speed - that is related to the driver and not the physics."
],
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8
],
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|
[
"url"
] |
[
"url"
] |
ktqw91
|
How do OS installers works if there isn't any OS that could manage applications in an empty computer?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ginjcjx",
"ginjpvs",
"ginqr86",
"ginv7f3",
"ginj6ua",
"ginjgqn"
],
"text": [
"A computer has a thing called the BIOS built into its ROM. One of the jobs this has is to boot the machine--it can do this from the built-in hard drive, or a DVD-ROM, or USB key. Once it's booted from one of those sources it turns over control to whatever code it just loaded and stays mostly out of the way. So, the OS installer just has to be set up as something the BIOS can boot from and it will then run quite happily. Once upon a time, in the early days of PCs when you might not even have a disc drive attached, the computer would boot into a ROM-resident version of the BASIC programming language if it didn't find any other boot source, but they removed that a long time ago.",
"There actually is something *kind of* like a very rudimentary OS built into an empty PC, called the BIOS. It's stored on a permanent storage chip on the motherboard. The BIOS is the very first program the CPU starts executing once it's powered up, and it only has a few jobs. Its main job is to scan the computer for internal hard drives or other storage media, and then look at the \"boot sector\" (a short block near the beginning) of those drives, to see if there's any OS code there to run. If there is, then it loads and runs that code, and that's how Windows or Linux or whatever starts running.",
"To explain it a different way, the installer itself acts as a temporary OS. The BIOS activates it and then it's able to build a more permanent one. Kinda like when they put up a construction crane, they build it as a small version, then use it to build itself up to full height. You need that temporary small OS with no features other than the ones needs to install a bigger OS to make said larger OS happen.",
"After the excellent answers, it only remains to say that BIOS means Basic Input/Output System",
"A full OS isn’t needed to install the OS. The installer program contains the necessary code for the computer to comprehend.",
"You insert a boot medium (optical disk, USB drive, SD card, whatever) and tell the computer to load that OS during its UEFI/BIOS startup. It is loaded into memory and runs the computer from there. You then use that to install the permanent OS on the computer's durable storage so you don't need the boot medium every time."
],
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|
[
"url"
] |
[
"url"
] |
|
ktsqyn
|
Why are your hands slippery when dry, get "grippy" when they get a little bit wet, then slippery again if very wet?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"ginucip",
"gio2sqg",
"gio2ktu",
"giobc1m",
"gio2b01",
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"gio5y5x",
"giovv6b",
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"text": [
"Your body needs moisture to work properly. So the grip of your hands is kind of determined by all the ridges, and their ability to sell swell and squish. All those little lines, like your fingerprints and such, they fill with water when there's moisture, and then when you grab things, they are able to apply extra pressure, creating better grip. Obviously this swelling is near microscopic, but have you ever stayed in the water until your hands prune? That is your skin swelling to give you grip in such a wet environment. I'm using this to train for teaching my kids(1yr), hope this is good. EDIT:: Apparently this is not true, some say at all, some say partially. I really appreciate the likes and awards, but I hope all you people that are calling me out for being wrong are also down voting this, and upvoting the correct answers. This is what I learnt through my life.",
"Water sticks to water, making wet things stick to wet things. If the layer of water is thick the surfaces can easilly slide because water easilly slides across itself. However, if the water layer is thin and the surfaces aren't smooth then the surfaces can still touch in a lot of places. The water can still stick the surfaces together, but not be thick enough to make sliding easy, and the sticking caused by being wet makes sliding even harder than if the surfaces were dry.",
"A little bit of water (like licking your fingers to open a plastic produce bag) can help with grip in some circumstances but not all--this is why, for example, athletes sometimes use chalk bags. If you're talking about circumstances like opening a produce bag, then it's more to do with surface tension than with any potential softening of the skin layer, I believe.",
"There are two forces at work here when it comes to wet grip: Surface tension and Friction. Water molecules want to cling to things. When water is surrounded by water, it clings to the surrounding water. The surface of water, however, can't cling as much to surrounding water and thus will cling to anything that touches it. So, if you have a thin layer of water on your hands, the surface tension from the water will cling to things, which will feel a little grippy. But, if you add too much water, the water below the surfaces will cling to itself and become slick. The stronger force from grip comes from friction. Friction comes from frictional coefficient and force. Water lowers the coefficient of friction, so water will always make grip from friction weaker. So: Having slightly wet hands will provide grip to things that don't require force (like opening a plastic bag, which is really pulling the two parts of the bag apart, not gripping them) The surface tension will provide some cling. Too much water, however, and surface tension is negated by the slickness of the water under the surface. However, any wetness will reduce grip generated by friction, which is our main gripping ability, as we can control friction by pushing harder. So overall the grip \"from a little wet\" is only useful in certain circumstances, in almost every other case dry hands will aide grip more. Edit: I missed one thing: skin (and some absorptive fabrics and materials) soften when wet. This leads to a higher coefficient of friction. However, most non absorptive materials, when wet, have a lower coefficient of friction. Additionally, as I stated, too much water acts as a lubricant and lowers friction on most materials. So... It really depends on the materials and how much water there is water will make two materials grippier or slipperier.",
"If your hands are slippery when dry, your hands are either dirty or you're dehydrated. Hands are naturally quite grippy, of properly hydrated.",
"No ones hands are “slippery when dry.” What are you talking about? We literally chalk our hands before lifting heavy weights or doing bar work to get them as dry and abrasive as possible to maximize friction so we don’t slip. People this thread are weird",
"Water has a high surface tension. Think of this as water molecules being so attracted to themselves that they minimize the surface area at any water/air interface. This is why water forms into beads or droplets. If you add a little bit of water to your finger and apply it to a plastic grocery bag or book page, when you pull away the top layer of the bag or book page will move with your finger. Separating from your wet finger would require that the water/air surface area increases against the surface tension force which is trying to minimise the area. If there is enough water to produce a thin film between two sliding surfaces lubrication will occur. Some good examples of this are bearings, air hockey tables, or walking on wet brick. You would only notice this briefly while walking, but the thin layer of water would cause you to slip before your shoes contact the ground.",
"Im sorry if I dont understand this cause I dont have experience with American culture. But ELI5 like these confuse me. They seem to be asking for explanations on things that aren't true in the first place. I mean no offense. But I wonder if the OP can describe what they mean by slippery when dry and gripper when slightly wet. In my experience, any amount of water makes things more slippery, except in circumstances where things like plastic bags stick to water.",
"“Why can I masturbate dry, or with a ton of water in the shower, but not when my hands are damp?”",
"Water sticks really well to lots of things, so a little bit of it makes things grippy / sticky, BUT it doesn't stick to itself nearly so well so too much of it makes things slippy.",
"The surface tension of water is greater than the surface tension of your dry skin, which is mostly just tiny dead flaky bumps. Once you have too much water, no, you’re no longer dealing with service tension and now you’re dealing with fluid viscosity, which counteracts the tension. Source: science and 25 years of hyperhidrosis presenting primarily in the hands and feet",
"your hands get grippy when they're a little bit wet?",
"Is this even true? Is the point of chalk for climbers etc not to dry their hands to increase grip?",
"Old ELI5... Actually, when the ridge on your fingertips and hand get hydrated with water, combined with the crease, will act as a ventouse. Kinda like if you had a thousand of little ventouse on the inside of your palm hand so it stick to slipery surface."
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[
"url"
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[
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|
ktsrig
|
How do we know obesity is genetic and runs in the family? Is there something written in the DNA?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"ginz7dx"
],
"text": [
"It's not in our DNA as in, we have one gene that causes obesity (actually, there is one, but that's a different story). But people can have differences in their metabolism (as in how many calories you burn while resting) and presumably also in how strongly they react to hunger or to food cues (commercials, smells etc). Those differences are caused by an extremely complicated crosstalk between genetics, life style and even what your mother ate during pregnancy. So there truly is a genetic component, which means some people will just have a much harder time to remain at a healthy weight just because of how their body is 'designed', but it hardly ever is only this."
],
"score": [
10
],
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|
[
"url"
] |
[
"url"
] |
|
ktsxmh
|
; How do transition glasses work and why do they take so long to get back to normal after getting dark?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ginzrg5"
],
"text": [
"Photochromic lenses work because there are silver [cations]( URL_0 ) embedded in the lens. When these cations are exposed to UV light, a chemical reaction causes elemental silver to form. Because this silver is visible and less transparent, the lens darkens. The chemical reaction is reversed when UV light is not present. Because photochromic lenses don't work without UV light, indoor lighting will not cause them to change. Similarly, many people who first try photochromic lenses are surprised to find that they don't transition well while they're driving. This is because modern windshields are largely UV protected, and don't let enough UV light into the vehicle to change the lens. Many lens manufacturers now offer extra sensitive photochromic lenses that will work in the car, however, they can take longer to return to their clear state."
],
"score": [
7
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Ion#Anions_and_cations"
]
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|
[
"url"
] |
[
"url"
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|
kttr1c
|
How *thick* does a knife have to be to cut you?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gio0a2a",
"gio12nd",
"gio0whz"
],
"text": [
"The problem with neutrinos isn't exactly that they're small, it's that they carry no charge *and* are small *and* don't interact with the strong force, which gives them very few ways to interact with regular matter. But to answer your question, a good laser or carbon nanotube fiber would be capable of cutting through flesh with a thickness of no more than a couple of atoms.",
"Basically neutrinos don't count. They cheat the rules. To explain atoms never ever really touch anything, even other atoms. Atoms are mostly empty space, in fact. Instead they basically stop each other because their electro-magnetic fields push each other away. It's weak enough that it's only noticeable when they get really, really close to each other, but those electromagnetic forces keep them apart from each other. Since they are just mostly empty space, atoms could pass right through each other otherwise. Neutrinos have no electromagnet force. There is nothing for the atoms to push away. So they just pass right through them. It's not that they don't cut you because they are too small; they don't cut you because they are like ghosts that just move through you like you don't exist. They can be effected by other things. They are still bits of matter. Just not the specific thing that usually keeps atoms away from each other.",
"The edge of a sharp razor blade is a few hundreds of picometers. And it is able to cut things just fine. However if we go to smaller dimensions then a lot of our concepts such as cutting, width and touch starts to brake down. At these scales objects are not solid mechanical things but instead the world is governed by how the atoms and subatomic particles interact. So your question stops making any sense."
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[
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[
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|
kttus8
|
why are our months the way they are?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gio1e28"
],
"text": [
"Months are designed to line up with both the cycles of the moon and the solar year. But unfortunately, a year is not a neat number of lunar months. The moon takes about 59 days to go through *two* lunar cycles. So if you put a 30-day month and a 29-day month next to each other, each two month period corresponds to roughly two lunar cycles. Unfortunately, 59 days doesn't go nicely into a year: 365 / 59 gives 6 of these cycles plus about 40% of a month. So you can line up with the moon, but not the sun, this way. You could do the 12 x 28 + 1 x 29 thing, but that doesn't line up with the moon, and it produces a 13-month year that is hard to subidivide. The closest you can get to both is roughly our current system of alternating 31- and 30-day months, which approximate the month reasonably well (it's off by roughly 1 day each month) and are as close as you can get to dividing the year into days (because a year lasts 365.26 days, so you can't actually split it into a consistent yearly calendar - we solve this problem through leap years). Other calendars exist, which solve this problem differently. The Islamic calendar, for example, sticks with the nice months and drifts through the year, with any given month of the Islamic calendar falling in different seasons with each passing year. The cycle of Islamic months drifting across the solar year repeats every 33 years. The Chinese calendar varies a bit to roughly get them aligned at the cost of some back-and-forth drift in each month's place in the seasons. And so on. Most cultures do use a 12-month year of some form, probably because it's easy to divide."
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|
[
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[
"url"
] |
|
ktuicz
|
When we’re breathing normally, why does our body randomly take longer (deeper) breaths without us consciously sighing?
|
Might be a poorly worded question, but let me elaborate. Sometimes when we breathe, our body randomly decides to take a longer and deeper breath. I’ve noticed it isn’t just me who does this. I don’t consciously decide to take a deeper breath, but my body does so and I just happen to notice that that single breath was longer and deeper. Why does that happen? Note: this isn’t related to sighing when we’re sad, annoyed, or linked to emotions. It’s just a random breath that was different than the rest. Thank you in advance!
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gio6is3",
"giojbif"
],
"text": [
"We need to take breaths like that to reinflate collapsed alveoli ( the bit of the lung where oxygen blood and CO2 leaves it)",
"From what I understand, it’s an automatic response for when we need more oxygen. Our body tries to maintain a certain O2 percentage (obviously through respiration) and sometimes we just need a little boost!"
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ktv36b
|
Why is Bluetooth still so inconsistent in regards to connectivity and pairing previously paired devices?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gio8yof"
],
"text": [
"It's really nothing to do with inherent limitations of the technology, or with spectrum issues. A lot of devices have very good Bluetooth. It's mostly due to the fact that there are a buttload of devices using very cheap, poorly designed Bluetooth controllers, crappy antennas, and/or lousy software driver implementations. Consumers want Bluetooth connectivity (sometimes) and they want low prices. Very few consumers are going to research how good a device's Bluetooth connectivity is; it might even be hard to find such information. So some manufacturers just implement the cheapest hardware that they can get, and put minimal effort into the firmware. After all, you don't buy a refrigerator for its Bluetooth connectivity quality. You're also unlikely to return it because the Bluetooth is a piece of crap. It's like Ford back in the 60's figuring out that if they used cheaper bolts in their cars they could make millions of dollars in savings each year without noticeably driving off consumers. At least, not immediately. **TL;DR** - The race to the bottom."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktv90s
|
What will happen to animals and insects that use the Earth's magnetic field when the poles reverse?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gio92xh",
"gioaezd"
],
"text": [
"The earth's magnetic poles will not reverse overnight or over the course of even a few years; estimates are that it could take between a thousand and ten thousand years for a reversal to occur. All the critters will be adapting along the way. There are some estimates as low as dozens of years, but still, critters adapt or perish. URL_0",
"Pole reversals take a long time, much longer than the lifespans of these animals. Additionally, animals that use magnetic force tend to use it as a reference rather than simply being attracted to a particular direction, and use it as one of many cues. So for example, a bird that wants to make sure it continues in the same direction even when visibility is poor can use its magnetic sense to make sure it stays pointed the same way. And birds learn which way leads where when learning their migrations. But as long as the magnetic field doesn't shift much from year to year, they won't have a big problem."
],
"score": [
12,
6
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Geomagnetic_reversal#Duration"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktvdtp
|
Why does it seem harder to focus on a specific task when there is loud background music playing? (For example: reading something important, trying to parallel park)
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gioadm3"
],
"text": [
"Attention is a limited resource, it has a limited capacity. To concentrate on a specific task, it's often necessary to reduce or remove stimuli in the environment that are competing for that resource. Multi-tasking, even in a passive sense, divides attention. So, by turning off the music, you are freeing up attention that can be used to focus on the target task."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ktvpio
|
How living beings generate heat to stay warm?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"giobp97",
"giodbxu"
],
"text": [
"You can picture our cells as little molecular engines. Trillions of them making up your entire body, every single one burning ATP as fuel to power the metabolic reactions that keep them alive- in addition to countless other chemical reactions. This reaction in particular, splitting a phosphate group off to turn ATP to ADP, is exothermic- it produces heat as a byproduct due to the energy that chemical bond contained. The grand effect of this is a net heat increase, which is carried away from the cells by the bloodstream and radiated to the environment through the skin, much like the radiator and coolant system in a car.",
"When you do exercise you get hot right? Thats because your muscles are working and burning energy to do the work. Your muscle cells actually generate heat by breaking down energy molecules (atp) to do that work. Similarly, all your cells break down stored energy to do work. Every cell in your body is constantly doing work, which means its constantly breaking down that stored energy which is constantly releasing heat. You body harnesses this heat to help it work more efficiently. Blood acts to carry the hest around, along with nutrients and such, to important areas/organs of the body. However, sometimes the body makes more heat that it needs and too much heat can be damaging. So it can shunt blood away from the core of the body to the surface so it can exchange with the cool air and flow back. This keeps a balance of warm, but not too warm."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
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