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kqsac7
|
How do we know that the Earth's magnetic poles have shifted/flipped? And more importantly, why does it matter?
|
Physics
|
explainlikeimfive
|
{
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"Samples have been taken from rocks with iron content, that has been determined to have solidified at different times in the past. With a strong magnetic field more iron particles will be magnetized in the same direction, than with a weak field. And with some careful consideration for tectonic movement, you can get a pretty clear picture of what direction the poles were in at the time. Features, such as the Mid-Atlantic Ridge, are continually producing new rock.",
"> And more importantly, why does it matter? The discovery that the sea floor had alternating bands of magnetized basalt was clear evidence for the the theory that became known as \"[plate tectonics]( URL_0 )\". The older notion of \"continental drift\" had some impressive evidence in support, but no good idea of *how* land masses would drive around the planet. But now we know that the sea floor is being generated at mid-ocean ridges, and spreading out from there, carrying the continents as if on conveyor belts."
],
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6,
3
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[
"url"
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[
"url"
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|
kqtt5m
|
Why is 22 degrees on an air conditioner different from 22 degrees on a heater? Isn't it the same temperature?
|
Other
|
explainlikeimfive
|
{
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"If you've ever been near a big fire - such as a bonfire - then you probably noticed that the side of your body that was facing the fire felt really hot while the side facing away felt cold. The air on both sides of your body is the exact same temperature, so the reason for the difference is something called radiant heat. Every object radiates infrared light which your body absorbs and converts into heat, and this radiant heat accounts for a fairly substantial percentage of what the temperature feels like to you. The problem with measuring radiant heat is that your generic home thermostat is going to have a single, small temperature sensor on it. If you have that sensor measuring radiant heat then it will measure the radiant heat from whatever tiny point its aimed at. So if you happen to install the thermostat pointed towards a hot water pipe in the wall it will read blistering hot when the water is running and cold when the water is not. Or if you point it at something that is minimally insulated - like a window - then its really going to be reading the outside temperature more than the inside temperature. On the other hand, the air temperature in your house will be fairly consistent regardless of where you install the thermostat or what its pointed at. For this reason, the temperature sensor in a thermostat is insulated so that it can only measure your home's air temperature and not the amount of radiant heat that it is being exposed to. But that's only measuring part of what contributes to the temperature you feel. The temperature sensor in a thermostat is a tiny pin sized sensor, while your body is very large. Unlike the thermostat sensor, which can only sense the radiant heat from a single point, your body feels radiant heat as an average of the heat being radiated by the walls of the room. So why does this cause the same temperature to feel different when using the AC and heater? You only use the AC in the summer. During the summer, the walls in your house will be warmer and so will be radiating a lot of heat, which makes you feel hotter than you otherwise would. Conversely, you only use the heat during the winter. During the winter, the walls in your house will be colder and so they won't radiate much heat. Because there is less heat coming off the walls, you feel colder than you otherwise would.",
"* Heaters and air conditioners don't have the ability to produce air of a certain temp. * Instead they either \"make heat\" or \"make cold\" until the temp they measure in the room is that temp the user asked for. * So even if you set the temp to 22, the air coming out won't be 22. If you're in heater mode, it will be hotter. If you're in A/C mode, it will be cooler."
],
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11,
6
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[
"url"
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[
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|
kqulez
|
Out of all the random music broadcasts on youtube, how did that one anime girl Lo-Fi we've all seen come to dominate?
|
Other
|
explainlikeimfive
|
{
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"Lo-Fi (and anime-ish artstyle) resonates with people who spend a lot of time on youtube and thus ChilledCow's livestream was promoted to more people by youtube's recommendation algorithm, as something that obviously can't be bad if so many people like and follow it. It doesn't hurt either that ChilledCow seems to put a decent amount of work into keeping the music selection fresh",
"Youtube has a list of semi-secret rules that determines what people see. A couple of years ago, that was changed to favor videos longer than 10 minutes. The longer the video was, and the more of the video that got played before skipping ahead or moving to another video meant more people got to see it suggested as the next video to watch. Like a lot of content that was popular on youtube before, the duration of most music clips fall into the 2-4 minute range. Lo-Fi beats happens to follow the rules for Youtube to list it as a suggested video. It's much longer than 10 minutes, and a significant number of people who click on it play it all the way through at normal speed. Even people who didn't use it as background noise saw the art in their list of suggested videos enough for it to become iconic."
],
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12,
12
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[
"url"
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[
"url"
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|
kquocn
|
Why does meat spoil in weeks in the refrigerator but can be in cans for years without spoiling?
|
I have wondered that for the longest time and google doesn't help me. So why is it that canned meat lasts so much longer? Even if you salt the meat in the fridge it seems to still spoil quickly. Whats with that?
|
Biology
|
explainlikeimfive
|
{
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"gi5xa79",
"gi5ywqi"
],
"text": [
"Meat spoils because of bacteria and such in the air, but the process of canning (unless done wrong) removes any air and seals the meat.",
"There are two ways that meat can spoil. 1- Bacteria start to multiply on the food 2- They lose moisture (it is still safe to eat, but the flavor isn't really nice) In theory, the meat shouldn't spoil for an indefinite amount of time if it is cold enough, however, most freezers have systems to prevent ice from forming on the walls of the freezer, that rises the temperature to above the freezing point, and collect the moisture in the ambient. It will be too slow for (1) happening, but (2) will happen after a while. That's what we call a freezer burn. Canned food on the other hand, don't rely on temperature to prevent food from spoiling, and is airtight, so meat won't suffer from freezer burn."
],
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8,
3
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[
"url"
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[
"url"
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kquvpw
|
What's stopping us from freezing and reviving humans?
|
I'm curious about this. I'm guessing the issue is more around the reviving, because freezing someone would obviously stop all their vital functions - is there any chance a defibrillator would work, or is it currently an absolute nope, medically speaking?
|
Biology
|
explainlikeimfive
|
{
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"gi6ldui"
],
"text": [
"Firstly, pretty much all cryopreserved bodies have to be preserved post-death due to the extensive work that has to be done to prepare them. The biggest concern you need to work around with freezing and preserving bodies is ice damage. Water expands and turns crystalline when it freezes. This risks basically shredding everything in your body in the process, you have a lot of water in your tissues. With small organisms like an embryo or egg and sperm, you can do your best to replace as much water as you can with preservative and freeze it safely if you work fast, and if it fails occasionally it’s not a huge deal. Unfortunately this process has a lot more risk on something huge like a full human and wreaks havoc across the body. In addition to the ice issue, chemicals needed for cryopreservation are pretty toxic, and tissues starving from oxygen loss during the freezing process is a thing that happens. Revival is firmly in the realm of sci-fi right now as repairing the brain and body damage a corpse goes through in the process and bringing it back to life stretches far beyond what our medical capabilities can do."
],
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3
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[
"url"
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[
"url"
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kqvgfm
|
Why do you need to take many small samples when taking a bloodtest? Why can’t they just take one and use small amounts from there?
|
Other
|
explainlikeimfive
|
{
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"text": [
"As blood sits in the tube, more specifically, blood cells sit with serum/plasma, chemical reactions are still occurring. As a result, some chemicals we are testing for may be reduced or increased depending on the specific test. For all tests and instruments there are specific ranges of time which the blood can be used for that specific test before it has been in the tube too long to match the levels in the body.",
"It depends. Blood deteriorates quite rapidly outside of the body so they need to either do the tests right away or add anti-clotting agents to the blood before sending it to the labratory. However different chemicals may affect the tests so depending on what test is going to be conducted you might have to use different anti-clotting agents. Some of the chemicals added to the blood might also be part of the test and just needs to be added as soon as possible. There are ways to reduce the amount of needles used when taking multiple tests. You can hook up multiple vials to the same needle either one at a time or all at once. Another way is to first draw blood into a small bag and then use this to fill up the test vials. However the nurse still have to do this initial blood work all at once. So quite often the nurse is sitting in front of the patient handling their blood in order to get it into the correct vials and doing some tests. If you have issues with seeing blood you can tell the nurse about it and they will try to hide it from you.",
"Each tube's additives prepare the blood for the testing. If you're counting blood cells you need the blood not to clot (so the blood is still liquid and cells are discernable) so you use an anticoagulant tube. If you want to test for serum electrolyte levels, you use a tube that, when spun in a centrifuge, will separate the liquid portion of the blood from the solid (and clotting is ok, even preferable). If you want to test for certain types of metabolic activity you sometimes use a tube whose additives kill all the cells inside, essentially \"freezing\" the metabolism of the blood which continues as long as those cells are alive. This maintains the levels of the chemicals you're trying to measure. Each color tube has specific additives (or none) that make testing possible."
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5,
3
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[
"url"
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|
kqvvrx
|
Why is the South Pole so much colder than the North Pole?
|
So, Antarctica is basically a horrific wasteland where it regularly reaches minus 70 degrees Celsius and where nothing can live except some penguins on the northern sealine. In contrast, the Arctic is pretty cold, at around minus 40. But 30 degrees is a massive difference, and they both get the same amount of sunlight. So why is the coldest part of Antarctica so much colder than the coldest part of the Arctic?
|
Earth Science
|
explainlikeimfive
|
{
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"text": [
"Being near water, even cold-ass water, moderates your temperature a bit. Cities next to the ocean usually don't get ultra-hot summers or ultra-cold winters. In the desert, with no water to smooth things out, you broil all day and freeze all night. The north pole is actually over the Arctic Ocean; when you're standing there you're standing on ice with 0^(o)C water underneath. But the south pole is in the middle of a continent, a couple thousand miles from water. Makes a difference.",
"There are ocean currents under the ice in the arctic which mixes the cold water in the Arctic ocean with warmer water from the Atlantic and Pacific oceans. However the South Pole is located in the continent of Antarctica. And even though there are huge fjords and islands the glaciers displaces all the sea water forming a thick layer of ice all the way out to sea. So there are no ocean currents mixing the water on the continent with the water in the oceans. Another factor is that the ice cap on Antarctica is pretty tall making an artificial platau of ice that only a few mountains stick out of. This means that even though the Amundsen-Scott station is near what would have been coastline in a fjord if it was not for the ice the station is still at an elevation of about 2800m and dropping. Higher elevations means lower pressures which means lower temperatures.",
"Two things i know of: - North pole sits on water. Water is a great heat buffer (heats up in summer and gives off heat in winter) and conductor (streams like the gulf stream transport warm water to the pole). South pole sits on land. - the south pole is a mountain-plateau (e.g. the geographic south pole is at an elevation of ~2800m). At that height things would be pretty cold even in temperate regions. Might be more reasons ofc.",
"Another thing not pointed out yet is that there is a complete ring of ocean without land between Antarctica and the other continents, whereas Asia, N. America and Europe break up this ring in the Arctic. Having that unbroken ring means there is a fast current going all the way around Antarctica, blocking warmer water from the north from getting to the continent. A similar thing happens with air currents."
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[
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[
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kqw2yb
|
How come journalists are able to find/interview wanted criminals yet authorities have a hard time catching them?
|
Other
|
explainlikeimfive
|
{
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"text": [
"Wanted criminals contact journalists when they want to make their side of the story public, they don't tend to contact the police unless they're giving themselves up.",
"Are you thinking of people like Julian Assange or Ed Snowden? Some fugitives are 'hiding in plain sight' - it's not that people don't know where they are, it's just that there are rules preventing the authorities from making an arrest. And sometimes the reporter just finds them first - some reporters are really smart, and would have made great detectives. Fugitives might even be eager to talk to the media; they could call a reporter and say \"I want to tell my side of the story; can you meet me?\".",
"The police have a much higher burden of proof then journalists and have to follow much stricter laws. Police might \"know\" where a wanted criminal is and who is hiding them but they might not be able to prove it enough for a search warrant or they may be in an area the police does not have authority over and the police that do have authority does not prioritize the case. Then there is the issue of getting enough forces into possition to actually do the arrest without raising suspicion allowing them to flee. It is much easier for a single journalist to prove who they are and get access to people without a search warrant. However it is one thing to get access to someone in order to do an interview but another thing entirely to actually be able to arrest them, especially if you have to fabricate all the evidence of you being a journalist and hope that people do not notice that you are not. There are cases where politicians, and even police, have been visiting wanted criminals in order to negotiate or while conducting investigations. But it is almost impossible to arrest someone under those conditions."
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"url"
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[
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kqxbmq
|
How come when nail grow, the flesh under them doesn't come forward along with the nail as it grows?
|
Nails have a fleshy bottom layer attached to them that somehow doesn't come forward with the nail as it grows, why is that?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"The 'fleshy bottom layer' (or nail groove) contains the dividing cells. The way you can see it is that when the cells here divide, one daughter cell will remain and will keep dividing. The other one will migrate up towards the nail, start to produce a lot of keratin (the stuff that makes our nails so strong) and will eventually die and become part of the nail itself. So the nail groove doesn't move, but continuously pushes new keratin into the nail, this pushes the already existing keratin further up, thus our nail grows. Edit: just to make sure this isn't misunderstood: the nail groove is at the base of the nail, not the whole skin UNDER the nail, that's the nail bed (the nail groove is it's most proximal part, so there where the nail bed and nail itself meet (this needs a picture...)).",
"My sister is a nail tech and it DOES grow. If properly treated your nail bed become longer (more pink less white) this is needed for nail art competitions. In 6 months mine have grown 3mm. If you want to do it don't cut your nails only file and moisturizer.",
"another question id like to add: why do we grow nails?",
"The flesh of the nail bed is actually a very thin epidermis. It's one of the reasons your nails appear red because the the dermis underneath is full of blood vessels. Your nail grows over this epidermis starting from the nail fold, an area under the cuticle. The nail grows towards the tips of your fingers over the nail bed, while the cells of the nail bed contribute to the thickness of your nail. Just like the cells of the epidermis on the rest of your skin, the cells of the nail bed that contribute to your nail fill will keratin, flatten, and die, causing them to detach from their neighbors. This is why the flesh isn't pushed forward as the nail grows.",
"Since no one seems to be answering the actual question... Imagine you are on the playground and there is a set of monkey bars ([these things]( URL_0 )). But they are very special monkey bars. They are attached to a motor that makes them move (almost like a conveyor belt or a treadmill), and you can just stay in place swinging from one bar to the next as they move above you. If they move too fast you would be dragged along, but since they move slow enough, you have time to swing along and keep pace with the motor. Similarly, your nail grows so slowly that the skin cells it's attached to have time to adjust to the movement. That's why the flesh doesn't come forward also.",
"Your nail bed length and shape is genetically predetermined. The hyponychium, the fleshy part under your nail where the nail bed meets the nail plate, is essentially a guardian seal to help prevent any dirt from getting under your nails, same with the eponychium which is up near the keratinized proximal nail fold (commonly confused for the cuticle). It can become detached (onycholysis) due to picking/scraping under the nail, chemical reactions (looking at you, Mentality Polish), or from hitting your nail at the wrong angle and having it lift from the nail plate. In this instance, the nail bed will eventually reattach itself but it won't grow the nail bed any longer than it was initially. Some people have a hyponychium that extends past the tip of their finger and when they break a nail, this can be incredibly painful. In cases of severe nail biters, the nail bed can reattach itself & lengthen as the nail is allowed to grow out, but it will not be any longer than it was before the nail biting habit was formed. That being said, if anyone has any questions regarding nail care, please don't hesitate to message me. Nails are a passion of mine!!",
"Speak for yourself, I left my big toe untrimmed too long and now that skin has grown out some and I can't cut the nail back as far as it used to, very irritating...",
"Is anyone going to actually answer the question ?",
"The nail starts stacking up from the beginning, but the hyponychium (the skin just below the nail that completes the seal) stays mostly at the same place. However, I have a condition in which the skin does grow and the hyponychium may go past the nail. I may occasionally tear that skin when doing something with my hands.",
"Wheels. There are wheels there... ...I have a five year old. Okay, so the flesh that renews itself there is probably faster growing and so it works, LIKE wheels or a conveyer belt at the grocery store. Or your fingers unrolling the toilet paper roll, by the way don’t use QUITE that much paper, dear. ELI5, mom edition... have a happy day folks. Hope you laughed. :)"
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[
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[
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kqy3u9
|
What is the clicking/creaking noise that a TV makes some time after it has been switched off?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Many electronics get warm while running. Thermal expansion causes the cabinet to increase in size. When you turn it off and it starts to cool the movement in the cabinet pieces is what’s making the creaking noises you hear. You can often hear similar noises from your heating and air conditioning system.",
"Some TVs contain relays, which are mechanical switches that turn things on or off inside the TV. You could be hearing the TV turning the relay off and going into low power mode after a period of sitting idle. The Sony TV at my parent's house randomly clicks throughout the day."
],
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14,
5
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[
"url"
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[
"url"
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|
kqyh71
|
How does music frequency work and how does it affect you (432 Hz etc)
|
Other
|
explainlikeimfive
|
{
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"gi6fq7h"
],
"text": [
"Frequency means how frequent something is, or how often it happens. Like for instance, how often the air vibrates back and forth. Musical sounds, when we talk about their frequency, we're talking about how many times in a second the movement is repeated. A sound whose frequency is 100 Hz, is a sound which makes the air move back and forth exactly 100 times per second. The frequency of a musical note corresponds to what we hear as its pitch. When different frequencies are heard together at the same time, they produce different timing relationships which can sound really pleasing to our ears, and we call that \"harmony\". The harmonies which exist between different frequencies of notes, arise from mathematical relationships between those frequencies. There are a lot of people who say that music which features 432Hz pitches, or music which is tuned *relative* to a 432Hz pitch, is somehow special, that it activates special parts of our brains or connects us to the universe or something. That is a pile of superstitious mumbo jumbo though, and is [not taken too seriously]( URL_0 ) by anyone who really studies music or acoustics."
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[
"url"
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[
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|
kqywxd
|
Why is bright light so harsh on your eyes when you’re hungover?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi6m61x"
],
"text": [
"There’s a couple reasons but for one, heavy drinking typically effects how you sleep denying your body the heavier resting stages of the REM cycle, so your body overall is going to feel less rested. Secondly alcohol relaxes blood vessel so a long night of drinking means your body is feeling used to this relaxation, as the alcohol leaves your system your blood vessels tighten up to make up for the long period they were so relaxed causing eye strain. It’s a symptom of withdrawal from a mild poison."
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3
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[
"url"
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[
"url"
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|
kqz9pq
|
how do they know what IP address sent an email?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gi6l1ys",
"gi6kk7j"
],
"text": [
"* Emails have a lot of extra information that most email programs and services don't show you because most of the time you don't care. * This is called \"header\" information and it contains the IP address of the server that sent the email. * It also contains a lot of other stuff too most of which can be very confusing if you don't know what it means.",
"The sender had to make a connection to the receiver. That process will always provide the receiver the IP address of the sender. Thus, the receiving emails server can log what IP address sent a particular email. The sender can use a proxy of some kind to hide their real IP address though."
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10,
3
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[
"url"
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[
"url"
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kqzywc
|
Defibrillators don't restart a flatline like on movies and TV. But how DO doctors/EMTs restart a totally stopped heart?
|
It only took a little googling to learn about fibrillation, cardiac arrest, and how CPR is only temporary. Other than screaming "Live, damn you!" And slamming fists on the patients chest whilst the camera zooms dramatically, (eye roll) what do the professionals really do? Is a flatline just game over? Or is fibrillation much more common than flatline?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"“Flatline” is correctly called asystole, and is a non-shockable rhythm. Management is adrenaline, chest compressions, ventilation, and try to fix the problem that got you there. As you can imagine; this is often not very successful. For more cardiac arrest guidance, have a look at the UK resuscitation council guidance and flowcharts, but broad principles are gas needs to go in and out (ventilation) blood needs to go round and round (chest compressions) and you need to remove whatever insult stopped the heart in the first place. Note: I am UK based, so apologies if your local guidance doesn’t match this.",
"Slamming a fist on someone's chest when their heart has stopped is an actual medical procedure. It's called a pericardial thump.",
"For a flatline you inject adrenaline into the heart, which can (with luck) get the muscles moving again. CPR can sometimes cause it to start again on its own. Either way, chance of success are low, success without braindamage even lower. Fibrillation is more common than flatline, yes."
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[
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[
"url"
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kr0tgl
|
Why is light sensitivity a symptom of food poisoning?
|
How does a sensitivity to something in your surroundings, like light, develop out of common food poisoning? Is it a biological response or something similar?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi6udhe"
],
"text": [
"Most of the time, food poisoning results in gastroenteritis as a pathogen in the gut multiplies rapidly and secretes toxins that inflame the walls of our digestive system and cause the classical symptoms-nausea, diarrhea, etc) of food poisoning as the body purges them out. However, there are some dangerous pathogens that are able to escape the digestive system and infect us directly, causing more systemic symptoms including in our nervous system. Photosensitivity can occur when the nervous system is in a sensitized state from such an infection, causing the electrical impulses being transmitted through the optic nerves to feel unpleasant. It's a fairly broad condition with numerous causes."
],
"score": [
8
],
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|
[
"url"
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[
"url"
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kr0x9g
|
Galileo's ball experiment
|
You release a bowling ball and a feather from the same height, in a vacuum so there's no air resistance, and they will both hit the ground at the same time. Got it. But why? I feel like I understand most of it but I just need that one explanation that will make it click once and for all. I've taken a physics class and am about to take a second one so I understand F = ma and how to rearrange equations like that for the sake of doing homework problems but I'm trying to fully grasp it conceptually.
|
Physics
|
explainlikeimfive
|
{
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],
"text": [
"The gravitational force generated between two objects is proportional to their respective masses. So take some object - O1- with mass - M1 - and the Earth. We'll call the gravitational force between O1 and the Earth: G1. Take some other object - O2 - with mass - M2 - and the Earth. We'll call the gravitational force between O2 and the Earth: G2. If the mass M2 is twice the mass M1, then the gravitational force on O2 will be twice the gravitational force of O1. Seems simple enough, so the gravity is stronger on the more massive object. So why doesn't it fall faster? Because more massive objects require more force to accelerate them the same amount (via F = ma). We can rearrange F = ma to be a = m/F. If you want to accelerate two objects by the same amount but one object is twice as massive as the other, then you will need twice the Force. So the force needed to accelerate the bowling ball and feather by the same amount is exactly provided by the extra gravitational force applied to the bowling ball versus the feather. It all evens out.",
"If you are approaching this through the equations (rather than intuiting), then you should know Newton's Law of Universal Gravitation. The force of gravitational attraction between two bodies F = G\\*m1\\*m2/(r\\^2) m1 and m2 are the masses of the objects and r is the distance separating them (distance between center of mass) You already know F = ma. So equating the two equations (m2 = m mass of object and m1 = mass of earth). m a = G m m1 / (r\\^2) cancelling m - the mass of the object (feather or bowling ball) a = G m1 / (r\\^2) This shows that the acceleration due to gravity is independent of the mass of the object. G, m1 and r are the same for the feather and bowling ball.",
"One thought experiment which have helped me understand this is to imagine two similarly sized objects being dropped, and then imagine what happens differently if you tie them together. The string between them does not hold much force at all so you would not expect it to make any difference. So it does not matter if you drop one big object or two small. The big object would just behave as if it were many small objects tied together and all of them falls down at the same speed. Of course there may be some difference if you start discussing aerodynamics and such. However if the objects are dense and the distance they fall is not too far it should not be a factor."
],
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10,
4,
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|
[
"url"
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[
"url"
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kr1kkd
|
how mirrors seem to be the color of what they are reflecting while also looking silver.
|
I have been wondering this since I was a child and it’s never been explained in a way I can understand. I’m looking at my bathroom mirror and it looks silver. But how is that possible because it’s reflecting whatever is in front of it? So when I look at the reflection of the towel in the mirror i see blue, when I see the reflection of the wall I see white, when I see the reflection of the shower curtain I see the color of the shower curtain. But when I look at the mirror as a whole it seems silver? I think I have read that mirrors have silver backings which makes sense why I see silver. But I don’t understand how it’s possible to see the exact reflection of my bathroom but it’s also silver?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi741ro",
"gi760b2",
"gi8j6uw",
"gi7u65x"
],
"text": [
"\"Looking silver\" is what we call surfaces that reflect their surroundings. It's not actually a color. So \"seeming to be the color of what they're reflecting\" and \"looking silver\" are one and the same thing, just different ways of describing the same appearance. If you put a silver object in a uniformly illuminated room with blank walls it wouldn't \"look silver\", it would look like one uniform color. But that's a really contrived setup that \"never\" occurs in our day-to-day experience so we don't associate that with \"looking silver.\"",
"Human brains are really good at reasoning out color properties of objects, despite differing environments. Like some red berries will look different at sunrise versus noon because of the different light hitting them, but it was important to the survival of humans to be able to realize it was the same substance. So, we don't *just* evaluate the color of the light that actually enters our eyes. There's a secondary step of evaluating the environment around the object, to make adjustments to the perceived color. You can see this with optical illusions like [this one]( URL_0 ). In that example, we evaluate two squares of the same true color to be two *different* colors, because of how we interpret the surrounding light and shadows. With that established, let's consider reflections. Reflections aren't a new invention, as natural reflective surfaces (like still lakes and puddles) are ubiquitous. So, we evolved to deal with those as well, and to realize that even if something was tinted a different color in a reflection because of how the material did not reflect all light with the same intensity, it wasn't different from the original reflected object. Instead, we interpret the reflecting surface as having a particular color, which gets mixed with the original image. If you look at a polished gold candlestick or something, the reality is that the light from other objects is reflected and we're seeing that--but the gold alters the reflected light a bit, so we see different color components at different intensities. The way we model that in our brain is to think of that object as being *reflective* but also *gold* in color--although an intrinsic color really isn't a thing that exists in reality. It's a shortcut for our brains to process the world around us quickly and effectively. So, what happens with a surface that reflects light rather evenly? Well, if it's rough and scatters light randomly, we see it as a matte gray. If it is smooth and therefore reflective like a mirror, we can see the color of individual reflected objects clearly. But our brain, of course, works a certain way for evaluating reflected objects. We think, \"the original color of the reflected object is this, and in the mirror it's this...which is basically the same...So what color does that make the mirror?\" And the answer is, the same color as a rough surface that reflects light evenly across the spectrum, or in other words: gray. So it's not exactly that the mirror *is* gray, or any specific color. But our brains want to assign a color to it so that we can internally model what we are seeing, and the color that works correctly for that purpose is gray.",
"Take a close look at airbrush art that portrays large sections of silver or chrome and identify each of the colours section by small section. You'll see there's no silver in it. But if you stand back, you see \"silver\". Mostly the shiny surface is just white with other colours mimicking a reflected surface.",
"When you look at a yellow object, that means that object is absorbing all the other colors except yellow. That yellow is reflected back in all directions. A mirror reflects ALL colors back in a *single* direction, creating a mirror. If it reflected all colors back in *all* directions, that's where you get the color white :-)"
],
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65,
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"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Checker_shadow_illusion"
],
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}
|
[
"url"
] |
[
"url"
] |
kr25of
|
Why are we surprised at recordings of our own voices, but then can match pitch perfectly when mimicking a song?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi7bw70",
"gi7116n"
],
"text": [
"When you hear yourself talk, you are hearing your voice through the inside of your head, so it sounds different than other people listening or audio recorders picking up your voice. Just like if you grind your teeth or chew, it sounds different to you than what other people hear. Even though your voice sounds different to you yourself, you are still hearing the correct pitch and octave of your voice, so you are able to match pitch. It's not like you hear your voice at 2 notes lower or higher than it actually sounds. Your still hear the same pitch of your voice, it just sounds different, so you are still able to match pitch and carry a tune.",
"Because our voice sounds different when we’re hearing ourselves talk compared to hearing a recording of ourselves talking. When you’re hearing yourself talk, it’s coming from inside you so you’re hearing it through bone. When you’re hearing a recording of yourself, you’re hearing it how others hear it."
],
"score": [
5,
3
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
|
kr325u
|
Do tonal languages like Chinese also have “context” tone changes?
|
I mean stuff like sarcasm in English (when you can tell someone is sarcastic by their tone of voice), or emphasis on a particular word to change the meaning (“I never said *she* stole it” v. “I never said she *stole* it”).
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7y63h",
"gi7z46k"
],
"text": [
"yes, of course. for one thing, the idea that a tonal language means that tone changes are fixed is a total misunderstanding. pronouncing a character that uses the second mandarin tone doesn’t mean that you ALWAYS have to start between 300-380Hz and rise by precisely three to six semitones or anything like that. in fact depending on the tones of the words around it, it might not sound the way it’s written down in the textbook - the mandarin third tone is a particular culprit for this and beginners often make the mistake of exaggerating the dip. in the context of a long sentence, the only thing a tonal language speaker needs to do to make themselves intelligible is to make it not sound like the other tones. and of course the existence of singing in tonal languages should prove that people are pretty good at piecing together information even with a minimum of tonal context, so even if you miss a picture perfect tone here or there people can usually catch on. for another, tone changes also happen through the way you articulate your consonants, or through the length or volume of your syllables, which is totally unrelated to pitch. in my experience, these actually contribute more to stress than pitch does. in fact, the example you gave in OP is a perfect example for this—i don’t change my pitch at all to read out those sentences in english. so it’s silly to suggest that a tonal language wouldnt be able to make the same changes.",
"I don't know about other languages but in Mandarin chinese they have suffixes that change the meaning. In English we raise the tone at the end of the question, but in Mandarin at the end of a question you say \"ma\". For example if you say 啊 (ah) at the end of your sentence you're expressing surprise or excitement. If you add 吧 (ba) when telling someone to do something it makes it more polite and less like an order."
],
"score": [
4,
3
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[],
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|
[
"url"
] |
[
"url"
] |
kr3aux
|
what is essentialism?
|
I've looked it up, but apparently my brain is too tiny right now to figure it out...thanks for nothing wikipedia. My wife brought it up when I said I hated league of legends but felt the need to play it...She said its like I have to do something, even when I dont like it or I feel like I lose my identity. dunno.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7f89s"
],
"text": [
"Essentialism is, basically, the idea that every thing has an \"essence\" that makes it what it is, and without that essence it's not that thing. The \"essence\" is vague. Typically it's a set of traits that are unique to to the thing (a dog barks, so it is different from a cat, which meows), but sometimes is more intangible (e.g. the classic difference between pornography and artistic nudity is \"I know it when I see it\" - you just \"sense\" it rather than being able to define it). The thing about essentialism is that it's really reductive and typically not helpful in understanding the world or ourselves. Like, it's essentialist to believe that liking pink is part of the \"essence\" of womanhood, so *only* women like pink and *all* women like pink. In your case, you might think of yourself as a gamer and therefore \"must\" play certain games, and you're not a gamer if you play other kinds of games. But you don't have to play LoL if you don't enjoy it. There's no Gamer Essence™ that gets taken away if you think it's boring or not fun."
],
"score": [
12
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|
[
"url"
] |
[
"url"
] |
kr3bvb
|
Why are some scars purple, some white, some brown, some red, and some pink?
|
Pretty much what the title says. Why does scar tissue come in so many colours?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi78qwn"
],
"text": [
"Mostly due to age of the scar. As time goes by the scar heals more and becomes less inflamed, and color changes as a result. Severity of the injury also matters, and if you develop an abnormal scar like a keloid that will also cause discoloration."
],
"score": [
15
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kr3n7w
|
Why do people want/need representation in media?
|
I'm not opposed to it, more diversity means more stories, but I don't understand why people want to see themselves represented for their own sake (or for the sake of kids like them) or how it benefits them?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7avxu",
"gi7ag6e",
"gi7xshw",
"gi83lm8"
],
"text": [
"In every TV show that you watch, the hero doesn't look like you. Sometimes the villain does. In every movie that you watch, the hero doesn't look like you. Sometimes the villain does. In every book that you read, any characters that have physical descriptions aren't described as looking like you. Sometimes a character doesn't have a physical description, and you imagine that they look like you...then they're described later on and they don't look like you at all. How would that make you feel? After a lifetime of that, how discouraging would it be? Then one day, a big blockbuster movie comes out where the hero looks like you. You'd be so happy! Even above and beyond liking the movie, you'd suddenly be able to relate to it! It would be so exciting! That's why it matters.",
"If you've never seen an astronaut or anything about space, would you know that it was a potential career choice? We derive much of our inspirations/dreams based on what we see and the connections we make between different fields and phenomena. Representation is another form of that. If every single politician is an old, white dude, younger BIPOC might think that they don't have any chance of getting into that \"profession.\" This is self-reinforcing; no one thinks they can do it, so no one tries, so no one does it. Representation helps BIPOC or other minority demographics see a possible role for themselves in those parts of society.",
"Short version: Through media people (especially children and young adults) develop their understanding of the world and their place in it. Representation (good and bad) influences that understanding by dictating (explicitly or implicitly) how people act and what they can be in the world. Longer version: 1. Representation is an affirmation of a person's existence. A person who sees people 'like them' represented in media will (consciously or subconsciously) recognize that they're not alone. 2. Representation shows potential futures. A person who sees people 'like them' doing certain jobs or engaging in certain modes of behavior (or being conspicuously absent or barred from them) will, subconsciously or consciously recognize those as something they could be. 3. Representation shows modes of behavior. A person who sees people 'like them' engaging in certain behavior will, on some level, associate themselves with that and come to believe that's what 'people like them' do. This is similar to 2, but more general as it encompasses stereotypes about what 'certain people' do. 4. Media reflects reality and influences reality. Even if media is not a perfect representation of the world, it does contain elements of the world (which can be admittedly distorted), anxieties, fears, opinions, worldviews, desired realities, perceived realties, etc. Even if media is not real, and a person knows its not real, it does still affect them or others around them. Media, whether anyone wants it to or not, does influence peoples' thoughts about the world and reality. Children and young adults pick up on this stuff during their formative years (consciously or subconsciously) and it influences their beliefs and worldviews. That's why it's important for people - especially kids and young adults - to see people 'like them', because it shows them they're normal and that they have opportunities to exist and thrive in the world. If a certain group of people are only ever portrayed one way in media, people will inevitably (consciously or subconsciously) come to believe that's what that groups is like. If the poor black gay guy is always the villain...well, that does lead people (consciously or subconsciously) to associate those aspects (poor, black, gay) or their combination (poor, black, and gay) with villainy. Alternatively, if the rich straight white guy is always the villain, the same thing happens... Same if its an Indian woman with dyed hair, an indigenous nonbinary individual, an Asian trans person, a pit bull with a disability, a cat with a facial deformity, whatever.",
"Representation in the media is important because without representation, only one type of body/race (thin/white) is going to be shown to the public. When all people see are thin/white people, it makes all other people feel very different and marginalized. It makes people who don't fit that mold feel like there is something wrong with them. It makes it seem like everyone else in the world is a specific way, and that there is something wrong with being anything else. It plays into the horrible beauty standards that are accepted globally."
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|
[
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[
"url"
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kr41on
|
Where do national (?) accents come from?
|
So I understand that people from different countries will speak English differently. But how does it work with north / south of a country? Or even districts - like Brooklyn accent? In my country we don't have accents. Everyone speaks the same. How come in English people from Yorkshire speak different than people from London?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7e6q9",
"gi7hcko"
],
"text": [
"It's essentially the concept of biological evolution, but applied to language and at a smaller scale. Criteria: 1. Isolation: In evolution, this is separating populations either physically or through some other method that allows the populations to grow independently. Regional differences in language are geographically separated because the populations of people are geographically separated. 2. Time: Small changes over time add up to big changes. Now that the populations are separated, they will start changing slowly over time, but separately from the other populations. After a while, the differences may be very large.",
"What country are you from that has no local/regional dialects, and how many speakers does your language have? Languages are “living” constructs; meaning, pronunciation and usage changes to serve a purpose. A Brooklyn accent evolved because population of Brooklyn was different than the population of say New Jersey; different immigrant groups came at a different time, worked and communicated between each other, and by adopting certain forms and rejecting others, developed something that can be considered a local dialect. Unless you speak Latin and live in the Vatican, or are from Monaco and a native Monégasque speaker, I highly doubt your language has no regional differentiation."
],
"score": [
11,
3
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
kr4lq4
|
Why is the Finnish language so distinct from the other Nordic languages?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7gmj2",
"gi7hjbg",
"gi7gp0a"
],
"text": [
"Finnish is from a completely different language family. You can trace all Nordic languages plus German, English, Italian, French, Latvian, Russian and many more European languages back to a single “ancestor language” (Proto-Indo European) but Finnish, Estonian and Hungarian can’t be, they are from a separate language family and there is no connection",
"Many good answers already, but I'll also link the popular [language family tree.]( URL_0 ) It displays quite nicely that Finnish is not a language related to the Germanic ones.",
"Finnish belongs to the Uralic family of languages that includes other languages like Hungarian and Estonian. This group of languages traces back about 10,000 years. Swedish/Norwegian/Danish are all Germanic languages that trace back to a bigger Indo-European language family. Long story short, different groups of people sprouted up many thousands of years ago in separate geographic regions and developed their own language systems and then started migrating out around the continent."
],
"score": [
15,
8,
8
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"text_urls": [
[],
[
"https://www.sssscomic.com/comic.php?page=196"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kr4p7a
|
Why is it so much easier to open things when using your teeth?
|
Title. It's hard to open packets with 2 hands aka using your fingers even though they are grip machines. But put it in between your teeth and it's like magic. Why oh why?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7gs04"
],
"text": [
"> Title. It's hard to open packets with 2 hands aka using your fingers even though they are grip machines. But put it in between your teeth and it's like magic. Why oh why? Your teeth are made from the hardest material that naturally occurs within your body and your jaw is one of the most heavily muscled apparatuses within your body."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
kr4p9g
|
If gaining weight is simply the result of calories in and out, then why does taking certain medications (birth control, anti-depressants) commonly lead to weight gain?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi7h231",
"gi7hsm4",
"gi7p6mg",
"gi7gm7h",
"gi88fat"
],
"text": [
"Various hormones levels in your body will effect how many calories you burn while at rest(calories out). If you don't also alter how many calories you're consuming(calories in) you'll suddenly be consuming the same but gain weight because of the lower calorie out.",
"Usually it's because they change your body's regulation of hunger and satiety. Essentially you get hungrier and feel less full for the same amount of food from before. Some medications can also cause your body to hold more water that is would without that can cause minor amounts of weight gain.",
"As someone who gained... way too much weight... with COVID anti-depressants; they screw with your pleasure/reward system. So when eating a spoonful of Ben and Jerry's used to give you a shot of dopamine, suddenly you're binging a whole pint and not getting that reward. Multiply that by 6 months and suddenly your pants don't fit.",
"Gaining weight is mostly the result of calories in and out. Some medications can alter how your body processes those calories, making you more likely to gain weight. Others can cause you to feel more hungry than usual, so you are likely to eat more calories than you would otherwise. \"Calories in, calories out\" works for the majority of cases, but isn't an absolute rule with no exceptions.",
"A medication might cause you to gain weight if it: * Makes you hungrier * Makes you not feel full as long * Gives you cravings for sugar or fat, even if the volume of food you eat doesn't change * Makes you more tired, so you spend less time exercising * Fixes a problem that was preventing you from eating/digesting properly * Decreases your resting metabolism (lowering thyroid hormone for example)"
],
"score": [
25,
15,
10,
9,
3
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"text_urls": [
[],
[],
[],
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|
[
"url"
] |
[
"url"
] |
|
kr4y2s
|
since velocity is always based on a frame of reference, can I just change my frame of reference to have different amounts of kinetic energy? Where does that energy come from?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gi7iizg",
"gi7j24j",
"gi7iqhp",
"gi7jfcv"
],
"text": [
"If velocity, a necessary part of the formula for kinetic energy, is based on a frame of reference...then wouldn't kinetic energy have to be based on that same frame of reference? So if you change your frame of reference for velocity to get a different measurement, you have a proportionally equal amount of kinetic energy because it's based on the same frame of reference. You aren't \"creating kinetic energy\", you're changing the frame of reference with regard to kinetic energy.",
"Sure, but for that amount of kinetic energy to be meaningful, the frame of reference has to be something meaningful. Kinetic and potential energy are just accounting tricks, to show what *could* happen if two objects interact. Two racecars on a track are moving at 199mph and 200mph. If they bump each other, there isn't much of an impact, because the kinetic energy between the two of them is very low. But if one hits the wall of the track, it'll be a huge collision, because the kinetic energy difference between the car and the wall is huge. So you, sitting in your chair, have ludicrous amounts of kinetic energy if you consider that you're on the Earth, and the Earth is hurtling through space at thousands of miles per hour. But that's only a meaningful number if you want to talk about what'd happen if you collided with an asteroid or something. For the purposes of your daily life, your kinetic energy is very low, because you're just sitting in a chair. If you collide with something, it'll only be a low-energy collision.",
"When you change frames of reference, you change the problem. you can't compare the energy in two different problems in a meaningful way.",
"Yes and no. While not usually elaborated as such, the kinetic energy of an object is usually assumed to be in reference to something. For example, when car is driving on a highway, the kinetic energy of the car implies in relation to a stationary object on earth. But if you consider your reference point to be the Sun, then the kinetic energy of the car is much higher, because the velocity is now not the 100 kph, but more like 1600 kph. Or imagine two people in different cars driving parallel to each other throwing apples at each other. The kinetic energy of those apples is relatively small when hitting each other, but if you miss and hit an innocent pedestrian, he will be hit with an apple with kinetic energy much higher, due to combined velocity of the apple throw + velocity of the car from where the apple was thrown. Basically the resultant kinetic energy comes from the difference in relative velocities of two objects"
],
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11,
9,
3,
3
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|
[
"url"
] |
[
"url"
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|
kr55so
|
why and how is brining or pickling an example of osmosis?
|
I have a biology test tomorrow and I still can't understand the concept behind this and I think it'll come out on the test. I need help, badly.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi7klc8",
"gi7kcbf"
],
"text": [
"When you mix salty water and not-salty water, the salt gets distributed around so you get a bunch of medium-salty water. But what if you put a barrier in the way that salt can't get through? Turns out you still get medium-salty water. Since the salt can't get through the barrier from the salty side to the not-salty side, the water flows instead! The water goes through the barrier from the not-salty side to the salty side until both sides are equally salty. You end up with unequal amounts of water on either side of the barrier. That's osmosis. [This illustration might help]( URL_0 ) The skin of a cucumber is a real-life example of a salt-proof barrier like this. So if you put a cucumber in salty water, you get osmosis. The water from inside the cucumber will flow out through the skin, until the water inside the cucumber and outside the cucumber are equally salty. As the cucumber loses the water inside it, it shrivels up and shrinks, becoming a pickle.",
"Here's how I understand it and it works well enough for a home cook: Brine is a very salty solution. Because the solution is more salty than the brine, water is pulled out of the meat to try and even it out. But then \"oh noes, now the balance is off again\" so water along with the salty and other spices are pulled into the meat. This keeps happening until the meat and the solution outside the meat are similarly salty. Brine your turkeys people. Ain't nobody wanna eat your nasty Thanksgiving massacre."
],
"score": [
8,
3
],
"text_urls": [
[
"https://upload.wikimedia.org/wikipedia/commons/6/62/0307_Osmosis.jpg"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kr5qbt
|
How do candle wicks "keep up" with the decreasing wax depth in a candle?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi7negy",
"gi7ndrr"
],
"text": [
"If the wick is too long for the wax to reach the top, the wick itself burns. Once the wick is short enough that the melting wax can climb up it (via capillary action), then the wax will burn instead of the wick.",
"Well... They burn! How a candle works is that it melts the wax around it and the wax come throught the wick. Then if the wax is too far away the wick is burnt until the fire is close enough to melt the wax and the xycle keeps until there is no wax left"
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kr5s22
|
Why do astronomers consider everything heavier than helium to be a metal?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gi84kge",
"gi86p5m",
"gi873a9"
],
"text": [
"It's simple lazy label for ease of use. Astronomy very, very rarely has to worry about chemical reactions, which is when we need to worry about the properties of metals. The big thing is that hydrogen and helium make up a huge majority of what we can observe, so we need a simple catch all term for \"all the rest\" of the elements. And lithium is the first metallic element... So everything beyond that is lumped in as a metal. There is no real need in the field to make a finer distinction than that. The fact that it irks chemists is a delightful bonus.",
"Hydrogen and Helium were made in the big bang. (maybe a little bit of lithium) Everything else was made later by stars. Astronomers use metal as a term for elements that were not present at the start of the universe.",
"Most elements *are* metals. Everything on the periodic table to the lower left of a diagonal line from Boron to Polonium is at least arguably a metal. This leaves only around ~15 out of the 90 naturally occurring elements that are definitely nonmetals, so out of ~~laziness~~ a desire for simplicity they just call all heavy-elements \"metals\". Its close enough; just because we care about Carbon and Nitrogen and Oxygen more than average, doesn't mean that the rest of the universe shares our bias."
],
"score": [
21,
7,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kr5vy0
|
What is the point of options?
|
I understand that buying an option gives you the right to sell a certain stock at the strike price, but what is the point of this? How can you profit from guessing right, and is there any advantages to options that stocks don't have?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gi7punt",
"gi7pkzq"
],
"text": [
"> I understand that buying an option gives you the right to sell *Certain types* of options that is. Some give you the right to purchase stocks at a certain price in the future for example. > the right to sell a certain stock at the strike price, but what is the point of this? If the current price of the stock on the open market is less than the strike price of the option, then you can purchase the stock and sell it immediately at a higher price while pocketing the difference. The point is you make money. > How can you profit from guessing right Beyond the obvious situation explained above, options are also useful for something called \"hedging\". Basically they are mechanisms to avoid risk. If you are in a situation where you want to potentially profit from a stock you own going up in price but if it went below a certain price it would be disastrous, you could purchase an option to sell at a price just above that point. Now the maximum amount of money you could lose from the stock value changing is limited. > is there any advantages to options that stocks don't have? Again, in addition to the above situation of hedging you could potentially trade in options without tying a lot of money up owning stocks themselves. For example if we consider the situation where you purchase the option to sell at a certain price, betting that the stock will reduce in value, you don't have to keep a bunch of money invested in owning the stocks themselves in the interim. All you spend is purchasing the option and that is going to be far less than the cost of the stocks themselves.",
"An option is simply the \"option\" to buy at a certain price regardless of the current trading price. If the current trading price is higher than your strike price then you make money. If it's lower then you are known as being shit out of luck."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kr68rp
|
Why do stocks plummet after major events? Cant stockholders just “stay calm”?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gi7sk9g",
"gi7t05l",
"gi7ug9i"
],
"text": [
"Stock traders are predicting the future. When they think the future is certain, market fluctuation is reduced, and they can \"stay calm\". When they think the future is uncertain, the opposite happens. If they were to \"stay calm\" when the future was uncertain, they would be slow to react to things and they would lose their money.",
"It depends on what the major event is and what your investment objectives are. If you're talking about something like COVID, at the onset nobody knew how long it was going to last or how severe it was going to be. The Spanish Flu pandemic lasted over two years, should investors just sit tight for a few years while the market is depressed, or try to get into a safer, less volatile investment? Or something that is countercyclical? I think it would be easier to answer your question if you were more specific.",
"If stock traders are unsure of the future then they would prefer to back out of the market altogether and sell their holdings back into cash. This attitude of \"getting out of the market\" makes the supply/demand get all out of whack and crashes the price. But once they sell their stock then they can sit on the cash for a day, or 2, or 20, until they get a better idea of what the new landscape looks like and what the future might hold. Then they will repurchase stock as they see fit with that cash."
],
"score": [
4,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kr6mf3
|
What is the difference between an intel i5 and an intel i7?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gi7vy8a",
"gi7xsf6",
"gi7ufg0",
"gi7xpdu"
],
"text": [
"There are 4 classes of \"i\" chips, the i3, i5, i7, and i9. the main difference is the amount of \"threads\" and \"cores\" a Core is the brain part of the CPU. a thread is like the two halves of a the brain. when the CPU is told to do a thing, that thing is split into two \"threads\" one going down one half of the Core, and the other going down the other half of the core. an i7 has more cores, usually 4 (depending on the specific i7) and each core can split a thing into two halves. & #x200B; Therefore the higher number, the more the CPU can do at once, and faster the computer. USUALLY. There are things called Clock speeds that come into play, the clock speed is how fast the Cores can do the thing they are told to do. & #x200B; Think of it like a river. 1 river = 1 core. Just like a river can be split up, a CPU can be split up. The clock speed is how fast the river is flowing. A fast moving stream moves a lot of water, but a wider river moves more, even if its going slower. & #x200B; Hope that makes sense. =D",
"Surprised nobody has mentioned binning yet! Ideally, every processor Intel manufactures would be an i9, but inevitably there are defects in the manufacturing process. When a processor falls short of the quality standard required to be an i9, certain features are turned off (such as Hypertheading) and cores disabled and it is tested to see if it passes for an i7, if not the process repeats and it is tested to see if is an i5, then an i3.",
"The number and quality of the computing cores. An i5 has 4 cores and an i7 usually has 6 cores that can run at a higher clock speed (do more operations per second).",
"For a consumer: **i3**: \"General consumer level / mid-level\". Lowest priced, and for general computer uses. This is actually the \"right price to power\" option for most users. It being the lowest in the i-series is a bit misleading that these are still very powerful and are actually the mid level chip. **i5**: \"Mid-high level\" For general users and power users who are doing a bit more intensive tasks than your average user, such as gaming, complex business functions, or light video editing. Frankly, if you have a question if you may do tasks like this, its often a good idea to get an i5 over an i3, and prices usually aren't that much more. If you plan to play new games, at high settings you should get at least an i5. **i7**: \"Enthusiast level\" For a smaller segment of users that need extremely high end performance in specialized task or very high-end performance gaming. If you don't know what these tasks would be, thats a clear indication that an i7 isn't for you."
],
"score": [
19,
10,
5,
4
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kr7clp
|
How is the entire earth not covered in slimy mold and other bacteria?
|
It takes 3 days or less for some food leftovers or even just wet spots on wood in room temperature to start growing a good amount of bacteria all over it, so how is it that like all of the ground and other organic material out in the elements aren't completely covered in mold and algae after billions of years?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi8037q",
"gi884x4",
"gi886re",
"gi85n7w",
"gi824aq"
],
"text": [
"The earth is covered in microorganisms. On regular surfaces such as the ground, there is a limited amount of resources that support life. So microorganisms are there, just in lower numbers making it impossible to see them without a microscope. If you took a q-tip and swabbed a random surface and transferred it to a Petri dish with abundant food, you’d get a nice visible colony.",
"The Earth IS covered in bacteria. Every surface in your home probably is too. But don’t worry, most of it is harmless. Slime molds feed on decaying plant matter, so although they are abundant, they are mostly found in the soil.",
"It is. With the exception of some of the dryest and coldest parts of polar ice caps and very specially-sterilized labs, microorganisms coat every single square inch of Earth, from the highest mountains to the deepest trenches to the inside of your body. They're not thick enough to have a noticeable texture on a \"clean\" surface, but they're still there.",
"It is. They are everywhere. But other things eat mold and bacteria and there’s also the environment and things like weather...",
"Because other animals exist and environments are a thing. As you point out, you need wetness in order to grow these things, and the entire world isn't wet all the time. Mold can't grow just anywhere, it has to have particular conditions in order to survive. Further, other creatures eat the mold and bacteria and other creatures eat them in turn, and so on."
],
"score": [
11,
9,
6,
5,
4
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
kr8hk5
|
why is the G on an alto saxophone a concert B flat?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi8c4am",
"gi8cvnt"
],
"text": [
"It's to make it easier when switching instruments. All instruments are designed to be the best shape and size to complement their pitch and tone, but the tricky part comes when someone wants to learn a new instrument. If all music was in concert pitch and an alto saxophone player wants to pick up the flute or the clarinet, or even a different sax like the tenor or soprano, they'd have to re-learn which fingerings correspond to which notes, which gets pretty confusing. Instead, instruments are shifted away from concert pitch, and their music is written in their own respective keys. While this adds the mild annoyance of transposition, it makes it a whole lot easier to switch between instruments. What you'll often find is that a written G for an alto sax (concert Bb), a written G for a tenor sax (concert F) and a written G for a flute (which is concert G, as flutes are in concert pitch) will all have very similar fingerings. Check it out, looking at G on the staff: [Alto Sax]( URL_0 ) [Tenor Sax]( URL_1 ) [Flute]( URL_2 ) Three written G's that will sound as different notes, but which all have those three fingers down (plus an extra on the flute). Makes it really easy to switch between instruments and master them without having to re-learn a confusing amount of fundamentals. You can mostly learn the one fingering, and then just have to remember minor adjustments between instruments, because the music as written will always correspond to the instrument's proper key.",
"The reason the saxophone is a transposing instrument is so that it is easy for the player to switch between multiple versons, such as tenor and alto. Transposition means that the written note, G, is played using three fingers of the left hand on all saxophones. The fact that it sounds as a Bb on alto and baritone and and F on an tenor or soprano and a G on the rare C melody sax, is easier to manage than if the fingerings were different for the same written note. If they weren't transposing, to play a concert G the alto/bari player would play what is an E fingering and the tenor/soprano player would play what is an A fingering, so switching between them would require learning entirely new fingerings. Basically it makes it easy for the player to read music and more difficult for the composer who has to keep track of the transpositions."
],
"score": [
5,
3
],
"text_urls": [
[
"https://www.musikalessons.com/blog/wp-content/uploads/2017/02/sax-fingering-chart-final.jpg",
"http://westpointsom.org/wpsom_site/wp-content/uploads/2015/12/Tenor-Sax110.pdf",
"https://www.penders.com/images/Flute_Fingering_Chart.pdf"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krasmy
|
Why are some areas of the body more prone to dryness than other areas?
|
For example, my elbows, knees, and shins get dry often but my stomach, thighs, and neck are a lot smoother.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi93mmb"
],
"text": [
"Elbows, knees and shins have less oil glands than your stomach, thighs and neck. That oil is a natural moisturizer and creates a barrier to keep water in. Less moisture means dry skin, especially during the winter."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krb8l0
|
Why do 4k videos look better than 1080p on a 1080p screen?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gi8xalv",
"gi8ytu6"
],
"text": [
"If you're talking about online streaming videos (e.g. Youtube), the resolution isn't just the resolution but also affects the compression level. The 1080p version isn't a perfect detail 1080p video, it's compressed which adds some blurriness and stuff (but makes the file smaller). The 4k version is also compressed which adds some blurriness and stuff. The 4k version has more detail in it than the 1080p one, even after the compression does its thing. And a lot of the detail is big enough to see even after you shrink it.",
"It's due to the level of compression and higher bit rate. I always watch in 1440p when it's available on a YouTube video even though I own a 1080p IPS monitor."
],
"score": [
18,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krbj7d
|
how can octopuses and chameleons change colour?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi8utig",
"gi99kti"
],
"text": [
"Octopi change color by filling specialized sacs with pigments URL_0",
"[Veritasium made a great video on how chameleons change colors]( URL_0 )"
],
"score": [
3,
3
],
"text_urls": [
[
"https://oceanconservancy.org/blog/2019/10/07/octopuses-change-color/"
],
[
"https://youtu.be/SQggDnScsvI"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
krbulg
|
Can people really sleep with their eyes open? If so, how does that work?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9ipum"
],
"text": [
"Sleeping with your eyes open is definitely possible, and its called [nocturnal lagophthalmos]( URL_0 .) Most people don't even realize they do it, since it's just like sleeping with your eyes closed, except for the fact your eyes are open. So, there are no long-term or \"worth it\" benefits to sleeping with your eyes open. It can also cause dry eyes, restlessness, blurry vision, red eyes, light sensitivity, and the feeling of something being stuck in your eye."
],
"score": [
3
],
"text_urls": [
[
"https://www.webmd.com/sleep-disorders/sleep-eyes-open#:~:text=You%20might%20be%20surprised%20to,you%20sleep%2C%20but%20not%20completely"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
krbx9t
|
What happens in our bodies when we throw up that makes us feel so weak?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9825g",
"gi97s4a"
],
"text": [
"There are three main reasons. The initial weakness is because vomiting is a very physical act that uses up energy. If you went from sitting still to suddenly doing 10 jumping jacks your body wouldn't be prepared for the rapid increase in oxygen demand and you could get light headed. The second reason is caused by the dehydration and loss of electrolytes that vomiting causes. This doesn't happen if you vomit once, but repeated vomiting depletes the body of resources it needs. It begins a domino chain of events that overall weakens you and can cause various problems depending on individual electrolyte levels. The third reason is that whatever is causing you to vomit is also, likely, weakening you. The two most common reasons people vomit is infection or alcohol use. Both of these causes have their own negative effects on the body.",
"Well it depends on why you’re throwing up. I love to go fishing but I get sea sick very easily, so the first thing I try to do is throw up and once I do I feel fine, and there have been other situations where I’ve thrown up and feel much better. If you feel weak after throwing up it could be caused by whatever is making you sick, the emptiness in your stomach causing a feeling of uneasiness, or a genuine fatigue from the action of throwing up. The muscles in your abdomen have to squeeze your stomach hard enough to force the contents of your stomach up your esophagus and out your mouth. I imagine that that sudden burst of energy could be making you feel weak. Of course, there are always psychological aspects involved, and I can imagine the nausea associated with vomiting would make people weak"
],
"score": [
5,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krc1xi
|
Why are laptop batteries so much more durable than phone batteries?
|
I get that the battery is probably like 10 times bigger, but we all hear the "Don't use your phone while it's charging that'll ruin it!" But I've never once in my life heard the "Your laptop's battery will be ruined if you use it while its charging!" Please keep in mind I don't know much about technology so bear with me
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gi8y5yo"
],
"text": [
"It used to be the case. Battery memory was a big thing back in days of yore. Even in laptops. The materials are the parts that wear a little funny when you charge and discharge at the same time. Modern electronics, even phones, have more durable deep cycle batteries, and can withstand that behavior. That, coupled with smarter chargers that direct a portion of power to the device itself, on top of charging the battery, so this is prevented a second way."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krc3zs
|
Why does shipping cost way more for sending a package compared to when ordering something?
|
So if I am ordering something across the ocean, compared to me sending something to a friend across the ocean, I pay more than 5 times more for sending a package than just ordering something from the same place, and it's always like that. Do businesses get some special deal or something?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi8yohj",
"gi90vt7"
],
"text": [
"Business get discounts because they ship large volumes and also they will include a portion in the purchase price because even though you may not see a shipping charge there is no such service as *free shipping*.",
"Almost every part of the process that you're paying for, except the fuel, doesn't scale with the size of your package. If I ship a pallet or a single smallbox, almost all the steps are the same. But a pallet might contain 10 or 100 or 1000 items. All the cost for the paperwork, scheduling, tracking, people, etc. is spread across all those items. If you have just 1 item, you have to carry that entire cost on your one item. Taking it even farther, suppose I have one 100 lbs box that costs $100 to ship. If that box contains your one thing, it's going to cost $100 to ship. If it contains 200 0.5 lbs items it's \\*exactly the same\\* to the shipping company but it only costs $0.50 per item."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krcf93
|
Why did Vine shut down?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi91hcj",
"gi917so"
],
"text": [
"Vine didn’t allow its popular creators to make money and also didn’t really run ads So it wasnt making as much money as it could and neither were its creators. The big creators at the time line nash grier or Cameron Dallas began migrating to other platforms and eventually it was just too far gone to redirect",
"Competition and failure to keep up with the market. Other social networking services began creating their own short-video platforms/capabilities and marketers began leaving Vine and moved to Instagram, YouTube, and Snapchat. In particular, Vine did not provide for monetization of its videos."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krcpl7
|
how are VFX added to movies shot on film?
|
I'm not really sure how the shoot a movie on film then proceed to edit it / add visual effects and then release it. Digitally, for unprofessional people like me, we just take out the SD card, plug it into the computer, import the file into the software, do whatever then render it. When its shot on film, I don't get how they do all of that
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gi92c1k"
],
"text": [
"You scan the film, so that you have an image of each frame. Then you compute your VFX to line up with the pixels in the frames. Then you print your VFX onto film. Then you can use multi-frame printing to get film for the scene. Or you do the composition digitally and print new frames."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krcyak
|
why does pizza shop shredded mozzarella have better flavor and melt smoother than grocery store shredded mozzarella?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi95i8f",
"gi943tf",
"gi96x1l",
"gi9byy4",
"gi9472n",
"gi9bfem",
"gib6ht3",
"gi9xjac",
"gi9txk2",
"gi9ctg5"
],
"text": [
"I used to run a pizza restaurant and I think the main difference is that we shredded our own cheese. Low moisture part skim mozzarella that came in 5 pound blocks. Because it is freshly shredded, it doesn't contain anticlumping agents like cornstarch like preshredded cheese does.",
"Pre-shredded cheese comes with anti-clumping agents that stop the shreds from sticking together. It probably keeps it from melting properly.",
"[This video by Adam Ragusea]( URL_0 ) does a good job of explaining the difference between the cheese you can get at the super market and the cheese that pizza places use. It comes down to the content of water and oil in the cheese, and the cheese that pizza places use are sometimes only sold specifically to food establishments",
"Pretty much all pizza shop mozzarella is made by Leprino Foods, and is made specifically for pizza. It will have a lower moisture content so that it browns sooner, allowing the pizza joint to get more pies through the ovens in the same amount of time. Each major chain has their own specific recipe that Leprino produces for them, and then there's probably a generic one for everyone else.",
"You have to be careful about what you buy. A lot of grocery store mozzarella is low-fat or part-skim, avoid those, they melt like shit because of the low fat content. Also avoid fresh mozzarella, it's delicious and melts beautifully, but has too much water so it will make your pizza soggy. As for the flavor, many pizza places also use a mixture of cheeses rather than straight mozzarella, most commonly mixing in some combination of parmesan, romano, provolone, fontina, or asiago.",
"preshredded cheese often contains anticlumping agents that are not cheese. and part skim mozz is not as good as whole milk mozz.",
"First, if you want to be genuine, you shouldn’t use shredded mozzarella of any kind but you should use mozzarella di bufula. Thank me later 🙃 Most (mainly in America) use shredded mozzarella because it is cheaper",
"Look up Brick Cheese A Canadian Police Officer got charged smuggling it over to Canada as it is the best cheese for pizza..",
"Hold your cheese to a lighter. Cheese should melt and drip, not catch on fire. Whole milk over skim milk mozz all day IMO",
"My fix has been upping the heat considerably. Using wimpy heat that does the bare minimum of melting the cheese wont cut it, you gotta make sure all the heat goes to the cheese and not the crust too."
],
"score": [
117,
22,
15,
9,
9,
6,
4,
3,
3,
3
],
"text_urls": [
[],
[],
[
"https://m.youtube.com/watch?v=bxlet-gq4Ho"
],
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krdmkb
|
the reason we use silent letters in words and names?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi9fp0x"
],
"text": [
"Spoken language changes much faster than written language does. Many letters that are now silent were once pronounced, our spellings have simply not changed over the centuries. Some words are loan words from other languages, where the modern English pronunciation has gone through the same loss of sounds."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krdpl4
|
How are some infinities bigger than others?
|
This one has got me. I’m reading a book at the moment that mentioned very briefly that some infinities are bigger than others. The book is unrelated and the author dedicated all of one sentence to the fact - but it’s blown my mind! I’ve always thought (pretty sure I was always taught) that infinity just is. Something is infinite if it goes on forever, but how can something go on forever more than another? I’ve tried to google but I’m just not grasping it. How is it that one infinity can be bigger than another?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gi9drmu",
"gi99wfy"
],
"text": [
"There's a rule that set theorists use when talking about sets with infinitely many objects in them. They say that such sets are the same size if there exists some way to pair up members of one set with members of the other set so that neither set has any members left out. For every item in set A you could ever name, you should be able to name one, and only one, counterpart in set B, and vice versa. So one weird result of this rule, is that the set of positive even numbers, has the same size as the set of positive whole numbers (aka the natural numbers, or N.) You might initially guess that one is twice as big as the other. But you can easily come up with a rule between these sets which matches their members up so none is left out. For every member of the whole numbers, multiply it by 2 to find its partner in the even numbers. For every member of the even numbers, divide by 2 to find its partner in the whole numbers. When you can devise a rule like this which perfectly assigns partners to partners between two sets, we call this a \"one to one ~~mapping~~correspondence\", or a \"bijection\". Now there's a tricky question to ask: Between any 2 infinite sets, is there always a bijection? A mathematician named Georg Cantor proved that sometimes there isn't, using his now-famous \"diagonal argument.\" Specifically, he proved that there's no bijection between the natural numbers N and the real numbers R. No matter what scheme you might propose to assign every whole whole number a partner in the real numbers, you can always come up with more real numbers which are unpartnered. This means that the size of R is strictly greater than the size of N.",
"If you look at the set of Real Numbers (all numbers that aren't imaginary) vs the set of Natural Numbers (the countable numbers: 1, 2, 3, ...), they are both infinite, but the set of Real Numbers contains all of the Natural Numbers and more (the set of Real Numbers includes non-integer numbers such as 1.273, as well as negative numbers). So they're both infinite sets of numbers, but there's more Real Numbers than Natural Numbers."
],
"score": [
15,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krefc6
|
Why do we lose motivation to complete a task when told to do so, whereas we would have motivation otherwise?
|
Psychology
|
explainlikeimfive
|
{
"a_id": [
"gi9v4im"
],
"text": [
"It's not totally known. We know that this \"overjustification effect\" does happen, but why is something psychologists disagree on. It could be to do with the way that you perceive a task, and the kind of activity it is, the way you perceive *yourself* doing a task, or the way things you pay attention to or expect during the task change. Social context also seems to have an impact, so that being told to do something with someone else might produce a different kind of motivational effect than being told to do it alone, or being told to do it yourself in the presence of other people who aren't told to do it. So on the level of experiment there's quite a lot of variables to work with. Stepping back from psychologists though to my own introspection, I would say that motivation can sometimes be lost when I'm expected to do a task, that can be regained by making sure I have the ability to alter task parameters to suit my interests. Having confidence that I'll be able to do a task at my own pace, without later corrections etc. allows me to invest in doing something well without worrying that I'll be asked to do more than I'm comfortable with or undo something I'm proud of. Real control over your work is much better for motivation, and it can sometimes be useful to intentionally regain that by clarifying how much leeway you have, if you're doing something for someone else, so you can get a sense of comfort and confidence of being able to shift things around without interfering with whatever relational reasons lead you to do the task in the first place."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kreokv
|
how are nutrition labels made?
|
So I'm on a specific diet for surgery where I can not have any vitamin C at all. Why is it that something can have ingredients with vitamin C, but then on the label it says 0% vitamin C?? I just want to make sure I'm avoiding the vitamin.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi9f3cx"
],
"text": [
"Usually, it’s a non-active ingredient like ascorbyl palmitate. Explaining how labels are made might be too complex for what you need. What ingredients are you seeing that contain vitamin c?"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krf2zy
|
How come your appetite decreases when you are ill?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9hjvn"
],
"text": [
"Your body needs to rest so it can fight the illness. If you're busy moving about/looking for food you arent resting and your body is using extra energy to digest and breakdown your food. So, by not letting you feel hungry, you can comfortably rest and recover."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krf6ct
|
What does “power imbalance” mean in dating and relationships?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gi9jdsw",
"gi9ko5s"
],
"text": [
"When someone has some type of control over some part the other person’s life - that’s a power imbalance. The real issue isn’t during the relationship, but afterwards. The person without the power may feel like they have to stay in the relationship. For example: a professor and a student (professor can make class difficult for student or even alter student’s grade.) or a manager and a worker (manager can change person’s schedule or otherwise f*** up the worker’s job/pay)",
"Suppose we both work for the same company, and I have quite a bit of seniority over you. I think you're cute and ask you out, and maybe you even think I'm cute too, and you say yes. But now on the date, you're starting to think about how things might pan out if the date goes badly. If it's awkward and awful, are we gonna have trouble being around each other at work? If we need to start avoiding each other, maybe that means, because of my seniority, i start getting better shifts and you start getting shittier ones. Or maybe it even means, if I let a manager know I feel weird being around you, and the manager feels themself choosing between a senior employee and an entry-level one, that you're let go. I'm not having any similar such worries, because I know that, in the event of a conflict at work, I'd get the preferential treatment. So our date is a little bit weird. You have this motivation in the back of your mind to make sure things go nicely or at least amicably between us, and I feel much more at liberty to be myself, *even if* that means there's a little friction between us. You're laughing at my jokes even if you don't quite think they're funny, and I'm not doing the same for you. Maybe I even notice that you're going a littler further out of your way to please me than I am doing to please you, and I figure maybe this also means if I suggest some date activities which I'm eager to do but you might not be ready for, that you'll say yes anyway. And maybe I'm a little bit pushier about it than I would be if I had to worry about what this means for my job, the way you do. This is the kind of stuff that can happen on dates when there exists a power imbalance between people. Ideally, people on a date are working about equally hard to make each other happy, but power imbalances can tilt that equation in one party's favor. Edit: Ever watch *It's Always Sunny In Philadelphia*? In my opinion this scene [\"Because Of The Implication\"]( URL_0 ) is a great send-up of someone who is trying to set up a 'dating' situation with a huge power imbalance."
],
"score": [
11,
10
],
"text_urls": [
[],
[
"https://www.youtube.com/watch?v=kvT68l2wdM0"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
krf6d6
|
What does a journey to a destination, sometimes seem longer than the return?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9ilfe"
],
"text": [
"On the way there your brain is more focused on taking in the new stimulus, on the way home when it sees familiar surroundings it doesn’t make as many memories and zones out for longer periods allowing time to feel as though it passed faster. Youth is the same way. More days with new and exciting activities, more new contacts and things to learn. Once you get into the 9-5 grind time starts flying in retrospect."
],
"score": [
14
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krfikn
|
How are law enforcement agencies able to retrieve data off of a device or sim etc. that has been erased/deleted, yet we cannot retrieve our own lost data? Isn't the point of erasing something to completely erase it...
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gi9l7fv",
"gi9lk94",
"gi9m1ti",
"gi9o0ih"
],
"text": [
"You actually can recover it. You just need the right tools. It's the digital equivalent of the pencil trick, looking for fragments of data that may not have fully gone away, references in other files, etc that may help you rebuild a file partially. The way to fully make it gone is to write over it, with new files.",
"Deleting something doesn’t remove it from your hard drive. It marks the space that it takes up “free space” and when something else needs the space it will overwrite it. It isn’t until that point where it’s over written that it’s actually gone. As for retrieving your own lost data, you absolutely can if you have the right programs and know what you’re doing.",
"So, here's the best way I can explain this. When you \"delete\" something, off of your device, it's not actually being deleted. A programming function on your device is just choosing to ignore that particular data. If you happen to use that space up, however, it will be overwritten. Typically, devices don't have built in software to allow access to \"deleted\" files, but you can actually just download stuff like that. There's a ton of recovery software that exists out there. The main answer to your question, then, is that law enforcement agencies have access to very good recovery software. The recovery aspect of their software is the same as you yourself could get, but their software often has elements that can attempt to bypass security. That's why a lot of device manufacturers advertise their encryption technology, as it can help users feel more secure by attempting to block unwanted prying into your devices hidden files.",
"As others have said, you don't erase it normally, it's just marked as free space to write in. To completely erase it you need to write over it various times, shred the hard drive and then melt it"
],
"score": [
11,
9,
9,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krfvjo
|
Why do shots hurt?
|
Not the needle part, because whatever. But like...why does my arm feel like I got smacked with a baseball bat for a day after I get a vaccine?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9sjn0",
"gial5dg"
],
"text": [
"That's the vaccine working. The needle causes only very minor damage unless the person giving it to you REALLY screwed it up. The vaccine tricks your immune system into thinking it's fighting the sickness. The main thing is the production of antibodies so you don't get infected for real, but it also turns on a lot of the other things the body uses to fight a sickness. Stuff like causing the place to swell and to hurt, like you got a bad wound there. If it was a real wound, it would be the body telling you to not get the wound hurt worse, but your body can't tell it's not a real wound.",
"The key to making a vaccine is you want to trigger the immune system to respond enough to make memory cells of the virus you are presenting it with. You don’t want to make the person sick so you don’t use the real virus, but either a weakened version of it or just parts of it. If you weaken it too much or don’t use enough small parts, you won’t trigger enough of a response. If you don’t weaken it enough the person gets sick. So you’re introducing just the right amount of foreign particles for your body to think “somethings wrong here, I must do something about it”. And the response is an inflammatory reaction, which comes with swelling, pain, heat and redness (inside the muscle you were injected with so you may not feel/see it on the surface). All this makes your muscle ache when you move your arm until your body efficiently takes care of the problem"
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krh9o3
|
How am I able to read multiple pages in a book while simultaneously thinking of something completely different
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gibat6m",
"gibljiz",
"gibnrlf"
],
"text": [
"I'd like to know this too because I used to read books ALOUD to my students while thinking of other things all the time! It was like I had two brains. One that was reading out loud and the other that was planning lessons for 15 minutes later.",
"Unconscious multi-tasking. The brain actually has more processing power than the waking mind can use so with practice the brain can do things automatically while you focus on something else. People do this all the time without realizing it. Like walking and talking or when you remember something an hour later. Martial artists and some athletes train to do this since reacting without thinking is faster than reacting while thinking. Your brain can also analyze a situation and come to conclusions without your mind realizing it. It's where \"Gut Feelings\" come from.",
"Out of curiosity, are you also able to remember and comprehend what you just read or does it get buried in the unrelated thoughts?"
],
"score": [
7,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krhc4e
|
Why do we puke when we *see* something disgusting, although there's no sign it has actually entered or interfered with our body?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9xtr2",
"gia6lgv",
"gib83ip"
],
"text": [
"We have a very vivid sensory imagination, and it's pretty common that our bodies get their signals crossed a bit and respond in real ways to imaginary stimulus. For some of us, seeing someone get hurt badly can give us 'sympathy pains' in the same body part. For a lot of people, looking at or even *thinking* about a lemon, is enough to make their tongue and salivary glands tingle. It's the same with our disgust reactions. Neurologically, we don't have a super deep explanation for this, but we know that there are these things called \"mirror neurons\" in humans and many other animals, which fire both when we do something *and* when we see someone else do the same thing. We seem to have some part of our brain and central nervous system which is basically hard-wired for the purpose of imagining ourselves in someone else's place. There are lots of evolutionary reasons why this might be the case.",
"Well why is someone puking? Perhaps they ate spoiled food, or drank bad water. Now if you're a human living thousands of years ago, there's a pretty good chance that you ate the same food and drank the same water as your puking friend. *Maybe* you'd be fine, but evolution has decided that it's better to play things safe. Worst case, you need to hunter-gather a new meal.",
"I'd like to note something important: The neurologically machinery that causes you to vomit at certain stimuli has no way to know whether it's entered your body or not. It's not sophisticated enough to take into account your conscious memories. It's a (almost literal) knee-jerk reaction to the part of our brain that registers disgust being activated. As amazing as our nervous systems are, they're still very, very limited in many important ways. Much to the contrary of what \"Intelligent Design\" advocates would have you believe, we are very noticeably *not* the product of careful, deliberate design, but are in fact the product of the slow accumulation of whatever random mutations happened to turn out to be useful over the last billion years."
],
"score": [
39,
9,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krhjqs
|
Why did people start bathing every day?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gi9xxi6",
"gi9zzxc",
"giabk9n"
],
"text": [
"I mean a lot of people don't bathe every day. But I think that modern bathing practices evolved with modern plumbing practices. It didn't used to be easy for people to get this much fresh water, especially into their homes. and in many places it is still very difficult or impossible for everyone to have access to indoor plumbing. People used to bathe much less often and share bath water, but now we have the ability to take a hot shower whenever we want, if we are lucky. Showering feels nice, and in places where they are available it is expected to be smelling good because you have the option to smell good. I think people started bathing everyday for the same reasons that you bathe every day. It's expected that you be clean, and it's pleasant to do.",
"Because you will smell if you don't bathe regularly. Don't listen to the people who say \"but I don't smell and I only shower once a week.\" Yes, they do smell, they're just used to it. I wouldn't say showering literally every day is necessary (unless you workout and start sweating), but every other day at minimum. Furthermore, sex is much better when stuff doesn't smell (for both sexes.)",
"You'd have to ask an historian to know the real reason, but I have a few thoughts, which are probably not entirely correct: * [Less than 200 years ago]( URL_0 ) doctors didn't wash their hands before delivering babies. Slowly we started understanding how **dirty** can mean **diseased** * Body odor was accepted as part of life, similar to how we accept that cars emit smelly gasses. * Not everyone was rich enough to have access to plenty of water. As more people get out of poverty, more people can wash daily. * I think the Victorians started washing everything to differentiate from the poor. * Advertising, baby. Mouthwash was a very recent invention for something nobody had a problem with."
],
"score": [
10,
6,
3
],
"text_urls": [
[],
[],
[
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807775/"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
krhnab
|
How do compasses work and what are magnetic fields?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gia2ovg"
],
"text": [
"If you know what magnetism is skip the first part. First the basic of all this is magnetism. Magnetism itself is a quantum-mechanical effect and very complicated. It belongs to one of the \"four fundamental interactions\" of physics. It basically constitutes of negatively charged parts and positively charged parts, which attract each other. This effect can be realized through electricity, where electrons charge something negatively and the \"lack\" of electrons charges positive. That's called electromagnetism. Every magnet projects his attractionits out of its own body to it's surroundings, like gravity. The further away you are from the body the weaker the attraction gets though. That is the magnetic field. You can't see magnetic force, but when we lay down metal shavings they align themselves along the magetic field making it visible. The earth itself has an iron core that acts like a gigantic magnet, projecting it's magnetic force as far out as space. So the whole earth is covered in a weak, but constant magnetic field. Like any magnet earth has a positive side and a negative side, attracting the opposite. A compass uses that by charging on side positive, which then points towards the negative side of earthand the other side negative, which then points to the positive side of earth."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krigag
|
Apparently this decade has only just begun this year?
|
According to my girlfriend, mathematically the "20s" have only begun since the start of this year as of 01/01/2021. I'm open to the concept, as I googled it and it seems to be some kind of "school of thought" but I think she was doing a really bad example of explaining it to me, using examples such as the 1st floor of a building is the ground floor, technically. But that isn't really mathematical, because in maths you begin with 0 then, for example, 0.1, 0.2, 0.3 etc, but I'm not that confident of my maths skills as I've never particularly been that good. She also said because you go from 1BC to 1AD, there was no "Zero Before Christ" or "0 Anno Domini", but I argued that that is just where we decided the consecutive years begin from with the Gregorian Calendar, and isn't mathematical. Am I fundamentally mistaking what she means by mathematical? It was kind of starting to make my head hurt as according to that math, somebody isn't 10 years old until they've been alive for 11 years, which is what I said to her, and she said yes, then seemed confused herself. which is why I'm requesting an ELI5 from you guys, as from googling the subject, I've found myself quite interested in this concept but I'm massively struggling to wrap my head around it. Thanks :)
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gia4mbd",
"gia3dhh",
"gia3osv"
],
"text": [
"Your girlfriend is only correct in the most old fashions of terms. The 3rd decade, of the 21st century began in 2021. But the 20’s started in 2020. They use different convention. The first one uses the 1 to 0 convention. The second one uses the 0 to 9 convention. Nobody really uses the 1 to 0 convention for decades, only for centuries. This only really came back into living memory because there was controversy on when the 3rd millennium started in 2000 or 2001. And a lot of people were wrong in thinking it was the start of the 2nd millennium.",
"think about it what was the first decade? well the very first 10 years. year 1,2,3,4,5,6,7,8,9 and 10. Now what is the second decade?? the years 11,12,13,14,15,16,17,18,19 and 20. But do you see that? the second decade started in the year 11, the 3rd decade will start on the year 21. and sooo on until the decade we are in today that started in the year 2021 and not 2020.",
"She is wrong. If for no other reason than that it is commonly accepted that 2020 was the start of the decade and being the time scale is purely arbitrary, whatever the majority say is in fact the truth. If she wants to be technical than just say the the first decade only went from 1-9 and the second from 10-19 then Continued in that pattern."
],
"score": [
16,
14,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krigm7
|
What is electromagnetic radiation?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gia3ng3",
"gia3db2"
],
"text": [
"Two hundred years or so ago, James Clark Maxwell was coming up with a bunch of equations to describe how electricity and magnetism are related. During this, he came to a rather bizarre conclusion. He realized that magnetic and electric fields could actually self-perpetuate; they could sustain themselves without a nearby magnet or electric device. They could propagate as a wave, with no need for nearby wires or magnets. He also concluded that, in air, these waves would travel at 299,700,000 meters per second. This is electromagnetic radiation - an alternating magnetic and electric field traveling independently of a wire or magnet. Being a wave, this electromagnetic radiation can have frequency. When experiments showed that visible light also travels at this speed of maxwell's waves, it began to seem as if light was also this electromagnetic radiation, but at a much higher frequency (more waves per second). This is indeed the case.",
"Colors of light that we can't see. Some of these colors are really good at going though objects, kind of like when you can see a flashlight under a blanket."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kriik7
|
How do countries get out of bad economic situations? Like if a country has no resources, money, etc. how can they get out of that situation?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gia3fcp"
],
"text": [
"can you give an example? every country has resources. the situation you're describing doesn't exist."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krixmx
|
What's happening when your body is dead tired but your mind is like a toddler on a sugar high?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gia82wv",
"giaxcrz"
],
"text": [
"Your stress hormones are kicking in. Your mind thinks it need to get you bodies fight or flight system going to get itself out of danger.",
"Not necessarily stress hormones... Adhd will cause it too. The brain shifts between thoughts or scenarios and can't settle down to \"power saving mode\". Sometimes redoing your \"bedtime\" routine will get the brain inline, sometimes just getting up and doing something...drinking water, trip to bathroom, sit on couch in the dark for 5 minutes will work. Sometimes watching tv for 5 minutes, youtube video.... Basically something to distract your brain from it's \"cycle\" and get it to focus on a single thing, then it can follow the bedtime/sleep process. If you find yourself worried about tasks or something you don't want to forget that can cause an adhd brain fits...keep a notebook and pen nearby... jot down the important thing(s) and your brain will likely stop stressing and sleep. I have decades of experience with this ...sometimes months of insomnia until morning and catching up on sleep on weekends... If it happens alot talk to your dr about it. Several pharma options. Start with melatonin and Benadryl (Diphenhydramine) for occasional otc."
],
"score": [
72,
21
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krjbx1
|
what is the reason for REMASTERING old songs? Is that due to the newer and more advanced sound systems?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gia9bs2"
],
"text": [
"What has been already said, but exactly the reason why you think it woukd happen. Older songs that are extremely popular compared to ones that arent will get more album and singles sales. With the new advancements, of course the music industry is going to make a remastered version, so it can sound better or at least more crisp and clear to generations that aren't used to the old sound. The incentive is of course money, but you don't see just anyone remastering songs. Now that we have the technology to do it, of course it is going to be done. People will listen to a clearer sounding track or pay for a service or buy the song for it to add to songs that are newer. If the track was kept the same, then people might not listen to it as much as a newer song. TLDR making use of new technology as well as trying to keep the business going"
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krk6oq
|
;How can http transfer video, audio and files not containing hypertext when it is a 'Hyper Text Tranfer protocol'
|
The wikipedia for http says ``` The Hypertext Transfer Protocol (HTTP) is an application layer protocol for distributed, collaborative, hypermedia information systems. ``` I searched the word hypermedia and it seems to be the extension of hypertext to include video, audio etc. But nowhere in the wikipedia it says that HTTP transfers hypermedia instead of hypertext. It just says that it is used for hypermedia information systems. So shouldn't the full form of HTTP be Hypermedia Transfer Protocol ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"giac8wa",
"giacl8a"
],
"text": [
"Are you asking how it actually works to transfer audio and video over http, or are you asking why the name is what it is?",
"Because while it's original purpose was to only transfer text, it was extended to support other formats, but the name remained. We also use HTTP today for things like web services which are far from hypertext. As for how it actually works, the server's response includes a \"Content-Type\" header which says what kind of content it is serving, such as \"text/html\", \"image/jpg\", \"audio/mpeg\" and \"video/mp4\". It also includes another header \"Content-Length\" which tells the client exactly how long the response is. Alternatively the response can be in \"chunks\" where the server sends pieces of the file, with each piece preceded by its length."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krlo2q
|
how does the ant on a rubber rope work?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"giajphp"
],
"text": [
"So, the idea with the puzzle (going by the version on Wiki) is that the ant is on a 1km rope walking at 1cm/s, but the rope gets stretched at 1km/s. It seems like the rope is always getting more longer than the ant has to walk, so that ant should never reach the end. The problem with that thinking is that the ant gets dragged along when the rope stretches. How far the ant gets dragged depends on how far along the rope it is. Imagine the ant finally gets to be 1cm from the end of the rope. But now the rope stretches by another 1km. Does that mean the ant in now 1km away? No, because the rubber that is under the ant gets pulled too. This would mean the ant is still about 1cm away from the end. Hopefully that'll get you started on the idea. And if not there's a [Vsauce2]( URL_0 ) video on this exact riddle!"
],
"score": [
5
],
"text_urls": [
[
"https://youtu.be/OM9KepKsg6U"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
krlvhs
|
why does the point of a laser look pixelated when spread out?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"giamylz",
"gibjyka",
"gib30cr"
],
"text": [
"The thing about laser light that makes it special is that it's 'coherent', which means it's all coming out of the emitter at the same frequency and phase. But once it leaves the emitting element, it passes through some stuff. First, usually, a little bit of transparent plastic which is part of the laser diode package. Then, possibly, a bit of glass or plastic optics meant to bend or focus the light. Then some air. Each of these transitions bends the light beam a little. This means that different photons might be leaving the same spot on the emitter, and landing on the same spot on the wall (or whatever) but they travelled along different paths in between. If those paths are not exactly the same length, then that means the photons are no longer guaranteed to be in phase with each other. If they are in phase, then they interfere constructively and are brightly visible. If they are out of phase, then they interfere destructively and will cancel each other out. [a little diagram of how constructive and destructive interference works]( URL_1 ) The speckled, mottled pattern you see around a laser pointer dot, is the result of those photons following slightly different paths and messily interfering with one another. That principle - light from a single source travelling different paths and interfering with itself - is basically the same phenomenon they were exploiting in the [Michelson-Morley experiment,]( URL_0 ) which demonstrated some important facts about the speed of light and helped to confirm Einstein's theory of relativity.",
"In a laser, the light is all the same color and all lined up. When it hits a rough surface the light waves can either add up to give you bright spots or interfere to give you dark spots. & #x200B; It is called speckle noise, and it is fascinating.",
"Going with the wave model of light, compare each bright speck of light the the tip of each wave on a body of water under \"choppy\" conditions. When the waves are regular and all coming from the same direction the top of each wave would be a line. Once the waves bounce off an irregular shoreline or rocks they start interfering with each other until no perceptible waves just thousands of random peaks. Regular orderly waves are what is emitted by any laser but the wavelength of light is so short that there is no surface smooth enough to avoid acting like a rocky shoreline to the laser."
],
"score": [
28,
3,
3
],
"text_urls": [
[
"https://simple.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment",
"https://cdn.britannica.com/07/62907-004-A3A6351E.jpg"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krmyyi
|
how do archaeology digging not damage artefacts or fossils?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"giauhle",
"gib58rh",
"gibghy0",
"gibjgwx"
],
"text": [
"Initial discoveries can be made by normal construction activity that obviously is done with excavators and shovels, but when archaeologists are digging in an area known to contain artifacts they do their preparation. Dirt layers build up over time, so when something is uncovered say 3m underground they will look at the layers above in the area already exposed to see what was going on during those periods and if it is of interest. After checking a number of spots they gain confidence that indeed the area of interest is covered by 2m of overburden and they can use equipment to remove that material more efficiently than the hand trowels, brushes, and fine picks used for the delicate work.",
"Scientists use ground penetrating radar and sonar as well as geology to get estimates on how deep the site is. They then go through all the material with a fine tooth comb as they dig and switch to very delicate methods once close to where the artifacts should be.",
"There are many techniques that can be loosely categorized as invasive (using an excavator), minimally invasive (manually troweling) and noninvasive (ground penetrating radar). The selection of excavation technique depends on the initial information gathered about the site locality and what is feasible for the project in terms of money and time. Different archaeologists in different areas of the world have different excavation preferences based on their research topic and geographical area. Mistakes unfortunately do happen, but when the research is important to society, it is unusual that the artifacts are not handled with care.",
"There are layers in the ground called strata, and we usually know which one we're looking for. So if you're looking for a load of burials, and there are 3 strata, you know that layer 1 is soil, layer 2 is pebbles, and layer 3 is clay. The people lived before the soil, so they lived on layer 2, but they dug the graves deep down so the holes for the people will be in layer 3, so you can remove all the soil and some of the rocks with a digger and then be really careful with the clay layer. Saying that, on a dig in Spain, the first hit with a pickaxe into the top layer shattered a burial urn, the head archaeologists response was just \"that's what glue is for!\". Once you find the right layer you do everything super slowly. So when I found the edges of a burial hole with my shovel, I dug with a tiny trowel and brush, and every inch or so was photographed and cataloged, so you couldn't do any damage. All of the dirt that was dug out was inspected and even tiny bone fragments were sorted and kept. Usually diggers are used to remove all the layers that people have already messed with. Farmland has been plowed to a certain depth, so you know everything up to a certain point has been disturbed anyway."
],
"score": [
17,
7,
4,
3
],
"text_urls": [
[],
[],
[],
[]
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|
[
"url"
] |
[
"url"
] |
|
krn06v
|
How are electric fences "safe" considering the high voltage? And why is the high voltage necessary?
|
I understand basically that the current, or amps, are what cause harm, but based on Ohm's law, V=IR, for the amps to be so low with such high voltage, the resistance must be very high. So why do you need such a high voltage in the first place? Wouldn't that require a transformer to step up the voltage? And doesn't such a high voltage create a safety risk, for instance if a conductor with lower resistance came into contact with the voltage source? Or arc flash? If you want low amps as not to electrocute animals/people, would it not be easier to use lower voltage? Just curious and trying to understand. Electricity is like magic to me.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"giaqp00",
"giav33q",
"gib1hcg",
"gib1gv9",
"gib3fnq"
],
"text": [
"You have a correct understanding of ohm's law. We need high voltage *because* the resistance of people and animals is so high. A lower voltage would not produce any meaningful current and then we wouldn't feel it. It may need a transformer or it uses an inductor (half a transformer) to boost the voltage using a DC-DC converter. If a conductor with a lower resistance touches the wires then it could start a fire. A good shock device should have the ability to detect when it is touching a low resistance object and either limit current artificially or shut down.",
"> And doesn't such a high voltage create a safety risk, for instance if a conductor with lower resistance came into contact with the voltage source? Just pointing this out: An electric fence is not, by nature, a safe device. It's designed to hurt people/animals. You can try to design something to hurt people in as non-permanently damaging a way as possible, but it's never going to be as safe as not hurting them in the first place. It's just like a barbed wire fence. Something can't be harmful enough to be a serious deterrent without also carrying some risk for serious injury.",
"It is not voltage that kills, it is current that kills. Static electricity, what you get from dragging your feet across carpeting or not using a dryer sheet, can be 10,000 volts or higher. It can also hurt when you zap someone or touch a doorknob. It is not dangerous because there is no amperage (current flow). An electric fence is much the same. It is high voltage, but there is very little current available to flow. Think of it as a water pipe with 10,000 psi, but only a trickle of water is available. A little less simple: you need to use P= I*V when dealing with transformers. You cannot have a higher P on the output than on the input. If your input is 100v at .1A (10w) and your output is 10,000v, you cannot produce more than 1mA Even this assumes a perfect system. In reality, you will have losses in the transformer. Edit: to whoever down voted me: learn more about how transformers work and why Ohm's law is not the correct formula to answer this question.",
"The biggest reason they're not lethal is that they have a very short duration pulse. Even with very high voltage the total amount of *energy* is miniscule.",
"Practical explanation from a sheep rancher: the voltage must be high because the resistance *is* high. Sheep in particular are well insulated, and the return path for the current (the ground) is often dry. Hard dry hooves on dry ground and a wool covered animal make hard conditions to deliver a shock. Here's the electrician part of the explanation. Fence wires are long and cheap, made of high resistance steel. When transmitting power long distances, you lose power to the resistance of the wire. This power heats up the wire. P=I squared R. Notice how voltage is not in this equation. Now P also = VI. So to deliver the same power over a long wire without losing as much to resistance of the wire, you increase the voltage and decrease the current. So even for easier to shock animals, you want high voltage to cover the miles of fence. The reason the fence charger is safe is because the *energy* is limited. It is delivered by capacitor discharge. The capacitor is a little energy tank that can deliver high power for a short time. It fills up the capacitor and then delivers that energy to the fence. This is what makes the ticking sound you hear from a fence charger. My fence charger has an **18 joule** capacitor. So no matter what touches the wire, it is getting a maximum of 18 joules of energy delivered to it."
],
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18,
10,
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4
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"text_urls": [
[],
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|
[
"url"
] |
[
"url"
] |
krn2uk
|
what is/causes airplane turbulence?
|
I know I could easily google this question myself but I’m worried that the answer might be something that causes me to be afraid of it when I experience it in the future. Much like when you’re sick and google your symptoms and it jumps to cancer, I don’t want to google this and learn that every time I’m in a turbulent plane I’m likely going to crash and die. So I thought if it’s explained to me like I’m 5, I’ll get a straightforward answer but one that also assures me that there is no need to be afraid of flying either.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"giaq9fg",
"gic23jp"
],
"text": [
"Turbulence is just regions where the air is moving up or down and sometimes all around. There are situations where there is a large column of air that is all moving down and the plane can fly into this and feel like you are falling (because you are) but it never lasts long enough in one direction (up or down) to cause any issues. Also the plane can compensate when needed. It just feels scary but a plane has never been brought down by turbulence. The only danger is things inside the plane hitting you which is why they always ask you to put things away securely and wear a seatbelt. You can think of it as being exactly the same as a bump in a road. edit: anger-danger",
"Sun heat ground. Ground heat air on top of it. Hot air go up. But not all ground heat air at same speed or intensity. So some air go up fast but some go up slow. That creates the bounces we call turbulence. Fun fact. Fly low in a smaller plane over the ground and get rocked by turbulence. Take it out over a large lake (Great Lakes or ocean) and watch the turbulence magically disappear bc that ground (water) will heat uniformly thus heating the air uniformly."
],
"score": [
30,
3
],
"text_urls": [
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
krn8bg
|
why do we see things in the corners of our eyes when there’s nothing really there?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"giasbxl"
],
"text": [
"Vision in the peripheral is built to detect movement, your brain interprets input and this is what you “see”, especially related to danger. From time to time, a specific set of inputs are mistaken for something else and you then “see” something out of the corner of your eye which is in effect a prediction that later proves false."
],
"score": [
5
],
"text_urls": [
[]
]
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|
[
"url"
] |
[
"url"
] |
|
krnah4
|
Why do some apps stay open when you leave for 5 seconds but others take you back all the way to the starting screen?
|
Edit: Inspiration came from the Minecraft and Roblox app lol.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gib3aks",
"giasusd",
"gicf34s",
"gib4fve",
"giarcu2",
"gidaif3",
"gibj2e1",
"gibw2w7",
"gibkklc",
"gibm26w",
"gic6nfg",
"gib54xe",
"gibi59c"
],
"text": [
"Imagine that apps are litte robots in your phone. They are all asleep in little bunk beds. When you launch an app, its robot wakes up and starts talking to you. When you switch to a new app, the old app’s robot now has nothing to do. On big phones, there could be room for two app robots to be awake at the same time. On small phones, there’s only enough room for one robot at a time, so the old robot goes back to its bunk bed and goes to sleep. Even on a big phone, the robot might get bored with no one to talk to and put itself to bed. When you launch the old app again, its robot wakes up, but it’s forgotten everything it was doing so it has to start all over from the beginning. But smart robot makers know this makes users sad! They give their robots a litte notebook, so when they go to sleep they can write down everything they were doing. That way, when they wake up, they can look at the notebook and remember just what to do to pick up where they left off. It is a little more trouble for the robot maker to teach the robot how to use a notebook, but it’s so much nicer for everyone if they do.",
"I don't know about iOS, only Android. The simplest case is when your phone has enough ram to work with that your previous app can stay open in the background. Basically what happens is that Android tries to manage your phone's resources (CPU, RAM, battery life etc.) as efficiently as possible. This means that sometimes it has to stop applications that are running in the background to make space for the app that is currently in focus. Also, Android provides the possibility for apps to not outright close, but to be put into a hibernated state. Think of it like freezing the application and saving it like you would save a file. When you open the app again, the app is defrosted and you can continue where you left off, giving the impression that the app was running in the background all along. In most cases having this hibernation in an application requires more work from the developers. If they decide not to support it, the app will just close, that is why it takes you back to the start screen. tl;dr: your phone might have enough ram to have multiple apps running in the background, or the closed app's state is saved to storage, which is loaded again once it comes back to focus",
"As an iOS developer I can tell you the reason for iOS with absolute certainty: apps which use the least memory are killed last by the OS. When your phone needs more memory, it asks every app to free some memory. Those that don't free enough when they're using a lot are terminated. As a result, some apps stay open indefinitely because they are hardly using any.",
"In short, this is called Tombstoning, or \"\"remember the apps last known state.\" The phones provide a means to tombstone (iOS, Android). However, it's up to each application developer to *actually write* the code to save, and restore, the state of the app. Leave a low rating for the app saying as such. Either you have a good developer, that does this or will listen to ratings. Or, the app dev doesn't give a frack and does whatever. It will show you the quality of the app you are using (and makes you wonder what else is wrong with the app).",
"It depends on whether or not the creator of the app programmed it. For security reasons, some apps have an automatic logout when the app goes to the background. Others might keep an open connection when it's pushed to the background so you can continue where you left.",
"As others explained, this is due to the app being in RAM but this memory is limited and unused apps are put to sleep or unloaded when not in use. I like to explain it as having an office with a desk and drawers for archival. The desk is your RAM: It's where you put documents or stuff you're currently working on. Having a bigger desk is like having more RAM, which means you can switch between various things at the same time. Sometimes you run out of space in your desk, either because it's small or you're working on too much stuff at the same time. So you (the operating system) need to store one or various documents in a drawer for later use. Obviously you'd want the least or oldest used document out of the way, while keeping in the desk the most recent stuff so you can keep working on it. This is why you can put some apps on the background for a little bit, like answering a message and coming back, but if you leave them in the background too long the app needs to reload everything it had: the app got sent to the drawer AKA \"put to sleep\", and getting a big document out of a drawer (loading the app's data which got unloaded) is time-consuming and slower then just having the document on the desk ready to go",
"Modern phones should not have this issue. They have enough RAM to cache whatever app you're using and should let you get back to where you were upon reopening it. The fault lies with manufacturers' intrusive \"battery optimization\" which kills background apps to save battery. On my Huawei phone you can't even turn it off, the option to do so doesn't do anything. URL_0 Here you can see the worst culprits of this horrible practice. Avoid these brands if you want a nice phone experience.",
"Because the product owners won't allow me time to address the technical debt and allow caching app level state on global re renders",
"YouTube: You were 4 seconds into this interesting video and switched apps...let me just refresh when you reopen. Also, you were two minutes into this other one but got distracted and 7 hours later when you open it up, I'm still paused! Seriously...it makes no sense.",
"When an app starts from scratch, it usually means the app lacks the ability to go to the background, meaning the app eats too much power or somehow uses too much resources to stay active. The Devs would have to do extra work to facilitate the background-ness of the app",
"Android has a custom memory management. It's not the same as Linux memory management, which also exists on the lower level of Android OS. The Android memory management is a set of memory rules. Privileged users (or manufacturers) can set these rules of how much memory can you use while the app is shown, the app is in background, the app is not really doing anything, etc. When the criteria are crossed, Android will close one of your apps. iOS and others may be different, but they need to have background process support, so it's likely that their ideas are not far different.",
"Android OS (and likely iOS too) will tell an application when various things are happening, like when the screen turns off, or the phone is turned sideways, or the users switches to another app, or when the user switches back to this app. The developer can write code to then do something when these triggers occur. Typically this would be used to save the current application state (like what screen you were on, what text you already entered into a text field, etc.), or to automatically pause a game, or to restore the state. If the application doesn't do these things then the developer is ignoring these triggers events coming from the OS. TL;dr it's a bad or lazy developer.",
"No clue about Android, but for iOS: When you switch apps, the previous app goes into a hibernation mode and most of the time if you switch back immediately, it will still be around and ready to wake up immediately right where you were. However if the system starts to run out of memory, it will start killing off hibernating apps. The rules that iOS uses are not straightforward or made public, but generally speaking apps that use less memory and are used more often get to stay alive longer while heavier apps and those that haven't been opened for a long time get killed right away. Beyond that, some apps will save their state before they enter the background and even if the app gets killed, will relaunch to the same spot when you reopen them, albeit with a bit of a delay. However, since phones have gotten more memory in recent years, fewer and fewer apps are bothering to do this since 9 times out of 10 (especially for employees who use the app regularly) the app is still in memory when it gets relaunched. Additionally, in recent years Apple has made some changes that cause apps to get killed more aggressively if they cross some undefined line in the sand. A lot of really great apps have had issues getting killed in the background for violating undocumented policies (like taking too long to download a file or not responding to an api correctly) and have just started to figure out how to avoid that."
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|
[
"url"
] |
[
"url"
] |
krngqn
|
how can this storage tank appear to be towering over everything from more than a mile away, but when next to it appear to be just a normal structure?
|
[Image]( URL_1 ) [Location in Google Maps]( URL_0 ) It’s Florida, Tampa Bay port area, so terrain shouldn’t be a factor?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gias8p9"
],
"text": [
"The buildings that look taller than it are closer to you than the tank is in the second picture. If they were right next to the storage tank, it would still tower over them."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krp4q7
|
Why do televisions randomly crack at night when we’re in bed?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gib1zjk"
],
"text": [
"The same reason houses creak and groan: things shrink and expand when the temperature rises or falls"
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krpqt3
|
How does crypto currency (Bitcoin) have actual value?
|
I'm trying to get a better understanding about this area, but when I Google and try to read up on it, most of the information is written with the assumption you have some understanding in this area. How is crypto currency any different than an in game currency? What real world value does it have? Also, what is Bitcoin mining? Someone was talking about it the other day and made a passing comment that made it sound like you were...finding new Bitcoin? Like literally mining for more? Sorry if this is really dumb or obvious lmao but it's confusing the hell out of me 😂😂
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gib7y40",
"gibd0uz",
"gibbyjo",
"gibp50x"
],
"text": [
"Scarcity and demand. People want it because of the perceived value of it. The supply of bitcoin is limited: only 6.25 btc are added to circulation every 10 minutes (approximately)",
"It looks like there are a few good explanations of why it has value (because enough people accept that it does) As for the mining question. As I understand it, there is a process by which you can use computing power to solve specific math or computer problems. I'm not sure of the details, but these calculations count towards a certain percentage of a bitcoin. There are controls in place (blockchain?) That verify that you have done the required work and thus you are granted a coin or a percentage thereof. So 'mining' is just shorthand for 'ran the required computer processes to create a bitcoin'. This required effort is partly what gives them value - they are limited in number and someone can't just 'print' more bitcoin. As for Blockchain technology. I don't have a good understanding of it, but it's a security feature that contains the transaction history of each bitcoin so you can prove its legitimate. Each bitcoin has a blockchain attached to it.",
"The value of bitcoin (and crypto in general) is in the fact that there is an economy that essentially accepts said crypto in exchange for goods and services. In particular, vendors that accept crypto often *prefer* crypto over other means of payment because they deal in goods and services that are of questionable legality in various parts of the world.",
"That's the thing, it doesn't, its just perceived value based on what they think it may do in the future. Remember back when everyone thought hashing and crypto farming were going to be IT, dropped $3500 on a bunch of 1070s and 1080s? Yea those guys had to sell those off at a loss. How much faith would you have in our $1 bill if some days it was worth $33 dollars and the next day you go to the store to get food and it's was worth $0.60. You go home, wait a day and it jumps back up to being worth $12, then the next day its worth $1.20. Until this is a universally recognized currency, buying and selling Bitcoin is no different than day trading stock. You hope to buy it low, and it go up, but risk buying at what you THINK is low, then it drops even lower, or you get lucky and it skyrockets and you sell before it plummets again. Its very volatile, hence why its ranged from $0.50c per coin to $33,000 per coin. You could buy 1 BTC for $6000 and sell for $30,000, or buy in for $12,000 and it drop back to $8000 in 48 hours. Its not backed by anyone, like a government so at any time, every single person could lose 100% of their investment instantly. Potentially. People have fun taking risks, we get a dopamine squirt to the brain when we do, same thing as pulling a slot machine or playing routlette. As far as BTC mining, you are using usually a string of graphics cards (due to the incredibly fast memory to hash out chain links). So what happens in layman's terms is, there is this HUGE math problem/algorithm and its only getting bigger, when your machine you are farming on, solves part of the chain, you get paid for your work and that link gets added in, then everyone else starts working on solving the next link in the chain etc etc. That is why people have stacks of 50 graphics cards linked together running 24/7 solving more of the equation than the previous person, and they get paid more for it. What is the equation they are solving you ask? Oddly its the proof itself, the bitcoin chain, the entire huge thing, is basically a large encryption key, which is keeping everyone honest since nobody has solved all of it solo, nor will they ever, you just basically are proving with math that the bitcoins exist and are proofing everyone else's work."
],
"score": [
13,
11,
10,
6
],
"text_urls": [
[],
[],
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[]
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}
|
[
"url"
] |
[
"url"
] |
krq3f2
|
why do the bugs always go to the light?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gibe3kq",
"gib83z7"
],
"text": [
"Imagine being a moth before humans. At night, the only light source should be the moon. For our little moth friend, this is a great tool to help them flutter about to do moth things. Using the moon as a beacon, and moving around with respect to its position. Now enter, the glorified apes. We decided the moon wasn’t enough for us, and bedtime was never going to win. So we invented ways and means of generating our own light 💡 So now, when the moth tries to move about and do its little mothy business, it still tries to navigate using its old dependable lightbulb in the sky. Except now there are lots of light bulbs, and they’re moving much quicker when it flutters about, since they’re closer. So the moth can get very easily lost and confused in the noise, and doesn’t realise that’s it’s no longer following its age-old landmark. Poor little guy.",
"Because nocturnal insects developed the ability to navigate by the moon and artificial light confuses this built in mechanism, causing them to be attracted to the brighter source."
],
"score": [
14,
4
],
"text_urls": [
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
|
krr105
|
Dermatology question. Why does sunburnt skin thicken and peel?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gibelqu"
],
"text": [
"Ultraviolet light can damage DNA. When cells (including skin cells) detect their DNA is damaged the cells die. So a sunburn literally kills a bit of your skin and your body is responding to that."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krr2mn
|
What is ataxia and what does it look like?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gibf42d"
],
"text": [
"Ataxia is a degenerative disease of the nervous system. People often have symptoms such as stumbling / falling / slurred speech. The incoordination in movement is caused by damage to part of the brain called the cerebellum. I work on a neuro-rehab ward and we see this quite frequently."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krrbdk
|
How did scientists find out how many protons there are in a specific atom.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gibhjbu"
],
"text": [
"The actual process took around a century of work in chemistry, from the 1860s to the 1920s. Chemists already knew that some atoms were heavier than others, and had ordered them into a table using that information. This worked most of the time, because atomic number (the number of protons) and atomic weight (the number of protons plus neutrons, more or less) almost always go up together as you follow the periodic table (which at the time was organized based on chemical properties). But once in a while, it didn't: some elements that were slightly heavier seemed like they should come before, not after, elements that were slightly lighter. So there was reason to suspect that atomic weight wasn't telling the whole story. Physicists knew by this point that the negative and positive charges in an atom could be separated, and that the negative charges covered a wider area than the positive ones. This led to a number of competing models, but the most notable for our purposes was the Bohr model, where electrons (negative charges) were visualized as orbiting a small concentration of protons (positive charges). This turns out to be wrong, by the way, but it was enough to suggest some experiments. In particular, the pull of an electron towards the center of an atom should depend on the positive charges in the center. And it turns out that it does: the energy released as an electron jumps up or down between the energy levels of an atom turns out to be almost exactly proportional to the square of its atomic number, a fact that makes perfect sense in the Bohr model. This suggested that the Bohr model (which could explain this fact) was closer to right than competing models and that the atomic number (which up until that point had just been a position on the periodic table) corresponded to the number of positive charges in the center of a Bohr atom. That is, it corresponded to our modern notion of what \"atomic number\" means. Later on, we learned that the Bohr model doesn't really work (electrons do not \"orbit\" in any meaningful sense - in particular, the first one has no angular momentum whatsoever!), but the tweaks to it that would ultimately make it work in the form of modern atomic orbital theory still preserved the idea of a discrete number of positive charges at the center of an atom."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krrnl9
|
what determines what wavelengths an object reflects to give it its color, and where do these wavelengths come from?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"giblrs0"
],
"text": [
"Electrons exist in discrete orbital levels around the nucleus. Due to atomic mechanics, electrons can *only* orbit at these predefined levels, all at unique distances from the nucleus, and the further out you get, the more energy the electron needs to maintain that orbit. Most atoms [all atoms, in fact, besides helium and hydrogen] have multiple levels that electrons can occupy. When you blast an electron with enough electromagnetic radiation, it will absorb it. That electron now has more energy, and this excitation corresponds to an increase in the orbital level, and it moves upwards. But, because electrons don't really like being in an agitated state, they will try to de-excite and get to lower levels. So, what do they do? To move from a high level to the next lowest level, the surplus energy is converted into a photon and emitted by the atom. An excited electron may have been given enough extra energy when absorbing light to jump up to the 6th level, but to de-excite, it must fall down through all 6 levels. That means a photon will be emitted moving from level 6 to 5, or perhaps from 6 to 4 in one step if it has enough energy for a bigger skip, and then from 4 to 3, and so on. The amount of energy a photon has [its wavelength] depends on the distance between one level and the next. A large distance needs a large drop in energy, so a high-energy photon is emitted, while a short distance only needs to emit a low-energy photon to lose enough energy to fall back down. This is how atoms can emit different wavelengths of light to the ones that they absorb, by de-exciting in different ways that result in different wavelengths being emitted."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krry6o
|
Why are Homo Sapiens the only species of human that exist today? What led to this species evolving, as opposed to becoming extinct like prior human species?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gibk7cf",
"gibju4w",
"gibkwix"
],
"text": [
"War, Disease, and Sex eliminated them. We killed them either through the spread of disease or warfare when encounters, or bred with them breeding them out of existence. One interesting point of evidence for breeding them out of existence is the relics of Denisovan DNA in Tibet and other high mountain natives of that area having blood that is more efficient at moving oxygen thus better at operating in low oxygen environments.",
"One of the current leading theories is that Homo Sapiens alternatively killed or outbred the other human species. We know that there's Neandertal and Denisovan DNA in some parts of the world, that the homo sapiens there interbred with those other human species. But, it is very likely that our ancestors killed our competition, fighting for survival.",
"Homo sapiens are the only member of our genus living today because we adapted to fit many diverse environments, possess cultural exchange (an underrated adaptation IMO), and have a unique capacity to work in groups. Because we benefited from the unique technological and biological adaptations of our ancestors, it may be enticing to think our violent nature is what helped us succeed; however, that is not the case as it would require a complex, 300ka cooperative effort against Neanderthals and denisovans. Evolution favors plasticity over anything else and humans have proven this to be true throughout our evolutionary history."
],
"score": [
10,
5,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krs9la
|
Why does it seem like the last few 1 or 2 percent of a download, update, etc, take forever compared everything before it? Like if it takes 5 minutes for the first 98% the last 2% take 5 minutes alone! Why?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gibw7y4",
"gicj0wh"
],
"text": [
"Imagine that you live in a tropical jungle and that you need a new bed, but the only shop is 2 km/1.2 miles away. Therefore, you send Bob, your friend, to get it. It is very easy to estimate how fast it would take Bob to go to the shop and come back, since you know how far it is, and how fast Bob walks. But, what if Bob met a lion or a buffalo blocking his path? He'd take longer to go and come back, but you wouldn't have a lot of ways of knowing what happened. Downloads work in the same way. Some downloaders estimate the time it'll take to get a file but then slow internet happens (Lion) or there's a lot of people downloading that file at that time (Buffalo) and it slows down the process. Even if the process bar is moving along, if it hasn't adjusted to such changes, then it'll move up until 99%, then stay there as it finishes up the download. Now take the same example of Bob from above. Obviously Bob cannot carry an entire bed with him by himself for that distance easily. But, he can take one leg, bring it back, go back for another, go back for the mattress and so on and so forth until you have all the pieces you need to make a bed. However, you'd still need to put the pieces together to have the complete bed. Same thing with downloads. They don't send the entire file, rather they send little bits and pieces (These are called packets) with instructions on how your computer/phone will put the pieces together. Downloads usually get assembled towards the end of the process, which also makes the last few steps longer than the rest of the process.",
"I've written programs with a progress bar. In the beginning you set the bar to zero and start your long-term activity. You check in to see how it's going and update the bar accordingly. This is really easy if counting from one to a million. Up the bar by 1% at every 10,000, and it'll be smooth through 100. But we don't necessarily know how fast something will download. You check the time so far and the amount of data you've downloaded so far, and you do the math on that to estimate how long it will be until it's done, then do the math again to see how far you need to nudge up the progress bar. Since download speeds often go up and down, this estimation isn't always that accurate. So you get near the end of your bar, 98%, and between your estimation algorithm and the fluctuation of download speeds, you didn't get it quite right. You don't want to make the bar go backwards since that will confuse people (\"How did I just un-download 5% of my file?\"). So your bar sits at 98% until the actual download catches up."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krspi3
|
Why do we look towards things when we hear them?
|
I just heard commotion in the hallway outside my apartment and I instinctively looked towards it. Is that all this is? Instinct telling us to address noises/threats with our eyes? Or do we somehow actually hear/focus better when we are facing it, despite our ears being on the sides?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gibovxy",
"gibootl"
],
"text": [
"Human hearing works by triangulation, with the direction of the noise being very important. Our ears are shaped in such a way as to amplify noise coming from in front of us, so facing a noise will allow us to hear it more clearly. On top of that, actually looking for the noise will help us identify the source of the noise and then verify if that noise is a threat or not.",
"I think that we can’t place the exact direction of a sound unless we face it. I could be wrong though"
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krss9e
|
How/why do electronics work? Like in the simplest terms, a bunch of metals are mashed together. How the heck does that create a computer/smartphone with insane capabilities?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gibpgjz",
"gibzgya"
],
"text": [
"Think of it like water through pipes forced by gravity and water pressure... As it travels through pipes, it can do work. Additionally, it can flip “switches” to change the flow. Using this principal, you can design logic gates and with those you can design adders and perform calculations using only water and pipes. Electrons traveling through circuitry can work the same way. URL_0",
"Digital electronics typically use CMOS logic, where they string together a bunch of [electrically-controlled switches]( URL_0 ) to do math and control other switches. For example, an AND gate (a type of this switch) will output a '1' (or high voltage) if both of the inputs are a 1. The output is then wired to another switch's input that will do something based on whether it's a 1 or a 0. You can string together various types of these switches to do more complicated math and move data around, since the data itself is also 1's and 0's. We've known how to use switches to do math for a long time even before computers were invented, but back then switches were all manual so it was slower than just doing math by hand. It wasn't until we developed faster electrically-controlled switches that computers were fast enough to do anything. Nowadays the switches take trillionths of a second to flip on or off, allowing us to do billions of mathematical operations in a single second."
],
"score": [
4,
3
],
"text_urls": [
[
"https://hackaday.com/2017/01/03/make-logic-gates-out-of-almost-anything/"
],
[
"https://en.wikipedia.org/wiki/Logic_gate"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
krsvan
|
how any average joe can’t become a famous artist by painting something with hidden meaning but “modern art” is considered extremely valuable?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gibqby8"
],
"text": [
"Basically, modern art is based on the idea that since we have photographs now, art isn't just about trying to copy nature. Instead, art is about feelings, making people feel something when they look at it. A painting that may seem simple is designed to get you to think of something, to feel, to look at it and go \"Okay, so why did the artist make this?\" There's a bunch of people who are really into that, and are willing to buy art from artists who are popular and liked by other modern artists and critics. While it may seem simple to go \"I'm going to splatter paint on a canvas and call it art\", part of becoming a popular modern artist is getting others to agree that your art has feelings and emotions behind it, and then to have it displayed at museums so critics and patrons of the arts can look at it and agree. So if Average Joe was willing to participate in the local art scene, and produce works that other artists felt had merit, he could eventually become famous. That being said, the overwhelming majority of modern artists are poor and just make art because they want to. Very very very very few become rich."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krt2dd
|
different waves of feminism. What do they mean?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gibtdpg"
],
"text": [
"*this is a U.S. specific breakdown, though the later waves have similar themes and goals internationally* The waves of feminism were largely based on the problems and social context of the day. Each “wave” is almost like the “next step” in feminism. First wave in the mid-late 19th century and 20th century: the focus was mainly on voting rights for women and was tightly connected to the abolitionist movement. It drove an examination of the woman’s role in society and civil discourse. Second wave of the 1960s-1990s: Now that women had a recognized role in politics, the focus of this wave was sexuality and reproductive rights, which is why you saw the Supreme Court case of Roe v. Wade. The historical context for this wave was characterized by the anti-war movement and the civil rights movement. The first wave of feminism was propelled mainly by middle-class white women, while second wave was driven mainly by POC. The outcome is more higher education for women, more opportunities in business, the birth control pill so women have better control over procreation and abortion rights. Third wave: Started in the mid-90s and focused on reclaiming feminine beauty and language used to put down women as symbols of empowerment. This wave focused on breaking down boundaries in roles of gender, sexuality, class, ethnicity, etc and celebrates these as changing and based on context or situation. The third wave does not have a common list of grievances, but rather focuses on equal rights. Struggles are more individual. We’re currently in what is considered the “fourth wave” and is still being defined. It’s mainly characterized by the fact that formerly “extreme” views are more common and no longer considered extreme- this includes a rejection of transphobia and homophobia, societal abuse of women, unfair pay, and better parental benefits for both men and women. This wave of feminism focuses on the fact that it is not only to benefit women, but to benefit society as a whole. A lot of this analysis was drawn from an article, *Four Waves of Feminism* by Martha Rampton from Pacific University Oregon."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krty68
|
If blood pressure is usually between the 120 an 80 mmHg, and air pressure is around the 760 mmHg, shouldn't the air rush into your body when you have a wound? Instead of the blood rushing out.
|
As the title says: If the blood pressure is lower than the air pressure, shouldn't the air go into your body when you have a wound but does the blood come out?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gibwplp",
"gibxl7j",
"gibwy4j"
],
"text": [
"These measurements are taken with different references. When you are measuring pressure you usually measure the difference in pressure between two volumes. It is very common to use atmospheric pressure as one of the volumes to measure against. This is what you do when measuring blood pressure. This makes it easier to measure but is also more universal as your absolute blood pressure does vary with atmospheric pressure. When you measure atmospheric pressure though you obviously can not measure it against itself as you would always get zero. So we usually measure it against perfect vacuum to get a repeatable consistent measurement. This gives you an absolute pressure as it is not relative to anything else. So technically your blood pressure is between 880 mmHg and 840 mmHg absolute pressure. However if you are on a mountaintop or under water this will change so these numbers do not make much sense to use.",
"I have worked as an engineer for decades in areas that are very specific to relative pressure. I read your question and thought, \"FINALLY A QUESTION ON A TOPIC I HAVE UNIQUE EXPERTISE IN!!!!\" But then you guys did a great job first. Thanks for crushing my dreams.",
"Atmospheric pressure is 760 mmHg on the absolute scale, while blood pressure is measured using gauge pressure. The simplest way to explain the difference between the two is that absolute pressure uses absolute zero as its zero point, while gauge pressure uses atmospheric pressure as its zero point. Due to varying atmospheric pressure, gauge pressure measurement is not precise, while absolute pressure is always definite. Edit: So your blood pressure measurement on the absolute scale = 760+120 mmHg systolic, 760+80mmHg diastolic"
],
"score": [
10,
8,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krup8e
|
What are JPEG artifacts and why do they happen?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gic0uf2"
],
"text": [
"Compression finds patterns in data and and tries to represent them in as little space as possible. JPEG is also a lossy compression algorithm which allows for data loss. What happens then is that the image is broken into blocks and if colors are similar enough, they are represented as a single color. When the image is rendered, these can appear as blocky sections usually apparent near gradients or line art, such as text. The higher the level of compression of a lossy algorithm, the more data loss, and the more pronounced the effect."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
kruxf3
|
How does Verizon afford to give customers this deal?
|
Exploring phone plans with my fiancee right now, and we're both sticking with Verizon from our parents' plans. There's Disney+, Hulu, ESPN+, Discovery+, Apple Music, and Cloud Storage; all perks adding up to $35. Which leaves $45 for Verizon to make money(?). What are the remaining margins after expenses? Are they just eating the costs to incentivize new phone plans? I don't have the most robust background in economics, especially business, but I am always curious how small some profit margins can be for some industries. Edit: wow! All these answers were so quick and thorough. I had a feeling I was going to hear some of the things here, but for brevity's sake I kept my post short. Also I learned stuff I didn't know before!
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gic250w",
"gic265o",
"gic26cb"
],
"text": [
"Large corporations don't pay the same prices for products that we do as consumers. This promotion is as much a marketing deal for Disney and its subsidiaries as it is for Verizon. I don't know the exact scale of discount that Verizon is getting, but i would expect it to be substantial.",
"They are likely not paying the same price for those services that you are. They’ve cut some deal with Disney and Apple to offer those services with their phone plans and are getting some kind of bulk discount.",
"Verizon doesn’t pay retail for those services they’re offering... they negotiate a much lower rate. The streaming platforms are willing to take less from more people, as marginal costs to offer service to more people is very low. And loss of access (or having to start paying separately) reduces customer churn for Verizon, who this can spend less marketing dollars to replace lost customers."
],
"score": [
7,
4,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krv4l3
|
What is the biological reason for why too much brightness is destructive to eyes?
|
Wouldnt it be better for eyes to not be destroyed if they look at the sun. They could have anything too bright cap out at a certain peak brightness without harm. Why is brightness so powerful.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gic48zs"
],
"text": [
"Evolution doesn't work like that. Our visual system affords us excellent spatial tracking, binocular vision, color perception in the visual wavelength, and the ability to focus on and track both near and distant objects- not to look at the sun. There isn't an evolutionary advantage to be able to stare at the sun without harm, so that trait would have never developed. The light sensitive tissues of our eyes simply did not develop the ability to absorb that much radiation without being damaged."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krv7gl
|
How come a lot of times the conventional flow of electricity is still used when describing how a device works even though we know electrons flow the opposite way?
|
I've been watching a lot of electric circuits related videos lately and on probably 90% of them, they always talk that the current is flowing one way, but that we shouldn't confuse it the real flow of electricity. Is this just a convention or is there an underlying reason for it?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gic57zk",
"gic7wtj"
],
"text": [
"It's a sign convention. As long as everyone adheres to it, the math works. Changing sign conventions tends to lead to chaos, in my field, that happened with the convention for the magnetic field. You have to double check each text now to find out how they define it.",
"There's no reason to. The reasoning is that, mathematically, there is no difference between positive charges flowing one way and negative charges flowing the other. This is why we mislabeled them in the first place."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krvfqj
|
Why does it seem like people cannot stand still when waiting? (e.g. gently kicking a wall while waiting, doing things with their arms, etc.)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gicblds"
],
"text": [
"We are used to doing tasks and getting rewards, results. Even when laying still watching the telly, we're focused on something and getting pleasure. When we're idle, a primitive part of the brain wants to continue being rewarded or focused on a task that could yield a reward."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krvixn
|
Why do humans get concussions so easily?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gic5vt6"
],
"text": [
"Many animals get concussions... your brain is in a fluid inside your skull. If your skull gets knocked hard enough that your brain hits the side of your skull then you’ll get damage. The woodpecker actually has its tongue wrap around its brain to protect it while pecking holes."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krvr8p
|
Why do all of the videos of deep water animals seem like they’re moving in slow motion?
|
Especially when the animals in shallower water don’t seem to do this?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gic8a8g"
],
"text": [
"Not a lot of water turnover in deep oceans. Also no photosynthesizing plants. This means oxygen levels are lower. To accommodate, animals in lower oxygen environments conserve energy. They move slower as a result"
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
krvs8w
|
How do mountian top plants get pollinated?
|
Since there are low levels of gases, and has extremely cold with long winters and short summers, not many insects and things want to go up there. So what pollinators pollinates plants on top of cold mountains? How? I need an answer cause man, my teacher isn't too good at explaining
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gic8cvw",
"gic9d7s"
],
"text": [
"Wind? Growth is sparse for a number of reasons, no?",
"Oh there are definitely pollinators up there. These plants have adapted to using a niche pollinator, the pollinator has also adapted to living in a niche environment. Although there is less air, there is also less competition for resources for both the plants and insects. You can see the benefits of colonizing an environment that isn't popular to survival. You'll find that these plants bloom around the same time their pollinators are around, usually around summer or spring when temperatures are a little less frigid. But I'm talking flowers here. In the case of grasses, most of these have derived wind pollination from insect pollination."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krvuzc
|
If mayonnaise is made with raw eggs, how come we do not develop sicknesses or side effects related to this upon consumption?
|
I have just learnt that mayonnaise is made with raw eggs, but how come we do not experience any illnesses as a result?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gic7u0r",
"gic8prf",
"gicfwjn"
],
"text": [
"Commercially made mayo is pasteurized, basically heated for an extended period to sterilize it.",
"Also, people used to get sick sometimes from mayonnaise or mayonnaise-based recipes being left out (think potato or macaroni salads). But most mayonnaises now have such a high acidic content (vinegar) that its not a big problem anymore.",
"Commercial mayo is pasteurized. Homemade mayo could conceivably give you salmonella, but the risk of that is low, even in the US. You run the same risk if you sneak some cookie dough or eat a runny egg. Either kind of mayo should be refrigerated - homemade immediately and commercial after opening."
],
"score": [
22,
5,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
krwb8z
|
Airline Milage Programs (specially with regards to alliances). How do people actually save money with these?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gicb2hd"
],
"text": [
"It's basically like cashback on a credit card - only instead of getting say, 1% back on any purchase, you're getting airline \"points\" which have a variable cash value for flights on that specific airline. So if you fly with a specific carrier a lot, it may be more advantageous monetarily for you to have that versus cash back, as OFTEN BUT NOT ALWAYS the amount of value you get back through the airline is more than a general cash back offer."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krx6u9
|
Why is water so essential for Life?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gichlkc"
],
"text": [
"For many chemical reactions, your reactants need to mix. They need to be mixed so well that every molecule reacts with every other molecule. Sure, you could grind it into a powder and mix it for a long time, or melt it and mix it, but if you add just a bit of water then they can dissolve and mix without *any* other work on your part. Thus, water facilitates almost all bodily chemistry."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
krylo1
|
Where is headache pain actually happening if not brain?
|
I understand that our brains don't have nerves of their own, so where is headache pain actually coming from? I suffer from migraines that are sometimes on one side of my head, sometimes behind one eye, or just everywhere at once, and I've always wondered where the actual pain is coming from. Hope this makes sense.. lol
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gicsos1"
],
"text": [
"Most headaches start in the nerves of the muscles and blood vessels that surround your head, neck, and face. These pain sensing nerves can be set off by stress, muscle tension and other triggers. Once activated, the nerves send messages to the brain, and it can feel like the pain is coming from within your head even tough its not... To get rid of the migrane I would try to find out what triggers them (e.g lack of sleep, ...) and avoid those."
],
"score": [
15
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
ks07rg
|
If low interest rates stimulate the economy what are the advantages of raising them? What are the disadvantages of keeping them low permanently?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gid2yh9"
],
"text": [
"If interest rates stay low, that will encourage people to borrow money because they can borrow it at low interest rates. That stimulates the economy because it encourages economic development, but there are at least two risks that I know of: 1) If interest rates stay low, then that means that there’s a lot of money flowing through the economy, which causes prices for goods and services to rise (a process also known as inflation). If that goes on unchecked, then you could see prices rise so much that you enter a period of hyperinflation, where the price of goods and services rapidly rises beyond what most people can afford. Rates usually rise to collect that extra money in the form of higher interest rates to temper inflation and prevent hyperinflation. 2) If enough people who aren’t financially responsible borrow money when interest rates are low, but then can’t afford to make regular payments on their debt when interest rates rise, then they could default on their loans and the lender (say either a bank or the government) has to take the loss. If that happens across enough individuals and businesses borrow more now than they can afford later, it forms a bubble that bursts when they later default on their loans and that could overwhelm the lender, which again could very well be the federal government. In turn, the lender can either go out of business, or the government can bail out the lender or itself with taxpayer dollars, which could’ve gone to more worthwhile causes."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ks08e6
|
How come we never see pictures from space as if the photographer was looking up at the earth?
|
I’m not a flat earther. Do satellites and the ISS ever fly under or over the earth?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gid2b2l",
"gid1ua2"
],
"text": [
"There is no over or under. The earth is a ball in space. The idea of north being up is something map makers and globe makers did centuries ago. It's what we are used to seeing, so pictures are taken that way, or the image is rotated to appear that way. There are images taken at the poles, but it doesn't look like your looking up or down, but straight at that section of earth.",
"There is no bottom. The Earth is a ball. Most orbits follow the equator. You can find pictures of Earth from any angle, but most come from the equator because that's where the ISS is."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
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