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lou3yp
|
How do modern websites display real time database results as you are typing?
|
Technology
|
explainlikeimfive
|
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"text": [
"The webpage listens to every key you type in the search box and send a request each time. You can see it for yourself - go to Google, press F12 or Ctrl+Shift+I to open developer tools and open the Network tab. You'll see that with every key you type, a new request is sent. > Doesn't this cause a big strain on their system? Sure, far more than without it. But they have big servers farms with lots of servers that can handle this volume of data. > Is this a new technology? Not that new. Google introduced it in 2010. It existed in offline applications long before that.",
"Based on the type of database, the search (called \"query\") can be pretty fast. So I would assume that those websites are just updating the query everytime there is a change in the search box. You should be able to notice that by the fact that the results does not update in real time when you type really fast.",
"The other answers aren't wrong, but there's another layer to it: caching. When someone types something in the search box, the website looks through it's database and returns the results. *And* it saves the results. Now when someone else comes and types the same thing, the website doesn't have to go through the database. It just grabs the results from before. But eventually the saved results are too old and out of date or no one types the exact same thing for awhile. So the saved results are thrown out. This temporary saving is called caching, and basically every website uses it to prevent overloading the servers."
],
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9,
4,
3
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[
"url"
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[
"url"
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|
louh92
|
How does the QR code manages to not be the same with other QR code that has already been generated?
|
I was reading online and saw an option when I right clicked an image to create a QR Code. I know QR Codes are unique but how do they manage to avoid having the same pattern with the other QR Codes? Does it have a database where all QR codes are stored? I tried searching through this but can't find any similar queries aside from QR codes are unique.
|
Technology
|
explainlikeimfive
|
{
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"text": [
"If you generate two QR codes for the same piece of text or link, you'll get two identical QR codes. They're not randomised or generated out of thin air and then matched with a site or link or something. Rather the QR code itself encodes the information onto it. So as long as whatever you're encoding is unique, the QR code is unique to it. The wikipedia page (section 'encoding') actually shows you how it functions.",
"> I was reading online and saw an option when I right clicked an image to create a QR Code. I know QR Codes are unique but how do they manage to avoid having the same pattern with the other QR Codes? Does it have a database where all QR codes are stored? I tried searching through this but can't find any similar queries aside from QR codes are unique. A QR code is only unique in the sense that the word \"house\" is unique. It's simply a different writing system - there is no database.",
"QR code is just a way to encode text as a series of black and white dots. The QR code isn't for the image itself, it's for the image's URL.",
"a QR code isn't just a random image that then gets associated with a link or some text. It's like a secret code. There's a key that translates a letter to a specific pattern of pixels in a specific location in the square. When you scan the code, you use the key in the reverse to translate it back into text. A barcode is basically a simpler version of a QR code. For each digit 0-9, there's a specific pattern of black and white stripes. Smash a bunch of them together and you get a barcode that can be translated into a number."
],
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35,
14,
11,
5
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|
[
"url"
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[
"url"
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louhuj
|
What is NFTs and DeFi?
|
Technology
|
explainlikeimfive
|
{
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"go7sd9h",
"go7sol9"
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"text": [
"DeFi means decentralized finance, which means that there isn't one entity controlling the finance operation. The centralized model is that there is a bank or something similar and when you want to do something with money, like exchange it to another currency, you need to go to the bank and they exchange it for you. The idea of DeFi is to cut out the bank. Instead you have a secure way to either exchange the money with someone else directly or with a blockchain. This is different inthat way, that the blockchain can't influence the exchange outside of the known rules, because it is basically just a simple program. Your account can't get frozen, you can't get rejected, you are anonymous and all of that while still being secure.",
"Fungible means something is interchangeable. Bitcoin for example, in the crypto world. 1 Bitcoin = 1 Bitcoin, it doesn't matter \"which\" bitcoin you own out of the millions in circulation it is identical in property and value to any other Bitcoin. Non-fungible is simply the opposite. Each token is unique and it can't be replaced by another token. DeFi means Decentralised Finance. Its a general term used to describe financial systems which don't require something like a traditional bank and instead run on a smart contract blockchain. Ethereum is the biggest example."
],
"score": [
5,
3
],
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|
[
"url"
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[
"url"
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|
lout3j
|
Quadratic payments
|
I won't lie I read Vitalik Buterin article about Quadratic Payments ([Here]( URL_0 )) but really didn't get how it works and what could be applications of it.
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"go7w2kt"
],
"text": [
"Application: primary election with multiple candidates. Eligible voters can vote for or against as many of the candidates as they wish. They can cast multiple ballots for or against the same candidate. Every voter starts with be hundred points. If they want to cast one ballot for a candidate, it costs one point. If they want to cast two ballots for a candidate, it costs four points. If they want to cast three ballots for a candidate, it costs nine points. If they want to cast ten ballots for a candidate, it costs a hundred points. They can cast ballots against a candidate, and negative ballots cost points the same way: ten negative ballots for a single candidate cost one hundred points. Suppose a voter likes candidate K best, thinks P, C, and B would be better than average, and thinks T is a crook that must be stopped. That voter could use sixteen points to cast four ballots for K; three points to cast one ballot each for P, C, and B; and eighty-one points to cast nine negative ballots against T."
],
"score": [
6
],
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[
"url"
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[
"url"
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lov1xg
|
Why are teeth such a big deal for humans ?
|
Biology
|
explainlikeimfive
|
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"text": [
"Teeth deterioration came with the rise of sugar contents. Back when this wasn't a thing our teeth had a lot less trouble keeping themselves healthy. We also live a lot longer now so out teeth have to stay in good condition for a much longer time",
"Things that keep me up at night: Why isnt it called a teeth brush?",
"Whitetail deer have a life expectancy of less than 10 years. A leading cause of death in older deer is starvation due to being unable to chew because of tooth decay.",
"Animals definitely do have mouth and teeth issues. On discovery a couple days ago, a old zebra had a few of their main teeth starting to deteriorate she was on pain killers and there was no quality of life. They had to put the Zebra down :( It actually gets worse for animals cause they can’t brush every day.",
"on your note about braces or headgear to straighten teeth, its been found that diet has a profound impact on teeth alignment . harder foods requiring more chewing is better than soft foods. also, where a person holds their tongue makes a difference as well. these sorts of things can be taken advantage of before the facial structures solidify permanently. Parents who want to avoid the cost of braces and other orthodontia can go to specialists that will work with children and teens to help prevebt entirely or at least reduce the amount of work that braces or headgear must do.",
"The bit about needing to brush your teeth regularly is very likely a myth. Prisoners of war etc went for years without brushing their teeth or any oral hygiene whatsoever and didn't lose all their teeth. My dad never visited a dentist for about 30 years and never had tooth problems, and I haven't been to the dentist now for about 20 years (and that was due to an abscess caused by wisdom teeth coming through) which suggests that I've inherited my dad's healthy teeth. Modern eating habits has taken away our need for healthy teeth so evolutionary wise our teeth are in a bad way, which causes us to need more dentistry etc. Animals in the wild would never outlive their teeth as they are essential for survival. That isn't the case for humans. The obsession for perfect teeth is about aesthetics in the modern world. Perfect looking teeth means good genes which in turn makes us a more attractive mating prospect."
],
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7,
3,
3,
3,
3
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[
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[
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|
lov630
|
Why do humans move their heads, legs etc. to the rhythm of music?
|
Biology
|
explainlikeimfive
|
{
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"go7ulsm",
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"text": [
"It's easier to keep the beat and rhythm when you physically move. When you don't it's very easy to lose the beat.",
"ELI5 answer: Humans evolved with music. Ancient tribes/packs of humans used music for many reasons, such as for celebrating or for bonding. Humans evolved to be very social. Singing and dancing was a common way to socialize, which strengthened unity in the tribes. Our love for moving to the beat and listening to music comes from that evolutionary history of our ancestors using music in their lives."
],
"score": [
3,
3
],
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[
"url"
] |
[
"url"
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|
lovah8
|
If cis-platinum (chemo) is "probably carcinogenic" according to CIRC, how can it also be an effective cancer treatment?
|
Biology
|
explainlikeimfive
|
{
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],
"text": [
"Those carcinogenic effects were observed in [lab rats]( URL_0 ). Further research is needed. At the moment, the CDC advises that the benefits outweigh the risks. That’s why... probably.",
"you can use a sword to cut block another sword and still hurt yourself with it, right? Cis-platinum is basically a poison killing tumors, but the way it kills them could also hurt normal cells in a way, that they become tumors themselves. So while fighting the tumor it is possibly creating new ones, being treatment and carcinogenic at the same time.",
"Cis-platinum works by destroying your DNA and making it unable to replicate. Of course it doesn't destroy all of your DNA at the same time as soon as you take it. It destroys the DNA of the fastest growing cells first. Because cancer cells generally grow faster than healthy cells this can be used to kill the cancer without having too much trouble with the rest of your body cells. You still do some damage to your healthy DNA which could potentially cause cancer, but it's still better than doing nothing and letting the original cancer grow. The same thing goes for radiotherapy. You shoot radiation through the cancer cells (and to the surrounding area) and this radiation can potentially cause cancer. This is one of the reason why some patients develop cancer again, years after they defeated it initially. But a 2% higher chance of developing cancer again in 4 years is generally better than a 100% chance of having cancer now and not doing anything :)"
],
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9,
8,
5
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"text_urls": [
[
"http://www.bccancer.bc.ca/drug-database-site/Drug%20Index/Cisplatin_monograph.pdf"
],
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[]
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}
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[
"url"
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[
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|
lovmvc
|
How can magnesium deficiency cause anxiety and high Blood pressure? Isn't anxiety psychological?
|
Biology
|
explainlikeimfive
|
{
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"text": [
"Magnesium, potassium, and sodium are all electrolytes, which are required for nerves to fire correctly, from our brain to our toes. What you feel as “anxiety” are a series of symptoms produced from neurotransmitters that are out of balance. More cortisol and/or norepinephrine, less GABA and/or serotonin. I’m not sure how well understood it is but magnesium seems to have an effect on the hypothalamic-pituitary-adrenocortical (HPA) axis, which is a fancy way of saying where the body’s stress responses are controlled. The body’s stress response is controlled through the release of neurotransmitters. If our body is reacting like we are about to die in a tiger attack, but we are sitting in our living room, that is anxiety. Edit to add: high blood pressure probably has more to do with a sodium/magnesium imbalance",
"Psychological is still physical. That's your mistaken assumption. It's chemistry all the way down",
"Everything is chemical. That's why medication works at all... our brains need the right chemical mix to work. Too much or too little of a critical chemical can screw up the balance.",
"I can answer the high blood pressure part of the question. Our blood vessels are surrounded by smooth muscle (which is distinct from skeletal muscle). Smooth muscle relaxes in the presence of magnesium. If magnesium levels are low, it creates an irritability or hypertonicity in the smooth muscle surrounding our blood vessels. As a result, the smooth muscle contracts and the blood vessels become constricted. And, just as narrower diameter in a garden hose creates higher pressure, the constricted smooth muscle around the blood vessels results in high blood pressure.",
"> Isn't anxiety psychological? What is \"psychological\"? Everything in your body is chemicals. Your thoughts are neurons firing, which they do by moving ions and other chemicals around. Your actions are nerves moving sodium and potassium and causing muscle fibers to contract. Happiness is a specific chemical binding to various receptors. Sadness is different chemicals and different receptors. Love is hormones and neurotransmitters. There is nothing \"psychological\" that you can't affect by raising and lowering the physical presence of different atoms and molecules in different locations."
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[
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lovphv
|
How can bands play cover versions of older songs & make money doing it, without penalty? Do they have to pay licensing beforehand?
|
Other
|
explainlikeimfive
|
{
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"text": [
"A mechanical license is all that's usually required (in the USA). You can cover any song you want for $0.091 per copy that you sell, paid directly to the owner of the song (whoever legally owns the rights to the song, almost always the publisher). The person who owns the rights doesn't have any say in the matter. You usually have to pay this fee upfront based on an estimate of how much you'll sell. If you think you'll sell a thousand copies, you'll pay $91 upfront. If you're streaming on YouTube or Twitch or whatever, you'll need a synchronization license instead. For a synch license, you need permission upfront and they can charge whatever they want to charge for it. For live covers, if you aren't recording the event it should be fine, but if you're playing a really big gig/recording it for sale you'll need to get in touch with either ASCAP, BMI, or SESAC to obtain public performance rights and pay public performance royalties. & #x200B; Finally, there is the strange case of music copyright that allows you to play any unpublished song you want without issue. An unpublished song is one that hasn't been recorded and released for sale. For example, the Mountain Goats had an album called Hail and Farewell, Gothenburg that was never released (until it leaked), but they'd occasionally play songs from the album live. Because it was never released for sale, anyone could cover those songs absolutely free, because they didn't have legal rights. Only published songs have legal protection.",
"Do you mean cover bands playing live in a bar? Or an original band putting someone else's song on an album?"
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3
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[
"url"
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[
"url"
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|
lowulb
|
when it comes to cooking meat, and maybe pies, why do we have to let it "rest" once it's fully cooked?
|
Chemistry
|
explainlikeimfive
|
{
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"text": [
"To keep the juices from flowing out once you cut into it. Allowing it to “rest”, retains the juices so you have more flavourful meat. From your friendly neighborhood vegetarian.",
"For meat: During cooking, some of the liquid (mainly water) in the meat is set free. If you'd cut it immediately after, that will flow out. Leaving it rest leads to part of the liquid being reabsorbed by the meat, leading to a better texture and not so much \"juice\" flowing out. For pies that need to rest: Letting them rest allows the whole thing to take a more stable form (not as soft) - I believe this is a natural continuation of the ingredients bonding with each other during the baking proces. Again, it improves the texture (won't \"fall together\" easily, for example).",
"Because it isn't fully cooked. If you heat it up until the internal temperature is ~150°F and then remove it from the source of heat (the stove or oven or grill), the internal temperature is *still* ~150°F until it has time to cool off. That residual heat will continue to cook the meat as it cools off. Cooking times are made to account for this, so that you remove it from the source of the heat early: if you leave it on heat until the inside is actually fully cooked, once you take it off heat it will continue to cook and end up overdone. It depends on when and how you intend to serve the dish, though. For example, if you're grilling and you will serve the meat immediately from the grill to the plate buffet style, you will serve the meat \"hot\" and you don't need to let it rest. Your diners aren't waiting for the meat to be served and everyone to sit down to eat together. The meat won't have a chance to keep cooking anyway because they'll be digging in as soon as they get it."
],
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5,
3
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[
"url"
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[
"url"
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|
loxj0n
|
What is the difference between virtualization and grid computing
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"go8cofm"
],
"text": [
"That's kind of a strange question since they don't really have anything to do with each other. Virtualization is basically simulating a computer on another. Grid computing is using a bunch of computers to compute something big."
],
"score": [
3
],
"text_urls": [
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[
"url"
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[
"url"
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|
loycuz
|
Why do we need really big and small speakers to properly reproduce 20hz-20khz at high volumes, but headphones can do it just fine?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"The larger the speaker, the harder it is to yank it back and forth 20 thousand times each second. But it can move more air than a small one, too.",
"Two points. 1) just fine isn't enough for some people ( audiophiles). 2) to make speakers louder, they need more power, the more power you need, the better quality components you need, which are generally heavier. Trying to move a 5 lbs speaker cone 20000 times a second just won't work. So they divide the work between multiple speaker elements.low frequency to the big cones, and high frequency to the smaller tweeters",
"Headphones aren’t high volume. Speakers generally have a hard time vibrating slowly for lows and quickly for highs at the same time, so by separating them you make both speakers sound better than the original.",
"It's all about the size of the space you want to fill with sound. If you want to fill a small space, say the inside of a headphone muff, then it takes a small amount of sound. Want to fill the tiny space between an earbud and the eardrum, even a super tiny speaker can do the job. Alas, many rooms are much larger, large enough to walk around in. That takes much, much more sound energy. You could do this with many, many tiny speakers. It would be good because tiny speakers can move very quickly and reproduce a broad spectrum of sound efficiently. Alas, an array of 1M earbud speakers would cost far too much money. Instead large rooms use fewer speakers and sophisticated audio equipment that measures the room's acoustic properties and applies large amounts of power to a few larger speakers to make the right sound profile. When it comes to higher frequencies, smaller speakers can be more efficient, so the overall speakers mechanism can be made be made a little smaller by a mix of large speakers for low frequencies, medium sized speakers for middle frequencies and small speakers for high frequencies.",
"Bigger speakers are louder but are harder to move fast enough to produce high frequencies, which is why bookshelf speakers tend to separate out the frequencies using different sizes of speakers. In headphones the speaker diaphragm doesn't need to move all that much since they are pretty quiet relatively speaking. This means that the smaller diaphragm can be used to produce more frequencies since it doesn't move all that much anyways"
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16,
11,
5,
5,
3
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[
"url"
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[
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|
loyhta
|
why foods like boiled rice, pasta or deep fried fries rise up to the surface when done cooking?
|
Chemistry
|
explainlikeimfive
|
{
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"text": [
"I think, it is because as they absorb water their mass becomes less than the boiling water. Hot water is less dense than cold water, so as the water cools those things then sink back to the bottom. For the fries ... Deep frying is actually considered a \"dry cooking\" method. In deep frying though ot is actually a LOSS of moisture in the food (fries, chicken, veggies) that causes it to float to the top. Same thing happens when the oil cools, those items would sink. ELI5: The food becomes \"lighter\" when cooked and hot. Heavier when cold or raw. Hot liquids push these lighter foods to the top.",
"The wayer in the food heats up and makes steam and leaves the food. Thats partly why it gets crispy. It aalso soaks up some if the oil. Think of mixing oil and water: the oil floats to the top and water at the bottom. Food with high water content is heavier and sinks and when theres less, it floats."
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4,
3
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[
"url"
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[
"url"
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|
loyveh
|
Why do text banners with blue lights look blurry from some distance ?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"go8eeyq"
],
"text": [
"Your eye has 3 different color-sensing cells (photoreceptors) that have maximum sensitivity at red, green, and blue. However, they are not evenly distributed. You have more red and green photoreceptors than blue so you see sharper in red and green, especially in the very center of your vision. In addition the eye acts as a lens to focus light down to a spot. It's generally tuned to focus red and green light to a tighter spot than blue light."
],
"score": [
7
],
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|
[
"url"
] |
[
"url"
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|
lp02tp
|
Why does a tube of lip balm in a pocket only ever screw upwards?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"go8jhnq"
],
"text": [
"I think what you're experiencing is confirmation bias. When it screws down it doesn't affect anything. You don't notice it. When it screws upwards it gets in the cap and makes a mess, you notice it then."
],
"score": [
11
],
"text_urls": [
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[
"url"
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[
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|
lp0acw
|
- why eating a lot of painkillers is bad for your health?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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"go8ku6f",
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"go8l4wt"
],
"text": [
"Here's a true ELI5 answer without going too far into the science behind it: It depends on the type of painkillers. Narcotic painkillers can cause an overdose if taken in too high doses. Other over the counter painkillers (especially acetaminophen aka Tylenol) can cause damage to the liver if you take too much. When the medication is processed it creates a compound that can accumulate in the liver and cause issues (in high doses of course).",
"What painkillers are you talking about? Tylenol is the #1 cause of acute liver failure in developed countries. NSAIDs like ibuprofen, naproxen, and meloxicam are very harmful to the GI tract over long periods of time and can cause peptic ulcers among other things. Opioid painkillers cause constipation and physical/psychological dependence. All painkillers can ironically cause more pain over long periods of time due to things like medication overuse headaches and opioid-induced hyperalgesia, so they can cause thing they're supposed to be treating.",
"Because you can overdose on opiate painkillers which will stop your breathing and heart. Many also contain tylenol which are toxic to your liver in large doses or when used chronicly.",
"If you are using a NSAID type of painkiller such as ibuprofen you can get stomach ulcers and bleeding especially if you are on a blood thinner. Also they are bad for kidney health by decreasing the blood flow to them."
],
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13,
10,
6,
3
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[
"url"
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[
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|
lp0eeo
|
Why isn't biopesticide populair yet?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go8m24a"
],
"text": [
"They're often less effective and less reliable/predictable, they're more prone to resistence developing, but most of all, there is big concern for unintended consequences. The use of biological pest control puts living organisms into the environment that may end up doing things other than what we want them to. They may get outside of the intended area and become an issue to wild species we don't want to be effected or adapt in unforseen ways to pose a hazard to the natural biome. Biological pesticides can change and react where poisons are just poison. They can have some unintended consequences as we've seen in the past, but those hazards are static and unchanging and that makes them easier to predict and control when it happens."
],
"score": [
14
],
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[]
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|
[
"url"
] |
[
"url"
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|
lp1k8i
|
What happens once curiosity or Perseverance die out?
|
Like do they just stay in Mars? Do they self destruct? What about voyager 1 or 2
|
Technology
|
explainlikeimfive
|
{
"a_id": [
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"go8rcbv"
],
"text": [
"> Like do they just stay in Mars? They don’t really have any other options do they? When they stop working they aren’t going to suddenly decide to teleport to Earth or something. Their behavior will become the same as other inanimate objects. > Do they self destruct? There was no reason to include a system to turn a rover into small pieces of rover spread all over the place, and several good reasons not to. A self-destruct doesn’t make something just vanish. > What about voyager 1 or 2 They too will do what inanimate objects do, namely nothing. The Voyager probes will keep on going until they hit something.",
"They get left there. We generally continue to listen for them in case they turn back on somehow. We might go looking for them once we get humans on Mars."
],
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8
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[]
]
}
|
[
"url"
] |
[
"url"
] |
lp1nmk
|
How do the kidneys and liver work together exactly?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go8uo2s"
],
"text": [
"Liver works in breaking down proteins entered by food into either carbohydrates or fats (depending on your body state), and the wasteful byproducts such as ammonia are then turned into urea and released into the bloodstream, which is then filtered through the kidney and into the bladder. It should also be noted any wasteful product inside the bloodstream is also being filtered in the liver, ethanol is one of them."
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp1zxl
|
Why does touching certain electronics cause a hum in bluetooth headphones?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"go95x45"
],
"text": [
"A deep low pitch hum sounds like a ground loop. That’s when two components are supposed to share a common ground, but due to some problem, there is an electrical potential difference between the two grounds. (Sorry, but electrical theory really can’t be explained at a “Like I’m Five” level) when you touch the power supply, you are grounded to the same circuits as the computer thus eliminating the ground loop."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp29bp
|
why did the battle flags of Northern Virginia and Tennessee become known as the confederate flag?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"go8xu9j",
"go906y2"
],
"text": [
"The is not a single national flag for the Confederate States of America. There are three. The first one \"Stars and Bars\" 1861-63 do not look like the battle flab but the one adopted in 1863 (\"The Stainless Banner\") and 1865 (\"The Blood-Stained Banner\") contain the battle flag. 1863 is the battle flag upper left corner and the rest of the flag is white [ URL_1 ]( URL_0 ) The first national flag has a problem in that it looks like the US flag so the was easy to confuse in combat. So the battle flag was used and become popular and later adopted as the national flag. The distinctive look is a reason it was used later by people but often stretch to a rectangle like most other flags. The battle flag was a square, variant used today is closed to The Second Confederate Navy Jack. I would also say that the battle flag looks better than the \"Stars and Bars\" as a flag. That is if you discredit the symbology of it.",
"It's a striking, pretty, distinctive design. If you're going to adopt a symbol, you don't want to adopt one that's forgettable or not distinctive or not aesthetically pleasing."
],
"score": [
18,
11
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Flags_of_the_Confederate_States_of_America",
"https://en.wikipedia.org/wiki/Flags\\_of\\_the\\_Confederate\\_States\\_of\\_America"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp2i23
|
What happens to new cars, if they are not sold?
|
I wonder what happens when the new model of a car arrives and they still have full stocks of an older model. Do they just get rid of the "old new cars" to keep the price of the new model up? Are the old ones recycled or left somewhere as a garbage? Is their fate similar to other products? Thank you for the answers.
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"go8x8lu",
"go8wwq2",
"go8x9cy"
],
"text": [
"Usually dealers will offer more incentives to try and move old stock. Usually will combine offers from the manufacture. Like cash back with a low APR. if the stock still doesn’t move, let’s say for example it’s getting closer to what they paid for a car, they will sometimes send unsold units to the action to recover some losses. It’s happens but it’s not super common. A good dealer knows more or less how many units it will sell any given month, what cars are more popular than others ect. Edit: same kinda thing happens with motorcycles too, but depends on how big the dealer is. Some smaller dealers can’t take a loss, so you will occasionally see motorcycles a few years old for MSRP with zero miles. But again some bikes will then go to an auction to be scooped up and sold as “used”.",
"New cars which are not sold will gradually become older cars automatically. Eventually someone will buy them, there is no need to recycle or destroy them.",
"Some are turned into loaner cars, some are sold to customers that want \"better price\" than newer stocks, and the rest are sold via auction. Closer to none are destroyed."
],
"score": [
18,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lp386w
|
How does echolocation work in groups?
|
How do bats not get confused by the sounds other bats make when they’re all together in a group each trying use echolocation? Wouldn’t every bat hear the sounds made by all their bat friends rendering the information useless? (Sorry if the flair isn’t accurate I tried my best)
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go997f2",
"go9d2ap",
"go9cbjw",
"go9o6st",
"goaozz6"
],
"text": [
"Due to the [Huygens-Frensel-Principle]( URL_0 ) (which I think is ELI5) the echo sounds just like a sound source shaped like a point, no matter which bat the signal came from. Additionally, bat echolocation just works maybe for a few meters. Beyond that, the echo is too soft for even bats to hear.",
"I know how we handle this with radar. We use different center frequencies and different waveforms. You can design two waveforms that are not correlated with either other very much.",
"If all your friends are out at night and you all have flashlights, does that make the light useless?",
"It's the same concept as being somewhere like a crowded stadium. There could be 50,000 talking/yelling fans, many of whom are right near you. And yet you don't have a huge problem chatting with your friend in the seat next to you. I can hear my voice and my friends voice, despite other voices being around.",
"Here's a podcast about it: [The Curious Cases of Rutherford & Fry: The Baffled Bat]( URL_0 ) (the short version afair: they know their own voices, and they know which sounds can be reflections of their voice to filter out the rest.)"
],
"score": [
105,
22,
12,
8,
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle"
],
[],
[],
[],
[
"https://www.bbc.co.uk/sounds/play/b09kxsds"
]
]
}
|
[
"url"
] |
[
"url"
] |
lp3igh
|
Why can't you fall back asleep despite not getting the full rest people need?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go93r7i"
],
"text": [
"It’s mainly because you’ve already reached deep sleep (REM) sleep by then, and waking up suddenly while in that state or even gradually usually triggers our brain then to our body that we no longer need to be asleep. That’s why it’s best taking a hour nap versus a 3 hour nap because in 3 hours you’re just about in deep sleep; waking up will make you feel sluggish and generally more tired versus if you only took a hour nap."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp445r
|
- How do we fight ERCOT's price hike?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"go97422"
],
"text": [
"> how is ERCOT able to jack up the cost per kw/h skyrocketing people's bills into the thousands without any consequences This is the downside of signing up for a variable rate plan knowing there isn't a set maximum rate, in a situation where you can't or don't want to reduce your electricity use during periods of extreme demand. Edit: adding that there apparently was a cap of $9 per KWH, which is still a huge increase over what normally costs closer to 9¢ per KWH"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp48b2
|
how people are born with green eyes?
|
I never thought about it earlier but how are people born with green eyes? Since the color green is a mixture of yellow and blue but the human body doesn't produce a yellow pigment which means it should be impossible for people to have such an eye color right?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go99176",
"go9trbz"
],
"text": [
"Just like plants are not made of the colours blue and yellow, so is the colour of your eyes not made from colours of your most favourite colour wheel. They are made from the presence or absence of melanin, the pigment that makes your skin turn brown. The absence of melanin make your eyes appear in a lighter shade such as green or blue. The structure of your iris decides if green or blue light gets reflected. Your iris can appear yellow-ish at some spots though for the same reason. If you want to learn more, educate yourself on how colours work on a painting-level and within the light spectrum.",
"Aside from the other answers, pheomelanin actually can look yellow under some circumstances (like blonde hair), so it's not quite true that people can't produce yellow pigment (actually it's blue that's the rare pigment in nature, blue in eyes comes from structural scattering of light rather than a proper pigment)"
],
"score": [
12,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lp4nf2
|
Why do we want to punch and destroy things when we are mad? And why does it make us feel better afterwards?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go9b0df",
"go9f07s"
],
"text": [
"Part of it is because of a desire to reassert dominance and control over your environment and those around you. Violence is a time tested method of getting short term results of obedience and submission, time tested beyond humanity, and extends across the entirety of the animal kingdom.",
"All emotions have both a purpose, and an energy level. For example, sadness/depression is low energy, and its purpose is to protect us from further hurt by causing us to withdraw/isolate; love is low energy, and its purpose is to create/maintain a sense of connection with another person; anxiety/fear is high energy, and its purpose is to keep us safe by avoiding danger/threats. Anger is very high energy as well, and its purpose is to get shit done — when something unfair happens, it’s that anger-energy that drives you to take action to correct it. This becomes problematic sometimes though - people can misinterpret their emotions, or mismanage that energy, leading to all sorts of issues. Learning to correctly identify thoughts vs feelings as well as learning healthy ways to channel that energy is a big focus in cognitive-behavioral therapy."
],
"score": [
22,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp533d
|
How do chain restaurants make sure all their foods taste exactly the same at each and every location?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"go9dyjp",
"go9i0z3",
"go9eity"
],
"text": [
"Its actually not that complicated. In fact the whole idea is to keep it simple. Your supply chain / ingredients: Can you order pretty much from a single source for a certain ingredient? Its gonna be the same. Or can you tell suppliers to simply make the exact ingredient you want? Sure. Its easy to source near identical ingredients, especially when you buy a lot, people want that business and will give you exactly what you want Your training: Can you train literally every person who works for you in the kitchen the exact same way? To follow the exact same procedure, assembly line style, time after time after time? Sure, in fact thats not that hard: Step 1) Cook burger patty 30 second on each side. Step 2) Apply mayo to bun 3) stack letuce, tomato, onion... and so on. Just follow the instructions. It just requires people to follow the instructions. In fact it may be the *easiest* way to cook it rather than to let individual cooks figure out the best way for each item. For smaller restaurants this can be much more difficult as it can be more complicated to continually source ingredients reliably and at the right price, you may have quite complicated preparations that don't exactly follow assembly line style and so on and your ingredients and menus may vary even day to day. One of the things that makes fast food and chain so easy is that you don't have complicated procedures, its just step 1, step 2...",
"A lot of restaurants across the US are supplied by the same few food vendors. Sysco comes to mind",
"Using the same supplies and the same recipes, and teaching every cook to prepare them the same way, does a lot on its own. Then on top of that you have to remember that restaurant food uses lots and lots of butter and salt, and that \"smooths out\" minor differences. Like, however much butter and salt \"a lot\" is in your head? They use more than that. Nope, keep going, even more than that."
],
"score": [
17,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp5pc3
|
Why do you hear a sound similar to the crashing waves of the sea when you put your ear in a glass/shell/cupped object?
|
Always remember the classic "Put your ear to a shell to hear the sea!", but what is actually the science it?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go9ngga",
"go9hyvh"
],
"text": [
"The conical shape of the shell amplifies ambient noise. It's why ears are shaped the way they are. And there's always ambient noise around us. The amplification, in this case due to size and shape, isn't neutral along all frequencies of sound. The frequencies it amplifies are somewhat high, and sounds like something called white noise (which is toneless noise, you have other types of noise like pink, brown, etc, which have tone). This white noise from the shell just so happens to sound like the sea. Hypothetically, if you found a big enough shell you should hear a much deeper (in frequency) noise.",
"There is blood flowing around in your ears. A seashell, or any cup-like object, acts like an echo chamber, and magnifies the volume of this bloodflow; which just so happens to sound like the water of an ocean."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lp78ig
|
How does bacteria get around so quickly?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"go9x6iu"
],
"text": [
"Bacteria are literally everywhere. Every surface around you, the air you breathe, the water you drink, all of them contain bacteria of various kinds. You have as many or more bacterial cells in your body as you do human ones. It's not that they \"get around\" in any active sense. They're just everywhere floating around, and rapidly grow once they find a niche."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp8zgm
|
why do some companies have different names for the same product for different parts of the world? For example, Lays/Walkers crisps, Lynx/Axe deodorant etc etc.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goa2ca6",
"goa20q0"
],
"text": [
"Each company will have their own reason. They will not be identical. However a common one is that one company buys another in another region and decides to keep the (old) name as it has good brand recognition. So if you already know brand X in your areas, even though brand Y buys them, if brand X is a cool brand, you know it, keeping the old name can be good so you don't have to re-introduce a new name to consumer Think of consumers being dumb. I am absolutely mentally retarded. Full retard. Not kidding. Because thats how they think of you. Now, you've been eating Walkers crisps your whole life, then one day, there' gone? ??? WTF happened? WTF are Lays crisps? I want my Walkers. Sometimes its simple like that.",
"It can have a variety of reasons. For your examples, Walkers was bought by Pepsi (who make Lays), and they decided to just change the chips but keep the name so people who liked Walkers would keep buying them. As for Axe, they had Trademark problems in some countries, so now in those countries it's now called Lynx (for that reason, Burger King is called Hungry Jack's in Australia). Another reason could be that the brand name is a play on words that doesn't work in other languages or that it's just hard to pronounce (for example, drive throughs are called drive ins here in Germany, because many Germans struggle with the 'th'-sound."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp9btl
|
Would a Solar Panel get Hotter if not Generating?
|
Consider a solar panel generating electricity. If all the wires were disconnected, so that it was not generating, would the panel itself get hotter, because the same energy from the sun is hitting it, but is no longer being converted to electricity? Or is the proportion of the energy that gets converted to electricity so small that it makes little difference? Is it related to the various wavelengths of light and radiation?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goa5efy"
],
"text": [
"Electricity can only be generated if you have a completed circuit. No completed circuit equals no electricity generation (no current). The temperature of the panel gets pretty warm simply because it’s dark,"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lp9dg3
|
How do closed captions work?
|
Does someone physically type everything in? If so, why do the words sometimes not match what was said, or even whole sentences? I'm watching a show & the line was about insurmountable odds but, the caption said unassailable.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goa3pp0",
"goan689"
],
"text": [
"Traditionally used to be typed by a person on prerecorded programmes. Now it tends to be done by a computer program much like how Siri or Google assistant can listen to your voice then transcribe it to text. Just like Siri etc sometimes someone has an accent that slurs certain sounds and the software doesn't quite interprete it correctly.",
"It depends, sometimes for live TV channels there's someone who types it. You can tell because sometimes they backspace and correct the captions. For things like movies, it's usually part of the broadcast. Since the script is known beforehand. Differences here could be that the script the caption is using is somehow different from the what is being said. For things like YouTube, they are experimenting with voice recognition. The same stuff that Alexa and similar use."
],
"score": [
12,
8
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lp9r3e
|
how do mountain tunnels hold on so well against hundreds of tons of rock above?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goaabku"
],
"text": [
"Another point is that the top of a tunnel is essentially an arch, which is a structure that can spread the force out across the whole arch and the entire length of the tunnel, so no one part of the tunnel is bearing a lot of force."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lp9wa8
|
Why can’t our skin just grow new skin when we get scars?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goa7kbj"
],
"text": [
"It does, the wounds that scar go through the skin and damage layers underneath that 1. Don't normally grow/shed and 2. Control the growth of the skin layer. You can test this by scratching yourself with a fingernail, hard enough to leave a whitish line bu not hard enough to draw blood. The line will disappear very quickly."
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpa5dn
|
How can we sense the proximity of a sound to the microphone in mono audio regardless of its volume ?
|
Lets say you have a mono recording of moving a speaker playing music at different distances from the microphone. No matter how you change the volume of the music playing through the speaker, you can still tell that the proximity of the speaker to the mic changes.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goaatiw"
],
"text": [
"When you speak, the sound reverberates throughout the room. The microphone picks up that reverberation. Because reverberation is the sound bouncing off the walls and around the room, the amount of reverb will be pretty even throughout the room (there will be loud and quiet spots, but that's beyond the scope of this answer). Therefore if you and the microphone are at opposite ends of the room, the sound of your voice will be at a lower volume relative to the reverberation so on the recording will sound like there's more reverb. Conversely, if you're close to the mic, your voice will be louder relative to the reverb. Basically, the further you get from the mic, the more reverb there will be on the recording. When you stand closer to the mic there will be less reverb and your voice will sound clearer and more detailed, but less full. Reverb is the main reason, but the tone of the voice is also a factor. Deeper frequencies travel further through the air, and spread out more compared with higher frequencies. The further you are from the mic the deeper and fuller the voice will sound."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpag5e
|
Is depression what takes away your energy/motivation? Or is it just the sign that you have none?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goaaglc",
"gobaohr"
],
"text": [
"With mental illnesses, frequently the characteristics of a condition are present in most people. The difference is a matter of scale. There are indeed some people who naturally seem to have more energy or more motivation than others. But not having energy or motivation is *also* a symptom of depression, and lack of energy and motivation caused by depression can be much more significant. We can tell this is true by how successful treatment of depression gives people more energy and motivation. If having no energy and motivation were simply the way that they were, we would see no change in that with the treatment of other depression symptoms.",
"Low energy, motivation is a symptom of depression. You can have low energy, motivation without being depressed though. Usually considered couch potatoes or lazy. Depression comes in many forms though. High functioning and low functioning. Some people are able to truck their way through life by suppressing their depression, but they are still depressed even though they go to work everyday, feed themselves and do the laundry. Others are consumed by their depression, they often call in sick to work, forget to eat, don't care if they have dirty clothes. Then there is everyone in between, and others who fluctuate between these moods. Regardless of where you are, it is important to be able to ask for help when you need it. Call your mom or friend and say please come help my clean my house, or just spend time with me, have some lunch. Call a hotline or someone you know if you dont want in-person interaction. It is always okay to ask for help."
],
"score": [
11,
8
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpanqm
|
How do spacecrafts send images from millions of kilometers away to the Earth?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goab4my",
"goabao1"
],
"text": [
"Radio signals. Just like the Internet, the image is collected digitally, in an image sensor (= camera). Then it's broken into packets and sent over a digital radio network.",
"We use something called the *Deep Space Network* which consists of large antennas at three facilities spread around the Earth. When the Earth rotates, the signal is passed from one facility to the next. There are also a few antennas in orbit to fill in some gaps."
],
"score": [
4,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpb49w
|
What's the difference between brown, pink and white noise?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goahysv",
"goafdb1"
],
"text": [
"Its all about the distribution of frequencies in the noise: **White noise** White noise includes all audible frequencies. Energy is equally distributed across all of the frequencies any person can possibly hear (about 20 Hertz to 20 thousand Hertz). It is good for masking unwanted sounds. Examples of White noise include: * whirring fan * radio or television static * hissing radiator * humming air conditioner **Pink noise** Pink noise is deeper than white noise and has upper frequencies reduced. It’s like white noise with a bass rumble. It has more power in the lower frequency bands than white noise does, and those strong bass tones make it sound less harsh to the human ear. It is considered good for falling asleep to. Examples of Pink noise include: * the sound of failing rain * gentle ocean waves **Brown noise** Think of brown noise like a deeper version of pink noise, with even more bass tones and low-frequency concentrated energy. It sounds dampened compared to white noise, but somehow stronger, comparable to hard ocean surf during a storm or the rumble of a brass instrument humming a low note. It is considered a good background for working. Examples of brown noise include: * low roaring * strong waterfalls * thunder If you are interested in what the frequency distribution looks like, [here are some graphs]( URL_0 ) that show the difference.",
"White = every frequency has the same amplitude Pink = amplitude drops with higher frequency linearly i.e. it's 1/f Brown = amplitude drops with frequency squared, i.e. it's 1/f^2 Fun fact, even though white noise got its name from having all frequencies in it (just like white light), \"brown\" noise is named after Robert Brown, who investigated particle motion, which can be described by brown noise."
],
"score": [
15,
12
],
"text_urls": [
[
"https://www.xpressocommunications.com/wp-content/uploads/2019/03/Blog-February_White-Pink-Brown-Noise.jpg"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpbbsm
|
Is there something about soap in particular that makes it hurt more when it gets in your eyes?
|
I understand that eyes are sensitive organs and the body wants to protect them from pretty much everything, which is why we have eyelids and tear ducts and eyelashes. But it doesn't hurt all that much to open your eyes in water. Is there something in particular about soap, maybe its hydrophobic/hydrophilic nature or its basic PH that makes it hurt more? Thank you, Signed: someone who got soap in their eye in the shower today.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goajvft"
],
"text": [
"Soaps are generally strongly basic, as bases are good for rendering the protein and fat molecules which we wash off plates and ourselves when cleaning. Breaking these molecules up allows them to be more easily wiped away. In addition, soap is a surfactant, which means it is capable of causing oil and water to mix by binding to both polar and nonpolar molecules. This means running water over a soap-soaked oil stain will remove it rapidly. This is also why we use dish soap to clean wildlife in oil spills. However, this is very unfortunate for your eyes, as the cell membranes in your corneal cells are also made of fats. Putting a dab of soap on them begins to literally render your eyes, which is incredibly painful specifically because that encourages you to dunk your head in water to wipe the soap off."
],
"score": [
29
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpbfb4
|
How does the chain reaction in a nuclear bomb end?
|
In a nuclear bomb/fission, particles crash into other atoms splitting them, causing the chain reaction and releasing massive energy. So why does the chain reaction end? Shouldn't the particles just keep splitting every atom nearby, continuing the reaction?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"goaianl",
"goafiu2",
"goafwuq"
],
"text": [
"The key is the massive energy release - that leads to the bomb material being dispersed, disrupting the chain reaction. **It's literally blown apart.** Imagine a room full of people, where one person farting causes 2-3 *nearby* people to fart. Once farting starts, the room smell becomes so odious farters become increasingly desperate and inventive in finding ways to escape. Once enough get out of the farting area, there won't be enough farts smelled to sustain the farting. If you're running the fart-a-thon, you design the farting chamber to maximize farting - trapping farters to get as much farting as possible before they escape (you also want no farting beforehand) **Edit:** Only a few materials release extra neutrons (and energy) when they are hit with a neutron. These are rare and need to be refined to high purity levels. Other materials don't release energy, recombine when split, or absorb neutrons. I know my analogy stinks - it only covers farters (nuclear fuel/bomb materials). Other materials can slow, scatter, absorb, or reflect neutrons. **There are a few main ways to enhance farting:** - Gather as many farters as you can (They used 1/3 of the electricity ever produced in the US and piled all the U in one bomb and all the P in another) - Compress the farters together so they can't escape before as many of them fart as possible (They use explosives to compress a subcritical core into a critical mass) - Get a few of the more noxious farters in a breakout room with a bean buffet, and once the farting starts, start them stampeding into the other room of unsuspecting farters (Use neurton-reflective materials to focus the neurtons from the first stage onto the second stage core. [Really scary stuff]( URL_0 ).) Critical mass can be converted into a spherical diameter, and it's [different for different materials]( URL_1 ). For process facilities and material handling (where you DO NOT want an explosion) the piping and vessels have maximum sizes to prevent material building into a critical mass.",
"Answer: When the 'chain' runs out of fuel. By it's very nature, chain reactions are able to continue b/c the by-products of the process generate the catalyst for further activity. When there's no more 'fuel', the 'chain' fails.",
"In general, smaller atoms take more energy to split than larger atoms, eventually you're using more energy splitting them atom then you get out of splitting it. Also, large atoms take more energy to fuse than smaller atoms. Eventually it needs so much energy the bomb can't make the conditions to fuse them. There was a legit concern that a nuke would cause the atmosphere to fuse, but then they did the math and figured out it wouldn't happen. The atoms in the air are too small to fission, but to large to fuse easily. Also the nuclear chain reaction depends on a lot of stuff being packed closely together, a nuclear explosion tends to push the stuff apart."
],
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13,
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5
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"text_urls": [
[
"https://en.wikipedia.org/wiki/W88#Design_revelations",
"https://en.wikipedia.org/wiki/Critical_mass#Critical_mass_of_a_bare_sphere"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpbubh
|
More and more people are buying electric vehicles. Presumably, these will be charged at home in the evenings. Will this overload the electric system due to higher demand?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goaj42t"
],
"text": [
"It is unlikely, since the buying of electric vehicles is not a sudden event. Consumption will ramp up slowly, and since power companies are already ramping up production to keep up with increasing consumption in other areas it's really no different."
],
"score": [
3
],
"text_urls": [
[]
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}
|
[
"url"
] |
[
"url"
] |
|
lpc85k
|
Why do songs randomly come into our mind?
|
I was making coffee the other morning, out of nowhere the line from the Monkeys, "Cheer up Sleepy Jean, oh what can it mean..." just came in my head.. I have not heard that song, thought about the Monkeys, been to a zoo to see a monkey, or even heard the jingle in a commercial in over 30 years probably... Why do particular lines of songs randomly pop in our minds without any recent connection to it? What sparks those memories?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gob7zv2",
"gobjs6i"
],
"text": [
"I can't do this one ELI5 justice, but there's a really good book called \"the ape that spoke\" that unpacks how brains work and how memories form - really good read. It's like a brief history of time but for brains. Trying to remember the book - you will have formed a memory when you heard that song, and it was linked to other memories by context, and something you sensed got close enough to that network of memories and associations to recall it. It might have been visual, olfactory, too. Not necessarily auditory.",
"Because sweet dreams are made of these. Who am I to disagree?"
],
"score": [
12,
10
],
"text_urls": [
[],
[]
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|
[
"url"
] |
[
"url"
] |
lpc8bf
|
Why do horses need horse shoes?
|
Other
|
explainlikeimfive
|
{
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"text": [
"Horses in the wild don't carry extra loads. Their natural habitat isn't paved or stone roads. When used by humans, horses bear a heavy load and walk on roads. Humans tend to make roads out of hard materials like stone (unlike grass or soil which would cushion the impact) Therefore the hooves wear and split much faster than it normally would. Horseshoes prevent this.",
"Horses hooves and the bottom of their feet are quite soft. They tend to travel long distances on hard surfaces and the shoes will mitigate long term damage.",
"To be able to carry extra weight. The hooves can split otherwise, which can travel into the flesh causing horrible pain for the horse.",
"Like you're 5: Think about how good it feels to squish your toes in a mud puddle and walk in the sand. That's what it's like for wild horses. Horses that live in captivity have to walk on hot roads, concrete, and gravel - often carrying or pulling a lot of weight (hundreds of pounds/kilos). Construction workers, weight lifters, runners, climbers, etc all have to wear specific shoes to protect their feet and prevent injuries just like captive horses need to wear special \"shoes\" on their hooves to prevent injuries.",
"If you’re interested I always found the [process]( URL_0 ) of putting on the shoes to be fascinating. I particularly like part were they use what’s basically a giant toenail clipper.",
"Work horses that pull or carry weight or horses that are on pavement or rocky ground a lot should have shoes on their hooves to prevent splitting or chipping. We kept our horses in pastures and never put horseshoes on them, just kept their hooves cleaned and trimmed like your fingernails.",
"Not all horses need horse shoes. Humans invented horse shoes when they realized that the feet of horses they owned were wearing down too fast. This caused pain to the horses and was bad for the people because the horse with sore feet is not good at its job. Have you even broken your fingernail, or cut it too low? Can you recall how painful that was? If a horse’s feet wear down too far, the horse will be in too much pain to walk, let alone work. So humans invented horse shoes to protect the horses feet from wearing down too fast. This was especially important on hard surfaces, like stone, and brick and asphalt or concrete. Another reason horses wear shoes is to help with medical problems in their feet. If a horse’s foot tends to grow in the wrong shape, a special corrective shoe can be made to correct the problem or support the foot. If a horse develops a crack in the hard outer layer of its foot (the part that is like your fingernail, only thicker) a shoe can hold the rest of the hoof in place so the crack doesn’t get worse. Special shoes are made for special jobs too. A racehorse may get shoes with cleats on them (similar to your soccer shoes). The cleats are little parts that stick out and give the horse a better “grip” on the ground when it runs, so it can go faster."
],
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24,
9,
6,
6,
5,
3,
3
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[],
[],
[],
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"https://youtu.be/NgjmISsxsMI"
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[]
]
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|
[
"url"
] |
[
"url"
] |
|
lpcrj6
|
Why do remotes starting working again once you hit them?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goapqh5"
],
"text": [
"One working theory is that oxidation forms on the battery contacts which causes a poor connection. By hitting the remote it causes the batteries to change position slightly and causes the contacts to rub against the batteries like sandpaper, cleaning the contacts. This is the same reason blowing into the classic Nintendo cartridge causes it to work. It actually has nothing to do with the blowing, it's merely the fact that removing and re-inserting the cartridge cleans off the oxidization layer on the contacts."
],
"score": [
14
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpdbd4
|
What makes string cheese stringy?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goat9g2"
],
"text": [
"String cheese is mostly made of mozzarella. When mozzarella is warmed to the right temperature and stretched, the proteins line up with each other. That makes them able to peel away in strings when the cheese cools down."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpdh88
|
If gravity distorts time how did this affect time right after the Big Bang?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goat03s"
],
"text": [
"That's one of the interesting and unanswered questions of physics. If the universe was dense and all matter was together did time move at a slower rate? It's possible, and probable, But the next question is would it have mattered? Since the universe was all equally as dense, all of space time would have been affected by this effect so it would it have made any appreciable difference? The problem is we can't directly observe the universe at that early age because light didn't exist yet, so it's hard to predict what was going on."
],
"score": [
15
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpeqh3
|
Why do humans as a species find it so easy to procrastinate even when it causes immediate and significant emotional stress?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gob0xd5",
"gob3313"
],
"text": [
"It's kinda pointless to try to look at it through a biological lense because biology isn't equipped to answer these kinds of questions, the reasons are mostly psychological. Usually we procrastinate because we're afraid of screwing up the task and ending up with a bad product. Maybe you have a great idea in your mind but fear it won't look as good when you start putting it on paper, or that you just end up ruining it. Perfectionism is a common problem. Or maybe the task is overwhelming and you don't really even know where to start, so you just don't start at all.",
"It also causes relief of stress when you convince yourself you'll do it later.. \"Shit, I gotta pay the rent. Oh, its okay. I got til the 5th..\""
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpex2x
|
melatonin vs multivitamins
|
If I take a melatonin it really helps me sleep. However I always see that multivitamins are ineffective because your body can’t absorb minerals/vitamins that fast, so you just pee it out. If that’s the case why does melatonin work so well?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gob2mlk",
"gob2r6w"
],
"text": [
"If I remember correctly, melatonin is not a vitamin, it is a sleep hormone. So comparing the two isn't really a great because they're completely different things. Its like saying \"If coffee keeps me awake, why does candy rot my teeth?\"",
"Because melatonin isnt a vitamin, it is a hormone. Hormone are chemical signals created by your body that \"send messages\" to other parts of your body, one example is boys during puberty get a burst of testosterone, another hormone, that signals the growth of facial hair along with the rest of puberty. So melatonin is one of those messengers. Melatonin in the body sends the signals to start putting the body to sleep/make you feel sleepy. So, by taking melatonin you're basically forcefully sending your body a \"its time to sleep!\" message. vitamins are totally different things that serve a totally different purpose in the body."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpferc
|
how do noise canceling earphones work
|
How does it work and how are they able to cancel out noise better than regular headphones?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gob6tvy",
"gob41q2"
],
"text": [
"To elaborate on clyde's answer for active noise cancelling: Sound waves can interfere with each other, just like any other wave. When one sound wave is telling a material to compress, and another sound wave is telling the same part of the same material to expand, the material just does nothing. It's like adding a positive number to a negative number. The more similar in size the numbers are, the closer their sum is to zero. Active noise cancelling headphones have microphones on the outside of them, and they record the ambient noise of your environment. This never gets stored anywhere - it goes right into a circuit which reverses the sound, like multiplying it by -1. Then that sound is played alongside your music through your headphone's speakers. Just to be clear, the sound doesn't get reversed in terms of time - what you actually need to do is shift the sound so that when the actual ambient sound outside has a wave that's going up, the 'reverse' sound has a wave that's going down. Whatever one wave tells your eardrums to do, the other wave will try to tell your eardrums to do the oppsite thing. This way all the ambient noise gets cancelled out, and your music is all that you hear.",
"I assume you're referring to active noise cancelling. Passive noise cancelling is just making sure the headphones/earphones are sealed up so noise doesn't get through. Active noise cancelling playes certain frequencies that help mitigate outside noise."
],
"score": [
47,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpg4cv
|
What does 'dry aging' meat actually do?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goba0jw",
"gocfs62"
],
"text": [
"It's essentially controlled decay. By letting the meat age in a controlled environment, the meat itself begins to break down in advantageous ways. Collagen is broken down by enzymes that affect flavor and feel. Longer the meat ages, the more moisture is drawn from the meat. The more moisture that is drawn from the meat, the more 'flavor' will be left concentrated in the meat that is left dehydrated.",
"How does dry aging not result in rotting meat?"
],
"score": [
7,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpg5fi
|
What changes when we die that causes us to decay?
|
Another way to look at it: what stops us from suddenly decaying while alive? This question sounds weird, I know. Just one of those odd thoughts I’ve been wondering.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gob7x76",
"gob9xe0"
],
"text": [
"Our immune system prevents us from decaying while we are alive. Once dead, there is nothing to kill the microbes without taking measures to preserve the tissues, like embalming.",
"I know we think of our digestive system as being inside of us, but it's actually really separate from our *inside* insides. So we have bacteria on our skin that is kept from getting in because of our immune system. And we have bacteria in our digestive system that is kept from getting in because of our immune system. Then, with death, tissues start to break down because there's no constant regeneration. Combine the tissue breaking down with the bacteria now being able to go where ever it damn well pleases and you're well on your way to decay. But people actually *can* decay while they're alive. And it's super bad. For example, gangrene or necrosis. Living tissue dies and decays. With routine cell death, the immune system consumes the dead cells and there's no issue. With necrotic tissue, the immune system can't clean up and is likely already battling an infection or injury that caused the tissue damage in the first place. When that happens, it's super important to remove the dead tissue because leaving it rot on a living body could lead to death. One way that's done is with maggots, just like with a dead, decaying body. Maggots love dead, rotting flesh. But they can't digest living, healthy tissue. So sometimes doctors use special medical grade maggots to eat rotting flesh off of people so they're left with a clean wound on healthy living tissue that can heal. So that's fun."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpgspv
|
Why wont cigarette companies just use less chemicals? For example, just raw rolling papers and tobacco?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gobbg1k",
"gobchmi"
],
"text": [
"Most of the chemicals are in the tobacco leaf. Burning chemicals is unfortunately not destined to result in healthy byproducts. There are no real simple ways to make the product safer (without expense)",
"Each of the [599 allowed additives]( URL_0 ) (in the US) to cigarettes have their own uses. Some are used to allow the burn time, others as preservatives. Then there are flavors, which are probably the largest group of additives. And there are some added for safety, such as making the cigarette burn out instead of keep burning when you fall asleep and catch the house on fire."
],
"score": [
4,
3
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/List_of_additives_in_cigarettes"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lphbxk
|
Magnetic pole flip? What happens?
|
I've been reading about this magnetic pole flip for years. Some scientists say it's imminent. Whats likely to happen if it does - from a technology points of view - are we talking satellites falling out of the sky, mobile network decimated? From an environment point of view - crazier weather? [ URL_0 ]( URL_0 )
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"goc0x4c",
"gobujxe"
],
"text": [
"The reversal of the Earth's magnetic field is a recurring phenomenon in Earth's geological history, the magnetic north pole moving to the geographic south pole, and vice versa. It is the result of a disturbance of the stability of the core of the Earth. The magnetic field then panics for a short period (1000 to 10,000 years) during which the magnetic poles move rapidly over the entire surface of the globe, or disappear, depending on the theories. & #x200B; During this transition, the magnetic field is very weak and the surface of the planet can be exposed to the solar wind, potentially dangerous for living organisms. If this were to happen today, many technologies using the magnetic field could also be affected. & #x200B; At the end of this transition period, either the magnetic poles return to their initial positions, it is then only a matter of a geomagnetic excursion, or they permute and one then speaks of inversion. & #x200B; The earth's field has reversed about 300 times in the past 200 million years. The last reversal was 780,000 years ago and the last excursion 33,000 years ago, no one knows when the next will happen.",
"Firstly the transition is rather slow, the pole migrates from north to the south, as it moves the area under the \"pole\" isn't protected from the rays from the Sun, but there are few other long term problems. URL_0"
],
"score": [
5,
3
],
"text_urls": [
[],
[
"https://youtu.be/QGTPr3CG6GA"
]
]
}
|
[
"url"
] |
[
"url"
] |
lpjlbg
|
If you have a low population of an endangered species, how do you get the numbers up without inbreeding or 'diluting' the original species?
|
I'm talking the likely less than 50 individuals critically endangered, I'd imagine in 50-100 groups there's possibly enough separate family groups to avoid inter-breeding, it's just a matter of keeping them safe and healthy. Would breeding with another member of the same family group* potentially end up changing the original species further down the line, or would that not matter as you got more members of the original able to breed with each other? (So you'd have an offspring of original parents, mate with a hybrid offspring, their offspring being closer to original than doner?) I thought of this again last night seeing the Sumatran rhino, which is pretty distinct from the other rhinos. Edit: realised I may have worded a part wrongly. *genus is what I meant not biologically related family group. Like a Bengal Tiger with a Siberian Tiger. Genetically very similar but still distinct.
|
Biology
|
explainlikeimfive
|
{
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"You don't. you don't have much choice but inbreeding, hoping there's no genetic abnormalities that's going to amplify, and then hoping there's never a disease that exploits their genetic similarities.",
"Usually they just go with inbreeding. The Chatham Island Black Robins alive today all descend from one female.",
"A quote about the topic: [The study examined 95 mammal species, 20 percent of which are endangered and 10 of which are on what the authors call \"the tipping point\" where they could be at the \"point of no return.\" That tipping point, according to the authors, is a species with a population below 5,000 individuals.]( URL_0 ) This means that normally, it’s extremely hard to bring populations below 5,000 back to safe numbers. If the breeding pool is as low as fifty, it’s nearly impossible to raise it back up. A certain percentage of the animals will be infertile or die before adulthood. Then, you have to consider why the population has gotten so low. If the species is going extinct because of habitat loss, that will still limit the amount of animals that can survive. In regard to your second question, evolution is constant. In this case, genetic drift is possible. This means that depending on the characteristics of the survivors, future generations may be different. Say you had 100 butterflies; 20% red, blue, green, yellow, and purple. Fifty randomly died, leaving 50% red, 30% blue, 28% green, 2% yellow, and 0% purple. About half of their kids will be red, and none will be purple. The species will have “accidentally” evolved to not have purple anymore. If this doesn’t happen, evolution will still happen, but it’ll take longer to notice.",
"There was a story on 60 Minutes (US) about the organized lengths that affiliated zoos from all over the world use to reduce inbreeding while growing small animal populations. They keep track of the most genetically diverse animals and only mate those while avoiding genetically close pairs.",
"Inbreeding itself is not going to cause much if a threat. If conditions are right, you can get a population back up from literally a single breeding pair. There are two issues with it: - Genetic defects: this is less of an issue than one would expect, since any frequently occuring and serious defect will be removed from the gene pool rather quickly. It might reduce the rate at which early generations can breed. - Smaller genepool - > less variety - > if conditions change, there is less variety to choose \"successfull\" variants from. This means the species will not be as good in adapting to changes for a certain time. This also means that diseases are more likely to wipe out a species, since less variety - > lower probability of resistant variants. Neither of those things will make a species go extinct on its own. However, with the usual pressure and competition going on in nature it might be just enough to tip the balance against a species - particularly now, with environmental destruction forcing species to quickly adapt or die out.",
"You don't. Genetic bottlenecking means that even when the numbers of a highly endangered species recover, it's at the cost of genetic problems. IIRC the African Cheetah is a prime example of this.",
"You also have to take into consideration that not all species are equally prone to dangers that come with inbreeding.",
"There's the rule (of thumb) of 500, and the rule of 5,000. Generally speaking, a population with 5,000 members can breed back up to sustainable numbers with out any significant issues. With 500, it can breed to sustainable numbers, but there will be significant genetic difference from the original population. Which can be the inbreeding issues you mentioned. But it's still better for the health of a species to exist with inbreeding issues than to not exist at all.",
"This is called a Genetic Bottleneck and it happens. Supposedly humans were reduced to only 3-10k individuals some 50k years ago.",
"Is it possible to extract what you need (sperm/egg) from existing specimen before it gets to the final 50? Then fertilize an egg in a lab, implant it into a living specimen to have a birthed young without the risk inbreeding?",
"Generally, the minimum amount of the species needed to avoid inbreeding is around 50, though zoologists would recommend at least 150",
"Today it was announced that scientists were able to clone successfully an endangered ferret whose genetic material was preserved from over 30 years ago. This will offer some genetic diversity into the endangered population. Another method is through crispr Gene manipulation. Although this is quite controversial, and costly. I can only see this being used as a last resort.",
"> I'm talking the likely less than 50 individuals critically endangered, I'd imagine in 50-100 groups there's possibly enough separate family groups to avoid inter-breeding, it's just a matter of keeping them safe and healthy. It doesn't work like that. There is no minimum number. If you are lucky and you got only two specimens, niehter of which have dangerous recessive traits - then you can breed them up to high populations. Ofc. said population will contain extremely similar specimens which comes with its own \"quirks\": * Pros: due to extreme similarity, you can organ transpalnt between specimens * Cons: due to extreme similarity, diseases will affect them the same way. Thus diseases will create much larger dips in the populaton before they evolve to coexist with the species. (Yes, parasites need hosts, so over time they evolve to be less deadly) Ofc. if you get unlucky, you can have a last pair of organisms, that cannot produce viable offspring. At the end of the day careful human selection - in terms of which individuals you allow to breed - can do wonders, when it comes to helping small populations to recover. & #x200B; & #x200B; > Would breeding with another member of the same family group potentially end up changing the original species further down the line, or would that not matter as you got more members of the original able to breed with each other? Good questions if that matters. There are plenty of conservationist with the \"genetic purist\" borderline nazi-esque mentality. Take the eurasian wildcat - which interbreeds with the common housecat. So much so that in some places over 25% of the wildcat genetic material is from housecats. However that doesn't lead to significant changes in the wildcat population in behavior or looks. So \"who cares?\" can also be seen as a walid answer to the \"is it an issue?\" problem.",
"Breeding doesn't cause issues in 100% of the offspring. If even two offspring do not have significant issues, they can continue to breed. Eventually, they become genetically diverse again as the differences start to add up and there's significantly less risk of genetic defects.",
"They inbreed. Despite its negative connotation, the notion that inbreeding always results in negative offspring is wildly out of control. For those that do not know, when 2 people mate, each of them share half of their genes, to create a person. 46 chromosomes in each human means we share 23 each. Let's say 1 of those 46 chromosomes in dad are a precursor to down syndrome. The parents mix their DNA and dad never shares that 1. The child is safe. But what if dad mates with his sister, who ALSO has that 1 precursor to DS? Well now there's a chance that both of them could pass it on. The chances have doubled for that offspring to have DS. However, maybe neither of them pass it on, and everything is ok. That's the risk you take with inbreeding. (This is grossly simplified)",
"I was just listening to the Meateater podcast from 2016 and they were talking about North American Caribou. At the time they had 12. It's up to 40 now with no genetic drift. So thats good news.",
"I'm not sure if this is the reason you brought it up, or if it's just good timing, but there was a similar issue with the black-footed ferret population that was solved with cloning. Yeah, you heard me right, *cloning!* The black-footed ferret population has been increasing, but every current living black ferret today can trace its ancestry back to about seven ferrets. So what did researchers do? They took frozen eggs from a ferret that existed in the 1500s and cloned a new ferret! Hopefully this new ferret will bring enough genetic diversity that it will ensure the species has no inbreeding problems in the future."
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"https://blogs.scientificamerican.com/extinction-countdown/australian-mathematicians-say-some-endangered-species-not-worth-saving/"
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[
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[
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lpk5j5
|
Why are there not more large predators in Australia other than the Dingo?
|
Why do we not see large predators in Australia like lions/tigers? Were large predators just completely wiped out by primitive humans or are there other factors like the way land was split?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goc0qgq",
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],
"text": [
"There were large predators on Australia until relatively recently. There were also large herbivores. Much of the \"[Australian megafauna]( URL_1 )\" went extinct after humans arrived (~65,000-70,000 years ago), either due to direct effects of humans (e.g., hunting) and/or due to changing climate (not related to humans). A few examples of these organisms include a [lion-sized predator]( URL_2 ) and a [monitor lizard the size of a crocodile]( URL_0 ).",
"Two things. 1. Evolution between predators and prey is an arm race. It's not a race to be the biggest. It's a race to be able to sustain your population. Doesn't matter how. When one species manage to reach its goal, it'll focus on other things. As such, once a predator can acquire enough food to grow its population, it'll stop evolving bigger unless his usual preys start growing bigger as well. In the same way, a prey won't grow bigger if they have another mean of sustaining population (like having so many offspring that the predators can't eat them all). 2. Efficiency is key in nature. Most animal will try and not waster resources. Being big needlessly will waste resources. With these two, we can find our answer. There is no point for a predator to grow big unless it has access to bigger animals to hunt. Pack mentality also mean the ability to take down bigger prey than yourself to an extent. And growing big wastes resources. So by default, animal will try to remain as small as possible while reaching their objective: Sustain population. Predators don't need to grow bigger if they already have enough food available for their weight class. Specific cases can be made for races like humans that have such an overabundance of food that they no longer care about more consumption. In these rare instances, growing big is just a way to become stronger since food is no longer a concern."
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"https://en.wikipedia.org/wiki/Megalania",
"https://en.wikipedia.org/wiki/Australian_megafauna",
"https://en.wikipedia.org/wiki/Thylacoleo_carnifex"
],
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]
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[
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lpl4uy
|
why can we hear everything clearer after we yawn or sneeze?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gobzsus"
],
"text": [
"Swallowing or yawning opens the Eustachian tube and allows air to flow into or out of the middle ear to help equalize pressure on either side of the eardrum. You “hear better” because the pressure behind the eardrum equalizes with outer pressure, allowing it to vibrate more freely, which allows it to be more sensitive to sound."
],
"score": [
45
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[
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[
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|
lplsdv
|
Why are the bones of our limbs structured the way they are?
|
The upper half of our limbs have a single bone, and the lower half has two. Why is this? Why isn't it one, or the other, or reversed? To look at a skeleton it seems to make sense, but I don't know why I think that. Maybe it's just because I've always seen it that way?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"We inherited the arrangement of the bones in our arms and legs from our ancestors all the way back to the time when they were fish and those were lobed fins. All four-limbed land animals with bones have inherited that arrangement and made use of it. Some have bones fused together, some have lost the limbs altogether, some have found ways to make use of the bones in ways where the serve different functions in terms of muscle attachment and stuff, but we all kept the same blueprint that some fish came up with to swim better.",
"I believe having two bones ensures our limbs can rotate efficiently. If you look at the forearm structure, the radius and the ulna completely cross over each other when you rotate your arm, giving more freedom of movement. To an extent, the tibia and fibula have the same purpose in the lower leg, even though it rotates less. As to why, I'm not sure if there's any particular reason other than evolution adapting and growing with what's already there. Bone structure of land animals mostly follow that rule of doubled bone lower limbs, since land animals exist.",
"I love the two different types of posts. One, evolutionists speculating on the origins, one interpretation of the question. But given the context, I thing the second group understood OPs question. The wrist is a hinge. As others have said, the two bones in your forearm allow your hand to rotate do. Those two bones are attached with ball sockets and together allow a flexion while also retaining a good amount of strength, unlike the shoulder joint. A shallow ball socket like that one relies on good connective tissue and muscle much more iirc",
"Having two bones by the hands and feet is what allows you to rotate them. Take your hand and try out the range of motion you have without that rotation. We have it because it is an evolutionary advantage. The additional range of motion makes a lot of normal tasks easier. If you want an example. Try to eat an apple without rotating your wrists."
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|
[
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lpm1zp
|
why do ferromagnetic substances not break apart
|
I’m a student in yr 12 physics and a question has been confusing me for awhile. As far as I understand for a ferromagnetic substance (like iron) to be magnetic all of the magnetic poles must be aligned. Why does each atoms pole not repel from each other like in a crystal latice when you ad pressure and get the + and - atoms to line up.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gobyg0p",
"gocx4n8"
],
"text": [
"So in transition metals there exists a thing known as \"metallic band theory\" that, as simply as I can put it thinking back to my inorganic chemistry class, basically means that the electron orbitals of the individual metal atoms are so close together that they share electrons quite easily (this is also why they are so conductive). At this point the intermolecular bonds between the metals are significantly stronger than the magnetic forces between the poles (as opposed to the observed behavior in ionic substances.)",
"The force from the magnetism is not enough to overcome the bonds within the material. Imagine pressing two magnets together in this arrangement. Sure, it's difficult, but it's not as difficult (as much force) as RIPPING A SIMILARLY SIZED BLOCK OF IRON IN HALF."
],
"score": [
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4
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|
[
"url"
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[
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lpm7gm
|
Why does everyonw say you need a surplus of calories to gain muscle?
|
Alright, so I’ve been losing weight with lowcarb and most of the time having a calorie deficit. I also work out, and I see results. Why is it that literally everyone say you NEED a surplus to gain muscle? Whats the actual «math» here?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gobzi4k",
"goc8bcy"
],
"text": [
"The maths is that building muscle requires calories, like any other process in your body. A low carb diet is somewhat irrelevant, you are still getting sufficient calories. High protein diets are better for muscle growth than high carb anyway. The reason why it is a good idea to eat more - especially proteins - post workout is because of an amino acid called leucine. This is the \"switch\" that lets the body build muscles. You can't synthesise it, you have to get it from meat, fish, dairy, beans or tofu. It's also something that gets depleted post-workout. So if you workout and don't eat afterwards, you will build muscles more slowly than you would do otherwise. You will still build muscle, in the same way if you put a pan of water on half heat it will still boil. But you are not giving your body the tools to build the optimum amount it can do naturally. Obviously if you starve yourself you will not build muscle and eventually your body will cannibalise the muscles you have. This is most evidence in anorexics, who often do excessive amounts of exercise but have severe muscle wasting.",
"You don’t need a surplus to gain muscle, but you will dramatically reduce the amount of muscle gain you have by having one. The body hates having muscles, they use up a huge amount of precious calories just by existing, which is why if you don’t need them, you’re body will destroy them for energy as soon as possible. Obviously if you’re fighting tigers everyday (or lifting weights, shhh your body doesn’t know what you’re actually doing) then you need muscles to survive, and so your body will reluctantly build them for you, if at the same time you have a calorie surplus then no worries! You can afford to build them anyway. But if you’re running a calorie deficit then you become a penny pinching Tory when it comes to building muscle, as obviously you can’t afford them. You will also notice a difference in muscle gain by losing fat through a calorie deficit. Not because you have more muscle, but because you have less fat to hide it."
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[
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lpn64w
|
how come we can use telescopes to take long exposure images when the world spins?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goc2rsj"
],
"text": [
"Modern telescopes are computer controlled so you can track an object across the sky easily enough. The Earth isn't rotating that fast so it's not really a big issue. Or you can just let it blur and get cool images like [this]( URL_0 )"
],
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"https://apod.nasa.gov/apod/image/0609/startrails11h_hambsch_c90.jpg"
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[
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|
lpnpso
|
Do you go unconscious and die instantly the second your heart stops? If so, what causes that to happen instead of taking a little while for your brain to actually "turn off" from the lack of oxygen?
|
Like if you get shot in the head, your death is obviously instantaneous (in most cases) because your brain is literally gone. Does that mean that after getting shot directly in your heart, you would still be conscious for a little while until your brain stops due to the inability to get fresh blood/oxygen to it?
|
Biology
|
explainlikeimfive
|
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"No you don't. We often reset the heart in ED using medication or electric shocks if people have SVT - basically a super fast heart beat. When taking the injection the heart stops for a couple of seconds - sometimes more - and when it restarts it often goes back to normal. People do not go unconscious during the effects of the injection but they will always feel absolutely awful until the heart starts again. So no. We do not go unconscious as soon as our heart stops. We will go unconscious as soon as there isn't enough oxygen in the brain.",
"Actual ELI5: the heart is like the motor of a car. When you stop giving gas, you don't immediately stop. But if you don't start the motor again eventually you'll stop moving",
"I can actually chime in on this. I had a cardiac arrest in 2018 and was rescued by a passer by. I dropped because my heart stop, but I started Agonal breathing. Your brain stem senses the lack of blood and sends out pulses I believe. My savior did CPR for 18 minutes and then I was shocked in the ambulance.",
"You pass out pretty quick but the death part is not necessarily as instantaneous as you might think. Your body actually has several minutes worth of oxygen stored up (which is why a few minutes of hands-only or compression-only CPR done before rescuers with equipment arrive actually helps)",
"Yeh exactly it depends what you mean by death. We used to think of it as a single event, and now more so as a process, as we discovered ways to bring people back from what we used to think of as ‘dead’. So if you get shot in the head, we say death is instantaneous. It seems obvious, but unless the bullet hits a specific part of the brain, the heart will beat for a little longer afterwards, your liver might not notice for a while etc, but we have no way currently to save someone who’s brain has stopped working due to bullet damage. If your heart stops (let’s say from cardiac arrest instead of a bullet for this one) then the clock continues for the rest of the body (I say continue as they say we’re only ever a few minutes away from death, but each time we breathe this resets the clock). Each minute your heart is not pumping (either by itself or by CPR or something) increases your chances of dying by 10% I believe, so your body still has oxygen in it, this is quickly used up, and you’re not replenishing it, then your cells and organs start to die due to lack of oxygen. At some point (and this is an ever moving point) there will be a stage where our current medical capabilities will not be able to reverse the damage that has been done, and that point we call death. But that’s what’s important, not the time, usually it’s a matter of minutes, but if you you have a cardiac arrest and fall into a frozen lake, breaking the ice and being surrounded by near freezing water for example, it could be a matter of hours, as the rate at which your cells die in that situation slows dramatically.",
"You go into shock, so while technically you remain alive for a little while, in practice you won't really be aware of so much - not in the way you are normally.",
"Slightly off topic but anyone who really wants to scare themselves should go read about CPR induced consciousness. I personally have been unlucky enough to see a man open his eyes while we were doing cpr on him. He also bit the lyrangoscope when the doctor tried to intubate him. And yes we were absolutely sure he was dead and in need of cpr. This is the same man that confidently walked into our cardiac room and said \"I am having a heart attack, this is my fourth one and I am going to die this time\". He was right. Some areas are actually looking into sedation protocols for cardiac arrest, though I'm unsure if any have been implemented.",
"I experienced this... you def. are conscious. When I was pregnant I had undiagnosed gestational diabetes. It messed with me in many ways, one of them being heart arrhythmias. One day I was at a park with my mom and my first kid and i felt really “off”... so I returned home with them... once there I went into a bedroom and laid down. My heart started racing, then it did a loud THUMP and dead stopped..... I was like what the fuck... I was all alone in the room and knew my heart wasn’t beating and oh my god I’m going to die and I can’t even get up to tell anyone, they will just find me dead.... I started to count, knowing things would go black soon... I got to about 10 seconds and started to feel tingly like I was passing out, and I’m thinking fuck so this is how It ends....then two huge THUMP! THUMP! And then it just started beating regularly, the tingling went away and I’m left thinking HOLY. SHIT.",
"I had a major heart attack while running. I lost consciousness and fell like a ton of bricks. Skinned knees and small bite on my tongue. I was out for about 20 seconds when I came to (cardiologist said my heart stopped and was “stunned”. I came to with no assist which was witnessed by several medics. It was like a dream but it wasn’t like Fred Sanford yelling “I see the light Elizabeth.”",
"You're aware for at least a few seconds afterwards. When I was 6 years old, chasing some kids on the playground, my heart suddenly stopped beating. It was pounding hard as I ran, and then the sudden lack of pounding made me stop cold. I put my hand on my chest, and everything started to look splotchy. I remember a ring of blackness in my vision took over, and grew from the peripheral inward, until all I saw was a pinpoint in the center of my vision. My knees must have buckled at that moment, because the last thing I saw was myself falling involuntarily. I hit the ground, and felt this extremely hard, painful BANG in my chest. I don't know if it was from the shock of hitting the ground or my heart just turning itself back on, but the beat was back, and my vision returned immediately. I was totally freaked out. Everyone was staring at me wondering why I just stopped running and fell. Yard duty teachers were walking up to me, but I was too embarrassed to tell anyone what had just happened. I remember my chest seriously hurt the rest of the day, but it was years before I told anyone. Also, unrelated, I had a dream in my mid 20's where I was in France, dressed in rags, different body than mine. I was on a platform in front of tons of cheering people, full on about to be executed via guillotine. I remember the sound and rumble of the blade as it was released and falling. The strike. And I vividly remember seeing everything and everyone's faces tumble as my head rolled off the short platform. I knew I was dead. My sight faded as my head was in mid-air, and was gone before it hit the ground (or basket-I don't know). I know it was just a dream, but I have really searched for all these years for confirmation that that would be an accurate experience for someone going through that. It seems to add up. It was a terrifying thing to wake from. I don't recommend it.",
"It takes around 6-12 second of no heart beat before you black out (depends a bit on how good your body can handle changes in blood pressure). Your brain needs a certain blood pressure to be conscious and your heart beating Is what makes that blood pressure. So yeah, you may be conscious for a few seconds while your heart is stopped before you blackout and then die if it doesn't restart (or get cpr) within a few minutes. It's pretty haunting to watch. Here's to dying in your sleep.",
"No, you don't. You stay conscious for a few tens of seconds. Apparently, back when smoking was common and good safety procedures were not yet universal, you'd occasionally find an electrical maintenance person dead next to a fuse box, holding a cigarette. The maintenance person had touched a live wire inside the box with their right hand while holding the grounded metal of the box open with their left hand and thought they'd received a non-fatal shock, when the shock had in fact silently stopped their heart. Then they'd start feeling tired from insufficient blood flow, and get out a cigarette because nicotine is a stimulant. Then they'd fall unconscious and eventually die.",
"My biggest fear upon death are the \"Death Dreams\". The state the brain is in when it is deprived of oxygen just before death.",
"Depending on the efficiency of your heart (ejection fraction and a few other parameters), if your heart stopped, your pressure would tank and you would lose consciousness pretty quickly, although, you would not be dead or even brain dead for a few minutes. The pressure created by your heart adds to the ability of your body to exchange oxygenated blood with deoxygenated blood! Source: pacemaker technician.. sometimes people go sleepy if you run a test too long! 😅",
"It all depends upon what we consider \"death\". A good example would be chickens, which are known to run around a little after completely severing their heads. The running around is a muscle reflex thing. It is the basis of the \"running around like headless chickens\" phrase. Are they dead? Depends on the meaning.",
"There were some interesting experiments done back in the days when guillotining was popular. They wouldn't be considered scientifically rigorous by todays standards but it goes to show that your question has been thought about for a long time. Probably the most famous experiment was when a French chemist called Lavoisier agreed to keep blinking after his head had been cut off, to show that some spark of life still existed and to gauge how long it might last for. The story goes that he blinked for 30 seconds.",
"It just seems that way because that's how death from shooting is often portrayed in movies (to avoid showing suffering...people just 'turn off' when shot in movies, quite often). I think your brain has oxygen for at least 10 seconds or so even if your blood suddenly stops flowing. My dad had a repeat heart attack while in an ambulance once, and he was still conscious when they zapped his heart back into action with the defibrillator after it stopped beating (Edit- as corrected by others, his heart didn't actually stop beating). Ouch!",
"I'll start with saying that getting shot in the head is not an insta-death like it's shown in games. It really depends on what hit you (if it was a rifle or a handgun bullet, what bullet type) and where did it hit. If you get hit the brainstem which is located at a spot between your head and neck you will get paralysed instantly, will lose consciousness fast and die due to lack of oxygen shortly later (about 5 minutes). If you get hit in other parts you may not even notice it - when a part of you brain that does the reasoning gets damaged - you'll act as an automation going about your routine. Quite a few people survive headshots with handguns e.g. in suicides. & #x200B; With a heart it's a similar gamble - if a rifle bullet explodes your heart you will lose consciousness in matter of few to maybe less than 20 seconds because of sudden blood-pressure drop (like when you stand up too fast). If there is a penetrating would that doesn't stop your heart from pumping at least some blood you will be conscious until you bleed out enough. Once again you will die once your brain is sufficiently destroyed by a lack of oxygen.About 5 minutes in first, even many hours in the second case.",
"The brain *very quickly* notices that the oxygen level sinks, and breathing goes through the ceiling. Without much success, though. You'll get an adrenaline boost. But you stay conscious for a short while. But that's not fun, as there is only one thing on your mind: *PANIC*. I can tell you, it's not funny. 0/10, can't recommend. I was lucky, my heart restarted from one of the fail-safe circuits the body has, or else I would not type this.",
"My heart has stopped a few times but came back on its own. The experience is one of mild panic while fading to black over some seconds. Then my heart picks back up again beating very fast and I’m full of adrenaline and then actually feeling panic. Also had my heart go to over 300 bpm and needed to be shocked back into rhythm. Im not a drug abuser or anything, I just have a sinoatrial node that likes to do its own thing.",
"My father was hit by a car while riding his bike when I was 7 (I'm now 48 and he is still with us). I saw him in an upside bed right after he was admitted with a halo on- blood trickling into a pale on the floor. My dad had numerous hospital emergencies. Off hand I can think of 4 times his heart stopped and he had to be resuscitated. Each time when his heart stopped, he said he heard everything the doctors were saying. He also said there is extreme pain as the body loses its oxygen. My dad can never tell me how long he's been under, but he told me he heard all of the conversations so figured it was at least 5 minutes each time. Scary shi*!!!!!!",
"Things that stop your heart are often doing other bad shit too. Sometimes your brain intentionally shuts down to preserve itself if there's, eg, a sudden drop in blood pressure.",
"I’m late, but I work in an ICU as a nurse and not too long ago had someone die on a BIS monitor, which is basically a simplified EEG for monitoring brain waves as a way to guide sedation/paralytic choices. We lost a pulse, did compressions, failed to revive him, and then I slowly watched his brain function drift off to 0 over the next few minutes.",
"So, this has happened to me. I had once an Epileptic seizure where my heart stopped for two minutes, because my brain was sending out way too many electrical signals. It's not something I think about often, because obviously I came back. I wasn't consciously there for it. I was lucky to be surrounded by 30-ish people who were looking to become first responders, and had that of type of first aid training; we also were at a place with an AED. My outcome could have been way worse, basically. My episode lasted ten minutes, including the two where my heart wasn't beating. I'm very lucky because I was in the right place/right time, and everyone knew what to do and how to use an AED. I believe the actual window for brain death due to lack of oxygen is approximately 15 minutes, if there are no compressions or resuscitation being done. So you want that to be happening ASAP.",
"As others have stated, its the nutrients in the blood we need. An example with a drastically different timeline: if your hands don't work, it becomes substantially harder to fed yourself. While not having working hands is why you can't eat, you'll starve because you can't eat, not necessarily because your hands don't work. We even have machines that we can hook people up to that keeps them alive without a heart. Its like an artificial heart in action. CPR is our attempt at circulating the nutrients that your body and brain needs to be healthy and feed. We're taught that the brain is the diva of the body. Your heart can actually be \"malnourished\" for days without you going unconscious. Sometimes people have heart attacks without ever knowing. Your brain on the other hand, doesn't like going more than a few minutes without food.",
"Death is never instantaneous. It takes time for oxygen to be consumed, and subsequent irreversible damage to occur to any part of the body. Suppose your heart suddenly stopped with no preamble; you would remain not just alive, but conscious, for at least several seconds. You'd remain retrievable for a couple of minutes longer. If CPR is started in that timeframe, the retrievable period could be greatly extended. If paramedics arrive and proceed with advanced CPR, it could be extended long enough to get you to an ED, and there you could be placed on heart/lung and be retrievable for much longer, assuming too much brain damage didn't occur. Even if it did, it's hard to say that you're *absolutely dead,* as cells will continue to live on so long as life support is continued, although the organ itself may no longer be capable of performing its intended function of being home to a conscious personality. I think most people are more comfortable seeing things as black and white, yes or no, *dead* or *alive,* and we aren't comfortable coming to terms with the gray areas in between. But they are nonetheless there. Nearly always, however, the human body won't linger in those in-between states without outside help. Biological organisms are systems of smaller living elements that stay alive by cooperating with each other, uniquely contributing, and all regulated by a feedback loop. This makes it self-regulating and self-repairing, but if a key system is pushed over too far, the rest of the system will collapse. Therefore, a living organism is always pushed toward recovery or death naturally, with little dwell-time in the middle."
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lpnxhn
|
How did the Big Bang not immediately collapse back into itself as a black hole given the massive density?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gocxv02"
],
"text": [
"The early universe was uniform, there was no real gravitational gradient. By the time small fluctuations had enough time to become relevant inflation pushed everything to far away to create a black hole. It is also important to remember that the big bang does not start at t=0. At best, and arguably wrong, the big bang started at t= 10^-42 s."
],
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9
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|
[
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[
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|
lpp4sn
|
why do I/we feel extremely dizzy and uncomfortable after a big stretch?
|
Other
|
explainlikeimfive
|
{
"a_id": [
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"text": [
"You might be experiencing a drop in blood pressure, especially if it’s happening shortly after you stand up."
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"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpqgjo
|
How long does it take for a meteor to fall to Earth after entering the atmosphere?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gociiee"
],
"text": [
"Depends on how fast it is, wich angle it enters, even the shape and size wich influence air friction to inertia ratio"
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lprasm
|
What makes Earth’s core hot? Why isn’t it just a cold blob made up of metal and minerals?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"goclxu3",
"gocmail",
"godcbiq",
"godtp8r"
],
"text": [
"Two major reasons: 1. The earth was formed as a result of accretion. Small particles gradually attracted each other due to gravitational forces and formed bigger objects. This process accumulated a lot of heat; when two objects collide, heat is generated. And as a majority of the heat was retained and never lost, the earth's core remained hot. 2. However, a majority of the heat ( > 90%) is produced through the **decaying of radioactive elements**. The nucleus of unstable elements like U238 (Uranium) gradually break down, releasing energy.",
"It will become a cold blob made up of metals and minerals eventually, it's just so phenomenally large that it takes a very very long time to cool down. The Earth was formed quite a long time ago by a bunch of space rocks smashing together. When space rocks smash together, they heat up, because collisions produce heat (search youtube for \"slapping a chicken until it's cooked\" for an amusing demonstration of this). Get a lot of space rocks smashing together over a long period of time and the resulting big space lump gets so massive and so hot it rearranges itself into a roughly spherical shape under gravity and separates out into layers based on density. Hot things cool down. You can observe this by for example boiling some water, pouring it into a mug and just waiting. It just takes a really long time for big things to cool down. Takes even longer when the big thing has the equivalent of a bunch of nuclear generators inside it generating extra heat.",
"Two reasons: 1. Before Earth came together, it was a bunch of rocks far apart. In order to move towards each other, the rocks borrowed motion energy from gravity. When they ran into each other, the motion energy turned into heat energy, just like rubbing your hands together turns motion into heat. Part of the heat in Earth's core is leftover heat from that process, which is still there because the Earth hasn't had time to cool down yet. In fact, compasses work because the Earth's core turns itself into a magnet as it cools. Compasses don't work on Mars because Mars is smaller, and so has already cooled off enough that its core isn't partly melted. 2. Rocks have a bit of radioactive stuff in them, and radioactive stuff warms itself up by breaking apart big atoms into smaller ones. Really radioactive stuff like some kinds of plutonium can get hot enough to glow even when it's in small pieces, but for ordinary rocks the warming is so tiny that you don't notice it unless you have a whole Earth worth of rocks in one place. Without slightly radioactive rocks warming themselves up, the core would be a lot colder than it is.",
"There are many different factors for this: 1. Surface area to volume ratio: The bigger an object, the slower it cools because it has only so much surface area from which heat can dissipate. The earth, just by virtue of its size, still retains heat from its formation 4 billion years ago. 2. Once the earth cooled enough, its outer layer solidified into the crust (rock), which is an excellent insulator and made it even harder for heat to escape, effectively acting as a blanket. 3. Earth is surrounded by a vacuum where you can only lose heat via radiation. This is extremely inefficient and takes an insanely long amount of time. It's also the same reason why people don't freeze instantly when exposed to outer space. 4. The tidal force that the moon exerts on the earth converts earth's rotational energy into heat and warms the interior. This process is called tidal heating. A good example would be Jupiter's moon Io. When the moon was young, an earth day was just 6 hours long, meaning it was spinning 4x as fast. Now, all these years later, all that energy has been converted, and continues to be converted, into heat. 5. The earth has a lot of radioactive elements in the core which decay and release energy, warming up the other layers. Now not all of these factors contribute equally and perhaps some play a much bigger role than others, but yeah, because of all of them, even after all these years, the earth's core is still hot."
],
"score": [
48,
12,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lprfny
|
How do we know if a species is really extinct, like have we checked everywhere?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gocngi1",
"gocsvn5",
"gocn8a0"
],
"text": [
"Haha I love the wording of the question, like ‘have we checked under the sofa’. But yeh it’s a good question! And the answer is no we don’t know for sure, and there have been times in the past where we’ve declared a species extinct only to find it thriving somewhere. The more we know about the animal though the more certain we can be about our evaluation, if we know it only resides in certain habitats, or can only survive in certain places etc, but yeh animals surprise us all the time so can never be sure. As a side note we don’t even know how many species exist, we only know there’s a lot we don’t know about, we haven’t checked everywhere by a long long way.",
"All scientific statements are always \"to the best of our knowledge\". Science is always willing to be proven wrong. When a study concludes that a species is extinct, that means that it's extinct *as far as we can tell*. If more members of that species are discovered later, then the study was just wrong and it's not extinct after all (but if only a handful are found and no more, then it's \"about to go extinct\").",
"This is a very good question that even scientists working with this is wondering about. It is very hard to estimate the popluation size of a species, especially when there are so few of them. For some species we do know exactly where they live and can easily search their entire habitat to count them. However a lot of species have big habitats that is hard to search and they themselves are quite hard to find. This means that we can not actually know how many remain. But we know how hard we look and how long since we have found the last evidence of their existance so we can come up with some estimates. But it can take many years before we finally realize that a species have gone extinct and even then there may be speculations and people searching for long after. There have also been a few cases of discoveries of species that were thought to be extinct."
],
"score": [
9,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lps9tu
|
Why is it that when a new cellular network comes out (4G/5G) the previous version seems to be completely obsolete?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"god3l3e"
],
"text": [
"Something is not right here since the previous generation should be largely unaffected for some time and there are plenty of 4G/LTE phones (most of them in fact) in service without trouble. (AT & T's 3G network is still online until next year actually.) I can't tell you for sure but troubleshooting that issue is likely beyond this subreddit and will be device/carrier/location specific."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpsjgz
|
Why can't rockets just go straight up to space instead of having to curve?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gocr3r8",
"gocrlp7",
"gocrbu2",
"gocs98r"
],
"text": [
"Because going to space per se isn't the goal, what you really want to do is go fast enough, high enough up, that the earth curves away faster than you fall. The height itself doesn't really matter, but it's indirectly very important because we want to get to a height where atmospheric drag drops to basically nothing. If you can manage that, then you're orbiting, which is a lot better to do because you won't need to burn fuel anymore to resist earth's gravity. You're in a free-fall, but missing the ground. If you did it the other way, you would just be in a free-fall when you stop burning fuel",
"The classic analogy is thinking about shooting cannonballs. The faster you shoot them out, the farther they will go before falling back down due to gravity. If you shoot them fast (technically accelerate) them) and far enough, the surface of the Earth will curve away so much that the cannonball won't hit the Earth as it falls. This is called an orbit, and the cannonball will keep falling and keep missing Earth forever. In the same way, it is a rocket's sideways speed that matters to get it into orbit",
"To leave Earth and stay in space, you have to be in orbit. To be in orbit you have be travelling really fast. Now, if you were to fly straight up, you would go faster and faster as you 1) got fuurther away from Earth's gravitational pull and 2) got lighter as you burned all your fuel. But eventually you'd run out of fuel and you wouldn't be travelling fast enough _around_ the planet, and you'd slowly be pulled by Earth's gravity back to the ground. If you want, think of being in orbit as constantly falling back towards the Earth, but since you're travelling so fast sideways, you constantly miss it. But the Earth still pulls you towards it, but you keep missing it - i.e. you travel in a circle around it, constantly falling towards it, but missing. Anyway, this is only possible if you're travelling fast enough. Like 17,000 mph fast. Hence sideways not straight up. edit: 17k mph not 7k mph.",
"Because up usually isn't where they want to go. If you go 400 km straight up that would be easy, but once you get there you would immediately fall back down down again as soon as they stopped their engines. You don't want to go up. You want to stay up for more than a few moments. You want to go into an orbit. Once you are in an orbit you don't have to do anything anymore and still stay as high up as you are. At 400 km altitude (where the International space station is), you would need to go extremely fast sideways to be in a stable circular orbit. You would need to be moving sideways at speeds that would be more than 22 times the speed of sound here on the ground. So the goal of rockets is not to reach a specific altitude. The goal is to speed up to be going extremely fast horizontally. The problem is that if you tried to go at anything close to that speed near the ground, the air in the way would be a big problem. So rockets first go up to where there is less air and then turn sideways to do the actual task of speeding up a lot. If you did the same thing on a place without air, like our moon you could skip most of the going up part. You just need to b high enough not to run into any mountains and then could speed up sideways to orbital speeds."
],
"score": [
32,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[]
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|
[
"url"
] |
[
"url"
] |
|
lpsxot
|
If you have to sleep with a quilt or blanket over your head, is the level of oxygen that gets through the cloth safe?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goctpbt",
"gocty05"
],
"text": [
"Oxygen molecules are tiny, and a blanket is not an impenetrable airtight barrier. Plenty of air gets in, both by squeezing through the cloth and by leaking in around the edges.",
"It's largely dependent on how restrictive the blanket is at passing air through. Your body has a complex system for detecting excessive CO2 or insufficient O2 in the blood, so if the air you were breathing in was deficient, your respiratory drive would be noticeably greater and you would seek out fresh air almost instinctively. Overall, your greater risk lies in physically obstructing the airway with a heavy blanket, not the stale air pocket you're creating underneath it."
],
"score": [
5,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpt1vi
|
if water is transparent, why do some absorptive materials get darker when they're wet?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gocu3xr"
],
"text": [
"You are used to a certain level of reflectiveness ( brightness ) but water fills the gaps in the material and light hitting the water bends away from your eyes. Thus, the material reflects less light into your eyes and appears darker. URL_0"
],
"score": [
8
],
"text_urls": [
[
"https://www.abc.net.au/science/k2/homework/s95587.htm"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpux2x
|
will having been social distancing for year(s) affect our immunity to other diseases when things reopen?
|
I.e. like the cold, etc. that we normally would be exposed to during regular daily activities. I know cases of the flu have been reduced via lessened transmission, but will that potentially make next flu season worse? Will the immunity recover?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"god5k80",
"god5768"
],
"text": [
"No. Your body doesn't \"forget\" what it was previously immune to that easily. Your longest lived antibodies last for 10 years, or even longer. We will be out of social distancing before then. If we could get everyone the world over to social distance and take all the proper covid precautions, we could probably eliminate the common cold.",
"Your immune system does generally not get much worse when not being exposed to infections. So it is not expected to be a big issue that your immune system is out of shape. The biggest problem with living in isolation is that the immune system loses the ability to recognize the new diseases. The reason you need new flu shots every year is because there are constantly new mutations of the viruses that cause the flu so the vaccine you got last year does not apply to the viruses that spreads around this year. And after lockdown when viruses will be more free to spread around they will have the advantage of a lot of people not having been exposed to their last variant and therefore have a lower immune response to them. On the other hand because fewer people have gotten the flu this year there are fewer people where the flu might have created a mutation. So while there is going to be some differences in the flu viruses this year it is not going to be as much of a difference as you would expect in a normal year. But it will be exciting to see how this big scale experiment pans out for the flu viruses and we will probably learn a lot more important things about them that we would not have been able to learn without the lockdown."
],
"score": [
13,
7
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpvncm
|
why do we still pee when we are dehydrated?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"god8098",
"godsebh",
"godez8h"
],
"text": [
"yes, urinating loses a lot of water. But, our bodies do it because it is better than the alternative. Our kidneys filter a lot of bad, toxic stuff out of our blood, and urinating is then how we get all that bad stuff in our bodies. Yes losing water in a severe period of dehydration isnt great, but letting all of the stuff our kidneys filter out just sit in our bodies would also be bad, and it seems evolution has decided that losing a bit more water is worth getting extra bad stuff out.",
"Just to add - You don’t pee out the same amount of water if you are dehydrated. Your body tries to conserve as much water as possible while peeing out what needs to go to remain in balance (homeostasis). Your pee will thus become more concentrated as it tries to conserve water because it knows you need it.",
"You will pee less and less the more dehydrated you are, because yes your body starts trying to retain water"
],
"score": [
16,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpxfyq
|
why is alcohol classified as alcohol, and everything else as drugs?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"godh1lm",
"godls0o"
],
"text": [
"\"Drug\" is just a general term that covers alcohol and many other substances. \"Alcohol\" is a specific substance that has a certain effect on your body. People tend to call alcohol \"alcohol\" and drugs \"drugs\" to differentiate between a *legal* substance and an *illegal* one, but from a scientific perspective one *is* a form of the other.",
"It's just meaningless marketing/PR, much like \"natural\" or \"chemicals\". Alcohol is a drug, sugar is a drug, ibuprofen is a drug."
],
"score": [
20,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpxk68
|
Is your nationality based on where YOU were born, or is it based on where your PARENTS were born?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"godhm3f",
"godhv50",
"godjnpe"
],
"text": [
"Nationally is where you were born, basically what nation you belong to. Hints the word. Ethnicity and race are something else all together For instance my nationality is american, ethnicity is non-hispanic/european/asain/african, race is white/other. Race refers to physical traits and ethnicity is culture/ideology/religious affiliations.",
"Nationality, in legal sense, is the citizenship you have. In many cases it relates to the place you were born and grew up in.",
"This varies wildly from one country to another and can get very complicated. At the simpler end: USA: Born on US soil **or** to a US citizen off US soil and you’re a US citizen, with exceptions for weird diplomatic staff scenarios and other niche cases. At the more complex end: UK: Your right to British citizenship depends on where you were born, where your parents were born, when you were born, when your parents were born, what citizenship your parents hold, how they acquired their citizenship (birth, descent, naturalization, etc), when they acquired their citizenship, where they acquired citizenship, the controlling law at the time each of these events occurred, and more. Mere birth in the UK **or** birth to British citizens doesn’t convey British citizenship depending on the sum of other circumstances."
],
"score": [
5,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lpxpye
|
Is foam intrinsically important to the dish-cleaning process, or is this just a correlation?
|
I've noticed when cleaning dishes that when the cleaning solution is "sudsy," cleaning seems to happen more quickly (less scrubbing, etc.). Is this because: * The suds themselves help with cleaning * The suds don't help with cleaning but they indicate that the cleaning solution has a particular desirable property; * The suds don't help with cleaning and aren't related to any desirable property. A related question is: For any effective cleaning solution can one create a cleaning solution which is just as effective but has very little sudsiness?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"godkmrs",
"godky8w",
"godltia"
],
"text": [
"The perception is that more suds equals a better cleaning product. Have you ever heard of dish detergent being phosphate free? It's because some companies in the past added phosphates to make better bubbles and the bubbles are terrible for the environment.",
"Suds don’t help, they’re a product of the types of detergent used. There are more effective detergents that don’t suds up - if you have a dishwasher it probably uses some version of these. Manufacturers tried to market them for hand washing dishes a while back but everyone kept using way too much while still not believing their dishes to be clean, because they weren’t getting any suds from it.",
"For most of human history, suds were a byproduct of the property that made soap work well. Around WWII, households started using more detergents, which don't require or create suds, and they are only there so people trust it's working."
],
"score": [
9,
7,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lpy68d
|
Why does our power outlets have three different holes (live, neutral and ground)? Why can't there be just one?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"godmm6r",
"godokxa",
"godnm6h"
],
"text": [
"Electricity has to run through something to work. Like a river through a waterwheel. Live is where the electricity is coming from. The high point of the water. The neutral is where the electricity is going after it flows through your device. The low point of the water. Ground is a special place so that if the electricity escapes to somewhere it shouldn't, the power goes into the ground instead of more important things.",
"You always need two connections to make a circuit, otherwise electricity doesn't flow. The difference between live and neutral is that neutral is... neutral and live is... live. There are a few ways you can make a circuit with two connections, but the way we do it for wall power means that live is the one that pumps the electrons through, and neutral is a return path that doesn't really do anything by itself. Touching live will shock you, and touching neutral shouldn't, but it could if there's a wiring mistake so don't try it anyway. The third one - ground - is for everything that's **not** supposed to be part of a circuit, like the outside of a toaster, to stop it accidentally becoming part of a circuit, as a safety measure. If live touches ground the circuit breaker should shut off; it also prevents static electricity buildup.",
"You probably already know that electricity is conveyed by electrons. However electrons aren't *consumed* by the device like some kind of fuel, they are just methods of conveying a force. Imagine it sort of like if you were using hydraulics. You push fluid into one end of a pipe and since it cannot compress very well it is pushed out the other side with similar force. There doesn't need to be a high speed of flow within the pipe in order to get the push out the other side very quickly. Similarly electrons within the conductors move much slower than the electrical force is conveyed. Now imagine what the problem would be if you only had the one input wire. You push some electrons down the wire from the generator end, but without an outlet the charge of the wire and device at the end just increases. There is no significant **flow** which is where you are getting the force. The generator also has a problem in that it is losing electrons with no way to replace them; when the generator has a lack of electrons they will want to flow backwards to fill the void, moving the flow in the wrong direction! So you need both an input for the generator's electrons and an output for the device, something which is logical to link in the form of a neutral conductor. Now the system is like a chain drive on a bike, reusing the same chain (electrons) to convey a force. The ground comes in more like a safety outlet. The physical ground we stand on is potentially a massive sink for excess electrons, or even a source of needed electrons. It isn't infinite of course but the planet is huge enough that it is for all intents and purposes endless. Having a ground plug allows something like connecting a metal housing of a device to ground, so if a live wire comes into contact it doesn't conduct through a human touching it and instead will prefer to short to ground."
],
"score": [
17,
3,
3
],
"text_urls": [
[],
[],
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}
|
[
"url"
] |
[
"url"
] |
|
lpywl2
|
How were borders enforced or maintained in ancient times, when there were no walls, wires or security patrols?
|
How would a person from country A know that if they keep walking, after a point, they'll enter country B? I am thinking there must be some kind of a marker to let people know the limits of their home country?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gods5ce",
"godqt32"
],
"text": [
"Countries as we know them didn't really come into existence until the mid 1700's. Prior to that the world operated under a feudal system in which government was conducted by a hierarchy and people were really only loyal to the person above them. So for example, the people in Village A would think of themselves as Village A'ers and only be loyal to the lord of that village. The lord of that village would think of themselves as being a member of Region X, which was composed of villages A, B, and C. The lord of Village A would only be loyal to lord of Region X and so on until you reached whatever Empire was nominally in control of that area. The important thing to realize is that even though this village might be located in the Roman Empire, the villagers would not think of themselves as Roman. Only a tiny fraction of the people living in the Roman Empire actually thought of themselves as Roman, and those were mostly the people living in Rome or the Roman nobility that were governing the provinces. One result of this system was that the further you got from the capital, the less likely it was that the Imperial government was relevant to you. If you were living a remote province like Roman France or Persian Iraq then its unlikely that you would ever have any interaction with Imperial government. The only relevance that government might have for you was that if your lord's lord didn't pay their taxes then the Imperial government might send the army to pillage your farm. And the collection of taxes are ultimately how you would know where you were - as you were travelling around you would have to pass through different cities to buy food and other supplies. When a traveler entered a city they would usually be taxed and that's how you would know who controlled that city - you would just look at the flag being flown by whoever it was that was taxing you. But that was really the extent of the government's involvement in people's lives and if you were out in the countryside most people would only have a very vague idea of what empire they were living in. If you go foward in time to the middle ages, you still don't really have countries as much as you have language groups. Loyalty was to your lord but you could tell roughly where you were in the world by what language they were speaking. So if the people were speaking German you would know that you were in \"Germany\". That doesn't mean Germany was a country as we would think of it - most of the wars fought by German speaking people were against other German speaking people. Which isn't to say that German speaking people didn't view themselves as being closer to other German speaking people than they would, say, French speaking people - German speaking people definitely thought of themselves as being grouped together to some extent. But it would be more similar to how modern day people living in Africa might view other people living in Africa. That is to say, people in Africa view themselves as being more similar to one another than they do people from outside of Africa, but that doesn't necessarily mean much politically.",
"Cities certainly had walls and outer limits. The walls were not only there for protection, but tp force traders to pass through a certain point and thus pay the appropriate tax/duty for the product. There were some forms of border patrol, but this mostly applied to personal land. Those with large estates had wardens of sorts that would patrol the area to make sure people would not hunt off that land or take anything else that did not belong to them. Aside from that, there was not that much of a concern about country borders in the past. If a person happened to step over the line back in the day, it did not really matter. The concept of citizenship is fairly modern. A land owner did not really care if the farmhand was born there or somewhere else, they only cared if that person would work. It only became a concern once they started to encroach on others, or if they started a larger scale operation on that land. In either of those cases, someone would eventually find out and then owners of the land could react appropriately."
],
"score": [
15,
5
],
"text_urls": [
[],
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}
|
[
"url"
] |
[
"url"
] |
lpyzni
|
Why does computers have to work in binary?
|
Instead of only 1 and 0, what if there's an inbetween? So that 1 bit can have 3 possible state instead of just 2? Is binary the only way a computer could work or is binary the most efficient way of doing things? Basically my question is, if there is an alien race out there with advanced supercomputer, would they still use binary or is there other way of doing things that our current understanding in technology simply haven't reached yet?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goduk5k",
"godudu5",
"godxym4",
"godx7i9",
"goduimx"
],
"text": [
"They don't have to, it's just the easiest way to do it. We do know how to make a computer that uses base3 or higher, but it's just needlessly complicated for not much gain. \"No voltage\" and \"Yes voltage\" is very easy to distinguish, once you introduce in-between levels there is much more need for precision in order to not get confused. Heck, *before* we had digital (binary) computers, there were analog computers! And analog = infinitely many different levels.",
"It's much easier to design circuits that are either hard on or hard off. Circuits that work smoothly over a range of voltages have to be carefully tuned and need fine tolerances. The small gain is not worth the huge increase in complexity. The exception is flash memory which have cells that use 8, 16, or even 32 different voltage levels. They require analog electronics between the cells and the components (ADCs and DACs) that convert to and from binary. No calculations are done with the many-level signals, only storage and retrieval.",
"You know how ships used to communicate using lights? They'd have a big light with shutters in front of it and they would open and close the shutters, using Morse code to talk to each other. They only had two states to work with: open and closed, or 'on' and 'off'. If they had added a third 'half-open' state, they could have used a more efficient encoding system than Morse, and they could have transmitted the same number of words using fewer signals. So why didn't they add a third 'half-open' state? It's very easy to distinguish between 'on' and 'off', even in bad conditions (bad weather, long distance). Either there's light or there isn't. If you add a third half-open or half brightness state, that becomes a lot trickier and you may get it wrong sometimes when you're trying to read the signals from another ship. There are going to be cases where you're not exactly sure whether the light was at full brightness or half brightness. Computers using a third state would have similar problems, especially at very high speeds. Keep in mind that we increase the working speed of computers to the point where they juuust about work. If you use signals that are less distinct than just on or off, you'd have to give them more time to properly read it. On/off are easy to distinguish, even if the signal isn't 100% clean. There's also the fact that on/off signals are easier to produce with the electronics that we have developed. If you were tasked with operating the shutters of one of those signal lamps on ships and you only had to do either on or off, you could operate them very quickly. If sometimes you had to stop midway to do 'half-open', you'd have to go slower and be more careful in order not to open them too far. Electronics are sort of similar, in that switching something hard off or hard on is easier to do than nailing an in-between state without under- or overshooting.",
"Computers don't really think in 1 and 0. They think in on and off. We just use 1 and 0 to represent them and do higher level math about them, but really it's on and off. The brain of a computer has a few basic logic operations. AND, OR, XOR, and NOT (then also NAND, NOR, and XNOR as NOT'ed versions of the first 3 that don't require an extra step). That is *all* a computer does. They take 1 or 2 true/false inputs, and create a single true/false output. Do this several billion times a second in the right structure and you can make a computer. So no, there isn't really an in between, because those basic operations don't have in betweens.",
"Every once and a while, a ternary computer comes up, though we haven't really seen one in production since the Russians in the 1980s. Instead of 0 and 1, they had -1, 0, and 1. The Intel x87 math co-processor actually had 4 states in its memory. The x87 instruction set is baked into your modern Intel processor, though, there are more modern math instructions available to modern software. In the end, these computers are all Turing Complete, and equivalent to each other. There's nothing any one of these machines can do that the other can't. Some of these architectures make certain problems easier, but also some harder. The performance gap between them have long since closed. Instead, what you're seeing is a resurgence in analog computing. You can multiply or divide, for example, a lot faster in analog than in digital logic. Precision suffers, but it's cheaper to get an approximate answer to start, and then march that approximation toward the desired level of precision with a Monte Carlo simulation than it is to compute the desired level of precision from scratch. EDIT: We also commonly see multi-state data in wire signaling and modulation, such as PSK, which is used in WiFi and RFID."
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13,
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[
"url"
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lpzdih
|
how do ants in ant colony know what’s their role? Are they trained for these roles (soldiers, farmers, etc.)? Are there ants that go through “career changes” and switch roles?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"godtuwa",
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"gofll1x",
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"text": [
"Some roles are just based on body type. A soldier is never going to become a queen. But others do actually change roles. Ants communicate through chemicals and if an ant in one role goes awhile and doesn’t encounter much of a chemical associated with a role, it can change to that role. So, imagine half the foragers get eaten by an anteater. Other ants slowly notice they’re not encountering enough forager chemicals and might switch roles. That eventually restores the balance.",
"Ants operate with swarm logic. This means that every ant does what it thinks makes sense to do. So if an ant thinks the best use of its time is to move larva to another section of the nest, it will just start picking them up and leaving a pheromone trail telling other ants what she’s doing. If another ant decides that’s a good idea she may also start carrying larva, or if she thinks it’s a bad idea she may bring the larva back. This also applies to the roles they take on, with the exception that some species have body types, which have more specific roles like soldier or guard. Lots of ants can freely choose to spend their time digging, scavenging, protecting the queen, tending to larva, or garbage disposal. Every ant decides what seems important and the colony just works.",
"Ant behavior is a kind of phenomena we call *emergence* or *self-organization*. A simple example of self-organization is how a school of fish moves. They all seem to move in coordination, without seeming to take orders from any one fish. There's a simple set of \"rules\" that each fish follows, though: stay close to the fish next to it, but not *too* close, and swim away from predators. These simple rules, when combined with a group, cause the school of fish to act as one organism. The rules are just instincts which every individual is born with. Ants work similarly. They have a simple set of \"rules\" that are instincts for them. They might have a rule that they desire to make columns from dirt, but if there are too many ants already creating columns, then they'll go outside to collect food. These rules get a bit more complicated in reality, but they're still pretty simple for each individual. Besides their instincts, there *are* certain types of ants, such as drones or workers. They each are born with their own instinct to carry out different \"rules\" for different circumstances. Drones never become workers and workers never become drones. And then there is the queen. The queen ant mostly just lays eggs, and the workers take care of her. She doesn't give orders or anything. There are also pheromones that ants release which cause other ants around them to stop doing what they're doing and take collective action. For instance, if an ant encounters a foreign ant from a different colony, it will release a pheromone that tells nearby ants to come and defend their colony.",
"It's easiest to think about ants as finite state machines (FSM). An FSM is a model that defines a number of stages. An ant FSM for example might define the states: * Eat * Forage randomly * Bring food to the colony * Attack! * And so on * Run away / escape * Many other states To determine what an FSM or ant will do at any given time, it'll constantly evaluate all external stimuli to attach importance to each state before selecting one for its current behaviour. The amazing thing about eusocial insects like ants is that each of them is like a little robot. They have exactly the same states and responses. But those responses work in such a way that many ants together seemingly cooperate in an intelligent manner, even though they don't really discuss anything or consciously cooperate. For example: * Ant A is randomly foraging for food when it finds a discarded cookie. This triggers a state change from foraging to bringing food from the food source to the colony. * Ant A takes a crumb, heads back to the colony and lays down a scent trail without thinking about it. * Ant B is foraging randomly when it finds this scent trail. This triggers a decision moment where it weighs the importance of random foraging against the importance of following the scent trail. It's a weak scent trail so let's say it's a 50/50 decision but Ant B's state changes to following the trail. * Ant B finds the food and this triggers a state change to grabbing a crumb, heading home and laying down a scent trail. Exactly the same behaviour as Ant A but without realising it Ant B reinforces the scent trail. * When Ant C finds the scent trail while foraging randomly, it behaves exactly the same as Ant B. It weighs the importance of foraging randomly against the importance of following the scent trail. But the trail is reinforced by Ant B and Ant C is slightly more likely to follow the trail. It does and Ant C grabs some food, heads home and reinforces the trail. There is zero discussion between ants and each of these ants behaves exactly the same way, like a little robot. But this way a large food source will attract more and more ants who each reinforce the scent trail attracting even more ants. Until the food is gone. A few ants will still follow the scent trail but find no food and as a result, don't head home while reinforcing the trail. The trail will quickly dissipate and no more ants will be attracted. A small food source will attract fewer ants because there are fewer opportunities for reinforcing the scent trail before the food is gone. Logistically speaking, any food source will attract an appropriate number of ants to efficiently transport it. Even though no single ant knows what its job is, has a big picture view of what's happening or is directly communicating to its fellow ants. They all just behave exactly the same and the end result is seemingly intelligent. Ants do have roles within their society but these roles are the result of different ants placing different emphasis on their canned responses. For example, in many colonies, only the oldest ants go outside the colony to forage. After all, these are the ants that are already closest to the end of their lifespan and as a result, the most disposable for risking in the dangerous outside world. Young and old ants have different jobs. But nobody assigned them these jobs. It's just that a younger ant is more likely to respond place more importance on jobs (or states if you will) inside the colony like digging tunnels or feeding larvae while old ants are more likely to emphasize jobs outside the colony. Along the same lines, nobody tells ants to go dig a tunnel or make a room. Environmental factors like population density (based on pheromone density) and air quality will encourage individual ants to go dig. Some ant species do grow physically divergent colony members. For example ant species that have both workers and soldiers (and sometimes many other classes). Nobody tells a soldier to go fight. Soldiers just place more emphasis on defensive or offensive tasks when weighing their states. Individual ants don't really know anything. They don't reason, they don't think, they don't maintain dialogues with other ants. They just evolved behaviour that works on an individual level but also achieves very efficient results when all ants behave the same way.",
"I don't know about ants but I know a bit about honey bees if that will do? Please delete if not. Bees have different roles as they mature. Freshly hatched bees clean up, moving debris out of the hive and keeping the combs that contain larvae clean. Then they become nurse bees, nurturing and feeding the larvae. Next they move on to processing incoming nectar, making honey and capping the honey combs. Some of these bees also tend to the Queen. It's only the older workers that leave the hive and forage. When I say old, they live about four to six weeks."
],
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39,
12,
10,
10,
6
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[
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[
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|
lq0628
|
Why does hollow chocolate taste different than regular chocolate?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goejneh"
],
"text": [
"Surprisingly enough, this topic was briefely mentioned in a physical chemistry lecture I attended today on crystallography. To cut a long story short, it'll most likely be due to hollow chocolate having a larger surface area per unit volume, meaning that the chocolate will melt in your mouth/your tongue at a faster rate than solid chocolate. This'll give the effect of different tastes, as you're experiencing different amounts of flavour in your mouth between the two. Edit: This surface area difference will also change how the chocolate smells, which will enhance it's taste in hollow chocolate."
],
"score": [
5
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
|
lq0q7h
|
The differences between the DOW, NASDAQ, and S & P500 and how they differ from regular company stocks
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"godyodt",
"godzonc"
],
"text": [
"The three indexes you listed aren't equities or finds, but rather an index designed to indicates the performance of a group of companies over time.",
"The Dow and S & P500 are stock market indices. Basically, they're a weighted average of the prices of stock from various companies. In the case of the Dow, it's 30 of the largest in the country from various industries. For the S & P 500 it's the largest 500 companies by market capitalization. There's a little bit of fanciness that goes into computing the average that attempts to deal with changes in the number of shares a company issued (which would impact price per share but not really impact the total value of the firm) but, on the whole, they're really just averages. The Nasdaq is actually a separate stock exchange from the New York Stock Exchange (where most big firms are listed). Lots of tech firms are listed on the Nasdaq. When people say how the Nasdaq is doing, they're usually talking about an index similar to the Dow or S & P 500, but comprised of the largest firms listed on the Nasdaq. Again, the overall principle is the same for all of these. They're just fancy averages of the price of shares of particular groups of firms."
],
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4,
3
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|
[
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[
"url"
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|
lq0tjv
|
How does a CRT fire electrons at a screen with such accuracy?
|
So, I've been reading up on how a TV works - specifically, the older style ones. I've learned that they have a gun that fires electrons at the screen which 'lights up' the pixels because they are made of special materials. The thing that amazes me is how the electron gun can fire the electrons with such precision. The pixels are so close together. Does the gun physically move or is it done with magnets or something and if it is done with magnets how do they control the current precisely enough to fire each electron at the exact right place?
|
Technology
|
explainlikeimfive
|
{
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"goe48hr"
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"text": [
"CRT TV electron sources are stationary. The electron beam is deflected horizontally and vertically by specially-shaped electromagnet coils, controlled by a main circuit. That's why wide CRT screens were very deep and needed a deep shelf. The intensity of the electron beam at each part of the screen is based on the received analog picture signal. In the case of color CRT screens, there are 3 separate amplified signals, to control 3 separate electron beams, for red green and blue. These 3 color signals are generated in real-time, inside the TV's circuitry, based on clever analog processing of the (one) incoming received signal. The secret sauce is a precision manufactured grid screen with tiny holes. This grid sits between the electron source and the colored phosphor pixels that're on the backside of the glass TV screen. Given the manufactured angles and positions, each hole in the precision grid allows one of the 3 electron beams to pass to illuminate only the red phosphors, one electron beam to only illuminate the green phosphors, and one for only blue phosphors. Very accurate angles and positions of the screen, means the electron beam intensity does *not* need to change improbably fast, precisely, or be super focused. That allowed home VCRs to record TV broadcasts, albeit with fuzzier horizontal picture resolution and worse color resolution. Still, analog data allowed quite a lot of information, so it took decades for digital computer technology to become fast enough to \"catch up\" to allow comparable frame rates and image resolution."
],
"score": [
10
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|
[
"url"
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[
"url"
] |
lq28fv
|
apart from affecting the density of matter, does gravity affect sound?
|
Are sound waves pulled down? Also as a bonus question, does gravity affect anything other that matter?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"goe8twp",
"gof5ne9",
"goea7mh"
],
"text": [
"Gravity affects anything with energy, including matter with mass (mass is a form of energy) but also light/electromagnetic waves/photons, which don't have rest mass but do have energy and momentum. This is why light from distant galaxies can be bent and distorted during its travel from there to here -- it is being affected by the warped spacetime aka gravity. I don't believe gravity directly affects sound waves. Like you said, it does affect the medium in which they travel, though, so for example a change in gravity can cause a change in the density of air and alter the properties of sound waves. It won't make them fall down towards the source of gravity, though. EDIT: According to the article shared by another commenter, this might be wrong, and sound waves may actually possess *negative* mass. Interesting!",
"Interesting question. I would expect that since gravity is the curvature of spacetime, that sound waves traveling through spacetime would have to follow the curve of space just like everything else.",
"sound is just a specific way matter moves. if the matter is pulled down, the sound being carried by the matter is too. if the source of the sound is pulled down, the sound it emits gets distorted similar to how the sound of a car distorts when it drives past you and gravity affects light. when light passes close to a black hole or very large star, astronomers notice it bend through what they call a gravity lens"
],
"score": [
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5,
5
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|
[
"url"
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[
"url"
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lq2k5q
|
Why do liquids evaporate below their boiling temperature.
|
Water's boiling temperature is 100C or 212F, when you spill some on concrete or leave a cup of water outside, it disappears without it reaching 100C even if it is in the shade. The water from the ocean also evaporates, but it is not boiling. This happens with other liquids to such as isopropyl alcohol, or gasoline. How does this happen?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"goe9mca",
"goe9b19"
],
"text": [
"Because \"temperature\" is a property that only exists in collections of particles, each particle itself only has it's own energy. So, all a particle on the surface needs, in order to evaporate, is to get hit from behind with enough force to overcome the bonding forces between it and the other particles.",
"Boiling temperature is just the temperature at which material no longer exists in liquid form. All liquids evaporate at most temperature/pressure combinations - all it takes is enough energy to excite a molecule on the boundary layer between the liquid and its gas environment."
],
"score": [
12,
4
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
lq2yje
|
What’s the difference between depersonalization/derealization and Cotard’s delusion?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"goekqt9"
],
"text": [
"Cotard's delusion is specifically about feeling like you're dead. As in, a corpse. Depersonalisation isn't that, it's about not feeling real. I had it, or something like it, briefly this one time. It's not really a delusion--I didn't believe that I wasn't real. It was just a feeling, not something I was convinced of. It's hard to explain it to someone who hasn't experienced it, but it's sort of like feeling detached from your own consciousness. It feels like you're merely controlling yourself from outside, like you're a character in a first person game, rather than actually being in your own head. I'm not entirely clear on the differences between derealisation and depersonalisation, so if anyone with more knowledge wants to correct me, feel free to do so. In any case, Cotard's delusion is a long term belief, rather than a temporary feeling, and it's also classified as a distinct disorder, whereas depersonalisation/derealisation are symptoms of multiple different issues."
],
"score": [
8
],
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|
[
"url"
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[
"url"
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|
lq37ug
|
I understand roughly how a computer works (large amounts of logic gates working together to solve the problems they are given) but how does the brain do this? For example, how does the brain solve a simple math problem?
|
Edit: Didn’t know I was allowed text👇 I find it hard to understand that a highly compact organic structure can often out perform large and complex computers, now obviously with growing tech that is changing, but what aspect of the human brain gives it such capabilities? A computer is given instructions and a vast quantity of logic gates work together using a binary code to create an answer. What is the brain’s equivalence of logic gates and how do they work?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goeghdi",
"goee91d",
"goedwxe"
],
"text": [
"Roger Penrose argues that consciousness is NOT computational. It’s a fascinating theory called ORCH-OR. I’m no expert so please look it up, but effectively he theorised that consciousness is derived from quantum mechanics occurring in things called Microtubules which are smaller than neurons. He says that many actions are computational but consciousness itself requires different physics.",
"The brain is made of billions of cells, called neurons. Neurons respond to stimulation and in turn stimulate other cells. Some neurons are connected to your senses, like hearing and seeing. These are the input neurons. Other neurons are connected to your muscles and control movement. These are output neurons. Many, many, more neurons are divided across layers in between the two. There are intermediary neurons. When your senses are triggered, they stimulate input neurons. This creates a domino effect, through the layers of neurons, stimulating a specific pattern. This pattern causes a specific output. As pathways are stimulated over and over, they are strengthened, making them easier to trigger again. If a pathway creates an invalid or undesirable outcome, it doesn't get repeated, and so it doesn't gain strength. These reinforced pathways are your memory. They are how you think and how you respond to stimuli. It is how the brain is always changing and always learning. Its truly amazing stuff.",
"The answer is: we don't know. The brain/mind interaction is completely unknown at this point. We know some things, like that in blind people, math \" occurs\" in the same area that non-blind people use to see things. We can pinpoint specific areas of the brain that are more active during the processing of math. But we just don't know how it works."
],
"score": [
5,
5,
4
],
"text_urls": [
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|
[
"url"
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[
"url"
] |
lq3j3s
|
Why is the medical treatment for people with ADHD/ADD often a stimulant?
|
So, being a young adult with a suspicion of having some sort of the aforementioned, I've read that the treatment involves medicine of the stimulant sort. Wouldn't that make the underlying anxiety and restlessness worse? Or is it some sort of "shove" to artificial motivation, like making an old engine start up? Thanks in advance.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goegk53",
"goegi51",
"goexygw"
],
"text": [
"I have 4 kids, 3 of them are Attention Deficit. This is my understanding of how it works. The ADD mind can't easily focus on one thing. When the person tries to \"think hard\" about something, brain activity actually **drops**, to the point that some of my kids have complaineed about feeling sleepy when they try to do math. Some ADD people will even \"self-medicate\" by arguing pretty much constantly, because that stimulation electrifies the brain, and they can think clearly. By providing a stimulant in a controlled, time-released dose, thinking clearly and remaining calm(er) is actually easier, because the stimulation from the meds allows them to focus on things like school work.",
"The idea is that ADHD people actually have less activity in the part of the brain that you use to regulate yourself. Stimulants help get this part of your brain working so that people with ADHD can focus and self regulate the way most people can on a normal basis.",
"Different parts of your brain communicate via a chemical called dopamine. Dopamine basically tells some parts of your brain that whatever you're doing right now is very important. If you have ADHD, some parts of your brain receive too little dopamine and they can't communicate with each other properly. Let's say you want to do homework. The network that's responsible for your consciousness is aware of how important this is, but the part of your brain that is actually used to focus on that doesn't receive the signal. That means you consciously want to focus but you physically can't. Stimulants generally increase the concentration of dopamine. If you didn't have enough dopamine before, now you have, and you can normally focus on the work you want to do. If you however do not have ADHD, stimulants make you have too much dopamine. With too much dopamine released in your brain, suddenly everything becomes extremely important. You are extremely awake, you don't think about eating or sleeping anymore because other things are more important, and eventually you cannot focus anymore because everything around you becomes equally important. That's where the unexpected reaction comes from. Stimulants actually always work the same, it's just that some people don't really need them so they would take too much and automatically have non-lethal overdose side effects, if you will. Please note that this is a huge oversimplification, as dopamine does a lot more than that, and another chemical called norepinephrine or noradrenaline usually also plays a role in stimulants, but that would be way too much for an ELI5 :)"
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12,
10,
4
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|
[
"url"
] |
[
"url"
] |
lq3p1i
|
Why do we stick out our tongue sometimes when we focus?
|
I was just focusing on homework and I realized that I was sticking my tongue out a little bit. Does anyone know why we do this?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goehkzg"
],
"text": [
"It’s a way of breaking the means of communication between tongue/speech/word forming and the brain. When this is done, the brain can temporarily shut down parts of the communication systems, freeing up more processing power for the task you’re concentrating on (because it knows there will be no speech action going on as long as the tongue is isolated in that way)."
],
"score": [
11
],
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|
[
"url"
] |
[
"url"
] |
lq3w9u
|
What's the difference between price gouging (like in a hurricane for example) and whatever Texas power companies are doing?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"goegpth"
],
"text": [
"There is no regulation against utility providers adjusting variable rates as already agreed upon in an agreement between the provider and customer."
],
"score": [
3
],
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|
[
"url"
] |
[
"url"
] |
|
lq4u60
|
Why can we not access all of our memories?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"goemfci"
],
"text": [
"If you have a library of 5 books, it may be small, but you know where those books are any time you need them. If you have a library of 1 billion books, good luck finding the one you need. It'll take a lot of time. That's basically it. While it'd be nice to have infinite memory, 1) where would we put it? 2) it'd take forever to find the right ones when we need them. The brain doesn't have infinite storage and it doesn't work infinitely fast. So it can't do it."
],
"score": [
4
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
|
lq5nm6
|
Stoichiometry Dimensional Analysis
|
Help! I'm having a really hard time in Chemistry right now and my teacher is going way too fast. I'm unable to retain nearly all of the rules for Stoichiometry dimensional analysis. Is there an easier way to remember this? Thank you!
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"goey9tq"
],
"text": [
"Stoichiometry is making sure that each reaction is balanced on both sides. So if you were burning natural gas (methane, CH*_4_*) with oxygen (O*_2_*), you would need to burn one molecule of methane with two molecules of oxygen: CH*_4_* + 2O*_2_* - > CO*_2_* + 2H*_2_*O You must have the same number of atoms of each element coming into the reaction as leaving the reaction. Dimensional analysis is a way of looking at the units of a reaction/process to make sure that you are properly converting them around. If 1000 g is equal to 1 kg, then you can write a fraction using the two units: (1 kg)/(1000 g), or (1000 g)/(1 kg). Then you can multiply any number by this fraction in order to convert the units and account for the conversion factor. The fraction itself doesn't chance the value of the original number, since the numerator and denominator are equal: X/X = 1, and you can multiply anything by 1 without changing it. So if you were trying to find the weight in pounds of 330 mL of gasoline, you could multiply the volume (330 mL) by the density of gasoline (0.755 g)/(1 mL) by the conversion factor between pounds and grams (1 lb)/(453.59 g). If you multiply/divide that all out correctly, you get 330 \\* 0.755 / 453.59 = 0.549 lb, about half a pound of gasoline."
],
"score": [
3
],
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|
[
"url"
] |
[
"url"
] |
lq5ww7
|
Kubernetes
|
Please explain like I am 5.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"goet92h"
],
"text": [
"Have you looked at The illustrated Children’s Guide to Kubernetes?"
],
"score": [
3
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[
"url"
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[
"url"
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lq654f
|
The Monty Hall math problem
|
I was watching Brooklyn 99 Season 4 Episode 8 around the 5 minute mark The problem goes "There are 3 doors behind one of which is a car. You pick a door and the host, who knows where the car is, opens a different door showing nothing behind it. He asks if you want to change your answer. Apparently the math dictates that you have better chances if you change your decision. Why? 2 doors 50/50 chance, no? One character (Kevin) says it's 2/3 if you switch 1/3 if you don't. What? How? Please help.
|
Mathematics
|
explainlikeimfive
|
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"text": [
"Say there are three doors, A, B, C. One of them has the prize, and you pick one, hoping you picked the one with the prize. Simple enough. To make it even more simple, we can say that door A is the one with the prize in it. Now the game starts. You pick a door at random. 1/3 chance of A, 1/3 of B, 1/3 of C, right? So at this first pick, you have a 1/3 chance of picking correctly (door A). Now Monty Hall opens one of the other doors. The door he opens **won't** have the prize behind it, or the game would be over. If you picked A, he could reveal either B or C. Switching now would lose you the prize. If you picked B, he would reveal C. Switching now (to door A) would win you the prize. If you picked C, he would reveal B. Switching now (to door A) would win you the prize. So after the reveal, that single \"50/50\" choice to switch doors is actually based on the original 1/3 choice. Switching afterwards will get you the prize 2/3 of the time, because you would've only picked correctly 1/3 of the time in the first pick.",
"The host never reveals a door which has the prize behind it. You already know from the start that two doors don’t have prizes, so when you pick one you already know at least one of the doors you don’t pick has no prize. Which has a better chance of having the prize, 1 door or 2 doors? Obviously 2 doors. One of those 2 doors is always going to not have the prize but the host eliminated it by showing you. So by switching you in essence pick the 2 doors option.",
"The key thing is that the host knows which door has the car. Imagine a more extreme case. There are 100 doors with a car behind 1 of them. You pick door 7. The host reveals the goat behind every door except door 7 and door 38. Suddenly, door 38 looks suspiciously appealing... You had a 1% chance of getting the right door. This means there's a 99% chance that door 38 is the right one. Again, the trick is that the host knows the right door. If the host didn't, then most of the time the host would accidentally reveal where the car was. It's the *host's* knowledge that changes the odds.",
"Caveat to what everyone else is saying: if the problem is not explained very precisely, the true answer is undetermined as there is not enough information to compute. In particular, it is important that 1. the host knows where the car is, and 2. the host deliberately chooses never to reveal the car Saying that the host knows where the car is and happened to open nothing in this particular instance is not sufficient information to create the 2/3, 1/3 solution. It is important that the host deliberately avoids the prize, as that is what causes the door he didn't choose to become special. He has special knowledge, and you can gain partial knowledge from observing his behavior if his behavior depends on his knowledge. If, instead, the host opens doors randomly and just happened to open nothing this time, then we are not in the true Monty Hall problem, but the \"Monty Fall\" variant, in which the answer is 1/2, 1/2 as people intuitively suspect. In a lot of cases, the problem is difficult not because people being given the problem are bad at math, but because the presenters are, and provide an ambiguous scenario which could either be the Monty Hall problem or the Monty Fall problem, and people assume it's the Monty Fall problem since that's a reasonable assumption someone would make if not given information that rules it out.",
"The explanation that clicked for me was to think of them as two groups. Group A is the door you choose. Group B is the other two. After your first choice, there's a 33% chance it's in A and a 66% chance it's in B. Now what if they said, \"Do you want to stick with A, or do you want to switch to B?\" Of course you'd switch, because group B has two chances. When they remove one of the bad ones, there's still a 66% chance it's in group B. By letting you switch after getting rid of one of the losers, they're still giving you *all* of Group B. It's kind of like they let you pick two doors instead of one.",
"The Monty Hall problems come down to this, is it better to choose one door, or two doors? If you decide to stay with your original pick, you are basically saying that you want to keep your one door instead of the two other ones. When you change doors, you are picking both the other ones. A lot of people get stumped by the door reveal, but that door reveal is actually 100% inconsequential. The prize can only be behind a single door, which means that most doors will be empty. In the two doors that you did not pick, one door *must* be empty. That does not improve or worsen your odds in any way, because it is expected that the door will be empty. Furthermore, the host knows not to open a door that has the prize, so the door will be empty. Since this step is inconsequential, you can skip it. So, Monty says pick a single door. Then once you pick a single door, he skip opening an empty door and says \"okay, do you want to keep your single door, or switch to the other two doors?\" Which do you choose, one door or two? Another way to help this problem is add the amount of doors. Let's say that there was 100 doors, and you have to pick one. You pick one, and then Monty says \"do you want to switch to the other 99.\" Keep in mind that with those 99 doors, at least 98 of them will be empty. If you see a bunch of empty doors, that should not be a surprise. Which do you chose?",
"The key detail: the host can't reveal the prize door, and the outcomes of the choices don't ever change. By being forced to only reveal a non-prize door, the host is disclosing information about the other choices.",
"One way to solve it is to list all the scenarios: Assume car is behind door #1. Car | You choose | Monty opens | You switch | Don't switch ---------|----------|----------|----------|---------- 1 | 1 | either 2 or 3 | lose | win 1 | 2 | 3 | win | lose 1 | 3 | 2 | win | lose Doors 2 and 3 are the same."
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"url"
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lq754g
|
- What are the major differences between the different factions of Libertarianism? Which fiction do most Westerners refer to when they use the blanket term "Libertarian?"
|
Other
|
explainlikeimfive
|
{
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"gof34mf"
],
"text": [
"There are many kinds of libertarian. There are, in fact dozens of different factions and fictions and versions. Some are loud. Some are quiet. Some are aggressive and some are just nutbars crazy. For simplicity's sake, I've complied the 24 most common versions of Libertarian. [Here]( URL_0 )"
],
"score": [
8
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[
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]
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|
[
"url"
] |
[
"url"
] |
|
lq7fqf
|
How do people who gather statistics report the number of people who don't do a certain thing?
|
I wasn't sure how to word the title but I was just doing some research on sexual harassment and I came across "54% of rape is not reported." How would they know that if no one said anything? And if they meant someone came forward years later rather than instantly, wouldn't that still count as reported?
|
Mathematics
|
explainlikeimfive
|
{
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"gof2krj",
"gof524x"
],
"text": [
"You surely a large group of people and ask how many have been raped, then you also ask whether or not they reported it. So instead of looking at cases, you look at the incidents.",
"One way — not for rape — that is used is to give all respondents a coin. Tell them to flip it and not let you see the results. If it comes up heads, they say they did whatever the bad thing is. If it comes up tails, they tell the truth. Then you compare how many above 50% said they did it"
],
"score": [
5,
3
],
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|
[
"url"
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[
"url"
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lq7rtv
|
How do we know how long some things take to decompose if it's claimed they take longer than what they've existed for? (Example, plastic bags)
|
Chemistry
|
explainlikeimfive
|
{
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],
"text": [
"You accelerate the breakdown. A typical method is to use temperature, although it's not the only way. You take a substance and figure out how to quantify its breakdown. Then you take multiple samples and expose them to multiple high temperatures (usually at least 3) and measure their breakdown vs time. You usually do one set of samples at temperature T1, another separate set of samples at T2, etc. After you've done this and plotted the results, you can calculate how much breakdown occurs vs. time and temperature. There are some pitfalls you have to avoid, but if you are smart about it you can figure out the degradation rate at any reasonable temperature and time frame. This same basic technique works in a variety of situations, not just plastic bags. For example, it's how engineers figure out how long light bulbs are going to last."
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13
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"url"
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[
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|
lq80z9
|
when you die from blood loss, do you feel like you are dying from not being able to breathe? Because your lungs are breathing but you're not getting oxygen where it needs to go, would it feel something like suffocating?
|
Biology
|
explainlikeimfive
|
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"text": [
"800-273-8255 Just going to put this suicide prevention hotline number here juuuuuuusssstttt in case :) Probably just a curious mind wondering, but my mom brain can’t help itself.",
"I nearly passed out after donating blood because I was dehydrated. My ears started to ring, my vision got blurry/delayed/streaky like I was drunk, my muscles got delayed and less coordinated, and my face felt hot. Sorta felt nauseous. Leaning back with a cold towel on my forehead and a big drink of water and sugar/salt helped. It was definitely disturbing and I was glad to have nurses handy to help me get comfortable and get my blood pressure up again.",
"I've actually been through this, and you would be unconscious before you died. However, the period up until you pass out - though short - is utterly terrifying.",
"The process of exsanguination (death from loss of blood) causes the heart rate to drastically increase in order to effectively pump what blood you have all over the body and most importantly to the brain. At some point, the amount of blood making it to the brain is not enough and you pass out. During this whole process, you become cold and dizzy because not enough blood is circulating around the body. You can feel extremely heavy/weak and, indeed, get short of breath with little feats of exertion.",
"I presume that the sensation of breathing just arises from lungs inhaling *something*, not necessarily air. Think about it - you could breathe an odorless, toxic fume like carbon monoxide, and you wouldn't be able to tell the difference. Until you fall unconscious and die, that is.",
"The body feels suffocation from CO2 buildup rather than a lack of oxygen, so dying from blood loss wouldn't cause that feeling because it's not reacting to a lack of oxygen. My understanding (as not a medical professional) is blood loss is relatively painless on its own, it makes you sleepy until you just fall asleep and die (if not saved).",
"Two possibilities, inability to maintain blood pressure or hypovolemic shock. It would depend on the rate of blood loss. High rate would likely lower blood pressure (think not enough water in the hose) to the point you could have an arrhythmia (heart malfunction) and brain death in 6 minutes due to no oxygen being pumped to the brain. Lower rate loss leads to Hypovolemic shock Hypo=low, volemic=volume, shock=the inability of blood to perfuse muscle. This means all those important organs (heart, liver) can't get blood which in turn can't get oxygen or expel CO2.",
"I had a bleeding ulcer, didn't recognize the signs, went up a flight of stairs turned the corner though I vividly remember calling out my sister's name with that oh s*** sound to it. While laying there on the floor I regained consciousness, but as soon as I sat up I started to lose consciousness again because of the lack of blood flowing through. Beyond the sudden feeling of going dark, I don't remember any other ill feelings. I certainly didn't feel the first pass out, when my head hit an aluminum dog bowl and made a dent in it like you wouldn't believe. A very interesting experience. In relation to OP's question, it's likely if you're going out to do the blood loss that you don't recognize it or don't have those kinds of feelings because of the blood loss"
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|
lq82k6
|
how does snow cause potholes on the road?
|
I've always been pretty confused how there's always massive pot holes in the road once a massive snowstorm rolls through our valley.
|
Chemistry
|
explainlikeimfive
|
{
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"gof6ni1",
"gof5yln"
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"text": [
"Its a combination of two things that come with snow. Freezing temperatures, and snow removal. When you have a road there are always going to be at least small holes/cracks in the pavement. these holes/cracks let water in/underneath the pavement. During warm months, this doesn't really matter and the water eventually drains away. But when there's water in/under the pavement and freezing temps come along, that water freezes. And when that water freezes, it expands. It expands enough that it can actually break up concrete, especially if there are already small cracks/holes to make bigger. Since the water is under these pieces of pavement, it also can push these cracked pieces of pavement up, which leads to the next cause. Snow removal. Snow plows do their best to not tear up the road, but at the same time they're trying to get as much snow off of the road as possible, so that big metal plow is ideally just skimming the top of the pavement. But say it goes over a cracked up section where the pavement has been pushed up 1/4 of an inch by water freezing beneath it. That big metal plow in front of a 15+ ton vehicle is just going to tear up that already broken up pavement and toss it to the side just like it would snow. So you get this 1 2 punch of the freezing temperatures breaking up the pavement, and then large vehicles moving that broken up pavement around.",
"Snow melts into water, then freezes causing pressure on the surrounding material that loosens it. Then next time there's more space for more liquid to get in, and when it freezes again it expands and thus expands the crack/hole more. It's the cycle repeated over time that breaks shit up."
],
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8,
4
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[
"url"
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[
"url"
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lq8q79
|
Why does meat get tougher after cooking, but tender after cooking for a very long time (or under pressure)?
|
Biology
|
explainlikeimfive
|
{
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"gofbeul"
],
"text": [
"**Toughness:** Proteins are made up of folded amino acids. When heated, their bonds break apart and they assume a new shape. This is why an egg white goes from clear to white when heated. **Tenderness:** Heating up the connective tissue inside the muscle causes it to liquify which is what tenderness is. If you heat for a long time at lower heat, you do a lot melting and preserve moisture. Pressure cooking adds more energy while also keeping moisture inside."
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6
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