q_id
stringlengths 6
6
| title
stringlengths 3
299
| selftext
stringlengths 0
4.44k
| category
stringclasses 12
values | subreddit
stringclasses 1
value | answers
dict | title_urls
listlengths 1
1
| selftext_urls
listlengths 1
1
|
|---|---|---|---|---|---|---|---|
ly6vhb
|
Why heaters are placed near windows?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpr26ld",
"gpre0em",
"gpr528l"
],
"text": [
"If you put the heater on an interior wall opposite the window you would end up with a room that is cold near the window, hot near the heater and a range of temperature as you walk across the room. In short putting the heater at the coldest area provides better comfort.",
"Oo I know this one! It's because of the pandemic. No, not that one, the 1918 flu pandemic. As the 1918 flu pandemic raged, people looked around for something, anything to help protect themselves from the disease. Some people came across an idea from the late 1800s called \"The Fresh Air Movement\". The basic idea was that stale air put you at risk of catching disease and that the best way to prevent disease was to spend your time outdoors or in well ventilated rooms. That meant, keeping your windows open, no matter what. Buildings built after the pandemic were frequently designed to have the windows open all the time, and one of the ways open windows were accommodated was by placing the radiator directly below the window where it could heat the cold air coming in from outside. Eventually, under the window just became where the radiator went. Some more info here URL_0",
"This is often to cause convection. Cold air falls from the window and is warmed by the heater. This causes warm air to rise creating a convection current. This helps circulate heat throughout the space rather than just near the heater."
],
"score": [
15,
6,
3
],
"text_urls": [
[],
[
"https://www.npr.org/2020/12/10/945136599/how-spanish-flu-pandemic-changed-home-heat-radiators"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ly85xl
|
Why do birds not get shocked while they sit on high voltage transmission lines but people get shocked the moment they touch those lines?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpr8igf",
"gpr8kvm"
],
"text": [
"Humans die because when they touch it, they are touching something else as well, allowing a path for the current to flow. If You touch two separate wires You will die. If You touch a wire and the ground, you will die. A bird is only touching the one wire by itself",
"The birds on the line are not making a circuit to Earth so the current does not flow through them so they don’t get shocked."
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ly8aio
|
Why do we use revolving doors in some buildings? Why cant we just use normal doors?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpr934s",
"gpr9968",
"gpr9vjg",
"gprrmnt"
],
"text": [
"Revolving doors don't let as much air pass through when they're used. A standard door will let hot air out in the winter and cold air out in the summer. Revolving doors keep that air inside. The other thing that revolving doors do is relieve the stack effect in tall buildings. The stack effect is when the air inside a building is at a different pressure than the air outside. This pressure difference can make typical doors hard to open and/or make them slam shut when closing.",
"We could use normal doors - it's just a choice. But revolving doors have a couple of advantages: 1) you can use them even if your hands are full (eg with shopping bags) - hence they are quite popular in malls; 2) they don't let a blast of cold air into the building whenever someone comes through - hence they help keep the inside warmer.",
"A long with what everyone will mention about the temperature, it also makes for a more fluid entrance/exit. You can fit more people in less time fairly comfortably through revolving doors, as opposed to a regular door which fits *maybe* 2 people in the doorway at a time.",
"Revolving doors are usually placed in the entrance of buildings with large a open space. Temperature and air flow are some of the things to think about. A regular door can be left open which could let outside temperature in and drive heating/cooling bills higher. A revolving door is technically always closed to wind and outside temperature because there's no direct opening at any time it is in operation."
],
"score": [
165,
26,
12,
5
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
ly8mdy
|
what is happening in your brain when you lose consciousness?
|
Was curious about what causes you to gradually lose hearing and sight for a few seconds Edit: more accurate word would be fainting I think, not native
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gprbjf1",
"gprbawc"
],
"text": [
"In order to be conscious you need nearly half of the brain cells in your cerebral cortex to be active at any given time. If you fall below this level of activity, you lose consciousness. Other parts of the brain that control vision and hearing require a certain threshold in order to function too. If you're talking about losing hearing and sight for a few seconds when standing up (a so-called \"head rush\"), this is caused by reduced blood flow to the brain. When you stand up gravity pulls blood down to your legs and arms. The lack of blood flow in the brain means cells aren't getting oxygen and nutrients, so they can't function. Your body quickly fixes this by tightening blood vessels in your legs to squeezes the blood back up to your head. Imagine if you squeezed the bottom of a half-full water bottle. Once blood flow to your brain is restored everything starts working again.",
"Need to know more context. Like from getting a head injury? To cover some basic situations, cutting off blood flow quickly stresses the cells in your brain. Can't really sustain consciousness if the basic task of being alive is not going so well. It takes a lot of energy to sustain brain activity. From getting hit in the head it's because your brain was injured. You try doing work when someone kicks you in the gut haha. The networks get interrupted bc of injury. If it's real bad, you may have permanent brain damage. Mild is concussion. But don't be tricked, concussions are bad too. They can really fuck you up. Which makes sense: injuring your brain is bad. Sleep: it's part of a normal cycle of activity. Your brain is just going into a different operating mode basically. Normally it's in \"produce consciousness mode.\" Sleep is \"let's clean stuff\" mode. It has specific patterns of activity it goes through during that time. Last bit of info: consciousness is still mysterious. But we do know for sure that you need a functioning reticular activation system in the brain. If you damage that, no consciousness ever again. It's in the brain stem."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ly8tf3
|
How do we come up with complex formulas to explain different life phenomenons
|
For example, how did a group of scientist comes up with the formula of “Delicious cake= sqrt(Eggs + flour^3)+constant C”. And is it possible for one to develop and implement the thought process into their daily life?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gprckpc",
"gprcq1v"
],
"text": [
"Essentially two ways: 1) Derive it - i.e. take a bunch of equations we already know, combine and adapt them to the situation you're trying to describe and apply mathematical operations until you end up with a solution for your problem. 2) Empirically - conduct a lot of experiments, look at your data, think what kind of equation could describe the data, then fit it. Generally, if people describe a completely new phenomenon they start with (2) - although eventually someone might come up with a way to derive it from other, more fundamental laws. E.g. the classical laws governing gravity were found by people who measured movement of planets, then basically tried out equations to explain them, and then tried out different values for the gravitational constant until it fit.",
"Most of the basic formulas aren't really complex and built step by step. Volume of a cube is side^(3), that's simple. Mass is density\\*volume, so mass of a cube would be side^(3)\\*density. A momentum of a moving thing is mass\\*speed, so a momentum of a thrown cube would be side^(3)\\*density\\*speed. And so on. The thought process for most things isn't really that complex: thing A depends on things B, C and D, A gets four times bigger if you double B, two times bigger if you double C and two times smaller if you double D, so it's highly likely that A = B^(2)\\*C/D. More complex things appear when you apply mathematical operations like integration but that's still applying a well-defined operation to a simplier formula. Every part has a meaning and they combine into one large equation."
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
ly9xlz
|
Why is jumping from a bridge lethal?
|
Obviously I know hitting the surface of water flatly would be lethal but you should be able to stay relatively unharmed if you jump like divers do.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gprhue3",
"gprj83w"
],
"text": [
"There are a lot of bridges people jump from for sport regularly, and they come out perfectly healthy. If you're thinking \"suicide bridges\" like the golden gate bridge, it's a combination of extreme height (20-30 meter drive is ok, 70+ meters isn't), cold water, far distance to the next land, and strong currents that is deadly. One might be killed by the impact alone at that height, and it that's not the case, it's drowning with extra steps.",
"Have you ever swirled your finger around a pool of water, pretty easy right? Have you ever tried to swim with a nice fast stroke, that's a lot harder right? If you give the water time to move, it'll move around you quite nicely. If you try to force it aside, it'll resist and you'll need to use more strength. It takes force to move water. The more water you're trying to move or the faster you try to move it, the more force it'll take. If you're hitting the water at a terminal velocity or something approaching it, that water isn't moving in a hurry. Since the water isn't moving aside for you much, you're going to have a really hard landing. A bone-breaking, organ rupturing landing. And if you don't die on impact, now you're in the water with a body that's in no shape to swim."
],
"score": [
11,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyabin
|
Why can't you see stars during footage of spacewalks? Why does space appear totally black?
|
[For example]( URL_0 )
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gprjvhv",
"gprjerg",
"gprjxkw"
],
"text": [
"That's just to do with the camera settings. If you set the exposure to long enough that you'll see the stars, then everything in the foreground (astronauts, space shuttles, etc) will be really bright and washed out. In these photos, they don't want you to see the stars, they want you to see the astronauts. You're probably comparing these photos to what stars you'd see at night time. But these photos aren't taken at night, they're in direct sunlight. The stars are visible but they're much dimmer than you might expect because of the sunlight, and that's why you'd need pretty long exposure times to have them show up on camera. You can also try this yourself. Next time you're out at night, take a photo with your phone and see if the stars that you can see are visible on the photo. They probably won't be, except for maybe the brightest stars. Obviously, the cameras used for space photography are more powerful than your phone camera, but it's the same principle.",
"I'm just guessing, but it's probably because the camera is focused on a bright object or there's too much ambient light. Similar to how you can't see in the dark for a while after leaving a bright room or how you can see less stars in the city than in the country.",
"Spacewalks take place at daytime, and even at night they use powerful spotlights that make it as bright as day. You may be fooled because there is no blue sky above them but except for that the conditions are the same as a bright summer day here on the ground. So in order to be able to capture anything on camera they have to adjust them to daytime conditions. And with these settings the dim light from the stars is no longer visible. It is even hard to see the Moon with those settings, just like the Moon is very hard to see on daytime images taken on the ground."
],
"score": [
22,
12,
11
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyanjb
|
-If zero means 'nothing' and zero is considered the opposite of infinity, then does infinity mean 'everything'?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gprnjm3",
"gprmhzy",
"gprlnrp",
"gprlmoq",
"gprlun2"
],
"text": [
"1. Zero doesn't mean \"nothing.\" 2. Zero isn't considered the opposite of infinity. 3. Infinity doesn't mean \"everything.\"",
"Hopefully this helps before you go off into a deep end of metaphysical or mystical thinking. 1) Zero doesn't mean nothing. Zero is a quantity when added to any other quantity results in that quantity being preserved. ie x + 0 = x. Any number multiplied by zero results in zero. These are specific properties that only zero has. 2) Zero is not the 'opposite' of infinity. Consider the set of odd and even integers. We wouldn't say that odd numbers are the 'opposite' of even numbers. They are complementary sets. Using the same idea, the complement to zero is non-zero. There is no reason to say that infinity (not a number, by the way) has any property of 'opposite'-ness relative to zero. 3) Infinity is a concept, and assigning a meaning of 'everything' is more linguistic than mathematical. Infinity is tough to conceptualize but perhaps \"never ending\" is a better framework to think of it.",
"Infinity is more of a concept, literally just stating that there's no limit. I'll give an example. If you take a number like 2 and divide it by half and half again, and again. You could repeat this forever (infinitely) and never reach zero. Whilst zero is a number, Infinity is not.",
"I wouldn’t say that zero and infinity are considered opposites. Both infinity and zero can have different “meanings” depending on what you are measuring. If you are just counting objects, zero can mean nothing, but if you are counting time, zero is just the start of whatever you were doing. If you’re tracking change, zero means that things are the same as when they started.",
"In mathematics, an opposite number is the solution of the following equation: a^-1 = 1/a with a^-1 being the opposite of a. In mathematics, 1/0 is not infinite, same with 1/infinite which is not 0, because infinite is a bit too abstract, even for the abstract mathematics. To explain a bit more, we can extrapolate 1/0 with the limits and saying that 1/(something just sliiiiightly above 0) = (roughly close to infinite) and that 1/(something just sliiiiiightly blow 0) = (roughly close to negative infinite), but with our current tools in mathematics, we can't say that infinite is the opposite of zero."
],
"score": [
10,
6,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyb985
|
Why is self recognition in front of mirrors is an indicator of intelligence in animals?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gproivk",
"gprqe4w"
],
"text": [
"It shows that the animal has a concept of *self* which is an indicator of higher intellecttual activity. If it doesn't recognize itself, most probably it is either just walking around without any thinking, like a mechanical toy animated by evolutionary programming via basic instincts, or is just too dumb to recognize itself.",
"It's more a question of self awareness than anything. For the longest time, it was considered that there could be no intelligence without self awareness. One cannot change its own comportment, if one doesn't know it is something that can be impacted. If you don't know you are, you don't know you could be. Important to note that this method is not extremely reliable, and that some may be self aware even when failing the test, but that maybe eyesight isn't the way to go for them. Some were aware of their own song or scent."
],
"score": [
11,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lybmma
|
why are cameras fooled by superior mirages?
|
I was reading this [newspaper article about a hovering ship]( URL_0 ?) While I understand how the brain is fooled, why is a camera? Edit: it turns out I did not understand how the brain is fooled and everything else wrong with that statement! I still don't think I get this well enough to explain it to anyone else but I do really appreciate everyone who helped with answering. I have a better sense of it now, thank you all!
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gps04qa"
],
"text": [
"Light hits a camera sensor the same way that light hits an eyeball. Neither your brain nor the camera are \"fooled\"; they're both showing you a picture based on the light that hits them. If the light being detected by both of them is bent the same way, then they'll both end up with the same distorted image."
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lybq4w
|
Why are ultrasound devices restricted to medical personnel only? Can they be misused?
|
Edit: I'm referring to ultrasound imaging, not the vibrating wands you can buy online
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gprr7xk",
"gps2aem"
],
"text": [
"Ultrasound is not restricted to medical personnel. You can buy one from Amazon or E-bay very easily. X-ray machines tend to be restricted to medical personnel only (or other valid uses such as research) due to their use of ionizing radiation.",
"Never heard that. Ultrasound don't rely on radiation, it's just sound at different frequency. It may be expensive and difficult to operate, though. You need not just the machine itself but also some kind of software which can display the images in real-time. Also, you'd have to be able to use the machine, the software and most importantly be able to read and interpret the result, for it to be useful. Not sure if they are actually restricted items, but I wouldn't know what to do with one even if they gave me one for free."
],
"score": [
25,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyd2lo
|
What is the simple chemistry behind soaps, how is it polar and non polar at the same time?
|
Why does the formation of soap allow it to pick up different items?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gps03fj",
"gps5o8j",
"gps3f21"
],
"text": [
"soap molecules are relatively long molecules. The arrangement of the atoms (and their electrons) leads to one end being somewhat charged (polar) and the other end non-polar. Water is polar, so the polar end of the soap tends to \"stick\" to water, while the other end tends to stick non-polar things like grease. When you rinse with water, the water pulls the soap with the attached greasy thing down the drain",
"Eli5 Imagine a soap molecule is a long chain with two special velcro hooks on each end. One end of the chain likes to hook to water, the other end of the chain likes to hook to oils. When you cover your hands in soap, you’re moving these chains around your hands, and they find all the oils and nasty stuff and hook onto it. When you run the water, the water hooks onto the other end of the chain and carries the soap away, taking the nasty stuff with it.",
"Think of it like an adapter. Soaps have a small polar \"head\" (e.g. a sulfate group or carboxylate group) followed by a tail of nonpolar stuff (i.e. plain hydrocarbon chain). One end goes on the grease, one end goes on the water."
],
"score": [
31,
13,
8
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lydqxu
|
Why do we scream when we are in pain?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gps2lm6",
"gps299c"
],
"text": [
"We're a very social species. We have a lot of responses for letting others know what's going on with us. Many animals try to stay very quiet to hide themselves or their pain to avoid attracting attention. Humans attract attention on purpose because it'll also attract help from our group mates. Sounds of pain, panic or distress tend to immediately attract attention from bystanders.",
"It's actually known that screaming and saying obscenities decreases the intensity of the pain. So it likely was something that evolved over time, which explains why it seems like it is a reflex"
],
"score": [
25,
16
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyex9p
|
How do those walk-through scanners in libraries know if you're taking a book without borrowing it, especially if those books don't have metal inserts or anything like that?
|
How does the library borrowing system work? and how come even if there is no obvious metal insert in the book those gates still know when and when not to beep if the book has or hasn't been borrowed? & #x200B; EDIT: Thank you all so much for the answers!! : D
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpsad2q",
"gpt7fqy",
"gpsadz7",
"gptdkn6",
"gpsacx8",
"gpsg5i0",
"gpt115o",
"gptgm26",
"gptjspi",
"gpu7l25",
"gpwdrk4"
],
"text": [
"> especially if those books don't have metal inserts or anything like that? Because it DOES have metal inserts. They are called RFID chips, and they are very small and very cheap. You can even buy them. I suggest google image: \"rfid chips label and tags\"",
"I work in a fairly poor urban library and we do use RFID chips, which are great for self checkin and checkout. They're on everything, including wee DVDs. Every few years we have a run on toilet paper (in one series of instances, a lady would bring a bunch of kids in a couple times a week and they would break the paper holders and conceal massive amounts in the kids' backpacks). A bunch of RFID tags inside the TP rolls, and you've found the culprits. Moral: Don't steal from libraries. We're here to help you borrow things for free.",
"The most well-known anti-theft device for books is a tape of magnetic metal strip. The tapes are applied between the spine and the binding of a book (for hard covers) or deep inside in between some pages (for paperbacks). It's called **tattle-tape**.",
"Do you know how if you hold a tuning fork near your mouth and sing the right note, the fork will sing back? The books contain very thin \"tuning forks\" that look like stickers. The scanner you walk through emits a tone that causes any near by \"tuning forks\" to ring at that same frequency. The scanner then listens for the resonating forks and sounds an alarm if it hears any. You can't actually hear the frequency though because it is done with radio frequencies. Edit: It occurred to me that I didn't actually answer ops question. Basically when you check in or out the book it runs over a large magnet what wacks the tuning fork into and out of tune.",
"A lot of books have the metal inserts in their spine or in their cover where you can not see them. But it is not unlikely that the scanners are unable to pick up on every book, just the most valuable ones which have the metal inserts. The way these work is tha the metal inserts are in a perfect length to create a magnetic resonance that precisely matches that of the scanner. So when you walk through the scanner the magenetic field makes the metal inserts resonate which can be detected by the scanner. However during the checkout they use a magnet to change the magnetic characteristics of the metal insert and therefore its resonance frequency. This prevents it from triggering the scanners. This is also a reversable action so they can reset the books when you return them.",
"Oh, they have them. You just aren't seeing them easily, or they're outright hidden. There's a few ways they can mark the books. A common one is a microchip. However, they can also use a sticker (sometimes looks like a circuit) or even slide strips into the spine or under a book jacket without them being visible. These then can respond to radio or magnetic signals from the scanners, and they have some kind of code read by this device that says what the book is. The strip may also be able to be programmed to say if it is checked out or not; otherwise, the code will need to be compared to the code in the system and the status listed there. If the code says it isn't checked out, then it sends an alert.",
"My library has RFID tags (the stickers usually attached inside the cover) that uniquely identify all items. When you check it out the system then knows that specific item is borrowed and therefore to ignore it when it goes past the scanners.",
"In highschool i took the security tags out of a few xboxgames i got at the bargain bin and i stuck them under the cart for the projector, and for a few weeks every time someone rented a projector the alarms would go off",
"I think they have some sort of magnet, I used to work in my high school library and before we checked books out to other students we had to rub the binding against some metal... demagnetizing block? Thing? Edit: after reading the comments I finally understand what I was even doing, 9 years after the fact 😌",
"I used to work at a library for many years. One of my jobs was to put this tape along the inner binding that was magnetized. When a patron brought the books to the counter to check out we would rub them on this metal plate to demagnetize them. When bringing them back in we’d run a magnet along the binding to reactive it.",
"The library by my place uses RFID. You scan your card and just throw the books on a conveyer belt. It's weird to not talk to a librarian, but it's very easy. I wish my library was more like the old ones I went to back in the day. Dusty shelves, weird alcoves, big wood tables, comfy chairs. A nice old Carnegie library. Unfortunately, they're all modern in my area. Way too many new books, not enough oldness."
],
"score": [
1349,
147,
139,
34,
28,
13,
3,
3,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyfiv4
|
Why are we more physically powerful when being angry?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpsf1sn"
],
"text": [
"Your body makes chemicals based on your emotions. Sometimes, when you are stressed, that can include adrenaline and other things that make your body act differently. Among other things, Adrenaline pushes more blood to your muscles, giving them more oxygen and thus letting them work harder. Also, when you're angry, it's harder to control yourself. You don't always realize it, but oftentimes you are holding back a lot of things, emotionally and physically. Being angry makes you let go more and not hold back where you might have done without meaning to while normal. This can actually happen when you're afraid or in danger as well. This is related to people who push cars off of kids in moments of desperation. However, this latter extreme is also dangerous to reach, as it involves shutting off things that keep your body from being that strong to protect it - the body can be a lot stronger than we think it can, but doing so can hurt us badly, so it's designed to hold us back under normal circumstances."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lygxdj
|
What does it mean when immunologists say we need more research on transmission?
|
So the recent Moderna/Pfizer vaccine is said to be safe and effective. However, wouldn’t this entail that it prevents transmission? Any help would be great!
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpsmbbb",
"gpsojw1"
],
"text": [
"Maybe. It was a concern that the vaccines may inhibit the negative symptoms of the disease but could still allow vaccinated individuals to be essentially asymptomatic carriers. This was not thoroughly tested when the vaccines were initially rolled out, but studies have since shown that they do indeed reduce the viral load which mitigates transmission.",
"> However, wouldn’t this entail that it prevents transmission? Probably, but not necessarily. Some vaccines, like [the influenza vaccine, don't completely eliminate the ability to catch and spread the virus.]( URL_0 ) You inhale some virus, it infects your nasal tissue, it starts growing and releasing virus into your breath- and then your immune system crushes it before you feel sick or have any other problems. But you still have a short window where you're contagious. Many other vaccines make it completely impossible to spread virus. No one knows which pattern the new vaccine will be like, so we need more research. Note that the study I linked to is in pigs, which are a good study subject, because they live in close confinement. And note that the vaccine still reduced the spread, even though it didn't eliminate it completely."
],
"score": [
7,
3
],
"text_urls": [
[],
[
"https://pubmed.ncbi.nlm.nih.gov/33268518/"
]
]
}
|
[
"url"
] |
[
"url"
] |
lyhhz0
|
-how can a gun pack so much power?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpspija",
"gpsp00q"
],
"text": [
"By having an explosive transfer a ton of energy to a small, but fast moving piece of lead and copper: the bullet. That transfer of energy, from gunpowder to bullet, is then transfered again from bullet to target. The energy is extreme because of the power of the explosive being focused into a tiny bit of mass, Nd then focused even more by that tiny bit of mass being pointed and designed to penetrate what it strikes.",
"Gunpowder is a chemical explosive. What does that mean, basically? Well, it means that gunpowder is very unstable. Provided enough energy to give it a little \"push\" it will react with oxygen and release a bunch of energy as light and heat that it was storing in the chemical bonds holding it together. This energy can provide that same \"push\" to more gunpowder nearby. This means that you can create a chain reaction where a bunch of powder all explodes in an instant. If we use this heat to push a bullet, we can make it go very, very fast. Fast moving projectiles are, well, very deadly."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyhqqj
|
What is the senate filibuster?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpsr60t"
],
"text": [
"A filibuster is when a senator refuses to yield his time in order for a vote to be made. The traditional filibuster involves standing and talking for a very long time until its impossible to move to a vote. It is done by the opposing side of whatever bill is being passed and normally only done by the minority party in the senate. It used to be they would need to stand and talk for many hours but now because that is a giant waste of everyone's time all a person has to do is threaten to filibuster and if the majority party does not have a 2/3rds vote for cloture they just kill the bill. A 2/3rds vote is needed to just end debate and immediately move into voting on the bill .This saves senators from sitting through hours of reading of children's books or other random items to fill airtime. What this new model of someone not needing to stand and deliver a 20 hour speech to stop a bill leads to is basically nothing getting done in the senate if there is less than a 2/3rds vote."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyigh4
|
How do we know billionaires’ net worth so precisely?
|
Are their tax records public? Does Elon Musk just *tell* Forbes he’s worth 200 billion dollars? Can, say, Jeff Bezos lie about his net worth, and what will the repercussions be?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpsv6do",
"gpsv332",
"gpt3gjk",
"gptc6sc",
"gptsfpw"
],
"text": [
"For those guys, the vast majority of their wealth is in stock. If Jeff Bezos has 1 million shares of amzn and the stock price is $1000 then we would know he has a billion dollars in net worth. Additionally, because Amazon is a public company, his salary as CEO would have to be disclosed along with any stock that he sold. With a little investigation anyone could determine his net worth fairly accurately.",
"For the ones that started their companies and are the ceos or large shareholders that information needs to be disclosed publicly. After that it’s multiplying the shares they own by the share price.",
"Most billionaires have their wealth in stock in public companies, and large holdings of stocks are publicly disclosed. Add up all of their stock with the price, and you have most of their wealth accounted for. They may own lots of real estate, which is also public record, and approximate values are always available for that. We also know the expensive yachts and planes they own, and those usually have a known value. Musk is a bit harder. It's easy to see his wealth in Tesla stock as above. But SpaceX is a private company, and we know he owns about half of it. Then we have to value SpaceX, but we can't do that precisely because there's a lot a private company doesn't have to disclose. Forbes estimated recently when SpaceX did a round of funding for something like $800 million, specifying a dollar value per share. But it's not an exact science, as Morgan Stanley guessed the value of SpaceX about 30% higher than Forbes.",
"First of all, you're being quite mislead, the wealth of these people are, at *best*, just a educated guess on public info. Most wealthy people (when asked on these) have flat out stated that the values attributed to them aren't even correct, its just a rough guess. Even the people who make these lists are pretty certain they just fucking guess at best based on some basic info. For many wealthy business people, huge amounts of their wealth is in public stock of their companies. Their shareholdings are public so we know how much they hold. We also may know some of their real estate properties, as listings of selling prices are often public. However, it pretty much ends there. We don't really know anything else-- and there are TONs of other things going on. That is-- these are FAR from precise, they are essentially \"guesses\" based on what we know-- we know there are TONs we don't know, so they just act like those things don't exist.",
"We don’t. For example. Some of what these groups that make the lists do is contact the person and get the information from them. We now know Trump lied about his net worth to get on a Forbes list: URL_0 And then they typically don’t even put world leaders on the list as their net worth is often lied about. Like Putin is probably the world’s richest person but no one can verify. Muommar Gadaffi was one of the richest people in the world while alive but he wasn’t on it either. Too much unknown."
],
"score": [
17,
5,
5,
5,
3
],
"text_urls": [
[],
[],
[],
[],
[
"https://www.cbc.ca/radio/day6/gig-economy-workers-unite-trump-s-billion-dollar-con-hatari-vs-eurovision-ramadan-in-xinjiang-and-more-1.5126682/how-donald-trump-lied-his-way-onto-the-forbes-400-richest-people-list-1.5126688"
]
]
}
|
[
"url"
] |
[
"url"
] |
lyir0c
|
What’s an ‘Individuality Complex’?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpsx0tp",
"gptfwg3"
],
"text": [
"I suppose the better question would be to ask what ‘complex’ means in psychological terms",
"A complex in psychology is an attempt to attribute a difficult situation to someone's personal fixations. In modern times it's been rendered obsolete by more accurate psychological theories, and it's mostly use to be judgmental, \"Oh, you don't really believe XYZ, you just have an XYZ complex and you have to believe this for the sake of your weird obsession.\" An individuality complex is a persistent attempt to resist conformity, to the point where they make drastic or dangerous decisions because they don't want to be like everyone else. It's used a lot these days by right-wing trolls when someone say, comes out as trans, or dyes their hair, or some other thing they disapprove of, to imply that the person in question is just trying to get attention by doing something \"weird.\""
],
"score": [
6,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyisbo
|
If you ground up some seeds and planted them, could a plant still grow?
|
I’m curious if one would crush up seeds to where they are like crumbs or even powdery, could one still “plant” them and have something grow? And if not, why couldn’t something grow?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpsxc63",
"gpt3sfq",
"gpt3tt6"
],
"text": [
"No. Inside the seed there is already a fairly complicated set of tissues and organs that can quickly expand into a tiny little plant, but if they are ground up then they will very quickly die and not have any chance of ever sprouting.",
"No. A seed is not just a solid clump of matter, it's [composed of a bunch of things inside]( URL_1 ) it as you can see in [this picture]( URL_0 ) similar to an egg or an embryo. Grinding it up would destroy these completely and they would be unable to grow.",
"No. Ever try planting flour, whether wheat flour or corn meal? That's ground-up seeds. Seeds are not just like crystals of salt or sugar, the same exact thing all the way through. Seeds have a structure, which includes bits that can grow, and other bits that the growth parts depend on for their first food, and expect (need) to find in particular places in particular ways. Grind that structure up or crush it to smithereens, and the whole program, where the bits that could grow (even assuming they're still whole, which they probably aren't) depend on having exactly the right access to the other bits (that are now gone) goes out the window. (Basically, there's actually a little teensy baby plant inside the seed; grinding the seed is like putting an egg in a blender: the embryo is not going to become a chicken -- or for the seed, a new plant.)"
],
"score": [
25,
6,
3
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/File:Avocado_seed_diagram-en.svg",
"https://en.wikipedia.org/wiki/Seed#Structure"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyispi
|
How do the wave making machines at pools work
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpswxyq",
"gpu06hf",
"gpt71hy",
"gptd88l"
],
"text": [
"Pretty simple, really. They have a mechanism that moves large pieces in the bottom of the pools, like the floor or a section in the back. The faster they move those sections, the more energy is put into the water, and the bigger the waves. It's just like how you swish your arms around in a pool or bath and a wave generates. Your arm is only a small mass, so your personal waves are tiny and don't go far. But if a line of fat people were to start jumping up and down in time with each other, a larger wave can be made.",
"This video is pretty great at showing how the Disney water parks do it. URL_0",
"Big part with big piston pushes water with a lot of force at a certain speed. Each push is a wave. Slap your own butt, watch it ripple. Same thing.",
"One possible design: Behind the bars of the wall of a wavepool is another, shorter, thinner wall. The bottom of it is anchored to the bottom, while the top of it moves forward and back like page in a book. A mechanism like the one that can be seen on the side of train wheels keeps the top of the board pushing back and forth."
],
"score": [
51,
7,
6,
5
],
"text_urls": [
[],
[
"https://m.youtube.com/watch?v=gLNwDUwDk5I"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyjvhy
|
Cryptoart and NFT being bad for environment
|
I tried to read an article and google, but I still don't get it. Also, as a freelance artist should I make this? Is this a fad? Is it like pixel art?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpta4uh",
"gpt3zyj"
],
"text": [
"> Is this a fad? Probably yes, it is certainly a bubble. But it will probably stick around like a bad rash like cryptocurrency. > Is it like pixel art? No. > I still don't get it. It is “art” where ownership is secured by blockchain. Blockchain is a kind of database that is structured as it sounds, in a linear chain of blocks. Each block has a cryptographic hash which relates to the preceding block, meaning a chain of transactions can be verified without any central authority. The way it does this is extremely wasteful. The cryptographic hash is a mathematical process which is easy to do one way but extremely difficult to do the other direction. Anyone looking at the blockchain gets the easy side of the equation and can verify all the hashes are correct for each block in the chain. But how do you add new blocks if figuring out what the next hash should be is so difficult? You guess. Or rather a lot of people guess, over and over, billions of times a second until someone finally hits on the answer by chance. They then publish this new block to the entire community of independent blockchain peers who all easily check to see the hash is correct, and update their chains with the new block. As this happens over and over the blocks add up, and the most legitimate chain is considered to be the longest one. If someone wanted to alter the chain they would need to be able to figure out the cryptographic hashes for not just the block they wanted to change but also all the following ones, enough to get a chain longer than the current length. That would be prohibitively difficult since there are lots of people already guessing on the current end block so you would need more computing power (guess faster) than the collective group of people guessing (“mining”) on the chain. On the plus side this is a way of verifying a chain of events (such as ownership of a piece of art) without any central authority to keep track and in a way essentially impossible to alter after the fact. With thousands of independent records and a prohibitive calculation barrier it is effectively impossible to change and extremely secure. Unfortunately it also is killing the planet. All those people who are “guessing” for that hash solution are using computers to perform huge numbers of calculations, spending electricity to solve pointless math problems hoping one is eventually going to be correct. Imagine for example that you bought a painting. What is unique about this NFT painting is that when you buy it several people around the world light campfires specifically for your painting. They are going to keep burning those campfires, consuming fuel, *forever* because if those fires ever go out people won’t be sure who owns that painting anymore. This is essentially the same thing which is happening with bitcoin or any other blockchain cryptocurrency, it is a currency where each unit of currency starts several of those eternally burning fires across the world. Someone decided “Hey, what if we made a new system of currency which depends on and financially motivates the creation of an endless forest fire!”",
"Crypto \"mining\" eats up an absolutely absurd amount of electrical power. It's bad for the environment because it is create a huge demand for extra electrical generation."
],
"score": [
31,
12
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lykfh0
|
What exactly is the Big Bang theory?
|
Not the show
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpt7cmz",
"gpu2sme",
"gpt7stp",
"gpt6sla"
],
"text": [
"The theory that all the matter and energy in the universe was, at one time, condensed into a single infinitely small point. Then about 14.5 billion years ago it suddenly exploded and began expanding at an incredibly rapid rate. Over time, the universe continued to expand and cool eventually forming galaxies, stars, planets, and life. It's still expanding and cooling to this day, in fact the rate of expansion is increasing rather than decreasing as one might intuitively think.",
"ELI5: Think of all of the stuff that is in the universe. Like the sun. Do you know how big the sun is? It's way way way bigger than the Earth. And it's just one star. There are billions of stars in every galaxy. And there are billions of galaxies! Well, a very long time ago, all of that stuff used to be much, much closer together. The whole universe was crammed into a space that's smaller than even the period at the end of this sentence. Maybe even smaller still! And with all of the stuff in the universe crammed into a tiny space, that space would have been really really hot. Well, what happened was, from this tiny little space, all of the stuff in the universe started rushing away from each other. Almost like how an explosion sends stuff flying in every direction, but this would have been an explosion of the densest hottest stuff to have ever existed. This event, when suddenly all of the matter that would turn into the stars and planets of the universe started rushing apart, this event is called the Big Bang. You can probably understand why! And all this hot stuff started zipping away really really fast, and as it spread out it, it cooled down. As it cooled it was able to form things like atoms. And eventually stars, and planets, and rocks, and people and you! ---- ELI10: Do you know about the doppler effect? It's the reason why a car rushing past you goes EEEEEEEEEERRROOOOOOAAAM. The frequency of the sound changes based on if the car is coming towards you, or going away from you. In fact, if you were really clever, you could probably use a microphone and a computer to listen to cars driving past, and figure out how fast the cars went past you. Well, the doppler effect doesn't just work for sound. It works for all waves. For example, waves of light. When something is moving and giving off light, the color of that light will be slightly more red or more blue. We call this red shift or blue shift. Red shift means it's going away from you, and blue shift means it's coming towards you. It turns out that when we look at the light from really distant objects (like other galaxies), they are all red shifted. That means they are moving away from us. All of them. That's pretty weird. If the universe was static and unchanging, we would expect that some galaxies would randomly be moving towards us and others away from us. But the fact that they are all moving away is a clue that something else is going on. Namely, all the stuff of the universe used to be closer together. So we naturally asked, well, what would that have been like? How could we figure it out? One simple thing is to just \"play the clock backwards.\" Take all the velocites that all the galaxies have right now (moving away from us), and reverse the direction. Then just simulate how they got there. When we do this, we noticed that all the stuff we can see in the universe seems to have originated from a single point. At first this was seen as a silly idea. In fact, the term \"Big Bang\" was meant as an insult. It was seen as a joke. But as we've studied the universe, we've noticed more and more clues that hint to the Big Bang actually being a good description of what happened in the past. It really does seem to be that all of the matter in the universe was packed into a tiny space, and that it exploded outward in a giant rush of energy (the Big Bang) and that it continues to rush apart to this day. ---- ELI15: \"But hey,\" you ask 5 years later, \"isn't it weird that the Earth seems to be at the very center of everything? All galaxies are moving away from *us*. So are we, like, the very center of the universe?\" No, you're not the center of the universe, you're just a teenager so it feels that way. Let's take an empty balloon. Now let's draw some dots on the balloon. Now let's blow it up. Notice how all of the dots end up farther apart from every other dot? You can't say that any dot is the \"center\" of the expansion, but every dot would think of itself as the center. From the perspective of any given dot, what it sees is all dots moving away from it. But that does give us another clue: 5 years ago and 10 years ago I kept telling you about how all the \"stuff\" used to be packed close and how it rushed apart in the Big Bang. They was a lie. Well, it was the truth, but it was only a part of the truth. Because it's not just the stuff *in* space that used to be smaller. It was *space itself.* Just like our balloon analogy. So, at the instant of the Big Bang it wasn't as if all the matter in the universe was clumped together in a tiny ball surrounded by empty space. *Space itself,* and all the matter in it, was clumped up real small. So really, the Big Bang isn't the moment that all the matter in the universe began to expand, it's the moment when the *universe itself* began to expand, and all of the matter that was very hot and dense started to have some room to spread out and cool down. We're not really sure if that matter and energy somehow already existed inside an infinitley small singularity, or if something about the Big Bang created all of the matter and energy at the same instant that space began to expand. And when I told you that the universe is still expanding as a result of the Big Bang, that was a little bit of fib too. It's technically true, but we would have expected the universe's expansion to slow down over time as gravity exerted its pull. But instead, the universe's expansion seems to be speeding up! It takes energy to drive this expansion, and we can't see this energy. Because we can't see it, it's called \"dark energy.\" That doesn't really have anything to do with the Big Bang, but it might clear up some confusion. Oh, and another thing. You know how *space itself* was all tied up in a little tiny cramped space before it started to expand. Well, without the Big Bang, it wouldn't have been possible to make an X Y or Z axis. Space itself may have been packed into an infinitley small point with no dimensions at all. We're not really sure. But we're pretty sure that it wasn't just Space that was packed up in there. It was Time too. You've heard of Spacetime? That's a term because Space and Time are connected. They're all one big 4-dimmensional fabric that makes up our universe. So when the universe started to expand and suddenly we could distinguish between up and down and left and right, there was another dimension we could distinguish at that moment too: time. So if you think about it, time *began* at the Big Bang. We can't say anything happened *before* the Big Bang, because *time didn't exist.* The Big Bang is the sudden bursting outward in all directions of *The Universe Itself,* which includes time, space, and all of the stuff that is in it.",
"To expand on the other answers... The universe is constantly expanding. This was an important discovery made by Hubble that forever changed our understanding of the universe. He showed that there is a direct relationship between the speeds of galaxies and their distance from Earth. That doesn't mean Earth is at the center of the Universe, it's just that this relationship is defined relative to Earth. If we were on the Moon, everything would be moving away relative to the Moon. So since we know the universe is expanding, that means that it was smaller yesterday. And even smaller last year. And even smaller 100 years ago. Smaller 1 million years ago. You get the idea. Current observations have concluded that the universe was the smallest possible physical size around 14 billion years ago. Beyond that, no one knows yet. From 14 billion years ago onward is what we call the Big Bang: the rapid expansion of the universe from a singularity.",
"We see a complex Universe out there. The BBT is the best current scientific theory for How it got there. From a point singularity both spacetime and stuff expanded to what we see today."
],
"score": [
19,
9,
7,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lykn3h
|
how are the ears related to balance?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpt92n2",
"gpt9c1g",
"gpta80o"
],
"text": [
"Inside the ear are three fluid filled rings, one ring is flat like a floor, the 2nd is straight up and down, and the 3rd is on an angle between the first two. The rings are filled with a fluid and lined with tiny hairs. As you move around the fluid swishes in the rings and moves the hairs, like grass in the wind, which send \"I'm Moving!\" signals to the brain. The brain uses those signals, along with input from the eyes, to compile the sensation we call \"Balance\". Problems can arise when the hair-moving signals don't line up with our eye signals, for example if we spin around in a circle a lot and then stop moving. Our eyes say we're standing still but the fluid is still spinning in our ears which confuses our brains and make us dizzy.",
"its not the ear itself, its one of the internal organs in it a small set of very small bones and a \"container\" of sorts that are known as the Inner Ear system. in this system you have some fluid in a small bladder that has a number of nerve endings , this fluid is how our brain figure out the body's orientation, specifically if we are upright/laying down and if w e are moving or not when combined with information from your other senses. one of the most common issues that involve the inner Ear is Motion sickness aka, your inner Ear and your eyes are not agreeing on their info(the problem is motion you see but cant feel or motion that you feel but cant see, like for instance when you are sitting on a car as the passenger and reading.), so the brain freaks out and thinks its being poisoned and does the only think our evolution always proved to work: it induces Nausea to make you puke out what may be poisoning you.",
"Your ears have small tubes inside of them with a fluid inside of it. There are tiny hairs inside the tubes that can feel the motion of the fluid moving past them. There are tubes oriented in various axes so that when you rotate your head in any given direction it causes a little volume of that fluid to run through the tube to the other end. Your balance is tied to this because it's effectively a small gyroscope. Your body can sense the rotation rates and orientation of your head based on the position and flow velocity of the fluid in those tubes. There's a type of vertigo called benign paroxysmal positional vertigo or [BPPV]( URL_0 ). It occurs when there's some sort of blockage in one of those tubes. It could be inflammation from trauma or disease, or sometimes the chemistry of the fluid is altered and results in crystalization of a small amount into little stones that flow freely through the tube until they get wedged somewhere. When that happens it slows the flow of fluid around it. So in effect, you'll stand up and change your head position quickly, and reach a static position. You inner ear however is still seeing fluid flow because it's take a bit longer for the fluid to slide past the stone and your brain registers this the only way it knows how...your head must still be moving. It sends signals to your eyes to quickly make a jump to re-lock on a a different point in space and it creates this major disorientation, loss of balance, nausea, etc. To answer your question, the inner ear contains your vestibular system which is a really complex biological structure comprised of bones, tissues, nerves, etc., and perceives the motion of small amounts of fluid through canals. It has little semicircular canals for perceiving rotational movement, and something called an otolith for linear acceleration. The whole thing is quite fascinating and I'd recommend spending some time on youtube just scrolling through video after video on how it all works and what the effects are when it breaks down and doesn't function properly."
],
"score": [
20,
7,
4
],
"text_urls": [
[],
[],
[
"https://en.wikipedia.org/wiki/Benign_paroxysmal_positional_vertigo"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lykxkd
|
Why does the moon look bigger when it's close to the horizon?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gptbx62",
"gptaqvz",
"gptj858",
"gptj91u"
],
"text": [
"Have you ever found yourself staring at an image unable to tell what it is, and then suddenly something clicks and it’s so obvious that you can’t unsee it? Your vision is a very heavily processed image that your brain is actively editing on the fly. Even when the raw information doesn’t change, how your brain interprets those elements absolutely can and this results in a very different impression of the same image. When you look at the moon, your brain is making a guess as to how big it actually is based on context clues. When it’s up in the sky, you don’t have a lot of relatable context around it, so your brain says “that must be pretty big and pretty far away.” Except that the moon isn’t pretty big and pretty far away. It is absolutely massive and unfathomably far away in comparison to the scales your brain is used to working with. When the moon gets close to the horizon, you can see how big the moon is next to the distant stuff on the horizon and your brain suddenly gets a better indication that “Oh, that’s actually really big.”",
"You have the objects on the horizon to compare it to so it looks bigger. It is the same size when it is up in the sky but there are only stars and the Blackness of space behind it.",
"It is an optical illusion but we don't know what is happening. The size of a viewed object can be seen as angular (corresponding to the amount of space the object takes up in our visual field), or as physical size (its real size measured). Perceived sizes are related to both of these. Say if you are looking at two cars that are the same size but one is 10 feet away and the other is 20 feet. The more distant car will take up less of the visual field than the closer car. But we will still perceive the cars as the same size not half the size. This is called size constancy. Now with the moon we don't know if we are perceiving angular size as greater or the perceived physical size as greater. There is also the apparent distance phenomenon where we see objects on the horizon as farther away. However only about 5% of people will say that the moon looks larger and farther 90% say it looks larger and closer. The remain will say larger but the distance is the same. So this seems not to be the reason even though it is cited the most often in text! Another explanation is the apparent size. On the horizon the moon has a lot of objects to compare the size too so it looks bigger than when it's overhead where there is only endless sky to compare it to. There was also the angle of regard which it occurs because of the change of eyes in the head. However this has pretty much been dropped as an explanation because if you look through your legs at the moon the illusion doesn't change.",
"It is because you can see other objects like the horizon, distant buildings, trees, etc, and the moon appears behind them. Your brain interprets this as realizing the moon is really far away - and thus interprets the moon as very large (larger than those distant buildings). Looking straight up in the sky, there is just a moon. So you don't really have anything to estimate the distance of the moon, there are no cues on the size it should be."
],
"score": [
16,
6,
6,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lylsl5
|
Why do partners tend to creep over to your side of the bed when you sleep? Are we seeking heat? Comfort? Some science thing?
|
I don’t even know if this stereotype exists or just my experience, but yeah why is this happening or is it just one of those things?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gptj8bp",
"gpth7w9",
"gptivzc"
],
"text": [
"In the case of my boyfriend, it’s the comfort of being next to someone you love. In the case of my dogs, it’s because the world will end if they are more than 0.0000001cm from me. I’m happy with both.",
"For myself....in winter it's warmth. My wife gets as hot as an rbmk reactor at night and I'm freezing cold without her.",
"Best thing I ever did for my marriage was purchase a king sized mattress. I can't stand being touched when I sleep, and my wife turns into a 900kW heater when she's asleep."
],
"score": [
8,
7,
6
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lymzm0
|
why do beverages taste better out of a glass bottle vs a plastic bottle?
|
I imagine there’s nothing from the plastic that leaks into the liquid and affects the flavor, but maybe I’m wrong. First time poster, long time reader. I’ll hang up and listen.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gptzuw6",
"gptmat8",
"gptnlws"
],
"text": [
"There's a few different factors- Glass bottles, plastic bottles, and cans are all different material, and in the case of the can, have a coating inside to protect the aluminum. Glass is strong and nonreactive, while plastic bottles and cans (and the plastic coating inside the can) may degrade over time especially if left in improper conditions They are bottled differently which seems to result in slight differences in the level of carbonation. Different factories may have produced the product, sometimes you hear of \"Mexican coke\" being available in glass bottles which is a different recipe than the Coke mainly produced in the US & #x200B; Blind taste tests of beer have shown no bias towards canned or bottled beer (presumably all products used were stored correctly so no degradation of can coating was expected) Blind taste tests of soft drinks show cans, glass bottles, and plastic bottles taste different to each other, but without being able to tell exactly which was which",
"Glass is more chemically inert than aluminum or plastic so there's less going on that could affect the flavor of your beverage.",
"The molecules in glass don't F with other molecules. Glass got attitude. When a soda tastes weird from plastic or aluminum, it's because some of that plastic or aluminum has seeped into the combo of chemicals that make the soda what it is."
],
"score": [
8,
6,
6
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lynd3p
|
Why is NYC much colder than London (during winters) eventhough London is above NYC latitude wise.
|
In the Northern Hemisphere isn't cold weather directly proportional to the latitude. Closer to the poles ,more cold it gets. London is above the entire United States excluding Alaska. Yet NYC gets more snow and is colder.
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gptobfj",
"gptozxn"
],
"text": [
"There's a big ocean current that carries warm water from the Equator to the coast of Europe. This warm water warms the air and makes Europe much warmer than areas of comparable latitude in the Americas.",
"The Gulf Stream carries warm water up from near the equator towards Europe, and that's why most of Europe is warmer than you would expect at that latitude It's also why western europe is warmer than eastern europe."
],
"score": [
17,
8
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lynjb3
|
why does the skin gets shaggy after using filler and doesn't return to normal?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gptv6n9"
],
"text": [
"The fillers are injected in between the layers of skin and cause them to stretch to accommodate the filling chemicals. Once the chemicals wear off/degrade, the skin remains stretched as the collagen which makes it stretchy was destroyed by the fillers being injected."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lynwrt
|
How can people without much free time in their lives can be polymaths?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gptvauz"
],
"text": [
"Good time management, dedication and an effective learning strategy. It's not easy to be a polymath, hence why there aren't very many of them. But it's not so hard as to be impossible. Those who achieve it often seem to start by cultivating a good set of methods for learning new things, as many of the tools needed to learn are things that are applicable to a broad range of disciplines. Those with little free time are probably limited in how far they can get with it though. Psychological insights into polymathy have suggested that an important part of it is being in an environment conducive to creative expression, and the constant stress of a packed schedule probably is not that."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyoaeu
|
Vapour Liquid Equilibrium Data
|
I'm confused on VLE data, looking at methanol-water data from [ URL_0 ]( URL_0 ) You can see that the trend goes from x=0 y=0 methanol to x=1 y=1 methanol. How does this make sense. If I have a combination of water and methanol going in the feed, how can the liquid be pure methanol and the vapour be pure methanol and one extreme... or the liquid be pure water and vapour be pure water on the other extreme. In the first case where does the water go, in the second where does the methanol go? the trend doesn't even make sense. If the vapour is increasing in methanol it must mean that methanol from the liquid is being vapourized, so how can the liquids concentration also increase in methanol.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gptvctx"
],
"text": [
"So two parts to this: first those graphs are compiled empirically, based off experimental data. When you get that deep into chemical engineering/chemistry you start to get graphs like this where the explanation really is \"it just does, we've seen it and we can reproduce it\" and the \"why?\" aspects are the subject of ongoing research. So start there, its not a matter of it making sense, it is just what happens, if what you feel makes sense is different then there is a mistake in your reasoning (not that there is always/often a correct reasoning). Secondly the graph you will note doesn't actually have points at (1,1) or (0,0), because you are right thats not a physical state that can be achieved in real life (at least with current limitations). It goes from theoretical extreme to theoretical extreme to encompass the entire possible range should we one day add data to it, but it isn't expected to populate those end points. For your last point about the trend you are assuming a set starting concentration of methanol that moves up and down the graph, rather than different starting concentrations of methanol. The graph is saying \"higher concentrations of methanol in the water = higher concentrations of methanol in the vapor\" because you are at a stage where the starting concentration is higher."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyp315
|
Why beavers build dams?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gptz349",
"gptyvsc",
"gptze16",
"gptz9c5"
],
"text": [
"They like having their lodge (house) in a pond so that they can have only an underwater entrance. This keeps out rodents and snakes and the like. However, there are more beavers than ponds. They solve this by making a pond by building a dam.",
"They seek to control the worlds water supply. Real answer, I believe is to create lakes to build their homes in as They are partially under water.",
"Beavers like to live in little houses called lodges - a lodge sits along the bank or sometimes right on the water, and has an entrance underwater. This makes them really safe places from predators, because anything that wants to eat the beaver would have to swim underwater and find that entrance - predators aren't gonna do that, they'll give up and look for something else to eat. The thing about those lodges though is that they have to be built in still water, because running water would break them up. And if still water doesn't exist nearby, the beavers will have to make some. So beavers build a dam in order to stop that running water, create a still pond, and have a nice place to build their lodge.",
"Because they're unable to build sturdy lodges in running water. They instinctively dam rivers to make ponds and lakes that don't have much current to pull down their homes."
],
"score": [
20,
12,
6,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyrb97
|
How does a polygraph measure whether someone is lying?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpujuqc",
"gpugy5x",
"gpukusb",
"gpuofiq",
"gpujmjl"
],
"text": [
"They don't. It measures things like breathing rate & pulse. It only detects their body's functions. They ask questions to which the individual is instructed to tell the truth or lie so they can calibrate it. Loosely they watch for an adrenaline reaction when someone lies. Genuinely believe the lie, It won't work. Cause yourself pain when telling the truth it muddies results. Operators are what matter and even then nothing is definitive. Polygraphs can be beat, give false readings, or be interpreted incorrectly.",
"Not very well. It measures emotions like surprise and fear, which some liars are feeling, but other liars just don't have feelings like that.",
"Polygraphs measure many common signs of stress. The person running the test assumes that stress responses mean that the subject is lying. That's total nonsense, of course. Polygraphs are useless as evidence in court because they're laughably unscientific.",
"Honestly, if you resist taking one, they assume you are going to lie. A lie detector is slightly more accurate than flipping a coin to decide if someone is lying. Their purpose is intimidation.",
"It measures things like heart rate, perspiration, and breath rate, all of which *in theory* will change when someone tries to be deceptive. They begin the test by asking simple yes/no questions (\"Are you X,\" \"Were you born on Y,\" \"Are you married,\" etc) to establish a baseline, then monitor your vitals to see how they change (increased heart rate, faster breathing, and so on) to indicate you may not be telling the truth."
],
"score": [
22,
20,
8,
6,
4
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lys3ha
|
Why is the tech market crashing and how does it relate to bonds and inflation etc?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gpuu4wj"
],
"text": [
"When interest rates are low, many investors would rather invest their money in the stock market, where they can get higher returns, than buy treasury notes or bonds. Because COVID has shifted a lot of activity (work, school, and entertainment) online, tech stocks have generally performed well during the pandemic, and have been the focus of a lot of investing. However, as interest rates rise, some investors are selling their shares in tech stocks in order to buy treasury notes or bonds instead, causing the prices of those tech stocks to fall as supply exceeds demand at the current price. Other tech investors are seeing the stock prices fall, and are concerned more investors will pull out as interest rates continue to rise, and they sell as well."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lys5ww
|
What causes children to fall asleep quicker during a bedtime story rather than stimulating their brain and causing them to stay awake until the end?
|
I can't imagine falling asleep while listening to a story because curiosity about what happens next would keep me awake. Why is it different for children?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpvnb7e",
"gpussme",
"gpyk5lp",
"gpww7yl",
"gq1qmmj"
],
"text": [
"A bit of speculation here, but I think lots of people fall asleep more easily with the sound of someone talking. As a college teacher (and former college student) I can assure you this is not limited to small children. People naturally live in groups and nothing says \"safety\" like the sound of calm talking of familiar voices nearby. It indicates that other people in your group are awake and alert to potential threats but haven't seen anything concerning. Anyway, it's also worth noting that the average child has heard their usual bedtime story about a million times, so this isn't exactly a suspenseful plot engaging them, it's more of a familiar path.",
"It’s something to focus on instead of having your mind wander. They more than likely consider the voice reading it to them to be soothing and comfortable. The actual story doesn’t matter. I put on a playlist when I go to bed for the same reason.",
"The key factor is not just what a stimulated mind does, but it’s connection with activities that fundamentally keep you awake. Case in point, stimulating a mind with a story giving a child a singular focal point is going to be fundamentally less wakeful than the stimulation of mind with the freedom to act upon that stimulation and re-stimulate through that interaction. If a child is awake and out of bed, they have full use of their bodies to move around (to the extent of their developmental milestones) and minds active enough to want to play with anything that intrigues them. The entire world is a potential play ground. They can see an open cupboard and their imagination can spin that into a cave spelunking adventure. An alarm clock going off can become extra terrestrials attacking earth. If a child is out of bed, able to interact and create their own stories Now consider this child in a warm bed. Comforted by an adult figure who they see as a protector. They aren’t able to change much about their setting. If you read a new story, they might be very enthusiastic to hear it and they might actually stay awake for the same reason they would if they were up and playing. Because there’s lots of new ideas exciting them. But frequently, they’re going to ask for stories they already know. Stories they know they like. When kids are playing and they decide they want to play something different. It happens almost instantly. And they have the freedom to act upon that stimulation. If you read a child a book they’ve heard before 50 times, once they’ve heard the part they like they are left with: a comforting bed, a comforting voice, a story that is comforting, and that they already know all the words to. Tl;dr - A new story might keep a child awake. But rehearing a story will provide less stimulation than a child being out of bed. Because everything they touch and interact with becomes a story they can recreate or make for themselves. Imagination is a story that never ends and adapts to keep stimulating and re-stimulating. A book is imagination on a roller coaster. Stimulating when first experienced, but the track doesn’t change. Re-experiencing is chasing the dragon. Fundamentally less stimulating.",
"Children derive significant comfort from company, especially loving parental company. Bedtime stories being told in a rather soothing tone as opposed to playing them out like a terminator movie is a main factor in trying to mitigate the effect of engaging the child versus the gained comfort by acting out love for them.",
"It's also something as simple as establishing a routine. If we do these same three things in the same order every night, we should get the same result (kid goes to sleep more quickly)."
],
"score": [
28,
23,
5,
4,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lysjtl
|
Why do we hear sounds even when there is no sound?
|
For example, I am laying in bed now in silence but can hear a weird kind of ringing/humming noise
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gputtbp",
"gpuvx1a",
"gpxiug6"
],
"text": [
"One of a few things is happening: - you're actually hearing your blood pulsing through your ears (when it's quiet enough, this *is* possible). Blood moving makes sound...albeit not much! But when all *louder* sounds are gone, you can pick-up on the quieter ones - you may be hearing the slight movements of your body as you breathe and wobble slightly on your bedding - you may be suffering from tinnitus (ringing in the ears) - you may be experiencing the aural version of after-image - the effect of staring at something for a while, then closing your eyes and continuing to \"see\" it, albeit in negative color - you may be hearing tiny sounds in your house - water quietly flowing in the pipes, faint sounds of fans/motors running, etc",
"The ringing is your nervous system and the humming is your blood system. The humming could also be from the home's electrical system.",
"Perhaps slightly off subject, but I hear explosions sometimes as I´m falling asleep. Really loud (just one though). Took me years to find out it´s an actual thing, called exploding head syndrome. Apparently it can come as other types of sounds as well."
],
"score": [
20,
5,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lysnzd
|
Real photos from space
|
Are there any real photos that show the earth with the sun in the background for example? We always see footage of earth from space but I can’t find an image of the earth with another planet or the sun “in the background”. Is this a dumb question?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpuv1qp",
"gpuv9v7",
"gpuz4xd",
"gpx9htp"
],
"text": [
"It's not a dumb question at all if you're not big-time into photography. Think of it like this. You're in a basement, and there's no power. You don't have any source of light of your own, so to you, everything's dark. Suddenly someone turns their phone's \"flashlight\" on in your face. Ouch, right? \"Point that thing away from me\"? No WAY you're gonna make out details after that. So now think about if that giant flashlight is the sun. It's seriously super-overwhelming to most cameras. So most people plan their space pictures so it's not in the frame.",
"Well the other planets are just going to look like a tiny colored dot. The sun would be so bright it’d likely wash out the whole picture. The planets are so far away from each other, you’re not going to get a sci-fi style picture of two planets. edit: By no means is this a stupid question. There aren’t any stupid questions, you don’t know what you don’t know until you ask!",
"Other people have explained why you can't see Earth with the sun or other planets in the background. You can get Earth and the *Moon* in the same shot, though. It's rare because you have to get really far away, but it's [been done]( URL_0 )",
"How many planets you see on the night sky? Going to space will show just as many planets, the same size, assuming you stay anywhere near Earth. The sun is also kinda tricky since it is extremely bright. That means in a photograph it's almost impossible to have photo where you can see anything of Earth beside under-exposed blackness, or Sun won't end up being just a plain white over-exposed blot."
],
"score": [
19,
15,
9,
3
],
"text_urls": [
[],
[],
[
"https://spacenews.com/wp-content/uploads/2019/07/dscovr-earthmoon.jpg"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyszug
|
how exactly is the carbon footprint measured? And is it affected by the product being bio-degradable?
|
I read that plastic bags have a lower carbon footprint than paper bags, which confused me which would be better to use for the environment.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gpvmveb",
"gpv1twy"
],
"text": [
"I saw a convincing tweet that the \"carbon foorprint\" idea was pushed by big oil and industry as a way to distract from us banding together and passing laws to effect change.",
"Carbon footprint is an attempt to measure how much greenhouse gas is created by a product from the raw materials, through production, usage, all the way until it's thrown away. I don't know if the plastic bag thing is true or not. I don't want to look it up. But if we suppose that it's true for the sake of example, then paper may have a larger carbon footprint because of all the fuel burned by logging equipment, the energy used at the paper mill, fuel used by trucks moving logs and paper around."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyt3df
|
what are derivatives and how do they work
|
I am going into calc 1 and I cant brain why differentiation work. I know its like the rate of something changing at another rate but in a small interval. Like for example the derivative of x^2 is 2x. But 2x is a linear line, how does 2x actually show that the change? Is it a bunch of tiny 2x line stacked infinitely, thus forming the curve. If then, why can't we just use any other function to depict the change won't that work? Also why are there so many different ways to differentiate, like the product rule, quotient rule and others. How do I know which one to use?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gpv00et",
"gpv1ydt",
"gpv1m2w",
"gpvagze"
],
"text": [
"Think of a derivative as the instantaneous slope at every point on a curve. 2x is the derivative of x² because the slope of x² is twice the x value at each point. There are multiple rules because different types of functions require a different solutions to get that slope. Unfortunately, you just have to practice and memorize the rules, but it gets easier with time. *this is a slight oversimplification, but it's what helped me gain a more intuitive understanding of derivatives. I hope it helps. Edit: and the reason why you can't just plug in any linear equation is because it has to be tangent to the curve. If you plug in anything other than the actual derivative, your new line will immediately cross your curve, meaning it's not tangent.",
"The derivative is the rate of change at an instant X. Looking at a parabola, Y = X^(2), the rate of change of Y increases as X increase. Looking at it's derivative, dY/dX = 2X, you can see the rate of change increases as X increases. Thus, the rate of change of the parabola doubles as X increases giving it its parabolic shape. Likewise, the derivative of a linear function Y = X, is a constant because the rate of change between Y and X is constant.",
"Think of a car. The distance that the car is from the starting point over time is your initial graph. The speed of the car is the first derivative. If the speed is constant then the car will be moving away the starting point at a constant rate. So, the initial graph will be a sloped line and the first derivative will be a flat line. If the car is accelerating then the speed graph won't be a flat line, it will be a sloped line. That's because the speed is increasing with time. The acceleration would be the second derivative of the distance. Does that help?",
"> Like for example the derivative of x2 is 2x. But 2x is a linear line, how does 2x actually show that the change? Maybe it helps you to understand this if we first do an example without the whole \"small interval\" -thing. Let's actually use large intervals of time. Say I'm folding paper cranes, and I keep getting better at it so I keep getting cranes done faster. * During the first hour of the operation, I fold only 2 cranes. * During the second, I finish 4 cranes. * During the third hour, I finish 6. * During hour 4, I finish 8. * And so on. Now let's look at the total number of cranes lying around * After hour 1, there's 2 cranes finished. * After the second hour theres 2+4, which is 6 cranes. * After hour three, there's 2+4+6, which is 12 cranes. * After the fourth hour, we're at 2+4+6+8, which is 20 cranes. * And so on. If we look at the change in the number of cranes every hour, it looks like (2, 4, 6, 8, ...) - this is a linear increase, exactly the 2x you had. However, if we look at the total number of cranes, it goes like (2, 6, 12, 20, ...). It's faster than linear - not exactly the x^2 you gave, but not actually that far from it (x^2 would give 1, 4, 9, 16, ...). A derivative basically takes you from the total number of cranes to the number of new cranes at that given hour. The only real difference of the above to the derivatives you compute in calculus is that the above is divided into whole chunks of time, while derivatives are the same phoenomenon for continuous, indivisible changes: like for example if the original function is how much water is in your glass you're filling, and the derivative is how much is coming out of the tap at a given moment."
],
"score": [
9,
4,
4,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyt741
|
Why does balding occur primarily on the head in comparison to other parts of the body?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpv651h"
],
"text": [
"There are three different types of hair on the human body. The fine short hair all around the body except the palms, bottom of feet, back of ears and eyelids is called vellus. There is terminal hair that grows during and after puberty. It includes facial hair, leg hair, arm hair, feet hair and etc. Then there is head hair. The different types of hair are controlled by different genes and hormones so they hair loss doesn't need to be universal. Male pattern loss due to a combination of reasons but one is the circulation of dihydrotestosterone and facial/terminal hair isn't affected. However people can experince hair loss of head and body hair so it may just be more difficult for other people to notice someone else's loss of chest hair."
],
"score": [
20
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyt792
|
for breastfed infants who initially receive antibodies from their mom, how are those antibodies replicated?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpv0gmj",
"gpv33k2"
],
"text": [
"Short answer: they aren't. Think of mom's antibodies as a free trial of an adult immune system. Once that trial is up (typically around 3 months) then the kid is on their own and needs to develop their own antibodies, which they most likely have already begun to do. However, this is why early childhood vaccinations are important. Yes your child may essentially share an immune system with their mother for a time, but eventually they have to sink or swim on their own. Vaccinations are like swimming lessons for your immune system.",
"They aren't replicated. There are two types of immunity: active and passive. Each of these can be naturally or artificially acquired. Naturally acquired active immunity is when you come into contact with the pathogen and get infected. Artificially acquired active immunity comes from vaccines. Both of these make your body have an immune response, which makes two types of Activated B cells: Plasma cells and Memory B cells. The plasma cells fight the pathogen. The memory B cells stay in your body and will quickly activate if you are exposed to the pathogen again. Naturally acquired passive immunity is passed from mother to child via the placenta and breastfeeding. Those are passive and therefore you will not create memory cells. You will have the immunity for as long as you're breastfeeding. Artificially acquired passive immunity comes from injection of exogenous antibodies (basically foreign antibodies are injected into you.) Both of these last for as long as the antibodies stay in your body. Once they die off, your body hasn't created Memory cells, and you don't have immunity against the pathogen anymore. > All of this comes from the textbook \"Human Anatomy and Physiology\", by Marieb and Hoehn"
],
"score": [
10,
9
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lytcsw
|
If you have 2 of the same item, one heated to 100deg and one cooled to -100deg. Will their temperatures depreciate at the same rate or is one faster than the other?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gpv112n",
"gpvut07",
"gpv8dm2",
"gpv144s",
"gpvb5a5",
"gpvjha9"
],
"text": [
"You are missing one component that makes it impossible to know, actually a couple. But mainly, how warm is the room they are in. If the room is at 70 degrees, the 100 degree item will cool slower than the -100 degree item heats up. Because the 70 degree air won't be able to dissipate the heat as fast as lets say 30 degree air, or -20 degree air. There is still other factors too. For example, not all materials transfer heat and cooling at the same rate. So depending on what material the item was made out of, it might shed heat a lot faster than heat up.",
"Heat transfer is a really difficult subject with whacky equations governing the details, so the true answer is \"it depends on a lot of factors\". The temperature of each object affects the air flow around it, among other things. Heat transfer in a vacuum is not that interesting, so we can not go the typical simplifying route. Generally speaking, the factor that matters most for conductive heat transfer is the temperature of the item relative to its surroundings. In this case, reading your other posts, that is the same. So, their temperature would change at the same rate, and both items will reach equilibrium temperature at the same time. However, the hot item can also cool down due to radiative heat transfer. An object emits more radiative energy if it has a higher absolute temperature. This number scales by T^4. This number may not be that big at 100°, but it is there. tldr; there are too many factors to give a definite answer, but I'd put my money on cooling being very, very marginally faster in most cases.",
"Also, are they wet? What is the humidity? The cool one might get covered with frost, which would insulate it. The hot one would cool faster when wet if the air isn't saturated. What color are they? Is the airflow unrestricted, or is the object on a surface? Not enough info, bud",
"That depends on what the temperature of the room is and if the objects are being exposed to any light. If the objects are dark and being exposed to light then they will both be absorbing energy from that light and so the hot thing will cool down slower than the cold one heats up. But, all else being equal, if the room is at zero degrees then they should reach equilibrium in practically the same time.",
"To list some of the other things you need to consider: emissivity, reflectivity, absorption, mass, density, flow characteristics of the item and the environment, thermal conductivity with your heat sink/source, thermal conductivity through the material, surface area, types of energy sources in the environment, delta in temperature with the environment, and probably a few things I am forgetting. A great experiment to show that temperature and energy are not going to work quite how you think they will is to see how different temperature water melts ice cubes: hot still water will melt them slower than cold moving water. URL_0 The experiment is a bit disingenuous because moving hot water will melt the ice faster than moving cold water, but the point still stands that there are lots of things at work when heat moves around.",
"So im going to make a couple of assumptions here first. I am going to assume that these objects are metallic in nature and are placed in a nearly perfect vaccum and the \"temperature\" of this near perfect vaccum is 0deg. In this case, if the material of the bodies are metallic in nature, much of the temperature can be attributed to the kinetic energy of the electrons in the electron kernel. Heat can be transferred, if you ignore quantum mech for now, via conduction, convection and radiation. Since its a near perfect vaccum, the conduction factor is lower. However if you were to consider it, then the electrons with more KE can have more collissions with the particles in the free vaccum to transfer energy, but when you consider the element at - 100deg, the number of collissions between the particles in the vaccum and the ones on the plate are substantially lesser so the heat exchange doesnt happen more. When you take radiation into account, depending upon the reflectivity, emissivity and absorbtivity, the factors change but generally speaking, since objects at a lower temperature (considering a black body approx) radiates and absorbs at a lower rate/higher wavelength, the heat loss from the one at the lower temperature will be lesser. A similar concept also applies for non metallic plates. So technically, the one at the higher temp cools faster than the one at the lower temperature heating up."
],
"score": [
349,
211,
30,
15,
14,
5
],
"text_urls": [
[],
[],
[],
[],
[
"http://www.atozteacherstuff.com/pages/5881.shtml"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyu9oy
|
When an egg gets fertilized and cells start dividing, how do they know when/where to become different types of cells (skin, organs, etc.)?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpvdhrv",
"gpvfkhq"
],
"text": [
"It's been a long time since I've studied developmental biology, but if memory serves...the eli5 version might be this: As cells divide they have chemicals around them that tell them what to become. As more and more cells of certain types develop, the chemical mixtures change and that causes the newer cells to become different types. Think of it like having a rainbow on a paper and you need to sort fruit into the matching colors. As the colors change, you know to change from one fruit to the next.",
"Two things that I know about (keep in mind I am by means no expert and might have missed/ or misinterpreted some critical points). 1. DNA contained within the nucleus controls the cell and basically tells it what to do and where to go (this is biologically determined and why 99.9% of every animal species DNA is identical). 2. transcription factors that cell is exposed to before differentiating determine what what genes will be expressed in the nucleus and what the cells “job” essentially is/where it will reside within the body - hope this helps. This is my understanding of the phenomena and of course it’s way more complicated than this."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyuzy9
|
why does eating ‘bad food’ cause sounds / grumbled in the tummy
|
So I think I had some not great food (tasted a little funny but after two bites I didn’t notice) But here I am laying in bed and I’ve got a ton of ‘verbal’ feedback going on, regretting not sending it back. But… why would under cooked food or something cause your stomach to make noises?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpvemcd"
],
"text": [
"When your body detects that you have eaten something bad it tries to push that thing through your system as fast as possible. That process involves stimulating the muscles of the stomach and intestine to push the bad food along quickly."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyv4fj
|
Why does the human body sometimes have little twitches while they are falling asleep ?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpvg6iz",
"gpvfltj",
"gpxxjhk",
"gpwkzt8"
],
"text": [
"My wife looked pretty deep into this because I twitch HARD when I fall asleep. The way she explained it was like I fall asleep faster than my brain can deactivate that part that controls motor functions so it's like a signal that started but was inturrupted bc my body is like \"wait, he's asleep. Cancel that last transmission\" lol",
"You're describing a hypnagogic jerk. The unfortunate truth is that we don't currently have a good understanding of why they happen. It is known that when you're sleeping the part of your brain that would move your body is inactive. That's why you can dream that you're running but not actually be running. It's possible that this motor control deactivation takes time and will sometimes not be complete and so cause a jerk.",
"As you fall asleep, your brain thinks your body is dying, so it sends a pulse through to make sure everything is OK. - Dr. House",
"AFAIK: It´s simply an effect of the muscles going from superficial relaxation to deep relaxation. The neurological explanations I´ve read are detailed, but this is the essence of it. It can be particularly accentuated if you´re physically exhausted, because the body falls faster into sleep, and the transition for the muscles are more abrupt."
],
"score": [
52,
43,
6,
5
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyw4p2
|
How does stretching injure you when you're not flexible enough?
|
If you're flexible and you stretch your whole body in half you're fine, but if you're not flexible and you push past your comfort zone too much you can injure yourself. What actually changes?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpvp6yt"
],
"text": [
"Either your tendon with be strained, meaning it is stretched beyond its tensile limit and is damaged either in its elasticity or its structural integrity, or it is torn. These tears can occur anywhere along the tendon, but generally occur at or around the connection point between the tendon and the muscle. Iirc, the stretching limit of a tendon can be increased by exercise and practice by creating micro tears along the surface of the tendon, and allowing those to heal."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyw998
|
How are so many bits stored in a terabyte hard drive?
|
If I understand this correctly, a terabyte has 8 trillion bits. What amazes/confuses me is how we can fit *8* *trillion* individual little switches on such a small space and on top of that, accurately read data from it in the blink of an eye? I've tried my best to look into the topic online but can't find any (helpful) answers as to how these bits are actually being placed where they need to be.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpvso6q",
"gpwkqw7"
],
"text": [
"Different for HDD and SSD. HDD is just a very thin magnetic layer, the trick is to magnetize just a very small area by applying a short impulse of magnetic field with your read/write head. So it's pretty much like a CD, a bit is like a tiny \"hole\" but it can be overwritten. SSD is made like a CPU. Very tiny switches in nanometer size are \"printed\" on the silicon in the photolithographic process. In short you put photoresist on it, place a foil printed copy of your circuits above, shiny light on it to harden the photoresist, remove nonhardened photoresist, shoot conductive material on it whereever the photoresist doesn't prevent it. There are a bunch more details, but that fills a lecture and not an ELI5 post",
"There are two main storage systems today: Hard Disks (HDD) and Solid State Drives (SSD). Hard Disks are simply disks on which we deposit some magnetic dust which you can imagine to be organized in concentric circles. To read or write from this disk, there is a small arm with a magnetic tip that can be moved around. In this structure a bit is represented by a small stroke of a circle, so a tiny magnet in some sense. Since you’re more interested in bytes, a byte will be a line of these tiny magnets. Just like you number the pages of a book, you number the bytes to give them addresses in order to be able to know what you’re reading or you’re writing. So, from the outside, you ask “Can I read address number 1024?”, and the device moves the tiny head over the corresponding byte, reads the orientations of the tiny magnets and interprets them as 1s or 0s. Writing is basically the same thing, except that instead of reading, the magnetic tip magnetizes and turns the tiny magnets to write the data you wanted. Today we are able to make these magnets very very small and that’s how there are so many bits. ___ SSDs, instead, are directly made of transistors which, like you said, can be seen as switches. The special thing about these transistors, though, is that you can make them “get stuck”: a transistor which is stuck won’t turn on even if you try to. Explaining how the transistors are actually organized and why goes beyond ELI5, but imagine they are in a grid and, in this case, a byte can be 8 consecutive squares of a grid. When you ask “Can I read address 4096?”, your SSD tries to turn on the corresponding transistors, but some of them may be stuck! So only those that are not stuck will turn on, and will output a 0. The ones that don’t turn on output a 1, so you can directly read these signals. Writing consists in forcing transistors to get stuck or freeing those that are stuck according to the data that you want to write. It is interesting to know that this process slowly damages the transistors, and that’s why SSD have a fully fledged tiny computer inside of them that manages the internal structure to prevent you from overwriting the same region over and over again. SSDs are very dense because transistors can be immensely small, we’re talking about being a few nanometers long. ~~Remember that silicon atoms are 0.2 nm big, so we’re talking about having a thing as long as 50 silicon atoms!~~ I was wrong here because I should have considered the silicon lattice constant (the distance between silicon atoms in a crystal), which is instead about 0.5 nm. Even more impressive because there’s even less atoms! SSDs are also much faster than HDDs because HDDs are based on moving parts, but however fast you can make them move, they are still going to be infinitely slow with respect to the speed of electronics. Edit: fixed silicon lattice constant"
],
"score": [
15,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lywoev
|
How do people use the same set of vanilla beans over and over to make vanilla extract?
|
I've read that as you use some of your homemade vanilla extract, you can just refill the bottle (of unused extract and old beans) with some vodka, eternally. How does this work? Does it work? If it doesn't work, why exactly not?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gpvww9n",
"gpw32ib"
],
"text": [
"Logically this is ofc not true. Vanille is very strong so you can dilute it a lot but at some point it stops.",
"Vanilla extract is made by mixing vodka with vanilla beans. The vanillin is then extracted from the bean into the vodka. However at some point the vodka will be saturated while there is still some remaining vanillin in the beans. If you replace the vanilla extract with more vodka this remaining vanillin will be extracted as well. This second running will be much weaker then the first however so you have to use a lot more of it to get the same effect. A third running would be almost impossible as there is very little vanillin remaining in the beans. This way of multiple extractions is not exclusive to vanilla. You can do the same with other things such as tea and coffee. And you get the same effect when you for example use the same tea bag twice with the weaker second extraction."
],
"score": [
14,
9
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyx0rh
|
If dopamine, endorphin, oxytocin and serotonin are the happy chemicals, why can't we make a 'Happy Pill' with these 4 ingredients (akin to a multivatimin) to be taken once a day?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpw3v5d",
"gpw4kxp",
"gpw3ul0",
"gpwihpv",
"gpwffls",
"gpxf0k4",
"gpw4bu2",
"gpxgpm9",
"gpx5eq6",
"gpxmcjh"
],
"text": [
"They do a lot more than that. If you take too much dopamine, your body will start to shake. Too much seratonin can induce hallucinations. Also you don't really take like raw seratonin. You usually take precursors, or reuptake inhibitors. Not many things cross the blood brain barrier. You take chemicals that attach to the same receptors or that block the \"cleaning out\" of the neurotransmitter.",
"We can not use these exact ingredients because there is a brain blood barrier preventing them from passing from the blood stream into your brain. However there are other chemicals which are able to pass this barrier and trigger some of the same receptors though various other mechanisms. One of the best ones is cocaine which does what you suggest and makes you happy. But opioids and amphetamines also have similar effects. Some of these drugs are prescribed to help with various different forms of depression. The problem is that these happy chemicals have a very important role in the biology of the brain. They are the chemicals behind the reward mechanisms that helps you improve. So when you give people these drugs they do become more happy but their brain have a harder time to reward itself when doing something which would naturally make it happy. And this can create a negative spiral down towards terminal drug addiction.",
"We can. These things, or triggers for these things, are readily available in drugs today. They often either require a prescription or are illegal, however. You also wouldn't want to take them every day, as that would likely cause dependence, and to a degree limit the body's either ability or willingness to produce these chemicals in large enough quantities itself.",
"More happy chemicals = brain gets used to those amounts Brain gets used to those amounts = need more happy chemicals It's a very damaging cycle in the long run and it's a good example of \"too much of a good thing is bad\".",
"Because people are not supposed to be happy all the time. As far as nature is concerned, you're supposed to be looking for food and other stuff that makes you exists and procreate. Once you find it you can be happy for like a few minutes, but then you have to continue looking for it. If you were constantly happy, you wouldn't want to look for food, and would then starve. And that's literally what happens with people who take happy pills.",
"I'm on a mood stabilizer and they increased my dose. It tossed me right into hypomania. I felt fantastic but there were problems. I wasn't sleeping. I had the energy and the drive to do all the things but I also have a chronic illness and my body cannot do all the things. Plus you tend to make pretty lousy decisions when you think you're the best person ever. So they scaled my dose back a bit. I was upset because they took it away and I haven't felt good in so long but I understood. It was unsustainable.",
"Because it's a very delicate balance. If you flood the receptors, bad things end up happening.",
"It’s called ecstasy we already have this is pill form and as most people have said too much is bad I repeat don’t take ecstasy everyday.",
"Because it is difficult/impossible to titrate the dosages as as exquisitely as millions of years of evolution can. When the connection between action and reward is broken The results,in general, are less than satisfactory...",
"Other people have given good explanations for why you can't make a pill like that, so I'll give you a different take: There is something that does increase all those chemicals, it's called sleeping > 8 hours, eating healthy foods, and daily exercise. Most people don't realize, the vast majority of the neurotransmitters that make your brain function come from bacteria in your gut (I.e your microbiome). When you eat like shit, don't sleep, etc. You alter your microbiome and start producing less of the \"good\" chemicals and also more toxic byproducts which invade your nervous system. This system is so powerful, you can take poop (i.e. microbiome) from psychiatrically Ill patients and give it in pill form to healthy people, and they will develop similar symptoms (at least for depression and anxiety). The reverse has also been shown as well, you can give depressed/anxious people poop from healthy people and they will show reductions in symptoms. This same mechanism has also been demonstrated in parkinson's and other neurological conditions. URL_0 So when people say, \"you are what you eat\"..there's a lot of truth to that statement."
],
"score": [
392,
101,
74,
24,
15,
11,
6,
6,
4,
4
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7294648/"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyxb2d
|
Why is it, on average, less windy at night than during the day?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gpw9xf9"
],
"text": [
"Wind is generally caused by differences in temperatures between two air masses. Wind happens when the two masses interact and start to “swap” places. The sun tends to heat up air higher on the atmosphere which leads to larger air temp variances across a given area. Thus more wind. Less temperature variability at night means less wind."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyz3kh
|
Why do hang overs get worse the older you get?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpxepi6",
"gq1hqbm",
"gpxrxez",
"gpxa3mx",
"gq1g4ub",
"gpyq5xp",
"gq13s4e"
],
"text": [
"The toxins that makes you hungover (acetaldehyde and formaldehyde) stays in you / affects you more because the body gradually loses it´s ability to get rid of it. Another factor to make it worse can be increased alcohol intake with increased tolerance, allowing for higher levels of toxins.",
"When you get old enough, your body doesn't work as good fixing itself. Also you can tolerate more booboos before it really hurts. This added together means it takes more damage to feel pain and the damage you get takes longer to fix. On an non-ELI5 side, there are things you can do to help yourself feel better in the morning: * Drink a shit ton of water before you go to sleep * Take an advil in the morning * Drink better alcohol * Buy reasonable amounts to hard limit yourself * Nothing good comes after 2 AM * start earlier * drink the same amount over a longer period of time * pet your cat until they are annoyed * eat something in the morning (everyone has their own hangover meal) * Build up tolerance slowly * Befriend a genie * keep yourself busy instead of over drinking out of boredom",
"The older you get, the more effort it takes your body to filter out consumed alcohol. The left over toxins causes the feeling of a \"hangover\"",
"Alcohol dehydrates you until your liver filters it out. This is why you need to drink water first thing in the morning after drinking. Brain doesn't do too good if it's a bit dry... Most of the alcohol is taken care of as you sleep, and whatever hasn't been filtered causes a little ghost of being drunk. The combination of sleepiness, dehydration, and this tiny amount of alcohol causes the hangover. As you age, your liver isn't as efficient at filtering your blood as it was when you're younger, so when you wake up, your body has a little more alcohol than it used to, causing the hangover to feel much worse. Now I got this from some rudimentary research online that didn't really answer the question, causing me to have to fill in some blanks, so if it's not completely accurate, sorry.",
"Depends what you mean by getting older, while it is true that your metabolism slows down with age, it's not to the extent that you go from no hangover to feeling half dead in a couple of decades or even a lot less. However, there are numerous other factors, especially when combined, that can make it a lot worse. **- Fitness**: if you're less active, you will have more problems dealing with toxins, the impact will be bigger. Having a sedentary lifestyle does make your body feel a lot older than it actually is. **- Smoking:** if you smoke and this has be going on for several years, it will not only have made you less fit it will also have decreased your overal health. Not to mention smoking are extra toxins, and the longer you have been smoking, the more addicted you are and the more you will be smoking. This is also true for a lot **other drugs.** **- Adaption to alchohol:** when you first start drinking, your receptors are very sensitive to alcohol, which is also part of the reason why you get drunk so quickly, so if you need to consume more to have the same effect, it does come with extra toxins as well. But even if you quit drinking for years you'll never be as sensitive anymore as in the beginning, so the more you drink, the more alcohol you need to have the same effect, regardless fo habituation and addiction. **- Weight:** If you weigh more than you were younger, you need more alcohol to get to the same effect as well. **- Diet:** If your diet has become richer over the years, which is the case with many people, it will also make your liver work more, and that also means this extra work will be felt when you go a night out. **- Responsibility, sleep deprivation and stress levels:** the older you get the more responsibility you have, work for instance, which also means you will be more tired, yet you'll sleep less than you're younger. Stress levels will also change your hormonal balance. All this will make a lot more difficult to bounce back from a late night out. \\- Last but not least **money**: Don't underestimate how much more you drink simply because you can afford it. It's a major difference sharing a bottle with friends, or having to go out on a budget, compared to someone that can afford what he wants in terms of buying drinks, like a working person can. You'll drink quicker, you'll drink more , and you'll drink stronger stuff as well.",
"Alcohol works by binding to gaba receptors, and I guess keeping actual gaba from binding to these receptors (probably need help here). But my understanding of it is that gaba is responsible for our inhibition, hence drunk courage. Gaba also regulates/helps body temperature and blood flow. So when you get drunk, you basically screw with all these processes in your body that are pretty vital. Once you go to bed and wake up, your body is attempting to, I guess, recalibrate itself as all these receptors are now open to do their job again, so during this repair stage you feel all sorts of bad and strange. Couple this with what everyone else has said and it is not a good time. Finally, as you get older, your body does not deal with such changes nearly as well; younger people simply bounce back quicker. On top of healing better when you are younger, my guess is that you are still developing until about 25, so the body is simply used to variability in its chemical processes. Once your are a fully developed adult, your body does not want changes to happen and is less able to deal with them. Not sure if that's true or not but just a thought. This depends on the person, but for most people when you start getting towards and into your 30's, your body really starts to protest against the fun :(",
"Side note....anyone know why we get so horny when we’re hungover?...and is it the same for women?"
],
"score": [
143,
60,
41,
17,
8,
5,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyzq21
|
What the heck is Cryptoart?
|
I feel so dumb cause I've been reading so many explanations about it but I just can't seem to get it!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpyg8yn"
],
"text": [
"I'm going to skip all the math because it's not really important and other people have done really good explanations. Cryptocurrency works a lot like regular-cash-currency - if you have some, nobody else can take it from you without you spending it, you can easily transfer it to someone else, etc. And also like cash, it's *fungible* - my \"1 bitcoin\" functions exactly the same as your \"1 bitcoin\", and if I want to, I can divide mine into any size fraction I want to, and it's still all the same. There are other valuable items that are \"non-fungible\" - they're unique, and they can't be divided or reproduced without fundamentally changing them. Art is a good example - a rare painting that is worth 10 million dollars can't be split in half and sold to 2 people for 5 million each. We've now come up with a way to do a similar thing with math, just like we did for cryptocurrency - we can make \"Non-fungible tokens\" (NFTs) that serve as a sort of \"certificate of authenticity\" - you can only make one once, and you can prove that it's yours, until you transfer it to someone else - and now it's theirs and not yours. People are now experimenting with using NFTs to trade digital art. It's like buying the Mona Lisa - lots of people have photos or reproductions of the Mona Lisa, but only the Louvre has *the* Mona Lisa."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lyzqvo
|
How far of the universe can we actually 'see'? And how did we discover the ones that we can't.
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpxezbv"
],
"text": [
"We can only see one Universe, there's only one we're apart of. If you mean galaxies, then we can see more as time passes and technology grows. This is because as time goes on more light from things closer to the edge reach us, and as our tech grows we get more precise instruments. An example of the light traveling is even now if you look at the sun, everything you're seeing happened about 8 minutes ago. Even if the sun were to explode right now, you could read this before you would notice. It's sort of the same with when we say something is light years away. It takes light that long to reach us. So say a galaxy (or anything) just formed 10 light years away from us. We wouldn't know until 2031."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lyzsxk
|
Why cant we make all sorts of compounds and substances by manually forcing ions to combine?
|
for example, why cant we manually bond carbon and hydrogen atoms to make hydrocarbons?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gpxn3zg"
],
"text": [
"We can, but it doesn't happen spontaneously. All chemical reactions happen at random, but dependent on the energy state. We can force hydrocarbons to form by combining carbon monoxide and hydrogen at high temperature in the [Fischer–Tropsch process]( URL_0 ). It takes a tremendous amount more energy than it takes in, so we can't use it to turn CO2 in the air into fuel."
],
"score": [
8
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process"
]
]
}
|
[
"url"
] |
[
"url"
] |
lz0q77
|
I fell asleep in the hot tub. Why are my hands and feet wrinkled like I’m 100 years old and everything else is smooth?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpxubo4",
"gpxy20s"
],
"text": [
"I read somewhere that our hands and feet do that to have a better grip in water environments. I hope it’s true cuz that would be cool",
"It's so you can have a better grip. When your hands and feet wrinkle, what happens is your body is telling your blood vessels just below the skin to shrink, presumably because being wet makes things slippery and thus harder to grip."
],
"score": [
17,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz14de
|
Why do more men bald then women?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpy05o4"
],
"text": [
"1. Men have more testosterone 2. Men's bodies turn testosterone into a stronger form, called \"DHT\". 3. Some men's hair follicles are sensitive to DHT, and become damaged by it, which prevents them from making thick hairs."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz1hdv
|
How did banks in the past communicate to keep all they're customers accounts data in sync?
|
To make it clear, imagine we were in the late 1800s, I went to a bank in New York City to deposit 5000$. After that, I traveled to let's say Washington DC to withdraw some of that money. How did the bank in D.C. know that I had money in my account, in other words how did the NYC bank tell them? Edit: their\* {in the title}
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gpy2ais",
"gpy1q5f",
"gpy4884",
"gpzhtat",
"gq17mn4",
"gpyaqbw"
],
"text": [
"answer. Letters of credit. A person would carry a letter from their bank, authorizing another bank to give that person a certain amount.",
"In the 1800s they'd telegraph your home bank and ask them to write down your new balance. Before that it was done by letter, and could obviously take a while.",
"You would not be able to do it that easily back in the late 1800s. Your NY bank would not have a DC office and if they did they would not have the same accounts accessible at both places. What you would do if you wanted to transfer money between cities is not to go to the banks but instead go to the telegraph office, for example Western Union. The telegraph operator in NY is able to tell an operator in DC to pay out cash as per your instructions. The banks themselves would often rely on the telegraph to send money between the different offices but bank transfers between cities would still take some time and a lot of fees unlike our modern systems which is almost instant and free.",
"Letters, and telegrams, and eventually phone calls. There's a reason why people still have this idea of \"I'll pay cash now and you give me a better price\". Rather than waiting to see if a customer/client had good credit or enough funds to transfer ,they can receive instant cash now and bypass that whole process. Nowadays, any store can look up your credit instantly and they can be wired funds directly faster than it would take to count your bills.",
"Good [History Matters]( URL_0 ) video on how medieval banks worked. Banks were run by the same families who would relay information to one another. Experience/familiarity let them know when paper work was legit or not, of course made easier by dealing with a small number of potential clients and employees.",
"In the 19th century that would have been done by telegraph, and could have required a delay between the moment when you ask for your funds and the moment when the bank would have been ready to give it to you. Earlier the communication would probably have been the other way around. Your bank would have given you a letter certifying that you had this money and could withdraw it from their agency in the other place you were going to. In any cases, you'd most likely have planned that well in advance and taken dispositions with your bank at home before leaving."
],
"score": [
30,
17,
11,
8,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[
"https://www.youtube.com/watch?v=UE7nd36EpRU&ab_channel=HistoryMatters"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lz1kr7
|
how is my electronic device able to control the flow of electricity to parts such as camera without there being actual physical switches
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpy4b1e",
"gpy78rq"
],
"text": [
"Transistors are electronic switches, when you apply a voltage to them they allow current to flow. This means you can use electricity to control how electricity flows, by connecting transistors together you can use them to do logical operations and eventually mathematics, this is basically how a computer works.",
"There are things called transistors, and they have three wires. One is the input wire and current flows into it. One is the output wire and current flows out of it. The third wire is the control wire. If power is supplied to that wire, the switch is \"on\" and current flows through. If not, the switch is \"off.\" These transistors are everywhere. There are tens of billions of them in your phone's CPU alone."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz28j7
|
When using a bong how is the smoke able to travel through the water and come out again, in other words how come the water doesn’t just kill the smoke?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gpyldpd",
"gpyf0y7",
"gpyj0g2"
],
"text": [
"Similar to farting in the tub. The bottom stem is like a butthole and the smoke is similar to the fart, a mixture of small liquid and gas particles with some tiny solid particles in there. Note how smoke raises ashes and residue within its “stream”",
"For the same reason any other gas can travel through a liquid as a bubble without being turned into a liquid itself. Smoke is not just pure smoke, it's a mix of smoke and air (nitrogen, etc) itself. There are exchanges in content between the smoke bubbles and the liquid in the bong however, which occurs on the surface of the bubbles where the two solutions meet. Thus, the tar and other things are filtered out of the smoke and into the water, while compounds in the water get mixed into the smoke. That's why I wouldn't recommend smoking with pool water unless you want to breathe chlorine. Also, the more and smaller the bubbles, and the more agitation through the water, the more filtration occurs through the smoke.",
"It's like sipping something through a straw. Except there isn't enough water in the bong for you to get the water in your mouth. Pulling air through the bong creates a vacuum effect that pulls air through the bowl on the other side of the water and towards the source of the vacuum which is your mouth. If there wasn't an open air side (the bowl) on the other side of the water, it would 'die' like you mentioned."
],
"score": [
27,
6,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz2fql
|
The "buzz" sound happens when you got phone near your speakers and someone is about to call you. Why does the sound sometimes happens even if noone is calling you?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gpyesp8",
"gpyh53a"
],
"text": [
"Phones regularly communicate with towers to know what they're in range of. Sometimes you can be within similar range of 2 towers and your phone will switch back and forth. I havent noticed this sound since pre-3G services were discontinued in Australia. Why you should believe me: Its an educated guess, I could be wrong.",
"A speaker uses an electromagnet to make sound. This happens because electrical signals induce a current in a conductor like a wire. Current induces a magnetic field that causes the speaker to move relative to the permanent magnet, because magnets repel and attract. Your cell phone uses radio/microwaves to communicate. These are both electromagnetic signals, just like light (not relevant). These waves also induce magnetic fields in the wires of the speaker. If the signal is strong enough and at a frequency that your ears can hear, this will cause the speaker vibrate so that you can hear it."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz2yw8
|
Why do car tires lose air when sitting for a long time, but not when driven regularly?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpys1jw",
"gpzz4uh"
],
"text": [
"This is not something I've noticed before. I've had cars sit for a year or so, but never longer. Could be that over time the tire deforms a bit due to the pressure on it always being in the same spot. So then its not seated properly and a bit of air leaks past the seal.",
"They do lose air no matter what, but I suspect when a car is used regularly they tires are also checked during oil changes, other service appts, and topped off if necessary. Also, rubber may degrade/crack more quickly when the same part of tire is constantly absorbing all the weight/pressure of car vs. it being spread more evenly about the tire as it ends in a different spot each trip."
],
"score": [
4,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz326d
|
ĺWhy Do We Not Get Addicted To Specific Foods Or Vitamins?
|
Basically if i take a drug often enough i become addicted to it. If i perform an action often enough then i sort of get addicted to it but in a cognitive sense and it becomes a habit although that may be completely irrelevant to what im trying to say. In the simplest terms if i eat 3 bananas every day for months on end and stop eating them then why do i not get withdrawals from lack of potassium or if i eat tomatoes every day for years why do i not get withdrawal symptoms from whatever is inside tomatoes?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpyn3bk",
"gpyotxp",
"gpypdgp"
],
"text": [
"Different things have different effects on your body. If you eat 3 bananas every day for a long period of time and suddenly drop eating them without replacing the carbohydrates you may feel a bit fatigued but your body can regulate that loss a lot better than say something like alcohol which has a more extreme effect making the withdrawals more pronounced.",
"You can have a psychological addiction to bannanas or tomatoes, but that is different than the physical addiction of drugs. To understand why drugs can be addictive, but not banannas, we have to look at what is in them. On one hand, the main ingredient in a drug is likely to be some type of chemical which directly affects your brain. Our body doesnt have a way to \"deal\" with these chemicals, so they just make their way to your brain and connect with your neurons to create the effect of the drug. Our bodies than react to the increased activity in that part of the brain by making more neurons, and that process is what ultimately causes tolerance and withdrawal. A Bananna is different. Food is going to primarily have 3 things, Calorie molecules (protiens, fats, carbohydrates), water soluble vitamins, and fat soluble vitamins. None od these things directly affect our brain. Our body has to process them first. So when we eat an excess amount of calories, rather than having an effect on brain chemistry, our body just turns that energy into fat and stores it. The reaction is the same for fat soluble vitamins, rather then using the excess vitamins, our body knows to store them for later. Our body cant store water soluble vitamins. Excess of this type are usually just passed through your body and excreted as waste",
"People get addicted to things that trigger the reward center of the brain and that cant be replace by other things. So you can stop eating bananas, but still get whats in them from other foods. Sugar and carbs can be very addictive. If you eat a lot of sugary foods you definitely go though withdrawal if you stop. People that get \"hangry\" are generally people that eat a lot of carbs or sugar. Being hangry is basically carb withdrawal."
],
"score": [
4,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lz3ul8
|
As things turn from Solid-Liquid-Gas when they heat up, why do eggs turn from Liquid to Solid when cooked?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpytsyy"
],
"text": [
"It's not a phase change like melting or freezing is. It's a chemical change. Eggs contain protein in little rolled-up \"balls\" too small to see (the technical term is *albumin*). When heated up, these balls unravel into long chains that get tangled up, kind of like cords or strings that are stored together in a box tend to. This tangled net of protein stops the water and other liquids in the egg from flowing freely by blocking their movement, which turns the liquid egg into a solidified gel. (Gelatin works almost the same way.) Once they're tangled, they can't roll back up, so they stay in this state even when cooled down (which is a way to show that this *isn't* the same kind of change as melting or freezing, which reverse at the same temperature they happen)."
],
"score": [
11
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz411r
|
How are our buttholes able to control whether what we release is a solid or gas?
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gpyx98a",
"gpz7s72"
],
"text": [
"You have a special muscle called a sphincter in your butthole. It opens and closes to let poop out. If it only opens alittle, only gas can come out, not a solid. That is why if you have diarrhea you can't trust a fart. Gas and liquid can leak out the same.",
"As the other answers say, you have sphincter muscles that control whether things come out. The external is under conscious control, so you can open it a little to help prevent solid poop from coming out when you don't want it too. But the main thing is that pooping involves a whole coordination of reflexes and muscles working together. The internal sphincter only opens when there is stuff ready to come out, and the colon itself squeezes in a way to push the stool out (like toothpaste in a tube). Basically you need more things to happen for poop to come out, but you don't for gas to come out"
],
"score": [
20,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz48bb
|
Why do caffeinated drinks such as coffee or mountain dew make me tired or sleepy rather than making me energetic or hyper ? Is it just me or is it a common phenomenon ?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpyxqgg",
"gpzcsaq"
],
"text": [
"you might be neurodivergent. it tends to have that effect on people with adhd or autism, similar to how adderall makes people hyper but lets adhd people be calm and focused",
"Stimulants can exhaust your *adrenal glands* which help regulate energy and mood, among many other things. The bizarre irony is that the more stimulants we take on a regular basis, the more our adrenal glands become exhausted, thus requiring us to take *even more* stimulants. The alternative is to go clean for a few days, let your body reset and adrenals come back into balance. Exercise is a great way to build up lasting energy without the use of stimulants."
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz4old
|
How does body stretching work to increase elasticity instead of wearing down the parts?
|
I was stretching to be able to reach down and touch my toes (yeah, I'm inflexible) and realized that if my tendons were just elastic bands stretching them would only wear them down. But I don't know how the body makes it so people can go from extremely inflexible to (after some time stretching) extremely flexible. Are there health risks to being too flexible? Is there a limit to how much stretching the body can do every day?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gpzr39c",
"gpzdc81"
],
"text": [
"Almost graduated from PTA school, finished all my classes just got clinical rotations and board exams left so I can hopefully answer. Yes you can become too flexible. It’s called “hyper mobility” whereas most people are “hypo mobile.” Hyper mobility can cause strain to the joints and cartilage as well as making certain injuries more likely. The simplest explanation is think of your muscles like a rubber band. If you stretch it a little, it will go back to its normal shape. If you continually stretch it past a certain range, it will more easily stretch to that point in the future. If you stretch too far, bad things happen. So what is recommended is stretching muscles that are already warmed up from light cardio and dynamic stretches, and stretch to wear you feel a bit of tightness but not to where it hurts. Hold that stretch for ten seconds, relax a second, then go back into the stretch for 30-50 more seconds so 60 seconds max per stretch. Do this 3-4x a week",
"I’m not sure about the specific answer to how the elasticity increase works, but I can say from my own experience that the journey from completely inflexible (couldn’t get hands to touch the ground, couldn’t touch my knees with my upper body while sitting etc) to noticeable more flexible takes a few months of weekly stretching. I started yoga in November (twice a week) and my scoliosis back pains have pretty much completely disappeared and I am so much more flexible. My yoga teacher told me that why yoga helps especially fast is because while working out during class, we actively think about out muscles and tendons getting more elastic and flexible. Sounded like a classic spiritual motivation speech but a few weeks ago, I read actual scientific studies (one was even from Harvard) that found significant proof about how it is actually possible to only increase muscle strength by thinking about flexing specific muscles. 😅I don’t think there is any limit to how much stretching a day is good for you, think about the Eastern gurus who can bend in unbelievable poses and stuff without hurting themselves. It’s all about practise and not overdoing your personal limits."
],
"score": [
4,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lz5ck1
|
What happens if your eyes open whilst you're asleep, especially during REM? Can you suddenly see, or does vision get completely shutdown during sleep?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq08bh4",
"gq0xavb",
"gpzqc7b",
"gq1iluj",
"gq1wm5d"
],
"text": [
"It gets cut off. When I was a kid, I would hold open my brother’s eye during REM to watch it go back and forth. He never woke up. I still don’t think he knows I did that.",
"People here are saying that vision is cut off during REM, but this isn't quite true. There are devices that lucid dreamers use to trigger lucidity that work by shining a red LED into the eyes when you're dreaming (the expensive ones use brain waves, the mid-range ones detect eye movement, the cheap ones just use a timer to trigger when you're *probably* in REM). How the light is perceived in the dream varies, but most often it's seen as a change in the lighting of the dream scene, at which point you go \"hmm, that looks like it might be my magic gizmo, this is a dream!!?!?!?!1!one\" In my own experiments with lucid dreaming, I've also noticed that if there's light shining in my face during a dream, it interferes with my vision in the dream. It feels like I can't focus and the scene looks over-exposed or dark. I had an illuminating experience of my own demonstrating that vision during sleep isn't always restricted to just light. During my sleep, my eyes opened and I could see my bedroom, but I was still asleep and dreaming. I was lying on my side, but in my dream I was upright, so it felt like my room was tipped on its side and I was floating near the new ceiling! I woke up a moment later and realised what the weird view was. I also remember noticing when I was a kid that sometimes I could \"see\" my vision turning off as I fell asleep and coming back into play when I woke up, which was fun. The mechanism by which vision is turned off during sleep (to the extent that it does) is basically a matter of attention. If you pay attention to external stimuli (i.e. you *look* at something) you perceive it better, but if you pay attention to internal stimuli (e.g. you imagine something) you become less aware of what's right in front of you. The same happens during dreams, you're basically just not paying attention to what your eyes are seeing - mostly because all they can see is the unlit insides of your eyelids! One technique of getting into a lucid dream is to watch the imagery your mind produces as you're falling asleep and try to remain aware as you fall asleep and begin dreaming, you can see the multiple levels of vision which I see as threefold: 1. What your eyes see (which isn't much in the dark with your eyes closed) 2. Physiologically generated imagery (what your eyes and brain put together to try and make sense of the very limited stimulation caused by random firing of neurones in the retina / visual cortex) This is usually something similar to what you get when you rub your eyes hard - lots of colours and sometimes geometrical patterns. 3. (The exciting bit) Internally generated imagery. This is basically the same thing as what's in your mind's eye when you're imagining something or daydreaming or whatever, but if you're entering a REM cycle, this is what will hopefully soon become a dream. For this to work as a method of entering a lucid dream, you need to do it when your body's just about to enter REM, which can be done by working out the timing of your sleep cycles and setting an alarm to wake you up shortly before you'd normally enter REM, then doing the exercise above. :-)",
"Your vision gets completely shut down. Simply try closing your eyes and compare it to when your are asleep. With eyelids closed, if the environment is bright enough, you can still see some amount of light. However when you're asleep(losing consciousness), we don't feel anything at all, this is also true if our eyes are open. Personally, I do sleep with my eyelids semi-closed most of the time.",
"I sometimes sleep with my eyes open. I didn’t believe it when my brother told me when we were kids, but a couple of years ago I fell asleep during the Super Bowl in a lit room, and my eyes were wide open, and my friends took a picture of me to prove it. I suppose it just shuts off up to a certain threshold when you sleep, just like your ears.",
"I \"woke up\" during REM once. My eyes were still doing the back and forth movement, but I was awake and could see. It was highly disorienting and I had to lay back down and force myself back to sleep. 0/10 . Do not recommend."
],
"score": [
36,
29,
19,
5,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz5ejx
|
How do NASA rockets fly at 430,000 MPH when the fastest Jet in the world can only travel max 2500 MPH?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gpzbc16",
"gpzco1v",
"gpzc3tn",
"gpzguwx"
],
"text": [
"I think that's *much* faster than rockets go, but still, rockets do go much faster than jets. Jets take in air, burn fuel to heat it up, and then expel it out the back of the engine more quickly. Rockets aren't all that different. They just also carry the air to burn with them. The biggest difference is really scale. Rockets burn **much** more fuel and thus generate **much** more thrust. This lets them, despite being much bigger, accelerate more quickly to higher speeds.",
"Jets fly through the air, the faster you get the more resistance it'll give, slowing down and heating up the jet. Rockets tend to ascend enough that there's nearly no air to slow them down. Also they don't travel at 430,000 MPH even then, although they could if they had fuel to accelerate to that speed.",
"Planes use physical moving parts to move the air. Rockets just squirt juice out real fast, it's easier to design something to shoot a gas really fast than design a motor that can spin that fast.",
"What NASA rockets fly at 430,000 MPH and relative to what. The faster the space probe is the Parker Solar Probe and it reached 289,927 mph relative to the sun in September 2020. But if you calculate speed relative to the sun the average orbital speed of the earth is 66000 mph on average and a max of 67700 mph when we are closes to the sun. Aircraft speed is most of the time relative to the surrounding air. The probe used the initial orbital speed of earth so with that merriment the aircraft mover at that speed + earth rotation + speed relative to the air. 2500mph relative to the air at the equator where you have a tangential speed of the rotation of the earth at 1000 mph. So an aircraft would move at 67700+1000+2500=71200 mph if you measure like the space problem There is no absolute speed only speed relative to something. The solar system moves around the galaxy at 514,000 mph and the whole galaxy moves at 14 million mph towards a point in space called the great URL_0 speed measurement is always relative to something. The limit of aircraft speed is because of air resistance and stuff like the flow of air into the engines. The common usage of the word jet engine is one that uses atmospheric oxygen so it has to be used in a atmosphere. Rocket engines can make stuff go faster up in space where there is almost no atmosphere to create drag. Rockets bring their own oxygen if that is used to there is not need to move in an atosphere. The fastest crewed jet aircraft is the SR-71 and it has only managed 2100mph. But it is not the faster jet engines because the experimental NASA X-43 uses a hypersonic scramjet and reached 7546mph with a rocket booster to get up to speed where the hypersonic scramjet could work. So I have no idea what the 2500mph jet is."
],
"score": [
18,
6,
3,
3
],
"text_urls": [
[],
[],
[],
[
"attractors.So"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz5joz
|
What is the principle behind, "If you count it you change the outcome?" I've been seeing variations of this around lately and have no clue what it means.
|
Solved! Thanks everyone.
|
Mathematics
|
explainlikeimfive
|
{
"a_id": [
"gpzi2fe",
"gpzx50v",
"gpzyuo6",
"gq04brw"
],
"text": [
"There's a principle in human psychology / economics / business that whatever you track and incentivize, people will modify their behavior to take advantage of. If you start tracking the number of new accounts a salesman makes and promote or fire them based on that, but not how happy the customers are or how much they use the accounts, they'll start [lying to customers or even making up fake customer accounts]( URL_0 ) in order to meet their performance requirements. If you start making cruise ships pay for bilgewater dumping safely at ports, they'll [start dumping it unsafely]( URL_1 ) at sea. If you start giving all schoolchildren standardized tests that only test for a portion of what a well-rounded child should be capable of, the teachers will teach only what is on the test, and nothing else, and college preparation services will teach strategies for the test, and not actual useful knowledge, potentially making the schoolchildren more poorly-educated than they would have been without the test at all. It's important to select metrics that actually track what the goals of your organization are.",
"Simply and bluntly: You wanna know how prominent underage drinking is at a high school party. You (perhaps an adult) go there with a pen and clipboard and watch people at the party all night while taking notes on their drinking. Do you think you got accurate data? Many people would have left the party or avoided drinking around you. You changed how much alcohol was consumed.",
"In quantum physics the act of observing a quantum system makes it assume a defined state (which is what you observe and record) and eliminates the other possible quantum states that could've been if not for your act of observation.",
"There are various aspects of that. The other comments have already discussed it: in human sciences, measurement can incentivize; in physical sciences, measurement can affect what you measure (measuring air speed slows the air so modifies its speed); in quantum physics, observing is like forcing rolling dices to come to a rest (so you force a system that has multiple probable outcomes to collapse into one definite outcome when if you had not observed it it wouldn't have (I have no idea what it means either)."
],
"score": [
74,
27,
3,
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Wells_Fargo_account_fraud_scandal",
"https://apnews.com/article/70493d8ac89a4494ae8069e65ace67bb"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lz5uke
|
How did soldiers on medieval battlefields tell each other apart? Was 'friendly fire' common?
|
I know knights etc probably wore some sort of colours that would mark them out as being on one side or another, but particularly among the infantry who were often just peasants dressed in no particular uniform it seems like it would have been extremely hard to tell who you should be fighting. How did they do it? And are there many historical accounts of soldiers fighting the wrong people?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gpzkqne",
"gpzkc3w",
"gq024m5",
"gpzhcri"
],
"text": [
"The giant, chaotic, disordered, melees you see in movies weren’t how most battles were fought. Disorder = death. If you were in a battle and your side wasn’t in a tight and disciplined formation things were about to look very very bad for you. Better hope a “no quarter” order hasn’t been given to the folks who are about to butcher you and your buddies. These battles were all about being able to outmaneuver and flank the other side to get them to break formation. The opposing shield/spear walls were much more effective defensively than offensively so while everyone kept in position casualties were low. But once one side’s formation fell apart battles turned into a very one sided bloodbath.",
"Contrary to common movie depictions, battles weren't fought as chaotic melees. You fought as part of a unit that had been training together for months, so you know them personally. If you got separated from your unit, you would either run for your life, or look for a leader you recognize, who would probably have a flag or distinctive helmet to make it easier to find him.",
"In a brawl, the person with the better footwork has the upper hand. It doesn't matter how hard you punch if you trip over your own feet or the other guy is dancing circles around you. In a battle, it's very similar. Imagine if you and your mates form a loose gang of brawlers and you're walking up to the other side only to find out that they're shoulder to shoulder pointing spears and shields at you. It'll be really hard to put up much of a fight against that. You can run up and try to hit someone. But while you're doing that, the man behind him will be supporting him so he doesn't fall over. The man on one side of him will be protecting him with his shield. And the man on his other side will be attacking you as well. If you want to fight a ranked formation of men, you'd better bring a ranked formation of your own. Or they'll walk all over you. That also means, that your guys and theirs are pretty much facing each other in lines, which makes it pretty easy to tell the difference. Even before you get into things like uniforms, shields, armbands, banners, standards, and so on. Skirmishers are soldiers that fought in far loser formations with wide spacing. Ranked formations are not very agile, they couldn't just chase down any nuisance or they'd make themselves very vulnerable to opposing ranked formations. Skirmishers were essentially smaller, mobile units of harassers. Men with slings, javelins, bows etc. Their task was to harass opposing formations with missile fire, to exhaust and demoralize them before the melee between the big formations happened. Even then, they usually attacked the sides of large formations if possible. When anyone moved to engage the skirmishers, they usually ran away. Similarly, the cavalry didn't just make suicidal charges at large formations but was usually kept in reserve as a rapid response force that could circle around and attack the enemy flanks or backfield. The melees between large formations were kind of like lethal pushing matches. Lines of soldiers smashed into each other and try to inflict enough damage and terror to cause the opposing line to break and run. Which could sometimes take hours. The front ranks fight, the rear ranks brace the front ranks to stop them from being pushed over. It's also why spears and polearms were such popular weapons throughout history. They're cheap and simple to train soldiers in. And throughout history, there's a lot of weapons development to try and break this stalemate between formations. Roman soldiers threw weighted javelins right before the charge, the idea was that these would get stuck in enemy shields and weigh them down. If the enemy couldn't use their shields effectively, their shield wall would be much easier to break. Late medieval Landsknecht soldiers had a special combat role called the doppelsoldner. This literally means 'double pay' because it was a job so dangerous it paid extra. The job of the double soldner was to step out of the ranked formation and use a large sword to hack the opposing pikes to pieces. By breaking the enemy pikes, friendly pikes were longer and a stalemate could turn into a slaughter. Landsknecht soldiers also made use of the blunderbus to blast openings in the enemy line right before a charge. Any advantage that would help one line break another would quickly win a battle. But under normal circumstances, it wasn't hard to tell one side from the other. The other side is either immediately opposing you, or running away.",
"It depends one who was fighting whom. If you're in Europe fighting your neighboring village they may look a lot like you and it could be tough to tell. If you're fighting the Mongols everything about them may be different from their armor and weapons to speech to even hair styles. There were some methods to tell each other apart though. Sometimes they would use symbols on their shields. Other times it was simple as a colored armband might be used. So they did have some methods."
],
"score": [
89,
12,
12,
6
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lz6kza
|
How does so much frost accumulate in frozen veggies in an airtight bag in the freezer?
|
I buy them frozen, get them home frozen, keep them frozen, and the bag has no way for moisture to enter. There isn't much frost or excess moisture in there when you get them at the store. The longer they are in the freezer, the more frost they have. Where does all this extra moisture come from?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gpzmu3b"
],
"text": [
"The vegetables are not dried beforehand and contain moisture. Ice and frozen things still sublimate water in the freezer. Since this has nowhere to go it can still form ice crystals outside of the vegetables and inside the bag."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lz8yfy
|
why do bodyweight exercises not build muscle mass?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq029mh"
],
"text": [
"You have to tear muscle fibers to build muscle, which is still 100% possible with body weight exercises. It is just more difficult than with weights. The physique of the fitness people you see is much more likely related to their diet than their exercises."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lz9xh5
|
What is gaslighting? I have heard the term, but have no idea what it means.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq0b2z4",
"gq0ajxa",
"gq0hjbp",
"gq0azr5",
"gq0bn72",
"gq0avlm",
"gq0gw1n"
],
"text": [
"The term comes from a 1938 play of the same name. URL_0 In the play the antagonist, Jack, starts lying to his wife Bella about things she is sure she knows the truth of. For example, he steals and hides a piece of her jewelry and convinces Bella that she lost it. He also causes the gas lighting in their home to flicker and tells his wife that she's imagining things when she mentions it. The term now means to lie to someone about obvious things in order to make them doubt themselves about everything.",
"Making a concerted effort to lie to or deceive someone in a way that makes them doubt their own perceptions, senses, or sanity. It's from the title of the play *[Gas Light]( URL_0 )*",
"Yes, you should know what it means. I told you about it yesterday and the day before but as usual you continue to ignore me and be disrespectful. I’m through with your shit!",
"Gaslighting is a term use to define a type of psychological abuse, basically the abuser makes you question your sanity. The term comes from a old movie, Gaslight is the name. In the movie the husband manipulates his wife to the point she thinks she is crazy, that's an example of gaslighting. Usually the victim will feel anxious and will doubt about their own memories and experiences",
"Tactic used to get you to question your memories, sanity or perceptions. Politicians will use this technique to get you to question what you think you remember about a certain incident in order to get you to believe in their movement. It's also a technique used in abusive relationships to break down the memories and sanity of a partner, while also convincing that partner that they need to rely on the abuser more. Effectively stretching out the \"relationship\" for a long period of time",
"The term comes from a film in the 40s. It basically means undermining someone's sanity, often to ultimately control them. In the film the man turned down the gaslight but told the woman it didn't happen when she asked about it and she thought she was going mad. Now it's just become another over used internet term for when somebody questions something someone else says.",
"It’s messing with somebody by repeating lies or manipulating things to the point they question reality. Like people who’ve been trained their whole life to believe government officials and media, so when the GOO officials and conservative news media keep talking about voter fraud even though there have been almost no actual instances, they convince their supporters the election isn’t legitimate and laws need to be changed to stop fraud, etc. to try and undermine democratic institutions by weakening people’s confidence in them."
],
"score": [
27,
11,
10,
8,
7,
3,
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Gas_Light"
],
[
"https://en.wikipedia.org/wiki/Gas_Light"
],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lza0rn
|
How can you match up two light switches for one light bulb?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gq0bsyu"
],
"text": [
"Your hallway light is connected to a three-way switch circuit. It uses an extra pair of wires called traveler wires to allow two switches to control a single device. The only way to do what you want is to rewire the second switch and switch the traveler wires."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzay08
|
How did we figure out the daily norms of vitamins and minerals?
|
For example a person should consume about 65 to 90mg of vitamin C daily. How did figure this out, since everyone eats different food, has different metabolism, etc.?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq0lkzo",
"gq0mxbd"
],
"text": [
"The recommended daily intake values were first developed during World War II to make sure that soldiers and civilians were getting enough nutrients. Scientists looked at the available data to figure out how much of each of eight nutrients (this has since been expanded) to avoid a nutrient deficiency. They then added a bit extra as a margin of safety. You can read more here: URL_0",
"I heard this from a professor of physiology. He said during World War Two, the US did starvation experiments on conscious objectors in order to learn how best to treat concentration camp survivors after liberation. As part of these experiments, they learned the daily requirements of the various vitamins. The professor claimed to be one of the investigators, but I have no other source to verify this story, but it sounds feasible."
],
"score": [
37,
16
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Reference_Daily_Intake#History"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lzbjhs
|
if a person can be permanently put in a state of painlessness with drugs, can the inverse be done also — in constant pain — without a person becoming numb to it.
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq0qzkd",
"gq0r7dn"
],
"text": [
"Well yes of course. With the right stimulants, you can force the body in a perpetual state of pain. To avoid numbness you also need to keep the brain functioning at a high capacity.",
"Not necessarily with drugs - though it could be done with fairly subtle damage; minor spinal issues can be pretty hard to deal with, as it will take some pretty severe impairment for doctors to risk surgery. «Just» chronic pain, and you’ll be lucky to get painkillers."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzblbr
|
How does a country like Venezuela get hyperinflation with rates of over a million percent? How does a country ever solve that problem? Could that ever happen in Canada or the United States?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq109iv",
"gq0ts21"
],
"text": [
"So from what I have read so far, am I being accurate when I say that countries like the United States sell bonds to raise funds while in Venezuela they are simply printing money? Why does Venezuela continue to print unbacked currency when it will most certainly lead to the end of that government? It sounds like a form of nation suicide.",
"Printing money they don't have the means to back. Yes by taking in old money and switching it with currency thats trusted/backed. Yes it can happen to any nation, less often if they have a currency backed by real goods/services."
],
"score": [
7,
6
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzc06g
|
What actually happens when a website undergoes scheduled maintenance? Why can’t they stay online to make the changes?
|
Probably a stupid question, but I’m a stupid person so ;-;
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gq0ycpo"
],
"text": [
"It depends on a lot of things. It is rarely the same thing twice. But today you usually only get downtime when something involves a database or storage. I have been part of scheduled maintenance on a website caused by the fact that the station wagon we were loading all the data required to run the website into did not have the power or network access to run the website while we drove across town into another datacenter. You may think modern cloud computing have made away with this but all the major cloud providers do allow you to ship disks to and from them and they will ship disks between their own datacenters. This is the fastest and cheapest way to transfer data but there is some latency to it. That is of course an extreme situation that does not happen very often. But for example the last time I scheduled downtime for a website it was because one of the databases it used had some wrong settings and could not be upgraded. So we had to export all the data and import it into another database that were a later version and also had the correct settings. But in order to get a clean export of all the data in this particular database we had to make sure there were no changes in the meantime. So we had to shut down the website during the copy. On the other hand since we fixed this problem we will now never have the exact same problem again for this website. So the next scheduled downtime will be for something else."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lzd2xs
|
How the human stomach can separete solid from liquid?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq16se5",
"gq19bbd"
],
"text": [
"It doesn’t do that, the liquid separation happens in the intestines, where it gets absorbed though the thin walls, the stomach produces more acid so it doesn’t get diluted away",
"It doesn’t. Not sure where you got the idea. All food and liquids ingested get turned into sludge. As the sludge moves down your intestine, various things got absorbed into the lining, small molecules first, larger ones get broken down further etc. Before the last matter leaves the intestines, in the final stages, the walls absorb remaining water."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzetrw
|
Why does metal get cold when plastic does not?
|
When it’s cold out and you touch metal it’s always SO COLD, but plastic seems no colder than ambient. Why is that?
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gq1p5h1",
"gq1or2b",
"gq1p9h9",
"gq1wjnr",
"gq4mxlf",
"gq26alo",
"gq2kegp"
],
"text": [
"Metal is a good thermal conductor and plastic isn’t. It’s the same reason why metal gets so hot in the summer. A good thermal conductor means that they transfer heat to colder objects and also absorb heat from warmer objects. That’s why they lose so much heat in the winter. It is, in fact, a better thermal conductor than air is.",
"Metal conducts heat better than plastic. It absorbs the heat from your fingers/hands faster, feeling colder.",
"I believe it’s due to plastic being a terrible conductor of thermal energy. It is that cold but it’s so slow to transfer to your hand in comparison to metal which is highly efficient. Thus making metal seem colder then plastic. ELIF: Plastic thick and dumb, Metal is thin and smart",
"They are the same temperature! But metal transfers heat better, so when it's hot it feels very hot and when it's cold it feels very cold. It's because when you touch it, it very quickly brings your fingers to that temperature, and your fingers feel more comfortable when being at normal body temperature.",
"They're actually the same *temperature*, it's just that metal *transfers heat* into or out of itself faster than plastic does, and it's heat transfer that we feel as \"hot\" / \"cold\".",
"What you're feeling is the ability to conduct \"heat\", This is called \"thermal conductivity\" As your body is higher temperature than ambient, things that conduct thermal energy more feel colder, as the heat moves from your hand faster. metals generally conduct heat better than plastics, and therefore feel cooler than plastics.",
"You don’t FEEL temperature. Your skin isn’t a thermometer. What you feel is heat leaving or entering your skin. Heat leaving feels cold, heat entering is hot. Metal conducts heat well. If it’s room temperature it will be cooler than your hand. If your hand touches it, it sucks heat away from you very quickly until the metal is warmed up. This heat leaving quickly is what you feel. A different object made of wood or plastic could be the same temperature, but it wouldn’t steal your heat as quickly, so it doesn’t “feel” as cold."
],
"score": [
11,
6,
6,
5,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lzfbua
|
How do noise cancelling headphones/earphones work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gq1sxsv",
"gq1xcyv",
"gq1zwcw",
"gq20hxn"
],
"text": [
"There’s electronics inside that listen to the ambient noises around you, then they do what’s called phase cancellation where it makes a sound similar to it and puts it out of phase. The two noises then cancel each other out creating silence. Phase cancellation is wild but really cool",
"There's two types of noise cancelling. Active and Passive. Passive noise cancellation just means the headphones are designed to try and *physically* block sound from getting in. Just like covering your ears with your hands when there's a loud noise. Active noise cancelling /u/TheTalmidim explained better than I can. But, often active noise cancelling and passive noise cancelling tech are used together for maximum isolation.",
"Sounds moves in waves. A wave has a peak and a trough. Basically just a big up and down squiggle in the air and the \"zero\" is a line right down the middle. So part of the wave is above the line and part is below it. The part of the wave above the line is trying to push air up and the part below the line is trying to push air down. If the wave runs into another wave one of two things can happen: if the high part of one wave runs into the high part of the other wave their \"up energy\" combines and the peak gets even higher. So two three inch peaks become one 6 inch peak. Same if two parts of the down wave hit each other, they get even lower. If the waves hit a little different though they'll fight each other instead. A 6 inch peak runs into a 2 inch trough you get a 4 inch peak instead. The \"noise canceling\" comes in when you get identical waves. A 4 inch peak hitting a 4 inch trough just cancels each other. They're trying to move in opposite directions at exactly the same speed so nothing happens. What the headphones do is take in external noise with a microphone, wait a fraction of a second, and then replay it into your ear. The exact same sound is coming from the environment and the headphones but slightly different timing. If it's all working correctly, the delay will be just right so all the highs of the environmental wave hit all the lows of the headphones wave. Since it's the same wave then in theory they would cancel each other completely and you'd have dead silence so you would only hear the song or whatever from your headphones and no ambient noise. In practice it isn't flawless so you still can hear a bit usually but a good quality set will help a lot.",
"I’ll take a crack at it! Imagine a pond. There are peaks and valleys of the water as it moves up and down. If you made an exact copy of the pond and inverted it (peaks are now valleys and valleys are now peaks)..then put the copied pond exactly on top of the original. It would be a flat calm pond with no valleys or peaks. This is what the headphones are doing... but with sound waves (which are really just 3d versions of a pond)"
],
"score": [
148,
29,
18,
6
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzfbxe
|
Why do we nonstop smile when we are around and or, interacting with the person we like? On a chemical, or neurological level?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq1vg2j",
"gq27vbg",
"gq1vu5u"
],
"text": [
"Smiling is an expression that is the result of millions of years of evolution. All living non-human primates use non vocal expressions similar to the human smile (showing teeth with a closed jaw) to express submission and joy. We can then hypothesize, especially because people that were blind at birth smile, that smiling is so engrained in our DNA that it is instinctual rather than only a form of complex communication. A smile helps us practice empathy which is a defining trait of Homo sapiens but empathy isn’t unique to our species our ancestors used it for millions of years before we appeared",
"I dont smile when interacting with my wife. What kind of monster am I????",
"The chemicals that produce positive emotion that would make you smile is DOSE (dopamine, oxytocin, serotonin, endorphin)"
],
"score": [
11,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzg0l8
|
If the top of a mountain is colder and even contains snow, and heat is known to rise how come the top of a mountain isn’t hot and instead cold?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gq1xdib"
],
"text": [
"Heat doesn't rise. The air that rises if it is less dense than the layer of air above it. As the air moves up, it loses heat to the other molecules, and expands because of the lesser air pressure, becoming colder in the process."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzgbyr
|
How do pregnancy strips work? How can they tell from a person's urine she is pregnant or not?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq1yp9f",
"gq1z49x",
"gq1y6kn"
],
"text": [
"A person urinates on a strip that is specifically looking for the presence of a hormone called “human chorionic gonadotropin” (HCG for short). The only time your body will have this in the body and urine (because your body gets rid of extra hormones through urine) is when you’re pregnant. The test strip has antibodies on it which are proteins. The hormone (HCG) attaches to the proteins which have enzymes on them. An enzyme is also a protein that helps the reaction between the hormone and the antibody happen. The reaction is what will make the colored strip appear. If there is no HCG the reaction won’t happen and the color won’t appear.",
"The test strip contains different antibodies which are attached to the strip and unable to move. These antibodies also bind to hCG, creating something of a hCG sandwich between the two different antibodies. The enzyme on the mobile antibodies triggers a colour change in dye molecules on the test strip.",
"Its a chemical that woman make( i believe its a hormone) that gets passes through urinary tract. Its elevated when pregnant."
],
"score": [
28,
5,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzguqa
|
How do my bladder and colon know that I’m home?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq22cs0",
"gq2218k",
"gq21v4o",
"gq2udku",
"gq2vpak",
"gq2tyd6"
],
"text": [
"In short if you’re in a state of stress you can go indefinitely without a thought of relieving yourself but when the sense of danger subsides you feel that urgency.",
"3.9 billion years of evolution friend. The human brain is an amazing feat of evolution one sure thing it does without question is reacts to our environment. Humans may be the #1 predator on earth today but we evolved from animals that would’ve been a tasty treat on the menu. So when you’re comfortable in your environment you immediately become okay with being vulnerable, relieving yourself makes you vulnerable to a predator so if you need to but feel like you can’t you’re in a state of stress. When we realize we can be vulnerable in our environment your brain switches from fight or flight to normal. You know your house is the safest place you can be so your normal urges such as relieving yourself come into the forefront of your thinking.",
"I believe it has to do with the sympathetic and parasympathetic nervous systems. One is fight or flight when you're active and running around doing errands or exercising or your Adrenalin or anxiety is up your digestion is down. They are opposing systems so when you're home and comfortable the other takes over and you're relaxed enough for digestion",
"It's because you're intensely thinking about the bathroom when you get home and your brain prematurely sends a signal to your body that you have access to the toilet now. It's the same as how your body knows you're standing over or sitting on a toilet, except in your excitement to be home you're sending that message too early. It has nothing to do with stress. No idea why people are suggesting that.",
"This is formed out of your habit loop, which is cue > routine > reward. When you’re at home your cue is the need to pee, your routine is going to the toilet and the reward is an empty bladder. Because you’ve done this at home a million times your brain has stored this habit loop in the basal ganglia and it kicks in automatically. But you were out, activating other habits such as your errands, so the cue to use the toilet goes further back in the queue of habit loop autonomy. When you got home again and saw familiarity the basal ganglia activated the need to pee.",
"You know that large squishy thing in your skull? That tells them for you."
],
"score": [
65,
37,
7,
4,
4,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzh0lz
|
Why is the US labeled as one of the richest countries in the world while also being in an extreme amount of debt?
|
Are other countries just in *more* debt? Or is the wealth of a country calculated after factoring in debt?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gq233kn"
],
"text": [
"Countries don't keep money in their bank like people do. \"Countries\" are actually the companies that are in that country, and the economic output is the output of these companies. So companies don't keep money in the bank either, if there's a surplus of money it's much better to invest it in equipment or people to grow the company. So companies operate on debt, like a person would operate by using credit-cards only. They \"settle accounts\" and \"pay later\". A country's economy / wealth is calculated based on its Gross Domestic Product - the ability of its population to produce things. The debt is a normal part of business, and it only becomes an issue when the *interest* of this debt gets close to or becomes larger than the GDP's capability to pay it."
],
"score": [
10
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lzhb6a
|
Why does flipping your rear view mirror up tone down brightness?
|
When’s there’s an asshole behind you driving with their high beams on, why does flipping your rear view mirror up help?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq3xnih"
],
"text": [
"It's a triangular piece of glass. When mirror is down, you're seeing the reflection from the surface layer, which reflects most of the light to you. When you flip it up, you are seeing the reflection from the \"back\" layer, which reflects the little bit of light that passes through the surface layer and isn't reflected. The bulk of the light is still reflected by the surface layer, but up to the ceiling."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
lzhlqd
|
Why are there an equal number of men and women in the world?
|
Something with the mathematics of odds? 50% chance? Bro idk, explain it to me like I’m five.
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq25ope",
"gq25yal",
"gq2613c",
"gq268u9",
"gq27tqg"
],
"text": [
"There aren't necessarily, it's just a statistical average. In fact, looks like \"The Global sex ratio is 1.018. It means that we have slightly more men then women\" according to [here]( URL_0 ).",
"There aren't, actually. There are about 1% more men in the world than there are women, in part because the global population is pretty young. Many more boys are born than girls (about 8%), but men are more likely to die at all ages, so the ratio balances out around reproductive age. (By old age, women can outnumber men as much as 2 or 3 to 1.) But the answer to why they're close is [Fisher's principle]( URL_0 ): if there are more boys than girls, then genes that favor more girls are favorable. (For a sub-population example, think of a girl who is deeply into video games: she's in a male-dominated space and therefore can largely take her pick of available partners (and is very unlikely to be single for long if she really doesn't want to be). Similarly, imagine a guy in education or nursing: he has far more opportunities and options for partners than his female colleagues.) In this scenario, the genes that favor female offspring become more common, which reduces the disparity in available mates to close to zero.",
"Our DNA is bunch up into larger structures called chromosomes. We have 23 pairs of them. One of these pairs determines sex. The sex chromosomes come in one of two \"types\", X and Y. Women have two X chromosomes and men have one X and one Y. When we produce a reproductive cell (sperm or eggs), they each, essentially, get one chromosome from each of the 23 pairs. This means eggs always have an X chromosome but sperm may have an X or Y chromosome. About half of sperm cells have an X and half have a Y. This means about half of fertilized eggs end up with XX (female) and half XY (male).",
"Because a mammalian sperm emmission has an almost equal amount of X and Y chromosomes in each sperm cell so essentially there is a 50% chance of either delivering a male or female chromosome to the egg.",
"Technically i think that it's not exactly 50/50, but statistically, it makes sense to say its. To explain it first we have to understand that your sex is basically defined by the pair of sex chromosomes, in humans, females have the pair XX while males have the pair XY. Now whenever we create our reproductive cells (sperm for males eggs for females) this cell inherits only 1 of the two sex chromosomes, and it has an equal chance of inheriting either one. With that in mind, we can tell that the egg can only inherit an x chromosome but the sperm can either inherit the X chromosome or the Y chromosome, knowing that if the sperm inherits the X chromosome the offspring will be a female, and if inherits the Y chromosome the offspring will be a male, and knowing that both have an equal chance of happening, it stands to reason that the chance of the baby being a male or a female are 50/50"
],
"score": [
8,
7,
4,
3,
3
],
"text_urls": [
[
"https://countrymeters.info/en/World"
],
[
"https://en.wikipedia.org/wiki/Fisher%27s_principle"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
lzhncy
|
How many of the same stars do I see in Alberta, Canada that my brother sees in Minnesota, USA?
|
Earth Science
|
explainlikeimfive
|
{
"a_id": [
"gq26toi"
],
"text": [
"Most of them. You see a slice of the sky based on your latitude at any given time of year, and the difference in latitudes between the two is not large. The stars you see are stars up to 90 degrees equatorward of you on the [celestial sphere]( URL_1 ): if you live at 30 degrees North, you can see stars up to 60 degrees *South* (that is, 90 degrees south of your position at 30 N) of the celestial equator. Assume your brother lives in one of the major population centers of Minnesota (~45 degrees North) and you live near Edmonton, Alberta (~53 degrees North). You would then see the same stars except for an 8-degree-wide [spherical lune]( URL_0 ) that is visible in Minnesota but not in Alberta: your brother can see stars between 45 degrees south and 37 degrees south that you can't. These stars would be near the horizon in your brother's southern sky for a short time each night. On the other hand, you would see a very different sky from someone in Santiago, Chile (33 degrees South). You'd only share the stars between 57 N (the northerly limit of Santiago's sky) and 37 S (the southern limit of your sky), which is a little less than half the sky. The other half (your northern sky and Santiago's southern sky) would be unique to each of you. The only two skies with no overlap at all (barring some very small effects like atmospheric refraction and the wobble of the Earth's axis) are at the north pole (which can see only stars north of the celestial equator) and the south pole (which can only see stars south of it). Every other point on Earth can see stars near the celestial equator on the horizon."
],
"score": [
16
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Spherical_lune",
"https://en.wikipedia.org/wiki/Celestial_sphere"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzibj7
|
Why do atoms form ionic bonds?
|
We're learning about chemistry in school. My teacher says that atoms form bonds to reach lower energy, but this makes no sense. Consider, for example, table salt (Sodium Chloride): Firstly, how does chlorine **lose** energy when it **gains** an electron? That would be like if i became more hungry when i ate food, or got poorer when i got money. How does gaining something make chlorine lose energy? Does the electon have negative energy? Then, when the transaction is over, why do they still stay close to each other. Chlorine already got the electron, why does it still stay close to sodium? None of this makes sense to me. Explain it like i'm five. EDIT1: Now i understand why chlorine participates, but why does sodium participate. If sodium wants to reach a low energy state, then why does it form a bond that causes it to gain 496 kj/mol ? EDIT2: thank you everyone! now that my question is answered, i will delete my Reddit account.
|
Chemistry
|
explainlikeimfive
|
{
"a_id": [
"gq2bnd3"
],
"text": [
"> How does gaining something make chlorine lose energy? Does the electon have negative energy? No. But Cl^- has less energy than the original neutral chlorine atom *and* a free electron. Energy of Cl < Energy of Cl^- < Energy of Cl + Energy of e^(-). So the reaction Cl + e^- - > Cl^- *is* exothermic. The electron doesn't have negative energy, but it has *less* energy than it would have if it were free. The energy released by attaching an electron to a neutral atom is called [electron affinity]( URL_0 ), and it's very high for the halogens (like chlorine) that tend to act as the negative ion in an ionic compound. For chlorine, you get 349 kJ/mol for it. The corresponding concept - the energy to *remove* an electron and produce a *positive* ion - is the [first] [ionization energy]( URL_2 ). For sodium, it costs 496 kJ/mol to remove an electron. Wait a minute, you say. How is it that you can get an exothermic reaction when you're getting 349 kJ/mol out of spending 496 kJ/mol? The reason is that these numbers are measured **in the gaseous phase** for both ions **in isolation**. But the final step is that those newly-formed ions are extremely attracted to one another and want to form a solid, because they're oppositely charged. Bringing the two ions together as a single solid produces an extra 500 kJ/mol or so (beyond just what you'd get condensing each out as a solid itself), and it's the attraction between the newly formed ions (\"lattice energy\") that is ultimately the energetic step. Forming isolated Cl^- and Na^+ would be endothermic. [See this page for a full walkthrough of the energetics]( URL_1 )."
],
"score": [
5
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Electron_affinity",
"http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch7/whydoes.php",
"https://en.wikipedia.org/wiki/Ionization_energy"
]
]
}
|
[
"url"
] |
[
"url"
] |
lzir0e
|
Is it copyright infringement to steal from lost media?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq2cxn0",
"gq2d43e"
],
"text": [
"Technically it's still illegal copyright infringement. Practically speaking, if there are truly no copies of the original in existence, then no one can prove that you have actually infringed their copyright, so you're likely to get away with it.",
"A copyright lasts for 70 years. If there are substantial changes between the original and the copy, the copy could be deemed a derivative. If it is within the 70 years, permissions must be granted. The lack of an original is not a hindrance to the copyright holder. If you are taking some of this flick and some of that one, it could be deemed sampling, which has been determined by the courts to be works of art in their own rights."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lziulv
|
How did we find out about Atoms without being able to see them?
|
Physics
|
explainlikeimfive
|
{
"a_id": [
"gq2h40u",
"gq2harx"
],
"text": [
"Atoms were hypothesized before we had any evidence of them. There are many different tools and experiments that show evidence in favor of our current view of atoms. We have something called a Hadron Collider, that basically just shoots particles together and tries to record the results. But really there's a long history of us finding more info about atoms with different experiments that lead our model to evolve over time. There's not one way we discovered them. We used to believe electrons orbited the nucleus in similar patterns to planets around a sun, but now we have a much more complicated model for electron movement.",
"So. We had a few cool ways to estimate the look of an atom. One of the greatest ways we found out an atom was a tiny ball that was mostly space was with a radiation gun or neutron gun. So this smart guy in 1899 named Ruthford took some radioactive material and put it in a small lead box with one end open so the radioactivity went in one direction. Another great insulator of radioactivity is gold! So this guy took on of those very thin sheets of gold foil you use for gilding things and put it a bit of a ways away in the center of a circle This circle was a small wall that was made of a fluorescent material (glow in the dark stuff) His original test was to see about the different kinds of radioactivity, where some types were blocked by gold and some when strait through. He noticed somthing though. When he set this up he found that the bata radioactivity did go through the gold as expected and it lit up the fluorescent screen..... but there were some small bits lighting up in way different areas. Kinda like a ricochet. His famous quote is \"it's like you fired a 15 inch shell at some tissue paper, and it coming back. So he though about what would cause that and his hypothesis was that the radiation was hitting a small round object and then rebounding. Kinda like a bunch of marbles spaced out, then you throwing more at them. Thus the atomic structure was hypothesized and built. Kinda crazy that we are only 120 years into it"
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzj89m
|
Why do we say something amazing us extraordinary if 'ordinary' isn't amazing?
|
If something is ordinary, it's normal. So if something is extraordinary, isn't it extra normal?
|
Other
|
explainlikeimfive
|
{
"a_id": [
"gq2fddr",
"gq2figi"
],
"text": [
"extra as a prefix means \"outside of\". Eg at school \"extracurricular\" activities are those beyond the normal classroom / prescribed learning. So that which is extraordinary is outside of the ordinary, so not ordinary at all. edit: another example: \"extraterrestrial\". Terrestrial stuff is stuff related to the planet Earth, so something \"extraterrestrial\" comes from space or planets outside our own world",
"The prefix \"extra-\" derives from Latin, meaning outside of or beyond. So something that is extraordinary is beyond the ordinary. The modern meaning of extra comes from shortening the word extraordinary. URL_0"
],
"score": [
23,
9
],
"text_urls": [
[],
[
"https://www.etymonline.com/search?q=extra"
]
]
}
|
[
"url"
] |
[
"url"
] |
lzjwee
|
How and why do people sleep walk?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq2qdyl"
],
"text": [
"The mechanism that \"turns off\" motor movement malfunctions. This can go the other way \"Sleep Paralysis\" is when your nervous system failed to turn on your motor system - you lay in bed unable to move. It can be stress, drugs or a genetic factor. Rose McGowan used to sleep walk - at one point her family had to go looking for her and found her miles away curled up in a snowbank. She says that nowadays she just speaks Italian in her sleep. As to why the movement suppression goes haywire, that's still up in the air. Some think it has to do with part of the brain maturing late (hence why Ms. McGowan only speaks Italian in her sleep now). Hit this link up for more: [ URL_0 ]( URL_0 )"
],
"score": [
5
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Sleepwalking#Causes"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzjwz4
|
Why are some animals extremely slow (sloths and turtles) when they're size doesn't justify it?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq2k59x",
"gq2tjq3"
],
"text": [
"Slow metabolism and/or no real reason for them to be fast in the first place. Predators need to move fast to catch their dinner. Prey need to move quickly to not become dinner. But sloths and turtles don't need to chase the plants they eat, and they're generally armored/camouflaged enough to not need to worry about predators much at all.",
"Most organisms are in a constant struggle to obtain enough energy. Obtaining energy is often dangerous. You have to risk injury in a hunt or leave your safe burrow to risk predation. There are many strategies for coping with this. Some organisms stay very small so they don't need much food. Others evolve to eat almost anything so it becomes a lot easier to find the energy or they evolve to eat food that most other animals can't like some kind of poisonous plant. A very popular strategy is to simply minimize the amount of energy they need. Many predators are ambush predators for instance. They just sit and wait in a suitable spot until a meal passes by. Sloths take energy conservation to extremes. They have very slow metabolisms that require very little energy. This also means that they put out very little energy for the sloth to work with, which makes them slow. Every other aspect of a sloth is evolved to deal with this. They're very slow obviously, but also very well camouflaged to keep them safe. They're very lightweight, allowing them to climb to the high. thin branches of a tree where predators have a hard time getting at them. They need very little water. Their slow, jerky movements are hard to recognize as prey by predators. Even their body temperature is very low for a mammal to reduce energy needs. And body temperature is a big one. Warmblooded animals spend a huge amount of energy permanently keeping their bodies warm. It's kinda like keeping the engine of a car idling, you don't always need it but it does keep you ready to explode into action at a moment's notice. Cold-blooded animals don't waste any energy keeping their body temperature up. They use environmental warmth like the sun to warm up their bodies to the point where their muscles and body chemistry work well. It allows them to survive on a lot less food. Turtles evolved their shells as a defence on top of that but it does limit their range of motion a fair bit. Reptiles, including turtles, can produce very quick bursts of speed. But with their shell inhibiting their movement, they'll never be speedsters."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzkypr
|
Why does your lower back/buttocks get that tingle when looking down from extreme heights?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq2tegf"
],
"text": [
"I get it in my feet. Very weird, and only heights does it. Didn’t used to either - when I was a youngster I loved climbing and heights."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzl9yn
|
Why does task manager close stuff so much faster than normal closing methods?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"gq2r57p",
"gq2ssy4",
"gq2r4kz"
],
"text": [
"When you use the normal method to close a program it's going to close that program from within the program itself and it's going to run very specific code. For example, in a video game if you were to close it the developer might make it so that you also autosave before it closes. And if it's poorly programmed it might do a ton of other stuff before it even registers that you told it to close. When you use task manager windows kills the application and says to hell with all that extra crap.",
"The red `X` (or `alt-f4`) don't actually close the application. Instead, it sends a signal to the application - roughly similar to pressing a keyboard key. The application will usually then exit, but it doesn't have to. By contrast, Task Manager actually closes the program directly and immediately, bypassing its code altogether.",
"Closing a program normally lets a program finish what it's doing, and close on it's own time. So if you close Word without saving, it has the chance to say \"hey, do you want to save before closing?\" Task manager takes away all the resources the program was working with, immediately killing the program without it being able to respond"
],
"score": [
11,
5,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzm7gr
|
What happens when a person gets liposuction in every area of their body? Would they remain thin forever (regardless of how much food they eat?) Or would fat still redistribute?
|
Biology
|
explainlikeimfive
|
{
"a_id": [
"gq2w6ib"
],
"text": [
"A problem that they've discovered with liposuction is that it is *substantially* more unhealthy to get it done than to just be fat. Fat is acidic and causes damage to cells. Ordinarily this isn't a problem because your body stores fat in special cells that are equipped to neutralize the fat's acidity. When you get liposuction what you're doing is removing most of those cells without removing the underlying cause of the problem (the fact that you're overeating). Your body doesn't just stop making fat but when there are no specialized fat cells to soak it up then your body's normal cells begin soaking it up. They're not equipped to handle the acidity of fat and eventually die from it. This is actually what causes obesity related diabetes. Under normal conditions your pancreas will not store fat. But when you're morbidly obese it begins to do so. The acidity of that fat eventually kills the insulin producing cells in your pancreas and then you get type 2 diabetes. When you get liposuction all you're really doing is speeding that process up because now your pancreas is storing fat under normal conditions since the fat has nowhere else to go. After your pancreas dies off that fat begins getting shunted into your liver. You then develop fatty liver disease which eventually leads to liver failure, at which point you die. In short, what happens if you liposuction all of the fat out of your body is that your pancreas and liver swell up with fat and that causes some fairly horrible medical problems with an associated reduction in your life expectancy."
],
"score": [
124
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
lzp7gx
|
Why do most goods have relatively stable prices, while gasoline fluctuates on a daily basis?
|
Economics
|
explainlikeimfive
|
{
"a_id": [
"gq39aoh",
"gq3iksn",
"gq48mij",
"gq3paad",
"gq3a8w8"
],
"text": [
"Mostly because gasstations decided it's worth the effort to inform people of daily price changes. Fuel supply and demand change a lot, so with a constant price it would have to be pretty high to prevent the risk of selling at a loss for gasstations. With other goods supply and demand are very stable, and the effort to inform people about the daily price outweights the gains for the seller. (Imagine a grocery store would keep up some digital board with all the current daily vegetable rates instead of printing a pricetag)",
"on most other good you are mostly confident that the supply remains stable as long as you know the producers are providing. for gas the issue is that there a lot less stability in the supply of Oil vs the demand for fuel and some of the locations that have reserves might have political issues that could cut off access to them. this makes trading for Oil more volatile of a market.",
"One of the key factors not previously mentioned is that gas stations run on super thin margins. While a carrot is typically marked up by 100%, so a 5% change in cost is no big deal for the reseller, gasoline is marked up by 5-10%, so a 5% change in cost might wipe out the profit altogether. Also, gas stations absolutely change prices through the day based on demand. The price of gas absolutely increases during rush hour. When your margins are razor thin, you need to use every possible advantage. Source: investigated buying a gas station.",
"This is obviously not true of many stations, but I know the manager of one next to a Walmart Supercenter. Because of the enormous volume of gas he pumps, he gets a tanker every day; sometimes two. He may be changing his prices to match each truck.",
"There are many factors to consider here - is it producable, is it flammable or perishable, storage (size) costs to selling cost ratio, shipping (weight, flammability, etc) costs to selling cost ratio, demand and supply ratio, etc. Gasoline isn't producable, we can only extract what earth already has. It is flammable, which means it has a risk factor. During quarantine period, demand was 0 so the prices were in negative (they were paying us, to take the barrels) which means it was more expensive for them to store it than to simply give it away (storage cost to selling cost ratio). If a ship full of gasoline sinks, ship gone, gasoline gone, underwater life gone, too much loss, lack of supply, increase in price. There are many other factors, for eg sometimes industries keep goods hidden (decreasing the supply) so that prices will rise and then they can sell the hidden stock at increased price. You can check these factors for any type of goods and figure how they work. PS: I'm not in the profession so please ignore if I'm using wrong words. I'm just putting it in layman's terms."
],
"score": [
35,
7,
6,
5,
4
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.