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
|
|---|---|---|---|---|---|---|---|
7ji33o | What causes that awful feeling that makes your entire leg jolt when someone squeezes the area just above your knee? | Biology | explainlikeimfive | {
"a_id": [
"dr6knwz"
],
"text": [
"Knee jerk reflex! The act of hitting/squeezing the fibres causes stretching of them, which sends out a nerve signal to your spinal cord. Here the message splits, with an ascending pathway to the brain and also a nerve which returns straight to the muscle (without going to the brain at all). This nerve sends a signal to the muscle to contract, causing the leg to swing out a little. Its designed to prevent over-stretching of the muscle, and also occurs naturally quite often."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7ji69c | The number of videos on YouTube is vast. Is there any risk of losing this data? What would need to happen for data loss to occur? | Technology | explainlikeimfive | {
"a_id": [
"dr6jzq2",
"dr6jwuw"
],
"text": [
"The data is almost certainly duplicated/spread across multiple drives and multiple datacentre locations, with more frequently accessed data (popular videos) spread even more so that more people can read that data at once. I haven't read any specifics on Youtube but I expect their data redundancy is top notch. It could still be lost, but the chances are low. If the data is only on a single drive, then all it takes is for that drive to fail and then the data is lost. This is why Youtube will spread the data across multiple drives. But something could still go wrong in that specific physical location that causes the loss of multiple drives, so mirroring the data to other data-centres across the world helps mitigate that risk as well. It would be particularly unfortunate and unlikely if every single piece of data relevant to the file were all lost at the same time. A different possibility for data-loss that should also be considered is that Youtube could decide to purposefully get rid of certain particularly old/low value content at some point in order to save costs. I think it is prudent to keep a copy of very important data yourself and not 100% rely on online storage.",
"The data is replicated amongst a vast amount of servers so the only risk of data loss at a noticeable scale will require server failures at multiple locations at once. Basically they keep copies of their eggs in many baskets."
],
"score": [
10,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jidph | How do you read a sports betting "spread" line? | I know how to read a moneyline, but I can't seem to figure out how to read a spread line. I have no actual interest in gambling but I just like to look at the odds for the upcoming games each week. [This]( URL_0 ) is a very common sports. For example, the Jets-Saints line has 4 numbers: .|.|. :--:|:--|:-- NY Jets|47u|-10 NO Saints|-15 1/2|+05 The Cardinals-Redskins line has 4 numbers: .|.|. :--:|:--|:-- Arizona|44u|-10 Washington|-3 1/2|-05 what do these numbers mean???? | Other | explainlikeimfive | {
"a_id": [
"dr6umzb"
],
"text": [
"The \"u\" is for under. The number in front of the \"u\" indicates the total score between the two teams. So in the first example, you are betting that the end score will be under 47 points. You can bet the over as well. If you think the Jets will score 30 and the Saints will score 20, the total is 50. Since this is over the offered 47 points, you should bet the \"over\". & nbsp; The number under that is the spread. In the same example, the Saints are a much better team than the Jets. It wouldn't make sense for a bookie to offer that game straight up, as everyone would bet on the Saints and the bookie will most likely lose a lot of money. So instead, they offer a spread. The \"-\" indicates they are the favorite, because the way it's calculated is that you will take the Saints score at the end and \"-\" 15.5 points from it. If they still beat the Jets, you will win your bet. So take the example from my previous paragraph. If the Saints score 30 and the Jets score 20, you will lose the bet. You would take the Saints' score and subtract 15.5 (30-15.5=14.5). Since the Jets scored 20, they would beat the adjusted Saints score of 14.5. The opposite of this would be Jets +15.5. It means the same thing but money lines prefer to list the favorites. & nbsp; Being a bookie, ideally is a guaranteed moneymaker. Their strategy is to get their clients to split the bets. They want 50% of their clients to bet on the Saints and 50% of their clients to bet on the Jets. That way, they're guaranteed to make money. The losers pay them the full amount of the bet but the winners don't receive the full amount because the bookie takes a commission (usually around 10%). This is why you'll see the line adjust throughout the week. This is to try and balance the bets. If the bookie made the line Saints -20, many people would bet the Jets. When the bookie realizes this, he will move the line down to Saints -19 to try and get people to bet on the Saints. The adjustment will continue until it's as close to a 50/50 split as possible."
],
"score": [
4
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jijga | Why do they offer 2for1 or a reduced price on food that isn't going to expire anytime soon. | Other | explainlikeimfive | {
"a_id": [
"dr6lw8s"
],
"text": [
"Depends on the circumstances. They could need to clear out inventory or shelf space for something else, for example. Or they could be trying to boost sales in the short term by selling on volume instead of margin. Or in some cases the sale price is their intended margin, and by putting a fake sale they hope that you'll buy more of it. The answer is that it could be a bunch of things driving that decision."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jimdp | Why must phones be turned off at gasoline stations? | Also, why do people ignore this warning ? edit: before posting, I searched reddit for the answer to my question but got nothing. However when I did a google search, a number of posts similar to mine popped up. I checked them out and found out that they were a few years old. Now I'm wondering if today's answers would be any different to a few years ago. | Technology | explainlikeimfive | {
"a_id": [
"dr6mzl4",
"dr72giv",
"dr6nmwh",
"dr7637i",
"dr6n8fj",
"dr75j6t"
],
"text": [
"There was a fear of exploding cellphone batteries igniting the gas fumes. Most people ignore it because the chance of it happening is actually quite low.",
"The cell phone causing a fire is a common myth. Every time this question gets asked people point out the myth busters episode. Cell phone and their lithium battery catching on fire is a fairly rare event. The biggest risk with a cell phone is driver inattention. Walking into moving cars, forgetting the nozzle is in the car and driving off, snapping the breakaway on the hose.",
"It started off years ago when cell phones were quite new. It coincided with some explosions at gas stations where the causes weren't 100% certain. One possible cause was electrical discharge from phones, and since the equipment was new and coincided with the rise in explosions they were banned. None of the incidents have been proven to be due to cell phones however. They also noticed that the overwhelming number of cases were in the US. US is/was pretty unique in that you don't have to hold the pump the whole time. It turned out the biggest risk was static electricity due to people sitting down in the car while the car continues to fill. By then laws had been passed and gas stations were restricting the cell phones. That makes it nigh on impossible to remove the rules when there remains a theoretical risk of a cell phone causing the same damage.",
"Gas stations that used to have no cell phone warnings at the pump, that I frequent, have removed them. It was essentially a hoax. Its virtually impossible for a spark from your phone to ignite gas vapors in the air. URL_1 Mythbusters tried, really really hard to make it happen, and couldn't. URL_2 URL_0",
"I don't think it is as big of an issue as it used to be. But the issue is that a static electricity shock can ignite the fumes. The same reason you aren't supposed to get back in the car while fueling.",
"People once believed (and often still do) that there was a possibility they could ignite gas fumes. Cell phones might be ubiquitous now, but in the 1990s they were almost magic, and people believed a lot of silly things about them. It is theoretically possible for this to happen, but gas fumes are much, much more like to be ignited by a hot engine or a faulty connection than by a phone."
],
"score": [
18,
8,
6,
5,
4,
4
],
"text_urls": [
[],
[],
[],
[
"http://www.slate.com/blogs/business_insider/2014/10/03/cellphones_at_gas_stations_mythbusters_debunk_one_of_the_biggest_myths_in.html",
"https://www.snopes.com/autos/hazards/gasvapor.asp",
"https://www.discovery.com/tv-shows/mythbusters/videos/cell-phone-gas-station-minimyth"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jiorv | Can you guys educate/explain me better differentiation and integration? | Mathematics | explainlikeimfive | {
"a_id": [
"dr6oavk"
],
"text": [
"Differentiation gives you the _rate of change_ of something. Integration gives you _something_ based on its rate of change. Just when I started pre-calculus, I mentally used acceleration and velocity to help myself understand these concepts better. Acceleration is the _rate of change_ of speed (with respect to time), so that means it's actually the derivative of velocity. In math symbolism: a = dv/dt ([a] - acceleration, [v] - velocity, [t] - time). Integration, on the other hand, could give you the velocity based on acceleration."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jirni | Why do girls mature faster than boys? What is the biological process that makes this happen and what purpose does it serve? | Biology | explainlikeimfive | {
"a_id": [
"dr6ncf1",
"dr6nw1e",
"dr6ngdc"
],
"text": [
"well if you think about human progression over a few thousand years, most humans most likely came from woman who had kids as soon as they were biologically able. So if you could have more kids earlier on, the more genetics you have in the population. so for human survival, having the early maturity trait was pretty important",
"Part of it is dependant on where and how they live. Having a safe place to live and plenty of food encourages earlier development in females. It's important that we grow children inside us while we have a reliable supply of food. Childbirth is still the most dangerous thing that women (some would argue humans) ever do. Got to be fit to do that. If food is scarce, female children develop later. Some places they don't start to menstruate until their 20's On the other hand, a hungry, dangerous environment encourages boys to develop faster. It only takes a few minutes for a boy to pass on his genes. In some high-risk areas, boys can reach puberty as early as 7. Explained to me by a librarian in my friend group after she went out and researched it.",
"It would seem plausible that women who give birth to children at a young age have throughout history failed with greater regularity to pass on their genes successfully if they were irresponsible or non-serious about their actions. Men on the other hand may have more easily got away with passing on their risky immature genes by having a sensible lady friend to procreate with, due in part to the huge disparity between the minimum amount of time required of men and women in making another human being. 9 months vs.... a much shorter time."
],
"score": [
12,
8,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jiwsx | How do lumens and watts relate in lightbulbs? | I just moved out of my parents home at the tender age of 19 so forgive my total ignorance. I bought a lamp that said it needs an E27 400 lumen bulb. I went to get a light bulb for it at a different store (first mistake) and most bulbs only said their wattage, not lumen, and the closest was 350 lumens or 850 lumens. I know lumen is brightness and watt is amount of electrical power needed. I don't know how the two relate, or how to choose the correct watt to suit the lumen. Google told me 400 lumen was equal to 40 watt, but most of the lightbulbs at the store were 8 watt. My friend's advice was just to make sure the number on the bulb wasn't higher than the recommended number or it might blow. Can someone please explain how lumen relates to watt? Can I have a brighter than recommended lumen as long as the watt isn't higher? How do I know what the lamps wattage is since the box didn't say? | Physics | explainlikeimfive | {
"a_id": [
"dr6q3xk",
"dr6otph"
],
"text": [
"They don't relate as well as you'd hope. Back in the days of just incandescent bulbs a 40W bulb gave you 400ish lumens, unfortunately things have changed. The incandescent bulbs you find today are halogen and more efficient so they're only 32W for 400 lumens. With LEDs you only need 5-9W depending on the tech in the bulb Really what your lamp cares about is wattage. A 40W incandescent bulb would give off 39W of heat, and a 60W would give off 59. If you put too big of a bulb in then the lamp would overheat and run the risk of fire. These days bulbs are a lot more efficient. You can put any LED you want in there and it won't overheat. You might blind yourself but it won't overheat",
"Lumen is a measure of brightness and watt is a measure of power. With incandescent bulbs, the amount of power used was a good proxy for brightness of the bulb, so they used watts. For this reason, all the old bulbs and lamps had power written in wattage. With the newer bulbs (LED and CFL), wattage is no longer a good proxy because the wattage has decreased due to new technology. So for these new bulbs the standard is lumens. You can find charts on google to approximate lumens to watts for the incandescent bulb standard. For newer bulbs, you should look at the lumens rather than the wattage. Putting a slightly brighter or darker bulb into a 500 lumen lamp should not be a big deal as most lamps are designed to allow you some variability with the brightness of the bulb."
],
"score": [
4,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jj1aq | dialectics/dialectical materialism | Google has yet to provide a clear answer | Economics | explainlikeimfive | {
"a_id": [
"dr6po47"
],
"text": [
"Dialectic materialism is a model put forth by Karl Marx and Friedrich Engels. It is a counterproposal to the idealistic dialectic as used by G.W.F Hegel and Immanuel Kant. Idealism asserts that reality, or reality as humans can know it, is fundamentally mental, mentally constructed, or otherwise immaterial. Marx, on the other hand interpreted history as the history of contradictions arising from material surroundings of individuals. The dialectic solution of those contradictions was the source of progress. For example, the material changes in French society in the 15th-18th century lead to the existence of the bourgeoisie, or the third estate. As cities grew larger, religion grew less important and the divine right to rule of the first and third estate was no longer enough to legitimize the power of the feudal ruling demographic. Thus, the third estate grew to be the de-facto defining factor in society. However, the formal structures were still relics of the feudal rule of bygone centuries. This situation was a contradiction between the mass of the population and the feudal rulers - rooted in the material and economic circumstances. The bourgeois had the objective hegemony in society, but was not yet subjectively actualized. Thus, this contradiction was resolved in the French Revolution of 1789, where the feudal ruling class was expelled and the bourgeois society could be actualized."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jj2ci | Is there any actual benefit of the increase in funding of the US military? | Economics | explainlikeimfive | {
"a_id": [
"dr6paxq"
],
"text": [
"Increases in US military spending are a form of campaign finance quid pro quo where tax dollars are used to repay campaign contributions from military contractors once elected to office. US military spending never translates to better standards of living or levels of compensation for members of the military."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jj6qi | How do Colleges/Universities schedule hundreds of exams without any overlapping in a students schedule. | Other | explainlikeimfive | {
"a_id": [
"dr6qx07"
],
"text": [
"It's tied to how their schedule was set for the classes that you can take. If Course A and Course B are both scheduled for 10AM on Tuesdays, then we can assume that no one is doing both classes. Then there are courses that can only be taken by students in a certain Major or Faculty, so they don't need to worry about some final year math course and some final year psychology course. Continue that trend till you have a set exam schedule, then go over it taking into account that there may be edge cases where some students were allowed to take Course A and Course B. Some institutions would release a draft and have students report and overlapping exams just in case administration ends up missing it."
],
"score": [
10
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jk2bd | How do we 'get used to' a smell and no longer notice it? | Biology | explainlikeimfive | {
"a_id": [
"dr6y90z",
"dr6xtg4"
],
"text": [
"As other people have said, your brain filters it out. To add on to this though, your brain does this with lots of other things too. Your nose is in the middle of your vision at all times. Your brain \"patches\" the processed image you see to filter out your nose. Your brain also filters out white noise from your ears all the time.",
"Your brain has only so much processing power and it needs to quickly make a determination if something is a threat or not (first priority) or a benefit or not. Once something becomes familiar the brain puts it into the not a threat category and continues scanning through all of the sensory input looking something that might eat/squish/poison you. Things that are of no benefit, do not produce a specific satisfaction, and are of no threat simply aren't forwarded up the chain to your higher levels of brain function because you aren't going to do anything with them."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jkfx0 | Why aren't noise cancelling headphones as effective in cancelling high pitch sounds as their in cancelling low pitch sounds? | Technology | explainlikeimfive | {
"a_id": [
"dr76h0o",
"dr8cpbh",
"dr7ifya",
"dr7tspr",
"dr7sj3u"
],
"text": [
"The way noise cancelling works is that it has a microphone pick up some noise and then a speaker produce that noise phase shifted 180 degrees. The resulting waveforms precisely cancel out. However, the microphone can only pick up the noise as it's passing by and there's a delay before it can generate the phase-shifted sound. This means that you have to 'guess' what the future will hold in some sense. High frequency waves embed more information and shift more often, meaning it's a lot harder to make guesses about them than low frequency waves.",
"_Actual ELI5_ Have you ever tried clapping opposite to someone else? I mean clapping exactly when the other person has their hands apart, getting your hands apart when they clap? It's really hard to do. You can usually only do it when the other person (or, worse, crowd) is clapping pretty slowly. When they're clapping very fast, or there's a lot of them clapping not-exactly-in-sync, it gets quite a bit harder. Noise cancelling headphones try to do exactly this but with sound waves. Lower frequency sounds _clap_ slower and are easier to predict. Higher frequency sounds _clap_ faster and are harder to predict.",
"Low frequency sound waves are generally transmitted better than higher frequency sound waves due to several reasons: (1) Better diffraction, since lower frequency sound means longer wavelengths and longer waves bend more easily around obstacles and have more ways to reach their destination, (2) The human ear is most sensitive to frequencies around 2-2.5KHz, but when it comes to lower frequencies, the ear is not the only thing receiving the sound. Bones and organs can also feel the vibrations of a low freq sound (ultra heavy bass may even interfere with the working of the heart), (3) majority of songs have bass frequencies boosted. Since the ear is most sensitive to 2-2.5KHz sound, the lower frequencies need extra energy (i.e. higher amplitude) for their bass to be perceived \"adequately\" (and what is perceived as adequate bass today is most definitely more powerful than adequate bass 50 years ago).",
"Low frequencies are more spatially uniform due to their longer wavelength. They travel through most materials without reflection * * , and reflected waves interfere on a much larger scale than that of your head or ear * * *. If you ever listened to a pure high frequency sound, you know that moving your head even a few millimeters can change the intensity due to wave effects. So using a microphone to pick up the sound, and then invert and send to your ear is much less useful. The sound at the microphone is not exactly the sound you hear inside the ear, and even the sound created by the headphone is not as predictable and will generate some noise instead of canceling it. ** This is why low frequency sounds are so hard to remove, from the cabin of an airplane, for instance. It passes through the sound deadening materials. *** This is why a subwofer can be anywhere in a room - your ear gets no directional information by moving around or reflections.",
"The simple answer is because that's what they were originally invented for, engine noise. A better answer involves math. Noise cancelling headphones work by adding \"negative sound\", sound that is 180° out of phase. So let's assume that the noise cancelling headphones have only one microphone and it's located at the same place as the speaker, about a centimeter from your ear, and we'll ignore the passive effects of the headphones and your ears, just treat them both as points. Ideally, the sound and \"negative sound\" reach your ear together, 180° out of phase. 2cos(180°/2) = 0 no sound. First, let's ignore time and consider direction. If the sound wavefront comes in inline with the headphone a your ear, then there's a 1cm difference between the headphone and the ear. If it comes in at a 45° angle, there's only a 0.7cm difference, but the \"negative sound\" still has to travel the whole 1 cm because it's coming from the headphone. At 200hz that 0.3cm difference is a 0.6° difference, basically nothing, but at 2000Hz its a 6° still tiny but 10 times less tiny. Now assume there is a 0.1ms delay between the headphones hearing the sound and producing the \"negative sound\". At 200Hz this leads to a 7.2° lag. 2cos(187.2°/2) = -0.126 a 87.4% reduction, pretty quiet. At 2000Hz however, that 0.1ms is a 72° lag. 2cos(252°/2) = -1.175 the headphones are so far from their intended phase that they're actually making the sound 17% louder. That 10x difference in lag let to a more than 10x difference in noise reduction because the cosine function is non linear. TLDR at higher frequencies, small errors make bigger differences."
],
"score": [
703,
28,
14,
8,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jko89 | why putting sharp pressure on/pinching certain parts of the face or forehead triggers the urge to sneeze? | Biology | explainlikeimfive | {
"a_id": [
"dr726j8"
],
"text": [
"There is one major nerve servicing your face. Many things can trigger a response your brain can't understand (bright sudden light for example, or very flavorful food). Basically a wierd signal from one nerve ending sets off a chain reaction your brain interprets as a sneeze signal. The survival benefit is that sneezing will remove most things grabbed to your face. So if something was legitimately ripping nose hairs out your face the sneeze dislodged it, and if it's anything less serious, well, didn't hurt your survival chances to sneeze"
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jkt0z | Why do you get the feeling you need to puke when you stick your finger deep in your mouth, even though your finger isn't touching anything? | Biology | explainlikeimfive | {
"a_id": [
"dr74f3n"
],
"text": [
"This is the gag reflex, a.k.a. the \"pharyngeal reflex\": it's actually the throat closing to prevent something too large from going down and causing a blockage, but sometimes it may also make you want to vomit. You almost certainly are touching something, though. It might be the back of the tongue or the roof of the mouth, especially in the area near the back of the mouth; but if it doesn't feel as if you're touching anything, then it's probably the uvula. This is the weird thing that hangs down at the back of the mouth. This functions partly to help close off the mouth when you swallow so that food doesn't get into your nose, and partly to detect when you're trying to swallow something that you might choke on."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jkx5v | How does your mind choses random numbers when someone asks you to do it? | Biology | explainlikeimfive | {
"a_id": [
"dr7a2tq",
"dr7avu3",
"dr7bb9q",
"dr7ehv3",
"dr7dtv6",
"dr7d622"
],
"text": [
"A simple way to put it is this. You are put into a panic so you try to think of the most random number. Here is an example, from 1 to 10. 1 or 10 are the extremes and we’re just stated so that isn’t random enough. Even numbers are out because their even, and not Odd, needs to be odd to be random. 3,5,7,9 are left. 5 is in the middle, 3’s too low and 9 is too close to 10. 7.",
"It doesn't really, it just chooses numbers it thinks are random, and it does a pretty poor job at it. It usually starts by picking an unround number towards the middle of the range, with a bias away from numbers ending in 0 or 5 and towards odd numbers. Then it is a game of \"what haven't I done recently\", alternating between even and odd, high and low, cycling through digits you haven't used recently and picking numbers in the spaces between those you have already picked. The result is going to be decidedly unrandom, to the point a forensic accountant can pretty easily tell when someone is just making up figures.",
"You can test this by saying “random” numbers as fast as you can. After a few seconds they aren’t random anymore.",
"The human mind isn't capable of intentional randomness. The best it can accomplish is arbitrary decisions.",
"There is a concept known as [priming]( URL_0 ) where observing something, consciously or subconsciously, brings it closer to the front of your mind. For a little anecdotal evidence, the first number I thought of was 23. I noticed going back to the ELI5 front page, there was a post that had a score of 23 points. That subliminal number that I did not notice at first very well could have influenced me. In rock-paper-scissors, there are certain \"tells\" that are based on priming. For instance, from watching a competition, one of these tells they mentioned was that short-haired women are more likely to pick scissors, having seen more than their fair share of them.",
"whenwver i try to think of random numbers i start out fine and then end up counting down from 4 or 5"
],
"score": [
258,
252,
14,
5,
5,
4
],
"text_urls": [
[],
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Priming_(psychology\\)"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jl14o | How do game developers link between graphics and code? | Technology | explainlikeimfive | {
"a_id": [
"dr79vda"
],
"text": [
"This is a massively complex question for which any answer suitable for ELI5 isn't really going to do justice to the substance of the subject matter. Think of the graphics engine in a game as a machine that builds Lego sets on demand. When given the instructions to build a set, it will throw out the set it just built and build a new set from scratch, which it can do dozens of times per second. In order to do this, the machine has access to a massive, well-organized Lego collection. This collection has an infinite *number* of blocks, but a defined, finite number of *kinds* of blocks. In other words, you only have so many different kinds of blocks, but you have as many of each of those kinds as you need. The way this metaphor works is that the frames displayed on your screen are \"Lego sets,\" and the \"Lego blocks\" are the game's \"art assets\", i.e., files saved on your hard drive that can be invoked on an as-needed basis. As the game displays frames (i.e., builds new Lego sets), it's programmed to invoke specific art assets under specific conditions and with specific parameters (i.e., pick the right blocks from the collection). One of the big tricks is changing those conditions and parameters as your perspective changes, whether that's simply moving your most or walking around the map. But that programming will basically tell the graphics engine what art assets to invoke and under what terms they should be handled (i.e., write instructions for new Lego sets on the fly). Any explanation much more technical than that is going to involve too much detail for ELI5."
],
"score": [
20
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jl4qn | Why is it harder to paint something that is black than something that is white? | I think it has to do something with the absorption of light but I can't figure out how. | Physics | explainlikeimfive | {
"a_id": [
"dr76bm9"
],
"text": [
"It's usually less about absorption and more about the transparency of the paint. Black is almost always a very opaque colour. White is frequently more translucent than opaque. In general, darker colours (your strong reds, blues, greens, browns) tend to be less translucent than lighter colours. So, dark colours are more likely to show through lighter colours than the other way around. From my own experience, oil-based paints and acrylic paints don't usually have that quality unless you water them down quite a bit."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jldng | Why do we have to swallow to drink liquid, instead of being able to just pour it directly down the esophagus like pouring water down a tube? | Biology | explainlikeimfive | {
"a_id": [
"dr78m9l"
],
"text": [
"The human esophagus (food tube) and trachea (air tube) are connected. There's a muscle response for closing one and opening the other. Usually the air tube is open, and the food tube is closed. To open the food tube, the air tube must close (go ahead and try to inhale while you swallow, it's not possible). This (usually) protects you from accidentally inhaling food/drink and damaging your lungs, and enables us to talk. Some animals aren't arranged that way, and can just pour food down like a crocodile."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jlhdz | How does the Google Maps 'Popular Times' feature work? | They have this feature even for the smallest shop in the World, but how does it actually work? | Technology | explainlikeimfive | {
"a_id": [
"dr797q7"
],
"text": [
"billions of android devices all send geolocation data back to Google. if lots of devices are in the area of the shop, then it's an indicator it's busy at that time of day."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jlmxu | how do allosteric inhibitors "change the shape" of the site of reaction in an enzyme | Biology | explainlikeimfive | {
"a_id": [
"dr7hl0w"
],
"text": [
"Enzymes, and proteins in general, are really just sequences of smaller molecular units called amino acids. They are stitched together into a straight chain, and then the chain is folded together to do whatever the protein needs to do This folding happens because each amino acid, although similar in shape, is different enough in their composition that they have different structural and chemical properties. Proline is unbending, glutamic acid is negatively charged, lysine is positively charged, etc. And these properties determine how the protein looks in the end Allosteric inhibitors also have their own properties, chemical and physical. When they interact with the protein in question, they can make use of the amino acids' natural properties and disrupt the folding pattern of the whole protein. Because the folding is determined by effectively all the amino acids, changing how some amino acids contribute can change all the way to the active site Example: putting two cysteine amino acids close together can form what we call a disulfide bond, which is a really strong connection that is hard to break. If an inhibitor has something that connects even better to cysteine, it can break the bond and cause the protein at that point to unravel"
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jlqpu | Why did prohibition come in the form of a constitutional amendment as opposed to just a 'normal law'? | Other | explainlikeimfive | {
"a_id": [
"dr7cy4x",
"dr7bff5"
],
"text": [
"Under the Constitution, the federal government could not have forbidden the sale of alcohol that was produced, sold, distributed, and consumed entirely within the borders of one state, as the Constitution grants the federal government the right to regulate interstate commerce only. The Prohibitionists didn't want alcohol to be sold even if it were produced under those conditions, and they couldn't rely on every state passing a law to ban it within their borders. Additionally, if the federal government had found a way to pass a law that somehow met the requirements under the Constitution at the time, it would almost certainly be immediately challenged in court, potentially stayed (meaning its enforcement would be withheld), and even possibly struck down. They didn't want any of that to happen either. (Note that more recent Constitutional case law has expanded the interpretation of the Commerce Clause considerably; it'd be easier to do now with regular federal law, though it would still be easy to challenge in court and be struck down.)",
"They could have passed it as a normal law, but they wanted it to be really hard to undo. Amending the constitution (and likewise repealing an amendment) requires higher majorities in both houses of Congress plus the approval of 3/4 of the states."
],
"score": [
7,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jlvx7 | Why sea waves can never be from land to sea? | We also learnt in geography class in the night time wind blows from land to sea. So i always thought wind makes waves and they are in same direction. | Other | explainlikeimfive | {
"a_id": [
"dr7g7sr"
],
"text": [
"The wind has to rub against the water for some distance to make waves. So when the wind is heading from land to sea, it *might* create waves heading that way, but they won't appear until far offshore, where the wind has had some room to do its work. Meanwhile, waves created far away and headed toward you (on shore) will continue to arrive. Interestingly, sets of waves going in opposite or different directions can actually cross without canceling each other out. Both sets keep going."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jlvz3 | What makes foods like ginger a palate cleanser? | Biology | explainlikeimfive | {
"a_id": [
"dr7tm5i",
"dr88a29"
],
"text": [
"The vinegar. Acidic substances without much in the way of flavor, such as vinegar, help to reduce or remove food particles from the mouth and tongue. Pickled ginger works well as a palate cleanser due to containing vinegar and because ginger does not leave behind very many food particles.",
"Fun fact: ginger acts as a bacterial fighting agent in your stomach, hence why it is served with raw fish."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jlzpa | Why is it considered dangerous to reheat rice yet it's safe to have in ready meals? | Other | explainlikeimfive | {
"a_id": [
"dr7fcpt",
"dr7r0o8",
"dr7dpjn",
"dr7e20d",
"dr7ottd",
"dr7rgaw",
"dr7rz9o",
"dr7myee",
"dr7x5gd",
"dr7xhu8",
"dr7tzb0",
"dr7tbzd",
"dr7xwqn",
"dr7sq9q",
"dr7zdt2",
"dr7t27v",
"dr7w9dj",
"dr7u2eg",
"dr7u7za",
"dr7uwe5",
"dr7se4u",
"dr7up6w",
"dr7uq0a"
],
"text": [
"The reheating isn't the dangerous part. The danger comes from leaving cooked rice out, unrefrigerated and unheated, for many hours. In this \"danger zone\" temperature, microorganisms can grow in it that can make you sick.",
"The bacterium is called Baccillus Cereus and it secretes a toxin which makes you puke and have the shits for 3-7 days. Reheating rice properly will kill the bacteria but doesn't breakdown the toxin. *Source: Personal experience with a reheated Chinese takeaway and postgrad scientist.",
"Ready meals are typically precooked or freeze dried. This kills bacteria and other things potentially harmful to your health. It's absolutely fine to reheat rice at home if you freeze it right after you make it, but the longer it sits on the counter, the more bacteria grow. All food is this way. To be frank, though, reheating the rice that you left in your rice cooker/pot all night isn't really an issue.",
"Its all to do with the presence of the ergot toxin producing fungus. If you leave rice out it can produce dangerously high levels of the toxin. Reheating rice that has been immediately put in the fridge runs pretty much no risk of ergot production. With ready meals, they would have been frozen/refrigerated almost immediately after production so it is safe to eat. But yeah its quite unlikely to be present in the first place, a little bit like salmonella on chicken.. you obviously don't eat it raw because of the risk.",
"Pshhh all these non-rice eaters talking nonsense... Next thing you know is that they're gonna try to say that vaccines cause autism or something... jk. you're leaving something moist in a closed container out in the open, what do you expect? lol If you leave it out in the open, there's a higher chance of the rice drying out before it becomes moldy. It takes at least 18 hours out in the open in my experience before you should probably just make a new batch... But if you wait that long before you consider wrapping it and putting it in the fridge, you should probably practice cleaning up and putting things away when you are done cooking/eating.",
"In particular, there's a bacteria called bacillus cereus that's infamous for dying during the initial heating of rice but having its much more resilient spores survive and infect when eating the second time around. Source - med school (and in reality, First Aid)",
"It's common for an organism called Bacillus cereus to contaminate rice. This is a hardy little bug that can produce protective spores that allow it to survive some cooking processes (around 100C). If spores survive and food is improperly refrigerated the spores will germinate and rapidly multiply at room temperature. This rapid growth phase releases toxins that are again stable at the temperatures used to reheat rice, and so cause food poisoning after ingestion. The reason ready meals are safeis because they were either sterilised during processing, or they require cooking methods that reach sufficient temperatures to denatured toxins and kill spores (such as 200C ovens or 10+ minutes of microwaving). Source: microbiologist",
"First I’m hearing about this. I have always assumed rice was hella safe no matter what you did with it. I have eaten fried rice leftovers that have been sitting on counter for god knows how long , have reheated rice tons of times, still alive, should I be ded?",
"Um...I am Chinese and I have never heard of any such thing. but rice left in the fridge uncovered is a bad idea. rice absorb the smell and other odors so the rice would taste awful and be bad for you. so don't put it next to raw stuff and put it in an air seal thingy you have on hand. also it is best to make a stir fry with leftover rice cause reheat rice taste awful.",
"This is pretty mind blowing from someone who's eaten rice his entire life. Sometimes I don't even reheat it",
"What, I had no idea this could get you sick. I've literally been eating this way for over 20+ years!",
"Ummmmm, who told you it's dangerous to reheat rice? I've eaten Chinese food for like a week after ordering it.",
"as a filipino who eats rice breakfast,lunch and dinner all i can say is.. what the fuck is this? when did rice became dangerous to reheat??? i mean, leftover steamed rice,even a day old as long as it hasnt soured yet, actually are the perfect rice to make fried rice in this part of the world.",
"Copy pasta: Uncooked rice can contain spores of Bacillus cereus, a bacterium that can cause food poisoning. The spores can survive when rice is cooked. If rice is left standing at room temperature, the spores can grow into bacteria. These bacteria will multiply and may produce toxins (poisons) that cause vomiting or diarrhoea. The longer cooked rice is left at room temperature, the more likely it is that the bacteria or toxins could make the rice unsafe to eat. URL_0",
"Do people not refrigerate their rice? I’m genuinely astonished.",
"I’m constantly cooking rice and leaving it out overnight. I’ll even eat the leftovers the next morning without heating them.... Does this mean I’m dead?",
"South Asian here. Never heard of this. We cook rice for lunch, and if there's any leftovers, keep it outside until next morning, reheat it and have it for breakfast. Have done this so many times and had no problems whatsoever. Has it got something to do with how we cook the rice? Do people in the west cook it differently?",
"It's never happened to me before or anyone I have cooked for and I couldn't be more negligent with my handling of leftover rice.",
"If you can leave a Meat Lover's pizza from Pizza Hut on the counter overnight and have it for breakfast, cold, I don't think rice could be any worse. Now that I think about it, maybe it's not actual meat?",
"Huh, never heard about this. I come from a Chinese family and we eat rice almost daily. A lot of times we just leave the leftover rice in the rice cooker overnight and finish it up the following day after reheating it.",
"This is so odd to me, because I have this weird love for cold rice and love it after its about a few hours cold. Ive even eaten it the next morning. Im thinking my stomach is probably used to it... I dont suggest others do this",
"Bacillus cereus Basically these little fuckers form spores that commonly find their way in with raw rice grains. The spores are very hardy and survive the cooking process, then actually end up germinating afterward while the rice is nice and warm. You can reheat the rice and kill them, but one of the toxins they produce while they were alive is heat stable, so it sticks around anyway. This results in what is called intoxication (not the alcohol variety). What follows is usually some serious vomiting as that toxin sets off your body's defenses against what it considers poison. That bring said, I eat reheated rice all the time.",
"In the morning I take my food out of the fridge and don't bother to put it in the fridge at work usually, and reheat it for lunch. Chicken, beef, rice, pasta, potatoes, eggs, all the same. Is this bad practice according to food safety rules? I've had mild food poisoning a couple of times, and both times have been from restaurant visits. I always thought food safety is a much bigger concern for restaurants that deal with very large quantities of food, and that it's not such a big deal for home cooked food. I still believe this -- after all, I eat 20 times as many meals I made at home than from restaurants, and have never gotten sick at home. Then again, I have never worked in a kitchen -- maybe restaurant kitchens are even less concerned with food safety than I am, given the pressure to not waste food and make things quickly?"
],
"score": [
3096,
144,
123,
29,
24,
23,
22,
20,
15,
13,
13,
7,
5,
5,
4,
4,
4,
3,
3,
3,
3,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://www.nhs.uk/chq/Pages/can-reheating-rice-cause-food-poisoning.aspx?CategoryID=51"
],
[],
[],
[],
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jmpk6 | Why is antibiotics discovered so recently only? | Antibiotics are produced by fungi and bacteria that has been all around us all this while. But why is it only discovered during the 1920s, relatively late in human history. Was there no observations of animals treating themselves with antibiotic-producing-fungi? | Biology | explainlikeimfive | {
"a_id": [
"dr7ng8c",
"dr7l1mo",
"dr7nlpn"
],
"text": [
"> Was there no observations of animals treating themselves with antibiotic-producing-fungi? [Penicillium]( URL_0 ) mold produces penicillin. It also produces other chemicals that are poisonous to humans and animals. If you just eat the mold, it will make you sick. In order to get the antibiotic effect without harmful side-effects, you need to extract the good stuff from the bad stuff. That's going to be generally true of most chemicals made by fungi. Which is why we don't see animals treating themselves with fungi.",
"The discovery of microorganisms and how they correlate to disease is fairly recent. Thus the science behind how antibiotics work could be tested and verified. Throughout history before it, people tried all sorts of remedies for various ailments. Some were more effective than others, but without adequately controlled studies, it was hard to differentiate who recovered due to the remedy and who recovered simply because their immune system overcame the disease naturally.",
"Penicillin is made by a fungi, but you can't just eat a ton of the fungi to kill bacteria. In the presence of a bacteria the fungi will produce enough penicillin to kill off the bacteria, but won't be making the antibiotic if it doesn't need to. We actively induce the generation of penicillin to large quantities for our purposes. So self-treatment in nature wouldn't really work for antibiotics, but it is used in other circumstances (caterpillars eating milkweed to taste bad to some birds)."
],
"score": [
5,
3,
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Penicillium"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jmsyt | What is it that the is microwave 'sensing' when you choose sensor reheat? | Technology | explainlikeimfive | {
"a_id": [
"dr83vht"
],
"text": [
"That link covers most of it. The most common sensor in a microwave is simply a moisture sensor. Some higher end microwaves do have types of temperature sensors and there are even a couple out there with noise sensors to tell when the popcorn is done popping."
],
"score": [
12
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jn7bz | If video games are entertaining because they make your brain think it's accomplishing something, why would I rather play video games than write an essay? That's accomplishing something too. | Biology | explainlikeimfive | {
"a_id": [
"dr7oo17",
"dr7otea"
],
"text": [
"There have been many explanations but it simply comes down to a basic reward system. Most video games require you to work towards an end goal, this could be winning a match, scoring a point, killing all the zombies, leveling up your character, the list goes on. & nbsp; When you layer the simple rewards with external stimuli (sound effects, music, etc) it creates a very short feedback loop that gives players a sense of accomplishment and satisfaction. Balancing boredom and frustration is the main goal. & nbsp; Now none of this is typically the case when writing an essay. You have a much larger task at hand with no feedback loops and external stimuli to keep you going. So which would you choose?",
"Games are designed to constantly feed into your reward center. Every enemy you defeat you are rewarded. Every treasure, powerup, or point you gain, you are rewarded. Every match, level, or quest you complete, you are rewarded. It's all designed to keep you feeling like you're constantly accomplishing little goals and motivates you to keep going. Writing an essay usually doesn't feel like you've accomplished something until the very end. It indeed feels great when you're done with the essay, but there's no system constantly feeding your to keep writing to reach the end goal."
],
"score": [
7,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jn8u5 | Could a high powered laser ever melt a mirror? Or will it always be reflected? | Physics | explainlikeimfive | {
"a_id": [
"dr7o4nr",
"dr7o1ad"
],
"text": [
"Truly perfect mirrors do not exist for all frequencies and for all angles. That means they absorb at least a little bit of energy. That means that it's theoretically possible to create a laser to melt them.",
"A mirror isn't perfectly reflective, nothing is, and that means it absorbs a small percentage of the light that hits it and turns it into heat. If you hit it with a 100 PW laser pulse you'll melt through it instantly, if you just blast a few MW of power at it you can probably melt it in a few minutes even if it reflects 99.99% of the light that hits it."
],
"score": [
10,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jn8xe | Why does it sting when alcohol (or various other liquids) touches an open cut/wound? | Biology | explainlikeimfive | {
"a_id": [
"dr7oy7e"
],
"text": [
"Nerve receptors that let you know things are burning hot are activated by the chemicals. As a result, your brain gets a signal saying that something is burning you at the wound."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jn9u3 | Why do most airports usually have suitcase shops after security and well after you have checked your bag in? | Other | explainlikeimfive | {
"a_id": [
"dr7rnpy",
"dr7svr2"
],
"text": [
"Because the number one place to have the thought \"I really need a new suitcase\" is in an airport. Every other day of the year your luggage is in a closet and you're not thinking about it. So while you're dragging around your beat old carry-on bag with the wonky wheels and the broken zipper you get to look at shiny new luggage, and you might decide to buy some.",
"A lot of the shops at airports are targeted at people *leaving* the airport after having flown in, not at people *entering* the airport to depart on a flight. Does this make more sense to you in that context?"
],
"score": [
9,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jnd7s | Why dont we put warm food into the fridge? | I was always told as a little boy not to put hot leftovers into the fridge and never was taught why.... | Biology | explainlikeimfive | {
"a_id": [
"dr7p32s",
"dr82tfa",
"dr7pj55"
],
"text": [
"It's a myth. You absolutely can put hot food directly into the fridge. If it is a large amount of food you want to break it down into smaller portions and the refrigerate. There is a window of time when it is considered safe to eat food that is not at temperature to inhibit bacterial growth. The temperature will depend on the food in question on the hot end(arond 140 degrees) and 40 degrees on the low end.. If you put a large bulk of hot food in a regular home refrigerator it will take too long to cool it down to a the low temperature you need to keep it from becoming a bacterial orgy.",
"Condensation is a big reason to at least hold off on covering the dish, if not letting it cool on the counter first. Some foods that have a more sensitive maturing 'sequence' of its flavors or textures won't set properly if they cool too fast. The most important thing here is that food be brought to safe storage temp within two hours. You don't want susceptible foods (especially meats) growing nasty bacterial blooms! Putting food in large volumes into the fridge may keep the middles from not cooling in time; so for large volumes be sure to break your serving down into family size tupperwares or smaller. Don't just drop the whole 5-gallon pot of chili in the fridge!",
"The heat from your hot food will warm up the rest of the fridge. This happens any time you add food the fridge, but we like to minimize it whenever possible for a few reasons. 1. Refrigerators remove heat to cool food to whatever temperature they're set. So if you add something with a lot of heat, it has to work a lot harder to cool back down. 2. Depending on the temperature and the amount of hot food, the increased temperature inside the fridge can warm up the other food for a bit. So if you let food cool down on the counter before you put it in the fridge, you're not making it work as hard (good for the longevity of an expensive appliance), and you're helping keep the rest of your food cold, which also helps it's shelf life. It's also not a huge deal unless you're putting things in the fridge almost immediately after they come out of like, the oven. At that point, the extreme temperature differences could cause cracking if you're using glass containers/shelves, and plastic in the fridge that's in direct contact could be damaged too."
],
"score": [
15,
4,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jnhov | why are first names so common, while there is a whole array of last names? | Other | explainlikeimfive | {
"a_id": [
"dr7sjy0",
"dr7rnzj"
],
"text": [
"I think you will find there are nearly as many first names as their are last, but some names are more popular. As well you may note that there are some last names that are very similar to each other, maybe off by only a letter (Nelson - Neilson, McDonald - MacDonald, Johnson-Johnston). Parents can pick any first name they want, and often have gone with Biblical names (Adam, David, John) so these names reoccur often, but of course today we see some pretty off the wall names, some just rare, and some fabricated. A culture tends to favor certain first names but last names come from all over the world but if they live in a certain culture they may pick names of that culture.",
"Quite simply, there are a lot more people than there are families. Also, last names (in Europe) started in the Middle Ages and were named after jobs. This continued for for hundreds of years and why last names like 'Smith' came to be. Also in China (and elsewhere) people would use there state as a last name."
],
"score": [
17,
8
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jnlb6 | Why do some people get paralysed by fear? | Biology | explainlikeimfive | {
"a_id": [
"dr7qdyb",
"dr7qem0"
],
"text": [
"There is a lot of data programmed into us (in our DNA) from before we became \"civilized\" that still has a grip on us. Holding still is often a way to fool a predator, particularly predators who rely on MOTION to detect prey.",
"It's the third option in the \"fight or flight\" response. When people freeze, their brain decides being perfectly still so the attacker can't see you is the best response. This is rooted in the fact that some of man's early predators reacted to motion. So being the one that didn't move meant you were the one that didn't get eaten."
],
"score": [
3,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jo161 | If we ever can achieve faster than light travel, would there only be a sonic boom after breaking the sound barrier? What would happen once we break the light barrier? | Physics | explainlikeimfive | {
"a_id": [
"dr7tymt"
],
"text": [
"This question is impossible to answer; you can't ask someone to put aside physics to allow you to travel faster than light, and then ask them what those same physical laws say is going to happen. You cannot go faster than C."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jo765 | Why do we toss and turn/constantly reposition ourselves during our sleep? What makes one position suddenly stop being comfortable even when we are not fully conscious? | Biology | explainlikeimfive | {
"a_id": [
"dr7x85r",
"dr8t802"
],
"text": [
"Usually this is due to ischemia- lack of blood. When you're sitting in a position too long your body tells you to move, whether or not you realize it, to get the blood flowing back. If blood is robbed from an area of your body for too long, the tissue dies. If you don't move, you get something called a pressure ulcer. Pressure ulcers have four stages and a last stage called unstageable. They are not pretty sights (do a google search). People get these because they cannot move when their body tells them to. Thus, the blood flow stops and the tissue in the area dies. In the hospital, we have turn schedules for our paralyzed patients to turn them every hour or two so their flesh doesn't die. When you're sleeping, your body is unconsciously moving to keep that blood flowing all while you rest peacefully.",
"Try to remember the last thing you were thinking about right before you decided your current position was uncomfortable. You’ll often notice that an anxious thought can trigger your sympathetic nervous system into gear, releasing cortisol and causing alertness. Your first reaction to this new state is “I must be uncomfortable” and you adjust. If you are constantly tossing and turning throughout the night it could be because of a number of physical or mental stressors in your life. Poor diet, stressful work day, lack of exercise, too much exercise, eating too late at night, financial or relationship issues, scary or intense movies right before bed, too much caffeine, consuming alcohol, not keeping a regular sleep/wake schedule, etc."
],
"score": [
203,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jo8ac | How does a penis triple in size while erect? | Biology | explainlikeimfive | {
"a_id": [
"dr7vuc1",
"dr7vn3y",
"dr7wpfs"
],
"text": [
"Imagine a balloon. At the start, the balloon is small. After u blow air into the balloon, it gets bigger and bigger. But instead, the balloon is ur penis and the air is ur blood.",
"Human skin has a natural elasticity, like a rubber band, and can stretch a little, or a lot, depending on the area. The extra mass that fills the skin is blood within the veins and muscle. That’s what ‘engorged’ means. When you’re not excited there’s less blood flow to the area so it’s in the rest of your body doing other stuff.",
"The penis is, essentially, a balloon with a hose running through the middle of it. When arousal occurs, blood is directed into the penis, filling it in a manner not unlike a water balloon placed over a faucet. It doesn't gain any new tissue; when there isn't extra blood in the penis stretching it out, it contracts and relaxes into its flaccid shape. Further, not all penises triple in size during erection. Every owner of a penis exists somewhere on the sliding scale of \"grower\" to \"shower,\" with some individuals gaining no extra length from erection, and others who measure within the average zone during erection can have something classifiable as a micropenis when flaccid."
],
"score": [
3,
3,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jo8hx | Is moving less than a planck length possible? | Moving a planck length per planck time means moving the speed of light, so massive particles should move less than a planck length in a planck second. Ive heard that planck lengths are like the "pixels" of space, so should moving less than a planck length be possible | Physics | explainlikeimfive | {
"a_id": [
"dr7ymci",
"dr8164w"
],
"text": [
"Short answer: Yes, moving a distance of less than a Planck length is possible; in theory, there is no limit as to what the smallest distance something can move is. But things are weird at such a small level, so let me explain. If you move, say a marble, .1 meters, that's pretty small. But you can go smaller. You could move the marble .01 meters. From there, you can move the marble smaller and smaller distances because you can always add a zero before that one. The conclusion of this thought experiment is that there is no limit to how small of a distance you could move the marble because there is no limit to how many zeroes you could add to the distance. Now when we get to distances like the Planck length, things start to get funny. At sizes that small, matter and energy start to behave in different ways than what we do at a normal level. Particles can pop in and out, other particles can \"communicate\" with each other (an idea known as superposition), and our ideas of natural laws start to break down. At such a small level, quantum mechanics govern. The reason why we have \"the shortest distance\" being the Planck length is because that is the smallest meaningful length that can be used in classical mechanics; anything smaller would be governed by laws that don't apply to what we don't know. So in a nutshell, you *can* move a distance smaller than a Planck length, but there is not much meaning to it because classical mechanics does not apply at such small distances. Edit: Wording",
"You absolutely can have something move a distance smaller then the Planck Length, and in fact it wouldn’t be hard to argue that there might be some undiscovered particle that does (we don’t know of any particles that do, it just wouldn’t be hard to make the case that something like that might happen). That said, the planck length is simply a length derived from the Gravitational Constant (G), the Speed of Light (c) and the Reduced Planks Constant (ℏ) according to sqrt((ℏG)/c^3) The above equation works out as far as units are concerned (which means that every unit we don’t want gets crossed out as you solve the equation) but doesn’t really prove anything past that. Currently it’s not known if the value of the planck length actually has any signifigance, but there are a few theories. Scientists think that it could be the point below which physics simply no longer works, or at least that’s what we think might happen since we don’t know what happens at such small levels. This idea does makes sense, since ℏ is the smallest increment of energy any system can have (more accurately, this value belongs to h, which is ℏ multiplied by two pi, but some things are measured in ℏ and this is less confusing as a sentence imo) so it makes sense that a length derived from it should also be a minimum of sorts. The other theory is that the planck constant is quite literally the “pixel” of our reality and any attempts to go below it will simply result in black holes. In other, simpler, words hears what that paragraph is trying to say; the Planck Length by itself isn’t definitive proof that you can’t go below it. There are theories that predict what happens below this length and they state that A. Physics breaks down but with lots of fun new physics in its place. B. Physics breaks down and the more we try to go below it the bigger of a black hole we make. Neither of those two theories are definitively proven, but they do at least make some sense when you go into the details. Ok, now to answer the time part of this question. As I was saying before, Planck Units are simply derived units from constants and we don’t know if there’s any signifigance behind them. This is especialy true for the Planck Time since, unlike the Planck Length, there’s no theories that inter signifigance to it. In other words, planck time is just a very well defined value of time and there’s nothing stopping it from going down to even smaller increments."
],
"score": [
25,
4
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7joarj | How do heat sinks like the ones on CPUs work ? | You put some paste on the cpu and then slap a huge aluminum(?) block with some copper tubes and a fan attached to it and all of a sudden it won’t melt anymore. Magic ? | Technology | explainlikeimfive | {
"a_id": [
"dr7ybsn",
"dr7wbwo",
"dr8bgep",
"dr8wrk9"
],
"text": [
"heat moves between two localities to move towards equilibrium. the CPU is really hot like 150+F. the heatsink is less hot like 120F. the CPU heatsink dissipates heat into an even bigger heatsink: your room's atmosphere where it's like 70-80ish F. and your room atmosphere mixes with your home's atmosphere which mixes with open air atmosphere.",
"The thermal paste acts as a thermally conductive filler. As the surface of the heat sink base and CPU lid aren't perfectly smooth, air bubbles would otherwise form, and trapped air is an extremely poor conductor of heat. The general idea of a heatsink is that heat passively flows from hot to cold. In this case, the hottest part is the CPU package, and the fins are passively or actively cooled by air.",
"Heat transfer is proportional to surface area & the material you're transferring to. It's *much* easier to transfer heat into aluminum than it is into air. Since the face of the CPU is very small, you want to hook it up to something that'll take as much heat as possible. The heatsink then creates a *lot* of area to contact the air, making it practical to dissipate the heat.",
"A heatsink is designed to increase the surface area of the object that needs to be cooled. Metal and water are great thermal conductors, but air isn't. So you create an object to spread the heat load more evenly and make contact with as much air as possible. You can do this with a big metal plate, which is what a lot of low power mobile devices use. For more serious cooling though, you use fins. Thin metal fins are allow you to create a lot of surface area without drastically increasing size of the heat sink. We then attach a fan so hot air is pushed out and a continuous stream of cool air is run past the fins. The copper tubes attached to some heatsinks are heat pipes. They contain a small amount of liquid. When this liquid hits the hot conductive metal plate on top of the CPU, it vapourizes, and naturally gravitates to the cooler end of the pipe, where the cooling fins are. It then condenses back into a liquid and repeats the cycle. This is somewhat similar to how a refrigerator works, except this process is entirely passive. You can also kick it up a notch to liquid cooling, which uses flowing water as the heat transfer medium. Neither traditional finned heatsinks or water cooling can cool a chip lower than the ambient air temperature though. For that you have to go to exotic cooling methods like phase change (an active refrigeration cycle), dry ice, or liquid nitrogen. None of which are really practical. The paste is thermally conductive ceramic compound. Sometimes mixed in with a small amount of metal that's exceptionally conductive, like silver. It fills in imperfections on the CPU and heatsink, to make the best contact and eliminate hot spots. These hot spots can damage the chip, so processor heat sink should never been installed without it."
],
"score": [
4,
4,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7joce0 | when people say certain foods "strengthen" the immune system (like garlic?), what does that actually mean? | Biology | explainlikeimfive | {
"a_id": [
"dr7wq00",
"dr867t6",
"dr7ygk3"
],
"text": [
"Mostly old wives tales. Sometimes simply filling deficiencies you have day to day that interfere with your body doing a good job of fighting disease. But the placebo effect is real so keep at it if it helps.",
"It usually means that they're trying to sell you that food. Often for more than its really worth.",
"Usually nothing. If there was an easy way for your body to fight off infection even better, it would already be doing it. That said, certain nutritional deficiencies can make your more prone to sickness. The one, surefire thing you can eat to boost your immune system is called \"a balanced diet\"."
],
"score": [
20,
4,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jokuk | Why does the antibiotic I'm taking, liquefy my feces? | Biology | explainlikeimfive | {
"a_id": [
"dr85pdw"
],
"text": [
"Your gut is filled with bacteria. And that bacteria does help with digestion. And you just killed it. Thus your digestive tract is not working properly. But here is the other fun thing that might happen. You could get a skin fungal infection as well because those Abs also will kill your surface skin bacteria leaving a nice open environment for fungus. if you end up with red bumps over your body, it could be a fungus. Just be prepared. Antibiotics don't really just target the bad stuff. They go for it all."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7joo96 | How do studios make such strikingly real animation? | How is the 'world' of a big-budget animated film created? Watching something like The Jungle Book, The Good Dinosaur, Moana, etc.. it looks like the most ridiculously immense and intricate process that I can't actually wrap my head around. | Technology | explainlikeimfive | {
"a_id": [
"dr818h5"
],
"text": [
"congrats. you noticed. because it IS a ridiculously immense process. that involves HUNDREDS of highly skilled artists, and ridiculously smart software engineers working for YEARS. this is just one tiny piece of Moana. URL_2 one tiny piece of Zootopia URL_1 one tiny piece of Incredibles URL_0"
],
"score": [
4
],
"text_urls": [
[
"https://imgur.com/cSEeWBZ",
"https://www.youtube.com/watch?v=zaqmn55w4IA",
"https://www.youtube.com/watch?v=S-HG8IA-2TI"
]
]
} | [
"url"
] | [
"url"
] |
7joov9 | How did the 1864 Presidential election work without the electoral votes from the Confederate states? | Other | explainlikeimfive | {
"a_id": [
"dr81zc5"
],
"text": [
"> Since they weren't included, does this mean the Union recognized the Confederacy as a sovereign state No the Union did not recognize the Confederacy as a Sovereign State. Technically the Union didn't take any legislative action at all. The Constitution requires the Secretary of State or similar position of the State in question to conduct the Electoral College in their State, tally the results, and mail them to Congress addressed to the Vice President. The Vice President then opens them up in front of a joint session of Congress and Congress has the opportunity to challenge individual votes if a member of both the Senate and House object. With the exception of two States(Tennessse and Louisiana), the Confederate States simply did not mail the results of the Electoral College they didn't conduct to Washington. With no votes in the mail there was nothing to count. The votes from the two Confederate States were challenged and disallowed."
],
"score": [
18
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jovg5 | Advantages/Disadvantages of a space station ( I.e. ISS) vs. Lunar Base (cost, difficulty/risk, scientific value...) | Other | explainlikeimfive | {
"a_id": [
"dr82456"
],
"text": [
"The moon is *very* far away. The ISS is close to us. It's longer to go from New York City to Pittsburgh than from Earth to the ISS. The moon is almost a thousand times further away. You could go around the earth ten times in the distance it takes to get to the moon. That means it's a lot easier to get to the ISS than to a moon base. That's a huge advantage when *everything* at this off-world base has to be brought in from Earth. You might be able to afford a dozen ISS style stations for the same cost as one base orbiting the moon. Getting people back from the ISS is *very* easy. You put them in an insulated capsule with a parachute attached and give them a nudge in the right direction. Getting people back from the moon takes a large rocket. It's expensive, it takes more math and navigation effort to get back, and more can go wrong. It's also a lot easier to talk to people on the ISS than on the moon. You can do it with a much cheaper radio. And they can pick up your signal almost instantly. It's close enough that you can get internet access there. On the moon, you'd have several seconds of delay, and that breaks internet access. Granted, that's a minor annoyance. The moon's surface is covered in sticky, sharp dust. (It's statically charged, and it doesn't have an atmosphere to erode away the edges.) This caused a lot of problems with past missions to the moon. The ISS, on the other hand, is subject to orbital debris. We don't have enough junk in orbit for that to have caused major problems yet, but it could. The ISS can conduct experiments in microgravity. This is significantly different from Earth conditions. A lunar base can conduct experiments in reduced gravity. The ISS can somewhat replicate those with a centrifuge. A lunar base could be more self-sufficient if we developed appropriate smelting and manufacturing techniques. Microgravity is unhealthy for humans. The moon has some gravity -- about one sixth as much as Earth. That might be enough for humans to live there successfully for a long time."
],
"score": [
19
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jp8t6 | Biologically, why do humans cheat? (And a second question) | Why do some people have the desire to cheat? My assumption would be that it was beneficial to our ancestors to have multiple mates, rendering them more fit. Fit being the most able to reproduce. Is this correct? Second question that may relate, why do some people desire incest or incest-like relationships. Was it beneficial for us to have incestral relationships, Or does that have to deal more with psycology of our modern brains? | Biology | explainlikeimfive | {
"a_id": [
"dr8blhx"
],
"text": [
"For your first question; men tend to cheat because it is biologically important to spread their seed as much as possible. They do not have a very long reproductive cycle, so they can impregnate many women very rapidly. All organisms tend to want to reproduce as much as possible, and humans are no exception. Women tend to cheat when they believe (instinctively, not actively) that they have found a better partner. Because women have a long reproductive cycle with a finite amount of potential eggs and potential mating years, they want to ensure that they have the best possible mate for any given reproductive cycle. Your second question is much easier to answer. It's been shown that people are attracted to others based on several factors that boil down to \"how similar are they to me or my parents\". Smell, appearance, and personality all play a role here. If they smell like your family, look like your family, and act like your family, it makes sense that we would believe they would produce viable offspring because... hey, you're alive, and your whole family is alive. Obviously, this combination of genetics works. It should be noted that, when we're talking about mating, very little cognition is involved in the cheating or partner-choosing aspects. We don't sit down and write out pros and cons, we just go with what feels right. We want that \"spark\" that makes us attracted to people. This is all instinctual, which is subconscious. This is why it can be difficult for some people to overcome the instinctual desire to do these things, even though society today frowns on it."
],
"score": [
15
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jpb9y | Why do we get nose bleeds from the air being dry? | Biology | explainlikeimfive | {
"a_id": [
"dr85xr9"
],
"text": [
"Dry air causes the soft, wet, and squishy bits inside your nose to dry out and form crusts. These crusts adhere to the little tubes of blood in your nose. When the crusts fall off for any reason they can cause bleeding as they were helping close the tubes off. The crusts may break when you blow your nose too hard or you scratch or pick your nose."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jpjnb | What is that fuzzy feeling you get when your forehead gets close to something? | Biology | explainlikeimfive | {
"a_id": [
"dr8k66k"
],
"text": [
"What you are feeling is the small hairs on your skin being attracted to something with a lower charge than your body. Basically, the electrons are trying to find a way to neutralize themselves. It is called electrostatic attraction. Basically, your body, on an atomic level, can get a positive charge of electrons due to fuzzy clothing or something like that, and due to the laws of physics, your body will try to find a way to \"neutralize\" this charge, as in, neither positive or negative. It does this when you touch something that has a neutral charge, preferably something with a ground source, like a metal door or a radiator. When you feel a shock from something that shouldn't normally shock you, it's probably because of your electrostatic charge grounding itself, also known as \"electrostatic discharge\". This is also why sometimes, if you rub balloons, they will stick to your skin or walls or stuff. I think they lose electrons when you rub them (or they gain electrons, not sure), and then they stick to you because you have a different charge, so they are discharging into you. Don't take that out of context. edit* added clarification edit edit* okay so it's not really as simple as I make it out to be. I just read about it [here]( URL_0 ), very informative article. However, the sensation you are feeling *is* due to electrostatic charge between the small hairs on your forehead and the material that it is close to."
],
"score": [
4
],
"text_urls": [
[
"http://www.electrostatics.net/articles/static_build_up_on_people.htm"
]
]
} | [
"url"
] | [
"url"
] |
|
7jpogq | Why is it not possible to have drugs like MDMA in the body indefinitely so you can have good feelings and keep the serotonin levels high? | The effects lasts for hours but is it possible to feel euphoria permanently? > Because the levels of this feel good chemical increase well beyond its normal threshold, when the drug leaves the body, the levels of serotonin plummet, often leaving the drug user in withdrawal. URL_0 | Biology | explainlikeimfive | {
"a_id": [
"dr882z9"
],
"text": [
"Mdma triggers your brain to release all its serotonin at once, essentially. You only have a limited amount. When the effects of the drug wear off, your brain rubber bands and takes it all back in and then some, leaving you out of balance, in a process called reuptake. This is what causes the depression afterwards. This is also why a serotonin reuptake inhibitor works for depression, it blocks the receptors that take back serotonin, leaving more active serotonin than your brain normally regulates. Too much mdma can cause serotonin syndrome, which can affect your ability to regulate body temp among other things, and it can kill you. It's actually a good thing mdma only works so much, else we'd have a lot more injuries. While mdma rarely is the direct cause of death, it's effects on other systems can be."
],
"score": [
14
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jqlen | How come batteries can die out without being used just from placing them in a device, but keep their energy stored if not? | Chemistry | explainlikeimfive | {
"a_id": [
"dr8lou3"
],
"text": [
"Lots of devices aren't entirely off. They maintain a clock, volatile memory and such. So if you leave the batteries in there is a slow drain on them that isn't present normally. Of course, batteries don't strictly speaking keep their energy when stored. Single use batteries can hold a long time, but rechargeable often leak away their charge in a month or so."
],
"score": [
16
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jqzjn | How do BIP39 mnemonics work? | So I got a hardware wallet for my different cryptocurrencies. How do we get from the mnemonic to a private key? How many private keys do I have? How does the software know my addresses? I understand the benefit of mnemonics, but I do not understand how this little phrase contains this much information and where and in which form the information is saved. What are those "/40/m'" things you can see sometimes? | Technology | explainlikeimfive | {
"a_id": [
"dr8w6xd"
],
"text": [
"> How do we get from the mnemonic to a private key? > To create a binary seed from the mnemonic, we use the PBKDF2 function with a mnemonic sentence (in UTF-8 NFKD) used as the password and the string \"mnemonic\" + passphrase (again in UTF-8 NFKD) used as the salt. The iteration count is set to 2048 and HMAC-SHA512 is used as the pseudo-random function. The length of the derived key is 512 bits (= 64 bytes). [source]( URL_0 ) ELI5 version: hash the mnemonic as if it was a password > How many private keys do I have? The above process generates a single root, which itself generates chains of private keys. The number is essentially unlimited. > I do not understand how this little phrase contains this much information The mnemonic sets the starting point, from which math manipulates that number to generate the next number. You could think of it as the mnemonic generates a value X, and the math does some function like \"add 1 to get the next value\" (obviously the actual math is crazy complicated, but there's no difference to the computer, it's just running math code either way). > What are those \"/40/m'\" things you can see sometimes? Sounds like character escaping, but I'm not sure. Where are you seeing it?"
],
"score": [
3
],
"text_urls": [
[
"https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki"
]
]
} | [
"url"
] | [
"url"
] |
7jr3c6 | What is Common Law? | Other | explainlikeimfive | {
"a_id": [
"dr8hs67"
],
"text": [
"Common Law has variable definitions, but generally it refers to law that is derived from the decisions of judges (what we call “judicial precedent”). This is in contrast with Civil Law, in which the laws are created independently of the judiciary and centrally codified. An example: let’s say that somebody is accused of murder, and argues an insanity defense. Well, “insane” means a lot of different things. Is it a defense to have *known* that you were murdering somebody, but to be so crazy that you didn’t care? Or do you have to be so mentally ill, so delusional, that you couldn’t even comprehend that you were killing somebody? In a common law system, judges have thought about these questions for a long time, and written decisions about them. The principals that the judges write down are called “precedent,” and they are used to guide the decisions of other judges in the future. So our judge will look at what all the past cases have to say about the insanity defense, and will use that to determine what she should do in *this* case. By the way, even the idea that there’s such a thing as an “insanity defense” will have come from judges. In a pure common law system, that’s where those kinds of laws come from. In a civil law system, there is a book somewhere full of laws. That book says “this is what the insanity defense is and means.” And that’s that. The judges go based off that code, and are not guided by what other judges may have thought. In the US, we use a mix of common law and civil law. Our common law came from England — when our judges were first starting out, they relied on all the past decisions that English judges had set down. Over time, a lot of the principles that came from these judges were “codified” — that is to say, we wrote them down and put them in a book, and now we use those books instead of the old decisions. However, judges will still rely on precedent for help interpreting what’s written in the books."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jr3rs | Isn't everything of natural "origin"? | Chemistry | explainlikeimfive | {
"a_id": [
"dr8horf",
"dr8iksy",
"dr8mj50"
],
"text": [
"Strictly speaking, there is nothing in the universe that is unnatural. The idea that something touched by humans is somehow excepted from nature is just evidence of our hubris.",
"In this case, \"natural origin\" means \"not artificially chemically produced by humans, but instead sourced from non-human-produced primary sources that is then harvested by humans\". It's natural meaning \"not synthetic\".",
"> Isn't literally everything from natural \"origin\"? if you want to be a pedant, you can argue that. and yes, companies use such pedantry to mislead consumers almost constantly. that doesn't mean the concept of \"natural\" is meaningless or without use. indeed, when you encounter such an obvious contradiction, it likely means your intuitive definition is innacurate and the concept is simply deeper or more nuanced. for instance. apples have been cultivated since time immemorial, we have evolved together. we can trust millions of years of evolution and the whole of human history to tell us the apple is safe to eat. if you crush the apple, it's still the same apple-y stuff that was safe before and is safe now. but what if we hydrogenate it? ferment it? take it far enough and you could make literal plastic out of it. I think you would agree that plastic would be unnatural. in this context, \"natural\" could be used to indicate composition. a natural apple product would be composed of compounds native to the apple. this is how natural flavors work. they have extracted the fruit flavor from the fruit and put it in the product. you know what those are intuitively (though not explicitly) if you have eaten the fruit and made the choice to consume them. artificial flavors, in contrast, can taste the same, but you may not have the same confidence in their safety. while we have tested them in labs, history has shown our attempts at mimicking nature have fallen short, and we as a society recognize your right to make an informed decision about what you consume."
],
"score": [
51,
19,
4
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jrf2y | - Why do computer memory systems use 1024 not 1000? | Is it something to do with Base 8 Numbers (8/64/1024) not Base 10 (10/100/1000)? Also why is it 1024MB to 1GB, but 1000GB to 1TB? | Mathematics | explainlikeimfive | {
"a_id": [
"dr8k3j4",
"dr8mm80",
"dr8rdje",
"dr8s43r",
"dr8x6e4",
"dr8vpnu",
"dr8ymev"
],
"text": [
"> Is it something to do with Base 8 Numbers (8/64/1024) not Base 10 (10/100/1000)? Almost there. Computers don't use base 8 they use binary, ones or zeroes. It is (2,4,8,16,32,64,128,256,512,1024) as you increase in binary digit places.",
"1024 is a nice round number in binary. It's 10000000000. So for many purposes it's easier to take 1024 bytes as a unit than 1000. There are different definitions of units like KB, MB, GB and so on. Hard disk manufacturers in particular take 1GB to be exactly 1000MB instead of 1024. Supposedly 1024MB is actually one Gi*bi*byte, but barely anyone calls it that. Most people would call it a gigabyte.",
"To expend on what has already been said. Imagine a small box where you can store a 0 or a 1. That’s a bit. Now imagine that you have 2 of them side by side. To control in which one you’re going to read/write you put a switch before them. If the switch is in one position, the bit goes in one of this box, and if it’s in the other position it goes in the other box. Now imagine that you want 3 boxes instead of two. If you have only one switch that’s not going to cut it. The switch can decide only between 2 positions. So you need one more switch. But if you put 2 switches then you can decide between 4 positions and not just 3. Putting only 3 boxes is then kind of wasteful when with the same circuit you can put 4 of them. Now use the same logic with very big numbers and you’ll understand why everything is base 2 with semi-conductors.",
"A bit is the smallest possible piece of information I can query. It can be in two states: 0 or 1; on or off; up or down; etc So one bit gives me two possible states. If I have two bits then I have 4 possible states: 00, 01, 10 and 11. So if I have n bits I can have 2^n possible states. The other comments go from here.",
"There are 10 types of people in the world: Those who understand binary, and those who don't.",
"Binary. Computer switch is on or off, electricity going through or not going through. Binary is powers of 2, 2/4/8/16/32/64/128/256/512/1024/2048/4096. That's why those numbers sound familiar even if you suck with computers, that's what every memory card, phone storage, computer storage comes in.",
"Computers only understand two things. * \"On\" and \"Off\" * 1 and 0 So using this they don't count 0,1,2,3,4,5,6,7,8,9. They count 0,1 So how do they express 2? The same way we express 10. Add another digit. So a computer counts like this: * 0 - 0 * 1 - 1 * 10 -2 * 11 -3 * 100 - 4 * 101 - 5 * 110 -6 * 111 - 7 Now as a side effect of this, 1000 is not a nice round number to them like it is to us. Using 1000 would be wasteful. * 1,000 = 1111101000 * 1023 = 1111111111 - See how **every** bit is used? Now wait a second Sergei, I thought you said 1024? Why only 1023? Well computers don't start at 1. They start at 0. So there are 1024 different values. 1-1023 + the 0 value for a total of 1024."
],
"score": [
254,
84,
62,
21,
17,
5,
4
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jrgk1 | How does Youtube monitor the millions of videos posted every day for things like copyrighted music, images, and also “advertiser-unfriendly” content? How does Youtube know if the subject matter of your video is “inappropriate”? | Technology | explainlikeimfive | {
"a_id": [
"dr8lprz"
],
"text": [
"A company like Youtube has too many videos for their own employees to monitor. Instead, there are two real mechanisms for youtube to monitor content: The first is crowd-sourcing and the second is computers. On a video, there's a little button to \"Report\". When a user clicks \"report\" a message is sent to a relatively small team of monitors who check the video to make sure it's OK and remove it otherwise. That's crowdsourcing, because the crowd of users is doing most of the work (identifying and flagging the bad videos). Similar to crowd-sourcing is the idea that the video creators, when they upload content, can tag their own videos with things like \"uses bad language\" or \"inappropriate for children\". A faster way to identify some problems is through computer software. Let's say we want to avoid duplicate videos, or we want to check for videos that are copyrighted: We'll compute some kind of \"checksum\" for the videos and compare it to a list of known videos. If the checksums are equal, the computer automatically flags the video and it's sent to that same small team of monitors to verify. Checksuming is why you see some videos on youtube from TV shows or movies with a boarder around them, or flipped left-to-right, to change the checksum and avoid this detection. There's also the emerging field of AI, where computer learning algorithms can be taught over time to recognize things like nudity or curse-words. In this case you take a small \"training set\" of known examples and train the AI algorithm, then set it loose on your \"working set\" of all videos. The AI will flag videos it thinks are like the training set, and the team of monitors will verify and take action. Sometimes, if you have enough trust in your AI program, you can skip the team entirely and just have the program delete videos directly (and then the creators would need to take action to save it, if they thought it was an error)."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jrk8k | this may belong in an NFL subreddit, but: In the NFL, why do kickers for a field goal have a hard time getting it 50 60 yards when they routinely kick more than 70 80 yards for kickoffs? | Other | explainlikeimfive | {
"a_id": [
"dr8lyut",
"dr8onid",
"dr8mnmn"
],
"text": [
"On kickoffs, they're kicking off of a tee, they're not being rushed by the opposing team, and they're only trying to keep the ball within the sidelines. For a field goal attempt, their run-up to the ball is only three or four strides because otherwise the kick will be blocked, the ball itself is being stood up on its end and held by hand, and the kicker is trying to kick it between the uprights.",
"Just to be clear... If the ball is on the say 50 yard line, it usually means the kick is placed I THINK 8 yards behind the snap? So the field goal is placed at the 42. The endzone is 10 yards deep, and the upright is 10 feet high... So when you try to kick a field goal on the 50 yard line it needs to be over 10 feet in the air at 68 yards away, meaning it will probably hit the ground about 75 yards from the tee.",
"On a kickoff, players are allowed to run downfield before the play starts as long as they're not offsides. Kickers can take a huge run up to the ball because technically the \"play\" doesn't begin until they strike the ball. This allows them to kick very far. On a field goal, the kicker can take as much of a running start as he likes, but the caveat is that players on the offensive side of the ball cannot be moving forward while the ball is snapped (except in arena football). This would be an illegal motion penalty. Since the kicker can't start moving forward until the ball is snapped, and the other team rushing him means he'll have a limited amount of time to kick, if he has too long of a run up to the ball, it will be blocked."
],
"score": [
101,
9,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jrq53 | What happens to issuers of Credit Default Swaps (CDS) if they can't make payment? | I've seen two CDS 101 videos and the Wiki, but none of them said exactly what happens besides an implication of disaster which doesn't really answer anything. So Let's say a CDS issuer (CDS Corp.) has sold CDS' worth $10 million, but only has $3 million in total assets.. ..what happens if the defaults occur? Are CDS issuers mandated to have insurance to protect themselves for this? If not, what happens? Does the government satisfy existing debts of CDS Corp? | Economics | explainlikeimfive | {
"a_id": [
"dr8n2d3"
],
"text": [
"If CDS Corp. can't cover its obligations, it will default, and the short answer is, the buyers of those swaps will be out of luck; the protection that they assumed they had against an underlying default is gone. That said, it's usually a little more complicated than that. CDS Corp may be short on assets to cover the swaps, but it's possible that they're still creditworthy, and will be able to borrow the $7 million needed to pay everyone off. They may be able to file for bankruptcy, in which case the $3 million will be divided among their creditors. They may also have insurance - or have purchased swaps from another issuer - in which case everything proceeds as normal. However, if the event is particularly bad, the insurance companies may also default. There is no legal requirement for insurance, but the price of the swaps may account for the financial position and risks of the issuer. The government has no obligation to bail out CDS Corp. To prevent a financial crisis, it may do so."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jruxk | Why is it not possible to just cut out the cancer and throw it away, instead of killing the whole body with chemo? | Biology | explainlikeimfive | {
"a_id": [
"dr8ncyf"
],
"text": [
"You can, you just need to make sure you cut out every single cancer cell, otherwise it'll just regrow. Cancer cells can also travel through your body and settle in other places (through your bloodstream). Chemo will poison your entire body, the hope is that it'll just kill the cancer cells faster than your normal cells (cancer grows faster, so it needs more fuel)"
],
"score": [
14
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7js1jw | What is design and systems thinking? | I've referred to various definitions and examples but I don't think I still catch what it's all about. | Technology | explainlikeimfive | {
"a_id": [
"dr8pbpp"
],
"text": [
"Most people tend to think of complex dynamic systems in terms of individual components, without fully grasping how they interact and the impacts of those interactions. Let's say you've got a team project due tomorrow. Collectively, your team needs to write a 20-page paper describing your work. So you divide the work up into 5 sections, assign everyone a section and you all work independently. Everyone finishes their work by the deadline and you're all set, right? Wrong. In all likelihood, none of you actually completed your task because certain elements of one section were dependent on the others - and you needed information from other group members to do a good job. The entire document as a whole needs review and markup based on standards established group-wide. Simply \"doing your job by the deadline\" in this case is a strategy that leads to failure. You need to come up with mechanisms for coordinating the work beyond this simplistic notion of dividing up the work. Moreover, you also have to deal with failure modes. Consider that slacker member of your group who never gets their work done. If they completely fail in their assignment, you'll lose points on your grade. So if the deadline is 9 am tomorrow, at what point will you need to do their work for them to complete in time? How do you communicate this to other team members so they're not doing redundant work? 'Systems thinking' is thinking about all of these issues that arise when coordinating different tasks and recognizing the inter-relationship between those tasks. It involves examining dependencies between tasks, and how unforeseen events can affect not just one particular task but all tasks in the system. A 5-person academic project is fairly easy to coordinate. Much of the time you end up with one person doing most of the work, two people who add some comments/graphics/whatever and two people who do virtually nothing. It's an inefficient approach, but it's easier than trying to get everyone to work up to their potential. But once you scale that up to thousands and thousands of people, this sort of casual approach to managing the task flow fails utterly. You need people whose entire job is thinking about how the complex dynamic system functions - and ensuring it continues to do so."
],
"score": [
20
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jsm5p | How can Disney continue to buy out huge companies and not be considered a monopoly? | Economics | explainlikeimfive | {
"a_id": [
"dr8tjo9"
],
"text": [
"successful politics and lobbyism disney is especially successful and well connected in this, see the the history of intellectual propery laws in the US and new global trade agreements, most of it is based directly of Walt Disney's exclusive ideas and wants."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jssw9 | how does a company buying another company work? | Economics | explainlikeimfive | {
"a_id": [
"dr8w4cs",
"dr94m5o",
"dr8vslf",
"dr9adz7"
],
"text": [
"The $10B goes to the owners of Instagram. They keep the money, but now no longer have ownership of Instagram. Facebook now has $10B less than they did before, but have gained the assets of Instagram",
"If you buy a car for $10k, you don't pay the car $10k. You pay the *owner* of the car, and you take the car in return. Companies don't own themselves. Any company has an owner or owners. It may be another company, the founders, investors, the public (via the stock market), employees, or some mix of all of those. Those owners are the ones who receive the proceeds of the sale.",
"Instagram had investors... the founders, employees who got stock grants, VCs, etc. who owned shares. They all get the money and/or shares of Facebook when Instagram is bought. So let's say Facebook paid $10 billion, 50% cash and 50% in FB stock. Let's say a founder has a 10% stake when the transaction takes place... so his percentage would be worth $1 billion. He would receive $500 million in cash and $500 million worth of FB shares.",
"Similar question: how do hostile takeovers work? Why can't a company just be like \"pfft, no you aren't taking my company\" ?"
],
"score": [
31,
18,
7,
4
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jsuju | Why isn't AC electricity converted to DC before it reaches the power outlets? | Why is it that every device has to convert AC from the wall into DC, instead of converting AC to DC when it comes into the building and having the wall outlets run DC? | Technology | explainlikeimfive | {
"a_id": [
"dr8w4ya",
"dr8x6p8",
"dr8ysx0",
"dr8vlf6",
"dr95pg7"
],
"text": [
"First of all, there are appliances that run better on AC power, so why waste effort on converting it? Items that involve motors or resistive heating either want AC power or are perfectly fine with it. Second of all, you don't know the voltage of all possible DC appliances. If you're going to need to transform your voltage anyway, you might as well just leave the power as DC. In theory, you can speculate about some future where all the power sockets in our homes are 5V USB-Q or something, capable of charging your cellphone or running your washing machine with equal facility. But we're not there yet.",
"Different devices have different power needs, and AC is much simpler to change level than DC.",
"Every device? Only the most modern electronic devices use low-power DC. Historically—until a decade ago—most devices we plugged in used 120-volt AC to run motors or heat filaments.",
"It creates a few issues. What voltage would you run at? If devices have to do massive amounts of DC-DC conversion anyway, what point is there in a DC wall outlet? But at the same time, if you choose a low voltage, high-powered devices would require possibly hundreds of amps, which makes wiring very expensive.",
"My phone needs 5 volts DC to charge, my laptop needs 16.5 V, my little desk lamp uses 12 V, and that's just stuff that happens to be in my office right now. DC voltages are hard to convert from one voltage to another. If we did it your way, we'd need a different power outlet for every voltage."
],
"score": [
14,
5,
5,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jt1my | How do scientists isolate individual atoms? | I hear stuff about how they can supercool a tiny amount of one atom, or other experiments that require incredibly small amounts of material. How can they isolate these atoms for research in such small amounts? | Physics | explainlikeimfive | {
"a_id": [
"dr921jh"
],
"text": [
"Well, they don't do it individually. There is a field in Physics called Statistical Physics which concerns itself with the statistical study of particles. So when you supercool a particle, you actually supercool a massive amount of them. The same thing happens with protons in accelerators, like in CERN or Fermilab, when they collide beams of protons or electrons to discover new particles. The products of the collisions consist of billions of particles that have come from billions of colliding particles. An interesting way to supercool a gas is the following. You can use some lasers to hit the gas particles from one side and some other lasers to hit them from the opposite side. That way, you can practically immobilize them. This means that their kinetic energy drops and so does their temperature. Of course, you understand that this process does not happen to individual particles, but rather to a large amount of them. The movement and process can be sufficiently described by Statistical Physics. If you wish to learn more about Statistical Physics read about Bose-Einstein distribution and Fermi-Dirac distribution. The first concerns the behavior of bosons (like Z or W bosons) and the second concers the behavior of fermions (like the electron)."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jt769 | How did the Ural mountains form? | I never did geography properly in school, something to do with tectonic plates but there are non there. | Other | explainlikeimfive | {
"a_id": [
"dr90718",
"dr90ide"
],
"text": [
"The mountains were formed by the collision of the European and Asian continental plate, [like this]( URL_0 ), about 300 million years ago. That plate boundary isn't really active anymore.",
"there absolutely is 2 tectonic plates that collide there.....300 million years ago. now those plates are together and are part of the bigger Eurasian tectonic plate"
],
"score": [
8,
4
],
"text_urls": [
[
"http://skywalker.cochise.edu/wellerr/students/plate-borders/project_files/image012.jpg"
],
[]
]
} | [
"url"
] | [
"url"
] |
7jtjgt | Light can be blocked by anything opaque, but radio wave, microwave, x-ray, etc can easily penetrate our buildings, food, bodies, etc. What makes light different from them when they’re all made of photons. | Physics | explainlikeimfive | {
"a_id": [
"dr93jfx",
"dr93cb5",
"dr93101"
],
"text": [
"Visible light isn't special. Light of all kinds is generally blocked by *something*, but not all materials block all wavelengths. For example, infrared light is blocked by glass, but will pass through a black plastic garbage bag. X-rays will pass through most solid objects, but can be blocked by \"crystal\" glass with lead in it. Microwaves will pass through a block of wood, but will be reflected by a few inches of salt water. The details are quite complicated, having to do with the ability of electrons in the material to move around in response to different wavelengths / energy levels of light.",
"Think about a transparent blue sheet of plastic - it lets blue light through, but not other colors. Radio waves, x-rays, etc. are just different colors of light that our eyes aren't able to see. Building walls are opaque to our everyday colors, but transparent to these other colors. It can go the other way, too. For example, your car windshield is transparent to human-visible colors, but almost completely opaque to ultraviolet.",
"Photons are interesting because they behave as both a particle and a wave (it's weird, but just follow me here) Now, as a wave, that means that each photon has a wavelength (physical distance between peaks in the wave) and frequency (number of peaks that pass through a point in a given amount of time) The frequency (F) and wavelength (L) can be related in the equation c=FL, where c is the speed of light, which is equal for all photons Different materials can absorb or reflect light at different wavelengths, and what we see as opaque are just materials that are in the range that block visible light from passing through Other things can block other wavelengths in the same way. Microwave ovens have grids in front of them with holes smaller than the wavelength of a microwave but bigger than that of visible light, so it only blocks microwaves while letting us see inside"
],
"score": [
6,
3,
3
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jtnz7 | How do our bodies adapt to differences in temperatures? | Example, during the summer 20°C feels normal, however in the winter -10°C feels normal? Is there/what is the limit that the body can adapt to and why? | Biology | explainlikeimfive | {
"a_id": [
"dr99t1p"
],
"text": [
"Your body has many responses it can use to raise or lower your temperature. Sweating, shivering, etc. The part of your brain that controls when these happen is called the hypothalamus. When it detects a temperature lower than what it's been experiencing lately, it will make you shiver. Higher, and it will make you sweat. It's also responsible for the feeling of being too cold or too hot. But since it isn't the same temperature all day, all the time, the ability to get used to temperatures was useful."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jtyzy | How does signing online petitions affect change? | Usually a website asks you to fill out information about yourself and writes an email on your behalf. Do politicians take this seriously? | Other | explainlikeimfive | {
"a_id": [
"dr95vzb",
"dr95m37"
],
"text": [
"Online petitions are used to force companies to openly admit they are rejecting the thing that keep them alive: their customers. Most of the time, companies simply ignore them so there is no statement given. Other times, the petition is too big to ignore, and either the result is a well planned reason, or they cave and agree to make changes.",
"No, they don't. Unless you can outspend their donors, they're not going to listen to you. Everybody knew what side they were on before the issue came up in the first place. In fact, the majority of the work of figuring out who is on what side and lobbying the right people in the right amount is done before the issue ever publicly comes up. Even when Obama started the petition site direct to himself, all that ever happened by using it was that once you got to a certain number, he'd release a video explaining why he either agrees with you but can't do anything, or agrees with you and was already doing something before the petition started, or tells you you're wrong. To put it bluntly, as Sun Tzu said, the defeated warrior goes to war and then seeks to win, while the victorious warrior wins first, and then goes to war. Most of the time, by the time these issues ever come up in the public eye, whichever side will win has already won."
],
"score": [
8,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jug4n | How does smoking while being pregnant affect the baby? | Biology | explainlikeimfive | {
"a_id": [
"dr9a9pd",
"dr9bt41"
],
"text": [
"Smoking reduces the amount of oxygen that is available to a growing fetus, which it does in two different ways. First, the carbon monoxide in the cigarette smoke makes the blood less capable of carrying oxygen, and secondly, the nicotine acts to make blood vessels constrict and become narrower. The reduction in oxygen makes it harder for the fetus to develop.",
"It also causes birth defects. You see people all the time that are deformed by this without knowing. The ones I know about are pug noses, recessed chins, and short appendages (short fingers, short penis) Pug nose is not an inherited trait it's a birth defect. It also causes speech impediments."
],
"score": [
20,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7juzgp | How do some smells penetrate their containers? | Other | explainlikeimfive | {
"a_id": [
"dr9e05m"
],
"text": [
"Smells are chemical molecules. These molecules are small, and they can get through some materials and around very complicated paths made by folding or zip-locking bags. You also have to worry about transferring the molecules onto the outside of the container."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jvd2f | how do chickens generate the shell of an egg | Please note, I'm not asking how the chicken gets fertilized but rather how the biology of a chicken forms the crust of a shell | Biology | explainlikeimfive | {
"a_id": [
"dr9lx9f"
],
"text": [
"I'm not a expert on chickens, but I'll explain it how I understand it. If I happen to be wrong, I hope someone else can correct me and clear it up for you. The reproductive system of a hen is very much a kind of conveyor belt or assembly line. By the time the egg gets to the uterus (shell gland) in a hen, the whole egg has been formed in previous compartments and all that is left is to cover it in a shell. This is done by molecules of calcium carbonate that are in the body of the hen clumping together and crystallizing to form particles of calcite, which are then deposited on the surface of the egg. The individual calcite particles bond and crystallize together to become one big layer."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jvnyf | Why are faces the biggest factor in attractiveness? Is this consistent through cultures? through time? | faces are the most important part of initial attraction, at least in the developed world. What does the face convey that drives sexual selection to favor facial features even more than muscle mass or height? Is this consistent through cultures and time? What about other primates? do they also value facial features more than the other typical selection markers? | Biology | explainlikeimfive | {
"a_id": [
"dr9jelg"
],
"text": [
"A lot of genetic abnormalities express partially as craniofacial abnormalities, and these same abnormalities can indicate abnormalities with brain development or systemic abnormalities that reduce survival and general fitness."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jwc8q | Why does raw sea level data require adjustment? | I see stuff like [this]( URL_0 ) all the time regarding climate change: I am no skeptic and I am always inclined to side with scientists on this matter, but through no Googling can I find any explanation as to why adjustments take place or their methodologies. What is it about sea level measurement that makes it so complicated, that data needs to be adjusted? I don't even fully understand how we measure sea level. Thank you! | Physics | explainlikeimfive | {
"a_id": [
"dr9sn6p"
],
"text": [
"Here is a really good [paper from UNESCO about how sea level is determined]( URL_0 ) using a variety of techniques. Calibrations need to be made because everything is moving and it's not the same everywhere either. Wind and tides change the sea level at local levels both regularly and irregularly, that has to be accounted for. The ground is rising or sinking in different areas (rising in the Gulf of Bothna, sinking around New Orleans, for example), that has to be accounted for. The earth is spinning and water from the poles is pulled toward the equator, raising a more-or-less permanent bulge of water, that needs to be accounted for. Different local gravitational strengths means that the sea level is lower and higher in different areas of the world, that has to be accounted for. Also, as we use more and more different techniques to measure sea level those all need to be calibrated so that they are recording accurately, something that's extremely difficult to do. Recently we found out that a previous [miscalibration of satellite measurements had made sea level rise look lower than it actually has been]( URL_1 ). As a side note, don't use Fox as a source for anything environmental based. They constantly misreport things and show a very strong bias toward politically driven stories over data driven stories."
],
"score": [
3
],
"text_urls": [
[
"http://unesdoc.unesco.org/images/0012/001251/125129e.pdf",
"https://www.nature.com/news/satellite-snafu-masked-true-sea-level-rise-for-decades-1.22312"
]
]
} | [
"url"
] | [
"url"
] |
7jwh5w | When a body of water is frozen, how do the fish survive? | Biology | explainlikeimfive | {
"a_id": [
"dr9pj6u"
],
"text": [
"in a pond, the surface freezes first as it's closest to the cold air. the dirt in the ground is the last to freeze. liquid water that's in the middle is insulated from the cold air by the frozen ice. if the pond is sufficiently deep like 4-5ft, the bottom water never freezes because it's so insulated by the frozen ice on top of it and warmed by the ground below it."
],
"score": [
5
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jwiv6 | Why does audio recorded from speakers sound horrible, while audio recorded naturally (IRL) sound so much fuller and better? | Technology | explainlikeimfive | {
"a_id": [
"dr9ss34"
],
"text": [
"A similar question was asked in r/NoStupidQuestions with a great [answer]( URL_0 ) by u/Afflo. For the lazy: > If you record a speaker with someone's voice, it will sound bad. I'm assuming you aren't using studio grade speakers and studio grade microphones. > A speaker will have a frequency response that doesn't quite match reality. > A microphone (especially a cheap one) will have a frequency response that doesn't quite match reality. > When you play something recorded from the speaker, you are essentially layering three levels of degradation - the original speaker output, microphone input, and final speaker output... And this doesn't even consider the acoustics of the room. > If you take a picture of a picture of a picture of a pictures, you'll do the same - layer after layer of color and detail loss from printing and capture. Even the classic \"mirror facing a mirror\" will illustrate this - as you look through the infinite hall of mirrors, the reflection fades and distorts as you combine the imperfections over and over. > If you have a high quality studio and fine tuned equipment, the loss of fidelity can be managed to some extent. If that's the case, you're also probably an experienced audio engineer!"
],
"score": [
13
],
"text_urls": [
[
"https://www.reddit.com/r/NoStupidQuestions/comments/37ibfu/why_does_audio_from_a_speaker_sound_so_bad_when/crn9h3s/"
]
]
} | [
"url"
] | [
"url"
] |
|
7jwnw8 | Can someone explain the difference between MRI, fMRI, PET, and EEG scans? | A small description of each would be fine. I know they all examine the brain in some way, but I'm confused as to what each one does specifically. Need the info for a final exam in psych tomorrow. We are given scenarios and we must choose which type of test would be best. | Technology | explainlikeimfive | {
"a_id": [
"dr9s8cd",
"dr9rmnb"
],
"text": [
"MRI: Allows us to see brain tissue, nerves, bone, fluid etc. No radiation. If some dye is used, it can highlight certain things like blood vessels or certain diseases better. MRIs take longer than CT scans to perform and are better at looking at tissue generally while CTs are better at looking for blood. fMRI: f is for functional. It is primarily used for measuring brain activity by looking at which part of the brain blood is flowing to. Mostly used for research rather than clinical medicine. PET: Some radioactive material (usually a sugar) is injected into your bloodstream, when you are scanned, the parts where it's really bright are where this material has accumulated. Often used to look for cancer cos tumours need sugar to grow. EEG: Think of it as an ECG/EKG for your brain. When nerves fire/work, it gives off a small amount of electrical activity - this has a predictable pattern. Electrodes are placed at several points around your head and the electrical activity is picked by the machine and translated on to a strip of paper. We use EEGs to diagnose epilepsy. Technicians will often attempt to induce a fit using various equipment and methods and hope that we capture it on the machine.",
"fMRI and PET scans can be used to watch active processes in the body. You can watch blood flow and metabolic processes as they happen and change. PET scanners are mostly used for cancer imaging while fMRI scanners are mostly used for brain research, watching what parts of the brain activate via different stimulus. MRI scans are used for fixed high resolution images of soft tissue, the kind of tissue that doesn’t show up especially well on X-rays/CT scans. You’d use an MRI to accurately diagnose a brain stroke or soft tissue injury to a knee joint. EEG are direct measurements of electrical activity of the brain. You can use these to diagnose things like epilepsy."
],
"score": [
14,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jx3q4 | how does the human body differentiate between processed sugar & natural sugar | In order words, diabetics can eat natural sugar(apples, oranges, fruits etc) how does the body know the difference? | Biology | explainlikeimfive | {
"a_id": [
"dr9ux81"
],
"text": [
"The body doesn't - sugar is sugar. There's research that indicates that it can't even tell the difference between artificial sweetener and sugar. The thing is, most processed sugars are found in foods which digest quickly (soda and candy, for instance). The quicker your body metabolizes it, the quicker your blood sugar rises, which can be overwhelming for a diabetic. Natural sugars are found more in foods that take longer to metabolize, making the rise in blood sugar level more manageable/tolerable. Realistically, the sugar is all going to the same place eventually - 20 grams of sugar from a soda is the same as 20 grams of sugar from an apple. And on that note... a 12 oz (355 ml) soda has about 36 grams of sugar on average, while the average apple has about 19, or about half as much. A standard 43 gram Hershey's chocolate bar has 24 grams of sugar in it. EDIT: Long story short, the sugar's the same (slightly different compositions, since there's... different types, such as sucrose, glucose, lactose, fructose), so it does the same thing."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jxaat | At what scale are things so small that color doesn't apply? | Physics | explainlikeimfive | {
"a_id": [
"dr9wbxm",
"drado1e"
],
"text": [
"When they get smaller than about half the wavelengths of visible light. So about 200 nanometers or less",
"Some materials change color when they get small. This is from crystal interactions becoming too faint to cause color. For any material, when it is one half the wavelength of its color it will never have a color. This is because the atom cannot absorb or reflect any light. All wavelengths would pass through the material"
],
"score": [
55,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jxkp0 | If water conducts electricity, why does humidity *prevent* static shock? | Chemistry | explainlikeimfive | {
"a_id": [
"dr9yi66",
"dr9zi3b"
],
"text": [
"It allows the electrical charge to dissipate through the air. Rather than \"building up\" on an object to be \"released\" when it gets touched.",
"Humidity prevents static shock *because* water conducts electricity. In dry air, static charges build up until they find some way to *zap* to ground. In humid air static charges don't build up in the first place, because humid air is better able to carry the charge away. Humidity also dampens many of the processes that generate static electricity, for example by reducing the amount to which the air can move your hair, which normally generates a lot of static."
],
"score": [
8,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jxnov | Why/when do pinecones open up? | Biology | explainlikeimfive | {
"a_id": [
"dr9zypc"
],
"text": [
"> Why/when do pinecones open up? Pine cones open when it is warm and dry because it is a better time to spread pollen and seeds. Pine cones open in order to either produce pollen or receive pollen depending on if they are male or female cones."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jxung | Chlorone Trifluoride | How does it oxidize better than oxygen? I’d like to know the ins and outs of how it works and why it sets fire to everything. | Chemistry | explainlikeimfive | {
"a_id": [
"dra1dyl"
],
"text": [
"Oxidation basically means an atom gives electrons away to another atom which can bind them more tightly, and this difference in \"tightness\" results in a release of energy. The substance that has the tightly-binding atoms is called the oxidizer. It doesn't *have* to be Oxygen, but Oxygen is pretty good at it, and it's all around us, that's why the whole thing is named after it. But Chlorine Triflouride is even better at it than Oxygen, so it can release more energy, and it can oxidize stuff that is already oxidized by Oxygen - it just shoves out the Oxygen and binds the electrons even more tightly, so that there is still some energy to release. It's pretty dangerous and scary stuff. But then, so is Oxygen, we're just used to it being around all the time. I mean, look at the California wildfires: URL_0 and tell me that's not scary! Well, Oxygen did that."
],
"score": [
7
],
"text_urls": [
[
"https://localtvwreg.files.wordpress.com/2017/12/171206124100-02-ca-wildfire-405-exlarge-tease.jpg"
]
]
} | [
"url"
] | [
"url"
] |
7jxz4b | How come you can feel a faint sore throat or other symptom but then the next day after good rest it worsened? | Biology | explainlikeimfive | {
"a_id": [
"dra1r68"
],
"text": [
"By the time you are able to feel it, your immune system has lost the battle enough that you will get sick. With cold/flu -like illnesses, some symptoms are directly caused by the virus, but others are collateral damage from your body destroying the virus. The sore throat is actually caused by the viruses replicating inside your cells and then causing your cells to explode so they can escape and infect other cells. [See this diagram]( URL_0 ). So by the time there are enough of them for you to feel the surface layer of throat cells being a bit sore, it's too late!"
],
"score": [
65
],
"text_urls": [
[
"https://swh-826d.kxcdn.com/wp-content/uploads/2010/07/Viral-replication.gif"
]
]
} | [
"url"
] | [
"url"
] |
|
7jy0hm | why do experts say to grab vertical ropes when climbing nets? | Physics | explainlikeimfive | {
"a_id": [
"dra1ohh",
"drafcrb",
"drak2k1",
"dra6kl3",
"dra4abd"
],
"text": [
"Stability. The horizontal ropes will bend and cause a lot more sway in the net if you grab them. You can picture how a horizontal rope will bend to make a \"smile\" shape when you put your weight on it. The vertical rope will be put under tension and won't deform like this.",
"My brother was taught during his basic training (British army) When jumping to a climbing net don't try to grab the net with your hand but instead put your arms through the spaces in between the ropes and hug/hook the net with your arms.",
"2 reasons. Horizontal pieces deflect more than vertical pieces. Also, the soldier above you is standing on the horizontal pieces. If he slips, he's standing on your hand.",
"Also, the little finger has the tightest grip on the hand, so you have a firmer grip in a position where you can maximize the use of the little finger. (Source: often repeated by my various martial arts instructors with regard to holding various weapons, although I just checked online, and the internet is apparently arguing about whether it is true. My own experience backs it though. The other fingers just aren't as good at holding onto a slender object being jerked around.). Having your wrist twisted as happens in a horizontal position also decreases your strength. You can block an attack with much less effort if you are holding a sword vertically than if you are holding it horizontally. Logically that applies to ropes also.",
"It depends on how the rope ladder is configured. If the rope ladder is secured only at two points, the center of balance is directly in the center of the ladder. This means it is highly mass and prone to flipping/swaying. This means you need to keep your own center of mass directly along that center of balance to prevent swaying/flipping. The best way to do this is to use the verticle ropes, as it makes it easier for you to center yourself. If the rope net is configured so that it's secured at four points (as it should be), you don't really need to worry about this particular aspect, as the center of balance is the entire width of the rope ladder/net. As long as you keep three points of contact, you should be just fine. Here is a short video describing the first type of rope ladder/net that I described, and how it's used against you during the popular carnival game. It has lots of lines/models to show you the idea with visual influences. URL_0"
],
"score": [
163,
9,
8,
4,
4
],
"text_urls": [
[],
[],
[],
[],
[
"https://youtu.be/tk_ZlWJ3qJI?t=423"
]
]
} | [
"url"
] | [
"url"
] |
|
7jy4ll | How do the parasites that infect insect brains and such actually manipulate the host body's movements ? | I recently saw videos regarding like the fly that decapitates fire ant heads and the zombie ant fungus and I'm really curious what the parasite does in the brain of the host that makes them go or do what they want them to do. | Biology | explainlikeimfive | {
"a_id": [
"dra4gfg",
"draejg3",
"dra3h9x",
"dragvs7",
"drahs2i"
],
"text": [
"Screws with the hormone system (eg serotonin) . Doesn't make the ant do things, more it changes the way the ant behaves. EG. not make the ant climb, but make it really like the feel of sunlight so it goes and seeks that high place clear of shade.",
"Something worth pointing out: The parasite isn't intentionally manipulating anything. Essentially it is just performing its normal function of consuming resources and trying to spread, and it happens to be that these processes also happen to affect the host's behavior in a way that is helpful to furthering its lifecycle. There was likely another very close relative to the parasite that would cause the ant to just start convulsing in place or whatever, but that didn't provide any advantage so it just died out. Rabies in dogs is another example. Rabies makes its host confused and scared and in a lot of pain, and so it is more likely to bite or attack things next to it. It also just happens that rabies is spread pretty efficiently via biting. Some version of rabies that made a host shy away from others and die alone somewhere didn't spread very well, so it probably didn't compete very well.",
"Im no expert and not sure if it's the same thing as what you're asking but I read that fungus that forces the ant to go to a high place, gestation, then explodes actually takes control of the muscles. Meaning the ant would be conscious the entire time with no control of its body.",
"Coincidentally, I'm reading a book about parasites right now. The author mentions that scientists have proved that some parasites \"hack\" brain areas that produce the chemicals that cause the desired effect. For instance, some mice parasites force the mouse brain to produce dopamine, which in turn makes the mouse less fearful of cats and more prone to be killed by them. The parasite (in this case I think it was toxoplasmosis) needs a cat host to complete its life cycle.",
"It manipulates the emotions and motivation centers of the host. It does this by releasing proteins which activate certain classes of neurons and inhibiting other classes on neurons. For the [horse-hair worm]( URL_0 ) it totally inhibits the \"OK we have enough water\" response. That way the grasshopper goes to the stream, drinks a ton, and the parasite releases itself into the water to begin the infection cycle anew. The rabies virus has the opposite effect, it inhibits the \"Oh boy are we ever thirsty\" response by infecting the neurons that sense thirst."
],
"score": [
94,
29,
10,
5,
5
],
"text_urls": [
[],
[],
[],
[],
[
"https://www.wikiwand.com/en/Nematomorpha#/Description_and_biology"
]
]
} | [
"url"
] | [
"url"
] |
7jy7au | Truffles, what they are, and why they cost so much? | Other | explainlikeimfive | {
"a_id": [
"draf2ue",
"dra3zd5"
],
"text": [
"i hate to bust balls, but all of the current answers are incorrect. truffles are not a mushroom. they can be farmed. dogs are better than pigs for locating truffles. truffles are a fungus that grow on the roots of trees where the fungus is in a symbiotic relationship with the tree (think bird cleaning a crocodile's teeth). the fungus helps the tree find water in soil that is difficult to grow in, and the tree gives some of its sap to the fungus. there are broadly two types of truffles eaten by humans, white and black. white are usually found in the balkans and italy, black usually in the southern half of france (this is very broad btw). people inoculate tree roots of oak (where they naturally grow) as well as hazelnut (filbert) trees to try to start them growing. in my amateur opinion, the trees are not struggling for water, so the symbiotic relationship does not need to form, and that is why they have difficulty growing them. the soils they naturally form in are usually drier and sandier, but in old growth forests. pigs were originally used to find them because they used to dig them up as people let their pigs roam in the forest. the scent is similar to male boars, so female pigs in heat would go crazy for them. as you can imagine, having a horny female pig digging up something that smells like male pig balls is difficult to control. dogs have a much better sense of smell, and are easier to train, so they are used. they're so expensive because they're rare, they take a lot of labor to gather, spoil quickly, and a little goes a long way. *i've been researching truffles for years, i'd like to have a truffle farm when i retire, so i've been researching them for years. if you have any other questions, let me know.",
"Truffles are a type of mushroom that have a very distinct flavor that is highly sought after by chefs The reason they are so expensive is that they are very difficult to find. They cannot be farmed (at any large scale rate, anyways), and the only way to find them is with pigs in certain swampy wooded areas."
],
"score": [
30,
22
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7jyfaa | Why does adding a resistor in a parallel circuit reduce the resistance of he whole circuit? | How does his work? | Physics | explainlikeimfive | {
"a_id": [
"dra4szq",
"dra6big"
],
"text": [
"Think of it like a highway. If you add an extra lane, even if it only allows one more car through every minute, it is allowing more cars to go through than it would have without it. Similarly, the extra resistor adds an extra path for electrons to travel through without restricting the original path.",
"That question is exactly equivalent to \"Why does adding a conductor in a parallel circuit increase the conductance of the whole circuit?\" When you re-state the question that way it becomes more intuitive"
],
"score": [
19,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jysso | how was Russia able to redirect all cloud traffic through their country from multiple sources like Apple, Microsoft... Etc. Wouldn't they have to compromise all the individual systems (like apple) to do this? What are the broader implications of this? | I have so many questions that I don't even know where to start asking or if I'm even asking the most important questions. | Technology | explainlikeimfive | {
"a_id": [
"dra8xtf",
"drajtrx",
"drak8ni",
"dra8my0",
"dra9exc",
"dratn47",
"drb2pfa",
"draswcr",
"draxgsa",
"drb25tw",
"dravdh6",
"draxnzj",
"drbgplo",
"drbb8sa"
],
"text": [
"The way your computer knows where to send your network packages is through something called a \"routing table\", which is basically a mapping of networks your computer knows about, and the corresponding physical ports on your computer. On your home computer this usually has only one entry: \"send all packages through my wifi card\". That will and up at your home router, which has a slightly more complicated routing table with two entries: * send all packages addressed to the local network out through the wifi (this is how you access other computers in your house) * send all other packages out through the internet connection to the ISP At the ISP the package that you send to Apple, is processed by their router. That router is much larger and there might be very many of them, so their routing table is much much larger. The ISP might have a youtube server right in their own datacenter to help speed up videos, so there is an entry in the routing table about that, but for example to reach Apple, it might send it to a different ISP, who knows yet another ISP who knows where the Apple server is located. Because this is very complex, these tables aren't configured manually, but they use something called the [\"Border gateway Protocol\"]( URL_0 ). That basically works by Apple sending out a message to all the routers it, in turn, knows about, saying: > Hey guys! I am Apple and please send all network packages that should go to Apple through this connection here: ::ROUTING INFORMATION:: Turns out, this message is not authenticated in any way, so anyone who is part of that network of routers can send such a message with false information. It's amazing how fragile some of these things are.",
"The Internet is a series of tubes. The Russians tricked the tube conductors to take alternate paths to their destinations. The tube conductors will take orders from anyone without verifying their authenticity.",
"They way traffic is routed is quite simple: you never really know how to reach someone but you always know who knows how to reach someone. So your computer ask your router Your router ask your isp Your isp ask someone else ... and this can go one a few times before your packet reach its destination. The thing is: the way routers know where to send the information is through word of mouth. If someone says he knows how to reach someone else, you trust him no matter what. Even better if they say they ARE YouTube.",
"They used a protocol that tells routers how to get from network A to network B to tell them to go through the Russian network. The network operators generally don't filter this kind of request because it's mostly used for legitimate purposes like when someone's network crashed or is overloaded. See [Wikipedia]( URL_1 ) if you want to read up about how it works. [This site]( URL_0 ) has a fairly easy to understand explanation.",
"El15: The internet is a series of interconnected networks. Each network trusts all the others to behave and listens when they broadcast instructions. These instructions tell the rest of the networks the directions to get to their destinations. So any network operator that is connected to the internet and has addresses from their regional ip address authority and has the right equipment can broadcast these instructions that all the other networks implement once heard. The broad implications are complicated. So far as i know incidents like these have been accidents. A network engineer made a typo or equipment went shit. but there's a good chance nation states use the method to intercept traffic and information on a selective basis. Say you are in new Zealand and one of the powerful nation states has an interest in your signals. You have collection nodes scattered across the globe tapped into fibre at various important points but maybe not everywhere. If You are a nation state actor you may have compromised access to an is in Brazil where you issue routing instructions telling the whole internet to change the path for a group of ip addresses. Then this route is collected and fed into your sigint system.",
"The first thing you have to understand is that a significant amount of what was claimed is total propaganda and simply is not true. I say this both as an American who is fed up with our media and politics as well as an I.T. professional with over 20 years experience who works in the US aerospace industry. When you say “all cloud traffic” you’re basically saying “all internet traffic” sent/received from these companies. It’s simply not the case. Even if it were, the state of IT security at these places is going to include encryption, RSA tokens - so even if someone could get the traffic it’s not going to be a trivial matter to decrypt it or have it in a useful form.",
"What are you even talking about? What did the Russians do?",
"Imagine traffic is like mail that gets delivered to your house. Any local mail in your town stays in your town and is delivered based on a set of street addresses right? What about when your mail goes further to other post offices... the mail has a zip code and then it's delivered to the post office at that zip code and distributed. What if someone could just tell the post office \" I am zip code 90210, any mail for that zip code should come to me\". That's basically how border gateway protocol works at the business level. A person sends a bgp advertisement saying, any traffic for Apple should go here\", and the internet routers believe it. In our mail scenario, this entity in Russia has said \" I'm zip code 90210\" packages started coming to Russia instead of 90210 Beverly hills , then Russia opens the mail, reads it, packages it back up and sends it to the real destination. Believe it or not, internet routers are that trusting in certain circumstances. Now the person in Beverly hills 90210 receives the letter but it originally had a wax seal (think of this as ssl encryption) on it that is now broken. Senders and receivers of this mail will know it didn't come from a reputable source, but governments have ways of faking the seal that normal people do not (hijacked certificates or trusted certificates in a computer certificate store) this could mean packages can be sent back and forth and people assume they aren't tampered with, when in fact they are. Another thing to take into consideration is this.. If the package isn't delivered, the post office will instantly fix the issue.. meaning this is tough to keep going for any significant amount of time",
"[China did this to 15 % of the world's Internet traffic in 2010 for 18 min. Russia used the same method.]( URL_0 )",
"The article I read said the data was routed to Russia, this doesn't mean the Russian's did it. Like the old saying is around here \"you don't shit on your own doorstep\".",
"The system that allows your computer to translate a website address (ex: \" URL_0 \") into an IP address that it can actually connect to is basically set up like Wikipedia. Anybody can suggest edits to it, but generally speaking, any outlying crazy edits will get quickly overwritten by the majority. These tables are replicated by word of mouth between computers, but there is very little actual verification. The system basically runs on the premise that the majority of computers, in aggregate, isn't wrong. And most of the time, this is a safe assumption. Similar to a Wikipedia edit-bomb campaign though, it is possible for a really dedicated actor to overwhelm the system by telling a critical mass of computers to update their routing tables to point to a false location. This can be done strategically at the choke-points of interconnected networks, like those between countries, where a lot of this \"word of mouth\" information comes through. It's still really hard to pull off for long -- the equivalent of editing the Wikipedia page for \"The United States\" to point to \"Bangladesh\" and getting it to stick, but it can be done for short periods of time.",
"First, there are AS's. Second, there is BGP protocol. AS's decide their routing tables based on a number of factors, such as reachbility, hop count, etc. Reachability and hop count are provided via BGP. In essence, any AS can broadcast to all other AS that they can reach certain address. This is what the Russians did. Yes, the system is not secure, but it was never designed to be.",
"I'm late but I have a simple answer to share. Imagine you need to go somewhere and you're not sure how to get there. You'd probably pull up Google Maps and follow the directions it gives. The Internet is the same way. Data is delivered from one place to another by following mapping directions from routing protocols. Now, imagine Google Maps freaked out one day, and everyone that tried to use it was given directions that sent them all through one intersection in one town. Tons of people would find their way through that place. This is essentially what happened in the Internet. The routing protocols freaked out because bad data was injected into it, which screwed up the directions given for data to be delivered. As a result, a ton of traffic was sent through one system in Russia.",
"The internet is not one big interconnected system like a spiderweb. It’s a collection of tens of thousands of separate autonomous systems. Each AS is like a separate country. They each have peering agreements, like treaties, to dictate how traffic flows between their system. For example, Comcast’s Pennsylvania AS might have an agreement to share traffic freely over a certain link with Verizon FiOs, or Harvard’s network, or even Vodafone. There are tens of thousands of these systems. And you don’t automatically know where a certain IP address is over the whole internet. That’s why each AS advertised ip prefixes. That’s how you know which actual web server has an up address you’re trying to find. It works over a system called BGP. And it tries to find the best route from you to your destination. But BGP is surprisingly easy to fool. It trusts advertisements from anyone. If you’re in New York trying to reach a Russian Bitcoin site, that would normally be a long series of hops. But an evil rogue AS in Pennsylvania with a malicious server could advertise the same up address as the bitcoin site. Since it’s a shorter path, and since there’s no real security with BGP, your computer will go to the server in Pennsylvania instead. So basically, it’s like giving wrong directions to a tourist in a world where everyone assumes people to give correct directions. It’s surprisingly easy."
],
"score": [
5698,
445,
201,
28,
19,
14,
8,
8,
7,
5,
5,
3,
3,
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Border_Gateway_Protocol"
],
[],
[],
[
"http://www.enterprisenetworkingplanet.com/netsp/article.php/3615896/Networking-101-Understanding-BGP-Routing.htm",
"https://en.wikipedia.org/wiki/Border_Gateway_Protocol"
],
[],
[],
[],
[],
[
"https://arstechnica.com/information-technology/2010/11/how-china-swallowed-15-of-net-traffic-for-18-minutes/"
],
[],
[
"www.google.com"
],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jyv60 | Why aren't there public referendums/votes more frequently? | How often does your country hold referendums? | Other | explainlikeimfive | {
"a_id": [
"dra7ofs",
"dra97fh"
],
"text": [
"They are wildly expensive. When one US state holds one special election with just one question, the typical cost is in the millions of dollars. In addition, most citizens don't take the time to participate, nor to become well-informed on the issues. E-voting, if people felt it was safe enough, could drive down the costs and increase participation, but probably would do little about making people study the issues before voting.",
"They are expensive and unless the issue is extremely controversial, turn out is generally very low. Also, a lot of people don't want frequent referendums, the entire point of voting for a representative is to not vote on every single thing yourself."
],
"score": [
9,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jyysy | Why do programs sometimes refuse to close? | You know, when the program's window greys out and it gives you an error message, but won't close even through forcing it with Task Manager or alt-f4. | Technology | explainlikeimfive | {
"a_id": [
"dra8cd2",
"draet47"
],
"text": [
"It could be caused by a blocked process waiting to acquire a 'resource' held by another process. Until this resource is acquired, the program wont be executing a terminate process. Same as deadlock situation.",
"Operating system has varying ways to try killing a process. Most of them can be \"captured\" by the program itself, so if operating system sends a \"shut down\" signal, program can intercept it and try to close it down by itself, allowing it to save data and otherwise do cleanup on itself so it's less of a crash and more like program closing. Which is a problem when program somewhy gets stuck in some logical loop that prevents it from even processing that order it intercepted. So it's in some logical loop, maybe counting to one trillion, or maybe waiting for some event that never happens, and the intercepted command just waits to be processed after. And it never will. In task manager you have some special option called \"kill the process\", which cannot be intercepted by the program itself. It simpy frees the memory program was using and removes the program from the list of running programs. Anything you were doing is gone, and any data the program was handling may be corrupted as a result."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jz4z7 | How do doctors determine the time of death of a person? | Also, how accurate is the estimated time? | Biology | explainlikeimfive | {
"a_id": [
"dra9ehr"
],
"text": [
"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [ELI5: How can CSI tell the exact time of death ]( URL_1 ) ^(_6 comments_) 1. [ELI5: How accurate can coroner determine time of death? ]( URL_0 ) ^(_2 comments_) 1. [ELI5:How do forensic scientists determine the cause of death? ]( URL_2 ) ^(_2 comments_)"
],
"score": [
5
],
"text_urls": [
[
"https://www.reddit.com/r/explainlikeimfive/comments/5kl0jc/eli5_how_accurate_can_coroner_determine_time_of/",
"https://www.reddit.com/r/explainlikeimfive/comments/483s01/eli5_how_can_csi_tell_the_exact_time_of_death/",
"https://www.reddit.com/r/explainlikeimfive/comments/4uka91/eli5how_do_forensic_scientists_determine_the/"
]
]
} | [
"url"
] | [
"url"
] |
7jz7pr | What happens to information and media (texts,apps,videos etc...)on your phone when they are scrolled out of sight? | Technology | explainlikeimfive | {
"a_id": [
"draaejh"
],
"text": [
"They are kept in the device's RAM as you use the app, so that when you scroll back up, they are instantly available. Some apps may run out of RAM or otherwise optimize to save it, so the data will be erased from the RAM and lost, thus when you scroll back up, then it must re-load the data from the internet."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jzjc7 | Why was the US effort to rehabilitate Japan's economy after WW2 such a huge success? | Plus why did the US felt responsible to aid Japan after WW2 and why didn't US do the same for other countries? | Economics | explainlikeimfive | {
"a_id": [
"dracrh9",
"drapmk5",
"dratum6",
"drblxoz"
],
"text": [
"Economics is not my subject, but it is just of note that the economic recovery did not really succeed until the 1960s, at which point Japan experienced its \"economic miracle\" that lasted until the 1990s. US aid is only part of that story, but the US did aid in the initial rebuilding of Japan, gave Japan favorable trade policies, and helped them re-organize their economy. As for why the US did it, it is because the US wanted Japan to be its major, permanent ally in the Far East, especially with a perceived growing threat from the USSR. The Chinese Revolution in 1949, and the Korean War in 1950, further emphasized the usefulness and importance of having a strong ally (and the host of several military bases) over there. The US did do such a thing for Europe, to a degree. The Marshall Plan was explicitly a plan to help rebuild Europe and stimulate its economic development, so that it would not become fertile ground for extremist, illiberal ideologies like fascism and, especially, communism. But other than West Germany, the US did not occupy European countries to the same extent that it did Japan, so its influence was not as radical as it was in the countries where it stayed and ran things for a decade. One thing you have to remember is that the Americans were desperate to avoid a situation like the end of World War I, where punitive measures by the victors meant that the losers were in economic shambles. This was seen then (and still is today) as plating the seeds of Nazism, Communism, and World War II in Europe. So instead of just vanquishing enemies, the Allies wanted to make them into future friends, especially with the Soviet Union turning all of the states it had liberated from the Nazis and Japanese into vassal states of their own.",
"Partly because Japan was already going in that direction before the war. In the mid 19th Century, US gunboats showed Japan how backward they were, which lead to a massive modernization and westernization movement. One of the things other world powers had that Japan did not were colonies, so Japan made some out of Korea and Manchuria. Britain and France weren't crazy about this and felt Japan was a threat to their colonies in the region, and imposed an embargo. That was the primary reason for Japan's participation in World War II. Japan had already been pushing hard to become a Western-style world power, and the post-war reconstruction continued to build on this momentum. > why didn't US do the same for other countries? The Marshall Plan spent over $100 billion in today's dollars to rebuild European countries hurt by the war, with most of it going to the UK, France, West Germany, and Italy.",
"Because of the efforts of the Japanese people themselves. Same for Europe and the Marshall plan. The US tried to do the same thing in Iraq, but all the Iraqi's wanted to do was kill each other. It comes down to the cultures involved.",
"This first part is my opinion, but I think the success of US and Japanese diplomacy after WW2 was directly related to the success of General McArthur and US policy to help rebuild. This part is factual. The country was in shambles at the end of the war. Infrastructure was ruined, agricultural capacity was low and people were starving. The nation was in ruins because they went all out, win or die, and saved nothing for rebuilding. Lets imagine for a second what would have happened if we immediately turned Japan back over to their own control after arresting and trials for the war criminals. People want to survive, and it would have been a matter of time before resentment and anger turned back into armed aggression. Not to mention that the next generation of Japanese would have grown up with severe hardships and many of them would have been denied the educations they would need to rebuild their country. But the US didn't do that. They made a play at stabilizing Japan, and putting laws and infrastructure in place that would allow the next generation to continue the work of the first. Schools were rebuilt, children went to school instead of farming to feed their families or work in a factory, they had water, electricity, they studied and joined the adult world with all of the knowledge of any civilized society, and instead of becoming a drain on the world, they became a resource Japan could rely on to continue improving and rebuilding. As relations with Japan stabilized over several decades, and the war time resentments died out, we formed an alliance that benefited both nations. It placed US interests in a part of the world they had not been a part of before, and a reminder to China, The Soviets, and later, North Korea, that conflict would have consequences. Because Japan was stripped of it's military, it lost it's ability to self defend, and so the US and other allies had to be a surrogate defense force. Later Japan developed their own self defense force which had a mission similar to the National Guard and Coast Guard, to maintain peace, defend it's borders, and protect itself from civil unrest. As for why the US didn't do this in other countries, that is a very good question. The major conflicts that followed were both in Asia, the Korean war, and the Vietnam war, both almost proxy wars between the US and the USSR. The Korean war never ended and there was no victory or defeat so there was no way to rebuild North Korea, although South Korea and the US share good ties. The Vietnam war was a loss, and the South lost and the US fled the country in the final days of the war. So again, no chance to rebuild. And arguably the Vietnamese have done a fine job of rebuilding their own country and the VC turned out not to be the boogeymen everybody feared. So that leaves Iraq and Afghanistan. I sincerely wish we had done more to help them re-establish schools and basic infrastructure, and done more to work with all of the countries of the Middle East to stop the problem of hardcore militants. If the people in war torn nations have roofs over their heads, education so that they grow wise to the world and make better decisions, but also to develop skills that will help them rebuild their countries, and give them hope of improving their lives, I think the fertile soil for militants will turn bitter, and people would be less desperate and easy to manipulate through fear. Opinion time again. Human beings are predators. We eat meat, we have forward facing eyes, and our instincts for survival lead to violence. Deny people safety, shelter, and a future, and they will survive the only way they can, by becoming hard and violent. Imagine a country is like a person. If someones house burns down, and they lose everything, and nobody steps in to help them, and they are not able to help themselves, what's going to happen? They might become homeless, and become a drain on society while living a hellish life. They might turn to crime out of need and resentment for peoples callousness. If you treat a person like an animal, they can act like an animal. But if you help them get back on their feet, you give them the chance for a better future, society gains as the person gains. They become a resource rather than a problem."
],
"score": [
36,
6,
4,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7jzkaz | medical prices vs competition | How have medical expenses not followed the laws of competition like most other industries in our society (America)? With how many hospitals/drug makers there are you’d think prices would decrease, not the other way around? | Economics | explainlikeimfive | {
"a_id": [
"dradqt6"
],
"text": [
"Medical treatment have inelastic demand. This means that the price for medical treatments do not affect the demand for them. This makes sense, because the consumer have no bargaining power whatsoever. If there's a pill you need to take to live, and it costs $1, you will pay $1. If it suddenly increase to $100, you will still pay $100, or you die. You simply cannot successfully bargain when your life is literally on the line."
],
"score": [
13
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7jzv23 | Why do phone games uses multiple in-game currencies? Sometimes a more valuable currency is used to encourage you to spend real money but are there other reasons? | Economics | explainlikeimfive | {
"a_id": [
"draep48"
],
"text": [
"\"Sometimes a more valuable currency is used to encourage you to spend real money but are there other reasons?\" Nope, you got it right there."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7jzxe1 | What causes a brain for someone with a certain condition, to get “stuck” at a mental age much lower than their actual age? | Biology | explainlikeimfive | {
"a_id": [
"drajmr4",
"drbh9d0"
],
"text": [
"When someone has a disorder that causes them to have diminished mental capacity, what's going on isn't really that they are 'stuck' at that age. Someone who might be described as \"having the mental capacity of an 8 year old\" does not actually have the mind of an 8 year old. This is simply a convenient, simplified way of expressing how much mental capacity someone has. It's easy for everyone to understand, because most people have at least an approximate idea of how much mental capacity an 8 year old has. Disorders that cause diminished mental capacity usually do so because the development of the brain is impaired. But development of the brain being impaired doesn't mean that the brain is \"stuck\" at a certain developmental stage. Consider a physical developmental abnormality like spina bifida. A person with spina bifida definitely has reduced physical capacity compared to an unimpaired person of the same age. Their body is clearly not 'stuck' at a younger developmental age, however, it simply has developed abnormally in a way that causes them to be impaired. Developmental disorders that affect mental capacity are no different. The \"mind of an X-year-old\" thing is just a way of trying to express how severe the impairment is.",
"\"Mental Age\" is somewhat of an old statistic from the Stanford-Binet Intelligence Scale developed for the sake of identifying children who may need additional help. If you had a certain test rated out of 100, and you expected 8-year-olds to get 80/100 out of it, then 80/100 is your standard for 8-year-olds. If you expect 6-year-olds to get 60/100 on it, then 60/100 is your standard for 6-year-olds. So let's say an 8-year-old comes in and gets 60 on your test. You would say they have a \"chronological age\" of 8, and a \"mental age\" of 6, suggesting they're behind their peers. This is all mental age ever meant--it was used to identify students who were intellectually delayed. Now, we treat these topics with more sophistication than a singular statistic--we break intelligence down into many different subcategories to identify where someone might be lacking."
],
"score": [
22,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7k0gc5 | Is the heart a muscle or organ and why? | Biology | explainlikeimfive | {
"a_id": [
"drajouw",
"draka8k"
],
"text": [
"It is both. Medically, each muscle is considered to be a discrete organ of the body; your bicep is as much an organ as your liver.",
"An organ is a collection of tissues joined in a structural unit to serve a common function. The heart has specialized muscle, myocardium, that allows it to beat for extended periods of time without fatiguing. In addition to the myocardium, there are valves, pacemaker cells, structural tissue, arteries, veins, and a protective pericardial sac among other structures. So while the majority of the heart is made up of specialized muscle, it is not exclusively just a singular muscle."
],
"score": [
12,
5
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7k0q1b | How are cabinet members chosen? | Is it up to the discretion of the president to do this or is there a longer process? If it is up to just the president, how is this allowable in terms of a constitutional government? | Other | explainlikeimfive | {
"a_id": [
"dralx04"
],
"text": [
"Per the law, the POTUS nominates the member and then that member is confirmed by the Senate. That is all that is actually legally required. In practice, the POTUS will have a much longer vetting process run by various staffers or will dole out these nominations as repayment for political favors. It is allowable because that is how the Constitution lays out the process in the Appointments Clause (Article II, Section 2, Clause 2): > He [the President] ... shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7k0sgq | Why are books still cited by page number when there are different editions of the book where the pages vary? | Other | explainlikeimfive | {
"a_id": [
"dramhz8",
"dramlwg"
],
"text": [
"Because you specify the edition and publication version along with the page number. It is still by far the easiest way to refer to a location in a book of text.",
"You have to cite *something* in a large book to give readers a starting point. Books won't always have chapters or sections, but they all have pages. The citation will (or at least should) include the version number and/or publication date if that's an issue. Authors may not be aware that the book they're citing exists in other formats, so mistakes happen."
],
"score": [
21,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7k0vhj | How does the body know how much blood it needs to regenerate? | Biology | explainlikeimfive | {
"a_id": [
"draps5n"
],
"text": [
"Your kidney has sensors for oxygen. Most oxygen in the blood. is carried in the red blood cells. If the oxygen readings fall below a certain level, the kidney produces a proportional amount of a hormone (Erythropoetin). This hormone causes the bone marrow to make more red blood cells (it also encourages them to make more hemoglobin, which is what carries oxygen in those cells). As more RBC's are made, the oxygenation improves and less hormone is released. As for the rest of your blood, in other parts of the kidney there are cells that measure fluid pressure which release another hormone (renin) which leads to a chain reaction of hormone interactions which result in changes that increase fluid volume."
],
"score": [
24
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7k1l9m | What are gas giants and why can't we land in them? | **Edit** Thanks for all the answers, that clarified alot | Physics | explainlikeimfive | {
"a_id": [
"dratrxj"
],
"text": [
"Exactly what it says on the tin: they are giant balls of gas. We can't land on them because: they are giant balls of gas. Even theoretical models that permit them to have a surface of some kind at the center, it would be under such conditions (temperatures, pressures) that no man-made craft could reach it and survive."
],
"score": [
13
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7k1yx5 | Why does chili leave a stain on plastic bowls when other foods don't? | You know, that orangeish ring around the top level of the microwave safe plastic dish that you reheated your chili in. Why? | Chemistry | explainlikeimfive | {
"a_id": [
"draxoai"
],
"text": [
"Plastic is slightly porous, which means it has tiny holes at the microscopic level that allows certain molecules to squeeze into. One of the compounds in tomato sauce is [Lycopene]( URL_0 ), which is the right size and polarity to fit into those pores. Lycopene is bright red, which is why the plastic changes colors. Lycopene is non-polar so can't be easily washed away by water, but bleach is pretty effective at removing it."
],
"score": [
16
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Lycopene#Staining_and_removal"
]
]
} | [
"url"
] | [
"url"
] |
7k25pf | Why is it much easier to fall asleep during an afternoon nap? | Biology | explainlikeimfive | {
"a_id": [
"drb0u69"
],
"text": [
"I thought i was the only one who got those feelings. I love watching TV when that feeling sets it. You close your eyes sometimes and wake up in the future."
],
"score": [
8
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.