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nm23rv | Why is beef the only staple meat with true intramuscular fat marbling? | Pork has a fat cap, poultry has subcutaneous fat, and seafood fat is oil that is dispersed through the meat. Why is beef the only one that we see the fat inside the muscle? | Biology | explainlikeimfive | {
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"It isn't, you're just not looking at the right cuts of meat. Certain parts of a pig have marbling, certain parts of a cow don't, certain parts of fish do, etc, etc. It just depends on the quality of your meat and which parts of the animal you're looking at. A quick Google search of \"marbled pork\" or \"marbled fish\" or whatever will show you what they look like.",
"Pork shoulder is marbled, only oily fish have oil throughout their body, non-oily fish have it all in one place (like cod hence why cod liver oil is a commonly found supplement in shops). Lamb is marbled too , especially in the shoulder.",
"Weird question, but does human meat have fat marbling?",
"Environment plays a part. If you look at bison meat, especially those from the far north, there is virtually zero marbling, and the fat is concentrated on the cuts that come from the \"outer\" parts of the animal. The fat is an insulator for these animals. Similarly Arctic Char will be fatty towards the scales.",
"Wtf why did this become a cannibalism thread??"
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nm2bwy | How do you calculate if a color is warm or cool? | Or, how do you figure out if a certain color is warm or cool? Using a rainbow scale? | Other | explainlikeimfive | {
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"If it’s more towards yellow/red then it’s warm, if it’s tinted towards blue then it’s cool. For tones of white you can calculate it using the colour temperature, 5500K is generally neutral white with lower being warm and higher being cool but these are relative terms as well.",
"Colors are typically defined by the light the reflect back into your eye- lower frequency of reflection- we perceive them as “cool”, higher, we perceive them as “warm”"
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nm2o21 | How logs (logarithm) works | Mathematics | explainlikeimfive | {
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"The logarithm of a number is what power you'd need to raise a base number to in order to get the original number back. There are two commonly used bases, base 10 (the same decimal system we always use) and \"natural\" logarithms, which use the constant e (2.718...) as its base. To give an example, the number 1000 in base 10 logarithms is 3, because 10 raised to the power 3 is 1000.",
"One way to start thinking about it is by comparing the linear and logarithmic scales. In the linear scale, a fixed distance is the same as ADDING a number (e.g., if you go two steps further, you're +2). In the logarithmic scale, a fixed distance is the same as MULTIPLYING by a number (e.g., if you go two steps further, you're \\*2). See the images at [ URL_0 ]( URL_0 ). There are lots of examples of when the log scale better reflects real life, but one common example is unconstrained cell growth. Let's assume that 100 of whatever we are looking grows at a rate that you would get 150 after a day. If that was a linear scale, starting with 1,000,000 would give you 1,000,050, which is wrong, but the logarithmic scale shows that the every cell splits at the same rate and you'd have 1,500,000. The logarithm (and its inverse, the exponent) are how this relationship is written down. Edit: switched from stocks to cells because it's more visual."
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nm2od0 | - How do heat inverters work? | I’ve just had a heat inverter pump installed for an outside pool. Apparently if the air temp is above 4 degrees it can warm the water even if the water is already say 20 degrees and the air is only 6. What black magic trickery is this? | Physics | explainlikeimfive | {
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"This is the same heat pump technology that you find in refrigerators, freezers and air conditions, it is just turned the other way around. When you change pressure in a gas you also change its temperature. So increasing the pressure using a compressor will increase the temperature and decreasing the pressure by letting it leak through a small valve decreases its temperature back down again. So the gas inside the heat pump will be compressed and therefore heated to above 20 degrees so that it can be used to heat the water. And then the pressure is decreased so the gas gets cooled to under 6 degrees so that the air will heat it up."
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nm2ps5 | How can digital currency cause blackouts? | Technology | explainlikeimfive | {
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"Bitcoin 'mining' can put a huge strain on a local powergrid, as people are trying to power more and more energy-hungry mining rigs. Basically crypto mining rigs are supercomputers that just try to solve math problems over and over again extremely quickly and at extremely high volumes. Enough people doing this on the same grid can pull too much power and cause a blackout."
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nm2rej | What gives oil it's frying property and are there any other liquid substitutes for it? | Chemistry | explainlikeimfive | {
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"High boiling point, i.e. not evaporating at the temperatures required to get your stuff fried. As a bonus, it also isn’t toxic, like mercury for instance (356.9 C), which makes it actually suitable for frying something fit for human consumption.",
"Frying mainly does three things: * It drives off water by evaporating it * It heats the surface of the food to a temperature that allows browning to occur (Maillard reaction) * It replaces some of the water inside the food with fat For the first two you just need something that has a higher boiling point than water, but since whatever you're frying in also becomes part of the food, that doesn't really leave many choices.",
"A liquid that is suitable for frying must have the following properties, a. Must be able to remain liquid at a wide range of temperature (on the higher side too). Meaning, preferably, it must be liquid ~~from room temperature to~~ between 150 deg C to about 200 deg C. Actual frying is done around 180 deg C + / - 10 degrees - in most cases. b. It must not vapourise atleast a few tens of degrees higher than the frying temperature it will be used for. c. It must be non toxic at room temperature or high temperature. d. It must not react with the food being fried (and impart unpleasant taste / flavor / smell / color) to it. Infact it must add a pleasant taste / flavor to the food that is fried. e. It must be reusable after cooling down - meaning it must not go through any irreversible change in itself due to heating and cooling cycles Animal and Vegetable origin fats fulfill almost all the above criteria - hence they are most suitable for frying."
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nm3gyi | During an extreme sitatuation (Country dissolves while on seas) What happens if a Vessel’s flag nation becomes invalid? Is there a merchant flag used in these types of sitatuations? | Other | explainlikeimfive | {
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"If your country of registry ceases to exist while you are at sea, you are now a stateless vessel until you register with another country As a stateless vessel you are subject to all countries laws and can be boarded by any country.",
"Subjectively, and to somewhat answer your question. John Paul Jones, a Naval Officer with the American Revolutionary Army during the war showed up at a Dutch port without his Identifying flag seeing as it was lost in battle. The Dutch proceeded to make an [approximation]( URL_0 ) based on Ben Franklin's Design and they recognized it as a legal Maritime flag.",
"Just a guess, because I work in the industry and I was curious, but I'm pretty sure you're asking a question only lawyers would know the answer to. So far as I can tell, there's no precedent for a member state leaving the IMO, which is a far less extreme version of what you're asking. There's even less precedent for states straight up dissolving, at least after 1948 when the IMO was established. Most states tend to just change (the USSR becoming Russia, f.e) but to my knowledge there are no nations who were in the IMO but aren't any longer. My best guess, based on my work knowledge? The vessel would be placed under indefinite detention in whatever port it visited next while a bunch of lawyers from around the world argue about the best course of action. The IMO do have things to say about abandoned seafarers, but I imagine you'd be more likely to be treated as a Stateless person over anything to do with your seafarer state status. All of this being said however, foreign going vessels (so anything leaving the EEZ of your country, I believe) have to be registered with an IMO code. It's not like the state dissolving would mean you're completely unknown and can suddenly become a pirate because your vessel is now unregistered. & #x200B; TL;DR - There's no precedent that I could find, and I got bored of looking at SOLAS and STCW regulations so I didn't find the out clause in the IMO conventions."
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nm3uwr | How does so much plastic actually make its way all the way into our oceans? | Other | explainlikeimfive | {
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"Most plastic ends up in landfills or in incinirators. There are orders of magnitude difference. So if you were to throw away an entire bin of compacted plastic waste but accidentally a single plastic bag gets caught in the wind and some how ends up getting washed out into the ocean you will still contribute more to the plastic ocean waste then the average human. The problem is that there are lots of humans and we produce huge amounts of waste. And plastic does not disappear so the trash in the oceans just accumulate. It is also worth mentioning that a lot of the plastic waste in the oceans are from boats. A lot of fishing equipment is made of plastics and when a fishing net snaggs the fishermen often just cut it and leave it in the ocean. But there are also lots of plastic bags, food containers, plastic bottles, etc.",
"Without getting too complicated, so keeping it ELI5, a mixture of: * Littering * Open dumping (no 'lid') * Spillages * Fishing * Illegal dumping (sometimes 'legal' or rather not legislated against - some nations have little/no waste management infrastructure) Much of this is then gets into the ocean by various means, this can be via: * Rain * Streams or rivers * Drains * Wind * Storms Note some people dump straight into rivers and oceans. This can apply to macro- or micro-plastic, so the big and the small. Edit: Doing things like this does not help: [Plastic rubbish been dump in the amazon river]( URL_0 ) [excavator on a bridge collects garbage accumulated on the surface of a flooded river and throws them back into the water on the other side of the bridge]( URL_1 ) [Rubbish being dumped by riverside in Peru]( URL_3 ) [Waste dumped into river by town panchayat workers in Cuddalore district]( URL_2 )"
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nm3ysh | why do we stop smelling things over time? | Like when a person doesn;t smell their own BO. Or like when you walk in a room and you notice a smell but later on you don;t notice it anymore? How does this work? | Biology | explainlikeimfive | {
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"Your nervous system gets tired, so after a few minutes smell receptors stop sending signals. focus on new smells only basically.",
"What you're describing is called \"nose blindness\". A person is nose blind when a smell has become so normal to them, their brain tunes it out. We're programmed to be on the defensive subconsciously all the time so our brains are always looking for changes in our environment that could be potentially dangerous. In other words, your brain is constantly looking for the next \"lion\" while allowing you to focus on living a life not entirely full of fear and worry. This means that background stimuli that your brain has determined isn't harmful, and you aren't focusing on, get muted so it can be ready to identify the next change in your surroundings that could be potentially dangerous.",
"I think it's just our body adjusting to the enviroment. Think about it, how many times have you sprayed yourself with a perfume and stopped smelling it after 30-40 mins, it's because your body is used to it. Same as when you buy an airfreshner in your car but you cant really notice it after a few days.",
"Not everyone. Those with chemical intolerance cannot get used to certain smells. For me, it is artificial scents, cleaning solutions, coffee and cigarette smoke. Hence, strong smells often give me headaches and cause illbess"
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nm3zra | How do traffic experts determine the maximum allowed speed on some street? | I know that they have to take different factor in consideration, as well as the fact that the type of the street (e.g. is it a highway or a street inside the town) determines the speed. However, you will often see that inside towns some streets have 60 km/h limit, some have 70, some have 50. How is this decided? Is there some sort of a formula? Is it an expert guess? | Other | explainlikeimfive | {
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"Civil engineer here, there are lots of factors that play into speed limits. I do not know of a formula used to determine speed limits, because normally the roads are designed *around* the speed limits imposed by the government. One of the most important factors a government uses to determine speed limits is stopping distance. If an area contains crosswalks, it is important for the car to be able to stop in time. A car going 30mph takes nearly twice as much distance to stop as a car going 20mph, which is why most school zones are so slow."
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nm48yb | why do hdmi/usb cables top out at around 50 feet long, when buildings can literally have miles of ethernet cabling and function just fine? Aren't they all just ones and zeros? | Technology | explainlikeimfive | {
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"First, while there may many miles of ethernet cable in total, each length of cable between two connections is limited to several hundred meters at best. So there are not miles of a single cable even for ethernet. Second, 0 and 1 are symbolic representations. The actual way to encode the 0 and 1 are different for different protocols. So one might have \"0\" encoded as 0V and \"1\" as a 5V, others might use frequencies such as 99.9 MHz as \"0\" and 100.1 MHz as \"1\". These different systems have different performance characteristics by design. Third. Each system is designed for different uses. The higher performing uses are generally more costly in terms of the hardware needed and the amount of software needed (why ethernet has things like switches and routers costing tens to hundreds of thousands of dollars) USB is designed as a low cost, simple interface which is why it can be put on devices costing even less than $10.",
"Ethernet has a limit as well, approx 100m. It takes a lot of power to push a signal a long distance. So you need wires capable of supporting that much power... which means thicker cable, more shielding, etc... then you have to protect equipment that is getting full power just 3m away. So engineers come up with compromises. For ethernet around the whole building, there are switches, hubs or other devices in place to receive weakening signals and push out a quality signal for another 100m.",
"Voltage drop and loss is a thing and outside interference messing with the signals is a thing generally if your going to have long cables you'll have signal boosters and data compression along the length",
"Every wire - has a conductor inside it - mostly of copper. The copper used is of a high grade of purity - yet has some impurities in it. Hence even the good quality metal conductors / wires (like those used in hi-fi electronics / video cables) have some small amount of internal resistance to carrying the signal current across it. The \"ones and zeros\" are in the form of an electric voltage / current. When electricity encounters this resistance - it has to work to overcome it (and in the process generates a small amount of heat - which is why some wires heat up when high current is drawn through it). This work done by the electricity (signal) reduces its signal strength and over some distance this loss of strength is so much that the receiver gets either a partial / broken signal or of very low strength or intermittant signal or no signal at all. This leads to \"loss of functionality\" of the equipment / purpose for which the wire is being used. Hence the wire length is controlled based on the signal loss in the wire (and they use amplifiers / signal boosters when very long lengths of wiring is to be done). This problem is largely solved in \"fiber optic\" cables - where phenomenally long distances can be covered using FO cables without boosters. This is because of the very low resistance of the FO cables to transmitting light (where the \"ones and zero's\" are in the form of light pulses)"
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nm4vuh | Why do "red skies at morning" mean it's going to storm later that day? | The old saying goes, "Red sky at night, sailor's delight. Red sky at morning, sailors take warning." Red skies at dawn mean storms are coming. Is that even true? And if it is, how can red skies at morning bring storms, but red skies at night mean fine weather? | Earth Science | explainlikeimfive | {
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"It has to do with the scattering of incoming solar radiation. It is called Rayleigh scattering. the way weather systems travel is from west to east. The sun rises in the east and sets in the west. Incoming solar radiation deflected sideways at an angle. If that angle is high then it brings about blue skies and such. If there is a blue sunrise that, to me, as a weather forecaster tells me I have low pressure to my east. The storm has passed. As a result of low pressure being to my east, I will have high pressure to my west. High pressure is associated with good weather and great conditions. The high pressure is to come and move over my station. High pressure brings about a low sun angle because it condenses the atmosphere. This low sun angle gives us our red sunrises and sunsets. Edit: This is more of a mid latitude United States phenomenon. I decided to give it another shot— see below👇 Sun rises in the east and sets in the west. Cool. If at any point the sun rise or sun set is the color orange, red, or pink it can be inferred that the atmosphere is being condensed under the influence of high pressure. Because the sun is low in the sky and the atmosphere is condensed this is used to locate where high pressure is. Whether it is departing or arriving to you. On the other hand, low pressure within the atmosphere allows it to expand. Therefore, wherever low pressure is located the sky at sun rise and sun set will not appear the colors aforementioned but will be your usual blue sky. This is due to the lack of condensation in the atmosphere. It allows the blue to be seen instead of the other colors on the visible spectrum. In the mid latitudes (not the equator or the poles) between 60 degrees N and 30 degrees N there is the polar front jet (jet stream) that is high in the sky and it helps high pressure and low pressure move across mid latitudes in a west to east fashion as this is the only way the wind travels in the polar front jet. So this is the way low pressure systems (more commonly frontal boundaries) move with high pressure ahead and behind the fronts. Weather is fluid and ever changing. What one may understand may be understood differently by another.",
"Sounds like this was answered well already but just to add...I was a weather forecaster for the Air Force for 6 years. We actually had a few lessons about tips and tricks that were true to forecast. Red sky was one, also leaves that are showing their underside mean it will rain soon, cricket chirp intervals are indicative of specific temp ranges etc. There were more, I just can't remember as this was over 10 years ago. I was blown away by how many of these \"tips\" I had heard prior to my experience forecasting actually being true. Science is some cool shit!",
"The Atlantic Ocean has the trade winds that blow from the east to the west. If clouds are coming (rain or a storm) the sky is red during the sunrise. Likewise, a red sunset means the storm is already past you. So technically only accurate in the Atlantic or the the eastern Pacific.",
"\"red skies\" means the morning or evening sun is lighting up clouds, and it's important where those clouds are in relationship to you, keeping in mind that weather patterns typically move from west (sunset) to east (sunrise). Very broadly speaking, bad weather (as in a frontal system) starts with high clouds and gets progressively lower as it gets closer. If the sun is rising to your east and lighting up high clouds above you, a front is coming. If you can see red light at all it means that the sky is pretty clear between you and the horizon. So if it's morning and red sky you know that the clear weather has already passed to your east, but the high clouds are an early sign of approaching bad weather from the west. Meanwhile if it's evening with a red sky you know the weather is clear all the way to the west, and that clear will be tomorrow's weather for you",
"When the sun is near the horizon, it tends to get redder. The trick with the phrase is to look to the opposite horizon. Just before the sun rises in the east, the reddish dawn light will illuminate high clouds to the *west*, indicative of a storm system which are traveling toward you (most weather travels west-to-east). The other half, \"red at night, [sailor's/shepherd's/camper's] delight\" has to do with the setting sun illuminating high clouds to the east which have passed, indicating that the stormy weather has concluded.",
"According to LOTR red skies mean blood has been spilled this night, they said nothing about storms.",
"So first off you need to know about light and its different wavelengths, im fairly sure red light has a longer wavelength while blue light is much shorter. When light shines through the atmosphere red light having a long wave can easily get past and around small particles without being deflected or blocked unlike blue light which gets filtered out by those fine particles. The sun rises in the east and sets in the west which also drives the wind and weather systems as the sun heats the air and water. So when the sun rises or sets most of the light is traveling all the way through the atmosphere, like instead of going top down the light is going side to side so it passes through much more of the atmosphere and any suspended particles will filter out blue light while allowing red light to pass right through and this mostly happens at sunrise or sunset when the light is going east/west instead of top down like at noon. So thats the bit about the red skies (how/why the sky turns red) the red color is important because it means the air has lots of particulate which water vapor needs in order to condense. So if you see a red sky then whatever air that light is passing through will drop its moisture as soon as the relative humidity reaches 100% So the next bit is about the timing, red sky at morning sailor take warning, this means if you see a red sky in the morning then not only is there going to be a storm but its going to be coming your way. You can tell because the sun rises in the east and creates a heat/pressure front that pushes most weather systems to the west, so if you see a red sky at morning then your seeing the sunlight passing through the air to your east and you know there will be a storm to your east which will be pushed west so you will have to deal with it. If you see a red sky at night sailor delight means that you see a potential storm (red sky) but since its night/sunset your seeing the light pass through the atmosphere to your west and the storm should continue further west. Tl;dr: So the red sky means a potential storm. At morning or night tells you if the potential storm is to the east or west and that tells you if the storm is behind you or in front of you. This isnt a perfect methodology for predicting storms/weather and its a bit outdated but its still pretty cool."
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nm5eyg | Why do we use the term "Matrix" to describe materials? | I'm reviewing my materials science notes and I've no idea why matrices are all over the thing and I keep thinking of its mathematics meaning. What's the correlation between the two meanings? | Chemistry | explainlikeimfive | {
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"A material that is a matrix is a material that has something else embedded in it, and the idea is that idealized it is like a little grid with things in it, like a mathematical matrix. So like, if you had a bunch of limestone, that would just be limestone, but if the limestone had a bunch of diamonds in it (for some reason), that would be a limestone matrix around diamonds, and you could imagine it like the limestone is the grid lines, and the diamonds are like the numbers."
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nm6ogn | How can lab scientists know someone's sex and age from a blood test or dna sample? | Biology | explainlikeimfive | {
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"Biological sex is easy. They either have XX or XY chromosomes almost all the time. Age is harder, and there are a couple of different ways to do it. You can look at the chromosomes and check a part on the end of each called the telomere. Those get smaller and worn down as someone gets older and have gone through more and more cell divisions. But telomeres are very small and it is rather hard to see them with anything but the most advanced lab equipment. So more commonly there people will make an estimation of someone's age based on their blood chemistry. Because your blood chemistry changes dramatically as you age.",
"Sex can be determined by looking at their sex chromosomes. XX would be female; XY would be male. Approximate age is typically determined by looking at telomere length. Telomeres are like endcaps for your chromosomes; protecting your DNA from damage. Each time your cells duplicate, though, the telomeres get shorter. Shorter telomeres means a higher likelihood for DNA damage, which is what causes aging. This is only approximate though. You can't determine someone's exact age purely by that method, because telomeres from person to person can vary in length, and not everyone ages at the same exact rate."
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nm6rf1 | If photons have no mass, why are they affected by gravity? | Physics | explainlikeimfive | {
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"Because in addition to pulling things down, gravity also literally warps the fabric of reality. Light continues to travel in a straight line, but what defines a straight line gets changed. But it takes a ridiculously large amount of gravity to have a noticeable effect there. The Earth does not bend light to any degree worth mentioning it all, and our sun barely does it. In order to get a really noticeable amount of bending of light, you have to have something supermassive like a black hole thousands of times the mass of our sun.",
"Hi! In the theory of General Relativity (GR), gravity is not a force at all, but a curvature of spacetime. To understand how a curvature of spacetime can lead to the effects we observe around us, we have to understand how curved surfaces change the behaviour of straight lines. First things first: an object that has no force acting on it is force-free. Force-free objects do not accelerate and, therefore, move along straight lines. In a flat geometry, two straight lines which are parallel at one point will remain parallel for all times. That is, two parallel straight lines will never cross on a flat surface. So far so intuitive, right? But what happens, if those straight lines do not move across a flat surface, but instead along a curved surface? We call such straight lines on curved surfaces [geodesics]( URL_1 ). Imagine a [sphere]( URL_2 ) with two lines perpendicular to the equator. As they are both perpendicular to the same line, they are parallel at that altitude. Imagine two objects that are moving along the lines perpendicular to the equator. They start out parallel, and move in a straight line upwards. Despite the fact that neither of them is turning, the two objects that started out moving along parallel lines will meet at the north pole. Hence, despite the fact that both objects are force-free at all times, they experience relative acceleration. Such trajectories, that lead across curved surfaces without turning are called geodesics and they can be thought of as straight lines on curved surfaces. Objects under the influence of gravity follow [geodesics]( URL_1 ). As gravity curves spacetime, geodesics can experience relative acceleration despite the fact, that both objects following said geodesics are force-free. And this relative acceleration of force-free bodies is what Newton mistook for the gravitational force. According to GR, though, there is no force, only curvature which causes force-free objects to move along paths that seem accelerated to outside observers. This is why gravity is a fictitious force: The reason why two objects in a gravitational field may experience relative acceleration is not a force between them, but geodesic deviation between two force-free objects. **That is why photons are affected by gravity: photons follow geodesics through spacetime, and the presence of mass-energy curves spacetime. Therefore, the straight lines that photons follow through this curved spacetime appears curved to outside observers.** If you have any more specific questions, feel free to ask. ----- For a great video on the basics of GR, check out [this]( URL_0 ) video by PBS Spacetime."
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nm71ay | Mosquitos always amazed me. As much as we all despise them. So I'm curious? How do they survive on blood. Is it just a meal. Or do they contain nothing to create there own blood? | Biology | explainlikeimfive | {
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"Actually it's only the females that bite and take our blood, and they use it to provide nutrients for their eggs (some pretty alien-esque shit IMO), not to eat/feed themselves Mosquitoes actually subsist primarily on plant nectar, and thus play a small role in pollination",
"The blood serves a major purpose in that it provides the nutrients necessary to produce eggs. ONLY female mosquitoes bite mammals/reptiles.",
"They don’t really survive on blood. A lot of species of mosquitoes don’t drink blood at all, and in the species that do it’s only the females. They mostly survive off pollen and plants and stuff other insects eat. But for reproduction the females need the protein in blood to lay eggs."
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nm7g36 | how can NASA connect to distant planet rovers and far off satellites but there are still dead zones to cell phone coverage and internet connectivity on Earth | Technology | explainlikeimfive | {
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"NASA's satellites have a clear line of sight between whatever's on Mars or in space. On earth there's a ton of radiation interference and construction materials that block radio signals... cell signals are also based on towers on the ground. If you live 500 miles out in the woods and you're the only person there and there's no tower you're not going to get a signal.",
"The simplest reason is because NASA is using large, powerful radios and radio telescopes to do the communication. While cell phone communication is done with much smaller and comparatively weaker radios.",
"Because the communications are designed that way. Wireless communications involve tradeoffs of power, speed and latency. If you're willing to compromise on one aspect, you can gain in another. You choose encoding and power based on what you want to accomplish. Dead zones exist for cellphone coverage because it's not considered economically viable to close them. In rural areas, this is due to not wanting to build towers to service very few customers. In urban areas, it's mostly due to interference and obstructions. Again, these could be solved, but it's not worth the effort to do so - putting an antenna in a tunnel just so people momentarily passing through it can keep their connection isn't worth the bother. On the other hand, when NASA designs a rover for operation on Mars, it chooses power levels and encoding designed to operate at that distance because it would pointless to send a rover if you can't communicate with it."
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nm7mk0 | ORS vs Water for Dehydration | Why is it dangerous to treat dehydration with water? Why are Oral Rehydration Solution ("ORS") recommended for treating dehydration instead of water? | Biology | explainlikeimfive | {
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"When you are dehydrated, you're usually not just missing water - you're also missing a lot of other stuff (notably salt) which is needed for your body's water supply to function properly. If you drink pure water when dehydrated, you can end up with too little salt in your system, which can in turn cause your cells to absorb water and swell or even burst. ORSs typically contain the right amount of salt to restore the proper balance in your system, as well as an amount of sugar that encourages your body to take it up.",
"ORS contains electrolytes - basically salts or things that chemically behave like salt. Water likes to \"stick\" to salt. If you've ever put salt on a piece of meat (or e.g. the cut surface of a vegetable) and let it sit for a while, you'll have noticed little droplets of liquid appearing on the surface. The salt \"pulls\" the water out. This same mechanism is also used by your body to absorb water from the gut. There are no \"water pumps\" in your gut, but there are \"salt pumps\", which can move salt molecules from inside the \"tube\" of your gut (where the food slurry sits), to the other side where it gets into the bloodstream. Because water likes to go where the salt molecules go, moving salt into the bloodstream causes water to move with it. If you're (truly) dehydrated, you're usually also low on salts, since you sweat and pee them out too (or lose them through diarrhea or vomiting, which are both common causes of dehydration). Without (enough) salt, you cannot absorb water (or not very well). So in cases of actual dehydration (not just being a bit thirsty or not drinking quite enough on a regular day), ORS can hydrate a person more effectively than plain water, and in some cases plain water may not be absorbed well enough to even treat the dehydration adequately. ORS's of course are formulated to contain a good balance of salts. If you ingest too much salt, this can actually cause dehydration because the salt in the bloodstream pulls water out of the cells (which then gets peed out). Sea water for instance will dehydrate you and is dangerous to drink. ORS is convenient because it immediately gets a dehydrated person what they need, which is important especially when the dehydration is severe. For very severe dehydration, though, ORS will still be too slow since you have to wait for it to pass through the digestive system. So in really acute cases of dehydration, doctors will inject a saline solution (again, water + the right amount of salts) directly into your bloodstream. For mild dehydration (and when the cause of dehydration isn't ongoing, as it is with vomiting or diarrhea) it is sufficient to just drink fresh water, and replenish any losses of salt simply by eating something."
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nm7p5x | What do comas feel like and how do they work? | Other | explainlikeimfive | {
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"I have a friend who spent some time in a coma (2 weeks, medically induced to help combat a massive lung infection caused by inhaling vomit as a result of drinking far, far too much. Almost killed him.), he said he was essentially dreaming the whole time, far as he was concerned he'd been skiing in the mountains and had bungee jumped from a helicopter whilst naked in bed amongst other things all punctuated with drinking and partying. He'd had a wild time! One odd thing was for a while after he woke up he kept pointing things out that weren't here, like his dreams were bleeding through to reality for him, he insisted there was a plane flying overhead (a jet fighter I think) at one point and got annoyed that nobody else could see it haha."
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nm7x0a | Why do photos from space show sunsets across a region that would make sense from the ground-eye perspective? | I always understood the red of a sunset as being due to the path the sunlight has to take across the atmosphere. This path is longer and denser when the sun has dipped further behind the horizon. Am I the Idiot of does this not make sense from space? Surely, from space, the light of the sun comes from a direction that does not equate to the photos I have seen. I can accept that we see a sunset of sort from space, but the photos I have seen make it look like there is a rolling band of glowing red in the clouds below. & #x200B; Are they just edited, so that people like them? Are space sunsets still a thing, except they are nothing like the photos? (I'll add one below) | Earth Science | explainlikeimfive | {
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"You see from the space the same clouds you can see from the ground. They are painted red because the light is filtered by atmosphere and the sun position for this point is low. Clouds reflect this red light in all directions and you see it from space."
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nm8243 | How does a bakery business not fail? | Yesterday I was picking up some pastry and realized just how much stock bakeries have on hand at any given time. The bakery I went to had 10 refrigerators filled with different pastry’s and another 20 feet of display cases with various cookies and other baked items. I’m sure they do a good business but there’s no way they sell all of this stuff. ELI5 the economics of a bakery. Thanks. | Economics | explainlikeimfive | {
"a_id": [
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"Bakeries that are successful often do sell through nearly all the stock they produce. If you visit a successful bakery towards the end of their hours you'll often see your options are quite limited.",
"Well it’s like anything else really, supply and demand. It just so happens that a lot of people want to buy fresh baked goods, and the stores have the stock to do so. Plus, they set prices at a certain point that they can cover basic employee wages and potentially make profit - not too low that it discourages healthy competition, and not so high that people won’t come and buy the products as other locations offer similar goods for cheaper. It’s like any other business, really. Bakeries also wouldn’t produce so much food that they’d end up throwing out a good portion of their stock, and they’ve learned this through years of experience.",
"the successful bakeries often can push their whole stock for the day and that's all they tend to make for that Day. if you ever been to one of these near closing hours you'll see a lot of empty shelves and limited options if you intended to buy anything. these bakery also tend to do custom work on request for events so that's another avenue for profit. lastly in the odd event they end up with a stock surplus these bakery generally try to have deals with charities to offload their remaining daily stock with them at a very discounted price(exception being the products that can actually stay in good condition thru a couple of days)."
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nm85uz | Why are birds scared of scare crows in a field? | Never really questioned it, any farmers or enthusiasts willing to explain it in way that isn’t to condescending. I don’t really know how to explain it to my daughter other than it looks scary😅. I am open to all answers from cultural, science, common sense to aesthetics. | Other | explainlikeimfive | {
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"According to the internet: “The traditional scarecrow is a decoy made in the shape of a human. It is dressed in old clothes and placed in an open field to discourage crows, blackbirds and starlings from feeding on seeds and sprouting crops. The loose clothing flaps in the breeze, giving the illusion of a real, moving person.”",
"In reality, scarecrows are pretty ineffective... The theory is that a human shaped dummy will trick the birds into thinking there is an actual human standing in the field, which they will naturally stay away from. In reality this may work for a short while, either because of the human shape, or just because the materials it is made from will be flapping about in the wind, but after a short while the birds will become accustomed to it and return as if it wasn't there. This is why you generally won't see many scarecrows outside of children's books. With modern commercial grade farming they don't provide enough of a benefit to be worth the bother, so will only really be used by smaller show farms and similar who will have them for tradition or aesthetic reasons."
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nm8byp | How does inflation work? | So I think we're all familiar with the way the money works. The more of it there is, the less valuable it is. But why exactly does that happen. More accurately how did it happen in the past? I would understand for an algorithm to count the money virtually, but how did inflation happen before internet banking? For example in Germany after WW1, an apple costed like a bazilliun dollars. What causes it exactly and how do they know if they have more money in the system? | Economics | explainlikeimfive | {
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"From what I understand, everything in existence has a value but there is a finite amount of money to pay for it all, when the value of goods and the amount of money don't match up, that's when you get inflation. E.g. you have 100 loaves of bread and £100 in your world then each loaf will cost £1. If you print an extra £100 and you still have 100 loaves of bread the basically each loaf of bread costs £2. Yes it's good to have more money in your pocket but what can you do with it if there's nothing to buy with it? I am not an economist btw!",
"Ultra short answer If everybody has too much money and there is not enough stuff... stuff prices go up (Inflation) If nobody has any money and there is too much stuff.. stuff prices go down (depression)"
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nm8i03 | How do they track down and find a patient zero? | Biology | explainlikeimfive | {
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"It is basically just a bunch of detective work. You look at where several different outbreaks are, and then you try to find the common link. For instance, if in one town there is an outbreak that seems to be based around an office, and another outbreak that seems to be based around a church, it is reasonable to look for anyone who goes to both that office and that church and test to see if they have had the disease. If so, they are likely the common link between the two. And if they aren't patient zero, you can go back from that person to try to figure out who patient zero is. You might have to go back several times, but eventually you can track them down if the spread has not gotten too advanced. Once a disease is said to be in the general community spread stage, you can't really do this anymore because there are just too many different people that someone could have gotten each infection from. And obviously how a disease spreads plays a big role too. It is much easier to track down patient zero for something like an STD than it is for a respiratory disease, because it is much easier to catch a respiratory disease in passing from someone else.",
"I'm currently working as a contact tracer, so this is my job. Someone goes into the health department and gets a test for, say, gonorrhea. The test comes back positive, so the result gets reported to me. I (or someone like me, I'm tracing for COVID-19, which doesn't have easily identifiable patient zeros for various reasons) call them, possibly going so far as to visit them at their home if they don't answer, and ask them to tell me everyone they've had contact with. For COVID that's a pretty vague question (which is part of the reason this has been such a nightmare), but for STDs it's pretty straightforward: if you had sexual contact with someone, they are a contact. I do this in a private location so they don't have to worry about someone else learning their secrets. I take that list of contacts and hand them off to another team, who tracks down and calls all of them to ask that they get tested. If any of them did get tested, or started having symptoms, prior to the first guy, they get added to the network of contacts we are building as a source for their infection. Repeat this process until all your remaining infections point to exactly one person, and now you have patient zero. For many outbreaks and diseases there is no patient zero who can reasonably be identified. For COVID, you can get it from a random stranger at the store up to two days before they even start showing symptoms, and up to ten days after. You're more likely to get it from people you spend more time with, but there's no guarantee. For other diseases, like foodborne illnesses, everyone gets it from the same source, but that source isn't a person. Diseases like tuberculosis have incubation periods up to several decades long. For diseases with multiple causes, like some cancers, there's no way to tell at all."
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nm9av2 | What do consulting agencies do? I see all of my friends from college getting jobs at Accenture and Deloitte. | I jumped straight into the start up world right out of college, so I don’t have corporate experience. I’ve always wondered what these consulting firms actually do and the realized value of using them. | Other | explainlikeimfive | {
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"They mostly provide specific and time-limited project execution. A company will do this when they don't have the people to do it themselves, don't want to hire them \"forever\", and/or need expertise they don't have. A classic example is large-scale IT implementations. If you're switching your entire enterprise software stack from, say, Oracle to SAP, that's a \\*huge\\* undertaking. You don't just have hundreds of IT experts in both systems lying around. You could hire a bunch of contract IT folks but you also need project management, contracting, transition, training, etc. You \\*could\\* create that org by hiring all the right skills (and hoping you got it right because you probably only do this every 10 years or so), and they laying them all off when the project is done. Or, much more simply, you go to a Deloitte or Accenture who does this kind of thing constantly and say, \"I want to hire your SAP implementation team.\" Anything big/important enough to require large-scale project management but rare enough for any one company to need to do it very often is ripe for consultants...hire experts to do it, then go away: big IT implementations, restructuring, mergers & acquisitions, divestitures. It's the same reason most people hire general contractors to build a house and don't do it themselves. They're also good for things that require a cross-industry perspective. Suppose I'm thinking about entering a new market that's adjacent to my current business. It looks good to me but I don't know that market as well as I know my own (because I'm not in it yet). I can hire a consulting company that works in that industry to assess it for me...they know all the players, do their own research, etc. and should have better insight than I do. I can at least compare what they think to what I think. They can be far more general if you want (consultants will take on anything for a price)...\"I have $1 billion extra cash this year and I need to do something with it...what should I do?\" Like any contractor, your mileage may vary. Wildly.",
"As a consultant, you usually know something really well. In my case, computer security. Now, a company may have need for that particular piece of knowledge, but not full time. They need it now and then, but it's not like they could hire a security specialist because there wouldn't be anything else for them to do at the company, and most people who are specialists can't do much else really well. So when they encounter a specific problem that needs an expert in a particular field, they hire a consultant. For a week, maybe for a month. Usually for a very limited amount of time, to take care of the problem, or tell them what they should do to avoid it in the future. Think of it as hiring a mechanic when your car breaks down or a plumber when your pipes are leaking. They come, fix the problem, tell you how you can avoid having the same problem again, then send a huge bill. Another reason why you could hire a consultant is that you want to build something new but don't know how to build it. You may know how to run it, but not how to build it. The consultant comes, he usually has the relevant contacts with other specialists that can aid in the construction, they tell you what to watch out for and what options you have. Like when you want to add a room to your house but don't know how, so you hire someone to do it, and they also can give you tips and ideas how to do it efficiently and maybe where you can save money, they know what legal stuff you have to take care about if you need permits or something, because they do that all the time so they know things you might forget about that will later come to bite you in the back.",
"Depends on the agency. Large ones like KPMG, Deloitte etc offer a wide variety of services, anything from: - corporate restructuring - IPOs and other shareholder structuring, advice and management - basic accounting - auditing (if you suspect someone stole some $$ or did something naughty they'll come in and find it) - pretty much any aspect of running a corporation that you need help in. Ill give you an example - the couple who owns a family run hotel want to retire to a beach somewhere and sell the biz to their kids who are already involved in the operation of the hotel. One of the kids will run the hotel day to day, the others just want to invest. Seems like a simple transaction right? Even if everyone gets along and the parents are willing to sell \"at cost\" to the children, its not as simple as it seems. There are huge tax implication for the parents depending on how the sale is structured and how and when they receive their money. There are huge liabilities and implications for the children: what if a couple splits? What if they disagree on what should be done? Who gets what money if someone offers to buy everyone out? Who gets sued if a guest falls off a balcony? These things are what ruin families in family run businesses of they're not thought out in advance. Now, between various lawyers and accountants you'd eventually muddle your way to some reasonable compromise. But a consultant would come in and say: ok, to minimize tax burden on the parents, minimize purchase costs for the children and protect the assets of the hotel as an investment from the operations of the hotel as a business what we're going to do is form two companies. Hotel Assets Inc will own the hotel, and ownership shares split evenly amongst the children. lets set out rules for if couples split or want to bail from the investment. Hotel Oper Inc will rent/lease the hotel from Hotel Assets Inc for < price > , and we'll lay out amounts etc. ahead of time and rules for enforcement that cover situations like if covid hits and Oper Inc can't make payments to Assets Inc. etc. We'll set out a purchase/repayment plan that covers payment schedule to the parents so they get their money and don't get a nasty tax bill. As a consultant, I won't be an expert on taxes, but Ill know they have to be considered and Ill know the right questions to ask. I won't be a real estate lawyer but Ill know there are title searches that are required for the transfer and Ill know the right questions to ask. Ideally, my own company will have these experts to ask, so I can come with a complete solution and have \"all the answers\"."
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nm9gdo | Why can our bodies digest cooking oil but not something like crude oil? | Vegetable oils and different petreleoum refined oils are very chemically similar so why do our bodies react so differently to these chemical compounds? | Biology | explainlikeimfive | {
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"> Vegetable oils and different petroleum refined oils are very chemically similar Nope. Vegetable oils have carboxylic acid groups on one end which significantly increase the reactions that enzymes can perform. Plants are significantly chemically different from minerals.",
"Cooking oils are lipids, a molecule with a saturated or unsaturated carbon chain tail that terminates in a carboxylic acid group. That polarized and reactive acid group at the end gives your body a place to react and manipulate the molecule. Crude oil molecules typically don’t have that, they’re pure alkanes with no obvious “weak spots” for enzymes to work with. Crude also contains a lot of sulfur molecules and a slurry of toxic aldehydes and ethers."
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nm9tj8 | What exactly is a computer doing when it "installs" something? | Like is it just creating the right files and folders in the right place or is it actually creating a special link or internalized set of protocols within the system? | Technology | explainlikeimfive | {
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"Both. The files & folders all need to be copied to wherever they're supposed to be. But the operating system (usually) needs to know the program exists so that it can send it the right type of files. For example, when you double-click an image file, the operating system looks up \"Who opens .jpg files? Oh...it's this Photos app.\" In order for that to work, the Photos app had to tell the OS that it exists, what kinds of files it can handle, and how to \"talk\" to it. For most large software, the software is also using a lot of shared resources (both hardware and software) on the computer. Part of the installation process is the program figuring out what and where those shared resources are, installing any that are missing, and generally figuring out \"where stuff is\". It's like unpacking after you move in.",
"both most installers will do a few steps. - generate a directory if one doesn't exist - check for any file dependencies and fix as required - setup the shortcuts and file associations(so the system knows that x program handles the files made by itself.) - cleanup after itself and setup a uninstaller script for later use."
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nmaajl | Why does cereal come in both a bag and a box and not just a bag? | Other | explainlikeimfive | {
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"Some cereal does come in just bags. Most are in boxes though because it adds a harder protection to keep it from becoming a crushed mess",
"Moisture, cardboard lets water in and could damage the cereal in the box, by placing it inside a plastic bag is to prevent water damage. Cardboard could be done without but it may lead the contents being crushed in transit or storage, so if the contents is fragile the cardboard may protected it."
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nmao7m | Why does audio clipping stay even with reduced master volume? | Other | explainlikeimfive | {
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"Think of it like drawing on a sheet of paper. If you accidentally draw off the edge of the paper, adding another sheet of paper doesn't bring back anything you drew past the edge. That's what happens with audio clipping. Audio is just data being recorded, but if it's too loud (going \"off the chart\") you lose that data. Reducing the master volume (adding more chart, in a way) can't bring back the data you lost."
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nmatb8 | Why sleeping just 30 minutes less during night, horribly affects my cognitive function and performance? | I need at least 8 hours of sleep, if I sleep only 7h 30min, everything changes, my mood changes, my thinking speed decreases drastically, I'm much less productive. How can as little as 30 minutes of lack of sleep affect the whole day in such a brutal way? | Biology | explainlikeimfive | {
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"Probably because you're interrupting a sleep cycle. During an average night, you will go through two sleep cycles. Your brain will go into REM sleep, then fall into deeper sleep, bounce around for about 90 minutes at the lowest levels of sleep, then come back up for REM sleep and do it all over again. A whole sleep cycle takes about 3-4 hours depending on the person. If you wake during REM sleep, you will probably feel refreshed. Wake during one of the deep sleep phases, though, and you're pretty fucked up. It's a terrible analogy, but it's sorta like you tried to go into fourth gear from a standing stop if you wake from deep sleep, rather than going smoothly from third to fourth when waking from REM. So it has less to do with the total amount of sleep you got than with the length of your sleep cycles and when in one you are woken up."
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nmb6eb | Why do we get sleepy when we eat food | Biology | explainlikeimfive | {
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"Your digestive system is super expensive to run, not just in energy, but in oxygen requirements. As a result, after eating a large meal your body will direct large amounts of blood to your intestines to both fuel that process and carry away all the nutrients. This reduces the amount of blood available for everything else, which makes you sleepy. Incidentally, this also means the digestive system basically shuts off in times of bodily stress or exertion. Exercising right after eating is a bad plan because you will either shut down digestion right when it's most important or have insufficient oxygen supplied to your muscles, causing cramps. Surgery also does this, as the body is directing that blood supply to healing instead of digestion. After large abdominal surgeries it can take months before you have your first bowel movement, just because your digestive system took that long to turn on again.",
"TL;DR It's not \"food\" but \"carbs\" - when your body is in \"fat burning mode\" you can eat as much non-carbs as you like, without this \"sugar crash\" aka \"tiredness.\" Imagine there was something so rare that your body tried to save as much of it as possible if it ever found it. There is, it's called glucose aka sugar aka carbohydrates. Due to our success as humans at making things we like, we now have way too much sugar, so much so that we add sugar to absolutely everything - including even ketchup and salad dressing. When your body sees all this excess sugar, it absorbs as much of it as possible - so much so that your body has almost nothing left to run on afterwards... \"a sugar crash\". The trick is to never consume that much sugar. If you eat non-carbs, you can eat as much as you like and you won't get tired (after a 2 or 3 transition period to make the switch from running predominantly on carbs to burning fat instead.) It's like your body can run two fuels: petrol/gasoline aka sugar or diesel/kerosene aka fat. (Emphasis on \"like\" - these actual fuels will kill you :-D) But your body is not very good at running on a mix... and it takes 2-3 days to start up its diesel engine. And the petrol engine kicks in real quick when there's petrol available. Cutting sugar has become exceedingly difficult. Sugar tastes good so it's added to almost everything in order to make you more likely to buy it. If you look on the back of anything you buy, you will see the bulk the sugar listed as Carbohydrates, Glucose, Sucrose, Sugar. You are not supposed to have more than 5g at a time (1 teaspoon) or maybe a maximum of 3 teaspoons a day. Our bodies need a bit, but not a lot - but when you eat anything bought at a shop, you effectively get an overdose of sugar - easily 4 or 5 teaspoons or more in a take-away or fast food meal - double that if you consume sugary soda with it. When your body sees all this excess sugar, it releases insulin, which quickly removes most of the sugar (and starts the process of storing it for later in the form of fat ie. eating fat doesn't make you fat - your body readily uses it and discards what it can't store - sugar makes you fat - your body is really good at converting it into fat for storage - leaving you tired. Fun fact: the less sugar you eat, the sweeter everything becomes - it takes a few days. The Keto (Fasting) or Low Carb diet is all about eating no sugar, or very very little - and most people who follow it do it because when they do they do not get \"hangry\" or this \"sugar crash\" after meals or drowsiness in the afternoons. It is so hard to cut sugar from your diet, that it took me 40 years to figure out that if I cut sugar completely, all my allergies disappear. My peeve with the food industry is that I can't fathom how they can't understand that people who don't eat sugar DO NOT WANT \"sugar replacements\" - everything is naturally sweet if you don't eat sugar. Adding xylitol, stevia or erythritol not only tastes disgusting, it completely dominates the natural taste of things. Sure, occasionally it's \"nice\" to have a little bit in something that might otherwise be a bit bitter... but really!? Humans have been \"hunter-gatherers\" for many many millennia, before we learned how to farm... during those times it was normal to only have a few meals a month. Our bodies are well adapted to fasting aka burning fat - which is why a large portion of the world has incorporated it into their religion. If humans have only been around for a day, we've only been farming for a minute... and eating what we eat nowadays for less than a second. Think about that the next time you wonder what you're consuming actually tastes like... once your taste buds have been freed from the yoke of sugar.",
"Your digestive track, what breaks down the food, needs energy to function, and heavier meals need more energy to break down. Essentially, it’s like using a lighter to light a campfire; to extract the energy from the fuel, you need a small input at the beginning. Your body gets that energy by pulling resources from elsewhere in your body, hence why you feel sleepy."
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nmbogh | Why some plants like roses love severe pruning? What does pruning do to get them into vigorous growth the next season? | Biology | explainlikeimfive | {
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"Roses don’t actually want to grow roses. They are a fruiting plant. They want to grow rose hips. If you deadhead a rose (cut back the plant once the flower has faded but before the rose hip has formed) then the plant must try again. Instead of putting all of its energy into growing a couple of rose hips, it puts its energy into blooming once more. The same basic idea occurs on a larger scale when you cut back the whole plant. You remove the larger branches and the plant doesn’t have to expend energy to maintain them through the winter. So it can grow *new* branches with all its energy in the spring.",
"Think of each stem and each bloom as taking up some amount of finite energy that the plant has to use in growth and keeping itself alive. Imagine the plant has 10 energy points, and each branch costs 1 point. 10 branches has you maxed out on energy, so it’s just barely got enough to keep up with maintaining these existing blooms. It doesn’t have enough energy to create new blooms, or even to make the existing blooms flourish extra. Throw in some dead or diseased parts, and that takes away even more energy. Fewer old blooms and branches and things that suck up energy = more energy for the plant to use to both stay alive and also have even more outstanding growth. Basically, pruning back the old dead and dying pieces allows the plant to redirect that energy into generating new blooms."
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nmcunq | When you convert an MP4 to a GIF, why does the file size often become larger? | When you convert a video with sound to basically a slideshow of pictures and effectively remove that sound from it, how would the file size actually increase? Shouldn't it decrease due to the smaller amount of data it now carries? | Technology | explainlikeimfive | {
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"Gif uses an extremely old and inefficient form of compression, not really made to deal with anything like a movie. Gif is best suited to low color moving artwork. It was never intended to be used for video, and any video usage is just showing that you can brute force things if you really insist and don't mind throwing obscene amounts of bandwidth at the problem.",
"No, a gif has MORE data because every frame is reproduced at full pixel resolution. Video compression saves bytes under the assumption that not every pixel changes frame to frame, so there could be a bunch of frames where only the pixels that DID change (or change beyond a specified threshold) are encoded - if a pixel isn't mentioned the player just leaves the pixel value from the previous frame as it is. Now every bunch of frames there'll be a \"key\" frame which IS a complete full resolution frame of every pixel which kinda resets things to normal. But a gif is a full resolution picture each and every frame."
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nmdfvb | Why do we biologically get “burnt out” from doing work like studying? Why can’t we just work for hours? | Biology | explainlikeimfive | {
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"It is physically taxing. Even if you rest your brain takes about a third of the resources you need. studying actually is pretty hard work",
"The same reason you can't just run forever or swim forever. Your body only has a certain capacity of fuel for the processes. Like running, you can improve your \"fitness\", and develop the capacity to concentrate for longer periods of time. Allegedly, college helps give you opportunities for training."
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nmehuf | What Exactly Does The Phrase "You Want To Have Your Cake And Eat It Too" mean? | Other | explainlikeimfive | {
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"It means you have unrealistic expectations - you want outcome A and outcome B from a situation even though it is physically impossible. You either have the cake, or you eat the cake, but you can't do both - as soon as you eat the cake you no longer have it.",
"The expression makes more sense when reversed, as it used to be said. \"You want to eat your cake and have it too.\" As in, you want the benefits of having eaten the cake, but you also still want to have the cake on display so others can see it. But you can't eat it and also still have it around on display.",
"It means you have two mutually exclusive options: you can either eat the cake now, or have it later. When people refuse to commit to either, they’re metaphorically attempting to both eat and save the cake - a futile exercise that will likely result in a half-assed outcome.",
"Yesterday my three year old *sobbed* after his cupcake was gone. He wanted his cake, but he'd eaten it. He enjoyed eating his cupcake, he wouldn't have *not* eaten his cupcake, but he didn't understand why it disappeared. He wanted to have his cupcake, and also eat it. Poor kid wanted to have it both ways.",
"i thought it meant you can physically have a cake , but if you eat it you will no longer have it. it is impossible to have a cake if you’ve eaten it"
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nmejva | Why are we able to eat dessert after a large meal despite being full and unable to eat more food? | Biology | explainlikeimfive | {
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"Because you're not full. If you were literally full you wouldn't be able to eat more food. Then normal feeling of \"full\" is your body saying, \"I've got enough calories in here, you can stop now.\" There's plenty of physical space at that point. And dessert tastes \\*really\\* good, so we'll eat it even if we're \"full\". It's a new flavour/texture profile that appeals to us in a different way than more of the same food we just finished eating.",
"“Ice cream is for filling in the cracks.” I just heard that quote like last night. Can’t recall where though."
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nmf38a | why are some 100% cotton clothing soft and breathing and others tough and seemingingly not 100% cotton? | Sorry if this is a dumb question but it has become quite frustrating in quarantine when ordering online and some 100% cotton products are what you expect whereas others are quite tough and seem like they've been made with a tougher material. Just wondering if it's due to the quality of the cotton or quality of how it's made or we're being swindled and it's only partially cotton. Cheers | Other | explainlikeimfive | {
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"It depends on how much work has been done to the thread, what the thread count is, the diameter of the thread, and if any softening processes have been done to it afterwards. Like tumbling it in a drum of ceramic stones."
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nmf3pz | How is music a thing? | Biology | explainlikeimfive | {
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"Repetition and pattern recognition. It's like any other language, if you hear a minor chord associated with sad things over and over you will make that association yourself."
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nmfdih | How do half lives work?? | So like I understand a half-life in like a mathematical theoretical sense, my question is how does this translate to nuclear elements? Let's say you have element X with a half-life of 1 minute. You have a 1kg sample and a 1g sample. In one minute, half a kg will have decayed from the first sample, but only half a gram from the second sample. There will be atoms in the first sample that will have survived for much longer than any atoms in the second sample. What is it that causes the variation on how long it takes before any one atom decays?? | Physics | explainlikeimfive | {
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"Think of it like this: each atom has a certain probability of decaying. In one half-life (one minute in your example), each and every atom has a 50% chance of decaying. Now think of the atoms as dice. Each minute you throw the dice, and those that roll three or less you remove - they \"decay\". That means each dice has a 50% chance of being removed each minute. Thus, your dice have a half-life of one minute. Each minute, half the dice will be removed. This is true whether you start with 10 dice, 100 dice, or a trillion dice. The probability of one dice to roll three or less is unaffected of how many other dice are next to it.",
"Flip a coin. It’s heads. Now flip it again - what are the odds you get heads again? 50% But what if you just flipped heads 99,999 times in a row? What are the odds now? 50% Atomic decay operates on the same type of probability. Half the atoms will decay in one half life, but a few lucky bastards will flip heads ten times in a row and survive for ten half lives. Surviving that long doesn’t make them more likely to decay later, there’s no “memory” of the past.",
"Regardless of the sample size, every minute there is a 50% chance that each atom might decay. When you take a random element like this with the huge number of individuals present in even one gram of atoms you see 1/2 of them decay after a second.",
"Nothing survived longer in the first sample than the second sample. You had 1.001 kg of Element X divided into a 1.000 kg sample and a 0.001 kg sample. After a minute you have 0.5005 kg of Element X divided into a 0.5000 kg sample and a 0.0005 kg sample. There was no variation in how long it took."
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nmh69t | how does sitting too much in a day reduce lifespan/kill you? | Biology | explainlikeimfive | {
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"Being sedentary doesn't necessarily reduce lifespan but it can increase incidence of heart disease depending on diet but this is not even true if said person who is sitting has an otherwise active lifestyle. The only real negative consequences of sitting too much is the potential for back pain and hemorrhoids.",
"It's statistics. Sometimes they're helpful but sometimes not. Statistically, if you spend 50% of your day sitting, then you also spend the other 50% being sedentary too. It doesn't factor in the reasons ppl have or what personal choices they might make. It doesn't apply to regular gym go-ers for ppl into fitness. It's just an average. Flying is statistically the safest way to fly but when the plane starts hurtling towards the ground, that statistic isn't going to make you feel better."
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nmhrsa | - have traditional cloud shapes changed from men altering landscapes or build large cities? | Earth Science | explainlikeimfive | {
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"The cloud SHAPES or the locations of the clouds? There is indeed an effect on the temperature of an area due to the heat island effect around large cities, and this could impact the convective activity directly overhead. And you will certainly see clouds forming where they usually wouldn't due to exhaust from power plants and such carrying warm moist air upward."
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nmjdi3 | - What Is Radio Squelch? | I've tried asking a few people in person but I haven't really gotten a good explanation. Thanks! | Technology | explainlikeimfive | {
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"Radio bands are \"noisy\"...there's always some constant background signal from random natural sources. We hear this as static on the channel, particularly for AM broadcasts (most commonly in the VHF used for hand-held and marine/aviation radios). \"Squelch\" is a function that basically says \"shut the speaker off if the signal is below a certain threshold\" so you don't have to listen to constant hissing. It goes totally quiet until a signal above the threshold comes in, then it turns the speaker on and you hear whatever it was that the radio received. The potential issue is that you'll miss weak signals...if the squelch is set too high, a weak real signal won't be strong enough to breach the threshold and you'll never hear it. If it's set too low, even the background static overcomes it and you have to listen to the static all the time. So you need to set it right and, periodically, check it relative to current conditions to make sure it's doing what you want."
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nmjlg7 | Why is it easier to froth milk when it is warm? | Physics | explainlikeimfive | {
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"The proteins in cold milk are tightly wound. When they warm up they loosen up. They can then form a sort of shield around the air being introduced by a steam wand or a beater. All of the little protein wrapped air bubbles piled on top of each other creates foam."
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nmjv75 | Why do human voices become more “gravely” with age? | Biology | explainlikeimfive | {
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"Vocal cords are muscles and muscles get weak with age. Or they get stiff depending on the person."
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nmkmu5 | fecal/bacteria transplants | Please explain what is happening during this procedure and why this is a good thing. | Biology | explainlikeimfive | {
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"Some people's digestive tract doesn't have the right balance of bacteria. So doctors can take my feces and transplant it into your digestive tract, hoping that the bacteria will grow and flourish and heal your malfunctioning gut. This actually works quite well in some cases."
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nml5yu | how do people supply their homes with water from a well? Can wells "run out" of water? | Earth Science | explainlikeimfive | {
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"Wells work by drilling a hole that's very deep, deep enough to reach the water table or aquifer. Wells can definitely run out of water. One way is if too much water is pumped up at once. Groundwater will only trickle into the well bore slowly, it takes time to fill the well bore back up. So you'll have water again, but you have to wait (also, don't do this, it's hard on your well pump which is expensive to replace). To help wells fill up faster, the well is drilled deeper and wider than is strictly necessary to allow more surface area for the water to trickle in to it. Wells can also go dry when too much water is removed from the aquifer in the general area. For example in California, so much water has been pumped from wells that people with shallower wells that used to work just fine simply don't get water any more. Those wells must be redrilled deeper to get back down to the lower water table.",
"A well usually sits at such a level that it will fill with groundwater (if that's the correct English word) usually this water isn't clean as tap water so you might wanna boil it. A well can run out if the water level drops due to a drought for instance.",
"In most places, you dig down deep enough and there’s water, even in deserts, you might have to dig deep. But eventually you’ll hit soil with a lot of ground water, these are called aquifers. Aquifers can hold massive amounts of water, and can be refilled by rain water seeping down, water seeping down from rivers/lakes, or water flowing in from surrounding aquifers. So wells just pump water up from deep underground. In most normal cases no, they rarely ever run out. But in times of drought, or when lots of water is being taken out for something like growing crops in an arid environment, then yes you can start to drain the aquifer, needing to dig deeper and deeper well, and eventually yes they could run out. But someone’s private home pump is going to be that significant compared to say a massive plantation."
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nml8g3 | Why does the sky turn green when there is a very high chance of Tornadoes? | Living in the Mid-West, I’ve noticed the sky, clouds, and the air in general all pick up a green hue, and it gets greener as the likelihood of a tornado rises. Why? | Earth Science | explainlikeimfive | {
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"The \"greenage\" or green color in storms does not mean a tornado is coming. The green color does signify the storm is severe though. The color is from the water droplets suspended in the storm, absorbing red sunlight and radiating green frequencies.",
"Typically the green is coming from the clouds being really tall. When clouds are tall, the storm has a lot of energy. Storms with a lot of energy have higher winds. These winds mean the updrafts can push tiny ice pellets back up into the cloud where it collects more water forming hail stones. Just like u/megadavex said, the water and hail refract the light. So tornadoes don’t cause the sky to turn green, but a green sky means some powerful stuff is coming that could form rotation, funnel clouds, and then tornados."
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nmloky | Why do you have to run lukewarm water on a minor burn for 10 minutes or so, how does that affect the skin and healing process? | Biology | explainlikeimfive | {
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"It works by removing latent heat and easing inflammation. So basically it cools the wound so it stops burning while also keeping the maximum amount of blood flow to it so as to start the natural healing process immediately when it’s most critical. However, ice cold water results in vasoconstriction (where the blood supply gets limited to the area). Where vasoconstriction occurs, important immediate healing effects are inhibited. A side note, we know for a fact that cool running water is optimum. Cold sprays and wet towels aren’t even close to as effective. The reason for this has yet to be determined, but it’s thought to be related to increased blood flow.",
"Lukewarm or cool water helps because it stops the burning process: your burn continues to worsen until the heat dissipates. Running water over it continuously ensures that the water stays at a cool temperature, since if you stick your hand under a towel or in a bowl of water it will warm up the water. It also helps prevent infection by thoroughly rinsing the burn. Cool water also reduces inflammation without the extremes of ice water than can lead to too *little* circulation, and relieves pain. Cold water or ice is a problem because: * The strong contrast can create more tissue damage * The cold will cause blood vessels to constrict too much, which may reduce healing * Depending on the size of the burn (and thus the area that needs cooling), cold water can (and has) lead to hypothermia Source: first aid training and I also literally just burned my hand two days ago (a brief scald from 200F steam), and the doctor and I talked about this. I ran cool water over my hand for 20 minutes, then a few hours later decided to go to urgent care and got silvadene (a burn cream). The combination of the two means that a burn the doctor thought might progress to second degree (blistering) has significantly healed to the point that I can touch it without any pain and almost all redness is gone."
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nmm79t | Why do some foods make you feel fuller or more energized than other foods with the same amount of calories? | Biology | explainlikeimfive | {
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"I am not a doctor, nutrition expert, or certified anything; all I am is an individual that has been studying and practicing running for a long time. Energy management is a huge deal for runners, and we obsess over what and how we eat and why food does it what it does. First, volume of food does not mean quantity of calories. Calories are a unit of measurement for energy. A good example is a pound of kale vs 20 jelly beans. Both are roughly 220 calories. Second, how fast that food is, or energy, is metabolized. The way I think of this is the candle, and the gasoline. If you have 1000 calories of gasoline, it will burn in about 3 seconds. Those calories are expended. The candle with 1000 calories will burn for about 10 hours. Your body does something similar (metaphorically) with food. Your body processes sugars very very quickly. Just like the gasoline, you get a huge burst of *available* energy. If you don't burn that energy, it gets stored in the blood. Then is filtered out and converted. When you do the same with Kale (like the candle) your body works harder to break it down to a substance (usable energy) that your body can use. Its composition is also more complex. What you have with is slow burn food that really doesn't get stored and doesn't give you that boost. You have still had 227 calories, bit for the massive e pile of kale you just ate is not digesting and becoming available to you immediately, and the act of digesting it pulls a ton of blood from your cardiovascular system (when you overeat, you feel sleepy because of this bodily mechanism) and it isn't a good feeling immediately. So, to make this a TLDR: The cheesecake is sugar and fat and more sugar. This is a fast burn energy where you feel good for about an hour, then your body has either burned those calories, or stored them. Now your body doesn't have those carbs ready to burn, and your body is running on fumes by hour 2. The good healthy meal is a slow burn that takes time to digest, and provides a steady release of energy and nutrients over time.",
"Your body has a defense mechanism against too much carbs(i.e. sugar, pasta, bread, etc). It creates a stuff called insulin. This has a secondary effect that it \"resets\" your hunger. If you eat alot of proteins or fats this does not happen."
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nmmime | What is happening in your brain during an episode of PTSD? | Biology | explainlikeimfive | {
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"Imagine the most stressful day you have had in your life so far. Do you remember dwelling on this and feeling that stress, at least in part, all over again? From personal experience, allow me to take this feeling you had and build it into PTSD. Now take that experience, make it worse. Make it a direct threat to your life, make it world altering and make it last. Make it hurt, make it vivid, and make it all against your higher thinking, and against your will. That stress hormone you felt in stress now floods your brain in quantities far beyond what the rational brain can handle. The stress takes these horrific moments and burns them into your memory. Not just the images, and ideas, and scenarios, but the feelings, the fear, the terror, and the pain. Fast forward to well after the event is over. You are at work and it is a quiet, non-stimulating environment, and a small snippet of that memory comes back to you and you are immediately in that moment. Your brain once again floods with stress hormone, just like that day, you are shaking, just like that day, your heart is pounding, just like that day. You can hear the things, see the things, feel the things. That is just a flashback. In between these episodes there is the constant, never ending paranoia its going to happen again. You are always watching for it, you are on edge. Your sleep and dreams are all related things. The first thing you think of when you wake up is the event, and every empty moment of thought is filled with conjecture and memory of the event. Nothing feels right ever. You are just living moment in between moments, afraid, and angry, and hurting. So when you are at the office, or grocery shopping, or just sitting at a traffic light, and those things, those memories and sensations come back, it is re-traumatizing. I have been in a situation where is was just sitting there and I was having an episode, and someone asked something and I almost snapped angrily, and I also almost cried at the same time; but you can't do that, they will think you are crazy, so you just smile like it's all okay.",
"I don't know about anyone else but I feel like I'm losing control of some sort of dangerous situation. I'm at once scared ,angry and confused because most of the time it's something that normally wouldn't bother a person. It's more confusing for my family because they're never sure what will set me off. I've never hurt anyone but the potential is there. It makes me afraid that I may do or say something I can't fix or apologize for. I don't even like to leave my familiar surroundings anymore."
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nmmiuh | Why can't they put carbon capture tech on top of coal plants? | We can already convert CO2 into oxygen right? so why not put that technology on top of coal plants? | Chemistry | explainlikeimfive | {
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"> We can already convert CO2 into oxygen right This is a chemical process that is essentially the reverse of burning hydrocarbons. Reversing the reaction means you have to replace all the energy that was released when you burned the hydrocarbons. Since some energy is always lost in the process of converting it from one form to another, burning and then \"un-burning\" hydrocarbons is less efficient than not burning them in the first place.",
"In general, carbon capture requires more energy than you can get from burning the things that produced that carbon dioxide. If you were clever you could probably filter out the carbon dioxide and store it as a compressed gas, but even that is not free. If the goal is merely to eliminate pollution, then it would be cheaper to switch to a carbon neutral power source than to capture all the pollution from burning coal and oil to produce the same amount of electricity. There are many options: solar, wind, geothermal, hydroelectric, tidal, fission, and fusion. Fission power is, in my opinion, the best alternative to coal that we have today. Uranium is superior to coal in every way that I have seen the two be measured. Uranium is safer, causes very little pollution, and can produce approximately 1 million times as much electricity as burning the same amount of coal would. Unfortunately, many people have an irrational fear of anything nuclear. I can go on about this in more detail if anyone is interested."
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nmn51u | How will the James Webb Telescope be able to see the universe in it's early days | I understand that light takes time to travel, therefore whatever we see is how that object looked in the near or far past. However if the universe is expanding faster than light how can telescopes like the JWST see light from way earlier? Wouldn't we just keep outrunning that light? Sorry if my question dosen't make any sense. | Physics | explainlikeimfive | {
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"It can't and will never see the light coming from outside the sphere of the observable universe. What it can do is give us better pictures of the light that came from points inside that sphere that are too dim for Hubble and other current telescopes. This means that we will get insight into the so called \"Dark Age\" before stars coalesced into large galactic clusters that are very bright. It's worth noting that the expansion of the universe is only faster than light at incredibly large, quite literally universal scales. Anything closer than that isn't traveling away faster than light."
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nmn9le | Why exactly will the sun expand? | I'm trying to learn more about astrophysics, and one thing I can't wrap around is how the sun and other stars will expand near the end of their lifetime. The reason people give is that when the hydrogen in the core depletes, a star fuses heavier elements together and therefore the inner pressure "wins" against gravity. What I don't really understand is how fusion of heavier atoms would increase the pressure. Wouldn't that mean that fusing them together creates more energy than the fusion of hydrogen? Which isn't true if I understood fusion correctly. | Physics | explainlikeimfive | {
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"You have it backwards. The higher pressure *causes* the fusion of heavier nuclei (not atoms - electrons don't stick to nuclei at the temperatures found in stars). More precisely, the chain of events looks like this: * Before a star is born, a hydrogen cloud slowly collapses under its own gravity. Initially, this raises pressure and temperature at the center. * Once the pressure and temperature at the center get high enough, hydrogen fusion ignites. That fusion produces a lot of energy, which makes the core very hot. And as you probably learned in high school chemistry, heating a gas increases the pressure it exerts. (Okay, technically the material here is a plasma, but the same laws more-or-less apply.) * Because higher pressure increases fusion rate (and thus energy output) and lower pressure decreases it, the inward pressure of gravity and outward thermal pressure reach a stable equilibrium. * This stable equilibrium lasts throughout the star's time on the main sequence. As fusion products (mostly helium nuclei) build up in the core, the fusion gets less efficient, which means gravity wins out just a little, increasing the star's core temperature until the outward pressure rises enough to counterbalance it again. From the outside, this manifests as stars getting slightly hotter (and thus slightly larger, since the higher temperature puffs up their outer layers) as they age. * Near the end of the star's life, so much helium has built up in the core that hydrogen fusion slows down enough that the core collapses to a very high density, much higher than in previous stages. What happens then depends on the star's size: If the star is quite large (about twice the size of the sun or more), this is enough to raise the pressure and temperature enough to ignite helium fusion, which raises the star's energy output and re-establishes the equilibrium that had persisted throughout its time on the main sequence. But for smaller stars, we need a little more physics. Up until this point, the thermal pressure from the extremely high temperatures from the energy released by fusion has been the dominant force holding a low-mass star up. But as the pressure rises higher and higher, the nuclei in the core begin to physically run out of space. It's a general rule of particle physics that two particles (more properly, fermions) can't be in the same place at the same time *at the same energy level*. So when the space runs out, the nuclei in the core have to jump up to higher energy levels - they can no longer stick around in their ground state. (Imagine, say, a stadium that fills up so people have to start sitting on each others' laps.) Pushing particles up to those higher energy states, and keeping them there, \"consumes\" some of the pressure that would normally be compressing the matter further - or, as we usually think of it, results in an extra outward pressure on top of the thermal pressure that has been involved so far. This extra outward pressure is called *degeneracy pressure*, and it quickly comes to be the *main* force stopping further collapse (outstripping the thermal pressure pushing outward). This continues until the pressure and temperature get so high that that helium fusion ignites. But *unlike* the earlier ignitions, this ignition *doesn't* immediately establish an equilibrium, because thermal pressure is no longer doing much. If you have 1000 units of degeneracy pressure and 1 unit of thermal pressure, then even heating the core by a factor of 100 doesn't change things much - you go from 1001 units of total pressure to 1100. So once fusion ignites, there's a temporary runaway reaction that isn't stopped by a new equilibrium for a relatively long time in particle physics terms (a couple of minutes). This is called a *helium flash*, and for those couple of minutes, the star produces energy at a rate comparable to whole large galaxies. Eventually the flash makes the core so hot that thermal pressure once again becomes the main force, reestablishing the equilibrium. In either case: * Now that helium fusion is lit, the outward pressure from fusion (possibly assisted by degeneracy pressure depending on the star) re-establishes the equilibrium from earlier - but the output of the now-very-compressed core is much, much higher. That causes its outer layers to puff out, since there's more outward push from the energy flowing from the core. (This actually makes the star's *surface* cooler, because it's spreading an increased energy output over a drastically increased area.) The star is now a red giant."
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nmoree | CPU chipsets | Is the chipset on the CPU or based on the motherboard? Like say an A320, is an older chipset for motherboards and cannot support ryzen 7's? Is it basically like a platform for CPUs, and the older chipset sometimes/most of the time accept the newer CPUs? | Technology | explainlikeimfive | {
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"> Is the chipset on the CPU or based on the motherboard? The chipset is physically based on the motherboard. They control communication between all the other components of the computer, allowing the CPU to work with everything else. Their design is done by the designers of the CPU (AMD or Intel) but are necessarily on the boards made by third parties. A given chipset is typically designed to be compatible with at least a few future generations of CPU, until they advance far enough that legacy chipsets can't support their features. This was an issue with AMD early in their CPU market share revival, as they were advancing quickly enough that chipsets had a very brief lifespan causing motherboards to have very narrow compatibility."
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nmpp6v | What is Double Fertilization? | I'm a high school student and we had this new topic about plant cycles, pollination, germination, etcetera. It introduced Double Fertilization but because I'm not used to plant vocabulary, I can't understand it at all. Please help! | Biology | explainlikeimfive | {
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"One sperm fertilizes the egg which will become the baby plant. An extra sperm fertilizes the leftover sex cells that were created alongside the egg. This becomes the endosperm. Think of endosperm being functionally like egg yolk, it sits inside the seed and holds all the nutritious bits for the baby plant to eat once it finally starts to grow."
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nmpysy | Why do people need physical therapy after being in the ICU? | Biology | explainlikeimfive | {
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"Physical therapist here: They say that every day of bed rest in the hospital takes about three days to recover. While in the hospital (especially the ICU) you usually spend your entire day in bed so that your organs can recover and that you receive the rest needed while the nurses watch your vitals and ensuring that you are responding to your medications and treatments the way that you should be. Until about 10 years ago, patients would spend literally their entire hospital stay without really ever getting out of bed, and their muscles would atrophy so fast that it would take weeks or months to recover back to an independent lifestyle. Within the last few years there has been research to prove that early mobilization in the hospital is essential to a fast recovery because you start to get your blood circulating, muscles pumping, and weightbearing through your bones and joints. In fact PTs nowadays will go in to treat most patients while in the hospital (unless they have specific orders not to, such as if their lab values are out of whack: for example if a person has super high sodium and they do too much exercise they could be at risk for a seizure). This even includes patients who are intubated or are unconscious in a coma, in which we will typically support them in standing so that they can get some of those benefits of being upright. To continue on this point, I am seeing a patient at my neuro outpatient clinic who was in a coma for a month and a half and he came out with no function of his shoulder down to his hand, and he can hardly stand even with support- this was a result of not moving around very much while in the coma, because the hospital he was at did not allow visitors due to COVID (and oftentimes when a patient is in a coma, family members will help keep the body moving through passive range of motion when the nurses or PTs are not moving them around, which is super beneficial so that the joints and muscles do not become stiff and tightened up). That being said he is starting to regain function in his hands and he is able to walk again with a walker (I’m so proud 🥲). Hope that helped answer your question! Tl;dr: muscles lose their function quick if they don’t do anything, which means it takes longer to recover",
"Muscles do atrophy that quickly. If you break an arm or leg, you can see how small your muscles are after the cast is removed. It is noticeable after even a few weeks."
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nmr76r | how do bees stop their wings from getting sticky and preventing flying? | Other | explainlikeimfive | {
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"Bees are not rolling around in honey. Hives are sticky to humans because our big meaty hands and tools sink into the wax and release all the honey. But bees are very neat. Honey just leaking around is honey that is going to waste—and given how much work it takes to make honey—bees dont want this. The honey life cycle goes like this: Bees collect nectar from flowers and store it in their gaster (special organ before stomach for holding food). Bee regurgitates a teeny tiny but of nectar into a wax cell and beats it with the air from its wings. The water in the nectar evaporates and slowly it becomes honey. Bees continue to deposit nectar until the cell is filled them they seal the cell with wax, called “capping.” When they need to eat the honey the bees will use their mouth parts to cut a small hole in the wax cap, and then use their proboscis to suck out the honey they need. Generally they will mix honey with pollen to feed to growing bees. When done the bees will seal the wax cell back up. So at all stages the only part of their bodies that generally comes into contact with the honey is their mouth parts. If they do get honey on their wing, if its a little bit theyd just clean it off with their mouths. If its a lot then the bee will probably just die and be removed from the hive. But again, this should be rare as the honey should be well contained and the hive kept clean. A bunch of sugar just sitting around will attract pests and bacteria and bees dont want that. So long story short, bees avoid getting covered in honey by bring very neat and storing their honey in sealed containers."
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nmrz9t | . If mature red blood cells don’t contain DNA since they don’t have a nucleus unlike normal cells, then how do blood samples provide DNA evidence? Is it due to matching proteins? | Biology | explainlikeimfive | {
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"Answer : there is more to blood than red blood cells and it's these other components that contain the DNA.",
"Blood isn't just red blood cells! Most of the cells in it are red blood cells, which don't have nuclei, but there's plenty of white blood cells which have nuclei. This is how you get someone's DNA from their blood. [Here's an illustration]( URL_0 ) of the different kinds of cells found in blood. Erythrocytes (red blood cells) and platelets are the ones without nuclei.",
"DNA extracted from blood comes from white blood cells. Those are the only part of your blood that contain DNA but there are thousands or tens of thousands of them per microliter of blood, so even the tiniest drop of blood will contain plenty of white blood cells.",
"Red blood cells are only one part of your blood. Generally dna is extracted from cheek cells or white blood cells"
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nms1a9 | Why can't a sine and cosine angle be greater than 1? | I've tried looking for the answer in Google, but I can't seem to understand it completely nor simplify the answers that I found. I was wondering if someone could explain this to me in much simpler terms. Thanks in advance guys :) | Mathematics | explainlikeimfive | {
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"Start with the unit circle -- a circle of radius 1 [in whatever units], centered at the origin. Draw this. Pick a point on the circle and draw the radius to it. Also draw the vertical line to the x-axis, and the horizontal line to the y-axis. The angle is measured from the positive x-axis counterclockwise around to the radius. By definition, the height of the point above or below the x-axis is the sine of the angle. Likewise, the distance of the point left or right of the y-axis is the cosine of the angle. Now, no point on the circle can be more than 1 from the center; the most the sine and cosine can be is 1 (or –1). What about bigger circles? Then the sine is the ratio of the height to the circle's radius, and similarly for the cosine. So, if the point is at coordinates (x,y), the radius is r = sqrt[x^2 + y^(2)] by the Pythagorean Theorem. And the sine is y/r while the cosine is x/r. Again, the magnitude of these ratios is guaranteed to be less than or equal to 1.",
"The sine of an angle is the ratio of side lengths between the side opposite to the angle and the hypotenuse of a right triangle with the given angle ([picture]( URL_0 )). The cosine is the same thing except with the adjacent side and hypotenuse. The hypotenuse (the side opposite the right angle in a right trisngle) is always the longest side. To prove this is more difficult but if you can accept that as truth then it follows that the sine or cosine of an angle can never be greater than one since they are both a ratio x / h (where x is the opposite or adjacent side to the angle and h is the hypotenuse) where h *must* be longer than x. So the fraction can never exceed one.",
"Imagine you're driving in a city with a grid layout. To get somewhere, you need to go (say) north 3 miles, then turn, and go east 4 miles. Now imagine you have an aircraft, and you can fly to the same place directly, ignoring the grid. That's 5 miles. Cosine/sine is the individual north or east distance divided by the total distance - so 3/5 and 4/5 here. Its never more than 1. If it was, it would mean going north 3 miles, then going east some other distance would bring you *less* than 3 miles from where you started, instead of taking you further away."
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nmsglc | How does a refrigerator work? | Technology | explainlikeimfive | {
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"text": [
"Expanding gas cools as it expands. First law of thermodynamics. Inside a refrigerator is a reservoir of refrigerant. This is a gas that is compressed into a liquid, as a liquid is a good way of storing a large volume of gas. The system allows the liquid to slowly bleed out of the reservoir. Where it expands rapidly into a gas, cooling as it expands and circulates. Providing refrigeration. At the other end of the system, a compressor sucks in the gas and compresses it back into a liquid in the reservoir. As the system runs the compressor gets hot, and you can get condensation inside the refrigerator. The condensation can be redirected out of the refrigerator to drop onto the hot compressor, where it evaporates."
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nmt1il | How is electricity able to cool spaces (e.g. fridge, freezer)? | I'm quite embarrased for asking to be honest. No one has been able to provide me an explanation that I comprehend. I'm by no means unfamiliar with how electricity works. Based on the knowledge I have, electricity is able to provide heat due to friction, but how can we make somethong cool down? Thanks in advance x | Physics | explainlikeimfive | {
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"It's hard to explain simply because there are a lot of thermodynamic processes involved, but I will try my best. A fridge or freezer works by having a coolant running in pipes or channels inside. This coolant vapourizes at low temperatures, lower than normal room temperature. This means that the coolant can absorb heat from the air inside the fridge. When this happens the temperature of the coolant increases enough so it is vaporized. The coolant vapour is then fed through a compressor (it's here the electricity comes into play). When a gas is compressed it's temperature is increased. So running the coolant through the compressor increases the temperature of the vaporized coolant even more. This makes the vapor significantly warmer than your normal room temperature which allowes the heat in the coolant vapour to be transferred to the air in the room where the fridge is standing. Heat can only be transferred from a warmer to a colder place, that's why the coolant vapour has to increase it's temperature in order to get rid of the heat it has accumulated. When the heat is transferred away from the coolant it's temperature decreases. The colder coolant vapour is then fed through a condensor which allowes the vapour gas to expand. When a gas expands it's temperature is lowered (the exact opposite as to when you compress a gas). When this happens the coolant vapour again becomes a liquid and has a temperature below normal room temperature and is ready to absorb heat from the air inside the fridge. A freezer works in the same way. Also a heat exchanger does this too. You can also heat things up this way by reversing the entire process.",
"The electricity itself doesn't cool it down but is used to move things like cool fluids or gases (or one turning into the other in a cycle depending on your machine) around through tubes in the walls of your fridge or freezer that then absorb the surrounding temperature and bring it down."
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nmtnw3 | what is the difference between olive oil for "warm use" or "cold use"? | Other | explainlikeimfive | {
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"text": [
"Answer: certain components of the \"Cold use\" olive oil have a lower \"smoke point\". That's the temp when it begins to smoke instead of just \"thinning out\" like many oils do when heated. \"Cold use\" oil has a lower smoke point. It also happens to be healthier, although when heated, the healthy parts actually go through chemical reactions and are no longer healthier. Also pressing olives produces more \"warm use\" oil than \"Cold use\" oil, so there's an economic value in upcharging the cold use."
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nmttgz | How does trauma change our brains? | Biology | explainlikeimfive | {
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"The answer pretty in depth. In basic terms the amygdala becomes active with fight or fright signals. The frontal lobes can not rationalize the “danger” and allows the amygdala to continue in a heightened state of alertness. This can be a one time event like a plane crash. Or it can be a repetitive trauma such as emotional abuse form parent to child. I highly recommend this book fo survivors of trauma and for those who care for trauma survivors. The Body Keeps the Score: [The Body Keeps Score: Brain, Mind, and Body in the Healing of Trauma ]( URL_0 ) by Bessel A. van der Kolk M.D."
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nmujjf | When we take a pain reliever for something like a headache, how does our body know to send the medicine to our head? If we had a headache and a sore knee, would both benefit from the meds? | Chemistry | explainlikeimfive | {
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"When you take a painkiller, it is broken down in your stomach and usually travels through your bloodstream, from here, it can go to your brain and other parts of your body. When you hurt yourself, or have a headache, your brain sends and receives signals that tell you that you're in pain. The chemicals from the painkillers that are now in your blood work by either reducing the signals that are being created by the source of pain, or, they prevent these signals from being processed by the brain. So, if you were to take a painkiller to help with a sore knee and a headache, the drugs would alleviate the pain from both places because it isn't being sent to the source of pain, necessarily.",
"Depends on the kind of painkiller. Ibuprofen works by reducing the inflammation to the affected area. Paracetamol works by stopping pain signals in the brain but pharmaceutically we don’t actually know by what mechanism. Source: I was a pharmacy tech for a few years but I’m sure others will be far more educated than me so happy to be told otherwise. That’s my simplified understanding of it."
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nmvkdn | Why is Iron the boundary between nuclear fusion and fission. What makes it so unique? | Physics | explainlikeimfive | {
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"That has got to do with the binding energy of the core. Now what is binding energy? It's essentially the energy that you need to break a core apart. Now why is that important, well one could assume that the weight of a core is the same as the sum of weights of it's consituent parts, but it isn't. The core is usually lighter than the sum of it's parts, which is call mass defect. Now according to Einstein and his famous formula E=mc², mass (m) and energy (E) are directly related through a constant (c=speed of light), so you essentially a difference in energy between the core and what you'd get if you break it apart. Which is aptly called the \"binding energy\". So it's essentially the energy that you get by having a core over having parts. Meaning the creation of the core released energy and to break apart the core you'd need to resupply it with energy. So if you look at the graph displaying the binding energy of cores per nucleon (parts of the core), you'll find this: URL_0 So if you take 2 hydrogen atoms (consisting of a proton and a neutron) with a binding energy of ~1MeV per nucleon and fuse them to make helium (consisting of 2 protons and 2 neutrons or the the stuff in 2 hydrogens) then you realize that you went from 1MeV/nucleon for ²H to 7MeV per nucleon for ⁴He. So you start from 4 nucleons at 1MeV = 4MeV to 4 nucleons at 7MeV = 28MeV now removing the 4MeV to break up the hydrogens you get 24MeV of energy from that reaction. Consersely if you break idk U235 into Ba142 and Kr91 the difference is much smaller let's say U235 are very roughly around ~7.5MeV and the other two are very roughly ~8.5MeV than you'd get a ~1MeV per nucleon which sounds like way less but you'd get that 235 times. So as long as the result of either fusion or fission ends up having a higher binding energy than the stuff you fused or broke apart you would gain the difference in binding energy. However if you look closely iron is the core with the highest binding energy so both fusion and fission would require not provide you with energy.",
"The size of the nucleus, which directly comes from how many protons and neutrons are in there. Protons are forced apart by the electromagnetic force because they're all positively charged. They're also attracted by the strong nuclear force, which is much stronger, but drops off much more quickly over distance. So you need the particles to be close to attract each other, but you also want as many particles as possible so there are many interactions. At some point there's an optimum size, and any more particles would destabilize the system because they add a lot of electromagnetic repulsion while not being close enough to the others to contribute much to the strong nuclear force.",
"The key here is a concept called binding energy per nucleon. Binding energy is how much energy is associated with the forces holding an atom together, in order to completely rip an atom apart into its constituent parts (nucleons) you need to overcome the binding energy. In any nuclear reaction, the energy released (or taken in) will be the difference in binding energy of the initial particles and the final particles. So when hydrogen fuses into helium, the energy released is the difference in binding energy between 4 free hydrogen nuclei, and 1 helium nucleus. You'll notice that 4 hydrogens had to combine to make 1 helium so its useful to think about the binding energy per nucleon to account for this. The binding energy per nucleon of hydrogen is lower than that of helium so energy is released when you fuse hydrogen in to helium. Now if you graph binding energy per nucleon for different nuclei it peaks at Iron, this means that iron has the highest binding energy per nucleon, then it goes down slowly as the elements get heavier. Remember for a process to release energy the final binding energy needs to be greater than the initial binding energy, so fusion of elements up to can release energy, but after that they take energy because the binding energy per nucleon is going down. Similarly for heavier elements they can fission and release energy until you reach iron, at which point it would take energy."
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nmvohf | Why is it that when you have a hypothetical argument in your head you can think of great points and come up with awesome rebuttals but irl your arguments are shaky at best? | Other | explainlikeimfive | {
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"Because in your head you get to form the argument to which you're replying, which is not how conversations with other people work.",
"Because other people have points and rebuttals your mind can't imagine. You imagine their arguments, but they are all but your own. \"I've heard this argument before\" Yes, but you didn't progress through the argument, the next line coming from the imaginary counterpart is entirely your own. You're essentially beating yourself in a debate, both the victor and the loser at once. Its essentially the first counterargument you come with that can be clever, and those occur just like when you suddenly remember something. That is on the other hand a mystery. I believe its something to do with your two hemispheres in the human brain. One half of your brain has no concept of language, imagination and as such can be seen as a strictly logical machine. Perhaps it's what we regard as our subconscious.",
"Because coming up with a good argument takes time and practice. That argument you have in your head isn't produced in the split second you have before being any slower makes an IRL argument your loss. It's produced over quite a long time, probably a good few minutes but maybe even an hour or more of combined thought, and even then the argument in your head is probably still really incoherent and bad when put to paper.",
"I mean not only is your brain constantly working on making those great argument even if you don't directly think about them. It's also your \"home crowd\" who gets to decide whether the argument is good and let's say you might be biased on that one.",
"Same reason you can picture an amazing painting in your head but wouldn't be able to do it in real life without lots of practice. Debate and communication are skills that need real life practice to realize your thoughts as such.",
"Because the rebuttals to your argument in your head are actually all parts of your argument, too. Even moreso, they're parts of the *framing* of your argument. Frequently, when arguing with someone else, you realize they have such a different viewpoint that many of the assumptions of your argument have to be reexamined. Let's say you had an argument about efficiency, and were absolutely certain that your argument had addressed any possible concerns about maximizing efficiency. You might even be able to prove it. Then you encounter someone who asks about redundancy and resiliency and if those are lost in the pursuit of efficiency. Someone else may ask about the importance of choice, and whether inefficient choices should be constrained, and the consequences of that. In short, you may wind up in a broader argument than the one in your head.",
"I would think environment has a lot to do with it too. In the \"hypothetical argument\" you are in a safe, familiar space with no immediate threats. Versus the \"real life\" scenario where there is more unknown, more stress and less control. These stressors can hinder your ability to think quickly and clearly as well as it give your emotions a chance to get the better of you."
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nmwla6 | Why does 4K on youtube look better than 1080p on a 1080p monitor? Theoretically it should look the same because the monitor can only display 1920 x 1080 pixels max. | Technology | explainlikeimfive | {
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"More data All video is compressed, some more than others. When you ask for a 1080p video, YouTube sends you the file that has been compressed with settings that should looks pretty good on a 1080p screen, it won't be as good as the original and there will be artifacts you can pick out but it'll be about 1/100th the size which is good for their servers and your internet connection. When you ask for the 4k video it sends you the file which would look pretty good on a 4k screen, but to keep it looking pretty good they have to send more data which means its a bit closer to the original. Your TV/computer takes the 4k data and goes \"I can't use that, let me shrink it down\" and gets to take all that extra data to create finer details on the 1080p screen that weren't included in the much smaller 1080p video stream. If you were to watch your bandwidth usage this would make sense too. Streaming a 1080p video for an hour might be 2GB while a 4k video is 7GB. That 3x increase in data results in an increase in fine detail on the screen. For reference, uncompressed 60 fps 4k video should be around 5TB per hour so we really squish it down so you can get it without crushing the server, your network connection, and even your own computer's ability to process data.",
"The way Youtube works is that it allocates a certain amount of bandwidth to each quality of supported video. Since 4K allows much higher bandwidth than 1080p compression artifacts will be reduced and so the video will appear higher quality, even when shown at the same resolution.",
"There is a little dirty secret of common digital video: the image is sent in 3 \"layers\": a brightness layer, and 2 colour layers. You might think the 3 layers would be Red, Green and Blue but they're not. If you blanked out the two colour layers you would basically get a black & white image. .. However, for a 1080p video the colour layers are actually sent at 540p resolution. For every 2x2 of pixels the basic colour is the same and only the relative brightness varies. This is one of those \"your eyes can barely see the difference\" things that really saves disk space/bit rates, but has a permanent impact on image quality. This does mean, however, that a 4k resolution video would have 1080p resolution colour layers. When the 4k video is downscaled to 1080p you effectively have full colour information for each individual pixel. This can subtly improve image quality.",
"4K downscaled will always look better than 1080p because it is essentially averaging four pixels for ever pixel resulting in antialiasing and truer colors. Throw in data compression on videos and you end up getting less compression artifacts, as you have more “blocks” that are used for motion vectors in compressed video on top of the pixel averaging",
"People say bandwidth. But in reality, it’s because of chroma sampling. Digital vídeo usually is represented with 4:2:0 colorspace. That means that for every 4 pixels, the video file only stores information about how bright the pixel is for all 4 pixels. It only stores an average of the 4 pixels into 2 pixels for color information. Without getting into the whole chroma/luma Blackhole, a 4K video has twice the color resolution of a 1080p video when the 4K is scaled down to 1080p",
"It reminds me of when blue rays first came out and every time you watched a DVD they also had an ad for Blue Ray where they showed this stunning video of how great the quality was on Blue Ray and how crappy the quality was on DVD... but the thing is, it was on a DVD, so what they were really showing was how good the quality of DVD actually is when done properly. And that is the thing with 1080p, it is an amazing picture quality when used properly. So often the sources of media we get in reality via streaming and even expensive cable television isn't even proper 1080p, so the upgrades to 4K and even better quality of devices, isn't usually worth it (although 4K is standard now anyway, so you can't really pay less for worse)."
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nmxwy3 | (Sonoluminescence) Nobody knows origin of the light when an underwater bubble is collapsed or are the understanding of its precise origins still uncertain? | Physics | explainlikeimfive | {
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"No, that's a fair statment. We don't have a scientific consensus at all on that one. Good data on the phenomenon exists but basically no experimental data from testing any of the numerous hypotheses out there. No one has the answer yet."
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nmz3ig | Why are things funnier in threes? Is it the same in other languages or cultures? | I’ve heard of the Rule of Three for writing comedy but don’t really understand why it works, or why 3 is the magic number. Also curious if it works in other languages or cultures. | Other | explainlikeimfive | {
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"The thought behind it is that after three occurrences, people become annoyed or bothered! The first time it catches you off guard, the second time you catch it faster and appreciate it, and the third time you’re really “in on” the joke. Anything after that and it wears on ya. 🙂"
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nn0kfo | On a deeper level than “oil repels water so the water with detergent can’t get in to break up the stain,” why are grease stains so hard to get out of clothes? | Chemistry | explainlikeimfive | {
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"Water is \"polar\", which means that one side of the molecule has a positive charge and the other side has a negative charge - like a north pole and a south pole. This makes water a great solvent for polar materials, since it can \"grab\" them very easily (like a magnet grabbing iron dust). Grease is \"non-polar\" - basically they're neutral, instead of positive and negative. Water can't really grab it - it would be like trying to use a magnet to pick up plastic. The simple rule for this is \"like dissolves like\": materials will dissolve other materials which are like them. That means that polar materials are crappy at dissolving non-polar materials."
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nn0nzt | Why do airplanes collide midair if there aren’t that many planes, and the sky is huge? | Other | explainlikeimfive | {
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"Many fights come from and go to the same airports, which means that lots of planes are using similar flight paths. If they were freeform flying from anywhere to anywhere, then there would be much less risk since they'd be following a million different paths. But since there are relatively few starting points and ending points, more traffic is compressed into less routes.",
"Planes don't collide in midair very often at all. Small planes are more frequently involved, there are only 13 collisions documented in the last 20 years on the Wikipedia [page]( URL_0 ). While the sky is large, the fraction of the Earth covered with runways is very, very small. Planes wishing to use a runway have to fly through the same, small region, of the sky.",
"1) There are loads of planes in the sky, at every moment of the day (and night) 2) Most airplanes fly certain heights as they have “ideal” layers to fly in (less turbulence from clouds etc) 3) Airplanes fly shortest routes between destinations (if possible) to save fuel 4) Airplanes have to fly to an airport a certain way to make sure they can land on the right runway With all these planes flying in quite close proximity to each other sometimes (especially in busy places like near major airports), sometimes an accident happens: two airplanes might fly on the same “layer” (height) or the same route and crash.",
"There's a couple facts missing in your thought process. First, there are only certain places aircraft can land and take off from. Just like interchanges on the freeway, this creates points where traffic gets bunched up from all the planes trying to take off and land. So necessarily you will have major flows of planes in a straight lines between major airports. Which brings us to our second point, planes (especially over long distances) fly in specific corridors to help better regulate the flow of traffic in between major airports. Included with that is planes fly set altitudes in these corridors for the same purpose of regulation of traffic."
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nn1cg6 | why is it harder to wink with my right eye compared to my left? | Biology | explainlikeimfive | {
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"I don't know the answer to this question but I'm one of the few who can't wink at all, with either eye. Lol."
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nn2366 | What is physically different between a high-end CPU (e.g. Intel i7) and a low-end one (Intel i3)? What makes the low-end one cheaper? | Technology | explainlikeimfive | {
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"The process to make computer chips isn't perfect. Certain sections of the chip may not function properly. They make dozens of chips on a single \"wafer\", and then test them individually. Chips that have defects or issues, like 1/8 cores not functioning, or a Cache that doesn't work, don't go to waste. They get re-configured into a lower tier chip. In other words, a 6-core i5 is basically an 8-core i7 that has 2 defective cores. (Just for reference, these defects and imperfections are why some chips overclock better than others. Every chip is slightly different.)",
"Through history occasionally are devices where a high end and a low end were similar, just had features disabled. That does not apply to the chips mentioned here. If you were to crack open the chip and look at the inside in one of [these pictures]( URL_0 ), you'd see that they are packed more full as the product tiers increase. The chips kinda look like shiny box regions in that style of picture. If you cracked open some of the 10th generation dies, in the picture of shiny boxes perhaps you would see: * The i3 might have 4 cores, and 8 small boxes for cache, plus large open areas * The i5 would have 6 cores and 12 small boxes for cache, plus fewer open areas * The i7 would have 8 cores and 16 small boxes for cache, with very few open areas * The i9 would have 10 cores, 20 small boxes for cache, and no empty areas The actual usable die area is published and unique for each chip. Even when they fit in the same slot, that's where the lower-end chips have big vacant areas, the higher-end chips are packed full.",
"Most reply seem to focus on a process often called binning: disabling and rerouting defective or underperforming parts of a chip to \"act\" as a lower-spec config. However, this only works for specific lines of processors - in GPUs you often see this happening between the top-tier and sub-top tier of a line. For the rest of the range, chips are actually designed to be physically different: most chips are modular, cores and caches can be resized and modified independently during the design process. Especially stuff like cache takes up a lot of space on the die, but is easily scalable to fit lower specs. Putting in and taking out caches, cores and other more \"peripheral circuits\" can lower the size (and fail rate) of chips without needing to design completely different chips. & #x200B; edit: use proper term, no idea where I got \"harvesting\", binning is def. the proper term.",
"Most of the answers in this thread are incorrect, at least for the processors mentioned by OP. Intel Core processors vary in core count and cache size across the range, if not in actual architecture.",
"Guys, binning and architecture are not the same thing. Binning is used to determine the clock speed of a chip within the same family. The differences between i3 and i7 are not just limited to core/thread count. It's also architectural. These have different features on the die that determine their capabilities.",
"Imagine the job you want your processor to do is eating food. You know how I eat faster than you do? Part of that is having a bigger mouth (L1 cache), using bigger silverware (L2 cache), and having a larger plate (L3 cache). It's also about making sure that I'm taking the right size bites, constantly chewing because I make sure that the next bite is ready to go into my mouth by the time I'm done chewing (hyperthreading and pipelining).",
"In many cases, they are the same physical chip. The i3 just has defective sections turned off or slowed down. It's cheaper because selling a partially functional chip at a discount is better than just throwing it away.",
"Imagine a fancy bakery. Their main customers expect nothing but the best cakes possible, and they make them. Every so often, they'll mess up the frosting, and the entire cake isn't worth the price. So instead of throwing the cake away, they'll repackage it and sell it cheaper instead. Non ELI5: A CPU is just a lot of silicone transistors. And i mean a LOT. Billions even. Imagine a sausage made of silicone, about as wide as your palm, which then gets sliced into thin discs called wafers. There's multiple chips on one wafer. Silicone isn't perfect, and often, there'll be a crack or imperfection right on top of a chip. So instead of throwing the whole wafer away, they'll use what they have, and sell it cheaper. Silicone is ridiculously expensive, so they have to use every little bit they can. EDIT: It's silicon, not silicone, I'm baffled by how I messed it up",
"Usually i3/i5 are chips that aren’t good enough or has damages so it can’t be sold as i7. Design wise they are usually the same. Every die is tested and depending on its property it could become an desktop or a mobile chip with 4 to 8 cores with or without igpu. Usually the parts that aren’t used will be disconnected from the rest of the die, got some rare cases when they didn’t do it and you could upgrade cpu/gpu via firmware if you got lucky On a silicon wafer usually center yield the best quality, and especially in the corner the quality is usually lower resulting in more cpus where not all cores are working",
"Imagine tiny guys working in your CPU. The i7 has more tiny guys that can work at a faster speed, the i3 has much fewer that work at a lower speed.",
"i3-10100 die area is 125 mm², i7-10700 is 200 mm² so the i7 chip is almost twice as big. They use the space fore more cores and more cache.",
"To give a very simply answer, size. An i7 is much bigger than an i3. A CPU is made up of transistors, the more transistors you have, the faster your CPU. An i7 has way more transistors than an i3.",
"The basic differences between a top-tier CPU and a mid or low-tier one are going to be in clock speed, cache size and internal optimizations. Core count also is a factor, but not as much as one would intuitively believe. The lower-tier variants can't handle as much memory and their internal cache will be smaller, meaning it has to do more moving data around to work on it. If you want a very rough analogy, a core i3 is a base model, a core i5 has some nice options added like a turbo, and a core i7 is fully loaded with a better engine that has more power. In reality, the die is the same for all of them and what options are available are dependent on manufacturing- if they don't perform up to spec, some options and features are disabled and it's sold as a lower-tier chip.",
"Silicon area is expensive. Chip design is expensive. To make the numbers work, intel makes building blocks of chip parts and can \"print\" different versions. A 4 core chip takes up half the wafer as a 8 core chip and thus costs much less. There is a fixed cost to process 1 wafer. If you can squeeze more \"CPU\"s on a wafer they are cheaper to make. This is different than having a 16, 12, 10 or 8 core design of a family where 'bad\" cores are marked unused and sold as lower core count. Those chips still take up the silicon area of a 16 core chip, but instead of wasting them, the sell them with lower cores. The other cost reduction is \"binning\" where they test the chip at the full rated speed. if it does not pass they test it at a slower clock speed. And keep dropping the speed until it passed. These lower clocked parts are sold cheaper because they can't run at their design speed. There are lots of ways to save money once you made the chip. But silicon area is the main driving factor. Which is why they are always shooting for smaller transistor sizes. Not just because smaller transistors can reduce power use, but smaller process size means they can put more chips on a wafer.",
"Other than arbitrary pricing in a non-competitive market situation, the main thing that affects CPU pricing is the **number of non-defective CPUs per wafer**. CPU manufacturing starts with a big cylinder of silicon. That cylinder is cut into discs, or wafers. That wafer is then engraved (via secret magics) with as many CPUs as they can fit. They can't make bigger and bigger wafers, because that original cylinder of silicon still has to obey the laws of physics and thermodynamics and cools differently in the middle vs the outside. Imagine the difficulty of making a cupcake vs. a giant cake, where if you don't do it juuuuuuust right, the outside will be burnt while the inside is still raw. All else being equal, the more features a CPU has, the more transistors it requires, the more space it takes up on a wafer. More space = fewer CPUs per wafer. Furthermore, the more transistors a given CPU has, the greater chance of a defect being in there somewhere. Defects = > fewer CPUs they can sell per wafer = > higher costs. The main high-level feature differences between i3, i5, and i7 CPUs are clock speed, # of CPU cores, and size of the cache. # of cores and cache are basically directly responsible for the size of the CPU on a wafer. An i3 with 2 cores and 256K of cache will take up far, far less space than an i7 with 8 cores and 8MB of cache. Less space means more CPUs per wafer means less cost per CPU. Others have touched on the idea of binning where an i7 with 2 out of 8 defective cores is sold as an i5 with 4 cores or something like that, but that's really secondary. Being able to make an i5 out of a partially defective i7 helps them recover waste from a wafer full of i7s, but that's far, far less important than being able to get 2x as many i5s out of a single wafer of non-defective chips in the first place. As their manufacturing process improves, the defect rate gets lower and lower and they wouldn't have enough defective CPUs to market to the more price-conscious consumers. Binning is much more likely to be used to sell lower-rated CPUs in the same general class.",
"Think of the half watermelon you buy at the shops, it was cut in half because part of it wasn't suitable to sell, this could be your i3/i5... if you ONLY sold whole melons you'd have to throw away all the imperfect fruit when there's people who are happy with a half or quarter melon. That premo perfectly shaped whole melon is your i9/i10, definitely the target but hard to grow a perfect melon every time. In conclusion, you can't trust a pig with watermelon."
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nn2hda | How do chameleons change colors on command? | Biology | explainlikeimfive | {
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"Chameleon skin has a superficial layer which contains pigments, and under the layer are cells with guanine crystals. Chameleons change color by changing the space between the guanine crystals, which changes the wavelength of light reflected off the crystals which changes the color of the skin."
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nn3792 | why is it possible to see something break through the sound barrier? | I’ve seen videos of jets creating this convo cloud effect when they go faster than the speed of sound. Since sound is not visible and it’s not matter, why can we see this effect? | Physics | explainlikeimfive | {
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"That cloud is water vapour coming out of the air and it isn’t directly related to the sound barrier at all, that cone can form when you’re not breaking the sound barrier or it might not form at all even if you are. They key to these vapour cones is flying very fast through moist air, this causes part of the air around the aircraft to decrease in pressure till it’s below the dew point and water held in the air comes out as a vapour which is the visible cloud, then the shockwave from different parts of the aircraft hits this air and forces all the water back creating the cone shape.",
"you're seeing the water vapor in the air condense and form what is essentially a miniature cloud around the airplane. You'll notice that this maneuver is often done over water/high humidity to enhance this effect, but it doesn't always happen. you need just the right conditions to see the perfect \"cone\" effect. the condensation forms as a result of the changes in air pressure caused by the plane pushing/squishing/compressing the air in front of itself. you can even see pics online of the light bending through the pressurized air, but the lower the altitude, the thicker the air so the harder it is to go faster vs. flying at high altitude in thinner air. It's like swimming in syrup vs. water. you can go fast in both, but one takes a lot more power to do in the thicker medium. that's why they try to make planes as slim and slick, as possible to reduce this resistance.",
"What you're seeing is called a vapor cone, and it is *not* inherently related to supersonic flight. All that's happening is that you have shock waves and expansion fans caused by the hard surfaces of the aircraft as it moves through the air; the shockwaves compress the air (causing the water in the air to condense into a visible cloud), and then the expansion fan rapidly returns the compressed air to ambient(ish) conditions (causing the water to evaporate again). It's generally a sign of a plane entering the *transonic* regime (e.g. Ma 0.7 to 0.9), but while it's an indication that a plane is certainly traveling fast, it's not necessarily evidence that they've actually hit Ma 1.0 or higher."
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nn3bxo | Fell in the Demon Core hole. Why would the two beryllium sphere make the core safe when an inch apart? Wouldn't plutonium constantly be emitting radiation regardless? | Physics | explainlikeimfive | {
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"> Wouldn't plutonium constantly be emitting radiation regardless? Yes, but most of that goes away from the plutonium core. Adding the beryllium reflects the neutrons back towards it, and that's what pushes the arrangement into supercriticality. The gap in the sphere is enough to let enough neutrons escape that the reaction isn't self-sustaining.",
"The Demon Core was a 6 kg sphere of Plutonium, so it was rather radioactive in the \"you'll have weird cancers in 30 years\" level, but not the \"instantly gonna kill you level\" Since it was just 6kg it was \"subcritical\" which means that while there are fission events going on there's roughly a constant amount of them, they're not increasing over time like a supercritical mass would. Beryllium is used as a neutron reflector, when some of the neutrons from the plutonium fission make it out of the sphere they hit the beryllium and get bounced back in. As long as the two beryllium shell halves had a gap they just resulted in the plutonium sphere having more fission reactions (and being more radioactive) but not steadily increasing in reactions over time. When the two parts of the beryllium shell closed, the excess neutrons could no longer escape and the plutonium became super critical. The amount of fission reactions going on climbed quickly making the whole thing *wayyyyy* more radioactive. Its hard to judge how quickly it climbed but you can do a quick thought experiment with low numbers to get an idea of how out of control it gets. If the shell is closed for 1 second, and they cause the number of events to double every 10 milliseconds, then in the 1 second that it takes the shell to be reopened the core would have gotten up to 10^30 x as radioactive. That goes from \"weird cancer eventually\" to \"you're already dead, your cells haven't figured it out yet\" real quick. You're always exposed to some level of radiation, plutonium and uranium and other things with long half lives are radioactive but not aggressively so. Things with short half lives like Cesium 137 decay significantly quicker and release proportionally more radiation per kg of material so a small amount of something like Polonium-210 with a half life of 136 days is more likely to kill you than a 5 kg hunk of uranium ore.",
"yes, the idea of the experiment is that the 2 semi spheres(that deflect neutrons) being apart is enough of a gap to keep the core below criticallity(the reaction becoming self sustaining the gap allows just enough neutrons to be \" lost\"). Being able to change this distance allows the test to happen at different stages as long as its not Zero. Natural radiation still occurs and the materials is very dangerous regardless but hopefully the experiments is happening in a controlled environment(and the half sphere assemblies are held better than just a half-aseed lever) and it exploits the fact that the neutrons being released naturally are \"lost\".",
"When a radioactive material such as plutonium undergoes fission, it splits apart and releases a neutron. If there is another atom of that radioactive material nearby, that neutron will cause it to undergo fission, wherein it splits and releases another neutron. So long as there are enough atoms of the fissile material nearby, this process will continue until all of the material has undergone fission. This is a nuclear chain reaction. The ability of a chain reaction to sustain itself, and the speed it progresses, depends on the density of the fissile material. That is, you need enough of it in a small enough space. This is known as critical mass. To prevent a nuclear chain reaction, then, you need to keep the amount of fissile material under the critical mass. This is where the one inch separation comes in. It is enough distance that a nuclear chain reaction doesn't happen: the plutonium atoms are too spread apart. The beryllium is there for a different reason. Beryllium is a neutron reflector. It basically takes any neutrons that would fling off away from the plutonium and reflect it back, increasing the reactivity."
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nn3ml7 | How come satellites orbit earth and our earth is also spinning while also orbiting the sun, but satellite dishes constantly face one direction? | Physics | explainlikeimfive | {
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"Satellite dishes that never move are pointing at geostationary satellites. These satellites orbit at the same speed that the earth spins and are above the equator so that they always stay above the same spot on earth. This is also why your satellite dishes always point (generally) south when you are in the northern hemisphere. The need to point toward a satellite that is orbiting \"below\" it at the equator.",
"There's a special orbit called [geostationary orbit]( URL_0 ) (GEO). Objects there orbit with the same angular speed as the Earth's surface as it rotates. From the ground the satellites always seem to be in the same place in the sky, so you can set up your dish to point at one and not have to move it.",
"Industry guy here. There are 3 typical satellite orbits LEO (Low Earth Orbit), MEO (Middle Earth Orbit) and Geostationary. LEO (which includes GPS and that Elon Musk ISP satellites) and MEO satellites have a periodic orbit. Geostationary satellites are located 23,000 miles away on the equatorial plane, and the velocity of the satellite matches the rotational speed of the earth. Geo sats will be orbiting in a designated orbital slot, i.e. 110 W latitude. To move a geo satellite east or west, the controller will just change its altitude. These orbital slots are assigned by an international body (I cant remember which). Also, there is a delay due to the distance to geostationary of about 1 second."
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nn3zi9 | Website names market. How can we buy and sell a piece of the internet? Who is the original owner, and how did they come to be in their possession in the first place? | Technology | explainlikeimfive | {
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"Basically, a non-profit called ICANN (The Internet Corporation for Assigned Names and Numbers) plays the central role. The origins go back as far as one researcher doing it. Then, the US Department of Commerce took on a role but almost everyone agreed it shouldn’t be under the control of one government. So, ICANN was set up and the Dept. of Commerce gradually gave up control. It’s not affiliated anymore. ICANN outsources the actual registration sales. So, different companies sprung up selling domain names. Over time, people made different proposals to expand the “top level domains” (like .com or .org) and we ended up with the early ones, national ones for each country, etc. There’s a Wikipedia page with which are which: URL_0 Eventually, ICANN decided the top-level domains could be anything and opened them up too. Nowadays, anyone who pays a (I think $200,000) fee can own their own TLD and limit it however they see fit. So, that’s why now, there’s URLs ending in things like like .cool or whatever."
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nn4z37 | Why is the death zone above 8000m still dangerous with supplemental oxygen? | Recently I have watched a number of documentaries about Mount Everest. It is always stressed how dangerous it is for the mountaineers to stay in the death zone above 8000m for too long, even if they use supplemental oxygen. Why does the use of oxygen not prevent altitude sickness and the risk of HACE and HAPE altogether? Should they not be fine for a long time, as long as they bring enough oxygen bottles? | Biology | explainlikeimfive | {
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"The main difference between being at sea level and being at high altitude, besides it being cold as fuck, is that the air is much lower pressure. This effectively means theres less oxygen available for breathing which is why tanks are required, but it also reduces the oxygen pressure in the blood, referred to as partial pressure. Yknow how divers who come up too fast get bad things happening? That's cos nitrogen suddenly decompresses in the blood and forms bubbles. It's not as bad with oxygen on Everest cos the difference in pressure is much smaller, but it's still bad. Instead of forming bubbles, the effective maximum amount of oxygen in the blood reduces. This means even with an oxygen tank you have less oxygen than you do without a tank at sea level, and it's sufficiently low that if you stay for too long your brain explodes.",
"Oxygen bottles are heavy and climbing Everest is a physically challenging thing to do even under the best conditions. Most people carry < 25 pounds of oxygen with them and that isn't enough to climb Everest if you're running the oxygen at sea level pressure. The pressure provided by most systems is equivalent to the air pressure at 5,000 - 6,000 meters, which is still low enough that pretty much everyone will develop some degree of altitude sickness (though obviously high enough that you don't outright die). Altitude sickness is made worse by physical exertion. So you basically have people who are exerting themselves harder than they ever have in their lives breathing bottled oxygen at a pressure low enough that they're suffering from mild to moderate altitude sickness. The combination of those two things means that some percentage of those people will develop severe altitude sickness. If it was practical to bring enough oxygen to run the system at higher pressures, IE, to pressurize it to sea level pressure, then it wouldn't be dangerous and you wouldn't get sick. But that's just not the case. Keep in mind you're not just going out and climbing Everest in a t-shirt and shorts. You have to carry everything you'll need to survive with you and that's a lot of weight to allocate among a large number of survival tools, of which a compressed oxygen system is just one.",
"I think it has to do with pressure. Your body basically breathes because of pressure. When you exhale. The pressure outside is greater than in your lungs, which causes an inrush of air. The opposite is true when inhaling. At higher altitudes there is lower pressure. This means that it is more difficult to draw air into the lungs and it gets forced out more easily.",
"The science isn't certain but it seems like some people just don't know when they don't get enough oxygen. Our primary breath regulation comes from CO2 levels in the blood. CO2 level raises, you feel out of breath, you start breathing faster. It's simple and it works because in normal conditions breathing works both oxygen and CO2 together, so it doesn't matter which one is monitored. However, in low pressure, blood CO2 levels are absolutely fine (even lower than usual) while oxygen levels drop. Our bodies are not accustomed to this and it takes time to adjust for the secondary oxygen-monitoring system. For some people, however, it seems the oxygen monitoring doesn't work good enough. They simply don't breathe enough to maintain proper oxygen levels because their system doesn't recognize the shortage of oxygen. Add to this the strenuous activities of climbing, extreme temperatures and the disaster is ready."
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nn4z5z | How can children sleep upright, folded like a pretzel, in a car seat with their chin on their chest and wake up feeling fine, whereas an adult would be crippled for days for sleeping lengthways on a sofa? | Biology | explainlikeimfive | {
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"Children are more flexible this allows them to sleep in weird positions and not be sore afterwards, same reason cats can sleep in weird places."
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nn57ob | What do restaurants/snack bars/food trucks etc. (nearly any type) do that makes their food taste better than food cooked at home? | Other | explainlikeimfive | {
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"I am a chef, let me tell.you we are not concerned about your health, we want you to have a delicious dining experience. We use a ridiculous amount of fat, salt, sugar, acid and alcohol in your food. Everybody knows about fat and salt, but especially the alcohol makes a massive difference. There are so many different alcoholic drinks that can enhance all kind of different foods, a good example would be Noilly Prat for fish dishes or a splash of sherry in your savoy cabbage. You'd never know it's in there, but it makes all the difference.",
"What mugnhut said. Restaurants literally get the better (prime) cuts of meats that never see a grocery store... then add more salt & fats than we do at home... Try adding twice the spices to your at home cooking - the difference is incredible.",
"Also Apart from salt, fat, and generous splashings of wine and liqour, we (most of us) are trained professionals. Why does your Barber cut your hair better than your aunt? Because they're trained. We really do need to start realizing this. Professional cooks are professionals",
"> Hello, i noticed that the food i eat out tastes nearly every time better than food i make at home. What do they put in (except for msg)? If you can't replicate the taste of a restaurant dish at home then be aware that the three secret ingredients are always (more) **salt, sugar and butter**. Edit: Oops, too late.",
"A shit ton of salt. Like, you'd fucking lose your mind if you saw someone put this much salt in your food.",
"One thing not mentioned is restaurants have more equipment than you have at home. Deep fryers, grills, griddles, broilers, etc. Cooking a burger on a griddle that's cooked 50 other burgers and then toasting the bun under a broiler can make a difference. Restaurants also have more ingredients at their disposal while at home we make due with what we have. The restaurant burger tastes better because the restaurant has all of the condiments, and the veggies, and the applewood smoked bacon, and the monterey jack cheese, and the special type of bun, and so on. At home we slap some American cheese on the burger and use a cheap bun with ketchup and call it a day.",
"Often fresher spices, as they go through so much it isn’t like that container of garlic powder that’s been in the cupboard for a year which has lost a lot of flavour. They may also be using fresh spices rather than preground which tend to taste better. And yeah, as everyone else pointed out, way more fat, salt and sugar than most people do at home.",
"Generally, a lot more butter, oil, salt or sugar than you would use at home. The food tastes better but is a lot unhealthier. Restaurants often get better quality ingredients than you would use at home as well.",
"Restaurants have a limited selection and well though out dishes. Restaurants have cooks Cooks are better at cooking than you are You can absolutely cook better at home than in a restaurant but it takes skill!",
"Food that I didn’t have to cook always tastes better, IMO. A sandwich I made, with stuff I know I like? Good, sure. A sandwich made by literally anyone else? Culinary masterpiece. Ambrosia.",
"Another contributor is heat. Home cooks worry about spatter, grease fires, spills, etc. A pro kitchen team turns everything to 11 and powers through service, clean up is for later. So sauteing food is actual sauteing. At home, the heat turned down, crowded pan you simply steam the food a lot of the time. Pro equipment is powerful, Home Depot appliances don't come close. (Quick story) I once walked into a diner I had, poked my head in the kitchen to say good morning and saw my head day cook calmly frying eggs, rolling sausage, crisping bacon while the flat top was propped up on bricks and the second cook was furiously scooping out burning grease. With burners lit! Someone the night before had forgot to clear the grease trap and coupled with the morning prep of sausage and then the start of service it overflowed under the flat top (where the flame is) and got going. Home cook is not going to cook like that!",
"I did a stage at a \\*star restaurant in Fontanbleau France. The brigade system, well thought out menu, proper ingredients and preparation and an Owner with an exceptional palate and eye. No dish left the pass without personal approval. We had a foie gras tasting menu with 5 different salts on the perimeter of a special plate with a broad rim. Eat around the plate he said. I had 6 outstanding tastes in one plate. The other thing is that alone you can't get the timing/veg/starch/sauce right and with brigade you can. Besides, they cook the dish many times/ over and /over. That''s what you pay for. As to satiation, go outside 5 minutes before plating. The food tastes way better even if that seems like crunch time.",
"I worked at a restaurant and tried replicating an exact dish at my house. After many attempts, I theorized it was actually the cooking medium. The oil in the fryer had cooked all the things, and it followed that some residual amount of those items was still in the oil. Like if they deep fried some chicken, then when they made the next thing the oil was subtly changed because of the chicken. Well, they cooked everything in this oil so after awhile it was not the same oil as what I had at home. But overall I don't think most of restaurant food is \\*better\\* than versions I cook at home. But it is so much easier that for complicated things I tend to just go restaurant and there aren't versions I make at home.",
"The short answer is \"trained proffessionals\". Anyone who is good at their job knows their skill has its roots in training and practice. Nomatter what the job is.",
"They use more butter, more sugar, and more salt than you do. A lot more. Now you're imagining the amount you think they use. Double whatever you're imagining and you're closer.",
"other than the obvious fat salt sugar.. freshness.. if your in the uk, try getting the ingredients for a fry up from a farmer... pay a little bit more money.. and compare it to a supermarket fry up.. you'll see and taste the difference.. also herbs.. fresh herbs.. if you make carrot coriander soup with dried herbs , and then fresh herbs.. it will be like eating 2 entirely different meals.",
"Heat! Your oven goes to a 1/3 or less of the temp that professional pizza ovens. Same goes for steak, the hotter the better.",
"Better cuts of meat and fresher vegetables (first pick), most ingredients don’t sit on the shelf for days/weeks like grocery stores...and butter.... so much butter",
"Sometimes it's all in your head. Going out perhaps with someone you like, sitting in a candlelit table and being attended to and paying a fortune for a meal makes the experience feel special, including the taste of food, though it may just be banal.",
"The more I read this the more upset I get lol why is a surgeon better at doing surgeries than I am? Why does my mechanic know how to fix my car properly? Why does that professional illustrator over there draw better than I do? Hmm..",
"It’s a psychological trick your mind does, and it has to do with not seeing the preparation stage/not doing it yourself. When making a dish or meal yourself, you see every step that is taking place so you know or imagine what the taste will be like. I’m doing so it’s kinda setting the taste of the dish up for failure. Not that it’s not going to taste good, just not as good as you have probably imagined it to be. This is nearly always subconsciously, end can’t really be controlled. When someone else prepares a dish or meal for you, you normally do not witness to creation/preparation stage. So the only thing you can base an imagined taste from is a previous meal or the smell. And it almost always beats that imagined taste because every meal will be slightly different."
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nn5qcq | Classification of psychedelics as a schedule 1 controlled substance with a "potential for abuse" | Other | explainlikeimfive | {
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"It was so that US federal law enforcement agencies could use allegations of drug abuse to target the anti-war and civil rights movements. Even if 'potential for abuse' were being measured by honest claimants(For excellent examples of dishonest claims of abuse see Dr. Donald Cameron, Dr. Robert Heath, Gil Kerlikowski, police unions, anybody who ever worked for Nixon) it still wouldn't be sensible to engage a prohibition backed by threat of criminal prosecution and imprisonment. It always has been, and always will be, about giving the government an excuse to disenfranchise people it hates."
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nn5y8i | National Debt | Economics | explainlikeimfive | {
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"Here's how it works in the US, and it's similar for most countries and states: The US Treasury issues debt instruments called bonds. A bond is a promise by the government to repay the cost of the bond, plus interest, at a later date (10, 20, or 30 years). People buy these bonds because they are an incredibly safe investment. The US government always honors its bonds, and is continuously paying back bond holders as their bonds become payable. The biggest single holder of US bonds is the US Social Security Administration, and the majority of bonds are owned by US citizens and US companies. International companies and foreign governments also invest in US bonds, because they are such stable investments. So a country's debt isn't really like personal debt at all."
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nn65wu | Is there a difference between sleeping late (say, 4 A.M.) and sleeping early (for example, 9 P.M.) if I sleep 8 hours every time? | Biology | explainlikeimfive | {
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"Consistency and light/noise/temp matter more than exact time of day If you are in a normal shared home apt you will have to contend with both daylight and noise from outside your bedroom. Both will fuck with your sleep if you always try to sleep just before dawn. But if you work the late shift and you have a quiet property and you buy blackout curtains and use HVAC to have a nice cool room? Then you can trick your body into thinking it’s night. Consistency is the big thing. Go to sleep the same time, sleep enough hours. Keep the schedule on your off days. Will make it much easier to keep that circadian rhythm. As an adult I figured this out. I used to stay up late and sleep in on weekends as a kid and always felt shitty for it. Now i sleep every night early as if i was going to work. On days off i wake up alert and refreshed and i have my whole day ahead of me!",
"Another poster was spot-on with their comment on light cycles. I can shed some more light on why light cycles matter. The amount of time you spend sleeping may be the same in both scenarios (going to bed early and going to bed late) but the quality of the sleep might be different. When you sleep, you go through several stages of sleep, each one with different levels of brain activity and different types of brain waves (basically different speeds of electric currents between your neurons - the cells in your brain). Each of these stages are important, especially those associated with deeper sleep, and especially REM (the last stage of the cycle). You cycle through these phases, going up and down from lighter to deeper sleep and back again, while you sleep. Eight hours is sleep is a guideline, because that is how long it takes for the average person to achieve the necessary number of REM cycles. Some people might need more and some people might need less to achieve the same number of cycles, which is one reason that some people do better on short sleep than others. The thing about light (whether it's natural outdoor light or blue light from computer screens and phones), is that it activates certain cells in your brain, which then produce certain chemicals that help you feel alert and stay awake. When it gets dark, and your brain stops getting activated to produce those chemicals, it instead produces other chemicals, which help you get sleepy. Even when you're asleep, your brain can produce these \"alert chemicals\" in response to light, and it can prevent you from properly cycling through the stages of sleep, and it can prevent you from entering the important, deep-sleep phases at all. So, although you slept eight hours, your sleep wasn't as good as it would have been in the dark. Even if you have blackout curtains and an eye mask to block the light when you sleep, you may have problems with your cycle of sleepiness/alertness, since you're not getting as many hours of light exposure once you wake as you would if you did most of your sleeping when it was dark outside and most of your waking when it was light.",
"I suffer from [delayed sleep phase disorder (DSPD)]( URL_0 ), so I've had the unfortunate opportunity to learn quite a bit about this. First, what people are saying about sleeping outside of your circadian rhythm is true. Your body has a sleep cycle it likes to adhere to, you can sleep outside of it, but it's almost always significantly worse in quality. However, what most of people are claiming to affect circadian rhythm is actually pretty shallow research. Certain things seem to be more important than others, like exposure to daylight; but the problem is that there isn't one overarching indicator. People just respond to too many different variables in too many different ways to have a completely successful measure on it. What causes your own circadian rhythm isn't always so simple. There are a lot of other environmental factors that can outweigh light cycles and such.",
"It can often be much harder to get good sleep if you are sleeping late because your body's natural rhythm is adjusted by the daylight. Even when you sleep the light leaking into your room will adjust your body's natural day and night cycle making you more tired earlier in the evening and making you more awake in the morning. So you get much better sleep if most of you sleep takes place at night when the sun is down. Similarly you should also avoid bright artificial lights in the evening.",
"There was just a study out that links depression with a person's [chronotype.]( URL_0 ) People who tend to wake up earlier have a lower risk of depression."
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nn68hw | How do people identify fossils? | How do they know there is some creature preserved inside the rock? Are fossils only formed inside a certain type of rock? | Biology | explainlikeimfive | {
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"Some kinds of rock are much more likely to contain fossils than others. Fossils form when dead biological material finds itself in a low oxygen environment and quickly gets covered in small sediment particles like sand, clay or other dead animals. The animal is prevented from fully decaying by the low oxygen, and gets trapped by the sediment. Over a very long time, that sediment builds up until it gets so heavy it compresses the layers below it into stone. The most common fossil rocks are shale (a flakey grey rock formed from clay layers in stagnant lakes that has many thin layers) and limestone (a rock made from the compressed dead calcium in animals - shell and bone fragments mostly - technically a limestone bed is made entirely of tiny fossils). Find one of those rocks and you're pretty likely to find a fossil, and once you've discovered one you're pretty likely to find a lot more. Another rock that commonly has fossils is sandstone, which as it sounds is a bunch of sand compressed together. Sandstone is a very common rock, and although it contains fossils more rarely, its ability to form on land means that sandstone is more likely to contain big land animal fossils like those of dinosaurs - the body is buried by a sandstorm, and subsequent sandstorms apply a bunch more sand, so a bunch more pressure and eventually the bottom layers become stone."
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nn754h | Why does the brain produce images of fractals when taking DMT? | Biology | explainlikeimfive | {
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"The existence of fractal-like visual hallucinations, such as those seen on psychedelic drugs, seems to implicate something about the structure of visual processing in the brain; namely, that the signals in an incoming visual image are isolated and amplified using an iterative feedback process. The suggestion is that signals come in, are first altered by activity in pre-processing structures of the brain, are then presented to the brain systems responsible for the visual component of conscious experience, and are then recycled back through the pre-processing structures in a loop. So you see something, your brain processes it, allows you to see it for a portion of that process, and then puts back it through the system again. This goes a long way towards explaining why we see fractals while hallucinating, because fractals naturally result from iterative processes."
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nn7iti | How do body builder’s bones support them when lifting high amounts of weight? | How do body builder’s bones support them when lifting high amounts of weight? | Biology | explainlikeimfive | {
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"Good question! Bones by default are actually porous on the inside and without physical training they will stay that way. However, when you do weight lifting and martial arts training your bones will adapt to the stress. The strain from lifting/striking will cause your bones to stress fracture and rebuild themselves. When the bone rebuilds itself it fills in all the pores causing the bone to be more solid and durable.",
"Well, human bones are remarkable strong. If I remember correctly, your patella alone is strong enough to support the weight of an entire elephant balancing on top. While they’re not super resistant to impact forces, like landing hard or being hit, whilst they’re fairly well built to handle other things like weight or compression. The easiest way to imagine it is like having a long metal rod, and a hammer. If you hit it in the middle (simulating a fall or impact) it bends, but you can hit it a hundred times on top (simulating lifting) with little to no effect",
"Working out muscles by lifting heavy weights also strengthens the bones because the weight and movement of the weight puts stress on the bone. Over time, the area of the bone experiencing stress gets built up with new bone material, making it stronger and resistant to more stress. If I am remembering my developmental biology and vertebrate anatomy correctly, mechanical stress on bone through exercise causes the bone cells to basically become a magnet for bone-building minerals to strengthen itself. So eating a healthy diet rich in magnesium, phosphorus, calcium and other nutrients is important for people who build muscle through heavy weight lifting exercises. Much in the same way intense weight training makes little tiny tears in muscle fibers that are repaired and reinforced by more muscle fibers, it also makes little tiny crinkles in bone structure that is repaired and reinforced by more bone cells. Also, most of your muscles usually do the job of stabilizing joints both while doing exercise and while just sitting around. Think of how many muscles wrap around your shoulder. This combination of muscles and joints is called the shoulder girdle. Exercising muscles that are important to stabilizing big joints like the shoulder makes it easier to handle the stress of heavy weights. Body builders and power lifters, though they have different goals for their sport, all want their body to stay healthy and strong. Strong stabilizing muscles makes it so other muscles don't have to work as hard to do a movement, and to keep the bone itself from taking too much stress. When a muscle contracts to lift a weight, it pulls on the bone at the muscles anchor points. This is mechanical stress. There are several different types of stress that can be applied to bone through exercise. First is compression stress, or the weight pressing down from end to end. The femur, or thigh bone, is remarkable in that its natural strength to resisting compressive stress is greater than concrete! Second is tension stress, or pulling a bone opposite directions from each end. Third is torsion, or twisting stress. Fourth is shear, or force acting in different directions against the bone. Too much stress on a bone before it is strong enough can cause stress fractures or compression injuries such as shin splints. If a muscle pulls too hard on its anchor point before the bone is strong enough to support it, the muscle or ligament can tear. Muscles are absolutely strong enough to tear themselves off bone but the human body works very hard to prevent that. There have been cases of people in life-or-death situations where they are so full of adrenaline that they tear muscles off their bones while say, holding on to a hang glider for dear life, or lifting a car off someone else."
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nn8e58 | How are chemicals in the brain made? | How does the brain create chemicals like dopamine, cortisol, serotonin, etc? And are these able to be created in a lab? Not sure if this goes under biology or chemistry sorry | Biology | explainlikeimfive | {
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"The same way every other chemical in the body is made, using tiny machines called enzymes, which guide chemical reactions in a way that is beneficial to the body. We probably could synthesise them in a lab, but it would be far easier to instead harvest it from living cells grown in the lab! Happy to extrapolate if you want me to."
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nn9rja | How is HTTPS any more secure than HTTP, if literally anyone can implement it? | If I can just go grab free certificates online and edit my own server configuration to serve a site over HTTPS, how does that add any security at all? I thought the security was because there was some vetting process that served as a barrier to entry. | Technology | explainlikeimfive | {
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"It secures the data between you and the webserver, so someone in the middle cannot see the contents of the page being sent or received (like when you're sending your credit card number). It also verifies that you are the site you say you are. It does not prevent someone from registering a site that's a common misspelling of a popular site and hoping people not notice.",
"> If I can just go grab free certificates Because only you will have the private keys to those certificates. Your public keys will be just that -- public, anyone can download them and view them, but those can't be used to impersonate you. If someone ever gets ahold of your private keys, then yes, they will be able to pretend to be you and HTTPS is useless. Keep your private keys safe! Never send them over an insecure connection like email, or store them unencrypted.",
"> If I can just go grab free certificates online and edit my own server configuration to serve a site over HTTPS, how does that add any security at all? I thought the security was because there was some vetting process that served as a barrier to entry. Yes there is still a vetting process. Go online and try to get a certificate for URL_0 , you will not be able to.",
"Just to add some additional info on top of what has already been said, bear in mind that even if you were able to acquire a legitimate certificate for URL_0 , people wouldn't be going to your server when they try to go to URL_0 . The DNS for URL_0 tells people which IP addresses to use in order to actually reach Google, and you wouldn't be listed on their DNS records. If you had physical access to someone's PC or their immediate network, you could override that DNS in various ways but you couldn't do that to every user on the internet. So there are several pieces here: - Public DNS to route people to the right servers. - Certificates issued for the domains by a trusted certificate authority that vets domain ownership. - A small set of trusted certificates authorities installed with common operating systems like Windows, macos, and Linux. - Private and public keys to ensure safe means to encrypt data across an open and untrustworthy internet."
],
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nnbcu0 | Why does bringing your knees to your chest (curling up in a ball) help you not feel sick when dealing with nausea? | And it gets worse as soon as you stand up or straighten your body? | Biology | explainlikeimfive | {
"a_id": [
"gztk7n9"
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"text": [
"Curling into a ball as an action dosent really change much but just lying down in a comfortable position reduces the natural sway of your body and makes you stationary which will help all of the fluids in your body to move less thus decrease Nausea Edit: if you try to stand straight with out moving you can tell the natural sway of the body. You are constantly activating small muscles to keep your self balanced kinda like balancing a pole on your hand but less extreme movements"
],
"score": [
10
],
"text_urls": [
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nnbse0 | Why are newspapers used to clean windows/glass surfaces? | Chemistry | explainlikeimfive | {
"a_id": [
"gztx9us",
"gztnl1v"
],
"text": [
"Newspaper, besides being found for free in the trash, is made from recycled fiber. Recycled fibers are highly processed, which breaks, or more precisely peels, pieces of the wood fiber off. This process increases the surface area of the fiber making it better for removing the small amount of liquid used to clean windows quickly.",
"But what about the ink? I bunch up newspaper by hand to light my wood stove, and my hands end up black. How does that produce clean glass? Good question OP."
],
"score": [
10,
5
],
"text_urls": [
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} | [
"url"
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|
nnc04b | What does this actually mean when people say private people tell you so little about themselves but you think you know a lot about them? | This might be stupid but I saw this thing where it says very private people have mastered the art of telling you little about themselves but doing it in such a way that you think you know a lot. Can someone give me an example? How can you tell someone little about yourself and they think they know you? lol Is that even possible? | Other | explainlikeimfive | {
"a_id": [
"gztwfgg",
"gzu9xsl"
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"text": [
"this can be done by mirroring someone’s sentiments. when you feel related to, you feel closer to someone, even if all they did was parrot and summarize what you’re telling them, without delving much into themselves. say you started telling some deep, emotional story about how you have trouble connecting with people because your parents never loved you, and on your 8th birthday they both forgot, and they shipped you off to your nan’s every chance they had. a private person can say just the smallest thing, like “yeah i also felt some distance from my parents, how do you think that upbringing has shaped your relationships now?” that gets the conversation back into your story immediately, and they master the art of always asking you questions to keep you talking. meanwhile, if you look at that statement about their parents, it was so vague that almost anyone could relate to it in some way. they gave no details. but because it’s a sentiment you were already giving out, you feel understood and that you guys were really connecting, when the only person giving specifics was you.",
"People tend to fill in the blanks. Say I'm talking to Steve and he mentions Bob is his new best friend. I hate Bob, but I keep my business to myself so I say \"oh? I don't talk to him much\" which is true. Steve assumes I only know of Bob or we've never cross paths. He is making an assumption and I don't feel the need to correct him because that's my business, and it doesn't really help Steve anyways. Or another bit is to give the impression you're very average. I have several medical issues, but often I'll just say \"I am just a sleepy person\" instead of explaining everything. Since just about everyone has a minor issue or two, no one thinks there could be more to the story. People think \"ah I know her medical history! That's a big deal\" but they really know nothing. People won't look for something if they don't know it's there."
],
"score": [
7,
5
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"text_urls": [
[],
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} | [
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nnc7ue | What is the worst case scenario for a pro fighter who gets hit with a low blow? | Can someone tell me what serious injuries can occur when you see someone get hit below the belt? I'm a guy and I've been hit there before a few times, even thrown up from the pain, but never with the force that a pro mma fighter, boxer, etc can hit with. Can a more knowledgeable person please tell me what the worse case scenario is male or female to severe trauma to the goods? Can you actually lose them? Thanks in advance! | Biology | explainlikeimfive | {
"a_id": [
"gztrvvy",
"gztrnrd"
],
"text": [
"Either a burst femoral artery or a testicular torsion. A burst femoral artery could kill you in seconds if you bleed out under your skin. A testicular torsion generally just leads to loss of the testicle if not remedied in time. Also a crushed testicle, crushed vesicles, or a permanently misaligned pelvis if you damage the pelvic junction. Src: asked a 10th Dan black belt",
"You could end up with testicular torsion or even a rupture just to name a couple of things that can endanger your life from a below the belt hit."
],
"score": [
5,
3
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"text_urls": [
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} | [
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nnd945 | Why are phone batteries measured in mAH and car batteries measured in kWH? Why aren't the measured the same? | Technology | explainlikeimfive | {
"a_id": [
"gztwju9",
"gzty28f",
"gztw945",
"gzu114h"
],
"text": [
"You calculate Wh by multiplying the voltage of the battery with the capacity in Ah. Phone batteries all have the same voltage, so you can just look at the (m)Ah rating. A 3000 mAh battery always has more energy than a 2500 mAh battery. EV batteries have different voltages, depending on the make and model, so the Ah rating alone doesn't tell you much. A 200 Ah/400 V battery contains more energy than a 250 Ah / 300 V battery.",
"One is milliamp-hours, and the other is kilowatt-hours. Milliamps are units of *current*, whereas kilowatts are units of *power*. Power is *current* times *voltage*. Since phone batteries have more-or-less constant voltage, it doesn't really matter much if you choose to measure output in terms of current or in terms of power -- you can convert from one to another simply by multiplying by the voltage of the battery. In fact, for phones, it's more natural to think in terms of \"current draw\" rather than \"power expended\". Otherwise, the units are chosen for convenience (phone batteries have much less capacity than car batteries, so this avoids having 0.0005 kWH phone battery or a 40,000,000 mWH car battery).",
"They're measuring storage capacity vs work capacity. If you're buying a car battery and you're paying attention to power, you might want to power other things, like extra lights or a fancy radio. In that case, you want a battery that can power these things. To do that, watts are the unit you care about. The amount of work a battery can do. But for phones, you care about how long it can keep your phone running. That's mAH. That's what that measures",
"I would suspect it relates a bit to how the batteries are used. For example, a phone battery or a AA battery would always provide about the same voltage. You charge them with a single voltage charger and so the amp-hours of a battery relate directly to the storage of the battery. Since the voltage doesn’t change, the amount of amps is the only thing that changes power (watts). On a car, you can slow charge it from your regular house outlet (110 volts), from a level 2 charger (220 volts) or from a super charger (400 volts). Because the voltage changes, charging the battery is not directly related to only the amperage of the charge. 15 amps on a 110 volt outlet is only half the power of 15 amps on a 220 volt charger. I suspect, In order to make it easier for people to understand, they use watts instead. 15 amps on 110 volts is 1.7 kW, and is the same as 7.5 amps on 220 volts. It’s easy to compare how quickly your car is charging based on the wattage because it’s a scale that works with any voltage. 5 kW will always charge faster than 1 kW no matter what voltage you are using. And if you are going to use kW as the unit for understanding power for charging, then it makes sense to rate the batteries in kWH. It’s a unit that can be understood in relation to charging it."
],
"score": [
19,
10,
3,
3
],
"text_urls": [
[],
[],
[],
[]
]
} | [
"url"
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"url"
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|
nndn4h | Why do most audio tape formats have two "sides" when each one is simply one-half of the same physical side? Wouldn't it accomplish the same sound quality and recording length, and be more convenient, to just record across the entire tape width at half the "double-sided" speed? | Technology | explainlikeimfive | {
"a_id": [
"gzu0f0d"
],
"text": [
"Because then you couldn't listen to an album continuously. You would have to rewind at the end of the album like a VHS tape. (People put music on repeat much more often than they do movies.) Maybe also a holdover from vinyl having two sides, so it was sort-of expected."
],
"score": [
11
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
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|
nne2c5 | why is baking soda so good at cleaning so many different things? Why is it so versatile? | Chemistry | explainlikeimfive | {
"a_id": [
"gzu6or0",
"gzv0kx7"
],
"text": [
"Basically (hah!) it's a fine abrasive so it acts as a scouring powder. It has never really worked for me because it relies on \"elbow grease\" meaning scrubbing, which I happen to be bad at.",
"In addition to other answers, most food stains and sweat and similar are slightly acidic. Baking soda is slightly basic and so it'll react with it to form water which is easier to wipe away and will probably neutralise some of the smells and stains."
],
"score": [
7,
3
],
"text_urls": [
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} | [
"url"
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|
nnefom | why does an MRI make so many sounds and why can’t they be quieter? Are the sounds test-specific? | Technology | explainlikeimfive | {
"a_id": [
"gzu6uux"
],
"text": [
"The MRI machine uses a combination of a strong magnet, radio transmitter and receiver. When the sequences are performed, electric current is sent through a coiled wire - an electromagnet. The switching of the currents causes the coils to expand making loud clicking sounds. Additionally, there are multiple different sized/powered magnets that make different sounds. All of the magnetic coils are very large in size, using a large amount of electricity, which is why the sound is so loud."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
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|
nnj1yp | How does increased CO2 levels in surrounding air lead to decreased cognitive function of the brain even at 600 ppm? | Biology | explainlikeimfive | {
"a_id": [
"gzurcn3",
"gzusyyw"
],
"text": [
"Gas diffusion across the cells of the lung depends on concentration differences. The smaller the differences the less gas is exchanged. So the more carbon dioxide in the air you breathe the less is removed from the blood. Effectively, the level of co2 in the blood increases. That's not great, because the more co2 in the blood, the less oxygen binds to haemoglobin. This means less oxygen getting to the brain, and the less oxygen in the brain the worse it is at braining, because oxygen is needed for ATP production (conversion of glucose to usable energy) and ATP is needed to restore action potential after a nerve fires (it's used by the sodium potassium pump). So the brain takes longer to reset after a signal is sent.",
"If you've ever tended to a BBQ fire, you that having a good draft is crucial: not only to get oxygen to the flames, but also to let the smoke get away and so make room for oxygen to flow in. In you blood, it's the same problem: The lungs not only have to get fresh oxygen into the blood, they also have to get the spent air (the CO2) out of the blood. The latter is the harder part, because a CO2 molecule sticks *much* better to a red blood cell than an oxygen molecule. Imagine all the oxygen and CO2 molecules in your breathing air trying to get a ride with the red blood cells. Unfortunately, the CO2 molecules are very *very* much better at pushing and shoving their way in than the oxygen molecules: Unless there are thousands of times as many oxygen molecules than CO2 molecules, none of the oxygen will ever manage to get into a red blood cell. So, if there's too much CO2 around, your brain won't get enough oxygen and you feel dizzy."
],
"score": [
9,
3
],
"text_urls": [
[],
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} | [
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|
nnouos | Why does tensing the jaw make your ears ring? | Biology | explainlikeimfive | {
"a_id": [
"gzvlb3e"
],
"text": [
"When you tense your jaw muscles, you are putting strain on the spot where your jawbone meets your skull bone (temporomandibular joint). This joint is physically very close to the hearing mechanism. All sound is vibration, and in this case, your skull is vibrating a little bit from the static / isometric (muscles engaged but nothing moving) stress it's being subjected to by your jaw muscles."
],
"score": [
18
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
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|
nnpboc | why web frameworks change or die overtime ? | Technology | explainlikeimfive | {
"a_id": [
"gzvq1q9"
],
"text": [
"Web frameworks are like cleaning devices. In the past, everyone used a broom to clean. When the vacuum cleaner was invented, it sped up cleaning and made it easier. Newer web frameworks have more modern standards and are easier to code in (usually). Old frameworks die because who wants to use a broom when you could use a vacuum cleaner?"
],
"score": [
3
],
"text_urls": [
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} | [
"url"
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"url"
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