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7ekxr0 | What's the difference from an Ethernet Switch and the extra Ethernet Ports on the back of my router? | I know what a switch does, and why its useful, but on the back of my router/modem provided by my ISP, there are other Ethernet ports that I can hook up my computers to for wired connection. Is that a "built-in" switch? Also, do most home networks not use switches? when does a switch become necessary? when 5+ devices are on ethernet? 10+ devices? | Technology | explainlikeimfive | {
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"Exactly, it's a built-in switch. Your home router/modem is actually a router, a modem, and a 4-port or whatever switch in a single unit. Most people don't have that many things that need or benefit from a wired connection nowadays, with wifi being so popular. So those 4 ports are usually sufficient for most people. Those that need more ports would have a switch. A switch is simply necessary when you have more things to plug in than you do ports."
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7elkxb | What stops our body from defecating when we pass gas? How does flatuce exit below a solid? | Biology | explainlikeimfive | {
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"If you can imagine how air could leak out of a balloon filled with rocks without the rocks falling out, that's pretty much how it works with your butt. And if the solid isn't \"solid\" enough... well, sometimes your body can't stop both happening at the same time."
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7emc0f | How can I get electroshocked while building a computer, even when it's all turned off? | Technology | explainlikeimfive | {
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"Capacitors are things that hold a charge after the computer is turned off. Capacitors slowly lose their charge, but it takes a while. Some capacitors can be deadly."
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7emfc7 | I've noticed that women I know who have 1 C-Section seem to have C-Sections for every child thereafter. Can someone explain to me 1) Is this a necessity, or just coincidental in the particular women I've known, and 2) Why would that be necessary? | I recently gave birth to a wonderfully healthy, beautiful, perfect baby girl. I had been planning on a vaginal delivery, but when my water broke my placenta abrupted, I began hemorrhaging excessively, and we were rushed into the O.R. for an emergency c-section. My boyfriend mentioned that any further babies will be c-sections too (he's all excited that my lady parts have remained unstretched...). I realized that I do notice this to frequently be the case, but can't really reason out why one c-section would require them from then on. Any information would be appreciated. ☺ | Other | explainlikeimfive | {
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"The answer depends on your health history. The reason why other women you know had c sections may be different then for you. From what you are saying your c-section was an emergency section. An important note is what kind of incision was made. Typically scheduled c-sections where it isn’t an emergency are done with what are called low transverse incisions. These incisions are good bc the uterus is usually able to heal pretty well. However in an emergency sometimes there isn’t time and the baby needs to come out quickly. In this case a vertical incision is made. Now why does this matter? A vertical incision is more likely to result in uterine rupture. So if you had a second baby and went into labor the uterus contracts while having a baby inside stretching it. The place on the uterus where the vertical incision is can tear and the baby will enter the abdomen where it will most likely die. For this reason patients who have had a vertical incision c-section will have repeat sections from then on. With transverse incisions the chance for a vaginal birth after cesarean (VBAC) can be tried. However once again bc the uterus is scarred there is a greater chance of rupture and therefore a higher probability of a repeat section. However statistically many VBACs go well and some patients have multiple babies after a c section. There are many other reasons for c-sections. Babies presenting as breech where the feet are down instead of the head. In this case One can attempt to move the baby into the proper position but if this fails it will most likely result in a section. A baby may also be face up in the pelvis (occiput posterior) and gets caught on the pubic bone. Sometimes in this case If the baby doesn’t rotate a c-section may be necessary. Other indications would be twins that are mono mono. So they share the same placenta. A vaginal birth could be dangerous bc once baby A is out baby B is not receiving blood and oxygen so a c-section will have a better outcome. Sections may also be indicated depending on the babies fetal heart monitoring strip. This is basically a way that we can see how the baby is handling the stress of labor and specifically is related to acid-base status or hypoxemia. If vaginal delivery isn’t happening and the baby is doing bad then a c section may be needed. To sum it up. A c-section may be a necessity if you have certain risk factors. If not then a VBAC is completely reasonable. It’s always nice to have a vaginal birth as it’s easier on the Mom and baby. However, c-sections in some cases are a medical necessity but having one does not always mean you will have another."
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7emj62 | why do nuclear detonations rest in the infamous “mushroom cloud”? | Physics | explainlikeimfive | {
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"All really big explosions will make a mushroom cloud. The explosion super-heats a volume of air. That air then rises, and as it rises sucks in cooler air from around and below it to fill the void. The air continues to rise, forming the \"stalk\" of the mudroom, until it starts to cool and spread out at higher altitude and forms the \"cap.\" All that rushing air pulls in lots of dust, smoke, and pulverized debris along with it, creating a big mushroom-shaped cloud.",
"A bomb that big creates an enormous amount of hot air when it goes off. Hot air rises, so now you have a huge mass of super hot air where the bomb used to be. That mass rises and air from the surrounding area rushes in to replace it (wind). The mass also has a lot of dirt and stuff in it, and that gets carried upwards by the wind."
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7emkfz | Why do beer bottles fizz out of the bottle when someone smacks the top with another beer ? | Chemistry | explainlikeimfive | {
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"All beer contains a certain amount of fizziness. If you pour the beer out of the bottle this fizziness is released as bubbles of gas that create the foam that forms on top of the beer. If you leave the beer in the bottle it still contains all that fizzy potential (it'll feel a lot fizzier on your tongue than if you've poured it into a glass). When you give that bottle a swift hard hit on top it will rapidly agitate that fizzy gas in the beer and that gas will escape quickly in the only place it can, the hole at the top. This is what causes the beer to overflow out of the bottle quickly."
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7en65q | How do (usually paid for) fake social media likes, favorites, and followers actually happen? | I often see advertisements for tools to rapidly gain likes, followers, plays (on soundcloud), or additional methods of clout on various social media sites. What methods do these programs use to make this happen? | Technology | explainlikeimfive | {
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"It's actually generally not controlled by a computer program, but sadly but people in countries with low wages, typically like Indonesia or sometimes the Philippines. Companies hire people and pay them very little to click \"like\" or \"follow\" or whatever on thousands of people's page/groups/companies/etc. that have paid for the likes, but as this takes very little time the workers can often follow hundreds or thousands of new links a day. Keep in mind that they will have little or zero engagement in the thing they've liked, which often hurts people on Facebook more than it actually helps because of how the programming is set up."
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7enair | Why do we feel less need to pee when we are walking? | I was talking to my mother on the telephone. And the conversation was too damn good. We didn't talk like that in months. Then, the urge to pee begun and it was too damn strong. I started walking around the room and realized it was easier to hold when walking. Why? | Biology | explainlikeimfive | {
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"The urge to pee is something which can be suppressed by the sympathetic (fight or flight) nervous system activity, or becomes more obvious when parasympathetic (rest and digest) nervous system activity predominates. Physical activity shifts the balance towards the sympathetic nervous system."
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7enbcj | How are people so influenced by music, what influences people’s tastes, and what separates good from bad music? | Other | explainlikeimfive | {
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"So we know that music has a psychological effect on humans, especially mood. The \"why\" is pretty complicated and psychologists don't have great answers because music is conflated with identity, social groups, expectations and other stuff that's difficult to isolate. We do know that certain sounds and lyrics tend to induce certain moods. This is why background music is important to film and games. Music is not inherently good or bad. There is no objective measure of good or bad, only concensus. Most music has a goal. Did you feel good listening to that song? Did that song make you feel better after a breakup? Did that song make the murder scene scarier? If yes, it's good to you. If not, it's bad to you. I might totally disagree. The definition of good and bad music is really people trying to argue, \"My opinions are more valid than yours.\" Musical taste is one aspect of the social pecking order and identity. Taste in music is a combination of personal preference and social signalling. There is perception that redneck hicks love country music. There is a perception that angsty teenagers love emo punk. We utilize those perceptions to sell ourselves or impose an image on other people. This can effect how you genuinely perceive music, because for whatever reason, we use musical taste to define identity. In this way, musical taste is no different than fashion, preference in cars, skin color or political party. Yes, it's there to keep us warm, get us to point A, keep out microbes, or run the country, but they also define us, whether we like it or not."
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7end7k | Why is the Internet governed the way it is? .... How did it become controlled by a handful of companies? And also isn’t there a way to get internet without these big companies and their contracts? | Technology | explainlikeimfive | {
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"Its more or less always been that way because the Physical infrastructure needed for the internet is very expensive. This causes something called a natural monopoly where very few companies can pay the needed cost to start up an ISP. Natural monopolies arent even rare and usually aren't too much of a problem due to large amounts of government oversight. Water, Gas, and Electric companies are all examples of natural monopolies and thanks to constant government oversight most people dont think about them as a monopoly. Alternatives to the current set up for the internet all have problems. The internet is very large, and decentralized internet isn't quite practical on a global scale(yet).",
"This fully depends on where you are, and who paid or the infrastructure to get internet to your house. Different nations have different rules and histories with internet infrastructure, but if you are in the states and only one company paid to put down wires to your area then you are sorta fucked. And infrastructure is expensive, thats why its only a few companies, who were mostly telephone companies before that (because they had the capital and existing infrastructure to be viable).",
"Imagine the internet like a tree. To go from one leaf to another, you need to travel up the branch and join with other smaller branches until you reach the trunk, then reverse the process to get to the other leaf. The internet is physically built this way, a bunch of cables connecting Tier 1 ISPs to Tier 2 ISPs to Tier 3 ISPs all the way to the end consumer. If you wanted to become a Tier 1 ISP, you would need to lay millions of miles of cables and make deals with the other Tier 1 ISPs to access their data. Even if you built your own internet-capable satellites like facebook or google, you would still need to negotiate with the Tier 1 ISPs to access the rest of the internet outside of your satellite network."
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7engdb | I'm told that if you delete data from a computer, it isn't *actually* gone, and is recoverable - so if the freed up memory can be used for new data, how is it possible given storage capacity limits? | Technology | explainlikeimfive | {
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"Imagine it like a whiteboard. You write information on it, and anything you want to keep you write next to it 'do not delete'. When you finally dont need this data anymore you just remove the 'do not delete' message. This doesnt mean the information you wrote on the board is gone, it just means that when you need to write something new you can wipe it and write the new thing over it. When people say it is recoverable what happens is they put the 'do not delete' message back and the computer can read it again. To ensure that data is really gone there are programmes that write junk messages over the data several times so that even if you put the 'do not delete' message back, the original contents arent there, or are badly over written.",
"Think of your file system as a book. To make locating and organizing the files faster and more efficient, every file is listed in the table of contents. This way the computer only needs to look at the table to locate the file rather than flipping through the pages. This also means that all file management is handled by that table of contents. Moving a file is just changing it's place in the table, the actual pages it's stored on don't change. Deleting a file just removes it from the table of contents, the information on the pages is still there, but the table says they're blank. Since the computer relies on the table to tell it the state of the pages, it assumes those pages are empty and will over write them. you can use certain programs to ignore the table of contents and go directly to pages marked empty and read whatever data is still there, this is how the data is recoverable, however this only works when the computer hasn't over written the data.",
"Data can only be recovered for so long after something is deleted, and its very possible to delete something permanently off a drive. Basically when you \"delete\" something it just pretend that the data isnt there and will write new data over it in the future. Once data is written over it the original data is gone forever and can never be recovered. Until the data is written over though it is treated as empty data, but if you really tried to read that portion of the drive it would pull up whatever was saved there."
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7enm9z | If the moon's orbit around Earth is 27 days, what does that means for how often the moon is visible to me, a person on earth? | As in, how many days is it visible or not visible to someone? I'm sorry if this doesn't make much sense... | Physics | explainlikeimfive | {
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"Save for when it is full lunar eclipse it will be \"visible\" every single day due to the earth spinning on its axis. It will just sometimes be overhead during the daytime making it hard to see."
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7enrdx | How do "text x to xxxxx" numbers work? | Technology | explainlikeimfive | {
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"at least in the US, these are called shortcodes, and you buy them from [this company]( URL_0 ) which has agreements with all the telecoms to support these numbers. as to 'how do they work,' well it's no different than a normal phone number as far as how you interact with the phone network is concerned as the user/provider of a shortcode. they are really expensive to acquire compared to normal phone numbers and fun fact: every single one of them supports texting STOP to the number to opt out of receiving any more texts from it. supporting this is a requirement of the contract you sign as a company to acquire one of these numbers (or at least was when i looked into it for the company i worked for). source: worked at a company where we briefly looked into buying a shortcode to use when sending text message based notifications to our customers, and decided it was not worth it at all.",
"Could be completely wrong here but I am quite sure it works with partnership with a cell company. The cell company can make any numbers they wanted to and the show is partnered up with them to split up the profits from the phone calls and text messages like 60-40 or something which is still a stupid amount of money. It basically forwards < contents of a text message > to a shortened phone number that moves to a program, that takes the contents that text message and tallies it up with whatever contestant it is. For Example: `if < contents of text message > is \"resist\" then` ` votes_of_person gets incremented by 1`"
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7enwkm | Why is the most accurate and precise way to read a babies’ temperature is through the rectum? | My wife and I our having our first child this week. One thing that we have yet to buy is a thermometer for the baby. As the title says, I am very curious as to why a rectal temperature is the most accurate. There are thermometers in the market that roll over the forehead. Obviously a forehead reading would be much more convenient but why would it not be as accurate? Thanks in advance for all the comments! Edit: clarifying the question. | Biology | explainlikeimfive | {
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"Taking your temperature rectally is most accurate for all of us, not just babies. It gives you a much better impression of actual core temperature vs other methods that are a less accurate. Taking your temperature via your mouth/forehead/arm-pit, it is all not really internal to your body, is further away from your core, and is more influenceable by outside factors. If you just drank something cold though (or something hot) a mouth thermometer could give a false reading. The thing with babies is though they obviously don't have much of an immune system yet. And they are so young and small that they cannot handle as much as a regular adult can. They also cannot regulate their body temperature as well as an adult, so their temperature can spike more rapidly, which can lead to seizures. And often when they do get a fever, especially when they are really young, doctors want to treat them ASAP. So it can be more important to get a more accurate reading for them vs you as an adult who has the immune system to handle whatever is making you spike that fever.",
"Off topic, not answer, breaks ELI5 rules and will get deleted, but need to be said. Congratulations!",
"Watch how the nurses do it in the hospital. I'm guessing they'll use the infra-red ones that go in ears. Is it the most accurate? No. Is it accurate enough? Absolutely, and it's *way* more convenient.",
"Because a baby can't be told to keep an oral thermometer in position long enough to get a proper reading. The other end may end up being just as upsetting to the baby as trying to hold a glass tube under its tongue, but it's vastly more successful as well."
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7enyqf | Why does ones mouth water a lot right after smoking weed? Is it the psychological aspects, or just the smoke in your lungs? | Biology | explainlikeimfive | {
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"What? I've tried that shit a few times and my mouth goes completely dry for hours."
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7enzmv | what exactly is this committee announcement trying to say? | URL_0 I'm having kind of a hard time unpacking exactly what their message is, since it seems contradictory. Are they calling Net Neutrality "heavy handed" but also committing to it's permanent existence? I need some help here. | Other | explainlikeimfive | {
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"So I'm going to answer in two parts. Part 1 is why they called this \"heavy handed.\" Part 2 is speculation on what they mean by committing to net neutrality's permanent existence. Heavy handed refers to the fact that the FCC instituted net neutrality through rule-making procedures. The FCC is an executive agency, which means that it can't create new laws, only Congress can do that. But, the FCC has authority to interpret existing laws through reasonable rules. That's how we got net neutrality. the FCC interpreted a 100 year old law in a new way. Conservatives tend not to like this process because, even though it's legal, it seems odd to say that a law which never even imagined the internet is being used to regulate it. So, this statement is saying it was heavy-handed to try to create regulations that way. Regulations should only be created through Congress passing new laws. Now, onto the second part. This can be interpreted one of two ways. The simplest way is that the committee would support net neutrality if it was passed through legislation. The other way (and this is the speculation part) relies on a past history of Republican legislators giving a different meaning to \"net neutrality.\" In the past, Republicans have referred to \"a free and open internet\" as one being free from government regulation. In that way, the internet is kept neutral from government interference. But, this is the exact opposite of net neutrality as we commonly use it. We common use it to mean government regulation to force companies to remain neutral. So, the second part of this statement could either mean (1) we'll support regulation if congress does it; or (2) we'll support laws to prevent the government from interfering and call it REAL net neutrality",
"The bottom line is that they (the key Republicans in Congress for tech issues) support Pai's plan to kill net neutrality. The \"heavy-handed regulation\" refers to the net neutrality rules put in place under Obama. The twist is that they would actually like to pass legislation on this issue. They realize that a future Democratic president could just reinstate net neutrality rules, so this issue will just swing back and forth forever. It's better to lock a decision into place in legislation that can't be undone so easily. Right now, Republicans have the upper hand, so they would like to pass the legislation now. They would probably be willing to compromise with Democrats to put in place some minimal \"net neutrality\" rules. So, for example, maybe ISPs would be barred from blocking or selectively throttling websites, but pay-for-priority fast lanes would be ok. The question is whether Democrats will want to come to the table to compromise now or try to get a better deal when they're back in power."
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7eo292 | How do we know the Zodiac Killer’s cypher isn’t just complete BS that he made up? | I mean how do we know it’s an actual code or cypher that translates into something? How can we say that it does in fact contain information key to solving the crime he committed? Are we assuming, based on serial killer psychology, that these people like to brag and taunt the authorities? Thats not unheard of but is it true in this instance. | Other | explainlikeimfive | {
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"We dont, one of the driving theories is that it is total BS to throw off the police. He sent other stuff to the police that was meant to say something, so its really just an assumption that the cryptographs mean something too. Its pretty much impossible to say for sure",
"That's basically it, we believe that the Cypher is solvable because serial killers who send notes want to send a message. If he just scribbles jibberish and mails it in, he might get a giggle at attempts to solve it, but it doesn't get a message. If the Cypher can be solved, then he knows the reason they haven't found his message is because he outsmarted them. Out of the Cypher letters, only one of them was ever solved.",
"That is a theory. The fact that a cipher made by a lone whack job remains unsolved after nearly 50 years despite massive advancements in both computers and cryptography is pretty strong evidence for that theory. But it is a boring theory, so you are unlikely to hear the next time basic cable decides to recycle the story."
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7eo7nm | Credit Unions vs. regular banks | Why is it that when I deposit a check into my account at a local credit union that the money goes in right away but if my mom deposits a check into her account at BMO Harris it takes 2 days or it goes in the next day? | Economics | explainlikeimfive | {
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"A bank is business where people put money for protection. The bank protects the money and allows you to conveniently access it via checks or debits. While your money is in the account the bank can also do things with it like loan it out to people or businesses or even invest it. You are paid for the use of your money in the form in interest. Banks are owned by shareholders who own the bank's stock. The banks primary purpose is to make money for the shareholders. Owning a bank means owning stock of the bank and being entitled to some of the profits of the bank. A credit union is a financial co-op where people store their money for protection. In this manner it operates similar to a bank. The credit union provides convenient ways to access money like checks or debits. The credit union is also able to use the money of depositors for loans and investment but the primary purpose of the credit union isnt really to make money. Instead, you could argue the primary purpose of the credit union is to financially support its members. The interesting difference is who the owners are. In a credit union, the depositors are the owners. The credit union doesnt have stock because the money in the accounts is effectively the shares of ownership.",
"can only speak for US banking regulations, but if i remember correctly they have up to 3 days to 'float' a check meaning they don't release the funds upon depositing it, allowing them to temporarily do things with the money that technically isn't theirs. large banks usually have investment arms and sources of money like this (another one would be interest on loans) are often used for investment purposes (essentially, use money from recently cashed checks to buy some stock, sell it a day or two later likely realizing a profit thanks to the money that 'wasn't theirs' before they are legally required to credit the customer's account). credit unions are organized for the interests of their members, not the bank as its own business, so there is a lot less incentive to do things like this (they may not also have as much capital as a large bank to justify doing these kind of things vs. the return on investment)."
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7eobm5 | If/do our bodies swell in certain areas to protect a hurt or damaged area. Why do we use things like ice packs to reduce swelling of that area? | Biology | explainlikeimfive | {
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"Because we have the option of taking it easy for a few days to let it heal. Inflammation is kind of like a natural ace bandage. It immobilizes the joint and lets you know with pain if your movements are making it worse. This was really valuable if you had to keep up with your tribe as it migrated across the steppe. Today it is a lot easier to put your feet up for a few days.",
"Because the benefits to our comfort are immediately obvious to us but the repercussions of modifying the natural history of an injury are not as obvious or well understood.",
"Swelling and pain are body's natural functions to protect the injured area by minimising the mobility that can aggravate the damage. Ice packs are used to reduce the swelling and thus numbs the pain. Basically you don't want your body's natural function to let you know by making you suffer that you need to rest that injured part, because you already know."
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7eoipa | What's special about CO2 that we add it to water/soda and not other gasses? Why not use compressed air or another gas? | Chemistry | explainlikeimfive | {
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"Originally beverages were carbonate via fermentation, which produces CO2 as the yeast or bacteria eat some of the sugars. Some beverages still are done this way, such as beer. CO2 is still used because it's cheap and adds the acidic flavour. Some of the CO2 in the drink forms carbonic acid. Air couldn't be used because it contains oxygen, which will allow for the beverage to spoil. Other gases can be used though. Guinness beer for example uses a mix of CO2 and nitrogen, giving it a more foamy head. In general, for a gas to be used for \"carbonation\", it would need to: * not cause the food to spoil (which is pretty much just oxygen) * not cause some sort of undesirable chemical reaction with the beverage. CO2 will make some carbonic acid which is fine, but others may make more of worse chemicals. * not have any negative odour or taste. You wouldn't want sulfur based gases that smell like rotten eggs. * they would obviously need to readily dissolve in water. Helium for example would probably work fine, if you could actually get it to dissolve as well as CO2. * I suppose I should add on not be flammable would be nice too, as even if methane (aka natural gas) or hydrogen could work, they would also be a little dangerous. * Also in the extreme, you wouldn't want it being poisonous. We add a little chlorine to water to kill bacteria, but you wouldn't want a rupture of chlorine coming out of a beverage or it will kill you. Lots of other toxic gases you wouldn't want in there. * Again in the extreme end, you wouldn't want the gas to be a environmental issue. Something like SF6 may very well work, but you wouldn't exactly want a lot of that getting into the atmosphere. A lot of gases wouldn't work for one of these reasons or another. I'm sure there's some other gas out there other than CO2 and to a lesser extent N2, they however most likely wouldn't be as cheap and easy.",
"CO2 really is special! Most gases just dissolve in water, drifting around among the water molecules and not doing much. But CO2 *reacts* with water! * CO2 + H2O -- > CO3(--) + 2 H(+) This forms carbonate (CO3) ions, and also a lot of free hydrogen ions (H+). Water with extra H+ ions is an *acid*: adding CO2 makes the water more acidic, which is why carbonated water tastes sour. This reaction also gets rid of the dissolved CO2 in the water, allowing *even more* CO2 to dissolve into the water, and get reacted, and so on, until eventually a balance is reached. The net result is that you can put about [25-50]( URL_0 ) times as much CO2 into water as you can an ordinary gas! If you put the gas in at high pressure, it will bubble out when you open the container, and that means that adding CO2 gives a much bubblier drink thank other gases. There are a few other gases that react with water like this (for example hydrogen chloride), and they also have very high solubilities, but they'll kill you if you drink them. (*) This reaction is simplified, but good enough for ELI5.",
"Mostly it's really cheap and soluble. Early sodas got their CO2 from bacteria or yeast, and some artisan sodas like natural sarsaparilla still do.",
"CO2 is highly soluble in water. From memory, a given volume of water at 25 C can dissolve around 400 times its own volume of CO2. Most of the other common, non toxic gases are far less soluble. Nitrogen, oxygen, argon and other commonly used gases have very poor solubility in water. You may want to have a look at these solubilities: URL_0"
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7eoiqy | If pre-2015 internet wasn't a hellscape, why would it become one following the removal of the 2015 rules? | Other | explainlikeimfive | {
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"Thats like saying there weren’t many gas attacks in the history of war before the geneva convention, why would rolling back the geneva convention cause people to use more chemical weapons? Telecommunication companies have the capacity and drive to abuse a lack of net neutrality that they didn’t manage to implement before 2015.",
"Because the technology was in it's infancy in 2014. Deep packet inspection was just being pioneered by the Chinese. Once it became possible to record your every website click the first ones to do it were the NSA. But now that shit's commercial and cheap enough and intelligent enough to make life *really suck* if you don't buy the 150$/mo super bundle from your only internet provider. For a limited time free Vimeo videos for a month! We're so sure you'll like Vimeo videos we'll offer you your money back if you don't like it. *will require canceling your entire package and never being online again"
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7eoqyp | Why ejaculation feels better the longer you last? | Biology | explainlikeimfive | {
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"Because your brain has more time to \"set things in place\" - orgasms are partly chemical and partly electrical.",
"Well I think this is more of a mental thing. Usually when we last longer that must mean that we pleasured our partner better giving us that initial satisfaction followed by the second satisfaction (finishing) thus, a double reinforcement. Unless if your talking about masturbat ion thennnn... I got nothing."
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7eora3 | Why does our tongue 'get burnt' by very sour food | Food, like, say, Warheads Hard Candies (Which are my favorites, hence why this question comes to mind.) | Biology | explainlikeimfive | {
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"chemical burns. the stuff that makes those foods sour is typically a high concentration of a weak acid, like citric acid."
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7ep6x2 | I thought the internet was a series of interconnected routers and computers that communicate however they want. How does one institution in one state control this communication even for people in other parts of the world? | see title | Technology | explainlikeimfive | {
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"The internet is mostly run by companies who own infrastructure (like wires and shit). The institution you're talking about (assuming the FCC) gets to decide what these types of companies are allowed to do. Right now they are FORCED by the FCC to treat all traffic equally. We are worried that the FCC will change their mind and no longer force these companies to do this and thus the big greedy companies will do more greedy stuff. The reason it effects the world is because the US is big and rich and important so stuff that happens here has consequences elsewhere. That doesn't mean that this decision changes how the law works for everyone. Some countries already have service providers that do exactly what people in the US are worried will happen."
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7epafc | What happens to our feces in the sewers? | Other | explainlikeimfive | {
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"Vice had a nice video about [this]( URL_0 ). Slightly NSFW I guess, contains a lot of fecal images right from the start. In short, it gets separated from water and other stuff, like toilet paper, gets tested if it doesn't contain poisons or dangerous material and is dried and made into a compost."
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7epmk3 | How does cyanide kill people? | What does such a small amount of cyanide, ( like a pill in the movies), do to a person’s body so that it may kill them so quickly. Or does it? | Biology | explainlikeimfive | {
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"There's a chain of chemical reactions that your body uses to convert sugar (glucose) and oxygen into ATP (the chemical which the cells use for energy). Cyanide binds to one of the enzymes necessary for this chain of reactions which means the whole process is interrupted. The cells in your heart and central nervous system rely heavily on that specific process to make ATP, so they quickly stop functioning properly. The size of a pill is quite misleading since there are a lot of molecules of cyanide in a single pill. A single pill could easily contain *quintillions* of cyanide molecules whereas you only have trillions of cell in your entire body. That's enough for there to be around a million cyanide molecules in every cell.",
"You probably know the taste of cyanide, and have eaten some in small quantities. It has a very distinctive taste and smell. Cyanide gives marzipan, amaretto and sloe gin their unique flavour. It is also found in bitter almonds, and peach kernels. There are case reports of children dying after being fed baked goods containing apricot kernels. All these plants are from the rose family, rosaceae. Cyanide is in this plant family’s seeds to prevent animals chewing them and destroying their viability."
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7epz9n | In networking, what is the difference between a router and a hub? | Technology | explainlikeimfive | {
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"A router operates at layer 3 of the OSI model. It handles IP addresses, and decides where packets go based on the IPs store in the TCP or UDP packet headers. A switch operates at layer 2. It handles packet movement based on MAC addresses, which are physical addresses of interfaces as opposed to software defined ones like an IP address. A hub operates at layer 1. A hub is sometimes called a repeater, because that's exactly what it does. It takes any incoming signal on one port and replicates it across all other ports. It doesn't do any fancy logic. If your machine is plugged into a switch, you will receive only packates destined for your MAC address. If you are plugged into a hub, you will receive all packets destined for any device on that hub. Your machine will intelligently discard them, unless you want to keep them to... say, sniff someone's traffic. Very uncommon though. Pretty much everything you see nowadays is a switch or router. Your home router is actually performing both the router and switching functions in one, bit the differences in the 2 types of devices become very important in enterprise networking. Check our /r/networking for more info.",
"You can look at a hub as a kind of intersection in a busy street. Every vehicle can come in and go anywhere they want to. Except in a hub all of the vehicles that come in go to every street that is connected to the intersection. A router is like a smart traffic guard. They look at the vehicles that come in and tell them where to go, according to their destination. So hubs send messages they receive to every client that is connected and a router only sends it to the intended recipient.",
"The eli5 version: Assume you're sending a letter to your buddy who lives a few cities over. The mailman is the switch. His job is to pick up local mail from mailboxes ( aka switch ports ) and take it to the post office which would be the router. The postoffice looks at your addressing on the envelope and sends it off to another postoffice somewhere else. Each postoffice it passes through looks at the address on the envelope. If it doesn't recognize the address, the letters journey continues on to the next postoffice. If it does recognize the address, it gets handed to the local postman ( the switch ) and is delivered to your mailbox ( the switch port ). While beyond the scope of an eli5 explanation, know that the postmans job and the postoffice can be combined. This is known as a layer 3 switch which can do both jobs. Sort of like taking your mail directly to the mailboxes that are at the post office itself."
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7eq094 | How is it possible that ISP's can see what your up to online? I thought HTTPs encrypted your traffic so it can't be read? | Technology | explainlikeimfive | {
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"Sorta. The ISP is your mailman. They need to get packages to where they need to go, Reddit for example is sending you a package containing this reply. You pay the mailman monthly for a rate at which they send packages from you and to you. HTTPS encrypts the package’s contents, however the ISP’s responsibility is still to move the package from A to B, and therefore needs to know what these A and B are. Therefore the postage address cannot be encrypted, and your ISP can track who you are exchanging packages with, be it Reddit or YouTube or Netflix. So your ISP can’t actually see what you are viewing on Reddit, YouTube, or Netflix, but they can see which sites you are accessing.",
"HTTPS is not a perfect solution. It prevents them from seeing what messages are exchanged but not from seeing who exchanges those messages. They can see that you are on reddit but not which subedits you are viewing for example. There are additional things they can see. For example some researches a while back for example showed that you could still recognize which movies a person was watching despite them being transmitted via https. The transmission itself was encrypted, but observers could still see the size of the packets transmitted and match those with what they new about the movies in netflix's library. So https is good for not having the entire world see your password when you transmit it, but if you don't want your ISP to know that you are visiting URL_0 they won't help you at all and in some special cases they might in theory learn much more about your browsing habits than you would want them to.",
"I want to point out that my isp actually will perform man in the middle attacks to send copyright notices. I was torrenting one night and my browser wouldnt connect to https reddit. After a few seconds i got redirected to a 'copyright violations are bad, click here to restore your internet' page. Realistically, i should be able to charge them under the CFAA for that. I couldnt believe they would stoop to MITM for copyright.....",
"Your ISP doesn't know what you ordered from Amazon, just that you got a package from Amazon. This becomes an issue when you order a package from URL_0 , and there is little doubt as to what you're ordering.",
"It sort of does. Your ISP cannot read HTTPS data you send or receive (for the most part) But when you send data, they can see where it's destined for. When you receive data, they can see where it came from. So they can generally tell which websites you visited. But they can't tell what you *did* on those sites. There are a couple of ways they can *sometimes* snoop on your HTTPS traffic however. If you install one of their certificates, they can potentially act as a man in the middle, reading everything you send and receive. But that requires you to manually install this certificate. It can't be done silently just by visiting a website. Alternatively, if the website has a non-HTTPS landing page, they can potentially manipulate that so that you are never forwarded to the HTTPS version. But yeah, assuming your PC isn't compromised, and the *entire* site runs HTTPS, then the ISP can only tell where data packets are going and coming from, not what's in them.",
"They can see the volume. If you go to Pornhub for example and watch a video, you are going to pull down data from the video yeah it is encrypted, yeah it is streaming. If the video is exactly 14,586,304 bytes how many possible videos on the site are exactly 14,586,304 bytes? Even streaming wise with enough sample data you can peg what they are streaming. Go to a download site, same thing. I can't tell what you downloaded but I can see how much you downloaded. How many possible files on the site match the size? The ads are a different connection and unless a website has a substantial random amount of data on each page, it's easy to gauge what you are looking at. You can never get 100% but you can say \"Out of 6 million videos there is a 98% chance he watch video A, 87% chance it was Video B, and 76% chance it was video C.",
"Related: On March 28, 2017 congress passed legislation (bill: H. Res 230) that legally allows your ISP to track, store and sell your internet surfing history to ANYBODY who pays them money. This legislation was also passed basically \"under the radar\" just like they are trying to do with Net Neutrality. The bill was passed because 50 Republicans voted for it. On average a Republican received $368,648 from the telecom industry during their careers [ URL_0 ].",
"So my friend who owns my ISP knows what kind of porn I watch?",
"They know the IP address you’re sending/receiving information from, not the content. Quite literally just like properly addressed mail through the post office.",
"I work at an ISP and we can’t really see what you’re doing. We can see where packets are being sent, what time they’re being sent and who sent them, but that’s it.",
"They can’t see inside the HTTP session, but can inspect the entire TCP/IP packet. So, they don’t even know the host name in the HTTP header ( URL_0 ), but they can see the source and destination IP addresses. The mailman analogy works.",
"If someone moves your data for you, they get to read it. It's the same issue with Tor. No outsider can read it, but it is possible for outsiders, if they're creative enough, to become insiders. There's a small scene in Mr. Robot that talks about this briefly. I think it's actually in the pilot.",
"I've always thought of the post card anology. In http You exchange information with a web site in post cards. Everyone who handles your post card can read it. With https it's like using an envelope. They still know the address but not the content. The main thing to remember is that the website address is still visible. ~~So even if your communication is encrypted going to https: URL_0 /r/Am_I_Pregnant tell the ISP a lot~~ with https only URL_0 is visible thanks to /u/ChoilSport for pointing that out",
"This is the best link I have ever seen. URL_0 Basically, when you send information, like others have said, it gets put into a package, like a box. As the box goes from device to device, each device can add a box and put a sticker label on it. Some devices open the outer box package to read the label on inner boxes. Kinda like how you can recognize a home depot box, these labels and boxes are recognizable. And because it's all electronic, it's easy to build a software that can open and read those quickly and do all sorts of analytics. The very inside package might not get opened, but there's a lot of info you can gather to make very educated and statistically proven guesses in the worst case scenario, and when you compare it directly to other known packages from non encrypted sessions, it becomes a matching game.",
"I was actually looking into this the other day after my internet was slowed the day after I made a huge download. Turns out it was unrelated. However I found some interesting info about how service providers can determine your online activities without actually seeing the queries of your URLs. For example, when you're streaming a video, there is a specific bandwidth usage pattern that is easily distinguishable from downloads and stuff. [Here]( URL_0 ) is a diagram representing streaming network traffic pattern. When a video is buffering, it's pre-loading part of the video so that it can be viewed without any hiccups. Normally videos will give around 15 seconds of buffer time. When the video comes too close to the non-buffered part of the video (the rest of the video) the bandwidth will be used once again to buffer the next 15 or so seconds of the video. This results in a choppy, zipper-like bandwidth usage pattern. (See the hyperlinked article for a diagram). While service providers might not necessarily be able to see what you are viewing exactly, by combination of the general address of the website, and the bandwidth pattern. They can usually make a pretty good guess as to what you're up to. And with all the data they are collecting at the same time, it's only becoming easier. Edit: replaced link to article to simply just a link to the diagram"
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7eqa1l | How has the US ISP market become the duopoly it is today? | Economics | explainlikeimfive | {
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"text": [
"Put simply, it's *really* expensive to roll out wiring to every home in the country. In 2013, it cost Google $94M to deploy Google Fiber to Kansas City (480k population, 2.1M metro area, #29 in the country). Back in the 80s, when cable companies were rolling out their networks, they got massive tax breaks, subsidies, gifts from cities for right-of-way and all sorts of help because cities wanted to modernize & get the service to their citizens. Any company looking to build out a comparable system today would not see those benefits **and** be forced to compete with an established player with deep enough pockets to cut their prices until the new company went bankrupt. Originally, there were a bunch of smaller cable companies - often one per town - but, as tends to happen in business, they either merged or got bought out by larger companies until we reached the point where there's only a handful of companies providing the service. What happened to DSL? Basically, it just couldn't keep up. The fastest DSL available in my area is 20Mbps and that requires you to be right next to the DSL hub. Cable offers 200Mbps fairly reliably across the city. In some new developments, fiber is getting put down while everything's getting built but it doesn't look like it's going to older neighborhoods any time soon."
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7eqah4 | Can someone please explain Marxism? | Other | explainlikeimfive | {
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"To break it down into simple terms, Marx believed that conflict within society is the result of the disparity between the bourgeoisie (rich elite) and the proletariat (poor worker) in a capitalist society. The poor eventually get fed up with the elite reaping the rewards of their hard work and start a social revolution (since they vastly outnumber the elite), and implement a classless society, or a system of that nature. Marxist theories are the foundation for communism and many socialist ideologies.",
"\"From each according to his ability, and to each according to his need.\" Also: “I do think at a certain point you've made enough money” .",
"As simply as I can think to explain it, Marxism is the belief that the productive capacity of human civilization should be directed at meeting the needs of humanity directly. Marxism makes a distinction between what is called personal property and private property. Personal property are things that one person could reasonably be expected to own and utilize. Things like clothes, a computer, a cell phone, a car, a home. Private property would be a mine or a factory or a farm, the things that produce all the goods that modern society is based upon. Marxists believe that private property should be owned collectively to produce goods for all."
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7eqh2h | Why does breathing in through the nose and out through the mouth help with relaxation? | Biology | explainlikeimfive | {
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"I think the point is that your brain and your body has a two way communication. When you are happy that can make you smile. But if you take a pen or pencil and hold it with your teeth for 30-40 seconds, imitating smiling, that may get you in a better mood. The point of the breathing exersise is really to slow down your breathing. When we are stressed our breathing becomes more rapid and shallow. When we are relaxed, our breathing becomes slower and deeper. By breathing slow and deep you are tricking your brain into thinking that you are relaxed. Another exersise that works is counting to four while inhaling. Then count to four while holding your breath. Then count to four while exhaling. Then count to four before starting over again. 4x4.",
"I do not get why it helps people with relaxation. This never worked for me. As an anxious person if I try this, Im just worrying if im doing it right. Then when i want to quit it, i literally cant turn of \"manual breathing\" so i keep thinking about it, which makes me the opposite of relaxed."
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7eqq9o | Considering the huge profits to be had from cannabis, how does it "hurt big pharma"? | Economics | explainlikeimfive | {
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"Because right now they have pretty much zero infrastructure to get into the pot game; they don't have the facilities to grow, harvest, process or package it. When pot came out of the shadows, a whole school of cladestinely developed technique and art came with it, and as a result their competition isn't starting from zero, and is locking itself into a dramatically unexploited niche with a product that the big companies can't directly match without significant work and investment. In other words, someone other than them has an advantage in one particular field, and it's pissing them off."
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7eqrjf | why do we have trouble falling asleep when we felt extremely sleepy two hours prior to going to bed? | Biology | explainlikeimfive | {
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"text": [
"We look at our phones and the super bright light tricks our brain into believing it's not time for bed yet"
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7erfd9 | Why is blue light in electronic devices bad before falling asleep? | Biology | explainlikeimfive | {
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"text": [
"Human have evolved in a natural environment in which a blue light is associated with the daytime sky. The pineal gland secretes a hormone called melatonin which helps you to sleep, but it is supposed to do so only at night, which is to say, when it is dark. If you are seeing evidence of daylight in the form of a blue light, then the pineal gland does not secrete melatonin."
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7erm40 | Off Camera flash Duration and Shutterspeed | I've been reading about off camera flashes for a while now, but can't seem t figure out the whole logic behind the flash duration and it's relationship with the shutterspeed. I understand that t0.5 (t0.1) means the amount of time it takes for the flash to lose 50% (90%) of it's power, so if you want to freeze action it's best to have as short t0.1 as possible (does it depends on the max power too?) , What exactly would be a good t0.5 and t0.1 and how do you connect it with shutterspeeds? I've also been looking into [these flashes]( URL_0 ) for a while now and connect the theory with the written specifications as well. Anybody that could clarify? | Technology | explainlikeimfive | {
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"The flash duration and shutter speed are independent. However, many cameras use a double-curtain shutter, or electronic rolling shutter. The effect of these shutter systems is that at slow shutter speeds, the whole sensor is active, but at faster shutter speeds, only part of the shutter is active at any one time, and the activation travels over the sensor in a (relatively) slow fashion. If you use a short duration flash, together with a short shutter speed on such a shutter system, then the flash will only illuminate part of the image. So, to get around this, cameras have a specified minimum flash sync shutter speed, which is the fastest shutter speed where the whole sensor is active. (1/75 for older mechanical cameras, faster these days). The electronics in the camera would trigger the flash at the point when the shutter is fully open. Some cameras and flash systems, offer a special \"fast sync\" option, which allows the flash to illuminate the whole image at very fast shutter speeds - but what these actually do, is lengthen the flash duration so that the flash remains active for the whole shutter cycle (t0.5 = 1/50 or 1/75). In general, the faster the t0.1, or t0.5 time the better the ability to freeze motion. The speed you need depends on what you are photographing, how much motion there is in the scene, how fast it is, how close you are cropped to the motion, and how much blurring is tolerable. As a rough guide, 1/500 will freeze most human movement, except for things like the the feet in a runner or dancer; 1/1000 will be often adequate for ball sports, but 1/2000 may be required in certain conditions (e.g. close cropped shots of tennis).",
"It's been a while since I worked as a profession photographer, but here's what I remember from a couple years ago – Most modern cameras have a traveling shutter system. In essence there are two \"curtains\" – at the start of the exposure the first one is closed, then it opens all the way, then the sensor/film is exposed, then the second curtain slides over to meet the first curtain, ending the exposure. Both slide back to their initial positions (remaining closed the whole time). If you're using a flash, you want to fire the flash at some point while the shutter is fully open, so the flash has to dump its light during the open part of the exposure. This works pretty well up until faster shutter speeds, usually at 1/250th of a second (but higher or lower in some cameras). Beyond this point – the flash sync speed – the second curtain will start to close before the first curtain is completely open. At very high speeds what's really happening is that a narrow moving slit exposes the sensor. This allows for fast effective shutter speeds – 1/2000 – but there's no point at which the entire shutter is really open at once. If you fire the flash at these higher speeds (say, 1/500th on a camera with a 1/250th sync speed) only part of the sensor will be exposed to the flash's light. Fortunately, a \"high speed sync\" system allows the flash to be synchronized – I think through a system of lower power pulses - while the slit travels across the sensor. If the strobe takes 1/500th of a second to discharge 90% of its power, though, an exposure of less than that won't be able to get the full power of the flash. If you're using key flash (strobe provides the primary illumination), then you can treat the flash discharge time as if it is the shutter speed: set the camera for an exposure at the sync speed or below, dial back the ambient light to minimal, and fire away. If the flash takes 1/500th of a second to discharge 90% of its power, and you set it to full power, it's equivalent to a 1/500th exposure."
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7erp6m | How do small, isolated groups of people (like the people who live on small islands) maintain enough genetic diversity to avoid genetic defects in the long term, both in modern times and in antiquity? | Biology | explainlikeimfive | {
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"One primary thing is inbreeding really isn't as risky as most people think. You don't instantly get flipper babies, and marrying cousins was the norm in Western civilizations forever. One of the best ways to keep your money/land/wealth in the family was the classic \"keeping it in the family,\" rather than paying a dowry to some random stranger. The biggest risk with inbreeding is that it reinforces rare negative genetic traits and makes it much more likely that rare recessive traits will show up, because both parents share it. See hemophilia in the English royal family. So if there isn't a predisposition towards something like that within a population, it's hard to see the negative effects. Also, many of those small islands had some level of travel or movement between them. That was how people got on the islands to begin with. A couple people stupid/crazy/desperate enough to take off in a boat and end up somewhere else.",
"They don't have to. In small populations, bad recessives drop out very quickly, because they become expressed very quickly...If you have a nasty genetic disease, it won't lie dormant, it will kill people. After the bad recessives drop out, everything stabilizes, and the population can continue until some disease that no one has a resistance to kills everyone in a week. Inbreeding leaves you with a lack of genetic diversity, but that's only bad if something is around to take advantage of it. Otherwise, as long as you're not getting a bunch of nasty mutations or weird immigrants with lots of genetic problems, you don't need a very diverse population.",
"Inbreeding is also an efficient way to expose deleterious mutations and subsequently get rid of them. In addition, already a little amount of gene flow (outbreeding) can fix a lot of inbreeding. But then again, there are several examples of inbred populations that carry traits that confer problems. But as long as there are no competitors (you are isolated!) it may not matter.",
"They don't. These places typically do have higher risks of inherited genetic diseases. That said, inbreeding isn't instant madness, just a higher risk.",
"They don't, entirely. [Here's an article]( URL_0 ) about the problem of hereditary disease in isolated island populations.",
"I'm shocked an hour later no one has mentioned URL_1 yet. So short answer is: they don't. See the wikipedia page + there're quite many real-world examples: e.g. higher incidences of polydactyly among the Amish; and there's an unusually high incidence of Huntington's Disease within the population near Lake Maracaibo, Venezuela ( URL_0 ), etc.",
"There used to be an island in the Bahamas called (I can't remember) It was the only Island comprised solely of white people; Black bahamians were not allowed on the island after 6 URL_0 a result, there was a lot of inbreeding which was evident during visits we made to the island, ostensibly to tour the island, but really we went to look at all the mentally and physically handicapable people. I believe this genetic isolation of the island has changed.",
"Now I don't feel so bad for banging my cousin. Maybe the Girl Scouts will issue a guide line on that.",
"I had a friend that came from a small island in the Pacific. He said there was a weird little conversation that would happen when you were flirting with someone else that basicly went over relitaves. To make sure you didn't share any."
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7erpth | What do Singing coaches/lessons actually do to help their students' voices? | Biology | explainlikeimfive | {
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"They correct breathing, correct posture, correct pronunciation, correct phrasing, give practices that will help improve control/volume/range/accuracy/etc. They basically listen to what you are doing right and what you are doing wrong and give you advice specific to you and your current state of performance to improve said performance."
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7erq0q | Why do animals have different types of tails? | Biology | explainlikeimfive | {
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"They serve different purposes. Dogs have a variety of types of tails depending on whether they do a lot of running, climbing, or swimming. Cats, who spend a lot of time climbing on uneven surfaces have flexible tails that help them keep balance. Monkeys use them as kind of an extra arm, and can grab branches or items with them. It all depends on what was most advantageous over the eons."
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7erqfe | How do yeast/bread starters stay alive for years at a time? | Biology | explainlikeimfive | {
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"Think of a country. Individuals die off after about 80 years but leave progeny behind. As long as there is a reasonable supply of food and waste is removed, the country can last for millenia.",
"Yeast and bacteria can enter a state of hibernation. In sci-fi there are stories of people being put on ice. Bacteria and yeast can do this in real life. They stop their metabolism and are effectively rocks/dust. When you put them in water/sugar, they wake up and come out of hibernation.",
"Do you mean like instant yeast that's available in packets? It's generally active dry yeast or instant yeast which is living yeast cells protected by a layer of dead dry yeast cells. Or do mother cultures, as a method often used by commercial and industrial food processors? Please clarify your post. See also URL_0"
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7erz7n | How do agricultural markets function with supply and demand along with prices? | I’ve been reading a lot about grain, futures, and pricing models, but I don’t understand how they work in an agricultural sense. I don’t get how swine prices are affected by birth rates. If I have more pigs does that negatively impact the prices? I suppose this same question could occur with any product, but it would seem that a farmer would be incentivized to make less of a product to raise prices. I just don’t get it. Thanks. | Economics | explainlikeimfive | {
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"Governments intervene. There are enormous subsidies towards farming specifically to stop the situation you described. They are actively paid by the government to keep prices low."
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7erz8j | LLC vs S Corp VS "Forget it, I'm doin just fine". | Economics | explainlikeimfive | {
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"what do you mean you have \"zero liability\"? What kind of work do you do? What happens if someone sues you over a business matter? LLC introduces a measure of separation between you as a person and your professional work. All my business is done via my LLC, all contracts are in the name of the LLC, all payments are made to the LLC. If a client decides to sue me, they sue my LLC, because that is the entity that is a part of the contract. My personal assets are not owned by the LLC, so they are not at risk. [obviously there are a lot of caveats to this, but that's the idea]",
"> I have literally zero liability I really doubt that. If a defect in a product or service you deliver can cause someone else to lose money, you have liability. If confidential information your customers share with you can fall into the wrong hands, you have liability. And even if you don't have liability, that doesn't stop you from being sued for something someone thinks you are liable for. If you have an LLC or S-corp and get sued, your losses are usually limited to the assets in the corporation. If you can't afford to pay, the corporation goes bankrupt and your personal assets are protected. Without one, all of your assets, and likely your wife's, can be up for grabs.",
"LLC is a legal designation by a state to protect you from liability. It doesn't change the configuration of your business. You can be LLC sole proprietor, or LLC S-Corp in most states. S-Corp is a tax designation by the federal government to create a new legal entity, organized uber subchapter S. A small special type of corporation, with its own tax return, and tax requirements like payroll. This entity is no longer connected to you except that you are the owner and employee. Unless you're making 100k or have some other special circumstances, this will cost more than you can save. Edit to add: your taxes should take less than an hour. You should keep a speead sheet that you update each month with costs, milage, and income. It's easier to keep track of things monthly than yearly."
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7escds | How do Car Keys hold their charge? Do they get charged by the car? | Technology | explainlikeimfive | {
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"The battery holds charge like any other battery, it just lasts a long time because it uses so little electricity. You can open your key fob and change the battery if it runs out.",
"It's just a normal battery, it just doesn't take much juice to send the unlock pulse. Eventually they do run out, it just takes a long time.",
"it doesn't. it eventually runs out of battery. the circuit is very low powered and only turns on when you transmit the unlock button and the battery holds enough juice to last many years.",
"As others have mentioned, the battery does eventually die. You should know that if that happens, you're not stranded: you can almost always still drive the car. For instance, on my car (Toyota Prius), the key fob has a little latch that releases a mechanical key that will open the door, and if you hold the key fob against the car's power button, it will start even with a dead key battery. Check your owner's manual, just in case!"
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7eslg9 | Why were there tons of super giant creatures like dinosaurs a few million years ago, but there aren't now? Why did everything shrink in scale? Even a lot of bugs were much bigger then. Did Earth's gravity change? | Biology | explainlikeimfive | {
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"The prevailing theory is that our atmosphere had a lot more oxygen in it at the time (right now it's just over 20%). This let animals grow larger, especially with the scale of insects. Since most of them don't have a true respiratory system, they take in oxygen through their skin/exoskeletons. By having more O2 in the atmosphere, that made it easier to sustain larger size.",
"There's a few things to consider - Not everything shrunk in scale. Elephants are large. The blue whale is still larger than any dinosaur we have yet to discover. There are still plenty of creatures around today that are comparable in size to the dinosaurs. - There were smaller animals around during the time of the dinosaurs as well. There is a preservation bias when it comes to this. Larger animals are more likely to leave a trace we can find (i.e. it's a lot easier to find a T-Rex sized fossil than it is to find a chicken sized fossil) so it \"appears\" that there were much more larger creatures back then. - Time. Dinosaurs evolved over millions and millions of years. It's kind of like a long term arms race between predator and prey. Prey grows bigger, so predators grow bigger, so prey grows bigger, and so on. Larger creatures were much more susceptible to the mass extinction events that we think wiped out a lot of the dinosaurs - and there simply hasn't been enough time since then for larger creatures to evolve again. - Like /u/GenxCub pointed out. There was more oxygen is the atmosphere allowing animals (particularly insects) to grow much larger much more easily - /u/Phage0070 also raises a big point. The spread of humans has had a major impact both of the populations of megafauna and flora that existed at the time and the ability of new species of megafauna and flora to evolve. Humans put a massive strain on the natural resources of pretty much the entire planet and there simply isn't the \"space\" any more to fit large species. There's probably more things that I can't think of just at the moment but the simple answer is: There is no simple answer. There's multiple factors that effect how species will evolve and it's a combination of all of these that allowed dinosaurs to evolve to the sizes they did millions of years ago and it's a different combination of these factors that has prevented this from happening in the modern age.",
"That's not necessarily true, there's about 5-6 different whale species that are bigger than any dinosaur to ever exist, most notably the Blue Whale which absolutely *dwarf* even the largest dinosaurs. There are certainly plenty of big insects today as well.",
"That's an interesting question. The one thing that has not changed, however, is earth's gravity. As for insects the case is fairly well understood. Insects don't have lungs the same way we do, their respiration is more dependent on passive diffusion. This limits their size as smaller things have a greater surface to volume. Thus they could evolve bigger forms only in periods when the air oxygen concentration was higher. As for dinosaurs the answer is more complex. By far most dinosaurs were not very big. But we tend to notice the ones that were huge and spectacular. Nevertheless, the biggest animal ever to grace the planet is alive today: the blue whale."
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7etdmv | Why do young children laugh differently than adults? | Children laugh like *eh-eh-eh-eh-eh*, but we adults mostly laugh like *ha-ha-ha-ha-ha* or *he-he-he-he-he*. Why? | Biology | explainlikeimfive | {
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"I can’t stop reading the different laughs in my head. Eh eh eh is really creepy. Ha ha ha is really theatrical"
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7eunu6 | What causes the sticky, frictional feeling you get on your hands after using bar soap? | And why is bar soap the only soap that causes such a feeling (at least to my knowledge)? | Chemistry | explainlikeimfive | {
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"The soap removes your skin oils which provide lubrication that lets your hands feel smoother. Remove the oils and you get the friction feeling.",
"It had to do with how soap is made, a process called saponification (fat + lye (NaOH) = fatty acid salt (soap) + glycerin). When washing with soap the soap (fatty acid salt) reacts with minerals in tap water, usually magnesium or calcium, to make soap scum. The weird feeling on your hands is literally soap scum. The other answers are wrong because you can wash your hands with liquid “soap” (which isn’t technically soap but detergents) and strip your skin of oils and still not get that feeling.",
"r/soapmaking You can buy bar soap with lots of residual oil within that acts as a moisturizer - this is called superfatting. Basically the actual soap itself will take the oils off of your skin. That's why superfatting is so important."
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7eupo2 | How can different image file types differ so much in size for the same content even though visually there is no difference? | Technology | explainlikeimfive | {
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"The difference is how they store and compress the data. One format may use 24 bits per color per pixel. Another may use 24 bits per pixel reducing the number of shaded available. The next might use compression to store the data. With my camera a raw uncompressed file is up to 50 meg. Same image in jpeg is 5 but I have more useable information for editing with the raw file."
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7euqqd | When things are transparent (like a window, thin piece of paper), do the photons of the light source actually move through the object? | Physics | explainlikeimfive | {
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"Sort of. As you probably know, light has many different wavelengths. Windows let visible light in, but might not let other kinds with smaller wavelengths",
"Yes, how else would it get through the glass? Different types of matter have whats called a refraction index. It determines what % of the light bounces off verses what is let through."
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7eus12 | How were early civilizations able to calculate many, many decimals of π (pi)? And how did they know what they were doing? | Mathematics | explainlikeimfive | {
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"They were not. The best they got was seven or eight decimals- though with their mathematics they didn't think of it in terms of decimal places. The main method for determining pi's value was to figure out the perimeter of a regular polygon that fit exactly inside a circle (of diameter 1), and the perimeter of a polygon inside which the circle fit, and reasoning that the circumference of the circle (pi) must be somewhere between them. But geometry is tricky, and people ran out of geometric steam around the time they figured it out with 192-gons."
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7euykd | Why scientists can’t create a living organism from scratch | Biology | explainlikeimfive | {
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"A cell in itself is insanely complex. If a carbon atom is the size of a pingpong ball then an average cell would be the size of a large city in diameter. It is also as complex, regulating what enters and exits as well as creating and modifying molecules, performing a specialist task and if its a part of an organism, communicating with other cells and tissues as well as receiving information and reacting accordingly. This is one cell. Trying to get billions/trillions to form a functioning organism with organ systems etc. is even more difficult than trying to build something as complex as a city in a jelly blob smaller than the diameter of your hair. Tldr: life is far more complex than you’d think.",
"This is called abiogenesis, and it is currently the biggest mystery in the field of cell biology. We can create semi-synthetic organisms ( URL_0 ), but as of yet are unable to create completely synthetic organisms due to the problems that abiogenesis has thrown at us. Scientists are actively researching and pursuing this particular problem, as it is currently the last major barrier in the way of creating completely synthetic organisms with expanded DNA/RNA alphabets as well as having an extremely important role in genetic modification and other medical research fields.",
"Ask your boyfriend why he doesn't make an iphone from scratch, from just elemental molecules with no tools or other modern technology he doesn't build himself. It's effectively impossible, until you have built the complete infrastructure of an industrial society to build new pieces of the infrastructure of an industrial society. The problem is essentially the same for making cells. Basically, cells are made of machines so tiny we can't effectively build them using any technology we have, except cells themselves. It's almost like they are impossibly advanced alien iPhones that fell from the sky. We can understand some of what they do. We can play around and change the code some. But we can't build them from scratch with the tech we have right now. We can write DNA instructions using just chemistry, but in order to convert from DNA to RNA and then proteins, we need the machinery that does that process, which is itself made of RNA and proteins. It's like trying to make an egg without a chicken, or a chicken without an egg.",
"Even creating a drug from scratch to interact at specific receptor is insanely hard. It requires years of research, millions and millions of dollars, and thousands upon thousands of man-hours. And that's just a single molecule. There is an insane number of unique molecules like this inside a cell, in an insane number of configurations. Also, they don't sit still like you're building a house out of bricks. Bonds are constantly forming and breaking, new compounds being formed all the time. A cell is a sea of active processes, many of which (hell, MOST of which), we don't fully understand. Building a cell \"molecule by molecule\" is like trying to build a functioning copy of the World Trade Center (complete with all the furnishings), using nothing but tap water as building materials and chop sticks as your own only tools. We are so far away from this that is might as well be science fiction. If we were to achieve abiogenesis, it would be by dumping a bunch of naturally occurring compounds in a jar, adding energy in the form of heat and light, giving it a good shake, and hoping some shit happens eventually. URL_0 Watch the first half of this video for an idea of the scale of the shit we're talking about. Making specific strips of DNA or RNA is one thing. Building a cell from scratch is completely different.",
"DNA synthesis isn't that difficult, machines exist to do this, mainly to make PCR primers. Little copies of the starting and ending place you want to get out of the larger piece of DNA and allow the polymerase to keep copying that smaller piece you want. Technically, an organism has been created using artificial DNA but it was the most simple organism they could do and the procedure was not simple at all. News report of study: URL_1 Actual study: URL_0",
"Here are some nice yt clips about abigoenesis... URL_0",
"Probably one problem is that neither you nor your boyfriend really understand how complex biology is. This is nothing to be ashamed about, it just isn't common knowledge or even anything that is really emphasized in biology classes. For example, there are about 10 *trillion* cells in your body. Each one of those is tiny, too small to see. Tens of thousands of them could fit in the eye of a needle. But nonetheless, each cell contains *quintillions* of atoms. If every person on Earth, all 7 billion, started counting atoms at 1 per second (1, 2, 3, 4...), it would still take us *millions of years* to count all of the atoms *inside one goddamn cell*. Now imagine those atoms are grains of sand. That many grains is something like all the sand on all the beaches in Hawaii. Think of how complicated a sand castle could be if you built it with *miles* of sand. That will start to give you an idea of how complicated *each cell* in your body is. Beyond that, the huge amount of molecular machinery in each cell is itself very complicated. And there are millions of molecular machines in each cell to boot. They do thousands of different, intricate jobs, and we barely understand any of it at this point. You have lots of copies of your own DNA in each of your cells, for example, and DNA is a HUGE molecule - it contains billions of atoms. And each gets clobbered and smashed and broken by other molecules whizzing around inside the cell - and then repaired too by other molecular machinery - millions of times *per second*. That's all just in every single cell. And you have 10 trillion of them. There are 100,000 cells in the *brain* of a damn *fly*, for christ sake. So the reason why we can't build these things yet is because they are insanely, just *insanely* complicated. And they're wet, and everything inside them is moving at crazy high speeds. It's not the same sort of answer other folks are giving you, but I hope it helps.",
"Even the simplest of cells, are astronomically complex and have many interacting parts. What you have at the cellular level is the interactions of elements and compounds, forming molecules, and macromolecules. All of these pieces form the cell. From lipid cell membranes, to dna. The chemical structure of these are very complicated, and its not like you can just drag and drop things. It would be different if you were able to manipulate things at the cellular level easily, but you cant. Complex life needs complex steps to achieve it. Theoretically, since we know what DNA is made of, if you took single components and tried to make DNA, you may be successfull. Whether or not its A.Usable, and B.Feasible. Search the chemical structure of DNA. Making that is not easy. You need specific things to create it",
"Tell him to stop watching full metal alchemist. For a start we do not have the instrument precise enough to manipulate the molecules and arrange them in the right order. We've gotten quite good at synthesizing rather homogenous polymers like nylon and such in huge batches. but a cell is literally a small machine with many moving parts. We've only scratched the surface of 3d printing on a primitive level, so to imagine doing a full 3d cell on a microscopic level for which we sorely lack the instruments. Further, we lack the understanding on how cells function. Take proteins for example, it is a vastly complex 3d structure that folds into its final shape, and can change shapes depending on different conditions, this movement is kind of the basic machinery of a cell. Current computers are struggling to simulate even a single protein, never mind how a single cell is composed of vast numbers of interactive proteins. So in terms of understanding how a cell works, we're far from it. All in all we lack both the precise instruments to manipulate molecules and proteins, and also lack the knowledge on how a cell works. AKA we don't have the tools nor a blue print. So currently speaking its not possible."
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"https://www.youtube.com/watch?v=fgQLyqWaCbA&list=PLInNVsmlBUlREtDyJ2VpCLWK50Ua-cegZ"
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7ev0u6 | Why do our ears need to "pop* when we change elevations, and how does yawning make it happen? | Biology | explainlikeimfive | {
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"dq7nd0a"
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"text": [
"Air pressure has an inverse relationship with altitude. The higher you go, the less pressure there is. This is literally because as you get higher, there is less atmosphere sitting on top of you. Your middle ear is isolated from outside world by your tympanic membrane (eardrum), so it's like a sealed container, with a flexible window. When you gain altitude, the pressure outside drops, and the relative high pressure inside causes your eardrum to bulge outward. If you decrease altitude, the opposite happens, and the relative pressure increase on the outside makes your eardrum flex inward. Fortunately, your body has a built in relief valve to prevent your eardrum from rupturing (popping like a balloon). You eustachian tubes connect your middle ear to your throat, and allow any fluid buildup to drain, as well as any pressure changes to equalize. When you change altitude rapidly, like driving down a mountain, or ascending in an airplane, the pressure exchange can't keep up. Swallowing, or yawning, can help stretch your eustachian tubes open, to allow air to pass through rapidly, and release the pressure."
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7ev81e | When there’s a mirror scene in a movie or television show, how do they get the shot without showing the camera in the mirror, especially with a head on face shot? | Technology | explainlikeimfive | {
"a_id": [
"dq7nyzg",
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"text": [
"The \"head on\" face shots are actually shot at a slight angle. So the actor is looking at the camera in the mirror, and not at themselves. And in cases where it's absolutely impossible to shoot the mirror at an angle, they just edit out the camera using computer software in post-production.",
"Usually with rotoscoping, that is painting the camera and crew out of each frame with tools like photoshop. Shooting at an angle is another good one. James Cameron in T2 used a window and a 'mirrored' duplicate set. Sucker punch used body doubles.",
"They dress the camera up like the actor, throw a tie on it, and hope that you don't notice.",
"Sometimes it’s not actually a mirror but an opening into another room and they use doubles to compose the shot. They did this in Terminator 2 before computer trickery was good enough using Linda Hamilton’s twin sister."
],
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7ev9so | Why do snails ‘melt’ when you pour salt over them? | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"Because of osmosis. Basically, osmosis is a process by which water will travel from an area of low solute concentration to an area of high solute concentration until the two areas have equal molarity (moles of solute per liter of water). When you pour salt on a snail or a slug, you are introducing a very high concentration of solute (the salt) to its skin. Because the water in the snail's cells wants to equalize the molarity of the fluid in the cell with the salty outside environment, the water will rush from the inside of the cells to the outside. Because of this sudden exodus of water, the cells shrivel up. This makes it look like the snail is \"melting.\""
],
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40
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7evaza | In extremely cold weathers, why is it that we layer 3-4 and sometimes more pieces of clothing for our upper body, but not do the same for our lower body? | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"When we get cold our blood focuses on heating our organs and core. The simple answer is that we prioritoze our upper body because that's where all of our vital body parts are.",
"Canadian here, and I work 12 hour shifts outside: because you're silly. In the oil industry we don't do that. We instead layer multiple layers of sweat pants and sweat shirts, t-shirts and cotton pyjama pants as appropriate to regulate our heat well. Your aim is for full coverage of your body so that you feel completely comfortable. If you feel cold at all, you are failing to insulate properly. Insulating with just a heavy jacket basically is a strategy of sacrificing your extremities and keeping all your blood close to your organs because the rest of you is freezing.",
"The main reason is because you take care of your vital organs and they will look after You, In other words keep your vital organs warm and it will keep the rest of your body warm, Just as another point I absolutely hate the cold and always wear tracksuit bottoms under my jeans and two pairs of socks for the winter, It's also very difficult to put more than one layer of clothes on your bottom half as they normally get stuck at the knee so you need loose fitting jeans to put anything on underneath them."
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7evd4q | Why are Americans able to vote on the privatization of the World Wide Web? How will this affect the rest of the world? | Other | explainlikeimfive | {
"a_id": [
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"text": [
"The internet is not a public institution - ever since the US government stopped being a Tier 1 network in 1995, all Tier 1 networks have been privately owned, and the entirety of the internet backbone is privatized. Privatization has little to do with the net neutrality discussion at hand, and the only 'vote' happening is between two people and three morons at the FCC. As for why the US has a dominant role on the internet, that's because all major internet governance institutions were US founded and US based (ICANN, IETF, etc), and all standards and specifications were built in the United States.",
"1. The internet is already significantly privatized, but by multiple companies. 2. Traditionally those companies have run things in an equitable manner, charging flat rates for use of their networks, or entering into agreements where they can use each others networks as an even trade. For the most part, these companies aren't at issue. 3. Other more consumer-oriented companies, at the next level down, hook into those networks in order to get onto the Internet. Those companies are the ones that most regular Internet users deal with -- mostly phone companies, cable companies, wireless companies. 4. Those companies decided that they ought to be able to charge *other* companies, like Google or Facebook or Tommy's Home Page extra for the right to get data from the Internet backbone, into *their* network, and on to *their* customers. 5. After a few attempts, which were unpopular, the US government agency in charge of communication technology laws (FCC), when Barack Obama was president, made a rule that those second-level Internet companies couldn't charge extra to those content providers -- instead, those second-level companies need to be \"common carriers\" and treat all the data they get the same, not charge selectively. (This is how, for example, the telephone companies work. They can't charge, say, Geico extra to be able to call their customers. They just have to pass the call along like any other.) 6. Under Donald Trump's presidency, the head of the FCC was replaced with a new guy, who thinks the same way the second-level companies do: they should be able to charge other companies more for different Internet activity based on where it comes from. 7. This guy has announced that the FCC plans to decide, next month, to undo the rule made during Barack Obama that says the second-level companies can't charge extra -- and make it so that they *can* charge extra. 8. Suffice to say that the idea that the second-level companies can charge extra for other companies sending data to customers on their network would disrupt the traditionally free and open nature of the Internet, make it harder for some sites to get information out there to people, and really do nothing except put more money in the pockets of the second-level companies, who are already generally unpopular due to what is perceived to be anti-customer policies and overcharging. 9. The extra charge that the second-level companies would likely charge the websites would probably end up being paid by the users, with those sites saying that they need those users to pay extra to cover the costs they're being charged by the company that they get internet from. 10. The American people don't get to vote on this -- well, at least, the only vote they got was last November, when Donald Trump was elected, as well as a Republican majority in both houses of Congress (which is also in favor of letting those companies charge extra). 10. It would only legally affect networks based in the U.S. But the U.S. is a significant portion of Internet usage as well as Internet content, so the impact could likely be felt well beyond the U.S.",
"Expanding on the question, how is it that the FCC can single handedly repeal net neutrality? As a federal body surely they are subjected to some manner of oversight? I'm not very well versed in the american judicial system but surely this is something that can be fought in court? Especially in view of the overwhelming opposition to it.",
"The internet is already private. You need to pay a private company to connect to it usually. But luckily there's a law (in the US and in all the other countries) that imposes internet providers to treat all the content equally. In the US an ex Verizon lawyer and few other bribed guys are trying to change this law. If they succed this will directly affect US users only (but businesses all over the world can be damaged too). Also every other country will be indirectly affected, and every national telecom company will try hard to get what Comcast, Verizon, ecc. just got in America. There's too much money on the table for them to not try..."
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7evdre | Are flu shots an "all-or-nothing" protection, or do they also lessen the severity if you do get sick? | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"They essentially lessen the severity of certain strains of the flu. What happens depends on the kind of vaccine you get. Some do a weak live virus, some do dead virus. The point of the vaccine is to infect your body with what the CDC believes and predicts will be the \"MAJOR\" strain of the flu that year. Your body builds up antibodies to this. In chance you actually catch the full virus, your body will already have the antibodies built up to fight it. You will still have some symptoms, but they will be less severe. It is possible for you to catch a different or mutated strain of the virus which will render your vaccine almost useless, however."
],
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30
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7evsje | How do Flash bang Grenades and similar weapons work? | Chemistry | explainlikeimfive | {
"a_id": [
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"text": [
"Flashbangs are a pyrotechnic powder (usually some kind of magnesium/aluminum mix) and a small propellant charge inside a perforated metal tube. The fuse sets off the propellant charge, which blasts a cloud of burning pyrotechnic powder out of the holes in the tube. This creates a brief but incredibly bright flash, a very loud noise, and a substantial shockwave. Being in the vicinity of one is absolutely no fun at all."
],
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7evzf5 | Why is processed food significantly cheaper than unprocessed food? | Shouldn't the extra labor drive the cost up, not down? | Economics | explainlikeimfive | {
"a_id": [
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"text": [
"Typically because processed foods have longer shelf lives. Unprocessed foods spoil more quickly and require more infrastructure to make sure it gets to the consumer before it spoils. A pack of Oreos? That can sit on a shelf for a year, theres no rush.",
"It's not. Go buy a 10 lb bag of rice. It costs like pennies per oz. Compare that to a processed \"rice mix\" in a box, that costs up to 10x as much per unit weight. This is true for many commodities. Unless you're talking about fresh fruits and such, where there are considerable transportation costs and spoilage, like FBX said."
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7evzvu | Why does boiling water stop rolling when you stir it? | Physics | explainlikeimfive | {
"a_id": [
"dq7w0ft",
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"text": [
"When water is at a rolling boil, the hottest water near the heat source is becoming gaseous and forming bubbles. When you stir, you are mixing the cooler water from the rest of the pot in with the very hot water, cooling it down and preventing the formation of steam.",
"Your simply disturbing the convection current (heat rises) if the water was boiling at a higher temperature then it would require more stirring or a bigger spoon to stop the bubble"
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7ew08w | What is it about how sound waves interact that make some sounds/chords pleasing? For example, why does a 5th sound good but a tritone (diminished 5th) doesn’t? Why does it seem chords/chord progressions resolve? | Physics | explainlikeimfive | {
"a_id": [
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"text": [
"It has to do with the ratio of one sound wave's frequency to that of another. When the value can be expressed as a simple ratio, we interpret the interval as pleasing, or \"consonant.\" If the ratio is complex, we tend to interpret the result as displeasing, or \"dissonant.\" A perfect fifth, for example, is a 3:2 ratio, while a half-step is more like 15:8 and a tritone 45:32. Resolution follows similar principles, but it also heavily influenced by common notes, starting notes and the cultural dominance of specific scales in Western music."
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3
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7ew655 | Salt water oceans, but fresh water ice caps? | Most sea/ocean water is salt water, from what I understand. And most of the earth's fresh water is in the ice caps that are (I assume) in the salty sea. How does this work? Also why is sea water salty...? | Chemistry | explainlikeimfive | {
"a_id": [
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"text": [
"Greenland in the north, and Antarctica in the south, are composed of solid land underneath the glaciers. The ice caps are not in the salty sea, they are on land, although they do border on the sea, and icebergs break off into the salty sea and float away. Glaciers are formed by an accumulation of snow. If you have a cold, snowy climate where there is snow every year and the snow never melts, then you get an increasingly thick layer of snow, and then the weight of all this snow will compress the snow into ice, and when you have enough ice it constitutes a glacier. Snow does not contain salt because the water has effectively been distilled. When water evaporates, it leaves the salt behind. This would happen just the same way if you put a pot of salty water on your stove and boiled it. The steam would not contain salt, and when all the water boiled away, you would have all the salt left behind as a residue in the bottom of your pot. Sea water is salty because the sea has been around, here on planet Earth, for billions of years, and during that time various soluble salts have washed out of the continents and into the sea. It is a slow process but it builds up over time.",
"When water forms ice crystals it forces out other solutes like salt. There's no room in the well ordered ice crystals for other stuff. This is part of the reason salt and other solutes lower the freezing point of water. Any water that begins to freeze leaves the rest of the liquid water even saltier (which, after a point, becomes energetically very unfavorable). Basically, when you boil or freeze water, the stuff that's in it doesn't come along for the ride. The oceans are salty because salt is very water soluble. Over billions of years rain has fallen and rivers have flowed over the ground, picked up some salt along the way, and carried it to the oceans. That water then evaporates to start the cycle over again but the salt stays behind in the ocean."
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7ew6eu | Nabokov's quote "Solitude is the playfield of Satan" | Other | explainlikeimfive | {
"a_id": [
"dq7v4nd"
],
"text": [
"People are less afraid to be evil when they're alone. There's no judgements or voices to stop them. A murderers job is easier when there's only one victim. You can't stop what you don't see."
],
"score": [
5
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7ew8dd | how is it possible that food somehow makes me have explosive diarrhea less than 30 minutes after I eat it? | Biology | explainlikeimfive | {
"a_id": [
"dq7wi8e"
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"text": [
"It's not the pizza, but the meal before the pizza being ushered out that's causing the diarrhea. Basically, the pizza is rushing through the system and your body needs to make room for it so it forces out the other stuff before it's ready. Also, that food would be getting rushed out of the large intestine. The main job of the large intestine, which it didn't get enough time to do, is to absorb water from the stuff. Hence the movement being more liquidy than one might prefer."
],
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9
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7ew8vv | can a star with no galaxy exist? | Is it possible for there to be a star in space, but that it's not inside a galaxy? | Physics | explainlikeimfive | {
"a_id": [
"dq7von1",
"dq7vuf9"
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"text": [
"Yes. Stars can and do exist outside of the boundaries of galaxies. They are commonly referred to as stellar outcasts or intergalactic stars.",
"Yes, they are known as intergalactic stars or rogue stars. The first were discovered in 1997. It is believed they are born inside of galaxies, and later get ejected by close encounters with black holes or violent galactic collisions. Some theories suggest there may be as many stars outside of galaxies as there are inside."
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7ewkr4 | Are there any classic signs/symptoms that indicate someone is about to have a heart attack? | Biology | explainlikeimfive | {
"a_id": [
"dq7yim6",
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"text": [
"In the boy scouts we learned that a heart attack is characterized by: Nausea, Excess Sweating, Chest pain, Weakness/faintness, and Shortness of breath. Heart attack or not if you or someone around you had these symptoms I'd be pretty concerned",
"[According to the American Heart Association]( URL_0 ) > Although some heart attacks are sudden and intense, most start slowly, with mild pain or discomfort. Pay attention to your body — and call 911 if you feel: > Chest discomfort. Most heart attacks involve discomfort in the center of the chest that lasts more than a few minutes, or that goes away and comes back. It can feel like uncomfortable pressure, squeezing, fullness or pain. > Discomfort in other areas of the upper body. Symptoms can include pain or discomfort in one or both arms, the back, neck, jaw or stomach. > Shortness of breath with or without chest discomfort. > Other signs may include breaking out in a cold sweat, nausea or lightheadedness."
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"http://www.heart.org/HEARTORG/Conditions/HeartAttack/WarningSignsofaHeartAttack/Warning-Signs-of-a-Heart-Attack_UCM_002039_Article.jsp"
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7ewqmf | Can someone explain how what happens when you consume sugar? I hear terms like Glucose, Insulin, some gets transferred to fat cells etc etc | I just want to know what happens when our body consumes sugar or carbs. I am looking to choose a diet that will make me live longer. I heard eating a day and picking a Keto diet will do that. | Biology | explainlikeimfive | {
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"When you eat carbohydrates (sugar, starch or whole grains) it is digested into a chemical called glucose which is absorbed into your blood-stream. Your body uses this glucose as a source of energy. If the body can't immediately use all the glucose, it will cause the pancreas to secrete a hormone called insulin which in turn causes your fat cells to rapidly remove the glucose from the blood-stream and store it as new body fat. Later, when your blood sugar levels start to drop again, the pancreas will secrete a different hormone called glucagon which causes the body to reverse the process and break body fat back down into glucose again. The Atkin's diet works by limiting the intake of carbohydrates to around 20-50g per day. When you restrict your carbohydrate levels this much, it's very hard for your body to store fat. The body will actually change its entire metabolic process to one that uses fat instead of glucose as the primary source of energy. So Atkin's is an extremely effective way to rapidly lose weight. Keto is a variant of Atkin's that offers similar advice about minimal carb intake but recognizes that fiber, while technically a carbohydrate isn't digested into glucose in humans. So Keto allows you to ignore carbohydrates from fiber which is important because Atkins diets are known to cause constipation. A common joke told by Atkin's dieters is that on Atkin's they could eat bacon for every meal, which is obviously a bad idea for a long-term diet. Keto offers better guidance about the ratio of protein to fat intake and emphasizes healthier saturated fats over unsaturated fats clarifying some of the edge cases around eating narrow and unsustainable diets like the all-bacon-diet. So if you compared Atkins and keto you can think of Atkin's as the original, focused on rapid short-term results, and keto as the version 2.0 focused more on long-term sustainability without sacrificing results. Check out /r/keto for stories from people who completely turned their lives around by following a high-fat, low-carb diet. It is truly amazing seeing some of the pictures people post there.",
"FYI, eating healthier doesn't equate to living longer. If you want to live longer then eat bland foods with the basic requirements to survive, and NEVER eat any more than you need to survive. The more you eat beyond minimum, the increased chance you'll die earlier. It seems odd, but there actually is reason behind this concept. Basically, the more often your body runs reactions to to breakdown materials (anything you eat) and create things from the stuff you ate, the more likely your body will accidentally damage itself from these reactions. If you want to read more into this, take a look at the major signaling molecule mTOR and also free radical production."
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7ewquy | What is biohacking and how would of work if we could do it? | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"Biohacking is typically where a layperson or scientist who wants to be sensationalist markets medical procedures which are usually unsafe or outright lies to the general public to make it sound cool. It works the same way as regular medicine except you're supposed to feel it's cool. Example: Criminally negligent PhD. student: I'm gonna biohack your workouts with this quantum serum. Doctor being ethical: There exists a gold nanoparticle treatment which increases muscle mass. I will have to do several tests to see if your outcome from this procedure will lead to a better quality of life. After weeks of testing we will have an evidence based recommendation for you."
],
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7ewu8m | Maternal haplogroups mean we're all descended from the same woman? | I'm reading on 23andMe, trying to understand my results, and it says this: > If every person living today could trace his or her maternal line > back over thousands of generations, all of our lines would meet at > a single woman who lived in eastern Africa between 150,000 and > 200,000 years ago. Though she was one of perhaps thousands of > women alive at the time, only the diverse branches of her > haplogroup have survived to today. The story of your maternal line > begins with her. I'm confused. Why would there be only one woman whose genes survived through the generations? Does this mean that everyone alive now has a common human ancestor? | Biology | explainlikeimfive | {
"a_id": [
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"text": [
"Who you're describing is called \"mitochondrial Eve\". Basically, all of our mitochondrial DNA traces back to this one woman, since mitochondria is passed on almost exclusively through the egg. Because of this, we can track the ancestry of all human cells, and they all happen to converge to one person. This person is the most recent common matrilineal ancestor of all humans, but she is not the most recent common ancestor of all humans.",
"Yes, everyone alive now is related to this one person. But its not just that. You can trace every human and every chimpanzee to a single ancestor a long time ago too. More than that . Every single living thing on this planet is descended from a single organism, a bacteria or something similar to it, that lived 3.5 billion years ago.",
"Think of it this way: For each generation the likelihood of a matrilineal line dying out increases. This can happen in two ways: 1. The women in the matrilineal line have no offspring. 2. The women in the matrilineal line have only male offspring. As thousands of generations go by, one of the two become increasingly likely, until there are only one matrilineal line left alive. That doesn't mean the other women's genes didn't survive, it just means she's the only woman who can trace her ancestry down from 200000 years ago to today **through an unbroken line of daughters**. Or think about it this way: all the women who kept their matrilineal line alive would have had at least one daughter, and some would have had **more** than one daughter. This means the ancestral tree eventually converges to one individual as we move back in time. She is called mitochondrial Eve, since the mitochondria is almost exclusively inherited from the mother. There's a male equivalent, Y-chromosome Adam, who lived around 200,000 to 300,000 years ago. It is possible, but not likely, that mitochondrial Eve and y-chromosome Adam met each other. Everyone alive today does share a common human ancestor, but he or she lived more recently than either Adam or Eve."
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7ewurn | What happens that makes beer taste terrible after warming up and then re-chilling? What makes beer 'skunky'? | Chemistry | explainlikeimfive | {
"a_id": [
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"text": [
"Skunking occurs when beer is exposed to certain wavelengths of light. This is why beer is typically bottled in brown bottles. Clear and green bottles protect the beer less, which is why popular brands in those color bottles often have the distinctive flavor. The chemical responsible for the distinctive flavor is called MBT, and is produced when the energy in light causes the riboflavin (produced by yeast during fermentation) in beer to chemically react with the alpha acids from the hops.",
"Warming and re-chilling beer does not make it \"skunky.\" Light interacting with the hop compounds causes the skunkiness. That's why it's prevalent in beers that use clear glass. And that is the reason Corona pushes the whole lime business. As far as glass goes, clear is worst. Green offers some protection. Brown offers the most protection. Cans, however, are king.",
"Thanks! I knew the container had an effect on taste but not to that degree. It's actually very neat information."
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7ewwjh | What's the difference between UEFI and BIOS? | Technology | explainlikeimfive | {
"a_id": [
"dq80znr",
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"text": [
"UEFI is the replacement specification for BIOS - it does the same basic role of bootstrapping on launch, but BIOS has a host of technical limitations owing to the fact that the original specification is nearly 30 years old and unable to work with some modern hardware (for example, BIOS can't work with a hard disk of over 2.1TB). An easy illustration - any newly built computer that boots into UEFI will have usb mouse support. No such luck on an old AwardBIOS.",
"Every computer needs some *firmware* that tells it what to do when it first powers up, before it starts loading the operating system. The firmware for the original IBM PC was called BIOS. Every x86 PC clone since then has been designed to be backwards compatible with it and suffers from a bunch of limitations due to that. At least until UEFI came out. UEFI is a modern replacement for BIOS, designed from the ground up, based on the needs of modern systems. For starters, it can be a larger program - this allows you things like a GUI, the ability to go onto the network to get updates & room for a bunch of diagnostic/repair tools."
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7ewz80 | Why are some people given 400+ year sentence and others a lifetime sentence? Any difference between the two? | Other | explainlikeimfive | {
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"When this happens it is normally because they have multiple crimes that have the punishment of life or similarly long sentences that are being added together. They do this because each crime deserves justice and each crime needs to have their punishments completed. This also means that if one conviction gets overturned or if they pass the parole requirements for it that they still have to serve the others or meet their parole requirements separately.",
"Sometimes that is just how the legal math works out. If you rob ten banks, and the punishment for robbing a bank is ten years, 10 x 10 = 100. Also, it keeps sentences from becoming confusingly entangled. If you just got life in prison for robbing those banks, what happens when one turns out to be a copycat? Do you go free? Do you stay in prison for 90% of your life expectancy? Keeping the sentences separate makes it easy to drop anything that gets overturned or otherwise modified. Finally, it can give prosecutors political cover for plea bargains, especially in cases where the death penalty applies. Trials are expensive, capital cases doubly so, and are often overturned on appeal anyway. A plea bargain with a crazy high impossible to serve prison term will often mollify a public demanding execution for a high profile crime."
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7exj5h | As the universe expands, what is happening on a micro level where new space is being created (or stretched)? | I read a comment on Reddit that piqued my interest and have been trying to find some deeper info on the subject. The comment basically said that as the universe expands, something on the Planck level is dividing like cells, producing more space. I'm not asking for an explanation of that concept, but rather wondering precisely what is happening on that scale when space expands. | Physics | explainlikeimfive | {
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"Nothing is dividing at micro level. Space itself is expanding. From our reference point, this is driving distant galaxies away from us. Imagine two dots on a balloon. They are galaxies. When you blow the balloon, two points are driven apart, and the molecules of the balloon are stretching, not dividing. This is not something we can measure on Earth. We were able to measure gravitational waves on Earth, but the expansion of space is much slower than that; approximately 0.007% per million years. Space is expanding everywhere, but objects that are bound together by any force, such as atoms in your body or galaxies in our Local Group, are not driven apart from each other."
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7exlio | How is it possible for any politician or official to endorse a candidate without violating the Hatch Act? | Other | explainlikeimfive | {
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"The Hatch Act specifically prohibits employees of the Federal Government from using the personal influence and official authorities given to them by their job, to interfere with an election. The Act has provisions which specifically allow the President, Vice President, and other high-ranking members of the administration to engage in most kinds of political activity. Furthermore, the Act also specifies that individuals employed in the Federal Government are allowed to engage in limited forms of political activity. Basically, the idea is to make sure the employees of the Federal Government remain non-partisan and don't use their positions of authority to leverage support. So, people working in positions at the Department for Homeland Security aren't explicitly allowed to support a political cause or use the powers afforded to them by their job to turn departments of the government into partisan support-bases.",
"The Hatch Act applies to officials in the executive branch. These people are either appointed or hired for jobs and are, by definition, not elected politicians. So, simply put, the act doesn't apply to elected politicians."
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7ey00p | Why do mostquestions seem to get answered? | Other | explainlikeimfive | {
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"Most ELI5 questions are honestly LMGTFY territory. Much of the rest is stuff that a lot of people know off hand. Only a slim minority are really in depth questions requiring deep knowledge of the subject to answer. To be blunt, if you're in a position where you're asking a question so in depth you need an answer from a real expert in the field, you're probably not asking it on reddit."
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7ey0xr | How can dust float in the air? Surely the dust particles are heavier than air, so they should sink. | Physics | explainlikeimfive | {
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"Because there is wind! The dust rides this wind like a paper airplane, except it doesn't need nearly as strong of a wind to stay up for a long time. Imagine the game I am sure you have played with a balloon and keeping it from touching the floor. The dust is the balloon, and the wind is the people kicking/hitting the balloon to keep it up. Except this happens at really tiny sizes. Because we are huge to the dust, we don't feel this \"punching\" from the wind, but the dust most certainly still does.",
"Generally dust has a density just slightly above air causing it to fall downwards. However air is made of various gaseous particles. The dust collides with these particles on its way down causing it to slow down, and appear as if it is floating"
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7ey3t3 | Why SMS messages cannot come in Bold/Italic/Underlined, etc | Technology | explainlikeimfive | {
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"Technically, they can. But the support for such formatting has to be widespread and unified between phone hardware manufacturers for it to be useful, which is obviously not the case now. Also, the SMS protocol has been designed with a limited message length in mind, adding the formatting would make the message even shorter."
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7eyfgi | Comorbidity of Mental Disorders | Hey friends, It seems like when one type of disorder is present, it's usually not alone. What's up with that? Myself for example am a poster-boy of this: OCD and tourette's go hand in hand, and they're usually accompanied by anxiety (check,) and / or a mood disorder (check.) They all roll together, likes fucked up buddies. | Other | explainlikeimfive | {
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"In psychology, the way we look at the likelihood of your acquiring a certain mental disorder is through the diathesis-stress model, with the diathesis composed of genetic factors and existing traits (usually defined in terms of OCEAN: Openness, Conscientiousness, Extraversion, Agreeability, and Neuroticism) and the stress being life events or environments. Problem is, many mental disorders share common traits that make it more likely for you to acquire them. Some examples are Generalized Anxiety Disorder and Major Depressive Disorder; if you’re high in introversion and high in neuroticism, it increases your diathesis for them. Actually, the combination of these two traits increase your diathesis for many mental disorders. Other combinations increase diathesis for other mental disorders so on and so forth. Your diathesis combined with stress coming from events such as the divorce of a parent, loss of a loved one, toxic peer and family environments cause the occurrence of a mental disorder. In short, many mental disorders occur in comorbidity because they have very similar causal factors :)"
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7eygyr | Why can't retail deodorant sprays (Axe, Old Spice, Dove) replicate the fragrance of boutique colognes (Burberry, Hugo Boss, even CKs)? | Chemistry | explainlikeimfive | {
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"They could if they really wanted to, but they won't. Ultimately because it doesn't make business sense. Boutique fragrance houses sell a particular scent. This is their primary product, and everything else is just an accessory. This can also typically involved dozens or hundreds of exotic ingredients, because designer scents are extremely competitive. As you can imagine this makes producing a designer scent quite expensive. The price reflects this. Even when you buy the \"deodorant\" version of a Burberry or Boss fragrance, this is still more expensive that your Axe or Dove. This is mostly down to ingredients, but there is also some \"brand equity\" that gets tacked on to the price (not as much as you might think, but often a little extra). So the main selling point is the distinct fragrance. You don't buy Calvin Klein deoderant because it's the best one on the market. You buy it because you want that CK smell that you can only get from CK (which also happens to be available as deodorant). On the other hand, your Axes and Doves are designed primarily to be *effective* rather than for a particular fragrance. You buy it because you need deodorant, rather than what it smells like (though scent does play a role in preferences). You might prefer the Old Spice to the Dove due to the smell, but this is not the primary reason why you buy deodorant in the first place. Therefore, why would Axe or Dove use expensive fragrances to produce their scent, when that is not the primary selling point? They don't! They create simple fragrances using easily available ingredients, and focus more effort on making better deodorant. As for the \"locker room scent\" of common deodorants. Have you considered that this smell is created due to the popularity of particular deodorants? Rather than Axe trying to replicate the smell of a locker room? If a product gets used a lot in an enclosed space, I would expect this smell be pervasive in that particular room. Tl;dr So your CKs and Burberrys are selling a designer scent, which also happens to be available as a deodorant. \"I love that CK smell, I wish it was available as a deodorant\" Your Axes and Old Spices are selling a deodorant, which also happens to have a distinctive smell. \"I need deodorant, I guess this one smells better than the other one\". This is the difference."
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7eynab | How do smelling salts wake you up after you’ve been unconscious? | Also as a side note, could you sniff them to keep you awake? | Biology | explainlikeimfive | {
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"They release ammonia gas. Ammonia is an irritant that triggers an inhalation reflex, which also increases heart rate. This cancels the physical effects of fainting - a reduced heart rate, breathing and metabolism in general. It won't keep you awake, but it can keep you from passing out in certain situations.",
"Smelling salts are truly vile. It’s very strong ammonia. It doesn’t “smell bad” it’s a chemical attack in your sinuses that you can’t ignore, like tear gas or something. Years ago when I worked in the ER there was a particular challenge. Habitual drunks would come in literally comatose. If you monitored them and gave them some IV fluids they would always wake up safely, in time. BUT a small number would come in drunk AND with a life threatening brain injury (often with little or external trauma, from falling down...drunk) . How to tell the difference? You can’t do head CTs in every drunk in a busy ER (and some habitual drunks would get like 80 CTs a year). Enter the supertucci brain injury severity test. I would crack one of these and cram (I mean gently place) it up one nostril. If they couldn’t muster the 10 neurons to pull it out (and they really wanted to pull it out since it is so obnoxious) it was OFF to the CT scanner for a sometimes life saving scan. On average my ER has one case a month of a drunk who didn’t sober up over time, got a CT and only then we realized he also had a brain injury we’ve been sitting in for hours. I had zero. 25 years later I still feel good about that. Edit: drinks to drunks (sorry on phone)",
"When I was about to faint in the hospital they had me sit down and sniff an alcohol wipe. Why did that work?",
"So when I was taught to examine cranial nerves in medical school, I was told to not use the always-available alcohol wipes to test the olfactory nerve (the nerve that lets you smell things.) Reason being noxious stimuli actually trigger sensation in the nasal mucosa, which is the trigeminal nerve, rather than stimulating the olfactory nerve. Smelling salts cause pain in the nasal mucosa, not an actual smell, that jolts you back into consciousness. Kind of like being slapped or getting a bucket of cold water dumped on you. Edit: ELI5. Right. Sorry. Smelling salts don’t smell you awake, they hurt the inside of your nose to wake you up.",
"i used to be a sideline guy for the toronto argos (football) team and the guys were using them like crazy. before the game, during the game, between plays, they were getting hyped off them. i took a couple just to mess around with and they are really something unique. imagine smelling a combination of gasoline, vinegar, and other acidic stuff. it goes straight to your head and kinda jolts you",
"I was 17 and got hit in the arm by a hockey puck when I was on the sidelines. It hurt but not terribly. About two minutes later I start feeling nauseous and practice is almost over. I felt too sick to walk to the lockers and I sat in a chair in the office. The coach starts calling for a nurse and I’m like WTF is his problem. I’m just a little nauseous... and that’s when I realize I can’t physically respond to his questions. The next thing I remember is the smell of the ammonia from the smelling salts and waking up. It had been over five minutes since I offishully passed out. That was the second time they had tried to use them to wake me. The first time they said I briefly woke up and passed out again. Don’t remember that part. I will never forget that smell. I’m alive 30 years later.",
"I often see pro soccer players and NHLers sniffing something before the game (haha i know what you are gonna say). Is that the same stuff?",
"Typically they contain ammonia, which forces a reflex. It doesn’t always work, and they’re used to keep people awake rather than waking people. If you ever get a hit of ammonia you’ll understand just how potent the reaction is.",
"I was born with anosmia (lack of sense of smell) and have always wondered if smelling salts would work on me. Do they trigger a physiological reaction separate from smell that would wake me anyway?",
"The sense of smell is linked directly to your sense of memory and emotion, it doesn't \"re-route\" through the frontal cortex. Thus you can deliver a jolt \"directly\" to the \"inner\" part of the brain that can kickstart the cortex. Interestingly, or perhaps rather morbidly, this can be used in \"fake torture\". Burn some pigskin with a blowtorch as you place a freezing cold metal rod on a blind-folded person's skin. Instant brain-torture.",
"They were mainly for fainting, which is somewhat different to unconsciousness, not least as some of the fainters were probably being melodramatic (such were the times) and the salts were unpleasant enough for people to chose another way of expressing their distress.",
"You can sniff them to keep you awake, actually. Inbetween periods, my team will crack open a few and pass the little packets around. You take a whiff of the salts and the intensity and potency of it really opens your eyes. It's almost like a drug, without the harmful effects.",
"Smelling salts wake you up because the sense of smell is processed differently than other senses, via the olfactory nerve. Every other cranial nerve is passes through the thalamus, which can be thought of as the sensory relay in the brain. The olfactory nerve goes directly to the brain. Thus, if you pinch someone or yell at them those sensory inputs can be if or because the thalamus says to. The smell cannot be ignored and you are awakened. This is also why smell is so closely tired to memory.",
"Side note - you can't 'smell' anything while asleep. Smelling salts work as an irritant that causes you to wake up. If your wife farts in bed and you're asleep, you would only wake up if it irritates your respiratory system or is loud enough to wake you...",
"Smelling salts release ammonia (NH3) gas, which triggers an inhalation reflex (that is, causes the muscles that control breathing to work faster) by irritating the mucous membranes of the nose and lungs. Fainting can be caused by excessive parasympathetic and vagal activity that slows the heart, and decreases perfusion of the brain. The sympathetic irritant effect is exploited to counteract these vagal parasympathetic effects and thereby reverse the faint.",
"Were u watching stranger things when u first thought of this?",
"You should not use these to keep you awake. They contain ammonia, a toxic irritant. There's a reason they're only used on unconscious people, and sparingly. Longer exposures can be harmful.",
"Smelling salts for staying energized is a common practice that's been around for years in the NHL. All most all teams have a giant pack of them laying around for player use in between shifts. Even NFL players like Ezekiel Elliot have started using them for the same effect. My hockey team uses them as well before games and it actually really gives you a nice boost of energy before doing various activities. Just don't get addicted and don't smell like 10 of them.",
"There was a union strike here in New York. The scab non-union guys were working underground doing work on cables. They had their trucks working putting light out and had ventilator pumps sending fresh air below. The union guys showed up and demanded the scabs get out. They said fuck off etc. They were not coming out. Union guy takes a bottle of ammonia and pour it near the ventilator fan intake. The scabs flew outta that manhole. 17 year old me learned a lot about unions & scabs that day. Scabs had a bad day."
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7ez2sf | How far can electricity travel down a power line? | Does electricity travel down a power line indefinitely? If you had a power station in France, and you somehow have a super long power cable connected to australia, will the power station be able to send electricity to australia? If not, where does the electricity go? | Physics | explainlikeimfive | {
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"A far as you like. Some will be lost to the resistance of the line (it becomes heat). That heat is sometimes called I squared R losses, because it's proportional to the resistance (R) multiplied by the the square of the current (I). So you can reduce the amount of loss by reducing the resistance (not really practical) or lowering the current. But how do you send the same amount of power at lower current? Up the voltage! That's why long-distance transmission lines use such high voltages. Which is one of the reasons we use AC power; it's much easier and cheaper to change voltages with AC power than with DC power, so you can transmit it long distances cheaply and with little loss, then make it safe for consumers to use.",
"The short answer is that yes, this is possible but it will depend on how much energy the lines have to carry, what voltage they operate at, the electrical resistance of the line (which is affected by the metal used, it's thickness, and loads on the line like transformers, peoples houses connected to it, etc. Generally speaking, for power transmission it is possible to overcome much of the electrical resistance of a wire by increasing the voltage. High voltage and lower amperage, sends the same amount of power down a wire as a lower voltage at a higher amperage, but it encounters less resistance on the wire as less of that energy is expressed as heat. The higher the amperage, or amount of power being delivered, the more electrical energy is converted to heat. A light bulb for instance glows because the tiny filament wire in it has a lot of current going through it, more than the wire can handle, so it heats up until it glows brightly. Think of a gun. Amperage is like the total mass of the bullet, and voltage is like the speed at which it's shot. Wattage is the total power of speed multiplied by mass. If you have a gun that shoots single electrons, they are traveling at a good amount of the speed of light, but they have almost no mass, so not much energy is sent. On the other hand one that shoots bowling balls at 10 miles an hour is pretty slow, but they are so big they start to do damage. Electrical lines operate with lower resistance if you \"shoot rice grain sized bullets at 10,000 miles per hour\", where as normal household power is more like \"large rocks hurled at a few hundred miles an hour\" Long distance powerlines operate at blistering voltages and how far they run is more of a matter or economics than technology. At a certain point it becomes cheaper to build a closer power plant than to create one massive power plant, and try to deliver it's power hundreds of miles away. Say that you are trying to push a shopping cart. Pushing just a few feet of cart is pretty easy. But pushing several carts, or one very long cart, would get harder and harder. Eventually you could find a shopping cart that's distance was so long, that you couldn't push it at all, it would just stay in place as you struggled. You're putting work into pushing it, but it's not moving, so where does the energy, or work you put into pushing it go if it doesn't move? Think of it like a balancing act. You exert a force, and that force is resisted by resistance because of friction, entropy, and all that stuff. If the force you exert is greater than the resistance, then the difference is energy that does work. If however the resistance is higher than the force exerted on it, then no work is done and the energy or work, put into it is turned into heat from the resistance. This is true whether you're talking about current moving along a wire, or friction from a rolling wheel. (to be honest, some of the force in a wire is also lost as it's converted to electromagnetic energy which radiates out from the wire.",
"No it cannot travel indefinitely. It's actually a common problem when trying to move electricity over long distances. Usually what we do is increase the voltage so the loss is reduced over longer distances. Electricity is not a thing it's just electrons moving around. So over long distances those electrons will likely hit some atoms and lose their energy producing heat. Likelyhood of electrons hitting atoms depends on many things such as the material, length and radius of the wire. Electrons move because they experience a charge. Like magnets like charges repel. So on one terminal they'll be an abundance of electrons all of which are trying to get away from each other to the positive side. If there is no difference in charges current won't flow i.e. electricity won't travel. If you want to google this stuff search for power transmission.",
"There are several problems with sending power down a long power line. These problems depend on many things: the total amount of power, the voltage, whether you are using AC or DC and the design of the power line (overhead power lines, underground cable, or underground power pipes). The biggest problem is \"resistance\". This is the fact that there is always a bit of \"friction\" when you push electricity through a wire - just like friction when you push water through a pipe. Resistance interacts with the electrical current to waste energy as heat. As others have said, there is a way to reduce the resistance problem, which is to increase the voltage, because higher voltage allows the same amount of power to be transferred with less current. AC power can easily have voltage increased and decreased, so you can use 120 V for homes, and 500,000 volts for power lines connecting 2 cities. AC power has some additional problems however. This is a complicated concept called reactance, which can also limit the capacity of a power line. It is possible to compensate for reactance, by adding \"compensation equipment\", but this is expensive. Reactance is a big problem for high voltage underground power lines. At low voltages (like 120 V) resistance is the main problem - the lines can't be longer than about 1 mile or so, before the resistance is too much of a problem. But at 500,000 volts the reactance is the main problem. The maximum length of underground (or under water) 500,000 cable is about 5-10 miles, before you need a compensator. So, if you want to use an underground/underwater cable, then you have to design the cable voltage carefully, to balance the power wastage from resistance, to the cable limit due to reactance and whether you can put compensators in place (you can install a compensator yard on land no problem, but you can't in the middle of the ocean). The solution to the reactance problem is to use DC power instead of AC power. This requires very expensive power converters at each end of the power line ($100s of millions for each end), but it has the advantage of getting rid of the reactance problem completely, and it also cuts the resistance problem in half, allowing overhead lines to go further. High voltage DC power lines can go thousands of miles over land. The longest underwater DC cable is 360 miles from Norway to Netherlands, but longer ones are planned of up to 1000 miles."
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7ez3v2 | How do lungs work? | Biology | explainlikeimfive | {
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"A lot of it is their surface area. They also have a huge amount of elasticity. Finally there are amazing chemicals which coat the surface of the cells in the alveoli. Start with the nose and mouth. They allow air into the bronchi. It crosses the eating tube and an amazing valve keeps things sorted out mostly.The bronchi branch into bronchioles which branch more and more. When you see bronchi you can just say air tube. The tubes get smaller and smaller. Finally they end in little sacs called alveoli which have the tremendous surface area and the fantastic chemicals which allow them to stay open. Gases diffuse across the membranes of the alveoli and into the blood stream. Carbon dioxide also diffuses across the other way due to their being more in the blood than the atmosphere. Muscles expand the chest which means air moves into the lungs. Then the chest contracts so air moves out. The fresh air in the alveoli means gas diffusion takes place. Oxygen moves into the blood. Carbon dioxide leaves. Sometimes the alveoli fill with fluid and you have pneumonia. Sometimes air or fluid gets between the lungs and the chest wall. This is serious. Sometimes the flow of blood and the amount of air changes and you have a mismatch between the right amount and what is happening."
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7ezg8c | What are the chemical changes which occur in Lithium ion batteries after prolonged usage which renders them unusable? | 1. Why does charging time and backup time both decreases after few years of usage? 2. Why does battery percentage of old mobiles with Li ion batteries drop from say 60% to less than 10% suddenly? | Chemistry | explainlikeimfive | {
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"In general batteries are 2 different types of metals soaked in acid. The exact composition of the metals and acid determine the types of battery. In a perfectly rechargable battery, the chemical reaction that occurs when the battery is in use is reversed when the battery charges. This is never the case. Each recharge cycle introduces some amount of impurity. As impurities build up the battery degrades. Batteries typically measure charge remaining as a function of voltage or output resistance. Your battery is not a perfect voltage source. As it operates, the output voltage has some value that's not ideal. Your meter measures that non ideality. Degrading batteries generate the same effect so your phone doesn't know if the difference between a low battery and an old battery."
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7ezqwi | Why do certain foods taste bad when they are actually beneficial for us? | Why do certain foods taste bad when they are actually beneficial for us? I was just thinking because I poured some olive oil on my food and it tastes so bad, but I eat it anyway because I know it's good. Don't we suppose to crave things that are good for us? | Chemistry | explainlikeimfive | {
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"What is 'good' or 'bad' for us is often not determined by what it is but rather by how much. From an evolutionary perspective, we crave sugar and fats because this was the most difficult (and thus rare) thing to have, and at the same time, its the thing that contains most energy. Our bodies still 'believe' that this is the case, so we still crave sugar and fats despite its abundance. The science of what we should and shouldn't eat is a difficult one, and it doesn't help that every scientific finding or study is then bloated by mass media in articles like \"If you eat xy, you will live longer\" just because some rat experiment showed a marginal effect of a highly concentrated and chemically modified substance that also happens to be in xy. So you will probably find studies suggesting that eating oils in general is bad, and others stating that eating olive oil is better than eating palm fat, whilst others state that not oils but carbohydrates are the problem. Then there is taste, and that is often very individual. I for example like olive oil and could eat bread dipped into nothing but olive oil every day."
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7ezvl8 | - What exactly happens to our eyes when we look at the sun with our eyelids closed (like sunbathing) does the sun pierce through and damage them? | Other | explainlikeimfive | {
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"Your eyelids are really thin, it's like the top 2 layers of your skin thin (really thin). UV is pretty penetrative. That's why you get melanomas. The cells that turn into melanoma are like on the top of the second layer of your skin. When you look at the sun with your eyes closed, it acts like a cloudy filter that removes some of the light, but not all of it. Some of it still passes through and reflects off your eyelids which is why you can \"see your eyelids.\" That said, the UV can still pass through and damage your retinas, but to a lesser degree since you have something blocking it. UVB might be blocked by your skin, but UVA will likely go through and hit your retinas. That's bad. That said, you shouldn't be sunbathing at all. Get the daily requirement of sun and wear sunscreen, a hat and sunnies. Skin cancer risk is a very real thing."
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7f0dzx | how do shopping cart anti-theft wheel locks work? | Technology | explainlikeimfive | {
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"There is a braking device inside the wheels which contains a radio receiver. Around the boundary of the store grounds is a transmitter loop, much like an invisible dog fence, putting out a signal. When the cart crosses the invisible fence, it receives the signal from the transmitter and triggers the brakes inside the wheel, locking it up."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7f0hll | The Good Doctor, Whiskey as antiseptic | I was wondering if this would actually work in a pinch? Bonus if you can explain how alcohol kills the infection. | Biology | explainlikeimfive | {
"a_id": [
"dq8mf5y",
"dq8lvjx"
],
"text": [
"Yes, it does. A stronger alcohol (as some home-made distilled ones) would be more effective, but a 40% one still would work. This is a nice paper if you want to read on, Antiseptics and Disinfectants: Activity, Action, and Resistance URL_0 \"Generally, the antimicrobial activity of alcohols is significantly lower at concentrations below 50% and is optimal in the 60 to 90% range.\" It would kill some bacteria, but mostly it would allow to remove them from the surface (a wound, for instance). It works by denaturing proteins (\"unfolding\" them and causing them to lose their function) and by disturbing the membrane (like the \"skin\" of the microbial cell), as it is mostly formed by lipids.",
"Yes hard alcohols work as antiseptic. Alcohol is basically a poison, it is certainly poisonous to a wide variety of bacteria. Alcohols are almost all inherently acidic, and react with a lot of different substances. The react within bacteria and it kills them. Thats why rubbing/medical disinfectant is often just isopropyl alcohol"
],
"score": [
14,
8
],
"text_urls": [
[
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC88911/"
],
[]
]
} | [
"url"
] | [
"url"
] |
7f0m9u | Where is the information on how to fight viruses "stored" by the immune system, and why isn't this passed on to offspring? | Biology | explainlikeimfive | {
"a_id": [
"dq8mtxu"
],
"text": [
"It's antibodies present in the bloodstream. It's not stored with on your DNA in such a way it can be passed on. However, a mother will pass some antibodies to the unborn baby and through the milk for born babies."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7f0oy4 | What’s the big deal about monosodium glutamate? | What’s the big deal about monosodium glutamate? Help me understand. Thanks! | Biology | explainlikeimfive | {
"a_id": [
"dq8p9tu",
"dq8q19s",
"dq8nb93"
],
"text": [
"A little MSG makes food taste better; it's a \"flavour enhancer\". There are many foods that contain MSG, glutamine, glutamates, and similar chemicals (such as good parmesan cheese, beef stock, bonito flakes, etc) that naturally do the same thing. MSG is just a purified, powdered form. Many recipes and food traditions already contain a source of glutamic acid. Some people report headaches from MSG intake, although it does NOT hold up well to scientific scrutiny. Many such people seem to only have a reaction when they *think* there is MSG, not when there is actually MSG, so YMMV hard to test for at high doses since it has a distinctive taste, so \"blind\" taste testers identify the MSG and then are open to a placebo effect headache or other syptoms URL_0 In small amounts MSG additives are scientifically proven to increase palatability of tomato juice at concentrations of 0.2 to 0.8% In my opinion, skip the powdered MSG and go for food additives like an expensive cheese, beef demi-glace, soy sauce, or bonito flakes.",
"People had completely, falsely, and stupidly claimed MSG had some type of increased medical risk or caused medical issues in some people. This was an urban myth that got out of control. Its absolute nonsense that the collective world caught on to, but since has realized how stupid they were. MSG is nothing worse than other stuff. Its a \"flavor enhancer\" much in the same way salt would be used in a food to bring out flavor. If you go to cooking stuff or chefs, MSG is a cheap way to add a punch of flavor to a dish, and used pretty often, although again because of the above mystical negative press on it, you generally don't find it in supermarket foods you buy and such.",
"It's just another form of salt. Too much salt causes blood pressure issues. Like anything you need to keep it in moderation."
],
"score": [
11,
6,
5
],
"text_urls": [
[
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4870486/"
],
[],
[]
]
} | [
"url"
] | [
"url"
] |
7f0qi4 | If all of our respiratory action occurs in the upper chest with lungs and heart, why does our stomach being pressed on interfere with breathing/ why does our stomach inflate and contract as we breathe? | Biology | explainlikeimfive | {
"a_id": [
"dq8nndz",
"dq8r8w9"
],
"text": [
"Because you have a rib cage and your organs are squishy. Your lungs expand and trapped by your chest they expand downward. They push on your stomach which pushes through the gap in your rib cage. Pressing on your stomach limits where your organs can comfortable expand and thus stops your breathing.",
"> If all of our respiratory action occurs in the upper chest.... It doesn't. There is a muscle called the diaphragm across the bottom of the chest, above the stomach and liver. > The diaphragm is the main muscle of respiration and functions in breathing. During inhalation, the diaphragm contracts and moves in the [downwards] . In other words, the diaphragm's movement downwards creates a partial vacuum in the thoracic cavity, which forces the lungs to expand to fill the void, drawing air in the process. URL_0 To breath deeply and forcefully, like a singer needs to do for example, you should learn to use it more."
],
"score": [
9,
5
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Thoracic_diaphragm"
]
]
} | [
"url"
] | [
"url"
] |
|
7f10b6 | How does biting your cheek actually form an ulcer? | How does the ulcer itself form? Does the puncture wound become the ulcer somehow? | Biology | explainlikeimfive | {
"a_id": [
"dq8pwk4"
],
"text": [
"Basically bacteria in your mouth get into the cut and begin growing and feeding on your cheek. This causes pain and inflammation, which makes an ulcer. Your mouth is warm and moist, good growing conditions for bacteria, so they linger for ages compared to other infected cuts."
],
"score": [
6
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7f10rd | How does grass become milk after it has been processed by a cow? | Biology | explainlikeimfive | {
"a_id": [
"dq8rc29",
"dq8qvod"
],
"text": [
"The same way any mammal turns their food into milk. All female mammals produce milk for their babies. All female mammals produce milk using the same physiological mechanism. When the infant(s) are born the mother produces two hormones, prolactin & oxytocin, which signal the cells in the mammary tissue (breasts) to produce milk. The energy required by the mammary tissue cells to produce milk comes from digested food. The food that is digested depends on the animal. Cows eat mainly grass, humans eat a wide variety of foods, and lions eat mainly meat. All these different kinds of foods are digested and their components are absorbed by the body's cells for fuel & energy. The cells are then able to use this fuel and energy for a variety of means including the production of milk.",
"That's not really how it works at all. Grass to a cow is just food, so it eats the grass, and digests it, and takes nutrients and energy from the grass to function, turning them into proteins, fats, and other components. The difference between us an cows is that cows have 4 stomachs because grass is notoriously difficult for mammals to digest, so in their stomachs are a bunch of bacteria (we have this too, just not for grass) which help break down the grass into its useable molecules. Then when the cow has recently given birth, its body produces hormones, tiny molecules that float through the blood. These turn on all the milk producing processes, where proteins, fats, sugars, and other necessary components are mixed into water for the calf to drink. This is what we call raw milk"
],
"score": [
6,
6
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7f178e | Why is the US military low on money when it has more money than the next 8 countries combined? | Economics | explainlikeimfive | {
"a_id": [
"dq8rhmz",
"dq8s6rb",
"dq8rr53",
"dq9fpy1",
"dq8r3we"
],
"text": [
"> How is this happening when the US military has more money devoted to it than pretty much everything else on the entire planet? The US military probably *does* more things than any other military on the planet. Most militaries have a hard time operating outside their own country for any amount of time and doing so is difficult and resource intensive.",
"As the other posters mentioned, the US military is actively operating more than anyone else. We have fleets and bases being run all over the world. Training, pay, fuel, all have to be paid for just for existing. Likewise, we rarely consider the operational costs of our advanced weapons systems. Congress happily will spend trillions of dollars to build a state of the art fighter jets because it creates domestic jobs. But now you need to pay state of the art maintenance. You need to clean the gunk out of the engine intake to keep it flying mach 20. To get in there you need to take off stealth capable armored plating which means fresh paint, fancy screws and welding. The computers are capable of tracking hypersonic missiles, but run at 20 terahertz and can survive 20g barrel rolls. Now the soldering cracked and you need to replace the chips. Firing a bullet out the chain gun? Clean the barrel, make a new bullet. Operating costs are high, but boring, unsexy, and a hard sell to Congress because there aren't flashy lights to Ooo and Awe. Better and more expensive weapon systems can kill better, but usually also cost more to just keep operational while sitting in the closet. The US has lots of these systems.",
"Take a look at a budget breakdown of US Mil spending, and you can see where priorities are placed. About 60% of spending is on operations, maintenance, and personnel, another 10% is in R & D. After those big spending areas, everything else gets less than 1% of the budget. This means that things like the 7th Fleet badly needing upgrades and additional services that are beyond the scope of normal maintenance are way below the red flag area that makes them mission critical. Other nation's militaries tend to spend more keeping their equipment up to date, more on personnel, more on general quality of life for servicemen, and much less on R & D, operations (especially), and maintenance.",
"Gotta spend this year's entire budget to make sure you get at least the same amount next year",
"Because the us govt commits their units to about 7000 different projects at once....whether they have money or manpower to support said projects"
],
"score": [
60,
20,
8,
7,
7
],
"text_urls": [
[],
[],
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7f1fmo | The economics of the Macy's Thanksgiving parade? | Economics | explainlikeimfive | {
"a_id": [
"dq8w919",
"dq8t7uh"
],
"text": [
"URL_0 Macy's organizes it with about 4000 employees, but it involves about 10k. Each spot in the parade costs money. $190k for a new balloon, $90k for a returning balloon. Floats can cost $780k to $2.6 million, paid for by the people wanting it in. I believe the only ones who don't pay to get in are marching bands- they only allow 12 each year though.",
"It's all about the advertising. Every organization involved pays for their spot, and once the parade started being televised the price of those spots only increased. Each organization pays for whoever is involved in their display and organizes their own things themselves."
],
"score": [
6,
5
],
"text_urls": [
[
"https://www.cbsnews.com/news/thanksgiving-day-parade-float-costs/"
],
[]
]
} | [
"url"
] | [
"url"
] |
|
7f1mzq | Why does cold metal feel wet? | Chemistry | explainlikeimfive | {
"a_id": [
"dq8vy1e"
],
"text": [
"The feeling of \"wetness\" isn't actually a sense, but more of a combination of senses. If you've ever touches water through gloves, your hand feels like it's wet, but you're not actually getting any water on you. This is because, even though you have gloves on, it's a combined triggering of your cold thermoreceptors and various mechanoreceptors that contribute to the perception of wetness, and these can be felt through the gloves. The same is true for the metal."
],
"score": [
9
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7f1nx2 | Why is magnetic force perpendicular to the motion of an electric charge and the magnetic field? | We've recently been taught that a moving charge, no matter what, will always experience a magnetic force which is perpendicular to both the motion (velocity) and the magnetic field. I'm having trouble understanding this since I can't think of a 'real example'. I mean, if I moved a powered wire near a magnet, it wouldn't start circling around it, would it? I can't wrap my head around this! | Physics | explainlikeimfive | {
"a_id": [
"dq8uj91"
],
"text": [
"> I'm having trouble understanding this since I can't think of a 'real example'. I mean, if I moved a powered wire near a magnet, it wouldn't start circling around it, would it? [Actually, yeah it would.]( URL_0 ) A very simple electric motor can be constructed that way."
],
"score": [
4
],
"text_urls": [
[
"https://youtu.be/94RpbYopUdI"
]
]
} | [
"url"
] | [
"url"
] |
7f1puo | Where does the average human height (say 170cm) fit on the cosmic scale from the smallest known piece of matter to the largest known distance? | Physics | explainlikeimfive | {
"a_id": [
"dq8vpw6",
"dq8xs6x"
],
"text": [
"Planck length is roughly 10^-35, distances smaller than this are not described usefully by modern physics. The diameter of the observable universe is roughly 10^26. However this value is constantly changing so it's less fundamental than the planck length. Still, your height is about 26 orders of magnitude smaller than the largest distance, and 35 orders of magnitude larger than the smallest distance.",
"The halfway point is about a grain of sand. So closer to the larger one, but not by a whole lot."
],
"score": [
9,
3
],
"text_urls": [
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7f1w31 | how did presidential elections work before the technology existed to communicate across the country? | Today we just tune into the news or surf the internet and we we're exposed to the candidates and we make our decision that way, but how did this work before radio communication was invented? | Other | explainlikeimfive | {
"a_id": [
"dq8wmd8"
],
"text": [
"In the US, this is one of the reasons why the electorial college exists. Instead of trying to consolidate polling results on a national scale, each state was split into districts. Each district tallied up their votes, and (for most states using winner-takes-all) sent their allotted amount of electors, and they are pledged (but not necessarily obligated) to vote for the candidate that won the popular vote in that state. The electorial college votes a while after the general election. As for the results, they communicated the long way, by person or mail, to the general public."
],
"score": [
12
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
7f1wsj | The long term effects of blasting music with earphones/headphones | Biology | explainlikeimfive | {
"a_id": [
"dq8zgzc",
"dq9k0bx",
"dq8wwe3"
],
"text": [
"It's neither cells nor the eardrum but in fact the cilia that are damaged by high sound pressure levels. These are hair like structures within the cochlea that detect the waves of sound through the inner ear. Once they break they can no longer detect the frequency that they are attuned to (bit of a simplification there). Keep your levels low guys, you'll miss your cillia when they're gone.",
"Imagine all the little sound detecting hairs like a huge forest of trees. Really loud sounds are like a violent storm, which knocks down the trees. These trees never grow back. As there are less and less of them to detect sound it becomes harder and harder to hear.",
"The highly sensitive cells used for hearing become overly stimulated. This damages them, resulting in hearing problems. continuing to do so kills the cells, and causes hearing loss completely."
],
"score": [
57,
12,
7
],
"text_urls": [
[],
[],
[]
]
} | [
"url"
] | [
"url"
] |
|
7f1zet | Why does heat speed up chemical reactions but lower efficiency of electronics such as solar panels? | Other | explainlikeimfive | {
"a_id": [
"dq8xj63"
],
"text": [
"Heat doesn't speed up chemical reactions. It speeds up endothermic reactions. Le chateliers principle states that a system will always oppose a change. Adding heat to a reaction that produces heat will slow it down, adding heat to one that sucks heat will speed it up. Electronics produce heat when they operate, adding more heat is bad for them. While solar panels are a pseudo chemical thing (with semi-conductors) most other electronics perform worse with heat due to the actual material expansion of their components, not to mention the possibility of melting."
],
"score": [
3
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7f229f | Why are processed foods bad? | Biology | explainlikeimfive | {
"a_id": [
"dq8xf93"
],
"text": [
"There are many different ways to process food and I would hardly say that processed food is necessarily bad, however, when food is processed it is usually for the purpose of making it easier to ship and to store, and seldom for the purpose of making it more nutritious. Nutrition and flavor are often sacrificed."
],
"score": [
7
],
"text_urls": [
[]
]
} | [
"url"
] | [
"url"
] |
|
7f2m2t | How can we prove every integer except 1 and 2 can be "a" in the formula a^2+b^2=c^2? | I made a program to find these right angled traingles and noticed every positive integer can be a side length except 1 and 2, is there any sort of proof for this? | Mathematics | explainlikeimfive | {
"a_id": [
"dq92xts",
"dq9opuj"
],
"text": [
"First we'll note that we only need to worry about prime numbers. All the non-primes can be dealt with by scaling up the triangle for one of their prime factors. For example, we can get a side length of 12 by scaling up (3,4,5) to (12,16,20). If we pick any two integers *m* > *n* > 0, then we can prove that there's a right angled triangle with the sides *a* = *m*^(2) & minus;*n*^(2) *b* = 2*mn* *c* = *m*^(2)+*n*^(2). So now we need to show that all odd primes can be expressed as *m*^(2) & minus;*n*^(2) for some integers *m* and *n*. For a prime *p*, we can do this by taking *m*=(*p*+1)/2 and *n*=(*p* & minus;1)/2.",
"3Blue1Brown, a fantastic youtube channel has made a video before regarding something like this. It had more to do with finding all possible \"pythagorean triplets,\" meaning 3 numbers you can plug in \"a^2+b^2=c^2\" and have c be an integer. The 3,4,5 triangle being an example. I recommend checking it out! Edit: I'm not sure if this is what you're looking for, but it's worth checking out in my opinion. Link: URL_0"
],
"score": [
6,
3
],
"text_urls": [
[],
[
"https://youtu.be/QJYmyhnaaek"
]
]
} | [
"url"
] | [
"url"
] |
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