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3u4xya | how come mcdonalds salad dressing are from a brand name and the company doesnt make its own generic version? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3u4xya/eli5_how_come_mcdonalds_salad_dressing_are_from_a/ | {
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"If it ain't broke, don't fix it.\n\nAlso, brand recognition/cross branding. People might be more willing to try the salad if they know they already like the dressing brand.",
"In business, this is known as a \"make or buy\" decision, and they're very common. A team of people will analyze every aspect of either manufacturing your own item, or buying it from another company. \n\nEventually, a decision is made. In this case, its likely that McDonald's felt that it would be cheaper to buy dressing, and that brand recognition would help sales."
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8v9m6t | how does salt improve plant growth? | I do know that salts used in moderation can improve plant growth. However, all I could find by googling is explanations on how an excessive concentration of salts hinder plant growth. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8v9m6t/eli5_how_does_salt_improve_plant_growth/ | {
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"Salt, as in table salt (sodium chloride) is not good for plants as it draws water away from them. However, minerals that help plant growth can come in the form of mineral salts, like epsom salt (magnesium sulfate). So really, it all depends what type if 'salt' you add to the soil"
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9dy13s | why is bluetooth so much less reliable than rf? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9dy13s/eli5_why_is_bluetooth_so_much_less_reliable_than/ | {
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"What exactly do you refers to as RF devices? Is it Radio Frequency? \n\nIf that is the case Bluetooth would be included as it is a Radio Communication. ",
"Think about Bluetooth vs Wifi. Wifi seems really strong and will travel though walls while Bluetooth loses connection in as little as 5 feet away through empty space. Both are Radio Frequencies, which are just waves. \n\nThe real difference is power. You could send information across a pond by throwing rocks into the water with different time intervals between each stone to carry information. A person at the other side of the pond with a watch could write down how many seconds elapsed between each wave observed. Think of bluetooth as tiny pebbles being thrown into the water. Think of Wifi as giant rocks being thrown into the water. If the person on the other side of the pond is too far away, they might not see all of the waves made by the tiny pebbles. They would probably not miss the waves generated by giant rocks. The issue is try throwing giant rocks into the water for hours on end. You will run out of energy. Your bluetooth mouse/ headset might only last a few minutes blasting out wifi waves but they could operate for days using bluetooth. "
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1bat5m | how do people take either chunks, or clips, or whole tv episodes from a show and are able to put it on a player like youtube or something? | You can always find a clip from a show, or even just a certain sketch from a whole episode. (I.e.: wkuk.) So I'm just curious as to how it's done | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1bat5m/eli5_how_do_people_take_either_chunks_or_clips_or/ | {
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"They download the show from something like 1channel or piratebay and edit out everything but the clip in a video editing program like Windows Movie Maker."
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4ucm3x | - why do cars have a button to switch off traction control.. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ucm3x/eli5_why_do_cars_have_a_button_to_switch_off/ | {
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"Because there are certain situations like being stuck in the mud, snow, or sand where traction control hinders the process. "
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2g4zxb | when i sneeze sometimes my muscles around my crotch tense so much it hurts. | Why does this happen? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2g4zxb/eli5_when_i_sneeze_sometimes_my_muscles_around_my/ | {
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"Sneezing is a reflexive response that requires the coordinated contraction of many muscles in your body all at once to push air through your mouth/nose much faster than normally possible.\n\nThe actual pushing of air happens in your chest cavity. When the muscles contract, it builds up a huge amount of pressure that pushes the air out of the lungs. However, that pressure in your chest/abdomen can possibly push other places besides your lungs.\n\nAn increase of pressure in your abdomen can cause hernias which are when a organ are pushed outside from the cavity they're supposed to be in! The muscles in your groin contract during a sneeze because they are preventing the guts above from being squeezed out.\n\nThey may remain tense after sneezing sometimes because they never got the signal to stop being tense. This is similar to the feeling you get when you are nearly about to sneeze but don't, causing tensing of some of the muscles required for a sneeze but not all of them."
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6ymd12 | how do fbi track down anonymous posters on 4chan? | Reading the wikpedia page for [4chan](_URL_0_), I hear about cases where the FBI identified the users who downloaded child pornography or posted death threats. How are the FBI able to find these people if everything is anonymous. And does that mean that technically, nothing on 4chan is really truly "anonymous"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6ymd12/eli5how_do_fbi_track_down_anonymous_posters_on/ | {
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"Your IP is recorded when you post on 4chan and attached to the post, but not shown. Moderators and the admin have access to it. Though the more common use is to identify rampant shitposters, when something illegal or a credible threat is posted they generally contact law enforcement, or law enforcement contacts them and they pony up the IP.",
"In some cases, wesbites like Reddit give law enforcement a user's IP if it's relevant for criminal cases. But even if that is not possible, there are means to track users.\n\nFor example, it's possible to link a user on 4Chan to his other activities on the internet through his style of writing and interests. This way, they might identify someone who posts childporn anonymously on 4Chan as a Reddit user with a prolific posting history, which might shed light on personal information. They might even find his Facebook account with his real name, all through data that the person posts publicly on the internet.\n\nThere are also some more shady techniques, like a correlation attack. What that means is that they monitor outgoing traffic of an internet user and compare that to the posts on 4Chan. So if an anonymous guy posts an image with a size of X at time Y and the suspect has outgoing traffic of size X at time Y, they've got a match. This might be sheer coincidence the first time it happens, but if it happens several times in a row, it's enough for a court order. This is how they got a guy who [issued a bomb threat through TOR](_URL_0_).\n\nEdit: Better link",
"Most people have absolutely no idea about how much personal data they are willingly giving to the web services companies (besides the data that are unknowingly given or the 'digital footprint') that they can share and how much those companies track them. FBI can get that data from those companies easily. ",
"Nothing is ever really anonymous on the internet. Everything you do has your IP attached to it in some way. The FBI can easily obtain a subpoena that requires a website to release their records for investigation, under threat of legal punishment if they don't. Same process for cell phone records. ",
"The Chan sites are only anonymous in the sense that anyone can post anything without having to make an account or provide a name, they are not anonymous in the commonly misconceived form of hiding ones identity and being completely free of digital-trails. Every time you post on a Chan site your IP is recorded (its hidden to public but clear to admins), thus if you post something forbidden they can then report the post and share your IP to authorities. Hackers have also been able to 'see' posters IP addresses on 4chan in the past and have used this for both good and evil, for example when annon was posted up images of an actual freshly murdered body, some batman-esk hackers managed to track down the up-loaders location just from the IP activities. \n\nIn short; you are never truly anonymous. ",
"Nothing is actually anonymous on the internet...\n\nYour best bet is to use public Wi-Fi with a burner laptop that you purchased with cash. ",
"I'd decribe the two main ways as,\n\n1. User error. The user makes no attempts to cover their tracks. Everything you do online essentially leaves a footprint, your PC itself has several identifiers, the connection routes you use have identifiers, etc. Imagine robbing someone's house when there's thick snow. All they have to do is follow the footprints and they've found your house with the stolen TV inside.\n\n2. Connecting the dots. Even if the user has made substantial attempts to cover their tracks, they used a common alias that they've used many times. So they know the user FuckNut12 posted CP. They do a general search for FuckNut12 and find a hotmail address with that name, which is also used on Reddit, Youtube and a few forums. Through court orders they can obtain personal information that relates to that username, and then once they have name, address and other identifiers, they can then get a warrant to search that persons PC. On which they find the evidence linking to the 4Chan post. \n\nA mix of the two is also used, connecting usernames to different sites, gathering IP information based on connections, getting the relevant information from ISP's, VPN providers and the like. \n\nMostly it's down to the user. If you take every single measure possible, you probably won't ever be found. But due to human nature we often unintentionally leave clues and traces due to our reliance on familiarity or memory recall. I believe the Silk Road guy was caught through a series of posts he'd made well before he founded Silk Road for example. \n\n",
"You are not as anonymous as you think. Something that seems innocuous, such as the size of the WINDOW you browse a website with, can be used to uniquely identify and track you.\n\n_URL_0_",
"what if there was mock site that made a viewer automatically download unwanted photos? is that an alarm to the fbi ?",
"I'm going to be that guy here, but the correct term is child abusive images. Pornography suggests something else altogether. \n\n_URL_0_ scroll down and there's an explanation. ",
"there are technologies that analyze traffic in near real time and at the same time comparing it to months of history, that makes it very easy to find someone - as /u/Fauler_Lentz says, there are patterns that are hard to avoid making. \n\nIt has become extremely hard to stay anonymous on the internet to the point where you might as well not try.",
" You are never truly 'anonymous'...your ISP will sell you out for as little as an oreo cookie...\n",
"1. Supposedly 4chan cooperates closely with law enforcement, to the point that they cache a second copy of the site for leo review, or give le unabridged realtime access to the site. A theory is that 4 Chan is basically a honey pot at this point. Though I've never heard of any one getting in trouble for downloading things from 4chan, only uploading. \n\n2. Nothing on 4chan is truley anonymous, just as nothing is truly anonymous on the internet as a whole. ",
"Mods are required to report the IP of posters when something illegal is posted. That's why you don't mess with football ",
"[This](_URL_0_) is a very good talk about finding people on your ( what 4chan usually uses for hiding)",
"Logs are kept. These logs show detailed information about anyone connecting to a website. Your ISP also has logs of every connection you establish. These logs can go back years. \n\nOn a side note... it's shockingly easy to get some of these companies to release information. I've seen some major websites release information when they get a letter with some law firm or police department letterhead on it. You don't necessarily need a warrant due to the laws. ",
"Well, don´t post a picture which you captured with your smartphone with GPS-location turned on (which is standard activated on Android).\n\nThey got over 100 drug sellers like this.",
"How much does using a VPN help?",
"OP asking for a friend?",
"With the counterfeit couponing guy, he had [used another forum](_URL_0_) to direct users to the 4chan post. The admins of the other forum gave him up. It didn't help that he quickly confessed.\n\nAlso, the FBI monitors 4chan, and almost definitely archives posts as they happen.\n\n > In mid-March, when an agent sought a search warrant for Henderson’s Rochester apartment, the investigator indicated that federal probers had been keeping an eye on 4chan. Agent Barry Couch referred to “FBI agents’ observation of posting activity on the 4chan Website.”",
"Nobody is trully anonymous. Even hackers that use proxy can, in theory, be tracked back. But most of 4chan do not use any proxy at all.\n\nNot quite ELI5 but should be easy to follow.\n\nFor administrative purpose the forum store the poster IP address.\n\nThe web server also have a log with every ip address with a timestamp and what they did, the formay might be like \"ip-address 2016-09-07 13:21:32.1234 get URL errcode filesize\" and in some country the hoster might be required by law to keep the logs.\n\nThen you have the internet provider for the hoster that in most country they are required to keep the logs (which do not contain the data but just the header and size (think of the postal service that would take a picture of the labels and physical size). There is some intermediate provider that is most likelly also required to keep the same logs, and finally the user's provider that also keep those logs.\n\nThe police can ask for a warrant to get the information from the forum owner, if he do not have the logs then they will ask the web hosting compagny. Then they find the ip address of the client, ask for a warrant for the client's isp, which give them the account owner and address.\n\nFor those that hide behind a VPN, it get more complicated mainly due to the fact that it is around the world and international cooperation is complicated and require quite more effort.\n\nThey get the forum owner info, notice it is a vpn, request info from vpn, but they don't have logs because they are in a country that don't mandate it. request web hosting isp logs then vpn hosting compagny logs and then match the packets flow... Once they matched it, they can check the VPN data which other connection had the same packet pattern: what came out of the vpn had to come in from somewhere. Then, with the timestamp and packet size and other information, they can be pretty sure out of any resonable doubt that the outgoing connection came from THAT incomming connection at the VPN end. They now have the true client ip info. Get the warrant for that client isp, and they get the account holder. Repeat if required. It take time, LOTS of effort, and some country have ridiculous short time for the logs. I beleive canada and usa is 6 months, but some under defelopped part of the world have zero log, and some refuse to cooperate together. I know that some place in africa is 2 weeks data retention.\n\nBTW, here is one of my apache log line: 192.168.2.23 - - [28/Apr/2017:09:34:30 -0400] \"GET /public/serveur/20170427_160015_HDR.jpg HTTP/1.1\" 200 4289991\nhttp/1.1 is the protocol used, 200 is the status code, in this case a \"ok\" message, while 4289991 is the file size. I beleive that instead of http/1.1 if someone post an image it would say \"POST\" instead of \"GET\", which as you can guess make thing easy to search for: \"search log for this filename, find the line containing POST\"\n\nAs for TOR (read edit bellow), the same can be applied: match the victim log to the tor exit log, match the outgoing packet to the incomming packet (which can be a small issue as there will be a size mismatch, but the timestam should match withim a few ms and the size will be simmilar), repeat until you hit the entry tor server, match with the client ip, figure out that there is no other connection that match, thru being trully that one. Now you found the originating account holder. The issue with tor is the complexity of working internationally, and the fact that each step get harder to convince a judge that the data is still valid and no error has been made.\n\nEDIT: For Tor, this is an extremelly over simplified explanation. But the main issue is that it is too much of a trouble to get enought proof and follow the communication that they do not do it. Packet maching of encrypted data is a royal pain to do, and the fact that the nodes are overloaded cause a royal headache. Plus the chance of error is so high that it would not hold in court. And at the end they still can't know what was transfered unless the endpoint is in the clearnet. If the endpoint is on Tor then good luck. One of the issue is that you do not know really where the hidden server is in the world. Even if you do know you can't know what exactly got transfered. Those server will most likelly not have any usable log, usually the actual logs will reside in ram only, so if the police seize the server then all the log goes poof. Meaning that they will most likelly not be able to track back anything. What they did to catch some is to install some virus/hack on the page and run the server for a while and hope that the person catch the virus and the virus will expose them. Or they just read everything and try to match the info collected with some other piece of info and close down that way on some suspect.",
"Just yesterday I read [this article](_URL_0_) about Brian Krebs researching the history of Mark Hutchins (malwaretech). He goes into detail how he connected a number of dots.\n\nNow imagine this, but with the resources of an entire department of people able to access much more information that Krebs had available.",
"There's a really good Defcon talk that explains exactly this: _URL_0_\n\nTalks about a lot of the cases mentioned in this thread, like how they got Lulzsec, that harvard student, silkroad guy, etc",
"Every image making a trip between a user and a server has its unique hash code stored somewhere, intentionally or not.",
"4chan is NOT anonymous. 4chan \"chooses\" to capture your IP address (which is basically the physical address to the spot where you are accessing the internet) when you log in (i.e. they have programmed the site to capture and store your IP address when you log in). Most (if not all) ISPs (the company you pay to access the internet) log your IP address as well. With the new H. Res 230 bill passed this year by congress, your ISP can now sell your browsing history to anyone that pays for it.",
"use a vpn service. that you paid for with bitcoin. from a public wifi. and a randomly generated username that you then throw away. (_URL_0_)\nand two finger type (unless you usually do, then go one finger or whatever is different from \"normal\"). and use search and replace to change or delete articles (\"a\", \"the\") and other similar things to help mask your dialect/accent/ethnic origin. and write whatever you write offline and post it copy/pasta to mask typing speed, etc. ",
"The FBI also keeps any images they find of child pornography for several reasons. \n\nFirst it is to investigate the background in the image to try to find where it was taken and who might be responsible. \n\nSecond is to use the images to find other people collecting/sharing child pornography. Almost like a reverse image search. \n\nThis means that the largest collection of child pornography is owned by the government.",
"4CHan and others record your IP when you post. You're anonymous to other users, but not the the webhost. The information can be passed on to authorities. \n\n Usually the main mistake people made though if they've made some effort to cover their tracks through Tor or other services is to give out too much identifying information- that may be hardware information or personal- like using a similar username or mentioning things about their physical location or self. The authorities then use that to track you down.\n\nTor can also be 'broken' because it uses a series of nodes to disguise traffic from end to end. What happens when the authorities have control of each node in the chain, and even the endpoint? They can directly correlate the traffic at one end to the other. Then they call up your ISP for your details and then they're at your door.",
"[But there are 23 Douglas Jones's in metropolitan area, how are we going to find the right one?](_URL_0_)",
"I don't understand how people could possibly think they're anonymous online no matter the site. **Every site is required to keep log files containing your ip for legal purposes.** Some can even go further and collect browser addons and settings, and even your window size if they deem it necessary. Some sites collect this information to improve their sites. Others will collect it to alleviate authority pressure if the need arises. It's just what it is, and there's no law that says you have to provide information on all of these things like there is for cookie usage now.\n\nYou're not anonymous from using Tor either. Hell, you're not even anonymous by using Tails. I recall a cyber security expert from Russia mentioning ISPs are using heavy-handed laws in the US for more than just greed; they're using it for control. If you even download Tor or a security software, your ip is put on a list by your ISP. If these net neutrality rules get axed, it will mean way more than simply price-gouging you for service packages. It will mean them being able to issue new legislation requiring smaller bits of information under the guise of service improvements. And, much like cookies, these will have lots of nuances that won't be codified in law.\n\nThat second part is always glossed over by people here and that's a shame. We need to consider implications further than simple price-gouging. If anything that's the battle the monoliths would want to fight, not a battle on grounds of the sneaky stuff. In fact I don't recall ever seeing a post about net neutrality focusing on anything *but* price-gouging. Makes me wonder sometimes.",
"A couple of things to note here;\n\n* Since 2008, Christopher \"Moot\" Poole, the founder of 4chan has been cooperating with the FBI and Governmental Agencies allowing them access to the IP-Addresses of posters when needed. He also famously appeared before a Court to describe the nature of this sort of IP-Address tracking and how it could be used to identify an individual. He is no longer incharge of 4chan but I'm assuming this policy hasn't changed much.\n\n* Since 2009, The FBI and/or other agencies have been running \"Honeycombing\" operations on sites like 4chan and other Chan boards, including the Famous TORChan which was in the onion web. In these Honeycombing operations, they will post a \"Bait\" image of either CP or other illegal activities (including drugs and what not) with a post asking them to follow a link to an external site. This site is under the full control of the involved agency and they then use it to try and coerce personal information from the person involved and try and pin them for conspiracy or intent.\n\n* Since 2011, 4chan has kept detailed backlogs going a number of months of posts / threads on all boards. These logs are used to perform lookups for certain patterns when they need to identify a single individual. Things like typing pattern recognition. This can then be used to create a profile of the person which can then be cross referenced to other sources to try and identify an individual.\n\n* A lot of people posting images online don't realize that the images contain metadata. Most mobile phones will encode the exact location that the image was taken at (Lat / Long), if you don't scrub this metadata it is very easy to identify you. I think 4chan now automatically removes metadata from posted images but for a long time inexperienced posters were caught and publicly doxxed using this technique.",
"Besides all of the very technical ways of doing it, it's not very hard to dox almost anyone on the internet. If someone does anything of interest, they likely have a lot of activity (i.e. Child porn) or they have little activity but it's very specific (i.e. Bomb threat). If 4chan can dox two guys torturing a cat (by scrawling Facebook and comparing pictures to the video) in a matter of hours (? maybe days, I forget now), imagine what a huge bureau of highly resources (and with legal force), highly paid, highly educated, highly motivated, highly etc. can do.",
"Just the way you write is a signature. \n\nAt some point there'll be anonymizing rewriting filters that screen out individual signatures and the lot. Controlled vocabularies and the like.",
"Anonymity on 4chan simply refers to having no user names. It's no more anonymous than any other site in terms of identifying people.",
"In addition to all the information here about ips being stored in server logs and attached to posts, every request we make is being watched and logged by probably several agencies.\n\nWhen you view a webpage, your browser makes a request for that page. This is intercepted and logged by your isp and by government programs such as PRISM. Each image, etc... in that page is another request, which is logged.\n\nData at this scale generally works by aggregating (or making lists of) simple information. So if there's an illegal image anywhere, you can be pretty sure that it has been identified by it's url and added to a list. Then, when anyone requests this image, you are \"added to a list\" of having viewed this information.\n\nUltimately, at least one commercial entity (your isp) and an unknown number of government agencies has a complete record of everything you've done online for many years now. I predict these records will be used in dramatic ways in the coming years.",
"Asking for a friend right? ",
"Any motivated government or law enforcement agency is capable of tracking you down on 4chan. Don't post stupid shit on the internet and your chance of getting arrested drops significantly. ",
"Long story short: every web server in the western world is required to store some data *about* data. If you post on any forum, including 4chan, your IP address is stored.\n\nSo: fetch IP address from 4chan with warrant, fetch account data from Internet Service Providers with warrant and find the IP address in it, and voilà: your house address is uncovered.\n\nThis does not mean it's you per se: if seven people live in that house, no one can be accused just like that. But checking the local data storage will tell what computers accessed 4chan, and eventually which device posted the death threat or downloaded some Caesar Panini, if you catch my drift. Doesn't take long to find out who the laptop belongs to when you threaten the whole house with jail time; much less if it contains personal data (bank details; Skype account; you name it).\n\nNothing is truly anonymous if there's time to follow the bread crumbs. ",
"My ELI5 version:\nEvery computer on the INTERNET has an address. People can try to hide their address, but the Police can make companies tell them what addresses have visited their site and what they did why they were there.",
"Note that 4chan does not accept or permit Child Pornography and pulls it down as soon as they see it. There may be some leeway on the whole cartoon images of children thing (which is also considered CP in some jurisdictions), because no child was actually hurt or used in the production of that, but if you're posting porn photos of real underaged girls or boys on a forum, it is going down and you're getting banned as soon as a mod or admin sees it.\n\nWhile they may tell the cops to fuck off if they wanted your IP for posting something political or other forms of speech, I don't think they make any bones about running your ass in for CP. They may not call the cops themselves, but they will hardly stand up for a pedo in that situation if they are posting that crap. \n\nExpect that 4chan will cooperate with the law if you post that crap and may even be working with the law to nail you if you do. \n\n\n",
"How about you don't download child pornography or make death threats?",
"Well, it depends on a lot of things, basically the what, how, when of their post. \n\nIf they are not using any techniques such as a VPN or TOR, then it is trivial for law enforcement to catch them. \n\nWhenever computers talk to each other on the internet, they need to know each others source and destination IP addresses, which basically work like phone numbers, So, if someone posts something illegal, there will be a source ip associated with the user. Law enforcement can then phone up the internet service provider and they will know what customer the address corresponds to. \n\nNow, let's suppose they are using tor/vpn. The idea with those is that you pivot through another machine so that it obfuscates your true ip address. This makes it slightly harder for law enforcement, but they can be tracked through a number of ways such as:\n\nEach web browser has slightly different settings, version, add-ons, and other variations which make them unique enough to act like an online fingerprint. So depending on the circumstances, and what intel they have, they can just do the standard detective's game of cross referencing against suspects. \n\nThe next way is how some anon a few years ago got caught for threats about going postal with pipe bombs at school. He took a photograph of his pipe bombs and guns etc, using his dad's camera. He probably should have looked at the EXIF data before he uploaded because his dads camera automatically embeded something personally identifiable (was like family business name or address) and so he got arrested less than a day after his post. Smartphones (and some DSLRs) can even embed gps data. \n\nDepending on how high value the target is for law enforcement, they use tailored access operations, which basically translates into finding a way to hack into the target. Usually with cooperation from ISPs, cell phone companies etc. and just get malware into their pc so they can gather evidence. \n\nAlso, the biggest way people get caught with internet crimes is why people get caught with any crime. They get sloppy, they get overconfident, they think they are like some criminal mastermind whose untouchable but really fail to see all the different ways they can get caught,\n\nThe thing about the term 'anonymous' is that its not really a thing with forensics. Everything you do leaves a trace, and as long as the trace exists, eventually it can be connected to you. 'Anonymous' just means traces that don't yet have a name attached to them.",
"When you are on the internet, whenever you send or receive information, it comes and goes to and from you in this little bytes called packets. In these packets are very important data, such as your IP address and MAC address. Your IP addressed can be changed via a VPN, but your MAC address (for the most part) cannot. Your MAC address is unique, there is no other device in the world that has the same MAC address that you do. \n\nISPs use the MAC address on your modem/router to give you internet service. So, when you post some wild shit on 4chan and the FBI wants to find you, they get the IP address, contact ISPs and boom, you're raided and questioned for that Pepe meme you keep sharing.\n\nThat is why in the show Mr Robot, you see the main character constantly cooking parts of his computer in the microwave. He's hooking his network cards. The only way to TRULY mask yourself online is to constantly burn network cards. Network cards are cheap, so it's not a terrible idea.",
"related: defcon22 how tor users got caught \n_URL_0_\n\nprobably a little bit technically advanced but still quite interesting. \n\nMoral of the story, if you do bad things, there's always ways it can come back to get you ",
"I think people greatly underestimate the tracking prowess of the feds. \n\n_URL_0_\n\nThat was the 90's. \n\nIf you collect enough of the backbone traffic and make it searchable, it's not a far reach from nailing people (encrypted or not) by traffic patterns. TOR had the right idea, but even they've proven to be questionable. ",
"When you post there is an IP logged. Christopher \"poole\" moot never had an issue working with authorities. Posts IP's were saved for a period of time (30 days?) after the post - Chris forwarded those to the FBI / authorities when requested. ",
"most forums track EVERYTHING you do. They do it to show advertisers who their viewers are, and how to best advertise on their websites. \n\n\nReddit makes money from advertising, selling your information is how they make their money.",
"Most replies are lazy. \n \nWhen you visit a site, the site usually tracks your IP and timestamp. \n \nAlthough you don't need to register an email, this is all logged to report to the FBI when needed, because otherwise their domain gets seized for noncompliance. \n \nSimilar to lavamail's issue, they shutdown rather than comply with some requested. \n \nSo the gov has more access to the providers, even webhosts ( I've worked for both ), to comply with even more info, all to track back to a physical location and a timestamp. \n \nRemember silkroad's dread pirate robert? He got busted using a library wifi. \n \nThey can't trace every post back to a person, but they can follow it back and if the user continues to post, even over time, they can piece it all together. \n \nEventually, someone messes up and either posts from home or in a pattern that lets them narrow it down to a number of actual names then watch, or they have enough to point to one person and just arrest. It's a lot of leg work because it's not a live stream and you're usually auditing logs of multiple entities trying to piece it together. ",
"4chan is only anonymous to the end users. Mods can see IPs, probably Jannys too.\n\nIPs are definitely tracked and unless you are using a 4chan pass (which makes you identifiable by payment info), so are things like TOR, Proxies and VPNs.\n",
"well you see everyone's computer has an address, many programs record that address and or send it to other computers that record and grant access to information(parcels). Those parcels are stored on other computers. Those addresses have to be sorted, and parcels as well to send that information to the proper place much like how the U.S. postal service works only light years faster. If you want to see where a parcel was sent from you can go to the computer that received the request and look up the \"IP\" address that originally requested it. Pretty simple when you spell it out but actually knowing how to and finding it now that's where the hard part comes in.",
"4chan is only anonymous in the sense that there are no usernames. The connection between 4chan and the user is not anonymous.",
"The best thing to do is buy a laptop from someone with cash, or steal a laptop. Boot from flash drive and use Starbucks or Mcdonalds free WiFi from a stolen car or have some way to disguise your identity if you go inside. Use free vpn or trash laptop after use.\n\nSend package to random house but don't use the actual home owners name, use fake name. If the home owner is present when the package is delivered you say you live nearby and accidentally sent package to wrong address, otherwise just swipe package when it's delivered. Make sure home owner doesn't have cameras outside front door. Don't use trailer parks or apartment building, those people don't have jobs and will be home when your package is delivered. ",
"TLDR: on the internet, nobody knows that you are a dog. Except if you download puppy porn, then FBI and NSA will sooner or later find you which dog you are.",
"*chan websites are end-user anonymous, and that's where it ends.\n\nAdmins and mods can see IP addresses, ban and post history associated with any IP. Post history is a little bit more limited though. I believe staff can also archive posts for evidence, end-users don't see this either, but it retains stuff for evidence.\n\nAnd this has been the case since the start. Anyone who ever thought any chan was anonymous is a dipshit. ",
"ELI5 version, assuming you understand how regular postage mail works:\n\nTo be connected to the internet you need an IP (internet protocol) address. This is like a mailing address, it tells other machines on the internet how to send you information. For example, if you're playing the latest video game with a friend, you need to know his IP address so you can send him data packets such as 'my character just moved through the door' or 'I just picked up a new shotgun'. \n\nThere is one organization that hands out IP addresses to make sure no one gets the same one. From you can tell who owns an IP address. You as an individual user are unlikely to have your own. What's more common is that your internet service provider (ISP) buys a bunch. They make have 10,000 customers but know that only 2000 are online at any given time so they buy 5000 to be safe. Then when you need one they assign it to you.\n\nNow to 4Chan. When someone posts there the 4Chan server receives their data. It also logs the IP address of the person who sent that data. It logs is for many valid reasons, for example say there's a lot of spam that comes from Nigeria the 4Chan server may want to block all data coming from Nigerian IP addresses.\n\nSo lets say the police want to know who posted a message. They contact the owners of 4Chan servers and say \"We have a warrant, what was the IP address of the person who posted this particular message?\", then the police looks up who owns the IP address, lets say it's Comcast, and they go to Comcast and say \"We have a warrant, who was using this IP address?\" and Comcast says John Smith was at 123 Mulberry Lane. Then the police politely knock on your door and ask you if you have a license for the dankness of your memes.\n\nNow there are ways around this such as connecting through different countries with different laws and using services which don't keep historical logs of IP addresses so you have to catch the person mid-connection to trace them. It's kind of like trying to mail a letter anonymously by dropping it without a return address in a mail box across town. You might get away with it once or twice but if what you're doing is of interest to the police they will have someone watch that mail box and all the ones in a mile radius to spot someone suspicious dropping something off then they'll pull you over for a chat. It's labour intensive and not perfect but they can find you.\n\nThe point to remember is that since machines require addresses to know where to send data too there is always a way to use that information to help track down a person or track down their approximate whereabouts.",
"happened to someone I know. Was uploading/downloading illegal shit and traded links. Got caught from ISP using their IP address. I saw the discovery... it had everything... usernames, log in windows, locations of log ins and how long they were active for. They used private mode and thought they were being slick.\n\nShort answer: Nothing on the internet is anonymous.",
"Because any time you, your dog, or your neighbors wifes boyfriend connects to the internet with any device for any reason with any amount of proxies [this](_URL_1_) [or maybe this if you are truly 1337](_URL_0_) is sent with every packet to every port on every server on the internet between your computer and the relevant data on a server rack or in the cloud and it is extremely easy for any sysadmin with any sort of basic understanding of real computer networking to pull up the handshake logs.",
"4chan is literally an FBI honeypot, and they use software to detect -- and deny posting permission to -- most users behind a proxy/VPN.",
"Unless they use Tor, or I2P or something similar it is extremely easy to track them, fbi hits up 4chan, asks for IP address logs from the user, finds out which ISP the IP address belongs to, contacts the ISP, asks for the address to that IP",
"Yes. Im a former analyst and can say its one of the easiest things to track via facebook, 4chan...any website. Just read up on meta data.",
"You know that mini computer in your pocket with the unremovable integrated battery? That's how",
"When you connect to a site, you give it your IP address (similar to a home address, but changes occasionally). That is because the internet functions a bit like mail: you send a message to to a website asking for its pages, the website replies to the address you gave it.\n\nWhen using 4chan, even though your identity is not displayed, you still leave your IP address there. There are some lows requiring site owners to store those IPs for some time, in case authorities need them.\n\nA proxy can hide your ip. Think of it like a shady friend. You ask your friend to post on 4chan for you and to send you back the replies. He does that, using his ip, and sends you back the page reply. The website knows what the proxy did, but hardly knows the true source of the requests. ",
"The scariest thing about 4chan is anyone could post CP, and if you were just browsing and accidentally came across a CP picture, the thumbnail would automatically be downloaded in your browser's cache or cookie folder. Possesion of CP is a crime similar to rape in the US.\n\nWhich makes me wonder, if someone's computer gets hacked and the hacker placed CP on their computer and then reported the victim for running a CP ring, wouldn't that person just instantly go to jail?\n",
"If you think that anything illegal that you do on the internet can be secret, you are fooling yourself. \n\nEverything is tracked, logged, and backed up from the moment you turn your computer on to the second your computer is unplugged from the wall. \n\nThere is no such thing as privacy or anonymous. \n\nJust because most public doesn't have access to this information does not mean that government agencies don't. \n\nThe problem is that a shit ton of marketing companies have access to a lot more of your personal information for their own personal gain than what the government has. \n\nGovernments do it to control you or to \"keep you safe\", Corporations do it to control your behavior and Farm your earnings. \n",
"Nothing on the web is truly \"anonymous\" due to the nature of the web. It's clusters talking to clusters whose jurisdictions change and laws change. There is no current \"uniform code\" for log retention. Back in the day we used IP Hopping and IP spoofing to hide what we were up to....these days the NSA has a backdoor into everything. PRISM is nothing compared to the real capabilities of the NSA. I remember eating Chinese food with Emmanuel Goldstein (and REBEL) in NY in ChinaTown one day and he basically prophesized everything we're dealing with today. ",
"The government has passed things called data retention laws which requires the host of a website to keep a list of all the IP addresses who visit the site, and which pages they have visited. \n\nIt can then either cross-reference this data with other websites where these users may have posted their personal details - such as Facebook or other social media which requires real information, or it can just contact your ISP which will have all your ID from your name and address to your banking details.\n\nIf you have posted online, you are not anonymous. ",
"Local and state police, the FBI, NSA and all those other agencies that combat terror can still get warrants for surveillance. I'm not trying to take that away, but the fact that they can get secret warrants pretty much at will is a fuckin problem. \n\nI'd rather take my chances w more terrorist attacks than give these agencies carte blanche w the info of 100s of millions of people. It's none of their fuckin business what kinda porn I like or what kinda shit I read. That nonchalant attitude towards your privacy is naive and concerning. \n\nThink of it this way. If you have a significant other and they've ever sent you nudes, personal information, SSNs, bank info or anything like that, the government has a record of that now and forever. Now think of all the government scandals you've heard about. Now imagine the less salacious scandals that probably just lead to a reprimand or firing. That's fuckin scary. You have no idea who has your information or what they'll do with it. \n\nLink to an article that talks about NSA employees trading nudes from illegal surveillance on American citizens: \n\n[Theyre really combatting terrorism ](_URL_0_) \n\nI don't know the answer, but I know unfettered government access isn't it. \n\nEdit : my grammar blows ",
"Wouldn't you like to know, you anonymous poster, you?",
"This is off topic....but is everything I've ever done on the internet going to be easy for everyone to find at some point? ",
"Does anyone have some literature suggestions concerning this stuff? Im pretty good with computers but this is quite on another level. ",
"Lots of programs gather anonymous data that anyone can buy. This is only anonymous to a certain extent because some data and web addresses are only accessible to certain people. For example I may be the only one able to access some address _URL_0_ so if that address shows up in the anonymous data FBI can be fairly certain this anonymous user is a the person behind this reddit account (me), further more they see that the same anonymous person has access to a similar 4chan account and a facebook account, and perhaps my ip address is even in there somewhere. Not so anonymous data any more.\n\nsource: heard the news about a paper about this being presented at a big hacker conference. They had managed to identify a judge in Germany and could see which porn he preferred. (bad link I know, but at least that should be enough info to google a good source)"
]
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"https://en.wikipedia.org/wiki/4chan#Arrests_for_child_pornography_and_cyberbullying"
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[],
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"https://www.dailydot.com/crime/tor-harvard-bomb-suspect/"
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[],
[],
[],
[],
[
"https://youtu.be/7G1LjQSYM5Q"
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"http://www.thesmokinggun.com/documents/internet/fbi-busts-4chan-man-extreme-couponing-098561"
],
[],
[
"https://krebsonsecurity.com/2017/09/who-is-marcus-hutchins/"
],
[
"https://m.youtube.com/watch?v=7G1LjQSYM5Q"
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[],
[],
[
"http://jimpix.co.uk/words/random-username-generator.asp"
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[],
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"https://www.youtube.com/watch?v=WzxEScuRu4A"
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[],
[],
[],
[],
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[],
[],
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[],
[],
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"https://www.youtube.com/watch?v=7G1LjQSYM5Q"
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"https://en.wikipedia.org/wiki/PRISM_(surveillance_program)"
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[],
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[],
[],
[],
[],
[],
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[
"https://ifconfig.dk/wp-content/uploads/2013/02/snort4_edited2.jpg",
"http://www.carbonwind.net/blog/image.axd?picture=2008%2f8%2fwireshark_ip_header_only.png"
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[],
[],
[],
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[],
[],
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"https://mobile.nytimes.com/2014/07/21/us/politics/edward-snowden-at-nsa-sexually-explicit-photos-often-shared.html"
],
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[],
[],
[
"www.reddit.com/u/TBNecksnapper/profile/settings/blablabla"
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|
3xfd3n | why uber costs the exact same as a taxi here in australia, what's the point? | I know it's like cheaper in America and stuff, but there's no difference here | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3xfd3n/eli5_why_uber_costs_the_exact_same_as_a_taxi_here/ | {
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"How easily can you get cabs in australia? I am from Singapore and theres almost no point to using uber because they cost almost the same as cabs, and cabs are really common. I went to las vegas a couple of weeks ago, there is an abundance of cabs along the strip, but anywhere outside of it, you can hardly find any. Without uber, i would have not been able to travel if I were not on the strip. The advantage uber gets you from my experience is availability rather than cost."
]
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[]
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|
7oxm37 | why does a baloon explode into many pieces when it is punctured with something sharp, but not do so when the bottom opening is opened? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7oxm37/eli5_why_does_a_baloon_explode_into_many_pieces/ | {
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"letting the air out of a balloon via the neck creates a rocket, popping a baloon creates a bomb. same amount of total energy, but one takes several seconds to happen, where the other takes several hundreds of a second. ",
"It's about the amount of strain that is on the point where you create the puncture. If you take a needle and poke a balloon right by the knot, where the pressure is lowest; it won't explode it will just leak. If you create a puncture in the side of the balloon where the stress is very high from all sides, the energy will be released more quickly and will shred some of the rubber under the most tension. "
]
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[],
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||
3gvwko | why does china seemingly want to cover up the number of deaths in the tianjin explosion? | Following the news, they originally estimated 14 deaths, since then that number seems to have crept up to arround 200 as families have posted reports (I assume through phone/internet)
They are also apparently censoring some Chinese websites.
What is their motive behind this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3gvwko/eli5_why_does_china_seemingly_want_to_cover_up/ | {
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"China has a long history of under-reporting the deaths of a man-made disaster. My girlfriend is from Qingdao, and her uncle was present when a major train accident happened. You saw cars twisted beyond recognition and the death count was easily over 500. But, nope, the official report was under 40. The government is really big about limited the exposure so people can't say they fucked up big time.\n\nThere are also cases of major mining accidents that killed hundreds. But the majority of the workers were undocumented migrants from poorer parts of the country. Nobody will come looking for them, so it's easy to write them off.\n"
]
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[]
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|
cy0ujv | how does information pass through the air? (ie, wifi, television, phone calls, etc.) how did someone learn to do that? what? science and technology literally blow my mind. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cy0ujv/eli5_how_does_information_pass_through_the_air_ie/ | {
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"Wireless communication usually uses radio waves, which are a form of electromagnetic radiation just like visible light is. While visible light is blocked by most solid materials, radio waves can pass through most substances to some extent, which is why you can use a cell phone from inside your house (but probably not in a tunnel underground).\n\nThe radio waves are created by passing an electric current through an antenna. When the radio waves hit another antenna, they then create another electric current. The electric current used to make the radio waves is varied to send specific signals, and the electric current on the other end is measured to decode those signals.",
"*(this is pretty high level basic - like even more basic than Karen at Starbucks in October)*\n\nImagine some kids holding a jump rope stretched out, and wiggling it so that it causes waves. \n\n[Like these kids I found on YouTube](_URL_0_)\n\nAt the very beginning of this video, the girl in the blue shirt is the \"transmitter\" and the black shirt is the \"receiver\". About two seconds in, they switch, and the blue shirt is now receiving. Let's look at the waves they're both generating. The blue shirt is generating a lot of short fast bursts, and the rope never really gets that high off the ground. The black shirt is sending slower larger waves. \n\nNow, if they both agree that \"a big wave == 0 and a small wave == 1\" we have a system for transmitting binary data. This works in theory, but we'd need a lot of rope! Here's where super awesome science comes in...\n\nIn the late 1800s, some German dude named Hertz set out to prove some ideas people had about electrical and magnetic fields; ultimately he was successful in proving the existence of invisible electromagnetic waves. \n\nNow, a \"eureka\" moment is actually pretty rare in science. More often, a discovery is not that \"big\" because they are usually building on previous work. Hertz was NOT looking for a way to transmit data with his research, however during the same time period, folks were thinking \"dang, this telegraph is awesome, but it'd be nice if we didn't have to stretch the wires all over the place. Can we do this another way?\" THOSE are the clever scientists who figured out how to ultimately harness these waves, and use them to \"pass information over the air\" that we all rely on so much these days.",
"something to think about is that radio waves have always been around but humans had no idea.....\n\nthere are almost certainly things going on right now that we have no knowledge or understanding of because they are beyond the perception of ourselves and our tools."
]
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boe7fy | do fish and insects feel pain differently? how do we know this scientifically? | People always say that those two groups experience pain differently than how humans do, usually defending the right to inflict pain. But how do we know this? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/boe7fy/eli5_do_fish_and_insects_feel_pain_differently/ | {
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"Feeling pain differently than humans is a tricky claim to make because pain is an element of your being. We can index it by the physical phenomena accompanying pain, but the phenomena isnt the complex emotional state itself. This leads to issues, because ultimately we don't know any way to scientifically measure the way that human A and human B experience pain differently. \n\nPain is a complex temperamental state with emotional properties that we have limited conscious access to. You could make the claim that fish or insects experience pain differently, but it's as shallow of a claim as is that those species experience every aspect of reality differently than humans"
]
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[]
] |
|
52l39c | how come there are nuclear powered ships,submarines and satellites, but not lorries or aircraft? | What are the pros and cons of nuclear powering an automotive? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/52l39c/eli5_how_come_there_are_nuclear_powered/ | {
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"pro - you won't have to fill up the tank for a long time, low pollution.\n\ncon - every wreck is a potential nuclear/radiological accident, fuel availability, disposal, easy availability of nuclear material to 'bad guys'",
"the USAF did experiment with nuclear powered planes a long time ago but it isn't economical.",
"Nuclear power plants have a couple of big limitations: They are large, heavy, and require specialized personnel to operate. They are also extremely dangerous to just crash into stuff as their internals being spread all over would be deadly.\n\nThis means that aircraft and automobiles are simply impractical; any automobile would be far too large and require a dedicated staff, while an aircraft would have a hard time getting off the ground considering the size and weight of the shielding. And for both of them you really don't have any answer for what happens if they crashed. Considering how often people wreck on the highways turning that into a nuclear disaster every time would be terrible, and nobody would allow a nuclear reactor to be flown over their country even if airliner crashes are very rare.\n\nA notable exception is [Project Pluto](_URL_0_). This was a project to create a nuclear ramjet unmanned missile which would be unshielded and supersonic, capable of cruising for months over the ocean before being directed toward targets in the USSR to drop nuclear bombs. It would then zoom low around the country at several times the speed of sound creating devastation with the shock of its passing, before running out of fuel and crashing somewhere in the country where it would spew deadly radioactive fuel all over the place and render the area inhospitable to life for thousands of years. The research was ended because it was deemed too horrifying to create, and the fear that doing so would force the USSR into developing something similar.",
"1 - If a ship has an accident at sea and sinks, it's a relatively-ok situation. I mean, it's not a good situation, but it isn't catastrophic to human life. Water is a good insulator for nuclear material, so it isn't a high-risk situation. Similarly, a satellite de-orbiting unexpectedly has a roughly 70% chance of hitting the ocean....and if we do it on purpose (such as to retire an old satellite), we can specifically time the de-orbit instructions to make sure it lands in a safe spot.\n\nCars and aircraft spend significant times over land. A disaster that might damage such a vehicle is more likely to pose a significant risk to human life. \n\n2 - Nuclear reactors are expensive to own and maintain, and require specialized knowledge to utilize and trouble-shoot. A naval ship not only can guarantee the personnel, but afford it. Indeed, it may be cheaper than having to repeatedly return to port to refuel. The cost savings for an aircraft or car--two devices that are frequently on land where fuel can be readily transported--are a different situation. Most people can't afford a nuclear reactor, let alone all the modifications required to make a car nuclear ready, let alone have the ability to safely re-fuel it.\n\n3 - The reactors are heavy. A car that wanted to carry a reactor would require a heavier frame and stronger wheels, most likely with a wide axle and multiple tires on each. Even if the car gets up to speed, it can't slow down quickly because the heavy reactor adds so much more momentum. \n\nPlanes are a little different, but the idea here is that, the heavier the plane, the more power it takes to maintain speed. Yes, we can get around that...but for most commercial aircraft, a reactor just may not make a lot of sense. \n\n4 - Any time you're using nuclear material, there's a security risk involved. Somebody might utilize the core of a reactor to make a dirty bomb or otherwise cause widespread sickness and injury. We generally keep that stuff out of the wrong hands. On a military vessel or an object in outer space, that's pretty easy. But if we made cars nuclear-powered, somebody somewhere is going to mis-use the product (even if we required security clearances to own the car, they can just kill the owner and take his keys). "
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[
"https://en.m.wikipedia.org/wiki/Project_Pluto"
],
[]
] |
|
23pvyg | why is it important to include race on college applications? | I completely understand the need to prevent prejudice but how does race as a determinant in college applications actually do that. If applications did not include race but merely merit, is that not more justice? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/23pvyg/eli5_why_is_it_important_to_include_race_on/ | {
"a_id": [
"cgzefwy"
],
"score": [
3
],
"text": [
"I think it's more for demographic purposes. So they can look at any time and say 50% of our student population is ______, 30% is _____, etc."
]
} | [] | [] | [
[]
] |
|
1ums5t | why is it so difficult to audit the military? | I understand somewhat if they can't account for EVERY dollar spent, but how exactly do they lose billions of dollars? Where does that money go? How did that happen?
If a private company lost billions, wouldn't they be up for criminal charges? Or is the military just so massive that it's impossible to account for this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ums5t/eli5_why_is_it_so_difficult_to_audit_the_military/ | {
"a_id": [
"cejmzno",
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],
"score": [
5,
3
],
"text": [
"Nobody with the authority to follow every dollar cares enough to actually trace it.",
"There are three main reasons:\n\n- Size\n- Secrecy\n- Political difficulty\n\n**Size:**\n\nAs you mentioned, the military is *huge* and incredibly complex. Billions of dollars easily represents just a few bucks per program, division, project, etc.\n\n**Secrecy:**\n\nA mass audit involves having a small group of individuals look at *every single expense*. In a business like the military, this can obviously have certain ramifications when you consider the risk posed by having all that information available in a condensed place reviewed by an external body. All the military's intelligence services, the advancement of new technology, etc... you don't want that falling in to the wrong hands.\n\n**Political difficulty:**\n\nIt's not popular to criticise the military, and to the common person, an \"audit\" has connotations of untrustworthiness and suspicion. A politician suggesting an audit of the military, therefore, is seen as being critical of the military, and in many places, that's political suicide."
]
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[],
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|
8od7j6 | how are some plastics immune to strong acids whereas significantly stronger materials will get melted through easily? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8od7j6/eli5_how_are_some_plastics_immune_to_strong_acids/ | {
"a_id": [
"e02isvr",
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"text": [
"It's to do with the chemistry of how acids work. Basically acids give up protons to other chemicals which changes the nature of whatever atom receives the proton. Materials that are resistant to acids are less prone to receiving those protons. ",
"Plastics are polymers, so they are made of carbon-carbon bonds. Carbon is extremely hard to dissolve using chemical methods, because it has no polar/reactive groups"
]
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[],
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|
7xc78p | the process of an hiv infection | Specifically, how the cell attaches/injects/replicates/infects other cells. What does it turn CD4+ cells into? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7xc78p/eli5_the_process_of_an_hiv_infection/ | {
"a_id": [
"du78val"
],
"score": [
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"text": [
"Based on the details given in the question, I'm assuming you have a working knowledge of general DNA processing, so I'm going to answer as such.\n\nHIV can attach specifically to CD4 receptors, which are commonly found on the surface of lymphocytes which help to stimulate a body's immune response\n\nOnce attached, HIV viruses inject RNA into the cell, along with a reverse transcriptase and integrase enzyme.\n\nThe first one converts RNA into DNA, the second integrates the newly formed DNA into the genome of the host lymphocyte\n\nThe HIV incorporated DNA can now be processed the same way that normal cell DNA is processed, and is read and transcribed into RNA, which is then translated into HIV proteins by the host cell. Eventually, once there is enough HIV, the lymphocytes are destroyed and the newly spawned virus spews out into the body\n\n"
]
} | [] | [] | [
[]
] |
|
47awq0 | what do those "make $4000/week working from home" scams actually tell you to do? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/47awq0/eli5_what_do_those_make_4000week_working_from/ | {
"a_id": [
"d0bmfra"
],
"score": [
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"text": [
"The NPR podcast [Planet Money](_URL_0_) did an excellent episode from 01/29/2016 on this called \"Anatomy of a Scam\". In case you're not into podcasts, I'll...\n\n**TL;DL(isten)**: It is a kind of MLM scheme. Those companies basically masquerade as online franchise opportunities. Franchises (KFC, McDonalds, Dunkin Donuts, etc) make their money by helping an independent owner up-front with the costs & branding of building a restaurant. The owner gets all the brand recognition that comes with the brand, as well as a structure for which to operate (trainings, decorations, national identity), as long as they follow the rules of the franchise agreement. \n\nThe online scammers sell you a template of how to set up an online store selling whatever--the products vary. The gigantic difference being that Dunkin Donuts is looking for owners who can actually run a store. They want their brand to be successful, and that success depends on each customer having a good experience at the store.\n\nThe Scammers are looking for someone who can quickly front money for a lot of licensing and training materials who they can then kick to the curb. Scammers won't be looking for someone's credentials and whether or not they can actually run an online storefront. They're looking to take money. The podcast actually profiles a call of a scammer talking to a 70 year old woman about how to set up a website. The scammer actually has the woman believing she can run a profitable store online & the woman can barely open an email.\n\nDoes that answer the question?"
]
} | [] | [] | [
[
"http://www.npr.org/podcasts/510289/planet-money/"
]
] |
||
3q1tlx | how does piratebay manage to stay online when megaupload couldn't? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3q1tlx/eli5_how_does_piratebay_manage_to_stay_online/ | {
"a_id": [
"cwbbel0",
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"score": [
8,
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"text": [
"Because piratebay has many serves in diffrent countries and they uses proxie sites _URL_0_, where megaupload only has one server and site which is very vunerable to law enforcments.",
"The PirateBay does not actually store files which could be subject to copyright laws, it provides an index of links to files stored in multiple locations to which they have no association. \n\nMegaupload actually stored content on its own physical servers."
]
} | [] | [] | [
[
"https://thepiratebay-proxylist.org/"
],
[]
] |
||
2f0wiv | seriously, why are toilet holes so small? | I feel they would clog a lot less if they would just increase the diameter by even 2-3 cm. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2f0wiv/eli5_seriously_why_are_toilet_holes_so_small/ | {
"a_id": [
"ck4tcnn"
],
"score": [
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"text": [
"Because it increases the pressure of the water that is pushing faeces down into the waste pipe."
]
} | [] | [] | [
[]
] |
|
5lxd2f | how did they know that is dinosaur skin ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5lxd2f/eli5_how_did_they_know_that_is_dinosaur_skin/ | {
"a_id": [
"dbz8ip5"
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"score": [
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"text": [
"If the DNA was preserved enough to amplify and sequence that's probably how they identified it. Maybe along with dating the sample to an era where dinosaurs walked the earth "
]
} | [] | [] | [
[]
] |
||
1xljpw | how do they make the automated machines that are seen on shows like "how it's made"? | How do they make the automated machines that we see on shows like "How it's Made" where they make various consumer goods or as we see in GIFs on /r/oddlysatisfying?. They seem so complex and some of them ingenious.. so how are they made, who comes up with them? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1xljpw/eli5_how_do_they_make_the_automated_machines_that/ | {
"a_id": [
"cfcfi2z",
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"score": [
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"text": [
"They are made by other automated machines. \n\nBut seriously, engineers. ",
"First design a machine that does just ONE job, but does it faster than humans can ever do (for example, putting labels on cans). Now design the next machine, same concept: one job, faster than humans until you have a different machine for every step of the manufacturing process. Then design a conveyor system to link it all up."
]
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[],
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] |
|
2ht5l4 | how did accounting start? | my question is at what point did we start having balance sheets, income statements and why? Especially in the early days where the cash was easily manipulable? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ht5l4/eli5_how_did_accounting_start/ | {
"a_id": [
"ckvre72"
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"score": [
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"text": [
"Accounting actually seems to have started before the writing of words. Counting flocks and crop yields and such appears to have led to the development of numbers and methods for keeping track of them securely so that transactions could be reviewed at a later time if there was a need.\n\n_URL_0_\n\n > The earliest known writing for record keeping evolved from a system of counting using small clay tokens. The earliest tokens now known are those from two sites in the Zagros region of Iran: Tepe Asiab and Ganj-i-Dareh Tepe.[6]\n\n > To create a record that represented \"two sheep\", they selected two round clay tokens each having a + sign baked into it. Each token represented one sheep. Representing a hundred sheep with a hundred tokens would be impractical, so they invented different clay tokens to represent different numbers of each specific commodity, and by 4000 BC strung the tokens like beads on a string.[7] There was a token for one sheep, a different token for ten sheep, a different token for ten goats, etc. Thirty-two sheep would be represented by three ten-sheep tokens followed on the string by two one-sheep tokens.\n\n > To ensure that nobody could alter the number and type of tokens, they invented a clay envelope shaped like a hollow ball into which the tokens on a string were placed, sealed, and baked. If anybody disputed the number, they could break open the clay envelope and do a recount."
]
} | [] | [] | [
[
"https://en.wikipedia.org/wiki/History_of_writing_ancient_numbers"
]
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|
52qevb | if earth had a longer day / night cycle would our body be able to adjust. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/52qevb/eli5if_earth_had_a_longer_day_night_cycle_would/ | {
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"If the day were 48 hours long the heat balance would be off. Imagine the hot part of the day, now cook the earth for an additional 12 hours, and simultaneously cool the other side with the heat sink of outer space. I have no idea what that would do to the oceans, but I would expect a significant change.\n\nHumans might be able to survive the swings in temp at the higher latitudes but the plants would not. ",
"Well this is already the case where I live. I live in the north, during summer time stands still and the sun is up 4 months straight. During midwinter we'll be lucky if we have an hour of daylight. To answer your question, yes we do indeed adapt to this. However even though we overcome it, it can be a daunting process. Finding sleep during summer is hard, warm temperatures (that don't change much at night because the sun is up) and light piercing any crack makes it really hard to sleep. It's not worse than stuffing ur window sides with sheets and putting a fan on though. During winter it's the opposite, we call it \"dark depression\" because people suffer from vitamine deficieny and the darkness combined with extreme cold turns people into zombies. The last few years those UV lamps have begun trending here, people put them next to their bed and run timers on them to create artificial morning light, it helps a lot. I gotta say though, during midwinter and summer if you don't have a watch you get time disoriented as hell. Especially during summer. "
]
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[],
[]
] |
||
f1bqmm | what is the reasoning behind voting in the presidential election if the candidate can win the popular vote but still lose the election? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/f1bqmm/eli5_what_is_the_reasoning_behind_voting_in_the/ | {
"a_id": [
"fh3hvkt",
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"score": [
5,
3
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"text": [
"To keep more populous states like New York and california from completely strong-arming the entire election process over more rural and sparsely populated states like the dakotas.",
"The vote still decides who wins so you still have to vote.\n\nThe president is a leader of all 50 states, so they are directly elected by the states. The people within each state vote to choose who their state will vote for.\n\nThis means if you win a lot of states by a small margin but lose a few states by a large margin you can will the election but lose the popular vote. You still had to win states, and to do that people in those states had to vote for you. If you don't vote you don't have a say in who your state votes for."
]
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[],
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] |
||
6pxjlo | why is cybercrime so hard to stop? | Recently my family has been a victim of cybercrime in the case of stolen identity. We have literally tried everything from contacting the server who claim not to host the website to shutting down each bank they use just for them to open another one. It seems like no one can do anything about it. Why is it so hard? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6pxjlo/eli5_why_is_cybercrime_so_hard_to_stop/ | {
"a_id": [
"dksxr8g",
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7
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"text": [
"The internet is a worldwide network. Cybercrimes can be committed from anywhere on Earth. Your local police or even the FBI do not have jurisdiction everywhere. ",
"Because nobody really cares about cybersecurity except for nerds like me who see the face of normal people glaze over whenever we start evangelizing.\n\nBecause we're all pretty much using a bunch of technology in ways nobody ever intended, for a bunch of *ridiculously* sensitive information.\n\nBecause banks and other financial institutions don't care about really verifying the identity of account holders, and so approve accounts so long as a name and SSN and a few other factors match, and don't bother with some more secure means of proving that you are who you say you are.\n\nBecause it's a global problem and we don't have a world-police.\n\nBecause people are the weak link in security now, and despite a ton of really good security options, they value the convenience of free wi-fi over making sure their bank account info is secure.\n\nSeriously, there are several conventions each year where infosec pros get together and bitch about how nobody else bothers to secure their shit, and talk about new ways people have found out how to exploit some bad piece of code\n\nBut really it doesn't matter because people are dumb trusting monkeys by nature and if I really want someone's identity, all I have to do is ask them the right questions the right way and they'll give it to me without a second thought until it's too late (important note: I don't *do* things like identity theft, but I work IT and I have had to stop people in the middle of giving me their social security number, credit card number, online banking password, and a bunch of other sensitive information, when all I'm trying to do is fix their youtubes.)"
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utfof | karma calculation | I just can't figure out how the system of karma works. Apparently an upvote doesn't directly give you 1 Karma Point, and you don't seem to get any, if it's a self post. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/utfof/eli5_karma_calculation/ | {
"a_id": [
"c4ydssg"
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"text": [
"Self-posts grant no karma. \n\nKarma numbers on comments and posts are fudged to prevent people who run vote-bots from knowing if the bot has been shadow-banned or not. Otherwise, karma and upvotes are a 1-to-1 relationship; 1 upvote is 1 karma. If you're upvoting yourself from a second account and it's not registering, congratulations, you have probably been shadow-banned.\n\nKarma means nothing."
]
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[]
] |
|
4dwlws | how come the /70's/80's/90's seem so distinctive yet the 2000's and 2010's don't seem to have distinct personalities? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4dwlws/eli5how_come_the_70s80s90s_seem_so_distinctive/ | {
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"The 70s/80s/90s had [many] defining dominate traits.\n\n > Technology: 8-track, tape cassettes, and CDs.\n\n > Musical genres: Disco, Heavy metal & punk, then grunge and rock.\n\n > Social movements: hippies, corporate culture, pop culture.\n\nOnce the internet hit in the mid-90s, technology and society has been ever-increasingly homogenized. Furthermore, the recent speed of technologic advancement means that you can't go more than a few years without something that would, in older decades, been decade-defining technologies: HD, bluray, 4K, 8K, VR.\n\nThere are now 1000s of musical genres for every intersection of taste. 1000s of TV channels for the couch. 10s of 1000s of books being published each year. Mobile internet and millions of podcasts and billions of videos across 100+ social networks.\n\nThe signal to noise ratio is [dropping] and will only get [lower]. We are no longer in a decade-definable society.",
"Because they're still too close to view with much objectivity, and are blending together in your perception. While decades in close proximity to each other will have a lot of common influences, they do have distinct characteristics--and you'll start to notice them more as more time passes. We're only halfway through the 2010s and the early part of one decade will tend to blend into the late part of the previous. ",
"Since we were adults in the 00s and 10s we saw that there was a lot more than just the stereotypes. People who were adults in the 70s saw the same thing. But we like to romanticize and stereotype our past.",
"You're getting a lot of bad answers. \n\nThe correct answer is what you think of as a distinct personality of those decades is really a heavily tailored image of those decades. It's not a real representation of those eras. \n\n",
"You can't see the microevolutions in the decade while you're living in them. The early 90's didn't feel so different from the end of the 80's. Sure the world wide web came in the 90's, but you see it as new technology at the time, not some radical cultural changing event. \n\nSame with cell phones, it was a new gadget, not a cultural game changer at the time.\n\nThe early 2000's we were stuck with texting on the numeric pad for cell phones, unless you had a blackberry. Laptops were big bricks. Late 2000's you have full on portable computers in your hand.\n\nI think having all that information at our fingertips almost anywhere in the world, and all that social connectivity dwarfs anything we had in the early 2000's. In a couple decades, you'll see what a game changer it is.",
"Short answer: it's too soon.\n\nImagine yourself in 2050 looking back at the TL:DR of these decades.\n\nSimple!\n\nThe 2000s were the War on Terror.\n\nThe 2010s were the decade of Facebook and iPhones.\n\nAnd now you see why older folks get annoyed when people think of the 1970s as the decade of bell bottoms.",
"Like another has said already, we're too close to the decades to really see it. Nostalgia for the 2000's hasn't had the chance to kick in yet. In some ways though, you're just not looking hard enough. \n\nIt's becoming easier to see, for example, a picture of someone may be from the 2000's. Baggier formal wear was a big deal, so were fohawks and a clean shaven look. And for women, shorter and straitened hairstyles were popular. People were really into wearing random brand names and old band logos on t-shirts. You had the emo kids, the grunge kids, stoner kids came back in a big way in the late 2000's also. People were still watching TV and shows like Family Guy and How I met Your Mother were huge. The 2000's saw a surge in comic book films as a serious medium, and the rise of digital production gave a lot of talented directors the tools needed to use CGI in more practical ways, this gave us a plethora of amazing movies that would have been impossible to budget before-hand. Documentaries became huge midway through the decade. Partially thanks to folks like Michael Moore and Morgan Spurlock. Also due to the increasing quality and variety of TV documentaries, and also of course due to the internet and viral mockumentaries. Hip-hop became the king of mainstream, while the world of rock and country sort of fused and southern-rock and pop-grunge became huge. (In the early 2010's we saw the peak of electronic music and dub-step which has already faded from the mainstream.) In the 2000's the video game industry became fully main-stream with the success of Halo and the X-Box, which paved the way for online competitive gaming and a booming popularity in MLG.\n\nRather than an over-all fashion adopted by the majority, fashion was more personalized than ever before. As far as literature goes, the 2000's saw some of the best works of literature in decades, with authors like Cormac McCarthy, David Foster Wallace, Michael Chabon, Zadie Smith, and the ever popular Stephen King, J.K. Rowling and Chuck Palahniuk. It's also hard to ignore the number of book-to-movie adaptations we saw in this decade. There were a lot of sports scandals in this time. This is also when UFC went mainstream, which also plays a part in the gym and supplement fad that took place. Overall health and well-being really became important to people and new markets for organic fruits and vegetables and farm raised animals spurred. The fact that everyone understood the deep irony of this at the time is also something to consider. It's only recently that the masses have been able to look on their own culture from an outsiders view.\n\nThe 2000's also saw the rise of the internet, as well as cell phones and text messaging. It really can't be stressed enough how much this changed the culture. People were making friends and lovers online. People could easily seek out others of similar interests for discussion on topics they care about. Whether or not people want to accept it, internet pornography also had a huge affect on people. Suddenly amateur porn was everyone's favorite. Young folks were learning the birds and the bees from their computers. Technological advances had put larger gaps between the generations and made for a more distant, less understood youth. Myspace reigned in the new world of social media, in which people have a personalized relationship with corporate advertising and police each other over habits, beliefs, relations, etc. People see protesting all over now, and it's become sort of trite. Back in the 2000's, before Facebook, Twitter and Youtube became huge, protesting meant so much more. It was near impossible to combat a media blackout and wearing a pot leaf on your shirt was akin to reposting a video of Bill Maher smoking a joint on tv...except then it meant something. The rise of the Global economy, or Global culture really took off in the late 2000's. Thanks largely to the internet. Basically what we have now is a culture of the [hyper-real.](_URL_0_)\n\nIn the first decade of the new millennium we saw Hurricane Katrina devastate a modern metropolis as well as the surrounding region along the lower Mississippi. America saw a mini migration of people from the area as those who lost everything went to find new beginnings. The impact isn't discussed enough but it was significant for our country. We learned to be ever more skeptic of the protection our governments offer us, and just how unprepared we are for earth's inevitable fury. The financial crisis of 2008 also had a significant impact. To employment, development, healthcare, education, really to everything. Situations like this have the power to tear countries apart, and it has. We are only now seeing the devastation caused, and we are going to feel the shockwaves for a long time still.\n\nBut possibly the most significant impact to the new millennium was of course 9/11. This event changed things in more ways than people even now realize. Pretty much every western citizen was suddenly a politically active one. What definitely started as intense patriotic loyalty and sense of duty quickly turned into activism and passionate skepticism. The lines that divide a society's culture from it's politics and corporate consumption became almost invisible. And that is something very important to understand about the times since then. Still today, the average person invests far more time and energy into politics than ever before. It is consumed in the same way that any product is. To the point where the very act of protest is now just another act of consumption of new media. Where as western culture was once defined quite clearly by pop-culture art, fashion and music. It is now defined more by digital activity and political activity. War has become normalized and the bar of ethics between a government and it's people has become increasingly lowered as the world approached and then hit the milestone of 7 Billion people. Also, it's important to note the continue fight for equality for minorities. The LGBT community has made HUGE strides in finding acceptance and a place of happiness in the culture. Consider that, just ten years before Brokeback Mountain (2005), people were still reeling in fear of HIV and AIDs. But still, we have yet to separate the politics from the people. It is interesting and intimidating to think of where this will take future generations. We have truly entered an unprecedented era.\n\nEdit: **TL;DR**: A lot has changed since the new millennium. More advanced tech has quickened the pace and number of cultural trends. These trends have to do with digital habits shared through cyberspace more so than in the past. Cultural identity is more personalized than ever.\n\nBy categorizing past decades by trends and intermixing in an ever-connected world, people are all too aware of their own identity. Things are more subjective now, and to be unique people actively pursue an identity to project. What we have now is a sort of meta-culture, a culture of the hyper-real. One which exists mostly in a digital world of consumption. Culture no longer separates itself from politics, science or industry. And all of it exists now in terms of new-media consumption.\n\nEDIT: Added examples\nEdit: added link",
"They are-\n\n90's: Tomagachi, Oregon Trail, music (Boyz2Men, N*Sync, New Kids on The Block, Blink182, Nirvana), giant puffy Starter coats, FUBU, getting your haircut like Jenifer Aniston or that lady from Ally McBeal, early memes, dial-up internet, physical book stores, mail order CD catalogs, Seinfeld, Simpsons, passport less travel between Mexico and Canada, virtual reality helmets, raves, AOL/Prodigy, myspace, napster, MTV, walkmen/portable cd players, cell phone that looks like a giant bag\n\n2000's: First black president, EDM, Hipsters (fashion and popular mentality), Leggings with Uggs and Northface jackets, Thick/large glasses, ugly as a fashion choice, Crocs, Wide leg jeans, gentrification of rap, AIM, deadjournal/livejournal, facebook, distressed clothing, emo, limewire/torrents, mp3 cds, early ipods, Harry Potter, monochromatic cell phones with text.\n\n",
"I think the people saying we're too close have a point. *But* I think there is something else at play.\n\nThe late 40s-early 60s had a very conformed vibe to them. We tend to think of around 64-68 as the \"the 60s\" because it was time of cultural upheaval and is inherently distinct for that reason. But the 60s as we *popularly* think of them didn't quite kick in for a bit. We were still on the whole \"dear god, whatever you do don't stand out for any reason\" kick that tends to come with a massive flood of nationalism like the one triggered by WWII. Something similar happened on 9/11 ending a decades long cultural freakout in one fell swoop of patriotic fever.\n\nThe 90s were a time of tremendous social and technological upheaval. For good and ill the government and other gatekeepers spent a great deal of the 90s playing catch up to the massive social innovations that came with the Internet and the sudden connectedness of global strangers. Then when 9/11 (and to a lesser extent Columbine) happened it became almost immediately unfashionable to be in any way counter to the bottom line: support our troops, never again flag waving nonsense. We went from an era where Marilyn Manson was allowed on broadcast television (and it made sense) to one in which The Dixie Chicks became pariahs for a throwaway comment about a guy we had all decided pre-9/11 might have been genuinely retarded. We went from goofy-ass raver fashion being almost mainstream to something which came to be known (and positively, mind you) as \"blandcore\". Technological innovation continued but *largely* back in the hands of the gatekeepers. And the tech wizards who had been the revolutionaries *became* the gate keepers. A lot of people forget also that a good deal of the progress we've seen on the LGBT front in recent years was actually closer to happening in 1998 than in 2005. The clock got reset on quite a bit in the Bush years.\n\nSo what we're seeing, I think, is a few decades bookmarked by conformist trends. Now, you can argue the 80s was the 50s V2.0 and there's a valid point to be made there, but I don't think it was anywhere near as confining as all that. Look at the popular media of the time and a surprising percentage of it is actually quite subversive.\n\nI also think Sanders and Trump, for better or worse, are proof that we're tired of that trend again. We're back in a place where the status quo seems to be back to chasing its tail. Even the upcoming Captain America movie (if it is at all comic faithful) is a massive allegory about the dangers of government overreach, a subject we could not have touched in a Disney movie any earlier. It was relegated to what was, at the time, a dying medium in its first telling. I predict the next decade will be a lot more interesting than the previous 15 years.",
"I felt the same way about the 90s until a few years ago when 90s nostalgia/parties seemed to become really popular. People in the 70s and 80s probably felt the same as well. It's just too soon.",
"People are saying it's too soon to tell, but think about the movie \"The Wedding Singer\". It was made in 1998 and set in 1985, and was funny because everything about it, particularly the clothing, was stereotypically 80s. \n\nI don't think we could remake \"The Wedding Singer\" now with the same time difference (13 years). Except for a few things like flip phones and CRT televisions, 2003 looked pretty much the same as today. \n\nPersonally I don't think even the 90s have a distinct personality compared to previous decades. If you drew a cartoon \"90s guy\", it would be much less recognizable than \"50s/60s/70s/80s guy\". ",
"When I was a kid in the 90's I thought it was strange that the 60's, 70's, and 80's all had their own little quirks, but the 90's were completely normal and couldn't believe it took people so long to figure out how to dress and act \"normally.\"",
"Fracturing of culture. If you're 30 and under you grew up in an interconnected era which encouraged you to do what you want. There is no normal anymore in culture in the US, you're almost expected to do your own thing, mix across traditional mores and cliques.",
"Senior year in high school (late 90s), we were put in groups and assigned a decade. We had to do a presentation on key historical events and fashion of that time. Apparently the teacher did this assignment every year, and I remember wondering how future kids would do the 90s, especially fashion, because it seemed not as distinct to me as the previous decades. Now if you were to ask me, portraying a 90s look would be very easy!",
"It's simple. We haven't had enough time to make a lasting caricature of the last two decades. Let's look at just one decade in your list of distinctive decades; the 70s. Some of the caricatures suggested in other comments are disco and hippies. \n\nWhile there were disco clubs in major urban areas, relatively few people went to them and few people of school age danced like that. Well, we danced like that to make fun of it. The first disco dancing many of us ever saw was in the movie, Saturday Night Fever (1977). We took the film as kind of a joke; no one in L.A. looked or acted like that. Yet this is one of the hallmark caricatures for a whole decade.\n\nAs for hippies, that movement was in the 60s. Boys growing their hair over their ears was the 60s. Braless girls was the 60s, or in very rural areas before that if you want to pick nits. But hippies is also used synonymously with the anti-war movement (it wasn't), civil rights (not really), the free speech movement (ever argued with a hippie; they were quite orthodox in their language). Hippies as a word has become a placeholder for a lot of different but concurrent things in the society of the 60s and 70s, but the hippie was already fading as the 70s began. The love ins, the communes, all of that was on the decline.\n\nSo the only reason past decades seem distinctive is because we've made them seem that way. \n\nAnd to those who say the Internet has changed things more than ever before, I say raspberries. Try walking in the shoes of a fifth grader, following the newly created space program like some rabid, hungry creature, watching the president of the United States be assassinated in black and white over and over again. What's next? Who did it? Should I duck and cover under my desk? Why did three astronauts have to die on the launch pad? Landing on the moon was a school holiday by the way. Are the Vietnamese going to kill us all? Why do the Russians hate us? \n\nChange is only meaningful in context. \"The age of...\" always diminishes the reality of a time.\n\nThat said; let me propose a few possible characteristics of the last 15 years that may end up as caricatures of this time. We're more distracted. We don't play as much or with as many things. We don't do as much. And we're much more sceptical. We don't trust governments or big business or Wall Street as much as we used to. And I think this is all for the betterment of our world. In one sense, today is the natural extension of the 60s, when we first questioned in a large manner the trustability of our institutions. So, you're welcome. ",
"What happened was the Internet.\n\nBefore the 2000's, the world was more disconnected. We didn't have instance communication. Lots of shit would happen in other places you didn't know about. Fashion changed a little more slowly. \n\nNow you have the internet, and a generation of kids who have grown up with this technology. You have people who are more informed as to what is going on in the world, as well as whom is wearing what, and access to all sorts of different music.\n\nPersonally I think things will get back to some distinctive decades, it's not like all of the 1900's had distinctive decades. In fact, in my memory, shit didn't start popping til the 1920's.",
"Dunno, SJW's were a thing in the 00's but a lot less pronounced. I don't remember hearing about \"safe spaces\" 6+ years ago.",
"Its all relative. I grew up in the 80's and 90's and felt the same about those decades until recently. It just takes time to see the differences.",
"I'd take issue with the premise, having been fully grown and aware throughout the 2000s and 2010s. There was a distinct character to the first decade of the new century; the difference with earlier decades is that we haven't had a lot of time to process and revisit it yet. 70s and 80s nostalgia is well-trod territory, and the emergence of nostalgia for 90s art, culture and fashion is in full bloom. It's difficult to distill the character of a decade (or any period) when it has only recently passed, and I'm 100% certain that in 20 years, kids will be ironically wearing Von Dutch trucker hats and \"awesome possum\" style thift store t-shirts and saying (without a whiff of irony or any sense of perspective) how great the post-9/11 era was. As an example, the new crop of internet sad girl, \"yung trash queen\" types fucking LOVE the strokes, almost without exception. Anybody who was actually alive when their first few albums came out basically doesn't give a shit about the strokes (the first album excepted)\n\nIt doesn't hurt the case for 70s/80s nostalgia in particular that the art and fashion of those decades was bright and colorful and vibrant, whereas that of later decades was more muted. 90s art tended to be drab and earth toned, the music was grungy, the movies were bleak and violent and our politics was a somnambulent neoliberal consensus that prioritized fitting in and staying quiet over making noise and fucking shit up. There were few riots, no real wars, everyone had money or access to credit and the most popular shows of the decade were about boring, rich white people with no capital-P problems to deal with. This trend eased up a little bit in the 2000s as our culture grew a little more restless and agitated, our politics were informed by violence and our art reflected dissatisfaction and unease with war, torture and the narrowing of our collective economic horizons due to the contraction of the job market. Our fashion was itself a throwback to earlier decades. It was a very dark decade and the culture reflects a lot of that darkness. It's hard to come up with a distinct character for those decades, at least one that's fun and sells well. And that decade only ended a few years ago. ",
"The do have differences. The 2000's had the \"era of the flip-phone!\" such as the Razor 2. WEP was all the rage, because for the first time, you could get INTERNET ON YOUR PHONE!!! The 2000's were started off in a recession with the dot com bomb in 2000, and then 9/11 happened. The country was on a war footing, and wanted to bomb everything middle eastern to get back at the Muslim world for taking down WTC and the pentagon. A 1Mbps connection at home in the mid-2000s was considered fast. People still wanted to have 200+ channels on TV, just for bragging rights, and \"I might miss something\"\n\nThe 2010's saw the decade start off with the collapse of the housing market, and the ever increasing technological boom in mobile phone technologies. Today, what used to cost $250 for a Motorola Razor 2, can be bought for $10 at Walmart. For the first time in history, people are ditching traditional payTV services, and either going to streaming media on demand, or returning to the old reliable TV antenna. Now, a 2Mbps connection at home is considered \"slow\", and it's not unheard of to have 50/5 Mbps service at home for under $100/mo. \n\nThis would have been unthinkable in the 2000's. An asynchronous T1 line would have cost several tens of thousands of dollars to run to a home and a monthly service charge of $1400/mo for a 1Mbps/1Mbps connection. For the same price today, you could get an OC3 line ran to your home.\n\nThere are significant differences between the 2000's and 2010's. Maybe not in the fashion world, but technologically? there is tremendous difference. Yes, you could take somebody out of 1998 and drop them into today, and as long as they're not wearing JNCO jeans, they'd be indistinguishable from anybody else on the street.\n",
"I'm old and have been in the 70s, 80s, and 90s, and my feel is that during the 90s there was already a sense of things being less distinct than the 50's, 60's, 70's, and 80's. Personally, I feel like a lot of attempts to be nostalgic about things from the 90s is more of an attempt to force it because people want to feel like different eras *should* have nostalgia. People reference things like grunge music and acid wash jeans and other things, but they just weren't anywhere as big a deal as, say, rock & roll in the 50s or bell bottom jeans in the 70s.\n\nThere is some truth that others have pointed out, that more recent years simply feel too close to \"now\" to have enough retrospect to see them as distinct. But, it looks to me that there is no particular objective reason why decades *should* have specific major trends to define them, it just happens to have been the case during a period of mass media consumption.\n\nI think one of the major reasons the time of major trends could be over is, of course, the internet. In the 80s and still into the 90s a bit, people were more sensitive to larger popular trends because of a lack of alternate options. Not zero alternate options, but as someone who never liked pop music and spent ages hunting for obscure and innovative music in import record shops, I can assure you it was way harder to stray from the paths everyone else was on. Now, though, via the internet, you can be into the most obscure thing and find a niche group out there that you can feel a part of. People are less likely to follow big trends and more likely to try and carve out individual preferences.\n\nWhich I think is a good thing. Massive trends are good for big corporations who like everyone to buy the same thing in huge numbers, but I'd much rather live in a world where everyone can find smaller communities with deeper connections.",
"Compared to previous decades we're practically living in an age of science fiction. Just in the last 15 years we've seen incredible technologies reshape our planet, and many are just in their infancy. \n\n Not only have we made a global transition to a digital format has also revolutionized every single aspect of our lives. \n\nWe trust our wealth to electronic banks, interact over social networks, and can earn online degrees without ever spending time in a classroom. Anyone can reach a global audience in seconds without ever leaving their home. \n\nWe have AI as virtual assistants and playmates. Particle accelerators are unlocking the very laws of reality. And many people walk around with a supercomputer in their pocket, capable of communicating with anyone at the speed of light and accessing all human knowledge. \n\nToday we have driverless cars, genetic modification, fully functional bionic limbs, weaponized lasers and railguns, military robots, drones, privatized space travel, video calling, stem cell treatments, 3d printing, virtual reality, cloud computing. We dont just take ideas like going to Mars or creating synthetic life seriously, we complain about not doing them sooner. \n\nWhether you realize it or not you are living in the future.\n\n",
"The ever-increasing rate of technology has sped up our culture. Video games, fashion, politics, news, language, social media, etc.",
"Info age. Trends and fads now travel so fast the world is becoming homogenized. Congratulations!",
"I dunno, I'm starting to recognize the early 2000s as being it's own thing now. Most of the original digimon adventure happened in early 2000 and the movie was 2001 I'm pretty sure (us for both). There was also iconic shows like Lost, prison break, 24, firefly, house, American Idol, futurama, spongebob, and the doctor who revival. And for movies there's shrek, LOTR, Harry potter, 300, x-men, and a shit ton more. And for music, this is where we got a lot of shitty punk type rock (God I love it though lol) such as sum 41, green day, and good charlotte. Also YouTube and reddit started within like 4 months of each other in 2005. And wifi became widely available.",
"Because nobody had smart phones so we had nothing to stare at all day. So- we actually had to go out and y'know...do stuff.\n"
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2jvy8n | why is soda + ice cream (aka a float) tasty but soda + milk gross? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jvy8n/eli5_why_is_soda_ice_cream_aka_a_float_tasty_but/ | {
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"Because ice cream is loaded w/ sugar, cream, and flavoring. Milk is not.",
"Soda and milk is delicious! We used to make it at my restaurant all the time. The key is to use coke or root beer, lots of ice, and pour the milk second. It's just like a paralyzer, but without the booze! Super delicious.",
"You just aren't used to the combination.\n\n_URL_0_"
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j88ro | how tax cuts reduce unemployment. | People say it all the time but I still don't understand how the two link up in any real way. Wouldn't the people just keep their money? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/j88ro/eli5_how_tax_cuts_reduce_unemployment/ | {
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"Some tax cuts do, others don't, but the basic idea is this:\n\nEconomists have demonstrated that government spending is in certain ways inherently inefficient; governments can't 'pick winners and losers' as effectively as investment in a free market. This is why command economies like the USSR can't compete in producing consumer goods. Money the government does not raise in taxes will instead be used by private individuals in one way or another. This might be consumer spending, but for the rich and for companies it means investment of one kind or another, whether investment in treasury bonds or new factories. The hope is that when you lower taxes and private investors have more money they will invest it in ways that create employment. In a purely economic sense this is true; the problem is that often that employment is being created in Shanghai rather than Michigan.",
"I have lots of money, but I'm lazy. I don't want to do any work. So I invest my money in this cool company that needs funding. The cool company hires a bunch of people with my invested money and they all get jobs. Once the company makes enough money to pay me back (with interest), they pay me back. The lower the taxes, the more money I have. The more money I have, the more I can invest.\n\nOn the other hand, I'm rich, and I pay taxes. Taxes go into the government budget, some of which is used to pay policemen and teachers and school bus drivers. So nobody is really sure if tax cuts really create more jobs.",
"Some tax cuts do, others don't, but the basic idea is this:\n\nEconomists have demonstrated that government spending is in certain ways inherently inefficient; governments can't 'pick winners and losers' as effectively as investment in a free market. This is why command economies like the USSR can't compete in producing consumer goods. Money the government does not raise in taxes will instead be used by private individuals in one way or another. This might be consumer spending, but for the rich and for companies it means investment of one kind or another, whether investment in treasury bonds or new factories. The hope is that when you lower taxes and private investors have more money they will invest it in ways that create employment. In a purely economic sense this is true; the problem is that often that employment is being created in Shanghai rather than Michigan.",
"I have lots of money, but I'm lazy. I don't want to do any work. So I invest my money in this cool company that needs funding. The cool company hires a bunch of people with my invested money and they all get jobs. Once the company makes enough money to pay me back (with interest), they pay me back. The lower the taxes, the more money I have. The more money I have, the more I can invest.\n\nOn the other hand, I'm rich, and I pay taxes. Taxes go into the government budget, some of which is used to pay policemen and teachers and school bus drivers. So nobody is really sure if tax cuts really create more jobs."
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14j1ao | how can my dog go from sitting by the fire to outside in the snow without apparently be bothered by the huge change in temperature? | To clarify, i take my dog out just before bed, where she goes from as close to the fire without burning to -5C (as it was the other day) and then precedes to sit in the snow whilst I have a cigarette shivering my arse off. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/14j1ao/eli5_how_can_my_dog_go_from_sitting_by_the_fire/ | {
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"They have fur which insulates them.\n\nEDIT: words."
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2s5mjj | does the immune system have a maximum learning capacity for vaccinations? | If vaccines "teach" the immune system to recognise and defeat viruses, is there a maximum number of viruses that the immune system can learn and remember to fight against before it doesn't have capacity to learn any more? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2s5mjj/eli5_does_the_immune_system_have_a_maximum/ | {
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"There can be a problem with your immune system being full of memory T cells for pointless things, but vaccines are not going to cause this.\n\n[CMV](_URL_0_) (Cytomegalo virus) is the biggest risk in this regard. It is endemic in the population, about 90% of people have it. It mutates very very rapidly, and is incredibly immunogenic, which means you will have [a huge number of memory T](_URL_1_) and B cells specific to old versions of CMV you no longer have in your body.\n\nWe are talking millions here, unless you are getting vaccinated 20 times a day, every day for your whole life, vaccines won't even come *close* to using up any meaningful capacity of your immune system.\n\nA vaccine is a specific strain of a specific virus, while a real infection with a real virus will result in a a huge swathe of different version of that virus as it mutates away from your immune response. This results in a huge amount of memory, as your immune system is always one step behind CMV. While a vaccine is only a snapshot, and the idea is you are then protected from getting infected in the first place!"
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4kvpao | is there a level of sugar in water at which if cotton candy was added, it wouldn't dissolve? | Seeing raccoons saddened by their cotton candy treats quickly dissolving in water, it made me wonder if there was a sugar saturation point at which you could dunk your candy in water without it immediately dissolving.
_URL_0_ | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4kvpao/eli5is_there_a_level_of_sugar_in_water_at_which/ | {
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"Yep. You can easily replicate this with a few sugar cubes in a small cup.\n\nBut you'd end up with a gloppy mess. The cotton candy would soak up the saturated water and its strands would weld together. It wouldn't be \"cotton candy\" any more, it'd be more like that glommy blob that happens when you leave cotton candy lying around open on a humid day.",
"Yes.\nThink about continuing to add sugar to the water until all the water has been absorbed by the sugar. At this point, there is no available water to cause the cotton candy to dissolve.\n\nOf course, at this point your sugar water solution is no longer a liquid."
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6qdp8v | why do we instinctively want to say things in certain orders. e.g "the big red hammer" sounds good but "the red big hammer" sounds unnatural when both are grammatically correct? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6qdp8v/eli5_why_do_we_instinctively_want_to_say_things/ | {
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"It's cultural, and it's also the way we convey significance. If there were 2 big hammers and you preferred the red one, you'd say red first because it clarifies what you mean. In French they say the noun first, adjective 2nd which would sound bizarre in English. "
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y83hz | how do i use a ssh tunnel to log onto websites? | I spend a good chunk of my day logged into Reddit while at the office. If the IT guy starts seeing _URL_0_ come up a lot, they might block the domain. My friend suggested I use a SSH tunnel to mask the activity. How do I do this? I do have a SSH client installed, but I never use it. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/y83hz/eli5_how_do_i_use_a_ssh_tunnel_to_log_onto/ | {
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"They are probably meaning that you should set up an ssh tunnel to an external computer (such as a rented server space, or in principle your home computer), and route all your traffic through it. I don't know how to do this offhand, and to be honest nobody is likely to walk you through the process on ELI5, it's a technical task that needs you to involve yourself and understand what's going on.\n\nAs a starting point, do you have two or more computers at home? Assuming so, a good way to begin would be to set up an ssh server on one of them then look up how to create a tunnel and use it for your web traffic. Neither task is difficult, they just need you to look up what to do and play with it. If you get that going, you can continue from there.\n\nAlso, don't surf reddit all day at the office.",
"You need a server to connect to as a proxy. If your home computer is accessible from the internet, run an SSH server on it. Then you create a local proxy with SSH on the client, and tell the browser to use that proxy.",
"The simplest way I can explain is like so, this is how your computer is connecting to the internet:\n\nYou --- > Your company's router --- > The internet\n\nWhen you request a page, say _URL_1_ from the internet, your company's router can see you've requested that, and what's came back to you - because it's the routers job to direct the right internet traffic to the right computer on the network. It will see \"Ol' Johnny boy's computer wants _URL_1_\" and pass that on to the DNS server to convert _URL_1_ to an IP address, that it can then use to retreive the page and say \"Oh where's Johnny, he wanted reddit?\". An SSH tunnel is just connecting to your SSH server first, and using it as a sort of middle man between you, and what you want from the internet. That way, your employers would only see you were asking for your SSH server, not reddit. It would look like this:\n\nYou --- > Your company's router --- > Internet - > Your SSH Server --- > The internet\n\nThis way you're still getting to the sites you want to, but your SSH server is getting them, and passing them to you (encrpyted) to your SSH client, so all your employer sees is that your connected to an SSH server.\n\nThe simplest solution is to set one up on your home computer, and leave it switched on when you leave home so you can connect to it. Often though people will just rent a server. Exactly how to set one up is a little tricky to explain like you're five. Instead of using an SSH tunnel you could use a Virtual Private Network to achieve the same goal because it encrypts your traffic. I don't actually know the difference between how a VPN works and how SSH works to be honest, but I wrote a PDF for a friend on how to set up a VPN relatively simply to bypass geolocation restrictions, you can read it here (caveat: it shows you how to set up a service that costs money): \n_URL_0_\n\nIf anyone stops any errors in that pdf if they end up reading it, or in this post could they let me know because I'm not a genius and I wrote this off the top of my head!"
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3cahc3 | why can't people withdraw their money from a bank that goes bankrupt? specifically those regular savings accounts? that supposedly have no such risk as it's a saving, not an investment. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3cahc3/eli5_why_cant_people_withdraw_their_money_from_a/ | {
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"Any money you put into a bank they use to lend to others. If they go bankrupt then they have absolutely nothing left and your money is gone",
"In America They're insured up to 100k - past that you're on your own - lots of people use multiple institutions as a way to protect their assets ",
"Banks use a fractional reserve system. For the sake of simplicity, let's say the bank has two customers, a saver and a borrower. The saver deposits $10,000. The bank can turn around and lend most of that money out. Let's say the borrower gets $9000 on a 10 year loan. The bank has $1000 left in the vault. If the saver want his $10,000 now, the bank has a problem and so does the saver. "
]
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[],
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||
26o02b | how glass gains its characteristics such as sound proof, bullet proof, tempered, flexable, etc. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/26o02b/eli5_how_glass_gains_its_characteristics_such_as/ | {
"a_id": [
"chsu77n"
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"text": [
"tempered glass in heat treated in such a way that it changes the glass molecularly. Bullet proof glass isnt bullet proof, its bullet resistant. The way that works is that it is really several pieces of glass laminated together. The lamination and the different pieces of glass work together to make it more bullet resistant. I have shot some with a pistol and a rifle. It stopped the pistol round but the rifle went right through."
]
} | [] | [] | [
[]
] |
||
3bk8yr | why do formula 1 cars require a certain amount of heat in the brakes and the tires to turn and stop quickly? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3bk8yr/eli5_why_do_formula_1_cars_require_a_certain/ | {
"a_id": [
"csmvzur"
],
"score": [
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"text": [
"Think about a piece of paper dragging across the table. \n\nIf the paper is dry it slides easily. It is hard and barely touches the table. There is very little friction.\n\nIf the paper is wet it won't slide at all. It is soft and sticks to the table. There is a lot of friction and the paper will stop quickly. \n\nHeating the brakes softens them. It doesn't quite make them wet but they less hard and have a lot more friction, sticking a lot better. It makes breaking and other things that need friction work a lot better. "
]
} | [] | [] | [
[]
] |
||
6a2wqa | without having a biased response, what exactly is sally yates role in the investigation with russia? | really don't know cause of the sites twisting words. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6a2wqa/eli5_without_having_a_biased_response_what/ | {
"a_id": [
"dhbbrtf",
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"score": [
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"text": [
"Sally Yates was acting attorney general. She has testified that in February of this year she informed the Trump administration that then National Security Advisor Flynn had lied to Vice President Pence about communicating with the Russian ambassador, compromising him to blackmail efforts. She was dismissed around the same time for refusing to enforce Trump's executive order banning immigration from certain majority Muslim countries. Flynn was later dismissed for his communications with the Russian ambassador, but only more than two weeks after Yates testified that she had informed the Trump administration and only after the story became public.",
"Sally Yates was the acting attorney general. (Meaning, she stayed on from the Obama administration while Trump waited for his new attorney general, Jeff Sessions, to be confirmed) \n\nIn December 2016, President Obama imposed sanctions on Russia.\n\nIn January 2017, it came out that General Flynn (who Trump had picked to be the National Security Advisor) made a phone call to the Russian ambassador the same day that Obama imposed sanctions. \n\nIt would be really problematic if members of the Trump team were undermining President Obama's foreign policy by telling the Russian government not to worry about the sanctions, that President-elect Trump wouldn't enforce them or would cancel them. In fact, that would be a violation of a little-known federal law. \n\nSo Vice President Pence went on a bunch of news shows and said that General Flynn definitely did not say anything about sanctions during these calls to the Russian ambassador. And Pence said he knew this because Flynn told him that he didn't discuss sanctions with the Russian ambassador. \n\nHowever, US intelligence agencies listen to the Russian ambassador's phone calls. So they knew that Flynn DID discuss sanctions with the ambassador. So they knew he was lying to the Vice President. \n\nThat's where Sally Yates comes in. She went to the White House counsel to tell them that General Flynn was lying to the Vice President. This was important, because the Russians *knew* Flynn was lying, so this was something the Russians could later use to blackmail Flynn. It would be a really bad situation if the Russians could successfully blackmail our national security advisor. \n\nShe provided more information to the White House the next day. However, General Flynn stayed on as national security advisor for almost three more weeks, until this information came out in the press. \n\n*Meanwhile* President Trump enacted the first travel ban. Acting Attorney General Sally Yates determined that the executive order, combined with Trump's past statements about banning Muslims from entering the country, was unconstitutional. So she said that the Department of Justice (which she was basically in charge of) would not defend the travel ban. She was fired later that day. "
]
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[],
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|
1lxdbv | if temperature is defined by the average kinetic energy of something, how does a fan blowing on me not feel warmer than room temperature? | Doesn't the fan increase the kinetic energy?
EDIT: I know how the fan takes away my heat thus making me cooler, but I guess I should have worded it, "why doesn't a thermometer read that the moving air is hotter than the room temperature stagnant air?" | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1lxdbv/eli5_if_temperature_is_defined_by_the_average/ | {
"a_id": [
"cc3of22"
],
"score": [
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"text": [
"Your body cools itself via evaporation: vapors and gasses can carry away a great deal of heat as they evaporate or transition from liquid to gas; it's the same principle that makes spray cans and refrigerators cold. That's why you perspire. Even if you're not perspiring heavily enough to produce drops running down your skin, you're still perspiring. A fan speeds up this cooling process because moving air carries your perspiration away faster than motionless air."
]
} | [] | [] | [
[]
] |
|
5cjglf | how do ants walk on walls? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5cjglf/eli5_how_do_ants_walk_on_walls/ | {
"a_id": [
"d9wyurt"
],
"score": [
5
],
"text": [
"Ants, like (probably?) every other insect, have little [pincers for feet](_URL_0_). This allows them to grab onto walls and ceilings. They hardly weigh anything, so they can easily hold their weight on the wall/ceiling."
]
} | [] | [] | [
[
"http://static.panoramio.com/photos/large/64049307.jpg"
]
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||
2aabof | will we ever run out of space for satellites to orbit the earth? | It seem like we have a bunch of satellites up there... Will we ever run out of room for them all? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2aabof/eli5_will_we_ever_run_out_of_space_for_satellites/ | {
"a_id": [
"cit2vjn"
],
"score": [
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"text": [
"We already allocate some orbits through international agreements. Putting a satellite in a geosynchronous orbit, an orbit that takes 24 hours to complete meaning the satellite appears to remain in the same place in the sky all the time, requires a lot of coordination between satellite operators. While the risk of a physical collision is small, these satellites are used for communications and they can interfere with each other if not managed correctly.\n\nThere is a lot of debris in earth orbit. There's enough risk of a collision between some debris or even between two satellites that NASA for example required additional \"hardening\" of the ISS after a review of the risks. There have been several examples of satellites being hit by debris and there are a number of known debris strikes on the ISS, but so far nothing has created a malfunction. The ISS regularly changes orbits to avoid debris, and a couple of times the astronauts have been ordered to enter their Soyuz capsules for an emergency escape due to the small but real potential that a larger piece of debris could hit the station.\n\nA couple of years ago a defunct Russian satellite collided with one of the Iridium satellites and created a large amount of low-orbit debris which remains a substantial hazard. It will eventually slow down through friction with the outer atmosphere and fall back to earth but that process will take decades.\n\nThere is a large European Space Agency satellite (\"Envisat\") that lost its ability to communicate with ground controllers, has no maneuverability as a result, and is stranded in a Low Earth Orbit that has a high number of large debris. It is estimated that a meaningfully large item of debris would pass within 200 meters every year. There is a risk that eventually it will be struck by something large enough to do serious damage because it can't be commanded to take evasive action.\n\nThese and similar sources of debris (like Chinese anti-satellite tests) could create a run-away sequence of cascading collisions like the one seen in the movie Gravity. This potential is known as the Kessler Syndrome.\n\n_URL_0_\n"
]
} | [] | [] | [
[
"https://en.wikipedia.org/wiki/Kessler_syndrome"
]
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|
1bjbgz | why colleges require that we take classes that aren't particularly related to our carrer interest/major? | Why do universities require us to take classes (that I have to pay for!) that have very little to do with our major? For example, If I'm currently majoring in Computer Science, how does a foreign language class benefit my major? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1bjbgz/eli5_why_colleges_require_that_we_take_classes/ | {
"a_id": [
"c975lsh",
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"text": [
"College isn't just about getting a degree, it's about building life skills and gaining experience that will benefit you in the \"real world\". \n\nPhilosophy helps you think \"outside the box\". Writing helps you express yourself eloquently. Literature helps you learn to imagine others complexly. \n\nSpecifically, foreign languages allow you to communicate with others you would otherwise never talk to and (for me at least) gives you a better understanding of your own language. ",
"Gen eds exist so that students can branch out and explore. You know all those people who change majors all the time? It's because gen eds let them see that maybe they'd prefer to do something other than their specified major. If they hadn't taken the gen ed, they wouldn't have known they had an interest in it.\n\nThat's the nice explanation anyway, and one that I happen to agree with. Taking gen eds opened me up to a whole new world of experience, and I was able to figure out my career path because of those classes.",
"If you wanted to just get trained for a career, go to a tech school. A bachelor's degree is supposed to make you a well rounded, educated person."
]
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[],
[],
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|
3ntanm | why are construction machines (backhoes, loaders, bulldozers) always yellow? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ntanm/eli5_why_are_construction_machines_backhoes/ | {
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"cvr24yf",
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"text": [
"Very simple answer for this. When you are shown a color circle, the one that stands out the most is almost always yellow. Yellow is the color that most easily gets your attention so it is important to help you imminently see the dangerous equipment.",
"It's for visibility. You're not going to miss a giant yellow bulldozer because it contrast almost everything else in an environment. The colour yellow can also been seen from a long distance.\n\nEdit: Subconsciously, the colour yellow says to us, \"pay attention, caution, look at this\" making it an even more appealing colour to use.",
"While most answers here are correct as they're all saying that yellow is great because you can see it easily even in the dark. One important thing is still missing: Yellow paint is much cheaper in production than most other colors"
]
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[],
[],
[]
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||
4krkfw | how do airports and airlines coordinate schedules across the globe? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4krkfw/eli5_how_do_airports_and_airlines_coordinate/ | {
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"text": [
"All aviation and nautical organisations use Zulu time. (Zulu as in the phonetic Z). Zulu time is the world standard time, if you like. It's the same at Greenwich Mean Time which is the same time as London's time zone. With this standard time organisations can coordinate things with counterparts in differing time zones. ",
"Busy airports assign a specific number of landing and takeoff slots to airlines. The airline negotiates the time of those slots and then uses those to determine what their flight schedule should be from city to city. They also take into account what flights their competitors are offering, and often adjust their schedule to match or compete between the same pair of cities.\n\nThe other issue is the use of gates at airports. Again, airlines get assigned a number of gate slots by the owner of the terminal (which can be an airline or an airport authority). Gate planners work at the airport to update the gate assignments based on changes during the day to maximize the usage of the gates. Each type of aircraft and airline takes a known amount of time for the turnaround (deplaning, cleaning, galley service, aircraft service, boarding), and the equipment needed is also planned for and arranged.\n\nAir traffic control has congestion measures in place at extremely busy airports and assigns specific arrival slots for each airline and flight. They will hold flights at their departure airport if things get backed up at the destination, ask flights to adjust their speeds during flight and then have aircraft hold at specific points near the destination to smooth out the traffic flow.\n\nCustoms and immigration also play a factor, arranging for only so many international arrivals per hour.\n\nThe entire system essentially self regulates. No airline wants a valuable aircraft and crew sitting idle at an airport or waiting in hold patterns burning fuel, so they have flight planners and schedulers working hard to sort the whole mess out."
]
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[],
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||
8vl0os | why does fox keep cancelling popular shows such as b99 and lucifer? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8vl0os/eli5_why_does_fox_keep_cancelling_popular_shows/ | {
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"text": [
"People don’t think the shows are as great as you do so they don’t tune in and the fuck it doesn’t make enough money so they canceled it",
"It's important to remember that it's not about enough people watching or the show making money or not. It's all about the canceled show vs what could potentially replace it. \n\nSo for B99, the show does OK. But it's an ensemble cast and that's expensive (lots of actors to pay). \n\nBut there's more to ratings than just ratings. There' also ratings retention. So on Sunday Nights Fox airs some 30 minute comedies. There's the Simpsons, B99, Family Guy and Bobs Burgers. The idea being that a popular show, the Simpsons, attracts the viewers and they stay tuned in to watch the next show, then the next then the next and so on. \n\nIf you look at actual ratings, B99 loses a bunch of the Simpsons viewers, and they come back for Family guy then most stick around to watch Bobs Burgers. But the big dip of the evenings is B99. The general thinking is that another show in that slot might retain many of the lost Simpsons viewers and then lead to even larger Family Guy numbers. \n\nDuring this Sunday night most of these Fox shows sit around a 2.0 for ratings. B99 generally gets a 1.75 or there about, Simpsons and Family guy are a 2 or 2.25 and Bobs burgers sits at a 1.8 or 1.9.\n\nCompare this to the other networks on that same night. For example on Sunday May 13th Brooklyn 99 pulled a 1.76. It went head to head with American Idol, 60 Minutes and something called Genius Junior. All 3 of those shows had better ratings (7.84, 7.45 and 2.81 respectively). I've literally never heard of Genius Junior, it still beat Brooklyn 99 by almost double.\n\nAs a network, Foxes lineup places in last place every Sunday. Every single Sunday night, more viewers tune into 60 minutes than tune into Fox and NBC combined, and 60 minutes is only 2nd place in that time slot! Fox is not going to beat American Idol or 60 minutes but if they could retain the Simpsons viewers they might push family guy up by a few points and be able to claim third place rather than settling for 4th for the night. \n\nYou see these shows that have large online followings and fandom but that often does not translate into large numbers of actual viewers. The shows often appeal to a very specific demographic and while those people REALLY love the show thre's not actually that many of them."
]
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[],
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||
x7qns | how can _url_0_ keep all those photos stored on their servers? | If I'm a complete idiot, feel free to call me out on it. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/x7qns/eli5_how_can_imgurcom_keep_all_those_photos/ | {
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"text": [
"Hard drive space is pretty cheap these days. The last time I bought a hard drive you could get 1.5TB for $100, and that was like three years ago.",
"Why don't you ask MrGrim himself. He is a regular at _URL_0_",
"Of course the actual answer is a lot more complicated than \"on big hard drives\" - as there's probably many layers of complexity between \"user uploads photo\" and \"photo ends up on a hard disk\".\n\nSo what's likely happening is:\n\n* Photo is uploaded\n* A service at imgur resizes the photo, assigns it a unique name, and collects information related to the photo (like the user that uploaded it, whether it's a part of an album, etc)\n* The information collected by that service is then stored in a database (basically, just imagine a really big Excel table)\n* The image is saved to a storage device - this can be the really complicated part, and I imagine it's what you're trying to figure out so I'll go deeper..\n * Imgur either hosts their own storage, or rents it from what's now commonly refered to as a 'cloud storage provider' (example, [Amazon S3](_URL_1_))\n * Regardless of the above, the image you upload ends up on some sort of SAN - a SAN (Storage Area Network) is basically a giant cluster of hard drives which can be carved up into chunks of storage and assigned to specific servers. A SAN (at least, a good one) is built in such a way that every bit of it has another bit that can take over if the first fails - it stays up if disks die, if hardware dies, if cables are unplugged - it's built to survive almost any imaginable single failure.\n\nAnd that's it, your image is uploaded, its information is living in a database, and the file itself is spread across a number of hard disks in a SAN.\n\nNow when people go to view that image, another thing happens entirely:\n\n* A webserver gets a request for \"xI8u6v.jpg\" and asks a service \"Hey, I need to know about xI8u6v.jpg\"\n* The service queries the database (remember, like giant excel table) that has all the information about \"xI8u6v.jpg\" and tells the webserver \"xI8u6v.jpg is located on this device, and it's part of the \"Cute kittens LOL\" album created on this date and has this many views.....etc\"\n* The webserver puts together a HTML page with the data the service box returned and sends it out to your web browser.\n\nAnd just to add one more bit to this whole shockingly complicated process - imgur likely utilizes a CDN (Content Delivery Network) to get all those cute pictures of cats to you even faster - a CDN (like [Limelight](_URL_0_), or [Akamai](_URL_2_)) basically maintains mind-bogglingly huge and fast networks of servers and storage at thousands of places all over the globe. Why?\n\n* Because it takes longer to transfer a picture of cats from Seattle to New York than it does from New Jersey to New York.\n* Because Imgur's webserver (and hard drives/SAN) probably can't handle all the requests for cat pictures on its own - and it's too expensive to build it at such a scale that it could handle the traffic from a bunch of front-page images and redditors on their lunch hour. I mean, open your biggest \"pictures\" folder on your computer, and watch how long it takes to build previews of each photo - now imagine hundreds of thousands, if not MILLIONS of people doing that at the same time and you can imagine how things start getting real slow, real fast.\n * Not to mention, it'd be a pain to build a server to handle all the traffic from a hugely popular post when you don't need to handle all that traffic all the time - most of the time your investment in big hardware would wasted\n\nSo, the CDN sits between you and Imgur - and when it sees your request for \"xI8u6v.jpg\" says one of two things:\n\n* \"Oh shit, I don't know what that picture is\" - and goes to imgur, downloads the image and remembers it in case someone else nearby wants it\n* \"Oh some guy near you just asked for that picture, I remember it! Here you go...\" and sends you its copy.\n\nFin.\n\nI hope that was pretty basic. It's kinda hard to simplify some of these things. :)"
]
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"Imgur.com"
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"http://www.limelight.com",
"http://aws.amazon.com/s3/",
"http://www.akamai.com/html/technology/dataviz3.html"
]
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|
1zg58i | why is samsung able to release new technology/products at such as fast rate and apple waits so long to release new tech/products? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1zg58i/eli5_why_is_samsung_able_to_release_new/ | {
"a_id": [
"cftclal"
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"text": [
"Different marketing schemes. Samsung's plan is to offer a variety of products that fit whatever needs you have. Apple's plan is to offer one product that can do \"most\" of what \"most\" people want. Each has its pros and cons, but it's not a question fo one being \"able\" to release new products while the other is not."
]
} | [] | [] | [
[]
] |
||
40dkur | how do crows and other birds with one "call" communicate? | How can these birds differentiate between what seems to be the same sound? Is it the amount of calls in a sequence? The length? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/40dkur/eli5how_do_crows_and_other_birds_with_one_call/ | {
"a_id": [
"cyte5eu"
],
"score": [
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"text": [
"The simple answer is they don't have a single call...birds, including crows have dozens of known calls which vary in length, pitch, tone, and sequence. The context in which the call is given can also give the receiver clues about its meaning and intent. Its difficult for an ordinary person to distinguish these calls but an avid birder and ornithologist can. Moreover, with the advent of better audio recording equipment ornithologists have revealed that many calls that we thought we simple to the ear are quite complex on tape. This means that some calls which birders might have labelled as a single call can be now split up into many more calls based on audio recordings...this obviously adds greater complexity to each species call repertoire. Audio recordings have also revealed that bird calls can even range into frequencies that humans cannot hear. That means that birds can be communicating right in front of you and you would never hear it with your own ears, its either too high or too low a pitch."
]
} | [] | [] | [
[]
] |
|
1x29de | why haven't we found a way to permenantly remove hair for good? is it even possible? | Edit: Laser Hair Removal actually does not permanently remove all hair, it thins the hair deeply.
I am talking about removing the hair follicles completely so that no hair can grow again. Maybe some sort of chemicals that they can do extensive reseach on. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1x29de/why_havent_we_found_a_way_to_permenantly_remove/ | {
"a_id": [
"cf7ict7",
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"score": [
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2
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"text": [
"Electrolysis is permanent and has been around for a while. However it is time consuming, can be very painful, and is prohibitively expensive for large areas",
"You are seriously gonna piss off a lot of bald people with this question"
]
} | [] | [] | [
[],
[]
] |
|
azqtui | what is the difference between slander, libel and defamation? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/azqtui/eli5_what_is_the_difference_between_slander_libel/ | {
"a_id": [
"ei9j6qc",
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5
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"text": [
"Defamation is when you make a false statement to a third party that damages the reputation of the targeted party. \n I stress the third party because it is not defamation if you make a false claim to the person directly; it has to be directed to somebody else. Slander and libel are both forms of defamation. Slander is when you say something incorrect and damaging. Libel is when your write/print/draw something incorrect and damaging.",
"Defamation is when you damage someone's reputation with something you say that isn't true.\nYou have to address it to a third party and they have to think less of the person.\n\nSlander is spoken about. You gossip about someone or otherwise speak in public about it on your soapbox.\n\nLibel is written, so you wrote an article in a newspaper or published a book about the topic. It also covers websites and social media.\nConfusingly, libel also applies to TV and Radio, so if you were on TV and said something there then you would actually commit libel not slander.\n\nYou can't libel someone unless the material is seen by a third party. So writing in your diary doesn't count. It also has to cause them some kind of damage. i.e you stopped someone getting a job or promotion because of your gossip.\n\nThe main defence to libel or slander in court is that what you said is true. Depending on the jurisdiction you often have to prove whatever it was that you said was true on the balance of probability.\n\nThe above only applies to living people, if they are dead you can say whatever you want."
]
} | [] | [] | [
[],
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||
2n8zt8 | how do bills and fines work for foreigners? | How does a traffic fine or a bill for medical expenses or similar work for foreigners? I.e. you go on a vacation and get sick and have to be treated in hospital without insurance. And you go back to your country and then what? Can you default on your payment and what would the consequences be? Same way for traffic violations, etc. (I'm talking general here and not only USA) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2n8zt8/eli5how_do_bills_and_fines_work_for_foreigners/ | {
"a_id": [
"cmbgzvz",
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"score": [
5,
2
],
"text": [
"1. medical expenses, hospitals would most likely use debt collection agencies, these agencies would have contacts in other countries. The foreign agencies may be able to turn the case to local authorities, or settle it in court. \n 2. Traffic fines. Traffic fines obviously are handled by the authorities, they would be able to contact the local authorities in the residents country. \nSide note: failure to pay fines In your home country can result in your license being revoked, failure to pay fines in a foreign country (who don't have the authority to revoke your license) can revoke your license to drive this means that while you may have a valid license you are not allowed to drive in that Country (or state)\n*edit:spelling*",
"In the UK fines are normally paid on the spot at the roadside. At court if a person is unable to pay a fine they imprisoned for a period of time."
]
} | [] | [] | [
[],
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|
1z2k85 | i'm not allowed to donate blood because i'm on multiple mood altering meds. why am i allowed to be an organ donor? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1z2k85/eli5_im_not_allowed_to_donate_blood_because_im_on/ | {
"a_id": [
"cfpxqtn",
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"text": [
"There are techniques that can filter literally anything out of blood/tissues. But they are expensive both in time and money, or at least expensive enough to make it inefficient to take your blood (because they can take it from somebody else that doesn't require filtering).\n\nOrgans are WAY more rare, so if you can get a compatible one it is worth it",
"Setting aside stuff like chemo...\n\nYou take meds when you are alive. They're in your bloodstream, altering moods and influencing cholesterol. You die. Sure, your organs are going to have these drugs in them to varying degrees depending on form and function... liver over heart, kidneys over eyeballs.\n\nWhatever's in there that doesn't get filtrated out before implantation, \"should\" get addressed by the receiving host.\n\nKeep in mind... if a \"bacon only\" dude dies and is also an organ donor, they might pass on the heart. Copy/paste along for alcoholics/livers and so forth."
]
} | [] | [] | [
[],
[]
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1cmlrg | why do banks charge a "service fee"? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1cmlrg/eli5_why_do_banks_charge_a_service_fee/ | {
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"Because it costs them some amount of money to do a particular act, either a computer or a person has to handle it. Since that costs money, and you will willingly pay that money, they charge you for it.",
"If you keep a good bit of money (say 5,000) in your account at all times, they won't charge any fees at all because they can use your money to earn extra to run the bank. If you have a low balance and spend everything as soon as it hits your account, then they can't earn anything from your money, and have to charge a fee instead. \n\n",
"Because of money and because they can."
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4se2gp | why didn't either of the wtc towers collapse sideways? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4se2gp/eli5why_didnt_either_of_the_wtc_towers_collapse/ | {
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"Because the planes don't have enough energy to push the towers sideways, as a matter of fact skyscrapers are designed to deal with high wind/earthquakes etc but when the planes crashed it destroyed the support causing it to essentially collapse on itself.\n\n\nJet fuel can't melt steel memes.",
"Most buildings in populated cities are engineered to collapse in on themselves to minimize damage. Imagine how much worse it could have been if it would have fallen sideways.",
"Gravity pulls downwards. The building had a massive amount of weight, a lot of empty space, and didn't fall from being nudged over it took time to fall after the impact due to the fires decreasing the yield strength of the building supports. The building reached a point where it couldn't support its own weight, so gravity pulled it down. It was not knocked over by an impact like a domino. ",
"Skyscrapers are designed to fail safe - in the ~~effect~~ event (words are hard) that the support structure is compromised, they fall into their own footprint.",
" > So, I was thinking, that hitting a tower side on like that usually causes it to topple sideways\n\nNot to come across as all skeptical and what not, but have you seen many towers collapse by being hit on the side and falling over sideways? \n\nAdditinally, given that the planes didn't introduce any noticeable lean, and the towers fell *significantly* later, would you really expect the collisions to have imparted a lot of momentum to the tons and tons and tons of material?",
" > that hitting a tower side on like that usually causes it to topple sideways\n\nWhat do you base this on? Where have you ever seen a skyscraper fall sideways, other than in a big Hollywood movie?\n\nI think that's the problem here -- you're confusing theatrical special effects for actual physics. In this case, the structure was strong enough to withstand the initial impact, but the burning jet fuel eventually weakened the structure so it fell. And when something falls, it will fall down unless there's some significant force causing it to fall in some other direction.",
"The momentum of the planes hitting the towers didn't knock them over. It didn't damage the structural members significantly. All the momentum from the crashes was dissipated into the building.\n\nWhat caused the failure is that the structural members on one side of the tower(s) were heated asymmetrically — which caused them to expand much more than the members on the opposite side.\n\nIf you've ever tried to carry a couch up or down stairs, you'll know that the person on the lower side is carrying a disproportionate amount of the weight of the couch. \n\nIf both people are level, then each is carrying fifty percent of the weight.\n\nIf one person is a few degrees lower than the other, they carry a much higher percentage of the weight.\n\nSomething similar happened. The structural members on the side away from the fire ended up carrying not just the weight they were designed to carry, twentyfive percent of the upper stories, but the weight of over forty percent of the upper stories, because of the tilt.\n\nThey gave out. Then, like dominos, the weight fell on the remaining members. They too gave out. That happened very quickly, not giving time for the floors to slip sideways.\n\nThe momentum at that point was entirely downward. As the top several floors came down, they snapped each floor's structural members or tore them off. Pop pop pop pop pop pop … \n\nIf you want something that models it, build a model of it with toothpicks. Load the upper part with weight. Then dab water on the toothpicks on one side.",
"Mainly because of the way they were built. Normal skyscrapers have an \"exoskeleton,\" they [look like this during construction.](_URL_1_) The beams and girders on the outside are the main load-bearing structures, and all the walls, floors, etc are hung on that skeleton. If you did serious damage to a building of this type, part of it might very well topple over sideways.\n\nThe WTC was fundamentally different. Because the buildings were so tall, you couldn't build them with the traditional steel beam technique, that wouldn't hold the weight or the wind shear forces. So instead, [the WTC buildings had an \"endoskeleton,\"](_URL_0_) a big-ass central steel core that was the primary load-bearing structure. Each floor was hung on that central support.\n\nSo when the planes hit the outside of the buildings, they weren't running into much of any load-bearing stuff, they just plowed through glass and light material until they impacted the central core. The core undoubtedly sustained some damage from that, but held initially. But as the fire continued to burn out of control, it weakened--NOT *melted*--the steel supports holding the floor to the central column. And when that steel had weakened sufficiently to let the floors above that point drop down a level, floors started collapsing straight down, and the inertia of that mass became an unstoppable force.\n\n"
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4ydf19 | h+ and oh- ions role in electroplating. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ydf19/eli5_h_and_oh_ions_role_in_electroplating/ | {
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"Not going into deep chemistry, these ions doesn't do much in electroplating.\n\nElectroplating is when you attract ions of a metal with electric current onto another metal. You don't bother with other ions during that process. Every mole of coated metal equals to one mole of dissolved metal on the other electrode, so H3O(+) and OH(-) ions wont get in your way. Since the metal you want to plate will have negative charge there will be some reactions producing hydrogen that may lead to hydrogen embrittlement, which is when atomic hydrogen dissolves in steel and make it more fragile, but its not that bad in electroplating temperatures. "
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4flhv9 | why do cats get "the zoomies"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4flhv9/eli5_why_do_cats_get_the_zoomies/ | {
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"We call it \"the poop run.\" Right after she goes to the bathroom she tears around the house like she's on fire. \n\nDoes anyone else have a cat that does this?",
"Cats spend the majority of their time grooming, eating, and sleeping (mostly sleeping). They need some way to burn off their energy, so they run around like crazy. It even has a fancy name- \"frenetic random activity period.\"",
"Oh I thought they ran after popping because they're trying to rid their butts of any poopsy berries ",
"Mine does this all night, while screaming as loud as she can, and napping every hour or so. ",
"Mine does this 10 minutes after I get home on a daily basis. \n\nAlso, when I am on the phone, or just whenever she wants.",
"Mine do this, but not just in conjunction with pooping. They just seem to get a wild hair and race around the room making this very distinctive sound that only occurs during a \"wild kitty episode.\" Whatever the cause I'm glad because it's super entertaining. "
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1ycc44 | why do americans love pickup trucks so much ? | I have been to american two times and I have seen more pickups in the time I have been on vacation in america than I have seen my entire life here in Norway. Over here the pickup truck is used like an utility vehicle and not as a family car. What use of the pickup truck has the american family that the european family doesn't have. I do not have anything against pickup trucks, I'm just wondering.
Sorry for any bad cases of english :) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ycc44/eli5_why_do_americans_love_pickup_trucks_so_much/ | {
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"A lot of it is marketing. We're supposed to be hardworking cowboys, men who get up early and drink thick coffee before a day on the range. Big skies, cigarettes, and the companionship of a fine dog. All that sort of thing.\n\nThat aside, though, many of us do actually use them a lot. I recently buckled after eight years and bought one, and it's done four jobs in a week that I previously would have had to rent a truck or borrow a friend for. Is it possible that you live in a heavily populated area in Norway, and have visited a lot of rural areas here?",
"There were a series of emissions and fuel economy regulations that were brought in in response to the 1970's oil crisis called CAFE. CAFE set different limits between cars and trucks so to avoid hurting commercial vehicles, but manufacturers started to exploit the regulations by building new car models which fit into the truck category - such as SUV's and minivans\n\n_URL_0_",
"Part of it, is that the US doesn't pay as much for fuel as many European/Scandinavian countries. On average, we pay about half of what you do for fuel. Therefore, having a utility vehicle that gets poor gas mileage is not as big of a luxury as you might think. \n\nTrucks are useful. Many of my relatives are tradesmen and use their vehicles to haul buidling materials and tools. Many people are avid hunters too. A large truck bed is ideal for putting a deer in. \n\nAlso our public transit is dismal in many parts of our country. We heavily rely on our vehicles for basic tasks and transport. \n\n\n\n_URL_0_\n\n\n",
"Beyond the marketing the pickup was a work vehicle that has been around as long as there has been automobiles. When the majority of American's lived and or worked on farms the pickup was very important to easily haul things around. As time has gone by and generations have passed people use pickups less for work/income generation and more for the convenience of being able to move things. Adapting to this shift the auto manufacturers have built more luxury style pickups (large cabs for hauling more people, DVD players, heck even built in wi-fi in some). The idea of course is that the more luxury pickup will provide the dual purpose of being a family vehicle while providing the utility of having a pickup bed for hauling stuff. (Why have a van and a truck when you could just have a nicer truck?)\n\nAmerican families tend to have a lot of stuff, as evidenced by the ever growing number of storage facilities. People have so much stuff, and don't get rid of it, to the point they don't have space for it in their house/condo/apartment, thus they rent storage space. Having a pickup means you don't have to rent on or borrow one any time you want to move things from your storage unit. \n\nOn top of our mass accumulation of stuff we like our boats and fifth wheel trailers. Having a pickup is almost a requirement of having a boat or a fifth wheel (an SUV could work as well) because you need a means of moving the boat / fifth wheel in order to use them. \n\nTL;DR: Modern pickups have the same amenities as any other passenger vehicle, and in some cases even more, example [wi-fi](_URL_0_). All of that without sacrificing the utility of the pickup. ",
"I had a truck for a few years and I absolutely loved it! I was in college and constantly moving so it was very useful to have a truck, and also helped out a lot of friends that didn't have trucks and they appreciated it.\n\n I also live in the Midwest where we get a few snow storms a year (this year once a week...blah). I would often go out in these storms and help dig people out of snow drifts. Most of those I could just drive over due to the clearance trucks have compare to cars.\n\nTrucks are very useful and powerful. The reason I had to sell was mostly financial due to it being expensive to fill up.",
"Its marketing along with some practicality. I live in the south, but I live in a bigger city. A ton of people drive large trucks who never would use them for anything other than making themselves feel more manly/country. It kind of signifies their own identity with their subculture of rural even if they live in the suburbs and have never even slept outside before.\n\nI personally want a truck someday because it would be very convienent for my kayaking and camping hobbies.",
"My dad always told me as a kid I was a man so I need a pickup truck to haul my tools and move furniture. \n\nNow he's crippled out of work and drives a sedan. ",
"Although I'm Canadian, I'm sure it's quire similar. I use my pickup truck all the time, generally to throw my hockey equipment in the back because it is way easier than using a car, especially when you're driving other people. We also do a lot of outdoorsy activities. Pickup trucks are great when your camping, hauling trailers, or bringing along your skiis or mountain bikes for a long weekend. Again, much easier when traveling with others as it frees up the cab.",
"We have fewer panel vans though. Here, pickup trucks are used for working the way that vans are used in Europe, from what I understand. My family has always had a pickup, because we lived in a rural area and we used it for towing and hauling. Why people in the cities drive them, I have no idea. ",
"Pickup trucks: for Central Americans, too! We use ours to get to the house (long offroad driveway requires 4x4) to haul our coffee harvest for drying, to haul it back from drying, to haul around tour indigenous workforce when they want to go somewhere, to drag trees out of the jungle and then carry big pieces of them to the mill, and of course to offroad up and down the beaches on weekends! we have a '91 lifted hilux and that thing is unstoppable! also, its an easy truck to work on and find parts for. i guess you were talking about the united states but america is two whole continents, not a country... From Mexico to Patagonia, pickups are a really reasonable choice too.",
"American here:\nMy wife and I each have a vehicle. Her car is a VW micromachine with awesome mileage and absurd reliability. My truck is a mid size Dodge. Each vehicle has its purposes. The truck allows for moving large things. I dont have to go through the hassle of renting a truck or trailer just to move a table and chairs, bed, couch, ect. Also I do a lot of woodworking and often have to bring home large pieces of wood and that is only possible with a truck. \n\nI have a short commute so its not a big deal to drive my truck to work but anytime I have a considerable distance to drive, I will always drive the car. Pretty much any driving that is not part of our normal routine is done with the car.",
"You can carry stuff in them. Want a free couch. Lots of people will give one to you just to haul it off because they don't have access to a truck. They come in handy a lot.",
"Here in Maine and other New England states people drive pickups for any number of reasons - some use them very little as an actual utility vehicle and are really just buying into the market hype, however, most people have many uses for their pickup, including but not limited to:\n\n1. Hauling (trailer: boat, lawnmower, 4wheeler, snowmobile, etc)\n2. Snow plowing\n3. Moving cut brush to the dump/transfer station or cord wood to your house/camp.\n4. Hauling loam/soil from the garden center to your house/property for landscaping.\n5. Getting into places you wouldn't normally be able to get into in a lower vehicle, like a car, or one without 4x4. There are people outside of town who have some pretty hellacious driveways/access roads.\n6. Camping gear (bikes/tents/stoves/firewood/etc)\n7. Muddin'\n\nMost of the 'hauling' above you wouldn't want to do in a station wagon or even an SUV cause you'd constantly be getting the interior dirty. A pickup bed you can just hose down and sweep out.\n\nSome of the smaller more reasonable pickups get fairly decent mileage.. depends on make/model.",
"There are generally two schools of thought on pick-up trucks in the US. The first one being a utility vehicle that, for many, is part of your livelihood. It represents hard work that you do yourself and rugged manliness. The second school of thought plays off of the first and uses that rugged manliness to show off. These people never use their trucks for work, but instead it is more of an extension of their ego. These trucks are very well cared for and often have expensive wheel rims or some such thing to get attention. There are many women who actually find this to be a turn on (which is why people sing about them).",
"I live in Rural NY AND commute (in a civic ) to a city for work. 90% of truck owners I have met have second jobs that pretty much require them, snow plowing, leaf blowing, landscaping in general, roofing, construction etc, they may not do all of those things year round but you will be hard pressed to find someone that owns a truck and doesn't use it for it's utility. Owning a truck just because it is big is a thing of the past - if it was ever anything but a stereotype to begin with.",
"I'm a farmer in Canada and I drive a pickup for two reasons. \n\n1: I frequently have stuff to load in the back. Bags of feed, lumber, hay, tools, tractor tires.\n\n2: Trucks are higher off the ground and come in four wheel drive which is very necessary for getting from the road to the house in the winter. My lane is 400m long with a fairly steep hill in it. A car wouldn't make it from December to March.",
"According to my dad: If you can only afford to have one vehicle, it ought to be a truck. If you can afford more than one vehicle, at least one of them ought to be a truck.",
"American here. I drive a car, but really wish I drove a truck. I hunt deer. It's rather hard to try and transport a deer in a car.",
"You can carry shit And take it anywhere on any terrain it's not that hard to figure out. ",
"I cannot speak for people with full size trucks, but for the smaller trucks, I can say----[easy to modify, easy to work on, parts are cheap for most things, you can haul things, play in the mud, shine them up in no time, and just generally all around fun!!!](_URL_0_) Cheers!",
"Because \"truck nuts\" look silly on a sedan.",
"I'd rather be in a situation where I have a pickup truck and don't need it vice needing one and not having it. Either way, I'm going to commute from point A to B. I guess it's just the utilitarian in me.",
"In warm climates, pick-ups are the new station wagon. ",
"Trucks are generally nice to drive, have good power, can haul stuff, are 4wd, higher up so you can see better, are better built then car's. They are safe in crashes, and have a lot to like. Trade off is you burn more gas. "
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3qy3c4 | how do musicians interpret the conductor's arm/baton movements as specific instructions for their particular contribution? is there some sort of known movement to scale extrapolation or musical empathy or even him just being there for show? | Obviously, I am not musical at all but I've always wondered how the mechanics of conducting work. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3qy3c4/eli5_how_do_musicians_interpret_the_conductors/ | {
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"This is a hard one to explain. But basically the conductor's movements really tells the band how to play.\n\nAs you get more and more advanced in your playing the conductor becomes less useful in telling you the time signature and beat of the music and more useful in keeping everybody in line and telling everybody what to emphasize and what not to emphasize.. What I mean is that in high school your conductor really works hard to keep everybody in time and help the band members hit their cues... but when you hit the professional level everybody knows how to keep time and everybody knows when they are supposed to play.\n\nSo the conductor kinda sorta helps people know when they are supposed to come in and whatnot... but really the conductor helps the performance take shape into something meaningful. On the surface his job is to keep people going at 120 bpm's through a specific part.... but in actuality he calls for certain parts to be louder or softer... he emphasizes certain parts as they need to be emphasized... with simple movements he can make the band become louder or softer... or move faster or slower regardless of what the music says. Ultimately the band members respond to the conductor... if the conductor motions for a certain part to play louder, that part will play louder even if the sheet music says to play softer. The conductor is the final say in the interpretation in how the music is expressed.",
"The conductor works in combination with the (perhaps memorized) sheet music; you can't play a symphony with just a conductor. \n\nHe acts to coordinate and harmonize the sections. Every musician can see that they have to play such and such note at such and such time, but they will tend to be unsynchronized slightly if they are just playing on their own. The conductor's movements provide a common baseline for timing that keeps the orchestra playing together. His movements do have a widely understood set of meanings regarding timing, volume, etc., so the musicians are getting more information from him than you are.\n\nYou may have seen some people playing music individually with the aid of a metronome, which provides beats at pre-set intervals. That ensures that musician's timing stays the same throughout the piece, so that the fast sections and slow sections are just as fast and slow (relative to each other) as the composer intended. That's one of the functions a conductor provides for the orchestra."
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5ukjrc | how do knife/tomahawk throwers know that the head of the axe/knife is going to hit their target? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ukjrc/eli5_how_do_knifetomahawk_throwers_know_that_the/ | {
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"Theres a technique to it. They adjust how fast they spin the blade for different distances. It takes a looot of practice.",
"I took an axe throwing class last summer.\n\nA well thrown axe always revolves a certain number of times when thrown a specific distance with a specific amount of force. By practicing different types of throws from these specific distances, an experienced thrower can make every throw land.\n\nDifferent distances require different throw types, based on the number of revolutions. For example, when I stood at around 7 paces from the target, I could throw with the axe head facing forward (the axe would make one revolution and land handle down). When I moved to around 12, I had to throw with the axe head facing backwards, because it went throw 1.5 revolutions from that distance (the axe would land with the handle facing up).\n\nHitting consistently from further than that (the two revolution distance, I never moved beyond that) was hard.",
"Unlike in a lot of tv and movies, the technique is to have it make 1 revolution. Making 1 slow revolution gives you more leeway than multiple fast spins. With 1 slow revolution, if you're off by a bit, you'll still hit with the head (just not perfectly). With multiple fast revolutions, if you're off by a bit, you'll hit with the handle (if at all). The rest is just judging distances and practice. "
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kdeib | the pumping lemma | _URL_0_ | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/kdeib/eli5_the_pumping_lemma/ | {
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"For a handful of academic fields and topics (such as computer science, compilers, etc.), there's a fundamental need to know if languages are called *regular*. The languages aren't languages like English, French, German, etc. The languages are simply languages along the lines of more computerish languages. For example, a simple kind of language could be described as: \"Any number of 0s followed by any number of 1s\". And if this language is *regular*, then you can easily build an extremely straightforward machine that can say \"Yes, the word you gave me exists in the language you defined.\" So for example, if I created the word 0001111111, I would want to know if it's in my language I described earlier. I could stick it in my machine, and it would say, yes, it's in the language. Or perhaps the word contains a billion 0s followed by a trillion 1s. I could feed it into my mechanical machine, and it would say \"Yep, that's also in the language.\" The machine is built so it can say \"Yep, in my language\" to *all possible words in the language*. (If you know anything about computers, these machines are literally machines without any kind of RAM or cache or memory whatsoever. Almost cog-like machines.) \n\nMost languages though aren't as simple as saying \"Any number of 0s followed by any number of 1s\". Sometimes they start introducing new concepts, like \"Start with any number of 0s. Then you must end with exactly the same amount of 1s as you had 0s. I call my language MIRROR!\" You wonder, \"Is that MIRROR language regular?\" Or in other words \"Can I build one of those simple machines to see if it can recognize all possible input words as being in MIRROR?\" It turns out for this language, the answer is NO. Those simple machines don't work. No machine can be built which recognizes all words in MIRROR. Well, why? How can we know? Do we start trying to build a machine, then after several hours we give up and conclude it can't be done because we can't figure out a way to do it? \n\nThis is where the Pumping Lemma comes in. It's a nice little tool that can be used to tell if a language is NOT regular. Normally the Pumping Lemma sounds boring and bland. \"First, start with a regular language. Choose some middle part of a word in that language. Then repeat it a bunch, then the new word you create will still be in the language.\" \n\nOk...so...why is that helpful...that sounds really...useless. But wait! What if you get creative with logic and realize this: \"There's a way to find irregular languages. If I choose some middle part of a word, repeat it, and thus create a new word out of it, and that word isn't in my language, then I'm doing good. If I choose some other middle part of the word, repeat it, and the also isn't in my language, then it's looking irregular. Now we don't know if it's irregular just yet. But we're getting close. We have to show that there is no possible choice of middle parts that when repeated, is still in the language.\" For example, find a word in that MIRROR language I described earlier (I'll pick the word 0011), take some middle part (the 2nd zero), repeat it a bunch (I'll repeat that zero five times), piece together that result (0 + 00000 + 11 = 00000011), then ask, is 00000011 in the language MIRROR? (nope!).. Ok, it's looking irregular, but we're not sure yet. Lets try picking 1 for some middle part. Repeat that 1 a bunch. 001111111. Is it still in the language? Nope, more 1s than 0s, that breaks the rule of MIRROR. Ok, how about we pick 01 for the middle part, and repeat that a bunch? Nope, now it's not in MIRROR anymore, it's something like 000000101010111111. Well, is there *any* middle part we can choose, repeat it, and it's still in the language? Nope. So, my language is not regular. Nifty! It might sound hard or complicated, but it's by far the quickest and easiest way to rule out most languages as being non-regular. \n\nNow, the pumping lemma comes in two parts, a weak form, and a strong form. I've explained the weak form. Here's the basic idea of the weak form. If you can pump a language, and the resulting word is still in the language, that's obnoxious. You should get upset if a choice for the middle pumps and the word is still in the language, because it doesn't tell you anything. All infinite *regular* languages pump, but so do some infinite *irregular* languages. So pumping correctly doesn't tell you if it's regular or irregular. But not pumping gives you hope. Not pumping for a choice of the middle part isn't proof it's irregular. It gives you hope, but not proof. Not pumping for another choice of the middle part isn't proof, just more hope. Only if you exhaust all possibilities for the middle part, and show none of them pump correctly, can you say it's irregular. Because we know *all infinite regular* languages has some middle choice that pumps, so if some language has no middle choice that pumps, then that language must be irregular. \n\nSo, if some middle choice pumps, you should initially upset. Because the weak form of the pumping lemma doesn't tell you if it's regular or irregular. But we haven't lost hope yet. The strong form of the pumping lemma can help here. It's an extra set of restrictions on the pumping lemma which helps out. I won't go into the restrictions here, but the overall idea is the same. Pumping correctly tells you nothing. Not being able to pump all possible middle choice tells you it's irregular. \n\nSide note: Usually the pumping lemma is a great way to start asking \"Well, how do we build machines which can work with any kind of word in MIRROR?\" And the answer to that is your machine has to start remembering values, which requires some kind RAM-like mechanical memory, which lead into more theoretical ideas. \n \nAnother side note: You might start asking \"What the hell is this theory crap even being discussed? It's so theoretical and useless.\" Wrong, you moron! Theory like this is how we can help make computer languages and build compilers for programs. Or how people started making logical steps to design memory, and then logical computer languages. This meant instead of building boring old machines like washing machines, we could start building things like computers which can process algorithms and other computer programs. ",
"I assume you know what the pumping lemma (for regular languages) states and are looking for some intuition behind why it is true and how it can be used. If this was not your quandary, please clarify. Any questions you may have I would be happy (attempt) to answer.\n\n***\n\nRemember that each regular language has a finite-state machine that decides it. Now consider all words that are longer than the number of states in that machine. What happens when you run the machine on one such word word? Well since there are more letters than states, you'll pass through at least one state at least twice (this is known as the [pigeonhole principle](_URL_0_)). Imagine what happens between those two occurrences. The sequence of words is such that the machine is lead in a circle, ending where it once was - this subsequence has no effect on whether the word will or will not be accepted at the end. In fact if you were to skip that sequence you'd reach the same result at the end as if you hadn't. On the other hand, you can repeat this sequence as many times as you want and it will never change the result. \nWhile the pumping lemma does not contain anything about finite-state machines in its statement, this is its meaning. All words that belong to the language and are long enough can be written as xyz, where y would be the looping subword I wrote about above and the words xz, xyyz, xyyyz, xyyyyz, ..., xy^i z, ... where i is any non-negative integer are also members of the language.\n\n\n***\n\n\nThe pumping lemma is often used to prove that a certain language is *not* regular. Consider again what it says: \nIf \nL is a regular language, \nthen \n*there exists* an n > = 1, such that \n*for each* string w in L longer than n, \n*there exist* strings x, y, z with w = xyz, |y| > 0, and |xy| < = n, such that \n*for each* i > = 0, such that xy^i z ∈ L.\n\nWhat is the contrapositive of that? (The following may go over your head if you are not familiar with at least some logic. If that's the case, just take my word that it is equivalent to the above statement.)\n\nIf \n*for each* n > = 1 \n*there exists* a string w in L longer than n, such that\n*for any* strings x, y, z with w = xyz, |y| > 0 and |xy| < = n\n*there exists* an i > = 0, such that xy^i z ∉ L, \nthen \nL is not a regular language.\n\nApplying the lemma correctly can be subtle. It is often useful to think of the application of this result as a *game* between yourself, the prover, who is striving to establish that the given language L is not regular, and an adversary who is insisting that L is regular. The theorem states that, once L has been fixed, the adversary must start by providing a number n; then you come up with a string w in the language that is longer than n; the adversary must now supply an appropriate decomposition of w into xyz; and, finally, you triumphantly point out i for which xy^i z is not in the language. If you have a strategy that always wins, no matter how brilliantly the adversary plays, then you have established that L is not regular.\n\n\n\n\nExamples:\n\n1. Consider the language L = {a^i b^i | i > = 0}. Let n be any positive integer. Consider then the string w = a^n b^n ∈ L. By the lemma, it can be rewritten as w = xyz such that |xy| < = n and |y| > 0 — that is, y = a^i for some i > 0. But then xz = a^n-i b^n ∉ L. It follows from the pumping lemma that L is not a regular language.\n\n2. The language L = {a^n | n is prime} is not regular. For suppose it were, and let x, y, and z be as specified in the lemma. Then x = a^p , y = a^q , and z = a^r , where p, r > = 0 and q > 0. By the lemma, xy^n z ∈ L for each n > = 0; that is, p + nq + r is prime for each n > = 0. But this is impossible; for let n = p + 2q + r + 2; then p + nq + r = p + (p + 2q + r + 2)q + r = p + (p + 2q + r)q + 2q + r = (q + 1)(p + 2q + r), which is a product of two natural numbers, each greater than 1.\n\n***\n\n\"Elements of the Theory of Computation\", by Harry R. Lewis and Christor H. Papadimitriou was used as a reference and is an excellent introductory textbook to the subject.",
"For a handful of academic fields and topics (such as computer science, compilers, etc.), there's a fundamental need to know if languages are called *regular*. The languages aren't languages like English, French, German, etc. The languages are simply languages along the lines of more computerish languages. For example, a simple kind of language could be described as: \"Any number of 0s followed by any number of 1s\". And if this language is *regular*, then you can easily build an extremely straightforward machine that can say \"Yes, the word you gave me exists in the language you defined.\" So for example, if I created the word 0001111111, I would want to know if it's in my language I described earlier. I could stick it in my machine, and it would say, yes, it's in the language. Or perhaps the word contains a billion 0s followed by a trillion 1s. I could feed it into my mechanical machine, and it would say \"Yep, that's also in the language.\" The machine is built so it can say \"Yep, in my language\" to *all possible words in the language*. (If you know anything about computers, these machines are literally machines without any kind of RAM or cache or memory whatsoever. Almost cog-like machines.) \n\nMost languages though aren't as simple as saying \"Any number of 0s followed by any number of 1s\". Sometimes they start introducing new concepts, like \"Start with any number of 0s. Then you must end with exactly the same amount of 1s as you had 0s. I call my language MIRROR!\" You wonder, \"Is that MIRROR language regular?\" Or in other words \"Can I build one of those simple machines to see if it can recognize all possible input words as being in MIRROR?\" It turns out for this language, the answer is NO. Those simple machines don't work. No machine can be built which recognizes all words in MIRROR. Well, why? How can we know? Do we start trying to build a machine, then after several hours we give up and conclude it can't be done because we can't figure out a way to do it? \n\nThis is where the Pumping Lemma comes in. It's a nice little tool that can be used to tell if a language is NOT regular. Normally the Pumping Lemma sounds boring and bland. \"First, start with a regular language. Choose some middle part of a word in that language. Then repeat it a bunch, then the new word you create will still be in the language.\" \n\nOk...so...why is that helpful...that sounds really...useless. But wait! What if you get creative with logic and realize this: \"There's a way to find irregular languages. If I choose some middle part of a word, repeat it, and thus create a new word out of it, and that word isn't in my language, then I'm doing good. If I choose some other middle part of the word, repeat it, and the also isn't in my language, then it's looking irregular. Now we don't know if it's irregular just yet. But we're getting close. We have to show that there is no possible choice of middle parts that when repeated, is still in the language.\" For example, find a word in that MIRROR language I described earlier (I'll pick the word 0011), take some middle part (the 2nd zero), repeat it a bunch (I'll repeat that zero five times), piece together that result (0 + 00000 + 11 = 00000011), then ask, is 00000011 in the language MIRROR? (nope!).. Ok, it's looking irregular, but we're not sure yet. Lets try picking 1 for some middle part. Repeat that 1 a bunch. 001111111. Is it still in the language? Nope, more 1s than 0s, that breaks the rule of MIRROR. Ok, how about we pick 01 for the middle part, and repeat that a bunch? Nope, now it's not in MIRROR anymore, it's something like 000000101010111111. Well, is there *any* middle part we can choose, repeat it, and it's still in the language? Nope. So, my language is not regular. Nifty! It might sound hard or complicated, but it's by far the quickest and easiest way to rule out most languages as being non-regular. \n\nNow, the pumping lemma comes in two parts, a weak form, and a strong form. I've explained the weak form. Here's the basic idea of the weak form. If you can pump a language, and the resulting word is still in the language, that's obnoxious. You should get upset if a choice for the middle pumps and the word is still in the language, because it doesn't tell you anything. All infinite *regular* languages pump, but so do some infinite *irregular* languages. So pumping correctly doesn't tell you if it's regular or irregular. But not pumping gives you hope. Not pumping for a choice of the middle part isn't proof it's irregular. It gives you hope, but not proof. Not pumping for another choice of the middle part isn't proof, just more hope. Only if you exhaust all possibilities for the middle part, and show none of them pump correctly, can you say it's irregular. Because we know *all infinite regular* languages has some middle choice that pumps, so if some language has no middle choice that pumps, then that language must be irregular. \n\nSo, if some middle choice pumps, you should initially upset. Because the weak form of the pumping lemma doesn't tell you if it's regular or irregular. But we haven't lost hope yet. The strong form of the pumping lemma can help here. It's an extra set of restrictions on the pumping lemma which helps out. I won't go into the restrictions here, but the overall idea is the same. Pumping correctly tells you nothing. Not being able to pump all possible middle choice tells you it's irregular. \n\nSide note: Usually the pumping lemma is a great way to start asking \"Well, how do we build machines which can work with any kind of word in MIRROR?\" And the answer to that is your machine has to start remembering values, which requires some kind RAM-like mechanical memory, which lead into more theoretical ideas. \n \nAnother side note: You might start asking \"What the hell is this theory crap even being discussed? It's so theoretical and useless.\" Wrong, you moron! Theory like this is how we can help make computer languages and build compilers for programs. Or how people started making logical steps to design memory, and then logical computer languages. This meant instead of building boring old machines like washing machines, we could start building things like computers which can process algorithms and other computer programs. ",
"I assume you know what the pumping lemma (for regular languages) states and are looking for some intuition behind why it is true and how it can be used. If this was not your quandary, please clarify. Any questions you may have I would be happy (attempt) to answer.\n\n***\n\nRemember that each regular language has a finite-state machine that decides it. Now consider all words that are longer than the number of states in that machine. What happens when you run the machine on one such word word? Well since there are more letters than states, you'll pass through at least one state at least twice (this is known as the [pigeonhole principle](_URL_0_)). Imagine what happens between those two occurrences. The sequence of words is such that the machine is lead in a circle, ending where it once was - this subsequence has no effect on whether the word will or will not be accepted at the end. In fact if you were to skip that sequence you'd reach the same result at the end as if you hadn't. On the other hand, you can repeat this sequence as many times as you want and it will never change the result. \nWhile the pumping lemma does not contain anything about finite-state machines in its statement, this is its meaning. All words that belong to the language and are long enough can be written as xyz, where y would be the looping subword I wrote about above and the words xz, xyyz, xyyyz, xyyyyz, ..., xy^i z, ... where i is any non-negative integer are also members of the language.\n\n\n***\n\n\nThe pumping lemma is often used to prove that a certain language is *not* regular. Consider again what it says: \nIf \nL is a regular language, \nthen \n*there exists* an n > = 1, such that \n*for each* string w in L longer than n, \n*there exist* strings x, y, z with w = xyz, |y| > 0, and |xy| < = n, such that \n*for each* i > = 0, such that xy^i z ∈ L.\n\nWhat is the contrapositive of that? (The following may go over your head if you are not familiar with at least some logic. If that's the case, just take my word that it is equivalent to the above statement.)\n\nIf \n*for each* n > = 1 \n*there exists* a string w in L longer than n, such that\n*for any* strings x, y, z with w = xyz, |y| > 0 and |xy| < = n\n*there exists* an i > = 0, such that xy^i z ∉ L, \nthen \nL is not a regular language.\n\nApplying the lemma correctly can be subtle. It is often useful to think of the application of this result as a *game* between yourself, the prover, who is striving to establish that the given language L is not regular, and an adversary who is insisting that L is regular. The theorem states that, once L has been fixed, the adversary must start by providing a number n; then you come up with a string w in the language that is longer than n; the adversary must now supply an appropriate decomposition of w into xyz; and, finally, you triumphantly point out i for which xy^i z is not in the language. If you have a strategy that always wins, no matter how brilliantly the adversary plays, then you have established that L is not regular.\n\n\n\n\nExamples:\n\n1. Consider the language L = {a^i b^i | i > = 0}. Let n be any positive integer. Consider then the string w = a^n b^n ∈ L. By the lemma, it can be rewritten as w = xyz such that |xy| < = n and |y| > 0 — that is, y = a^i for some i > 0. But then xz = a^n-i b^n ∉ L. It follows from the pumping lemma that L is not a regular language.\n\n2. The language L = {a^n | n is prime} is not regular. For suppose it were, and let x, y, and z be as specified in the lemma. Then x = a^p , y = a^q , and z = a^r , where p, r > = 0 and q > 0. By the lemma, xy^n z ∈ L for each n > = 0; that is, p + nq + r is prime for each n > = 0. But this is impossible; for let n = p + 2q + r + 2; then p + nq + r = p + (p + 2q + r + 2)q + r = p + (p + 2q + r)q + 2q + r = (q + 1)(p + 2q + r), which is a product of two natural numbers, each greater than 1.\n\n***\n\n\"Elements of the Theory of Computation\", by Harry R. Lewis and Christor H. Papadimitriou was used as a reference and is an excellent introductory textbook to the subject."
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b5m8vl | why are a lot of old games (halo, wow classic, etc.) starting to re surge and be re released after 10+ years from when they were made? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b5m8vl/eli5_why_are_a_lot_of_old_games_halo_wow_classic/ | {
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"It's easy money for game companies and the companies that own them to have them rerelease games with a few gimmicks added in order to make more money for other projects. Or just more money for money's sake. \n\nIt's a way to prey on the nostalgia of past generations while attempting to get new generations hooked in attempts to possibly reboot a series or add to it. \n",
"Nostalgia tends to work on a decade cycle. \nThere's a grown up now who remembers playing Halo, etc as a kid. \nThat grown up now has free money he can spend however he wants. \nSo he remembers having fun as a kid, and the companies give him the same thing he played as a kid just updated. \nSo the grown up has fun, and the company makes money. "
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5b0i6u | why do different people like different climates? | For example I love humidity and would rather be warm/hot than too cold, but I know that some people hate humidity and would much rather be too cold than warm or too hot. Why are some climates more comfortable to some than others? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5b0i6u/eli5_why_do_different_people_like_different/ | {
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"I live in the Las Vegas Valley and chances are if you lived here long enough you grew a tolerance to heat, went to Norwalk (east of los angeles) and I was FREEZING. \n\nAfter long periods of time we get used to the temperatures in our enviroment, the same way early humans adopted to breathing atmospheric oxygen."
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6qtdax | what makes 70mm film screenings different? (i.e. dunkirk) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6qtdax/eli5_what_makes_70mm_film_screenings_different_ie/ | {
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"In terms of color and dynamic-range digital sensors come close to the performance of film. However in terms of resolution, digital is nowhere near film. 70mm has a resolution of about 18,000 horizontal lines. For reference 4K is 3840 and HD is 1920. [This image](_URL_0_) gives a visual comparison of various sensor sizes, the largest digital video sensor sold today is the RED Dragon 8K shown in red.",
"For one, it's not a digital projection. Most movies you go see in a theater are projected digitally, but if you had gone 15 or so years ago, they would have all been projected with film. There is an ongoing debate about which is better. Digital tends to show a cleaner picture, but the detail is limited to a certain resolution and film tends to have richer colors and blacks, but with some minor imperfections in the picture. It's sort of similar to the debates about whether sound quality is better on vinyl records than it is on digital files. \n\nAnyway, if you had gone to see a movie back in the day, in most cases it was on 35mm film. Dunkirk is being shown on some screens in 70mm film which means that the individual frames are larger and thus have more detail. "
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5uvu9z | across different western languages, why are there names that share an obvious common root while the languages don't? | Names such as Nikolai, Josef, or Mikhail are all recognizable to an English speaker. However, Russian and English don't stem from the same language. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5uvu9z/eli5_across_different_western_languages_why_are/ | {
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"Russian and English both belong to the Indo-European family. But that's actually not the reason, since you have Hungarian, which is not Indo-European, and has recognizable names ─ Miklós, Jószef, Mihály.\n\nThe real reason is shared heritage/culture. All European countries are, or have been in the past, heavily Christian. Christianity has this shared list of names, usually from saints or Biblical figures, that end up being translated into basically every language.\n\nUltimately, most of these names are of Hebrew origin (Joseph and Michael, in your example) or of Greek origin (like Nicholas), with some of Latin origin (e.g. Mark).",
"Almost all of the names we think of as \"shared\" are biblically derived. Hence they appear in cultures where Christianity has exerted influence. Most notable is that they don't appear in those cultures UNTIL the arrival of a Judeo-Christian influence. ",
"Actually, all European languages (except Basque, Finnish, Estonian, and Hungarian) *do* stem from the same language called Proto-Indo-European."
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9cqxll | why do rocks seem to be dull and colorless when dry but explode with color and character when they’re wet? | I have a rock collection but they they suck when they’re dry. So when I show people (anyone who will lol) I dunk them in water first but I don’t know why water makes them more vibrant as I don’t see this in other objects. You might say it’s because of dust but this isn’t true because I get them wet, then they dry and become colorless without getting dusty (unless that dust is rock-seeking or something). | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9cqxll/eli5_why_do_rocks_seem_to_be_dull_and_colorless/ | {
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"Several reasons, the major one at play is that it changes how the light reflects off the surface. It consolidates the light and allows it to be seen from one direction. The water also creates a new smoother surface that is shinier bc it allows all the light to shine off of it. Source _URL_0_",
"It's to do with the smoothness of the surface. When they're dry the surface is more irregular so light reflecting is scattered more. When wet, the surface tension of the water provides a smoother more uniform surface, reflecting light more consistently which makes the colours appear more vividly. \nA good habit is to put a thin layer of a clear varnish on rocks you like, to highlight the colours. This also stops certain types of stone from degrading and producing dust, meaning they aren't creating mess.",
"The other option is a rock tumbler. It’s an especially good solution if you hate your housemates and/or neighbors. (They loud)",
"When the rock gets wet the water changes the angle of the light. This makes the rock look different. (Also, it may be cool to put them in waterfall fountain and display)",
"It has to do with how light reflects off the surface of the material, this applies to everything, not just rocks. (Have some experience in fine metal work in jewellery as well as lapidary work)\n\nUnder a microscope the surface is very rough and contains a lot of irregular peaks and valleys. This causes light to bounce off in different directions and scatter. Light = colour\n\nDipping a rock in water makes it wet, and since water likes to cling (it's cohesive) it fills up all the gaps to simulate a smooth surface.\nThe more smooth the surface, the more uniformly the light bounces back to your eyes so it appears more vibrant.\n\nInterestingly, the process of jewellery making (as well as stone polishing for jewellery) is all about \"smoothing\" out the surface of various materials so it has an appealing and consistent look. Often we even alter the finish of parts of objects to create contrast, such as how there are matte finish links in watches so the polished parts stand out more.\n\nGemstones have an added layer because they are transparent and take advantage of light passing through, but the basic principles still apply.\n\n\n\ntldr : the surface of objects are rough on a microscopic level and that causes light to scatter instead of bounce back to your eyes, water smooths out that scatter and makes the surface more consistent",
"This is due at least as much to refraction as reflection I think. A normal rock is usually translucent to some degree, but the boundary between it and the air is rough, at least at a zoomed-in level. Because of that AND the fact that it's a significant density transition (air= > stone) light gets refracted randomly inside the rock, obscuring interior detail and giving a dull appearance.\n\nWhen you wet the rock, now you have two boundaries; air= > water and water= > stone. The air= > water boundary is a big density jump, but it's smooth, so refraction happens there but it isn't random. The water= > stone boundary is rough, but isn't a big density jump, so any random refraction is minimized, and for those moments you get to see the interior crystalline structure of the stone.",
"Rocks touch rocks, which scratch pretty rocks till they look bland and boring. When water fills the scratches is creates a smooth surface and allows you to see the \"polished\" look of the rock. Same thing would happen on a car with a shallow scratch that doesn't penetrate the clear coat. It looks unscratched when you put water on it, but once it dries the scratch appears again."
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barw4q | why are shows with fake laughter so succesful? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/barw4q/eli5_why_are_shows_with_fake_laughter_so_succesful/ | {
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"Laughter, like yawning, can be an \"Infectious\" reaction. We hear it, and there is often a compulsion to join in, and that in turn can trick some people into thinking something is funnier than it might have been if just dropped as a line on it's own. ",
"It allows the viewer to become completely passive and not have to think about whether a joke was funny or not. You laugh because others are laughing. The other issue with laugh tracks is that there has to be a joke or \"zinger\" every few seconds to keep the live audience engaged (or the laugh track). \n\nI, too, prefer shows like 30 Rock and AP Bio where there isn't a laugh track or live studio audience. ",
"The entirety of the big bang theory is recorded in front of a live studio audience and doesn't use canned laughter, so at least in the case of this show, you clearly have a different sense of humour to other people, because some people enjoy it. For other shows it might vary, but for this one at least, you just have a different sense of humour."
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sahoy | why are truly random numbers significantly advantageous to pseudorandom numbers? | I understand the way that truly random and pseudorandom numbers differ (for what it's worth, [there's a good explanation here](_URL_0_)) and how difficult it is to generate truly random numbers, but why do people value true randomization?
For instance, [cbswe commented that truly random numbers are often sold online](_URL_1_). But I can only think of a few disciplines, like cryptography on a massive scale, where they can come in handy. In other fields, why do they hold a significant advantage to the use of pseudorandom numbers?
In other words, since they seem to not be significantly different from pseudorandomization in the majority of circumstances, how large is the demand for numbers with a higher strength of randomization, and who is comprised in this demand? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/sahoy/why_are_truly_random_numbers_significantly/ | {
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"As you noted, the biggest value is in cryptography, where non-randomness can be exploited to break ciphers. The only other place I can think of is when doing Monte Carlo simulations. Using pseudo-random numbers could skew the results undesirably, although just running more sets would likely make that a negligable effect. ",
"That part about selling random numbers online was a joke. Hardware RNGs are cheap, and having someone else generate your random numbers and send them over the internet would defeat the purpose of having secure RNG in the first place.\n\nGood pseudo random generators (called cryptographically secure) produce a sequence of numbers that is not in practice distinguishable from truly random sequence. This means that for all practical purposes those numbers are as good as truly random numbers.\n\nHowever, pseudo random generators still need a truly random seed for them to be secure. Here is why it is important: let's say you are generating a 128-bit encryption key using a pseudo RNG. You might think that your key is secure because there are 2^128 possible encryption keys and it cannot be broken in a billion years. However, if your pseudo RNG uses current second as a seed, there are only 86400 different keys it can produce in a given day! Suddenly, the encryption key becomes absolutely insecure. \n\nThus, one of the main uses of hardware RNG is generating truly random encryption keys. This is why if you used TrueCrypt it asks you to randomly move your mouse when generating a new encrypted disk - it uses YOU as a hardware RNG :)\n",
"I am officially selling random numbers now. \n13! (the first one's free)",
"Do \"true\" random numbers actually exist? I don't think so. There's always some kind of underlying process which chose those numbers. Whether it can be measured or repeated is another thing, but something chose them.",
"There's both proven (and some inexplicable) benefits to true random numbers, over all others. The proven benefits exist in things like cryptography and the statistical and experimental sciences, and save money, generate profits, and help secure communications for many entities across the board. That's why true randomness is so eagerly sought after, by so many.\n\nBut then there's also the inexplicable side. Here's an example: I wrote a piece of software decades back integrating the I Ching, Art of War, and Tao of Power into one package, and the heart of that package was the best random number generator I could personally devise. Basically when a user would type in a question (the app answered questions), the program would get its random numbers from the time elapsed between individual keystokes (resulting in either an even or odd number). As the computer could do a counting loop much faster than the user could type, the result could be something like 20,093, or 1440, or whatever. The app would simply note the odd or evenness of the number for a random binary result. Even the fastest typist couldn't skew the random selection via speed. And the user's thought processes, as well as physical actions and environmental circumstances would all play a role too, in the outcome. \n\nAnyway, you could see a huge difference in the quality of the answers given, based on using this method, as opposed to using the routine random number offering from the computer's own functions. To me and others, my app often seemed eerily self-aware, using my method.\n\nThis was never more apparent than the last time I personally used the program. I created it for ancient Macs, many years ago, and was unable to update it for later models for various reasons. I used the program a lot to boost my brainstorming creativity for projects, as that seemed to be one of its strengths. So I kept an ancient Mac running long past its era, in order to maintain access to this and a few other choice apps.\n\nHowever, the ancient Mac couldn't last forever, and one day when I was using my app, it suddenly interrupted our normal interaction with a bizarre statement which made no sense to me in that moment. The app informed me it couldn't answer my latest question, because it (the app) had been corrupted. Just as I was about to type in another question for more information about this, an awful noise emanated from my Mac's hard drive, and the Mac crashed (the hard drive had died).\n\nI know this might sound over the top in regards to random numbers. But I'm not the only one who thinks this way. In one of the last Whole Earth Catalogs published decades back, a well respected man said something about true randomness being deserving of being treated as a Holy among Holies in human endeavor (I don't have the exact quote handy).\n\nI hope someday to resurrect my app from the dead, for I surely miss it."
]
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"http://www.reddit.com/r/science/comments/s9k51/researchers_have_developed_the_fastest_random/c4cc1m4",
"http://www.reddit.com/r/science/comments/s9k51/researchers_have_developed_the_fastest_random/c4c8ndd"
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5ojw8m | what actually happens when you get frostbite if there is no chance of saving the body part? does the whole thing - including the bone - simply break off? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ojw8m/eli5_what_actually_happens_when_you_get_frostbite/ | {
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"Your cells are mostly water. When water freezes, it expands, effectively killing the cells even if they thaw out. Your body can replace a few damaged or dead cells, but as the affected region grows larger, it destroys all the pathways the body uses to remove and replace the cells. Thus the whole region because a large set of dead cells which can have the potential of becoming gangrenous if not cut off.",
"No, the bone doesn't break off. The flesh clings on, and rots, leading to a possibly fatal infection called gangrene. To prevent this, the flesh must be cut off. The protruding bone is typically then removed with a saw, so that the skin can be sutured shut.",
"If you are lucky the deed tissue will just die off and the live tissue will start forming scar tissue towards the dead tissue. Eventually the dead tissue will fall off and rot away. However in most cases there will be some interaction between the live and dead tissue before this. The problem is that the dead tissue starts to rot quite fast and may cause an infection in the live tissue. This infection is usually deadly unless treated with strong antibiotics and in most cases amputation of the infected live tissue. Having dead limbs still attached is like cutting open your flesh and add rotting meat to the gaping wound to stop the bleeding."
]
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1ffx30 | how does novocaine work to numb tissue and how how/why does it wear off? | Huh? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ffx30/eli5_how_does_novocaine_work_to_numb_tissue_and/ | {
"a_id": [
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"I can give you a very large and complex answer if you change your mind. \n\nNovocaine hasn't been used in a long time. It's an eponym. \n\nIt's a sodium channel blocker. Meaning your local anesthetic gets in the way of pain signals thus blocking it. You also lose all sensation because it blocks normal signals too. \n\nSource: I'm a dentist from /r/dentistry"
]
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[]
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|
59rojk | why do medieval hoods have a "tail"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/59rojk/eli5_why_do_medieval_hoods_have_a_tail/ | {
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" they were called liripipes. Most people believe it was just a fashion trend at the time, one that was capitalized by modern artists/video games/what have you whenever they want to make something look \"medieval.\" There are a few manuscripts from around the fourteenth century in which people complain about how ridiculous the liripipes look, and speculating that soon people will be wearing hoods that hang down to their feet in back. It's kind of like old people complaining about saggy pants. "
]
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[]
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||
3hcsh6 | with no operator in sight how do railroad crossing activate? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3hcsh6/eli5_with_no_operator_in_sight_how_do_railroad/ | {
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"where I live there are sensors on the tracks a certain distance down the tracks that activate the crossing guards. I don't remember how far out they are.",
"There are sensors in both directions on the rails. It is not hard to sense a multiton engine. The sensors trigger the crossing guards. There are also devices on trains which measure the levelness of the rail and if the nails are coming out. There are sensors which check each passing truck, (the set of four wheels on each end of a car), for heat which indicates bearings needing greasing.",
"It's called an induction loop. It's the same technology that detects when there's a car at a traffic light.\n\nIt's basically a magnetic sensor. When a train is on the track, it changes the magnetic field *enormously* at that spot, and that triggers the crossing alarms."
]
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690nhq | why do we use the current signal waves for wifi even though they can get disrupted by walls? is there a better solution, if so why aren't we using it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/690nhq/eli5_why_do_we_use_the_current_signal_waves_for/ | {
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"Tl;dr it's a tradeoff of speed vs range with current technologies.\n\nDisclaimer: not an expert, or even an enthusiast. Take this with a grain of salt.\n\nWifi is a relatively high-frequency band, which means it's easily stopped by walls versus something on a much lower frequency, i.e. radio. You can boost the transmitter power, but consumer routers can only do so much.\n\nRadio doesn't have the same level of bandwidth possible with wifi because of the lower frequency. The waveform is larger, giving it a better range and penetration. Plus you need a big antenna to properly transmit it.\n\nYou may have heard of 5Ghz band wifi (normal is around 2.4Ghz), which has an even faster frequency. This does give you more speed, but even less range than normal wifi.\n\nBut your question is why are we still using wifi. The reason is that there's no widespread support of anything other than conventional wifi, and some devices don't even support the 5Ghz band.\n",
"I think there are 2 reasons for this. The first one is that you don't want your signal to be able to pass through walls indefinitely. The wifi signal can pass through a few walls before it gets too weak, which is fine for most houses. Imagine that they could pass through walls without losing signal though. You'd have insane interference in crowded areas. If you live in a city you will already notice that your wifi list probably has 20+ wifi signals incoming. If this number was 100 times higher no one would be able to properly use their wifi anymore. \n\nThe other reason is that if you did want to make signals that can pass through walls easily you'd need a bigger wavelength. Like radio waves. Those can easily pass through walls and are only stopped by tunnels. To generate such a wave you need a massive antenna though. Our routers at home are currently quite decently shaped. But imagine them being 10 times bigger. They'd be the size of your fridge. Which is also not very convenient. "
]
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[],
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||
3d2xzm | can you lock a door with a lockpick? | Just realised I have no idea whether this is possible or not, Google has not helped. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3d2xzm/eli5_can_you_lock_a_door_with_a_lockpick/ | {
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"text": [
"Yep. The same principle works, you just spin the lock the other direction once all the pins are lined up. In a tumbler lock anyway."
]
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[]
] |
|
ji24c | steroids? | I don't understand steroids. I've seen pictures of users like Barry Bonds who look a lot bigger, but what did the drug do on the inside? Just give the user more energy to life more weights, or something else? What's the advantage in sports? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ji24c/eli5_steroids/ | {
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"Steroids are chemicals that allow the user to build muscle, build it faster, and have more endurance than a normal person. They are hormones that are normally in a human body, but when used to enhance performance are present in abnormal quantities. \n\nThey don't necessarily confer more energy, but indirectly you'll be able to lift weights longer, lift heavier weights, etc. The advantage in sports is complicated; I'll use baseball as an example.\n\nSay you're a 20 HR, .270 BA, and 70 RBI hitter. Pretty good right? But that's around average...nothing stellar. Steroids allow the average player a step up. Whereas they already have the skill, obviously, steroids improves on strength. Those fly balls that stopped on the warning track? No more...they're HRs to deep center. Now our average player is getting 40 HR, hitting .300, and pounding in more than 100 RBIs a season. Quite the All-Star. There has been debate to whether steroids help pitchers, because pitchers, unlike power hitters wouldn't necessarily benefit from extra strength like they would. However, pitchers like Roger Clemens, Andy Pettitte, etc. benefit from being able to recover from injuries quicker, faster pitch speed, and other things. ",
"At some point, we realized that men seem to be more muscular than women (just in general). As it turns out, there's a chemical called testosterone that's pretty important for male development. Among other things, testosterone makes it easier for the body to make certain proteins, including the ones in muscle. Anabolic steroids \"look\" a lot like testosterone, and the body reacts to it in a similar way. As a result, steroids make it easier for someone to build muscle. Of course testosterone has a lot of other effects, including heightened aggression and body hair growth, and these symptoms appear in steroid users as well to varying extent.",
"Steroids are chemicals that allow the user to build muscle, build it faster, and have more endurance than a normal person. They are hormones that are normally in a human body, but when used to enhance performance are present in abnormal quantities. \n\nThey don't necessarily confer more energy, but indirectly you'll be able to lift weights longer, lift heavier weights, etc. The advantage in sports is complicated; I'll use baseball as an example.\n\nSay you're a 20 HR, .270 BA, and 70 RBI hitter. Pretty good right? But that's around average...nothing stellar. Steroids allow the average player a step up. Whereas they already have the skill, obviously, steroids improves on strength. Those fly balls that stopped on the warning track? No more...they're HRs to deep center. Now our average player is getting 40 HR, hitting .300, and pounding in more than 100 RBIs a season. Quite the All-Star. There has been debate to whether steroids help pitchers, because pitchers, unlike power hitters wouldn't necessarily benefit from extra strength like they would. However, pitchers like Roger Clemens, Andy Pettitte, etc. benefit from being able to recover from injuries quicker, faster pitch speed, and other things. ",
"At some point, we realized that men seem to be more muscular than women (just in general). As it turns out, there's a chemical called testosterone that's pretty important for male development. Among other things, testosterone makes it easier for the body to make certain proteins, including the ones in muscle. Anabolic steroids \"look\" a lot like testosterone, and the body reacts to it in a similar way. As a result, steroids make it easier for someone to build muscle. Of course testosterone has a lot of other effects, including heightened aggression and body hair growth, and these symptoms appear in steroid users as well to varying extent."
]
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44kmmq | why do restaurants offer various types of bread before the main course if it serves only to full us up? wouldn't this in turn make them less money? | You've had them before. Red Lobster with their cheesy biscuits, Olive Garden and their endless breadsticks, and Outback with its honey-wheat bread served with butter. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/44kmmq/eli5_why_do_restaurants_offer_various_types_of/ | {
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"To my understanding, it's cheap, it makes the patron feel like they're getting something for free - which always feels good. In addition, it keeps the customer preoccupied while busy servers and kitchen staff work to fulfill other orders. You're less likely to complain about service if you have a basket of bread in front of you. ",
"Others have said its to appease customers with a relatively cheap perk, which is absolutely true, but beyond that, its part of the brand to help attract customers. You have an olive garden and an applebees across from each other, you very well might choose to go to olive garden because you know youll get those delicious breadsticks, or maybe you go to red lobster one night just for the cheesy biscuits. Olive garden and red lobster just got $30 in sales from you and a date fot a 25 cent investment. \n\nAlso as a customer, its goddamn nice going some place and having them put some bread down before the meal without me having to pay through the nose on an appatizer. Some of my favorite restaurants are ones that include that type of thing.",
"Bread is cheap. Just like tortilla chips and salsa at Mexican restaurants. You eat these while waiting for the appetizers/entrees. Also, these items are thirst inducing, causing you to want \"one more\" glass of wine/Coke. That starts to add up over the course of a meal. Taverns do the same thing with free salty snacks like peanuts and pretzels.\n\nEdit: punctuation. ",
"It's not free, it's built into the price of the meal.\n\nIt helps you feel welcome **and** it distracts you from how long it's actually taking to get your food. Overall, this leaves you feeling like you're receiving better service.\n\nThey also know that people aren't going to order multiple entrees, so they only need to focus on selling you one."
]
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a6x2so | what causes people to become less flexible? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a6x2so/eli5_what_causes_people_to_become_less_flexible/ | {
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"Flexibility comes from our ligaments and tendons, the fibers that hold our muscles together and anchor them to our bones. Over time, they start to harden. \n\nYour genes only care about you as long as you can reproduce. There's no incentive to maintain the body past a reproductive age, so we start to deteriorate. Presbyopia is a really interesting example of this exact pattern. "
]
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[]
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||
7yjrpf | why do some recipes call for melted butter? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7yjrpf/eli5_why_do_some_recipes_call_for_melted_butter/ | {
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"Basically, when recipies call for softened butter, they use the creaming method; the sugar and butter are mixed together in such a way that the sugar cuts little air bubbles into the butter. These little bubbles can add some extra puff to the cookies.\n\nIf you melt the butter first, not only do you not have those air bubbles, but there's water in butter, so you'll end up getting some gluten development when you mix in the flour and make a chewy cookie ... but more importatly, without the fat being (near) solid, the cookie will slump a lot more, and spread out before it cooks (assuming you haven't otherwise adjusted the recipe to compensate). [source](_URL_0_) \n\n[more here](_URL_1_) ",
"Depends on what you are making. Often melted butter has a different or lesser role than when softened butter is in the recipe. A few table spoons of melted butter is a nice fatty product that aids mixing in / blending in a few ingredients, especially if only limited mixing is necessary such as in a pancake recipe. This would not work for a butter creme icing or many other things where more body is needed. "
]
} | [] | [] | [
[
"https://cooking.stackexchange.com/questions/13096/why-is-there-a-difference-between-softened-and-melted-butter-when-baking",
"https://oureverydaylife.com/softened-vs-melted-butter-baking-41737.html"
],
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] |
||
7e48r6 | why do guns that fire the same caliber of bullet have different muzzle velocities? | I'm looking at the wikipedia for the M16 and the M4 carbine. They are both listed as firing 5.56 x 45mm cartridges.
The muzzle velocity for the M16 is listed at 960 m/s.
The muzzle velocity of the M4 is listed at 910 m/s.
Is this a function of barrel length? Some other variable? My understanding was that the same cartridge would have the same amount of gunpowder, leading to the same amount of force propelling the bullet forward. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7e48r6/eli5_why_do_guns_that_fire_the_same_caliber_of/ | {
"a_id": [
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"Bullets are accelerated by the expanding hot gasses behind the bullet. If your barrel is 3 inches long, the bullet leaves the barrel before all the gas is finished pushing on the bullet.\n\nIf your barrel is 5 feet long, the gas pushes all it can and then the bullet slows down due to friction in the barrel.\n\nSomewhere in the middle is the perfect point where the expanding gas gives the bullet all the energy it can with the least energy lost to friction. \n\nThe M16 has a longer barrel, giving the bullet more speed when it exits the barrel. The M4 is shorter and more maneuverable in tight spaces, but a little bit of power is lost when you shorten the barrel."
]
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|
3b0wt7 | why is the majority of the us navy nuclear powered ships but super tankers aren't? | I saw a post the other day about the amount of pollution that super tankers and container ships produce. Wouldn't nuclear be way more efficient? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3b0wt7/eli5_why_is_the_majority_of_the_us_navy_nuclear/ | {
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"Cost. Our newest nuclear aircraft carrier cost 13 billion dollars. How many loads of cargo are you going to have to haul to make up for that? And you would first have to have 13 billion dollars or have some one finance it for you. That is just not happening. Then you would have to have a crew capable of maintaining it.",
"Its is for a few reasons. The first is that nuclear power plants are expensive. Another reasons is that the fuel used on submarines is of a higher quality then in a normal power plant in order to make it smaller. However the government won't give any of the higher quality fuel because it could make a bomb. Lastly, you would have to train the crew on what to do if something went wrong and that costs even more money.",
"Giant diesel engines are SUPER cheap to run, relatively speaking. The oil they burn is basically the leftovers from refining everything else.\n\nWarships, on the other hand, have different requirements. They need a ton of electricity and they need to be able to operate without getting refueled (as often). Nuclear is way better for that."
]
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61ig2j | what improvements in spaceflight have we made since the moonlanding? | SpaceX's reusable stage 1 landings is important, but outside of that what has actually improved in rocketry since then? Are our rockets measurably more efficient/reliable? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/61ig2j/eli5_what_improvements_in_spaceflight_have_we/ | {
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"The efficiency of engines probably didn't improve very much as there is just so much energy in chemical reactions (the same engine is planned to be used in the new NASA SLS as was with the space shuttles since the 80s). There is research into more efficient electric engines but at the moment they aren't powerful enough to move anything big (the Dawn probe used one but it weighs just around 1 ton).\n\nThe most progress probably is in automation (i.e. a trip to and from the ISS is more or less just activating the flight computer) and precision instruments. Also, super computers make it much easier to calculate trajectories.\n\nReliability was never a very large problem after the early days of figuring out rocketry and engine design were over (from '57 to '62 the success rate went from 25% to 80%) because due to the high investments everything is checked over and over and further development led to a pretty steady success rate of 96% (92.3-100%) since the beginning of the 70s. That being said most of the failures are not explosions but premature separations of stages or a failure of the control system and the sort; out of 316 manned missions 4 ended in fatalities.\n\nGenerally, space flight has just become a regular thing that is a little easier to execute although it is still not that common like planes because it's so expensive and riding a controlled explosion is a little more dangerous.",
"A big innovation in spacecraft has been [ion engines](_URL_3_), which are slow and weak but incredibly efficient. They allow spacecraft to conduct way more orbital maneuvers than would be possible with conventional engines. [JAXA's Hayabusa 2](_URL_0_) and [NASA's Dawn](_URL_2_) are spacecraft that use this technology to great effect. \n\nConventional rocket engines haven't changed much; they're quite simple and the technology was more or less mature by the Apollo program. There are some unconventional engines like [SABRE](_URL_1_), but they're not ready for use. \n\nRobotics and computers have advanced too. Our spacecraft are more and more autonomous, reducing the need for human crew. "
]
} | [] | [] | [
[],
[
"https://en.wikipedia.org/wiki/Hayabusa_2",
"https://en.wikipedia.org/wiki/SABRE_\\(rocket_engine\\)",
"https://en.wikipedia.org/wiki/Dawn_\\(spacecraft\\)",
"https://en.wikipedia.org/wiki/Ion_thruster"
]
] |
|
errbl4 | what is a super tuesday? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/errbl4/eli5_what_is_a_super_tuesday/ | {
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"Super Tuesday is a Tuesday on which a number of states hold primary elections in the United States. Many large states hold primaries on this day, and these are generally the first primaries after the 4 early primary/caucus states. It's an important day for presidential primary campaigns, because a lot of delegates are awarded, and the momentum and narrative based on the results can make or break a campaign.",
"This is better in r/askanamerican."
]
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[],
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||
3fyypc | could a hacker take over a self-driving car and cause it to redirect or crash? | I guess I'm asking if self-driving cars are controlled by on board computers or through the internet. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3fyypc/eli5_could_a_hacker_take_over_a_selfdriving_car/ | {
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"text": [
"I don't think self-driving cars will be connected to the internet unless google has another crazy idea.\n\nHowever contrary to popular belief hackers don't hack exclusively using the internet. If the car has a bluetooth or wifi network so that it can be controlled with the drivers devices then it opens a new attack vector because whoever is nearby can connect to the network and try to find vulnerabilities to gain control of the car. And even if it doesn't, someone can easily sneak into the car somehow, or social engineer the driver to get the key and plant a payload(fancy word for virus) into the board computer.\n\nFurthermore self-driving cars aren't the only ones affected. There was a [talk](_URL_0_) at DEFCON(A hacking conference) about how to mess with a car.\n\nTo give an example from that talk by tampering with the PAS(Park Assist System) of the Prius, which helps drivers parallel park, they were able to jerk the wheel, even when it's moving at high speeds. They were also able to control the steering even when the Prius wasn't in reverse, as is usually required when invoking the park assist system. They also used similar techniques to control acceleration, braking, and other critical functions, as well as to change readings displayed by speedometers, odometers, and other dashboard features."
]
} | [] | [] | [
[
"https://www.youtube.com/watch?v=MEYCU62yeYk"
]
] |
|
ejikcu | why does sand in the hourglass flow with a relatively even pace not depending on the amount of it left in the upper bulb? | I've just listened to a podcast about time. The speaker said that the flow of the sand doesn't change but if it was liquid things would be different because of its changing pressure.
Sorry if I phrased it weirdly, English isn't my first language. Feel free to correct me. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ejikcu/eli5_why_does_sand_in_the_hourglass_flow_with_a/ | {
"a_id": [
"fcy03wb",
"fcy7v5r",
"fcyeax2"
],
"score": [
6,
8,
2
],
"text": [
"I'm not so sure it does. Same shape and size opening,would ten times as much sand take ten hours? I imagine the weight on top of the sand affects the flow rate, but they volume we're working with makes it negligible.",
"Hourglasses definitely slow as they empty. You can simply visibly notice it. Not sure why you or the podcast host think they don't.",
"The key, from [your article](_URL_2_), is \"*the grains form chains and bridges that transmit their weight to the side of the container where they are supported by friction*\".\n\nAs you probably know, but it's worth thinking through: In a fluid that is almost not moving, there is no friction between the fluid and the walls. The only force between the fluid and the container walls is pressure, which is perpendicular to the surface. So the weight of the fluid is supported by the bottom of the container. So the fluid at the bottom is squeezed by the weight of all the fluid above it. As you go higher in the container, the fluid has less fluid above it, and is thus compressed by less weight, so the pressure goes down. At the top, the pressure is at a minimum. If fluid flows out the bottom, the pressure at the bottom decreases over time, because the depth decreases over time.\n\nNow, to answer your question: If it's true that the pressure at the bottom of a container of solid particles does not increase linearly (or at all, past some point) with depth, then it must be true that some of the weight of the particles is reacted by friction on the walls. (Otherwise, you'd be back to the fluid situation). One extreme example is if all the particles stick together as though they had been glued in place. If that were the case, the pressure at the bottom would be zero, i.e. you would not need the bottom of the container at all, you could have a hole there and nothing would come out, if the particles are sticky enough. (Hold a tube of toothpaste with the opening pointed downwards, and nothing comes out unless you squeeze it). Reality is somewhere in between: There is some stickiness between the particles and the walls, so you get friction. The particles that are not on the walls can transfer some weight to neighboring particles and then on the walls... not via stickiness, but via diagonal compression. As you probably know, in an [arch](_URL_1_), all the material is in compression, with very little local shear or tensile stresses, so very little friction is required until you get to the ends. (In a perfect [catenary](_URL_0_) arch - like the one in St Louis - it's all compression, there's zero tension or shear, except for the side-forces caused by the wind). So imagine that the particles mostly support themselves by transferring their weight to the wall along arch-shaped clusters - which rest on the walls by friction - and [only the particles near the bottom rest on the bottom rather than on an arch](_URL_3_). Does that help?\n\nEdit: Fixed \"arc\" to \"arch\"."
]
} | [] | [] | [
[],
[],
[
"https://en.wikipedia.org/wiki/Catenary",
"https://i.pinimg.com/originals/89/2a/76/892a766da71f806ca7fa7b64f67633a5.jpg",
"https://www.google.com/amp/s/www.technologyreview.com/s/418993/the-mystery-of-sand-flow-through-an-hourglass/amp/",
"https://imgur.com/a/xBybe8N"
]
] |
|
2slbju | why does the ice on this trampoline break in a rectangular shape (to the right of the jumper at 0:42) | _URL_0_ | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2slbju/eli5_why_does_the_ice_on_this_trampoline_break_in/ | {
"a_id": [
"cnqk4dg"
],
"score": [
2
],
"text": [
"it looks like the point in time where the shock wave met up with the return z motion from the jump. It is possible that differences in the thickness of the ice, slight off balance of his weight hitting the mat, or spring tension/resistance differences led to us actually getting to see it. Versus the momentum going back from mat to him and shock wave being centered on him.\n\nshorter; the mat going back up was able to toss that part of the ice up before the wave coming back from springs was able to shatter it.\n\nedit; If you need more we'll have to hope for one of the physics beards to stroll through. I know there are 2 waves moving perpendicular of one another but am not sure how to explain it better."
]
} | [] | [
"https://www.youtube.com/watch?v=gftYIkhEaAo"
] | [
[]
] |
|
4aa2s0 | how do investors pick franchises and are they preferable to starting a business on your own? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4aa2s0/eli5_how_do_investors_pick_franchises_and_are/ | {
"a_id": [
"d0ylqor",
"d0ylv10"
],
"score": [
3,
2
],
"text": [
"Investors pick franchises based on what they think will be the best fit for where they want to operate their business. Several things come into play, such as the cost of the franchise, the amount of support they get for that money, the appeal of the product in that market, and how much competition there is for that product in that market.\n\nAnd buying a franchise *is* starting your own business. But the difference is that you get a brand name that's (at least somewhat) established, a product line, training and other manuals, and often regional and national advertising.",
"They weight the advantages of going with each franchise against the cost of the franchise fee and rules the franchisor would place on them. \n\nFranchises have many advantages (frequently these include national branding, a massive marketing budget that's shared between lots of franchisees, product research, a successful model/education on how to implement the model, etc). \n\nFranchises also have rules that the owners must follow (if the owner of a mom and pop diner wants to add a dish with eggs and salmon he's free to do so, but a franchise owner of a fast food place can't just add menu items as the spirit moves them). \n\nFranchises also usually have investment requirements, net worth requirements, and franchise fees that franchise owners pay to account for the cost of the national marketing, product research, etc. There's also a risk that the franchisor will expand too rapidly (they frequently make money from new franchises opening) which can result in existing customers churning between franchises rather than a new franchise expanding to new customers. "
]
} | [] | [] | [
[],
[]
] |
||
a7tamw | how is it that johnson & johnson baby powder (talc-based) is being linked to asbestos-caused cancers, like mesothelioma? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a7tamw/eli5_how_is_it_that_johnson_johnson_baby_powder/ | {
"a_id": [
"ec5kd4h",
"ec5nthe",
"ec5o3ay"
],
"score": [
14,
8,
3
],
"text": [
"It had asbestos in it for years and they kept that information under wraps so that people wouldn't sue them or they wouldn't be held responsible. And once the information got out...",
"Talc is mined from the earth and occurs naturally next to asbestos deposits. Asbestos fibers can become mixed with talc during mining and are and hard detect without specialized testing. JnJ had testing done and several times small amounts of asbestos was detected in their talc. JnJ simply ignored these unfavorable results or chose testing less reliable methods that wouldn't pick up the asbestos. \n\nWhen the consumer uses the product a dust cloud is formed and the consumer inevitably ends up inhaling some of this dust cloud. Mesothelioma is caused by asbestos fibers getting in your lungs which can in turn be linked back to the baby powder.",
"Asbestos and talc are naturally occurring minerals which are mined. They have similar chemistries and form under similar geological conditions "
]
} | [] | [] | [
[],
[],
[]
] |
||
7g6hhl | why do we need to wear so many layers on our body when it's cold, but only one layer of pants? | Is it because of our organs or something else? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7g6hhl/eli5_why_do_we_need_to_wear_so_many_layers_on_our/ | {
"a_id": [
"dqgwotz",
"dqh08cn"
],
"score": [
12,
2
],
"text": [
"Yes, keeping your \"core\" warm is more efficient in terms of amount of clothing than insulating your extremities. Your body can transfer heat from the torso to legs and feet. However, this only works for people going between heated rooms, like from your house, to your car, to your office.\n\nFor anyone that needs to in the cold for longer than half an hour, more layers are absolutely necessary. Ask any security guard, construction worker, etc. Not sure about other branches, but in the Army we wore standard tights, beneath thicker tights, under our trousers. That's three layers for our legs and it's only for regular winter climates. It's certainly going to be more layers for colder places like Alaska or New England.",
"Branching out from what others have said; you lose heat from your chest and head. This is because your head is where your brain is and needs a specific temperature to operate at and your chest is where your heart and lungs are. The heat is circulated via the heart/blood stream which is why your toes and fingers tend to get cold - they are the extremities and non essential to your ability to be alive. \n\n"
]
} | [] | [] | [
[],
[]
] |
|
9e1azv | how are fall allergies/allergens different from spring allergies/allergens? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9e1azv/eli5_how_are_fall_allergiesallergens_different/ | {
"a_id": [
"e5lhvmb"
],
"score": [
4
],
"text": [
"Allergies are simply due to your immune system responding to something entering your body that it doesn't really need to respond to, or having a much stronger reaction than is necessary. Seasonal allergies are usually caused by some plant product (for example, pollen), so it's just your body responding to a different substance that's only around in spring or fall."
]
} | [] | [] | [
[]
] |
||
22wqea | why is it, that when trying to fall asleep people can become very anxious? | There are an increasing number of nights, tonight being no exception, where I find myself awake in bed, feeling fears I know are irrational. Tonight's fear is heart related, which I know is insane since i've recently lost a decent amount of weight and just got blood work back saying that all my levels are safe. I've posted about it on other sites, and it dosen't seem to uncommon.
Factors that may be important:
1) Im 18
2) when this started I was still applying to colleges, but I have since gotten into my target school with nearly a full ride and enough in my college fund to cover the rest without loans, so its not any stress from that. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22wqea/eli5_why_is_it_that_when_trying_to_fall_asleep/ | {
"a_id": [
"cgs3oys"
],
"score": [
2
],
"text": [
"It is probably anxiety caused by the transitional period of finding and going to a new college, anxiety and anxious thoughts can have a knock-on effect. I assume the reason it is more severe at night is because you have less immediate stimulus to distract you from your negative thought patterns.\n\nNot very scientific, I do have a booklet on anxiety at home but I am not home at the moment and can't remember the mechanism exactly enough to feel comfortable writing about it in detail. "
]
} | [] | [] | [
[]
] |
|
4kv0tl | encapsulation and getters/setters | I'm currently learning .NET and OOP programming and have always had a bit of trouble understanding just exactly what encapsulation is and how getters and setters play into it.
I understand that encapsulation "encapsulates" data to prevent other methods from accessing it, but I don't have a firm understanding of what it means. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4kv0tl/eli5_encapsulation_and_getterssetters/ | {
"a_id": [
"d3hzg8v",
"d3i30mc"
],
"score": [
6,
2
],
"text": [
"Encapsulation means that you don't have to know or care about internal workings of a class, and in fact, all internal workings are hidden from the outside, and your class only interacts with the outside world by using public methods.\n\nFor the most part, you might not care if you just make internal variable public, or if you create getters and setters for this variable. Why OOP strongly prefers getters and setters is that, you might end up changing how your class works, internally. You may be able to entirely remove an internal variable, or the value you have internally and value you want to communicate may become divorced. In both of these cases, any outside program that relied on your public variable, would now cease to function...\n\nBut if you use getters and setters, you can erase the variable but provide the same information in some other way. Anyone outside your class would never be able to notice, everything on the outside would work just the same. This means you can now rework the class as you wish, and you only need to make sure the public access methods remain, no matter how they are implemented, without any code outside of your class having to be rewritten.\n\nBasically, the goal is, if you ever change your mind about some small thing in your program, you only need to make a small change. Encapsulation means that you're now free to rework most of your class without having to worry about anything outside of your class breaking.",
"Encapsulation is a promise from the author of a class to anyone who might use it. It says, \"Access my class with the methods I give you, and I promise to make them always work the same way, even if I change other things.\"\n\nLet's say I have class BankAccount and a member called Balance.\n\nYou might be tempted to do things like account.Balance = 123.45, and that might work fine, for a while.\n\nBut then I redesign the class a little, and instead of Balance, I split it into CurrentBalance and PendingBalance, to account for transactions that haven't cleared yet. account.Balance no longer exists, and any code that relies on it will break. \n\nSo instead, I provide getters and setters for you. account.SetBalance(123.45) will always work, no matter what I do to the internals, because that is the promise I made to you. If I ever do change the SetBalance method, the onus is on me to let everyone know it is coming.\n\n"
]
} | [] | [] | [
[],
[]
] |
|
38c0xu | these long and sometimes unrelated personality quizzes/questionnaires when applying for jobs. | I'm apply for jobs while in college after leaving my first one due to too many hours and a collapsing company. I've been taking dozens of these things that range from 5-15 pages and 40-150 questions, sometimes with repeats or reworded version of the same question 3-6 times (averages off the top of my head). I just applied to a HARDWARE store for a CASHIER position and had to answer 3-4 questions (repeated and reworded) on if "I'm artist", "like to express myself through art", and "have been told to go to art school". What?!
I've seen this one company called PeopleAnswers pop up a lot. Their description is "The cloud-based system that analyzes 39 behavioral traits for job candidates and produces a fit rating, according to the company." They admit "PeopleAnswers says that nearly half of new hires turn out to be mistakes, and that nearly 90% of the problems are due to attitude. It discounts the value of skills as a predictor of success on the job." Yet they also claim "The system analyzes attitudes and behavior traits such as ambition, discipline, energy, acceptance of authority, attention to detail, flexibility, conscientiousness, and empathy."
Is this just lazy hiring for low level jobs? I hope they consider how easy it is for people to cheat these things. I'm desperately hoping my application for Software Engineer (future application) involves resumes and stuff, not what my favorite color means about me.
Can SOMEONE in or outside of HR or hiring explain this to me? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/38c0xu/eli5_these_long_and_sometimes_unrelated/ | {
"a_id": [
"cru0bnx"
],
"score": [
2
],
"text": [
"Back in the '70s, there was a huge movement in business to measure everything you could, and use that data to improve. \n\nThey developed tests to show the personality of applicants and then used them in the hiring process. On the better designed ones it didn't matter if you lied or not. They looked at the answers and compared them to \"good\" workers. The actual questions and answers were irrelevant. If all good workers checked that their favorite color is green and you did too, you're going to score higher. \n\nHR back then was much more \"scientific\" than today. Most companies no longer use tests like this, especially at higher level positions, but you'll still see them sometimes. "
]
} | [] | [] | [
[]
] |
|
1lq76d | why does fat bring so much flavor to meat; and why do garlic and onions also bring such rich flavor | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1lq76d/eli5_why_does_fat_bring_so_much_flavor_to_meat/ | {
"a_id": [
"cc1pgb6",
"cc1uy7f"
],
"score": [
9,
2
],
"text": [
"Fat is like a carrier for lipophile aromas - like the essential oils in spices and herbs. That's why fat-reduced or fat-free products need to weigh this up with more sugar, salt and (artificial) flavouring - and still are less tasty than their fatty counterparts. \nSome scientists (Stewart et al.) assume that some people can also sense fat (like sweet, sour, bitter, salty and umami) We're also probably quite prone to liking fatty foods, as the high calorie density of fat once was the best thing to save oneself from starving. \n\nGarlic and onions contain lots of strong essential oils. \nWhen heated, two chemical processes , the Maillard reaction and caramelisation, happen, which intensify flavours, too. And once they're cooked, they become soft and mushy and thus make a great base for gravy and sauces, i.e. they make them a bit thicker and give them a nice, smooth texture.",
"Fat is also where much of the stored nutrients from food go, in addition to the muscles. Since we are evolutionarily conditioned to like high energy foods for greater sustenance, we are naturally attracted to the stored energy contained in fat. The other guy explained it more scientifically, though."
]
} | [] | [] | [
[],
[]
] |
||
35ys4g | why can routers only use 2.4ghz and 5ghz if they're so congested? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/35ys4g/eli5_why_can_routers_only_use_24ghz_and_5ghz_if/ | {
"a_id": [
"cr92nm2"
],
"score": [
3
],
"text": [
"Radio spectrums are like a broad highway. Consider 2.4 and 5 as like the 2 far left lanes on a highway, but there are maybe 6 more lanes.\n\nThese 6 lanes are reserved for military communications(2 lanes), emergency responders radios(1 lane), aircraft radio communications(1 lane), and cell phone companies(2 lanes).\n\nThese other 6 lanes are vital to be restricted - what would happen if a bunch of people clogged up the aircraft lane and people flying couldn't get through to the air traffic control! That would be bad! So the FCC makes sure these important lanes stay clear as possible. Sure there are more reserved lanes - but I cut the example to just a few."
]
} | [] | [] | [
[]
] |
||
3ia0j1 | what is the point of have different words that mean the same thing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ia0j1/eli5_what_is_the_point_of_have_different_words/ | {
"a_id": [
"cuem6uy",
"cuep23r"
],
"score": [
5,
2
],
"text": [
"Very few words mean *exactly* the same thing. Most synonyms offer various shades of meaning or have different connotations even though they have the same definition.\n\nAlso, to even ask \"what is the point\" is a nonsensical question. Languages weren't made up one day by a committee of people who made rational decisions. They evolve organically, sometimes randomly. No one has any control over how it happens. So we have synonyms, sometimes unnecessary synonyms... just because. ",
"They don't always mean the same thing, there are slight variations and uses for each and they sometimes are adopted from other languages "
]
} | [] | [] | [
[],
[]
] |
||
5hfw27 | how do people raise money by doing random things like staying in a cage or running ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5hfw27/eli5_how_do_people_raise_money_by_doing_random/ | {
"a_id": [
"dazv05u"
],
"score": [
2
],
"text": [
"People sponsor them - they pay small amounts of money to encourage that person to keep going."
]
} | [] | [] | [
[]
] |
||
4zp1n1 | how am i able to wake up regularly right before my alarm almost every single day? is this a sign of a stress/coping mechanism in the brain at play or something else? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4zp1n1/eli5_how_am_i_able_to_wake_up_regularly_right/ | {
"a_id": [
"d6xlvik",
"d6xsp3d"
],
"score": [
2,
2
],
"text": [
"Your brain has a kind of internal clock that helps you wake up at the same time every day. All mammals have it; this is why cats wake their owner up around the same time every day to get fed :)\n\nBy setting your alarm for the same time every day, you got your body used to waking up at that time. Because your body roughly knows how long 24 hours are, it can roughly predict when it's supposed to wake up -- so it does. Pretty neat, huh?\n\nCheck this out for more information: _URL_0_",
"I just saw this on the front page and replied. Didnt know this wad explain like I'm five so it removed my comment , allow me to try again.\nI a strict sense, all organisms havr circadian rhythms. These are generated inside you. To be general , say by waking up you release a certain chemical. Your body gets used to releasing this \"wake up\" chemical and starting your bodily functions. Though your circadian rhythm can be modulated by external cues such as sunlight and temperature which means any noise which happens around that time like a car which drives by loudly or the heater turning off can also queue your body into that timing. This also has to do with your hearing being the first sense to reactivate in the morning."
]
} | [] | [] | [
[
"https://en.wikipedia.org/wiki/Circadian_clock"
],
[]
] |
||
1iea45 | who picked the jurors in the zimmerman court case? | The jurors were all white females who were more inclined to sympathize with Zimmerman and deliver a not-guilty verdict in my opinion. Who screens the jurors and picks which ones end up in the court room? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1iea45/eli5who_picked_the_jurors_in_the_zimmerman_court/ | {
"a_id": [
"cb3lqnk"
],
"score": [
5
],
"text": [
"I can't speak for Florida, but generally speaking...\n\nIn a court case with a jury, both the procecution and the defense have a say on who makes it onto the jury from the available jury pool. Each side can pull the \"I don't like this person\" card, sometimes a limited number of times. Also, the judge can dismiss a potential juror for whatever reason -- bias, hardship, stupidity, whatever. \"Oh yes, your Honor, I went to school with the defendant and he bullied me.\" \"You're excused. Next...\"\n\nNow, specific to the case...\n\nThe prosecution had to believe that a white jury would benefit them. Same with the defence and the all-women deal. They each had to believe this jury would benefit them because of the process of how the jury was picked. I don't know what they were thinking.\n\n\nEdit: It's late, and I'm tired."
]
} | [] | [] | [
[]
] |
|
aez0sd | refrigerate after opening | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aez0sd/eli5_refrigerate_after_opening/ | {
"a_id": [
"edu03pe",
"edu04wk",
"edu0ozo"
],
"score": [
6,
2,
2
],
"text": [
"Because they've been treated to remove bacteria, which can grow by feeding on the material.\n\nOnce you open it, you've exposed it to bacteria again.\n\nYou can't get the cat out of the bag again.. wait is that how that goes?",
"They contain no microorganisms. Once you open the package, they do and must be refrigerated to retard growth.",
"Before they opened those products are free of bacteria due to the packaging processes, usually canning. The process itself kills bacteria and fungus and the packaging prevents new stuff from getting in.\n\nOnce the package is opened, fungus and bacteria in the air will enter, and the clock is ticking. "
]
} | [] | [] | [
[],
[],
[]
] |
||
213e1g | when you're on a trampoline with other people, how does "stealing someone's bounce" work? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/213e1g/eli5_when_youre_on_a_trampoline_with_other_people/ | {
"a_id": [
"cg9akd1",
"cg9fk9y"
],
"score": [
4,
4
],
"text": [
"When you land on the trampoline you are coming down with a downward force. This force will make the trampoline stretch.\nThe trampoline then wants to return to a less stretched state and push you up at which point you jump again to jump higher or keep jumping.\nThe trampoline can only stretch up to a certain point overall. \nSo when your friend lands, while you are at your lowest point and the trampoline is at it's most stretched, the trampoline has to push you up faster and harder so it can stretch where your friend is landing. \nThis is also why your friend will lose his/her bounce because he/she is landing on an already (partly) stretched trampoline.\n\nSo you are pushed up by the trampoline's force but also part of your friend's downward force. Which is why you go higher.",
"Bouncing on a trampoline works just like bouncing on any surface, but because the trampoline slows you down gracefully rather than suddenly, it's much more enjoyable.\n\nSo to understand a double bounce, we have to look at what happens with a single bounce. Whenever anything bounces, you end up with a net vector change in the momentum. When a person hits the trampoline, the surface exerts a force to slow and stop them, in the opposite direction to the person's movement.\n\nThis force is equal to TWICE the force actually needed to slow the person to a stop, which means that once they stop they are accelerated in the opposite direction with an equal amount of speed as they originally bounced. The reason's for that are complicated, but that's what happens, that that's what we need to know.\n\nSo when someone \"steals your bounce\" it's usually because they hit just after you've built up the force to stop you, but that force can't be fully released because now the trampoline stretches further to accommodate your friend. Meanwhile, you're now stopped on the trampoline, essentially standing on it. The trampoline can't tell that that was YOU who deformed it first, it just knows that another body is still deforming it. Energy wise, all of the momentum is transferred to the second body, while you're relegated to simply returning to the level of the trampoline surface, as if you had always been standing on it, not bouncing."
]
} | [] | [] | [
[],
[]
] |
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