q_id
stringlengths 5
6
| title
stringlengths 3
296
| selftext
stringlengths 0
34k
| document
stringclasses 1
value | subreddit
stringclasses 1
value | url
stringlengths 4
110
| answers
dict | title_urls
sequence | selftext_urls
sequence | answers_urls
sequence |
|---|---|---|---|---|---|---|---|---|---|
o4jjy | why israel seems a lot more developed and rich than many other middle eastern countries | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/o4jjy/eli5_why_israel_seems_a_lot_more_developed_and/ | {
"a_id": [
"c3ebeqy"
],
"score": [
7
],
"text": [
"To begin with, Israel isn't much richer than most middle eastern countries, since (a lot of them) have oil. \nIsrael *is* more developed than most of those countries, and has a higher GDP(The amount the country produces in American $) per person.\n\nThe immediate cause of this is that the economies of the rich middle eastern countries is based on their natural resources (oil mostly), which Israel's economy is based on their human capital (an educated and technically competent workforce). \nGoing one step back, countries that, at their foundation, do have a lot of wealth in natural resources tend not to invest that in human capital, this is called the [Resource Curse](_URL_0_) and there are a lot of possible explanations for it, but no certain one, nor any one that fits every case (this happens a lot in Africa, as well). \nIsrael, on the other hand, who only recently discovered natural resources (large natural gas deposits off the northern part of the coast), could not grow it's economy with any resources other than human capital. \n\nThat is true for a lot of countries, however in Israel's history there were a series of both good decisions/policies on the part of it's government, and a flow of cash donations and resources from outside the country that enabled it to grow it's technology and defense sectors large enough to sustain a modern economy. \n\nThe first part, the good policies, include most glaringly the large investment the Israeli army makes into maintaining a technological edge over it's enemies - Israel's army is a conscription army (every non arab citizen has to server for 3 years in the army) and it enabled people with a natural aptitude (and the an acceptable socioeconomic background) for technology to serve in the Israeli military intelligence, or in other technical positions in the army, which sent people who the army selected for a technological or scientific aptitude into the high tech industry, already with experience. \nIn addition, a lot of the largest Israeli high tech companies were founded by people who gained some knowledge or another in the army, and then found a way to sell that knowledge in the civilian market ([NICE](_URL_2_), [Elbit](_URL_1_), [Rafael](_URL_3_) and more).\n\nMany of Israel's most successful institutions: banks, health insurance agencies, agricultural and industrial companies were founded as cooperatives, or within unions, with no profit motive and with the purpose of serving their members (rather than stockholders or executives) and developing the economy (Egged, Tnuva and Clalit are good examples of this).\n\nFor the second part, the universities in Israel were built early into it's history, with generous donations from north america and staffed with European academics that fled to Israel due to antisemitism in their home countries, many other institutions were also built with American and Canadian money and operated by European professionals."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Resource_curse",
"http://en.wikipedia.org/wiki/Elbit_Systems",
"http://en.wikipedia.org/wiki/NICE_Systems",
"http://en.wikipedia.org/wiki/Rafael_Advanced_Defense_Systems"
]
] |
||
4ocslc | why does microsoft word sometimes reformat half my document just because i hit enter or delete a space? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ocslc/eli5_why_does_microsoft_word_sometimes_reformat/ | {
"a_id": [
"d4bhdge",
"d4bhhfl"
],
"score": [
2,
4
],
"text": [
"This can be anything. You give it some guidelines in the formatting you do, and Word tries to format it as good as it can within the rules you give it. \n\nFor example when you put an enter or space that makes the last word of you paragraph not fit on the page, it would look silly to have only that word on the next page. So it will pull some extra lines with it. It's all meant to help you, and if it's not how you want you'll have to specify yourself (you can). \n\nGenerally postpone the formatting as long as you can, or just use LaTeX. ",
"The boring answer is that you've deleted a formatting character such as a section break, or you've caused an element in your document to get bumped to somewhere where it triggers a bunch of Word's other arrangement/formatting rules, potentially causing a cascade of fuckery.\n\nSome of the time it lets you do things that you shouldn't be able to (because of the problems it might cause later if you change something and it carries on trying to follow its own logic). It's flawed software basically, though that isn't to say that users don't create their own problems with it too."
]
} | [] | [] | [
[],
[]
] |
|
67f4la | why english distinguish between fingers and toes unlike other languages and what about thumbs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/67f4la/eli5_why_english_distinguish_between_fingers_and/ | {
"a_id": [
"dgpxqlg",
"dgqjzp9"
],
"score": [
4,
2
],
"text": [
"English has been a language that loves to get unique and specific names for everything, especially Old English. Finger, toe and thumb are all very old words. The main reason they have their own names is really because the language has placed an emphasis on finding a new word for something rather than mixing or combining words. You could call a thumb the big finger, but that is slower than the word 'thumb'",
"English is not the only language that distinguishes between them, although not all languages do.\n\nThere's no law saying that languages have to match each other exactly. Different cultures have different ways of classifying things. Russians just use the word \"palets\" to refer to an appendage on the end of a limb, and if necessary specify \"palets na noge\" (\"finger on the foot\") for a toe. Germans and English-speakers have a word used for appendages used to manipulate, appendages that make gripping possible and appendages for walking on. The French can use their word for \"finger\" to refer to toe if the context makes it clear, but have another, different word they can use instead."
]
} | [] | [] | [
[],
[]
] |
||
4d8w9l | air resistance and newton's second law | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4d8w9l/eli5_air_resistance_and_newtons_second_law/ | {
"a_id": [
"d1orv0k"
],
"score": [
2
],
"text": [
"What's your question? \n\nNewton's 2nd Law states that the acceleration of an object is dependent on the net forces acting on the object & the mass of the object. Air resistance is part of those net force."
]
} | [] | [] | [
[]
] |
||
es6fds | extra chromosomes | Why is it that having more chromosomes makes you have physical and mental problems? I get that having less than the correct amount could mean missing info and stuff but why does extra cause problems? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/es6fds/eli5_extra_chromosomes/ | {
"a_id": [
"ff85aon",
"ff86glu",
"ff9ite6"
],
"score": [
6,
3,
3
],
"text": [
"Extra chromosomes would cause problems when our DNA and cells replicate. It would cause misalignments of DNA during cell separation, causing one cell to get extra copies and others to acquire none, or even cause DNA breakage events. These may render DNA unusable and may break crucial sequences that are required for normal functioning. Extra chromosomes that actually do work may cause protein imbalances which also affect basic cellular and/or organ functioning.",
"DNA, which is arranged in chromosomes is the blueprint for building a person. It's like a recipe. Imagine you're baking a cake and it tells you to add 3 eggs. Now let's pretend there's a misprint in the cookbook and it says to add 6 eggs. Your cake is going to come out messed up if it even comes out at all, right?",
"To add to all the great analogies, in most cases having an extra chromosome or missing one is not compatible with life and would lead to a miscarriage very early on in the pregnancy. In fact, most women who miscarry never knew they were pregnant. \n\nOnly a very select number of these mistakes can produce a viable fetus. The most common being trisomy 21 (down's syndrome)"
]
} | [] | [] | [
[],
[],
[]
] |
|
6gr0tf | why do tv shows use identical twins to portray one character? | For example, Michelle Tanner in Full House was portrayed by Mary Kate and Ashley Olson or Jamie from Malcom in the Middle was portrayed by James and Lukas Rodriguez. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6gr0tf/eli5_why_do_tv_shows_use_identical_twins_to/ | {
"a_id": [
"diseft5",
"diseg1y"
],
"score": [
7,
10
],
"text": [
"The common thread in your examples is that the characters are **children**. Children are not great actors. They are hard to direct on a set. Depending on age, it can even be hard to get them just to do or say what the script requires. Additionally, children have short attention spans and get tired quickly.\n\nWhen you have a pair of twins, you get more opportunities to do repeated takes until you get it right.",
"There's a lot of laws around child labor. It's largely banned in many industries but exceptions are made where it's unavoidable, like child actors. Even there, there's a lot of requirements & regulations about working hours & conditions. There's no good way to deal with limited working hours & make a child a major character in a show without having two of them."
]
} | [] | [] | [
[],
[]
] |
|
34wiis | where does the bulk of our knowledge of ancient rome come from? | I've heard that most of the historical records were lost during the Great Fire of Rome in 69AD but I haven't really been able to turn up much reliable info on the net. I would love to hear from an expert. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/34wiis/eli5where_does_the_bulk_of_our_knowledge_of/ | {
"a_id": [
"cqyrmpd",
"cqz4391"
],
"score": [
4,
2
],
"text": [
" > I've heard that most of the historical records were lost during the Great Fire of Rome in 69AD\n\nI think you're confusing this with the loss of historical records during the [Gaulish sack of the city in the early 300s BC.](_URL_0_) Sources for the period before that disaster are, in fact, very scarce. Even secondary sources, like Polybius and Livy, don't seem to have much clear information about events in Rome before the sack.",
"I'll try to provide an overview, seeing as nobody else has.\n\n* Literature - a large body of literature (in Latin and Greek) from the Roman period survives; the fire (actually 64 AD) didn't really affect that to my knowledge, as there was more than one copy of each work. As someone else mentions, there is more of an issue with the Gallic sack c. 390 BC, before which our knowledge is very limited. But from the \"historical\" period, especially from the first century BC onwards, we have histories, geographies, encyclopedias, speeches, philosophies, poetry, grammatical works...all sorts really. We don't tend to have \"originals\" of these works - they survive through copies made by monks in the Middle Ages. The discipline of ancient history is mainly concerned with the study of ancient texts, as opposed to...\n\n\n* Archaeology - the study of material culture. The Romans left a huge amount of material behind to be studied, from the Colosseum and Hadrian's Wall to the fragments of pottery being excavated all the time. Archaeology can often tell us more about everyday life for ordinary people than literary texts, which tended to be written by rich men, and can confirm (or challenge) the literary sources mentioned above. Archaeology can also include art and architecture under its umbrella, although art history is often studied as a separate discipline.\n\n\n* Epigraphy - the study of inscriptions. The Romans produced a staggering number of inscriptions, of which hundreds of thousands survive, with more being discovered each year. Whilst they tend to be shorter than literary sources, inscriptions have the advantage of surviving as \"originals\" rather than medieval copies. All sorts of things were inscribed: laws, gravestones, religious dedications, etc. Inscriptions can vary greatly in their scope - from those badly damaged by the effects of time, so that only a few letters are now legible, to something like the [*Res Gestae Divi Augusti*](_URL_0_), the bilingual autobiography of the emperor Augustus which was inscribed throughout the Roman world.\n\n\n* Numismatics - technically a branch of archaeology, this is the study of coins, one of the most commonly excavated types of item. Coins are useful for economic history: the quantity of precious metal in them can reflect the state of the economy at their time of production, and their distribution can indicate the extent of trade routes.\n\n\n* Papyrology - In Egypt, the dry climate means that many documents written on papyri have survived.\n\n\nThose are the main types of sources available to ancient historians, archaeologists, and classicists. I'd be happy to answer any follow-up questions."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Battle_of_the_Allia"
],
[
"http://classics.mit.edu/Augustus/deeds.html"
]
] |
|
2efxqj | why is it that when we first wake up, our eyes don't work very well? i don't mean the re-adaptation from darkness into the lit environment, i mean that our sight is really bad even moments after adapting to the light. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2efxqj/eli5why_is_it_that_when_we_first_wake_up_our_eyes/ | {
"a_id": [
"cjz31bk"
],
"score": [
2
],
"text": [
"Film builds up on your eyeballs overnight. It has to be rinsed off by your tear ducts. "
]
} | [] | [] | [
[]
] |
||
4bcuav | ; why is the qwerty keyboard configuration slower than the alphabetical form? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4bcuav/eli5_why_is_the_qwerty_keyboard_configuration/ | {
"a_id": [
"d17yfky",
"d17yfzv",
"d17yglw",
"d17ypkk"
],
"score": [
10,
5,
2,
2
],
"text": [
"It isn't that they specifically typed faster. It is that certain letters that are used frequently in combination were typed too fast...causing them to lock together in typewriters. They needed to move the letters that go together often to places on the keyboard that won't cross and get stuck.\n\nWe type just as fast with qwerty. It is just that certain letters rarely get typed in succession that would get locked together.\n\n",
"QWERTY was introduced to put letters that are used most not too close together so the parts that strike the tape in the machine wont intersect while person is typing fast. ",
"Manual typewriters required some finger strength to press the keys. QWERTY was invented so that the keys you press the most are near your strongest fingers. They could have done a better job of this, but they didn't because of the reason you mention. Another configuration called DVORAK is superior, but it hasn't caught on.",
"QWERTY has more to do with letters next to each other being pressed at the same time, and less with speed.\n\nWith a typewriter, if you press 2 keys next to each other (same row) at nearly the same time, they can collide, bind, and get stuck or even break. QWERTY was designed because letters commonly used in sequence are placed on separate lines.\n\nABCDEF configuration is not optimized for typing. That's the reason \"DVORAK\" was developed. It places keys in a way where the most used ones are most easily accessible. This requires less movement, and thus, faster typing.\n\nKeyboards don't bind, and the need for QWERTY no longer exists, but it's stuck around just because typists learned it and never went back. People are used to it. It's not the best, it's just the best known."
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
2jzy1q | why don't the jehovah's witnesses churches have any windows? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jzy1q/eli5why_dont_the_jehovahs_witnesses_churches_have/ | {
"a_id": [
"clglcob",
"clgmtk2",
"clgru0s"
],
"score": [
2,
3,
2
],
"text": [
"They are called \"Kingdom halls\" not churches. Also, the ones I have been too have windows... ",
"As far as I know, historically vandalism of JW Kingdom Halls has been decreasing over the years. Starting at the end of WWII it was quite bad, and gradually has reduced to where it is today.\n\nThe older the structure, the greater the probability that it has no windows to reduce the likelihood of vandals breaking in and causing more significant damage. I suspect that the standardized blueprints for new construction were not adapted to include windows until the last couple decades. Remodels likely still exclude windows due to the cost of adding windows where they have not been.\n\nWindows aren't needed though. Kingdom Halls have plenty of interior lighting. Also, many churches have stained glass windows with depictions of some saint or VIP, but JWs don't agree with the worship of idols or images and therefore do not use stained glass windows in their architecture. It certainly is less expensive to build and maintain that way! Much easier for a donation-based organization.",
"many of them do have windows. just do a google image search for 'kingdom hall'\n\n\nthey are also built quick, usually over the period of one or two weeks, so not having windows saves time and construction expense. also it's one less thing to have to repair if someone breaks them.\n\nAll their meetings are open to the public, so it's not like there is secret stuff going on inside that they don't want people to see"
]
} | [] | [] | [
[],
[],
[]
] |
||
44kcr4 | if water has no nutrional information how does it support life to function? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/44kcr4/eli5_if_water_has_no_nutrional_information_how/ | {
"a_id": [
"czqtlb9",
"czqto4c",
"czqtpe3",
"czqtw7b",
"czqu19v"
],
"score": [
5,
6,
2,
3,
2
],
"text": [
"You are 60% water, and you use it up everyday to maintain bodily functions, like breathing and other important shit. So technically, you have to replace it by consuming more water.",
"Water is an excellent solvent. Our body chemistry depends on thousands and thousands of different molecules being able to interact freely in a liquid; and water is both common and effective. As humans, we have evolved with the assumption that a certain amount of fresh water would be available to take in each day; so we use up that amount of water in other ways (exhaling water vapor/droplets, sweating, urination). Animals which live in environments with much less available water have evolved to use water much more carefully; some small animals excrete so little water that they get enough from the seeds they eat and never have to drink liquid.",
"Water is polar and allows a lot of reactions to occur within it. Also a lot of carbs and sugars are basically made up of water I believe the basic formula of it is CH2O so water in one way or another makes up a lot of important molecules that support life and the reactions needed to provide life. ",
"Your cells are mostly water, encased by a membrane. Between your cells is water and there's always a balancing act that takes place to keep these levels relatively constant. All of the processes that take place inside a cell, including the breakdown of energy substrates (sugars, proteins, fats), movement of ions, nutrients, wastes, etc... take place within the cell's water, and between the cell and the water outside the cell. Without water then, the processes that keep cells alive would cease.\n\nIt's not that it provides nutritional value, water is what allows cells to process nutrition and perform their functions. ",
"Blood is mostly water. It carries oxygen. Muscles are 75% water. Besides supporting the skeletal system, smooth muscle propels food through our system. It lubricates joints. Allows our kidneys to filter blood. Flushes out waste. It's released even when exhaling, but is needed to maintain blood pressure and body temperature. Other drinks (as well as foods) will do the same job because, they too, are mostly water. The exceptions lie in salt water (lost at sea mistake!) and alcohol (lost at sea mistake?). "
]
} | [] | [] | [
[],
[],
[],
[],
[]
] |
||
9j7b43 | salt lamps?? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9j7b43/eli5_salt_lamps/ | {
"a_id": [
"e6p7slx"
],
"score": [
6
],
"text": [
"They provide some light, and they look sort of cool.\n\nThere is absolutely no evidence they have any effect on your health."
]
} | [] | [] | [
[]
] |
||
65fwao | why did slavery in the 1800s only exist in the agricultural economies of the south and not the industrial economies of the north in the us? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65fwao/eli5_why_did_slavery_in_the_1800s_only_exist_in/ | {
"a_id": [
"dg9wwsx",
"dg9xig8"
],
"score": [
10,
4
],
"text": [
"Because oddly enough holding slaves was pretty expensive and in the north there were hordes of immigrants that would work themselves almost to death for almost no money at all. Also, tradition. ",
"Part of the reason was the explosion of industrialization in the Northeast. Large factories don't need slave labor to prosper, whereas massive plantations do. It's purely economics. \n\nThe wealth of the south was entirely dependent on agriculture which needed cheap labor, not to mention people who wouldn't need their own houses, which is a major waste of valuable farming land. \n\nMeanwhile, the north developed industry that didn't depend on slaves to survive. A large part of this disparity is geography. Not only is farmland in the north not as productive as the south (shorter seasons), but industry of the time was almost completely powered by water. Narrow, fast-running rivers were ideal for factories, and the Northeast has those in spades."
]
} | [] | [] | [
[],
[]
] |
||
76wm3t | how does advertisements actually profit? i find it hard to believe that they actually cover the cost that it took to run. | For example, a holiday inn running a commercial. Surely that commercial is not convincing anyone to go stay at a holiday inn. Or a ford commercial, how many people out there are actually convinced to buy a ford truck by watching a commercial? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/76wm3t/eli5_how_does_advertisements_actually_profit_i/ | {
"a_id": [
"doh9sbd",
"doh9wy5",
"doh9zar",
"dohadq8",
"dohbvlr",
"dohl6id"
],
"score": [
2,
2,
2,
5,
2,
2
],
"text": [
"Advertising has really helped some products. This has been shown time over time. Therefore advertising agencies exist. They use these examples to prove their worth. Company executives believe them. They believe them implicitly. \n\nThey also believe in the secondary benefits of an ad or an ad campaign. After a while the company executives believe in getting their name out, in being present. They just want you to know that they are in the world so you will select their company when you have a choice.\n\nI haven't owned a Ford ever. But I considered one when making my selection.",
"So while there are obviously going to be situations where the amount of money gained from an advertising campaign is less than what you spent on it, overall you make more money putting more money towards advertising campaigns by bringing in more sales. \n > Surely that commercial is not convincing anyone to go stay at a holiday inn. Or a ford commercial, how many people out there are actually convinced to buy a ford truck by watching a commercial?\n\nYou're problem seems to come from assuming that people aren't affected by advertising or able to have their habits swayed whether consciously or subconsciously which is obviously not the case. There has probably been more money and research put into advertising and it's effectiveness than almost anything and they are constantly researching how to make it more effective. \n\nAs far as your example, while the commercial probably won't make you decide to run out and take a vacation and stay at a Holiday Inn, but it could easily put the brand in your head so you'll choose it next time you do or they may be running a special that works perfectly for your next trip or one of your employees. \n\nAs far as Ford, you are forgetting that there is always a sizable chunk of the population that is in the market for a new car and seeing the design of the new Ford truck or seeing what financing deals are available may be enough to push you to go with the Ford rather than the Chevy. \n\nFor stuff that is so ubiquitous that it seems pointless to have advertising anymore such as Coca Cola or McDonalds they are normally literally just trying to remind you of the product, keep it on your mind and maybe push you to crave it or cause you to associate it with a certain thing that will push you to consume more, such as a commercial that does nothing but remind you how great Coca Cola goes with a burger. ",
"The purpose of an ad isn't to convince you to buy what they're selling. It's to let you know that they're selling it. ",
"Yeah they do. There are metrics they run. Some ads work and some don't. That is where an agency comes in. They do all the market research on what should bring new customers in your door. So lets take Holiday Inn for example. Not every ad is big budget. Some are small low cost and some are high dollar budget. Each one serves it purpose. Large expensive campaigns are about brand awareness. So when you think hotel the first name to pop into your head is Holiday Inn. These will be run at regular intervals during high rated prime time shows. They will be shocking usually with humor and will probably avoid the color red and have a lot of bright colors that complement blue but will many be greens and yellow tones. If watching TV in a dark room the commercials usually light up the room with its tones. Each camera angle change creates a dynamic tone change to mimic the effect of a police light. Attention, attention. The blue complimentary tones in such a manner are exciting but somewhat calming. Trusting tones. If its a lawyer ad for a accident lawyer. They will often do the opposite. Complimentary tones to red. Showing power, and dominance. So Holiday Inn is planting a seed in your brain that they are exciting, trustworthy, flashy but safe. Than they have the upkeep ads. Shorter less flashy, hardly any humor. They might be just their logo on billboards, 30 secs calm ads at less watched times on tv where they pay a channel X amount of dollars to show X amount of times in a specific date range of their choosing. That isn't about brand recognition but to just remind you over and over. Holiday Inn express. Holiday Inn Express. The hardest part of a business is getting new customers. New customers are the life blood of any business. And they are worth a lot. You are looking at each potential customer as being only worth their visit. But its considered so much more than that. Im going to give a hypothetical situation of their value. Lets say a company got a large group of people and divided them up in groups. They took the largest group lets just say its 20 total people as the example for ease in that group and tailored an ad that is specific to them. They hit all the marks in the commercial based on predetermined likes and needs of that group. The group wanted a value, but it to look like a nice hotel. The group also travels for work, and breakfast included is a perk. They are ages 35-50 and the humor they like is somewhat goofy not edgy. All 20 watch the commercials and over 90% of them are impressed by Holiday Inn Express's promises. \n2 had previously bad experiences with the hotel, but are now reconsidering staying at another sometime to give them a chance. One in the group travels with a team in a company for promotions and is in charge of booking all the stays for everyone. Only one person doesn't think they would choose holiday inn express in the future. Most plan to use in the future if traveling. More than 10 plan to use it with in a year. Most importantly most will think of it now when the topic of getting a hotel room. Also people use company names as examples when suggesting things. Someones mother in law has to head in for a funeral. People part of the ad focus will now say stuff along the lines. Hey are you going to stay in town that weekend? Do you need to stay at the house or are you going to need a reservation at a holiday inn or something. The commercial plants that word to be less proper noun and just be a common noun for something. Like some people refer to soda as Coke even when it is not. Holiday Inn wants their name to be to the word hotel as Coke is to the word soda. Back at those 20 people though. Even only 20 people the possibility of those people being a driving force is endless. Not only does holiday Inn possibly gain their business the first time, but they have a chance for repeat business with those and all the referrals that come after that. \n\nNow multiply that by the number of people who watch any given prime time show live on tv, its in the millions. That commercial was designed for the largest group of potentially customers they could faction a commercial for. Of that group of hundreds of thousands of potential first time customers. They have to convince those thousands of customers to come in or come back so they can continue to form a larger and larger loyal customer base. \n\nAnd since their loyal customers die off eventually they have to continue this game until they are no longer profitable and viable as a company.\n\n\nIf an ad doesn't bring new customers in the door, the ad company is replaced.",
"Actually, advertising is all about hitting the right person at the right time. Obviously, ads fall on deaf ears when it comes to most of the people, but, as /u/oxencotten mentioned, it primes you as far as brand awareness is concerned and, the next time you actually need whatever it is they offer, you may look them up.\n\nAs for anecdotal evidence, while I usually am not swayed by commercials, a particular commercial drove me to a particular brand of trash bags, after they highlighted the issue of ruptured bags and made me realise I don't have to put up with that crap anymore, as a company was aware of the issue.",
"What I've read, and this may not be true, is that much of advertising is not able explicitly convincing you to choose one product over another(Holiday Inn vs Motel 6 for instance) but rather it very subtly influences you to choose one because we, as humans, generally choose the product we are most familiar with, given the utility it provides is roughly comparable with its competitors. If Holiday Inn blitzes you with ads, its possible that your increased familiarity with it compared to its competitors can almost imperceptibly influence you to choose it, if the service it provides is about equal in quality and price to competitors. "
]
} | [] | [] | [
[],
[],
[],
[],
[],
[]
] |
|
3r0smg | how and why do some substances stay in our body 'forever', like heavy metals? | I realise organic molecules eventually break down, but this isn't the case for heavy metals. Say we 'store' Mercury as an example, where does it go? Does it concentrate in one of our organs or something?
Why does the heavy metal not leave our bodies as we grow new cells and get rid of old ones? I remember reasons every single cell (minus some nerves etc) will be replaced within 7 years | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3r0smg/eli5_how_and_why_do_some_substances_stay_in_our/ | {
"a_id": [
"cwk0asd"
],
"score": [
5
],
"text": [
"Every metal has what is called a biological half life. IF you up take it though ingestion, absorption or inhalation, it takes some amount of time to move through your system. \n\nThe concept is used quite a bit for body burden determinations when exposed to radioactive materials. The body does not differentiate between radioactive and not since they are chemically the same. \n\nSome things such as strontium, radium, plutonium, and samarium are \"bone seekers\". They are chemically similar to calcium and will be up taken by the body and end up in bone where calcium normally would be. It takes them a very LOOOOOONG time to leave the body once uptaken and deposited in bone. Plutonium has a biological half life of about 100 years. So if you uptake X amount of plutonium, in 100 years you would have 1/2 of X amount still in the body.\n\nNow Potassium-41 which is a radioactive metal and will be processed through the body fairly quickly since potassium processes quickly. Somewhere around 16-20 days. \n\nSo to answer your question: it depends on the specific metal. It is chemically similar to other metals used in the body, it will get processed like those. Depending on what it is similar to will determine how long it is in the body. Also what form it is in will determine quite a bit about how much is initially uptaken and how long it is retained. \n\n"
]
} | [] | [] | [
[]
] |
|
cc4793 | how does _url_0_ work? i find it is very accurate; the thunder projection is almost always spot on, but i don't get how they can detect lightning. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cc4793/eli5_how_does_lightningmapsorg_work_i_find_it_is/ | {
"a_id": [
"etkd571",
"etkfvvu",
"etktjls"
],
"score": [
7,
5,
2
],
"text": [
"There are lots of antennas that are registered with _URL_0_\n\nThose antennas detect lightning by means of picking up their electromagnetic waves they create when lightning occurs. If you get an AM radio, you can do the same by tuning it to the lowest frequency and listen for the static that happens when lightning strikes. Each of these antennas have their location known by GPS, so each antenna that detects a strike reports the strike and the system knows the gos location of each antenna and triangulates the strike and displays it on the map.",
"When lightening strikes, it makes radio waves, similarly to how objects make a \"whack\" noise when they collide. This radio \"whack\" is very obvious to any antennas nearby, and these antennas can compare the time at which they heard strikes in order to figure out where exactly the strikes are.",
"Thank you for asking this question. I had no idea this website existed. I have added it to my home screen. Thank you."
]
} | [
"lightningmaps.org"
] | [] | [
[
"lightningmaps.org"
],
[],
[]
] |
||
1lohjn | why did the term milliard (now billion) seemingly vanish in the english language while it still exists in many other lanuages? | Or why did the affix '-ard' vanish in english counting? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1lohjn/eli5_why_did_the_term_milliard_now_billion/ | {
"a_id": [
"cc18iu7"
],
"score": [
2
],
"text": [
"I was going to take a wild guess and say that in English, million and milliard are too close to each other phonetically, but that doesn't seem to be the right explanation.\n\n\nIt looks like in Europe billion originally meant a million million, until the French had the bright idea to change that to 1000 million, so 'milliard(e)' became superfluous. The US adopted this and stuck with it while France went back to the older system. [Source](_URL_0_) "
]
} | [] | [] | [
[
"http://www.etymonline.com/index.php?term=billion"
]
] |
|
3jn2gk | what is super symmetry and how does breaking it create new universes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3jn2gk/eli5_what_is_super_symmetry_and_how_does_breaking/ | {
"a_id": [
"cuqo8ee"
],
"score": [
5
],
"text": [
"Supersymmetry is the idea that every particle has a heavier \"superpartner.\" Each particle come in two flavors, the lighter regular particle (like an electron) and the very heavy big brother (let's call it a selectron).\n\nThe electron is a fermion: it can't share states with other electrons. The selectron is a boson: it can share states with other selectrons. For particles whose regular version is a boson, like photons, their superpartner is a fermion.\n\nThe idea of the symmetry is that if you're out looking for particles, you will find an equal number of electrons and selectrons. They're symmetric, the universe is equally likely to produce either one, so you get a 50/50 split.\n\nWe've never observed a selectron in nature, though, so if this symmetry exists, it's broken. At very high energies, the symmetry may be true, but at low energy it's broken and we only see electrons.\n\nThere are a few reasons why we think that supersymmetry is true, despite never having seen a superpartner. The main one is that the Higgs boson doesn't have enough mass.\n\nThe interaction between the Higgs boson and the other types of particles should affect what its mass is, like how the interaction between an electron and the Higgs field gives the electron mass. The biggest mass correction to the Higgs is from the top quark, whose interaction should make the Higgs mass very large.\n\nIt's not very large, though, so something's wrong. What could be an explanation is that if there's another particle which interacts with the Higgs in the exact opposite way that the top quark does, the corrections neatly cancel out, and the Higgs has the correct mass. A stop squark (superpartner of the top quark) fits the requirements for such a particle.\n\nI am not aware of how supersymmetric symmetry breaking leads to new universes. They seem like unrelated ideas."
]
} | [] | [] | [
[]
] |
||
2r2yn4 | why don't oreos absorb almond milk as fast as cow's milk? | So this is the first time I've consumed Oreos in a long while. I was dipping and dapping them in some almond milk and noticed they weren't acting the same. Thoughts, knowledge, ideas? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2r2yn4/eli5_why_dont_oreos_absorb_almond_milk_as_fast_as/ | {
"a_id": [
"cnbzl1h"
],
"score": [
9
],
"text": [
"I don't want to be the bearer of bad news, but oreos have changed their recipe. They're using cheaper fats. They do not act the same in cow's milk, either."
]
} | [] | [] | [
[]
] |
|
70o5cf | why can't our mind just shut up? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/70o5cf/eli5_why_cant_our_mind_just_shut_up/ | {
"a_id": [
"dn4lgrf"
],
"score": [
3
],
"text": [
"Our mind's \"job\" is to keep us alive, so it uses its spare capacity to think about things that might harm us (and what to do about it), or opportunities to improve our situation.\n\nYou can learn to control it somewhat. See /r/mindfulness or (more advanced) /r/meditation."
]
} | [] | [] | [
[]
] |
||
9w3vm8 | when a whale dives to depths of thousands of feet, why does the extreme pressure not force seawater through its anus into its colon? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9w3vm8/eli5_when_a_whale_dives_to_depths_of_thousands_of/ | {
"a_id": [
"e9ham1l",
"e9hd8ic"
],
"score": [
28,
5
],
"text": [
"By having colon muscles strong enough to prevent that.\n\nAlso they have eyes, mouths, blowholes... why would you single out their anus?",
"Cause mr whale sqeezes his bum hole shut, just like you do at the pool when you do a big jump.. bodies can do amazing things even without us having to pay attention ! "
]
} | [] | [] | [
[],
[]
] |
||
5exk0a | why are neo-nazis even a thing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5exk0a/eli5_why_are_neonazis_even_a_thing/ | {
"a_id": [
"dafw01w",
"dafwdi7"
],
"score": [
4,
2
],
"text": [
"The logic is fear. Neo-nazis see themselves as surrounded by other people that have things they don't. So, they subscribe to a philosophy that allows them to tear those people down and negate their achievements. Thus, they are able to feel better about themselves because their entire belief system places them at the top of the food chain.",
"Racial superiority is a concept that never died after WW2, it has always existed. The national socialist party had put so much research and effort into the study of racial superiority and the concepts of unter Menschen and codified it into culture that it made it easy for other groups to adopt. \n\n"
]
} | [] | [] | [
[],
[]
] |
||
2qa6oy | how come computer hardware is getting better and better, but at the same power cost? | It just seems odd and amazing (yeah, both at the *same* time) how it just got better without any losses. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2qa6oy/eli5how_come_computer_hardware_is_getting_better/ | {
"a_id": [
"cn48obq"
],
"score": [
5
],
"text": [
"It's not always about the NUMBER of circuits they can fit onto a board, but also about the efficiency of those circuits, and building a physical electrical layout that will provide better computational processes.\n\nThink about the switch from HDD to SSDs - the increase in complexity and efficiency made a huge leap, but not because of an enhancement on the old, but a complete paradigm shift to a new architecture that had different power requirements than its predecessors.\n\nThat being said, in general, more complex hardware components have increased power requirements, though it's less than a linear progression for the reason above.\n\nBattery technology has also improved, allowing personal electronic devices to stay the same size while actually storing more power required to operate more complex systems."
]
} | [] | [] | [
[]
] |
|
1zzypu | if we could farm lightning and did so, would there be any negative consequences? | Like, if lightning doesn't hit the ground but instead a big battery that powers the world would this cause the earth's electromagnetic activity to whack out. At a 5 right now | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1zzypu/eli5_if_we_could_farm_lightning_and_did_so_would/ | {
"a_id": [
"cfyi231"
],
"score": [
3
],
"text": [
"I dont think so... they're more or less seperate; ground and live are relatively isolated systems.\n\nSource: none, I'm basing this on nothing"
]
} | [] | [] | [
[]
] |
|
3h4dcm | why aren't time zone borders straight and equidistant from each other like longitude/latitude lines? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3h4dcm/eli5_why_arent_time_zone_borders_straight_and/ | {
"a_id": [
"cu43ssi",
"cu43v5m",
"cu43x10",
"cu4dy79",
"cu4e783",
"cu4gban",
"cu4geih"
],
"score": [
24,
91,
56,
3,
4,
6,
3
],
"text": [
"Because all countries can choose what time zone they observe.\n\nThat's why all of China observes the same time zone officially.",
"Time zone borders are roughly drawn 15 degrees apart, but move do to the convenience of commerce.\n\nIt would be really bad, for example, for a time zone boundary to cross in the middle of a city. It would help nothing, and cause a lot of problems.\n\nSo, whereever possible, the time zone boundaries are in rural areas where the economic impact of the time change is minimal.",
"Time zones are for the convenience of people, not a reflection of some absolute truth.\n\nThey generally line up with borders of nations & states. Inside a country, a small town might be put into the same time zone as a major city it's close to, even if the \"natural\" TZ border would have it on the other.",
"Longitude/latitude are precise measurements used for location. Time zones are a pretty modern invention to standardize times for business and transportation, and generally run along political borders.",
"A lot of people like a sort of perpetual daylight savings times. So a lot of the borders are farther west than they are naturally. ",
"Time zones became a thing in the US after railway travel became fast enough that it started to matter if \"noon\" in one town was a couple minutes different from \"noon\" in a town 20 miles away. When the time zones were standardized they were set up in such a way that the major railway companies would have all of their lines in the same time zones. These passenger railway companies are basically all gone now but their legacy lives on in the weird seemingly arbitrary way that our time zones are laid out.",
"Because countries are not straight and equidistant from each other. Even in the US, time zones mostly go around state borders so states can remain entirely in one time zone. "
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[]
] |
||
1t54it | why do some cars make springing, popping noises when parked after a long drive? | I hope people know the noises I'm talking about. As a kid I always noticed it from my moms van, and now experience the same noises from my own past cars(the newest of which is from 2002, so it may be an older car thing.) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1t54it/eli5_why_do_some_cars_make_springing_popping/ | {
"a_id": [
"ce4f1pv"
],
"score": [
5
],
"text": [
"The noises come from the exhaust components and heat shield. As they cool off, they contract and create the noises. It happens to all cars, but some cars may create more of these noises than others."
]
} | [] | [] | [
[]
] |
|
1php0t | if humans are multitasking capable, why is it not possible to count 2 different things in our head at the same time? (for example, heartbeat and seconds). | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1php0t/eli5_if_humans_are_multitasking_capable_why_is_it/ | {
"a_id": [
"cd2ejhw"
],
"score": [
5
],
"text": [
"We don't actually actively multitask. We shift our concentration from one idea/action to another. We can passively multitask however. Example: walking and chewing bubble gum."
]
} | [] | [] | [
[]
] |
||
17dkwx | acid vs. base? | One always thinks of acids as what burns. But I've learned that substances that are strong bases will do this too. Can someone ELI5 acid vs. base?
Bonus questions: would a neutral substance be equally good at counteracting both an acid burn and a base burn? Or would a strong base be best at counteracting a strong acid burn (and vice versa)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/17dkwx/eli5_acid_vs_base/ | {
"a_id": [
"c84jb9e",
"c84pnw4"
],
"score": [
14,
2
],
"text": [
"This might get a little tricky to try to explain to a five year old, and I'm certainly no university level scientist, but I'll give it my best shot in layman's terms:\n\nAcids and bases are two groups of chemical substances. They have different 'chemical properties': this means that when you put something into an acid, like some types of metals, they will react and produce new substances, such as hydrogen gas, whereas if you put a metal into a base, that will not happen. Another example of the differences in chemical properties of acids and bases is the way they taste - acids taste sour (think of lemon juice, which is an acid) and bases taste bitter (baking soda).\n\nAcids and bases can be strong or weak, as you hint at in your question. A weak acid, like vinegar, can splash on your skin and it will do nothing. But if you throw a concentrated dose of strong acid, like the kind you'd find inside a car battery, on your skin then you're going to have problems. So, very generally speaking, if a substance corrodes (destroys) or irritates your skin, it doesn't mean that it's an acid as opposed to a base; it means that you're dealing with a strong acid or a strong base. \n\nNow, you're probably asking, what does 'strong' mean? Here is the point when a five year old could start getting a little confused. First, we need to talk about water. Water, like every other substance that takes up space, is made up of particles called atoms, bonded together by special forces of attraction. The atoms are bonded together in groups called molecules. The molecules that make up water contain one atom of oxygen and two atoms of hydrogen - you've heard of H20, right? The molecules of H20 in water want to stay together because they're happy like that. The hydrogen and oxygen have a 'sharing is caring' kind of relationship with each other. If they didn't, then the water would no longer be water, but I digress - back to acids:\n\nAcids are substances made up of molecules too. Acids molecules all have hydrogen in them, just like water. Think of hydrogen as an important building block for both substances. Something interesting happens when you pour molecules of acid into water. Some of the molecules of acids kind of ... break up as they're floating around in the water. The hydrogen in some of the acid molecules goes and hangs out with some of the water molecules. Now, I'm grossly simplifying here, but water molecules as you remember are made up of hydrogen *and* oxygen; and oxygen is very good at attracting hydrogen. \n\nWhat happens in those acid molecules that do split up is that the hydrogen leaves the acid molecule because it's more attracted by the enticing oxygen in the water. What happens then? Well, instead of having H20, what you have now is essentially a H30 molecule. (We call this hydronium) Now, how many molecules of the acid split up and make hydronium depends on the acid. **A weak acid** will have few molecules that split up and not make much H30 in the water. **A strong acid** will make *lots* of H30. You should know at this stage that even pure water will make some H30 just by itself. It does this when hydrogen from the molecules of water are more attracted by the oxygen of another molecule of water nearby. Think of this as someone in a threesome ditching its partners to to make a foursome. This is why you may hear people say that water has acid like properties. This is because essentially an acid -- in a very general and oversimplified way -- is something that makes some molecules of water (H20) become molecules of hydronium (H30).\n\nOn the other hand, a base is a substance that will lower the number of hydronium (H30) molecules in water. This is because molecules of a base contain usually in their molecules, oxygen and hydrogen grouped together (OH^-). When you put a base in water, the oxygen and hydrogen in the base molecule say to the other atoms in the molecule 'see ya, losers!' and go looking for H30. If you're clever, you'll realize that the OH^- is going to pull away those extra little Hydrogens from H30 to make good old neutral H20. If you keep putting a base in water, you'll have more and more OH^- groups floating around in the water. A stronger base is not one with more OH^- in the water, but the one that will more readily pluck away the extra hydrogen from the H30 molecules.\n\nSo, how do we conclude this lesson? If you stick your hand in a beaker of acid dissolved in water, the strong acid is going to have created a lot of H30 molecules in that beaker. Unfortunately for you, the H30 molecules really like to play and make friends with the long Hydrogen-carbon molecules that make up your skin. You'll have a lot of jumping around of atoms as the H30 tugs away and rearranges the atoms that make up your hand. This is going to feel like it's burning your hand, but essentially what's happening is that the molecules of your skin are breaking down in the acid, making new molecules, and generally ruining your day. \n\nNow if you have a strong base, you'll know that it's a substance that's going to be very good at plucking hydrogens away. Hydrogen from the cells that make up your hand (and remember there's also a lot of water in you) are going to just love playing with all those OH^- groups, and a similar effect happens. Chemical reactions, sizzling, pain, bad times.\n\nTo address your bonus question using the snippet of what we've learned:\n\nWhen we think of a neutral substance, we need to think of pure H20. When you *neutralize * an acid or a base, what you're doing is trying to is get back to that pure H20 that will not react with the same things acids and bases do. \n\nNow think about this: if you poured pure H20 on acid molecules, is it going to turn the happy little H30 molecules back into H20? Nope! It's just going to **dilute** the acid. The nasty little H30 are still there and happy to burn your little paws off, mind you; they're just swimming amongst more H20 molecules.\n\nSo what do you need to do to make those H30 into pure, neutral H20? You're going to need something that plucks away those extra hydrogens. So, homework question is, what substances can do that for us? ",
"All acid molecules have a hydrogen molecule (H) that is susceptible to separating from the rest of the molecule. All bases have a hydroxide part (OH) that is susceptible to separation when they interact with something else. \n\nSo, hydrochloric acid (HCl) will split into a hydrogen atom (H) and a chlorine atom (Cl) when it gets mixed with, say water. \n\nA base on the other hand, like sodium hydroxide (NaOH - commonly known as Drano) would split into OH and Na when mixed with water. \n\nThere are a lot of properties that follow from this, but chemically speaking this is the difference. The reason water is neutral (H2O) is because it splits into H and OH, effectively exhibiting the requirements for both an acid and a base."
]
} | [] | [] | [
[],
[]
] |
|
2m3n6n | why is it so common to dream you are flying? | A common theme in dreams is to be able to fly, or at least hover at a small altitude. What causes it and why is it so common?
All the explanations I found have to do with desire for freedom or such, but I'd like to see other answers if possible. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2m3n6n/eli5_why_is_it_so_common_to_dream_you_are_flying/ | {
"a_id": [
"cm0nbs5",
"cm0nqm1",
"cm0q0e9",
"cm0r0pw",
"cm0wkfk",
"cm1dgc4"
],
"score": [
12,
2,
2,
3,
2,
2
],
"text": [
"I want to know why I have never had such a dream, but it seems everyone else has. ",
"Its probably to do with your mind interpreting the feeling of weightlessness during sleep. Similar to how your body feels like it drops into the bed when you jolt awake? Just a guess though :)",
"Sub-consciously, you brain replays past events throughout your sleep. The feeling of flying is closely related to being on a roller coaster, with the feeling of your stomach dropping, like in an elevator.",
"these explanations trying to tie in physiological causation aren't doing it for me. when i dream about flying there's always a positive emotion along with it, usually being astounded and then elation. and they are always really realistic feeling. i'm with op, i think there's some innate desire.",
"I keep on hearing about flying dreams that everyone has. I've never had a dream like that. The closest drew I had to that was a dream in which I could power jump...",
"I can come up with three reasons to why you want to fly when dreaming. \n**1.**It might be because you want to see the world in another point of view.\n**2.**If you feel like the flying is uncomfortable, maybe you want to get away due to poor self-esteem or other noteworthy reasons. \n**3.**If you like the feeling of flying and it is percieved as something good, you might yearn for simply something more fortunate in your waking life. (Like sex).\n\nIt is all psychological so I have no clue on why people dream about flying so commonly, but hey, it might be one of these reasons. \n\n-Wagenknecht\n"
]
} | [] | [] | [
[],
[],
[],
[],
[],
[]
] |
|
8why1t | why is virginity something you “lose”, or else “take” from someone else? where did this idea originate? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8why1t/eli5_why_is_virginity_something_you_lose_or_else/ | {
"a_id": [
"e1vn5hx",
"e1vnaj3",
"e1vpu0k",
"e1vroxp"
],
"score": [
10,
9,
33,
179
],
"text": [
"I don't know the orgin, but I always thought about it as innocence. Like virginity and innocence are almost interchangeable. \n\n\"He took her innocennce\" \n\"He lost his innocence to the family dog\"",
"Isn't it because it was literally taken from girls, whether through arranged marriage, rape and pillage etc.? What I'm getting at is that back in the day girls rarely had a choice in who 'took' it. ",
"These conceptualizations of virginity come to us from a history of European land ownership succession. In Europe, land was passed down father to firstborn son. With no DNA testing, the only way to \"ensure\" that your wife would give birth to your child and not someone else's was to make sure you were the first and only man she ever had. Considering women were literally regarded as property during this time, their worth was mostly determined by their ability to produce heirs you could trust to be yours. Add in a healthy dose of religious sexual repression and incurable STD's, and you've got yourself a great recipe for oppressing half of an entire species.",
"Because historically female virginity was something quite valuable and losing it or having it taken from you was a major thing with all sorts of implication beyond just sex.\n\nPeople put a lot of worth into virginity because the physical aspect of it was something that could be actually verified. It being the first time you had sex with your husband was something that could be noticed and if you kept the bloody sheets the couple could even prove it to others.\n\nThis was important because paternity was important, because family was important.\n\nBeing a virgin on your wedding night was seen as a pretty good indicator that any child born 9 month or a bit less down the road would be the husbands. That is important for questions of inheritance.\n\nOf course nowadays paternity and faithfulness are important too, but in those days there was no way to test paternity with DNA or even by comparing blood groups. Also in those days there was no real social welfare net. No unemployment benefits or anything like that you either had a family take care of you when you couldn't take care of yourself or you were mostly fucked.\n\nFamily was important because without the modern state taking care of people it was all they had.\n\nA girl's virginity was a bargaining chip that could be exchanged for a lifetime of benefits. It was worth quite a lot and carelessly giving it away or having it cruelly taken from you is a catastrophe that could destroy a lot.\n\nIt is why rape was seen as such a big crime in many cultures. Not because of the suffering of the woman, but because of the damage done to her family, especially her father if she was a virgin.\n\nIt is why in old stories women who have done the deed will talk about being ruined or no longer being fit for marriage. Or why even today people talk about \"taking responsibility\".\n\nIt is the general idea of \"you broke it - you bought it\". No one would want a bride who was not a virgin and thus the one who caused her to loose her virginity was expected to take care of her. It is why you get parts in the bible (and in older religious influenced law books), that have marriage as an out for rape or sex with a minor.\n\nEven worse in societies were there is no strong central authority to keep the peace people and families survived based on their reputation. Reputation or honour was a life or death thing in many societies. A girl who got a reputation for having lost her virginity, would not just reflect badly on her, but also on her family. Which is why extreme measure were often taken to avoid harm to ones honour and repair ones reputation. It is how you get honour killings.\n\nSo virginity was a matter of life and death in some cultures (and evens still is in some today) and even if you weren't in danger of being killed by your own family over losing it, you might still get cast out or at miss out on finding a good husband who (together with his family) would provide for you for the rest of your life.\n\nFor quite a lot of girls their virginity was the greatest treasure they ever had and giving it away was a very big thing.\n\nNowadays we have a culture of law instead of honour and we have forms of social security and employment opportunities for single women and paternity tests and a lot of other things that make the worth of ones virginity much less of a life or death thing, the language that has built up around it however survives."
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
2wd85s | why is getting water in the car engine bad? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2wd85s/eli5_why_is_getting_water_in_the_car_engine_bad/ | {
"a_id": [
"copqzcf"
],
"score": [
7
],
"text": [
"A car engine will compress air to about a tenth of it's volume before firing. If it sucks water in it cannot compress it. The momentum in the engine will cause the crankshaft to twist or the cylinderhead to fail."
]
} | [] | [] | [
[]
] |
||
28nbte | why is the un often accused of being corrupt? | Also how much has the organisation actually helped in the areas of peace and human rights? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/28nbte/eli5_why_is_the_un_often_accused_of_being_corrupt/ | {
"a_id": [
"cicj82j"
],
"score": [
2
],
"text": [
"Because the UN board has permanent members and rotating members. The permanent members (US, russia, etc.) can veto involvement in places where it isn't in their best interest (also why Taiwan can't claim sovereignty). "
]
} | [] | [] | [
[]
] |
|
21rlqi | what would happen if a plane tried taking off in an extremely hot atmosphere? like surrounded by fire | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/21rlqi/eli5_what_would_happen_if_a_plane_tried_taking/ | {
"a_id": [
"cgfuazv",
"cgfuklz",
"cgg0z49"
],
"score": [
3,
2,
2
],
"text": [
"Taking off when it's hot requires a faster takeoff speed, because hot air is less dense than cold air.\n\nFireballs usually travel **much** faster than an aircraft, so no, that wouldn't work.",
"A plane certainly couldn't operate inside a fireball, and it probably wouldn't go very far in a hot atmosphere like the one you described either. Looking just at the engine, the fuel would likely break down fairly quickly due to the increased heat which would mean the engines would not be able to produce enough thrust to keep the plane in the air. The engine oil would also break down, leading to failure of the bearings and then catastrophic failure of the engine. Raise the outside temperature high enough and the engine will begin to melt, although by that time the pilots, crew and passengers would probably be melting themselves. \n\nThat being said, planes and engines are more robust than most people imagine. You may be able to get away with flying through a relatively thin wall of fire, or a short exposure to a hot atmosphere, without suffering too much damage. \n",
"They would be delayed. Just like flights out of Phoenix on reallly hot days when the air is too thin for jet engines to perform within acceptable envelopes."
]
} | [] | [] | [
[],
[],
[]
] |
||
3lm98t | what happens in your brain when you are reliving a memory and stop paying attention to your sight. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3lm98t/eli5_what_happens_in_your_brain_when_you_are/ | {
"a_id": [
"cv7g3g1",
"cv7n2cn",
"cv7n2lf",
"cv7nou5"
],
"score": [
327,
8,
24,
4
],
"text": [
"If you've ever seen the Tim Burton Batman, there's a scene where the Joker breaks into a news broadcast, disrupting the programming that was originally playing. (There are other movies that have done this, but this is the first one that I remember.) The same thing happens in your brain, because memory isn't stored in some filing cabinet in a discrete location. Memory is composed of semantic and sensory details, and reliving a memory often involves the same areas of the brain. Since our eyesight and smell is the strongest of our senses, most of the sensory information of our memories involve that part of our brain. The thing is, our brain only has so much \"bandwidth\" to handle this information, so when a memory is recalled with enough strength, we sometimes \"space out\" or abandon the present. In people with severe PTSD, the memories are so intrusive that they're distressing, because while most of us can shake a memory off and go back to what we should have been doing (driving, listening to your spouse), someone with PTSD has a very, very hard time doing this. If the memory is traumatic enough, it can be recalled as a flashback; a memory so intense you interpret it as reality.",
"This one is surprisingly simple: \"visualizing\" something activates the same brain areas as actually seeing it. \n\nIn [this study](_URL_1_), for example, monkeys were trained to associate an arrow with visual motion. After the training, the arrow alone activated neurons in area MT, which normally respond to motion. \n\nWe don't know nearly as much about most senses as we do about vision, but the principle is very likely the same: imagining a thing and actually perceiving it are represented in the brain in similar ways. This means that remembering an experience activates purely \"sensory\" areas of the brain - areas that were once thought to do nothing but process input from the ears, eyes, etc.\n\nWhat's still a mystery AFAIK is how the two are different. Most people can easily distinguish between imagining something and actually seeing it happen, although it may be a problem for [some people](_URL_0_). Suppose the same \"sensory areas\" of the brain are active whether you're imagining something or it's right there in front of you. But there has to be *some* difference. Are the same sensory neurons responding differently to those two situations, or is your imagination sending another signal to some other part of your brain, to let you know that what's going on in the sensory part of the brain isn't real? (Pretty sure no one knows this, but I'd love to be proven wrong.)\n\n\n\n\n",
"Do people actually see things in their mind? When someone asks me to picture something, I'm assuming they're not being literal because I can't actually conjure an image in my mind. Is this a thing people can do?",
"If the images or sounds are real enough, the body can't tell the difference between the memory and present reality, and all the emotions can get triggered. \n\nA similar thing happens watching movies when your body gets excited and scared by a two dimensional image that you know is not happening, at least in the beginning. The image and its sounds become your reality in that moment. Sound is a dominant sense where emotions are concerned. Sight will engage your analytical side, but sound will knot your gut. Many of my Vietnam vet friends had severe PTSD triggered by sounds, some by touch.\n\nCheck out The Brain series on _URL_0_. The research on memory is fascinating."
]
} | [] | [] | [
[],
[
"https://en.wikipedia.org/wiki/Schizophrenia",
"http://www.ncbi.nlm.nih.gov/pubmed/17359922"
],
[],
[
"www.charlierose.com"
]
] |
||
46tov7 | how would this (cost effective 3d printed houses) affect the economy and housing prices in america's future when america starts doing it? | [story](_URL_0_)
So would that mean most people would be able to afford a big house because that mansion cost about $171,000 . Where im from you cant even afford a townhouse for that much.
are like mansions going to be the norm for living standards? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/46tov7/eli5_how_would_this_cost_effective_3d_printed/ | {
"a_id": [
"d07snav",
"d07tdka",
"d07tx1o"
],
"score": [
3,
5,
3
],
"text": [
"The cost to actually construct a house is only part of the total price. The price is based on what people are willing to pay, which will depend heavily on how much demand there is for houses in the area. A house that might sell for $10,000 in Detroit might go for $800,000 in San Francisco. It's not because it costs 80 times more to build a house in SF, it's just that there are far more people wanting to buy a house there than there are houses available, while Detroit is the complete opposite. Much of what you're paying for in SF is the land itself, because there are only so many housing lots in the city. ",
"A house is not just walls and roof. When you buy a house, you buy insulation, pipes, wires, air conditioning/furnace, windows, doors etc etc etc - it can't be 3d printed and cost tons of money.\n\nSo nothing's going to change.",
"its not the house itself as it is the property the house is located on. 10000 square feet in lincoln nebraska is much cheaper than 10000 square feet in manhattan. cheaper conztruction wouldn't change this much. there have already been tons of improvements over the last century to make construction quicker and cheaper, such as drywall replacing plaster, prefabricated insulated roof panels, and even prefab foundations. 3d printing is another step in this direction. all of these have made bigger, more spacious housing cheaper and more common. "
]
} | [] | [
"https://www.washingtonpost.com/news/innovations/wp/2015/02/05/yes-that-3d-printed-mansion-is-safe-to-live-in/"
] | [
[],
[],
[]
] |
|
8d0e06 | if diet alternatives to sodas are so common, why aren't there more "diet candy"? is it harder to produce? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8d0e06/eli5if_diet_alternatives_to_sodas_are_so_common/ | {
"a_id": [
"dxj8kev",
"dxj9czo",
"dxjddis"
],
"score": [
14,
3,
30
],
"text": [
"There are tons of sugar free candies produced. The issue is that the volume of sweetner needed to make candy appropriately sweet also tends to act as a laxative for many people. So you mostly see long lasting candies like hard candies and gums made with them rather than fast eating candies like chocolates or gummies (though they did have gummy bears for a while). ",
"Because there are no suitable alternatives that work well. Things like lollipops are basically just sugar, taffy is just sugar with some water to make it soft, gummy bears are just sugar and gelatin.\n\nWith these candies, sugar is 80-90%+ of the content, the artificial sweeteners are far too strong to work and if used the candy must be made out of almost nothing but fillers. I'm not aware of any fillers that give the proper texture and dissolve in your mouth as sugar does.\n\nThe ones that do exist are made by replacing the sugar with sugar alcohol, which has roughly the same flavor and texture, but it's basically just indigestible sugar, and it acts like a laxative (but they make stuff, like sugar free gummy bears with it). Some products can use Xanthium gum or other thickeners to get water pretty thick, so up to the thickness of jello, sugar free is doable (they make sugar free maple syrup this way). But you can't use it to make water rock hard like a lollipop.\n\nSoda is practically all water, so swapping out the sugar for artificial sweeteners makes it slightly thinner which you might notice, but it doesn't destroy the effect.",
"Most non-nutritive sweeteners (\"artificial sweetener\" doesn't include things like stevia which are natural) are *vastly* sweeter than sugar so you don't need near as much to get the same amount of sweetening power. Aspartame, for example, is 200x stronger than table sugar by weight.\n\nRegular soda is water + sugar + flavor. If you replace the sugar with something else, it's still just sweet water. It might have a slightly different mouthfeel but nobody's really going to notice much.\n\nMost candy, however, uses sugar to make up the physical structure of it. If you take all the sugar out of a Jolly Rancher, there's nothing left. Finding stuff that you can make candy out of that *also* has no calories and doesn't have negative affects on your digestive system is a bit trickier.\n\nBaked good, like cookies and cakes, are even harder to strip calories from. "
]
} | [] | [] | [
[],
[],
[]
] |
||
2jnm4z | ; in the event of a global disaster/disease etc like wwz or resident evil, how long would the internet be functioning? is there anything that would stop it at this point if you could reach an access point? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jnm4z/eli5_in_the_event_of_a_global_disasterdisease_etc/ | {
"a_id": [
"cldcpva",
"cldcr4n"
],
"score": [
2,
3
],
"text": [
"As long as there's power to the infrastructure. One of the first internets, ARPANET, was made to survive nuclear war. You need a working access point. If the power goes out and there's no backup generators, you wouldn't be able to connect. ",
"The internet would only function for as long as the computers that make it up are running. For example, if the webservers running reddit shut down for whatever reason, then reddit is no longer available to the internet, and the same applies to everything else connected. If your ISP's routing network is offline, then you and anybody else using the same ISP won't be able to access the internet."
]
} | [] | [] | [
[],
[]
] |
||
bbzj6i | how does bone cancer occur | I thought cancer cells moved through the blood? Are bones directly connected to vessels? Am i dumb | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bbzj6i/eli5_how_does_bone_cancer_occur/ | {
"a_id": [
"ekmm0dp",
"ekmzimy"
],
"score": [
4,
3
],
"text": [
"Bones are alive! They are indeed connected to the blood stream and actually play an important role in the development of the immune system. But they also contain living cells, wich can sadly become cancerous with various consequences.",
"Bones are actually the origin of most of your body’s ability to generate blood (hematopoiesis) within the bone marrow and they are highly vascularized (connected to blood vessels). It seems strange as we think of bone as very hard/dense and static but bone is constantly remodeled and recreated and in this process our body makes small canals through the bone so blood vessels can penetrate deep into bones (called a Haversian canal). \n\nInterestingly, as osteosarcoma begins and the bone cells become malignant (cancerous) they usually spread to the lungs which seems very strange. But considering both bone and lungs are highly vascularized, it makes sense and the cancer is actually spreading through the blood. Other organs of high blood supply are also at risk of metastasis (spread) such as the brain. \n\nMy favorite histology slide type is a bone slide prep and here’s just some interesting info too: \n_URL_0_."
]
} | [] | [] | [
[],
[
"http://www.histology-world.com/factsheets/bone1"
]
] |
|
2fza5m | how did i just drive normally for 20 minutes while lost in thought? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2fza5m/eli5_how_did_i_just_drive_normally_for_20_minutes/ | {
"a_id": [
"cke5as5",
"cke5gx4",
"cke5p1s",
"ckeedl9"
],
"score": [
6,
2,
4,
2
],
"text": [
"Your brain is really, really good at following routines. Things you do all the time, like driving a specific route, it can do on autopilot.\n\nThere was actually a study done where they took rats and measured how busy their brains were while they ran the same maze several times. After the first couple of runs, the rats had the maze down and their brains would go to a very low-activity state while they were negotiating it.\n\nBut I'm not saying it's safe to do that - you should probably avoid that \"lost in thought\" thing while herding a couple tons of steel.",
"Its kind of like being hypnotized/meditating. \n\n_URL_0_",
"You are actually paying attention, it is just nothing interesting enough to commit to long term memory is happening, besides what you were thinking about.",
"Muscle and mechanical memory also have a lot to do with it - it's the same way you can boil a kettle and make coffee while actively having a conversation, why a lot of smokers have a hard time quitting because they're so used to the mechanical action of picking up and inhaling, and why a lot of bachelors (like me) can shit / shave / shower in the morning when still drunk / badly hungover the following morning.\n\nConsequently, there's a whole niche of human error (written about mostly by James Reason), which defines how people manage to screw things up that they've done 1,000 times before on a daily basis, such as slips and lapses.\n\nSource: career in offshore oil and gas safety."
]
} | [] | [] | [
[],
[
"http://en.wikipedia.org/wiki/Highway_hypnosis"
],
[],
[]
] |
||
db84oq | how does a bank adjust its accounts after a robbery. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/db84oq/eli5_how_does_a_bank_adjust_its_accounts_after_a/ | {
"a_id": [
"f1z0jfz",
"f1z0l9u",
"f1zkr8b",
"f1zqbb8"
],
"score": [
3,
3,
2,
2
],
"text": [
"A bank will file for their insurance benefits that they have for this very scenario. Maybe some banks just write it off as an expense in small cases of petty theft.",
"It does not. Your bank account is not a pile of money the bank keep for you, it is a loan you grant to the bank. If they loose the money in a robbery or on the stock market, they still owe you the full amount.",
"The money in the vaults isn't tied to anyone personal accounts. It's just a way to help people liquidate what's in their accounts. All of our money in our accounts right now is virtual in that sense. So it's just the bank's money until someone comes in and asks for a withdrawal. \n\n & #x200B;\n\nSo if someone steals it its just the bank that has to note \"hey this much money was stolen from us\" and then they file an insurance claim. But most bank robberies usually only get a couple thousand dollars. When I was a teller we had rules about how much cash we could have in our top drawer and that's what you can grab the fastest. All of us working together would only be a few thousand dollars and even if you force open the big safe there's not that much beyond that. \n\n & #x200B;\n\nFor something like safety deposit boxes where people do put personal property, I'm not sure. I'm sure the bank has general insurance on those but someone keeping something really valuable in a box like that ought to have their own policies specifically mapped to whatever is in there.",
"The bank would have all it's cash money in a balance sheet assets account as \"petty cash\" or \"cash on hand\". All of the individual peoples accounts would be in a liabilities account as \"peoples bank accounts\". If the bank needed to reduce it's \"cash on hand\" asset account it wouldn't effect the \"people's bank accounts\" liability account. They would just reduce the asset and then show the hit on the income statement."
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
8q1tvb | why does the rain make plants and stuff look more green? | Is it just because the darker wet bark contrasts with the leaves and makes it look greener? Or does the rain wash off dust or something? Or does it look greener for the same reason wet bark is darker? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8q1tvb/eli5_why_does_the_rain_make_plants_and_stuff_look/ | {
"a_id": [
"e0frd1y",
"e0ft523"
],
"score": [
51,
9
],
"text": [
"It does indeed wash off the dust. It also coats over the rough surfaces, which contain tiny hairs (and other rough materials) that make the colors look a bit more grayish.",
"I think leaves absorbing water also changes which wavelengths (color combo) are reflected. This idea is used to retrieve vegetation index from satellite data."
]
} | [] | [] | [
[],
[]
] |
|
js9t8 | how sat's are supposedly "slanted against african-americans" | Apparently people think this. I don't understand how someone can slant a question so that, due to someone's skin color, they will answer incorrectly. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/js9t8/eli5_how_sats_are_supposedly_slanted_against/ | {
"a_id": [
"c2eporu",
"c2eq3lj",
"c2eqap3",
"c2er7ok",
"c2eporu",
"c2eq3lj",
"c2eqap3",
"c2er7ok"
],
"score": [
5,
7,
3,
5,
5,
7,
3,
5
],
"text": [
"[Stereotype threat](_URL_0_). Knowing that there is a stereotype out there that your race (or gender) isn't as good at what you're currently trying to do makes you stress out about confirming the stereotype if you do badly. Stressing out during a test makes you do worse.\n\nExample study: they took a group of people including white and black people, divided them into two groups randomly so that both groups had black and white people in them. They had them do a minigolf course (the same minigolf course for both groups), and they told group #1 that their performance would reflect their level of spatial intelligence, while they told group #2 that their performance would reflect their level of athletic ability. Group #1 had white people doing better than black people, group #2 had black people doing better than white people. The exact same course for both groups.",
"Like Graendal said, stereotype threat is one example. The other is that the SATs are written in a way that assumes a very specific kind of knowledge, one that is most often found in middle-or-upper class contexts and among European-Americans. By which I mean--asking questions that presume a certain way of thinking, or that use cultural touchstones, or that use terms or words that are used in \"classic\" English texts, etc. \n\nNot only did the test start out racist and sexist, but efforts are made to keep it slanted toward richer white students. The SATs constantly test new questions out on students (that's the ungraded section). They throw out the ones that black students are more likely to answer correctly than white students, but keep the ones white students are more likely to answer correctly than black students. \n\nJust googling \"SATs\" and \"racism\" will get you a lot of this information, but an easy to understand and well-researched essay on the topic is [here](_URL_0_).",
"Consider this question:\n\nCup is to saucer as plant is to ______\n\nA. Leaf\n\nB. Stalk\n\nC. Root\n\nD. Flower\n\nSeems like a simple, fair, and straightforward question, right?\n\nWell, what if you grew up in a poor home, where you didn't have matching sets of cups and saucers? What if you grew up in an inner city area where you don't see a lot of plants? What if English is your second language?\n\nYour background will make it harder to understand what the question is getting at. It has nothing to do with skin color itself, but with cultural and economic factors often linked with race. ",
"I'm going to have to break the mode of ELY5 because there appears to be a fundamental interpretation error.\n\n\"slanted against african-americans\" does not equate to \"racist\", which is what you appear to think in your responses to well-written comments. Correct me if I err.\n\nNeither does it mean that\n > due to someone's skin color, they will answer incorrectly\n\nAs you state, that would be racist because your statement claims that the person's race **causes** them to answer incorrectly. ([Relevant](_URL_0_) and amusing). However, this is not what \"slanted\" means.\n\n\"Slanted\" in this context means that some people are more likely (holding other relevant factors constant) to get a question wrong if they are of a certain group. I repeat, \"more likely\" is claim of correlation, **not** causation. Since there are cultural and socioeconomic factors at play when interpreting questions of the SAT *and* the SAT is supposed to be independent of those two factors (among others), it is possibly correct to say that the SAT is \"slanted\".\n\nNow that I've said that, here's the ELI5 version:\n\n\"slanted\" doesn't mean racist. The people who write the test would obviously get fired if they wrote mean questions like that. Sadly, sometimes just because you're from a certain family, or just because you're poor, you know different things than if you were from a different family. Sometimes you don't even you know different things. And it's important to know that knowing different things doesn't mean you're better or worse; it's just different. The people who write the SAT are usually from better-off families and so when they write the questions, they write questions with words they understand and sometimes other people don't know those words.\n\nTake your friend Jimmy from school for example; his family doesn't use expensive china because they can't afford it. Your friend Spencer's family uses his great-grandmother's china. I'd be willing to bet that out of 1000 Jimmys, fewer would know what the word \"saucer\" meant compared to 1000 Spencer. It's just what words they know; it doesn't mean Spencer is better than Jimmy.\n\nNow in the real world, because people don't always see things clearly, black people had it really hard in America in the past because white people were mean to them. Now things are better, but black people are still catching up. Again, we know they aren't better or worse for it; it's just the effects of history that are still around.\n\n(I hope the ELI5 version isn't racially charged too badly…)",
"[Stereotype threat](_URL_0_). Knowing that there is a stereotype out there that your race (or gender) isn't as good at what you're currently trying to do makes you stress out about confirming the stereotype if you do badly. Stressing out during a test makes you do worse.\n\nExample study: they took a group of people including white and black people, divided them into two groups randomly so that both groups had black and white people in them. They had them do a minigolf course (the same minigolf course for both groups), and they told group #1 that their performance would reflect their level of spatial intelligence, while they told group #2 that their performance would reflect their level of athletic ability. Group #1 had white people doing better than black people, group #2 had black people doing better than white people. The exact same course for both groups.",
"Like Graendal said, stereotype threat is one example. The other is that the SATs are written in a way that assumes a very specific kind of knowledge, one that is most often found in middle-or-upper class contexts and among European-Americans. By which I mean--asking questions that presume a certain way of thinking, or that use cultural touchstones, or that use terms or words that are used in \"classic\" English texts, etc. \n\nNot only did the test start out racist and sexist, but efforts are made to keep it slanted toward richer white students. The SATs constantly test new questions out on students (that's the ungraded section). They throw out the ones that black students are more likely to answer correctly than white students, but keep the ones white students are more likely to answer correctly than black students. \n\nJust googling \"SATs\" and \"racism\" will get you a lot of this information, but an easy to understand and well-researched essay on the topic is [here](_URL_0_).",
"Consider this question:\n\nCup is to saucer as plant is to ______\n\nA. Leaf\n\nB. Stalk\n\nC. Root\n\nD. Flower\n\nSeems like a simple, fair, and straightforward question, right?\n\nWell, what if you grew up in a poor home, where you didn't have matching sets of cups and saucers? What if you grew up in an inner city area where you don't see a lot of plants? What if English is your second language?\n\nYour background will make it harder to understand what the question is getting at. It has nothing to do with skin color itself, but with cultural and economic factors often linked with race. ",
"I'm going to have to break the mode of ELY5 because there appears to be a fundamental interpretation error.\n\n\"slanted against african-americans\" does not equate to \"racist\", which is what you appear to think in your responses to well-written comments. Correct me if I err.\n\nNeither does it mean that\n > due to someone's skin color, they will answer incorrectly\n\nAs you state, that would be racist because your statement claims that the person's race **causes** them to answer incorrectly. ([Relevant](_URL_0_) and amusing). However, this is not what \"slanted\" means.\n\n\"Slanted\" in this context means that some people are more likely (holding other relevant factors constant) to get a question wrong if they are of a certain group. I repeat, \"more likely\" is claim of correlation, **not** causation. Since there are cultural and socioeconomic factors at play when interpreting questions of the SAT *and* the SAT is supposed to be independent of those two factors (among others), it is possibly correct to say that the SAT is \"slanted\".\n\nNow that I've said that, here's the ELI5 version:\n\n\"slanted\" doesn't mean racist. The people who write the test would obviously get fired if they wrote mean questions like that. Sadly, sometimes just because you're from a certain family, or just because you're poor, you know different things than if you were from a different family. Sometimes you don't even you know different things. And it's important to know that knowing different things doesn't mean you're better or worse; it's just different. The people who write the SAT are usually from better-off families and so when they write the questions, they write questions with words they understand and sometimes other people don't know those words.\n\nTake your friend Jimmy from school for example; his family doesn't use expensive china because they can't afford it. Your friend Spencer's family uses his great-grandmother's china. I'd be willing to bet that out of 1000 Jimmys, fewer would know what the word \"saucer\" meant compared to 1000 Spencer. It's just what words they know; it doesn't mean Spencer is better than Jimmy.\n\nNow in the real world, because people don't always see things clearly, black people had it really hard in America in the past because white people were mean to them. Now things are better, but black people are still catching up. Again, we know they aren't better or worse for it; it's just the effects of history that are still around.\n\n(I hope the ELI5 version isn't racially charged too badly…)"
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Stereotype_threat"
],
[
"http://www.alternet.org/story/13826/"
],
[],
[
"http://xkcd.com/552/"
],
[
"http://en.wikipedia.org/wiki/Stereotype_threat"
],
[
"http://www.alternet.org/story/13826/"
],
[],
[
"http://xkcd.com/552/"
]
] |
|
33jgbo | why are there restrictions on liquid containers for planes? i know an attempted terror attack caused it, but how does it make sense? | [found this on r/funny](_URL_0_)
It's actually quite true, you can bring lots of small liquid containers, but not one big one. I know hydrochloric acid is a popular way of mutilating people and you could easily fit it into a tiny can of deoderant, or several cans of deoderant, so how would taking a large bottle of contact lens fluid really help things?
I'm convinced it's an elaborate charade to make sure I buy my liqours and liquids at the airport's shops | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/33jgbo/eli5_why_are_there_restrictions_on_liquid/ | {
"a_id": [
"cqlgmbs",
"cqlh58p",
"cqlha0v"
],
"score": [
2,
2,
3
],
"text": [
"It does not make sense. It's only in the US, where TSA is a bunch of old guys on a power trip. ",
"On the contrary, Smaller containers = smaller amount of substance that is brought into the plane. Even if its a lot of bottles, n * 30ml of X substance (even if its water) is a controlled substance that is being brought into the plane. \n\n1) Very hard to make any quantifiable damage in such quantities.\n2) Quite a lot of effort needed to prepare N*30ml substances into 1 harmful substance. \n3) Harmful/Dangerous substances are usually spectroscoped as they are X-ray(ed) and they tend to light up like a Christmas tree in the software ... (even if there are loads of people carrying the same harmful substance in the airport, the software keeps count of this and there is a deterrent process in place). \n4) Really easy to make people just follow the guidelines, for general safety, but in the process scaring the shit out of them.( but that's collateral damage and capitalism can exploit that if its wants to) \n\noh and aerosol-ing (Proudly invented word ) acid is very hard, the pressures needed would be quite high, and quantity, not that high to do significant damage. You'd need about 20 cans or so that are allowed by the airports to go through, in order to make some dent in security concerns.",
"The reason for the ban on containers of liquid is due to the possible use of liquid binary explosives. When you are getting ready to board a plane alot of times you will be subject to scanners and bomb sniffers. Because binary explosives aren't detectable until they are mixed in a lot of cases they can slip through the screening process. You can make an explosive powerful enough to blow a hole in the fuselage of a plane and cause rapid depressurizaton with as little as 16 ounces of binary explosive and new ones are always being synthesized so that number could very well be smaller."
]
} | [] | [
"http://i.imgur.com/75dBsHx.jpg"
] | [
[],
[],
[]
] |
|
4jnxfc | are there any species that are both sexually and asexually reproductive? | If so, how do they fare? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4jnxfc/eli5_are_there_any_species_that_are_both_sexually/ | {
"a_id": [
"d384ah1",
"d384ncd"
],
"score": [
3,
2
],
"text": [
"Well, many flowering plants are. They have both male and female parts, they can pollinate themselves, or others. And they fare pretty well.",
"There are some species that can alternate between both sexual and asexual reproduction. There are some insects such as Aphids that will sometimes lay eggs without fertilization thus cloning themselves. The Cape Bee can also do both. They do it mainly through a process called Thelytoky (when the eggs are laid and not fertilized but still produce). There are some species of amphibians, reptiles, and birds that a capable to. For example, the freshwater crustacean Daphnia reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to sexual reproduction as the intensity of competition and predation increases. Another example are monogonont rotifers which reproduce via cyclical parthenogenesis: at low population densities females produce asexually and at higher densities a chemical cue accumulates and induces the transition to sexual reproduction. So for some species it depends on the conditions they are in if they reproduce sexually or asexually."
]
} | [] | [] | [
[],
[]
] |
|
aageh4 | i recently got into a physical altercation where afterwards i had to explain the situation and my voice was shaky and words wasn’t forming at all. no matter how hard i tried to slow down . and i tried to sit down and but my leg shook uncontrollably, why did those two things occur ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aageh4/eli5_i_recently_got_into_a_physical_altercation/ | {
"a_id": [
"ecrst02",
"ecrsudh",
"ecrsxue",
"ecrt2qr"
],
"score": [
14,
3,
3,
2
],
"text": [
"Adrenaline dump. Your body reacted to a dangerous situation by dumping adrenaline and other hormones into your system, so that you could fight or fly. It can take an hour or more to clear. Your trying to calm a fire your body just poured gas on. You're also shunting blood from your brain, which you don't need right now, to other areas which you do, like your heart lungs and legs. Trying to describe it by visualizing the events keeps your body in fight or flight mode.",
"Fight or flight floods your body with chemicals that makes you run full throttle, and it may take a while for it to leave your system",
" I literally sounded like two people trying to talk over the phone at the same time",
"Adrenaline. In response to a sudden and dangerous event (like your altercation), your brain tells your adrenal gland to release adrenaline. The adrenaline gives you a rush of strength and energy to help you win a fight, escape from a tiger, etc. Immediately afterwards the adrenaline was still in your bloodstream so you still had extra energy. You couldn't shut it off until the adrenaline was gone, which is why you were shaky and jittery."
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
292kqb | cold welding in space | I recently read a short article about cold welding in space. Where if you touch to like metals together (ex copper on copper) they stick together. How and why does this happen? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/292kqb/eli5cold_welding_in_space/ | {
"a_id": [
"cigts8w",
"cigu7l9"
],
"score": [
3,
4
],
"text": [
"On earth, metals are almost always covered by a very thin film of oxide. This means that actual metal-to-metal contact is rare.\n\nIn space there is no atmosphere to provide oxygen, which would renew the oxide coating. When the oxide wears off, and you press the metals together, there is true metal-to-metal contact. Since the metal surfaces are not microscopically smooth, the pressure is all taken out on a small number of microscopic high spots, and the metals simply unite at these points.\n\nYou can try a similar effect in your own kitchen. Take a couple of ice cubes, let them warm up a bit, then press them together. They will weld into a single lump. Water already has all the oxygen in its molecule that it can accept, so it cannot oxidise further. ",
"So, you've probably heard of covalent and ionic bonds. In covalent bonds, the force of attraction that shared electrons cause binds atoms together. In ionic bonds, the positive charge of one atom attracts it to the negative charge of another.\n\nHowever, there's a third kind of bond: metallic. In metallic bonds, metal atoms are kept close to each other so electrons can freely move between them. The attraction between these electrons and all of the metal nucleuses keeps them held together. Metallic bonds are also responsible for the conductivity of metals.\n\nSo, if you touch any raw metal to another raw metal, they will fuse together instantly in a metallic bond. But this obviously doesn't typically work on Earth; otherwise, we could just press metals against each other to weld them together. If a metal is exposed to oxygen (of which there's an abundance in our atmosphere), its outer surface will oxidize -- the metal will form covalent bonds with oxygen. As electrons cannot flow through covalent bonds as easily as they can through metallic bonds, the whole contact-fusing property is done with. It only works when two metals can bond with each other and oxygen makes that impossible. What welding on Earth actually does is it burns away those oxygen bonds on the outer layers of metals and lets the raw metals fuse with each other.\n\nNow, if we were to remove the oxygen-laden atmosphere -- say, put the raw metals in space -- then we don't have to worry about covalent bonds and can just tap metals together to weld them. This would also work in a vacuum chamber on Earth, but it sounds a lot cooler to weld *in space*.\n\nThis is my first ELI5 answer. If you need any more clarification, just ask."
]
} | [] | [] | [
[],
[]
] |
|
8rkkc9 | why do city birds sing at night? do the city lights prevent them from ever sleeping? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8rkkc9/eli5_why_do_city_birds_sing_at_night_do_the_city/ | {
"a_id": [
"e0sn0we",
"e0t3lgq"
],
"score": [
3,
2
],
"text": [
"Birds in/around large human populations usually adapted \"singing\" before humans wake up, simply due to the fact that their shouts will not be overwhelmed by the sounds of the cities... a Bird is much easier to hear at 5am than at 12pm or during rush hour... not only can WE hear them more, but they can hear EACHOTHER",
"Male Mockingbirds that don't have a mate will sing all throughout the night. It can be very annoying to humans trying to sleep! They mimic songs of other birds (and sometimes even alarm clocks and car alarms). "
]
} | [] | [] | [
[],
[]
] |
||
a1on3q | why dont humans replace teeth more than once like animals such as sharks do? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a1on3q/eli5_why_dont_humans_replace_teeth_more_than_once/ | {
"a_id": [
"earhqj5",
"eark2d1",
"earlz01"
],
"score": [
8,
8,
5
],
"text": [
"Humans have bred all the children before their second set of teeth wears out. That means there is no evolutionary pressure to have more sets. Other long-lived mammals do have multiple sets of teeth, elephants for example have 6 sets, but the infinite regeneration seen in fish are not present in mammals, as far as I know.",
"Humans, like most mammals, only have two sets of teeth through-out their lives. This trait most likely evolved in mammals (many early mammal ancestors did grow multiple sets of teeth) because of the way we learned to chew our food. To be able to do that, you need strong, durable teeth that are ankered in your jaw. Else you just can't grind down food properly. So along our evolutionary line, we traded in the ability to grow multiple (less sturdy) sets of teeth in favour of having fewer sets up teeth that can go the distance, so to speak.\n\nIf you look at animals that replace their teeth frequently, you'll notice that they don't really chew their food. Most can't. They just tear and swallow things whole. ",
"Simple sharks do not have teeth.\n\nWhat we call a sharks tooth is in fact a modified placoid scale.\n\nAs it is a scale it regenerates regularly as all other scales do. \n\nHumans have teeth and all said teeth are present at birth.\n"
]
} | [] | [] | [
[],
[],
[]
] |
||
1nenie | why are tobacco products behind the counter, while alcohol is on shelves in stores? | I don't understand why tobacco is behind counters and you have to be 18, and alcohol is on shelves in the store, available for everyone to see, but you have to be 21? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1nenie/why_are_tobacco_products_behind_the_counter_while/ | {
"a_id": [
"cchvfjn"
],
"score": [
8
],
"text": [
"It's easier to steal a small package than a large bottle"
]
} | [] | [] | [
[]
] |
|
1c8bwo | how can this guy drink this much alcohol at once at not die? | _URL_0_
I'm watching this video and apparently this guy Shoenice is the real deal. These aren't fake stunts. How in the world can one person consume this much alcohol at once at not die?
*Sorry for bad title, meant to put and instead of at. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1c8bwo/eli5_how_can_this_guy_drink_this_much_alcohol_at/ | {
"a_id": [
"c9e0hr5",
"c9e16gi",
"c9e3fcv",
"c9e42jn"
],
"score": [
6,
3,
3,
4
],
"text": [
"I have to assume he immediately went and threw it all up. It would probably kill him if he didn't.",
"That or it's fake.",
"[Here's a little documentary](_URL_0_) about him. He says he has been drinking from an early age and always had an unusually high tolerance, but still suffered some health problems resulting from at least one of his liquor chug videos.",
"I'm gonna take a crack at figuring out if that was a survivable dose, assuming he actually didn't throw it up after the video (which is more likely).\n\na lethal BAC is somewhere between 0.4% and 0.5% for a normal person. So lets figure out how many drinks it takes to get a person of Shoenice's build (approximately 200 lbs?) to lethal level. A man ShoeNice's size (200+ lbs.) should be able to consume something like 20 drinks (in a short period of time) before he's near the lethal range of BAC. \n\n\"1 drink\" is typically considered to be about 0.5 ounces of alcohol content in the drink. That bottle of everclear looks to be about 750 mls, which is about 25 ounces. If he drank the _ENTIRE_ bottle it would be like 50 drinks and he'd just die. He might have credibly chugged as much as 1/4 of the bottle and still had a chance to survive it. In the video he clearly chugged more than 1/4 of the bottle. It was not a survivable dose. He pretty much have to conclude that he threw it up immediately after drinking it. \n\n[source](_URL_0_)"
]
} | [] | [
"http://www.youtube.com/watch?v=s2nRWP10HEA&lc=b8NEOdD4ykysMzn1BT42Zp5ufYhAw1x3RJyEFHbD71c"
] | [
[],
[],
[
"http://www.youtube.com/watch?v=AsHaE6F-nr8"
],
[
"http://www.clemson.edu/campus-life/campus-services/redfern/alcohol/bac.html"
]
] |
|
3eez0l | eye color | I am a white male with blue eyes, my GF is Mexican with brown eyes. What is the chance of us having a blue eyed baby? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eez0l/eli5_eye_color/ | {
"a_id": [
"cteavjq",
"ctec7f9"
],
"score": [
2,
2
],
"text": [
"Well, it isn't just a matter of what you and your partner have. There's a chance that there are some recessive genes that simply aren't showing up in either of you. To get a better idea of the actual chances you have to go back at least one generation to both of your parents. Here's a handy calculator that should help: _URL_0_",
"Since you have blue eyes, you likely only have genes for blue eyes. Blue eyes are recessive. In your girlfriend's case, though, it's conceivable that she may have one gene for brown eyes and another gene for a different color, but the other color is unexpressed, because recessive. However, if she has had no ancestors with anything but brown eyes, then it's probable that she has genes only for brown eyes. That means any child of yours would have a gene for brown eyes and a gene for blue eyes, making the child's eyes brown. But eye color is not a simple mendelian train. With a gene for brown eyes (that is, a gene that causes the production of a lot of pigment in the eyes) and a gene for blue eyes (a gene that causes the product of no pigment in the eyes), your child might end up with an eye color part way between blue and brown. That is, light brown or hazel."
]
} | [] | [] | [
[
"http://genetics.thetech.org/online-exhibits/what-color-eyes-will-your-children-have"
],
[]
] |
|
1r1n28 | what set apart google from yahoo, facebook from myspace (etc.) such that one failed where the other succeeded? | I remember a time when Myspace was big while Facebook was just coming up, a time when "Yahoo and Google" would be mentioned in the same sentence often enough. Yet now in hindsight, Google and Facebook clearly won out, while Yahoo/Myspace were to most either forgotten or relegated to uses secondary to their initial offering.
So, my question is: What did Google do right that Yahoo didn't do or did wrong? What key decisions let Facebook transcend the [network effect](_URL_0_) to eventually outpace Myspace? In short, **what key factors played a role in determining the outcome of these competitions?**
It can't just be that "they were the new thing," or else we'd see the same effects with G+ and basically any "next big social website" out there that got some views. What exactly set apart/determined which of a pack of sites is the last one standing? (I know Myspace and Yahoo are technically still around but they're basically non-existent now...) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1r1n28/eli5_what_set_apart_google_from_yahoo_facebook/ | {
"a_id": [
"cdintll"
],
"score": [
2
],
"text": [
"For me both were based on the lack of clutter. I never joined myspace because it was a cluster fuck and google was very simple and always gave me results without spamming the page full of non-sense. A lot of it has to do with how it was managed by the top level directors but for me this was a very important factor which I'm sure played a major role for others as well. Also, yahoo is FAR from extinct."
]
} | [] | [
"http://en.wikipedia.org/wiki/Network_effect"
] | [
[]
] |
|
700u7m | how do manufacturers of vehicles make car keys that are unique such that not 1 car key is identical to the other? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/700u7m/eli5_how_do_manufacturers_of_vehicles_make_car/ | {
"a_id": [
"dmzivga",
"dmzj12f",
"dmzj3uu",
"dmzj5zs",
"dmzjw53",
"dmzk3zz",
"dmzm132",
"dmzms06"
],
"score": [
14,
5,
2,
2,
2,
5,
2,
6
],
"text": [
"Certainly with normal keys, it's more than possible that there do exist keys that will open more than one lock, but the whole security of a lock and key is that you don't know that. \n\nOr put another way, if you were to find a random key at the side of the path one day and pick it up, would that make you any more likely, in the grand scheme of things, to be able to get into the house it came from? No, because you don't know which house that is. Could be any one of millions of keyholes. \n\nCars are the same. Odds are with the number of cars in the world, there are certainly keys that are duplicated somewhere, but how do you know where and what cars? You have no way of knowing. ",
"The trick is that they don't. They just need to make them unique enough that most keys do not fit. So there will be less accidents with people taking the wrong car and it is not convenient for car thieves to carry around a full set of keys. But that means that you might just need to make less then hundred unique keys for all the cars. Modern cars with radio chips in the key does have an added level of security as these often have a lot more unique patterns then physical keys.",
"If you're talking about physical keys, [they don't make them unique.](_URL_0_) They simply have enough different combinations that it is highly unlikely that you would ever find out if another car around you was using the same key. ",
"They don't.\n\nI distinctly remember someone talking of having a brand new car, going into the parking lot, blipping their car and an exact duplicate down to the colour and model responded.\n\nThe two drivers compared in amazement.\n\nI assume the manufacturers don't envisage it happening often enough to be a security risk.",
"One time my father and I got into the wrong car because he had this neon green Toyota I've never seen anyone else with. He was parked within the vicinity of the corner or the parking lot at our local mall-- we managed to notice within about 10 seconds that it didn't feel right.\n\nIt was a bit interesting for me since I was about 10 st the time!\n\nThere are definite key dupes ",
"Once upon a time I did accidentally open a car of the exact same make, model and color with the key to our family's car. It was in the parking lot of a mall and they were parked just a few cars away from ours. This was two decades ago before car remotes became popular.\n\nNowadays many manufacturers use laser cut keys which gives a pattern unique to each car, nearly eliminating the possibility of producing identical keys.",
"I worked at a local dealer for over 12 years and in that time twice we had to do a wärranty swap of ignitions. One a person either unlocked a matching vehicle at a mall parking lot and only realized as they went to back out and saw a kleenex box on the rear shelf. He left the owner a note explaining the event and later found out that he knew said owner. The second one was a buddy showing off his new car to the guy who bought one a few weeks earlier and for the hell of it they tried each others keys and yup they worked. Now these were both in the days before chipped ignition keys. It really is more common than one would think.",
"Certified Registered Locksmith of nearly 10 years here. Newer cars are getting better about this. Manufacturers are moving away from physical keys, to remotes and push to start systems. This is decreasing the likelihood that a random person will be able to accidentally access your car. \nFor older models that utilized pin tumblers that utilized cuts on the edge of the key as opposed to the face, it was common for manufacturers to only use a fraction of the key bitting for different locks on the car. The ignition would use the most, while the glove compartment might only use three, and the doors use five of a different combination, and the trunk will use a different combination of four or five as well. This worked because many keys had 8 cut positions. Ford, for example had 8 positions, with 4 different depths. This leads to nearly 65,000 different theoretical key combinations. Not all 65,000 could be used to to physical restrictions of the keys. It might not be possible for a deep cut next to a shallow cut on some manufacturers, or some manufacturers have specific rules about their key bittings. \nWith all that being said, car manufacturers do their best to make sure that you are the only person near you with a key to your car. But sometimes you may get an anomaly. But the likelihood of that happening is very small. Plus the transponder in the key is unique and must be programmed into the car. \n\nTldr: it is possible for cars to have keys, other than those with the car, to have identical cuts. However, vehicle manufacturers do what they can to limit this and electronic security is helping"
]
} | [] | [] | [
[],
[],
[
"https://www.aol.com/article/2015/07/07/does-your-car-key-have-a-twin/21206195/"
],
[],
[],
[],
[],
[]
] |
||
1vkyc0 | does having more blades on a helicopter make a difference? | Title mostly says itself. So if one was to have 4 blades as opposed to 2 blades on a helicopter, would it make a difference?
EDIT: To clarify, I mean in terms of speed or height or other things | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vkyc0/eli5_does_having_more_blades_on_a_helicopter_make/ | {
"a_id": [
"cet9xrp",
"cetad0a",
"cetcnrj",
"cetd2ue"
],
"score": [
13,
9,
2,
3
],
"text": [
"It would make a difference. But what difference? That extremely complex to answer.\n\nMore blades would be capable of lifting more weight.\n\nBut after that, you need to know the exact details of the blades and the helicopters to know what effect it will have. It will almost certainly affect the noise of the helicopter. It will affect its empty weight, and, because of that, perhaps its handling characteristics. You might also find that each blade gets caught in the down wash from the previous blade, which will alter how effective each blade is. It will also increase manufacturing and maintenance costs.\n\nYou can be pretty sure, though, that the designer has taken into account the intended usage of the helicopter and designed it with the number of blades which is the best compromise for the job it's going to do.",
"Each blade generates lift proportional to its area and the rpm it's spun at, right?\n\nSo, take two hypothetical copters with blades of equal length, but one has four blades and the other has two? Four blades should generate a good deal more lift, but very likely less than twice as much. Fluids get turbulent; turbulence eats efficiency.\n\nPushing the blades through air creates resistance. This requires horsepower to overcome, so the four-bladed copter will require a more powerful engine to spin its rotor at the same rate. It probably requires slightly more than twice as much power to spin four blades as it does two, not to mention that now you have to lift a heavier engine.\n\nSo copter designers must find optimal \"sweet spots\" in compromising between number of blades, power (and thus weight & bulk) of engine, and other attributes of the craft. Most are designed with pretty specific functions in mind, so it might help you to read up on for example the difference between a cargo moving helicopter and one intended for anti-tank combat. They're both technically helicopters, but with completely different design priorities.\n\nForm follows function. Engineers are some clever people.\n",
"The speed limit of a chopper is directly affected by the maximum speed of the tip of the rotor on the forward moving side. If its speed relative to the air approaches supersonic speed you'll get nasty aerodynamics, so you can't get above that.\n\nAn increased number of rotor blades has improved lift compared to a rotor with less blades that is otherwise identical, but also uses proportionally more power (is less efficient)\n\nTherefore you can achieve the same lift at lower RPM or more lift at the same, allowing you to increase the speed limit or maximum weight while maintaining the same speed at the cost of efficiency\n\nIncreasing rotor diameter has similar effects minus the hit in efficiency, but of course there is a limit to how much you can increase the rotor diameter, and it may affect handling in a negative way\n\nedit: Grammar\n",
"Generally, if we assume the helicopter has the same amount of power, rotor shaft rpm, weight etc and you only change the number of blades and the rotor diameter;\n\nHaving more blades allows you to use a smaller diameter rotor to get the same lift, which means the tip speed is reduced, and the helicopter can fly faster. If you wanted to lift a large payload with only two blades you could either use a very large diameter rotor or spin the blades faster. Both of these options will mean the blade tips will be approaching or higher than supersonic airspeeds, which can be cause catastrophic vibrations and buffeting. It also limits the top speeds, because even if the blades aren't already transonic, as soon as you have any forward speed, the proceeding blade will go transonic.\n\nGenerally no more than 5 or 6 blades are used on the same rotor, because more blades results in less efficiency. This is due to the following blades flying through the previous blades wake. Once you go above a certain number of blades (I don't know exactly, because it probably changes for different helicopters) the added lift is negated by the reduced efficiency of all the blade.\n\nFor altitude you want as much lift as possible and to get that out of the same amount of power you want the most efficient blade configuration, which is usually the lowest number of blades you can get away with. But helicopters normally don't even have pressurized cabins, so you fly up until the pilot passes out.\n\ntl;dr: More blades allow for higher speeds up to a point were the reduction in efficiency results in minimal advantage."
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
5zkayt | why is heaven most commonly referred to as being up above the earth while hell is most commonly referred to as being down below the earth or in the ground? when did this tradition come about? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5zkayt/eli5_why_is_heaven_most_commonly_referred_to_as/ | {
"a_id": [
"deyqehd",
"deyqjqp",
"deyr5c4",
"dezkvya"
],
"score": [
11,
4,
7,
2
],
"text": [
"It's really old. The ancient Egyptians had this notion, 5000 years ago. The Jews, and then the Christians, and then Dante colorized them as we think about them today, but the idea goes way back.",
"Many early religions and the basis of modern religion appears to be based upon worship of the sun. The sun of course is in the sky and appears to go away \"into the ground\" as the sun sets. Celebrations centering around the solstices or lunar cycles highlight this relationship to celestial bodies.",
"There is a certain logic to the heavens being above us. The Greeks reasoned that the heavens were very different from the Earth, being ordered and not subject to decay. It was thought that the heavens were composed of an entirely different type of matter (aether) than the four elements that made up the Earth.\n\nAstronomical observations eventually disproved this view, Newton showed that the law of gravity explained the orbits of the planets and other solar system bodies, and spectroscopy proved that stars were composed of the same elements as found on Earth. Also, that our Universe is in a constant state of change and evolution, but on its own rather than a human timescale.",
"It's because of the stories of the Bible. In the Bible it states that God created a vault to separate waters from waters (ocean from weather) and that God looks down upon us from far above, above another vault separating sky from heaven (this vault is space)"
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
22rhwz | given that life has existed far longer in our oceans than on land, why hasn't there been species that evolved with the same intelligence level has higher primates? | An earlier question concluded that dolphins are an example of an aquatic intelligent species and yet humans have been far more successful. This also doesn't account for the fact that life existed in our oceans far, far longer than it has on land.
Basically, I want to know why we aren't having epic battles with mermen for rule over Earth. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/22rhwz/eli5_given_that_life_has_existed_far_longer_in/ | {
"a_id": [
"cgpnz7n",
"cgpps2d",
"cgppxd8",
"cgpr6wv",
"cgpr9yn",
"cgpt27y",
"cgptck0",
"cgpwy68"
],
"score": [
25,
67,
6,
2,
2,
9,
3,
6
],
"text": [
"Human-style intelligence, while very cool, is not easy to evolve, and it is not free. It requires a lot of energy to run our brain, for example, and in an environment without fire, and where communication is harder, that cost may not be worth it, at least at the intermediate stages between, say, a proto-lemur and a person. Similarly a lot of what allows us to be truly dominant over the planet is relatively recent. In a world without easily accessible coal deposits, or more difficult to domesticate animals, or any of a number of other things our population would be a lot smaller and less technologically advanced, and we probably would still be fighting bears and mammoths for rule over Earth. Note that dinosaurs ruled the earth for 165 million years, and as far as we know, there wasn't a one of them that had human like intelligence. And if they did, they certainly never ended up with a recognizable, technology driven society. \n\nAlso, the particular path many think led to the development of human intelligence would also be difficult to replicate in the sea. Language was a big driver of the development of our brains, and that's hard to get. We also split off from true sea creatures (like fish, rather than dolphins and other sea mammals) very early, so the structure of the brain is very, very different. Squid and Octopi are very intelligent, but their basic brain structure is distributed, and may not be capable of becoming \"human-like.\" That's not to say they couldn't be smart, or better at some kinds of \"thinking\" just that it would be very alien and might not lead to the kind of society that has allowed homo sapien to extend a technological and social dominion over the planet. ",
"Evolution doesn't have a specific goal.\n\nIt isn't like \"Human Level Intelligence\" is the goal that everything is working towards.\n\nEverything adapts in such a way as to be specialized for the environment in which it lives; those which are better adapted to the environment tend to live, while those which are less adapted tend to die.\n\nHumans became so intelligent because of a couple of specific mutations in specific genes; one of the big ones was in a gene that codes for our jaw strength, oddly enough.\n\nThat gene ALSO codes for brain size; so as our jaws grew weaker, our brains grew larger and more complex, and the increased intelligence gave a greater adaptability to our environment than the reduced jaw size removed.",
"you mean dolphins?",
"To thrive and survive in that environment has and does something different than it does topside. I guess you would call it incidental but our evolutionary process required a lot of tactile desterity which brought us to a point where we became tool users, which ultimately led us to where we are now. Such is not the case in the ocean environment.",
"Traits are not evolved just through time, they are evolved because they make the organism life significantly longer. \n\nThe most likely reason for man's evolution, beside just dumb luck, is that surface life is more complex due to more rapidly changing environmental factors and higher availability of resources. \n\nOne of the best ways to spur evolution is by killing off mass amounts of creatures including the organism you want to evolve and/or it's competitors. \n\nThe easiest way to think about evolution is in terms of bacteria. If we wanted to force bacteria to evolve how could we do it? We could overuse antibiotics, killing off bacteria and creating a strong stimulus for natural selection to favor a mutation. We could change the environment which impacts untold amounts of variables, particularly increasing heat or fuels (like animal waste) for bacteria to breed.\n\nThe oceans are so large and don't really have weather and seasons like the surface of the earth. That makes them more resistant to rapid change. As a consequence most marine life cannot take rapid change nearly as well as surface life. The average lifespan of a dolphin is an amazing 40-50 years, while the average lifespan of primitive man is estimated to be about 23. Life on the surface is harder for most creatures and that leads to a faster life cycle and better chances of evolving since evolution only happens via reproduction. This is again by bacteria or things like fruit flies are great ways to study evolution.\n\nEvents like the meteor strike that killed off a huge percentage of life on the planet are huge catalysts for evolution but they tend to impact the surface animals more rapidly. Things like changing seasons are also constant motivators of evolution since they provide a rather consistent challenge to life.\n\nIf organisms have few challenges they will not evolve as quickly because mutations will not increase their lifespans as significantly, thus instead of a new mutation sweeping over the population due to it being an overwhelming advantage, the mutation will not spread as rapidly and could even die off due to lack of being passed on enough. \n\nEvolution and intelligence really don't have all that much to do with time. Life existed on earth for billions of years and anything resembling man has only existed for a few million.\n\nSo, the main lesson here is to not associate time with the development of intelligence. Intelligence is most likely developed by some really lucky mutations and environmental conditions that lead to the rapid adoption of those genetics into the species, thus ensuring that train takes hold as a new feature of the species. \n\nSo the real question is.. what the hell happened to primates a couple million years ago that so rapidly led to humanity. ",
"Because evolution doesn't give a crap about what we think is better or worse :D\nA cave dwelling fish is doing pretty well by having no eyes.\nWhat I mean is, evolution is not about getting better, bigger, stronger, it's just about survival... (actually its more about sex).",
"Since inate \"intelligence\" isn't really quantifiable, who is to say there are not similarly elevated levels, even though they can't be observed by human standards? After all, fossilized evidence of examples of man's intelligence didn't come to be until after we'd evolved, not a bigger brain, but opposable thumbs.",
"I know this is a highly debated subject, but the consensus seems to be that cuttlefish octopuses etc are intelligent.\n\n_URL_1_\n\nAnd that's not even taking aquatic mammals into account.\n\n_URL_0_"
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Tool_use_by_animals",
"http://en.wikipedia.org/wiki/Cephalopod_intelligence"
]
] |
|
2p1ehn | why do some people hear noises prior to falling asleep. | This happens to me and I found out it happens to others too, I just can't find why. It doesn't happen right before falling asleep, but I use it as an indicator that lets me know I'll be asleep soon. The sounds range from random noises to voices, but they go away when I focus on them.
Edit: I realized I didn't put a question mark at the end of the actual question. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2p1ehn/eli5_why_do_some_people_hear_noises_prior_to/ | {
"a_id": [
"cmsg3tu",
"cmsgajy",
"cmsgcym"
],
"score": [
2,
4,
3
],
"text": [
"As I am falling asleep I usually loose my hearing and the realization of silence startles me and then two seconds later I am asleep.",
"It could be [hypnagogia](_URL_0_)\n\nAs you fall asleep, there's a brief period where you're effectively half-awake. Similar to being in an altered state from sedative medication, your brain can't handle its shit, so you hallucinate.",
"They sound like what are known as [Hypnagogic hallucinations](_URL_0_). \n\n > Hypnagogic sounds vary in intensity from faint impressions to loud noises, such as crashes and bangs (exploding head syndrome). People may imagine their own name called, crumpling bags, white noise, or a doorbell ringing. Snatches of imagined speech are common. While typically nonsensical and fragmented, these speech events can occasionally strike the individual as apt comments on — or summations of — their thoughts at the time. They often contain word play, neologisms and made-up names. Hypnagogic speech may manifest as the subject's own \"inner voice\", or as the voices of others: familiar people or strangers. More rarely, poetry or music is heard.\n\nDoes that description fit your experiences? \n\nEssentially, your brain is partially in a sleeping state, and partially in a waking state, causing dream-like experiences while you are half-asleep. They can be visual, or as in your case, auditory. These are quite common and are nothing to worry about. They can also occur when you are waking up, which would be called hypnopompic hallucinations."
]
} | [] | [] | [
[],
[
"http://en.wikipedia.org/wiki/Hypnagogia"
],
[
"http://en.wikipedia.org/wiki/Hypnagogia#Sounds"
]
] |
|
307u31 | how am i supposed to analyze the double toilet flusher buttons? | As someone that has been flushing successfully for several decades, the new flush buttons confuse me.
Almost all new toilets have two buttons to flush the toilet. One is typically larger than the other. Is the larger one made that way to indicate it gives a larger flush? Or is it larger because it is supposed to draw my eye and flush-finger to it, thereby creating a smaller flush?
Whichever it is, I can't tell. I usually have to flush at least twice anyway. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/307u31/eli5_how_am_i_supposed_to_analyze_the_double/ | {
"a_id": [
"cppxj8f",
"cppzfqf"
],
"score": [
2,
9
],
"text": [
"You don't have to analyze it, you can just take a few moments to Google \"[toilet button flush](_URL_1_).\"\n\nYou don't even have to search through the results, just select image results, and you'll get results like [this](_URL_0_) or [this](_URL_2_) that show labels indicating the large button is a full flush, and the small button is a half-flush.",
"ELI5:\n\nYou make peepee = press small button\n\nYou make poopoo = press big button"
]
} | [] | [] | [
[
"http://www.kudzu.com/blogs/hot-off-the-vine/wp-content/uploads/2011/01/dual-flush-toilet11.jpg",
"https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=toilet%20button%20flush",
"http://images.oyster.com/articles/661-2010-01-marriott-dual-flush-toilet.jpg"
],
[]
] |
|
1jotka | how are the child/baby pictures of grown up actors in movies made? | Are they actual child/baby pictures of the actor/actress or of a look-alike or photoshoped or....? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1jotka/eli5how_are_the_childbaby_pictures_of_grown_up/ | {
"a_id": [
"cbgsuwn",
"cbgsx9d"
],
"score": [
2,
3
],
"text": [
"All of the above. Whatever works, works. ",
"All of the above and make-up. Sometimes with hilarious results. \n\nIn Star Trek, they've shown how Wesley Crusher would look at 25. [Here's](_URL_0_) how he would look like and [here's a picture of him then/now](_URL_1_)"
]
} | [] | [] | [
[],
[
"http://en.memory-alpha.org/wiki/Wesley_Crusher?file=Wesley_Crusher%252C_age_25.jpg",
"http://en.memory-alpha.org/wiki/Wil_Wheaton"
]
] |
|
3jkz68 | source of streaming videos | When a TV show or movie is given permission to be streamed over an online service like Netflix, Hulu, Amazon Prime, etc., how is it uploaded to the site?
I'm sure with some of the newer TV shows/movies (~2010), they already have digital copies ready to go but what about older movies and shows? Are they burned from a DVD or video tape or other medium? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3jkz68/eli5_source_of_streaming_videos/ | {
"a_id": [
"cuq5ii3"
],
"score": [
2
],
"text": [
"Most all movies are cataloged digitally. For older vcr and film movies they use special converters"
]
} | [] | [] | [
[]
] |
|
9lefh4 | why do some restaurants add an automatic gratuity for groups of a certain size even if the patrons ask for separate bills? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9lefh4/eli5_why_do_some_restaurants_add_an_automatic/ | {
"a_id": [
"e760oaw",
"e760xq5",
"e760zwc",
"e7612h6",
"e762kaq",
"e768z00"
],
"score": [
8,
5,
2,
4,
3,
3
],
"text": [
"Because not everybody tips, simple as that. Make sure a tax is added so now everybody has “to tip” and no one is tipping more than the other. ",
"But you all had the food brought out at the same time, the restaurant had to rearrange seating for your party, also large parties tend to generate a lot of noise and stay longer than a lone diner. If you took up to tables that waite person doesn't get those two tables from their section.... now imagine that that group doesn't tip. ",
"There are a few reasons for it. It takes an additional server or two away from another section or sections which could impact their tips in their section. It is also done to ensure that the additional amount of work the server(s) have to do is being compensated. There are plenty of groups that are 15+ people that will leave no tip at all.\n\nI'm sure there are other reasons and I'll let the people who work as servers explain it better.",
"The automatic gratuity isn't only because it is a large bill. It is also because of the added difficulty on the staff of having a large table.\n\nThe server has to take orders from more people on a single ticket. The kitchen has to time getting more dishes out at the same time. The bartender has to make more drinks at once than usual. Additional wait staff need to help bring out all the dishes. Having a table of more than 8 people requires a lot more effort than say 5 tables of 2 people.",
"This person just wants an excuse too leave a shit tip. It takes so much work to serve a large party, if everyone left you 1-3$ tips you lost so much money compared to busting out normal sized tables all night because large parties, stay forever, and are a pain in the ass.",
"It's obvious this person has never worked in a restaraunt. Otherwise, he's understand more about the workload. \n\nAlso, the other reason for the automatic gratuity is that when you have larger groups, often times you'll be pushing tables together from different servers sections, taking money out of one servers pocket. This is to compensate that other server for taking their workspace as well as to pay your original server."
]
} | [] | [] | [
[],
[],
[],
[],
[],
[]
] |
||
afchpw | how do wetsuits/diving suits keep your body warm? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/afchpw/eli5_how_do_wetsuitsdiving_suits_keep_your_body/ | {
"a_id": [
"edxfhql"
],
"score": [
6
],
"text": [
"A wet suit traps a pool of water between you and the ocean. Your own body heat warms that water. The thickness of the neoprene insulated that inner layer of water from ocean. \n\nEdit there are also dry suits, which keep you from getting wet in the first place, or mostly keep you dry.\n\n"
]
} | [] | [] | [
[]
] |
||
5q9hr3 | what does a misspelled word or bad grammar look like in chinese? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5q9hr3/eli5what_does_a_misspelled_word_or_bad_grammar/ | {
"a_id": [
"dcxfhp1",
"dcxfrgv",
"dcxh59w",
"dcxif8v",
"dcxj3bf",
"dcxj7na",
"dcxjyu4",
"dcxl2b7",
"dcxl3vj",
"dcxl57z",
"dcxldup",
"dcxle7k",
"dcxlmed",
"dcxmm0n",
"dcxms83",
"dcxom81",
"dcxp9ld",
"dcxpi5b",
"dcxprb4",
"dcxprg4",
"dcxqw6e",
"dcxt91a",
"dcxuc94",
"dcxvcqz",
"dcxvdhl",
"dcxw7f5"
],
"score": [
5001,
496,
39,
18,
6,
195,
8,
31,
19,
13,
4,
2,
43,
3,
10,
3,
2,
16,
12,
3,
2,
2,
2,
2,
2,
3
],
"text": [
"I kind of get what you're asking.\n\nWell, first thing is, you can't \"misspell\" Chinese per se. Maybe you can get the strokes wrong or have missing strokes (Like writing 日 or 由 when you actually wanna write 田), they can be two totally separate characters.\n\nOr, you can just use the wrong character (since Chinese has limited sounds, a lot of words share the same pronunciation, like 鸡蛋 (chicken egg) and 鸡弹 (literally \"chicken bomb\", but just FYI this isn't a thing, just an example) are pronounced exactly the same, but if you wrote the latter the teacher would probably underline it, because that isn't a thing.\n\nGrammar wise, I guess the order of the words matter? Like in English. “Home I am\" is grammatically incorrect, and it's similar in Chinese. ",
"I'm a Singaporean who has been learning (Mandarin) Chinese as my second language from young, so maybe I can help. It's my first time answering a question on ELI5 so I hope my explanation is easy to understand.\n\nYou might know that Chinese uses logograms, which are like pictures instead of stringing letters together to form words as in English. Just as how pictures are drawn using lines, logograms are also formed by drawing lines.\n\nIn English, a misspelled word is one with, well, a wrong spelling, like spelling 'word' as 'ward'. I think you can agree that the letters 'o' and 'a' are both circular and thus may look similar to a person who is unfamiliar with the Latin alphabet, but they are different. Now, take a look at this three Chinese characters. 己 已 巳。They all look the same, yes? But they are really different--you can see that the vertical line on the left does not protrude out of the middle horizontal line which leaves some sort of gap or cave, or it's only drawn halfway, or it's drawn fully which closes up the gap or cave. The first character has the meaning of 'self', the second of 'already', and the third of 'snake' or '9am to 11am'. They look the same, but their meanings are vastly different. \"My friend is in hospital word one.\" Huh???\n\nWith respect to ungrammaticality, Chinese does have grammar (surprise!?). Just as in English where a word order wrong make your sentence nonsensical may, the same thing applies to Chinese. If you were to swap the positions of the first and third characters of the sentence 我吃饭。 to get 饭吃我。, you would have said that \"The rice eats me.\" instead of \"I eat rice.\" A person who speaks a language with an Object-Verb-Subject sentence structure may find it hard to get used to the Subject-Verb-Object sentence structure in Chinese, and may potentially use words in the wrong word order which leads to ungrammaticality.",
"People have mentioned the writing aspect, but no one has really commented on the grammar part of the question. I don't speak any Chinese language, but I know a fair share of linguistics.\n\nSo, every language has a system of grammar that allows you to say stuff by putting words in some framework. There are lots of things going on there that one might not immediately consider part of grammar - not only does grammar dictate what shape words take on (morphology) but also how they're arranged (syntax). Chinese is known for having very little morphology (or at least morphology as is understood from a european context) but it most certainly has syntax rules that you can break.\n\nBut to make an example governed by morphology: in east asian languages there is a thing where usually all or most nouns behave somewhat like english mass words (e.g. you can't say \"three breads\" in english, you have \"three loaves of bread\"). Using the wrong counting words would then be bad grammar.\n\nAlso there's apparently some 700 page tome on mandarin grammar. Languages are complicated once you look at the details.",
"Reminds me of when I was in school - Back in the late 90s a lot of people came to the UK from Hong Kong because of the Handover back to China, so we had a few Chinese people join us in our school. \nEnded up being good mates with one of them, and I was trying to copy a phrase he had written (Probably happy birthday or something). He laughed at my attempt, and his sister corrected it saying that my attempt was based on my friends terrible handwriting which made it nigh-on unreadable! \n\nSo, I know for sure that bad handwriting is a thing!",
"Not fluent, but i did study chinese in china. Since chinese uses symbols, while some words sound similar, you're more likely to use a wrong word (like the cake vs egg bomb example here), or use the wrong root word (讲 vs 进），than an extra stroke. But do consider i was learning chinese as a second language, not as first so it may be different. \n\nConversations tho, i learned the trick is to just say it really fast, so the wrong accents are less emphasized :)) \n",
"Chinese American here. My only example of \"typo\" was when I was in china trying to speak to locals for help. I was in Starbucks desperately trying to use their wifi but I didn't have a Chinese number to receive the pin. I went up to a girl and kicked it off with \"Excuse me, I don't have a Chinese cellphone\". Little did I know, instead of saying \"手机” which means cellphone, I said \"小鸡”. Both sound very similar to a non-native speaker. The literal translation is \"Small chicken\" but the slang means \"Small Cock\". So I went up to a random girl in China and said I didn't have a Chinese small dick. Her face went from concerned to humor when she saw I was waving my iPhone (without a SIM card) in my hand.\n\nEdit: Fixed less to small (少 - > 小) I used the pinyin shao instead of Xiao by mistake",
"I'm not sure about Chinese, but with in Japanese (which uses Chinese characters extensively, known as kanji), there's a phrase called \"henkanmisu\" (変換ミス). This refers to the type of typographical error when you select the wrong kanji when word-processing.\n\nYou type Japanese phonetically, so to type 変換ミス I type 'hen kan mi su'. The Input Method Editor which converts this into Japanese pops up a little window showing the possible kanji used in the phrase 変換ミス.\n\nNow for that phrase the IME I'm using shows only one possibility. but if I were to type 'ha', the IME shows possibilities such as 葉 歯 派 and a few others, since there's a lot of kanji that can be pronounced 'ha'.\n\nSo an example of a henkanmisu would be I want to type teeth (歯) but I misclick or hit space too often (which cycles through the options) and woops! I've typed leaf (葉) instead.\n\nNote that this only applies to typing.",
"Chinese here. One thing that people actually do and is wrong grammatically is speaking an incomplete sentence. When a sentence is really long, sometimes it would miss crucial elements, like objective or subjective. sometimes it is very difficult to tell that if a sentence consist of two or three sentences. I remember doing a lot of those questions in the Chinese equivalent of SAT/ACT but I can't really think of an example right now.\n\nmost \"typos\" would consist of using a character of the same pronounciation but different writing. It is somewhat easy to tell, unless it involves some less used characters.\n\nthe most common type of mistakes is the misuse of idioms. Unlike English idioms, Chinese idioms are usually based on some ancient text and consist of 4 characters. For example, \"空穴来风\"/empty cave causes wind means a rumor is not unreasonable. but some people think it just means the rumor is unsubstantiated, and they'll use it wrong. there are hundreds of idioms like that, and some have even changed meanings during the years. This is by far the most common \"typo\" or grammatical mistakes in Chinese imo. ",
"I'll give you an example! This is some of my graded Chinese work:\n\n_URL_0_\n\nI'm a Mandarin student in college, I've studied it for four years now. In Chinese it can be hard to figure out how to phrase things and how to order phrases within a sentence. I recently started the spring semester at my college and our first assignment was to write about our winter breaks. I visited my brother in Singapore.\n\nShe highlighted the poorly written sentences, numbered them, and rewrote them below. I'll do a literal translation of the first one:\n\nI wrote: 去年九月，我哥哥和他家人（老婆，两个孩子\u0005）都去了新加坡。我哥哥工作的公司给他们这个机会\nTranslated as literally as possible: Last year in September, my older brother and his family members (wife, two kids) all went to Singapore. My brother's working at company gave them this opportunity. \n\nShe corrected it to: 去年九月，我哥哥因为工作的关系和家人一起搬去新加坡。我哥哥和我嫂子有两个孩子。\nTranslated as literally as possible: Last year in September, my older brother because of his work connection, with family members together go to Singapore. My brother and my sister in law have two kids. \n\nI think they way I wrote \"我哥哥工作的公司\" (my brother's working at company) didn't sound so good. \n\nAlso, see at the bottom the one character in red, I meant to write 南 (nán south) but instead I wrote 男 (nán male)\nIn Chinese, the common way of typing is by using Latin characters to spell the sound of the Chinese character, and then the computer guesses which character among the many homophones you're trying to write. Looks like this _URL_1_\n\nFor the most part, we aren't taught that many grammar structure rules, we just kinda get a feel for them. When I ask my Chinese friends why a certain sentence doesn't work, they usually just say something like \"it doesn't sound right\". \n\nOne thing we are taught about sentence structure though, is that you should start with time then subject. Don't say \"I yesterday went,\" say \"yesterday I went\"\n\nInteresting tidbit, before the early 1900's written Chinese and spoken Chinese were kind of like different languages with different grammar rules. The revolutionaries in China who wanted to modernize the country pushed for people to write how they speak. So I guess in that sense, written Chinese is relatively new. Maybe I'm missing part of the story though, this is just from reading wikipedia articles.\n\nTl;dr word order, make it sound right",
"Native Chinese speaker here. Recently people in BBS argue about the usage of \"remake\" because they use this word in a meme (_URL_0_). Grammar Nazi insists the word \"重制\" is preferred, while many argue that \"重置\" is also correct, although these two spell the same and have similar meaning.",
"Chinese characters are made by mashing up [these 200 radicals next to each other.](_URL_0_)\n\nIt's possible to \"misspell\" words by writing the wrong radical for part of the character, for example writing **肢** instead of **肤**.\n\nIt's like if I wrote 'he undercat my prices'. You probably know that I meant 'undercut'.",
"I've been learning Chinese for a few years, and I've found so far that when I'm writing characters, I have a tendency to accidentally omit half the character. Most more complex characters are made up of simpler components, called radicals; for example, the character 课 means (academic) class, and is made up of the radical for \"speech\", ⻈, and the character 果, meaning fruit (often times the relationship is more clear, either by meaning or pronunciation, but there are no consistent rules). When you're writing quickly, it's easy to either omit the ⻈ radical or replace it with a similar looking one, like ⻠.\n\nedit: clarity",
"In Chinese, we have what we called [measure words.](_URL_0_) \n > \"Unlike English and most European languages, Chinese does not distinguish between singular and plural, so nouns are simply abstract in number, with context determining whether something is singular or plural. \nBut when you have to specify a certain number of something, you combine the number itself with a measure word, followed by the noun.\"\n\nIn English, you ask \"How many people?\" In Chinese, it would be 几个人 (jĭ gè rén)? \n\n几 is how many and 人 is person/people while 个 is the measure word for people. A lot of people who are learning Chinese for the first time tend to omit measure words.\n***\nAlso another common mistake would be the usage of number 2: 二 (èr) and 两 (liǎng). Using the previous example, if I was to answer \"Two people,\" 二个人 would be incorrect. The correct answer would be 两个人.\n\n二 (èr), is when you want to refer to the digit, for example when you are count from 1 to 10 or when you are telling someone your phone number.\n\n两 (liǎng) is used when quantity is involved. Like the example I showed above, two people- 两个人.",
"There's that show, 中國漢字聽寫大會, which is a bit like a spelling bee. Chinese students are told phrases or words and have to write them. \n\nBut it's like way way harder, like most of the adult audience often don't know the answer either, and they have scholars to explain why this is write or wrong. And sometimes the judges don't agree on whether the studwnt wrote correctly or not.",
"There is a word for spell in Chinese, but it would only be for pinyin or a foreign language that has an alphabet. Any paper written in Chinese above a very young age will be all in characters, not pinyin. I would say that the equivalent of a misspelling in Chinese is using the wrong character, either because of mishearing or simply not being familiar with the correct character to use.\n\nAn example of mishearing in English would be \"lacksadaisical\", because it's similar to \"lax\", which has a similar meaning. \"All intensive purposes\" is another. This can happen in Chinese, too, as some characters have a certain meaning by themselves and sort of make sense if you mishear the word or idiom.\n\n\"Misspellings\" on on a computer or phone are quite easy. Imagine autocorrect is always on -- you type a long sentence in pinyin and the autocorrect figures out exactly which characters you probably want. If you don't proofread, you can have some big mistakes. For example, \"nine o'clock\" and \"hotel\" have the same spelling in pinyin, so it's possible the autocorrect thinks you want to write \"I hotel arrived\" rather than \"I nine o'clock arrived.\"\n\nAnother \"misspelling\" would be a word that people say often but don't write, especially if the character is highly complex. The best example is that 90% Chinese people cannot write the last character of the word for sneeze (打喷嚏). In this case, using a computer or phone actually solves the problem.\n\nFor grammar mistakes, keep in mind that all languages have grammar patterns or certain words that always go with certain words. \"Be familiar to\" would be wrong in English, as would choosing the wrong preposition in Chinese after the word for familiar.\n\nStudents spend a lot of time learning Chinese characters and grammar, so I'm guessing they have fewer grammar mistakes than an English speaker would. One reason is that they spend less time on other concepts. Punctuation in Chinese is easier than in English. For example, comma splices are OK, you can just put two clauses or sentences together with a comma, like I just did. Chinese students also spend a lot less time on the organization and logical flow of the papers they write.\n\nEDIT: Spelling, of course.",
"Well, there are a few different cups of tea here:\n \n1.Misspellings happen two ways, depending on whether you're using a keyboard or handwriting: \n\nTypos (when you type the wrong key on the keyboard) will lead to completely different words coming out, which often makes the entire sentence illegible. You learn the be extra careful, since it's really hard to notice when you make one, but it changes the meaning so much for the reader; there is no such thing as a light misspelling in Chinese. You can also make typos by using the wrong hanzi because it has the same pronounciation, but that is easier for the reader to guess.\n\nHandwriting: This one is easy to do, you either get the wrong stroke in the right ideogram, or you get the wrong ideogram. 99% of the time it is so close that the reader can guess what you initially wanted to say, with few exceptions. If it's the wrong stroke, it's close enough to the hanzi to guess where it went wrong, if it's the wrong ideogram then you might notice it because it is pronounced the same (that's usually where people make mistakes). \n\n2.Grammar:\nUnless it's your L2, basically the only way to get grammar wrong is to use the wrong particle, or wrong word order, or to do that thing where you start a sentence, trail off and go into the other without finishing the first. Similar to grammar mistakes in English, the comprehensibility is dependent on how big the mistake is. ",
"Well, most other replies have offered good answers, but I have a related remark. Chinese youngsters use a sort of leet-speak on messaging services, where they replace characters with similar-sounding characters with different meanings. Where 外国人 means foreigner, 歪果仁 means crooked-fruit-benevolence, but is pronounced the same. It's kind of like leet-speak or polan-ball-speak where knowingly making grammar errors in the right way is part of the culture.",
"I've seen enough people complaining about others don't use 地的得 correctly, I believe it's the equivalent of complaining about your/you're, would of/would've.",
"Chinese here. \n\nAn example of a misspelled word:\n\n自由 < -- > 目田\n\nLiberty < -- > eye field (not a word)\n\nAn example of bad grammar: (from an interview of former Australian prime minister Kevin Rudd)\n\nwrong:\n\n我参加学校\n\nI partook school.\n\ncorrect:\n\n我去上学\n\nI went to school / attended school.\n\nAnother example of bad grammar in terms of omitting some essential words denoting the tense of the sentence (tense in Chinese is implicit):\n\nwrong:\n\n你看最新的星球大战电影？ Do you see the latest Star Wars movie?\n\n我看。 I see.\n\ncorrect:\n\n你看过最新的星球大战电影了吗？ Did you see the latest Star Wars movie?\n\n我看过了。 I did.",
"Is there a version of Google or Baidu that shows corrections?:\n\n草泥马 (Cǎo Ní Mǎ)\n\n#Did you mean? ***肏你妈 (Cào Nǐ Mā)***\n\n",
"well ,firstly it gonna depend on if you writing out useing hand writing ,or does you typing out using key board at computer ?\n\nIf you hand write ,some time you can forget how to write some character .We have some idiom express that ,it say \"LIFT PEN ,FORGET CHARACTER .\"In such situations, usually you not even can remember first stroke write out that character .This happening if maybe you wanna write out some seldom use character ,such as 礋，maybe you can remember there some rock at left side ,but you forget about other side .\n\nOther time ,you perhaps write out some part the character ,but in fact it wrong .Now you have write some character not exist ,but it`s funny because maybe whomever read that just read some context ,think it correct !!\n\nUse the computer ,sometime I type out some PIN YIN ,after I select what character it suppose become ,but I mistakenly select wrong one .Now I just to look like the noob ,because maybe that character very very wrong !For example ,instead 的，i type 得！this not only the typographical style error ,but also the gramma error !",
"Have seen some answers, I have my owe point.\nChinese is quite different from English, Chinese letters develops in six shapes: 象形（picgraphs）,指事（self-explanatory characters）会意（understanding word）,形声（phonogram）,转注（focus words）,假借（phonetic loan character）, Chinese articles have ancient and vernacular style, in case of meet the poem format, a long sentence meaning always simplified into a few words, e.g. 桃之夭夭，灼灼其华 （from Book of Songs）, 桃，桃花（peach blossom ）夭夭,花草树木生长繁盛（plants grow luxuriantly），灼灼，色彩鲜艳（vivid color）, 华，同花 （flowers）,means flowers are in full bloom, beautiful in colors red in fire.\nGrammars are changeable and complicated, just like English. But learning Chinese needs two steps, Pinyin and Kanji, misspelled pinyin is similar with English, that of kanzi always in shapes, just like 日（sun） and 曰（says）; 己（自己，self） 已（已经 already） 巳（巳时 from 9:00am from 11:00am）;晴（sunny day）睛（eyes）...\nSome have different pronouciation, which is polyphone, some have different meanings which is polysemic character. There is a very interesting character \"|\"，is a polyphone polysemic letter, 1. pronouces and means like “竖”, a vertical line, also like “竖”；2.pronouces and means like “一”, one or number one; 3. if writing from top to bottom, pronouces like “衮”，means “up and down connected”; if writing from bottom to top, pronouces like “退”，is put in the opposite meaning with “衮”. ",
"You usually run into homonyms:\n\nWhen you see 大斧 which means big axe and say 大爹 which means big daddy, you get vastly different meanings.\n\nLike 宇 and 字 they look very much the same but one means universe and the other character (not part a movie but characters on a keyboard).\n\nOr 电 vs 龟，one means electricity and the latter turtle.\n\nSometimes people save time and just type quickly in Chinese, so you end up with:\n\n偶断死连 （oh do-un ss li-an) - meaning literally, partner breaks and death connected.\nWhile you actually phrase is:\n藕断丝连 ( oh do-un ss li-an) - a phrase that means when you break a lotus root, the strings are still connected. Often used to describe lovers that are physically separated but are still romantically connected. Chinese long-distance relationships basically.\n\nSo same pronounciation, really different meanings.\n\nMuch of Chinese humor can be traced on word-play like this.",
"There's lots of ways to mess up Chinese!!!\n\n**1：Pronunciation** \nThis is admittedly much more of a problem for second language speakers, but even Chinese people misunderstand each other. A new little piece of vernacular came around from a sad man recently. He was distraught and crying, so his speech wasn't clear. I'm going to write the vague pronunciation of the Chinese instead of pinyin or real characters: he said, \"nan show shiang koo,\" but many people heard \"lan shou shaing goo.\" Instead of saying \"I'm feeling shitty and wanna cry\" he said \"blue skinny mushrooms.\" Now that's become vernacular for feeling shitty and wanting to cry. \n\n**2: Misprinting words** \nThis is sometimes deliberate：这样子 can become 酱紫 because the sound is very similar. \nSometimes it's accidental, though: Most Chinese speakers (because of how Chinese keyboards type) have entered completely wrong characters into a text message, because the keystrokes are similar. For example: using a cellphone 那么不给 & 忙不给 would be written using the exact same keystrokes; however, the second variation is just wrong. Most fluent speakers recognize many common errors like this and can correct should these typos occur while reading, though. \nSometimes other accidental, too: I recently wrote a short paragraph about going to the park (公园) and I absent-mindedly kept writing 工园. The first characters sound similar, so the reader knew exactly what I meant and corrected it. Small errors like this can definitely make non-native speakers stand out like sore thumbs though! \nThere's still a whole bunch of other possible mistakes. Surely you can imagine getting any of these mixed up 我哦饿 or 头买卖实读 or 农/衣( < - yes, those two are different in meaning, writing, AND pronunciation). There's two types of errors normally Chinese error and Foreigner error. A Chinese won't confuse 农 and 衣, but when you do they'll say \"no, they're different! Gosh, you're so silly.\" When a Chinese makes an error they tend to matter-of-factly correctly one another then just move on (however, most of the time minor typos aren't even acknowledged).\n\n**3. Grammar** \nI'll give two examples, cause this has already turned into a bit of a clusterfuck (sorry). First， 刚 and 刚才 can both be tacked to the beginning of a sentence to talk about things that have \"just\" happened. Grammatically (because all sentences need verbs) 刚才 would have a verb, and that verb needs be be followed by 了. Although identical in meaning, 刚verb了 is *incorrect*. No 才, then no 了. I've NEVER been corrected on this though! I've asked people if it sounds weird after self-correcting. Some people say it did sound weird. Others claimed not to notice and went on to say there pretty much the same. Second, 的，得，and 地 are all pronounced the same, but their usages vary. In non professional Chinese people rarely write the the second and third form--opting instead to make the first version universally acceptable. \n\nA huge number of Chinese people not only don't care about grammar, but just don't understand it! It's not to say that people aren't intelligent either, but Chinese is a low-context language. Although conventional models of English tend to show that speaker and listeners bear similar responsibility for the clarity of meaning during conversation, Chinese tends to put a lot of responsibility on the listeners ability to comprehend the speakers meaning (less so on the speaker to speak clearly). It's very common for Chinese people to ask for clarification or to repeat and paraphrase an idea before a conversation is over to verify everybody has understood each other. NOT doing this FREQUENTLY leads to LOTS OF FUCKING HEADACHES. \n\nAnyway, it's 2am. I'm sleepy and this has rambled on much longer than I expected. I'll try to remember to proof-read in the morning for clarity should anybody be reading it. \n\nEDIT: OH! One more thing about grammar. In it's most simple, Chinese tends to follow the Subject + Verb + Object sentence pattern. Time and place of an idea/event go either before or after the subject. \n > > I * This morning * 10 o'clock * Go eat \n > > I * 10 o'clock * This morning * Go eat \n\n Here the second sentence's word order is wrong (grammatically speaking). It could be comprehended, but you might see the listeners eyes narrow just slightly as this will sound unnatural. Obviously the larger the grammatical error (or if there are many) the meaning will be harder and harder to discern. Just like in English the grammatical errors that sound **just bad** are not typically from native speakers. It would be like an English speaker forgetting their articles ('a's and 'the's) in a sentence.... it would just sound fucking weird and we wouldn't forget. \n\nAnyway! Original question: ELI5:What does a misspelled word or bad grammar look like in Chinese? \nCorrect: 我看懂了这本书 \nIncorrect: 我把这本书看得懂 \n\nHope this helps some. ",
"-Insert typing-on-mobile disclaimer- (Also typing this after a full bottle of wine.)\n\nSo, I'm a half-Chinese (and half-Malay) (or just full Asian with Chinese blood for those who can't tell the difference) dude from Singapore (Google it). Chinese is my third language (English: first; Malay: second), so I'm not amazingly fluent in it, but if sent to rural China, I'd be fine.\n\nAnyway, in English, and other languages that use different phonetic blocks to make a word, a misspelled word means using the wrong letter/character. E.g., 'weird' becomes 'wierd' (common spelling mistake), or 'hello' becomes 'helo' (typo/ spelling mistake). In Chinese, technically, misspelling words isn't really the same as how you normlly define misspelling.\n\nA \"misspelled\" word in Chinese can be something like a character missing a stroke/a few strokes. E.g.,咖 (ka1) vs 加 (jia1). 咖啡 means coffee (ka1 fei1; probably from the French café, but don't quote me on this), vs 加啡 (jia1 fei1), which doesn't mean anything (I think). If you miss out the extra initial 口, it's wrong, but people can generlly figure out what you were trying to say if they have some context.\n\nAnother example is using a completely wrong character that looks similar. E.g. 天 vs 夫. They look similar-ish, but have completely basis. Not an exact comparison, but think of it as being confused between 'b' and 'd'. They look similar (mirror image-ish) but are completely different in their function.\n\n(For the first example we can use 'i' vs 'j' or 'l'. The difference between 'i' and 'j' is a missing curve; 'i' and 'l' is a missing dot.)\n\nIn terms of grammar, the mistakes made are similar, i.e. word order, tenses, etc.\n\nApologies if anything I've said is wrong (I don't think so). But if someone could explain it clearer/ add on/ clarify, that would be good!\n\n(Please remember the bottle of wine in my bloodstream before bashing me. > . < )",
"Great detailed answers already posted. But I feel like I should add to the grammatical aspect by mentioning how obscure counter words can get. \n\nIn English we say \"a pair of pants\", a \"school of fish\" etc, but we don't have a counter word for maybe, \"an apple\" or \"a fish\". Well, in Chinese they have a counter word for everything, even when singular. And sometimes they can be used wrong by both learners and native speakers.\n\nFor example, counter for chopsticks: 一根筷子 (right) vs 一条筷子/一个筷子 (wrong). More obscure ones exist too, like how in English it's \"correct form\" to say a \"murder of crows.\" Like, not many people know the counter for 布料(cloth) is 一匹(same counter word for horses for some reason). And more, there are ambiguous ones too... like for example \"a murder case\" would be 一起谋杀案，but 一宗谋杀案 is also correct."
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://drive.google.com/file/d/0B2-o7YKqF-DELUw2Y1U4RXNrTUk/view?usp=drivesdk",
"https://d2mllj54g854r4.cloudfront.net/images/type_chinese/win8/usage2.png"
],
[
"http://news.mydrivers.com/1/471/471490.htm"
],
[
"http://i.imgur.com/eEaQzI1.jpg"
],
[],
[
"http://www.languagerealm.com/chinese/chinese_measure_words.php"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
||
260pdc | web 3.0? | I saw something about Web 2.0 just now (I know what Web 1.0 and 2.0 are, you don't need to explain that to me) and it got me wondering about a Web 3.0. What would actually change? Moving from 1.0 to 2.0 we changed from static to interactive, so what's next? A couple of sites I found gave examples of asking complex questions and receiving answers (eg, I want to go out for dinner then see a movie, what are my options?) but the way I see it all that does is give us more in depth ways to search the internet rather than changing anything about the actual webpages. Plus, we're already seeing that sort of stuff with Siri and the like.
Sorry for the wall of text, I've had a lot of caffeine and sugar tonight. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/260pdc/eli5_web_30/ | {
"a_id": [
"chmiz78"
],
"score": [
2
],
"text": [
"Web 2.0 was just a catchphrase that some journalist came up with. It's just a vague, handwavey term that can be used to talk about whatever a speaker wants. Nobody spoke of \"Web 1.0\" prior to it becoming widely used.\n\nI hope we can avoid using \"Web 3.0\" in the future. The people that are actually creating and innovating won't be using it, just the guys on the sidelines and the copycats."
]
} | [] | [] | [
[]
] |
|
9is0p4 | why does mostly the top of our feet hurt when our feet land on something hard? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9is0p4/eli5_why_does_mostly_the_top_of_our_feet_hurt/ | {
"a_id": [
"e6lwllt"
],
"score": [
3
],
"text": [
"If you look at a human skeleton, you will see that there are long bones at the top of our feet. Those are called metatarsal bones. The force of the impact of landing hard on your feet will travel through those bones, which is painful."
]
} | [] | [] | [
[]
] |
||
28b01y | what's the difference between the different types of anti-aliasing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/28b01y/eli5_whats_the_difference_between_the_different/ | {
"a_id": [
"ci9ogiv"
],
"score": [
5
],
"text": [
"There's different methods involved to get rid of the jaggies with varying levels of effectiveness and performance penalties.\n\nThe most brute force one being super sampling. The image is rendered much higher than the target resolution and then shrunk down to the target resolution. This is very effective at getting rid of jaggies but is has an extreme performance penalty because you are rendering the scene at really high resolution just to shrink it down.\n\nMSAA is a simpler version of super sampling that only performs that high resolution render at certain sample points. When you see 4xMSAA that means there are 4 sample points 8x = 8 sample points and so forth. Its's a lot more feasible in terms of performance penalty when it comes to realtime graphics while still producing a nice result.\n\nFXAA is AA that uses a screen space edge detection algorithm to find jaggies and blur them. Basically It's a shader(gpu program) that can find where the edges of 3d objects are and then it can apply ablur to them to reduce the appearance of jags. Of the 3 im mentioning this has the lowest performance penalty but also produces the worst result with the final image often looking fuzzy because of the blurring.\n\nOf course there's a plethora more of techniques but hopefully you get the gist of it."
]
} | [] | [] | [
[]
] |
||
5ha6ew | what do people mean when they say that all birds are dinosaurs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ha6ew/eli5_what_do_people_mean_when_they_say_that_all/ | {
"a_id": [
"daylix8",
"dayljnk",
"dayljqv",
"daylob2",
"daynmsv",
"dayplus"
],
"score": [
2,
6,
3,
5,
5,
3
],
"text": [
"Dinosaurs most likely evolved into modern day birds. As an attempt to evade the auto mod I will explain why we think that. It mainly comes down to the large amount of physical similarities that the two share. We are also able to form a almost complete timeline between the two species utilizing fossils. ",
"65 million years ago a comet wiped out all the dinosaurs on earth.\n\nWell, almost all of them.\n\nA small group of feathered dinosaurs survived, and eventually evolved into all the birds of today.",
"If you were to trace a bird's family tree back far enough, you'd find an ancestor that was a dinosaur.",
"Birds are said to be evolved from dinosaurs, because they share traits that dinosaurs had, such as hollow bones which makes them light enough to fly, which some flying dinosaurs had. Their claws resemble those of velociraptors with the same bone structure. They build nests and hatch from eggs.\n\nThey both had feathers. Their lung are heart structures are similar in how they work. With obviously the dinosaurs lungs being hypothesized in how they worked. We also have genetic proof, from material that was preserved of a Dino and compared to modern birds.",
"**ELI5:** Birds are part of a bigger reptile group, the dinosaurs; just like humans are part of a bigger mammal group, the primates.\n\n---\n\nTo truly understand this statement, is important to explain phylogeny, which is the history and genetic relationships among individuals or groups of organisms.\n\nLet's take for example your family tree. You have a mother and a father. Your mother and father have a mother and a father, your grandparents. Your grandparents have/had a mother and a father, your grand-grandparents. This idea goes on and on and on... If we plot this idea, we get [something like this](_URL_1_).\n\nThe same principle can be used to understand groups of organisms. For examples, humans are \"siblings\" to chimpanzees and bonobos, the group of humans-chimpanzees-bonobos is sibling of gorillas, the group of humans-chimps-bonobos-gorillas is sibling of orangutans, that groups is sibling to gibbons. They all make a group called \"apes\", which includes humans, chimpanzees, bonobos, gorillas and gibbons ([Source](_URL_3_)). Plotting that idea, we get a \"phylogenetic tree\" (shown in source).\n\nApes are siblings with monkeys, that group is sibling with lemurs. That whole group, apes, monkeys and lemurs, makes the greater group of \"[primates](_URL_2_)\".\n\nApplying this very same idea to birds, by comparing the traits and genetic makeup of birds and other related organisms, then plotting the phylogenetic tree, [we get this](_URL_0_). The group \"Archosauria\" is what's commonly known as dinosaurs (although *true* dinosaurs are only those members from the group Dinosauria). As you can see from that image, the groups of birds, is contained within the group Dinosauria, meaning that birds are dinosaurs, just like humans are primates.",
"Dinosaurs were comprised of multiple different types of organisms (orders). One of these orders were Theropods, that contained dinosaurs such as the T-Rex. However, and as evolution took place one of these branches diverged and became smaller with time, eventually being small and light enough to glide, which was a huge advantage in surprising prey. \n\n\nWhen the meteor struck, they were small enough and capable enough hunters to make it through the extinction and eventually evolved into the birds we know today.\n\n\nSource:_URL_0_"
]
} | [] | [] | [
[],
[],
[],
[],
[
"http://www.berkeley.edu/news/media/releases/2005/06/images/revuelto_tree_big.jpg",
"https://image.freepik.com/free-vector/family-tree-icons_23-2147511229.jpg",
"https://en.wikipedia.org/wiki/Primate",
"http://www.nature.com/nrg/journal/v15/n5/fig_tab/nrg3707_F1.html"
],
[
"https://en.wikipedia.org/wiki/Theropoda"
]
] |
||
1z0bkk | why china has both an overcrowding/pollution problem and ghost towns. | I've seen a lot about China's pollution issues recently (and its highly probable link to overpopulation). But I also see random articles on these "ghost" towns where either they've been built in anticipation of people moving in or were abandoned after some market went under. Moving successful businesses (and therefore workers, families, and accommodating businesses) to these Ghost seems like a pretty obvious solution to the aforementioned pollution problem.
However I'm not naive enough to assume this hasn't also occurred to Chinese officials. The situation seems to imply they don't care much for public health. And even if the Chinese government is callous enough to not care about the safety of its citizens, the time/money lost dealing with smog and smog-related production delays (sick days, areas shutting down, etc.) would demand **something** be done.
So basically, why doesn't a government that **could** move virtually any business in the country to these "ghost" towns not do it in an effort to curb such obviously harmful pollution and overcrowding?
There must be some nuance here I don't know or understand.
Edit #1: From comments received already, problems with relocating people include: as little as 10% availability left in some "ghost" towns, lack of vehicular accessibility (including railways), and the speed at which things can be constructed.
Though these are great reasons that a plan would be difficult to form, it still seems that dispersing their population among more cities is the best answer. As of now, I still think "ghost" towns offer a ready-to-go option for people willing to move immediately, thanks to the comments already, I can see it wouldn't be a wholly satisfying solution by itself. Maybe the Chinese government has issued a statement on what their plans for handling overpopulation/pollution is? Or why dispersing the population is not being pursued more forcefully? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1z0bkk/eli5_why_china_has_both_an_overcrowdingpollution/ | {
"a_id": [
"cfpc9k4",
"cfpcpss",
"cfpmif1"
],
"score": [
5,
7,
2
],
"text": [
"The ghost towns are largely a myth.\n\n_URL_0_",
"The non-myth ghost towns are in the middle of nowhere and usually lack essential services. Nobody wants to move to a city with no grocery stores, no running water, and no fire department that's 100 miles from anywhere, no matter how cheap the apartments are.",
"Here is a really great article on what the problem is: _URL_0_\n\nIn short, the problem is structural. It's not that there aren't people willing to fulfill all those vacancies, there most certainly are. \n\nIn china the government owns all the land and rents it out to people. Consequently, most of the local governments income comes from this. Also they want to maximize the profit from the land so tilt development towards higher end housing, as opposed to affordable housing that would suit the majority of the people in china. \n\nThis works, since in China bank accounts are heavily regulated and offer measly returns. The stock market is very volatile, so there are few quality investment choices if you're wealthy. Like in America, people there see housing as a sound investment, and believe the prices can only go up. Their reasoning is further buttressed by the fact that local governments revenue is heavily dependent on property prices, so it's heavily in the local governments interest to ensure prices keep going up. (Rents and housing prices have been increasing, even with all these 'vacancies'). \n\nWhich brings to the next point. It's not so much that these houses are vacant since no one is buying them, people are buying them, it's that they're not buying them to live in, they're buying them as an investment. The people who need housing (far more numerous) can't afford the places that are being bought and built. That's why there are ghost towns and such high vacancy rates in china."
]
} | [] | [] | [
[
"http://blogs.wsj.com/chinarealtime/2013/09/24/chinas-ghost-cities-may-not-be-so-spooky/"
],
[],
[
"http://www.thechinabeat.org/?p=3610"
]
] |
|
3v3r4p | why does rubbing your finger across your lips make them softer? | seriously have no idea, but it works! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3v3r4p/eli5_why_does_rubbing_your_finger_across_your/ | {
"a_id": [
"cxk393o",
"cxk3doy",
"cxk4gp1"
],
"score": [
3,
3,
2
],
"text": [
"Anyone else try rubbing their lips with their finger after reading the title?",
"Your lips require oil or else they get chapped. Your fingers have oil on them, and some of it comes off onto your lips. It's the same concept as chapstick just much less effective.",
"I thought it was because, when you rub your lips, you rub off the top layer of lip skin. And then it's all smooth yet raw underneath? No?"
]
} | [] | [] | [
[],
[],
[]
] |
|
4en0jy | why do video game discs have loading screens but nintendo cartridges don't? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4en0jy/eli5_why_do_video_game_discs_have_loading_screens/ | {
"a_id": [
"d21iblz",
"d21ihxe"
],
"score": [
3,
9
],
"text": [
"Nintendo (or really any) cartridges never take more than a few seconds to load so there is no need for a loading screen.",
"Video game cartridges are like the solid state drives (SSDs) of the past. They had much faster data transfer rates but data capacity is much more expensive since the data is stored on computer chips.\n\nDisks are the opposite and are similar to hard drive disks (HDDs). They have slow transfer rates because they require reading of a physically spinning disk but can hold a large amount of data. This is why there are loading times for games on disk because the console has to read the disk and load it.\n\nIn the N64 vs Sony Playstation days, N64 had very responsive games with little to no loading screens. However, the Playstation could have games with movie cinematics because the CDs could store a large amount of data"
]
} | [] | [] | [
[],
[]
] |
||
3l2vjg | rfid protection | How does RFID protection technology work? Is it just a coating that prevents a reading or is there more to it?
Background: I have an [RFID protection wallet](_URL_0_) that I put my student ID card in. If i put it in the outside id window, it CAN'T be read by the sensors however if i put it in the inside id window, it CAN be read. I'm just curious as to why this is. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3l2vjg/eli5rfid_protection/ | {
"a_id": [
"cv2od0d"
],
"score": [
2
],
"text": [
"At a high level, the wallets that offer RFID protection are very small [Faraday cages](_URL_0_) which block all EM radiation from coming in or going out.\n\nThe ID window is a hole in the cage, which allows the RFID signal to pass through."
]
} | [] | [
"http://ep.yimg.com/ay/yhst-88464523396784/tumi-delta-rfid-multi-window-card-case-8.gif"
] | [
[
"https://en.wikipedia.org/wiki/Faraday_cage"
]
] |
|
epejuu | how do drug companies decide what the dosage should be for different over the counter medication? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/epejuu/eli5_how_do_drug_companies_decide_what_the_dosage/ | {
"a_id": [
"feiyg17"
],
"score": [
6
],
"text": [
"Extensive testing, through a bunch of different phases, starting with animals and, when it’s deemed safe enough and worth the effort to move into the market, on humans"
]
} | [] | [] | [
[]
] |
||
2jo63v | why is it that we don't know much about ancient civilizations? shouldn't the information get passed across generations? | We don't know much about ancient Egypt for example. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jo63v/eli5_why_is_it_that_we_dont_know_much_about/ | {
"a_id": [
"cldikvh",
"cldiqtk",
"cldjq00",
"cldlqc8"
],
"score": [
6,
3,
4,
2
],
"text": [
"But if Civilization gets slaughtered or decimated by illness who are they going to tell their history? Our knowledge of history is based mainly on documents. If we don't have them or can't decipher them (as was long the case with hieroglyphics) we won't know much. Also do WE document our history for future civilizations? Probably not that well. ",
"This troubles me a lot too, but really what it is is evidence of the power that writing, language, and institutionalized history has on the global retention of past knowledge.\n\nI was having a conversation with a historian friend of mine about this very topic, and he raised the excellent point of complex systems in human society being responsible for this phenomena. \n\nAbsolutely everything that gives us quality of life and infrastructure in our society today is because of our ancestors putting their effort and their livelihoods into creating those systems. After dozens of generations, the cumulative work of all of these humans becomes impossible to recreate if lost.\n\nFor instance, the fall of the Roman Empire. When the Roman Empire fell, there was a significant period of intellectual and economic regression in Western Europe that we know as the Dark Ages. There is virtually ***zero*** written historical data about this period of time, and the details of what exactly happened during these few centuries is something completely shrouded in obscurity for historians. \n\nWhile the way that the Dark Ages is talked about today is a bit of a misnomer as I'm sure ***many*** historically minded people will point out to me, (China and the East in general continued to develop during the Dark Ages) it does provide interesting perspective for us as to what would happen if our society as we know it were to collapse. If the Roman roads and legions going away could cause such a massive regression for Western Europe, how many more orders of magnitude would the tragedy be if the age of information disappeared?",
" > We don't know much about ancient Egypt for example.\n\nWe know a great deal about ancient Egypt. They left countless artifacts and detailed records of their daily lives at many levels of social strata over thousands of years. We also have records of Egyptian life by writers of other cultures (Greek and Rome. The cultures we don’t know much about are the ones that didn’t leave many artifacts and records, or whose records were destroyed, or whose writing systems and languages can no longer be deciphered. ",
"Ever played the game telephone as a kid? "
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
bh2k4z | what makes some glass surfaces reflective while others are transparent? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bh2k4z/eli5_what_makes_some_glass_surfaces_reflective/ | {
"a_id": [
"elphhif"
],
"score": [
2
],
"text": [
"Light. If an object behind glass repels photons, it reflects. If it doesnt, it appears transparent as the photons continue passed it. That's how mirrors work."
]
} | [] | [] | [
[]
] |
||
3y51yf | what causes that "old" metallic-like smell in antique typewriters/cameras/sewing machines? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3y51yf/eli5_what_causes_that_old_metalliclike_smell_in/ | {
"a_id": [
"cyaloi7"
],
"score": [
8
],
"text": [
"It's actually a kind of body odor. When you touch the metal, it catalyzes the decomposition of oils on your skin and makes smaller, more volatile compounds that make up the \"metal smell.\""
]
} | [] | [] | [
[]
] |
||
9atznv | what happens in your skin when you get calluses. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9atznv/eli5_what_happens_in_your_skin_when_you_get/ | {
"a_id": [
"e4y5r7b",
"e4yibko",
"e4yn0r0",
"e4z4ooh",
"e4z9oka"
],
"score": [
446,
109,
2,
4,
3
],
"text": [
"Your skin gets tired of repairing the damage, so it over-does the repair operation - thickening the outer protective layer.",
"Podiatrist here. Thickening of keratin layer of skin - keratin is a protein that forms cross bonds in top layers of skin in this case, and being undifferentiated and dead they are great at providing protection. They are primarily caused by friction.\n\n_URL_0_ is very informative.\n\nFor true ELI5, when areas of skin are used a lot, playing the guitar for example, the skin responses to the rubbing by adding a specialised, thicker layer, due to complex biochemistry.",
"What does “starting fresh” mean? ",
"Skin feels constant pressure and hurts a lot in a certain spot so it adds more stuff to the spot to protect it better. Looks and feels funny, but it’s your skin trying to protect itself better so it can keep protecting you.",
"Your skin wants to protect itself, so you grow mermaid scales to create a barrier between you and a perceived threat to your body."
]
} | [] | [] | [
[],
[
"https://en.m.wikipedia.org/wiki/Callus"
],
[],
[],
[]
] |
||
2gebi7 | i get told beer is bad because it is all carbs and soda is bad because it is all sugar. which one is worse on my gut and why? | What am i supposed to drink? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2gebi7/eli5i_get_told_beer_is_bad_because_it_is_all/ | {
"a_id": [
"ckia518",
"ckiaeds",
"ckibr66",
"ckiiuzk"
],
"score": [
17,
2,
2,
2
],
"text": [
"Water. You're supposed to drink water",
"sugar is a form of carbohydrate. The amount of carbs in beer differs greatly depending on the type, same as the amount of sugar in sodas",
"Beer hydrates you if you don't drink to much and it's packed full of vitamins. You ever see all that shit swirling around a bottle of good beer? Vitamin goodness. ",
"Everything in moderation, my friend. Enjoy your occasional beer or soda, don't go chugging a 2-liter bottle of coke every day."
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
mfp3j | selling short in stocks, mutual funds, and margins | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/mfp3j/eli5_selling_short_in_stocks_mutual_funds_and/ | {
"a_id": [
"c30j4q5",
"c30j4q5"
],
"score": [
21,
21
],
"text": [
"**Short selling: **\n\nYou have 100 stocks in a company that you plan on keeping regardless of what happens to its price. Lets say they're worth 100$ a piece. Now I think that the price is going to take a shit-kicking. So I tell you, 'Hey, if you let me borrow your 100 stocks for a month, I'll give them back to you and give you a bit of commission for your trouble'. You say 'awesome. Here, take them!'. So now I have those stocks, but I owe you them back in a month. I sell those stocks right away, so now I have 10k in cash. If I'm right and the stock drops to 50 the next day, I can buy those 100 stocks back at the lower price and return them to you. I make $5k, which is the difference between the lower and higher price of the stock. \n\nWhere this gets dangerous is when the stock goes *up* instead of down. Because I've promised to return those stocks and I've already sold them, if the price goes up, I still have to buy them back. So you can actually end up losing money. Lets say I have to pay 110 each for them. You don't care because you get your stock and commission, but I'm out $1000!\n\n\n**Mutual Funds:**\n\nMutual Funds: Basically, a bunch of people pool their money to buy stocks and other investments. You buy a percentage of that mutual fund. If the value of the investments that fund owns goes up, your share of the fund is more valuable. If you sell your share, you get your money back plus what the value increased by, less a commission. Mind you, it's just like a stock in the sense that it's value can drop too.\n\n**Margins:**\n\nMargins are the percentage gain you stand to make. Say you're going to sell something to a friend. You're going to sell it for $100, but it cost you $80 to get in the first place. Your margin is 20%. Or in other words, you're marking it up by 25%.\n \nIn terms of stocks, it's the difference between what you buy a stock at and what you sell it for, less fees for things like brokers. \n\nEDIT: margins aren't the percentage, but rather just the difference in what you paid vs sell for. They can be shown in trims of percentage or actual value.",
"**Short selling: **\n\nYou have 100 stocks in a company that you plan on keeping regardless of what happens to its price. Lets say they're worth 100$ a piece. Now I think that the price is going to take a shit-kicking. So I tell you, 'Hey, if you let me borrow your 100 stocks for a month, I'll give them back to you and give you a bit of commission for your trouble'. You say 'awesome. Here, take them!'. So now I have those stocks, but I owe you them back in a month. I sell those stocks right away, so now I have 10k in cash. If I'm right and the stock drops to 50 the next day, I can buy those 100 stocks back at the lower price and return them to you. I make $5k, which is the difference between the lower and higher price of the stock. \n\nWhere this gets dangerous is when the stock goes *up* instead of down. Because I've promised to return those stocks and I've already sold them, if the price goes up, I still have to buy them back. So you can actually end up losing money. Lets say I have to pay 110 each for them. You don't care because you get your stock and commission, but I'm out $1000!\n\n\n**Mutual Funds:**\n\nMutual Funds: Basically, a bunch of people pool their money to buy stocks and other investments. You buy a percentage of that mutual fund. If the value of the investments that fund owns goes up, your share of the fund is more valuable. If you sell your share, you get your money back plus what the value increased by, less a commission. Mind you, it's just like a stock in the sense that it's value can drop too.\n\n**Margins:**\n\nMargins are the percentage gain you stand to make. Say you're going to sell something to a friend. You're going to sell it for $100, but it cost you $80 to get in the first place. Your margin is 20%. Or in other words, you're marking it up by 25%.\n \nIn terms of stocks, it's the difference between what you buy a stock at and what you sell it for, less fees for things like brokers. \n\nEDIT: margins aren't the percentage, but rather just the difference in what you paid vs sell for. They can be shown in trims of percentage or actual value."
]
} | [] | [] | [
[],
[]
] |
||
1rl88r | why does the pitch of an emergency siren change when it has gone past you? | I wonder why the pitch of a siren changes when it is going past you at a fast speed. It sounds different when it is moving at you and when it is moving away from you. As an example Swedish siren: _URL_0_
Is there any physical explanation to this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1rl88r/eli5_why_does_the_pitch_of_an_emergency_siren/ | {
"a_id": [
"cdoccos",
"cdoehyz",
"cdoelqv"
],
"score": [
11,
2,
5
],
"text": [
"The sound waves bunch up ahead of the vehicle, making out sound higher, and as it passes you, they spread out behind out, lowering the frequency. Google \"Doppler effect\"",
"[The Doppler Effect](_URL_0_)",
"I learned about the Doppler effect from Dewey on Malcom in the Middle"
]
} | [] | [
"http://www.youtube.com/watch?v=ALnMzTC-144"
] | [
[],
[
"http://www.sheldonquotes.com/uploads/Doppler.gif"
],
[]
] |
|
3jqo3b | why do we clinch our teeth while applying force? | Whenever we open a box lid which is very tight or push something heavy (like a car), we tend to clinch our teeth.
Was curious why this happens. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3jqo3b/eli5_why_do_we_clinch_our_teeth_while_applying/ | {
"a_id": [
"curmr77"
],
"score": [
11
],
"text": [
"Imagine force as pressure, like the pressure of soda in a bottle. We feel the pressure because the soda is pushing against the walls of the bottle. If the cap is off the bottle, there is no pressure: the walls of the bottle are squishable. When the cap is on the bottle becomes stiff. \n\nOur bodies are the same way. In order for muscles to exert pressure, they need to be pushing against a closed container. We close our bodies by closing our vocal cords. Clenching your jaw is another way to put extra pressure against the vocal cords.\n\n\nI can give more details about why this is effective and how it works if you're interested.\nSource: I'm a speech and swallowing therapist. I work with vocal cords."
]
} | [] | [] | [
[]
] |
|
3rnz3m | nasa's latest announcement about mars' atmosphere | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3rnz3m/eli5_nasas_latest_announcement_about_mars/ | {
"a_id": [
"cwpqokd",
"cwprgfm",
"cwpuzcs"
],
"score": [
2,
27,
5
],
"text": [
"Mars' Atmosphere is being stripped from a tiny fraction of its' Gas every second (about 100g/seconds globally on rough estimates) due to Solar Winds. \n\nI just tuned into the Livestream myself, if you want to know anything specific, let me know, and I'll get back to you once i learn more. :)",
"EDIT: More ELI5 answer:\n\nA long time ago Mars had plenty of water flowing on its surface. Shortly after the flowing water was there Mars lost its magnetic field. The magnetic field is caused by melted metal inside of Mars moving around; the same way Earth gets its magnetic field. The metal cooled and became solid faster than Earth's because Mars is smaller and Earth has more radioactive rocks inside of it heating it like a nuclear reactor.\n\nThis magnetic field was like a shield for Mars. This \"shield\" protected Mars from the Sun. When Mars lost its shield so long ago it was exposed to the Sun's winds which blew the air off of Mars and evaporated all the water on Mars too! The water was blown off of Mars and lost to space as well.\n\nMars is still losing its atomosphere at a rate of 100 grams a second (that's about as much as a cheeseburger!).\n\nOriginal post: Mars' lost its magnetic field about 4.2 billion years ago which then allowed solar winds to, over the 500 million years, \"blow\" away Mars' atmosphere. Before that time water had been \"abundant and active\" on Mars.\n\nCurrently, from rough estimates, Mars' atmosphere is being lost at a rate of 100 grams, or 1/4 pound, per second.",
"So say it was possible to terraform mars. If the planet no longer has a core capable of producing a magnetic field..wouldnt the atmosphere we try to create just continue to be wiped away by solar winds? "
]
} | [] | [] | [
[],
[],
[]
] |
||
1zrnjk | why do restaurants offer and promote "healthy options" and then give you a tiny water glass? | So one of the easiest and Healthiest decisions I have made lately is totally ditching sugary drinks in exchange for water. Now this is lovely but a ton of restaurants (specifically fast food places) offer a tiny water glass. Is there a reason for this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1zrnjk/eli5_why_do_restaurants_offer_and_promote_healthy/ | {
"a_id": [
"cfwaz7g",
"cfwb7ba"
],
"score": [
2,
2
],
"text": [
"The most expensive part of a fountain drink is the cup itself so many fast food restaurants is to hand out the cheapest container they have. ",
"For most restaurants, it's because it doesn't make money. Not only do they have to offer free water, but imagine the labor costs to bus away and wash all those cups, and the money it costs to keep the dishwasher going. Smaller dishes means less time to get everything clean."
]
} | [] | [] | [
[],
[]
] |
|
6yligy | why was the recent eclipse scientifically important? | I read online that scientists went crazy during the day of the eclipse to get some important data on the corona or whatever. That I get. What I *don't* get is why is it important that the moon block the sun? Why can't we just put a vantablack circle in front of a telescope and have an eclipse 24/7?
TL;DR: Why can't we artificially recreate the eclipse in a smaller scale for scientific purposes. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6yligy/eli5_why_was_the_recent_eclipse_scientifically/ | {
"a_id": [
"dmoazw0",
"dmob5jp"
],
"score": [
3,
3
],
"text": [
"The result would not be the same. The sun's light is being blocked from outside the atmosphere. There is only one way to do that, that being with a celestial body with the same apparent diameter. It's also remarkable because of the relative rarity with which these events happen in a given location. ",
"Well scientifically, the recent eclipse is indeed not too interesting or important, many eclipses happen and this one isn’t really unique. People hype it up though and scientists join in mainly to spread scientific awareness and interest in science.\n\nThat being said, as for your question about the corona, we cannot block the sun but leave the corona within the atmosphere since the atmosphere distorts the sunlight and makes it seem such that sunlight is coming from where the corona is supposed to be, making poor measurements, even when blocking out the center of the sun. This still isn’t that much of an issue though, mainly because we have space telescopes which exist in part because of this. "
]
} | [] | [] | [
[],
[]
] |
|
4zwjac | if you flew a spacecraft into a gas planet, would you go straight through it or would you hit some form of ground? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4zwjac/eli5_if_you_flew_a_spacecraft_into_a_gas_planet/ | {
"a_id": [
"d6zf9y6",
"d6zfirm",
"d6zge0k"
],
"score": [
2,
3,
3
],
"text": [
"Your be crushed by the gravity of the planet long before you reached the center let alone got to the other side.",
"It's believed that most, if not all, gas giants have solid cores. However, the pressure of the atmosphere (not the gravity) would crush your craft LONG before you got to the core. We did send the Galileo probe down into Jupiter's atmosphere, it lasted about 78 minutes before it got crushed like a bug.\n",
"That's pretty much why we've sent Juno up to Jupiter; I understand that it's going to be firing some kind of radar through the atmosphere to see what reflections come back.\n\nThere are also theories that due to the extreme pressure, the core may contain phase 5 hydrogen, a state in which it forms into a metallic structure.\n\n_URL_0_"
]
} | [] | [] | [
[],
[],
[
"http://stateschronicle.com/hydrogen-fifth-state-of-matter-phase-v-16033.html"
]
] |
||
2vwmyl | how does old and worn money get out of the circulation? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2vwmyl/eli5_how_does_old_and_worn_money_get_out_of_the/ | {
"a_id": [
"colizsj",
"colkmo0"
],
"score": [
4,
2
],
"text": [
"One thing that banks do is when they see a bill that's getting too worn out is they send it back to the treasury department and get a replacement. The treasury department destroys them.",
"Banks don't keep the cash that they get as deposits. The cash is bundled up and sent back to the Federal Reserve. The Fed destroys worn out bills and damaged coins."
]
} | [] | [] | [
[],
[]
] |
||
be64sl | why do large scale fires take so long to be put out? | I'm thinking more in terms of localized fires like the Notre Dame one rather than a forest/bush fire. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/be64sl/eli5_why_do_large_scale_fires_take_so_long_to_be/ | {
"a_id": [
"el3b30n",
"el3dv74"
],
"score": [
7,
3
],
"text": [
"Thats happens because of how the fire works. In order for fire to burn, you need fuel, heat, and oxygen. Now, its not enough to just locally remove oxygen or energy for a moment. You need an orchestrated effort to keep situation controlled until its all extinguished.\n\n\nIf you dont, dangerous things happen (like, for example, backdraft, if you let the fire smoulder in a closed, heated room, and let the oxygen back in - and thats how many firefighters died, too). Even house fires generate temperatures close to 1000 C easily.\n\nAnd, you cannot just drop several tens of tons of water down. You'd obliterate the building if you did so. Which kinda defeats the purpose of saving as much as possible.\n\n And im not even getting into specyfic situations like dealing with chemicals (even cooking oil fire on the frying pan - dont douse that with water, because it will be quite violent/explosive!) or high (or even standard 220V) voltage systems fires...",
"A fully burning house is more of an inferno than a campfire. \nYou can extinguish a candle with a glass of water, but if the Fire gets bigger, it also accelerates itself, more rising Gases may cause more Oxygen to get pulled in, more heat causes more Fire, and soon a much bigger amount of Fuel is at a much higher temperature and is burning itself. While wood starts burning at around 300°C, a big fire can easily surpass 1000°C and become quite hard to extinguish."
]
} | [] | [] | [
[],
[]
] |
|
2zmfpa | i'm making hot dogs in the microwave. the packaging says "1 hot dog is 30 sec but 2 or more are a minute and 10 sec" why do i have to increase time when making more than one? won't they cook the same for the time of 1 hot dog? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2zmfpa/eli5_im_making_hot_dogs_in_the_microwave_the/ | {
"a_id": [
"cpk97h3",
"cpk9rtp"
],
"score": [
2,
3
],
"text": [
"The waves have to go through more matter to do their thing. So you increase the time of exposure to the waves to compensate.",
"Your microwave oven outputs microwaves (pretty self-explanatory), for regular cooking (not defrost or simar functions), the microwave oven outputs a fixed rate of microwaves. Since there is a fixed amount, more things to cook means less microwaves for each. \n \nThink of it like putting a splitter on a garden hose to fill up two buckets, the same amount of water is coming out, but each bucket is getting half the water that is being outputted. Now, this isn't the perfect analogy because the cooking time isn't being halved, but you get the point."
]
} | [] | [] | [
[],
[]
] |
||
2x9ken | how exactly does one "evade" taxes? kinda curious how ~100 billion euros could be missed. (assuming story truth) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2x9ken/eli5_how_exactly_does_one_evade_taxes_kinda/ | {
"a_id": [
"coy4400",
"coy4tb1",
"coy8o3l"
],
"score": [
5,
4,
2
],
"text": [
"When you work at a company, they keep track of how much you are being paid, and then tell the tax authority that number - so when you file your taxes, the number you say you earned had better match the number your employer told them. But... if your income isn't coming directly from a company - say you are a waitress who gets paid in tips, or you rent out a few houses, or are self-employed, or have other investments that don't have strict IRS reporting rules - then it is up to you alone to report how much you earned and how much tax you owe on it. You 'evade' taxes by reporting a lower number than what you actually should - the way you do that varies greatly by how you got the money in the first place, and how large that sum of money is, but the general gist is you simply hide income that you should be paying taxes on.",
"Just throwing this out there: lots of under the table jobs and no one filing taxes. ",
"Well those people who do that are very rich and smart and on top of that they can hire really smart bankers for them to hide their money. "
]
} | [] | [] | [
[],
[],
[]
] |
||
1y2wff | how do people get caught for illegal downloads and prosecuted? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1y2wff/eli5_how_do_people_get_caught_for_illegal/ | {
"a_id": [
"cfgv805",
"cfgxa6x",
"cfgyefe",
"cfh4jqg",
"cfh8hkm"
],
"score": [
16,
3,
3,
2,
2
],
"text": [
"The overwhelming majority of people do not get caught. Piracy is treated in a similar manner to drug dealing. They let the little guys operate and go after the boss, i.e. they let you, the downloader, pirate and go after the guy who uploaded it instead. \n\n\nThere was a story about a guy who uploaded the new Fast & furious movie in the UK recently, his house was raided by armed police. They really don't care if you download it, they want the people distributing it more than anything. [Here's the story](_URL_0_).\n\n\n\nFun fact, cinema staff in the UK are given a huge cash reward for reporting people who are recording movies. I worked in a cinema for three years.",
"They look at your IP address, subpoena your ISP and get your personal information and address. The fact that your IP was downloading or uploading (or both in the case of Bittorent) is used as evidence against you.\n\nNote that recently many courts have ruled that an IP address alone isn't sufficient evidence against an individual.\n\n",
"We use BitTorrent and after downloading we erase all files and whatever and transfer the movie to our Time Capsule, well my girlfriends brother lives with us and he forgot to delete the files inside the BitTorrent program after he downloaded a few movies and since his computer was connected to our internet they used our IP address to find out exactly what was downloaded and at what date and time and sent us a warning letter. I suppose if you don't heed that letter they call the police or FBI or whatever. ",
"I had gotten a letter through my ISP from FOX once for sharing a movie. I downloaded it and seeded it (during or after the download, I forget). FOX demanded I contact them for sharing their movie in the letter they sent my ISP that my ISP forwarded to me. My ISP did not give them my personal information as it was against policy, surprisingly, and it seems FOX was hoping I would directly answer their letter and thereby give them my personal information. I ignored it and changed my downloading/uploading habits and never had another problem. ",
"First of all, nobody gets caught for \"illegal downloads.\" If you find something being distributed on the internet, you are within your rights to assume that whoever is distributing the file is the copyright holder, or has permission from the copyright holder.\n\nSome people get caught for uploading files. Generally P2P programs like Bittorrent. When you use your client to connect to the Bittorrent swarm, your client finds IP addresses of people who have the file you are looking for. \"They,\" the \"copyright police,\" use specialized clients that will find the IP addresses, log them, and then try to download an entire file from one IP address. That way, they can say that that IP address was distributing that file.\n\nOthers have answered from this point."
]
} | [] | [] | [
[
"https://torrentfreak.com/five-undercover-police-cars-sent-to-arrest-single-alleged-movie-pirate-130525/"
],
[],
[],
[],
[]
] |
||
529lyr | what laws in europen union is uniform throughout? what kind of laws can vary between the member countries? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/529lyr/eli5_what_laws_in_europen_union_is_uniform/ | {
"a_id": [
"d7ip677"
],
"score": [
3
],
"text": [
"There are EU directives, decisions and EU regulations\n\nDirectives aim to achieve a specific outcome but it's up to the member state how to implement it\n\nRegulations are binding laws throughout every Member State and enter into force on a set date.\n\nDecisions are EU laws relating to specific cases and directed to individual or several Member States, companies or private individuals. They are binding upon those to whom they are directed.\n\n_URL_0_"
]
} | [] | [] | [
[
"http://www.usda-eu.org/eu-basics-questions/difference-between-a-regulation-directive-and-decision/"
]
] |
||
amzpo4 | if anything is moving away with constant speed from each other, why distant objects appear faster? | Edit : I'm talking about the expansion of the universe. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/amzpo4/eli5_if_anything_is_moving_away_with_constant/ | {
"a_id": [
"efpqbgi",
"efpqzlc"
],
"score": [
4,
3
],
"text": [
"In what context does that happen? \n\nIf you stand and look at moving objects the closer they are the faster they appear because the angular size changes faster. Angular size there size in your field of view. \n\nThe size of a object approximate half in size at twine the distance so something that move from 200m to 100m away get twice as large the same for the movement from 100m to 50m. At constant speed the time to move from 100m to 50m is half of 200m to 100m so the rate it changes size at is twice as high.\n\nEven if they move perpendicular to you the speed look faster if they are closer so a airplane in the sky do not look that fast compared to a car that drive just in front of you,\n\nSo when you look at thing the opposite to your question is true.",
"I believe you misunderstood the \"constant\" part.\n\nA galaxy only moves away with constant speed in the sense that it doenst speed up or slow down. It does not mean that all galaxies move away with the same speed.\n\nIn case you are referring to the hubble-constant, that constant is not a speed. Its not something like \"70 km/s\" , it is \\~70 km/s/Mpc. (Mpc being a kinda odd unit of distance).\n\nThis means that a galaxy at a distance of 1Mpc will move away with \\~70km/s, a galaxy at 2Mpc with 140km/s, and so on."
]
} | [] | [] | [
[],
[]
] |
|
247n8h | cherenkov effect: how can something travel faster than the speed of light? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/247n8h/eli5cherenkov_effect_how_can_something_travel/ | {
"a_id": [
"ch4dpqj",
"ch4mqcp"
],
"score": [
10,
2
],
"text": [
"The particles that cause Cerenkov radiation don't actually travel faster than *c*, the speed of light in a vacuum, they travel faster than the speed of light in the medium in which that light is propagating.\n\nYou can kind of think of it like a sonic boom, light in water doesn't travel at its maximum speed, but rather at a fraction of it. The particles emitted from the reactor or whatever are traveling faster than the speed that light can travel in water, which causes the light to propagate at angles to them rather than straight away. Like a sonic boom, where the sound waves can't travel faster than object moving faster than the speed of sound, and so they propagate at angles to the object rather than straight away from it.",
"Cherenkov radiation happens when particles travel faster than the speed of light *in that medium*, which is lower than the speed of light in a vacuum. And that's the important thing: the vacuum speed of light is the speed that is \"universal speed limit\". Light travels faster through a vacuum than it does through a medium (water, for example), so particles can be traveling through water faster than the speed at which light travels through that medium, yet slower than that light would be traveling if it were in a vacuum."
]
} | [] | [] | [
[],
[]
] |
||
eem80e | why do humans have a natural tendency to seek approval? what makes humans social beings? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/eem80e/eli5_why_do_humans_have_a_natural_tendency_to/ | {
"a_id": [
"fbuqdzg"
],
"score": [
3
],
"text": [
"We evolved as such. We cannot survive well on our own, and our survival is tied to the herd. The dynamics of the herd, what we consider being social, are thus very important to our survival."
]
} | [] | [] | [
[]
] |
||
8cuozx | how to properly use articles in english? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8cuozx/eli5_how_to_properly_use_articles_in_english/ | {
"a_id": [
"dxhz2me",
"dxhzglr"
],
"score": [
3,
2
],
"text": [
"\"a\" is for a non-specific noun. If you're talking about \"a dog\" its usually just any dog. The concept of a dog. Or some random dog.\n\n\"an\" is the same as \"a\" but you use it if the following word starts with a vowel. \"I want to eat an apple\" means that I'll eat any apple you give me.\n\n\"the\" is for a specific noun. \"I fed the dog\" means that we already know which dog we're talking about, and that was the dog I fed. \"I fed a dog\" means that I fed some random dog you don't know.\n\nExample:\n\n\"I met a dog today. The dog was cute.\"\n\nI start out with \"a\" because from your point of view it was just an unknown dog. Now that we've established a specific dog (the one I met), I switch to \"the\" for the next sentence. Because we both know I'm talking about the dog I met.\n\nIf I said \"I met **the** dog today\" it would imply that you already know what dog I'm talking about. Maybe we had a conversation about a specific dog earlier. If you say \"the\" without context people will get confused and wonder if they should know which dog you're talking about.\n\nIf I said \"**A** dog was cute.\" Then I'm saying that some dog, somewhere was cute. Which is probably true! But it's kind of a useless sentence because neither of us know which dog I'm talking about.\n\nalso: wow it's really hard to describe a language while using that very same language.",
"Yes, this is a very difficult problem for speakers of Slavic languages. The general rule of thumb is that the definite article \"the\" is used when you can be sure that the person you're talking to knows exactly which individual thing you're talking about.\n\nConsider this conversation:\n\n\"I can see **a cat** in our garden.\" \n\"Wow, that's strange. What is **the cat** doing?\"\n\nThe first speaker says \"a cat\" because this is the first time the cat has been mentioned in this conversation. It could be any cat that lives nearby.\n\nBut after that, the speakers switch to saying \"the cat\". This basically means: \"the cat which we are now talking about, the cat which the first speaker has seen\".\n\nIf a new cat arrives, the indefinite article is used to mean: \"This is another cat, not the same cat we were just talking about\":\n\n\"Look at that! There's **a cat** over there as well!\"\n\nLook at these two sentences:\n\n* This is a house that Jack built.\n* This is the house that Jack built.\n\nIn the first sentence, we know that Jack built more than one house. This is only one of them. In the second sentence, we know that Jack only built one house, and this is it. Simply by saying \"house that Jack built\" we have uniquely identified the exact house.\n\nHere are a couple more sentences:\n\n* Elizabeth I was a queen of England.\n* The Queen opened a new supermarket today.\n\nIn the first sentence, we are saying that of the several queens of England there have been, Elizabeth I was one of them. In the second sentence, we are talking about the person who is at the moment the reigning queen of the country we are in -- if we're in the UK, that would be Queen Elizabeth II.\n\nThere are many more subtleties to this, but this is the most basic rule: using the definite article \"the\" is a signal that means: \"I don't have to explain to you exactly which thing we're talking about, because it's obvious.\""
]
} | [] | [] | [
[],
[]
] |
||
arzoa8 | why can't we see living cells through electron microscope? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/arzoa8/eli5_why_cant_we_see_living_cells_through/ | {
"a_id": [
"egqp6um"
],
"score": [
3
],
"text": [
"Mostly because an electron microscope has to operate in a vacuum. Living cells don't care much for those.\n\n & #x200B;\n\nAlso, sometimes what you're looking at under a scanning electron microscope has to be covered with a very very very very thin layer of a metal (known as sputter coating) to make the image come out better, and that would definitely be counter productive to life.\n\n & #x200B;"
]
} | [] | [] | [
[]
] |
|
bgfg2g | how does someone die by swallowing his tongue? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bgfg2g/eli5_how_does_someone_die_by_swallowing_his_tongue/ | {
"a_id": [
"elkd6ks",
"elkdhuq"
],
"score": [
4,
7
],
"text": [
"You don’t literally swallow your tongue. Basically as your on your back your tongue moves to the back of your mouth and blocks your air passage.",
"Almost 100% certain this is a myth your tounge is attached to the bottom of your mouth making swallowing it impossible."
]
} | [] | [] | [
[],
[]
] |
|
jum1h | what is the current role of the national guard? | My best friend recently joined the guard and with the state of things nowadays I really have no idea what that means she will be doing. Can someone please explain to me what exactly people in the National Guard have traditionally done and what it is they do now? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jum1h/what_is_the_current_role_of_the_national_guard/ | {
"a_id": [
"c2f9bgr",
"c2f9bgr"
],
"score": [
2,
2
],
"text": [
"To send you mail asking you to join.",
"To send you mail asking you to join."
]
} | [] | [] | [
[],
[]
] |
|
7w7104 | why can a defibrillator help reset abnormal cardiac rhythms but can’t restart a heart? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7w7104/eli5_why_can_a_defibrillator_help_reset_abnormal/ | {
"a_id": [
"dty086e",
"dty7fo8"
],
"score": [
7,
2
],
"text": [
"A defibrillator effectively stops an abnormal rhythm by briefly stopping the heart's activity, interrupting the irregularity and allowing the normal rhythm to resume. In a stopped heart, \"stopping the heart more\" doesn't help anything. Whatever root cause that resulted in it stopping needs to be corrected, be that a lack of blood, lack of oxygen, hypothermia, etc. Delivering a shock to the heart doesn't do anything to correct these issues. ",
"Have you ever seen an orchestra? theres one dude up there keeping beat and signaling, he's kind of a singular figure everyone can look at and make sure they're following along with everyone else, even if they can't actually hear the violas or the bass, they all know theyre playing correctly. The heart kinda works like that, there's these things called pacemaker cells which is where the electrical signal for the heart comes from, and goes through heart telling it to contract in a certain way at a certain time for optimal blood flow.\n\nImagine now, if the conductor steps down for a minute, and the cellists can hear that theyre now playing slower than the violinists, and the viola players cant tell that theyre playing faster than the bass players and it pretty quickly turns to a horrible mess of sound with no sense. In the heart the cells are all doing their own thing, and contracting at different times.\n\nThe defibrillation is like if the conductor steps up and everyone suddenly can see the right tempo and beat, and everyone gets back on track. Similarly, a defibrillator sends a new, overriding pulse through the heart to get all the cells back in line with the original pacemaker cells."
]
} | [] | [] | [
[],
[]
] |
||
dy3qgc | why can we control body functions like are hands and feet, or even when we have to pee, but we can’t control the inside of our body? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dy3qgc/eli5_why_can_we_control_body_functions_like_are/ | {
"a_id": [
"f7y5ja6",
"f7y7tds"
],
"score": [
6,
2
],
"text": [
"Because during evolution it didnt provide people with statistically significant advantage.\n\nThe way evolution works is, random mutations happen, and if these mutations help the creature survive, that creature can produce more children, passing on the mutation. Eventually, if it helps more and more creatures survive, majority of creatures end up possessing that trait.\n\nYou cant stop sending blood to pinky toe because if a child was born that way millions of years ago, that child did not have any significant survival advantage, and thus was unable to keep passing its genes.",
"There are voluntary action and involuntary action. Your brain’s core purpose is to keep you alive - nothing else matters. Therefor the functions necessary to keep you alive are automated. Your brain is in control of those complex functions and responds to your body chemistry which essentially tells the brain how healthy the body is and if adjustments are needed. That is why medical science can rely on blood tests to diagnose problems - those blood tests look for the things we know about the blood characteristics of a healthy body compared to what we know about the blood characteristics of various diseases. \n\nYour voluntary actions are the things you consciously tell your brain to do because you choose to. Knowing that the human condition of consciousness is not always perfect, the brain does allow the core survival skills to be voluntarily controlled. \n\nFor example, if you were living a thousand years ago, out hunting with your tribe, if you had to decide when to breathe and when you needed a jolt of adrenaline, while deciding which muscles to use to help your stomach digest your last meal as well as notice that your foot was cold and send blood circulation in that direction so the foot does not go numb as you stand, it would be very very difficult to catch that deer and in the end, you would likely starve to death or become sick bc you are malnourished. \n\nAn even better example would be that you have to make all of those internal bodily function decisions when you unexpectedly encountered a large predator like a grizzly bear. Odds are the need to process internal function decisions would interfere with your escape from the predator. \n\nYour brain can autopilot you body’s necessary function far faster than you can carry out deliberate conscious actions. If the internal activity that runs in the background while you do other things were to be made into conscious decisions, you would not survive.\n\nNote: none of this is absolute. There are cases where individuals have shown the ability to control aspects of their involuntary body functions. Bruce Lee trained to consciously control his breathing rate and could consciously raise and lower his blood pressure. There are other examples - many in eastern practices that focus on meditation and developing a better understanding of your body and the power of your mind."
]
} | [] | [] | [
[],
[]
] |
||
419seq | - who are corrupt bankers and why are they so evil? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/419seq/eli5_who_are_corrupt_bankers_and_why_are_they_so/ | {
"a_id": [
"cz0nneg",
"cz0ns0g"
],
"score": [
2,
2
],
"text": [
"From an article on island\n > \n > Their crimes include market manipulation, embezzlement, and breach of fiduciary duties. Their market manipulation destroyed the country’s economy and to this day Iceland is still having to repay the global loan sharks at the IMF, as well as governments of other countries, which kept the nation operating.\n > The article explains that the prosecutions have been possible because rather than protect and reward the very institutions responsible for the collapse, and the gangsters that run them, the Icelandic government let them fail, and then created a financial supervisory authority to strictly oversee the banks.\n",
"They aren't \"evil\". Evil is a word we give to people we don't like too often. They love money, as most of us do, and have the intelligence to earn a ton of it. If they don't break laws and still are able to manipulate and do things we would frown upon, that is a problem with our laws. If they do break laws and are punished in no way and instead are gifted billions by the government... that is a deep seated problem of government corruption more than bank corruption."
]
} | [] | [] | [
[],
[]
] |
Subsets and Splits