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 |
|---|---|---|---|---|---|---|---|---|---|
21w5iz | how did glow in the dark happen? and where did it get its source of energy to glow in the dark? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/21w5iz/eli5_how_did_glow_in_the_dark_happen_and_where/ | {
"a_id": [
"cgh4ehd",
"cgh5gis"
],
"score": [
10,
3
],
"text": [
"Around 1669, there was a German alchemist named Hennig Brand. He was in search of gold, and thought that it came from within man. What color is gold? It's a shade of yellow. What else is yellow that everyone is familiar with? Urine. So off went Hennig on a quest to extract gold from pee. He boiled down 5,500 liters of the stuff, and what was left over was a bunch of phosphorus. Phosphorus, for those who don't know, has a tendency to take in light, and hold it for a while, which makes it glow. This is why Hennig named it phosphorus, for the greek \"light-bearer\".\nSo glow in the dark resulted from a scientific fluke. The dude was trying to make gold in an early stab at chemistry.",
"To add to redfoot's answer. If your super lucky, your glow in the dark stuff is not made of phosphors that are energised with light radiation but with decomposing uranium. Before we realised how dangerous that stuff was it got stuck in a lot of things. Watches and kids toys from the 40-60's, if they glow, can contain uranium"
]
} | [] | [] | [
[],
[]
] |
||
2movzc | why are ceiling's spackled or whatever it's called. why aren't they just flat like walls? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2movzc/eli5why_are_ceilings_spackled_or_whatever_its/ | {
"a_id": [
"cm67cs6",
"cm67ea1",
"cm6aqf6",
"cm6bl68",
"cm6cgsf",
"cm6chvu",
"cm6sdp1"
],
"score": [
27,
6,
28,
9,
2,
7,
2
],
"text": [
"It's sound damping. Flat surfaces echo more than dimpled ones. ",
"Spackling is the use of spackle to fill holes and cracks. I assume you mean that textured finish on some ceilings. If so, that's just a design choice and doesn't have any practical reason.",
"I work in new home construction in a mid-Atlantic market. We do smooth ceilings (you are describing textured). In my market textured is about 50% of the multifamily housing market and about 0% of the single family market. From my perspective you do this more to hide imperfections in drywall seams than as a sound dampening device. In multifamily it also hides wear and tear where a tenant my cause dents moving in/out of a unit.",
"I always suspected it was to hide a shitty mudding job. ",
"I just recently bought a house and that was one of the first things I did. Scrape all that popcorn crap off the ceilings and make them flat. After checking for asbestos, of course.",
"Major home builders texture walls and ceilings because the texture hides the crappy job their laborers do. These home builders spend as little money as possible on labor (undocumented and barely legal migrant workers compose a significant amount of their workforce, especially in the southwest) and as such, they get what they pay for. Walls aren't flat or plumb, ceilings are not even close to level, and corners are almost never true. As such, they coat every surface possible with texture, which makes it more difficult for eyes to pick up on the imperfections.\n\nSource: A friend of mine oversaw regional construction related business for a major homebuilder in the southwest until the housing bust.",
"It's mostly about labor costs and appearance. \n\nIt's not all that easy from a modern craftsmanship standpoint to get flat, smooth ceilings that hide the seams in the drywall. \n\nIn old houses that haven't been renovated you'll often see smooth ceilings. As I understand it, this is because they were plaster and the plasterers had the skill to make it look flat and smooth."
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[]
] |
||
8vomp8 | why does using a tootbrush how we do not make us sick? it is never sanitised and sit in your bathroom all day. | Sorry about the terrible title I posted right before I went to sleep after I brushed my teeth. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8vomp8/eli5_why_does_using_a_tootbrush_how_we_do_not/ | {
"a_id": [
"e1p3epc",
"e1p5b2w",
"e1pb7bm",
"e1pixrf",
"e1plhx1",
"e1pngu3",
"e1putwj",
"e1q0t5h",
"e1q13zf",
"e1q7vmr",
"e1qr3r4"
],
"score": [
12,
306,
5675,
18,
399,
11,
10,
11,
8,
14,
3
],
"text": [
"Not to mention every time you flush with the lid up the flushing motion causes tons of tiny poo particles to be thrown in the air which settles on anything nearby, such as a tooth brush.\n\nThe immune system is fighting off infection 24/7. Not just when you contract a disease. Plus the bristles are plastic, designed to resist contamination. And you generally rinse it off before and after each use.\n\nBut still is why you need a new one every couple months.",
"A tooth brush is not a disinfecting agent. It's meant to scrape away excess food, not kill bacteria. Your mouth is ahead good enough at dealing with bacteria; removing excess carbohydrates by brushing just limits bacterial growth.",
"Soap, your faucet, your tooth brush, the glass you drink water out of, all has bacteria on it. We don't live in a sterile environment and we ourselves are not sterile. You have more bacteria in your mouth, and fungal spores, than on your tooth brush. \n\nHaving bacteria isn't the problem, it's having a place for bacteria to multiply and grow into a colony unopposed and for that you need food, water, shelter, and no competition. Your tooth brush has only one of those things. \n\nThe job of a tooth brush is not to sterilize your mouth, it's to wash away the metabolic junk and plaque that eats away at your teeth. It denies the colonies in your mouth food and a medium to safely grow in (plaque). ",
"Might not be relevant, but I dip my tooth brush in listerine for a minute every other week ........ 99.9 percent effective ",
"Your mouth is dirtier than your toothbrush. The longer you go without brushing your teeth, the cleaner your toothbrush is. Your mouth is the contaminant. Not dissing anyone's specific mouth - this applies to all humans.",
"Sure, your toothbrush is full of germs, but they're *your* germs (unless someone else is using your toothbrush). ",
"Same reason toddlers don't sporadically die even though they put all kinds of random shit in their mouths when you aren't looking.\n\n\nIf we were reliant on our own sanitation efforts to keep from getting sick (washing our hands, sterilizing eating utensils etc.) we would be long since dead.\n\n\nIt feels good to wash your hands and feel like all the evil bacteria is gone, but that's mostly naive first world logic, its not that simple. And someday we may arrive at the collective conclusion that antibacterial soaps are simply not necessary for everyday use (discounting things like surgery, idk).",
"A few things:\n\n* Toothbrushes are cleaner than you think; most dangerous bacteria needs moisture and nourishment to survive, and really only replicates quickly in warmth. Your toothbrush dries out, is (hopefully) rinsed thoroughly to limit resources for the bacteria to thrive on, etc.\n\n* Your immune system is amazing; it's a lot harder to get sick from exposure to bacteria than you imagine. If it *weren't*, you'd be constantly sick.\n\n* Most of the bacteria on your toothbrush isn't novel; the bacteria in the bathroom is mostly stuff you and your housemates have already been exposed to, and which your immune system is therefore already dealing with. Having a bit on your toothbrush isn't likely to significantly alter your risk.\n\nThat said, it's pretty easy to disinfect a toothbrush by swishing it in an antiseptic mouthwash (e.g. listerine) for 60 seconds, so if it's a worry, it's easy to mitigate the risk.",
"Because in general modern society is excessively paranoid about germs but our bodies are exceptionally good at not getting sick. ",
"Because there's nothing on your toothbrush that isn't already in your body.\n\nYou know you can walk outside and eat dirt and be fine right? Kids do it all the time.\n\nYour body has a robust immune system.",
"Ye the bacteria are strong, but fear not your immune system is stronger. I mean your mouth is covered in bacteria too. Not all bacteria is bad bacteria and your body has ways of kind of keeping bacteria out of where it's supposed to be."
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
|
1mycgj | what are the reasons as to why the oil price never return to $1 range since 9/11? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mycgj/eli5what_are_the_reasons_as_to_why_the_oil_price/ | {
"a_id": [
"ccdqmzn",
"ccdqppi",
"ccds60n",
"ccdunhs"
],
"score": [
5,
3,
3,
2
],
"text": [
"The specifics about why gas prices go up can be better explained by others, but this chart shows gas prices adjusted for inflation:\n\n_URL_0_\n\nIt seems like the climb started closer to 1999 than 2001, but asking why it hasn't gone back done since then is a great question.",
"two big reasons. China and India are industrializing at an amazing rate, using more petroleum for industry and also for autos as the middle class moves up. But the biggest reason is that people will gladly pay a great deal more for gas. SInce they can sell all they want at $3.50/gal why would they lower the price to $1? ",
"Because they've discovered that demand will sustain $3.00+ conditions. If they thought they could get away with anything higher, they would. And, they will soon.\n\nIf you were selling lemonade (and were evil) you rely on lemons. If you're grocer was cheating with his produce supplier's wife, there might be concern in your community about the availability of lemons. With summer approaching, people would be very willing to pay $2 for a lemonade they paid $1 for last year. Eventually your grocer would find a new fruit source and lemon supply would return. But, people are now used to paying $2 a glass, so....... yeah.",
"Because oil companies are greedy. Record high profits while charging record high prices, but the oil companies will tell you that the price of gas has nothing to do with their profits."
]
} | [] | [] | [
[
"http://inflationdata.com/Inflation/images/charts/Oil/Gasoline_inflation_chart.htm"
],
[],
[],
[]
] |
||
4dh5cd | how exactly do people avoid taxes using shell companies? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4dh5cd/eli5_how_exactly_do_people_avoid_taxes_using/ | {
"a_id": [
"d1qujoc",
"d1qv736"
],
"score": [
5,
2
],
"text": [
"Let's say you own a pretty profitable business in the US but you're tired of paying taxes. First, you make a shell company where there are lax regulations and low taxes. Then you transfer the assets that your US company has to the shell company, in name at least. You continue to use those assets in the US to make money and do business, but all the money technically belongs to your shell company. Since your shell company is outside of the US, it doesn't pay US taxes. \n\nThe tricky part is being able to use assets outside of the US to do business in the US without having to keep the money in the US. There are different ways to get around this. For example, a tech company can transfer all of its patents to its shell company and then the US company can lease them back under terms where money made from their sale belongs to the shell company. ",
"You transfer assets out of the real company, to make it look like it didn't make any money, and put them in the shell company.\n\nThen the shell company doesn't pay taxes. You could just not file, and shut it down before you get caught. \n\nOr you could put the shell company in another country, and make that money and your association with it hard to trace."
]
} | [] | [] | [
[],
[]
] |
||
2jqt9h | pigs are considered fairly intelligent animals. why are people who abhor eating dogs, cats, horses and whales for moral reasons fine with eating pork? | I'm looking for a better explanation than "Because bacon" | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jqt9h/eli5pigs_are_considered_fairly_intelligent/ | {
"a_id": [
"cle8nal",
"cledyz0"
],
"score": [
14,
3
],
"text": [
"Because pigs rarely have a use outside of their use as food. Sometimes they are bred to hunt for truffles and other fungus/plants, but aside from that, their characteristics make them ideal as a food source.\n\n* Grow quickly\n* Eat anything\n* Don't require much space\n* Gain lots of meat in a small amount of time\n\nThat second part \"Eat anything\" is actually the reason why Jews and Muslims don't eat pork. Pigs were scavengers in the areas where Abrahamic faiths are indigenous to, and as such they would eat the garbage and therefore were considered unclean, despite the fact that they are remarkably hygienic animals.\n\nWhereas while dogs, cats and horses share some of these traits, they generally are more viable to be used for other means.\n\nDogs\n\n* Hunting companions\n* Shepherd companions\n* Security/protection\n* Don't grow as quickly\n* Not as much of a varied diet\n\nCats are almost solely kept around as mousers, they would eat mice, rats, any rodent really, as well as insects and other small animals. This would result in less rats, mice, etc. to carry disease or get into food stores, therefore more food for us humans, and less disease. They were also very good when kept in a home in order to know when something was to happen as they can sense things we can't.\n\nHorses have been used for travel, as beasts of burden and symbols of wealth and power for thousands of years. They took a while to grow and didn't produce a large enough amount of meat compared to what it took to raise them for them to be a viable mass food source. They are a delicacy in some countries, and even then they take in horses that are lame, or died in accidents to be butchered.\n\nWe don't eat whales because it's a pain to get them, they are almost extinct and serve a massive role in the oceans' ecosystems.",
"You're really not going to find much of a good reason for why we see some animals as deserving of rights and protection and some as being hardly better than inanimate objects. I'd say the average cow isn't any dumber or less able to feel pain or understand their captivity than the average dog, but if that means never eating beef again, you'll find that a majority of people won't find this reasoning convincing enough. \n\nSame with whales. Whales are extremely intelligent and some are forced to live in tiny pools and do tricks for our entertainment. Probably the only reason there's such a robust movement to protect whales is because they're endangered. If whales were common like cows are, we'd probably have much less of a problem killing them.\n\nUltimately, there are only two logically consistent positions: veganism or accepting that there's absolutely no moral reason not to kill animals for any reason. I'm not even a vegan myself. I'm just saying, anyone who can justify eating meat but also opposing some forms of animal cruelty is tricking themselves. "
]
} | [] | [] | [
[],
[]
] |
|
c7aij8 | why stab wounds in movies appear to be deadlier than gunshot wounds (at least in movies) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c7aij8/eli5_why_stab_wounds_in_movies_appear_to_be/ | {
"a_id": [
"ese4i0h",
"ese61jk",
"ese6ntc",
"esebqze",
"esegryb"
],
"score": [
40,
2,
13,
10,
4
],
"text": [
"It's all about what's convenient for the story. Bad guys get shot and they are instantly dead. Good guys get shot and they can run a marathon.\n\nThere is no consistent logic even within the same movie. As long as it doesn't break the suspension if disbelief, writers and directors do what moves the story in the direction they like",
"They both obey the same laws:\n\nIf it hits an artery/heart, you're dead 99% of the time\n\nIf it hits a major organ, there's a high chance of death unless treated immediately. \n\nIt's just stabbing is more accurate than shooting.",
"Knife fights and stabbing are often more \"personal\" conflicts that are supposed to cause more tension emotional distress in the viewer. In keeping with this perception of raised stakes, they will often be depicted as fatal.",
"It depends on a lot of factors, but personally I'd MUCH rather take my chances getting stabbed than shot. Knives make much cleaner wounds with a lot less energy than bullets, are less likely to shatter bone and tear tissues beyond what you see with the entry wound, and have inherently limited depth depending on the blade. Others have commented how in film and TV, the relative deadliness of a knife vs gun wound has much more to do with the demands of the plot than what happens in real life. I find it very believable that gunshot wounds to the abdomen are deadlier than stab wounds - gunshots are more likely to damage one of the several huge arteries and veins in the abdomen, relative to a knife, and the damage they do is more difficult to repair in the trauma bay.\n\n & #x200B;\n\nIf YOU get stabbed, the absolute number 1 most important thing to do is STOP THE BLEEDING. Blood loss is the most common cause of immediate death from stab wounds, bar none - especially if the stab is in the gut. Cutting into intestines can kill from infection, but this takes days to weeks; dying from blood loss due to a major artery in the abdomen can take seconds. Other targets - the liver, pancreas, kidneys, stomach, spleen - all have really significant risks when damaged, but none as immediate and high-stakes as blood loss (and, for many of them - i.e. the spleen, kidneys and liver - blood loss IS one of those risks, as they bleed profusely when damaged). Find the hole where blood is coming out, and apply as much direct pressure to it as you can to stop it until EMTs get there. This is why one important rule is to never remove the object that caused the wound, if you can avoid it - the knife or whatever could be helping to stop blood coming out of the vein or artery it's stuck in.",
"I have been an ER nurse for 25 years and one thing I have learned in that time is that if a woman comes at you with a knife, run! She will kill you! \n\nI have seen far too many deaths from stab wounds compared to gun shots. The majority of them have severed aortas, pulmonary arteries, superior vena cava, etc. Most gun shot wounds tend to hit extremities or in the back (which causes other issues). \n\nAlmost every stabbing victim I have treated was attacked by a woman. I had a guy in the other day who was stabbed by a woman. She severed his pulmonary artery. He died in the trauma room. We got him back. He was in for a follow up because he thought his wound was infected. \n\nMaybe I should put this in /r/life tips but if you have pissed off a woman enough that she comes at you with a knife, run like hell, your life depends on it."
]
} | [] | [] | [
[],
[],
[],
[],
[]
] |
||
19hqkd | how does the susan g komen foundation steal so much money without anybody getting upset about it? | *braces for grammar-impact for ending with a preposition*
More specifically, what were the numbers involved in the scandal? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/19hqkd/eli5_how_does_the_susan_g_komen_foundation_steal/ | {
"a_id": [
"c8o4o9j",
"c8o4ykd"
],
"score": [
2,
2
],
"text": [
"people stop caring after they make their donation. No one ever cares where the money goes after they give it, they just give it to feel good about themselves, not to actually do any real good. It is all about perception, and perception is reality.",
"\"It\" is a pronoun, not a preposition.\n\nAlso, \"don't end questions with a preposition\" is a questionable rule at best, and just plain made up at worst, depending on which grammarians you ask."
]
} | [] | [] | [
[],
[]
] |
|
19c682 | why do people want programming taught in elementary/high schools? | I know absolutely nothing about programming.
EDIT: I'm marking this as answered. Thanks to everyone who replied! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/19c682/eli5_why_do_people_want_programming_taught_in/ | {
"a_id": [
"c8monuf",
"c8movm3",
"c8mr457",
"c8mrmd3",
"c8ms032",
"c8ms8i1",
"c8msynv",
"c8msz8m",
"c8mszo4",
"c8mt14u",
"c8mtou0",
"c8mtvth",
"c8mtzpq",
"c8muhi2",
"c8muoof",
"c8mup5l",
"c8mv9zr"
],
"score": [
114,
16,
9,
4,
2,
11,
8,
2,
4,
3,
2,
15,
2,
2,
3,
3,
3
],
"text": [
"Because it's a skill which has lots of real-world use, and which, like many skills, is easier to teach to children than adults.",
"It promotes good thinking habits. ",
"It's a good way to teach someone a different method of logical reasoning. Same reason they teach higher level math. Are you REALLY going to need advanced algebra in your daily life? Nope! \n\nAre you going to learn how to program your own operating system in high school? nah!\n\nI think of programming like another universe. The laws are different. You have to learn the laws and learn to think in that universe. \n\nFor instance, an exclusive or: _URL_0_\n\nXOR as it's called. \"This OR that but not both\". \"Do you have an apple or an orange\". note the question is asking in the singular. Both isn't an acceptable answer and neither is none. The answer can only be apple or orange. ",
"Been advocating this too.\n\n1) As a proxy for learning problem solving and overcoming setbacks in a logical, highly teachable way that's full of immediate feedback. Mastering those two things can mean the difference between seeing the world as a place full of solvable problems or as an incomprehensible pile of magic and mess. \n\n2) If you get good at it and enjoy it, then do it professionally, you're less likely to ever have to worry about a job (or being trapped in a job) than many other people. \n",
"It should be an elective, but I see no qualms offering it to students. It'll give a 13 year a head start in a field they might be interested in, and a reason to stay in school. ",
"I took computer programming in high school as an alternative to calculus.\n\nIt's a challenge getting through my daily life without knowing calculus, but I cope the best I can. With the money I make as a computer programmer.",
"Programming teaches people that if something is wrong, 99% of the time 1) it was the coder's fault, 2) it's due to lack of attention to details, and 3) there is a logical (and often elegant) solution. It teaches that complex systems can be broken down into smaller parts. It forces objectivity and reasoned analysis. Magical thinking is punished.\n\nThe learning experiences gained through programming are valuable in many disciplines and life in general.",
"Critical thinking and problem solving.",
"A computer litterate nation is better than an illiterate one. ",
"_URL_1_\n\nHere's a nice little video by _URL_0_ that addresses that very issue. It features people like Bill Gates, Mark Zuckerberg and _URL_2_.",
"Programming is a subset of computer skills that are required in the real world. Computers are everywhere. I'm a computer science (programming) major in college that works for IT (fixing broken computers). The lack of understanding by even many university professors is incredible. The current system for learning to computer is poor, at best.\n\nSecondly, programming doesn't just mean, \"oh, look at that nerd writing Java programs\". Excel allows for many commands, and is a major tool used by almost every company at many levels. Knowing how to use this program more effectively is a huge asset.\n\nFor most things people use, individuals take the time to educate themselves about the product at some level. I drive a car- I know I need to get my oil changed regularly and which gas to get and the difference between brands and engine types. Not at the level of a mechanic, but I know enough to have a high level conversation with one to discuss my issues. I talk to many people about computers, and ask if they've \"installed drivers\" or to \"find their ip address\" (relatively simple tasks), and they don't even know where to look.\n\nWith as prevalent as computers are today (everywhere), people just need to be more educated, early, about computers in a manner that just isn't taught today. Programming is one aspect of that.",
"One of the biggest reasons people want programming taught is because programming isn't exactly what you think it is. Programming is problem solving. I work with visual studio mostly and there is a reason that the name we use for a new project is a *\"Solution\"*.\n\nEverything I do is a problem. You come to me and say you want a website. Before I would think \"Ok so I need html, uh I need a domain\" etc etc. As I got more into programming and better at it I learned all I was doing was solving problems. So when you say you want a website what you are actually saying is that you have a problem. The nature and solution to your problem is my skill. You don't want a website you want me to build something to fit a need you have. The problem is that you do not have a tool to get what you want, so I build you the tool that gives you what you want.\n\nSo I will begin asking you questions. They will seem strange. I won't ask about color schemes or trends yet. I need to figure out what you want and you can't tell me that. You don't know. Thats what I do. You tell me the vague goal you want and I probe and prod and solve **you**, to solve your problem.\n\nCode and the languages themselves are just my tools. I am skilled with them and understand them. But the difference between someone who knows how to code and what I would call a programmer is the same between a carpenter and a person who owns a hammer. You do not pay for my tools. You pay for my mind and I use my tools to solve your problem, the same as you pay a carpenter for how he uses the tool, not how long he's been using the tool.\n\nThe reason that programming is so much better at teaching problem solving is because of a concept known as abstraction. Abstraction is confusing because it's used for a lot of things. We associate it with so many concepts it's tough to know if you don't look for it. But abstraction is easy. You already know it. If I showed you a desk chair and asked you to tell me what it was you could do it easily. Now if I showed you a recliner and asked you what it was; again no problem. Now if I asked you what both were then you would tell me they were both chairs. That's it right there. You can tell me that they are clearly different and yet the same. So if you had to tell me about both chairs we can figure out what they have in common (back, bottom, support, seat, material) and what was different (recliner part, wheels). Abstraction is just saying. These things all fit into a group I call this. So desk chair is a chair which is a piece of furniture.\n\nThis is what is needed in problem solving. You have to understand incredibly in depth what makes things the same and what makes them different. You have to be able to take something real (a deskchair) and understand what is abstract about it and what is real (the chair is really made of leather and metal) and what is abstract (the name \"desk chair\") is abstract it could be called anything yet we need to understand how both of those concepts work in order to understand a chair.\n\nSo learning programming allows you to make connections and associations. Along with that it allows you to understand hierarchies and scopes of problems. It gives you language to express problems. So I can think and plain intelligently my approach to a solution because I have a way of expressing any problem. I can do it with anything. You have a social problem? I can deconstruct the components and give form to the problem. I can literally pull out all of the information and then provide any solution for you.\n\nProgramming just gives you access to that world. This magic box in front of you is capable of generating an almost infinite amount of imagery. Those pixels you are reading this with can be rearranged IN ANY WAY!! All you need to know is how to get them to do that. And you do that by learning to program. So it not only teaches you how to solve problems but gives you a virtual environment in which you can recreate and test and test and test. You can do anything that your computer can process.\n\n**TL;DR Why the hell would you not want to know how to virtually become a magician?**",
"Because if you understand how to code, you can basically do anything you can imagine. You will also learn that it's not hard.",
"It's more about learning logic than just making things pop up on a screen.",
"If you can program a solution method, you understand the problem. \n\nI firmly believe this is the way math should be taught. Repetition on an abstract idea doesn't really help. Learning good problem solving in a practical way does. That's why no-calculator tests always bothered me. Really? I'm going to be doing this level of math without one ever?\n\nWhen people talk about programming, they don't necessarily mean graphics, web, all of that - that kind of practical programming isn't necessary for everyone. They mean using programs that can ready simple commands to solve simple programs, like Matlab. ",
"You know people who 'aren't good at computers' and how they generally suck at a lot of other things too? Well by the time kids today are job age tomorrow, they's gonna need it. \n\n**TLDR:** The world is only getting more and more computery, son. You don't wanna end up like lazy uncle Joe.",
" > I know absolutely nothing about programming.\n\nI feel like you answered your own question.\n\nComputer literacy is important. Browse r/talesfromtechsupport and see the stupidity that those people have to deal with on a daily basis. If you're computer literate, your productivity shoots up tremendously, since there are all these computer programs that do just that! Besides, since computers are so useful, *you're* only useful if you know how to use them. Even a cashier needs to be able to handle numbers and computers. Nearly every facet of our lives is centered on, or at least informed by, computers.\n\nIf being able to use computers is like reading, then programming is like writing. Even more than that, programming is a language you use to solve problems. And just like with English, if you can *think* in programming, your universe is much bigger. Would you be able to think of, say, the US Constitution without language? It's a document, but it's also the framework of a government. Maybe you can imagine a picture of the US Constitution, and maybe comprehend some of what it means, but without language, you won't get very far! Programming is like that, but it's a different language for a different problem space.\n\nThe thing is, math is *abstract*. You learn how to add and divide, but for what? What good is factoring polynomials? It's easy to treat math as something you have to do for school that you never want to see again. Programming is something with obvious applications *right now*, and it's fun, too, since you get to build and create things. Programming *forces* you to think logically and to pay very careful attention to details, because otherwise, things just don't work. Programming is the culmination of what our logical-leaning education is *supposed* to be.\n\nAnd, very importantly, jobs require programming. Lots of them. If you're a bad programmer, that's OK; at least you know the basics and can understand what's going on if you need to. If you don't program at all, though, a large share of the world is just unavailable to you. The barriers are just too high when you don't program at all."
]
} | [] | [] | [
[],
[],
[
"http://www.klopfenstein.net/public/Uploads/lorenz/genetic_algorithms/xor_truth_table.png"
],
[],
[],
[],
[],
[],
[],
[
"code.org",
"http://www.youtube.com/watch?v=tVtvCAYBhTg",
"Will.i.am"
],
[],
[],
[],
[],
[],
[],
[]
] |
|
5vrzqh | why do people in the americas greet eachother with one kiss on the cheek while in europe they greet eachother with two kisses on each cheek? | I am aware not every nation in either continent does this, and I am also aware that it depends on region. It gets the point across. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5vrzqh/eli5_why_do_people_in_the_americas_greet/ | {
"a_id": [
"de4cuzm",
"de4di90"
],
"score": [
6,
3
],
"text": [
"Americans do not, on average, kiss each other on the cheek when meeting. Since the most common is zero, one seems like plenty.\n\nIn a culture where kissing on the cheek is common, two does not seem like an excess. ",
"I do not greet people with one kiss on the cheek, and I'd think you were weird if you were also an American and greeted me with a kiss on the cheek.\n\nA handshake will do if it's formal. A hug if you're family or a close friend. A simple vocal greeting will do just fine otherwise."
]
} | [] | [] | [
[],
[]
] |
|
b5w9aw | is there any difference between getting injections(of vitamins,medicine etc.) directly into your veins or into your muscle(most commonly butt muscle)? | Simply,I had the same stuff injected to me both ways and I wish to know what's the difference? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b5w9aw/eli5_is_there_any_difference_between_getting/ | {
"a_id": [
"ejgbxu9"
],
"score": [
3
],
"text": [
"Some things, like vaccines, are best injected into muscles due to the way they are made and engineered to work.\n\nOthers are injected into veins for quick distribution. Because vaccines do not need to be so rapidly distributed they do not need to directly enter the bloodstream.\n\nAs to why they did both for you, it could be that you need some now and some long lasting treatment."
]
} | [] | [] | [
[]
] |
|
20v4jt | why is contact lens solution so friggin' expensive? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20v4jt/eli5_why_is_contact_lens_solution_so_friggin/ | {
"a_id": [
"cg73k97",
"cg75ril"
],
"score": [
2,
3
],
"text": [
"Because people need it and will buy it at any price. Like gas.",
"It's a sterile product that people are putting in their eyes. Lots of liability if someone gets an infection."
]
} | [] | [] | [
[],
[]
] |
||
1jwcez | how do "non-profit" organizations have some of the highest paying internships / job positions? | A friend of mine just told me he was offered a job with a non for profit making about 65K a year, and I didn't feel comfortable asking how the hell...? If they're making no profit's, is it all donations? Thanks | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1jwcez/eli5how_do_nonprofit_organizations_have_some_of/ | {
"a_id": [
"cbix590",
"cbix8px"
],
"score": [
12,
5
],
"text": [
"The company itself doesn't post a profit, meaning that any money it gets over its budget/operating cost (including employee salaries) must be given away/not used for company benefit. While it may seem counter-intuitive, non-profits do need to maintain competitive pay rates to attract talent necessary to maintain an effective business.",
"Non-profit just means that instead of the company paying out profits to employees (in the form of bonuses) or to investors (e.g. through dividends) as regular corporations do, non-profit organizations instead re-invest all the 'profit' they make back into the company to improve its products and services. It basically just means the organization is committed to only spend excess money on advancing the corporation in meeting its long-term goals and mission statement. Not for profits are required to comply with a number of government regulations which require them to be very open and transparent about their 'business practices' and finances to ensure they are not abusing their non-profit status.\n\nDo note that non-profit organizations are still allowed to pay salaries like normal companies. All that matters is that whatever is left over after covering expenses (including but not limited to salary-pay), must then be reinvested back into the corporation. So they can still have salaries, they just can't pay bonuses that are dependent on how much money the organization makes that year.\n\nIt's also important to distinguish between non-profit and charity. A charity is simply a type of non-profit organization that does free work (e.g. helping the poor) and is funded primarily through donations. There are however other non-profit organizations that look and act just like companies and offer regular products and services for a fee, it's just that they don't take home the profits in the form of bonuses and dividends."
]
} | [] | [] | [
[],
[]
] |
|
5imzfv | why do elderly people die from simple falls? | I'm not referring to directly traumatic falls here, like if they fall and hit their head and suffer brain damage.
Why do elderly people die from falling (directly, i.e. the fall causes lethal health complications, or indirectly, i.e. they are injured in some other way and die in the course of trying to treat that injury), when an identical fall would barely even injure someone younger?
I know that when you get old your bones become significantly more porous and it becomes easier to *break* them, but I'm having trouble making a connection between things like Grandma Betsy falling and bruising her hip or spraining her ankle on Day 1, and then subsequently passing away on Day 4. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5imzfv/eli5_why_do_elderly_people_die_from_simple_falls/ | {
"a_id": [
"db9fv50",
"db9g1re",
"db9gcz0",
"db9h6a1"
],
"score": [
2,
3,
5,
3
],
"text": [
"Healing wounds takes a lot of energy and resources for the body, and as a person gets older there's less to go around for normal processes if something does happen. Bones, muscles, and organs all get weaker and less effective at their jobs, just like in a mechanical system when parts fail and degrade.",
"A hip repair is a big fucking surgery. \n\nA lot of energy goes into healing that type of injury. \n\nOlder bodies simply don't work as well as younger bodies. \n\nYou could have internal bleeding. Infection. Organ failure from shock. You name it. \n\n",
" > when an identical fall would barely even injure someone younger?\n\nBecause often it is not an identical fall.\n\nA healthy person will likely have the strength, reflexes, balance, and agility to partially recover, and minimize the damage of fall. You put a hand out, aim for something soft, or twist so you land on your side or butt. \n\nAn elderly person taking the same fall might not be able to any of these things, and wind up falling harder, landing on a more vulnerable area, and hurting something vital.",
"Advanced Age + Fall = Death\n\nMortality comes from:\n\n1) deadly blood clots (as a direct complication of any broken bones) which can then travel around the body (think heart, brain and lungs) and cause further fatal damage like heart attacks, strokes\n2) deadly hospital-related infections while undergoing treatment for the fall\n\nThere are also complications from de-conditioning from being immobilized after the fall, which leads to skin break down from being bed-bound, and overall failure to recover.\n\nElderly people have less \"reserve\" than younger people, and it can be very hard to bounce back from a serious fall. This lack of reserve means they have less strength/flexibility, tend to be malnourished, and perhaps have weaker immune responses to begin with when they fall. \n\nYou'd be amazed by how deadly even a ground-level fall can be for a patient."
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
rfnu0 | how does a on-time pad work? | _URL_0_
One time pad* Sorry! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/rfnu0/eli5_how_does_a_ontime_pad_work/ | {
"a_id": [
"c45g9rd"
],
"score": [
2
],
"text": [
"All codes work by changing some piece of information. Because of the change it is hard to tell what the original information was. For instance if I change some word into \"xxr\" what was the original word? \n\nWell a one time pad is a way of changing information that never repeats any pattern,, that means you can never predict how information is or was changed. That means you can never decode \"xxr\" because you can never guess what I did and I will never do it again, I did it \"one time\"."
]
} | [] | [
"http://en.wikipedia.org/wiki/One-time_pad"
] | [
[]
] |
|
2g8bnn | why airline frequent flyer programs have been made so difficult? | Why the airlines don't reward points automatically? I can understand that some may want to register the points for another airline in the same alliance, but why not those airlines not in any alliance do it always automatically?
Why I can't register reward points right after I've used my ticket? Why do I have to wait for like a week in order to register? However, if I show my loyalty card at check-in desk, the points get registered. Sometimes I forget to show my card, but my card is never asked, why? Grocery stores always ask my card.
I flew with a new company and then tried to register the points. However, this company didn't allow to register afterwards like all other airlines. They didn't notify me at any point about this. It's like they don't even want me to register the points. Why?
I was able to collect enough points to upgrade the program. Then in an airport at the service desk I asked them to get me a new card. Their reaction was a bit rude "we can't help you". This is just a single case, but the feeling I get overall is that the airlines don't seem to care about their customers regarding the loyalty programs. Why?
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2g8bnn/eli5_why_airline_frequent_flyer_programs_have/ | {
"a_id": [
"ckgl1hk"
],
"score": [
5
],
"text": [
"Because the airlines benefit from the impression that they have the program, but do not benefit from people using it."
]
} | [] | [] | [
[]
] |
|
6pwn7n | how do telescopes that capture images very far away (hundreds of light years) get a good sharp shot when you know that the earth rotates slowly | Because you're looking at a very tiny spot in space very far away, the rotation of the earth would cause it to move out of frame in just a second wouldn't it? Do telescopes move with it when looking at that point? Or are pictures from that far away taken with the hubble telescope that doesn't rotate with the earth (of course it orbits but still pointed in one direction) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6pwn7n/eli5_how_do_telescopes_that_capture_images_very/ | {
"a_id": [
"dkspldr",
"dksqew5"
],
"score": [
5,
2
],
"text": [
"The telescopes are mounted on motors that move it to compensate for the rotation of the earth. This is true for even moderately expensive personal telescopes.",
"Extremely high-quality images are taken with orbital telescopes. Even if you compensate for Earth's motion, the atmosphere imposes a limit on the quality of pictures we can take from Earth's surface.\n\nBut yes, the best telescopes we do have on the surface of Earth compensate for its motion. "
]
} | [] | [] | [
[],
[]
] |
|
1n5owg | i've been diagnosed with tenitus (loud ringing in the ears) what's making my brain generate that noise? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1n5owg/eli5_ive_been_diagnosed_with_tenitus_loud_ringing/ | {
"a_id": [
"ccfmfiz",
"ccfmjku"
],
"score": [
8,
3
],
"text": [
"You didn't ask the person who diagnosed you?\n\nAlso, it's tinnitus.",
"I'm also suprised you didn't ask the diagnoser.\n\nThe brain is interpreting something and producing the ringing. There are several ways this can happen. Damage to the ear drum, damage to the hairs in the cochlea, damage to the nerves going to the hearing processing centers of the brain, damage of the processing centers themselves, damage to the small bones of the ears...\n\nBut it just is what it is now. I play music at night, seems to help. And zzzquil. OMG awesome stuff."
]
} | [] | [] | [
[],
[]
] |
||
11c3gd | musical intervals (with emphasis on guitar) | I took elementary music theory in college, but it's been really hard for me to conceptualize the idea of understanding musical intervals and how they work.
Does anyone have a thorough understanding and can help me out? I'm not a dumb kid - I'm just not spacial AT ALL and need to see this stuff happening, or have it explained to me, to understand it.
(I've read stuff like this: _URL_0_ and I just get lost because I don't have a rote grasp of major/minor scales yet. I know how to derive them, but I can't seem to memorize them). | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/11c3gd/eli5_musical_intervals_with_emphasis_on_guitar/ | {
"a_id": [
"c6l5p6v"
],
"score": [
2
],
"text": [
"The simplest way to describe an interval is that it's the number of semitones between two notes. There are 12 semitones in an octave and each one has a special name. Here's what that would look like using a C chromatic scale:\n\n* 12. Octave (C)\n* 11. Major 7th (B)\n* 10. Minor 7th (Bb)\n* 9. Major 6th (A)\n* 8. Minor 6th (Ab)\n* 7. Perfect 5th (G)\n* 6. Tritone (Gb)\n* 5. Perfect 4th (F)\n* 4. Major 3rd (E)\n* 3. Minor 3rd (Eb)\n* 2. Major 2nd (D)\n* 1. Minor 2nd (Db)\n* 0. Root (C)\n\nYou might notice that the intervals labelled \"major\" match up with the notes of the major scale, and the ones labelled \"minor\" are in the minor scale (except for the minor 2nd, which gets no love). The perfect intervals are the most harmonious intervals, and appear in both scales, while the \"tritone\" is a special interval that is extremely dissonant and is in neither scale. For intervals larger than an octave, the cycle repeats again (starting with minor 9th because the octave is the 8th note).\n\nEDIT: Since you asked for an emphasis on guitar, I made you [this diagram](_URL_0_) as an illustration. If you're playing in C (root note 3rd fret on A), the number on the diagram matches up with the interval on the list."
]
} | [] | [
"http://audio.tutsplus.com/tutorials/music-theory/music-theory-intervals-and-how-to-derive-them/"
] | [
[
"http://imgur.com/CLQhw"
]
] |
|
4y3laa | when people that are lactose intolerant eat or drink dairy, what exactly is happening inside their stomach when diarrhea occurs? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4y3laa/eli5_when_people_that_are_lactose_intolerant_eat/ | {
"a_id": [
"d6kqvet",
"d6kwnjr"
],
"score": [
8,
2
],
"text": [
"So lactose intolerance happens when someone's body does not create enough [lactase](_URL_1_). Lactase is an [enzyme](_URL_4_) that would break down [lactose](_URL_3_), the unique sugar component of milk, into sugar that our bodies can use for energy. Lactose intolerant people have issues with breaking down the lactose in their small intestines, which is a part of the digestive tract after the stomach that is responsible for absorbing a great amount of the nutritional stuff that goes through our body. So when a lactose passes through the small intestine and into the large intestine it removes water from the colon lining (through [osmosis](_URL_0_?)) and causes excessive runny poops. Much of the more complicated answer involves [microbial communities](_URL_2_).\n\nEdit: added a bunch of links in case you get carried away with this question and want to learn more but appreciate quick links. Additionally, did you know in some Asian communities over 90% of individuals experience some level of lactose intolerance? This fun fact also brings up the important distinction that not all lactose intolerance is equal. ",
"extra credit: why/how is it possible to overcome this allergy over time? "
]
} | [] | [] | [
[
"https://www.reddit.com/r/explainlikeimfive/comments/j2egm/can_someone_please_explain_osmosis/",
"https://en.wikipedia.org/wiki/Lactase",
"http://www.medicinenet.com/lactose_intolerance/page2.htm",
"https://en.wikipedia.org/wiki/Lactose",
"https://en.wikipedia.org/wiki/Enzyme"
],
[]
] |
|
3zvlf7 | is modern industry able to make cheap paper not from wood? | E.g. from synthetic polymers. Surely, if they are not made from wood themselves :)
If not, what are main bottlenecks? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3zvlf7/eli5_is_modern_industry_able_to_make_cheap_paper/ | {
"a_id": [
"cypbbsz",
"cypc34p",
"cypcpkt",
"cypcwda"
],
"score": [
4,
5,
2,
2
],
"text": [
"Paper gets made from fibres such as linen, too, and a lot of paper is recycled. It would come down to cost, whether synthetic polymers would do the job and be cost-effective (i.e. cheaper).\n\nTyvek® has many of the properties of paper - e.g, it's flexible and you can write on it - but it's more expensive. ",
"The question is though... What's wrong with paper from wood? The paper industry plants as many trees as they cut down nowadays, to make sure they will be able to still make paper in the future. It's not like massive forests are disappearing because of paper.",
"Even if we could make paper cheaper, faster, and better from synthetic sources, we may not want to. Paper is biodegradable, recyclable, and comes from an infinitely renewable source (trees and other plants). The most likely alt would be some sort of petroleum product, which is non-renewable and often non-biodegradable.",
"Really there just isn't a good alternative that's biodegradable and cheap. Also can't believe no one has commented talking about hemp paper haha"
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
2pqlq3 | how hard would it be to just unplug all of n. korea from the internet? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2pqlq3/eli5_how_hard_would_it_be_to_just_unplug_all_of_n/ | {
"a_id": [
"cmz42nq",
"cmz45od",
"cmz70rw"
],
"score": [
10,
4,
3
],
"text": [
"Not that hard but China's assistance would be a prerequisite. But that goes against all ethical reasoning in that the internet should be available to all.\n\nEven if you did, the chances are that the Sony hack was conducted from outside N. Korea. ",
"Technically easy, they're decades behind in infrastructure, and I doubt they have many trunk lines or much redundancy. I'd actually be surprised if they had more than one or two physical lines. Blocking satellite access would be a lot harder, of course.\n\nBut it wouldn't have the effect you want, because it won't stop them from \"hacking\" sony or whatever they feel like next time. It's pretty likely that attack wasn't even done from within north korea, and virtually certain they relied on non koreans anyways.",
"It's pretty hard to unplug a country that doesn't have electricity. North Korea's hackers work all over the world to cover their tracks and utilize free wifi hotspots that they don't have in Pyongyang."
]
} | [] | [] | [
[],
[],
[]
] |
||
2cn679 | why do analog tv broadcasts still exist in the us? | I thought all US TV broad casts were required to be digital for some time now.
Doing a channel scan on my TV just today it ended up detecting 3 analog stations along side all the digital ones. The analog ones were all fairly weak and all spanish television.
Isn't it an FCC requirement any TV broad cast be digital? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2cn679/eli5_why_do_analog_tv_broadcasts_still_exist_in/ | {
"a_id": [
"cjh4ghb"
],
"score": [
4
],
"text": [
"Low Power TV stations are still allowed to transmit in analog in the United States. The current deadline for them to convert to digital is Sept 1, 2015.\n\n_URL_0_"
]
} | [] | [] | [
[
"http://www.fcc.gov/guides/low-power-television-lptv-service"
]
] |
|
4touns | how do single cylinder engines work? | . | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4touns/eli5_how_do_single_cylinder_engines_work/ | {
"a_id": [
"d5j1boh",
"d5j1eee",
"d5j46u8",
"d5j51yn"
],
"score": [
2,
3,
4,
2
],
"text": [
"When the piston goes up into the cylinder, it squeezes a fuel-air combination, and when it gets to a \"sweet\" spot, the spark plug at the top of the cylinder fires, igniting (somewhat explosively) the compressed fuel-air mix. This drives the cylinder down. \nA rod on the bottom of the piston is non-rigidly attached to a drive shaft. The rod is allowed to move back and forth as well as up and down as it drives the shaft. When it gets to the bottom, the shaft keeps on spinning, and moves the rod a little more in the direction it had been traveling. As the shaft continues its rotation, this pushes the piston back up into the cylinder again to start the whole deal over again. ",
"A single-cylinder engine works just the same as other engines; you compress a working fluid with oxidizer in it (i.e. air), and add fuel which then combusts, raising the pressure and temperature of the working fluid in the cylinder to high levels. You then take advantage of that high pressure to drive a piston downwards, which is connected to an output shaft that can be used to drive something. In the cylinder, after expansion, the exhaust gas is expelled, and new fresh air enters the cylinder to prepare for the next round of combustion. Suck, squeeze, bang, blow, with all 4 steps repeating dozens to hundreds of times every second.\n\nThe only difference with multiple cylinders is that they work together on the same output shaft.",
"All engines have a flywheel of some sort to smooth out their power output. In a four-stroke engine with less than four cylinders or a two-stroke engine with only one, the flywheel's inertia is the only thing turning the engine when there isn't a power stroke occurring in one of the cylinders.",
"I assume you have a basic understanding of cylinders, so I'm just going to answer the single cylinder question with a very simple example:\n\nImagine those elliptical machines at the gym. They actually function pretty similar to cylinders. You can just use one leg if you time your pushes correctly. Here is an example: _URL_0_"
]
} | [] | [] | [
[],
[],
[],
[
"https://www.youtube.com/watch?v=pnICAoZcFUE"
]
] |
|
1sycin | why at rock concerts and gigs is it always impossible to get the sound of the vocals to sound clear over the rest of the band? | I was in a band or two when I was younger and never once did a gig where the vocals were clear, even with decent P.A. systems. Even at professional concerts i.e. Frank Ocean, a lot of songs I found I couldn't hear the vocals clearly over the instrumentals. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1sycin/eli5_why_at_rock_concerts_and_gigs_is_it_always/ | {
"a_id": [
"ce2gdrr",
"ce2gnhd",
"ce2ibdl",
"ce2k0fd"
],
"score": [
5,
8,
3,
4
],
"text": [
"A public address system system is not a sound system. A professional sound engineer makes all the difference.",
"It's all about the sound engineer and the equipment they use. A shitty engineer won't get it right but the good ones will. Also depends where you are sitting/standing. ",
"the human voice is a really difficult thing to capture. Unlike instruments, it doesnt have a definite frequency or volume. This means a sound engineer has to constantly be adjusting the mix to bring the vocals out. They try to combat it with compression to regulate the volume, but it still shifts frequency, and gets muddied with the other instruments.",
"Three reasons. First, the guitars are always up too damn loud. Second, many smaller venues don't have adequate systems because that costs money. Third, many sound guys don't really care about their jobs in smaller places. Believe me, when you find a small venue with an adequate system and an engineer who cares, you can tell pretty quickly. "
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
1xqrgk | why should we care that we created nuclear fusion? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1xqrgk/eli5_why_should_we_care_that_we_created_nuclear/ | {
"a_id": [
"cfdrxbw"
],
"score": [
3
],
"text": [
"As you might know, most of our energy comes from unsustainable and highly polluting fossil fuels. Wind, solar, hydro, and geothermal sources can't create enough energy to replace them. Nuclear fission power plants produce highly radioactive waste. So we need some large source of energy that has a readily available fuel, doesn't pollute, and can produce enough energy to sustain a developing world. One of the most likely sources is through nuclear fusion. The fuel is not too uncommon (it can be found in sea water), it doesn't leave radioactive waste like fission, and it can theoretically produce large amounts of energy. We have some technological hurdles to sustain the process and for it to generate more power than it consumes, but many scientists and engineers are confident that some time decades from now, it can effectively eliminate many of today's problems with generating energy."
]
} | [] | [] | [
[]
] |
||
496dte | how is pre-made frozen food at the grocery store less healthy than food you make yourself and then refrigerate? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/496dte/eli5how_is_premade_frozen_food_at_the_grocery/ | {
"a_id": [
"d0pelwx",
"d0peppw",
"d0pepz0",
"d0pequh"
],
"score": [
4,
11,
4,
2
],
"text": [
"It's not. However, making it yourself allows you to use healthier ingredients and actually choose what you eat.",
"It's not *necessarily* less healthy, depending on what you make at home. But, generally speaking, pre-made foods are often made with more salt, sugar, and/or fat than people usually use when they make their own food.",
"Generally, frozen, premade foods are made from ingredients that are processed. Processed foods, generally speaking, are shelf stabilized for longer shelf life and that means there are usually loaded with preservatives, which are not healthy. There are premade, frozen foods that are made with better ingredients. Just read the labels to find the better foods. If there are ingredients you can't pronounce, then you are looking at chemically stabilized foods. Those are the ones you should avoid. \n\nPremade foods like fried checken are one of the foods that are not necessarily unhealthy, unless they are actually fried instead of baked.\n\n",
"Some of those premade frozen meals have like 40% or more of the daily recommended amount of sodium. "
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
24qhyw | how do satellites orbiting the earth get their orbits assigned to them, and how do they not hit into each other? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/24qhyw/eli5_how_do_satellites_orbiting_the_earth_get/ | {
"a_id": [
"ch9opbq",
"ch9orxa",
"ch9piwl",
"ch9rl91",
"ch9sxnu"
],
"score": [
6,
2,
2,
9,
2
],
"text": [
"Space agencies coordinate data on the tracking of the debris field above earth, to help avoid any sizable objects.\n\nBut mostly, the odds are just very low that you will hit anything. The surface of the earth is a big place, and the stuff we put into orbit, with a few exceptions, is relatively tiny. Picture a dust mote circling a beach ball.",
"I don't know about the orbit assigning part... but in my experience (at least with KSP) space is HUMONGOUS! You really have to try to get 2 objects even relatively close enough to each, and getting them close enough to actually hit is a miracle. Personally, it's not the satellites that pose a threat. A satellite is a single piece of machinery placed in orbit by people who know what they're doing (at least one would hope so). The most likely thing you would have to worry about in space in terms of collision is the thousands of pieces of debris from broken space junk/ejected pieces of rockets.",
"Much like how planets in our solar system orbit faster around the Sun when they are closer to the sun, satellites differ in orbit speed when placed at different attitudes from Earth.\n\nIf satellites are orbiting at different speeds only if they are at different altitudes. Since they are at different altitudes, they won't collide.\n\nTwo satellites placed in the same orbit attitude will orbit at the same speed. Since they never speed up or slow down normally, there is no chance of them hitting each other unless some other force acts on them.",
"Spent the last 25 years in the space business. It depends on the orbit. Geostationary communication satellites have their slots (e.g. longitude) assigned by the International Telecommunications Union (ITU) _URL_3_. If I want to put up a new comm sat I have to file with my national regulatory agency (for the US this is the Federal Communications Commission). The FCC then works with the ITU which may award a slot. The spacing is determined based on the type of communication service you want to offer and frequency you will be operating in. If satellites operating on the same frequencies get too close in longitude then they will cause interference into each others ground terminals (e.g. dishes). But two satellites at different frequencies can be in the same slot. Several geostationary operators operate multiple satellites in the same slot (most famously SES Astra having 6 in one slot _URL_1_). \n\nFor non-geo satellites, it's pretty much not an issue. Space is big and satellites are not. Until they do hit, such as the famous Iridium/Cosmos collision in 2009 _URL_2_.\n\nThe US Air Force Joint Space Operations Center (JSpOC) _URL_0_ does monitor all the objects in space and checks for potential collisions and notifies operators of potential collisions. Due to the limited accuracy of the orbital data it's difficult to predict with any certainty that an actual collision will occur, at best you can calculate a probability (usually around 1E-6 or smaller). \n",
"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."
]
} | [] | [] | [
[],
[],
[],
[
"http://www.vandenberg.af.mil/library/factsheets/factsheet.asp?id=12579",
"http://www.ses.com/fleet-coverage",
"http://en.wikipedia.org/wiki/2009_satellite_collision",
"www.itu.int"
],
[]
] |
||
9b0kgz | what's the difference between allegory and metaphor? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9b0kgz/eli5_whats_the_difference_between_allegory_and/ | {
"a_id": [
"e4zfu1p"
],
"score": [
3
],
"text": [
"The short version: An allegory is a type of metaphor.\n\n \nLonger version: A metaphor is a figure of speech that substitutes in a non-literal alternative to make an interesting point. Saying that \"his heart is a shattered vase\" is a metaphor, because a heart is definitely not a balloon, but it gives you an interesting image about how heartbroken that guy is. But it's not an allegory.\n\n \nAn allegory is specifically a story, poem, or image where the characters, places, or events are used as metaphors to make another point. So it's a little more fleshed out than the metaphor overhead. The Narnia books are seen to be allegorical, showing the foundations of Christianity (the creation of the world, a savior figure, a Last Judgement) in the form of a story about a magical world with talking lions and evil witches. Plato's Allegory of the Cave is about human understanding and learning, with humans trapped in a metaphorical cave staring at shadows on the wall, unable to understand what the greater world looks like when it's explained to them by someone who understands it better than them.\n\n & #x200B;\n\nSo an allegory is sort of a metaphor on a larger scale, while a metaphor can be small or large, not needing the structure of a larger work of art to be understood."
]
} | [] | [] | [
[]
] |
||
47muw7 | why do ants drop other ants off ledges? | Background info: My college has a bad ant problem upstairs.
I was sitting down watching the ants walk along the window sill, and noticed one was carrying another one that had wings toward the edge. The ant then proceeds to throw the ant with wings over the edge of the window sill- at least 3.5 feet to the floor, then walk away. Why would he have been thrown over the edge? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/47muw7/eli5_why_do_ants_drop_other_ants_off_ledges/ | {
"a_id": [
"d0e52dx",
"d0edl00"
],
"score": [
12,
2
],
"text": [
"Not sure if the carried ant was alive, but as i'm aware ants will remove ant-corpses from the vicinity of their colony so disease doesn't spread and doesn't attract predators. Perhaps that's why? ",
"Was it possibly a drone ant they was no longer needed? Once the Queen has done her thing the guys get tossed."
]
} | [] | [] | [
[],
[]
] |
|
8chk2l | why have we developed to sometimes hold our breath during tense situations? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8chk2l/eli5_why_have_we_developed_to_sometimes_hold_our/ | {
"a_id": [
"dxf22i9",
"dxf2ery",
"dxf4ump"
],
"score": [
3,
6,
6
],
"text": [
"Put simply, your brain puts all it's resources to getting you out of that situation, including the bit that controls your subconscious breathing",
"I'm going to do my best here. Deep breathing activates certain neurons in the brain that tell your body to relax. Holding your breath heightens that response a little. It also provides proprioceptive input, meaning it activates your muscles through that feeling of tension in your chest/abdomin. Similar to swaddling a baby, putting a thunder vest on a dog, or how a nice good hug is calming. ",
"I always assumed it was to better avoid predators and allow us to listen more carefully. This thread has been enlightening."
]
} | [] | [] | [
[],
[],
[]
] |
||
7wlq24 | why do surgeons need to wash their hands for an extend period of time when normal sanitizer already kill 99.9% of all bacteria | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7wlq24/eli5_why_do_surgeons_need_to_wash_their_hands_for/ | {
"a_id": [
"du1aanp",
"du1aikn",
"du1bkym",
"du1blpu",
"du1ci96",
"du1dhsk",
"du1dlei",
"du1f0h8",
"du1rsoy",
"du1vibc"
],
"score": [
22,
7,
155,
45,
2,
6,
13,
3,
2,
3
],
"text": [
"I believe it's usually to make sure they've got every last part of their hand. Between their fingers, under their nails etc. ",
"Most people don't thoroughly wash their hands, even when using hand sanitizer. Surgeons take their time to ensure that every nook and cranny is washed. ",
"From what I understand, sanitizer kills the organisms, but those dead \"corpses\" are all still there. The body reacts the same way to a dead virus as it does to a live one. Washing probably cleans all that dead stuff off too.",
"Sanitized dirt and feces and food are still dirt and feces and food. Stick any of those into a surgical site, the body will attack it. \n\nThen:\n\nImagine taking a steak and a bucket of white paint. Red is dirty, white is sanitized. Paint the steak. No matter how well you paint, if you bend or fold that steak enough times, you’ll eventually see more red.",
"I always thought that part of the length of the wash was drilling a routine into your head so you wash every nook and cranny of the hand (between fingers and such). I imagine that if someone wanted to there could be a cleaner or some sort of santizer (either soap or machine or both)) that could do things faster but would you really want a surgeon to do something fast or do something thoroughly?",
"The 99.9% comes from \"ideal usage\", not real world usage. Ideal usage looks a lot more like what surgeons do than what you do in the lobby of the DMV.\n\n99.9% is not enough, for surgery.\n\n99.9 applies to some types of germs. Again, 'some types' is not enough for surgery.",
"Antibacterial hand soap only kills 99.9% of bacteria if you wash your hands for at least 30 seconds. Part of the issue with triclosan is that people don't wash their hands long enough, so the more resistant bacteria persist and reproduce. Also, the scrubbing is to make sure that all the oils on their hand are washed away to avoid bacteria avoiding the antibacterial agent by hiding within them.",
"There are approved surgical foams and gels that are alcohol-based which take the place of the First Scrub as an alternative to the 3-5 minute wash at the sink with medicated, antimicrobial soap. \n\nThe aim is to reduce the load of organisms on the skin and prevent regrowth during the surgical procedure. If hands are visibly soiled, of course it is recommended that the surgical team member wash the grime off first, preferably before entering the hospital.\n\nSterile gloves are not leak proof or puncture proof. They are known to fail during procedures and often leaks/punctures are undetected during cases, even with double gloving, they're not 100%. The more effective the antimicrobial activity of the pre-scrub, the better. Alcohol-based hand-rubs have many positive attributes and are readily found at the scrub sinks. \n\n[Bonus article on efficacy of both.](_URL_0_)",
"I couldn't see any comments about spores. Some nasty bugs produce spores that are immune to those antibacterial cleaners. They stay dried out like seeds until they're put somewhere they can grow, like a human body, where they'll germinate and infect.\n\nWashing your hands quite literally washes those things off.",
"At each facility I have worked, you do an initial first scrub which consists of water, nail cleaner, cleanser and scrub brush. You clean your nails, soap up your sponge and clean hands, fingers, nails and arms. I also do this coming back from lunch. Before every other surgery, we have alcohol based cleanser that we use on our hands, fingers, nails and arms. Basically there are only two times a day we use water unless we see blood or other bodily fluids on our hands/arms. Then we must wash. Any other time we use cleanser. This has changed since I became a surgical technician 26 years ago. We used to have to scrub before each case. When you are doing 30 cataracts a day it can really abuse your skin when you have to use water and soap. Thank goodness for alcohol based cleanser."
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[],
[
"https://www.ncbi.nlm.nih.gov/books/NBK144036/"
],
[],
[]
] |
||
y4ln0 | why you only get caught for illegally downloading some things, but not others? | I've downloaded some things in the past (Community, HIMYM, etc.) and I've never been tracked or anything. But a few months ago I was downloading a file that turned out to be Iron Man 2 (I really didn't know it was that). My internet provider sent me an email warning me of the download, but why did they not mention the other things? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/y4ln0/eli5_why_you_only_get_caught_for_illegally/ | {
"a_id": [
"c5sa2mo"
],
"score": [
2
],
"text": [
"Pure luck. You just happened to be downloading the file at a time when the copyright police (basically a bunch of people at the big media companies) were tracking you."
]
} | [] | [] | [
[]
] |
|
1nrq1n | what makes computer hacking difficult, and not something a computer itself does? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1nrq1n/eli5_what_makes_computer_hacking_difficult_and/ | {
"a_id": [
"ccle6wy",
"ccleesx",
"ccleqp2",
"cclfux6"
],
"score": [
6,
4,
3,
2
],
"text": [
"Well in some cases, it does. But that's another story.\n\nConsider what computers do: very simple tasks, *very* fast. They don't (usually) screw up.\n\nNow hacking consists, fundamentally, of finding cases where people told the computer to do the wrong thing. At a very basic level, this is a deviation from expected behavior, which makes it...unpredictable. Computers suck at it because it's a *difficult* problem that can't easily be broken down into simple problems. \nOr in a nutshell, it is very hard to predict the unpredictable.",
"It's difficult for a few reasons:\n\nIn the past 20 years since computing got big, an entire *career field* has been created against hacking (computer and internet security).\n\nSince computing has gotten so much more powerful, it's difficult to overload security software which causes it to crash, leaving systems vulnerable.\n\nComputer manufacturers have had a lot of time to build systems within their operating system to overcome hacking attempts, and have a lot of people on staff working to make their systems unbreakable.\n\nAny software programmer hired to write high-level software has at least a basic knowledge of security, most probably try to hack their own software.\n\nCompanies pay big money to groups/individuals who find security holes in their software and then fix it. (But not before letting the government use them for a few months, amirite?)\n\nThere's more but I want to play GTA5 now.\n",
"Computer hacking, as the word was first used, is best described as clever, unexpected use of the technology. All it requires is intelligence and creativity.\n\nComputer cracking, the bypassing of restrictions placed there by the programmers of a system, should be impossible. But errors made by programmers leave corner cases where the system does not work as it should, allowing a user do do something the programmer did not permit. This is a battle of intellect between the programmer and the cracker, where all the cards should be in the hand of the programmer. Because of this, it should be difficult!\n\n(The difference between hacking and cracking is basically whether the original programmer would have allowed it if they knew! A good hack is applauded by the program's creator (I didn't know it could do that - Neat!), whereas an instance of a crack is reported to the authorities.)",
"First lets talk about why computer systems are hackable to begin with. Computers simply execute operations on a basic arithmetic/logical level. All of the complexity of programs, operating systems, graphical user interfaces, etc. boils down to these basic operations. They're just stacked on top of each other MANY times over by programmers to perform the more complex tasks that suit their needs/goals. The flaws in any given system, therefore, are not with the basic operation of the computer but with the greater overall logic or execution of the *person* chaining together these operations at a much higher level. There's a ton of room for error when you account for the sheer number of platforms and frameworks that are employed to accomplish varying tasks.\n\nA computer doesn't possess any sort of understanding of the purpose of the operations it is given, so it can't tell a programmer when they've made an exploitable mistake and it certainly couldn't repair itself. Without that level of self-awareness there's no way it could even begin to analyze the execution of OTHER systems all on its own. However, a computer *can* be programmed to check for certain flaws in a system and potentially exploit them if it is told explicitly what to do. Automating the process doesn't make a computer intelligent, though, and it still lacks the capacity to improvise and discover new flaws in the way a clever human might.\n\nI think a lot of people give too much credit to computers. They are fantastic pieces of equipment that enable us to do many, many things but at the end of the day they're not truly smart or magical. A computer is simply a tool."
]
} | [] | [] | [
[],
[],
[],
[]
] |
||
6dsk72 | why do some gifs load fine on the reddit app but others won't? | I've noticed it when swiping through pages, gifs will load fine, then one won't, then the next few will and one won't again, so I'm pretty sure it's not my internet connection. And it doesn't matter if I click into it or refresh the page. Am I missing something? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6dsk72/eli5_why_do_some_gifs_load_fine_on_the_reddit_app/ | {
"a_id": [
"di52u7p",
"di57b31"
],
"score": [
7,
2
],
"text": [
"I don't know why either. Happens to maybe 20% of gifs. There is an easy fix though. If it doesn't load, click the word 'imgur' just above the post title. Works a treat.",
"Reddit sync is the best app i have on my phone, works so well i bought the ad free version. It is so smooth and one of the most detailed apps i ever used! Defo give it a try if your problemo persists :)"
]
} | [] | [] | [
[],
[]
] |
|
ckivjr | baby boomers are adamant that they had it far worse than proceeding generations, how is the opposite actually true? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ckivjr/eli5_baby_boomers_are_adamant_that_they_had_it/ | {
"a_id": [
"evnr7gt"
],
"score": [
4
],
"text": [
"Let's imagine this. You're a new generation of cavemen and you have the ability to use wheeled carts to carry items. The generation before you complains on how the new generation has it \"easy\" compared to them where they had to carry every item. Although yes, the technological advancements weren't there, a new set of issues arrive for the newer generation too. What if the wheels break down? Larger advancements demands larger supplements. Can you really move at the same pace in carrying items as if you had no wheels? Regardless if you're skilled at carrying items beforehand? \n\nSame happens for the new generation. Each technological advancement brings a new set of complications for that specific grouping. Just because lets say, Africa doesn't have a large amount of people using smartphones doesn't mean that we can't complain about issues in our first world state. Someone had a leak in their home and wants to fix it, but then a homeless guy comes and says that they have it far worse in that they don't have a home at all. \n\nWith these examples, it comes more easy to understand the different perspectives that take place when talking about this topic."
]
} | [] | [] | [
[]
] |
||
7gedwm | why do some things only taste good after a few tries? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7gedwm/eli5_why_do_some_things_only_taste_good_after_a/ | {
"a_id": [
"dqiez41"
],
"score": [
9
],
"text": [
"Your body automatically rejects new bitter flavors, as many poisons are bitter. But once you have tasted them several times and suffered zero ill effects, your nervous system (basically your brain) starts to adjust."
]
} | [] | [] | [
[]
] |
||
289kuv | why do people remember car accidents or anything similar in slow motion? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/289kuv/eli5_why_do_people_remember_car_accidents_or/ | {
"a_id": [
"ci8rjkh",
"ci8szsv"
],
"score": [
2,
2
],
"text": [
"The brain's perceptual ability can have a very wide or very narrow focus depending on the circumstances. Normally you are taking in sights, sounds, physical sensation, scents, etc, in a more or less balanced manner. At the first sight of danger, the brain can essentially turn off the perception of everything but the visual stimuli. \n\nWhat's happening is not really the perception of time being slowed, but an overwhelming level of visual detail being experienced all at once. Our memory perceives this as meaning the event must have lasted longer than it actually did.",
"Experts will say that people only recall time being slowed, because of the amount of visual detail recorded, but this is wrong. Events appearing slower is an actual experience.\n\nI was once in a stressful situation, but not life-threatening. There was nothing going on to distract me, and not a lot of detail to be recorded. Suddenly everything slowed down. I was aware it was happening at the time, and was trying to figure it out. I began walking, and was moving in slow motion. Others around me were walking in slow motion. After about four steps everything shifted back to normal. It shook me up, and I have never tried to replicate the event.\n\nWhenever I see a TV program showing a lion chasing a gazelle, and the tape has been put in slow motion, I wonder if that is what the gazelle is actually experiencing. There is probably a survival strategy that kicks in in certain stressful situations, such as a lion chasing you. It gives you \"more time\" to think of a way out"
]
} | [] | [] | [
[],
[]
] |
||
131vgn | where republicans have gotten the idea that
obama is a "socialist", and why socialism is seen as
such a threat to republicans. | Edit: Is this *really* such a partisan question? Can we not objectively look at the definition of Socialism-An economy run by the government, to put it simply- and objectively look at the things Obama has done and make comparisons? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/131vgn/eli5_where_republicans_have_gotten_the_idea_that/ | {
"a_id": [
"c70477d",
"c705ll8",
"c706562"
],
"score": [
7,
7,
2
],
"text": [
"The whole basis of the republican party is smaller government, socialism is more government, thus seen as a \"threat\" to republican ideals at the very core.",
"This is one of those questions that's hard to explain simply. There are a few different things affecting the answer.\n\nTo begin with, there are decades of negative propaganda in the US around the word \"socialism\". So, a lot of the people calling others socialists aren't actually referring to specific policies. They're just saying, \"He's a bad guy doing bad things!\" This is why you see things that don't make any sense like, \"Obama's a socialist fascist!\"\n\nOn top of that, there are very few (if any) countries in the world that are run purely according to the principles of a single political ideology. Everybody runs with a little bit of capitalism, a little bit of socialism, a little bit of democracy, a little bit of autocracy, et cetera. So, when someone says, \"That's socialism!\", , they probably actually mean, \"That would result in more government oversight than we have now.\" This is why they call Obamacare, or even clean water regulations socialist. \n\nThe strange part about this is that socialism does NOT necessarily mean \"an economy run by the government\". In fact, if you look at what Marx had to say about avoiding \"[alienating work](_URL_0_)\", it sounds almost anarchist. Many of the older socialist government-run economies liked to claim that they were just assisting the transition from capitalism to socialism, with it being understood that when the transition is complete, government could be radically scaled back. There was an assumption that focusing on profit above things like the good of mankind was a result of brainwashing, and once we overcame our brainwashing and saw how selfish we were being, we would all be smart enough to realize how foolish that was in the long term. \n\nIt turns out, however, that the desire to improve one's lot in life, even at your neighbor's expense, is a much more deep-seated desire than the original socialists expected. Capitalism said, \"Well, duh! Let's run with it. Every man for himself!\" Socialism said, \"If people aren't going to figure this out on their own, we need to put some smart people in charge to keep people's greed and selfishness in check.\" From that ideological difference, we come to the shorthand of \"Capitalists want less government and socialists want more.\"\n",
"Yes, it is a partisan question. Just look at the wording of it. If you were to leave out the whole \"Where Republicans have gotten the idea\" and \"such a threat\" parts, then you might have a question more people would be willing to look into answering. As it is, I'm not even going to bother talking to you about it."
]
} | [] | [] | [
[],
[
"https://en.wikipedia.org/wiki/Marx%27s_theory_of_alienation"
],
[]
] |
|
3bctaz | why emergency vehicle (police/fire/ambulance) sirens sometimes sound like the driver is repeatedly pushing the siren button causing the pattern to constantly restart, rather than just keeping the siren on? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3bctaz/eli5_why_emergency_vehicle_policefireambulance/ | {
"a_id": [
"cskzcgy",
"csl361j"
],
"score": [
9,
3
],
"text": [
"Modern emergency vehicle sirens, typically made by federal or Whelen \n\nThe standard modes are usually \"wail\" and \"yelp\" which are the two typical police sirens. Then there is usually a button for an airhorn and a manual burst siren. \n\nThe manual burst siren is what they use to alert you to a traffic stop if you don't notice the flashing lights behind you. And airhorn is what they use to clear an intersection. \n\nThis is a good demo of the typical buttons in an emergency vehicle. _URL_0_\n\n\nFire trucks and old 50s era police cars often also have a secondary rotary siren, usually made by Whelen that sounds like this _URL_1_\n\nRotary sirens were also used in air-raid sirens. They have a motor that spins the a fan every few seconds, so the siren pulsates. \n\nSo I'm not sure which you're referring to. My gut tells me you're thinking of air-horns, or a cop who just likes playing with the buttons as they clear the intersection.",
"The changes in pattern and siren type are to keep those around the emergency vehicle alert. The human brain likes things in patterns so that you can concentrate on it less, and sirens, even when loud, will start to get faded out by your brain after a while. Think of it like music at a club, if it's the same repetitions over and over you start to notice it less and less. \n\nSo what they do is have the pitch and pattern change constantly to keep nearby drivers alert to the presence of the vehicle and ensure they will be ready to move out of the way if needed. Similar to how highways are always curved as to ensure drivers won't get drowsy or lose attention on a super straight road."
]
} | [] | [] | [
[
"https://www.youtube.com/watch?v=UYqgBITv_DA",
"https://www.youtube.com/watch?v=uSVDiCkXmPk"
],
[]
] |
||
3aotsd | why crt tv's have that line going through them when recorded by a camera | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3aotsd/eli5_why_crt_tvs_have_that_line_going_through/ | {
"a_id": [
"csela92",
"cseldrk"
],
"score": [
2,
5
],
"text": [
"Someone may want to confirm this, because it's just an educated guess, but I think the frame rate of the camera is such that it picks up the crt scanning lines in the way we see it..... similar to how a helicopter rotor may appear to spin slowly backwards.",
"CRTS work by an electron beam scanning down the screen line by line hitting phosphoros dots and lighting them up. It does this 50 times a second.\n\nAt the same time a camera is effectively doing the reverse, it is sampling it's light sensor line by line, 50 times a second. The problem is that the scan rates are rarely in sync, so the camera ends up catching the CRT halfway through it's scan.\n\nThere are special devices that are used by the television industry called genlocks which allow a camera and CRT tv to be synced so that the line does not appear"
]
} | [] | [] | [
[],
[]
] |
||
3p4133 | why can some animals go weeks without eating, but humans need food on a daily basis? | For instance snakes or big cats can eat an animal one day and not half to eat for the rest of the month | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3p4133/eli5_why_can_some_animals_go_weeks_without_eating/ | {
"a_id": [
"cw2x0uw",
"cw2xxsd",
"cw2z719",
"cw30n0a",
"cw32t7b",
"cw39y7c",
"cw3hw2n",
"cw3iitq"
],
"score": [
14,
87,
65,
24,
2,
3,
3,
4
],
"text": [
"Its just a habit. You as a human can probably go up to a month without eating, just burning your fat reserves. \n\nEdit: There are several reported cases of humans (pretty obese) to live from their fat alone for up to a year. ",
"Animals that don't eat as often tend to eat much more at each meal. For example, wolves eat only a couple of times a week, if that, but during each meal session they eat somewhere around 15% of their body weight in food. If humans ate like that, they would eat ~20-30 pounds of meat in a single meal.",
"Humans are perfectly capable to surviving while eating like predators (2-3 days worth of calories on some days, nothing on other days). It's just not comfortable and not ideal for long-term health. The idea that you'll get sick or go into \"starvation mode\" from not eating for a day is bullshit perpetrated by people who've never missed a meal in their life.\n\nSnakes are cold-blooded and therefore need very few calories to maintain their basic metabolic functions, as well as being ambush predators that use very little energy hunting.\n\nSome small invertebrates, like scorpions, have such efficient metabolisms and are so inactive that they can survive on one meal per month or less, because their body only uses the minimum required to keep their immune system and other vital functions going any time they're not actively hunting.",
"Humans do not need food on a daily basis, this eating daily thing is pretty new to our species. For the most part humans ate every other day. We are able to run for about 5 days straight only stopping to drink water while chasing our prey. Humans have the best endurance of any mammal. ",
"Humans don't actually need to eat all that often. One meal a day in terms of standard American size is enough for you to live. You might not like it since you haven't eaten that way before, but your body can. Multiple people have lived months before dying of starvation.\n\nAlso to clear up a misunderstanding you might have, other animals don't like to go weeks without eating. Most animals (humans too!) prefer to eat at least once a day. ",
"First of all your initial premise is wrong. Humans can go without food for a long time as well, but we cant go without water for long. ",
"We don't need food on a daily basis, it's simply what we prefer. If you have ever gone hungry you probably noticed that your hunger abated after a day or two. Human beings can go weeks without food provided you have the body fat for it but switching over from aerobic and carbohydrate based metabolism, to a more anaerobic and keytone based metabolism takes a few days. When you stop eating food your stomach and intestines have residual food left. This lasts a few hours. Then your liver has built up reserves of energy and this takes a day or two to become exhausted, at that point your body starts burning fat reserves but it's slow to switch to this. Your body breaks the fat and some muscle and organ protein down into ketone bodies which your body can use for energy. This is a slower process than the energy your liver can provide so you tend to be more lethargic and you don't get a burst of energy like you do after a trail mix bar but the energy that is there can last a long time as you burn fat. \n\nIf this goes on for a few weeks your body will start to cannibalize it's own organs and muscles in addition to the fat, if it goes on a very long time, several weeks for instance, this can weaken your heart and organs which will make you very weak and eventually lead to your death. \n\nYou can go weeks without food, it's not good for you but it wont' kill you. You can't go more than a few days without water before you start dying by comparison. \n\nCompared to animals there are a few big differences in our digestion and energy making organs. We have pretty tiny stomachs and ridiculously short digestive tracts compared to other animals. This comes from eating frequently, cooking our food which makes it easier to digest, and it's a good fit for our way of living. \n\nTake an animal like a lion for instance which can eat a much higher percentage of it's body weight in food compared to a human and it has a longer digestive tract to get every last bit of nutrients out of it that it can. Animal livers can also be much larger than human livers for body weight which allows them to store quick energy for longer periods without food. Our liver is very specialized though and it can do things that animal livers can't. For instance we can eat lots of caffeine and chocolate, which are poisonous to many animals and insects but our livers are able to break down and metabolise them quickly enough that it doesn't hurt us and we may even find them delicious. This is why dogs can't eat chocolate for instance, the something something thylobromide can't be metabolised fast enough and it can reach toxic levels where as our liver breaks it down very quickly. \n\nOn the other hand a dog liver can hold a lot of energy. So animals can eat more at once and go longer between meals. This is a good thing because when you hunt, you put yourself at risk of becoming hurt or killed, especially when hunting things that are bigger than you. The less often you need to do it, the less risk you take. Better to take down 1 bison a week and eat it all at once, than to kill one every day and just eat a little. \n\nThen you have cold blooded animals like reptiles which don't need to waste energy heating their bodies up so they can go very long periods of time without eating and without storing fat because their metabolic needs are far less than warm bodied animals. \n\nThen you have birds, which ironically are descended from reptiles yet their metabolism is a polar opposite, they must eat constantly because their bodies need large amounts of energy. Humming birds are at the extreme end and they burn so much energy flying they can't go very long at all without eating. I once saved a hummingbird that knocked itself out on my window. It was VERY weak when it regained consciousness, I could hold it in my hand and it just sat there staring at me and being very lethargic. Over a few hours I fed it soda pop by holding my finger over a straw and putting the end over it's beak and letting it get the HFCS energy. It became more active after doing this and I was able to release it and it flew away. ",
"What makes you think humans need food daily? "
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[],
[]
] |
|
3masti | how is it that vets can treat multiple types of animals with similar training as doctors who only have humans to deal with? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3masti/eli5how_is_it_that_vets_can_treat_multiple_types/ | {
"a_id": [
"cvdhi8l",
"cvdi5oz"
],
"score": [
6,
2
],
"text": [
"There are some veterinarians who do specialize. They specialize both when it comes to what sort of animals they treat and what sort of problems they treat. There are horse-doctors and Animal dentists for example.\n\nMost of them however are more general practitioners.\n\nThis is possible because the difference between a cat and a dog is not really all that big for example and a lot of general medical knowledge can easily be applied to lots of different animals. Being able to care for two different species does not take twice the general medical knowledge as being able to care for a single one.\n\nThe other factor is that we allow for a much greater room for error when it comes to animal care. If a pet could not be saved because a veterinarian did not know about some extremely obscure bit of knowledge about some rare animal malady that is considered slightly more acceptable than when it would happen to a human patient.",
"It may be due to the amount of ailments and issues that cats/dogs come up with comparatively to humans. As /u/Loki-L said, there is greater room for error when it comes to animals. Doctors for ailments regarding humans must know a wide range of maladies that affect us from the flu, to infections and wounds. For the most part, animals only have to deal with a smaller number of things before it becomes more specialized."
]
} | [] | [] | [
[],
[]
] |
||
2kdebe | if bathroom hygiene is so important why don't we get sick after performing oral sex? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2kdebe/eli5_if_bathroom_hygiene_is_so_important_why_dont/ | {
"a_id": [
"clk79y9",
"clk7c0q",
"clk7d6l",
"clk8948",
"clk8r6s",
"clk8ugd",
"clk9dyt"
],
"score": [
24,
14,
3,
2,
2,
9,
7
],
"text": [
"It's more a matter of frequency. If you consider all the times in a day you touch a person (shake hands, etc.) or touch something they touch (doorknobs, etc.), it ads up to a lot of exposure. \n\nIf you sucked that many dicks, every day, from that many random people, you would probably get sick a lot.",
"I don't know about you, but me and my ex made a habit of you know.. refreshing our selves before we did anything. Not because we were gross individuals but because it just made sense to us.",
"I've never died in a plane crash. That doesn't mean planes don't crash or that people don't die as a result of plane crashes. STD's can and are sometimes transmitted via oral sex. For some types of STD's, the likelihood is somewhat diminished in proportion to becoming infected by way of vaginal and/or anal sex but the possibility does exist and people do \"get sick\" because of unprotected oral sex.",
"What do you mean by \"get sick\"?...a cold? Flu? If that's what you mean then the answer is: because you catch a cold or flu virus from hand contact or from someone coughing/sneezing on you. Now, if you're the one giving oral and the receiver has a cold, they could cough on you or cough in their hand then touch your face and you'd get sick. But you won't catch the cold from their genitals. (Sorry for my tame choice of words. I'm a nurse...trying to keep it professional;)\n",
"I don't think it's the weiners that are the major culprits... it's the hundreds/thousands of instances of hand-to-object-to-hand contact in a place like a bathroom that are.\n\nJust wash your hands often. And shower once a day. You'll be fine.",
"Hygiene is a habit. Oral sex only happens 3 times a day.",
"I know plenty of men that wash their hands before heading to the urinals with the mentality of \"my penis is the cleanest part of me (not in contact with the outside world after showers etc.) but my hands are disgusting because they've been everywhere.\" So it's really a hygiene factor if we're talking about basic viral/bacterial infections. \n\nNot a medical professional. "
]
} | [] | [] | [
[],
[],
[],
[],
[],
[],
[]
] |
||
8t6r2y | how did people get enough heat to smelt metals before the industrial age? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8t6r2y/eli5_how_did_people_get_enough_heat_to_smelt/ | {
"a_id": [
"e156p62",
"e156rsf"
],
"score": [
2,
2
],
"text": [
"Coal fire forges are able to reach temperatures of about 1900 degrees C which is more than enough to melt most ‘primitive’ metals such as iron, bronze, copper and steel. ",
"They melt at much lower temperatures than you might think.\n\nYou can take raw iron ore and pack it into a \"bloomery\" which is basically a mud-and-brick covered pile of ore and coal/charcoal. Light it on fire and the outer materials insulate the inner layers, and the heat eventually gets to the point where the iron melts out of the ore and pools in the bottom.\n\n[Blast furnaces](_URL_0_) have also existed for about 2000 years."
]
} | [] | [] | [
[],
[
"https://en.wikipedia.org/wiki/Blast_furnace"
]
] |
|
cqfp3k | why does english pop up everywhere? like in anime, and foreign music they just say a line in english and then just back to their respective languages. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cqfp3k/eli5_why_does_english_pop_up_everywhere_like_in/ | {
"a_id": [
"ewvxcwb",
"ewvxhkw",
"ewvxi6z",
"ewvxqdx",
"ewxbbc9"
],
"score": [
12,
9,
2,
11,
3
],
"text": [
"Because it's currently seen as the lingua franca of the western world I'd reckon",
"English is the world's most popular second language. Hundreds of millions of people know a little English, enough to understand a word or two thrown into a song for fun.",
"I think it has to do with a couple of things. If it's an English company name, like Apple, they would say the name of the company since it's a Pronoun. Just like we would say Toshiba, for example. The other could be common phrases, like OK or GOODBYE. Just like how we might say Adios or other common phrases in other languages. Sometimes it's just fun!",
"Mostly because there is no word in that particular language for whatever it is they are referring to.\n\nSo for eg, very few languages have a word for rocketship or blackhole. They could use the litteral words to replace them, but that combination probably already exists and means something else.\n\nIf you want to say rap battle in urdu then you're gonna have a hard time. So you would just say rap battle.\n\nLanguage is at the end of the day a tool to express. If your expression is understood, then you won.",
"At different times, different languages are dominate across borders, which shapes other languages. It becomes trendy or profitable to know the dominate language and eventually, it gets ingrained in the other language. Right now, that language is English, but that is relatively recent and in the past English has absorbed other languages in the same way. \n\nWhen you broil beef to serve to the sergeant in the army, you are using a lot of words that came from french - Broil, beef, sergeant, and army all originate from French, which was the \"lingua franca\" of the world for a long time. \n\nWhen someone's husband looks through a window at a cake, you are using a lot of Scandinavian words that came in when the Vikings were trading/raiding England (husband, window, cake). \n\nEven today, we have major loanwords from all over - tsunami, blitzkrieg, kindergarten, schlep, schmuck, fika, hygge, croissant, ninja, baguette, smorgasbord, karate, piste, lego, kaputt, bikini, karaoke, teriyaki, etc. We insert these because we like them and they fit a particular use. Other languages do the same thing, but with English terms. \n\nAnother factor that significantly caused English to be a dominate language was the spread of the English Empire, which at it's height covered a huge amount of the world. More recently, the success after WWII of the US reinforced English as a world language - The occupation of Japan and subsequent preferred trading status to boost their economy caused English to become a major language there and the success of US and British companies in being major players in the oil industry in the middle east was influential in making English (and the dollar) relevant there. \n\nOutside of that, knowing English is profitable in many places and is essential for programming, business, and more. It's a social status indicator in many places and in other places, English is a second language. For example, in the nordic countries, just about every last person is fluent in English today - in 1915, most people spoke German, not English, which represented who they predominately traded with. \n\nSo, basically, it's a prestige language in many places, seen as \"cool\", and English has become the main international language (for the time being)."
]
} | [] | [] | [
[],
[],
[],
[],
[]
] |
||
53e6b3 | - why do people want ivory so bad and why is it illegal? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/53e6b3/eli5_why_do_people_want_ivory_so_bad_and_why_is/ | {
"a_id": [
"d7sa2ig"
],
"score": [
3
],
"text": [
"Before the advent of plastics, ivory was a very durable alternative to wood. It was considered a luxury good because of its relative scarcity. Most countries have made ivory trade illegal because harvesting it requires killing of endangered elephants."
]
} | [] | [] | [
[]
] |
|
3m94kc | what is the difference between a credit card reader and a chip-and-pin machine? | Somebody told me that credit card readers are really only used in the US and the rest of the world uses something called a chip-and-pin machine. What exactly is the difference? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3m94kc/eli5_what_is_the_difference_between_a_credit_card/ | {
"a_id": [
"cvd2dx2",
"cvdc68r"
],
"score": [
4,
2
],
"text": [
"Chip and pin cards look [like this](_URL_0_), where you insert the chip into [the reader](_URL_1_), and are prompted to enter a PIN number (like an ATM) before you can make a purchase.\n\nTraditional credit card readers just [swipe the magnetic strip](_URL_2_), and you sign the receipt.\n\n**Edit**: Added images.",
"Magnetic stripe card readers use the same technology that older computers used to store data on magnetic tape, The magnetic stripe on the credit card just stores the same information as is written on the card but in a format that the computer can read easily. \n\nThe chip on a chip and pin card is a small computer with one job, it stores the same information as the magnetic stripe but it also has a complex encoding system on it, when you put the card into a chip and pin reader it contacts the bank and sends them the id details from the card (basically the long number). The bank knows that the credit card for that account has a certain chip on it, with a secret code and your pin number, the bank then chooses a long random number and does some maths with all the bits it knows and comes up with a final number, the bank then sends the same random number to the chip in your card (via the chip and pin reader) and asks it to do the same maths. If your pin is correct, the chip is the right one, and the secret information on the card is correct, the chip will come up with the same final number as the bank did proving that you have the right card and pin.\n\nNow if someone reads the magnetic stripe on a credit or debit card they can send that information to the bank over and over until you report the card stolen and the bank eventually blocks it. But if someone reads the number sent from the chip and pin reader back to the bank, they only know how to answer for that specific random number sent by the bank. And as the bank will not send that number again they cannot pretend they still have the card."
]
} | [] | [] | [
[
"https://paymentdepot.com/wp-content/uploads/2015/08/chip-n-pin.jpg",
"http://moneris.com/help/iwl255_webhelp/images/iwl255_insert_chip.jpg",
"http://cdn.barcodesinc.com/images/models/lg/MagTek/sureswipe.jpg"
],
[]
] |
|
1vw3dn | why is it that the majority of the police officers/military in corrupt states defend the corrupted governments? | I read a comment earlier that hit me pretty hard. It said something along the lines of:
"...as soon as these policemen get off their shift, they are just as oppressed as the rest of the citizens in that state."
So why do they stand for it, then? Why do they defend the corruptness and try to silence the victims of the fallen government?
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vw3dn/eli5_why_is_it_that_the_majority_of_the_police/ | {
"a_id": [
"cewc42p"
],
"score": [
2
],
"text": [
"Cops aren't as oppressed as those they help oppressed. Cops break the law a lot more than your average citizen and their position lets them get away with it. As long as they keep those in power they get to keep their jobs and the perks that come along with it."
]
} | [] | [] | [
[]
] |
|
3t5p53 | why do some people who's parents are immigrants have an accent while others don't ? | I have some friends who's both parents are from other countries but not all of them have their parents native land's accent can you explain it ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3t5p53/eli5_why_do_some_people_whos_parents_are/ | {
"a_id": [
"cx39nxv"
],
"score": [
3
],
"text": [
"Accents tend to come more from peers than parents. So someone who grew up in an area where all the friends and neighbors share the same accent, or perhaps went to a private or parochial school where that was the case, will more likely have a similar accent. But when children go to assimilated schools, especially at the younger ages, they're more likely to get that accent than their parents'. "
]
} | [] | [] | [
[]
] |
|
3d2vj0 | why do we use olive oil instead of frying oil when stirfrying vegetables? | Title. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3d2vj0/eli5_why_do_we_use_olive_oil_instead_of_frying/ | {
"a_id": [
"ct1dh5k"
],
"score": [
5
],
"text": [
"Properly stir-frying anything requires using really high temperatures.\n\nMost olive oil has a relatively low smoke point (the temperature at which it starts to break down & smoke). Stir-fry oils are generally things that handle temperatures better like corn, peanut, canola & soy.\n\nThere's also the bit that olives are not native to Asia, where stirfry recipes are from so the flavor profile of olive oil (which is relatively pronounced compared to many other cooking oils) is a poor match for the types of dishes you'd normally be stir frying."
]
} | [] | [] | [
[]
] |
|
3mxjni | why european civilizations were so much more advanced in terms of everything compared to african and native american civilizations. and so when white ppl came to america they basically just took over with guns. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3mxjni/eli5_why_european_civilizations_were_so_much_more/ | {
"a_id": [
"cvj0df1"
],
"score": [
3
],
"text": [
"_URL_1_\n\n_URL_0_\n\n_URL_5_\n\n_URL_2_\n\n_URL_3_\n\n_URL_4_"
]
} | [] | [] | [
[
"https://www.reddit.com/r/explainlikeimfive/comments/1o2t90/eli5_considering_that_humanity_and_civilization/",
"https://www.reddit.com/r/explainlikeimfive/comments/115q2q/eli5_why_africa_is_so_underdeveloped/",
"https://www.reddit.com/r/explainlikeimfive/comments/3523y5/eli5_why_did_anglosaxon_white_european_societies/",
"https://www.reddit.com/r/explainlikeimfive/comments/1rdiem/why_is_africa_so_far_behind_in_technology/",
"https://www.reddit.com/r/explainlikeimfive/comments/1pa50z/eli5_why_is_there_such_a_stark_contrast_in/",
"https://www.reddit.com/r/explainlikeimfive/comments/2l9p56/eli5_why_tribal_populations_in_north_and_south/"
]
] |
||
arrggi | the united states is over $22 trillion in debt. what does that mean? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/arrggi/eli5_the_united_states_is_over_22_trillion_in/ | {
"a_id": [
"egp768t",
"egp7zce",
"egp92gm"
],
"score": [
5,
2,
2
],
"text": [
"Not a whole lot, actually. Somewhere between 70-80% of that debt is held by American citizens in the form of bonds, including savings bonds. Bonds are heavily used as a stable investment to protect your money from inflation (the rates on the bonds basically keep up with the rate of inflation). And none of the debt is callable, which means that the individuals holding the debt cannot just order to be paid everything due in advance of the payment schedule. \n\nIn effect, as long as the GDP grows at about the rate of inflation, the amount of debt that the US has is stable. If inflation shoots up, or if GDP falls heavily, it can get a little bit tricky. But that's why we've got the Federal Reserve to look out for those things well in advance and take action to mitigate it before it becomes a problem. ",
"The US government is heavily funded by financial instruments such as bonds. In exchange for cash now, the US treasury will give you more cash later. That debt is about $22 trillion.",
"Imagine you have a bunch of credit cards and you owe 22 trillion. This is the United States if it was a person. The only difference is the United States can choose what interest rate it charges itself. Now you might say to yourself, I’ll charge myself 0%, well yes and no. In order to get people to buy your debt (bonds) you need to pay them some interest. Bonds are seen as secure investment by every government in the world because we are seen as a stable economy. Most US citizens by bonds for the same reason, we will get our money back. Now the deficit is meaningless in terms of how much we produce (GDP) but you don’t want it to continually grow long term. "
]
} | [] | [] | [
[],
[],
[]
] |
||
1sl6ow | what is the bubonic plague, and would it be as fatal today as it was in the middle ages? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1sl6ow/eli5what_is_the_bubonic_plague_and_would_it_be_as/ | {
"a_id": [
"cdyonux",
"cdypof9",
"cdyqtxs",
"cdyxrqs"
],
"score": [
34,
3,
3,
2
],
"text": [
"Bubonic plague is a specific kind of disease caused by the bacteria Yersinia pestis. (Pneumonic and septicemic plague are the other kinds, less famous because they didn't destroy Europe.) Yersinia lives in fleas, which live on rodents. As a result, plague was able to spread very quickly in a time when sailors could bring rats across the Mediterranean, and when huge numbers of people lived in crowded, filthy cities where parasites were a normal part of life.\n\nIs it as deadly now? No. Antibiotics have made plague dramatically more survivable, while hygiene in the developed world means you're highly unlikely to get fleas. In fact, when plague was found in squirrels near Los Angeles, the only response was to close a few campgrounds. There are many fine things to worry about, but the Black Death isn't one of them.",
"This is from today\n_URL_0_",
"Bubonic plague actually still exists, and an outbreak in Madagascar was announced just today. It's certainly survivable these days because we understand more about it and have developed effective treatments against it.",
"Survival rates for the bubonic plague with modern antibacterial treatment are 85%-99%. Survival rates without treatment is more like 40%, which is what happened in the middle ages, combined with poor hygiene and wound treatment that made nonfatal side effects significantly more dangerous. I actually knew a guy in boy scouts when I was a kid who apparently contracted it from infected rodents living under his family's cabin or some such. He was treated and suffered no long term ill effects, though I think catching it early is pretty important, as untreated it kills the infected in less than a week, so there's not a lot of time to wait and see."
]
} | [] | [] | [
[],
[
"http://www.reddit.com/r/worldnews/comments/1skdzu/confirmed_outbreak_of_bubonic_plague_in/"
],
[],
[]
] |
||
301iom | how do cough suppressants, decongestants and expectorants work together to help with a cold? | Most cold medicines have a combo of the 3, and to me it seems counterintuitive to take more than one at a time. For example, why take an expectorant if I'm taking a cough suppressant? Don't i need to cough to get that stuff out? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/301iom/eli5_how_do_cough_suppressants_decongestants_and/ | {
"a_id": [
"cpoa9wg"
],
"score": [
2
],
"text": [
"None of the above help colds. They help the symptoms of a cold. Decongestants, fine. Cough suppressants and expectorants seem illogical if mixed but separately they might help the symptoms. \n\nMany of this type of symptomatic \"cure\" has ingredients that defy strict logic. Despite this, people buy them."
]
} | [] | [] | [
[]
] |
|
1jc7wr | why are vishnu and his avatars blue? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1jc7wr/eli5_why_are_vishnu_and_his_avatars_blue/ | {
"a_id": [
"cbd7xt2"
],
"score": [
2
],
"text": [
"Blue is considered a divine/pure colour. \nI.e. connected to the sky / the sea"
]
} | [] | [] | [
[]
] |
||
b9wwcw | why did ants ( and other insects maybe idk) get an exoskeleton rather than a normal skeleton? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b9wwcw/eli5_why_did_ants_and_other_insects_maybe_idk_get/ | {
"a_id": [
"ek7hjqf",
"ek7ldsl"
],
"score": [
6,
3
],
"text": [
"Because a hard outer shell doubles as protection from predators, as well as anchor points for muscles.\n\nEndoskeletons evolved to provide otherwise soft-bodied animals leverage to generate more power in their appendages without sacrificing as much flexibility as an exoskeleton.",
"Insects are part of a larger group of animals called Ecdysozoa, all of which have the ability to shed the outer layer of their skin, or cuticle. Though some members of the Ecdysozoa are still somewhat soft-bodied, like [roundworms](_URL_3_), one group developed a much harder and more inflexible outer cuticle with segments and jointed limbs to allow some movement. This group, the Arthropoda, contains most animals we think of as having exoskeletons, including the extinct [trilobites](_URL_0_), as well as the still living [chelicerates](_URL_4_) (most of which are arachnids), [myriapods](_URL_8_) (centipedes and millipedes), and pancrustacea (which consists of crustaceans as well as insects, which are [nested inside crustaceans](_URL_6_)).\n\nPresumably, the exoskeleton in arthropods developed as a form of protection against predators, but it's hard to be completely sure, since it first appeared in the ancestors of this group which lived over 500 million years ago. The benefits of this kind of protection are obvious, and importantly, the preexisting ability to shed their skins allowed them to continue to grow larger over their lives, and even regrow lost body parts. Having a tough outer covering also helped arthropods like [*Pneumodesmus*](_URL_5_) to become the first animals to colonize land, tens of millions of years before vertebrates would ([source](_URL_7_)). Interestingly, though earlier arthropods probably shed their skins regularly throughout their lives (as many still do today), the majority of insect species no longer do this, and instead have a finite number of moults they go through as they grow before reaching a final and permanent adult stage.\n\nAs opposed to arthropods and other ecdysozoans, the ancestors of vertebrates (the earliest of which lived around the same time as the first arthropods \\~500 million years ago, like [*Haikouichthys*](_URL_2_)) were relatively soft and did not shed their skins. However, they did have rigid internal structures like notochords made of cartilage-like materials, which allowed them to swim effectively using full body [movements from side to side](_URL_1_). Eventually, bones developed from cartilage in vertebrates, leading to the internal skeletons we have now."
]
} | [] | [] | [
[],
[
"https://static01.nyt.com/images/2014/03/04/science/trilobites-1393889944421/trilobites-1393889944421-videoLarge.jpg",
"https://images.slideplayer.com/14/4427902/slides/slide_11.jpg",
"https://i.pinimg.com/originals/02/19/83/021983b5aef75ae3287aa4384a9d1f1d.jpg",
"https://ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html",
"https://www.researchgate.net/profile/Prashant_Sharma18/publication/326569287/figure/fig1/AS:652419352498176@1532560303089/Examples-of-chelicerate-diversity-Left-column-top-Isometrus-sp-Scorpiones-Left.png",
"https://i.dailymail.co.uk/i/pix/2017/07/05/23/421115C200000578-4669222-image-a-72_1499294547822.jpg",
"https://whyevolutionistrue.wordpress.com/2010/03/04/insects-are-crustaceans-2/",
"https://www.academia.edu/891357/Early_terrestrial_animals_evolution_and_uncertainty",
"https://upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Myriapod_collage.png/1200px-Myriapod_collage.png"
]
] |
||
2ye88c | do people who talk languages other than english think in those languages? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ye88c/eli5_do_people_who_talk_languages_other_than/ | {
"a_id": [
"cp8otxn"
],
"score": [
2
],
"text": [
"Do you think in English?\n\nSeriously, when you think of a dog running across a field, do you imagine those words \"a dog running across a field\"? Or do you imagine an actual dog running across an actual field?\n\nThe only times that we actually think in words, is when we are thinking of a language. I could think \"My name is Thomas\" in those words, I could also think \"Je m'appelle Thomas\", or I could think in the abstract sense that Thomas and myself are one in the same.\n\nIt's similar to \"how do deaf people think?\""
]
} | [] | [] | [
[]
] |
||
80u2q7 | what happens to the food company when someone who is allergic to a secret ingredient consumes their food? will it be revealed? why has it not ever happened? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/80u2q7/eli5_what_happens_to_the_food_company_when/ | {
"a_id": [
"duy7oxk",
"duy9xlo"
],
"score": [
5,
2
],
"text": [
"I think due to FDA regulations all ingredients must be listed, so the secrets are usually formulas and combinations. But the individual ingredients that people may be allergic to are listed. ",
"there's a list of specific allergens that must be listed if it's in the food or if the food could come in contact with that. other than that, everything's fair game. only prepacked products are subject to fda labeling requirements. other than that, it's up to the eater to due their diligence. "
]
} | [] | [] | [
[],
[]
] |
||
3j0cns | if it is illegal to melt down pennies, how is it legal to press them? | I started looking at my small collection of squashed coins, and it made me think. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3j0cns/eli5_if_it_is_illegal_to_melt_down_pennies_how_is/ | {
"a_id": [
"cul7o2w"
],
"score": [
9
],
"text": [
"Are you talking about how it's legal for the US Mint to press them? Because they're authorized by law to do so.\n\nIf you're asking about those novelty machines that strech out a penny, it's because defacing the currency for non-fraudulent purposes isn't illegal."
]
} | [] | [] | [
[]
] |
|
3k85qd | why the american corn taste different from middle eastern corn or asian one? | When i came to usa i tried to taste the american corn from mijier, ( i never tried anything from supermarket so i wouldnt know) and it taste sweet and different. I didnt like it. To me it is not delicious. Ahs ever been like this forever? Or something changed in the middle? Or is it that i am just baised and used to my country food? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3k85qd/eli5_why_the_american_corn_taste_different_from/ | {
"a_id": [
"cuvgswj",
"cuviep9",
"cuvkdqp"
],
"score": [
9,
7,
2
],
"text": [
"They differ in species, soil composition, environment, exposure to the sun. These all could effect the taste.",
"There are many different variations of corn. In Korea (s), supermarkets usually have 2 or 3 different corns in the vegetable section (starchy, sweet). In the US, it's usually the same sweet corn, unless you have a large farmers' market.",
"the corn can only build itself from whatever nutrients it can obtain.\n\nif you plant something in another soil that has different properties these properties will change the plant.\n\nafter a few generations of this your plant will evolve to better cope with the changed soil conditions (with assistance of the farmer who seeks to maximize his yield), resulting in \"different\" corn."
]
} | [] | [] | [
[],
[],
[]
] |
|
7aguu2 | what's the difference between tense, mood, and case? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7aguu2/eli5_whats_the_difference_between_tense_mood_and/ | {
"a_id": [
"dp9vd8w"
],
"score": [
3
],
"text": [
"Tense is the time of the action, past, future, happening right now. The tenses give a sense of when an action was completed, or if we expect the action to continue into the foreseeable future. It puts the verbs into a context of when. \n\nMood adds or removes a certain certainty or uncertainty or more commonly, obligation. We use modal verbs to add a stronger sense of obligation (must, have to) or soften a statement to suggestion (should). We don't really moods in English because we use these modal verbs, if you study Italian then you'll see mood a lot use with different verbs - \"essere\", to be, changes to \"sia\", for example, the actual verb \"to be\" changes the mood of the sentence, in English we add \"should\" and leave the next verb alone \"he should leave\". \n\nCases you'll see a lot in German, which is when the pronoun changes depending on who is doing what to whom. We have them in English too, but not to a greater degree as in German. For example, you don't say \"I'll give the bucket to he\", you say \"I'll give the bucket to him\". The possessive is \"his bucket\" - the cases that we have in English mean that you must change \"he\" to \"him\" and \"he\" to \"his\" depending on who is doing what to what/with what object. He is 'owning' his bucket\". \n\nThis is my understanding of it, at least, having taught English for 10 years and studied Italian, German and French. "
]
} | [] | [] | [
[]
] |
||
b15c9b | if peanuts aren't actually nuts why do people with a nut allergy die from them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b15c9b/eli5_if_peanuts_arent_actually_nuts_why_do_people/ | {
"a_id": [
"eije5ir"
],
"score": [
7
],
"text": [
"Because peanut allergies are different from nut allergies. I'm allergic to peanuts but not nuts. "
]
} | [] | [] | [
[]
] |
||
55hnmh | why does my cat retain the ability to bound at 30 mph and jump vertically 5ft if he sleeps all day? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/55hnmh/eli5why_does_my_cat_retain_the_ability_to_bound/ | {
"a_id": [
"d8ao0tp",
"d8aon56",
"d8ap9mu",
"d8apquh",
"d8aq0m4"
],
"score": [
232,
55,
16,
2,
179
],
"text": [
"I assume your cat, like almost every cat, likes to jump up on things and tends to go bat-shit crazy in the middle of the night and run around like a maniac sometimes. This is its exercise. \n\nCompare that to a reasonably fit human that works out regularly - not a gym nut or anything but just a guy who works out like twice a week to stay healthy and fit. He'll probably work out for what, a couple of hours? And that won't be nonstop, it'll be in sets with frequent breaks. So in reality he spends less than 30 minutes actually exercising, and he does that twice a week. So less than an hour per week exercising and he's perfectly fine.\n\nTL:DR You only need to exercise a little to maintain your muscles.",
"Other animals don't need to \"work out\" to stay strong. Humans lose muscle because it helps us reduce calorie needs if we're not using those muscles. Hence why you can go 30 days or so without food and still survive (in decent conditions). Look at how strong gorillas are, they literally sit around all day just eating grass or whatever. They're not banging out push-ups on the side or anything. \n\nSource: some askscience thread I read a few months ago I think ",
"There is evidence to show that it might be related to purring - they purr as a form of self healing and to keep their muscles toned: _URL_0_",
"They have explosive energy stores so they don't exercise heaps.\n\nThey exercise in short bursts throughout a 24 hour period.\n\nEg cat goes crazy at night and hunts during the day for like 20% and sleep the rest.\n\nEg2 my dog sleeps all day but will run around the yard when i let him out first thing in the morning. I take him for walks but it is as much for me as him.",
"Every species maintains a certain natural muscle mass. Obviously if you go to extremes you can either lose most of it (muscle atrofy, ever had your leg/arm in a cast for a few months?) or gain a lot more (like bodybuilders). The \"natural state\" is determined by our DNA.\n\nAs an example, look at these two animals:\n\nThe [Belgian Blue cattle](_URL_2_) maintains an enormous amount of muscle mass despite leading a rather stationery life. It was selectively bred for beef. The Belgian Blue has a mutation that prevents Myostatin from inhibiting muscle growth. Because of the amount of muscle it has, it devours extreme amounts of food but that's not a problem because humans feed it.\n\nThe [Gibbon](_URL_0_) maintains a relatively low muscle mass despite leading a rather active life. It's Myostatin is working just right - preventing excessive muscle growth when it's moving a lot.\n\nThe amount of muscle mass an animal has is in it's perfect ratio - enough to move, jump and do stuff but not too much, because it would have to eat a lot more. Muscle atrophy, on the other end, only occurs when there's hardly *any* movement, not just little movement.\n\nA great example of this is bodybuilding. You can lose a lot of muscle very quickly if you stop working out but at a certain point (the natural state of human muscles) that loss will stop as long as you walk around and do stuff. Only the excess is lost quickly. That's also why you can sit at a computer for 10 hours a day without atrophy. [This graph illustrates it.](_URL_1_)\n\nHumans have evolved to use our brains more than our muscles so our natural state is just enough to walk around and run for a few hundred meters at 10 km/h. Cats still rely on muscles a lot so their natural state is just enough to jump around and run fast.\n\nEDIT: Fixed link. EDIT2: Spelling."
]
} | [] | [] | [
[],
[],
[
"https://www.scientificamerican.com/article/why-do-cats-purr/"
],
[],
[
"http://kids.nationalgeographic.com/content/dam/kids/photos/animals/Mammals/A-G/gibbon-tan-18778051.jpg",
"http://i.imgur.com/jz1kBTb.png",
"http://www.tvagro.pl/data/catalogue/belgian-blue.jpg"
]
] |
||
37tihf | why don't we just use two or more different antibiotics, with different ingredients to kill off 100% of bacteria | If they really do kill 99.9% of all bacteria and we use like 5 different kinds of antibiotics wouldn't the chances of them surviving and resisting all those antibiotics be very slim? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/37tihf/eli5_why_dont_we_just_use_two_or_more_different/ | {
"a_id": [
"crppotg",
"crppxmg",
"crpq6lw",
"crpq9b9"
],
"score": [
5,
6,
3,
3
],
"text": [
"Well antibitoics don't all target the same things. But even if the did, it would be a terrible idea to try. Because if any of the bacteria live? They now have a resistance to all of those antibiotics, instead of just one or two.",
"We do. Antibiotic cocktails are quite common when resistance is suspected. But as /u/sablemint notes, any survivors - and there are likely to be some - then develop resistance more quickly.",
"Not trolling, but your question is too general. Bacteria exists in so many different places, inside your body and outside your body. Not all bacteria are harmful to humans, in fact some are beneficial. If you killed off all the bacteria in or on the human body, then fungus would take over the surface area inside and out, because bacteria are no longer present to compete for food. Then you would have a fungal infection and that can kill you as much as a bacterial infection. Here's a link to a 12 minute video that might help you out.\n _URL_0_",
"Simplest answer: most bacteria is in no way harmful to you. A decent amount is actually helpful. If we killed off all bacteria, we'd lose our ability to digest food (or at least make it a lot less comfortable)\n\nSo even if we could, it would be a very bad idea. In other news, most forms of radiation are also harmless."
]
} | [] | [] | [
[],
[],
[
"http://youtu.be/vAR47-g6tlA"
],
[]
] |
|
1ebayp | how do different sound waves of the same wavelengths carry a different timbre? | I understand how different wavelengths create different pitches and that different materials, densities etc. can create a different timbre. I just don't understand how two sound waves of the same length could carry them.
Thanks. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ebayp/eli5_how_do_different_sound_waves_of_the_same/ | {
"a_id": [
"c9yjm9x",
"c9yqva6"
],
"score": [
3,
4
],
"text": [
"The shape of the wave affects its sound, or timbre.\n\nThere are some examples [here](_URL_0_). (I don't think the instrument names next to the waves are correct... but it gives you the right idea.)",
"There is a big difference between 'wavelength' and 'pitch'.\n\nAll sounds are made up of many pure sine waves overlaped on top of eachother. A pure sine wave is what you here when you strike a tuning fork. \n\nPitch means a note, like C# or D. Each note corresponds to a specific wavelength. But again, the sounds you hear in every day life are made of many of these wavelengths mixed together. \n\nSomething you perceive as a note with a specific pitch is a mixture dominated by a specific wavelength. But, there is still a whole mix of other wavelengths on top of that. That extra mixture is what makes a C# on a piano sound different than the same C# on a flute.\n\nA sound without a specific pitch, like a crashing wave, has a pretty much even mixture of all wavelengths. This is also know as 'white noise' as analogous to white light.\n\nTo carry the analogy further, light you see is a mixture of wavelengths of color. All images are a mixture of wavelengths in different positions just like all sounds are mixtures of wavelengths at different times. This is why a red truck looks different than a red apple; even though they have the same dominate 'tone'.\n\nIf you are interested in explinations which are math intensive and outside the scope of eli5, check out [Fourier Transforms](_URL_0_)\n\ntl;dr \"two sound waves of the same length\" cant carry different sounds, you need a mixture of many different wavelengths."
]
} | [] | [] | [
[
"http://library.thinkquest.org/5116/images/soundwave3.GIF"
],
[
"https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CC4QFjAA&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FFourier_transform&ei=lJSSUa_RGIywqwGu84HgCw&usg=AFQjCNEltUQRoKWb8sbIpb_7BHJdQTUmQg&sig2=h2hj0Ass5-_MYmMnOGgGOQ&bvm=bv.46471029,d.aWM"
]
] |
|
900fcz | why do monotonous noises (like the sound of an alarm clock) begin to sound like it has two different pitches after hearing it for a while? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/900fcz/eli5_why_do_monotonous_noises_like_the_sound_of/ | {
"a_id": [
"e2mt9ea"
],
"score": [
6
],
"text": [
"i think that it may be because of our natural tendency to turn repetitive sounds into melodies. So a repetitive sound gets given different pitches by our brains. Its called the speech to song illusion. "
]
} | [] | [] | [
[]
] |
||
8h9hve | how come many fish were able to survive the great k–pg extinction, but pretty much no sea reptiles (mosasaurs, plesiosaurs, etc) were able to? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8h9hve/eli5_how_come_many_fish_were_able_to_survive_the/ | {
"a_id": [
"dyi28q1",
"dyiov73"
],
"score": [
20,
4
],
"text": [
"It takes a LOT of food and a very balanced ecosystem to keep a giant alpha predator alive. If the food diminishes or the ecosystem shifts, alpha predators die out pretty easily.",
"Another additional reason. Reptiles are dependent on the surface for air. Fish down deeper might have survived and later expanded and speciated to fill the missing niches near the surface."
]
} | [] | [] | [
[],
[]
] |
||
2w5p7r | how do bank errors leaving customers with extra money happen? | I always see articles where people report to have massive amounts of money 'accidentally' deposited into their accounts. For example- [this article](_URL_0_).
My grandmother last week also had an extra $1000 given to her in cash, which she had to return to the bank.
My question it- how does this happen? I always assumed banks had incredibly strict systems which would prevent this sort of thing. Does someone actually lose money as you gain it- or does the bank just 'create' an extra amount due to math errors?
Also- if you did withdraw and use the money completely, how is this against the law? I get that it is not your money, but it was the bank's error. Is there any way to keep some of it? If you discovered a fortune in your account, what would you do? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2w5p7r/eli5how_do_bank_errors_leaving_customers_with/ | {
"a_id": [
"conu93l"
],
"score": [
2
],
"text": [
"I have this saying: \"As long as humans are involved, there will be human error.\" \n \nSimple as that - someone at the bank done goofed. You are right - banks *do* have incredibly strict controls to prevent errors, but as long as human beings are punching keys and inputting information, there's going to be human error on occasion. \n \nI remember one time a customer called in to say that he noticed he had an extra $50,000 in his account, wondered where it came from. Did some digging around through our systems, and figured it out. A third party had walked into a branch to make a deposit into his friend's account, didn't have the account number handy so the teller looked it up by the account holder's name. Even though it was a fairly uncommon name, our bank had *two* customers with the same name. Guess where the money went? \n \nIt was an easy enough fix, and it did not cause any problems with the other customer, but it is still clearly a bank error. Very, very rare (I've seen it maybe twice), but it does happen. \n \nAnother more common error I see is \"check encoding errors\", where someone is manually typing in the information from the checks and types in some digits wrong - such as transposing two numbers, and the money ends up in the wrong account. I see that a few times a year. \n \nBasically, as long as human beings are part of the process of handling the transactions, there will be errors. The error rate is extremely low, but our bank processes several billion individual transactions each day, so a few creep into the system here and there. \n \n > Also- if you did withdraw and use the money completely, how is this against the law? \n \nWell, no, you can't keep it. In the terms and account agreements that you agree to when you open your account, there are disclaimers about bank errors. Pretty much every bank, credit union or financial institution will have a disclaimer about the bank's ability to make corrections, and that you would be responsible for returning any misapplied funds. "
]
} | [] | [
"http://www.bbc.com/news/world-asia-pacific-15129689"
] | [
[]
] |
|
45gr6y | why does light/sound propogate as a wave? why not a straight line? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/45gr6y/eli5_why_does_lightsound_propogate_as_a_wave_why/ | {
"a_id": [
"czxr5hs",
"czxtwlu",
"czy2uot"
],
"score": [
16,
2,
3
],
"text": [
"They both do propagate in a straight line just as a wave in the water does. A sound wave or water wave is a varying pressure, not space. And luckily google gave me the answer [from Reddit](_URL_0_) on what varies in a photon: \n\n > The wave is not the path that the photon takes. The wave is a representation of the electromagnetic field associated with that photon.",
"It travels as both, sorta. \nSo there's only a little chance this will be actually understood by a five year old. \nLight (and all energy, therefor matter itself) travels as a probability. What's that really mean though? It means that when you aren't looking at something, there's a chance that it might not exist. For large objects, this chance of not existing is extremely, extremely small. For smaller quantum-level objects, this chance varies. For example, the electrons around a nucleus of an atom exist in certain formations based off which element we're talking about. [See this picture](_URL_1_). These \"areas\" are really just higher probability of the electron existing in that specific region. \nA good thought exercise on this is the ol' [Schrödinger's cat](_URL_0_) thought experiment. Essentially, the cat exists in all viable states (Alive and Dead) at the same time until it is actually observed. When it is observed, the wave function collapses into reality. This really makes no logical sense with something this size. Go down into the smaller level, and it is a very real (and scientifically proven) scenario. \nTake a gander at the [Double Slit Experiment](_URL_3_) for a great example. This [video](_URL_2_) is a good one. The summed up version of that is: Electrons fired through a slit would act as a wave when not being observed. When being observed, they acted like a particle. What really was happening was happening was that the light existed as a wave of probability until it was observed, which then caused it to collapse into a particle. \nThat's my basic understanding of the whole thing, so if any experts exist on there and want to provide some corrections to my answer, please do!",
"Think about it like this:\n \n . . . ... . . . . . . . ... . . . . \n\nThe dots are arranged in a line, yet they carry the information of a wave. When you put them at all angles of a sphere, they represent waves of pressure in 3D. I don't know if this analogy works for light, so keep that in mind."
]
} | [] | [] | [
[
"https://www.reddit.com/r/askscience/comments/2yn2o5/if_photons_travel_along_waves_with_varying/"
],
[
"https://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat",
"http://imgur.com/QaAunvr",
"https://www.youtube.com/watch?v=fwXQjRBLwsQ",
"https://en.wikipedia.org/wiki/Double-slit_experiment"
],
[]
] |
||
4kaii4 | are there gradual forms of depression or is it purely binary? | Specifically, if somebody is generally pessimistic, does it imply that they may just have some very light form of depression, or is that just in the normal realm of human behavior. I'm not asking, though, if everyone that is pessimistic has depression. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4kaii4/eli5_are_there_gradual_forms_of_depression_or_is/ | {
"a_id": [
"d3dfwcj"
],
"score": [
10
],
"text": [
"As someone who is very depressed, it's gradual. Never binary. You have good days, you have bad days."
]
} | [] | [] | [
[]
] |
|
fa95vx | why is it that it's possible to shake a cup with a bunch of dice in it to the point that they can all stack on top of each other? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fa95vx/eli5_why_is_it_that_its_possible_to_shake_a_cup/ | {
"a_id": [
"fiwq7rw"
],
"score": [
4
],
"text": [
"It's not just being shaken randomly. If you'll note, the predominant motion is a circular swinging. What they're doing is forcing the dice to the edge of the cup and getting them to swirl around. If done right, that forces the dice to assume a vertical stack inside the cup. It takes practice of course, but it's no more magic than any physical trick like that."
]
} | [] | [] | [
[]
] |
||
3eofhe | how come putin has the same power in russia now as a prime minister as he had as a president? | Why doesn't current president have the same political power that Putin had as a president? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eofhe/eli5_how_come_putin_has_the_same_power_in_russia/ | {
"a_id": [
"ctgugyt",
"ctgv29g",
"cthad9g"
],
"score": [
9,
6,
3
],
"text": [
"Vladimir Putin *is* the President of Russia. Has been since 2012. Before that he was Prime Minister. Before *that*, he was President. \n\nIt is fairly accepted that he was still running things when he was Prime Minister, though and that the president at the time (Dmitry Medvedev) was merely his puppet. ",
"Being prime minister was a dodge to avoid term limits. The acting president intentionally let Putin make the decisions.",
"Because he's only there because Putin put him there. If he wasn't willing to let Putin make the decisions, Putin would have chosen someone else."
]
} | [] | [] | [
[],
[],
[]
] |
|
o7nee | what are you supposed to do when an emergency vehicle passes you on the opposite side of the road? | If you aren't interfering with them is it ok to not slow down? I'm guessing it's just judgment based on the situation but I'm wondering if there is a specific rule or anything. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/o7nee/eli5_what_are_you_supposed_to_do_when_an/ | {
"a_id": [
"c3f10rh",
"c3f3nl7"
],
"score": [
14,
2
],
"text": [
"If there is a physical obstruction in the median (for example trees, bushes, dirt etc.) then you do not need to do anything but if it is just yellow lines or there is a big enough opening for them to cross onto your side of the road then you should pull over until they pass.\n\nThis is so that if for example traffic is heavy on the other side of the road they can cross over to your side or if the street entrance they have to go into would normally be blocked on their side of the road to get where they need to go.",
"[Move over America](_URL_0_) has the state by state laws. You know, for when you turn 15 and start working toward your licence."
]
} | [] | [] | [
[],
[
"http://www.moveoveramerica.com/"
]
] |
|
9iywvj | what is a generator in electricity? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9iywvj/eli5_what_is_a_generator_in_electricity/ | {
"a_id": [
"e6nh7xg",
"e6nobvc"
],
"score": [
14,
3
],
"text": [
"It's like an *electron pump* that pushes electrons away from one end and toward the other end. This creates a *voltage* (electric pressure) which is then used to power the flow of electricity through wires and other things.",
"I majored in physics and it sounds like these answers are dancing around what is causing the current. \n\nFirst you need a wire. This supplies the electrons that will become a current. In order to make them move you need to have a moving magnetic field. A generator simply uses some fuel to turn a magnet. If the wire (electrons specifically inside the wire) is coiled and inside a continually changing magnetic field it creates an emf (or electromagnetic feild). And bam. Electricity.\n\nThese forces are always tethered. Moving charged partials will in turn create magnetic fields. Hope this helps."
]
} | [] | [] | [
[],
[]
] |
||
6jc1bw | why are media companies so obsessive about pirating movies or music online, when just a few years ago people would record movies off of tv or music from the radio and it wasn't a big deal? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6jc1bw/eli5_why_are_media_companies_so_obsessive_about/ | {
"a_id": [
"djd4btc",
"djd4pd2"
],
"score": [
2,
2
],
"text": [
"They were making a big deal about it then, that's why they would put in warnings and videos about piracy, but they had to crackdown harder on internet privacy because the ease of it caused piracy numbers to skyrocket creating a bigger problem",
"Back in the 70's and 80' a small portion of every cassette tape went to the music industry. I'm not sure about VHS."
]
} | [] | [] | [
[],
[]
] |
||
42iokp | many american football players have brain diseases in their old age because they have so many concussions during their career. why don't rugby players, who don't wear helmets, have this problem? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/42iokp/eli5_many_american_football_players_have_brain/ | {
"a_id": [
"czan4am",
"czan6qa",
"czar41t",
"czaummg",
"czavw9n",
"czay28f",
"czayuua",
"czb0xgc"
],
"score": [
79,
7,
4,
28,
2,
20,
5,
5
],
"text": [
"Because American Football players wear helmets and protective armor, they regularly crash into each other way more violently than rugby players would, leading to the apparently paradoxical effect that football players' \"protection\" actually make the sport more dangerous. \n\nIn a similar case, the introduction of soft, cushy gloves in boxing has lead to significantly more deaths in boxing matches, since boxers were now able to hit their opponent's head with great force without breaking their own hands.",
"They do have the same problem. But the research was done on football players so that's what we're talking about. ",
"I used to wonder this as well until I started watching rugby. When they \"tackle\" each other to the ground it's more like an aggressive wrestle. ",
"I work in big time college football and \"rugby tackling\" is so hot right now. Pete Carroll of the Seahawks has been teaching this for as long as I can remember (here's a video if anyone is interested _URL_1_). \n\nLike others have state here the hard helmet and facemask give the player the illusion that they are protected. Vicis is a new company with a soft helmet that is trying to keep the helmet (and violence of the game that's so popular) and increase the safety of the player (here's their website with a fantastic promo if anyone is interested _URL_0_).",
"It's all about the tackling and how they are trained to tackle. Far less head injuries in rugby",
"I was curious if there had been any studies done on concussions in rugby. Here are some articles that actually compare football to rugby.\n\n_URL_3_\n\n_URL_1_\n\n_URL_0_\n\n_URL_2_\n\ntl;dr: concussions are very common in rugby, at a comparable rate to the NFL. Also, never race horses.\n\n*edit: missed \"rate\" in the last line",
"[Risk Compensation](_URL_0_) \n\nBasically people will take more risks if they feel safer, or less risk if they feel more vulnerable.",
"There are a few reasons, many of which are covered in length here, but also:\nTackling above the shoulder in rugby is a big no-no. This is great way to get sent off the field, while the other guy gets sent to the hospital.\n\nIt has been my experience that -apart from the usual vicious rivalries- rugby players have a sense of brotherhood and innate respect for anyone who is willing to lace up their boots and play. Yeah you want to knock that guy on his ass, but you also want to drink some beer with him after, and then play some more rugby with him. It is much less fun to do that if you or he are concussed. Sportsmanship exists in football, but it is a much more integral part of rugby.\n\nExcessive violence is generally highly celebrated in football, and discouraged in rugby. If you \"ring someone's bell\" in football you get a slap on the ass and a sticker on your helmet after the game. In Rugby you can get penalized or yellow/red carded.\nIt is also very likely that you put a bullseye on your own back. My former rugby team had a play known as \"Fuck that Guy\" if someone on the other team was punching, kicking or otherwise playing violently and not getting a stern talking to from the ref, we would, whenever the ref wasn't looking would pull hair, eye gouge, rake (stepping on him and then dragging your cleats across his body) or punch him, until he got the message or limped off the field.\n\n"
]
} | [] | [] | [
[],
[],
[],
[
"http://vicis.com",
"https://www.youtube.com/watch?v=tOCtUFwxsFU"
],
[],
[
"http://www.theguardian.com/sport/shortcuts/2013/jan/28/american-football-rugby-more-dangerous",
"http://www.bloomberg.com/news/articles/2015-03-20/rugby-is-having-an-nfl-moment-as-concussions-bring-legal-scrutiny",
"http://www.englandrugby.com/mm/Document/MyRugby/Headcase/01/30/54/78/Concussioninrugby_Neutral.pdf",
"http://www.brain-injury-law-center.com/latest-news/head-injuries-rugby-vs-football/"
],
[
"https://en.m.wikipedia.org/wiki/Risk_compensation"
],
[]
] |
||
4w3km1 | if i have an electrical circuit, run a current through it, and then suddenly interrupt the circuit, what happens to the electricity still within the circuit? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4w3km1/eli5_if_i_have_an_electrical_circuit_run_a/ | {
"a_id": [
"d63onoq",
"d63pbmy",
"d63ruvo",
"d63wefm",
"d643888",
"d6455eg"
],
"score": [
63,
4,
9,
2,
2,
2
],
"text": [
"Imagine a channel of water. On one end you pump in water, on the other end you suck water away. Imagine that you suddenly stop doing both. The water briefly builds up due to leftover inertia and then it stops moving.\n\nSame thing in a circuit. The electrons are slowly moving through your circuit. If you interrupt it the electrons stop moving. Electricity is the movement of the electrons in one direction, not the electrons themselves.\n\nThe brief buildup also has an equivalent in electricity, inductance in electrical circuits is equivalent to inertia in water flows. So if you take a big coil (lots of inductance) and you suddenly interrupt a current flowing through it you get a pretty damn big spark. That's how spark plugs in your car work.",
"If you are talking about a simple circuit, the simple answer is nothing happens to it, it just stops flowing. \n\nElectricity is the flow of electrons. Voltage is how hard the electrons are being pushed. When you apply voltage to an electron it moves. This movement is what is referred to as electricity. When you interrupt the circuit it no longer has anywhere to go, so it stops moving. \n\nIt's like when you turn your water off at a sink, the water is still in the pipes, but now that you've closed the valve, the water has no where to go so it stops moving. ",
"Some great answers, but what I feel you have to realize is that the 'electricity' or electrons are present whether or not you're running a current. It's not like an empty channel; the electrons were present before the current and never changed appreciably. Some moved in at one end and some moved out at the other. That's all.",
"An electrical circuit has a property called inductance. While resistance is the property of a conductor that opposes current, inductance is the property of a conductor that opposes *changes* in current. Without going into much detail, it's caused by the magnetic field around the conductor created by the current going through it.\n\nThere's a good water analogy for this. Imagine a pump and loop of pipe with a large water turbine in it. The pump starts running and the water slowly starts flowing faster and faster as the big turbine with a lot of inertia starts spinning faster and faster. When you shut the pump off the turbine is still spinning and wants to keep spinning because of it's inertia. The spinning turbine now acts as a pump itself and forces the water through the loop. If there is a restriction to the flow, the pipe or pump may burst.\n\nIn the actual electrical circuit the inductance wants to keep the current going, and if the circuit is broken suddenly, it may even arc over the switch contacts. This is analogous to the turbine bursting the pipe.",
"In reality electricity is not quantifiable like this question appears to assume, there are also a lot of transient effects that can happen when you go from a completed circuit to an interrupted circuit. For the sake of answering this i will assume that we go from a completed circuit to a disconnected circuit at steady state.\n\nIf we think of electricity as energy (as in what your utility company charges you for) then electricity must be measured over a length of time. You don't have a volume of it like you would have a volume of water in a glass.\n\nWhat is generally used to quantify electricity is kWh (kilo Watt-hours) which is a measurement of power over a length of time. Power is itself defined as Voltage times Current.\n\nEnergy = V * I * t\n\nFrom the equation we can immediately see that when we interrupt the circuit and current goes to 0 we have 0 real energy. What is left is the electrical potential, or Voltage.\n\nThe voltage of the circuit will change on both sides at the disconnect on the circuit. While the circuit is connected the length of the circuit will have a voltage gradient where the measured voltage will vary along the entire length of the circuit from the source voltage all the way down to 0. Once the circuit has been interrupted, the positive side of the disconnect will rise up to the source voltage, while the negative side will drop down to 0. Essentially the voltage will be flat, across the length of the circuit, with the disconnected points acting as the change from source voltage, to no voltage.\n\nSo in short when you interrupt the circuit you go from a real energy being used to a potential energy that is available. The potential energy available ends up being whatever your source can provide. \n\n\n\n\n\n\n",
"There is a ton of misinformation here, but there is really no ELI5 way to accurately describe electricity. Electricity is not just the \"flow of electrons.\" In fact, electricity cannot adequately be described using any single definition. \n\nElectrons do move in a conductor, but they do not \"flow\" like water through a channel. In DC circuits, electrons move from negative to positive, albeit very slowly (inches per minute). In AC circuits, they just wiggle back and forth but don't actually flow at all. \n\n/u/GlamRockDave was correct in stating the water analogy is misleading, but he's gotten downvoted on every post for trying to point out the common misconceptions. I'm sure I'll be downvoted as well, but I can live with that. "
]
} | [] | [] | [
[],
[],
[],
[],
[],
[]
] |
||
3hjlns | what happens during an internet outage? | When broadband subscribers are left unable to connect to the internet, what is happening behind the scenes? How do ISPs deal with an outage and what is actually happening to infrastructure? How can a storm affect the possibility of an outage? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3hjlns/eli5what_happens_during_an_internet_outage/ | {
"a_id": [
"cu7zivi",
"cu83178"
],
"score": [
2,
2
],
"text": [
"There can be a million reasons ... The chain from you to the data center is: PC -- > LAN -- > Router/Modem -- > Landline/cable/fibre to some more central place (plus converters) -- > Another Router/Modem -- > fatter line to data center -- > [more hardware] -- > interconnection with other ISPs -- > repeat until you reach your destination page.\n\nliterally anything in that chain can break or in the case of routers be misconfigured.",
"There'll be people working out where the problem lies, and how to fix it.\n\nThere's a lot of equipment involved in connecting you to the internet. The more important connections and devices in the chain are \"redundant\", where there will be a backup that can take over fully if the primary system fails (hopefully that has been tested to ensure that it does take over). Others are not redundant - if they fail, they will cause an outage.\n\nAn outage could be caused by lots of things. It could be as simple as a misconfiguration somewhere, to a building being on fire or flooded or has lost power. There's even been outages caused because of burglary - someone broke into a facility and literally stole the network equipment\n\nAny ISP worth their salt will have tons of monitoring on everything they can monitor, so as soon as something fails, they know what appears to have failed and can try to fix it. Hopefully it's something that has a backup, so it can be fixed or replaced calmly, rather than causing a massive outage that needs immediate attention and needs to be fixed yesterday\n\nStorms could take out equipment (for cable or DSL there may be equipment in your neighbourhood that won't like a lightning strike, or if they lose power), or maybe they damage the cables themselves"
]
} | [] | [] | [
[],
[]
] |
|
bzamp4 | why do instruments sound different if sound is just vibrating air? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bzamp4/eli5why_do_instruments_sound_different_if_sound/ | {
"a_id": [
"eqr56us"
],
"score": [
7
],
"text": [
"It all has to do with what they call timbre.\n\nDifferent instruments may be capable of playing the same note or pitch, but they all do it differently. Not only is the pitch (or frequency of the note) being sounded, but also other frequencies get sounded, too. These might be overtones, or multiples of the intended frequency, or other non-multiple frequencies. Which additional frequencies are sounded, and their relative strengths compared to the pitch frequency, color the overall sound. That is the instrument’s timbre.\n\nThe timbre is a function of many properties of the instrument. An instrument that creates sound through cavity resonance, like a clarinet, will excite different frequencies than an instrument that creates sound through vibrating a string, like an electric guitar. And then different models of the same instrument can excite different frequencies through the use of different materials, or different playing skills, or slight changes in design, etc.\n\nHope this helps!"
]
} | [] | [] | [
[]
] |
||
6m0ytn | there are people who claim that drinking beer gives them a "happy-go-lucky" drunk, but drinking whiskey or liquor makes them a "mean" drunk. what could cause this? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6m0ytn/eli5_there_are_people_who_claim_that_drinking/ | {
"a_id": [
"djy2pr1",
"djy2r8g"
],
"score": [
2,
2
],
"text": [
"It's mostly due to accelerated drunkenness. 1 shot of 80 proof liquor is roughly equivalent to 1 beer. So taking a shot is like drinking a whole beer in a matter of seconds. Even if you sip liquor, most people will end up drinking it faster if you are out with the boyz. So people that claim that a certain liquor makes them act a certain way probably just got drunk faster than they expected. ",
"The active ingredient in all of these beverages is alcohol, specifically ethanol, also known as ethyl alcohol. The only real difference between getting drunk via beer vs. getting drunk via \"spirits\" (whiskey, and other liquors, are also known as spirits) is that the alcohol in spirits is more concentrated, so the beverage is smaller, so one can consume it faster, then consume one beverage after another, and therefore get intoxicated faster. But people *expect* different beverages to have different effects, so they behave accordingly. It's a myth. Alcohol is alcohol."
]
} | [] | [] | [
[],
[]
] |
||
2s9bxp | why isn't the data on a black box saved 'in the cloud'? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2s9bxp/eli5_why_isnt_the_data_on_a_black_box_saved_in/ | {
"a_id": [
"cnndk13",
"cnndksd",
"cnnekww"
],
"score": [
11,
6,
3
],
"text": [
"Some of the newer devices can upload data, but it's a recent development that hasn't yet spread to every airline in every territory.\n\nIt's a lot of data to push, if you don't have a good connection. Many planes just don't have that sort of bandwidth.",
"No doubt it will be one day.\n\nYou'd probably need a dedicated satellite constellation to do it though. Very high cost that no one airline would ever front.",
"Because all you care about is the last 5 minutes and that's not going to upload during a crash."
]
} | [] | [] | [
[],
[],
[]
] |
||
4a183y | if there are over 7 billion people in the world & only a limited number of features on the face (eyes, nose, chin, etc.)that can determine how a person looks, why is it that almost everyone looks different? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4a183y/eli5if_there_are_over_7_billion_people_in_the/ | {
"a_id": [
"d0wjxrn",
"d0wk65e",
"d0wrddh"
],
"score": [
4,
2,
2
],
"text": [
"There may be a limited number of features on human face, but there is a near infinite number of tiny changes you can make to them. \n\nSubtle changes in size, shape, and position of each of the individual features all add up to give everyone their own unique look.\n\nRecognizing faces is immensely important for non-verbal human communication, as well as being able to identify friends and family, and therefore the human brain evolved to be very, very good at facial recognition. ",
"There's probably like a billion different 'face combinations' (?), people with wide eyes, different shape face, nose, ears, mouth, eyebrows, different colour eyes, skin tone, hair. Im assuming if two people looked exactly the same, changing just their eye colour/hair or position of their mouth will probably make them look 'completely' different",
"Because you don't know seven billion people. In fact, you probably don't even know a million either, maybe a few thousands. So, you know a few thousands different faces, that's not a lot. If we had ten kinds of nose, ten kinds of mouth and ten different hairstyles that's 1000 faces already. Surely there's more kinds of variation. \nNow, if you actually knew a billion people, I'm sure you'd find some almost identical, beyond human capacity to distinguish. "
]
} | [] | [] | [
[],
[],
[]
] |
||
1uixqj | when big movie producers send out movies to be reviewed by critics, shouldn't it be easy to catch who uploaded the dvdscr? | I hate to be a paranoid parrot, but what's stopping them from sending slightly different copies to different reviewers? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1uixqj/eli5_when_big_movie_producers_send_out_movies_to/ | {
"a_id": [
"ceil6j1"
],
"score": [
2
],
"text": [
"It's a decent idea.\n\nAmazon tried to do something simillar for their e-book sale, they thought of placing 1-2 random spelling mistakes in each one, to see who uploaded something at a torrent tracker. But eventually they abandoned the plan. \n\nI'm not answering your question though :( "
]
} | [] | [] | [
[]
] |
|
3qtynz | why are fruits that can be grown on the east coast so much more expensive to purchase than produce in california? | Some fruits like avocados make sense why it's cheaper in California but what about fruits like apples that can be grown closeby, thus not requiring much middle men for transportation and stuff which would increase the price | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3qtynz/eli5_why_are_fruits_that_can_be_grown_on_the_east/ | {
"a_id": [
"cwia7g3",
"cwic0xe",
"cwihyen"
],
"score": [
3,
20,
2
],
"text": [
"Transport is basically cheap. You might add a nickel a pound to transport a truckload across the country.\n\nTransporting by ship might be a nickel a ton per thousand miles.",
"/u/friend1949 explained why the shipping costs don't add significantly to the price, but that doesn't explain why the east coast produce is *more* expensive.\n\nPart of the answer is that the farms on the east coast are smaller, and don't have the economies of scale. But also locally grown produce is *perceived* as being better, thus allowing stores to charge more. It *is* better in many cases, but the perception is what's important and that applies across the board. Two well known examples of being better are fresh picked strawberries and tomatoes. (I think it was Garrison Keillor who described the pink, flavorless, mass-produced tomatoes as \"strip mined.\")\n\nApples, which you mentioned, are more interesting because they have names attached to their varieties, some of which are well-known trademarks, valuable as such. Most of the Oregon apples that I see on the east coast are Red Delicious - consistent, predictable, with a long shelf life, and a slightly sweet but bland flavor. Kids are very happy with them, but all it took was one trip to a Pennsylvania apple orchard during apple season to show me how boring they are.\n\nCompare that to Honeycrisp, a more recent variety that's both patented and trademarked by the University of Minnesota. (According to Wikipedia, the patent has expired in the US, and the trademark may be at risk.) It's usually sweeter than the better known varieties, has a bit more flavor, and decent shelf life. For whatever reason, their marketing has been successful and it commands a premium (often a dollar per pound more in the stores I frequent compared to other north east varieties). \n\nI also tried some Sweet Tango apples this year. This is a newer variety, also from U. Minn, and descended from the Honeycrisp. But, in spite of having much smaller supplies, it was cheaper than the Honeycrisp. Why? Because it's not as well known. Maybe someday it will be. ",
"Supply and demand. California farming operations are on an industrialized scale, and some fruits and vegetables are produced in multiple growing seasons a year. Fruits and vegetables produced in California are grown for the whole country, while a lot of east coast farms are geared towards local distribution, thus California markets are saturated with extra product year around, decreasing their value in local markets."
]
} | [] | [] | [
[],
[],
[]
] |
|
5wo9y2 | why can't you compress a rar file with rar or zip? | Why can't you compress a RAR file, | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5wo9y2/eli5_why_cant_you_compress_a_rar_file_with_rar_or/ | {
"a_id": [
"debkofi",
"debksh3"
],
"score": [
5,
2
],
"text": [
"Compression is a technique for finding patterns in a file and writing it in a way that takes more space. For example instead of writing \"aaaaaaaa\" you may write 8*\"a\" which is much shorter. Or instead of writing \"abcdefgh\" you may write \"a\"-\"h\". However if you have already compressed a file and written it in the shortest way you can think of then another compression program will not have much luck trying to compress it further.\n\nIf you think of your file as a sponge. It consists of a sponge material and a lot of air. This is practical for cleaning but not very practical for transport. So you put in though a vacuum sealing machine to suck all the air out and put on a plastic seal to keep all the air out. Now the sponge is much smaller. But you read of another way to do it by using a vice. However when you put the already compressed sponge in the vice you can not get it much smaller. This is like trying to compress an already compressed file.",
"Software developer here,\n\nCompression works by reducing repetition. So if you're compressing \"aaaaaaabbbb\", it would look something like \"7a4b\", for example. There's not much else to reduce there. This is, of course, a simplistic example of compression. More sophisticated algorithms will perform a series of matrix transforms (arrange the data into rows and columns, then start rotating rows and columns like a rubix cube, or change the values in a mathematical way) in order to align the data into bigger sets of repeating sequences, and then reduce that similar to my example above. The output is the transformed and reduced data, and a matrix to transform the data back to it's original form. But in the end, there's just nothing more to reduce, and you end up with a larger file because you have to store the meta-data for the encompassing compression format."
]
} | [] | [] | [
[],
[]
] |
|
313f15 | how does diet coke cause cancer? was that just media hype for a while, or is there legitimacy behind it? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/313f15/eli5_how_does_diet_coke_cause_cancer_was_that/ | {
"a_id": [
"cpy3fl2",
"cpy3hvd"
],
"score": [
27,
2
],
"text": [
"Diet Coke contains Aspartame, which is an artificial sweetener that many people believed for a long time helped contribute to cancer, specifically brain cancer.\n\nWhile there are people that will argue this is true and swear by it, the overwhelming majority of the medical industry believes that it is not carcinogenic in any way if consumed at levels that are likely in everyday life.\n\nThis is intuitive because Aspartame breaks down into Aspartic Acid, Methanol, and Phenylalanine in your small intestine before it is absorbed into your blood stream. All 3 of these things are likely to be found in higher concentrations after you eat a steak, for example. So unless you think steak causes cancer, it isn't any more likely that Aspartame does.\n\nPlease don't confuse this as saying that Aspartame is completely harmless, or that it's even effective as a dieting aid; it just doesn't cause cancer.\n\n\nTL;DR Either steak causes cancer too, or neither do",
"It contains Saccharin and Aspartame/Neotame sweetners.\n\naspartame was found to cause cancer in rodents in the 70s those results are disputed and it is considered OK for humans"
]
} | [] | [] | [
[],
[]
] |
||
fh3muh | clueless about economics. how will the dow dropping 1,400+ points today and a potential recesssion/etc affect everday working people like me? those who aren't wealthy. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fh3muh/eli5_clueless_about_economics_how_will_the_dow/ | {
"a_id": [
"fk8l5e9",
"fk8l8vy"
],
"score": [
2,
4
],
"text": [
"Jobs may begin to slow down due to worry or lack of funding. Because of this your employer may limit hours or lay people off.",
"Immediately, it won't, outside of any 401k you may have. If the market rebounds within a month or so, you probably won't see much impact overall. If the drop lingers, then you can see potential layoffs and reduced hours from employers."
]
} | [] | [] | [
[],
[]
] |
||
3c9nat | what is this 'google dream code' thing i keep seeing every where and what is it used for? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3c9nat/eli5_what_is_this_google_dream_code_thing_i_keep/ | {
"a_id": [
"cstjry5"
],
"score": [
2
],
"text": [
"Think of your own brain, and imagine you are five (slaps knee), lying down on a field of grass looking up at all of the funny shaped clouds in the sky.\n\nYou notice one cloud looks like something, but you can't quite put your finger on it. You think of every single thing you've ever seen in your life that kind of looks like this cloud, and naturally, this takes you awhile because you're young. Finally, after a bit, you realize that this cloud looks like a dog! So you start imagining dogs in all of the funny scenarios you've seen them in, until you notice another cloud you want to think about next. \n\nThis is a pretty good analogy of what's going on in [Google's DeepDream project](_URL_1_). Essentially, Google made an [artificial brain](_URL_3_) modeled after our own and is testing how much this brain knows by feeding it \"cloud images\" and seeing what it thinks about. You know how you thought that cloud looked like a dog? Well, perhaps at five years old, you were really into dogs and hence know a lot about them. Same thing with DeepDream: If you give it a \"cloud image\" and it outputs a bird-like image, then you know that this artificial brain in particular must be \"trained\" to know what birds look like, especially if you have a bird-like cloud in your cloud image.\n\nThe important thing to realize is that these \"cloud images\" do NOT have to be pictures of clouds! They can be anything: a selfie of yourself, a landscape picture, etc. The artificial brain will essentially just emphasize the features it's been trained to recognize. If you look at the [example gallery](_URL_0_), you can see some pretty psychedelic results. The purpose of this project is mainly for researching and improving these artificial brains, and making them better for more applicable things in the future.\n\n**TL;DR** Google made a robot brain and is seeing what it recognizes by giving it \"cloud images\", and examining the results so they can make the brains better.\n\n[Google gives a more complicated and thorough explanation of all of this in their research blog!](_URL_2_)\n\n"
]
} | [] | [] | [
[
"https://photos.google.com/share/AF1QipPX0SCl7OzWilt9LnuQliattX4OUCj_8EP65_cTVnBmS1jnYgsGQAieQUc1VQWdgQ?key=aVBxWjhwSzg2RjJWLWRuVFBBZEN1d205bUdEMnhB",
"https://github.com/google/deepdream",
"http://googleresearch.blogspot.ch/2015/06/inceptionism-going-deeper-into-neural.html",
"https://en.wikipedia.org/wiki/Artificial_neural_network"
]
] |
||
6o0xcl | if california's housing market is already incredibly overpriced, why does it keep rising? | The median cost of a home in Cali is now more than twice the national average and homelessness is rising, how is demand still surging? Aren't they running out of middle-class homebuyers? Are they used as income properties or other form of investment? Please explain. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6o0xcl/eli5_if_californias_housing_market_is_already/ | {
"a_id": [
"dkdosfd",
"dkdoz20",
"dkdse6c",
"dkdslp8",
"dkdt3h3"
],
"score": [
7,
2,
2,
18,
7
],
"text": [
"Because the economy is still very strong, particularly in the Bay Area, people keep moving there. Home prices will drop once people stop wanting to move to California",
"The core places that have growing home prices (commute-ready homes in San Francisco, fashionable areas of LA, beach property) are limited in their supply and have a continuously growing number of wealthy people wanting to buy them.\n\nAs an example, lets look at San Francisco: The city has a fixed size because of the land it's on, and only a certain number of homes are within a reasonable commute time of the downtown core. S.F. also has very restrictive zoning laws, meaning new high rises are very difficult to build. With that, only a certain number of people can live within a comfortable commuting distance of their jobs.\n\nS.F. is also a hotbed of technology, a very high growth and lucrative field to be in. People are able to make a lot of money at it, and more people want to move to the area to join in on that business.\n\nMore money floods into the area, but there aren't homes for them. So, the people with money get into a bidding war driving up overall home cost.",
"Uneven distribution of income... there are a selection of the population doing very well, making high incomes, seeing their stocks/options appreciate in value. And high earners tend to marry other high earners, doubling down on their buying power. And they are willing and able to bid up prices for housing in the most in-demand areas. This has a snowball effect, as prices rise in SF and LA then it impacts everything further and cheaper as people have to move further away to afford anything. The issue is that there is still way less supply than there is demand so there are more buyers (or potential buyers) than there are homes being built. Thus people are often spending more than budget guidelines suggest one should spend on housing, cutting spending elsewhere or taking on additional debt.",
"Supply and demand. More people want to live there than there are places to live. \n\nThe two obvious next questions are \"Why is the supply so low?\" and \"Why is the demand so high?\". \n\n**Why is the Supply so low?**\n\nShort answer: Few people actually want it to rise. \n\nThe current homeowners don't, because their home price keeps going up with less competition. A lot of the \"original\" residents don't, because they want the city to retain it's quaint, artistic charm and not be dominated by skyscrapers. The will of these people is expressed in restrictive regulations, and because of them, the only new housing that makes money is luxury housing. (Because if a place is expensive to build, it will be expensive to rent.) People rebel against this, dragging it out in court for years or just torching the construction sites, so the supply is not keeping up with the demand. The root cause is frankly that a lot of people there don't understand or believe basic economics. There's actually no such thing as a \"luxury house\". (You can buy a mansion in Detroit for $1.) It's all just supply and demand, and by preventing new housing from being built, _every_ house is turning into a \"luxury house.\" A normal-looking 1 bedroom, 900sqft single-family home in the city recently sold for $3 million.\n\n**Why is the Demand so high?**\n\nThe tech industry and foreign investors. \n\nTech pays big bucks and is still booming. The average starting salary is $90k and I personally know a guy who took a $400k pay CUT in order to work in a cooler part of the industry. People there are loaded. \n\nForeign investors have also jumped in, raising the demand even more. They see the problems with the supply of housing, so it's a no-brainer to invest. \n\nSo there's tons of demand and the supply can't keep up. This makes prices ridiculous.",
"Prop 13 also has distorted the market significantly. You can find dozens of articles about it, but it effectively freezes property taxes to time of purchase as opposed to annual assessment. This incentivizes home owners to not sell because a house bought many years ago is a huge tax shelter. This also causes shenanigans like creating shell companies so that no more than one party \"owns\" more than 50% of a property to keep the property tax bill low. \n\nMalcolm Gladwell gives a fun example of this regarding LA golf courses. They pay a tiny fraction of the taxes normally owed on the value of their property. Revisionist History - A Good Walk Spoiled: _URL_0_"
]
} | [] | [] | [
[],
[],
[],
[],
[
"http://leopard.megaphone.fm/PPY3090271787.mp3"
]
] |
|
e7wo35 | when two tvs in tvs same house are run through the same cable service, why does one seem to always lag behind the other? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e7wo35/eli5_when_two_tvs_in_tvs_same_house_are_run/ | {
"a_id": [
"fa6ot6y"
],
"score": [
3
],
"text": [
"A modern TV contains electronics which decode the digital HDMI signal and then turn it back into a picture and sound. Unfortunately these usually introduce a delay, and on some models it can be a notable fraction of a second, and it's not a standardized amount."
]
} | [] | [] | [
[]
] |
||
mqh35 | why can't leaded engines use unleaded petrol? | I've asked this question for years, and I have gotten two different answers for it. One is that the lead lubricates the cylinder walls, and the other is that the lead reduces the temperature of the burn, allowing the engine to run cooler. Is either of these correct, or is there a different answer? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/mqh35/why_cant_leaded_engines_use_unleaded_petrol/ | {
"a_id": [
"c332n9e",
"c332n9e"
],
"score": [
3,
3
],
"text": [
"Neither of those is correct. The leaded gasoline vapor can be compressed more than unleaded without spontaneously exploding due to the temperature increase. The compression ratio is determined by engine geometry, so an engine designed for leaded gas will compress unleaded gas to the point where it spontaneously ignites, throwing off the cycle and damaging the engine.\n\nEDIT: I didn't explain why they would design for such a high compression ratio. A higher compression ratio generally allows you to be more efficient and cleaner. However, most governments have decided that these benefits do not outweigh the negatives of putting a ridiculous amount of lead in the air.",
"Neither of those is correct. The leaded gasoline vapor can be compressed more than unleaded without spontaneously exploding due to the temperature increase. The compression ratio is determined by engine geometry, so an engine designed for leaded gas will compress unleaded gas to the point where it spontaneously ignites, throwing off the cycle and damaging the engine.\n\nEDIT: I didn't explain why they would design for such a high compression ratio. A higher compression ratio generally allows you to be more efficient and cleaner. However, most governments have decided that these benefits do not outweigh the negatives of putting a ridiculous amount of lead in the air."
]
} | [] | [] | [
[],
[]
] |
|
8vxu8d | why does our heartbeat and blood pressure lower in our sleep and why is it important for our body to do so? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8vxu8d/eli5_why_does_our_heartbeat_and_blood_pressure/ | {
"a_id": [
"e1rfjfd"
],
"score": [
2
],
"text": [
"* You are lying down. It takes more effort for your heart to pump blood straight up to your brain than it takes to pump when your whole body is horizontal\n\n* Your muscles aren't moving during sleep so they requires less blood\n\n* Your brain uses just as much blood/oxygen when sleeping as when awake"
]
} | [] | [] | [
[]
] |
||
79w7et | what does aspirin do that helps prevent heart attacks, stroke and now cancer? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/79w7et/eli5_what_does_aspirin_do_that_helps_prevent/ | {
"a_id": [
"dp6hisl",
"dp90mv8",
"dp57yg0",
"dp58cj9",
"dp598p7"
],
"score": [
2,
2,
8,
3,
4
],
"text": [
"One observation is that some cancers are linked to inflammation. Aspirin may reduce certain kinds of inflammation.",
"Chronic inflammation promotes cell proliferation, which increases the chances of DNA damage. Aspirin is an NSAID (non-steroidal anti-inflammatory drug) so taking it at low doses will help prevent inflammation, which decreases the probability of DNA damage occurring.",
"For the heart attacks and stroke risks: aspirin thins out your blood, lowering the stress on the veins and arteries.",
"Blood clots can cause blockages in the arteries that bring blood and oxygen to the heart and brain leading to either heart attacks or strokes. Aspirin can help in preventing this by thinning the blood and preventing the blood from even clotting. As for how it can prevent cancers i'm not entirely sure, maybe by preventing the clots from forming you can prevent chronic complication from even happening in the first place.",
"The theory is that it thins the blood, making arterial blockages less likely.\n\nBut most of the evidence for this is statistical. You have one group use aspirin, one that doesn't, and see who has the most heart attacks. That can show that aspirin is beneficial without us knowing exactly why it is beneficial."
]
} | [] | [] | [
[],
[],
[],
[],
[]
] |
||
9sucfi | does the brain stem ever learn anything new? | Does the brain stem learn anything over time to make it better at keeping body systems running? Or perhaps, are we born with all the software it’ll ever get - with no hope for “updates”?
FYI - not high at all. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9sucfi/eli5_does_the_brain_stem_ever_learn_anything_new/ | {
"a_id": [
"e8rrbky"
],
"score": [
7
],
"text": [
"Hmm good question. The short answer is not really. At the most basic level, the brain stem is a way for the nerves of the body (PNS) to communicate with the brain and a way to regulate autonomic functions without active thought (imagine how much of a pain in the ass it would be to have to think about breathing 24/7.) So directly, no the brain stem does not learn in that it forms new synaptic connections in response to stimuli that it can “remember” and change its function. But, the mid and forebrain can influence its behavior so long as this influence does not cause a more significant important system to fall out of “acceptable levels” like heart rate and respiration. \n\nSo the learning that takes place in these areas can influence its behavior. For example, hypothalamus of the midbrain regulates sleep cycles. This means that when the midbrain (hypothalamus) has learned it’s close to sleep, it lets the hindbrain know to trigger more parasympathetic responses (rest and digest). \n\nThis is grossly simplified and probably wrong as I’m still a student but it’s as much as I can remember from my neuro block. "
]
} | [] | [] | [
[]
] |
|
1rrmrp | why is gasoline always priced to .009? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1rrmrp/eli5_why_is_gasoline_always_priced_to_009/ | {
"a_id": [
"cdq8d11"
],
"score": [
4
],
"text": [
" > The extra \"tenths\" is a very old tradition that's never gone away. In 1935, a Reno Nevada newspaper wrote about \"selling third grade gasoline at eight and nine-tenths cents a gallon.\" \n\n > In those times, a penny had considerable value. To raise the price of gasoline from 8 to 9 cents would be more than a 12 percent hike. To compete, gas stations raised prices by tenths of a penny. Around this time, federal and state excise taxes were also introduced in increments of tenths of a cent, so it made sense to keep the decimal value.\nPerpetuated for Profit?\nThe tradition stuck. The U.S. Energy Information Administration, 'prime suppliers' of 'motor gasoline' reported sales of 372,833.5 thousand barrels sold in February 2007. These gas sales collected US$ 141 million in nine-tenths-of-a-cent increments. With gasoline prices in the US$ 2.00 to US$ 4.00 range, the 9/10 no longer serves a constructive purpose, and occasionally measures have been introduced to abolish it. From 1980 to 1984, the state of Iowa experimented with even cents, but eventually returned to the 9/10 pricing.\n\n\nSource: _URL_0_"
]
} | [] | [] | [
[
"http://wiki.answers.com/Q/Why_do_all_gas_prices_have_nine_tenths_of_a_cent"
]
] |
||
5irpdx | how can devices such as google home and amazon echo understand your voice while loud music is playing in the background? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5irpdx/eli5how_can_devices_such_as_google_home_and/ | {
"a_id": [
"dbaiprw"
],
"score": [
5
],
"text": [
"Background music adds complications to all signal processing, including for Google Home and Amazon Echo. Both of these devices have an always on functionality, meaning they are always listening. They are always listening for a distinct and very specific signal to be played (ie. your voice saying 'OK Google' or 'Alexa'). These two phrases have been broken down into their components and each component of the signal must be heard, in the correct order. So after the device processes the signal for the sound 'Oh', it expects to hear 'Kay' next. \n\nBackground noise is not able to affect the commands because even though the device recognizes there is background noise, it is only looking and waiting for specific sounds at specific frequencies in specific orders (which are the command phrases). Think of it as a coin sorting filter, no matter what you put into the coin sorting filter, it is only looking for a certain number of specific coins, and anything else will be disregarded.\n\nThis isn't to say that background noise is totally filtered out. If the background noise is too loud it can alter the command phrase and mess up the signal processing.\n\nTLDR: These devices filter out any noise signal that isn't the command phrase signal while waiting for command phrase.\n"
]
} | [] | [] | [
[]
] |
||
e4ycmw | what happens to a body when mixed with molten steel? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e4ycmw/eli5_what_happens_to_a_body_when_mixed_with/ | {
"a_id": [
"f9fzi0p",
"f9g11zg",
"f9g1ude",
"f9g44hv",
"f9i33np"
],
"score": [
9,
5,
3,
4,
2
],
"text": [
"Molten steel is at least 1370 degrees celcius. Crematoriums operate at a maximum of 980 degrees celcius.\n\nThe body is basically cremated. Burnt into ash.",
"The high temperature will burn a body to ash, and the processes used to produce and recycle steel produce a lot of waste in the form of slag and scale, which would easily mask any human cremains that are floating around",
"Water would evaporate, the carbon would be mixed in with the steel to make high carbon steel along with the other elements, depending upon the quantity of steel it might be possible to detect that a body was added to the steel by the chemical composition, but other than that it would be untraceable.",
"Well, first of, that moisture would most likely cause a violent steam explosion if thrown in to a melting cauldron at a foundry: [_URL_0_](_URL_0_)\n\nIt would be more plausible if the process is started while everything is cool, thus allowing any moisture to evaporate while the steel is melting.\n\nThis is all hypothetical, isn't it, [u/DreamSeaside](_URL_1_)? All academic?",
"I was told that molten steel has the same density as solid steel\n\nMeaning if you fell into a crucible full of molten steel, you would remain on the surface, and instantly catch fire while skating around the surface turning to steam and smoke (and dying)"
]
} | [] | [] | [
[],
[],
[],
[
"https://www.youtube.com/watch?v=nR6SWhJXc-4",
"https://www.reddit.com/user/DreamSeaside/"
],
[]
] |
|
ahp96s | why do artists and painters in movies always hold out their pen and focus on it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ahp96s/eli5_why_do_artists_and_painters_in_movies_always/ | {
"a_id": [
"eegpk1l",
"eegt3xm",
"eehdnt4"
],
"score": [
9,
3,
2
],
"text": [
"They're using the pen/brush handle/thumb as a reference for judging the size of an object, keeping it at arms length every time gives you a constant good-enough-for-art measurement.",
"people in movies or “actors” don’t usually know much about art and are just following directions from the script. If the script doesn’t say anything about what to do and just says “painter is painting” then the actor might go to a school like an academy of art to learn how to behave like an artist. But artists in art school are art students, so when actors copy and act like art students they look pretty silly, especially when an actor is trying to look like a master painter. \n\nThat said, if you’re trying to paint a realistic portrait of something, holding out your arm and squinting through one eye at your outstretched thumb or paintbrush can be pretty useful when looking at things in perspective. This is because to your eye, things look smaller the further away they are! How? Because your eye has a lens in it just like a camera. If you don’t want things to look like you see them through your eye’s lense, you don’t have to worry about any of this, just paint. or act like you don’t care.",
"for scale. and it's actually their thump that's important, typically. from the tip of your thumb nail to the knuckle is close to an inch on most people. by using a consistent reference (the height of their thumb held at the length of their arm), a reasonably skilled artist can translate distances with remarkable accuracy on the fly. "
]
} | [] | [] | [
[],
[],
[]
] |
||
fgh6lg | what causes veins in the arms and hands to bulge sometimes, in addition to a feeling of "fullness" or pressure without physical activity? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fgh6lg/eli5_what_causes_veins_in_the_arms_and_hands_to/ | {
"a_id": [
"fk62evw"
],
"score": [
2
],
"text": [
"One of the main functions of veins is to serve as a reservoir for extra blood. If you had just enough oxygenated blood in your arteries for when you are at rest, then you would have a big problem as soon as you were active. So, your veins are like balloons that can expand when needed to hold extra blood. When you work out, the veins are distended because a lot of blood is going to the tissues, and it needs to get back to the heart quickly. When you're resting, they can be distended with all the extra blood. Lots of other things affect how distended they are--such as gravity, if you're relatively dehydrated, etc."
]
} | [] | [] | [
[]
] |
Subsets and Splits