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1b90ed | Question about evolution and chromosomes. | First i am making this disclaimer. I am not making a political point, disproving evolution, or something about gays/jesus/or any of that garbage. I dont care.
Now on to my question. If evolution takes such a long time for species to change from one to another, why is it that we dont have any major species that exist whist having some members of the species having one number of chromosomes and some members having another? It seems like every species on earth has the exact same numbers of chromosomes for that species, and it doesn't deviate.
Evolution has always been taught as a gradual change over millions of years (ie giraffes necks keep getting longer is the quintessential example) but at some point for the species to change into another the number there is a biological jump that has to occur. Wouldn't there be some members of the species who have jumped already and some that haven’t? Shouldn't there be some members of a species that exist with one number of chromosomes and some with another? Also, what causes that jump, and how does it know that it should happen?
I know about the example of chimps having one more chromosome than us, but we have it fused. That example doesn't really answer my question because we are two distinct species.
Reddit, I have wondered this for a long time. I am not a biologist but have taken classes, and when I was in school not even the dean of sciences could answer this for me.
| askscience | http://www.reddit.com/r/askscience/comments/1b90ed/question_about_evolution_and_chromosomes/ | {
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"There are lots of plant species that have different numbers of chromosomes within the same 'species'. For example, in sugarcane individuals within a species can have a wide variation in chromosome number (_URL_4_). Within some species of Aster it is possible to have different chromosome counts due to polyploidy (_URL_2_). It is even possible for genomes from multiple species to come together in allopolyploid events and develop new species. We see this in wheat (_URL_0_) and cotton (_URL_1_). These polyploidy events can have huge influence on the phenotype.\n\nWhen we look deep back time in studies of plant genome evolution, we are even able to deduce ancestral polyploid events that are due to whole genome duplications (_URL_3_) that have influenced the evolution all extant flowering plants.",
"Chromosomes are humongous segments of DNA that are twisted and tangled into super-condensed structures that look like [this](_URL_7_). Humans have 46 chromosomes and 2 sex chromosomes, 23 autosomes and 1 sex chromosome per parent. Fruit flies, by contrast, have 6 chromosomes and 2 sex chromosomes - 3 autosomes and 1 sex chromosome per parent. The DNA in our chromosomes serve as a template from which we build protein. Very little of our DNA actually codes for proteins though: large portions don't code anything at all, some segments serve as structural elements, etc.. The bits that do code for proteins are called genes. The way it actually works is that the DNA is [transcribed](_URL_6_) into RNA, and the RNA is [translated](_URL_1_) into proteins.\n\nThe reason most organisms within a species have the same number of chromosomes is that even slight changes to the genome (the genome being the sum of the DNA an organism naturally makes) can have dramatic effects. There is a condition you are likely familiar with that occurs when a member of our species has an extra copy of Chromosome 21 - [Down Syndrome](_URL_4_). Our DNA is made up of something like 3 billion [base pairs](_URL_5_), and if A SINGLE base on each copy of Chromosome 11 has a specific mutation, you get [sickle-cell disease](_URL_0_). Two bases out of 3 billion.\n\nNow, back to your question. There are lots of examples of organisms within a species having different numbers of chromosomes - just not so often in big, complex organisms like humans and chimps. It takes a lot of fine tuning of genes to make us who we are, so even a small change can have profound effects. In simpler organisms, like plants, [polyploidy](_URL_3_), having more than 2 copies of a chromosome is common. Even some muscle cells in humans exhibit polyploidy (when that happens, it's called endopolyploidy). Most of our cells have 2 copies of each chromosome called homogous chromosomes (except for males, who have 2 different sex chromosomes, X and Y) - these are called diploid cells. Some cells, like most bacteria, have a single chromosome - these are called haploid cells. When a chromosome has the wrong number of chromosomes, either more or less, it is called [aneuploidy](_URL_2_). I think aneuploidy is somewhat common in fruit flies.\n\nEvolution doesn't happen like Marvel thinks it does. Changes happen extremely slowly over the course of many generations. Mutations, changes in the sequence of nucleotides in DNA, aren't always harmful, and they can even be beneficial. They can change the way genes are expressed, causing an organism to make more or less of some protein, affect the function of the protein itself, and can be completely devoid of any effect (a silent mutstion). \n\nThese changes are rare, but they happen. I mean, every time one of your cells divides, you've got 6 billion nucleotides to pair correctly. Our cells have some neat ways of proof reading and stuff, but it isn't perfect. Over time, these changes accumulate. You might not notice a change within a couple generations, but over the course of tens of thousands of years the changes become pronounced. \n\nNow think about this - let's say that a single species of bird lived over a huge area of land. Then, through some natural disaster or another, part of the original population is physically separated from the rest - an iceberg grew between them, or the land inhabited by this sub-population drifted off to sea. Both the original population and the isolated population will keep reproducing and keep accumulating these genetic mistakes, but the fact that these changes are random means that the changes won't be the same in each population. At first, the changes won't be too pronounced, but wait around a few thousand years and you'll end up with two different species.\n\nSo, yeah, that was kind of long-winded, but I like being thorough. Let me know if you have any questions and I'll do my best to answer. Don't hold back, you won't hurt my feelings. Like you, I aim not to offend, I'm simply taking the opportunity to discuss something I enjoy. Apologies if I screwed up any of my facts, I typed this on a phone so fact-checking/linking is a pain.",
"You seem to be under the common impression that evolution is improving species; that the species that exist now are better than the ones which existed historically, having passed over a \"biological jump\" as you call it. Evolution does not make species better, it just makes them more suited survive and reproduce in their environment, so if there are not drastic changes occuring rapidly in the environment then there will not be drastic changes occuring rapidly in the species which inhabit it.\n\nKeep in mind that evolution is the combination of two independent processes: 1) selection for the genetic information of individuals who are best able to survive and reproduce and 2) random changes in the genomes of those individuals. If an individual with the unique genetic change needed to acquire a new trait does not exist then the species cannot evolve in that direction.",
"This is an interesting question. \n\nOne of the most common causes of change in chromosome number is a process called polyploidy, whereby the total number of chromosomes doubles, triples or even quadruples during meiosis. In human cells, polyploidy is almost always lethal if it occurs during meiosis. In other animals, if polyploidy doesn't lethally inhibit development, it may mess with sex determination, preventing the polyploidy from spreading within a population. Polyploidy may also occur in somatic cells, and sometimes we see liver or skin cells with double the ordinary number of chromosomes, but this isn't heritable, so isn't of evolutionary significance. To emphasize: polyploidy is often lethal in animals or is difficult to pass on. There are many examples of polyploidy in fishes and invertebrates, however it is extremely uncommon in mammals, reptiles and birds. Polyploidy is selected against and thus usually not an important evolutionary force. However, in other eukaryotes, polyploidy can play an extremely important role in evolution. \n\nIn many plants for example, polyploidy is extremely common, and many plants that we use for crops have been selected for due to traits arising from polyploidy. Ferns are especially adept at not only surviving polyploidy, but also taking advantage of it. And for good reasons- doubling the amount of genetic material means that evolution has more material to play with. If you are a plant living in a hostile environment, doubling the amount of stress response genes may give you an advantage over your non-polyploid neighbour. Generally speaking, plants don't have as many negatives associated with polyploidy that animals do. \n\nFungi are another example. There has been a polyploidy event in a recent ancestor of Baker's yeast (Saccharomyces cerevisiae). This has doubled the amount of genetic material which selection can act upon, and subsequently we observe a duplication of metabolic genes; the original suite of genes encode a mitochondrial dependent pathway, while the recently duplicated set encode an alternate metabolic pathway that can produce energy when the mitochondria breaks down (which it often does in yeast). \n\nSo to sum up polyploidy- if you are 'simple' enough to regularly survive polyploidy, it will be a powerful evolutionary force. If you are too complex, as most mammals are, it will almost always be lethal, and therefore it wont play a role in evolution. Because the frequency of polyploidy is far higher in plants and fungi, we see many recent examples of polyploidy within species. Polyploidy is extremely uncommon in mammals however, and as such, the very few cases that have occurred happened millions of years ago and the polyploid population has diverged into a totally new species. If you want an anology it's like saying how come we see lots of small meteorites hit the Earth, but we never see any dino-killer asteroids? The answer is simply that six mile wide asteroids are so rare that it's unlikely we'll ever observe one during our lifetimes. That doesn't mean that they don't happen of course. \n\n\nNow, aneuploidy is another story. Aneuploidy is when you have an abnormal number of chromosomes, such as in Down's Syndrome where you have an extra copy of chr21. Similar to polyploidy it's often lethal, and seldom leads to good things in animals. However, the degree of disability resulting from aneuploidy varies greatly from lethal to minor developmental delays. Sometimes you have what is called partial aneuploidy happening, whereby a chunk of one chromosome translocates to another chromosome. Partial aneuploidy may result in a higher risk of some cancer's later in life for example, however it's less likely to result in major disabilities as full aneuploidy does. Many perfectly healthy people have partial aneuploidy's and don't know it. These people may pass on their chromosomal abnormalities to their offspring, and that trait may survive. If you lived in an isolated community of a few thousand people, after several generations, a particular partial aneuploidy may become fixed. Wait a hundred thousand years, and you may even see the gradual merger of two chromosomes. After enough time, the isolated community may evolve barriers to successful reproduction with the rest of the population, and then you will have an entirely new species. \n\nSo to summarize everything, you have varying degrees of change in chromosome number. Polyploidy involves a increasing the entire compliment of chromosomes, and is the most drastic change. As such its very often lethal, and extremely rare in mammals although plays an important role in plant and fungal evolution. Aneuploidy can increase or decrease the copy number of specific chromosome, and regularly leads to disability, though occasionally present no negative effects, because of this anueploidy may have a small role in animal evolution. Partial aneuploidy can have no negative effect, and in some circumstances may play an important role in animal evolution. \n"
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"http://www.wheatbp.net/WheatBP/Documents/DOC_Evolution.php",
"http://www.ncbi.nlm.nih.gov/pubmed/23257886",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2806165/",
"http://www.ncbi.nlm.nih.gov/pubmed/21478875",
"http://agropedia.iitk.ac.in/content/sugarcane"
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"http://en.wikipedia.org/wiki/Translation_(biology)",
"http://en.wikipedia.org/wiki/Aneuploidy",
"http://en.m.wikipedia.org/wiki/Polyploid",
"http://en.wikipedia.org/wiki/Down_syndrome",
"http://en.wikipedia.org/wiki/Base_pair",
"http://en.wikipedia.org/wiki/Transcription_(genetics)",
"http://en.wikipedia.org/wiki/Karyotype"
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5y0vk2 | how are people with dementia able to have "good days" when they remember people or events that they wouldn't normally recall? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5y0vk2/eli5_how_are_people_with_dementia_able_to_have/ | {
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"In the case of vascular dementia a lot depends upon bloodflow to the brain. The video below actually explains it like you're five.\n\n_URL_0_",
"\n\n\nYour brain is always getting information from the environment around you: what you hear people say, the color of the walls, what you see people do, the feeling of your clothes against your skin, what cards you have in your hand when playing a card game, and so on. Not all of that information is important. When you're playing a card game with friends, knowing what cards you have and hearing when your friend says it's your turn is useful, but the fact that the wall is white isn't useful information. Luckily, there is a part of your brain that decides what information is important, and filters out the extra info so you can concentrate. \n\nIn patients with dementia, that part of the brain has been damaged- it's not completely useless, but it's much weaker than it would be in a healthy person. Basically, these patients are overwhelmed with information, but they have trouble figuring out what information is important and what that information means. They may see white walls and think it means they are in their mother's house, or they may see the cards and realize they need to lay down an ace to win. \n\nThere's no way to know for sure when they will pick up on the right information, but scientists do have some ideas of what causes them to be more aware. How aware (lucid) a person is can vary based on tiredness, mood, changes in physical health, what drugs/hormones are in their body, the environment around them, how other people are acting, etc.\n\nFor example, let's say Ruby is in the middle stages of dementia and normally isn't aware of where she is. Her in-home caregiver decides to take her on a car ride one morning and accidentally begins to back up too close to the edge of a drop off, and Ruby suddenly shouts, \"If you don't pull forward we're gonna die!\" This is likely because 1) it is morning and Ruby is not yet tired, meaning the part of her brain that is damaged is not yet worn out from a busy day of trying to make sense of things, and 2) this situation is especially dangerous, meaning that other parts of Ruby's brain would recognize that this is a threat and send out hormones that improves how well the damaged part of her brain works. \n\nIn the same vein, being very tired or in a dull environment could cause a person to be less aware. \n\nMany experts believe that a lucid day (good day) happens when the \"perfect storm\" of these factors occur. ",
"My mom had dementia and most days she could remember the past clearly but her short term memory was gone. So when I'd pick her up, she'd repeatedly ask \"Where are we going?\"...but she could tell you clear as day something that happened in her thirties. Since her short-term memory was the only parts affected, I'm guessing it had to do with what parts of the brain got damaged permanently. Medication only slowed the progression but didn't stop it."
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b3z1mf | with all the processes that cell phones carry out, how are they completely silent? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b3z1mf/eli5_with_all_the_processes_that_cell_phones/ | {
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"Noise in electronics is almost exclusively from moving parts. In a computer, this has historically been fans, disc drives and hard drives. Phones typically lack all three of these sources, using passive cooling for components and solid state storage solutions.\n\nThere's still electronic elements that produce sound, but in phones, that's typically below ambient sound levels.",
"Because they don't have any moving parts such as hard drives in computers or ventilation systems which are usually responsible for the sound in a normal desktop computer or laptop."
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aql13l | why do some books have deckle (jaged) edges and others are smooth? | *jagged*
I recently took out two books from the library, roughly the same length, same genre and same publishing house. One is deckle and one is not.
I know it's a 'throwback' to printmaking, but I don't see any benefit to it. Is it just a style preference?
I'm also curious how they decide which books are and aren't. Is the choice of the author? The marketing team? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aql13l/eli5_why_do_some_books_have_deckle_jaged_edges/ | {
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"\nToday, it's a style choice.\n\nIn ancient times, books were printed in folios by folding the big sheets that came out of the press. These folios were stitched into a binding and sold that way. The edges were folded, so you couldn't read the book, but this kept them clean in shipping. \n\nWhen you got you new, expensive, book home you took out your pen knife (which you had on your desk to trim the feather you were dipping in ink to write with) and carefully slit the folios open so you could read the book. This produced the uneven edge effect.\n\nToday, there are hydraulic paper cutters that can cut thousands of sheets at a cut, but the old look is still more prestigious. So, there are special cutter machines that maintain that result.",
"Style preference these days. Older paper was handmade using a deckle. The deckle/handmade paper left a rough edge where the pulp settled. ",
"It’s a style of book that mimics elaborate and conspicuously luxurious book styles of previous centuries. Paper used to be all hand-made and very expensive as a result, as were books. As others have mentioned, books were printed on giant sheets of paper (picture the size of a newspaper page). They’d print multiple book pages on that one sheet and then fold the sheet and it would become part of the book and the owner would have to open the book by slitting open the creases between the pages. \n\nBut here are some elements no one has mentioned: books used to be sold without a binding (before the early 19th century). That is, they’d have a cheap cardboard binding that was meant to be discarded when a wealthy person purchased the book and then took it to their bookbinder to have it bound in a style to match the rest of their library. \n\nAt the time of binding, the binder would cut off the book edges to make it fit into the binding and be elegantly finished. In doing so, part of the margins would be lost. No big deal—printers would deliberately use large margins to allow for this. But once you’ve rebound the book several times, the margins would get small—it could even happen that some of the letters at the edges of lines might be lost, which ruins the reading experience. \n\nSo deckle edges meant that this book was in its original state, the margins hadn’t been cut. This is more desirable to someone buying a book because it means the book is in better condition. It’s newer rather than more used. People who collect books like deckle edges because it means the book is more pristine. There are even people referred to in the rare book world as “deckle fetishists”—collectors who insist upon books in their library having deckle edges. \n\nAlso, in the early 19th century, new paper-making techniques resulted in much cheaper paper that was also of lower quality (and didn’t have deckle edges), and books started to be sold already bound in perhaps a cheap binding. Deckle edges implied high quality handmade paper and old, fine techniques of bookbinding. \n\nAll of these distinctions have been lost, nobody knows the history of bookmaking—except printers and publishers. They continued the association of deckle edges with luxury and fine book printing and binding. And that continues up until today, even though the deckle edges may be made only to resemble the deckle edges of the past and they don’t imply hand made paper or first binding of uncut pages."
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1ns2cq | what would "plasma water" be like? | Referencing the [recent super-earth discovery](_URL_0_), I would love to understand the properties, behavior, look and feel of plasma water. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ns2cq/what_would_plasma_water_be_like/ | {
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"Plasma is a phase of matter.\n\nBasically, it's a highly charged gas. \n\nSo I imagine that \"plasma water\" is water vapour that somehow has a very high electrical charge.",
"Plasma is a 4th state of matter with the property, that it is so hot and low pressure that electrons are no longer bound to the protons. These free high-energy protons could start many chemical reactions around them or turn more atoms into plasma. This destroys many properties of the water. It becomes water vapor if it cools down enough or if the pressure increases enough.\n\nPlasma is the most common form of matter, just not on such a cold place as earth. [how to destroy a microwave and burn down the kitchen](_URL_0_)"
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16rkjk | Were "cavemen" "white"? | I know that the Homo genus is thought to have emerged in Africa, and that Homo erectus left Africa and developed in Asia and Europe while Homo sapiens were still developing in Africa. When I see depictions of Neanderthals in the media, they often seem to have more Caucasian than African features, with lighter skin and hair. Do we know anything about the skin color of early hominids, or is it all just speculation? | askscience | http://www.reddit.com/r/askscience/comments/16rkjk/were_cavemen_white/ | {
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"Neanderthals did evolve light skin. [Some of them even had the gene for red hair.]( _URL_1_) (Edit: [better link for that](_URL_0_) now I'm not on my phone.)\n\nThe earliest Homo sapiens sapiens were dark-skinned, though, and [didn't evolve white skin till much later]( _URL_2_) . We didn't inherit from the Neanderthals.\n\nSo, when Neanderthals and Cro-Magnons coexisted, the Neanderthals were white(ish) and the Cro-Magnons black(ish)."
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"http://news.bbc.co.uk/2/hi/science/nature/7062415.stm",
"http://www.newscientist.com/mobile/article/dn22308-europeans-did-not-inherit-pale-skins-from-neanderthals.html"
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9ffky1 | devs/software engineers, etc. what are you exactly looking for when searching for bugs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ffky1/eli5_devssoftware_engineers_etc_what_are_you/ | {
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"Usually, we have the code organized in such a way that it becomes as easy as possible for us to find the individual parts of the code that handles the issue we're looking for.\n\nIn the case of crashes and other similar issues the program will usually send a crash report that we can use to identify the issue.",
"Generally, you only look for bugs in the code *after* you've witnessed something break in the program while it's running.\n\nFrom there, you try to isolate the place where the code does the stuff that could make the program break. Sometimes you can do this by following the code, sometimes you need to break out tools like debuggers or just have the program print out tons of information to a logfile.\n\nA lot of programs these days are written alongside a lot of tests. If you're lucky, you can use these to find the source of the bug by seeing if any of the components don't do what you expect for certain inputs.\n\nIf you're not lucky, it's damned near impossible to track them down because the conditions for causing the bug are *super* sensitive & it won't happen once you start trying to debug the thing. When this happens, you either need blind luck or somebody who has seen the same sort of thing before to figure out where it is.",
"While programs' code can be a mess, it usually follows a minimum of structure with different logical parts being in different files, function names being somewhat related to their task, etc. \n\nYou're usually looking at it from the effects of the bug. If a number comes out wrong, you can look through the code the prints that number to see if it's a display issue where you're printing the wrong variable. If that looks fine you can then go back to the part that calculates the number and see if there's anything wrong there (simply reading the lines, maybe manually checking along with pen and paper with made up numbers to see if it checks out). Maybe you missed typed + when you meant -, or you swapped the numbers in a division, something like that. If there's nothing there you can look into the source that feeds the numbers to that calculation, see if those are coming right. \n\nFor a simple example for these last two, you could have a website that has a fancy background on the middle third of the screen. In order to display it, you have to adapt its width and location to the size of everyone's screens so that it's well proportioned and centered. When you're done writing all that, you test it and find out it's in the wrong place, with the wrong size.\n\nIt could be that you messed up the part of the code that does the math to figure out where the boundaries of the middle third are, or it could be that the numbers you thought you were getting when asking for the screen sizes came in centimeters and you were expressing the result of your calculations as pixels. \n\nThis being said, more often than not it's a one-character typo somewhere.\n\nEdit: I should mention there are things called debuggers that allow you to run your code one line at a time or stop in certain predetermined places to make all this much easier.",
"If you are unlucky, the bug was spotted by a customer and they emailed support with a screenshot of the error page and put the subject as crash. You then have to decipher what they were doing under what conditions. \n\nIf you are lucky you already have the conditions and path to reliably reproduce the bug. You can then just watch it happen and follow what areas the program goes through. \n\nDoing this usually tells you exactly what area or even what line of code crashes and why. You can then come up with a nice way to fix it. Then you can go around and test lots of other ways to get to the same are and see of it still crashes and the bug is fixed correctly.",
"A software bug is a discrepancy between what you think the code should do and what it actually does. For example, consider this simple function: \n\n\nint addTwo( int input ){ \n return( input + input ); \n} \n\n\nThis function takes in a number (int) as input, adds two to that number, and then returns the result. We might test this function: \n\n\nint result = addTwo( 2 ); // Add two to two, store the answer in 'result'. \nprint( result ); // Prints out the result, which should be, and is, \"4\". \n\n\nSo this function works, right? WRONG. Look again. It's not adding two. it doubles the input! This is what the function should be: \n\n\nint addTwo( int input ){ \n return( input + 2 ); \n} \n\n\nThis is a simplified example, of course. But as you write more complex code with many function and files and systems and so on, there's plenty of space to make a mistake that testing won't catch... until something isn't working right. And at that point, you have to locate the discrepancy.",
"To try to give a higher level explanation:\n\nThe design document for your program should list all the things the program is “supposed” to do. For example, “When user presses button, product is added to cart.”\n\nIf you’re a good developer, you write lots of tests to simulate each thing the program is supposed to do. So you might have a test that simulates the button being clicked, and checks if a product was added to the cart. If some of these tests fail, you have a bug. The program didn’t do what it was supposed to.\n\nIf you’re a bad developer (and most people are somewhere in between), you don’t discover the bugs until a user actually does the thing and it doesn’t work.\n\nYou then look for the parts of the program related to the thing that didn’t work, to figure out why. Clicking the button didn’t add the product? Let’s look at the button code. Instead of testing the whole process (button adding product), we can break it down into steps (button knows it was pressed, button sends signal, product page receives signal, product page retrieves shopping cart, etc) and test each individual step to find where the bug is."
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4yr30w | Japan's annexation of Korea and its aftereffects? | As a tennage Korean living in America, I've been curious about this subject for a while now. So exactly what did Japan do to Korea during its annexation, and what are they still doing wrong? I've heard that Japan doesn't educate its students of the wrongs they did, and that they haven't really apologized to Korea. But on WIkipedia, there's a list of apologies Japan made. Are they not considered real apologies? Also, how do younger Koreans (teens-20s) feel about Japan? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4yr30w/japans_annexation_of_korea_and_its_aftereffects/ | {
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" > what did Japan do to Korea during its annexation\n\nThey took over all of Korea and made it a part of the Japanese empire. During their time in Korea, they:\n\n* built an information network consisting of police and local informants to keep tabs on everyone (where do you think North Korea got the idea from?)\n* during the first part of the annexation, they dealt with Koreans very directly and harshly. Around the 1920's, they began to take a more hands off approach and used their information and control to direct Korean independence energy where they wanted it to go, usually nowhere.\n* they built shinto shrines all over the country\n* they required all Koreans who wanted to work in the government or go to school to adopt Japanese names. Near the end (1940s), they required ALL Koreans to adopt Japanese names.\n* during the war, they lured young Korean women into prostitution, using the prospect of good factory jobs as bait.\n\nLong story short, they did a lot of really shitty things.\n\n > But on WIkipedia, there's a list of apologies Japan made. Are they not considered real apologies?\n\nNo, they aren't.\n\nThere are a few issues. First, the Japanese apologies frequently use language that is indirect. They don't simply say \"we're sorry for what we did,\" but they \"express regret for what happened.\" Second, and much more importantly, there are three audiences: domestic, international, and Korean/Chinese (China is just as much a victim as Korea is). While international audiences (Europeans, Americans, YOU) see the apologies that the Japanese have made and think, \"what's the problem, they've apologized, move on!,\" the domestic (Japanese) audience sees \"we've lost face, we've shown we are weak\" and then the right-wing politicians get antsy and issue denials or retractions or clarifications. So what the third audience (Koreans) sees is Japan apologizes on the first day with a lukewarm apology and then the prime minister takes his colleagues to the Yasakuni Shrine and then issues a statement \"clarifying\" the apology.\n\nReally, without breaking the 20 year rule, it's pretty tough to discuss here because the first major apologies came out during the mid 90's, and then a lot of the trouble has come from Shinzo Abe and his party, who are in power now. I'd suggest reading the [Hankyoreh](_URL_0_) (left wing paper) and the [Joongang Ilbo](_URL_1_) (center-right wing paper) and search for articles on Japanese apologies. There was a big one in December of 2015 that was supposed to be a huge breakthrough and then within a few days it became a huge controversy.\n\n > how do younger Koreans (teens-20s) feel about Japan?\n\nAgain, 20 year rule and anecdote rule, but if you look around for surveys, you'll find some information."
]
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"http://english.hani.co.kr/",
"http://koreajoongangdaily.joins.com"
]
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|
2mgfnu | Are there any historical figures that we know what they sounded like? | I'm of course not talking in terms of people who have been recorded. But are there any reports of the style of speech of say... king Henry VIII, Alexander the great, confucius, or Constantine? Or any historical figure.
What was their voice like? Deep, stuttering, high, always breaking, lisp? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2mgfnu/are_there_any_historical_figures_that_we_know/ | {
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"One story that comes to mind refers to the Rhode Island Calvinist minister Samuel Hopkins. William Ellery Channing, who later became a key figure in the Unitarian church, recalled this about Hopkins' preaching:\n\n > I understand, that the interest, expressed by me in the character of Dr. Hopkins, has surprised some of my townsmen in Newport, who knew him only by report, or who saw him in their youth. I do not wonder at this. He lived almost wholly in his study, and like very retired men, was the object of little sympathy. His appearance was that of a man who had nothing to do with the world. I can well recollect the impression which he made on me when a boy, as he rode on horseback in a plaid gown fastened by a girdle round his waist, and with a study cap on his head instead of his wig. His delivery in the pulpit was the worst I ever met with. Such tones never came from any human voice within my hearing. He was the very ideal of bad delivery. Then I must say, the matter was often as uninviting as the manner.\n\nThat recollection comes from [this source](_URL_0_), which has a great story about ruffles on the follow page.\n\nAlthough I don't recall the source, I've been led to understand that despite Hopkins' position of influence within New England Calvinist theology at the time (he lived from 1721-1803), even his own congregation could barely stand the sound of his voice."
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"http://books.google.fm/books?id=54s1AQAAMAAJ&pg=PA41&lpg=PA41&dq=%22his+delivery+in+the+pulpit%22+%22such+tones%22&source=bl&ots=-jyWEQbhq-&sig=3_ZlBVBtGT_ayYo_fTTmcxXcSBA&hl=en&sa=X&ei=AIVoVOndKMfLmAWD2oCoBg&redir_esc=y#v=onepage&q=%22his%20delivery%20in%20the%20pulpit%22%20%22such%20tones%22&f=false"
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219ion | why do bulletproof vests have an expiration date? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/219ion/eli5_why_do_bulletproof_vests_have_an_expiration/ | {
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"Temperature, humidity, and use all affect the ability of the kevlar to do it's job, so manufacturers only warranty them out to a certain period of time.\n\nIf you kept your kevlar in a cool, dry, and dark place for 100 years, it would still work just fine -- problem is, if it's not on your body, it's not much use.",
"Kevlar ( and virtually all materials ) degrade over time. You can read about the degradation of Kevlar in [dupot's technical guide about kevlar](_URL_0_)"
]
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[],
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"http://www2.dupont.com/Kevlar/en_US/assets/downloads/KEVLAR_Technical_Guide.pdf"
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||
48zvuo | how did people back in the day not realize that cigarettes were very unhealthy? | I feel like it's obvious the negative effects it has on your body and how you feel if you smoke. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/48zvuo/eli5_how_did_people_back_in_the_day_not_realize/ | {
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"People as a whole are very good at self-denial. Along with tobacco companies trying to push the message that they're healthy as hard as possible, people just bought into it. (those companies did their best to push it into popular culture as much as possible). \n\nI mean, look at alcohol. People know its bad for them, the evidence for it is insane. yet, people still drink. Or soda for example, i'm sure you drink soda from time to time, don't you know it's bad for you? If so, why do you still drink it? and boom, theres the answer to your question ",
"There was a time when brands were endorsed by the medical profession. \n\"More doctors smoke camels...\"\n\n_URL_0_",
"Basically nobody really bothered to run any tests to show there was a connection with certain health problems and smoking. Cigarette companies denied that smoking was harmful for a very long time. It was only really discovered that it caused lung cancer when there was a spike in the amount of people who had lung cancer around the 1940-50s. Even then cigarette companies continued to deny it. A lot of studies eventually showed clear evidence that it was actually harmful around the 60s. ",
"They did- the nickname \"coffin nails\" was used for decades before the Surgeon General's report.",
"Consider that today we are having a debate about \"big is beautiful\". \"Love your body\" is the new mantra, yet the average american is at least 30 lbs. overweight. 1 in 4 medicare dollars is spent treating type-2 diabetes. Are we really so learned today?",
"Oh, don't make the mistake of thinking people didn't know. They did, they just kidded themselves and ignored the obvious. Besides, there were other things to worry about. \n\nIn 1604 King James of Scotland said...\n\n\n\n > Have you not reason then to bee ashamed, and to forbeare this filthie noveltie, so basely grounded, so foolishly received and so grossely mistaken in the right use thereof? In your abuse thereof sinning against God, harming your selves both in persons and goods, and raking also thereby the markes and notes of vanitie upon you: by the custome thereof making your selves to be wondered at by all forraine civil Nations, and by all strangers that come among you, to be scorned and contemned. A custome lothsome to the eye, hatefull to the Nose, harmefull to the braine, dangerous to the Lungs, and in the blacke stinking fume thereof, neerest resembling the horrible Stigian smoke of the pit that is bottomelesse.\n\n",
"Probably the same way people today think Vaping is not dangerous for them. In 20 years, there will be a post like\n\nELI5: How did people back in the day not realize that vaping was very unhealthy? I mean, its literally water vapor in your lungs",
"If smoking killed people in six months, there wouldn't have been any question about it. Instead it can take decades for lung cancer to show up, and a 50-year-old with cancer isn't seen as a gross miscarriage of the natural order of the universe. It's about the age when you expect to have a few friends start dying off and it's not as sensational as a 25-year-old with cancer.",
"Why would it be obvious. People who smoked had pleasurable, positive feelings from smoking, so they associated it with good health. ",
"1) smoking does not kill right away, even if it smells awful. You can pretend it's not killing you if you want the nicotine effect.\n\n2) People drink. Why? IMO that one's a mystery. And even alcoholism-level drinking doesn't kill you right away. Alcohol tastes awful, but people still drink enough to harm themselves. It's the buzz, and the convenience/escapism of being drunk I guess?\n\n3) Tobacco smoking preceded most of health science, so it was an established \"thing\" and people may not have thought they had any reason to question it.\n\n4) Scientists eventually did study whether smoking caused health problems. It started to become obvious to these scientists that it did cause health problems. Tobacco companies put massive time, money and effort ensuring word would get out slowly if at all, and tried to keep findings from gaining any credibility in the public eye.\n\n5) Tobacco companies actively advertised their product as healthy, and convinced many people that it was supposed to be healthy. Saying \"it's not healthy, it's dangerous\" can start to make you look like a crazy person if everyone else wholeheartedly trusts that it's a good thing, and only you are questioning it.\n\ntl;dr: substances gonna get abused, + propaganda and lies."
]
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ac60z1 | How likely was it that "heroes" of the past killed as many as books and TV make it seem in battle? | In a lot of historical fiction in TV and Literature, you'll often see a protagonist or hero kill scores of enemies on the battlefield. How accurate was it that in battle these people were so superior to their enemies that they could easily kill a multitude of them?
Or was it more the case that each warrior fighting would likely kill one or two before being killed themselves and winning was more reliant on numbers in that sense?
Would a trained warrior fighting a bunch of farmers for example, out on an open battlefield, really be able to kill off that many of them? What about against soldiers?
The reason I ask is I've been catching up on Vikings and some of the battle stuff annoyed me. Now, I know it's not at all historically accurate but I did realise its a bit of a trope to have warrior heroes who seem to massively be more effective at murdering their opponents than their fellow soldiers or enemies, and it got me thinking whether this was in anyway grounded in reality or just a storytelling device
| AskHistorians | https://www.reddit.com/r/AskHistorians/comments/ac60z1/how_likely_was_it_that_heroes_of_the_past_killed/ | {
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"Ehh... sometimes?\n\nFirst of all the thing to realize is that the idea of the warrior as a hero is... controversial in history.\n\nEven the best and most effective of them are more like a political force. The warrior as a hero is much more common in myth and legend than in actual history.\n\nNext, the thing to look at is specifically in the early medieval period, when a lot of Vikings purports to take place, how many folks actually died in battle as opposed to being killed by other things or dying later of wounds? The answer was, surprisingly, quite a few. \n\nBut when and why? You might ask. Or you would if you were me and were ridiculously obsessed with medieval warfare when you probably shouldn't be.\n\nThe answer is an odd one and depends heavily on the composition of forces in the battle. But let's take a look at some of the actions that would be depicted in Vikings.\n\nSomething like the Battle of Edington. The thing is, about the only thing we know about that battle is who won and what resulted. The Vikings lost. And the resulting events changed quite a bit about how things were done in what became known as the Danelaw after that.\n\nSo let's look at another battle that is at least semi-representative of the period. Though it is an anomaly in many ways, it has the distinct advantage of being one that we DO have good sources for:\n\nThe Battle of Stanford Bridge. The Vikings, or more precisely the Kingdom of Norway under the command of Harald Hardrada brought about 9000 troops, all heavy infantry as far as we know, to the battle.\n\nThe English king Harold Godwinson brought about 12500 troops, of which about 2000 were cavalry.\n\nThe English won, but lost about 5000 troops. The Vikings lost about 6000. From what reports and sources we have, most of these were lost to the cavalry charge when the shield wall broke.\n\nThis is consistent with other battles we know of from this period.\n\nMost deaths tend to be during the retreat. People fleeing are vulnerable and cavalry can run them down and slaughter them without much hindrance.\n\nNow, how unrealistic is it that a man on foot can slaughter many others without dying?\n\nWell, pretty unrealistic for most. But not to the point of impossibility, at least not until the more ridiculous scenes. For instance, at the Battle of Nahāvand a force of about 30000 Arabs defeated a force of about 100000 Persians that were entrenched in a superior position, inflicting heavy losses on them.\n\nSo, yes it happens, but is almost always exaggerated for narrative effect during TV shows. Usually what happens when one man tries to fight multiples is, he dies very quickly."
]
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] |
|
scdyv | Mercury is an ingredient in some skin whiteners. How toxic is exposure to 30 000 ppm of Mercury? | [link](_URL_0_) | askscience | http://www.reddit.com/r/askscience/comments/scdyv/mercury_is_an_ingredient_in_some_skin_whiteners/ | {
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"[Here](_URL_0_) is an MSDS I found. This will give you government regulations on skin and vapor exposure. I would assume that 30,000 ppm mercury is extremely dangerous based on the IDLH number. IDLH stands for \"Immediately Dangerous to Life and Health\" and represents the maximum suggested exposure for a \"one-time\" exposure.\n\nOther values include TWA which stands for \"Time-Weighted Average\" and that specifies a suggested amount for continuous exposure for workers in mercury environments. (I believe the TWA is for 8-hour work days and 1,000 work-hours per year.)",
"I assume there are different values because ones I'm aware of are for presence in marine sediments. In water, animals will be ingesting it, but in this case people are rubbing in on their face.\n\nBut NOAA guidelines show an ERM (effects range median) of 0.71 ppm, and ERL (effects range low) of 0.15 ppm. Those are ranges where effects are known to occur.\n\nThat said, 30,000 ppm is ridiculously high. I wouldn't go anywhere near those."
]
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45md5c | Mozart was a man during the time of the American Revolution. Beethoven was a boy. Did they or any of the other European Classical or early Romantic composers comment on the birth of the USA? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/45md5c/mozart_was_a_man_during_the_time_of_the_american/ | {
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"I can answer for America being \"commented on\" in music but not in people's personal lives: \n\nAccording to Pierpaolo Polzonetti, there are 13 known Italian operas with references to Revolutionary America, either being set in America or featuring American characters, however they are all pretty /r/elitistclassical composers, no one you're likely to be very impressed by! Some of the more interesting examples: \n\n[Niccolo Piccinni](_URL_0_) wrote two operas about America in 1768 and '69, he was successful in his time (enough to merit an Italian Wikipedia article at least) but not popular now. \n\n[The Witty Quaker Girl]( _URL_2_ which is a comedy, featuring (you guessed it) a Witty Quaker Girl coming back from America to Italy, breaking her promised marriage to an old count, and proposing to his sexy vineyard worker while holding him at gunpoint. Guglielmi was also successful in his time. \n\nThe list of 13 identified operas is in [Italian Opera in the Age of the American Revolution](_URL_1_), the author also argues for Mozart/Da Ponte's setting of *Le Nozze di Figaro*, while not being set in America, to be inspired by the themes and spirit of the American Revolution, which may be of more interest to you! "
]
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"https://it.m.wikipedia.org/wiki/Niccolò_Piccinni",
"https://books.google.com/books/about/Italian_Opera_in_the_Age_of_the_American.html?id=iRmf8zJGAjUC",
"http://imslp.org/wiki/La_Quakera_spiritosa_(Guglielmi,_Pietro_Alessandro%29)"
]
] |
||
1o4z68 | When have nation-state appeared? | You can often read that medieval peasants didn't care much about their nationality and seen themselves as people of specific village/city rather than country, while aristocracy would communicate with anyone, and religion mattered much more than nationality. Was medieval society really so global? How did it changed? Kind of hard to imagine this transformation. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1o4z68/when_have_nationstate_appeared/ | {
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"These are very good questions.\n\nMany experts correlate the birth of the nation state as we know it with the Treaties of Westphalia, signed in 1648, which ended a variety of wars in Europe, most importantly the Thirty Years War in the Holy Roman Empire, and the Eighty Years War between Spain and the Netherlands (which led to Spain accepting the Netherlands as an independent nation, and a republic). The Treaties of Westphalia formulated the idea of sovereignty within a territory (think of it as a way of formalising the status of monopoly of a state over a geographic area), which essentially forbade external actors from interfering in domestic matters inside a nation state.\n\nI'm painting broad strokes here, but the upshot of this framework - combined with the idea that people should rule themselves rather than be ruled by a monarch whose claim was that God had granted him sovereignty - is what then led to the right of self-determination which forms the basis of legitimacy of the modern nation state.\n\nPrior to this era, few people would have considered themselves to \"be\" Spanish, or \"be\" Italian, even though those words existed (largely to identify geographical regions). People equated their attachment to land more in the way that Germans interpret the word \"heimat\" (home, but in a bigger sense): being from a village, a region. \n\nAs I mentioned \"being\" Italian, this sense of equating the state with the geographical region, and personal attachment to the nation state came much later. Even when Italy was unified, most people still didn't feel they were \"from Italy\". Famously, the Italian author Massimo d'Azeglio declared after the unification of Italy that \"we have made Italy, now we must make Italians\". \n\nIn Italy, even in the 70s when I grew up, president Leone and prime minister Aldo Moro were still concerned about this issue: many Italians simply did not attach themselves to the concept of Italy.\n\nThis is the key reason why, in 1974, Aldo Moro created the Ministry for Culture in Italy (my father worked on this for many years), the idea being that the State should be an energy that pushes Italians' awareness of their culture as something that manifests itself in every aspect of their life, which would then create a legitimate role for the state to play in people's cultural interaction with Italian society. \n\nIn modern terms, you could see this role as that of a brand. Brands are not just pretty logos, they are the aggregate image that people form for themselves around a company or product, a way to humanise their interaction with a company and interact with it the way they do with a person. I gave a pretty long lecture about this last year at McCann Erickson, which you can read here: \n\n_URL_0_\n\n\n\n\n\n"
]
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|
7w8qas | if they have single stream recycling. why can they not do that with all garbage? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7w8qas/eli5_if_they_have_single_stream_recycling_why_can/ | {
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"In a sense, they can. There are plenty of areas which don't collect recyclables separately, but try to recover them from the garbage before it goes to the landfill. The yield from this is much lower than single stream, though--just like single stream is not as efficient as separated collection. On the other hand, the operating costs are lower, as well. The decision on what system to use depends on local operators, people's willingness to separate, the cost of separate collection, etc."
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9ghb5r | what happens if the market crashes on 2020? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ghb5r/eli5_what_happens_if_the_market_crashes_on_2020/ | {
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"Boy, if anyone had a way to accurately tell you that, then that person would probably not be on Reddit.",
"Having gone through it myself, I can tell you that a lack of preparation and liquidity made it a million times harder. Right now I am prepping for it by hoarding as much cash as possible. Where most people would say, pay off your debt right away, I take a little slower approach and set aside 2 times as much cash as I put into debt reduction and living expenses. \n\nBut it really depends what industry you are in and your talents there. Look out for things that might come up that could derail your industry: commodity prices, over leveraging, local market industry saturation (cities dependent on any one type of business - like oil). It’s worth asking the question to someone your work with that might have survived through the last downturn. Ask them what happened during all of it. \n\nHoard cash, don’t over extend, and then once it crashes again, find some solid investments and go all in and ride that bitch to early retirement. ",
"Bosses become ruthless....Not playing ball, not a longtime employee, or are redundant? Cya! No raises and possibly a couple pay cuts. Expect to work longer for less pay. \n\n\nMeanwhile retirement savings collapse so all the older people put it off. Which further puts pressure for everyone else to perform more and do more. \n\n\nJust sucks all around. "
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4rl98v | If all the cars on the road were self driving would there be less accidents? | askscience | https://www.reddit.com/r/askscience/comments/4rl98v/if_all_the_cars_on_the_road_were_self_driving/ | {
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"Almost certainly yes. Of course there are a lot of details that need to be considered, but in all likely scenarios the answer is yes. The biggest thing that would cause this is if the cars communicated with each other and with the infrastructure, if they did this then the computers running the networks would know where all the cars were, where they were going, and everything else about the roads. This would almost entirely eliminate accidents due to mistakes. Of course if there is a giant snowstorm and a car loses control that could be an issue, but I suspect that in such a connected scenario it would be better than having humans. There are a multitude of different scenarios for how this technology will play out, so it's hard to predict the exact details. I'll just say though, that this is one of the primary concerns of the people and organizations implementing this technology and so you should expect it to eventually work very well. ",
"You need to differentiate between 'accidents' and 'collisions'.\n\nAccidents are unforeseen and/or unavoidable. Those will stay almost the same. The exceptions are mechanical failures and medical emergencies - those are very rare, and will be reduced.\n\nCollisions will be reduced to almost zero."
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7sfjil | if muscles are built by repairing damaged muscle tissue, could we surgically, or in some way other than a workout damage them and let them recover , leaving us with more muscle mass? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7sfjil/eli5_if_muscles_are_built_by_repairing_damaged/ | {
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"Well, when you involve nanobots and hypothetical technology, all bets are off.\n\n*Currently*, the most cost-effective way to build muscle mass is to hit the gym. Muscles get micro-tears by fully engaging, and they won't fully engage unless there's resistance to work against, like lifting something heavy off the floor. \n\nYou can get muscles to tense up by stimulating them with an electrode, but 1) that's a lot of time, machinery and probably doctor supervision for safety 2) not every muscle is easily reached, other muscles or organs can be in the way.\n\n"
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c3yfsq | Holocaust reveal? | I have searched fir the moment when the world, us in particular as Im American, found out about the holocaust. I would imagine it wouls be such a defining moment, but i cant find anything about it. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/c3yfsq/holocaust_reveal/ | {
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"u/commiespaceinvader answered a similar question [here](_URL_0_)."
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5wrsrk | why does aluminum foil spark in the microwave, but doesn't when its used as the container for, say a chicken pot pie? | When I put aluminum foil in the microwave by itself it sparks and makes pretty colors.
On the other hand, when I put a potpie in the microwave and its container is made of aluminum foil it never sparks.
Why does this occur?
Edit2: follow up question- Why does a CD in the microwave react the way it does? Here is a source to a [video](_URL_0_)
Edit: Decided to flair it as physics, could be chemistry.
maybe someone could shed light on where it fits best.
Thank you.
| explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5wrsrk/eli5_why_does_aluminum_foil_spark_in_the/ | {
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"text": [
"Rounded vs. pointy sections. Crumpled foil has pointy sections. Same reason lightning rods are sharp. \n\nYou can leave a spoon in the microwave in your tea or food, and probably a fork IF the tines are submerged. Don't try to to use a fork in your food with the tines exposed. ",
"Basically, microwaves work by generating low-frequency radio waves that excite the molecules in food. This excitation generates heat, and the conductive properties of the food or liquid carries that heat to the center of the item. \n\nMetal will reflect these radio/microwaves. This is why a microwave is basically a big, secure, metal box--so you don't cook everything in the room around you. If you put a thick piece of metal in the microwave (say, like a pot pie pan) then the microwaves are simply reflected back and forth between the pan and the walls of the microwave.\n\nHowever, a thin sheet of metal like a strip of aluminum foil can't withstand the energy provided by the microwaves and will rapidly heat up and ignite. The electromagnetic field in the microwave will cause a current to run through the foil, and if the foil is crinkled into sharp edges, the current will discharge as bright sparks."
]
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"https://youtu.be/0JkCIfLE_-M"
] | [
[],
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|
29vcgc | In the 1974 World Cup hosted by West Germany were East Germans and Soviets isolated from the event? | I'm curious to see how the geopolitical environment of West Berlin affected the the demographics of people who came to watch the World Cup in 1974. Was there any paranoia held by travelers? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/29vcgc/in_the_1974_world_cup_hosted_by_west_germany_were/ | {
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"Lets have a look at this German source: _URL_1_\n\n- WC '74 lead to one of Stasi's biggest operations. Hundreds of agents were send to West Germany to prevent East German tourists from fleeing.\n\n- 5188 GDR citizens visited the WC '74.\n\n- prior to the world cup the Stasi investigated each one of them. It didn't matter whether it was one of the soccer players, manager or just a fan.\n\n- In February 1974 there were about 1700 initial applications from citizens who wanted to visit the world cup. They were all denied and an investigation was started against every single one of them. This meant you could only visit the world cup if the leaders wanted you to.\n\nBonus: Here's a photo of the match West Germany vs East Germany (they were randomly placed in the same group) which East Germany won 1-0: _URL_0_\n\nThe matches of East Germany were shown on television in Eastern Germany. The world cup was not shown in the Soviet Union and China.\n\nedit: Some more info regarding number of visiters in the stadiums:\n\nThe matches of Germany and the Netherlands were those with the highest number of tickets sold. Also Italian and Yugoslav matches had many visitors because there were many immigrant worker from those countries in Germany.\n\nMany West Germans expected their team to be 1^st in their group so they bought tickets for matches that they expected the German team to play in after the group stage. However Eastern Germany managed to be 1^st in this group so after that their matches had many visitors because West German fans had already bought the tickets. However, many people did not visit the match of Eastern Germany vs Argentina because it was meaningless for both teams. 53k tickets were sold but only 20k people showed up. \n\nThe number of visitors was also affected by France and England both not participating in 1974 and of course Bulgaria, Eastern Germany and Poland did not allow many people to visit the WC. Another factor was the time of the year. Stadiums did not have roofs and it rained a lot. So particularly boring matches where not visited when it rained.\n\nsource: _URL_2_"
]
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"http://www1.wdr.de/fernsehen/information/sport_inside/sendungen/ddr-wm102_v-ARDFotogalerie.jpg",
"http://www.motorvision.de/news/fussball-national-wm-1974-groessten-stasi-operationen-ausserhalb-ddr-167028.html",
"https://de.wikipedia.org/wiki/Fu%C3%9Fball-Weltmeisterschaft_1974"
]
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|
p5qtd | Is there any other material that gets its color from Rayleigh scattering, like the sky does? | So I know that the sky is blue because air scatters shorter wavelengths away more than it does longer wavelengths, which also explains why the colors left over that we see at sunset/sunrise are long wavelengths (red etc). But if someone asks me why it isn't just that air itself is very slightly blue in the way that water is very slightly blue, is there an example of another material colored by this kind of scattering that I can use to illustrate the difference? | askscience | http://www.reddit.com/r/askscience/comments/p5qtd/is_there_any_other_material_that_gets_its_color/ | {
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"Yes. Phase separated glass does this same thing. A glass of composition 0.2 Li2O - 0.8 SiO2 will undergo phase separation if cooled slowly. It forms a droplet phase dispersed in a matrix phase. If you hold the glass in your hand, it looks blue/white, but if you hold it up to the light, it has a yellow/orange look. \n\nI had a few pictures of such a glass on my phone, so just uploaded them side by side: _URL_0_\nThe one on the left is the view with just transmitted light. The image on the right is with the camera's flash, so it appears blue.",
"Sorry to cite Wikipedia, but I'm a layman... just remember finding this fascinating.\n\n[Blue eye color caused by Rayleigh scattering](_URL_0_)"
]
} | [] | [] | [
[
"http://imgur.com/raqt9"
],
[
"http://en.wikipedia.org/wiki/Eye_color#Blue"
]
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|
9chjgl | when frying chicken why is it important to dip it in flour before the batter and breading? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9chjgl/eli5_when_frying_chicken_why_is_it_important_to/ | {
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"Batter and breading don’t stick very well to raw chicken. Flour sticks to both so you use it as a in-between layer.",
"I read once that protein sticks to gluten. So chicken (protein), then flour(gluten), then egg(protein). Another flour and egg cycle after that give you a thicker coating. Not sure if thats scientific but it seems to work well"
]
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[],
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||
zatbd | How did the romans morally justify their wars of conquest? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/zatbd/how_did_the_romans_morally_justify_their_wars_of/ | {
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"Broadly speaking, they didn't need to. Your question is assumes that war is morally objectionable. But the \"scourge of war\" as it exists today is a very modern concept, and can traces its origins to the aftermath of the WWI. (And to a lesser degree the Thirty Years War)\n\nThe Roman people considered themselves the \"sons of Mars\" (the war god), and warfare was morally praiseworthy act. \n\nI think a nice illustration of the changing attitudes towards war can be seen in the response towards a line in Horace's (a Roman contemporary) *Odes*: [\"dulce et decorum est pro patria mori\"] (_URL_1_), *its a sweet and noble thing to die for one's country*.\n\nA thousand odd years later, Wilfred Owen, a WWI veteran uses [Dulce et decorum est] (_URL_0_) as the title for his gas attack poem. His final stanza: \"The old lie: *dulce et deocrum est pro patria mori*.",
"Morals are fairly fluid in terms of history, Slavery, Genocide, War never really had moral qualms to them in different parts of history. Romans believed they were descended from the God of War, Mars himself so war was a natural state.",
"The Romans didnt need to morally justify their wars. They didnt have any qualms with conquering a people, and if it was required, butchering their civilization in order to do it. As other posters have pointed out our modern uneasiness with war is just that, modern.\n\nWhat the Romans *would* do is declare a just war. Livy give a description of the process for declaring a war. If the ceremony was ever conducted improperly then the gods wrath would put the whole war in jeopardy. Further, Rome tried to be victims or use revenge to justify their wars (until the Roman Revolution, when things changed). \n\nTake the classic example of the Second Punic War. After the First Punic War, the Romans and Carthaginians skirmished over Spain until finally deciding that the border between the two countries was the Ebro river. Now Rome wanted all of Spain, it had rich gold and silver mines along with coming at the expense of the great Carthaginian rival. Now the Romans had agreed to end its influence with any city south of the Ebro river, yet one city, Saguntum, declared that they were still friends and allies of Rome. Despite its location, Rome accepted the city's friendship. To make a longer story short, Hannibal the Carthaginian went to force the city to accept his dominance and besieged the city. The Romans came to the aid (spiritually of course, the city fell after a long hard siege) and had its pretext for war. Rome was clearly the aggressor, it had illegally maintained an alliance with a city it had ceded, but the gods got their excuse for war. ",
"What's yours is mine, what's mine is also mine. \n\nThat said, while the Romans did not seem to need much moral justification for their conquests, they often went to quite extreme lengths to come up with legal justifications for their wars, the third punic war being my favorite, and the most absurd, example of this.",
"It's funny. Even the Athenians, who had DIRECT democracy, time and time again would vote themselves off to war at the drop of a hat.",
"Not actually historian here, but what I have read that they often played the following trick: suppose there are two other small people somewhere who often engage in small-scale warfare (slave raids etc.). This was very common. Make an alliance with one. Wait until the other attacks/raids the ally, have perfect excuse to conquer them. \n\nIt is all about helping an ally and stopping an aggressor, a perfectly defensible thing. Except that the aggressor only committed small raids (and similar small raids were committed against them) while what they got is final, total conquest, so obviously the punishment did not match the crime.\n\nAt any rate, they tended to have allies everywhere, at Caesars conquest of Gaul some Gauls were allied etc. and this tends to give excellent excuses."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Dulce_Et_Decorum_Est",
"http://en.wikipedia.org/wiki/Dulce_et_decorum_est_pro_patria_mori"
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[],
[],
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||
9a6lrc | Is it true that the T-34 was built in the United States during WWII as a help to the Soviets, so they could beat the Germans? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9a6lrc/is_it_true_that_the_t34_was_built_in_the_united/ | {
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"The answer to this is \"No\". The T-34 was produced at the following Soviet factories in the following numbers, although as with any Soviet statistics, these are more estimates that absolutes, and there are higher numbers given which likely also include full-overhauls rather than just new production.\n\n\n\nFactory | Production\n---|---\nUZTM | 719\nCzKZ | 5,094\nZawod No. 174 | 5,867\nSTZ | 3,770 \nZawod No.112 | 12,604 \nChTZ No. 183 | 1,675\nUTZ No. 183 | 28,952\nTotal | 58,681\n\nThe closest thing that can be said about American \"production\" is that the T-34 was based off of the Christie suspension design, an American design which they had initially copied wholesale with the BT-2, a copy of the Christie. To be sure, America (and the UK) *was* building tanks for the USSR, but rather than going through the process of retooling for production of Soviet designs (assuming the Soviets would even have agreed to it), they were sending their own designs.\n\nType | Delivered\n---|---\nMatilda II | 918\nValentine | 3,332\nChurchill | 263\nCromwell | 6\nTetrarch | 20\nM3 Stuart | 1,232\nM5A1 Stuart | 5\nM24 Chafee | 2\nM3 Lee | 976\nM4A2 Sherman | 3,664\nM26 Pershing | 1\nM10 3in GMC | 52\nM18 76mm GMC | 5\nT48 57mm GMC | 650\nM31 ARV | 127\nTotal | 11,253\n\n*T-34: Mythical Weapon* by Robert Michulec\n\n*Soviet Lend-Lease Tanks of World War II* by Steven J. Zaloga"
]
} | [] | [] | [
[]
] |
||
1a97me | How many species out populate humans? | Obviously plenty of insects and I'm guessing some fish, but which larger animals. | askscience | http://www.reddit.com/r/askscience/comments/1a97me/how_many_species_out_populate_humans/ | {
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"Not strictly scientific, but a pretty basic answer to your question from NPR: [link](_URL_0_)",
"What's your definition of \"larger?\" Lizards? Small rodents? Or do you mean an animal with similar or larger dimensions than a human?"
]
} | [] | [] | [
[
"http://www.npr.org/blogs/thetwo-way/2011/11/03/141946751/along-with-humans-who-else-is-in-the-7-billion-club"
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[]
] |
|
mfyjo | what would happen if a person drank 100 cups of coffee in one day, ala futurama? | If you haven't seen the episode, everyone in the country gets a $300 tax rebate. Fry decides to spend his on 100 cups of coffee. By day's end, he basically reaches a sort of enlightenment, everything around him slows down (to him), while he's actually moving faster than the speed of light.
I know that ending wouldn't really happen, but what would? Stroke? Heart attack? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/mfyjo/what_would_happen_if_a_person_drank_100_cups_of/ | {
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"I remember an article with a reader asking if it was possible to ingest a lethal dose of caffeine, and the \"expert columnist\" said that you'd need to drink about 100 cups of coffee in a day for that to happen.",
"Since caffeine is an upper, you'd more than likely have a heart attack, or suffer another problem that results from massive over-stress of the body's systems. More than likely, you'd die with that kind of overdose.",
"You die. And are apparently miserable and in pain until you do.\n\n_URL_0_",
"I witnessed a coffee drinking contest in college. I friend of mine won by drinking 17 cups in 30 minutes. Then she had to go to the hospital to get her stomach pumped due to caffeine poisoning. The ER docs were particularly unimpressed, as I recall.",
"I remember an article with a reader asking if it was possible to ingest a lethal dose of caffeine, and the \"expert columnist\" said that you'd need to drink about 100 cups of coffee in a day for that to happen.",
"Since caffeine is an upper, you'd more than likely have a heart attack, or suffer another problem that results from massive over-stress of the body's systems. More than likely, you'd die with that kind of overdose.",
"You die. And are apparently miserable and in pain until you do.\n\n_URL_0_",
"I witnessed a coffee drinking contest in college. I friend of mine won by drinking 17 cups in 30 minutes. Then she had to go to the hospital to get her stomach pumped due to caffeine poisoning. The ER docs were particularly unimpressed, as I recall."
]
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"http://articles.nydailynews.com/2010-11-03/news/27080105_1_caffeine-red-bull-powder"
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"http://articles.nydailynews.com/2010-11-03/news/27080105_1_caffeine-red-bull-powder"
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|
755m4f | why are audio jacks round while charging and other ports are rectangular? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/755m4f/eli5_why_are_audio_jacks_round_while_charging_and/ | {
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"Audio jacks and *some* charging ports use so few wires that they were able to use a \"coaxial\" round design. This enables them to be connected in any orientation, and to rotate freely in the socket, both of which are advantages.\n\nThese connectors don't work well for digital data (the rotation can screw up the connection momentarily) or for cables requiring more than about 4 wires to be connected.",
"With an audio jack the contacts are arrayed down the length of the plug, meaning the first contact could connect with every other contact along the way in or out. Pumping charging voltage down a data line is a bad idea. ",
"It's largely a result of how many connections there are. Headphones originally had 2 connections, signal and ground. They've expanded to 3 (stereo and ground) or 4 (plus mic) while keeping the historical form factor. Lots of power connections are round as well (barrel plugs) as are old video connections (coax and RCA plugs) \n\nThe trouble is when you get lots of connections to be made in a plug, you need to line up the wires right. That's easiest to do if there's only a single way the plug goes in. Hence rectangular, non-rotatable plugs. ",
"Because they always have been, really. The phono connector has been around for at least 130 years, to the point where I don't believe anyone knows who made it first. It's really cheap and easy to manufacture, and always has been. It's literally a tube of brass or gold, the tip can be made by pinching another tube. The jack itself is a flimsy piece of metal spring from bent/stamped sheet metal. You can make a jack in your garage with a few metalworking tools that have been around for centuries, it's not rocket science. \n\nIt does have few distinct disadvantages that have rendered it obsolete for other tasks. But keep in mind there are many other round connectors out there like DIN and XLR. Rectangular plugs have only become popular with the advent of cheap and tiny flat copper strips, which are necessary for low profile connections. "
]
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||
1t8b6q | how come when i smoke a cigarette it calms me down even though my heart rate is higher? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1t8b6q/eli5_how_come_when_i_smoke_a_cigarette_it_calms/ | {
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"_URL_0_\n\nA bit more detail than that article. Higher concentrations cause calming effects. Lower concentrations tend to cause a stimulating effect.\n\nThe calming effect is due to it's heightening effect on serotonin and opiate pathways.",
"the process of inhalation and exhalation of smoking is at a much deeper rate than normal breathing, taking slower, deeper breaths relaxes the body, as it \"slows your body down\""
]
} | [] | [] | [
[
"http://www.sciencedaily.com/releases/2009/04/090423193946.htm"
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||
ayuvf5 | Can your bladder and stomach shrink/grow in size depending on the amount of food and liquid you consume? | [deleted] | askscience | https://www.reddit.com/r/askscience/comments/ayuvf5/can_your_bladder_and_stomach_shrinkgrow_in_size/ | {
"a_id": [
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"text": [
"Your bladder will stretch. However, it's the stretch that stimulates the urge to urinate, so you can only hold on so long. There is a limit to the stretch.\n\nYour stomach is actually folded on the inside, as you fill it up it unfolds, allowing it to expand. Your stomach will also grow if you are eating huge amounts all the time, or if you have a anatomical problem which restricts stomach emptying. They can get huge."
]
} | [] | [] | [
[]
] |
|
5k8q2j | What happened to German leaders once Germany was formed? | Although Prussia was easily the largest and strongest state when Germany formed,were other grand dukes, kings, counts, and so forth, given positions of power once Germany formed? Did they keep their titles? Continue ruling over their lands? Or were they forced to abdicate their lands and positions? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5k8q2j/what_happened_to_german_leaders_once_germany_was/ | {
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"The long and the short of it was that German rulers and principalities kept their titles and positions after the declaration of the German Empire in 1871. The *Kaiserreich* was a federal system, as seen in [this map](_URL_1_) with the various German polities as states within this federal system. Prussia did annex some some German states in the aftermath of the Austro-Prussian War, as seen in this (ugly) [map](_URL_0_) in light blue. These polities had largely backed the losing side in the war and some, such as Frankfurt am Main, had a strong tradition of liberalism that was at odds with both Bismarck and Wilhelm I's archconservative tendencies. But the elites of these regions did not go away completely and were often amalgamated with Prussian administration, albeit with a good deal of tensions, over the course of 1866-1918. For the German polities that joined the empire in 1871, their participation in this federal union meant subordinating themselves to Prussian suzerainty. The King of Prussia was also the German Emperor- a subtle distinction- and was in this constitutional order a first among equals. The Kaiser was commander in chief of the German armies in wartime and the German entities were to subordinate themselves to Prussian institutions like the General Staff. The monarchs and rulers sent deputies to the *Bundesrat*, a federal council with neofeudal trappings that in theory the constitution invested with great powers, but in practice was relatively toothless. The federal states maintained their own restricted form of sovereignty; the larger states had their own armies and local parliamentary bodies. The various monarchs adapted to this restricted political power with some degree of alacrity. Many of them took on the trappings of what historians term \"bourgeois monarchy\" in which the monarch was not some remote figure out of time, but rather a cultured individual of the people. These monarchs would preside over festivals and cultural patronage that enhanced the local distinctiveness of the region. Some German monarchs such as the later Wittelsbach rulers and the Saxon kings were arguably more popular in their domains than the Kaisers. Although the German Revolution meant an end to monarchy in Germany, more than a few non-Prussian monarchs remained in their territories. They may have abdicated their political power, but they retained a sheen of cultural power that was quite lasting. The same could not be said of the Hohenzollerns, which outside of a few circles of Prussian-dominated institutions like the military, were *persona non grata* in the Weimar Republic. "
]
} | [] | [] | [
[
"https://upload.wikimedia.org/wikipedia/commons/d/d9/Ac.prussiamap3.png",
"https://upload.wikimedia.org/wikipedia/commons/d/d5/Deutsches_Reich_%281871-1918%29-de.svg"
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2y4o1i | how can scientists use galaxies and other systems as lenses to see further in the universe? | Question following this [NYT article] (_URL_0_). | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2y4o1i/eli5how_can_scientists_use_galaxies_and_other/ | {
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"It's a process called gravitational lensing. When an object has mass it warps spacetime. How does it do that? Well pretend the universe is like a 2D bedsheet. If you suspend that bedsheet over a hole in the ground and put a small weight in the middle the sheet would sag down, creating an indent in the fabric. \n\nThis is essentially what objects with mass do to spacetime. The exact process behind this is pretty complex particle physics and isn't hugely relevant or necessary so just accept that it happens, like with our bedsheet.\n\nIf you were to roll a ping pong ball from one edge of the fabric along to the other end of the fabric in a straight line it would bend its path as it passed around the indent. If you were to repeat this at the same speed at the other side of the same edge of the sheet (this is hard to describe without images but I hope you get what I'm saying) it will bend the other way. If you were to plot the balls path they would cross at a certain point behind the central mass.\n\nThis is essentially what a gravitational lens is. The sheet is spacetime, the mass is a large cluster or galaxy, something with a lot of mass, the balls are photons of light and the meeting point of the lines is where we are looking from. \n\nSee the following image, it will work hand in hand with my description to explain it\n\n_URL_0_"
]
} | [] | [
"http://www.nytimes.com/2015/03/06/science/astronomers-observe-supernova-and-find-theyre-watching-reruns.html?partner=rss&emc=rss&smid=fb-nytimes&bicmst=1409232722000&bicmet=1419773522000&smtyp=aut&bicmp=AD&bicmlukp=WT.mc_id"
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"http://i.space.com/images/i/000/027/142/wW4/gravitational-lensing-distant-star-forming-galaxies-1920.jpg?1363617207"
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|
71qupu | how do power wires stay the same voltage when so many different homes and companies are drawing power from them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/71qupu/eli5_how_do_power_wires_stay_the_same_voltage/ | {
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"they don't stay same voltage. if you measure it, you'll see the voltage go up and down at a fixed position. if you move you'll also see it varies with wire distance to the distribution node. power companies are always monitoring the voltage levels and adjusting the power generators to match the expected demand. ",
"Voltage doesn't drop much because all devices are hooked up in parallel. Regardless of the number of devices in a circuit, the voltage will remain the same across the devices if hooked in parallel. Its the current, measured in amps, that will keep adding as more devices are added on in a parallel circuit. "
]
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[],
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||
ss3il | +r vs -r, when it comes to cds and dvds. | I will give you karma. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ss3il/eli5_r_vs_r_when_it_comes_to_cds_and_dvds/ | {
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"text": [
"DVD-R was created by the DVD Forum, the official group behind the DVD standard, in 1997. The hyphen is just a hyphen, not a minus sign, similarly to CD-R.\n\nIn 2002, a group of companies led by Sony decided they could do a better job, and so made DVD+R. The main difference is that DVD+R is better at avoiding and correcting errors, both during reading and burning. \n\nNowadays most DVD players/burners can handle both, so it doesn't really matter. But if you have to give a disc to someone with an old DVD player, -R will have a better chance of working.",
"Pity the fool who bought DVD-RAM"
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|
25okmw | Why does lightning have little electric branches that come off of the main bolt? | askscience | http://www.reddit.com/r/askscience/comments/25okmw/why_does_lightning_have_little_electric_branches/ | {
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"The little branches are not actually coming off of the \"main bolt\". Lightning starts in a two step process. Excess electrons accumulate at the bottom of a cloud. As charge builds in the cloud and a large electric field (~3,000,00 V/m) forms between the earth and cloud, the electrons will eventually gain enough energy to ionize the air and cause dielectric breakdown. \n\nAs breakdown occurs and the air becomes conductive, an initial flow of electrons from the cloud moves towards earth in a mostly unpredictable manner. The air may ionize equally in any direction and is affected by the shape of terrain, impurities in the air, etc. This is where the branching happens. Like others have said, the path of least resistance receives the most current, and eventually one of the branches will reach earth. \n\nOnce a branch reaches earth, there is now a complete path between earth and the cloud of ionized air that allows for the second phase of the strike to happen which is the massive release of charge from the cloud. This is the bright part that looks like the \"main bolt\". There's a lot more details you can read about but hopefully this answers your question."
]
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[]
] |
||
84vo4h | what are the concepts of intrinsic value and instrumental value in philosophy? | I've been reading about the dichotomy of the two, and it's been difficult to make sense of it in rather simple terms. What defines and separates the two? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/84vo4h/eli5_what_are_the_concepts_of_intrinsic_value_and/ | {
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"Intrinsic value is when I value something for itself. Instrumental value is the \"I can use this!\" sort of value. This is a tool that lets me better get what I want, so it's valuable to me.\n\nI value the well-being of those I care about, for instance. Is this so I can get something else? No, I just want them healthy. I might admire an art and want it around because I like it, and not because I can use it to get or do something else.\n\nI value having shoes because they help me get to work -- shoes are a tool that gets me to work better. I value work because it's a tool that gets me money that's a tool that I can use to get shelter and food and healthcare and stuff.\n\nIt gets a bit fuzzy between \"I want this because it will have a mental effect on me\" and \"I want this for itself\". I tend to be a bit generous here -- for instance, I have a cute hair clip, and I value it because it helps me look cute. That's pretty close to the outside world / internal mind divide, so I'd say that I intrinsically value that hair clip. But another person might say that my intrinsic value is on being cute, or feeling like I'm cute, and the hair clip is a tool that helps me achieve that goal. Except it was also a gift from my spouse, so I value it for that reason too. Things are complicated.",
"Say the only thing want in the world right now is some chocolate.\n\nThat has intrinsic value, it's all you currently value. But there's a second class of things you value, things that allow you to get chocolate.\n\nSo in this situation money would have instrumental value, because it allows you to buy chocolate.\n\nSo you want money, _but_ you only want money to get chocolate. That's the difference.\n\n\n"
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[],
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548fjn | Is an inertial dampener entirely science fiction? Or is there a theoretical way to actually make one? | askscience | https://www.reddit.com/r/askscience/comments/548fjn/is_an_inertial_dampener_entirely_science_fiction/ | {
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"Remember Newton's second (and first) law, F=ma. Changing the inertia (the resistance to acceleration due to a force) of an object is the same as changing its mass, so \"inertia\" and \"mass\" are basically two different words for the same thing.\n\nSo, inertial dampeners are just a piece of [applied phlebotinum](_URL_0_) to justify the Enterprise and other starships working the way they do. When asked how the inertial dampeners work in an interview, one of the writers for ST:TNG responded \"just fine, thank you.\"\n\nHowever, the point of an inertial dampener is to reduce the force the passengers in a vehicle are experiencing, and although we can't do that in real life by reducing the mass, we can do it by reducing the acceleration by increasing the time over which the change in velocity occurs. So an example of a real world \"inertial dampener\" would be a shock absorber."
]
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[
"http://tvtropes.org/pmwiki/pmwiki.php/Main/AppliedPhlebotinum"
]
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||
3unisx | why did africa's/australia animals evolve to be so deadly compared to other animals around the world? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3unisx/eli5_why_did_africasaustralia_animals_evolve_to/ | {
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"In Africa animals had a lot more time to adjust to humans than in other places. They learned eventually to avoid humans.\n\nAustralia used to be full of weird giant animals, but by the time humans made it to Australia they were already master hunters. Humans wiped out most of Australia's big animals in a very short amount of time. The only ones that survived were either too fast or too mean to eat."
]
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||
crs5j9 | How would doctors handle a prolapsed anus before modern medical intervention? | This isn't a particularly deep question or anything but while driving to get pizza this night of nights my mind happened to wander to the concept of the prolapsed anus. Being a person who studies mainly cultural history, but not at all medical, I have never encountered a prolapsed anus in any historical accounts. So, does anyone know? How would doctors handle a prolapsed anus before modern medical intervention? Is a prolapsed anus a modern phenomenon? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/crs5j9/how_would_doctors_handle_a_prolapsed_anus_before/ | {
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"It is not a modern phenomenon; rectal prolapses can occur in infants who have problems with constipation or diarrhea. Medical history is not my specialty so I don't know the full history of the condition. But because of the aforementioned reason, it was included in Nils Rosén von Rosenstein's 1764 textbook _Underrättelser om barns sjukdomar och deras botemedel_ (English title: _The diseases of children, and their remedies_ ), which was a popular book, translated into 10 languages in the 18th century, which is considered history's first textbook of pediatrics. It doesn't seem to be digitized yet but I have [a photo of the relevant page](_URL_1_). It reads in full (my translation):\n\n > §3 On the falling out of the rectum.\n\n > When children have diarrhea, it often happens that the rectum goes out, which then becomes a habit if not cured immediately. I have not found a better cure against this, than to dab it with a fine sponge, which has been dipped in warm wine. Fine soot, or crushed and sifted bark usually helps as well, when strewn upon the intestine which is then carefully [re-]inserted. Likewise it is good to smoke the intestine with [mastic](_URL_2_).\n\nRosén does not explain his rationale for these treatments, but they seem fairly straightforward in terms of the Humorism thinking of the time, where the body was governed by the balance of four 'humors' or bodily fluids. In that model, diarrhea means an excess of moisture, or phlegm. I.e. the patient is _phlegmatic_ (a term that lives on not for the diarrhea but the mental states they associated with the condition). The 'cure' for an excess of moisture is then to administer things that are _dry_, such as the dry powders and smoke. \n\nOn a related note, the administering of tobacco-smoke [enemas with bellows](_URL_0_) to drowning victims would become a common practice in about the same period. Since drowning is, when viewed through the lens of humorism, another problem stemming from an obvious excess of moisture.",
"Short answer:\n\nThere's a kingly *gloire* to the history of proctology, and while we only have about two centuries of historical documentation for the treatment of rectal prolapse, there's good reason to think that treatment has been attempted for much longer as we do know that disorders of the rectum generally have been treated since antiquity.\n\nDiscussion:\n\nNo discussion of historical proctology can begin without mention of Louis XIV's fistula, treated by a surgery without anesthesia which was the talk of society; Lully conducted a *Te Deum* afterwards, and his physicians leave us a surprisingly detailed account in the *Journal de Santé du Roi*. A fistula isn't a prolapse, still, we know that physicians were devoting a great deal of attention to piles and other complaints of the area-- no reason to think that they didn't see a prolapse on occasion, the accounts we have are often anatomically vague and we can't always tell just which condition is being described.\n\nThe first description I can find for a specific treatment for prolapse is 1831; work of the pioneering surgeon Frederick Salmon. He discusses prolapse as distinct from intussusception, which appears to have been known to and treated by practitioners from antiquity (likely without success). Salmon founds “The Infirmary for the Relief of the Poor Afflicted with Fistula and Other Disease of the Rectum,” and he claims a surgical cure for prolapse, this seems to be the first recorded discussion of this as distinct from other complaints in the same area. Salmon makes clear that earlier physicians had seen and attempted to treat it, but had not properly understood the anatomy.\n\nGregory Tsoucalas, a contemporary (to us) physician and medical historian wrote recently of Salmon in *Surgical Innovation*\n\n > Although \\[Salmon's\\] work was too significant for the era, he was almost completely neglected by historians, most probably due to his clash with his fellow surgeons, who had been considered by him as scientifically inadequate in anorectal diseases.Frederick Salmon succeeded to present a pioneering restoration of the rectal prolapse, announcing zero fatality. Despite his persistence toward the hepatic “cure,” his observations about the causes and symptoms show great similarity with the modern views. Salmon is now considered as one of the most important figures in proctology.\n\nProlapsed rectums are not exclusively \"modern phenomena\", indeed they're not exclusively human phenomena, veterinarians see them too.\n\nWhile we don't have a discussion of Hippocrates or other classical physicians treating rectal prolapse, we do know that they did proctology. We have Hippocrates' \"*On Fistulae*\" as evidence of their familiarity with and treatment of these conditions, and we have specula and dilators from classical antiquity which were used to treat complains of the anus and rectum. So although we don't have a specific description of their use in prolapse, we do know that physicians of classical times were treating other conditions affecting the same parts.\n\nThe celebrated 14th century English surgeon John of Arderne treated fistula as well:\n\n > I cured a man from Northampton of the aforesaid Fistula in ano who bad three openings in the left buttock and three in the cleft of the scrotum as is here depicted, and all in turn communicated the one with the other and had perforated through the middle of the scrotum. I cured him by incision of all the holes, both in the rectum and elsewhere.\n\nNone of these early physicians and surgeons give us a clear description of a prolapse; the most we can say is we know that they must have happened, we know that patients are symptomatic and would be likely to seek care, and that there were physicians who addressed proctological complaints generally.\n\nA search of sources in Chinese and Ayurvedic medicine doesn't turn up much-- the *Wu Shih Erh Ping Fang (*\"Prescriptions for Fifty-two illnesses) of 168 BCE has a discussion of hemorrhoids, though we can't be sure that nomenclature doesn't include prolapse and other disorders. In the Islamic world, al Tabari, the great scholar of the 9th century CE has a compendium of medical literature (\"The Paradise of Wisdom\") which includes a section on diseases of the anus and fistula in particular.\n\nSo: Before 1820, we can't find a clear description of a treatment for rectal prolapse-- if you were unlucky, it's possible that someone might have attempted surgery, which would be unlikely to have happy results. Fistulae and hemorrhoids are problems more readily addressable with the means that early physicians had at hand.\n\n**Sources**: \nWu, J. S. (2009). *Rectal Prolapse: A Historical Perspective. Current Problems in Surgery, 46(8), 602–716.* doi:10.1067/j.cpsurg.2009.03.006 \n\n*An Operation For Fistula In Ano Two Hundred Years Ago. The British Medical Journal*, Vol. 2, No. 247 (Sep. 23, 1865), pp. 310-311 \\[there are more modern sources for the story of the celebrated operation on Louis XIV, but this is colorful and correct as to details)\n\nSalmon F. *Practical Observations on Prolapsus of the Rectum.* London: Whittaker,Treacher and Arnot, Ave-Maria Lane; 1831; chapter I, p B.\n\n*The History Of Rectal Surgery. The British Medical Journal*, Vol. 2, No. 3699 (Nov. 28, 1931), p. 999\n\nTsoucalas, G. (2018). British Surgeon Frederick Salmon (1796-1868) and His “Trans-Fixing Pins and Excision” Surgical Procedure for the “Rectum Prolapsus.” *Surgical Innovation*, *25*(1), 88–89. [_URL_1_](_URL_1_)\n\nBliquez, Lawrence J. “Greek and Roman Medicine.” *Archaeology*, vol. 34, no. 2, 1981, pp. 10–17. *JSTOR*, [_URL_2_](_URL_0_).\n\nBliquez, Lawrence J, \"The Tools of Asclepius: Surgical Instruments in Greek and Roman Times\" \\[2014\\]"
]
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"https://i.imgur.com/3RaL3Kd.jpg",
"https://en.wikipedia.org/wiki/Mastic_(plant_resin\\)"
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"https://www.jstor.org/stable/41727119",
"https://doi.org/10.1177/1553350617731384",
"www.jstor.org/stable/41727119"
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1o2uyu | If the Vikings visited North America before 1492, was there any evidence that any population was wiped out (partially or otherwise) by small pox? | I find it strange that the 1492 colonization could (theoretically) wipe out the continent but the Vikings visitation did not. Did they not make contact with other humans? Did they not carry the virus? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1o2uyu/if_the_vikings_visited_north_america_before_1492/ | {
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"[Smallpox didn't arrive in Iceland until 1241](_URL_5_), some two centuries after the Norse abandoned their North American colonies. In general northerly settlements, like those of the Norse and of the Native Americans and Inuits they encountered in North America, had two lines of defense against epidemic diseases. \n\nFirst, by a quirk of geography, they're frequently isolated from settlements further south. A person leaving Denmark carrying an epidemic disease would most often die before reaching Iceland, preventing the disease from spreading there. The same for someone traveling from Iceland to Greenland or Greenland to Vinland and so on. That changed in later centuries as ships became larger and faster, as the disease could spread to more hosts on board the ship and carry on to the destination.\n\nSecond, northerly settlements tended to be below the population density thresholds needed to sustain epidemic diseases. A small area might be completely depopulated in an Arctic region, but the disease would wipe out so many of its potential hosts that it has no where to spread to and dies out. That changed as northern cities became larger and travel between them became faster and more reliable--still well after the Norse abandoned their North American colonies.\n\nSo the Norse didn't have smallpox when they arrived in North America, and other potential epidemic diseases had significant hurdles that prevented them from becoming established in the region.\n\nAlso, check out these other threads on the topic (I'm shock to see how many there have been):\n\n* [If the Vikings landed in the New World, would there be some evidence that they brought disease with them? Does this evidence exist?](_URL_7_)\n* [Did the Vikings spread diseases to the Native Americans when they first explored North America?](_URL_0_)\n* [Did the Native Americans receive any diseases when they encountered the Vikings?](_URL_6_)\n* [Why didn't Viking contact with Native Americans result in such widespread death from disease as occurred when Europeans made contact in the 15th century?](_URL_2_)\n* [Why wasn't there a plague among Native Americans after contact with the Vikings?](_URL_3_)\n* [Did the Vikings in North America ever pass along devastating diseases to the native tribes living there?](_URL_1_)\n\nAnd that's just the first page of searches that included something more than a link to [the relevant section of our Popular Questions](_URL_4_)",
"When smallpox reached Iceland in 1241 it was devastating to the population there. Almost as devastating as it was to Native American Populations. \n\nThe Icelandic smallpox epidemic of 1241 killed about 20,000 people out of a total population of 70,000 people.\n\nSource: _URL_0_\n\nFurthermore, in Iceland, unlike more populous parts of Europe, small pox never became endemic, (because the population was too small and Iceland was too remote) so it remained an epidemic disease (much more deadly than an endemic disease) for centuries. Iceland had further severe smallpox epidemics in 1257 and 1291.\n\nAnother extremely deadly epidemic of smallpox in Iceland history came in 1707-1709 when 15,000 people out of 50,000 died. (You can also see that smallpox and plague epidemics in Iceland actually caused the population in 1707 to be less than it was in 1241.)\n\nSource: _URL_1_\n\nIceland is a good example of the deadly nature of smallpox epidemics, and they are much better documented in Iceland than they were amongst Native Americans. We can also see from the Iceland example, that the main protection Europeans had from smallpox was its endemic (not epidemic) nature in most of Europe (children died but adults who survived as children could not get it again, and could go on and have more children). \n\nGenetic resistance to smallpox in Europeans, was probably a lesser protection for population levels than the endemic exposure. Thus, Icelanders may have had some more genetic resistance than Native Americans (due to their European ancestry) but the fact that the population was too small to support endemic smallpox still left them horribly exposed to epidemic smallpox.\n\nThis also explains why Native Americans were devastated by smallpox again and again over hundreds of years. Any genetic resistance passed down by survivors was not very strong, and population densities (especially in N. America) were not high enough for the disease to become endemic in Native American populations, so it remained a very deadly epidemic disease to them.\n\nSmallpox seems to have originated in China in about the first century AD (there are some hypotheses that it originated in Egypt much much earlier).\n\nIt came into Europe as epidemics in about the 5th or 6th centuries AD, and had become endemic in much of Europe by 1100-1200.\n \nWhen smallpox spread into the Americas it was particularly deadly. The initial epidemics in Cuba and Puerto Rico in 1518 and 1519 were said to have killed 50% of the Native population. The first epidemic in Mexico in the 1520s was also said to have killed 50%. In North America, there was a great smallpox epidemic in New England in 1617-1619. It killed some very high proportion of the population. When the Mayflower Pilgrims arrived in 1620, they found a very de-populated land.\n\nJust like in Iceland, the smallpox did not strike just once. It kept coming back as epidemics again and again. In highly populated regions of Meso –America or South America, it eventually (in the 1600s-1700s) became endemic (which actually protects the populations more than if it remains epidemic). \n\nIn North America, populations were less dense, and smallpox remained an epidemic disease. This meant that just like in Iceland, it continued to strike, and population levels continued to decline. Unlike in Iceland, where mortality rates in a bad epidemic seem to have been about 30%, mortality rates in a bad epidemic in the Americas seem to have been about 50%. This is a significant difference, and explains why Native American populations declined much more severely over time than the Icelandic population.\n\nThis decline only began to slow or stop once the disease became endemic (in more densely populated areas) or after vaccines became available.\n"
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"http://www.reddit.com/r/AskHistorians/comments/1ko5h9/did_the_vikings_spread_diseases_to_the_native/",
"http://www.reddit.com/r/AskHistorians/comments/u39xi/did_the_vikings_in_north_america_ever_pass_along/",
"http://www.reddit.com/r/AskHistorians/comments/1cnk4d/is_there_any_facts_to_back_up_the_claim_that/",
"http://www.reddit.com/r/AskHistorians/comments/ysroh/why_wasnt_there_a_plague_among_native_americans/",
"http://www.reddit.com/r/AskHistorians/wiki/nativeamerican#wiki_native_americans_and_.28european.29_diseases",
"http://whqlibdoc.who.int/smallpox/9241561106_chp5.pdf",
"http://www.reddit.com/r/AskHistorians/comments/18vlom/did_the_native_americans_receive_any_diseases/",
"http://www.reddit.com/r/AskHistorians/comments/1nkkmv/if_the_vikings_landed_in_the_new_world_would/"
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"http://www.fofweb.com/History/HistRefMain.asp?iPin=ENPP267&SID=2&DatabaseName=Modern+World+History+Online&InputText=%22Icelandic+smallpox+epidemic%22&SearchStyle=&dTitle=Icelandic+smallpox+epidemic&TabRecordType=All+Records&BioCountPass=0&SubCountPass=1&DocCountPass=0&ImgCountPass=0&MapCountPass=0&FedCountPass=&MedCountPass=0&NewsCountPass=0&RecPosition=1&AmericanData=&WomenData=&AFHCData=&IndianData=&WorldData=Set&AncientData=&GovernmentData="
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l57zy | How dangerous are portable electronic devices to planes? | We've all been through the "turn off your cellphones and laptops" announcements on planes, but how dangerous are they, if at all? I can understand how transmitters like radios or portable televisions could cause interference, but is there a risk from things like iPods or cellphones? Is there anything besides anecdotal evidence for these rules? | askscience | http://www.reddit.com/r/askscience/comments/l57zy/how_dangerous_are_portable_electronic_devices_to/ | {
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"Radios and portable televisions are receivers, not emitters, so they can't have any effect.\n\nIpods don't have any antenna, they don't have any influence.\n\nCellphones on the other hand emit signals. However, nowadays, interference between these signals and the plane's systems is non-existant. This has been proven, but there's still scepticism because in aviation you don't take that kind of risks.\n\nThere are several other reasons why they forbid them:\n\n- At take-off and landing, you shouldn't be distracted by anything. These are the most dangerous phases of the flight, and passengers need to be able to listen and comply with the crew instructions. This is why all electronic devices (including mp3 players) are forbidden there.\n\n- Cellphones are useless in flight, since you don't have any network. Therefore you can use \"airplane mode\" and not emitting anything. No drawbacks and no debate about interferences.\n\n- Most airlines and travellers do not want cellphones to be authorized because it is annoying for other passengers.\n\nWith the development of in-flight wifi, it would be possible to bring a phone network in the plane. There are studies done to show that's it's not dangerous. The administration is discussing (for quite some time now) the possibility of legalizing it and letting airlines choose, but it's not done yet.",
"Radios and portable televisions are receivers, not emitters, so they can't have any effect.\n\nIpods don't have any antenna, they don't have any influence.\n\nCellphones on the other hand emit signals. However, nowadays, interference between these signals and the plane's systems is non-existant. This has been proven, but there's still scepticism because in aviation you don't take that kind of risks.\n\nThere are several other reasons why they forbid them:\n\n- At take-off and landing, you shouldn't be distracted by anything. These are the most dangerous phases of the flight, and passengers need to be able to listen and comply with the crew instructions. This is why all electronic devices (including mp3 players) are forbidden there.\n\n- Cellphones are useless in flight, since you don't have any network. Therefore you can use \"airplane mode\" and not emitting anything. No drawbacks and no debate about interferences.\n\n- Most airlines and travellers do not want cellphones to be authorized because it is annoying for other passengers.\n\nWith the development of in-flight wifi, it would be possible to bring a phone network in the plane. There are studies done to show that's it's not dangerous. The administration is discussing (for quite some time now) the possibility of legalizing it and letting airlines choose, but it's not done yet."
]
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fs376u | Did Prussia win the Franco Prussian war, or did France lose it? | According to The Franco Prussian War: The Prussian Conquest of France by Geoffrey Wawro, or at least from my understanding of it a significant part of the Prussian victory was due to the abysmal showing by the French. From barely having maps of their own territory to declaring a war and waiting for the Prussians to attack, as well as inferior canons mitigating their small arms advantage.
Could a healthy, prepared France have measured up against the Prussians? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/fs376u/did_prussia_win_the_franco_prussian_war_or_did/ | {
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"Tl:Dr; Prussia won, disclaimer: on mobile\n\nTo think that France was some dithering dolt of a Nation is wrong. France was one of, if not the, premier Nations for land wars. \nThey had fought a series of successful campaigns over the last 3 decades. To most of Europe this was Frances fight to lose. \nPrussia, had fought to wars in the same time period and having both relatively short. Their victory over Austria was surprising but France was still impressive. Then why did Prussia win so handedly? Simple, they were fighting different kinds of war. France was fighting like a mid century army would. \nPrussia was fighting how wars would be fought until the great war, and Prussia was ready. \n\nWhy was Prussia ready? Helmuth von Moltke. Why is he so important? Because he reorganized the Prussian army with ideas and systems that would be emulated by every army since. \nWhat are some of the things? How impactful were they? \n\nYou know that scene in just about any war movie where the general in looking over a map of the area planning. That didn't happen, until the von Moltke. He wanted maps of everywhere, so they would have ahead of time. They could just make copies as need. Did anyone else do this? No. Did they start after the Franco Prussian war? Yes. The great irony of this is that the Prussians offered to show the Austrians this, but after asking if they played for money and being informed no, the Austrian officers said they weren't interested\n\nWith these maps ol' vM made plans ahead of time, taking the decision making process out of the equation. The best generals had all the time they needs with maps of everything to figure out the best approach. \nDid anyone else do this? No. Did they start after the Franco Prussian war? You betcha\n\nDid these plans include logistics that were so detailed they needed a whole Corp of military bureaucrats to manage it. Yep, and did anyone else bother having trained officers who whole job was desk work? One guess! \n\nPrussia literally build infrastructure to better conduct war. Moltke invested two track logistics. He invented rolling logistics.\nWhen the French showed up in Italy for the second war of Italian unification, there was a disaster of logistics, too much of some stuff, not enough of others. The Prussians on the other hand would ship men with all of the needed equipment. This allowed for soldiers to begin moving out immediately, unlike the French who would have to wait for supplies. \n\nThese are just some examples of how Prussia had a military system that out matched the French in the new ways or innovative was. The French didn't have maps, but Prussia was the only one who did. \n\nI hope this makes sense, if you have any questions please let me know."
]
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3q8skl | Why did Islam turn inwards after the Mongol invasion? | I read that the Islamic world turned inwards/became isolationist as a result of the Mongol invasion. Was this reaction peculiar to Islam? Did India and China experience similar developments as a result of Mongol rule? Did the area benefit in any way from from the silk road, did the Mongol rule have any positive aspects for the region? What have the Mongols ever done for us?
| AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3q8skl/why_did_islam_turn_inwards_after_the_mongol/ | {
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"I think the characterization of Islam as \"turning inwards\" is an interesting one that has to be understood in context.\n\nIn one sense, the empires of Islamdom after the Mongols were, if anything even more vigorous in their outward conquests. The Ottomans, the Safavids and the Mughals, the three main \"gunpowder\" empires of Islam in the centuries after the Mongols, all conquered huge swathes of territory, particularly the Ottomans in the Balkans and towards central Europe and the Mughals into India.\n\n(As an aside, Ottoman Europe I think is misunderstood. Because the siege of Vienna was so much later I think there's a popular thinking or assumption that their European territories were somehow the product of a great buildup that came after consolidating the Middle East. Actually it was the other way around, the Balkans and Greece were integral Ottoman territories almost a century before they would conquer the bulk of their Arab territories.)\n\nAside from military conquest these were also vigorous and prominent international powers who were deeply involved in international trade and diplomacy.\n\nSo *Islamdom* didn't really have any inward turn to speak of.\n\nIntellectual Islam, however, as a religion and incubator of philosophical thought, has been characterized after the Mongol conquests as having an inward turn after the Mongols.\n\nTo a certain extent some of this thinking predates the Mongol conquests. One of the most prominent thinkers of this inward turn or trend was Al-Ghazali, who produced what is today regarded as the work of Islamic anti-rationalism par excellence *The Incoherence of the Philosophers* in the 11th century. \n\nPerhaps ironically, the other roots of this can be found in the so-called \"Sunni Revival\" of the 11th and 12th centuries. This is a large topic on which there is much debate as to whether or not it even occurred (comparable to the European renaissance in some senses) but suffice it to say that as an intellectual movement these centuries produced a largely homogeneous orthodox consensus within Sunni Islam and amongst Sunnis.\n\nSo why are the Mongol Invasions important if this was already happening? Well, for one thing it was not at all clear before the Mongols arrived on the scene that these ideas would prevail. Ghazali was fired from his teaching position for pushing his theological (as opposed to legal) views on his students. And Ibn Rushd in the 12th century published what might be the best titled reply in all of history when he wrote *The Incoherence of 'The Incoherence'*.\n\nOne of the reasons why this can be difficult to write about is that even this can be overstated. Ibn Rushd as the last major philosopher of classical Islam himself fell out of favor for his views, and lived in the extreme periphery of Islamdom.\n\nSo a lot of this history gets muddy, after all it's very difficult to write a history of how an entire religion or culture reached a broad consensus on adopting an intellectual position vis a vis outside influence, but the Mongols are often written as being critical. By creating a century of utter chaos in the intellectual center of Islamdom, you go from a period where Islam has a vibrant intellectual life in the 12th century to an almost total retreat into existing religious law and rejection of scholasticism or attempts to merge philosophy and religion.\n\nIn other words, as a famous phrase in the field goes, following the Mongol conquests the \"Gates of Ijtihad [individual reasoning]\" were firmly closed.\n\nA critical figure in this transition was Ibn Taymiyyah in the 13th and 14th centuries. Drawing on the work of Al Ghazali, Taymiyyah espoused an ultra conservative (\"inward\" as you might say) form of Islam that totally rejected not just philosophy but the entire field of theology as well. As with Ghazali I think this can easily be misunderstood, because today we might term all of this as \"theology.\" Rather, Taymiyyah and Ghazali rejected Islamic religious philosophy as in their view it had no basis in the traditions or the Quran. So the kinds of theological questions being asked, for instance, by the Scholastics like Aquinas were rejected as innovation and instead Taymiyyah called for a return to and reliance on the internal traditions of Islam. I think you could make the case for Ibn Taymayyiah and Al Ghazali between them being the most influential \"philosophers,\" though of course they would utterly reject that term, in Islamic history.\n\nSo the TL;DR is **Islamic empires did not become isolationist after the Mongols, but there's a case to be made that Islamic thinking did.**\n"
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3rz7h9 | why are people upset over red starbucks cup? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3rz7h9/eli5_why_are_people_upset_over_red_starbucks_cup/ | {
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"It's part of a larger \"War on Christmas\" argument that get's brought up every year. Over the last several years, companies have done different things to make the holiday season more inclusive for everyone. The big one was getting workers to say \"Happy Holidays\" to customers instead of \"Merry Christmas\" since not everyone celebrates Christmas. This pissed a lot of people off who viewed this change as trying to get rid of Christmas. The red Starbucks cup is seen as another example of that. Usually, Starbucks changes their white cups to red around this time of year and it usually has some sort of wintery or Christmasy design on it. This year, it's just solid red and Starbucks has been accused of taking Christmas off of their cups. "
]
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[]
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||
24eki9 | why do software companies have a day one patch for downloadable software? | Why don't they just update the installer? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/24eki9/eli5_why_do_software_companies_have_a_day_one/ | {
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"Because the discs were pressed weeks before the software release date, so it would have time to go out to retailers. That means that any disc-based version of the software is necessarily several weeks out of date by the time it gets to you. And they don't typically update the installer because it's easier to test things when you only have one configuration (the original installer + patches) rather than two (original installer + patches and updated installer). "
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49slgk | With the Banach-Tarski paradox, isn't right up left the same as just up? | In this video around 13:40 _URL_0_ Vsauce is talking about points on a circle. He puts a dot at right up left and up but shouldn't those be the same position? He says nothing about the distance of each direction and I'm so confused. If the distance is not fixed, then there should be up, up, up, etc forever since up up would be redundant. Just one up could stand for all of them. | askscience | https://www.reddit.com/r/askscience/comments/49slgk/with_the_banachtarski_paradox_isnt_right_up_left/ | {
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"Just setting aside Banach-Tarski, which is heavy stuff... let's just answer your title.\n\nRotations in 3D are non-abelian, in other words noncommutative.\n\nJust do it yourself physically: take an object (e.g. a book) in front of you. Place it in a given \"reference\" starting orientation of your choice. \n\nRotate it clockwise 90° about the vertical axis, then 90° about the horizontal axis, then 90° counterclockwise again about the vertical axis.\n\nThen start all over again in the reference orientation, and rotate it 90° about the horizontal axis.\n\nYou can see you don't get to the same final configuration.\n\nThe point here perhaps is that you cannot study rotations by only examining their action on a single point on a sphere. There is an ambiguity because many different rotations can do the same thing to one given point. You need to track the motion at least two points to unambiguously know what rotation you're performing.\n\nP.S.: if I remember the video correctly he is trying to explain the embedding of the free group with two generators in SO(3) (in fact two generic rotations of SO(3) will generate the free group). For this fact to be even possible, noncommutativity of SO(N) is essential and that's why the BT paradox needs at least 3 dimensions.",
"The important point here is to remember that the circles of latitude on a sphere don't have the same radius.\n\n[Here](_URL_0_), you start at the equator. You go right 1km, then up 1km. But when you go 1km left, you are no longer on the equator, and you would go beyond the first point."
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6p49hm | Is it possible to create visible light by the interference of infrared and ultraviolet light? If yes what would we see? | askscience | https://www.reddit.com/r/askscience/comments/6p49hm/is_it_possible_to_create_visible_light_by_the/ | {
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"Using nonlinear optical crystals and high powered laser systems it is possible to mix frequencies (e.g. sum frequency generation, wave mixing, etc.). This is how lasers can achieve specific frequencies depending on applications."
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4vcfw2 | Why can I see reflections on mirages? | Why can I see the reflections of cars and trees on mirages if there is nothing there? | askscience | https://www.reddit.com/r/askscience/comments/4vcfw2/why_can_i_see_reflections_on_mirages/ | {
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"Mirages occur because the air just above the ground is hotter than the surrounding air, and therefore it also has a lower index of refraction than the surrounding air. Light rays coming in at a glancing angle are then [totally internally reflected](_URL_0_). \n\n[This image](_URL_0_#/media/File:Mirror_like_effect.jpg) clearly demonstrates how total internal reflection can act like a mirror, as does [this one](_URL_0_#/media/File:Total_internal_reflection_of_Chelonia_mydas.jpg)"
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2fq71f | why exactly is benghazi such a big deal? | I understand what happened to the embassy over there and the folks in it and that sucks, what is with all the constant finger pointing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2fq71f/eli5_why_exactly_is_benghazi_such_a_big_deal/ | {
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"Because an ambassador (i.e the human representation of America oversees) was killed and that makes it a big deal no matter who was responsible. ",
"There were warnings from Ambassador Stevens sent to the State Dept. about an increase in threats. More security was requested and denied by Hillary Clinton, although she denies that she personally was responsible. The anniversary of 9/11 should have been an obvious reason for heightened security. The following cover story about an internet video was embarrassing to say the least, and now soldiers are claiming they were instructed to stand down in an attempt to help. This claim has also been denied by the administration. It is important to know what exactly happened in order to learn how to avoid it in the future, but the current administration simply wants it to disappear.",
"Certain elements of the American public believe that higher ups in the government are directly to blame for the deaths that occurred, and that it needs to be pursued no matter what various reports say, how long it takes, and how much money is spent. \n\nAlso, it's beneficial to some, to keep the controversy alive due to all of the political maneuvering over this, because of how strongly people believe, and how people will vote depending on where you stand on the issue.",
"Because mid term elections are coming up. 28 Americans were killed in embassy attacks during the Bush II administration but no one gave two fucks. ",
"Because Republicans can use it as a cudgel against Clinton and Obama at the same time. Two for one bullshit \"scandal\"!",
"Its important to learn from our mistakes aw we don't want the same thing to happen again. To do that, we need to understand what happened. \n\nThe State Dept. and others have been difficult with providing information to congressional investigations.",
"The Republicans had a huge incentive to blow it out of proportion because, if it were true that facts were manipulated, it would not only make Obama look bad, but it would also hurt the likely Democratic presidential nominee for 2016, Hillary Clinton. \n \nUnfortunately for the Republicans, [many investigations](_URL_0_) have shown that nearly all of their allegations they have been throwing around have been more-or-less false. The only thing they've really got right is that the embassy wasn't properly prepared to deal with an attack.",
"This happened during the presidential campaign where Obama had been bragging that al Qaeda had been decimated. And to throw blame somewhere besides al Qaeda the administration tried to blame it on an obscure video to protect his presidential run. And also to protect a potential run by Hillary Clinton. The ambassador had requested more security and it was refused. So the Obama administration lied for political purposes. The administration were told very early that it was an orchestrated terrorist attack and not a spontaneous demonstration. It has been argued that if the people had known that was not just a demonstration gone bad but an orchestrated attack, Romney would have won the election. \n\nAnd to cover it up even more, the survivors of the attack have been prohibited from testifying. ",
"For a week following the event, administration officials had categorically insisted that the prime, if not only, cause of the attack was spontaneous anger over the anti-Muhammad film, The Innocence of Muslims. White House spokesman Jay Carney insisted that \"these protests, were in reaction to a video that had spread to the region.\". UN ambassador Susan Rice, when asked about the impetus for the attack, said that \"this began as, it was a spontaneous – not a premeditated – response to what had transpired in Cairo,\" and added: \"In Cairo, as you know, a few hours earlier, there was a violent protest that was undertaken in reaction to this very offensive video that was disseminated.\" In other interviews, she insisted that the Benghazi violence was a \"spontaneous\" reaction to the film.\n\nPredictably, and by design, most media accounts from the day after the Benghazi attack repeated the White House line as though it were fact, just as they did for the Bin Laden killing. Said NPR on 12 September: \"The US ambassador to Libya and three other Americans were killed in an attack on the US consulate in Benghazi by protesters angry over a film that ridiculed Islam's Prophet Muhammad.\" The Daily Beast reported that the ambassador \"died in a rocket attack on the embassy amid violent protests over a US-produced film deemed insulting to Islam.\" For many weeks after, numerous people believed – as though there were no dispute about it – that Muslims attacked the consulate and killed the US ambassador \"because they were angry about a film\".\n\nIt is always more enjoyable to scorn the acts of the Other Side than it is to acknowledge the bad acts of one's own. That's the self-loving mindset that enables the New York Times to write entire editorials purporting to analyze Muslim rage without once mentioning the numerous acts of American violence aimed at them (much of which the Times editorial page supports). Falsely claiming that the Benghazi attacks were about this film perfectly flattered those jingoistic prejudices.\n\nThen, there are the implications for the intervention in Libya, which Obama's defenders relentlessly tout as one of his great victories. But the fact that the Benghazi attack was likely premeditated and carried out by anti-American factions vindicates many of the criticisms of that intervention. Critics of the war in Libya warned that the US was siding with (and arming and empowering) violent extremists, including al-Qaida elements, that would eventually cause the US to claim it had to return to Libya to fight against them – just as its funding and arming of Saddam in Iraq and the mujahideen in Afghanistan subsequently justified new wars against those one-time allies. \n\nIf the killing of the ambassador were premeditated and unrelated to the film, then it vests credibility in the criticism that the consulate should have been much better-protected, particularly on 9/11. And in general, the last thing a president running for re-election wants is an appearance that he is unable to protect America's diplomats from a terrorist group his supporters love to claim that he has heroically vanquished.\n\nThe falsehood told by the White House – this was just a spontaneous attack prompted by this video that we could not have anticipated and had nothing to do with – fixed all of those problems. Critical attention was thus directed to Muslims (what kind of people kill an ambassador over a film?) and away from the White House and its policies. \n\n"
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2kzmuf | Who was the first person to be known "Around the World"? | Who was the first person to have international acclaim? To the point where their likeness would be recognized around the globe. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2kzmuf/who_was_the_first_person_to_be_known_around_the/ | {
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"If we define \"around the globe\" as every continent except Antarctica and just say that someone living there permanently being able to regocnize it is good enough, Jesus is a good guess. With the first colony in Australia in 1788 there would be people living on every continent recognizing the likeness of Jesus. "
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eio7a6 | Did the Bubonic Plague have any influence on the art of medieval Europe? Did it leave any legacy? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/eio7a6/did_the_bubonic_plague_have_any_influence_on_the/ | {
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"**Short answer:**\n\nYes.\n\n**Discussion:**\n\nfirst we have to get the dates straight. The \"middle ages\" is a name we give a period, sometimes it's useful, very generally it's from the fall of Rome to the fall of Constantinople; that's the thousand years from 476 CE to 1453 CE; other people may prefer different dates, but that's the ballpark.\n\nThe \"Bubonic Plague\" you're likely thinking of, often referred to as the \"Black Death\" to distinguish it from other plague events, occurs in the mid 14th century. So it essentially occurs at the very end of the period we call \"the middle ages\", and as such can't \"influence\" the art that came before it. There \\_were\\_ plagues earlier in the period, including the celebrated \"Justinianic plague\" (541-42 CE, affected the Byzantine empire), but they did not have as dramatic a demographic or social impact. The \"dead people lying in the street\" ugly plague that you're likely thinking of is the \"Black Death\".\n\nThis plague is then followed by subsequent outbreaks of plague in Europe, into the 18th century; but by that point we're well out of what anyone defines as \"the middle ages\".\n\nSo, bearing in mind that the event you're asking about occurs very near the end of the middle ages, did it have an influence on the artwork of this time?\n\nYes. We can see it in artwork -- the *danse macabre* / dance of death / memento mori. Starting in the 1420s we've got paintings -- many of the earliest now unfortunately lost-- devoted to the idea of the impermanence of life and the possibility that death looms everywhere. This subject proves very durable, inspiring artists from Durer to the present to paint \"Death and the Maiden\" for example; we've got five centuries of artists painting this subject, and we've even got music inspired by that painting (Schubert most notably).\n\nWe see it in literature -- Chaucer in *The Pardoner's Tale*, Boccaccio in the *Decameron.* And of course Petrarch (Francesco Petrarca):\n\n > In 1348, when Petrarch was forty-four, the plague suddenly removed several of his best friends, his chief patron, and his beloved Laura. In 136I, when it recurred, he lost his son and his closest friend. It is fair to say that the plague was an outer circumstance that made special demands on Petrarch's consciousness. Nino Sapegno sketches the role of Black Death in Petrarch's life: '. . . from the terror and sadness of those days, \\[he derived\\] a sense of weary self abandonment in God, and even more, a need to meditate on his past life from above and to judge it severely in its vanity'. Of the sonnets concerned with Laura's death, he says, '. . . there appears again that insistent examination of conscience, that concern with meditation and reflection which is the most profound source of poetry in the earlier part of the Canzoniere as well; and now it appears . . . with a more desolate and weary kind of harmony. The sense of death pervades these confessional passages and colors them with a languid sadness, lifts them finally to a supreme longing for peace.\n\nAs Petrarch is one of the key figures in the emergence of the \"humanistic\" sensibility -- as well as the modern Italian language-- the events which shaped his experience of existence, communicated through his writing, become an important part of the literary developments that collectively we call Renaissance humanism. Parenthetically its Petrarch who popularizes the term \"Dark Ages\" for the centuries prior to his life . . . but he did not think of himself as living in them; he might well argue that \"the middle ages\" ended in the 13th century, eg before the arrival of the plague.\n\nWe see it in music: there's advice from physicians that music may keep the plague at bay.\n\nWe see it in ecstatic public performances, like flagellants beating themselves in the streets, and various plays based on the *danse macabre.*\n\nThe topic is huge and depending on just where and when you're interested in, much more can be said, but your TLDR is \"Yes\", and these themes stay with us into the modern era, indeed into the present, even if the connection to the plague is sometimes lost.\n\nSo we have medieval instantiations, like Edgar Allen Poe's *The Masque of the Red Death -* although Poe doesn't say so explicitly, his details all suggest the plague which Petrarch lived through. And we have vaguer references, like photographer Robert Maplethorpe's celebrated self portrait with a cane carved into a skull. Some of these subsequent references are rooted in the plagues of the 14th century, but some are based on later plagues -- in Maplethorpe's case, he's appropriating old symbols for a modern plague, AIDS. Similarly, Daniel Defoe's celebrated *Journal of a Plague Year,* written in 1722 is \\_not\\_ about the medieval plague, but rather about an outbreak that occurred in London in 1665-- this was \"bubonic plague\", but presumably not the bubonic plague you were referring to in your question.\n\n**Sources:**\n\nBús, Éva. “‘Death's Echo’ and ‘Danse Macabre’: Auden and the Medieval Tradition of Death Lyrics.” *Hungarian Journal of English and American Studies (HJEAS)*, vol. 14, no. 1, 2008, pp. 83–93.\n\nGertsman, Elina \"The Dance of Death in the Middle Ages: Image, Text, Performance\" (Brepols:2010) \\[unfortunately out of print and very hard to find, ruinously expensive in the used book market).\n\nGertsman, Elina. “THE BERLIN ‘DANCE OF DEATH’ AS THE ‘LAST JUDGMENT.’” *Source: Notes in the History of Art*, vol. 24, no. 3, 2005, pp. 10–20.\n\nGIRARD, RENE. “The Plague in Literature and Myth.” *Texas Studies in Literature and Language*, vol. 15, no. 5, 1974, pp. 833–850.\n\nUsher, Jonathan. “Boccaccio's ‘Ars Moriendi’ in the Decameron.” *The Modern Language Review*, vol. 81, no. 3, 1986, pp. 621–632.\n\nGilman, Ernest B. “THE SUBJECT OF THE PLAGUE.” *Journal for Early Modern Cultural Studies*, vol. 10, no. 2, 2010, pp. 23–44.\n\nChiu, Remi. “MUSIC, PESTILENCE AND TWO SETTINGS OF O BEATE SEBASTIANE.” *Early Music History*, vol. 31, 2012, pp. 153–188.\n\nWatkins, Renee Neu. “Petrarch and the Black Death: From Fear to Monuments.” *Studies in the Renaissance*, vol. 19, 1972, pp. 196–223."
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72144o | why are there so few female geniuses? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/72144o/eli5why_are_there_so_few_female_geniuses/ | {
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"I think there are two big factors that contribute to this apparent imbalance:\n\n1. It takes a relatively long time for a scholar to be recognized as a genius - usually in regard to his/hers extraordinary work achievements, so the work has to be done first and so on.\n\n2. For a long time, women were not encouraged (or even were prohibited) to do research or other than simple work.\n\nIf you combine these two factors, it may explain why most of geniuses you know of (so historical and relatively recent) are male.\n\nThere might be other reasons, but I think these two are significant.",
"IQ tests are not a good way to determine genius. They are biased and ineffective when you test the extreme ends of the scale. There are many female geniuses.",
"Several studies have shown that although male and female IQs are equal in their statistical average, there is a wider standard deviation among males. Thus, men dominate both the top and the bottom of the intelligence spectrum, while women cluster close to the mean. So Einstein-level geniuses will be male, but, for example, so are all the dumbasses who post YouTube videos of themselves skateboarding off a roof."
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4zjlds | why does it take forever to become 20 and only a short time to be 40? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4zjlds/eli5_why_does_it_take_forever_to_become_20_and/ | {
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"time perception. At five years old, 1 year is a huge chunk of time (1/5th).Compared to life at 40 one year is 1/40th. A 5th of your life to date is now 8years. As you age, time seems to move faster because you have a larger pool of time to compare it to...."
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a7eu8v | why did we agree on rounding up if a value is 5 instead of rounding down? | PS: I would have loved to Name it „Eli10“ | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a7eu8v/eli5_why_did_we_agree_on_rounding_up_if_a_value/ | {
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"Because it splits the gap exactly in half:\n\n & #x200B;\n\n0,1,2,3,4 = Round Down (5 digits)\n\n5,6,7,8,9 = Round Up (5 digits)",
"I think it has something to do with how we count. \n\n0 1 2 3 4 | 5 6 7 8 9\n\nIts symetrical 5 on each side so 0 - 4 is round down, 5-9 is round up.\n\n",
"This isn’t exactly true. In food packaging if there is .5 grams they can round down. Lots of “fat free” and “sugar free” does this. ",
"We don't really agree on it. There are different ways of rounding something that ends in exactly 5. \"Bankers rounding\", for example, rounds exactly 5 in whichever direction make the digit before it come out to be even.\n\nThe common grade school way makes sense in that 0.50000000000001 needs to round up, so by having 0.50000000000000 also round up means that you only have to look at the first digit being rounded away, rather than all of the digits.\n\nBut technically this means you are rounding \"away from zero\", rather than \"up\", because -2.5 would go to -3 not to -2."
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1vs2et | why are foreign words in japanese written in odd letters? | Inside a string of Japanese letters, every now and then an English word, for example, pops up and is written in this oddly thin and disproportionate font in pretty much every font. Why is this a thing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vs2et/eli5_why_are_foreign_words_in_japanese_written_in/ | {
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"it's to make it more obvious that it's a word of foreign origin, so people dont get confused as easily. in some english books where there's occasional usage of other languages, those words are in *italics* instead. ",
"Japanese fonts are traditionally monospaced; that is, each character takes up the same space on the screen. Now, of course, `we have monospacing in English too`. But in the Latin alphabet, individual characters fit best in skinny rectangular boxes, while Japanese characters fit best in square boxes. So if you're using a Japanese font, you have to make Latin alphabet characters fill square boxes; that's going to look weird no matter how you do it.",
"Japanese has three scripts: 1. Kanji are ideographs, meaning you get a picture which represents an idea, like a picture of a tree to mean a tree.\n2. Hiragana are syllabic phonographs, meaning each character represents a syllable (ka, ki, ku etc). Hiragana are used for words which don't have kanji (or because you don't know the kanji) and or the grammatical bits of the language. So if you wrote \"I saw a tree\" the bit of the word which marks \"saw\" as past tense would be in hiragana.\n3. Katakana are similar in use to hiragana, but are used for foreign words and onomatopoeia. They're also sometimes used to write Japanese words but in a \"cool\" way, for example Honda is a Japanese word, but to show they're talking about the brand and not the name, which honda technically is, it's written in a way normally used to emphasise sounds.\nI hope I understood your question and that helps.\n\nEdit: I think you're asking about katakana.",
"Modern Japanese uses phonetic symols (hiragana) and a somewhat stylized set of chinese characters (kanji) for writing native Japanese words. While reading and writing in kanji is considered better by Japanese culture, the amount of memorization required means that children generally use hiragana at first and then transition to kanji as they grow, eventually only using hiragana for various Japanese particles. If you ever watch anime, you can sometimes tell if it is aimed at a younger audience by if you see tiny little symbols (hiragana pronounciation) written next to the more complicated ones (kanji) in song lyrics or on signs and books.\n\nKatakana was developed as a faster-to-write version of hiragana, but in more modern times it has been used to represent foreign words. If a Japanese person sees katakana, they know that it isn't just a written-out kanji, but is a word on its own. This helps prevent confusion as Japanese has very few sound combinations and therefore a lot of words with different meanings look alike when written phonetically. It also warns the Japanese speaker that it may contain some sound combinations which are a bit unusual, even in Japanese. If you hear a Japanese speaker read a passage which contains katakana, it's fairly easy to notice when they get to a katakana section because the words tend to not have the same rhythm as the native Japanese."
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f2r4bt | Were prisons in the US segregated? And if so, what was the transition period like? | If they were, what kind of issues arose during the desegregation of prisons? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/f2r4bt/were_prisons_in_the_us_segregated_and_if_so_what/ | {
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"I have an earlier answer that addresses legal versus de facto segregation in California prisons...specifically, [one very famous California prison](_URL_1_). I've highlighted some of the most relevant portions here:\n\n* [Has the percent of incarcerated people of color increased since Johnny Cash played at Folsom Prison or were only white men allowed to see him perform?](_URL_0_)\n\nAccording to Jim Marshall, **Cash's audience for his two January 1968 concerts included black, white, and Hispanic prisoners alike**. And Marshall should know--he's the guy who [took the photographs](_URL_2_) demonstrating [exactly that!](_URL_3_)\n\nBlack Americans have been incarcerated at rate disproportionate to population demographics since--surprise, surprise--white people killed Reconstruction. This has been as true in California as anywhere else, and perhaps insidiously so given the state's generally liberal reputation. And Folsom Prison had its part to play. In 1940, California's population was 1.8% black but the population of inmates at San Quentin 9%; Folsom, recently reorganized into the state's maximum security prison, had a black population of 12%. As more and more black Americans sought safety and success in California over the decades of the Great Migration, the black prison population swelled. By 1960, black people comprised 5.6% of California's population and *22%* of new prison inmates overall.\n\nSo what gives with the photo?\n\n**Like most prisons, Folsom had a long history of internally segregating prisoners where it could. And as testimony after testimony reflected, into the 1960s this was an explicitly and purposefully racist move.** In 1943, a black man incarcerated at Folsom wrote to a committee sponsored by the governor:\n\n > Our servitude here is limited to inferior work. The only work that is given to Negroes is such as porter work, digging in the ground and breaking rock or what ever else the white inmates don’t want to do.\n\nTo be clear, Mills was only describing the few white men who were also forced to labor in the quarry alongside the black prisoners--most whites had better jobs altogether, including some that took them outside prison walls. (The quarry was later closed when outside groups and labor unions protested that it was taking their jobs). It's no wonder that black intellectuals like Angela Davis and Eldridge Cleaver (himself incarcerated at Folsom) depicted the American prison system as the new plantation slavery.\n\nThe situation wasn't any better either away from labor in Mills' day or during the 1950s and 60s, either. Black prisoners were routinely shunted to overcrowded cells on Folsom's top floors, suffering the worst in midsummer sweltering heat and always called last for recreation and meals. In 1959, a lawsuit brought against Folsom by a black inmate claimed that this was an ongoing problem, along with other officially imposed efforts at segregation.\n\nEthan Blue, meanwhile, highlights the **de facto social segregation** imposed by inmates on themselves even in common spaces:\n\n > **There was plenty of [cross-racial collaboration and antagonism in the prison yard]**, when black,\nwhite, Asian, and Mexican prisoners gambled, traded, joked around, and even loved each other...Nevertheless,\n**racial segregation became the norm in San Quentin and Folsom. White prisoners enforced racial spaces to delineate privilege and hierarchy...Black prisoners could be booed (or worse) if they tried to sit and eat in the “white” section of the dining hall.**\n\nMusic, so racially politicized outside prison walls, became another focus for both crossing racial lines and policing them. Prison radio stations' variety shows happily broadcast performances by \"in-house bands\" like the (black) Hot Jivers and the (white) Rhythmic Stringsters, and individual performers might even cross racial lines to perform together. But when shows' hosts picked inmates to interview, they universally selected guests who \"sounded white,\" and often used racially-coded descriptors like \"freckled\" and \"ruddy\" to affirm the audio's stereotypical assumption. And eagerly-anticipated drag shows and other annual events wouldn't be complete without a good dose of white prisoners in blackface.\n\nSo there were good reasons both for inmates of all races to attend Cash's concerts at Folsom in 1968, and for white inmates to try to muscle out black and Hispanic prisoners. Nevertheless, Johnny Cash was able and eager to close his shows with a song written by a white inmate, and shake hands with black and Hispanic inmates in the prison yard afterwards. But I mean--this is a man who prefaced a performance of *Battle Hymn of the Republic* (\"As [Christ] died to make men holy / let us die to make men free\") with remarks about how the song brought together a cleft country as soldiers and mothers on both sides could sing it. Whatever his own or prison racial politics, he at least wanted his music to bring people together.",
"Hello. While we have been provided with a tremendous response from u/sunagainstgold, I would like to approach it from my point. I am not a flaired historian here, but I am a US legal historian and professor who is writing a book on the reform of prisons in Arkansas by the federal courts. \n\nBrown v. Board of Education (1954) didn't mean an end to \"separate but equal\" everywhere, as it only applied to public schooling. It certainly didn't penetrate Southern prison farms, which are at the center of my research. I am writing about a federal judge, J. Smith Henley, from Arkansas, who, in the early 1960s, decided it was time to begin reforming state prisons. One of the topics prisoners complained of was discrimination. Now, one has to understand that prison farms at the time were run by \"trusty\" guards. These were actual prisoners that served as guards! And this was going on for as long as these prison farms had been opened. Therefore, the discrimination that was imposed in Southern prison farms was most likely instituted by prisoners with a nod of the head from the few free-world (not serving time) workers. This discrimination definitely included segregation, albeit a more sophisticated version of segregation that might have extended past race. \n\nIn the world of Southern prison farms, segregation did exist. The transition period after the courts' declaration of the practice illegal is as tragic as the segregation itself. What made it worse was that ending segregation was one of many changes these states were instituting in their prison farms. \n\nI'd love to say more, but I don't want to put too much effort into something and realize at this late hour, I am violating a rule of the sub. I also know so much about this topic that I'd want to talk about it for hours. And finally, while I know they aren't \"required,\" I would point you to my own writing on the subject rather than my intense footnotes. Feel free to ask me about any sources, primary and secondary, and I'll gladly share."
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6nzbfz | If bloodletting was rubbish, why was it considered as a medical procedure for such a long time? | bloodletting was used from the early Greek civilization up to the 19th century, why didn't someone notice it had no positive effect? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6nzbfz/if_bloodletting_was_rubbish_why_was_it_considered/ | {
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"I am not a historian, but rather a doctor who runs a podcast about medical history. Hopefully someone with a lot more experience in history of medicine will go into depth on Galen, the four humors, and the birth of scientific medicine. I actually want to address the second part of your question, and talk about the first actual clinical trial of bloodletting (therapeutic phlebotomy), and it was lost for almost 175 years. Alexander Lesassier Hamilton was a British military surgeon during the Peninsular War. He served with two other surgeons, and sometime during 1816, he decided to perform a clinical trial for his MD thesis. He was inspired by James Lind's famous scurvy trial, and actually included randomization of a sort. He and his colleagues treated 366 soldiers, and randomized by rotation each patient to one of the three surgeons. Lesassier Hamilton and a Mr. Anderson (surgeons would be called Mr. after completing their medical training, still done today in the UK) did not use bloodletting; the third surgeon did. I will just quote his conclusion here, because it's quite remarkable:\n\n > It had been so arranged, that this number was\n > admitted, alternately, in such a manner that each of\n > us had one third of the whole. The sick were indiscriminately\n > received, and were attended as nearly as\n > possible with the same care and accommodated with\n > the same comforts. One third of the whole were soldiers\n > of the 61st Regiment, the remainder of my own\n > (the 42nd) Regiment. Neither Mr Anderson nor\n > I ever once employed the lancet. He lost two, I four\n > cases; whilst out of the other third [treated with\n > bloodletting by the third surgeon] thirty five patients\n > died.\n\nJust some back of the envelope calculations puts the number needed to harm (or really number needed to kill) at 4. That is, for every four patients treated with therapeutic phlebotomy, one would die. These days, in medicine we get excited about treatment effects with an NNT of 60 (by example the NNT to prevent a non-fatal stroke in a daily aspiring in 10,000 patients -- 10,000 people need to be given a daily aspirin for a year to prevent one non-fatal stroke).\n\nWhat I find really interesting is that these papers, rather than being published, were locked up in a trunk until 1987, and apparently had very little impact on medical practice in the nineteenth century, if they were known at all. \n\nThe first widely-disseminated study that cast suspicion on bloodletting was from French physician Pierre Louis in 1828. He examined case records (he is known by some as the father of epidemiology, and did much to establish the field). He selected 77 patients who had been diagnosed with pneumonia, and then analyzed them as part of several groups -- notably, one being bled early (1-4 days after onset), and the other late (5-9). The two groups had roughly the same age (the Table 1 that doctors get so excited about in RCTs). His conclusion was that early bleeding led to a shorter duration of illness -- but a markedly higher mortality (44%, compared to 25% in the late group). He attempted to control for other factors, but the difference still remained. His ultimate conclusion was that bloodletting might have some useful effects in certain conditions, but far fewer than was previously thought. \n\nAfter this, modern epidemiology, biostatistics, and our knowledge of physiology caught of with the practice of bloodletting. In 1855, Bennett confirmed Louis's findings, showing with statistics that declining phlebotomy led to increased survival in pneumonia. In the 1860s, Koch and Pasteur developed germ theory, and gave a pathophysiological explanation for the \"inflammation\" that phlebotomy was supposed to treat. The indications for phlebotomy narrowed -- but I should still note it was used in its traditional sense will into the 20th century. To quote from the Parapia article I have below:\n\n > The first edition of ‘The Principles and Practice of Medicine’ published in 1952 states that venesection is indicated whenever pulmonary congestion or venous engorgement is extreme and other measures are ineffective\n\nAnd therapeutic phlebotomy is STILL used today! It is an evidence-based treatment for polycythemia vera (where the body makes too many red blood cells), hemochromotosis (a genetic defect leads to iron overload; through phlebotomy people can lead normal lives), and porpyhria, not to mention for testing and for blood donation.\n\nOkay, that turned out more than I thought -- I might actually use some of this for the podcast. Let me know if you have any other questions!\n\n**Sources**\n\n* Morabia A, Pierre-Charles-Alexandre Louis and the evaluation of bloodletting, J R Soc Med. 2006 Mar; 99(3): 158–160.\n* Milne I and Chalmers I, Alexander Lesassier Hamilton’s 1816 report of a controlled trial of bloodletting. J Royal Soc Med. February 26, 2015\n* Greenstone G, The history of bloodletting. BCMJ, Vol. 52, No. 1, January, February 2010, page(s) 12-14\tPremise\n* Parapia L, History of bloodletting by phlebotomy. BJH. (_URL_1_)\n\nEDIT: As suggested! Thanks\n\nI've gotten several messages, and as this is my public account as opposed to my private one, I don't mind any identification. The podcast is Bedside Rounds and you can find it in any of these fine purveyors of podcastery: [Apple Podcasts](_URL_0_) | [Stitcher](_URL_3_) | [Website](_URL_2_)\n\nEDIT 2: Finally read what I wrote and fixed some egregious typos. Also took out the part about Austin Flint -- I hadn't had my AM coffee yet; Austin Flint's big contribution is the development of the placebo.\n\n",
"If I could ask, I had heard that bleeding (obviously) lowered blood pressure (in a dangerous way) and this seemed to treat many common symptoms, implying to pre-contrmporary doctors its viability as a treatment? Could anyone fill me in as to what phlebotomy actually does to the body that might have suggested it works?"
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1mhxvv | Trying to help a friend study science and for all my searching, I can't answer this: Why do atoms become isotopes? | I know "they gain or lose neutrons," but why? What has to happen to make that happen? | askscience | http://www.reddit.com/r/askscience/comments/1mhxvv/trying_to_help_a_friend_study_science_and_for_all/ | {
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"What do you mean become isotopes? Any given combinations of protons and neutrons in a nucleus is an isotope.",
"You might want to look up decay tables. It can happen that an unstable nucleus decays into another one, for example the decay of [Nitrogen14 to Carbon14](_URL_0_), which then in turn is not the stable configuration but has a relevant half life time.\n\nAlso there is [Neutron capture](_URL_1_).",
"Every atom is an isotope of some element, as others have pointed out here. It's just that for most of them, there's one isotope that's more common than the others, and we tend to think of that one as the \"real\" element, and the others as \"just isotopes\". Take carbon-12, the most common, and carbon-13, which is a bit over 1%, for example.\n\nBut there other other elements, like bromine, that are found pretty much 50/50 between two isotopes. And tin has perhaps the widest profile of all the common elements, with ten stable isotopes.\n\nIsotopes get formed by the decay of a radioactive nucleus, or by a nucleus absorbing a neutron (or alpha particle) from something else radioactive. The distribution of isotopes we find for a given element reflects whether or not they're stable to decay themselves, and how easy and/or likely the nuclear processes to produce them are."
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jrbde | universal healthcare? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jrbde/eli5_universal_healthcare/ | {
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"In the UK we have Universal Healthcare. This means that if you get sick, or are in an accident, you are taken to hospital, given all the care you need for as long as you need it, and are let go when you are fit to leave.\n\nYou do not pay for this service. The only thing I have ever paid for on the NHS are prescriptions (Flat fee of something like £7), and orthodontics (cosmetic dentistry).\n\nThis is paid for my National Insurance contributions which are deducted automatically from your paycheck.\n\nEverybody is entitled to the same level of care. It does not matter how rich you are, when you're in an NHS hospital you are treated the same as everyone else.",
"In the UK we have Universal Healthcare. This means that if you get sick, or are in an accident, you are taken to hospital, given all the care you need for as long as you need it, and are let go when you are fit to leave.\n\nYou do not pay for this service. The only thing I have ever paid for on the NHS are prescriptions (Flat fee of something like £7), and orthodontics (cosmetic dentistry).\n\nThis is paid for my National Insurance contributions which are deducted automatically from your paycheck.\n\nEverybody is entitled to the same level of care. It does not matter how rich you are, when you're in an NHS hospital you are treated the same as everyone else."
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8bphie | Why is voltage and current specified in electrical equipments? | My phone charger, for example, has an output of 1.55A at 5V. My understanding is that Voltage causes current to flow. Current is the rate of flow.
So in the case of my charger, does the voltage here matter? Why is it specified? To calculate power? What if I have another charger that's 1.55A at 10V? What does that mean? Surely, my phone isn't getting charged faster because they're both 1.55 coloumbs of charge per second. | askscience | https://www.reddit.com/r/askscience/comments/8bphie/why_is_voltage_and_current_specified_in/ | {
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"Those specifications are most likely there so you know what should be going into and coming out of your device. They might also be a regulatory requirement, but I’m not 100% positive.\n\nThe current output on the label specifies the maximum current a device connected to it can draw. Charging a device with a higher current output could potentially allow it to charge faster, but the specifications of the device also matter here. If my phone charges at 5 volts and a maximum of 1 amp, and I connect a 5 volt 0.5 amp charger, my phone will charge in about twice the time that a 5 volt 1 amp charger would take to fully charge the device. The charger is not going to be able to give my phone more current than it’s rated for. But if I connect my phone to a 5 volt 2 amp charger, my phone will probably not charge any faster, because regardless of how much current the charger can output at a maximum, my phone will only draw a maximum of 1 amp from it.\n\nThis is why my iPhone charges faster when I use a charger meant for a tablet; the iPhone charger and the tablet charger are both able to output a current my phone can handle, however the iPhone charger has a lower maximum current than the iPad charger. \n\nIncreasing/decreasing the voltage, on the other hand, will most likely not do anything beneficial. Modern devices are designed to charge at a specific input voltage, so you don’t want to give your device anything different. \n\nHope this helps!\n\nEdit: Double and half are definitely not the same thing haha. Sorry if that caused confusion!",
"The charger is rated for a certain voltage and amperage, but when you're charging your phone the charger just supplies the voltage and the phone regulates the current, up to the maximum the charger can output. The voltage does matter though because the phone is expecting a certain voltage to come in. 5V is standard, but some phones with their own brand of fast charging will support different voltages. If you used a charger rated at 10V/1.55A, which you wouldn't because it's not in the specs for anything, you would probably damage your phone unless that was some special mode your phone supported.",
" > they're both 1.55 coloumbs of charge per second.\n\nThat's not right. 1.55 C at 5 V won't charge your phone as fast as 1.55 C at 10 V. The phone is designed for a certain voltage, but let's assume your phone can use a wide range of voltages to charge the battery. In terms of energy, the amount of charge is Amps\\*Volts\\*time. Since Amps are Coulombs/second, energy in joules is Coulombs*Volts. \n\nThe current rating is just the maximum it can supply. Most power supplies are constant voltage. Constant current supplies exist for driving LEDs and other things, but they are far less common. "
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198tgz | why do download speeds waver so much in the beginning, and then stabilize after a while? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/198tgz/why_do_download_speeds_waver_so_much_in_the/ | {
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"It's called \"Windowing\" and load balancing it works like this.\n\nWhen data is transmitted over a network as massive as the Internet it could be passing through a dozen or so different routers with different capabilities about them. There are many different paths these routers may choose to route your data and it's quite possible that the complete path taken will vary as the file downloads. In the beginning a small chunk of the file is sent from the server to your computer, and your computer yells back to the server \"I got all of that first batch, send the next batch please!\" And the server sends another batch but perhaps twice as much data bundled together at once. The computer yells back, \"Got it, next batch please!\" This continues until at some point not quite all of the intended batch gets there and the computer yells back, \"I'm missing the last little bit, can you resend that?\" The server then says to itself, \"Hmmm, I guess somewhere along the way there's a router that can't handle batches any larger than X, so I'm going to reduce the size of the batches to a smaller number and continue gradually experimenting with the size until I find an optimal size.\" This is called windowing.\n\nNow lets say along the way one of the routers between you and the server goes offline. A few things will happen. Nearby routers that were connected to the dead router will notice it's silent and will then communicate with each other to confirm that others all see that the router is silent and then update their routing tables to create a work around path. This work around path might consist of slower equipment that's secondary or a few hops out of the way, which might result in a smaller \"window\" for which the server has to adapt for when sending batches of packets. The router wouldn't necessarily need to go down either, it could also become overloaded with high traffic that results in noticible delays or a reduction in the number of packets per batch in an effort to keep everything moving, albeit a little more slowly, and the routers automatically determine a work around path that, for that busy period of time, is used alternatively. This is called load balancing."
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ypp8p | why do i sometimes get that it feels like its itching inside my hand, foot etc.. | Sometimes its starts to itch on my hand for example, and start to itch on the spot but it doesnt work, I itch over the whole hand, but i doesnt help, Its like **inside** the hand. Happens sometimes to the foot, face, and legs.
EDIT: Sorry for my grammar, im.. 5
EDIT: Scratching. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ypp8p/why_do_i_sometimes_get_that_it_feels_like_its/ | {
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"Don't worry. There are probably just some insects inside you.",
"An itch is actually similar to pain. It's simply nerve endings reacting to some stimulus. When it itches inside, that just means the nerve endings that are reacting to the itch is beneath the skin.",
"It's possibly related to complex motor tics. These are issues when your brain needs or feels a want for a certain or strange stimulation. Try to ignore it and when you can't, just do what you can to stimulate it, like stretching lightly.",
"I get this feeling inside my chest as well sometimes. Still don't know why.",
"I have chronic bronchitis, asthma and allergies. My lungs itch so much it freaks me out when they don't. It just the inflammation activating the nerves. It's not really an itch like on your skin, but your brain interprets it that way.",
"WebMD says you have cancer.",
"Instead of itching it, you should scratch it.",
"I have a liver diease that makes me super itchy... Liver ooze gets into my blood stream and pokes my vessels... Making me itchy everywhere, below the skin... Now go to bed its past your bed time little one",
"Reading this post made me itchy. Thank you. :-/\n",
"This used to happen to me often as a kid",
"In my culture it means you need to take your ass to the casino because you're about to make some money",
"Wash your hands after you go number 3.",
"I get this in the palm of my hand all the time!",
"Google sensory processing disorder or sensory integration dysfunction. I've been dealing with it my whole life and just started therapy a few years ago which makes a world of difference. ",
"I get this feeling a few times a month, same places too: face, legs, feet and especially hands (and very occasionally a few centimeters into the abdomen). It's always about a half a centimeter under the skin (other than the abdomen ones). I have no idea what causes it, I think it's just like a really small twitch that my brain interprets as an itch. They only go away by either pushing my thumbnail or teeth into it.",
"Sometimes our nerves are not precise. For example, if you have sore hands or fingers, rub your forearms. \n\nSo try rubbing further up the limb that is itching. It might work. \n\nI have a spot on my ribs where if I rub it, I can feel it on the inside of my arm, between the elbow and elbow-pit. If I put my arm against my side, the two spots touch. However, If I rub that spot on my arm, I cannot feel it on my ribs. ",
"Probably just your Anterior cingulate cortex acting up.",
"my gramama says whenever the right hand itches, means i'm gonna get money soon..!"
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1zet5x | Cleaning out things from my late grandfather's garage my mother found what seems to be an old Japanese flashlight he brought home from WWII. Was wondering if anyone knew a little more about it | [This](_URL_0_) is the flashlight that was found; it was found in a box with post cards and other documents about his ship, so we assume that is from the war. The outer case of the flashlight is made of wood and it had two large batteries (sitting on either side of the flashlight) with Japanese writing. I'm sorry I don't have any other photos, I wasn't there with them when they found it, but hopefully I can get back to their house soon to get a better picture or two, I came here to see if maybe someone can shed a little light on what we have found (no pun intended) | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1zet5x/cleaning_out_things_from_my_late_grandfathers/ | {
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"That's a neat photo. This appears to be one of the flashlights Panasonic was marketing during the war under the brand name National. It's likely made of wood because metal was needed for the war effort. [Here's](_URL_0_) a photo of a similar wooden flashlight from the Panasonic Museum in Tokyo. Perhaps others will have more on this, but that's the best I can do."
]
} | [] | [
"http://imgur.com/HWfmL5l"
] | [
[
"http://panasonic.net/history/museum/product/product02.html"
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|
crlyqp | what is the determining factor between assault with a deadly weapon and attempted murder? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/crlyqp/eli5_what_is_the_determining_factor_between/ | {
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"No, the difference is intent. If you intended to kill them then its attempted murder. If you didnt want to kill them but just hurt or scare them, but you used a weapon that is deadly to do that, then its assault with a deadly weapon."
]
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[]
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||
1yjvlf | what is a meshnet? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1yjvlf/eli5_what_is_a_meshnet/ | {
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"Meshnet is a peer to peer internet system. It makes each internet device that is able to transmit and receive data a mini internet server. and by mini internet server I specifically mean setting aside part of its available usage to transmit and pass along data. This works because each router in the network is connected to each other network capable device.\n\nSo instead of your internet working like this\n\nYour computer > ISP > \"Local network\" > \"High level network\"\n\n\nWith meshnet made of routers would look like this\n\nYour computer > your wifi router > Next door neighbor's wifi router > Guy's down the street wifi router > person's half way across town wifi router > Server where data is located\n\n\nBut meshnet doesn't have to only be made of routers. It can be made with ANY device that is capable of transmitting and receiving data."
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||
8rlzed | If you charge your phone, or laptop, or anything, does it weight more than if it is dead? | askscience | https://www.reddit.com/r/askscience/comments/8rlzed/if_you_charge_your_phone_or_laptop_or_anything/ | {
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"Surprisingly yes it does, there’s no extra matter present but there is more energy in a charged battery. Gravity acts on both mass and energy so the laptop or phone will have a greater force exerted upon it resulting in it weighing more if you put it on a scale (although I doubt a conventional kitchen scale could detect the minute difference) ",
"No, charging just moves where the ions in the battery are, like moving water backwards through a dam to store power for later use. You're not adding water, just moving it from an area of lower concentration to higher."
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b7ibvy | Is the ability to recall something from memory effected by how awake you were when you learned it? | If I am studying and it is late at night and I’m tired, when I am fully rested how will my ability to remember what I was learning be effected.
I work shifts and often do study for a few hours between 10pm and 1am. I was wondering if this is a poor way of learning. | askscience | https://www.reddit.com/r/askscience/comments/b7ibvy/is_the_ability_to_recall_something_from_memory/ | {
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"text": [
"I’m no expert, but things learned before going to sleep are typically remembered better because they are immune from interference. On the other hand, when you are tired and inattentive to the information then it might not be encoded into long-term memory at all. Optimally, you should be alert and thinking semantically about the information.",
"Two social psychological concepts come to mind here.\nState dependent memory encoding and Erickson Arousal theory of learning. State dependent learning states that what ever state of mind you are in during encoding is the state of mind where recall would be optimal. Erickson arousal theory states that learning is most optimal in a medium arousal state where you are not too comfortable or too stressed. Extrapolating from these two my guess would be that learning at night in a tired state of mind is optimal for a middle arousal and probably optimal for most recall. Especially if you are tired all of the time like myself lol. "
]
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[],
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2lckqh | why isn't washington d.c. a state? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2lckqh/eli5_why_isnt_washington_dc_a_state/ | {
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"DC is not constitutionally permitted to be a state. The whole point of cutting off an area 10 miles square for the capital was so it would not reside within the boundaries of any state.",
"It is not allowed to become one. It is specifically set aside to be the capitol city so that no State can have more power by housing the capital. "
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2i79gv | what powers pump-jack oil wells? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2i79gv/eli5_what_powers_pumpjack_oil_wells/ | {
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"Most of the ones I've seen use an electric motor, but any type of engine would work.",
"1) Electricity (sometimes derived from solar panels)\n2) Natural gas (Methane is the big one)\n3) Propane\n4) Diesel (not very common)\n5) The tears of environmentalists"
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1dk6jf | How did we end up with James VI and I as King of both Scotland and England? | I'm trying to learn about the history of the Scottish Monarchy but I can't get my head around this. All throughout what I'm reading, the Scottish hate the English while the English kings are trying to claim ownership over Scotland. Robert the Bruce dies, his son dies, then the Stewarts come along. Then I get confused. I can't seem to find where we end up one cousin away from from the English, in Elizabeth I. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1dk6jf/how_did_we_end_up_with_james_vi_and_i_as_king_of/ | {
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"James's mother was Queen Mary of the Scots, who had Tudor lineage from Henry VIII's sister, Margaret. When Elizabeth died, James was seen as next in line due to his Tudor heritage. Robert Cecil, the Principal Minister, had made sure that the succession would go over smoothly and had been corresponding with him for months before she died. \n\nHowever, this originated with James IV to Margaret Tudor, daughter of Henry VII. It's purpose to stop the Anglo-Scottish war, which it didn't as James IV later invaded northern England. \n\n[Here's the proclamation of 1604](_URL_0_)\n\nLet me get back to you on sources if you need reading material as well.",
"[Here's the genealogy of the Scottish monarchs](_URL_0_), from the British royal family's website. As you can see near the bottom right of the PDF page, King James IV of Scotland had married Margaret daughter of King Henry VII of England as part of the negotiations for a peace treaty. (The treaty didn't hold, incidentally. James IV would become the last monarch in the British Isles to be killed in battle, while fighting his brother-in-law.)\n\nSo, once Queen Elizabeth died without issue, her closest relative happened to be James VI of Scotland, great-grandson of Margaret. There had definitely been enmities between England and Scotland, but those were irrelevant to the legal principles of primogeniture."
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34m92s | why tesla's new power wall a big deal. | How is Tesla's new battery pack much different from what I can get today? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/34m92s/eli5_why_teslas_new_power_wall_a_big_deal/ | {
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"It is mass produced and much more effective than current battery options, which usually rely on lead acid. Tesla has made a massive lithium battery factory.",
"it's a big deal because of mass production of lithium ion packs directed at consumer. \n\nresidential battery packs is not a new thing. (although mainly backyard tinkerers)\ncommercial battery power installation is not a new thing. (although using lead acids for cost)\nlithium ion battery packs is not new thing. (that's what powers your cell phone and laptop)\n\n\ncombining all 3 and scaling for mass production is a new thing.\n",
"For people with solar panels, it lets them store the excess energy and use it themselves rather than selling it back to the grid for pennies.\n\nFor everyone with variable usage costs, it lets you take power from the grid when it is cheapest (nightime) and then store it to use at any time you want basically meaning you always pay the minimum rate for your power.\n\nFor everyone long term, if these gets widely adopted, power companies can completely change the way they create power, and there will never be variable rates. And \"theoretically/optimistically\" power would get cheaper because power plants would be running constantly rather than stopping and starting.\n\nTelsas power banks are better than what you can get today simply because they are for the most part a lot cheaper than current methods, and have programming built in so anybody can use them efficiently.",
"Not an answer, but honest question regarding Elon. I feel at times I'm not really comprehending all that he is doing or is trying to do for this world. I feel I should look at him as a great inventor, entrepreneur, but I don't know how he stacks up historically. \n\nAnyone have a good explanation on this at all? I'm impressed by him either way. ",
"Someone compared this to the iPhone. When it came out (~~2005~~ 2007), all the tech in it was nothing new, but it was packaged in an elegant way that just worked. However, mass production of lithium in this scale is new.",
"Solar panels are useless anyway. There's always a dense sheet of grey clouds blocking out the sun.\n\n... You guys have that outside of Britain as well, right?",
"Something that hasn't really been elaborated on, but is the \"main\" reason that the Power Wall is a big deal imo, is that it really is the missing link that will enable your average consumer to produce, store, and use power for their home. Once this technology is up and running, in theory, all manner of home-generated power, whether it be from a wind turbine, a solar array, or hell a mini hydro plant in your back yard, will suddenly become much more useful and will make going \"off grid\" a breeze, if you've got the ... well ... breeze to pull it off.\n\nI believe easily being able to store your own home-produced energy will lead to a flood of innovation and interest in creating green, renewable energy at home, because that energy suddenly becomes tangible and real, not just a way to reduce your power bill. Power you can USE, in your home, without having to be an electrician. ",
"**To answer the question:** It isn't different at all from what you can get today. \n\nHere's a database with existing energy storage systems in german including various LiB systems. As you can see there are already dozens of existing systems from different companies. [Link in German](_URL_0_)\n\nVarious research companies predict that the gigafactory will see a lot of overcapacity. So how does Tesla solve this problem? They advertise their batteries for the homestorage market that will become very important in the next years. [Link to report](_URL_1_)\n\nTesla made a huge gamble with the Gigafactory (The planned production exceeds the global production of lithium cells in 2013). In order to succeed they now have to find enough buyers for their cells. Whether these cells are used in cars or storage systems doesn't matter.",
"One of the big features for remote areas of developing countries is it can eliminate the necessity of the grid. Generate (renewable sources) and store power where it is needed rather than in a fossil fuel plant miles away and transported across expensive power lines.",
"It is also useful to have such a battery pack in the case of brownouts or powershedding. It helps even out demand on the system.\n\nThe reason Tesla's battery pack is a big deal is, unlike current lead-acid UPSes, these are compact and designed in such a way as to not cause too much hassle with them being in a home environment.",
"Solar installations are usually grid tied, but this isn't a big deal to allow someone to be \"off-grid\". We already had crappy batteries for that, but it worked. It has little to do with reselling the electrons your panels generated.\n\n**It's an adoption solution that fixes another major issue, allowing near-100% solar.**\n\nElectric substations are generally one-way. It converts the high voltage to 220 for the neighborhood to use, but cannot backfeed excess 220 to the high voltage lines. That means if everyone in the neighborhood had solar, the grid would be saturated and the voltage would go way too high on a sunny day. Good batteries allow you to store the excess to be used later at night, without having to upgrade the grid unless there was a ton of excess panels. Without a storage solution, if too many people have solar near you, you will not be allowed to install it to prevent destabilizing the voltage \n\nThis is a big deal because it's provides much better batteries, which last much longer, don't potentially leak flammable gasses and acids, and look sexy. By being more accessible it handles an adoption problem, and people will be more likely to use them. People don't want their houses to look like the back of a hippie's school bus. It's the difference between an iPhone and an old brick cellphone.",
"Something missing from these comments is that on the grid, the power that is generated for your light bulb is created right that instant. So power companies have to guess what the max output of, say, any city and make sure they're well above, so that there won't be an outage. On a large scale, these batteries are a good way way to store excess energy, therefore creating a more efficient system where excess energy isn't wasted.",
"It's the missing link. We have solar panels that produce more power than you need during the day so there's power going to waste. Then no power during the night (if you'd be relying 100% on solar that is). Now you can store that extra energy harnessed during the day and use it during the night.",
"A lot of people are making excellent point. But I'm not sure I've seen it mentioned, a lot of renewable energy doesn't have a consistent output. Solar is strong during the day, less so at night. Wind is great but depends on, well, the wind. The power grid is extremely fragile, and can't really deal well with a variable source of energy as well as variable usage of it. And the largest issue with it has been how to store the power it makes to be used when and how it's needed. What Tesla is doing is great for a couple reasons. It's good for the consumer that has a small renewable source, so they can use more of what they create when it's needed. But it's even better for business. Businesses use much more power than homes, and are in a position to make more efficient use of the batteries. Also, it's possible that with more efficient solar (for example) and more efficient batteries, that we could get to a place where each small community is providing its own power needs with small solar farms, in much the way that some areas have an electric co-op now.",
"Imagine every citizen is streaming youtube online, only no one is allowed to buffer their feed. Either the infrastructure has to be beefy as fuck to prevent video from constantly stopping and starting due to the variable usage of all citizens OR you create a way to buffer the video so that the system has a way to cope with variable demand. The Tesla wall batteries are the buffering mechanism for power.",
"Ok I think I got this - a lot of commenters are glossing over the 'why' and jumping into how - yes they're big batteries. yes they hold juice so your home can use it. Tesla's proposal is a big deal because of the problem exhibited in this chart: _URL_0_ - those peak times cause power companies to run generators in overdrive, buy power from other companies and have brown-outs. If the peak load can be shifted away from the power companies and onto individual homes the grid's requirements for output become much more normalized. Reducing peak load events will drive down costs and potentially emissions on the current setup. Adding solar, wind and hydro resources will further drive down emissions, those models do NOT do well in peak scenarios.\n\ntl;dr (of an eli5 heh) stabilize the demand put on the traditional power grid - > open opportunities for more eco-friendly power.",
"Will these be able to connect easily into a grid-tied solar system? See what I mean below: \n\nRight now my utility makes you choose one or the other if you go solar:\n\n* A grid-tied system with no batteries, or\n* A solar system with batteries completely disconnected from the grid.\n\nThe reason for this is that they don't want the batteries feeding back into the grid. Imagine if a service worker from the utility turn off the power to work on it, but gets zapped because a house had batteries that were energizing the line from the other end.\n\nFor a client's project we managed to get a combo system approved, but only by essentially breaking it into 2 pieces to keep the batteries isolated. Then we had a very expensive piece of equipment to get them to work together.\n\nThis would be a big deal if the safety was built into these Teslas so that they isolate the power from the grid if the grid goes down.",
"We have basically this exact thing at work and have done for ages. It isn't a big deal because it is a product that has been available for ages. ",
"You know when you switch on your light? Or any time you use electrcity? It's all being created, essentially real time. Moving more of the power grid to a system that can store energy rather than one that has to create it on demand makes the system capable of being run more efficiently.\n\nAs a side benefit, it means people with these batteries have a backup solution in case power goes out for an extended time, which is more likely in an environment of global warming. But, the more practical day-to-day application is that it means you pull power off the grid when its cheaper and store it for when you want to use it, rather than be one of those people paying top rate when everyone is running their A/C when it's a 100 degrees F outside.",
"One of the bigger implications, yet sort of unlikely in my opinion, is that it can be easily installed in third world countries and power places that have little to no power infrastructure, similar to jumping the landline technology with cell phones as Elon stated. The problem is that solar panels are very expensive, so the governments of these countries would have to pay for installation and maintenance of solar panels and the Powerwalls. Unlikely any time soon, but the technology will be readily available, which is something new.\n\nI guess a good way to explain it is imagine if you could get internet as fast as Google Fiber with no wires/cords/infrastructure. It would change the market completely. However, Powerwall still has a few downsides.",
"Ive seen several accounts of the \"savings\", it seems pretty thin. Some states (such as california) apparently have ungodly high electric rates, and they have huge variances for peak vs off-peak. This can help reduce that spike load on the utilities, and help the homeowner save money by avoiding the expensive part of the day.\n\nIn the end, it is \"wasting\" energy, in that your probably losing 20% to waste, but thats an acceptible loss for the benefit. If you live in the right place.\n\nPersonally, my power is the same price 24hrs a day. so it would do nothing for me. (my provider might appreciate it, but not enough to compensate me)",
"What if i charged the battery during off peak hours through the grid and used it during the day when rates were higher? Doesn't this become applicable even without solar panels?",
"answer:\nhe talked about how cell phones leap-frogged land lines in some developing countries. there is no need to build land line infrastructure because cell phones are cheaper and better. \nsame with this battery pack. homes that are not on a power grid/ unreliable power grid can leap-frog infrastructure and have their own reliable power source.",
"It's a very low price point for the tech, lithium batteries are much higher energy density than the still widely used lead acid packs for the same job. The price point is still very high on lithium cells and Tesla at least halved what a good estimate of cost should be. Nobody knows their exact reasoning but it would be a defensible opinion to say that these are sold at a loss. \n\nThis has to come about if home solar is going to do actually make a difference in our total power usage. Currently most home solar users don't store, they pump power back into the grid and their meter spins backwards. This is not something a power company wants to happen on a large scale because they needs your fees to maintain the lines, it's foreseeable that in the near future if solar is popular this practice will not be allowed and users should be storing their power and using it when they need it to get any benefit. ",
"God so much hype around that announcement. The very cynical side of me is wondering how many of these requests, news stories, etc are astroturfing and shilling by marketing companies. \n\nSay that you have a solar home. During the day you will often get enough energy to power your house with some left over. What do you do with the excess? If you're still on the grid you might feed it back into the mains which is effectively turning your meter back or selling your excess to the power grid. \n\nBut maybe you're not on the grid, or if you are maybe you don't want to put it into the grid, maybe you want to store it for use overnight instead of switching to grid after dark. How do you store that energy? \n\n\nPrior to Musk's announcement you did it in one of 2 ways. \n\n1. You bought a bunch of deep cycle or marine batteries, got a bunch of jumper bars and connected them all together along with an inverter, battery charge controller, safety fuses, and you left it in a big ugly lump of batteries somewhere in your house or garage. \n\n2. You got out a soldering iron and your visa card and bought hundreds of hobby grade Lipo/LiFe/LiIon battery packs and soldered them together in blocks of series, and blocks of parallel until you arrived at the operating voltage of your solar panels minus several volts for charging current. You also had to add a charging controller, safety fuses, etc. If you wanted to do it right you built a large jig and an enclosure to hold the hundreds of small batteries all wired together, and it was still an eyesore. \n\n\nAfter Musk's announcement. \n\nYou shell out 3,000 bucks, grab a screwdriver and attach the shiny white obelisk to your wall and run the cabling up to your panels. Then you sip on coffee while enjoying being green. \n\nThe charging controller, all safety equipment etc are all built into the battery. It's also much more compact and the battery controller is kind of good because it can isolate bad cells without taking the entire system offline. Dead batteries become more like dead pixels in a monitor, than a show stopper. Any fires are safely contained in it's compartmentalized interior. Bad cells can be replaced easily and safely. \n\n\nThis is strictly a DC device, it will not power your house without the additional purchase of a DC to AC inverter, which get very expensive the more watts they are to supply. And if you want to charge the battery pack without solar panels you would also need to purchase an AC to DC converter, which is much cheaper than the DC to AC one. ",
"Economy of scale once his battery plant comes online and hanging this on the wall is *much, much* less complicated than getting permitted for a large bank of lead acid batteries in some (most? all?) urban areas. When I looked into solar a few years ago in Las Vegas, your only real option was a grid inter-tie system. That's great because you get to use the grid as a free, 100% efficient virtual battery, but it still cuts your power when the power goes out.\n\nBuilding codes required a traditional battery enclosure required an external building that was vented properly for the explosive gasses that are generated during charging. A bunch of expensive batteries in a building in the heat of Las Vegas equals a huge decrease in their lifespan.\n\nThe labor involved in hooking this into your system is much less than assembling a large pack. The Powerwall still requires an inverter and such, but you can buy a bank of them with a ten year warranty for much less than what lead acid would have cost when I last checked.\n\nAlso, if you're on a Time of Use Plan, these could charge at night when it's cheaper, then supply during the peak times instead of drawing from the grid. Once again, depending on your inverter.\n\nIt should be noted that the largest electricity users in houses is air conditioning and that is not listed on the Powerwall webpage. It would take quite a few of these to power an AC unit (220VAC, ~15A).\n",
"It isn't. What they don't tell you is the $4,000+ install fee and using it can end up costing as much as $0.30kwh which is as much as three times as just purchasing power. The facts about converting US to non-fossil fuels maybe true but their battery isn't the answer. \n\nSource: _URL_0_",
"It's really not, but it's from the Apple design book: It's pretty, and it's easy. You can run a deep cycle lead cell battery system of the same kWh for a third the price, but you have to do it yourself and it takes up a lot more room, and doesn't look nearly as nice. \n\nThe Tesla system is consumer friendly, and that's important when trying to get people to switch to a new tech.",
"I work in the solar industry and install systems.\n\n\nFirst solar costs are coming down for a bunch of different reasons. More people are going solar cause they can lease a system and pay for power at a co constant rate and that price won't ever go up (unlike utilities which charge more for lower each year).\n\n\nSo because leasing panels is so cheap and install, set up and interconnection is covered by most full service solar companies you get a good deal, except you're still tied to a power grid and your solar system is worthless at night. But now that we have a new battery that is easy to install, set up, and place anywhere in your home that works better then any battery system that only costs 3 grand is a big deal because it's accessible to current/new solar users and tesla isn't preventing people who use other systems outside of his parent company to use this battery. If you can make solar energy useable all hours of the day, simple, cost effective then that is something to celebrate.\n\n\nIf you look up battery systems they are complex and fucking ugly",
"It's mostly for the utility market. However, homeowners and business are encouraged to purchase as well to take advantage of battery scalability. Elon Musk is working towards a renewable energy cycle and transitioning to massive energy storage is part of it. \n\nThe battery wall is different in that it is intended to be unobtrusive similar to a sculpture or piece of art. At least that is the intent. This way people are more inclined to have a battery hanging in their garage, or on the outside of their walls.",
"Quoting from future comments: \n\n\"Baww too expensive, too heavy, too much heat, too much environmental damage, why can't I get a girlfriend, not enough power, not enough sex, not enough money for me, it will never work, why do I yankee my wankee about science yet hate every science story, only internal combustion produces enough energy to haul my hairy fat **ASS** out of my feces-encrusted basement, solar sucks, renewable power sucks, everything except my personal opinion violates thermodynamics, my diaper is full.\" \n\nThat about cover it? \n",
"Most replies are from a US homeowner perspective. As someone who grew up in India, this is what I thought:\n\nIn countries like India, very few cities ever get 24x7 electricity. You can be a millionaire, but still you can not have 24x7 electricity unless you install some sort of an expensive backup system. Almost every middle class and richer family owns a battery or fossil fuel based backup unit for their house and from the smallest business to the largest industry, uninterrupted power supply is always a huge issue.\n\nThe existing battery based solutions have many of the issues that Elon Musk pointed out in his announcement. They use old-school batteries (no thermal management, nasty leaky chemicals and toxic fumes). They also need special storage areas and most don't \"just work\". At $3500 for a 10kWh storage, it is a little more expensive than some existing good quality devices, but it really isn't that much more expensive! Reliability and easy of use are very important and if Tesla can make a reliable and high-quality product which is also scalable enough that even businesses can own, then it will be a huge deal in many parts of the world.\n\nAlso if you tie it to other sources like solar, then many remote locations that were never connected can also have some power! (Think of hospitals, internet access stations etc.). \n\nIf Tesla can deliver all that they have promised, it can make a huge economic (and environmental) impact across the world.",
"The new power pack is cheaper, cleaner, and easier to install in your house. It will be the iphone of home storage. I.E. the tech had been there before, but this solution is so elegant and makes so much sense that it will have widespread use. \n\nIt should be said that He's done something similiar with solar city and has made a killing off of it. \n\nBtw, more efficient energy use means cheaper energy for the rest of us if deployed on a wide scale. ",
"It's like the iPhone. It's not really anything new, but it's very nicely packaged, it's more available to the average consumer, and it's actually got some marketing behind it.",
"Power is difficult/expensive to store. Nuclear stays on 24/7 and provides constant power. Solar and Wind are not constant sources of power. This makes Nuclear more useful thanks to it's consistency. If we could store the energy from renewable sources, they become more feasible. The Tesla battery tries to fix this problem.",
"It's not until its affordable enough that you can get 75% or more of the general populace to buy into it.",
"This solution is only feasible is we had the rare earth metals to make these boxes in huge quantities. The reality is that we couldn't make every sedan in the US a hybrid, let alone fully electric because of the resource constraint.\n\nThis box simply can't exist in the quantities Tesla is promising. Lack of supply will kick in and the price for the raw materials and the batteries themselves will explode during adoption. It changes nothing except getting people to talk about Tesla.",
"You can store cheaper electricity to use during times when the cost of power from the grid is more expensive. You're not going to get an immediate ROI, this will take a few years. Also, people take electricity for granted. In countries like Lebanon for example, electricity is not distributed 24/7. In Lebanon, they literally divide the grid in sectors, they supply 6 hours to one sector while the others are off, then they switch that one off and supply for 6 hours to another one, then after that they go off and you're back on. Basically you only get 12hrs of supply per day. You could charge the batteries while the electricity is on, so when it's off you won't be without power. And just in case you're curious, hospitals and other essential buildings use petrol generators. The batteries are silent and compact whereas a generator is noisy and bulky.",
"This will be a hit in europe. The difference between day and night rates are outrageous. They use heaters that store thermal energy during the night and release it during the day. By adding storage capacity to a house and to the grid as a whole it eases the burden on power companies",
"In the long term this will move us towards distributed power supply and production. Which means we may be able to make electricity no longer a utility, but a rather a distributed form of collaborative infrastructure. Long distance power providers would essentially become arbitrage companies.\n\nIn addition individuals and businesses would become more self sufficient. A terrorist attack on power plants would no longer a national emergency crippling a fourth of the country, but also this provides immunity from rolling blackouts.\n\nIn the short term, this simply makes it easier to use personal solar panels, which is really starting to take off.",
"Technically its not. Other companies already have this, and have for a while. But people like Tesla cause they are good at PR.",
"Before, the best you could hope for solar power to achieve (if you had solar panels on your house) would be to reduce your drain on the grid. You would use less electricity but you would still need to be hooked up to a grid because you need electricity at night when the solar panels are not working. People who have solar panels could have always used batteries of course, but there's a heap of problems attached to that, which the Powerwall basically solved and it's no small technical achievement. \n\nI used to live in a farming community that used wind power in remote locations because they had no choice. They were way too far away to hook up to the electrical grid. So it was wind power or use a diesel generator which sucks up money. There was this one farmer I knew who lived next to a wrecker and he used to take dozens of car batteries and he hooked them up together to a windmill. It was unbelievably nasty. If you neglect something like that in the open there is corrosion, and leaking noxious chemicals that are dangerous. You have to be super careful where you place batteries like that. He stored the batteries on top of gravel because nothing will ever grow there ever again. It smells bad. It's seriously something you don't want in your house. \n\nAnd there's another problem. Let's say you decide to hook solar panels and use batteries to power your house at night. There are no batteries you can buy that have a built in industry standard that allows you to conveniently hook them up to power your house. You're going to have to hire an electrician, possibly an electrical engineer, to build something for you. That would be pretty damn expensive. Most houses I ever saw that have it were specially built for that purpose. They had a storage place specifically for those batteries that is dry, ventilates out of the house, and is safely built to electrical code to supply power. Not easy.\n\nNow it's easy. The Powerwall is a battery that has basically created an industry standard that has never existed before. A battery that is not adopted or modified, but is purpose built to work to power your house. Yes, it will still have to be installed by an electrician, but they won't have to build anything, they just have to install it. \n\nWhat this does is instead of just reducing your drain on the grid, you can go off it altogether. Depending on what your electrical needs are. Remember the name of the house battery? 10KWH? That's ten kilowatt hours. The significance of that is the average daily use of electricity in an American home is 11 kilowatt hours. That's the equivalent of using 1 kilowatt of electricity for 11 straight hours. So 10 is pretty damn close and you can expect to get your house to under ten by simply switching to energy efficient appliances. (Don't worry about your computer, TV, gaming consoles, their electricity use is bugger all.) It's your washing machine, dryer, and refrigerator is your biggest drain. And if you are using old-fashioned light bulbs, get rid of all of them and switch to energy efficient, that's a big difference right there. \n\nThat means for an entire day the Powerwall battery can power your house on a single charge. Which means it should be good enough to last at night when your solar panels are not working. So during the day your solar panels power your house and charge up the Powerwall, and at night you get power from the Powerwall . That's the point of the whole thing. \n",
"If everyone is charging during non-peak hours...are they still non-peak hours?"
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"http://www.luxresearchinc.com/news-and-events/press-releases/read/tesla-motors%E2%80%99-gigafactory-will-see-more-50-overcapacity-its-li"
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afy7hn | how did old ships pull up their sails without bunching or tangling? | When sailing ships (1400's to 1800's-ish) needed to go faster, they would open or 'drop' their sails to take more wind.
How did they pull them back up when they needed to slow down? What kept the sail itself from just flopping back out or sagging down when they were being pulled back up? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/afy7hn/eli5_how_did_old_ships_pull_up_their_sails/ | {
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"Pirate here.\n\nOne part is stowing the sails properly. When you lower a large sail, you fold it back and forth (accordion fold) so that when you haul up the top, it naturally just unfolds in steps without tangling.",
"For square sails they sent men up onto the beam to grab the sail by hand and to secure it. Men below, played out rope attached to the bootom of the sail as they did this so the sail wouldnt flap around too much.\n\nWhen increasing sail, they did this in reverse.\n\nFor triangular sail, the rope they pull is attached to the top.\n\nFor some types of ship, like viking longships, they would raise or lower the whole beam. And then do all the work at deck level.",
"If you look at a photo of a square-rigged sailing ship, you can see a bunch of short strips of canvas hanging in rows on the front of the sail. These are “reefing points”, and they are tied to shorten the sail. "
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25mzik | If Irish people were discriminated against in Early american history, why didn't they try to pass as English? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/25mzik/if_irish_people_were_discriminated_against_in/ | {
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"Two major reasons. One, the obvious difference between the two- Irish immigrants tended to form tightly knit social communities, partially due to being forced out of/kept away from other communities and partially for their own protection/homesickness/desire for social cohesion. This made it so that they largely retained their distinctive characteristics- **accents**, religion, diet (in fact, there still exist almost entirely Irish communities in large industrial cities such as New York or Boston). Two, the Irish have a staggering national hatred of the English (to GREATLY simplify several hundred years of political upheaval), which makes the likelihood of an 18th or 19th century Irish family choosing to pretend to be English very little.",
"The simple, but unsatisfactory, answer to this is that we probably don't know how many Irish emigrants tried to pass as English. \n\nI'm not aware of any academic literature on the subject, but it seems unlikely that nobody would have tried. Beyond the obvious pride in where one came from, some people would undoubtedly have seen that the English were a step above the Irish on the social ladder and tried to take advantage of it.\n\nThe practical obstacles, more than any sort of anti-English or religious feeling, would be more important I think. Bearing in mind that the majority of Irish emigrants would be native Irish-speakers, most of whom would have little formal education, it's unlikely that they'd have had the ability to pose as English.\n\nOf course, not all emigrants were economic migrants. There was a proportion of the reasonably wealthy and educated classes from Dublin - who would be native English speakers - who sought a better life in America. It may well have suited them to pass themselves off as English. "
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9gmuhg | I've often heard that the Battle of Britain was won by the Hurricane since it was so cheap to produce Britain could outnumber the more advanced German planes. Whilst the Spitfire was mostly used for propaganda as it was the "sexier" aircraft. Is this true? | Obviously RADAR played a big part too but did mass produced British aircraft give Britain air superiority? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9gmuhg/ive_often_heard_that_the_battle_of_britain_was/ | {
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"The Battle of Britain is indeed a major reason for the Spitfire becoming an icon, a battle in which the Spitfire \"plays the mythological role of a magical weapon, the equivalent of [...] Excalibur\" (Stephen Bungay, *Most Dangerous Enemy*). As James Holland puts it \"No other veterans of the Second World War are as hallowed as the Few [Churchill's description of RAF pilots in his famous [tribute] (_URL_1_)], but equally no aircraft is as hallowed as the Spitfire. This aircraft, above all others, has gained an iconic reverence not given to any other. (...) No wonder that generations of children have built models of this beautiful aircraft, or that thousands still flock to air shows every summer to watch them fly.\" For the UK the Battle was a defining moment of the war, before the massive contributions of the USA and USSR came into play, when Britain stood alone (though of course it wasn't *really* alone, with the rest of the Commonwealth behind it; around 20% of RAF pilots in the Battle came from overseas). \n\nMost people with an interest in the Battle are aware that the RAF had almost twice as many Hurricanes as Spitfires (34 squadrons compared to 19), and they shot down more German aircraft (1,560 claims compared to 1,189). It certainly wasn't a case of outnumbering the Luftwaffe - the Luftwaffe outnumbered the RAF around 2:1 in July 1940 considering all types, it had 1,107 single-seat fighters to Fighter Command's 754. Radar, as part of the wider air defence network, was indeed essential to allow those aircraft to be deployed as efficiently as possible. The RAF's fighters had to have good performance to quickly climb from their airfields to engage incoming raids, and to be able to engage German fighters; though the Hurricane was slower than the Spitfire and Bf 109 it could turn more tightly than either, it could hold its own in a dogfight and was more than a match for German bombers. Where possible Spitfire squadrons were used to strip away fighter escorts from formations of bombers for the Hurricanes to engage, though in the chaos of air combat such distinctions often became moot.\n\nThe Hurricane was a less revolutionary design that the Spitfire, it had a fabric covered fuselage and thicker wing, making it was easier to build and repair - important considerations for a battle of attrition, as the Battle of Britain was. Production of airframes alone was only one element, though; someone had to fly them, pilot numbers were the critical factor by the end of August. Some considered the Hurricane a better aircraft for average pilots, a \"brick-built shit-house\" (in the words of Bob Doe), sturdy and reliable and easier to keep the guns on a target, but for a good pilot the superior performance of the Spitfire made it deadly. It wasn't mere \"propaganda\", on a per-aircraft basis Spitfires made more claims than Hurricanes. The Spitfire did catch the public imagination more, probably slightly unfairly; [Spitfire funds] (_URL_0_) were set up all over the country, raising a huge amount of money for the government, much to the chagrin of some Hurricane pilots. As Bungay puts it: \"[The Hurricane] was very good, but a somewhat plain and homely country girl, well-behaved and reliable. [...] [The Spitfire was] a real glamour-puss, a lady of such refined but curvaceous beauty and class that she instantly seduced every young man who climbed into her cockpit, and with such charisma that the public as a whole just stopped and stared every time she passed. They still do.\"\n\nThe Spitfire also had greater longevity than the Hurricane, its fundamental design allowing ever more powerful engines to be fitted in, ultimately, 24 different marks. The Hurricane performed sterling service in overseas theatres and was replaced by the Typhoon then Tempest, the Spitfire remained the primary air defence fighter of the RAF throughout the war. The two aircraft were both vital elements during the Battle, and though the Spitfire might be a bit of a glory hog, almost blotting out the rest of the RAF in the public imagination, it was (and is) a great, and beautiful, aeroplane, not a case of style over substance.\n\n(See also [a previous post about the Spitfire](_URL_2_))"
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"http://www.bbc.co.uk/learning/schoolradio/subjects/history/ww2clips/speeches/churchill_the_few",
"https://www.reddit.com/r/AskHistorians/comments/919h5m/what_was_so_revolutionary_about_the_spitfires/"
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gkhod | I just realized that one of my eyes is slightly higher than the other. How normal is this? | My right eye is slightly above my left. It's fairly noticeable when I wear glasses; if I align them with my eyes, they're crooked on my face, and if I align them with my nose/ears, one eye sees above the lens while the other sees through it.
I assume there's some degree of asymmetry to every face, but I thought it was mostly cosmetic stuff and not structural. How normal is this? What is it caused by? Something like sleeping on one side too often when I was a baby? | askscience | http://www.reddit.com/r/askscience/comments/gkhod/i_just_realized_that_one_of_my_eyes_is_slightly/ | {
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"I'm the same way, by about a centimeter..",
"I seem to remember reading that this is called hyperphoria, although I can't find any solid references at the moment. I looked it up several years ago because I noticed that [Lisa Edelstein](_URL_0_), who plays Dr. Cuddy on *House, M.D.*, has this.",
"It is likely that this asymmetry & many other small differences appeared during your development in the womb & were caused by an instability in the growth patterns.\n\nIt is very unlikely that sleeping on one side could create such a structural change.\n\nGenerally it's thought that bilateral symmetry in our features is attractive because it is an good indicator of having genes that have allowed you to cope well with stresses such as disease or reduced resources during development. \n\n"
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i4jdj | What, in your view, is science? | What makes science different from other disciplines of inquiry (for example, economics, philosophy, or art)? | askscience | http://www.reddit.com/r/askscience/comments/i4jdj/what_in_your_view_is_science/ | {
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"_URL_0_ says\n\n > a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the world.\n\nTestable explanations and predictions are the key things there. You don't find that in philosophy or art. Economics is a science.",
"The application of the scientific method: observe, question, guess, predict, test, revise, repeat.",
"The maths. I can \"do\" philosophy and art without having to spend sixty hours a week wrestling with linear algebra. I'm still looking for a way to learn legitimate physics that way, and haven't found it.\n\nIf you can draw accurate error bars on it, it's a result I can care about. If you can't, it isn't. I'm not bothered about finding a hard and fast definition of \"science\", but the above is pretty functional for physics and a lot of chemistry.\n\nEdit: Generalists who are expert contributors to everything don't exist unless you count mathematicians, and it's unsurprising that their results are widely applicable given the abstraction of the subject. I don't *need* a general definition of science in almost all cases because I haven't come across anyone who did not specialise.",
"In [this interested TED talk](_URL_1_) physicist [David Deutsch](_URL_0_) draws a very interesting distinction between 'explanations' and 'hard-to-vary explanations'. His description of the scientific process varies from the Wikipedia process in that it requires explanations to not only be testable, but not be easy-to-vary. In essence, his argument is that explanations must be minimal - they should not contain details that can be changed without changing the predictions of the theory.",
"_URL_0_\n\nSee the section on the Philosophy of Science."
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3p4b10 | why aren't bananas juicy like other fruits? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3p4b10/eli5_why_arent_bananas_juicy_like_other_fruits/ | {
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"Bell peppers aren't juicy fruits. Bananas are extremely juicy. My grandmother's recipe for old bananas with spots was the best way to get the juice out.\n\n1. Put old bananas into a pot.\n\n2. Pour ONLY 1 tablespoon of water for every banana.\n\n3. Seal the pot with a lid.\n\n4. Alow to cook on 1/4 heat.\n\n5. After 10-15 minutes remove and you'll find out just how juicy bananas are. ",
"seriously though, what did she do with the bananas/liquid after?"
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2z0jx6 | money in politics | I hear a lot a lot of talk about money in politics, but what does it actually do? The only thing I can see is it buys marketing.
Take medical marijuana. "Big pharma" (pardon the cliche) spends massive amounts of money fighting this but what does it matter? I'm still going to vote how I do no matter how much they spend. Neither me nor my demographic say "Well looks like I'm gonna vote against this because big pharma said so". In the end of the day votes get you in office and short of fraud you can't buy votes.
Maybe I'm not totally immune to marketing but I think I can say I never voted based on a TV ad. Everyone, even the uninformed, knows the ads are BS.
So how does money in US politics work and how does it guarantee you a win? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2z0jx6/eli5_money_in_politics/ | {
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"There's a very slim slice of people who haven't already been influenced by what they've heard and could still be influenced by more messaging. However, in a very close race a very thin slice of voters make a very big difference in outcomes.",
"You're right, 40% of voters feel a certain way about a candidate, 40% feel the opposite, and no amount of money is going to change their vote. But often elections are decided by that indifferent, unengaged 20% in the middle. You need to reach them and somehow drive them to the polling place to vote for you. That takes money."
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yqdtf | Was the Westphalian Order inevitable? | Basically, I'm wondering if the Treaty of Westphalia (or something like it) was a "natural" progression of trends leading up to it, or whether it was more of an idea that was present and Westphalia really got the ball rolling? It's usually presented as the beginning of the modern state in contemporary IR, so I'd love to hear about the debates. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/yqdtf/was_the_westphalian_order_inevitable/ | {
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"Inevitable is a strong word, but attempts to establish exclusive territorial dominance do seem to be a strong constant in human existence, and numerous such dominators rubbing up against each other are always seem to produce something vaguely westphalian, though the precise norms differ from place to place.",
"If you mean in history the answer is no, look at the History of East Asia where there has usually been a hegemon (China) who often interfered in the affairs of its neighbors (modern Korea and Vietnam, but it also includes the many peoples whom China absorbed over time). \n\nIf you mean specifically in Europe, the answer is probably yes. The Westephalian Order laid the foundations for what later became nationalism (since it began the creation of nations) and was the natural outreach of an increasingly prosperous people who wanted more political autonomy to accompany their rising prosperity. "
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6gz4hd | maslow (1943) hierarchy of needs, specifically aesthetic needs? | Apologies if the flair is wrong. I'm doing a leadership course and the above came up. All the other points made sense. Any explanation online is just waffle. Thanks | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6gz4hd/eli5_maslow_1943_hierarchy_of_needs_specifically/ | {
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"What about them? People get pleasure from apprehending beautiful things. (We know now it's because the brain releases endorphins.) But under Maslow's theory this isn't something you can spend the energy to appreciate when you're starving or anxious about whether you'll have a place to sleep. ",
"The question here can also be pointed out as \"what is aesthetic and why does it feel good\". Our evolutionary upbringing is coded in a way to see and label symmetrical, bright or colourful things as \"beautiful\" because for example, a symmetrical face in a human means that person has a strong immune system and was not effected by any antigens or parasites, thus was able to stay symmetrical. Same thing goes for shiny hair, or non-yellow, whitish eyes. \n\nThose give us signals of health, trustworthiness (it makes your amygdala stop blinking, which means you feel safer) and can even be seen as sexual need-satisfying. The interconnection between sex and aesthetic is making them feed each other. Thus, it is probably a side-effect that is being caused by our sexual interests and mating choices. ",
"if your asking why they exist, it could be said that aesthetic needs are present in the human psyche to prevent depression and suicide, which are obviously not benificial to species survival. Humans always \"want more\". So when basic needs are met, we tend to start asking existential questions. That can quickly lead to depression and lack of motivation The ability to appreciate aesthetics creates a positive emotional state that provides a psychological protective factor, thus promoting species survival. "
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mexs8 | Could it be possible for 'dark matter' to really just be incredibly strong magnetic fields? | I was reading this article (_URL_0_) and started to wonder if perhaps magnetism is responsible for all of the 'extra gravity' we see and base our predictions of dark matter on?
I think this pertains more to non-baryonic matter. not sure. | askscience | http://www.reddit.com/r/askscience/comments/mexs8/could_it_be_possible_for_dark_matter_to_really/ | {
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"Granted, I'm no astrophysicist, but I don't think this can be true. 'Dark matter' basically means that there appears to be more mass in, for instance, a galaxy than we can observe. The answer can't really be incredibly strong magnetic fields, because for the most part, large celestial bodies tend to be electrically neutral. \n\nFurthermore, magnetism acts differently than gravity. Where gravity is an attractive force between massive objects, magnetism creates a perpendicular force to moving charges. I am positive that astrophysicists would be able to distinguish between the two.",
"No. Gravitational and magnetic interactions are fundamentally different. Magnetic fields are created by and exert forces on moving charged particles only. Gravitational fields are created by anything with mass and exert forces on every type of particle.\n\nAlthough we don't know exactly what dark matter is, it's pretty clear from [observation](_URL_0_) that it's not charged (or else it wouldn't be so dark), and it is massive. The effect it has is a gravitational one.",
"Granted, I'm no astrophysicist, but I don't think this can be true. 'Dark matter' basically means that there appears to be more mass in, for instance, a galaxy than we can observe. The answer can't really be incredibly strong magnetic fields, because for the most part, large celestial bodies tend to be electrically neutral. \n\nFurthermore, magnetism acts differently than gravity. Where gravity is an attractive force between massive objects, magnetism creates a perpendicular force to moving charges. I am positive that astrophysicists would be able to distinguish between the two.",
"No. Gravitational and magnetic interactions are fundamentally different. Magnetic fields are created by and exert forces on moving charged particles only. Gravitational fields are created by anything with mass and exert forces on every type of particle.\n\nAlthough we don't know exactly what dark matter is, it's pretty clear from [observation](_URL_0_) that it's not charged (or else it wouldn't be so dark), and it is massive. The effect it has is a gravitational one."
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66x0i9 | why does china value a land barrier between itself and south korea so highly? | They can't be concerned about something like an invasion, or even it being used as a staging area for such at this point, can they? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/66x0i9/eli5_why_does_china_value_a_land_barrier_between/ | {
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"The two (edit: 3) key points I've seen in answer to this question, which I assume is related to why does China not want North Korea to fall: \n \n- China does not want millions of NK immigrants pushing over its borders. It would be a bureaucratic and humanitarian nightmare. \n\n- China does not enjoy having US bases right next to it, especially since our countries constantly argue about things like Taiwan & the other islands in the seas off the coast of china. \n\n- Having a military base next to a country is the definition of having a stage area for a potential war/invasion in the future. So, they'd have every right to raise their eyebrows. ",
"The US has a ton of military presence in South Korea, so the North is basically a buffer zone between China and the US, symbolically and strategically. \n\nThey also basically let North Korea keep on with its bad self because if the North shits the bed, you'll have millions of refugees with pretty inadequate education, health issues (there was a really horrific famine in recent memory), a completely different culture/mindset, and likely physical and mental trauma from whatever violence ensues in the national bed-shitting. China doesn't want to deal with that, and honestly, I don't think South Korea does either. "
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bi78l9 | why do people cringe from scraping sounds? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bi78l9/eli5_why_do_people_cringe_from_scraping_sounds/ | {
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"One theory is that it’s a survival instinct. Big predator with big claws scraping on stone? Cringe....."
]
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7u33wt | Bow Poundage | so if bows used in war had poundage that required training since childhood, what was the poundage of a bow used for hunting, since penetrating the skin of an animal with an arrow is most likely easier than whatever armor soldiers wore | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/7u33wt/bow_poundage/ | {
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"While you are waiting for a detailed answer, you might find [this answer](_URL_0_) helpful, particularly the concluding comments from u/Hergrim",
"Saxton T. Pope tested a number of bows from around the world and found that they had draw weights ranging from 26lbs to 80lbs. Most of them are between 40lbs and 60lbs and have draw lengths of 22\"-26\". This means that the energy of the bows will be lower than an equivalent draw weight bow with a modern 28\" draw or medieval 30\" draw. Some may have energies of as low as 10j, but would have been used with poisoned arrows.\n\nThere is a caveat to Pope's tests: most of the bows were old museum pieces and may have dried out and, as a result, reduced the draw length and draw weight. C.A. Bergman, E. McEwen and R. Miller conducted a series of tests based on replicas of museum originals, made from the same materials, which do indicate that some of the bows might have had slightly higher draw weights and draw lengths. Of course, there is always going to be some variation in draw weight and draw length between bows, so Pope's bows may have been accurate.\n\nIn the Traditional Bowyer's Bible series, Al Herrin notes that modern Cherokee bows come in two lengths, five feet and six feet. The shorter bows mostly draw 45-55lbs, while the longer bows draw 60-80lbs. There is also a reference in the third volume to the Liangulu, an African tribe, hunting Elephants with bows of over a hundred pounds.\n\nIn practical terms, Pope his friend Arthur Young hunted bears with bows of 75lbs, though Young considered a bow with a 28\" draw length and 50lb draw weight to be adequate for bear with sufficiently sharp broadheads. Pope also considered 60lbs to be appropriate for caribou. \n\nMy conclusion is that most hunting bows in history were somewhere between fifty and ninety pounds (allowing for a reduced draw weight in Pope's tests), with most being between fifty and seventy pounds. Draw lengths would generally be under 28\", so energy can be assumed to be mostly under 40j.\n\n**References**\n\n*A Study of Bows and Arrows*, *Hunting with the Bow & Arrow*, by Saxton T. Pope\n\n*Experimental archery: projectile velocities and comparison of bow performances*, by C.A. Bergman, E. McEwen and R. Miller\n\n\"Eastern Woodland Bows\", by Al Herrin, *The Traditional Bowyer's Bible, Vol 2*\n\n\"African Archery\", by David Tukara, *The Traditional Bowyer's Bible Vol 3*"
]
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"https://www.reddit.com/r/AskHistorians/comments/7m3tol/medieval_bowmaking_what_materials_lengths_and_bow/"
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60gvd0 | if judges are just supposed to interpret and uphold the law, how can there be some judges that are 'friendlier' to left or right politically? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/60gvd0/eli5_if_judges_are_just_supposed_to_interpret_and/ | {
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"You've said it yourself - their job is to *interpret* the law. As such, there is some room for subjectivity and for a judge's particular opinions to influence their judgement.\n\nFurthermore, many laws are inherently subjective - for example any law which mentions what a \"reasonable\" person would have done.",
"So the thing is, when it comes to interpreting the law, there are different ways that reasonable people would interpret the same laws. These aren't as simple as \"left-wing or right-wing\" interpretations but often come down to some degree of legal positivism vs. natural law.\n\nLet's take the classic case of Roe v. Wade for example. You're a judge and a plaintiff is arguing that she has a fundamental right to have an abortion. How do you interpret the law?\n\nJudge #1 says that our constitution was clearly intended to establish a limited government and the Bill of Rights establishes that. Even if the Constitution doesn't explicitly say so, there's an inherent recognition that humans have bodily dignity that the government cannot violate. As such, the woman has the right to decide what to do with her body and the government cannot stop that.\n\nJudge #2 says that in a democratic society, the people make the laws. The Constitution says nothing about abortion or bodily dignity so we shouldn't assume that it applies unless the people make a law saying so. Instead, the people made a law saying abortion should be illegal and we should respect that until the people change their minds and repeal that law.\n\nBoth of these are reasonable interpretation of the law and come down to how that judge interprets our legal system. The by-product of this is that one judge's interpretation favors traditionally liberal policies while the other judge's interpretation favors conservative policies.",
"Because the interpretation can vary. Let's take a very recent real-world example.\n\nYou're a judge. Let's say you are given two key facts:\n\n1. The president has the authority to restrict entry into the US for people from specific countries.\n1. Some people have already been given the right to enter the country by being granted a visa.\n\nSo, a case comes before you on behalf of a visa holder whose passport is from one of those countries. What do you do? The law says that the president can prevent them from entering the country. The law also says that they are allowed to enter the country.\n\nConflicting laws. They can't *both* be right in this situation. So as a judge, you have to look at the laws, the Constitution, precedent, and so on to decide what to do.",
"Judges who interpret the constitution \"strictly\" tend to have views that align with the right and judges who have more 'loose' interpretation of the constitution tend to have view that align with the left. Its not that the judges favor left or right, it's that the left or right favors just one method of constitutional interpretation each. \n\nNote that the left prefer a loose interpretation because it allows for making more changes; ie 'liberal' where the right prefer strict interpretation as it allows for less change/status quo, aka \"conservative\""
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65lw2a | why did people take photos of wwi and such and how did they do it without killing themselves? were they even real? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65lw2a/eli5_why_did_people_take_photos_of_wwi_and_such/ | {
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"People took photos of WW1 for the same reason people take photos of the War in Afghanistan today, to chronicle it for news distribution and historical purposes. They were in great danger, and many were likely killed doing it. Yes they were real.",
"Some early films of war is likely in som part staged/faked.\nThere is a article [here](_URL_1_) about it.\n\nSom scenes from a famous documentary about the [Somme offensive](_URL_0_) are likely staged. Primary the scene when the troops goes over the top. The documentary had the British audience record for 60 years until broken by Star Wars\n\nBut I would not say that all/a huge part of all images and films was staged during WWI like i would not say that all photos/films today are true. \n\n"
]
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[],
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"http://www.bbc.com/news/magazine-29724852",
"http://www.smithsonianmag.com/history/the-early-history-of-faking-war-on-film-133838317/"
]
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||
1czq5c | Who were the first people to figure out how to eat dangerous foods (like cashews) that animals don't eat, and how and why did they do it? | This kind of topic always comes up among friends and family, and in some subreddits and submissions, so I thought I'd pitch it here. Foods like cashew nuts and almonds (cyanide!) seem fairly dangerous for primitive people to have simply experimented with, and animals don't cook and eat them. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1czq5c/who_were_the_first_people_to_figure_out_how_to/ | {
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"text": [
"There's a new sub, /r/AskAnthropology. Might be better for asking this! :)\n\nEdit: Spelling"
]
} | [] | [] | [
[]
] |
|
9lsgmn | why have no deer species been successfully domesticated? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9lsgmn/eli5_why_have_no_deer_species_been_successfully/ | {
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"They have been. They just aren’t as useful as other animals so it’s usually done for niche things. \n\nFarming or raising cattle /animals of any sort is usually not a high margin business and therefore raising such an inefficient animal (no wool/hair, no milk, low weight/feed, etc etc) means you need some other economic reason or are doing it just because. \n\nEdit: by “no wool,milk, etc” I mean commercially viable. ",
"Deer are big, fast, mean, scared of everything, and just not generally very useful. Those are all strikes against them for domestication.\n\nThat said, reindeer are domesticated in a few parts of the world."
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bskdqq | why does inhaling more smoke over time allow you to inhale smoke without coughing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bskdqq/eli5_why_does_inhaling_more_smoke_over_time_allow/ | {
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"text": [
"The smoke eventually burns away the cilia, small hairs in the throat and bronchial tubes, that help your body know when something isn't supposed to be there. Like smoke."
]
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||
49g3us | Is Visuo-spatial intelligence part of Fluid intelligence? | Fluid intelligence is not thoroughly defined. For example, a lot of visual matrices that involve mental rotation are supposed indicator of Fluid intelligence. However if they also measure visual memory and mental rotation, are they not also measuring visuo-spatial intelligence? If so, does that mean Gv is part of Gf? | askscience | https://www.reddit.com/r/askscience/comments/49g3us/is_visuospatial_intelligence_part_of_fluid/ | {
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"Notionally, they're separate. But it's impossible to test \"fluid intelligence\" without also testing other abilities as well. Fluid intelligence is *supposed* to be about the ability to identify new patterns, learn new rules, etc., but ones ability to perceive the pattern in the first place will affect performance.\n\nSo, it's a problem in the design of the test.\n\nIt's worth noting that under most credible models of intelligence, visuo-spatial reasoning abilities are only partially independent of general reasoning or learning ability. In other words, someone who has greater than average visuospatial reasoning ability will tend to have greater than average ability in other areas as well, because of the existence of a general factor (g, general intelligence, general learning ability, whatever you want to call it). Mental abilities are definitely intercorrelated."
]
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ar7m2p | what determines if something is soluble in fat or water? | Im reading an introduction to chemistry and I just can't wrap my head around what makes an atom get stored in fatcells or not.
Sorry for poor English. It's not my first language. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ar7m2p/eli5_what_determines_if_something_is_soluble_in/ | {
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"It's depends on polarity. The polarity depends on the charges in the molecule and bounds between each atom of the molecule. A solute that is very polar will be hydrophilic (it likes water). A solute that is not polar will be liphophilic (it likes fat). Water is polar. Fat is not polar. \n\n\nI think you need way more than an introduction to chemistry to truly understand the concept of polarity. \n\nOf course, you have to take into account other elements such as temperature and pressure because they affect the solubility of a solute.\n\nEdit: second attempt at eli5. Molecules like water or fat depending on how the atoms are bound together.",
"There is an intuitive example. Think about water as magnetic marbles, while fats are regular glass marbles. Mix only regular marbles, and they mix fine. Same for magnetic marbles, although stirring might be a bit harder, depending on the strength of the magnets. But mix them together, and the magnets will form clumbs since they attract each other while the glass marbles will fill the holes inbetween the clumbs. The same happens with water and fat. The water attracts other droplets much more than fat does."
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8m06zk | Is there a limit to the wavelength produced during electron excitation? | [deleted] | askscience | https://www.reddit.com/r/askscience/comments/8m06zk/is_there_a_limit_to_the_wavelength_produced/ | {
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"text": [
"If the transition is from a bound state to a lower bound state, then the emitted photon energy is bounded above. If it’s a transition from a continuum state to a bound state, there is no upper limit, but an extremely high-energy electron will be unlikely to capture into a bound state."
]
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32mbsv | does my cat get frustrated when he is unable to catch the red laser light? | I play with my cat using a laser pointer all the time, but sometimes I feel like he gets frustrated, like a pie in the sky or a hard video game. What does he feel? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/32mbsv/eli5_does_my_cat_get_frustrated_when_he_is_unable/ | {
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"text": [
"Yes, he is frustrated. Laser pointers really aren't good toys for cats. Cats are hunters, and it's very unsatisfying and frustrating for them to \"hunt\" something they can never catch. ",
"I went to school for veterinary technology and this came up in class one day. The teacher said cats get very frustrated with the laser since they can't catch it. The teacher suggested that you should throw a treat in the laser's path every now and then, so that the cat can catch something."
]
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dlgir9 | how do anesthetics knock you out within 10 seconds of being injected? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dlgir9/eli5_how_do_anesthetics_knock_you_out_within_10/ | {
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"I can be wrong, but i read somewhere that nobody knows. We know it is safe, how long it works, how strong it is etc. But we don't know how it works",
"The biochemical mechanism of action of general anaesthetics is not well understood.\n\nWhat we know about general anesthetic is that it interrupts normal function of your central nervous system.",
"It depends on the anaesthetic. There are a few kinds, and sometimes it's just a lucky accident that it does what it does. One low tech way of describing it is to say that the anaesthetic gets between your brain and the environment - like putting your hand over a socket so someone can't plug a device in.",
"Nobody is actually answering the question: which is how do they **knock you out in 10 seconds** not just “how do they knock you out” which is much less clear.\n\nThe answer as to why does it work so fast is that anesthetics are extremely fat soluble, which means they enter the brain extremely quickly. Anything which can enter the brain extremely quickly will have a fast onset and thus works very quickly.",
"I guess I’m pretty qualified to answer this as an anesthesiologist. The length of time it takes for a drug to take action on the body depends on a few things. Since this is ELI 5 I’ll do my best to keep it simple. The two most common ways to receive a drug are by mouth (swallowing a pill or a liquid), or by having them injected into your vein (IV medications). If you take a drug by mouth, it will take longer to get into your blood stream than if you have a drug given through an IV. Giving medications through an IV will skip the stomach absorption, and will go directly through your veins, go to your heart, and then be pumped to your brain. If you have a very strong medication, like propofol, which is used to put patients to sleep, it will take 1 arm-brain circulation time to take effect, which is generally 10-15 seconds.",
"1)- Fat soluble drugs, small molecular size (inhaled volatile anesthetics) easily pass through the blood brain barrier\n\n2) IV administration. Immediate entry of the drug into the blood stream... takes second for it to circulate through the body then see point 1\n\n3) Some drugs when given for conscious sedation ( small dose of fentanyl and midazolam) patients think they are knocked out, in reality there is a amensic effect and patients don't remember. In reality, they are awake, moving and often talking but remember absolutely nothing....\" They got me on the table and WHAM lights out\". when actually patients may be slightly squirming around (notably with colonoscopies!) which then you receive extra dose of sedatives and that relaxes people more so in turn they don't move.",
"I’m a doctor, but not an anaesthetist, so my info may be incorrect.\n\nThe mechanism of action is that for some drugs, we don’t know how it works, but for others, like rocuronium, we do.\n\nIt works quickly but instant access via IV injection into the blood stream. This molecule then blocks post synaptic acetylcholine receptions and when stronger doses used, indirectly blocks presynaptic release of said receptors. \n\nThat’s why, when waking a person up, with say sugammadex, it is an competitive anticholingeric agent to reactivate the receptors so they can start receiving stimulation again. This means your body resumes function as neurones are fired.\n\nEdit: also for actual anaesthetics (local) unsure if its hypothesised or proven, but it indirectly stops potassium being released intracellularly."
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1fon5a | I know the Holocaust was an extremely terrible thing, but did anything good come out of the experimentations on the Jew's by the Nazi's? | Like were any medical advances discovered through these trials by the evil doctors experimenting? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1fon5a/i_know_the_holocaust_was_an_extremely_terrible/ | {
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"I answered this question a while ago, I'll try and dig it up. The conclusion was that it's mixed. Most of the experimentation didn't really use good experimental methodology, and was just a way of torturing people in new ways. The experiments that seemed to attempt to break new scientific ground fell into this category.\n\nHowever, some were useful because the Germans actually wanted the data, not just a chance to do stuff ethics normally wouldn't allow. Stuff like times for people to freeze and die from poisonous chemicals did produce useable data, because they were attempts to perform unethical experiments, not just attempts to torture people in interesting ways.\n\nedit: That comment is [here](_URL_1_), and it cites [this article](_URL_0_), which is concerned mostly with the ethics of using the data, but goes into the experiments themselves as a background.\n\nFrom that comment, the experiments that were done well enough to theoretically produce results were:\n\n* Freezing experiments (testing reactions to extreme cold)\n* High-altitude experiments (testing how high-altitude exposure is dangerous, and to what extent)\n* Seawater experiments (testing how people would react to only being given seawater to drink).\n* Sulfanilamide experiments (testing a drug to prevent infections. prisoners were given wounds, which were then infected, and the drugs tested)\n* TB experiments, to develop a TB vaccine (people were given TB for the experiment)\n\nThe first two at least produced useful data. The others seem to have not for whatever reason, but they were actual unethical experiments, not just thinly veiled torture. However, things like:\n\n* Poison experiments\n* Wound experiments\n* Artificial insemination experiments\n* Sterilization experiments\n* Twin experiments\n\nWere unsystematic, so they couldn't produce any meaningful data, or were based so heavily on shoddy pseudoscience that they simply were too far gone to be comprehensible.\n\ntl;dr some of the experiments did produce useful data, others were just torture. None seem to have broken particularly important scientific ground, just produced new data sets."
]
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[
"http://www.jlaw.com/Articles/NaziMedEx.html",
"http://www.reddit.com/r/AskHistorians/comments/1dlaum/as_fucked_up_as_it_was_did_the_nazis_actually/c9re85s"
]
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|
b40rgq | how do city buses get their route numbers? | This seems to be the question keeping me up tonight. Rather than trying to find it on google - I’m asking here. Is there any method to the madness of bus route numbering? Assuming each city has their own system? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b40rgq/eli5_how_do_city_buses_get_their_route_numbers/ | {
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"It's largely arbitrary. Sometimes if a route travels along a numbered road, it might be given that route number. Sometimes a route number may be assigned as a tribute to a similar route on a previous bus/streetcar system, or sometimes it's just assigned with little reasoning.",
"Since I don't know for which country you're asking, I'll answer it for the systems I've seen in Germany. If a city has busses and a tram, the trams usually get single digit numbers, the busses that only drive inside the city's perimeters get two digit numbers and the busses that drive to other city's get three digit numbers. Which number they get is arbitrary, though usually the lines that historically where there first have lower numbers than lines that were added later. "
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1eyrx9 | What do we know about late Roman or early medieval birth control/abortion/infanticide? | One thing that doesn't seem up for debate is that there was a massive population drop in Europe in the period between the fall of the western empire and the land clearances of the high middle ages. What does seem up for debate, is why.
So clearly we know the usual tropes, plague, famine, conflict. However I've noticed some historians have made the claim that the population drop can be ascribed to selective birth measures, be it birth control, abortion, or outright infanticide.
Their argument is the need for peasants to have more children is tied to the need to produce more under coercion by a powerful authority, i.e. taxes or rent via the roman state or landed aristocracy. Thus when this authority disappears or weakens, the need to have more children disappears, as if peasants can make their lives easier by not having children (through whatever means possible) because that would mean less mouths to feed and less land they'd be forced to farm more productively, they would do so.
So because of this theory, I wanted to ask, given the moral bounds and guidelines of late Roman/early medieval Christianity as well as its likely impossibility-of-systematic-enforcement, what avenues of population control were available and to a separate degree, acceptable, to a late Roman/early medieval farmer?
Also if you believe this hypothesis is complete and utter BS, feel free to say so and explain why. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1eyrx9/what_do_we_know_about_late_roman_or_early/ | {
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"Interesting hypothesis. \n\nThe most common way to kill an unwanted infant in the Classical world was *exposure* (see Moses, Oedipus, Romulus and Remus, etc). As for birth control, there were several theories around, for example I believe the Egyptians used crocodile poop as a contraceptive (not sure about the source on that). The Romans had a certain herbal cocktail that would cause an abortion ([wiki source] (_URL_0_) ), and it was not unheard of for this to happen. \n\nIf you're looking for something \"post-Fall\" I suggest Dr. Sarah Miller's [Medieval Monstrosity and the Female Body] (_URL_1_). Very interesting, but I wouldn't recommend reading it while eating lunch ;)",
" > what avenues of population control were available and to a separate degree, acceptable, to a late Roman/early medieval farmer?\n\nI'm only going to address this portion of your question, since I can't really comment on the thesis itself. But the ancient and medieval world did have access to numerous methods of aborting or of contraception. You can find references to these in the medical herbals of the time, for example, and you can find prohibitions against them in ecclesiastical texts like penitential manuals. A great resource is [this book](_URL_0_). It covers pretty much everything there is on this topic.",
"The first thing you should do is see whether your source for this hypothesis actually cites sources for the increase of infanticide/contraception/abortion and what sources those are. One source I suspect this person cites are Christian censures against those practices. In the fourth and fifth centuries, we have sermons and episcopal decrees about these issues. It could be argued that these preachers must be making these statements now because there is currently a big problem with infanticide etc. This is the typical way to use laws to make statements about historical time periods. If you pass a law banning something, that thing must have been a problem.\n\nBut this does not have to be the case. First of all, we may see this preaching and legislating because Christian morality had finally supplanted paganism as the elite life-style. \n\nThen there is the chicken and egg: the argument you cite implies that population decreased because of increased infanticide because there was no incentive to raise children. However what if the panic over infanticide was because the population was already decrease for all of the usual reasons and the authority figures needed it to be restored?\n\nThose are my issues with the sources on that matter and how they reflect on this argument.\n\nNext onto the points of this argument:\n\nFirst: how does being taxed and forced to work on someone else's land increase your desire to have children? The government and private land owners needed people to reproduce more than ever in the fifth and sixth centuries, so if there was an incentive where did it go? Writers like Salvian (fifth century) describe an aristocracy and imperial government that was more coercive than ever. And the barbarians who took over weren't exactly laissez-faire.\n\nSecond: Wouldn't being under coercive taxation and bondage to landlords be a deterrent to having children not an incentive? Perhaps you misunderstood the argument of the author here. Sure, once a child is old enough, they can work the farm or help around the house and once they are older still you might be able to ship them off to the army, but there are still years where you not only have another mouth to feed who does not contribute to your farming but you also lose one of your workforce in order to care for the screaming, perpetually-hungry maniac you spawned. Keep in mind we are talking over a decade of raising this kid until they can work as hard as their parent. That's more food that you don't get to eat on top of rent and tax (though technically only the land owner pays tax, Salvian claims that they passed the buck to their tenants). If they could dodge taxes or find a parcel of land to squat on, they might have the room in the budget to have a child.\n\nThird: Where is there evidence that aristocracy and government weakened? Tax burden in the Roman Empire was actually pretty small compared to other pre-modern states, and most landowners were good at making it even smaller (again, Salvian). The barbarians who came in had clearly defined taxation which can be seen in their law codes (the Liber Constitutionum in Southern France, the Breviarium, the Lex Visigothorum in Spain, etc.) The Roman aristocracy also remained in force even after the invasion. People like Gregory of Tours in the late 500s could trace their ancestry back to imperial office holders even 100 years after the supposed Fall. Therefore, even if overbearing landlords and tax men were a good reason to spawn another mouth to feed, there is no indication that they had ceased to exist in Late Antiquity/Early Middle Ages.\n\nFinally, a synthesis.\n\nSo what do we make of the alarm over infanticide and abortion? Beside the Biblical reasons you could cite not to do it (Moses, Onan who performed coitus interruptus and was smitten by God Gen. 38:9), you have a group of land owners, aristocrats and imperial officials who want to increase production. Whereas men like Augustus had incentivized having more children, they did not have the resources to promise \"tax breaks\" or \"refunds\", nor the authority to confront the powerful land owners to play nice. Instead they had to make contraception and abortion unappealing so as to make people raise the children they did not really want. That is why we see so much said on that topic in the Late Empire and early Middle Ages."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/History_of_abortion#Classical_Rome",
"http://www.routledge.com/books/details/9780415873598/"
],
[
"http://www.amazon.com/Contraception-Abortion-Ancient-World-Renaissance/dp/0674168763/"
],
[]
] |
|
4w6her | how accurate are calories per serving on packaged food? how would you test it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4w6her/eli5_how_accurate_are_calories_per_serving_on/ | {
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"You test it by burning the food/ingredients, which tells you how much \"energy\" (aka calories) is in it. \n \nAs for accuracy, that really depends. For labeling purposes, they round down to the nearest 5 or 10 calories.",
"The accuracy really depends on why you want to know the number of Calories. For general diet, the numbers are good enough, but not perfect. I will start with a way you can calculate them yourself, then I will explain how Calories are measured in a lab.\nWhen talking about Calories in food, you are really looking at what many call \"Macro's\" (short for macromolecules, or molecules we need a lot, macro amounts, of). There are four macro's: Fats (lipids), carbohydrates, proteins, and nucleic acids (DNA). When looking at foods, we ignore the nucleic acids because there are just not enough to contribute.\nKnowing the three important parts to the foods (the fats, carbohydrates, and proteins), we can find the amounts of each on the \"Nutrition Facts\" label on all food products. The amounts of each macro are given in grams. In order to calculate the total number of Calories, you have to know how many Calories are in 1 gram of each macro. \n\n* 1 gram fats = 9 Calories\n* 1 gram carbohydrates = 4 Calories\n* 1 gram proteins = 4 Calories \n\nNow we can dust off the old calculator, and figure out the total number of Calories in food. I will use the example of delicious Thin Mint cookies. The serving size written on the box (which is not standardized in the US and can be whatever the producer wants it to be) is 4 cookies. First off, who the Fu... heck only eats just 4 thin mints (whew, almost forgot I was explaining to 5 year olds). According to the Nutrition facts, there are **8 grams of fats**, **22 grams of carbs** and **1 gram of protein**. To calculate, you just multiply the number of grams for each macro by the number of Calories per gram.\n\n* 8 grams of fats x 9 Calories per gram = 72 Calories\n* 22 grams of carbohydrates x 4 Calories per gram = 88 Calories\n* 1 gram of protein x 4 Calories per gram = 4 Calories\n\nLastly, we just add up the numbers we just got and there is the number of Calories in the serving of food. In this case, our calculated number of calories is 164 Calories (72 Calories + 88 Calories + 4 Calories). The printed number of Calories on the box for one serving is 160 Calories. \n\nNow you might ask me why the numbers are different, well that needs a little more explaination, but the very short version is many people deduct the amount of fiber from the carbohydrates (since fiber never becomes energy, we just poop it out in the same form we ate it). To be honest, I personally never deduct the fiber unless there is a lot of it in the food (more than half the number of carbohydrates come from fiber). \n\nThe information above is what you can do at home. If you would like to read on, I will explain how a lab tests the number of Calories (this is the only way I know of to accurately test the true number of Calories). \n\nA calorie (lowercase \"c\") is a unit of energy, the amount of energy needed to raise the temperature of 1 gram of pure water up 1^o Celsius. This might sound confusing, but the definition of a calorie is exactly how they test for the number of calories. Using one of the coolest named devices, a bomb calorimeter [video](_URL_0_), a scientist will put the food (let's say a Hostess cupcake, with the white swirlies) into a small metal container (the bomb). Surrounding the bomb is a pool of water. The whole thing is closed off with a lid and the cupcake is burned. Anyone who has been near anything on fire knows it gets hot, so the amount of energy (now in the form of heat) goes to the water and the water gets warmer. You measure how much the water temperature has gone up, do a little math magic, and you have you number of calories. \n\nIf you have any other questions regarding Macros, Nutrition Facts, or burning cupcakes for science, feel free to ask. \n\nSource: Microbiologist who has taken plenty of biochemistry. ",
"It's pretty accurate. What they tend to do is burn the food, then count how much heat is released (maybe by boiling water and seeing how the temperature rises).\n\nUltimately burning something turns it into water and carbon dioxide. And when your body uses food, it turns it into glucose then other stuff, then other stuff... then water and carbon dioxide. With chemicals, the total energy that is released is the same regardless of how many interim stages. So if you discount what comes out. It is pretty accurate.",
"Talked to a guy at a party once who made BOMBS for a living...\n\n**Calorie bombs**. Literally a sphere casing where you burn everything inside and see how much heat you get out. \n\nThat's how they test/measure calories. \n\nGuy said the packaging material lied all the time with ~20% swings either way. \n\n"
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"https://www.youtube.com/watch?v=VG9YG0VviHc"
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1ve7ep | If you eat the same thing everyday, does your body become more efficient at digesting the food? | Or does it become "lazy" and process the foods slower?
For the sake of argument, let's assume it's a healthy diet and not McDonald's three times a day. | askscience | http://www.reddit.com/r/askscience/comments/1ve7ep/if_you_eat_the_same_thing_everyday_does_your_body/ | {
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"There is a very substantial variation among the microbes present in your GI tract, and some are more efficient at digesting certain things than others. When you maintain a homogenous food intake then whatever gut microbes specialize in that food will grow in abundance compared to microbes less efficient at digesting those foods. Keep to that diet for a very long time (several months), and you can severely reduce the diversity of your intestinal flora.\n\nThis has several effects, which operate in different directions:\n\nGut bacteria specializing in things you *can* injecst will proliferate, absorbing nutrients from your food before you can, reducing the caloric value of your food to you.\n\nGut bacteria specializing in things you *can't* digest will proliferate, breaking down these indigestible materials into things which are on average more digestible to you, increasing the effective caloric value of your food.\n\nMicrobes specializing in food you aren't eating will reduce to negligible levels, so should you ever alter your diet again there won't be enough of them around to help you digest the new food. This typically means flatulence, diahrrea, or undigested food pieces in your stool. (Sidenote: people who eat beans all the time don't get gassy from them, and whole corn is not 'indigestible'. These foods get that reputation from their effects on people who rarely eat them.)\n\nThe lack of diversity in your GI tract will mean less competition for the microbes there, increasing your succeptibility to gastrointestinal problems of all sorts. [Stool transplants](_URL_0_), which are exacty what they sound like, are actually a fairly common and usually very effective procedure that exemplifies this principle.\n\nUnrelated to digestion, but unless you've picked a food that is [carefully nutritionally balanced](_URL_1_), you will probably be missing some vital nutrient or other from your diet. People are actually quite resilient to nutritional deficiencies in the short term, but keep it up for more than a few months and you will develop one or more of literally hundreds of nasty health conditions.\n\n**TL;DR:**\n\nIn summary, your gut bacteria will get more effieicnt at digesting whatever you're eating, and the net result to your body is uncertain in terms of caloric intake, and negative in terms of health. "
]
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"http://en.wikipedia.org/wiki/Fecal_bacteriotherapy",
"http://en.wikipedia.org/wiki/Soylent_%28food_substitute%29"
]
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