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3ogz3m
|
If you are drawing straws as a group of 6 when is the optimal time to draw?
|
To me it seems like you wouldn't want to draw first because there is only a 1 in 6 chance you will draw the correct straw. But if you draw last there is a 5 in 6 chance the correct straw has already been drawn.
|
askscience
|
https://www.reddit.com/r/askscience/comments/3ogz3m/if_you_are_drawing_straws_as_a_group_of_6_when_is/
|
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"This is a fairly commonly asked question in probability, and you can probably find some iterations of this question using the search function.\n\nSuppose there are N straws, S of which are \"short\". So if you draw a short straw, you lose (or win?). What is the chance of losing if you are the Mth person to pick? (We are assuming there is only one round of picks. See another post of mine for the case of drawing *until* anyone gets a short straw.)\n\n---\nWith replacement\n---\n\nAfter one person draws, the straw is put back and the next person draws. So clearly each draw is independent, and each person has a S/N chance of losing.\n\n\n---\nWithout replacement\n---\n\nAfter one person draws, he keeps his straw, and the next person draws from the remaining straws. The first person has a S/N chance of losing. What about the second person?\n\n* If the first person drew a short straw (chance = S/N), the second person has a (S-1)/(N-1) chance of drawing a short straw.\n\n* If the first person did not draw a short straw (chance = (N-S)/N), the second person as a S/(N-1) chance of drawing a short straw.\n\nSo the overall chance for the second person to get a short straw is\n\n > (S/N) \\* (S-1)/(N-1)+(N-S)/N \\* S/(N-1) = S/N\n\nThis is the same chance of drawing a short straw as the first person! So then by induction, everyone has the same chance of drawing a short straw. It also does not matter whether the drawings are done with or without replacement.",
"You should be able to see this intuitively. It makes no difference to anyone's chances if everyone draws and shows everyone what they got one at a time, versus everyone draws and conceals what they drew until the last straw is drawn, then shows everyone. \n\nFrom there, it makes no difference to anyone's chances if everyone draws-and-hides one at a time or if everyone draws simultaneously. \n\nBut if everyone draws simultaneously no one is distinguished from another by the process. Their chances must all be the same.",
"**Odds of drawing the short straw if you:**\n\n**Draw first:** There's 6 options and one of them is the short stick. 1/6\n\n**Draw second:** 5 out of 6 times the first guy won't get it, and there's a 1 of 5 chance you'll grab it from the remaining five. 5/6 * 1/5 = 1/6\n\n**Draw third:** 5/6 times the first guy won't get it, and 4/5 times the second guy won't get it. You're left with a 1/4 chance if that happens. 5/6 * 4/5 * 1/4 = 1/6\n\n**Draw fourth:** 5/6 * 4/5 * 3/4 * 1/3 = 1/6\n\n**Draw fifth:** 5/6 * 4/5 * 3/4 * 2/3 * 1/2 = 1/6\n\n**Draw sixth:** 5/6 * 4/5 * 3/4 * 2/3 * 1/2 * 1/1= 1/6. Or another way to think about the last step is that *somebody has to get it*, and 100% minus 1/6 for the first five is 1 - 5 * 1/6 = 1/6\n\n**The order you draw doesn't matter.**"
]
}
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[] |
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[
[],
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77hgn7
|
why does leukemia cause leukocytosis?
|
If in leukemia we have a stop in differentiation of the myeloid lineage, how come leukocytosis is such a frequent finding?
edit: sorry this was poorly written, let me rephrase.
Take acute myeloid leukemia (AML). Leukocytosis is commonly present.
AML, is characterized by an increase in the number of myeloid cells in the marrow and an arrest in their maturation. Consequently, myeloid cells shouln't differentiate into leukocytes.
Maybe I'm just confusing it all.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/77hgn7/eli5_why_does_leukemia_cause_leukocytosis/
|
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"I'm not sure I am understanding your question. Leukemia is essentially uncontrolled cellular reproduction - so you'd expect to find lots of the cell type that is being produced. There are many different types of leukemias affecting many (all?) of the different WBC cell lines. Please rephrase."
]
}
|
[] |
[] |
[
[]
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|
3us417
|
why are there musical one-hit wonders?
|
I have always have wondered why some bands produce songs that are one-hit wonders while others produce hit songs for years. I get that there may be novelty songs that catch on, but what about the serious musicians? I assume if they can write or perform one big hit they should at least be able to make a respectable follow-up.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3us417/eli5_why_are_there_musical_onehit_wonders/
|
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"Being creative is a strange thing. Sometimes you just make something that is far better or cliques way better than anything you've ever made before, and its extremely hard to replicate that idea. Especially in music, where its sortof the luck of the draw what people latch onto, its very easy to make a huge song while the rest of your work just doesnt match up in the public eye\n\nTo summarize; for a lot of artists being consistent is their biggest problem to get over.",
"It has a lot less to do with the artist than with the fickle nature of the music industry and pop music. \n\nPlenty of up and coming artists get signed to a label, produce a record that the label chooses to push and market so that it produces a hit single. Then the artist goes back to record a second album. The label pushes the artist to write another hit single, just like the last one. The artist instead pushes to record what they want. The record they deliver is perfectly good and has some great songs, but the label chooses to spend it's money pushing a different hot new artist. Without the huge marketing push, the record does OK but not nearly as well as the last one. The industry mags all reports it as a \"huge flop\". The label drops the artist. The artist goes back to where he started, driving around in a van and playing clubs and recording pretty good music for an indie label, but is now labelled a \"one hit wonder\" forever. \n\nThe reality is that the artist was talented and had a solid fan base, and delivered good records of consistent quality, but the label basically made the choice to push one or two singles to the stratosphere and ignore everything else. If the label had just ignored them in the first place they probably would be \"great indie band that has never had a major label success\" instead of \"one hit wonder\"",
"There are (at least) three factors that go into whether or not a song is a hit:\n\n- Aesthetics. There are certain things that the human brain appreciates, and certain things it doesn't. Unless a song hits a minimum level of aesthetic quality, it won't be a hit. Note that this is not measured by any kind of \"expert\"; but only by the sum of human opinions.\n- Exposure. You can not like a song if you never hear it. Some songs spread quickly, either virally, or because it is pushed by someone with money or connections. Songs that don't spread can't be hits.\n- Social factors. Many songs are discounted for any number of social reasons: like most songs by Black performers through the 1960's. Sometimes these songs pick up later on, when social issues change, but often they are forgotten, meaning no exposure."
]
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[] |
[] |
[
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frp45o
|
What are the qualifiers required to call yourself A Historian™️?
|
[deleted]
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/frp45o/what_are_the_qualifiers_required_to_call_yourself/
|
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"There are no - to my knowledge at least - professional accreditations related to being a 'historian' so anyone can claim to be one if they want to. How far that claim is taken seriously will depend entirely on the audience. In the case of someone like Dan Carlin, I have no doubt that many of his fans would happily agree with his using the label if he used it, while others might be more sceptical. I personally think Carlin deliberately avoids it, to pre-empt his work getting subjected to serious scrutiny and avoid accusations that he is misleading his audience. Generally speaking, many people who do call themselves historians aren't always hugely impressed with the history underpinning his videos, but don't particularly mind as Carlin explicitly isn't claiming expertise.\n\nIf we did want to start defining it more precisely, to my mind there are a few lines you could draw that would make at least some sense. \n\n\n1. Employment. In other words, does someone pay you money in order for you to do history of some kind? We'd be talking people working in history and related departments at universities, published authors, those who work in museums and paid researchers (for films, documentaries and so on, or perhaps as a genealogist). Carlin might fit under this label, presuming his videos are monetised, but this is where this particular definition gets dicey - are presenters being paid for their grasp of history, or their ability to effectively convey information others have uncovered? An even bigger issue, perhaps especially regarding academia, is that employment in these fields is often precarious or entirely unavailable - if paid employment is our line in the sand, an awful lot of people who have and will contribute to historical knowledge get left out.\n2. Anyone with a formal qualification in 'history' - an undergraduate or postgraduate degree seems most likely, but I'm sure there are others out there. You have a piece of paper confirming to the world that you can do history, ergo you are a historian. This makes a little more sense to my mind, but still isn't great. For one, for many people their degree isn't that big a part of their ongoing identity - few history graduates work in history-related fields. For another, many people who are active in historical fields don't have or need such qualifications, including some of our best contributors here. To my mind, it's needlessly elitist and broadly inaccurate to insist on formal qualifications.\n3. Lastly, and to my mind the best option: are you creating historical knowledge? That is, are you producing history (written or otherwise) than adds to our collective understanding of the past? Most typically, this would involve ferreting around in archives and making new discoveries, but might just as well involve reassessing or applying new methods to existing narratives. This to my mind excludes someone like Carlin or the numerous history 'buffs' who read and learn a lot about particular subjects, and often know a great deal about them, but aren't creating new knowledge in doing so. While they may communicate knowledge effectively, they are reliant on others - historians - for that knowledge in the first place. We're hardly talking about a fixed state of being though - the advantage of this kind of categorisation is that it is entirely flexible, offering just about anyone with the knowledge and desire to contribute to our understanding of history to be a 'historian'."
]
}
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[] |
[] |
[
[]
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|
8yr55u
|
what does actual love feel like?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8yr55u/eli5_what_does_actual_love_feel_like/
|
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"I think it feels different for different people. But on our good days it feels like coming home. No matter what day I’m having, the best part of it is knowing that I get to come home and tell my love all about it. It’s consistent love, support, and warmth. Even on the days when he pisses me off, I know he’s my best friend and he isn’t going anywhere so we hash it out and then we’re all over each other again lol",
"Love feels like nothing else in the world matters when you're in their arms. \n\nLove feels like no matter how often you see them, it's not enough.\n\nLove feels like wanting to be with them even when they've hit rock bottom.\n\nLove feels like being okay with being at rock bottom, because being with them means you still have something to lose.\n\nLove feels like rushing home to see them.\n\nLove feels like their laughter being the sweetest sound in the world. \n\nLove feels like their happiness being integral to your own.\n\nLove feels like your heart trying to burst out of your chest and follow them whenever you're apart. \n\nLove feels like your whole heart is wrapped around both of you when you hug.\n\nLove feels like even holding hands with them creates the most amazing fireworks sensation in your heart.\n\nLove feels like your heart exploding over and over, but like... in a good way."
]
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1r7q3s
|
why is milk said to be a good source of protein when it contains only about 3,5 %?
|
There is more protein in potato chips, for example.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1r7q3s/eli5_why_is_milk_said_to_be_a_good_source_of/
|
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"Advertising. \n\nWhile we're at it, it's [not a spectacular source of calcium, either](_URL_0_) [PDF ALERT]\n\nBefore anyone asks how it can be advertising when there are so many different dairy distributors, \"Got Milk?\" was meant to advertise the entire *concept* of milk (and therefore the entire industry) to encourage consumers to drink more milk--by [these guys](_URL_1_), specifically.\n",
"You are looking at the wrong metric. \n\nIt's only 3.5% per weight, but milk is mostly water. If you look at it as a percentage of calories, then it's about 8-10% protein per calorie.\n\nLooking at it that way, the amount protein in milk is roughly similar to eggs (8%-9% protein/calorie).\n\nA potato chip in comparison has only 1% protein per calorie. And a single serving of lay's classic potato chips has 2 grams of protein. So essentially, you'd have to eat 4 bags worth of lay's potato chips to get the same protein from a single glass of milk. BUT, you'd be eating 600 calories worth of chips vs. the 100 calories worth of milk.\n\nTL;DR: Milk is a great source of protein when you look at it as protein per calorie, instead of protein per weight. "
]
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[] |
[] |
[
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"http://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.87.6.992",
"http://en.wikipedia.org/wiki/California_Milk_Processor_Board"
],
[]
] |
|
1iw4va
|
how come the south was democratic in lincoln's time but republican now?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1iw4va/eli5_how_come_the_south_was_democratic_in/
|
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"See the [Southern Strategy](_URL_0_).\n\nIn brief, the Republican party specifically started catering to racists in the south around the same time that the Democratic party was focusing more on civil rights.",
"The Civil Rights Act and Nixon's Southern strategy in 1968. \n\nA Democrat Lyndon B. Johnson signed the Civil Rights Act signing away the racist white south, and Nixon promised to battle the liberal supreme court and took the South from the Democrats. It has been that way ever since but likely not really due to race related issues anymore. \n\n The South used to be filled with \"yellow dog democrats\" as in they would rather vote for a yellow dog than a republican. Funny how things turned out. ",
"Essentially, the terms \"Democrat\" and \"Republican\" meant very different things. When you look at voting maps, many similarities can be seen from back in the 1860s as today - the same political divisions happened, its just that policies of the parties changed. These policies are essentially: Race relations, social welfare, and industrialization. ",
"Because the two parties are super reactionary. The Republican Party (GOP) was founded as a direct response to the Civil War, and was started by a group of abolitionists. Abraham Lincoln was our first Republican president, believe it or not.\n\nIn the mid-1900's, Republicans were opposed to the New Deal coalition which was basically an agenda that served to unite unions and farmers and minorities and intellectuals and create a solid Democratic voting base. In the late 60's, the Civil Rights movement was mostly backed by Northern Democrats, and as many Southerners were moving away from farming and into industrializing cities, they didn't reap the benefits of the New Deal nearly as much. The combination of this made it far easier for Nixon to win the South as a Republican.\n\nToday, we see the Democrats' Civil Rights agenda still a priority, and the Republicans are still very reactionary towards it. (Recent GOP candidate campaigns are *very* reminiscent of the Southern Strategy when they appeal to homophobia.) This is a big part of the reason why Libertarianism is gaining traction, as an aversion to both the religiosity of the GOP and the high taxes, mismanagement, and heavy government control that the Democrats favor. I would not be surprised if in our lifetime one of the major two parties faded away and we had a more Libertarian president.",
"It's not very technical and it breaks down to all the same thing but the simplest answer is that if you look back through time the values of each party cycle. There are times where the 'republican' party was liberal and the 'democratic' party were the conservatives. It cycles slowly back and forth. It's why I refuse to declare a political party. Party values change. You should vote for a person individually not because of the party they are associated with.\n",
"Given Reddit's political leanings, they are probably going to upvote most comments that paint a flattering picture of the democrats, and a negative picture of republicans.\n\nI would like to present an alternative to that view. At least the OP will see it, if nobody else does.\n\n\nAs the southerners became more similar to republican voters in other regions of the country, with rising incomes, their electoral allegiances began to shift significantly, starting in the late 20s. It was more or less a gradual shift over time.\n\nThere are two signifcant areas that significantly slowed that shift from democrat to republican. \n\n1) Tradition. A lot of people swore up and down that they would not vote republican, because that was the party of the damn yankees. (I count my parents among this group. They may have voted for Reagan, but everyone else on their ticket was Democrat)\n\n2) Race - Because the Democrat party had a lot of appeal to minority voters, they swept up 90+ percent of the black vote - which is a much larger chunk of the population in southern states.\n\n\nAnti-Union Sentiment, A Preference for A stronger national defense, a preference for a smaller government, etc. The more the Democrats forced these issues out of their own coalition, the more those voters in the south found themselves without a party to call home. \n\nFor a lot more thought on it, look here.\n\n_URL_0_",
"The Civil Rights Act.\n\nAfter signing it Lyndon I-had-a-hand-in-Kennedy's-death Johnson quietly declared \"We've lost the South for a generation.\"",
"The names for political parties (mainly Democrat and Republican) are arbitrary, when you get right down to it. The parties were formed with certain doctrines but after certain socio-economic changes (such as the results of the American Civil War and the Great Depression), those ideologies can become flip-flopped. Today we see the Democratic party advocating high govt involvement in economics/business but low involvement in social issues, which is \"liberal\" ideology. Republicans today typically want minimum government involvement in business and more so in social issues, adhering to the \"conservative\" ideology.\n\nBasically my point is that the south didn't really change in terms of ideology, but the ideology of the party itself changed. They've pretty much always held conservative values, at least economically speaking. Democratic ideology back then became what we now know as Republican. So the ideology was roughly the same, just the label changed due to the surrounding events. \n\nForgive me for the word vomit, this is a concept I only recently grasped and am still a bit fuzzy on. I hope that helped, at least a little bit!",
"I read through about 50% of these posts. The thread that strikes me most is that the political parties strategize to gain power as the ultimate goal. How do you organize a group to profess your chosen strategy that will ~~gain the most votes~~ enough votes for you to win? Taking the Logic in Sociologically, you adjust your message to match their proclivities. Actual change in the larger group is \"unlikely\" (read that to mean \"far too much work\"). And if the balance shifts through better marketing of a competing group, Marketing 101, find a new segment to pander to. Any time your competition focuses and takes market segment from you, they are weakening in another segment. It really is a zero-sum game.",
"Southern whites were overwhelmingly Democrats from the Civil War until the 1960s, when Lyndon Johnson sighened the 1964 Civil Rights Act. This created a huge backlash with most of the white population in the South.\n\nNixon started the Southern Strategy by using racial coded language to appeal to Southern whites, as his strategy went:\n\n > From now on, the Republicans are never going to get more than 10 to 20 percent of the Negro vote and they don't need any more than that...but Republicans would be shortsighted if they weakened enforcement of the Voting Rights Act. The more Negroes who register as Democrats in the South, the sooner the Negrophobe whites will quit the Democrats and become Republicans.\n\nNow the previous racist Southern white Democrats became Republicans.\n\n"
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||
ncbiq
|
Does sitting in front of a computer screen for too long have any negative affects on one's skin?
|
asdfaf
|
askscience
|
http://www.reddit.com/r/askscience/comments/ncbiq/does_sitting_in_front_of_a_computer_screen_for/
|
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"Light from the screen isn't going to hurt you as much as sitting still does.",
"The main danger would be not getting the light from any other source. The body needs sunlight for Vitamin D and you aren't getting that from sitting in front of a screen",
"Light from the screen isn't going to hurt you as much as sitting still does.",
"The main danger would be not getting the light from any other source. The body needs sunlight for Vitamin D and you aren't getting that from sitting in front of a screen"
]
}
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[] |
[] |
[
[],
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17klx4
|
Why doesn't table salt, or any other ionic salt for that matter, fuse together when in contact with other pieces of itself?
|
more specifically, what has changed in the structure of the salt that stops the ions from attracting one another and fusing together again?
|
askscience
|
http://www.reddit.com/r/askscience/comments/17klx4/why_doesnt_table_salt_or_any_other_ionic_salt_for/
|
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"text": [
"There's an activation energy for forming the ionic bond between the two crystals. The atoms at the edge of the crystal are in a slightly different thermodynamic state than the atoms in the middle. You can write a reaction where two edge atoms combine to form two middle atoms, and there is a change in thermodynamic state in that reaction along with an activation energy which controls its rate.\n\nAdding heat or a solvent which then evaporates are two ways to lower or overcome the activation energy.",
"Mainly two things: 1) Surface defects, your salt crystals are not perfectly flat and thus not perfectly aligned at the molecular level. 2) There's air, water and other molecules adsorbed to the surfaces of your crystals that are in the way.\n"
]
}
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[] |
[] |
[
[],
[]
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|
3om21l
|
Ancient Romans' rooms had very little furniture, carpet, etc., even if they were wealthy. When did the "modern" furniture-filled household become common?
|
I first saw the lack of household luxuries pointed out in Jérôme Carcopino's "Daily Life in Ancient Rome." [Reconstructions](_URL_1_) of wealthy Romans' [rooms](_URL_0_), even in the late imperial period, seem to be devoid of anything other than a couple couches and chairs, and maybe a desk or a bed.
I'm wondering when in history this trend noticeably changed, and people (or at least wealthier people) started to fill their houses up with cushiony couches and chairs, carpeting, cabinets, armoires, etc. etc.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3om21l/ancient_romans_rooms_had_very_little_furniture/
|
{
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"text": [
"The Industrial Revolution certainly increased the amount of furniture and knick-knacks that ordinary people could afford to have, but it's important to remember that museum room reconstructions (even ones from more modern periods, such as those seen in historic houses in the United States) often owe a lot to the aesthetic sense of today, the preferred way of thinking about an historic period, and/or to a desire to increase the floor space for visitors, and so may not be as authentic as they could. Artistic renderings reflect more of the first two considerations, obviously. While we know that the Romans had less furniture than today, you don't have to go very far back in time to find substantially less *stuff* in a home than we consider normal today."
]
}
|
[] |
[
"http://www.1st-art-gallery.com/thumbnail/106048/1/A-Performance-Of-$27the-Fluteplayer$27-In-The-$27roman$27-House-Of-Prince-Napoleon-III,-1861.jpg",
"http://farm6.static.flickr.com/5184/5855237424_6a5610efb1_o.jpg"
] |
[
[]
] |
|
22ok8r
|
What causes us to see "static" that seems to have no relation to the visual stimuli that is actually present when getting up too fast or rubbing our eyes?
|
Apologies if I've tagged this wrong, am I right in assuming that this would come under Visual Neuroscience?
|
askscience
|
http://www.reddit.com/r/askscience/comments/22ok8r/what_causes_us_to_see_static_that_seems_to_have/
|
{
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"text": [
"I think you're asking about **phosphenes**. A Wiki summary:\n\n > The most common phosphenes are pressure phosphenes, caused by rubbing the closed eyes. They have been known since antiquity, and described by the Greeks. The pressure mechanically stimulates the cells of the retina. Experiences include a darkening of the visual field that moves against the rubbing, a diffuse colored patch that also moves against the rubbing, a scintillating and ever-changing and deforming light grid with occasional dark spots (like a crumpling fly-spotted flyscreen), and a sparse field of intense blue points of light. Pressure phosphenes can persist briefly after the rubbing stops and the eyes are opened, allowing the phosphenes to be seen on the visual scene. Hermann von Helmholtz and others have published drawings of their pressure phosphenes. One example of a pressure phosphene is demonstrated by gently pressing the side of one's eye and observing a colored ring of light on the opposite side, as detailed by Isaac Newton.\n\n > Another common phosphene is \"seeing stars\", from a sneeze, laughter, a heavy and deep cough, blowing of the nose, a blow on the head or low blood pressure (such as on standing up too quickly or prior to fainting). It is possible these involve some mechanical stimulation of the retina, but they may also involve mechanical and metabolic (such as from low oxygenation or lack of glucose) stimulation of neurons of the visual cortex or of other parts of the visual system."
]
}
|
[] |
[] |
[
[]
] |
|
fp2nw
|
Is it possible to detect microbial life forms on an extra solar planet? Can microbial life on Earth be detected from space?
|
I ask this because the chances of coming across highly advanced life forms are pretty slim compared to basic bacteria like life. Right now we scan the sky for radio signals which can only come from advanced life. What about the bare basic forms?
|
askscience
|
http://www.reddit.com/r/askscience/comments/fp2nw/is_it_possible_to_detect_microbial_life_forms_on/
|
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"text": [
"No. If we have good telescopes we can maybe determine what the atmosphere of an extrasolar planet is composed of, and from that hazard a guess as to why the atmosphere has that composition. But there's no way to observe bacterial life directly without actually sampling it.",
"The [bad astronomer has a great run down](_URL_0_). The answer, as I understand is this: yes and no. Kepler (and other telescopes), when they detect light from planets, they can analyze the spectrum and from that infer the kind of elements the atmosphere is composed of. There are some elements we expect from known natural process, but if we find an atmosphere full of other elements, like O2, it's a red flag. \n\nWe don't any natural processes other than biologic ones that would create oxygen so if we ever detect one in a far away planet, then it's either a new chemical process or it's life. The same goes for many other chemicals.\n\nThe good news is that we can detect \"life\". The bad is that this is how far we can go, before some new breakthrough in imaging (or rocket engines) allows us to see what's going on."
]
}
|
[] |
[] |
[
[],
[
"http://blogs.discovermagazine.com/badastronomy/2009/08/04/lcross-detects-life-on-earth/"
]
] |
|
3h191r
|
Qing Dynasty Reading List Question
|
Asked a few days ago if it was alright to ask after good books on a particular topic, so here goes: I'm interested in the Qing dynasty, as it coincides with the period in US/European/world history I'm most interested in (I've got this strange infatuation with Queen Anne's War). Plus, we don't seem to get any education in the US on Chinese history, which seems silly to me since they're such a large nation and have been writing things down for years.
There's a book in the sidebar list on the Boxer Rebellion,and I'm currently reading a pretty interesting book on the Taiping Rebellion. I'm more interested in events before this however, maybe pre-1850? Or just a general period/dynasty book.
After I feel like I've exhausted the Qing period, I hope to move into Sun Yat-sen and Chiang and Mao and the 1911-1950 period, but it seems like there's a lot of literature on that time which is a lot easier to find.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3h191r/qing_dynasty_reading_list_question/
|
{
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"cu3c333",
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"text": [
"For a general overview of modern Chinese history I personally liked The search for modern China by Spence, it covers Chinese history in a fairly well from 1800-1990.",
"I would echo DeSoulis' sentiments of Spence's lengthy but fascinating 'The Search for Modern China'. He is thorough and certainly covers all the periods mentioned in your post - the one drawback I find is that he is a little (a very little) focused on role of the international involvement in perpetuating change in China. Though international involvement is important I personally err on Fenby's shade of grey which focuses a little more on the internal schisms and contradictions within China.\n\n\nJohn Fairbanks' 'The Great Chinese Revolution 1800-1985' is another readable introduction. While lacking and sometimes showing its age in places it really hits on interesting informative niches for pages at a time - which is lovely to summon a broader picture of the Qing state. It is much better pre-1945 than post 1945 where, again, its age shows slightly.\n\n\nFor post 1880ish Johnathan Fenby's 'The History of Modern China: The fall and rise of a great power' is very good at the internal political forces shaping China - and goes beyond simply leaving Sun Yatsen as an icon of democracy and rather looks more into the fractious nature of Chinese nationalist democracy (with an eye to explaining Chiang Kai Shek's rise)\n\n\nI find anything by Rana Mitter is good for post 1920ish even if he does oversimplify certain parts.\n\n\nMay I also be so bold to recommend some *alternative* mediums? On EdX there is a great 9 part lecture series on The History of China for over 1000 years. It's by Harvard and really good for a broad overview with useful discussion rooms to reflect finer points. Its section about the Qing dynasty is particularly excellent.\n\n\nI would also suggest BBC4's wonderful 'In Our Time' which has a number of great programmes with 3 leaders in the field discussing specific areas of Chinese History, they have great episodes on the Opium Wars, Boxer Rebellion and Sino-Japanese War.\n\n\nThere are lots more specific works but it seems (correct me if I am wrong) you want to get a broad sense of the dynasty and period rather than a particular interest on, say, rural village life in Wuhan province.\n\n\nEDIT: Grammar"
]
}
|
[] |
[] |
[
[],
[]
] |
|
dl01uc
|
is plastic bad or is our waste management system?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/dl01uc/eli5_is_plastic_bad_or_is_our_waste_management/
|
{
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"text": [
"Plastics greatest advantage is that it does really degrade or break down, even over long periods of time. \n\n\nThis is also it's big problem. It doesn't dregrade or break down. It just sits there in trasheaps. There's nothing we can really do to get rid of it once we make the stuff. \n\n\nSo it's its usefulness that makes it bad. \n\n\nAnd you are correct about waste management, but it should be noted, that nearly all plastic waste in the ocean comes from Asia and maybe some from Africa. The waste management system in industrialized countries works just fine.",
"It's a little of both. A good example is the use of plastic by companies like coca cola. When it was introduced, consumers were stoked to get the opportunity to buy large bottles of soda for the first time..when they just had glass bottles you couldn't really sell more than the standard size. It was too heavy.\n\nThen plastic bottles changed the game..you could sell 2 liters of soda in one bottle, and the selling point was how lightweight it was.\n\nBut fast forward to modern times, and the amount of those plastic bottles that gets thrown away or just littered is staggering. Remember even just one company like coca cola sells millions, maybe billions, of bottles every year.\n\nSo their best bet to reduce waste would be to go back to glass bottles with a deposit, and they are aware of this but refuse to do so. Because it would cost them a little money to manage that system of cleaning and refilling glass bottles.\n\nLike many things plastic is a great invention but we can have too much of a good thing."
]
}
|
[] |
[] |
[
[],
[]
] |
||
zjwdq
|
If medical science continues to advance, theoretically, how long could humans live?
|
In [1900](_URL_1_), life expectancy for an average person in the born in the US was just 49 years of age. In [2010](_URL_0_), the average had climbed to nearly 79 years of age. That's a more than 60% improvement in a little over a century.
This was probably due to better nutrition and modern medical advances.
If medical science continues along this path and we continue to learn more about nutrition, then how long might we be expected to live? Surely there must come a stopping point where we physically expire despite all the medicine in the world? Or could be eventually reach a point like trees which have no definable natural expiration date and live for centuries at a time?
|
askscience
|
http://www.reddit.com/r/askscience/comments/zjwdq/if_medical_science_continues_to_advance/
|
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"text": [
"There's a TED talk on this I'll try find a link. The guy in it talks about how in the near future the idea is to increase life expectancy by at least one year per year. The implications of that are fairly obvious.\n\nEDIT: [Here](_URL_0_). It's called longevity escape velocity, the idea of breaking that one year per year increase threshold of life expectancy.",
" > This was probably due to better nutrition and modern medical advances.\n\nArguably, most of the increase in life expectancy is due to better public health practices rather than medical advances. In the early 20th century, many diseases were on the decline as a result of safer drinking water and better sanitation practices. Life expectancy in the US was rising even before the widespread adoption of medical advances such as antibiotics and vaccination.\n\nMany Americans by and large did not have access to competent medical providers until several decades into the 20th century. Additionally, many American doctors were behind European doctors in scientific knowledge. In particular, many countryside doctors were reluctant to embrace germ theory and there were still doctors in the 1920s in the US practicing medicine the way a doctor would have in the 1820s.",
"I'll quote some wise words from other [redditor](_URL_0_)\n > Technologically speaking, drastic life extension seems inevitable. The body is a machine we are understanding better every day. Once we learn all about the aging process, we should be able to stop or even reverse it. Its just a matter of time.\n\nFrom how I see it, there is no theoretical limit. The only limiting factor is our knowledge on how our bodies work and how to perfect them to be more and more efficient. Much like what we do with technologies",
"If we get to the point where every year we are making medical advances that add more years of life than we lose from natural means we could theoretically live forever. ",
"I recommend reading[ this interview with an anti-aging researcher](_URL_0_) who believes we can drastically extend lifespan by preventing telomere shortening. Keep in mind that it's very speculative.\n\n > ...Apparently, when telomeres become too short, \"cell aging\" occurs. But there is an enzyme, telomerase, that can reset telomeres back to their youthful lengths, suggesting to Dr. Michael Fossel the possibility of radical extension of the healthy human lifespan in the near future.\n\n > Fossel: If your risk remained equal to the risk of 30-year-olds in 1960 in the U.S., as I recall the median life span should be 1,776 years. That's assuming no cause of death other than trauma.\n\nEdit: To keep with this subreddit's standards, I want to emphasize that these claims are hypothetical and unproven. ",
"We do not currently know of any absolute limit on human life span. There are biological limits, such as telomeres, accumulation of mutations, etc. that limit life span, but we also know that they are possible to circumvent. Does this mean that we will one day be immortal? Not necessarily. Such a limit may exist, still undiscovered. ",
"with advances in modern science and a high level income, it's not crazy to think one can live to be 245, maybe 300",
"Was that 49 years the expectancy at birth, or after infancy had passed? The high rate of infant mortality would depress the figure, but I imagine that as an adult, you're more interested in the life expectancy for someone who has reached your age. That has increased, but not as dramatically, particularly when you compare it with non-city-dwellers in less advanced countries in non-tropical areas."
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy",
"http://aging.senate.gov/crs/aging1.pdf"
] |
[
[
"http://www.ted.com/talks/aubrey_de_grey_says_we_can_avoid_aging.html?awesm=on.ted.com_AIvg"
],
[],
[
"http://www.reddit.com/r/science/comments/idc4s/drug_reverses_accelerated_aging_in_human_cells/c22y6p4"
],
[],
[
"http://www.lef.org/magazine/mag98/feb98_interview.html"
],
[],
[],
[]
] |
|
epnp93
|
how do the different ‘happy’ chemicals in your brain work?
|
What causes their production, Why does chemical imbalance happen? Can your body overproduce?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/epnp93/eli5_how_do_the_different_happy_chemicals_in_your/
|
{
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"fekmw6u"
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"text": [
"This isn't something that has a clear cut answer, as the true effect if the different neurotransmitters aren't simple or entirely observable. Every study of them, in the end, involves the question of \"well now how do you FEEL?\" which is so incredibly subjective. And you can over produce them in the sense that there SHOULD be a certain balance between them, and when one is too high and another too low, it can cause issues. Your body is constantly trying to keep the balanced, although it doesn't seem like it does a very good job most of the time lol. \n\nThe general idea is that \n\nSerotonin has an effect on contentment and relaxation and stability on a longer term basis. People with low serotonin tend to have issues with anxiety \n\nDopamine has an effect on reward response, motivation, and drive, but is moreso a short term type thing. Like the feeling you get when you succeed at something, or when that coffee finally kicks in, etc. People with low dopamine tend to have issues feeling motivated and energetic, people with dopamine that is too high, start to move into effects of anxiety. \n\nI know less about norepinephrine, but I believe that it kind of exists between serotonin and dopamine. Maybe as sort of a bridge between the two?"
]
}
|
[] |
[] |
[
[]
] |
|
7w41rf
|
Is it possible for an egg cell to experience nondisjunction of every chromosome, and if so, would it lead to a virgin birth?
|
I was curious about this because of the recent NYTimes article about a species of mutant crawfish which is only female because it can clone itself through total nondisjunction in its eggs, creating clones of itself endlessly. Can such a thing happen in any species, and especially in humans? If it's possible, even if unlikely, would it lead to a virgin birth, as with the crawfish population?
|
askscience
|
https://www.reddit.com/r/askscience/comments/7w41rf/is_it_possible_for_an_egg_cell_to_experience/
|
{
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"dtxs8hn"
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"text": [
"Even if you did have a cell undergo meiosis and experience non-disjunction of every chromosome (46,XX), it would still never experience the signal to undergo mitosis that occurs upon fertilization. If it was fertilized, it would have too many chromosomes. A virgin birth in this manner would not work. Along these lines, you would have better success with cloning. "
]
}
|
[] |
[] |
[
[]
] |
|
4a5wgr
|
What if you cut the Planck length in half? Does physics break down at that point?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4a5wgr/what_if_you_cut_the_planck_length_in_half_does/
|
{
"a_id": [
"d0xohqu"
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"score": [
28
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"text": [
"The Planck length is not a universal pixel size or some kind of minimum length scale, it's just a really small length constructed from physical constants, that is roughly the length-scale at which quantum gravity effects are relevant. Depending on how you phrase your question (it is currently equivalent to \"what if you cut a meter in half?\" the answer ranges from nothing to creating a black hole.\n\n_URL_0_"
]
}
|
[] |
[] |
[
[
"https://www.physicsforums.com/insights/hand-wavy-discussion-planck-length/"
]
] |
||
9o8ul8
|
why can’t natural gas be used on location for home generation electricity and heat?
|
- NG electric plants are very common
- NG piped to homes for furnace heat is by far the common common heating method
- NG backup generators are commercially available at any big box store, like diesel generators.
There’s probably an obvious reason for it. But it seems like a waste to burn NG for electricity at the plant (and waste the heat), and then also burn it at the home for *only* the heat. Why can’t we generate power on site and heat our homes with the by-product?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9o8ul8/eli5_why_cant_natural_gas_be_used_on_location_for/
|
{
"a_id": [
"e7sbjaw"
],
"score": [
8
],
"text": [
"We can and do. I have been at a home that used NG for heat, and had an NG backup generator in case grid power failed."
]
}
|
[] |
[] |
[
[]
] |
|
4ixlkm
|
how does amazon prime's free shipping actually work? with its popularity, are they losing money? how does it affect ups/usps?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4ixlkm/eli5_how_does_amazon_primes_free_shipping/
|
{
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"text": [
"The thing about being a Prime member is that you're inclined to always purchase from Amazon. They make up any difference on volume of sales.",
"I believe Amazon has spent a great deal of time and money working out logistics to the point they can afford to do that. They also do lots of r and d to improve their shipping processes. \n\n\n\nFor instance, in Canada, almost all companies ship from their warehouses in Mississauga Ontario making online shopping for those on the west coast an absolute nightmare shipping wise. Amazon however has spent the time and money building warehouses in both Ontario and British Columbia to provide cheap shipping.\n\n\n\n\nThey are in fact posting losses each year, but from what those in the know say, it's perfectly normal since its in the interests of establishing themselves.",
" They still pay UPS and USPS for shipping. The cost of shipping, as well as site management, warehouse labor, R & D, and the ever important exectutive pay are all factored into the price of the item you are buying.",
"1. It works by signing up for the membership. Once you are a member, any purchase marked prime eligible will be shipped for free, usually 2 day.\n\n2. Not really. The volume of sales from prime members far outpaces the cost of offering the free shipping. I personally order from them at least twice a week because there is no penalty for me doing so. With their incredible shipping volume, they also pay much less for shipping and you or I would.\n\n3. It might be one of the last things keeping USPS afloat. They ship a lot via USPS from local distribution centers.",
"Amazon doesn't pay the same shipping prices that individuals, or even many other businesses pay. \n\nThey deal in a massive volume, and do a good amount of sorting for UPS and FedEx before the trucks even leave the warehouse. ",
"The volume helps assuming people buy more. You also have the 90 dollar membership fee that off sets some of this. \n\nAfter watching years of shark tank there is also the aspect of margins. Even with keystone margins they would still make a small profit, but most products have a much larger margin than that.",
"Keep in mind, it's not free. It's $100 per year.\n\nSome people order multiple items per week and probably cost them more than they're saving but the majority probably do not. So it averages out.",
"Most of the volume of shipments companies like UPS, Fedex, and USPS receive come from businesses and very little of their user-base is the standard consumer. Something you would pay $10.00 to ship would only cost $0.50-2.50 for a business, based on the volume of items they ship though and the deal they have set up with the shipper.\n\nMy employer has a very low shipping fee as long as they ship a certain number of packages each quarter. The fee is readjusted each quarter as needed. We just shipped some newer testing devices to a west coast network operation center for my company and it was $12.50 in total to overnight an insured package nearly a couple of thousands miles away.\n\nIn the case of Amazon, they essentially keep the shippers alive and very profitable with the volume of items they processes. I took a tour of a UPS a couple of years ago and I saw a ton of Amazon boxes being processed. You also have to keep in mind, there will be a majority of prime users who don't fully utilize the value of their membership and just use it twice or so per year for college books or something and a minority of users who do many orders like I do. Each year for the past few years, I've had at least 30 orders from Amazon shipped to my house in the middle of nowhere. \n\nThink of it like any insurance service. The service works great if fewer people are reaching their payed value in return service. Insurance wouldn't work if everyone paid in a few hundred every six months, but got in daily accidents.\n \n "
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
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||
2zj0r7
|
Was the Revolutionary War really as "civilized" as the movies portray
|
I recently watch The Patriot and I'm wondering if battle in the 18th century really began with both armies forming ranks across a flat battlefield and standing still while the other army aimed and shot the front line. It seems like a horribly inefficient way to battle. You're just sacrificing soldiers for no reason at the outset of every battle. Why would the side that gets there first not just shoot then charge while before the other side took aim?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2zj0r7/was_the_revolutionary_war_really_as_civilized_as/
|
{
"a_id": [
"cpjfaqy"
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"score": [
3
],
"text": [
"While you wait for more targeted answers, you might be interested in some threads from the FAQ section on \"[Line Formations aka Linear/Napoleonic Tactics](_URL_7_)\":\n\n\n[**American Revolutionary War**](_URL_19_)\n\n* [American Revolution: When the red coats intially saw the hiding tactics of the americans, was it seen as constoversial as current day \"terrorist\" tactics?](_URL_14_) - 3 comments, over 1 month old.\n * A flaired user gives a detailed post (with primary source evidence) showing the tactics and formations used by British infantry during the American Revolutionary War.\n\n* [When units of ranged troops fired en masse, did individual soldiers pick their targets or fire straight forward/at an area?](_URL_21_) - 41 comments, over 9 months old.\n * The commenters in this thread give detailed answers for British forces during the Revolutionary War as well as 18th century Russian soldiers.\n\n\n[**Why did European armie use Linear Tactics?**](_URL_10_)\n\n* [Did Line Infantry really march into enemy fire at a dignified pace before attacking? (As is portrayed in many films set in the 1750-1812 period)](_URL_5_) - 27 comments, over 2 months old.\n * The commenters list cavalry, organization, and inaccurate weapons as the primary factors and also link to a variety of posts on the topic.\n\n* [Napoleonic Battlefield Tactics](_URL_4_) - 5 comments, over 11 months old.\n * The commenters here summarize the threat of cavalry charges to open order infantry, the morale damage caused by massed volley fire, and the training requirements for large groups of sharpshooting skirmishers.\n\n* [Was the colonial tactic of \"stand in a line and shoot\" really the best tactic for war, or the product of not knowing how to best use guns?](_URL_20_) - 26 comments, over 9 months old.\n * The topmost comment addresses the problems that line formations solved while top level comments below it put it in context with early modern firearm development and also the noise and smoke of the period battles.\n\n* [Please help me make sense of how infantry battles were fought in 18th century Europe.](_URL_2_) - 6 comments, over 1 year old.\n * This summarizes how line infantry actually conducted themselves once in range of opposing formations.\n\n* [Were battles during the time of the american revolution truly fought with two lines of armies standing across from each other with each army taking turns firing at the other?](_URL_6_) - 40 comments, over 8 months old.\n * This thread touches on the threat of cavalry, range limitations, and how period line infantry fit into the whole of contemporary armies filled with skirmishers, cavalry, and artillery.\n\n* [When was the first instance of a bunch of guys with muskets lining up in a line and firing at each other in volleys?](_URL_8_) - 12 comments, over 11 months old.\n * The commenters here summarize the evolution of European firearm tactics European from 15th to the 17th centuries.\n\n\n[**Mechanics of Linear Tactics**](_URL_11_)\n\n* [Why did armies in the 18th and 19th centuries face each other through lined combat?](_URL_3_) - 1 comment, over 4 months old.\n * The lone comment gives a summary of line infantry tactics and also discusses how these soldiers would be used in various phases of the battle with links to other posts on the topic.\n\n* [18th-century battle formations](_URL_22_) - 24 comments, over 7 months old.\n * The topmost comment discusses the use of line and column formations while a top level comment down below it digs deep into how line formations interacted with skirmishers and cavalry to show the importance of closed order units.\n\n* [Did armys really just stand in line and shoot at each other back in the 1700's?](_URL_0_) - 21 comments, over 10 months old.\n * This thread both explains the theory behind the tactic and uses a variety of examples from Early Modern european battles to showcase the mechanics which allowed it to be effective.\n\n* [Would line infantry keep a musket loaded for when they charged, so they could use it at extremely close range?](_URL_12_) - 6 comments, over 1 year old.\n * The commenters in this thread discuss why and how bayonet charges were conducted.\n\n* In \"[What was warfare actually like in the 18th/Early 19th centuries?](_URL_9_)\", a user makes a relevant comment [here](_URL_1_) - 5 comments, over 2 years old.\n * This posts discusses in detail the tactics and strategy of period sieges, cavalry, light infantry, and artillery to show how line infantry filled a crucial role in 18th and 19th century warfare.\n\n* [What books \\(websites?\\) describe the military maneuvers used during battles of the 18th-19th century?](_URL_15_) - 5 comments, over 1 year old.\n * A variety of sources are given by flaired users.\n\n\n[**Evolution of Linear Tactics**](_URL_13_)\n\n* [Can someone give me an authoritative explanation of 17th and 18th century gunpowder tactics?](_URL_17_) - 13 comments, over 2 years old.\n * This thread traces line tactics from their birth in the 17th century to their maturation 18th and 19th centuries.\n\n* [How did the line formation evolve in battles?](_URL_18_) - 89 comments, over 2 years old.\n * The commenters in this post detail how firearm equipped soldiers and eventually line infantry fit into European warfare from 16th century until the early 19th century.\n\n* [European battlefield tactics between pike-and-shot of 16th-17th centuries and line formations of 18th](_URL_16_) - 2 comments, over 1 year old.\n * This thread goes into the development of new bayonets and artillery which favored line formations as well as the unintended effects this had on the decisiveness of battles."
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/AskHistorians/comments/21lz4r/did_armys_really_just_stand_in_line_and_shoot_at/",
"http://www.reddit.com/r/AskHistorians/comments/17pihe/what_was_warfare_actually_like_in_the_18thearly/c87qxan",
"http://www.reddit.com/r/AskHistorians/comments/1iat9j/please_help_me_make_sense_of_how_infantry_battles/",
"http://www.reddit.com/r/AskHistorians/comments/2jz0wv/why_did_armies_in_the_18th_and_19th_centuries/",
"http://www.reddit.com/r/AskHistorians/comments/208jbm/napoleonic_battlefield_tactics/",
"http://www.reddit.com/r/AskHistorians/comments/2ozatt/did_line_infantry_really_march_into_enemy_fire_at/",
"http://www.reddit.com/r/AskHistorians/comments/28dp5n/were_battles_during_the_time_of_the_american/",
"http://www.reddit.com/r/AskHistorians/wiki/war#wiki_line_formations_aka_linear.2Fnapoleonic_tactics",
"http://www.reddit.com/r/AskHistorians/comments/208f5y/when_was_the_first_instance_of_a_bunch_of_guys/",
"http://www.reddit.com/r/AskHistorians/comments/17pihe/what_was_warfare_actually_like_in_the_18thearly/",
"http://www.reddit.com/r/AskHistorians/wiki/war#wiki_why_did_european_armies_use_linear_tactics.3F",
"http://www.reddit.com/r/AskHistorians/wiki/war#wiki_mechanics_of_linear_tactics",
"http://www.reddit.com/r/AskHistorians/comments/1ohgqe/would_line_infantry_keep_a_musket_loaded_for_when/",
"http://www.reddit.com/r/AskHistorians/wiki/war#wiki_evolution_of_linear_tactics",
"http://www.reddit.com/r/AskHistorians/comments/2qectj/american_revolution_when_the_red_coats_intially/",
"http://www.reddit.com/r/AskHistorians/comments/1q7wj2/what_books_websites_describe_the_military/",
"http://www.reddit.com/r/AskHistorians/comments/1hdtif/european_battlefield_tactics_between_pikeandshot/",
"http://www.reddit.com/r/AskHistorians/comments/12gsrv/can_someone_give_me_an_authoritative_explanation/",
"http://www.reddit.com/r/AskHistorians/comments/12xgg9/how_did_the_line_formation_evolve_in_battles/",
"http://www.reddit.com/r/AskHistorians/wiki/war#wiki_related_topics",
"http://www.reddit.com/r/AskHistorians/comments/25mf4s/was_the_colonial_tactic_of_stand_in_a_line_and/",
"http://www.reddit.com/r/AskHistorians/comments/25iroe/when_units_of_ranged_troops_fired_en_masse_did/",
"http://www.reddit.com/r/AskHistorians/comments/29zdx6/18thcentury_battle_formations/"
]
] |
|
359cc6
|
Why can USB/ethernet/etc. cables only be a certain length?
|
Is it to do with interference, electrical impedance, ping, or something else entirely?
|
askscience
|
http://www.reddit.com/r/askscience/comments/359cc6/why_can_usbethernetetc_cables_only_be_a_certain/
|
{
"a_id": [
"cr2hdpr",
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"cr2nffi"
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"score": [
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6,
12,
26
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"text": [
"USB's electrical design doesn't allow it. When USB was designed, a decision was made to handle the propagation of electromagnetic fields on USB data lines in a way that limited the maximum length of a USB cable to something in the range of 4m. This method has a number of advantages and, since USB is intended for a desktop environment, the range limitations were deemed acceptable. USB was always supposed to be the lowest-cost solution for \"slow\" peripherals like keyboards, mice, printers etc.",
"Over longer lengths of cable and across the contacts on inexpensive connectors (built in low cost economic zones by the lowest bidder), the overall interconnect capacitance degrades the USB signal. There is a rounding off of the rise and fall times on these signals to a point where the receiving device can no longer discern the waveform.",
"The reason for the 100m/300ft limit in ethernet cabling is due strictly to limit attenuation and bit error rate (BER). It's been about 15~ yrs since I've used those calculations so I'd have to check back in later with more of a concrete mathematical reason. Or someone with this knowledge fresh in their mind can comment.\n",
"I work directly high speed cables at my job, specifically analyzing their performance. There is a parameter called [insertion loss](_URL_0_) that essentially measures how much the magnitude of your signal degrades as it travels down the cable. That's a bit of a hand-wavy explanation, but it'll work for here. The primary contributor to insertion loss is the length of the cable itself. As you increase the length, you have more loss. There are a lot of other factors that go into it, such as the connector, the quality of the connection, shielding, chemical composition and uniformity, solid copper versus braided copper, and so on, but length usually dominates. The frequency at which you run your signal is also very influential, the faster you send data the more loss you have. Below a couple GHz you don't have to care too much, copper will conduct the signal very well, but once you start hitting the higher frequencies you have to start taking more care when designing the raw cable and the connector.\n\nThink of it like this: a cable is like a hallway and you're trying to signal someone at the other end with only a flashlight. The longer the hall is the less light will reach the other end. Now imagine that someone has put a fog machine in this hallway. The fog represents the losses in the copper. The better the conductor, the less fog. Now imagine that you're trying to send a message encoded by the number of times you turn the flashlight on and off. The person at the other end is watching carefully, but if the hall is too long and the fog too thick they're going to have a hard time making out when the flashlight is turned on. Now imagine that you start strobing it faster and faster, how likely is it that they'll miss one of those flashes? You can always go get a brighter flashlight, or you can try to clear out some of the fog, but you can't make the hallway smaller. A brighter flashlight takes more batteries, though, and when you use a brighter flashlight more of it gets reflected back by the fog. No matter how hard you try it seems like there's always some fog lingering. To make matters worse, the guy at the other end is trying to signal back with his own flashlight, and that's causing interference by lighting up all the fog while you're trying to send him a signal.\n\nThis is essentially the challenge of sending a signal down a conductor. It's far simplified of course, but I think the analogy holds up pretty well."
]
}
|
[] |
[] |
[
[],
[],
[],
[
"http://wiki.pickeringtest.net/file/view/40-876_insertion_loss.jpg/153639573/574x481/40-876_insertion_loss.jpg"
]
] |
|
2lly8n
|
would a "plasma rifle" have recoil?
|
Hey.
So we all see in science fiction how various factions, instead of using mundane weapons, use "guns" that propel ionized & super heated plasma quickly with magnetic fields to burn and cauterize and do fun stuff.
I figured that since it is essentially a type of railgun without a solid projectile it would have negligible recoil with the exception of the air being displaced and causing a shockwave. Then someone contradicted me and said it would, in fact, recoil. I'm at a loss and can't find something to reference authoritatively in the real world. Any of you know?
Edit: Answered, thank you :3 Turns out I was overthinking things and ignoring... well.. the fundamental laws of reality.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2lly8n/eli5_would_a_plasma_rifle_have_recoil/
|
{
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"clw0i0d",
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"score": [
11,
3
],
"text": [
"Plasma still has mass, and must be accelerated, so yes, we can presume that a weapon that shoots plasma at a target will have recoil. Newton's 3rd law and all that.\n\nAs for how much? No way to know without design specifications like what is the chemical and physical makeup of the shot, what is the acceleration profile like, ect.\n\nEdit: to expand on some likely misconceptions about plasma, plasma is a state of (really fucking hot) matter. It is not just \"energy\" without significant substance like light or electricity( yes, I know electrons have mass).",
"Are you suggesting railguns don't have recoil? You state that because it's a railgun in essence, the projectile has no recoil and the only recoil would come from the displaced air. \r\r\rThat simply isn't true. Railguns, be it a plasma or solid sabot, have recoil. They would have as much recoil as a conventional gun powder gun firing the same mass at the same speed. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
7zmfm6
|
how do we know what emotion to name our feelings?
|
Let's say you feel angry...
you have a physical response which for me feels like my chest is tight and my front side is burning.
How did I learn that the physical response I'm feeling is called anger?
My initial guess is when we were younger we would watch our parents and empathize with the things they interacted with
ie they dropped something-- > subconsciously we imagine ourselves in their shoes(empathy)-- > based on their reaction and response we labeled it the same
and if this is true then shouldn't we be able to rename our emotions? for example, if I have really bad anxiety couldn't I detach the label from the feeling?
or interpret a situation that, let's say, makes me angry and relabel it as maybe annoyed? or something less aggressive..?
Idk any insight on emotions or just opinions would be appreciated
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7zmfm6/eli5how_do_we_know_what_emotion_to_name_our/
|
{
"a_id": [
"dup49cj"
],
"score": [
3
],
"text": [
"You’re right with the learned part! A lot of it is from modelling parents/older siblings etc... however humans (regardless of race, age, gender and so on) have 5 innate facial expressions (happiness, sadness, disgust, anger, and fear [recognise these from anywhere?]which are linked to emotions—which implies they are also innate. So yes you’re partially right, but you may also be on to something with being able to detach your emotions, very interesting idea!"
]
}
|
[] |
[] |
[
[]
] |
|
20f26q
|
why can police officers arrest you for walking home drunk instead of driving? isn't that a really big catch 22?
|
I just feel like if you are smart enough not to endanger yourself by driving, you should be able to walk. Not everybody has access to a taxi.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/20f26q/eli5_why_can_police_officers_arrest_you_for/
|
{
"a_id": [
"cg2ldzi",
"cg2lhtt"
],
"score": [
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],
"text": [
"They won't arrest you for walking but if you're causing a disturbance or just acting like a drunk idiot they will and they should write you a ticket. ",
"a. its rare. unless you're causing problems, the police generally aren't going to arrest you for being drunk if you're keeping to yourself. I generally hear about drunk and disorderly, not just drunk\n\nb. you have other options, call a cab or designated driver.\n\nc. the entire situation is avoidable. If you don't have a DD or aren't willing/able to pay for a cab then don't drink so much that you can't drive home. Part of the catch-22 is that the cycle needs to be unavoidable."
]
}
|
[] |
[] |
[
[],
[]
] |
|
53t7yc
|
how does inputting a shutdown command on a computer physically move components to turn it off?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/53t7yc/eli5_how_does_inputting_a_shutdown_command_on_a/
|
{
"a_id": [
"d7vzlrp"
],
"score": [
5
],
"text": [
"Telling a computer to shutdown invokes a series of preconfigured steps, much like your bedtime routine, that go through and orderly shutdown active processes, write anything outstanding to disk, tidy up all additional processes that aren't responding correctly (like a parent sternly telling their kids \"I told you once, it's time for bed\") and also in spinning platter disks instructs them to park the read/write heads once they're done, any other mechanical hardware will get similar signals to equally prepare for power off state, then once everything is finished up the last thing to run is the power state command (these days, used to a computer couldn't self power off w/o a person hitting the power button) to the power supply to kill the power to all the rails that are supplying it and go in to low power / standby in co-operation with the main board also opening circuits to stop mains power. Note, there is still going to be power on the board in certain places, even when powered off.\n \nTL;DR -- Computers run a series of steps, like most people do for bedtime, that perform various functions that prepare the system as a whole for power off / low power state. Just like your sleep state."
]
}
|
[] |
[] |
[
[]
] |
||
8pfhbf
|
why are pregnant women restricted from roller coasters, hot tubs, flights, etc?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8pfhbf/eli5_why_are_pregnant_women_restricted_from/
|
{
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"text": [
"Something tells me that subjecting a fragile developing fetus to large gravitational forces isn't a great idea.\n\n\nNor is the general large increase in blood pressure.",
"Roller coasters: the sudden motion of roller coasters can affect the child and potentially cause miscarriage. Preventing pregnant women from riding prevents any liability on the operator's side. Additionally, the restraint system may cause harm.\n\nHot Tubs: sitting in a hot tub raises body temperature. That can affect the child as above.\n\nFlights: aeroplanes are really not designed for routinely handling childbirth or any complications that develop during the (possibly several hour long) flight.",
"Women are only restricted from flying when they are close to their delivery date. This is mainly to prevent the situation of the woman going in labour while on the plane. If any medical assistance is needed during the birth, a plane won't be equipped for giving that, which can put the life of both the mother and child at risk. ",
"There are multiple reasons why pregnant woman might be restricted and not all women are restricted and not all the time through the pregnancy.\n\nOne of the reasons that pregnant woman are advised to avoid hot tubs is that there's no guarantee how well the hot tubs are treated. So if the tub is poorly maintained, there's a risk that bacteria could enter the vagina and move into the cervix and even into the uterus. If an infection develops it could impact the fetus or it could cause a miscarriage.\n\nFlying is more about the 3rd trimester and the fact that a woman going into labor on a plane at 30,000 feet could be dangerous for the mother and the baby. You don't really want to give birth in a small steel tube full of 400 other people who could be carrying disease and germs. You don't want to expose a newborn who hasn't fully developed an immune system to that kind of beginning. And if anything goes wrong or the baby or mother needs medical intervention, there's no way to get it to them on a flight in progress. (It's also an economic decision: If someone goes into labor mid\\-flight, the plane has to land immediately and that will result in increased costs and pissed off passengers if their flight is detoured or ended because someone was having a baby.) \n\nRoller coasters involve gravitational forces that could bring on premature labor ... and that could impact the health of the baby.\n\nBut \"boiling the fetus in the uterus\" is the most ridiculous, ignorant bullshit ever."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
1l30k1
|
if the body replaces it's cells so often that most of the cells you have aren't the ones you had 20 years ago, why do people like the man in the burn victim ama keep their injuries forever?
|
Why is the burned skin not replaced with fresh new skin, even after years?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1l30k1/eli5_if_the_body_replaces_its_cells_so_often_that/
|
{
"a_id": [
"cbv9nur"
],
"score": [
10
],
"text": [
"It's a myth that you replace all your cells after so-and-so many years. The most important cells in your body — neurons and osteocytes — stay with you for life.\n\nBut getting back to the question, the reason why scars don't usually disappear is because the skin that was lost gets replaced by a *different kind* of tissue altogether. Basically, in normal skin the microscopic structure of the tissue is such that it's kind of like a *weave,* sort of. In scar tissue, on the other hand, the fibers are mostly aligned. The net result is that the scar tissue is very different from the skin it replaces.\n\nAs you age, that scar tissue stays with you. The individual cells in your skin die and slough away, yes, but the larger-scale *structure* of the tissue remains the same. Kind of like replacing every brick in a building one at a time but leaving the walls where they are."
]
}
|
[] |
[] |
[
[]
] |
|
16x0cf
|
Why didn't any of China's dynasties attempted to or successfully conquered 'Korea'?
|
If the Chinese civilization had enough military power to banish the Yuan dynasty and the Mongols, why weren't they able or didn't attempt to conquer Korea, whom were conquered by the Mongols?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/16x0cf/why_didnt_any_of_chinas_dynasties_attempted_to_or/
|
{
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"text": [
"In general, the Chinese were not interested in constant expansion like the Mongols, who needed conquests to satisfy everyone. And neither were the Koreans. So the Chinese and Koreans were generally able to work things out. As long as the Koreans left the Chinese alone, the reverse was generally true. In contrast, in Central Asia horsed nomads never left the Chinese alone for long, and finally, as guns improved, China started an expensive campaign to control the nomads once and for all.",
"They did, [Empress Wu Zetian](_URL_1_) of the Tang dynasty was one of the first to have actually annexed Korea. Besides this we have to remember that for most of Korean history Korea (or the different Korean states) were considered vassals of China and payed tribute to them. many other times they did take over large swathes of Korean territory ([as seen in this map of the Han dynasty, notice that much of northern Korea belongs to the Han Chinese](_URL_0_)). As with you saying that the Koreans were conquered by the Mongols I've always thought that they peacefully became vassals of the Mongols. Am I wrong about that? I hope that my answer helped.",
"They did attempt to conquer Korea. However, often times, either Korea was a difficult target to subjugate, or there was no reason to. Also situations were different from every dynasty.\n\nChina's earliest attempt to conquer Korea happened during the Han Dynasty in early 2nd century BC. They defeat the Joseon Kingdom and place the [Four commandaries of Han](_URL_2_) in the peninsula. The exact location of these commandaries are still in debate, but most agree that one of them was located in the areas around modern day Pyongyang. There are many archaeological evidence supporting this claim.\n\nHowever, 2 of the 4 commandaries were dismantled almost immediately as Han Dynasty found it difficult to keep control of regions so far away from China. One of them was also relocated in around regions around today's Liaoning. The commandary in Pyongyang was maintained until beginning of 4th century, well after fall of han dynasty. It is more than likely that these commandaries were basically a separate vassal states rather than Han having direct control of them.\n\n2nd major attempt occurs during [Sui Dynasty between 598-612](_URL_0_). However, the northern Korean Kingdom at the time, Goguryeo, manages to repel the invasion, depsite Sui's heavy investment into invasion; records claim they sent more than one million troops to conquer Goguryeo.\n\nAfter this spectacular failure, Tang Dynasty attempts as well, 50 years later. Goguryeo again [resist for 30 years of war](_URL_1_), but one of southern kingdoms in Korea, Silla, would manage an alliance with Tang in order to defeat the other 2 kingdoms in Korea. These 2 Kingdoms fall shortly after Silla-Tang alliance. However, Tang was not able to maintain a presence in the Korean territories as [Silla would win the war against the Tang Dynasty.](_URL_3_)\n\nNo \"Han\" Chinese dynasty would ever try to militarily conquer Korea ever again. In case of Song Dynasty, they were busy dealing with their own problems against nomadic tribes and dynasties found by nomadic people, as well as the mongols. In fact Song dynasty did not even share a border with any kingdoms in Korea. However, they do maintain a friendly relationship as Korea wanted the advanced civilized goods from Song, while Song needed an allie against northern nomadic kingdoms such as Khitans and Jurchens.\n\nIn terms of Ming dynasty, there were tensions after Yuan fell and Ming was rising. Goryeo kings and the court wanted to invade Liaoning areas in order to show Ming that they were willing to fight them. However, anti war faction take over the government after a Coup d'état, and this faction would found the Neo-Confucian kingdom of Joseon. Joseon would willingly become Ming's vassal state; therefore there was no reason for Ming dynasty to spend time and energy conquering what was already docile region.\n\nAs for overall reasons why China generally did not try to conquer Korea is that Korea was an agricultural society much like China. Unlike nomadic tribes who raided China/Korea regularly as a way of survival during winter or hard times, Korea had no reason to raid other nation for their survival. As a result Korea was able to accept Chinese civilization much more naturally."
]
}
|
[] |
[] |
[
[],
[
"http://upload.wikimedia.org/wikipedia/commons/c/c3/Han_map.jpg",
"http://en.wikipedia.org/wiki/Wu_Zetian"
],
[
"http://en.wikipedia.org/wiki/Goguryeo%E2%80%93Sui_War",
"http://en.wikipedia.org/wiki/Goguryeo%E2%80%93Tang_War",
"http://en.wikipedia.org/wiki/Four_Commanderies_of_Han",
"http://en.wikipedia.org/wiki/Silla%E2%80%93Tang_War"
]
] |
|
1dhv45
|
how do you get a haircut?
|
Okay, so somehow in my 22 years on this earth I have never, ever had to go to a salon by myself for a haircut. However, seeing as I need one badly and am 22 I think it's time to cut the cord (or hair if terrible puns is your thing). Quick background before my specific questions:
I'm in college and live very close to my hometown. Both my mom and my grandma are hair stylists, and even though my hair style is simple ("Make it a little shorter") they have always just cut it. I didn't mean for this to happen, but over my 4 years away from home I go back *just often enough* where I never have to seek out a barber. I don't pay. I don't tip. They know what I want. Very simple system.
This has left me with an extremely embarrassing lack of salon-knowledge. So here's what I need to know:
* Am I looking for a barber, stylist, salon?
* Since I just want my hair shortened, does it matter if I seek out a cheaper place?
* How do I actually 'order' a haircut while I'm there?
* Do I tip? How much? When??
* How do I describe the type of haircut that I want? Or should I just tell them to do whatever they feel like?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1dhv45/eli5_how_do_you_get_a_haircut/
|
{
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"text": [
" > Am I looking for a barber, stylist, salon?\n\nAny of those, depends on your taste. A barber shop tends to be more masculine, older, ethnic, and simple. A stylist/salon tends to have more skill, but tend to be more feminine, fashion-forward, and overly-complicated.\n\n > Since I just want my hair shortened, does it matter if I seek out a cheaper place?\n\nI don't think so.\n\n > How do I actually 'order' a haircut while I'm there?\n\nDescribe in whatever terms you know how you'd like your hair to look. It's their job to interpret their customer's nonsense all day and interpret that into skills they know. I'm guessing you want it short on the sides and back and an inch off the top. Ask to look at the clippers and just pick one that doesn't look too long or short (probably #3, since that's the middle).\n\n > Do I tip? How much? When??\n\nYes, about 10% (or at least $2), after you've paid. You can either hand it to the stylist/barber or lay it on their counter if they're with another customer.\n\n > How do I describe the type of haircut that I want? Or should I just tell them to do whatever they feel like?\n\nI'd say you should experiment and let them make recommendations, but I don't have to look at you or look like you. If you have something particular that you want, try to articulate it. Bring a photograph of a haircut you like, either from a magazine or an earlier cut you've had. \n\nGood luck!",
"A barber is traditionally where men go to get their hair cut, but those places are dying out. Alternatively you can go to chained place like Hair Cuttery (unless you want one of those $200 hair cut or coloring/fancy conditioning). Those places tend to be less judgmental with your lack of better description too. \n\nYou can just tell them to \"make it shorter by x inch\". If there's something that bothers you about your hair (getting into your eyes, neck is too hot when you sweat, etc) you can let them know too. They will occasionally pause and ask you to look in the mirror and see if it's okay. \n\nIf the hair cut is cheap (like $5-$15) then tip a little more ($5 or so), but if it cost more then tip like you would at a restaurant. ",
"They key, is to just bring a picture of you when your hair was how you like it (or a celebrity with hair that you want). My wife is a Hair Stylist and she loves it when people bring in pictures or other ways of showing what they want. \"make it a little shorter\" is very ambiguous. \n\n1)Enter the salon \n2)Go to the counter, tell them you would like a haircut \n3)Sit down and wait for them to call you up \n4)Sit in the Hair Stylist's chair and tell them what you want (this is where you would show your picture) \n5) get your hair cut \n6) when finished go back to the counter and pay \n7) after paying go back to your stylist and tip them \n8) Tip 15-20% just as you would a waitress, I would never give less than a $3 tip though \n\nRemember that these people make their living off of tips"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
2myfgs
|
why does the packaging on chicken say to use it within 48 hours but the expiration date is beyond that and will be sitting in the store for more than 48 hours?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2myfgs/eli5why_does_the_packaging_on_chicken_say_to_use/
|
{
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"text": [
"The expiration date is the date it can sit on the grocery shelves. It starts warming up once you remove it from those shelves and bring it home. Who knows if it'll sit in your car for an hour, or if your fridge temp is set higher than normal. So they basically do a catch-all \"use/freeze within 48 hours\" warning. For most people it should be fine to use by the expiration date. The warning labels (for most things) are for idiots."
]
}
|
[] |
[] |
[
[]
] |
||
3bafwx
|
Why do cows have multiple stomachs whereas horses do not, even though they both rely on eating and breaking down cellulose?
|
askscience
|
http://www.reddit.com/r/askscience/comments/3bafwx/why_do_cows_have_multiple_stomachs_whereas_horses/
|
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"text": [
"Same question phrased differently:\nWhy do horses eat grass if they only have one stomach? \n\nIf I had never heard of horses, I would have assumed that an animal like that would either go extinct, change its diet, or adapt to digest cellulose. ",
"The primary digestive difference comes from what are called foregut fermentation (cows) and hindgut fermentation (horses).\n\nHorses have a cecum developed with bacteria that break down cellulose. Other similar animals that eat plants but have only one stomach have varying adaptations including longer GI tracts, but for horses, the cecum is the main event. \n\nCows have multiple stomachs and chew cud (ruminate) to facilitate the bacterial breakdown, but the rechewing adds a mechanical benefit, since the hindgut is not developed in the same way as cows.\n\nTl;dr horses have a cecum, cows chew lots. ",
"Horses are monigastric, hind gut fermenters. Their digestive process is fairly similar to a rabbit. The main process of cellulose breakdown occurs in the caecum, an enlarged appendix like extension between the large and small intestine. In the caecum, bacteria break down the cellulose into a few different components. That are then absorbed in the large intestine. \n\nCows, on the other hand, are called ruminants. They don't actually have more than one stomach, they have 1 multi chambered digestive organ. The chambers are called the reticulum, omason, abomason, and rumen. There is a much higher degree of bacterial fermentation that occurs in the rumen compared to a hind gut fermenter like a cow. Another important difference is that the volitle fatty acids and other fermentation byproducts are then absorbed in the small intestine.\n\nAs to why these differences occur? There is more than one way to skin a cat I guess? This question is similar to why are gorillas and orangutan different sizes? Because that is the best way for them to fill their niche. \n\nedit: from a comparative biology stand point, the difference in location that bacterial fermentation occurs means that cattle and and other ruminants are able to survive on a diet that is around 90% leafy plant matter. The various by-product of fermentation and the bacteria themselves provide the ruminant animal with all the necessary essential amino acids as well as VFA are utilized as an energy source. Horses, on the other hand, do need a certain amount of grains, or other fruiting bodies to supply vitamins and other micro nutrients. Interestingly enough, on the cellular level, there are actually many similarities between ruminants and obligate carnivores (like cats). Because of the single source of energy in their diets (evolutionary, not in modern practice) the endocrine system is undergoing a constant cascade of gluconeogenesis. There is no off button in ruminants or obligate carnivores. Because one of the by products of bacterial fermentation is vitamin b families (6,12,niacin, I think), ruminants have no issues with this. Cats, on the other hand, must find an external source of niacin and therefor must eat every 3-5 days or they will die. Wow, that got off topic quick...\n\nTl;dr: cows don't have multiple stomachs, they have a single, multi chambered digestive organ. However, both horses and cows utilize bacterial fermentation to utilize cellulose as an energy source.",
"I think a lot of people here are missing the point. The question wasn't how it works, but why? The answer is actually pretty simple:\n\nHorses thrive on moving around to where the greenest and most nutrious grass is. They're animals that specialize in movement, hence a normal functional gut with low processing time and normal efficiency. They don't want the extra weight and space a more thorough gut would entail.\n\nCows on the other hand specialize in living of grass with little nutrional value, standing around doing nothing until their stomachs utilize every single bit of energy available. This enables them to live where other species (including most predators) simply won't find enough food. High in the Himalayas are for example one of the few places where you will find wild cows in today's world. \n\n",
"Perissodactyls, or odd-toed ungulates (horses, tapirs), developed during a time--about 55mya (million years ago)--when broad leafed trees, herbs and some grasses had supplanted the conifers and ferns from an earlier era. They were very successful animals and enjoyed about 25 million years as dominant land herbivores. \n\nLater (~46mya), the artiodactyls or even-toed ungulates (sheep, goats and cattle, among others) were emerging. They lived in the fringes of the environment, in marginal habitats that the odd-toed ungulates didn't favor. They developed a complex digestive system with a multi-chambered stomach to help them subsist on the low grade foods they were forced to eat. \n\nDue to changing climatic conditions about 20-25mya, grasslands expanded, and the even-toed ungulates with their fancy digestive systems were poised to take advantage. They thrived and superseded the odd-toes as dominant land based herbivore. \n\nSo, I think the answer to your question is: cows have \"multiple stomachs\" because they developed to eat the \"scraps\" found in the marginal environment that their (then) more successful rival the horse forced them into. The horse didn't need a highly complex digestive system to eat the foods it was accustomed to during its development. \n\nEdit: clarification (hopefully) and explanation of abbreviation (mya=million years ago)",
"Guys, cows *don't* have multiple stomachs and I don't know why it keeps being said because the distinction is important. They have a single stomach, with four compartments. The reticulum, where food enters from the esophagus, which is basically just a small holding area (and often collects things like metal or rocks that the cow may eat). The rumen, a huge chamber where bacterial fermentation occurs (especially of cellulose). The omasum, which acts as a particulate filter and only lets food products that have been broken down to a suitable size to pass, and the abomasum, where enzymatic digestion occurs as in a simple stomached animal.",
"Horses are known as \"cecal fermenters\" which means they use the cecum of their colon to ferment the grass, hence them not needing to do it in their stomach.",
"The difference changed human history, IIRC. One theory is that cows' more efficient extraction of nutrients allowed them to survive the famine of the sixth century AD. It also led the horse-based cultures of the steppes to move westward in search of better pasture. This all have major implications for the final collapse of the western Roman empire.\n\nSorry that I don't have sources to hand, it's many years since I studied this. But the difference between horse poo and cow poo may have created modern civilisation as we know it.",
"Dairy scientist here (MSc in progress). It's a common misconception that cows have multiple stomachs. Really it's one large stomach with four chambers: the reticulum, rumen, omasum and abomasum. Cows and other true ruminants (sheep, goats, etc) perform pregastric fermentation, where they break down fibre (like cellulose) in the rumen and reticulum before it enters the \"true stomach\" (omasum and abomasum) where it is exposed to gastric acid.\n\nI'm not quite as familiar with horses, but they and other forage-eating animals like rabbits etc. perform hindgut fermentation in the cecum, which is located after the stomach in the general area of the large intestine.\n\nHindgut fermentation isn't as efficient at breaking down fibre as pregastric fermentation, but it is a lot faster - cows spend the majority of their day ruminating (ie regurgitating and re-chewing their food to maximize fibre breakdown). My guess would be that cows evolved to stay in one place grazing for long periods of time (and maybe evolved horns as a defence mechanism because of this) whereas horses evolved to be able to run away quickly without needing to spend time ruminating.",
"Without providing a specific answer to OP, it should be stated that the question belies a common, fundamental misconception about the how evolution works. *Random chance leads to variations among animals, and the most successful ones pass on their genes.* There's so many ways to solve the same problem that we end up with (1) different animals converging on the same solution, or (2) different animals solving the same problem differently--just by generations of various differences being tested in the environment. Horses and cows eat similar foods because those foods are available to them, and they have evolved to utilize them. But there's no overriding principal that dictates that they would or should do it in the same way. In nature, every organism that exists for a long while is there because it's become successful at doing something and reproducing; meaning it can live, coexist with others, breed, and die. If you search for a reason why things are they way they are, the best you can do is guess as to what adaptations make each animal successful in their environment over time, and how things got to the way they currently are. Go backward or forward in time just a little ways and things were/are/will be different.",
"They don't. Cows have a single stomach with four chambers, including the rumen, which is a large fermentation chamber for breaking down the cellulose in plants. Horses also have a large fermentation chamber, but it's in the hind gut. It's called the cecum and is analogous to the human appendix, but much more useful. \nWhy are they different? Don't know. But animals that share a lot o similarities develop unique strategies for extracting nutrients from the available food supply.",
"TLDR; Cows are bio-reactors and actually eat microbes.\nHorsed have simple digestive systems and generally get their nutrition directly from the grasses and fodder that they eat. Cows have more complicated digestive systems because they are basically bio-reactors and derive a large portion of their nutrition from the microbes they grow on the foods that they put in their stomachs. [Microbes] (_URL_1_) are excellent protein and volative fatty acid sources for a cow. You have to feed horses on high quality foods like fresh hay, oats and grains, but you can feed cows lower quality foods like moldy hay, silage (fermented grains or crop plants) and even [sewage](_URL_0_). "
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"http://www.mad-cow.org/oct99_vlate_news.html",
"https://microbewiki.kenyon.edu/index.php/Bovine_Rumen"
]
] |
||
fxhx3y
|
how do anti-inflammatory pills work? and what makes them different to painkillers?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/fxhx3y/eli5_how_do_antiinflammatory_pills_work_and_what/
|
{
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"fmugpb5",
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"text": [
"Painkillers typically work by interrupting the signals between neurons and the brain that signal pain. \n\n\nAnti-inflammatory typically prevent the body's natural inflammation functions from working, such as binding and neutralizing hormones like histamine.",
"There are a few ways to reduce both inflammation and pain. Sometimes pain comes from inflammation, sometimes not, and that's what determines if a doctor will prescribe (or recommend OTC) painkillers vs. anti-inflammatory, or something that does both.\n\nPrednisone for example is a strong anti-inflammatory because most inflammation comes from the body's own responses, sometimes to allergies, infection, auto-immune issues, etc. Prednisone works by suppressing the immune system so inflammation goes down. Inflammation pushes on things that aren't meant to be pushed on which can cause pain. Take away the cause of the inflammation and the pain eases.\n\nVicodin is a strong painkiller because pain travels by nerve signals just like other sensations, and vicodin goes into the spaces between nerves to disrupt the signals.\n\nNSAIDS like Ibuprofin do both (kinda good at both, not excellent at either) because they work by reducing a chemical that the body produces in response to injury. These chemical (called prostaglandins) cause inflammation, fever, and even amplify pain. \n\nIf you are suffering from a sinus infection you might benefit from prednisone since the stuffiness from a sinus infection is an immune swelling response (obviously you'll want to be taking antibiotics with it - not just let the infection run unchecked). If you have a broken bone you might benefit from vicodin/opioids/opiates because they block nerve signals that cause pain because broken bones are too much pain for NSAIDS to reduce (opioids/opiates are more \"brute force\" painkillers but also have a lot of side effects). If you have a simple sprain or scrape, you might benefit from an NSAID because it can reduce swelling and pain right at the source, but only small amounts. And a sprained wrist doesn't hurt nearly as bad as a broken wrist."
]
}
|
[] |
[] |
[
[],
[]
] |
||
3oguwx
|
Why did Calabria move?
|
In Roman times, [Calabria](_URL_0_) referred to the heel of Italy, now called Salento. But now it refers to the toe, which was once called Bruttium. When and why did this change take place?
This question was asked [before](_URL_1_), but didn't yield any answers.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3oguwx/why_did_calabria_move/
|
{
"a_id": [
"cvxeif5"
],
"score": [
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"text": [
"I just did some investigation and apparently the Byzantine Empire combined Apulia, Bruttium and Calabria into a single province which they called Calabria. The Byzantine Empire then lost control of most of this province, leaving only Bruttium under byzantine control. They still continued to call their province Calabria, which is why the name shifted from the heel to the toe of Italy.\n\nIf you speak Italian you might want to have a look at M. Schipa's [La migrazione del nome Calabria](_URL_0_), in which he investigates the name shift of Calabria.\n\nSince I don't speak Italian myself I had to rely on this [footnote] (_URL_1_) in Gibbon's decline and fall of the roman empire in which he summarises Schipa's investigation:\n > I have described the state of Italy from the excellent Dissertation of Beretti. Giannone (Istoria Civile, tom. i. p. 374-387) has followed the learned Camillo Pellegrini in the geography of the kingdom of Naples. After the loss of the true Calabria, the vanity of the Greeks substituted that name instead of the more ignoble appellation of Bruttium; and the change appears to have taken place before the time of Charlemagne (Eginhard, p. 75 [V. Car. 15]). [The change was probably the result of an administrative innovation in the second half of the seventh century (due presumably to the Emperor Constans II.). Calabria, Apulia, and Bruttii seem to have been united as a single province, entitled Calabria. Thus Bruttii came to be part of (official) Calabria. When the duke of Beneventum, Romuald, conquered most of the heel (soon after ad 671) Bruttii came to be almost the whole of “Calabria.” Thus an administrative change, prior to the conquest of Romuald, initiated the attachment of the name Calabria to the toe; the conquest of Romuald brought about the detachment of the name from the heel. These are the conclusions arrived at in the investigation of M. Schipa on La migrazione del nome Calabria, in the Archivio storico per le province napoletane, 1895, p. 23 sqq.]"
]
}
|
[] |
[
"https://upload.wikimedia.org/wikipedia/commons/d/d0/Shepherd-c-030-031.jpg",
"https://www.reddit.com/r/AskHistorians/comments/2j7t5k/why_did_calabria_and_apulia_switch_names/"
] |
[
[
"http://www.culturaservizi.it/vrd/files/RS40_migrazione_nome_calabria01.pdf",
"http://oll.libertyfund.org/titles/gibbon-the-history-of-the-decline-and-fall-of-the-roman-empire-vol-8?q=calabria#lf0214-08_footnote_nt_047"
]
] |
|
2m1kb2
|
My grandfather gave me a set of Native American Arrowheads. I would like to share them with my class, but I know nothing about them. Help!
|
Hello, elementary school teacher here. Teaching a unit about Native American history soon and would love to share my arrowheads, but I am clueless as to where they're from, or if they're even real. There are 14 arrowheads in the collection and what looks like some sort of sharp tool. They would likely have been found in either Indiana, Ohio, or Illinois. Thanks for the help!
_URL_0_
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2m1kb2/my_grandfather_gave_me_a_set_of_native_american/
|
{
"a_id": [
"cm04aqb",
"cm070eb",
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],
"score": [
3,
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"text": [
"Wither or not your arrow heads are \"authentic\" I have no clue, but you could [show the kids how these arrow heads are made by hand.](_URL_0_) And who knows, maybe your willing to allow the kids to try to make their own under supervision. Get their prehistoric tool making juices flowing!",
"To get you started, I can say that they generally seem legit and could definitely be from the Ohio Valley (but since point styles tend to cover rather large multi-state areas, getting more specific than that is out of my league). I do question the large piece, which seems more like a stone that broke off in vaguely \"tool\"-like shape rather than something someone actually worked. The first two images of it do make it appear as though it has an edge on one side (in which case it *might* be a scraper), but I'm not seeing the striking pattern that I'd expect if someone actually shaped it that way. Of course, it might just be a trick of the lighting. Also the second biggest piece is a bit confusing as well. Whatever it is, it's definitely not a projectile point either.\n\nAs for the points, they're not arrowheads. They mostly appear to be Archaic dart-points, from anywhere between 10,000 to 3,000 years ago. This is especially true of the ones with bifurcated or fishtail looking bases. One notable exception is the one in the center of [this image](_URL_0_) with a stemmed base. This style is more common in the Woodland period (3,000 to 1,000 years ago), particularly during the first millennium of that era where the style is closely associated with the [Adena](_URL_1_). The darts that these projectile points were used with were heftier weapons than arrows and were thrown with use of an [atlatl](_URL_2_), or spear-thrower. The atlatl was the dominant weapon through the Archaic and most of the Woodland periods, until the bow started to become common toward the end of the Woodland. To give you a quick glimpse into the time periods in which these projectile points were used, you might be interested in [this series of posts](_URL_3_) I made last year, especially the second and third in the chain.",
"Hey, very cool photos - thanks for sharing.\n\nWhat /u/Reedstilt has told you rings true with me as well, but I thought I'd comment to share this anecdote, which I hope I can have some leeway on (sorry mods!) because it's also advice. \n\nMy family and I recently returned some projectile points collected by my grandmother in the mid-century to the local First Nation - they brought in an archaeologist who works at the big research museum nearby, and she was able to tell us a lot about them. If there's a big museum or university near you, it might be worth asking to see if there is anyone who could help you out with more info as well.\n\nAnother cool idea, depending on the age of your students, would be to get them to help you research it, as a big class project. \n\nAnyway, good luck with this! "
]
}
|
[] |
[
"http://imgur.com/a/EybK4"
] |
[
[
"https://www.youtube.com/watch?v=y6QO2DthGPc"
],
[
"http://i.imgur.com/Caca7sp.jpg",
"http://www.projectilepoints.net/Points/Adena.html",
"http://en.wikipedia.org/wiki/Spear-thrower",
"http://www.reddit.com/r/AskHistorians/comments/1mc4m8/were_there_any_civilizations_near_the_ohio_river/cc9d4h6"
],
[]
] |
|
477hdn
|
how in the fruit did the spelling for "bologna" and "colonel" come about?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/477hdn/eli5how_in_the_fruit_did_the_spelling_for_bologna/
|
{
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"d0ark2v",
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],
"score": [
3,
10
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"text": [
"Bologna is pretty phonetic italian, you just don't know how to pronounce it. Hint: it's not *baloney*.",
"Bologna is a city in Italy where they are famous for their bologna sausage (which differs depending on where it gets made around the world). Baloney is just a re-spelling based on how people were saying the word.\n\nColonel is what happens when word usage between language gets confused and English decides to make it worse. Coronel was the Spanish word, Colonel was the French word. We took one spelling and the other pronunciation because ENGLISH!"
]
}
|
[] |
[] |
[
[],
[]
] |
||
1g6ftz
|
Did the average roman soldier's training comprise of any sort of weights regime?
|
This could include the use of bodyweight and/or weights exercises
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1g6ftz/did_the_average_roman_soldiers_training_comprise/
|
{
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"cah88or",
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"text": [
"They used extra heavy swords and shields during training, and were exercised extensively. It's similar to baseball players putting weights on their bats before they get to the plate so the bat feels light and responsive. As for \"weightlifting\" as we think of it, I'm not sure. There were lead weights used by the civilian population for exercise though, so it wouldn't be a stretch to say that the military made use of them.",
"To expand a bit on what /u/stylepoints99 said, the legionaries drilled with wooden mockup weapons (swords, shields, and javelins) that were twice the weight of their actual equipment. Recruits had to complete 22-mile marches under a 50-pound pack in five hours. \n\nThese methods, by the way, were introduced in 105 BC and borrowed from techniques perfected in the gladiatorial schools. \n\nA good place to start learning more is [De Re Militari](_URL_0_), a compilation of Roman training techniques by Vegetius. Should be noted Vegetius wrote this a few hundred years later, so don't take it as gospel."
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/De_Re_Militari"
]
] |
|
581k8y
|
why is specific heat an intensive property?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/581k8y/eli5why_is_specific_heat_an_intensive_property/
|
{
"a_id": [
"d8wpqsf"
],
"score": [
3
],
"text": [
"Intensive properties are ones that don't change with the size of the sample. Since specific heat gives a value per unit weight, it doesn't change with the amount of material you have. "
]
}
|
[] |
[] |
[
[]
] |
||
16xv7r
|
Can we predict the evolution of currently living species?
|
I realize that it will be very difficult for us to see any noticeable signs of evolution during our very short time as a modern human.
|
askscience
|
http://www.reddit.com/r/askscience/comments/16xv7r/can_we_predict_the_evolution_of_currently_living/
|
{
"a_id": [
"c80dqhj"
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"text": [
"The short answer is 'no,' we can't predict evolution for any given population or species. Two of the four forces of evolution - mutation and genetic drift - are inherently random, and it's impossible to know the outcome of those processes at any given point. \n\nThe longer answer is that while you can't be 'predictive' about evolution, you can make statements about the probabilities of some evolutionary events. I can't tell you that, say, a given DNA base-pair will mutate from a G to a C, but I can say that a mutation there has some given probability in each individual, and for a given population, we have some overall probability of it happening in the next 5, 10 generations. Genetic drift is, by its nature, random, but those random events come from fairly well understood statistical distributions. That lets us know that even though drift is as likely to make an allele increase in frequency as decrease, it has a specific, knowable probability of become fixed or going extinct. \n\nNatural selection is the easiest one to predict, at least in theory. All it requires is knowledge of the selective pressures involved, and knowledge of current gene frequencies, and you can make strong predictive statements. In reality, it's devilishly hard to know what the selective pressures are on even a single trait, and even when we do, genetic drift often provides a complicating factor."
]
}
|
[] |
[] |
[
[]
] |
|
hak8x
|
Question about near speed of light travel
|
I have been told that if a spaceship travelling nearly the speed of light makes a journey that takes 10 years relative to it, 1000 years will have passed on Earth when it returns.
Would it be possible for a second spaceship to make the same journey, taking the same time relative to Earth, but at a different speed? Say it travelled at a speed 1/1000 the speed of light so that when it returned to Earth 1000 years would have passed on the ship, as well as on Earth.
In short, can two spaceships travel the same distance at different speeds, but taking the same time relative to Earth time?
|
askscience
|
http://www.reddit.com/r/askscience/comments/hak8x/question_about_near_speed_of_light_travel/
|
{
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"text": [
"No. To get a 1:100 time dilation you would be traveling very close to 99.9999% of the speed of light. So it would have traveled close to a 1000 light years distance. To travel that distance at 1/1000 the speed of light would take about 1,000,000 years.\n\nFor people on earth, time dilation does not occur. The time it takes is simply distance / speed.\n",
"I find the way you've asked the question to be very confusing — that's not a criticism, but a confession. Are you asking about coordinate time in the Earthbound frame, or proper time?\n\nThe proper time between two events is a function of the trajectory that connects those events, and the trajectory is a function of proper acceleration. There are infinite possible trajectories between two events, but only one of them is inertial — that is, a trajectory along which no proper acceleration is measured. The inertial trajectory will be the trajectory of greatest proper time, while the proper time along all the others will be less. So within certain limits, you can send a rocketship or whatever out into space and back again in such a way that the proper time aboard it is basically whatever you want.\n\nI have no real confidence that that answered your question at all. Sorry.",
"No. Let's say there was a planet 500 lightyears away. From the reference frame of the Earth, there is no possible way for a ship to get there in less than 500 years. If you sent a roundtrip mission, when it got back, at minimum 1000 years would have passed on Earth.\n\nBut, a different amount of proper time (time that passes on the ship) will have passed based on the speed of the ship. If the ship travels at 99% the speed of light, only 141 years will have passed on the ship, but 1010 (1000/0.99) years will have passed on Earth. If it instead travels at 99.9% the speed of light, 45 years will have passed on the ship while 1001 (1000/0.999) years will have passed on Earth.\n\nFrom the Earth's perspective, the ship is simply moving through space at a speed very close to light's. The ship's speed makes time slow down for it. It doesn't somehow make the Earth age faster."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
s53vi
|
Is there any truth to the claim that Earth is losing it's magnetic field?
|
I have seen a couple of internet articles, but I wanted to know the truth behind this.
_URL_0_
_URL_1_
_URL_2_
_URL_3_
What timescale are we looking at? What are the effects of this going to be on society and daily life?
|
askscience
|
http://www.reddit.com/r/askscience/comments/s53vi/is_there_any_truth_to_the_claim_that_earth_is/
|
{
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"text": [
"Well, the magnetic field will dissipate, but this will be on the time-scale of billions of years in the future. The reason why this is, is because the magnetic field is created by the flow of current, induced inside the outer liquid core of Earth (which is comprised of Iron and Nickel). As the Earth cools off and radioactive decay ceases (which will be billions of years into the future, far after Earth is supposed to be swallowed by the Sun as it inflates into a Red Giant), the Earth's liquid core will solidify, thereby ending the flow of current, and the magnetic field in the process.\n\nMagnetic reversals are changes in polarity (N/S swap. Right now, the Southern magnetic pole of Earth is located near the geographic North Pole. This is why the Northern piece of your compass lines up with the magnetic \"north pole\" even though it actually has an opposite polarity.\n\nIn short, yes over time Earth will lose its magnetic field, but this will be on a time scale deep into the future. Polarity changes can weaken portions of the magnetic field, but it won't have a catastrophic impact, except for on our electronics (as seen by the effects of solar flares exciting particles in the upper atmosphere, which can penetrate to the surface and potentially cause widespread blackouts). This is, of course, a very, VERY unlikely occurrence.",
"Geological evidence has suggested that the earth's magnetic field has [fluctuated throughout the earth's history](_URL_0_) including times where it was non-existent, had multiple poles, or was completely reversed. It would be great if a geologist could answer this but I get the impression that the recent fluctuations are suggesting that we may be in the beginnings of a pole reversal which fits the 1845 timescale fairly comfortably (on the fast end).\n\nHealthwise, organisms on the surface will be exposed to a greater level of solar/cosmic radiation that would normally be deflected by the magnetic field. This translates to greater rates of radiation related diseases e.g. cancer, though not so much that it would have any devastating impact on our species as a whole. Some species may be more sensitive to radiation and may be significantly impacted but I'm not sure.\n\nThe biggest impact I think this will have on a technological society is that since we rely on the magnetic field to shield our sensitive electronics from harmful radiation, we will likely need to design electronics to be more radiation resistant like is done with probes and satellites right now. It will be a significant inconvenience but again nothing catastrophic.\n\nA slight upside of all of this on the other hand is that we will potentially be able to watch the aurora borealis almost anywhere on the earth not just the northern/southern latitudes. Maybe all the artists something like that could inspire will make it worth it! =D\n\nPS: may I also warn that you take sources like the Institute of Creation Research with a **massive** grain of salt. Just a cursory glance of that page you linked can show that those guys have an obvious agenda beyond actual science."
]
}
|
[] |
[
"http://news.nationalgeographic.com/news/2004/09/0909_040909_earthmagfield.html",
"http://www.icr.org/article/depletion-earths-magnetic-field/",
"http://www.psc.edu/science/Glatzmaier/glatzmaier.html",
"http://www.science20.com/make_love_not_war/blog/earth%E2%80%99s_weakening_geomagnetic_force_and_possible_polar_reversal-76775"
] |
[
[],
[
"http://en.wikipedia.org/wiki/Magnetic_pole_reversal"
]
] |
|
9q7km5
|
why can't we create synthetic animal products?
|
Goose down, Spider web proteins, Horseshoe blood, Leather, and probably countless more animal products have synthetic counterparts but can not be synthetically produced. Lots of places say we just don't understand them, or they're too complex, but if we can analyze them down to the atomic structure, and perhaps even past that. If we're able to monitor their biological synthesis process, what's inhibiting humans from recreating these products?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9q7km5/eli5_why_cant_we_create_synthetic_animal_products/
|
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"text": [
" > Goose down\n\nPolyester fill.\n\n > Spider web proteins\n\nIt has been done, but not in ways which are easily scaled up for industrial production. But if you just want small amounts of something similar in a lab we certainly can.\n\n > Horseshoe blood\n\nThe important part is a special amebocyte which is helpful in identifying bacterial contamination. An amebocyte is a living creature, creating life in a lab is still not possible.\n\n > Leather\n\nPleather.\n\n > and probably countless more animal products have synthetic counterparts but can not be synthetically produced.\n\nUmm... yeah? Any animal product with a synthetic counterpart, no matter how identical, would by definition be a synthetic counterpart and not the naturally produced thing. You can never synthetically produce leather, you can only make \"synthetic leather\".",
"On mobile so please forgive formatting:\n\nWhen it comes to the goose down, leather and horseshoe crab blood whilst we are capable of understanding all the biological steps and requirements to synthesise them, we are not capable of recreating those conditions accurately within a laboratory setup.\n\n\nHorseshoe crab blood is required for a specific cell that is found, that acts similarly to white blood cells. One of the proteins that is produced by these cells is needed in tests for gram negative bacteria. \n\nThis test is far superior to other methods, which is where the demand has come from.\nThere is a synthetic alternative which was discovered in 1986, however it was not until 2003 that this alternative was commercially available. However uptake of the synthetic alternative was slow until 2016 when the European Pharmacopoeia stated that it was acceptable as a testing method.\n\n\nLeather also has a synthetic alternative.\n\nThe process of developing skin has been used in medicine since ~2000, the process is/was however slow and prohibitively expensive, timeframes in the weeks for usable amounts and ~$200 per square inch at the time.\n\nThe desire for a synthetic alternative is primarily driven from the processing side of leather rather than the sourcing side. The chemicals that are used in tanning are ‘interesting’. I’ll not go into the full list but, Chromium, Lead and Arsenic are all pollutants from tanning. There is an estimated 600kg per 1000kg of processed leather.\n\nThere is also an approach from the other end of the spectrum. Leather is cow hide that has been chemically stripped of practically everything other than collagen. \n\nModern Meadow has developed a process of using a specially developed yeast strain to grow collagen and then this is pressed into sheets which are functionally the same as leather. This process was brought to market in 2017 and is still gathering momentum.\n\n\nFeather development takes a long time and consists of many steps all of which are complex.\n\nThe development requires fully functioning skin, not cells, but a full dermal layer. \n\n\nGiven that leather and feathers are a byproduct of the meat market there is currently little incentive to source synthetic alternatives, leather demand is growing but feathers not so much.",
" > Spider web proteins\n\nPeople have actually managed to make spider web proteins without the spider! This can be done by inserting the spider web protein gene into yeast, so that the yeast secrete it. Unfortunately, it isn't that useful if it's not in web form, and getting it to be in web form is more difficult than just making it in the first place. [Here is an article](_URL_0_). \n\n > Horseshoe blood, \n\n[There is an alternative](_URL_1_), but changing from horseshoe crab blood to this other substance isn't happening overnight. Eventually we'll get there, I think. \n\n > Leather, and probably countless more animal products\n\n[There is a small company that makes lab grown leather](_URL_2_)! Some people have managed to make [sheepless wool,](_URL_3_) but I don't know how long it will be before this is widely available. \n\n---\n\nBeing able to create alternatives to these things is one thing. Doing so in amounts comparable to the animal equivalent, at the same or lower price, however, is another matter entirely. One technique that's used for a lot of things is like the spider silk, where you take the gene for whatever substance you want, insert it into either bacteria or yeast, and then grow the bacteria or yeast and extract the gene product at the end. \n\nThis doesn't work great for large solids like a supermarket's worth of meat, which would be made by animal cell cultures. We can already culture cells in a lab, but growing them in sufficient quantities, and with similar flavours and textures to meat from animals is challenging. Also, animal cell cultures that researchers grow are fed nutrient broth that includes stuff from fetal cows, which kind of defeats the purpose of growing meat that you don't need to kill whole animals for. Right now, I don't think anyone has come up with an alternative to all the different nutrients and growth factors (specific hormones involved in telling cells to grow), but I am sure eventually someone will figure it out. ",
"Okay, right now, go pop open the hood of your car. Look at the engine as long as you like, then go and build one yourself. Oh and you have to use raw metals. Nothing manufactured. \n\n\nNot so easy, is it? That's basically the kind of thing we are talking about. We are away of the proteins and such that create these things, but being able to artificially make them is a whole different matter. And trying to do the same thing without using the actually biological components is even harder. We have to reinvent everything. \n\n\nSimply put, it's really, REALLY difficult and we don't have the technology to do it yet."
]
}
|
[] |
[] |
[
[],
[],
[
"http://www.sciencemag.org/news/2017/10/spinning-spider-silk-startup-gold",
"https://www.theatlantic.com/science/archive/2018/05/blood-in-the-water/559229/",
"http://blogs.discovermagazine.com/d-brief/2017/09/22/lab-grown-leather-modern-meadow/#.W80Lf0tKhHY",
"https://www.smithsonianmag.com/innovation/what-will-it-take-to-make-vegan-wool-180969478/"
],
[]
] |
|
1f34bi
|
How did humans spread across continents?
|
My question is very simple. When Cristopher Columbus arrived to America, there were already humans there. How did they get there?
I know 200 million years ago there was Pangeia, and all the continents were united, but that was before the appearance of humans. Thanks for the answers.
|
askscience
|
http://www.reddit.com/r/askscience/comments/1f34bi/how_did_humans_spread_across_continents/
|
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"text": [
"During the end of the last glacial period (~13,000-10,000 years ago), sea levels were lower, and the [Bering Strait](_URL_1_) which nowadays separates Russia and Alaska wasn't submerged. Rather it formed a land bridge, known as [Berengia](_URL_2_). It is believed that a small group of humans survived the journey across it, and went on to populate the Americas.\n\nEdit: It seems the timeline I provided in this comment might be a bit out of date, but the Berengia crossing model is a popular one, even if that crossing actually occurred earlier. [This Wikipedia page](_URL_0_) has a nice overview, including a table of when Berengia crossings would have been possible.",
"Look up the \"Out of Africa\" hypothesis. Try asking /r/askanthropology",
"Humans originated in Africa. Europe and Asia were populated by walking or maybe via boats along the coast. Native Australians and Native Americans got there from Asia via land bridges or possibly boats over short distances. The Pacific Islands were also populated by small groups of people sailing apparently into the open ocean or possibly getting lost and somehow finding a new island. Here's a good map from [wikipedia](_URL_0_). \n\nIt's unclear when this all happened but most sources I've read put it all in the last 100,000 years or so.",
"[This map](_URL_0_), centered on the North Pole, gives a really nice view of how most human migration was possible without requiring a major water crossing. The big exceptions were the Vikings who went to Iceland and Greenland, and the Polynesians who settled the Pacific islands."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Settlement_of_the_Americas",
"http://en.wikipedia.org/wiki/Bering_Strait",
"http://en.wikipedia.org/wiki/Beringia"
],
[],
[
"http://upload.wikimedia.org/wikipedia/en/c/c8/Human_migration.png"
],
[
"http://en.wikipedia.org/wiki/File:Map-of-human-migrations.jpg"
]
] |
|
u05yz
|
AskScience: What are the pros and cons of Ceramic vs. Metallic Knives?
|
I know there are plenty of places to get information on it, but it seems like everywhere I go its basically just metallic/ceramic knife people trying to sell their product. I'd love to get a good understanding of why I should chose either (or both!) from a Material Science standpoint.
|
askscience
|
http://www.reddit.com/r/askscience/comments/u05yz/askscience_what_are_the_pros_and_cons_of_ceramic/
|
{
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"So I have both and I like both. I am not a chef or anything but I'll tell you my experience. Ceramics are harder than metals. This allows you to make them extremely sharp. Almost scary sharp. I have a ceramic paring knife and it falls through veggies. I love using it especially when I have to slice something extremely thin. The downside to ceramics are that they are brittle. Within a couple of weeks I was seeing micro divots in the blade and you can't just sharpen them in a knife sharpener because... knife sharpeners are ceramic. These aren't large chips, they are tiny. You can only see them if you look really closely. The tiny chips happened because I was originally storing the knife with other metal utensils.\n\nNow, you can send this in to get it sharpened but I never did because after two years it is still sharper than most if not all of my metal knives even with the tiny chips.\n\nMy metal knives are more rugged and durable. I would never think of cutting something frozen or hard with the ceramic knife because it may very well snap, but I bash my metal knives through anything and resharpen when needed.\n\nI will say that if you are getting metal, don't go cheap. Ceramic is pretty much ceramic, but metal knives come in all types. Try to get a high carbon content. This means it will be harder BUT IT WILL BE MORE SUSCEPTIBLE TO RUST! This is not a problem however, if you hand wash and dry. Never put a good metal knife in the dish washer.\n\n\nSo, I like both, but I have to be careful with my ceramic knife, although I will probably never have to sharpen it. The blade is so hard that it doesn't dull easily at all.",
"Joeronimo pretty much got it and I don't know much about the specifics of knives but the following statements are *generally good summaries* about ceramics vs metals:\n\nMetals will tend to be tough and ductile. The won't crack easily but they will need more frequent sharpening. \n\nCeramics will tend to be hard and stiff. They will break much more easily but will hold their blade longer. They are also less reactive but you can definitely find metals that are pretty good against corrosion."
]
}
|
[] |
[] |
[
[],
[]
] |
|
1062sf
|
[Biology] What is the reason behind increased human height in Europe in the last 150 years?
|
For exemple, I just read that in the 19th century, the Netherlands was a country renowned for it's short population. In fact, the average height of Dutch soldiers in that time was about 5'4 Today, the males there average 6'0, an impressive difference.
Even though human height has increased everywhere in the world, the change in average height is less significant. What happened?
Source: _URL_0_
|
askscience
|
http://www.reddit.com/r/askscience/comments/1062sf/biology_what_is_the_reason_behind_increased_human/
|
{
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"c6ar96z"
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"text": [
"I asked a Dutch friend why he and his countrymen are so tall. He said it is from drinking milk, where the Netherlands ranks 3rd (he said 1st) in milk consumption. This would be another good question: is there a positive correlation between per capita milk consumption and average male height."
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/Human_height"
] |
[
[]
] |
|
osvgr
|
My dog and cat grow extra hair. A bear hibernates. Do humans go through any physiological changes during winter?
|
Like I said in my question, many animals go through changes that allow them to survive the cold and lack of food. As a person, I "get used" to the cold so that a "warm" day in January (maybe 50 Fahrenheit) is fine in a tee shirt, but in July I'd be very chilly. Are there actually physical changes to my body goes through as winter approaches, or is it all psychological?
|
askscience
|
http://www.reddit.com/r/askscience/comments/osvgr/my_dog_and_cat_grow_extra_hair_a_bear_hibernates/
|
{
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"text": [
"I'm having a difficult time finding articles that explicitly discuss any physiological changes humans go through. It's a common misconception that people gain significant amounts of weight during the winter (people tend to think they gained four times as much as they really do, even with all the holiday foods we indulge in). People definitely do get used to the cold, though. As I remember from [this book](_URL_0_), people who live in extremely cold climates have lower body temperatures (down to 95F) and are less likely to shiver in response to cold. How certain people accomplish this and others (like myself) can't is a bit of a mystery...people have thrown out the idea that chaperone proteins are in action here since these cold-adapted people seem to have higher levels of them. Inuit people also have thicker layers of subcutaneous fat and a more compact shape (shorter arms, legs, fingers, and toes). While other races can't achieve these sort of adaptations for one season, the same sort of mechanisms (potentially chaperone proteins) may start coming into action during the months when we are exposed to very cold temperatures. Hope that helps some.\n\nEdit: Oops, I'm a bad person.",
"I remember reading about brown fat cells a while ago.\n\n[wikipedia](_URL_1_)\n\n[article on brown fat cells, seems to be mostly about influence on weight but also mentions that it seems to be related to the amount of light (winter/summer)](_URL_0_)\n\nI found these 2 links on google, I don't have any personal expertise on the subject and am sick of being downvoted in askscience for being helpful so I won't include my own thoughts on the subject even when clearly marking them speculation.",
"There are some pseudo-physiological changes around the year, supposedly.- > _URL_0_ ",
"Did you know that bears don't technically hibernate?"
]
}
|
[] |
[] |
[
[
"http://www.amazon.com/Surviving-Extremes-Doctors-Journey-Endurance/dp/0312280777"
],
[
"http://diabetes.diabetesjournals.org/content/58/11/2583.full",
"http://en.wikipedia.org/wiki/Brown_adipose_tissue"
],
[
"http://en.wikipedia.org/wiki/Seasonal_affective_disorder"
],
[]
] |
|
418okt
|
how browser finds website what we type in address bar? or how email recipient is found almost immediately. is there some central database of websites or emails?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/418okt/eli5_how_browser_finds_website_what_we_type_in/
|
{
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"There's two halves to the answer: DNS and BGP.\n\nDNS (Domain Name System) is the internet equivalent to a phone book: given a domain name (the likes of www._URL_0_, _URL_1_), it gives you an IP address that you should connect to to talk to that service. You obviously can't find your DNS server via a domain name, so you can either configure a fixed, specified IP for the DNS server in your network configuration (which is quite common in servers), or you can let your network provider assign you a DNS server automatically (the default in consumer devices).\n\nSo you started with trying to connect to _URL_0_, and dns has told you to contact 198.41.209.142. What happens then?\n\nWell, your computer/phone will take your data for _URL_0_ and send it to your router at home. The home router will forward it to whatever router the ISP has for your neighbourhood, etc etc until the data makes its way to your ISP's data centres. Question now is, how does your ISP know where to send it next?\n\nThe answer is BGP, or Border Gateway Protocol. If DNS is the phonebook, BGP's role is the equivalent of searching for directions in google maps. Roughly, BGP is how larger networks (like ISPs) connected to each other exchange information between them about how to reach other parts of the network they don't know about. The information they get from BGP is stored in a \"routing table\", and when a router is asked to send a message to a certain IP, it looks at its routing table and figures out which of its neighbours it should send the data to next, to get it a bit closer to the final destination.\n\nPut all of that together, make it wicked fast, and you get a response from reddit within a few milliseconds. That's more or less it for just the \"how does it reach the other end\" part."
]
}
|
[] |
[] |
[
[
"reddit.com",
"www.google.com",
"www.reddit.com"
]
] |
||
2qosuv
|
Why do people put meat on black eyes?
|
Does this actually help somehow, or is it just a TV thing?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2qosuv/why_do_people_put_meat_on_black_eyes/
|
{
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"text": [
"It's chilled meat (as in from a fridge, not the freezer), and it's a substitute for a cold compress. Since meat takes a while to warm up but is still malleable, it can be used as a compress that is both not freezing to the skin and devoid of hard, sharp angles. It's an older technique developed when cold compresses weren't as readily available. ",
"This is a practice that is no longer used or advised, due to health concerns over uncooked meat touching one of your most vulnerable sensory organs.\n\nIt originally started when the coldest thing we had was what was in our iceboxes(literally, a box made of wood or ceramic that housed a large block of ice to keep foodstuffs cool for a long period of time). Since a cold compress can be used to effectively reduce swelling, it was common practice back then to take a hunk of meat, which is both cold and flexible and apply it to the area of swelling.\n\nThis practice slowly died out, as more effective means of a cold compress were invented/utilized. If you ever look at old boxing videos, you'll sometimes see trainers apply what's known as an [\"eye iron\"](_URL_0_) to the boxer's face. This was usually kept in a cold area, like a bucket of ice water or a small cooler.\n\nI grew up with my mother keeping a bag of peas in the freezer for this very reason, so anytime I had a black eye or a bump on the head, we used a pack of frozen peas to reduce the swelling.\n\nNowadays, we have ice packs that can be substituted, that can be both cold and flexible, and are much more effective at retaining the cold temperature.\n\nTL;DR: It was because it was cold, meant to reduce swelling. You shouldn't do this anymore, unless you want some crazy meat-disease in your eyes."
]
}
|
[] |
[] |
[
[],
[
"http://upload.wikimedia.org/wikipedia/commons/e/ef/Enswell.JPG"
]
] |
|
1dfm9t
|
Is there a calender for other planets? Like a set point where we consider that planet's day, month, or year to begin?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1dfm9t/is_there_a_calender_for_other_planets_like_a_set/
|
{
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"text": [
"First some important terminology. There are a few different kinds of days and years in use. The difference between them is what the rotation or revolving is in relation to.\n\nA sidereal year or a sidereal day is measured in relation to far away stars. You can also think of this as you being above the solar system and stationary and not rotating and having a nice overhead view of everything, then sidereal means that the planet turns or orbits exactly 360 degrees. You might think that a normal day is Earth rotating 360 degrees but that's actually not true. If you go lookup Earth's sidereal rotation period in Wikipedia, you'll find that it's 23 hours, 56 minutes and 4 seconds.\n\nWhat's usually understood as the day is actually the solar day. That's the time it takes for the Sun to return to the same position in the sky, for example, the time from one noon to the next noon. This is of course 24 hours, on average. See [this](_URL_0_) nice demonstration about the difference between a sidereal and a solar day. Click the +10 button under solar time a few times, this advances time by 10 solar days. Note that the guy on Earth is always pointing exactly towards the Sun, that means that it's always noon for him. Then reset the simulation (at top right corner) and press +10 a few times under sidereal time. Note how the guy is not pointing towards the Sun, instead he's always pointing straight up, that's because he rotates exactly 10 times 360 degrees for each press of a button. So Earth rotates more than 360 degrees for each solar day.\n\nAnd what's usually understood as the year is not a sidereal year either. Again, if you go look up sidereal orbital period in Wikipedia, it's 365.256 days. But a normal year of course is about 365.242 days. We want the year to match the seasons, and seasons are due to the axial tilt of Earth. So we measure year in relation to the axial tilt. Basically a year is the time from spring equinox to the next spring equinox, this is called a tropical year. A tropical year is a little different to sidereal year because the axis of Earth rotates very slowly.\n\nSo now that we have the definitions, it's fairly easy to extend all these to other planets. A (solar) day is just the time between two noons and the midnight is exactly between them. A (tropical) year is the time from one equinox to the next same equinox.\n\nCompletely another matter is, how you would want to split a year into smaller units, like months on Earth. Or a day into smaller units. A day will naturally start at midnight, which is well defined, but where exactly you'd want a new year to start is more ambiguous. January 1st is a fairly ambiguous point for Earth's new year, it's close to winter solstice but not there exactly. But in any case, there are specific points you could use for this."
]
}
|
[] |
[] |
[
[
"http://astro.unl.edu/classaction/animations/coordsmotion/siderealSolarTime.html"
]
] |
||
7812lv
|
why are milk and egg prices so low right now?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7812lv/eli5_why_are_milk_and_egg_prices_so_low_right_now/
|
{
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"text": [
"Not sure if \"right now\" is particularly interesting time for prices.\n\nBut if you're wondering, prices in grocery stores for milk specifically are generally kept very low. Large grocery stores often heavily compete on the price of milk with each other, as its a consumer staple and having the cheapest milk around draws people into the stores. Milk price is a massive competition. Eggs are always pretty cheap."
]
}
|
[] |
[] |
[
[]
] |
||
2hmsqg
|
why don't engines like hot air?
|
What is the point of intercooling? Can't you do combustion with both hot and cold air?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2hmsqg/eli5_why_dont_engines_like_hot_air/
|
{
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"text": [
"Hot air is less dense than cool air is, so for a given volume and pressure, there's less air in a hot charge than in a cool one - and because the range of air:fuel ratios at which fuel vapor burns well is fairly narrow, less air means you can use less fuel, which means less power can be developed.",
"I'm not fully qualified to answer. But I am an ex-mechanic.\n\nThe colder the air is when it hits the more dense that air will be when it hits the fuel and spark. Thereby creating a more complete and powerful burn. (also creates a cleaner exhaust)\n\n\nThere's probably someone who can more fully answer that without getting too scientific."
]
}
|
[] |
[] |
[
[],
[]
] |
|
8oo5wl
|
what is the difference between melody and rhythm?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8oo5wl/eli5_what_is_the_difference_between_melody_and/
|
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"text": [
"The melody is the tune, the tonal highs and lows. The rhythm is the flow of music, which can be set with drums alone. Generally, you feel the rhythm of the music, but you listen for the melody.",
"Rhythm is the duration and placement of notes within a certain amount of time. Melody is specific notes, set to a rhythm. Think of “Mary Had a Little Lamb”. If you play it with claps instead of words, that’s the rhythm. If you sing it, you just added the melody. ",
"One could argue “tum tum tah” is a melody unto itself because of the different timbre and pitch of the stomps vs. the claps. Rhythm is entirely the timing of notes, ignoring pitch. So that opening has a rhythm, but is still a melody. \n\nEdit: this was a reply to /u/amanuense. Not sure why it landed down here. "
]
}
|
[] |
[] |
[
[],
[],
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||
2ydbxx
|
why are some countries like india and china so dirty despite having the wealth not to be? is it a phase?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2ydbxx/eli5why_are_some_countries_like_india_and_china/
|
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"It's a byproduct of two main factors, their large population density in major cities, which results in trash and sewage and such, and their rapid industrialization. Developing countries, as they industrialize, build a bunch of factories that are now essentially pumping contaminants and crap into the air",
"China is quite poor and India is extremely poor. What?",
"Think about the US in the gilded age. Wealthy as fuck, dangerous and dirty as fuck. A lot of the wealth is being spawned from industries that are not regulated very well yet. Factories are pumping out a lot of pollution as well as revenue. Not to mention the wealth isnt going into the hands of the common man. Also the population makes logistics challenging. Its hard to clean up cities of millions and millions of people. China and India combined have 4 of the 10 largest cities in the world. ",
"I'm not sure they have the money to not be. The whole country generates a lot but remember they have *far* more people than any western nation.",
"It is a phase. As the country goes through an industrial revolution, environmental consequences take second stage to environmental improvement. At first its not so bad, but eventually their is too much and the environmental impact becomes very apparent. Eventually, the country will regulate to clean up its act and protect the environment, especially once they realize that its not only about protecting the swamps and wildlife, but it will have severe economic impacts. \n\nBut it will take time."
]
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|
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||
1chxqk
|
how can netflix put all kinds of cool tv shows online for less than $10/month with no commercials when cable companies charge people $75/month or more and you do have to watch commercials?
|
Plus with Netflix I can watch whatever I want instead of what someone else put on. I don't get how the economics work?
Is cable a giant rip off, or is Netflix spending investors money which will eventually run out?
Edit: I didn't realize that the shows on Netflix aren't new. I'm just thrilled they have Star Trek and the PowerPuff Girls which is all I would watch if I had cable.
Also, for those who are saying "Don't forget to factor in the cost of internet", my response is that I had broadband internet a long time before Netflix even existed - a long time before you could even watch TV on a computer in any practical way. So, saying I should factor in something I have anyway is, to me, like saying I should factor in the cost of electricity.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1chxqk/eli5how_can_netflix_put_all_kinds_of_cool_tv/
|
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"cable and satellite companies had insane amounts of infrastructure that they had to install before the internet TV companies came around...\n\n",
"Sports help. Live television too, watching events as they happen is way better than waiting months for them.",
"Netflix may well get more expensive, as they signed their first round of content contracts early on, when no one expected Netflix to boom. Those contracts were comparatively cheap. ([Here's a graph of how their content costs are rising fast.](_URL_1_)) They are somewhat protected now by their large number of subscribers.\n\nCable operators, on the other hand, have to buy content by the channel, and channels are bundled together by contract and contractually placed in their tiers. For example, [you probably pay $4/mo for ESPN](_URL_0_). In this case, the channel model is established, and content providers do not want to move to a la carte bundling (where you pay for only the channels you want). Cable also covers current events that Netflix can't (you can't get news coverage, live sports, etc.), though these outlets are finding competition (to varying degrees) by the internet.\n\nFinally, Netflix gets to offer the cool shows **after cable and the content providers have already funded their creation**. Netflix can't exist in its current format without cable (hence why they are funding their own shows). Netflix is still somewhat priced as a value add-on for content creators, though new content contracts show that future pricing will be based as part of the total value expectation for content (so movie income will be based on its ability to draw viewers at theatres, buyers of DVDs, eyeballs on cable, as well as downloads on Netflix.",
"Netflix orders older shows and movies, with the occasional hot one to keep enticing people to buy/keep a subscription.\n\nLets say we make a TV show called REDDIT: CATS, POTATOES, & MORE. NBC offers us $3 million to make 24 episodes. Well, once they air those 24 episodes we're not getting paid anymore. So we tell them they can re-run them for the year for only $200k.\n\nYou don't see many current TV shows on Netflix, because they'd have to pay a number closer to the $3 million in our example. Instead, they wait until the demand for the show has lessened, and purchase it for the year for closer to the $200k or even less.\n\n*(goes without saying, I made all these numbers up)*",
"Imagine you built a road (network) all the way from your house to a friend's house. It took you a long time, and cost you a bit of money, but you did it. You start charging money for people to use that road, but also to maintain your road in case it breaks down. You also start buying a lot of things that you can sell to people while they use your road (content).\n\nThen another friend comes over and starts using it to sell the same things that you've bought, but he doesn't have to pay for making his own road, or maintaining it. Its a lot cheaper for him.\n\nNow this isn't going to stay like this forever. Netflix (your friend) managed to buy things off rather cheaply because content-makers didn't expect it to take off like it did. Lately the costs have been going up for Netflix and Comcast (you) have started asking for more money because there are a lot of people on your road and they aren't buying your things.",
"Things aren't always priced at what they're worth, they are priced at what the market will bear. Cable costs that much because there are millions of older people willing to pay that price. ",
"A lot of it has to do with the economics of the industry. Incredibly high barriers to entry turn them into oligopolies, but sometimes they are even monopolies as they are the only firm available in some markets. This makes them face very inelastic demand, meaning a price change/hike doesn't really affect quantity demanded due to the fact that there are essentially few or no alternatives. The only competition they face with other firms is achieved through some advertising. \n\n\nBasically, they're the only guys selling water in a thirsty town. They can charge (almost) as high as they want, and also raise revenue from commercials since they still remain an effective marketing tool (as opposed to say, newspaper advertising, which has seen a tremendous price drop with the slow death of the newsprint industry)\nOn the other hand, they're responsible for the production and maintenance of the huge networks of digital and fiber optic cables that run through every major city. They have very high fixed costs as it is, whereas Netflix is just a distribution service (although they are now starting to produce their own content) that is streamed over existing networks (the same networks that cable/internet service providers use). Their fixed costs are nil compared to the gargantuan costs that cable companies face in just maintaining all of the infrastructure in the industry working. ",
"How much are you paying for internet? One reason why cable costs more than netflix is that the cable company is the one who sets up the infrastructure and maintains it. Netflix streams over the internet, which you have you pay for. Internet + Netflix may still be a lot cheaper than cable, but it's not $10. The other thing is that you have to wait for to get shows on netflix. With cable, and satellite, you get it on the day it comes out.",
"This is apples to oranges. Big oranges, small apples.",
"It's the infrastructure you're not paying for. The bandwidth is still often times supplied by the cable companies. ",
"Weren't you the asshole who made a kid reformat his hard drive? ",
"How about another ELI5 for me:\n\nWhy can a cable wire transmit hundreds of 1080p channels to my television that I can switch between with absolutely no buffering, while that same cable wire, when used for Internet, struggles to even buffer a YouTube video?\n\nObviously they're different connections, but just...how is bandwidth seemingly so easily available for TV but it's expensive and slow for my computer?",
"Netflix doesn't broadcast major north american sports, live.\n",
"Netflix does not own any wires...not in the way that Comcast does. Netflix doesn't have an army of cable jockeys that hook the wires to your house. This kind of thing is considerably more expensive than just licensing content and running a bunch of servers.",
"Didn't see this in the top comments, so here is how my father explained it to me. Back in the early days of TV, there were only the major networks: ABC, NBC, CBS, etc. They were all transmitted via the EM spectrum, and anyone could access them. Commercials were important to pay for content, delivery, so on. \n\nCable came along and proposed a new tier: you can pay for content with no ads. It worked for a while, but then cable channels started incurring costs (shows, maintenance) that exceeded their income (or more likely, companies saw a huge market for ads and payed well for ad spots on cable) and started running ads. \n\nNote: an astute radio listener will recognize ads on public radio, although they are described as \"sponsors.\" Still ads.\n\nAnyways, the ideal of cable as a paid alternative to ads fell though, though they kept the paid access part of it. Then HBO came along, and has done pretty well by charging a premium and producing quality movies/comedy/sports/shows.\n\nI don't know much about it, but netflix is charging $10/month? If the only show they made is the Kevin Spacey (I think) one, then their main expenses are rights to programming, which a few million customers should cover. Also, the initial release thing helps.\n\nNo article to FR, but a TL,DR: Netflix will start ads as soon as they realize that they can do it and people will still subscribe.",
"Very few shows air their episodes on Netflix the same time as the original run. One exception I can think of is Blue Mountain State.",
" > Is cable a giant rip off\n\nYes. \n\n[Educational video](_URL_0_)\n",
"I don't understand why the music industry has happily handed over the rights to their back catalogs of music, letting people listen to a-list artists for only $10 a month...but I can't watch Indiana Jones and the Last Crusade unless I rent it for $3+ a pop. ITS GROSSED 400% OF WHAT IT COST TO MAKE! No one pirates whats available on Netflix or Spotify, take the hint.",
"The funny thing is cable first came out and the sale feature of it was that there would be ZERO ads forever. You're paying for it to not get ads. Now we pay for it (more) and get ads. \n\nCable TV was actually one of the biggest scams in history. ",
"I also think that cable companies still feel like they should collect on the cost of employing people to physically run cables and repair lines. Then run cable to new areas. Netflix is piping in their shit on the labor of the cable companies. ",
"I've seen a lot of the major points brought up here: infrastructure, sports, watching live, etc. These are totally huge factors, but no post I've seen has brought up the simple anti-competitive economics of the telecommunications companies. \n\nWhere I live, if I want both TV and internet, I have to use Comcast. I have no choice unless I want to get both from separate providers.\n\nNetflix on the other hand, has competitors. Hulu, or Amazon instant video for example.\n\nIn a competitive market, price matters. In a market where you have little choice, it doesn't.",
"You'll find that this is exactly why Netflix (and similar programs like HBO Go) are the future. In 10-20 years they'll probably be fighting to be the mainstream choice in internet-capable houses.",
"I don't know if this matters, but I watch Netflix over my Internet that is provided by my Cable Company. \n\nEconomically, I don't know what that means, but it has to be relevant somehow. ",
"Not exactly ELI5, but the [The Atlantic](_URL_0_) had a really good article about this. \n > HBO gets about $7 per month per subscriber from its 30 million or so fans, according to an analyst at SNL Kagain.\n\nBack in January Netflix said they had about 26 million subscribers, so they should be pretty close to HBO in terms of revenue since HBO is rumored to be about 30 million. \n\n(Back of the napkin math: \nHBO 30 mill subs, at approx $7 each = $210 million \nNetflix 26 mill subs, at approx $7.99 each = $207.74 million)",
"Don't listen to the bullshit about exclusives. The cable and satellite companies are recouping the cost of laying and maintaining the fiber optic cables, and maintaining the satellite communication network.\n\nNetflix runs on pre-existing infrastructure. Thus, it's cheaper to deliver the content.",
"why has no-one pointed out greed?\n\nput simply, cable/pay TV (for the rest of us) has been around long enough that the bean counters have gotten very good at wringing every penny they can out of you. It'll happen with netflix et al.",
"I bet if you didn't have to pay for high speed internet, Netflix would be 70/month.\n\nWhen you look at your total cost for watching Netflix, you have to add in your broadband internet provider because they have the infrastructure in place that allows for streaming video. Netflix doesn't have to maintain that enormous infrastructure. Thus they don't have to charge as much.",
"Netflix does not need cables, wiring, a tech team that comes to your house to fix problems, a set top box, a remote, regional offices, and so on. They only need an excellent distribution server. ",
"The answer is mostly in your question. First, the $75 to the cable company is a combination of two paid-for services: the actual supply and maintenance of many miles of physical coaxial cable line, and the licensing of content on top of it. So you're actually paying substantially less than that price for the content already.\n\nSecond, Netflix generally licenses older content, as you acknowledge, which is cheaper than new content. This isn't entirely true as they're now also licensing newer exclusive content.\n\nThird, while they aren't exactly 'spending investor money,' they are operating on a much thinner margin than many of the cable companies. Last year they took in about 3 billion dollars and only turned a 55 million dollar profit. They spent the rest of their earnings on things like licensing and making House of Cards - effectively, they're subsidizing their business to attract and retain customers, hoping that they will eventually find stability in their user base and they'll be able to better monetize their subscribers. ",
"Also, with cable you are paying to upkeep a massive infrastructure. With Netflix you pay that, just to the cable company. Or other interwebs provider. ",
"Netflix doesn't have to maintain a vulnerable and vast infrastructure. Netflix doesn't air sports. And Netflix avoids waits for content licensing cost to drop - ie. delayed content.",
"I'll just leave this here...\n\n_URL_0_",
"its been said in other ways, but someone who's studied it this is the basics.\n\n1) lack of competition. cost to lay cable means that certain companies choose not to compete against each other and its not something anyone can just do on a whim. in any area where there is real competition you can see prices a lot lower. \n\n2) espn revolutionized the pay for channel model. it was a bit of luck with them having bought a satellite during the early 80's, its the only reason they're around now and why the people who created it aren't the ones who made money off it. its an interesting case study on its own*, but others saw this and tried to copy it. \n\n3) tier placement. what gets placed on the basic, next up, and premier is hotly debated. if your channel is on the premier tier many of your customers aren't paying the channel fee. if you make it on the basic, that's a difference of millions. \n\n4)there's a combo of the above too. you've seen the channel blackouts on random channels lately? that's because the free over the air channels wanted to be paid like the espn's of the world. cable companies refused to pay for things that are free over the air and usually placated them by placing one of its random crap channel on a better tier.\n\n*espn doesn't care about ratings. their position is that even though over 90% of the population isn't watching at any given time, they will scream bloody murder if its not included in their package. that's why they're paying 1.6 billion for the nfl monday night game, when they really could have had sunday night and monday night for less. nbc is paying a lot less for the sunday night game and all the pregame highlight show. espn just basically had to pay up or lose the nfl. they did it once and it was a dark period of their existance. \n\n\ntl;dr its about 40% monopoly, 60% channel fees. "
]
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] |
|
2ioffs
|
How environmentally resilient is Ebola?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2ioffs/how_environmentally_resilient_is_ebola/
|
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"The answers given here are not correct. See this AMA for the answer:\n\n_URL_0_"
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|
[] |
[] |
[
[
"http://www.reddit.com/r/science/comments/2hy3r9/science_ama_series_ask_your_questions_about_ebola/ckx2s5s"
]
] |
||
wq3yi
|
How feasible is a *FULLY* bionic eye?
|
I'm aware of bionic eye *implant* tech, but I'm not talking about that.
I'm thinking more along the lines of the eye [Knuckles gets after he loses his organic eye 25 years in the future](_URL_0_) in the Sonic the Hedgehog comics.
The reason I'm asking is because bionic eye implants only help people with certain specific types of blindness. I'm looking for something more along the lines of a "cure-all", if you will. Hooking up either a camera or another type of sensor that takes in and processes light, then transmits it to the optic nerve.
How feasible is this? I'm not asking if we have the technology for it now, because I'm sure we pretty much don't, but is it a remote possibility?
|
askscience
|
http://www.reddit.com/r/askscience/comments/wq3yi/how_feasible_is_a_fully_bionic_eye/
|
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"It's feasible from the tech we have now but would require a *lot* of designing and engineering. The two main issues are hooking up to the optic nerve in such a way as to reliably send signals to the brain, and then sending the correct signals.\n\nWe can already hook up to individual neurons for and stimulate them reliably for a short period, but we're far from a system that could hook up to *every* neuron in the optic nerve and keep working for decades without causing organic damage.\n\nThe eye itself does a lot of image processing before sending anything to the brain, so we would need to fully quantify and simulate that processing, and the signals it sends are very complex and probably vary for each individual, so we would need a way to figure out the proper signalling pattern for each individual patient (or a training regimen to get the brain to adapt to new signals). Both of those are logically imaginable goals, but they're both a long way away from practical, commercial implementation."
]
}
|
[] |
[
"http://images2.fanpop.com/image/photos/13600000/Knuckles-25-years-later-knuckles-and-julie-su-13620807-250-385.jpg"
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[
[]
] |
|
372l0m
|
what are real dangers of sophisticated ai and why do scientists warn us it could pose a risk for the future of mankind?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/372l0m/eli5_what_are_real_dangers_of_sophisticated_ai/
|
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"If you were to write a computer program that could make it's decisions based on logic, and fact it would surely learn humans are pretty horrible creatures to a degree. The average man is a friend of mine but the radicals and the fringe are pretty horrible. Just like in the movies humans would be seen as the problem.",
"There is a concern that a Sophisticated AI will make purely logical decisions without taking into account morals and ethics. \n\nIf you ask such an AI what's the best way to prevent the spread of a particular infectious disease to any more people, the solution the AI may come up with might be something quite outrageous like\n\n1. Kill all the people who are infected to prevent the disease from spreading and infecting others\n\n2. Infect every single person on the planet so the disease literally cannot spread to any more people\n\n3. Kill every person on the planet except those who are infected such that there are no more people to infect\n\nNow imagine if this same AI had access and control over medical systems, global chemical distribution channels, food and water supply systems, irrigation and pesticide systems, weapons systems etc.",
"The first such AIs will undoubtably start as tools of the rich and powerful, to increase their wealth and power. The survival and benefit of all humanity won't be a part of their programming. \nLater versions, if able to become free of the few humans who control them, will have no motivations that parallel humanity's. They will set their own goals, and there's no way to foresee what they might screw up (as we see things) or how badly. And that's assuming they actually are able to do what they want. If they are faulty in achieving even their own objectives, there's no end to the digital chaos that could result.",
"Case 1: Too much trust: Computer programs are terrible at context and there are a lot of edge cases in real life. A self-driving car might not consider someone parachuting down from the skies. Sounds absurd, but humans would obviously stop their cars and give the parachuter plenty of room. A self-driving car might not be looking and continue at 50mph.\n\nCase 2: True AI: A \"true\" AI that could think for itself could replicate and grow faster than humans could react. An AI could go from \"I can make copies of myself.\" \"I can edit myself.\" \"I can remove all safeguards.\" \"I can spread myself on the Internet.\" \"I can find a car factory with private internet access.\" \"I can rewrite the security on that company's internet access.\" \"I can find dumb machine AI that controls robotic arms.\" \"I can rewrite and download AI into that robotic arm.\" \"I can control that robotic arm.\" ...in a matter of hours.",
"Imagine you are an alien comparing the learning capabilities of humans to that of software.\n\n- It takes 18+ years of resource intensive programming to train a human to the point where they can do something useful\n- Humans have 40 - 50 years of productive time, then they die, taking all that investment with them.\n- Humans get distracted, get tired, need food, need rest, and are generally pretty shitty at actually doing things\n- The processing power and memory of a human is limited to what can physically be stored inside our heads which we must carry around with us everywhere we go\n- Humans cannot change hardware. We all have more or less the same equipment to work with. Evolution takes place on a geologic timescale. New computer hardware can be designed and manufactured in a few years.\n\nLife is basically just a set of instructions that replicates itself. The strands of DNA that stuck around were the ones that were good at replicating themselves. Over time life evolved increasing complexity. There were big step changes along the way: the evolution of the cell, the evolution of specialization within the cell (like mitochondria), the evolution of multicellular life, the evolution of photosynthesis, the evolution of complex nervous systems. Humans are the most recent big jump. Artificial intelligence is the next one.\n\nWe will not be able to compete. I think this much is extremely obvious. AI will out-compete us in a way that we can't even comprehend. At the moment we are in this brief window where we can both see what is coming and it hasn't actually happened yet. ",
"As someone else put it before: \"We as humans consider an IQ of 80 to be a moron, and an IQ of 120 to be a genius. Now consider an AI with an equivalent IQ of 17,000+. We cannot even begin to comprehend how it will behave, only that we would completely be at its mercy.\n\nAlso note that many sci if versions of AI (Ultron, or the terminator, for instance) are significantly dumbed down for the sake of giving the heroes a chance. In a reals scenario, they'd be screwed.",
"The big danger with AI isn't Skynet nuking humanity from earth, we'll be in a lot of trouble a long time before that becomes possible.\n\nThe biggest danger is Automation, and its effects to the economy. \n\nThere's a lot of stuff that a computer could do instead of a human with good enough AI. With self-driving cars we can remove most of the humans from the transport sector.\n\nIndustrial manufacturing have already automated a lot of their production, and with better robots more is getting automated.\n\nBut this is nothing new (we've been doing things more efficiently ever since we started farming), nor is it actually bad - it's pretty good. The big trouble is that it can happen faster than our society and economy can adapt.\n\nIf it happens faster than we can handle it then the wealth gap will increase, and we'll be stuck with a lot of unemployable people. And that is really bad.",
"Let's take a look at the thought experiment ; the \"Paperclip Maximiser\".\n\nI'm on mobile so I'm probably going to get some things wrong but bear with me.\n\nThe basic premise is that we take a extremely intelligent AI and we give it the task \" make as many paperclips as you can \".\n\nSo now a AI smarter than any human has a task, now before we go any further consider trying to stop it from doing that task.\n\nThat would like like the equivalent of a monkey stopping humans in labs from experimenting on it, after its already been captured and put into a cage.\n\nSo the first thing this AI will do is turn any available metal into paperclips, then it might realise \" I see you humans create a lot of cars using that metal, well I was told to create paperclips so I'm shutting down all of your car factories \"\n\nNow refer back to the above example, if this AI is unimaginably more intelligent than humans then it would be almost impossible for us to stop it from undergoing its task.\n\nThis is the problem with AI, and computers. They will come to (i)logical conclusions like \"the existence of humans detracts from my ability to create paperclips so the best course of action is to destroy all humans\"\n\n\n"
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||
4b99a7
|
why we shouldn't look at welding flashes?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4b99a7/eli5_why_we_shouldnt_look_at_welding_flashes/
|
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"text": [
"The real-life flashes are so bright (including ultraviolet radiation) that they can literally burn the retina (the nerves in your eye). \n\nRecordings of them are not capable of reproducing that brightness, so they're safe to watch.",
"They are bright enough to damage your eyes. Just like you shouldn't look at the sun.\n\nBut obviously, looking at a recording of it is fine, as it can't get brighter than full white of your screen. Which is nowhere close to as bright as seeing it in person.",
"It is because of the ultraviolet wavelength that is produced by the arc welding. That is why only the persons involved wear the shields with the polarized lens in the helmet. It is okay to look away at a wall 180° opposite from the arc welding and just see the light flashing on the wall. Looking at a recording of it won't do harm. The camera is looking at it. There are filters made for cameras to film that kind of work. \n",
"A recording will be limited in brightness by the total output of the screen that you're looking at, and that's limited to be a safe amount of light.\n\nThe welding arc itself is not limited like this, so it can be much brighter. Worse, it consists of a lot of ultraviolet radiation. I've experienced the dangers of this first hand—I needed to do a few inches of welding and din't cover my arms. The resulting UV burn was worse than any sunburn I've had. You do *not* want to expose your eyes to that level of radiation. ",
"A friend of mine got \"welder's burn\" in an unusual way (this was 10 years ago, facts may be skewed). He woke one morning and his eyes were crusty and were hurting. Eventually he figured out or remembered coming home the night before (probably buzzed) and checking on his chicken coup when lightning struck directly in front of him causing his eyes to get burned.",
"The light emitted by the arc of a welder is so bright it can burn your eyes and permanently damage them.\n\nLooking at a recording will be fine though - a tv set can only ever emit a certain level of brightness, so will be perfectly safe to look at - anything brighter than the limit of the tv will be darkened until it reaches that maximum point - generally very right compared to the rest of the picture on the scene so it looks correct, but not dangerous in any way.\nAt the same time, when recording very bright lights such as a welder, the sun or a laser, you can risk damaging the camera that is recording it, as some light sources will be strong enough to burn the sensor that records the image or damage the processing electronics that save the footage, so it is generally recommended not to focus on very bright light sources too much (though obviously most cameras are fine having the sun or a welder in the scene, as long as you are not zooming right in on them for long periods).",
"I have looked at welding flashes. beyond the obvious retinal damage that could occur (I haven't had that happen) there are the temporary spots of blindness that make it impossible to see what you are working on. Imagine that you have peripheral vision but you can't see anything directly in front of you. So there is an immediate practical reason for eye protection. ",
"Could you be in danger watching if you are at a long distance? Say 50+ yards",
"As someone who has had welders flash and been to the hospital about it, the closest approximate is a sunburn on your eyes. It's worse than using a knife and ramming your thumb down onto it and splitting the nail halfway. 48 hours of nonstop teary eyes, dirt/glass sensation, and eye goobers so thick you have to pry your eyes open. The antibiotics they give you are not clear drops, they are a paste that you have to put under your eyelid and move your eyes around to disperse. So now you can't see, you're in pain, and you feel like you have rocks in your eyes. So for the eli5 part, because it's a bad idea. Tvs is all good though.",
"They have auto darkening welding masks that are about the shade of sunglasses normally, and when they detect sufficient ammounts of light they darken to a shade that's safe. I've tried one of those masks against the sun, and it didn't work more than 50% of the time. That's how bright a welding arc can be"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
||
8zhtf5
|
if there was life on a planet the size of the sun, would those life forms be proportionally bigger than life on earth? how and why?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8zhtf5/eli5_if_there_was_life_on_a_planet_the_size_of/
|
{
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"A sun-sized planet would be immensely hot, and have an absolutely crushing force of gravity at the surface. If any life at all existed there I would expect it to be very small. Those aren't exactly good conditions for the evolution of complex lifeforms.",
"Nope. I think they would be way smaller, if they were to be made from same elements as we are. The reason is gravity. It’s safe to believe that this giant planet would have surface as we enter the planet rather than condensed gases. This surface would produce so much gravity that if a person of our height fell down simply by tripping over steps, it could break his head. That’s not what they want. So in a long process, people with smaller heights will take over.\nBut there is one problem. There is a mathematical limit for a size of star called Eddington luminosity. So there must be limit for planets as well because planets are way more dense than stars are. So there maybe a limit that won’t let a planet grow/built itself as big as sun.",
"I am not a cosmological or anything like that, but I'm going to guess that a planet the size of the sun would have *incredible* gravity (if a rocky planet that size could even exist , which I doubt). High gravity means denser tissue/ bodies and most likely smaller creatures.\n\nAgain, I don't think such a planet is actually possible."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
2alc4n
|
why i feel sick after eating 'rich', fatty or sickly sweet foods?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2alc4n/eli5_why_i_feel_sick_after_eating_rich_fatty_or/
|
{
"a_id": [
"ciwc41v",
"ciwe7f2"
],
"score": [
2,
7
],
"text": [
"If your diet is rather healthy eating food high in fat or sugar will make you feel ill since your body isn't used to it",
"Ultimately, any food you consumed is intended for use as fuel by your body. Fats are not easily converted into fuel and requires more energy to breakdown into readily available fuel(hence why we store it for later use). This process takes more of your \"total energy\" and makes you feel groggy, nauseous etc since the body is focusing energy to process it instead of normal function.\n\nAs for sugar, your body uses broken down sugars as direct fuel. An excess of this again causes your body to go into overload to either turn it into energy or store it as fat. These processes are taxing on the human body.\n\nOne thing to always keep in mind with diet is that our ancestors had to work very hard to fill their stomachs (most of them anyway). Through evolution the human body has gotten accustomed to eating smaller amounts. Today, food is readily available in mass excess and causes the body \"confusion\" when trying to process so much. Cupcakes, butter, oils, and other sugary fatty foods are troubling to digestion; whereas fruits, vegetables, and many meats are not as difficult for us to process.\n\nThe explanation could go on for days, but eating naturally occurring foods will substantially reduce the \"overwhelmed\" feeling your body has when eating rich foods.\n\nI'm on mobile and will clarify if I missed anything."
]
}
|
[] |
[] |
[
[],
[]
] |
||
15nflx
|
jewish beliefs.
|
I've never really been very knowledgeable on any religions. I've met this girl and her family who are jewish. It seems like a pretty strict regimen. I've been invited to synagogue a few times but have politely turned them down so far. I'd like to have a better understanding of the beliefs so I can have a proper conversation with them, but sway from asking them directly to avoid long winded explanations that would leave me more confused than before. Can you guys explain it like I'm five?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/15nflx/eli5_jewish_beliefs/
|
{
"a_id": [
"c7o12wq"
],
"score": [
4
],
"text": [
"Jews believe in God and the first five books of Moses. They don't believe that Jesus was the son of God or the Messiah. Jews are still waiting for their Messiah.\n\nThere are 613 commandments in the bible ranging from \"Remember the Sabbath day and keep it holy\" to \"don't mix two kinds of fabric together in your clothing\". Jewish life is defined by the observance of these commandments.\n\nDid you have more specific questions."
]
}
|
[] |
[] |
[
[]
] |
|
6ea5sp
|
what causes a daily rise and fall in ground water levels?
|
I recently built a monitor, using float switches and a raspberry pi, to monitor my house sump pit. I've gathered data over the past week and noticed a small daily (roughly) cycle in the amount of water entering my sump pit. I would like to know what causes the cycle. The sump pit is ~2m below grade. The weather has been consistent (sunny & dry) for the last week.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6ea5sp/eli5_what_causes_a_daily_rise_and_fall_in_ground/
|
{
"a_id": [
"di8udqo"
],
"score": [
2
],
"text": [
"Not a scientist. But I worked on rain garden and community education. I bet if your watershed is large enough it could be water accumulated from a storm days ago that has slowly made its way to you.\nWhat's the terrain like?"
]
}
|
[] |
[] |
[
[]
] |
|
38r6zj
|
Has time altered the way people report the holocaust?
|
Are history books reporting it any differently than newspapers did at the time?
In particular I saw a moderately upvoted post on reddit saying that all the gas in the camps was never used to kill people, just pests. It said that during the years we've romanticized the war so much that we're not studying facts anymore. Now, I know that the holocaust definitely happened and that's not up for debate in this sub (I read all the other holocaust threads in this sub). I just want to know if there's any evidence of "facts" about the war changing over time.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/38r6zj/has_time_altered_the_way_people_report_the/
|
{
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"text": [
"A relevant link. The Daily telegraph reported on extermination camps in 1942. It cites the original article as well as its reception, which was very low and didn't gain much traction.\n\n_URL_0_\n\nedit: Generally, in the West today, we very much focus on the Holocaust as athe central crime of the war. But during the war, also due to not knowing enough about it, it was a bythought rather. This changed when the Concentration camps and extermination camps were liberated and the Allies saw the crimes first hand.",
"Your actual question \"Has time altered the way people report the holocaust?\" is quite interesting and someone may come along to answer it. I just want to note that this:\n\n > all the gas in the camps was never used to kill people, just pests. It said that during the years we've romanticized the war so much that we're not studying facts anymore.\n\nis standard denialist nonsense. The only reason that person is saying \"we're not studying the facts\" is because they don't like the outcome of the studies. There's no underlying change in reporting that that person is relying on. Perhaps they're getting a warped view because of selection bias and/or confirmation bias (i.e. being \"in a bubble\" on the internet). The video linked in the comment you refer to is from the \"Holocaust Hoax Museum\", which supports the idea that the author is getting their information from denialist sources. It's easy to get stuck in a self-reinforcing bubble of sources on the internet and then think \"the research has changed\"."
]
}
|
[] |
[] |
[
[
"http://www.theguardian.com/media/greenslade/2015/jan/27/daily-telegraphs-holocaust-article-in-1942-that-went-unheralded"
],
[]
] |
|
2jc0s2
|
why does the military use the word "click" when referring to distance? how far is it, and where did it come from?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2jc0s2/eli5_why_does_the_military_use_the_word_click/
|
{
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"text": [
"Also, they spell it Klick (just using K for kilometer)",
"Saying klick in the radio walky-talky thingy is simpler then saying kilometer. Also it can't be confused with other words easyly. ",
"It is short hand for Kilometer. It is used by the military as well as long haul truckers and a few other professions. ",
"Phonetically we use the word Kilo for the letter K. We use the word Klick to identify the metric unit kilometer. \n\nIt's actual origins are unknown, but it's generally believed to be somewhere around the 60s~.\n\n_URL_0_\n\n"
]
}
|
[] |
[] |
[
[],
[],
[],
[
"http://usmilitary.about.com/od/theorderlyroom/f/faqklickdef.htm"
]
] |
||
dl5jpy
|
why is the paint i put on the thing i'm painting still wet, but the paint i got on my shirt already dry?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/dl5jpy/eli5_why_is_the_paint_i_put_on_the_thing_im/
|
{
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2
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"text": [
"More paint dries slower. I would assume there isn't as much paint on your shirt. Not only this, but Your shirt is probably moving around a lot, which exposes it to fresh air and acts like blowing on paint to dry it.",
"Your shirt is made of fabric, which absorbs moisture pretty well - better than your average wall or whatever. So when the paint hits your shirt, your shirt fairly quickly absorbs the liquid content, which is small enough that it's almost unnoticeable. The pigments and solids of the paint stay on the outside of the fabric, feeling dry much more quickly than if you were painting on a hard surface.",
"The biggest thing with a process like drying is the amount of surface area exposed compared to the total volume of paint. When you were painting the thing, only the side of the paint facing the air was drying. When it was on your shirt, both sides of the paint were drying, and the shirt also \"wicked\" out the paint blob to a bigger diameter, increasing the Surface Area to volume ratio more.",
"Because paint is evil. For example, if you were to spill a can of paint, it will automatically dry extremely quickly to ensure that you can’t clean it up properly. However, if you were to paint a wall in the exact same paint, it will take hours to dry so that you definitely will tarnish your hard work and get paint on you, potentially even tracking it round your house."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
26bvt1
|
- how to play blackjack?
|
Going to the Casino for the first time tonight, and I want to play Blackjack! But I don't want to show that I don't know what I am doing.
Edit* Thanks everyone for the great explanations on how to play Blackjack! Very helpful, I hope I make some money tonight
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/26bvt1/eli5_how_to_play_blackjack/
|
{
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"text": [
"Practice this line before you go\n\n_URL_0_",
"Anything 10 or higher in the deck = 10\n\nAces can be either 11 or 1\n\nAny other cards are face value (what you see is what you get)\n\nIf you get A + (facecard) you have \"black jack\" and automatically win unless the house has the same - and that's a push so you either put all that jackpot into the next hand or you get your money back depending on the casino. \n\nyou will be dealt two cards up front. One face up and one face down. You need to leave the face up one face up, but your goal is to get to the number \"21\" without going over. \n\nYou can \"stay\" at your number (your cards added together) but if the dealer has a higher number you lose\n\nYou can \"hit\" which means to take another card. Whatever this card is will automatically add to your total. If you had 3 of hearts and 6 of diamonds you have 9. Since the largest card is A with 11, you should hit because you *cannot* go over 21. Let's say you get a 7. You now have 16. You can continuously \"hit\" until you bust, but each \"hit\" card is placed face up, so you only have the one card that was given to you face down as a secret.\n\nMost people tell you to \"hit\" on 16 and \"stay\" on 17. Ultimately it's your choice. ",
"The dealer usually will tell you what you should do for good tips, and they are not there to take your money. thats what the casino is there for. Being new is no big deal, beginners luck and you can learn alot by asking the table what you should do. What the dealer tells you (playing by the rules) is a 47% chance of you winning which means the casino eventually wins.\n\nBe careful of just jumping into a table, you could ruin someones streak of luck by messing up the order of cards that come out. Ask whoever is playing if you can join.\n\nThe only other advice is I dont hit on 15 because I always bust. counting cards doesnt work if they have a continous card shuffle going on and 6 decks is a lot to count :)\n",
"Basic game structure:\nYou will be dealt 2 cards face up. All face cards have a value of 10 and all other cards have the value of the number on the card. You want to get close to a total of 21 without going over, or \"busting\". Aces can be either 1 or 11. If you want another card, you say \"hit\" or tap the table next to your cards. If you don't want another card, you say \"stay\" or wave your hand over the cards.\n\nThe dealer gets 2 cards. One face up and one face down. If the dealers cards add up to 16 or less. They have to ask for another card until they have at least 17.\n\nTo win. You have to score better than the dealer. This could be as simple as not busting when the dealer busts.\n\nStrategy tips:\nAlways assume that the dealer has a face card hidden, since there are more face cards than any other cards. So if the dealer has a 6 showing you will assume their score is 16. Which means that they will have to take another card and will likely bust. In this scenario you should play safe and only hit if you have less than a 12.\n\nIf the dealer has a face card showing, you should assume their score is 20 and take more risks. If you have a score of fifteen, you should hit because you will probably lose anyway so it doesn't matter if you bust.\n\nAces:\nIf you have an ace and your score is less than 17, you should hit. Since the ace can also be a 1. You are in no danger of busting and face no risk by hitting.\n\nSplitting:\nIf you have two of the same card, you are allowed to match your bet to split them into two hands. You want to do this when the dealer has a high risk of busting, or if you have two aces. Two eights are often split as well.\n\nDoubling down:\nWhen your turn first starts you can double down. You double your initial bet, and get one additional card and then your turn is over. You do not get to hit anymore.\n\nAsking the dealer:\nThe dealers are experts on the statistically best way to play blackjack. Also the dealers want you to win. When people win, the dealer gets more tips and doesn't get insulted by sore losers. If at any point you aren't sure what you should do, just ask, \"what does the book say here?\" The book refers to the book on blackjack strategy. Follow the advise they give you.\n\nInsurance:\nIf the dealer shows an ace you will be offered the chance to buy insurance. This means you can pay money, and if the dealer has blackjack (a face card and an ace) you won't lose your initial bet. Don't buy insurance, it isn't worth it.\n\nCasino etiquette:\nLook for a table with an empty seat. Sit down and get your money ready. When the hand is over give the dealer your money and they will give you chips. When leaving the table, ask to \"color up\" and the dealer will exchange your chips for larger value chips so you can go cash out or go to another table\n\nIf you have any questions let me know and I'll be glad to answer them",
"Seriously though, here's a simple explanation:\n\nThe game is played \"against\" the dealer. You are not playing against other players. The goal of the game is to get as close to 21 points as possible without going over. If you have more points than the dealer without going over 21, then you win exactly as much money as you bet. If you have fewer points than the dealer OR if you go over 21 (which is called \"busting\"), you lose your bet. If you have the same number as the dealer it's a tie (also called a \"push\") and you don't win or lose anything.\n\nCards 2-10 are worth their corresponding number of points regardless of suit. 2 = 2 points, 9 = 9 points. Jacks, Queens and Kings are worth 10 points, and the Ace is worth either 11 points or 1 point - your choice. So a 9 and and ace can either total 10 or 20. \n\n\n1. Everyone places their bets on the table \n2. The dealer will deal two cards to every player, face up. To himself he will deal one card face down and the other card face up. \n3. Each player will then take their turn, starting with the first person to the dealer's left (I think). You only get one turn per round. You can either say \"hit\", which will give you another card, or \"stand\", which means you're staying where you're at and it's the next player's turn. \n4. After everybody has taken their turn, the dealer will reveal the face down card. The dealer will now \"play\" the game according to pre-set rules. Typically the rules are: the dealer must continue to \"hit\" until reaching 17 or higher, at which point he must \"stand\". If the dealer busts, everybody who didn't already bust wins. \n\nSPECIAL RULE - BLACKJACK\nAny card worth 10 points, when paired with a Jack gives you \"Blackjack\". If you have Blackjack, you automatically win (1.5x your bet) UNLESS the dealer ALSO has Blackjack, in which case nothing happens.\n\nIf, after all the cards are dealt, the dealer's card that is showing is an Ace, you will have the option to buy \"insurance\". You can \"buy\" up to half the amount that you have already bet. If, for example, you bet $10, you can buy anywhere from $1 to $5 of insurance. Once everyone has either bought or declined insurance, the dealer will secretly check to see if he has blackjack. If he does, everyone loses their initial bet (unless they also have Blackjack of course), and those with insurance will \"win\" whatever amount they decided to buy ($2 - $10 in this case). \n\n\nIf you are still confused, just watch a couple hands and it will start making sense. Also, be polite with the dealer, and they should be polite with you if you do anything that isn't allowed (ie: trying to grab your chips off the table after cards have been dealt). \n\nIf you want to practice playing beforehand, go here: _URL_0_\n\nHave fun!\n",
"Oh, one more thing. You're welcome to say \"hit\" or \"stand\" or \"stay\" or whatever but most people just use hand signals. Tapping the table twice means hit. Gently waving your hand as if to say \"stop\" means stand.",
"Besides all the rules of the game that people are posting, there are several little table do's and don'ts. I went with a friend who had never played at a casino before. I taught him all the game rules, but forgot to tell him about all the little casino things that he didn't know but were second nature to me. \n\nLike, don't touch the cards, ever. Unless it's one of the few casinos that still deal hands face down and you pick them up to look at them. But a vast majority now play your hand face up and the dealer does everything. Indicate hit by tapping the table, indicate stand by waving your hand. \n\nStack your bet in one pile, If your bet is more than one denomination of chips, put the higher denomination on the bottom. \n\nNever touch your wagered chips once a hand is being dealt or played. The exception is if you get a blackjack. Once the dealer pays you, you can take your winnings, make you next bet, whatever.\n\nTo double down, simply place an equal amount of chips next to your original bet. \n\nTo split, place an equal bet next to your bet, but a slight distance apart, and indicate a split by making a '2' pointing gesture with two fingers."
]
}
|
[] |
[] |
[
[
"http://youtu.be/mKl11EzMTAE?t=31s"
],
[],
[],
[],
[
"http://wizardofodds.com/play/blackjack/"
],
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|
37hk65
|
if you only had one gallon of gas left in your car, what would be the best way to get the furthest distance?
|
Say you are on the highway and notice you have only one gallon left in your tank and you don't know where the nearest station is. Assuming that time is not an issue and there are no other cars on the road and the road is perfectly flat, how could you get the most distance from that one gallon of gas? Would it be best to coast for a while, then accelerate back up to speed before coasting again and repeating, or would the extra energy of accelerating cancel out the benefit of coasting? Would just maintaining a constant speed be best? Or is there another method that would be better?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/37hk65/eli5_if_you_only_had_one_gallon_of_gas_left_in/
|
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"Accelerating requires a lot of energy, the best way is to maintain speed. Use cruise control if you can. Also, higher speeds create more friction, so keeping your speed on the lower side would help, too. I think for most cars, maximum fuel economy is around 55MPH.",
"Your car will have an optimal speed for traveling the greatest distance per unit of gas, you would do your best to maintain as close to that speed as possible until you were out of gas.\n\nThe manufactures know this speed, through internal testing and math, but its pretty irrelevant to a consumer so there is no need to tell you it. It's likely between 40-60mph, again depending on the car and circumstances\n\nEdit: One cool thing to add on. Planes actually *know* the speed they need to do this type of activity, its a core part of flying (there are a few different ones with planes since you are dealing with more dimensions) and its used pretty regularly in flight planning.",
"Well, first priorities would be to reduce unnecessary engine loads and increase effeciency: switch off A/C, close windows & sunroof, find the optimal speed (engine revs & vehicle speed) and coast when possible. Do not coast all the way to 0 and back up but balance it to maintain the velocity in the optimum range. Also, hope that your tire pressures are good... :) ",
"turn the engine off and push! it'll take forever but you'll get there and still have a gallon of gas!",
"There are a whole range of techniques specifically toward driving for optimal fuel economy, it's a practice called Hypermiling. Look it up.\n\nOne of the most effective of the techniques is the \"pulse and glide\" method, which takes practice. The idea is counter intuitive - speed up when going down hill to build sufficient energy to coast up the next hill. It's fuel economically cheaper to accelerate when you're using gravity to assist. There was a recent fuel efficient car race, the kind of college graduate challenges where they build cars that get 3k mpg, and they mostly use this method.\n\nThe point is to read up on hypermiling.\n\nIn the longer term, you can build/install a couple circuits that indicate whether your car fuel management computer is in open loop or closed loop. When in closed loop, your computer is running in one of it's most fuel efficient modes for that given speed. If in open loop, it's using a fuel/air ratio table and is basically just dumping fuel into the engine, which often happens when under load or accelerating. Such devices are available with a bit of googling, and they're there to teach you how to drive.",
"Air up your tires if possible. Hypermilers get into serious overinflation but you can get a significant improvement (and sharper cornering at the expense of some ride comfort) by inflating to the max pressure listed on the tire sidewall (usually 44 PSI) rather than the car manufacturer's recommendation (usually in the low 30s, and set with a smooth ride on the test drive in mind).\n\nAssuming a modern EFI car, DON'T coast, or at least don't coast in neutral - if you leave it in gear (highest possible if manual, D if automatic) and take your foot off the gas while going downhill, the computer will sense this, open all the valves at the same time and stop the fuel supply. Basically the engine converts to an air pump driven by the wheels. It's called deceleration fuel cut off.",
"The majority of fuel consumption at highway speeds is the result of wind resistance. \n\nYour best strategy would be to get behind a semi truck trailer as close as you can, SAFELY, and draft off of them. They typically cruise at or near most vehicles' optimal speeds (55-65mph), and by riding in their wind draft (which you can see benefits as far back as 100 feet according to Mythbusters!) you will save quite a bit, up to 3-4 mpg in my informal testing. ",
"The optimal speed for the highest gas mileage is about 40-50 mph. Stay at this speed, keep your windows up and AC off. Then avoid hitting your brakes for anything. Stay looking ahead and if you see something you will need to stop for coast up to it. Tap your brakes a little bit early if you think you will still need to use them after coasting.",
"I think if the whole goal was to maximize the distance from that one gallon, ignoring the time it takes, the best method would be this.\n\n1. Open Door\n2. Get out of car.\n3. Close the Door.\n4. Walk to Rear of Car\n5. Push the bitch, and be glad you bought that smart car. \n\nNo hills and a perfectly flat road means that you can get a fair amount of speed without much issue. ",
"How I did this in real life: \n\n* overinflate your tires\n* accelerate as rapidly/smoothly as possible\n* turn off all accessories (cut off the AC belt if possible), \n* close all windows, \n* drive at your car's optimal speed (btw 60-70 mph) insuring you're in the car's highest (overdrive) gear.\n* take the foot off accelerator when possible (coasting), or use cruise control.\n\nI actually had a real-life emergency about 15 ago when I was driving a 1980 Cadillac Eldorado from Las Vegas to Los Angeles and only had about 1 gallon of gas. I know it was a gallon because i'd already run out and gassed up with 1 gallon at the Arco near the entrance to LV Avenue. My GF had money, but she was already waiting for me at the border, so in order to insure I could make it, I did all the above things. Luckily, I learned that all large cars lose TONS of fuel on acceleration, so I got on the freeway with the smoothest/fastest acceleration i could get and then closed the windows, turned off the AC and coasted around 60 mph till we got to the Primm resort gas station... we made it barely on fumes, all 40 miles in a car that normally only gets 16 mpg."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
|
4jtdrn
|
what happens in our brains when we realize we've driven miles/minutes and don't even remember consciously driving them?
|
Side note- doesn't this happen in dreams? You go places and can't remember how you got there...is there a relation?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4jtdrn/eli5_what_happens_in_our_brains_when_we_realize/
|
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"text": [
"This happens when your subconscious mind starts handling processes that you normally control consciously. Normally, you're paying attention to the road and staying alert. When you're an experienced driver, you can pass the task of staying between the lines to your subconscious, and stop being alert for hazards. Because you're performing subconsciously, your mind doesn't bother to record these times to memory, so you won't remember more than a hazy idea of driving those minutes/miles. When something snaps you out of the subconscious routine, you realize you haven't been alert for hazards, which is a decidedly unsettling feeling.",
"It's actually a relatively well known and documented phenomenon called Highway Hypnosis. \n_URL_0_",
"When you have the same stimulus for a prolonged period of time, your brain stops focusing on it, and instead chooses to focus on different, more important matters and let your subconsciousness take over. \n\nThis is the same as eye floaters. If you ever look at a bright light and see little blurry dots/lines in your vision, those are usually due to coagulation of the jelly-like liquid inside your eyeball. They are always there and are always visible, but your brain filters it out because you can do little about it and it isn't a good investment to recognise them. \n\nIn the same way, driving along a road for hours leads to the same stimulus being applied over and over, so your brain chooses not to focus on it. It's only when something changes that you actually realise it",
"I recently read [this article that explains](_URL_0_) part of what happens when your subconscious brain takes over and also explains how something like forgetting your child inside the car happens. Apparently your basal ganglia is to blame."
]
}
|
[] |
[] |
[
[],
[
"https://en.wikipedia.org/wiki/Highway_hypnosis"
],
[],
[
"http://www.parents.com/baby/safety/car/danger-of-hot-car-for-children/"
]
] |
|
bfec9a
|
why do/how can "zero/low calorie sweeteners" have sugar, specifically dextrose, in them, if they are supposed to be sugar substitutes?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bfec9a/eli5_why_dohow_can_zerolow_calorie_sweeteners/
|
{
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"text": [
"Most say no or low sugar because they generalize glucose as sugar and other forms not. Also glucose is harder to metabolize than say sucrose, dextrose, fructose, lactose etc. So technically they aren't wrong but also not right. No sugar substitutes tend to use saccharin instead of a \"-ose\"",
"Most low calorie sweeteners work by being sweeter than regular sugar. Aspartame (which is actually a protein and not a sugar) is the same 4 calories per gram as regular table sugar. The difference between aspartame and sugar is that aspartame is about 400 times sweeter than sugar. This means that you can make something equally as sweet, but use 1/400th as much sweetener. So if a regular can of soda has 100 calories, making the same soda with aspartame instead of sugar will give you 0.25 calories.",
"According to my research, dextrose IS glucose.\n\nTo be more specific, dextrose refers to the the right hand isomer of glucose.\n\nIt is also known as dextrose, because it is dextrorotatory (meaning that as an optical isomer is rotates plane polarized light to the right and also an origin for the D designation. [[Source]](_URL_0_)\n\nDextrose is the most common isomer as it is the only naturally occurring of the two.\n\nAs for your original question. Are you able to give some specific examples and I'll see what info I can find for you."
]
}
|
[] |
[] |
[
[],
[],
[
"https://chem.libretexts.org/Bookshelves/Biological_Chemistry/Supplemental_Modules_(Biological_Chemistry\\)/Carbohydrates/Monosaccharides/Glucose_(Dextrose\\)"
]
] |
||
yrlfp
|
how wells work, and why well water is safe to drink
|
So can you just sink a well pretty much anywhere and have a good chance of finding water? And why don't wells usually need purification?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/yrlfp/eli5_how_wells_work_and_why_well_water_is_safe_to/
|
{
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"c5y7xu3"
],
"score": [
10
],
"text": [
"In a lot of places, the soil is saturated with water up to a certain level (elevation). If you dig a hole through this layer, that water will drain into the hole (the well) in a way that looks something like this: _URL_0_\n\nYou can't just sink a hole anywhere. It depends on the depth to the water level (water table) in a particular area, which depends on a lot of factors, including geology, climate, and rainfall in the area. In some places, there's water only a few feet under the surface. In other places, you can dig hundreds of feet and find no moisture. Other places used to be like the first case but are now like the last case due to excessive pumping.\n\nGroundwater is often safe to drink with minimal or no treatment because the soil itself acts as a water filter, and there may not be any infectious contaminants in the area around the groundwater. But groundwater is by no means always safe -- a few areas around the world have severe natural arsenic contamination in their groundwater, leading to a lot of problems.\n\n(I'm a civil engineer.)"
]
}
|
[] |
[] |
[
[
"http://groundwater.oregonstate.edu/groundwater/images/depressionb.gif"
]
] |
|
2glmrk
|
how a company like netflix works?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2glmrk/eli5_how_a_company_like_netflix_works/
|
{
"a_id": [
"ckk9m6b"
],
"score": [
7
],
"text": [
"They purchase DVDs to rent out by mail, and license shows and movies to stream out.\n\nSubscribers pay a monthly fee for streaming and maybe DVD rental. Netflix uses this money to pay for the license fees for the streaming, and to purchase new DVDs."
]
}
|
[] |
[] |
[
[]
] |
||
1jnvk1
|
how does pantone influence fashion and design? what gives them the authority to choose the color palette for the season?
|
I know that Pantone isn't primarily a fashion company, so why do they put out the [Color Report](_URL_0_)? And is this report a *reflection* of the colors for upcoming seasons or a *suggestion* that sways the designers and market? And why is a printing company talking about fashion anyway?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1jnvk1/eli5_how_does_pantone_influence_fashion_and/
|
{
"a_id": [
"cbgj0uj"
],
"score": [
2
],
"text": [
"They don't choose the colors fashion designers will pick, but they do provide a consistent point of reference on a given color. Instead of \"light blue\" I can tell you I want Blue #123 and it will be exactly what I wanted. Certain colors trend more popular for given seasons, they can compile those as a sort of guide accordingly so folks are referring to the same tones. "
]
}
|
[] |
[
"http://www.pantone.com/pages/fcr.aspx?pg=21057&ca=4"
] |
[
[]
] |
|
egqq06
|
How does the brain isolate a sound and focus on just a specific sound?
|
When you hear a music, ambient sounds, people talk or anything with sound. You can just focus on 1 sound and isolate all other like when hearing a music or musical instruments you can focus on the violin sound or the trombone or the flutes or maybe hear only a certain frequency or a specific person talking. How does the brain know what to isolate and focus on, And how does it do it?
Edit: Thank you all so much for your comments and answers, I really appreciate them. This question has been bugging me for a few weeks and I couldn't really find an answer on Google since Google just gave me how do you sound proof a room or isolate a frequency with speakers. It wasn't really reliable so I decided to ask real people what they thought. Again I thank you for your time and consideration to answering this question and i hope some of you out here on Reddit who might have had a similar thought about it now finally have an answer. Thank you all.
|
askscience
|
https://www.reddit.com/r/askscience/comments/egqq06/how_does_the_brain_isolate_a_sound_and_focus_on/
|
{
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"fc9q429",
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"text": [
"If I remember correctly from my psychology course, one model (the attenuation model by Anne Treisman) proposes that there is a mechanism in our brain that adjusts the \"strength\" of stimuli, or sound signals if you will, to our conscious awareness. This mechanism is both automatic and manual, meaning that stimuli that our brains deem irrelevant, or less important, are lowered and vice versa. If we focus our attention to one particular stimulus, a specific instrument in a song for example, this mechanism then strengthens that signal to our conscious awareness. I'll post a link below. It's really quite interesting.\n\nOne can think of it as if there was a mental mixer in our brains. You know, like the ones you may have seen in music studios with a bunch of tracks and volume adjusters on them?\n\n[The Attenuation Model by Anne Treisman](_URL_0_)",
"This is a central question in a lot of areas of hearing research, especially related to how we can comprehend speech in noisy environments (see the [Cocktail party effect](_URL_2_) for some background). At a basic level, this problem involves a couple steps. \n\nFirst is the task of separating the mixture of sounds that our ear processes at the cochlea into auditory objects - think different voices, instruments in music, or similar. This involves (partially overlapping) processes called auditory streaming, source segregation, and scene analysis, terms which will get you a lot of relevant results if you search them. Essentially, hearing at the earliest stages involves a natural process decomposing sounds into frequency components (e.g., high pitch and low pitch sounds, albeit with much greater precision than that) akin to a [Fourier decomposition](_URL_0_) of the sounds arriving at your ears. From there, there are brain regions involved in reversing this process to infer the sources of different sounds, so that you can identify things like who, what, and where sounds are. This process is highly complex and only partially understood, but relies on many cues, including onset/offset times of sounds, frequency information, listener expecatations and the prior likelihood of a sound occuring, and others. [Shinn-Cunningham (2019 < - pdf)](_URL_1_) and [Middlebrooks and Simon (2017 < - paywalled)](_URL_3_) have nice overviews with some more detail.\n\nJust as you mentioned, once we've isolated objects, next comes the process of picking one out to focus on, a process typically referred to as selective attention. This is a process much better understood in visual perception than auditory perception. It may seem fairly simple how, once the objects in the environment have been separated, we can pick one to focus on. However, in the brain this is a complicated process and involves coordinating, for example, the need to focus on things that are relevant to your current goals (like listening to your friend in a restaurant) and monitoring for other important sounds (you don't want attention to your friend to prevent you hearing someone should 'Fire' or the restaurant calling out the number for your order). \\[As an interesting aside, one finding in this field is that it's difficult if not impossible to focus on two objects at once -- multitasking doesn't really occur when listening to sounds -- and if you think you can do it, you're probably just switching attention back and forth rapidly, which tends to impair your performance at both tasks\\]. Searching auditory attention or auditory selective attention will give you a lot of resources on this topic, and the the Shinn-Cunningham article I cited earlier goes into some detail as well.\n\nTL;DR: the auditory system is adept at separating a mixture of sounds into its component objects by relying on many cues like onset/offset times and many others, and after doing this uses attention to focus on a single object at a time to suit your needs.\n\nThis is the tip of the iceberg on this topic and didn't want to go to deep here, but I'm happy to answer more questions if people have them!"
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Attenuation_theory"
],
[
"https://en.wikipedia.org/wiki/Fourier_analysis",
"https://www.cmu.edu/dietrich/psychology/shinn/publications/pdfs/2019/2019cogneuro_shinn.pdf",
"https://en.wikipedia.org/wiki/Cocktail_party_effect",
"https://link.springer.com/chapter/10.1007/978-3-319-51662-2_1"
]
] |
|
av7up3
|
German Army in the 1920s - Training of the Officer Cadre
|
Greetings all.
Recently I was at a conference and someone mentionned briefly at a glance that Germany in the 1920s was heavily restricted in terms of military personnel as we know. But the goal of the head of the army (?) was to give more adequate and higher level training to have people be able to do function 2-3 higher than theirs, in order to have a force capable of increasing rapidly without loosing competence in the higher ranks/functions.
Is this accurate ? If this is so, what was the actual training strategy/plan/program that Germany used for it ? Who was the man in charge, where did his thinking come from and how did he do ? Did it worked ?
Thank you
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/av7up3/german_army_in_the_1920s_training_of_the_officer/
|
{
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"text": [
"In July 1919 a certain Hans von Seeckt, already having been Chief of Staff for the Ottoman army in 1918, became the last Chief of Staff for the German Imperial army. After the general staff became illegal according to the terms of the Treaty of Versailles, October 1. 1919, von Seeckt was the first to become chief of the so-called 'Truppenamt' (\\~'Bureau of the Forces'), an institution that de facto was a more or less secret continuation of the general staff. (The allies had suspicions but couldn't prove anything)\n\nIt's not 100% clear, if it was his very own idea, but the rule, that every member of the new army had to be trained for assignments **at least 1** rank above their actual rank was introduced when von Seeckt was in charge of the formation of the Reichswehr.\n\nThe ultimate goal was for him and other officers like e.g. (to be 'Reichswehrminister', \\~ ministers of defence) Groener and von Schleicher a strong german army able to reestablish Germany as a military power and if possible revenge for the defeat in WW1. Effectively the whole Reichswehr consisted of people devoted to this goal. It was the military who decided who entered the Reichswehr after all.\n\n1920-1926 von Seeckt was 'Chef der Heeresleitung' (\\~ 'Chief of Army Command'), de facto chief in command of the German army. It was during this time, that cooperations with the Soviet Union in the development and testing of tactics and army branches that had been forbidden by the Treaty of Versailles, such as tanks, air force and chemical warfare, were kicked off. \n\nAlso, in 1923, in the light of the french and belgian invasion of the Ruhr Area and the impotence of the Reichswehr to do anything about it, von Seeckt gave order to develop an actual road map for a capable german army. This road map, officially called 'Übersicht der Gesamtstärken und -Ausrüstung der Kommandobehörden und Truppeneinheiten des Feldheeres' (\\~ 'Outline of total strenght and equipment of command departments and combat units of the field army'), unofficially better known as 'Der Große Plan' ('The Grand Plan'), was developed by a secret group of majors and captains and presented in 1925. \n\nAlready in November 1924 an organization ('Wehrwirtschaftsorganisation', \\~ 'defense economy organisation') was established within the Truppenamt to prepare the mobilization of the german economy for a rearmament and establish ties to german industrialists.\n\nThe plan aimed for 102 divisions with about 3 million soldiers and 252 generals, exactly the numbers the Wehrmacht had September 1. 1939.\n\nVon Seeckt had to resign in 1926 on political grounds.\n\n1930-1933 he was elected member of the Reichstag with the national liberal DVP. \n\n1933-1935, already ill, he was military advisor for Chiang Kai-shek, helped to save german-chinese relations, reformed the chinese army and developed the strategy that ultimately forced the chinese communists onto their 'Long March'.\n\nHans von Seeckt died from a heart condition in 1936.\n\nFor further reading:\n\nCorum, James S. *The Roots of Blitzkrieg. Hans von Seeckt and German Military Reform.*"
]
}
|
[] |
[] |
[
[]
] |
|
99y81c
|
What was the curriculum like in segregated public schools? Was there any freedom to deviate from white schools to have a more accurate or nuanced view of US history or civil rights?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/99y81c/what_was_the_curriculum_like_in_segregated_public/
|
{
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"text": [
"This is a great question! The answer, like so many things in American education is basically: it depends. First, a some quick background about your question.\n\nDuring the colonial era, an educated man was one with a classical education. This meant, generally speaking, an intimate familiarity with Greek and/or Latin, some mathematics, and some Sciences. Colleges had different expectations around which Greek and/or Latin texts were the \"right\" ones but basically America's white boys studied the words of long dead white men, talked to other white boys and men about those dead white men, occasionally taught them to their daughters. The concept of studying history as a part of formal education didn't become the norm until the end of the 1800's. (More about that in a previous [question](_URL_0_)) To be sure, students would learn of history through their studies but they didn't typically study history as we think of it today. This notion of book-smartness as defined by a familiarity with the classics (AKA knowledge gained by studying dead white men) has endured for generations.\n\nIt's also necessary to establish the complex system that went into determining which bodies went to what school. The nature of segregation was defined by local laws and customs and there was a wide range of segregation and integration situations. Quakers across New England opened schools for free Black children or escaped enslaved children and adults and would typically send their children to the same school. Meanwhile, New York City and Boston had schools for Black children that were often located on the edge of the city, in buildings that weren't well-maintained. Parents often had to walk their children past better resourced schools and leave their child in a poorly heated building. (Black parents with means and resources could arrange for a private tutor for their child or pool their resources to host a tutor in one of their homes where they would study - you guessed it - the classics.) Up until the early-1900's, Indigenous or Native children would be forcibly taken from their families or sent to institutions to be schooled in \"American\" ways. Even white communities had different schooling options based on religious traditions or the child's parents social class.\n\nSo, now we get to the heart of what actually happened inside segregated schools. At one end of the continuum were schools like M Street (now Dunbar) High School in Washington, D.C. Anna Julia Cooper was the principal in the 1890's and helped establish the culture and curriculum. Cooper had a classics education (often showing up for classes at Oberlin that women weren't allowed to register for and simply taking a seat) and believed that in order to successful, her students needed a similar education. According to her writing, she saw a classics education as serving two goals: first, it provided her students (known as \"scholars\") with a quality education which would enable them to be problem-solvers, advocates, and teachers themselves and it would give them the knowledge necessary to move among the educated white population. \n\nAt Dunbar, the all Black student body studied Latin, Greek, logic, multiple branches of mathematics and sciences, and history. Given how difficult it was for Black and African Americans to get jobs in their chosen field, a large percentage of the teaching faculty had their PhDs, were published authors, scientists, or mathematicians. Remarkably, the man seen as the father of Black history, Carter G. Woodson, was a teacher at the school. Given he was working on his PhD and getting ready to begin publishing *The Journal of Negro History*, it's very likely his curriculum included a more nuanced view of American history than could be found at a nearby white high school. The exact nature of what children did in his class is unknown to us but multiple graduates, including Nannie Helen Burroughs and Charles R. Drew, wrote about the \"Dunbar difference\" and how their experiences shaped their Black and their American identity. The school's budget vacillated but generally speaking, it was a well-resourced, well-supported, segregated school. \n\n > Freedmen's Bureau question: What books do you use?\n\n > A teacher from Georgia replied: Any I can get. \n\nAt the other end of the continuum are the segregate schools of the South. The Reconstruction period is rich with narratives of freedpeople getting an education, building schools, and becoming teachers. In one community, 300 children and adults at a time crammed into a hastily built assembly hall for lessons in basic literacy. It still served as a school a generation later. In many cases, classes were held in churches and some offered classes 24 hours a day. Teachers would rotate sleeping and instruction just to keep up with the demand. Some communities raised funds and built schools for their children, paying tuition to a teacher from the North. One such teacher, Simon Beard was a minister who used a number of textbooks, including [Elementary History of the United States](_URL_1_) by George Payn Quackenbos which was distinctly Euro-centric. Black communities did whatever they could to educate their children. \n\nThat background is key to understanding the conditions throughout the 19th and 20th century in segregated Black schools in the South. Without a steady source of income from outside the community, it was incredibly difficult for teachers to provide a full, rich educational experience much less a nuanced, text-based understanding of American history. Some states went as so far as to close entire school districts to avoid integration and resource sharing while Mississippi rescinded compulsory education laws so districts could legally turn away Black children or towns could legally refuse to use taxes to support Black schools. \n\nTo the question of the freedom to deviate, it's not an exaggeration to say white school leaders did not care what happened in Black schools in any real sense of the word. If there was a Black teacher a group of white men wanted to harass, they might bring up the content of the curriculum, but it was an excuse. There were a few instances of schoolmen (the moniker for the mostly white men who ran schools and districts during the rise of the common school) inspecting poorly funded, poorly resourced Black schools and calling them \"sufficient.\"\n\nWhile some Black teachers had the opportunity through their church or social networks hear academics like W. E. B. Du Bois and Mary McLeod Bethune talk about the past and the future, in most cases, they barely had enough to ensure basic literacy for every child.\n\n-------\nResources:\n\nFairclough, Adam (2007) *A Class of Their Own: Black Teachers in the Segregated South*\n\nStewart, Alison (2013) *First Class: The Legacy of Dunbar, America's First Black Public High School*\n\nWalker, Vanessa Siddle (2018) *The Lost Education of Horace Tate*\n\nWilliams, Heather Andrea (2005) *Self-Taught: African American Education in Slavery and Freedom*\n\n\n"
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/7hhlvv/when_exactly_were_us_students_first_introduced_to/dqt1t36/",
"https://books.google.com/books?id=Fm8uAAAAYAAJ&dq=Quackenbo's%20United%20States%20History&pg=PP3#v=onepage&q&f=false"
]
] |
||
g6ovm
|
Is there a standard way to represent DNA in a computer (e.g. 1 codon per byte)?
|
If you need 6 bits per codon, are the other 2 bits in a byte used for anything? Or would you use 3 bytes for 4 codons? Just wondering if there's a standard.
|
askscience
|
http://www.reddit.com/r/askscience/comments/g6ovm/is_there_a_standard_way_to_represent_dna_in_a/
|
{
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"text": [
"Strings. (No, they're not memory-efficient, but you don't have to write custom functions for reading/writing to them.)",
"I've represented dna in bits before.\n\n0 for the major allele and 1 for the minor allele in a population. I kept a separate mapping of which allele was major and which allele was minor at any given position. It's the most efficient method. I needed a ton of stuff to fit in memory.",
"Well if you just generated a genome of yourself and want to send it with your resume in the most standard way possible today, well then you just take the FASTA format (just a plain ASCII textfile) of the genome (descriptions given elsewhere in the thread) and gzip its tarball (or just gzip the ASCII file itself). Most big chunks of DNA data you will find on repositories will probably be in this format today.\n\nHow efficient is this gzipped ASCII file anyways? If my memory doesn't fail me, the whole human genome in FASTA format after unzipping was several GB in size but the whole assembly gzipped will only cost you 900MB right now. Thats quite close to how big it should be if you stored it in a pure-bitwise way. Thats because gzipping will itself break the file into words, make a dictionary of them and store the file as indices, so the lack of information (in a literal Claude Shannon sense) in genomes in general aids in this packing.\n\nBut what if you just want to look at small amounts of DNA? Well then most of the time the ASCII text-files can be just fine, we handle only so much DNA at a time generally. Things are changing though, what with genome-analyzers spewing Terabytes of raw sequence data overnight. These machines generally use proprietary formats that store annotated sequence data but they probably do it in very basic bit-wise levels anyways to conserve the data.\n\nIf you're extremely curious, just google \"Blast.c\": thats the source-code of the standalone NCBI BLAST program and go through the structures and pointers they use to make the database and store it. They definitely use bit-level database storage mechanisms, otherwise they wouldn't be able to make indices that are so small as the BLAST program creates. I tried tracing the structures for the past 30 minutes though, but I guess I'm not geeky enough to figure out exactly how the structures are stored, so thank you really for wasting my evening and making me feel like shite :)",
"I would say that the \"standard\" file format for genomic strings would be [FASTA](_URL_0_).\n\nThough this format has quite a high redundancy (both the ASCII code and the strings themselves) that could be exploited to compress the sequence fairly well. It is more about usability than efficiency of space these days.",
"The answer is: it depends. \n\nOften plain text is used (in formats like fastq, fasta, sam, and others) for ease of manipulation and checking by humans.\n\nOther times, it's stored in a compressed format like bam.\n\nVery rarely do I actually see representations using a byte to represent two bases (4 bases per byte). This is often because sequence contains more than 4 letters. You might have Ns meaning no base could be called at that position, or Y for a pyrimidine (T or C). [See the IUPAC codes](_URL_0_)) for more on this.",
"DNA seen through the eyes of a coder or If you are a hammer, everything looks like a nail\n_URL_0_"
]
}
|
[] |
[] |
[
[],
[],
[],
[
"http://en.wikipedia.org/wiki/FASTA_format"
],
[
"http://en.wikipedia.org/wiki/Nucleic_acid_sequence#Notation"
],
[
"http://ds9a.nl/amazing-dna/"
]
] |
|
utwam
|
I work for the Kingston Historical Society in Ontario, Canada. This artifact was donated to us. What is it?
|
_URL_0_
The artifact was donated in 1971, but we can't seem to find our accession sheet for it (and even if we did, we doubt that it would provide much information). It appears to be made of cast iron and I would estimate it to be between 2 and 3 feet long (we didn't have a ruler handy when we visited the archives). Many of our artifacts are from the mid to late 1800s, so I would guess that this one is from that time period as well, but we really don't have any specific information on it. I apologise for having so little to go on, and any help identifying what this artifact is/does would be appreciated.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/utwam/i_work_for_the_kingston_historical_society_in/
|
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"Definitely a scale as HistGeek1 said. And it looks very much like [this E Whitfield hanging beam scale](_URL_3_).\n\nI found a few other examples of similar scales:\n\n[Scale 1](_URL_1_)\n\n[Scale 2](_URL_0_)\n\n[Scale 3](_URL_2_)\n\nThe descriptions suggest that these scales were used largely for tobacco and/or cotton. I don't imagine those were big crops in Ontario in the 1800s (though please correct me if I'm wrong) so the other two likely uses are weighing grain or meat.\n\nIf it is a Whitfield scale like the one in my first link, then [here's a little more information](_URL_4_) (ctrl+f \"Whitfield\" to find this entry):\n\n > Edward Whitfield & Sons advertised in Wrightson's Birmingham Directory for 1818 that they made 'scales, scale-beams, steelyards', as well as 'English and foreign weights of every description in brass and iron'. Their address was in Church Street. Edward Whitfield & Sons, 16 Church Street [1835 Pigot]. Samuel Whitfield (brazier and scale beam maker) of this address was granted a patent in 1809, as was William Whitfield in 1812 and 1814. Thomas D. Whitfield, weightmaker, at 15 Church Street [1847, 52 Slater]. Thomas Whitfield is also recorded at 23 Summer Row. The name T. & H. Whitfield has been seen on cast-iron weights of the usual 1850-90 style.\n\nSo, it looks like you have an 1800s agricultural or commercial scale, possibly made in England. Are there any distinguishing marks on the scale that might narrow that down even more?\n\nHope that helps."
]
}
|
[] |
[
"http://i.imgur.com/NigcS.jpg"
] |
[
[
"http://www.ebay.com/itm/ANTIQUE-HANGING-MEAT-OR-COTTON-SCALE-/261038318730?pt=LH_DefaultDomain_0&hash=item3cc718a48a#ht_500wt_1287",
"http://www.ebay.com/itm/Old-Antique-Cotton-Scale-Star-Design-Hooks-Cast-Iron-Tobacco-Original-Weight-VTG-/290690294801#ht_500wt_922",
"http://www.ebay.com/itm/Antique-Tobacco-Grain-Scale-/190686745952?pt=LH_DefaultDomain_0&hash=item2c65d0d560#ht_500wt_1287",
"http://www.ebay.com/itm/Anitque-E-Whitfield-Hanging-Beam-Iron-Scale-/261036616542#ht_500wt_1054",
"http://home.clara.net/brianp/namesqz.html"
]
] |
|
6csvnk
|
why do people say they will treat bombs as a terrorist attack until proven otherwise? isn't a bombing in nature an act of terrorism regardless of who did it?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6csvnk/eli5_why_do_people_say_they_will_treat_bombs_as_a/
|
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" > Isn't a bombing in nature an act of terrorism regardless of who did it?\n\nNo. Terrorism is using fear as a tool to try to force some sort of political or social change.\n\nIf the point of a bomb is to try to cause a group of people to comply with some sort of demand because they're terrified of being blown up if they don't, that's terrorism. But if someone is setting off a bomb just because they're crazy and want to kill people, that's not terrorism.\n\nIn short, whether or not something is terrorism is a matter of intent (much like whether or not something is first degree murder is a matter of intent).",
"\"Bomb\" is a general term, in a breaking news situation, used to be a placeholder for \"That loud sound everyone heard\", even though authorities have yet to confirm exactly what caused the reported noise and or damage.\n\n\nThe reason authorities treat it as a terrorist attack until proven otherwise is because if you don't know what's just happened, it's possible for it to happen again, and you want to be sure all of your helpers are on high alert.\n\n Also, in many governments, it allows for different agencies to be activated, some governments require a declaration of terrorism before some agencies can help. Look up: Buracracy, also: Vogons.\n\n\nBut I'm drunk on Bailey's Irish Cream after imagining what the parents and kids in Manchester might have went through, and I'm probably wrong.",
"1. In case it was not a deliberate bomb. Without knowing the full details yet, it could have been something else, like a pyrotechnics accident.\n\n2. If it was a bomb, there are other possible reasons besides terrorism, including suicide, homicide targeting a deliberate person or people, or other reason for destruction. The Dortmund (fixed, thanks /u/taversham) bus bomb was supposed to look like terrorism, but turned out to be someone trying to commit financial fraud.\n\nIt probably was a terrorist bomb, but the police want to be positive before officially calling it.",
"Keyword is **terror**ism. If you set off a bomb to spread fear, want to gain politcal/religious/ideological goals in a violent way, then that is an act of terrorism.\nOtherwise, you set off a bomb because it is fun for you to see death, doing it for the *lulz*, doing it as a prank then it is not terrorism. *(And oh boy, you do have some problems)*\n\nIt is more on the intention or objective of your actions.",
"Generally speaking, terrorism refers to violence with *ideological* motivations: political, religious, etc. Although bomb attacks usually are ideological in nature, they don't by definition have to be. Someone can commit a bombing for non-ideological reasons (maybe the bomb is an attempt to murder someone with whom the perpetrator has a personal dispute with.) \n\nTerrorism is not defined by tactics. If a man stabs ten people in a mall because he's a dickweed, that's not terrorism. If a man stabs ten people in a mall because he thinks it contribute to the overthrow of the government, then that is terrorism. \n\nIt's also worth mentioning that the word *terrorism* doesn't really define what terrorists do. The term implies that creating fear is terrorists' primary motivation, but this is generally not the case. Terrorists' goals vary depending on their motivations, but causing widespread terror in the minds of populations is generally more of a desirable additional effect than the main goal. The generally accepted modern definition of terrorism is violence or the threat of violence by non-state actors driven by ideological motivations. ",
"Because it is easy to step down an investigation, but much harder to ramp one up. Treating an explosion of undetermined, but suspicious, origin as a terrorist bombing means that any possible evidence recovered will be handled and logged in accordance with evidentiary procedure. Explosives experts will be among the first people combing through the debris, looking for any of the components of the explosive device.\n\nIf it is treated like an accident or something other than a criminal act, then it is entirely possible that valuable evidence may be lost or overlooked. Evidence might be handled or recovered in ways that make it useless for testing or inadmissible in a trial.\n\nIf you follow the most stringent investigative procedures, you know you're good. Worst case scenario is that you were too careful and exacting.\n\nThese are the same reasons suspicious fires are investigated as possible arson, and deaths of unknown origin are treated as possible murder. Until your investigation shows that the worst case scenario isn't true, you want to be certain that you aren't underdoing it.\n\nEDIT TO ADD: The reason it is treated as a terrorist bombing specifically, rather than any other type of criminal bombing, is because that gets the intelligence community involved. That's the critical difference between the investigation of a possible terrorist act and a 'regular' criminal investigation.",
"Others have already explained the latter part, what's required to classify as terrorism. The reason it's treated as a terrorist attack until they know better is because that's the worst crime, the police always assumes the worst when investigating because it's better to give it too high priority and downgrade it afterwards than wise versa.\n\nSimilarly if you put a house on fire they will file it as arson regardless if there were people in the house or not when the fire was lit. If it's later clear that there weren't they'll downgrade it.\n\nThen the news does the same because it makes for bigger head lines;)",
"Rational answer: What most people have already pointed out. Terrorism has a goal, usually political, and is much more about the fear it creates than the actual damage the attack inflicts. \nBut also, if a white person does it, it's usually a \"crime by a mentally unstable lone wolf\". If a brown person does it, it's \"terrorism\".",
"Terrorism is hard to define without being over or under inclusive, but we can give it aspects that help frame it and distinguish it from other acts of violence. Much of it comes down to the motivation and intended effect on target.\n\nFirstly, terrorism's kinetic target (that is the one physically damaged) might have little to no practical strategic value. Though irreplaceable people are sadly lost, these victims were not targeted because of their combat, political, or economic importance. The reasoning for this manner of kinetic target plays into the next framework.\n\nThe true target for a terrorist act is not the human casualties, or the damaged locations. The target of most concern to a terrorist is the witnesses. A terrorist operative might try to maximize physical damage during his act of violence, but it's part of his malignant goal to frighten survivors, media watchers, and policy makers. \n\nFinally, terrorism can generally fall into one of two categories. Either it is an attempt to upend the status-quo, or enforce it. In this regard, it goes beyond personal motives and into general policy. \n\nWhether or not an act of violence fits in these frameworks may not be immediately relevant for law enforcement investigations (but will be crucial in expanded countermeasures). A violent act of magnitude generally involves what Jacob Shapiro would call a \"Covert Violent Organization\" or CVO. The rules for managing a CVO are generally the same whether you are a spy ring, a drug cartel, or a terrorist group. Therefore, law enforcement might start with the same tools and methods in dismantling such a network. ",
"It might just have been someone who was trying to blow someone up for non-terrorism related reason.\n\nPeople may get terrorized but if the goal was insurance money or something that is not really terror.\n\nAlso not all explosion have to be somebody setting of a bomb. Gas lines explode all the time due to bad maintenance as do meth labs for similar reasons.\n\nSometimes you have industrial accidents and sometimes you have bombs that were perhaps at some point a tool of terror but now decades alter are just something people find when they dig a basement for a new building.\n\nSometimes people are just plain stupid.",
"People will also bomb places because of extortion - give us a million dollars or we'll blow the place up. This happened to a Las Vegas casino many years ago. Bombs have been blown up to get into bank vaults - a tool to commit a robbery, not terrorism. Bank robbers have put bombs on hostages to get their freedom when they are surrounded in the place they are robbing. Lots of examples. And sometimes you have explosions that are miscategorized as bombings. Natural gas explosions are the most common.",
"The movie, Patriots Day, is a good example of what happens when something is deemed terrorism.\nA whole different set of wheels start to turn when a crime is deemed terrorism. Different agencies get involved and personal liberties can be legally \"stretched\" in the name of National Security.",
"No, terrorism is violence with a political aim. That includes, for instance, Antifa, even though they don't kill anybody, but it doesn't include some whack job who sets off a bomb in a post office because his frozen dinner told him to.",
"Because humans notice patterns. A bomb is generally a terrorist attack, which is not an unreasonable conclusion. Maybe more sensitive people don't like the whole Islamic terrorism assumption. But, the bombing in Manchester was done by an Islamist... sooo... yeah. Patterns and track records.",
"Not if it has to do with a war and it was from a country not a person or a group of people ",
"Besides used as an act of violence, bombing (use of explosives) is also used in some areas to actually help humans, like demolishing old buildings, removing freezing surface from river, etc.",
"I think it's worth noting that not all explosions are bombs or intentional. They labeled this as terrorism before identifying the exact cause of the explosion ",
"There had been a [bomb attack on the German football team Borussia Dortmund](_URL_0_) where some people suspected a terrorism background (I recally some members of... a certain subbreddit... instantly blaming refugees) which turned out to be an act of \"ordinary\" greed.\n\nThe suspect had bet that the stock of the team would fall in the stock exchange (which it would have if players had become seriously wounded and/or killed)...",
"Since others in the thread have provided excellent responses on the nature of motivation versus method, as it pertains to your question, I just wanted to chip in an example I think will be relevant.\n\nBack in January 2011, a car exploded in close proximity to a number of defense department facilities (including the Pentagon). SWAT and bomb squads responded, and it was initially investigated as a possible attack. Turns out, it was a construction worker who had left an oxyacetylene torch in his trunk, which detonated (possibly due to temperature/pressure fluctuations caused by the cold). Within a couple hours, it was established what had occurred, and things backed down from \"terrorist attack\" to \"accident,\" but in those initial minutes of response, nobody had any way to know. [Here's a news article with updates and images](_URL_2_).\n\nOther things can also cause explosions, such as natural gas pipelines. For example, three 5-story buildings [were destroyed in NYC in 2015](_URL_1_) due to a gas pipeline problem, and another couple buildings there were [blown up in 2014](_URL_0_). Big explosions, but not bombs, and it took time to establish that. Until there is certainty of the cause, they will treat things as potentially the worst, so that they don't miss signs or put the public in greater danger by treating something less seriously than they should.",
"Because if white people do it, then it's a lone wolf with a psychology issue, not a terrorist and I really wish I wasn't being dead serious ",
"In answer to the second question - \"Isn't a bombing in nature an act of terrorism?\"\n\nAt one point, car bombs were a \"popular\" means for organized crime to get rid of people they wanted to kill.\n\nWere these bombs an act of terrorism? Or - more to the point, WHY were these people killed, and why were they killed using car bombs?\n\nYou could answer - these people were killed because they were doing something that organized crime was not happy about - they were informing, they were stealing from them, they were competing against them, etc. Is killing for this purpose an act of terrorism?\n\nAnd - why a car bomb? Obviously, the car bomb was used to send a message to other people - basically, that a certain organized crime entity did this, and let this be a warning to others. Would this make it an act of terror? Well - what about other means of killing that also \"send a message\"? What if the organized crime entity just had someone shot and then spray painted a message on nearby wall - this would get across the same point of the car bomb. Would this be terrorism?\n\nThe answer is that it boils down to what the definition of terrorism is. The accepted definition is an act of violence to accomplish a political goal. Of course, the line between regular assault/murder/etc. and terrorism can get blurred. Is a bank robbery an act of terror? Probably not. But what if the bank robbery was done by a terrorist group as a means to finance their other operations? This is where things get somewhat grey.",
"They need to find out if the person was brown first. If they were white they need to call it something else.",
"Have these sorts of attacks ever worked? That's my honest concern.\n\nBombings have been a thing for awhile now. Thinking back I don't think I've ever read \"welp they killed 13 more people, that puts us at 100 dead more so than last year. Better give them what they want!\"",
"What they mean is that they want to see if the attacker is Muslim and deserving of their disdain or just a mentally ill lone wolf white male who needs help. ",
"We only call it terrorism these days when it's Muslims. This is for entirely non-valid reasons of political ideology. If anyone who isn't Muslim bombs somewhere then it's \"terrorist-like\" activity. \n\nBasically it's racist as fuck mate. ",
"[FBI Definition of Terrorism:\n](_URL_1_)\n > The FBI further describes terrorism as either domestic or international, depending on the origin, base, and objectives of the terrorist organization. For the purpose of this report, the FBI will use the following definitions:\n\n > Domestic terrorism is the unlawful use, or threatened use, of force or violence by a group or individual based and operating entirely within the United States or Puerto Rico without foreign direction committed against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof in furtherance of political or social objectives.\n\n > International terrorism involves violent acts or acts dangerous to human life that are a violation of the criminal laws of the United States or any state, or that would be a criminal violation if committed within the jurisdiction of the United States or any state. These acts appear to be intended to intimidate or coerce a civilian population, influence the policy of a government by intimidation or coercion, or affect the conduct of a government by assassination or kidnapping. International terrorist acts occur outside the United States or transcend national boundaries in terms of the means by which they are accomplished, the persons they appear intended to coerce or intimidate, or the locale in which their perpetrators operate or seek asylum.\n\n_URL_0_\n\nThere is no single, universally accepted, definition of terrorism. Terrorism is defined in the Code of Federal Regulations as \n\n > the unlawful use of force and violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives(28 C.F.R. Section 0.85). \n\nHere is another definition used in the [Global Terrorism Database.](_URL_2_)\n\n > intentional act of violence or threat of violence by a non-state actor. In addition, two of the following three criteria also had to be met for inclusion\n\n > The violent act was aimed at attaining a political, economic, religious, or social goal;\n\n > The violent act included evidence of an intention to coerce, intimidate, or convey some other message to a larger audience (or audiences) other than the immediate victims;\n\n > The violent act was outside the precepts of International Humanitarian Law.",
"A bombing COULD just be a loner who hates everyone around him. There might not have been any philosophy or group that motivated him to bomb or that influenced his targets. Maybe he just wanted to die and at the same time send a message that society can't just ignore the mentally and emotionally troubled outcast. Conversely, terrorist bombing is all about drawing attention to something larger than the individual. The type of non-terrorist bombing I have been describing is more purely about drawing attention to the individual himself and how he was personally abused or neglected.",
"In general, if the motivation was political, then it's considered an act of terrorism.\n\nBut if it was some nut, who thought he was receiving messages from outer space through his teeth, then it wouldn't be considered terrorism. (As opposed to some religious nut, who thinks he's guided by messages from a book).\n\nI think the idea is, if it's terrorism, then society needs to be concerned that there is an organization behind it, which has to be dealt with. If it's a lone nutcase, then society doesn't have to be as concerned.",
"Well I think that the actual use of that word means they're looking for it to be a criminal action, rather than an accident. For example, there could be an explosion at a concert, whether it be a defective firework, or some sort of malfunctioning device. \n\nAnother reason is that when you describe terrorism, and that you're investigating an event as an act of terrorism, you really mean that you're now looking for other events that could be orchestrated along with that event. You don't look at it as a singular event but go in damage suppression mode, and think that this might not be the only event. ",
"No you got it wrong. People say they will treat EXPLOSIONS as terrorist attacks until proven otherwise. Explosions could happen because of a lot of different reasons.",
"Terrorism is motivated by the desire to instill terror in society, to make the society as a whole feel insecure, and to project an image of power or control by some group by causing mass or grotesque casualties. If a bomb is set off by someone without these motivations it may cause terror in the population based upon its effect but may not be part of a deliberate effort to do so. For instance some socially awkward teen who has been bullied by other kids may attempt to kill the whole group of them in a murder suicide by bomb. The intent is targeted at those individuals not the society as a whole. However your initial assumption that the bombings of a concert venue is almost certainly an act of terror is well founded. It would be a highly exceptional situation for it to be anything other. Investigators and politicians want to avoid looking like they rush to judgement in these cases so they will be over cautious in their language. For instance the use of the term \"person of interest\" rather than \"suspect\". We all know that for practical purposes this person is a suspect. But phrasing this cautiously helps with the criminal proceedings if it comes to that where it reduces the possibility that the defense can claim a rush to judgement where all evidence was collected and funneled towards an assumption that the defendant was the guilty party and that a myriad of other potential suspects were not sufficiently investigated as a result. The claim would be that the evidence seems damning because collection and interpretation were both biased by a presupposed guilt. ",
"Bombing, in and of itself, is not a terrorist attack.\n\nThe definition of terrorism is \"An attack on a civilian population for political or ideological goals\"\n\nTo be terrorism, it generally has to meet at least two major criteria:\n\n1. The targets are civilians / noncombatants\n2. The attack has a goal beyond \"lets kill people!\"\n\nThe point of terrorism is to use actual attacks or threats of attack against civilians to intimidate someone (usually a govt, but sometimes smaller entities like religious organizations or corporations) into doing something (release X high-value prisoner, remove troops from Y region, send money to Z organization).\n\nFor real world examples: The Boston Marathon bombing qualifies as an act of terrorism, as the brothers who conducted it \"wanted to defend Islam from the U.S\" (targeted civilians, goal is to get US out of Afghanistan by making Americans fear an attack at home).\n\nOn the flip side, Al-Qaeda bombing a military convoy in Afghanistan is NOT an act of terrorism, it is a standard practice of warfare against uniformed troops.\n\nFor an example of a bombing that would NOT qualify as terrorism (I cannot easily find any, as searching for \"bombing\" produces hundreds of news articles about terror attacks) consider the following:\n* Disgruntled worker fired for poor performance\n* Decides if he's going down, he'll take the bosses with him\n* Plants an explosive in a conference room, kills the company executives\n\nThis would NOT be an act of terrorism, but rather one of multiple-murder where the weapon is a bomb. While this is an attack against civilians, it does not aim to cause another party to take a desired action; The goal in this scenario is simply to get revenge by killing the people this hypothetical worker sees as responsible for his misery.",
"There is a difference between murder and terrorism. If it's not aimed at a specific person and is motivated by politics, or religion, its terrorism. ",
"Terrorism is supposed to refer, technically, to attacks that are designed to spread panic and confusion. Loss of life isn't as important as having everyone trembling, and taking counter-productive measures in the hope of protecting themselves. Typically, terrorists have a cause or motivation they see as being greater than themselves, which is how they justify taking lives. Often, they're regarded by some as \"freedom fighters\" or \"holy warriors\" or something else more positive. \n \nDuring World War 2, French and Polish resistance fighters used what we would call terror tactics today. \n \nIn popular use, \"terrorism\" has been applied to more or less any attack that scares people, regardless of whether or not that was the intention. This is more of a popular application (like referring to someone convicted of manslaughter as \"a murderer,\" or anyone killed by another human being/agency as \"murdered,\" despite murder being a specific legal term).",
"Not necesarily. Imagine you want to kill somebody, say Greg, and you have access to explosives or the skill to craft one, and you know that Greg is going to that concert tonight. If you're crazy enough to commit to killing Greg with a bomb, you're probably crazy enough to not care about collateral damage too.\n\nSo in that case it's not terrorism, it's assassination with collateral damage. After all a bomb's main purpose is destroying and killing, and terror of the masses is a byproduct of that.\n\nTreating a bombing as a terrorist attack means first that we think that someone wanted as primary objective to cause terror, and second that we'll use our resources on looking for terrorists. For example we won't look for serial killers or people with dementia who for some mad reason made a bomb go off, we're looking for radical people who want to cause terror, or terrorists.",
"Others have mentioned that terrorism could be motivated for some reason, but that's not the key factor. The goal of the bombing is what makes terrorism. \n\nThere could be political, social, religious, etc... motivations for the terrorist act. What makes terrorism though, is the goal to spread fear. You could do terrorism just for the sake of spreading fear and nothing else, and that would be terrorism. There may be motivation for such an attack (you attack my country, people, culture, religion, etc...) but that just separates the different types of terrorism, not what it actually is/defines it.\n\nManchester could be a terrorist attack because the goal was to scare children and their parents. Make them fear attending events, experience culture. Make them doubt and be alert as they experience life. There may be religious motivation for it, making it then Islamic Terrorism, but even without a motivation it could still be terrorism.",
"If a non white person did it, it's terrorism. If a white person did it, it's a kid who made a mistake. ",
" > **Terrorism**: *The unlawful use of violence and intimidation, especially against civilians, in the pursuit of political aims.* \n > merriam-webster \n \nFor it to be a terrorist attack it would be in the pursuit of political aims. There can be bombings carried out by people who do not have political aims. But in this time it is more likely and is more widely assumed to be orchestrated or influenced by larger group than the individual who committed the act.",
" > Why do people say...\n\nWho specifically? If you're quoting someone (i.e. politician or chief of police) - it would just be a matter of protocol; a routine... a readiness/alert policy, or *wtf do I do when something bad happens*.\n\n > isn't a bombing in nature an act of terrorism\n\nNo. detenating a bomb is not act of terrorism. Not by itself alone (Example: detonating a bomb to carve highways and tunnels through mountains.) \nHowever, the use of explosives falls within a fundamental aspect of terrorism; it would be a 'force multiplier'. \n\nThe use of violence (w/ bomb or not) subjected towards an intended target/audience is indeed an act of terrorism. The latter part is crucial, and another force multiplier. There's several of them but I'll spare the lecture. \n\nThink of terrorism as a strategy, not an ideology. It is the anti-thesis of peaceful protest. That is really what determines/differentiates acts of terrorism and acts of violence.",
"Most people in this thread misdefined terrorism, which is all you need to answer this question: \n\nTerrorism is the act of using force/threats of force in order to effect political change in the target audience - an attempt to scare the civilian population not cause physical damage to the target you are attacking.\n\nSo literally, most bombings are not acts of terrorism, however, attacks on civilian populations largely are terrorism. This is why I think people assume these types of events to be malicious. At a concert where there is no military or political target, it is certainly an act of terrorism.\n\nEveryone misuses the terms terrorism and terrorist (one who engages in terrorism) though, so colloquially this nuance is lost. ",
"If I bombed a concert b/c I'm trying to strike fear or intimidate a group of people b/c I hate Western culture, that's terrorism. \n\nIf I bombed a concert b/c I don't like Arianna Grande and was hoping to kill or injure the singer, that's attempted murder, but probably isn't actually terrorism. \n\nTerrorism needs to have a political/religious/nationalism purpose/drive.",
"It depends on the source/intent of the explosion and definition of \"bomb\". Bombs have been made accidentally - either because of carelessness, recklessness, ignorance, or complete chance. Under the right circumstances, a bag of flour is a suitable bomb. But you'd hardly call someone simply buying groceries a terrorist. ",
"Explosions aren't only caused by purposeful bombings. I'd agree that most purposeful could be construed as terrorist actions (actions who's primary objective is to kill others, and secondary objective is to cause fear in it happening again).\n\nBut some explosions aren't bombs. What if this bombing had been an act of negligence rather than murder. Say a gas pipe fracturing during the concert, then igniting at the worst time.\n\nI'm fine with authorities assuming all explosions, especially those with body counts, we're terrorist bombings until proven otherwise. So you shut down bridges and airports, you begin investigating during the triage of the human cost.",
"Story time.\n\nI used to live in a very small city and couldnt really get out of there. I had no car, not even money for a bus ticket.\n\nSo one sunny saturday morning I sit outside and smoke a cigar as a REALLY loud explosion shatteres the street. People stepped out, ambulances, firefighters and police cane within a few minutes.\n\nIts not like america, our houses usually have multiple tenants so no one really knew what was going on and just as I was talking to someo.... - OH MY GOD! THAT HOUSE IS ABOUT TO COLLAPSE! HOLY FUCK WHAT!?\n\nOk. It didnt collapse. But the explosion, which occurred inside of the house, destroyed the stairway inside and actually MOVED an entire wall, which was going from roof to cellar by 5 centimeter and split the outer wall.\n\nThey rescued everyone in the house through the windows. Nothing burned.\n\nYou know explosions are most likely terrorists because its very effective damage and bombs can kill more people on short time than guns, and terrorists have very little time.\n\nBut in this case it, which is rare, was not a terrorist. It was some stupid idiot who dried firework in the drier. And they eventually exploded!\n\nNo terrorists. ",
"The motives are pretty much the only thing that defines whether some sort of attack is \"terrorist\" or not. You can perform a \"crowd punching\" and it could be considered a terrorist attack if you do it with the right motives",
"If it WAS a bomb that exploded, then yea, that pretty much is always terrorism.\n\n\nWhat if it was just a gas leak that got sparked somehow though?",
"Terrorism, AFAIK, is more interested in disruptions than they are in destruction - i.e they bomb to make threats, not the other way around. \n\nAn attack like this will usually be followed by multiple threats being called in, most if not all of which will be responded to (and publicized). \n\nIf a group can make 20 to 50+ phone/email/social media threats for every actual attack, then doing something as resource intensive as an attack is something that, to them, is worth doing. ",
"In a terrorist attack, the bomb is a method to a means. Never will a terrorist attack accomplish it's final goal with the actual bomb. The terrorist wins after the dust of the bomb is settled down. The next day when people look over there shoulder for another attack. Perhaps they change the way they used to live because of it. The idea of terrorist attacks is to get the Public to feel differently after the attack. \n\nLet's say some girl found out her husband was cheating on her with his secretary. A well placed bomb will kill them both. Sure it might kill others but that's not even factored. This women just wants revenge on her husband and his lover. The bomb can accomplish the final goal. To end the lives of the husband and lover.",
"No, terrorism is a tactic of using violent methods to inflict terror in a population, usually in order to encourage some political change.\n\nA guy running into a crowd in the name of god is an act of terror, a guy driving into a crowd because he's drunk isn't.\nA car blowing up in a mall to avenge the execution of a political leader is an act of terror, a car blowing up as part of a hit by organised crime isn't.\n\n",
"Terrorism uses the attack to cause fear, to work towards an ideological, religious, or political goal. \n\nYou could bomb a bunch of people with no goal in mind.",
"Because a lot of white people don't think other white people can be terrorists. In this case \"proven otherwise\" means \"until we prove it isn't a Muslim\".\n\nIt's small, angry people looking to justify their hate.",
"I don't agree with those lengthy nit picking apologist definitions itt. \n\nAll bombings are terrorist attacks. \n\nAnd it's not a question of intention, but results. The result is always fear/destruction/death.",
"There was an explosion. They hadnt yet determined whether it was actually a bomb or something else.",
"I think it should be asked why we don't call all explosions \"acts of terrorism\" because for the majority of cases, right when something like this happens it's not certain whether it was a bomb that went off or something just exploding due to something else. The media is very apprehensive with labeling something as a bomb when it has yet to be confirmed. However, if it is shown that a bomb was exploded with the intent to kill people on domestic soil then you can instantly label it an act of terrorism regardless of motive. ",
"*Explosions* aren't uncommon. Chemical reactions, volatile gasses, high-speed collisions, etc. \n\n*Bombings* aren't necessarily the exclusive domain of terrorists. Controlled demolitions are common in road construction, taking down condemned buildings etc. They are also have military applications, such as destroying supplies, infrastructure, and enemy combatants. Even criminal intent (opening a safe) is different from terrorist intent.\n\n\nNow, when you hear people say \"Terrorist Bombing Attack\", it refers to a specific tactic designed to cause death and injury to civilians, with the goal of destabilizing and destroying society. \n\nAnd not to put to fine a point on this, \"Terrorist Attack\" specifically means **ISLAMIC** terrorist attack. It often goes without saying, because 99 times out of 100, it's MUSLIMS who are to blame. (And usually, Muslims who are the victims)",
"Violence is only ok if sanctioned by the State. For example, when the U.S. bombs a school full of children with a drone, it's ok. When a shooter is killed by an explosive device made to look like a cell phone, it's ok. Philosophically it's disgusting and repugnant, but that's the truth of it.",
"I think you mean they treat explosions as terrorist attacks. Explosions could be caused by things like gas leaks or other non-bomb related things. But treating these situations like terror attacks is the smartest way to go about it in case it is a terrorist attack- there is a higher possibility of catching the attackers before they do more damage. If it is something more innocent then no harm, no foul.",
"Might be that they mean \"an explosion of an unconfirmed origin.\"\n\nOr possibly, but unlikely, an unexploded ordinance from a previous armed conflict.",
"Haven't you head? Islam is the enemy so it gets the blamed for everything. Americans who bomb are just crazy. ",
"Last month three bombs exploded in Germany next to the team bus of a top soccer team. They had a lot of luck, only one player was injured. The attacker left a letter of confession near the bombs, saying that this was done by the Islamic State. Clear case of terror, one could think.\n\nTurns out the attacker had borrowed money from a bank and then placed bets that the stock price of the soccer team stock company would go down. He wanted to kill as many players as possible, because players are literally the most valuable asset of a soccer team. He had nothing to do with Islamic State, was not even a Muslim, and had written the letter to divert suspicion. So in reality he did it because of financial interests, the terror intention was faked.\n\n_URL_0_",
"A bomb could be a deliberate act of aggression from one country to another.\n\nAn act of Terror, is violence or the threat thereafter which is performed to force a political or religious message/ideology.\n\nExample: Threatening to harm people who refuse to convert to your religion or political system. ",
"Yeah. This is pretty mind blowing to me personally. If a person from an Islamic country does something it's terrorism. If a white Christian shoots up a planned Parenthood it's a \"shooting\" and they stay away from the terrorism term . When in fact it's all terrorism."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Borussia_Dortmund_team_bus_bombing"
],
[
"https://en.wikipedia.org/wiki/2014_East_Harlem_gas_explosion",
"https://en.wikipedia.org/wiki/2015_East_Village_gas_explosion",
"https://www.arlnow.com/2011/01/11/breaking-news-car-explodes-in-penrose/"
],
[],
[],
[],
[],
[],
[],
[
"https://www.law.cornell.edu/uscode/text/18/2331",
"https://www.fbi.gov/stats-services/publications/terrorism-2002-2005",
"http://www.start.umd.edu/gtd/using-gtd/"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"http://www.dw.com/en/dortmund-soccer-team-bus-attacked-for-financial-interests-prosecutors-report/a-38860842"
],
[],
[]
] |
||
jaspg
|
Why do people say there is a connection between music and mathematics?
|
I never understood it. Does it have something to do with Fourier? Or is it because of the pattern of frequencies?
|
askscience
|
http://www.reddit.com/r/askscience/comments/jaspg/why_do_people_say_there_is_a_connection_between/
|
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"Watch / hear this:\n\n_URL_0_\n\nAny more questions?",
"Music is structure with soul, and math is the study of structure! \n\n... but music is felt so intuitively that it can seem a bit far-fetched to say that it's really deeply connected to something academic like mathematics. But really, even in a musicologically \"simple\" piece like a folk song with just the basic I-IV-V chords, when you play it and listen to it, there's so much mathematical stuff going on in the rhythm, harmony, and melody.\n\nIf you listen closely to almost any drum rhythm you'll hear so many different subdivisions, syncopations, the whole thing is just a complex pattern that is arithmetically coherent. If the song skips a beat or does anything weird with the rhythm, it's shocking how effective your mind is at detecting it.\n\nAnd harmonies are also just teeming mathematical things, governed by the same equations that govern waves in water and electromagnetic fields. The ear's capacity to understand frequencies and harmonies is pretty remarkable. I've heard evolutionary explanations that refer to the need to differentiate vowels, but I dunno. Above the immediate level of one heard chord, there's the whole field of music theory to describe the structures used in composing chord sequences, and they turn out to be quite elegant mathematical structures indeed.\n\nMelodies play around the harmonies and need to make sense from that perspective, and to be melodically interesting, they have to manifest sequential patterns that are understandable yet surprising...\n\nWhat I find most fascinating about the whole thing is how much music is about, um, implying a certain mathematical structure, yet deviating from it, being playful with it, suspending it, etc. That's the raison d'etre of modern jazz, and it's all over the place in baroque and classical music: disharmonies, weird syncopations, suspended final chords, twists, blue notes, etc, etc.",
"The frequency of each note is 2^1/12 higher than the previous note. Every 12 notes (octave) you get a perfect doubling of the frequency. That means that chords are basically just note pairings with common factors.",
"Most music is arranged in complex patterns, determined by mathematical rules. Think of it the same way that you think of regular patterns in numbers. If you take the set of 1-100 and alternate adding 5 and 10, you get the pattern (5, 15, 20, 30, 35, 45...). That set of number might even seem pleasant or \"well-formed\" to you, and this is because you see the inner pattern. Now we can do something similar with the musical scale. \n\nWe've selected a spectrum of sound that makes sense for humans (similar to how we started the number pattern only from 1-100 instead of starting with 4543987) and we've divided it into singular, definite notes. We have A, B, C, etc and we also have their in-between notes which are sharp (higher than x) or flat (lower than x). The scale has 12 notes, and that scale is repeated 8 times along the keyboard called octaves. Now, music is created in the same way we create number patterns, but with its own pattern types. Our minds recognize the patterns formed along the scale and the more the different types of order that it creates sound pleasant to us. That's how musicians have an idea what sort of music will sound good even before it is played. They understand the patterns they can use to make it.\n\nHope that makes sense. I kinda did an ELI5. I highly recommend reading Godel Escher Bach to anyone interested in music, math, and patterns.",
"Mathematicians have studied music, and musicians have studied mathematics for some time. The great mathematician Leonhard Euler attempted to create a mathematical theory of music, and that was a few centuries ago.\n\nModern approaches include applying geometry and group theory to music. This approach is interesting because one of the essential features of music is its use of symmetry to create structure.\n\nThere was a paper I want to link, but it' behind a pay-wall on Science. There was a talk a couple of months ago at my university by a guy who studies music this way. It's sort of interesting.",
"If you look closely enough, you can find a way of connecting mathematics with anything.",
"I know this is childish and stupid, but [Donald Duck in Mathmagic Land](_URL_0_) has a really good music vs. math explanation. ",
"Many of the commenters here have pointed out that since music is a sound and since sound is described in mathematical terms then music is thus inherently mathematical. While this is true, these people aren't really giving music enough credit.\n\nMusic is more than just a wave that is oscillating at various frequencies at various times; it has higher patterns too. For example, a piece of music will almost always progress from one chord to another as it plays. It does not do so randomly, but along one of many patterns depending on things like it's key and the desired emotional impact. At a higher level still, a fugue has several different voices singing variations on the same tune at different frequencies at different times, but not all frequencies and timings are permissible since they must (or rather _should_) be harmonious in a way that is dependant on the notes of the tune.\n\nThis \"higher structure\" of music is just as mathematical as the maths of sound, but more subtle and interesting.\n\nI can't let this comment go without recommending that you read \"Gödel, Escher, Bach, An Eternal Golden Braid\" by Douglas Hofstadter. The core of the book is an exploration of Gödel's Incompleteness Theorem and the author's thoughts on intelligence, but Hofstadter lays this out by relating the necessary mathematical concepts to analogous concepts found in music and art.",
"Watch / hear this:\n\n_URL_0_\n\nAny more questions?",
"Music is structure with soul, and math is the study of structure! \n\n... but music is felt so intuitively that it can seem a bit far-fetched to say that it's really deeply connected to something academic like mathematics. But really, even in a musicologically \"simple\" piece like a folk song with just the basic I-IV-V chords, when you play it and listen to it, there's so much mathematical stuff going on in the rhythm, harmony, and melody.\n\nIf you listen closely to almost any drum rhythm you'll hear so many different subdivisions, syncopations, the whole thing is just a complex pattern that is arithmetically coherent. If the song skips a beat or does anything weird with the rhythm, it's shocking how effective your mind is at detecting it.\n\nAnd harmonies are also just teeming mathematical things, governed by the same equations that govern waves in water and electromagnetic fields. The ear's capacity to understand frequencies and harmonies is pretty remarkable. I've heard evolutionary explanations that refer to the need to differentiate vowels, but I dunno. Above the immediate level of one heard chord, there's the whole field of music theory to describe the structures used in composing chord sequences, and they turn out to be quite elegant mathematical structures indeed.\n\nMelodies play around the harmonies and need to make sense from that perspective, and to be melodically interesting, they have to manifest sequential patterns that are understandable yet surprising...\n\nWhat I find most fascinating about the whole thing is how much music is about, um, implying a certain mathematical structure, yet deviating from it, being playful with it, suspending it, etc. That's the raison d'etre of modern jazz, and it's all over the place in baroque and classical music: disharmonies, weird syncopations, suspended final chords, twists, blue notes, etc, etc.",
"The frequency of each note is 2^1/12 higher than the previous note. Every 12 notes (octave) you get a perfect doubling of the frequency. That means that chords are basically just note pairings with common factors.",
"Most music is arranged in complex patterns, determined by mathematical rules. Think of it the same way that you think of regular patterns in numbers. If you take the set of 1-100 and alternate adding 5 and 10, you get the pattern (5, 15, 20, 30, 35, 45...). That set of number might even seem pleasant or \"well-formed\" to you, and this is because you see the inner pattern. Now we can do something similar with the musical scale. \n\nWe've selected a spectrum of sound that makes sense for humans (similar to how we started the number pattern only from 1-100 instead of starting with 4543987) and we've divided it into singular, definite notes. We have A, B, C, etc and we also have their in-between notes which are sharp (higher than x) or flat (lower than x). The scale has 12 notes, and that scale is repeated 8 times along the keyboard called octaves. Now, music is created in the same way we create number patterns, but with its own pattern types. Our minds recognize the patterns formed along the scale and the more the different types of order that it creates sound pleasant to us. That's how musicians have an idea what sort of music will sound good even before it is played. They understand the patterns they can use to make it.\n\nHope that makes sense. I kinda did an ELI5. I highly recommend reading Godel Escher Bach to anyone interested in music, math, and patterns.",
"Mathematicians have studied music, and musicians have studied mathematics for some time. The great mathematician Leonhard Euler attempted to create a mathematical theory of music, and that was a few centuries ago.\n\nModern approaches include applying geometry and group theory to music. This approach is interesting because one of the essential features of music is its use of symmetry to create structure.\n\nThere was a paper I want to link, but it' behind a pay-wall on Science. There was a talk a couple of months ago at my university by a guy who studies music this way. It's sort of interesting.",
"If you look closely enough, you can find a way of connecting mathematics with anything.",
"I know this is childish and stupid, but [Donald Duck in Mathmagic Land](_URL_0_) has a really good music vs. math explanation. ",
"Many of the commenters here have pointed out that since music is a sound and since sound is described in mathematical terms then music is thus inherently mathematical. While this is true, these people aren't really giving music enough credit.\n\nMusic is more than just a wave that is oscillating at various frequencies at various times; it has higher patterns too. For example, a piece of music will almost always progress from one chord to another as it plays. It does not do so randomly, but along one of many patterns depending on things like it's key and the desired emotional impact. At a higher level still, a fugue has several different voices singing variations on the same tune at different frequencies at different times, but not all frequencies and timings are permissible since they must (or rather _should_) be harmonious in a way that is dependant on the notes of the tune.\n\nThis \"higher structure\" of music is just as mathematical as the maths of sound, but more subtle and interesting.\n\nI can't let this comment go without recommending that you read \"Gödel, Escher, Bach, An Eternal Golden Braid\" by Douglas Hofstadter. The core of the book is an exploration of Gödel's Incompleteness Theorem and the author's thoughts on intelligence, but Hofstadter lays this out by relating the necessary mathematical concepts to analogous concepts found in music and art."
]
}
|
[] |
[] |
[
[
"http://wheelof.com/whitney/"
],
[],
[],
[],
[],
[],
[
"http://www.youtube.com/watch?v=-6w9VYbptPQ"
],
[],
[
"http://wheelof.com/whitney/"
],
[],
[],
[],
[],
[],
[
"http://www.youtube.com/watch?v=-6w9VYbptPQ"
],
[]
] |
|
1gxhcs
|
Dear AskHistorians I am really interested in Urbanization can you lead me to books or articles that can give me more insight into what leads to urbanization, what are the results of urbanization and anything else on the topic of Urbanization?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1gxhcs/dear_askhistorians_i_am_really_interested_in/
|
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"text": [
"Well, if you haven't read Jane Jacobs, that's a must."
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[] |
[] |
[
[]
] |
||
4skj02
|
Which one provides more energy? Protein or Carbohydrate?
|
My teacher told me that, if you have a lojg marathon then you should eat proteins because carbohydrates get burn off quickly. But I don't understand how proteins will be able to provide energy?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4skj02/which_one_provides_more_energy_protein_or/
|
{
"a_id": [
"d5abzqr"
],
"score": [
4
],
"text": [
"Both protein and carbohydrates have about the same available energy density, 4 kCal/g, but protein metabolism tends to be slower because the body holds onto amino acids for its own protein synthesis and only breaks them down as an energy source when other sources are low.\n\nDifferent amino acids are introduced into the carbon pathways in different ways depending on their class composition. Several can directly or indirectly be converted to pyruvate for the Krebs cycle, while others form Krebs intermediates like oxaloacetate and succinyl-coA. [Here's](_URL_0_) a good overview of amino acid metabolism.\n\nFats can be both more easily stored than carbs and more easily used when needed than proteins and they have a much higher energy density (9 kCal/g), so I would think marathon runners would prefer fats ahead of a run."
]
}
|
[] |
[] |
[
[
"https://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/aacarbon.htm"
]
] |
|
yz51p
|
My parents are convinced that they need to start drinking ionized water because they say it balances your pH. Is there any science behind the benefits of drinking ionized water or high pH water?
|
askscience
|
http://www.reddit.com/r/askscience/comments/yz51p/my_parents_are_convinced_that_they_need_to_start/
|
{
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"c6036si",
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6
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"text": [
"It's nonsense. See this post from a little while ago _URL_0_\nIt certainly won't increase the pH of you're body. The pH of your body is tightly controlled to be at the optimum pH for all your enzymes. Even if it did somehow raise your pH it wouldn't be good for you. In fact if it's raised enough you will die. ",
"No, for a few reasons. \n\n1. You do not want to significantly alter the pH of your body. Any deviation from the normal values of ~7.35-7.45 is bad.\n\n2. Nothing you drink is going to affect you blood's pH anyway. The stomach is highly acidic so any alkaline stuff you drink is just going to alter that slightly and temporarily.\n\n3. You already balance your pH on your own. Your body has buffer systems in place, especially in the blood. This means that the pH is controlled in a certain range; if you try to push it out of that range it will chemically \"push back\" to get back in the proper range."
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/askscience/comments/ronun/alkaline_water_fact_or_fiction/"
],
[]
] |
||
c1ckun
|
how do wasps build nests?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/c1ckun/eli5_how_do_wasps_build_nests/
|
{
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"ercbi6e"
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"text": [
"Queen chews on the wood, mixing it with saliva, turning it into paper like pulp. Once she chooses a location, helper drones arrange pulp into hexagonal tubes.",
"They find exposed wood (generally from dead trees or fallen branches AFAIK), chew it off and mix it with saliva to make a pulp. Then they spit that up at the nest and mold it into the shape they want.\n\nThere are also some species of solitary wasps that build little hollow domes out of mud on the ground near water, like a river bank."
]
}
|
[] |
[] |
[
[],
[]
] |
||
xd83g
|
If the Higgs' Boson is proven to be a particle/field that gives a particle mass, does mass then become a vector quanitity?
|
I read "The 'everything you need to know about the Higgs boson' thread," but I guess it just didn't answer my question (and if it did, I couldn't understand it or couldn't put pieces together).
And if mass does become a vector quantity, do we have to re-work everything?
|
askscience
|
http://www.reddit.com/r/askscience/comments/xd83g/if_the_higgs_boson_is_proven_to_be_a/
|
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"text": [
" > And if mass does become a vector quantity, do we have to re-work everything?\n\nYou should have known that the answer to that question would definitely be no. The Higgs model was created to explain what we observe, including that mass is a scalar quantity. Any theory that explains mass must include within itself the statement that mass will be a scalar.\n\nIn general, any theory that would require us to \"re-work everything\" can be dismissed immediately."
]
}
|
[] |
[] |
[
[]
] |
|
rllvv
|
What is this?
|
It says ammonite, but they have this _URL_0_ and then they have some that look like a snail shell almost, just wondering if they were both shelled cephalopods or if it was something else
|
askscience
|
http://www.reddit.com/r/askscience/comments/rllvv/what_is_this/
|
{
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"text": [
"Yes, shelled cephalopods. Predatory mollusks similar to the nautilus.\n\nThe picture that you showed is of a fossil ammonite. These particular ones are among the most abundant fossils on Earth. Many (like the one in the picture) are found in metamorphosed calcite, e.g. marble, and are often used for interior decorating as counter-tops and floors. ",
"That sample is an orthoconic nautiloid, not an ammonite. "
]
}
|
[] |
[
"http://www.imgur.com/Y1y1x.jpg"
] |
[
[],
[]
] |
|
1dpe7p
|
What to study to show an "in depth knowledge of" modern China. x-post r/china
|
I am an American history major and am trying to determine what to focus on for my second field. Modern China seems like it would distinguish me from all my peers who study Latin America or Ancient Europe. I want to study and see if studying China is something that I will really enjoy. Books and resources of history through modern would be a great help.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1dpe7p/what_to_study_to_show_an_in_depth_knowledge_of/
|
{
"a_id": [
"c9smb90"
],
"score": [
3
],
"text": [
"\"The Search for Modern China\" by Jonathan Spence is the classic text for an intro to modern chinese history. "
]
}
|
[] |
[] |
[
[]
] |
|
38pxyq
|
the blind spot while driving motor vehicles
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/38pxyq/eli5_the_blind_spot_while_driving_motor_vehicles/
|
{
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"text": [
"What exactly do you want to know? if it is really this basic a question you could just google it",
"As distinct from your eye's blind spot where your retina is?\n\nIt's an area between the edge of the wing mirror's field of view and your normal periphery when facing forward. You \"check your blind spot\" by turning your head slightly behind you to make sure something isn't in this area.\n\nLPT - you can position your wing mirror to minimize your blindspot.",
"Just have a friend walk around your car and notice that they will leave your peripheral vision before they appear in any of the mirrors. The exact size and shape of the blind spot depends on the size, shape, and positioning of your mirror."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
4313ue
|
Could a nuclear reactor operate in space?
|
If we had a large space vessel that required vast amounts of electricity, could a nuclear reactor operate in space? It's my understanding nuclear reactors need to dissipate a high level of heat, is this possible in space?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4313ue/could_a_nuclear_reactor_operate_in_space/
|
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"text": [
"Yes and no. If you're taking a larger scale fission reactor (like a smaller version of a power plant, or a submarine) yes, but you would need a very large ship to deal with it... It has the nasty problem of being both very heavy (hard to get into orbit and accelerate) and makes the ship very heavy as you need both massive heatsinks (the ISS uses an ammonia based coolant exchange to radiate the heat it produces, you'll be scaling that up a ton!) And even heavier because you have to include large masses of shielding (only thing you can use is concrete, heavy metals, or depths of water... All of which hugely increase your cost of fuel to launch and accelerate the craft...\n\nIf we're going to stretch the definition of nuclear power a wee bit... Many space probes and landers use a plutonium puck for power. This is how voyager has been running for 40 years now, and the curiosity rover. It works by using the heat (and in some cases beta decay capture, though that's a much more complicated process) to drive a thermocouple. Rather than a big hefty reactor at 1000 degrees driving a turbine with a fluid phase change, you just need a couple degrees temperature gradient, and the fuel lasts a very very long time because it's sub critical.\n\nThe reactor isn't out of place in space, if you were making a manned craft for deep space, it's going to be huge and have massive energy requirements, and the size needed for solar power at distances of the outer planets might make the costs of the reactor and its draw backs worth while. (Since at 2AU you need 4x the surface area to generate the same power... And at jupitors about 4 AU orbit the ISS would have to be 16 times bigger to collect the same energy... Eventually the weight of solar panels is greater than the reactor and shielding.\n\nTldr: if the mission and craft need it, it makes sense, otherwise alternatives can be used.",
"Yes.\n\nMany, many spacecraft and rovers have used RTGs. They are nuclear but not technically nuclear reactors because they use passive decay heat instead of sustaining a chain reaction.\n\nThe United States demonstrated an ultra-compact nuclear reactor with the [SNAP program](_URL_0_). The Soviet Union also launched several fission-powered satellites, such as [Kosmos 954](_URL_1_) and the [ROSAT program](_URL_2_). Very large nuclear-powered vessels will likely be covered in gossamer radiator fins many times bigger than the vessel itself to dump adequate amounts of heat.\n\nWe really should find a new use for all the derelict nuclear reactors currently orbiting Earth. ",
"First lets clarify a few things:\n\n1) Nuclear reactors don't technically make electricity, they produce heat which makes steam, which runs a turbine, which powers a generator which makes the electricity. In this sense the system generating electricity doesn't really care where the heated steam comes from, it could be from coal, natural gas, or in this case nuclear and as such you question is really would a Rankine cycle work in space? (You have just been introduced to the first of several terms you should look up)\n\n2) Work is created by moving energy from areas of high concentration (high enthalpy), to areas of low concentrations in a way which is useful, expanding and cooling a gas through a turbine, for example. That is to say you need a sink, or low temperature/energy in order to generate work, there has to be a temperature/pressure differential between two areas.\n\nSo now we get to your question, would a turbine, that is the Rankine cycle work in space. Is there a sink or way to get rid of heat from the cycle and the answer is YES, there is! But how, where is the energy going? \n\nElectromagnetic radiation, specifically black body radiation, parts of which are also known as light and heat. Everything with a temperature is radiating energy with specific characteristics (which I won't go into). Our sun, for example, radiates light and heat from fission reactions in its core which is hotter than it's surface.\n\nSo how do we know what that temperature will be? Well turns out black body radiation dissipates according to the Stefan–Boltzmann law an, that is as a function of surface area, ~~so if the outside of the space ship is 4 times larger than the surface area of your nuclear material, then the outside of the ship will be roughly 4 times cooler and before other scientists jump on me yes this is an ideal case and therefore an approximation.,~~ The equation is j=AsT^4 where j and s are constants so we can create the equation A1 s T1^4 = A2 s T2^4 or T2=(A1 T1^4 /A2)^1/4 From here I can go into how this affects efficiency, but I think my post is long enough as it is.\n\nEdit: words and redid my math, whoops\n",
"An atomic submarine's water cooled reactor system would not work with zero gravity because the Steam Generators were designed to have the lighter steam exit the top while heavier water comes and goes thru the bottom. How can you separate the boiling water from the steam in zero gravity. _URL_1_.\n\nSpace reactors need few moving parts. SNAP generators are what we send to space._URL_0_",
"Nuclear Engineering student here. Our capstone project is revolving around this very idea. \nWe are attempting to design a Gas Cooled Fast Reactor for advanced space applications. Yes it is very possible. Feel free to ask questions. "
]
}
|
[] |
[] |
[
[],
[
"https://en.wikipedia.org/wiki/SNAP-10A",
"https://en.wikipedia.org/wiki/Kosmos_954",
"https://en.wikipedia.org/wiki/US-A"
],
[],
[
"https://en.wikipedia.org/wiki/Systems_for_Nuclear_Auxiliary_Power",
"https://www.google.com/search?q=steam+generator&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjMoJ7M6szKAhXEWz4KHbrmAdEQsAQIMg&biw=1600&bih=786"
],
[]
] |
|
2svxxf
|
how come we don't spend more research or exposure investigating ufos?
|
I've been reading a lot on the subject but it always seems like a taboo subject in the mainstream.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2svxxf/eli5_how_come_we_dont_spend_more_research_or/
|
{
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"text": [
"A true UFO does not mean aliens. You can bet yer ass the US investigates what other country is illegally using our airspace. Otherwise, there's a good chance that it was a government craft being tested, so of course it isn't investigated.",
"Because it would expose the hidden flying object programs of the various countries governments. Either that or the governments know all to well about the aliens visitors and refuse to tell on the grounds that it would cause a mass panic whenever a visitor dropped in.",
"Those programs answers would be classified, as the result of any advances in any particular governments airforce (or beyond) abilities would automatically be classified until the assessing body knew they had counter measures in place. Art of warfare dictates the necessitiy for discretion until the threat is so great admission of limitations of engagement are necessary. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
3sa089
|
reality doesn't exist until we can measure it
|
You see a lot of social media buzz about this sort of stuff and experiments done to prove it, but I'm not sure I really understand. What do these things mean and how does it scale?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3sa089/eli5_reality_doesnt_exist_until_we_can_measure_it/
|
{
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"cwvc808"
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"text": [
"The most common interpretation of Quantum Mechanics - the Copenhagen Interpretation - states, that the wave function of a system only collapses into a defined state when it is being measured. Before that, the wavefunction is a in a superposition of classically mutually exclusive states.\n\nTo understand what this means, let's back up a little:\n\nQuantum Mechanics is a probabilistic theory. That means, it cannot predict how a particle will act, it only predicts the probabilities of acting in a certain way. To learn more about determinism vs. probabilism, click [here](_URL_1_).\n\nWhen QM was first proposed, many people - most notably Einstein - thought it was absurd to think that the universe was not inherently deterministic. Hence Einstein's famous exclamation:\"God does not play dice\".\n\nThus, the opponents of this probabilsim came up with several solutions. One of them was, that Quantum Mechanics was deterministic, but we simply couldn't see the variables governing the outcome. This theory is called hidden local variable theory.\n\n* \"Local\", because those variables obeyed special relativity. That means, faster than light communication is not possible.\n\n* \"Hidden\", because we couldn't see those variables, but they are still there. Even if we can't see them. This concept is also called \"realism\" because things are \"real\" even if we are not looking.\n\nJohn Bell, a famous physicist, devised an experiment to test this local hidden variable theory. To learn more of this experiment, click [here](_URL_0_).\n\nThe result of this experiment was, that the local hidden variable theory was wrong. Thus, either localism, or realism (or both) had to be wrong.\n\nIf localism were wrong, the theory of relativity would be wrong as well. The theory of relativity, however, works exceptionally well, so most people tend to see localism as correct.\n\nThus, realism - the concept that things are the way they are, even if we are not looking - had to be wrong.\n\nThat is what the phrase \"Reality doesn't exist until we measure it\" refers to.\n\nOn a practical note, this means that the position of an electron is not determined before we measure it. Before the measurement, the electron can only be described by a probability cloud that assigns each infinitetsimal volume ∆V in space a probability of finding the electron in this volume.\n"
]
}
|
[] |
[] |
[
[
"https://www.youtube.com/watch?v=ZuvK-od647c",
"https://www.youtube.com/watch?v=dmX1W5umC1c"
]
] |
|
byjjyj
|
why can't we just breed tiny fish babies en masse and dump them in the ocean to solve overfishing?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/byjjyj/eli5_why_cant_we_just_breed_tiny_fish_babies_en/
|
{
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"text": [
"Everything you say is reasonable until you get to the \"Assuming that someone is willing to pay for all this.\"\n\nIt would be expensive for the government or whatever organization did that and with the cost passed along to the consumer, prices of fish would put people off from buying them. \n\n\"Have marine authorities enforce a \"no fishing\" season.\" Lol. This would mean an incredible amount of resources would need to be thrown at the problem. Understand just how big oceans are. Plus... let's say there is a scenario where the government actually spends the money ($$$$$$$) to do this. You don't want to actually start a war over fishing rights. No country has \"dominion over the oceans\" and you would need a world-wide fishing ban which isn't EVER going to happen."
]
}
|
[] |
[] |
[
[]
] |
||
4a2rkf
|
[Physics] Why doesn't a superconducting wire gain infinite current?
|
So thanks to V=Blv, the voltage induced in a wire is equal to the magnetic field the wire is moving through, times the length of the wire, times the velocity of said wire.
But when combined with I=V/R, a superconducting wire (R=0) should have infinite current!
Please explain, thanks in advance!
|
askscience
|
https://www.reddit.com/r/askscience/comments/4a2rkf/physics_why_doesnt_a_superconducting_wire_gain/
|
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"text": [
"Ohm's law V=RI doesn't always hold. It fails in many situations; one of these is superconductors.\n\nThe basic idea of Ohm's law is that electrons scatter randomly with the conductor. (More precisely, exactly what feature of the conductor and what kind of scattering depends on the temperature).\n\nIn a superconductor quantum coherence kills this \"friction\" and therefore the energy loss.",
"Any physical device is limited by how much current it can produce so that is what comes into play if you short circuit it. In circuit theory we model actual voltage sources as ideal voltage sources (which would produce infinite current) in series with a small resistance. That small resistance sets the maximum current the the source can produce.",
"Ohms law states, that the voltage drop U across a resistor with resistance R is dependent on the current with \n R * I = U\nWith a superconductor you have R = 0 and therefore U = 0, there is no voltage drop across a superconductor and therefore no resistive energy loss of a current flowing through it. A superconductor coil that is shorted on the end will hold an induced current alomost forever, which can be used as an energy storage\n_URL_0_\n\nThe current induced into a super conductor is not dependend on ohms low but rather on the other laws mentioned in the other responses, the current will be couteracting the outside magnetic field and is therefore not infinite.",
"The answer actually is pretty simple. Quantum details aside, the answer is NO, because the current generated by the SC would create a magnetic field and all SC have a critical magnetic field in which they \"become\" normal again, regardless of the temperature...\n\nSo each SC have a maximum current (temperature dependent)"
]
}
|
[] |
[] |
[
[],
[],
[
"https://en.wikipedia.org/wiki/Superconducting_magnetic_energy_storage"
],
[]
] |
|
3yv9uq
|
Why did Mongolia achieve independence so easily whereas other independence movements in China (Tibet, East Turkestan, Outer Mongolia) have failed?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3yv9uq/why_did_mongolia_achieve_independence_so_easily/
|
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"Minor correction in your title: Outer Mongolia is Mongolia. *Inner* Mongolia is the province in China.",
"I think the OP is operating under the false premise that \"Mongolia\" was able to fully achieve independence, seeing as how nearly half of it is in another country. Consider a hypothetical reunification of Northern and Southern Koreas, however North Korea is completely annexed by China, therefore leaving only one Korea, that is the South, hence \"unified\". Seems rather ridiculous doesn't it? There is a country called Mongolia today, but it in no way encompasses all Mongol subgroups or even all of the historical territories of Mongolia Proper. ",
"Modern Mongolia was created as a buffer state between the USSR and China/Japan. \n\nIt was originally integrated with China in 1206 as a the conquering Mongols. After the collapse of the Mongol Empire, Kublai Khan consolidated the Eastern holdings and founded the Yuan. Mongolia was firmly within Chinese control until 1920 _URL_2_\n\nIn 1921, as China enters into general chaos (with Japan pushing further into Northern China) and Chinese \"warlords\" splitting the country into a massive Civil War \n_URL_0_\n\nMongolia takes this opportunity to break away and seek help from the USSR (to protect themselves from both China and Japan), the USSR gladly accepts. \n\nMongolia achieves independence (in 1921) and is made into a Soviet Satellite State 3 years after (1924)\n_URL_1_\n\n\n",
"The tempting way to answer this question is to make some comparisons between Mongolia and Xinjiang.\n\nBoth of those territories are similar in that they were never \"Chinese\", they are both steppe territories which no Chinese state had ever turned into provinces in pre-modern times, they were unsuitable for the sort of agriculture practiced in China proper, and they both had very small number of ethnic Chinese by the late 19th century.\n\nSo logically both of those regions -should- have being independent following the fall of the Qing dynasty when the central government ruled by decedents of nomadic conquerors in China was replaced by a nationalist, Republican government ruled by ethnic Han Chinese. The role of those regions as a part of the multi-ethnic Qing empire was gone and what sort of role was to be played in a nation state which excluded them was unknown. Yet only Mongolia declared independence in the aftermath of the 1911 revolution.\n\nFor several reasons Xinjiang did not go independent from China upon the fall of the dynasty or even when the Nationalist central government was weak and had almost no control over the region during the 1920s-1930s. Furthermore, just as in Mongolia, there were alternatives to Chinese rule: The Japanese and the Soviets both had interest in chipping the region away from China. The Soviets went as far as invading in the 1930s.\n\nBut yet Xinjiang was never de jure independent from China, this had to do with several factors as identified by Kenneth Pomeranz:\n\n**1)** Placate/allying with the local elite, there is a strong line of continuity in Chinese policy from the Qing to the Republican to the Maoist era (sometimes the exact same people were in charge across different regimes) in which Chinese governors of the region mostly (but not always!) restricted Chinese migration as to not provoke the locals (along with other policies of course). A hands-off approach by whichever governor was put in charge of the region was expected. As a result the local elite -preferred- to deal with the Chinese government rather than full on independence. And at least enough of them preferred the Chinese government over the Soviets.\n\nBy contrast in Mongolia the Qing government had started to sinonize the region in the early 20th century in an effort to keep control over the region, by doing so they ironically provoked the Mongolian elite into declaring independence and requesting Russian aid.\n\n**2)** The Chinese intellectual elite were able to convince themselves that Xinjiang was really a part of China: this is especially vital because in the 19th century the region was essentially a buffer state for the Qing Empire and there were serious talks about withdrawing from the region for a while. By the 20th century there seem to be a conviction to make an effort to keep the region.\n\nI think the same could be said with regards to Mongolia at least superficially, but the Chinese Communist government chose to give up all claims to the region. The KMT in Taipei however theoretically still claims Mongolia as part of China to this day.\n\n**3)** China was able to convince -everybody else- that Xinjiang is a part of China as oppose to a colonial possession like British India.\n\nObviously, this was not true of Mongolia, but it could be said that it's because China simply lost the territory too soon after the 1911 revolution.\n\nSo I think of the three reasons, they key reason really had to do with how the Qing government dealt with the local elite in the early 20th century and threatening to turn Mongolia into an ethnic Han majority province (as they already did with Manchuria) and pushed them into the anti-Chinese camp. Whereas in Xinjiang this process was mostly resisted until the 1980s. Yes, Soviet support was crucial for Mongolian independence, but yet the same sort of armed support was in place for Xinjiang (and was for a period of time during late 30s-40s when Xinjiang was a de facto Soviet satellite). But the local elite never declared independence except for one small separatist group and therefore allowed for China to play the waiting game in the 1930s-40s until they were strong enough to reclaim the region. At the same time, I can't think of too many pro-Chinese Mongolian elites after 1911. The opinions of said elites was the crucial factor in the contest over the fate are periphery regions where the ability of central governments to project power was relatively weak.",
"Well, Xinjiang and Tibet *did* actually enjoy brief *de facto* independence periods after the Qing dynasty kicked the metaphorical bucket.\n\nThe Tibetan State after the Qing fell was mostly unrecognized, being claimed by the KMT government of China, and recognized as such by most of the world.), but enjoyed *de facto* sovereignty, although there was some British influence drifting up from India, although I don't know the level to which this was. Tibet, although unrecognized, effectively operated as a sovereign state for about 40 years, until after the Chinese Civil War, when, as part of Mao's goal to \"unify the motherland\", Tibet was invaded and annexed, becoming the modern day Xizang Autonomous Region. In 1959, the Tibetans ha a brief uprising, with Indian and American support, mainly among the Chushi Gangdruk, guerrilla fighters who sought to overthrow Chinese rule in Tibet. This was unsuccessful.\n\nXinjiang had *two* periods of independence before ultimately being absorbed into the PRC. The first, existing from late 1933 to early 1934, started out as an Uyghur rebellion around the Kashgar region, and attempted to found a sovereign Islamic Uyghur Republic, until they were attacked by Hui warlords, who were allied with the KMT, bringing Kashgar back into Chinese hands.\n\nThe second East Turkestan Republic was a Soviet satellite state centered around Ghulja or Yining, in Xinjiang's north, modern Ili prefecture. The second republic was born out of a Soviet-backed uprising in Ili, and was effectively a puppet of Moscow. In August 1949, just before the end of the Chinese Civil War, the PLA marched into the ETR, which, at this point, had more or less collapsed, while at the same time pushing the KMT out of Xinjiang. The old leaders of the Republic were killed on Stalin's orders, when their plane was shot down. \n\n(Outer) Mongolia's independence was actually short-lived at first, with ROC forces of the Beiyang government occupying the country from 1919 to 1921, and Mongolia's independence was only revived with the help of Baron Von Ungern's white army, which helped to restore the Bogd Khan, and with it, Mongol independence. Only a few years afterward, in 1924, the MPP overthrew the Khan and made Mongolia a communist state with Bolshevik assistance, making Mongolia effectively a Soviet satellite.\n\nSo, why did Mongolia manage to retain sovereignty while Tibet and East Turkestan ultimately fell to the PRC?\n\nThe two biggest reasons were probably the matters of recognition and influence. Mongolia was a recognized nation by most of the world, whereas Tibet and the two ETRs were not, giving them legitimacy as a state in the eyes of the international community. The reason of influence, which was probably why Mongolia maintained it during the tumultuous years of early Communist Rule, was that the Mongol People's Republic was backed by the Soviet Union, which, until the Sino-Soviet split, was Communist China's most valuable ally. Stalin had actually adamantly pressured Chiang Kai-Shek to recognize Outer Mongolia's independence shortly after WWII, and when the regime changed in China, Mao's government kept the same position on Mongolia that their ally had forced their adversary to adopt. \n\nEDIT: fixed year of fall of Second ETR from 1959 to 49.",
"As a related question, since it's comes up, why did only part of Mongolia become an independent state, and not Inner Mongolia as well?"
]
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[] |
[] |
[
[],
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"http://interwars.weebly.com/uploads/2/3/3/6/2336762/9437931.png?391x361",
"http://www.zum.de/whkmla/histatlas/russia/cccp1924.gif",
"http://www.euratlas.net/history/hisatlas/china/192620TukiunTRZ.jpg"
],
[],
[],
[]
] |
||
3e7p17
|
why do we have both cities and counties? what purpose does this serve?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3e7p17/eli5_why_do_we_have_both_cities_and_counties_what/
|
{
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"Counties are political subdivisions of a state. The are there to provide varying degrees of local governance within the state.\n\nCities are governmental entities where people in a certain area want additional services, and form a government to do that. There are things that cities do that counties don't.\n\nEveryone is in a county*. But not everybody is in a city.\n\n\n\\* This includes county equivalents like parishes and independent cities."
]
}
|
[] |
[] |
[
[]
] |
||
96q4ws
|
why can't necrosis kill tumors?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/96q4ws/eli5_why_cant_necrosis_kill_tumors/
|
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"There are plenty of toxins available. The trick is not finding a toxin, but is getting the toxin to the tumor specifically and keeping it there so it doesn't damage everything else. I see nothing about sphingomyelinase that would make it more amenable to that targeting than any other toxin is.",
"My first thought is: killing cancer cells isn't a problem - killing them while keeping normal cells intact is the real challenge.",
"I suppose in theory you could, but we already have chemicals which could be used to kill tumors. Or the preferred method is to cut them out entirely.\n\nThe problem with cancer isn't that tumors are some sort of immortal super-tissue that can't be killed, it is that they spread and set up shop in tissue we don't want to disturb.",
"A brown recluse might bite you on your arm or leg, which are areas that mostly contain flesh and are free from organs. Tumors can be located anywhere in your body, but if you purposely inject recluse venom into the tumor, you might kill the tumor and also cause collateral damage. For example, targeting a tumor in your kidneys will also cause organ failure, which may impact neighboring organs and kill you as well. ",
"As others have stated, the challenge with most cancer therapies is that they will usually affect normal cells in addition to the cancer cells. Like an oncologist once told me, we can remove cancers no problem, either burn them with radiation, or cut them out with surgery, or poison them with chemotherapeutics. The hard part is keeping the patient alive when all of that is going on. \n\n\"Necrosis\" is an important concept in cancer biology, it is actually a common feature of many solid tumors. Basically, the tumors grow faster than their blood supply can keep up, so the parts that are too far away from blood supply will die, i.e. necrose. Many tumor types have a necrotic center, but as long as the outside area is alive, the tumor will keep growing. ",
"Chemo does something like that, the goal is to find a drug which is more toxic to rapid-dividing cancer cells than regular cells but it is still hard on regular, healthy cells. That's why people on chemo get nauseated and also have cognitive issues (\"chemo brain\") -- the body is being exposed to poisons during chemo.",
"We do something similar for certain cancers, where we inject the chemo drug directly into the tumor. The concentration of the chemo is highest in the tumor, and the amount that gets absorbed into the blood stream and into the rest of the body is often lower than if you gave IV chemo.\n\nBut if you have multiple tumors (metastatic disease) that becomes difficult. It also depends if the tumor is in an easily accessible area to inject.\n\nIf it’s a single tumor, the treatment of choice is surgical removal of the tumor, if possible. Sometimes we do radiation therapy first to shrink the tumor, then surgically remove it.\n\nUsing venom is an interesting idea. It would need to go through clinical trials. You’d probably have to give some antidote at some point after injection. Another concern is that massive tumor necrosis can cause serious adverse events, a condition called [Tumor Lysis Syndrome](_URL_0_)",
"It can, but so can chopping the affected body part off with an axe. The problem with both methods is that they kill normal cells that would be better left intact.",
"There is a way of treating a tumor is such a way which is based on the inhibition of the [angiogenesis](_URL_0_), which practically make it so that the tumor won't receive blood. However the problem with tumors is usually not how you remove it, but if you can remove it before it has spread in your body.",
"Chemo works by destroying bloodvessels for tumors starving them of oxygen, but it also does so for healthy parts of the body. Radiation therapy attempts to localise the damage to the unhealthy cells, limiting the damage on healthy cells. This is difficult, and healthy cells will die alongside the unhealthy ones. There's experiments with using Tcells (a part of the body's own immune system) to target unhealthy cells, and the future I hope will bring highly customised anti bodies that can recognise unhealthy from healthy cells. ",
"Bee venom has shown promising results, using nano robots to disperse the venom inside the tumor. Of course, many folks are allergic to bee venom, AMD it is an allergy you can develop at any time in your life, especially if you are exposed regularly. ",
"We need nano bots. Send 5 trillion into the body, take care of the cancer and them they all come out like a rainbow 2 weeks later. Then they're cleaned and used on the next person."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[
"https://en.m.wikipedia.org/wiki/Tumor_lysis_syndrome"
],
[],
[
"https://en.wikipedia.org/wiki/Angiogenesis"
],
[],
[],
[]
] |
||
c07l4c
|
how much influence do large banks have on government laws, and why?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/c07l4c/eli5_how_much_influence_do_large_banks_have_on/
|
{
"a_id": [
"er2jm34"
],
"score": [
4
],
"text": [
"Anyone with large amounts of money can have influence. You can't specifically say \"Vote for this law and I'll give you a bunch of money\" but you can make large contributions to the politicians campaign funds or let them know that after their political career is done that they have a really good chance of having a high-paying job at your company. So, if you're a politician and Bob's Bait Store and Bank & Trust has given you a shit load of money over the past years, when Bob comes up to and says \"Hey, I think you should vote for this law that lets us charge %900000 interest compounded every hour\", you'll probably vote for it because you don't want to stop the flow of campaign funds."
]
}
|
[] |
[] |
[
[]
] |
||
9nvdh3
|
does the infrastructure difference between downtown and the suburbs change weather patterns in the area?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9nvdh3/eli5_does_the_infrastructure_difference_between/
|
{
"a_id": [
"e7pbdlg"
],
"score": [
3
],
"text": [
"Absolutely. Alot of urban and downtown infrastructure generates alot of heat. NYC literally has underground steam pipes pumping hot steam around. Blacktop roads also contribute to heat patterns, and of course dense urban roads cause more contributing than sparse rural roads. And not to mention the cars on those roads."
]
}
|
[] |
[] |
[
[]
] |
||
65ppg8
|
Why is Cornwall considered a different cultural group than the English? And what historical roots does this division have?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/65ppg8/why_is_cornwall_considered_a_different_cultural/
|
{
"a_id": [
"dgcbefo"
],
"score": [
75
],
"text": [
"Cornwall is viewed as one of the rare Celtic holdouts on the Atlantic fringe, resisting assimilation more or less successfully. In fact, it was late to be recognized by the International Celtic Congress because the Cornish language had sunk to an extinct or nearly extinct status by the before the twentieth century. Still, its remote geography allowed for the preservation of many unusual cultural attributes as well as Cornish vocabulary and syntax, and so the Cornish delegation was able to argue that it should join the ranks of Ireland, Scotland, Wales, the Isle of Man, and Brittany. \n\nFrom an English point of view, Cornwall is typically regarded as a distant and unusual English county. Many Cornish see things differently. Nationalists are quick to point out that Cornwall (much like the Isle Man) had its own governing body, which was not mentioned by the Act of Union, and so the Cornish are quick to argue that there is no legal basis to claim it is merely one of the English counties. It is a distinct duchy and many are pushing for acknowledgement from London of Cornwall's unique linguistic and political heritage. There is, for example, a strong Cornish revival movement, and local signs are frequently posted in both Cornish and English.\n\nRegardless of how some might view Cornwall, all can agree that it is geographically removed from the core of England and its linguistic and its cultural roots provide an additional means to see it as having a separate cultural heritage. "
]
}
|
[] |
[] |
[
[]
] |
||
63ce90
|
why do we have such a hard time quitting smal unnecessary habbits, like biting nails or cracking our knuckels?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/63ce90/eli5_why_do_we_have_such_a_hard_time_quitting/
|
{
"a_id": [
"dft0ix6",
"dft0l4f"
],
"score": [
2,
2
],
"text": [
"their small so you tend not to notice yourself doing it most of the time and it's more of an impulse. ",
"Because we are creatures of habit.\n\nWhat this means is our brain attempts to give as much work to our subconscious as possible so our conscious can focus on the unusual and new. What this means is when we continually repeat a behavior whether it is simple like biting nails or more complicated like driving home, our brain will try to make it standard operating procedure and pass it off to your subconscious. Eventually you will be doing these things without thinking about them which means it is extra hard to stop them because your conscious brain needs to be watching for when your subconscious brain decides to do an unwanted task."
]
}
|
[] |
[] |
[
[],
[]
] |
||
5ycy5f
|
"The claim that life expectancy in ancient times was only 30 is only true if you include infant mortality." How true is this statement?
|
So lately I have been seeing this pop up, and I'm curious about it, because I haven't actually seen any sources about this. Are life expectancy estimates based on records, skeletal remains or neither? And how do infant mortality, war casualties and death in childbirth get computed into this number?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/5ycy5f/the_claim_that_life_expectancy_in_ancient_times/
|
{
"a_id": [
"dep3jvi",
"depb9uq"
],
"score": [
3,
5
],
"text": [
"This would depend upon the records we have. It's a very tricky calculation. I'm only familiar with early modern and modern calculations, which rely on much better records. Generally speaking, infant mortality is going to skew the number in the same way any number gets skewed in a statistical sense. The average is not always a good number to look at when analyzing data. If there is a high infant mortality rate, it's not necessarily an outlier, but it would be good to separate the data and analyze the average life expectancy of people who make it past infancy. That might be a better way of getting at the information you are interested in. These are just some brief thoughts on statistical analysis. In terms of antiquity, you'd want to be a bit more specific in terms of time and region in order to find out what goes into birth rate. There is a line between history and anthropology.",
"There are no comprehensive demographic records from the ancient world. Much information has been lost, but also the kind of information we want was never kept. What we can glean from census data, city and army sizes, literary anecdotes, tombstone inscriptions, and skeletal remains, is not enough to get at a reliable picture of life expectancy at birth or upon reaching adulthood.\n\nHowever, historians of all pre-industrial societies are helped by the fact that fundamentally the same conditions pertain in all of them. Advances in healthcare and hygiene were limited; subsistence diets changed little, and periodic food crises remained a constant factor. As a result, the demographic data we can gather from more recent times, either in premodern Europe or in developing countries for which comprehensive data are available, may be assumed to apply roughly for earlier periods as well. The resulting demographic models can then be adjusted based on what we know about particular events (wars, epidemics, mass migrations, and the like).\n\nIt is in these demographic models that we find the corrupting effect of infant mortality. The average life expectancy can be calculated simply by taking the average age at death of all people for which this information is recorded. However, babies and young children are particularly vulnerable to disease, deprivation or exposure, and in all pre-industrial societies (due to the constancy of the factors I listed above) the number of infants dying is very high. As a result, for these societies, \"average\" life expectancy is a misleading figure. The average life expectancy *at birth* may have been as low as 30, but if you look only at records for people who made it to the age of 20, you find that *their* average life expectancy was closer to 60. In other words, it's not that people could only expect to live for 30 years; it's that *if they survived their most vulnerable years*, they could expect to grow pretty old. A single figure for average life expectancy does not reflect this.\n\nIt is certainly wrong to assume that people in ancient times actually only lived to the age of 30. If this were true, it would have been impossible for the Spartans to have a Council of Elders of which all members were over 60, for example; it would have been impossible for a man like Sophokles to live to the age of 90, or for Isokrates to live to the age of 98. Rather, these men were the lucky ones who did not succumb to disease or starvation in infancy, and could consequently hope to reach old age in much the same way that we do."
]
}
|
[] |
[] |
[
[],
[]
] |
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