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218287
|
How does a Cameleon change color base on its environment?
|
My question isn't much about Cameleon's skin chemical interaction. It's more about visualization and/or sensing environment: I saw a video where they were placing glasses with different frame colors beneath a cameleon and the cameleon was immediately changing colors base on the colors. What was surprising to me, the cameleon wasn't even looking down to see the color/textures. The question is can they sense colors with their skin? Do they maybe have a different sense? Or maybe their eyes have a wide vision?
Thank you in advance.
|
askscience
|
http://www.reddit.com/r/askscience/comments/218287/how_does_a_cameleon_change_color_base_on_its/
|
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"For reference, this seems to be the video in question. Looks to be a viral commercial.\n\n_URL_0_",
"So the video you are talking about is fake. Chameleons don't actually change their skin to blend in with their environment, the pigments in their skin expand or contract based off of how warm or cold they are.\n\nAs silly as it is, [this video has good information.](_URL_0_)",
"Is this the same process as an octopus changing colour and texture to match its own environment? If not how does an octopus blend in so well?",
"Cameleons are engineered calcium reporter proteins that can be transduced into cells in order to measure calcium flux intracellularly. They change color based on conformation alteration when Ca2+ ions are bound.\n\n_URL_0_\n\n\"Chameleons\" are lizards. ;)\n\n_URL_1_",
"Most chameleons do not change their colour according to the colour of the environment, but rather according to temperature and mood. A dark chameleon is likely to be warming up while a lightly coloured one is cooling down. \n\nAn angry/threatened chameleon will show a mix of black/brown colours, like [this one](_URL_0_), to fend off predators (usually accompanied with hissing, mouth opening etc) \n\nColours are also used for mating purposes, a vividly coloured male is more likely to attract the attention of a female than a dimly coloured one."
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[] |
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"https://www.youtube.com/watch?v=Vs1RlkXTT08"
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"https://www.youtube.com/watch?v=UR_byRbXxvs"
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"http://en.wikipedia.org/wiki/Cameleon_(protein)",
"http://en.wikipedia.org/wiki/Chameleon"
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1g56xz
|
When a thyroid disorder is suspected, are the TSH and T4 blood tests sufficient to confidently confirm or disprove the diagnosis?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1g56xz/when_a_thyroid_disorder_is_suspected_are_the_tsh/
|
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"In addition, one could use:\n\n1. [Thyroid ultrasound](_URL_2_): ?cystic/nodular, size of cysts/nodules, no information on function of nodule (?toxic/non-toxic)\n2. [Nuclear thyroid uptake scan](_URL_1_) using technetium pertechnetate: function of nodules (?hot/\"warm\"/cold)\n3. [Fine needle aspiration](_URL_0_): microscopy for detecting cancerous cells, determine type of cancer (papillary, medullary, follicular, anaplastic, etc.)\n4. Anti-thyroid antibodies: Thyroid stimulating immunoglobulins (Grave's disease), Anti-thyroglobulin antibodies (Hashimoto's thyroiditis), anti-thyroid peroxidase antibodies, etc.\n5. Patient's iodine intake, family history of autoimmune conditions/cancers, etc. from history\n6. Clinical exam: palpable nodule, diffuse goiter, audible bruits, etc.\n\nWhile all these tools are available, one would obviously not use every single one for a given patient. A sensitive test for screening (e.g. TSH level) followed by a specific test to confirm (e.g. T3/T4 levels) would be the usual route. I.e. the test one would use would depend on the patient's presentation.\n\nE.g. case: 45-yr old woman comes in complaining of oligomenorrhea, heat-intolerance, and weakness. The Dx in your head would be hyperthyroidism (woman of child-bearing age means autoimmune -- > ?Grave's). So one would go for a TSH level (would be low), and follow it up by T3/T4 levels and TSI titer to confirm Grave's.\n"
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"http://www.scielo.br/img/revistas/clin/v62n4/a07fig02.jpg",
"http://radiopaedia.org/cases/graves-disease-thyroid-scintigraphy-1",
"http://radiopaedia.org/cases/benign-thyroid-lesion-on-ultrasound"
]
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||
36l3ex
|
why are there fake/bad ads on sites like "putlocker" and other various sketchier websites.
|
First time poster here. Where do these crappy ads come from, who is posting them, how, and why? I'm talking about "find local singles in your area" type ads or obviously false clickbait ads that clearly lead to some sort of virus. Do people actually click on them? Is this what is funding websites like "putlocker"?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/36l3ex/eli5_why_are_there_fakebad_ads_on_sites_like/
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"Imagine that out of the people who visit websites with those ads, 50% of them see the ads. Now imagine out of those who see them, 1% click on them by accident and 0.5% click on them on purpose (e.g. they are computer illiterate, don't realize what they're doing, think they're legitimate, etc.). In reality those numbers are actually a bit higher, but even pretending they aren't, we've just said that 0.75% of the people who visit that website click on those ads. If, say, 1/3 of all computers are unsecured (or the user bypasses the security warnings without realizing what they're doing), we have 0.25% of the people who visit those websites actually becoming infected with whatever virus it is.\n\nNow let's say that the websites this ad is on have an average of 2,000 visitors each day and that the ad is on 20 websites: that's 40,000 viewers per day. 40,000 * 0.25% = 100 people per day who get infected by that virus. Again, in reality, a lot of those numbers are MUCH higher (the virus uses multiple fake ads, more websites, more viewers, etc.)\n\nNow how do they make money off of this? Well, a lot of those viruses show ads of their own. Some of them try to get you to pay money for them to remove the ad. Some of them are paid by other virus creators to install their viruses. Some of them sell your cpu time to botnets. Some of them steal your passwords and then sell your accounts/steal your money/etc. Whatever it is, they find some way to monetize these users.\n\nIn the end, it's just a numbers game: while most people may not click on the ads, and a lot of the people who do may not actually install the virus, there are a *lot* of people that see the ad every day. If even a few of those people install the virus every day, the ad-maker is golden. And once that's happened it's not too hard to monetize."
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[
[]
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|
9y5em4
|
how can the voyager and other craft go to such extreme distance? how does it have enough fuel? why can't we send humans like that instead?
|
I'm curious about these pictures that I see all the time. Voyager or some other spacecraft sends pictures of distant planets, being some light years away. Even pictures of Earth looking like a speck of dust. How did it travel so far? How is this possible?
For humans, I understand it would take tons of more specialized equipment but surely we can send them a great distance than the Moon.
Most of what I say might sound very uninformed and downright wrong. So anything and everything related to this will be very much appreciated.
Thank you for your replies!
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9y5em4/eli5_how_can_the_voyager_and_other_craft_go_to/
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"Voyager and other unmanned spacecraft which are designed for long distances have the ability to shutdown. \n\nSo awesome thing of space is there is no friction or well anything.. so when you launch one of those craft, once it separated from it's boosters, it will keep going in that direction at that speed until it hits something (planet, astroid, etc). Due to that, Voyager can. Shutdown it's systems and conserve energy. (Think of turning off a phone, going on a trip, then turning it back on, it will have the same amount of battery as when you left)\n\nIn addition we use solar technology and other ways to recharge the batteries., With humans, it's a different story. Food, air circulation, gravity, all things we have to continually power and keep working. Making sending humans vs robots different.\n\nTldr: Voyager shuts down during journey and only powers on when it HAS to, also it uses super battery saver mode.\n\nHumans have no such capability (yet)",
"The great thing about space travel is that there isn't anything to slow you down. This means that we can leave voyager doing its own thing and it will just keep going until it hits something. Voyager is one a one way ticket away from earth and one day it will stop sending us data, but it will still be out there. As for why we can't do it with people is simple. Humans generally want to come back home or would at least like to know where they are going. ",
"If you're talking about rocket fuel, it doesn't need any. Once it reaches a certain velocity, it will coast more or less forever, it doesn't need to be continuously thrusted. There is little dust outside the solar system to slow it down. The escape velocity is where the Sun's gravity weakens with distance too quickly to ever pull it back. That was achieved by a combination of the original rocket thrust plus some planetary slingshot manoeuvres.\n\nAs other answers, electrical usage for operating the equipment is minimised to prolong it's operational life.",
"Just to offer one correction, Voyager does not use solar power. Had it been dependant on this it would long ago have shut down due to its distance from the Sun. \n\nVoyager uses a unique nuclear power supply where the heat from slowly decaying radioactive material is converted to electricity. \n\nIn the 20+ years the Voyager probes have been in space the power generated has dropped by about a third. ",
"For starters, humans need to eat...the Voyager probes have been out there for 40 years, so if you add up all the food that a 40 year old has ever eaten, storage space becomes an issue.",
"Nobody mentioned this, but the Voyager missions were created to take advantage of an unusual planetary alignment. They gravity whipped around several planets as they went outward, both saving on fuel, and getting great close-ups of them. \n\nNormally a mission like that would only fly by one, maybe two, and never have enough fuel to break solar orbit. ",
"You’re asking why we don’t just send humans on a one-way trip? This isn’t Kerbal Space Program",
"I’ll be honest I initially thought this was about the U.S.S. Voyager from Star Trek until I got to the last line. The answer there being the Bussard collectors allow underway replenishment of the ship. \n\nFor the IRL probe the answer is simple, Newton’s First law: any object in motion will continue to move in a straight line until acted upon by an external force. There is no air or other sources of friction in space. ",
"Well, once a rocket flies into space it can keep flying without losing speed or using any fuel bc there is no gravity or air to cause it to slow down.\n\nThey have been in space for 40+ years so if humans were to use this mode of transportation it would need to be a one-way trip supplied with enough resources to last several generations.",
"At what distance or time will Voyager no longer be able transmit back data?",
"We can in theory send humans on a deep space journey with today's technology but they won't survive long due to inadequate life support technology. To get an idea of how space travel works try playing Kerbal space program. It looks a bit silly but surprisingly good at explaining simple concepts of science used for space travel.",
"In addition, at least in the general case, humans expect to return. That by itself doubles the need for energy for propulsion.",
"I don't know how to eli5 a gravity assit but I'll try.\n\n & #x200B;\n\nfirst thing you need to know is there's something called conservation of energy, it means if you don't exert any force on an object it'll have the same amount of energy. in this case we'll look at kinetic and potential energy, kinetic energy increases when the body's velocity (you can call it speed) increases and potential energy increases when that same body get's away from the body it's pulling it (in your daily life it's earth, in voyager's case it's the sun). So what does it mean? it means, when voyager get's closer to sun it speeds up and when it get's further it get's slower because it's potential energy is also decreasing and increasing at the same time. \n\n & #x200B;\n\nnow, let's throw voyager in an orbit with varying speed-height, like it get's close to sun and get's further. and if you can calculate it really good, to make when you're close to sun you're also passing behind one of the planets you'll be stealing some potential and kinetic energy from that planet (it's really complicated to explain the actual thing happening so just accept it like that). now you just earned more speed only because you passed behind a planet without burning any fuel. Let's do the same thing with other planets on the way. and there are some massive ones on the way like jupiter and saturn, they're so massive (or heavy if it fits you better) the amount of kinetic and potential energy you'll take from them is HUGE, so huge it's enough to leave the solar system. \n\n & #x200B;\n\nbut making all these maneuvers takes too long, getting to mercury, venus, then to saturn and jupiter and finally leaving the solar system, sending a human on this journey would be very boring for that human and it'd take too much food to stay alive. so we just send the probe without a human.",
"It doesn't take fuel to follow an orbit. \nIt takes fuel to reach one. \n\nThink of an orbit as a type of trajectory. A trajectory is a line you can draw which will show the entirety of the movement of a thing from the moment it starts moving to the moment it stops. If the start point and end point meet, you have got yourself a never ending travel, an orbit. \n\nThe ISS doesn't burn fuel to go round and round the earth (ok it does sometimes but that's because the atmosphere is still present and it degrades the spacecrafts orbit slowly) \n\nIf you start burning fuel, you can start calculating the entire trajectory. The more fuel you burn towards a proper direction, the longer the trajectory becomes. If it becomes long enough that you never fall back to earth, you can then stop burning fuel and you will be eternally* be tracing that trajectory. If you spend enough fuel at specific points, you can draw a trajectory that can even reach out of the solar system, and you will be stuck at tracing that trajectory eternally*\n\n* unless you hit something or you enter an area that has some kind of matter, that can slow you down due to friction and will alter your trajectory. ",
"Also just to be clear, neither Voyager is \"some light years\" away. It's about 14 billion miles away, but it'll take another 20,000 years at its current rate to get 1 light year away from us. Space is huge.\n",
"Voyager has nuclear power for electricity. It is incredibly ineffective from an energy standpoint to send humans a long distance, and also physically and mentally devastating. Things they need to solve for the Mars trips.",
"There's been mention of nuclear generators, how space has no friction, turning off and on power to save energy, and humans needing stuff (food, gravity, oxygen, ect.). One thing I haven't seen mentioned is radiation. Cosmic radiation is very bad for humans (and sometimes even for computers, but less so). It's such a problem that even going to Mars posses a significant risk of cancer. Going beyond that with as little shielding as probes have would only increase the risk.",
"It’s not under constant acceleration. The idea was to bring a small amount of fuel with you to aim it in the right direction, and slingshot it around a couple planets. Once you build up enough speed you keep it, since you’re in a vacuum. \n\nThen you sling your way right towards the deep space beyond our solar system (which, conveniently, is in almost any direction). ",
"Think about it, will be the only thing left of the human race. Space is so vast and empty that its calculated not to hit anything for billions of years.",
"The thing about space is that it takes way more fuel to get there than to navigate it. The further out you are from a gravity well (and the closer to the bottom of your orbit), the more distance you can cover with the same amounts of fuel. And theres nothing to slow you down, pretty much, so you can coast on inertia for vast distances.\n\nYou can also get mileage out of a thing called a gravity slingshot - instead of using fuel to turn, you do a flyby of a planet and let its gravity pull you into the trajectory you want without spending fuel or losing momentum. Deep space probe missions are timed for planetary alignments that let them use those extensively.",
"Think of Voyager like an arrow. Once fired it doesn't need fuel to keep moving. We aimed it in a way that made it pass by large planets the craft would \"fall\" towards and using a little fuel can sling shot out from. The Earth appeared the size of 1 pixel while Voyager was 3.7 billion miles /6 billion km and was taken in 1990. Voyager is now 11.7 billion miles/18.8 billion km away moving at 38,000mph/61,000kph.\n\nA light year is 5,879,000,000,000 miles/9.461x10^12 km so Voyager is only 0.2% of a light year away.\n\nThe amazing part is that we are able to pick up the signal it is sending. The transmitter uses less power than the light bulb in your microwave. By the time the signal reaches Earth it is only one-tenth of a billion-trillionth of a watt.\n\n\nHuman's can't leave Earth like that for a few major reasons. \n \n1 safety. There is no way to shield astronauts from radiation or avoid the side effects of weightlessness. \n\n2 weight. Humans and everything we need to stay alive weigh a lot. \n\n3 space is huge. The Moon is a 3 day trip, Mars when closest is months. From there you're talking years of travel. And when you get to these places you have to survive them, and they are as extreme as you can imagine.\n\nE: a digit",
"When we send a probe across the solar system and farther, we use the gravity of closer planets to sling shot the probe. The physics and math are a bit complicated so just think of it as transferring the potential energy gained by entering a gravitational field of a planet into kinetic energy to propel the probe through space. \n\nAnother thing to consider is that there is no air resistance or frictional force to impede movement. \"A body in motion stays in motion unless acted on by an outside force...\" so fuel does not need to be used once the probe is far enough away from any planet; it will more or less retain its speed and direction without using any fuel.\n\nNow, let us look into why we can't send people:\n\n1. Even with the \"gravity slingshot\" method, space travel may take decades when considering anything farther than Mars. That means you need to have enough food, fuel, water, and etc. to sustain a person's life for that long, which means a much bigger vessel, especially if it's more than one person. That complicates the trajectory and speed of the craft. \n\n2. It is very dangerous. If anything goes wrong, those people are toast. And then considering how long the journey would take, the probability of one thing going wrong throughout the entire trip skyrockets. \n\n3. As of right now, most probes are not designed to return. They send images to us until they run out of energy and die. The probe remains floating in space or stranded on what ever planet we sent it to. It goes without saying you can't do that to a person.\n\n\n\n",
"Hi, I think the easiest explanation is that the Voyager does not use (or need) rockets to propel it anymore. In space there is nothing to slow it down once its out of the gravity of the planets, so its coasting on the initial boost it got. It is in no hurry to go anywhere, so there is no need for it to burn fuel. The battery it uses is based on radioactive decay.\n\nIf you put humans on a vessel, you have to start thinking about having enough food, enough air, filtration and reprosessing of air, lots of power consuming equipment. Suddenly you are in a hurry to get to where you are going. \n\nPutting things into space takes a lot of effort, and the more weight the more effort it takes, and its not linear. Every gram counts.\n\n(There's a lot more to it, gravity of other planets being used to sling it and so fort, but thats not ELI5)",
"Funny, I was watching the documentary about this on Netflix just yesterday. \n\nThey launched two of these guys. Oddly enough, Voyager 2 launched before Voyager 1 (the press was annoyed about this). But it was because Voyager 1 traveled faster than Voyager 2 and would catch up, then passed it. \n\nBoth are launched and use other planet's gravity to \"sling shot\" them and pick up speed. \n\nThey got some crazy cool pictures of a few planets and their moons. And after it passed the last planet Carl Sagan asked for them to turn it around and have it take picture of the solar system from the outside looking in. The various scientists thought this was dumb b/c there was essentially no scientific reason to do it. But Sagan though of it as commentary on the Earth. The Earth was a tiny dot, not even one pixel on the picture that was taken. Every human that exists, that had ever existed was on what appeared to be this tiny spec in the solar system and that we should take care of this planet.",
"The caretaker used a powerful energy wave to strand voyager and its crew in the delta quandrant",
"\nTo answer your main question\nVoyager missions were sent in 1970s so they had a lot of time. Along with a special alignment of planets whose gravity is used to boost (Sling shot effect) the speed of the spacecraft without needing much fuel. \n\nIt's much harder to send humans like that because such a craft would be much more heavier (humans need life support) and therefore needs a lot more fuel.\n\n > Voyager or some other spacecraft sends pictures of distant planets, being some light years away. \n\nTo be fair those pictures of planets light-years away are not real. We don't have telescopes that good. We can however detect them indirectly.\n\n",
"\nTraveling through space takes a lot of time. \n\nYou absolutely could send a human out there the same way. A dead human. Because there is not yet any other human condition result expected from 60 years spent in space. ",
"I don't see a huge upvoted post at the top answering all this, so i guess I'll take a crack at answering you.\n\n & #x200B;\n\nWe could totally send humans out into space, but we don't have a destination to send them. It would take more fuel than we could store (and still liftoff from earth carrying) to turn around and change direction to come back. The alternative, to just shoot people out into space to take pictures of Saturn and never come back is unthinkably cruel. So naturally, these Voyager crafts we sent out were on a one-way mission by necessity.\n\n & #x200B;\n\nIt all boils down to Newtons laws of physics. In space, there is no air or earth or water to cause friction and slow down a ship. Therefore, once you get out of Earth's atmosphere, you don't need any more fuel to keep flying. That ship will just keep going in the exact direction it's already going, forever. Or until it hits something. (Newton's Law #1 Object in motion stays in motion unless an outside force acts on it.) This is very unlike the ideas of travel on earth, where your car or plane or boat runs out of fuel and stops. The earth will always fly through space, orbiting the sun because nothing is slowing it down, and this applies to any spacecraft humans build as well.\n\n & #x200B;\n\nThe biggest barriers to sending people out in a ship like that is that space is REALLY. REALLY. BIG. It would take thousands of years to reach another solar system, and sending people on that is a WHOLE different ballgame. You need life support. You need room for families for colonization. You need renewable water, food, energy. You need to re-create an ecosystem for humans to thrive in, in a confined metal tube that flies through an empty void for thousands of years.\n\n & #x200B;\n\nI guess in summary, the voyager crafts have gone such extreme distances because there's no way to ever get them back. They'll just fly through space forever and always get further away. Fuel isn't necessary for travel, just for acceleration or changing direction, which they don't need to do. Sending humans is totally possible and we send astronauts into orbit all the time, but in order to justify sending someone into space, they need a valid destination and enough food, water, and companions to... y'know... not die on the way there.\n\n & #x200B;\n\nSource: My high-school passion for science and physics. Please correct me if I am mistaken in any of this.",
"A bit of an oversimplification on most of this, but it's a few things. First I'll answer your questions about Voyager.\n\nFirst is the fuel. Voyager uses hydrazine, a fuel that can burn for MUCH longer, but produces less thrust per second. We don't use it for human travel because it takes a very long time to pick up any notable speed (when compared to the vastness of space).\n\nThe second is trajectory. Voyager was launched at just the right time so it could be \"slingshot\" by multiple planets. This is called a Gravity Assist. Imagine a spaceship flying towards a planet very very quickly, but it's aimed *just* next to the planet. Once you enter that planet's gravity, you will start to sort of orbit a bit. But, because you're going so fast, you'll never complete a full orbit around it. Instead, you leave the orbit with extra speed and in a different direction. Of course, you still need to use fuel to make sure the spaceship is going at exactly the right speed and will get launched in the right direction. What made Voyager so great is that it did this on Jupiter and Saturn, while Voyager II went around Jupiter, Saturn, Uranus, AND Neptune. It was perfect timing.\n\nAnother thing is... the lack of people. People are heavy, and the things we need are heavy. Voyager was about 1800 pounds at launch, and is now under 1650 pounds, which is really really light for a spacecraft. Add on a 170 pound man, plus his food, water, clothes, spacesuit, exercise equipment, hygiene products, and all the technology that comes with manned spacecraft, and you added at *least* 300 pounds to that vessel. That's just one person as well!\n\nNow, why can't we send humans that far? Well, with our current technology, we can't fit all the necessary things on one ship to go that far. Humans are heavy, as mentioned before, which means we need more fuel to launch. We also don't want them on that ship for 50+ years because they would start to suffer from symptoms of old age, and they would almost assuredly go insane.\n\nMars is a doable target though. It would be very difficult to launch from Earth to Mars, but it is possible. It would take a long time, but again, it's still possible. However, the next promising project would make space travel MUCH easier. Our eyes are set on going to the Moon to set up a Moon base. Literally. This Moon base would be built up so that it could provide for itself (with some help from Earth of course). There is a debate over whether or not we should mine on the Moon, but if we did, we may discover materials we could use to build more spacecrafts *on the Moon*.\n\n If we can launch a spacecraft the size of Apollo 11 from the Moon, we could reach many more distant planets. This is because the Moon as significant lower Gravity, which means getting off the Moon would be incredibly easy compared to Earth. On Earth, we use different fuels and engines to launch vs when we're in space. The fuels and engines used to launch are *very* inefficient, but provide ALOT of thrust. The exact opposite of a nuclear engine. In space we use *more* efficient fuels that still provide meaningful thrust. We do this because we have to overcome Earth's Gravity. So, on the moon, we can use more efficient fuels and engines all the way through, which gives us more distance to travel. The other part is air resistance. The moon has no air like Earth does, so a lot of the aerodynamic parts we put in Earth made spaceships would be unnecessary, which makes the ship lighter, and again, makes it easier to take off.\n\nTL;DR: Voyager was a masterpiece, and we could absolutely travel further if we launched from the Moon, which is our next big project.",
"For some reason no one has clarified that Voyager has not sent back any images of planets light years away.\n\nThose distances are so fast that Voyager is hardly closer to any such planets than the Moon.",
"To clarify, no man-made object has traveled even a single light year away from Earth. That is an astronomical distance that will take anything man-made centuries or thousands of years to travel. \n\nVoyager 1 and 2 are the first man-made objects to leave our solar system and travel into open space. They have been able to travel these distances due to a number of factors. Once it is shot into space, there is nothing to slow it down so in theory it will travel forever in the same direction. The main reason they have traveled so far is the folks at NASA that controlled the probes are insanely smart and were able to \"steer\" it in such a way that it uses the gravitational energy from the planets that it passed by to slingshot it away at a faster rate than it began. "
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[],
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|
5beq0k
|
why does sound need a medium to travel through and exist upon?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5beq0k/eli5_why_does_sound_need_a_medium_to_travel/
|
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"Sound is just vibrations traveling through a medium, like air or water. If there's no medium, there's nothing that can vibrate, and thus no sound.",
"Sound is movement of particles. If there is no particle there is no movement and therefore there is no sound. \n\nWhen we hear things what we are hearing is the movement in the air. That hits the eardrum is converted into an electrochemical signal in the brain and then we hear it. I.e., sound is a way for us to sense movement. ",
"The highest upvoted answer here isn't correct.\n\nBoth sound and light are waves that move through a medium. You can in fact detect both, or else you wouldn't be able to hear or see anything.\n\nTo generalize, to experience any external stimulus, it needs to get to you somehow. There's no such thing as magic, so the stimuli need to travel through something to get to you (e.g. From the speaker to your ear). In sound's case, it travels through air. In light's case, it's the electromagnetic spectrum.\n\nIf there was no medium in between you and the origin, there would be no way for the sound to get to you. Nothing, NOTHING, can just magically hop through space.\n\nThis is actually a pretty neat and basic topic in theoretical physics. many famous scientists (including Einstein) started by asking questions like you did. For example, \"if sound needs a medium, why doesn't light?\" Answer: it does, and so does everything else we know."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
6leh49
|
how are nuts so high in calories, yet so healthy and good for weight loss?
|
I'm on a diet and bought a 2 3/4 oz bag of mixed nuts and it's 470 calories (380 from fat). This kinda goes against everything I've learned about calories and weight loss.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6leh49/eli5_how_are_nuts_so_high_in_calories_yet_so/
|
{
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"text": [
"I do not know what you have learned about calories and weight loss, but what matters with them is total input in a day being less that output for you to lose weight. The specific value of a single food item does not matter so long as you are burning more calories than you are consuming. ",
"In regards to fats, unsaturated fats are very good for you and are essential for things such as the formation of your cell membrane, among other things. Saturated fats are terrible for you.\n\nHaving said that, nuts generally have a plethora of mono and polyunsaturated fats/fatty acids that are key for different metabolic functions in your body. It's good fat, not chubby fat. Those fats are also good for providing a lot of energy in a compact amount of space compared to other sources of food and as has been stated, they also have many minerals and vitamins in them as well.\n\nIf anything with nuts, you should be more concerned about the salt that is usually on them.",
"Calories are not bad. Fats are not bad. Calories is much more about total intake & total output, and yes, nuts *are* higher in calories than many other items of the same size. So it's important to include the high amount of calories in your overall view of your calories for the day. \n\nOne serving of nuts is only like, a small handful. Not the whole bag.\n\nSince it's not calories from sugar they will not cause a sharp rise & fall in blood glucose, and they're high in fiber and slow to digest so they offer long term slow energy. Nuts generally have good fats compared to say, a bag of crisps. This makes nuts very useful for a healthy snack, and for a workout or an in-between meal snack -because it's slow to digest and will give you energy over a few hours.\n\nNuts also contain lots of vitamins & minerals. LOTS of protein, magnesium, iron, lots of other good stuff. \n\nNuts are both calorie-dense **and nutrient-dense**.",
"They're healthy but not \"eat all you can\" healthy. They are nutrient rich, and the fat in them will help curb your appetite making it easier to make it to your next meal time without snacking. The energy you get from eating them will last a good long while with no crash. That being said you must still limit the amount you eat, and supplement your diet with other food groups.",
"Pretty much every effective diet on the planet is a low carb diet, and nuts (particularly almonds) are extremely low carb."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
yztde
|
Could you completely sound proof a room from sounds outside of it by creating a thin vacuum layer around the room?
|
Let's say you live in a glass dome (similar to Sandy's dome in Sponebob Squarepants, but above the water). Instead of one solid piece of glass that makes up your dome, there are two glass domes, one encasing the other, with a 1 inch layer of air in between. If you were able to create a vacuum in this 1 inch layer between the glass domes would sound outside of the dome be able to be heard from inside the dome? I'm thinking no because there is no medium for the sound to travel through in the 1 inch vacuum between the glass domes. Would this idea work or would physics disagree?
|
askscience
|
http://www.reddit.com/r/askscience/comments/yztde/could_you_completely_sound_proof_a_room_from/
|
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"text": [
"In principle yes, but how would you keep the two domes from touching? ",
"it's a good sound insulation, but the part of the closure that is not under vacuum (the foundation of that dome, for instance, or any mechanical connection between the inner and outer shells of the vacuum enclosure) would still transmit vibrations and hence sound. \n\nsource: for my thesis i built a low temp AFM that's essentially insulated by layers of vacuum, yet the mechanical noise will still affect the scanning at frequencies relevant to human audible sound. ",
"If you have a keen interest in soundproofing, I suggest you research military submarines. As detection is acoustic (sonar) the amount of sound (from their machinery) that they allow to escape into the water is of vital importance.",
"In this physically idealized scenario (perfect vacuum, infinitely dense ground) I believe this is correct."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
19kzvn
|
If a nipple is removed, by any means, does it grow back as a nipple or just regular skin?
|
askscience
|
http://www.reddit.com/r/askscience/comments/19kzvn/if_a_nipple_is_removed_by_any_means_does_it_grow/
|
{
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"c8ozdno"
],
"score": [
15
],
"text": [
"The nipple-areolar complex cannot grow back - after [mastectomies in which the NAC is not spared](_URL_1_), surgeons will often create an artificial nipple and then [tattoo in a surrounding areola](_URL_0_) for cosmesis. "
]
}
|
[] |
[] |
[
[
"http://www.diepflap.it/dati/pag/19/img/104.jpg",
"http://www.plasticsurgerycenterofthepalmbeaches.com/wp-content/uploads/2011/06/before_after_2vive.jpg"
]
] |
||
3v6wva
|
why isn't australia cold and snowy like north america and europe?
|
Its closer to the south pole than the equator
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3v6wva/eli5_why_isnt_australia_cold_and_snowy_like_north/
|
{
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3,
2,
9
],
"text": [
"Victoria (south-eastern Australia) is [only about as far south of the equator as Spain or Virginia are north of it](_URL_0_)",
"No, it's not closer to the South Pole to the Equator. Whoever told you that never bothered to look at a map.",
"[Have a look at this map](_URL_0_).\n\nWhat it shows is the antipodes for every bit of land on earth. It shows you quite neatly that Australia is about as far south as the northern parts of Africa, Spain, Mexico, the southern US are north.\n\nIn other words... a polar region it ain't."
]
}
|
[] |
[] |
[
[
"http://www.mapsofindia.com/worldmap/world-map-with-latitude-and-longitude.jpg"
],
[],
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Antipodes_equirectangular.svg/2000px-Antipodes_equirectangular.svg.png"
]
] |
|
kqva4
|
Why does my Hand Sanitizer expire?
|
I just noticed today that my hand sanitizer expires. It isn't for quite some time (July 2013) but I can't seem to understand why it would.
Is it purely "political"? As in, they make up and expiration date so that consumers will be sure to buy more when that day comes around or is it a chemical issue, as in the ingredients stop working as well after 4ish years of use.
Thanks!
|
askscience
|
http://www.reddit.com/r/askscience/comments/kqva4/why_does_my_hand_sanitizer_expire/
|
{
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"text": [
"[According to this link](_URL_0_) it expires because some of the alcohol evaporates. However this doesn't make the hand sanitizer unsafe or ineffective.",
"Many chemicals and reagents don't become useless or dangerous over time. They just become less effective, often because of moisture contamination (for example, hand sanitizer might become diluted) or growth of microbes. Hand Sanitizer can be contaminated with fungal spores, for example.",
"I really hate that the top two responses link to a shitty 'explanation' for why hand sanitizer 'doesn't really' expire.\n\n[doctoreldritch](_URL_0_) is correct in his/her explanation for how hand sanitizer works, with the key line in his/her link being \"Their cidal activity drops sharply when diluted below 50% concentration, and the optimum bactericidal concentration is 60%–90% solutions in water (volume/volume).\"\n\nWe clean surfaces with 70% ethanol in the lab. Anything less than that is useless. Anything more than that is kind of overkill and a waste of resources, as for most uses, 80% doesn't kill any better than 70%.\n\nSo now the question is, if you leave your bottle of hand sanitizer open, how quickly does the alcohol evaporate, and is that lowered amount enough to still be effective? That is part of where the expiration date would come into play.\n\nBut as to the issue how fast the alcohol evaporates, I don't have a clear reference to point you to. But I do know a fabulously easy way to figure it out using skills my basic microbiology students would know.",
"[According to this link](_URL_0_) it expires because some of the alcohol evaporates. However this doesn't make the hand sanitizer unsafe or ineffective.",
"Many chemicals and reagents don't become useless or dangerous over time. They just become less effective, often because of moisture contamination (for example, hand sanitizer might become diluted) or growth of microbes. Hand Sanitizer can be contaminated with fungal spores, for example.",
"I really hate that the top two responses link to a shitty 'explanation' for why hand sanitizer 'doesn't really' expire.\n\n[doctoreldritch](_URL_0_) is correct in his/her explanation for how hand sanitizer works, with the key line in his/her link being \"Their cidal activity drops sharply when diluted below 50% concentration, and the optimum bactericidal concentration is 60%–90% solutions in water (volume/volume).\"\n\nWe clean surfaces with 70% ethanol in the lab. Anything less than that is useless. Anything more than that is kind of overkill and a waste of resources, as for most uses, 80% doesn't kill any better than 70%.\n\nSo now the question is, if you leave your bottle of hand sanitizer open, how quickly does the alcohol evaporate, and is that lowered amount enough to still be effective? That is part of where the expiration date would come into play.\n\nBut as to the issue how fast the alcohol evaporates, I don't have a clear reference to point you to. But I do know a fabulously easy way to figure it out using skills my basic microbiology students would know."
]
}
|
[] |
[] |
[
[
"http://www.leonardchu.com/blog/index.php/2010/hand-sanitizer-doesnt-expire-so-why-do-they-have-expiration-dates/"
],
[],
[
"http://www.reddit.com/r/askscience/comments/kqva4/why_does_my_hand_sanitizer_expire/c2mh0m5"
],
[
"http://www.leonardchu.com/blog/index.php/2010/hand-sanitizer-doesnt-expire-so-why-do-they-have-expiration-dates/"
],
[],
[
"http://www.reddit.com/r/askscience/comments/kqva4/why_does_my_hand_sanitizer_expire/c2mh0m5"
]
] |
|
1bx8ww
|
Monday Mish-Mash | History on Television
|
Previously:
- [Apologies and Questions](_URL_1_)
- [Poetry and History](_URL_5_)
- [Oratory](_URL_0_)
- [Military Strategy](_URL_7_)
- [Memorials, Statues and Monuments](_URL_6_)
- [Games and History](_URL_4_)
- [Sex and Scandal](_URL_2_)
- [Siege Warfare](_URL_3_)
Today:
First, pursuant to some of the suggestions posted last time, we may try to shift the focus of this daily feature a bit in the future. One thing that attracted some interest was the idea of a feature dedicated to historical mysteries -- things we don't know, things we *can't* know, best guesses and why, etc.
**With that in mind**, I announce in advance that next week's Monday feature will be dedicated to the subject of **historical figures who have simply vanished**. Any time period or culture is acceptable as a venue for your post, and the person in question can have vanished under any circumstances you like. Please make sure your prospective comment includes a thumbnail sketch of that person's life, why it's worth talking about them, the incidents surrounding their disappearance, and a best guess as to what actually happened. If there are competing theories, please feel free to delve into them as well.
Again, this discussion will take place on **Monday, April 15th**.
---
For today, however, let's turn things around a bit. We often talk in /r/AskHistorians of those films and novels (and even video games) that are of notable historical merit, but this question has less frequently been asked of television shows.
And so:
- What are some notable attempts to present history on the small screen? These can be documentaries, works of fiction, or something in between.
- Regardless of notability, what are the great successes in this field?
- What of the failures?
- Any guilty pleasures? Why?
- Any upcoming projects that particularly excite or dismay you?
- More abstractly, what sort of problems does this medium pose to the conveyance of history? What about advantages it provides?
Comments on these and any other related topics are heartily welcomed. Go for it.
**N.B.** To anticipate a possible question, **yes**, you can talk about television productions that have come out within the last twenty years, or even that are airing right now.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1bx8ww/monday_mishmash_history_on_television/
|
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"Oh, so Matthew Sutton, who penned a marvelous book on Aimee Semple McPherson, played an active role in the PBS documentary about it. He wrote a piece about his experience in *The Public Historian*. I highly recommend the piece. ",
"Any Pole interested in modern history will tell you that Bogusław Wołoszański was one of the best \"TV historians\" (he still publishes books and makes historical movies but major works are from nineties and early 2000s) and he is one of the most famous Polish \"major propagator of history\". He produced \"Sensacje XX wieku\" (loose translation: \"Events of 20th Century\") and this program is widely recognized as the best Polish historical TV programme. It was one of the \"oldstyle\" documentaries - lots of talk combined with He published also books, mostly on WWII but he had also \"Sensacje XX wieku\" which had very interesting stories about after-war Europe (I remember part about allegded conspiracy on Charles de Gaulle in sixties). His writing style was somewhat good, not academic but mostly journalistic. \n\n\n",
"BBC4 (UK) deserves special mention for a string of history docs - sometimes on fairly weighty subjects (a couple of recent reviews of the fate of Pompeii), some not so momentous - the history of the A303 (a road), the history of the house (room by room) and, tonight, a history of royal illness.",
"Anything featuring Richard Holmes, but *War Walks* in particular was a fantastic series which really helped me to realise the amount of military history I, as a Brit, have on my doorstep.\n\nAlso *Decisive Weapons*, narrated by Sean Bean (of Sharpe and Boromir fame), whilst very basic, was another good series for making history accessible - it inflamed my fascination with the longbow.",
"This has been mentioned before - but frontline's *From Jesus to Christ* is tremendous in terms of doc's. \nMore on the show front - Deadwood's authenticity is, from what I have gathered, spot on. And it is a brilliant show! \nBand of Brothers deserves mention also, as both authentic and accurate. ",
"The 1970s were powerful times in television. Several fictional series tackled then-contemporary now-historical issues, and provide good 'primary doc'-type commentary on the times. \n\n*Mary Tyler Moore*, *WKRP*, *All In The Family*, *Chico and the Man*, *MASH*, and even *Sesame Street* won awards for their use of history and social commentary in service to the growing focus on human well-being, post-WWII and Korea, and within the Cold-War and Vietnam era.\n\nI will gladly provide a deeper discussion of these shows as sources of primary history, basically news stories in satire form, similar to *22 Minutes*, *The Rick Mercer Report* and *The Colbert Report*. \n\nThere is also an argument to be made that it is valid to conduct a media-studies treatment of these programs, in which we have the historical context for the directors, writers, actors and audience.\n\nFor example: Who doesn't love[ Buffy Sainte-Marie on Sesame Street](_URL_0_)?! That segment was filmed and broadcast during the height of the AIM, after the second Wounded Knee incident, the Pineridge Reservation incident, the found body of Anna Mae Aquash, and before The Long Walk. There's so much to unpack in a simple 1-minute segment!",
"Guilty pleasure: The Tudors. Yes, it's a soap opera. But I love the costuming. From all the paintings of the period, I always thought that pantaloons and frilly collars looked goofy. But let me tell you... Jonathan Rhys Myers can rock some pantaloons. I'd like to know more about how accurate the show is about that.",
"[What!?](_URL_0_) No discussions of Mad Men? I love Matthew Weiner's depictions of New York in the 1960s and was really hoping that someone on this subreddit with greater historical knowledge of the period would want to comment on it. Yes, it's a soap opera, but brilliantly done at least from a dramatic perspective."
]
}
|
[] |
[
"http://www.reddit.com/r/AskHistorians/comments/1a36wu/monday_mishmash_oratory/",
"http://www.reddit.com/r/AskHistorians/comments/1azt32/monday_mishmash_apologies_from_me_and_questions/",
"http://www.reddit.com/r/AskHistorians/comments/17fpl8/monday_mishmash_sex_and_scandal/",
"http://www.reddit.com/r/AskHistorians/comments/16k2ml/monday_mishmash_siege_warfare_some_announcements/",
"http://www.reddit.com/r/AskHistorians/comments/17vds3/monday_games_and_history/",
"http://www.reddit.com/r/AskHistorians/comments/1ajczu/monday_mishmash_poetry_and_history/",
"http://www.reddit.com/r/AskHistorians/comments/18rcpp/monday_mishmash_memorials_statues_and_monuments/",
"http://www.reddit.com/r/AskHistorians/comments/19nhiz/monday_mishmash_military_strategy/"
] |
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[],
[],
[],
[],
[],
[
"http://www.youtube.com/watch?v=7-L-Fg7lWgQ"
],
[],
[
"http://www.youtube.com/watch?v=WsJSRP7cZVo"
]
] |
|
23i7od
|
How does our brain turn the sound waves it hears into a something understandable and something we can take information from?
|
it always amazes me and i wonder what the science behind it is?
|
askscience
|
http://www.reddit.com/r/askscience/comments/23i7od/how_does_our_brain_turn_the_sound_waves_it_hears/
|
{
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],
"text": [
"Sound waves enter into your ear and those vibrations come into contact with your eardrum. They travel through the three ossicles and then into the inner ear. One of the three ossicles, the stapes, makes contact with the oval window. This contact disturbs the fluids in the cochlea.\n\nThe cochlea has two important functions: decompose a complex sound into it's component frequencies and transduce the mechanical energy into a neural signal.\n\nLower frequencies will disturb cilia closer to the base of the cochlea, whereas higher frequencies will disturb cilia closer to the apex of the cochlea. At the tips of these cilia, there are potassium channels. When they move, these channels open and cause the cell to depolarize, this causes the release of neurotransmitters and now you have a neural signal instead a mechanical one. \n\nOnce this neural auditory info has been generated it travels up via the auditory nerve to the cochlear nuclei, superior olive, inferior colliculus, medial geniculate body, and finally to the auditory cortex, in that order. I'm sure you can read into this more, but each of these structures help you to localize sound, filter out the sound you want to hear as opposed to noise, and turn those sound waves into something understandable.",
"The inner ear is quite fascinating. To understand this, you have to know what hair cells are.\n\nHair cells are a very special type of cell which gets depolarized (activated) by tilting the stereocilla. Once the stereocilla gets tilted, the \"top opens\" allowing sodium to come in and depolarize the hair cell.\n\nNow, back to sound. Sound travels into your ear and into the cochlea. Depending on the frequency of the sound, it will travel into different depths of the cochlea and depolarize different hair cells. The depolarized hair cells then translate the sound waves into electrical impulses and sends it to the brain. What happens in the brain to decipher the info, i dont know.\n\nThat's as simple as I can explain it. I would highly recommend you to read more into this if you're more interested. It is very interesting."
]
}
|
[] |
[] |
[
[],
[]
] |
|
ch5tzd
|
how do those heart rate monitors on phones that don't have built in sensors work by using only flash and the camera?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ch5tzd/eli5how_do_those_heart_rate_monitors_on_phones/
|
{
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"text": [
"The flash lights up your finger, the camera detects any changes to how brightly lit your finger is. During a beat there’s a little more blood in the vessels of the finger, so it blocks a little more light. The camera can see these small variations in brightness. \n\nWristwatches with pulse meters do the same thing, just with more specialised LEDs and light sensors.",
"you have blood vessels in the finger that pulse ever so slightly, you put the camera over the finger and the app measures any small change in the light as the pulse will slightly elevate the finger from the camera and thus more light will be visible to the sensor."
]
}
|
[] |
[] |
[
[],
[]
] |
||
2f5jtx
|
Copper jewelry
|
I was in a conversation with a friend the other day and the subject of copper jewelry came up. He said that it was not used historically- this smelled wrong to me, but I lacked the knowledge to be sure. Looking online I am seeing some central Americans used it and Egyptians... But this seems incomplete.
Anyone able to site other societies and time periods?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2f5jtx/copper_jewelry/
|
{
"a_id": [
"ck65jg2"
],
"score": [
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],
"text": [
"Copper jewelry exists as far back as the Badarian Period in Egypt (pre-Dynastic circa 4400BC). Copper jewelry is found all over the ANE going as far back as the Chalcolithic period (c 6000BC). Copper jewelry runs from prehistoric Britain all the way through the Anglo-Saxon period (2000BC-1066AD). That pretty much covers everything I've ever looked at.\n\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
2i6lri
|
Can someone tell me about the 17th-19th C History of Lower Silesia, Poland?
|
I'm currently doing some research into the Lower Silesia region of Poland, with a view to marketing it as a site for contemporary tourism, and as such have been looking into its past/history.
I have come across many references to a time when Lower Silesia was an *extremely* popular holiday destination for the European aristocracy, and that this is why the region is so densely populated with stunning palaces. However, I've failed to find any hard facts, stories, or details on this period in Lower Silesian history.
Can anyone out there enlighten me?
When did these people go there? (I'm guessing 17th, 18th & 19th Cs)
Where were they from?
How many of them were there?
How long did they stay? (If they took the trouble to build themselves palaces, they must have returned regularly?)
Did they have any rituals? (eg. big annual parties, marriage arrangements,)
Were any particularly famous people involved?
Any information or sources I should look into would be extremely gratefully received, and thank you very much in advance.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2i6lri/can_someone_tell_me_about_the_17th19th_c_history/
|
{
"a_id": [
"ckzatbu"
],
"score": [
2
],
"text": [
"/u/Premislaus, I hope you don't mind me tagging you, you're just the only flaired user with Polish history in your flair :)"
]
}
|
[] |
[] |
[
[]
] |
|
ezg6ki
|
How were WW2/WW1 ships repaired?
|
How were large sections of carriers' or battle ships' hills repaired? Were there prefabricated parts? and how would each individual naval port have the right prices for each ship?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/ezg6ki/how_were_ww2ww1_ships_repaired/
|
{
"a_id": [
"fgnraqq"
],
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],
"text": [
"Repairs could be made in a number of ways, depending on the extent of the damage, the time pressure on the repair and the facilities available. Generally speaking, prefabricated parts were rare. Instead, repair crews would fabricate new pieces, or patch damaged plates.\n\nThe first, and most immediate, set of repairs that were carried out were carried out by the crew of the damaged ship. 'Damage control', the naval equivalent of first aid, would be carried out immediately upon a ship being damaged. This included shoring up damaged bulkheads, fighting fires, and pumping out flooded compartments. It might also include 'counterflooding', flooding empty compartments on the far side of a ship from damage to keep in on an even keel. Damage control would bring a ship out of immediate danger from the damage. After it, some action could be taken to return a ship to action. Ships carried stores of steel sheeting, wood, and other useful materials, with which to extemporise repairs. As an example of this, on the 4th May 1945, the British carrier *Formidable* was struck by a Japanese kamikaze aircraft carrying a 250kg bomb. The impact blew a two square foot hole in the flight deck, surrounded by a 24' by 20' dent. The hole and dent were filled in by a mixture of cement and wood, and then plated over with steel sheet, which was tack-welded in place. This was a temporary repair, letting *Formidable* continue to operate aircraft until more permanent repairs could be made in Australia.\n\nLonger-lasting repairs could only really be made once a ship had returned to a safe anchorage. At forward bases, repair ships and floating docks allowed repairs to be made, without access to the full resources of a shore dockyard. Repair ships had large workshops for fabricating new parts, as well as the heavy cranes needed to move them into place. Hobbs describes the facilities available to the repair ships *Resource* and *Artifex*, which accompanied the British Pacific Fleet as being 'foundries, coppersmith's, plumbers' and carpenters' workshops, heavy and light machine shops, milling and grinding machines, and electrical repair facilities', while the destroyer tender *Tyne* had two large furnaces, capable of melting and casting up to 500lb of steel. With these facilities, most necessary parts could be made, using only supplies on hand. Damage to the flight deck of *Indefatigable*, caused by a minor kamikaze hit on April 1st 1945, was repaired by men from *Resource* and *Artifex*. They removed the damaged plates, fabricated new ones, and put the new ones into place, in just six days. Floating docks, meanwhile, allowed access to the bottoms of ships. They were typically provided with the same variety of workshops as the repair ships, and worked in similar ways; fabricating parts and plates to replace damaged ones. They were not without danger, though, with HMS *Valiant* being heavily damaged when a floating dock collapsed on the 8th August 1944, damaging three of her propellers. This damage ultimately led to her removal from service.\n\nAt home dockyards, more extensive repairs could be made. This could be quite involved, and effectively take the form of a refit or complete rebuild. After HMS *Belfast* was mined in 1939, her repairs took three years. As the mine explosion had broken her back, large blisters were constructed along either side of the hull. These added extra strength to the hull, and extra buoyancy, but, as they had to be newly built, greatly extended the length of the repair. In other cases, large parts of the ship had to be rebuilt. HMS *Liverpool* had her bow blown off by an Italian torpedo in the Mediterranean. A false bow was constructed in Alexandria, allowing her to steam to Mare Island in the USA for repairs. There, her bow was rebuilt from scratch. Replacements for her British-manufactured equipment that could not be sourced in America were shipped over from the UK, across the Atlantic. Other repairs might involve patching or reworking damaged or dented plates. After Jutland, some damage to the German battlecruiser *Seydlitz* was patched using concrete. In May-June 1945, *Formidable* went into the Garden Island Dockyard, in Sydney, Australia, for repairs to the kamikaze damage described above, as well as damage from a later hit on the 9th. The kamikaze damage had damaged three of the armour plates that made up the deck. They were unbolted from the deck, and examined. Two were easily repaired, being straightened using a hydraulic press. The third was impossible to repair and had to be replaced. However, armour plate of the necessary thickness was not available in Australia. Instead, the repair was extemporised using two thinner sheets of steel. The deck girder these plates bolted to had also been bent. It was cut away and replaced with a newly fabricated one. Several steel plates on the island were also newly replaced."
]
}
|
[] |
[] |
[
[]
] |
|
2uwq0i
|
where does all the internet comes from and why the speed isn't the same everywhere?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2uwq0i/eli5_where_does_all_the_internet_comes_from_and/
|
{
"a_id": [
"coce70q"
],
"score": [
3
],
"text": [
"The Internet is just a bunch of servers and networks that are connected to each other, think of old school telephone operators, you pick up the phone, tell them who you want to talk to, and they connect you to them. This is basically what happens when you are connecting to a website. \n \nThe speeds aren't the same for everyone because of money. The people that give you Internet access charge you based on how fast you want to connect."
]
}
|
[] |
[] |
[
[]
] |
||
1j0gep
|
darren aronofsky's "the fountain"
|
I knew I was watching something very well done, but as for figuring out what actually happened in the movie...
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1j0gep/eli5_darren_aronofskys_the_fountain/
|
{
"a_id": [
"cb9wge3"
],
"score": [
12
],
"text": [
"There are three plot lines going on throughout the movie:\n\n1. In 1500, Queen **Isabella** of Spain wants to find the Fountain of Youth / Tree of Life in the Yucatan, and is threatened by the head of the Spanish Inquisition because of this. She sends her lover, the conquistador **Tomas** in search of it. With the help of a priest who had found a dagger that's actually a map to a lost Mayan temple, Tomas travels to the Yucatan. At first the expedition doesn't got entirely well, and some of Tomas' men mutiny. After they're defeated, Tomas, the Priest, and the few loyal men left go discover the lost temple. All but Tomas are killed by the Mayans guarding it. After fighting his way to the top of the temple, Tomas faces off with the Mayan high priest and is nearly defeated. His life is spared when a luminous, seemingly supernatural being appears in his place and the high priest sacrifices himself, saying something like \"First Father, I did no recognize you.\" Tomas then discovers a massive tree and reflecting pool at the top of the temple. The sap of this tree heals his wounds and he assumes it to be the Tree of Life. Son after he drinks the sap, though, his body is consumed by a surge of new plant growth.\n\n2. In 2000, **Izzi** is writing a book and dying of brain tumor. The story seen in Plot #1 is revealed to be the book she's writing, *The Fountain*. her husband **Tommy** is a neuroscientist, desperately trying to find a cure to save Izzi. Dabbling in Mayan philosophy (at least as presented in the film), Izzi comes to accept the inevitability of her death. She tells Tommy the story of First Father, who sacrificed himself so that the Tree of Life could grow from his body. \"Death is the road to awe,\" she says, repeating a Mayan tour guide she met once. Tommy takes different stance: \"Death is a disease.\" On more than one occasion, Tommy refuses to spend time with Izzi because he'd rather keep trying to save her. He continues his search for a cure, and after some set backs, eventually develops one based on a mysterious tree found in a remote area of Latin America. The cure comes to late. Izzi dies, and at her funeral, a tree is planted on her grave. In accordance with her final wish, Tommy finishes her book.\n\n3. In 2500, **Tom** travels among the stars in a Space Terrarium (Spaceship just doesn't capture the image well). His destination is a dying star, one that Izzi had pointed out to Tommy in Plot #2. It is Xibalba, the Underworld Star of the Mayans. Tom is traveling with **an ancient dying tree**, and haunted by visions of Isabella and Izzi. By eating bark from the tree, he sustains himself through the long voyage to Xibalba. He hopes to arrive before the tree dies so that it can be reborn in the fiery supernova that will result in the star's final moments. Unfortunately, the tree dies shortly before he arrives. He departs the Space Terrarium and is caught in the supernova alone. Dying in such a spectacular fashion, he becomes a transcendent being, and travels back in time to appear as First Father in order to save Tomas' life and far more subtly alters history so that Tommy doesn't squander his final days with Izzi. The assumption here is that Tom is Future!Tommy, having discovered a cure for death and allowing himself to be immortal. The tree is the one planted on Izzi's grave (and based on things said in Plot #2, Izzi has metaphorically become the tree and it fills the Isabella/Izzi role in this section of the movie), and seems to be same sort of tree as the one used to make the cure.\n\n4. My personal interpretation of the entire movie is that all three plots are the finished version of *The Fountain* after Tommy makes his additions after Izzi's death. Most of Plot #1 is what Izzi wrote, Plot #2 is a psuedo-biographical section based on Tommy and Izzi's \"real\" life, Plot #3 is what Tommy wrote himself. The ending, where all three plots crash together, would also have been written by Tommy, helping him achieve some measure of catharsis over his regret from not being with Izzi more during her final days.\n\nEDIT: Since you got me thinking about this movie, I had to take some time to listen to the soundtrack again via Youtube, which caused me to find [this video](_URL_0_) which also explains the movie, and picks up on some things that I skipped over here and offers several possible interpretations."
]
}
|
[] |
[] |
[
[
"http://www.youtube.com/watch?v=UkVS5A5gfGs"
]
] |
|
8hj3tn
|
Why do a large amount of Renaissance paintings have either bad or inaccurate anatomy in regards to humans?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/8hj3tn/why_do_a_large_amount_of_renaissance_paintings/
|
{
"a_id": [
"dyk60yf"
],
"score": [
4
],
"text": [
"Hi there -- you may be interested in [this section of our FAQ](_URL_0_) which covers art in the Renaissance and touches on \"realism\" in painting. "
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/wiki/art#wiki_art_in_the_renaissance"
]
] |
||
3hk1d8
|
why do some of my beard hairs grow in insanely thick while the rest are pretty normal?
|
I have a pretty good beard, but something odd happens. I have a few sporadic hairs that grow super quick and incredibly thick. When I say thick, I mean like 3-4x the thickness of my normal beard hairs. They are also much darker hairs.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3hk1d8/eli5_why_do_some_of_my_beard_hairs_grow_in/
|
{
"a_id": [
"cu83ogj"
],
"score": [
3
],
"text": [
"I, too, would like to know why this happens. Mine seem to be sort of brittle as well, and I generally can't stop myself from fiddling with them until they just sort of break off at the root, only to grow back in in a day or two."
]
}
|
[] |
[] |
[
[]
] |
|
cm88nj
|
why is china lowering the yuan to a decade year low a big deal?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/cm88nj/eli5_why_is_china_lowering_the_yuan_to_a_decade/
|
{
"a_id": [
"ew0kv83",
"ew0kxzg"
],
"score": [
5,
3
],
"text": [
"Does your country trade with China? If yes, the exchange rate is important.\n\nIf the Chinese Yuan (CNY) devalues, it means you can buy Chinese-made stuff cheaper. You are discouraged from buying local-made stuff since the price is higher.\n\nEven if you personally don’t buy Chinese goods, manufacturers will still buy Chinese electronics, steel, agricultural products, plastics, etc and sell the finished food to you. This benefits Chinese companies more than local ones.\n\nObviously, as a consumer you wish for the CNY to devalue even more so you can buy stuff for even cheaper. As a business, it depends if your products are easily substituted with Chinese goods (eg steel vs steel, or computer chips vs computer chips). If you have something unique, you have no risk of losing out and can enjoy lowered costs from cheaper raw materials. If you have very similar products, you will be destroyed by cheap Chinese imports.",
"Probably the main issue is signalling. China's central bank, by not supporting the yuan, allows it to depreciate. This sends a message that China is willing to go further in the trade war against the US. Lowering the value of a currency lowers the cost of your exports but increases the cost of imports. This means local residents might face inflation (price increases). But domestic producer in China who export benefit because their product is now cheaper in the global market - stimulating sales. \n\nThe lowered export cost offsets the impact of the US imposed import tariffs for Chinese exports to the US."
]
}
|
[] |
[] |
[
[],
[]
] |
||
a2nucu
|
Can more than two stars orbit each other, and is there a limit to how many stars there can be in the same multiple star system?
|
askscience
|
https://www.reddit.com/r/askscience/comments/a2nucu/can_more_than_two_stars_orbit_each_other_and_is/
|
{
"a_id": [
"eb0fc57",
"eb0gpj5",
"eb0pr2o"
],
"score": [
14,
7,
2
],
"text": [
"More than two stars can orbit each other: in fact the closest extrasolar star system, Alpha Centauri, consists of two sunlike stars circling one another with a smaller red dwarf companion orbiting them at a great distance.\n\nMore is possible as well: the current record is [seven](_URL_0_), and it's at least theoretically possible for a system to have more stars than that (though obviously, increasingly rare).\n\nImportant caveat: multi-star configurations are only stable under specific circumstances. You can't have three stars rotating at equal distances from each other around a single point, for example.",
"No, unless at least one is far from the other two. There are no closed solutions to the three-body problem, so systems with more than two stars always end up ejecting one (assuming they don't collide).\n\nHowever, if a pair of stars is sufficiently far away from a third, then you can treat the pair as if it were a single star. So a triple system will always consist of a close pair and one outlier. A quadruple system will either be two close pairs that are far from each other or else a close pair, a star further away, and another star *really* far away. These are called [hierarchical systems](_URL_0_)*.* Seven-star systems are known to exist, but the more stars in the system, the harder it is to find a stable solution.\n\nA practical consequence of this is that any habitable planet will have one or two suns in the sky, but not more than that, and it'll only have two if the pair is so close that it orbits both (like Tatooine). Even if the system contains other stars, the rest will be so far away that they'll be points, not disks. (They might be such bright points that you could easily read at night by their light though. Probably really unhealthy to look right at them.)\n\n & #x200B;",
"One of the most interesting ways to visualize space time is with pot holes, or sink holes. Imagine there's a small pot hole in the Earth, smaller in the moon, larger in the sun. These sink holes extend out beyond their mass - warping space time, creating funnel shaped dips in gravity and time. \n\n\nThe interesting thing is you can utilize these sink holes as a sort of highway, sloping into one and flinging out towards another, building speed. \n\n\nThe speed is less important than the concept of these sink holes. Theoretically there's no reason multiple stars can't occupy a sort of venn diagram of overlapping sink holes, rotating around each other, staying in their lane, until eventually the gravity pulls them in and it all collapses. \n\n\nAny arrangement like this will be temporary of course, eventually ending in either collapse or dispersion. But then again - with enough time, our moon might be flung into space too :)"
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Star_system#Septenary"
],
[
"https://en.wikipedia.org/wiki/Star_system#Hierarchical_systems"
],
[]
] |
||
efkm33
|
what exactly is blood pressure
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/efkm33/eli5_what_exactly_is_blood_pressure/
|
{
"a_id": [
"fc0ydtf",
"fc0ynw9",
"fc1kein"
],
"score": [
35,
5,
2
],
"text": [
"Blood runs in tubes around your body. These tubes are called blood vessels, and to drive the blood around the heart pumps all the time throughout our lives (the heart is pretty much a glorified muscle).\n\nWhere does pressure come into it? If a tube (or a balloon, or anything else, really) is chock full of fluid, it might burst, right? That's because the fluid exerts a *pressure* on the container it's being kept in. It pushes outwards on the container.\n\nThe size matters as well. If you have the same amount of fluid in a bigger tube, it would be accomodated better and it wouldn't push as hard on the walls of the tube. Take a narrower tube, and the fluid starts being more constrained and the smaller tube is even more liable to burst.\n\nBlood does the same thing to the blood vessels. The pressure the blood exerts on the wall of the blood vessel is what we call *blood pressure*. The blood vessels change how narrow or wide they are all the time to make sure our blood pressure stays within reason, and when our vessels get trouble doing this it can lead to disease or illness.",
"Blood moves through your body via a series of tubes called blood vessels. Blood pressure is how hard the blood is pushing against the walls of these tubes. If someone's blood pressure goes up, that means that the blood is pushing harder against the tubes.\n\nOne of the main factors affecting blood flow is the pumping of one's heart. When the heart beats, pressure goes up, and between beats, pressure goes down. Consequently, when someone measures blood pressure, they'll find two numbers, with the higher number being blood pressure during a heartbeat and the lower number being blood pressure between heartbeats.",
"Does having more, new blood vessels lower your pressure? For example, weight lifters that have “vascularity”?"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
1u5x5w
|
what is the difference between a web designer, a web developer, and a web programmer?
|
And what is the normal workflow when building a web site between the different specialties, to include database design on the server? And am I leaving anything out?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1u5x5w/eli5_what_is_the_difference_between_a_web/
|
{
"a_id": [
"ceet406",
"ceeux3g",
"ceey1hp"
],
"score": [
13,
2,
4
],
"text": [
"From my limited experience as a network admin\nI'd say...\n\nWeb Designer: This guy has an art background\nand knows CSS and HTML.\n\nWeb Dev: This guy manages a little more than\nprograms. Although he is fluent in just about \neverything, just not great at it.\n\nWeb Programmer: This is your javascript guru.\n\nThe web guys usually stay away from the server.\n",
"As far as workflow, it really depends on where your company's experience is. You outsource the parts you don't have, but here's the basic skeleton:\n\n1. Web Project Manager gets the spec for the job and irons out anything ambiguous. (These people are usually the only ones socially savvy enough to talk to clients, along with the next group.) \n\n2a. UX (User Experience) gets the spec and figures out how to translate function into form. These people used to be called Web Designers, but that term has been misinterpreted as \"I only do Photoshop\", so it's not as often seen these days. \n\n2b. Web Architects get the spec and figure out what technology stack is most appropriate. Few people use the WA title, Senior Web Dev seems to be common these days, but that's what they're doing. They might hand off jobs to the DBA (Database Admin) or to Network Operations (NetOps), but most will do those parts themselves.\n\n3a. Graphic Designers will take the UX wireframes and prototypes and build the assets: images, mostly. These days many/most can also do enough minimal Flash work if it's required. \n\n3b. Web Developers get the spec, now broken down into features (tickets, stories, etc), and do the grunt work coding. They integrate the assets as they get them, but most won't wait to start. Depending on your size, this might be broken down into Front End and Back End teams. \n\n4. As each feature is complete it is passed to Quality Assurance for thorough testing, as well as back to the UX people for review. \n\n5. The PM schedules releases and meetings with the stakeholders and/or clients to show off the work, as well as deployment of the product. ",
"I look at it like this: \n\nDesigner = Interior Decorator \nDeveloper = Carpenter \nProgrammer = Architect \n"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
a46sul
|
what exactly causes our skin to "crawl" when we see something disturbing or unexpected?
|
Probably asked before, but exactly as the title says.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/a46sul/eli5_what_exactly_causes_our_skin_to_crawl_when/
|
{
"a_id": [
"ebc1gxa"
],
"score": [
3
],
"text": [
"That's your hair standing on end. Its caused by a hormone released in response to certain stresses. Its the same thing that makes a cats fur puff out when scared, and done for the same reason. Of course in cats and animals this makes them look bigger, to scare away threats. \n\nBut we don't have nearly as much hair, having lost it over the course of several ancestor species that would eventually result in humans, so we're left with just the crawling sensation or goosebumps. "
]
}
|
[] |
[] |
[
[]
] |
|
7imgg2
|
why did 20th century bombs dropped from aircraft usually made high-pitched, loud whistle-like sounds while falling?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7imgg2/eli5_why_did_20th_century_bombs_dropped_from/
|
{
"a_id": [
"dqzsrez",
"dqzu577"
],
"score": [
37,
29
],
"text": [
"The whistles were purposefully attached to the bombs. Their purpose was to weaken enemy morale and to enhance the intimidation of dive-bombing. Look at the Stuka dive-bomber, a similar case. What other purpose did it's sirens have? As far as warning the target, it's too late to get to safety once you hear the whistle if you're not there already (bombs fall fast). Not all bombs were equipped with whistles, but they still all made noise as they fell due to air displacement (just not the famous whistling sound). This ( _URL_0_ ) page gives one example of bombs that were purposefully fitted with whistles.",
"Because it's terrifying - imagine being on the ground and hearing the whistle. You know that a bomb is coming, but there is no way you can see it, and even if you could working out which direction its moving would be impossible.\n\nThe modern sniper rifles deployed in Iraq got a similar fearsome reputation because of their extreme range - you'd be minding your own business and a wall behind you explodes before you even hear the gunshot. Where did it come from? No idea. What can I use for protection? Nothing, the fucker goes through walls and sandbags."
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Junkers_Ju_87#Ju_87B"
],
[]
] |
||
9yymle
|
why does romaine seem to be recalled so frequently, but other lettuces not so often? is there something about romaine that doesn't occur with green leaf, spinach, etc..?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9yymle/eli5_why_does_romaine_seem_to_be_recalled_so/
|
{
"a_id": [
"ea540l2"
],
"score": [
14
],
"text": [
"I'm not sure if the premise is necessarily true: that Romaine is recalled more often. There is an outbreak E. Coli outbreak going on with Romaine this year, so it may seem that way. However, I certainly remember bagged lettuce being massively recalled a few years ago. Green leaf lettuce recalls have happened as well: (example: _URL_1_).\n\nThe current recalls are so extensive because so much of the product comes from the same geographical area, and produce from one farm may be sold under multiple brands: \n\n\"While investigators haven’t yet determined the exact source of the E. coli contamination, they have linked the contaminated lettuce to the area of Yuma, Arizona. That doesn’t mean the problem is contained, though: the Yuma area produces about 90 percent of all the leafy vegetables — including all the romaine — grown and consumed in the United States between November and March.\n\nThat’s also made it difficult for investigators, retailers, and shoppers to determine which specific brands of lettuce have been affected. Lettuce grown on one Yuma farm might ultimately be packaged by any number of brands, as whole heads, chopped, or tossed with other lettuce in a salad mix. And many product labels don’t include information about the growing region, so it’s tough to be sure. Cases associated with this outbreak have been linked to both lettuce bought in grocery stores and lettuce eaten in restaurants.\" \n (Source: _URL_0_)\n"
]
}
|
[] |
[] |
[
[
"https://www.thecut.com/2018/04/what-to-know-about-the-romaine-lettuce-recall-and-e-coli.html",
"https://www.wallacesfarmer.com/story-salinas-valley-company-recalls-lettuce-8-8960"
]
] |
||
e1ggh9
|
Is arctic methane sequestered carbon?
|
I understand that the carbon in fossil fuels was once atmospheric carbon that became plants and such, then buried. Is the same true for the carbon of methane locked in the permafrost of the arctic regions?
|
askscience
|
https://www.reddit.com/r/askscience/comments/e1ggh9/is_arctic_methane_sequestered_carbon/
|
{
"a_id": [
"f8sa5l9"
],
"score": [
3
],
"text": [
"Yes. The carbon in permafrost comes from organic matter that was originally in the soil before it froze (as is the case for essentially all soils on Earth)."
]
}
|
[] |
[] |
[
[]
] |
|
3mgr3c
|
Would you say America wanted the Cold War more than the Soviets? In other words, did the U.S. "start" it?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3mgr3c/would_you_say_america_wanted_the_cold_war_more/
|
{
"a_id": [
"cvexmj4",
"cvf1pcl"
],
"score": [
2,
2
],
"text": [
"It's simplistic to attempt to attribute the Cold War to one side or the other. Here's the best (and so well written I'm just going to quote it) 'back of the envelope'analysis I've read. From Postwar, by Tony Judt. \n\n\n\"In Europe the Cold War began not after the Second World War but following the end of the First... .The years 1941-45 were just an interlude in an international struggle between Westerns democracies and Soviet totalitarianism, a struggle whose shape was obscured but not fundamentally altered by the threat posed to both sides by the rise of Fascism and Nazism at the heart of the continent.\n\n\n\"It was Germany that brought Russia and the West together in 1941, much as it had succeeded in doing before 1914. But the alliance was foredoomed. From 1918-34 the Soviet strategy in central and western Europe—splitting the Left and encouraging subversion and violent protest—helped shape an image of ‘Bolshevism’ as fundamentally alien and hostile. Four years of troubled and controversial ‘Popular Front’ alliances did something to dispel this impression, despite the contemporary trials and mass murders in the Soviet Union itself. But the Molotov-Ribbentrop Pact of August 1939, and Stalin’s collaboration with Hitler in his dismemberment of their common neighbours the following year, considerably undermined the propaganda gains of the Popular Front years. Only the heroism of the Red Army and Soviet citizens in the years 1941-45, and the unprecedented crimes of the Nazis, helped dispel these earlier memories.\n\n\n\n\"As for the Soviets, they never lost their distrust of the West—a distrust whose roots go back far beyond 1917, of course, but which were well irrigated by Western military intervention during the civil war of 1917-21, by the Soviet Union’s absence from international agencies and affairs for the next fifteen years, by the well-founded suspicion that most Western leaders preferred Fascists to Communists if forced to choose, and by the intuition that Britain and France especially would not be sorry to see the Soviet Union and Nazi Germany engage in mutually destructive conflict to others’ advantage... \" ",
"From the same source: \"... . At least through mid-1946, many US leaders spoke and acted as though they truly believedin the continuation of their wartime partnership with Stalin. Even Lucretius Patrascanu, a senior figure in the Romanian Communist leadership (and later victim of a show trial in his own country), was moved to comment, at the time of the Paris Peace Treaty negotiations in the summer of 1946, that ‘[t]he Americans are crazy. They are giving even more to the Russians than [they] are asking and expecting.'\"\n\nThis changed quickly. American positions hardened after the Berlin Blockade. "
]
}
|
[] |
[] |
[
[],
[]
] |
||
44w1hj
|
what is the difference between a home and a pro version of windows?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/44w1hj/eli5what_is_the_difference_between_a_home_and_a/
|
{
"a_id": [
"cztb9as"
],
"score": [
2
],
"text": [
"You won't probably feel the differences at home.\n\nThe main difference is the Pro editions can be joined to an Active Directory domain. The second is the built-in encryption system (BitLocker).\n\n\n"
]
}
|
[] |
[] |
[
[]
] |
||
5rwyml
|
do governments have plans set in the event of a contact with extra-terrestrial beings?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5rwyml/eli5do_governments_have_plans_set_in_the_event_of/
|
{
"a_id": [
"ddatw6g",
"ddawuhq",
"ddb2pox"
],
"score": [
2,
4,
6
],
"text": [
"Yes. But we can't tell you or we'll have to kill you. \n\nThere's alot of classified what-if plans. Some far-fetched like aliens land, some not like regional or national disaster. ",
"They probably do.\n\nMajor parts of the plans would deal with how to control the reaction of the population to the news. I don't think populations will react the way the media seems to think (everyone panicking / rioting / looting / etc.), but population control plans have to be in place nonetheless.\n\nOtherwise, how to deal with the extra-terrestrials themselves, it depends on what they want. Most of the stuff won't be pleasant to think about or plan for, because the level of technology that allows ET's to reach Earth would put them beyond any type of control that we could exert, and humans in general don't like being powerless like that and are likely to over-react.\n\nThe answer to your question is VERY similar, in my opinion, to the answer to this question: Do governments have plans set in the event of a sudden invasion (or population movement) from a foreign nation?\n\nTo go off on a tangent a bit, one of the things I didn't like in the movie Independence Day was this: replace the alien ships with futuristic planes or helicopters identifiable as from a foreign nation suddenly hovering over the major cites, and none of the waiting and decisions in that movie make sense anymore.",
"Yes, it is called a post-detection policy (PDP)\n\n United Nations Office for Outer Space Affairs (UNOOSA) and the International Academy of Astronautics (IAA) have them. [Here](_URL_0_)\n\nPrivate companies like the IAU, have their [official protocol] (_URL_1_) for an ET signal.(You tell IAU. IAU contacts the world leaders(UN Secretary General). At that point they have a meeting to decide what to do next.)\n\nThe UN controls this, that's why no PDPs have been formally and openly adopted by any governmental entity.\n\nChristopher Mellon (Deputy Assistant Secretary of Defense for Intelligence) said once that the government had \"little if any idea\" of what we'd be up against and \"whatever it is would be so far beyond us it would look and appear magical or spiritual, totally beyond our ability to cope with or resist if hostile. If such an event occurred we'd simply have to muddle through as best we could.\" \n\n\n\n"
]
}
|
[] |
[] |
[
[],
[],
[
"http://i.imgur.com/VNMm5dH.png",
"http://www.seti.org/post-detection.html"
]
] |
||
8ov3f3
|
what is meritorious consideration in contract law?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8ov3f3/eli5_what_is_meritorious_consideration_in/
|
{
"a_id": [
"e06f2qk"
],
"score": [
3
],
"text": [
"In order for a contract to be valid, both parties have to get some sort of benefit from it. I give you $20, you mow my lawn, we are both getting something out of it. The legal term for this is a *consideration*, and a valid consideration is regarded as being meritorious.\n\nLet's say I trick you into signing a contract to selling your car to me for $100, instead of the $10,000 I led you to believe. You could contest the contract on the grounds of my deception, but that might be hard to prove. You could also make the claim that $100 does not qualify as a meritorious consideration, as no reasonable person would sell that kind of a car for that price, and have the contract voided on those grounds."
]
}
|
[] |
[] |
[
[]
] |
||
288dy0
|
What were Teddy Roosevelt's views and political stance on race and equal rights?
|
I was reading in the post about his dislike of Jefferson, and the responder said "One example is when Roosevelt criticizes Benton and Jefferson both for their personal hypocrisies concerning the treatment of people of color. Roosevelt writes: "Like [Jefferson], [Benton] failed to see the curious absurdity of supporting black slavery, and yet claiming universal suffrage for whites as a divine right ..."" Could someone give me a more in-depth explanation of his views on the matter and any political action he took regarding equal rights?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/288dy0/what_were_teddy_roosevelts_views_and_political/
|
{
"a_id": [
"ci8gi6t"
],
"score": [
7
],
"text": [
"Roosevelt's views on race were complicated but on the whole they were progressive for the period (haha). He did support black civil rights. However he spent a good bit of time in North Dakota, and while he was there he became convinced that the local Native Americans were as a group worthless. He went so far as to claim, in an essay about the Dawes Severalty Act, that the American government had more often than not been too soft on Indians. Roosevelt was an enthusiastic imperialist however he didn't explicitly cite white biological supremacy as a justification for imperialism.\n"
]
}
|
[] |
[] |
[
[]
] |
|
erzfu3
|
What happens to the oil that we apply on our skin?
|
My sister has been recommending this massage place that she loves for all eternity now. So the other day I decided to try out. The masseuse applied plenty of oil over my body (so much that it seemed to drip) yet 30 minutes later I notice that my body is just as before. So my question is where did all the oil go? I know my skin absorbed it but where is it stored? And is it likely to get accumulated in my body & make me gain fat?
|
askscience
|
https://www.reddit.com/r/askscience/comments/erzfu3/what_happens_to_the_oil_that_we_apply_on_our_skin/
|
{
"a_id": [
"ff7t6yu"
],
"score": [
15
],
"text": [
"Massage therapists use water-based lubricant, so the majority of the \"oil\" that they applied has simply evaporated. Only a small amount of non-water material remains.\n\nIf you were to try rubbing actual oil on your body, you would find that it does not absorb or evaporate. It just...soaks into everything you touch, leaving it an oily mess."
]
}
|
[] |
[] |
[
[]
] |
|
2rv42o
|
During WW2, how were the Soviets able to so out-produce Germany?
|
Reading *Russia's War* by Richard Overy, there were tables comparing the industrial output of Nazi Germany and the Soviet Union. From 1941-1944 Germany vastly outproduced the USSR in Coal, Steel and Aluminium. Only in Oil did the USSR maintain large superiority.
Yet in terms of military output, the USSR produced vastly greater numbers of planes, tanks and guns than Germany throughout the war. How?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2rv42o/during_ww2_how_were_the_soviets_able_to_so/
|
{
"a_id": [
"cnjyq9u"
],
"score": [
6
],
"text": [
"\nThe USSR had a much more intense wartime mobilization of their workforce. When it mattered.\n\nThe key area is in war-related industry, where from the start of the war until 1943 Germany only increased the workforce in miniscule ( < 1%) proportions (of overall available workers), where the Soviets increased theirs dramatically, from about half the German total (8% to 14.1%) at the beginning of the war to more than double by 1943, when the Germans have 14.2% to the USSR's 31%. At the same time they manage to match the German overall commitment of workers to the armed forces, both sides in 1943 sitting at around 23%. \n\nThe impressive numbers achieved by the Soviets are more than balanced by their incredible losses - in 1941 the Western Front (which took the brunt of Barbarossa) took 191% of its strength in irreplaceable casualties, 1942 was a longer campaigning year, but in all was even more damaging with the Red Army taking 28.9% of its total irreplaceable losses of the entire war (to 27.8% in 1941) - the entire Red Army of 1942 lost 133% of its strength in casualties (including sick and wounded).\n\nThe levels of mobilization on the Soviet side through 1942 were unsustainable, and it begins to cool during/after 1943 as more workers are devoted to domestic/reconstruction tasks. But at this point the war is inevitably won, except for the Germans, who throw in everything and the kitchen sink.\n\nThink of it like the cyclist who starts his sprint too late, and his opponent has created too great a gap to overcome. By most standards the USSR should not have economically survived 1942. If things had gone any worse than they did (i.e. failure of Uranus, German success in Citadel, less aid from allies, no second front) they were fucked.\n\nIf you've got JSTOR access, see: Mobilization for World War II: The USA, UK, USSR, and Germany, 1938-1945 by Mark Harrison in *The Economic History Review* (May 1988); or Harrison's book: *The Economics of World War II: Six Great Powers in International Comparison*; or *Absolute War*, Chris Bellamy (p.473 'To the edge of the abyss').\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
281a15
|
Why does music/sounds make me think of either shapes or a specific color pattern?
|
askscience
|
http://www.reddit.com/r/askscience/comments/281a15/why_does_musicsounds_make_me_think_of_either/
|
{
"a_id": [
"ci6fl6f"
],
"score": [
3
],
"text": [
"You could have 'synesthesia' which is where the stimulation of one sense triggers another. There are various different types of synesthesia as we have many senses, but sound and vision seems to be the most common (of those who have synesthesia, which is pretty rare itself).\n\n _URL_0_"
]
}
|
[] |
[] |
[
[
"https://en.m.wikipedia.org/wiki/Synesthesia"
]
] |
||
1na127
|
if nazi war criminals were given (somewhat) fair trials at nuremberg then why wasn't osama bin laden given one?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1na127/eli5_if_nazi_war_criminals_were_given_somewhat/
|
{
"a_id": [
"ccgpdfs",
"ccgpdgq",
"ccgpgyp"
],
"score": [
2,
6,
3
],
"text": [
"Pretty much impossible to take him alive. The nazis surrendered and went to court. OBL spent a decade on the run, hiding with armed guards.",
"Because he shot at the people trying to capture him, and was killed in the firefight. There's no reason to believe he wouldn't have been given a trial had this not happened.",
"He and those around him were fighting back, and so it was more important to capture him dead than to risk soldiers dying trying to subdue him alive. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
36dra6
|
What is the difference between Roman concrete and modern concrete? Also have we "rediscovered" how Roman concrete was made?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/36dra6/what_is_the_difference_between_roman_concrete_and/
|
{
"a_id": [
"crd59jz",
"crd5kgi",
"crd5us7"
],
"score": [
2,
20,
3
],
"text": [
"That's probably a better question for /r/askscience or engineering. Especially since there are many many many different types of concrete, high strength, corrosion resistant, sulfate resistant, asphalt concrete, etc.",
"First off there's a wide variety of modern concrete. The portland cement part of concrete is the same but what you add to it and the water/cement ratio can vary quite a bit depending on what properties you want out of your concrete.\n\nRoman concrete had volcanic ash added to it. That's similar to modern concrete that has fly ash added to it. Pozzolan (Roman volcanic ash) might wind up being superior to modern fly ash for a couple of very boring reasons involving cement chemistry that I will skip here.\n\nThey've known about that both from chemical analysis of Roman cement and from records that survived from Roman times.",
"hi! there's lots of room for more info here, but you may be interested in previous responses in these posts\n\n* [How did we lose the Ancient Roman invention of \"concrete\"?](_URL_1_)\n\n* [Why was \"roman concrete\" not used for centuries after the fall of the empire?](_URL_2_)\n\n* related thread from yesterday [\"Or they used concrete. Medieval Europe thought the ancient Romans were magic for being able to create seamless floors and pillars, but that was because the secret of concrete was lost to the medieval Europeans.\" How accurate is this quote?](_URL_0_)\n\nThe last thread is still active, but if you have any followup questions on the first two (which are old and locked), just ask them here & include the relevant user's username so they'll be auto-notified"
]
}
|
[] |
[] |
[
[],
[],
[
"https://www.reddit.com/r/AskHistorians/comments/369ucz/or_they_used_concrete_medieval_europe_thought_the/",
"http://www.reddit.com/r/AskHistorians/comments/23893y/how_did_we_lose_the_ancient_roman_invention_of/",
"http://www.reddit.com/r/AskHistorians/comments/16mvvw/why_was_roman_concrete_not_used_for_centuries/"
]
] |
||
65bj6j
|
During the heyday of the Russian Empire, to what degree could Cossacks be considered state-sponsored military colonists (or a 'rank' of the Russian military), and to what degree could they be considered a cohesive ethnic group?
|
I'm asking because I'm doing a bit of research on militarized agricultural colonialism in the Japanese Empire and see frequent comparisons to the Cossacks. But, depending on what source I'm looking at, I get very different answers about whether 'being' a Cossack entails.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/65bj6j/during_the_heyday_of_the_russian_empire_to_what/
|
{
"a_id": [
"dg9x448"
],
"score": [
2
],
"text": [
"While I can't answer, I'm really interested in your topic, militarized agricultural japanese colonialism. Do you have any good reading on that?"
]
}
|
[] |
[] |
[
[]
] |
|
3lyjij
|
how do asians differentiate amongst people based on their countries?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3lyjij/eli5_how_do_asians_differentiate_amongst_people/
|
{
"a_id": [
"cvadsb7",
"cvadx5e"
],
"score": [
6,
2
],
"text": [
"The same way everyone else does. You have difficulty telling Asian nationalities apart because it's not something you do on a regular basis. There are visible ways to tell, and people who are exposed to a wider diversity of Asians know. But then they might have difficulty picking up the differences between say a Englishman and a Frenchman.",
"As someone who grew up in Hawai'i, I can easily tell Asian ethnicity in a majority of cases. The more time you spend with all the ethnicities, the easier it is to tell them apart. \n \nHave you ever known any twins? Well, when you first met them, you probably got them confused for a good while, until you were able to pick out the subtle differences."
]
}
|
[] |
[] |
[
[],
[]
] |
||
4bx31k
|
why is it that sometimes japanese spellings of (video game, tv show, movie, etc) titles are just the sound of the english title written out, even though it comes from japan?
|
According to Wikipedia, the pronunciation of the JAPANESE title of [Dragon Ball](_URL_1_) and [Dragon Ball Z](_URL_0_) are Doragon Bōru and Doragon Bōru Zetto respectively. That doesn't seem to make sense to me, but it's not the first time I've come across situations like this.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4bx31k/eli5_why_is_it_that_sometimes_japanese_spellings/
|
{
"a_id": [
"d1d56mm",
"d1d58w7",
"d1d6r6j"
],
"score": [
6,
4,
19
],
"text": [
"Because they thought it sounded cooler that way. Also \"Zetto\" is probably coming from the Greek \"Zeta\" rather than English.\n\nFor example, rather than just translating \"Gojira\" to \"Gorilla Whale\", the American version was called Godzilla, altering the Japanese name to be more pronounceable for Americans. ",
"The titles are supposed to be English, or at least, very English-like. Doragon Booru is how they write Dragon Ball in Japanese since they're forced to work with a more limited sound set. As for why they do that it could be almost anything depending on the genre and author, but most likely they just thought English sounds cool or think that their audience thinks English sounds cool and rolled with it.",
"They are using English words, the same way English speaking media is using foreign words some times.\n\nThe difference is that the native Japanese way of writing (and with it pronouncing things) is rather different from most European languages.\n\nThey primarily use a syllabary that has very limited number of syllables.\n\nWhen a Japanese person writes the english words Dragon Ball, they would either just write \"Dragon Ball\" using the same Latin characters you use in english or write ドラゴンボール using one of their native scripts. Transliterating that back into Latin characters results in: \"Doragon Bōru\".\n\nWhy \"D**o**ragon\" instead of \"Dragon\"?\n\nBecause the Japanese characters represent syllables rather than vowels and consonants like the Latin characters we use (\"N\" is an exception.). They have charcters for Da, Di, Do, De and Du but not for \"D\" by itself. So this is the closest they can get to representing the English word in that script.\n\nOther things are for example the lack of distinct characters for L and R. They have just one type type of character that covers both.\n\nSo if you see an English word written in Japanese characters you will often find extra vowels everywhere and Rs where you expect Ls and often since the transliteration to Latin characters is not always based on how \"Americans\" would pronounce letters a but a mix of various European pronunciations it doesn't always fir what you would expect.\n\nYou get similar artifacts by transliterating back and forth between other languages using different scripts.\n"
]
}
|
[] |
[
"https://en.wikipedia.org/wiki/Dragon_Ball_Z",
"https://en.wikipedia.org/wiki/Dragon_Ball"
] |
[
[],
[],
[]
] |
|
3f927q
|
what happens to prisoners serving a 100+ year sentence when they start to get senile and old? do you die in prison the same way you normally would of old age?
|
i read an article about a man who served a 144 year sentence, do they just let you die in prison like you would normally of old age?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3f927q/eli5_what_happens_to_prisoners_serving_a_100_year/
|
{
"a_id": [
"ctmg0lg",
"ctmg2he"
],
"score": [
4,
2
],
"text": [
"Pretty much, yeah. If you have medical conditions that can't be properly attended to in prison you might be moved to a secure hospital, but they don't let you out. You will die in prison or some prison-like facility.",
"This article sums it up. Sad business, very sad.\n\n_URL_0_\n"
]
}
|
[] |
[] |
[
[],
[
"http://www.washingtonpost.com/sf/national/2015/05/02/the-painful-price-of-aging-in-prison/"
]
] |
|
1lzn5j
|
After reading about Julius Caesar's Legion's dedication towards him, how did they react when they heard the news of his assassination?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1lzn5j/after_reading_about_julius_caesars_legions/
|
{
"a_id": [
"cc4drzl"
],
"score": [
18
],
"text": [
"Well, by the time of Caesar's Assassination, the Legion had been disbanded and all the veterans had been given parcels of land to live out their days on.\n\nWhen Caesar was assassinated, however, the men must have been outraged simply out of the fact that they reformed their Legion and fought for the Triumvirate right up until the Battle of Phillipi under the supposed name of **Veneria** or 'devoted to Venus'. After the Battle of Phillipi, Legio X Equestris sided with Marc Antony in his Civil War with the other Triumvirs. They lost.\n\nOnce again, they went with the next Caesar in line and went under the command of Augustus. This was short-lived, however, and they rebelled. When Augustus quelled the rebellion, he stripped the Legion of it's *Equestris* title and they took the title of *Gemina* once they had gained new recruits to bolster their numbers.\n\nPast that, we have records going all the way into the 4th Century A.D."
]
}
|
[] |
[] |
[
[]
] |
||
1gmrqu
|
Are diabetes and cancer fairly new illnesses or are they old yet not talked so much about like acne?
|
Does anyone know how far back they have existed and/or the ways they were treated?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1gmrqu/are_diabetes_and_cancer_fairly_new_illnesses_or/
|
{
"a_id": [
"calqxiu",
"caltq5p"
],
"score": [
6,
3
],
"text": [
"On cancer, I can strongly recommend [Siddhartha Mukherjee's The Emperor of All Maladies](_URL_0_), which (among many other things) is a history of cancer and the ways we have treated it. (That is my source for the purposes of this comment, in any case - actual historians of science and medicine may be able to do better!)\n\nOne of the earliest cases Mukherjee talks about is recounted in Egyptian hieroglyphics, the tale of a woman with a breast tumor around 2000 BCE (very roughly). In that particular case, the physician recommended no treatment, but contemporary records suggest that surgery (to remove such tumors) was known of, though you can imagine what the prognosis for patients was like before the (very modern) age of antiseptic techniques.\n\nSo cancer's been around for a very very long time; part of the increase in frequency we see for such illnesses is a consequence of the fact that we are living so much longer, due to better nutrition and control of other infectious diseases. Mukherjee writes quite elegantly about the underlying nature of all cancers, their untamable desire to grow and expand and colonize, as a twisted reflection of the very processes that take us from fetus to infant to child to adult.\n\nIf I were to go on, I'd just continue summarizing his book, and it's eminently worth reading for yourself if you're interested enough in the topic. \n\nEnjoy!",
"Diabetes has been recognized for as long as physicians have been recording diseases: Ancient Egyptians, Indians, Greeks, and Romans all had names for it. It was (and is still today) characterized by sweet urine, from which it gets the name Diabetes Mellitus, which comes from the Ancient Greek verb \"to pass through,\" because they recognized it as a wasting disease where the sufferer rapidly lost weight and urinated out all the nutrients they ate. It was much rarer in the past than it is in modern societies. I've never seen a single recorded case in any of the 16th and 17th century physicians' notes I've looked at."
]
}
|
[] |
[] |
[
[
"http://www.amazon.com/The-Emperor-All-Maladies-Biography/dp/1439170916"
],
[]
] |
|
8or3q9
|
When a water filter (e.g. Brita filter) is past its expiration date, is it just not filtering very well anymore, or is it actively making the water worse?
|
askscience
|
https://www.reddit.com/r/askscience/comments/8or3q9/when_a_water_filter_eg_brita_filter_is_past_its/
|
{
"a_id": [
"e05r27b",
"e0600sx",
"e061yov",
"e06qxtp",
"e07c41i"
],
"score": [
21,
4986,
290,
2,
2
],
"text": [
"If it's unused and sealed properly it will be fine.\n\nIf it's exposed to oxygen both activated charcoal and DI resin will exchange with oxygen and reduce the amount it will filter, thus you won't know how long until of water until it's not working well. Activated charcoal for aquarium filtering is stored a long time, it can absorb a ton. DI resin is usually vacuum sealed and can't be exposed to air for a very long period.\n\nActivated charcoal will leach back into water if it's used way too long though. But it's not dangerous, it will just taste unfiltered.",
"Assuming you have the same water source and it's consistent (tap water, for example), then the adsorption capacity of the filter will eventually get used up. Most filters like a Brita have adsorbents an ion exchange resin (white particles) for capturing metals (lead and copper) and activated carbon (charcoal) for capturing organic compounds and some metals as well. Once the adsorbents have reached their capacity, then the metals and organics that enter the filter will leave the filter unchanged.\n\nThere are some compounds which actually react with the adsorbents. Residual disinfectants (chlorine, chloramine) are [destroyed by activated carbon](_URL_0_), so they will not pass through the filter. Residual disinfectants are added to the water so that organisms do not grow in the time between the water leaving the treatment plant and it coming out of your tap (through the distribution system). An old Brita filter will still destroy residual disinfectants. That can improve the taste/odor of your water if you don't like chlorine.\n\nThe last thing to consider is that if there are no residual disinfectants, then bacteria can grow within your Brita filter. It's unlikely that it would harbor pathogenic bacteria, but bacteria can easily grow on activated carbon if there's no chlorine present. If you leave it long enough, bacteria will grow. For that reason, I'd eventually get rid of an old filter instead of keeping it in place indefinitely.",
"I work in Dialysis, and part of my job is taking city water and turning in to 99% pure H2O.\n\nThis entirely depends on what the filter is made of, and what its actual function is.\n\nIs it designed to remove chlorine? If so it's probably charcoal, and when it reaches its expiration it's generally exhausted and simply won't work anymore.\n\nIs it designed to remove magnesium and calcium, like a softener? Then it'll again, just stop working.\n\nIs it designed to remove larger particulates, often referred to \"Sticks and stones\". Then again, it'll generally just stop working. However in this case, it'll also severely reduce water flow/pressure.\n\nThe only case, that I know of, that will actually decrease the quality of water once it reaches its exhausted state, is a DI, or a Deionizer. These are designed to remove certain molecules from water, such as Flouride. Once they reach exhausted they will actually start bonding with the free hydrogen and oxygen and releasing what they originally picked up, essentially making your water worse than it would be without it, until it finds a natural balance.\n\nAs a general rule though, it really doesn't matter. What's considered safe drinking water has a massive area of tolerance, and unless your filter starts growing bacteria from stagnation and age, you never really need to worry about changing for health reasons. It's largely psychological, some times for taste.",
"If a filter had an NSF our WQA seal on the box like Brita or PUR, it is tested and certified to 200% of the life on the box (if there is no indicator light) and 120% of life is there is a life indicator on the device. So if a filter claims the life is 40 gallons for a pitcher filter, it will remove all contaminants listed on the box to at least 80 gallons. Some contaminants can be removed for a longer life, but that number on the box is based on the contaminant that fails first.",
"'Point of use' filters typically contain carbon impregnated with silver, and possibly some ion exchange resin. The carbon will remove the chlorine residual and some organics. The silver is there to provide bacteria control. The ion exchange resin removes charged ions such as dissolved metals. The entire filter removes particulates in the water. The replacement frequency is based on expected removal capacity of the filter and to get you to replace it before the bacterial control loses effectiveness. So if you leave it on past the due date- at some point you can get biogrowth in there. The IX resin will eventually load up and quit removing ions, and even release ions it previously took up. Ultimately, the carbon will lose effectiveness, and enough solids will accumulate to restrict flow. If you're in the US, unless directed otherwise (see Flint, Mich), you really don't need to do extra treatment as a health issue. If you are concerned about your water quality enough to pay the money to use a filter, than it's kind of defeating the purpose by ignoring the recommended change out frequency "
]
}
|
[] |
[] |
[
[],
[
"http://www.wcponline.com/2009/06/13/chlorine-chloramine-removal-activated-carbon/"
],
[],
[],
[]
] |
||
2a20t4
|
Is it true that Manuel I Komnenos aided the Turks/worked against the crusaders, during the Second Crusade?
|
Here's the quote from the [wiki article:](_URL_0_)
> The main Western Christian source, Odo of Deuil, and Syriac Christian sources claim that the Byzantine emperor Manuel I Comnenus secretly hindered the crusaders' progress, particularly in Anatolia where he is alleged to have deliberately ordered Turks to attack them.
Is there any truth to this?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2a20t4/is_it_true_that_manuel_i_komnenos_aided_the/
|
{
"a_id": [
"ciqq2sc"
],
"score": [
15
],
"text": [
"Not really. It certainly seems that Manuel I was not particularly inclined to help the Crusaders and didn't go out of his way to make things easier for them but actually going so far as to ally himself with the Turks would be too far. It's worth remembering that the Crusaders didn't exactly make themselves out to be great friends of the Byzantines in the First Crusade, they were supposed to hand Antioch over to Alexius I but didn't. We could argue whether or not they acted fairly but it's pretty clear the Byzantines felt that they were in the right on that issue. The First Crusade had done little to benefit Byzantium and wasn't without its problems (Crusaders raided parts of Byzantine territory on their march over) so the premise of a Second Crusade wasn't exactly what Manuel I wanted marching through his territory. Manuel's rather cold reception of the Crusaders, especially in contrast to Alexius' reasonably warm reception ~50 years earlier, didn't exactly endear the two parties. Add to that the fact that Manuel offered minimal assistance to the campaign and you can see why the Western Europeans didn't really like him. \n\nAnother major factor to consider for the Second Crusade is the fact that it failed. The First Crusade was such a resounding success that it was quite the embarrassment when the second failed. For one thing the Crusade was meant to be a mission endorsed by God. For another, the First Crusade featured no royals whatsoever on it while the Second had two (Louis VII and Conrad III). You would expect the presence of two of the most powerful kings in Europe to guarantee a success. \n\nThis left chroniclers of the Crusade in a very awkward position, they had to record a failure which is never ideal. It's interesting to note that the Second Crusade has nowhere near the same number of sources describing what happened as the First or the Third did. Odo of Deuil, the source in question, was in a particularly awkward position. He was sent on Crusade to write an account of how Louis VII acted heroically and defeated the Muslims in defense of his Christian brothers. That's not really what happened so Odo had to find someone to blame for his king's divine mission failing. He couldn't exactly blame Louis and it would be somewhat poor form to try and dump it on Conrad III. Instead he chose the Byzantines as the source of the Crusades failure and blamed much of the problems with the campaign on the treachery of the Greeks. There may have been some already existing animosity towards the Byzantines (mentioned a bit above) that helped push him in that direction. \n\nThomas Asbridge's *The Crusades* is a great general source on all of this. Jonathan Riley-Smith's *The Crusades a Short History* is also good but as you can tell from the title not quite as detailed. "
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/Second_Crusade"
] |
[
[]
] |
|
bbzdpk
|
how did congress set their salaries?
|
Who was in charge of setting everyone in Congress's salaries, benefits, what Insurance provider do they go through? Do they all use the same Insurance provider?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/bbzdpk/eli5_how_did_congress_set_their_salaries/
|
{
"a_id": [
"ekmk6uf"
],
"score": [
7
],
"text": [
"Congress is in charge of the government's money, so they set their own salaries by passing the appropriate bill. The president still has veto power, of course, and any salary changes won't take place until after the next Congressional election. In terms of benefits and such, they're just like any other Federal Employee and their benefits are determined by the Office of Personnel Management."
]
}
|
[] |
[] |
[
[]
] |
|
2r1hty
|
Is there an historical reason Turkey is considered part of Europe/Asia but Egypt is not considered Africa/Asia?
|
This is something that I've come back to a few times now recently, and I'm not sure who to ask.
Why is Turkey considered by many to be part of two continents when the area that is in Europe is so small, yet a larger portion of Egypt exits in Asia? I don't recall ever seeing anything that lists Egypt as part of Asia.
edit: [Here](_URL_0_) is a relevant wikipedia article that lists countries by continent according to the UN Statistics Division. Turkey is listed as transcontinental but Egypt isn't.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2r1hty/is_there_an_historical_reason_turkey_is/
|
{
"a_id": [
"cnbkir3"
],
"score": [
19
],
"text": [
"One thing worth considering is that, since relative land area isn't a number most people have to hand, and it's not a very intuitive way of thinking about geography, relative land area just isn't an important factor in deciding which continent we think a country is part of.\n\nTurkey has at least two major cities in Europe, and its European region consists of four provinces. The center of Turkey's largest city is in Europe. Historically, the Ottoman Empire had major territorial possessions in Europe. It is difficult to really talk about Turkey in geographic or historical terms without giving credence to the fact that it is considered part of both Europe and Asia, because the European part is so prominent and not just a backwater afterthought. \n\nEgypt has... Sinai?\n\nIt's also worth noting that the border between Europe and Asia is probably more culturally important, and definitely more important in Western history and literature, than the border between Asia and Africa. Egypt's status as intercontinental nation isn't really an important aspect of its perception on the world stage or its cultural identity, as is the case of Turkey.\n\nAlso keep in mind that our concept of continents is shaky, at best, and really a cultural artifact rather than a scientific black and white reality. I mean, it's also kind of nuts that we consider Greenland part of North America, but Iceland is part of Europe. And what is even up with Oceania?"
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/List_of_sovereign_states_and_dependent_territories_by_continent"
] |
[
[]
] |
|
2ka2nz
|
Where do the particles to be fired in the Large Hadron Collider come from?
|
The LHD has particles collide at great speeds, sure. But where are these particles acquired? Is it some platinum bar that has flakes shaved off, then processed further to get even smaller stuff to fire? Is a quark captured when it radiates off of something? How do you 'load up' the LHD, and where does the stuff to collide come from?
To maybe phrase it in a different way: "I am a particle flying through one of the LHD's magnetic beams. Where have I been hanging out a day before this trip?"
|
askscience
|
http://www.reddit.com/r/askscience/comments/2ka2nz/where_do_the_particles_to_be_fired_in_the_large/
|
{
"a_id": [
"cljehqj"
],
"score": [
75
],
"text": [
"The protons come from a bottle of hydrogen at LINAC 2. The gas is ionised in a device called a duoplasmatron (effectively a gas-filled discharge tube with a hole in the anode).\n\nFor the lead ions, an isotopically pure sample of ^(208)Pb is heated up until it's vaporised, then ionised into a plasma and accelerated in LINAC 3.\n\nFurther reading:\n\n _URL_1_\n\n_URL_0_\n\n_URL_2_\n"
]
}
|
[] |
[] |
[
[
"http://home.web.cern.ch/about/updates/2013/02/heavy-metal-refilling-lead-source-lhc",
"http://home.web.cern.ch/about/accelerators",
"http://tesla.physics.wmich.edu/Accelerator_Handbook/Duoplasmatron/Introduction/"
]
] |
|
nw2kt
|
Does the human inclination to eat things with a certain taste reflect deficiencies of certain nutrients in the body?
|
I know that a salt appetite can develop from a sodium deficient diet, does this mean that a person who lacks sufficient iron in their diet will be more inclined to eat an iron-rich food (steak, fish).
thanks
|
askscience
|
http://www.reddit.com/r/askscience/comments/nw2kt/does_the_human_inclination_to_eat_things_with_a/
|
{
"a_id": [
"c3cdzdh",
"c3cevz9",
"c3cdzdh",
"c3cevz9"
],
"score": [
4,
10,
4,
10
],
"text": [
"Pica, intense cravings for non-food objects such as dirt, often results from iron deficiencies. It stands to reason that other food cravings could have similar roots...see [here](_URL_0_).",
"this was discussed a few weeks back with some good answers here:\n\n_URL_0_",
"Pica, intense cravings for non-food objects such as dirt, often results from iron deficiencies. It stands to reason that other food cravings could have similar roots...see [here](_URL_0_).",
"this was discussed a few weeks back with some good answers here:\n\n_URL_0_"
]
}
|
[] |
[] |
[
[
"http://www.sciencedirect.com/science/article/pii/0195666390900232"
],
[
"http://www.reddit.com/r/askscience/comments/n1aaa/do_cravings_for_specific_kinds_of_food_mean/"
],
[
"http://www.sciencedirect.com/science/article/pii/0195666390900232"
],
[
"http://www.reddit.com/r/askscience/comments/n1aaa/do_cravings_for_specific_kinds_of_food_mean/"
]
] |
|
277anz
|
what happened to aol, man?
|
They used to be such a huge company, they dominated the internet scene, and then like that...gone?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/277anz/eli5_what_happened_to_aol_man/
|
{
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"chy1o9e",
"chy1oue",
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"chy2x40"
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"score": [
8,
6,
3,
2
],
"text": [
"They're still around, mostly as a branding/media company. They own the Huffington Post, for example. (They own a lot of other properties and have an extensive online advertising arm, but HuffPo is the most notable.)\n\nAs far as their online services went...they had specialized in the \"walled garden\" approach, which worked in the early days of the internet but soon became obsolete. Then they merged with Time Warner and just kind of got lost, later to be spun off again when the merger proved to be a disaster.",
"Their business model was designed around giving people an easy-to-use, easy-to-understand portal to the Internet. The inexperienced computer user needed to know nothing about ISPs, browsers, email, et cetera, because everything was done for them.\n\nAs Internet usage became more ubiquitous, users started to want to craft their own experiences, not have AOL choose for them, but the company was slow to respond to this. People preferred to pay only for access, not have their entire online life crafted for them.\n\nThey're not gone, though. There are lots of people who need or want the extra help in navigating the Internet and are willing to pay for that help. As of 2012, AOL is still worth over $2 billion, which isn't pocket change.",
"They bill themselves as a content provider. Their dial up business is just not something done anymore thought they still draw in large amounts of money from it.",
"Google, Microsoft, Apple, Facebook and a dozen other things happened. What happened to AOL is, it failed to keep up with the advances in technology. "
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
3jyt6d
|
How did Nomads survive in Siberia?
|
Also, how did people survive in places such as Ireland and England prior to settling?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3jyt6d/how_did_nomads_survive_in_siberia/
|
{
"a_id": [
"cutiplu"
],
"score": [
8
],
"text": [
"[Nomads still survive in siberia](_URL_0_). The nenet tribe follows herd of reindeer. They eat reindeer meat, wear reindeer fur, make tents from reindeer pelts, etc etc, and presumably have been doing so for a very long time.\n\nas for pre-historic peoples in the area that came to be england and ireland, [here](_URL_1_) is a resource about various tribes that lived in that area. as to *how* they lived, it would have depended on what resources were available to each tribe based on the specific geography and ecosystem of the area in which they resided. prior to the widespread use of agriculture, which only began about 10,000 years ago (compared to the couple hundred thousand years of human existence), people lived as [hunter gatherers](_URL_2_). they hunted wildlife and foraged wild plants for food, built make shift structures out of animal skins, trees, and rocks. some were nomadic, some more sedentary. the specifics of how each group of people lived varied widely, and depended largely, again, on what particular resources were available to them based on where they lived. "
]
}
|
[] |
[] |
[
[
"http://www.bbc.co.uk/tribe/tribes/nenets/index.shtml",
"http://www.bbc.co.uk/history/ancient/british_prehistory/iron_01.shtml",
"http://hraf.yale.edu/resources/faculty/explaining-human-culture/hunter-gatherers-foragers-2/"
]
] |
|
miuhr
|
Why do dogs know our emotions and we know theirs?
|
Why does it seem that dogs are able to understand our emotions? Do their closest ancestors, gray wolves, share a similar affinity to be able to sense our emotions or have we simply bred that trait into our dogs?
And for that matter, why can we seem to understand cat and dog's emotions so well? Why can I tell when my dog wants to go outside, and why can I tell that my dog is hungry? What is the evolutionary benefit there, if there is one?
It seems like there's no real reason our minds should be able to sense animals emotions. My biology teacher told me that white people don't even have the full mental ability to differ different races features as much. So why is it that I can understand a golden retriever more easily than a person?
|
askscience
|
http://www.reddit.com/r/askscience/comments/miuhr/why_do_dogs_know_our_emotions_and_we_know_theirs/
|
{
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4,
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"text": [
"Evolutionary psychologists believe that it's all about facial expressions. Gestures aren't necessarily universal. A thumbs up is actually an insult in some cultures. What they've found though is that facial expressions are universal. Even in infants from different places all over the world the results are the same in recognizing an emotion from a facial expression. They hypothesize that these universal features evolved as a basic form of communication. Things like a dogs bared teeth can relate to a humans for the same purpose. Being able to communicate (even before language) made it advantageous.",
"Hare and Tomasello cover this interesting topic in [Human like social skills in dogs?](_URL_0_)\n\nits definitely worth a read. ",
"from what I remember from Nat Geo's [Science of Dogs](_URL_0_) (but it very well might have been Nova's [Dogs Decoded](_URL_1_)) humans and dogs evolved together in a kind of symbiotic relationship. We innately know about each other. For example, we know a dog's emotional state just by listening to the noises they make even if our eyes were closed. If you think about it, wolves do not really make noise. Dog's developed a sort of \"speech\" in order to communicate better with us.\n\nDog's are also insanely queued to the visual language that humans developed. In one of those specials they had puppies leashed to one side of the room and at the other end would be a lady and two bowls flipped over and one was hiding a treat. The puppies would look at her and she would point to the bowl with the treat. The dog would even recognize her eyes looking at the bowl and it would go to that bowl. They tried the same experiment with chimps and they just found the treat through trial and error. We know how intelligent chimps are but the dogs just know how to communicate with us. \n\nDogs and humans understand each other on a very complex level. It's just amazing to me that dog really is man's best friend. We are totally symbiotic creatures. ",
"To build on what everyone else is said here, it's important to note that modern, domestic dogs have been bred by human masters for thousands of years, so it only makes sense that breeders have chosen the most sociable and human-compatible animals to breed (especially pet breeds). So in addition to whatever mammalian empathy we may share, domestic dogs have been \"artificially\" evolved for human compatibility.",
"Evolutionary psychologists believe that it's all about facial expressions. Gestures aren't necessarily universal. A thumbs up is actually an insult in some cultures. What they've found though is that facial expressions are universal. Even in infants from different places all over the world the results are the same in recognizing an emotion from a facial expression. They hypothesize that these universal features evolved as a basic form of communication. Things like a dogs bared teeth can relate to a humans for the same purpose. Being able to communicate (even before language) made it advantageous.",
"Hare and Tomasello cover this interesting topic in [Human like social skills in dogs?](_URL_0_)\n\nits definitely worth a read. ",
"from what I remember from Nat Geo's [Science of Dogs](_URL_0_) (but it very well might have been Nova's [Dogs Decoded](_URL_1_)) humans and dogs evolved together in a kind of symbiotic relationship. We innately know about each other. For example, we know a dog's emotional state just by listening to the noises they make even if our eyes were closed. If you think about it, wolves do not really make noise. Dog's developed a sort of \"speech\" in order to communicate better with us.\n\nDog's are also insanely queued to the visual language that humans developed. In one of those specials they had puppies leashed to one side of the room and at the other end would be a lady and two bowls flipped over and one was hiding a treat. The puppies would look at her and she would point to the bowl with the treat. The dog would even recognize her eyes looking at the bowl and it would go to that bowl. They tried the same experiment with chimps and they just found the treat through trial and error. We know how intelligent chimps are but the dogs just know how to communicate with us. \n\nDogs and humans understand each other on a very complex level. It's just amazing to me that dog really is man's best friend. We are totally symbiotic creatures. ",
"To build on what everyone else is said here, it's important to note that modern, domestic dogs have been bred by human masters for thousands of years, so it only makes sense that breeders have chosen the most sociable and human-compatible animals to breed (especially pet breeds). So in addition to whatever mammalian empathy we may share, domestic dogs have been \"artificially\" evolved for human compatibility."
]
}
|
[] |
[] |
[
[],
[
"http://email.eva.mpg.de/~tomas/pdf/Hare_Tomasello05.pdf"
],
[
"http://movies.netflix.com/WiMovie/National_Geographic_Science_of_Dogs/70144621?trkid=2361637",
"http://movies.netflix.com/WiMovie/Dogs_Decoded_Nova/70148726?trkid=2361637"
],
[],
[],
[
"http://email.eva.mpg.de/~tomas/pdf/Hare_Tomasello05.pdf"
],
[
"http://movies.netflix.com/WiMovie/National_Geographic_Science_of_Dogs/70144621?trkid=2361637",
"http://movies.netflix.com/WiMovie/Dogs_Decoded_Nova/70148726?trkid=2361637"
],
[]
] |
|
amov34
|
why does eating a pound of food (or any amount) not cause you to weigh + that amount immediately after when stepping on a scale?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/amov34/eli5_why_does_eating_a_pound_of_food_or_any/
|
{
"a_id": [
"efniapz"
],
"score": [
4
],
"text": [
"It does, but typical hooman scales are horribly innacurate. Just ask any pugilist how much an average poo weighs before weigh-in."
]
}
|
[] |
[] |
[
[]
] |
||
1zchup
|
Was the split of Germany the main cause of the Cold War?
|
A question we were discussing in class, and just wondering if I forgot any points, thoughts, or viewpoints on this.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1zchup/was_the_split_of_germany_the_main_cause_of_the/
|
{
"a_id": [
"cfsoks8"
],
"score": [
2
],
"text": [
"The split of Germany was an early effect of the Cold War, more than a cause. Initially, all Germany was under the ultimate sovereignty of the Allied Control Council, where all four powers sat together and decisions were to be made by unanimous vote. For practical convenience, though, Germany was divided into four occupation zones, one for each of the four powers, where each given nation would have full control. It was intended that each power administer its zone separately and denazify it under the general principles and guidelines of the Allied Control Council. Eventually, Germany would be reunified under a democratic government.\n\nEven as early as July 1945, though, friction began to appear on Allied Control Council. Initially, Russia was holding out for satisfactory reparations from Germany and Western agreement to its demands at Potsdam. Then, when the West agreed at Potsdam, France started vetoing measures to reestablish an all-German economy, protesting they hadn't been represented at Potsdam.\n\nThe real divisions began to emerge as Britain and America began reunifying their zones' governmental and economic structure. France soon joined them, turning the \"Bizone\" into the \"Trizone,\" but Russia refused to let its zone join. In part it was because the Russian-sponsored Socialist Unity Party probably would have lost a free election; in part it was because Russia feared a free Germany would join the western military and economic block. On 20 March 1948, the Soviet representative to the Allied Control Council angrily demanded to be told about recent Western negotiations in London for the German economy; when the western representatives replied that they didn't know yet, he declared, \"I see no sense in continuing this meeting, and I declare it adjourned.\"\n\nFive days later, the Berlin blockade began.\n\nEver since then, representatives of the three western powers continued to regularly meet in West Berlin, leaving an empty seat for the Soviet delegation. As unanimous consent was required, no decisions were made except for West Berlin and for the Spandau prison where prisoners were confined pursuant to the Nuremburg trials. However, the Allied Control Council continued to be the nominal ultimate German authority until the Treaty on the Final Settlement with Respect to Germany was ratified in 1991."
]
}
|
[] |
[] |
[
[]
] |
|
j39b7
|
What are some good science books for lay folks?
|
Liberal arts background here. I've read "The Selfish Gene" and I'm currently reading Gleick's "Chaos." These are the closest books I've come to being reasonable reads for non-sciencey folks. Any other recommendations?
EDIT: Should add that I'm open to (and love) TED talks if anyone has any suggestions
|
askscience
|
http://www.reddit.com/r/askscience/comments/j39b7/what_are_some_good_science_books_for_lay_folks/
|
{
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"text": [
"Any particular field? I've recommended \"The Emotional Brain\" by Joseph LeDoux as a pretty good book on how we came to really understand the role of the amygdala in fear processing... if you're interested in neuroscience. ",
"If you're interested in physics, I'd check out Richard Feynman's [QED](_URL_0_).\n\nIt's a short book adapted from a series of lectures he gave on quantum electrodynamics. It's written and explained in such a way that someone with no physics or math background can get a huge amount out of the book.",
"The ones I've read recently (all of which I recommend):\n\n- The Immortal Life of Henrietta Lacks by Rebecca Skloot\n- The Wave by Susan Casey ([NYT review](_URL_0_))\n- Written in Stone by Brian Switek (archeology, but awesome)\n- A brief History of nearly everything by Bill Bryson"
]
}
|
[] |
[] |
[
[],
[
"http://www.amazon.com/QED-Strange-Princeton-Science-Library/dp/0691125759"
],
[
"http://www.nytimes.com/2010/09/19/books/review/Morris-t.html"
]
] |
|
11y3re
|
Who is more genetically similar to
you, your sibling or offspring?
|
askscience
|
http://www.reddit.com/r/askscience/comments/11y3re/who_is_more_genetically_similar_to_you_your/
|
{
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"text": [
"On average it is the same, namely 50%\n\nYour offspring always carries 50% of your genetic payload, while with a sibling it can range between 0% and 100%: Each off your parents gives 50% of their genes to you and their other kids. On average this means that you will share some 25% from your mom and dad each. However, it is possible that you get the sayme payload from your dad and something entirely different from your mom, or that you both get exactly the same.\n\nHowever, the extremes are highly unlikely (with the exception of identical twins).",
"Your children get 50% of their genes from you and 50% from your mate.\n\nYou get 50% from each of your parents. Your siblings also get 50% from each of your parents, but on average the overlap between siblings should be about half. So on average, you should have about 50% in common with a sibling, though in theory it could range anywhere from 100% (you get exactly the same set of genes from each parent as your sibling) to 0% (you get exactly the genes your sibling **didn't** get from each parent).",
"50% of the alleles at any given genetic locus wil be the same for ANY 1st degree relative: Sibling, Parent, Offspring\n\n25% for 2nd degree (eg grandparents, grandkids)\n\n12.5% for 3rd degree (eg 1st cousins)",
"Here is what my kid's genomes look like when compared against each other:\n\n[PIC](_URL_0_)",
"Neither one is inherently/absolutely more genetically similar or dissimilar to you.\n\n\nAs someone else said, the average shared DNA is the same, 50%.\n\n\nHowever, siblings can vary somewhat substantially from this percentage. **Your sibling might share more than 50%, or less than 50% with you.** Others have mentioned that it's theoretically possible that your sibling could share 0% or 100% with you. This is technically true but the probability of these extreme percentages is so remote that we can safely ignore it. [Here's a previous post I've written to another question that you might find interesting](_URL_0_) Generally the lowest shared percentage that any researcher would ever encounter would be in the high 30s and the highest would be in the mid 60s. In general, the percent of DNA shared between siblings is **strongly** clustered around 50%.\n\n\nHere's a sample of sibling pairs I've looked at in the past:\n\n* Sister vs. sister: n=10, average 51.567%, population std dev 2.65942\n\n* Sister vs. brother: n=21, average 49.50%, population std dev 3.70366\n\n* Brother vs. brother: n=6, average 48.67%, population std dev 3.48541\n\nHighest observed: Sister vs. sister – 57.64%\n\nLowest observed: Brother vs. brother – 40.99%\n\n\nSorry, went off on a bit of a tangent there, but anyway, in contrast to the array of percentages seen among sibling pairs, **your parent will always share 50% with you.** *Disclaimer, I am referring to nuclear DNA. Also, different sources may evaluate the sex chromosomes differently. The X chromosome is much larger in size than the Y chromosome, and so you could say that a boy (who gets his X from his mother and his Y from his father) shares more DNA with his mother than his father (as in, more base pairs because the X is a larger chromosome).* But, to keep it simple, a kid gets 23 chromosomes from the mother and 23 chromosomes from the father, period. There's no variation/fluctuation seen with this relationship like there is with sibling pairs.\n\n\nEdit, okay, additional disclaimer to stave off the flood of PMs...*Trisomies, monosomies, uneven crossing over, inbreeding, translocations, deletions, insertions, chimerism, mosaicism, many various meiotic errors etc etc etc could affect the shared percentage.* I was trying to keep my answer simple-ish. OP was asking about the genetic similarities among *typical* parent/child/sibling pairs and that is what I addressed."
]
}
|
[] |
[] |
[
[],
[],
[],
[
"http://i.imgur.com/vkd6D.jpg"
],
[
"http://www.reddit.com/r/askscience/comments/11dgcf/is_there_a_1_in_246_that_two_non_twin_siblings/c6ln27d"
]
] |
||
1i3rvp
|
What did the armies of The Battle of Tours consist of?
|
I think that this occurred before knighthood was big in Europe and I really have no idea how the Islamic army was set up at all. What were they like? Additionally, can anyone point me to some books about this event and those preceding and succeeding them?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1i3rvp/what_did_the_armies_of_the_battle_of_tours/
|
{
"a_id": [
"cb0wkvm"
],
"score": [
4
],
"text": [
"The Muslim forces would have been almost exclusively armored cavalry with lances and long swords. They would have planned to simply charge and disperse the Frankish infantry. In the Middle Ages, infantry could usually not stand up to armored cavalry.\n\nThe Frankish infantry were arranged in a tight square and would have been as well-armored as possible with thick wood and iron shields and long swords and maybe axes. The Franks had no cavalry of note.\n\nCharles Martel positioned the Franks on a hill partially in the woods so the Muslims had trouble charging in a wedge or line and would have been disorganized when they assaulted the Frank square.\n\nAs it was, the Franks held out long enough for a raiding party to hit the Muslim camp, which caused the Muslim army to turn and flee to secure their plunder. Their commander had been killed and so they kept going all the way back to Iberia.\n\n"
]
}
|
[] |
[] |
[
[]
] |
|
1gy272
|
Is it inherently easier to see something small and nearby than something big and far away?
|
Let's say I have a drawing on a 1-square-meter sheet of paper, suspended in the air 1 meter away from me. Let's say there's also a reproduction of that drawing, blown up to 4 square meters and suspended 4 meters away from me.
Is the large drawing going to be harder to see than the small drawing? Will details be more difficult to make out? I'm under the impression that they'll both take up the same amount of space in your visual field, and thus be equally easy to see. [I was talking with someone else who disagreed with me](_URL_0_), and I couldn't understand their reasoning.
|
askscience
|
http://www.reddit.com/r/askscience/comments/1gy272/is_it_inherently_easier_to_see_something_small/
|
{
"a_id": [
"caoy0f9"
],
"score": [
4
],
"text": [
"`YouHaveShitTaste` seems to be trolling in that thread. \n\nFor someone who's young enough, and with good eyes, you're right: both drawings will occupy the same size on the retina, and thus, they'll be able to see them just as well.\n\nOlder people (after, say, 40) tend to be far-sighted: their aging crystalline lens have a hard time focusing on nearby objects. So, they'll see the faraway object more easily.\n\nI'm the opposite: being nearsighted, I have a hard time focusing on faraway objects; therefore, I'll see the nearby object more easily.\n\nMore info: [accomodation](_URL_1_).\n\nThere's also the [vergence](_URL_0_): Left to their own devices, my eyes will tend to be parallel. The closer an object is, the more the muscles will have to work to make both my eyes see the same object. So, a more distant object is slighly easier to look at. In your \"1m vs 4m\" example, I don't think it's a very important phenomenon though."
]
}
|
[] |
[
"http://www.reddit.com/r/gaming/comments/1gfi09/house_sitting_for_rich_folk_this_is_how_i_play/caju7ng"
] |
[
[
"http://en.wikipedia.org/wiki/Vergence",
"http://en.wikipedia.org/wiki/Accommodation_%28eye%29"
]
] |
|
3uqpb3
|
why do all uk plugs have three prongs/ always have an 'earth' whilst most other counties only have two prongs? (or no earth?)
|
All my plugs have three prongs, presumably one is always earth, but literally every other country I've ever been to ( mostly in Asia) only have two, does this mean there is no earth? Is this more dangerous?
Thanks in advance!! 😊
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3uqpb3/eli5_why_do_all_uk_plugs_have_three_prongs_always/
|
{
"a_id": [
"cxgyovg",
"cxgzbqv",
"cxh062d"
],
"score": [
3,
14,
2
],
"text": [
"It's due to the way the outlets are destined, in the UK, the earth/ground prong is longer than the other two, as it is inserted into the outlet, the other two holes are opened (they are closed when not in use). Appliances that don't need an earth/ground just have a plastic earth/ground prong. \n \nIn the US, our outlets don't have this safety feature, so appliances that don't need an earth/ground can save money by not needing a plastic earth/ground prong, and also not needing to add shutters to outlets saves money for the outlet manufacturers. The downside is that our outlets are always open and babies/idiots can stick metal in them.",
"In short, because UK Plugs are by far the most safe, most reliable, best designed plugs in the entire world and the rest of the world would be smart if they were to all adopt our standards.\n\n/Brit.\n\n;)\n",
"Is it anything to do with the U.K. Being on 240V? \n\nI always find it totally bizarre that American bathrooms have power outlets in them. In the UK they are kept outside of the bathroom. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
84pp63
|
how can 2 switches wired to the same light be able to turn it on and off no matter the state of the other switch?
|
There is this light along my stairs which can be affected by both switches without intervention. (AKA no "OR" gates) How is this possible?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/84pp63/eli5_how_can_2_switches_wired_to_the_same_light/
|
{
"a_id": [
"dvrcu5i"
],
"score": [
35
],
"text": [
"In household electric wiring, a three-way switch setup (common term) often involves wiring two double-pole switches a line, with the power source connected to one and the lamp connected to each other. In this case, each switch has two positions, and the circuit can be completed [or broken] by moving by moving either switch to a position that completes the circuit (or breaks it), as the current can flow from either position of the first switch.\n\n[This picture is worth a lot of words ](_URL_0_)"
]
}
|
[] |
[] |
[
[
"https://upload.wikimedia.org/wikipedia/commons/thumb/d/d0/3-way_switches_position_2.svg/300px-3-way_switches_position_2.svg.png"
]
] |
|
5q9w5w
|
why does youtube's copyright law about songs not affect lyric videos?
|
While they're useful, the videos are pretty much a reupload of the song with subtitles, and from what I've heard youtubers can get a copyright strike from as little humming a song. I understand covers since they probably fall under the "transformative" category, but I doubt lyric videos do.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5q9w5w/eli5_why_does_youtubes_copyright_law_about_songs/
|
{
"a_id": [
"dcxiwm2"
],
"score": [
3
],
"text": [
"If you make content or a music mix, you are to put the titles of songs used in your video description. Else they will will remove your video.\n\nMaking a lyric video counts as user made content (I guess). So as long you put credits in your description it should be fine."
]
}
|
[] |
[] |
[
[]
] |
|
1lwzca
|
what does it mean for austrailia now that abbot is the pm?
|
Sweeping changes? Will day to day life be affected? If so many people were against Abbot, how did he win? Is he really that bad for Austrailia?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1lwzca/eli5_what_does_it_mean_for_austrailia_now_that/
|
{
"a_id": [
"cc3kqkm",
"cc3tee3"
],
"score": [
7,
3
],
"text": [
"Tying to be as non-bias as possible. Your day to day life will not be affect aside from the fact that you might pay slightly higher taxes / you might receive slightly less services. A lot of people were against abbott on the internet because people who are technologically advanced are often Labor supporters; they probably support because of the broadband policies. Most of the technology illiterate do not care for the broadband policies and likely voted for the liberal coalition.\n\nIt is by all means not going to be the end of the world. It isn't that bad for Australia. The hard working spirit and the sheer toughness of Australia is what got us where we are and no political party will ever be able to tear that down.",
"Brief overview is that Tony Abbott:*\n\nHates the gays wanting to get married\n\nHates people that come to seek asylum by boat\n\nDoesn't give a shit about technological advancements (internet, science, medicine)\n\nWont outline any policies about bettering education\n\n\nHe is bad but the alternative isn't that much better so it is like picking between Romney and Obama for you Americans"
]
}
|
[] |
[] |
[
[],
[]
] |
|
mrkky
|
How does time near the speed of light work for two different frames of reference?
|
Ok, so I know the classic example of an astronaut leaving earth traveling at near the speed of light and then returning to find that time has passed much quicker on earth than in his speedy spaceship.
However, in my astronomy textbook it says that if there are two bodies moving relative to each other and each body had its own clock, both clocks would appear to be ticking slower than the other, depending on which frame of reference you take.
So, my question is this: Wouldn't the people on earth be traveling at near the speed of light relative to the astronaut and thus be experiencing time at a slower rate from their perspective than the astronaut?
|
askscience
|
http://www.reddit.com/r/askscience/comments/mrkky/how_does_time_near_the_speed_of_light_work_for/
|
{
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"text": [
"Ah this is the classic [twin paradox](_URL_0_).\n\nSpecial relativity states that reference frames that are uniform are equivalent. i.e. they are either traveling at a constant speed or stationary. \n\nThe thought experiment is: if you are on a bus that's traveling at a constant speed, it is indistinguishable from if you are stationary. You can construe yourself as being stationary and the whole world is moving backwards at the constant speed.\n\nBut the moment the bus accelerates or decelerates, you will be jolted forwards or backwards (this leads to general relativity, beginning with the equivalence of accelerating frames and gravity). \n\nSo in this case, the astronaut has to accelerate out, decelerate *and then* make a round-about change in direction. The people on Earth stay stationary relevant to the astronaut and experience no such accelerations/decelerations/change of direction. The two reference frames are no longer equivalent.\n\nThis proves to be an simplification - more details are provided in the link above.\n",
"This is the reason that the [twin paradox](_URL_0_) is called a paradox. The astronaut on his journey will see time progress slowly on earth- however, when he turns around to come back to earth, he changes his frame of reference. When he changes frame of reference, many of his coordinates get relabeled. In a sense, he sees the earth experience a whole lot of time at once.\n\nOf course, there's nothing discontinuous about what the astronaut actually -observes-, when we write 'sees' we mean that the astronaut corrects his observations based on the speed of light. The astronaut -observes- time passing faster on the earth when he travels back towards it, because he's travelling into the oncoming light beams. When he corrects for the distance between him and the earth, however, he finds the same thing he found on the way out, that time is passing more slowly on the earth than for him.\n\nThe wikipedia link has more material about this under the 'resolution' section.\n\nEdit: It seems I was beaten by an equivalent explanation. Perhaps I shouldn't write responses while travelling close to the speed of light.",
"Ah this is the classic [twin paradox](_URL_0_).\n\nSpecial relativity states that reference frames that are uniform are equivalent. i.e. they are either traveling at a constant speed or stationary. \n\nThe thought experiment is: if you are on a bus that's traveling at a constant speed, it is indistinguishable from if you are stationary. You can construe yourself as being stationary and the whole world is moving backwards at the constant speed.\n\nBut the moment the bus accelerates or decelerates, you will be jolted forwards or backwards (this leads to general relativity, beginning with the equivalence of accelerating frames and gravity). \n\nSo in this case, the astronaut has to accelerate out, decelerate *and then* make a round-about change in direction. The people on Earth stay stationary relevant to the astronaut and experience no such accelerations/decelerations/change of direction. The two reference frames are no longer equivalent.\n\nThis proves to be an simplification - more details are provided in the link above.\n",
"This is the reason that the [twin paradox](_URL_0_) is called a paradox. The astronaut on his journey will see time progress slowly on earth- however, when he turns around to come back to earth, he changes his frame of reference. When he changes frame of reference, many of his coordinates get relabeled. In a sense, he sees the earth experience a whole lot of time at once.\n\nOf course, there's nothing discontinuous about what the astronaut actually -observes-, when we write 'sees' we mean that the astronaut corrects his observations based on the speed of light. The astronaut -observes- time passing faster on the earth when he travels back towards it, because he's travelling into the oncoming light beams. When he corrects for the distance between him and the earth, however, he finds the same thing he found on the way out, that time is passing more slowly on the earth than for him.\n\nThe wikipedia link has more material about this under the 'resolution' section.\n\nEdit: It seems I was beaten by an equivalent explanation. Perhaps I shouldn't write responses while travelling close to the speed of light."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Twin_paradox"
],
[
"http://en.wikipedia.org/wiki/Twin_paradox"
],
[
"http://en.wikipedia.org/wiki/Twin_paradox"
],
[
"http://en.wikipedia.org/wiki/Twin_paradox"
]
] |
|
2a5vqx
|
what is the physics explanation behind 3d technology?
|
I recently completed a rigorous physics course that involved a few chapters on optics and light, and ever since I've been trying to figure out on my own how the 3D effect is produced. Anyone know?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2a5vqx/eli5_what_is_the_physics_explanation_behind_3d/
|
{
"a_id": [
"cirsamw"
],
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3
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"text": [
"One of the most compelling ways to convince the brain that you are seeing something that is 3D when it is actually an image on a flat surface is to feed a different image into each eye. This is how the old red/blue 3D glasses work—they project both images on the same surface but they are tinted different colors so you only see one of the images with each eye.\n\nMany other 3D technologies largely works the same way. Most 3D cinema experiences are done using polarized lenses. It's a bit rough to fully describe what polarized light is, but essentially light can be either clockwise or counterclockwise, if you will. Most light is a mixture of both, but you can make a filter that only allows one or the other through. They project the image for one eye using one polarity and for the other eye using the other polarity; the glasses you wear have filters that block one or the other. Next time you're in the theater look at someone else who's wearing the glasses and close one eye. You'll be able to see through one side of their glasses just fine but not the other.\n\nA lot of computer gaming 3D effect and the 3D effect on home theater systems is often done with \"shutter glasses.\" They have the ability to quickly alternate between clear and opaque. The TV or Monitor can flash an image for about 1/120 of a second while one eye is allowed to see out, then they flash the corresponding image meant for the other eye while that eye is allowed to see. Once again this is based on feeding a different image to each eye.\n\nThere are other effects that some systems use. For example, if the system can track the movement of the viewer relative to the screen then it can redraw the scene as if it were being observed by someone who has moved over. This can give you the effect of looking \"around\" an object in an image and can support the illusion of 3D.\n\nThere's really not a lot of actual optics that is involved in creating the 3D illusion. Your brain judges distance partially by using the focus of your eyes, but it's not really practical to use that when trying to make something look 3D. I've only ever seen this approach at an optometrist. In fact, the mismatch of focus with apparent distance is one of the stronger things that makes the 3D illusion fail and can contribute to the motion sickness and headaches that some people get when experiencing 3D media. "
]
}
|
[] |
[] |
[
[]
] |
|
11tj8v
|
What are the environmental benefits to bringing wolves back to most of their native habitats?
|
Long story short i got into an argument with another student in one of my classes, he was deeply entrenched on the subject that all wolves should be killed "our ancestors killed them off for a reason", and that they are a huge drain on money and manpower for any rancher. I am trying to become a biologist and was embarrassed when i had no information on the benefits they have.
Edit: i have no idea how to tag this as biology, is there an faq on how?
|
askscience
|
http://www.reddit.com/r/askscience/comments/11tj8v/what_are_the_environmental_benefits_to_bringing/
|
{
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"text": [
"This is an important recent study that you should read about trophic cascades between wolves, elk and aspen in Yellowstone. Basically, having a top predator back in the system has effects on all trophic levels of the ecosystem: _URL_0_",
"Apex predators (\"top of the food chain\") are very important ecologically for keeping numbers of other animals in balance. Think of the deer overpopulation problem most areas have: not only do they cause auto accidents, but also help spread diseases like Lyme. Predators are also beneficial in maintaining herd health, as they preferentially kill \"easy prey\" (old, injured, sick, diseased) while healthy animals escape and thrive. While human game hunters help with prey overpopulation, they tend to choose healthy, robust animals, and leave diseased ones which isn't particularly good for the overall health of the herd and likewise public health. Wolves also help provide food for scavenging carrion animals (vultures, etc).",
"_URL_0_\n\nThe above review/research article looked at how the removal of wolves and reintroduction of wolves affects ecosystem structure and function through a trophic cascade. A tropic cascade is the cascade of effects that result from removing one species, usually a top predator, from an ecological system. The effects of this removal or reintroduction can have cascading effects on all of the levels of organisms below them, right down to the microbes in the soil. \n\nThese researchers reviewed the literature and found that top carnivores, and wolves in particular, have been shown to indirectly affect the growth of some plant species, and the number of species present in an ecosystem. Wolves do this by forcing large herbivores like moose, elk and deer to \"forage optimally\", that is, to choose between which plants to eat, and how much to expose themselves to being eaten by a wolf. When wolves are removed from that equation, herbivores need not worry, and so browse more freely, reducing or removing some plant species. When wolves are reintroduced into an area where they were removed from, this pattern stops, and plant species that were once rare become more common. \n\nThis alteration in foraging by large herbivores not only affects plant species, but, as their research showed, can affect other, less directly related species as well. When wolves are removed from riparian areas (stream habitats), large herbivores browse these areas more intensely. This reduces the amount of food available to beavers, and so beaver populations fall. Researchers have also found that removal of grizzly bears and wolves from the Tetons in North America has been correlated with a reduction in migrant birds and small mammals.\n\nThus, reintroduction of wolves can alter the abundance and diversity of a multitude of species, which can enhance ecosystem function and possibly ecosystem services (those things ecosystems provide to humans).\n\nTL; DR: The presence of wolves has a cascading effect on the entire ecosystem, from the herbivores to the soil. Reintroduction of wolves has been shown to improve biodiversity and alter ecosystem structure and function.",
"All the responses in this thread are great and dead on. I'm an ecologist and have worked with/know a lot of researchers and managers at the forefront of the wolf issue in the West, including two of the authors in the study posted above. There are two things to add that haven't yet been mentioned. Most hunters complain about coyotes, and also often incorrectly believe that higher wolf numbers will result in a reduction of deer numbers through direct predation (thus reducing their hunting opportunities). Firstly, in most natural food webs, coyotes are the primary prey item for wolves, and thus their numbers would be greatly reduced by a reintroduction. Secondly, direct predation from wolves and other large predators (such as cougars), only accounts for 3-5% of deer mortality - so virtually no effect. Most people don't realize that deer populations are already deliberately managed at unnaturally high numbers specifically to provide hunting opportunities. Yes, reintroducing wolves will work to reduce deer and elk numbers, but only indirectly through the trophic cascade (mentioned earlier) vis-à-vis reduction of quality browse. However, wildlife and game managers who reintroduce wolves into a given area will obviously adjust the deer and elk populations to accordingly. They do this mostly by changing the number and type of hunt tags they give out. It generally takes a couple years for the populations to adjust, but the majority of fluctuations in deer and elk populations occur naturally in cycles about every 7 years or so, and are completely out of our control. There are more effective techniques for managing these populations that would actually provide more hunting opportunities, but good luck getting them past the ignorant public. As far as the problem with ranchers goes, that's a tough one and nobody really has a great solution yet. I say that ranchers, as they already do, should get reimbursed for a proven wolf kill. But I think if wildlife agencies are reintroducing wolves into areas that haven't had them for a century or more (ie before those ranchers were there), then maybe we could provide them a modest subsidy for the inconvenience. After all, they're taxpayers too and likely hunters who benefit from it. Plus, we gotta have ranchers, so society has to support them somehow. Anyway, my two cents. "
]
}
|
[] |
[] |
[
[
"http://www.cof.orst.edu/leopold/papers/2001trophiccascades.pdf"
],
[],
[
"http://www.bioone.org/doi/abs/10.1641/0006-3568%282004%29054%5B0755:WATEOF%5D2.0.CO%3B2"
],
[]
] |
|
6utfhy
|
what did the idea of "Gross" look like before the development of germ theory? how quickly did germ theory change the daily habits of common people?
|
[deleted]
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/6utfhy/what_did_the_idea_of_gross_look_like_before_the/
|
{
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],
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"text": [
"I\"m only a dabbler in historical knowledge, but in this case I think you may be looking for more of an anthropological or sociological answer. The thing is that even with modern germ theory a lot of this comes down to culture and in my limited experience is often cast through the lens of religion - Emile Durkheim immediately springs to my mind based upon your question with his focus on Taboo. Unfortunately, the only actual material I've seen which might qualify for /r/askhistorians for this type of question is of quite a dubious nature generally involving conjectures for why such-and-such group has whatever taboo which modern science tells us would have been a great way to avoid problems caused by issues not understood historically.\n\nI might be misreading your question though as I'm really just focusing on the first half which is a wee bit broad and an actual Historian might be able to chime in with an answer to the second part for at least some parts of the world."
]
}
|
[] |
[] |
[
[]
] |
|
2hlnz2
|
how do testicles not get wrapped around each other inside the scrotum?
|
I need to know, I'm kind've terrified by the notion of them getting twisted together.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2hlnz2/eli5_how_do_testicles_not_get_wrapped_around_each/
|
{
"a_id": [
"cktsyqu",
"ckttg0e",
"cktvoic"
],
"score": [
6,
12,
2
],
"text": [
"They can. It's called testicular torsion.",
"Your balls are seperated by a thin wall so they cant tangle each other. However one testicle can twist around itself causing testicular torsion.",
"Ok, most envision testicles like a ball on a string, your vein being the string and the ball being.. *well, you know.* this isn't anatomically correct. Imagine... *Bassett hound ears*: flat, elongated and droopy, *THAT* is what the tissues surrounding a testicle reminds me of. Although one could physically twist testicles, they typically rotate and adjust back to their original position. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
73j5i7
|
why can’t video games make walking/running look realistic?
|
Video games have seen major innovations in recent years, with incredible graphics, new forms of interaction like VR, and more complicated algorithms.
But while playing FIFA 18, I noticed that players running around still have the illusion that their feet are sliding around. It seems that their feet are never actually planted, and the game just coordinates their movements and positions rather than have the player realistically run within out the feet sliding around when they change direction.
tl;dr: Why can’t video games like FIFA, 2K, Madden make running look realistic?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/73j5i7/eli5_why_cant_video_games_make_walkingrunning/
|
{
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"dnqplba",
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"text": [
"there are generally 2 ways to do this:\n\n- Physics simulation: use the momentum of the character to calculate where the legs/feet should go in order to provide the proper change in direction. In real time.\n\n- Create a seperate animation for every single possible leg position, body position and movement change that the physical body is capable of doing, as well as create a system that determines the correct animation to play. (Pretty much all games use a severely cut down version of this, as animations take a long time to make)\n\nA lot of work for something most people wont care about.",
"A lot of movement animation is captured live with peoples' actual body movements ([Example](_URL_0_)) and then these are applied to the character's animation when moving in-game.\n\nThe problem comes because many states/actions can make the player run faster/slower (such as sprinting vs. walking, as well as changing directions in many different angles) and the studio can only capture so many animations to account for that. After that it comes down to using mathematics to calculate where body parts should be, or trying to find the \"most appropriate\" animation for whatever action a player is doing and a lot of the time this isn't perfect, and thus things like running animations are not perfect with the speed that the feet move in, etc.",
"You can see some work towards making it look more realistic here: _URL_0_. (That's commentary on the work. For a video made by the actual researchers, see here: _URL_1_.)"
]
}
|
[] |
[] |
[
[],
[
"https://youtu.be/Rpr1SIvL4Gg"
],
[
"https://youtu.be/wlndIQHtiFw",
"https://youtu.be/Ul0Gilv5wvY"
]
] |
|
du6q8a
|
Why was Australia not discovered by the Chinese first?
|
From a geographical standpoint, it would be alot easier for the Chinese to find Australia before the English.
How did they not stumble across it first?
Is there any record of them finding it?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/du6q8a/why_was_australia_not_discovered_by_the_chinese/
|
{
"a_id": [
"f72l2ia"
],
"score": [
32
],
"text": [
"I am not an expert on China, and can't say much about Chinese sea-faring. I can however correct a few misconceptions here.\n\nIndigenous Australians first discovered Greater Australia at least 60,000 years ago.\n\nVisits from Austronesian seafarers in the last 1000 years are likely, evidenced by the introduction of the dingo and the difference in languages in northern Australia.\n\nThe people of the Torres Strait Islands had constant contact with New Guinea and northern Cape York.\n\nVisits by Indonesians are likely but unconfirmed until much later (starting in the late 1600s). These were Makassan fishermen from Sulawesi, who harvested sea cucumber for the Chinese market. \n\nVisits by the Spanish and Portuguese around the late 1500s are also likely but unconfirmed. The first confirmed non-Indigenous visitor to Australia is the Dutchman Willem Janzsoon, who landed in Cape York in 1606 just months before the Spanish Luis Vaz de Torres sailed the strait between New Guinea and Australia. \n\nFive years later the Dutch pioneered the Brouwer route across the Indian Ocean (a faster but less predictable route to Indonesia), which elicited a flurry of Dutch explorers and shipwrecks on Australia's coasts, with their last voyage of discovery by Abel Tasman in 1644 revealing all but the east coast of Australia and the Bass Strait. Other important events include the horrific Batavia Disaster, and Willem de Vlamingh's voyage up the Swan River in 1697.\n\nThe first English explorer was William Dampier in 1699, after nearly a century of Dutch exploration of Australia. His books inspired many English navigators, including James Cook and Joseph Banks.\n\nThe Chinese may have visited in the early 1400s during Zheng He's great expeditions, but there is no evidence for this. It would also be unlikely to have changed Australian history much, beyond some local variation in Indigenous culture - the only visitors to bring significant change to Australia prior to British invasion were the Makassans, who maintained centuries of return visits, face-to-face interactions and coastal activity.\n\nGood books to read on this are:\n*The First Footprints* by Scott Cane, discussing prehistoric Indigenous Australia (also has a great documentary version showcasing amazing art and locations)\n\n*The Savage Shore* by Graham Seal, which looks at the voyages of European maritime explorers and discusses possible visitors as well."
]
}
|
[] |
[] |
[
[]
] |
|
6ghn45
|
So what would happen if you took off your helmet on mars? It has a form of an atmosphere so I wouldn't imagine it'd be the same effect as space. How long would you have to live and what's the most likely cause of death?
|
askscience
|
https://www.reddit.com/r/askscience/comments/6ghn45/so_what_would_happen_if_you_took_off_your_helmet/
|
{
"a_id": [
"diqxs8x"
],
"score": [
17
],
"text": [
"It does have an atmosphere, but its density is so low that for all practical purposes (at least from the point of view of human respiration) it is equivalent to a vacuum.\n\nThe effect will be exactly the same as in space: Your lungs lose oxygen instead of gathering it. After like 15 seconds this deoxygenated blood reaches your brain and you lose consciousness. Your last memory before passing out will be saliva boiling (at normal human body temperature due to the low pressure) on your tongue. Then your rescuers only have like 1 or 2 minutes to take you back to a pressurized environment before asphyxia becomes lethal.\n\nAs opposed to popular belief, you do not explode and blood does not boil.\n\nThis actually happened to NASA astronaut Jim LeBlanc when they were testing EVA suits in a vacuum chamber on Earth. Due to a failure his suit lost pressure (IIRC it was a pipe that detached). Fortunately the chamber could be repressurized quickly and so he survived with no permanent injury.\n"
]
}
|
[] |
[] |
[
[]
] |
||
xf8n5
|
Explain this hoverboard design and why I shouldn't get excited.
|
_URL_0_
|
askscience
|
http://www.reddit.com/r/askscience/comments/xf8n5/explain_this_hoverboard_design_and_why_i_shouldnt/
|
{
"a_id": [
"c5ltxjr",
"c5lugso",
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],
"score": [
9,
39,
9
],
"text": [
"Looks like it's based on electromagnets, which if I'm not mistaken means for you to go all back to the future with it would require roads that would produce a magnetic field to repel against. ",
"Supermagnets spinning over expensive copper slabs. Yes real. Here's my [1995 demo version](_URL_1_)\n\nHere's a man-lifting version from [Korea] _URL_0_\n\nOnly trouble is, this is Maglev Train technology: it requires a track, and it needs about a kilowatt to lift an average person. The track gets hot from eddy current loss.\n\nSo wait until the roads are covered with inch-thick aluminum slabs. Also wait until \"Mister Fusion\" is built inside a somewhat thick-ish skateboard. That, or wear a heavy backpack full of NiMH batteries. (But maybe someone will save the day by inventing a superconductor that doesn't need liquid nitrogen temperatures.)\n",
"I don't think anyone who has made one of these had EVER consulted someone who actually skates. This would be the equivalent of watching a horse scurry around on ice. Wheels will forever dominate because they make sense. That science fiction movie only made it look cool. That's all. In actual use, it is far more limiting than a regular skateboard."
]
}
|
[] |
[
"http://hoverboardproject.com/"
] |
[
[],
[
"http://www.youtube.com/watch?v=uHEQgjNcFBo",
"http://www.youtube.com/watch?v=glCNP6qH_Dc"
],
[]
] |
|
395770
|
When did humans realize clouds are evaporated water?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/395770/when_did_humans_realize_clouds_are_evaporated/
|
{
"a_id": [
"cs0rgp7"
],
"score": [
2
],
"text": [
"We had a thread similar to this a few months back. From [What did people think clouds were before we could scientifically describe them?](_URL_0_), /u/RomeosDistress quotes Augustine of Hippo (354-430 CE):\n\n > The clouds, according to the testimony of those who have walked through them in the mountains, have this vaporous appearance, formed, as they are, of the most minute drops which are gathered and rolled together. And if further condensation takes place, so that one large drop is formed out of many small ones, the air, unable to support it, yields to its weight as it travels, down, and this is the explanation of rain. (The Literal Meaning of Genesis (De Genesi ad Litteram), Volume 1, Book Two, Chapter 4)\n\nThat gives a *terminus ante quem* for associating rain, clouds, and water vapor. The earliest proposed date in that thread is before 600 BC (*The Iliad*)."
]
}
|
[] |
[] |
[
[
"http://redd.it/2fenjh"
]
] |
||
34fd0c
|
How factionalized was the German government during Nazi rule and how did factional infighting affect the war effort?
|
I read a biography on Reinhard Heydrich and I was surprised by the sheer amount of competing factions in the Nazi government. However since the biography did focus on Heydrich, the book only mentioned political factions when it concerned Heydrich's power. How many factions were there, how influential were these factions, and did this factional infighting affect the out come of the war.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/34fd0c/how_factionalized_was_the_german_government/
|
{
"a_id": [
"cqu4e77"
],
"score": [
2
],
"text": [
"An interesting source here is Albert Speer's *Infiltration*; Speer was Hitler's Minister of Armaments after 1942, and the book is largely about the way Himmler's SS and the Ministry of Armaments kept butting heads. To hear Speer tell it, Himmler's efforts to build a postwar power base--the SS has been well described as a state within a state--kept sabotaging Speer's efforts to run a war. \n\nI don't actually recommend reading *Infiltration,* but here are some examples from it:\n\nHimmler kept having the Gestapo (which he controlled) arrest prisoners on trumped-up charges; these prisoners were working in Speer's factories but would then wind up in SS-run factories. So the arrests were a way of poaching labor away from Speer. \n\nThat was part of a larger power struggle over what to do with prisoners, Jews, and so on; Speer makes it clear that he never saw them as anything except a resource to be used (\"Today, almost forty years later, I grow dizzy when I recall that the number of manufactured tanks seems to have been more important to me than the vanished victims.\") But that makes him seem like an absolute saint in contrast with Himmler (and Goebbels's) plans involving extermination and enslavement for its own sake. He makes a good case that the production in SS factories and places like Auschwitz was pathetically low, so every time Himmler got prisoners that could have gone to Speer the war effort suffered.\n\nBoth Speer's ministry subordinates and the industrialists who actually ran the factories kept running afoul of the SS; although Speer was mostly able to protect his people, the impression he gives is that if he had fallen from power, Himmler was ready to arrest his top people and take over. It's not clear how much that climate of fear interfered with productive efficiency, but it can't have helped.\n\nSpeer was (to hear Speer tell it) not a fan of crank plans like making rubber out of dandelions or oil out of trees, while the promoters of these plans had a ready ear in Himmler; precious resources were wasted on these ideas.\n\nInterestingly, according to Speer this infighting never stopped--there was never a point at which anyone said, hey, the Russians are next door and we need to get serious:\n\n > Everywhere, the battle for jurisdictions was being fought even in the final weeks, between ministries and in the intermediate agencies, as though the Reich were invincible. "
]
}
|
[] |
[] |
[
[]
] |
|
9tphc1
|
usage factor on electricity bill
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9tphc1/eli5_usage_factor_on_electricity_bill/
|
{
"a_id": [
"e8y53se"
],
"score": [
2
],
"text": [
"Some electrical companies charge you based on \"demand\" or \"peak\" or \"load\", rather than a flat rate. \n\nSo, basically, when you consume your kwh at night, the power plant is not busy and can easily supply it, but if you consume it during the day, they also have to supply a lot of businesses, so that means more effort on their part to keep the businesses powered up, AND you at the same time. Or at least that's their justification.\n\nSo, we don't know, but you have a couple possibilities:\n\n* Daytime kwh's cost you more than night-time kwh's, and the new meters they have nowadays can keep track of WHEN you consume your electricity.\n\n* Or, getting close to your \"limit\" costs you A LOT more. Like, 0 - 50% of what you're allowed, costs you $1 per kwh. 50% to 75% costs you $2, 75% to 90% costs you $5, and 90% - 100% costs you $10 per kwh.\n\nYour best bet is to call the utility company and have them explain the bill to you. It sounds like they're charging you based on the \"usage factor\" - 0.617 is about 3x 0.225, so your bill is about 3x bigger. They aren't charging you based on the raw kwh.\n\nSo have them explain to you what this \"usage factor\" actually is."
]
}
|
[] |
[] |
[
[]
] |
|
2utepi
|
why when a drop of water lands on a piece of paper and it dries the paper is left wrinkled at that spot.
|
Smooth paper is left wrinkled when exposed to water. It seems to happen to every kind of paper. What is happening to cause the wrinkles? Why doesn't it flatten out again when it dries?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2utepi/eli5why_when_a_drop_of_water_lands_on_a_piece_of/
|
{
"a_id": [
"cobl233"
],
"score": [
3
],
"text": [
"I have no evidence but my thought is that the fibers of the paper likely swell and rearrange themselves as they push outward in their swelling. Try getting a piece of paper wet and leaving something quite heavy on top of it to see if that changes the result"
]
}
|
[] |
[] |
[
[]
] |
|
ash2kw
|
How are underwater tunnels built? (Such as the one from Copenhagen to Malmö) Additionally, what steps and precautions are taken to ensure it will not flood both during and after construction?
|
askscience
|
https://www.reddit.com/r/askscience/comments/ash2kw/how_are_underwater_tunnels_built_such_as_the_one/
|
{
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"text": [
"This is called an *immersed tube tunnel*. The first thing to do is to cut a trench in the seafloor along the route of the tunnel. Meanwhile, prefabricated sections of the tube are built in dry docks from steel or reinforced concrete. These are then sealed at each end with temporary bulkheads and floated to the construction site. When it is in the correct location, the tube is ballasted and sunk to the seabed alongside the previous section of tube. \n\nThe two sections are linked using rubber seals and the bulkheads removed. Then the tube is covered with gravel which weighs it down on the seafloor and prevents it being damaged by ships. The next section can then be moved into position. This site has some nice graphics about how it has been done including in Scandinavia.\n\n[_URL_2_](_URL_2_)\n\nImmersed tubes only really work in shallow waters. For deeper channels the tunnel - until now - has been cut into the bedrock below the seafloor using a tunnel boring machine. However, the Norwegians are looking at a *submerged floating tunnel* to cross the Sognefjord. Here, the tunnel actually hangs in the water from giant floats - the idea has been around for a long time, but no one (and I really can't think why anyone would have a problem of being in a tunnel hanging in the middle of the ocean) has yet built one. There's a list of proposed projects here:\n\n[_URL_0_](_URL_1_)",
"It can also be done with a earth pressure balance machine , it's a tunnel boring machine with a pressurized cutting head. The tunnel liner is constructed inside the machine & pushed out the back as it advances. [_URL_0_](_URL_0_)\n\nIn New York the water tunnels are a 1000 ft deep & in granite, they drill ahead of the TBM & grout the cracks in front of the machine before it passes.",
"The BART (Bay Area Rapid Transit) Trans Bay Tube connecting SF with Oakland is an underwater tube, it was completed in 1969. There is an anchor exclusion zone over the top of the tube; ships are prohibited from dropping anchor in the vicinity of the tube.\n\nThere is a good wiki about the BART tube here: _URL_0_",
"/u/iCowboy's answer is rather good. Since you specifically mentioned the [Øresund bridge](_URL_0_) and tunnel, I'm just adding this answer to link you to [a Megastructures episode](_URL_3_) specifically about that structure.\n\nIt's also worth noting that this is not the only way to construct underwater tunnels; the [Channel Tunnel](_URL_1_) between Britain and France [was built](_URL_6_) using [tunnel boring machines](_URL_2_).\n\nAnd finally, just for fun, [here](_URL_4_)'s another video about [an undersea tunnel in Korea](_URL_5_) built using the immersion method.",
"A simple explanation can be found [here](_URL_1_). It's for a planned tunnel between Denmark and Germany but the same technique had been used at the Øresund connection.\n\nAlso available as a video _URL_0_\n",
"I work underground in a mine in Canada, we use a machine called a boomer to drill 16ft sections and load with explosives and blast. After we clear the blown ground we use a screen and bolts drilled into the ground to stop it crumbling. We have tunnels all over the place and are currently 1000m down from surface and going deeper. Also we are under a couple of lakes.\nI would think we could make a tunnel under and ocean that way.",
"The tunnels for the new subway under the Anacostia river in DC ... there was nothing but mud for them to go through, with nothing but sand underneath ... so the engineers devised this fantastical all-in-one machine which bored the hole, set rebar, poured fast-drying concrete, and dried it all in one operation. that was a number of years ago, I don't know if you can find anything on the internet about it anymore or not.",
"It's worth mentioning [Marc Brunel's Rotherhithe Tunnel,](_URL_1_)under the river Thames, the first to be built under a navigable river. The main innovation was the newly invented [tunnelling shield](_URL_0_), a combined platform for the diggers and a temporary liner that was jacked forwards as the tunnel progressed. Bricklayers followed behind it, building the permanent lining. \n\nMarc Brunel's more famous son, Isambard Kingdom Brunel was the resident Engineer for much of the project.\n\nThe tunnel is still in use, carrying a part of the London Underground tube/subway system.",
"In addition to the methods others have listed, they can also do the [Drilling and Blasting](_URL_0_) method and then excavate the rubble. I believe the two undersea tunnels in the Faroe Islands were partially excavated by this method, and there's a third tunnel currently under construction that they've done some blasting and excavating.",
"When the access cavern for the Large Hadron Collider's CMS detector was dug at CERN, they had to literally freeze the ground. They needed to dig 100m down but the water table was around 20m down, which made the whole thing unstable. So they pumped cooled brine and then liquid nitrogen (-195°C) around the shafts and froze it. \nFunny story was that the frozen ground caused a car driving on a nearby road to slip on a sheet of ice and crash. It being the height of summer, the insurance didn't believe the road was icy and denied coverage. The driver had to get a special letter from CERN attesting to the frozen ground",
"During Boston's Big Dig project they pioneered a new underwater tunneling technology. They prefabricated cement sections of tunnel floated them out to where they were needed and sunk them (inundating the tunnel with water). Once all the sections were sunk (and flooded), they sent divers to seal the sections together, then they pumped all the water out of the tunnel and added the required infrastructure (lights, electrical, etc).\n\n & #x200B;\n\nNote: I'm having a bit of trouble finding a source corroborating my memory, so take it will a small grain of salt."
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Submerged\\_floating\\_tunnel",
"https://en.wikipedia.org/wiki/Submerged_floating_tunnel",
"http://www.railsystem.net/immersed-tube-tunnel/"
],
[
"https://www.youtube.com/watch?v=9oZqYLGNzKE"
],
[
"https://en.wikipedia.org/wiki/Transbay_Tube"
],
[
"https://en.wikipedia.org/wiki/%C3%98resund_Bridge",
"https://en.wikipedia.org/wiki/Channel_Tunnel",
"https://en.wikipedia.org/wiki/Tunnel_boring_machine",
"https://www.youtube.com/watch?v=sufr9mMxPW8",
"https://www.youtube.com/watch?v=Xr2HAJXPP2A",
"https://en.wikipedia.org/wiki/Busan%E2%80%93Geoje_Fixed_Link",
"https://www.youtube.com/watch?v=cVJ45QxESYs"
],
[
"https://youtu.be/_XUiMncXp7A",
"https://femern.com/en/Construction-work/Production-site-at-Rodbyhavn"
],
[],
[],
[
"https://en.wikipedia.org/wiki/Tunnelling_shield",
"https://en.wikipedia.org/wiki/Thames_Tunnel"
],
[
"https://en.wikipedia.org/wiki/Drilling_and_blasting"
],
[],
[]
] |
||
1lvwud
|
Why is thunder a low-pitch rumbling instead of a high-pitch blast?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1lvwud/why_is_thunder_a_lowpitch_rumbling_instead_of_a/
|
{
"a_id": [
"cc3dx5c"
],
"score": [
8
],
"text": [
"Audio engineer here, I would think it has to do with the wavelength of the different frequencies of the audible frequency band. Lower sounds (bass) have much longer wavelengths, and therefore do not produce a full wave (compression/rarefaction) until a much greater distance than high frequencies. When standing close to the strike (like a hundred yards or so), you will hear the higher pitched crash first, as these waves have a shorter wavelength, and produce \"sound\" within a shorter distance. When standing a few miles away, the higher frequencies have used all their power and dissipated closer to the source, whereas the lower frequencies are able to travel much farther with their longer wavelengths, and you hear the low boom."
]
}
|
[] |
[] |
[
[]
] |
||
eu6n77
|
how/why does it benefit the us dollar when saudi arabia uses it exclusively when selling oil? also, why do a lot of places outside of the us accept/favour the us dollar?
|
Why does the US want Saudi Arabia to sell oil exclusively using the US dollar? Also, why do a lot of places outside of the US accept/favour the US dollar? Is there something particularly special about it?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/eu6n77/eli5_howwhy_does_it_benefit_the_us_dollar_when/
|
{
"a_id": [
"fflyde2",
"ffme74h"
],
"score": [
4,
4
],
"text": [
"If the dollar weakens, a barrel of oil will still cost the same amount for American customers.\n\nThe price paid will only be based on the oil market at the time, rather than how many pounds, euros, etc the dollar is worth.",
"At any given time, there is a limited supply of dollars in the world. Not just a limited amount of bills and coins, but a limited amount of currency that includes money that just exists as numbers in computers. This number is controlled by the Federal Reserve, the central bank of the United States.\n\nIf a lot of people want to use US dollars to buy things, then I can sell you my US dollars at a higher price. Because, if you don't want it, I can probably find another buyer for them. Whereas you may not as easily find another seller, if US dollars are in high demand. On the other hand, if few people are interested in USD, then I'll have a hard time finding a buyer for my dollars, and will probably have to lower my price to get someone willing to take them off my hands.\n\nThe more people use the USD, the higher demand for it will be. Oil is a popular good that many people want to buy. If everybody who wants to buy oil needs USD to do it, then that demand will drive up the price of the USD. It's also beneficial to America because it means that the price Americans pay for oil isn't (directly) influenced by fluctuations in the currency markets.\n\nOther places like the dollar because it is historically stable, and likely to stay that way for a while because it is backed by the most powerful country in the world, with the largest economy and the most fearsome army. If you bought German Deutschmarks in 1920, then a few years later your coin would have been worthless due to hyperinflation. Same goes for Italian Lira at several points in history, and many other currencies. To this day, there are countries around the world whose currencies are unreliable, so people don't like to keep their savings in those currencies because they might lose their value. For instance, the Cambodian Riel underwent a lot of inflation a few decades ago, and so the people there lost confidence in their currency, which is why nowadays the USD is the de facto currency for many transactions in Cambodia. It's a bit like putting your savings in gold, or some other good whose value you have confidence in, only more practical because dollars are already currency."
]
}
|
[] |
[] |
[
[],
[]
] |
|
2jl5wy
|
will wearing glasses daily deform your skull?
|
I've been wearing glasses for 10+ years and I've noticed indents where they sit on the side of my head. Is that an indent in the skull or just the tissue? Would they go away with the absence of glasses?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2jl5wy/eli5_will_wearing_glasses_daily_deform_your_skull/
|
{
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7,
3,
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"text": [
"Anecdotal evidence only: My wife, who is 46, has been wearing glasses since she was 4 or 5. There are indentations in the bone on the side of her head where the temples press.",
"How old are you? If your skull is still growing during your years of glasses use, your skull shape could easily have been influenced by your glasses. ",
"I don't have glasses but have an indent. Does this mean I will need glasses? ",
"It depends. If you were wearing glasses when you were younger (ages 0-10), there there might be some *slight* indents, but it's like foot-binding - unless there's a forceful binding for an extended period of time, you're not likely to see any deformation of your bone structure. \n\nIt works the same way that growing trees do. If you put something in the way of the natural growth that the organism can't overpower, it will grow around it.\n\nBones are strong, and humans move around a *lot*. \n\nThat being said, if you were wearing glasses for the past ten years, you've likely developed small callouses from where the arms of your glasses might have been rubbing behind your ears. I've been wearing glasses for over ten years, as well, and I have them. The more often you wear your glasses, the harder they will feel, and the deeper your callouses will run. \n\nIf you're especially concerned about them, see your doctor.",
"Can confirm, i don't use glasses and my skull is the same."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
dthuhm
|
how do contactless payments through a phone work without service or wifi?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/dthuhm/eli5_how_do_contactless_payments_through_a_phone/
|
{
"a_id": [
"f6wnsgi",
"f6wq6xv"
],
"score": [
11,
2
],
"text": [
"Your phone creates a \"virtual card\" of sorts. Your normal card is just a collection of data like serial numbers, account number etc that tells the card reader how to withdraw money. Your phone simply creates similar card, that effectively functions same way. Your card doesn't need internet access to work, and so neither does your phone (for this purpose).\n\nThe card reader does, however, require network connection - to actually contact the bank etc. Regardless of whether phone or card is used.",
"There are two main systems for phone payments. One is NFC (near-field communication). It uses a special chip in the phone that \"talks\" to the chip in the payment terminal. A virtual card is genereated, as others have said. NFC hardware must be in the phone, and it must be turned on in the OS and supported by an app - Apple Pay or Google Pay.\n\nThe other system is Samsung Pay, which \"fools\" a magnetic stripe card reader into \"thinking\" a card has been swiped through it. All the special hardware and software for this method is in the phone."
]
}
|
[] |
[] |
[
[],
[]
] |
||
4y83k9
|
how do home routers work and what do the various bands do?
|
I pay for decent internet service (90Mbps) but speed test maxes out at about 2MBps download speed. While I am not a wireless technician I know this is off and have heard talk of various bands that I can switch to or change. I have absolutely no idea how home networks in general function and how I might improve them so a basic overall explanation of that subject would be greatly appreciated
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4y83k9/eli5_how_do_home_routers_work_and_what_do_the/
|
{
"a_id": [
"d6lpo6e",
"d6ltywn"
],
"score": [
3,
2
],
"text": [
"Quite likely you are just being defrauded by your ISP provider, Just because you are paying for it does not mean you are getting it.\n\nYour download speed will be determined by your weakest link. Get a friend to come by with a laptop and check the download and do a ping test.\n\nIf you can hook up with a CAT 5 cable do that and check. That will eliminate any weakness due to your wireless router.\n\nBeyond that it is time to check with the ISP's technicians with your data.\n",
"Connect your computer via Ethernet and do a speed test. \n \n**Bands:** \n2.4GHz: Best penetrating power, maxes out at ~35Mbps. \n5GHz: Worse penetrating power, maxes out at 1.3Gbps I believe. \n \n**Generation:** \n802.11a: Dead slow, not sure anything uses this. \n802.11b: Slightly less dead slow, only Panera Bread uses this. \n802.11g: Decent speed, older devices use this. \n802.11n: Good speeds (max of 450Mbps I believe), uses both bands, but requires 5GHz for faster speeds, most all popular modern devices from the past 5-8 years support this. \n802.11ac: Best speeds currently (max of 1.3Gbps I believe), only uses 5GHz, most all popular devices from the past ~2 years support this. \n \n**Channels:** \nYour consumer American router for 2.4GHz can use channels 1-11, only use channels 1, 6, or 11, or you're an asshole. For 5GHz, set it to automatically select a channel. **If all your neighbors are using the same channel as you, that causes very slow speeds for everyone.** To find out what your neighbors use, you need a Wi-Fi scanner app, all Apple Macintosh computer's have them built-in, and Apple has it as an App Store app for iOS, Windows/Android will need 3^rd party apps. \n \nAlso, you said you were getting 2MBps download, which is 16Mbps, so I'm not sure if you meant that or 2Mbps."
]
}
|
[] |
[] |
[
[],
[]
] |
|
56gbek
|
If a huge and dense enough amount of coherent light was emitted, would it create a black hole traveling at the speed of light?
|
[deleted]
|
askscience
|
https://www.reddit.com/r/askscience/comments/56gbek/if_a_huge_and_dense_enough_amount_of_coherent/
|
{
"a_id": [
"d8j3gn4",
"d8je9nq"
],
"score": [
249,
9
],
"text": [
"A system of photons all moving in the same direction has no invariant mass, so you can Lorentz-transform into a frame where they have arbitrarily small energy. And in such a frame, it's clear that they should not form a black hole.\n\nAnd, a black hole has mass so it can never move at c.\n\nBut anyway, it's in principle possible to create a black hole purely out of light, you just need to make sure that it's not all moving in the same direction.\n\nIf you have two photons moving in opposite directions, this system has nonzero invariant mass. \n\nSo you can imagine an inwardly-moving spherical shell of photons all converging onto a single point. When the invariant mass of this system is within its Schwarzschild radius, in theory a black hole could form. This is called *kugelblitz*, but it's never been observed.",
"If it wasn't all traveling in one reference frame, instead gathering enough radiation together to create a black hole you get something called a [Kugelblitz](_URL_0_). Basically a black hole made of radiation that surpasses the Planck temperature; it's been theorized but never observed."
]
}
|
[] |
[] |
[
[],
[
"https://youtu.be/gNL1RN4eRR8"
]
] |
|
3phfq5
|
why do animals not seem to need the vitamins that humans do?
|
I get that their bodies are different and all but isn't our biological make up the same? My dog never eats oranges and doesn't have scurvy. Why can't I just eat meat and be good to go?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3phfq5/eli5_why_do_animals_not_seem_to_need_the_vitamins/
|
{
"a_id": [
"cw6apgr"
],
"score": [
2
],
"text": [
"First, you don't NEED a lot of vitamins. You benefit from their presence, but you can survive without them. \n\nBut for some of the ones you do need that animals don't seem to, it's because our bodies have evolved somewhat counterproductively to lose the ability to synthesize them ourselves. Back in the caveman days before there was such a thing as really long sea voyages, diet generally included teas and herbs and greens that had lots of vitamin C, so there was no scurvy.\n\nDogs eat meat and don't generally eat plants, so they didn't get much vitamin C and so kept the ability to synthesize their own."
]
}
|
[] |
[] |
[
[]
] |
|
2c64xj
|
why is aids poked fun at by comedians and shows like south park while diseases like cancer aren't?
|
Why is AIDS made fun of by crude comedians and tv shows while cancer isn't? Is cancer somehow more taboo than AIDS? Where did the laughability of AIDS come from?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2c64xj/eli5_why_is_aids_poked_fun_at_by_comedians_and/
|
{
"a_id": [
"cjcapcm",
"cjcat3j",
"cjcaubi",
"cjceadj"
],
"score": [
2,
3,
3,
2
],
"text": [
"According to the South Park episode, AIDS is declared officially funny. And dude comedians make fun of almost every disease. Except birth defects. That's just a comedy killer. ",
"If you tell a cancer joke to an audience, you better make it the funniest joke you've ever told, because it's likely that 75% of people in the audience have some personal relationship to a cancer victim, and a notable percentage have/had cancer themselves.\n\nThat makes it a pretty tough sell. You'd be better off telling a joke about airplane food.\n\nAIDS is a far more abstract and mysterious disease to most people. It's less commonly discussed, and therefore people have different sensibilities towards it.\n\nNow, that being said, AIDS is fairly off-limits as well, save for extremely off-the-wall comedy like South Park. I don't think you'll see many stand up comedians doing an AIDS set, knocking 'em dead with the AIDS puns (no pun intended).",
"You didn't see the episode about terrance and Phillip when they got cancer in their ass?",
"People make fun of AIDS because unlike Cancer you just cant \"happen to be unlucky and get it\", with AIDS, it is 99.9% of the time something YOU did to contract it via lifestyle choices.\n\nPeople make fun of others for doing dumb shit that puts them at a now disadvantage where as it is not commonly accepted to make fun of someone with Cancer because they did not have a choice in the matter.\n\n(excluding cigarette lung/mouth types that came from that).\n\nBut ladies with ovarian or males with prostate cancer just kinda get the short end of the stick. Making fun of that is generally frowned upon."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
6nvhh4
|
if most money is just numbers in a database, how come we don't hear of hackers who break in and just increase their account balance?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6nvhh4/eli5_if_most_money_is_just_numbers_in_a_database/
|
{
"a_id": [
"dkcieje"
],
"score": [
3
],
"text": [
"Accounting and balance sheets. Every debit has to have a credit, and every credit a debit...or it will show up as out of balance. If there were to be a balancing entry in the respective offset account, then maybe it would go undetected...but nonetheless it would still show up as an entry that someone is eventually responsible for reconciling. "
]
}
|
[] |
[] |
[
[]
] |
||
1apq4a
|
why news reports always use the word "allegedly" even if there is proof of something?
|
Basically, anytime you see a news story, they always state "The alleged thief was caught on camera and sentenced", or "The victim was allegedly stabbed to death". Why do they ALWAYS use this word? As far as I know, allegedly (alleged) can have many different meanings, however the very first meaning is *to assert without proof*, and yet another definition is *To declare with positiveness*. This seems contradictory. Anyone?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1apq4a/eli5why_news_reports_always_use_the_word/
|
{
"a_id": [
"c8zlkes",
"c8zm0g6"
],
"score": [
3,
2
],
"text": [
"Legally people are innocent until proven guilty. While they have arrested someone and charged them with say thievery, until the trial convicts them they are simply a \"suspect\" and not a thief. News agencies therefore cannot rightly declare them thieves just because they were charged with the offense and could rightly be sued for defamation, libel, slander, etc. They simply report that it is \"alleged\" that they were thieves which is accurate.",
"They can get sued for libel if it turns out they falsely accused someone, even if the evidence seemed impossibly good at the time. One time in a million, that proof that seemed so damning will turn out to be not so good after all. It costs the news agency nothing to pepper a broadcast with \"allegedly\", but it can save them tons if it prevents them from getting sued."
]
}
|
[] |
[] |
[
[],
[]
] |
|
37spm8
|
how do gift cards for multiple restaurants/stores work?
|
I understand they are all owned by the same corporation, but how does the money get spread out?
An example is Cara Operations in Canada, they own several restaurant chains such as Harvey;s, Swiss Chalet, Kelsey's, Milestones, and Montana's.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/37spm8/eli5_how_do_gift_cards_for_multiple/
|
{
"a_id": [
"crpj3yf"
],
"score": [
2
],
"text": [
"It gets split up when you purchase an item.\n\nWhen you purchase a gift card at Swiss Chalet, you're really purchasing fake-money only usable at Cara Operations' stores. I'm sure in Cara's accounting books they have a big bucket for all the giftcard money. Once it is used at Swiss Chalet goes out of the Cara account and into Swiss Chalet's account.\n\nBasically, you pay the umbrella company, and it sits there. When the gift card is actually used, the umbrella company pays the specific company (or division, whatever) you purchased items from.\n\nWhat happens to unspent gift cards? Probably depends on the company or laws, but most reduce their balance by $0.01 per day after like 3 years of non-use (assumed lost or thrown away). How is that split up? Could be evenly among the companies, could all go back to the company where the gift card was originally purchased."
]
}
|
[] |
[] |
[
[]
] |
|
5jgmyf
|
why do black americans seem to be affected by slavery more so than people of other ethnicities are affected by the generational atrocities committed against their people?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5jgmyf/eli5_why_do_black_americans_seem_to_be_affected/
|
{
"a_id": [
"dbg0c9h",
"dbg0iox",
"dbg0r2m",
"dbg0sun",
"dbg2uxi",
"dbg3dwl"
],
"score": [
5,
3,
14,
8,
4,
21
],
"text": [
"They aren't. Plenty of people around the world have it worse than African Americans. There are even places in the world that still practice slavery today.\n\nAfrican Americans, however, are American. Because of that, they are near to the world's centers of culture and entertainment. They are also the most numerous minority in America. So while oppressed people everywhere struggle to overcome adversity, you are substantially more likely to hear about efforts from African Americans.\n\nA good number of liberal movements exist to try to raise awareness of other, less famous groups who also need change to achieve equality. I'd encourage you to become more involved with any that you feel you can.",
"First, I'll admit, I'm not sure how to answer your question because it's hard to quantify and compare. \n\nOne distinction that there is between the experience of blacks in America and many other ethnic struggles is that the African American population was effectively created out of whole cloth from slavery, and the legacy of slavery in terms of ethnic strife and government empowered racial division lasted well into the 20th century (and some would argue still lingers, to some degree). \n\nThere were Jews before the Holocaust, Irishmen before the famine, Han Chinese before the century of humiliation, but African Americans are even more synthetic a population than Americans writ large. Maybe the native peoples of the Americas are comparable, but they are still pretty effected by colonization too. ",
"Black people are more impacted because it lasted longer. Slavery lasted a long time in America, and even once that was over, sharecropping and prison labor took its place. I don't want to get too much into racial politics, but at the time black Americans were still trying to get on their feet, whiteness was readdressed to include the Irish and Italian immigrants, who essentially were united with white people by harming/hating black people. That, combined with housing discrimination, job discrimination, and other prevalent institutional racism means that black people have had a harder time trying to bridge the income gap. ",
"Slavery as well as racist oppression didnt end until very recently. slavery \"officially\" ended 150 years ago, with segregation remaining legal for the next 100 years. Legally a black man could not marry a white woman (or vise versa) until the late 60s. Tl;DR this isnt a old wound.\n\nAlso there are a lot of ethnicity that are bitter about their history. Jewish people still have emotional responsive to WW2 stories, and i am sure the same goes for the Armenian people. just to name a couple.",
"IMO, one of the main factors is that there haven't been any real reparations paid for their suffering. Their ancestors played a significant role in literally building this nation and they have no generational wealth to show for it. African Americans have only started to see equal *opportunities* in the last half-century or so. Yet, they still hold a disproportionately small percentage of the total wealth because they never had that family home, business, or inheritance that could be passed down from generation to generation. Essentially, they started with a handicap (slavery, inability to vote or own property, etc.) and it was never remedied. Thus, they are still affected by it. \n\nFor instance, Jews were paid reparations by the Germans for the Holocaust and I would imagine claims are still being made to this day. In America, there have been billions of dollars in reparations paid to Japanese Americans as a result of the internment camps of WWII. Yet, the descendants of slaves have yet to see a nickel. Of course, it's a complicated issue and reparations are only a small part of it, but I think it would help ease the tension.",
"The real answer is that wasn't just slavery. There was overt institutional oppression of blacks until very recently. When you're talking about, for example, Jim Crow laws that were in place until the mid 60s, they affected people who are now as young as in their 50s. That means people in their 20s might have parents that were in segregated schools for part of their schooling, or a grandparent that had to use a Green Book when driving long distances to know where they could eat or sleep.\n\nThere are also lots of other ways black Americans were purposely disenfranchised in the last 50 years, but I'm a fairly uninformed Canadian. If you're truly interested in some of the reasons why black people still care about slavery, and you're not just making a thinly veiled racist shitpost, you should do some research into the last 100 years of African American history."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[]
] |
|
7tljfp
|
What the heck is with Switzerland? How have they avoided almost every single major European war or conflict for the past 600 years or so? Is it due to their geographical location, their banks, or a third factor?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7tljfp/what_the_heck_is_with_switzerland_how_have_they/
|
{
"a_id": [
"dtdjint"
],
"score": [
32
],
"text": [
"First to just clarify, Switzerland has participated in some large conflicts during the last 600 years, most recently the Napoleonic wars, though they have been neutral since. I will mostly touch on the world wars but most of the points apply to almost any period since 1880. \n\nSwitzerland as a country is located high within the alps, which is a very difficult to navigate area. The mountains are treacherous, and has many small narrow passages that would remove any numerical advantage an enemy would have. Add to this that these passages were heavily fortified with bunkers and defence positions.\n\nOn top of the previous point, Switzerland has a very large military force relative to it's population. With mandatory military service a large part of the population are training in combat and the government would have been able to mobilize a large part of it's population. At the height of mobilization the Swiss army had over 850,000 soldiers mobilized. These soldiers would have had the homefield advantage, knowing the terrain and being used to the conditions of the mountains.\n\nThe main idea was to make it as costly as possible for any other country to try and invade. The main benefit that holding Switzerland could provide was an easy passage from central Europe to southern Europe, and the swiss knew this. The main strategy if war had broken out were to retreat to the bunkers along the mountain passes and defend from there, if the army would have lost they would have blown up the tunnels effectively making the country impassable, rendering any advantage victory would have given useless. This strategy was called the réduit.\n\nThe swiss were also neutral, and were no threat to other countries surrounding them. There was no need for anybody to be afraid that Switzerland was suddenly going to invade, so the germans, italians, french and austrians were happy enough to let Switzerland act as a natural bufferzone between their empires. "
]
}
|
[] |
[] |
[
[]
] |
||
6kaxzf
|
why is the death rate for alzheimer's so incredibly low in japan?
|
In Canada, the death rate per 100,000 for Azlheimer's is 35.50. In France, it's 25.62. In the US, it's 45.58. In Japan, on the other hand, the death rate is staggeringly low at 4.23.
Logically, one would expect Japan to have an even higher death rate from Alzheimer's than most countries given that Alzheimer's affects old people and Japan has the second highest life expectancy in the world. Why is it then that deaths from Alzheimer's are so few and far between in Japan?
Source: _URL_0_
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6kaxzf/eli5_why_is_the_death_rate_for_alzheimers_so/
|
{
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"djkn01w",
"djko1by",
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"djl2s5p",
"djl5gtg"
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3,
3,
19,
2,
2
],
"text": [
"I could imagine diet and life style play a part. From what I understand people in Japan eat a very healthy diet with very little processed foods. This general means they reach old age with a less diseased and ailments compared to America and Canada. ",
"Alzheimer's is a tricky thing. Although it comprises a hefty chunk of modern day research, our attempts at narrowing its underlying causes is progressing but is in no way resolute at this time. However, it seems there are some clear genetic predispositions. Japan may ultimately comprise of a population of human beings lucky enough not to carry a high number of mutations that potentially lead to the development of Alzheimer's. Another reasoning could be diet and health. ",
"This is all supposition on my part, but here it goes...\n\n- Society. Asian cultures are far more likely to have younger generations care for their elders. As such, they spend a lot less time isolated and maintain active participation in everyday life. Maintaining this level of brain activity and socialization can only be a good thing.\n\n- Genetics. Japan is isolated and the genetic precursors for the disease seem to be much more common in people of Caucasian origin.\n\n- Diet. The Japanese eat an absolute shitton of fish and other foods high in omega-3's and other brain friendly organic compounds. If there were any way to stave of the disease with diet, it would be to eat like a Japanese person.\n\n- Culture. The Japanese do shit until they literally can't do it anymore. They are far more likely to maintain active lifestyles well into old age than just about all Western populations. There is a link between sedentary behavior and dementia and the Japanese (in general) do a pretty good job of staying active throughout their life. ",
"The fact that red meat and dairy consumption are drastically lower in Japan perhaps has something to do with it.",
"It just means Japanese physicians mark other things on the death certificate more often. Like \"death from sepsis secondary to aspiration pneumonia\" (caused by late stage Alzheimer's). This is a reporting issue. It's not as though their Alzheimer's is 10% as bad as Finland's, or 200x as many people in the US die from Alzheimers dementia compared to Uzbekistan. This is simply differences in reporting. "
]
}
|
[] |
[
"http://www.worldlifeexpectancy.com/cause-of-death/alzheimers-dementia/by-country/"
] |
[
[],
[],
[],
[],
[]
] |
|
yvh0f
|
What would a nuclear detonation on the surface of the Earth look like from the ISS or similar orbiting platform?
|
Assuming the bomb is something in the range of 20 to 50 Megatonnes
|
askscience
|
http://www.reddit.com/r/askscience/comments/yvh0f/what_would_a_nuclear_detonation_on_the_surface_of/
|
{
"a_id": [
"c5z7fxb"
],
"score": [
8
],
"text": [
"Okay. The ISS orbits between 200 and 250 miles high. A 20 megaton bomb will produce a fireball [about 2 miles in diameter](_URL_1_). It will cause a \"conflagration\" [40 miles in diameter](_URL_0_).\n\nWhat would this look like from 200 miles away? Here's a place to start: imagine driving down the interstate and passing a \"1 mile to exit\" sign. What does the exit sign look like at that distance? You can definitely see it, you can't read it, but you can tell it's there. You could make out its shape. If it was lit up, you would sure as hell notice it then. An interstate exit sign is probably 15 feet high. 15 feet at 1 mile distance is 3000 feet at 200 miles distance. So *just the fireball* produced by the explosion would be 3 times the apparent size of the sign that we're talking about. The destruction would extend for another 20 times that distance. I think that would be pretty noticeable.\n\n[Here's a picture taken from the ISS.](_URL_2_) If you look at Christchurch, NZ in Gmaps you can see where this is. View the picture full size and find the river that makes a downward-facing number 3 (it's at 10 o'clock from the astronaut whose face you can see). That number 3 is about 10-12 miles high. I think the picture was taken with a relatively short lens (look how much perspective you can see in the parallel lines of the space station).\n\nConclusion: you can see lots of stuff from 200 miles away. Nuclear explosions are big. "
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Effects_of_nuclear_explosions",
"http://en.wikipedia.org/wiki/File:Comparative_nuclear_fireball_sizes.svg",
"http://i.imgur.com/sZUCu.jpg"
]
] |
|
7hhfhs
|
Why don't microorganisms die from cold temperatures?
|
I know they can die from very high heat and are only inactive in cold temperature (not dead). I mean humans can't thrive in cold climate without any really thick clothing. How do microorganism not die from cold temperatures?
|
askscience
|
https://www.reddit.com/r/askscience/comments/7hhfhs/why_dont_microorganisms_die_from_cold_temperatures/
|
{
"a_id": [
"dqscbbw"
],
"score": [
2
],
"text": [
"Microorganisms have adapted to a range of extreme environments, including extreme cold. Every microorganism will have an ideal temperature range for growth and a temperature range at which they survive, and most microorganisms cannot grow at low/near-freezing temperatures.\n\nMicroorganisms that can are called psychrophiles. The cells in these microorganisms do not freeze but undergo desiccation and a glass transition that does not cause death. This process also results in a slowing of metabolic activity, which can then resume when the temperature rises. These psychrophiles often have additional adaptations that facilitate metabolism at cold temperatures or protect vital cell parts from freezing.\n\nHumans on the other hand don't have the ability to reduce metabolism to near zero while still maintaining life. In hypothermic conditions, the cellular metabolism does start to shut down, which in humans results in a drop in heart rate and respiration usually. This leads to organ failure and death, as the components of the human body can't keep functioning without blood flow through to provide energy and take away wastes."
]
}
|
[] |
[] |
[
[]
] |
|
9eptip
|
how a country like venezuela in such financial and institutional chaos can ever recover.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9eptip/eli5_how_a_country_like_venezuela_in_such/
|
{
"a_id": [
"e5qlebh",
"e5qmgu8"
],
"score": [
6,
4
],
"text": [
"Define \"recover\". The government may be deposed violently, a bunch of people may starve or flee the country, but they aren't entirely without resources so a smaller population could be supported. Alternatively the current government may see the opposition coming and institute a civil war / purge to reduce the population to a smaller, loyal base. After the death squads clear out the areas that oppose the current regime there are fewer people to support and it can be blamed on treason and foreign influence rather than mismanagement.",
"It's hard to say, but historically countries that have encountered levels this high of economic instability decided to undergo a process called currency substitution (often referred to as dollarization). Basically countries remove their native currencies from circulation and replace them with a historically stable currency, like the US dollar or euro. This is good because these currencies are in very high circulation and have very structured control, so it is far more difficult to instigate large inflation from mismanagement. The bad side is the countries are at the mercy of the US or EU monetary policies, which don't really care about Zimbabwe's or El Salvador's economic needs. Venezuela is special because it has tremendous amounts of wealth, mostly in the form of oil. This makes it more attractive to lenders. It can issue super high yield bonds, backed by oil, and generate emergency cash that way. This is, by the way, not sustainable, as you can promise oil to as many people as you want, but you can only deliver it once. If Venezuela defaults on several loans, it will lose its cash, and its oil. "
]
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[],
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1plsbz
|
If I go headlong toward a black hole, accelerating to near the speed of light, will time dilate so I never actually get there?
|
The faster you go, according to relativity, the more time slows down. If I travel directly toward a black hole, accelerating as fast as I can, will I ever get there? Will time dilate so that it will just slow down and leave me hanging on the precipice? What will happen?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1plsbz/if_i_go_headlong_toward_a_black_hole_accelerating/
|
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" > The faster you go, according to relativity, the more time slows down.\n\nThis is what other people, who aren't moving with you, see happen to your clock. You, on the other hand, experience time passing perfectly normal while observing those other clocks to be running slow.\n\n > If I travel directly toward a black hole, accelerating as fast as I can, will I ever get there?\n\nAccording to the general theory of relativity^([*]), yes; you will reach the event horizon in finite time, cross it, and be destroyed by tidal forces (though not necessarily in that order). However, that's not necessarily what someone far from the black hole would *see*. To such a person, you would appear to get compressed up against the event horizon. As this happened, you would get redder and redder until you left the visible spectrum. Even if they could detect infrared signals, though, you they *would* eventually see you disappear.\n\nAs I said, you cross the event horizon in finite time in your reference frame. Because light is quantized, this means you will emit a finite (though large) number of photons before crossing the event horizon. Our immortal distant observer will receive that photon a finite (though very large) time after you fell toward the hole, after which time the only indication that you ever existed will be a slight increase in the apparent surface area of the black hole.\n\nThe important thing is this: time dilation is always something that is observed either by outside observers or by moving two clocks apart and then bringing them back together. You always experience time at a rate of one second per second.\n\n[\\*] This is the result from the general theory of relativity, which is a classical theory. I have not, for example, accounted for any quantum effects (beyond the quantization of light) that might be encountered near, at, or inside of the horizon. Theoretical research in this area is ongoing, but in the absence of any *actual* black holes to study we're basically stuck checking for consistency between models. There are some strong constraints on these models, but to date no model for describing such interactions has yet come out as a clear \"winner\".",
"The way it was explained to me in college was that a person observing from the outside would see you slow down as you got closer to the event horizon in the black hole and eventually you would appear to stop. From your perspective looking out, time outside the black hole would appear to get faster and faster. But, for both of you, your own time would seem to move at the same pace it always has."
]
}
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[],
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6rf2ks
|
In the USA before soft drinks were invented, what were the recreational drink of choice for non-alcohol drinkers?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/6rf2ks/in_the_usa_before_soft_drinks_were_invented_what/
|
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"Hi there people!\n\nThis thread is rising currently on the sub and so I am here to remind people that we have [rules for answers](_URL_4_) in place. Answers should be:\n\n* in-depth, comprehensive, and informative\n\n* should be based upon historical scholarship, which preferably should be cited\n\n* and not consist solely of a joke (I mean seriously, jokes at the expense of alcoholics? Really classy, people...)\n\nPlease adhere to our rules when commenting.\n\nAlso, good answers need time to be research and written and while we understand the frustration at waiting for one, in the meantime you can check out the great content that is produced on this sub everday at places like [Twitter](_URL_0_), the [Sunday Digest](_URL_2_), the [Monthly \"Best Of\"](_URL_1_) feature, and now, [Facebook](_URL_3_).\n\nThank you for your patience.",
"A few follow up questions.\n\n[Benjamin Franklin writing to John Lining on 17 June 1758](_URL_2_) refers to a \"a kind of hot punch, made with water, mixed with honey, and a considerable proportion of vinegar.\"\n\n[George Washington wrote in his diary on the 15th of February 1760](_URL_0_)\n\"Went to a Ball at Alexandria—where Musick and Dancing was the chief Entertainment. However in a convenient Room detachd for the purpose abounded great plenty of Bread and Butter, some Biscuets with Tea, & Coffee which the Drinkers of coud not Distinguish from Hot water sweetned.\"\n\n[John Adams wrote in his diary on the 22 December 1779](_URL_1_) \"Drank Tea at Senior Lagoaneres. Saw the Ladies drink Chocolate in the Spanish Fashion. A Servant brought in a Salver, with a number of Tumblers of clean clear Glass full of cold Water, and a Plate of Cakes, which were light Pieces of Sugar. Each Lady took a Tumbler of Water and a piece of Sugar, dipped the Sugar in the Tumbler of Water, eat the one and drank the other. The Servant then brought in another Salver of Cups of hot Chocolate. Each Lady took a Cup and drank it, and then Cakes and Bread and Butter were served. At last Each Lady took another Cup of cold Water and here ended the repast.\"\n\n1. Was water sweetened with honey or sugar a common thing to have?\n\n2. Where is coffee coming from during this period?\n\n3. Was drinking \"Chocolate in the Spanish Fashion\" popular? Adams' description makes it sound as if it were uncommon.\n\n",
"As you hinted at, early America's drinks of choice were ale/porter/beer, cider, wine, brandy, rum, and whiskey. But other non-alcoholic drinks were readily available. They had to be. One of America's early sizable communities were the Quakers, who were teetotalers.\n\nAll the links below link back to the letters, receipts, and publications of various Founding Fathers/Mothers in the late 18th Century, including Benjamin Franklin, Thomas Jefferson, George Washington, James Madison, John Adams, and Abigail Adams, describing their non-alcoholic beverage habits.\n\nOn the occasion when people weren't drinking alcohol, then the drinks of choice were tea ([1](_URL_6_), [2](_URL_16_), [3](_URL_14_)), coffee ([1](_URL_1_), [2](_URL_4_), [3](_URL_24_)), water ([1](_URL_13_), [2](_URL_21_), [3](_URL_9_)), and milk ([1](_URL_11_), [2](_URL_22_), [3](_URL_17_)). (You'll need to CTRL+F the beverage in question to see the relevant section of those Founding Fathers' papers.)\n\nOf those four non-alcoholic beverages, milk was probably the least frequently consumed by adults, but it nonetheless was. John Adams even went on a [milk and bread diet](_URL_22_) at one point. Tea consumption was widespread, as evident by the famous \"Boston Tea Party\". Less well remembered are the protests in other port cities against the Tea Act. It's been estimated that about [6.5 million pounds of tea](_URL_10_) were being imported to the Thirteen Colonies annually by the time of the Revolution. This out of a population of 2.5 million people means that, if a pound of tea yields 200 cups, then, on average, an American was drinking 520 cups of tea per year.\n\nHistorians from the colonial period may also be familiar with the Founders' love of coffee. Coffee-houses were ubiquitous in America's largest cities, including Boston, New York, and Philadelphia. They were often used as meeting places for politicians and other prominent men. Probably the most famous coffee house of colonial America was New York's Tontine Coffee-House, which was at the corner of Wall Street and Water Street in downtown Manhattan. It was frequented by traders, merchants, and brokers, a group of whom signed a document in 1792 called the Buttonwood Agreement that was the genesis of the New York Stock Exchange.\n\nA good example of what the Founders were consuming can be seen in Thomas Jefferson's [Memorandum Books of 1776](\n_URL_5_) which listed a lot of his expenses. Among the items are two purchases of tea, three purchases of milk, and a purchase of coffee and a \"coffee mill\". \n\nSimilar is the record of the estate of of Daniel Parke Custis, who died in 1756-57. Among the [\"slaves and personal property\"](_URL_7_) he left behind were tea pots, tea kettles, tea chests, coffee pots, milk pots, and water pots.\n\nOther than that, other non-alcoholic drinks available to the colonists would have been lemonade and possibly limeade (limes were bought in [juice form](_URL_15_) anyway), though probably not as frequently consumed by adults as alcohol, tea, coffee, and water. Lemons and limes were two fruits that were regularly available in the Thirteen Colonies, direct from the Caribbean colonies. These fruits appeared in many different [alcoholic drinks](_URL_23_) of the time, and also in its non-alcoholic lemonade form. The drink appears in Thomas Jefferson's memorandum books of both [1785](_URL_8_) and [1786](_URL_18_), and Abigail Adams [wrote about](_URL_19_) lemonade as well. \n\nIn the same sentence in the same letter, Adams also [wrote about](_URL_19_) a more forgotten beverage that she spelled \"orgee\". This was probably \"orgeat\", a \"cold beverage made of barley, almonds, or orange-flower water\" according to the Oxford English Dictionary.\n\nAside from that, there are also references to cocoa and vegetable juices in the papers of the Founding Fathers. There were probably some non-alcoholic apple, pear, and cherry ciders produced as well, particularly among the Quakers in Pennsylvania, New York, and New Jersey.\n\nIn short, the Founding Fathers essentially drank all the same stuff we do today, except for fizzy soft drinks and artificially flavored drinks that came in the 19th Century and after. They didn't have access to all the varieties of fruit juices that we have today, but they did have access to some, and tea, coffee, milk, water, and lemonade, as well as various alcoholic beverages, would have been familiar to Americans at the time the country was founded.\n\nAfter the late 1700s, I am sure other beverages arose in the U.S. before carbonated soft drinks came around. Maybe somebody else can add more info about that period.\n\nFURTHER READING:\n\n\"History of Coffee In Old New York\", [*All About Coffee*](_URL_2_) by William Harrison Ukers, 1922\n\n[*Tea Drinking in 18th Century America: Its Etiquette and Equipage*](_URL_0_) by Rodris Roth, 1961\n\n[*Food and Drink In America: A History*](_URL_12_) by Richard James Hooker, 1981\n\n[*Abigail Adams: An American Heroine*](_URL_3_) by John P. Kaminski, 2007\n\n[*John Adams: A Life*](_URL_20_) by John Ferling, 2010\n\n\n"
]
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"https://founders.archives.gov/?q=punch&s=1111311113&sa=&r=20&sr="
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"https://archive.org/details/cbarchive_104823_teadrinkingin18thcenturyameric1877",
"http://founders.archives.gov/documents/Franklin/01-01-02-0118",
"https://books.google.com/books?id=4O_RAAAAMAAJ&dq=tontine%20coffee-house&pg=PA115#v=onepage&q&f=false",
"https://books.google.com/books?id=Q0WQjS0UuRYC&pg=PA106&dq=lemonade",
"http://founders.archives.gov/documents/Madison/01-03-02-0105",
"http://founders.archives.gov/documents/Jefferson/02-01-02-0010",
"http://founders.archives.gov/documents/Franklin/01-01-02-0082",
"https://founders.archives.gov/documents/Washington/02-06-02-0164-0006",
"http://founders.archives.gov/documents/Jefferson/02-01-02-0019",
"http://founders.archives.gov/documents/Adams/06-03-02-0007",
"https://books.google.com/books?id=x10_AQAAMAAJ&pg=PA249&dq=tea",
"http://founders.archives.gov/documents/Franklin/01-04-02-0027",
"https://books.google.com/books?id=efuBAAAAMAAJ",
"http://founders.archives.gov/documents/Franklin/01-01-02-0107",
"http://founders.archives.gov/documents/Adams/04-05-02-0242",
"http://founders.archives.gov/documents/Franklin/01-02-02-0052",
"http://founders.archives.gov/documents/Washington/01-01-02-0002-0006-0001",
"http://founders.archives.gov/documents/Franklin/01-13-02-0192",
"http://founders.archives.gov/documents/Jefferson/02-01-02-0020",
"http://founders.archives.gov/documents/Adams/04-07-02-0037",
"https://books.google.com/books?id=0ppoAgAAQBAJ&pg=PA33",
"http://founders.archives.gov/documents/Washington/01-01-02-0003-0002",
"http://founders.archives.gov/documents/Adams/01-03-02-0016-0005",
"http://founders.archives.gov/documents/Franklin/01-10-02-0188",
"http://founders.archives.gov/documents/Adams/04-02-02-0235"
]
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3a3wx4
|
In the study of epigenetics, how do we know a given gene is being expressed?
|
What techniques are used in the field? Would a DNA sample reveal the epigenome or is more information necessary?
|
askscience
|
http://www.reddit.com/r/askscience/comments/3a3wx4/in_the_study_of_epigenetics_how_do_we_know_a/
|
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"Epigenetic regulations can occur on the DNA of a cell. DNA is packed in proteins (histones), and on these histones epigenetic regulations also occur. A well-known epigenetic marker on DNA is DNA-methylation. DNA-methylation usually silences a gene. A well-known epigenetic marker on histones is acetylation, this usually makes a gene more active. By chemical analysis this epigenetic code on the DNA can be deciphered.\n\nThere are also epigenetic regulations that do not occur on the DNA. These include sRNA , that bind to mRNA and can silence the transcription into proteins. So from analyzing DNA alone, it is impossible to know the exact epigenome, but it says a lot. For example, in development, deciding whether a cell becomes a neuronal cell or let us say a muscle cell, depends largely on DNA/Histone regulations. \n\nTo analyze gene expression in general, researchers often use a RNA-microarray. This gives an estimate of how much of the DNA is being translated into mRNA, and therefore says something about the gene expression.\n\nI tried to keep this as short and simple as possible, so I assumed that you already have some knowledge about this. If anything is unclear, just ask.",
"As AnIntoxicatedRodent says, epigenetic modifications are changes to the chemical structure of DNA (although they do not change the actual sequence of bases, the letters, of a DNA strand) or to the chemical structure of the protein complexes (histones) that DNA is wound around when it is packaged up inside the nucleus. Researchers have several ways of looking for these modifications. For example, they can use antibodies that stick to specific DNA or histone modifications, and then sequence the DNA fragments that the antibodies have bound to. To look at a specific type of epigenetic modification, methylation of DNA, researchers can use a chemical treatment that converts the modified DNA nucleotide to a nucleotide found in RNA, that will show up differently when the DNA is sequenced and show that that location on the DNA strand was modified.\n\nHowever, we still know too little about epigenetic modifications and how they affect gene regulation to just look at how a stretch of DNA with a gene in it has been modified, and know from that how the gene's expression will be affected. Researchers do use microarrays to measure the expression of many different genes simultaneously. However, as DNA sequencing has gotten cheaper, faster, and easier, more researchers are now using \"RNAseq\", where the mRNA or other types of RNA in a cell are directly sequenced, as a way to measure gene expression. Quantitative PCR is also used to very accurately measure the expression of one gene at a time.\n\nLooking at gene expression data and epigenetic modification data from the same cells or tissues, and exploring how those two things are related, is how researchers are continuing to learn more about how epigenetics works--how it helps control gene expression.",
"It depends what you mean by \"expressed\". Also the following techniques have nothing specifically to do with epigenetics, they're just how you can see if a given gene is being expressed:\n\nIf you mean \"currently being transcribed\" then you can do a [nuclear run-on assay](_URL_3_). Most other techniques (northern blot, PCR, microarray, RNA-seq) simply detect the presence of RNA, but since mRNA median half life is [about 7 hours](_URL_0_) the RNA may have been transcribed hours ago. However, PCR, RNA-seq, etc. are often used as a stand-in to test for gene-expression and most of the time they're good enough.\n\nIf you mean \"is making a functional product\" then usually you'll want to look for a protein (eg. with a western blot), but like with the RNA, because proteins can hang around a long time, just because a protein is present doesn't mean the gene is *currently* being expressed.\n\nEpigenetically, you can infer that a gene is being expressed based on certain epigenetic marks but it's not as definite as the above techniques: lack of DNA methylation in the promoter, presence of H3K4me3 and H3Ac/H4Ac in the promoter, lack of H3K9me3 and H3K27me3 anywhere in the gene, and probably the best one is the presence of H3K36me3 in the gene body. [Histone code](_URL_2_).\n\n > Would a DNA sample reveal the epigenome or is more information necessary?\n\nTo study DNA methylation you need genomic DNA, to study histone modifications you need [chromatin](_URL_1_)."
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"https://en.wikipedia.org/wiki/Nuclear_run-on"
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97qtij
|
why haven't we invented a better way to clean teeth than brushing/flossing?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/97qtij/eli5_why_havent_we_invented_a_better_way_to_clean/
|
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"A few reasons contribute to why a new method of cleaning teeth is not out.\n\n1. The need for a new method to clean teeth is almost non-existent. Brush, floss and go to the dentist every 6 months can guarantee healthy teeth in the long run. \n\n2. Products like toothbrush and toothpaste are cheap for the regular joe. Customers are satisfied.\n\n3. It's only a minor hassle that people have accepted. If it is a hassle that is big enough, the demand for a new cleaning method will rise and it might be on the market really soon. But as of now, the demand for a new method is low. \n\n4. Yes, it is true that we need a water source. To satisfy the need for a water source, we have invented plumbing. The majority of the human population aren't nomads, just one good water system and we're good to go. \n\n5. The hair on a stick and the durable string tools is simply good enough to do 95% of the job. The other 5% is done by dentists every 6 months. Why must we invent another tool or method simply because its predecessor is ancient? \n\nHere are more tools that are way older than your great grandmother. Paper, ink, pencil, fork, spoon, knife and the list goes on and on. If you use my argument to say \"then why the fuck did we invent the computer that replaces the calendar, dvd player, newspapers etc?\" Here is my answer. It is easy enough to program a computer to do the job. Perhaps in the future there exists a full body cleansing machine which will replace the floss and the toothbrush.",
"3rd year dental student here. Got any more specific questions?",
"I don't know the specifics, but it's more that simple sugars in our diet are far more accessible today than well, say, 500 years ago. Since the general flow is sugars + existing bacteria in mouth - > acid - > tooth decay, not having access to much sugar just causes tooth decay to be a less critical issue. \n\nDentures have also been available for centuries, and I'm assuming the rest of the folks that couldn't afford them would just suck it up.",
"Related question: \n \nIs there a \"point of no return\" for dental care vs damage vs teeth on a daily basis? I brush my teeth and floss twice a day, sometimes a third (morning and evening always). However... drinking 1-2 energy drinks a day and I still get holes in my teeth. It is as if there is a point where, enough sugar will damage your teeth regardless of how much you care for them. As if it doesen't even matter if you cross a certain treshhold.",
"We haven't really come up with a better alternative to water and a brush for any sort of cleaning at all. It's an intrinsically mechanical (as opposed to chemical) process so you need mechanical solutions.",
"It doesn’t help that the ADA are against major developments that could keep you away from your dentist longer. \n\nFor instance, they are against the use of NovaMin and BioMin which are two amazing products that help your teeth regenerate tooth enamel. You can’t get it in the US. \n\nHowever, it’s available in basically any other country. I import mine from India. \n\nLike a lot of the industry/regulatory groups in the US, they basically represent the professionals and look out for their best interests. \n\nI’m sure there are other dental technologies that have been killed off. ",
"Brushing and flossing IS very effective. However many people do both of these things very incorrectly. When brushing, you are not scrubbing back and forth, you are moving rapidly in concentric circles along the gums to disorganize plaque. An electric toothbrush really does this best.\n\nFlossing is not to clean in between teeth, but rather to clean in between the tooth and the gumline. So you are flossing twice between each tooth, once along each \"tooth wall\". In helps to think of the floss as making a \"C\" shape as you go.",
"There are these kind of tiny things that have a tiny tooth sized bit of floss in them, the end of it also doubles as a toothpick. Sadly they were disposable.\n\n If I could get some sort of more durable version of the floss on stick thing it would be nice",
"My dentist told me floss companies told the dentist community to not let the patients know they can replace floss with listerine because they were afraid the floss business would perish. She asked me when was the last time I flossed and I said when you flossed them 6 months ago and she said hm they look super clean for not being flossed for six months and I old her I constantly use listerine and that’s when she said that",
"We have apparently. There is a company in austria that offers sort of an alternative brush that only needs like 10 or 20 seconds to clean your teeth. But i dont know if it includes flossing or not.",
"There needs to be some type of mold that fits your mouth that has strings that go in between your teeth. The outer part of the mold will have bristles similar to a regular tooth brush and the strings that fit in between each tooth act as floss. The device will vibrate to clean your teeth like how an electric toothbrush does. Toothpaste would be added to the device and distributed evenly to all teeth throughout the automatic brushing process.",
"So so sadly always about money. If everyone had easy and cheap access to tools that keep you from ever having problems from your teeth then we would have no need for dentists aside from the needs of people with hereditary dental problems. Soooo pretty much the extent of research done on mouth cleaning technology is \"how can we market a new toothpaste better than we already do?\" ",
"I see some good responses here, but the primary reason we haven't found a better way to clean teeth is because of the naturally complex shape of our mouths, which makes it difficult to remove any bacteria, tartar, plaque, etc. There are so many things going in your mouth and many tiny pockets where bad bacteria can grow such that cleaning your mouth completely is nearly impossible. Food particles can get stuck in your gums, hidden between teeth, tooth cavities, under your tongue, under the inside lips, and the list goes on. Even the best tooth brushes out there won't clean out all the bacteria and food particles sitting in the tiniest of spaces. This is why dental cleaning is so important and is recommended every 6 months. You need a professional to look at your teeth to determine if you've been following proper dental hygiene. Thanks to biology, our mouths have accustomed to allowing bacteria to grow inside without necessarily harming us. Now, you can argue that you want better designed toothbrushes or dental technology to clean teeth much more quickly, but just like everything it comes at a cost that no average person would spend at the grocery store. ",
"In Muslim countries we frequently use the [Miswak](_URL_0_). \n\nIt's been around for thousands of years, but was massively popularized by Islamic teachings. It requires no water source, and can be used at any time throughout the day.\n[Wiki](_URL_1_)",
"Brushing and flossing honestly don't take up a lot of time. If you're brushing correctly, it should take about two minutes. Flossing takes only 1-2 minutes. Brushing twice a day & flossing once per day will only take a grand total of 5-6 minutes out of your day. Don't be lazy."
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1wqnv4
|
When/Why did it stop being acceptable for Western aristocrats/noblemen to take mistresses? How was this practice reconciled with Christian doctrine forbidding adultery?
|
My first question is whether I am indeed correct in my understanding that the practice of both taking mistresses/concubines by noblemen was both widespread and acceptable. By acceptable, I mean the sort of thing for which there was no, even theoretical, objections most people would raise (jealously from a man's wife being some else entirely), and for which the person engaging in it would feel no need to conceal it, or that the practice would cause any sense of scandal. By comparison, I know that, at the very least, it was not unheard for clergymen to have mistresses, but as far as I know, catholic doctrine is rather clear on requiring the ordained to be celibate, and of course monks and nuns took vows of celibacy. Even if there were instances of clergy engaging in this practice as a sort of open secret, it was still objectively a violation of the "rules," as it were (at least after whenever it was that the church began to require priests to be celibate). If I am incorrect here, please correct me.
In any case, clearly the social mores have changed. If, for example, Prince William were found to have a mistress, this would be a huge scandal. I guess my question is what caused this shift in our understanding, in the west, of what marriage entails, in terms of what it means to commit adultery or to be unfaithful? Was this practice of sanctioned extramarital affairs something which included all men? Was it merely the noble? The rich? Was there a continuum? If I were, for example, to go back in time and accuse some monarch of committing adultery for having a mistress, how would he respond (besides, you know, executing me)? Would this claim even make sense to him? Now obviously, just because someone is Christian does not mean he or she is going to perfectly adhere to all the precepts of their faith. Obviously, there are many instances of noblemen engaging in unchristian activities. However, what has always confused me about the practice of them having concubines is that contemporary writers do not seem to decry it as sinful as they might for other activities. What I mean is that it does not seem to have been (generally speaking) something which was viewed as a moral failing, or something which was notable or unusual enough to make any more than passing reference to. In the same way, if I were to write some polemic about someone today, it would never occur to me to list his being married as immoral, perhaps he is abusive towards his wife, or the circumstances under which he married her were wrong, but the attribute of merely being married is not something either surprising or unusual enough to make specific mention of, or a negative attribute. That being said, obviously people's views are not homogeneous, so I would love to see counterexamples to my impression of the general views of the times.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1wqnv4/whenwhy_did_it_stop_being_acceptable_for_western/
|
{
"a_id": [
"cf4qm51",
"cf4r1wv"
],
"score": [
9,
8
],
"text": [
"This has not disappeared, but depends on the country. Mistresses are common in France - for instance [François Mitterand](_URL_0_) was well known to have a mistress.",
"To this day, the morality of extra-marital relationships is viewed differently in different nations. In Western nations, broadly speaking, the practice is looked on more favorably in France, Italy, or Spain, than in England, Germany, or Scandinavia. \n\nThis change started around the mid-19th century as the ruling classes were subject to increasing media scrutiny of their affairs, with the \"moral hygiene\" movements of the 20th century signaling the end of upper-class men being able to conduct extra-marital relationships without at least *trying* to be discreet. "
]
}
|
[] |
[] |
[
[
"http://www.independent.co.uk/news/world/widows-in-weeds-mourning-mistresses--plus-ca-change-to-the-french-1323906.html"
],
[]
] |
|
4affit
|
Is it true that all ocean dwelling mammals have a terrestrial ancestor?
|
[deleted]
|
askscience
|
https://www.reddit.com/r/askscience/comments/4affit/is_it_true_that_all_ocean_dwelling_mammals_have_a/
|
{
"a_id": [
"d10hag3"
],
"score": [
13
],
"text": [
"Yes it is accurate. You can see in the physiology of the mammals why this is the case. If you look at the tail fluke, you'll see that marine mammals have a [horizontal](_URL_0_) fluke whereas fish like sharks have a [vertical](_URL_1_) fluke. This is because when the ancestors of marine mammals were on land, their legs were underneath them. Fish use lateral motion to move, and their spine is suited to this type of movement. Land-based mammals don't use lateral motion, and our spines have evolved to move in a different way as a result. When the mammals went back to water, they eventually developed flukes, but since our motion is forward/backward, a horizontal fluke would work while a vertical wouldn't."
]
}
|
[] |
[] |
[
[
"https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTfzg5bcnF1BhGK9AJR0G5MVnK_VF3c9XhPlOuFRpvlxi4MmuHg",
"https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSZeUIJPN4wEZzZbn5NRR1_XGINRzNSJhVZyD0GxQxxRfQMlTNX"
]
] |
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