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a5otdq | Often times, I read about game developers placing superfluous data within a game's files to take up disc space. A text file or audio file, for example, which serves no other purpose. Why was this? | I can't think of any examples, but I know I've heard of this somewhere. Edit: I should clarify what I mean: When I say 'superfluous', I mean it has no apparent purpose to the game. Not even an unused thing or a planned thing that later got scraped. In particular, I recall one instance of a text file that simply had random bits of poetry, lines from literature or gibberish inside of it. | Technology | explainlikeimfive | {
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"Sometimes taking up space *is* doing something for the game. Ex. a CD has a single spiral containing data going from the inside to the edge of the disc. However due to the way it works, reading from the edge of the disc (closer to the end of the spiral) is faster than reading from the center (the beginning). So take things like the PS1 for example, which already was not very powerful so devs tried everything to squeeze every ounce of performance out of the system. One of these tricks was that if you had empty space on the disc left over, you put in a junk file whose only purpose was to take up space at the beginning of the disc, therefore moving the actual interesting stuff closer to the edge of the disc, therefore getting a slight boost in IO performance for the files that are actually part of the game.",
"The data isnt superfluous when it was put in, it just often time removed from the game during development, but never removed from the actual code. Basically some higher up decided that they didnt want whatever it is in the game and tasked a programmer to remove it. The programmer just removes any way to actual interact with it and moves on with his life, because he is busy and its good enough. Its a simple and easy solution thats only downside is that it waste space, but with the current state of compact disks and HDD its not like anyone is struggling with game sizes.",
"I've done that when I've prepared gold master DVDs to be sent to a pressing plant for mass duplication. We produced and published DVD sets (computer OS patches, not games or movies) on a regular schedule, and I'd change up the contents of a tiny hidden text file for each set so that it was easy to check (and re-check, and have somebody else check, etc etc) that we were working with the correct master set for each release. Sending off the wrong version of the masters by accident would have been an extremely expensive mistake, and \"oops\" would not have paid the Modus Media bill for a bad run."
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a5p0io | Why do lightbulbs burst with light before going out? | Technology | explainlikeimfive | {
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"Incandescent bulb filaments get thinner and thinner as they are used, literally evaporating. Eventually some spot gets to the point of positive feedback: It gets thinner, so it gets hotter, so it evaporates faster, so it gets thinner,... As this reaches its conclusion, a bit of the metal gets hot enough to turn molten and then quickly create a small ball of glowing hot plasma. That ball of plasma dissipates in the bulb and cools off, coating the inside of the bulb in a thin layer of metal."
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a5p8x5 | how those finger sensors at the doctors office can tell what my oxygen levels are at. | Technology | explainlikeimfive | {
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"Red blood cells are a different colour when it's saturated with different levels of oxygen. So the light bounce off your red blood cells and the probe sees what colour it is.",
"Those sensors work by light absorption. Different wavelengths of light are passed through your skin. Some of those wavelengths are absorbed by your skin and don’t pass through to the detector. The wavelengths that are absorbed tell your oxygen level because hemoglobin (the red stuff in your blood that holds on to oxygen) varies in absorption based on how much oxygen it’s carrying."
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a5pzt9 | How do mobile games get away with advertising blatantly fake gameplay? | I'm not referring as much to the legality of the issue, as I understand it would be difficult to prosecute. I'm more curious as to how these adverts don't seem to be in violation of Google Play's own policies (I can't speak for the App Store since I've only ever used Android). A lot of these games promote fake CGI gameplay with a user interface attached on top to make it seem legit in an attempt to attract players who are probably not the most tech-savvy. This is exploitative no matter how you slice it, yet these games are somehow allowed to be hosted on the biggest app platform. | Technology | explainlikeimfive | {
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"It's not exclusive to mobile apps. You see it quite a bit in regular videogame commercials, I can remember them from the 90s showing little to no actual gameplay, or stuff that doesn't happen in the game sometimes, or bits and pieces of FMV sequences, etc. If it loosely correlates then it's probably given a pass.",
"What, specifically, is fake? Are you talking about graphics ridiculously better quality than the ads than in the actual game? Or are you talking about gameplay that is completely different from what is depicted in the ads (e.g. ad depicts matching the correct tool with a problem, when the actual game is just standard match-3 with some cutscenes)?"
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a5q1jy | What is YouTube Rewind? | Technology | explainlikeimfive | {
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"A video which you tube makes every year to show the collective trash created on youtube in that year featuring the youtubers who created that trash. ^Disclamer: If you make good content then you will not be part of it.",
"YT rewind is a collaboration video with a lot of yt creators made by yt. It's supposed to showcase popular videos, music and memes from the past year. Usually it's made to be one big music video. This years rewind however wasn't exclusively focused on trends from the past year but on what they company yt wants to showcase their investors and building their public image as a family friendly safe site. This however backfired tremendously. The community felt very disconnected, the way they video was edited made it feel really weird, it had pacing issues, a lot of big creators weren't in it (either because they were not asked or they declined) and the overall feel was that yt wanted to pat itself on their back for being an open minded nice community. If you've ever saw a comment section on any video on yt you know why that is a hilarious statement. That's why is has become one of the most down voted videos ever on the platform and became a meme itself in how bad it was."
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a5tw8l | How do they provide oxygen for the "space people" on the ISS so that they don't need to dock with refilling spacecrafts all the time? | Technology | explainlikeimfive | {
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"It recycles the air and scrubs the CO2 from it. Also recycles water from waste. It is very efficient.",
"First of all they do dock with spacecrafts all the time to refill their supply of among other oxygen. They have big tanks on the space station filled with oxygen that they can slowly release into the internal atmosphere. If they have issues with that they can use oxygen candles. This is the same concept is used for the emergency oxygen supply in airplanes. There are certain chemicals that when they burn actually produce an excess of oxygen gas which is breathable. & #x200B; But in normal conditions they rely on a quite complex life support equipment. There is two versions of these, one American and one Russian and just one can supply all the crew with life support. They get oxygen and hydrogen from electrolysis of water. The water is collected from wastewater and from dehumidifiers. Further on the hydrogen is combined with carbon dioxide from the atmosphere in a Sabatier reactor which generates more water and also methane. The methane is dumped overboard. So theoretically with all this working to optimally the ISS should only require resupply of food and hydrogen.",
"The do dock with visiting spacecraft all the time. One of the thing these cargo crafts bring is water, which is how the ISS makes oxygen. Water can be split into hydrogen and oxygen when electricity is applied. The ISS has plenty of electricity from it's solar panels, and it uses this to split the water. The oxygen gets used for breathing and the hydrogen gets combined with carbon dioxide to make water and methane. The water gets reused and the methane is vented into the space."
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a5xb1t | Why are game updates so big when the code is probably just a few hundered MB? | Technology | explainlikeimfive | {
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"> Why is Fallout 76's day one update 51GB? Because Bethesda screwed up, same reason their beta had people clicking the play button in the launcher and the whole game deleted itself. Fallout 76 is a bad reference Normally large patches come with new models and textures, these are the largest parts of a game. If you want to add a new character who looks different you need to add new art and models which are far larger than the code for their actions."
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a5xkl3 | How are perfectly looping gifs made from real videos? | Technology | explainlikeimfive | {
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"there's two main ways from what I've seen, you can either get to a section of the video and replay it backwards or find two frames, one from the start, one from the end and leave them as the first and last frame."
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a5xvj0 | Why are plural checks online often missed out or completely ignored? Example: You have 1 notifications | I see it so often and it makes me wonder, is it just laziness or does it have a legitimate reason? | Technology | explainlikeimfive | {
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"Usually when programming you preplan a sentence like this: \"You have & 1 notifications\". The & 1 then will get replaced. You have one sentence that works for every number. If you want the plural / singular, you would need two different sentences and a programming logic that chooses between the two. Additionally this logic will work great for english, but not for other languages, where plural may begin at 3, or it may have a multitude of different plural forms. So yes - it is laziness of the programmer, however doing this right is not as easy at it seems, so this can be much more of a timesafer than you might think.",
"Pretty much just laziness or an oversight. The code looks like this: > Add the text \"You have < X > notifications.\" to the page, where < X > is the number of notifications they have. versus this: > If the user has 1 notification, add the text \"You have 1 notification.\" to the page. Otherwise, add the text \"You have < X > notifications.\" to the page, where < X > is the number of notifications they have. It's not really any faster or easier to do the former; but people sometimes forget to add that check."
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a5zp5f | Speed squares used in carpentry. | I am a 1st year apprentice and I have only used my speed square as a straightedge. It says hip and valley and has numbers all over it, but I haven't used them once. | Technology | explainlikeimfive | {
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"text": [
"The hip/valley potion is used for building rafters, specifically, it's for measuring the angles for a [hip roof]( URL_0 )."
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a60i5j | Why are DJs important? What’s wrong with a playlist? | Not trying to offend anyone. Just genuinely curious | Technology | explainlikeimfive | {
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"A DJ is supposed to feel the room, feel the crowd and be able to adjust the songs they play on the fly to play whatever is the \"best\" song next for the patrons in the venue. They may even, and often do, cut songs down, and start a new one in early if one isn't working. A playlist can't do this, it just plays whatever you told it to play, in order, on time, and so on. It doesn't know that no one is dancing to the Britney Spears song, but a DJ will know in a few second and can mix it up.",
"It adds a live and unique atmosphere to a music setting. You feel like you’re getting your moneys worth rather than paying cover and $10+ a drink to listen to loud Spotify"
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a61f8i | How did Houston know what conditions would be like for a human on the moon to prepare the space suits just right to protect the astronauts during apollo 11? | Technology | explainlikeimfive | {
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"Nasa was very woried about the suits during the first moon mission. The astronauts were instructed to stay close to the capsule in case of emergency. Plant a flag get some samples and get out. They also where not sure if th spacesuits could survive a fall from one of the astronauts, so they had to be carefull. When they examined the suits they saw minimal damage so for later missions they knew that the suits where good. So from later missions we have footage like this. URL_0",
"We knew the pressure was 0, we knew the temperature ranges from sending probes in the Surveyor program and from published Soviet data from their landers. We knew how to make space suits from previous space flights and space walks Edit URL_1 URL_0",
"They’d made plenty of space flights prior to that with a ton of sensors testing everything possible about space prior to that.",
"Among things, animal testing. Not all the dogs came back in great condition, but by the time they sent a chimp, they had most of it figured out. A big piece of it for a while was underwater testing too. They got some practice in reduced gravity and got to check airtight conditions that they were already struggling with in airplanes.",
"We had collected quite a lot of data about the Moon before we sent humans there. We used **telescopes** to learn what the moon was (roughly) made of, that it had no atmosphere, and what its temperature was. We used **orbiting and crash-landing space probes** to get very detailed photos of the surface. This was the [Ranger Program]( URL_1 ) We used **robotic landers** to get a ground-level view and learn in great detail what the texture and chemistry of the surface was. This was the [Surveyor Program]( URL_0 ). The Surveyor lander program in particular was crucial. The first astronauts were extra-careful just in case there was an unexpected problem, but it turned out the robots we sent first gave us all the info we needed. BTW, the Apollo 12 mission landed right next to one of the old Surveyor robots and brought pieces of it back to Earth for study!"
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a6288d | How effective is regenerative braking on electric vehicles? | Technology | explainlikeimfive | {
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"Roughly 60-70% efficient overall. That is considering the kinetic energy of the moving vehicle and how much of it can be converted into kinetic movement of the vehicle later, not the efficiency of the braking in turning movement into electricity."
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a62mdu | Why do ads on paid subscriptions play better than the shows themselves? | To be more specific...I select a show to watch, I suffer through the ad, and then when the show I stayed to watch comes around, an error saying playback failure; cc hulu . | Technology | explainlikeimfive | {
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"Everyone in a given area gets the same set of ads so they are kept handy by the servers. Not everyone watches the same shows so they might be stored in a more distant, slower location. An analogy is a hardware store with rows and rows of different parts you can order, with a stack of flyers at the front counter. The flyers are always faster to get than any arbitrary part because everyone gets a flyer."
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a62ti2 | Why aren't you allowed cellphones and other wave emitting equipment in a mine? | Technology | explainlikeimfive | {
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"Cell phones do not work underground due to all the rock shielding the radio signals. So there is no reason to bring it with you. However in a mine there are lots of dangers that can potentially be triggered by cell phones. They often use radio signals to set off explosives. This was in fact one of the first used of radio. However the triggers they use are very simple as they are designed to be disposable and to not have interference. So it is possible that a phone can set off these explosives just like it can interfere with a speaker if you put them too close. And secondly a mine often have explosive atmospheres. They often have lots of explosive dust and can come upon pockets of methane or other explosive gasses. So anything that can make a spark is prohibited. Even a small cell phone will generate thousands of volts in its antenna. So if there is some sort of damage, for example water or soda having corroded away some of the material close to the antenna, then the phone might create a spark which can detonate the atmosphere."
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a6445y | How did Planet Earth II get their shots without disturbing the animals? | I find it hard to believe that there are people there while filming the bobcats fighting and if there isn’t anyone there do they hide the cameras to match the environment? | Technology | explainlikeimfive | {
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"They usually either use large telephoto lenses (like the Canon 1200mm L: URL_1 - this one is designed for photography, but it can be used with compatible digital movie cameras as well), or use concealment tents ( URL_0 ). Sometimes you use both at once.",
"Do they not show you the “Making of” segments at the end of each episode?",
"We watched a documentary called making planet earth or something like that. They explained how they used huge telephoto lens is and it took years to create that series"
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a64dio | Google Maps uses Mercator projection when zoomed out, giving a distorted view of Earth. Why does nothing seem to change as I zoom into those distorted areas? Surely there should be areas of Siberia, Canada, etc that look fucked up when zoomed in? | Technology | explainlikeimfive | {
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"First, Google Maps doesn't use a Mercator projection when zoomed out... at least not today on my browser. I get a 3-d spherical \"satellite view\". But anyway, what Mercator does wrong is that the scale depends on latitude: polar parts of the Earth look bigger than areas near the equator. But it doesn't distort the shapes of things otherwise -- it's called a [\"conformal\"]( URL_0 ), or shape-preserving, projection. So when you zoom in to Siberia, you're getting a magnified but correct view of what that part of Siberia looks like. But since you can adjust the amount of zoom as you like, you don't notice the magnification difference. It's only when you can see both Siberia and Brazil in in the same map that there's an obvious problem.",
"The difference comes with the scale of the zoom. If I zoomed in on Northern Greenland or similar, 6 mouse wheel clicks brings me down to a scale bar of 5km (bottom right). If I did the same 6 clicks in Central America, the scale bar is 20km. If you move the map north or south without changing the zoom, the scale bar will adjust. Not exactly a scientific method of working it out, but this would mean that Maps can preserve the weird shape of the Mercator projection even when zooming in - because zooming in at different latitudes ends up with different scales."
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a64uvd | How does inntagram know I recently bought a guitar without typing in guitar on their app? | The same thing happens to me with amazon and YouTube I won’t even search for guitar on any of their apps but they somehow know I own a guitar now. It honestly creeps me out a lot. | Technology | explainlikeimfive | {
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"text": [
"Metadata. Basically, anything you search up or look at is collected and sold to marketing companies which in turn are seen through advertising.",
"You probably researched it somehow, on Google or Facebook (FB owns Insta) for instance. Then the apps marketing platforms caught it, as they are interconnected, and mostly operated by very few companies.",
"Almost everything you do on the internet is recorded. What ads you click, what images your cursor hovers over, what products you've browsed and so on. The websites themselves rarely do anything with the data because it's too little, but it gets sent out to various companies that have trackers there. Google and Facebook, followed by many others. Other data they gather is the browser you use, screen size, operating system, phone type, IP .... Along with data gathered from many locations, they can create accurate profiles and guess within a limit some things about you. The data is then used by companies to target ads (we're told that's all it's used for, but you can see in China how that can be abused). Instagram for instance is owned by Facebook. Facebook and Google also search your messages/mails for things like this to \"better target\" ads. The bit about Facebook and other apps using the mike to listen in on users is said to be false ... but those companies are capable and willing, so who knows."
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a653hl | Why, in almost 2019, do we not have total network coverage for mobile/cell phones? | Technology | explainlikeimfive | {
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"For the large part: money. In some areas, primarily remote/rural areas, the costs of building out and operating cellular network towers may exceed the additional revenue the company expects from building/operating such towers, thus there is little or no incentive to build out such towers."
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a65sis | What is the difference between WiFi and Bluetooth? | Technology | explainlikeimfive | {
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"In general terms, WiFi is a protocol used to connect various devices to a central network, and is intended to take the place of in-wall cabling. Bluetooth is a protocol for devices to connect to each other and for peripherals to connect to devices, and usually takes the place of USB cables, audio cables or other smaller wires."
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a664dd | What causes a car's head gasket to blow and why do certain car brands seem to have a bigger issue with this than other brands? | Technology | explainlikeimfive | {
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"For manufacturing reasons, the cylinder head is fabricated as a separate piece of metal than the cylinder body. These two pieces of metal are bolted together, to enable maintenance, at a point where there are very high combustion gas pressures. These high pressures are essential to generate power with the engine, so the assembly must contain them. Neither metal has infinite stiffness and there are only a few bolts holding the head to the cylinder. This combination could easily allow combustion gas pressures to separate the two pieces of metal at the seam and allow gas to leak out - causing mischief. To resist this a compressible gasket is installed between the two pieces of metal and compressed by the bolts. The compression forces the gasket to conform to the gap between the two metal objects elastically, so that further pressure from combustion gas further compresses the gasket making the seal tighter rather than letting gas out. It's a great design, everybody uses it. Some manufacturers produce parts with higher precision than others. Larger gaps allow the combustion gas to apply more pressure, allowing the gas force to exceed the strength of the gasket material. Some manufacturers make engines with larger displacement than others. This encourages performance boosting behaviors which also can lead to pressures that exceed the gasket material strength.",
"Alot of factors going into a head gasket blowing but the most prevent is design, especially the motor design, how much HP, amount of stress on motor and so on. The reason so many subaru's blow head gaskets is the design of the \"boxer engine\" where the pistons go outward putting more stress."
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a66fpr | Why do PC and monitors/TV still have a VGA port? | Technology | explainlikeimfive | {
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"VGA is pretty common with legacy equipment, especially in the business space. It's less common in the consumer space, however.",
"Because there is a demand for support for legacy components. There are still quite a few VGA monitors and cables out there, and people want to be able to continue to use those components from time to time.",
"Same reason a lot of TVs still even have RCAs and a co-ax cable connection. First the electronics required to handle even the older signals have been miniaturized and maybe even put onto single chips; they're by nature of having been in market for 20 yrs very inexpensive, and they're not going to take up a lot of your board space. The D-subs or connectors are dirt cheap, so at this point keeping the old connectors and processing doesn't really cost the screen manufacturer very much. And while you may not use the old features very much if at all, the one time you needed it, go to use it and discover its _missing_, well thats when you angrily phone tech support. It would be like if you had a car stereo that was missing the AM radio stations. Yeah, everyone listens to satellite commercial free radio, podcsts or Spotify from their bluetooth phone, ipods on AUX or USB, and certainly noone ever listens to AM anymore. But imagine if you really needed to listen to the news and your Sirius subscription just ended, you go to switch on the AM talk/news channel and < gasp > no AM!? You'd fucking riot in the streets."
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a66qj8 | Software Architecture | I saw a video where Bill Gates states he still helps with the architecture for Microsoft. What is software architecture? | Technology | explainlikeimfive | {
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"Software is built of various logic and data components that interact with each other. Architecture design is determining at a very high level what these components should be, what they should do and how they should talk to each other.",
"Architecture is design. Some may add that it is a particular type of high level design. Let’s take the analogy of building a new type of car. Architects would make decisions like this will be a four door sedan, with a front mounted transversal V6 diesel engine and a five gear transmission. If the company has never built this kind of car before, architects would design how it will all come together, and what parts would need to be built and which ones could be bought from suppliers. Coders would be more like the factory floor workers who put everything together according to the blueprints produced by the architects. There maybe many other designers in the company who are not architects. They may decide the aesthetics like the shape of the hood or the color scheme. They may design the usability, such as the layout of the instruments on the dash. Even in the software world most people think of this aesthetic and usability function when they think of design, and not the engineering design of the way in which the transmission connects with the engine etc. Source: I had “architect” in my job titles for over a decade. Now I prefer “product”."
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a67b31 | How did spacecrafts come back to Earth from the Moon? Did the lack of Earth-like atmosphere on the Moon interfere somehow? | Technology | explainlikeimfive | {
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"Landing on the moon without an atmosphere was harder than getting off the moon without an atmosphere. Having an atmosphere means that as you go faster, you get more resistance to acceleration as the air has less time to move out of the way and let you pass. Think about moving your legs in water versus moving your legs through the air; the water is more dense and the faster you move your leg the harder it is to do/the more energy you exert for incremental gains. Most engines that we use for everyday applications extract oxygen from the air to help fuel their combustion. Rocket engines don't do this; the fuel contains an oxidizer, so that the rocket can create thrust in the vacuum of space. Landing on the moon, as it had no atmosphere, was a matter of using a rocket to counteract the momentum that was gained during the descent to the surface. Getting back to the earth from the moon is conceptually as simple as pointing your rocket the correct way so that you break free from the moon's orbit in such a way that your new orbit around the Earth dips into the atmosphere, which acts as a brake (aerobraking is the technical term) so that you don't need any further fuel to de-orbit the earth. I can't go too much more in depth without a crash course on orbital mechanics and the basics of rockets, but the concept behind what I just described is called a free return trajectory.",
"The lack of an Earth-like atmosphere on the Moon made it possible to design a spacecraft that could land carrying a spacecraft that could take off. Just look at how much harder landing on Mars is, and how really hard taking off and returning to Earth from Mars has been."
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a67hfq | How do Yubikeys work? | Technology | explainlikeimfive | {
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"There is a tiny computer inside. When you touch the \"go\" spot a circuit senses your electrical capacitance (you are not as good an insulator as air). This circuit tells the computer to \"go\". A fixed program in the computer reads some data from the USB port it's plugged into, does some cryptographic operations on it with a key that's safety trapped inside the computer, and outputs the answer on its USB port."
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a6a5pd | Why do URLs have %20 in them to represent a space? | Technology | explainlikeimfive | {
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"Computers don't understand letters, they only understand numbers. So back in the early days of computers, someone sat down and associated each letter and punctuation mark they wanted to represent with a number (actually, many people did this, but we're only going to talk about one). This was called [ASCII representation]( URL_0 ). In ASCII, the number associated with the space was 32, which in hexadecimal is 20 (numbers in computers are usually in hexadecimal). So that explains where the 20 comes from, but why is in the URL? It's because in the early days of the internet, they decided that URLs should only have a certain set of letters and punctuation allowed in them. Spaces weren't one of those. But people still wanted to communicate things like spaces in URLs, even though they couldn't actually put a space. So they decided that you could use a percent sign (%) plus the ASCII number of the thing you actually wanted. So wherever in a URL that you want to communicate a space, you can put \"%20\" and whatever program is looking at the URL will know that a space should go there.",
"In the spirit of ELI5, here goes... You've been taught that you can count your fingers and toes and get to twenty. What you *haven't* been taught is that you can actually treat each finger and toe like it's \"on\" (pointing up) or \"off\" (pointing down), and each finger to the left is worth double the previous one. Using this method you can actually count to 1,048,575! So right hand pinky is worth 1, next finger to the left: 2, next finger to the left 4, next finger to the left, 8, and so on. If you keep going through all your fingers and toes, if you added up every one of them (they're all \"up\") you get 1,048,575. Okay, next step... now, imagine that there are more than ten counting numbers... so once we go past 9, instead of writing 10, we write A. 11=B, 12=C, 13=D, 14=E, 15=F, and then we write 10 for 16 (so we wrap around after F). We could keep counting this way (11=17,12=18,13=19,14=20 ... 1E=30, 1F=31, 20=32, etc.)... Now we can group our fingers and toes into groups of 4 and each set of four maps to a number or letter (four fingers \"up\" would be an F for example because Up-Up-Up-Up (or 1111) = 1+2+4+8 = 15 or F). This is called hexadecimal. Since we have twenty fingers and toes, there are five groups of four fingers/toes, so the largest hexadecimal number we could represent would be FFFFF (which equals 1,048,575). Okay... last part... computers are stupid. When you boil it all down, practically all they can do is add numbers, retrieve numbers from memory, and store them back into memory. (Subtraction is a special case of addition, multiplication is adding over and over again, division is subtracting over and over again, powers are multiplying over and over again, comparing two numbers is a special case of subtraction, and so *basically* everything boils down to addition and pulling numbers from memory and putting them in memory somewhere else). Since computers can apparently only do addition (^(as explained below, this is sort of a little white lie, but it's close enough)), they really don't know anything about text. So how do they represent text? Well, every text character has to be represented by a number stored to a particular place in memory. If I put a \"42\" in a particular place in memory, an asterisk will display on the screen. There's a chart called an \"[ASCII chart]( URL_0 )\" that maps every text character to a number. 33=!, 34=\", 35=#, 36=$, and so on. What number represents a space? 32. Okay, so how would we represent 32 in our fingers and toes system (binary/hexadecimal)? Well, since each shift to the left doubles the value, 32 = 00100000. Now we split our fingers into two groups of four. We'd get 0010 and 0000. 0010 means 2, and 0000 means 0, so we would say that 32 converted to hexadecimal is 20. So when a URL wants to represent something like a space, it uses %20. It does this so that internet clients like browsers don't have to deal with special characters like spaces, tabs, and carriage returns. So that's why it works that way... %20 doesn't just represent a space, it represents a *way* to store *any* character in a URL... space just happens to map to %20 in hexadecimal.",
"It is the hex code for the space symbol. Since a space is not acceptable in a url, it gets converted to hex and then back to text in the process of sending and getting the url request.",
"There is some partial answer already bellow... Computers work with bits, not letters. Back in the old days of early computers, they made a table that associate each character with a number. The ASCII table was created. Space got assigned the number 32, which correspond to 20 in hexadecimal. We use the hexadecimal representation because it is easy to translate to bits. 0-9 then A-F for 0-15, this is what 4 bits can represent (16 values). Since computers use 8 bits per byte, you just split the 8 into 2x 4 bits, which can now be represented with 2 hex digits. For the HTML, you tell the computer that the next two characters are hex value by adding % before. (So %20 = 00100000). Now you know why space is %20, but why replace the space by %20? Because the http protocol do not allow a space in the address! When you request URL_0 your browser actually send this (and a bit more: GET /r/explainlikeimfive/ HTTP/1.0 Host: URL_1 Notice that there is a space between the address and the http version command. This is why the space is not allowed, because it is a command separator... And yes, there is 2 empty line sent after the host. So, since the space is a separator, and you want to have a space in the url, the only way to handle it is to send it as it's hex value.",
"So, just to add on a bit. URLs are really just filenames in directories on a server. So if there's a URL of URL_0 , that is very much like you pulling up File Manager, going to the Image folder, then the Funny folder and finding the 001.jpg. Back in the olden days, when everything was command-line, you ran into a possible problem with spaces--if I type in \"run program file\" do I mean that the computer's supposed to run a something named \"program file\" or do I mean that it's supposed to run something named \"program\" and start it out with the \"file\" option? There's no way to know. So spaces were disallowed (and the latter is what would happen in this example). So since URLs are just filenames, this is still present. Modern operating systems often \"mask\" this in the background, so it looks like you can have spaces in file and folder names, but it's actually got a %20 or something like that where the OS can see it. Since a URL doesn't know what program or operating system it's going to be used on, it can't be clever.",
"The rest of the answers are overcomplicated and somewhat off the mark. When your browser sends a request for a web page it sends a command to the web server like: < method > < url > < protocol/version > Example: GET /r/explainlikeimfive HTTP/1.1 The HTTP protocol doesn't allow a space in the URL term (or any other term on that line, for that matter) because space is used to delimit those fields from one another. It's like putting a comma in a CSV file field (which you can actually do, if it's escaped, but it uses a different form of escaping than HTTP does, read on). Sometimes you want to send a space (or other arbitrarily complex non-printable data) in a URL though, so URL encoding was invented, which escapes many parts of the byte range to %XX codes.",
"This is more ELI15, but because you know such term as URL I think it's more fitting. Specifically for space - because when some user interface (like a web page) interprets a link, they need to understand where it starts and where it ends. And they figure that out by spaces. If you put a space in the middle of a link, then it separates the tail of the link. %20 is a \"code\" of the space character, which does not split it (again, user interface looks for space to see where the URL ends to make it a hyperlink) This operation of transforming some characters to %SomeNumber is called URL Encoding. It is necessary because other characters are also what is called \"URL Unsafe\", meaning they control how the URL behaves and cannot be used to identify an actual resource the URL (universal RESOURCE locator) points to. Let's have another example. Look at this URL: URL_0 Here you can see that it is opening page \"Reddit\" on wikipedia and navigates to the section \"User\". That is because the # is a \"control\" character, meaning your browser will interpret it as \"go to that place on the page\" But let's say you want to search google for \"#eli5\". As you can observe, google puts your search terms in the address bar. What you will see in the address bar though is this: https://www. URL_1 /search?q=%23eli5 As you can see, # is replaced by %23. That is necessary so that your browser would not attempt to interpret it as \"navigate to eli5 section of this page\" instruction. However the receiving end of this request ( URL_1 ) will understand that %23 is a # character and present you search results accordingly You can use this online tool to play with URL Encoding yourself: URL_2 - and see what characters are substituted for what codes."
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a6cxzt | Why did the Brits ship IPA instead of other barrel-aged beers? | I learned that the extra hops in IPAs acted as a preservative that made the beer suitable for the many months' voyage from England to India. I also realize that those IPAs were shipped in barrels. Today, there are many less hoppy beers suitable for long barrel aging. Why, then, was the hops of IPA required in colonial times? Is barrel aging that much different now than it was then? Are the conditions of a ship vs a warehouse to blame? | Technology | explainlikeimfive | {
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"Nowdays we have efficient techniques for controlling microbial growth. At the time, they barely understood what microbes were, and many people didn't even know they existed. So, without having the techniques we have to preserve the beer, hops were about it. It's a food-safe antimicrobial that happens to add flavor."
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a6dimc | How do people animate nowadays? | Basically people like Namark , TheOdd1sOut, and JaidenAnimations seem to be able to animate their videos in such a beautiful way, what I don't get is how they do it so well in (relatively) little time. I'm comparing this to animated cartoon movies mosly. So the question is, do people actually draw all of these frame by frame or is there a program that makes the work of erasing/redoing/editing/moving much easier? | Technology | explainlikeimfive | {
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"They draw keyframes in software and the software does the inbetween. I think. I don't know who those guys you mentioned are though",
"Most modeling is 3d now. So they take a 3d model, move it into poses, then the animation software moves between the poses to simulate character motion."
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a6f9iw | Why are semi-auto marksman rifles not as accurate as bolt-actions? | Technology | explainlikeimfive | {
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"There are a lot less variables with a bolt action. They are simple and strong, and that makes for less ‘play’ in the action. Semi autos use a gas system, rechamber based on recoil and basically have more moving parts, which is more that can throw off the ballistics of a given shot. They are also often constructed to be more portable, and light. Which results in shorter barrel length, which means reduced accuracy. (I seem to have been informed this is more to do with velocity than ballistics, fair enough) Most modern sniper rifles also use more powerful rounds than ‘traditional’ rifle cartridges, such as 338 lapua magnum. These rounds offer superior ballistics, but are impractical for use in a marksman rifle, on the move with an infantry section. That said, it’s not always true. A modern marksman rifle is produced to a higher standard of accuracy than a bolt action sniper rifle from 100 years ago.",
"In general, bolt actions are more accurate than semi-automatic actions because of the movement of the bolt carrier when firing. In a bolt action, the firing system is static except for the firing pin; nothing moves until after the shot has been fired and the operator decides to cycle the action and eject the spent casing and force another round into battery (put a round into the chamber.) In a semi-automatic platform, immediate after the firing pin hits the primer and fires the round, the exhaust from the explosion forces the action backwards, ejecting the round, and then automatically loading the next. It's this forced movement that makes them a little less reliable accuracy-wise, since at a long distance, even a fraction of a millimeter (a super tiny amount) can end up as a significant difference. Thinking using your imagination, imagine GIGANTIC scissors that are 1000 meters long. if you close them, you might only move the handle a few inches on your end, but on the far end, because of the lever it's created, the tip will move much farther for the same amount of movement (and faster, too). That's it generally. The lateral movement of the action pulls the barrel, creating relatively minor movements that translate into larger differences downrange. Also, depending on the need, this might not actually be a big deal. Most modern military snipers, even in elite squads, use semi-automatic platforms. To them, in a scenario where it really matters, the difference between the two isn't significant enough to warrant sacrificing speed.",
"For some reason no one here knows how to talk to a five year old. The accuracy of a gun has a lot to do with staying still while the bullet is leaving the barrel. A Simi automatic gun has the bolt moving all the time inside the gun while the bullet is going through the barrel. Since it has to bring a new bullet into the chamber. A bolt action rifle does not do anything after the trigger is pulled. So the gun will move that little bit less while shooting. So that way the gun is a little bit more accurate.",
"Accuracy depend on repeatability so if you point the gun in the exact same direction and the air in front of it is the same the bullet hold hit the same point. Bolt action is just a barrel and a bolt you lock in place. All stay the same way when from the time you fire the bullet until it have left the gun and the shooter cycle the weapon. A semi-auto need a way to cycle the gun with the energy from that is released when you fire it. Common way are blowback that is using motion of the cartridge case backwards to the bolt or gas-operated by having a small hole in the barrel and let gas out and use the pressure. There are many variant and other to do that to. The problem is to do that in a way so the speed of the bulles it the same time and that the exact moment that part start to move and the vibration that introduce is the same for each shoot. It is not the case that the bullet have left the barrel before part start to move and gas is released so uneven operation will reduce accuracy. So you have you will have all the same problem for accuracy as a blot action have and you add problem by requiring the cycling mechanism to work the same each time.",
"Post your question to /r/longrange. 99% of the people in this thread have no fucking idea what they are talking about. Source: work in firearms industry, avid shooter, and know the difference between random fudds and people who actually shoot.",
"Tighter tolerances are designed into bolt action rifles. Semi autos need looser fit in order to function reliably.",
"Something that few people have mentioned is that old bolt guns are much less accurate than modern semi autos. The British P14-based sniper rifles of WW1, specifically chosen from the factory as the most accurate P14 examples produced are about a 3MOA (3\" group at 100 yards) on a good day, where a modern standard basic AR-15 should be good for 2 MOA or better. You can see this in US service rifle competition, where targets are today much smaller than they were just a few decades ago - rifles are just more accurate now thanks to modern manufacturing and metallurty. The days of the glass-bedded stock and accurized M1903 have been replaced by a free-floated AR-15 derivative."
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a6fc1k | Why is 24/25 fps okay for video but painfully low for gaming? | Technology | explainlikeimfive | {
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"It has to do with a difference in how the frames are formed. Individual movie frames are very blurry, but their blur isn't just a random fuzziness but instead something called \"motion blur\". That kind of blur contains information because it is formed from the movement of an object during the period of time the frame is being captured by the camera. Thus an individual frame of movie video contains information about the movement of objects during a short period of time, their relative speeds and paths. In contrast a gaming frame is calculated from a single instant of a complex simulation; while it takes time to calculate the image produced is of a theoretical instant. There is no possible difference of where an object was when the frame started to be captured and where it was after the frame was completed, and therefore true motion blur is impossible. Movie frames therefore contain more information than computer game rendered frames and tend to \"connect\" better than those from the computer as the motion blur paths connect between frames rather than jumping in short movements.",
"Because when you’re gaming there’s a huge dependence on responsiveness - it’s an active rather than a passive experience. Personally I think 60fps looks terrible for videos but I love high frame rates when gaming - and in fact it makes me a better player.",
"It would be completely intolerable without the huge amounts of motion blur added by the long exposure times. Even with the motion blur, film can look stuttery if you're used to higher framerates, or even flicker if your flicker fusion threshold is above 72hz(depends on type of projector). Basically, with a video game you expect to see what's going on when there's a lot of movement, but in a film it's just a blur that covers half the screen, and you don't notice the problem if you haven't seen a good action scene shot at a higher framerate. The motion blur makes it easier to make the movie look okay, because the blur hides mistakes, but it also will never look as good as a higher framerate with everything done right. Low framerates in video games also causes high input lag, in addition to a lack of smoothness."
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a6fuxn | Why some manufacturers can offer devices with insane GPS precision? I thought this was reserved for military. | I spent 2 hours repainting the lines on a rugby field yesterday. Plenty of time to think about automating this quite annoying task using an RC Truck combined with a drone controller+GPS. I searched the internet and found some manufacturers who claim that their automatic line marker robots can achieve a precision of +/- 1 cm. How is that possible? I believed that regular non-military GPS could never be that precise. Could this be because of a combination of GPS + GLONAS? | Technology | explainlikeimfive | {
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"\"Military grade GPS precision\" was (the absence/reversal of) an encryption algorithm being applied to the GPS signal to make it very slightly incorrect in a reversible manner. During one of the Bush administrations, don't quite remember which, the troops invading Iraq didn't have enough military GPS units to go around so their families started sending civilian ones in care packages. Since not knowing exactly where those troops were was a problem, the encryption algorithm was turned off. Since this proved to have significant economic benefits, it wasn't turned back on except around strategically important NATO locations such as powerplants and military bases. Precision has only improved since then, though I was under the impression centimetre precision wasn't available just yet so it may be those line marker robots combine GPS with some other positioning system. Visual recognition can give millimetre precision in real time in arbitrary surroundings while being powered by something that fits on a quadcopter, and is used by some vacuuming robots. Laser rangefinders and retroreflectors can give similar precision for measuring the distance between the Earth and the Moon. Source: hearsay.",
"More satellites helps. You can also get corrections from a ground station. You know the position of the reference receiver very precisely through other means, and can use that to calculate the needed corrections to improve the accuracy of other nearby GPS receivers. More importantly, you don't need to know the absolute position of the lines, only the position relative to some other feature that you can directly pull coordinates from, so the absolute accuracy doesn't matter, only the near term repeatability."
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a6h6by | Why we still need to do the whole "left eye/right eye, option 1 or option 2" when getting glasses? Why isn't there a machine that can test this just by looking at our eyes? | Technology | explainlikeimfive | {
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"Vision is a really subjective experience, affected by many factors including the exact shape of lots of different parts of the eye. You've got two choices: 1. Get a complicated, expensive machine that gives you an OK pair of glasses; or 2. Buy a simple, comparatively cheap set of lenses, and check to see what lenses make it easier and harder to see until you've got a great pair of glasses. I know which I'd choose.",
"There are now. My optometrist has a “pre-test” that gives a ballpark range to the classic machine they put on you. So instead of an unending series of better or worse, you read a line and have one or two corrections."
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a6ivqt | How are Lightning and USB-C connectors able to work in both orientations? | Besides the physical symmetry, of course. Other plugs like USB-A prevent you from using the wrong orientation because they wouldn't work that way anyway. What enables USB-C and Lightning to do so? | Technology | explainlikeimfive | {
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"No, it's really the physical symmetry. USB-C was designed to be symmetric because the Lightning solution (which was non-standard) was very well received by users. It takes twice as many connectors, more parts, more complexity, more gold; but yet users find it's very worth it not to have to figure out which side of the connector is up. There are other things that work this way, like car keys, and it's pretty well known in human factors circles as \"the right way to do it\"."
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a6j0l5 | What's the difference between an arduino and a raspberry pi? | What's their marketing? What can one do that the other can't? Which one is more popular? Which one is better? When do you use the arduino, when the RPi? Thank You so much!! | Technology | explainlikeimfive | {
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"Pi is basically a low resource PC, mostly used for single task setups (dev enviornment, router replacement, streaming service, etc). Arduino is a microcontoller for sensors. Controls robot arms, sensors, and has options for computing tasks.",
"Oh! I got this one. So Arduino is branded as a easy to use micro controller with a good community base. Now you're probably thinking, well what does that mean? So, basically, Arduino is used to control REAL LIFE components and parts. Some examples? Motors, LEDs, rfid chips, switches, buttons, relay switches, etc. You get the idea. All those physical components you interact with. Now raspberry pi is much more computer oriented. It is literally marketed as the computer with the most power for it's size. So, this means complex calculations, but it's mostly used for software projects. Let's say you want to build a small computer for playing a game, or you want to build a high powered complex calculator. Or you want to work on programming a operating system or software. You get this gist. In essence, it's a smaller, more portable computer. SO, Arduino is a controller for physical components, while raspberry pi is used as a mini portable computer. While each is greatly expansive and can honestly get wayyyy more complex, I've tried to really simplify it to it's basics for you so you can really understand what you're wanting to do and what you need. Hope this helps!"
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a6k1c2 | How much of the internet that I see is limited by my location in the world? | Is there a Chinese internet I just have never seen? It just seems like every website is in English and most news is about the US (that's where I'm from) | Technology | explainlikeimfive | {
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"If you're in a free country, you can read nearly every public site in the whole Internet. Including Chinese ones.",
"Well, the US is a disproportional part of the Internet. Head over to URL_0 . If you can't see that, you can't see China. Of course you won't see links to there from most English websites, because they don't use English on the site."
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a6muwx | what is the difference between disk capacity and density with a SSD? | I'm trying to upgrade my system and have a vague idea. Want to clarify before I buy. | Technology | explainlikeimfive | {
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"Capacity is what you really want, that's how much total storage the drive provides Density is about how much storage we can fit in one flash chip. Higher density chips enable higher capacity drives in the same size, or drives with the same capacity but fewer chips Density matters in the long run, it's what has enabled us to go from 256 GB 2.5\" SSDs to 2 TB 2.5\" SSDs; but when you're building a machine you only care about what you can get right now and that's capacity"
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a6nke6 | Why do integers have different sizes depending on the architecture of the computer? (64bit, 32bit) | Example: 64bit has integers the size of 8bytes and 32bit has the size of 4bytes | Technology | explainlikeimfive | {
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"That is by definition of an integer. From the Kerningham and Ritchie The C Programming Language, 2nd edition: The range of both int and float depends on the machine you are using; 16-bit ints, which lie between -32768 and +32767, are common, as are 32-bit ints. If you wanted explicit specific types, you should include stdint.h and use uint16_t, uint32_t etc. Everything else is just inherited from this.",
"The highest 32bit number, decimal 2,147,483,647, is in 32bit: 1111 1111 1111 1111 1111 1111 1111 1111 And in 64bit, that same number is: 0000 0000 0000 0000 0000 0000 0000 0000 1111 1111 1111 1111 1111 1111 1111 1111 Your question is basically the same as: how do the everyday, decimal numbers 982374 and 000000000000000982374 have different sizes. Which they do, because the latter provided more blank space for potentially larger numbers. We might in every day usage have supposed that that six-digit former number if increased to a million would simply warrant a seventh digit place - yet a computer, if expected to handle a seven-digit number, must be *guaranteed* a seven-digit slot."
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a6ojy8 | What is an API | Technology | explainlikeimfive | {
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"Think of it like you and your dog are two different computer programs. An API is like the words your dog has been trained to understand. If you say \"sit\" you know what to expect and the dog knows what to do and how to respond. On the other hand, you haven't trained the dog to \"lay down\" (it's not a part of the API) so it doesn't know what to do when you say it.",
"It is a defined way for one program to interact with another program or interface. It can be a way to access information on a website and use int in another way or the way that a program access the graphics card to draw on the computer screen. So a long the program follow the API and provide data as described you can change how it work behind that. There can alos be multiple program that support the same API. So you can talk to graphics card from Nvidia, AMD or Intel the same way without caring or knowing what graphics card is used."
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a6p1km | How do they replace lights on the top of tall temples? | Currently in Bangkok and absolutely do not understand how they replace the bulbs on the very top of these temples, specifically Wat Arun. I can't imagine there is an easy ladder access haha, do they literally scale these things? | Technology | explainlikeimfive | {
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"They are hollow. You walk up stairs or ride a small elevator. At the top there are handholds for climbing the last bit. Source: that's how they replace the light bulbs on the TV station tower I worked at."
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a6qa3k | Just A Random Thought: How did they find out that it was Plutonium/Uranium that was the perfect catalyst for a WMD? | Technology | explainlikeimfive | {
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"It's easy to narrow down a list of the most suitable elements by looking at their properties. Uranium-235 and plutonium-239 undergo fission readily and were thus considered, among other elements. Finding the absolute best is just a means of trial and error.",
"From a [previous ELI5 thread]( URL_0 ) on the research that lead to this understanding: Here is a _very_ basic version of the history that leaves out a lot but gets at your question: * Scientists had been probing the atom from the 1890s through the 1930s. The discovery of X-rays touched off a lot of new investigations into mysterious energy, leading to the discovery and understanding of radioactivity, and the understanding that atoms had a dense center (the nucleus) made of subatomic particles and could be \"probed\" by shooting radiation at them. * In 1932, Chadwick discovered that there was a neutrally-charged subatomic particle, the neutron. This was very exciting and interesting because its lack of electric charge meant that it would not be repelled by either the electrons or the protons in the atom, and so could be used for probing experiments. In 1934, the Joliot-Curies discovered artificial radioactivity, that shooting non-radioactive atoms with radiation could change them and make them radioactive. * Inspired by this research, Fermi started experimenting by bombarding elements with neutrons. He found that slowing down the neutrons first (by making them move through carbon and hydrogen paraffin, which made them lose energy) meant they were more easily absorbed by other atoms. He shot neutrons at uranium with the goal of making new transuranic (heavier-than-uranium) elements. (Uranium was the heaviest-known element at the time, and is the heaviest element that one finds in abundance on Earth. So you'd be making something totally artificial and new if you could make something trans-uranic.) He published this in 1936 to widespread acclaim and won the 1938 Nobel Prize for the work. * In 1938, Hahn and Meitner were working on similar experiments as Fermi and were suspicious about his claims to discovering heavier elements. They repeated Fermi's experiment, shooting slow neutrons at uranium, and then did very careful radiochemical analysis of the byproducts. They found, to their surprise, that there was a lot of barium left over. Barium is about half as light as uranium. They concluded that instead of making new heavy elements, the neutron was instead splitting the uranium (nuclear fission). They understood that this would release a lot of energy. * In 1939, scientists across the globe were excited by fission. Szilard in particular was one of the first to realize that if neutrons caused fission, and fission caused more neutrons, then you could set up a nuclear chain reaction that could be used for a reactor or maybe even a bomb. He attempted to get people to stop publishing on the topic, fearing the Germans would try to exploit the technology for military purposes, but his attempt failed. Joliot published that he had discovered that fission reactions do release sufficient neutrons in 1939, thus making clear to the world that a nuclear fission chain reaction was theoretically possible. * But also in 1939, Bohr and Wheeler articulated a theory of fission that showed that, while it would be possible with nearly-pure uranium-235, natural uranium would not be usable in a bomb. Since separating uranium-235 from uranium-238 on an industrial scale was thought to be very difficult, this seemed to make a bomb seem more or less remote. A reactor might still be possible, however. * Between 1939 and 1941, many countries had scientists that explored the question of whether bombs were a problem to be worried about. In England, Frisch and Peierls calculated that it would take only about 10 lbs of uranium-235 to make a bomb, a very low estimate compared to what others were thinking. This made it seem suddenly much more feasible. They wrote up a report with other British physicists that concluded that the US and Germany could probably make an atomic bomb in time for use in the war, but the UK could not. They sent this report to the US in the summer of 1941. * In the US, there was a very small research effort into this topic but it wasn't really going anywhere quickly. In 1941, the UK report spurred more attention, and around this time they also discovered that if you did have a nuclear reactor working, you could make another element, plutonium-239, which might be also usable in a bomb. It was decided to start a more engaged project to see if producing the fuel for a bomb was possible. * By 1942, there was sufficient success that the US scientists convinced President Roosevelt to authorize a full-scale program to make a bomb, run by the Army. This was the Manhattan Project. It was started in late 1942, and was going full-scale in 1943-1944. By the summer of 1945, after overcoming many challenges and essentially creating an entire industry from scratch, employing hundreds of thousands of people and spending billions of dollars, the US had enough bomb fuel (enriched uranium and separated plutonium), and bomb designs, for three weapons. One was tested in July 1945 (Trinity test) and the other two were dropped on Hiroshima and Nagasaki in August 1945. It was much harder than they expected and the estimates they had used to justify the program initially turned out to be off by a lot. But once committed to doing it, they saw it through. So the short answer is: scientists were looking at a lot different issues in their course of understanding what atoms were and how they worked, and sort of stumbled on the discovery of nuclear fission without looking for it. Nuclear fission was the key discovery here, because it is the key to unlocking the energy bound into heavy atoms at will (via the chain reaction). Once that was discovered, a lot of people realized it could maybe be used in a weapon. Even then it took some time and effort to decide to commit to the building of a bomb, and it wasn't easy to do. So it is a combination of \"the result of a long train of thinking about the atom,\" \"a lucky (or not) discovery,\" and \"a lot of further studying of the issue followed by a HUGE effort to make it work.\""
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a6qflo | Why are the three primary colors red, yellow and blue, but computer system color palettes use red, green and blue as their base colors? | Technology | explainlikeimfive | {
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"Red, green and blue are the primary colors of light.. Combining all three gives you white Red (magenta) yellow and blue (cyan) is the primary colors of pigment. Combining all three is viewed as black (or more technically such a clusterfuck of darkness that we define it as black)",
"A primary color set is any combination of colors that can be mixed to produce all (or most) other colors. Red/blue/yellow was the standard combination for watercolors in the 19th century. Red/blue/green is based on human biology, since those are the three colors our cone receptors perceive. Another common primary color set is cyan/magenta/yellow/black, which is the staple ink array for color printers. The black isn't necessary to produce a color per se, but rather to save on other colors when printing darker shades.",
"Think about the sun. It emits white light. What this really means is that it emits red, green, and blue light. These colors can be combined in various combinations to make white light. So white technically is not a color. In physics, it's defined as the sum of all possible colors. If you pick up a prism, you'll see that white light is split into all the different colors. Now think about something black. It absorbs all light. So black is not a technically a color either because it is defined as the absence of all light. So why are red, yellow, and blue considered primary colors? These colors are really talking about pigments. They absorb all light except for the color in question. So red absorbs all colors except red. So white light hits the red pigment, then all the colors are absorbed except for red, which is reflected off. If you combine red, yellow, and blue paint, the resulting paint absorbs all colors, which is black. So red, green, and blue are the colors that light sources emit. Together they combine to be white. Red (magenta), blue (cyan), and yellow are the pigments that absorb light, except for the color they can't absorb which they reflect. Together, they combine to form black. White is the presence of all colors of light, and black is the absence of all colors of light."
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a6qkqc | How does the process for animated movies even start and how do they make everything run perfectly together? | Technology | explainlikeimfive | {
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"Movies started out as individual film photographs. Movie cameras captured live action, but once you had that long strip of film you could do stuff. Some early \"special effects\" involved inking black-and-white film prints to turn one object a color. From that experiments were done with in-camera double exposure to add sparkles to a scene. When cinematographers got tired of the limits of in-camera work, they said \"Hey, cameras can take pictures of drawings.\" and started taking pictures of drawings to add special effects. Then cartoons just gave up the live footage and did it all with drawings. Walt Disney got an academy award for his development of a multi-plane camera to better photograph cartoon drawings in 1937, and that became the standard approach."
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a6qnnl | What happens when you click the 'cash back' button when you pay with a card at checkout? Is that a credit card only thing? How does it work? (Ive only ever had a debit card, if that matters). | Technology | explainlikeimfive | {
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"It's a **debit** card only thing. Basically, the shop overcharges you by an amount of your choosing, and hands you cash as \"change\" from the purchase. This way, you can grab some walking around cash without having to go to an ATM. Your bank sees it as a normal part of your shopping.",
"Its only an option when you pay with debit cards. If you buy a $5 thing and choose $20 cashback, the store takes $25 out of your account. Useful if you've got plans to shop somewhere that only takes cash."
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a6rk1s | How do cameras capture high quality photos in the dark or during the night? What is needed to do this? | Technology | explainlikeimfive | {
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"The more sensitive the sensor is, the higher quality you'll get in low light. Having a larger sensor helps with this since you have more light hitting each individual pixel. Also, a larger and higher quality lens that can focus more light onto the sensor helps. The alternative is a longer exposure where the sensor reads the light hitting it for longer. The downside to that is if an object moves while the sensor is reading the scene that object will be blurred. If the exposure is long enough and the camera itself isn't held steadily enough the entire image will be blurry."
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a6rscr | If cell phones are based off radio, how do we still get service deep inside buildings, etc.? | Peaked my interest whilst pooping and browsing Reddit via LTE... | Technology | explainlikeimfive | {
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"Some of the radio signals actually can penetrate buildings well. Especially signals below 1000 MHZ. Also some buildings have signal boosters in them that most people don’t even know about."
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a6rtsl | How does Bluetooth Low Energy Work? | I've seen it on my phone before. I have a Samsung S9+ and I look into settings and says it uses Bluetooth Low Energy. Or LE. It uses it's microphone to find devices to connect to and to transfer data files with. What is Bluetooth Low Energy exactly? It says it will use a bit of battery (3500mAh Capacity from the phone) How much can it use theoretically? | Technology | explainlikeimfive | {
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"Bluetooth is a way to communicate to other devices wireless, The most common application on a cellphone is to connect to headsets, spearker etc Bluetooth low energy is the latest bluetooth standard that do what is say and used less power. The amount is usages depend on what you do but it is low. The lower power usage is more important for something you connect to like a headset or a fitness trackers then for a cell phone as the have smaller batteries and you still has to charge the cellphone for other thing is uses energy for. So it can result in standby time on devices like that for days, weeks or even longer. If you look at example for a bluetooth low energy beacon I found tests that show usages of 38 uAh per hour that is 0.038mAh per hour. That would mean that the the battery could power it for 92000 hours or 10 years. Bluetooth low energy is designed so a button cell battery that might have 200mAh could power it for months or years. The cellphone that need to listen for signal uses a bit more but it will be negligibel for a cellphone. That is for standby if you stream to speaker or headphones it might use more power"
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a6sih7 | Why isn’t Braille just raised letters? Wouldn’t it make more sense if it was? | Technology | explainlikeimfive | {
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"Not for reading it quickly. It's designed so that each letter is distinctive by touch - Braille readers don't have to feel each letter individually, they can just run their fingers over a row and read it all at once. Another thing is, for someone who's born blind, they might never have learned what \"normal\" letters looked like - and would not need to. Also, Braille is easy and cheap to produce. You just have a grid of 3x3 or whatever punches, and for each letter, you only activate part of the needles - actually a lot easier to \"type\" than a regular typewriter where you need dozens of buttons and individual arms.",
"It's real hard to distinguish standard letters by touch. Consider, for example, D, O, Q. A 3x2 grid is a lot easier to feel out. If you don't mind weird looks, you can try feeling out some signs in public. Also, there's contractions in braille that don't correspond to standard letters. Some are consonant clusters (dot pattern 16 makes ch, for example), and some are whole words (dot pattern 5 + 134 (m) makes mother). This is used because braille takes up more space otherwise.",
"Imagine being blind and trying to feel the difference between an O, 0 or a Q. ~~See~~ Feel what I'm sayin?",
"Raised letters like you describe is how writing for the blind was done before Braille was invented. Braille is much better, as it's easier to read quickly, and also reasonably easy for a blind person to write by themselves (using a stylus and tablet). [The Wikipedia page on Braille]( URL_0 ) gives a decent overview of its history. As always, with a Wiki source, you should consider reading the references, in addition to the main text if you want an authoritative perspective."
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a6sjvb | Why is Windows 32-bit referred to as x86 and not x32 while 64-bit is referred to as x64? | Technology | explainlikeimfive | {
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"The 8086 was an early Intel processor which led to the 186, 286, 386, and 486. The architecture was called x86 and anything compatible with it was x86 compatible. These were some of the earliest and most wide spread 32 bit processors. Then AMD comes along and extends x86 to support 64 bit addresses and they name it x86-64. This later got shorted to just x64 for most situations x86 and x64 both refer to architecture styles not bits, but those architectures are built for 32 bits and 64 bits respectively so many people use the terms interchangeably.",
"as people have explained, the x86 series of CPUs became synonymous with 32-bit and so it's just a nickname. but as for how the \"x86\" name came to be... Intel's first chip was 4 bit and they called it the 4004. it powered a calculator. later when they upgraded that they named it 4040. when they released a 8 bit version they simply changes the 4s to 8s and called it 8080. a more powerful 5 volt version was called 8085 and the 16bit version was called 8086 this 8086 design is what the later 80186, 80286 and so on designs were based on. so the x86 name can be traced back to Intel's first processor",
"x86 is an instruction set that intel used, which was 32 bit. Then, intel and other big fabricators put all their money into Very Long Instruction Word (VLIW) architectures, which turned out to be an utter disaster. In the meantime, AMD actually developed an architecture which was literally just x86, but with 64 bit instructions, which ended up being called x64. That's why AMD actually owns the license to the x64, not Intel. After finding out that VLIW didn't work very well, Intel and AMD made a deal where they just gave each other licenses (Intel licensed x86 to AMD, AMD licensed x64 to Intel) and now everyone just uses x64 on the desktop side.",
"The CPU series that PC i base on start with the Intel 8086. The you have the 80286, 80386 and then the 80486 all made by intel. The then move to Pentium because the could trademark the number. The family is commonly called x86 where x stand for any number. Technically the 32 bit version of the instruction set is called IA-32. But after 80386 all chips in the series used that so people just called in the x86 without specifying the bit version. Windows NT have existed for IA-32, x86-64, ARM, Itanium, DEC Alpha, MIPS, and PowerPC and the common way to refer to the IA-32 version is just x86 When AMD released the 64 bit standard in 2000 the called it x86-64 but people started to call it x64 as it is shorter and have the same format as the older one and that is what windows started to use"
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a6swcj | How do wireless chargers work? | Technology | explainlikeimfive | {
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"> I know that charging a battery is essentially moving electrons back into the battery That's not really how it works. Electrons aren't \"spent\" when you use power from electricity. The electrons are all still there. No electrons have been lost. Electrons don't go back into the battery. Electrons are charge carriers. They carry energy with them. That energy can be depleted. But the electron is still there. --- Wireless charging is done with induction. Basically, a current in a loop will cause a magnetic field; a magnetic field will cause a current. The charger creates a magnetic field, and that causes a current in your phone, which charges it."
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a6tnuw | How do subtitles on streaming services work? | what is the technology used for the subtitles on Netflix and Hulu? Have they actually typed out the script to everything streaming on those platforms? Thanks | Technology | explainlikeimfive | {
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"Yes, someone did have to sit down and type them out. Usually it's done by the studio for closed captioning (on TV) or subtitles for the DVD/blu-ray release, then they just send the files along when they license the content to streaming services. For Netflix Original stuff, then yeah Netflix would have to hire somebody to type everything out. I suppose they could also work from a digital copy of the shooting script and just add the timecodes."
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a6ua46 | why law enforcement uses polygraphs but they are not admissible in court | If polygraphs are not reliable enough to be admissible in court then why do law enforcement use them to help eliminate suspects or possibly confirm their suspicions? | Technology | explainlikeimfive | {
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"It is a useful tool for finding pressure points. There are two types of modern police interrogations - reid method and interrogative. Interrogative - That is basically questioning people until you catch them in lies. Knowing which questions to ask is very helpful. Reid method is basically accusing them of doing something in a manner that follows a storyline. Obviously, a trained liar has a better chance of passing a polygraph with discipline. Thing is that most criminals aren't highly trained or as sociopathic/anhedonic as is required to maintain the cool required to pass a polygraph in a simple criminal investigation. While the polygraph can be very revealing, it isn't considered admissible because of the technical arguments for guilt are easily refuted with arguments by the defense for \"innocent behavior\".",
"Mind games. Polygraphs make people nervous. It's harder to lie or keep a story straight when you're nervous. This means you're more likely to say something the cops find suspicious or incriminating - even if you're innocent. You might even get so nervous to confess to something you didn't do or some other bad thing you did do."
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a6wa9r | What does Netflix have to gain with "are you still watching?" | Why does Netflix have this feature? Surely without it there would be more watch minutes, better numbers, and all around just beneficial to Netflix. So why add something that stops the customer from using the service? Not only that, but why make it uncontrollable by the user? There is no way of turning it off as far as I know. | Technology | explainlikeimfive | {
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"A reduction in required server bandwidth. If people fall asleep and the stream keeps going, it's adding demand that could otherwise be allocated to users who are actively watching.",
"I like it because if I fall asleep watching a show it makes it slightly easier to find where I left off. Also you are paying the same amount of money per month. Doesn’t matter if you watch 3 hours a day or 1 hour a week.",
"They have to pay money for server costs to stream you data, plus of course some customers have data caps or limited data available, so would prefer to not \"spend\" data on things they aren't watching as streaming HD video can be intensive, with 4K obviously much more. It saves Netflix money, and potentially saves a consumer money if they are not actually watching.",
"You pay Netflix a monthly fee. They want to provide the least amount of service they can. Every second they stream something to you, they have to pay for that transmission. If you're not even watching, it's a waste for them. They lose money the more you watch. Compare that to Youtube. They make money through ads. The more ads you see, the more money they make. So if you fall asleep in front of Youtube, that's a bunch of ads they stream to you. They can't tell whether you actually watched them or not. All they know is that you sat through 50 ads, and they can charge for each ad seen. The more you watch, the more money they make.",
"Maybe it's to not drain watchers data if they fall asleep ?",
"I don't think it's to maintain server costs. I think it's to make sure that their ratings are accurate when they want to see how much people binge watching certain shows."
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a6xs9a | Why do USB connectors have 2 sides? Every time I go to plug one in I have to turn it around... | Technology | explainlikeimfive | {
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"The thing is to realise that USB cables weren't created out of the blue; they were a solution to a problem, and that problem was the frankly nightmare situation that existed in the 90's of different connection standards. The rear panel of a PC would routinely have several formats of serial ports, perhaps a parralell port or two. You might even see a SCSI or two. USB (Universal Serial Bus) was a way of unifying all of these different things with not only a standardised pin layout, but also a communications standard so that plug and play became a possibility (prior to which you had to install specific drivers for absolutely everything, plug in stuff before the PC was turned on, and constantly restart the machine). For USB to get widespread industry take-on it had to be simple, cheap, and easy to implement. Previous connector designs had a whole host of fragile pins which could easily break or bend. Particularly when people were mucking around at the back of a machine in the dark and kept jamming the plug into the socket the wrong way around. USB did away with this by using contacts that were reinforced against a plastic base. This made it impossible to insert the plug the wrong way around, and meant damaing the pins was almost impossible. I cannot sufficiently express how welcome USB was when it started replacing the nonsense that had gone before. YOu know those people who have drawers and boxes of old defunct cables? That is because they were bullied into it by years of incompatible standards, and fragile things breaking, which meant you NEVER threw away a spare, and you always kept hold of old ones 'just in case'. USB has evolved a lot, and the new USB3.1+ Type C is indeed reversible. It took as a while to get here, but we got there in the end.",
"The standard Type-A connector has four pins. The leftmost and rightmost, if you're looking at the connector with the pins on the bottom, are the ground and +5V pins respectively. The connector is not symmetric (i.e. it can't be inserted upside down) for two reasons: one, the pins are all on the same side; if the cable didn't have the obstruction, the pins wouldn't connect. The second reason is so that the pins match up to their proper pins on the port side. It could be pretty disastrous if the voltage pins were reversed. USB Type-C has its pins arranged such that no matter which way it's oriented, the pins present the same function to the port.",
"The real question is why are they rectangular and not trapezoid. Like the USB mini or printer connector. If a computer expects 10signals/wires in order 1-10 it will usually not be happy if it receives 10-1 so they make it you cant plug it in upside down."
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a70jva | Why do phone batteries seem to die faster in colder weather? | Technology | explainlikeimfive | {
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"Because lithium ion batteries perform worse in the cold. They need some heat in order for the ion flow (which makes the battery work) to work properly.",
"Remember that although a battery produces electricity, it itself is a chemical-based system. Most chemical reactions an be assisted by increasing temperature for some degree, which is why the same reaction(ion flow to produces electricity) doesn't happen as easily if it's cold.",
"Batteries like I'm a car or in our phones work by having two parts of a chemical reaction occur at to electrodes where the electrons deposited on one and grabbed off the second can't just pass through the liquid (or other medium). What we can then do is attach a wire with something that will do work in between and the flow of electrons drives that work as they flow. The thing is, a chemical reaction usually requires a bit of energy to occur, even if it emits more energy than that bump up. The next thing to consider is that temperature is a measure of the average moving around each particle is doing (kinetic energy). So if we have these particles bumping into each other, sometimes two fast ones will plough into each other meaning there's a big waves of energy with them in the right place to react and so it happens. Sometimes two slow ones will two each other and nothing will happen. It's a little like if you had bumper cars with loose bumpers. Light bumps isn't enough to do enough to do damage but a head on hot will knock bits off. Cold temperature is like all the bumper cars going slowly. You are much less likely, in each bump, to have enough energy involved. Add to this that as you have the reaction occur you get more \"inert\" bumper cars that will never cause damage no matter how hard they hit getting in the way. To keep enough electrons being pushed onto one anode and snatched off the other you need enough bumps at sufficient energy per minute, at a warm temperatures you get more of the crashes achieving energy so \"enough bumps\" number is reached with more \"inert\" bumper cars added. At colder temperatures the threshold is reached after fewer crashes."
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a71cq2 | How do they make these piped cookies with truffle centers? | A Costco cookie assortment made its way to my office for the holidays, and these mint chocolate cookies were among them. I'm an above-average home baker, but I cannot for the life of me figure out how they get the truffle center into what looks like a piped cookie. [Pictures of the cookies here]( URL_0 ). The stripes are solid from the bottom to the top, so they don't appear to be piping a base, adding the truffle, and then piping on top. The cookies are delicious but would be made much better if recreated at home... I just don't know how! Any ideas, ELI5? | Technology | explainlikeimfive | {
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"So there's basically a bigger \"central\" nozzle that pipes in the truffle center, and then this big nozzle is surrounded by smaller nozzles for the alternating mint and truffle. All of this stuff is fed through yet one more nozzle which drops and lifts the actual cookies on the production line. It may be easier to imagine one big pastry bag (filled with truffle), surrounded by a bunch of smaller pastry bags (filled with alternating truffle and mint) which are stuffed into an even large pastry bag (which is what you use to squeeze out each cookie). I did a quick internet search and came across a product which would achieve a similar effect, but at least you can see how the components would fit together & how it is possible to achieve the effect in your pictures. URL_0"
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a71qhl | if heat creates energy, why have humans not yet tried to harness the power of the earths core? | Technology | explainlikeimfive | {
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"text": [
"...we do, it's called [Geothermal Power]( URL_0 ) So yes, it's plausible, because we're doing it.",
"We do harness this \"geothermal\" energy in places where it's plausible to do so. Usually you have to bore *really* deep (miles) to find temperatures sufficiently high enough to drive a power plant, but in a few geologically active areas like Iceland the heat of the mantle is much closer and can be accessed. Some geologically active areas are *too* active though and can't be tapped safely."
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a71ufn | Nueral Networks. | Technology | explainlikeimfive | {
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"I saw a TV programme years ago that showed a \"machine\" built out of matchboxes and coloured beads that could be taught to play tic tac toe. Turns out that it was effectively a mechanical neural network designed in the '60s named MENACE. Details here: URL_0",
"Imagine you take a group of blind men and an elephant. None of the men have ever seen or heard of an elephant before except for one. You place each person at different parts of the elephant and tell them on the count of three to reach out and shout what they think they are touching. You take the one that has heard of an elephant and you tell him to guess what it is based on what everyone is shouting. Ok, ready? 1, 2, 3 go. \"It's a tree with giant leaves\", \"it's a snake\", \"it's a leather wall\". This goes on until the observer can guess it's an elephant. If he can't guess you might give mega phones to some of the shouters so that they stand out more too the observer. Or you might place people at different parts of the animal to get different inputs. This goes on until the observer is able to guess it's an elephant. The above isn't exactly accurate but it's close. A neural network is essential a bunch of nodes that are capable of recognizing very specific parts of a whole. Is it orange? Does it have 4 paws? Is it covered in fluff? If the node is triggered, it sends a signal that it's been simulated. Other nodes connected to these nodes (which is why it's called a network) may then also fire until the signal is recognized. It's a cat! Sounds crazy but this is the way your brain actually sees the world. Enough simulated nodes that fire together make you think you know what you're looking at."
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a73jws | After seeing Peter Jackson's Restored Footage, why is a lot of old footage look like it's in fast-forward? | Technology | explainlikeimfive | {
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"So, video of all sorts is just a series of still images that gets changed really quickly. Each image is called a *frame*, and how many images you see per second is called the *framerate*. Old footage, as people have noted, used hand-cranked reels to expose the pictures, and these had a pretty low framerate that wasn't quite consistent. However, playback devices would play that film back at a single standard speed. Let's say for math's sake that 30 frames per second is your playback speed. If you recorded at about 15 frames per second, then each \"second\" of your video is only going to take half of a second when played back, making it look like your video is running in fast motion. Similarly, slow-motion cameras that we have today record in speeds of like 5,000 frames per second, but we play them back at 30 or 60 frames per second (Depending on the format), and so every 1 second of original video takes ~10-20 seconds to replay. Nowadays, with digital video files, if you have something that was recorded at 30 frames per second and need to replay it at 60 frames per second due to a newer standard, it will insert computer-generated \"tween\" frames that try to get a good approximation of what should happen between the two frames to make sure the film plays at its' original runtime and doesn't look sped up.",
"Older cameras had much lower frame rates than normal modern cameras do. The ones in WWI recorded at 10-15 fps while modern is 24-60.",
"The movie cameras back then were driven by a crank handle and, while the playback speed was regulated, the filming speed was not. If the camera operator cranked too slowly, the movie would appear to be running fast."
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a745zd | Why does Redsit use so much Data? | Whenever I use Reddit for an extended period of time while not connected to a WiFi source, I can use up to 40 megabytes within a half hour period. Why? | Technology | explainlikeimfive | {
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"Reddit needs to load a ton of images and text when scrolling, just like Twitter does. The images can take up a lot of space overtime.",
"A lot of images on reddit are 1/4 to 1/2 of a megabyte. A bunch of comments and their associated metadata can be 1/4 megabyte. So, if you look at 2 posts a minute for 30 minutes, at half a megabyte each, that would be 30 megabytes. If you end up watching videos or gifs, that will go up quickly, as they're even bigger."
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a74hb3 | why does old black and white video footage almost always look sped up. | Technology | explainlikeimfive | {
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"Back then, they were cranking the film while they were filming it. This is before technology could automate the timing. They figured that cranking a little too fast worked better for the story. Or maybe they just thought that the film was boring so they were trying to speed it up for ya"
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a75k4x | How do flash drives keep data stored when they have no power | Technology | explainlikeimfive | {
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"The flash storage device use what is known as a floating gate transistor. That is a transistor where one of the wires are not connected to anything. Therefore you can charge this wire and then later check the charge of the wire by checking the state of the transistor. However if you do not have any power to the transistor the charge in the floating gate will just be left there as it is not connected to anything. There is nothing to discharge it. So this charge can be maintained for a very long time before it becomes impossible to detect any longer.",
"Lots of things store information without power. The magnetic strip on your credit card stores information in a magnetic film. Flash drives don't use magnetism, rather they store information through the charge in tiny capacitors."
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a7ac3m | Will a Youtube video with a still background require the same processing power as a moving video ? | Technology | explainlikeimfive | {
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"No, Youtube doesn't send the video as a whole and sends every pixel, even if it doesn't change, they will send the changes between frames, so a completely still video uses less data and therefore involves less work. How big the difference at the user-side is however, I can't say.",
"No, there would be different levels of load for a still background and an actively changing video. For basics you should know how lossy compression works, you can do that in this article: URL_0 And for ELI5: video is not transmitted \"as-is\" for every pixel, it is encoded as \"difference between previous state and current state [of a small portion of the picture]\", so a static background requires to be \"drawn\" once and after that only \"nothing changed\" information is needed, while active changes will require constant \"this picture changed like that\", thus requiring more CPU or GPU power to process."
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a7aq6b | Why can't the mouse cursor move off screen on the left side when it can on the right? | Technology | explainlikeimfive | {
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"The cursor is actually only one pixel. The top left pixel of the pointy thing So when you run it to the right most of the pointyctjing can run off the screen but not the left row of pixels of the cursor. When you go to the bottom, the top row stops.",
"The actual cursor position is the single pixel on the tip of the arrow. It is always onscreen. But a single pixel would be hard to track visually, so an arrow icon appears below and to the right. That means that if the cursor is at the very bottom or very right of the screen, the arrow is outside the visible area."
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a7ba86 | During the late 80s to mid 90s, every home computer came with their own operating system. Now almost all home computers comes with just Windows, why? | Technology | explainlikeimfive | {
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"The short answer: because Microsoft, lead by Bill Gates, engaged in illegal anti-competitive actions to drive competitors out of business and establish a near-monopoly. They engaged in [wide-spread predatory business practices]( URL_4 ) designed to drive out direct and indirect competitors in the OS market. To give just a few examples: - Microsoft used their domination of the office suite market (Word and Excel) to sabotage their competitor DR DOS, by having their software detect when it was running under DR DOS and [falsely report that it wasn't compatible]( URL_0 ). - Microsoft used their growing monopoly power in the PC market to \"negotiate\" deals with PC manufacturers (\"agree to our terms, or we'll stop supporting your PC\") for what became effectively compulsory royalties. Royalties were tied to the number of PCs sold, not the number of Windows OS supplied. Consequently, if you bought a PC from a major brand they paid for Windows regardless of whether or not they actually supplied Windows. Of course they passed that cost on to you, the consumer, and **you still paid for Windows** even if it wasn't supplied. This [\"Microsoft tax\"]( URL_1 ) made it impossible for alternative OSes such as BeOS to compete even though they were much better and faster. - Microsoft partnered with IBM to develop OS/2 for servers, while secretly using the knowledge they gained to develop Windows NT as a direct competitor. Then, before OS/2 could be established in the server market, they dropped out of the partnership released NT, and used their domination of the PC market to likewise dominate the server market.^1 (Funnily enough, the early versions of OS/2 written by Microsoft were full of technical flaws which similar early versions of NT did not suffer from. It was only when IBM more or less re-wrote OS/2 themselves was it a decent server-class OS, but of course it was too late by then.) In the 1990s, the US Department of Justice [took action against Microsoft]( URL_3 ) and found that they had [acted illegally]( URL_2 ), but by the time Microsoft was found guilty, the US government under President Bush Jr lost its stomach for doing anything about it and merely gave them a slap on the wrist and made them promise to not do it again. But for a time, there was real talk about splitting Microsoft into two separate companies to break the monopoly. The longer answer would have to acknowledge the effect of non-predatory economic factors such as network effects (if all your friends used Windows, there are advantages for you to use Windows as well), piracy (software piracy helped MS DOS spread in the first place, and especially helped Excel and Word succeed against more established incumbents such as Lotus and WordPerfect), high costs of entry etc. The Dept of Justice findings of facts does a good job at explaining those as well. Nevertheless, the major reason that Microsoft dominates the OS market is that they illegally lied, cheated, sabotaged competitors and stifled innovation. We're still paying the price for that now, even though Microsoft appears to (mostly) no longer be acting in such ways, thanks to legal actions by both the US and EU threatening to break the company apart, plus the disruptive effects of the Internet. ^1 Microsoft never dominated the server market to the same degree they did the desktop. Unix and Unix-based OSes, especially Linux, continue to hold a large share of the market. But among the *DOS compatible* server market, Windows dominated.",
"When any sort of technology has multiple competing standards there is a tendency to converge on a single one. This is just the nature of the industry. Imagine being a software developer in the late 80's. You would have to write your software 4 or 5 times to have a good coverage of the marketplace. Now most software is written once, targeting Windows. That has benefits for the developer and the consumer because they get a broader software library available to them. Consumers notice when the system they use doesn't have much adoption across the industry because they will see that software they want to run isn't available on their computer. So, when they make their next purchase they will tend to pick the system that has the most software available for it. In operating systems this was MS-DOS and Windows.",
"Firs of all, the \"IBM compatible PC\", that is PCs which could run the same software from different manufactureres. That totally transformed the industry (to the better) and increased competition, suddenly the OS actually in practice could be made by whoever, instead of the hardware-maker (think of the non-compatible machines more like todays consoles). That paved they way for someone like MS. Who started off pretty well, and then used shitty practices to continue their domination. They are much more well behaved today, and get some of the same treatment in return from competitors in fields where they have become small.",
"Allow The Simpsons to explain: & #x200B; [ URL_0 ]( URL_0 )",
"The OSs before windows were much simpler and easier to code. OS/2 is perhaps the one listed that actually had a chance if IBM had been willing to develop it rather than go with windows. Before Windows, MS DOS was ubiquitous when you actually had to load the OS rather than have a simple system in ROM. It was considered complex because it had to actually handle floppy disk drives rather than cassette drive. When IBM came out with the PC and chose MS-DOS, the bit players were doomed. Compatibility and software availability was the key. Why recode for Atari, CPM or TRS-DOS when 95% of the market wants it for MS-DOS (and later windows). & #x200B; Note: I started programming in MS-Basic on a TRS-80. The OS in Rom was only BASIC with Cassette handling. When floppies came along they went to TRS-DOS but eventually Tandy went to MS-DOS as well. Businesses used Unix or CPM as they were the \"professional\" OSs apart from mainframes.",
"IBM started to use DOS in their \"personal computers\". Microsoft \"rented not sold\" DOS and the IBM model of personal computer was cloned and DOS went with it. The other computer companies used a form of basic that DOS drove from the market and many of these companies started to make IBM clones. Apple went its own way and had a brief \"cloning\" experiment but decided to keep all software and hardware in house at a later date.",
"TLDR: Developing operating systems (_especially_ modern OSes that do a lot of things) costs a lot of money and time and expertise. Keep in mind that the 3 major desktop OSes -- Windows, MacOS, and Linux -- these OSes are the products of literal decades of development by hundreds and thousands of developers. The overhead here is not small. Why would Acer develop their own OS when they can just license the work from someone else? Then there's the compatibility/cross-platform issue....",
"Also, Microsoft has agreements with major brands to keep windows flowing on new units. They want to keep their market share so they volume license for a cheaper price. Keep in mind back in the early 80's, Bill Gates gave commodore an open license to use microsoft basic on every commodore labeled product. That was the first and last time Bill Gates did that.",
"Today is very hard to say what is a home computer. If you think about PC, standalone desktop machine, then it is Windows, but you still have a choice to buy a MAC. Or to run a computer with Linux. In my opinion, the home computer can be a tablet or even your smartphone. Depends on your needs. But then we have an Android OS as a possibility. And Android has a quite good share in the market. Windows got that advantage with PnP standard. That was a crucial moment for Microsoft, in 1995. That made Windows flexible, practical, and turned out to be something that users really needed during the later developments of PnP interfaces. For more info Google \"Plug and Play\"."
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a7biv2 | How do vinyl records store sound, and how does a needle reproduce that sound? | I collect records yet I've never understood this basic question about them. I've read many explication but I've never found one that explains it plainly and completely. Thanks in advance everyone! | Technology | explainlikeimfive | {
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"Records are etched with very tiny physical bumps in the plastic. The needle is very delicate and when it runs over a bump, it vibrates. The bumps on the record are placed and sized very precisely to vibrate the needle at the exact pitch of the recorded sound (like how a vibrating glass makes a specific sound). The vibrating needle is too faint to hear, so the record player sends the vibration up the needle arm to be amplified in a speaker (the exact amplification process is where my knowledge fails). It's basically a very sophisticated music box.",
"Let's start with what sound is: a series of pressure changes in air. You generate those changes by moving a speaker cone forward and back to push air around. So you can picture measuring how much the speaker cone moves, and graphing it against time - you get a long, wavy line. Now take that line, and draw it on something, like a metal tape measure (let's pretend for the moment the tape measure isn't concave). Then cut the tape measure along that line, and now you've got that same wavy line as an actual physical thing. And if you were to run that wavy edge against the back of the speaker cone, you can see how it would move the speaker cone in exactly the same pattern that the speaker cone originally moved when you drew the graph. That's what a record does. It is a physical copy of an actual soundwave, and it literally vibrates a needle to turn that copy back into sound. It's how you had record players before you had electric amplification: the needle was physically connected to a diaphragm (sort of the \"speaker cone\"), which was at the base of the big horn (the \"amplifier\"). Nowadays, the engineering is much more sophisticated; the needle's vibrations turn into electric signals which can be sent to an electronic amplifier and processed further (or not) before being sent to the speakers, but the fundamental mechanism is the same."
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a7d4kg | With so much YouTube drama, it seems there would be a huge market for an alternative site. Why isn't there one? | Technology | explainlikeimfive | {
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"Twitch is branching off with features that support content creators who are searching for a alternative but that's all as far as i know. YouTube is just such a conglomerate that it controls the whole market around it.",
"It's incredibly expensive to run a site of Youtube's scope, and the site itself runs at a loss. It's much easier for other sites to specialize in one type of content than to try and become something that loses hundreds of millions of dollars a year. edit: Google doesn't provide actual numbers on how much Youtube itself makes or costs, but certainly in the early years when it was growing the site was running at a loss. Whether or not that's true now is anyone's guess, and you can find competing theories on either side. Regardless, getting to the capabilities and viewership of Youtube without the backdrop of a company with the resources or reach of Google is quite difficult.",
"There are other video sites. Dailymotion has been around nearly as long as Youtube. It even offers monetization like Youtube does. Vimeo caters to more film-like content but it's still an online video platform. Youtube is just the most popular. People can get upset about things that happen on Youtube all they want, but it doesn't mean much unless a large number of creators take their content elsewhere. I don't really see that happening any time soon unless something drastic happens.",
"A few have come and gone, some are still trying. But think of this videos have a huge storage and bandwidth requirement for streaming. You need advertisers or premium to pay. Who's going to buy add space for your 100 user site when YouTube has like 4 billion users? Which means generic ad-packs full of malware and Trojans. Congrats you just self nuked your own site by pissing off all 76 of you're users left ( the other 24 already left during the typing of this post cause the site is dead, and they are getting no views).",
"The fact is that YouTube is extraordinarily well run, regardless of the controversies. There are only a handful of companies on earth that can handle hundreds of hours of video being uploaded every minute, and the sheer volume of traffic.",
"No, there is a huge market for video creators who want a bigger share of the control and profits than YouTube offers. Alas, creators want to pay nothing upload their creations. Advertisers want to spend money to have people **watch video ads**, and that's what YouTube's great at. When your alternative wants to give advertisers less, they stay with YouTube. Plus, there is FaceBook - the land of freebooting. Unless your new solution prevents this, which seems unlikely without teaming with the evil that is FB, then more views are going to be in FaceBook's stolen streams than the ones you really serve for advertisers. I don't think there's a real market for an alternative. Too many problems and too much risk for investors. Maybe this argument needs to move to /r/changemyview .",
"Some of the key elements - **[The Network Effect]( URL_0 ):** Content is on Youtube, so users go to Youtube. Because users go to Youtube, content creators upload their content to Youtube. And for the same reason, advertisers (thus money) also go to Youtube. Same reason with Google+ ended up being a flop. As a results, content creators don't have much choice for platform that remunerates them (Twitch exists, but is mostly gaming and streaming, etc.) - **High costs** Creating the infrastructure at scale is very expensive for multiple reasons: video streaming is very costly by itself (storage, bandwidth), plus the heavy investment cost in anti-piracy systems, caching, etc. A?d that high is not just a base case that can be amortized alter on, it's a high recurring cost. It's also hard to get legal premium content (if you're small, large companies won't put their popular music/video on your platform - but users want those!), unless you give $$$. - **High risks** (See above) Such enterprise is unlikely to break through. Many new small players exist, but we don't even notice them (some other reached popularity in their niche -Twitch-, yet are far behind Youtube). Plus important legal risks if anyone can upload. - **Low revenue** Ads income is continually decreasing, people don't want recurring cost. Thus long ROI.",
"Most likely the same reason facebook still dominates the social media market despite its many flaws: people like to use what they are used to, and what other people use. Content producers prefer to upload videos to a site they know more people visit. Plus, there kinda are other sites, they're just not nearly as popular. Eg vimeo. Imagine phones could only communicate with phones of the same brand. People would likely almost all have the same brand. That's the situation with video sharing. We all go to youtube. Ironically, other sites are basically only popular _after_ they become popular.",
"The alternatives just are tiny compared to YouTube, like Floatplane. Youtube spends more money on servers than most of these smaller companies would make in their lifetime, and that is the main thing stopping a major competitor. Google has the money and resources to do it and that is the bottom line.",
"Because to become a YouTube you must: * Have thousands upon thousands of petabytes of video data. * Powerful enough computers to handle a petabyte worth of videos to upload *each day*. * Enough money to market your website. * Convince many people to use your site ONLY, as there would be no point for viewers to switch if the same videos are also available on YouTube. The ultimate solution to such an issue is (you guessed it) decentralization, where there is no central authority. Decentralization is **not** synonymous with a blockchain protocol. I believe the best approach to a decentralized YouTube is a self-hosted approach, much like how e-mail works."
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a7di2a | Why does the Google Play Store app require Google services to be installed as opposed to being installed with an .apk like any other app? | Technology | explainlikeimfive | {
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"It is to prevent phone manufacturers to add the Google Play Store and have it work without agreeing to Google's terms which include bundling some Google Apps with the phone.",
"Politics. You know how Microsoft had a monopoly over Operating Systems? All computers had Windows, and all computers came with Windows, and you couldn't buy a computer that wasn't running Windows... unless it was a Mac, in which case none of your programs would run? Well, Google's the new Microsoft. You don't remember that? Oh, wait, five. Gotcha. Well... I take it you've experienced bullying? Or seen it, or heard of it? Well, it's kind of like Google's a bully, and makes people who make phones install all of the Google apps on the phones they make, or nobody will buy their phone, or Google will sue them & ndash; that is, take all of their money away. If you're making a phone running Android, it's All Google or No Google, and Google have taught people not to buy phones without Google stuff so the phone makers don't have a choice. Google want to make sure that the phone makers don't have a choice, so they make sure that they can't install the Google Play Store app on the phones they make unless they're installing it _Google's way_."
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a7gtjt | What makes a product "Military Grade"? | Technology | explainlikeimfive | {
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"The IMPLICATION is that the product is supposed to be durable, but this is just marketing. Anyone who's served will tell you how funny they find that term -- we know that \"military grade\" actually means \"procured from the lowest bidder\" and is likely to break.",
"Military grade isn't a defined term. So it can mean anything. Mil Spec is actually a defined term and it's quality can be all over the place. Mil Spec is just the specification of a part. Depending on the requirements this can be either very high or very low.",
"It’s a PURE marketing term and has zero definitive meaning. Even within marketing, the term is completely inconsistent. Even the military has no idea what “military grade” means, because... it means nothing. Basically when something sales “military grade” it’s just a buzzword to sell you shit you because you think it has meaning.",
"If you make a knife it’s a knife. If the government (US in this instance) wants a better knife they use a publication titled Military Standard 961 (MIL-STD-961) to write / define an exacting specification for the knife. Then they have companies to bid and build that knife to those specifications. Those specs can be anything from what material, how long it’s expected to last, colorfastness, sharpness. Anything that was decided upon by the purchaser. That knife is now a MIL-SPEC knife. The assumption for marketing / selling such knives is that the standards of the military in construction or design make the product better (deadlier?) than a civilian version. But that may really not be the case. Just means it’s what the government needed. I’ve seen the spec for a microwave used on transportation aircraft. That microwave was MIL-SPEC."
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a7hbtz | How are music and audio recordings synced in the music videos? | Technology | explainlikeimfive | {
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"The finished audio recording of the song is played back on loudspeakers during filming. It’s loud, and there’s plenty of noise on set from foot steps, fans, directors comments, etc. The audio from the film is replaced by the officially released recording during post-production. Even if it wasn’t, video editors are advanced enough these days to be able to slide each clip forward or back to line it up with the music track, and then stretch or compress the length of the speed happens to be off. As an additional benefit, most music these days is recorded to a metronome (click track) at a known tempo, so everything should be performed in the video at the same speed."
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a7ijhk | how does an mri/ct scan see inflammation? | What is it about inflammation that makes it pop up on these scans? | Technology | explainlikeimfive | {
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"In contrast to what other replies have said, on a CT scan, blood has basically the same density as water and since most of our soft tissues are highly perfused with blood and our cells are full of water, most tissues look the same on a CT scan with the exception of air, fat and bone. A CT scanner isn’t the best at detecting inflammation because of those similarities but if you add IV contrast to the blood stream you can delineate things a little better. Still, at the end of the day, you can only sometimes detect inflammation in some tissues at some times. An MRI does not use xrays at all. It uses big magnets to alter the way your hydrogen atoms behave and as we know, hydrogen makes up a big part of our body, most obviously in all the water inside us (H2O) but also in fat. Different methods of detecting the behaviour of hydrogen atoms produce different images and a scan of your body often includes a number of different ‘weightings’ or ways of detecting the image which are all interpreted together to come up with a diagnosis. A lot of these ‘weightings’ have to do with detecting water in abnormal locations which is often diagnostic of inflammation."
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a7k486 | How does a vinyl wrap (e.g. for a car) wrap around the curves of the car so seamlessly without folding over itself? | Technology | explainlikeimfive | {
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"When they make the wrap it gets cut and scored so that it doesn't kink when it gets applied. Its also fairly stretchy so as they apply it they can stretch it to prevent bubbles and kinks. As they apply it they keep the sticky side wet so that it only actually sticks after they squeeze all the water out from under it and it is completely flat against the car.",
"I wrapped the dashboard of my wife’s Mini Cooper and needed to get it into vent recesses and around corners. You use a heat gun to soften the film which makes it very pliable. You just have to be careful to not overstretch it which can be caused when you heat it unevenly and it only stretches from one spot. When the film cools, its flexibility diminishes and its firmly attached. To remove it, you have to heat it again, otherwise it comes off in small pieces."
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a7l9dj | How do fast food places with multiple drive-thrus that merge into one keep track of who ordered what? | For example, you have Lane A and Lane B. In lane A, you have person C and person D. In lane B you have person E (myself) Person C orders first. Right after that person E (me) orders. Then person D orders. Logically, Person C then E then D should pull up. But person D cuts person E off. How does this not mix the orders up? | Technology | explainlikeimfive | {
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"They take a picture of your car, then it’s attached to your order on the screen at the first window where you pay. Then the order you pay in is the order your second window is given so they give you the right food.",
"Chic-filet has this system and they get around it by taking everyone's name and attach it to their order. I got up to the window and they asked me if I was \"Person A\", I said no and said I was \" Person B\" and so they simply told whoever was putting the meals together that they needed Person B's meal."
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a7lyox | why do some letters like "a" or "g" look different on a computer than when normally written? | Technology | explainlikeimfive | {
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"A number of reasons, some of which go back hundreds of years. More or less in chronological order, they are: \\- Legibility: Handwriting conventions are a compromise between readability and the mechanics of the human hand. While any human can conceivably fashion highly readable letters similar (or even identical) to those used in printing, it is impractical for most people to do so, and so how we're taught to draw letters is usually a convention based on compromise. But printed letters are not limited by human needs, and can be absolutely anything. There are millions of typefaces in the world, but they fall into broad categories, and most are devised to be easy to read, using long-established practices found to help with that. Printed letters are generally more readable because they **can** be, and follow forms that are known to help with that but which are harder or slower for most humans to draw clearly and reliably, such as the \"a\" and \"g\" glyphs you refer to. \\- Legacy: Once these conventions were established, they became standard for nearly all typography, starting a very long time ago. Many other factors have influenced their specific design since, and many of those results also became legacy conventions. \\- Efficiency: Automation in typography required strict standardization of form. When you've invested in a huge expensive machine like a Linotype, you're pretty much bound to one typeface, and it better be one that's versatile enough to handle a wide range of content. Longstanding typographic conventions developed over many years of movable-type printing helped to establish these conventions. Consideration such as how a letter may look if it's over-exposed or over-inked on a certain kind of paper influenced these designs, and the specific glyphs that became standard were those found to most reliably serve the goal of legibility under the widest range of conditions. The double-loop lower-case \"g\" glyph has a shape that is recognizable even when malprinted. \\- Efficiency, again: When printing moved to digital, the shapes we knew were instead approximated with dots in a matrix, and there was a memory cost that had to to be accounted for. It was important that characters not 'cost' too much. Simplification of form helped make data-processing more efficient, at a time when RAM was counted in kilobytes (instead of today's gigabytes) and CPU speed was counted in kHz. \\- Legacy, again: Today's computers inherit the conventions of earlier ones, even though they're much faster and more efficient, and that includes many of the small changes made to glyphs during the metal-to-digital transition of half a century ago. This isn't due to laziness, but because they glyphs we have work well, and always have, so there's no special need to change them. \\- Where do we go from here? There is much room for improvement in the digital-to-paper transfer that still constitutes the vast bulk of professional and commercial printing. Permanent legal documents may involve thousands, millions, or even billions of dollars, or other assets that are great in some way (huge tracts of land, for example), and therefore readability remains a very important goal. Yet a great deal of this important documentation is poorly printed and not as readable as it should be. There's a market there for someone who wants to research the path that a character takes from original conception to digital composition to final impression on different kinds, sizes, and formats of paper, to figure out which will work best and most reliably. (Not just glyphs, either, but the dicey DPI-to-LPI transition, relative image density, and more.) Newspapers and magazines made a huge investment in that in the past, because they would find out right away if there was a problem when complaints came in. Today's professionals don't have that immediate feedback, and so are not making the same effort, and that risks a growing number of situations where those who created some text might not be around to explain it when someone else can't read it down the road. Proactive research would help prevent that.",
"Depends on the font. For example: 𝒂 𝒈 versus 𝗮 𝗴 And, in actually writing, you'll find both of the above used variously over history. But humans trend toward the simple and easy, which the ~~former~~ one of those is, so most people write like it like that today.",
"A lot of people write in the cursive handwriting. The letters on a computer are not in cursive writing, that is until you change the font ofcourse. Another reason would be, as u/glyttch posted in another thread, > Partly because of old printing presses with handset type. The lettering used on old presses could become worn, making that a look like an o, or vice versa. By using the a we know in common typefaces today readers could easily distinguish between an actual a and a worn o. Also, α actually is lowercase Α in Greek.",
"Because hand written letters take time and effort. When writing a lot, people tend to use simple, short lines to record their letters as quickly as possible. Computers and printing machines use the same amount of time to display a super-fancy letter as a super-simple one.",
"One of the reasons is for legibility, especially with the ‘a’. The handwritten ‘a’ can often look like an ‘o’ at first glance. Edit: see futura for an example URL_0",
"When we go back to old printing presses, the way \"a\" is written in hand looks a lot like an \"o.\" As the letters wore down, it would be hard to distinguish an \"a\" from and \"o\" and a \"g\" from a \"q\" depending on where the wear happens. I believe our current typefaces are anachronistic for this reason.",
"One thing thing that I can add to the answers here is a bit of history. Just prior to the invention of the printing press, there were two main formal styles of writing, [Humanist]( URL_1 ) which uses the \"computer\" a and g, and [Italic]( URL_0 )(predating the modern \"slanted text\" meaning, it just means \"Italian\" here) which uses the \"normal\" a and g. Humanist was chosen for printing as the letters are upright and fit neatly into rectangles. Italic however wrote letters at a slant so they didn't fit into rectangles, but it was very rhythmic and fast making it easy to adapt into a cursive script for handwriting. As handwriting developed, the Italic a and g stuck. Likewise, as typography developed, the Humanist a and g stuck."
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a7naa0 | Is therea difference between a "3.5ghz cpu" and a "2.6ghz cpu but with turbo boost up to 3.5"? | Technology | explainlikeimfive | {
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"Turbo boost is a marketing term for dynamic clock speed in CPUs. Intel chips equipped with the technology normally operate a certain speed but can dynamically increase to the Turbo-boost speed when under load. The reason the chips can't operate at this speed all the time is because the heat they generate can damage the chip and because of high power consumption. In a laptop for instance this is to your advantage as the lower resting frequency reduces power consumption + heat which increases the battery life. The technology gives you more top-end speed when you need it. Rather than paying more for a CPU with a fixed higher clock speed that you might not actually require for what you are doing. Reference: URL_0"
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a7nar7 | How does credit card skimming work? | Technology | explainlikeimfive | {
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"It's essentially a \"man in the middle\" attack. Normally when you swipe your card the machine reads it, and transmits your info. To setup a skim the criminal inserts a special machine into the reader, which also looks like a reader so you won't notice. You swipe your card, the skimming device reads and stores your info, and also immediately passes on into the actual reader so that your transaction completes as normal. In actual five year old terms. When you swipe your card you're just telling your number to a nice security guard (the card reader). To setup a skim, I also dress up as a security guard and stand right in front of the actual guard. You tell me your number, and I write it down and immediately turn around and tell it to the real guard. You get what you want, and I get a copy of your credit card info, with no one noticing.",
"Your credit card has a bunch of information encoded into a magnetic strip, your account number, your bank information, expiration date, etc. When you swipe your credit card, the machine contacts the bank, verifies that the account is real, and you have sufficient available funds, and, assuming you're approved, logs a payment request. And that's it, it promptly forgets about you. There's really not a whole lot of reason for the retailer to remember that information, because there's no guarantee that you will ever shop there again, and even if you are a regular, they would still have to verify funds every time. A card skimmer is a more nefarious version of the same credit card machine. When it reads the card, it takes all that information and sends it to someone, or stores it for later retrieval. The thief now has all of the important information to make a fraudulent purchase. They can either reproduce that magnetic strip, and make their own version of your card, go on an online shopping spree, or if their not interested in that, they can sell the info to someone else who might be."
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a7pa4r | Excited for the SpaceX and Blue Origin rocket launches, but what's the actual purpose for this series of launches? Are they just launching and landing immediately for the sake of testing? | Technology | explainlikeimfive | {
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"SpaceX have been contracted by the US Air Force to launch 10 new GPS satellites into orbit. The first of these satellites are now sitting on the pad on top of a Falcon 9 rocket ready to launch into orbit. This is a fully operational flight with the main objective being to get the satellite into orbit. They are not even going to try to land the booster to reuse it like they have done in previous launches. & #x200B; Blue Origin have also been contracted by NASA to fly several different experiments on a suborbital trajectory. The New Shepard is cheaper for NASA then a fully orbital capable rocket would have been so this allows them to conduct experiments that are looking at the launch conditions and the long period of weightlessness much cheaper then if they would have used a full rocket like the Falcon 9. The landing of the capsule is to be able to retrieve the experiments to do further analysis of them. The booster is also landed and reused to make the launch cheaper. In addition to this it is quite likely that Blue Origin have made changes based on the experience of the previous flights and wants to test how these changes affects the vehicle in flight. They will also subject the vehicle to slightly different conditions then previous launches which means they might discover new issues that they previously missed. This is all to help them improve their design so that they hopefully are able to build a safe and cheap rocket which can take humans to the edge of space and safely return them to the surface of the Earth.",
"To answer your question simply, yes. Each of their tests have specific objectives, all going towards making sure that all systems are 100% working before the launch of the actual payload that they have been contracted to launch. ELI5 version: you don't want to be launching a $300 million satellite into the ocean and losing potentially a $5 billion dollar contract because you 'didn't want to spend a few million on test launches' & #x200B;"
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a7q3cy | How are telephone numbers assigned when you purchase a new cell phone? | I'm a bit of a Luddite; I only recently got a cell phone and my husband was the one who purchased it and took care of all the details involved. I read a story online a few years ago when someone purchased a cell phone (circa 2003) and the number she was assigned used to belong to a celebrity, so she received some calls from "industry" folks who had not been given the celeb's new number. I found an article from 2006 that mentions that some service providers recycle old phone numbers, but that was 12 years ago. Is there a finite number of available numbers, and do service providers still (unintentionally or otherwise) recycle numbers? Do they have some sort of database that shows current numbers available, and how in the world can they keep up to date with such a constantly changing factor? & #x200B; \[\[Not to belabor a point, but I remember back in the early 1990s when the area code in my particular suburb was changed twice within a three-year period because of the high demand for telephone numbers - at that time, it was due to fax machines, pagers and "car phones" (as we called cell phones at that time). There were dire predictions at the time that we might have to expand to an 11 or 12-digit system for telephone numbers if that demand continued. Fax machines and pagers aren't as prevalent, but certainly the abundance of cell phones has made up the difference. Yet we still use a 10-digit (not counting the '1' prefix) system. That's why I'm guessing that number do get recycled somehow...\]\] | Technology | explainlikeimfive | {
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"Yep, there are a finite number of telephone numbers (after all, there are only so many ways you can combine 10 digits, and a bunch of those combinations aren't actually allowed as phone numbers), and numbers are recycled regularly. Each telephone carrier gets blocks of phone numbers allocated to them 1,000 at a time, with all the numbers sharing the first seven digits (the three digit area code, the three digit exchange prefix, and the first digit of the line number). The carriers know which numbers that they've been allocated are in use (because they have assigned them to a customer's phone) and which ones are free, since they have to route calls to the right place when someone dials the number. So when you go to sign up for service, the service person looks up which numbers are free and assigns one to your account. Depending on which carrier and how nice the service person is, they may give you a choice of several available numbers, or they may just assign the first one that's available. If you ever cancel your service, that number returns to the pool of available numbers after a period of time."
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a7r5z6 | How do IT workers (sorry for the generic term) “see” a user’s web traffic? If I accidentally click a NSFW link using Apollo while connected to my jobs wifi, can they see that? | Technology | explainlikeimfive | {
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"So, there are two answers. First, yes - they can see that. They very likely can't actually see what is at the link unless they go there (most web traffic is encrypted these days, including Apollo's, AFAIK), but they can see the plaintext address. Which means they can follow the link to see what it was you clicked on. The second answer is one of IT's big secrets: we aren't looking. No one has time to monitor logs and check to see if content is inappropriate. We just throw some filters in place (most of the time just a vendor-provided list, but sometimes carefully tailored) and call it a day; we're already trying to cram sixty hours of work into a fifty hour week. *Unless*, of course, we're requested to investigate something about you specifically. The data is all there, so we can provide it. Which means you can 100% get away with browsing porn at work if it's hosted somewhere not on the blacklist...but don't, because that will make firing you for cause super easy if some manager gets a bug up his ass about you for some reason.",
"When you are on somebody else's WIFI you should always assume they can see everything you're doing. But typically they only see what websites are accessed not the content of the website, even then that's only if they're actually looking. At my work there's almost a thousand people and majority of them probably have their phones hooked up to wifi so to somebody looking at the log of sites accessed its be a big ass log. Itd mostly be a computer program monitoring it. But back to my first point, regardless of what does or does not happen if you're not on your own WIFI you should always assume you have zero privacy.",
"I'd assume that Apollo uses HTTPS, this means they can see the URL you're requesting but not much more - the rest is all end-to-end encrypted.",
"All of your traffic is routed through your company's hardware, and that hardware has logs (there are likely software logs somewhere, too, but let's just keep this simple). These logs can identify which machine the request came from from and where it was going to. Visiting a website is a very simple HTTP request called a \"GET\" - it contains no data, other than saying that you are requesting a website. If I send a \"get\" request to URL_0 from my web browser, it sends me back the google homepage. An IT worker can see that in the logs."
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a7t7ki | why do airlines insist on having dual-type headphone jacks? | It doesn’t seem to make sense these days with most people carrying their own headphones. What is the benefit of having the dual-type jacks? Is it so people don’t steal the complimentary headphones? | Technology | explainlikeimfive | {
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"Some people suspect it's a vestigial choice based on when airlines used air-pressure type headsets instead of electrical. They had 2 tubes one for left and one for right in the seat that you would plug a headset into. URL_0 The most likely reason for using 2 jacks instead of a stereo jack was that when they were first introduced the airlines rented the headsets for the flight. Personal headphones weren't common place or cheap yet so it was probably to prevent people from stealing the headphones.",
"You used to have to rent headphones. The dual prong was to force this. Then Chinese manufacturers began making adapters and the airlines switched to complimentary headsets. Not worth the cost of re-wiring the seats."
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a7uj20 | How does a computer (running a modern operating system) boot up? | What happens between pressing the power button and being able to use a fully functioning operating system? | Technology | explainlikeimfive | {
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"It does a POST which is a check of the very basics of the computer. If you fire up an oldie you get to see it, usually just white plain letters on a black screen as it counts how much RAM it has available and checks what the processor is and such. In a modern computer if it POSTs it's so quick you usually don't even see it. Then there is a setting in BIOS, the \"basic input output system\" which is the software behind running the bare bones basics like POST on where to look for a program to start, such as a setting saying \"hey look in the C: drive.\" It looks in the C drive and sees Windows and starts its bootstrapper. The Windows bootstrapper takes over and starts up all the programs it needs to run the full Windows OS (unless you boot in safe mode, which boots just the minimum needed to actually operate).",
"When the computer powers on a timer holds the processor in the reset state. This allows the power and chips to stabilize to a known state. The reset state is usually related to the reset button some computers are outfitted with. When reset drops the CPU is hardwired to start at a specific memory address. The BIOS start is placed at that address so it starts running. The BIOS performs many internal checks including hardware detection. The BIOS starts the display and keyboard to interact with the user. The BIOS doesn't do anything that a user would want so it hunts for bootable drives. Drives are a permanent storage for any kind of operating system the user wants. The BIOS picks a particular bootable device according to rules set by the user then loads and runs the first sector on it. The installed operating system has placed its first startup code on the first sector. The BIOS is now out of the picture. The OS startup runs everthing now. The OS is a series of load and run actions. Each action loads successively larger and more capable code. The first sector is only 512 bytes so the code is too small to read file systems. It can read sectors by number so it loads and runs a fixed set of sectors as instructed by the installer. This much larger code can read file systems. It loads the OS boot image from the file system and runs it. The OS boot image knows how to run every part of the computer and this part of the boot is no longer ELI5 simple. Generally it goes like this. Detect and load drivers for all hardware. All hardware is set up and in the best and fastest modes, not just the few pieces that were needed to boot and in the slowest and simplest modes possible. In particular the sector loading code is switched from the slow and crude boot code over to the OS fast disk driver code. The OS creates a user space and loads into it a startup script that loads everything needed for a modern desktop."
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a7vy6a | what's the difference between a router and a modem | Technology | explainlikeimfive | {
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"A modem converts data flows between two different physical media, typically between coax cable and Ethernet twisted pair. A router looks at the data and decides if the data needs to move from one place to another in order for two or more systems to communicate with one another. So if you try to pull up a web page from the Internet using your browser at home, your router will know that the request needs to leave your home. Once the router tries to send the request outside of your home, it will copy the request from your WiFi to the Ethernet cable that connects to your modem. Then the modem will copy the request from the Ethernet cable coming from your router to the coax cable that connects the modem to your wall outlet. As data flows back and forth between your home and the Internet, sometimes it will be copied as is between different transport media and and other times some data will be changed so that it can find its way between your devices at home and whatever they're talking to on the Internet."
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a7x50f | What is the difference between white box and black box testing? | Technology | explainlikeimfive | {
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"Black box describes a device which you can view its inputs and outputs, but not its internal workings. Therefore black box testing means testing something only by feeding it various inputs and then analysing the outputs. For example, black box testing a website works by sending it various requests and analysing the responses. This way you are testing the product the way that an actual user uses it. White box testing is when you have access to the internals of the software. You can look at the actual source code, you can test individual components, etc.",
"White box testing tests internal structure of something, black box testing tests the outcome. Example: A machine that gives you back the number you put in, if you put in 9374, it'll give you 9374. In black box testing you are happy as long as it gives you back 9374, it doesn't matter what it's doing inside, it could be adding 100000 to your number then subtracting 100000, in white box testing you will see that this is inefficient or redundant and maybe remove the parts that add and subtract."
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a7yhej | tried posting on r/askscience but it kept getting removed... Today I read"Biohacker injects himself with DNA sequence made from Bible and Koran verses"how is this possible? | Technology | explainlikeimfive | {
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"> how is this possible to do outside of a well equipped lab He didn't do it outside of a lab. Right from your own article: > The student then built the proteins **in a lab** before injecting himself Emphasis mine. > and how do you go about arranging dna into words He didn't arrange DNA into words, he arranged words into DNA. His own report is linked in the article which describes his method. Basically he eliminated all spaces and punctuation, leaving behind letters. He then assigned each letter to one of the four DNA nucleotides (adenine, guanine, cytosine, and thymaine). He then used his laboratory equipment to construct proteins using this information and injected it into his body. > and what are some possible unintended side effects from very minor to catastrophic Infection. Death. Some sort of unintended auto-immune response."
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a807qn | Why do drive up ATMs have Braille? | Technology | explainlikeimfive | {
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"The buttons are mass produced, it doesn't make any sense to produce a different mold, different production runs, and a different product line just to save material from some bumps. They just use the same buttons that would be in a pedestrian ATM and don't worry about it.",
"they probably just use the same mass produced ATMs that are on street corners. It doesn't make much sense to make special braille free ATMs for a select few cases. Plus, the blind person could be in the back seat and therefore not driving and still use the ATM.",
"Federal regulations require every ATM to have braille. The ADA Accessibility Guidelines for Buildings and Facilities specifically. And blind people use driveup ATMs all the time apparently, After all they can use it from Taxis, Ubers and such, or even from a friends car in the back seat.",
"ATM producers make keypads with Braille dots for their walk-up machines anyway, so it makes financial sense to produce them all in a uniform fashion. Also, a sighted driver might have a blind passenger that needs to use the ATM (they’d just sit behind the driver & the driver would pull up slightly).",
"I don’t know if this is the official reason, but off the top of my head, sometimes blind people need to use ATM’s, so they have a friend or relative drive them through the drive through, roll down their window, and then use the Braille to select the right buttons. Those sort of ATMs also have headphone inputs sometimes, so the customer can hear the questions before choosing an answer. Maybe someone more knowledgeable on the subject can fill in the rest for me if I missed anything?"
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a8392j | How does a business router handle internal traffic better than a consumer one ? | So this question comes up a lot at work, I've tried explaining that consumer routers are designed for fast upload and download, but find it hard to explain why they don't work so well for internal traffic. Does anyone have a good simple explanation ? | Technology | explainlikeimfive | {
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"Business routers usually have a great deal more customization than consumer grade routers do. Consumer routers are designed to plug and play, with minimal things that you can screw up. Businesses usually need more flexibility. For example, I run a business grade router at my home. It has allowed me to set up multiple virtual LANs (VLans) so my wireless access points can broadcast multiple networks for different devices (main network, IOT devices, guest access, etc.) Those different networks have different firewall rules to allow some traffic to pass, but others not (my main network can talk to my IOT network devices, but not the other way around) and limit internet access (main and guest networks can access the internet, IOT can not). They also tend to by highly modular so businesses can customize to their needs. Your home \"router\" is actually a combination device - a router (to direct traffic), a switch (to connect Ethernet devices), and an access point (to broadcast wifi). Business grade devices tend to be just one, so you buy three devices that do exactly what you need them to do."
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a85e0s | What does a cpu core do when no program is using it? | Normally one core is noticeably higher than the rest cause it is handling windows and maybe some background processes. But all other cores are also being uses, very minimally, but something is happening. Just curious as to what a core does when not in use by a program or the OS. | Technology | explainlikeimfive | {
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"text": [
"Unused cores are \"idling\". They are basically doing nothing (actually doing \"NOOP\"=\"no-operation\" commands every cycle, afaik) while waiting for some work to arrive. Modern CPUs are often able to underclock them on the fly, i.e. run idle cores at lower speeds, which preserves energy and helps with cooling."
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7
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a865u2 | Why did it used to be mandatory to add “www” in front of a web address for it to pull up correctly, but now it’s optional? | When I was younger, it used to be that if you didn’t type “www” in front of a web address, the page wouldn’t load properly, but now it’s optional. I’ve read that the “www” part has to do with the webpage’s server, but servers are all different, and it used to be like...a collective thing? So does that mean people used add “www” for a specific reason and now that reason is obsolete, or was it always sort of unnecessary? | Technology | explainlikeimfive | {
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"Some websites started pointing URL_0 to their website to make it easier and it just kinda caught on. You would think that teaching people that you have to go to WWW. to get to the website would be easy enough, but you would be mistaken. Even a concept as simple as how the DNS works still confuses people to this day. I can't even get my mother to understand the difference between the address bar and Bing search. The DNS was designed with sub domains in mind. You had to have a prefix like WWW or FTP to define what the service was, and that was in turn tied to an IP address. Technically though it was never required, you could point URL_0 to your website directly if you wanted. That kinda broke the rules but no one followed them anyway. By the rules you aren't supposed to use .org unless you're a not for profit, .net is for networks, and .com for commercial. But no one really follows these rules because they were never enforced in the first place.",
"I don’t think the www was ever required, it’s just a convention. (Maybe I’m wrong, someone correct me). The system behind this is called DNS. Today, at least, it works like this: . com - TLD (top level domain) URL_1 - domain name URL_0 - sub-domain name URL_2 - as many sub-sub domain names as you want Each combination in total is called a fully qualified domain name and has an entry in a DNS table which is a pointer to an IP address or another FQDN, and there are some other kinds of DNS records that you probably don’t need to worry about. So, let’s say I’m google and my web server’s IP address is 1.2.3.4 I can make entries in my dns table like URL_1 1.2.3.4 URL_0 1.2.3.4 Now if you browse to either www or not, you get taken to the same server so it doesn’t matter which one you use. Most companies set their dns up that way but some still don’t.",
"Traditionally, your webserver was named \"www\", your mail servers \"mail\", etc. As the web part of the internet took off, people started redirecting their domain root addresses to their www servers to simplify web urls. Most domains say something like \"for web traffic coming to URL_0 , send it to the ip address for www. URL_0 \", or they will assign \" URL_0 \" the ip address of the webserver directly.",
"www. is actually just a subdomain, like URL_1 or URL_0 . When setting up a site host file on a server, you specify the server name ( URL_2 ) and you can add server aliases (in this case www. is the common subdomain alias, but can also be a wildcard \\*. URL_2 which will accept any subdomain and point it to the same website). When setting up the DNS record, you actually point the base domain ( URL_2 ) to the server ip address AND at least the www. subdomain to the same ip address. As long as the site host and the dns records are both set to handle www. then www. URL_2 will work just like URL_2 - I've been known to forget to add the server alias to site host files and then get complaints that www. isn't working. Also, in the host file, you can set a url rewrite rule that basically says, \"if you entered www. URL_2 just redirect to URL_2 \""
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a884iv | why aren't there multiple versions of the Internet run by different tech companies? | Technology | explainlikeimfive | {
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"The internet is just millions of computers connected to each other. It's not actually run by anyone, and too widely diffuse to be controlled by one company. Although Google's search function dominance comes closest.",
"It's theoretically possible to do that. A big company like Google could spend billions of dollars building their own infrastructure across the world to make a separate Internet. But then they have to convince both consumers and companies to switch over to using their Internet. But why would anyone do that when it's inevitably going to have less stuff on it, at least at first? To make it more useful chances are someone would provide a service allowing you to access the regular Internet from the Google Internet. And if someone does that, well now it's just one big Internet really.",
"There are. Here is what the Internet is: is is not a single system of networked computers, but actually the \"inter-netting\" of different systems. So you can imagine that all kinds of people run all kinds of systems and computers and what we consider \"the internet\" is just a bunch of standards we agreed to so all those computers and nets can talk to each other. Imagine a company having an internal system that's technically the same as one of their public ones, but since it is not \"inter netted\" and accesible from your computer via the \"inter net\" protocols, we do not consider it the internet. --- Now, that was a literal answer to your question but not the answer to your question you asked. In the earlier times of the internet there *were* different internet-like systems that were isolated from each other. There were large companies that provided access to the normal internet as we cosinder it today, but *also* access to a company-owned smaller, more controlled version. CompuServe and AOL were providers, online portals and content providers that set up their own, very isolated net for their customers. We do not do it that way anymore because it was in the end very impractical and people went from the company-owned offers back to ones in the \"normal\" internet that were better - or just let them connect to other people not with, say, AOL. All that said: given how the current tech develops we're going to see more non-internet internets. For example China is pretty much on their way to creating an isolated China-net. But I am certain one of the large tech-trends in the next 20 years will be some large network by one company that offers its customers \"what they need\". I am fairly certain there were a lot of people for in the last years for whom \"Facebook\" was basically all the internet offered, sure, they *could* have gotten out. But for many people there was little need to do so (with Friends, information, and games all being readily available on just that platform). With Facebook dissolving we're going to see a step back in that trend, just with \"The Next Big Company\" that replaces Facebook (or its replacement) offering people \"all they need from one hand\".",
"There were services like this - AOL, or Compuserve, for example, used to be like this. However once the open web became more popular these services died out as being more expensive and more restrictive than the web.",
"In the beginning there were several proto-internets that worked like this, only instead of being corporate, they were government and academic. There were services like the French Minitel, NIPRNet, SIPRNet, and individual university networks. The problem was that with so many disparate systems, it became difficult to transfer data between systems if they ran on incompatible codes or weren’t supported by a connection between the services. You would need nodes and hubs of operators changing over the data in exchanges like with old-timey telephone or telegraph systems, and would ultimately be a technological backslide compared to the current internet.",
"I think there are, in the form of various organizational intranetworks and in the patchwork 'ownership' system that we use to build and maintain the internet and our data infrastructure.",
"In this context, think of the internet as roads that lead to shops, etc which are websites. You can have your own roadways, but you have to build shops for your roads or separate roads to the existing shops or the simpler option of connecting your roads to the existing roads and we are back to having only one set of roads i.e only one internet."
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a8a3if | Why did switching back and forth between channels help make that one naughty channel come in clearer as a kid? | Technology | explainlikeimfive | {
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"text": [
"Because on old cable devices when you changed to a pornography channel It would take it a second to check and see if you were a paid subscriber. In that time while the machine was checking for verification the channel would come in clear but then scramble once they found out that you were not a paid subscriber. If you went back and forth you could get a couple minutes of clear picture out of every hour of channel changing. In a world before the internet, for some people, this was worth the time."
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a8bgir | How does a music box work? (My 5 year old just asked me, and I realized I actually have no idea) | Technology | explainlikeimfive | {
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"text": [
"Inside the box there is a comb of tiny tuning forks. When plucked, each fork makes a single note. There is a drum and there are many spikes on the drum. When the drum turns, usually by a clockwork mechanism you wind, the spikes pluck the forks. The spikes are arranged in the order of the tune, and so they pluck the fork that makes the right note to play the tune."
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a8br1p | If visible light is just a small part of the electromagnetic spectrum, can we build a camera that can "see" other frequencies on the spectrum, e.g. so we can see where certain frequencies are being transmitted from? | Technology | explainlikeimfive | {
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"text": [
"We can and do. This is exactly what radar, thermal imaging cameras, UV cameras, and X-ray detectors do. Space probes and telescopes are often mounted with cameras that are looking for things other than visible light",
"We do! [Here’s]( URL_1 ) some images of the sun at different wavelengths, for example. And since bees can see ultraviolet light, often flowers have patterns that reflect it, so it’s always fun seeing [images that’ve shone UV on them]( URL_0 )."
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"https://m.huffpost.com/us/entry/us_58f4ff14e4b0b9e9848d7da6?ec_carp=6712299302539243453",
"http://coolcosmos.ipac.caltech.edu/cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/sun.html"
]
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a8bvcw | Does Google have to pay to advertise the Pixel 3 on YouTube? | Technology | explainlikeimfive | {
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"text": [
"I have no specific knowledge about this specific example, but usually large companies that have divisions like that (like a company that makes products but also owns a magazine, etc) will not have to pay “per se” but have to track accounting and maybe move internal budgets around. Say Acme makes toys and also owns a children TV channel. One division has a budget for making toys and advertising and gets revenues from sale. The other has a budget for making TV shows and sells ads for revenue. So the toy division could use some of its advertising budget on the other divisions TV channel, because it’s using up ad time that external companies could be using and paying for otherwise. It’ll be internal transfers usually but fully accounted for. Another option is revenue sharing. But it’s never “free”",
"Depends on your definition of \"pay\". Large corporations like Google will have internal accounting practices where one business unit (Android) will \"pay\" another business unit (YouTube) from their budgets. So, the Android team will take some of their marketing budget and transfer it to the YouTube team who will record it as revenue. All of the money stays inside the company but there are records for the transaction. They do this to account for the lost opportunity to sell ad space to external advertisers (opportunity cost) and to prevent internal departments from just demanding as much advertising space as they want."
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a8bw9a | Is the Moon a better launching base than the Earth for space exploration? | Technology | explainlikeimfive | {
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"text": [
"Yes, for the reasons you say. However, the problem for that is that the entire space program is located on the Earth, and you have to bring an awful lot to the moon before you can launch from there. So for the foreseeable future, we're going to be launching from the surface of the Earth.",
"All those are benefits, but there is a major detriment: All our stuff is here on Earth. In order to get it to the moon we would need to launch from Earth anyways which means the question is only when it happens. The only way you could benefit is if you made stuff on the moon from materials found there. That limits what you can do because huge facilities don't exist to replicate industries such as on Earth already."
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a8e2ru | How do touchscreens work? And why do some surfaces work while others do not? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"There are two basic kinds of touch screens. Resistive and capacitive. Resistive detect pressure and so you can use almost anything to interact with them but they can usually only detect a single touch at a time. Capacitive screens are what is used in almost every smartphone and tablet you've used in the past 10 years and this detects the electrical charge potential of your skin. These can detect many more points and don't require any pressure, simply contact. But, they don't work with objects that don't store electrical charge. So, a plastic stylus won't work but a rubber one would.",
"There are several ways to make touch screens work. The two major ways are pressure and capacitance. Pressure sensitive touchscreens work exactly how you think they do. You push on them and sensors detect where this pressure is. These are great because they are simple and don't require special materials. They can also work with anything that can impart pressure. Pen? Works. Pencil? Works. Finger? Duh, works. String? Sorry no works. The other way is the one your are probably most familiar with. Capacitance. This works because your skin is conductive (you can pass electricity through it). But it is a very small amount of electricity so you can't feel it. Basically the screen is covered with a bunch of tiny capacitors. When you touch the screen it takes a little bit of electrical charge from that spot. The phone is smart enough to detect this and knows you are touching it. This method requires special materials so that's why you need special touch pens and gloves to use them with something other than your finger."
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a8e37t | How exactly does the “Year 2038 Problem” pose a threat to us in the future? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"A lot of computers count time as \"How many seconds has it been since midnight of January 1st, 1970?\" and store that number in a piece of data that can only count up to about 2 billion. The issue occurs when we end up at a time frame that's beyond 2 billion seconds after January 1st, 1970. & #x200B; Computers with the 2038 problem store time in 32 1's and 0's. The first \"byte\" is a 0 if you want time after 1970 and a \"1\" if you want time before 1970. So 10000000 00000000 00000000 00000100 translates to \"4 seconds before 1970's new year.\" & #x200B; The 2038 problem happens when you fill up those 31 binary numbers with 1's. & #x200B; The highest time you can store after 1970 is & #x200B; 01111111 11111111 11111111 11111111 & #x200B; When you try to add another 1 to it you get & #x200B; 10000000 00000000 00000000 00000000 & #x200B; which represents \"zero seconds BEFORE 1970\" then you start counting backwards since the negative operator is now flipped."
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a8enp6 | How do headless guitars and basses work and why would you want one over a regular model? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"On a normal guitar, string tension (i.e. string pitch) is controlled via tuning pegs located on the head of the guitar. A headless guitar removes the head entirely, and the strings are attached at a fixed point where the neck ends. String tension is instead controlled by adjustable bits located on the body. The advantages of a headless guitar are apparently a matter of preference, but some people prefer the lighter construction and different center of gravity. The lack of a head also simplifies the structural design of the neck and body and allows lighter materials to be used, which creates a distinctive sound."
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|
a8gnyb | How do applications such as Steam allocate space in a hard drive without downloading anything? | So I bought R6S and the game file size is 70.1 Gigabytes. It took 6-7 minutes to just "Allocate disk space" when I went over to the file where the game would be downloaded upon clicking on the folder and right clicking it the folder comes up at 0 bytes. So how do applications allocate space in a hard drive before even downloading it? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Steam is simply reserving a certain ammount of space on the hard drive so it knows it has enough space to store the files when they download and to make sure no other applications fill the space during the download. It also helps keep fragmentation to a minimum when downloading multiple games at once."
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a8h2r0 | What does each browser extension (.com, .gov, .edu, etc.) do? Does it make a difference? How/when did they come about? | Technology | explainlikeimfive | {
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"traditionally .com was commercial. .org was non profit or some other organization. .net was network related site. .edu was educational. .gov was government website. some of these are reserved like .edu .gov but the others are fair game today. and they are coming up with increasing numbers of top level domain names every year.",
"Once upon a time, the idea of the Internet was to section everything in organized boxes. So to begin you'd have categories. Like commercial business, government organization, educational, an actual network provider, and so on. So the first boxes to be purposed were: * com for commercial * gov for governments * net for network operators * edu for education * mil for the military * org for pretty much everything else that didn't fit the above. And you can see a lot of that still in action. Like the following... [ URL_47 ]( URL_22 ), [ URL_36 ]( URL_20 ), [ URL_30 ]( URL_26 ), [ URL_27 ](https:// URL_27 ), [ URL_21 ]( URL_5 ), [ URL_25 ]( URL_11 ), [ URL_4 ](https:// URL_4 ), [ URL_10 ](https:// URL_10 ). And you have to understand that this was the way it was originally planned because we didn't have search engines, so you had no idea what address to type in, so if you wanted the White House, you'd just type [white URL_47 ]( URL_6 ), since that was something that had something to do with the government. Wanted the United States Coast Guard? [ URL_15 ](https:// URL_15 ), since that was part of the military. And you might ask, who decided that this is what we should do? Well a bunch of engineers. The original domains were put forward in [RFC 920]( URL_3 ) back in 1984. RFC just means \"Request For Comment\" in the IETF (Internet Engineering Task Force) which you guessed it, can be found at [ URL_23 ]( URL_17 ). The IETF is just a group that was formed to create what they felt were the best ways to create a global network since nobody had done that before. RFCs are just guidelines that the IETF puts out that network operators **ought to** follow, but are under no obligation to follow. Following the RFCs is much like playing a board game. If everyone follows the same set of rules, you'll have a fun game. However, if Dave goes off and starts stacking game pieces, it makes the game less enjoyable for everyone. At any rate, in 1988 the United Nations asked the IETF to introduce a new one called: * int for international Because, since the Internet was mostly coming from DARPANet (Internet's father, but I won't go into that) and DARPANet was very \"American\". The com, gov, net, etc... mostly only applied to US commercial, government, networks, etc... You can still find [ URL_52 ]( URL_2 ), [ URL_38 ]( URL_28 ), [ URL_16 ](https:// URL_16 ) and so on, but mostly the int domain has gotten really quiet because... The int domain was a really bad way of solving the issue. No one said the IETF's calls were always 100% right first try. So instead the plan became to give each country code a domain and that's where we get (just a few examples): * tv for Tuvalu * ly for Libya * it for Italy and so on... And it was up to each country to determine if they wanted to subdivide those, which the US is a good example of, because the US decided to give each state their postal code underneath the country code. So you can still find state government websites by just typing in state.(postal code).us. [ URL_56 ]( URL_32 ), [ URL_42 ](https:// URL_42 ), [ URL_50 ](https:// URL_50 ), and so on. However, many states have taken their state server offline and moved it elsewhere, like California used to be at [ URL_9 ](https:// URL_9 ) but has since moved to [ URL_45 ]( URL_40 ). Each state could then further divide that, but all of that has since been discontinued. Only down to the state level in the US remains, for the most part. There's also a few special ones within US, like . URL_48 [ URL_33 ](https:// URL_33 ) is the Forestry Service website. Additionally, all kinds of neat-o things like city.(city name).(postal code).us where created like [ URL_7 ]( URL_0 ), and so on. Most of these addresses have been retired and moved onto other more familiar names. Additionally, each country got a default com, net, edu, etc from the original standard underneath their country. They were allowed to modify the name to better match their country. Which is why we have . URL_46 as opposed to . URL_12 . So if you go to [ URL_34 ](https:// URL_34 ). You'll find the UK version of that company. Instead of . URL_13 , they went with academic or . URL_51 , which you can find [ URL_8 ](https:// URL_8 ), but that now redirects to their shorter domain of [ URL_14 ](https:// URL_14 ). As you can guess, this went incredibly well. (narrator: it did not go well...) Eventually humans stopped care about all of this nonsense because search engines came in and the need to remember city.(city name).(state code).us or twp.(township name).(state code).us or (university name). URL_51 and so on was basically tossed out the window. However, domains were getting filled up. And so, domains like coop, info, name, biz, aero, and even xxx were purposed to sort of try to fit into the original intent (as in porn sites could get their sites at .xxx and then you could just block .xxx if you didn't want to see porn) but by the time they hit the market, search engines had rendered the original meanings useless, and the people controlling .xxx, .uk, .ly, .aero, and so on, just stopped caring about the RFC/\"recommendations\" for what these domains were supposed to be used for and allowed anyone with enough money to buy a domain. However, that didn't stop folks around the world from complaining that every URL was in English letters! And that's where we get IDN (Internationalized Domain Names) so you have China's .中国 and India's .भारतम्. And then of course, people complained about lack of Emojis in URLs. Now we haven't had any top level domains with Emojis but the framework is there and [♨️.com]( URL_29 ) is a valid location, even though it's just a squat site at the moment. And there's [☮️.com]( URL_44 ) that redirects to some site about Sun Tzu's The Art of War. And of course [❤️🍺.ws]( URL_1 ) takes you to Budwiser's website (which by the way WS is the country code for Samoa, but they've been selling domains using their code as an abbreviation for \"website\" since, \"Why stick to the original recommendation to only sell to people actually in Samoa?\"). At any rate, Emoji top level domains are just around the corner. Which if you want to start your own top level domain, you totally can for the low, low price of $185,000 up front, $25,000/yr, a nightmarishly long approval process with a surprising amount of paperwork for being something that deals with something online, you having to buy a ton of equipment to support your new top level, and a four year (at best) review before you actually go public. & #x200B; So long story short, it used to be that we wanted to \"organize\" the Internet by using domains so that people could quickly find things. Turned out, search engines basically obsoleted the need for that \"organization\". So now, it doesn't matter. Hope you enjoyed this very brief stroll down memory lane with me.",
"They’re known as Top Level Domains, and they’ve largely lost their meaning. .com used to mean “for commercial use”, .gov was governmental, .net was network related, .org was for non-profits, and .edu was education. There’s no longer any distinction officially, anyone can use any suffix. Recently they’ve opened up more suffixes as well, almost anything you can imagine, like .cake or .pizza.",
"Answer: Aside from .gov and .edu, they are essentially meaningless now. There is very little regulation on the other top-level domains. & #x200B; When created, the top level domains had actual functions: .com was for commercial websites, .net(work) was for networking websites(your ISP probably has a .net address), .org was designed for non-profits, .gov was strictly for government websites, and .edu were solely for school websites(the latter two are still enforced). & #x200B; Now, there are tons of top-level domains because people were getting clever with country-code top-level domains from obscure countries to spell their websites, and Verisign(who regulates the registration of top-level domains in the US) created a bunch of new ones to get people to stop doing that and give them money instead.",
"The Internet Corporation for Names and Numbers (ICANN) is the overseeing body of DNS. They are the ones who hold the authority as to what top level domains (TLDs) (ie .com or .org) exist. It originated with the fact that the internet assigns everyone on it a number called an address. This is important because this is how the internet works, you connect to someone else's computer when doing anything on the internet, but you need to have a way of identifying each computer, similarly to how each house is identified by a house address. Since computers use numbers, addresses are also numbers. Problem is that remembering numbers for each website is ass to use. So we came up with a method of remembering names instead called the domain name system (DNS). We tie a name to an address, then instead of using addresses, we use domain names (such as URL_0 ). Our computers look up the address for that domain and connect to that address. The thing is that we need a place to start. DNS was designed to be very modular and split up so that one thing going down does not cause everything else to fail. So they split up names into Top Level Domains. Generally speaking, ICANN holds a more hands off approach. ICANN itself does not like messing around with DNS all that much, they are the authority for many other things on the internet and would rather use their resources to do that. So each TLD is given to an administrator, a someone who oversees the usage of that TLD, assigns most of the rules (ICANN has a few specific rules that all TLD administrators must oversee, for example 18 cents per domain registered must go to ICANN, domains registered are registered for a year at a time, ect). These administrators can be corporations, such as Verisign, who administrate .com and a few other common names, governments (ICANN gave each government a TLD to do as they please with, the US is notable for its government having a few TLDs under its belt such as .gov, .mil, and .us, the last of which they didn't need so they gave away for public use), and other organizations. The administrator sets the rules as to who can own a domain. Many domain names are public, administrators negotiate with companies called registrars (such as GoDaddy or Namecheap) for the right to sell these domain names to the public. Governments decide on their own rules for domain use, for example .gov is a domain used only by US government organizations, but britian decided that anyone can use .uk, so long as they add the second level domain .co, so anyone can register . URL_1 . .edu is a special case, IIRC the US Department of Commerce technically administrates it but it gave a contract to Verisign to administrate it since they don't want to mess with it. The rules have changed several times for registering .edu domains (resulting in some not following the current rules because they were grandfathered into the domain) but it is mainly restricted to US post-secondary 4 year colleges and universities. These days, ICANN allows for the creation of new TLDs fairly easily, if you have the money that is. It costs a good amount but ICANN mainly has these requirements to make sure that an administrator does not create a TLD without the means to administrate it.",
"A browser extension is a small piece of software that adds functionality to your browser. What you are talking about is a Top Level Domain. Google can help answer some of the particulars, now that you know the more accurate name, but the TL;DR is that they are really nothing more than categories. In the early days of the internet there were only a few and they were fairly rigid categories. Nowadays we have a lot more because, well, mostly because the companies that manage domain registrations want to sell more, and every new TLD gives people a new chance to have a short and common word for their domain so they sell well."
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a8id1r | Do movies with more special effects take up more space than a movie of equal resultion but no special effects | Could the colour make the file size larger? How how dis work | Technology | explainlikeimfive | {
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"If you're talking about video compression, typically it compares differences between each frame and only includes the parts that have changed. In a movie scene with two people talking, most of the background won't change. That means the compression can be higher. Most CGI movies are heavily motion based with stuff going on all over the screen, so aren't able to be compressed quite so well."
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a8jeeq | How did they hide the camera in this shoot? | @01:52 URL_0 | Technology | explainlikeimfive | {
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"I may be able to give some insight as I've been doing freelance VFX for several years. The film \"Birdman\" had a similar effect in the make-up room, which had lots of mirrors. What they had to do was create a digital version of the room and use 3d matchmoving to perfectly match the movement of the camera within the 3d space. Then they rendered a pass with just the mirrors (reflecting an empty cgi room) and had to rotoscope (precisely cut-out) around anything that passed between the real camera and the real mirror, as well as the reflection of the character in the mirror. I can't speak to this particular shoot, but I would guess they did something similar for the areas that needed fixing. It's definitely a lot of frame by frame work, and the moving camera adds another level of difficulty.",
"Might have covered the rig with a green cover except for the lens, which was then edited out by hand.",
"URL_0 tl;dr: they used multiple takes, motion tracking, and computers to build a virtual version of the scene, then combined computer generated footage of the camera movement through the scene with the live action footage in a way that makes it seem like there is no camera. Even with all that they still had to have people manually touch up errors and artifacts generated through the process.",
"Aside - anyone else reminded of Weapon of Choice?",
"1) WTF did i just watch & #x200B; 2) They more then likely used ChromaKey replacement to just digitally remove the camera. Camera and cameraman more then likely under a blue (or green) cover. May have even used a shoot through fabric to cover the lens... & #x200B; or the mirrors arent real and everything in the mirrors is CG & #x200B; or maybe the WHOLE THING is CG & #x200B; Maybe we are just living in a holographic projection & #x200B; or maybe we are living in a computer simulation & #x200B; ah! sorry... brain went off on a tangent",
"Demonic possession, the all seeing eye. I liked it when they used to be subtle and you had to find it.",
"This can be done fairly easily using the Remove module in Mocha Pro: [ URL_0 ]( URL_0 )",
"My guess is gonna be they edited it out somehow. I know it's common practice in movies to edit out some part of a crew member in a mirror when you're for example filming a scene in a bathroom but this here is kind of a big part of the frame. I don't know, would have probably been a lot of work, going frame by frame.",
"FYI you can embed a time in a YouTube video by adding & t= at the end, eg: URL_0 But good job getting everyone to watch the ad, KENZO viral marketer..."
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