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9wacvr | Why, in this technologically advanced age, is there still such a long pause before "on scene" reporters/guests hear audio from the network studio? | Technology | explainlikeimfive | {
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"Its actually an intentional delay. Its so they can quickly cut from that persons camera before something that they dont want to air on TV happens. On Scene reporters can often find themselves in dangerous situations and you dont want to air an war correspondent getting shot or someone reporting in a hurricane getting taken out by a piece of lumber.",
"Try as we might, physics still limits how fast we can transfer information. For an on-scene reporter, they typically have a TV van with a large dish that transmits data back to the station via satellite. This is because video requires a lot of data and on-site, there may not be WIFI and cellular data is too slow. The sequence of data is as follows: The anchor asks the reporter what is happening The sound/video information from the studio transmits to a dish The dish transmits the info all the way into space onto a satellite The satellite transfers the data to the news van The news van passes the data to a feed for the reporter The reporter responds The video data goes to the news van The news van sends it to the satellite The satellite sends it to the dish near the studio The dish transmits to the anchor and the live newscast This delay for all the information to bounce back and forth can take some seconds of time simply because of all the distance these signals need to take. This is a physical limit that cannot be reduced unless there are ways to provide a more direct route for information to travel."
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9was03 | Building a PC | Technology | explainlikeimfive | {
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"What he said^^ try and get a solid state drive if you can. They are more expensive, but that and a Graphics card for gaming and CAD are the most important things. Try for at least an Intel i5 processor. Minimum 8GB of RAM. The rest isn’t that important. [this site ]( URL_0 ) might help.",
"Look up \"Logical Increments PC Guide\" for a decent layout and some recommendations for each price bracket. I believe they also describe each part of the system but I'll try to cover the basics here: The motherboard allows all the other pieces to talk to each other. CPU is the main brain, this is where the math takes place. The RAM is like your short term memory, 6-8 GB should be fine. It's not permanent but the computer can recall it quickly. Your hard drive is long term memory, you'll likely want 1TB if you're making art and saving games. Solid State drives load quicker than traditional hard drives but are more expensive. GPUs are like CPUs but designed specifically for graphics rendering."
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9wf8e0 | How does Captcha security verification work. Why does it sometimes ask to click on images but other times directly goes through without any tests ? | Technology | explainlikeimfive | {
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"There is no single Captcha system. Basically any system designed to tell humans and machines apart automatically is a Captcha. Some are only designed to tell humans from machines. Others have a secondary function of also *teaching* machines. For example, when you're clicking those pictures, you might be confirming that you're a human, but you might also be helping to teach AI how to tell those pictures apart."
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9wg0lc | Why are server CPUs not that good at playing games? | I know it is something about the number of instructions executed per second, which is slower. But most games utilize all the cores I have in my current CPU. So wouldn't having more cores be beneficial? | Technology | explainlikeimfive | {
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"Server cpus are a fleet of minivans, where as computer cpus are like 4 tuned racecars. If you want to deliver a lot of groceries in normal city driving, the fleet of Minivans will do it better. The 4 tuned racecars will eat up way more fuel, run hotter, and have to take more trips than the fleet, ultimately ending up slower. But the fleet simply can't go as fast, no matter how many vans you send at once, if you try to send both on a racecourse.",
"More speed requires more power, which creates more heat and instability. Most \"server\" apps are relatively take in terms of processing requirements. As such, server CPUs are built to run a lot of processes at oncw, but do so at relatively tame speeds. Consumer/\"gaming\" CPUs on the other hand typically have fewer cores running at higher speeds. This makes them good at running a couple of demanding processes (like a game), but they'll lag behind if you try to install a baremetal supervisor on them and spin up a dozen VMs."
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9wh4ft | How do lightning tracker websites work? | Sitting on the toilet just now during a thunderstorm and a huge bolt of lightning flashed outside that must have been 2-3 miles away. I was watching the live lightning map on [ URL_1 ]( URL_0 ) and the flash that just saw was on my live map within 10 seconds! How is it possible to track the sky on a global scale like that? | Technology | explainlikeimfive | {
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"/u/krystar78 describes the community data sharing, but as for the science: they use radio waves. The stations detect the VLF (very low frequency) radio signals emitted by lightning flashes, precisely measure the time the signal arrives, and use the speed of light to calculate a distance. By measuring the distance from several different observing stations, they can triangulate the lightning's position. You can watch the URL_2 system doing this in real-time here. Sometimes stations on the opposite side of the planet from the lightning strike will \"hear\" its radio pulse, just milliseconds later! URL_1 Info on the network: URL_0",
"There are lots of community and privately owned weather stations that report into the system. You can see alot of these if you go to URL_0 and go into detailed station listings. It wouldn't be surprising to see at least 10 in your local area."
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9wjori | How is DRM such as but not limited to Denuvo cracked? | Technology | explainlikeimfive | {
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"The simplest explanation from a man who knows very little about the subject Lines of code are used to trick and ignore the various if/then statements you have to pass in order to launch the game, some if/then statements are more complex then others.",
"At it's simplest level, they replace the line of code that says 'run drm module' with a line that says 'do nothing'. It's much more complex and tricky in reality since drm is in a constant race against software hackers to make a system unhackable for as long as possible (in the past several years, the most successful systems lasted less than a year, usually just a few months). At a more abstract level, what makes cracking drm possible is the fact that software is merely a list of instructions (and artistic assets) performed by a machine owned and controlled by the user/hacker."
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9wlgve | What is the difference between Cloud Computing and Web Hosting? | Fifteen years ago people who own dedicated servers or colocate their own servers for hosting websites. But nowadays more people are using Cloud for that. What is the difference? I notice web hosting charges a flat monthly fee but cloud charges differently. If I had a website is it better to use cloud or regular hosting? | Technology | explainlikeimfive | {
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"Imagine you live in an apartment. You might not always be using it, but it's still yours. Whenever you want to use it, you go to the same building, and open the same door, and you're back home. If you need to go across town, you drive a bit further. If you intend to have guests over, you have the set amount of bedrooms. That's web hosting. Your site is installed on a directory on a hard drive on a computer somewhere. There will be a bunch of other sites on that same server, but you're all neighbors, that's your place. Now imagine a global hotel chain. You don't own any of the rooms. In fact, you have no idea who is going to be in what room on any given day, or even any given hour. But, when you need a room, you can make a reservation. The hotel staff pulls up your information and preps and sets up a room for you to use. You don't own it, you don't know what room until you get there, and you kind of don't care. It does what you need, be a dwelling. You never have to drive very far to get to where you want to go, because you can simply get a room in a hotel in whatever area you need to work in. If you suddenly have a ton of guests, you can simply ask the front desk to get you a dozen more identical hotel rooms to accommodate your new needs. This is cloud hosting. Your code doesn't reside anywhere permanently. Likewise, the \"rooms\" or servers that host code change constantly on what is on them. Wherever you want, and as much as you need, your code is then loaded temporarily into one of these rooms. Alternatively, when your code isn't in use, it's not loaded anywhere. In the vast amount of personal web page situations, a simple cheap web host is fine and much easier to deal with."
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9wljuk | Going from 720p to 1080p is quiet a drastic improvement, while the difference between 4k and 1080p is minor; Why? | I was curious as my new 55'' Samsung 4k TV is not much different in quality than my old LG 50'' 1080p TV. | Technology | explainlikeimfive | {
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"Imagine you have an infinite number of square cardboard boxes (pixels) to make a wall (your TV) Every box you stack is going to make a massive improvement in the visual size of your wall up until you start getting into the hundreds, now every box you add is going to seem like less and less of an improvement. Why? Because the human eye isn't microscopic and is only going to register so much detail before it doesn't matter. Source: I've been talking out of my ass on Reddit since back when it was called MySpace.",
"You're probably haven't calibrated your monitor properly. Also, folks are getting confused between *viewing resolutions* and *source resolutions*. The reason why you may not be seeing 4k properly can be due to a number of factors ranging from the source video signal to the cables used to connect your TV to the cable box. First a little background. If a filmmaker shoots video in 720p the source video can only ever be 720p. However, you can view 720p video on your 4k TV because it can upscale the image, or rather 'fill in' the screen with the picture. But the video will look blurry or not right because the video source and your TV don't match. If a filmmaker decides to shoot in 4k, but creates the final edit of his movie in 1080p. Even if your TV is 4k, it will only be able to display the movie in 1080p because the source video is only 1080p. The filmmaker has down scaled his nice 4k video to 1080p. Now if a filmmaker shoots in 4k and creates the final edit of his movie in 4k. Your TV will display the movie correctly in 4k. eli9 Going from 720p to 1080p didn't need any new hardware to get a better quality image. You probably just plugged in the same cable and saw a better image moving from 720p to 1080p. That's because the technology built to view 720p could also handled the increase bandwidth of 1080p. However, 4k is a different beast all together. There needed to be a whole new set of technology created so you can watch 4k properly. Start with your source video. Is that video 4k? A blu-ray disc is not 4k, it's max is 1080p. So if you're watching some old blu rays trying to tell the difference on your 4k TV, you won't notice a difference. However, if you buy one of the UHD disks or have a Ultra HD netflix account, your TV can display a video where it's source is 4k. However, there's also the cables that you use to hook up your TV. Remember they needed to invent a whole new set of technologies for 4k? Same with the cables as well. Display Port and HDMI 2.0 are the two most common connections for UHD. If you're connecting via any other way you may not be seeing your 4k picture correctly. 4k is way superior to 1080p. Most people don't have their TVs set up properly to view 4k tho. But what you can do is check the source is a 4k, your cables can handle 4k signal, and your TV is setup to display 4k images and you'll be really impressed with what 4k can do.",
"I believe it’s because at more than some distance away your eye can’t tell the difference. If you sit close to a 4K (within 6’ depending on the size) it will be better.",
"very ELI5 answer: it’s easier to discern changes in quality at a smaller scale than at a larger scale. a candle lit in a dark room is immediately noticeable, but not at all in daylight.",
"Pixel density, pixel count relative to screen size. The difference between a 4k 55in and a hypothetical 50k 55in isn't going to be super huge as you're sitting 12ft from it. But if the screen were 100in, the difference would be more noticeable."
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9wln18 | Why is a movie file size smaller than what each frame would be if it was an image? | I know the question isn't worded very well, but I don't know how to word it better. I've heard an average 4K movie is around 40GB. An image with the average 4K resolution of 3840x2160 is around 23.7MB. If an average 24FPS movie was being played back with each 23.7-megabyte image, 40GB would be taken up in 72 seconds. How is a two-hour movie compressed to that size that otherwise would be just over a minute? | Technology | explainlikeimfive | {
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"Compression works by basically reusing pixels from the previous image that haven't changed instead of loading a fresh pixel for every frame. For example, if a scene includes a shot of a blue sky, most of those pixels won't change between frames, they'll stay blue. Therefore those blue pixels don't need to be updated, only the part of the image that changes needs to be loaded.",
"Video compression. You can store video in a smaller space if instead of describing each pixel in each frame you only describe the pixels that change between frames and tell the video player to just keep the rest the same. This is how we are able to stream HD video without having ridiculous bandwidth. & #x200B; Here is a video: [ URL_0 ]( URL_0 )",
"If you think about it, two back-to-back frames from a movie will usually be very similar pictures, since they're just separated in time by 1/30th of a second (assuming 30 frames per second). Rather than save both frames as separate pictures, movie file formats can essentially save the first picture, then just save the difference between the two. Since there aren't many changes between the two pictures (frames), saving the second one takes a lot less storage space. Likewise, just save the changes between the 2nd and 3rd frames, etc. Might not be completely accurate with regards to modern movie compression algorithms, but I think the concept is illustrated for an ELI5."
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9wnark | is the speedometer on waze to be trusted? | When I align the speedometer on my car exactly at 120 km/h, waze says I drive 115 km/h? There always seems to be a difference of about 5 km/h. This makes me think I can't trust either my car's or Waze's speedometer. Also, how fast am I actually going? Which one is more correct? | Technology | explainlikeimfive | {
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"Generally GPS based speedometers are considered to be more accurate. A number of factors can be at play with the physical speedometer in your car including gear ratios and tyre rolling circumference. Any variations especially in your tyres can cause the speedo to read faster or slower so car manufacturers tend to build in a tolerance in your favour to protect you from getting speed tickets etc.",
"Car manufacturers usually add a little safety margin on analog speedometres to allow for larger size tires to be fitted. As the size of the tire increases it has a side effect of increasing your overall speed. A good calculator for this is [TyreSizeCalculator]( URL_0 )",
"The GPS speedometer is more accurate. Car speedometers are based on how many revolutions your tires make, but as tires wear, their circumference becomes smaller. Plus by law (at least here) the car speedometer can be incorrect, but can never show a lower speed than what you are actually driving. So they are typically a bit off overestimating your speed. 120 on the car speedo really being 115 is just about typical. Oh and how correct GPS speedo can be? I do TSD racing. End September we had a 54.7 km stretch where we didn't make any mistakes, drove the correct route. The distance driven shown by the GPS was 150m off. That's as close as you'll get even with a proper real tripmaster.",
"UK/EU experience here, your mileage may vary: Car speedometers BY LAW \"may\" read faster than you are really going but MUST NOT read slower, if you think about it this makes sense for road safety & legal implications if you get pulled over for speeding. Most cars therefore read 5-10% \"faster\" than you're really going by design. This also gives margin for slight differences in tyres etc. GPS in theory should be much more accurate but it depends on the quality of the fix / signal and the software in the GPS, hence GPS speedos are not road-legal as, without a good fix, you can't be sure it will even know you're moving. In cities, GPS coverage suffers badly (google \"urban canyoning\") making it a bad idea."
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9wnhbt | are external hardrives essentially bigger USB drives, or is there something that differentiates them | Technology | explainlikeimfive | {
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"From a user standpoint they operate the exact same. From a technical standpoint if the external drive is a solid state drive (no moving parts) it is effectively the exact same as a flash drive. If it's not a solid state then it reads and writes using a spinning disc.",
"They're the same as the internal ones, the only difference is they come in a box that protects them and transforms the external interface to the native interface (usually USB to Sata). So the answer to your question is no, a hard drive is based on a different technology than an USB flash drive, regardless of it being external. Now there are also the SSD drives which are essentially bigger and better made USB memories, but again that has nothing to do with whether they're external or not."
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9wo4xr | Back in the day, US television used to look awful in the UK due to PAL/NTSC conversion. It doesn't any more. What's changed? Is the conversion obsolete for digital formats? | Technology | explainlikeimfive | {
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"In nearly all cases nowadays the video will be produced in a format much superior to PAL or NTSC and only converted to the target format for broadcast. With older video that was originally stored in NTSC, you can now do fancy digital processing that gives a much better result than the older conversion methods."
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9wq5ky | How come we can't just filter out the salt and stuff from the ocean and have huge sources of fresh water? | Technology | explainlikeimfive | {
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"We can. It's a process called [Desalination]( URL_0 ). The problem is that it is laborious, expensive, and/or time consuming to do.",
"We can, it's called reverse osmosis. The problem is that it's very expensive to do that compared to how we get fresh water right now, so economically, it's not a viable option (for some countries it is though).",
"But we actually do, for example in Malta all the water is purified with reverse osmosis from the sea, but it’s definitely not the best method: it takes an immense amount of power and the water needs further treatment, and needs added minerals and salats, and it may not even come out drinkable",
"Israel now gets 55 percent (or more) of its domestic water from desalination. URL_0",
"We can, but it tends to be time-consuming and the upkeep of the machines involved is expensive and to many, not worth it."
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9wr413 | How does a smart phone responds to a touch? | Technology | explainlikeimfive | {
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"The inside of the screen carries a small charge. Placing an object, like a finger, on the outside that can act as the second half of a capacitor and distorts the charge pattern. The position of the distortion can be traced by the circuitry to know what action to hairdressing on its location Think about those toys with the plasma inside where the arc follows your finger as you move it on the outside of the glass globe. EDIT - Damn you autocorrect and touchscreen tablet! I'll leave it there for the giggles. Should have been \" action to take depending on its location\" or something like that."
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9wrwai | What is RCS messaging? | I have a pixel 3 and rumors are flying around that Verizon is going to support it here soon, what exactly is RCS? | Technology | explainlikeimfive | {
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"Imagine chats like iMessage, WhatsApp, and such. The features found in those is pretty similar to RCS's feature set . Unlike SMS, which is the default messaging service currently, RCS lets you send audio, real-time video chats, more than 160 characters, create group chats, and display data such as \"message read\" or \"typing...\" in real time."
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9ws4wh | why image files vary in size even when the picture resolution is the same | Technology | explainlikeimfive | {
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"Images are built out of pixels, think of them as little building blocks that have a single colour. Resolution merely defines the height and width of the field that is filled with those little blocks. For example 10 blocks by 10 blocks. Imagine if every pixel on the field is green. That's pretty easy to remember. Even if you have an enormous resolution with many pixels, all you have to remember is \"The field is a million by a million pixels and they're all green!\". Easy peasy, you don't need much memory for that, you could write it down on a post-it. Now imagine if you have a huge field and every single pixel is a different colour. That's practically impossible to remember. You'd have to write down the colour of every single pixel on the field and its location. You could fill a book. That's why image file formats use compression algorithms to make it easier to remember where all those coloured pixels are. For instance, if we have a chess board, you could say A1 is black, A2 is white, A3 is black and so on until you wrote down all the colours on the board. Still takes quite a lot of memory. One simple trick you could use is lumping all the similar colours together. For instance say in the columns A, C, E, G all the uneven numbers are black on the chessboard. In B, D, F, H all the even numbers are black. The rest is white. Digital images use compression algorithms that do kind of the same. They use memorisation tricks to avoid having to remember every single pixel's colour value. The fewer color variations there are in a picture, the less memorisation work there is to be done and the smaller the file size can be. That's why a picture of a rainbow can have the same resolution (total number of pixels) as a picture of a chessboard, but the chessboard image will likely need less space to remember all the colours that appear in the picture.",
"Lots of image formats use compression which means that the amount of data required to store an image depends on the the content of the image. Some image content is easier to compress than others.",
"Pictures don’t typically store each individual pixel. The image is compressed so that each pixel can be drawn, with varying accuracy, with less information. Depending on how compressed the image is, the file might be larger or smaller, even if the resolution is the same. Take Netflix video and Blu-ray video. They are both producing a 1080p image, but Netflix is using less information to create that image. If you’re really sharp-eyes, you might notice some issues in the backgrounds of shots in a Netflix show. That’s because Netflix video is more compressed.",
"Almost all images in use today is compressed. The compression algorithms used will identify patterns in the images and by using these patterns they reduce the information required to reproduce the image. So different images might be easier or harder to compress then others as they have different patterns. There is also differences in the compression algorithms. So an image which compresses well with one algorithm might not compress as well with another one, even though the second might be better on average. This is why you for example see png and jpeg being used on different types of images. In addition some algorithms are actually not able to fully reproduce the original image but will ignore small details that is hard to spot. However you can tune this feature so that you get visible image artifacts but a smaller image."
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9wurie | A couple hosting Nintendo ROMs was just sued by Nintendo. How does google avoid lawsuits for the same content being uploaded to Google Drive? | Technology | explainlikeimfive | {
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"Liability for hosting copyrighted items is covered by the Digital Millennium Copyright Act. This act makes internet hosting providers immune to liability for hosting copyrighted content so long as they don't know that the content is infringing and follow the provisions of the DMCA when notified of infringing content. Google doesn't have actual knowledge of the content of what is hosted on google drive. Even if they are parsing it for advertising or antivirus purposes, that parse isn't good enough for them to have knowledge of the contents of the files. Google also follows the provisions of the DMCA when notified of infringing content. In the Nintendo case - the owners of the website were either uploading the ROMs themselves, or had actual knowledge of what the ROMs were as well as their infringing nature. Because of that, they were not protected as a hosting provider under the DMCA.",
"Google doesn't own anything hosted on the drives. In most case they aren't aware of what even on them. All Google really needs to do is claim user privacy \"we don't go through their drives\" The people being sued knowingly uploaded and hosted the stuff they couldn't claim they didn't know what it was"
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9wvt0x | How do finger print readers work on your phone? | Was just looking at back of phone trying to think how do finger print readers work. Usually the animation shows a picture of your finger print, but obviously your phone is not taking a picture... or is it? | Technology | explainlikeimfive | {
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"It's not a picture, not exactly. Most fingerprint readers nowadays are capacitive readers, kind of like the mechanism that drives touchscreens. But instead of merely detecting that the screen was pressed, there's an array of hundreds or thousands of capacitors which create a unique \"map\" of your fingerprint -- or more accurately, the changes in electrical capacitance caused by your fingerprint's ridges touching the scanner plate -- and the gaps between them *not* touching it. Once your phone stitches the maps of several samples together, it has something to compare against, and if the finger you touch to the scanner matches to a high enough degree of confidence, the phone figures it's your finger, and unlocks."
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9ww36o | Why does slow motion video always look very dark? | Technology | explainlikeimfive | {
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"To make slow motion, the camera has to take more pictures in the same amount of time. This means the shutter has to open and closer faster, and it's open for a shorter amount of time. This means that less light gets in for each picture.",
"Cameras work by gathering light. Very few light and the pic will be dark, too much light and it will be very bright. To gather the light we have 3 settings: Aperture: How big is the hole from where the light enters the camera. The bigger the hole the more light enters in the same amount of time. ISO: The sensitivity of the camera sensor. More sensitivity more light. Shutter speed: the time it takes to take the picture. More time taking the picture equals a brighter picture. When filming slow mo you have a very fast shutter speed so you need to gather the light from the other 2 settings. The problem is that aperture can only do so much by itself because there is a limint on how big the hole is, and when you bump up the iso you tend to lose quality. So basically we compromise on getting a slightly darker image with a decent quantity rather than a perfectly brigth pic with poor quality."
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9x0155 | why can computer games run at 60+ fps (even in vr) with this IMMENSE amount of textures, polygons, physics and lighting, while rendering a single comparable frame in a 3d program takes many minutes (at best)? | Technology | explainlikeimfive | {
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"They can't. They bake their models to remove as many polygons as possible without making a visible difference, downscale the textures whenever possible, completely ignore the laws of physics in favour of a greatly simplified system, and use one (or more) of a hundred different tricks to speed up the lighting (including making shadows a static part of textures *by default*). The 3D program assumes you'd like to get that last 1% quality no matter how much it hurts performance, and so doesn't apply any of these tricks unless you specifically ask it to. The good ones also do things like subsurface scattering of light by default. Note: depending on your computer, doing all this can take *hours* for a simple water scene in Unreal Engine if you want it to have waves. We're talking 2 polys and a bunch of mathematics, here.",
"The Difference is in the quality. A Rendering program will attempt to stimulate light (including reflections) to get it as realistic as possible. A game does enough to make it look passable. & #x200B; Rendering wise games take the 80/20 rule and run with it getting 80% of the quality with far less resource",
"They cheat. The frame *looks* comparable, but isn't. Game level designers carefully design stuff so that it fits the performance limitations - so that the things that are difficult and time-consuming to render either can't happen (i.e. if your renderer looks ugly in object interaction X because of performance sacrifices, you move things around so that X doesn't happen in your game), or are pre-baked (e.g. the light is always at the predesigned angle, so they can pre-calculate things before shipping the game to you), or are carefully simplified (instead of rendering the shape/texture \"as intended\", which you'd do in a 3d program, the engine replaces it with a simpler version if it won't make much of a difference), etc, etc.",
"The easy answer since I’m at work is that the math has already been done when you’re playing a game. The system just has to read and recreate, but when you’re rendering the scenes for the final time it has to add and create all the math and numbers for the graphics.",
"There are basically two reasons: - (a) Computer games are universally programmed to take full advantage of hardware acceleration. - (b) Computer games use a more efficient process Item (a) is pretty straightforward. Games use hardware acceleration because every modern PC and console has some kind of GPU (graphics processing unit), and it lets you improve the graphics a lot -- resolution, polygon count, everything. You might be surprised to learn that the render option of 3D modeling programs doesn't necessarily use the GPU. It uses a technique called *ray tracing*. It produces great looking results, but it involves doing calculations per screen pixel, not per polygon. Which means it takes longer than scan conversion for typical scenes on typical hardware. GPU's are built to do a different process called *scan conversion*. Ray tracing on a GPU is possible these days, but it's a real pain involving lots of custom GPU programming. Ray tracing has a few other upsides compared to scan conversion, namely that it much more easily allows shadows, reflections, and curved surfaces. Now let's talk about (b). One frame of a 3D game is made by drawing a bunch of triangles. You know where the triangle's corners (vertices) are in 3D space, where the player's viewpoint is, and which way the player's facing. You (or more specifically, the GPU) can do math to convert the triangles' vertices from the 3D points in the scene to 2D points on the screen. Then draw them as 2D triangles. To determine the point's color, texture / lighting is applied. This whole process is called *scan conversion*. Today's GPU's support running small custom programs which can implement a wide range of effects in the hands of a skilled programmer-artist (called *shaders* because they were originally mainly used for texture / lighting effects, but they're now used throughout rendering).",
"Games use tricks to do things that are far harder to do properly. For instance, typical game trick to draw reflections: take your model, draw it upside down and maybe blend the color a bit. This works but in a limited set of cases. Games rely on these sorts of tricks and it works because they know a situation in which it doesn't is never going to happen. A 3D design program though can't count on that kind of thing happening and has to do all the hard work of calculating it precisely."
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9x2j2s | Why can't two phones just automatically connect when they're calling each other at the same time? | Technology | explainlikeimfive | {
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"The short ELI5 answer is because that's not how they work. When calling it looks to ring and can't be rung. If they're both calling they're both looking to ring, and can't be rung, so it doesn't work. The system *could be* different, but isn't, and the odds of a major change to the underlying infrastructure like would be necessary are low."
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9x36o6 | why Gameboy/GBC Pokémon game saves rely on a battery when newer ones don’t. | Technology | explainlikeimfive | {
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"Back in the day, data was saved on the cartridge, which used volatile memory. volatile memory requires power in order to hold data (in a normal computer, this is like your RAM), hence the battery. If the battery dies, it won't hold data. Modern day electronics have room for nonvolatile memory, using Flash RAM (like your PC's hard drive, it can hold your data even when it's powered down), which doesn't require constant power. Flash ram got much cheaper than it was when these games originally came out, so much games started switching away from the volatile memory"
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9x3btd | How does GPS jamming work? Like what the Russians did during the recent NATO exercise. | Technology | explainlikeimfive | {
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"The same as normal jamming, they sent out a bunch of signals on the frequency that GPS satellites use to confuse the receivers- like trying to hear a code someone is telling you(The GPS signal) when someone is shouting in your ear(The Russian Jamming.) 01001 01100 01001 01011 00101 10100 10010 00001 01001 01110 10011... #I LIKE TRAINS, VARIABLE-SPEED CORN MUFFINS, HI GUYS WHAT ARE YOU TALKING ABOUT, ARE YOU HAVING A CONVERSATION, AM I INTRUDING?",
"First how GPS works: GPS satellites in orbit are like special radio stations that continuously send a very long pattern of numbers and their positions relative to the Earth. GPS receivers are radio receivers that know the same pattern. The receiver compares its pattern with the transmitted pattern to know how long ago the GPS satellite sent it. This time delay is converted to a distance and the distances from three or four GPS satellites are used to determine the location of the receiver through a calculation called triangulation. Jamming: Unfortunately, civilian GPS is not securely verifiable so a receiver can't tell the difference between a real and fake transmission on the same frequency. Russia probably transmitted either noise or a shifted version of the pattern to confuse receivers , making the receiver believe satellites were closer or farther than they really are. If the Russian transmission was stronger, which is easy to do since the real transmitters are all the way in space, they could cause GPS receivers to report an incorrect location. Edit: Since you were asking about a military drill specifically, it's likely Russia was just transmitting noise to prevent the real signal from being received. Civilian GPS is even more vulnerable in that an attacker can create fake signals to cause a receiver to believe it's in the wrong place, though it would be hard to do for multiple spread out targets simultaneously."
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9x5fir | How do gloves with “touch” fingertips get recognized by touchscreens | Technology | explainlikeimfive | {
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"Screens detect your finger's through an electrical flow. If you hold a metal conductor like a key and tap your screen it will work ( But dont, you might scratch your screen.) Screen touch gloves just have a better conductor at the finger tips.",
"Manufacturers use capacitive thread - thread that has electrical conductive properties. Pro Tip - you can buy just the thread, and stitch a small pattern of your choosing in the fingertips of any gloves you want and it will have the same effect. Just make sure the thread is on the inside and the outside, so your finger can touch it."
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9x6iow | when polishing or sanding why do you start from corse and work down to fine? | I've watched a few videos where people are making something extremely smooth or shinny and notices they always change sandpaper grit and I started to wonder why is this needed. Can't you just use a fine grit for the whole process? | Technology | explainlikeimfive | {
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"Your working out the deepest scratches as quickly as possible. If you start with a grit more fine than the deepest scratch it will take longer to remove the metal down to the depth you need.",
"You could but it would take much longer. The grit roughly equals the amount of the object removed by sanding. Very fine paper polishes the surface but would take much, much longer and more effort to get it into a finished state. Example, rough sandpaper is like, say, cutting six inches off a board at a time. Super fine sand Paper is cutting a tenth of a inch at a time instead. Roughly speaking in this example.",
"Getting eaten by lions is faster than getting eaten by ants. But lions will miss the little bits of meat, which is where the ants come in.",
"Imagine if you had a giant ball of cheese that was super spikey. Like there were points of cheese sticking out in every direction of different sizes. You decide you want to make the cheese ball perfectly round but you can only use your teeth. You’d start by taking huge bites from the biggest pieces sticking out. But as you got closer to the round shape you’d take smaller and smaller bites into at the end you’d just be barely nibbling. Changing sand paper grit to fine is like taking smaller bites. Sand paper leaves scratches just like you would leave bite marks but if you make them small enough no one will be able to see or feel it.",
"You could, it would take you three times as long. Say you've got an untreated section of wood you're trying to smooth out, if you start with a lower grit, you can get most of the \"grunt work\" done, and by that I mean the places that require heavy sanding. After thats done and you've got the general shape or design you were looking for, or prehaps you've removed the more rough areas of the object, you can then start using higher grit. Higher grit allows you to smooth the surface out without removing too much material, and as you move on and use higher and higher grit, your surface will become smoother. Higher grit simply allows you to make the rougher texture you get from lower grit more fine, giving you a much nicer finish."
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9x6y6t | Why do come car stereos only have Bluetooth for calls | Technology | explainlikeimfive | {
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"text": [
"In the beginning, bluetooth was for headsets, so people you didn't have to spoil your fashion with dangling wires (and wired headphones are kind of a pain when wearing a suit or even a sport jacket). Later, bluetooth expanded to support near-music-quality audio. This is a separate mode of bluetooth, and isn't supported by older devices."
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9xai2h | Why do computers have a blue screen of death? | Technology | explainlikeimfive | {
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"text": [
"It’s a simplified interface to explain why the computer failed. If it just shut off on you when it died, you might not know and might not ever do anything about it. The BSOD is a result of a quick diagnostic, providing an error code so you can start troubleshooting. I hope this helped!",
"The blue screen of death is simply the Microsoft Windows fatal error screen - it occurs when the operating system encounters an error it absolutely can't recover from. In the olden days of Windows 95, the OS would easily crash over the littlest things, such as taking out a CD from the drive while it was being read. Nowadays the system is much more robust, and will only crash when a truly unrecoverable error happens, such as a hardware error the prevents the OS from accessing the RAM.",
"Your operating system has a core component called \"Kernel\" that interacts with the hardware through drivers and provides basic facities to programs and libraries (such as making network connections, writing to files, drawing on the screen ...). A blue screen of death happens when the Kernel gets confused for some reason. Back in the day, this was mostly due to programming errors in the kernel or the drivers, or the programs that used these basic facilities. Modern kernels are much better at handling these kinds of errors, so most of the time when you see a BSOD is when you have a hardware problem: some piece of your computer failed, and behaved so unexpectedly that your Kernel couldn't handle it. & #x200B; Note that this is not specific to windows. This also happens on Mac and Linux, and it's called a \"kernel panic\" (or \"kernel oops\" on Linux)."
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9xb1wp | Could Space X Patent Reusable Rockets? | So I work in software and there are so many news stories about software patents being used to sue developers for basic things like "using Internet to send mail" level of obviousness. Why couldn't Space X have a patent to demand royalties / licensing fees from other rocket companies for any future attempts to make reusable rockets? Note that I'm asking "could" they, not "should" they... I don't want to see innovation or competition stifled. | Technology | explainlikeimfive | {
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"> Why couldn't Space X have a patent to demand royalties / licensing fees from other rocket companies for any future attempts to make reusable rockets? The basic concept of wanting to reuse parts of a rocket for multiple launches isn't novel enough to be considered patentable. They can patent a specific implementation of a reusable rocket but they cannot patent the goal no matter how it is achieved.",
"Patent trolls target people who don't have the money to fight their bullshit in court, so they end up settling. Jeff Bezos and Richard Branson do not fit that description.",
"I'm not an expert by any means but I do follow what SpaceX does. I believe a reason they dont patent the software and technology behind what they do is because they would to my knowledge have to reveal the details of the software and the hardware they use. Im happy to be corrected by someone with more knowledge."
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9xb9x7 | can someone explains 40-80 rule in charging and how it works , please ? | can someone explain 40-80 rule and how anode & cathode works ? and what happens to lithium ion batteries during charging | Technology | explainlikeimfive | {
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"So the chemicals and components in a battery decay over time, and with extreme charge levels. Discharging more deeply, or charging to a higher level, both induce wear on the battery chemicals and the components, and over time, this will reduce the overall charge the battery can hold. This is the primary reason why a two year old phone won't stay charged as long as a new out of box phone will. The 40-80 rule is a way to maximize the lifespan of your battery by limiting wear; specifically it refers to not discharging below 40% and not above 80%. Charging above 80% becomes increasingly hard(you can notice this by how much slower a phone charges as the charge level gets above this) which wears down the battery. Cathode and anode are the terminals where power flows in and out of the battery to provide the juice to your device, by my understanding. I don't know I can help on 'what exactly happens', unfortunately."
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9xbrk6 | How does the Ext4 Filesystem work? | Technology | explainlikeimfive | {
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"text": [
"Both NTFS and FAT is fixed designs which had all its featured set when they were designed and it is hard to add or remove features or change the behavior. However the EXT family of file systems were designed with extendability in mind. So the mandatory structures offer very little features in itself but most of the features is implemented as extensions. This means that if people want to add, remove or change features they can do this and still be backwards compatible with other systems that do not support the same features. This means that a lot of people have added these optional features to the file system over the years which can make it more complex but much more powerful. It also gives the administrators of the machines more flexibility in how they want the file system to be like. Different applications might require different features or parameters and with EXT this is possible to do."
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9xbtcg | How are there graphic cards for specific purposes (e.g. mining)? What's their difference? | From my basic understanding, the perfomance of a graphic card (gc) is determined by two things: performance (operations per second), and memory (size and speed of access). Now, my understanding is that bigger and faster is always better, how come some gc can de better in games, but others better for mining or finding prime factors? | Technology | explainlikeimfive | {
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"Because they optimize it for different tasks. A gaming graphics card is designed to produce an 'acceptable' result on schedule to push out the next frame. The designers know that the effect will only be on screen for a fraction of a second, and as a result they design the card to go 'good enough' if its falling behind and push out the result, even if it hasn't figured it all out perfectly yet. With an engineering card, you need to figure out the number PRECISELY, as rounding errors in, say, building a bridge could kill people if the bridge collapses. So the card is instead programmed to take as long as it needs to figure out the numbers involved,, but this is suboptimal for gaming as it won't produce speedy results."
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9xccoh | Train windows that turn opaque and clear and then opaque again. What’s it called? And how does it work? | I first saw this in when I was on a train in South Korea and it drove me nuts trying to figure out how it worked. And I didn’t even know what those windows are called. Smart windows? Frosted windows? Opaque windows? If someone can answer this I would be really thankful, cause I’d finally be able to sleep at night. Lol. | Technology | explainlikeimfive | {
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"**Electrochromic glass** (aka \"smart glass\"). It's basically a giant LCD screen. When voltage is applied, the crystals all align in such a way that light can't pass through.",
"[Smart glass]( URL_0 ). This can be used in windows, glasses, greenhouses, welding masks, motorcycle visors, etc. and be controlled either by electric signals, temperature, or just light. That last one is specifically called photochromic glass. As far as how they work, the only one I know how words is liquid crystal electrically controlled glass. This uses two polarization filters offset by 90°, with a layer of liquid crystals sandwiched inbetween that can either be set to 45° to let through some light, 0/90° to block nearly all light, or somewhere inbetween. This is exactly the system used by LCD TVs."
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9xclzw | How do sports announcers pull random factoids during live coverage? | Technology | explainlikeimfive | {
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"There are an orgy of supporting personnel that prepare these factoids for the commentators.",
"They have a team of producers and statisticians that have done their research beforehand. They can relay the message to them through their headset during the game. The announcers also do their own research before the game.. the good ones at least. So basically, a team tells them through their headsets.",
"They have an earpiece with a live feed playing in their ears. They are fed information continuously.",
"Besides stuff prepared by the TV crew (Fox Sports, YES Network, whoever's carrying your game), feeds from Elias Sports, etc, the teams themselves release press packets with lots of stuff in it. Forgive me if you're not a Yankees fan, but you can get theirs online (probably other teams' too if you poke around). Here's a link for the Yankees: URL_0 (change the month pulldown to be in season and you'll see them) If you read it in advance sometimes you can notice the game announcers reading right from it."
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9xcndn | Why do computers become slower over time? | Technology | explainlikeimfive | {
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"Several things. On an installation level, each program you install adds 'weight' to the operating system by giving it more tasks. These aren't always removed cleanly when you uninstall, which makes it important to reimage your computer about every year. Additionally, if you use a standard hard disk drive, the drive fills up and files are 'fragmented' in pieces across the drive, requiring extra time to access. More generally, technology is always advancing, so the target of what is a powerful computer is moving. What was \"Good\" or \"Great\" last year is merely \"average\" this year, and might be \"Mediocre\" next year. Developers write software in mind with a general idea of what hardware is on the market and how fast the slowest computers are, and so as time goes on, the programs become more complicated with more features, aimed at newer computers than yours, and while the weight of the program is increasing, your computer's processing capacity is static without upgrades.",
"As computer programs become more and more advanced, they require more and more RAM and processing power. Your computer stays the same age and becomes out of date due to the hardware not being updated, and the programs being constantly updated."
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9xdbkc | getchar() and putchar() in C | I swear my head hurts. I'm trying to understand this since like an hour. & #x200B; I understand that getchar() takes input a character at a time, and that putchar() displays one character. I went to [this]( URL_0 ) website because people on stackoverflow keep shitting on me for asking stupid questions. Dont hate me reddit please im desperate. & #x200B; I dont get the `while ((ch = getchar()) != EOF & & n < 1000) { str[n] = ch; ++n; }` part in particular. what is the condition doing? why is ch an integer? why does it look like it's accepting the input in the while loop condition? is that what it's doing? Please dumb this down for me. Jesus Christ I'm about to burst a nerve in my head. I get it. it's not supposed to be complicated. help me though. Also please advice on not raging when i hit a roadblock. thanks. | Technology | explainlikeimfive | {
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"So, basically this is saying take up to n characters from the file. If the file doesn't have that many, stop at the end. If it has more, still stop at 1000 because that is (presumably) the size of the statically allocated string. I'm not sure what you mean by ch being an integer type.",
"In C, a **char** is 1 byte of data. It is often used to store a printable ASCII character, but it can also be used to store a number. They are treated the same by the code. char ch = 'a'; char ch = 97; These lines are equivalent. The ASCII value for 'a' is 97. ch++; This line adds 1 to ch, now it is equal to 'b' or 98. The code you provided does 3 things in that initial while() statement: * Read the next char value in the stream and assign it to ch * Check if that char is EOF - End Of File. If so, break out of the loop. * Check if n is > = 1000. If so, break out of the loop. The bit inside the {} stores ch in str[n], then adds 1 to n; the next time the loop runs, we'll store the char in the next slot of str. As for not busting a nerve, well, that's the eternal struggle of programmers :) Any time you hit a problem like this, take a few minutes away from it for a while. Looking at the problem again with a clear head can work wonders. If I'm really stuck with my code, I will leave it and work on other things for a day or longer (deadlines permitting). By the time I come back, I often have a fresh perspective and the answer seems obvious!"
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9xf80p | How do front facing "Virtual surround" speakers sound like they are surrounding me? | Technology | explainlikeimfive | {
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"The folds of your outer ear mean that sounds from behind you bounce off those folds before entering your ear. The effect of the extra bounce is that there's a short delay and that the frequency content gets modified. So we can instead modify the sound played from the front speakers to have the delay and frequency modification that the extra bounce off the folds of the ear would produce.",
"Not a real solution but my input: You have two ears which are two sources for your hearing. As long as you have more than one source for sound you can simulate sound above, to the left, to the right, and behind, though it would depend on the placement of the speakers. Stereo headphones can sound the same as a surround sound setup."
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9xf8q6 | Don't Open Source Softwares Basically Opens its Gate for Hackers? | Technology | explainlikeimfive | {
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"If your security is because no one can look at your code and understan how it work it is called [Security through obscurity]( URL_0 ) The problem is that id do not work. It has been rejected since the mid 19th century in the context of how locks could be picked. A real secure system should still be secure if someone know your code. If the code is secret you might find a but that is hard to fix and just assume that no one will find it without the code and leave it in. If it is open source you assume that any attacker have the code and you will write it with that in mind and do not leave holes. In some cases it might be a idea. If there is limited access to the system and not a software that you can purchase on the open market where a attacker can purchase it and examine the code and decompile it and examine it. So for military system or any that is tightly controlled keeping the source and design of the system secret make it harder to crack it. So it can be something to add ontop of other good security practice but you should never trust that it is enough. If anyone can get the software you should assume that it is the same as if they had the source code.",
"With open source, anyone can verify that the software is actually secure. With closed source, only the people developing it can verify that the software is actually secure. With open source, anyone realizing software isn't secure, but who wants to use it or has used it, is motivated to raise awareness about the weakness. With closed source, anyone realizing software isn't secure is likely either a developer who doesn't want to reveal this to any users, or a hacker who intends to use this weakness. That the source code is open is basically a guarantee of its quality. Anyone can inspect it, anyone spotting a weakness can easily prove it exists, and even fix it themselves, so if people are using it and don't seem to be finding flaws in it, you know it's been audited by hundreds or thousands of people, some way more competent than any of devs in any closed source program you use.",
"Yes, in the sense that an error in the code can be found by the hacker and exploited. But this is considered counterbalanced by the fact that people with more benign intentions can also find the error and report it to the developers, resulting in faster fixes and tighter coding overall. Closed-source is not really protected in the sense that you can't see the code(this is Security through Obscurity), only that you have to put in more work, which people with malicious intentions are more than willing to do.",
"Yes, but it also opens the gate for independent developers to make it more secure - this being how things generally work out.",
"Also, just as an add in. Open source software can be verified to not be doing something unethical. You can verify what is happening to data and where data is sent. Just because you can see the lock does not mean you have the key to get in.",
"On a side note, when it comes to security best practices, encryption techniques, and the like, open source (FOSS) *increases* security and robustness. The best cryptographic algorithms are publicly documented. The public academic scrutiny hardens them the same way a smith might harden steel by heating it repeatedly. Homebrew security algorithms and techniques are usually a Worst Practice."
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9xfuy3 | why does Google translate spit out completely crazy nonsensical things sometimes? | Things like this video: URL_0 (Not my video just an example of how google translate messes up sometimes) | Technology | explainlikeimfive | {
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"text": [
"It's still very much in development. It's all automated, so there's going to be some nuances that don't carry over. What you're seeing here is basically what the Google Search engine was like circa 1999. Google Translate uses algorithms that are based on UN Transcripts. Nearly every UN meeting is public record, and translated by competent humans into nearly every spoken language. That way no country is \"left out\" of the conversation. Do this for a couple of decades and you've got a really fucking boring but really long Rosetta Stone for the modern era. With that base, they can do a pretty OK job translating most formal writing that your grammar teacher would be proud of. When you start mixing in words that didn't make the UN minutes, it starts getting fucky. I wager extended debate on the \"tostostostostostostostostostostos\" issue didn't quite make the UN docket, so Google has to guess at what you're mashing into the algorithm. Given no other context, it's still giving you the best match for your translation, even if that high score is less than 1%. But, Google's Algorithm learns, as it did in 1999. It will recognize that \"tostostostos\" is a failure, but eventually many someones will want it legitimately translated, and give it some positive hits to learn from."
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9xg0w0 | Is it possible to manually recreate a video image simply by knowing what it translate into in binary? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Computers are just \"store numbers and perform math on them\" machines. At a conceptual level, there is nothing they do that couldn't be done with some paper and a pencil But computers operate on huge amounts of data very fast. So what they can do in a fraction of a second might take someone with paper and pencil, several days or even weeks to do.",
"In theory, yes, but it would be incredibly difficult. Most video is compressed in a way which is based on something called \"keyframes\". Those keyframes are stored in full and later frames are simply records of alterations made to the previous frame. So you might have a keyframe every second of a 30 fps video meaning 29 frames afterwards are simply modifications rather than being stored in full. This means in order to recreate a given frame you would not only need to know what your target frame is, but also what the key frame and previous frame modifications were, and even what modifications come afterwards so that your frame will fit properly. Performing those calculations manually would be an immense task. That said digital video is just binary so in theory any operation a computer does a human could do with sufficient time."
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9xgc32 | Why do so many websites feel the need to show a "This site uses cookies" disclaimer message? | This seems like a recent web trend that hasn't been around that long. So why are they doing this all of a sudden? What happens when you click agree? And what is the difference between that and just clicking the x on the message? | Technology | explainlikeimfive | {
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"It's a recent requirement due to the implementation of the [General Data Protection Regulation \\(GDPR\\)]( URL_0 ) in the European Union (EU) in May 2018. One of the requirements of the GDPR is that websites when cookies can be used to track a user (which is what most cookies are used for), [the website must disclose that to the user]( URL_1 ) so they know they are being tracked. You also may remember that earlier this year for about a month you received a stream of emails from every website you had an account on informing you that they had updated their privacy policy. Same reason: GDPR. Even though the GDPR is really only enforceable in Europe, many online sites have users and do business in Europe and those can be prosecuted under that law. The alternative would be for such sites to block any users who originate in the EU.",
"In 2011, the European Union passed a [directive] ( URL_0 ) that made it so websites had to inform users about the usage of cookies. This was done to give people more knowledge and control over what data websites were storing. This is a European directive, so technically, that only counts for when citizens of the EU access your site, but it is easier to just show the warning to all users. The cookie law is different from the GDPR which passed earlier this year (which is why suddenly every website updated their terms of conditions)",
"It’s also a law that was passed in California 5 years ago, so any website who wants to operate in California (i.e. pretty much every commercial website) has to advise visitors of their policy of using cookies.",
"This directive add nothing more than obtrusive messages. It don't explain what is tracked! That will add something. The explanations are long and non technical, after reading 2 or 3 tocs a patron emerge: thee never say what are tracking. They promise don't use your private data and don't track bla bla if go against the law.",
"Some pumpkins decided that because nobody reads or cares about legal notices, the best course of action would be to add yet another legal notice to the pile."
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"http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm"
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9xh21h | What is "portable" supposed to mean in Portable Network Graphics (PNG)? | I can't find any information by searching on Google | Technology | explainlikeimfive | {
"a_id": [
"e9se0eb"
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"text": [
"\"Portable\" here means that it is easy to implement to other computer platforms. Source: RFC2083 PNG is designed to be: * Simple and portable: developers should be able to implement PNG easily."
],
"score": [
7
],
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9xjley | What are “shadow profiles” and what are the direct harms? | Technology | explainlikeimfive | {
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"text": [
"In terms of social media, a shadow profile is when a company collects information about people who've actually never registered with that company's service and created a profile. But a company like Facebook can easily collect a *lot* of information on you anyway: it knows whose address books you appear in, it knows which websites you visit that have a Facebook \"like\" button, and probably some other ways as well. The harm is that this happens completely without your consent."
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9xk1zu | Why is it so hard to make good counterfeit currency if there’s obviously a method of making real currency? | Technology | explainlikeimfive | {
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"text": [
"The paper used in US currency, and similarly for many other countries, is not used for other purposes, which makes it extremely hard to mimic the exact paper used. Security features within the paper itself are either expensive and/or difficult to mimic. Watermarks created by variable thickness of the paper at ceartain points, embedded plastic strips that glow a specific color under UV light, etc. The printing process itself is also rarely used outside of currency, so you just can't buy it off the shelf a supermarket. Add in specialized inks with magnetic and optical properties and that's even more work. Cost: you aren't going to to be a profitable criminal if you spend more money making notes than you can get rid of them for.",
"It's hard to make counterfeit currency *profitably* Countries have implemented anticounterfeiting measures in their currency to make it harder to fake, this makes it harder for the country to make but they're doing it on a large enough scale it's fine Fake money is only useful if you can print money worth more than you spent to make it. If it costs you $25 to print a $20 bill then you're losing money, and even if it costs just $18 you're still losing money since not all the counterfeit money will pass the checks People can still make fake bills, it'll just cost them a lot more and make it not worth it for most groups"
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9xkeef | Why do many games have cut or unused content in their data? | Technology | explainlikeimfive | {
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"text": [
"There are a couple reasons why a game may have 'cut' or 'unused content' in the game data. Sometimes, such as the older Pokemon games, they added data to the game files in bulk, and when they decided to not use some, it's more efficient to simply remove the references to the code, thus 'abandoning' the data until it's discovered by unintended means. Other times, which is becoming fairly common (Destiny is a good example), the developer will have assets and areas within the game that are intended for expansion content. Instead of having to rework existing areas when expansion content is released, they simply have visible (such as a door or a nonfunctional elevator) or invisible geometry that's intended to keep players out of the areas that expansion content will use but aren't ready for use yet.",
"*Sometimes, such as the older Pokemon games, they added data to the game files in bulk, and when they decided to not use some, it's more efficient to simply remove the references to the code, thus 'abandoning' the data until it's discovered by unintended means.* Also, sometimes the whole programming system just \"works\". And especially when you're coming up close to the release date, you prefer to leave big parts of the code inside, because wanting to streamline it by removing unused code, might generate more problems than just leaving it in. Most of the time it's a big \"don't touch it, it works\", instead of \"I think we can do better\", especially near the end of development."
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9xkmq4 | how exactly does Apple Pay work? | Technology | explainlikeimfive | {
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"When you pay with a modern chip card, the terminal will read the 16 digit primary account number (PAN) on the card, which is stored in the chip. During this kind of transaction, the payment is verified at the terminal either manually via a signature or more likely via entering a 4 digit PIN number, the terminal will check the PIN is correct compared to the data on the card chip, and if it matches the payment is sent to be authorised or rejected by the bank and if you have enough funds it goes through. Part of the modern chip card standard (EMV) includes the ability to make contactless transactions. If you hold your card near a compatible reader, it will send the PAN information via a technology called NFC (near-field communication), this sends the same data as you would if you inserted the card. There is usually a limit for this kind of transaction, this may be a maximum amount, or require a pin after a few contactless transactions for security reasons. With Apple Pay things are similar, except it doesn’t sent your actual PAN, and you don’t need a PIN. Instead this uses something called tokenisation, where rather than sending your real data, it generates a unique single use number specific to that device and transaction. With Apple Pay when you register each card on the device, this creates a link to your card issuer and generates a new number called a device account number (DAN) which is unique to the phone or watch you added the card to and stored securely on the device, the bank also gets a decryption token they can use to securely check that your information matches. Note: This number is not the same as the number visible on the card. When an Apple Pay transaction happens the device verifies your identity via Touch or Face ID, and sends your DAN, the card expiry date, and a unique transaction number (dynamic card verification value) just for that payment. The dynamic number which is unique to each transaction serves a similar but more secure purpose as the PIN and 3 digit CVV code on the back of a credit card to prove the transaction is being made by the card holder, or in this case device holder. All this information substitutes for your real PAN number, and is checked in real-time by a token service provider at the bank of the store you’re buying from. This bank then sends the information on to Visa, Mastercard or AMEX etc. where they will decrypt the information using a key they received which was created when you registered the card on your device, they use this key in order to get your actual card number, then the transaction request is then sent to your actual bank/card issuer to approve/reject the payment. Assuming you have the funds, it goes through and you get to marvel at the fact this all happens in in under 3 seconds. Edit: spelling",
"Add your credit card a or debit card in Apple pay settings, it gets approved by your credit/debit card provider, then you can use your iPhone to purchase anything where Apple pay is accepted, here in Australia it's pretty much everywhere. iPhones 6 and above I think, have an RFID chip which is needed for Apple pay as you just 'tap and go' by placing your iPhone very close to the register/keypad with RFID. edit: NFC not RFID apologies.",
"I apologize if this has already been mentioned, but another detail about Apple Pay is you do not need a data connection. For example, American in U.K. The best way to use the London Underground is with Apple Pay, even if you have your phone in airplane mode. You will get the best rates and no need to buy tickets at the kiosks.",
"When the contactless terminal is expecting payment, it sends out radio waves. Contactless payment chips in your phone or payment card listen out for signals from this and activate when they detect them. They have a brief secure chat (again via radio waves) telling each other who they are - the chip in payment card tells the terminal which card it is, and the payment is then authorised (or not) in the same way as any other payment. With a phone (android/google pay works similarly) you can turn the payment chip on and off which you can't with a card - ie you need to unlock the phone to use it. This is why the payment limit is higher with a phone than with a normal contactless card payment."
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9xm312 | How can the EU hold American companies like Youtube liable with it's new copyright laws? | Technology | explainlikeimfive | {
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"text": [
"When they do business within the eu they are bound by eu law and vice versa. There are also reciprocal agreements wrt copyright laws, such that we agree not to infringe things that have been copyrighted in each other’s territories within our own territory. Edit: When it comes to websites and such, eu laws have no bearing over what is displayed by a non-eu website outside of the eu but they certainly do when a non-eu companies’ website operates within the EU.",
"Basically, the philosophy around international copyright is \"treat other countries' copyrights as you would want your country's to be treated.\" Several treaties bind most countries to act in accordance with this maxim for most works.",
"To enforce its laws, the EU can: \\-Block YouTube from operating within the EU \\-Make YouTube pay a fine if they break the law. And if YouTube refused to pay the fine, the EU could seize any assets that they have within EU borders (buildings, bank accounts, etc.)"
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9xnsss | Why do special effects in movies and tv shows cost so much? Isn't it just using a program they already own? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Buying the program is cheap. Using it takes time. The time of many highly skilled people...",
"special effects isnt just a \"program\". Things have to be custom made for every shot and frame. vfx artists need to create everything that a shot needs as well as animate it. they use multiple different programs and theres several people that perform different tasks in order to complete a visual effects shot.",
"I went to school for animation, and had some classes in vfx. We had a 10 week period to film a ~5 minute short and put in special effects. Most of us turned that project in late, because even for a 5 minute film, filming it and doing all the visual effects within 2.5 months was a really tight timeline. Now take that 5 minute film, and extend it out to a 90-120+ minute runtime for a feature-length film. Now take multiple artists with years of experience under their belt being paid $75k+ a year to do this. And you have a big chunk of the cost of VFX. While yes, the companies employing visual artists will likely have licenses to the programs you'll need (there are a lot of them, primarily though Adobe AfterEffects and probably either Maya or 3DS Max for some of the more complex 3d stuff, as well as Photoshop for texturing and Premiere for stitching everything together into a single coherent film.) those programs don't just do all the work; it takes several people weeks and months to make every art asset and animate it and do the special effects, etc. etc.",
"\"Owning\" software is mostly a thing of the past, when it comes to high-end commercial software. Instead, you pay an annual licensing fee. The 3DS Suite, used in many high-budget Hollywood films, is $2,300 per person per year. It is very likely used in conjunction with other software which will have its own licensing costs. But as others have pointed out, visual effects is a high-skill job which is very time consuming. The majority of your budget (as with most budgets) will go towards paying people. If you have a six month post-production schedule with a team of 20 doing VFX, that's easily 7 figures spent on salaries. There's other stuff, too. VFX is not all in-software, real-life work with cameras and traditional special effects (explosions, lights, complex moving equipment, etc) is usually blended in. If you need sound effects to match, you either have to create your own - which is more software, more salaries, more equipment - or pay to license existing work."
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9xpkw6 | Why and how do those thin cracks on the freeway concrete that run parallel to the dots and lines make my car swerve when my tire moves past or is running on top of it? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Your tire is made of rubber and inflated with air. If part of the tire has air beneath it while the rest is pressed against the road by the entire weight of your car, that part above air will swell out, making the radius of the wheel bigger at that point. Bigger radius means that part of the wheel's surface moves faster, which means that if it touches the side or bottom of the crack it'll push the side of the wheel it's on forward. This is a tiny difference, of course, relatively speaking... but when you have a ton or two of metal going at a hundred kilometres an hour, it doesn't take much of a difference to feel it."
],
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9xq0qw | How does the ‘undo’ feature work on computers? | How does it (CPU) know the last used command? How does it know what command will undo the previously done command? In certain applications, how does it know to treat a series of commands as ‘undoable’, like deleting multiple words as opposed to single letters? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"\"Undo\" is typically not a function of the CPU, it's typically a function of the program or app you're using. The app keeps track of what you're doing, and the \"work\" is kept in the computer's memory, including the order of the steps or mouse clicks that you did. So when you click the undo button (the button is a feature of the app), the app just goes backwards through your recent actions and reverses them. Once you save your work to disk, typically the undo options disappear; the app saves just the data file, and doesn't save the mouse clicks or keyboard commands, so it can no longer keep track of what you did.",
"Undo feature is performed by every app individually. So it's up to app developers how to implement it. Typically there is a set of predefined opposite actions that user can perform and undo.",
"There's a term with computers called \"the stack\" or a stack. It's used to show how memory works in some cases. Commands go into the stack like a stack of plates. One on top of the other. Want to remove what just happened? Take the top plate off of the stack."
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9xrpte | How do sites like 1Password not create the problem they are trying to remove? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"The problem they are trying to solve is people having to remember *multiple* passwords. For their system you only need to remember *one* password. So it is solving that problem.",
"I can understand where your question is coming from: If you use the same password for a bunch of sites vs. one password for a service which logs you into a bunch of sites seemingly are equivalent because in the end it is still just the one password. But the difference here is that each of the accounts at various sites have their own, unique password which is stored on the service. Previously the problem was that someone compromising any of the sites and finding out your password would then know the password to all the other sites you use. But now any of those sites being compromised doesn't give them access to everything, only getting the password to the password service account would compromise everything. In that sense it narrows your risk.",
"The main ways they solve the problems are offering a database for complicated and extremely secure passwords that would be very hard to memorize. And then the other pro is their secured and encrypted storage of said passwords making a safe place to keep it on hand yet unreadable by outside elements. 👍"
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9xtjxh | What does it mean when a computer crashes? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Computers follow orders, and they do it (for the most part) blindly. If an impossible order is given (like when you send it looking for something that doesn't exist), it crashes. Similarly if an infinite order is given (you can literally order your computer to loop infinitely, and it'll get stuck in the infinite loop), the computer will \"crash\" in the sense that 100% of available resources are tied up in something literally infinite. In the most general sense, a computer is the ultimate grammar nazi combined with the most obedient servant. Grammar error in your code? Computer says \"This whole book is unreadable\" and your program crashes. If the grammar error is in the *operating system itself*, then the computer crashes entirely unless the programmers also included a path around the crash (programmers commonly create orders for the computers that are essentially \"Try to do A, but if that creates an error, then do B\")."
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|
9xw5af | how the hashing function works and generate hashes ? | i want to know how the hashing functions work ? and how it transfers the variable length of password to fixed length of hash ? for example (abc , abcdef,abcdefghi,...) will generate the same length of hash | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"There are many different hash functions (infiniely many). A very simple (and verybad) one would be to simply cut off the input at the desired length and pad it with zeroes if it's too short. A somewhat better hash function for text is this (used e.g. by the Java programming language): take the first character's ASCII value multiplied by 31, then add the second character's ASCII value and multiply the total by 31, continue until the end of the text. The additions and multiplications are modulo 2^32 so the result will be a 32 bit integer. For passwords, you want to use a cryptographic hash function, but those are generally also just carefully chosen combinations of many simple operations, usually involving modulo arithmetics, boolean operations, permutations and substitutions."
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9xwmru | How does your clock keep working on your phone even if you run out of battery for weeks? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Your phone updates it’s time when you connect to a cell tower. You can see this if you’ve ever crossed time zones out in the desert or whatever. Your phone will have the old time zones info until you get signal again.",
"The clock circuit takes nanowatts to run. Really microscopic amounts of power. So even if you phone is dead, it can still run for years with whatever the battery has left. In the event the battery is disconected, when it turns on, during its boot up sequence, it will ask the network tower the time, so by the time it's on and you can see the apps on the screen and whatnot, it already got the time"
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9xyjmy | Why do batteries lose charge when they haven't been used before or not for a long time? | Technology | explainlikeimfive | {
"a_id": [
"e9webkv"
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"text": [
"Because batteries are chemicals and for power is generated through a chemical reaction. Over time, the chemicals can break down and be less effective also the battery's chemical reaction will happen slowly even when not being used."
],
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8
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9xzdsb | How does an electron microscope work? | Exactly, that. How does an electron microscope work beyond the obvious that it uses electrons somehow to generate an image. | Technology | explainlikeimfive | {
"a_id": [
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"Afaik: Electrons are smaller than light particles so it can read and get into smaller detail than light can. Imagine trying to figure out which side of a die your looking at by rubbing a tennis ball on it vs a sharp pencil. And then for the actual data: I'm pretty sure it's kinda like echolocation. You shoot electrons at it and measure the time it takes to bounce back to get depth and then a computer constructs a greyscale image"
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9y307w | Why do passwords have an upper limit for length? | Why does password length matter? Aren't they just converted into a 32-, 64-, or 128-bit hash for storage? Is it due to the speed of the hashing function used? | Technology | explainlikeimfive | {
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"Real answer is developer preference, as past of the password dialog properties one must specify a max size but as you mentioned if the password is handled correctly it is used once and only the hash is stored. Since the hashing of the password is a relatively infrequent you could use a long ass password and shouldn't make a big difference. On some other places I am pretty sure they store the password in plain text or use some silly ofuscation algorithm so they place a length limit to save on database size."
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9y46ll | how do people even get STARTED with hacking like you see the professionals do it? | Technology | explainlikeimfive | {
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"Learn a language like python/java. Move on too ruby/C+/whatever you want. Get really good at that. Essentially all hacking is, is finding a weak point in coding. It's not like what you see on tv.",
"Usually they get a job in network security after getting a degree in networking. Like a locksmith, you learn how things work and are put together first then probe and see how things react.",
"TLDR; be prepared to spend a lot of time learning, building labs, reading and testing against yourself. The actual \"hack\" itself is often a footnote. I think a lot depends on whether you want to be a white hat (ethical) or black hat (bad guy) hacker. Either way, you START by hacking yourself and you need to be prepared to spend some serious time learning the skills. As social engineering (the art of gaining access to information through gaining trust or confidence) is one of the most successful attacks, start there. How are you vulnerable or gullible to handing over private information without any computer/network intrusion? This stuff is covered extensively in many \"hacking\" courses, as I will mention later. I imagine your question relates more to computer/network based hacking, so I'll move on. A lot of \"script kiddies\" out there just copy other people's work and use their examples to exploit the weakest in society. Just like exams in school, copying is fine for the test, but in real life when something goes wrong you won't know what to do to either cover your tracks, or prevent being attacked in return. Assuming you have some basic command line and scripting skills, install Kali Linux distribution on a old computer or virtualize with something like Virtual box or VMWare. You won't use the majority of the Kali toolset for some time, but it's worth having at your fingertips. Courses like GCIH (GIAC Certified Incident Handler) will often provide their own Linux distribution with appropriate tools for learning to hack. Get a book like CEH (Certified Ethical Hacker) or similar SANS GIAC courses and just dive into some of the early exercises. The courses are built for someone with fairly decent IT and Networking skills, so if you don't have those, you can acquire them through other courses, e.g. CCNA, Linux boot camps, etc. You can then set up some fake accounts on websites or local accounts and files on another computer that don't contain any private information and try to exploit those. Setting up separate machines and accounts to be hacked might seem like a pain, but once you've exploited them, what's to stop those hackers out it in the wild doing it again? Plus, having a lab is important if you're serious about learning. I can't overemphasive how important it is to prepare. People who prevent attacks spend most of their time preparing defences and processes, so it makes sense that a hacker spends equal or more time preparing their attack. The fact is that the Hollywood interpretation of \"hacking\" is far from reality. Most of the time is spent learning about the tools, targets and defences, with the actual \"hack\" being a footnote. Good luck out there and stay safe!"
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9y7kvk | How do we get such detailed, beautiful pictures of objects so much further away but Pluto was just a blurry blob until a year ago? | Technology | explainlikeimfive | {
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"We may get beautiful pictures but they aren't exactly \"detailed\" in the same sense. Pluto is small and moving relatively quickly, and while we may get a seemingly detailed picture of a nebula the details shown aren't actually any more than with the pictures of Pluto. For example suppose you wanted to take a picture of someone several miles away. All you get is an indistinct blob. But then you take a picture of a mountain the same distance away and it looks great, all that detail which is visible. Yet while the picture of the mountain looks better both of the photos have the same resolving power at that distance.",
"We don't have any detailed pictures of objects farther away than pluto. Something like the [hubble deep field]( URL_0 ) is, first off, not exactly detailed (those smears of light are all entire galaxies). Also, it is imaging **very** massive, **very** bright objects (again, entire galaxies) rather than a small, dim chunk of rock and ice."
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9y88w2 | How are porn sites able to identify certain positions/scenes within their videos and categorize them accordingly? | Technology | explainlikeimfive | {
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"They’re tagged by the user uploading them, no?",
"This is of course manually done by the people who upload it. It would easily be possible to program a bot for that. But humans are cheaper. Uploader do it for free for their own benefit."
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9y8k28 | Why does the battery life of brand new phones crater after a few months? | This has happened with every smart phone I've e ever owned. For the first few months the battery life will be as advertised. After a few months the phone can't even make it through half a day. My type of usage remains the same. For instance, I recently got a galaxy S9. Used to last two days between changes. Now lasts about 6 hours. Why does this always happen? | Technology | explainlikeimfive | {
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"Batteries get worse and hold less charge the more you use them. So over time it can't store as much charge. You could also have a lot of background stuff happening information as you download more. Especially if you don't close stuff.",
"it's something called planned obsolecense. Manufacturers make things to last only a certain amount of time before failure occurs and this is known. If you bought a car that would last forever then you would never buy another car. Items are tested before putting them into production and they know exactly how long they will last before critical failure. Batteries could be made to last significantly longer but then you would never buy another battery.",
"Older cell batteries were NiMH and benefitted from full discharge. New smartphone batteries are lithium ion and are damaged with a full discharge. There seem to be conflicting answers on what the best charging procedure for extending the life of the battery, but sufficed to say that fully draining or over charging is bad for them. As far as I’ve read keeping a lithium ion battery charged around 80% is best for its health, which I believe means more shorter charging sessions. Could be wrong though. My IPhone 6 battery lasted about 3 years until it needed replacing and the charge was reasonable leading up to about 2-2.5 years. Are you using more data where you are now compared to when you first bought it? Leave your Bluetooth on? Brightness all the way up? Background app refresh on? Battery saver function turned off? There are a lot of ways to keep your battery from draining too fast. Do some research on your particular model too see what can be done."
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9yco4q | If you censor private details from your puctures by blurring or adding a black box on top, could this ever be removed by person with a powerful computer? | Technology | explainlikeimfive | {
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"Adding a solid 100% opacity color will hide anything underneath, and there's no way to retrieve that hidden information. Blurring can potentially be reversed.",
"If you add a black box with 100% opacity, no. Image formats store specific colour information for each pixel (even less so if you're using any form of lossy compression). Once you change a specific area of an image to black and save it (as a flat image, without any layers), there's no way to recover what was previously there.",
"I would think so. I remember reading a news story a little awhile back about police using some sort of technology to unswirl a guys face in a photo to identify him. Dude was posing with underage kids. Girls I think. Either way it was child porn photos being shared online and that’s how they got him. Edit: Here’s the story: URL_0",
"Depends. A black box removes information: > I am a ___ grasshopper You can't figure out the missing word. This is like a black box over the image. No way to retrieve it. A blur, if done in a mathematically predictable way, can be reversed as in: > I am a 214 grasshopper If you know the algorithm used (A=1, B=2, C=3...Z=26) you can reverse it and find the missing data. This happened to a pedophile using a Photoshop swirl effect, it was mathetically reversible. Tl;Dr use a colored box, can't go wrong. Esit: reading this over it looks like advice for sharing questionable material. That's not what I mean. You know."
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9ye94b | How is it that a USB cable/port can not only be used to transfer data between devices, but can also be used to charge a device? | Technology | explainlikeimfive | {
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"The USB connector includes connections for power as well as for data, so that devices like mice and keyboards and storage drives and others don't need an external power source.",
"Originally the USB included a bunch of connections to transfer data as well as some pins to transfer a small amount of power. This was not meant to charge anything, it was just enough power to run the device, so your keyboard or mouse didn't need an extra power cable to function. People making devices found more and more uses for this power connection so in subsequent version the amount of power that could be transferred was increased. More and more devices could be powered by the power of USB alone. Some makers even figured out that if you just used to power connectors and not the data connectors the computer would automatically give you the standard amount of power and you could for example power small desk fans per usb. When smarter phones became more common they at first had all sorts of connectors for power and later data. Eventually everyone standardized on some form of USB or other (mini, micro etc) which could connect the phone to the computer so it could be treated as a USB stick with data on it, but also function as a computer itself if you wanted to connect some device to the phone. This also could provide some power charge. At first makers were limited to the maximum amount of power that the normal USB standard gave them, but eventually they created USB chargers that could communicate with the phone via the data ports and ask it how much power it can stomach and gave it that much power so it could charge faster. Nowadays with USB 3 and USB-C (and USB-PD), USB has become a pretty much everything connector that can be used to power everything and transfer data between all sorts of devices."
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9yetfu | Why is the task manager so much “better” at closing applications when compared to the task bar? (or the close button) | I hope I was able to word this well enough... | Technology | explainlikeimfive | {
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"The task bar sends a polite request to the application to close itself. This works nicely most of the time, and is what you want. For instance it gives the application the possibility of asking if you want to save the current document, or to ask if you really want to quit. The task manager can send an unconditional kill request to the OS itself. The application won't get the chance to do anything about it. This is great if the application is malfunctioning, but not the sort of thing you want if you would like to be asked if you wanted to save those 5 hours of work first. So on the whole it's useful to have that function a bit hidden away somewhere you won't accidentally hit and cause you to lose hours of work.",
"Because using the close button or task bar is getting the software to close itself down. Using task manager is using the operating system to stop a process. Kind of like the difference between using the shut down button in your start menu vs force shutting down by pressing and holding the power button."
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9ygs7d | Why corn was selected as one and only crop surviving in those conditions in Installer Movie, Is there an explanation to it? | Technology | explainlikeimfive | {
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"Its a plot device. The movie is a US centric movie and wanted to invoke the good old corn farmer for nostalgia. If it has been soybean or rice, it would be harder to invoke audience connection to movie",
"Everyone knows director Christopher Nolan actually planted that corn and sold it for a profit after filiming, right?",
"Not a farmer here but would like to be one and interstellar is an amazing movie, I think corn can be used in the more ways than any other plant (fuel food animal feed ect) and was the easiest to grow.",
"The idea is that a series of crop blights destroyed the crops in sequence: Corn was the lucky one and hadn't blighted yet. It worked narratively as a convenient background as well as demonstrating how screwed everyone was even if they didn't notice: they were sustained on a single monoculture that would collapse suddenly when a corn disease hit. It ties into the theme that it appears like humanity would persevere, even when their existence is fragile as glass: Remember the government want more farmers like they can corn yield their way out of ecological collapse."
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9ym8lg | Why do phones and computers get slower over time? | Technology | explainlikeimfive | {
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"They don't. Hardware remains exactly the same. What changes is the software. Software continues to progress, and part of the progress of software is that it demands more computing resources to do more interesting things for the user. When you put _new_ software on _old_ hardware, the old hardware doesn't have the same resources to provide to that newer software. If you took, say, a 2012 MacBook and did a clean install of MacOS Mountain Lion (which was released in 2012) it would run as fast today as it would have when it was new. However, if you take a 2012 MacBook and do a clean install of MacOS Mojave (which was released about two months ago), it'll run, but it'll likely be pretty painfully slow. The hardware (the MacBook) hasn't changed; what has changed is the software (MacOS).",
"1) software gets more CPU or RAM intensive as devices get more CPU and RAM intensive. 2) Apple wants you to upgrade."
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9ymgr6 | With technology generally moving pretty fast, why aren't [rechargable] batteries improving accordingly? Or are they and we're still pushing their limits? | Technology | explainlikeimfive | {
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"They are improving constantly. Today's batteries are *far* better than those of 15 years ago, and many further technologies are growing in the labs. But frankly the chemistry is inherently hard — nature doesn't care that we want batteries to be efficient and fast.",
"Batteries are much better today than ten years ago, but you're always pushing the boundaries of what is chemically possible. Besides that, batteries as opposed to most technologies weren't improved much before the 1980s - the lead-acid batteries we use in cars today are basically the same as when they were invented in the 1860s and basically the only improvements that came after were Zinc batteries in the 1890s and further improvement to those ubiquitous alkaline batteries that are everywhere in the 1960s. So battery technology is currently catching up with all sorts of developments in lithium and other technologies. The reason for this lag in battery technology is in my opinion that lead-acid batteries were just good enough for most applications, and there simply weren't that many applications that warranted increased research spending - up until the 1980s electronics simply weren't small and portable enough where it would be useful to make them battery powered; and since combustion engines worked very well electric cars didn't really play a role either.",
"There are some batteries, and capacitors as well, in labs right now that blow current technology right out of the water. It takes time for things to get from the lab to commercial production though, as the whole manufacturing process has to be engineered as well. I am more interested in the capacitor tech, imagine being able to have your phone run all day or longer, then recharge it in seconds.",
"[Aluminium batteries]( URL_0 ) have potentially 2x capacity of Li-ion batteries, but the last thing I've read about them is that they tend to explode, which is not very good for a real-world usage.",
"One major thing is that as batteries get better, companies want to do two things: use more power to make their product better; make the battery smaller to reduce weight or size. So even as battery tech improves, the actual longevity of your devices are going to be optimized for an finite amount of time/use.",
"Moores law which is already coming to an end was essentially possible because we were able to shrink transistors by half their size every year effectively doubling computing power. We literally put twice the transistors in the same space and did twice the work with them. Batteries aren't built from transistors, they're chemical machines not physical. We can't compress the components that store electricity and just put twice as many in the same box. We have to redesign in much more complicated ways to improve them.",
"In addition to the other responses here specifically regarding batteries, with improvements in storage, processors (and batteries), developers have lost some incentive to really streamline their code. 20 years ago, it was important that programs took up very little space and were as efficient as possible because computing power was expensive. Nowadays though, a 1T hard drive isn't all that expensive and most modern CPUs can easily handle what the average person needs to accomplish so there's not much push to try and eek out those last drops of efficiency (which would extend battery life as a byproduct). I work for a software company, and even within our own code there's *boatloads* of stuff that should be culled out. Why haven't we? Well, we've got an ever growing list of to-dos and quite frankly, it works as is and would take our entire dev team at least a few months or more to refactor everything as efficiently as possible. It's just easier to tell people it'll take up a little more space on their hard drive, and they may have to wait a few more seconds to get data."
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9ymz3v | . How does the FCC’s approval of SpaceX launching 7,000+ satellites into orbit affect cell service and WiFi on a global long termscale? | SpaceX recently received approval from the United States Congress to launch over seven-thousand satellites into orbit to create a sort of global mesh for networking. How will that have an effect on cell service and WiFi providers like Verizon and Comcast? Will everyone on the planet have free internet by the end of the century? | Technology | explainlikeimfive | {
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"> Will everyone on the planet have free internet by the end of the century? Likely no. But perhaps you can have internet access any where on earth with a good connection for a relative low cost. The network called Starlink cost money to operate and SpaceX like to make a profit. So is it not that likely that we have free networks. On the other side there are a lot of free services online that is free but have advertisement etc. It might be a popular way to pay for communication networks. There have been attempt with cellular plans that is ad based and require to you look at videos but they are not that successful so we might still pay for it in the future. The first market they will target is internet access where in location that have limited access today where you have to low population density to build fast ground bases system. The idea is 12000 satellites in the end of 2020. If they cover all of earth evenly that would still require each satellite to cover a area of 43 000 km^2. There vill be less coverage over the poles so lets say 25 000 km^2 per satellite. That is a square of 158x158 km. That be a limitation in a city. Transmitting to a satellite is a city is a problem as high building are good at blocking signal and the mobile networks have a lot of small transmittor so you get cover. They talk about controllable antennas so you cover the areas with a lot of people better but there will be problem. There will be a limited number of satellites visible in the sky above any location and we human like to congregate in large cities. So the network will never replace ground base connection in cities. Fiber optical cables might be expensive to install but the cost to operate them with high throughput are very low. So most internet connection and the backbone it is build on will be fiberoptical cables for the foreseeable future. So I suspect that it might be a good way to supplement ground based system and a way for locations with bad connection today to have good internet. But as a replacement for cellular and wired internet that we use today would not works On the wikipage URL_0 I found this > The system will not compete with Iridium satellite constellation, which is designed to link directly to handsets. Instead, it will be linked to flat user terminals the size of a pizza box, which will have phased array antennas and track the satellites. The terminals can be mounted anywhere, as long as they can see the sky. So it will not replace cellphone but work for building and vehicle. I suspect that it will be great for internet access to airplanes.",
"We won’t know until we learn more about the connection and economics of the situation. We could come up with tons of scenarios, but until stuff is more released we don’t know. Hell we don’t even know if any of the companies attempting to do this type of stuff (it’s more companies than just SpaceX, SpaceX just hits the PR/marketing harder than the others) will be viable or even actually put up their constellation of satellites. Wait and see. Not enough info yet."
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9yn4xo | How does electrochromic glass work? | I sometimes see the occasional rich villain / antagonist in movies have these fancy windows that can change tint. I, more recently, noticed some videos and gifs of this and is it even real? If so, how does it work? | Technology | explainlikeimfive | {
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"Oh boy did we luck out. Inventor/patenter of a Smart Glass technology here. Yes it’s real. You can even see some as your own personal villain on the Boeing Dreamlimer seats. There’s a lot of different kinds. 1. Electrochromic (EC) 2. Suspended Particle Device (SPD) 3. Polymer Dispersed Liquid Crystal (PDLC) 4. Polarization Based (mine) Since you asked about EC, it's kind of the worst of all 4. It's very expensive. It switches from clear to dark when power is applied. You have to keep applying power to keep it switched. You see it most often in rearview mirrors of luxury cars. It works essentially as a reversible chemical reaction. The reaction oxidized a violagen. The electricity reverses the reaction. It's basically a battery that changes color when charged. SPD is what's in Dreamliners. I know the guy who invented it. He made... a lot of money. SPD is a gel that gets darker when a current is applied. Essentially, the gel has a dark ink suspended in in it and when you apply a current, all the particles line up in columns and hide behind one another. PDLC is based on a liquid crystal—a material that also lines up with an electric field like the needle of a compass. Millions of them in the gel between the glass make the difference between a clear material and one that scatters light in a bunch of different directions — making it appear frosted. This material is fairly inexpensive and you can find it in law offices and some high end hotel bathroms. My technology was really simple. It relies on polarizers to allow or block light. Light has an orientation to it. A polarizer filters out all horizontal or vertical light. If you stack two of them, then rotate the second, they cross and the window goes dark. Instead of rotating, you can create a window that darkens when you slide one an inch up or down, by alternating strips of horizontal and vertical oriented stripes. Now, if instead of vertical and horizontal, you add the angles in between as a sinusoidal pattern, the window will go through shades of gray all the way to blackout."
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9yn9h7 | Why are CPU speeds measured in Gigahertz (GHz) and RAM in Megahertz (MHz) when they are usually similar? | For example, a CPU like the Intel Core i9 9900k has a base clock speed of 3.6GHz, or 3600MHz. A DDR4 RAM stick (for example) can have an operating speed of 3600MHz, or 3.6GHz. Why, then, do we measure CPU and RAM frequencies in different terms when they are already both similar? | Technology | explainlikeimfive | {
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"It was mostly marketing. In the days when CPUs started achieving GHz speeds, the “GHz” portion was heavily, heavily advertised as being ultra crazy fast! Look we don’t even measure it like those other puny CPUs! When GHz speeds came out, the CPU market was a fierce advertising space. RAM on the other side took far longer to achieve GHz speeds, and by then, convention of RAM speeds was pretty established to be described in MHz, such as DDR3–800, DDR3-1600 etc. RAM doesn’t get the kind of marketing that Intel and AMD throw at their CPUs and few consumers even understand (or care) what speed their RAM is. There’s actually a different way to spec RAM as well, but it’s lesser upfront/customer facing than the one above and generally not important except to some heavy enthusiasts."
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9ynf45 | How do computer monitors scale lower resolution inputs and why does it look so much better than software scaling? | I was trying out some programs to make my old game, which has impressive 1024:768 as the biggest resolution in the settings, to run at my native widescreen 1080p resolution in letterbox mode (with black bars on the side, usually it's all just stretched put and ugly) so it would look cleaner and not mess up my system's resolution, and when I compared that to what my monitor does, the difference was astronomical. Even after trying out different scaling options (linear, nearest, etc) the results could not match up to the crispness of monitor scaling. So what do monitors/graphics cards use to scale images so well and clear, and why can't that be done through software? | Technology | explainlikeimfive | {
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"It can. It just takes some carefully-crafted edge/sharpening filters and stuff like that. Here's a pic showing an example of what is going on: URL_0 So it absolutely can be done in software and it's used all the time, especially in old console emulators. Nearest/Linear/Bilinear/etc are all extremely basic scaling algorithms that don't do anything to try to preserve the original aesthetic of the image. They will basically make things look blurry that aren't supposed to be blurry because the simple algorithms smooth out what it thinks are low-resolution edges and aliasing. A lot of monitors and especially TV's in particular try pretty hard out of the box to make images pop better in all different kinds of ways and have tons of weird/proprietary filters. Ways that also tend to add quite a bit of latency unless you set it to \"game\" mode which makes it go straight back to looking like shit, because it's basically just doing a Nearest Neighbor/Linear/Bilinear mode, for example."
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9yny8d | Difference between TAR and ZIP files? | Technology | explainlikeimfive | {
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"A TAR file is a form meant for a Tape ARchive - it just stores the files and directory structure as one file in a standard format, no compression. A ZIP file is a newer format, combining compression and archiving. Most tar files will be served as .tar.gz or tar.bz2, which means they were put into TAR format before being compressed with gzip or bzip2. For historical reasons, Unix and Unix-like systems tend to use tar files (they preserve the more-complex file permissions) with later compression, while PC systems tend to use zip. There are other systems out there, some of which were multi-system. There's a [Wikipedia article]( URL_0 ) giving more detail, if you like. In the 1990s, you could expect to find a wide mixture of compression and archiving formats, but these have pretty much won out (except DMG files on Mac OS X, and RAR files for big things that need to be split into multi-part files). Can't recall the last time I saw an ARJ, though it was one of the better compressors in its DOS heyday.",
"Specifically, TAR is just a format for grouping a bunch of files into a single file, and does not offer compression by itself, although it is almost always used with a compression utility like bzip or gzip (which by themselves, only compress single files)."
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9yofju | Why is Windows NT so highly regarded and used in network IT to this day? | I asked a friend who couldn't quite communicate their reasons, other than that there hasn't been anything like it since? Surely Microsoft would try and make a similar product for networks? | Technology | explainlikeimfive | {
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"text": [
"If you're still using Windows NT to this day then you have some pretty serious problems... It's certifiably ancient by IT standards. Windows NT is the platform upon which the follow versions of Windows were built. The NT Kernel laid the groundwork for what became Windows Server, Windows XP, and Windows 7+ So in that sense, yes we are still using Windows NT to a degree. In the way that we are using it's children.",
"So for clarity, the current windows versions, Since Win 2000 (business/server) and Win XP (general consumer) are all actually built off Windows NT. It’s alive and well. The more specific “server” version(s) after Win 2000 (which was essentially just the next version of NT, NT 5.0) were renamed “Windows Server” and continue to be in heavy use, they are still NT."
],
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9ys1vs | how does a gif or a jpeg lose pixels as it gets shared more and more? When you copy it doesn’t it copy the whole file? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"A lot of social media sites run compression on uploaded images to save space on their servers. If you upload a picture to Facebook or Twitter it may lose fidelity. If someone then saves it and uploads it again, it may lose more. Editing and resaving in a compressed format will also lower fidelity. Repeat until you've deep fried the meme.",
"If you just copy the file to someone else or a different storage location, then no, it doesn't lose anything. However if you do something like opening in an image editor and resaving it then it goes through another cycle of encoding, possibly losing image information depending on the compression factor applied.",
"If you copy the entire file as is then it doesn't lose anything. It does lose quality if you open the image and then save it again. For example if you take a screenshot of the image instead of saving the original image file, or if you open the image in an image editor to add a title and then save the edited image."
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9ysc9a | By what mechanism do fitness trackers monitor sleep patterns? | Are fitness trackers an accurate way to measure sleep patterns? How do they work? | Technology | explainlikeimfive | {
"a_id": [
"ea3n5ak"
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"text": [
"Fitness trackers generally just use an accelerometer to detect motion in your sleep. Basically it detects how much you move at night. Stuff like a fit bit advertise they do it, but are generally considered pretty inaccurate and poor representations of sleep tracking, compared to more scientific and accurate equipment and aren’t taken seriously. But consumers generally don’t know or care and take it as the truth so it makes for a great feature to advertise on a Fitbit , even if it’s accuracy is pretty questionable"
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9ysp4r | How does a phone know how much energy is left in the battery? | Does it measure the output voltage or something? | Technology | explainlikeimfive | {
"a_id": [
"ea3pdce",
"ea3rgri"
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"text": [
"As a battery loses charge, it's output goes down slightly, and a phone is programmed to weigh it's current consumption rate compared to what the battery is putting out.",
"It measures the voltage, yes. But voltage is an imprecise measure. On lithium batteries it stays [nearly flat]( URL_0 ) for a long time. So it also measures current flow. As batteries degrade the estimation can get out of whack. That's why sometimes you can see a phone that shows 15% left, then suddenly it decides it's completely out of battery and shuts down."
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9ytj44 | How does GPS work in poor weather conditions when satellite radio and TV don't | Technology | explainlikeimfive | {
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"text": [
"In order for GPS to work optimally, your receiver needs to have 4 satellites connected (some models will indicate the number on the display). While less than optimum, you can get location with fewer than 4 satellites, but the accuracy will be diminished Having to connect to multiple satellites for GPS provides a redundancy that can overcome some situations like weather; if you lose connection with one of the satellites, the other 3 can still provide information. When you connect to satellite radio, you're only connecting to one satellite, which provides no redundancy for the signal.",
"This depends whether you are talking about GPS or A-GPS. A-GPS is Assisted (Or Augmented) GPS and uses data from cellphone towers and Wi-fi to give you quicker access to GPS and is used particularly in cellphones to provide you with what is really a hybrid positioning system. True GPS on it's own requires you to not only lock onto a satellite but to also download packets of information required to use the positioning system and typically takes at least a minute to do so. GPS on it's own requires clear line of sight and a constant lock on and therefore will typically not work inside buildings or even when driving between tall buildings. However the GPS signal itself is so basic that atmospheric conditions seldom manage to disrupt the tracking.",
"GPS signals are sent on different frequencies/wavelengths and are able to go through clouds without losing their signal/data as much as satellite radio. They also just continually broadcast a simple signal that contains their location and the current time. If your GPS receiver doesn't pick up a signal due to interference, there will be another signal very soon. Satellite radio is broadcasting a stream with lots of data. If you miss some of it, you can't listen to the parts you missed."
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9yuwx1 | How do video game display mechanics work? | On my PC, FPS shooters (COD BO4) get's between 90 and 110 FPS. I understand how the eye works and all that Jazz. What I really want to understand is how things are updated FROM the PC side. How often is my characters information / position etc updated. By having powerful hardware I get the 110FPS, but is it actually giving me any more information or are some of those frames duplicates because the game hasn't displayed the next frame? & #x200B; Does that make sense? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"This is highly dependant on the game. & #x200B; One semi-common option that some developer's do is tie the updates to the framerate (and lock the framerate when they do that). In those cases, you won't get a higher FPS with a better PC because the game is artificially limiting the rate to keep the physics working as expected. (There are some stories of games like this where if you remove the limit on the FPS everything in the game suddenly moves much, much faster). Additionally, this can be bad as a slow computer will run at a framerate less than expected, and the physics will slow down accordingly. Its done, but doesn't seem to be good game design. & #x200B; The other common way that I know of is to just have 2 threads: one for graphics updates and one for physics updates. In this case, whether or not your 10000FPS actually shows you 100000 different unique frames per second is dependant on how often the developer chose to update things. Its possible that the physics only get updates 60 times a second, but your camera movements and character position (i.e. things that are based on user input and not on time) might be capable of updating much faster. (Pure speculation, but I bet most games \\*don't\\* do that, and instead update character/camera position at the same time a slice of physics is calculated. I may be wrong though)",
"It depends completely on developer how quickly and often the world data updates. Often it is quicker than graphics frame rate but sometimes developer lock the two together."
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9ywes2 | How did Nasa contact with Astronauts during the first Apollo mission without satellites? How did the frequencies work with that range? | I've looked online but couldn't figure out how these frequencies worked for them to radio each other. | Technology | explainlikeimfive | {
"a_id": [
"ea4ks2c"
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"text": [
"Really strong radios. You can keep adding power to make it reach farther and you can make really big antennas to hear a weaker signal. Because the earth spins, there are a bunch of places all over the world with the big radios and they take turns talking to the astronauts so that when one radio can’t see them a different one can. Also, the moon always faces one side to earth and the astronauts only landed on that side. When their spaceship went around the moon before they landed they couldn’t talk to earth for half the time: when they could not see it. Note: this is explain like I’m five so I explained like I would to a 5 year old. If you wanted something more in depth then try r/NASA or r/Space"
],
"score": [
15
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9ywmng | How can Google search through practically all of the information in the world in only milliseconds? | Technology | explainlikeimfive | {
"a_id": [
"ea4mo0n"
],
"text": [
"This is where indexing comes in. Whenever they scan a web site they will filter out the key words. Then they have a huge database where they will file the website under each of those key words. When you search for a word they can just go to that database and just instantly look up the websites that used that word. This list of websites can already be sorted on which ones are more relevant. You also have indexes that use two key words, or three. They might also have to compare two lists of websites if you have searched for something which is not directly in their index which might take some time."
],
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9ywulu | why do phones charge faster from a lower percentage compared to nearly full? | It seems to take a much shorter amount of time to charge between 30% to 40% for instance, compared to 90% to 100% | Technology | explainlikeimfive | {
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"text": [
"The stadium effect is in effect here. Imagine an empty baseball stadium that holds 60,000 people and outside are 60,000 fans waiting to get in. Those people are the electrons looking for a seat in the battery. The first people can sit anywhere they want as fast as they want. As more people enter it becomes harder to find a seat. Thus, they have to walk around for a bit until they can grab an empty seat.",
"When a battery has a long way to go, you are doing a kind of bulk charge where you're dumping a lot of energy at a higher current in so the battery appears to fill up faster until it gets to about 80% or so. The it enters a phase where the voltage is held steady while the current is decreased to get it higher to the voltage you want it to be at. When it gets close to the top it slows down with a decreased voltage to get to 100% without going over or causing damage. So you're seeing the bulk charging stage go faster, but the last 5% goes a lot slower. It would be similar to trying to fill your gas tank full and when it gets to the top you're squirting in little bits at a time so as to not overflow and spill all over yourself.",
"Phones uses lithium ion or lithium polymer batteries, both of which are dangerous when overcharged. Your phone purposefully decreases the charge rate so it doesn't accidently overcharge the battery. It has nothing to do with being physically harder to charge the battery. If you want an analogy it's like trying to fill a glass of water to the brim, but if water spills out it could explode. You start out by turning the faucet on all the way and as it gets closer to the top you decrease the amount of water coming out of the faucet. If you want to get really technical initial charge is done at constant current (C/10 is usually a good rule of thumb). When the battery hits a certain voltage the charge controller switches to constant voltage charge. So as the voltage increases the current decreases and the time it takes to reach 100% increases exponentially.",
"Because the fuller the battery is the harder it is to charge more, like a spring, it is harder to push an already compressed spring. And so phones charge their batteries in straps and severely lower the current after about 80%, entering “trickle charge”",
"Compare it with blowing up a balloon: In the beginning its easy because you are only inserting air and barely stretching the rubber. Later you need to a. add air into a high pressure environment and b. stretch the rubber beyond where it goes easily. While the battery doesn't expand, the internal \"pressure\" being charged against is there.",
"First of all, this limitation does not apply to all battery types. Lead acid and nickel cadmium can be charged at full current up to 100% as long as they are not overcharged. Lithium cells can't be exposed to more than around 4.2 volts without being damaged. When the cell is discharged, it can take a higher charging current without going over-voltage. At some point in the middle of the charge cycle, the 4.2 volt limit is reached, and the current drops as the cell's open circuit voltage approaches the applied voltage."
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9z1700 | How do pedometers accurately count your steps? | Technology | explainlikeimfive | {
"a_id": [
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],
"text": [
"My pedometer has a GPS in it that alerts the police when I go within 200 meters of a elementary school.",
"Simple answer is that it uses accelerometers and gyroscope sensors to count a step, a sufficient enough abrupt change in those sensors as you move your body count as a step. Although that's why they aren't that accurate. If you wave your arm abruptly it can count as a step even if you're standing still.",
"Took a cheap one appart years ago, was a ball in a small tube with a button on each side. Walking rocked it back and forth counting with each press"
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9z1byp | How do noise-cancelling headphones "cancel noise"? | Technology | explainlikeimfive | {
"a_id": [
"ea5lorb"
],
"text": [
"Think of sound as it's often represented as a wave - up/down/up/down/etc The headphones listen for that and play the opposite: down/up/down/up - just the right amount that the ups and downs exactly cancel themselves out"
],
"score": [
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9z7jn0 | Graphic card drivers or drivers in general? | What are bad drivers? What makes them bad? | Technology | explainlikeimfive | {
"a_id": [
"ea6xuef"
],
"text": [
"Drivers are the programs your computer uses to talk to hardware. The computer wants to draw a blue circle, but doesn't necessarily know how to tell your fancy card from Nvidia. It tells the driver \"draw a circle\", and the driver tells the card. But wait! You replace your fancy graphics card from Nvidia with a card from AMD. The AMD card doesn't speak the same language as the NVidia card, so you will need to install a new driver. Good drivers do that translation very fast, and don't make the computer crash. Bad drivers do the job slowly, or cause the computer to crash. There are also degrees of good and bad: a specific version of the drivers might be faster and more stable than another."
],
"score": [
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],
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9z7tq0 | What is meant by 16 Bit Resolution in terms of audio? | Technology | explainlikeimfive | {
"a_id": [
"ea70ez3"
],
"text": [
"When audio is digitized the analog to digital converter is taking regular samples of the electrical signal at a certain resolution. For example it can take 44.1kHz samples at 16 bits. So every 1/44,100th of a second it measures the signal to one of 65,536 different values. This is quite common values for music as it covers the range of audio all but exceptional people have. The sample rate determines the highest frequencies you can represent. In this case it is 22kHz. The resolution on the other hand determines the dynamic range and the signal to noise ratio. So the higher the resolution the more low volume sounds you can record and play back."
],
"score": [
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9zaepj | Why is there an automatic margin on the body of an HTML document? | Why do I have to specify margin: 0; | Technology | explainlikeimfive | {
"a_id": [
"ea7okgt",
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],
"text": [
"It's legacy. It stems back to the very early days of HTML, when CSS was not a thing yet. Back then people used to simply put plain text directly into the body (most pages back then were just purely text + links). In order to make the text not stick to the window borders, a default margin was added. Since the same sort of default margin was present in a typical word processor, this felt very natural to people.",
"The people who designed the browsers decided that pages look best when they have some minimal basic CSS fields configured, even if the pages themselves don't have a style-sheet attached to it. Some margin on the left/top/right/bottom, a certain font and text size, background colour not black etc. URL_1 URL_0"
],
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"https://www.w3.org/TR/html5/rendering.html",
"https://davidwalsh.name/firefox-internal-rendering-css"
]
]
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9zb0z3 | how are traffic lights programmed, especially during rush hour? | I constantly see the traffic lights on **main** roads have **equal or shorter duration** than the road it crosses which has 10x less traffic.For example green light on main road might last 20 sec while the road it crosses has 30 sec. What's the logic behind this? This causes huge traffic jams on the main road while the other road barely has any traffic. | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Someone didn't do their job right, that's why it's not working well. Or...maybe the controller has switched over to a failsafe program to handle that one or more of the detectors are broken. It can be the failsafe program that is poorly written too. Theoretically, it can also be a broken button for pedestrian crossing that constantly demands a time slot, and thus breaks the program. Or, I guess, a clock that thinks it's midnight when it's rush hour, so that what you see is actually the night program where the program makes a lot more sense. Either way, that is not how it's supposed to be.",
"There are a number of ways an intersection can be programmed, some are just on timers based on the avg traffic flow each way. Some also have weight sensors periodically down the road to see how many cars are waiting and will trigger after a certain distance has been reached (if the timer has not already gone through). Some have priority sensors, usually of there is a minor road crossing a major road, and the light will be green for the major road unless there is a car waiting on the minor road, then the lights switch to a timer base until there are no more cars on the monir road. And all traffic lights can be manually changed from the main light board. These could very well be different than the ones where you live, but I would believe them to be similar at the very least. To answer your scenario, I would assume its a problem with the timer, especially in rapidly developing areas traffic numbers can be much larger than what the system is programed for."
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9zce0f | Why the airplane's black box is orange and what does the black refers to? | Technology | explainlikeimfive | {
"a_id": [
"ea80j71",
"ea8314a"
],
"text": [
"Orange because it’s bright and easy to find after crush. Black box means you have no idea what’s inside until after you open it.",
"Firstly, you'll never hear an aviation porfessional call them \"black boxes\" they're flight recorders, the term is used by the media and the public. Originally black boxes where painted black on the inside because they used photographic film as a recording medium and we're very light sensitive. Some of the first versions used by the UK's RAF in the 1940s such as Oboe, GEE and H2S, were added to bombers on a regular basis, were roughly covered in hand-made metal boxes and painted black to prevent reflections. Modern boxes are a painted bright orange like almost all other safety equipment for one reason... it's really easy to spot in a big pile of wreckage. It's the first bit of equipment that Air crash investigators will look for with trying to figure out what happened becuase they contain (usually) all the information they need."
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9zcnko | How do hackers know "where" to find their targets? For instance, if they want to steal some records that Chinese government keeps, how do they find out where to "go"? | Technology | explainlikeimfive | {
"a_id": [
"ea83zja"
],
"text": [
"They create programs that sniff out security flaws they intend to exploit. Either that or they have a particular target in mind and work to crack that particular security, often with no luck, but occasionally with success. For ever 1000 fails, someone succeeds. You hear about those who succeed, not those who fail, so your impression of how successful these hackers are is skewed."
],
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9ze72n | Is booting off live Linux distros considered a high breach of security? | It is relatively easy to access all files on most public windows PCs using a live ubuntu / archlinux distro on flash drives , even those with user protected passwords. Do most organisations put a high priority in restricting access to bios to disable booting from usb? , especially those without measures like bitlock encryption? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"If I have physical access to a computer, nothing you can do to the BIOS will slow me down by more than the minutes it takes me to remove your hard drive and plug it into a computer which I control. If you want data security, use disk encryption or just don't store anything on the local machine.",
"Yes, it is. And no, most organizations do not implement that security. The first principle of digital security is physical access. If an attacker has physical access, you’ve already lost. Instead of blocking USB booting, most organizations have locked doors, and consider that good enough. For external attacks, the least common form of breach, they would generally be right. For internal attacks, they’re screwed. On most corporate networks and environments, you can simply walk up to a machine, boot to a live USB, copy the whole disk to another USB, and walk away, and no one will really notice. So yes. You are completely correct. It is a huge security risk that no one takes seriously and everyone who doesn’t take it seriously is wrong. “The biggest misconception about security is that it exists at all.”",
"Yes they do indeed. Depends a lot on the environment. In banks for example there will be additional software or even hardware to prevent booting from usb devices."
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9zf33p | How can an original gameboy that has been sitting in storage for 6 years still have a full battery charge, while my old cell phone's battery is dead after a couple months? | Technology | explainlikeimfive | {
"a_id": [
"ea8n6w6",
"ea8ufuh"
],
"text": [
"Phones use lithium batteries. Lithium batteries are terrible. AA batteries last 30+ years without being touched",
"Rechargeable Li-Ion batteries generally have a relatively high self-discharge rate. The battery protection circuit and the phone’s clock also consume some power. With the gameboy there are good chances that it’s completely off when turned off and there are non-rechargeable batteries with very low self-discharge."
],
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9zgq8g | On URL_0 , why does it seem like a human player with an ELO rating of 1200 is much better than a computer with an ELO rating of 1200? | Like do they use different criterias to evaluate the performances of human players vs AI players? I can easily beat a CPU with a rating of 1200 to 1400 but I can barely beat a human player with a rating of 1100. | Technology | explainlikeimfive | {
"a_id": [
"ea96u0q"
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"text": [
"I've not used URL_0 anytime recently, so not totally sure what you're referring to, but 3 ideas come to mind Are you able to see the number of games played? The bots might just be playing a larger number of games, with many of those being much weaker opponents, where the human is spending their more limited time on better matched opponents Computers are going to be good at playing against some play styles and weak against other play styles, perhaps you're playing less systematicly or are more creative about how you play. I'd be curious if everyone would feel similar to you about those ratings Are these bots or a computer trying to simulate that rating? If trying to simulate it (if not bots), again might just be weakened to your play style in the attempt to simulate it. The rating ends up increasing in value over time I believe, so maybe the simulation was programmed for a ELO of 1200 say 10 years ago, and hasn't been updated to the modern level of the game. Even then it's artificially \"weakened\" for that, which I can't imagine would be an exact science ever."
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9zhg37 | Why do phone charging cables start becoming loose after a while when plugged in? | Technology | explainlikeimfive | {
"a_id": [
"ea98y23"
],
"text": [
"If you're talking about the common micro-USB cables, it's the two tiny springy wire things on the plug. They help keep the plug snug, but they can get flattened down over time. You can bend them back up a bit with a pin or staple to make them feel a bit more snug."
],
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9zjrh1 | Why do video games need the original source code file to be further worked on or remastered? Why can’t this be extracted from a copy of the game? | I just look at stories about how the Silent Hill and Kingdom Hearts remasters fan into issues because they didn’t have the source code and wonder; why wouldn’t a copy of the game suffice? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"Okay. So let's say that you want to bake a cookie just like the ones that grandma makes. You could try to eat her cookie, and then using your knowledge of baking sort of reverse engineer it, but it would be an incredible hassle and very hard to do. But if you had the recipe she used, it would be very easy to figure out how to make it and then make your own. A finished game is like a cookie. The source code is complied and turned into the finished product, sort of how the recipe is baked into a cookie. Because of how the source code is transformed into a working game, it is very difficult (not impossible, but difficult) to reverse the process and figure out the code.",
"When writing code, good programmers will include documentation in the code. Sometimes that's comments, sometimes it's \"just\" descriptive names for variables, constants, and functions. For instance, you might find something like this in the source code: left = MARGIN_SIZE; right = WINDOW_WIDTH - MARGIN_SIZE; ## This sets the edges to account for the margins Draw_Header(left, right); Even if you don't completely understand it, you can get a good feel for what it's supposed to be doing. When the code is compiled, all that helpful information is lost, because the computer doesn't need it; it's there for humans. If you compile the code above and then \"decompile\" it back to something supposedly human-readable, you'll get something along the lines of: var01 = const01; var02 = const02 - const01; func01(var01, var02); Perfectly valid code, but there's no indication of what the variables and constants are supposed to represent, or what the function might be doing. When you've got tens of thousands of lines that all look like that, it's pretty much only theoretically human-readable."
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9zl0t5 | why is i5 better as a gaming CPU than i7 ? | It's not like I would choose a VW Beetle instead of a Porsche 911 for racing. Is there a simple explanation why a gaming rig often has an i5 ? When I built my pc I just picked the (then) powerful i7 thinking it is all-mighty. | Technology | explainlikeimfive | {
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"It’s not that it’s better, it’s just that if you’re using the PC primarily for gaming, there’s no need for a high-end, expensive CPU, when the money you save could be put towards a more powerful GPU. Now, games are becoming more CPU intensive but if your PC is for gaming then worry about the GPU first. i7’s are good for workstations and video editing/rendering.",
"More cost effective for the same performance. The i7 has hyperthreading over the i5, the additional virtual cores can absolutely help in productivity related tasks such as creating videos and 3d animation. However, games typically aren't optimized to take advantage of these extra cores and therefore no performance is gained. I7 isn't a bad choice for gaming, but if it's all you're doing on that oc it's not the more cost effective choice is all.",
"Having a CPU better than an i5 tends to be a money-sink in a gaming PC: Most of your system's processing will likely be through your GPU (assuming you're running fairly graphically intensive games), and as long as you have a graphics card and not an Integrated (on your motherboard) Graphics Chip your CPU shouldn't be pulling up the slack unless you're also recording/streaming on the side. EDIT: There are reasons to get an i7 instead, but having a new and cutting edge CPU is more expensive. TL;DR: a high-clock many-core CPU is less of a gaming thing and more a utility thing, if you're recording, converting, compressing etc. on a regular basis Bonus: Non-cutting-edge hardware will have drivers updated less and be less liable to cause instability"
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9zlyaw | How did separate civilizations develop the same tools & weapons? | Technology | explainlikeimfive | {
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"It's a natural evolution of weapons as a theory. People figure out that using a stick hits hard. Using a sharp thing cuts. Using something heavy bashes. Then they combine the ideas. Stick with weight = hard bash. Sharp stick = more cuts. Sharp thing at end of stick = stabby thing. Thrown stabby thing is safer. Eventually they adapt everyday tools to these things and discover that tension on a branch can launch stabby things further.",
"The Sentinelese people who killed that guy didn't come up with bow and arrow on their own. There was a lot of trade and communication and migration back in the day. This particular tribe is a Negrito group--consisting of people who left Africa in a very early migration, and a different one than the one that resulted in the peopleing of Asia. So while they're Asia/Pacific Islanders, they look distinctly different and are from a different population. They're isolated NOW, but this was not always the case. & #x200B; The bow and arrow is enormously complicated--you have to create not just a bow but also lots of very accurate arrows, and a lot of skill is involved, too. It looks like the bow and arrow was invented in Africa about 64,000 years ago, and the Negritos who now live on Sentinel Island brought the bow and arrow with them when they began their migrations out of Africa that ultimately resulted in them ending up in that remote Pacific island.",
"Convergent evolution of technology can be explained by the fact that humans are equally clever everywhere and if you give them enough time in the right environment, they will eventually stumble upon the same useful mechanical principles that other folks did. They make tools based on these principles, which are passed down and refined / innovated upon until they end up with roughly the same technology as people they’ve never interacted with."
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9zmbty | What is Docker and Docker-Compose | Technology | explainlikeimfive | {
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"Imagine you throw a party. To party like ELI5 you need soft drinks, popcorn and music. You could buy *Magical Party Maker 2000* (MPM2k) which does all this stuff and more. Or you could buy soda machine, popcorn popper and bluetooth speaker. Problem with MPM2k is that * It's kinda complicated and it does some unnecessary things. * If for the next day you go to the beach and just need the music, you still have to carry this heavy thing with all these unnecessary features with you. * If you just want to practice your party dance beforehand, you need to fire up the huge machine instead of just small speaker. * If your guests eat more popcorn than drink soft drinks, with MPM2k you'd still would need to buy another huge machine instead of just extra popcorn popper. * If soda machine breaks guests might not even notice it, but if the MPM2k breaks, there is no party anymore. Unacceptable. The party must go on. So it's better to have these small lightweight machines that are specialized in doing one job really well. You can change them, add more and fix them more easily than to do all this with one huge machine. Docker containers are just like the popcorn machine. Docker is a platform for your party. Docker Compose is this super awesome girl who can use all of the party equipment together to host a party of a century or tool for defining and running these containers. E: Oh, one more:You make awesome mixtape and copy that to CD and send it to your friend for their party. Next week you get a note that your friend didn't get the CD to work as their CD player is just tiny bit different than yours. Imagine if instead of sending just the CD you could copy your *CD player* and send it to your friend. Docker enables you to run exactly same stuff on your development computer and production server. No more \"this works on local machine but not our production server\" type of problems!"
],
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10
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|
9zmqoe | the difference between one-way SSL authentication and two-way SSL authentication | Technology | explainlikeimfive | {
"a_id": [
"eaafbol"
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"text": [
"One way: the server has a certificate signed by a certificate authority, and a private key which it uses to sign this certificate. The client has the root certificate authority's certificate as well, which it can use to validate the server's certificate. Two way: same as one way, except that the client also has a certificate with a private key, which it uses to sign it's certificate and send to the server. This allows the server to validate the identity of the client."
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|
9znvml | How do companies like AMD, Intel, NVidia etc make better cores? | Technology | explainlikeimfive | {
"a_id": [
"eaaolny"
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"text": [
"Further research into computer technology sees the transitor (a key part of a processor) getting smaller and smaller, from 22 nanometers, 20, 16, 18, 14... As long as we are still able to shrink the transistor (until it gets too small for the basic principles of to work), companies will continue to find ways of jamming as many of them into a processor, and more is usually better."
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9zoiyh | How was it possible to build those highly accurate CNC machines we have today? | As the questions in the title says, how could we build those higly accurate CNC machines (or any other manufacturing machine) to that accuracy, assuming you need accurate machines to machine the accurate parts for the accurate machine? Was it some kind of „make 10 parts, take the best one“ and repeating this and gaining the accuracy through that? And to take the best part, you need good measuring tools and they needed manufacturing by accurate machines and so on. Its like „what was first, the egg or the hen?“ | Technology | explainlikeimfive | {
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"One of the most important parts of how very high precision machine tools are made is the fact that clever design allows relatively inprecise parts to be assembled into a machine that can make a more accurate part. A pretty good example of this is the micrometer, which uses a screw to measure parts with a significant level of precision. Screws are easy to make on even a relatively crude lathe, and micrometers can be used to check the accuracy of parts that will be made into a more precise machine. Another important part of making good machine tools is being able to make perfectly flat surfaces that can be used as beds, machine ways and reference planes. In theory it's possible to rub or scrape any three non-flat surfaces together in a specific order and eventually they will reach whatever level of flatness that is needed for their intended application, without any fancy tools or precision equipment required.",
"> Was it some kind of „make 10 parts, take the best one“ and repeating this and gaining the accuracy through that? For something like computer chips, it's kind of like that. Take your USB mem stick. The same company will sell a 64gb, 32 gb and 16gb stick. All of these sticks are the same size. Now there actually isn't necessarily a production line for each of those three. Instead they have one line where they try to make say 100 64gb sticks. They then test each one and since the process isn't full proof, they get 20 sticks at with enough transistors for 64gbs (20% Yield) they also get 30 sticks with at least 32gb usable (which might actually be 36gb usable but they tend to keep to powers of 2 because people are used to that and deactivate the rest) and 45 sticks at 16gbs and the rest might be too little memory to matter (no one buys an 8gb stick these days). How does that apply to CNC machines? Well this kind of batch manufacturing of electronics allows for it to be profitable to take a risk on making SUPER high precision measuring devices (the more transistors you put on a chip, the better your precision). The better measurement devices your have the better tolerances you can maintain etc."
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18,
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9zpdmc | How does the algorithm of the DVD corner logo work. | [ URL_0 ]( URL_0 ) & #x200B; | Technology | explainlikeimfive | {
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"eaazdbw"
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"text": [
"The object moves according to a vector. Upon hitting a boundary the direction of the vector is adjusted while magnitude stays constant. Eli5 version: Throw a ball against a wall like handball. Programmers recreated that motion in software with the added property that the ball bounces forever."
],
"score": [
16
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