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8ii4gv | Is there any reason broken pieces of technology start working again after you stop using them for a while? | Technology | explainlikeimfive | {
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"Bad solder joints. They don't connect completely. As humidity/temperature/etc change, the solder expands or contracts and the connection returns. A good whack can often have the same effect.",
"If the reason a device stopped working was due to a thermal shutdown (it got too hot so it shut itself off to prevent damage) then yes, it cooled down. But otherwise I have no idea what you might be referring to."
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8ijfc0 | what causes rewinding a VHS to create visual distortions on the screen instead of playing normally in reverse? | Technology | explainlikeimfive | {
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"I'm going to assume you're talking about \"scanning\" backwards during playback, since \"rewinding\" means stopping playback to rewind the tape to the beginning. It actually has to do with how the signal is recorded onto the magnetic tape. It's referred to as helical scan method (both recording and playback). So you might imagine the signal is recorded this way on a tape: |||||||||||| but it's actually recorded this way //////////// there's a variety of reason for doing it this way, but how it pertains to your question is that the scan head also reads in a helical pattern, so when you're scanning forward or backwards it gets misaligned and results in the scan interference you're talking about. [Here's the Wikipedia page for VHS which explains perhaps more than you want to know about VHS.]( URL_2 ) [Here's the page for Helical scan.]( URL_0 ) [And finally here's a question on the Video Production StackExchange that's the same as yours.]( URL_1 )"
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"https://en.wikipedia.org/wiki/Helical_scan",
"https://video.stackexchange.com/questions/20190/what-causes-the-vhs-rewind-effect-and-how-did-rewind-preview-work",
"https://en.wikipedia.org/wiki/VHS"
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8ijl0x | Why do HD pictures and videos sometimes look more HD than in real life? | Technology | explainlikeimfive | {
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"text": [
"I'm assuming you may be referring to this post: URL_0 In this case the answer is 8K HDR in a scene that's well lit.",
"HDR (high-dynamic range) and being more than 30FPS (which gives it is smoother appearance).",
"I think there's also a psychological aspect to it - we're so used to seeing the granularity that comes from low resolution images that when we see one at super high resolution we mentally reject it. Similar to the uncanny valley, I'd wager."
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8imhbb | Why can't you use a headphone splitter to send 2 sources to one pair of headphones? | Technology | explainlikeimfive | {
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"text": [
"When you run one source to two sets of headphones, they're both passive devices that simply absorb the power. If you electrically connect two sources together, you introduce the very real possibility of the more powerful source simply shutting down the weaker source's amplifier. You've got a \"backflow\" of electrical power. If you want to connect multiple sources to a single set of 'phones, you need to, at minimum, have electronics in there to prevent backwards electrical flows. Ideally, you'd get some sort of mixer, giving you the ability to set levels of each source. I'd check /r/headphones for specific recommendations."
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8imi6s | What happens to a battery when it reaches 100% charge and stays charging? | Technology | explainlikeimfive | {
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"Dumb old batteries like lead acid and nickel cadmium can handle trickle charging indefinitely; excess charge will just turn into heat. Trickle charging generally means a rate that will take at least ten hours to fully recharge the battery. Anything charging faster than that has to have an automated system to work out when to stop. Or else overheating and battery destruction with the potential for fire or even explosions. Modern lithium based batteries are more finicky and over charging them, even at slow rates can cause fires. Battery packs and/or the devices they go in contain intelligence to monitor the charging and have it stop at the appropriate time based on things like voltage, time spent charging, rates of charge and temperature. Devices were long battery life is required, e.g., electric cars, might not ever fully charge or fully discharge the batteries.",
"I noticed my screen started to bulge, I couldn't remember dropping it. Took it to get fixed and phone guy told me my battery had basically exploded due to being left on charge too long all the time. Seemed plausible to me. But the same guy also replaced my smashed screen about 8 weeks beforehand... maybe he he did a dodgy job??",
"In every case I'm aware of, either the charger or the battery can detect that the battery is at max capacity, and then sends an \"OK, stop charging!\" signal. It works from the battery for a little bit -- maybe as little as 30 seconds -- and then says \"OK, charge again!\", resumes charging, and shortly gets the \"OK, stop charging!\" signal yet again, and this just continues forever.",
"The charging circuitry will monitor the charge of the battery and shut off the charger when it's fully charged."
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8inhi1 | Why are almost all LCD displays (calculators, kitchen appliances, digital watches) at a slight angle? | Technology | explainlikeimfive | {
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"The LC (liquid crystals) re-orient themselves to block the passage of light or allow it. Like a piece of paper that will block your view if it's facing you, and not block your view if it's egdewise. So if the LCD display is back-lit, like a computer screen that has LED lamps right behind the screen, then the screen doesn't have to be angled. But if the display is not back-lit, if the surface behind the LCD is just a grey-ish reflective piece of metal, then the light from the sun or overhead lightbulbs must be allowed to get in past the crystals, strike the surface, then reflect back at you THROUGH the crystals, so you need a slight angle for that. It's like trying to catch the sun in a small mirror, you have to angle it a little (or a lot)."
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8invsp | How do wireless chargers work? | Technology | explainlikeimfive | {
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"text": [
"By induction. Basically there's a coil of wire in the charger that creates an alternating magnetic field, and there's another coil of wire in your phone that creates electricity when it's inside an alternating magnetic field."
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8iogz2 | Why does water on my phones touchscreen render the screen seemingly useless until it dries/is wiped off? | Technology | explainlikeimfive | {
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"Modern touch screens work by measuring changes in the electric capacitance of the screen. They detect when a conductive object touches the screen. Water is conductive, this means that moisture (and droplets) will register as touches. Depending on the condition this can mean that your phone will think you have a few extra fingers or that you are touching the whole screen, which makes it unusable (Most screens can only handle a few touches at a time)."
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8ipzc4 | What is bruteforcing? | Technology | explainlikeimfive | {
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"text": [
"Trying every single possible combination until you get it right. It's why websites are now forcing you to use special characters, numbers, AND caps in passwords. It makes that many more possible combinations so bruteforcing is harder.",
"Instead of doing something intelligently, you just apply raw power. Instead of using a pulley system, you get a bunch of guys to lift the stuff. Instead of trying to figure out a person's password based on what you can find out about them or using a security flaw, you have a computer just try every combination. Instead of figuring out the solution to an equation by solving the equation, you just start plugging in values and try to narrow it down more and more.",
"Imagine that you have a door lock you have lost the key to. But the locksmith has a key ring with every possible key to that exact lock. Every single one of about a million keys. All you have to do is to try each one, right? That’s bruteforcing. Brutal. Time consuming. But it will get a result. Eventually. It’s the same with passwords and encryption keys. Trying every combination, one at a time. Bruteforcing. Only limited by the total number of combinations, and the time required to try each combination"
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8isujs | What's the point of the Icognito tab on Chrome when they collect all of our data anyway? | Technology | explainlikeimfive | {
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"I believe it’s more for keeping other people who may use your computer from seeing what you’ve searched for. Nothing is saved locally.",
"The only time I use incognito is when I want to view a newspaper website that only allows a certain number of views per month."
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8iu83j | How do lofi hip hop channels on youtube stream 24/7? | Technology | explainlikeimfive | {
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"text": [
"They have a large list of songs in a playlist and they are usually played in random order. Being one of their frequent listeners (rip studying girl from Wolf Children), I’ll can confirm that the songs will be repeated eventually. You can also check the description for the link to the song list on Spotify."
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8ivc6z | How do Movies and TV Shows get transported to the Cinemas and TV Stations? | Like Blu Rays? Hard Disk? Internet? Today i found a Blu Ray 4k Release which is over 80 Gbs. How to handle a complete Season? | Technology | explainlikeimfive | {
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"text": [
"Nowadays, hard disks are delivered to cinemas and every time they wish to play the movie, they send a request to the main server. The server sends in an decryption key which enables the cinema to play the movie, on the projector."
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8ivxp6 | why are keyboards arranged in a slanted grid instead of a standard grid? | why are they arranged [like this]( URL_0 ) instead of a standard grid that crosses perpendicularly? | Technology | explainlikeimfive | {
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"It is a holdover form mechanical typewriters. If you look at the keys you might notice, that the center of each key is fixed so that no two keys have their center in the same horizontal position. This is important because mechanical typewriters used to have levers that reached up from the keys forward to then angle towards a position in the center where the actual typing took place. Obviously the two levers couldn't overlap and anchoring the levers anywhere but the center of the keys would have resulted in them breaking sooner. [This is the best image I could find with a quick google search, but it should be sufficient to illustrate what I am trying to describe.]( URL_0 )",
"It helps typists have more of a range for each finger. Contrary to popular belief, very few if any features were made directly to the keyboard to slow typists down.",
"It started in order to make the design of a typewriter keyboard easier to engineer and manufacture, and there's something to be said of for aligning the keys with the motion of human fingers, but it's mostly tradition. Among keyboard enthusiasts there's a growing community around \"ortholinear\" keyboards. I know a few people who own one, and they say that it only takes 10 minutes to get used to it and from there it's quite nice both for typing and aesthetically. They generally look like [this]( URL_0 ) (ignore the funny key labeling. Custom keyboards are a lot of fun if you're into it, but I understand if you think blank keys or novelty labels are dumb).",
"So that no two keys were directly in line with one another. The original typewriters would swing an arm up to an inked ribbon to imprint a letter on the page. Those arms were directly linked to the keys. If two keys were directly above or below each other, they wouldn’t have separate arms. It’s also for the layout of the letters themselves. The pattern of letters is so that you would rarely need to use the same finger, or even the same hand, to hit consecutive letters. This allowed for less possibility of key arms colliding, and sped up the typist."
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8ixg6o | I know that 'error 505' is a connection issue when loading a webpage, but why 505? Are there other ones out there that I haven't seen? | Technology | explainlikeimfive | {
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"text": [
"Those are HTTP status codes: URL_0 HTTP and HTTPS are the communication protocols between your web browser and most websites. Those numbers indicate the basic result of each request. The codes are grouped into hundreds: * 1xx codes are informational and usually prompt further communication * 2xx codes indicate success * 3xx codes indicate redirects * 4xx codes indicate client error * 5xx codes indicate server error Other common codes you might recognize include 404 errors when you request a page that doesn't exist.",
"Http response codes are categorized into different groups, based on the first digit in the code: 1xx: Informational responses 2xx: Success 3xx: Redirection 4xx: Client errors 5xx: Server errors These response codes are given to your web client by the server, and are part of the HTTP protocol. One of the most common ones which you've probably seen is an http error 404, which means the requested resource wasn't found (missing web pages, broken links, bad image urls, etc.) Other common status codes are error 400 (bad request), error 401 (not authorized), and error 500 (internal server error). Also, error 505 doesn't necessarily mean it's a connection issue, but rather the server or client are trying to use an unsupported http version. More information about status codes: URL_1 More information about the HTTP protocol: URL_0 Edit: formatting"
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8j1emv | Is there a reason why most horizontal screen resolutions are multiples of 360? | Technology | explainlikeimfive | {
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"To be honest, for super duper long time, the standard was 1024x768. Now to answer you.... Technically, When the screens are made in industry, to make the physical set up easier, the panels are split into equal parts, so the smallest number divided up into horizontal and vertical are numbers like 16, 32, 64, 128, 120, 256, 360 n so on. So, Square boxed tv are no longer favored and all want long triangular shape tv's. Thus comes another factor into play... Thats aspect ratio. 4:3 16:9 16:10 11:9 Now, remember the panel splits (for making construction easy): 16, 32, 64, 144, 256, 360....so on. 16:9x 16= 256x144 youtube one lowest. 4:3 x 32= 128x 196. 4:3 x 64 = 256x 392. 16:9x120 = 1920 x 1080. So on..."
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8j2bhl | How do image captcha questions know whether you selected all the right photos? | It says "select all the vehicles" and I clicked one out of a few images. the program knows I didn't choose it all as it insists "please select all matching images". But sometimes I didn't click every single image and it lets it slide. Are the captcha quizzes predetermined if it knows the right answers? | Technology | explainlikeimfive | {
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"In the original CAPTCHA questions, the program asking you what the text said knew because it created the image. They'd start with known text and distort it. Later iterations, like early Re-CAPTCHA, worked because they knew one of the two images and just used the 2nd image to collect information. Modern ones (like \"click on road signs\") are a bit of a secret. It's safe to assume that they're using images they **mostly** sure about, based on image-recognition AIs, and they're doing all sorts of statistics on the back end hoping humans will double-check the bits they're less certain of. Again, it's possible to combine this with some known-good and known-bad images. You need to remember that they can show any of these images to *thousands* of people. If it turns out you were lying on one, they can give you harder questions in the future. A captcha doesn't need to be 100% - it just needs to slow down spammers/etc enough to make the job less profitable."
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8j455c | Why can’t there be one universal computer language for everything by utilising frameworks or modules to cater to specific purposes | Technology | explainlikeimfive | {
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"text": [
"The same reason we don't have just one universal car. Different languages serve different purposes, just like we have trucks, busses and family cars. Some languages are better for writing large systems, others are for websites and others are better for small scripts. Also, languages develop and evolve over time, so some people stick to old languages while others prefer newer ones. Sometimes we have similar competing languages, like Java and C#. They are developed by competing companies - Just like we have competing car companies."
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8j46w7 | How do ultrasounds work - more specifically on pregnant women | Just went for an ultrasound with my wife, I was amazed at its technology. I tried asking the nurse how it really works - she couldn’t really give me an answer. “Hey bud, I just know how to use it” attitude. Haha | Technology | explainlikeimfive | {
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"The wand has little transducers, like speakers, that make a sound too high for your ears to see. When you make a sound, it bounces back off things that it hits. This works, even under water, when the sound hits something that's denser than water. The wand makes a pulse of sound and listens for the echo. The machine filters out \"too-close\" echos, called reverberation, from the goop or woman's skin and uterine wall. That's one of the knobs the operator adjusts. The gap between the uterine wall and the baby gives the sound enough travel time that the next echo can be detected clearly. By sliding the wand around in the goop and changing the angle, the operator can look around at what's inside. The screen shows a 2D projection of the conic projection of the distance measurements."
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8j5xh5 | Where do files go when you empty recycling bin? | Technology | explainlikeimfive | {
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"text": [
"Nowhere. The sector that the file was at is just marked by the system as available to write. All that is deleted is the index that says a particular sector is occupied.",
"Technically, nothing happens to the file, it is still on your hard drive. However, the computer keeps a master file saying where to find each file saved on the computer on the hard drive. When you delete a file this reference is what is actually removed. It's kinda like a big phonebook. If an entry is removed from a phonebook, the house is still there, but nobody knows where to look. This is how forensic scientists can recover deleted data off computers for an investigation. The file may still be there on the disk, as long as they know where to look. The only way to actually delete a file is to have some other file written in its place (since the location is now \"free space\" and it thinks nothing is stored there). This is a process controlled by the operating system, but there are some programs that \"shred files\" or \"bleach free space\". Basically these force the computer to actually overwrite the old file with meaningless data."
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8j6h83 | How does ring re-sizing work? How is it possible to do it without breaking or warping the metal? | Technology | explainlikeimfive | {
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"Goldsmith here, not from de US so ill try my best to explain it but im not really used to explaining this in english. There are different ways to resize a ring. If its a weddingband without stones or ornaments etc you can just stretch it on a machine. When you stretch it the band does get thinner but you normally dont really see any difference. You can also shrink the ring by pressing the ring in a V-shape so it gets smaller. If you try to stretch a ring with a stone it will break cause it is weaker in the place with the stone. So if you cant stretch or shrink it with a machine you saw the band open and put another piece of gold/silver in between the band and solder it together. Or you cut a little piece out is it needs to be smaller. Then you smoothe it all out by removing the excess material and solder and you polish it. Also, sometimes if its a thick band and it needs to be just a little big bigger we just hammer a bit on the band, the material gets a bit flatter but the ring gets bigger",
"Finally, something I can answer! There's three factors when sizing: the type of metal, how much you're sizing, and which way. Gold and silver are fairly easy to size because they're soft metals. Platinum on the other hand is quite hard. If you're increasing the size less than 1, you can probably get away with stretching the band as long as the shank (the round part of the ring) is thick enough. If you're changing the size more, or decreasing the size, then you'll have to cut the shank, add metal, and solder it. For the most part, gold and silver bend fairly easily. This is especially true for higher karat weights of gold. This is why a ring caught in a door might bend. Normal sizing can't stress the metal enough to cause it to fracture. The metal does warp because you're changing the circumference of the ring. This isn't usually noticeable unless there are stones set on the ring. If you're working with platinum, it's a whole different ball game because platinum has much more density and a higher melting point. Because of this, it often has to go to a specialty shop, which we aren't. I feel like this is pushing the limit of what a 5 year old can comprehend, but if you want more detail drop a comment. Source: jeweler's assistant",
"It depends on what the ring is made of and the aesthetic. Lot's of traditional jewelry metals are malleable, they can be reformed with relatively little force so gold 10+ rings can be stretched. But, frequently they are cut and reshaped."
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8j8qil | Why Are Drones Classed Differently to Remote Control Aircraft? | They are the exact same thing, they are both "remote" controlled. So why do they fall under different categories? | Technology | explainlikeimfive | {
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"The fact that they're quadcopters is irrelevant. Traditional R/C aircraft were limited to manual control within the operator's line of sight. If you couldn't see the plane, you were probably going to lose it. Drones, between their cameras and computers autopilots, have the ability to operate well beyond the line of sight of the operator.",
"Traditional remote controlled aircraft require a line of sight from the operator to the aircraft. Drones (depending on your definition of \"drone\") do not always require LoS, and some are autonomous or semi-autonomous."
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8j992p | Why does poking my amp cable against my guitar and myself (and presumably other stuff) play a radio station through my amp? | So I was sitting around messing with my guitar and I took the amp cable out of it. I started poking the metal part of the cable to the metal parts of my guitar, just to get that awful feedback noise and I noticed if I mute the strings I could actually hear the radio from my amp. I messed around with this a bit, and discovered that if I pushed the end against my hand (with another point of contact on my skin) I could hear the radio there too. What is happening? | Technology | explainlikeimfive | {
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"text": [
"A radio antenna is basically just a big piece of conductive metal that gets in the way of radio waves. Your amp cord is also a big long piece of conductive metal, and your body is 75ish kilograms of mostly conductive water. Cord + you makes a good enough antenna to get reception, and your amp turns those electrical signals into sound because that's what it's designed to do.",
"Others are on the right trail, but leaving out an important aspect. In order to hear an AM signal on your amp, it needs to be demodulated. AM demodulation only requires a rectifier (diode), and the circuit in your amp has a diode built into it. Both tubes and transistors can function as diodes. Two dissimilar metals can also make a diode. That's how fillings, fences, and other things have been known to receive AM signals. You probably could not hear an FM station because an FM demodulator is more complicated."
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8japlw | How do headphone jacks work? | Technology | explainlikeimfive | {
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"text": [
"A picture is worth a thousand words they say, so here is what happens when you plug it in: URL_0 Once you plug it in the two contacts you can see at the top are separated, this is then registered by the device and sound is redirected to the headphones.",
"Is there an ELI5 for how Apple uses the same port for headphones and charging?"
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8jb9bj | How do store shoplifting detectors know you are stealing an item that you haven't already paid for? | I am referring to the devices you walk through upon leaving a store like the ones in Target, Walmart, Walgreens and the like. | Technology | explainlikeimfive | {
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"Magnetic strip in the bottom of big items that's usually built into the cardboard, when you take it to the register and they push it over the scanner the magnetic strip is deactivated thus no longer tripping an alarm. Occasionally the strip doesn't deactivate and it'll go off but even then simply showing a receipt will send you on your way. I worked as a cashier at Walmart which is the system they have in place or did to prevent theft on items over $50",
"Modern versions are often using an RFID chip under a sticker somewhere, a few years ago they would have been a small bump but now they're undetectable from a normal sticker unless you see the backside of it (usually metallic).",
"Most places prolly have *security tags* that clerks remove after purchasing. If not, the gates will auto set off alarms you walk through"
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8jbwvq | How can be sound turned into digital? | Technology | explainlikeimfive | {
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"Through a process called \"sampling\". In this, the position of the microphone membrane (amplitude) is measured at a regular time interval and stored as a number. When reproducing the sound, these numbers are then converted into a voltage applied to the speaker - which then moves the same way the microphone membrane did. Of course, this process will inevitably lose some information. As a rule of thumb, all frequencies which are more than half of the \"sampling rate\", the amount of measurements per second, will be affected. That's why a sampling rate of 44 kHz is common in audio: Since it's higher than the maximum of 20 kHz we can hear, in theory it allows sounds to be reproduced without any loss."
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8jc3no | How does phone number spoofing work? How can two phones communicate without knowing each other's real numbers? | Technology | explainlikeimfive | {
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"The telephone system is both very old & very centralized (while also being decentralized). You could wire up a phone from 100 years ago to a wall jack and it would work (at least receiving calls). The phone doesn't even need to know there's a connection - there's no difference as far as it's concerned between picking up to a dialtone & answering a call. A \"ring\" is just a big voltage spike coming down the line. All the logic for how different phones are connected is handled by switching equipment back at the central office. Again, the phone doesn't \"know\" who it's calling, it just sends some beeping sounds down the line and the phone company does all the magic. If you're calling a phone in another city, those switches then hand you off to (potentially) another company's equipment to complete the call. With this in mind, Caller-ID numbers are kind of tacked on top of this giant legacy network in a very ad-hoc sort of way and there's lots of way to inject bad data into it. You can call somebody & then lie to their phone when the connection is made. You can set up a VOIP PBX and lie to the telephone company when you first make the call. I'm sure there's other ways it can work - I've not really kept up on the technology. The key thing is that Caller-ID was never designed with security in mind **and** it was layered on top of a much older system.",
"The phone number sent to caller ID is **not** the actual routine circuit number. That's because phone circuits are dynamically assigned, a throwback to before everything was just IP packets. It's just \"documentation\" to display on the caller ID device. The reason for this is that many companies have more extensions in their internal phone system than they have numbers assigned, or they simply want incoming calls to go to their operator rather than the phone on someone's desk. They set the caller ID for all the phone lines to their main operator to accomplish this. It's not a bug, it's a feature.",
"As others have stated here, the Caller ID displayed on older hard wired phones has nothing to do with the actual connection between your phone and the calling party. With the advent of cell phones, they just extended the existing services to work with the new technology. To my understanding, when you call sometime else, you provider makes a connection to the provider of the party you are calling ( based on looking up the phone number you dialed ) and says we have a call for \"x\". Oh, by the way, this is who is calling.... and they provide a data packet with your number, name, etc. If you own/run your own pbx, you can supply your own data packet, and as this information has nothing to do with billing, your provider will simply forward your data packet instead of supplying theirs. As someone else mentioned, if you have a VoIP line, you can generally just set the caller ID information to whatever you want it to be. Once again, no billing is done based on this information, so the telecom companies don't really care. For the curious, if you attach a \"butt set\" ( those phones the technicians use ) to a land line and have someone call the line, you can actually hear the small data packet between the first and second ring spikes. The caller ID, name display, etc was added on the existing infrastructure as a convenience to the end users, and has nothing to do with the connection itself."
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8jhu05 | Why are nuclear weapons so hard to develop if the technology for them has existed for 70 years? | Technology | explainlikeimfive | {
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"The hard part is getting enough weapons-grade uranium or plutonium, which is actually quite labor intensive and expensive to do, unless you have nuclear reactors - which many countries don't. Japan could build a nuclear bomb within a month if they wanted, and possibly sooner. So could any other country with nuclear power. This is why people are iffy about letting developing countries build nuclear reactors - they can be dual use into making materials for weapons. The other issue is delivery systems, like rockets/missiles, technologies most countries lack, and which are, again, fairly difficult to design/build, and have to be produced to high precision. There are instructions for how to build a nuclear bomb online, but good luck getting 10 kg of weapons material to build one with.",
"Developing nuclear weaponry isn't the hard part. At least, the most basic form of nuclear weapons isn't. The hard part breaks down into more or less the following two - The platforms. It's great you got a really jury-rigged [gun-type]( URL_2 ) nuclear warhead...except now how do you intend to actually use it? You need a body to put the warhead in (a missile), the right tech for guidance, decoys, extensive research into [anti-jamming/countermeasures]( URL_0 ) (Penetration Aids). On top of all of that, you need a means of actually launching and delivering it. This means either making silos [these are huge projects in their own right], or nuclear submarines, or any other means of launching them. Even then, you can't just have one nuke. You need a fair few to even put a dent into whatever target. So that means doing all the above research, then paying multiple times to get a platform, a launch system, and then multiple nuclear warheads. This all adds up in cost. - The second obstacle are *other nuclear powers*. This goes without saying, people won't like it when you start making your own nukes, especially regional powers, or international powers that don't like further arms races. Good luck dealing with them. Now, you get additional obstacles when you want a nuclear warhead that isn't relatively tiny and inneffecient. This means a lot more money going into research, materials, and testing. You need land, time, and effort for all of this in addition to the previously mentioned costs. tl;dr, the obstacle is not how hard it is technologically to make a nuclear warhead. The hard part is how much it costs, and all the *extra* stuff that's much more difficult that gets attached to the nuke. Even if you made an amazing nuclear warhead and had a missile strong enough to launch it, you need to make sure the missile has all the countermeasures it needs to fight off your targets [NMD]( URL_3 ) (Nuclear Missile Defense) which can include [multiple layers of intricate counter ballistic missiles]( URL_1 ) radar and other tracking methods.",
"The hardest part for a country is not to design or manufacture the bomb. The hard part is to manufacture the material. You need to enrich uranium to get uranium-235 or produce plutonium-239 in a reactor. In the Manhattan project they enrich uranium multiple way but the way that would work best but did not produce material until the war ended was gaseous diffusion method. There was at the high of construction 25 000 works employed > When it was built in 1944, the four-story K-25 gaseous diffusion plant was the world's largest building, comprising over 1,640,000 square feet (152,000 m2) of floor space and a volume of 97,500,000 cubic feet (2,760,000 m3). That is a building a mile lon 330 feet wide and four-story high building filed with pipes and pumps to enrich the uranium. A dedicated power plant was build to provide the electricity That is to give a example of the scale of the project in the 1940s. Today centrifuges are used but they are extremely hard to manufacture and you need thousands of them. So the way it is done today are not thec To create plutonium-239 you need a nuclear reactor and you cant hide that. So it is large costly project that you if you do it in the open other countries will tell you to stop and use economic sanctions etc to stop you. Another part is that is it relative undeveloped countries that tries to create nuclear weapons today. Iraq and North Korea are not manufacturing gigants with experience in manufacturing with extremely high precision, metallurgy etc. So it take time to develop what you need to build weapons. For a country that have the technology and experience in advanced manufacturing and civilian nuclear program the time to build a nuclear weapon is not that long. It is estimate that japan could have simple nuclear weapons within a year. They have the materials as a byproduct of the civilian program. They also have the other part you need a delivery system. Rockets from the space program with solid fuel rocket are what a ICBM. They have also build re-entry vehicle for the space program. Those are the part that North Korea have are developing today",
"It is not that hard. Even North Korea and Pakistan did it. Fact is, barely anyone is interested in obtaining nuclear weapons, and in fact about all nations signed treaties not to develop them. So the biggest hurdle is the diplomatic repercussions a nation would experience for attempting so.",
"I could build a gun type in my garage. The only hard part is refining the nuclear material, whether it be taking uranium and enriching it to a higher potential through gas centrifuges, or using plutonium by doing xxxxx and xxxxx xxxxx to make is fission/fusion material. That's the part that takes massive state resources and keeps it out of the hands of terrorist.",
"Develop is a misleading word. Any reasonably competent machinist could build the mechanical parts. And any reasonably competent electronic technician could build the electronic parts. And any reasonably competent chemist could mix the explosives. There are plenty of people who possess all the skills needed to build the entire nuclear bomb. The hard part is getting the nuclear materials. There are two basic type of nuclear bombs, gun type and implosion type. In a gun type bomb two pieces of U-235 are slammed together by placing a chunk of uranium at the end of a large gun barrel and shooting it with a bullet of uranium. The two pieces slam together and Boom! Simple, reliable, and dirty. There are some geometry considerations. The bullet is and target have to be shaped with specific dimensions. But these are well known. In an implosion type bomb, a hollow sphere of of plutonium is compressed with a shaped charge of high explosives. Once again there are geometry considerations and the tolerances are much tighter than in a gun type bomb and there are a few other things required. But, as in the gun type bomb, these specifications are well known. So since both types of nuclear bombs can easily be built, it all boils down to getting the nuclear materials. Implosion type bombs require plutonium-239. PU-239 is a material that does not exist in nature. PU-239 can only be produced in a nuclear reactor. So, in practice, any country, or person for that matter, that has access to a operational nuclear reactor can synthesize the necessary plutonium isotope. Once you have a functioning reactor it is relatively easy to produce plutonium-239 as a byproduct of generating electricity. Such production can be done clandestinely and no one outside the nuclear power plant would any clue what was going on inside. That is why there is such uproar and consternation over rogue countries having access to nuclear power. Having nuclear power means you have the ability to build a nuclear bomb. Gun type nuclear bombs are even simpler I would hazard a guess that almost any person who is mechanically and electrically intuitive could make a gun type nuclear bomb. But once again getting the nuclear material, uranium-235 is the problem. Uranium itself is relatively easy to find and extract from the ground. However, 99.3% of mined uranium is U-238 which is not usable in a bomb. A gun type bomb requires U-235 which is only .07% of all mined uranium. Since the U-235 is mixed with the U-238 you must separate the two. And since U-235 and U-238 are nearly identical in appearance chemical composition and weight, separating the two requires either a insanely large and expensive gaseous diffusion facility or a insanely large and expensive centrifugal separation facility. Such facilities would be impossible to hide and would clearly show that a country was intent on building an atomic bomb. Bottom line: Building an atomic bomb is easy, getting the nuclear material is not."
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8jji00 | How does identity theft work? Is it common, how can i avoid it and protect myself? | Technology | explainlikeimfive | {
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"It’s basically someone getting hold of enough info to open lines of credit in your name. Social security number, birthday, mother’s maiden name, etc etc, all that info can be used to open a credit card in your name, which they then can use, leaving the debt collectors looking for you instead of them. To avoid it, don’t enter sensitive info on public WiFi, shred documents with sensitive info (or burn them, even better), never give out info to anyone who calls you. If they claim to be an official, ask for their department and name and call them back to prove they are telling the truth"
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8jl8yo | how does artificial hearts work? | How does artificial hearts really function and more specifically deal with the various heart relates that go along with daily life and exercise? | Technology | explainlikeimfive | {
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"text": [
"[Artificial Hearts]( URL_0 ) are just pumps. They have motors to pump the blood and have batteries. If you're imagining that a person can get an artificial heart and then lead a normal life, that's not currently the case. For two reasons: * The body's immune system has a severe rejection reaction to any foreign bodies or materials that are inserted in the body cavity. An artificial heart has to be hooked up to the arteries and veins, and comes in contact with blood, and the immune system cells are also in the blood, so eventually there's a severe inflammation and rejection reaction in the blood to the plastics and metals of the artificial heart. * Motors and electronic circuits can be made small enough, but currently our battery technology is pretty crappy. For a small (laptop-sized) portable battery, you get a few hours of use then have to change the battery; for continuous longer duration use you're pretty much permanently wired to a wall socket or a bulkier battery pull-along. So, basically, currently artificial hearts are used as a temporary measure while a patient is waiting for a real heart to be available for transplant. In cases where the implant is not possible or the heart must be long term, mobility of the patient is severely restricted by the battery/power system that must have many failsafes and backups, so that it can continue functioning in case of power outage. So, basically, people who are on an artificial heart can't really have a normal daily life with exercise and sports and outdoor activities."
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8jn7u0 | Why do credit card scanners have to ask "credit or debit" instead of figuring it out automatically from your card? | I guess a follow up question is: why do some machines ask you, and other machines don't ask you? | Technology | explainlikeimfive | {
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"It's a network routing thing. If you're using a debit card (tied to a checking account) and select \"Credit\", it routes through Visa/Mastercard/Whatever and ask for a preauthorization from the issuing band or credit union that will be settled/posted to your account later. If you select \"debit\", it'll route through a network like STAR/AFFN/Plus/etc and most likely require a PIN and will be settled/posted to your account immediately. (I work in the industry)",
"Here in Canada a lot of the machines don't, particularly tap and go can be enabled on both debit and credit card, and you don't have to choose anything before tapping.",
"You can run a debit card as a credit card and the money will still come off of it but it will take a bit longer, like a day or two. That's all I've seen as the difference. Oh and no cash back options. As to why, I have no idea.",
"Typically because the machine has to connect to a different endpoint for the two services. If you leave the option to the cashier to choose which system to check into, it is future proof. If instead you try and make a complex system where you know different banking systems number formats for Credit Cards vs Debit Cards, it needs to be updated every time a new range is declared. Sure, they are connected online for the submission, but they are also incredibly highly regulated, so pushing updates to card machines is a bitch. If you want to spend the resources to do the 'nicer' way, then you pass the cost on to the store using the machine. Are they going to spend that much more cash so their cashier doesn't have to ask 'debit or credit' ?"
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8jnaw6 | How do they make old(er) movies in 1080p/4k? | Technology | explainlikeimfive | {
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"text": [
"Generally speaking, many of those older movies were shot on film rather than being captured digitally (in fact, most movies are still shot on film then transferred to digital mediums in post production). Film has a _very_ high resolution - much higher than 4k. All they need to do is go back and transfer the film to digital again to capture it at a higher resolution, then reedit/rerelease."
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8jnp5n | Why do schools buy macs but install windows on them? | Technology | explainlikeimfive | {
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"text": [
"I genuinely have never experienced this, but probably because windows is a more familiar platform for the general public, and all the school programs are probably windows formatted. Something along those lines, i’m explaining like you’re 10 and not 5, sorry."
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8jqv2c | Why do more and more websites seem to be eschewing the standard "confirm password" format on account creation? | I've noticed on several websites that I have created new accounts on that they ask for Username, Password, Email, and whatever else they need. I am not being asked to confirm my password, however. In the past I assumed that the reason for this is so that I am sure I know what I set my password as, but what reason is there for removing this feature? | Technology | explainlikeimfive | {
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"If you forget your password they can always reset the password by sending it to your email address. This is why you may only see one field for the password but two for the email as it is more critical that you get that right. Removing any unnecessary aspects of the account creation can make it easier and fast to make an account, increasing the number of accounts registered overall."
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8jrf4p | Why hasnt the technology in news rooms been able to figure out how to get rid of the delay between studio and field anchor communication; shouldn’t that be easy to solve in 2018? | Technology | explainlikeimfive | {
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"Alot of it has to due with latency ( the time it takes for the data to get from one point to another). That's why when the news has someone on satellite phone there is a second or 2 delay. The Satellites that we use for TV are in geosynchronous orbit, which is 35,786 km (22,236 mi) above Earth's equator, and the size of a large pick up truck. Now think the data has to travel up, and back down, then up and back down to you. That's pretty far.",
"Light only travels so fast and we currently don't know how to send things faster than light.",
"It isn't a technological problem. Satellite communications has noticeable lag because it takes a while time for a signal to travel to a satellite and then back down. Most communication satellites are in geostationary orbit at an altitude of about 35,000m above the equator. It takes light about a quarter second to travel up to a satellite and back down."
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8jtylj | What makes some game consoles easier to emulate than others? | Zelda Breath of the wild can be played on the PC using CEMU, and has been for some time now. It was emulated far quicker than any Xbox or Playstation game. Why? | Technology | explainlikeimfive | {
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"Usually the cause is the hardware used in the console. Newer consoles use the so called X86 Architecture for their CPUs, that's also the one used in your Computer, so those are often easier to emulate. The PS3 for example used a Cell processor if I remember correctly, so giving PS3 CPU instructions to a X86 CPU will most likely not work, so you first have to create a program capable of helping the X86 understand what it has to do. On top of that there is a big chance that hardware tricks are used on the PS3 to make it go faster, which might be even more taxing for a X86.",
"BOTW uses the Wii U’s version, right? I’m not sure how easy it would be to emulate the ARM instructions of the switch. It comes down to hardware mostly. Not too long ago, we just started getting enough power in most computers to accurately emulate SNES. Accuracy takes a massive amount of processing power. Emulators that don’t take that seriously have an easier time, because they can use hacks for performance. The issue with that comes when a programmer ties code to an aspect of the hardware that doesn’t get accurately emulated. This can cause a game to not work for those particular edge cases. In an instance where the hardware is the same (XBone, PS4), it’s much easier to emulate or port games between platforms."
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8jummj | It takes about 45 minutes to charge my phone to 90%. Then it takes another 45 minutes to charge to 100%. Why? | Technology | explainlikeimfive | {
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"text": [
"Pour a glass of water right to the top. How fast did you fill it at the bottom, and how fast did you fill it at the top? It probably took you just as long to fill the first 85% of it as the remaining 15%, because you were very careful at the top. Essentially, the batteries can take the higher charging rate when they're empty, but if you try and pump the juice into them, it will damage the battery, just like if you tried to pour a perfectly full glass of water at the same fast rate, you would spill all over the table."
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8juq9v | Court stenographer machines can capture entire conversations in real time but no one uses them as computer keyboards? Why? Are they harder to use? | Technology | explainlikeimfive | {
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"text": [
"[A stenotype machine]( URL_1 ) isn't just a quick way of typing, it's also a form of [shorthand]( URL_2 ). It's not a 100% accurate way of recording things, it's just a really good way to capture things quickly. You have to do some work after the fact to make it readable. There are [chording keyboard]( URL_0 ) layouts but they're not particularly popular because it's much harder to learn key combinations than a 1:1 connection between symbols and keys.",
"They are harder to use because the user must know shorthand and know how to use the keyboard. People usually needed professional training in order to learn and use a stenography machine. There are less keys, and you have to press multiple keys at once to “spell” the shorthand words. It’s like having to learn a new language combined with learning a musical instrument. With a typical QWERTY keyboard, the user just needs to know how to write in their language, making it incredibly user-friendly and accessible. A stenography keyboard requires training and entirely new skillsets."
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8jwdie | Why do F1 cars and other true race cars generally have relatively thick profile tires with a small diameter rim while almost any sports car you can buy has low profile tires? | Why is this? This occurred to me when I was admiring and old school sports car with thicker profile tires. I like that look and thought, wait a sec, F1 cars have tires just like that! I’d love to know the reason. Looks aside, low profile tires would seem to make more logical sense in racing to me. | Technology | explainlikeimfive | {
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"The biggest problem with race tires is actually heat buildup. By having more surface area in the sidewalls .the tire dissipates heat more efficiently. Passenger cars don’t really have the same problem.",
"F1 mandates 13 inch rims. That's the reason the tires have to be so tall. They are actually debating changing the rule to allow larger rims and lower profile tires. If you want to see what that might look like, check out a [Formula E (electric) car, which isn't restricted to 13\".]( URL_0 )"
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8jww6m | How do slot machines work, and are they truly random? | Technology | explainlikeimfive | {
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"text": [
"Past ones had a physical mechanism that would spin the reels by you pulling the lever. Modern electronic ones work the same as any other computer, with a random number generator (which is technically pseudo-random, but for all intents and purposes is essentially the same as \"true random\") running in the background that is used to calculate the given results of a pull on the fly when you pull the lever. In the US at least there is requirements that said generator be cycled in the background (to prevent timing it) and that odds on electronic slot machines be \"constant\" (meaning that a machine can't go \"quiet\" after a payout, for example). (In the event of simulated versions of physical games like roulette they also require the odds to match the physical game version).",
"No, they are not truly random anymore. Yes, they are pseudo-random to sufficient accuracy that their results don't differ from true randomness by a significant variance. You can't just make a slot machine and sell it to a casino. These are highly regulated devices that are scrutinized in detail by the state regulators. Algorithms are examined, and tested, and making an unauthorized change is a serious crime."
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8jy73x | Why do HD movies go blurry when paused? | Technology | explainlikeimfive | {
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"text": [
"They don't always go blurry when paused. It depends on what that specific frame looks like. Often when movies are filmed they have blurry frames because that's what naturally happens when something on-screen is moving or when the camera is moving.",
"Blur is often added to animation to make it look more natural as well so if you freeze the frame you see it but it blends in when looked at in motion"
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8k4bob | Why do tinted windows almost look like a grid when you wear sunglasses? | Technology | explainlikeimfive | {
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"Polarization. Simply put: Sunglasses with polarized lenses align the light in one direction. The tint is an imperfect film that has certain polarizing effects on light as well. When you have the shades on, you’re able to see the alignment of the tinted application. Try this with cheap shades. You won’t see anything. Any sunglasses with polarized lenses will show off other polarized items. Even the aftermarket screen protectors on some phones are polarized, you’ll see the pattern as well.",
"Light travels as a squiggly line, going up and down, side to side or in any other diagonal direction. A polarization filter is basically something with very tiny slits in it that only lets light pass if it squiggles in a certain way, blocking all other light. Now if two filters are behind each other, it depends on how the slits are angled to each other. If they are nearly the same, lots of light pass through both. If they're different, less or even no light at all passes through them both. Now, glass is made in a way that polarizes light, which changes throughout the pane. If you see light polarized through glass through another polarizing filter, like a good pair of sunglasses, the different angles make that pattern visible because different amounts of light pass through.",
"Spots on glass are caused by the glass in that spot being under direct contact from a cooling fan and the glass cooling quicker in that spot. Thus altering how the light waves pass through those spots, which is noticeable through polarized glasses. Not related to the tint. This is only the case on tempered automotive glass (anything that isn’t a windshield) due to the manufacturing process. This is why people associate the “spots” or “grid” with tint, since people don’t normally tint windshields and only tint the tempered glass. Source: work for an automotive glass manufacturer.",
"The grid is caused by the tempered glass. The tempering process places a grid pattern of stress in the glass itself. Those regions of stress cause light to twist as it passes through. Your polarizer lets you see those patterns of twists. If you go to Google Images and search for \"polarized light stress analysis\", you'll see some beautiful images of this effect. This [stack exchange article]( URL_0 ) has a photo of this effect that probably closely matches what you're seeing. I don't know what window tinting has to do with it unless it served to darken the glass enough to let the grid pattern be obvious."
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8k4ogh | What is a GPON SFP? | Technology | explainlikeimfive | {
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"A GPON SFP is a gigabit passive optical network small form-factor pluggable transceiver. It is the adapter to connect to your internet connection and it is unlikely to belong to your roommate, as it is probably owned by either your internet service provider or your landlord."
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8k7yw7 | How do photocopiers actually work? | Technology | explainlikeimfive | {
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"Printers work by translating digital images into a set of instructions for a printer head to move across a piece of paper, depositing ink where appropriate. Photocopiers often use a different technique, called xerography, where the light/image from the original being copied causes a reaction on a photosensitive plate or roller, this reaction causes toner to stick to the plate in appropriate areas, and is then transferred to the copy."
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8k9ccr | When rock climbers use the hardware to climb and they nail them into the side of the mountain, are they retrievable or lost after use? | Technology | explainlikeimfive | {
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"There are three main types of hardware used. **Pitons** are hammered in, and left there. You can't re-use old pitons that you find, because they suck, and may have started to work their way out from freeze-thaw. In any case, almost nobody uses them anymore. **Bolts** (with hangers) are permanent fixtures. They are re-useable, but they are drilled into the rock. **\"Trad\" protection** is temporary, and consists of things that get jammed into cracks in such a way that falling won't pull them out. This includes cams, hexes, nuts, and a couple varieties of specialty hardware. EDIT: I forgot that pitons are still used in \"aid climbing\", where one actually puts weight on the gear, rather than using it only to protect against a possible fall. I don't know anybody who does it; I suspect that aid climbing is sufficiently rarified as to fall into the \"hardly anyone\" category. :-)",
"Most climbers these days use temporary protection in the form of cams (friends), nuts and ice screws. Usually people climb in pairs so one climbs placing protection in cracks and other secure points (leading) and their partner stays at the bottom and keeps the rope tight (belay) until the lead climber reaches a secure rest point and takes control of the rope. Then the belay climbs up to the lead, removing the protection (except the topmost piece that the lead is belaying from) along the way. They then continue up in the same fashion, sometimes leapfrogging each other to swap roles until they reach the top.",
"Sport climbing equipment involves quickdraws which are retrievable immediately, but they're clipped into previously placed bolts which are not. Sport climbing bolts are still removable but only with proper power tools. Trad gear is temporarily placed into cracks for protection and are removable afterwards. Pitons are rare and are hammered into the wall, semi-permanently.",
"As others have mentioned 'pitons', pronounced 'peet' and 'on' (the way it sounds in 'con') have not only been used scarcely in the past few dacades, but are highly frowned upon pretty much everywhere nowadays, as they are frequently not retrievable and also damage the rock feature they were in contact with, making it more difficult to use for the next climbers.",
"Trad protection can be recovered, but it can be dangerous in some situations. My climbing partner almost got himself killed making the mistake of trying to recover all but the top one on his way down, as he could not make it all the way up the cliff. The top one came out when he was a few meters above the ground, fortunately not earlier, so he survived. Although he had to be helicoptered out with a spine injury and never climbed again.",
"So as a side question, is there any conversation in the rock climbing community about leaving hardware behind as “littering”? Most outdoor sports & recreations try to conserve their environment.",
"Back in the day, people used to hammer in or \"nail\" hardware into the cracks of the rock. These were called Pitons. They were sometimes left in and sometimes removed, but in spots where they were put in and removed repeatable, they caused damage to the rock and changed it. Because of this, they are not very common any more. Modern climbing has two \"styles\" of using hardware these days. The permanent style attached the hardware permanently with either glued in or expansion bolt hardware. Climbers bring their own temporary hardware to use with the permanent gear and then typically remove it when they're done. The temporary style uses a variety of gear that is designed to be removed after use. Sometimes this gear gets stuck though and becomes a part of the rock for a long time.",
"This has got to be one of the most informative and easy to understand ELI5s I've ever seen. Thanks, climbers!",
"They did a documentary that will tell you everything you need to know. It’s called Cliffhanger.",
"Climbers rarely \"nail\" anything in, and I'd say most popular form of climbing these days is bolted sport climbs, as they're easier to lead, and similar to what you'd find in a gym environment. This means someone went up to the top of the cliff with a hammer drill, some [bolts and hangers]( URL_3 ), then setup a rope and rappelled down to drill holes and install the bolts on the way down. To climb this after it's bolted you bring [quick draws]( URL_6 ) and a rope, as you go up you clip one end of the quick draw to the bolt (which has been permanently affixed to the rock), and you clip the lower end to your rope (which runs down to a belayer who catches you if you fall.) Then when you're at the top, you can either be lowered down, or rappel on the rope. The second person that goes up doesn't have to worry as much about falling since the rope is now above them rather than below, and as they go up they unclip the quick draws and bring them down. When you're done you feed the rope through some chains or rings that are permanently attached to the bolts at the top of the route and then you rappel down the rope. There's another less destructive method of climbing known as trad climbing, where there are no bolts setup along the route, you have to use the features that are in the rock to hold gear such as [cams]( URL_4 ), or [nuts]( URL_2 ). It's quite a bit more dangerous than sport climbing as you need to know what a good gear placement would be, and gear can more easily pop out as it's not permanently affixed. The leader has the more dangerous task of going up first and placing all of the gear in the hopes that if they fall, they will at least be caught by the last piece of gear they placed and clipped the rope to. The belayer typically goes up after, and removes all of the gear that the leader put in, except the anchor (the top most section of the climb a leader will setup a few pieces of gear as an anchor and that is what's used as protection for the rest of the climbers in the group.) The only time you would ever find yourself using [pitons]( URL_0 ) (the steel pins you would \"nail\" into the side of the mountain) is during an aid climb up something like [El Capitan]( URL_1 ) in Yosemite. Aid climbing is basically like trad climbing, except instead of climbing by using your hands to pull yourself up the rock, you place pieces of gear, clip the rope to that, then climb that length of rope. It's a slow process, and sometimes you find yourself climbing a very narrow crack where you really can't get any good gear in, so you could hammer in a piton instead. You can actually remove pitons (and it's rude to leave them) by using a [special hammer]( URL_5 ) with a hole in it that you can clip to the piton and hammer AWAY from the wall. The force slowly pulls out the piton and you can reuse it further up the climb. Often times when you're trad climbing, you might find a piton that couldn't be removed from decades ago (50s and 60s), these are just permanently stuck unless someone goes up and cuts it out of the rock. I've clipped those before, when you're lead climbing and you feel like you're about to fall, and you know your last piece is 10 feet away (which means you'll fall at least 20 feet), it just feels really good to clip something even if you know it'll probably break.",
"There are 2 types of climbing. Sport and trad climbing. Spot involves someone drilling a long bolt into the wall where you can attach a karabiner. The bolt stays in the wall and can not be removed. Trad climbers use a series of hardware that fits in any size crack and is left there for the last person climbing to \"clear the route\" where all the gear is retrieved Sport climbing is good because it is relatively inexpensive. But it is bad for the \"health of the wall\" Trad climbing is good because it allows the climber(s) to be more creative on the wall, they can pick any route. Its bad because its very expensive to own and replace climbing hardware.",
"To add on to what others have said, another distinction to make is “free” climbing vs “aid” climbing. In free climbing, the rope and protection (bolts or trad gear) are only used to catch the climber in the case of a fall. In aid climbing, climbers use the rope and protection to hold/pull themselves up while they place the next piece of gear. Free climbing is not to be confused with “free solo”, which you might have hear of someone like Alex Honnold doing — that’s where the climber uses no rope or protection at all, so there’s nothing to catch them if they fall. That’s extremely rare and most climbers don’t free solo, so don’t think they’re all (completely) crazy!"
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8ka0iz | Why does satellite radio work fine in storms but satellite tv always has issues? | Technology | explainlikeimfive | {
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"Redundancy in the signal and the frequency of the signal Satellit tv is design to work fixed receivers with line of sight to the satellite. . The use signals in the Ku band frequencies (12–18 GHz) that work fine for a small dish with clear sight the to the satellite Satellit radio is design for portable receivers primary in cars that done always have line of sight to the satellite and can't use a dish put a regular antenna. So they use a signal at 2.3 GHz that can penetrate building etc in a way 12–18 GHz) cant. The higher the frequency the more solid material block it The signal is also different. For TV you have always good reception (except ion a storm) so you use the signal to send more channel. In radio the reception with differ so the signal is designed so for exempel if you only receive 80% of the signal you can reconstruct all information. That type of signal can carry a reduce number of radio station but there is less risk that there is bad reception. So a system designed for reception behind object where you can miss part is works in a storm as that is one type of blocking and distortion of the signal. A system for fixes antennas with good reception are more sensitive to the interference by a storm"
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8kachu | Why is a number 2 non-mechanical pencil required for standardized tests? | Technology | explainlikeimfive | {
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"The #2 pencil is a mid-range softness for pencils, about an HB hardness, it is a pencil that can leave a dark mark and maintain a semi-sharp point. On the HB scale the higher the H number the harder the lead, the higher the B number the darker the lead, F and HB are the mid lead, but HB leaves a darker mark than F and F tends to hold a sharper finer point, and thus the reasoning behind the numbering. You don't want an F or H lead in a pencil on a bubble test because the paper might tear from the sharpness of the pencil and the H leads would increase the likelihood of the paper getting cut, and make it hard to give a well defined dark mark on the paper. You also don't want a B level lead because these are softer leads, and though these leads would leave a dark enough mark they lose their point quickly, and if soft enough will leave unwanted and accidental marks on the paper. That leaves the standardized HB lead, which as it turns out was chosen for #2, it holds a nice point and is soft enough to leave a controllable dark mark.",
"Scantron machines detect marks based on a set range of reflection when a light is shown over the paper. They are calibrated to detect the ranges that a #2 pencil has. Different numbers are different hardnesses and their marking reflect light differently because of this. So if you do not use a #2 pencil then it is more likely that the scantron will misread the paper and mark your test incorrectly. As for using non-mechanical pencils, that is to ensure you are using #2 lead as you can refill a mechanical pencil with the wrong lead. But this is mostly for older tech. If the school you are in uses a newer scanning machine they can read just about anything, but the older standard is firmly established and since many schools still have the older equipment it is easier to just keep the older requirement. #2 pencils also have the advantage that they can be erased fairly thoroughly while still leaving a fairly dark mark. Lighter grades will erase easier, but will not be as dark (see the first paragraph for that issue) and harder grades will be more difficult to erase so may show errors when you grade if you change an answer."
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8kay1d | With all the advances in computing, why are email servers still so limited on file attachemnt size? | Technology | explainlikeimfive | {
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"They're not. Your service provider or company imposes it's own limitations to conserve network bandwidth.",
"It is not a limitation, it is a decision. One of the truest maxims in IT is that users are idiot. If you allow a certain size of an email attachment, someone is guaranteed to try to send emails of that size...over and over and over, to as many people as possible. Bandwidth and storage space might be pretty cheap, but if you try to email a 2 GB movie and cc a hundred people, those resources get chewed up pretty quickly. Also, sometimes those resources are not cheap. If you are on your phone and you click on that attachment, that can be a pretty good chunk of your monthly bandwidth."
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8kbux4 | Why do computers/processors get faster while their speed (GHz) stays the same? | Hey wo i was wondering because the intel core 2 duo quad processors already got speeds up to 3 ghz per core. And I. The last 10 years it looked like the numbers stayed the same between 3-4 ghz per core. So how did computers got faster while the number of processing cores and speed(Ghz) stayed relatively the same? | Technology | explainlikeimfive | {
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"There's not only clockspeeds. The biggest improvements besides more cores are the numbers of instructions processed. This is called the IPC (instructions per cycle). Think of it like when you're coming home from grocery shopping with a car loaded with groceries. Clockspeed determines how long it takes you to carry things from your car to your fridge. IPC determines how many groceries you can carry in one trip. So a 3,4GHz CPU from 2008 might also need 30seconds from the car to the fridge, but it can only carry the bread and eggs while a 2018 CPU can carry the bread, eggs, bacon and soda at the same time. Additionally newer CPUs have more cores. So you're not carrying the groceries alone but got your brothers and sisters helping you. So instead of you doing 4 trips from the car to the fridge and back, you and your 3 siblings carry the stuff simultaneously so you only have to take one trip. Additionally you can save time if you carry the groceries to the fridge in the order they should be put in it so you don't have to reorganize everything in the kitchen. So you gotta anticipate the correct order. Modern CPUs got much better at predicting what's going to be next. All in all, this boosts overall performance. That being said, compared to the development in storage and graphics processing, the innovation of CPUs has slowed down a lot in the past years.",
"Kind of like how family cars go from having engines with 60 horsepower revving up to say 6000 rpm, to today having 150 horsepower while still revving up to 6000 rpm. It's not the speed of turning the engine, but what happens at every turn of the engine that gives it more power.",
"They’ve gotten more cores, the standard now being 4. To go along with that, the have more stuff like cache, which is ultra fast ram like memory that sends information to the processing unit, along with the newer designs being more efficient and more optimized for modern workloads.",
"The maximum clock speed that a computer chip can reach is determined by the time it takes for an electric signal to travel from one stage to another. So for example, you have one stage of the CPU that gets two numbers from the previous stage, adds them up and passes them to the next. All this has to happen within one clock cycle, so the highest clock rate you can reach is determined by how long this takes. All these stages added together are called a \"pipeline\", and the pipeline length is the total number of stages a CPU has. (Edit) The longer the pipeline, the shorter each stage, so a longer pipeline means that the CPU can run at a higher clock speed. Now for a very long time, the CPU manufacturers used to add more and more stages to their CPUs as the manufacturing process became smaller and smaller, doubling clock speed every few years. But starting in the early 2000s, this approach reached its limit: The increasing pipeline length had a negative impact on performance and efficiency. So even though the intel Pentium 4 Prescott CPUs managed to reach extremely high clock speeds (almost 4 GHz, more than that with overclocking), they weren't very fast. At that time, AMD processors - with lower clock speed - were substantially faster and used less power. Since that time, both intel and AMD focused mostly on increasing the processing power per clock, as well as increasing the number of cores on their CPUs, with a drastically reduced pipeline length compared to the old Pentium 4 CPUs.",
"5 year old version: smaller and cheaper parts that do things means we have more total parts, which means more output 10 year old version: cost of both “memory” (cache) and transistors has gone down, but the biggest thing probably is the physical size. More cache basically means *individual* tasks take less cycles. But because the transistors are smaller now, we can fit more of them in the same space. Because we can fit more of them, we can do more operations in the same time. Thus clock speed stays similar, but since we are doing more things per clock cycle the performance *as a whole* increases. If that’s confusing, think of the cpu as a factory and transistors as workers. We now have more workers, so the factory outputs more per day even though the day is still 24hrs. More cache is like adding conveyor belts instead of workers going out and picking each item off the shelf to assemble",
"Parallelisation. Not only do we have multiple cores but each core can also do multiple operations in parallel, allowing it to execute more than one instruction per clock cycle. For example, if your code says to do an addition and then a multiplication of (independent) numbers the CPU can do both at the same time, if enough execution units are available. To do this efficiently it’s important to have Out Of Order Execution (execute instructions in a different, more efficient order than your code says, but still have them behave in the same way). With SIMD (single instruction, multiple data) it’s also possible to e.g. multiply four numbers with four other numbers at the same time. This is advantageous for things like compression or video encoding where you want to apply the same operation to lots of data. We’ve also gotten better at branch prediction, that is, guessing which branch your code will take on an `if` instruction. CPUs nowadays are much more complex than in the good old days. They are no longer fetching and executing one instruction after the other. Instead they are re-ordering instructions, executing them in parallel, predicting branches, prefetching data, sharing their caches and much more. With each new CPU generation lots of work has gone into making those strategies as effective as possible while still keeping price and power consumption low. All these improvements mean that the CPU can process data much faster. To supply that data it’s important to have fast memory. RAM (the main memory with sizes in the order of several GiB) speeds have gotten faster, but not fast enough. This made it necessary to add caches (fast, small memories, sizes in the order of MiBs) directly in the CPU to have the data you are currently working on quickly available. I’d also like to point out that clock frequencies haven’t stayed the same. For example the new Intel Core i7 8700K can reach speeds of up to 4.7GHz if only one core is active, and up to 4.3GHz if all cores are active. AMD’s latest CPUs increased clock frequencies by 6% over the predecessor.",
"Imagine one of those ancient Roman galleys crewed by slaves, with a big burly dude beating a drum to set the pace and all the slaves rowing to the drum beat. The speed of this beat is basically the clock frequency of a processor. It tells the rowers how fast to row, but depending on the ship and the number of rowers and the oars they're using and the navigator and a dozen other factors, the resulting speed of the boat can vary. If you want the galley to go faster, then instead of beating the drum faster, maybe you'd be better off just getting more slaves to row. Or buy stronger slaves. Or give them bigger oars that can move more water with each stroke. Or get a better navigator, who knows the currents and can guide the ship so that the currents will do more of the work for you. The clock rate is just the beat that the entire processor marches to. At 3GHz, there are 3 billion beats every second. But that says nothing about how much work is done per beat. Pretty much all operations actually take multiple beats (called clock cycles) to execute, so if you were to increase the clock rate to 4GHz (an improvement of 33%), that would lead to a 33% improvement in performance *only if* all operations still took the exact same number of clock cycles. But most likely, because each cycle is shorter, many operations will now take more cycles to complete than before, and so the computer might not have gotten any faster after all. Conversely, even while keeping the clock frequency fixed, you can improve how much work gets done within each cycle. If you can make it so an addition finishes in 13 cycles instead of 15 cycles, you've improved the performance of additions by quite a bit, without needing to raise the clock frequency. If you can make it so the processor can do four additions at a time instead of just three, you've improved performance, even if each addition still takes as long as before. Additionally, modern processors have multiple cores. So imagining the same galley, if you needed to move a thousand soldiers to wherever you were thinking of invading, then instead of getting this galley to do a dozen trips as fast as it can, maybe it'd be more efficient to just have a dozen galleys. It's not that the individual CPU cores (or galleys) are faster, there are just multiple cores, each of which can work on their own thing, sharing the load, so overall, the work gets done faster."
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8kf5by | How did AutoCAD become the industry standard for drafting when it is horrendously buggy and prone to crashing? | I’ve used a lot of post-2010 versions of AutoCAD over the years in a variety of offices and at home. It’s the buggiest program I’ve ever used by far. Even sometimes something simple like editing a text box makes the whole program crash to desktop. Looking around on the Autodesk website and other forums shows me this is well known about AutoCAD. How did it become the standard over other CAD programs despite this huge cost in productivity? | Technology | explainlikeimfive | {
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"I used the Autocad 13 version in the early 2000s at school. It does not matter how buggy it is if it is the only program available, or the program that managed to get into the school. It was one of the first digital drafting programs to gain any kind of success, and they cut a lot of price deals to get into schools meaning that they got firmly established before their competitors could. Once a school is dedicated to a program ecosystem it is not easy to switch, even if it is buggy. And while it was buggy for us, it was better than the other option which was drawing by hand.",
"I don't particularly like AutoCAD, but have you used any of its competitors? Believe it or not most of them are even bigger pieces of shit. Far, far bigger.",
"Is this even true? I think it greatly depends on the industry. In the aerospace industry CATIA from Dassault is far more standard than AutoCAD for example.",
"In the early-mid 80s there was very little competition in the field, and AutoDesk sold its product better. Not just 'marketed': While its main competitor Microstation was a more solid product directly out of the box, AutoCAD was much more customizable, which allowed its adopters to quickly and easily specialize it for their own industries - a major point in opening customer doors. This means a large chunk of numerous industries took it up as their standard, which carries high inertia: It's what the veterans who today may only have recently retired used, it's what they taught the rookies. Autocad was what you had to learn to use for your work, and was the program you're most likely to have first trained with/on in school to begin with. That adds up! Additionally, while it certainly does have its troubles, for quite a few applications it's much faster in its hybrid-2d form (CTDs included, just save often) than many of the 3d modeling programs, especially once you're used to it. The full 3d modelling CADs are often more powerful yes, but not without some bugs of their own. So until you absolutely need that difference chances are your company will stick to the fast option that doesn't cost retraining and that everyone in it already knows.",
"Once it's a standard, there are obvious reasons to stick with it. Another program may be better long-term but *actually switching* is costly and inconvenient. **At the time** it first became a standard... It may have been less buggy since there were fewer features, and few/no updates had occurred for compatibility etc. Competitors may have been equally buggy since it was a new concept/tech at the time. Or competitors may not have existed yet.",
"i can't cite anything other than what my dad has told me, but he was in college in the early 80's and he attributes their success to getting into classrooms early.",
"AutoCAD is the worst drafting tool in the world. Except for all the others. This is actually a very common problem with niche software, medical software has similar issues. They might be the industry standard, but they are never going to sell to millions of new users like Microsoft does, nor are they going to lock users into a whole family of sister products, nor do they have alternate revenue streams like Google. Yet their software is just as complex, and has to be supported with fewer resources. Also, professional drafting tools are complicated and have a steep learning curve, that is just the nature of the drafting business. Users who have put in that sort of investment are going to be sophisticated enough to work around a lot of glitches. Also, they are going to be less willing to throw away that investment and try to learn another tool. Finally, piracy is a big issue, especially outside of the US. Microsoft doesn't really care if you pirate their software, they see today's pirate as being locked into their platform and becoming tomorrow's customer (ok, they do care a little, but this is largely their philosophy). AutoDesk basically sells one primary product with a million extensions, and it is a standalone product that doesn't rely on a lot of interconnectivity. That makes it pretty easy to pirate, further cutting into their revenue."
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8kfvk4 | Why is it that we have 4k TV and VR technology, yet for half of the shows and movies I watch, I have to constantly change the volume and/or bass and treble settings throughout the whole thing? (Quiet talking, ear piercing music and action) | Technology | explainlikeimfive | {
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"I disagree with a lot of the posts here. It's not because someone did a bad job. It's because that's how the content producers wanted the audio to be. You are supposed to turn up the volume and 'experience' the movie or show how they intended. Think of how crazy loud the bass is at a movie theatre. That's what they like. I hate it too, because most of the time that's not how I enjoy listening to my tv, but it's not an accident.",
"Even better comparative question: Why is the sound quality of a 2018 cellphone conversation that of a WW1 era CB radio???",
"Motion picture audio engineer here. The short version is that every device is tuned differently and you can’t possibly mix for all of them. See, the mix that we do on a stage is meant for theatrical release. This mix meets certain standards for audio levels and dynamic range set by standards bodies like SMPTE, AMPAS, etc. A slightly different mix is done for distribution, but again meeting certain standards. For TV we may do a big 5.1 mix and a “near field” mix for smaller TVs. Both of these mixes conform to a certain standard. The problem is that these standards are based on a certain listening environment. If you have a home theatre that is capable of reproducing 20Hz-20KHz then you may hear a nice even mix. But listen to the same thing on your shitty iPhone speakers that can’t reproduce any low end, and its going to sound much more hollow. That iPhone may have piercing highs and muffled mids too because the absence of certain frequencies can really highlight others. This applies equally to you whether you’re on a mobile device or your TVs built-in speakers There’s also the fact that an audio mix is meant to be heard stationary, from a constant position. Sound level is logarithmic, so moving that iPhone closer and further from you is going to have a significant effect on the quality of sound you hear in that mix. Couple that with acoustics in the room that can significantly affect frequencies and you start to see hw our modern viewing habits are an auditory nightmare. Frankly, it’s a testament to some of these standards that things actually sounds as good as they do across all kinds of different devices. EDIT: so people are now asking about a couple of other things. Let me clarify standards and talk about dynamic range. First, standards don’t mean that explosions are only X decibels louder than dialogue. How all that stuff is in proportion to each other is called a mix. That part is all artistic license in the part of the mixer. What we do is calibrate the mix rooms daily to ensure that everything is being mixed to the same consistent baseline. This ensures that from one scene to the next there is consistency. There are walls other things to consider, like broadcast TV has different standards because there are/were bandwidth limitations in the signals so certain things might need to be compressed differently. And for those that are talking about the commercials being louder than the program, there is legislation governing this (granted, like most legislation its written by people that don’t know what they’re talking about so it sucks). Dynamic range (go google it) is the idea that some sounds are soft and some are loud. There is a range of volumes in real life and the goal of the mixer is to reproduce that closely enough that it sounds convincing. That range in a movie or show is a little more compressed that real life, but you need to keep some spread to convince our brains and not distract the viewer. We could reproduce the entire mix with a range of only 20dB, but that would suck. What most people don’t realize is that sound is subconsciously perceived as good, bad, realistic, fake, etc. A good mix with realistic sounds is something that most people will not notice, but a bad mix will be instantly noticeable and distracting. So why don’t they mix it for computer speakers and iPhones even if it’s intended for Netflix? Because audiophiles like me will still pull it up on my roku with 5.1 sound to watch it properly. Frankly, they do it so people like me will give them academy awards and they can charge more for the next film they work on. If the whisper to explosion ratio is really bug in you that much then a) get your ears checked, or b) get a compressor for your viewing system to compress the dynamic range and make everything the same level. But don’t complain when it sounds bad in a different way.",
"A lot could be happening here. First off, the devices we use today are all connected and often all have SEPARATE volume controls. When you send a low signal to an amp playing it loud or a loud signal to an amp playing soft (dangerous for the speaker), frequencies can get distorted very easily and things sound harsh and unpleasant quickly. Another thing that could be happening is different media itself has different \"rules\" when it comes to audio. Video games, for example, often normalize audio so most things are at the same level. If you pop in a Blu Ray or stream movie off Netflix, audio is mastered to be more \"realistic\"--aka, whispering really IS quiet, and explosions really WILL startle you. Music is typically made as loud as possible these days (google \"loudness wars\") so if you go from music to a movie there will be a huge difference. The thing is, similar things happen with video and images as well, but we don't notice things like blacks being slightly too gray or reds being a little too vibrant as easily as we notice a harsh sound. It all comes down to there simply being too many variables for the way we use audio right now for things to be consistent. I'm an amateur musician/sound designer. (Just Like Ammy 😀)",
"I’m super bummed out by a lot of these responses. I make a living working on sound for films, and while I’m mostly a Dialogue Editor and Foley artist, I have mixed and study under/work with the best guy in my state. Yes, we mix for theaters, and in surround, but that’s because the mix will translate to other devices and stereo a lot easier (in theory, although admittedly it’s...tricky to say the least). We were both trained to mix dialogue FIRST, and base everything else around that. Louds can be loud, and softs can be soft, but what’s being spoken is the most important thing (even whispering). Not everyone follows this rule, and it sucks. As far as blaming the Mixer, especially on anything that was released in theaters first (so anything out of Hollywood), trust me: you absolutely do not get to that level without being a master of your craft. Those people definitely know what they’re doing. But it’s not 100% up to the Mixer. It’s not his/her Film, it’s the Directors. And even big-name Directors are usually at the mercy of the studio paying for the film. I’ve heard of several mixers who had to do things they were absolutely not proud of, but that’s because the person writing the paycheck wanted it differently or thought they knew better. Also, there is, and probably will never be, a universal lossless audio codec, and most of the lossy codecs nowadays tragically alter the mix of a film. Even playing back on an expensive 7.1 home theater system won’t be the original mix, let alone headphones from a phone. We just haven’t figured out how to truly translate from the original mix to smaller and smaller devices. There are many reasons for this all-too-common complaint, and as a professional, please believe there are those of us actively trying to make a difference. TL;DR - Please don’t blame the Mixer. We’re doing our best, and there are a ton of factors that go into this complaint, and yes, we are wildly aware that there is a problem.",
"Dynamic range. You can have all sounds at the same level by crushing dynamic range, but the side effect is that gunshots sound like toy pistols.",
"Because most people who mix *English language* shows and films assume you have a proper audio setup. Guess what, I don't! It annoys me to no end. I prefer to watch in original English than dubbed in my native language of whatever, but at least the *mixing in my language does NOT sound atrocious*, so I think the problem is confined to English-speaking media. My pet peeve is when the characters speak, but the other sounds (or music!) basically roars over them. It's so bad that I occasionally have to download subtitles in English, for a film that's already in English, just to be able to follow what's being ~~said~~ mumbled quietly.",
"In the situation you're describing, 95% of the time it is the fault of whoever mixed the audio. It's their job to make sure the final sound is mastered and leveled correctly to be played back. The best audio system in the world will sound like trash if the input audio source is a 128 kbps MP3 or even a 16 bit FLAC if the mastering sucks. If the bass suddenly spikes up too loud, they likely boosted it more than they should have. Ditto for treble. Google \"loudness wars\" for a taste of what's going on behind the scenes. We can correct this on our end to some extent however, as many systems (computers, receivers, VLC, Spotify) are able to normalize the audio that comes through. For example, my TV has a night mode that normalizes the volume by reducing the difference between the loudest and quietest sounds.",
"It's complicated. NAB has a guide regarding the technicalities of this but, in short, it all comes down to cubic feet of room space. When you mix in a bigger space you have to push more cubic feet of air and the nature of dynamics changes. A lot of films and tv shows are mixed on dub stages that have a cubic air space that's much bigger than a typical home residence. This explains why the dialogue is so low and things get so loud. When you move from a big space to a small space the dynamics are exaggerated. Low volume content becomes too low and loud content gets too loud. Dialogue becomes too dynamic. The reverse is also true. I remember a doc I mixed in a smallish room and it was run at a theatre and it was much more dynamic. They complained it wasn't loud enough in the big room even though they sat in the small room and said it sounded fine. So, mixes in smaller spaces don't translate well to bigger space and mixes that happen in bigger spaces don't translate well to smaller spaces. I actually warned them about this and they didn't listen to me (ironically) when I said the mix wouldn't translate to a larger space. I don't think they wanted to spend the money on renting out a big theatre just for their little doc. I end by saying this: I think there needs to be a technology that allows you to adjust a mix based upon the cubic feet in your space. Basically, it's a smart mix. The stage the show / film is mixed on enters in their cubic feet and optimal listening position and it compares that with your home setup and adjusts for optimal listening.",
"It's called dynamic range, and it is intentional. The best audio systems often have the greatest dynamic range.",
"They do that on purpose, for dynamic sound. It's great if you have a home theater setup but terrible if you live in an apartment or the rest of the house isn't paying full attention to the same program.",
"Because actors and directors have decided that Whisper talking is more intense and recognized that when actors talk in a whisper it forces the listeners to listen more intently and then focus on the show. And then SFX people decided that sounds and explosions sound better really loud. So there is no middle ground.",
"Short answer: dynamic range. Basically the movie was mixed with a theater in mind, meaning a big sound system. With that in mind they can make the whispers quiet and the explosions loud so you have a relative difference thus giving you r loud sounds more impact. A good analogy is a tall mountain/building looks taller when it is the only mountain/building around. So when you go back to pay it on smaller speakers that have quiet mids, you have to turn it up to hear dialogue but then the explosions happen hitting all the frequencies and it sounds way too loud. Would be cool if you could choose a night time or small stereo setting with more compression. Compression is just flattening the soundscape so your whispers and explosions are all the same volume, obviously not to that level but you get my point. Best would be if it could auto detect ur set up and adjust accordingly",
"Personally, I think it's a conspiracy by the audiologist/hearing-aid consortium. :P But seriously, I usually turn on closed captioning and turn down the sound. The closed captioning keeps me informed when people whisper and I don't get my eardrums blown out by sudden trains and gunshots."
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8kgtuz | When Trying to Delete a File, Why Can't Your PC Tell You What Programs It's Open In? | Technology | explainlikeimfive | {
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"Because nobody designed the file management interface to do that. Seriously; it should be dead simple to do. When you attempt to delete a file, the OS checks to see if the locked bit is set. However, the OS also keeps track of what files each open application has file handles for; it just doesn't take the time to walk through that list of open filehandles for each running application to identify the culprit. On OS X, you can do this yourself from the terminal using the command \"lsof\" (LiSt Open Files). Windows and Linux have similar features.",
"Download Lock Hunter for Windows. It adds a right-click context menu item to all files so you can see what process is locking it and then unlock it or kill the offending process."
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8kgzh2 | how are tv shows on cable converted into digital files that are uploaded online? | I am curious as to the technical aspects that are used to convert a TV program that is from a cable box into a digital file like .mkv and .mp4 that is the format I generally find online? | Technology | explainlikeimfive | {
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"Typically by using a capture card ( & playing the entire video from the cable box/etc), but sometimes people are able to get a digital copy from the source (e.g. they work for a content provider & leak the source files)."
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8kh8wz | I understand binary is made up of 1 & 0 numbers but how does it work? | Technology | explainlikeimfive | {
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"Inside a computer, a 1 or a 0 is represented by a voltage. You can think of voltages for electricity like you think of height for water. There are little tiny storage devices (capacitors are very common elements that do this but there are many others such as a magnetic field on a mechanical drive) that store electricity. Going back to the water analog, they would be like water tanks for water. And these \"electricity tanks\" are either full (holding electricity and storing a 1) or empty, (not holding any electricity, storing a 0).",
"Did you learn the 1's, 10's, 100's, etc places in school adding and subtracting? Each column represents a power of 10: 10^0 = 1, 10^1 = 10, etc, and the number in each column represents how many of that power are represented. So, 427 actually means (4 x 10^2) + (2 x 10^1) + (7 x 10^0) Finally, you can never have more than 9 in a column, because that would increase the exponent: 10 x 10^2 = 1 x 10^3. We call this a \"base 10\" number system. Binary is a base 2 number system. So your columns are powers of 2: 2^0 is the \"1's\", 2^1 is the \"2's\", 2^2 is the \"4's\", etc. So, 11001 is (1 x 2^5) + (1 x 2^4) + (0 x 2^3) + (0 x 2^2) + (1 x 2^0) , or 16+8+0+0+1 = 25",
"The wok like numer is work like out base 10 numbers but you only have two numbers 1 and 0 In decimal every new digit position you add on the left side is 10 time lager then the previous position 562 can be looked as 5\\*100+6\\*10+2= 5\\*10\\*10+6\\*10+2 or written in another way and order 2+6\\ *10^1 +5\\ *10^2. So it is the digit times the base to the power of the number of steps to the left from the end 1111 in binary or base 2 soul be the same as if yo conveter to decimal 1+1\\*2 +1\\*2^2+1\\*2^3=1+2+4+8=15 1010 is 1\\*2+2\\*2^3 =10 You can calculate with the like decimal number as but 0+0=0 ,0+1=1, 1+0=1 , 1+1=10 Writing addition by hand in text on a computer is hard but i try this a bit strange syntax. But by hand on paper it is like adding decimal . Decimal (for the syntax): 15+16= 10+10+5+6= //5+6=11=10+1// =10+10+10+1=31 Binary: 101 +11= 100+10+1+1 = //1+1=10 // = 100+10+10= //10+10=100// =100+100=1000 That is 5+3=8 The same math rules apply so you can have any integer base you like 8 is also used in computer but base 16 or hexadecimal are the one that is the common used. You have to add extra digit so A=10, B=11, C=12, D=13, E=14, F=15 2F in hexadecimal is in decimal 2\\*16+15=47",
"Computing is just insanely fast \"morse coding\" using electricity. 1 means electricity exists and 0 means it doesn't exist in a given circuit and at a given moment. Humans have 10 fingers. I believe that is the reason we have numbers 0-9. Now imagine if humans had had only 6 fingers since the dawn of time. We'd be counting numbers as: 1,2,3,4,5,6,10,11,12,13,14,15,16,20... and so on. Now imagine you had 16 fingers. There's your hexadecimal number system, where 10 is A, 11 is B, 12 is C... Now imagine if we had only 1 finger. That is the binary number system."
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8khjk4 | Why do clocks gradually become a minute or two off? | I've noticed this phenomenon whenever I sync my bedside clock with the clock on my phone. My phone's clock is synced to the Internet, but my bedside clock isn't, and over time—about a month or so—my bedside clock will end up a minute or two faster or slower than my phone's clock, even without me touching it. Why is that? | Technology | explainlikeimfive | {
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"Many clocks set their time with an internal vibrating bit of quartz. It's supposed to vibrate a certain number of times per second. But the manufacturers allow a tiny percentage of error in that.",
"Your phone's clock is set using the internet, which gets its time from atomic clocks. Your other clocks use some other form of timekeeping (for example, a quartz crystal oscillator) that is less accurate. Therefore the times will begin to deviate.",
"Some materials have an interesting physical property, when you hook them up to a steady supply of electricity, they cause a bunch of pulses at a specific rate. This is incredibly useful for things like clocks [1]. Quartz crystals are usually used for this because it's common, cheap and works well. The exact rate of pulses depends on a lot of things: - The crystal material (including any impurities or imperfections in how the atoms line up with each other in ideal shapes) - The crystal geometry (how it's cut, including any imperfections in the cut) - The exact voltage of the applied electricity (including variation in the electronics that produce the voltage and any electrical noise from random nearby circuits, power supplies, interference from radio / TV / wifi / microwave ovens, etc.) - The exact temperature It's impossible to control all these variables perfectly, and expensive to control them more precisely (in terms of not only money, but things like size, noise, and power requirements). It's much easier to either connect to an external time source, or require the user to manually update the clock when it starts to get out of sync. These days, most devices that sync time do so via GPS, Internet (NTP) or the cellphone network. You may be interested to know that many countries also have [radio time signals]( URL_0 ) which some devices can use to set themselves. And at one point in time, the folks who run the power plant that provides AC (alternating current) in the power mains went to some trouble to make sure the number of alternations in the AC over long time-frames was exactly on target, so clocks could keep time and not worry about drift if they just count mains pulses. I think that was enough a pain for the power grid operators that they stopped doing that sometime in the last couple decades, though. [1] And also for computers, whose design tends to involve turning various flows of electricity on and off in very precise and complicated sequences."
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8kiwf2 | Why airplanes only record audio during flights and not video? Wouldn’t video be more valuable for the NTSB in case something bad happens? | Technology | explainlikeimfive | {
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"Video recording requires more sophisticated equipment and storage space, and it would have limited field of view, so chances are, it wouldn't see everything that goes on. This made it impractical in the past. As technology advances, having this additional capability seems likely.",
"They don't only record audio. They record countless raw data feeds from sensors all over the aircraft. These feeds plus the audio form a more complete image than any small field of vision of a video could ever hope for.",
"A couple of reasons: 1) cost v usefulness 2) system integrity v usefulness There are two black boxes, not one. The first records all of the button presses, switches, altemeter readings, etc. Which tells us everything the pilots **did** to the plane and what the plane did in response or vice-Versa. The second is the voice recorder which is a physical tape. The advantage of it being an actual, physical tape is that if a bit gets damaged then the rest is still ok. With a hard drive or digital storage facility, if it gets physically damaged then everything is lost. Remember, the only time it is useful is *after* it has been smashed into the ground at e.g. 500mph. Video tape is far more fragile and takes up much more room. A video tape of a 12hr flight would be huge compared to audio only. Ultimately, it’s a question of whether or not the gains to be had are worth the extra investment and risk of corruption. Currently they are not but that doesn’t mean it might not become more viable in the future."
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8kltu7 | Why does the same type of GPU take 8 pins when another one of another brand takes 16 or 18 | Like take the 1070 Gigabyte Turbo. It only takes 8pin but the MSI 1070 gaming takes 16 pins I believe. Why is that? | Technology | explainlikeimfive | {
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"More power hungry fans, rgb, better pcb power delivery for OC, or a combination of any or all 3",
"You're talking about the extra power connections correct? They're likely expecting to draw different amounts of power. I'd suspect the MSI model with 16 pins is overclocked compared to the Gigabyte model Those extra connections provide additional power to the card. The PCI-E slot is rated to provide 75W, a 6 pin auxiliary connector is rated for 75W extra, and an 8 pin provides up to 150 W extra If they're expecting the card to draw significantly less than 225W then an 8 pin and the slot provide enough (150+75 = 225W max), if they overclocked it and think it'll run higher and possibly exceed 300W then they'd put two 8s on it(150 + 150 + 75 = 375W max) sometimes they just put more than needed to ensure they won't have any issues with those connectors getting too hot"
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8kluzh | What physically changes with every iteration of CPUs and GPUs that cause them to be faster than one another? | Technology | explainlikeimfive | {
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"Short answer, sometimes little changes, sometimes a lot. Long answer it depends on a lot of factors, those HW designs have several architects working on several parts, each architect had a big team working on improvements over the previous generation. Generally they iterate over the previous designs by adding or removing features (and bugs) sometimes in order to have a real improvement they have to redesign that part from scratch. Sometimes the changes are global say, when you change the size of the transistors for example doing from 14nm to 10nm in that case that change affects everything, sometimes the changes are better buses or better memory management (generally cache, prediction etc) sometimes even the physical arrangement of certain sections on the chip can improve efficiency. Source: when I was a driver developer I used to work really close with several HW engineers and architects, for me it was important to know how the HW was designed so I could better plan how me and my team should tackle the challenge. Edit: I forgot to mention, within the same generation usually the design shares most of the features but stuff might be removed in order to make the chip cheaper I saw that a lot. An i5 is pretty much an i7 with ht disabled for instance. In the case of graphics chips I assume the difference is type of cache, number of cores and features that get 'fused' (removed logically but not physically)",
"It used to be that improvements came by increasing clock speed. If your clock ticked faster, you could do more work in one second. Then around the early 2000s we started to hit the clock speed limit. Now improvements are usually by adding more logic circuits, and improving the design and speed of them. One obvious change is making everything smaller. The size you see in chip architecture, like \"10 nm\" (nanometers) refers to the approximate smallest size of a single element on the chip that the machines can manufacture. When everything is smaller, it takes less time for signals to travel around the chip. In fact, the speed of light itself is starting to become a limiting factor - it can only move about 10 inches in one nanosecond! New generations also try to cram more logic circuits on a single chip. You see this especially with GPUs. Each core can do math independently of the others, and at the same time. Current GPUs have thousands of cores. Another improvement is to design circuits to do more complex math in hardware, which is faster than having to do it in software. Some new chip architectures introduce new instructions for programmers to use. If previously graphics software had to do some complex calculation a billion times, a new GPU might add that calculation directly into the chip wiring. There are even new chips being designed specifically for cryptocurrency mining. Finally there's always some tweaking that can be done to make everything more efficient, consume less power, dissipate heat more easily, etc.",
"The semi-conductor manufacturing process is pretty much the same in most cases, but has varying yield. The chip is bench marked during manufacture and branded and priced accordingly. i.e. i7 and i3 pass through the same process. The i7 just turned out to be up to standard. i3 not so much so Intel turned a few features on and off, and priced them differently. URL_1 URL_0",
"Within the generation? Typically the difference is components of the chip are duplicated. For the 1080 vs 1050, [look at NVIDIA's specs]( URL_0 ). The cuda cores being 2560 vs 640 is the main driver of performance, a cuda core is a small processor that actually does the work, the higher end has more of them (which makes the higher end chip much larger and drives up the price). They do it the same with other components, there are memory controllers and memory chips, they add more of each to improve performance as well. They do have higher clock rates on the higher end chips, but that's usually not a design thing, but a testing thing. They typically build the same chips, and the ones that can't perform at the higher speeds are just sold as a lower spec chip."
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8klycv | How do Wikipedia pages stay in sync? I was looking at Meghan Markle's, and it said she is married to Harry, sixth in line to the throne. But he's only been sixth for a couple of months. Does someone have to go changing every Wikipedia page he's on from fifth to sixth? | Technology | explainlikeimfive | {
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8kmtou | How did Google manage to get 3d models of every building on Google earth? | Technology | explainlikeimfive | {
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"[Here's a video]( URL_0 ) about the topic, related part starts around the 2-minute mark. They mostly use planes and helicopters to get high res images, to use \"photogrammetry\" to construct the 3d models of buildings.",
"Google used to actually model buildings by hand (or have community members submit them). But with the most recent 3D models you're seeing of whole cities, they're using a technology called photogrammetry. Basically they fly an airplane with carefully-calibrated cameras that take photos from different angles. Then a computer program figures out the 3D shape of things using parallax (basically the same thing your brain does with the two images your two eyes supply).",
"You think that's mind-blowing, i have an HTC Vive Virtual Reality headset and they have a Google Earth VR app and it's probably the closest thing you'll get to a religious experience in electronics. You can fly around the world from outer space to a dirty Philly alleyway.",
"Most of the buildings are modelled from satellite data. Google buys different satellite images from different angles of the city and uses a program to calculate the height of each building. Important buildings such as monuments are manually sculpted in sketchup. Some buildings have food plans in a publicly available database and Google uses this to calculate the shape of the building too.",
"Can confirm, most images are done by plane. Source: knew someone who worked for one of the companies that flew the planes.",
"It's called photogrammetry: [ URL_2 ]( URL_2 ) Basically, you take pictures \\(2D\\) of something from several points \\(in your case, Osaka from a plane flying over a city, not too high\\), and then a software creates a 3D model out of them. See this picture from the wiki article above: [ URL_0 ]( URL_1 By taking photos of the car from above, below, behind, left and right sides... you can create the 3D model.",
"Photogrammetry is really cool. There is an app for hobby drones (DJI phantom) where you can lay out an xyz path for your drone to fly it will take a bunch of images and and the app will generate a 3D point cloud.",
"The footprint is taken from the satellite \\(or top down image\\) or map. The height can be calculated by referencing the building from different vantage points, this can be from multiple plane positions or even the street view images. Another method is to analyse the shadow length against the time of day. Some are produced by hand \\(google used users to contribute to their model collection\\). Some are provided by the building owners, if you want your building to be found, the more information you give google on it the better. Some are taken from public data such as planning documents. IMany new buildings are planned using the principles and technology of \"BIM\", which would submit the model shell to the planning boards.",
"[Here's]( URL_0 ) an article which goes into a good bit of detail about what exactly Google has been doing all these years with Maps, and how that head start puts it ahead of its competitiors. Really interesting read",
"[here’s an in depth blog post]( URL_0 ) how google uses machine learning, image recognition and multiple data sets to extract building shape data."
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8knc6q | How come in most medias Apple products can used but the OS cant be used? | Technology | explainlikeimfive | {
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"What I mean is when I watch a show like *13 Reasons Why* they are shown using iPhones and MacBooks but they dont use any iOS on these phones when they use them"
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8kr5qs | Why do all modern phones have stripes on the bottom? (Picture in text) | [Like this]( URL_0 ) | Technology | explainlikeimfive | {
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"If your talking about the thin lines that run all along the phone, them it's separation for the antennas in the phone. Your phone has different antennas for cellular/LTE connections, Bluetooth, wifi..... Those lines are either where the antennas are run or they separate different metallic parts of the phone that act as antennas.",
"They are the antenna for cellular communication. Metal casing doesn't allow electronic transmission very well, which is why you need glass/wood/leather for wireless charging."
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8kr95f | why sometimes a Browsee doesn't recognize the file size of a download | Why are some downloads marked as 'unknown file size', while others are known beforehand? | Technology | explainlikeimfive | {
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"The download starts with some headers which tell your browser about the file - things like what type of file it is and whether it has been compressed. The headers can include the file size, but they don't have to. The server may not even know the file size when it sends the headers, because it may be generating the file on demand rather than just reading it from disk.",
"When you're downloading a file, the website just gives you multiple blocks of data one after another. At some point it will close the connection which tells your browser that the file is complete. Your browser generally has no idea how large a file will be until it is finished downloading. The website can tell the browser the expected file size at the start of the download, but it isn't required to do so and the information might also be wrong. That's why a download sometimes goes above 100% completion."
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8ks1cb | Why did it take so long for TV's to adopt the 16:9 format? | Technology | explainlikeimfive | {
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"**TLDR: (1) There's no reason to own a 16:9 TV if there is no 16:9 content available to watch on it. (2) Only a small minority actually care about widescreen.** The first 16:9 TVs were made in the early 90s, but very few were sold, because (1) they were incredibly expensive, and (2) there was very little 16:9 content to watch on them. There were a few anamorphic Laserdiscs that were specifically designed to work on 16:9 TVs. However, Laserdiscs were a very niche market to begin with, and anamorphic discs were even rarer because they could not display properly on a 4:3 TV. Meanwhile, 99% of us were watching movies on VHS, which were only capable of displaying a 4:3 image. There were \"widescreen edition\" VHS tapes available, but the image was still 4:3, just letterboxed with black bars at the top and bottom. If you were to play one of these letterboxed tapes on a 16:9 TV, it would look terrible because you would have black bars on all four sides. (It's also worth noting that \"widescreen edition\" tapes appealed only to cinephiles who wanted to watch movies in their original aspect ratio. Joe Public *hated* them, because he wanted the image to fill his TV screen without any black bars. There was therefore only a limited selection of letterboxed movies available, relegated to a special section of the store.) Things started to change once with the advent of DVDs. DVDs differed from previous technology, because the same disc could be displayed in different ways: it could fill up a 16:9 screen at full resolution; it could display a letterboxed picture on a 4:3 screen, or it could display a \"black-bars-free\" 4:3 image to keep Joe Public happy. Suddenly, every movie you bought in the store could be played in 16:9, without having to buy a special \"widescreen\" edition. This increased the desire for 16:9 TVs amongst those who cared about watching movies in the original aspect ratio, therefore gradually making them more affordable. Joe Public, meanwhile, would stay happy with his 4:3 screen. Much like VHS, analogue TV signals could only support a 4:3 picture. It was not until digital broadcasting was rolled out, that a TV signal could be broadcast in 16:9. Much like a DVD player, a digital TV receiver would adapt the image to display properly on whatever shape TV you had. Once digital broadcasting became available, all of our viewing content was now available in a 16:9 format. At this point, TV manufacturers decided that there was no good reason to continue manufacturing 4:3 TVs. Coincidentally, this is about the same time that flat-screen technology was becoming more widespread. Joe Public had spent years not caring about widescreen. But what he did want was a flat screen! And well, it just so happened that they were only being manufactured in 16:9! And that was the final nail in the coffin for 4:3.",
"The 4:3 aspect ratio was the one originally used by movies before they switched to a variety of wider and wider aspect ratios. Switching film projectors to a different aspect ratio was relatively simple, but TVs once a standard had been defined could not as easily be switched to a different format without breaking backwards compatibility and making all older TVs obsolete. The analog tv signal already made as much use of the bandwidth available as it could, there was not really much room in the tv signal that newer tvs could use for wide screen and older ones could ignore. It was only with the advent of digital tv broadcasts that wide-screen broadcasts became possible. Also Cathode ray tube technology, used in TVs before the advent of LCD and LED screens, does not really lend itself to wide screen aspect ratios. Making it display wider pictures would require a much bigger and deeper tube."
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8ks3ir | why are songs that are edited to sound as if they’re ‘playing in another room’ more enjoyable to listen to? | Technology | explainlikeimfive | {
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"I've never seen this before and it just sounds muffled to me. Definitely not as enjoyable as just listening to the original song imo.",
"This effect is running the sound through what we call a low-pass filter. Any sound can be decomposed into many different basic frequencies. A bass sound has a low frequency, a cymbal hit has a lot of higher frequencies to it. Higher frequencies are absorbed by walls, but lower frequencies tend to pass through. That's why things sound muffled: you're keeping (passing) only the lower frequencies. High frequencies sound harsh to the ear, and so getting rid of them makes the sound smoother to listen. Since rhythm and beats are usually on the lower frequencies, those are mostly left untouched. People who enjoy the beat part more than the melody may enjoy it more because this effectively emphasizes the beat."
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8ksw2h | how do silencers on guns work? | Another question i have but isnt really eli5 related, do the silencers in movies sound anything like real ones? | Technology | explainlikeimfive | {
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"The bullet is launched out of the gun by an explosion that superheats the air and produces a loud BAM sound. The gas/air that carries that sound wave doesn't have anywhere to go except out with the bullet. A silencer basically extends the barrel and helps that \"explosion air\" diffuse in other directions so that the resulting explosion from the gunshot is much quieter. Movies and games that have a \"pew pew pew\" sound with the silencer attached are doing it wrong - it really is still an explosive sound, just heavily subdued, like a brick hitting a sandbag or something.",
"They’re a little louder than they are portrayed to be in movies...one thing most people don’t know about suppressors, is they are really uncomfortable to use. When you shoot guns with them , the suppressor causes a lot of gasses/gunpowder to travel back through the firearms receiver and sprays right into your face...every time I’ve shot guns with suppressors, after about 30 shots my eyes would be stinging, and watering , and I could barely see.",
"5 year olds love balloons. Firing a gun without a suppressor is like popping a balloon. If you were to untie the balloon and let the air out slowly, yes you might get that hilarious fart sound, but it's much quieter. The hot gas in the barrel expels through the suppressor, slowing it down as it reaches the outside air. When the bullet leaves the barrel, the hot gas escapes at a higher pressure than outside air pressure. (Also when the bullet leaves the barrel, it creates that \"snap, crackle, pop\". So when you use a suppressor, you want to use sub-sonic ammunition.) Other ways and ages to see it are opening a can of soda quickly vs slowly. (You know when you sneak one from the kitchen at 3am and you don't want your parents hearing, so you muffle the hssss sound and forget the can still makes that \"crack\" sound when it opens. Sub-sonic ammunition gets rid of that.) Also for adults, opening a champagne bottle by popping it open or slowly releasing the built up carbonation inside. Same concept all around."
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8l1k2k | What are Events per Second on a CPU and what is their relationship with OS speed (in Mb/s)? | Technology | explainlikeimfive | {
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"What definition of the speed of a OS in Mb/s have you found? \"Events per Second\" is what is say. How man events happen each second or what is the max numer of events that can be handled each second. What a event is depend on the context. So you are likely asking a proper question from a specific field. But by leaving out all information of the context the question is quite meaningless because they are no terms with a single usage. It is a bit like asking the general question \"How long is a rope?\""
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8l1sl8 | Is it harmful to keep my laptop plugged in? | Technology | explainlikeimfive | {
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"No, just the opposite. It saves wear and tear on the battery. Don't worry about overcharging; the charging logic in your laptop knows how to take care of the battery properly."
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8l25o1 | Why don’t airplane oxygen masks inflate? | Technology | explainlikeimfive | {
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"They will inflate only if the pressure of the oxygen line flowing to the mask is greater than the cabin air pressure. This will happen if there if there is a decompression at cruising altitude. At lower altitudes, the outside air pressure is higher, and the bag on the mask won't inflate. In the event of a loss in cabin pressure, there probably isn't time for a physics lesson and a math problem, so the flight attendants tell you that the mask may not inflate, so that you won't think that yours is broken."
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8l305c | How are weather balloons deployed so that they do not pose a risk to commercial air traffic? | Given the fact that weather balloons are frequently deployed to obtain critical measurements for making more accurate weather forecasts, how do pertinent governmental agencies ensure that they do not pose a risk to commercial air traffic where there is a likelihood that a collision/impact with these balloons may take place? | Technology | explainlikeimfive | {
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"There is a suggestion that the local air traffic controllers be notified of the intended launch of a high altitude balloon so its presence is known, but the more relevant regulations regard the content of the payload. There are limits on the total weight and density of the payload, as well as the separation force of the payload from the balloon. The intent of those regulations is that on the exceedingly low chance that such a balloon would be struck by an aircraft it wouldn't cause any significant damage. Remember that the sky is very large and there aren't really that many aircraft in flight. Hitting a weather balloon by accident is just an incredibly remote chance; far more likely is hitting a bird of which there are quite a few. If the payload is roughly the size and weight of a crow then a commercial jet engine would deal with it in much the same way it would the crow, namely going \"Nom nom nom!\" and not really caring.",
"The balloons go much higher than aircraft. Still, there is a risk when the balloon is on its way up or down, even though it's a very small risk. Generally, a NOTAM (Notice to Airmen) is issued for the launch. Most weather balloons are launched on a regular schedule, though some high-risk days may necessitate additional launches.",
"A typical airliner might cruise at an altitude of ~30,000 ft. Weather balloons will rise to an altitude of ~50,000 ft up to ~120,000 ft. Whenever a launch takes place the FAA (assuming we're talking about the US) would be notified and airspace can be restricted to avoid collision. They're really quite far apart."
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8l363l | How do live sports channels always catch the right camera to broadcast from several camera angles? | I primarily watch Cricket, or sometimes soccer, and the video always lands on the right cameraman and camera angle without making a mistake, irrespective of how fast the ball is. How is it so? | Technology | explainlikeimfive | {
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"Multiple cameras and the direction team watches all at the same time. If another camera has a better view they change to that camera. I'd say they are experienced enough to predict which to switch to.",
"They have multiple cameras covering the game from every angle. Somewhere (stereotypically in a truck) there's a [room full of television sets]( URL_0 ) where a group of people who can see the output of *all* the cameras and choose which ones to show. The people who make those choices' day job is to watch a sport and choose angles to show, so they've almost certainly seen a play similar to any given play from every possible angle.",
"Here are some behind the scenes footage of what goes on in a control room. Neil Patrick Harris - 2013 - Tony Awards Opening - HD URL_0 The 67th Annual Tony Awards 2013 Behind the Scenes - Director on FIRE! URL_1 Inside the Super Bowl 50 Halftime Show Control Room URL_2",
"These people are professionals whose entire job is to get stuff like this right. Practice, skill, and experience",
"I directed live multicamera stuff for a while (not sports). I could see all camera feeds simultaneously in the control room. With practice you learn to anticipate actions and you can assign cameras accordingly. Mine had manual movement control and preset shot positions and so you learn the space. Early on I stressed about it, then learned to adapt when I made a mistake, so if I chose the wrong shot I would do a pan to bring the right shot in, for instance. I sometimes see moves in live events and wonder if they are smoothly handling a miscall. Also, some events are not actually live, but have a delay. I never had a delay, so I cannot speak to the utility of such. If you want to learn to handle stress, go work in live TV. you learn quickly or you quit.",
"They’re really good at what they do. It’s also set up precisely to capture those moments. There are fixed cameras placed all around the stadium. Each camera man will only be able to cover a specific sector of the ballpark or stadium, so they generally tend to focus on a few specific types of shots or angles. Most of the time you aren’t watching closeups of players, rather wide shots. Camera guys don’t track the ball so much, as they try to frame the ball. In baseball, and by obvious extension cricket, the camera used to cover the action is a wide shot that pans slowly to frame the ball. That is, just to get it in the shot. Most of those other cameramen are doing this at the same time. What you get is the action from every possible angle. You don’t see a lot of full shots, covering an entire player, or close ups unless there’s a lull in action or you’re watching baseball. Take hockey for instance. There’s usually three cameras grabbing wide shots that are used when they’re in play. Right now you can only see a summary of the action. When play stops, and the color commentator kicks in, the feed goes to full shots to explain the action. Now you can get the detail. Usually in a truck, but more generally some sort of room with dozens of TV’s, there’s a dude whose job it is to monitor all possible angles at once and then selecting them. The act of taking all of the feeds and turning them into one is called mixing. In baseball, it’s fairly simple to mix an at bat. You have cameras getting a full shot of the batter and pitcher, a shot from behind the batter looking towards home plate, and a wide angle master from the top of the diamond. The other cameras are focusing on individual players, dugouts, fans, etc. but hose will all switch to wide shots once the ball is put in play. The director will look at all possible angles and select a feed to broadcast. He also listens to the broadcast, so when the announcers talk about a specific play, he can reference it and mix it in. They’ve got all the plays and angles stored and catalogued for easy access throughout the game. It’s a whole thing. This doesn’t even include the live editors, graphics artists, researchers, and producers needed to make them nice and fancy. Tl;dr Multiple cameramen use fixed angles and wide shots to frame the action. Someone chooses from all of those the best one. How do they know what looks good? Experience.",
"Most 'live' events are on a brief delay. Someone is monitoring all of the various feeds and has a few seconds to direct which feed is televised."
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8l666g | What happens when game servers are under maintenance and why is it needed? | Technology | explainlikeimfive | {
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"A server is just a computer. Sometimes computers need to be updated, or restarted or just generally other things that are not conducive to them running your games 24/7. If there is something significant that needs to be done that will affect all or most of those computers, sometimes it it just easiest to take them all offline at the same time during a period of low traffic, make the update and then put them back online."
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8l8i1w | why can taking pictures of certain things cause it damage? | Technology | explainlikeimfive | {
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"Usually it's flash photography that is the problem. The intense light can damage certain items."
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8l9nhg | in the show Silicon Valley on HBO they create a decentralized internet. What is that and in reality how would it work? | Technology | explainlikeimfive | {
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"In a way it's already happened with the likes of torrents and blockchain for example. It's the concept of data and routing being hosted by individual nodes opposed to sitting on a single server or server farm.",
"Alright, you remember in class you have a room full of students, a teacher who's teaching class, and communication all has to be done through notes while the teacher's back is turned? Remember that? Well the guys on the right side of the classroom have a system. So you fold up your note, write the name for the person who should receive it, and the Sampson triplets come up with a very clever stretching routine that can get a note to anyone within reach. They know everybody within reach, and the Sampson triplets can get a message to everyone they reach. Pass it to a Sampson, they take care of the rest. Super simple **centralized system**. super simple... but its got limitations. Their coverage sucks, not even half the classroom is covered and the Sampsons will not work with anyone besides Sampsons, or the recipient. If one of the Sampsons are out sick, the whole system can fall apart. Also one of the Sampsons is kinda a snoop who loves to gossip. So a decentralized system tries to cut out the Sampsons. If we can get the whole class to agree that, hey, pass notes when received as quickly as you can, we have a decentralized system. This... is akin to herding cats. Not all students know each other. You can argue all day that Lewis should know exactly who Samantha is, *they sit next to each other all day* but if he doesn't know who it is he passes it forward, and hopefully the next guy knows. Thomas is a black hole, he sends nothing. *ungrateful jerk passes notes like no tomorrow though*. Privacy is simply not enforceable, you can pass it to someone who won't peek at the note, but you can't guarantee someone down the line is going to pass it to Jesse who is going to gossip about it to high heaven come lunchtime. So now this has to be in code that only the recipient and author understand. The hoops are ridiculous, but it has a lot of perks. As long as the room is still half full, communication will still cross the classroom. (the entire classroom) Privacy is *engraved* into every note by necessity, so its more secure. Instead of the Sampsons choosing what the most efficient (for them) route is, everybody picks the easiest route because they don't want to be bothered for longer than necessary.",
"Are you sure they say decentralized internet, not decentralized network? Because the internet already is very much decentralized.",
"It's essentially an internet powered by many individuals' personal computers, rather than computers in a server farm all owned by a corporation."
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8lbnv1 | Using multiple TV screens to display a single image. | I'm not exactly tech-illiterate, but these have baffled me for as long as I've been seeing them. For example, 9 TVs set up in a 3x3 grid, working together to display one large image. Why aren't they all just displaying the same image? How do they know to display only one part of the image? How do they know which part to display? Would it know if one TV got swapped with another? Is special hardware/software required to do this? I'm totally clueless on this ability. | Technology | explainlikeimfive | {
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"Source: ~8 years doing various digital signage stuff, including video walls (although not my primary focus) > For example, 9 TVs set up in a 3x3 grid, working together to display one large image. In this case they wouldn't be TVs so much as monitors, typically purpose-built for video walls. > Why aren't they all just displaying the same image? How do they know to display only one part of the image? How do they know which part to display? Would it know if one TV got swapped with another? Is special hardware/software required to do this? There's more or less three ways to do this. 1. You could have a computer with a separate video output for each screen, and set up essentially an extended desktop between those displays. To make things simple, let's say there's only 4 monitors at 1920x1080 (1080p) each - using the graphics drivers on the computer, those 4 separate monitors are essentially treated as one big 3840x2160 (4k) image. The computer, and the person setting this up would select which screen represents which portion of the image. 2. You could have an external device (video wall controller) meant to take that 4k signal from a computer (only a single input) and split it into 4 separate 1920x1080 images. Configuration would be similar to the above. 3. Pretty much every monitor designed for video walls has the built-in ability to act as a video wall controller. The screens themselves can only display 1920x1080, however they will accept a 4k input resolution from the computer and have both video inputs and OUTPUTS as well (typically DisplayPort). You run a single video cable from the computer (typically DisplayPort) to the first monitor, then from the first monitor to the second monitor, the second monitor to the third monitor, and then the third monitor to the fourth monitor. Then configure each monitor with the position - essentially, which portion of the screen would be displayed. tl;dr - Either a computer's graphic drivers or a device/screen specifically built with video walls in mind treats all screens as part of a larger whole image."
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8lbnzj | Why do external batteries indicate they are fully charged but seem to continue charging when unplugged and replugged right away? | As the title says, after replugging a supposedly fully charged external battery, it continues charging for a bit longer. I bought some bluetooth earphones and the reliability of them aside, I want to maximise the battery life but I'm getting this issue. After complaining, my sister told me her power bank does the same thing. Why is this? Am I doing more damage by plugging it back in? What should I do? | Technology | explainlikeimfive | {
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"As batteries get closer to full charge, they have a mechanism bullt in that will lower the amount of current they are taking in. Its not unusual to have a device plugged in and for the battery to lose 5-10% energy, and then go back up to full. Modern devices are designed this way to not overcharge the batteries, like old NIMH/NI-CAD batteries use to do. Hope this helps!"
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8ldyb9 | How do touch screens work? How does my phone know to respond to the touch of my finger but not to objects, such as the end of a pen? | Technology | explainlikeimfive | {
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"Depends what type of touch screen. Some, mostly older ones have pressure sensors, allowing both fingers and pens to work. Others go by electrical conductivity. So it will register your finger but not a random pen. But specially made stylus will work because it has the correct conductivity"
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8linff | Why do video games rely on mega high resolution textures to appear more realistic, when a DVD movie can look far more realistic with a resolution of only 720x480? | Technology | explainlikeimfive | {
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"**Professional video game environment artist here** 1.) Movies are recorded from a fixed camera angle for each shot. This means that 4000 pixels on screen are always 4000 pixels, regardless of how many objects you have in a shot or how close up you get to them. 2.) Video games are interactive 3d worlds that you can move 'through'. This means game designers need to find a way to make every object that you can conceivably get up close to, from the gun in your hand all the way to the tree on top of that far off mountain, look good up close. To exacerbate things further, the objects are 3d, which means that every surface needs to be covered with pixels even if you can't currently see it, because you 'might'. *There are things that can be done to help this, like 'streaming' textures in and out of 'memory' when you don't see them, but as a general rule, unless there's a load screen, everything you can see in the world that you can reach must have an ultra HD texture in case you get right up close to it. **Second edit: A lot of ppl have been asking about how I got into the industry or got this particular job, and even suggested I do an ama so I think that's what I'll do. That said, I'll give a brief summary here: 1. To be a game artist or 3d artist in general it helps 'a lot' to have a background in traditional art (drawing and painting mostly) I got a 4 year degree in Illustration myself, but at least some training in the fundamentals is needed. 2. Then you'll want to learn the tools and techniques specific to content creation for current games. This would include a suite of digital sculpting, modeling, and texturing tools, as well as a game 'engine' to bring all your content together. ZBrush, 3dsMax or Maya, Photoshop, and Substance Suite are the current standard, and either Unreal or Unity for your engine. I took a post grad in game art which can be helpful for those who learn better from a guided structure, but not mandatory as YouTube is full of good educational content, and there are numerous excellent online forums and programs taught by pros to choose from (Art Station is a must). 3. Work work work on your portfolio. Look at the pros and see where the bar's set, then aim for that. Don't work in a bubble! Developing a critical eye for your own work is key, but in order to do that you need feedback from those with a keener eye than you, so post you work online and ask for critiques. The importance of this can't be over stated. 4. Apply EVERYWHERE at first (Only for entry level jobs of course). We all have our dream companies and games, but we all gotta start somewhere, so don't be afraid to aim high but don't be too proud to aim low either. Getting your first job and getting your foot in the door is far more important, as it means you will be getting paid to gain valuable experience in the field. Think of it as the first step of your new career that will inevitably wind you up at Naughty Dog or Sony! Ok, that's it for now. Hope that satisfies!**",
"because texture in a game are applied to surfaces that can be viewed from as close by as the player wants. If you have a rock with a 64x64 texture, that looks great if the player is far away enough to make the rock only take up 48x48 pixels on screen. But if the player walks up to said rock and looks closely at it, that rock might be filling the entire screen. Then a 1920x1080 screen is being filled by a 64x64 texture. That doesn't look very good. So to conclude - it's because in a game the player has the freedom to look around and zoom in. Edit: **Professional video game programmer here** ;)",
"Because real life is rendered in infinity x infinity, and then downscaled to 720x480. It's the same reason that supersampling on the ps4 pro typically looks better than just rendering in 1080p. (For those that don't know, supersampling renders a scene in 4K and then downscales for a 1080p display. Results in a much better image and better draw distance than just rendering in 1080p)",
"Since DVDs are either recorded or animated in advance, that can have more realistic shading and lighting, which even the top games and PC's still can't do.",
"You are correlating two different things. Textures are not high in resolution for a realistic effect, though that helps. Cartoon games can also have high rez textures. Games try to please users with crisp and detailed worlds and characters so this means that textures need to be filled with these details. A movie is realistic because of the art direction to put it this way. Look at the Hobbit movies. People say the CG is bad. It's actually not, however it's the cartoon art direction that is misleading them. The color palette and overall bloom makes everything look for kids and slightly off. The Lord of the Rings is gritty and has dark tones and this we usually correlate with realism. Electronic Arts has some realistic games out of there and it's because of the art direction and not the resolution. It's in the chosen lighting and mood.",
"You're comparing two different things. Texture resolutions can be really high while the actual screen resolution is low, and vice versa. Real life has extremely \"high resolution\" textures, the video is just a lower resolution.",
"Let's be clear. \"High resolution textures\" are pictures (to put it simply) games cover in-game objects with to give detail - e.g. a wood texture that you apply to items that are suppose to be wood. Movies use \"high resolution textures\" too ... namely real life - e.g. a wooden spoon ... looks like wood, duh. Secondly, when you say DVD has a resolution of 720x480, you are talking about display resolution - i.e. the number of pixels making up the image displayed on your TV. Videos games can also run at 720x480 and they did back with the Playstation 3 and Xbox 360. Blu-rays typically deliver 1920x1080 as do newer consoles like the Playstation 4 (most of the time anyway, sometimes they drop to 1600x900).",
"The resolution you're talking about in the case of movie \\(720x480\\) is the final resolution. This is equivalent to your screen resolution if you have your game running full screen. Textures are the surfaces of in game objects. If you compare this to real world, you can move the camera so close to the wall that you only see cracks in the paint, but you still see those cracks very detailed, the \"real world texture\" has unlimited resolution. In game, when you put a texture on a wall, and then zoom in to the wall you'll reach a point where the texture is zoomed in so much that it covers your whole screen. Lets say your resolution is 100x100 and the texture is also 100x100 pixels, if you keep on zooming in you will reach a point where you only see 10x10 pixels from the wall texture stretched over 100x100 screen. To avoid this the textures are super big so that even if you zoom in real close you wont encounter pixelization. So, to sum up: > Why do video games rely on mega high resolution textures to appear more realistic, when a DVD movie can look far more realistic with a resolution of only 720x480? The final resolution of the movie might be limited but the resolution of each surface texture in that movie is infinite. Games try to simulate that. Another reason is that simply increasing texture size is a very easy thing to do, while improving things like lighting and physics is often hard.",
"That's a good question and I think the answer taps into two things: the uncanny valley and how we perceive film. The uncanny valley effect is that when we have very simple images meant to represent much more complex ones our brains tend to go along with it. Draw three circles on top of each other, each one a little smaller as you go up, now put a line out of the sides of the middle circle and three dots in the middle of the top one and I can go along with it being a snowman. An artist can draw more detail on it and we can enjoy it even more as a snowman...BUT, if you go super high resolution and try to animate it and make it look EXACTLY like an actual snowman in real life then our brains start to notice the imperfections. It's hard for an artist to replicate the real world perfectly in digital form, especially with things like human faces, which we are highly attuned to. We notice tiny mistakes and it bothers us. The uncanny valley is the notion that on either end of the spectrum (very abstract and simple to perfectly real) we believe, but in the middle our belief sags. One of the better known examples of this is an animated film called The Polar Express, which creeped some people out because they attempted to depict human faces in a realistic way...but it was slightly off. All the mega high resolution in the world isn't going to help, in fact it can make it worse, if the details look wrong on a human face. But I think there is another issue at play here and it's a subtle one. We have watched and loved films for decades (almost a century) at low resolution (that is, a resolution well below what our own eyes can perceive in the real world). Film is a series of photographs projected 24 times a second, it is not nearly as precise as our own vision. Our brains have to fill in the gaps. Film is more impressionistic and flowing. Though, I would argue that our eyes and brains have become more accustomed to higher resolution film and video over time, especially in the last 30 years, but it's a gradual process, it hasn't happened all at once. If the resolution of a TV show or movie is too far ahead of what we expect as a culture we tend to think it looks \"fake\" or like news footage. The most common example for this is The Hobbit, where Peter Jackson, the director, shot the film at 48 frames per second and some audience members felt it made the film look not like a film but like actors walking around on a film set. It was too much information and we lost some of that impressionistic quality of film that makes us drop into it and believe we are watching actual images of hobbits running around in an adventure. It's similar to the uncanny valley concept in animation. However, my guess is that the resolution and the frame rate may continue to march forward, it just has to do so over time. So, going back to your original question: many video games are pushing the resolution and detail envelope, sometimes successfully, sometimes not. Video games are trying to push past the uncanny valley, to eliminate those tiny mistakes that stop us from believing, and bring us into a shockingly believable world that is simulated, but appears real. When games like Half-Life 2 do this well (for the time), it's considered a breakthrough. When a game like Mass Effect: Andromeda fails at making humans look human, people get VERY upset. I think video games will continue to push in this direction and make mistakes and breakthroughs as they go. There is enormous expertise in that industry and it gets better every year, BUT it's hard to capture the real world in all it's detail in every possible way. We still have simple things like \"clipping\" where objects intersect with each other and one is clipped off and it breaks the illusion and video games are an illusion. We also have tons of pixel art games with very simple graphics and we have games with abstract graphics and everything else. I'd argue that gameplay is the deciding factor in whether a game works or not, and most places along the graphics quality/resolution spectrum can work when it comes to the look, except that spot close-to-perfection-but-not-quite where there will always be an uncanny valley. Now to finish this long answer, my apologies for the length, but your question has many parts to it (in fact, I've only scratched the surface). You said that a DVD movie at 720x480 can look far more realistic than video games. The biggest advantage that the movie has is that it is shot in the real world, so the way light plays across surfaces, the way human actors move, the way water splashes, etc. is going to be close to real life (assuming good actors and a DP who uses realistic lighting). A person making a film gets to start with gravity, laws of motion and everything else that actually is in the real world and then capture it on exposed film. That's much easier than trying to programmatically recreate it, because being the least little bit off will trigger our human eyes and minds to reject it. TL;DR: Resolution will continue to march forward for both movies and games, but whether we believe what we are seeing or not is more dependent on the subtleties of the image and how it was created than just on resolution. In fact, going higher resolution or giving the viewer/player more information sometimes makes us believe it less.",
"Video games never relied on mega high resolution to look \"realistic\". The polygon count, texture and lighting quality all together is what is one of the few deciding factors in realism. All resolution does is make the picture sharper and brings out the colors/lightning etc better...just like with movies.",
"The CGI in the last star wars took easily 10 minutes per frame with full raytracing etc at high resolution. Imagine playing a game at 0.016FPS.",
"Because resolution is only one part of the picture. I'm assuming you're talking about real life not pre rendered animated movies. Lighting, not having to deal with polys, not having limited facial animation ect makes a massive difference. CGI is basically the same as a game, expect they take much longer to render a single frame so it can look closer to real life. Where as a game has to render at least 30fps in real time.",
"many comments about textures on things... but that is not the same thing as the overall resolution... playing super mario bros in 4k wont make it look realistic. playing some ultrarealistic game in 1080p wont make it look bad \\(in fact, played on a 22\" screen, you might be hard pressed to notice 4k vs 1080p\\). Resolution does not define realism. Though it can affect pixel density, which is just as true for a movie if you watch it on a large enough screen for those that are of an age to remember older rear projection tv sets.",
"Do you really mean texture resolution (such as how many pixels go into the image representing for the side of a house or the hood of a car) or the overall resolution of the screen in a video game (what you could actually compare to the DVD video resolution)?",
"It's all about rendering. When a movie is finished if it is completely rendered (basically turned into one long scene). This can be done because the viewer cannot change its course. Unlike a video game. Video games basically render while you are playing, because the game does now know exactly how or where you will be moving to. It cannot be as rendered as a movie. Think of a game as continually refreshing while you play."
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8ljjq1 | Why does different USB cables, connected to the same power source, charge my phone faster or slower? | Is it the difference in lenght or structure? What decides how energy is distributed and therefore how fast my phone is being charged? What's the difference between USB cables? | Technology | explainlikeimfive | {
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"The resistance of the cable affects how fast electricity flows through it. Longer cables, and cables with thinner wires have higher resistance. [Here's an article that goes really in depth on the subject.]( URL_1 ) In a lot of ways, [electricity moves like water]( URL_0 ). In this case, it's like hooking up a hose. If you use a longer or thinner hose than usual, you get less water out the other end. Less water can fit through a thin hose at a time; and it takes more energy to move water through a long hose because the same pressure has to move more water.",
"Something not mentioned in the other answers, some cheap and crappy \"usb charging cables\" only have 2 conductors, so the data lines are unconnected, and those data lines can be important in negotiating charge current. That means the phone is unable to request a faster charge and higher charge voltage (eg with Quickcharge), and so the charge rate is limited to 5v500mA. Cheap USB cables are a false economy, as you may also find less conductor in the cheaper ones, and so that adds resistance to the circuit further slowing charge."
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8ljkwz | What makes one browser faster than another? | Technology | explainlikeimfive | {
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"It's mostly due to the design/architecture. Just because two browsers display the same site the same way doesn't mean they work the same. It's like with cars. What makes one car faster than the other? They use different engines, they're designed differently, have less weight, different electronics. Even the engine itself differs, one might use a regular car engine, whilst another one might use a Wankel engine. So there's a lot of differences between browsers under the hood. Furthermore a browser doesn't work on its own, it's part of an operating system and intersects with it on multiple accounts as it deals with all the different protocols and plugins in the internet. And then there's a lot of things a browser does that doesn't really have much to do with displaying a page at all. Like logging telemetry. Analysing the website and optimising it for future visits and so on. Depending on how well this is all executed one browser might be faster than another.",
"Some browsers will anticipate what websites you visit (because you visit them a lot), and can pre-load data from them into memory before you go there. This makes certain sites load faster, but it's using up resources on your system to do this (disk cache which is no big deal, or RAM which can be a big deal). And then there's old Internet Explorer which doesn't support several website design formats, so it loads up other things and then eventually finishes. The replacement for IE (MS Edge) is more like the other browsers."
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8lk7ic | Why can movies run at 24 frames per second and look relatively smooth, but if video games run at 24 FPS they seem very choppy? | Technology | explainlikeimfive | {
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"When a real camera capture a frame, it capture ~~1/24th~~ 1/48th of a second worth of information (see below). Moving objects will appear blurry, so a single frame will still give a some sense of movement. Video games don't do that. They simulate the world frame per frame. The world doesn't exists in between frames, there is no real movement: objects are basically teleported during the simulation. This means that when the game renders a frame it can only display the world as it is at this exact point in time, all information about movement is lost, it thus need to display at a higher framerate to appear as smooth as a real camera. [edit] Motion blur tries to circumvent this (by computing the difference between the current and last state). While it helps a bit, it is an approximation (like anything else in real-time CG) and isn't as good as true, physically correct, motion blur."
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8lmh4b | How can a video that was edited to become a shorter length be so much larger in size/MB? | I have 2 versions of a video. One is a completely unedited gaming video and the other is one that was clipped a little bit to shorten the length of the video along with a few cross\-fade transitions and nothing more. The original one is 658 MB, the edited, shorter one is 1.33 GB. How is this possible? | Technology | explainlikeimfive | {
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"The issue is related to file format/encoding, most likely. Some sources like video games, Youtube and phone cameras compress the frames using very space\\-saving algorithms. This means using parts of one frame \\(the keyframe\\) of video for the next and so on. It's called \"long\\-GOP\" compression. This makes it hard to edit since all the frames are connected. In order to edit this video you need all the frames to stand alone, so you convert the clip into a new format where each frame is separate. With each frame being self\\-contained a lot of data has to be repeated for each frame, so the edited file will be much larger in file size because of all that redundant data, even if the duration is shorter. When you are done editing it may be worth it to export back to a long\\-GOP format to get the size under control. For long clips this can take a while, especially if you want high quality.",
"When you exported the edited version, you changed the compression settings compared to what they were set to by your game-recording software, resulting in a less compressed video. For a 1080p video, try exporting h264, 8000kbps VBR."
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8lqa09 | How building access cards work? | Technology | explainlikeimfive | {
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"Typically they contain a unique ID which is transmitted by short-range radio (RFID) and the reader then sends it to a computer to ask \"am I allowed to open this lock for this ID number?\"",
"This is actually what I do for my career! I’m a Technical Support Specialist for Access Control and CCTV Software. So like said above, the access cards, like HID Prox Cards, give off a frequency which transmits the cards “number” to the reader. The reader is wired (some are wireless) to an access control panel, which is wired via Ethernet to a server. The server contains a database with all the personnel records in it, which usually include, Name, Card Number, and the level of access for that card. The card data itself is binary, and there are different Formats of cards: 26 Bit Weigand, 37 Bit, 35 Bit Corporate 1000, etc. To get the cards and readers to work properly, I get to decode the binary data to see where the Card Number is located in the binary string. The server is loaded with Access Control Software, where you layout the system; where each input (Motion sensor/Request to Exit and DSM’s), output (Electronic locks and Magnetic Locks), and Reader, is wired to the input board(s). In the programming, I tell (select) which Format of cards are going to be used (26 Bit, 37 Bit, etc). Then for that format, I program where, in the binary string, the card number starts, and for how long the card number string is. Once that is set, I save it in the software. Now, when a person that has a valid card, “swipes” their card at a reader, the card sends the binary data to the reader, the reader sends the info to the board, the board sends it to the server where it checks the binary number against what is programmed (the Format/length of that binary string, say 26 bits [26 1’s and 0’s]). This check by the server looks at the digits that I set to start the Card Number and for the length I set it. Converts the binary to a “regular” number, compares/finds that number in the database (usually SQL) and provides access if its a valid number AND clearance."
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8lu3g2 | How do LED lights work and how are they different from fluorescent and incandescent lights? | Asking for a project | Technology | explainlikeimfive | {
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"Incandescent lights work by heating up a strip of metal until it's hot enough to glow. This uses a lot of electricity and produces a lot of heat, both of which are bad things. Fluorescent lights work by adding energy to mercury gas. The mercury stays high-energy for a little bit, then loses that energy in the form of invisible ultraviolet light. This light, in turn, hits a special coating inside the lightbulb which glows under UV light (much like your teeth glow under a blacklight). This is more efficient than incandescence, but still inefficient since there are so many steps to the process. It is not heat-based, so that is an advantage over incandescent lightbulbs. It requires mercury, which is toxic. Finally, it is not a steady process, but a series of very fast zaps of electricity, which produces a flicker (but the flicker is so fast that the human eye can't normally detect it). LEDs basically work the same as fluorescent lights, but cut out some steps. Instead, they directly send energy to a substance which produces visible light, instead of UV light like mercury does. With fewer steps involved, this is much more efficient, and can be kept \"on\" steadily instead of flickering like a fluorescent bulb."
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8luwxq | What's the difference between normal gas and diesel? | Technology | explainlikeimfive | {
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"Ahoy, matey! Yer not alone in askin', and kind strangers have explained: 1. [What's the difference between diesel, premium gas & regular gas? ]( URL_1 ) ^(_2 comments_) 1. [Whats the difference between diesel and unleaded gas/petrol? ]( URL_5 ) ^(_4 comments_) 1. [ELI5: The difference between gas and diesel, and why certain cars use one and not the other ]( URL_3 ) ^(_91 comments_) 1. [ELI5: What is the difference between petrol and diesel? ]( URL_7 ) ^(_13 comments_) 1. [ELI5: What's the difference between a petrol and diesel engine? How do they work and why does putting petrol in a diesel car ruin the engine and visa versa? ]( URL_2 ) ^(_6 comments_) 1. [ELI5: what/why is the difference between gas engine and diesel? pros and cons for both ]( URL_6 ) ^(_10 comments_) 1. [Please ELI5 what's the difference between diesel and regular unleaded gasoline? ]( URL_0 ) ^(_4 comments_) 1. [ELI5: What's the difference between the different varieties of gasoline, why do they exist, and who even buys anything other than regular and diesel? ]( URL_4 ) ^(_13 comments_)",
"From what I understand, It's the way that the engines are designed to combust. Basically, they have to ignite the fuel in the right place in the right way, and different fuels' chemical makeup affects that."
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"https://www.reddit.com/r/explainlikeimfive/comments/1xgbf0/eli5_whats_the_difference_between_a_petrol_and/",
"https://www.reddit.com/r/explainlikeimfive/comments/52s1uz/eli5_the_difference_between_gas_and_diesel_and/",
"https://www.reddit.com/r/explainlikeimfive/comments/6mwj5e/eli5_whats_the_difference_between_the_different/",
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8lv0x1 | Why and how is Microsoft Excel so versatile and powerful? How is it that spreadsheet software can be used as a crude game engine? | Technology | explainlikeimfive | {
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"It does a lot of the basic things you'd want from a regular programming language. Basically, take data from one or more locations (cells), apply math or logic to them, and output a result elsewhere. It handles a lot of details that programmers would otherwise need to worry about, like where values are stored in the computer's memory. It can provide graphical output functions like coloring cells based on what's stored there without the programmer seeing much more complexity than using it for regular math. And Excel can do fairly complex math and logic functions without the programmer needing to worry about *exactly* how many steps are involved, or setting memory or variables for use during the process. So... it's versatile. People may argue about how \"powerful\" it is, it's not hugely efficient with computer resources or fast when doing complex tasks.",
"In computer science, there is something known as Church's Thesis, which states that once a computer/programming language reaches a certain point of complexity, barring performance and resource considerations, they are all equally capable. You can play games on Excel, and you can render video on an HP 12c. Note this is not unique to Excel. People have build functioning computers in Minecraft, and the humble web browser that was designed to display text and gifs now hosts the equivalent of operating systems.",
"Excel isn't just a spreadsheet; it contains multiple scripting engines, can handle OLE and COM objects, has a graphics compositing layer and a really good compute engine. So basically, Excel can do everything a web browser can do, as well as some extra optimized stuff a web browser can't do. Of course, this is true for any OLE-compatible program, so you could easily insert MS Word or PowerPoint instead of Excel and the situation would be the same. Yes, you can now port any HTML5/JS games to PowerPoint and they'll still be just as playable.",
"There is a concept known as being \"Turing complete\". Something that is turing complete is at least as powerful as any other turing machine. if we oversimplify an entire course on computability, once something is turing complete it can do literally anything that a computer can do (barring practicality and hardware / software restrictions). Oversimplifying further a \"thing\" wanting to be turing complete only needs to: 1. Be able to execute instructions. 2. Support conditions (If X, then Y) 3. support some form of conditional loops (While X, do Y) 4. Be able to read and write into some storage medium (say, excel cells). That is the bare minimum you need to become a computer, and do anything that a computer can do. Excel can do all these things with the plethora of features, scripting languages, and cell-based design easily. Because it can do that it can do anything that a computer can do, even if it's incredibly impractical. You don't even need to resort to the more fancier scripting languages it has built in, with great effort you could just use the built in equation parser and basic functions to drive the entire thing. The conditions of being turing complete are so lax in fact we're struggling keeping it *out* of software. Powerpoint is turing complete, assuming you have the hundreds of hours required to \"program\" even the most simplest of programs in it."
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8lvegb | What is swarm intelligence and how should we use it? | Technology | explainlikeimfive | {
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8lyaj5 | How does the google's "I am not a robot" reCAPTCHA work? How are they able to differentiate between a physical click and a programmatic click. | Technology | explainlikeimfive | {
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"So a lot of people are talking about the image recognition and not the tick box you're talking about so I'll chime in here. Really it has nothing to do with the 'click' and everything to do with what happens before that. The way your cursor moves across the screen. If it immediately snaps to the box in a perfectly straight line then it's definitely a bot. Same with perfect curves. Human mouse movement, when you look very closely, is erratic and imperfect and that's quite hard to replicate with mathematical functions. Edit: so a lot of people have pointed out they're also checking cookies, Google account, headers etc. for a history of bot-like activity. And yes, while you could record human mouse movement and replay it, I doubt it would work more than once, and identical movement to a previous attempt is just as suspicious. Thanks to everyone contributing to this! Especially the people who know more than I do",
"As I recall, the \"I am not a robot\" is not a real CAPTCHA device. It's not meant to suss out humans vs robots. Google tracks statistics behind the scenes and if your activity looks human, it will offer the \"I am not a robot\" checkbox. Start doing things too quickly/frequently and it will engage the actual CAPTCHA test \\(Click all images with cars/signs/storefronts/whatever\\-else\\-Google\\-needs\\-to\\-train\\-its\\-self\\-driving\\-cars\\-to\\-identify\\).",
"Heyyyy, my time to shine. I'm an info sec project manager at a financial institution and we just completed a project to implement reCAPTCHA at our login. Ok, so essentially there are two \"steps.\" Step 1 - as soon as you load up the page with CAPTCHA, a TON of info gets sent to to Google. IP address, browser information, all your mouse movements, etc. Then, all that gets fed into their proprietary machine learning algorithm. Google keeps secret what information the algorithm pulls in and looks at. We do know that tracking and anlyzing mouse movements is one of the things it does. Based on that, if it thinks you are human, you just get the checkbox and you get to move on. If the algorithm still isn't sure, that's when you get to step 2, the second request to do the picture matching. You don't have to get the pictures perfectly right, because again, while you are doing it, it's also tracking everything else, like mouse movements and click rates and such. Until the secret algorithm is satisfied that you're not a robot. Bonus info: once Google decides you are human, you get a unique token representing your log in attempt. Then, you provide that token to the website you are logging into. The website then takes that token and independently checks with Google to see if that login attempt was successful. Google confirms and you are then let into the website.",
"IIRC it kinda tracks your mouse as it moves around and makes sure it doesn’t like jump around or move in super straight lines like a program would. It makes sure that when you go to click, that there are some human movements in there.",
"As far as I am aware, the majority of CAPTCHAs decide whether you are human or not on their own, they'll look at things like how your cursor moves (if it always moves in dead straight lines for example), and in general how much variance there is to your actions. Anything else (typing in the fuzzy word, \"click all squares with a shopfront\", etc) is just you helping to train their machine learning to recognise the images. You can test this if you get a CAPTCHA that gives multiple challenges in a row, often, if you pass the first one successfully (the actual test), you can do the following ones slightly incorrectly and it will still pass you, because it doesn't know the answer itself, you're telling what the correct answer is.",
"A lot of you provide very good information but I don’t feel like you completely answer the question. Googles recaptcha has had many variations. One that was a prompt, recaptcha v2 iirc which was only a checkbox and sometime the select all bridges prompt would show up, and no captcha. The original captcha was easy to understand how it works. Type the words that’s it. Recaptcha v1 was just a way to identify google street numbers, OCR for books, and a bunch of other things like photos of humans and what not. The recaptcha v2 used tags like recent browser history, screen size, user-agent (kinda like a fingerprint of what browser you’re using chrome, edge, Firefox), and pretty much whatever other data it could gather or even further authenticate with googles massive collection. If the check failed it would prompt you. No captcha is pretty much the same thing as recaptcha v2 except it does it all in the background. Some additional data google looks for when checking if you’re a robot or not are: browser size, database IP address (most likely using a service like maxmind), how fast your mouse moves, how fast you type, how old is your browser (history, cookies), who was your referee, and any possible artifacts left by libraries / tell tale signs you may be making programmatic requests such as incorrect user agents, headers of requests, and any other signatures of sorts. Source: I’ve worked in the ad industry where it was crucial to identify fraudulent ad watches, clicks, and skips. We had to use many rigorous techniques to monitor and determine if a user is truly human. Compared to our standards google is a little more slack.",
"top edit: realizing that this is more me letting off steam than an actual answer; here is one: What they differentiate is not the click itself but the way the *viewer* interprets the given image. There are fundamental differences between image recognition by image processing and image recognition by natural intelligence like ours. Where, for instance, a computer could analyze a scene and detect that a cup of tea is right next to the wall, a human would make a more contextually relevant description and say that it is on a table (that is adjacent to the wall). The computer vision analysis wouldn't be wrong, but it would be weird way of estimating the cup's location. Looking out for such differences of awkwardness (omitted details, mouse movement, answering speed, in what way your answer was incorrect etc.) by analyzing real answers and computer generated answers, these satan's-hellgate-keepers can allegedly differentiate if it is solved by a real person or a robot. now, back to why I hate them with a passion: **** this comment is probably going to get lost amongst others but I need to get this off my chest. I HATE THE I'M NOT A ROBOT RECAPTCHA. Every time I'm presented with one I'm sweating bullets. What constitutes as natural intelligence? What am I supposed to consider as **a part of a vehicle**? Should the 3 pixel corner of a street sign in the 2x3 cell of the grid be selected, or is a \"human\" supposed to overlook that and go for the major cells? is the windshield barely visible at the bottom right corner of that other cell mean that I should select it, or am I supposed to not see it? All my recaptcha tests take like 6 turns and I genuinely struggle with proving my humanity. And don't even get me started with text recognition. Half of those things are fucking hieroglyphs. Is it an ugly capital P? is it a lowercase f with an offset and some random distortion? I've seriously been locked out of my accounts because of how gloriously I can't prove that I'm human. I think the problem is that computer vision is so good at mimicking human vision at this point that these recaptchas with deep learning training got to a point where AI is better at being intuitively human than a regular human with a shitty, blood-powered, imperfectly replicating primate neocortex. edit: or I have some form of brain damage, but I prefer to go for the option A.",
"There is a robot to beat the ReCaptcha. I think it explains well why: [ URL_0 ]( URL_0 )",
"i used vpn and this fker is so annoying, i just want to do google search, it is not google fraud but ...",
"I was told by an IT guy that when you do the picture reCAPTCHA's, you are actually training robots to recognize pictures. You are submitting data and essentially working for free. So now, I do them a little bit wrong and it takes a little longer but I'm not training someones robots for free. Fluff that. They can pay me if they want good quality stuff.",
"It's not about the click event itself, but rather what you do before you click. If your cursor naturally glides across the screen or has a lot of unpredictable movement the captcha classifies you as human and let's you proceed. On the other hand, if your cursor is darting around clicking everything precisely it might classify you as a robot and make you do the picture matching or character identifying activities. Bots usually target specific page elements than artificially drag the cursor around and artificially click so this is a good solution to negate bots. Sometimes theres false positives and the captcha goofs, making the user do the activities but nothing is perfect, so it's understandable.",
"Also if you're signed in with a \"trusted\" Google account it will just give you the check box",
"It's not always the click that matters. Sometimes it's mouse movements. It uses your Google account history to verify you too.",
"It tracks how you move your mouse, your IP address, cookies and other valuables. [This is a great video about it]( URL_0 )"
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8lyikc | Nintendo Switch system requirements are a max of 32g for SD card. Why wouldn’t a 128g be compatible? | Technology | explainlikeimfive | {
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"32gb is the largest size allowed in the SDHC standard, so it may be possible the Switch doesn't support SDXC cards and the ExFAT file system. Edit: the Switch did not support SDXC cards upon release, but a later system update added support for them.",
"They chose to only support up to SDHC and not SDXC(edited) You look at the plastic and think all SD cards are the same but your computer treats them differently based on size and needs to know how to talk to each Basic SD cards are up to 2GB and are formatted with FAT16 SDHC(High capacity) are formatted as FAT32 and support 2GB to 32GB SDXC(Xtreme capacity) supports 64GB to 2TB and is formatted with exFAT To you they all look and behave identically, but if your SD card reader doesn't know how to handle exFAT formatting then it doesn't know how to store or find files on the card and can't read it As for why Nintendo cheaped out, that I'm not sure",
"The Switch supports SD cards up to 2TB. Others have outlined the limitations of *types* of SD cards, but none of that applies to the Switch, which has supported high-capacity SDXC cards since launch."
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8lywy4 | what is actually stopping us from exploring the bottom of the ocean? | Technology | explainlikeimfive | {
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"It's very expensive to explore there. We have already sent submersible craft to different parts of the ocean floor, but it's just very expensive to do. So unless there is some specific reason that you are searching for something, there needs to be a reason to justify the cost.",
"As you go further down the ocean, the pressure exerted on your body increases. This is because of the increasing volume of water that is pressing down on you from above as you go deeper into the ocean.",
"Insanely expensive to make an underwater vessel that can withstand the water pressure that far down. And there's really not much of interest down there, at least, from a \"can we make back the huge amounts of money we spent doing this\" stance."
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8m05zr | Why can't people make screenshots vector images? | Not sure "vector images" is a proper terminology here. I can only describe that as something like fonts, which are defined by mathematical formulas. Imagine how handy would it be if screenshots were scalable to any size. What's more, the size would be much less compared to an image and the text could be selectable. | Technology | explainlikeimfive | {
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"Computer scientist with a visual arts master's thesis on generative typography here. As you suggested most* fonts, as well as other vector images, are defined by their mathematical abstractions. So each time the operating system needs to display one of those, it decodes those mathematical definitions and generates a pixel image that can be displayed on screen. This is necessary, because the screen is literally a two dimensional surface made up of small squares, i.e. the pixels. When you capture a screenshot, it is a copy of the image that has been sent to the screen. So the information that has been used to create that image (including but not limited to the mathematical definition of the vector image) is lost. In addition to that, every application with a graphical user interface (including the operating system itself) has its own method of dealing with the rendering of a vector image and these methods cascade. As an example, when you type something out in notepad or Illustrator, those applications go and fetch corresponding letters from the font file (which is a library of vector images), rasterize them (generate pixels from vector information) and then render them within their application window. That application window, already a pixel map, is then used by the OS to be displayed on the screen. So the conversion isn't even single step. In order to take vector screenshots not only the OS has to know how to retain and serve the initial vector information, but also the applications in between the final screen image and the rendered vector file should successfully keep and send forward the information. *I say most fonts because there are bitmap fonts now like emojis. edit: *but* and I'm just spitballing here, if there were a custom screen capture software that has access to system resources that could hypothetically startup a virtual desktop with arbitrary screen resolution, it could temporarily create a larger screen buffer and grab that image. It would still be bitmap in the end, but it could be larger than what you see. But I think that would be limited, too, since the maximum resolution output depends on the graphics card. So the bottleneck would be that.",
"Vector image are defined in terms of lives and curves. Raster images are defined in terms of pixels. A screen is a a raster image. Capturing it doesn't change that. If you want a vector image, you need to recreate it without having all the original information. And it won't really be any better than just rescaling it on the fly."
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8m0xq8 | How do software distribution platforms (such as Steam or Play Store) verify the security of the software they offer? | Do they manually read the code or do they have some tools to help them test it for malicious code? | Technology | explainlikeimfive | {
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"Well steam has no quality assurance at all, you can purchase games with actual money which do no even contain .exe files. Malware HAS been sold in the platform before."
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8m13n8 | Data storage. How are drives becoming much smaller but the storage capacity becoming much greater... | Technology | explainlikeimfive | {
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"Your teacher tells you the final is 1page open notes. First start making your notes using normal pencil and 8.5x11. You run out of room, so you decide to redo the notes using sharper mechanical pencil with regular 0.5mm lead and you write smaller letters. You run out of room again and you decide to use even sharper 0.3 mm lead and write even smaller. The individual data box where hard drives are writing data is getting smaller and smaller. You used to be able to measure it with a ruler. Now you can't see it with a regular microscope"
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8m1crq | why is lithium hard to recycle? | So I was listening to NPR and they said contrary to popular belief, the environmental problems with lithium are not the mining but the recycling. They said lithium is notoriously hard to recycle which is why we send our tech waste to Africa. Why is lithium harder than aluminum or steel for the purposes of recycling? Why can’t it just be melted and reformed? | Technology | explainlikeimfive | {
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"Lithium reacts different than many other elements, and because it's so light (atomic number 3, just below hydrogen) if it catches fire, it flies away. Currently millions of dollars are being driven into finding a good way to do it using either chemical reactions or dissolving in water, that are also cheap and non-polluting. Likewise, similar research is being carried out to find how to extract the huge amounts of lithium in sea water. The race is on and whoever can figure it out first is going to get very rich very fast, taking in old cell phones and e-car batteries. My bet is on vibration seperation.",
"The ELI5 answer is: it's much more difficult to recover the metals and alloys in a usable form. You can't just melt down batteries and end up with reusable lithium due to its chemical composition. If you recycle batteries containing cobalt, you can make the process somewhat economically feasible, but otherwise, not so much. URL_0"
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8m5yb3 | Why do car alarms have that one sound? | Is there any reason behind that weird consecutive combination of sounds car alarms make? Does it symbolise or mean anything or is it just because of the simplicity of devices that create it? | Technology | explainlikeimfive | {
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"It's a collection of all the alarm sounds that were available for various things before that. What it tells *me* is that someone got an aftermarket alarm for their car that isn't particularly well designed/managed, and that I'm extremely unlikely to bother checking to see who set it off. The OEM alarms that just use the car horn are almost as bad. The GOOD ones are the ones that chirp a warning when movement is detected, and require persistent disturbance before they go off for exactly 1 minute with a shrill single warbling siren. After that, a tracking service is notified. That's the only decent alarm system I've seen out there, but it's significantly more expensive than the useless ones most people install.",
"That sequence is actually from the ability to customize to just one of the available sounds. There were/are connections that can be cut inside to eliminate the unwanted sounds, playing only the connected sound(s). The installation instructions told the dealers how to configure this option, but most dealers didn't explain that to the customers because of the additional time for deciding and the configuring what the customer had selected. I speak in the past tense, because I assume that those are a thing of the past now.",
"Something to keep in mind: the vast majority of aftermarket alarms are made by the same company: Directed. Viper, Clifford, Python, Avitol, AutoMate are just a few of their brands. They are the Luxottica of aftermarket auto security. They share a lot of technology and designs between their brands so that’s why that classic alarm sound seems so common. That setting is the default alarm sound for most of these systems. Most can be customized for one of those tones or just f’it play them all."
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8m626x | Why are all these companies updating their terms and services right now? | Technology | explainlikeimfive | {
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"text": [
"New Data protection rules came into force in Europe today ( 25/05/18 ) So any company that serves people in Europe have to adhere to the rules, so are changing policies globally to become compliant.",
"URL_0 It's a result of the General Data Protection Regulation that entered into force. It's European law that serves to make companies more transparent in how they collect and use private data and to protect the rights and privacy of EU citizens (but because the European market is so big, it basically has global reaching consequences)."
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8m7zv3 | . Why does some media from the 60's and 70's look horribly grainy and other media crystal clear? | Technology | explainlikeimfive | {
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"There are several factors, including: * whether it was shot on film for theatrical release, or videotape for TV broadcast * the quality of the equipment and film stock used when shooting on film * how well looked-after the original was, and how much it degraded over the years Good quality celluloid film provided fantastic \"resolution\", better even than 4K. (I put \"resolution\" in quotes because it's not really appropriate when talking about celluloid film.) But that kind of film needs a lot of light, so the studio has to get lots of expensive (and, in those days, really very hot) lighting. Film that works in lower light levels is more visibly grainy. Film noir was a genre of movie that worked around these limitations: these are those cheap black-and-white movies, often crime thrillers, known for their creativity in using shadows and patterns of dark and light to evoke a particular mood without needing so much expensive equipment. Anything made in those days for TV, though, will be very low resolution. The NTSC standard used in North America had a total of 525 lines, while the PAL and SECAM systems used in Europe had 625 lines (and in the *very* early days, British TV had only 405 lines). Not all of those lines were even visible, so when DVD Video first came out (designed for these early systems), it had a vertical resolution of 480 in North America, and 576 in Europe. Put that on a 4K screen (with a vertical resolution of 2160), and you can probably see the individual pixels. In answer to your question about photographs, the graininess of them is due to the limitations of *printing* technology at the time. The original photos would have looked pin-sharp, but in a cheap publication they would often look quite bad. If you look at a photo in a newspaper from the period, you can easily see the individual dots. Very often, if high-quality illustrations and photos needed to be included in a book, they were printed using a different process and inserted into the book later. Those pages were often kept together near the middle of the book, and were noticeably glossier and thicker than the other pages. The text would refer you to, for example, \"fig. 3 on plate 4\", and you'd have to look for that page if you wanted to see the image.",
"Your blu-ray was probably a remastered version. The original physical film that the movie was recorded on is extremely high resolution so if they make the blu-ray from that, it's high quality. An older copy of the movie is low quality because you're watching it from a VHS tape, which is both low res and can degrade over time. The reason a lot of media that old looks bad is simply that they're copies made from a low quality medium instead of the original high-res physical film. Sometimes the original film is lost. EDIT: \"Remastering\" is when they make a new master copy of a movie from the physical film which is then duplicated for distribution.",
"To add onto /u/santaforpriscilla's wonderful answer, your 4K teevee with 16:9 aspect ratio is roughly 8.9 megapixels (MP). *The Sound of Music* was shot on 35mm film using damned good equipment. Each frame of average-grade 35mm film is roughly 25MP. High end gear, like used for this production, can be up to 50MP per frame. So when the movie was remastered for BluRay, the source used was *at least* three times more visual data than your teevee could show."
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8m8wob | How were photographs edited prior to advances in editing software? i.e. those old photographs of Stalin where people were phased out | Technology | explainlikeimfive | {
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"For that kind of thing, they literally used an actual airbrush -- which is why photo editing software has \"airbrush\" tools, and why we use the word \"airbrushing\" to mean both retouching of photos and the practice of excluding people or events from the history books. A skilled artist using a small airbrush would paint over the object that needed to be removed or manipulated. Usually it was small things like unsightly objects or skin blemishes (in fashion photography): the removal of entire human beings from photographs was rare and extreme, but as you say there are some famous examples of this during and after the Stalin era.",
"There are multiple techniques you can use for manual/\"analog\" retouching, pre-exposure (scratching, painting the negative), during exposure (exposing different parts of the photo for different lengths of time), and on the print (airbrushing, painting), to name a few. As for the disappeared persons in Soviet photos: they were airbrushed away."
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8m9av1 | What are the moving vertical lines that appear on my TV when I'm taking a photo or video? | Technology | explainlikeimfive | {
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"dzlrnor"
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"text": [
"Your TV draws images on the screen in stripes. Left to right, top to bottom. The lines are drawn so quickly that our eyes can't see them being drawn and it looks like smooth motion -- in much the same way that we don't see cartoons as individual drawings or cells. When you see those lines in a picture it is because you have frozen the movement and can see what has been there all along."
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8m9mbv | if black is the absence of light how do phone screens produce it. | Technology | explainlikeimfive | {
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"text": [
"They don't produce it. They simply turn off all pixels in the area. They can't go any darker. But it seems darker because adjacent pixels are lit."
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8m9p0c | Why does every software support team send me a new terms of service? And what do they mean for me as a user? | Technology | explainlikeimfive | {
"a_id": [
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"text": [
"EU's new data protection law (called GDPR) came into effect the 25th of may. It says that basically all (user) data collection should be disclosed and opt-in. This means that every service that ever collected data has to update its EULA in order to do business in the EU.",
"URL_0 Privacy Rules and Protections are changing in Europe soon. Software companies want to remain and business and not get fined. In order to comply changes to your applications required updating the agreements that your being asked to read and confirm. You might not be European but a bunch of people are. It is easier for the Developers to cover everyone with \"strictest\" rules. Help?"
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