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jokgyp | Why are HD TV channels and regular TV channels separate channels? And why can’t there just be HD channels? | Technology | explainlikeimfive | {
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"All older standard definition TVs can't display HD information, but the problem is that some older standard definition TVs can't process HD information. Since they can't convert HD into something that will fit on their SD screen, they can't show the channel at all. Telling someone \"your TV is too old to use on our fine service\" is sure to cost you a customer, and the cost to put out an SD version of the signal is very low. Since channels are \"free\" to send out, you spend very little to keep a few customers."
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jol6fu | Why do tech companies have a very high turnover rate? | Technology | explainlikeimfive | {
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"Software Engineer here! There are a few factors that combine for high turnover in the tech field 1. Wide availability of jobs 2. Pressure to have a wide variety of technologies in your toolbox 3. Changing jobs generally yields higher pay Companies usually use a single set of technology. One type of database, a cloud provider, a backend, and a frontend. If you want to get experience with different technologies you have to move around to jobs that use different technologies. There are lots of jobs out there relative to the number of people who can work them. This creates a competitive hiring environment. Companies are willing to pay a premium for more experienced developers and make great efforts to higher them away from other firms.",
"There's also no loyalty from a company, especially larger ones. They demand your loyalty, but refuse to give any in return. At least in my early experiences.",
"There are two major reasons. First, salaries tend to be flat when staying in the same job. You can get a 2-3% raise per year to keep up with inflation, but it is hard to argue that you deserve a significant raise at any point because most of the day to day stuff is the same. Tech already natively has this need to keep learning, so unlike other professions like teaching, where going out and getting extra courses can result in salary bumps, it's just something you're expected to do in tech. Second, most mature products tend to be pretty set in stone with the technologies they're using. Unless you jump jobs, you're going to be in a bit of a rut with what you're doing day after day. Changing jobs is the only way to keep a lot of things fresh.",
"I work at a tech company in a non-tech role and we have horrible attrition rates all over, for a lot of reasons. If anything, the great benefits can sometimes make you feel like you're being held hostage because of the pay increase required at other companies to cover the benefits being lost. If I weren't a woman looking to start a family and thus might be taking advantage of the adoption subsidy if we can't conceive within the year, I'd have left after my 4th year here. 1. The office amenities are a trick to make you feel more comfortable and encouraged to put in extra hours at the office. 15 hours days suck, but 15 hour days with a keg at your desk you're allowed to use after 6pm and a separate gaming lounge to hang out with your coworkers make the long hours seem more palatable. You're not given overtime though, thereby devaluing your salary. It's not unusual for anyone an entry level manager above to regularly work 50+ hours a week, sometimes significantly more. We did the math on emails once from one of our directors of operations and she was working from 6am-10pm most days, with an acknowledged 2 hour break to hang out with her son when he got home from his extracurriculars and they had dinner and did homework together. 2. The pay is nice in some roles, but a lot of tech companies only pay their programmers market wage, everywhere else is below market value and they say the benefits make up for it. That might be the case in dollar value, but not everyone needs access to IVF & Adoption subsidies, top of the line insurance, all the discounts we get on cars and other random partnered companies, bariatric surgery, etc. A lot of our benefits value comes in the form of what if. The only piece everyone uses is the health insurance. 3. Other companies may match 401k contributions, but ours doesn't. That's a hit you can take for a couple years, but it's not a smart financial hit long-term. 4. The directors play a lot of lipservice to a lot of issues, but it's 2+ years of promises before anything in the process is even partially fixed because everyone's overworked and running on fumes all the way down to the bottom. We were running on a shoe string before they did a bunch of layoffs to streamline operations, but when we did the layoffs (precovid), we didn't actually reduce the work going into those teams. 5. At our company, nobody takes responsibility for their mistakes, they pass it off to the lowest person on the totem pole that they can. Bad managers fuck everything up across the board. If you're the lowest totem pole on your project, you are the group punching bag for mistakes. 6. At our company, we also have a huge issue of siloing where the people programming our shit have independent goals from the business and the rest of the company, and nobody has done anything in the at least 7+ years we've been in existence to fix that. As a result, pretty much everyone in tech has to scramble to complete their own work, plus all the random business critical shit coming down the pipeline they didn't know about because we just simply run backwards for no reason except no one has the time to sit down and fix it. 7. At our company, we also go through 1-2 reorganizations a year. Idk if that really has an impact, but it's certainly obnoxious. You'd think we were some rando fucking company and there's no way we could exist, but our company is a household name that everyone has heard of and we regularly turn profit in most of our branches. There's literally no reason except ego and overwork for us to be operating on this level."
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jonm6m | Why does 24fps anime look better than 60 fps anime? | 60 fps anime just looks weird, I don't know if this is just my personal preference or a shared opinion. | Technology | explainlikeimfive | {
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"Because 60fps anime is interpolated (almost two thirds of the images are drawn by a computer guessing from two neighboring 24fps frames). Anime properly animated from the studio at 60fps would look way better than 24fps - but also cost 3x as much."
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joppkm | Is the amount of QR codes finite? | Technology | explainlikeimfive | {
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"For a given size of QR code, yes. Just like there are finite amount of sentences that are 100 characters long, for example. *Exactly* like that, in fact, since a QR code is just another way of displaying a string of characters. But for *practical* purposes, no, there are too many.",
"Short Answer: Yes. The amount of QR codes are finite. Long answer: There are many standards or versions of QR codes about. Each is a grid of pixels with certain pixels spoken for and the rest intended to store the data it wants the user to read. For instance, the [picture here]( URL_0 ) shows which pixels of the standard 7 QR code are reserved to either help the camera target and read the QR code or convey meta data like version or format. The grey is what's left to convey information. Every pixel in that space increases the amount of different \"states\" the information can be in. For instance, if there was just one pixel, it could hold 2 states. 1 for a black pixel and 1 for a white pixel there. If there were two pixels it'd have 4 states, (black, black) (black, white) (white, black,) and (white, white). The formula for the amount of different states per pixels is ~~pixels^2~~ 2^pixels, since the addition of another pixel multiplies the number of possible states by 2. This is a one to one comparison of how computers use bits and so translates quite easily into code your phone can understand. There's nothing stopping people from creating more QR formats with even more pixels though. So in theory the number of codes are infinite. In practice, we'll eventually reach a point where it just isn't practical to see every pixel of a giant image with a camera phone."
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jopz1f | if black is the absence of light, how do black lights work | Technology | explainlikeimfive | {
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"\"Black light\" is just a marketing term for ultraviolet lights. Ultraviolet is outside of the visible spectrum, and while some violet tends to be produced as well, you can't see most of the light produced by a black light, hence the name.",
"Black is the absence of visible light. Black lights emit Ultraviolet light (UV). Some materials when exposed to UV absorb it and re emit the energy by glowing with visible light. This process is called Fluorescence.",
"I'll keep it simple but it's a bit long. First, some background. Light is just electromagnetic waves. (We'll ignore the dual nature of light and the fact that it sometimes acts like a particle). Waves of any kind can be described by amplitude and frequency. Amplitude is how big the waves are, frequency is how many waves are in given chunk. What about wavelength? Don't worry, wavelength is just 1/frequency and it's not really important for this answer anyway. Just remember that at the same amplitude higher frequencies have more energy. Think about wiggling a slinky, it takes more energy to make big swings but if you keep the swing size the same it takes more energy to make lots of swings quickly than it takes to make a few swings slowly. Our eyes are able to detect a small band of electromagnetic waves. We call that band the \"visible spectrum\". Different wavelengths look like different colors to us. The lowest frequency we can see is red; anything less than that we call \"infra red\". The highest frequency we can see is violet; anything more than that we call \"ultra violet\". All the other colors are the frequencies between red and violet (that's why the rainbow has the color order ROYGBIV). Most substances absorb some light and turn it into heat and reflect some light. The reflected light is what we think of as the color of that object. Some substances do a weird trick called \"florescence\". They mostly absorb light like normal but they'll take a few very specific wavelengths, absorb them, turn some of the energy into heat and emit the rest at a slightly lower frequency. So back to your question. Black is the absence of detectable frequencies. You can be in a completely dark room but there might be x-rays streaming through that you just can't see. They're dangerous so don't do that. Black light is ultraviolet light. When it hits most substances you don't see them because reflected ultraviolet light is still ultraviolet. But if you have a florescent substance it will emit some of that ultraviolet light in the visible spectrum. That's what gives you the weird effect in a club.",
"Black lights are just the nickname for ultraviolet lightbulbs. Ultraviolet is a color past purple on the spectrum that we can't see. You'll seem some of the purple light that is also being emitted but the main point of the light is to emit invisible uv light which causes the blacklight posters to glow."
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josrm8 | How does Google Search find out thousands of results from the entire web in an instant, while my fairly large Excel spreadsheet can take a good few seconds to find a particular cell value? | Technology | explainlikeimfive | {
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"Google does a LOT of indexing and caching. Indexing is where they categorize pages based on keywords, popularity, credibility and a bunch of other signals, and they search the index for results that fit your search criteria, rather than searching each page when you request a search. Caching is when they store frequently accessed searches and search results in fast access storage, so when multiple people search for \"election 2020 Florida\" they don't even consult the index after the first result, they just reuse the cached result from before This is a very simplified explanation, in practice is a LOT more complex, but the idea is the same.",
"Your PC is running on limited RAM/CPU where as Google is pretty much running on unlimited capacity"
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joszeu | Why do older 3D graphic games look worse to us than retro 2D games? | Looking at old 2D games and usually the graphics are aesthetically tolerable if not pleasing. Looking at old 3D games, like early era Playstation, and it's unpleasant to look at. Is it because 2D pixelated games are more like "art" or is there something fundamentally offputting to our brains about older 3D graphics? | Technology | explainlikeimfive | {
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"It’s similar to t he “uncanny valley” phenomenon if you know what that is. Basically, the closer some tries to look to real life, the more our brain finds the imperfection in them disturbing, as if you’re looking at a disfigured person. But for things that don’t look close to real life, our brain doesn’t make that connection, instead it just sees the colorful pixels for what they are, colorful pixels. Plus, with 3D games, you’re generally comparing them to real life and modern 3D games, and you can really see just how bad they were. 2D or cartoony games you don’t see that as much becuase they’re not as comparable to other modern games, instead it’s just their own unique art style.",
"\"Retro\" 2D typically refers to the 16-bit era of video games which include the SNES. At this point, 2D graphics have already had 20 years of refinement since Pong. The early 3D games were really the first few years of 3D graphics in all aspects (models, textures, animation, hardware). When you compare the new 3D graphics vs 20-year-old 2D graphics, the 2D graphics would look better."
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jot9e8 | Why is it so difficult to emulate modern video games on PC? | Shouldn't it be easy for a modern gaming PC to handle games like Mario Kart 8 or Bloodborne, that were designed to run smoothly on much lower spec consoles? | Technology | explainlikeimfive | {
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"Emulation is hard. Imagine that you have to try and hold a conversation with someone in a completely different language you have no idea about. You have a really good dictionary, but every time you want to say something, you have to look it up, and every time they say something, you have to look it up. It would be very slow to hold a conversation that way. That's roughly how a software emulator works. It's translating how the original program was written into something compatible with your PC, but has to do so one step at a time every time. If you press a button, it has to translate that into input that the video game can understand. When the video game wants to make a sound or display an image, it has to translate that into an image or sound that your computer can understand. Doing this fast enough so that you don't notice major lag when playing the game requires a REALLY fast computer.",
"It's not so much the requirements in terms of performance. It's that the games are written in a very specific way. The way the code is written is designed for specific processors and hardware. This requires a translator. The emulator effectively translate the process to one the pc understands however thus is very complex and surprisingly resource intensive. It also often requires emulation of the hardware. So using software to make a virtual version of the console. This is also very resource intensive.",
"\"Low spec\" is relative. The SNES runs at ~4 MHz, but more modern systems like the Wii run at over 700 MHz. Your home PC CPU is probably somewhere around 3,000 MHz for a reasonably good one. But remember that this is not the same type of CPU as in your computer. You most likely have an x86 CPU. A Wii runs a PowerPC CPU. They don't run the same instructions. Either the emulator needs to simulate the PowerPC CPU's fetch/decode/execute loop in software which is going to SERIOUSLY cut into the performance, or rewrite the CPU instructions into something the x86 CPU can run in its place but it's still not a direct 1-to-1 translation. Your ~3,000 MHz CPU may not be able to keep up without cutting some corners for safety. But that still only covers the CPU. The game system also includes a disc drive, connectivity to the controllers, a sound and video card, etc all of which also have to be simulated faithfully. The game expects to interact with the exact hardware that the real game system has and the emulator must simulate all that stuff accurately. Asking a piece of hardware to act like a completely different piece of hardware is HARD."
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jotgjo | Why is a hard drive so much bigger in comparison to a SD Cards or USB stick, even though the storage space is the same? | Technology | explainlikeimfive | {
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"Because a mechanical hard drive needs to fit its spinning platters, optical reader assembly, and controller circuitry into its chassis. Flash memory devices like USB sticks and SD cards have no moving parts, storing their data directly on a chip. Therefore, they can be much smaller.",
"The method of storage is completely different. Hard drives using spinning platters coated in a ferrous material. Individual 1's and 0's are stored on the disk as magnetic imprints. Data is stored on the disks in spirals so a hdd disk is read like a vinyl record. SSDs, USB sticks, etc store data in microchips. These circuits can be imprinted on a die at the microscopic level allowing for huge amounts of data to be stored on the silicon. As processes get better more and more storage can be put on the same amount of space. Spinning Hard disk drives are still the highest data density for the $. You can get spinning hard disks that can store upwards of 20TB. SSDs how much are orders of magnitude faster, mainly because they have no moving parts. They are also getting better and better all the time because the technology is so much newer than hard drives."
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joumso | Why do laundry baskets have holes all over? | Technology | explainlikeimfive | {
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"This is to create ventilation for your dirty clothes so that bacteria have oxygen - some bacteria under non-oxygen (anaerobic) conditions grow and produce foul smells, which is why if you leave dirty clothes in packed plastic bag a smell develops"
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jouzl0 | I hear people use the term “n-bit systems” when talking about computers. What exactly is the meaning of said term? | Technology | explainlikeimfive | {
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"It’s the memory addressing mode of the central processor. Today 32-bit and 64-bit are the most common. Not to get too technical think of it as the maximum size of a data type the cpu can utilize. 32 bit is a big number, 64-bit nearly unimaginable number something in the quintillions."
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jowz3l | for phishing emails to work, is opening up the email enough for spammers, or does a link within have to be clicked? | Technology | explainlikeimfive | {
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"If there are images embedded in the email and you load those images, you could be telling an attacker that your email address is valid and could result in more attempts targeted towards you.",
"While you can get viruses in several ways from emails, phishing typically refers to information gathering. Usually given willingly by the target. Examples: An email that appears to be from your grandma asking you to remind her of her account password, or an email from your bank that says to click this link and reset your password. The link takes you to a \"safe\" page that looks just like your banks website asking you to enter your current password to change the password. Except it's just a good copy of the website with a similar link address. No viruses involved. Just trying to get you to give up the info.",
"The email is the bait, it will usually be a notification about an account issue. The link is the hook and even if you click on it, nothing should happen, unless of course you allow your browser to run iffy scripts or plug-ins. But if you put your account information in and click send, you essentially gulped down the hook, since your information was now transferred to the people phishing for it.",
"There have been exploits from time to time that allow remote code execution just by opening the email, [especially for microsoft outlook.]( URL_0 ) However this is pretty rare. 99.999% of spam emails are hoping to trick you into clicking a link. In fact, clicking a link isn't usually enough by itself either, unless there is a zero-day exploit in your web browser at the monent. They also need you to enter your credentials at that link, or download and run a file."
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jox1ze | How the FBI "seizes" a website? How exactly does that work? | Technology | explainlikeimfive | {
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"They go to the DNS operator that points users to the site's IP address and tell them to point someplace else. They might go so far as to have the IP address rerouted, but that's less common.",
"So for a website to work the computer hosting it has to have a internet connection. < - For some reason people don't think about this or what that means. It is very easy to figure out the IP address of a website, you literally HAVE to know it if you want to go to the website. With the IP in have the FBI goes to the internet service provider and gives them a chose: Give us the address of the person using this IP or go to jail. Spoilers Comcasts CEO is not going to go to jail for 5 years just to protect someone's address. With the address in had they go to that address and give physically take over the server hosting the website. This works because when 50 guys with machine guns show up at your door you do what they tell you to.",
"They seize the DNS entry of the website and repoint it to their page Websites use DNS to resolve www. addresses to an IP address where the website is actually located. The FBI calls up the DNS host (sites like GoDaddy) and gets them to seize ownership of the DNS record and it gets pointed to the FBI landing page. So if you try to visit the site you get the FBI page instead. If the website is located onshore they can ask the hosting company to take it down, but if it's offshore chances are the website will still be online users just can't get to it. Nothing stopping the site admin from getting a new DNS name and be back online in minutes. It's just a question of getting the message out to your users, with things like twitter and forums that will take minutes. That's why trying to shutdown websites like this is often a fools errand because it doesn't actually stop them. Months worth of legal work undone in about 10 minutes, it's just a short term annoyance."
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jp0jqf | what is DHCP | What is DHCP and how does it work | Technology | explainlikeimfive | {
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"Let’s say you go to a restaurant that will only take tables for a limited amount time. So you go up to the hostess to get a table, the hostess asks how many people, and they inform you if they have a table available. If they do they will send you to the table for that allotted time. If they have no tables at the moment you’ll have to wait until there is a new table. Once you sit down and you stay the full allotted time you can ask to stay longer but only if the hostess says it’s okay. In this analogy you are the device looking to get online, the hostess is the DHCP server giving out IP addresses, the number of tables at the restaurant is the number of available IP addresses And the allowed time at the table is how long you get that IP address , the lease.",
"Dynamic Host Configuration Protocol When your computer connects to a network, it needs a number so that it can’t be confused with other computers. The DHCP server has a list of the numbers already given out and it gives your computer a new number that isn’t already in use so that everyone has their own number. —- There’s obviously much more to it than that but that’s the ELI5 version ;)",
"It's the protocol where your computer asks the router for an IP address when it connects to the network. Computer: \"Yo, any routers around? I want an IP address.\" Router: \"Sure, you can have 192.168.1.234 if you want. My IP is 192.168.1.1.\" Computer: \"Yeah, I'll take 192.168.1.234.\" Router: \"Okay, 192.168.1.234 is yours.\" and then every so often: Computer: \"Hey, I'm still using 192.168.1.234, yeah?\" Router: \"Yeah, that's right, 192.168.1.234 is still yours.\" Without DHCP, you had to tell the computer what its IP address should be, and it was easy to accidentally give two computers the same address."
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jp0l72 | Why did we count vertical lines for HD, but horizontal lines for UHD and 8K? | Back when Full HD was the best we had, we used the terms 480p, 720p and 1080p, where the number was the number of vertical rows. Now with 4K and 8K we seem to be counting horizontally (and less accurately to boot) Why the change? Is it just simply marketing (4K sounds bigger than 2160p), or is there more to it? | Technology | explainlikeimfive | {
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"mainly marketing. the way monitors work is that they draw each row one at a time. so 480p means 480p progressive scan, meaning that for each frame 480 rows are drawn. the other is 480i which means interlaced, where every other row is drawn for a frame and you need two frames to get a complete image. however 1920x1080 is the last resolution to offer an interlaced format. all resolutions going above 1920x1080 are by default (p) progressive scan. i mean sure there are things like 1440p but that's really redudent (since there's no interlaced format). and for higher resolutions, what're we gonna call it 2160p? and just increasing the number before the \"p\"? boooooring, right? so 4k/6k/8k/etc, mainly a marketing thing.",
"Big numbers sound better to the uninformed, uneducated, or egotistic. That might sound nasty, but it's just marketing. Unless you step back from emotions (ego) do your research and think critically, you are putty in the hands of marketing professionals who spend millions of dollars and hundreds of thousands of man hours trying to figure out how to sell people things they don't need. Big numbers sound better to your brain, they have \"more value\" when compared to smaller numbers, just like shiny stuff \"has more value,\" than something dull. For instance \"gold plated HDMI\" cable, etc. HDMI is literally DIGITAL, one's and zero's. Gold plating doesn't matter. It might for an analog signal over vast distances, but for digital it literally doesn't matter at all. BUT, it sets off the \"shiny\" or \"valuable\" part of our brains during the sales pitch. Gold is better than whatever this one is made out of, and I want the best! No Deserve the best! The same thing happens when you are making the choice between 1080 tv and 4K. * The distance that most people are separated from their tvs when they watch them, 4k tvs are indistinguishable from 1080. But data driven decisions aren't high up on the list of stuff humans do. We make \"gut\" decisions and have to train ourselves to use critical thinking, etc. URL_0 * To ELI5 most don't even BENIFIT from 4k, forgetting the naming convention, the actual advancement in tech isn't beneficial to most people spending the money. The facts are there, but the salesmen are there too, and often, they spend more time and money figuring out how to sell useless stuff to people, than people are willing to spend doing research.",
"First I'll define \"lines of resolution\": it's the number of alternating black and white lines that can be displayed, with the lines having acceptable contrast. Vertical resolution is measured in horizontal lines, and horizontal resolution is measured in vertical lines. Analog television resolution was traditionally most often a measure of ***vertical*** resolution, expressed as a number of horizontal lines, because analog television CRTs are horizontally scanning systems. The electron beam of a CRT sweeps across the screen horizontally to create horizontal scan lines, drawing them sequentially, each line just below the previous one, until the entire height of the screen is drawn and it restarts at the top. It's easy to quantify the vertical resolution of such systems, because the vertical resolution is equal to the number of horizontal scan lines (ignoring the effects of vertical filtering which some TV cameras employ). The more horizontal scan lines, the higher the vertical resolution. The vertical resolution of analog NTSC television, for example, is 486 horizontal lines, because that system has 486 horizontal scan lines. Horizontal resolution, in contrast, is difficult to measure in a horizontally scanning system, as it can be limited by the bandwidth of any component in the transmission chain. HDTV stuck to the convention of measuring ***vertical*** resolution in horizontal lines, as the first HDTVs were also horizontally scanning CRTs. The numbers in 480i, 480p, 720p, 1080i, 1080p, and 2160p are the numbers of horizontal lines of pixels, which give the vertical resolution. Also, describing the vertical resolution puts HDTV and SDTV on a level playing field, and doesn't give HDTV an advantage just for having a wider screen. 2k and 4k describe the ***horizontal*** resolution of a motion picture film scanner (2k is 2048 pixels and 4k is 4096 pixels). Film scanners have a line array of photosites that spans the width of a film strip, typically with a horizontal resolution of 2k or 4k. The scanners only read one line of image from the film at a time. The vertical dimension of the scan is created by continuously dragging the film strip past the photosite line array, much like how a flatbed scanner drags its linear scanning head down the length of a sheet of paper. The vertical resolution depends on the film format, since motion picture film is a continuous strip and can have frames of different heights, determined by the type of camera. Film scanners quickly became an important part of film production starting in the 2000s. The processed film negative from a motion picture camera would be scanned so that the film could be edited digitally, after which the digital edit would be printed back to film, or later, projected digitally. The convention of describing horizontal resolution carried over to digital cinema projectors, which are usually 2k or 4k horizontally. You may have seen your local cinema advertising some of its projectors as 4k. Ultra High Definition Television is 3840 x 2160 pixels, exactly double the horizontal and vertical resolution of 1920 x 1080 Full HD. UHD emerged as a consumer technology in the early 2010s, well after 2k and 4k were established terms in the cinema world, and thus UHD marketers just borrowed the 4k term, figuring that 3840 was close enough to 4096 to ignore the difference. That's created some confusion in the ensuing years, and you may sometimes see camera and projector manufacturers using the term \"Cinema 4k\" to mean 4096, distinguishing it from 3840 UHD."
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jp3ero | Why can't you install Windows/Linux on a PS4 or Xbox? | Technology | explainlikeimfive | {
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"Because Sony and Microsoft very strictly control what can run on these boxes. If they didn't then people could install their own applications and use it as a means of copying games or bypassing other protections. Consoles are supposed to be a safe place for developers to make their games and if piracy and cheating was that easy... It is worth noting that back in the day you COULD install Linux on a PS3. Sony removed it after it was demonstrated how to break out of the virtual machine environment it was running in. (This in spite of the fact that doing so required attaching things to the motherboard and sending it an electrical jolt with millisecond precision)",
"Lots of reasons: - These devices are locked down pretty hard by the manufacturers (using mechanisms like Secure Boot) which makes it practically impossible to flash alternate operating systems. There aren’t any active exploits that would let you do this on the current generation of consoles (although modders had a lot of luck with previous ones). - Even if you could somehow boot another OS, the internal hardware of these consoles is non-standard enough that none of them would work out of the box without major modifications to the source code and lots of custom device drivers. Also, technically Xbox does already run a variant of Windows.",
"Well, you CAN install Linux on a PS4 (don't know much about the Xbox). It's been done before. The big problem is that while the PS4 and Xbox One are x86, some of the internal bits and pieces are quite a bit different compared to every other PC out there. As such, hacking the console to run Linux was not trivial at all and took a lot of time and effort. If you'd like more info, there was a [great talk at 33c3]( URL_0 ) about the challenges setting up the PS4 to make it actually run Linux.",
"Let's say you're a company that makes consoles. Your primary income doesn't come from the sale of the consoles, it comes from the sale of the games. Anyone that wants to make a game for your console needs to pay you a fee, and maybe a royalty. You can afford to sell the hardware at a cheaper price because you make up the profit in the sale of games that the customer will inevitably end up buying. If people can install any operating system on your console, they no longer need to buy games through you, and all of a sudden, your primary source of income just dissapears. So logically, you would do everything in your ability to prevent this from happening right?"
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jp47hx | Why arent driver seats in the center rather than left/right? | Technology | explainlikeimfive | {
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"It's safer to be near the center of the road. Imagine trying to pass another car on a two-lane road, but the only way to see around the car in front of you was to move almost completely into the oncoming lane.",
"If you drive a car on a road with traffic there is an advantage to be towards the center of the road. If you are going to overtake a truck in front of you on a two-lane road you need to be able to see what is in front of you on the road. You overtake cars towards the center so if you sit close to the center you are seeing cars going in the opposite direction a lot sooner. You can compare how you can see ahead if you are a driver instead of from seat passenger in a car. & #x200B; Even if that was not the case the with of most cars is just wide enough for two people to sit comfortably side by side. So a diver in the center would remove the front passenger seat so it reduces the number of people you can transport. You can fit 3 people in the back seat of most cars but it is very cramped and would not like to drive a car sitting like that. A truck is often so wide so 3 people can fit side by side without any problem but three the diver is still to the side as you can see other traffic better in lots of diving situations. There are sports cars with the driver in the center but they can't in most cases have any passengers. They are quite narrow and you like the driver in the center for weight distribution reasons.",
"Aaaand nobody has stated the obvious... Its cheaper. It is also easier to get in and out. This has nothing to do with safety or visibility or any of those things. Even horse drawn carriages had an offset driver just so you could fit 2 people on the bench. Driver always sat on one side so it was easy to get in and out if needed. Don't overthink this.",
"Because it's an inefficient use of space on a normal-width car. It's also much harder to get into and out of the car. There are rare exceptions, like the McLaren F1 that had a center driver seat and tow passengers on the side but set back a bit.",
"Couple of reasons: Vision: coming up to a junction in a car with the driving side opposite to the norm will immediately demonstrate how much vision you lose. To be able to accelerate out of a junction onto the road, the junction is usually angled allowing you to be somewhat facing your intended direction of travel, the further you are from the normal side, the more of your own vehicle you have to look through, as opposed to looking through your driver window. In addition when following behind a vehicle you have a far more limited view past them for overtaking by being away from the centre of the road. Capacity: cars are designed to take people places, the more people in the car the more efficient and useful it is. Only cars in the extreme ends of design opt for middle driving positions, such as the Maclaren F1.",
"I believe it goes back to why us British drive on the left. Originally when people were on horseback you would pass other horses on the left as most people are right handed so your sword hand would be on their side. Same as jousting. When the coaches, roads and pavements became a thing, the driver of the coach would sit on the far right so his whip would be as far away from the pavement and pedestrians as possible. by him sitting on the right it made space for a second passenger to sit next to him. I would imagine that modern cars just evolved from that."
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jp5i3j | Why is the voice comms on walkie talkies and aeroplanes and helicopters still so bad quality | I just watched a video with voice comms on a helicopter, and the audio quality is atrocious and it was pretty recent (2018). Why is the communication not improved to some kind of digital equivalent and much improved quality? [ URL_0 ]( URL_0 ) Walkie talkies also sound horrible and an unfamiliar ear won't really be able to make out what people are saying. Over. | Technology | explainlikeimfive | {
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"Helicopters are partly down to the sheer volume. You've got the turbine engines and rotor blades producing a lot of noise to the point where hearing protection is pretty essential for all passengers. Filtering that out cuts a lot of the quality. As for walkie talkies, there's legal restrictions on the radio communications which limits bandwidth. Lower bandwidth, lower quality. Market forces are also at play - I doubt many companies will pay more when \"good enough\" quality is cheaper.",
"Pilot here- there's a couple things that factor into that. 1) Aviation uses AM radio to transmit voice on the airbands, and it has a very narrow bandwidth. This means the transmission is being figuratively \"crushed\" into a narrow range of frequencies. This is efficient in that a lot of frequencies can fit in the bandwidth allocated to aviation (when you consider all the towers, approach/departure centers, navigation aids like VORs and NDBs, etc in the US alone you'll see why efficiency is key). But it sacrifices some quality to achieve that. AM has been the norm since the early 19th century. 2) Most airplanes are old. Seriously. It might be a surprise to you, but in the US the average general aviation plane is almost 50 years old. This is partially because new planes are prohibitively expensive- it's almost always cheaper to keep an old plane flying. As a result, the skies are full of old radios and old wiring that also contributes to varying transmission quality you hear. Newer equipment tends to sound better. Could it be better? Sure. But nothing moves quickly in aviation, especially in the US. Changing over to FM radio would allow much better audio quality, but the sheer logistics of executing it would be mind boggling. Every plane, every control tower, every airport, every navaid, etc would need to get new hardware. In a world where a gas tank cap can cost over $100, the prospect of having to have a $2-5k radio installed is difficult to stomach for many plane owners, so an AM-FM switch would be a hard sell. In short, aviation radio sounds bad mostly because it's old technology that would be prohibitively difficult to modernize, and still does an adequate job of allowing pilots to communicate."
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jp6tfb | What's that sensation you get when you know a Television is on nearby even if you can't see or hear it directly? | Technology | explainlikeimfive | {
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"Its less common these days, but with old CRTs it was because the transformer whined at a barely audible frequency. CRT TVs worked by tracing an electron beam horizontally across a row of pixels to light up the right ones, then going to the next row and doing the same. The result was that the magnets that controlled the horizontal position and the high voltage flyback transformer that powered them ran at 15.5-16 kHz (525 lines x 30 Hz for NA, and 625 lines x 25 Hz for Europe and friends) which is on the upper end of the hearing range but within it for most children and young adults. You're less sensitive to high frequency noise so it didn't sound loud, but it was a very distinctive single tone against the background noise."
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jp98np | How come we can detect asteroids that will take decades to come (such as asteroid Apophis), but we can't detect a hypothesized planet 9, even thought supposedly it's much bigger? | Technology | explainlikeimfive | {
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"Asteroids like Apophis circle the Sun relatively similar to how the Earth does, meaning the body passes by Earth within fractions of an astronomical unit yearly. Once we recognize and catalog the body, we can track how it travels and determine the likelihood of collision. But all we have on Planet X is perturbations of other bodies, and Space is a big place to search. Even though Planet X is supposed to be larger than Apophis, it's going to seem smaller, just because it's further away, making it harder to spot. Especially at the hypothetical distance of 600 astronomical units from the Sun.",
"Don't take 'years to come' as an estimation of distance. When you hear 'years to come' that doesn't mean it's far away and getting closer. It means that is when the closest approach to Earth is. The asteroid and Earth are like two cars going around a track, slightly different paths and speeds. Sometimes they get kinda close, sometimes they are far away. If you do the math, you can find out a time in the future where they might be at the same place at the same time. For a hypothetical planet 9, imagine being at the track, and trying to see a car on the other side of the ocean. It is vastly, incomprehensively, mind bogglingly far away. IF it exists (there's other explanations for the data that suggest a possible planet 9)."
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jpce32 | How do they deal with dead skin in the air, cough spatter and other small flying things in space stations? | Technology | explainlikeimfive | {
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"They have a fully functional ventilation system just like any office building. More serious then dust is the risk from pockets of stale air which can build up with dangerous gasses. The ISS is first and foremost a research laboratory and does therefore deal with some potentially nasty chemicals. But any gas can cause suffocation even if it is not poisonous. The problem with space stations is that hot air does not rise so you do not get any natural air flow. So the ventilation system have to provide all the air flow and can not miss any spots. This does also collect any dust and other particles in the air. The air vents have filters in them that collects most of it. They do have a regular vacuum cleaner that they use about once a week to clean the vents. There is also regular filter changes to make sure all the dirt gets removed from the filters and that no mold starts to grow on them.",
"Astronaut Terry Virts actually discusses this in his book \"How To Astronaut\". Basically it all gets sucked into the air filters, and one of the routine maintenance tasks is for some lucky astronaut to clean out the filters",
"So there was a video today of one of the astronauts washing her hair. Some of the water went floating off. What do they do about that? Couldn't that get into the electronics and cause problems?",
"They have filtration systems on the air recycling which catch particles in the air like fluff in a vacuum cleaner filter.",
"If I were an astronaut I'd always be terrified of inhaling something in my sleep. Like if a screw or something happened to come loose and was just floating around.",
"HEPA filters. I work at Intel and these are the basis of providing a VERY clean, clean room.",
"Actually not an expert but .... filters. They need a ventilation system or they die. They filter that shit out.... For once it's not rocket science.",
"Major Tim Peake answers some questions like this in the latest \"No Such Thing As A Fish\" podcast =)",
"Major Tim Peake actually discussed this on yesterday’s No Such Thing As A Fish podcast. Because you don’t walk or use your feet as you would on earth, after a few weeks or months in space your feet shed dead skin like crazy. They have suction vents they have to take their socks off next to to catch all the dead skin.",
"Is there a forum or something to ask questions about life on isis?"
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jpgaz0 | why can’t internal combustion engines be “permanently lubricated”, but electric motors can? | Technology | explainlikeimfive | {
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"There is also a lot of soot and corrosive combustion byproducts that get into engine oil, which are prevented from causing engine damage by an \"additive package\" mixed into the oil by the factory. This capacity to sequester contaminants, however, is limited, necessitating periodic oil changes to keep an engine from wearing out prematurely.",
"ICEs continuously burn away their oil as it gets smeared onto the wall of the cylinders and lit up when the piston goes down. There are also so many many MANY moving bits grinding metal dust into the oil. In an electric motor there is only a single enclosed bearing that actually experiences friction. It gets by with a lot less greasing.",
"On top of what everyone else said, electric motors don't have pistons. The pistons allow oil to get into the combustion chamber and combustion byproducts down into the oil.",
"A piston on an ICE has to withstand several high-pressure fuel explosions a second, within tolerances of fractions of millimetres, being propelled away by those explosions at immense speeds, only to rise again just as fast to form a perfect air-tight seal enough to contain the next explosion. It has to do all this at variable speeds, variable size explosions, tens or hundreds of thousands of times a day while at no point EVER allowing part of the metals it's made of to rub even a tiny bit against its container or anything else. Inevitably, the only way to do this is to be completely lubricated, and the explosions burn through the oil leaving carbon and other deposits in it - which means oil filters, oil changes and oil loss over time. An electric motor? It's a coil of copper floating inside an empty space with a bunch of magnets around the edge of it. The only part that contacts AND moves is a small part of a rod that is connected to that coil, that turns when the coil turns, where that rod passes out the motor through a small hole to drive something else. That doesn't even need to be hermetically-sealed. And all the oil has to do it stop the spinning rod - that's rotating and not moving up, down, forward, back, left or right at all - from touching the outer ring. You can literally contain that movement inside a rubberised or lubricated barrier. Exactly the same tech, for example, as in your electric toothbrush (when was the last time you oiled that?), shaver, scalextric cars, your kitchen blender, millions of toys, power tools (some you may have to lubricate but when did you last oil your electric drill?), anything that has an electric motor. Just has bigger, better magnets, that's all. An ICE has gases, explosions, heat, metal expansion, vibration, and large reciprocating vertical motions, all kinds to deal with. An electric motor spins in the air with only the tiniest part of it in contact when the rod is spinning through a hole in the side of the motor housing (and that's mainly just to hold the whole thing steady and away from the magnets). There are none of the challenges of an ICE or even an hermetically-sealed system like an ICE has to be. Imagine installing a hook on a wall, one that only needs to twist around. It can be rotated in a holder to do its job but can't pull out or in - it just spins around. It never has any weight on it. How much would you have to lubricate it for even a lifetime's use, enough that people can twist the hook around but not pull it out or hang anything off it? Just enough so that it doesn't start to wear through the outer casing, basically. Now imagine installing a metal socket instead of a hook into which you expect people to rapidly insert and reinsert a giant lump of metal directly a dozen times a second for hours on end every day for years, and if they're even a fraction of a millimeter out when they push, it's metal-on-metal. You're literally pushing all the oil in or out of your seal all the time. It's much harder. Now imagine the hook can afford to wiggle a bit and doesn't need to worry about air escaping from the other side. But the socket cannot move at all, and there are constant pressurised gas explosions happening on the other side of it all the time. The hook is basically always \"wall temperature\", maybe a little warmer. The socket is going to be operating at hundreds of degrees. The hook doesn't care if the wall wobbles a bit. The socket will angle and the piston will hit the sides if you haven't bolted it down enough, and only the oil will save it and cushion that movement. The hook wouldn't even get dirty. The socket has literal explosions happening inside it all the time dirtying the insides, the join, the oil, and forming layers of detritus inside and outside as the piston moves. It's a very, very, different task. Pistons are feats of engineering honed over decades, centuries. An electric motor is a wire inside a magnet in an empty box. Simpler tech, harder to get lots of power out of it (until recently with high power electrics and extremely strong magnets), but far less requirement for precision engineering and far less friction.",
"Heat is the limiting issue, I’d reckon. Electric motor will heat up a little via friction and lost electrical energy, but it’s not gonna generate nearly what combusting fuel will. Also probably some hand me downs in use coming from car engines. Meaning that say someone made an oil that didn’t start breaking down til 500 degrees, for a combustion engine. So it’s not gonna break down in an engine that only gets to 250.",
"An electric motor is just a bunch of spinning magnets. A combustion engine is a box that's designed to literally explode once every few milliseconds in a controlled way. It's easier to lubricate a chamber of magnets than a chamber of fire.",
"Car engines use journal bearings which are oil flooded to provide cooling and a hydrodynamic wedge of oil supporting the load. These are located inside the engine so they are subject to combustion products and byproducts, i.e they get dirty. Electric motors have sealed for life rolling element bearings located just outside the winding's where it is coolest. Journal bearings are lined with babbit and have a finite lifetime before they need replacement, sealed bearings are actually designed for infinite life, they should never wear out. The gas engine has several to many journal bearings, the electric usually has 2 roller bearings in the motor. HTH",
"Closest you'd get to that is a 2-stroke engine. But in that case the lubricant just happens to be included with the fuel. So it's still not quite that either. In principle it still consumes oil (expendable in this case), but in practice it's one thing not to worry about other than making sure to use already mixed fuel. No filters or oil changes in that regard."
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jppxob | Why are video games with locked frame rates always 30 or 60fps, never in between? | Why are games never locked to, say, 35, 40, 45, 50 or 55fps? It's always 30 or 60. Thanks :) | Technology | explainlikeimfive | {
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"Modern TVs are set up with refresh rates of 30, 60 of 120 fps. Video games that refresh at the same rate as the TV, or in an easy conversion amount, look better, with less chop in the image. If you tried to lock fps to something weird, like 50 fps, then for every second of animation on a 60hz screen, 10 frames would have to be repeated, causing jerky and unnatural animation. But if the animation is locked at 30 fps, then the TV repeats *every* frame, making it seem smoother overall."
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jpqt7x | Why does mineral oil not conduct electricity? | Technology | explainlikeimfive | {
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"Weird news for you: water doesn't conduct electricity either. You just have to use very clean water. What conducts in every material is movable charged particles. In metals that are electrons that aren't as tightly bound to their atoms. In water it's dissolved ions, so all the salts and minerals. Pure water contains no charged particles, and the same is true for pure mineral oil.",
"I am not seeing the real reason so I’ll add mine: water molecules are very polar: when you put salt or other molecules in it, the water pulls those compounds appart into ions. The ions in the water then conduct electricity. As people have said, very pure water with no ions insulates. Mineral oil is made of bigger organic molecules which has a weak polarity. They don’t tend to break things into ions as much and therefore do not cause oil to be conductive.",
"There are three types of electrical properties when dealing with things. Conductors, insulators, or semiconductors. Conductors \"conduct\" electricity, insulators \"insulate\" and semiconductors sometimes conduct electricity, and sometimes dont. The reason why has to do with the structure of atoms and how many electrons it has in its outer valence shell. Mineral oil is an insulator."
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jprd3d | How did Zoom, a company we didnt even hear of till 2020, take the video calling market by storm even though there were many well established services like Skype and Cisco Webex? | Technology | explainlikeimfive | {
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"Zoom was already well known in the corporate world. Its success, IMHO, comes down to ease of use. I can just send a link to anyone with a phone or webcam and we can be chatting in ten seconds. No registration, software downloads, or other barriers.",
"Zoom was already famous in the corporate world. You probably never heard of it because of directed advertisement.",
"I'd say a big part of the reason Zoom took off is because a guest doesn't have to log into any registered account to be part of a conference. When you're running late to a meeting, who has time to authenticate to Google or Skype? And the other products that allows guests, like Webex, have horrific UX that make it a pain in the ass to use. Oh, and Zoom virtual backgrounds are kinda fun!",
"Zoom started to take off in the corporate and higher ed/non-profit areas about 2013-14, my work went to it in early 2016 and by early 2017 everywhere I interviewed at was using it Cisco Webex has some licensing barriers to widespread adaptation and Zoom worked better with mobile and low bandwidth situations than Skype so those are big reasons why Zoom got a foothold. Microsoft's offerings other than Skype have been a mess. Lync had a huge installed footprint - 600-850MB on Windows - then that became Skype for Business Before that Microsoft bought MindAlign and sat on it for 9 years, then retooled it into Teams to become a Slack competitor and now are trying to make it into a Zoom and Slack competitor",
"It's not a new company, it's been around for years. Good UX, no login needed, and it works. Webex is horrifying, and Google changes its products every two years, and they're all unreliable. Plus they require Google accounts. Not much of a surprise.",
"My company has been using Zoom since 2017 and it’s great. Zoom is very easy to use, has good audio/video quality, and they have a free and easy to use browser extension to add zoom meetings to google calendar invites. Skype sucks, requires you to login, and their SSO with other Microsoft products is horrendous. Microsoft Teams isn’t terrible, but almost nobody on those meetings ever uses video, and you cannot schedule meetings using calendar services other than Microsoft products. WebEx is just plain awful. It’s expensive, support sucks, the product doesn’t work well, and it doesn’t have feature parity with Zoom. Honestly it’s awful, I had to use it for a few weeks and it drove me crazy. Also their chrome extension is awful and you can’t use it unless you are a paid user. BlueJeans actually isn’t bad, they just never had market saturation of other products.",
"Skype was already on the way out for Teams. Zoom's user interface is nicer than WebEx. I remember the first time I joined a Zoom meeting and thought \"wow this was so much easier.\" It doesn't have awful dial-in conference bridges. Just click the meeting invite, double-click for full screen, and you're done. Teams was still rolling out and I feel like Microsoft rolled it out early because of the pandemic without refining it. It's slower than Christmas and tries to do way too much. There's no freaking full screen mode when sharing screens, no global way to mute/unmute, the app randomly forgets my accounts and I have to re-associate them, and other little things. Plus it's tied with a corporate license and corporate domain configuration, whereas anyone can host a Zoom meeting.",
"Frictionless experience, no account required, simple intuitive UI and video/audio quality is top notch. We’ve used them for years, everyone else is just playing catch up.",
"And not only Skype and Cisco, but also Microsoft Team, Google Meet and many others. I would really like to find out the answer for this.",
"I've been using Zoom for years. One thing that I haven't seen mentioned here is the voice and video quality. I read an interview with a Zoom executive who said that their main focus was latency. Zoom is much better at keeping the conversation following in almost perfect real time and in keeping voice and video in sync (unless you're using a Bluetooth earbud which may or may not add noticeable delay) than any alternatives. Zoom also does a pretty good job of gracefully degrading the experience when there is a poor connection. Microsoft essentially ruined Skype, and WebEx couldn't take advantage of its first mover advantage.",
"Unlike other platform, Zoom uses open standard where you don't need to have an account to participate which means its like plug and play, not much technical skills needed. This is one of the reasons it has gotten bigger and adopted faster. The downside though is security, meaning people can snoop, watch and record you without you knowing. There are pros and cons.",
"TL:DR - they are not new, just new to mainstream media/attention due to COVID There is a whole IT a industry that has blossomed for 40+ years There is a whole distribution channel behind it Mostly doesn’t go mainstream media because no need to COVID changed that Zoom has been blowing up in IT Channel for quite a while now (I first started reselling them in 2015)",
"Skype was bought by MS. They changed the program and it was unbearable, so people uninstalled it.",
"Zoom wasn't unheard of, it was just unheard of to you. A lot of universities and big businesses were using it already for their online conferencing, it just wasn't big on the individual. I'm sure it just transferred over from that, somehow.",
"A part of it is that I believe they were the first to offer their services free to schools and stuff when the pandemic hit. It made it a household name, almost to the point where “zooming” has reached the colloquial standard for video chatting.",
"Anyone who works in even the most basic tech jobs will have heard of zoom. They have been massively popular for years. Video conference wasn’t really relevant to people outside of the corporate world until this year.",
"The university of Minnesota was already set up with it for several online classes with its built in classroom recording systems apparently.",
"Skype was free, then Microsoft bought it and broke it and it costs money. WebEx costs money, and there are some other difficult license terms. Lync cost money, but then Microsoft bought it and made it more expensive. Zoom is free, and even the \"pro\" plans that cost money don't require authentication for all the non-host people."
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jpw2i4 | How TOR/ onion websites remain anonymous. | How does the TOR network find its IP address or whatever its supposed to connect to, How do these sites hide their actual address and how are we sure that only TOR can decrypt the .onion address. | Technology | explainlikeimfive | {
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"So first let's go over how TOR connects to a known IP address. To connect to a known IP address in the TOR network, a computer picks 3 servers to serve as intermediary nodes. Then, an encrypted tunnel is established between each node in such a way that only the first node knows your ip address. This is done by telling each node only where to route traffic next, not telling them your actual source or destination. The encryption on all the traffic is encrypted like an \"onion\", in the sense that every successive node unencrypts the next layer of the onion. The final node (the exit node) is the only one who can see what the actual unencrypted packet says. But the key to this connection is that no single node knows all of the information. The first node only knows the source ip address, and only the exit node knows the destination ip address and actual unencrypted traffic. In this way, neither the destination or exit node knows what the original ip address is. This is key to understanding how .onion addresses work. When a .onion address is made, the server in question makes an encrypted TOR connection to a TOR node called an \"access point\". Now, we've already established that both the exit node and the access point have no way of knowing the actual ip address of the .onion address. The access point only knows one node to send traffic to: the .onion address's exit node. When you connect to a .onion address, your computer finds an access point for the address in question, and initiates a TOR connection to that access point requesting to connect to that address. Now the magic happens when the access point serves as a proxy to the .onion address. The access point has no idea what the IP for the server is, but it can connect through the TOR connection made by the .onion address, thus connecting establishing a connection between you and the .onion address, while preserving the anonymity of both you and the .onion address. This system is by no means perfect. Compromised TOR nodes and access points can become a real issue. But by routing all traffic between 3 or more nodes, you ensure that just because 1 node has been compromised, you will almost certainly remain anonymous. This goes for both you and the .onion address server. A compromised access point wouldn't mean much as the access point doesn't know the .onion address's actual IP address."
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jpykp2 | How does Microsoft Word autorecover my documents if my laptop crashes? | Technology | explainlikeimfive | {
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"It depends on if the option is turned on and working properly. But what it does is save a copy every few minutes even if you don’t hit save yourself. That’s all it does. Then if the laptop crashes it looks at the place where it saves those temp files and says, hey there’s a document here, the user must have not saved it before so I’ll ask if they want to keep it."
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jq8gdf | why cant the robots read the captcha? | All these websites have the verification captcha to prove that I am not a robot. Why cant robots read that? It doesnt seem that difficult when all these advanced robots are being produced. | Technology | explainlikeimfive | {
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"It's a matter of objects recognition. It's global problem of computer science, and by now we have very slow, time-consuming and partial solutions. Small change in images make them unrecognizable for AI but easy for humans.",
"There's a pretty good chance that a bot can read the CAPTCHA, but CAPTCHAs are more sophisticated than that now. The most advanced ones like [reCAPTCHA v3]( URL_0 ) don't just rely on what your choices are on what parts of the picture have traffic light. While the details are obviously a secret, they look at a number of factors based on your behavior on the website such as what pages you're looking at, how long you spend on them, how quickly you can click the traffic lights, browsing history, etc. (these examples of course are speculative). Then it uses all that information to try to determine whether you're acting like a human. For example, a bot might navigate to a website about dogs from a site that's completely unrelated, have a suspicious IP address, select a link at the bottom of a long page really quickly, and select the traffic lights in the CAPTCHA faster than a human could. The website knows what the typical behavior of legitimate traffic is. For example, maybe a most of the visitors to the website are from Google, Wikipedia, and other major dog related websites, most have IP addresses in English speaking countries, and most people spend 15-45 seconds reading the page before clicking that link on the bottom. The CAPTCHA is probably looking at all the data it can and looking for anomalous behavior with a machine learning algorithm, sort of like how banks monitor credit card activity and flags it when it sees unusual behavior. Your answer to which parts of the image have a traffic light is only part of the process."
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jq9k2t | How the storage on devices is made? | How do the computers, phones, hard drives, USB pen drives, and even cloud drives get storages? How is it produced or manufactured? Why is it in the power of 2s? | Technology | explainlikeimfive | {
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"This is an hard one to reply because the technologies vary wildly between devices. HDD are monumentally different from SSDs, which are relatively more similar to RAMs, but still very different. In short: HDDs store information via magnetisation. As you might know, digital information is encoded as strings of 0s and 1s; you could either magnetise or not a point on a disk, and decide that the former means 1 and then latter means 0. Most other storage technologies rely on transistors. Simplifying *a lot*, a transistor has a state: either it blocks a current or it doesn't, based on this state. So you could try to send a signal through it: if you receive it on the other end, then you decide it means 1. Mind you, this is an overwhelming simplification. Depending on what kind of memory you need, you design it to exploit this behaviour, so you bind this state to the information you're storing. (FYI the term \"state\" is very wrong and I'm using it deliberately for simplicity's sake in this context) Some transistors used in stuff like SSDs are technologically different from the ones used in a processor though, but we'd be digging too deep into the question; just mentioning it.",
"Let's start with the basics: data stored is stored in bits - a bit can have two states: 0 or 1. When you combine these bits, you'll inevitably end with a system that works in the powers of 2's, as you put it. Now, why 0 or 1? Because its the easiest way to express data through magnetic or electrical charge. This is where the material used in storage comes in: you can use magnetic disks, that retain a positive or negative charge over a long time, to store sequences of 1's and 0's. This can also be done with circuits that keep a charge, same principle. Okay so how does that become a hdd, for example? Well, hard disk drives are relatively primitive, essentially its multiple disks of that magnetic material stacked over another, with a motor attached to spin them and an arm with a sensor on it for ever disk, swinging over it to read the disk - its as mechanical as it gets. But how did we compress that tech into usb-sticks? We took the mechanical component and made it digital: microscopic transistors that can hold a charge, even when no power us applied, are used to simulate what the hdd does via its magnetic disks. Bonus fact: thats why these solid state drives are faster than any hdd - there's no physical step in the process of reading storage. I hope this answers your questions somewhat."
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jqabxz | How do they make fireworks that assume a specific shape when they go off? | Technology | explainlikeimfive | {
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"Shapes like a circle are easy. You place small charges with delayed fuses around a bigger charge that blows them away from the center point equally in all directions. Shapes like a heart or other more complex ones need the central \"spreader\" charge to be specially shaped or have some sort of interference so that the smaller delayed charges that makes the shape are the right distance away from the center when the pop."
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jqcwcg | How does force reboot simulate disconnecting the battery in a smartphone with an unremovable battery? | My android phone wouldn't turn on until I force rebooted it. Is force rebooting the same as the old school method of removing the battery (a regrettably rare feature these days)? If so, how can an electricity-reliant device's software simulate a battery removal without actually cutting the power? | Technology | explainlikeimfive | {
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"One part of the system, close to the battery, cuts off power to the rest of the system, but retains power to itself."
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jqhqyv | What is special about ARM computer processing? | I keep hearing about the new Macs with ARM processors, as opposed to x86. I don’t understand what either of those mean. | Technology | explainlikeimfive | {
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"Processor architecture means the way the processor carries out instructions. x86 is designed to be able to do a bunch of specific complex instructions and ARM is designed to do a limited group of very simple instructions. But a long time ago people realized that there's no limit to what complex things we'll want to add to the list of automatic complex instructions, and that every complex instructions added to the architecture slows down its ability to do ANY instruction. But you can also do any complex instruction by breaking it down into very simple instructions. These things put together mean that the more complex things you want to do with a computer, the faster it will be able to do those things if you just build them out of many simple instructions rather than fewer complex instructions. The problem is, computers were already mostly using x86 when people realized that, so for a couple decades we've been using the less efficient system just because it's what everyone uses and the companies that make processors don't want to have to change. It's like if you're drawing. It's easy to make straight lines, and triangles, and circles, and squares. And with those shapes, you can draw literally anything else. But if someone gave you a magic pencil that could automatically draw a face, drawing faces would be SO much easier. But if it can only draw the same face then you either have to settle for the fact that all the people you draw will always have the same face, or you'll only be able to automatically draw one face and still have to do the rest by hand any time you draw a group of people. And it'll be completely useless any time you draw a bridge. But if you have a pencil that automatically draws basic shapes, drawing ANYTHING becomes a lot easier.",
"There are a variety of differences between ARM processors and traditional x86 processors - if you'd like to get into the technical differences, there's lots of articles that discuss it if you search the web. At a high/simple level, ARM and x86 processors have different instruction sets. ARM processors focus on efficiency - if the processor is going to process some data, let's process it as efficiently as possible from a power/electricity consumption perspective. x86 processors focus on performance - if the processor is going to process some data, let's process it as quickly as possible no matter the power/electricity consumption. This makes ARM processors ideal for applications where power is limited, such as battery operated devices (IE. cellphones and laptops, or even high performance rigs where power consumption is extremely high and may need to be reduced as much as possible). x86 processors are ideal for applications where power efficiency is less important, like a desktop computer.",
"Just a different type of chip. A different set of instructions, with different capabilities and different timing. They're all pretty equivalent in the long run, but ARM is built to be made of lots of small, simple instructions (\"Add this to this\") whereas x86 is more built towards more complex instructions (\"Apply the mathematical function to this matrix of numbers\"). It's like deciding what language they talk - you can talk \"simple baby language very fast\" or \"adult language where one word has a lots of implications and so may take some time to comply with completely\". In the end, both types of architecture have advantages and disadvantages and there's no clear winner. They are both produced in their billions worldwide. But with ARM in particular, just because of its history and its focus on how the chips are designed, the way it's held the market is that their chips are powerful, simple and also extremely low power consumption for that job. x86 chips are one of the highest power-consuming chips. ARM originally powered something called an Acorn machine, from the 80's. They've been around that long. And they now power virtually every smartphone in the entire world (yes, including Apple). The problem is that speaking ARM and speaking x86 are two very different things. Of course you can describe any particular task in either language, but everything that's only been written in x86 needs to be \"translated\" to ARM to make it work properly, and vice-versa. Most modern commercial desktop operating systems are x86. But most phone and tablet operating systems are ARM. Hell, even Windows running on ARM is nothing new. Fact is, that an ARM can do just as much, and everything that an x86 is capable of. It will likely use less power to do so (great for phones and tablets and laptops, not so important for a desktop computer). But most of your games / Windows applications are written in x86. That doesn't mean they couldn't be translated, but it's not just as simple as \"run them through Google Translate\". The creator of the program has to be willing to translate the program as only they have access to the \"original text\" (source code), and not everybody will bother.",
"You may think of ARM vs x86 as being similar to the difference between programming languages like C++ or Python but in this case, it is the hardware language rather than a software language. The significance of this change is that Apple will jump ahead in the laptop market at a minimum and who knows what they will do with a desktop computer. ARM is known for having low power consumption with good performance and apple has been making the best mobile processors you can get for a while now by using ARM. Until this change, they have only used these mobile processors in their phones and tablets. Now they will bring this incredible efficiency to their laptops. You can expect a large boost in battery life and the devices will probably get even smaller as they may no longer need cooling.",
"So you know how computers have a little chip in them called a processor. If you send specific electrical signals to the pins of this chip, it will perform certain basic operations like arithmetic, comparing numbers, storing or retrieving numbers from memory etc. And this is how we can get computers to do things useful for us humans. Of course you need to know what specific signals will perform which instructions, this is called the instruction set, it's like the digital \"language\" that the processor speaks. ARM and x86 are two of the most popular instruction sets. As for what's special about ARM, well, nothing really. x86 is a type of Complex Instruction Set Computer (CISC), meaning it can handle complex operations with dedicated instructions. ARM is a type of Reduced Instruction Set Computer (RISC), meaning it has fewer instructions available, but can perform them more efficiently. Neither is \"special\", they are just two different approaches to achieving the same goals. The line between the two gets fuzzier each generation, and each approach has trade-offs. As an analogy: A truck and a motorbike are both popular means of transport, a motorbike will take less fuel to reach your destination faster, but good luck using it to move furniture."
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jqo0br | how do snipers account for the clitoris effect, air resistance, and wind all at the same time? | Technology | explainlikeimfive | {
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"I believe you mean the Coriolis effect (and if that was an auto-correct error it's a pretty great one). The short answer to your question is: you can account for any known variables where you understand what the variable changes. If the Coriolis effect, air resistance, and wind create A, B, and C changes like a drift of X inches and a drop of Y inches, you can stack that information up and make an adjustment. As long as you have the knowledge/data and a tool you can adjust, you can adjust for those variables.",
"I am going to assume that clitoris is autocorrect of Coriolis. The answer to your question is math, experience, practice, and in some cases computer assistance. The CheyTac Intervention at least comes with multiple computerized accessories for extreme range shooting to assist with all of these things.",
"Snipers rarely go out alone they have a guy next to them helping with the ranging and calculations. They have charts detailing different bullet drops with distance, weather, etc. They use clues from the surroundings to understand the environments that the bullet will pass through; a bag blowing down the street, leaves of trees, dust kicked up. There are an enormous amount of variables and it's an extremely skilled job that is more than just aiming.",
"I believe the word you're looking for is coriolis, and the answer is that they calculate the effects based on the knowledge and experience from practice. Surprisingly it's even more complicated than you think, since there are a TON of variables that affect bullet travel. Everything from humidity, air temperature, barometric pressure, altitude, the difference in wind speeds all along the trajectory of the bullet. . . All of this can be accounted for, it just takes time and an experienced eye.",
"While this was not covered in my marksmanship course, I can say with confidence that the clitoris is essential to the wellbeing of many military personnel. An extreme LONC can increase aggressive decision making but impede the calm required for precision marksmanship, so removing LONC is a primary P5 goal. LONC = Lack Of Nookie Condition P5 = proper planning prevents piss poor performance",
"The clitoris affects all of us. Hero’s know how to get passed the clitoris and do their jobs"
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jqp12a | How are programmers able to manipulate electricity to produce images on a screen? | Technology | explainlikeimfive | {
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"Greatly simplified, each pixel is just a little group of lights that are either red, green, or blue, and can be switched on and off quickly to mimic different brightness levels. When blended together at varying brightness those 3 colors make all the rest of the colors. Put all those pixels together in a grid if vertical columns and horizontal rows and you can assign each one an address. The image is created by telling specific addresses to light up specific colors at specific intervals to create specific colors. It’s pretty magical how far we’ve taken the capabilities of the LED.",
"Most programmers typically do not address individual pixels. They use graphic utilities and libraries to draw and color and move lines and pixel groups. A few low-level programmers had previously set up the utilities using x-y coordinates to address specific pixels, then program math formulas create the rest of the graphic utilities. For example, add 1 to X to move one pixel right. The math gets fairly complicated when drawing, shading, and rotating 3-D objects, but again, it was all pre-programmed. Everybody else builds on graphic libraries as a starting point."
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jqpesb | Can a graphics card be used as a computer on its own? | Hypothetically if you had the skills and knowledge to hack into a graphics card, would it be possible to reprogram the GPU to do tasks a normal cpu would be able to do with no external data being sent to it? Like you just plug it into power and it does stuff. Even with limited functionality would you be able to program software or even run a game on it? Like it has the basic things a computer would need: a processor and ram. Would there be a way to connect storage to the bottom pcie connector? Sorry if this sounds dumb I'm really curious if it's even close to possible | Technology | explainlikeimfive | {
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"Wholly on it’s own, not really, the GPU doesn’t really have anything that can keep data after you turn off the power, plus it sucks at a lot of the math not related to graphics. That being said, a lot of the math related to graphics can be applied to other things. And people do use their GPUs for a lot of other stuff. It works great for a lot of database and big data things. They call this General-Purpose GPU computing. URL_0"
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jr0qxk | Laundry. Do you really need to sort clothes? Does fabric softener do anything? What are things our parents taught us about laundry that don't matter with current washing machines? | Technology | explainlikeimfive | {
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"Not gonna comment on washing, but for love of no starting a fire, clean off the dryer lint catcher every single time!",
"You don’t NEED to sort laundry, but you can if you prefer. You don’t NEED to use fabric softener, but you can if you prefer. Cold washes are perfectly fine for most laundry. Do a hot wash of towels every few months to freshen them up and clean the washing machine. Washing brand new clothes, sheets and towels with plain table salt (with no laundry detergent) will neutralise any chemicals left over from manufacturing and will help lock in colours. You don’t need to use the full amount of laundry detergent that the detergent manufacturer recommends, you generally only need a third or half the amount. Line dry when possible",
"You probably should sort you clothes, yes. Some dark colors can bleed and stain whites (red is particularly bad) so having light/dark loads is good practice. Some garments can't tolerate strong agitation (like lace or very fine cotton) so they should be washed on a delicate cycle. Others can't tolerate hot water (like fine wool) so they should be washed on cool. Drying in the machine has similar restrictions - some items tolerate hot tumble drying, others do not (they might shrink). Every garment should have a tag that tells you how best to wash it, and for the most part you should follow it. As for fabric softener, it is somewhat helpful but not necessary. It's an effective way to keep fabrics soft and wrinkle-free. It also helps reduce friction between fibers, which creates less static cling and helps product your clothes from wear and tear, making them last longer than if you were to go without. Not all fabrics respond well to fabric softener, though, and some skin may be sensitive to it. I _personally_ don't use it, but if you choose to, use it sparingly.",
"This comment just reminds me of my floormate in college. He was doing his own laundry for the first time. We told him to sort it first, so he made a pile of pants and shirts. It’s amazing what skills parents will send their kids out into the world without."
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jr2ue7 | If dogfighting doesn't really happen anymore, why do Air Superiority Fighters still have canons? What are they for? | Technology | explainlikeimfive | {
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"They said thr age of dogfighting was over after missiles were invented. In fact, the US was so sure if this that they made the F-4 Phantom without a gun. Then Vietnam happened. There it was discovered that missiles aren’t as reliable or a sure thing as originally thought and F-4’s were finding themselves out of missiles and without a gun facing MiG’s that still had a gun. It didn’t go well for the F-4. That is a mistake that won’t be made again. Plus, guns are useful for strafing ground targets and there aren’t any pure air superiority fighters anymore. Even the F-22 has ground attack capability.",
"The US learned this lesson the hard way. You want to be able to dogfight and have a gun for that unlikely scenario where your missiles don't work. The F-4 Phantoms did abysmally at the beginning of the Vietnam war because missiles weren't reliable enough and pilots didn't have the skills or weapons to dogfight if needed. Missiles have improved a lot since then but countermeasures have tried to keep up with jamming and stealth systems which negates a lot of missile improvements. You don't want to find out that the SU-57 has wayyyyy better stealth systems than anticipated such that your F-22 can't engage it with long range missiles, have to enter a dogfight, and not have the guns to take on the enemy or the skills to get on his tail to use a heatseeker. There are a lot of bits that seem completely useless but are there just in case you have an \"Oh SHIT!\" moment. There's a switch on the F-15 which spins up the turbine a little bit more to give about 2% more thrust but will completely wreck the engine after a few minutes. Why would you build a feature that can ruin your expensive jet engine? Because not having that feature could cost you entire airframes but that 2% could mean that some planes can escape from a losing fight. Similarly the gun takes up space but could *maybe someday* save an F-22 in a dogfight."
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jr669u | What is Right-to-Repair and how does it impact the average person? | Technology | explainlikeimfive | {
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"Im no expert on your country’s legislation but the idea is that owners of a device should be able to repair the device they bought. So there should be no artificial block in place purely to stop that. It was created to stop tech companies from artificially preventing user repair to get themselves a monopoly on the repair of the devices. In modern days it has become more applicable to independent repair shops than the individual user since modern electronics have become so complex.",
"You ever have a home printer? You ever run out of red ink and then have the printer refuse to print a black and white page even though you had plenty of black ink, or refuse to scan something because it was out of ink (not copy - SCAN)? Well imagine your car worked like that. Imagine that your car told you that your headlight was close to the end of its life and you have to take it to the dealership to get it replaced. Or that the battery you were using wasn't \"certified by Ford\" and thus your car wouldn't shift out of Park. Imagine your fridge wouldn't make ice or dispense water until you bought a three hundred dollar \"filter\" from the manufacturer, and you had to do that every 9 months. Imagine your Sony smart TV downloaded a software update one day and then Netflix wouldn't work on it - but the Sony Movie Store would. If that pisses you off then ask yourself how it is any different from your cell phone battery crapping out after 2 years and you not being able to replace it. Or from your phone downloading an update that makes everything worse on it. Or from your coffee maker requiring special cups to work sold only by the manufacturer. You put up with a lot of shit in \"new\" technologies that you wouldn't tollerate for a hot second in older ones. Well Ford, and Sony, and Maytag are watching. They are not stupid. And if you don't push back on Apple being dicks about battery replacements and screen fixes and software updates then before too long you can expect everything you own to be tied to some kind of subscription where you are paying hundreds of dollars a month just to keep the shit you own working the way it should work.",
"There's been this move away from repairing stuff to just replacing them when they break. And manufacturers have gotten really good at planning out when things will break. It's essentially forcing people to buy new. It's wasteful, polluting, and can be more expensive. Part of this trend includes companies making it harder to repair their products. Like no longer publishing repair manuals for cars, gluing (or riveting) parts together instead of screws or clips in phones. Limiting the ability to repair only to those shops the company has blessed. There's a movement to reverse that by regulating companies to share what information they have about how to repair it their stuff, and a general expansion of consumer protection. [Louis Rossmann]( URL_0 ) has a lot to say about it as he runs a phone repair company. Short version: Apple is tyrannical. For the average person, it means they can keep their stuff running for longer and cheaper because anyone can repair it."
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jr78p5 | Why do HD videos stream flawlessly on Netflix and other OTT platforms but not on Porn Sites? | Technology | explainlikeimfive | {
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"Netflix, and many other large streaming services, have CDNs (content delivery nodes) within the infrastructure of most ISPs. So when you're connecting to Netflix, you're not really going out \"across the internet,\" you're generally just connecting to a server that is within your ISP at the nearest local major city node. Most porn sites do not have that kind of setup, you have to go across the internet to their site, or at least a little further to whatever cloud provider they may be running on."
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jr8l65 | How does the start/stop feature in newer cars save fuel and not just wear out the starter? | Technology | explainlikeimfive | {
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"The simple answer is that the starter motors are specifically designed for that purpose. Engineers design them with different bearings, brushes and gear ratios so that they are better suited to the task. Starting a warm engine is also less strain on a starter than a cold engine.",
"Some systems use a [combustion starter]( URL_0 ) instead of a mechanical or electrical starter. In this system the piston is stopped in the ideal position so that the fuel/air mixture can be ignited to start the engine.",
"Depends on how the system is implemented, for fast retrofits, they indeed use a beefed up starter to handle the frequent use, however, a warm engine takes less work to start than a cold one, and less fuel to do so. Other methods have a big flywheel style motor to do the starting, such as hondas hybrids, so there is no extra wear on the regular starter. Finally, another way it is done, is by using the alternator which in itself is made specifically for this task with a strengthened belt drive to acheive start. As an alternator is just a regular electric motor when fed current than giving it back.",
"A question in my wheelhouse and seeing misleading answers below; > **How does the start/stop feature in newer cars save fuel** It's really as simple as they save fuel by taking the small amounts of time when at stop signs and stop lights to turn off the engine thereby saving fuel. These small moments add up to for the average driver savings \\~5% on fuel .. and most importantly to the vehicle manufactures, increases their MPG numbers in the cheapest possible way (vs other R & D) to meet ever stricter CAFE standards. It really is not for your direct benefit and I personally am annoyed by it in every implementation I've seen and driven. > **and not just wear out the starter?** Modern starters (brushless) are much more efficient and more powerful than older (brushed) starters. Where a brushed starter is good for \\~3000 hours, a brushless can go \\~30000. So while sure stop/start increases utilization on the starter it's up for the job all things considered. The real wear issue for this tech is on the vehicle Battery. Batteries are not proficient at the increased cranking throughout the day and the increased load when 'stopped' and still supporting your fans blasting, radio and headlights on, and back to cranking again. Battery makers are still trying to come up with different construction techniques to minimize the impact of being in a near-constant state of partial discharge. So what you will find is batteries for these vehicles are more expensive and have to be replaced more often in the typical 3-5yr lifespan.",
"It does wear out the starter, that's why they give you the option to disable that feature. They do say that they designed a starter that can be started that often. But really, the feature is for saving fuel. The government requires manufacturers to meet certain average fuel economy guidelines, and by installing the start/stop, that is how the manufacturer can get average economy up (or average emissions down) even if some people disable it.",
"Some cars do it by positioning the cylinder just before detonation and then firing the spark plug to get the engine going.",
"Let’s not forget it’s also a cheaper way to get around the mpg standards that were enacted. Cheaper and easier to make a durable starter motor vs a more fuel efficient drive motor.",
"Others answered the question well enough, but I want to note one major disadvantage of start/stop systems. While the starters are up to the task, any time an engine is started, is the point of maximal wear. All modern car engines run on plain bearings which require oil pressure to work properly. Once there is enough oil pressure, the shaft runs on an oil film and has no contact/rubbing on the plain bearing. The only time it does not have the oil pressure, is during startup when the pump isn't spinning yet. If a normal car starts up once for one trip, and a start/stop car starts up 10 times, that is a big difference. Engines generally aren't made differently on cars equipped with it or not. On the long term, I am sceptical whether saving that minimal amount of fuel at idle engine speed outweighs the environmental impact of a car with worn out crank bearings (which usually meant it is just discarded). But this does not matter to manufacturers, all they aim for is getting to those legal emission limits for new cars... If you use a car for 10 years instead of 5 years, it is way more ecological than a start stop system, because it means one less car had to be produced.",
"They have electronic starters (two starters) stopping the motor running for even a short period of time reduces emissions.",
"I had it enabled for a whole year and I saved about 400ml (the subi I had tells you) I use it in my VW now just at red lights cos it goes so quiet and still",
"To add to everything that was said, your ECU knows exactly where you are in the combustion cycle, so if it uses the starter to crank the engine (instead of alternator/hybrid/etc system), all it'll take is a 90⁰ turn of the crankshaft to spark and start",
"This is about the fuel savings part. If your car is idling for more than 7-ish seconds, it is beneficial to turn the car off. Of course it depends on the car so it's a rough number. URL_0",
"If this is done to reduce fuel consumption and emissions, then why do all of the cars that I've been in that do this idle indefinitely once they've been put into Park? I suspect it's because the EPA doesn't rate fuel economy or emissions when a car is in park, but I'd love to better understand this. Seems totally nonsensical to me.",
"The thing is - it does wear out the starter. I\\`ve read on car forums that there had been chats with car makers and they aknowledged that start/stop wears out the engine faster. The fuel economy is also pretty low since engine consumes low amount of fuel while car is standing. From what i see this feature is mostly made for ecological purposes."
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jr9qf5 | - Why do elevator floor numbers change faster than the elevator travels? | Technology | explainlikeimfive | {
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"Because the display goes at a constant rate, while the actual travel of the elevator starts with slow acceleration and eventually reaching full speed, then again slowly decelerating at the end, to reduce the amount of jerk felt by passengers. There is no need to complicate the display by also having it do the same thing."
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jrfvut | how does a TV remote control when a television turns on and off? | Technology | explainlikeimfive | {
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"Aim your phone camera at it, specifically the shiny black part at the front. You'll see a purple dot glowing there. That's a very near infrared LED light. Just outside of human vision, but within the range of your camera. Purple because it causes the red and blue sensors on your camera to react. Not intentional or anything, but we just don't care about about this near IR light so let it do whatever. At least not with cheap cameras, good ones have a filter so this doesn't get in and slightly distort colours. If you don't see it on your phone camera, you have some fancy phone with an expensive camera that has this filter. Anyways, you'll note it flashes when you hit buttons. That's literally it. Just some Morse code (sort of, not literally the same patterns) flashes to your TV. A camera like sensor on your TV that is always on watches, and turns the rest of the TV on when it sees the right flashing code. A visible LED would work as well, but would annoy people with the flashing. This also explains why you don't need to point directly at the TV to make it work, but if you point the opposite way or completely block the remote it fails to work. It's not radio waves, doesn't go through things. It's more like a flashlight that just need enough of the beam to hit the TV. Also explains why you can bank it off a mirror or window while facing the wrong way. As well why sunlight sometimes interferes and makes it so you have to point very precisely at the TV and might need multiple tries, while it's very reliable at night."
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jrl2jg | Why personal computers mostly use graphical user interfaces and mainframe/servers & supercomputers are mostly controlled through command/text line? | I know why PCs use GUI that is interactive for personal usage but for the sake of making a complete el5 question for others, I've included it. | Technology | explainlikeimfive | {
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"People who use the latter category are mainly IT professionals and computer scientists who a) may not need the more user-friendly interface, which saves development costs, and b) might actually be restricted by a GUI. Pure command line interfaces give the user complete control of whatever the program in question is capable of, generally speaking. E: the resource cost of running a GUI may also matter, as another comment says, especially when you're in the business of optimizing algorithms.",
"A command line interface is much more powerful than a GUI. Modern interfaces are not just one line at a time, they are scripting languages as well. Bash is popular in Linux, Powershell is popular on Windows. You can interact with both as a simple command line, or write scripts for them. I used a Powershell script to make sure a file was being automatically updated, and if it wasn't the script restarted the process responsible for editing the file. This would be very difficult to setup with a GUI.",
"For simplicity. A personal computer is meant to be easily accessible and intuitive for a human to use for a variety of reasons. A GUI is ideal for this, since it allows the most flexibility and ease of use. A server or supercomputer has a very specific set of uses, whether it be running a single group of programs or executing specific calculations, and a user of such a computer would likely be very skilled. Therefore, a command line interface for inputting and executing discrete instructions and calculations makes the most sense in that application. In addition, by not having a GUI, less system resources are devoted to the interface and can be used for computation.",
"1. You mostly operate servers through SSH. Nobody is gonna scoop up a spare monitor, mouse and keyboard and walk through a datacenter to the machine in question, then start rooting around for a VGA port, unless the server in question is so FUBAR that it doesn't even get to starting its SSH server. SSH is a text based console, although with some acrobatics it can sorta-transfer a GUI (though it is sucky and only to be used if there is no alternative). 2. If you aren't using SSH you are using a web interface for the same reason. In that case it's sufficient that YOUR PC has a GUI to show it. 3. GUI interfaces hide a lot of functionality from you that goes beyond just user friendlyness. The things you can do with a GUI and things you can do in a CLI compare to each other like [this]( URL_0 ).",
"GUI's take up resources to run and don't really add any benefit to a server. In addition, a lot of what people want to do with servers, they want to automate it. You can't really automate clicking around a GUI very well. Thus, most server components are completely controllable via command line as a result.",
"GUIs are very discoverable, that is, if you don't know something you can leverage common design tropes to potentially go find it, or at least have someone explain to you where it is in spatial terms (which people are naturally good at using). CLIs have poor discoverability, but once you know how to do a thing, you can do it far, far faster. There are multiple contributing factors to why CLIs are faster: * They can utilize all 10 fingers, instead of merely 1 or 2 on the mouse / touchscreen. * They are controlled absolutely, so you don't need to think about where you are in order to begin expressing what you want to do. (this is also why GUIs that target power users have lots of hotkeys) * You can define \"shortcuts\" (aliases) that greatly reduce the amount of typing without contributing to visual clutter. So in short, GUIs are suitable for people who might not know what they're trying to do or how to do it, whereas CLIs are ideal for people who do know exactly what they want.",
"Complexs graphical interfaces need more ressources, and when you need to allocate every ressource available for a precise task, you can't really waste any for a gui. You could totally use a gui on a supercomputer, you just don't need to and it'll be a watse"
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jrlxrw | Why is it so hard to add Ray tracing to games? | For example, games like Fortnite, Satisfactory, and Sea of Thieves. What challenges are they facing? | Technology | explainlikeimfive | {
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"Ray tracing is a method of projecting a vector (direction and magnitude [length, distance, w/e you want to call it]) into a direction until it \"hits\" or \"collides\" with another object which then we use some math to reflect the \"ray\" back in some direction. These engines have the ability to ray trace as it is a non trivial function. The difference is \"how many\" rays can you draw at one given time for a given object. Each ray is a performance hit regardless of how small, if you draw enough rays you can get the detail you want on a object but at what performance cost."
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jrm9ht | how secure telephones work | How do secure telephone and connections work as when described by military personal onboard AF1 for example. | Technology | explainlikeimfive | {
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"Imagine you want to securely talk to a friend, and say you know another friend that talks a language not native to your location, and the friend you want to talk to also knows someone talking this language. So you tell the translator what you want your friend to hear, and then he says it to the other translator who translates it back to english for him. That's basically how encryption works. The US even used this in wartime before computer encryption was viable. It basically makes the message impossible to understand, unless you know the language (or key, as computers use)",
"Within a single building like the Pentagon, the secure phones work pretty much the same as any office phone system. The difference happens between buildings, or for a phone that works on Plain old Telephone Service (POTS) lines that may be installed at a senior person's house. Between buildings like, CIA calling into the Pentagon, the government has their own private networks. In order to prevent someone finding where these networks are and listening in, each building will have a system where the network enters / leaves the building that 1) converts the phone data to digital signals, if it wasn't already. and 2) applies encryption to the digital data. The encryption is similar to running a VPN between your home and office, except specific hardware and processes are used to ensure the encryption meets security standards. If you hear someone ask \"Is this a secure line\" or mention \"going secure\" in a movie, they are using a specially made phone that can call over commercial phone lines. The phones can dial directly to each other as well, which is where the people talking would make that distinction, but they would not talk for a while and then \"go secure\" that would be the first thing done before having any conversation. To talk between those phones and a building system, there is a phone bank in the buildings that you call in to, after the phone bank answers, the phone on commercial lines is set to secure, then you can dial a number on the secure system. Dialing out is similar, you call to the phone bank, give it the external number, and it plays a recording stating to \"complete the connection\" or something else that gives enough instruction to the person being called, but does not state the purpose if it's a wrong number. The person with the phone can make the phone secure and then they can communicate."
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jrnypu | How does cryptocurrency work, more specifically how do you “mine” cryptocurrency and where does it come from if it’s all digital | Technology | explainlikeimfive | {
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"In a simplified sense: To spend \"coins\", you broadcast a message to the network, specifying that you want the output of a previous transaction to be sent to [public key of recipient(s), aka an address], signed with the private key of the address the coins were previously sent to (proving ownership) That message is received by miners, who include a bunch of transaction messages, add a small random value, and run a cryptographic hash function and hope the output value is below a certain target value. If it isn't, the process is repeated. (This process is often done with graphics cards or specialized application specific integrated circuits to execute many times in parallel). If someone does create a bundle of transactions with a hash value below the target, that bundle is considered a valid block, and if that block is referenced in future blocks, it's considered part of the chain of blocks representing the transaction history of the currency. The entity that successfully computed that block specifies an address to send a reward transaction to (composing of all transactions fees of that block, plus an award amount) (The size of the amount of the data in any given block has a maximum limit, and transaction fees acts as a mechanism to provide an incentive for miners to include your transaction over others.)",
"Cryptocurrency is just a fancy ledger of who sent money to who. What makes it \"crypto\" is that, on a regular basis, the ledger gets \"sealed\" so that nobody can try and retroactively change anything. To first understand sealing the ledger, we need to understand hash algorithms. Essentially, a hash algorithm takes a piece of data (of any size) and produces a fancy checksum of it. The three important traits that this checksum has (as far as cryptocurrency is concerned) are that it has an avalanche effect on any changes on the input data (i.e., small change in data = big change in results), that it takes a non-zero amount of time to calculate, and that it is a one-way algorithm. To seal a ledger, what needs to be done is add some extra padding so that, when the ledger is hashed, the value of the hash ends with a certain amount of 0s. All that you can do is guess padding values and calculate the hash, so it is a very CPU intensive operation. The amount of 0s that are needed can be adjusted depending on how many people are participating so that you can expect a seal every ~10 minutes or so. Whoever actually seals the ledger gets some amount of of the cryptocurrency (out of thin air) for their troubles. This is what is known as mining. Now let's quickly address a couple of the problems with cryptocurrency. First, there is constantly new currency being added, so it will be subject to inflation. The only counter to this is people losing their crypto wallets, so money just poofs out of existence. Second, the amount of electricity needed to calculate these hashes is absolutely insane. A couple years ago there was a paper trying to predict the cost of Bitcoin. In it, they figured that every single transaction done with Bitcoin requires about 10 cents worth of electricity to process. That's about the same as leaving an LED light bulb on for 5 days straight."
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jroito | Why replacing 2 of the batteries won't give a toy 2/3 battery life. | So my kids toy backhoe ran out of battery and I only had 2 spair batteries with me while the backhoe needed 3. I put in the 2 and it didn't work. So I went and got a 3rd battery and it works fine now. ELI5, why replacing 2 of the 3 doesn't work. I would think that it would just bring the toy to 2/3 of a full battery. | Technology | explainlikeimfive | {
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"Electricity has 2 major measurements: the voltage which is like the \"pressure\" in a hose, and the current which is like the \"flow\" in a hose. When you multiply these two numbers together you get the power consumed by the device (in watts). Each battery can provide so much voltage and so much current, and putting multiple batteries together lets you increase these numbers depending on how you connect them. Usually batteries are arranged so that you get more voltage, but the same amount of current. So with 3 batteries you get 3 times the voltage. However as a battery runs out both its voltage and current capabilities go with it. When you replace 2 batteries the 3rd weak one is still limiting the current it can offer. So you're not getting nearly the amount of power that you think you are.",
"If the three batteries are in series, that’s 1.5 x 3 = 4.5 volts. As the cells deplete their energy the voltage drops until the device is unusable. usually less than 1.35 V Now adding two new cells gives (1.5 + 1.5 + < 1.35) is less than 4.35 V Unless you measured the voltage of that last cell there’s no way to know the voltage there, but the two new cells plus the old one didn’t have the voltage necessary to run the device."
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jrs0wn | In Task Manager (or Activity Monitor on Mac), how does it close a program differently, whether I pick "end" or "end now"/force close? | Technology | explainlikeimfive | {
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"One is asking a worker to finish what they are doing, clean up their desk and go home, the other is taking out a gun and shooting a worker in the head. The latter makes them stop really quick, but leaves quite a mess. The former is dependent on them actually listening to your request and not being so buys with their work that they will ignore you. You normally only want to shoot the worker if he won't listen to avoid the mess.",
"There are different levels of \"Stop\" that you can send to an application, and the application can handle them differently. For instance, when you're shutting down your computer, it sends a nice \"Please close\" command to all your open applications, and they can intercept that command and give you something like a save prompt. However, sometimes the application can't finish the nice hangup procedure due to whatever reason you're trying to force it closed. When you do a force stop, that sends a special level of signal that programs aren't allowed to catch. They just get removed from existence and aren't capable of stopping it from happening.",
"We can picture your computer like a bar, where all the running processes are like customers. If you need to ask any of your customers to leave, you have two options. A) Ask them politely to go home (End). They'll probably do a few things before heading out -- say goodbye to all their mates (close open connections with other processes), finish their drink (wrap up the last running task), and pay their tab (release resorces like memory). This is the optimal arrangement. B) Kick them out (Force End). If they are drunk off their ass (frozen), or otherwised pissed off and threatening violence (malware refusing to close), you can call the cops (the operating system) to force them out. It should be a last resort way to do this, as you may leave the state of your bar a mess requiring cleanup afterwards."
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jrvgoa | Why is there only one internet and not multiple? | Technology | explainlikeimfive | {
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"There are many, many mini-internets. However, if you connect one to the main internet, then you lose nothing and now you have access to way more information from your network. As such, most people choose to connect their 'micronet' home networks to the internet.",
"\"Internet\" refers to the protocols of connectivity, not to any one specific *thing*, per se. There are many computers that are all connected through *the internet*. Within that there are billions of different servers, but they're all connected via a standard method of networking. It's like how you're made up of billions of cells, and yet you are one person. The amount of cells and what they're doing is constantly changing, but because \"person\", like \"internet\", refers to a kind of average pattern, we say you are \"one person\", just as there is \"one internet\". Though, there *are* different layers to it, you've probably heard of the \"darkweb\"? That is, in a sense, a \"separate internet\", but even that is still a part of *the* internet."
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jrx3pb | How do hospitals calibrate their testing devices? | Title, for example blood test machines... O2 level monitors... ekgs even. | Technology | explainlikeimfive | {
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"There are a ton of calibration service companies, and the manufacturer as well. Equipment calibration is a very large business.",
"I work in a hospital lab so calibration is part of my daily routine! We do QC (quality control, what you're calling calibration) every morning before we start testing blood. Basically, we can order QC material from the manufacturer or from a 3rd party, and it will have a known/fixed amount of all the stuff you're testing. For example, we test blood for glucose, sodium, etc. So our QC material will be a blood-like liquid with a fixed amount of glucose, sodium, etc. If the company tells us that the QC material has 130 units of sodium in it and our analyzer thinks it has 110, we know that we need to recalibrate. If the analyzer thinks it has 130, we know that we're spot-on and the bloodwork we run that day will be accurate. We do that for every single compound we test for: glucose, electrolytes, hormones, everything gets QC'd every single day. We also do it for microbiology testing: for that it's a bit different. Say we run COVID testing, we'll QC using a positive control and a negative control. The positive control contains inactivated COVID so the analyzer should read \"positive,\" while the negative control contains no COVID at all so we know the analyzer should read \"negative.\" QC/calibration is so important that many larger hospital labs will have a team of people whose *entire job* it is to make sure QC/cals are looking good."
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jrxkih | please - Why do high speed cameras ( Phantom ) generate so much heat ? | Technology | explainlikeimfive | {
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"They are essentially extremely high perfomance computers designed around a specialized purpose. Those 10k frames/second videos at high resolution require a massive amount of data transfer and storage."
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jry23g | Why are USB chargers and power transformers all different shapes, and so many are bigger than the standard gap between power plugs? It really grinds my gears that you either can't plug 2 into the same double wallplate, or have to leave a space in between on a power strip! | Technology | explainlikeimfive | {
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"Because most manufacturers literally don't care. They are designing around internal component choices and their market research for form factors. Also, if they have another power supply that requires the larger form, it may be cheaper for them to reuse the larger case for all their chargers instead of making individual ones to reduce the size."
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jrztt3 | What allows silicon to be this "magical material" that makes computers work? | I understand that at their core, CPUs are simply doing simple mathematical operations. But how does silicon actually allow them to do this? What properties does it have that no other materials do? Can other materials do this too? & #x200B; Everything I've found online seems to have information about what happens down to saying "the CPU does basic mathematical operations", but doesn't actually explain how, at least in terms that I can understand. I'm super curious and hope someone can help. | Technology | explainlikeimfive | {
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"Silicon isn't unique, its just well suited. It has something called a band gap that is in the correct range to be easily used for small transistors. Basically, it's a property that can be utilized to allow the material under certain conditions to act as either a conductor or an insulator. You would be better off looking up transistors and how they function. There are many different types. But basically they act as a switch, either blocking current or allowing it to flow. One of the problems being run into with CPU manufacture is limitations on how small we can make the transistors. Not only are we running into problems with accuracy, the smaller it is the more accurate you have to be to prevent errors. We are also hitting a road block with physics. At a certain point the physics of how a material behave changes once it is reduced to a certain size. Quantum effects come into play and the actual shape and topology of the material affects how it behaves. Oh\\*, also Youtube \"How do it know\". The video doesn't go into the physics, but it does break down very well what is going on inside a cpu as it functions."
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js2291 | how did people in the midevial age or in poor countries discover where to build wells for their village? | Technology | explainlikeimfive | {
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"Wells are just dug down till you hit the water table. Doesn't particularly matter too much where as long as you aren't talking hundreds of miles away. Once you get a hole below the water table, water will seep in from the sides till it makes a pool at the bottom of the well. Depending on geography you might have to end up digging deeper though, so you wouldn't want to start a well from the top of a hill. As for what the water table is, water sinks into the ground and pools on top of solid bedrock. More water = higher water table. It's replenished by rain, and slowly seeps to lower elevations through the ground.",
"Most medieval village wells were just holes in the ground (coronial records show child and drunken drownings were quite common). Plants and soil can be good indicators of ground water. People used these to find likely spots (Australian aborigines used these to find water). Where the ground was soft or water was precious, wells could be lined with stone or, as in Kipling's Bikaner, 400' deep and lined throughout with camel bone."
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js2588 | How did the navigation on the Apollo mission work? | I know there was some sort of astrolabe, but I don't understand how it worked or how the spacecraft reacted to the information it provided. | Technology | explainlikeimfive | {
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"The star charts were just used to calibrate rotation of the IMU (which estimates rotation and mass by measuring acceleration continuously). But since the IMU isn't perfect the calculated rotation would drift over time. By using the stars are a fixed background, a telescope could be told to point a telescope at a specific star based in the readings from the IMU. It would miss the target because of the error, but by manually moving the telescope to point at the star and updating the computer with the real position, the guidance computer could account for the error. Since it's measuring angles it's technically a sextant even though the engineers simplified its use as much as possible. They did also use maps to figure out orbits when near the earth or the moon tho, especially on the early flights to verify the accuracy of the IMU would be good enough to make the trip to the moon."
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js2d9g | How did prehistoric humans fare oceans without any compasses or other advanced technology? | Neolithic humans of various species are known to have crossed various huge expanses of water at a time when their tools likely included nothing more than rope, wood, stone and animal materials. The idea of this terrifies me and I would call it suicidal if somebody attempted it today, yet it apparently happened quite a lot. How? | Technology | explainlikeimfive | {
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"The Polynesians were the best open ocean navigators you'll find that didn't use any math. They used wave patterns, star positions, and knowing the wind to get around. Everyone else normally kept the coast in sight going from landmark to landmark. The few open ocean trips relied on seasonal winds like the monsoon traders who sailed across the Indian Ocean one way in the spring, and returned in the fall when the wind blew the other way. It was still something we'd consider ridiculously hazardous today. There are an estimated three million boats that ended up at the bottom of the ocean instead of their destination.",
"The compass is over 2000 years old but Prior to the introduction of the compass, geographical position and direction at sea were primarily determined by the sighting of landmarks, supplemented with the observation of the position of celestial bodies.[6] ( URL_0 )",
"Most stayed within sight of land. For those that ended up out of sight of land, aside from celestial navigation and the currents, there is some indication that birds may have been used or followed. Following migratory birds to islands in the Pacific has been mentioned, and there's the biblical story of the ark where they release and follow a dove to land or something like that. It's interesting to read about the Portuguese exploration beyond [Cape Bojador]( URL_0 ) which wasn't crossed (with a successful return) until 1434."
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jsdapa | Black and White Film Reel playback Speed | ELI5: Why does black and white film reel appear to make a recording play faster than modern film? (for example: old Babe Ruth World Series footage) | Technology | explainlikeimfive | {
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"Some old films were hand cranked while filming so the pace of the filming isn't consistent and results in different speeds of recording."
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jshb4i | how do they keep oxygen aboard the space station? | Like the title says, how do they keep air aboard the space station? Theres no air to extract from the empty space around it. Do they send up air tanks constantly? If there was a big leak, would everyone aboard suffocate before we could send up more? How does it work? | Technology | explainlikeimfive | {
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"> Do they send up air tanks constantly? Yep, they get a refill now and then. > If there was a big leak, would everyone aboard suffocate before we could send up more? How does it work? They have emergency supplies to re-fill. There's limits though. The risk of suffocation before a resupply/rescue could be put together is real. Simply put, a big enough catastrophe on the ISS would kill everyone. They also have O2 generators and CO2 scrubbers. Lungs for the ISS. They can split water into H2 and O2, powered by the solar panels. And they do something with all the CO2 people breath out.",
"They send up oxygen in the form of water, water is 8/9ths oxygen by mass. They try super hard not to let it leak out. If there is a leak, there are procedures to fix it, and that's very important. They store oxygen, and nitrogen (which is 80% of the atmosphere) in cryogenic liquid form, so it takes up less space, because it is very, very cold on the dark side of the ISS. They use chemical scrubbers, like a submarine, to separate the CO2 that the crew breathes out."
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jsjrkb | Why have PCs had SSDs for years but only with the new gen consoles has no load times suddenly becoming a thing? | Technology | explainlikeimfive | {
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"Cost. Solid state drives were still A LOT more expensive (per unit of storage) when the previous generation of consoles were being designed (around 2012-2013) than they are today. Back around 2011/2012, many consumer SSDs still cost around $1/gb as a rough benchmark. Today, 1tb SSDs can be purchased for far less than $200",
"Besides cost, there's also the introduction of NVMe. SATA SSDs are limited by the SATA interface. * SATA was 150 MB/s * SATA2 was 300 MB/s * SATA3 is 600 MB/s * NVMe is about 4000 MB/s, and also deals far better with a huge amount of requests. Modern hard disks are somewhere in the 200MB/s maximum speed range. In practice on PCs they're far, far slower than that, because seeking takes ages. But a console isn't a PC, and a game can be laid out in such a way that a hard disk gets as good of a performance as possible. There are limits to this of course, but still, given that a console is a specialized environment, it creates the opportunity to squeeze out more performance than you typically get on a PC. SSDs for a while had a problem with the SATA interface. It's made for hard disks. SSDs very easily run into its limitations. You can't go faster than the interface allows. So a SATA2 HDD goes at 200MB/s, and a SATA2 SSD goes at 300MB/s and can't go any higher. So if you replace a hard disk with a SATA2 SSD, sure, you get an improvement, but it's not enormous. Even SATA3 isn't that huge of an improvement. Sure, your levels load twice as fast, and that's nice... but it's not a complete deal breaker. And given that SSDs are expensive and smaller than an HDD, the tradeoff isn't necessarily a great one. The NVMe interface was made specifically with SSDs in mind, and is **still** somewhat of a bottleneck. NVMe on the inside is PCIe, so on a PCIe3 board, you get as much as 4000 MB/s, and on a PCIe4 board, you get around 7000 MB/s. NVMe is the point where hard disks just can't compete, at all. A hard disk, even in the best possible of conditions (which won't really happen) is 20 times slower. In practice, easily hundreds, even thousands of times slower. And this is the point where rather than just loading levels faster you can start doing things like loading data from the SSD while the game is running and not even feel it."
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jsordv | How is it possible that we can record video in slow motion, but sound sounds distorted or choppy? | Technology | explainlikeimfive | {
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"Video is a series of very slightly changing still photos. Too slow it down don’t change the nature of the photos just the rate at which we see them. Sound is the movement of air against our eardrum. The movement IS the sound. To alter the speed world change the sound it makes."
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jsscrw | What is Pi-hole network? | Technology | explainlikeimfive | {
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"Pi-hole is a software that works as a DNS-based adblocker for the entire local network. Meaning if you have one machine running pi-hole connected to your home wifi, you won't see ads on any other machine connected to the same wifi network. It works by setting it up as a local DNS server. All the devices in the network make their DNS queries to the pi-hole server. The pi-hole keeps a large list of domains that are known ad servers. If it receives a query that corresponds to one of those domains in its blacklist, it *drops* the query and nothing more happens. The ad server is never contacted so the device that made that query never receives the ad. If the domain isn't in its database, it forwards the query as usual (likely to the DNS server you'd normally be using without the pi-hole) and everything works normally. It's a good system. Ideally you'd be running on a server that's on 24/7. AFAIK it was originally designed to be run on a raspberry pi, hence the name. But I have it running on a desktop PC converted to a home server. It blocks tens of thousands of ad requests every day."
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jsstt6 | If satellites are orbiting the Earth, how can they still work when they leave the area which they were supposed to broadcast to? | Technology | explainlikeimfive | {
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"Either there are loads of them so one takes over as another leaves (gps uses this), or they don’t move relative to the earth (geo stationary - satellite communications use these)",
"There's 2 possibilities. First, they don't. It's called a geostationary orbit, which means that the satellite is so far up that the time it takes once around the earth is exactly the same it takes for the earth to spin once. In other words, it seems the satellite is standing still right above. That only works around the equator, though. Since the satellite isn't REALLY standing still, it has to go in an orbit, and it can only go in an orbit around the \"whole\" earth, not just orbit at a certain latitude. So if it was inclined, you'd see it go north-south (if you look up from the ground) as it orbits. That the geostationary orbit is around the equator is also the reason why you have to point your sat dishes towards the south (if you're in the north, to the north if you're in the south) to receive the sat programs. The sat you're aiming at is orbiting around the equator. That works for most of the earth, it doens't, though, if you're close to the poles (and I mean really close, most of Canada and Sweden should still be good). Beyond that, sats are often put in a so called Molniya orbit. Look it up on Wikipedia if you're interested. Basically the idea is here to put the sat into a very elliptical orbit that makes it be in the desired position for as long as possible. That way you can handle areas closer to the poles."
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jsuicm | Why do games cost more to direct download on a console than to buy a disc? Surely direct download saves the manufacturer costs on transport, shipping, actual materials for disks and packaging, setting up deals with retailers etc... | Technology | explainlikeimfive | {
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"This is because of a common error people make when thinking about companies pricing products: It has almost nothing to do with the expense to produce it. Suppose you want to make some money. You hire a worker and pay them $10 to make a product, you spend $3 on materials to make it, you spend $0.50 to package it, $1 to ship it, and $2 on marketing. How much should you charge for this product? As much as you can get! The goal is making money, not offsetting your costs with a certain percentage markup. Obviously you need to make more ~~then~~ than you spent on it or you are losing money and shouldn't do that again, but even if you have a product you can't sell for more than you spent on it the goal is still to get as much for it as possible. So in your question about selling a game that the producer doesn't have a bunch of costs they otherwise would have, the price doesn't change because there is no reason for it to do so.",
"It’s all about convenience. Do you wanna drive to the store, wait in line, all that just to buy the game or click a button and it’s yours? Same reason Ticketmaster charges like 120% fees on top of their tickets for online sales. Convenience. I’m sure not going to the box office and standing in line. Same reason AMC now charges a convenience fee for online tickets. It uses no ticket stock but somehow they need to charge more. You could go to Redbox and rent a movie for a buck or two, or click the button on your remote and rent the same movie for $5.99 or so.",
"Phage is spot on with pricing not being related to costs Another factor is that a manufacturer will often promise not to sell directly for less than a certain price as this would undercut the sales of their retail partners. This is common for hardware that is rebranded and sold under a different name, there's no reason to buy the rebranded model for $80 if the identical original model model is only $70. What the manufacturer loses in margin they make up for in volume and reduced distribution costs on their side (its cheaper and easier to send 10k units on a skid to a store than to 10k different addresses)",
"The MSRP is usually the same. The reason you would often find a disc cheaper is that the retailer (GameStop, target, Walmart, Amazon etc) has chosen to offer a sale or discount. Whereas most digital sales are from the software vendors online stores. While they sometimes do run sales as well you’re much more likely to a get a discount from a store.",
"I read that Nintendo have some sort of agreement with retailers that they won't undercut them with their online prices. If the digital downloads were cheaper nobody would go to the stores for them and they'd likely refuse to stock their games. I imagine that's part of the reason for other companies as well, on top of whats already been posted about charging what people will pay",
"This is not a factor of costs. Just because they lower costs does not mean they pass savings onto the consumer. The price of something is locked in to maximize profits. You have two counteracting things -- as the price gets higher, less people buy it, but it also produces more profit. You have to find that sweet spot where the majority of people buy it at the right price to maximize profit. For in store games, people have locked in that price pretty hard. While realistically it could be lower in an online store, there is likely some agreement with a few big retailers that they do not undercut them. It could easily be seen as anticompetitive if the majority of people could buy a game online for cheaper, and stores are only there to help with the people who need physical purchases.",
"There are two other things that I haven’t seen in the other comments. 1. Even though digital is cheaper to produce but there are costs associated with hosting and maintaining servers where the digital code is stored. 2. Companies that publish video games don’t want upset the relationship with stores that sell physical copies of games. If EA sells their games cheaper digitally on Xbox or PlayStation than GameStop or Walmart there will be no incentive other for retail stores to continue selling EA’s games and if they do that then EA will lose a lot of money.",
"Simple answer is to have parity with brick and mortar stores and to not upset your supply chain. If you make things inherently cheaper online, you're going to have your stores upset that you're undercutting them. Start doing that and all of a sudden they have no room for your consoles or accessories. So even if you can sell for cheaper online and selling online is inherently cheaper than shipping a disc and displaying it, you want to keep the prices the same to appease stores that sell your products so you have a footprint in the physical places people shop.",
"The console manufacturer, or even the game producer, does not want to screw their own distributors by undercutting them. Obviously, nobody can price-compete with the manufacturer. If Blizzard was selling Diablo for $40 on their website while everybody else was selling it for $45, obviously nobody would buy it anywhere else. Great, you think, Blizzard gets all the profits! In reality, they lose a lot of money because nobody will even try to sell that item in their own shops. Blizzard loses all the sales in physical and online shops. If you go to a manufacturer of any product and try to buy it as an end user, they will most likely send you away with a contact number to one of their vendors.",
"Part of it is that digital stores rarely have an incentive to unload product. If you're a GameStop and you've got 100 copies of Barbie American Ranger Firefighters on shelves, there comes a time when you need to get rid of BARF at a lower cost to make room for BARF 2. Even if you don't make as much money selling them, at some point, those copies of BARF are costing you money to have around because they are taking up space. With digital distribution, there isn't a physical space demand forcing your hand",
"Because they can, and it's good business sense to do so. The monetary value of anything is what people are prepared to pay you for it - not what it costs you provide it. People often have the naïve idea that companies are in business to serve their customers. They're not; they're in business to do what's best for their shareholders. The two sets of interest may coincide - but often they don't. Basically - if a significant proportion of your customers will pay a premium for an immediate download, you likely charge one. If it's cheaper to do that as well, that's even better; more profit to cover your costs, reinvest or pass on as dividends. What you're not in business to do is to pass that saving on to your customers, unless it's as a consequence of some hard-nosed business decision that it will likely bring a return. OK, so some people won't like it, and will walk away. Others will be prepared to wait and buy the physical media. You factor all of that into your calculations and relative pricing."
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jsv9fu | Why did the musket outclass the bow? | Technology | explainlikeimfive | {
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"The reduced training and skill requirement is a lot bigger than you might think. A bow requires constant training and some serious arm strength to use effectively, whereas muskets level out the skill requirements considerably and almost entirely remove the strength issue.",
"The native Americans in the North weren't killed with muskets. Most of the non-biological slaughter occurred much later, with rifles. Unless you mean the earlier ones in Mexico, South and Central America. Those weren't killed with muskets either. Cannons, horses and steel swords had a much bigger impact, as the cloth and padding armor offered no protection against them. But again, it was the element of surprise, intimidation and disease that were the deciding factors. Bows in the Americas weren't commonly used for warfare, slings and spears were much more common. The style of warfare in Meso-America was intended to capture rather than kill.",
"Killing someone else is 1% killing, and 99% logistics and background to put a soldier into the right position to do the killing. A musket plus a month of training transforms a 14 year old boy into a killing machine more deadly than a lion, a roman battle hardened roman soldier, a spartan, or a native American warrior who had spent a lifetime training. Two or three months training and perhaps some combat experience will turn this boy into someone who could comport themselves well against any professional army in the world (at that time). That is an insanely cheap and fast way to make a soldier. Next imagine the advantage of the boat. Basically without any advanced warning at all hundreds of armed and ready to fight soldiers can be deposited on the ground anywhere there is water (and keep in mind, every population center you have is going to be beside the water). Next imagine the advantage of surprise. How many native soldiers would survive one battle with western forces so that they could go on to fight in a second? Not many. Those troops couldn't possibly convey the feeling of being under gunfire to the natives who had not been at the battle. All those experiences that soldiers have to get used to in order to perform well in combat would be denied to the natives in any great numbers. Next imagine the situation you are trying to fight in. 90+% of everyone you ever knew is dead from disease in the past few years. Many of the survivors are injured from battles with westerners, or have turned to alcohol (something your culture has no real experience with). I mean shit if your entire family was killed by disease you'd drink too and you come from a society that knows alcohol is addictive and dangerous and isn't some kind of spiritual aid. Next imagine how many battles you would need to lose in these situations before you say it isn't worth risking your life and instead retreat as far as you can, avoid contact with westerners at all costs, etc. The retreat has always SUCKED.",
"Musketry is a *very* effective way to kill people at a distance. A musket ball delivers a huge amount of energy to the target compared to even the heaviest bows. Gunfire is also extremely loud and quite disorienting, especially if you aren't used to it. Realistically though it wasn't the musket that won, it was logistics and organization. Native bands decimated by several generations of pandemic disease simply didn't have the resources to defend themselves against large groups of well organized invaders."
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jswc32 | When removing objects from a photo in Photoshop, how does Photoshop recreate what is behind the person so accurately? | Technology | explainlikeimfive | {
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"For the most part it doesn't - the artist has to manually clone it in from other parts of the image. However, these days there's also AI object removal that works by having been fed millions of images. It can then look at the current image and say \"ok, when I've seen this before it's looked like *this*...\"",
"Well, for starters, there's no \"one way\" that backgrounds are recreated. The two methods people generally use are content aware fill, which let's the computer analyze the area around that which is being removed and average the results and look for patterns. So if there's a line going into one end and out the other, the computer can usually guess the line continues through the image. This is generally only used for small spots on uniform backgrounds though, like removing acne For larger, more professional edits, you're gonna use a clone/stamp tool, in which you actively choose other parts of the imagine and cut and paste them into place. This is human driven, not AI driven. You can then adjust the \"feather\", which is like a gradient/fade that lets it blend a little easier.",
"It doesn't - you have to build the image yourself on another layer (or layers, built one on the other in a particular sequence)(. Or, you can use several different tools to change an image (cut and paste, cloning tool, eraser, filters, blurring, etc.) Images are basically information, and you have to add, subtract, and manipulate the information you have in order to create a new image. It won't 'make itself'. That's why being good at PS is an art that takes practice, and why a good PS person can spot a bad edit a mile away. :)"
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jt018a | How are some digital scales able to tell such little weight differences? (Such as between 0.00g and 0.01g) | Technology | explainlikeimfive | {
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"The difference between 0.00g and 0.01 g is only little in terms of your perception of the world. There's 2.618*10^20 atoms in 0.01 grams of salt. (That's a lot) so if your method of finding out a sample's weight was counting atoms, then 0.01grams is an enormous weight. We, humans, are bad at weighing things. Digital sensors are not. The one in your kitchen scale works by converting the weight to a small current. More precise scales work by essentially having the scale vibrate, and measuring the degree to which the object you try to measure interferes with that vibration."
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jt41d9 | Why is the URL of google searches so long, what does it all mean? | Example: If I image search the word "adorable" in google images this is the URL I get: " "[ URL_2 ]( URL_0 First: Why is it so long and not something short like "[ URL_3 ]( URL_1 )" for example? Second: What do all those strange abbreviations (if they even are abbreviations) mean for example like "tbm = isch" and ved = "some random letter of numbers)? Edit (Thanks): HOLY s\*\*\*, was satisfied with 2 answers and went to bed. Woke up to 400 comments, 8k upvotes and a bunch of awards. Not that it would mean anything important but thanks for all the replies. | Technology | explainlikeimfive | {
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"A lot of that is tracking information. Here I'll break down your entire URL for you. `q` = The query it's actually searching for. Usually the same as `oq` unless you clicked on a suggested search term, then `oq` would be the text you typed and `q` is what you clicked on (what's actually being searched for) `tbm=isch` tells it you want to search Google Images. It stands for **t**o **b**e **m**atched = **i**mage **s**ear**ch**. `ved` decodes to tell Google what links you clicked on previous pages on Google to get to the current page ([ URL_3 ]( URL_3 )) `oq` = The original query you wanted to search for that you typed in (see `q`) `gs_lcp` = Not sure, but it's Protobuf encoded. Edit: Someone said in replies this is likely to encode to a physical location, which also seems likely. `sclient` = Where you came from (so if you used [ URL_2 ]( URL_0 ) it would be `img`) `ei` = an encoded string that tells it the time of the request ([ URL_1 ]( URL_1 )) `bih` = Browser height (pixels) `biw` = Browser width (pixels) `hl` = Host language (what language you want, in this case `en` for English).",
"Those are called parameters - they're a way to pass information about a click to the next page. For example, if I had a store front website, instead of making a separate .html page for every product, I could tell the server what product details to reply to the request by doing something like: URL_0 That way I don't have to build a page for each product, I just build one (moreinfo) and pass the product id (1234) to the server. The server then replies with info about product 1234, and the page (moreinfo) is built to display that info. It can also be used for tracking, if I display ads on every page I can dynamically add ?source={currentpage} (replacing {currentpage} with some identifier unique to every page) then the server knows which page I clicked the ad from. I can then use this information to discover which page users are most likely to visit ads from. As for what those parameters mean on Google, that's hard to say without having inside knowledge. You can guess on some of them though - \"bih=610\" sounds like some form of height parameter (not sure what \"bi\" means) whereas \"biw=1280\" sounds like a width parameter. Additionally \"hl=en\" may refer to \"English\", but I'm not sure what the \"hl\" (parameter name) is short for.",
"So, every little string that starts \" & \\[x\\]=\" is a parameter, with \\[x\\] being the parameter name and everything after the = being the parameter value. So as described by others, \" & hl=en\" means \"host language = English\" so Google knows what language to display results in. That big old \"gs\\_lcp=\" parameter is most of what makes the URL so long. A quick couple of searches gave me some computer scientists trying to figure out what it does, but no actual answers, so presumably it's some complicated search tracking magic for Google that they don't want to publicly explain.",
"It used to be short, with just `q=` :-( `q` is the query; `oq` is the original query, for when you're exploring query refinements (I don't know if they have this anymore); `hl` is the language for the search page (there's a separate one for the language of the pages you want returned); `client` was the external partner like Yahoo but I don't know what `sclient` is . They kept adding more and more over time :-/",
"gl Optional Parameter defines the country to use for the Google search. It's a two-letter country code. (e.g., us for the United States, uk for United Kingdom, or fr for France) Head to the Google countries for a full list of supported Google countries. hl Optional Parameter defines the language to use for the Google search. It's a two-letter language code. (e.g., en for English, es for Spanish, or fr for French) Head to the Google languages for a full list of supported Google languages. lr Optional Parameter defines one or multiple languages to limit the search to. It uses lang_{two-letter language code} to specify languages and | as a delimiter. (e.g., lang_fr|lang_de will only search French and German pages). Pagination start Optional Parameter defines the result offset. It skips the given number of results. It's used for pagination. (e.g., 0 (default) is the first page of results, 10 is the 2nd page of results, 20 is the 3rd page of results, etc.). num Optional Parameter defines the maximum number of results to return. (e.g., 10 (default) returns 10 results, 40 returns 40 results, and 100 returns 100 results). ijn Optional Parameter defines the page number for Google Images. There are 100 images per page. This parameter is equivalent to start (offset) = ijn * 100. This parameter works only for Google Images (set tbm to isch). Search Type tbm Optional (to be matched) parameter defines the type of search you want to do. It can be set to: (no tbm parameter): regular Google Search, isch: Google Images API, vid: Google Videos API, nws: Google News API, shop: Google Shopping API, or any other Google service. Advanced Filters tbs Optional (to be searched) parameter defines advanced search parameters that aren't possible in the regular query field. (e.g., advanced search for patents, dates, news, videos, images, apps, or text contents). safe Optional Parameter defines the level of filtering for adult content. It can be set to active, or off (default). nfpr Optional Parameter defines the exclusion of results from an auto-corrected query that is spelled wrong. It can be set to 1 to exclude these results, or 0 to include them (default). filter Optional Parameter defines if the filters for 'Similar Results' and 'Omitted Results' are on or off. It can be set to 1 (default) to enable these filters, or 0 to disable these filters. Ref: URL_0",
"Even a lot of regular non-search engine websites attempt to do this sort of URL-based tracking. News sites, whatever. There is a browser extension called \"ClearURLs\" that attempts to \"automatically remove tracking elements from URLs to help protect your privacy when browsing through the Internet.\". Sometimes it works and sometimes it doesn't, but when it doesn't, it still displays the website you're looking for. I don't know if it works for Google's search engine specifically, because I don't use Google for search, but it works for a lot of non-search stuff that uses similar tracking techniques to what you posted. It is available for free for both the Firefox and Chrome desktop browsers, along with almost any other desktop browsers based on the same code as either browser (Examples include Vivaldi, recent versions of Edge, and Waterfox, but there are more), as long as they use the same extension stores. As far as I know, because Chrome doesn't support extensions on Android at all, and Firefox did a redesign that drastically cut back on the number of extensions it allows on Android, the only stable Android browser that is still being maintained that has it available is Iceraven (A fork of Firefox), which you can download here: URL_1 If you decide that you specifically don't like what Google is doing based on the responses in this thread, a good alternative search engine that you can make the default search engine for virtually any browser on earth and virtually any device on earth is DuckDuckGo: URL_0 One simple trick for some of these longer URLs on general non-search sites is that often the question mark and everything after it are unnecessary tracking, not always, but like 90% of the time. So, *usually*, you can take that part off of a URL, copy what remains of the URL in a new tab, hit enter, and it'll load just fine without all the rest of it. That trick is really only helpful if you are trying to share link with friends, though, because few people look *that* closely at a URL before they click on it. Once it's staring at them in the URL bar, though, more people do. Google also has a scheme called AMP where it stores it's own formatted versions of websites on its own servers and sometimes tries to disguise it. There is an extension called \"AMP to HTML\" that is available for basically all the browsers \"ClearURLs\" is available for and not available for basically all the same ones the other ones isn't available for, that tries to get you to the real non-Google non-AMP version of a page when you click on a link to an AMP site (As with the other extension mentioned, sometimes it works and sometimes it doesn't)."
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jtb23z | How exactly does a automatic weapon work? | I have a basic idea of how a gun works. Like the firing pin hits the primer in the shell and the round fires. But for automatic weapons how does the firing pin reset? | Technology | explainlikeimfive | {
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"When you shoot a gun, not all of the energy from the explosion gets transferred into the bullet. For ex, if you shoot a revolver, the kick will move your hands to a different position. Automatic weapons harness that mechanical energy using pistons, springs, and levers to cycles the gun completely. So basically you use a small part of the energy from the explosion to eject the spent casing, cycle the bolt, move a new cartridge into the chamber, and rearm the firing mechanism.",
"This video has a simple explanation of the process. But a little spring will put the pin back into position. Similar to like a clickable ball point pen does. URL_0",
"While the bullet is being pushed down the barrel by the expanding gas from the burning powder, some of that gas is redirected to (in the easiest-to-understand design) drive a piston, connected to a mechanism that unlocks the bolt, pushes it back, and latches the firing pin in the cocked position. Then a spring pushes the bolt forward, snagging a cartridge from the magazine and pushing it into the chamber."
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jtb2q4 | Why do we need HDMI for HD video but cable can do it using a coaxial cable which is usually is associated with low quality SD video? | Technology | explainlikeimfive | {
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"You don’t need HDMI for HD video. My set top box is happily stuffing multiple 4K streams through a coax as we speak. Coax is *extremely* high bandwidth."
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jtc9jl | Why does Wifi use a signal strength icon that doesn't seem to correlate at all to your ability to access the internet via Wi-Fi? | I've always wondered about this, since I couldn't connect to very strong Wi-Fi in my college dorm over a decade ago, and just now when I've failed at troubleshooting my home Wi-Fi which showed a strong signal but that I can't connect to. Why do strong signals show up that you can't connect to? Why is the default measure of Wi-Fi an icon of signal strength that seems to have no bearing on your ability to access the Internet? | Technology | explainlikeimfive | {
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"WiFi strength indicators are exactly that: The strength of the WiFi signal, that is, the amplitude of electromagnetic waves at 2.4 GHz received on your device (usually measured in dBm). It does not reflect intermittent connections, loss of packets, collision, latency, bandwidth, and pretty much anything for that matter.",
"Because WiFi is not the Internet. WiFi is a *local area network* (LAN) technology. It connects computers to wireless access points (known as \"infrastructure mode\") or computers to computers (\"ad hoc\" mode). Whether or not the device on the other end of the wireless link has access to the Internet is not a concern of the wireless LAN."
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jtfjci | Why the sudden interest from governments to build mini nuclear reactors? | Technology | explainlikeimfive | {
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"Ultimately, nuclear is the power of the future. It's the only technology we know of that can be deployed on a widespread basis for baseline power with sufficient power density to maintain a highly developed society. However, our model of nuclear reactors is decades out-of-date. The nuclear reactors we've been using were originally developed for naval vessels and then just clumsily ported over to fixed land installations. A virtual moratorium on technological development has left us decades behind where we should be in terms of power generation - if we had spent that time improving nuclear it's likely that most developed nations would be all-nuclear by this point. So there is considerable incentive to develop nuclear. Unfortunately, there are massive obstacles in terms of regulation that make developing new nuclear technologies difficulties. Smaller nuclear reactors are able to sidestep many of these regulations - especially in the development stage - due to research exceptions. There are also practical issues such as being able to deploy them more flexibly and potentially closer to power demands.",
"In the UK, 25% of power generated is through nuclear, with how old some of these are half will be retired by 2025. Coal power is on the way out with a number of sites being closed and renewable is not there to power a whole country yet."
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jtfknd | why do certain websites ask "are you a robot?" | Technology | explainlikeimfive | {
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"text": [
"Legitimate sites that ask you to complete a captcha (select images that contain a walrus, etc) are trying to filter out automated queries and for one reason or another aren't sure if you're real or not. Sites do this to prevent bots from automatically harvesting data from websites, or flooding it in a denial-of-service attack. You can be mistaken for a bot by doing certain things, like clicking through the page too fast, or simply be subjected to such a check before submitting a form. Sites that ask you to **Click Allow Notifications to Prove You're Not a Robot** are malicious and are usually hijacked domains. They want you to allow browser notifications so that you can be served advertisements and spam directly to your desktop. Do not click on them, it's a nuisance to remove it from your browser if you do."
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jtisor | How does clipping out of bounds work? | You'd think this question has already been answered, but I've mostly found questions about why it happens - as in, why clipping bugs don't get filtered out of some games etc. I'm specifically wondering what makes the player pass through objects or walls, I know it has to do with hitbox collision detection messing up, or something? Thanks in advance if you take the time to answer :) | Technology | explainlikeimfive | {
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"One big thing is that most objects in games are hollow. There's no collision detection on the inside, because there doesn't need to be, and it's extra computation that isn't needed. If two objects can't get past the initial collision with the surface, their insides will never need to collide. This can lead to situations where *if* the player avatar somehow manages to be on the wrong side, the game has to figure out where to put them, since their surfaces aren't allowed to touch. The best the game can figure out is to shunt you all the rest of the way through. This can happen in a couple ways, like going too fast. Your avatar's position isn't continuous, it gets calculated with each game computation cycle. If you're going fast enough, the game calculates your position based on your speed to be on the wrong side of the wall. It also happens a lot at corners. When you have several surfaces interacting at the same time, sometimes the results of one calculation are incompatible with one of the others. The game has to compromise and figure it out, which sometimes puts you on the wrong side, or does something wonky to your speed (which puts you on the wrong side). It doesn't always get patched out because it's a weird unique corner among thousands of corners, which just *happens* to let you out of bounds if you hit it with just the right speed and angle. They can't find all the possible interactions, so they just do their best. Or, the game doesn't normally allow the speed necessary, but there are other exploits that shouldn't exist to make it happen."
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jtk5ap | How can website detect that you are using a adblocker? | Technology | explainlikeimfive | {
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"text": [
"Adblock detection is done in couple of ways. The most common way is to look for elements that should be displayed and aren't (ads.js for example). Another way is to check if a CSS property has the value you expect it to have or check for hidden browser windows.",
"The other responses are talking about detecting elements on the page. Another way is to make a request to the address that serves ads. If it fails, you know that ads are blocked."
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jtkip1 | why wireless electronics are less responsive than wired electronics | This never made sense to me. Let’s take a the example of a keyboard. I have tried both wired and wireless keyboards side by side and I could clearly tell that the wired keyboard was quicker than the wireless one. You get the same results with mice, controllers, speakers, etc. But why? Electrons aren’t even close to being as fast as the speed of light. So how is the wired one faster? | Technology | explainlikeimfive | {
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"text": [
"It takes more time to encode the signal as a radio signal, an then decode it back into an electronic signal, especially with the cheap electronics used in wireless peripherals While it’s true that electrons are slower then radio waves, even if that was the only limiting factor, the difference would be too small to be noticed anyways"
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jtpcwv | What are the cookies websites tell you to accept | Technology | explainlikeimfive | {
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"text": [
"Cookies are small files that a website, advertiser, etc. puts on your computer. Not all cookies are created equal. Some are pretty useful - it's how you can stay logged in to a website after you've restarted your computer. Sometimes, especially in the past, it was used to keep track of your settings on a website (like what theme you used, though nowadays a lot of that information is kept on the server). They can *also* be used to track your activity, though, to see what you're doing online. And based on *that* they can send advertisements your way based on your viewing, browsing and shopping habits. It's how you go to Amazon and look up baby strollers, then go to CNN and see advertisements for baby strollers; an advertiser (or Amazon) has put a tracking cookie on your computer and then is using that data to tell advertisers on other websites what to show you."
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jtthax | How are we able to create pieces of technology smaller than any tools we can work with? | For example, sd cards. You get a micro one that's smaller than your fingernail, how are you able to achieve that? | Technology | explainlikeimfive | {
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"text": [
"precision machinery can make the plastic and SD card parts. the computer chip and transistors inside are what are truly amazing. these are patterned on a silicon wafer using light sensitive plastics, chemical etching, oxidation, planarization (thing buffing/sanding) and film deposition techniques.",
"You can't make the things directly with hand tools true. But you can make tools that make tools that are tinier than you can work with directly. In the simplest case it comes down to some sort of multiplication of precision. Think of like a huge lever. If you move one end 1 meter the other might move 1 mm. If the lever isn't super bendy if you are off by say 1%, or 1 cm, the other end is off by 10% ish, which is .01 mm. Similar principle with lithography which is used to make chips. They take a large light pattern and shrink it down with lenses into a small light pattern. And in an even more intense scale electron beams and ion beams can be used to etch away material or add material a few atoms at a time. In this case it's computer controlled electromagnets that swing the beam around. The lever effect is still there though. Relatively large magnetic fields that we can control with computers are used at a distance that moves the beam around a very small amount proportionally. At super high levels of precision though you can run into all sorts of problems with temperature screwing with your equipment by expanding or shrinking the machine. Or people walking nearby, and super precise machining might need to be done in a temperature controlled concrete bunker. But if that's what needs done its what gets done. For some of the more mechanical stuff def check out original of precision on youtube. It's a neat video. URL_0",
"The ELI5 answer is a combination of very, very tiny, very precise machines and a process similar to inkjet printing. Or more accurately, like developing a photograph. Essentially 'printing' a chemical on a wafer, exposing it to light to etch away the unprinted part and then flooding it with whatever they want (say, some type of \\[doped\\] silicone), which sticks to the etched areas. Lather, rinse, repeat. There's a bazillion youtube videos on it. If you look up how PCBs are made, especially if there's an actual How It's Made episode, it should make it much easier to visualize and understand."
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ju0cix | Why are processors so small? Double the size, double the performance? | Technology | explainlikeimfive | {
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"Electricity 'only' travels at the speed of light, and you need to make sure that all the parts of the CPU are still on the same clock cycle. Modern CPUs are doing several billion clock cycles per second, so there is a limit as to how far electrical signals can travel within one clock cycle. One way to get around that limitation is to use several CPU cores on the same chip that can do their work semi-independently and don't necessarily have to be perfectly in sync with the others.",
"That is how multi chip modules from the Core2Quad to the Threadripper do it. The main problem in making massive CPUs is the cost increases with the die size and the yield goes down. Let’s say there are 10 defects on a 300mm silicon wafer and our die size is 10mm x 10mm we would get 94 dice -10 with defects (84). If we double that to 20mm x 10mm we get 47 dice -10 with defects (37) and the cost of one 300mm wafer remains the same. So each 20mm x 10mm CPU costs more than twice as much as the 10mm x 10mm CPU to produce. Disclosure: I’ve worked in a semiconductor plant and have a degree in electronic engineering."
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ju102r | Which common processes in video editing are the most intensive and which aren’t (and why)? | I know nothing about video editing, but I wanted to know which “processes” in video editing take 20 mins and which parts are instant. This is referring to when people compare laptops and note how long they take to “render” a video. What I wanted to know is which common processes can be done instantly and which ones have a wait time depending on how powerful your processor/graphics are? (And maybe a quick definition if you can, like I’m not exactly sure what “colour correction/grading” entails, is it like adding a filter?) As a side note, for example a lot of video “editing” features were added to iOS a while back, where its essentially adjusting contrast, saturation, etc - would this be classified as one of those processes or is it just a simple bunch of manual settings you can manipulate. Thanks! | Technology | explainlikeimfive | {
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"text": [
"When you are finished editing your video, it's still in separate bits and pieces in the computer's memory. You have to permanently bake all those layers into one and then compress it via a video codec to get the finished product that isn't 20GB. This is the process that takes a long time. Another gain you get from a good CPU (and a fast NVMe drive to store your source materials on) is \"scrubbing\", when you move your preview back and forth while editing. The software has to do a halfway-kinda rendering on the specific bits of the video you want to preview to show it to you, which can be laggy if your CPU is weak."
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ju2k92 | I leave the same time every morning and same drive. Yet some days my FM radio channel has a lot of interference and I canta hear my channel. There is not a cloud in the sky. I’d say this happens a couple different days each week. Why is it like that when the situation is always the same? | Technology | explainlikeimfive | {
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"text": [
"Interference can manifest itself from many seemingly benign sources, differences in temperatures along the cable path from the radio decoding the signals and the antenna can induce electrical artifacts that the radio itself misinterprets, small flaws in the wire and antenna itself can cause discontinuity along the conduction path degrading the signal before the radio can read it and differences in temperature can cause those flaws to be slightly different through many seemingly identical circumstances. Changes in the Earths magnetic fields and the sun's activity can also add artifacts to the signal, which if your radio were complicated enough could be compensated for, but also require lots of scrutiny on your antenna, its conductors, and all paths to ground along the equipment. Finally, there can also be bleed-through from neighboring radio channels that happen to be too far away to notice most of the time but manage to have 'good days' where it bleeds through and over your preferred channel, and other types of synthetic interferences from similar circumstantial causes. There is a lot more things going on in all of these scenarios, but that is the gist, it's mostly the electrical engineering quality of your radio itself, and the shortcuts to make it cheap add up to poor reception and negotiation of amplifying the signal it is trying to look at."
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ju2twt | Why do Smartphones advertise cameras with "64 Mega pixel resolution!" when the most common resolution (1920x1080) doesn't even cross 3 Mega Pixels? | Technology | explainlikeimfive | {
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"Its not about the resolution of your screen. Because a higher pixel count allows more detail to be captured in the images which means you can zoom in on your pictures even further while still maintaining max detail. If you have ever changed the settings on your camera to 1mp and taken a photo then compared it to a 10mp photo taken on the same device you will know that if you zoom in on the same spot on each, the 1mp shot will be really blurry in comparison. I remember there was a 360 degree photo taken of the London skyline. It was 1 giga-pixel or something stupid like that. You could actually zoom to about 2 miles away in the photo and make out cracked tiles on the roofs of the buildings.",
"Higher resolution matters if you want to print the photos, display them on a higher resolution screen, or zoom in on details. I know most people don’t print photos these days, but if you do, then you need at least 300 dpi. That means your 1920x1080 image can’t be bigger than around 3.5”x6”. A 64 megapixel image can look good as a full-size poster."
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ju46fb | What are WhatsApp security codes and how do they work? | Every now and then, I open a WhatsApp group and see "xyz's security code has changed. Tap here for more info". I have no idea what that is and how that's supposed to ensure end to end encryption. It says I can scan it on the contact's phone, but what does that do? Can someone please explain this? | Technology | explainlikeimfive | {
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"Best way to describe encryption is say to want to mail a box to a friend, but you don't trust your post man. So you put your box into a chest and put a lock on it. You then mail it to your friend and when he receives it, he can't open it because your lock is on it. What he does is, he puts his own lock on the box as well and mails it back to you. Mow when it come in the mail back to you, you take off your lock, and then mail it out again to your friend, who can take off his lock. Now you know 100% that your post man hasn't opened your box and found the kraby patty secret formula.",
"Basically when you register your phone on WhatsApp your phone will generate a key - for this let's say it's 12345. When you start a new conversation with a new contact you essentially swap keys with them and those keys are used to sign off the message. So any messages they recieve from you, their device is expecting the 12345 key to be received to prove legitimacy of the message. Everytime someone starts a new instance of WhatsApp a new key is generated and this is exchanged with contacts so they know to expect the new key. The QR code scanning thing is to verify devices so it basically says to the other device \"Hey, is your security 12345?\" Which either a yes or no answer. Hopefully this explains it a bit better (to the best of my knowledge) if anyone can correct me on things feel free too!"
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ju6ruc | How does music travel from the device to the earphones? How is this information recognised by the earphones, subsequently creating sound? | Technology | explainlikeimfive | {
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"This is very simplified but to show you the concept; A speaker is a membrane that gets tensed up by electricity, and as such making the membrane move which in turn pushes out a wave, which is what we perceive as sound. In the most simple version you simple need a positive and a negative pole from a battery, which you connect to the membrane. By turning on and off the positive node you can create different wave forms, resulting in different sound. As a side note, the saying blowing a speaker refers to a tear in the membrane, which causes bad sound. In addition to the membrane you also need something to reflect the sound the best way. To try the concept, put your phone into an empty glass or bowl while playing music. You will notice the sound being louder.",
"Speakers, whether they are headphones or loudspeakers are called transducers. Transducers (a small, thin film is connected to a metal coil) receive the information from it's source and convert it to sound waves which your ears perceive as music."
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ju80zi | How do they re-release low-definition movies from the 1980s in Blu-Ray and 4k? | Technology | explainlikeimfive | {
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"Basically, those movies were recorded on film stock, which actually is a high-definition format, we just didn't have the technology to display the full resolution that the movie cameras were capturing back then. But if the original film exists, you can scan it, and get a high definition version of the movie that can be put on Blu-Ray or 4K releases. This can only be done for movies that were recorded on high quality material, and where the original film exists."
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ju8ket | what exactly are tesla coils? | I know they throw power through a few coils and end up shooting lighting. But is it really easy to make, or difficult? | Technology | explainlikeimfive | {
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"They are a kind of air core transformer. There are two coils, one small wrapped around a really large one's bottom. By putting very abrupt pulses of electricity through the smaller coil then cutting it off completely, the magnetic field generated by the smaller coil gets reabsorbed by the larger one instead and, since it has so much more turns, it manifests as a stupidly high voltage (but low current) pulse. URL_0"
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ju9iqk | Why does Greenland look so huge on a map if it is not that big? | I just found '[ URL_1 ]( URL_0 )' and i feel like my entire life is a lie. I thought greenland and canada were huge and this is telling me they arent... | Technology | explainlikeimfive | {
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"Take an orange. Peel it carefully keeping the rind in one piece. Flatten the rind down onto a table. See all those spaces that have been created by flattening them out? Now imagine filling them in so you end up with a nice pretty rectangle. That's why a 'common' map makes greenland, russia, and canada look so amazingly huge. It's the imaginary space thats been added to turn a globe into a rectangle.",
"The problem is the earth isn’t flat like a map. So the land at the top and bottom is more stretched out."
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juag9n | Why does a 1TB SSD offer only 931GB of space? | I installed windows on a 1TB SSD, and then when I see the local drive in windows explorer, it shows as only 931GB. Why is this? | Technology | explainlikeimfive | {
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"Part unit confusion, part reserved space. The unit confusion is that early on, the computing industry appropriated the metric prefixes like \"kilo\" and \"mega\" to mean powers of 2. So in metric, \"kilo\" is 1000, in \"computer tech\" it's 1024. A megabyte is then 1024 * 1024 = 1048576 bytes, a gigabyte is 1073741824 bytes, and a terabyte is 1099511627776 bytes. Operating systems tend to stick to this system, so a 1 MB file is 1048576 bytes long. The hard disk industry on the other hand prefers the metric meanings, because 1000000000000 bytes are cheaper to provide, you get to deliver almost 10% less! Then there's that disks are specified in their raw size, but to actually store something on them various accounting data needs to be written, and those consume part of the space. So even if a disk technically has a trillion bytes on it, in practice you are using some to keep track of where what is located.",
"Not quite ELI5, but here's an ELI11. When you're asking a computer operating system, and it replies some number of KB or MB or GB or TB, it uses multiples of 1024 (which is how computers \"think\" - blocks of 2 to the power of 10 - which equals 1024). The proper names of these, by the way, is not kilo, mega or gigabytes. It's kibi (kilo binary), mebi, gibi etc. Sounds silly to say, everyone agrees, but that's the [formal, proper notation]( URL_0 ). But computer storage manufacturers - the people who make SSDs - actually don't play by those rules, and use kilo, mega and giga the same [SI base unit]( URL_1 ) way that we use in all other things we measure in SI. They literally mean Kilo, not Kibi. a Kilometer means 1000 meters. A Kilogram means 1000 grams. A Kilojoule means 1000 joules. They mean 10 to the power of 3, not 2 to the power of 10. And yes, cut and dry, they are not in the wrong to state that a kilobyte is... 1000 bytes. So when you buy an SSD and the box says 1TB, it very literally means 1,000,000,000,000 bytes. But when your operating system looks at that exact number, it calculates \"How many Gi**bi**bytes (e.g. blocks of 1073741824 bytes e.g. blocks of 1024 x 1024 x 1024)\", comes up with 931 (plug it into a calculator and check for yourself :)) and says, right as your question suggests, just that. Extra bit: Why do SSD makers do that? Why won’t they use Gibi? Because humans think using “categories”. Human brains put 99.99 in a different mental box to 100, and humans relate differently to each box. It’s the same reason stores put $99.99 rather than $100 on a price tag (to make us feel it’s “small” - cheap in this case), and also exactly why an SSD maker writes 1000 and not 931 on the box (to make us feel it’s “bigger”).",
"Part of the space is taken by Windows itself. Another problem is how the byte is intended: formally a Terabyte is 2^(40) bytes (i.e 1024 Gb) while for productors it's intended as 10^(12) bytes (i.e 1000 Gb) that is a little less",
"Windows and the SSD use a different definition of what a GB and TB is. The computer is based on a multiple of 2 so for stuff like a memory you get stuff in multiple of two. So people used kilo for 1024 that is 2\\^10 even if the usage outside computer is kilo=1000 So you have binary units with multiples of 1024 and decimal unit with multiple of 1000 Binary, that windows use * 1 kilobyte = 1024 byte * 1 megabyte=1024 kiloyte=1024\\*1024 byte * 1 gigabyte=1024 megabyts=1024\\*1024\\*1024 byte * 1 terabyte=1024 gigabyte=1024\\*1024\\*1024\\*1024 byte Decimal like the drive use * 1 kilobyte = 1000 byte * 1 megabyte=1000 kiloyte=1024\\*1024 byte * 1 gigabyte=1000 megabyts=1000\\*1000\\*1000 byte * 1 terabyte=1000 gigabyte=1000\\*1000\\*1000\\*1000 byte So 931 binary GB=931\\* 1024\\*1024\\*1024 = 999 653 638 144 bytes 1 decimal TB=1000\\*1000\\*1000\\*1000= 1000 000 000 000 bytes 999 653 638 144/ 1000 000 000 000 =0.99965 =99.965% of each other So the difference is less the 0.04% and that will be in large part what windows used for the fil system. Hard drive manufacturers do state on their web pages and disk packaging what definition of TB etc the use.Windows also show at if you look at the disk properties where you will find the disk capacity in both bytes and in GB. The SI and previous metic system have used the prefixes longer than computers with the 1000 definition. kilo is from 1795, mega from 1873, giga and tera is from 1960. & #x200B; So the drive is 1TB in size but it and windows use a different definition of GB and TB"
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juat0q | Why do sports bars have captions turned off when they have TVs on with the sound off? | Technology | explainlikeimfive | {
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"CC for sports is going to be a play by play that isn't at all synced up to what's actually happening and it's a big black box randomly positioned that will likely block some part of the image. Also most sports bars have a switching system setup so they can adjust which audio is going to be live, the better ones adjust to the more pressing games for the clientele at the time.",
"As someone who has spent a lot of time watching sports both live and in sports bars, it comes down to a combination of reasons: * Closed captions tend to run 4-10 seconds behind the actual announcing, making them much less helpful for anybody relying on them to keep track of the play. The captions are also often full of errors, and do block out a significant portion of the screen at larger sizes. * Most sports bar employees are not going to immediately know how to turn the closed captions on and off on each TV in the bar (of which there are usually many different brands and models, none of which use the exact same controls). * Sports referees already use many clear and distinct hand signals for calls, from strikes and outs in baseball to penalties in football and hockey. * And finally, most sporting events can be fully enjoyed without announcers. It's akin to watching a game in person live, and it's the preferred way for a lot of people to take in the action. For on-field announcements, modern television graphics handle most all of the information not immediately obvious to someone watching.",
"Because sports commentary is absolutely useless. \"He's fast\" / \"he needs to be faster\" / \"he's not that fast\"",
"In the UK at least I've seen captions on sports games in bars. But not always, and it could be because those shows are live and captions aren't always fast enough and with high enough quality to be coherent.",
"the \"Captioning Window\" created when you have the [cc] turned ON, Could possibly Obscure / Obstruct the picture on the screen during an extremely critical in the game or whatever other sport.",
"it blocks the scores displayed on the screen sometimes. And i have never been refused when i ask to have a tv sound turned on, that is why i came, after all. Just ask!",
"My boyfriend is hearing impaired, so when we have people over he will mute whatever game he is watching so he can hear the people around him speaking. The captions will cover the score, inning, yardage, and/or the scores of other games. Not hearing the games kinda drives everyone bonkers, but they understand that it makes him more comfortable."
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jubmry | why does every charger i buy for my iphone break almost immediately after purchase? | Technology | explainlikeimfive | {
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"text": [
"Try getting the ones sold by Anker. It's a little more expensive than most cables, but still much cheaper than the actual Apple cable. You can find them on Amazon."
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juc3ke | How is the internet able to work... like that? How are we able to store so much on the internet and stay connected almost seamlessly? | The concept of the internet is always so bizarre to me and It's still a little hard to understand. How is it able to store so many things and have it be accessible to everyone? How are we able to be connected so quickly? | Technology | explainlikeimfive | {
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"Companies like amazon are where most of the \"internet\" is. In short, the internet is just a giant web that connects a bunch of computers together. Just like you can search through your own computer files to find the song you're looking for, you can search through \"other peoples computers\" to find webpages like facebook and the such. Internet companies like comcast are laying down physical cables that are doing the physical connecting of computers. It's part of why internet costs so much - those companies are constantly laying down more cables or new cables, and that costs a ton of money.",
"The internet is just the connections between computers (user computers as well as servers, etc). The actual storage is on servers, and storage space on a server is finite just like storage on your own devices is.",
"The internet doesn't store anything. Imagine the internet being a telephone for computers. In fact, remember dial-up? What happens is when you type in a web address or access the internet through an app or whatever, your computer essentially dials up the website's phone number; the internet connects your computer with a computer on the other side, and the two computers start communicating based on the input you give your computer and whatever the other computer was programmed to do. So information is stored on individual computers like your own (except of course there are lots of specialized computers owned by big companies that specialize in storing lots and lots and lots of data and work really really fast)."
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judax3 | How come homes and circuits are measured in Volts but appliances and electronics are measured in Watts? | Technology | explainlikeimfive | {
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"Volts is a unit of potential - it describes how energetic the electricity is. Watts is a unit of power - it describes the actual consumption of electrical energy We use volts in circuits because we are interested in the *signal* that the electricity caries. In circuits, watts usually comes into play when discussing how much energy a resistor lets off as heat. We use volts in houses because it describes a standard for \"how energetic\" the electricity is going to be, because our appliances need to know or bad things happen. We use watts in electronics because at that stage we are interested in things like cost of electricity or battery life, and so now *power* is what we are interested in, not signal. The relationship between the two is in the current, or the actual flow of electrical charge. When you scale the speed of a charge by the voltage applied, what you get is the power, in watts.",
"ELI 5 : Volts is what is given to the home, just like water is. It is just there till you use it. A faucet has water all the time just like your outlets in the home. In the case of electricity volts is water. Watts is how much energy is taken from the electric system, just as gallons is measured from a faucet. So in your example an appliance uses so many watts which is similar to a faucet releasing x amount of water. Safety note. Water and electricity do not mix well."
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judbjr | Why did it take such a long time for humans to invent electricity? | Technology | explainlikeimfive | {
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"To some capacity, its one of those \"no one stumbled upon it\" for as long as it took for humans to discover electricity. When you spend 100% of your day trying to find food, shelter, and mates, there isn't a whole lot of time left to contemplate the unknown.",
"There are a lot of things you have to have mastered in order to even *begin* to be able to experiment with electricity in any meaningful way. You need to have some metallurgy figured out in order to be able to test different metals' conductivity, for instance. And to make dielectrics, and batteries, and so on. So, you have to know how to purify metals like copper and zinc. To figure out electromagnetism and magnetically induced current, you've got to have magnets to play with, *and* wires or filaments of those conductive metals. The ancient Greeks didn't have most of these tools at their disposal yet, but they did figure out that rubbing certain things on certain other things would cause them to experience weird attractive/repulsive forces and make luminous sparks. So they were already *starting* to learn about static electricity. This was around 600 BCE."
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juhmen | Why are there many server in Singapore (online games, vp*, etc), but not in the neighboring countries? | Technology | explainlikeimfive | {
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"Malaysia and Indonesia have odd censorship laws, anti-privacy laws, and other regulation that make things a little difficult to use there. Similar deal with China. Australia has less of this but also has legendarily poor internet and is further from the rest of SEA.",
"Answer: If you look at the internet map, Singapore is an internet hub. Basically nearly every other region is connected to Singapore directly. Being a hub, Singapore also does not need to pay a lot for ocean cable upkeep, which is shared with all the other countries that use them. This allows Singapore to have faster connections with more regions, and also charge less in general. As of 2019, Singapore had the 2nd fastest internet speeds in the world following Taiwan. But Singapore has more network points."
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jui8zy | How can I connect a usb to ethernet adapter to my PC's usb port and it connects it to the internet? How does the PC know it's ethernet and not a keyboard? | Technology | explainlikeimfive | {
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"You attach a device to the USB port that handles the Ethernet communication. The device knows with is and it identifies itself by a [class code]( URL_0 ) There is a protocol when a device is connected when the device will send the Class to the computer. The computer knows that the class means because it is a part of the USB standard. It might have a generic driver for the device, it can download drivers by itself or let you install drivers. A keyboard is a HID (Human Interface Device) that have the base class id 03h. A hard drive, USB memory is a mass storage device so class 08h A wired network cand that use common RNDIS protocol has the base class EFh, sub class 04h and protocol 01h for wired and protocol 02h for WiFi, So the simple answer is that the device thell the computer what it is.",
"Because that's what the USB specification does--it defines how devices are supposed to communicate with the PC they're attached to. That includes negotiating what capabilities those devices have.",
"Basically the usb device talks to the computer when plugged in and tells it what it can do and what type of drivers are required. Then, in this case, it’s set up as an Ethernet port.",
"An ethernet card works the same way. If your motherboard didn't have ethernet built in, then you would buy an expansion card (similar to a graphics card) and this plugs into a PCI bus slot on the motherboard (earlier computers used an ISA bus). USB is also a peripheral connection bus. A **bus** just transfers bytes of data. Usually the data is divided into **control codes** which tell the device what to do and a data payload which is like a file to transfer. The USB device (flash drive or ethernet adapter) has a circuit board in it, just like the expansion cards mentioned above, and the **device driver** installed for the device knows what control codes to send to make the device function. Having the circuits directly on the motherboard just shortens the bus length, or how far electricity must travel to reach the device controller circuits. So short answer is they all work the same, they're just different ways to connect a device (with a **microcontroller** circuit integrated into the device which controls the device's functions) to the computer."
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jujpeh | why does smartphones don't choose the best known WiFi? They keep connected to weaker signals even thought there are better ones. | Nowadays Mesh routers are becoming extremely popular, although they cost quite some money, and one of their main advantage is that they all work in the same network, meaning that you don't need to save multiple SSID and passwords, also, they they manage which device is connect to which node so you can have the best possible connection. I'm in an environment that has two different networks and one has a weak signal while the other a strong one. If I came from the weak signal area, my smartphone will keep connected to it even though it has a better option to. So my question is, why it doesn't look for known networks to test they speed and chose from? | Technology | explainlikeimfive | {
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"> I'm in an environment that has two different networks and one has a weak signal while the other a strong one. If I came from the weak signal area, my smartphone will keep connected to it even though it has a better option to. > So my question is, why it doesn't look for known networks to test they speed and chose from? Because those networks *aren't* set up in a mesh. You said it yourself - if they were, it would work as you described. How chaotic things would be if your device always just connected to the strongest signal! You're transferring a file from your NAS to your mobile device, someone in the kitchen turns on the microwave and suddenly your transfer stops because your device decided to disconnect and connect to another network (which either doesn't contain the NAS or has completely different routing to it) just because - due to microwave interference - the original signal got a bit weaker for a second",
"This seems odd. I know for sure that iPhone does this In my home (even thought small, it has lots of walls and signal differs a lot from one room to another) we have 3 routers broadcasting the same SSID. I own a Note 10 and my wife an iPhone 11 and since changing all networks to the same SSID she haven't had the need to change between wifi ever since. I still need to reconnect to the strongest signal manually every time I go from my living room to my bedroom and the other way around."
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jun29u | What's the difference between a Lithium-ion battery and a cell cylindrical dry battery? | As title. It just amazes me that the average phone has a 3000-4000 mAh Lithium-ion battery is as small as a chocolate bar when a Roomba has a 3000 mAh cell cylindrical dry battery that is like 20 times bigger. If I swap batteries of those two, how will the performance change? | Technology | explainlikeimfive | {
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"> If I swap batteries of those two, how will the performance change? Your phone will instantly light on fire and the Roomba will not even budge, because one's a 3Ah battery at 3.7 volts and the other is a 3Ah battery at 14 volts. Incidentally, the latter has more than 3 times the actual power storage because power capacity is voltage times amp-hours to give watt-hours."
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junpxm | How does quartz assist in the function of a watch? | Technology | explainlikeimfive | {
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"It’s a form of time keeping. To keep time clocks need to measure from a constant frequency. In the past this has been done by measuring the constant electrical frequency of a mains circuit. Quartz has a constant frequency when electricity is passed through it so the watch can read this frequency and then calculate the time. It vibrated 32,000 times a second so the clock knows for every 32,000 vibrations it needs to count up 1 second.",
"If you put electricity through quartz it vibrates at a consistent speed, and using the vibration you can keep the watch on time. They are generally accurate to within 15 seconds a month. High accuracy quartz watches adjust for temperature changes and are accurate to 10 seconds a year.",
"Quartz is a piezoelectric crystal. This means if you flex it, it generates a tiny voltage. And if you apply a tiny voltage it flexes. If you make a tuning fork out of a quartz crystal and apply a voltage, it will vibrate at the frequency of the tuning fork. By cutting it the right shape you can get a very specific frequency. Dividing the frequency down can allow you to count seconds. A typical frequency might be 32,768 cycles a second. This happens to be a number that is very easy to divide using electronic circuits to one pulse per second. The watch simply counts those pulses and keeps time.",
"Have you even use a tuning fork that vibrates when you hit it and produce a specific tone? A quartz crystal oscillator is just like that, the can actually be like [small tuning]( URL_0 )[ forks.]( URL_0 ) They will vibrate 32768 times pre-second so to high-frequency sound for a human to hear it. Some crystal-like quartz produces an electrical voltage when compressed and if you apply a voltage over then they will expand. So you use the vibration and the electrical effect of the vibrating quartz crystal to produce an electric signal at 32768 Hz. You can if you are clever both power the crystal so it vibrates and gets out the frequency it vibrates at. 32768 is chosen because it is multiple of 2 is 2\\^15 to be exact. The binary digital counter is simplest to do in multiples of two. I suspect that it was chosen because you'd humans can hear up to 20 0000 Hz. So you take the lowest frequency human cant hear to make the manufacturing simple. You can make quarts crystals that oscillate at a higher frequency a couple of million times per second is common but not required for a clock. So it is a miniature quartz tuning fork that vibrates and the tone that is produced is electrical use to count time.",
"In most watches it doesn't have a function, but in quartz watches? To create power in quartz watch movements, a battery sends an electrical current through a small quartz crystal, electrifying the crystal to create vibrations. These vibrations keep the movement oscillating and drive the motor to move the watch hand So it effectively acts as a conduit for power, Quartz crystals maintain a precise frequency standard within its movements, which helps to regulate the movement of a watch or clock, thus making the timepieces very accurate. Quartz is also used in radios, microprocessors, and many other technological and industrial applications. But most if not all require power to be put into the crystal. But there are investigations into useing crystal quartz to create power but there are still a long time away from crystal engines edit (decades)"
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junukn | How does YouTube have enough storage space? | Technology | explainlikeimfive | {
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"Short, simple answer. They have a bunch of huge warehouses that look like [this.]( URL_0 ) Each data center can hold 100's of millions of gigabytes of data. The largest data centers in the world can hold around 1.5 billion gigabytes. To put it scientifically, they have several metric fucktons of storage capacity.",
"Data storage is not nearly as expensive on a per-gigabyte basis as you might think. Technology is continually driving down the size and cost of mass storage. Companies like YouTube maintain massive data centers for their media storage. Those data centers are frequently upgraded and expanded as new technology becomes available.",
"What's really going to blow your mind is when you think about how much storage capacity Alphabet owns for all their properties like YouTube, Google, Gmail, Google cloud, AdSense, Hangouts, Google Maps, Google Earth, Google drive, Google Translate, Google Wallet, Google Play, Picasa, Nest, Waze, Google Images, Google Voice, DeepMind, Google Analytics, etc, etc, the list goes on and on... It's unimaginable how much storage capacity they own. I'm curious if there's an official number.",
"**Compression, compression, compression.** Like some other people said below, storage is relatively cheap on such a massive scale, but the real key is making each video take up the least amount of space possible. YouTube has many specialized engineers who spend tons of time perfecting their proprietary compression algorithm. It is very good, and leaves very few compression artifacts while cutting the size of videos by as much as an order of magnitude or more. I would suggest you watch [this video]( URL_0 ) by MKBHD that explores what happens to a video when you upload it 1000 times over through YouTube’s compression. Edit: to answer your second question, improvements in compression are almost certainly the route that advancements in data storage will take. As of right now, we sit on the cusp of an exciting new age for compression. AI and neural networks will vastly improve modern algorithmic compression and will be integral towards serving our increasing need for data. The premise for this is far too complicated to be reasonably explained in a single Reddit comment, but [this video]( URL_1 ) by Nvidia helps show the potential of AI in video manipulation. Much of this same technology can be applied to compression and lead to new nearly lossless compression techniques.",
"This is a few years old, but lays good groundwork for estimating. [ URL_0 ]( URL_0 )",
"Short answer is they just have a lot of space and compress all uploaded videos. If you've ever held a hard drive, it can fit in your palm and probably stores 1-5TBs or 1000+ hours of video with YouTube's compression. Google has warehouses 100 sq meters where they can stack millions of these together in multiple places across the world. They just actually have that much space.",
"Economies of scale. Google gets to use their own infrastructure, so they can get the cheapest possible storage there is. Really few people actually upload videos that large, and having the small ones stored just once or twice(+ a few times on content delivery network for the currently popular ones) is enough for those hundred million views. Additionally if you notice, youtube uses some pretty heavy compression, even same resolution videos have lots of visual artifacts for detail-heavy videos.",
"Yeah, I remember back in '97 working at Cray Labs, we worked it out: we could back up the whole internet on 2 T-90 super servers.... Ah, the good ol' days...",
"Few things (and addressing your update question). Let’s start at the software layer and work our way towards the hardware. 1. When you upload a video, the single best way to reduce space is to not save it at all. After encoding the video into a compressed reference format, YouTube looks for other copies. If another copy exists, yours is deleted, or the better one is kept. This is transparent of course. To you it looks like you uploaded a video. A huge number of videos are duplicated. Even if your video is a part of another video, it’s good enough to throw yours away. 2. Compression. Compression gets better over the years. It’s a great thing that the latest compression technology is keeping up with the extra video quality. Remember, this is YouTube, not a movie studio. They don’t need to keep lossless videos. It just has to be good enough for people to not complain. This means a LOT of compression. 3. Recompression . As new algorithms come out, YouTube goes back over their videos and decompressed them with the newest software. 4. Storage improvements. Hard drives, despite being eclipsed by SSDs, are still improving. As of May 2020, you can buy a single hard drive that will hold 16 gigabytes! So while YouTube gets more content every year, the doubling of video hours doesn’t mean the doubling of hard drives, especially when you consider the compression is also improving. 5. Purchasing power. Google is stupid rich. They get the absolute best price on storage you can get in the world. They are the fifth largest PC maker in the world and don’t even sell PCs. They also use this purchasing power to buy land where power is cheapest, like next to hydroelectric generators. They pay way less for power than you would think. 6. Caching strategies based on usage. If a video is popular, Google has many many copies of it on its thousands of servers. As it declines in popularity, it keeps less and less copies. Eventually a video that hasn’t been seen in years will drop to just a relative few. 7. Removal. Sometimes videos are removed by the uploaded or by legal challenge. This happens more than you might think. Most people want to upload clips of things they’ve seen, not create original content.",
"There are people who do nothing else than setting up new harddisks. In this minute they are swarming out to install new discs everywhere.",
"About a year and a half ago, Youtube indicated that they receive ~30k hours of video per hour. At, very roughly, 2.2GB per hour of average 720p video (not everyone is uploading 1080p or 4k video, but some are!) - that’s about 65TB of video data per hour, or 1.5 petabytes per day. About 47 exabytes per month. An exabyte is a billion gigabytes ...",
"Imagine a warehouse and how big it is. Now fill it to the brim with storage drives. Also keep in mind they don't need to store EVERY video at EVERY warehouse. If there is a 2 hour long video in french and is only viewed in France and only viewed like 200 times, then they can store it only in a french server. If there is a really popular trending video, they can store that on every server."
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juu4nk | How does Google know my actual location when I'm using a VPN but YouTube allows me to watch region restricted clips at the same time? Shouldn't they both be "fooled" into thinking I'm at the same location? | Technology | explainlikeimfive | {
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"Youtube figures out your location from where your internet connection is coming from. A VPN masks this. Google will usually base your located on your GPS location, not your internet connect. The VPN does nothing to mask this. And even if you are not using GPS, they can still get your location from the nearest cell phone towers. That information is also not changed by the VPN."
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juz5dt | What is it that makes it so computers can't solve captchas? | Technology | explainlikeimfive | {
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"It requires image recognition capabilities that don't yet exist outside some advanced machine learning laboratories. Asking a computer to look at a cluttered image of a street corner and identify a fire hydrant is not something it is going to be able to do unless it's had a lot of practice identifying fire hydrants from multiple angles, zoom, color, etc. Humans are able to solve them because we process things differently. We can look at that image and process that fire hydrant, based on prior knowledge of what a fire hydrant looks like.",
"There are a lot of factors, but one of the biggest ones is called the [curse of dimensionality]( URL_0 ). Interestingly, the curse can be applied to captchas in multiple ways. For the oldschool kind, where you're transcribing random distorted strings, the curse was applied by increasing the number of unrelated distortions that got applied to the text. Each unrelated distortion is effectively a dimension, and so the more you have, the harder it is to build a dataset to train a machine learning model to solve the captcha for you. The problem with this approach is that the dimensions aren't random, so it's possible to identify the sets of distortions in common use and to train models to target them. After the oldschool kind came the \"help feed our machine learning efforts\" kind, where you'd do things like selecting all of the photos that contain street signs. These ones were based on correlations rather than the curse of dimensionality. Other people would be fed the same photos you saw, and if you agreed with them, you're human. The problem here is that those tests were a pain in the ass, and poor UX is a no-no. After those came the more modern style of simply clicking a box that claims you're not a robot. This is a return to the old style of relying on the curse of dimensionality, but this time in far more subtle ways. Modern captchas monitor everything they have access to, mouse movements, keystrokes, timing, the angle you're holding your phone at, everything. And all of that feeds into the machine learning model that distinguishes between robots and people. How many factors go into the exact timing of your keystrokes? The exact path of your mouse towards the check box? The location at which you click and the duration for which you hold down the mouse button? All of these are dimensions (and in most cases more than one dimension each), and it is the expanse of that space that creates room to learn a difference between the behaviors of people versus robots."
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