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gsp3sn
|
why are people so against automation in factories if it makes things safer and produces more goods? is it just that people are losing jobs? but there are different jobs that open up.
|
Technology
|
explainlikeimfive
|
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"Often there are different jobs, but not the same amount. Picture a factory with 10 workers. They replaces those 10 people with a machine. The new jobs that will open up will be machine maintenance, which is 1, maybe 2 roles? Potentially the machine does so well that it's started to increase the workload. So now the company might need an extra person when the goods come in and one when the goods go out. So you created 4 roles, which still leaves 6 people out of work.",
"This has been happening since humans started creating tools. The problem for the people complaining is that, yes, jobs will open somewhere else, but that doesn't mean that the same people doing the old job can transition to the new one. Think professional drivers. They're a huge part of the workforce and they're due for extinction. Yes, in that time most likely more tech jobs will open, but it's kinda difficult for a truck driver to become a developer. In the long run society overall benefits from productivity improvements (we no longer have 60% of people working in the fields, for example), but the people caught in the transition don't.",
"No, there are not. A human that is qualified to supervise or maintain one robot will always be in charge of many robots. A robot that is good enough to replace one human will always replace many humans. Think of it like a triangle: the base of the triangle is much wider. The base of our triangle are low level (in qualification) workers, and they are the majority of us, and they are the ones getting replaced by robots. Even if automation creates new jobs in the middle of the triangle, it will never be close to the same number. In my opinion a better solution is to move away from the notion of needing a job to live, because automation means we can be productive without working.",
"You're assuming the same number of jobs will be created as those lost and they will be of the same quality. Many people believe this is why, despite the massive increase in productivity over the last 50 years, wages have stagnated. The new jobs tend to be poorly paid and have little security.",
"Shortsightedness. Human resources are the one limiting factor of everything. By freeing up human resources with automation, they can be invested in things that still require humans. The problem is that this hurts the particular human in the short term, but benefits every other human in the long term.",
"It's largely based on the \"lump of labor\" fallacy, that if you get rid of a particular job that the same number of people will be unemployed, as opposed to having alternatives now/eventually become available.",
"Higher level of job which a person with low education who just cuts metal for example wouldnt be able to move up to become a machine maintenance bloke. Would have to find another factory that doesnt used automated machines",
"Learntocode all over again Jobs open up, but not in the same field. You can’t expect all the jobless to learn a new vocation. Not all jobs are entry level. Many jobs require skilled labor and that skill is not easily acquired."
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gsqbli
|
how do random number generators work?
|
Technology
|
explainlikeimfive
|
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"There are 2 types: RNG (Random number generators) pRNG (psueduo-random number generators, which try as best as possible to generate numbers which have similar properties as random ). An example of an RNG is a real life dice. Other examples are coins, wheels, etc. Can you REALLY make something truly random in a computer? Many will say no, but you can get close. There have been some examples listed in other posts here. Others examples are: the stock market price, radio-magnetic readings, etc. Most random behaviour in computer programming is using pRNG Let me give you an example of a really simple pRNG. Let's say you want a random number between 1 and 10. As suggested in other posts, what's important to random numbers is a \"Seed\". Think of a seed as the angle you are rolling your dice at. If you throw the dice the exact same way, it should give you exactly the same result. It's the same as a seed, the same seed will give you the same result. A seed is what gets you started. My method will be: - write the current time as a number (including the seconds) - add all the digits together - if that number is greater that 10, add all those digits together - repeat until there is a single digit. - add one to the result. So let's take a seed of the time. The time at the moment is 12:58:44 so ill just say my seed is 125844. Then ill add all the numbers together (1+2+5+8+4+4) = 24 The number is greater than 10 so ill add the digits together. (2+4) = 6 6 + 1 = 7 my result is 7 So, this is a legitimate pRNG, it generates numbers between 1-10. It may not be a very GOOD one, but it gives you an example of one. Now, real world pRNGs use much more complicated math, generally involving large prime numbers, modular arithetic and bit shifting (I wont go into those, but if you have grasped the general concept, you might be interested to google those)",
"They don't really generate random numbers, but rather take one number (say, the local date down to the current second), then run that through a variety of mathematical operations (square it, half it, multiply it with the currently used amount of RAM or whatnot), and then trim it down to the desired length. Again, it's not genuinely random as this strictly falls out of a computer's ability, but after pulling the starting number through so many different operations, the outcome might as well be.",
"As others have said, 'truly random' numbers cannot be computed. The computer instead measures something chaotic in its environment, such as electrical noise, atmospheric fluctuations, radiation detection from a Geiger counter, etc. *Pseudo-random* numbers can be generated by algorithm however. There are many possible algorithms offering different properties: the amount of numbers generated before repeating for example; speed of algorithm, etc. An example of one simple algorithm is the 'linear congruential generator', which basically brings out the natural randomness in the divisibility properties of integers."
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gsr1wb
|
Why do plugged in chargers, which aren't connected to anything, still draw power?
|
e.g. If a phone charger is plugged into an outlet yet has no phone connected to be charged, why does it draw power?
|
Technology
|
explainlikeimfive
|
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"text": [
"The charger itself has circuitry that needs to be powered. It's very little, though. Mostly just to detect when something has been plugged in so it can turn on. Much like a TV needs to be on to read the \"turn on\" signal from the remote.",
"Are you saying that because you have measured it, or because you believe that to be true? The no-load consumption of a modern switch-mode power supply (and all chargers are switch-mode) is very low, and below the ability of the typical domestic power meter to measure. A test here [ URL_0 ]( URL_0 ) managed to find 0.3W when connecting six chargers, three laptop, three phone/tablet, so an average of 0.05W each. This is ELI5, so... Imagine it's a hot day, and you want to keep a water bowl for your dog filled up, so there is always something him to drink. But the only water supply you have is a fire hydrant. You can fill the bowl by flashing the hydrant open for a fraction of a second. If your dog is drinking a lot, then you need to do that quite often to keep the bowl full. But if your dog is off doing something else, you will only need to let water in from the main very occasionally, as the bowl dries out on a sunny day. That's how a switch-mode power-supply works, It lets mains electricity in for a short period, to fill a bowl (a \"capacitor\"). If something is plugged in (\"the dog is drinking\") it has to repeat that process frequently. But if nothing is plugged in, then it only has to make up the losses caused by the capacitor leaking. Most of the \"vampire power\" nonsense stems from people who think that power supplies are transformers. They were, thirty years ago, but today they're all switch-modes (the \"flash the mains, charge a capacitor\" process). I don't know about the US, but in Europe there \\_is\\_ a transformer in a power supply, because you have to have galvanic isolation between input and output for safety reasons, but it's not being driven while the capacitor is full, so its efficiency is almost irrelevant when there is no load."
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"url"
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[
"url"
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gssn7c
|
what are licenses on operating systems?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"As /u/Skatingraccoon says its the thing that allows you permission from the vendor to run the operating system. However, you may also be thinking about open source licenses like when you open your smartphone's About/Software screen. In that case, open source software is software that is developed by community members (and sometimes corporations) but is freely available for use by all, with the one condition that if you DO use that software in your not-free software product, you have to disclose its use and provide evidence that either you are using that source code unaltered in your product or you provide your altered/derived source code back to the community. For example, any \"smart\" device like a smart media device or a home wifi router that has a webpage where you configure it has a built in webserver. If I were to use the popular open source webserver Apache in my product, I would have to disclose that I am using it. I can't just use the Apache webserver, slap my branding and logo on it and then charge lots of money for it."
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3
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gsud6j
|
What’s the methodology behind the X,Y,B,A buttons with Red, Blue, Green, Yellow colors on most video game controllers? Is it just aesthetic, or is there something behind those specific colors and letters?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"If you go back to the NES, you just had A and B. The Sega Genesis launched in 1989 with an extra button. They had A, B, and C in a line. The Super Famicom (essentially the Japanese Super Nintendo) released in 1990. They had four buttons, A, B, X, and Y. If you tried to make four buttons A, B, C, and D, you can't really intuitively know where C and D are relative to A and B. Are they parallel and in alphabetical order, or are they clockwise? Later in 1993, Sega released a 6 button controller for the Genesis. This had 2 rows of 3 buttons, ABC and XYZ, solidifying that two rows of buttons should have a disconnected lettering. As for the RBGY, they are the 4 most simple and distinct colours you can use. Trying to change, for example, yellow to purple will result in a clash with blue."
],
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3
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[
"url"
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[
"url"
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gsuh03
|
why .ini (or other config) files exist if they are just plain text?
|
I mean just a .txt would suffice, right?
|
Technology
|
explainlikeimfive
|
{
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"Convention. You can rename config.ini to cheeseburger.avi, as long as the content structure remains the same and the program looks for that file name, it will work. However, in IT culture this is considered a dick move, so people simply don't do it.",
"Technically yes, but functionally no; .ini signals to the program that this is a configuration file and it should read it in and do things, and handle it differently. A .ini file is just a plain text file, yes, but the extension means something specific.",
"Yes, but no. An INI file can look like plain text, but there's a standard for how to format it. It will have sections, with keys and values. It may look something like this. [Owner] name=Xelopheris role=Developer [Server] address=192.168.1.1 port=8080 An application can use a pre-existing library for parsing the INI file contents to find things in it. Using a new extension was a way of indicating that it isn't just regular text. Someone going in and adding data to it that can't be parsed could break the parser and render any programs that need it unusable. It also allows people to setup custom rules for how their OS tries to open the file. If you opened just a .txt file, it's no different from any other. If you try to open a .ini file and it opens in a different manner, you're less likely to try and fiddle with it and corrupt it.",
"You can name any file in any way you want. You could rename a .jpg to .txt, or a .ini to .q94y. File extensions are just one way to keep track of *how the file is to be interpreted*. So \"ini\" ist just saying \"this is a configuration file (with a specific format)\". While all valid \"ini\" files contain human-readable text, not all text files contain valid data in the \"ini\" format - so that's useful additional information to keep track of.",
"If you get down to it, lots of things can be stored as a text file. Even an image could be rendered as text, since pixels can be represented as numbers. [Video example]( URL_0 ) Having different file types helps tell computers what to expect when they open it. To use an ELI5 analogy, a school book and a newspaper are both just words and pictures on paper, but we call them different things and treat them differently because they serve specific purposes. Edit to add: Most of those config file formats also have specific format requirements, which some editors will try to enforce based on the extension. A lot of config files use JSON, which has strict syntax requirements. If I open a .json file in an editor like Visual Studio code it will know it's supposed to be JSON and warn me if things are wrong, but the same won't happen if I open a .txt file that happens to contain JSON content."
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gsw569
|
Why do audio recordings have static in the background when there is no sound?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"There's a thing called \"signal to noise ratio.\" A recording device introduces a base level of \"noise\" as a result of the recording process. When you're recording a loud sound, that noise is minimal in relation to that sound. When you are recording a quiet sound, the noise is relatively much greater. If you then increase the volume of a sound that was very quiet when it was recorded, you will also increase the amount of noise too. A sound engineer can erase static when no sound is desired, but the whole signal chain (cables, speakers, transmitters, or whatever) may also produce noise along the way and that noise will increase when you turn the volume up high.",
"A quick and simple answer is: It depends upon the medium being played or the source for the medium being played: For tape which uses varying degrees of magnetism to record and reproduce sound there can be particles on the tape which intefere with the magnetic strength, or which are themselves magnetic but which are not a part of the recording magnetism. Tape can be both the medium being played, or the medium which was re-recorded from. For records the needle sits in a grove, this grove is smooth until the needle gets to the recorded music (known as the lead-in) and the music is reproduced by the needle being thrown back and forth (in an angular fashion, but that is less important for this) and this manipulates a magnetic field. Dirt, or dust, will produce crackling sounds as the neddle hits the particles. Also, some records were pressed from a very poor quality vinyl (unsold records were quite often recycled) which flaked due to its poor manufacture which would produce a crackling, rough,almost scraping sound. For digital mediums, it is quite often the case that they are re-recordigs from tape and records, rather than recorded digitially directly, so you are hearing the frst two reasons above. You can get electronic inteference from poor or failing circuits which may also produce 'noise' on a direct to digital recording. Lastly, noise picked up by microphones and guitar pickups (the equivalent of a micropphone) can pickup background noise. I'm not talking about anything you would really notice in every day situations, these noises are so quiet that the average adult ear cannot hear them at all, but microphones and picups are very sensitive in order to be able to collect a massive range of sound not only in tone, but also in volume. So, they may pickup th minutest sounds like wood settling on a newly moved piano, or a room where the temprature has changed significantlym. Well, that's my blah-worth on th subject. I hope it helps."
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gswq3i
|
How do games render particle effects so much faster than programs like after effects?
|
I understand that while games have preset effects, programs needs to calculate every particle. However the games particle effects arent the same everytime which I guess means that each particle is also calculated. How is it that a game like overwatch can calculate tens of effects more than 60 times a second while the same computer takes a minute to render a simple particle effect?
|
Technology
|
explainlikeimfive
|
{
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"Part of it is the hardware used. Every computer has two main pieces of hardware which calculate things, graphics (gpu) and central (cpu). Each are specialized in some kind of processing and have a performance advantage at it. This is like having both a sedan and a truck. While both can take you shopping, a sedan is easier to park and the truck can carry large objects better. Going to the mall may work better the sedan and going to a home improvement store may need the truck. How programs leverage those resources is up how they are written. More recently, programs do a better job using the GPU when available and can spread the load across both accordingly, but games surely do have on average a larger focus on the GPU than other programs. It just so happens that the GPU is generally much more efficient for particle physics. The other part is how the particles are created and calculated. Games cheat in a lot of places to make it fast, as a stuttering image is far mor noticeable and negatively impactful to the viewers experience than cutting corners in particle calculations and only having an ‘approximate’ version of what should happen. Given that after effects and the like don’t have this real time constraint, they can take their sweet time in getting everything just right. A really good example of where this makes a difference is in lighting. Games will do something like ‘hey here’s the sun, it’s bright, and these surfaces face the sun so they’ll be bright too’. This is most of the way there, as in an outdoor, daytime scene, the sun is the brightest object. What it misses is that all surfaces reflect light to some degree. Mirrors obviously reflect a lot, but every object you see does too. That’s why you can see it. Calculating how bright something should be based off of not only the sun’s direct light, but also the faint reflections of everything around it gets to be very complicated. If you want to get it really close to accurate, that computation takes a while. If you want it to be live, you may only get to 90% accurate. After effects will start from how accurate it needs to be and work backwards for how long it will take, where the game will effectively work the other direction and set the time you have and cut corners to get something in that time frame."
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gswtkr
|
Why can't we vote in elections with a public/private key pair similar to how we log into servers?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Tom Scott has a good video on why electronic voting is a TERRIBLE idea. Essentially it boils down to this: any computerized system is breakable. It's only a matter of the time and resources an attacker is willing to invest to do so. Swaying election is an extremely lucrative endeavor for someone who would want to do so. It could be worth potentially billions of dollars. Given that US politicians run multi-million dollar campaigns to get elected (Obama won on a $400 million dollar campaign), we can say with confidence that an election is worth at least that amount. Another nation might consider a specific election outcome to be in it's own national security interests, and therefore worth an un-quantifiable amount of money. It is very fair to say that investing millions if not billions of dollars to adjust the outcome of an election is 'worth it'. Ergo, any election will probably be hacked. Pencil and paper ballots can be subjected to fraud too, but those types of fraud don't scale the same way an electronic attack could. URL_0",
"Note: I'll compare your suggestion to traditional paper ballots, voting machines have a [lot]( URL_1 ) of other [problems]( URL_0 ) I won't be addressing. We could, but it wouldn't really solve the problem of a fair election. A public key is used to identify you, and you only - the state could easily see who you voted for, which is something you might not want. There *are* some cryptographic schemes that would allow anonymous voting (\"homomorphic encryption\" and similar things). But there are still some fundamental problems with that: - Trusting the vote would require trusting advanced cryptography (and that it is implemented correctly!). Having only a small number of people able to verify that your election is fair might be a problem. In comparison, a paper ballot is much easier to understand and monitor, and much harder to manipulate on a very large scale - The government would need to issue your key in the first place, requiring verification that you are eligible to vote. Documenting all issued keys publicly, in a way that would allow people to verify there aren't any fraudulent ones, could be hard - Not everyone has access to the internet, and is able to use a computer. This might also enable voter fraud by misleading a less tech-savy person into voting for the wrong guy - Maybe the worst one: Malware on your computer could manipulate your vote. The public key scheme doesn't prevent that - your computer needs to have access to your private key at some stage (assuming there isn't any additional hardware device involved, which again would need trusting), at which point the malware could just switch your entered vote."
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[
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gsyq4y
|
Why do CCTV cameras have seemingly such low picture/video quality in comparison to something like the basic camera on your phone
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Higher picture quality causes rapid increase in data storage cost. Going from \"TV\" at 500-ish lines to iPhone at 12MP (3K lines) requires 36 times as much storage space per frame. Paying 36 times more for footage that is never used (ok used 0.0001% of the time) isn't worth the money.",
"It all comes down to money. First, save on the cameras themselves. Lower resolution cameras cost less. Second, save on storage. If your CCTV system is going to save the video to disk for any length, you have to realize how much disk you'll use. A 30 day retention means 720 hours of footage. If it was encoded at 720p, you could require ~20TB a month for storage per camera. If you drop it down to 480p, you can get to the ~5-8TB range easily. This is per camera. Imagine a system of 10 or 15 cameras, and suddenly you are managing a lot of data just for security cameras. Drop the quality to drop the storage requirements. Third, a lot of CCTV systems were deployed many years ago when those were still relatively high quality cameras. Inexpensive high definition cameras are relatively new."
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gt073j
|
Why do news reporters have to deal with the several second delay when talking to someone remotely? It seems like it can’t be the tech, I mean there’s no delay on my cell phone, so does it have something to do with censorship?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs8hq5k",
"fs8i1bd",
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"text": [
"Remote reporters are often using trucks with [microwave emitters.]( URL_0 ) It's like talking on an old-school CB radio, not a phone line.",
"There actually is some delay on your cell phone, you just won't know it unless you're in the same room with the other person. If you try standing in a room with a friend and talk to them on your phone, you'll see that the sounds you hear coming from them are immediate as compared to what you hear through your phone. This is due to the signal being sent through the closest cell tower before it gets back to you. From a television news perspective, the signal would have to travel a greater distance --- the limiting factors being the speed of sound coupled with whatever sort of equipment is being used to transmit and receive the signal.",
"In designing a \"live\" communication like a cell phone, there is a tradeoff to make. You can have extremely high quality, but there is a delay so that all of the information can be sent and properly error corrected. Or, you can have lower quality, but less delay. A cell phone is one example, but a single channel of voice is not a lot of data to transmit. Something that needs more data is a video call, like on Skype or Zoom, and these do have a noticeable delay, but they also don't have that great of audio or video quality. The video quality used for newscasts requires over 1000x the data bandwidth of a Skype call (gigabits per second instead of megabits). Streaming this much data is often done over satellite links, which add a delay. Some of this bandwidth can be reduced if the data is compressed, but that also creates a delay, because the video must be compressed at the sending end, and decompressed at the receiving end. When the newscaster is on the other side of the world, often multiple different links have to be used, including satellites and undersea cables. Each of these paths adds time to the delay."
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"https://en.wikipedia.org/wiki/Electronic_news-gathering"
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[
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gt15b4
|
What is an API as it relates to software/computer science?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"An API is a portion of a program that's made to allow one program to talk to another. Let's say I wanted to write a desktop application that can operate the playback controls of Spotify, change the volume, etc. Spotify isn't going to let me just hook into their code directly because I could mess it up somehow. There's also the problem that my application may not even be written in the same language. The way around that is if the Spotify programmers make an API. It's a list of general commands that their program will recognize. So they could make a \"pause\" command that it can hear from my new remote control application and Spotify knows that my other program wants it to pause. It could similarly have a command to tell my program what's playing right now so my program could display it, just like if you yell \"Marco\" in a pool, someone knows to yell \"Polo\". Disclaimer: I don't know if Spotify has an API, I'm just trying to think of a plausible example that's not an abstract comp sci type of thing.",
"When we design computer systems we often distinguishes the interfaces into User Interfaces and Application Programming Interfaces. These are the different ways that others interface with our systems. A UI is what a normal human would use and have nice displays and buttons to push. This is very useful for a human to interact with however if you are programming an application that needs to interface with our systems then it is very hard to use the same interface that is designed for humans. So you would use an API which is designed for other applications to use. It tends to be a lot more formal and structural which is how computer software works. The data formats may not even be readable by humans at all or it may contain too much incomprehensible data for humans to understand.",
"An API is an interface that allows a programmer to use functionality of a different program. For example, let's say you want to write a website that shows you taco specials in a users area. Well you can write the maps by hand, etc or you can use Google maps, which has an API and let's you use Google's maps and search using them, etc. If you didn't go this route you would have to write a program that does all the mapping by hand, look up all the addresses, etc. By using Google, they already have this map system and you can just use that, so if I'm in New York City, you send The API my location. It returns you some info and you can do what you want with it (in this case show me delicious taco place nearby) Think of it as a way to use some functionality of a program in your own"
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3
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] |
[
"url"
] |
|
gt18j4
|
How does an optometrist's vision test (which is better, A or B) come up with an eyeglass prescription?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs8qj5b"
],
"text": [
"They are switching settings on a piece of equipment (called a phoropter) doing a type of binary search to narrow in to the right prescription for your eyes. The adjustments they make get smaller and smaller as they go past the prescription you need and eventually land in a place where you can't really tell much difference between the two options they're giving you. Your answers give them the feedback to know the two endpoints they need to check between. I am not an optometrist so this is my educated guess at to what is going on"
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gt2yoh
|
How come using an aux cord with a car charger makes a whining sound but charging my phone from an outlet and using earbuds does not?
|
When I charge my phone and play music in my car using an aux cord it makes an awful screeching sound that increases with speed. This does not happen when I charge my phone and use earbuds in a wall outlet. Why?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs90ufs",
"fs9a7fu"
],
"text": [
"Because a petrol(gasoline) car has spark plugs, which generate tiny spans to make the engine run These sparks generate quite a bit of electrical noise, the noise gets picked up by the charger, the phone and consequently the stereo, which amplifies the sound and makes it audible This also means that in a diesel car this shouldn’t happen",
"It's probably caused by a ground loop. This would likely fix it: URL_0 As explained by Amazon user Atman on the page: > Any device that uses the car AUX input and connects to power may get a loud buzzing that changes pitch as the car's engine speed changes. This noise is caused by a loop created by the two connections to the cars ground. This adaptor isolates the audio connection by using a transformer so that there is no physical connection to ground only a electrical connection for the audio, thus stopping the ground loop and preventing the noise."
],
"score": [
11,
5
],
"text_urls": [
[],
[
"https://www.amazon.com/Mpow-Ground-Isolator-Stereo-System/dp/B019393MV2"
]
]
}
|
[
"url"
] |
[
"url"
] |
gt32wv
|
How does encryption really work? What prevents hackers from just stealing the key and stuff?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs93wb4",
"fs943lz",
"fs99igb"
],
"text": [
"Computer encryption works by encoding the information into a meaningless data set(the Hash), which contains the same data, except in a secret code based on an algorithmically generated number. Some encryption schemes are REVERSIBLE, which means you can use the same key, or a related key, to decrypt the hash and get the information back. Others are ONE-WAY, meaning that encrypted data is essentially gone; this is a common way to store passwords, and you simply compare the hash values; if they match, they have the right password. While someone else will have to explain the finer points of how it works(I have only a very basic understanding of the methods involved), loss of control/custody of the encryption key is a major risk in most encryption systems. Especially since in almost all systems, if you lose the key, you can't decrypt the data, so you can't just destroy it and forget about it. In theory, a very lucky hacker, or a very powerful computer, could stumble upon the correct sequence to break an encrypted message, though its vanishingly unlikely. However, as computers become more powerful every year, and many encryption standards have latent vulnerabilities that are discovered after some time, encryption must be updated frequently to preserve the safety of the data.",
"The math behind this is quite complicated, so maybe someone else can fill that in, but I'll try to at least give an example. Most encryption on the internet is called \"public key\" encryption. If you want to send me something secret, such as a credit card number, you first ask for my \"public key,\" which I can give to you, or even just have posted on my website. It's no problem that anyone can see it. When you use my public key to encrypt the data, it now becomes unreadable even to you. Even though you have the data and the key, it was a \"one-way\" operation, and the only way to get the data out again is the \"private key,\" which I have kept safe on my personal computer. If we wanted to communicate back and forth, we would both create encryption keys, and then trade just our public keys. Now you can send me a message that I can read, and I can send a message that you can read. Other people who know these keys can *send* us whatever messages they want, but they can't open it without knowing the private key. One catch to this. Say someone was able to intercept our communications from the very beginning. When they saw that I was sending my public key to you, they jumped in and swapped it with their own public key. Now when you send a message to me, they jump in, decrypt it with their private key, read it, and then re-encrypt it with *my* public key, and pass it along to me. They were able to read the message without me ever knowing. One way to counter this, is to create places where anyone can post their public key in a very open, widely available fashion. That way, you can always check whether the key that you think is mine matches what is listed in one of these registries. When you go to a site that warns you \"this is not secure,\" that's one of the possible reasons for this error: the information being given to you by the website does not match what's posted on a registry. 99% of the time, it's because someone screwed up their configuration of the website, but in a rare case, it could be that something is trying to \"snoop\" communications to that site.",
"There seems to be lots of misconception about the math here. The math is simple. *Really simple*. But the computation is so expensive to reverse the keys, that we don't have computers fast enough to do that in a reasonable amount of time. Here's how it works: **Step 1** \\- Pick 2 prime numbers and have them multiplied. p = 7 q = 13 n = p * q = 91 **Step 2** \\- Compute the Euler's toient. φ(n) = (p - 1) * (q - 1) φ(91) = (7 - 1) * (13 - 1) φ(91) = 6 * 12 φ(91) = 72 **Step 3** \\- Pick a random number `e` such that it is: 1 < e < φ(n) 1 < e < φ(91) 1 < e < 72 and `e` is \"coprime\" with φ(n), meaning it has no common factors. e = 23 (because I said so). **Step 4** \\- Compute d, the modular multiplicative inverse of e (mod φ(n)): e^-1 = d (mod φ(n)) 23^-1 = d (mod φ(91)) 23^-1 = d (mod 72) 23 * d = 1 (mod 72) 23 * 47 = 1 (mod 72) d = 47 Now you have all the magic numbers you need: public key = (n = 91, e = 23) private key = (n = 91, d = 47) **Secret messages to you** **Step 1** \\- Have someone else encrypt a message m using your public key (n, e): m = 60 c(m) = m^e mod n c(60) = 60^23 mod 91 c(60) = 44 c = 44 (they send this to you) **Step 2** \\- Decrypt the message c using your private key (n, d): c = 44 m(c) = c^d mod n m(44) = 44^47 mod 91 m(44) = 60 m = 60 (now you have the secret) Now wait a minute. Did you notice how we mirrored the operation here? m(c) - > c(m)? If someone doesn't know `d` they won't be able to mirror the operation. They can do brute force, but it means they have to run at least 47 operations to figure out. With just a few tiny numbers its already complex to brute force. Computer software like OpenSSL and other cryptographic libraries generate massively large prime numbers and random numbers for steps 1, 2 and 3 making it insanely complex for someone to brute force it. This is all there is to it for the Maths part. It's *really* that simple. Now, others have explained how it's hard to"
],
"score": [
4,
3,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gt4cce
|
How can games spend several years in development but when released have modern graphics
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs9p7iu"
],
"text": [
"The games starting development today have graphics that are 5 years in the future from what is currently available. When they come out, they define what \"modern\" graphics look like. If the game developers guess wrong on how powerful computers will be, one of two things can happen: 1. Computers are more powerful than they guessed, and so the game looks worse than its competitors. 2. Computers are less powerful than they guessed, and so the game doesn't run well on available computers. A good example of a game where they didn't guess right is the original Crysis, which had graphics that were too good, so it didn't run very well on computers available at the time it came out. The game developers aren't just guessing in the dark, often they collaborate with the manufacturers of graphics cards who help fill them in on how powerful computers of the future are likely to be. Even if you don't have an insider perspective like that, you can make a guess about graphics card power based on how fast computer graphics have changed in the past."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gt7vfo
|
do zoom calls or any video calls show the most accurate representation of you (how people see you as) compared to say the mirror,selfies,photos from the back camera and videoing yourself?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs9xpnh"
],
"text": [
"Which camera you use shouldn’t change anything, except maybe resolution. If you’re taking a shot with a mirror, then you’ll appear backwards. In Zoom or Meet, and many others, you can see what you look like to everyone else in your own window. In Zoom, at least, it’ll reverse your image for you, so you’ll have the effect of looking in a mirror, but it sends the correct image to everyone else. This is to help you react correctly if you’re looking at yourself, as you probably see yourself in a mirror more often. Zoom also has a setting to “fix” your image, by softening it a little."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gt85vm
|
how do bladeless fans work?
|
Those fancy Dyson fans. How they push the air? Edit: thanks for the information. It's amazing the amount of thought that goes into a little fan.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fs9ztcm",
"fsahg4o",
"fsb2jne",
"fsa4cds"
],
"text": [
"They’re unfortunately not bladeless :/ There’s a small fan in the base of the fan that sucks in air at the base. Then the air is forced up into the bladeless portion and forced out of the narrow slits around the ring. This is the cool part because that tiny little fan isn’t enough for all that air to be pushed out of the ring. The ring is slightly tapered like an airplane wing. We take advantage of the coanda effect where the air likes to stick to the surface of the ring rather than mingle with the rest of the air. And it creates a zone of low pressure just outside the slit/ring. This zone of low pressure then coaxes passive air molecules behind the ring to flow forward in the direction of the rest of the air thereby increasing the air flow. They also take advantage of a phenomenon called entrainment where air flowing into our out of something will force adjacent air molecules to move along in the same path, thus increasing the air flow again. This results in a ton of air from a super tiny fan allowing you to go “bladeless”",
"After reading the other comments. The real eli5 is, small fan makes air go wooooosh. Thanks to the smart ppl on here with the proper answers",
"The 'ring' of the Dyson fan is hollow. Air gets pushed through it and out through a slit that aims at you from the back end of the ring. The 'ring' very closely resembles an airplane wing, which means air can flow smoothly over it. There's a small fan inside the base. As it forces air into the 'ring wing' and out through the slit, that fast moving air runs along the surface of the wing shape and also 'pulls' the air within the ring. The (relatively) small amount of fast-moving air exiting the tiny slit therefore becomes a relatively large amount of slow-moving air as it leaves the confines of the ring. Hence why it is marketed as the Dyson \"air multiplier\".",
"There's a regular fan underneath that draws air in and pushes it through a tube to smooth the flow. It's a compressor attached to a diffuser, essentially."
],
"score": [
346,
35,
15,
4
],
"text_urls": [
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|
[
"url"
] |
[
"url"
] |
gtcyyq
|
how can you get 100+ mbps internet through a single wire in a coaxial cable, while an ethernet cable need 8 wires to do the same thing
|
I fucked up the title, it was meant to say 1000 not 100, though "100+" still technically is correct🤷🏼♀️
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsasm78",
"fsarxtn"
],
"text": [
"Wildly different signaling methods An ethernet cable carries your signal down differential pairs and sends 1s and 0s by having pins that flip polarity. If it wants to send a 1 then TX+ is high while TX- is low, if it wants to send a 0 then TX+ is low while TX- is high. While the ethernet cable does have 8 wires in it, it wasn't until Gigabit ethernet that we started using all 8 wires, 100 Mbps ethernet only uses 2 pairs of wires in the cable. The 4 pairs are used so it can be talking on two channels and listening on 2 channels at the same time. Coaxial cables play by a whole different set of physics rules. They are not electrical cables carrying electrical signals, they are flexible RF waveguides carrying RF signals. All those fancy ways that your WiFi router uses to increase its bandwidth like using multiple frequencies or shifting the phase and amplitude to send messages, those don't work in digital systems like down ethernet wires, but they do work in analog RF systems and you can pump those down a coaxial cable perfectly. You could have an antenna on the roof of your house and it would pick up local station broadcasts coming in on specific frequencies. Well prior to digital everything, the coaxial cable to your house carried the same signals on the same frequencies. Instead of broadcasting their waves through the air, they broadcast their waves down a cable",
"Simply put:. Coaxial cable can do higher frequencies due to them being shielded,a thicker conductor, and different signal modulation. Ethernet can do 10gb if the cable is properly done."
],
"score": [
21,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
gtdh1b
|
How is it possible that we can't explore the remaining 97 percent of the ocean when NASA takes pictures of galaxies million light years away.
|
Technology
|
explainlikeimfive
|
{
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"text": [
"We certainly can. The Trieste has been down to into the Mariana Trench in 1960. In 2019 Victor Vescovo went 7 miles down into the water, and it is on the show Deep Planet on Discovery Channel. We just choose not to spend money to do it more often. We have mapped the ocean floor, and have been to discrete parts of the ocean bottom, and we can explore anywhere we choose to get the money to investigate. We just choose not to.",
"Most of the ocean floor is just sand and rock. That's about it. People don't really want to spend their money unless they are setting records (Mariana trench dive) or they are shipwreck diving for lost treasures (Billionaires hobby).",
"It's mostly a scale thing really. The Earth's oceans are massive. We're perfectly capable of going down there, shining light and taking a picture. We do just that. But just like how NASA is only recording an incredibly tiny sliver of everything that's out there in the universe, we're only recording a tiny bit of the deep sea every time we spend hundreds of thousands or millions on a research mission going down there. And nature is wildly diverse. If you go out into the woods, stick your shovel in the ground and come home with a neat square foot of Earth, a couple of inches thick. There's a good chance that little sliver of topsoil contains thousands of scientifically unknown mites, nematodes, fungi, moulds and so on. When we point a bit of our planet and say \"that's largely unknown!\" it's usually a combination of factors. The deep-sea is hard to reach and that makes it expensive to reach. There's not a lot of good reasons to go down there and that means few are willing to spend the millions it takes to fund a mission. A lot of deep-sea discoveries are actually made through the maintenance robots of oil companies and companies maintaining the intercontinental cables. They're the people who have a reason to spend the money to go down there.",
"Of course we *could*. There isn't just much to be gained. We know how the ocean floor generally looks geologically speaking, we just haven't bothered building a robot (or paying the money) to take high resolution pics of each square meter.",
"Because they’re two completely different things. All you need to do to take pictures of far away galaxies is essentially put a camera on a telescope and point it at the same spot in the sky for a long time. The light from those galaxies will reach that telescope regardless. You can’t do that with the ocean. You need to be able to build crafts that withstand gigantic amounts of pressure and you need to physically go down and look at the ocean. You can look at the bottom with a telescope or anything. Light won’t penetrate far enough.",
"There's mostly empty space between us and those stars we are staring at. Going the opposite way, there's lots of water that only gets heavier as you go down",
"The difference between the 1 atmosphere of pressure at sea level and the 0 atmospheres of pressure in space is much easier to overcome than the difference between the 1 atmosphere at sea level and the hundreds of atmospheres in the ocean (~1100 atmospheres at the bottom of the Mariana's trench). Also space is transparent so we can point cameras at it. Water blocks light after just a few meters.",
"There is basically nothing but a bit of gas and millions of kilometres of nothing between us and other galaxies. There's lots of water between us and the bottom of the ocean.",
"We can examine any point of the sea's floor that we want. Send out a sonar ship, send down a submersible. Spend a week there and you get really good pictures of that spot. It is similar to the sky. We can closely examine any point we want. We spent 10 days of hubble's time to take a deep picture of a tiny, tiny bit of the sky, a part of the sky that looked boring, and found it crowded with galaxies. Since then we have let hubble look a patch of the sky over months, and seen even more. But we haven't done that to all of the night sky. So it is a bit similar. We have examined small parts of both the sky and the ocean floor very carefully and learned a lot. But we don't really know a whole lot about either of them.",
"The general idea of pressure between the deep ocean and outer space is the following: In space, there is no atmosphere or air meaning we have to pressurize our space suits to acclimate to the environment of space. That pressure wants to go out and equalize with the surrounding space but we are able to keep it sealed in, preventing our astronauts from dying of rapid depressurization. In the ocean, all the water above a specific point is weighted down on that point because of gravity, when you're at the bottom of the ocean, you have the whole entirety of the water weight of the ocean above you crushing down on your position. As you can imagine, this weight is far greater than the pressure difference in space as while in space, the pressure is relatively constant while in the ocean it increases exponentially the further you descend. We do not have reliable equipment capable of handling those immense pressures all crunching in on the bottom of the ocean as delicate technology like in cameras will have to be heavily protected but still will have a big chance of collapsing in on itself because of the immense water weight pressure. I could have some misinformation but this is the general understanding I was able to remember.",
"Real question is what do you mean by explore? We have very detailed scans of the ocean floor. We have a very good idea what is down there almost everywhere. Yet we don't have a direct image of an exo-planet. Do we find lifeforms we haven't seen before... sure but you can say the same for the rainforests. Vast majority unknowns are slight variations of life we know of and that can be said of the near daily discovery of a new beetle. I think it is a total myth that we know more about space than the ocean."
],
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899,
194,
121,
84,
46,
35,
35,
6,
6,
6,
4
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|
[
"url"
] |
[
"url"
] |
|
gte57m
|
How do Captchas work and how effective are they in weeding out bots?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsb18tj"
],
"text": [
"Captchas original were just squiggly text. You may still see these. Computers aren't good at machine vision so they cannot read them but humans can. reCaptcha was the next generation of that, and they gave you two words to type. One was a control (they knew what it was) and they other, they actually didn't. They came from the Google project to scan and digitize books. The books were old and the computer couldn't read all the words so they used humans to transcribe for them. If 10 people agreed what the word is, and entered it correctly, then it was accepted as correct; in essence you're helping them digitize books The iteration where you have to tag images (click all images with a sign) is again an issue of machine vision and you're helping training AI and reverse image search The one where you click a box to merely say you're not a robot... though there are videos that show robots doing this, they're actually watching how the mouse moves along the screen, or measuring how the box is checked on mobile devices....such that they know a human did it, was not automated. I don't have figures for how effective they are at stopping bots, but they work. As tech evolves, they try to make the process easier, but also leverage it to help train AI to solve new problems. Luis von Ahn is the inventor of them (it was his PHd thesis and he's also the guy who invented DuoLingo...and the reverse image search). There are tons of podcasts and videos about him talking about the CAPTCHA and how it evolved and what the new goals are. Originally they were designed to just stop bots. But he realized how much time is being wasted every day on them so he retooled them to solve computer science problems. So now, while they stop spammers, they're really experiments in improving security and AI issues and each time you do one, you're helping train a system."
],
"score": [
13
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gtguqh
|
Why do tractor trailer trucks need help to extricate themselves when they are jackknifed? Why can't they just turn their wheels and straighten out on their own?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsblcz5"
],
"text": [
"The wheels on the trailer aren't powered. This isn't a problem when the truck is pulling them in a direction mostly parallel to the direction the wheels move, but the further the trailer turns the less of the force the truck produces is pointed in that direction. If the truck is pulling perpendicularly to the direction of the wheels, zero force is being applied in a direction the trailer can actually move, and so it won't. At that point no amount of turning the wheels on the truck will move it, as all the force the truck produces will be applied to the hitch, in the direction the truck is currently facing."
],
"score": [
39
],
"text_urls": [
[]
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}
|
[
"url"
] |
[
"url"
] |
|
gti2gd
|
Why do old recordings (tv / audio) sound so nasally?
|
Watching old movies or broadcasts always sound the same. Everyone has a very muffled and nasal sound to them. What caused microphones to produce such a uniformly weird sound?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsc2g12",
"fsbsy51",
"fscrgv8",
"fsdiwvk",
"fsc32a0",
"fscu4g1"
],
"text": [
"One factor is the recording media, which in combination with microphones can dramatically roll off frequencies at the top or bottom. Older recordings were on film, tape, or vinyl, which introduced their own artifacts like compression and graininess. You end up with a reproduction that is missing much of the nuance in human speech, like chest resonance and sibilance, so you get that nasally quality. It was also a factor in how broadcasters spoke, as someone speaking normally would not be as well understood.",
"Are you referring to the trans Atlantic accent? URL_0 If so it was a cultural phenomenon in the 30s-40s because it sounded like the way rich higher classes spoke so it became popular in media",
"The recording technology used at the time such as vacuum tube preamplifiers and tape recorders would introduce analogue warmth. The effect of this are, amongst other things, diminished high frequencies. Engineers at the time would apply boosts to the high frequencies to compensate for the loss.",
"People talked through their noses back in the day until mouths were invented in 1956 by Sir Edwin D. Mouth.",
"I'm no audio engineer, but I assume it's similar to dynamic range in cameras. Older tech, whether the microphones themselves or the recording side of things, couldn't accurately capture the full range of a voice (or anything else for that matter). Add on to that that there was likely a lot of noise in the system, especially in situations where you're pumping a big signal to broadcast the speech live (as in live to a ton of people, not live to air in a studio), and that's going to make things even worse.",
"Don’t forget there’s another reason. Reproduction at the time came via CRT TVs which rather than the modern integrated soundbars or high end 5.1 systems, actually came with weedy singular paper cones. These cones had poor slow response times, were tiny and generally incapable of producing low frequencies. As such, replaying a varied high-range soundtrack would be unlistenable on a period TV. To combat this, low frequencies were reduced and engineers tried to funnel sound through the frequencies that CRT speakers could produce clearly. With the advent of decent reproduction, these now sound hideous and date recordings badly."
],
"score": [
170,
48,
6,
5,
5,
3
],
"text_urls": [
[],
[
"https://youtu.be/Gpv_IkO_ZBU"
],
[],
[],
[],
[]
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}
|
[
"url"
] |
[
"url"
] |
gti6jw
|
How do livestream concerts work when the musicians are in different locations? How are the musicians able to play in sync without lag issues?
|
I’ve been dying to know. Thanks!
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsbuu8m",
"fsc8228",
"fscs61b",
"fsdb8ti"
],
"text": [
"If any of these concerts were perfectly live (i.e., straight from the performers) it would be an unrecognizable mess of sound. Generally the feeds from the individuals are sent to a production team who sync the feeds and broadcast the synced feed. So really there is an amount of delay between when the performers play/sing to when you see it. Similar to sports broadcasts",
"Basically you just play off the click track and backing track. It's a little secret, but many concerts are actually played exactly timed, each break between songs, song tempo and length, including start and ending. These events are highly choreographed to the second. Because these venues are expensive, the productions want to spend the minimum amount of time in them. The tear down starts before the last song has finished. This is achieved with lots of rehearsal and a click track. Now I'm not saying every artist does this, but this is the common way. A good rehearsed musician can play their part solo, without an issue. Then at the end they are just synced according to delay with the click, then the signal feeds are mastered and broadcasted with delay.",
"While all other comments are totally correct, and livestream concerts are usually being played against a metronome/click-/backing-track and produced by a production crew, there's actually some research going on with tools you may be able to use for \"distributed live music\". There are some guys at Stanford that created JACK and jacktrip ( URL_0 ), more aimed at jamming with friends than real livestream concerts, but they seem to manage latencies low enough that it feels like really playing live with each other. Just in case someone, like me, thinks of doing that himself...",
"Musican1 - > Send to Server; Musician2 - > Send to Server; Server Syncs Musican1 and Musican2 - > Server to Public"
],
"score": [
183,
25,
10,
3
],
"text_urls": [
[],
[],
[
"https://www.jacktrip.org/"
],
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}
|
[
"url"
] |
[
"url"
] |
gtjxwg
|
Why does video degrade over time? WHat specifically about video makes it degrade versus film or digital media?
|
I mean watching old sports replays, I remember watching them in real time and the video looked great (Not today's 4K great, but still), and now it looks like total shit. Were they really not very high resolution vs. today's cameras and screens?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fscehfk"
],
"text": [
"Film has no resolution technically. It can be developed and upscaled to almost any known resolution. Video does have a resolution. Your perspective most likely changed. You were used to video being a certain quality in the past and that was the best you could get by then. Now you are accustomed to hd/4k footage."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gtmagq
|
When going protesting why do participants need to disable their cellphone data and Face/Touch ID before they go?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fscvjw1"
],
"text": [
"In case of arrest, so that officers can not unlock their phones by pressing a handcuffed thumb against it, or holding it up to the face."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gtmtan
|
Why does IMAX images looks more sharp than 4K on an Full HD screen ?
|
I've been watching Dunkirk recently and learned it was partly shot on IMAX. I watched it on a basic Full HD screen. So to my understanding, "data" is lost when watching a film with resolution above Full HD on a Full HD screen right ? So, both 4K and IMAX, are "compressed" to the same resolution. But why do I feel like the difference is noticable ? I found Dunkirk soo sharp, so realistic and so detailled compared to other films.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsd5i3q"
],
"text": [
"IMAX film is 70mm wide and contains enough information to make 8K+ resolution images of each frame. Alas, that many images at that resolution couldn't be streamed to anybody. When you see a digital movie in a theater, they transport it by putting hard drives in the mail (actually a shipping company, but whatever)."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gtp5og
|
how could a computer with only 32k of RAM memory be enough to help landing on the moon ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsdftko",
"fsdg3dl",
"fsdikjh",
"fsdll1n",
"fsdosr8"
],
"text": [
"Because it was dedicated to doing that one task and nothing else there was no windows operating system, no antivrus software, no solitaire games etc.",
"Specialisation. That computer had a few specific tasks so it had as much resource as was required to achieve those tasks. Your modern phone in comparison is far more powerful, but also can handle calls, texts, Internet access, games, photography. Plus think about failure points. The kit on the moon landers had to work, almost perfectly, the simpler the item, the less likely for a fault to sneak in that is missed in testing. That being said, the on board computers were far from simple, have a look on YouTube for the Apollo guidance computer restoration project.",
"To add to what others have said, all the computer was doing was math. Actually simple enough math that it could be done with a pen and paper if given enough time. The computer received data from instruments in the form of numbers and performed simple equations that then spit out a different number. That number was relayed to the crew, the ground control, or another instrument that does nothing but respond to number values.",
"As someone else mentioned, it was only doing math, and not terribly complicated math, either. It's also worth mentioning that they had tons of time. It took four days to get to the Moon, so they had plenty of time to crunch the numbers, and the real-time stuff like landing was done manually (although it wasn't supposed to be). A TI-83 also has 32kb of RAM and it can do calculations plenty fast.",
"A lot of memory usage in modern computers goes to things that are nice, but completely unnecessary for computation. For instance, graphics are amazingly memory expensive. A full HD display is 1920*1080 pixels, which in 24 bit color is about 6 MB, and if all you want is to calculate stuff, none of that is needed. Computer scientists used to talk of framebuffers (devices that store an entire screen worth of pixels in memory) as a theoretical concept not so long ago! If you open say, the Windows calculator, the vast majority of memory is going on drawing those pretty buttons. The same functionality can be achieved in just a few bytes of RAM."
],
"score": [
31,
13,
12,
4,
4
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gtr4qd
|
How does photography work exactly?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fse1tbu"
],
"text": [
"Light bounces off everything that isn’t absolutely black. Plants absorb red and blue and reflect green for example. A camera records how intense and what color the light is that bounces off stuff and hits the camera lens. Better cameras have more sensors, more accurate lenses and better software to give a better representation and focus of the light that bounces off everything. Sometimes this means they let light in for a long time to get good pictures of dim stars, other times they have huge lenses to let in lots of light quickly. Camera phones are the meh of real cameras in that they have small lenses and blur easily in low light, but the software is pretty good to make up for their shortfalls."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gtvlid
|
Where does the data goes after deleting it?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fseneo0",
"fseo8jy"
],
"text": [
"Data isn't physical. Take a bunch of pennies and line them up. The order of heads and tails is information. By flipping them all to heads, the information is deleted. It's gone. That said, computers often don't delete stuff unless you specifically order them to - rather they just mark stuff to be paved over. Then, next time you 'arrange your pennies' you just rearrange the existing pennies instead of using new pennies.",
"Data on your computer is stored as 1 and 0 on the harddrive. If you delete something you would simply overwrite the data with 0 or 1, depending which you prefer. Today unfortunately things are a little bit more complicated. Imagine your harddrive as a library. If you put a book (file/data) into the library (harddrive) you put the shelf you put the book in into a index at the front desk. The front desk is also called a journal sometimes. Now if you want to read a book, you go to the front desk and look on which shelf the book is. Then you go get the book. If you remove a book the book actually does not get removed. You simply remove the entry from the index. Now the place where the removed book lies is still occupied by the book, but you know that the book is no longer needed. As soon as you bring in a new book in, you look at the index and search for a free place in the library. The index will tell you that you recently decided that the place of the first book is free. You will take your new book and replace the old book with the new one. Of course you might think, but what do i do with the old book? Nothing. A computer simply overwrites the old book with the new book. So on modern filesystems (the library) data mostly does not really get deleted. It simply gets marked as free space and overwritten as soon as new data needs a place to stay. If you format your harddrive only the index gets overwritten by an empty index so everything is now marked as available. There are special programs or formatting options which are able to overwrite the entire harddisk in case you want to sell your computer. There is also software that is able to scan the supposedly empty space for not yet overwritten data and restore those files. Hopes that makes sense."
],
"score": [
10,
5
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gtzb9k
|
why is it that the bigger your FOV is in a game, the faster it feels like you're moving?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsf8sqg"
],
"text": [
"If you're in a moving car and look straight ahead (in the direction the car is traveling), it doesn't look like the car is moving very fast compared to if you look out a side window (perpendicular to the direction of travel). In the car analogy, increasing your FOV exposes more of the area to the sides of the car to your eyes. So a higher fraction of the things in your line of sight look like they're moving faster. This same idea holds in games."
],
"score": [
27
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gu0ko0
|
Why are games sold in disks? Wouldn't usb drives be more efficient and save space on the console?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsfeh40",
"fsfechs",
"fsfirkd",
"fsfnpb5",
"fsg25jh"
],
"text": [
"USB drives are much more expensive. They don't seem like they're that expensive, maybe $10 or so for one with the same storage as a blu-ray. But when you're mass manufacturing, a single blu-ray disc costs pennies to produce. Shipping on USB drives would either increase the price of games or make less profit for the publishers. Also, as we go into the next generation of consoles, USB drives won't be fast enough. The SSDs that are going to be in next gen consoles wipe the floor with the speeds of a USB drive, so you'd have to install them to the SSD anyway.",
"Discs are cheaper. That's really all it boils down to. Another $1 per copy on thumb drives is a lost $5,000,000 if they sell five million copies.",
"The others are right about the price, but you should consider that Nintendo does sell their games on what is essentially \"usb drives.\" They have constantly run into the issue of cost, though.",
"Switch cartridges are essentially micro SD cards. Nintendo have more or less always flown in the face of standards and done their own thing. Even the micro CDs with the gamecube and Wii were different.",
"CD's/DVD's are cheap which maximises profits, USB's would be great but to expensive, but ultimately what game publishers really want is all digital as that means more money direct to them, less expenses spent on physical media."
],
"score": [
158,
38,
27,
7,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gu2kd7
|
Why do electronic devices like phones and computers seem slower initially after they reboot?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsfri5m",
"fsfs5g8"
],
"text": [
"Modern phones and computer usually delay loading some things in order to boot up faster. The slowness after a reboot is due to all the extra stuff loading in the background.",
"On any given operating system there are tons of background services and threads each doing its own little thing. For example, on my Windows 10 computer there's a little thing called the Windows Search Indexer that continually monitors file changes on my computer and updates a search index or database so that when I search for bread.recipe.pdf, it doesn't have to take 10 minutes to find it, it already knows where it is and that its a PDF and it contains a bunch of keywords in it. Anyways, when the Search Indexer launches, it fires off some helper processes that go off and start double checking every file to make sure its index is still up to date from last time. But these processes are hogging my disk and some of my RAM and CPU, and all I want to do is play Minecraft. Meanwhile there's 200+ other processes that all need some CPU and disk access for whatever they're trying to do. All of these processes clamouring for a little slice of CPU and disk access all add up. Some OSs like Windows 10 can _background_ some of these things or do a \"delayed start\" which means they tell those things to wait a while until the computer is less busy or only permit them to do things when the computer isn't busy at all (like if there hasn't been a key or mouse input in say 5 minutes, which is a good indication you're off doing something else.)"
],
"score": [
11,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gu65u1
|
Why was yesterday's launch considered the first manned mission since 2011 when there have been many manned missions to/from the ISS?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsgek9o",
"fsgex8c",
"fsgf33d"
],
"text": [
"It was the first manned mission from that was launched from American soil on an American rocket since 2011. All the manned missions prior to yesterday to the ISS since the retirement of the space shuttle in 2011 were done via the Russian Soyuz rocket.",
"It was the first manned mission launched from United States soil since the shuttle program was ended in 2011. It was also the first commercial manned mission in history. It’s a big deal because A) the US doesn’t need to rely on Russian rockets to send manned missions and B) Commercial entities in space will open up new frontiers faster than the government could.",
"SpaceX is the first private company to successfully launch a manned mission to the ISS. US astronauts have gone up with other countries' spacecraft, making it the first launch from US soil in many years."
],
"score": [
12,
7,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gu7g5q
|
SpaceX, Crew Dragon, ISS Megathread!
|
Please post all your questions about space, rockets, and the space station that may have been inspired by the recent SpaceX Crew Dragon launch. Remember some common questions have already been asked/answers [Why does the ISS seem stationary as the Dragon approaches it]( URL_1 ) [Why do rockets curve]( URL_0 ) [Why an instantaneous launch window?]( URL_2 ) All space, SpaceX, ISS, etc related questions posted outside of this thread will be removed (1730 Eastern Time)
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fskrhqd",
"fsgnqz8",
"fsk54h2",
"fsily6c",
"fsjmizd",
"fsm3vb4",
"fsmza93"
],
"text": [
"How does the Dragon crew get from their rocket into the ISS? Do they attach their rocket to the ISS or something along those lines?",
"Can someone explain the significance of this event? People have visited the moon before so why is this event important? I mean I guess it's cool but we've seen it happen over and over in the last 50 years.",
"Why are rockets built to go off in stages? what are the benefits?",
"How can they stream such high quality footage from space?",
"Why have we made so little progress since landing on the moon back in the 1969. I understand that this is the first commercially made spacecraft, and that it’s the first manned US flights in 9 years, but with the incredible progressions in technology between 1969 and now, why are we now behind where we were?",
"How does the astronauts there deal with wounds do they use bandages like people on earth or do they use some sort of special equipment",
"Are the tablets that doug hurley was holding in crew dragon to probably do some checklists iPads or are they just other tablets made by NASA and how much consumer electronics are there on the ISS and what are they?"
],
"score": [
10,
10,
9,
7,
5,
4,
3
],
"text_urls": [
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
gu94fi
|
How does hacking work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsh0qdd",
"fsh1kqk",
"fsh1kwa",
"fshpkwc"
],
"text": [
"There are actually two things Anonymous did/does. Hacking and a DDoS-attack. Hacking is like burglary, but digital. You find the weak spot in the system and get into the system from there. Depending on where the weak spot is, the result of the hack can be different. Just like burglary. If you only manage to break into a basement, you can get the stuff in there. If you manage to break into the house and vault, you’ve got the jackpot. A DDos-attack, or distributed denial-of-service attack, is (simplified) attack a website by trying to get to the site from a lot of places at once. Compare it to having thousands of people stand in front of a store. As a result, no one can enter the store anymore because off all the people blocking you. Anonymous combines the two, blocking a site with a DDoS and meanwhile finding vulnerabilities to exploit. They use the distraction of all the people in front the store, to sneak in through the back door.",
"Imagine you have a treehouse in your backyard. You and your friends won't let anyone in without a secret code-word (a password). You write the password down on a piece of paper, and hide it in a drawer so everyone can stay up to date as you change the password. If I want in, maybe I convince one of you that I'm your friend's Dad, and you must let me in without a password or you are all in trouble. Maybe I talk to your friend who is really forgetful, and try a bunch of passwords until he lets me in. Maybe I put a camera in the drawer where you store the password so I can see it when you put it in there. Maybe I climb a neighbors tree that doesn't require a password, and climb across the branches to get in. Hacking is just a general term for getting into computer systems that are trying to keep you out. The specific techniques evolve over time, but in general it's just about tricking the computer system into giving you something you aren't supposed to have, or getting access to something that you aren't supposed to. That can involve using software itself, or sometimes it even involves messing with the humans that control these systems (Social Engineering). Just as an example, an old way to hack was to put actual software code into the password box when logging in. When the computer went to read your password, it would read the code instead, and then execute the code (and the code would be something like, 'let me in without a password'). This was solved by checking what you put in for your password, or extra layers of protection around what get's executed. That cat and mouse game between hackers and software security people continues to this day (and a lot of ex-hackers are actually now in software security).",
"Software (be it website code like WordPress or server-run code/operating systems like Windows) can be incredibly complex and often has bugs. Some of these bugs are innocuous or can't be triggered remotely. However, some can be triggered by sending information to the website, formatted in a certain way. By doing this, depending on the bug, you can fool the server into running any code you want, change data values, save files to the server, etc. Programmers are constantly seeking these bugs out and fixing them. Unfortunately, not everyone updates the code they use. Suppose I was running a website using WebSiteSoftware Version 5. The makers of this found some serious bugs and released version 5.1. However, I didn't update. Hackers find out that I'm running version 5 and, since they know what bugs were in that version, will know how to abuse the bugs to gain access. Then, they take control of the site and change the home page to say whatever the hackers want.",
"A lot of good posts here but I wanted to add a quick point. When it comes to weaknesses and vulnerabilities in any system, the biggest problem is the people using it. You can have the strongest security system money can buy but if \"tech support\" from BigSoftware Co calls and says there's an emergency error on your computer and they need your username+PW to fix it RIGHT NOW and someone gives them that info... well there is no defense from stupid except education. Don't click on links in emails folks, and don't stick random flash drives into your computer, it's literally called a \"lolipop attack\""
],
"score": [
50,
7,
5,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gu9bt1
|
How dating sites get started? How can you encourage your first batch of customers to register if you have nobody else to show them?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsh2pq3",
"fsh4oce",
"fsh5o3q",
"fsh40e1"
],
"text": [
"Populate the site with fake profiles and/or bots, and then phase out the fake profiles / bots as more real people register (or don't). Heck, you could even put your employees to work chatting to those first few pioneers to make the site seem more lively than it actually is.",
"The creator of URL_0 had his employees all make accounts, even the ones in relationships. His own wife left him for someone she met on his site lmaooo",
"I would pay people to use the system. Start with a certain demographic : wealthy college student, christians, adults previously divorced with children, oet lovers. Offer features like anonymity. Offer moderation partnerships. Invite people to sign up who use other platforms.",
"It's a part of general \"platform\" problem. The usual solution is that you initially pay the side that's more in demand. So e-commrce platform will give discounts/incentives to sellers. Dating site will pay bunch of people (not even necesserilly girls) to pretend they are girls in your area that want to fuck."
],
"score": [
40,
24,
3,
3
],
"text_urls": [
[],
[
"match.com"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
guc1o0
|
How do green screens work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fshiqiw"
],
"text": [
"You could do the effect with just about any color screen, blue screens used to be the standard, but people found the bright green worked better. The purpose of the color is to give a specific color to scan for and then eliminate from the scene to allow another scene to be placed in. The bright green is a somewhat unique color, what you want does not get eliminated. Blue is more common, so issues, as would lots of colors that might match skin, hair, eye, and other colors found on people."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gue2uu
|
What are the differences between an HDD (Hard Disk Drive) and an SSD (Solid State Drive)? Why are SSDs supposed to give you faster speed?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fshzir7",
"fshvmuo",
"fshwbvi",
"fsi9ezw"
],
"text": [
"HDD is like trying to get information off the Wheel Of Fortune while a SSD is more like playing BINGO. The wheel has to spin to get to the spot the data is at. The SSD just ask for the info and the spot says it's here.",
"A Hard Disk Drive (HDD) is like a solid plate that is spinning - there are faster and slower ones - and it has mechanical heads for reading and writing information. These are the traditional permanent storage devices on computers. They can be slower because of how it reads and writes data. Solid State Drives (SSD) are basically like a memory card you'd plug into your phone or camera - there are no moving parts and it can read and write information much more quickly.",
"A couples of terms and definitions first. And a simplified answer. Hdd - data is stored on disks that spin and theres an arm that moves to reads/writes from locations. Data that is very spread out has a large impact on performance. Ssd - data is stored in cells and there is a path to each cell. Some cells shared the same wire so only one cell on that bus can be active at any one time. Data that is spread out has a moderate impact on performance. Seek time - time between request of data and the data being returned. Ssds are like < 0.2ms. Hdds are like 5-20+ ms. Throughout or transfer rate - sustained read or write speeds. Hdds are capped around 100MB/s. Ssds go up to a few GB/s. But a low end ssd is typically < 500MB/s. Since responsiveness is more noticable than raw transfer rate you can see the ssd is much more responsive. However if you are constantly transfering large files than throughput helps too. But any cheap ssd will make your computer seem faster/responsive compared to a hdd that's chugging along.",
"Data on a HDD is like having a factory full of stuff, and you tell an employee \"you there, go take a photo of that thing from Row 4, shelf 5, and then send it to me, oh and also get me the thing from Row 2, shelf 3.\" So the employee has to run over to the first thing, grab the information and send it over to the boss, then he runs over to the next thing the boss wanted, and then send that over. The bottleneck in terms of speed is how fast the little employee can run from the starting point to point A, and then point B, which could be at complete opposite ends of the factory. Things get worse with fragmentation where a single file is split into several chunks. Now the task of requesting file A involves multiple stops and just adds even more to travel time because Bob decided it'd be a great idea to scatter the pages of document A everywhere. Also hdds at their peek performance are limited to how fast the plates are spinning. Imagine a record player, if you want a copy of the song, you have to wait for the stylus to read the song information slowly as the record spins, you are limited to how fast that record is designed to spin. With SSDs, all the data is in a single spot, and can be accessed instantly with zero moving parts. The boss requests a file, and it is immediately given. Even if it's in 100 fragments it doesn't matter, because there is no travel time anymore between finding the pieces and how fast it can read that information. It is a significantly more optimal process so the speed goes waaay up."
],
"score": [
33,
19,
10,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
guhiqv
|
what is the “Docker” software and what does it do?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsih44m"
],
"text": [
"Docker is a program to put other programs in timeout, but pretend timeout and share toys with each other. If you have a computer and you want to run a program on it, you install it and run it that way. With larger systems, you might have to install the same program, but have different versions of it. These different versions might conflict with each other and the programs requiring the different versions might break otherwise so need the specific versions. To resolve this, there are two options. You either have a computer for each version which is VERY expensive, or you do it virtually by pretending to have multiple computers all in software. This virtualization is the basis for \"the cloud\" that all of the tech companies talk about. Traditionally, you would have a virtual machine witch was a complete virtualization of an entire computer and requires a lot of memory and processor power. What docker does is examine what is shared between docker containers and uses it only once. If you have 15 docker containers running and they all use the same program, then it'll use only one instance of that program instead of having 15 different virtual machines running, but the containers can't talk to each other unless you let them so they don't know about each other for security reasons. This reduces resources required to run the programs. In addition to this, docker also looks at the computer running the containers to see if it can share resources there too. It took years for them to optimize everything, but it's very efficient nowadays to run many docker containers instead of many separate virtual machines."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
guhw37
|
How is some PC memory volatile (e.g. RAM) and some memory non-volatile (e.g. an SSD)
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsihcjh"
],
"text": [
"RAM just happens to be volatile, but it's not because it needs to be. Computers need memory to store the data they are working with. This memory doesn't need to keep the data once the computer is shutdown but it needs to have random access and be really *really* fast. The best technology we have to do this at scale is [DRAM]( URL_0 ), which happens to be volatile."
],
"score": [
7
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Dynamic_random-access_memory"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
guiur4
|
How can they stream live footage in such high quality from space?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsipiit",
"fsio051",
"fsimudf"
],
"text": [
"Do you have satellite tv? HD broadcasts are transmitted to your tv from much further away than the ISS. Satellites for TV are 36,000km away vs 400km for the ISS.",
"The ISS is actually not that far, it orbits at about 400km from the surface of the Earth. We have no problem broadcasting videos from one side of the Earth to another, so just 400km away only requires a good camera quality and a good bandwidth to upload the data. The ISS has both, so they are able to stream high quality video from space.",
"They have a good camera and a good antenna to communicate with. Everything else is the same as almost anywhere else in the world. Many live streams of events get sent to the stations via satellite. News reporters have had news vans for decades that have satellite dishes attached to them so they can report from the news location live. The space station communicates with an array of ground stations across the world as it flies around and by communicating with those stations it's able to maintain adequate bandwidth to live stream the high quality footage. Jumping from station to station as it goes around and maintaining the stream is the real trick as the stream's source needs to be continuously updated and fed into the main feed. This requires a good network on the ground."
],
"score": [
20,
13,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gujwyk
|
Why do OLED screen burn ?
|
I've seen plenty of sources telling it's because some pixels stayed static for so long, ok, but that's not an issue with LCD. Why is it different for OLED and how come you can damage a screen just like that ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsiud4o",
"fsiu879",
"fsitm4x"
],
"text": [
"This is somewhat of a two-part answer. There are actually two forms of ‘screen burn’ that can happen with OLED displays. One is usually temporary and results from the OLED displaying the same colour for a long time (a few hours perhaps) which causes a residual colour to continue being displayed. Once that fades the screen returns to normal. One is permanent but takes much longer and is influenced by environmental factors like long term harsh sunlight exposure. It is called luminence degradation - as the OLED components age with use they become dimmer, and if a particular group of pixels is used excessively they can degrade at a faster rate than the other pixels, making them less bright or causing them to display certain colours less vividly, leaving an impression of an image. Both take a very long time to become a problem. Higher brightnesses and cheaper displays typically result in faster burn in (of both types). For common use I’d say it is relatively safe to say that OLED screens do not burn in - at least not permanently.",
"An LCD is a display made with liquid crystals. The liquid crystals are pretty stable and reliable; it's the other components that generally fail first. OLEDs are organic light-emitting diodes. This means an OLED generates light when electricity is passed through it. The organic part means the LED is made out of organic compounds. It's the organic compounds that degrade over time. When you leave an image on the screen for too long, the LEDs showing that specific image will wear out faster in the bright areas which causes the image to be burned in. Ideally, all of the LEDs of the OLED will be used equally so the brightness with decrease evenly over time, but this doesn't happen. Imagine leaving food out uncovered. The food will eventually spoil, but if you shine a bright hot light on it it'll be faster. If you have a lot of food, then the hot lights you keep shining will make the food under the light spoil faster than the other food in the shade. Imagine the OLEDs as food and the electricity/light as a lamp speeding up the spoilage.",
"An LCD works by filtering the light from an always-on white backlight. In older/cheaper screens, that backlight would be white fluorescent tubes, in newer ones it's a bank of white LEDs. On top of this is a coloured filter layer, and then the LCD layer itself, which restricts light. If you're displaying a black screen it filters all the light, if you're displaying a perfectly red screen it filters out all the blue and green, for example, leaving just the red. Point is, the white backlight is the light source. In an OLED screen, every pixel consists of a red, blue, and green LED, and it generates its own light. LEDs naturally get dimmer as they age, anyone who has used a set of LED christmas lights over multiple years will have noticed this - older sets get dimmer. So in areas of the screen that display a brighter image, for a long time, the LEDs responsible for those areas will get dimmer overall compared to the rest of the LEDs. So if you then try and display a white screen, the LEDs that are more worn out will show as a dimmer area of the screen (or more likely, show a colour cast, because certain colours of LEDs wear faster than others)"
],
"score": [
9,
4,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
guk8j5
|
How did Stalin's photo retouchers able to do what they did ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsitz9b",
"fsj4kng"
],
"text": [
"In the early 20th century, most photos were black and white and had to be chemically treated in order to be developed. Once a print of the original image was made, an artist could use white paint and black ink to cover up and alter parts of a photograph to make people or objects \"dissappear\". Then, a photo would be taken of the altered print and developed. Later on in the 20th century, devices like a xerox machine would make it easier to reproduce an artist's touched up photo.",
"\"Airbrushing\" as a term to manipulate/doctor photos was quite literal in the pre-digital era, you used an actual airbrush to paint on the photo. This was better than prior methods which involved actual brushes or a needle/scalpel as you didn't leave behind any obvious marks like scratches or brush strokes and the soft edges of the airbrush allowed much more natural gradients. Typically this was just used to clean up skin blemishes and minor things of that nature, but the Soviets got really good at it to the extent of being able to remove people entirely from photos. I'd show you a video of airbrushing being done to manipulate a physical photo or a photo negative but the term is so synonymous with manipulating photos in general that I'm only finding photoshop tutorials."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gun6tg
|
Why is it a a bad idea to use base-64 encoding to create an impossible to guess but easily reversed password when using a password manager?
|
ELI5 why it's a bad idea to use base-64 encoding to generate a very long password that is easily reverse engineered in case of loss but almost impossible to guess? For example, l use a password manager and am worried that they may one day just go out of business and shut down, so I generate all of my passwords for a given site using an input template of < some consistent phrase as a seed > +username+website/app in question. That results in a 20+ character password that I can easily recreate if lost, but will be impossible to guess or brute force.\\ For example, lets say my input is ilovepasswords+binkleyz+reddit , my output would always be " aWxvdmVwYXNzd29yZHMrYmlua2xleXorcmVkZGl0 ", so I can always get that long-ass password back by knowing the input format but it would be impossible to guess. A good encoder/decoder is [here]( URL_0 )
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsjcqqd",
"fsjfmhu",
"fsjd9aj"
],
"text": [
"Base-64 encoding is fairly recognizable and completely reversible. The second any of your passwords is breached, all of your passwords would be breached.",
"The fear a password manager might one day not be available any more is not necessary. You can download e.g. KeePass and other and just store it offline. Then it is best to not update the installation for the password database you are using. That way you can always reinstall should you need it later on and it should stay compatible with your password database.",
"As drafterman said, anyone who has been programming for any amount of time will recognize base64 encoding in a heartbeat and “crack” it in about a minute. Maybe 2 if they take a break to heat up a hot pocket. If you are doing this then you may as well just save it in clear text."
],
"score": [
16,
9,
4
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
guntcx
|
Why sometimes the phone’s battery runs out slowly and sometimes quickly (several percent at once in a short time). Though, your doing the same thing on the phone.
|
Like, why can't it calculate how many charge units are left in it
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsjgzgr",
"fsjh6ih"
],
"text": [
"Because battery life is determined by many factors. Temperature. Number of background apps. And more. The % is also an estimate based on internal resistance in the battery so it's a guideline only.",
"One possible explanation is that all household batteries are affected by temperature. In really hot and really cold weather, batteries don't operate as efficiently and therefore may not be able to hold a charge as long, even if you're doing the exact same things on your phone."
],
"score": [
5,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
gupwqi
|
Why/how does 5G offer much lower latency than 4G?
|
Why is it that 5G will give us a much lower latency than 4G? Where’s the bottleneck in 4G?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsjvjmp"
],
"text": [
"the latency reduction is mainly from advances in mobile technology, ie the radio towers that transmit/receive the data as well as the SOC's on the phones. 5G uses much higher frequency (and requires more power) compared to 4G which allows a \"tighter beam\" that directs the data better and is less susceptible to noise/interference. as with most things in technology. we probably could have implemented a global 5G network 10-20 years ago, as the baseline technology is really nothing new. but it wouldn't have been cost effective. frankly speaking a lot of current technology isn't \"groundbreaking\" they are just iterative processes that was possible many years ago, but it wouldn't make sense financially until other supporting technologies caught up to make it cheaper. so to answer your specific question. if we implemented the 5G network 10-20 years ago instead of now. here's what it might look like. from the radio tower side, we would need a much more massive radio transmitter/receiver and might look something like [this]( URL_1 ) and from the phone side, we would need a more powerful SOC and radio antenna inside the phone as well as a much larger battery. so it might look something like [this]( URL_0 )."
],
"score": [
6
],
"text_urls": [
[
"http://hight3ch.com/wp-content/uploads/2008/02/worlds_largest_phone.jpg",
"https://www.seti.org/sites/default/files/styles/original/public/2020-02/vla_panorama_med-1.jpg?itok=jt_YYFCd"
]
]
}
|
[
"url"
] |
[
"url"
] |
guqnmf
|
how does internet speed work?
|
Scenario: first I check my speed on [ URL_1 ]( URL_0 ), it says I have 10mbps.... good. I start downloading something and it's downloading at 0,5mbps. While downloading I check my speed on [ URL_1 ]( URL_0 ) again and now it is 300-500kbps. Why? shouldn't it be 10mbps-0,5mbps=9,5mbps. right? why does 0,5mbps take all my 10mbps away. I don't understand, please explain
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsk0b35"
],
"text": [
"You are mixing units. Internet speeds are typically measured in mega**bits** per second while transfer speeds in downloads or on your disk are usually measured in mega**bytes** per second. There are eight bits per byte. Megabits per second is \"Mbps\", while megabytes per second is \"MBps\". You need to look carefully to avoid confusing them. In your example you have 10 Mbps and are downloading at 0.5MBps. This means you are using about 8.5 of your 10 Mbps for the download, so when you test again you have around 300 Kbps left, and a bit more when your download speed reduces for a moment (since you are now competing in demand with the test)."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gusuy4
|
What are the hang ups on real life grappling hooks? Why are they not nearly as powerful, fast, and portable as they are in fiction?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fske6wk"
],
"text": [
"Basically every aspect of them is more difficult than fiction would present. The basic concept is that you need to launch a hook and associated rope/cable a great distance, and that means moving a significant weight with a single impulse. Unless it is unreasonably light the recoil would be impossible to manage with a single arm as in fiction. Also the cable and hook would need to be very small in order to fit into the form factor fiction imagines, which in turn requires they be absurdly strong for their size. Next is the question of what you can anchor the hook securely to? Even if you could set the hook into something it isn't likely to be designed to securely hold the weight of a full grown human. You are more likely to pull the gutters and shingles off a roof, or just have it bounce off the side of a building without attaching at all. Batman jumping off a roof and ripping the mortar out of the neighboring building's wall is more realistic. Consider what you are supposed to do even if you could get a magically strong and light hook and line set securely into a building. How do you climb up? In most cases people cannot safely be hauled upward at speed supported by a single hand, and even if they were sufficiently strong what precisely would be doing that hauling? Now you need an unrealistically strong and fast winch, along with its associated power source, embedded within the launcher that couldn't even hold the line and hook!"
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
guzlnz
|
Why do YouTube videos reload the player after being paused for a long time
|
I often find myself idling on YouTube videos a lot and sometimes I'll forget about the page entirely, but eventually I do come back and in the cases where I'm not playing the video for a few hours, when I come back to the page and begin playing the video the player will reload completely as if I just loaded up the page, I'm interested to know why this happens.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fslkawo"
],
"text": [
"It’s probably due to ram usage. If you are using the ram for other tasks it sees the loaded video that you aren’t watching as a waste of space. Google chrome will do this with any tab you don’t open for a while."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gv1wwo
|
if Im downloading a game at 100mbps why does it take way longer to download than math says it should?
|
For example on xbox its showing 100mbps. Theres 10 gb left to download and its telling me 15 mins. Im no mathematician but seems like i should be downloading 1gb/10 secs. So this whole 10 gbs should take me 1 minute and 40 seconds. Why are the download speeds its showing never right? I can watch the numbers going up and its also clearly not 100 mbps, looks more like 15mbps. Ps. This is on the xbox one over wired connection if that matters.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fslyxkm"
],
"text": [
"You are probably confusing bits and bytes. A byte is 8 bits. Internet speeds are often give in bits, but file sizes are in bytes. 100 mega*bits*/s are just 12.5 mega*bytes*/s, so the download actually takes 8 times longer than you think."
],
"score": [
16
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gv21zn
|
Low RAM Timings vs High Frequency for low input lag experience
|
Explain me, what do the timings
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fslzrtb"
],
"text": [
"Basically timings are the different time it takes to access data and/or retrieve it from the RAM module itself. Frequency is how many operations the RAM module can do in 1 second (literally what hertz means, repetition per second). I think this video will do a better job than I can do: URL_0"
],
"score": [
3
],
"text_urls": [
[
"https://www.youtube.com/watch?v=Yed-a9vqTYc"
]
]
}
|
[
"url"
] |
[
"url"
] |
gv6u5e
|
What does 'a memory leak' actually mean?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsmr8v6",
"fsn1idm",
"fsmrszz"
],
"text": [
"Look at your computer's memory as a storage room. You want to store something in memory. You must first allocate it, otherwise you can't find it again. You need a box. You allocate a box, put some stuff in it, and put it in the storage room. The space taken up by the box is allocated and now considered used in the storage room. You keep doing this over and over and now you have several boxes in the room. Now you no longer need what is in one of those boxes, so you discard the items, but you leave the box in the storage room. The items are gone, but the box still takes up space in the room. Alternatively, you want to store items in a box but that box is too small. You take the items from one box, put it in a large box, add the other items, and put the new larger box in the storage room, but you forget to take out the smaller box. You now have a bunch of empty boxes taking up space in the storage room, and you've forgotten which ones they are, and this continues until you've run out of room in storage.",
"Memory is a like a library, you check out a resource, use it for a while, and return it when you are done. But if you are forgetful, you might sometimes fail to bring your book back. Even if it only happens occasionally, after a while, the library runs starts running out of books and no longer has anything for new borrowers.",
"What several people have described are buffer overflows, a type of memory error but not a memory leak. When running a program various tasks within the program will require the use of memory. Modern programs are not running in a vacuum but on an operating system with many others, and they are expected to play nicely together. So when a program needs memory it requests it to be allocated for its use, stores some values there while needed, and then when done releases it for other use. That is the theory. If a program has an error though it could just fail to release the memory it used and close itself down, leaving that memory reserved for no reason. It usually isn’t a huge amount if memory but all those reservations add up, eventually being noticed as a general reduction of the amount of free memory available for reservation. The user looks around and wonders “Hey, is memory leaking out somewhere?”"
],
"score": [
9,
7,
5
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gv85uv
|
How do POS systems know/update your balance without internet? How can you pay using a POS in a plane 36,000 feet above the ground?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsmyuql",
"fsmywzm",
"fsmz2j4"
],
"text": [
"answer : The airplane has an internet connection, even if it isn't offered to the passengers.",
"It stores the transaction data, and then sends the information when the next connection happens. This is how credit worked from it's inception. They used to just write down your information and then send it to the credit card company, and they would manually update your account balance That being said, they probably do have a connection while on the plane. Modern planes have had a data connection for well over a decade. They just don't all give customers access to the network.",
"On an airplane, many transactions will be accepted without contacting any banks, and stored for processing later. The merchant is willing to accept the risk of a declined transaction as a cost of doing business (especially given that many on-board items have a huge profit margin)."
],
"score": [
17,
8,
6
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gv89gd
|
Why do old televisions emit high-pitched noises while in use?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsmzqp6"
],
"text": [
"The way those TVs work is that an electron beam (or cathode ray, hence the CRT name) is fired at the screen, and it is moved left to right and top to bottom, these movements are caused by magnetic coils that bend the ray in rode to hit the correct point on the screen In America TV runs at 30 frames per second and there are 525 lines in a single frame, this means that the electron beam has to move left to right 15750 times a second. The coils also move very slightly because they are two magnets one against the other, and, 15750 hz is an audible frequency, so those coils act as small speakers and you hear that sound In Europe it’s a slightly different pitch of 15625 hz"
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gv8s2j
|
why is it possible to retrieve data from formatted Memory Card or Hard drive?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsn3bgk"
],
"text": [
"Because in general, \"deleting\" something doesn't necessarily remove the information. When you hit \"delete\", what you're really doing is erasing not the data itself, but the little bit of data that tells the computer *where* the file is stored on the drive. The way this works is that on each drive, there's a file table or other storage structure that says something like \"file A lives at address 1, file B lives at address 4, file C lives at address 56,\" etc. It's more complicated than that, but that's a good general idea. When you hit \"delete\", all you're removing is that entry. The actual 1s and 0s that make up the file are still wherever they were--and if you go over the drive bit by bit, you can see the data still there."
],
"score": [
7
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gv8yhf
|
why this random number generator has these lines ?
|
[This]( URL_0 ) post from dataisbeautiful shows how the random numbers generated are not truly random. Why is that so?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsn5490",
"fsn4lfv"
],
"text": [
"The random number generator in question is [RANDU]( URL_0 ) RANDU has a very simple function which does given you a uniform distribution but also results in repeating planes if you plot it in a 3D cube V_j+1 = 65539 * V_j mod 2^31 That weird cube comes from asking it for X, Y, and Z coordinates by asking for 3 random number generators in a row, if you chug through the math you find that you end up with Z=6Y-9X, that's not going to give you random points that's going to give you X-Y planes that are 3 steps apart in the Z axis because if X and Y are integers (not decimals) then you cannot possibly get a Z value of 1 or 2, it can only be 3, 6, 9, 12, 15, etc The plot in data is beautiful has the values divided by 2^31 to normalize them but it did the initial calculations on whole numbers",
"You can't actually randomly generate numbers (theoretically ever, really, but we'll speak pragmatically). If you mathematically create a number based on some other number, if you repeat the calculation you'd always get that number again, no? So, you can make numbers more intractable to guess, but you can't make them random"
],
"score": [
9,
4
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/RANDU"
],
[]
]
}
|
[
"url"
] |
[
"url"
] |
gv95to
|
How is it more efficient to keep the AC on all day rather than turning it off in the morning and back on in the evening?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsn9hx3",
"fsnajo2",
"fsn8gnd"
],
"text": [
"In point of fact, it is _not_ more efficient to keep it on. Every second that thing is running it's actually a) making heat (outside, thermodynamics-style) and b) making your house gain more BTUs/s from the outside (by increasing the temperature differential).",
"It's not more efficient. There is the same myth with heating. However if you use a small air conditioning unit that needs to be ran 24/7 to keep the house cool enough, then that can be more efficient than an oversized air conditioning unit that cycles on/off.",
"The rate of heat move between objects depends on the temperature difference. So if the inside of the house is cooler the amount of energy that leaks in per unit of time is higher. The total energy that leaks ins during the day is what the AC has to remove. If the rate is lower less for the same timeless energy have leaked in and needs to be removed. So the AC has to work less to remove it so the cost is lower. You can take an extreme example if your house reached outside temperature after 1 hour and you are away 8 houses. For 7 hours no heat will leak in because the outside and inside temperature is identical. So cooling it down when you come home is the same as it would need in less then one hour if it was on."
],
"score": [
107,
15,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvaqaf
|
Why do you need to change your password when you forget it? I'd much prefer to just be reminded of it by email, for curiosity and for convenience.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsnfvpc",
"fsngp5o",
"fsngpwb",
"fsngv96",
"fsngwhx"
],
"text": [
"because it's bad practice for someone to store the password in a way that they can retrieve it. this is in case they get hacked. instead, they store a \"hash\" of your password and compare that each time you log in.",
"Most of the time, it is because the website/service doesn't actually know what your password is, so they can't tell you what it is. It gets a bit beyond an ELI5, but good infosec prevents the storage of plain-text passwords. Passwords are hashed - encoded so that the original password is stored as an encoded version of itself. When you put your password into the website, that password is hashed and compared to the stored value - if they match, you are grated access. (It is actually much more complex than this, but this is ELI5) Now, you may ask, 'why not just unhash the password and tell you what it is?\" Well, that is because of some really complicated mathematics (which I don't fully understand) the equations used to hash the password don't work in reverse - you can plug a variable into the equation and get and answer, but you can't plug the answer into the same equation and get the original variables. So, the website doesn't do what you are asking because it can't. The only solution is to change your password.",
"Convenience is almost the exact opposite of security. If you care about the securotybof your data, you really don't want password recover to be convenient- if its convenient for you it's easier for you to get hacked.",
"1. For security reasons, they don't actually store your password. They store a thing called a hash. When you input your password into a website, the website actually generates the hash and compares it to what the website has on file, not your actual password. It is practically impossible to recover the original password from the hash. 2. They would have to send you your password over plain text in an e-mail which is an insecure delivery method for anything but a one-time password (and even that is not a good practice). 3. Also, if you forgot it, then it really wasn't a good password as passwords should be easily remembered so you aren't tempted to write them down. As an alternative, you can have hard-to-remember passwords in conjunction with something like a password manager, eliminating the need to remember lots of different passwords.",
"It's that way so the administrator or tech support guy who manages the website or software does NOT have access to everyone's passwords. If it's saved anywhere (for you to be \"reminded\" of it), administrator-level access will let the tech guys see it. This way, they can't."
],
"score": [
41,
21,
8,
8,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvb33v
|
Why does touching a cord to my skin that’s plugged into the wall stop my Bluetooth headphones from buzzing?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsnm8np"
],
"text": [
"I'm by no means an expert but I know that subs can suffer from a ground loop which cases buzzing. My guess would be a similar issue where by touching the wire you are grounding your earphones and giving the electricity that's causing the buzz a route to ground. What happens if you wear them barefoot or touching a metal pipe? Hopefully someone with better knowledge will correct me and give you a better answer."
],
"score": [
25
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvb377
|
How is it decided how much memory a picture takes. Like what makes a difference and why do some pictures take more memory than others.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsnichi",
"fsnk7a3",
"fsnmocu"
],
"text": [
"This depends on the type of compression used and with many compression algorithms depends on the complexity of the photo. If the photo is comprised of simple shapes and solid colors then it compresses better than a complex scene with many colors.",
"Zoom into a picture. You will see its made up of lots of individual dots known as pixels (picture cells). More detailed images will require a lot more cells. The more cells the bigger the file size. How the file is formatted can affect this though. There various algorithms used to reduce the size. Say there was a line of 3 red pixels then a line of 4 blue pixels. You could say in the background its RRRBBBB In this imaginary file structure here the file of made of 7 individual characters. A compressed version might be able to understand R3B4. Which would be 4 characters long. So if the amount of characters affects allocated memory. Our compressed version takes less space. More detailed images requiring more lines to be written. Obviously simplified the above but colours themseleves are made up of a number of 0-255 red, 0-255 green, 0-255 blue. So we might need to say for earlier example. 255,0,0 (which is red) followed by the quantity of that colour. 255,000,000,3 000,000,255,4. Same as earlier R3B4. Just obviously im giving specific colour values. I cant use letters to repressent all colours. The reader could generate a colour by reading the amount of red green and blue then the qauntity of it. Depends entirely on the formatting of the file. 1 byte of data is enough to store a number 0 to 255. So a colour could be made or 3 bytes. If you use more colours then you need to allocate 3 more bytes of memory. Ofcourse im using a rather simplistic way of formatting Hope this makes some sense. You could take a text file yourself and see what effect on filesize it makes when you include more info",
"For a digital camera, the answer boils down to: color depth, resolution and compression used. Another post in here described color depth a little but it's just how much data is used to represent color. 24 bits is typical for cameras. A typical iPhone has a 12 megapixel camera, which is a resolution of 4032 x 3024. 4032 pixels across, 3024 pixels up-down. Each pixel requires 24 bits of data because of the color depth. From there it's literally just multiplication. 4032 \\* 3024 \\* 24 = 292,626,432 bits / 8 for bytes and some extra division to remove all the numbers and make it MB = 12.1 MB, were it not compressed. Almost every digital camera is going to compress this image, usually with lossy compression. iPhones use JPG, which has a typical compression of 10:1, meaning 12.1 MB will compress down to 1.2 MB. Your file sizes will vary heavily. \\[Edit\\] Bits, not bytes."
],
"score": [
18,
11,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvbn9k
|
How does data know which way to take through the internet?
|
Let's say, I'm in the US and browsing a Website hosted on a New Zealand Server. Since there are so many undersea cables, how does the data know which way to take to my computer? And what happens if the "usual way" is out of order for some reason?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsnmmh4"
],
"text": [
"Each packet of data on the Internet has a \"header\" attached to it, like the envelope of a letter. The header contains the IP address and port that it is from and the IP address and port to which it is destined. Every box making up the Internet has tables for each of its output wires defining which IP addresses are \"that way\". (Actually routing is much, much more complex than this; but ELI5.) The path from box to box to box to undersea cable to box to box to ... can all be mapped out through these tables located in every box. The problem isn't over hard, because each box only has the table it needs. For example the router your ISP gave you only has two outputs. The \"local network\" is one way and \"the rest of the Internet\" is the other way. It can send the packets from your computer to your printer one way and the packets from your computer to reddit the other way. You have the least complex sort of router, but it was \"free\". Carrier central routers are multi-million dollar specialized computers."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gvjn11
|
why do computer processors need clocks?
|
I’ve looked this up and every explanation just dives into a deep convoluted mathematical lesson, or gives surface level info like “a processor needs a clock because the faster the clock ticks the more operations a processor can do!” I’ve always struggled to understand this and would really like to know.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsp2lcb",
"fsp4yui",
"fsp8p6l"
],
"text": [
"The processor is a [state machine]( URL_0 ). It means that the millions of transistors in that chip aren't just flipping 1 to 0 and back willy nilly, they actually have to be synchronized. The processor goes from \"my transistors are doing this\" to \"my transistors are doing that\", they're all synchronized. Otherwise that processor wouldn't accomplish anything. So it's not a clock as much as it is a metronome. Like a sergeant yelling \"left right left right\", and the entire processor is wired to follow the cadence.",
"On the hardware level, everything the computer does is both time-compact and repetitive. Time-Compact meaning a particular transistor is busy a lot, without much idle time. Repetitive because the list of things a processor can do is short compared to the number of things it does per second, meaning there’s lots of repetition. Most of the time, when a transistor in a large group (maybe something that does multiplication, for example) does something, it takes in a signal, processes it, and makes it ready for the next thing in the chain. However, the previous transistor also just finished a new thing to do (time-compact), and the next transistor is still working on the most recent thing (again, time-compact). All the elements have to hand their result forwards at kinda the same time, otherwise old signal and new signal would overlap and mix in a way that can’t be un-mixed. This would be easy in a system that wasn't repetitive or time-compact, because then the signal could flow forward as quickly as it wanted because nothing would be in the way for it to overwrite. A clock, with rising and falling edges, controls when data moves into and out of sub-systems in the processor and/or memory. For example, data moves towards math elements on the clock rising, and gets recorded from math elements when the clock falls.",
"You do not need a clock for a CPU. It is just the most common way to build logic circuit. A logic circuit that uses a clock is called a synchronous logic circuit and one that does not is called an asynchronous logic circuit. There exist CPUs of both types. Both types have advantages and disadvantages. A asynchronous circuit can be faster and require less power. But they can require double the number of transistors. They are today harder to design in large part because they are a lot less common so few are trained to design dem. The software used to design chips is made for synchronous design and not having that support makes development harder. Some argue that the are inherently harder to test and debug other disagree and say that it is just because we have not developed So perhaps for good reason or perhaps not the electronics industry is good at designing synchronous circuit and that is what they continued to do. The result is they continue to do synchronous circuits. Research is done in this field and you might see more of it. You can find a list of [Asynchronous\\_CPU in the wiki article]( URL_0 )"
],
"score": [
48,
4,
3
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Finite-state_machine"
],
[],
[
"https://en.wikipedia.org/wiki/Asynchronous_circuit#Asynchronous_CPU"
]
]
}
|
[
"url"
] |
[
"url"
] |
gvkfho
|
How do double barrel shotgun shoot bullets one at a time
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsp7thc",
"fsp87eb",
"fsp84ky"
],
"text": [
"It depends on the gun. Either it has 2 triggers, one per barrel, or the single trigger causes a hammer to fall on the first barrel, then when you keep pulling/squeezing it a second hammer falls on the second barrel.",
"There are a couple of ways of doing it. The way a firearm's trigger mechanism works is, when you pull the trigger, it's a lever connected to a mechanism that rotates a piece of metal called a \"sear.\" The sear has a notch in it that acts as a retainer, holding back the hammer or striker until you fire the weapon. When you pull the trigger, the sear rotates until the notch reaches a certain position, which releases the hammer/striker, allowing it to smack the firing pin, which fires the cartridge (gun goes \"boom\"). Some double barrel shotguns have a separate trigger for each barrel. This requires more parts, but is mechanically simpler, and means that a breakdown only affects one barrel. Other designs have a sear with two notches--one for each barrel's hammer/striker. You pull the trigger so far and one barrel fires; pull it the rest of the way and the other barrel fires.",
"A) 2 triggers and two hammers or a trigger and a selectable hammer. The hammer hits the primer, which ignites the charge which in turn propels the shot B) they don’t shoot bullets. They shoot “shot” from shotgun shells. A bunch of pellets- Generally round, generally lead. There are exceptions"
],
"score": [
5,
5,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvm38v
|
Where is the internet?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fspjcvl",
"fspjvp8",
"fspjhge"
],
"text": [
"everything on the internet is saved on someone's PC. well, not actually someone's personal computer, but a most of the stuff you interactive with is saved on a dedicated server that only stores information and serves it to people. all these servers plus you and me browsing makes up the internet. and to connect all these computers together, there are wires that go all over the place, like the massive underwater fiber optic cables connecting the continents.",
"\"Internet\" is short for \"interconnected network\" and that's really the most important thing to know about where the internet is. It's not just in one place, it's everywhere, connected together. The internet consists of millions of computers that all talk to each other, and that system of \"talking\" is what the internet is. All the data is stored on individual computers. Computers that exist just to store data for the internet are called servers. Big companies buy very big server computers, and lots of them. So many that they fill warehouse-like buildings with giant server computers. Companies like Google or Facebook that deal with huge amounts of data need huge server farm buildings to hold it all. But the internet also includes individuals at home, like you. Your own computer can be a server, too, albeit a small one. Every computer that makes data available to all the other computers online is part of the internet.",
"Data centers All over the globe, companies have buildings, some rather large, full of computers and disk drives that store and serve the content you see on the internet. Many companies own several of these for redundancy, load balancing, and proximity (the closer it is to you, the faster it can be served). All of these places are tied together in a mesh network we call the Internet"
],
"score": [
14,
5,
3
],
"text_urls": [
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvqdpl
|
How does torrent sites make money?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsqe0jh",
"fsqhev1"
],
"text": [
"there are several options: - they dont (some might just set up a torrent server because they want to and then pay the bills themselves) - ads on the site - donations (paypal/bitcoin-donations from people using the site) - in theory: by adding malware to the torrents (and thus turning your computer into a part of a botnet for example or the like)....but I don't think this is actually done (or rather the one providing the platform is rarely the one providing the actual torrents, so...)",
"Usually ads. The Pirate Bay trial in Sweden gave an insight into the venture. They made millions on ads, paid zero in license fees to copyright holders. That made them a lot of money. Another interesting aspect in the trial, was that the defense claimed the owners were mere a platform and didn’t know what was shared. Yet they did remove mislabeled titles or fake content and child pornography, so they did indeed have a very active role in what was distributed on their site. That was one of the reasons their “we are just a natural search engine” defense didn’t work."
],
"score": [
6,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvsitj
|
How does an email know where to go?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsqlb8w"
],
"text": [
"You press send and your email software looks up the the ip address registered for @domain and connects to the server and uploads the message. The server then reads the \"to/cc/bcc\" addresses and looks up the domain information for each address. The information will tell the server what name servers are assigned to them. Then a request is made to those name servers for what's called the MX DNS record. That MX (mail exchange) record says which ip address handles email for that domain. The server then sends the message to that server. If successful, the message is removed from the queue to send. If unsuccessful, it's requeued and tried again later. If it fails too many times, it will send an email back saying there was an error. When the message is received by the receiving server, it forwards it to whatever program handles mailboxes. When the recipient checks their mail, they'll see a new message from their mailbox. There are still differences in specifics regarding protocols and how mailboxes are handled and stored, but that's the general method of what happens."
],
"score": [
9
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvt5of
|
where and how is data actually stored on a Micro SD or other form of small memory device?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsrlma3"
],
"text": [
"It's Flash memory. And flash memory is made of MOSFETs with a floating gate. Explaining what exactly that is isn't very ELI5 friendly, because it's a deeply technical matter. But it goes something like this: A MOSFET is a type of transistor. A transistor is an electrically controllable switch with 3 terminals: the \"drain\", which is where it takes power from, the \"source\", where power is emitted if it's in the \"on\" setting, and the \"gate\", which determines whether it's on or off. In the water analogy, it's a [faucet]( URL_0 ). In a normal MOSFET for it to be on, the gate must be constantly powered. Think of it like one of those [public bathroom faucets]( URL_1 ) that turns off by itself. If you stop pressing it, you stop getting water. In a floating gate MOSFET you can imagine that there's a can on top of the button. If the can is full, then it's always pressing on the button, and if it's off, then it never is. For technical reasons, your best way of filling or emptying this can is to stab it with a syringe, and so every time you do that it gets a new hole in it, and gradually wears out and becomes useless. Which is why Flash has an endurance limit of how many times it can be written before it fails. In SLC flash (which is rarely seen anymore) there's one bit per MOSFET: either water flows or doesn't. In MLC flash there are several levels of water possible in the can, which produces different possible flow intensities. This stores more data, but it's trickier to work with. But this is a very, very surface level explanation."
],
"score": [
6
],
"text_urls": [
[
"https://i2.wp.com/randomnerdtutorials.com/wp-content/uploads/2016/03/water_analogy-1.png?resize=508%2C273&ssl=1",
"https://images-na.ssl-images-amazon.com/images/I/51VYcdSbneL._AC_SL1000_.jpg"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvve77
|
how do microphones not include system sounds?
|
So, if I’m in a call with someone, with the speaker on, why does the mic not receive the sound the phone is emitting?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsr4jcj"
],
"text": [
"The simplest systems just turn off the speaker when the microphone is in use and turn off the microphone when the speaker is on. More modern systems use signal processing algorithms to filter the sound from the speaker out of the microphone signal."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gvyppl
|
Regarding Huawei and their 5G hardware in Europe (But globally as well)
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsrr8vw"
],
"text": [
"I'm a software engineer, not a cryptography expert. But one potential attack would be sabotaging a random number generator so the random numbers could be predicted. This might allow users who possess knowledge about the sabotage to crack cryptographic keys, etc. The other problem is that the Chinese government maintains a high level of control of the corporations it allows to exist. Understandably, no one wants to disappear, or have a family member disappear, into the murky waters of the Chinese justice system. If the Chinese government wants a back-door, they'l have it."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvzexl
|
What happens when you save a game?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsruvak",
"fss19gi",
"fss1069",
"fssm4vj",
"fsst4qo"
],
"text": [
"The game creates or updates a file that it is using to store your current game state. This can be a very basic set of information (like what level you were on) or a massive set of information like the positions of hundreds of items you’ve littered all over Skyrim, the contents of numerous storage containers, the quests you’ve completed, the state of every NPC... Exactly what is saved and in what format varies considerably between games.",
"Take a very simple game like pong. The way the game works is to have variables that store the position of the two paddles, position of the ball, and the direction and speed the ball is going. Every time the screen is redrawn, it checks to see if there’s user input to move the paddles, and if so updates their location, and updates the position coordinates of the ball depending on its speed and direction. It then draws everything on the screen. Therefore to save the game, all it needs to do is store the contents of these variables somewhere. By restoring this information, it can draw everything exactly as it was when the game was saved. For more modern games, it’s really just the amount of this “state” data that has increased.",
"When you play a game there are some parts that are the same for every player at all times. For example; the image for the background or information on how much damage a particular weapon causes. Those are just the regular game files. You get them when you get the game and they don't change. But as you play there are things that need to be recorded that are specific to you and your current point in the play through. For example; your character's name or your current level. When you save a game all that stuff gets written to disk somewhere. When you start the game next time it first loads the stuff that doesn't change. Then when you load a particular game it reads all the stuff in your save file.",
"The computer writes all the infomation about your game into a file. Like where you are in the world, where the monsters are, which direction you're facing, how many bullets and hit points you have, etc. When you load it, it opens the file and looks at all this information and uses it to set up the game the same way it was when you saved it.",
"An analogy: If you're playing chess and need to pack the game away, you can write down a list of where every piece is and whose turn it is, then put the game away and re-set it up later. That paper is your saved game. Video games do a version of this. They take the current state of the game, simplify it down to the details that they need to reconstruct the current state and save those details on your hard drive. (There's usually a lot of details for some games, for others it's literally just a \"the player is at this chapter\". There's compression and a lot of other stuff going on as well.)"
],
"score": [
27,
6,
5,
3,
3
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gvzjjq
|
How do sailboats steer?
|
If the wind is blowing in one direction, wouldn't your sails just propel you in that direction? What if you want to go parallel to the wind direction? I understand sails can move, but wouldnt that just speed up or slow down how fast you go in the direction of the wind?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fss2usn"
],
"text": [
"Sailboats have something called [a centreboard or a keel]( URL_0 ). The keel resists the lateral force created by the wind, helping the boat go forward instead of sideways. That being said, boats at certain points of sails do move sideways quite a bit, even with a keel. This is called leeway. In addition to the keel, sails work more like an airplane wing than a simple pushing object. As you can see in this [image]( URL_1 ), wind pass around the sail creating low pressure on one side, and high on the other. This interaction between high and low pressures creates lift in the sail. The yellow arrow in the image represents to sum of the forces, the red arrow is the forward component, and the green arrow is the lateral component. As discussed above, the keel prevent lateral force, which shrinks that green arrow, allowing the boat to mostly travel forward."
],
"score": [
9
],
"text_urls": [
[
"https://boatingforbeginners.com/wp-content/uploads/2019/01/keel.jpg",
"https://guernseydonkey.com/wp-content/uploads/2019/12/how-sails-work.jpg"
]
]
}
|
[
"url"
] |
[
"url"
] |
gw2imh
|
How did they fit open world games like Zelda and the original Final Fantasy into NES cartridges
|
With some basic Googling It looks like that the max size was around 512 KB. How is this even possible to fit games of this size onto such little memory? What is this magic? Edit: Wow, this absolutely blew up. Thank you everyone for the detailed answers. Several people have linked the Morphcat Games video which I will share here. It is very informative. URL_0 Edit 2: I also did some more of my own research and found this video very informative about 8 bit graphics and processing: URL_1
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fssi7fz",
"fssj3pk",
"fst432c",
"fst46qc",
"fsuj1o0",
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"fssi197",
"fsttgqk",
"fst1bx5",
"fsu2aqm",
"fsusoyo",
"fsus2gq"
],
"text": [
"The game is a grid. Legend of Zelda is 16 screens wide by 8 screens tall. And each screen is a grid of 11x16 tiles. Now let's say there are 16 different types of tiles, then you only need 4 bits of information for each tile, which means the entire overworld of zelda is only 11kb. But 11kb is a lot in the 1980's. They probably used a lot of tricks to make it less than that. How about instead of 16 different types of tyles, each screen only has 4 types of tiles (and those 4 can be different for different screens, so one screen might be sand, rock, water and cave, but another screen might be sand, grave stone, bush, and tree). Now you only need 2 bits for each tile, so your file size is 5.5kb. And maybe you come up with some other shortcuts... like on a desert screen you make \"sand\" the default tile and now you only have to store the data for the rocks on the top of the screen.",
"Old games are like storing a brick and the plan of the house, then tell the processor to copy the brick according to the plan to build the house. Most of the size gain is because the graphics are done using repeating patterns and only storing a little square and telling the processor to repeat it. Modern games are like storing the whole house and its 500 000 bricks. Often even the parts of the bricks you never see because they don't care about size anymore.",
"Short version: *insanely* talented coders doing everything they could to maximize space. I'm gonna blow your mind right now. Take a look at the [intro to SMB1.]( URL_0 ) We'll ignore for a moment the fact that that screenshot takes up more memory than the entire game did. Anyway, take a real hard look at it. Check out everything - the bricks, Mario, the Goomba, the hill, the clouds, the bushes... the clouds, the bushes... *the clouds, the bushes*... Yeah. They're the same icon, just with a new color palette swapped in. All sorts of little tricks like that in old-school programming. And it's not totally dead either! There's still a (mostly European) subculture devoted to slick programming, called the [Demoscene]( URL_2 ). I'm gonna date myself here, but when I was a College Freshman I was introduced to a Demo called \"[The Product]( URL_1 )\" - it's a several minute long music video, all 3d generated graphics, made in under **64Kb**. I just downloaded it and checked - still runs on my fully updated Windows 10 machine, but I know for a while there it wasn't playing nice with new computers so YMMV. So coders are still out there that are capable of doing, frankly, ridiculous shit like that (even though that's nearly 20 years old at this point, it's still ongoing) -- just they don't *have* to anymore because it's assumed most people will have reasonable stats on their computer. If everyone has 16 gigs of ram, who cares if you lose a couple kilobytes? Guys who are programming for efficiency, that's who.",
"All graphical information was stored in 16KiB of memory. This area of memory was divided into sections. The first was a pattern table. The table was 8KiB in size and divided into 8x8 tiles. The table was usually split vertically, half for backgrounds, half for sprites. A pixel was stored in 4 bits, meaning the NES could display 16 colors. The pattern table only stored the lower 2 bits of each pixel. The other two bits were looked up in one of the other two tables. The next table was the \"name table\", of which there were typically 2 but up to 4. A name table is 960 bytes. This corresponds to a 32x30 grid of 8x8 tiles from the pattern table. The top and bottom 8 scanlines weren't rendered on a CRT television, so that memory could be used to hold game data. You can see the effect along the top and bottom edges of Tecmo Super Bowl. A name table has an attribute table 64 bytes in size that maps the upper two bits of every pixel to the lower two bits in the pattern table. There was also a sprite table, or sprite RAM, that used 4 bytes to map the x and y location, upper color bits, the tile index (meaning the x and y location is relative to a given tile in the background), horizontal or vertical flip, and foreground/background. This table was 256 bytes so there could be 64 sprites on the screen at any given time. There were two color pallets of 16 colors each, and the color bytes split between the pattern table and the name or sprite tables indexed into these pallets. One was for the background, the other for the sprites. These two 16 color pallets mapped into a 256 color pallet built into the hardware. If you don't understand all that, don't fret. The whole thing works out like a relational database, where one table maps into another. The data is down to packed bits, so while you have addressable bytes, you had to mask and pick out bits and combine them in registers to get complete values out. The hardware was built around all of this and could do it for you, which is how the system was fast enough to actually render this much data onto a CRT. A cartridge was ROM that basically plugged into this memory space, so the data was already laid out and good to go, the video hardware mapped right onto the cartridge data.",
"It's a trick called indexing. I think the best way to explain is with an example. I have a very long number. Specifically, the number is 55555555522333333344444776666677. Now, I could represent the number like that, or I could say 9-5,2-2,7-3,5-4,7-7,5-6,2-7 This takes up a bit less space (33 vs 28 characters). And so long as you knew that the commas separate this into a list, and that the hyphen separates the number of occurrences from the value of those occurrences, you would be able to take this list and get the original number. All I have to do is tell you (the NES) ahead of time to interpret whatever info I give you in this manner, so that when I put the shortened version on the cartridge, you can get the original no matter what it is. But 33 vs 28 isn't a lot of saved space, right? 5 characters. Big deal. That's only 15% saved. But in fact, that was actually pretty poor compression. We can go deeper. If you look at all the numbers, both for the number of occurrences and for the value of the digit, you'll notice that each of them is single digit. So we can actually shorten it to 95227354775627 Just by slightly altering the rule we give you - that every two digits is a pair where the first is the number of occurrences and the second is the value. Since this eliminates all commas and hyphens, this shortens the first compression by an additional 50%, for a total of 57% overall. But we can get even more aggressive. You see, up until now, each character has taken up an entire byte (this is how strings were encoded as of 1981's 8-bit \"Extended ASCII\", which doubled the number of available characters from 1963's original 7-bit ASCII encoding). So far we've been focusing on just reducing the number of bytes. However, when you get into what the NES sees, our starting number looks more like this (represented in hexadecimal): 35353535353535353532323333333333333334343434343737373737373736363636363737 Our first compression looks like this: 392D352C322D322C372D332C352D342C372D372C352D352C322D272C And our second compression looks like: 3935323237333534373735363237 You've probably already noticed that in the uncompressed number and the second compression, every other digit is 3. That's because the digits 0-9 are stored in the values 30-39 in ASCII. If you look at that and say, \"can't we just get rid of those alternating 3s?\" You'd be 100% correct, and you're catching on to how this works. In hexadecimal, each written character takes up 4 bits, not 8 - so a pair of two makes a full bit. Each set of 4 bits can have a value of 0 to 15 (when it goes above 9, it switches to letters, where A is 10, B is 11, up to F at 15). Since each digit is under 15, we can effectively cut the length in half one more time. What we end up with looks identical to the second compression 95227354775627 Except we know under the hood that it requires half as much information. To prove it, we can convert this back from hexadecimal to ASCII and get: ò\"sTwV' And our total compression is just shy of 79% - basically, 5 times as efficient. ============================= Now, this has all been about compression, but the method I mentioned was *indexing*. Compression is the basic idea behind indexing. However, indexing ups the ante - it's the next level. To explain indexing, the best example I can give is showing approximately how a game like Zelda is actually put together. Let's start with the lowest level: tiles. In NES architecture, a tile is 8 pixels wide by 8 pixels tall, for a total of 256 pixels. Now, if you've ever worked with a color picker in a program like Photoshop or GIMP, you might be aware that modern red-green-blue digital coloring is represented in hexadecimal! FFFFFF is white, 000000 is black, FF0000 is red, 00FF00 is green, 0000FF is blue, and any values in between FF and 00 can be mixed to make a total of 256^3, or 16,777,216, different colors. If you used a computer in in the late 90s or early 2000s, you might recall the computer saying it switched its color mode to \"millions of colors\" upon entering or exiting a game. This is the color mode it was talking about. If you've been doing the math, a color system that represents white as FFFFFF in hexadecimal is taking up 3 bytes for every single pixel. Multiply by the 256 pixels in our tile, and it's taken up 3/4 of a kilobyte. If the NES screen size is 256x240 pixels, or 32x30 tiles, then a single screen is 720 kilobytes - it doesn't even fit on the cartridge. One single screen! However, the NES can't display 16 million different potential colors. It can't even display the 32 thousand colors that the gameboy color was capable of with 15-bit rgb. No, actually, the NES had a curated list of 54 usable colors (if someone wants to lawyer me, it's 432, but for reasons I won't go into, those extra colors come with some deal breaking strings attached and weren't useful very often. They're also not listed out - they're potential tints of the base 54 colors). This list of colors is stored on the console itself - the game gets it for free. However, even if we did have to store it on the cartridge, we'd be sacrificing 1/20th of a a kilobyte in order to reduce the color data by 75% (3 bytes vs 6 bits). Why 6 bits? Because a 6-bit number holds values between 0 and 63, making it the smallest number of bits that can reference 54 different colors. This is what indexing is - by listing out a number of specific items we expect to use and ignoring all the possible combinations we will never use, we can significantly improve how efficient it is to call on the one we need. In this case, we don't need 16 million different colors, we only need 54. So rather than make each pixel choose from 16 million, we spend a bit of space giving it a list of just 54 to choose from. That list is our \"index\". But we can keep going. Because as you probably know, NES sprites are actually 16x16 pixels. This is because a sprite is actually a tilemap - a 2x2 group of tiles. This serves two purposes - first, since certain 8x8 tiles get reused between 16x16 sprites (especially on the background layer where terrain repeats frequently) a fair amount of data is saved there, though I'd have to go through all the sprites one by one to tell you how much it saves. The second is that, because the choice of palaette is tied to the sprite and not the tile, we eliminate 3/4 of the number of times we have to specify which palette we're using. Palettes, you say? Yes. In fact, each pixel does not pick directly from the NES list of 54 colors. The game cartridge defines a list of palettes, containing 4 colors each, that sprites can choose to apply. This means that, by spending a couple bits at the start of each sprite to specify a palette, each pixel only needs 2 bits to take its pick of the 4 colors. This brings the size of each tile down to 64 bytes. This also means that each sprite is just barely over 256 bytes. Even less if it uses the same tile multiple times, like the bridges and raft launch sprites, which are the same two tiles repeated on the left and right side. Now we're at sprites. The overworld of Zelda 1 seems to have 50 possible sprites as far as I can tell, meaning as it often winds up, we need 6 bits to reference them with. So for the purposes of the overworld, it's .75 bytes times the total size of the overworld. Well, for each board, we've got 32 tiles or 16 sprites across, and 28 tiles or 14 sprites high. Wait, 28? We had 30 earlier, what gives? Well, remember that the top 16 pixels are our HUD and don't contribute to the size of the overworld. 16 by 14 sprites is 224 total background sprites per board. Multiply by our .75 bytes per sprite, and each board now only takes up 168 bytes. The overworld itself is 8 maps high and 16 wide, for a total of 128 boards. Multiply that by 168 bytes per board, and our entire overworld fits comfortably within about 4% of our cartridge. Once you add our palettes, tiles and tilemaps, maybe it's closer to 6 or 7%. But even if that's a bit conservative, the indexing I've listed here is definitely not all nintendo did. If it were me, I'd index all water sprites as a single sprite, since the coast can be derived logically from surrounding squares. If a similar thing could be done with cliffs, the index could be reduced from 6 bits to 5. And obviously, not every board is custom. Many have similar baseline features that might be called on and added to after the fact. Either way, I didn't intend to spend hours gushing about this. I'm going to let both our brains rest like the freshly seared steaks that they are, and hope no one notices that this explanation doesn't quite qualify as an ELI5 simply for sheer length.",
"A lot of reused assets. If you look at the dungeons in the game they all look the same, but just rearranged and maybe with different colors. The different colors aren’t even separate files, they are changed programmatically. For that matter there’s other tricks like using black space. The areas that are black in the game are actually just the absence of any assets being loaded. For both Zelda and Final Fantasy they even reused sprites for enemies. So you could have a variety of enemies that just have maybe the color changed about them to differentiate them.",
"**Turn back, this way lies madness.** It is all highly optimized code using weird tricks on top of tricks on top of tricks. The kinds of things where one engineer explaining to another might take an hour to show how 5 lines of code does anything, let alone what the first engineer is claiming they are doing with it.",
"Look up a picture of the first Zelda. The screen is made of little pictures (tiles) on a grid. How big is the grid? I count 17 by 11 tiles. So that's 187 bytes for a screen. How big is the world? If you look up a map, it's 16 by 8 screens. Maybe triple that because of all the dungeons and stuff. So that makes 384 screens which are 187 bytes each, which is 71808 bytes. Still plenty of bytes left.",
"While some of these explanations are alright, it doesn't explain Final Fantasy, Dragon Quest, or a few other larger NES games. Normal NES carts are limited to a ROM of 40KB. For small games like Super Mario Bros., this is pretty easy by just reusing the same pictures. But what if you wanted to make something *bigger* that needed *more storage*? Bank switching. With bank switching, the cartridge has a larger storage than 40KB. This larger size is divided into 40KB chunks, and when something outside of the chunk currently being read is needed, the cartridge switches to another chunk and loads that information for the system to read. Upsides are great, with more complex games! Downside is that the cartridges are more expensive to produce. EDIT: Grammar. EDIT 2: Man I should have read the OP more closely. The maximum storage size for an NES cartridge was 1MB. Along with this, programming techniques to save space were used. Reusing the same graphics information, programming directly in assembly to optimize space saving, and much more.",
"To add onto a lot of these wonderful answers. 1 tactic I've seen that really helps was in paper Mario on the n64 where NPCs were stored beneath the map as shown here: URL_0 There's probably so many little tricks like that used to create illusions that a specific thing is happening.",
"Procedural generation. They can also make images this way which use up less space than images. I think it's called algorithmic art.",
"Programming is actually quite a compact art, as one character of code is equal to one byte. The largest files in a game by a long way are the graphics (with audio a distinct second), and the struggle for game developers comes down to this compromise. The majority of players want good graphics and sound, but also want fast load times and installs. When opting for a small game, the absolute best thing you can do is remove the number of graphics being loaded. Reuse wherever possible! You've likely seen 'generic NPCs' that look the same, but a more obscure example of this is Super Mario, where clouds and bushes share the same graphic. Another popular technique is layering, making use of the Z-index. The background (usually just a generic grass, sand, snow or water) can be replicated as nauseam, with small objects added on top to add variety. Only the smaller additions require addition load and memory. Once you get into 3D, things start getting a lot more interesting. There's a few techniques that can't be used for 2D games, but early 3D games like Super Mario 64 were able to fit in the 32Mb Nintendo64 cartridges by making extensive use of the following: **Field of view rendering**. In short, there's a cone that denotes what the player can see, and anything that isn't visible to the player is unloaded from memory. This allows the same memory to be allocated to other graphical objects. **Tweening**. Characters often move along set paths in 3D games, though when these characters aren't visible to the player, they will teleport to their destination after a fixed period of time. **Cutscene model loading**. Many 3D games to this day still don't have cinematic cutscenes. Instead, as the complex levels or areas load, the characters, vehicles and objects required for cutscenes are often stored 'put of bounds' in an area that is both loaded and intentionally unviewable by the player. These models, along with the player, are then teleported to where they need to be for an in-game cutscene. This approach reduces the need to reload scenery, which makes up the vast bulk of the size (and subsequent time) it takes to load. **Compression**. You don't always need to see a character's face in detail. Maybe they're far away. During such instances, developers will often swap out the player character for a much lower detail version. Some games (like the earlier ones) take this even further by using low-count polygon models for their main characters. Final Fantasy VII is a great example of this. **Load sequences**. Notice how 3D characters frequently need to crawl into tight spaces? This is a clever way to distract the player from the fact that they're being forced to look at a specific, small area for an extended period of time. During this, the rest of the level just outside of view is often undergoing significant changes, though positioned in a way that the player will never realise.",
"First of all, disclaimer: not a programmer, but have been working with videogames for over 20 years at this point (you end up learning a lot through sheer osmosis and, of course, research and banging your head against all sorts of problems). Second disclaimer: will try to simplify as much, but is probably going to be a very lengthy post. First thing, it's important to understand some specifics about older console hardware like the NES/Famicom: these were very dedicated chips made for very specific functions, in very primitive ways. How much? When you made a game on the NES/FC, the first thing you had to do was pick if you wanted vertical or horizontal scrolling. So if you were making Super Mario Brothers, you'd pick horizontal because your character was going left to right. But if you were making a space combat game like Xevious, where your ship goes up, you'd pick vertical (later games used tricks and special expansion chips on the cartridges to make more elaborate games, before anyone asks how Super Mario Bros. 3 managed to let you scroll both ways, but if you must know more about this, you can't do better than watching [Retro Game Mechanics Explained's video]( URL_0 ) on the subject. Anyway, back to the hardware. So when you were making a game for that platform, you basically had a memory chip that held all the image data - literal tiles with parts of images you'd use to assemble backgrounds and sprites. These were kept small by only have (if memory serves right) 3 color values - but the colors themselves were not assigned, just the fact that you had 3 different colors. These colors were then assigned with a palette - which is why the clouds and bushes in Super Mario Brothers look the same except for color - they reused the tiles, but assigned different palettes to them. So right there we already saved tons of memory - the tiles are small, the palettes had limited colors, we are using a few BITS (a small bunch of literal zeros and ones) instead of several bytes (sets of 8 zeros and ones) to have this information stores, since they are in preassigned banks that do not require special instructions since their use is completely dedicated. So let's take a step back and think about the differences between modern game creation and what was done on the NES/FC, shall we? Nowadays, when you create a \"game level\" - and let's even think on a retro game, something that looks like an NES game, a sidescroller platform title, a creator will usually have a dedicated tool, a mapmaking application that lets him \"paint\" the game and save it as a dedicated file with all the instruction for the application to interpret it. The programmer gets to use programming languages like C++ to write complex instructions and then compile them into something that the machine can interpret. But back then, you were basically forced to use the assembler language for that chip - that is, give direct instructions that would amount to \"get the value on this specific address on the memory, and add this, then transfer it to this address\". Since the hardware was made specifically for these games, a lot of these were set up as to be extremely dedicated to make the game work - but it also meant that you were somewhat limited on the complexity of what you could ask the hardware. So, by the same rule, when people made music for the NES/FC, they didn't just \"upload a file with sheet music\", you literally had to PROGRAM the sound chip with instructions - if you are curious about the sound part, I highly recommend [the 8-bit Guy's explanation on Oldschool Sound]( URL_3 )). So the same goes for the level design in Super Mario Brothers. You basically started by setting some rules - like: a coin block is made of these tiles, set up this way, when you hit them, they will continue to spawn coins for x amount of time, ground tiles behave this or that way etc. After you have these base behaviors for the building blocks, you had a set of instructions that said: ok, for this level, you start with a floor block for 8 tiles, then I want 1 tile on the 4 row from the bottom, then 2 blocks, spaced 2 apart, etc. etc. This had to be programmed manually, mind you, and it was a pain in the ass. The excellent [I am Error]( URL_2 ), by Nathan Altice, actually shows samples and explains a lot of what I just briefly explained above. This data that is used for levels is so raw, that you can trick the game into read other random data and treating it as level data, which is what causes the infamous \"Minus World\" glitch - the game is trying to read non-map data as if it was a map table, causing bizarre levels to be drawn (again, for a video that can explain much better than I can, [this]( URL_1 ) can be very illustrative). So... I hope this has helped some in understanding why these games take so little space. Having a limited set of instructions, working on very dedicated ways, you can do some amazing things with very little data. Nowadays, game creators not only use much more elaborate and higher-level computer languages, but also dedicated tools, middleware and many other tools that make game making a lot easier and more streamlined... but would be almost impossible to implement with the way the older consoles were made."
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"http://theproduct.de/",
"https://en.wikipedia.org/wiki/Demoscene"
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[],
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"https://www.youtube.com/watch?v=wfrNnwJrujw",
"https://www.youtube.com/watch?v=Hv_h_R3o9r8",
"https://mitpress.mit.edu/books/i-am-error",
"https://www.youtube.com/watch?v=q_3d1x2VPxk"
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|
[
"url"
] |
[
"url"
] |
gw7i2l
|
How do emergency broadcasts get to everyone's phone, TV or radio? How come your phone always knows to give you a notification when they're sent?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fstbs11",
"fsthn4y",
"fste5rt"
],
"text": [
"because the goverment has an agreement with phone companies, radio stations, television providers, that let them push out those notifications. So when the time comes, to put it simply, all the government needs to say is \"Hey Companies, yknow that emergency system we made you create? We need you to put out this message\" So the government itself isnt directly tapping into your phone, tv, or radio station. Theyre telling all those entities that you're using to send the message to you.",
"It's already been pretty well answered but radios are even cooler! You know that annoying ear grating sound before and after the message? It's acting pretty much Like a dial-up modem and using sound to communicate digital data. Radio stations have gear built into their equipment for emergency broadcasts and are listening to their neighboring competition radio stations. So a single station say at a government facility can put out the original broadcast. Radio stations within the origin's radius will pick up that data at the beginning (which gives it some info) and replay the message. As those replay the message More stations pick it up. The data is also used to make sure radio stations that have already played it don't play it again, so it'll be like \"Broadcast 12345\" and the equipment goes \"I already played 12345, ignore.\" Radio emergency broadcasts literally fan out like a fire until all stations have played it.",
"The emergency broadcast is special. You do not do them by sending a message to each phone but to send a special message from the cell tower to all phones connected to them and all receive the message at the same time. You likely transmit it multiple time so all devices get is. You can can have the tower sent it too all-new phone that connect to the towers later, of course with some max time limit The system is set up in cooperation with the phone companies and is legal requirement for them to operate the cellular network. The system is set up so you can send a message to all devices in a specific geographical area or even all everywhere connected to the network. The system will be limited by county the government of one country can only send it to phones connected to towers in that country."
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|
[
"url"
] |
[
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] |
|
gwgs1j
|
Why does it take a powerful PC to run a nintendo 64 emulator even though the 64 is relatively much weaker
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsutte4",
"fsus845",
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],
"text": [
"It's like having to read a book in a language you are not familiar with. Your mind is working overtime both to understand what you are reading and translating it from the unfamiliar language to your native language at the same time - the translation slows things down. The PC doesn't understand N64 language directly, so it needs a translator (the emulation software), but that translator also needs a lot of attention, so it slows the PC down to both get the N64 code translated, then the translated code still needs to run.",
"I’m sure someone else will explain it better but I believe in order to emulate a game you need to emulate the entire machine, which takes up a lot of CPU etc.. For example a PSOne isn’t exactly high tech these days but you still need to emulate the entire system. Someone else will do a better job of explaining this :)",
"It does not take a powerful PC to run a Nintendo 64 emulator. People [were running]( URL_0 ) N64 emulators on average medium spec computers back when N64 was still new. However, it is certainly possible to emulate the system more and more accurately, which usually takes more resources as accuracy improves."
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"https://emulation.gametechwiki.com/index.php/UltraHLE"
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|
[
"url"
] |
[
"url"
] |
|
gwpr2q
|
What can a NAS do that a regular computer can't?
|
I'm asking because I'm looking for a way to store movies and TV shows and people seem to like this NAS thing. However, from my very limited knowledge it just looks like a PC cabinet with a (for a PC) slow processor and (for a PC) not a lot of RAM. Some of the Synology ones cost way more than a PC with the same specs would, and a PC has places to put HDDs just like a NAS does. So what am I missing?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fswgcom",
"fswlbhr",
"fswhtz3"
],
"text": [
"NAS devices are typically designed to run it's storage drives for very long periods of time, whereas a normal PC hard drive is not designed to be able to read/write 24/7. NAS drives can also be run in various RAID setups to prevent data corruption, thus making it a more sensible option for those hefty PleX server type setups.",
"You pay for the compact design, durability, RAID features, and the software. You can build your own NAS from an old computer with [FreeNAS]( URL_0 ).",
"A few things. That slow processor, and small amount of RAM means that it uses very little power. For something you keep running 24/7 like a refrigerator that is important. It’s also very quiet. You can connect all sorts of things to a NAS, like tablets, phones, your PC, smart TV, and they can all -share- that data store. Put your dvd collection in it and you can watch anything on any smart tv in the house, no player needed. Also, you can use technology that is not available on a windows PC, such as alternative file systems, with extra features, like ZFS for example, which protects your data from bit rot. If you store things long term that is great. You can also use multiple disks to protect against failure. RAID is a common technology used in NAS systems. It has several ‘levels’ that offer increasing amounts of resilience in exchange for using some of your capacity. And, if you really want something beefy, you can actually use a full on PC and build your own NAS with some free software like FreeNAS, which is what I have done. Mine is a box with 16 disks in it, and up to six of those disks can die without taking any of my files. A regular pc can’t really do that."
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|
[
"url"
] |
[
"url"
] |
gws5vc
|
How do “infinite” video games work? How does the game understand the pattern that must be used to create the game, and is it possible to reach a point where the game will basically loop because it won’t be able to create any more new levels/road?
|
Take Tiny Wings as an example. You control a bird which has to slide on hills to get height and pass from island to island. The game is a “survival score” (you have to survive as long as possible and you get a score which increases the more you survive) kind of game and will go on indefinitely. How does this work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fswvsha",
"fswyey1",
"fsx268d"
],
"text": [
"You basically keep on throwing some dice, and the result is interpreted as what to do next. Eg, you get a 5, and that means you're going to make a mountain. You throw some dice again, and that determines the mountain's height. And so on. You can have effectively infinite worlds this way, but on large scales they tend to be rather bland. It's easy to make vast tracts of land, but hard to make them interesting. You can easily have endless variations of hills, grass and lakes, but after enough of that you'll keep on getting more and more of that, while it won't repeat itself it still won't look very different from the previous thousand iterations.",
"In video games, we use a variety of tricks to create illusions for our players. In most infinite games, the trick is that the player never actually moves. Instead, we move the terrain and the background to create the illusion of movement. Next, we take advantage of the fact that the player will never go backwards. Any terrain, obstacles, etc. that leave the back of the play area are deleted so they don't take extra memory. Finally, we use some algorithms and random numbers to randomly create whatever the player will run in to next (an island, terrain, power ups, etc.) So the process is randomly create stuff, scroll it past the player, then delete it. Since we delete everything we create, we don't use extra memory and can do this forever.",
"Generally they have an algorithm that can turn some random number into a local spot on a map, usually with something that takes into account spots nearby. Then the game basically takes your location, finds maps coordinates that it needs to draw, and essentially encrypts this (makes a hash). This creates a predictable seemingly random for every spot that you can also go back to. Generally yes, it repeats, but in games like spore I know they made it so it was impossible to actually see that, you'd have to play for billions of years before you actually hit the repeat."
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6,
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|
[
"url"
] |
[
"url"
] |
gwujxz
|
How does The LEGO Movie look so realistic?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsx9xek",
"fsxcxx8"
],
"text": [
"Computer technology is really good at making plastic look real, and since legos are make believe they don’t have to follow gravity or similar rules. I saw a YouTube video talking about how the creators tried very hard to make it look stop motion by doing things like removing motion blur.",
"Some good commentary on it here, I think Corridor Crew does some other videos that touch on the LEGO Movie: URL_0"
],
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"text_urls": [
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"https://youtu.be/D7Cv7x6jjYQ"
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}
|
[
"url"
] |
[
"url"
] |
|
gwv87q
|
how does phone's fingerprint scanner work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsxhpt2"
],
"text": [
"Most phones use what is called a capacitive scanner. On the top is a highly scratch-resistant sapphire glass lens that protects the assembly and focuses the sensor. A steel ring surrounds this, waiting to detect your finger's pressure. When that is triggered, the capacite sensor activates and essentially takes a high resolution picture of your fingerprint. This print is compared against what you have on file, and if it matches, the phone unlocks. The \"high resolution picture\" is created by sending a very small electrical current through one's finger and back into the conductive plates on the surface of the scanner. Because of the ridges, curves, bumps in our fingerprint, this creates a unique signal, or set of data, received by the plates on the scanner. Once captured, this data can be saved for comparison at a later date. The clever thing about this technique is that it is very difficult to replicate the signal. The results can’t be replicated with an image and is incredibly tough to fool with some sort of prosthetic, as different materials will record slightly different changes in charge at the capacitor. The only real security risks come from either hardware or software hacking. TL;DR: The phone sends an electrical current through your finger which results in a picture of your fingerprint. This picture is then used to compare future unlocking requests. Sources: [ URL_1 ]( URL_1 ) [ URL_3 ]( URL_0 ) [ URL_2 ]( URL_2 )"
],
"score": [
20
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"text_urls": [
[
"https://en.wikipedia.org/wiki/Touch_ID",
"https://www.androidauthority.com/how-fingerprint-scanners-work-670934/",
"https://www.imore.com/how-touch-id-works",
"https://en.wikipedia.org/wiki/Touch\\_ID"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
gwxg94
|
why is it that gigabit internet is not 1000mbit but caps at 940mbit?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsxthns"
],
"text": [
"In most cases it is because there is overhead to get that speed, so carriers who offer gigabit sometimes say 940 because that's the fastest your information goes, they tack on another 60mbps to help get your data through their network properly. But this is really just best effort. The actual medium of ethernet depends so many factors that they cant guarantee you will get those speeds anyways. If you dont have the right wireless or wired router you wont get that speed. If you have the incorrect ethernet wires or wrong network cards you wont get those speeds."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx2fiv
|
How can I explain my partner, LIKE HE'S FIVE, that Bill Gates is not putting chips inside people?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fsyn7m1",
"fsymv9i",
"fsyo1li",
"fsyn8az",
"fsyogbm"
],
"text": [
"You can't reason with conspiracy theorists. It's pointless to try. If he gets aggressive, get out.",
"Why would you want to prove a negative, that's very hard. Ask him to show some solid evidence for the facts he's claiming.",
"Ask him about the chip’s specs. Like battery capacity, CPU power, physical size, wireless protocols to communicate information, etc. And if based on these questions chip starts to look like a big one - how exactly this chip is delivered with a vaccine? once you get to the technical level of the “how” question, a lot of people start to understand that things do not add up.",
"You can't reason with stupid. Heard the expression, \"never wrestle a pig in mud\"? Applies to conspiracy theorists. They believe what they want not because there is evidence (because there isn't), and won't change their mind when presented with actual evidence anyway. See flat earthers. Anti vaxxers.",
"Your partner is broken. Find the receipt and return him, hopefully you'll at least get store credit."
],
"score": [
26,
22,
20,
8,
6
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx4az0
|
How people made ice before refrigerators existed?
|
Technology
|
explainlikeimfive
|
{
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"text": [
"There was an entire industry of harvesting and importing ice blocks. Crews would cut up river + arctic ice, pack it in straw and other insulators, and ship it to towns for sale. The delivery men were called appropriately 'icemen'. With adequate insulation the Ice would keep for a surprisingly long time. You could buy ice well into the summer so long as the supply lasted. The term ice-box is often using as a synonym for a fridge today, but originally the term described a wooden cabinet that was literally a box you'd put ice in that would keep your food refrigerated. Once commercial fridges become ubiquitous the icemen became obsolete.",
"They either imported it or stored ice from winter in underground storage structures. If you’ve seen Frozen, there’s a song at the beginning showing ice harvesters and one of the characters is an ice trader - they’re not making a joke about yokels farming ice rather than useful foods, it was a very real industry for a while. It’s also where sweet Iced Tea in southern states came from too - to make iced tea you needed three luxury ingredients: Tea, imported from India, Sugar imported from the Caribbean, and Ice imported from the North/Canada and then stored. It was absurdly expensive, particularly in the summer, so serving it to guests was basically showing off you could spend a huge amount of money on light refreshments like it was no big deal.",
"There's a process for making ice that people in the middle east have had for more than 2000 years called \"night-sky cooling\". In the evening hours, they would pour water into long stone pools no more than 2 feet deep. Places, like deserts, with little water vapor in the air don't retain heat very well at night. Not only that, but on a cloudless night, the water in those pools would reflect light out into space. This reflected light radiates heat away from the water, allowing it to form ice, even in ambient temperatures as high as 40°F. People would harvest the ice before dawn and take it to a yakhchāl, or \"ice pit\". Insulated, hollow domes with deep, subterranean holes, where ice could be stored for months.",
"Ice was imported or stored. With proper insulation a big ice block could be stored for several months. But the process of collecting ice for use in summertime and especially transporting it to warmer climates was not common and rarely saw use before the 1800s. Even then it was seen as a luxury item. Drinking a cold sweet drink in the summer was something you would do in front of everyone to demonstrate how wealthy you were that could afford to import both ice and sugar, and often tea as well. Before refridgerators people used other ways to conserve food. Drying, pickeling, fermenting, salting, canning, etc. or a combination of them.",
"Regarding ice being eaten in Turkmenistan before the invention of freezers, there's an actual historic form of ice house called a [yakhchāl]( URL_0 ) that works as an evaporative cooler. The walls are thick and heat resistant, while water evaporation inside the building lowers the interior temperature.",
"There were industrial freezers as far back as the 1850s, but it would be another 100 years before the technology became feasible for residential use. Before practical artificial refrigeration, ice was a luxury that had to be (quickly) shipped from somewhere cold or stored in vast quantities in insulated underground ice houses during winter for use later in the year. Turkmenistan is mountainous in some areas, which would help provide a more local seasonal ice source.",
"In India, during my young days, there were ice factories run by water/ammonia system. Not sure how, but they produced large blocks of ice which was transported on the back of bicycles. They are cut up and kept in boxes with saw dust so it will not melt. I remember buying ice pops from guys who sell them in the back of their tricycles which are embedded in saw dust. How times have changed! This is early 70s!.",
"In some places people would harvest ice from glaciers and haul it down. There’s a cool film about one of the [last ice merchants.]( URL_0 )",
"Check out the Ice King, founder of the Ice Trade, [Frederic Tudor]( URL_3 ). In 1806 he sailed a block of Ice cut in New England from Charleston SC to Martinique. In fact, a majority of Ice around the world was harvested from ponds and streams in New England during the winter months and shipped around the world. The most famous ice, though, came from [Wenham Lake]( URL_5 ) and the Wenham Lake Ice company, founded in 1844. It was famed for its purity and longevity due to trapped air within the ice. It was so revered that a Norwegian company renamed the lake, Oppegård, so that they could sell the ice in Norway as homegrown. The Wenham Lake Ice company was even awarded a [Royal Warrant]( URL_1 ) from Queen Victoria. But even the ancients could make ice (and in the desert too)! [These are ancient Persian Yakhchāls]( URL_4 ) (Ice Pit) that would make ice in hot arid climates. Ice was well known to Middle Eastern cultures and after the [battle of Hattin]( URL_2 ) (portrayed in the movie Kingdom of Heaven), Reynald of Chatillon was [famously offered iced Rosewater]( URL_0 ) as a sign he would not be executed, but refused the drink!",
"There were several lakes in Michigan where businesses cut giant blocks of ice and import them out for profit. The giant blocks apparently takes longer to melt, so you're able to transport it into the desert and hot climates.",
"Mostly they'd stock up by harvesting blocks from frozen lakes in winter. If they packed a well insulated warehouse full of big blocks of ice, it'd stay frozen even through summer",
"In all seriousness, the opening scene of Frozen is a simple example of how this was achieved!",
"[If you can think of a better way to get ice I would like to hear it.]( URL_0 )",
"They bought it from the ice store, who shipped it in by rail from places like Alaska. 7-11 started as an ice store.",
"It wasn't so much made but harvested. Cut the blocks big enough and insulate them and they can last a fair bit. Not nearly as efficient as refrigeratoration but it can get the job done.",
"My apologies if anyone else already mentioned it (I skimmed the comments and didn't see it) but there's a great little documentary series that was on Netflix a while back called \"How We Got To Now\" that had an episode about ice that was incredibly informative. The whole series is fascinating actually."
],
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354,
71,
66,
41,
21,
14,
10,
10,
6,
4,
3,
3,
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[],
[],
[
"https://youtu.be/z2eLl_WA7CQ"
],
[
"https://en.wikipedia.org/wiki/Raynald_of_Ch%C3%A2tillon#:~:text=Saladin%20handed%20a%20cup%20of,Raynald%20drank%20from%20the%20cup",
"https://en.wikipedia.org/wiki/Royal_Warrant_of_Appointment_(United_Kingdom)",
"https://en.wikipedia.org/wiki/Battle_of_Hattin",
"https://en.wikipedia.org/wiki/Frederic_Tudor",
"https://en.wikipedia.org/wiki/Yakhch%C4%81l",
"https://en.wikipedia.org/wiki/Wenham_Lake"
],
[],
[],
[],
[
"https://www.youtube.com/watch?v=gm5We9q00Lg"
],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx73r5
|
How come music live records sound worse the better technology gets?
|
When listening to live recording from 70's and 80's, even early 90's, they usually sound great, while current live recordings usually sound awful. Especially when it comes to rock/metal music.
|
Technology
|
explainlikeimfive
|
{
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"text": [
"Because \"live\" albums are not always recorded live. Take the album \"Stop Making Sense\". Talking Heads assembled a touring band, rearranged their songs for that band, and performed in front of live audiences with that band. Then, they went into a studio and recorded the touring arrangements, adding just a little audio from the live performances. You get the feel of a live performance, but the quality of a studio recording. As a counter example, take the album \"Joe Jackson Live 1980/86\". This album was actually recorded at live shows, and frankly it shows - the sound quality is much worse than Joe Jackson's studio albums from the same period. It's not bad - he knew he was recording and made an effort - but not as good as his studio efforts.",
"A lot of it is survivorship bias. Live albums \"in the past\" often sound better because you're only listening to the good live albums, the shitty ones falling to the wayside. Meanwhile contemporary live albums don't have enough history yet to separate the \"classics\" from the crap. For every \"Frampton Comes Alive\" and \"Get Yer Ya Ya's Out\" there's a dozen \"The Beatles at the Hollywood Bowl\" and \"Got Live If You Want It\".",
"My guess is with the progress of technology, comes laziness. In the 90’s, when they were going to tape a live show, it would be a high budget endeavor that included proper set up before the show. Now, any meathead with an iPhone can record a shaky video of a concert with terrible audio. Professional recordings of live shows have gotten exponentially better than in the past, but they can be hard to find when you have to sift through all the garbage because of how easy it is for anyone to record a video now.",
"Others have touched on important factors, like obviously you'll have better quality on a planned live production where each instrument is captured individually and then mixed in a studio vs a single microphone in the back of the room, but it's also noticeable in 3rd party recordings (known as bootlegs back in the day, but ubiquitous now). All the way through the 90s recording a concert to listen to or distribute later took a bit more planning (Though as tape recorders got smaller it became easier). Due to this many of the bootleg recorders actually had a background in doing it and lots of sly techniques like splicing lines leading to the soundboard or an idea of how to best possition microphones to get the best sound. If it still exists in nearly as much popularity I'm not aware, but the bootleging culture used to be fairly large to the point they developed their own albumn covers for the recording which were sold. (Most of the current popularity of this practice still revolves around trading/collecting older music as far as I'm aware). These were dedicated people who understood and appreciated audio. These days most live recording not commercially produced are simply done with a cell phone, the practice of smuggling in professional recording equipment is not nearly as popular. These recordings first have to worry about compression from being recorded digitally, the relatively low quality microphones, and bad positioning (How many videos of live songs have you seen where they were recorded near an obnoxiously loud fan for example). This isn't to say there are no modern high quality fan recordings, just it's a lot less common. A guy I work with has been big into bootleg recordings since the 70s and has created some of his own. Some of the stories he has involved a lot more effort than bringing in a cell phone. Tldr; fan recordings used to be harder to create so those willing to go through the trouble put more effort into ensuring they captured the sound as well as possible.",
"Basically, a lot of \"live\" albums are actually recorded in the studio. They take the live track, and overdub studio tracks on top of particularly bad parts of the recording. URL_0 The better it sounds, the less live it usually is.",
"3 years of live sound engineering experience here. There’s lots of different variables that go into “recording” a live album. To answer the best I can, I would need to hear two specific examples, one from 60/70/80s, one from now. What I can say is that, the louder a show is live the worse a true live recording is. This is because of two reasons: 1, mic bleed: imagine your kids screaming in the background of a conference call you’re on at work. Same concept. Drums are looouudd! You can typically hear them through every mic on stage. Guessing here; With the better mics of today those bleeding sounds could be clearer. 2, the louder the show is the worse it will sound at lower volumes or different venues/spaces. This is thanks to the mixing the sound guy has to do to keep these blaring sounds in check. I’m pretty young, so I’ve never been to a concert from the 60/70/80s, but I can assume the technology didn’t allow people to take it to crazy high volumes without hurting. If you’re talking about live shows posted without any remixing, a show that was originally quieter will sound significantly better at “home volume” The band I work with doesn’t do any live recordings, and we have a different studio guy, so I’m definitely not 100% here. Making a series of educated guesses. Taking a comment the top redditor said, it is half-true. Anything re-recorded after the show WILL end up sounding better than the original; that doesn’t contribute to the poorness of a poor-sounding modern live recording. Especially vocals, it is very easy to get it “live sounding”. Mobile formatting etc.",
"I think some of it comes from the philosophy of what the artists want to convey. Lots of the 70s-80s bands only planned on releasing one or maybe two live albums, and took the best version of a song played over a tour, while most live recordings today take a \"warts & all' single concert recording that presents a more singular moment in time, and do many more releases. (Speaking from a primarily jam band perspective here)"
],
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65,
42,
11,
8,
4,
4,
3
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"text_urls": [
[],
[],
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[
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],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
gx776c
|
Why does auto-fill in search engines sometimes drop out the result I intend to type as I type more of it?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fszlq4q"
],
"text": [
"Generally speaking, when the desired result pops up, people *stop* typing more of it and just go right to the result. After all, if what you need is right there, why would you need to continue typing in more of it. Ergo, if you continue typing even after that result shows, then that isn't the result you wanted (otherwise you would have selected it), so it discards that result."
],
"score": [
38
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx99eb
|
How does spinning work? How are short cotton and wool fibers spun into a single thread for weaving, sewing, and making textiles with?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft03qn4"
],
"text": [
"Some fibers are easier than others. Each strand isn't smooth like a human hair. There are microscopic roughness and microfibers tangled into them. When you spin them, you're smashing them all into a tangled mess, like headphones in a pocket but 10 times worse. The tangled fibers hook onto each other and hold the larger thread together. The same thing happens when a wool sweater is shrunk. One way to try unshrinking wool is to wash it in hair conditioner and stretch it. The conditioner lubricates the fibers and let's them slip back apart."
],
"score": [
12
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx9c34
|
How do MFA/2FA work without internet connection?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fszuh21"
],
"text": [
"The device contains a clock. The displayed PIN is the time, encrypted with a key that you do not know, that's why it seems random. Every token has a unique encryption key. The system on the other end knows the key, as part of the setup process, so it can check that the encrypted time is the right time for that individual device."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx9p9f
|
what is the diference between a 10 dollar mouse and a gamer one?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fszwkvd"
],
"text": [
"More consistent and tactile mechanics (yes it makes a difference) re-mappable buttons, more of them to begin with, better build quality, less Bluetooth lag, etc."
],
"score": [
6
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gx9smz
|
What do companies "get" out of spamming people with emails? Most people delete or ignore.
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"fszx18k",
"fszxrf4"
],
"text": [
"It's true that the vast majority of people delete, ignore, or never even see (it get filtered). But the cost of sending the email is also basically zero. If it costs them $100 to email a million accounts, and then they can scam one person out of $1,000, they've made a $900 profit. Plus, there's an argument that the obviousness of spam emails is a plus. Only really gullable/desperate people respond, so they scammer spend all their time on easy marks.",
"Even if you do delete and ignore it, when it becomes time to, say, buy a car, you'll remember the name \"Carmax\". Even if the message is spam, some things stick."
],
"score": [
5,
3
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxcpig
|
What do updates which solely ‘improve system performance’ actually do on a practical level?
|
I just updated my PS4, and the update description was ‘improved system performance’. What have the devs done which makes my system performance improve? Will I notice it ?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft0ghfa"
],
"text": [
"You probably won’t notice it, honestly. These types of update usually deal with one of four areas. Processor (CPU)/Graphics (GPU) - updating or changing code to make more efficient use of the processor. For example a “single threaded” (runs on 1 core) process might be changes to “multi-threaded” (runs across multiple cores in parallel). Memory - using RAM (the computers short term memory) more effectively or efficiently. Storing more in RAM so it doesn’t need to be read from (slower) hard disk. Change how much memory is allocated and when. Etc. Disk - more efficient or effective use of storage. Better compression, better day layouts, etc. Firmware - in some cases it may be a firmware update which literally just makes better use of the hardware you already have. By sending it instructions and reading data more efficiently or effectively. All in all, it means that at a very detailed level they’re doing some set of operations more efficiently. Doesn’t sound like much, but adds up."
],
"score": [
8
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
gxcsb4
|
Would it be possible to hook up a drinking fountain to something other than a water line so that something else would come out, like Kool aid?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft0gizb"
],
"text": [
"Yes. Easily. Beer taps in bars do this. Soda dispensers in fast food joints do this. Instead of a main water line, it would just draw from a vat of whatever liquid you wanted."
],
"score": [
4
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxeyxv
|
What is a container in computing? What is it used for and how does it work?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft1qx8y"
],
"text": [
"A container is a sort of sandbox for a program, collection of programs, or damned near a whole operating system or Linux distribution (for the specific case of Linux obviously) designed to provide the illusion of a private operating system to the program(s) involved. For longtime Unix users I tell them that a container is like using chroot but at the next level. Certain resources or identifiers in a system are normally considered to be universal. You couldn't possibly have 2 different programs with the same PID number because otherwise they would be the same program. You couldn't possibly have 2 different programs each ask what the IP address for the system is and both of them get different answers, or maybe one of them is told there's no internet access at all. You can't have /home/murdock1024/Documents exist for one program and not exist for another (though one program might get a permission error and the other has permission, that's okay). With containers we change how the system works to make it so that these strange things can happen. Though the Linux kernel that booted up is running and managing all these applications, it is telling each one a different thing about what is normally considered system-wide information. This provides good isolation and security advantages without the CPU overhead and RAM dedication involved in running ordinary virtual machines. The machine running many containers doesn't have to provide hard limits and dedicated RAM and CPU to each one - the operating system can see all the programs running in each and give them the flexibility to use whatever is available. If you have a Linux system, there is a command called 'unshare' that can be used by a knowledgeable administrator as a foundation to make custom containers. It's definitely not for ordinary users to play with, but if you run `unshare -n sh` you'll get a fresh shell but with no internet access - one of the scenarios I described above."
],
"score": [
3
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxgsa2
|
Why there is an electronic chip on Nutella jars?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft1aar6",
"ft200vp",
"ft1d4xr",
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],
"text": [
"What you're seeing is most likely an anti-theft RF tag. Nutella probably gets stolen a lot in that store. Stores will put those on products to make the alarms at the front of the store go off unless it's deactivated at the register.",
"Many companies are going to rfid for inventory taking among other things. Why count jars when you can immediately know how many are on the pallet that just went though the dock door and all the mfg info tied to them.",
"Is it a chip or a flat sticker with a metal coil in it?",
"The disadvantage of a barcode is that it requires to be visible when scanning it. That is why there are multiple beams of light on the counter in the hope that something gets reflected which looks like the return signal of a barcode and then can be interpreted as such. NFC chips don't have that disadvantage, they are activated whenever in the range of the electromagnetic field of the reader. If a shop promise a better shell position for products which have the NFC chips in this, then the manufacturers will take the cost of it to allow better sales for it.",
"I believe is to use non-optic, but radio based scanning systems. So one can checkout items just by placing them in the back at a self checkout counter."
],
"score": [
78,
10,
8,
5,
4
],
"text_urls": [
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxhjm1
|
why do some pictures online load top to bottom (line of pixels line by line) and other go from blurry to clear?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft1h8vk",
"ft1zazm",
"ft27il1",
"ft26h9y",
"ft2ce9o",
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"text": [
"Because these are two different strategies to load images. In strategy A you break down the image data into small pieces and send each piece one by one. As soon as a piece is received it shows up on your screen. Typically the pieces are sent such that the top most part of the image is sent first. In strategy B you keep multiple copies of the image in different \"resolutions\" or \"quality\". The lower the resolution the more pixelated or blurry the image. In this case, the website is smart enough to detect your internet speed and send images of the appropriate quality. Initially it sends the worst quality image and slowly the better quality image is loaded. This is seen on the screen as going from blurry to clear. PS: This is highly ELI5'd. The actuals may be slightly different",
"When an image starts blurry and becomes more clear, you're seeing one of two things. First, it could be either a [progressive JPEG]( URL_0 ) or an interlaced PNG. These are both ways of saving an image so that it first loads a low-res version of the image, then progressively higher-res versions until you have the full image. Roughly the way it works is this-- Imagine you have an image with 1000 pixels. First it sends every tenth pixel, which is enough to render a blurry preview of the full image. Then it sends the pixels halfway between the previous pixels, for a higher-res preview. Then it sends the pixels halfway between all the previous pixels, and so on until it's sent all of them. Images saved this way don't compress as efficiently though, so it's not commonly used. Second, if the images are in a 3D app like Google Earth, what you're seeing are [MIP maps]( URL_1 ) loading. 3D textures are almost always stored at multiple resolutions, so the renderer doesn't have to waste video card bandwidth slapping high-res textures on objects that may be only a few pixels across. They load in the lowest-res MIP maps first (because they load the fastest), then higher and higher res ones until the ideal MIP level is loaded for your current view.",
"Follow up question: I've seen images loading up bottom to top before. What's the deal with that?",
"It's nice to see both methods being explained here, but the actual question, of WHY this happens isn't answered. I personally don't know the answer for sure, but from my days in school I remember it's really just a choice by whoever makes the website, right?",
"Not yet mentioned in this thread is lazy loading. In order to speed up websites developers often “lazy load” images by only loading high quality images once a user scrolls that section into the viewport. The initial page load will typically load in an extremely low quality version of the photo that is a small file, then when the user scrolls it into view it will swap to the higher quality image.",
"Its partly to do with image compression. Some compression methods just store the instructions to create the image. Usually the simplest way to create the final image is line by line and the computer shows each line as it's being made because that's all it has to show. Other compression methods store a low resolution version of the image along with the instructions the add detail to the image. The computer still has to create the final image but in the meantime it can show the low resolution.",
"How are you seeing images load in these days? I haven't experienced that since AOL dialup era.",
"I remember in the 90's having progressively loading images on webpages was a big deal since everything loaded so slowly.",
"JPEG is the most common image file type online and it has two formats: progressive and standard. Standard is just a collection of pixels in order, from top to bottom. Progressive actually has different versions of the same image in the one file, from low quality to high quality. Now as to the why. Standard was original defined in 1992 and is broadly supported by browsers, many of which no longer even exist. It is often the default saving format for many image editors. Older web browsers, like say IE6, will not display progressive images until they are fully loaded, negating the point of progressive entirely. These days all modern browsers support progressive and it is the superior format for websites because it gives a pretty good image in half the time, and it also preserves website structure better because a fuzzy image is already in place before the standard format is half loaded. Other image types have interlaced formats, like PNG."
],
"score": [
3302,
2403,
31,
24,
21,
13,
5,
3,
3
],
"text_urls": [
[],
[
"https://www.liquidweb.com/kb/what-is-a-progressive-jpeg/",
"https://en.wikipedia.org/wiki/Mipmap"
],
[],
[],
[],
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxl2cy
|
In the days where people could smoke on planes, all cigarettes would have to be put out if the plane went through lightning. Why is this?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft2qdok"
],
"text": [
"I would guess in case the oxygen masks came down, would be bad to have a burning ember nearby."
],
"score": [
5
],
"text_urls": [
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxmr7j
|
Why are there weird(sometimes coloured) lines when a camera takes a picture of a computer/TV screen?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft2vjzj"
],
"text": [
"URL_0 The screen displays the image as a grid of pixels. The camera captures the photo also on a grid of pixels. The pattern occurs when the two don't align properly, so each camera pixels can pick up a mix between nearby screen pixels."
],
"score": [
8
],
"text_urls": [
[
"https://en.wikipedia.org/wiki/Moir%C3%A9_pattern"
]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxo9um
|
How can bots like !remindme bot simultaneously scan through thousands of comments posted every minute under many different posts, in different communities?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft3kacl",
"ft3ukt9"
],
"text": [
"Because it's not a single entity. Think of it like a (massive) company instead. There are a large number of workers, each assigned to look at new comments from a small number of sources (possibly down to an individual person). When things get busy they probably even do the computer equivalents of calling in temp workers to handle the extra load.",
"Imagine all those comments coming down a pipe that divides into many smaller pipes. On each pipe there are bots looking at the data in the small pipe to see if it matches what it’s looking for. You can have a bot look at one pipe or copies of the bot looking at many pipes. The pipes are called data streams, and the stream can be partitioned or sharded into smaller streams that you can have filters or small programs that look at the data and do things with it. The partition might be by group name, for example, but it can be partitioned into as many smaller groups as you need. To make things faster, make more partitions so you can have more bots looking at the data."
],
"score": [
11,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxpa69
|
How does software turn off hardware?
|
It makes sense that electrical connections/circuits can be interrupted by flipping a switch (e.g. a light via a light switch in a house). Devices (computers, phones, TVs, etc.) can be turned on/off with a remote or tap of a screen, and this is where I have a hard time understanding how. Are there actually mechanical/moving parts in these devices? If not, how does the software say "I don't want electricity right now?" My phone also can also prevent itself from being charged when I connect it so it doesn't get overcharged. Is that software's doing? Or more tiny mechanical parts?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft3tq1b",
"ft3wf92"
],
"text": [
"You have to understand that there are electronic devices which can control the flow of electricity, but in a non-mechanical fashion. Yes, the power button on your phone is ultimately a mechanical switch, however it only serves as an input to the circuit which actually powers up your phone. Look up basic transistor theory if you want to go down the rabbit hole - it was the invention of the transistor that made/makes all of this possible.",
"What you use for high power stuff is a [relay]( URL_0 ). It is an electrical control switch where the control signal is isolated from the Older mechanical relay works like a switch that you flip od press down but instead of a human finger moving them you have an electromagnet that can pull or push ferromagnetic material like iron. You hear a mechanical click when the turn on and off. It is not uncommon that they are only closed then the magnet is on and does not stay closed when the control power disappears. It is like a button you have to press down. The advantage is f the control fails the electrical object is off. Today we have solid-state relay where you use optical isolation with a LED and a phototransistor for the input and a Transistor, thyristor, TRIAC, etc to switch the power. There is no moving part. & #x200B; For stuff that do not operate at mains power like phones you sight with the electrical signal directly and not optical isolation is needed. For a desktop computer, there is in principle a solid-state relay in the power supply that turns of and off the power to the computer. The electronics that is used to detect that you push down the power button will always be on in the device. So a chip in a phone is always connected to the battery even if the device is off, it detects that you press the button and send a signal to turn on the power to the rest of the phone. Computer, tv, and all other devices where you do not flip a switch or press one that locks down the power button just send a signal to turn on the device. There is a part that always have some power from the power supply even when they are \"off\". It detects the pressing on the button and on TVs operate the IR receiver so you can turn it on with the remote. So most complex electronics have some part that is always on."
],
"score": [
11,
5
],
"text_urls": [
[],
[
"https://en.wikipedia.org/wiki/Relay"
]
]
}
|
[
"url"
] |
[
"url"
] |
gxq4l2
|
How does the Turing test work, and why is it still debatable whether it has been passed or not?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft47625",
"ft45os2",
"ft4l46p"
],
"text": [
"In theory, the Turing Test is a test of a natural language AI's ability to pass as human. You stick a human in front of a computer terminal where they have a text conversation with a series of unknown entities, which could be another human or an AI. The test passes or fails based on whether the human, when interacting with the AI, can only guess that they are AI 50% of the time, which would indicate they cant tell the difference and the guess is down to chance. The Turing test isnt a proper scientific test, AI researchers dont consider it an actual way to measure progress when it comes to language AI for a couple reasons but heres the main one. If the human knows what they are doing, the seemingly limited medium of text communication actually lets you test a lot of things. The big breakthrough for AI will be whats called General Intelligence, this means its capable of operating intelligently across all domains. Current AI is only singularly intelligent, If you stick a chess AI in a driverless car, it will utterly fail to respond intelligently in that situation because its not made to do that. Neither are humans, playing chess and driving cars is very unnatural and not what evolution built us to do, yet we can and we can do both because we posses general intelligence. A natural language AI that might fool someone will be pretty good in the domain of talking like a person... but what happens when you throw it a question like how to bake a cake? [You might get an answer that at a glance looks right but actually read it and it is very wrong]( URL_0 ). It has no understanding of how to cook, just an understanding of what recipes look like. You can do that for whatever you want and if this thing isn't generally intelligent you'l get similar results that'l give the game away. So in practice the Turing Test is actually a ridiculously high bar and often for AI to win in it requires limiting the time people can interact with it and what they can talk about.",
"The Turing test is a thought experiment, not an actual test. Turing proposed that a computer that could communicate with humans and be accepted unseen as a human would be a breakthrough. No, this test has not been passed. Nobody who;s spoken to Alexa or any other advanced speech device believes it's actually a human answering them. Too many non-typical mistakes are made.",
"The Turing test is more of a philosophical claim than a practical test. It's Turing's answer to the question of what it is to be 'intelligent'. Turing argued that if a computer could pretend to be an intelligent human so convincingly that you couldn't tell that it wasn't human, then you had to accept it as 'intelligent'. This is important, because Turing was saying that there isn't some separate magical ingredient called 'intelligence' that some things (people) have and that other things (computers) don't have and can never have. If you behave 'intelligently' in every possible situation, then you are 'intelligent'. Another implication is that it doesn't matter how you get your 'intelligence'. Humans have organic brains; an intelligent computer might be made out of electronic circuits, or Tinker Toys, or hamsters climbing on tiny ladders (my examples, not Turing's). Provided it passed the test, it wouldn't matter what it was made of. Not everyone agreed: a philosopher named John Searle invented a thought experiment called the Chinese Room, in which a man is locked in a room with a big stack of cards. People outside pass in questions written in Chinese. The man -- who doesn't speak Chinese -- looks through his stack of cards until he finds one that has the right Chinese characters on it, then copies the corresponding answer off the back of the card, writes it down and passes it back through the slot. Searle's argument was that we wouldn't say that the man understood Chinese, so we shouldn't say that a computer was 'intelligent' just because it could pass the Turing test. Turing would probably have said that while the *man* might not understand Chinese, the *system* \\-- the man plus the cards -- 'understood' Chinese, to all practical purposes. The neurons in our brains -- parts of the system -- don't understand Chinese or know how to fix a fanbelt or boil an egg ... but we do. Interestingly, the Turing Test was based on a party game called the Imitation Game, in which a woman would pretend to be a man (or vice-versa). Turing would probably not have argued that a woman who successfully pretended to be a man was 'really' a man. But maybe he would have: as a gay man, he may have viewed gender differently to many of his contemporaries, and might have anticipated some of our current debates about gender."
],
"score": [
12,
4,
3
],
"text_urls": [
[
"https://www.peterkrantz.com/2019/recipes-with-gpt2/"
],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
|
gxr61t
|
When banks process an online transfer for 3-5 business days, what is actually happening to the money?
|
And why is it such a long period of time, rather than a shorter software-based authentication of say, one hour?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft4jcit",
"ft4k5hp",
"ft4pwab",
"ft4fmwg"
],
"text": [
"These transactions are being sent by ACH. There are a ton of rules around ACH transactions called NACHA rules. ACH is the first type of electronic money movement in the US that wasn’t a wire transfer. As such ACH is about 30 years old with very few upgrades. Now to the meat of your question. ACH transactions are typically sent in a bulk file. When you schedule your transfer it is saved in this bulk file and at the end of the day it is proceeded and released to the Fed with a value date. The value date is typically two days in the future. The receiving bank will usually get it the next day, but will not release it to the account until the value date. ACH has been upgraded recently and next day and same day transactions are possible, but same day has not been widely adopted. Same day ACH also has limits on the dollar amount and cost a little more to process",
"Think it used to take that long. Now it doesn’t but holding on to your money for extra days is making them money so they kept doing it.",
"The banks may also invest it for a night and make quick money. There’s a word for it. I think it’s called something like a repurchase agreement. I worked for a investment company that did this with their cash-in-bank money.",
"It dates back to when it was all done by paper and it took that long to process millions of pieces of paper, however now it can be done electronically it should only take seconds, but while it is being processed the banks make money on your money transfer so there is no incentive to do it quickly."
],
"score": [
34,
9,
5,
3
],
"text_urls": [
[],
[],
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
gxw3no
|
How do people make cheats for games, like wall-hack and aimbot?
|
Wall-hack is more interesting because how do people create the cheat to know exactly where every player is? How aimbot is created too? And why do games can't prevent people from being able to make those cheats?
|
Technology
|
explainlikeimfive
|
{
"a_id": [
"ft5rd03",
"ft5topv"
],
"text": [
"A game is made of code and code references other code. So to know where a player is there has to be data stating their x/y/z position at all times. Using memory readers you can have a program “see” where a player is and access your mouse to aim at that player. In the same context whether a wall is solid or not is just code and bu changing the wall’s data to say it’s not solid or to say you as a player are not solid you can pass right through walls. These are the same techniques used by systems such as the Gameshark and Action Replay that let you change live count, have infinite ammo, etc.",
"As long as the game is running on local hardware, cheaters will have access to the memory locations and data that store game-state information. If they have access, they can modify it. Turning off wall textures and setting the underlying polygons to transparent allows wall-hacking. Game cheat detection is sort of like old computer virus scanning programs. They know the exact program names and code of popular cheat software, but are blind to even slightly modified cheat programs. The future of anti-cheat is likely going to be big-data analysis of player activity. Have a player who, 100% of the time, reacts \"correctly\" to an opponent on the other side of a wall? Query that game client for certain memory values to detect modification. Have a player with an accuracy rating beyond 3 standard deviations of normal? Check for aimbot activity. That sort of thing."
],
"score": [
8,
4
],
"text_urls": [
[],
[]
]
}
|
[
"url"
] |
[
"url"
] |
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